diff options
Diffstat (limited to 'pkg/tcpip')
32 files changed, 8260 insertions, 224 deletions
diff --git a/pkg/tcpip/network/fragmentation/fragmentation.go b/pkg/tcpip/network/fragmentation/fragmentation.go index 2982450f8..1827666c5 100644 --- a/pkg/tcpip/network/fragmentation/fragmentation.go +++ b/pkg/tcpip/network/fragmentation/fragmentation.go @@ -17,28 +17,58 @@ package fragmentation import ( + "errors" "fmt" "log" "time" "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" ) -// DefaultReassembleTimeout is based on the linux stack: net.ipv4.ipfrag_time. -const DefaultReassembleTimeout = 30 * time.Second +const ( + // DefaultReassembleTimeout is based on the linux stack: net.ipv4.ipfrag_time. + DefaultReassembleTimeout = 30 * time.Second -// HighFragThreshold is the threshold at which we start trimming old -// fragmented packets. Linux uses a default value of 4 MB. See -// net.ipv4.ipfrag_high_thresh for more information. -const HighFragThreshold = 4 << 20 // 4MB + // HighFragThreshold is the threshold at which we start trimming old + // fragmented packets. Linux uses a default value of 4 MB. See + // net.ipv4.ipfrag_high_thresh for more information. + HighFragThreshold = 4 << 20 // 4MB -// LowFragThreshold is the threshold we reach to when we start dropping -// older fragmented packets. It's important that we keep enough room for newer -// packets to be re-assembled. Hence, this needs to be lower than -// HighFragThreshold enough. Linux uses a default value of 3 MB. See -// net.ipv4.ipfrag_low_thresh for more information. -const LowFragThreshold = 3 << 20 // 3MB + // LowFragThreshold is the threshold we reach to when we start dropping + // older fragmented packets. It's important that we keep enough room for newer + // packets to be re-assembled. Hence, this needs to be lower than + // HighFragThreshold enough. Linux uses a default value of 3 MB. See + // net.ipv4.ipfrag_low_thresh for more information. + LowFragThreshold = 3 << 20 // 3MB + + // minBlockSize is the minimum block size for fragments. + minBlockSize = 1 +) + +var ( + // ErrInvalidArgs indicates to the caller that that an invalid argument was + // provided. + ErrInvalidArgs = errors.New("invalid args") +) + +// FragmentID is the identifier for a fragment. +type FragmentID struct { + // Source is the source address of the fragment. + Source tcpip.Address + + // Destination is the destination address of the fragment. + Destination tcpip.Address + + // ID is the identification value of the fragment. + // + // This is a uint32 because IPv6 uses a 32-bit identification value. + ID uint32 + + // The protocol for the packet. + Protocol uint8 +} // Fragmentation is the main structure that other modules // of the stack should use to implement IP Fragmentation. @@ -46,14 +76,17 @@ type Fragmentation struct { mu sync.Mutex highLimit int lowLimit int - reassemblers map[uint32]*reassembler + reassemblers map[FragmentID]*reassembler rList reassemblerList size int timeout time.Duration + blockSize uint16 } // NewFragmentation creates a new Fragmentation. // +// blockSize specifies the fragment block size, in bytes. +// // highMemoryLimit specifies the limit on the memory consumed // by the fragments stored by Fragmentation (overhead of internal data-structures // is not accounted). Fragments are dropped when the limit is reached. @@ -64,7 +97,7 @@ type Fragmentation struct { // reassemblingTimeout specifies the maximum time allowed to reassemble a packet. // Fragments are lazily evicted only when a new a packet with an // already existing fragmentation-id arrives after the timeout. -func NewFragmentation(highMemoryLimit, lowMemoryLimit int, reassemblingTimeout time.Duration) *Fragmentation { +func NewFragmentation(blockSize uint16, highMemoryLimit, lowMemoryLimit int, reassemblingTimeout time.Duration) *Fragmentation { if lowMemoryLimit >= highMemoryLimit { lowMemoryLimit = highMemoryLimit } @@ -73,17 +106,46 @@ func NewFragmentation(highMemoryLimit, lowMemoryLimit int, reassemblingTimeout t lowMemoryLimit = 0 } + if blockSize < minBlockSize { + blockSize = minBlockSize + } + return &Fragmentation{ - reassemblers: make(map[uint32]*reassembler), + reassemblers: make(map[FragmentID]*reassembler), highLimit: highMemoryLimit, lowLimit: lowMemoryLimit, timeout: reassemblingTimeout, + blockSize: blockSize, } } // Process processes an incoming fragment belonging to an ID and returns a // complete packet when all the packets belonging to that ID have been received. -func (f *Fragmentation) Process(id uint32, first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, error) { +// +// [first, last] is the range of the fragment bytes. +// +// first must be a multiple of the block size f is configured with. The size +// of the fragment data must be a multiple of the block size, unless there are +// no fragments following this fragment (more set to false). +func (f *Fragmentation) Process(id FragmentID, first, last uint16, more bool, vv buffer.VectorisedView) (buffer.VectorisedView, bool, error) { + if first > last { + return buffer.VectorisedView{}, false, fmt.Errorf("first=%d is greater than last=%d: %w", first, last, ErrInvalidArgs) + } + + if first%f.blockSize != 0 { + return buffer.VectorisedView{}, false, fmt.Errorf("first=%d is not a multiple of block size=%d: %w", first, f.blockSize, ErrInvalidArgs) + } + + fragmentSize := last - first + 1 + if more && fragmentSize%f.blockSize != 0 { + return buffer.VectorisedView{}, false, fmt.Errorf("fragment size=%d bytes is not a multiple of block size=%d on non-final fragment: %w", fragmentSize, f.blockSize, ErrInvalidArgs) + } + + if l := vv.Size(); l < int(fragmentSize) { + return buffer.VectorisedView{}, false, fmt.Errorf("got fragment size=%d bytes less than the expected fragment size=%d bytes (first=%d last=%d): %w", l, fragmentSize, first, last, ErrInvalidArgs) + } + vv.CapLength(int(fragmentSize)) + f.mu.Lock() r, ok := f.reassemblers[id] if ok && r.tooOld(f.timeout) { diff --git a/pkg/tcpip/network/fragmentation/fragmentation_test.go b/pkg/tcpip/network/fragmentation/fragmentation_test.go index 72c0f53be..9eedd33c4 100644 --- a/pkg/tcpip/network/fragmentation/fragmentation_test.go +++ b/pkg/tcpip/network/fragmentation/fragmentation_test.go @@ -15,6 +15,7 @@ package fragmentation import ( + "errors" "reflect" "testing" "time" @@ -33,7 +34,7 @@ func vv(size int, pieces ...string) buffer.VectorisedView { } type processInput struct { - id uint32 + id FragmentID first uint16 last uint16 more bool @@ -53,8 +54,8 @@ var processTestCases = []struct { { comment: "One ID", in: []processInput{ - {id: 0, first: 0, last: 1, more: true, vv: vv(2, "01")}, - {id: 0, first: 2, last: 3, more: false, vv: vv(2, "23")}, + {id: FragmentID{ID: 0}, first: 0, last: 1, more: true, vv: vv(2, "01")}, + {id: FragmentID{ID: 0}, first: 2, last: 3, more: false, vv: vv(2, "23")}, }, out: []processOutput{ {vv: buffer.VectorisedView{}, done: false}, @@ -64,10 +65,10 @@ var processTestCases = []struct { { comment: "Two IDs", in: []processInput{ - {id: 0, first: 0, last: 1, more: true, vv: vv(2, "01")}, - {id: 1, first: 0, last: 1, more: true, vv: vv(2, "ab")}, - {id: 1, first: 2, last: 3, more: false, vv: vv(2, "cd")}, - {id: 0, first: 2, last: 3, more: false, vv: vv(2, "23")}, + {id: FragmentID{ID: 0}, first: 0, last: 1, more: true, vv: vv(2, "01")}, + {id: FragmentID{ID: 1}, first: 0, last: 1, more: true, vv: vv(2, "ab")}, + {id: FragmentID{ID: 1}, first: 2, last: 3, more: false, vv: vv(2, "cd")}, + {id: FragmentID{ID: 0}, first: 2, last: 3, more: false, vv: vv(2, "23")}, }, out: []processOutput{ {vv: buffer.VectorisedView{}, done: false}, @@ -81,7 +82,7 @@ var processTestCases = []struct { func TestFragmentationProcess(t *testing.T) { for _, c := range processTestCases { t.Run(c.comment, func(t *testing.T) { - f := NewFragmentation(1024, 512, DefaultReassembleTimeout) + f := NewFragmentation(minBlockSize, 1024, 512, DefaultReassembleTimeout) for i, in := range c.in { vv, done, err := f.Process(in.id, in.first, in.last, in.more, in.vv) if err != nil { @@ -110,14 +111,14 @@ func TestFragmentationProcess(t *testing.T) { func TestReassemblingTimeout(t *testing.T) { timeout := time.Millisecond - f := NewFragmentation(1024, 512, timeout) + f := NewFragmentation(minBlockSize, 1024, 512, timeout) // Send first fragment with id = 0, first = 0, last = 0, and more = true. - f.Process(0, 0, 0, true, vv(1, "0")) + f.Process(FragmentID{}, 0, 0, true, vv(1, "0")) // Sleep more than the timeout. time.Sleep(2 * timeout) // Send another fragment that completes a packet. // However, no packet should be reassembled because the fragment arrived after the timeout. - _, done, err := f.Process(0, 1, 1, false, vv(1, "1")) + _, done, err := f.Process(FragmentID{}, 1, 1, false, vv(1, "1")) if err != nil { t.Fatalf("f.Process(0, 1, 1, false, vv(1, \"1\")) failed: %v", err) } @@ -127,35 +128,35 @@ func TestReassemblingTimeout(t *testing.T) { } func TestMemoryLimits(t *testing.T) { - f := NewFragmentation(3, 1, DefaultReassembleTimeout) + f := NewFragmentation(minBlockSize, 3, 1, DefaultReassembleTimeout) // Send first fragment with id = 0. - f.Process(0, 0, 0, true, vv(1, "0")) + f.Process(FragmentID{ID: 0}, 0, 0, true, vv(1, "0")) // Send first fragment with id = 1. - f.Process(1, 0, 0, true, vv(1, "1")) + f.Process(FragmentID{ID: 1}, 0, 0, true, vv(1, "1")) // Send first fragment with id = 2. - f.Process(2, 0, 0, true, vv(1, "2")) + f.Process(FragmentID{ID: 2}, 0, 0, true, vv(1, "2")) // Send first fragment with id = 3. This should caused id = 0 and id = 1 to be // evicted. - f.Process(3, 0, 0, true, vv(1, "3")) + f.Process(FragmentID{ID: 3}, 0, 0, true, vv(1, "3")) - if _, ok := f.reassemblers[0]; ok { + if _, ok := f.reassemblers[FragmentID{ID: 0}]; ok { t.Errorf("Memory limits are not respected: id=0 has not been evicted.") } - if _, ok := f.reassemblers[1]; ok { + if _, ok := f.reassemblers[FragmentID{ID: 1}]; ok { t.Errorf("Memory limits are not respected: id=1 has not been evicted.") } - if _, ok := f.reassemblers[3]; !ok { + if _, ok := f.reassemblers[FragmentID{ID: 3}]; !ok { t.Errorf("Implementation of memory limits is wrong: id=3 is not present.") } } func TestMemoryLimitsIgnoresDuplicates(t *testing.T) { - f := NewFragmentation(1, 0, DefaultReassembleTimeout) + f := NewFragmentation(minBlockSize, 1, 0, DefaultReassembleTimeout) // Send first fragment with id = 0. - f.Process(0, 0, 0, true, vv(1, "0")) + f.Process(FragmentID{}, 0, 0, true, vv(1, "0")) // Send the same packet again. - f.Process(0, 0, 0, true, vv(1, "0")) + f.Process(FragmentID{}, 0, 0, true, vv(1, "0")) got := f.size want := 1 @@ -163,3 +164,97 @@ func TestMemoryLimitsIgnoresDuplicates(t *testing.T) { t.Errorf("Wrong size, duplicates are not handled correctly: got=%d, want=%d.", got, want) } } + +func TestErrors(t *testing.T) { + tests := []struct { + name string + blockSize uint16 + first uint16 + last uint16 + more bool + data string + err error + }{ + { + name: "exact block size without more", + blockSize: 2, + first: 2, + last: 3, + more: false, + data: "01", + }, + { + name: "exact block size with more", + blockSize: 2, + first: 2, + last: 3, + more: true, + data: "01", + }, + { + name: "exact block size with more and extra data", + blockSize: 2, + first: 2, + last: 3, + more: true, + data: "012", + }, + { + name: "exact block size with more and too little data", + blockSize: 2, + first: 2, + last: 3, + more: true, + data: "0", + err: ErrInvalidArgs, + }, + { + name: "not exact block size with more", + blockSize: 2, + first: 2, + last: 2, + more: true, + data: "0", + err: ErrInvalidArgs, + }, + { + name: "not exact block size without more", + blockSize: 2, + first: 2, + last: 2, + more: false, + data: "0", + }, + { + name: "first not a multiple of block size", + blockSize: 2, + first: 3, + last: 4, + more: true, + data: "01", + err: ErrInvalidArgs, + }, + { + name: "first more than last", + blockSize: 2, + first: 4, + last: 3, + more: true, + data: "01", + err: ErrInvalidArgs, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + f := NewFragmentation(test.blockSize, HighFragThreshold, LowFragThreshold, DefaultReassembleTimeout) + _, done, err := f.Process(FragmentID{}, test.first, test.last, test.more, vv(len(test.data), test.data)) + if !errors.Is(err, test.err) { + t.Errorf("got Proceess(_, %d, %d, %t, %q) = (_, _, %v), want = (_, _, %v)", test.first, test.last, test.more, test.data, err, test.err) + } + if done { + t.Errorf("got Proceess(_, %d, %d, %t, %q) = (_, true, _), want = (_, false, _)", test.first, test.last, test.more, test.data) + } + }) + } +} diff --git a/pkg/tcpip/network/fragmentation/reassembler.go b/pkg/tcpip/network/fragmentation/reassembler.go index 0a83d81f2..50d30bbf0 100644 --- a/pkg/tcpip/network/fragmentation/reassembler.go +++ b/pkg/tcpip/network/fragmentation/reassembler.go @@ -32,7 +32,7 @@ type hole struct { type reassembler struct { reassemblerEntry - id uint32 + id FragmentID size int mu sync.Mutex holes []hole @@ -42,7 +42,7 @@ type reassembler struct { creationTime time.Time } -func newReassembler(id uint32) *reassembler { +func newReassembler(id FragmentID) *reassembler { r := &reassembler{ id: id, holes: make([]hole, 0, 16), diff --git a/pkg/tcpip/network/fragmentation/reassembler_test.go b/pkg/tcpip/network/fragmentation/reassembler_test.go index 7eee0710d..dff7c9dcb 100644 --- a/pkg/tcpip/network/fragmentation/reassembler_test.go +++ b/pkg/tcpip/network/fragmentation/reassembler_test.go @@ -94,7 +94,7 @@ var holesTestCases = []struct { func TestUpdateHoles(t *testing.T) { for _, c := range holesTestCases { - r := newReassembler(0) + r := newReassembler(FragmentID{}) for _, i := range c.in { r.updateHoles(i.first, i.last, i.more) } diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index b1776e5ee..d5f5d38f7 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -45,6 +45,10 @@ const ( // buckets is the number of identifier buckets. buckets = 2048 + + // The size of a fragment block, in bytes, as per RFC 791 section 3.1, + // page 14. + fragmentblockSize = 8 ) type endpoint struct { @@ -66,7 +70,7 @@ func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWi prefixLen: addrWithPrefix.PrefixLen, linkEP: linkEP, dispatcher: dispatcher, - fragmentation: fragmentation.NewFragmentation(fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), + fragmentation: fragmentation.NewFragmentation(fragmentblockSize, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), protocol: p, stack: st, } @@ -438,7 +442,18 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { } var ready bool var err error - pkt.Data, ready, err = e.fragmentation.Process(hash.IPv4FragmentHash(h), h.FragmentOffset(), last, h.More(), pkt.Data) + pkt.Data, ready, err = e.fragmentation.Process( + fragmentation.FragmentID{ + Source: h.SourceAddress(), + Destination: h.DestinationAddress(), + ID: uint32(h.ID()), + Protocol: h.Protocol(), + }, + h.FragmentOffset(), + last, + h.More(), + pkt.Data, + ) if err != nil { r.Stats().IP.MalformedPacketsReceived.Increment() r.Stats().IP.MalformedFragmentsReceived.Increment() diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go index 11e579c4b..ded97ac64 100644 --- a/pkg/tcpip/network/ipv4/ipv4_test.go +++ b/pkg/tcpip/network/ipv4/ipv4_test.go @@ -486,12 +486,16 @@ func TestInvalidFragments(t *testing.T) { // TestReceiveFragments feeds fragments in through the incoming packet path to // test reassembly func TestReceiveFragments(t *testing.T) { - const addr1 = "\x0c\xa8\x00\x01" // 192.168.0.1 - const addr2 = "\x0c\xa8\x00\x02" // 192.168.0.2 - const nicID = 1 + const ( + nicID = 1 + + addr1 = "\x0c\xa8\x00\x01" // 192.168.0.1 + addr2 = "\x0c\xa8\x00\x02" // 192.168.0.2 + addr3 = "\x0c\xa8\x00\x03" // 192.168.0.3 + ) // Build and return a UDP header containing payload. - udpGen := func(payloadLen int, multiplier uint8) buffer.View { + udpGen := func(payloadLen int, multiplier uint8, src, dst tcpip.Address) buffer.View { payload := buffer.NewView(payloadLen) for i := 0; i < len(payload); i++ { payload[i] = uint8(i) * multiplier @@ -507,20 +511,29 @@ func TestReceiveFragments(t *testing.T) { Length: uint16(udpLength), }) copy(u.Payload(), payload) - sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, addr1, addr2, uint16(udpLength)) + sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, src, dst, uint16(udpLength)) sum = header.Checksum(payload, sum) u.SetChecksum(^u.CalculateChecksum(sum)) return hdr.View() } // UDP header plus a payload of 0..256 - ipv4Payload1 := udpGen(256, 1) - udpPayload1 := ipv4Payload1[header.UDPMinimumSize:] + ipv4Payload1Addr1ToAddr2 := udpGen(256, 1, addr1, addr2) + udpPayload1Addr1ToAddr2 := ipv4Payload1Addr1ToAddr2[header.UDPMinimumSize:] + ipv4Payload1Addr3ToAddr2 := udpGen(256, 1, addr3, addr2) + udpPayload1Addr3ToAddr2 := ipv4Payload1Addr3ToAddr2[header.UDPMinimumSize:] // UDP header plus a payload of 0..256 in increments of 2. - ipv4Payload2 := udpGen(128, 2) - udpPayload2 := ipv4Payload2[header.UDPMinimumSize:] + ipv4Payload2Addr1ToAddr2 := udpGen(128, 2, addr1, addr2) + udpPayload2Addr1ToAddr2 := ipv4Payload2Addr1ToAddr2[header.UDPMinimumSize:] + // UDP header plus a payload of 0..256 in increments of 3. + // Used to test cases where the fragment blocks are not a multiple of + // the fragment block size of 8 (RFC 791 section 3.1 page 14). + ipv4Payload3Addr1ToAddr2 := udpGen(127, 3, addr1, addr2) + udpPayload3Addr1ToAddr2 := ipv4Payload3Addr1ToAddr2[header.UDPMinimumSize:] type fragmentData struct { + srcAddr tcpip.Address + dstAddr tcpip.Address id uint16 flags uint8 fragmentOffset uint16 @@ -536,22 +549,40 @@ func TestReceiveFragments(t *testing.T) { name: "No fragmentation", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: 0, + fragmentOffset: 0, + payload: ipv4Payload1Addr1ToAddr2, + }, + }, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, + }, + { + name: "No fragmentation with size not a multiple of fragment block size", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: 0, fragmentOffset: 0, - payload: ipv4Payload1, + payload: ipv4Payload3Addr1ToAddr2, }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload3Addr1ToAddr2}, }, { name: "More fragments without payload", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload1, + payload: ipv4Payload1Addr1ToAddr2, }, }, expectedPayloads: nil, @@ -560,10 +591,12 @@ func TestReceiveFragments(t *testing.T) { name: "Non-zero fragment offset without payload", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: 0, fragmentOffset: 8, - payload: ipv4Payload1, + payload: ipv4Payload1Addr1ToAddr2, }, }, expectedPayloads: nil, @@ -572,34 +605,86 @@ func TestReceiveFragments(t *testing.T) { name: "Two fragments", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: header.IPv4FlagMoreFragments, + fragmentOffset: 0, + payload: ipv4Payload1Addr1ToAddr2[:64], + }, + { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: 0, + fragmentOffset: 64, + payload: ipv4Payload1Addr1ToAddr2[64:], + }, + }, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, + }, + { + name: "Two fragments with last fragment size not a multiple of fragment block size", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload1[:64], + payload: ipv4Payload3Addr1ToAddr2[:64], }, { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: 0, fragmentOffset: 64, - payload: ipv4Payload1[64:], + payload: ipv4Payload3Addr1ToAddr2[64:], }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload3Addr1ToAddr2}, + }, + { + name: "Two fragments with first fragment size not a multiple of fragment block size", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: header.IPv4FlagMoreFragments, + fragmentOffset: 0, + payload: ipv4Payload3Addr1ToAddr2[:63], + }, + { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: 0, + fragmentOffset: 63, + payload: ipv4Payload3Addr1ToAddr2[63:], + }, + }, + expectedPayloads: nil, }, { name: "Second fragment has MoreFlags set", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload1[:64], + payload: ipv4Payload1Addr1ToAddr2[:64], }, { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 64, - payload: ipv4Payload1[64:], + payload: ipv4Payload1Addr1ToAddr2[64:], }, }, expectedPayloads: nil, @@ -608,16 +693,20 @@ func TestReceiveFragments(t *testing.T) { name: "Two fragments with different IDs", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload1[:64], + payload: ipv4Payload1Addr1ToAddr2[:64], }, { + srcAddr: addr1, + dstAddr: addr2, id: 2, flags: 0, fragmentOffset: 64, - payload: ipv4Payload1[64:], + payload: ipv4Payload1Addr1ToAddr2[64:], }, }, expectedPayloads: nil, @@ -626,40 +715,88 @@ func TestReceiveFragments(t *testing.T) { name: "Two interleaved fragmented packets", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload1[:64], + payload: ipv4Payload1Addr1ToAddr2[:64], }, { + srcAddr: addr1, + dstAddr: addr2, id: 2, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload2[:64], + payload: ipv4Payload2Addr1ToAddr2[:64], }, { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: 0, fragmentOffset: 64, - payload: ipv4Payload1[64:], + payload: ipv4Payload1Addr1ToAddr2[64:], }, { + srcAddr: addr1, + dstAddr: addr2, id: 2, flags: 0, fragmentOffset: 64, - payload: ipv4Payload2[64:], + payload: ipv4Payload2Addr1ToAddr2[64:], + }, + }, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2, udpPayload2Addr1ToAddr2}, + }, + { + name: "Two interleaved fragmented packets from different sources but with same ID", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: header.IPv4FlagMoreFragments, + fragmentOffset: 0, + payload: ipv4Payload1Addr1ToAddr2[:64], + }, + { + srcAddr: addr3, + dstAddr: addr2, + id: 1, + flags: header.IPv4FlagMoreFragments, + fragmentOffset: 0, + payload: ipv4Payload1Addr3ToAddr2[:32], + }, + { + srcAddr: addr1, + dstAddr: addr2, + id: 1, + flags: 0, + fragmentOffset: 64, + payload: ipv4Payload1Addr1ToAddr2[64:], + }, + { + srcAddr: addr3, + dstAddr: addr2, + id: 1, + flags: 0, + fragmentOffset: 32, + payload: ipv4Payload1Addr3ToAddr2[32:], }, }, - expectedPayloads: [][]byte{udpPayload1, udpPayload2}, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2, udpPayload1Addr3ToAddr2}, }, { name: "Fragment without followup", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, id: 1, flags: header.IPv4FlagMoreFragments, fragmentOffset: 0, - payload: ipv4Payload1[:64], + payload: ipv4Payload1Addr1ToAddr2[:64], }, }, expectedPayloads: nil, @@ -711,8 +848,8 @@ func TestReceiveFragments(t *testing.T) { FragmentOffset: frag.fragmentOffset, TTL: 64, Protocol: uint8(header.UDPProtocolNumber), - SrcAddr: addr1, - DstAddr: addr2, + SrcAddr: frag.srcAddr, + DstAddr: frag.dstAddr, }) vv := hdr.View().ToVectorisedView() diff --git a/pkg/tcpip/network/ipv6/BUILD b/pkg/tcpip/network/ipv6/BUILD index feada63dc..bcc64994e 100644 --- a/pkg/tcpip/network/ipv6/BUILD +++ b/pkg/tcpip/network/ipv6/BUILD @@ -14,7 +14,6 @@ go_library( "//pkg/tcpip/buffer", "//pkg/tcpip/header", "//pkg/tcpip/network/fragmentation", - "//pkg/tcpip/network/hash", "//pkg/tcpip/stack", ], ) diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index 95fbcf2d1..a0a5c9c01 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -28,7 +28,6 @@ import ( "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/header" "gvisor.dev/gvisor/pkg/tcpip/network/fragmentation" - "gvisor.dev/gvisor/pkg/tcpip/network/hash" "gvisor.dev/gvisor/pkg/tcpip/stack" ) @@ -343,7 +342,19 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { var ready bool // Note that pkt doesn't have its transport header set after reassembly, // and won't until DeliverNetworkPacket sets it. - pkt.Data, ready, err = e.fragmentation.Process(hash.IPv6FragmentHash(h, extHdr.ID()), start, last, extHdr.More(), rawPayload.Buf) + pkt.Data, ready, err = e.fragmentation.Process( + // IPv6 ignores the Protocol field since the ID only needs to be unique + // across source-destination pairs, as per RFC 8200 section 4.5. + fragmentation.FragmentID{ + Source: h.SourceAddress(), + Destination: h.DestinationAddress(), + ID: extHdr.ID(), + }, + start, + last, + extHdr.More(), + rawPayload.Buf, + ) if err != nil { r.Stats().IP.MalformedPacketsReceived.Increment() r.Stats().IP.MalformedFragmentsReceived.Increment() @@ -467,7 +478,7 @@ func (p *protocol) NewEndpoint(nicID tcpip.NICID, addrWithPrefix tcpip.AddressWi linkEP: linkEP, linkAddrCache: linkAddrCache, dispatcher: dispatcher, - fragmentation: fragmentation.NewFragmentation(fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), + fragmentation: fragmentation.NewFragmentation(header.IPv6FragmentExtHdrFragmentOffsetBytesPerUnit, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, fragmentation.DefaultReassembleTimeout), protocol: p, }, nil } diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go index 213ff64f2..3d65814de 100644 --- a/pkg/tcpip/network/ipv6/ipv6_test.go +++ b/pkg/tcpip/network/ipv6/ipv6_test.go @@ -673,20 +673,27 @@ func TestReceiveIPv6ExtHdrs(t *testing.T) { // fragmentData holds the IPv6 payload for a fragmented IPv6 packet. type fragmentData struct { + srcAddr tcpip.Address + dstAddr tcpip.Address nextHdr uint8 data buffer.VectorisedView } func TestReceiveIPv6Fragments(t *testing.T) { - const nicID = 1 - const udpPayload1Length = 256 - const udpPayload2Length = 128 - const fragmentExtHdrLen = 8 - // Note, not all routing extension headers will be 8 bytes but this test - // uses 8 byte routing extension headers for most sub tests. - const routingExtHdrLen = 8 - - udpGen := func(payload []byte, multiplier uint8) buffer.View { + const ( + nicID = 1 + udpPayload1Length = 256 + udpPayload2Length = 128 + // Used to test cases where the fragment blocks are not a multiple of + // the fragment block size of 8 (RFC 8200 section 4.5). + udpPayload3Length = 127 + fragmentExtHdrLen = 8 + // Note, not all routing extension headers will be 8 bytes but this test + // uses 8 byte routing extension headers for most sub tests. + routingExtHdrLen = 8 + ) + + udpGen := func(payload []byte, multiplier uint8, src, dst tcpip.Address) buffer.View { payloadLen := len(payload) for i := 0; i < payloadLen; i++ { payload[i] = uint8(i) * multiplier @@ -702,19 +709,27 @@ func TestReceiveIPv6Fragments(t *testing.T) { Length: uint16(udpLength), }) copy(u.Payload(), payload) - sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, addr1, addr2, uint16(udpLength)) + sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, src, dst, uint16(udpLength)) sum = header.Checksum(payload, sum) u.SetChecksum(^u.CalculateChecksum(sum)) return hdr.View() } - var udpPayload1Buf [udpPayload1Length]byte - udpPayload1 := udpPayload1Buf[:] - ipv6Payload1 := udpGen(udpPayload1, 1) + var udpPayload1Addr1ToAddr2Buf [udpPayload1Length]byte + udpPayload1Addr1ToAddr2 := udpPayload1Addr1ToAddr2Buf[:] + ipv6Payload1Addr1ToAddr2 := udpGen(udpPayload1Addr1ToAddr2, 1, addr1, addr2) + + var udpPayload1Addr3ToAddr2Buf [udpPayload1Length]byte + udpPayload1Addr3ToAddr2 := udpPayload1Addr3ToAddr2Buf[:] + ipv6Payload1Addr3ToAddr2 := udpGen(udpPayload1Addr3ToAddr2, 4, addr3, addr2) - var udpPayload2Buf [udpPayload2Length]byte - udpPayload2 := udpPayload2Buf[:] - ipv6Payload2 := udpGen(udpPayload2, 2) + var udpPayload2Addr1ToAddr2Buf [udpPayload2Length]byte + udpPayload2Addr1ToAddr2 := udpPayload2Addr1ToAddr2Buf[:] + ipv6Payload2Addr1ToAddr2 := udpGen(udpPayload2Addr1ToAddr2, 2, addr1, addr2) + + var udpPayload3Addr1ToAddr2Buf [udpPayload3Length]byte + udpPayload3Addr1ToAddr2 := udpPayload3Addr1ToAddr2Buf[:] + ipv6Payload3Addr1ToAddr2 := udpGen(udpPayload3Addr1ToAddr2, 3, addr1, addr2) tests := []struct { name string @@ -726,34 +741,98 @@ func TestReceiveIPv6Fragments(t *testing.T) { name: "No fragmentation", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: uint8(header.UDPProtocolNumber), - data: ipv6Payload1.ToVectorisedView(), + data: ipv6Payload1Addr1ToAddr2.ToVectorisedView(), }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, }, { name: "Atomic fragment", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2), + []buffer.View{ + // Fragment extension header. + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 0, 0, 0, 0, 0}), + + ipv6Payload1Addr1ToAddr2, + }, + ), + }, + }, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, + }, + { + name: "Atomic fragment with size not a multiple of fragment block size", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1), + fragmentExtHdrLen+len(ipv6Payload3Addr1ToAddr2), []buffer.View{ // Fragment extension header. buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 0, 0, 0, 0, 0}), - ipv6Payload1, + ipv6Payload3Addr1ToAddr2, }, ), }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload3Addr1ToAddr2}, }, { name: "Two fragments", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+64, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 0, More = true, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), + + ipv6Payload1Addr1ToAddr2[:64], + }, + ), + }, + { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 8, More = false, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), + + ipv6Payload1Addr1ToAddr2[64:], + }, + ), + }, + }, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, + }, + { + name: "Two fragments with last fragment size not a multiple of fragment block size", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( fragmentExtHdrLen+64, @@ -763,31 +842,73 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), - ipv6Payload1[:64], + ipv6Payload3Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1)-64, + fragmentExtHdrLen+len(ipv6Payload3Addr1ToAddr2)-64, []buffer.View{ // Fragment extension header. // // Fragment offset = 8, More = false, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload3Addr1ToAddr2[64:], }, ), }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload3Addr1ToAddr2}, + }, + { + name: "Two fragments with first fragment size not a multiple of fragment block size", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+63, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 0, More = true, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), + + ipv6Payload3Addr1ToAddr2[:63], + }, + ), + }, + { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+len(ipv6Payload3Addr1ToAddr2)-63, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 8, More = false, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), + + ipv6Payload3Addr1ToAddr2[63:], + }, + ), + }, + }, + expectedPayloads: nil, }, { name: "Two fragments with different IDs", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( fragmentExtHdrLen+64, @@ -797,21 +918,23 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1)-64, + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Fragment extension header. // // Fragment offset = 8, More = false, ID = 2 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 2}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, @@ -822,6 +945,8 @@ func TestReceiveIPv6Fragments(t *testing.T) { name: "Two fragments with per-fragment routing header with zero segments left", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: routingExtHdrID, data: buffer.NewVectorisedView( routingExtHdrLen+fragmentExtHdrLen+64, @@ -836,14 +961,16 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: routingExtHdrID, data: buffer.NewVectorisedView( - routingExtHdrLen+fragmentExtHdrLen+len(ipv6Payload1)-64, + routingExtHdrLen+fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Routing extension header. // @@ -855,17 +982,19 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 8, More = false, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, }, { name: "Two fragments with per-fragment routing header with non-zero segments left", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: routingExtHdrID, data: buffer.NewVectorisedView( routingExtHdrLen+fragmentExtHdrLen+64, @@ -880,14 +1009,16 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: routingExtHdrID, data: buffer.NewVectorisedView( - routingExtHdrLen+fragmentExtHdrLen+len(ipv6Payload1)-64, + routingExtHdrLen+fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Routing extension header. // @@ -899,7 +1030,7 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 9, More = false, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 72, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, @@ -910,6 +1041,8 @@ func TestReceiveIPv6Fragments(t *testing.T) { name: "Two fragments with routing header with zero segments left", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( routingExtHdrLen+fragmentExtHdrLen+64, @@ -924,31 +1057,35 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Segments left = 0. buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 1, 0, 2, 3, 4, 5}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1)-64, + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Fragment extension header. // // Fragment offset = 9, More = false, ID = 1 buffer.View([]byte{routingExtHdrID, 0, 0, 72, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, }, - expectedPayloads: [][]byte{udpPayload1}, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2}, }, { name: "Two fragments with routing header with non-zero segments left", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( routingExtHdrLen+fragmentExtHdrLen+64, @@ -963,21 +1100,23 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Segments left = 1. buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 1, 1, 2, 3, 4, 5}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1)-64, + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Fragment extension header. // // Fragment offset = 9, More = false, ID = 1 buffer.View([]byte{routingExtHdrID, 0, 0, 72, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, @@ -988,6 +1127,8 @@ func TestReceiveIPv6Fragments(t *testing.T) { name: "Two fragments with routing header with zero segments left across fragments", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( // The length of this payload is fragmentExtHdrLen+8 because the @@ -1008,12 +1149,14 @@ func TestReceiveIPv6Fragments(t *testing.T) { ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( // The length of this payload is - // fragmentExtHdrLen+8+len(ipv6Payload1) because the last 8 bytes of + // fragmentExtHdrLen+8+len(ipv6Payload1Addr1ToAddr2) because the last 8 bytes of // the 16 byte routing extension header is in this fagment. - fragmentExtHdrLen+8+len(ipv6Payload1), + fragmentExtHdrLen+8+len(ipv6Payload1Addr1ToAddr2), []buffer.View{ // Fragment extension header. // @@ -1023,7 +1166,7 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Routing extension header (part 2) buffer.View([]byte{6, 7, 8, 9, 10, 11, 12, 13}), - ipv6Payload1, + ipv6Payload1Addr1ToAddr2, }, ), }, @@ -1034,6 +1177,8 @@ func TestReceiveIPv6Fragments(t *testing.T) { name: "Two fragments with routing header with non-zero segments left across fragments", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( // The length of this payload is fragmentExtHdrLen+8 because the @@ -1054,12 +1199,14 @@ func TestReceiveIPv6Fragments(t *testing.T) { ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( // The length of this payload is - // fragmentExtHdrLen+8+len(ipv6Payload1) because the last 8 bytes of + // fragmentExtHdrLen+8+len(ipv6Payload1Addr1ToAddr2) because the last 8 bytes of // the 16 byte routing extension header is in this fagment. - fragmentExtHdrLen+8+len(ipv6Payload1), + fragmentExtHdrLen+8+len(ipv6Payload1Addr1ToAddr2), []buffer.View{ // Fragment extension header. // @@ -1069,7 +1216,7 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Routing extension header (part 2) buffer.View([]byte{6, 7, 8, 9, 10, 11, 12, 13}), - ipv6Payload1, + ipv6Payload1Addr1ToAddr2, }, ), }, @@ -1082,6 +1229,8 @@ func TestReceiveIPv6Fragments(t *testing.T) { name: "Two fragments with atomic", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( fragmentExtHdrLen+64, @@ -1091,47 +1240,53 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, // This fragment has the same ID as the other fragments but is an atomic // fragment. It should not interfere with the other fragments. { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload2), + fragmentExtHdrLen+len(ipv6Payload2Addr1ToAddr2), []buffer.View{ // Fragment extension header. // // Fragment offset = 0, More = false, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 0, 0, 0, 0, 1}), - ipv6Payload2, + ipv6Payload2Addr1ToAddr2, }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1)-64, + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Fragment extension header. // // Fragment offset = 8, More = false, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, }, - expectedPayloads: [][]byte{udpPayload2, udpPayload1}, + expectedPayloads: [][]byte{udpPayload2Addr1ToAddr2, udpPayload1Addr1ToAddr2}, }, { name: "Two interleaved fragmented packets", fragments: []fragmentData{ { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( fragmentExtHdrLen+64, @@ -1141,11 +1296,13 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), - ipv6Payload1[:64], + ipv6Payload1Addr1ToAddr2[:64], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( fragmentExtHdrLen+32, @@ -1155,40 +1312,114 @@ func TestReceiveIPv6Fragments(t *testing.T) { // Fragment offset = 0, More = true, ID = 2 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 2}), - ipv6Payload2[:32], + ipv6Payload2Addr1ToAddr2[:32], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload1)-64, + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, []buffer.View{ // Fragment extension header. // // Fragment offset = 8, More = false, ID = 1 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), - ipv6Payload1[64:], + ipv6Payload1Addr1ToAddr2[64:], }, ), }, { + srcAddr: addr1, + dstAddr: addr2, nextHdr: fragmentExtHdrID, data: buffer.NewVectorisedView( - fragmentExtHdrLen+len(ipv6Payload2)-32, + fragmentExtHdrLen+len(ipv6Payload2Addr1ToAddr2)-32, []buffer.View{ // Fragment extension header. // // Fragment offset = 4, More = false, ID = 2 buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 32, 0, 0, 0, 2}), - ipv6Payload2[32:], + ipv6Payload2Addr1ToAddr2[32:], + }, + ), + }, + }, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2, udpPayload2Addr1ToAddr2}, + }, + { + name: "Two interleaved fragmented packets from different sources but with same ID", + fragments: []fragmentData{ + { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+64, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 0, More = true, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), + + ipv6Payload1Addr1ToAddr2[:64], + }, + ), + }, + { + srcAddr: addr3, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+32, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 0, More = true, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 1, 0, 0, 0, 1}), + + ipv6Payload1Addr3ToAddr2[:32], + }, + ), + }, + { + srcAddr: addr1, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-64, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 8, More = false, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 64, 0, 0, 0, 1}), + + ipv6Payload1Addr1ToAddr2[64:], + }, + ), + }, + { + srcAddr: addr3, + dstAddr: addr2, + nextHdr: fragmentExtHdrID, + data: buffer.NewVectorisedView( + fragmentExtHdrLen+len(ipv6Payload1Addr1ToAddr2)-32, + []buffer.View{ + // Fragment extension header. + // + // Fragment offset = 4, More = false, ID = 1 + buffer.View([]byte{uint8(header.UDPProtocolNumber), 0, 0, 32, 0, 0, 0, 1}), + + ipv6Payload1Addr3ToAddr2[32:], }, ), }, }, - expectedPayloads: [][]byte{udpPayload1, udpPayload2}, + expectedPayloads: [][]byte{udpPayload1Addr1ToAddr2, udpPayload1Addr3ToAddr2}, }, } @@ -1231,8 +1462,8 @@ func TestReceiveIPv6Fragments(t *testing.T) { PayloadLength: uint16(f.data.Size()), NextHeader: f.nextHdr, HopLimit: 255, - SrcAddr: addr1, - DstAddr: addr2, + SrcAddr: f.srcAddr, + DstAddr: f.dstAddr, }) vv := hdr.View().ToVectorisedView() diff --git a/pkg/tcpip/stack/BUILD b/pkg/tcpip/stack/BUILD index 6b9a6b316..1c58bed2d 100644 --- a/pkg/tcpip/stack/BUILD +++ b/pkg/tcpip/stack/BUILD @@ -16,6 +16,18 @@ go_template_instance( ) go_template_instance( + name = "neighbor_entry_list", + out = "neighbor_entry_list.go", + package = "stack", + prefix = "neighborEntry", + template = "//pkg/ilist:generic_list", + types = { + "Element": "*neighborEntry", + "Linker": "*neighborEntry", + }, +) + +go_template_instance( name = "packet_buffer_list", out = "packet_buffer_list.go", package = "stack", @@ -53,7 +65,12 @@ go_library( "linkaddrcache.go", "linkaddrentry_list.go", "ndp.go", + "neighbor_cache.go", + "neighbor_entry.go", + "neighbor_entry_list.go", + "neighborstate_string.go", "nic.go", + "nud.go", "packet_buffer.go", "packet_buffer_list.go", "rand.go", @@ -89,6 +106,7 @@ go_test( size = "medium", srcs = [ "ndp_test.go", + "nud_test.go", "stack_test.go", "transport_demuxer_test.go", "transport_test.go", @@ -110,6 +128,7 @@ go_test( "//pkg/tcpip/transport/udp", "//pkg/waiter", "@com_github_google_go_cmp//cmp:go_default_library", + "@com_github_google_go_cmp//cmp/cmpopts:go_default_library", ], ) @@ -117,8 +136,11 @@ go_test( name = "stack_test", size = "small", srcs = [ + "fake_time_test.go", "forwarder_test.go", "linkaddrcache_test.go", + "neighbor_cache_test.go", + "neighbor_entry_test.go", "nic_test.go", ], library = ":stack", @@ -128,5 +150,8 @@ go_test( "//pkg/tcpip", "//pkg/tcpip/buffer", "//pkg/tcpip/header", + "@com_github_dpjacques_clockwork//:go_default_library", + "@com_github_google_go_cmp//cmp:go_default_library", + "@com_github_google_go_cmp//cmp/cmpopts:go_default_library", ], ) diff --git a/pkg/tcpip/stack/conntrack.go b/pkg/tcpip/stack/conntrack.go index 559a1c4dd..470c265aa 100644 --- a/pkg/tcpip/stack/conntrack.go +++ b/pkg/tcpip/stack/conntrack.go @@ -240,7 +240,10 @@ func (ct *ConnTrack) connFor(pkt *PacketBuffer) (*conn, direction) { if err != nil { return nil, dirOriginal } + return ct.connForTID(tid) +} +func (ct *ConnTrack) connForTID(tid tupleID) (*conn, direction) { bucket := ct.bucket(tid) now := time.Now() @@ -604,3 +607,26 @@ func (ct *ConnTrack) reapTupleLocked(tuple *tuple, bucket int, now time.Time) bo return true } + +func (ct *ConnTrack) originalDst(epID TransportEndpointID) (tcpip.Address, uint16, *tcpip.Error) { + // Lookup the connection. The reply's original destination + // describes the original address. + tid := tupleID{ + srcAddr: epID.LocalAddress, + srcPort: epID.LocalPort, + dstAddr: epID.RemoteAddress, + dstPort: epID.RemotePort, + transProto: header.TCPProtocolNumber, + netProto: header.IPv4ProtocolNumber, + } + conn, _ := ct.connForTID(tid) + if conn == nil { + // Not a tracked connection. + return "", 0, tcpip.ErrNotConnected + } else if conn.manip == manipNone { + // Unmanipulated connection. + return "", 0, tcpip.ErrInvalidOptionValue + } + + return conn.original.dstAddr, conn.original.dstPort, nil +} diff --git a/pkg/tcpip/stack/fake_time_test.go b/pkg/tcpip/stack/fake_time_test.go new file mode 100644 index 000000000..92c8cb534 --- /dev/null +++ b/pkg/tcpip/stack/fake_time_test.go @@ -0,0 +1,209 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "container/heap" + "sync" + "time" + + "github.com/dpjacques/clockwork" + "gvisor.dev/gvisor/pkg/tcpip" +) + +type fakeClock struct { + clock clockwork.FakeClock + + // mu protects the fields below. + mu sync.RWMutex + + // times is min-heap of times. A heap is used for quick retrieval of the next + // upcoming time of scheduled work. + times *timeHeap + + // waitGroups stores one WaitGroup for all work scheduled to execute at the + // same time via AfterFunc. This allows parallel execution of all functions + // passed to AfterFunc scheduled for the same time. + waitGroups map[time.Time]*sync.WaitGroup +} + +func newFakeClock() *fakeClock { + return &fakeClock{ + clock: clockwork.NewFakeClock(), + times: &timeHeap{}, + waitGroups: make(map[time.Time]*sync.WaitGroup), + } +} + +var _ tcpip.Clock = (*fakeClock)(nil) + +// NowNanoseconds implements tcpip.Clock.NowNanoseconds. +func (fc *fakeClock) NowNanoseconds() int64 { + return fc.clock.Now().UnixNano() +} + +// NowMonotonic implements tcpip.Clock.NowMonotonic. +func (fc *fakeClock) NowMonotonic() int64 { + return fc.NowNanoseconds() +} + +// AfterFunc implements tcpip.Clock.AfterFunc. +func (fc *fakeClock) AfterFunc(d time.Duration, f func()) tcpip.Timer { + until := fc.clock.Now().Add(d) + wg := fc.addWait(until) + return &fakeTimer{ + clock: fc, + until: until, + timer: fc.clock.AfterFunc(d, func() { + defer wg.Done() + f() + }), + } +} + +// addWait adds an additional wait to the WaitGroup for parallel execution of +// all work scheduled for t. Returns a reference to the WaitGroup modified. +func (fc *fakeClock) addWait(t time.Time) *sync.WaitGroup { + fc.mu.RLock() + wg, ok := fc.waitGroups[t] + fc.mu.RUnlock() + + if ok { + wg.Add(1) + return wg + } + + fc.mu.Lock() + heap.Push(fc.times, t) + fc.mu.Unlock() + + wg = &sync.WaitGroup{} + wg.Add(1) + + fc.mu.Lock() + fc.waitGroups[t] = wg + fc.mu.Unlock() + + return wg +} + +// removeWait removes a wait from the WaitGroup for parallel execution of all +// work scheduled for t. +func (fc *fakeClock) removeWait(t time.Time) { + fc.mu.RLock() + defer fc.mu.RUnlock() + + wg := fc.waitGroups[t] + wg.Done() +} + +// advance executes all work that have been scheduled to execute within d from +// the current fake time. Blocks until all work has completed execution. +func (fc *fakeClock) advance(d time.Duration) { + // Block until all the work is done + until := fc.clock.Now().Add(d) + for { + fc.mu.Lock() + if fc.times.Len() == 0 { + fc.mu.Unlock() + return + } + + t := heap.Pop(fc.times).(time.Time) + if t.After(until) { + // No work to do + heap.Push(fc.times, t) + fc.mu.Unlock() + return + } + fc.mu.Unlock() + + diff := t.Sub(fc.clock.Now()) + fc.clock.Advance(diff) + + fc.mu.RLock() + wg := fc.waitGroups[t] + fc.mu.RUnlock() + + wg.Wait() + + fc.mu.Lock() + delete(fc.waitGroups, t) + fc.mu.Unlock() + } +} + +type fakeTimer struct { + clock *fakeClock + timer clockwork.Timer + + mu sync.RWMutex + until time.Time +} + +var _ tcpip.Timer = (*fakeTimer)(nil) + +// Reset implements tcpip.Timer.Reset. +func (ft *fakeTimer) Reset(d time.Duration) { + if !ft.timer.Reset(d) { + return + } + + ft.mu.Lock() + defer ft.mu.Unlock() + + ft.clock.removeWait(ft.until) + ft.until = ft.clock.clock.Now().Add(d) + ft.clock.addWait(ft.until) +} + +// Stop implements tcpip.Timer.Stop. +func (ft *fakeTimer) Stop() bool { + if !ft.timer.Stop() { + return false + } + + ft.mu.RLock() + defer ft.mu.RUnlock() + + ft.clock.removeWait(ft.until) + return true +} + +type timeHeap []time.Time + +var _ heap.Interface = (*timeHeap)(nil) + +func (h timeHeap) Len() int { + return len(h) +} + +func (h timeHeap) Less(i, j int) bool { + return h[i].Before(h[j]) +} + +func (h timeHeap) Swap(i, j int) { + h[i], h[j] = h[j], h[i] +} + +func (h *timeHeap) Push(x interface{}) { + *h = append(*h, x.(time.Time)) +} + +func (h *timeHeap) Pop() interface{} { + last := (*h)[len(*h)-1] + *h = (*h)[:len(*h)-1] + return last +} diff --git a/pkg/tcpip/stack/iptables.go b/pkg/tcpip/stack/iptables.go index cbbae4224..110ba073d 100644 --- a/pkg/tcpip/stack/iptables.go +++ b/pkg/tcpip/stack/iptables.go @@ -218,19 +218,16 @@ func (it *IPTables) Check(hook Hook, pkt *PacketBuffer, gso *GSO, r *Route, addr // Many users never configure iptables. Spare them the cost of rule // traversal if rules have never been set. it.mu.RLock() + defer it.mu.RUnlock() if !it.modified { - it.mu.RUnlock() return true } - it.mu.RUnlock() // Packets are manipulated only if connection and matching // NAT rule exists. shouldTrack := it.connections.handlePacket(pkt, hook, gso, r) // Go through each table containing the hook. - it.mu.RLock() - defer it.mu.RUnlock() priorities := it.priorities[hook] for _, tableID := range priorities { // If handlePacket already NATed the packet, we don't need to @@ -418,3 +415,9 @@ func (it *IPTables) checkRule(hook Hook, pkt *PacketBuffer, table Table, ruleIdx // All the matchers matched, so run the target. return rule.Target.Action(pkt, &it.connections, hook, gso, r, address) } + +// OriginalDst returns the original destination of redirected connections. It +// returns an error if the connection doesn't exist or isn't redirected. +func (it *IPTables) OriginalDst(epID TransportEndpointID) (tcpip.Address, uint16, *tcpip.Error) { + return it.connections.originalDst(epID) +} diff --git a/pkg/tcpip/stack/ndp.go b/pkg/tcpip/stack/ndp.go index 9dce11a97..5174e639c 100644 --- a/pkg/tcpip/stack/ndp.go +++ b/pkg/tcpip/stack/ndp.go @@ -33,12 +33,6 @@ const ( // Default = 1 (from RFC 4862 section 5.1) defaultDupAddrDetectTransmits = 1 - // defaultRetransmitTimer is the default amount of time to wait between - // sending NDP Neighbor solicitation messages. - // - // Default = 1s (from RFC 4861 section 10). - defaultRetransmitTimer = time.Second - // defaultMaxRtrSolicitations is the default number of Router // Solicitation messages to send when a NIC becomes enabled. // @@ -79,16 +73,6 @@ const ( // Default = true. defaultAutoGenGlobalAddresses = true - // minimumRetransmitTimer is the minimum amount of time to wait between - // sending NDP Neighbor solicitation messages. Note, RFC 4861 does - // not impose a minimum Retransmit Timer, but we do here to make sure - // the messages are not sent all at once. We also come to this value - // because in the RetransmitTimer field of a Router Advertisement, a - // value of 0 means unspecified, so the smallest valid value is 1. - // Note, the unit of the RetransmitTimer field in the Router - // Advertisement is milliseconds. - minimumRetransmitTimer = time.Millisecond - // minimumRtrSolicitationInterval is the minimum amount of time to wait // between sending Router Solicitation messages. This limit is imposed // to make sure that Router Solicitation messages are not sent all at diff --git a/pkg/tcpip/stack/neighbor_cache.go b/pkg/tcpip/stack/neighbor_cache.go new file mode 100644 index 000000000..1d37716c2 --- /dev/null +++ b/pkg/tcpip/stack/neighbor_cache.go @@ -0,0 +1,335 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "fmt" + "time" + + "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/sync" + "gvisor.dev/gvisor/pkg/tcpip" +) + +const neighborCacheSize = 512 // max entries per interface + +// neighborCache maps IP addresses to link addresses. It uses the Least +// Recently Used (LRU) eviction strategy to implement a bounded cache for +// dynmically acquired entries. It contains the state machine and configuration +// for running Neighbor Unreachability Detection (NUD). +// +// There are two types of entries in the neighbor cache: +// 1. Dynamic entries are discovered automatically by neighbor discovery +// protocols (e.g. ARP, NDP). These protocols will attempt to reconfirm +// reachability with the device once the entry's state becomes Stale. +// 2. Static entries are explicitly added by a user and have no expiration. +// Their state is always Static. The amount of static entries stored in the +// cache is unbounded. +// +// neighborCache implements NUDHandler. +type neighborCache struct { + nic *NIC + state *NUDState + + // mu protects the fields below. + mu sync.RWMutex + + cache map[tcpip.Address]*neighborEntry + dynamic struct { + lru neighborEntryList + + // count tracks the amount of dynamic entries in the cache. This is + // needed since static entries do not count towards the LRU cache + // eviction strategy. + count uint16 + } +} + +var _ NUDHandler = (*neighborCache)(nil) + +// getOrCreateEntry retrieves a cache entry associated with addr. The +// returned entry is always refreshed in the cache (it is reachable via the +// map, and its place is bumped in LRU). +// +// If a matching entry exists in the cache, it is returned. If no matching +// entry exists and the cache is full, an existing entry is evicted via LRU, +// reset to state incomplete, and returned. If no matching entry exists and the +// cache is not full, a new entry with state incomplete is allocated and +// returned. +func (n *neighborCache) getOrCreateEntry(remoteAddr, localAddr tcpip.Address, linkRes LinkAddressResolver) *neighborEntry { + n.mu.Lock() + defer n.mu.Unlock() + + if entry, ok := n.cache[remoteAddr]; ok { + entry.mu.RLock() + if entry.neigh.State != Static { + n.dynamic.lru.Remove(entry) + n.dynamic.lru.PushFront(entry) + } + entry.mu.RUnlock() + return entry + } + + // The entry that needs to be created must be dynamic since all static + // entries are directly added to the cache via addStaticEntry. + entry := newNeighborEntry(n.nic, remoteAddr, localAddr, n.state, linkRes) + if n.dynamic.count == neighborCacheSize { + e := n.dynamic.lru.Back() + e.mu.Lock() + + delete(n.cache, e.neigh.Addr) + n.dynamic.lru.Remove(e) + n.dynamic.count-- + + e.dispatchRemoveEventLocked() + e.setStateLocked(Unknown) + e.notifyWakersLocked() + e.mu.Unlock() + } + n.cache[remoteAddr] = entry + n.dynamic.lru.PushFront(entry) + n.dynamic.count++ + return entry +} + +// entry looks up the neighbor cache for translating address to link address +// (e.g. IP -> MAC). If the LinkEndpoint requests address resolution and there +// is a LinkAddressResolver registered with the network protocol, the cache +// attempts to resolve the address and returns ErrWouldBlock. If a Waker is +// provided, it will be notified when address resolution is complete (success +// or not). +// +// If address resolution is required, ErrNoLinkAddress and a notification +// channel is returned for the top level caller to block. Channel is closed +// once address resolution is complete (success or not). +func (n *neighborCache) entry(remoteAddr, localAddr tcpip.Address, linkRes LinkAddressResolver, w *sleep.Waker) (NeighborEntry, <-chan struct{}, *tcpip.Error) { + if linkRes != nil { + if linkAddr, ok := linkRes.ResolveStaticAddress(remoteAddr); ok { + e := NeighborEntry{ + Addr: remoteAddr, + LocalAddr: localAddr, + LinkAddr: linkAddr, + State: Static, + UpdatedAt: time.Now(), + } + return e, nil, nil + } + } + + entry := n.getOrCreateEntry(remoteAddr, localAddr, linkRes) + entry.mu.Lock() + defer entry.mu.Unlock() + + switch s := entry.neigh.State; s { + case Reachable, Static: + return entry.neigh, nil, nil + + case Unknown, Incomplete, Stale, Delay, Probe: + entry.addWakerLocked(w) + + if entry.done == nil { + // Address resolution needs to be initiated. + if linkRes == nil { + return entry.neigh, nil, tcpip.ErrNoLinkAddress + } + entry.done = make(chan struct{}) + } + + entry.handlePacketQueuedLocked() + return entry.neigh, entry.done, tcpip.ErrWouldBlock + + case Failed: + return entry.neigh, nil, tcpip.ErrNoLinkAddress + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", s)) + } +} + +// removeWaker removes a waker that has been added when link resolution for +// addr was requested. +func (n *neighborCache) removeWaker(addr tcpip.Address, waker *sleep.Waker) { + n.mu.Lock() + if entry, ok := n.cache[addr]; ok { + delete(entry.wakers, waker) + } + n.mu.Unlock() +} + +// entries returns all entries in the neighbor cache. +func (n *neighborCache) entries() []NeighborEntry { + entries := make([]NeighborEntry, 0, len(n.cache)) + n.mu.RLock() + for _, entry := range n.cache { + entry.mu.RLock() + entries = append(entries, entry.neigh) + entry.mu.RUnlock() + } + n.mu.RUnlock() + return entries +} + +// addStaticEntry adds a static entry to the neighbor cache, mapping an IP +// address to a link address. If a dynamic entry exists in the neighbor cache +// with the same address, it will be replaced with this static entry. If a +// static entry exists with the same address but different link address, it +// will be updated with the new link address. If a static entry exists with the +// same address and link address, nothing will happen. +func (n *neighborCache) addStaticEntry(addr tcpip.Address, linkAddr tcpip.LinkAddress) { + n.mu.Lock() + defer n.mu.Unlock() + + if entry, ok := n.cache[addr]; ok { + entry.mu.Lock() + if entry.neigh.State != Static { + // Dynamic entry found with the same address. + n.dynamic.lru.Remove(entry) + n.dynamic.count-- + } else if entry.neigh.LinkAddr == linkAddr { + // Static entry found with the same address and link address. + entry.mu.Unlock() + return + } else { + // Static entry found with the same address but different link address. + entry.neigh.LinkAddr = linkAddr + entry.dispatchChangeEventLocked(entry.neigh.State) + entry.mu.Unlock() + return + } + + // Notify that resolution has been interrupted, just in case the entry was + // in the Incomplete or Probe state. + entry.dispatchRemoveEventLocked() + entry.setStateLocked(Unknown) + entry.notifyWakersLocked() + entry.mu.Unlock() + } + + entry := newStaticNeighborEntry(n.nic, addr, linkAddr, n.state) + n.cache[addr] = entry +} + +// removeEntryLocked removes the specified entry from the neighbor cache. +func (n *neighborCache) removeEntryLocked(entry *neighborEntry) { + if entry.neigh.State != Static { + n.dynamic.lru.Remove(entry) + n.dynamic.count-- + } + if entry.neigh.State != Failed { + entry.dispatchRemoveEventLocked() + } + entry.setStateLocked(Unknown) + entry.notifyWakersLocked() + + delete(n.cache, entry.neigh.Addr) +} + +// removeEntry removes a dynamic or static entry by address from the neighbor +// cache. Returns true if the entry was found and deleted. +func (n *neighborCache) removeEntry(addr tcpip.Address) bool { + n.mu.Lock() + defer n.mu.Unlock() + + entry, ok := n.cache[addr] + if !ok { + return false + } + + entry.mu.Lock() + defer entry.mu.Unlock() + + n.removeEntryLocked(entry) + return true +} + +// clear removes all dynamic and static entries from the neighbor cache. +func (n *neighborCache) clear() { + n.mu.Lock() + defer n.mu.Unlock() + + for _, entry := range n.cache { + entry.mu.Lock() + entry.dispatchRemoveEventLocked() + entry.setStateLocked(Unknown) + entry.notifyWakersLocked() + entry.mu.Unlock() + } + + n.dynamic.lru = neighborEntryList{} + n.cache = make(map[tcpip.Address]*neighborEntry) + n.dynamic.count = 0 +} + +// config returns the NUD configuration. +func (n *neighborCache) config() NUDConfigurations { + return n.state.Config() +} + +// setConfig changes the NUD configuration. +// +// If config contains invalid NUD configuration values, it will be fixed to +// use default values for the erroneous values. +func (n *neighborCache) setConfig(config NUDConfigurations) { + config.resetInvalidFields() + n.state.SetConfig(config) +} + +// HandleProbe implements NUDHandler.HandleProbe by following the logic defined +// in RFC 4861 section 7.2.3. Validation of the probe is expected to be handled +// by the caller. +func (n *neighborCache) HandleProbe(remoteAddr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress) { + entry := n.getOrCreateEntry(remoteAddr, localAddr, nil) + entry.mu.Lock() + entry.handleProbeLocked(remoteLinkAddr) + entry.mu.Unlock() +} + +// HandleConfirmation implements NUDHandler.HandleConfirmation by following the +// logic defined in RFC 4861 section 7.2.5. +// +// TODO(gvisor.dev/issue/2277): To protect against ARP poisoning and other +// attacks against NDP functions, Secure Neighbor Discovery (SEND) Protocol +// should be deployed where preventing access to the broadcast segment might +// not be possible. SEND uses RSA key pairs to produce cryptographically +// generated addresses, as defined in RFC 3972, Cryptographically Generated +// Addresses (CGA). This ensures that the claimed source of an NDP message is +// the owner of the claimed address. +func (n *neighborCache) HandleConfirmation(addr tcpip.Address, linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) { + n.mu.RLock() + entry, ok := n.cache[addr] + n.mu.RUnlock() + if ok { + entry.mu.Lock() + entry.handleConfirmationLocked(linkAddr, flags) + entry.mu.Unlock() + } + // The confirmation SHOULD be silently discarded if the recipient did not + // initiate any communication with the target. This is indicated if there is + // no matching entry for the remote address. +} + +// HandleUpperLevelConfirmation implements +// NUDHandler.HandleUpperLevelConfirmation by following the logic defined in +// RFC 4861 section 7.3.1. +func (n *neighborCache) HandleUpperLevelConfirmation(addr tcpip.Address) { + n.mu.RLock() + entry, ok := n.cache[addr] + n.mu.RUnlock() + if ok { + entry.mu.Lock() + entry.handleUpperLevelConfirmationLocked() + entry.mu.Unlock() + } +} diff --git a/pkg/tcpip/stack/neighbor_cache_test.go b/pkg/tcpip/stack/neighbor_cache_test.go new file mode 100644 index 000000000..4cb2c9c6b --- /dev/null +++ b/pkg/tcpip/stack/neighbor_cache_test.go @@ -0,0 +1,1752 @@ +// Copyright 2019 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "bytes" + "encoding/binary" + "fmt" + "math" + "math/rand" + "strings" + "sync" + "sync/atomic" + "testing" + "time" + + "github.com/google/go-cmp/cmp" + "github.com/google/go-cmp/cmp/cmpopts" + "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/tcpip" +) + +const ( + // entryStoreSize is the default number of entries that will be generated and + // added to the entry store. This number needs to be larger than the size of + // the neighbor cache to give ample opportunity for verifying behavior during + // cache overflows. Four times the size of the neighbor cache allows for + // three complete cache overflows. + entryStoreSize = 4 * neighborCacheSize + + // typicalLatency is the typical latency for an ARP or NDP packet to travel + // to a router and back. + typicalLatency = time.Millisecond + + // testEntryBroadcastAddr is a special address that indicates a packet should + // be sent to all nodes. + testEntryBroadcastAddr = tcpip.Address("broadcast") + + // testEntryLocalAddr is the source address of neighbor probes. + testEntryLocalAddr = tcpip.Address("local_addr") + + // testEntryBroadcastLinkAddr is a special link address sent back to + // multicast neighbor probes. + testEntryBroadcastLinkAddr = tcpip.LinkAddress("mac_broadcast") + + // infiniteDuration indicates that a task will not occur in our lifetime. + infiniteDuration = time.Duration(math.MaxInt64) +) + +// entryDiffOpts returns the options passed to cmp.Diff to compare neighbor +// entries. The UpdatedAt field is ignored due to a lack of a deterministic +// method to predict the time that an event will be dispatched. +func entryDiffOpts() []cmp.Option { + return []cmp.Option{ + cmpopts.IgnoreFields(NeighborEntry{}, "UpdatedAt"), + } +} + +// entryDiffOptsWithSort is like entryDiffOpts but also includes an option to +// sort slices of entries for cases where ordering must be ignored. +func entryDiffOptsWithSort() []cmp.Option { + return []cmp.Option{ + cmpopts.IgnoreFields(NeighborEntry{}, "UpdatedAt"), + cmpopts.SortSlices(func(a, b NeighborEntry) bool { + return strings.Compare(string(a.Addr), string(b.Addr)) < 0 + }), + } +} + +func newTestNeighborCache(nudDisp NUDDispatcher, config NUDConfigurations, clock tcpip.Clock) *neighborCache { + config.resetInvalidFields() + rng := rand.New(rand.NewSource(time.Now().UnixNano())) + return &neighborCache{ + nic: &NIC{ + stack: &Stack{ + clock: clock, + nudDisp: nudDisp, + }, + id: 1, + }, + state: NewNUDState(config, rng), + cache: make(map[tcpip.Address]*neighborEntry, neighborCacheSize), + } +} + +// testEntryStore contains a set of IP to NeighborEntry mappings. +type testEntryStore struct { + mu sync.RWMutex + entriesMap map[tcpip.Address]NeighborEntry +} + +func toAddress(i int) tcpip.Address { + buf := new(bytes.Buffer) + binary.Write(buf, binary.BigEndian, uint8(1)) + binary.Write(buf, binary.BigEndian, uint8(0)) + binary.Write(buf, binary.BigEndian, uint16(i)) + return tcpip.Address(buf.String()) +} + +func toLinkAddress(i int) tcpip.LinkAddress { + buf := new(bytes.Buffer) + binary.Write(buf, binary.BigEndian, uint8(1)) + binary.Write(buf, binary.BigEndian, uint8(0)) + binary.Write(buf, binary.BigEndian, uint32(i)) + return tcpip.LinkAddress(buf.String()) +} + +// newTestEntryStore returns a testEntryStore pre-populated with entries. +func newTestEntryStore() *testEntryStore { + store := &testEntryStore{ + entriesMap: make(map[tcpip.Address]NeighborEntry), + } + for i := 0; i < entryStoreSize; i++ { + addr := toAddress(i) + linkAddr := toLinkAddress(i) + + store.entriesMap[addr] = NeighborEntry{ + Addr: addr, + LocalAddr: testEntryLocalAddr, + LinkAddr: linkAddr, + } + } + return store +} + +// size returns the number of entries in the store. +func (s *testEntryStore) size() int { + s.mu.RLock() + defer s.mu.RUnlock() + return len(s.entriesMap) +} + +// entry returns the entry at index i. Returns an empty entry and false if i is +// out of bounds. +func (s *testEntryStore) entry(i int) (NeighborEntry, bool) { + return s.entryByAddr(toAddress(i)) +} + +// entryByAddr returns the entry matching addr for situations when the index is +// not available. Returns an empty entry and false if no entries match addr. +func (s *testEntryStore) entryByAddr(addr tcpip.Address) (NeighborEntry, bool) { + s.mu.RLock() + defer s.mu.RUnlock() + entry, ok := s.entriesMap[addr] + return entry, ok +} + +// entries returns all entries in the store. +func (s *testEntryStore) entries() []NeighborEntry { + entries := make([]NeighborEntry, 0, len(s.entriesMap)) + s.mu.RLock() + defer s.mu.RUnlock() + for i := 0; i < entryStoreSize; i++ { + addr := toAddress(i) + if entry, ok := s.entriesMap[addr]; ok { + entries = append(entries, entry) + } + } + return entries +} + +// set modifies the link addresses of an entry. +func (s *testEntryStore) set(i int, linkAddr tcpip.LinkAddress) { + addr := toAddress(i) + s.mu.Lock() + defer s.mu.Unlock() + if entry, ok := s.entriesMap[addr]; ok { + entry.LinkAddr = linkAddr + s.entriesMap[addr] = entry + } +} + +// testNeighborResolver implements LinkAddressResolver to emulate sending a +// neighbor probe. +type testNeighborResolver struct { + clock tcpip.Clock + neigh *neighborCache + entries *testEntryStore + delay time.Duration + onLinkAddressRequest func() +} + +var _ LinkAddressResolver = (*testNeighborResolver)(nil) + +func (r *testNeighborResolver) LinkAddressRequest(addr, localAddr tcpip.Address, linkAddr tcpip.LinkAddress, linkEP LinkEndpoint) *tcpip.Error { + // Delay handling the request to emulate network latency. + r.clock.AfterFunc(r.delay, func() { + r.fakeRequest(addr) + }) + + // Execute post address resolution action, if available. + if f := r.onLinkAddressRequest; f != nil { + f() + } + return nil +} + +// fakeRequest emulates handling a response for a link address request. +func (r *testNeighborResolver) fakeRequest(addr tcpip.Address) { + if entry, ok := r.entries.entryByAddr(addr); ok { + r.neigh.HandleConfirmation(addr, entry.LinkAddr, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + } +} + +func (*testNeighborResolver) ResolveStaticAddress(addr tcpip.Address) (tcpip.LinkAddress, bool) { + if addr == testEntryBroadcastAddr { + return testEntryBroadcastLinkAddr, true + } + return "", false +} + +func (*testNeighborResolver) LinkAddressProtocol() tcpip.NetworkProtocolNumber { + return 0 +} + +type entryEvent struct { + nicID tcpip.NICID + address tcpip.Address + linkAddr tcpip.LinkAddress + state NeighborState +} + +func TestNeighborCacheGetConfig(t *testing.T) { + nudDisp := testNUDDispatcher{} + c := DefaultNUDConfigurations() + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, c, clock) + + if got, want := neigh.config(), c; got != want { + t.Errorf("got neigh.config() = %+v, want = %+v", got, want) + } + + // No events should have been dispatched. + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheSetConfig(t *testing.T) { + nudDisp := testNUDDispatcher{} + c := DefaultNUDConfigurations() + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, c, clock) + + c.MinRandomFactor = 1 + c.MaxRandomFactor = 1 + neigh.setConfig(c) + + if got, want := neigh.config(), c; got != want { + t.Errorf("got neigh.config() = %+v, want = %+v", got, want) + } + + // No events should have been dispatched. + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheEntry(t *testing.T) { + c := DefaultNUDConfigurations() + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, c, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + + clock.advance(typicalLatency) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.events = nil + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != nil { + t.Fatalf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) + } + + // No more events should have been dispatched. + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +// TestNeighborCacheEntryNoLinkAddress verifies calling entry() without a +// LinkAddressResolver returns ErrNoLinkAddress. +func TestNeighborCacheEntryNoLinkAddress(t *testing.T) { + nudDisp := testNUDDispatcher{} + c := DefaultNUDConfigurations() + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, c, clock) + store := newTestEntryStore() + + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, nil, nil) + if err != tcpip.ErrNoLinkAddress { + t.Errorf("got neigh.entry(%s, %s, nil, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrNoLinkAddress) + } + + // No events should have been dispatched. + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheRemoveEntry(t *testing.T) { + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + + clock.advance(typicalLatency) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.events = nil + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + neigh.removeEntry(entry.Addr) + + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } +} + +type testContext struct { + clock *fakeClock + neigh *neighborCache + store *testEntryStore + linkRes *testNeighborResolver + nudDisp *testNUDDispatcher +} + +func newTestContext(c NUDConfigurations) testContext { + nudDisp := &testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(nudDisp, c, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + return testContext{ + clock: clock, + neigh: neigh, + store: store, + linkRes: linkRes, + nudDisp: nudDisp, + } +} + +type overflowOptions struct { + startAtEntryIndex int + wantStaticEntries []NeighborEntry +} + +func (c *testContext) overflowCache(opts overflowOptions) error { + // Fill the neighbor cache to capacity to verify the LRU eviction strategy is + // working properly after the entry removal. + for i := opts.startAtEntryIndex; i < c.store.size(); i++ { + // Add a new entry + entry, ok := c.store.entry(i) + if !ok { + return fmt.Errorf("c.store.entry(%d) not found", i) + } + if _, _, err := c.neigh.entry(entry.Addr, entry.LocalAddr, c.linkRes, nil); err != tcpip.ErrWouldBlock { + return fmt.Errorf("got c.neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + c.clock.advance(c.neigh.config().RetransmitTimer) + + var wantEvents []testEntryEventInfo + + // When beyond the full capacity, the cache will evict an entry as per the + // LRU eviction strategy. Note that the number of static entries should not + // affect the total number of dynamic entries that can be added. + if i >= neighborCacheSize+opts.startAtEntryIndex { + removedEntry, ok := c.store.entry(i - neighborCacheSize) + if !ok { + return fmt.Errorf("store.entry(%d) not found", i-neighborCacheSize) + } + wantEvents = append(wantEvents, testEntryEventInfo{ + EventType: entryTestRemoved, + NICID: 1, + Addr: removedEntry.Addr, + LinkAddr: removedEntry.LinkAddr, + State: Reachable, + }) + } + + wantEvents = append(wantEvents, testEntryEventInfo{ + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, testEntryEventInfo{ + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }) + + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + return fmt.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + // Expect to find only the most recent entries. The order of entries reported + // by entries() is undeterministic, so entries have to be sorted before + // comparison. + wantUnsortedEntries := opts.wantStaticEntries + for i := c.store.size() - neighborCacheSize; i < c.store.size(); i++ { + entry, ok := c.store.entry(i) + if !ok { + return fmt.Errorf("c.store.entry(%d) not found", i) + } + wantEntry := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: entry.LinkAddr, + State: Reachable, + } + wantUnsortedEntries = append(wantUnsortedEntries, wantEntry) + } + + if diff := cmp.Diff(c.neigh.entries(), wantUnsortedEntries, entryDiffOptsWithSort()...); diff != "" { + return fmt.Errorf("neighbor entries mismatch (-got, +want):\n%s", diff) + } + + // No more events should have been dispatched. + c.nudDisp.mu.Lock() + defer c.nudDisp.mu.Unlock() + if diff := cmp.Diff(c.nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + return fmt.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + return nil +} + +// TestNeighborCacheOverflow verifies that the LRU cache eviction strategy +// respects the dynamic entry count. +func TestNeighborCacheOverflow(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + c := newTestContext(config) + opts := overflowOptions{ + startAtEntryIndex: 0, + } + if err := c.overflowCache(opts); err != nil { + t.Errorf("c.overflowCache(%+v): %s", opts, err) + } +} + +// TestNeighborCacheRemoveEntryThenOverflow verifies that the LRU cache +// eviction strategy respects the dynamic entry count when an entry is removed. +func TestNeighborCacheRemoveEntryThenOverflow(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + c := newTestContext(config) + + // Add a dynamic entry + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + _, _, err := c.neigh.entry(entry.Addr, entry.LocalAddr, c.linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got c.neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + c.clock.advance(c.neigh.config().RetransmitTimer) + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Remove the entry + c.neigh.removeEntry(entry.Addr) + + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + opts := overflowOptions{ + startAtEntryIndex: 0, + } + if err := c.overflowCache(opts); err != nil { + t.Errorf("c.overflowCache(%+v): %s", opts, err) + } +} + +// TestNeighborCacheDuplicateStaticEntryWithSameLinkAddress verifies that +// adding a duplicate static entry with the same link address does not dispatch +// any events. +func TestNeighborCacheDuplicateStaticEntryWithSameLinkAddress(t *testing.T) { + config := DefaultNUDConfigurations() + c := newTestContext(config) + + // Add a static entry + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + staticLinkAddr := entry.LinkAddr + "static" + c.neigh.addStaticEntry(entry.Addr, staticLinkAddr) + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + LinkAddr: staticLinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Remove the static entry that was just added + c.neigh.addStaticEntry(entry.Addr, staticLinkAddr) + + // No more events should have been dispatched. + c.nudDisp.mu.Lock() + defer c.nudDisp.mu.Unlock() + if diff := cmp.Diff(c.nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +// TestNeighborCacheDuplicateStaticEntryWithDifferentLinkAddress verifies that +// adding a duplicate static entry with a different link address dispatches a +// change event. +func TestNeighborCacheDuplicateStaticEntryWithDifferentLinkAddress(t *testing.T) { + config := DefaultNUDConfigurations() + c := newTestContext(config) + + // Add a static entry + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + staticLinkAddr := entry.LinkAddr + "static" + c.neigh.addStaticEntry(entry.Addr, staticLinkAddr) + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + LinkAddr: staticLinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Add a duplicate entry with a different link address + staticLinkAddr += "duplicate" + c.neigh.addStaticEntry(entry.Addr, staticLinkAddr) + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: staticLinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + defer c.nudDisp.mu.Unlock() + if diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } +} + +// TestNeighborCacheRemoveStaticEntryThenOverflow verifies that the LRU cache +// eviction strategy respects the dynamic entry count when a static entry is +// added then removed. In this case, the dynamic entry count shouldn't have +// been touched. +func TestNeighborCacheRemoveStaticEntryThenOverflow(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + c := newTestContext(config) + + // Add a static entry + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + staticLinkAddr := entry.LinkAddr + "static" + c.neigh.addStaticEntry(entry.Addr, staticLinkAddr) + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + LinkAddr: staticLinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Remove the static entry that was just added + c.neigh.removeEntry(entry.Addr) + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entry.Addr, + LinkAddr: staticLinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + opts := overflowOptions{ + startAtEntryIndex: 0, + } + if err := c.overflowCache(opts); err != nil { + t.Errorf("c.overflowCache(%+v): %s", opts, err) + } +} + +// TestNeighborCacheOverwriteWithStaticEntryThenOverflow verifies that the LRU +// cache eviction strategy keeps count of the dynamic entry count when an entry +// is overwritten by a static entry. Static entries should not count towards +// the size of the LRU cache. +func TestNeighborCacheOverwriteWithStaticEntryThenOverflow(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + c := newTestContext(config) + + // Add a dynamic entry + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + _, _, err := c.neigh.entry(entry.Addr, entry.LocalAddr, c.linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got c.neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + c.clock.advance(typicalLatency) + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Override the entry with a static one using the same address + staticLinkAddr := entry.LinkAddr + "static" + c.neigh.addStaticEntry(entry.Addr, staticLinkAddr) + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + LinkAddr: staticLinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + opts := overflowOptions{ + startAtEntryIndex: 1, + wantStaticEntries: []NeighborEntry{ + { + Addr: entry.Addr, + LocalAddr: "", // static entries don't need a local address + LinkAddr: staticLinkAddr, + State: Static, + }, + }, + } + if err := c.overflowCache(opts); err != nil { + t.Errorf("c.overflowCache(%+v): %s", opts, err) + } +} + +func TestNeighborCacheNotifiesWaker(t *testing.T) { + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + w := sleep.Waker{} + s := sleep.Sleeper{} + const wakerID = 1 + s.AddWaker(&w, wakerID) + + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, &w) + if err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, _ = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + if doneCh == nil { + t.Fatalf("expected done channel from neigh.entry(%s, %s, _, _)", entry.Addr, entry.LocalAddr) + } + clock.advance(typicalLatency) + + select { + case <-doneCh: + default: + t.Fatal("expected notification from done channel") + } + + id, ok := s.Fetch(false /* block */) + if !ok { + t.Errorf("expected waker to be notified after neigh.entry(%s, %s, _, _)", entry.Addr, entry.LocalAddr) + } + if id != wakerID { + t.Errorf("got s.Fetch(false) = %d, want = %d", id, wakerID) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheRemoveWaker(t *testing.T) { + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + w := sleep.Waker{} + s := sleep.Sleeper{} + const wakerID = 1 + s.AddWaker(&w, wakerID) + + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, &w) + if err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, _) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + if doneCh == nil { + t.Fatalf("expected done channel from neigh.entry(%s, %s, _, _)", entry.Addr, entry.LocalAddr) + } + + // Remove the waker before the neighbor cache has the opportunity to send a + // notification. + neigh.removeWaker(entry.Addr, &w) + clock.advance(typicalLatency) + + select { + case <-doneCh: + default: + t.Fatal("expected notification from done channel") + } + + if id, ok := s.Fetch(false /* block */); ok { + t.Errorf("unexpected notification from waker with id %d", id) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheAddStaticEntryThenOverflow(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + c := newTestContext(config) + + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + c.neigh.addStaticEntry(entry.Addr, entry.LinkAddr) + e, _, err := c.neigh.entry(entry.Addr, "", nil, nil) + if err != nil { + t.Errorf("unexpected error from c.neigh.entry(%s, \"\", nil nil): %s", entry.Addr, err) + } + want := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: "", // static entries don't need a local address + LinkAddr: entry.LinkAddr, + State: Static, + } + if diff := cmp.Diff(e, want, entryDiffOpts()...); diff != "" { + t.Errorf("c.neigh.entry(%s, \"\", nil, nil) mismatch (-got, +want):\n%s", entry.Addr, diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Static, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + opts := overflowOptions{ + startAtEntryIndex: 1, + wantStaticEntries: []NeighborEntry{ + { + Addr: entry.Addr, + LocalAddr: "", // static entries don't need a local address + LinkAddr: entry.LinkAddr, + State: Static, + }, + }, + } + if err := c.overflowCache(opts); err != nil { + t.Errorf("c.overflowCache(%+v): %s", opts, err) + } +} + +func TestNeighborCacheClear(t *testing.T) { + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + // Add a dynamic entry. + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + clock.advance(typicalLatency) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.events = nil + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Add a static entry. + neigh.addStaticEntry(entryTestAddr1, entryTestLinkAddr1) + + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Static, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.events = nil + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + // Clear shoud remove both dynamic and static entries. + neigh.clear() + + // Remove events dispatched from clear() have no deterministic order so they + // need to be sorted beforehand. + wantUnsortedEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Static, + }, + } + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, wantUnsortedEvents, eventDiffOptsWithSort()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +// TestNeighborCacheClearThenOverflow verifies that the LRU cache eviction +// strategy keeps count of the dynamic entry count when all entries are +// cleared. +func TestNeighborCacheClearThenOverflow(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + c := newTestContext(config) + + // Add a dynamic entry + entry, ok := c.store.entry(0) + if !ok { + t.Fatalf("c.store.entry(0) not found") + } + _, _, err := c.neigh.entry(entry.Addr, entry.LocalAddr, c.linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got c.neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + c.clock.advance(typicalLatency) + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + + // Clear the cache. + c.neigh.clear() + { + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + c.nudDisp.mu.Lock() + diff := cmp.Diff(c.nudDisp.events, wantEvents, eventDiffOpts()...) + c.nudDisp.events = nil + c.nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + opts := overflowOptions{ + startAtEntryIndex: 0, + } + if err := c.overflowCache(opts); err != nil { + t.Errorf("c.overflowCache(%+v): %s", opts, err) + } +} + +func TestNeighborCacheKeepFrequentlyUsed(t *testing.T) { + config := DefaultNUDConfigurations() + // Stay in Reachable so the cache can overflow + config.BaseReachableTime = infiniteDuration + config.MinRandomFactor = 1 + config.MaxRandomFactor = 1 + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + frequentlyUsedEntry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + + // The following logic is very similar to overflowCache, but + // periodically refreshes the frequently used entry. + + // Fill the neighbor cache to capacity + for i := 0; i < neighborCacheSize; i++ { + entry, ok := store.entry(i) + if !ok { + t.Fatalf("store.entry(%d) not found", i) + } + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + clock.advance(typicalLatency) + select { + case <-doneCh: + default: + t.Fatalf("expected notification from done channel returned by neigh.entry(%s, %s, _, nil)", entry.Addr, entry.LocalAddr) + } + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.events = nil + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + // Keep adding more entries + for i := neighborCacheSize; i < store.size(); i++ { + // Periodically refresh the frequently used entry + if i%(neighborCacheSize/2) == 0 { + _, _, err := neigh.entry(frequentlyUsedEntry.Addr, frequentlyUsedEntry.LocalAddr, linkRes, nil) + if err != nil { + t.Errorf("unexpected error from neigh.entry(%s, %s, _, nil): %s", frequentlyUsedEntry.Addr, frequentlyUsedEntry.LocalAddr, err) + } + } + + entry, ok := store.entry(i) + if !ok { + t.Fatalf("store.entry(%d) not found", i) + } + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + clock.advance(typicalLatency) + select { + case <-doneCh: + default: + t.Fatalf("expected notification from done channel returned by neigh.entry(%s, %s, _, nil)", entry.Addr, entry.LocalAddr) + } + + // An entry should have been removed, as per the LRU eviction strategy + removedEntry, ok := store.entry(i - neighborCacheSize + 1) + if !ok { + t.Fatalf("store.entry(%d) not found", i-neighborCacheSize+1) + } + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestRemoved, + NICID: 1, + Addr: removedEntry.Addr, + LinkAddr: removedEntry.LinkAddr, + State: Reachable, + }, + { + EventType: entryTestAdded, + NICID: 1, + Addr: entry.Addr, + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: 1, + Addr: entry.Addr, + LinkAddr: entry.LinkAddr, + State: Reachable, + }, + } + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.events = nil + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } + + // Expect to find only the frequently used entry and the most recent entries. + // The order of entries reported by entries() is undeterministic, so entries + // have to be sorted before comparison. + wantUnsortedEntries := []NeighborEntry{ + { + Addr: frequentlyUsedEntry.Addr, + LocalAddr: frequentlyUsedEntry.LocalAddr, + LinkAddr: frequentlyUsedEntry.LinkAddr, + State: Reachable, + }, + } + + for i := store.size() - neighborCacheSize + 1; i < store.size(); i++ { + entry, ok := store.entry(i) + if !ok { + t.Fatalf("store.entry(%d) not found", i) + } + wantEntry := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: entry.LinkAddr, + State: Reachable, + } + wantUnsortedEntries = append(wantUnsortedEntries, wantEntry) + } + + if diff := cmp.Diff(neigh.entries(), wantUnsortedEntries, entryDiffOptsWithSort()...); diff != "" { + t.Errorf("neighbor entries mismatch (-got, +want):\n%s", diff) + } + + // No more events should have been dispatched. + nudDisp.mu.Lock() + defer nudDisp.mu.Unlock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheConcurrent(t *testing.T) { + const concurrentProcesses = 16 + + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + storeEntries := store.entries() + for _, entry := range storeEntries { + var wg sync.WaitGroup + for r := 0; r < concurrentProcesses; r++ { + wg.Add(1) + go func(entry NeighborEntry) { + defer wg.Done() + e, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != nil && err != tcpip.ErrWouldBlock { + t.Errorf("got neigh.entry(%s, %s, _, nil) = (%+v, _, %s), want (_, _, nil) or (_, _, %s)", entry.Addr, entry.LocalAddr, e, err, tcpip.ErrWouldBlock) + } + }(entry) + } + + // Wait for all gorountines to send a request + wg.Wait() + + // Process all the requests for a single entry concurrently + clock.advance(typicalLatency) + } + + // All goroutines add in the same order and add more values than can fit in + // the cache. Our eviction strategy requires that the last entries are + // present, up to the size of the neighbor cache, and the rest are missing. + // The order of entries reported by entries() is undeterministic, so entries + // have to be sorted before comparison. + var wantUnsortedEntries []NeighborEntry + for i := store.size() - neighborCacheSize; i < store.size(); i++ { + entry, ok := store.entry(i) + if !ok { + t.Errorf("store.entry(%d) not found", i) + } + wantEntry := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: entry.LinkAddr, + State: Reachable, + } + wantUnsortedEntries = append(wantUnsortedEntries, wantEntry) + } + + if diff := cmp.Diff(neigh.entries(), wantUnsortedEntries, entryDiffOptsWithSort()...); diff != "" { + t.Errorf("neighbor entries mismatch (-got, +want):\n%s", diff) + } +} + +func TestNeighborCacheReplace(t *testing.T) { + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + // Add an entry + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + clock.advance(typicalLatency) + select { + case <-doneCh: + default: + t.Fatalf("expected notification from done channel returned by neigh.entry(%s, %s, _, nil)", entry.Addr, entry.LocalAddr) + } + + // Verify the entry exists + e, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != nil { + t.Errorf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) + } + if doneCh != nil { + t.Errorf("unexpected done channel from neigh.entry(%s, %s, _, nil): %v", entry.Addr, entry.LocalAddr, doneCh) + } + if t.Failed() { + t.FailNow() + } + want := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: entry.LinkAddr, + State: Reachable, + } + if diff := cmp.Diff(e, want, entryDiffOpts()...); diff != "" { + t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", entry.Addr, entry.LinkAddr, diff) + } + + // Notify of a link address change + var updatedLinkAddr tcpip.LinkAddress + { + entry, ok := store.entry(1) + if !ok { + t.Fatalf("store.entry(1) not found") + } + updatedLinkAddr = entry.LinkAddr + } + store.set(0, updatedLinkAddr) + neigh.HandleConfirmation(entry.Addr, updatedLinkAddr, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + + // Requesting the entry again should start address resolution + { + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + clock.advance(config.DelayFirstProbeTime + typicalLatency) + select { + case <-doneCh: + default: + t.Fatalf("expected notification from done channel returned by neigh.entry(%s, %s, _, nil)", entry.Addr, entry.LocalAddr) + } + } + + // Verify the entry's new link address + { + e, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + clock.advance(typicalLatency) + if err != nil { + t.Errorf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) + } + want = NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: updatedLinkAddr, + State: Reachable, + } + if diff := cmp.Diff(e, want, entryDiffOpts()...); diff != "" { + t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", entry.Addr, entry.LocalAddr, diff) + } + } +} + +func TestNeighborCacheResolutionFailed(t *testing.T) { + config := DefaultNUDConfigurations() + + nudDisp := testNUDDispatcher{} + clock := newFakeClock() + neigh := newTestNeighborCache(&nudDisp, config, clock) + store := newTestEntryStore() + + var requestCount uint32 + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + onLinkAddressRequest: func() { + atomic.AddUint32(&requestCount, 1) + }, + } + + // First, sanity check that resolution is working + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + clock.advance(typicalLatency) + got, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != nil { + t.Fatalf("unexpected error from neigh.entry(%s, %s, _, nil): %s", entry.Addr, entry.LocalAddr, err) + } + want := NeighborEntry{ + Addr: entry.Addr, + LocalAddr: entry.LocalAddr, + LinkAddr: entry.LinkAddr, + State: Reachable, + } + if diff := cmp.Diff(got, want, entryDiffOpts()...); diff != "" { + t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", entry.Addr, entry.LocalAddr, diff) + } + + // Verify that address resolution for an unknown address returns ErrNoLinkAddress + before := atomic.LoadUint32(&requestCount) + + entry.Addr += "2" + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + waitFor := config.DelayFirstProbeTime + typicalLatency*time.Duration(config.MaxMulticastProbes) + clock.advance(waitFor) + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != tcpip.ErrNoLinkAddress { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrNoLinkAddress) + } + + maxAttempts := neigh.config().MaxUnicastProbes + if got, want := atomic.LoadUint32(&requestCount)-before, maxAttempts; got != want { + t.Errorf("got link address request count = %d, want = %d", got, want) + } +} + +// TestNeighborCacheResolutionTimeout simulates sending MaxMulticastProbes +// probes and not retrieving a confirmation before the duration defined by +// MaxMulticastProbes * RetransmitTimer. +func TestNeighborCacheResolutionTimeout(t *testing.T) { + config := DefaultNUDConfigurations() + config.RetransmitTimer = time.Millisecond // small enough to cause timeout + + clock := newFakeClock() + neigh := newTestNeighborCache(nil, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: time.Minute, // large enough to cause timeout + } + + entry, ok := store.entry(0) + if !ok { + t.Fatalf("store.entry(0) not found") + } + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != tcpip.ErrWouldBlock { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + waitFor := config.RetransmitTimer * time.Duration(config.MaxMulticastProbes) + clock.advance(waitFor) + if _, _, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil); err != tcpip.ErrNoLinkAddress { + t.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrNoLinkAddress) + } +} + +// TestNeighborCacheStaticResolution checks that static link addresses are +// resolved immediately and don't send resolution requests. +func TestNeighborCacheStaticResolution(t *testing.T) { + config := DefaultNUDConfigurations() + clock := newFakeClock() + neigh := newTestNeighborCache(nil, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: typicalLatency, + } + + got, _, err := neigh.entry(testEntryBroadcastAddr, testEntryLocalAddr, linkRes, nil) + if err != nil { + t.Fatalf("unexpected error from neigh.entry(%s, %s, _, nil): %s", testEntryBroadcastAddr, testEntryLocalAddr, err) + } + want := NeighborEntry{ + Addr: testEntryBroadcastAddr, + LocalAddr: testEntryLocalAddr, + LinkAddr: testEntryBroadcastLinkAddr, + State: Static, + } + if diff := cmp.Diff(got, want, entryDiffOpts()...); diff != "" { + t.Errorf("neigh.entry(%s, %s, _, nil) mismatch (-got, +want):\n%s", testEntryBroadcastAddr, testEntryLocalAddr, diff) + } +} + +func BenchmarkCacheClear(b *testing.B) { + b.StopTimer() + config := DefaultNUDConfigurations() + clock := &tcpip.StdClock{} + neigh := newTestNeighborCache(nil, config, clock) + store := newTestEntryStore() + linkRes := &testNeighborResolver{ + clock: clock, + neigh: neigh, + entries: store, + delay: 0, + } + + // Clear for every possible size of the cache + for cacheSize := 0; cacheSize < neighborCacheSize; cacheSize++ { + // Fill the neighbor cache to capacity. + for i := 0; i < cacheSize; i++ { + entry, ok := store.entry(i) + if !ok { + b.Fatalf("store.entry(%d) not found", i) + } + _, doneCh, err := neigh.entry(entry.Addr, entry.LocalAddr, linkRes, nil) + if err != tcpip.ErrWouldBlock { + b.Fatalf("got neigh.entry(%s, %s, _, nil) = %v, want = %s", entry.Addr, entry.LocalAddr, err, tcpip.ErrWouldBlock) + } + if doneCh != nil { + <-doneCh + } + } + + b.StartTimer() + neigh.clear() + b.StopTimer() + } +} diff --git a/pkg/tcpip/stack/neighbor_entry.go b/pkg/tcpip/stack/neighbor_entry.go new file mode 100644 index 000000000..0068cacb8 --- /dev/null +++ b/pkg/tcpip/stack/neighbor_entry.go @@ -0,0 +1,482 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "fmt" + "sync" + "time" + + "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/tcpip" +) + +// NeighborEntry describes a neighboring device in the local network. +type NeighborEntry struct { + Addr tcpip.Address + LocalAddr tcpip.Address + LinkAddr tcpip.LinkAddress + State NeighborState + UpdatedAt time.Time +} + +// NeighborState defines the state of a NeighborEntry within the Neighbor +// Unreachability Detection state machine, as per RFC 4861 section 7.3.2. +type NeighborState uint8 + +const ( + // Unknown means reachability has not been verified yet. This is the initial + // state of entries that have been created automatically by the Neighbor + // Unreachability Detection state machine. + Unknown NeighborState = iota + // Incomplete means that there is an outstanding request to resolve the + // address. + Incomplete + // Reachable means the path to the neighbor is functioning properly for both + // receive and transmit paths. + Reachable + // Stale means reachability to the neighbor is unknown, but packets are still + // able to be transmitted to the possibly stale link address. + Stale + // Delay means reachability to the neighbor is unknown and pending + // confirmation from an upper-level protocol like TCP, but packets are still + // able to be transmitted to the possibly stale link address. + Delay + // Probe means a reachability confirmation is actively being sought by + // periodically retransmitting reachability probes until a reachability + // confirmation is received, or until the max amount of probes has been sent. + Probe + // Static describes entries that have been explicitly added by the user. They + // do not expire and are not deleted until explicitly removed. + Static + // Failed means traffic should not be sent to this neighbor since attempts of + // reachability have returned inconclusive. + Failed +) + +// neighborEntry implements a neighbor entry's individual node behavior, as per +// RFC 4861 section 7.3.3. Neighbor Unreachability Detection operates in +// parallel with the sending of packets to a neighbor, necessitating the +// entry's lock to be acquired for all operations. +type neighborEntry struct { + neighborEntryEntry + + nic *NIC + protocol tcpip.NetworkProtocolNumber + + // linkRes provides the functionality to send reachability probes, used in + // Neighbor Unreachability Detection. + linkRes LinkAddressResolver + + // nudState points to the Neighbor Unreachability Detection configuration. + nudState *NUDState + + // mu protects the fields below. + mu sync.RWMutex + + neigh NeighborEntry + + // wakers is a set of waiters for address resolution result. Anytime state + // transitions out of incomplete these waiters are notified. It is nil iff + // address resolution is ongoing and no clients are waiting for the result. + wakers map[*sleep.Waker]struct{} + + // done is used to allow callers to wait on address resolution. It is nil + // iff nudState is not Reachable and address resolution is not yet in + // progress. + done chan struct{} + + isRouter bool + job *tcpip.Job +} + +// newNeighborEntry creates a neighbor cache entry starting at the default +// state, Unknown. Transition out of Unknown by calling either +// `handlePacketQueuedLocked` or `handleProbeLocked` on the newly created +// neighborEntry. +func newNeighborEntry(nic *NIC, remoteAddr tcpip.Address, localAddr tcpip.Address, nudState *NUDState, linkRes LinkAddressResolver) *neighborEntry { + return &neighborEntry{ + nic: nic, + linkRes: linkRes, + nudState: nudState, + neigh: NeighborEntry{ + Addr: remoteAddr, + LocalAddr: localAddr, + State: Unknown, + }, + } +} + +// newStaticNeighborEntry creates a neighbor cache entry starting at the Static +// state. The entry can only transition out of Static by directly calling +// `setStateLocked`. +func newStaticNeighborEntry(nic *NIC, addr tcpip.Address, linkAddr tcpip.LinkAddress, state *NUDState) *neighborEntry { + if nic.stack.nudDisp != nil { + nic.stack.nudDisp.OnNeighborAdded(nic.id, addr, linkAddr, Static, time.Now()) + } + return &neighborEntry{ + nic: nic, + nudState: state, + neigh: NeighborEntry{ + Addr: addr, + LinkAddr: linkAddr, + State: Static, + UpdatedAt: time.Now(), + }, + } +} + +// addWaker adds w to the list of wakers waiting for address resolution. +// Assumes the entry has already been appropriately locked. +func (e *neighborEntry) addWakerLocked(w *sleep.Waker) { + if w == nil { + return + } + if e.wakers == nil { + e.wakers = make(map[*sleep.Waker]struct{}) + } + e.wakers[w] = struct{}{} +} + +// notifyWakersLocked notifies those waiting for address resolution, whether it +// succeeded or failed. Assumes the entry has already been appropriately locked. +func (e *neighborEntry) notifyWakersLocked() { + for w := range e.wakers { + w.Assert() + } + e.wakers = nil + if ch := e.done; ch != nil { + close(ch) + e.done = nil + } +} + +// dispatchAddEventLocked signals to stack's NUD Dispatcher that the entry has +// been added. +func (e *neighborEntry) dispatchAddEventLocked(nextState NeighborState) { + if nudDisp := e.nic.stack.nudDisp; nudDisp != nil { + nudDisp.OnNeighborAdded(e.nic.id, e.neigh.Addr, e.neigh.LinkAddr, nextState, time.Now()) + } +} + +// dispatchChangeEventLocked signals to stack's NUD Dispatcher that the entry +// has changed state or link-layer address. +func (e *neighborEntry) dispatchChangeEventLocked(nextState NeighborState) { + if nudDisp := e.nic.stack.nudDisp; nudDisp != nil { + nudDisp.OnNeighborChanged(e.nic.id, e.neigh.Addr, e.neigh.LinkAddr, nextState, time.Now()) + } +} + +// dispatchRemoveEventLocked signals to stack's NUD Dispatcher that the entry +// has been removed. +func (e *neighborEntry) dispatchRemoveEventLocked() { + if nudDisp := e.nic.stack.nudDisp; nudDisp != nil { + nudDisp.OnNeighborRemoved(e.nic.id, e.neigh.Addr, e.neigh.LinkAddr, e.neigh.State, time.Now()) + } +} + +// setStateLocked transitions the entry to the specified state immediately. +// +// Follows the logic defined in RFC 4861 section 7.3.3. +// +// e.mu MUST be locked. +func (e *neighborEntry) setStateLocked(next NeighborState) { + // Cancel the previously scheduled action, if there is one. Entries in + // Unknown, Stale, or Static state do not have scheduled actions. + if timer := e.job; timer != nil { + timer.Cancel() + } + + prev := e.neigh.State + e.neigh.State = next + e.neigh.UpdatedAt = time.Now() + config := e.nudState.Config() + + switch next { + case Incomplete: + var retryCounter uint32 + var sendMulticastProbe func() + + sendMulticastProbe = func() { + if retryCounter == config.MaxMulticastProbes { + // "If no Neighbor Advertisement is received after + // MAX_MULTICAST_SOLICIT solicitations, address resolution has failed. + // The sender MUST return ICMP destination unreachable indications with + // code 3 (Address Unreachable) for each packet queued awaiting address + // resolution." - RFC 4861 section 7.2.2 + // + // There is no need to send an ICMP destination unreachable indication + // since the failure to resolve the address is expected to only occur + // on this node. Thus, redirecting traffic is currently not supported. + // + // "If the error occurs on a node other than the node originating the + // packet, an ICMP error message is generated. If the error occurs on + // the originating node, an implementation is not required to actually + // create and send an ICMP error packet to the source, as long as the + // upper-layer sender is notified through an appropriate mechanism + // (e.g. return value from a procedure call). Note, however, that an + // implementation may find it convenient in some cases to return errors + // to the sender by taking the offending packet, generating an ICMP + // error message, and then delivering it (locally) through the generic + // error-handling routines.' - RFC 4861 section 2.1 + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, e.neigh.LocalAddr, "", e.nic.linkEP); err != nil { + // There is no need to log the error here; the NUD implementation may + // assume a working link. A valid link should be the responsibility of + // the NIC/stack.LinkEndpoint. + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + retryCounter++ + e.job = e.nic.stack.newJob(&e.mu, sendMulticastProbe) + e.job.Schedule(config.RetransmitTimer) + } + + sendMulticastProbe() + + case Reachable: + e.job = e.nic.stack.newJob(&e.mu, func() { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + }) + e.job.Schedule(e.nudState.ReachableTime()) + + case Delay: + e.job = e.nic.stack.newJob(&e.mu, func() { + e.dispatchChangeEventLocked(Probe) + e.setStateLocked(Probe) + }) + e.job.Schedule(config.DelayFirstProbeTime) + + case Probe: + var retryCounter uint32 + var sendUnicastProbe func() + + sendUnicastProbe = func() { + if retryCounter == config.MaxUnicastProbes { + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + if err := e.linkRes.LinkAddressRequest(e.neigh.Addr, e.neigh.LocalAddr, e.neigh.LinkAddr, e.nic.linkEP); err != nil { + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + retryCounter++ + if retryCounter == config.MaxUnicastProbes { + e.dispatchRemoveEventLocked() + e.setStateLocked(Failed) + return + } + + e.job = e.nic.stack.newJob(&e.mu, sendUnicastProbe) + e.job.Schedule(config.RetransmitTimer) + } + + sendUnicastProbe() + + case Failed: + e.notifyWakersLocked() + e.job = e.nic.stack.newJob(&e.mu, func() { + e.nic.neigh.removeEntryLocked(e) + }) + e.job.Schedule(config.UnreachableTime) + + case Unknown, Stale, Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid state transition from %q to %q", prev, next)) + } +} + +// handlePacketQueuedLocked advances the state machine according to a packet +// being queued for outgoing transmission. +// +// Follows the logic defined in RFC 4861 section 7.3.3. +func (e *neighborEntry) handlePacketQueuedLocked() { + switch e.neigh.State { + case Unknown: + e.dispatchAddEventLocked(Incomplete) + e.setStateLocked(Incomplete) + + case Stale: + e.dispatchChangeEventLocked(Delay) + e.setStateLocked(Delay) + + case Incomplete, Reachable, Delay, Probe, Static, Failed: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} + +// handleProbeLocked processes an incoming neighbor probe (e.g. ARP request or +// Neighbor Solicitation for ARP or NDP, respectively). +// +// Follows the logic defined in RFC 4861 section 7.2.3. +func (e *neighborEntry) handleProbeLocked(remoteLinkAddr tcpip.LinkAddress) { + // Probes MUST be silently discarded if the target address is tentative, does + // not exist, or not bound to the NIC as per RFC 4861 section 7.2.3. These + // checks MUST be done by the NetworkEndpoint. + + switch e.neigh.State { + case Unknown, Incomplete, Failed: + e.neigh.LinkAddr = remoteLinkAddr + e.dispatchAddEventLocked(Stale) + e.setStateLocked(Stale) + e.notifyWakersLocked() + + case Reachable, Delay, Probe: + if e.neigh.LinkAddr != remoteLinkAddr { + e.neigh.LinkAddr = remoteLinkAddr + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } + + case Stale: + if e.neigh.LinkAddr != remoteLinkAddr { + e.neigh.LinkAddr = remoteLinkAddr + e.dispatchChangeEventLocked(Stale) + } + + case Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} + +// handleConfirmationLocked processes an incoming neighbor confirmation +// (e.g. ARP reply or Neighbor Advertisement for ARP or NDP, respectively). +// +// Follows the state machine defined by RFC 4861 section 7.2.5. +// +// TODO(gvisor.dev/issue/2277): To protect against ARP poisoning and other +// attacks against NDP functions, Secure Neighbor Discovery (SEND) Protocol +// should be deployed where preventing access to the broadcast segment might +// not be possible. SEND uses RSA key pairs to produce Cryptographically +// Generated Addresses (CGA), as defined in RFC 3972. This ensures that the +// claimed source of an NDP message is the owner of the claimed address. +func (e *neighborEntry) handleConfirmationLocked(linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) { + switch e.neigh.State { + case Incomplete: + if len(linkAddr) == 0 { + // "If the link layer has addresses and no Target Link-Layer Address + // option is included, the receiving node SHOULD silently discard the + // received advertisement." - RFC 4861 section 7.2.5 + break + } + + e.neigh.LinkAddr = linkAddr + if flags.Solicited { + e.dispatchChangeEventLocked(Reachable) + e.setStateLocked(Reachable) + } else { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } + e.isRouter = flags.IsRouter + e.notifyWakersLocked() + + // "Note that the Override flag is ignored if the entry is in the + // INCOMPLETE state." - RFC 4861 section 7.2.5 + + case Reachable, Stale, Delay, Probe: + sameLinkAddr := e.neigh.LinkAddr == linkAddr + + if !sameLinkAddr { + if !flags.Override { + if e.neigh.State == Reachable { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } + break + } + + e.neigh.LinkAddr = linkAddr + + if !flags.Solicited { + if e.neigh.State != Stale { + e.dispatchChangeEventLocked(Stale) + e.setStateLocked(Stale) + } else { + // Notify the LinkAddr change, even though NUD state hasn't changed. + e.dispatchChangeEventLocked(e.neigh.State) + } + break + } + } + + if flags.Solicited && (flags.Override || sameLinkAddr) { + if e.neigh.State != Reachable { + e.dispatchChangeEventLocked(Reachable) + } + // Set state to Reachable again to refresh timers. + e.setStateLocked(Reachable) + e.notifyWakersLocked() + } + + if e.isRouter && !flags.IsRouter { + // "In those cases where the IsRouter flag changes from TRUE to FALSE as + // a result of this update, the node MUST remove that router from the + // Default Router List and update the Destination Cache entries for all + // destinations using that neighbor as a router as specified in Section + // 7.3.3. This is needed to detect when a node that is used as a router + // stops forwarding packets due to being configured as a host." + // - RFC 4861 section 7.2.5 + e.nic.mu.Lock() + e.nic.mu.ndp.invalidateDefaultRouter(e.neigh.Addr) + e.nic.mu.Unlock() + } + e.isRouter = flags.IsRouter + + case Unknown, Failed, Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} + +// handleUpperLevelConfirmationLocked processes an incoming upper-level protocol +// (e.g. TCP acknowledgements) reachability confirmation. +func (e *neighborEntry) handleUpperLevelConfirmationLocked() { + switch e.neigh.State { + case Reachable, Stale, Delay, Probe: + if e.neigh.State != Reachable { + e.dispatchChangeEventLocked(Reachable) + // Set state to Reachable again to refresh timers. + } + e.setStateLocked(Reachable) + + case Unknown, Incomplete, Failed, Static: + // Do nothing + + default: + panic(fmt.Sprintf("Invalid cache entry state: %s", e.neigh.State)) + } +} diff --git a/pkg/tcpip/stack/neighbor_entry_test.go b/pkg/tcpip/stack/neighbor_entry_test.go new file mode 100644 index 000000000..08c9ccd25 --- /dev/null +++ b/pkg/tcpip/stack/neighbor_entry_test.go @@ -0,0 +1,2770 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "fmt" + "math" + "math/rand" + "strings" + "sync" + "testing" + "time" + + "github.com/google/go-cmp/cmp" + "github.com/google/go-cmp/cmp/cmpopts" + "gvisor.dev/gvisor/pkg/sleep" + "gvisor.dev/gvisor/pkg/tcpip" +) + +const ( + entryTestNetNumber tcpip.NetworkProtocolNumber = math.MaxUint32 + + entryTestNICID tcpip.NICID = 1 + entryTestAddr1 = tcpip.Address("\x00\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01") + entryTestAddr2 = tcpip.Address("\x00\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02") + + entryTestLinkAddr1 = tcpip.LinkAddress("\x0a\x00\x00\x00\x00\x01") + entryTestLinkAddr2 = tcpip.LinkAddress("\x0a\x00\x00\x00\x00\x02") + + // entryTestNetDefaultMTU is the MTU, in bytes, used throughout the tests, + // except where another value is explicitly used. It is chosen to match the + // MTU of loopback interfaces on Linux systems. + entryTestNetDefaultMTU = 65536 +) + +// eventDiffOpts are the options passed to cmp.Diff to compare entry events. +// The UpdatedAt field is ignored due to a lack of a deterministic method to +// predict the time that an event will be dispatched. +func eventDiffOpts() []cmp.Option { + return []cmp.Option{ + cmpopts.IgnoreFields(testEntryEventInfo{}, "UpdatedAt"), + } +} + +// eventDiffOptsWithSort is like eventDiffOpts but also includes an option to +// sort slices of events for cases where ordering must be ignored. +func eventDiffOptsWithSort() []cmp.Option { + return []cmp.Option{ + cmpopts.IgnoreFields(testEntryEventInfo{}, "UpdatedAt"), + cmpopts.SortSlices(func(a, b testEntryEventInfo) bool { + return strings.Compare(string(a.Addr), string(b.Addr)) < 0 + }), + } +} + +// The following unit tests exercise every state transition and verify its +// behavior with RFC 4681. +// +// | From | To | Cause | Action | Event | +// | ========== | ========== | ========================================== | =============== | ======= | +// | Unknown | Unknown | Confirmation w/ unknown address | | Added | +// | Unknown | Incomplete | Packet queued to unknown address | Send probe | Added | +// | Unknown | Stale | Probe w/ unknown address | | Added | +// | Incomplete | Incomplete | Retransmit timer expired | Send probe | Changed | +// | Incomplete | Reachable | Solicited confirmation | Notify wakers | Changed | +// | Incomplete | Stale | Unsolicited confirmation | Notify wakers | Changed | +// | Incomplete | Failed | Max probes sent without reply | Notify wakers | Removed | +// | Reachable | Reachable | Confirmation w/ different isRouter flag | Update IsRouter | | +// | Reachable | Stale | Reachable timer expired | | Changed | +// | Reachable | Stale | Probe or confirmation w/ different address | | Changed | +// | Stale | Reachable | Solicited override confirmation | Update LinkAddr | Changed | +// | Stale | Stale | Override confirmation | Update LinkAddr | Changed | +// | Stale | Stale | Probe w/ different address | Update LinkAddr | Changed | +// | Stale | Delay | Packet sent | | Changed | +// | Delay | Reachable | Upper-layer confirmation | | Changed | +// | Delay | Reachable | Solicited override confirmation | Update LinkAddr | Changed | +// | Delay | Stale | Probe or confirmation w/ different address | | Changed | +// | Delay | Probe | Delay timer expired | Send probe | Changed | +// | Probe | Reachable | Solicited override confirmation | Update LinkAddr | Changed | +// | Probe | Reachable | Solicited confirmation w/ same address | Notify wakers | Changed | +// | Probe | Stale | Probe or confirmation w/ different address | | Changed | +// | Probe | Probe | Retransmit timer expired | Send probe | Changed | +// | Probe | Failed | Max probes sent without reply | Notify wakers | Removed | +// | Failed | | Unreachability timer expired | Delete entry | | + +type testEntryEventType uint8 + +const ( + entryTestAdded testEntryEventType = iota + entryTestChanged + entryTestRemoved +) + +func (t testEntryEventType) String() string { + switch t { + case entryTestAdded: + return "add" + case entryTestChanged: + return "change" + case entryTestRemoved: + return "remove" + default: + return fmt.Sprintf("unknown (%d)", t) + } +} + +// Fields are exported for use with cmp.Diff. +type testEntryEventInfo struct { + EventType testEntryEventType + NICID tcpip.NICID + Addr tcpip.Address + LinkAddr tcpip.LinkAddress + State NeighborState + UpdatedAt time.Time +} + +func (e testEntryEventInfo) String() string { + return fmt.Sprintf("%s event for NIC #%d, addr=%q, linkAddr=%q, state=%q", e.EventType, e.NICID, e.Addr, e.LinkAddr, e.State) +} + +// testNUDDispatcher implements NUDDispatcher to validate the dispatching of +// events upon certain NUD state machine events. +type testNUDDispatcher struct { + mu sync.Mutex + events []testEntryEventInfo +} + +var _ NUDDispatcher = (*testNUDDispatcher)(nil) + +func (d *testNUDDispatcher) queueEvent(e testEntryEventInfo) { + d.mu.Lock() + defer d.mu.Unlock() + d.events = append(d.events, e) +} + +func (d *testNUDDispatcher) OnNeighborAdded(nicID tcpip.NICID, addr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) { + d.queueEvent(testEntryEventInfo{ + EventType: entryTestAdded, + NICID: nicID, + Addr: addr, + LinkAddr: linkAddr, + State: state, + UpdatedAt: updatedAt, + }) +} + +func (d *testNUDDispatcher) OnNeighborChanged(nicID tcpip.NICID, addr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) { + d.queueEvent(testEntryEventInfo{ + EventType: entryTestChanged, + NICID: nicID, + Addr: addr, + LinkAddr: linkAddr, + State: state, + UpdatedAt: updatedAt, + }) +} + +func (d *testNUDDispatcher) OnNeighborRemoved(nicID tcpip.NICID, addr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) { + d.queueEvent(testEntryEventInfo{ + EventType: entryTestRemoved, + NICID: nicID, + Addr: addr, + LinkAddr: linkAddr, + State: state, + UpdatedAt: updatedAt, + }) +} + +type entryTestLinkResolver struct { + mu sync.Mutex + probes []entryTestProbeInfo +} + +var _ LinkAddressResolver = (*entryTestLinkResolver)(nil) + +type entryTestProbeInfo struct { + RemoteAddress tcpip.Address + RemoteLinkAddress tcpip.LinkAddress + LocalAddress tcpip.Address +} + +func (p entryTestProbeInfo) String() string { + return fmt.Sprintf("probe with RemoteAddress=%q, RemoteLinkAddress=%q, LocalAddress=%q", p.RemoteAddress, p.RemoteLinkAddress, p.LocalAddress) +} + +// LinkAddressRequest sends a request for the LinkAddress of addr. Broadcasts +// to the local network if linkAddr is the zero value. +func (r *entryTestLinkResolver) LinkAddressRequest(addr, localAddr tcpip.Address, linkAddr tcpip.LinkAddress, linkEP LinkEndpoint) *tcpip.Error { + p := entryTestProbeInfo{ + RemoteAddress: addr, + RemoteLinkAddress: linkAddr, + LocalAddress: localAddr, + } + r.mu.Lock() + defer r.mu.Unlock() + r.probes = append(r.probes, p) + return nil +} + +// ResolveStaticAddress attempts to resolve address without sending requests. +// It either resolves the name immediately or returns the empty LinkAddress. +func (r *entryTestLinkResolver) ResolveStaticAddress(addr tcpip.Address) (tcpip.LinkAddress, bool) { + return "", false +} + +// LinkAddressProtocol returns the network protocol of the addresses this +// resolver can resolve. +func (r *entryTestLinkResolver) LinkAddressProtocol() tcpip.NetworkProtocolNumber { + return entryTestNetNumber +} + +func entryTestSetup(c NUDConfigurations) (*neighborEntry, *testNUDDispatcher, *entryTestLinkResolver, *fakeClock) { + clock := newFakeClock() + disp := testNUDDispatcher{} + nic := NIC{ + id: entryTestNICID, + linkEP: nil, // entryTestLinkResolver doesn't use a LinkEndpoint + stack: &Stack{ + clock: clock, + nudDisp: &disp, + }, + } + + rng := rand.New(rand.NewSource(time.Now().UnixNano())) + nudState := NewNUDState(c, rng) + linkRes := entryTestLinkResolver{} + entry := newNeighborEntry(&nic, entryTestAddr1, entryTestAddr2, nudState, &linkRes) + + // Stub out ndpState to verify modification of default routers. + nic.mu.ndp = ndpState{ + nic: &nic, + defaultRouters: make(map[tcpip.Address]defaultRouterState), + } + + // Stub out the neighbor cache to verify deletion from the cache. + nic.neigh = &neighborCache{ + nic: &nic, + state: nudState, + cache: make(map[tcpip.Address]*neighborEntry, neighborCacheSize), + } + nic.neigh.cache[entryTestAddr1] = entry + + return entry, &disp, &linkRes, clock +} + +// TestEntryInitiallyUnknown verifies that the state of a newly created +// neighborEntry is Unknown. +func TestEntryInitiallyUnknown(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + if got, want := e.neigh.State, Unknown; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + clock.advance(c.RetransmitTimer) + + // No probes should have been sent. + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, []entryTestProbeInfo(nil)) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + // No events should have been dispatched. + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryUnknownToUnknownWhenConfirmationWithUnknownAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Unknown; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + clock.advance(time.Hour) + + // No probes should have been sent. + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, []entryTestProbeInfo(nil)) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + // No events should have been dispatched. + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, []testEntryEventInfo(nil)); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryUnknownToIncomplete(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Incomplete; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + } + { + nudDisp.mu.Lock() + diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...) + nudDisp.mu.Unlock() + if diff != "" { + t.Fatalf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + } +} + +func TestEntryUnknownToStale(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handleProbeLocked(entryTestLinkAddr1) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + // No probes should have been sent. + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, []entryTestProbeInfo(nil)) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryIncompleteToIncompleteDoesNotChangeUpdatedAt(t *testing.T) { + c := DefaultNUDConfigurations() + c.MaxMulticastProbes = 3 + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Incomplete; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + updatedAt := e.neigh.UpdatedAt + e.mu.Unlock() + + clock.advance(c.RetransmitTimer) + + // UpdatedAt should remain the same during address resolution. + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.probes = nil + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + e.mu.Lock() + if got, want := e.neigh.UpdatedAt, updatedAt; got != want { + t.Errorf("got e.neigh.UpdatedAt = %q, want = %q", got, want) + } + e.mu.Unlock() + + clock.advance(c.RetransmitTimer) + + // UpdatedAt should change after failing address resolution. Timing out after + // sending the last probe transitions the entry to Failed. + { + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + } + + clock.advance(c.RetransmitTimer) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestRemoved, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, notWant := e.neigh.UpdatedAt, updatedAt; got == notWant { + t.Errorf("expected e.neigh.UpdatedAt to change, got = %q", got) + } + e.mu.Unlock() +} + +func TestEntryIncompleteToReachable(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Incomplete; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +// TestEntryAddsAndClearsWakers verifies that wakers are added when +// addWakerLocked is called and cleared when address resolution finishes. In +// this case, address resolution will finish when transitioning from Incomplete +// to Reachable. +func TestEntryAddsAndClearsWakers(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + w := sleep.Waker{} + s := sleep.Sleeper{} + s.AddWaker(&w, 123) + defer s.Done() + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got := e.wakers; got != nil { + t.Errorf("got e.wakers = %v, want = nil", got) + } + e.addWakerLocked(&w) + if got, want := w.IsAsserted(), false; got != want { + t.Errorf("waker.IsAsserted() = %t, want = %t", got, want) + } + if e.wakers == nil { + t.Error("expected e.wakers to be non-nil") + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if e.wakers != nil { + t.Errorf("got e.wakers = %v, want = nil", e.wakers) + } + if got, want := w.IsAsserted(), true; got != want { + t.Errorf("waker.IsAsserted() = %t, want = %t", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryIncompleteToReachableWithRouterFlag(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Incomplete; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: true, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.isRouter, true; got != want { + t.Errorf("got e.isRouter = %t, want = %t", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + if diff := cmp.Diff(linkRes.probes, wantProbes); diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + linkRes.mu.Unlock() + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryIncompleteToStale(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Incomplete; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryIncompleteToFailed(t *testing.T) { + c := DefaultNUDConfigurations() + c.MaxMulticastProbes = 3 + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Incomplete; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + waitFor := c.RetransmitTimer * time.Duration(c.MaxMulticastProbes) + clock.advance(waitFor) + + wantProbes := []entryTestProbeInfo{ + // The Incomplete-to-Incomplete state transition is tested here by + // verifying that 3 reachability probes were sent. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestRemoved, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Failed; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +type testLocker struct{} + +var _ sync.Locker = (*testLocker)(nil) + +func (*testLocker) Lock() {} +func (*testLocker) Unlock() {} + +func TestEntryStaysReachableWhenConfirmationWithRouterFlag(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: true, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.isRouter, true; got != want { + t.Errorf("got e.isRouter = %t, want = %t", got, want) + } + e.nic.mu.ndp.defaultRouters[entryTestAddr1] = defaultRouterState{ + invalidationJob: e.nic.stack.newJob(&testLocker{}, func() {}), + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.isRouter, false; got != want { + t.Errorf("got e.isRouter = %t, want = %t", got, want) + } + if _, ok := e.nic.mu.ndp.defaultRouters[entryTestAddr1]; ok { + t.Errorf("unexpected defaultRouter for %s", entryTestAddr1) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryStaysReachableWhenProbeWithSameAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleProbeLocked(entryTestLinkAddr1) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr1; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryReachableToStaleWhenTimeout(t *testing.T) { + c := DefaultNUDConfigurations() + // Eliminate random factors from ReachableTime computation so the transition + // from Stale to Reachable will only take BaseReachableTime duration. + c.MinRandomFactor = 1 + c.MaxRandomFactor = 1 + + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + clock.advance(c.BaseReachableTime) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryReachableToStaleWhenProbeWithDifferentAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleProbeLocked(entryTestLinkAddr2) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryReachableToStaleWhenConfirmationWithDifferentAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryReachableToStaleWhenConfirmationWithDifferentAddressAndOverride(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryStaysStaleWhenProbeWithSameAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleProbeLocked(entryTestLinkAddr1) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr1; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryStaleToReachableWhenSolicitedOverrideConfirmation(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: true, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr2; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Reachable, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryStaleToStaleWhenOverrideConfirmation(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr2; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryStaleToStaleWhenProbeUpdateAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleProbeLocked(entryTestLinkAddr2) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr2; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryStaleToDelay(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryDelayToReachableWhenUpperLevelConfirmation(t *testing.T) { + c := DefaultNUDConfigurations() + // Eliminate random factors from ReachableTime computation so the transition + // from Stale to Reachable will only take BaseReachableTime duration. + c.MinRandomFactor = 1 + c.MaxRandomFactor = 1 + + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleUpperLevelConfirmationLocked() + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + clock.advance(c.BaseReachableTime) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryDelayToReachableWhenSolicitedOverrideConfirmation(t *testing.T) { + c := DefaultNUDConfigurations() + c.MaxMulticastProbes = 1 + // Eliminate random factors from ReachableTime computation so the transition + // from Stale to Reachable will only take BaseReachableTime duration. + c.MinRandomFactor = 1 + c.MaxRandomFactor = 1 + + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: true, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr2; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + clock.advance(c.BaseReachableTime) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryStaysDelayWhenOverrideConfirmationWithSameAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr1; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryDelayToStaleWhenProbeWithDifferentAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleProbeLocked(entryTestLinkAddr2) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryDelayToStaleWhenConfirmationWithDifferentAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, _ := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantProbes := []entryTestProbeInfo{ + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryDelayToProbe(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + if got, want := e.neigh.State, Delay; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + clock.advance(c.DelayFirstProbeTime) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The second probe is caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryProbeToStaleWhenProbeWithDifferentAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + clock.advance(c.DelayFirstProbeTime) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The second probe is caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + e.mu.Lock() + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleProbeLocked(entryTestLinkAddr2) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryProbeToStaleWhenConfirmationWithDifferentAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + clock.advance(c.DelayFirstProbeTime) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The second probe is caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + e.mu.Lock() + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Stale; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryStaysProbeWhenOverrideConfirmationWithSameAddress(t *testing.T) { + c := DefaultNUDConfigurations() + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + clock.advance(c.DelayFirstProbeTime) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The second probe is caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + e.mu.Lock() + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr1; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryProbeToReachableWhenSolicitedOverrideConfirmation(t *testing.T) { + c := DefaultNUDConfigurations() + // Eliminate random factors from ReachableTime computation so the transition + // from Stale to Reachable will only take BaseReachableTime duration. + c.MinRandomFactor = 1 + c.MaxRandomFactor = 1 + + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + clock.advance(c.DelayFirstProbeTime) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The second probe is caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + e.mu.Lock() + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr2, ReachabilityConfirmationFlags{ + Solicited: true, + Override: true, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + if got, want := e.neigh.LinkAddr, entryTestLinkAddr2; got != want { + t.Errorf("got e.neigh.LinkAddr = %q, want = %q", got, want) + } + e.mu.Unlock() + + clock.advance(c.BaseReachableTime) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr2, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryProbeToReachableWhenSolicitedConfirmationWithSameAddress(t *testing.T) { + c := DefaultNUDConfigurations() + // Eliminate random factors from ReachableTime computation so the transition + // from Stale to Reachable will only take BaseReachableTime duration. + c.MinRandomFactor = 1 + c.MaxRandomFactor = 1 + + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + clock.advance(c.DelayFirstProbeTime) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The second probe is caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + e.mu.Lock() + if got, want := e.neigh.State, Probe; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: true, + Override: false, + IsRouter: false, + }) + if got, want := e.neigh.State, Reachable; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() + + clock.advance(c.BaseReachableTime) + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Reachable, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() +} + +func TestEntryProbeToFailed(t *testing.T) { + c := DefaultNUDConfigurations() + c.MaxMulticastProbes = 3 + c.MaxUnicastProbes = 3 + e, nudDisp, linkRes, clock := entryTestSetup(c) + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + waitFor := c.DelayFirstProbeTime + c.RetransmitTimer*time.Duration(c.MaxUnicastProbes) + clock.advance(waitFor) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The next three probe are caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + { + EventType: entryTestRemoved, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + e.mu.Lock() + if got, want := e.neigh.State, Failed; got != want { + t.Errorf("got e.neigh.State = %q, want = %q", got, want) + } + e.mu.Unlock() +} + +func TestEntryFailedGetsDeleted(t *testing.T) { + c := DefaultNUDConfigurations() + c.MaxMulticastProbes = 3 + c.MaxUnicastProbes = 3 + e, nudDisp, linkRes, clock := entryTestSetup(c) + + // Verify the cache contains the entry. + if _, ok := e.nic.neigh.cache[entryTestAddr1]; !ok { + t.Errorf("expected entry %q to exist in the neighbor cache", entryTestAddr1) + } + + e.mu.Lock() + e.handlePacketQueuedLocked() + e.handleConfirmationLocked(entryTestLinkAddr1, ReachabilityConfirmationFlags{ + Solicited: false, + Override: false, + IsRouter: false, + }) + e.handlePacketQueuedLocked() + e.mu.Unlock() + + waitFor := c.DelayFirstProbeTime + c.RetransmitTimer*time.Duration(c.MaxUnicastProbes) + c.UnreachableTime + clock.advance(waitFor) + + wantProbes := []entryTestProbeInfo{ + // The first probe is caused by the Unknown-to-Incomplete transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: tcpip.LinkAddress(""), + LocalAddress: entryTestAddr2, + }, + // The next three probe are caused by the Delay-to-Probe transition. + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + { + RemoteAddress: entryTestAddr1, + RemoteLinkAddress: entryTestLinkAddr1, + LocalAddress: entryTestAddr2, + }, + } + linkRes.mu.Lock() + diff := cmp.Diff(linkRes.probes, wantProbes) + linkRes.mu.Unlock() + if diff != "" { + t.Fatalf("link address resolver probes mismatch (-got, +want):\n%s", diff) + } + + wantEvents := []testEntryEventInfo{ + { + EventType: entryTestAdded, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: tcpip.LinkAddress(""), + State: Incomplete, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Stale, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Delay, + }, + { + EventType: entryTestChanged, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + { + EventType: entryTestRemoved, + NICID: entryTestNICID, + Addr: entryTestAddr1, + LinkAddr: entryTestLinkAddr1, + State: Probe, + }, + } + nudDisp.mu.Lock() + if diff := cmp.Diff(nudDisp.events, wantEvents, eventDiffOpts()...); diff != "" { + t.Errorf("nud dispatcher events mismatch (-got, +want):\n%s", diff) + } + nudDisp.mu.Unlock() + + // Verify the cache no longer contains the entry. + if _, ok := e.nic.neigh.cache[entryTestAddr1]; ok { + t.Errorf("entry %q should have been deleted from the neighbor cache", entryTestAddr1) + } +} diff --git a/pkg/tcpip/stack/neighborstate_string.go b/pkg/tcpip/stack/neighborstate_string.go new file mode 100644 index 000000000..aa7311ec6 --- /dev/null +++ b/pkg/tcpip/stack/neighborstate_string.go @@ -0,0 +1,44 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Code generated by "stringer -type NeighborState"; DO NOT EDIT. + +package stack + +import "strconv" + +func _() { + // An "invalid array index" compiler error signifies that the constant values have changed. + // Re-run the stringer command to generate them again. + var x [1]struct{} + _ = x[Unknown-0] + _ = x[Incomplete-1] + _ = x[Reachable-2] + _ = x[Stale-3] + _ = x[Delay-4] + _ = x[Probe-5] + _ = x[Static-6] + _ = x[Failed-7] +} + +const _NeighborState_name = "UnknownIncompleteReachableStaleDelayProbeStaticFailed" + +var _NeighborState_index = [...]uint8{0, 7, 17, 26, 31, 36, 41, 47, 53} + +func (i NeighborState) String() string { + if i >= NeighborState(len(_NeighborState_index)-1) { + return "NeighborState(" + strconv.FormatInt(int64(i), 10) + ")" + } + return _NeighborState_name[_NeighborState_index[i]:_NeighborState_index[i+1]] +} diff --git a/pkg/tcpip/stack/nic.go b/pkg/tcpip/stack/nic.go index 9256d4d43..f21066fce 100644 --- a/pkg/tcpip/stack/nic.go +++ b/pkg/tcpip/stack/nic.go @@ -16,6 +16,7 @@ package stack import ( "fmt" + "math/rand" "reflect" "sort" "strings" @@ -45,6 +46,7 @@ type NIC struct { context NICContext stats NICStats + neigh *neighborCache mu struct { sync.RWMutex @@ -141,6 +143,16 @@ func newNIC(stack *Stack, id tcpip.NICID, name string, ep LinkEndpoint, ctx NICC nic.mu.packetEPs[netProto.Number()] = []PacketEndpoint{} } + // Check for Neighbor Unreachability Detection support. + if ep.Capabilities()&CapabilityResolutionRequired != 0 && len(stack.linkAddrResolvers) != 0 { + rng := rand.New(rand.NewSource(stack.clock.NowNanoseconds())) + nic.neigh = &neighborCache{ + nic: nic, + state: NewNUDState(stack.nudConfigs, rng), + cache: make(map[tcpip.Address]*neighborEntry, neighborCacheSize), + } + } + nic.linkEP.Attach(nic) return nic @@ -1540,6 +1552,27 @@ func (n *NIC) setNDPConfigs(c NDPConfigurations) { n.mu.Unlock() } +// NUDConfigs gets the NUD configurations for n. +func (n *NIC) NUDConfigs() (NUDConfigurations, *tcpip.Error) { + if n.neigh == nil { + return NUDConfigurations{}, tcpip.ErrNotSupported + } + return n.neigh.config(), nil +} + +// setNUDConfigs sets the NUD configurations for n. +// +// Note, if c contains invalid NUD configuration values, it will be fixed to +// use default values for the erroneous values. +func (n *NIC) setNUDConfigs(c NUDConfigurations) *tcpip.Error { + if n.neigh == nil { + return tcpip.ErrNotSupported + } + c.resetInvalidFields() + n.neigh.setConfig(c) + return nil +} + // handleNDPRA handles an NDP Router Advertisement message that arrived on n. func (n *NIC) handleNDPRA(ip tcpip.Address, ra header.NDPRouterAdvert) { n.mu.Lock() diff --git a/pkg/tcpip/stack/nud.go b/pkg/tcpip/stack/nud.go new file mode 100644 index 000000000..f848d50ad --- /dev/null +++ b/pkg/tcpip/stack/nud.go @@ -0,0 +1,466 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack + +import ( + "math" + "sync" + "time" + + "gvisor.dev/gvisor/pkg/tcpip" +) + +const ( + // defaultBaseReachableTime is the default base duration for computing the + // random reachable time. + // + // Reachable time is the duration for which a neighbor is considered + // reachable after a positive reachability confirmation is received. It is a + // function of a uniformly distributed random value between the minimum and + // maximum random factors, multiplied by the base reachable time. Using a + // random component eliminates the possibility that Neighbor Unreachability + // Detection messages will synchronize with each other. + // + // Default taken from REACHABLE_TIME of RFC 4861 section 10. + defaultBaseReachableTime = 30 * time.Second + + // minimumBaseReachableTime is the minimum base duration for computing the + // random reachable time. + // + // Minimum = 1ms + minimumBaseReachableTime = time.Millisecond + + // defaultMinRandomFactor is the default minimum value of the random factor + // used for computing reachable time. + // + // Default taken from MIN_RANDOM_FACTOR of RFC 4861 section 10. + defaultMinRandomFactor = 0.5 + + // defaultMaxRandomFactor is the default maximum value of the random factor + // used for computing reachable time. + // + // The default value depends on the value of MinRandomFactor. + // If MinRandomFactor is less than MAX_RANDOM_FACTOR of RFC 4861 section 10, + // the value from the RFC will be used; otherwise, the default is + // MinRandomFactor multiplied by three. + defaultMaxRandomFactor = 1.5 + + // defaultRetransmitTimer is the default amount of time to wait between + // sending reachability probes. + // + // Default taken from RETRANS_TIMER of RFC 4861 section 10. + defaultRetransmitTimer = time.Second + + // minimumRetransmitTimer is the minimum amount of time to wait between + // sending reachability probes. + // + // Note, RFC 4861 does not impose a minimum Retransmit Timer, but we do here + // to make sure the messages are not sent all at once. We also come to this + // value because in the RetransmitTimer field of a Router Advertisement, a + // value of 0 means unspecified, so the smallest valid value is 1. Note, the + // unit of the RetransmitTimer field in the Router Advertisement is + // milliseconds. + minimumRetransmitTimer = time.Millisecond + + // defaultDelayFirstProbeTime is the default duration to wait for a + // non-Neighbor-Discovery related protocol to reconfirm reachability after + // entering the DELAY state. After this time, a reachability probe will be + // sent and the entry will transition to the PROBE state. + // + // Default taken from DELAY_FIRST_PROBE_TIME of RFC 4861 section 10. + defaultDelayFirstProbeTime = 5 * time.Second + + // defaultMaxMulticastProbes is the default number of reachabililty probes + // to send before concluding negative reachability and deleting the neighbor + // entry from the INCOMPLETE state. + // + // Default taken from MAX_MULTICAST_SOLICIT of RFC 4861 section 10. + defaultMaxMulticastProbes = 3 + + // defaultMaxUnicastProbes is the default number of reachability probes to + // send before concluding retransmission from within the PROBE state should + // cease and the entry SHOULD be deleted. + // + // Default taken from MAX_UNICASE_SOLICIT of RFC 4861 section 10. + defaultMaxUnicastProbes = 3 + + // defaultMaxAnycastDelayTime is the default time in which the stack SHOULD + // delay sending a response for a random time between 0 and this time, if the + // target address is an anycast address. + // + // Default taken from MAX_ANYCAST_DELAY_TIME of RFC 4861 section 10. + defaultMaxAnycastDelayTime = time.Second + + // defaultMaxReachbilityConfirmations is the default amount of unsolicited + // reachability confirmation messages a node MAY send to all-node multicast + // address when it determines its link-layer address has changed. + // + // Default taken from MAX_NEIGHBOR_ADVERTISEMENT of RFC 4861 section 10. + defaultMaxReachbilityConfirmations = 3 + + // defaultUnreachableTime is the default duration for how long an entry will + // remain in the FAILED state before being removed from the neighbor cache. + // + // Note, there is no equivalent protocol constant defined in RFC 4861. It + // leaves the specifics of any garbage collection mechanism up to the + // implementation. + defaultUnreachableTime = 5 * time.Second +) + +// NUDDispatcher is the interface integrators of netstack must implement to +// receive and handle NUD related events. +type NUDDispatcher interface { + // OnNeighborAdded will be called when a new entry is added to a NIC's (with + // ID nicID) neighbor table. + // + // This function is permitted to block indefinitely without interfering with + // the stack's operation. + // + // May be called concurrently. + OnNeighborAdded(nicID tcpip.NICID, ipAddr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) + + // OnNeighborChanged will be called when an entry in a NIC's (with ID nicID) + // neighbor table changes state and/or link address. + // + // This function is permitted to block indefinitely without interfering with + // the stack's operation. + // + // May be called concurrently. + OnNeighborChanged(nicID tcpip.NICID, ipAddr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) + + // OnNeighborRemoved will be called when an entry is removed from a NIC's + // (with ID nicID) neighbor table. + // + // This function is permitted to block indefinitely without interfering with + // the stack's operation. + // + // May be called concurrently. + OnNeighborRemoved(nicID tcpip.NICID, ipAddr tcpip.Address, linkAddr tcpip.LinkAddress, state NeighborState, updatedAt time.Time) +} + +// ReachabilityConfirmationFlags describes the flags used within a reachability +// confirmation (e.g. ARP reply or Neighbor Advertisement for ARP or NDP, +// respectively). +type ReachabilityConfirmationFlags struct { + // Solicited indicates that the advertisement was sent in response to a + // reachability probe. + Solicited bool + + // Override indicates that the reachability confirmation should override an + // existing neighbor cache entry and update the cached link-layer address. + // When Override is not set the confirmation will not update a cached + // link-layer address, but will update an existing neighbor cache entry for + // which no link-layer address is known. + Override bool + + // IsRouter indicates that the sender is a router. + IsRouter bool +} + +// NUDHandler communicates external events to the Neighbor Unreachability +// Detection state machine, which is implemented per-interface. This is used by +// network endpoints to inform the Neighbor Cache of probes and confirmations. +type NUDHandler interface { + // HandleProbe processes an incoming neighbor probe (e.g. ARP request or + // Neighbor Solicitation for ARP or NDP, respectively). Validation of the + // probe needs to be performed before calling this function since the + // Neighbor Cache doesn't have access to view the NIC's assigned addresses. + HandleProbe(remoteAddr, localAddr tcpip.Address, protocol tcpip.NetworkProtocolNumber, remoteLinkAddr tcpip.LinkAddress) + + // HandleConfirmation processes an incoming neighbor confirmation (e.g. ARP + // reply or Neighbor Advertisement for ARP or NDP, respectively). + HandleConfirmation(addr tcpip.Address, linkAddr tcpip.LinkAddress, flags ReachabilityConfirmationFlags) + + // HandleUpperLevelConfirmation processes an incoming upper-level protocol + // (e.g. TCP acknowledgements) reachability confirmation. + HandleUpperLevelConfirmation(addr tcpip.Address) +} + +// NUDConfigurations is the NUD configurations for the netstack. This is used +// by the neighbor cache to operate the NUD state machine on each device in the +// local network. +type NUDConfigurations struct { + // BaseReachableTime is the base duration for computing the random reachable + // time. + // + // Reachable time is the duration for which a neighbor is considered + // reachable after a positive reachability confirmation is received. It is a + // function of uniformly distributed random value between minRandomFactor and + // maxRandomFactor multiplied by baseReachableTime. Using a random component + // eliminates the possibility that Neighbor Unreachability Detection messages + // will synchronize with each other. + // + // After this time, a neighbor entry will transition from REACHABLE to STALE + // state. + // + // Must be greater than 0. + BaseReachableTime time.Duration + + // LearnBaseReachableTime enables learning BaseReachableTime during runtime + // from the neighbor discovery protocol, if supported. + // + // TODO(gvisor.dev/issue/2240): Implement this NUD configuration option. + LearnBaseReachableTime bool + + // MinRandomFactor is the minimum value of the random factor used for + // computing reachable time. + // + // See BaseReachbleTime for more information on computing the reachable time. + // + // Must be greater than 0. + MinRandomFactor float32 + + // MaxRandomFactor is the maximum value of the random factor used for + // computing reachabile time. + // + // See BaseReachbleTime for more information on computing the reachable time. + // + // Must be great than or equal to MinRandomFactor. + MaxRandomFactor float32 + + // RetransmitTimer is the duration between retransmission of reachability + // probes in the PROBE state. + RetransmitTimer time.Duration + + // LearnRetransmitTimer enables learning RetransmitTimer during runtime from + // the neighbor discovery protocol, if supported. + // + // TODO(gvisor.dev/issue/2241): Implement this NUD configuration option. + LearnRetransmitTimer bool + + // DelayFirstProbeTime is the duration to wait for a non-Neighbor-Discovery + // related protocol to reconfirm reachability after entering the DELAY state. + // After this time, a reachability probe will be sent and the entry will + // transition to the PROBE state. + // + // Must be greater than 0. + DelayFirstProbeTime time.Duration + + // MaxMulticastProbes is the number of reachability probes to send before + // concluding negative reachability and deleting the neighbor entry from the + // INCOMPLETE state. + // + // Must be greater than 0. + MaxMulticastProbes uint32 + + // MaxUnicastProbes is the number of reachability probes to send before + // concluding retransmission from within the PROBE state should cease and + // entry SHOULD be deleted. + // + // Must be greater than 0. + MaxUnicastProbes uint32 + + // MaxAnycastDelayTime is the time in which the stack SHOULD delay sending a + // response for a random time between 0 and this time, if the target address + // is an anycast address. + // + // TODO(gvisor.dev/issue/2242): Use this option when sending solicited + // neighbor confirmations to anycast addresses and proxying neighbor + // confirmations. + MaxAnycastDelayTime time.Duration + + // MaxReachabilityConfirmations is the number of unsolicited reachability + // confirmation messages a node MAY send to all-node multicast address when + // it determines its link-layer address has changed. + // + // TODO(gvisor.dev/issue/2246): Discuss if implementation of this NUD + // configuration option is necessary. + MaxReachabilityConfirmations uint32 + + // UnreachableTime describes how long an entry will remain in the FAILED + // state before being removed from the neighbor cache. + UnreachableTime time.Duration +} + +// DefaultNUDConfigurations returns a NUDConfigurations populated with default +// values defined by RFC 4861 section 10. +func DefaultNUDConfigurations() NUDConfigurations { + return NUDConfigurations{ + BaseReachableTime: defaultBaseReachableTime, + LearnBaseReachableTime: true, + MinRandomFactor: defaultMinRandomFactor, + MaxRandomFactor: defaultMaxRandomFactor, + RetransmitTimer: defaultRetransmitTimer, + LearnRetransmitTimer: true, + DelayFirstProbeTime: defaultDelayFirstProbeTime, + MaxMulticastProbes: defaultMaxMulticastProbes, + MaxUnicastProbes: defaultMaxUnicastProbes, + MaxAnycastDelayTime: defaultMaxAnycastDelayTime, + MaxReachabilityConfirmations: defaultMaxReachbilityConfirmations, + UnreachableTime: defaultUnreachableTime, + } +} + +// resetInvalidFields modifies an invalid NDPConfigurations with valid values. +// If invalid values are present in c, the corresponding default values will be +// used instead. This is needed to check, and conditionally fix, user-specified +// NUDConfigurations. +func (c *NUDConfigurations) resetInvalidFields() { + if c.BaseReachableTime < minimumBaseReachableTime { + c.BaseReachableTime = defaultBaseReachableTime + } + if c.MinRandomFactor <= 0 { + c.MinRandomFactor = defaultMinRandomFactor + } + if c.MaxRandomFactor < c.MinRandomFactor { + c.MaxRandomFactor = calcMaxRandomFactor(c.MinRandomFactor) + } + if c.RetransmitTimer < minimumRetransmitTimer { + c.RetransmitTimer = defaultRetransmitTimer + } + if c.DelayFirstProbeTime == 0 { + c.DelayFirstProbeTime = defaultDelayFirstProbeTime + } + if c.MaxMulticastProbes == 0 { + c.MaxMulticastProbes = defaultMaxMulticastProbes + } + if c.MaxUnicastProbes == 0 { + c.MaxUnicastProbes = defaultMaxUnicastProbes + } + if c.UnreachableTime == 0 { + c.UnreachableTime = defaultUnreachableTime + } +} + +// calcMaxRandomFactor calculates the maximum value of the random factor used +// for computing reachable time. This function is necessary for when the +// default specified in RFC 4861 section 10 is less than the current +// MinRandomFactor. +// +// Assumes minRandomFactor is positive since validation of the minimum value +// should come before the validation of the maximum. +func calcMaxRandomFactor(minRandomFactor float32) float32 { + if minRandomFactor > defaultMaxRandomFactor { + return minRandomFactor * 3 + } + return defaultMaxRandomFactor +} + +// A Rand is a source of random numbers. +type Rand interface { + // Float32 returns, as a float32, a pseudo-random number in [0.0,1.0). + Float32() float32 +} + +// NUDState stores states needed for calculating reachable time. +type NUDState struct { + rng Rand + + // mu protects the fields below. + // + // It is necessary for NUDState to handle its own locking since neighbor + // entries may access the NUD state from within the goroutine spawned by + // time.AfterFunc(). This goroutine may run concurrently with the main + // process for controlling the neighbor cache and would otherwise introduce + // race conditions if NUDState was not locked properly. + mu sync.RWMutex + + config NUDConfigurations + + // reachableTime is the duration to wait for a REACHABLE entry to + // transition into STALE after inactivity. This value is calculated with + // the algorithm defined in RFC 4861 section 6.3.2. + reachableTime time.Duration + + expiration time.Time + prevBaseReachableTime time.Duration + prevMinRandomFactor float32 + prevMaxRandomFactor float32 +} + +// NewNUDState returns new NUDState using c as configuration and the specified +// random number generator for use in recomputing ReachableTime. +func NewNUDState(c NUDConfigurations, rng Rand) *NUDState { + s := &NUDState{ + rng: rng, + } + s.config = c + return s +} + +// Config returns the NUD configuration. +func (s *NUDState) Config() NUDConfigurations { + s.mu.RLock() + defer s.mu.RUnlock() + return s.config +} + +// SetConfig replaces the existing NUD configurations with c. +func (s *NUDState) SetConfig(c NUDConfigurations) { + s.mu.Lock() + defer s.mu.Unlock() + s.config = c +} + +// ReachableTime returns the duration to wait for a REACHABLE entry to +// transition into STALE after inactivity. This value is recalculated for new +// values of BaseReachableTime, MinRandomFactor, and MaxRandomFactor using the +// algorithm defined in RFC 4861 section 6.3.2. +func (s *NUDState) ReachableTime() time.Duration { + s.mu.Lock() + defer s.mu.Unlock() + + if time.Now().After(s.expiration) || + s.config.BaseReachableTime != s.prevBaseReachableTime || + s.config.MinRandomFactor != s.prevMinRandomFactor || + s.config.MaxRandomFactor != s.prevMaxRandomFactor { + return s.recomputeReachableTimeLocked() + } + return s.reachableTime +} + +// recomputeReachableTimeLocked forces a recalculation of ReachableTime using +// the algorithm defined in RFC 4861 section 6.3.2. +// +// This SHOULD automatically be invoked during certain situations, as per +// RFC 4861 section 6.3.4: +// +// If the received Reachable Time value is non-zero, the host SHOULD set its +// BaseReachableTime variable to the received value. If the new value +// differs from the previous value, the host SHOULD re-compute a new random +// ReachableTime value. ReachableTime is computed as a uniformly +// distributed random value between MIN_RANDOM_FACTOR and MAX_RANDOM_FACTOR +// times the BaseReachableTime. Using a random component eliminates the +// possibility that Neighbor Unreachability Detection messages will +// synchronize with each other. +// +// In most cases, the advertised Reachable Time value will be the same in +// consecutive Router Advertisements, and a host's BaseReachableTime rarely +// changes. In such cases, an implementation SHOULD ensure that a new +// random value gets re-computed at least once every few hours. +// +// s.mu MUST be locked for writing. +func (s *NUDState) recomputeReachableTimeLocked() time.Duration { + s.prevBaseReachableTime = s.config.BaseReachableTime + s.prevMinRandomFactor = s.config.MinRandomFactor + s.prevMaxRandomFactor = s.config.MaxRandomFactor + + randomFactor := s.config.MinRandomFactor + s.rng.Float32()*(s.config.MaxRandomFactor-s.config.MinRandomFactor) + + // Check for overflow, given that minRandomFactor and maxRandomFactor are + // guaranteed to be positive numbers. + if float32(math.MaxInt64)/randomFactor < float32(s.config.BaseReachableTime) { + s.reachableTime = time.Duration(math.MaxInt64) + } else if randomFactor == 1 { + // Avoid loss of precision when a large base reachable time is used. + s.reachableTime = s.config.BaseReachableTime + } else { + reachableTime := int64(float32(s.config.BaseReachableTime) * randomFactor) + s.reachableTime = time.Duration(reachableTime) + } + + s.expiration = time.Now().Add(2 * time.Hour) + return s.reachableTime +} diff --git a/pkg/tcpip/stack/nud_test.go b/pkg/tcpip/stack/nud_test.go new file mode 100644 index 000000000..2494ee610 --- /dev/null +++ b/pkg/tcpip/stack/nud_test.go @@ -0,0 +1,795 @@ +// Copyright 2020 The gVisor Authors. +// +// Licensed under the Apache License, Version 2.0 (the "License"); +// you may not use this file except in compliance with the License. +// You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +package stack_test + +import ( + "math" + "testing" + "time" + + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/link/channel" + "gvisor.dev/gvisor/pkg/tcpip/network/ipv6" + "gvisor.dev/gvisor/pkg/tcpip/stack" +) + +const ( + defaultBaseReachableTime = 30 * time.Second + minimumBaseReachableTime = time.Millisecond + defaultMinRandomFactor = 0.5 + defaultMaxRandomFactor = 1.5 + defaultRetransmitTimer = time.Second + minimumRetransmitTimer = time.Millisecond + defaultDelayFirstProbeTime = 5 * time.Second + defaultMaxMulticastProbes = 3 + defaultMaxUnicastProbes = 3 + defaultMaxAnycastDelayTime = time.Second + defaultMaxReachbilityConfirmations = 3 + defaultUnreachableTime = 5 * time.Second + + defaultFakeRandomNum = 0.5 +) + +// fakeRand is a deterministic random number generator. +type fakeRand struct { + num float32 +} + +var _ stack.Rand = (*fakeRand)(nil) + +func (f *fakeRand) Float32() float32 { + return f.num +} + +// TestSetNUDConfigurationFailsForBadNICID tests to make sure we get an error if +// we attempt to update NUD configurations using an invalid NICID. +func TestSetNUDConfigurationFailsForBadNICID(t *testing.T) { + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The networking + // stack will only allocate neighbor caches if a protocol providing link + // address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + }) + + // No NIC with ID 1 yet. + config := stack.NUDConfigurations{} + if err := s.SetNUDConfigurations(1, config); err != tcpip.ErrUnknownNICID { + t.Fatalf("got s.SetNDPConfigurations(1, %+v) = %v, want = %s", config, err, tcpip.ErrUnknownNICID) + } +} + +// TestNUDConfigurationFailsForNotSupported tests to make sure we get a +// NotSupported error if we attempt to retrieve NUD configurations when the +// stack doesn't support NUD. +// +// The stack will report to not support NUD if a neighbor cache for a given NIC +// is not allocated. The networking stack will only allocate neighbor caches if +// a protocol providing link address resolution is specified (e.g. ARP, IPv6). +func TestNUDConfigurationFailsForNotSupported(t *testing.T) { + const nicID = 1 + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + NUDConfigs: stack.DefaultNUDConfigurations(), + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + if _, err := s.NUDConfigurations(nicID); err != tcpip.ErrNotSupported { + t.Fatalf("got s.NDPConfigurations(%d) = %v, want = %s", nicID, err, tcpip.ErrNotSupported) + } +} + +// TestNUDConfigurationFailsForNotSupported tests to make sure we get a +// NotSupported error if we attempt to set NUD configurations when the stack +// doesn't support NUD. +// +// The stack will report to not support NUD if a neighbor cache for a given NIC +// is not allocated. The networking stack will only allocate neighbor caches if +// a protocol providing link address resolution is specified (e.g. ARP, IPv6). +func TestSetNUDConfigurationFailsForNotSupported(t *testing.T) { + const nicID = 1 + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + NUDConfigs: stack.DefaultNUDConfigurations(), + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + + config := stack.NUDConfigurations{} + if err := s.SetNUDConfigurations(nicID, config); err != tcpip.ErrNotSupported { + t.Fatalf("got s.SetNDPConfigurations(%d, %+v) = %v, want = %s", nicID, config, err, tcpip.ErrNotSupported) + } +} + +// TestDefaultNUDConfigurationIsValid verifies that calling +// resetInvalidFields() on the result of DefaultNUDConfigurations() does not +// change anything. DefaultNUDConfigurations() should return a valid +// NUDConfigurations. +func TestDefaultNUDConfigurations(t *testing.T) { + const nicID = 1 + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The networking + // stack will only allocate neighbor caches if a protocol providing link + // address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: stack.DefaultNUDConfigurations(), + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + c, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got, want := c, stack.DefaultNUDConfigurations(); got != want { + t.Errorf("got stack.NUDConfigurations(%d) = %+v, want = %+v", nicID, got, want) + } +} + +func TestNUDConfigurationsBaseReachableTime(t *testing.T) { + tests := []struct { + name string + baseReachableTime time.Duration + want time.Duration + }{ + // Invalid cases + { + name: "EqualToZero", + baseReachableTime: 0, + want: defaultBaseReachableTime, + }, + // Valid cases + { + name: "MoreThanZero", + baseReachableTime: time.Millisecond, + want: time.Millisecond, + }, + { + name: "MoreThanDefaultBaseReachableTime", + baseReachableTime: 2 * defaultBaseReachableTime, + want: 2 * defaultBaseReachableTime, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.BaseReachableTime = test.baseReachableTime + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.BaseReachableTime; got != test.want { + t.Errorf("got BaseReachableTime = %q, want = %q", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsMinRandomFactor(t *testing.T) { + tests := []struct { + name string + minRandomFactor float32 + want float32 + }{ + // Invalid cases + { + name: "LessThanZero", + minRandomFactor: -1, + want: defaultMinRandomFactor, + }, + { + name: "EqualToZero", + minRandomFactor: 0, + want: defaultMinRandomFactor, + }, + // Valid cases + { + name: "MoreThanZero", + minRandomFactor: 1, + want: 1, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.MinRandomFactor = test.minRandomFactor + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.MinRandomFactor; got != test.want { + t.Errorf("got MinRandomFactor = %f, want = %f", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsMaxRandomFactor(t *testing.T) { + tests := []struct { + name string + minRandomFactor float32 + maxRandomFactor float32 + want float32 + }{ + // Invalid cases + { + name: "LessThanZero", + minRandomFactor: defaultMinRandomFactor, + maxRandomFactor: -1, + want: defaultMaxRandomFactor, + }, + { + name: "EqualToZero", + minRandomFactor: defaultMinRandomFactor, + maxRandomFactor: 0, + want: defaultMaxRandomFactor, + }, + { + name: "LessThanMinRandomFactor", + minRandomFactor: defaultMinRandomFactor, + maxRandomFactor: defaultMinRandomFactor * 0.99, + want: defaultMaxRandomFactor, + }, + { + name: "MoreThanMinRandomFactorWhenMinRandomFactorIsLargerThanMaxRandomFactorDefault", + minRandomFactor: defaultMaxRandomFactor * 2, + maxRandomFactor: defaultMaxRandomFactor, + want: defaultMaxRandomFactor * 6, + }, + // Valid cases + { + name: "EqualToMinRandomFactor", + minRandomFactor: defaultMinRandomFactor, + maxRandomFactor: defaultMinRandomFactor, + want: defaultMinRandomFactor, + }, + { + name: "MoreThanMinRandomFactor", + minRandomFactor: defaultMinRandomFactor, + maxRandomFactor: defaultMinRandomFactor * 1.1, + want: defaultMinRandomFactor * 1.1, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.MinRandomFactor = test.minRandomFactor + c.MaxRandomFactor = test.maxRandomFactor + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.MaxRandomFactor; got != test.want { + t.Errorf("got MaxRandomFactor = %f, want = %f", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsRetransmitTimer(t *testing.T) { + tests := []struct { + name string + retransmitTimer time.Duration + want time.Duration + }{ + // Invalid cases + { + name: "EqualToZero", + retransmitTimer: 0, + want: defaultRetransmitTimer, + }, + { + name: "LessThanMinimumRetransmitTimer", + retransmitTimer: minimumRetransmitTimer - time.Nanosecond, + want: defaultRetransmitTimer, + }, + // Valid cases + { + name: "EqualToMinimumRetransmitTimer", + retransmitTimer: minimumRetransmitTimer, + want: minimumBaseReachableTime, + }, + { + name: "LargetThanMinimumRetransmitTimer", + retransmitTimer: 2 * minimumBaseReachableTime, + want: 2 * minimumBaseReachableTime, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.RetransmitTimer = test.retransmitTimer + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.RetransmitTimer; got != test.want { + t.Errorf("got RetransmitTimer = %q, want = %q", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsDelayFirstProbeTime(t *testing.T) { + tests := []struct { + name string + delayFirstProbeTime time.Duration + want time.Duration + }{ + // Invalid cases + { + name: "EqualToZero", + delayFirstProbeTime: 0, + want: defaultDelayFirstProbeTime, + }, + // Valid cases + { + name: "MoreThanZero", + delayFirstProbeTime: time.Millisecond, + want: time.Millisecond, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.DelayFirstProbeTime = test.delayFirstProbeTime + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.DelayFirstProbeTime; got != test.want { + t.Errorf("got DelayFirstProbeTime = %q, want = %q", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsMaxMulticastProbes(t *testing.T) { + tests := []struct { + name string + maxMulticastProbes uint32 + want uint32 + }{ + // Invalid cases + { + name: "EqualToZero", + maxMulticastProbes: 0, + want: defaultMaxMulticastProbes, + }, + // Valid cases + { + name: "MoreThanZero", + maxMulticastProbes: 1, + want: 1, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.MaxMulticastProbes = test.maxMulticastProbes + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.MaxMulticastProbes; got != test.want { + t.Errorf("got MaxMulticastProbes = %q, want = %q", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsMaxUnicastProbes(t *testing.T) { + tests := []struct { + name string + maxUnicastProbes uint32 + want uint32 + }{ + // Invalid cases + { + name: "EqualToZero", + maxUnicastProbes: 0, + want: defaultMaxUnicastProbes, + }, + // Valid cases + { + name: "MoreThanZero", + maxUnicastProbes: 1, + want: 1, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.MaxUnicastProbes = test.maxUnicastProbes + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.MaxUnicastProbes; got != test.want { + t.Errorf("got MaxUnicastProbes = %q, want = %q", got, test.want) + } + }) + } +} + +func TestNUDConfigurationsUnreachableTime(t *testing.T) { + tests := []struct { + name string + unreachableTime time.Duration + want time.Duration + }{ + // Invalid cases + { + name: "EqualToZero", + unreachableTime: 0, + want: defaultUnreachableTime, + }, + // Valid cases + { + name: "MoreThanZero", + unreachableTime: time.Millisecond, + want: time.Millisecond, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + const nicID = 1 + + c := stack.DefaultNUDConfigurations() + c.UnreachableTime = test.unreachableTime + + e := channel.New(0, 1280, linkAddr1) + e.LinkEPCapabilities |= stack.CapabilityResolutionRequired + + s := stack.New(stack.Options{ + // A neighbor cache is required to store NUDConfigurations. The + // networking stack will only allocate neighbor caches if a protocol + // providing link address resolution is specified (e.g. ARP or IPv6). + NetworkProtocols: []stack.NetworkProtocol{ipv6.NewProtocol()}, + NUDConfigs: c, + }) + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("CreateNIC(%d, _) = %s", nicID, err) + } + sc, err := s.NUDConfigurations(nicID) + if err != nil { + t.Fatalf("got stack.NUDConfigurations(%d) = %s", nicID, err) + } + if got := sc.UnreachableTime; got != test.want { + t.Errorf("got UnreachableTime = %q, want = %q", got, test.want) + } + }) + } +} + +// TestNUDStateReachableTime verifies the correctness of the ReachableTime +// computation. +func TestNUDStateReachableTime(t *testing.T) { + tests := []struct { + name string + baseReachableTime time.Duration + minRandomFactor float32 + maxRandomFactor float32 + want time.Duration + }{ + { + name: "AllZeros", + baseReachableTime: 0, + minRandomFactor: 0, + maxRandomFactor: 0, + want: 0, + }, + { + name: "ZeroMaxRandomFactor", + baseReachableTime: time.Second, + minRandomFactor: 0, + maxRandomFactor: 0, + want: 0, + }, + { + name: "ZeroMinRandomFactor", + baseReachableTime: time.Second, + minRandomFactor: 0, + maxRandomFactor: 1, + want: time.Duration(defaultFakeRandomNum * float32(time.Second)), + }, + { + name: "FractionalRandomFactor", + baseReachableTime: time.Duration(math.MaxInt64), + minRandomFactor: 0.001, + maxRandomFactor: 0.002, + want: time.Duration((0.001 + (0.001 * defaultFakeRandomNum)) * float32(math.MaxInt64)), + }, + { + name: "MinAndMaxRandomFactorsEqual", + baseReachableTime: time.Second, + minRandomFactor: 1, + maxRandomFactor: 1, + want: time.Second, + }, + { + name: "MinAndMaxRandomFactorsDifferent", + baseReachableTime: time.Second, + minRandomFactor: 1, + maxRandomFactor: 2, + want: time.Duration((1.0 + defaultFakeRandomNum) * float32(time.Second)), + }, + { + name: "MaxInt64", + baseReachableTime: time.Duration(math.MaxInt64), + minRandomFactor: 1, + maxRandomFactor: 1, + want: time.Duration(math.MaxInt64), + }, + { + name: "Overflow", + baseReachableTime: time.Duration(math.MaxInt64), + minRandomFactor: 1.5, + maxRandomFactor: 1.5, + want: time.Duration(math.MaxInt64), + }, + { + name: "DoubleOverflow", + baseReachableTime: time.Duration(math.MaxInt64), + minRandomFactor: 2.5, + maxRandomFactor: 2.5, + want: time.Duration(math.MaxInt64), + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + c := stack.NUDConfigurations{ + BaseReachableTime: test.baseReachableTime, + MinRandomFactor: test.minRandomFactor, + MaxRandomFactor: test.maxRandomFactor, + } + // A fake random number generator is used to ensure deterministic + // results. + rng := fakeRand{ + num: defaultFakeRandomNum, + } + s := stack.NewNUDState(c, &rng) + if got, want := s.ReachableTime(), test.want; got != want { + t.Errorf("got ReachableTime = %q, want = %q", got, want) + } + }) + } +} + +// TestNUDStateRecomputeReachableTime exercises the ReachableTime function +// twice to verify recomputation of reachable time when the min random factor, +// max random factor, or base reachable time changes. +func TestNUDStateRecomputeReachableTime(t *testing.T) { + const defaultBase = time.Second + const defaultMin = 2.0 * defaultMaxRandomFactor + const defaultMax = 3.0 * defaultMaxRandomFactor + + tests := []struct { + name string + baseReachableTime time.Duration + minRandomFactor float32 + maxRandomFactor float32 + want time.Duration + }{ + { + name: "BaseReachableTime", + baseReachableTime: 2 * defaultBase, + minRandomFactor: defaultMin, + maxRandomFactor: defaultMax, + want: time.Duration((defaultMin + (defaultMax-defaultMin)*defaultFakeRandomNum) * float32(2*defaultBase)), + }, + { + name: "MinRandomFactor", + baseReachableTime: defaultBase, + minRandomFactor: defaultMax, + maxRandomFactor: defaultMax, + want: time.Duration(defaultMax * float32(defaultBase)), + }, + { + name: "MaxRandomFactor", + baseReachableTime: defaultBase, + minRandomFactor: defaultMin, + maxRandomFactor: defaultMin, + want: time.Duration(defaultMin * float32(defaultBase)), + }, + { + name: "BothRandomFactor", + baseReachableTime: defaultBase, + minRandomFactor: 2 * defaultMin, + maxRandomFactor: 2 * defaultMax, + want: time.Duration((2*defaultMin + (2*defaultMax-2*defaultMin)*defaultFakeRandomNum) * float32(defaultBase)), + }, + { + name: "BaseReachableTimeAndBothRandomFactors", + baseReachableTime: 2 * defaultBase, + minRandomFactor: 2 * defaultMin, + maxRandomFactor: 2 * defaultMax, + want: time.Duration((2*defaultMin + (2*defaultMax-2*defaultMin)*defaultFakeRandomNum) * float32(2*defaultBase)), + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + c := stack.DefaultNUDConfigurations() + c.BaseReachableTime = defaultBase + c.MinRandomFactor = defaultMin + c.MaxRandomFactor = defaultMax + + // A fake random number generator is used to ensure deterministic + // results. + rng := fakeRand{ + num: defaultFakeRandomNum, + } + s := stack.NewNUDState(c, &rng) + old := s.ReachableTime() + + if got, want := s.ReachableTime(), old; got != want { + t.Errorf("got ReachableTime = %q, want = %q", got, want) + } + + // Check for recomputation when changing the min random factor, the max + // random factor, the base reachability time, or any permutation of those + // three options. + c.BaseReachableTime = test.baseReachableTime + c.MinRandomFactor = test.minRandomFactor + c.MaxRandomFactor = test.maxRandomFactor + s.SetConfig(c) + + if got, want := s.ReachableTime(), test.want; got != want { + t.Errorf("got ReachableTime = %q, want = %q", got, want) + } + + // Verify that ReachableTime isn't recomputed when none of the + // configuration options change. The random factor is changed so that if + // a recompution were to occur, ReachableTime would change. + rng.num = defaultFakeRandomNum / 2.0 + if got, want := s.ReachableTime(), test.want; got != want { + t.Errorf("got ReachableTime = %q, want = %q", got, want) + } + }) + } +} diff --git a/pkg/tcpip/stack/route.go b/pkg/tcpip/stack/route.go index d65f8049e..91e0110f1 100644 --- a/pkg/tcpip/stack/route.go +++ b/pkg/tcpip/stack/route.go @@ -48,6 +48,10 @@ type Route struct { // Loop controls where WritePacket should send packets. Loop PacketLooping + + // directedBroadcast indicates whether this route is sending a directed + // broadcast packet. + directedBroadcast bool } // makeRoute initializes a new route. It takes ownership of the provided @@ -275,6 +279,12 @@ func (r *Route) Stack() *Stack { return r.ref.stack() } +// IsBroadcast returns true if the route is to send a broadcast packet. +func (r *Route) IsBroadcast() bool { + // Only IPv4 has a notion of broadcast. + return r.directedBroadcast || r.RemoteAddress == header.IPv4Broadcast +} + // ReverseRoute returns new route with given source and destination address. func (r *Route) ReverseRoute(src tcpip.Address, dst tcpip.Address) Route { return Route{ diff --git a/pkg/tcpip/stack/stack.go b/pkg/tcpip/stack/stack.go index a6faa22c2..3f07e4159 100644 --- a/pkg/tcpip/stack/stack.go +++ b/pkg/tcpip/stack/stack.go @@ -445,6 +445,9 @@ type Stack struct { // ndpConfigs is the default NDP configurations used by interfaces. ndpConfigs NDPConfigurations + // nudConfigs is the default NUD configurations used by interfaces. + nudConfigs NUDConfigurations + // autoGenIPv6LinkLocal determines whether or not the stack will attempt // to auto-generate an IPv6 link-local address for newly enabled non-loopback // NICs. See the AutoGenIPv6LinkLocal field of Options for more details. @@ -454,6 +457,10 @@ type Stack struct { // integrator NDP related events. ndpDisp NDPDispatcher + // nudDisp is the NUD event dispatcher that is used to send the netstack + // integrator NUD related events. + nudDisp NUDDispatcher + // uniqueIDGenerator is a generator of unique identifiers. uniqueIDGenerator UniqueID @@ -518,6 +525,9 @@ type Options struct { // before assigning an address to a NIC. NDPConfigs NDPConfigurations + // NUDConfigs is the default NUD configurations used by interfaces. + NUDConfigs NUDConfigurations + // AutoGenIPv6LinkLocal determines whether or not the stack will attempt to // auto-generate an IPv6 link-local address for newly enabled non-loopback // NICs. @@ -536,6 +546,10 @@ type Options struct { // receive NDP related events. NDPDisp NDPDispatcher + // NUDDisp is the NUD event dispatcher that an integrator can provide to + // receive NUD related events. + NUDDisp NUDDispatcher + // RawFactory produces raw endpoints. Raw endpoints are enabled only if // this is non-nil. RawFactory RawFactory @@ -670,6 +684,8 @@ func New(opts Options) *Stack { // Make sure opts.NDPConfigs contains valid values only. opts.NDPConfigs.validate() + opts.NUDConfigs.resetInvalidFields() + s := &Stack{ transportProtocols: make(map[tcpip.TransportProtocolNumber]*transportProtocolState), networkProtocols: make(map[tcpip.NetworkProtocolNumber]NetworkProtocol), @@ -685,9 +701,11 @@ func New(opts Options) *Stack { icmpRateLimiter: NewICMPRateLimiter(), seed: generateRandUint32(), ndpConfigs: opts.NDPConfigs, + nudConfigs: opts.NUDConfigs, autoGenIPv6LinkLocal: opts.AutoGenIPv6LinkLocal, uniqueIDGenerator: opts.UniqueID, ndpDisp: opts.NDPDisp, + nudDisp: opts.NUDDisp, opaqueIIDOpts: opts.OpaqueIIDOpts, tempIIDSeed: opts.TempIIDSeed, forwarder: newForwardQueue(), @@ -1284,9 +1302,9 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n s.mu.RLock() defer s.mu.RUnlock() - isBroadcast := remoteAddr == header.IPv4Broadcast + isLocalBroadcast := remoteAddr == header.IPv4Broadcast isMulticast := header.IsV4MulticastAddress(remoteAddr) || header.IsV6MulticastAddress(remoteAddr) - needRoute := !(isBroadcast || isMulticast || header.IsV6LinkLocalAddress(remoteAddr)) + needRoute := !(isLocalBroadcast || isMulticast || header.IsV6LinkLocalAddress(remoteAddr)) if id != 0 && !needRoute { if nic, ok := s.nics[id]; ok && nic.enabled() { if ref := s.getRefEP(nic, localAddr, remoteAddr, netProto); ref != nil { @@ -1307,9 +1325,16 @@ func (s *Stack) FindRoute(id tcpip.NICID, localAddr, remoteAddr tcpip.Address, n } r := makeRoute(netProto, ref.ep.ID().LocalAddress, remoteAddr, nic.linkEP.LinkAddress(), ref, s.handleLocal && !nic.isLoopback(), multicastLoop && !nic.isLoopback()) - if needRoute { - r.NextHop = route.Gateway + r.directedBroadcast = route.Destination.IsBroadcast(remoteAddr) + + if len(route.Gateway) > 0 { + if needRoute { + r.NextHop = route.Gateway + } + } else if r.directedBroadcast { + r.RemoteLinkAddress = header.EthernetBroadcastAddress } + return r, nil } } @@ -1862,10 +1887,38 @@ func (s *Stack) SetNDPConfigurations(id tcpip.NICID, c NDPConfigurations) *tcpip } nic.setNDPConfigs(c) - return nil } +// NUDConfigurations gets the per-interface NUD configurations. +func (s *Stack) NUDConfigurations(id tcpip.NICID) (NUDConfigurations, *tcpip.Error) { + s.mu.RLock() + nic, ok := s.nics[id] + s.mu.RUnlock() + + if !ok { + return NUDConfigurations{}, tcpip.ErrUnknownNICID + } + + return nic.NUDConfigs() +} + +// SetNUDConfigurations sets the per-interface NUD configurations. +// +// Note, if c contains invalid NUD configuration values, it will be fixed to +// use default values for the erroneous values. +func (s *Stack) SetNUDConfigurations(id tcpip.NICID, c NUDConfigurations) *tcpip.Error { + s.mu.RLock() + nic, ok := s.nics[id] + s.mu.RUnlock() + + if !ok { + return tcpip.ErrUnknownNICID + } + + return nic.setNUDConfigs(c) +} + // HandleNDPRA provides a NIC with ID id a validated NDP Router Advertisement // message that it needs to handle. func (s *Stack) HandleNDPRA(id tcpip.NICID, ip tcpip.Address, ra header.NDPRouterAdvert) *tcpip.Error { diff --git a/pkg/tcpip/stack/stack_test.go b/pkg/tcpip/stack/stack_test.go index 101ca2206..f22062889 100644 --- a/pkg/tcpip/stack/stack_test.go +++ b/pkg/tcpip/stack/stack_test.go @@ -27,6 +27,7 @@ import ( "time" "github.com/google/go-cmp/cmp" + "github.com/google/go-cmp/cmp/cmpopts" "gvisor.dev/gvisor/pkg/rand" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -3418,3 +3419,225 @@ func TestStackSendBufferSizeOption(t *testing.T) { }) } } + +func TestOutgoingSubnetBroadcast(t *testing.T) { + const ( + unspecifiedNICID = 0 + nicID1 = 1 + ) + + defaultAddr := tcpip.AddressWithPrefix{ + Address: header.IPv4Any, + PrefixLen: 0, + } + defaultSubnet := defaultAddr.Subnet() + ipv4Addr := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 24, + } + ipv4Subnet := ipv4Addr.Subnet() + ipv4SubnetBcast := ipv4Subnet.Broadcast() + ipv4Gateway := tcpip.Address("\xc0\xa8\x01\x01") + ipv4AddrPrefix31 := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 31, + } + ipv4Subnet31 := ipv4AddrPrefix31.Subnet() + ipv4Subnet31Bcast := ipv4Subnet31.Broadcast() + ipv4AddrPrefix32 := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 32, + } + ipv4Subnet32 := ipv4AddrPrefix32.Subnet() + ipv4Subnet32Bcast := ipv4Subnet32.Broadcast() + ipv6Addr := tcpip.AddressWithPrefix{ + Address: "\x20\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01", + PrefixLen: 64, + } + ipv6Subnet := ipv6Addr.Subnet() + ipv6SubnetBcast := ipv6Subnet.Broadcast() + remNetAddr := tcpip.AddressWithPrefix{ + Address: "\x64\x0a\x7b\x18", + PrefixLen: 24, + } + remNetSubnet := remNetAddr.Subnet() + remNetSubnetBcast := remNetSubnet.Broadcast() + + tests := []struct { + name string + nicAddr tcpip.ProtocolAddress + routes []tcpip.Route + remoteAddr tcpip.Address + expectedRoute stack.Route + }{ + // Broadcast to a locally attached subnet populates the broadcast MAC. + { + name: "IPv4 Broadcast to local subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet, + NIC: nicID1, + }, + }, + remoteAddr: ipv4SubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4Addr.Address, + RemoteAddress: ipv4SubnetBcast, + RemoteLinkAddress: header.EthernetBroadcastAddress, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to a locally attached /31 subnet does not populate the + // broadcast MAC. + { + name: "IPv4 Broadcast to local /31 subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4AddrPrefix31, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet31, + NIC: nicID1, + }, + }, + remoteAddr: ipv4Subnet31Bcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4AddrPrefix31.Address, + RemoteAddress: ipv4Subnet31Bcast, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to a locally attached /32 subnet does not populate the + // broadcast MAC. + { + name: "IPv4 Broadcast to local /32 subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4AddrPrefix32, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet32, + NIC: nicID1, + }, + }, + remoteAddr: ipv4Subnet32Bcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4AddrPrefix32.Address, + RemoteAddress: ipv4Subnet32Bcast, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // IPv6 has no notion of a broadcast. + { + name: "IPv6 'Broadcast' to local subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: ipv6Addr, + }, + routes: []tcpip.Route{ + { + Destination: ipv6Subnet, + NIC: nicID1, + }, + }, + remoteAddr: ipv6SubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv6Addr.Address, + RemoteAddress: ipv6SubnetBcast, + NetProto: header.IPv6ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to a remote subnet in the route table is send to the next-hop + // gateway. + { + name: "IPv4 Broadcast to remote subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: remNetSubnet, + Gateway: ipv4Gateway, + NIC: nicID1, + }, + }, + remoteAddr: remNetSubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4Addr.Address, + RemoteAddress: remNetSubnetBcast, + NextHop: ipv4Gateway, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + // Broadcast to an unknown subnet follows the default route. Note that this + // is essentially just routing an unknown destination IP, because w/o any + // subnet prefix information a subnet broadcast address is just a normal IP. + { + name: "IPv4 Broadcast to unknown subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: defaultSubnet, + Gateway: ipv4Gateway, + NIC: nicID1, + }, + }, + remoteAddr: remNetSubnetBcast, + expectedRoute: stack.Route{ + LocalAddress: ipv4Addr.Address, + RemoteAddress: remNetSubnetBcast, + NextHop: ipv4Gateway, + NetProto: header.IPv4ProtocolNumber, + Loop: stack.PacketOut, + }, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol()}, + }) + ep := channel.New(0, defaultMTU, "") + if err := s.CreateNIC(nicID1, ep); err != nil { + t.Fatalf("CreateNIC(%d, _): %s", nicID1, err) + } + if err := s.AddProtocolAddress(nicID1, test.nicAddr); err != nil { + t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID1, test.nicAddr, err) + } + + s.SetRouteTable(test.routes) + + var netProto tcpip.NetworkProtocolNumber + switch l := len(test.remoteAddr); l { + case header.IPv4AddressSize: + netProto = header.IPv4ProtocolNumber + case header.IPv6AddressSize: + netProto = header.IPv6ProtocolNumber + default: + t.Fatalf("got unexpected address length = %d bytes", l) + } + + if r, err := s.FindRoute(unspecifiedNICID, "" /* localAddr */, test.remoteAddr, netProto, false /* multicastLoop */); err != nil { + t.Fatalf("FindRoute(%d, '', %s, %d): %s", unspecifiedNICID, test.remoteAddr, netProto, err) + } else if diff := cmp.Diff(r, test.expectedRoute, cmpopts.IgnoreUnexported(r)); diff != "" { + t.Errorf("route mismatch (-want +got):\n%s", diff) + } + }) + } +} diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index 21aafb0a2..45f59b60f 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -43,6 +43,9 @@ import ( "gvisor.dev/gvisor/pkg/waiter" ) +// Using header.IPv4AddressSize would cause an import cycle. +const ipv4AddressSize = 4 + // Error represents an error in the netstack error space. Using a special type // ensures that errors outside of this space are not accidentally introduced. // @@ -320,6 +323,29 @@ func (s *Subnet) Broadcast() Address { return Address(addr) } +// IsBroadcast returns true if the address is considered a broadcast address. +func (s *Subnet) IsBroadcast(address Address) bool { + // Only IPv4 supports the notion of a broadcast address. + if len(address) != ipv4AddressSize { + return false + } + + // Normally, we would just compare address with the subnet's broadcast + // address but there is an exception where a simple comparison is not + // correct. This exception is for /31 and /32 IPv4 subnets where all + // addresses are considered valid host addresses. + // + // For /31 subnets, the case is easy. RFC 3021 Section 2.1 states that + // both addresses in a /31 subnet "MUST be interpreted as host addresses." + // + // For /32, the case is a bit more vague. RFC 3021 makes no mention of /32 + // subnets. However, the same reasoning applies - if an exception is not + // made, then there do not exist any host addresses in a /32 subnet. RFC + // 4632 Section 3.1 also vaguely implies this interpretation by referring + // to addresses in /32 subnets as "host routes." + return s.Prefix() <= 30 && s.Broadcast() == address +} + // Equal returns true if s equals o. // // Needed to use cmp.Equal on Subnet as its fields are unexported. @@ -928,6 +954,10 @@ type DefaultTTLOption uint8 // classic BPF filter on a given endpoint. type SocketDetachFilterOption int +// OriginalDestinationOption is used to get the original destination address +// and port of a redirected packet. +type OriginalDestinationOption FullAddress + // IPPacketInfo is the message structure for IP_PKTINFO. // // +stateify savable diff --git a/pkg/tcpip/transport/tcp/connect.go b/pkg/tcpip/transport/tcp/connect.go index 1798510bc..6e5e55b6f 100644 --- a/pkg/tcpip/transport/tcp/connect.go +++ b/pkg/tcpip/transport/tcp/connect.go @@ -1024,14 +1024,19 @@ func (e *endpoint) transitionToStateEstablishedLocked(h *handshake) { // delivered to this endpoint from the demuxer when the endpoint // is transitioned to StateClose. func (e *endpoint) transitionToStateCloseLocked() { - if e.EndpointState() == StateClose { + s := e.EndpointState() + if s == StateClose { return } + + if s.connected() { + e.stack.Stats().TCP.CurrentConnected.Decrement() + e.stack.Stats().TCP.EstablishedClosed.Increment() + } + // Mark the endpoint as fully closed for reads/writes. e.cleanupLocked() e.setEndpointState(StateClose) - e.stack.Stats().TCP.CurrentConnected.Decrement() - e.stack.Stats().TCP.EstablishedClosed.Increment() } // tryDeliverSegmentFromClosedEndpoint attempts to deliver the parsed diff --git a/pkg/tcpip/transport/tcp/endpoint.go b/pkg/tcpip/transport/tcp/endpoint.go index 0f7487963..682687ebe 100644 --- a/pkg/tcpip/transport/tcp/endpoint.go +++ b/pkg/tcpip/transport/tcp/endpoint.go @@ -2017,6 +2017,17 @@ func (e *endpoint) GetSockOpt(opt interface{}) *tcpip.Error { *o = tcpip.TCPDeferAcceptOption(e.deferAccept) e.UnlockUser() + case *tcpip.OriginalDestinationOption: + ipt := e.stack.IPTables() + addr, port, err := ipt.OriginalDst(e.ID) + if err != nil { + return err + } + *o = tcpip.OriginalDestinationOption{ + Addr: addr, + Port: port, + } + default: return tcpip.ErrUnknownProtocolOption } diff --git a/pkg/tcpip/transport/tcp/protocol.go b/pkg/tcpip/transport/tcp/protocol.go index 5d6174a59..b34e47bbd 100644 --- a/pkg/tcpip/transport/tcp/protocol.go +++ b/pkg/tcpip/transport/tcp/protocol.go @@ -49,7 +49,7 @@ const ( // DefaultReceiveBufferSize is the default size of the receive buffer // for an endpoint. - DefaultReceiveBufferSize = 32 << 10 // 32KB + DefaultReceiveBufferSize = 1 << 20 // 1MB // MaxBufferSize is the largest size a receive/send buffer can grow to. MaxBufferSize = 4 << 20 // 4MB diff --git a/pkg/tcpip/transport/tcp/tcp_test.go b/pkg/tcpip/transport/tcp/tcp_test.go index e67ec42b1..fb25b86b9 100644 --- a/pkg/tcpip/transport/tcp/tcp_test.go +++ b/pkg/tcpip/transport/tcp/tcp_test.go @@ -146,6 +146,24 @@ func TestActiveFailedConnectionAttemptIncrement(t *testing.T) { } } +func TestCloseWithoutConnect(t *testing.T) { + c := context.New(t, defaultMTU) + defer c.Cleanup() + + // Create TCP endpoint. + var err *tcpip.Error + c.EP, err = c.Stack().NewEndpoint(tcp.ProtocolNumber, ipv4.ProtocolNumber, &c.WQ) + if err != nil { + t.Fatalf("NewEndpoint failed: %s", err) + } + + c.EP.Close() + + if got := c.Stack().Stats().TCP.CurrentConnected.Value(); got != 0 { + t.Errorf("got stats.TCP.CurrentConnected.Value() = %d, want = 0", got) + } +} + func TestTCPSegmentsSentIncrement(t *testing.T) { c := context.New(t, defaultMTU) defer c.Cleanup() @@ -1276,68 +1294,91 @@ func TestConnectBindToDevice(t *testing.T) { } } -func TestRstOnSynSent(t *testing.T) { - c := context.New(t, defaultMTU) - defer c.Cleanup() +func TestSynSent(t *testing.T) { + for _, test := range []struct { + name string + reset bool + }{ + {"RstOnSynSent", true}, + {"CloseOnSynSent", false}, + } { + t.Run(test.name, func(t *testing.T) { + c := context.New(t, defaultMTU) + defer c.Cleanup() - // Create an endpoint, don't handshake because we want to interfere with the - // handshake process. - c.Create(-1) + // Create an endpoint, don't handshake because we want to interfere with the + // handshake process. + c.Create(-1) - // Start connection attempt. - waitEntry, ch := waiter.NewChannelEntry(nil) - c.WQ.EventRegister(&waitEntry, waiter.EventOut) - defer c.WQ.EventUnregister(&waitEntry) + // Start connection attempt. + waitEntry, ch := waiter.NewChannelEntry(nil) + c.WQ.EventRegister(&waitEntry, waiter.EventOut) + defer c.WQ.EventUnregister(&waitEntry) - addr := tcpip.FullAddress{Addr: context.TestAddr, Port: context.TestPort} - if err := c.EP.Connect(addr); err != tcpip.ErrConnectStarted { - t.Fatalf("got Connect(%+v) = %s, want %s", addr, err, tcpip.ErrConnectStarted) - } + addr := tcpip.FullAddress{Addr: context.TestAddr, Port: context.TestPort} + if err := c.EP.Connect(addr); err != tcpip.ErrConnectStarted { + t.Fatalf("got Connect(%+v) = %s, want %s", addr, err, tcpip.ErrConnectStarted) + } - // Receive SYN packet. - b := c.GetPacket() - checker.IPv4(t, b, - checker.TCP( - checker.DstPort(context.TestPort), - checker.TCPFlags(header.TCPFlagSyn), - ), - ) + // Receive SYN packet. + b := c.GetPacket() + checker.IPv4(t, b, + checker.TCP( + checker.DstPort(context.TestPort), + checker.TCPFlags(header.TCPFlagSyn), + ), + ) - // Ensure that we've reached SynSent state - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateSynSent; got != want { - t.Fatalf("got State() = %s, want %s", got, want) - } - tcpHdr := header.TCP(header.IPv4(b).Payload()) - c.IRS = seqnum.Value(tcpHdr.SequenceNumber()) + if got, want := tcp.EndpointState(c.EP.State()), tcp.StateSynSent; got != want { + t.Fatalf("got State() = %s, want %s", got, want) + } + tcpHdr := header.TCP(header.IPv4(b).Payload()) + c.IRS = seqnum.Value(tcpHdr.SequenceNumber()) - // Send a packet with a proper ACK and a RST flag to cause the socket - // to Error and close out - iss := seqnum.Value(789) - rcvWnd := seqnum.Size(30000) - c.SendPacket(nil, &context.Headers{ - SrcPort: tcpHdr.DestinationPort(), - DstPort: tcpHdr.SourcePort(), - Flags: header.TCPFlagRst | header.TCPFlagAck, - SeqNum: iss, - AckNum: c.IRS.Add(1), - RcvWnd: rcvWnd, - TCPOpts: nil, - }) + if test.reset { + // Send a packet with a proper ACK and a RST flag to cause the socket + // to error and close out. + iss := seqnum.Value(789) + rcvWnd := seqnum.Size(30000) + c.SendPacket(nil, &context.Headers{ + SrcPort: tcpHdr.DestinationPort(), + DstPort: tcpHdr.SourcePort(), + Flags: header.TCPFlagRst | header.TCPFlagAck, + SeqNum: iss, + AckNum: c.IRS.Add(1), + RcvWnd: rcvWnd, + TCPOpts: nil, + }) + } else { + c.EP.Close() + } - // Wait for receive to be notified. - select { - case <-ch: - case <-time.After(3 * time.Second): - t.Fatal("timed out waiting for packet to arrive") - } + // Wait for receive to be notified. + select { + case <-ch: + case <-time.After(3 * time.Second): + t.Fatal("timed out waiting for packet to arrive") + } - if _, _, err := c.EP.Read(nil); err != tcpip.ErrConnectionRefused { - t.Fatalf("got c.EP.Read(nil) = %s, want = %s", err, tcpip.ErrConnectionRefused) - } + if test.reset { + if _, _, err := c.EP.Read(nil); err != tcpip.ErrConnectionRefused { + t.Fatalf("got c.EP.Read(nil) = %s, want = %s", err, tcpip.ErrConnectionRefused) + } + } else { + if _, _, err := c.EP.Read(nil); err != tcpip.ErrAborted { + t.Fatalf("got c.EP.Read(nil) = %s, want = %s", err, tcpip.ErrAborted) + } + } - // Due to the RST the endpoint should be in an error state. - if got, want := tcp.EndpointState(c.EP.State()), tcp.StateError; got != want { - t.Fatalf("got State() = %s, want %s", got, want) + if got := c.Stack().Stats().TCP.CurrentConnected.Value(); got != 0 { + t.Errorf("got stats.TCP.CurrentConnected.Value() = %d, want = 0", got) + } + + // Due to the RST the endpoint should be in an error state. + if got, want := tcp.EndpointState(c.EP.State()), tcp.StateError; got != want { + t.Fatalf("got State() = %s, want %s", got, want) + } + }) } } diff --git a/pkg/tcpip/transport/udp/endpoint.go b/pkg/tcpip/transport/udp/endpoint.go index 6e692da07..b7d735889 100644 --- a/pkg/tcpip/transport/udp/endpoint.go +++ b/pkg/tcpip/transport/udp/endpoint.go @@ -483,10 +483,6 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c nicID = e.BindNICID } - if to.Addr == header.IPv4Broadcast && !e.broadcast { - return 0, nil, tcpip.ErrBroadcastDisabled - } - dst, netProto, err := e.checkV4MappedLocked(*to) if err != nil { return 0, nil, err @@ -503,6 +499,10 @@ func (e *endpoint) write(p tcpip.Payloader, opts tcpip.WriteOptions) (int64, <-c resolve = route.Resolve } + if !e.broadcast && route.IsBroadcast() { + return 0, nil, tcpip.ErrBroadcastDisabled + } + if route.IsResolutionRequired() { if ch, err := resolve(nil); err != nil { if err == tcpip.ErrWouldBlock { diff --git a/pkg/tcpip/transport/udp/udp_test.go b/pkg/tcpip/transport/udp/udp_test.go index 90781cf49..66e8911c8 100644 --- a/pkg/tcpip/transport/udp/udp_test.go +++ b/pkg/tcpip/transport/udp/udp_test.go @@ -2142,3 +2142,192 @@ func (c *testContext) checkEndpointReadStats(incr uint64, want tcpip.TransportEn c.t.Errorf("Endpoint stats not matching for error %s got %+v want %+v", err, got, want) } } + +func TestOutgoingSubnetBroadcast(t *testing.T) { + const nicID1 = 1 + + ipv4Addr := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 24, + } + ipv4Subnet := ipv4Addr.Subnet() + ipv4SubnetBcast := ipv4Subnet.Broadcast() + ipv4Gateway := tcpip.Address("\xc0\xa8\x01\x01") + ipv4AddrPrefix31 := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 31, + } + ipv4Subnet31 := ipv4AddrPrefix31.Subnet() + ipv4Subnet31Bcast := ipv4Subnet31.Broadcast() + ipv4AddrPrefix32 := tcpip.AddressWithPrefix{ + Address: "\xc0\xa8\x01\x3a", + PrefixLen: 32, + } + ipv4Subnet32 := ipv4AddrPrefix32.Subnet() + ipv4Subnet32Bcast := ipv4Subnet32.Broadcast() + ipv6Addr := tcpip.AddressWithPrefix{ + Address: "\x20\x0a\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01", + PrefixLen: 64, + } + ipv6Subnet := ipv6Addr.Subnet() + ipv6SubnetBcast := ipv6Subnet.Broadcast() + remNetAddr := tcpip.AddressWithPrefix{ + Address: "\x64\x0a\x7b\x18", + PrefixLen: 24, + } + remNetSubnet := remNetAddr.Subnet() + remNetSubnetBcast := remNetSubnet.Broadcast() + + tests := []struct { + name string + nicAddr tcpip.ProtocolAddress + routes []tcpip.Route + remoteAddr tcpip.Address + requiresBroadcastOpt bool + }{ + { + name: "IPv4 Broadcast to local subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet, + NIC: nicID1, + }, + }, + remoteAddr: ipv4SubnetBcast, + requiresBroadcastOpt: true, + }, + { + name: "IPv4 Broadcast to local /31 subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4AddrPrefix31, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet31, + NIC: nicID1, + }, + }, + remoteAddr: ipv4Subnet31Bcast, + requiresBroadcastOpt: false, + }, + { + name: "IPv4 Broadcast to local /32 subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4AddrPrefix32, + }, + routes: []tcpip.Route{ + { + Destination: ipv4Subnet32, + NIC: nicID1, + }, + }, + remoteAddr: ipv4Subnet32Bcast, + requiresBroadcastOpt: false, + }, + // IPv6 has no notion of a broadcast. + { + name: "IPv6 'Broadcast' to local subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv6ProtocolNumber, + AddressWithPrefix: ipv6Addr, + }, + routes: []tcpip.Route{ + { + Destination: ipv6Subnet, + NIC: nicID1, + }, + }, + remoteAddr: ipv6SubnetBcast, + requiresBroadcastOpt: false, + }, + { + name: "IPv4 Broadcast to remote subnet", + nicAddr: tcpip.ProtocolAddress{ + Protocol: header.IPv4ProtocolNumber, + AddressWithPrefix: ipv4Addr, + }, + routes: []tcpip.Route{ + { + Destination: remNetSubnet, + Gateway: ipv4Gateway, + NIC: nicID1, + }, + }, + remoteAddr: remNetSubnetBcast, + requiresBroadcastOpt: true, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocol{ipv4.NewProtocol(), ipv6.NewProtocol()}, + + TransportProtocols: []stack.TransportProtocol{udp.NewProtocol()}, + }) + e := channel.New(0, defaultMTU, "") + if err := s.CreateNIC(nicID1, e); err != nil { + t.Fatalf("CreateNIC(%d, _): %s", nicID1, err) + } + if err := s.AddProtocolAddress(nicID1, test.nicAddr); err != nil { + t.Fatalf("AddProtocolAddress(%d, %+v): %s", nicID1, test.nicAddr, err) + } + + s.SetRouteTable(test.routes) + + var netProto tcpip.NetworkProtocolNumber + switch l := len(test.remoteAddr); l { + case header.IPv4AddressSize: + netProto = header.IPv4ProtocolNumber + case header.IPv6AddressSize: + netProto = header.IPv6ProtocolNumber + default: + t.Fatalf("got unexpected address length = %d bytes", l) + } + + wq := waiter.Queue{} + ep, err := s.NewEndpoint(udp.ProtocolNumber, netProto, &wq) + if err != nil { + t.Fatalf("NewEndpoint(%d, %d, _): %s", udp.ProtocolNumber, netProto, err) + } + defer ep.Close() + + data := tcpip.SlicePayload([]byte{1, 2, 3, 4}) + to := tcpip.FullAddress{ + Addr: test.remoteAddr, + Port: 80, + } + opts := tcpip.WriteOptions{To: &to} + expectedErrWithoutBcastOpt := tcpip.ErrBroadcastDisabled + if !test.requiresBroadcastOpt { + expectedErrWithoutBcastOpt = nil + } + + if n, _, err := ep.Write(data, opts); err != expectedErrWithoutBcastOpt { + t.Fatalf("got ep.Write(_, _) = (%d, _, %v), want = (_, _, %v)", n, err, expectedErrWithoutBcastOpt) + } + + if err := ep.SetSockOptBool(tcpip.BroadcastOption, true); err != nil { + t.Fatalf("got SetSockOptBool(BroadcastOption, true): %s", err) + } + + if n, _, err := ep.Write(data, opts); err != nil { + t.Fatalf("got ep.Write(_, _) = (%d, _, %s), want = (_, _, nil)", n, err) + } + + if err := ep.SetSockOptBool(tcpip.BroadcastOption, false); err != nil { + t.Fatalf("got SetSockOptBool(BroadcastOption, false): %s", err) + } + + if n, _, err := ep.Write(data, opts); err != expectedErrWithoutBcastOpt { + t.Fatalf("got ep.Write(_, _) = (%d, _, %v), want = (_, _, %v)", n, err, expectedErrWithoutBcastOpt) + } + }) + } +} |