diff options
Diffstat (limited to 'pkg/tcpip/header')
| -rw-r--r-- | pkg/tcpip/header/BUILD | 20 | ||||
| -rw-r--r-- | pkg/tcpip/header/arp.go | 77 | ||||
| -rw-r--r-- | pkg/tcpip/header/checksum.go | 133 | ||||
| -rw-r--r-- | pkg/tcpip/header/checksum_test.go | 62 | ||||
| -rw-r--r-- | pkg/tcpip/header/eth.go | 45 | ||||
| -rw-r--r-- | pkg/tcpip/header/eth_test.go | 34 | ||||
| -rw-r--r-- | pkg/tcpip/header/icmpv4.go | 16 | ||||
| -rw-r--r-- | pkg/tcpip/header/icmpv6.go | 38 | ||||
| -rw-r--r-- | pkg/tcpip/header/ipv4.go | 24 | ||||
| -rw-r--r-- | pkg/tcpip/header/ipv6.go | 240 | ||||
| -rw-r--r-- | pkg/tcpip/header/ipv6_extension_headers.go | 551 | ||||
| -rw-r--r-- | pkg/tcpip/header/ipv6_extension_headers_test.go | 992 | ||||
| -rw-r--r-- | pkg/tcpip/header/ipv6_test.go | 417 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_options.go | 631 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_router_solicit.go | 36 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndp_test.go | 1315 | ||||
| -rw-r--r-- | pkg/tcpip/header/ndpoptionidentifier_string.go | 50 | ||||
| -rw-r--r-- | pkg/tcpip/header/tcp.go | 91 | ||||
| -rw-r--r-- | pkg/tcpip/header/udp.go | 5 |
19 files changed, 4633 insertions, 144 deletions
diff --git a/pkg/tcpip/header/BUILD b/pkg/tcpip/header/BUILD index a3485b35c..d87797617 100644 --- a/pkg/tcpip/header/BUILD +++ b/pkg/tcpip/header/BUILD @@ -1,5 +1,4 @@ -load("@io_bazel_rules_go//go:def.bzl", "go_test") -load("//tools/go_stateify:defs.bzl", "go_library") +load("//tools:defs.bzl", "go_library", "go_test") package(licenses = ["notice"]) @@ -15,15 +14,17 @@ go_library( "interfaces.go", "ipv4.go", "ipv6.go", + "ipv6_extension_headers.go", "ipv6_fragment.go", "ndp_neighbor_advert.go", "ndp_neighbor_solicit.go", "ndp_options.go", "ndp_router_advert.go", + "ndp_router_solicit.go", + "ndpoptionidentifier_string.go", "tcp.go", "udp.go", ], - importpath = "gvisor.dev/gvisor/pkg/tcpip/header", visibility = ["//visibility:public"], deps = [ "//pkg/tcpip", @@ -38,12 +39,16 @@ go_test( size = "small", srcs = [ "checksum_test.go", + "ipv6_test.go", "ipversion_test.go", "tcp_test.go", ], deps = [ ":header", + "//pkg/rand", + "//pkg/tcpip", "//pkg/tcpip/buffer", + "@com_github_google_go_cmp//cmp:go_default_library", ], ) @@ -52,8 +57,13 @@ go_test( size = "small", srcs = [ "eth_test.go", + "ipv6_extension_headers_test.go", "ndp_test.go", ], - embed = [":header"], - deps = ["//pkg/tcpip"], + library = ":header", + deps = [ + "//pkg/tcpip", + "//pkg/tcpip/buffer", + "@com_github_google_go_cmp//cmp:go_default_library", + ], ) diff --git a/pkg/tcpip/header/arp.go b/pkg/tcpip/header/arp.go index 718a4720a..83189676e 100644 --- a/pkg/tcpip/header/arp.go +++ b/pkg/tcpip/header/arp.go @@ -14,14 +14,33 @@ package header -import "gvisor.dev/gvisor/pkg/tcpip" +import ( + "encoding/binary" + + "gvisor.dev/gvisor/pkg/tcpip" +) const ( // ARPProtocolNumber is the ARP network protocol number. ARPProtocolNumber tcpip.NetworkProtocolNumber = 0x0806 // ARPSize is the size of an IPv4-over-Ethernet ARP packet. - ARPSize = 2 + 2 + 1 + 1 + 2 + 2*6 + 2*4 + ARPSize = 28 +) + +// ARPHardwareType is the hardware type for LinkEndpoint in an ARP header. +type ARPHardwareType uint16 + +// Typical ARP HardwareType values. Some of the constants have to be specific +// values as they are egressed on the wire in the HTYPE field of an ARP header. +const ( + ARPHardwareNone ARPHardwareType = 0 + // ARPHardwareEther specifically is the HTYPE for Ethernet as specified + // in the IANA list here: + // + // https://www.iana.org/assignments/arp-parameters/arp-parameters.xhtml#arp-parameters-2 + ARPHardwareEther ARPHardwareType = 1 + ARPHardwareLoopback ARPHardwareType = 2 ) // ARPOp is an ARP opcode. @@ -36,54 +55,64 @@ const ( // ARP is an ARP packet stored in a byte array as described in RFC 826. type ARP []byte -func (a ARP) hardwareAddressSpace() uint16 { return uint16(a[0])<<8 | uint16(a[1]) } -func (a ARP) protocolAddressSpace() uint16 { return uint16(a[2])<<8 | uint16(a[3]) } -func (a ARP) hardwareAddressSize() int { return int(a[4]) } -func (a ARP) protocolAddressSize() int { return int(a[5]) } +const ( + hTypeOffset = 0 + protocolOffset = 2 + haAddressSizeOffset = 4 + protoAddressSizeOffset = 5 + opCodeOffset = 6 + senderHAAddressOffset = 8 + senderProtocolAddressOffset = senderHAAddressOffset + EthernetAddressSize + targetHAAddressOffset = senderProtocolAddressOffset + IPv4AddressSize + targetProtocolAddressOffset = targetHAAddressOffset + EthernetAddressSize +) + +func (a ARP) hardwareAddressType() ARPHardwareType { + return ARPHardwareType(binary.BigEndian.Uint16(a[hTypeOffset:])) +} + +func (a ARP) protocolAddressSpace() uint16 { return binary.BigEndian.Uint16(a[protocolOffset:]) } +func (a ARP) hardwareAddressSize() int { return int(a[haAddressSizeOffset]) } +func (a ARP) protocolAddressSize() int { return int(a[protoAddressSizeOffset]) } // Op is the ARP opcode. -func (a ARP) Op() ARPOp { return ARPOp(a[6])<<8 | ARPOp(a[7]) } +func (a ARP) Op() ARPOp { return ARPOp(binary.BigEndian.Uint16(a[opCodeOffset:])) } // SetOp sets the ARP opcode. func (a ARP) SetOp(op ARPOp) { - a[6] = uint8(op >> 8) - a[7] = uint8(op) + binary.BigEndian.PutUint16(a[opCodeOffset:], uint16(op)) } // SetIPv4OverEthernet configures the ARP packet for IPv4-over-Ethernet. func (a ARP) SetIPv4OverEthernet() { - a[0], a[1] = 0, 1 // htypeEthernet - a[2], a[3] = 0x08, 0x00 // IPv4ProtocolNumber - a[4] = 6 // macSize - a[5] = uint8(IPv4AddressSize) + binary.BigEndian.PutUint16(a[hTypeOffset:], uint16(ARPHardwareEther)) + binary.BigEndian.PutUint16(a[protocolOffset:], uint16(IPv4ProtocolNumber)) + a[haAddressSizeOffset] = EthernetAddressSize + a[protoAddressSizeOffset] = uint8(IPv4AddressSize) } // HardwareAddressSender is the link address of the sender. // It is a view on to the ARP packet so it can be used to set the value. func (a ARP) HardwareAddressSender() []byte { - const s = 8 - return a[s : s+6] + return a[senderHAAddressOffset : senderHAAddressOffset+EthernetAddressSize] } // ProtocolAddressSender is the protocol address of the sender. // It is a view on to the ARP packet so it can be used to set the value. func (a ARP) ProtocolAddressSender() []byte { - const s = 8 + 6 - return a[s : s+4] + return a[senderProtocolAddressOffset : senderProtocolAddressOffset+IPv4AddressSize] } // HardwareAddressTarget is the link address of the target. // It is a view on to the ARP packet so it can be used to set the value. func (a ARP) HardwareAddressTarget() []byte { - const s = 8 + 6 + 4 - return a[s : s+6] + return a[targetHAAddressOffset : targetHAAddressOffset+EthernetAddressSize] } // ProtocolAddressTarget is the protocol address of the target. // It is a view on to the ARP packet so it can be used to set the value. func (a ARP) ProtocolAddressTarget() []byte { - const s = 8 + 6 + 4 + 6 - return a[s : s+4] + return a[targetProtocolAddressOffset : targetProtocolAddressOffset+IPv4AddressSize] } // IsValid reports whether this is an ARP packet for IPv4 over Ethernet. @@ -91,10 +120,8 @@ func (a ARP) IsValid() bool { if len(a) < ARPSize { return false } - const htypeEthernet = 1 - const macSize = 6 - return a.hardwareAddressSpace() == htypeEthernet && + return a.hardwareAddressType() == ARPHardwareEther && a.protocolAddressSpace() == uint16(IPv4ProtocolNumber) && - a.hardwareAddressSize() == macSize && + a.hardwareAddressSize() == EthernetAddressSize && a.protocolAddressSize() == IPv4AddressSize } diff --git a/pkg/tcpip/header/checksum.go b/pkg/tcpip/header/checksum.go index 9749c7f4d..14a4b2b44 100644 --- a/pkg/tcpip/header/checksum.go +++ b/pkg/tcpip/header/checksum.go @@ -45,12 +45,139 @@ func calculateChecksum(buf []byte, odd bool, initial uint32) (uint16, bool) { return ChecksumCombine(uint16(v), uint16(v>>16)), odd } +func unrolledCalculateChecksum(buf []byte, odd bool, initial uint32) (uint16, bool) { + v := initial + + if odd { + v += uint32(buf[0]) + buf = buf[1:] + } + + l := len(buf) + odd = l&1 != 0 + if odd { + l-- + v += uint32(buf[l]) << 8 + } + for (l - 64) >= 0 { + i := 0 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + i += 16 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + i += 16 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + i += 16 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + buf = buf[64:] + l = l - 64 + } + if (l - 32) >= 0 { + i := 0 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + i += 16 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + buf = buf[32:] + l = l - 32 + } + if (l - 16) >= 0 { + i := 0 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + v += (uint32(buf[i+8]) << 8) + uint32(buf[i+9]) + v += (uint32(buf[i+10]) << 8) + uint32(buf[i+11]) + v += (uint32(buf[i+12]) << 8) + uint32(buf[i+13]) + v += (uint32(buf[i+14]) << 8) + uint32(buf[i+15]) + buf = buf[16:] + l = l - 16 + } + if (l - 8) >= 0 { + i := 0 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + v += (uint32(buf[i+4]) << 8) + uint32(buf[i+5]) + v += (uint32(buf[i+6]) << 8) + uint32(buf[i+7]) + buf = buf[8:] + l = l - 8 + } + if (l - 4) >= 0 { + i := 0 + v += (uint32(buf[i]) << 8) + uint32(buf[i+1]) + v += (uint32(buf[i+2]) << 8) + uint32(buf[i+3]) + buf = buf[4:] + l = l - 4 + } + + // At this point since l was even before we started unrolling + // there can be only two bytes left to add. + if l != 0 { + v += (uint32(buf[0]) << 8) + uint32(buf[1]) + } + + return ChecksumCombine(uint16(v), uint16(v>>16)), odd +} + +// ChecksumOld calculates the checksum (as defined in RFC 1071) of the bytes in +// the given byte array. This function uses a non-optimized implementation. Its +// only retained for reference and to use as a benchmark/test. Most code should +// use the header.Checksum function. +// +// The initial checksum must have been computed on an even number of bytes. +func ChecksumOld(buf []byte, initial uint16) uint16 { + s, _ := calculateChecksum(buf, false, uint32(initial)) + return s +} + // Checksum calculates the checksum (as defined in RFC 1071) of the bytes in the -// given byte array. +// given byte array. This function uses an optimized unrolled version of the +// checksum algorithm. // // The initial checksum must have been computed on an even number of bytes. func Checksum(buf []byte, initial uint16) uint16 { - s, _ := calculateChecksum(buf, false, uint32(initial)) + s, _ := unrolledCalculateChecksum(buf, false, uint32(initial)) return s } @@ -86,7 +213,7 @@ func ChecksumVVWithOffset(vv buffer.VectorisedView, initial uint16, off int, siz } v = v[:l] - sum, odd = calculateChecksum(v, odd, uint32(sum)) + sum, odd = unrolledCalculateChecksum(v, odd, uint32(sum)) size -= len(v) if size == 0 { diff --git a/pkg/tcpip/header/checksum_test.go b/pkg/tcpip/header/checksum_test.go index 86b466c1c..309403482 100644 --- a/pkg/tcpip/header/checksum_test.go +++ b/pkg/tcpip/header/checksum_test.go @@ -17,6 +17,8 @@ package header_test import ( + "fmt" + "math/rand" "testing" "gvisor.dev/gvisor/pkg/tcpip/buffer" @@ -107,3 +109,63 @@ func TestChecksumVVWithOffset(t *testing.T) { }) } } + +func TestChecksum(t *testing.T) { + var bufSizes = []int{0, 1, 2, 3, 4, 7, 8, 15, 16, 31, 32, 63, 64, 127, 128, 255, 256, 257, 1023, 1024} + type testCase struct { + buf []byte + initial uint16 + csumOrig uint16 + csumNew uint16 + } + testCases := make([]testCase, 100000) + // Ensure same buffer generation for test consistency. + rnd := rand.New(rand.NewSource(42)) + for i := range testCases { + testCases[i].buf = make([]byte, bufSizes[i%len(bufSizes)]) + testCases[i].initial = uint16(rnd.Intn(65536)) + rnd.Read(testCases[i].buf) + } + + for i := range testCases { + testCases[i].csumOrig = header.ChecksumOld(testCases[i].buf, testCases[i].initial) + testCases[i].csumNew = header.Checksum(testCases[i].buf, testCases[i].initial) + if got, want := testCases[i].csumNew, testCases[i].csumOrig; got != want { + t.Fatalf("new checksum for (buf = %x, initial = %d) does not match old got: %d, want: %d", testCases[i].buf, testCases[i].initial, got, want) + } + } +} + +func BenchmarkChecksum(b *testing.B) { + var bufSizes = []int{64, 128, 256, 512, 1024, 1500, 2048, 4096, 8192, 16384, 32767, 32768, 65535, 65536} + + checkSumImpls := []struct { + fn func([]byte, uint16) uint16 + name string + }{ + {header.ChecksumOld, fmt.Sprintf("checksum_old")}, + {header.Checksum, fmt.Sprintf("checksum")}, + } + + for _, csumImpl := range checkSumImpls { + // Ensure same buffer generation for test consistency. + rnd := rand.New(rand.NewSource(42)) + for _, bufSz := range bufSizes { + b.Run(fmt.Sprintf("%s_%d", csumImpl.name, bufSz), func(b *testing.B) { + tc := struct { + buf []byte + initial uint16 + csum uint16 + }{ + buf: make([]byte, bufSz), + initial: uint16(rnd.Intn(65536)), + } + rnd.Read(tc.buf) + b.ResetTimer() + for i := 0; i < b.N; i++ { + tc.csum = csumImpl.fn(tc.buf, tc.initial) + } + }) + } + } +} diff --git a/pkg/tcpip/header/eth.go b/pkg/tcpip/header/eth.go index f5d2c127f..eaface8cb 100644 --- a/pkg/tcpip/header/eth.go +++ b/pkg/tcpip/header/eth.go @@ -53,6 +53,10 @@ const ( // (all bits set to 0). unspecifiedEthernetAddress = tcpip.LinkAddress("\x00\x00\x00\x00\x00\x00") + // EthernetBroadcastAddress is an ethernet address that addresses every node + // on a local link. + EthernetBroadcastAddress = tcpip.LinkAddress("\xff\xff\xff\xff\xff\xff") + // unicastMulticastFlagMask is the mask of the least significant bit in // the first octet (in network byte order) of an ethernet address that // determines whether the ethernet address is a unicast or multicast. If @@ -134,3 +138,44 @@ func IsValidUnicastEthernetAddress(addr tcpip.LinkAddress) bool { // addr is a valid unicast ethernet address. return true } + +// EthernetAddressFromMulticastIPv4Address returns a multicast Ethernet address +// for a multicast IPv4 address. +// +// addr MUST be a multicast IPv4 address. +func EthernetAddressFromMulticastIPv4Address(addr tcpip.Address) tcpip.LinkAddress { + var linkAddrBytes [EthernetAddressSize]byte + // RFC 1112 Host Extensions for IP Multicasting + // + // 6.4. Extensions to an Ethernet Local Network Module: + // + // An IP host group address is mapped to an Ethernet multicast + // address by placing the low-order 23-bits of the IP address + // into the low-order 23 bits of the Ethernet multicast address + // 01-00-5E-00-00-00 (hex). + linkAddrBytes[0] = 0x1 + linkAddrBytes[2] = 0x5e + linkAddrBytes[3] = addr[1] & 0x7F + copy(linkAddrBytes[4:], addr[IPv4AddressSize-2:]) + return tcpip.LinkAddress(linkAddrBytes[:]) +} + +// EthernetAddressFromMulticastIPv6Address returns a multicast Ethernet address +// for a multicast IPv6 address. +// +// addr MUST be a multicast IPv6 address. +func EthernetAddressFromMulticastIPv6Address(addr tcpip.Address) tcpip.LinkAddress { + // RFC 2464 Transmission of IPv6 Packets over Ethernet Networks + // + // 7. Address Mapping -- Multicast + // + // An IPv6 packet with a multicast destination address DST, + // consisting of the sixteen octets DST[1] through DST[16], is + // transmitted to the Ethernet multicast address whose first + // two octets are the value 3333 hexadecimal and whose last + // four octets are the last four octets of DST. + linkAddrBytes := []byte(addr[IPv6AddressSize-EthernetAddressSize:]) + linkAddrBytes[0] = 0x33 + linkAddrBytes[1] = 0x33 + return tcpip.LinkAddress(linkAddrBytes[:]) +} diff --git a/pkg/tcpip/header/eth_test.go b/pkg/tcpip/header/eth_test.go index 6634c90f5..14413f2ce 100644 --- a/pkg/tcpip/header/eth_test.go +++ b/pkg/tcpip/header/eth_test.go @@ -66,3 +66,37 @@ func TestIsValidUnicastEthernetAddress(t *testing.T) { }) } } + +func TestEthernetAddressFromMulticastIPv4Address(t *testing.T) { + tests := []struct { + name string + addr tcpip.Address + expectedLinkAddr tcpip.LinkAddress + }{ + { + name: "IPv4 Multicast without 24th bit set", + addr: "\xe0\x7e\xdc\xba", + expectedLinkAddr: "\x01\x00\x5e\x7e\xdc\xba", + }, + { + name: "IPv4 Multicast with 24th bit set", + addr: "\xe0\xfe\xdc\xba", + expectedLinkAddr: "\x01\x00\x5e\x7e\xdc\xba", + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + if got := EthernetAddressFromMulticastIPv4Address(test.addr); got != test.expectedLinkAddr { + t.Fatalf("got EthernetAddressFromMulticastIPv4Address(%s) = %s, want = %s", test.addr, got, test.expectedLinkAddr) + } + }) + } +} + +func TestEthernetAddressFromMulticastIPv6Address(t *testing.T) { + addr := tcpip.Address("\xff\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x1a") + if got, want := EthernetAddressFromMulticastIPv6Address(addr), tcpip.LinkAddress("\x33\x33\x0d\x0e\x0f\x1a"); got != want { + t.Fatalf("got EthernetAddressFromMulticastIPv6Address(%s) = %s, want = %s", addr, got, want) + } +} diff --git a/pkg/tcpip/header/icmpv4.go b/pkg/tcpip/header/icmpv4.go index 0cac6c0a5..be03fb086 100644 --- a/pkg/tcpip/header/icmpv4.go +++ b/pkg/tcpip/header/icmpv4.go @@ -54,6 +54,9 @@ const ( // ICMPv4Type is the ICMP type field described in RFC 792. type ICMPv4Type byte +// ICMPv4Code is the ICMP code field described in RFC 792. +type ICMPv4Code byte + // Typical values of ICMPv4Type defined in RFC 792. const ( ICMPv4EchoReply ICMPv4Type = 0 @@ -69,10 +72,13 @@ const ( ICMPv4InfoReply ICMPv4Type = 16 ) -// Values for ICMP code as defined in RFC 792. +// ICMP codes for ICMPv4 Destination Unreachable messages as defined in RFC 792. const ( - ICMPv4PortUnreachable = 3 - ICMPv4FragmentationNeeded = 4 + ICMPv4TTLExceeded ICMPv4Code = 0 + ICMPv4HostUnreachable ICMPv4Code = 1 + ICMPv4ProtoUnreachable ICMPv4Code = 2 + ICMPv4PortUnreachable ICMPv4Code = 3 + ICMPv4FragmentationNeeded ICMPv4Code = 4 ) // Type is the ICMP type field. @@ -82,10 +88,10 @@ func (b ICMPv4) Type() ICMPv4Type { return ICMPv4Type(b[0]) } func (b ICMPv4) SetType(t ICMPv4Type) { b[0] = byte(t) } // Code is the ICMP code field. Its meaning depends on the value of Type. -func (b ICMPv4) Code() byte { return b[1] } +func (b ICMPv4) Code() ICMPv4Code { return ICMPv4Code(b[1]) } // SetCode sets the ICMP code field. -func (b ICMPv4) SetCode(c byte) { b[1] = c } +func (b ICMPv4) SetCode(c ICMPv4Code) { b[1] = byte(c) } // Checksum is the ICMP checksum field. func (b ICMPv4) Checksum() uint16 { diff --git a/pkg/tcpip/header/icmpv6.go b/pkg/tcpip/header/icmpv6.go index b4037b6c8..20b01d8f4 100644 --- a/pkg/tcpip/header/icmpv6.go +++ b/pkg/tcpip/header/icmpv6.go @@ -52,7 +52,7 @@ const ( // ICMPv6NeighborAdvertSize is size of a neighbor advertisement // including the NDP Target Link Layer option for an Ethernet // address. - ICMPv6NeighborAdvertSize = ICMPv6HeaderSize + NDPNAMinimumSize + ndpTargetEthernetLinkLayerAddressSize + ICMPv6NeighborAdvertSize = ICMPv6HeaderSize + NDPNAMinimumSize + NDPLinkLayerAddressSize // ICMPv6EchoMinimumSize is the minimum size of a valid ICMP echo packet. ICMPv6EchoMinimumSize = 8 @@ -92,7 +92,6 @@ const ( // ICMPv6Type is the ICMP type field described in RFC 4443 and friends. type ICMPv6Type byte -// Typical values of ICMPv6Type defined in RFC 4443. const ( ICMPv6DstUnreachable ICMPv6Type = 1 ICMPv6PacketTooBig ICMPv6Type = 2 @@ -110,11 +109,38 @@ const ( ICMPv6RedirectMsg ICMPv6Type = 137 ) -// Values for ICMP code as defined in RFC 4443. +// ICMPv6Code is the ICMP code field described in RFC 4443. +type ICMPv6Code byte + +// ICMP codes used with Destination Unreachable (Type 1). As per RFC 4443 +// section 3.1. +const ( + ICMPv6NetworkUnreachable ICMPv6Code = 0 + ICMPv6Prohibited ICMPv6Code = 1 + ICMPv6BeyondScope ICMPv6Code = 2 + ICMPv6AddressUnreachable ICMPv6Code = 3 + ICMPv6PortUnreachable ICMPv6Code = 4 + ICMPv6Policy ICMPv6Code = 5 + ICMPv6RejectRoute ICMPv6Code = 6 +) + +// ICMP codes used with Time Exceeded (Type 3). As per RFC 4443 section 3.3. const ( - ICMPv6PortUnreachable = 4 + ICMPv6HopLimitExceeded ICMPv6Code = 0 + ICMPv6ReassemblyTimeout ICMPv6Code = 1 ) +// ICMP codes used with Parameter Problem (Type 4). As per RFC 4443 section 3.4. +const ( + ICMPv6ErroneousHeader ICMPv6Code = 0 + ICMPv6UnknownHeader ICMPv6Code = 1 + ICMPv6UnknownOption ICMPv6Code = 2 +) + +// ICMPv6UnusedCode is the code value used with ICMPv6 messages which don't use +// the code field. (Types not mentioned above.) +const ICMPv6UnusedCode ICMPv6Code = 0 + // Type is the ICMP type field. func (b ICMPv6) Type() ICMPv6Type { return ICMPv6Type(b[0]) } @@ -122,10 +148,10 @@ func (b ICMPv6) Type() ICMPv6Type { return ICMPv6Type(b[0]) } func (b ICMPv6) SetType(t ICMPv6Type) { b[0] = byte(t) } // Code is the ICMP code field. Its meaning depends on the value of Type. -func (b ICMPv6) Code() byte { return b[1] } +func (b ICMPv6) Code() ICMPv6Code { return ICMPv6Code(b[1]) } // SetCode sets the ICMP code field. -func (b ICMPv6) SetCode(c byte) { b[1] = c } +func (b ICMPv6) SetCode(c ICMPv6Code) { b[1] = byte(c) } // Checksum is the ICMP checksum field. func (b ICMPv6) Checksum() uint16 { diff --git a/pkg/tcpip/header/ipv4.go b/pkg/tcpip/header/ipv4.go index e5360e7c1..680eafd16 100644 --- a/pkg/tcpip/header/ipv4.go +++ b/pkg/tcpip/header/ipv4.go @@ -38,7 +38,8 @@ const ( // IPv4Fields contains the fields of an IPv4 packet. It is used to describe the // fields of a packet that needs to be encoded. type IPv4Fields struct { - // IHL is the "internet header length" field of an IPv4 packet. + // IHL is the "internet header length" field of an IPv4 packet. The value + // is in bytes. IHL uint8 // TOS is the "type of service" field of an IPv4 packet. @@ -100,6 +101,11 @@ const ( // IPv4Version is the version of the ipv4 protocol. IPv4Version = 4 + // IPv4AllSystems is the all systems IPv4 multicast address as per + // IANA's IPv4 Multicast Address Space Registry. See + // https://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml. + IPv4AllSystems tcpip.Address = "\xe0\x00\x00\x01" + // IPv4Broadcast is the broadcast address of the IPv4 procotol. IPv4Broadcast tcpip.Address = "\xff\xff\xff\xff" @@ -138,7 +144,7 @@ func IPVersion(b []byte) int { } // HeaderLength returns the value of the "header length" field of the ipv4 -// header. +// header. The length returned is in bytes. func (b IPv4) HeaderLength() uint8 { return (b[versIHL] & 0xf) * 4 } @@ -158,6 +164,11 @@ func (b IPv4) Flags() uint8 { return uint8(binary.BigEndian.Uint16(b[flagsFO:]) >> 13) } +// More returns whether the more fragments flag is set. +func (b IPv4) More() bool { + return b.Flags()&IPv4FlagMoreFragments != 0 +} + // TTL returns the "TTL" field of the ipv4 header. func (b IPv4) TTL() uint8 { return b[ttl] @@ -304,3 +315,12 @@ func IsV4MulticastAddress(addr tcpip.Address) bool { } return (addr[0] & 0xf0) == 0xe0 } + +// IsV4LoopbackAddress determines if the provided address is an IPv4 loopback +// address (belongs to 127.0.0.1/8 subnet). +func IsV4LoopbackAddress(addr tcpip.Address) bool { + if len(addr) != IPv4AddressSize { + return false + } + return addr[0] == 0x7f +} diff --git a/pkg/tcpip/header/ipv6.go b/pkg/tcpip/header/ipv6.go index f1e60911b..ea3823898 100644 --- a/pkg/tcpip/header/ipv6.go +++ b/pkg/tcpip/header/ipv6.go @@ -15,7 +15,9 @@ package header import ( + "crypto/sha256" "encoding/binary" + "fmt" "strings" "gvisor.dev/gvisor/pkg/tcpip" @@ -26,7 +28,9 @@ const ( // IPv6PayloadLenOffset is the offset of the PayloadLength field in // IPv6 header. IPv6PayloadLenOffset = 4 - nextHdr = 6 + // IPv6NextHeaderOffset is the offset of the NextHeader field in + // IPv6 header. + IPv6NextHeaderOffset = 6 hopLimit = 7 v6SrcAddr = 8 v6DstAddr = v6SrcAddr + IPv6AddressSize @@ -83,16 +87,58 @@ const ( // The address is ff02::1. IPv6AllNodesMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" + // IPv6AllRoutersMulticastAddress is a link-local multicast group that + // all IPv6 routers MUST join, as per RFC 4291, section 2.8. Packets + // destined to this address will reach all routers on a link. + // + // The address is ff02::2. + IPv6AllRoutersMulticastAddress tcpip.Address = "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02" + // IPv6MinimumMTU is the minimum MTU required by IPv6, per RFC 2460, // section 5. IPv6MinimumMTU = 1280 + // IPv6Loopback is the IPv6 Loopback address. + IPv6Loopback tcpip.Address = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01" + // IPv6Any is the non-routable IPv6 "any" meta address. It is also // known as the unspecified address. IPv6Any tcpip.Address = "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + + // IIDSize is the size of an interface identifier (IID), in bytes, as + // defined by RFC 4291 section 2.5.1. + IIDSize = 8 + + // IIDOffsetInIPv6Address is the offset, in bytes, from the start + // of an IPv6 address to the beginning of the interface identifier + // (IID) for auto-generated addresses. That is, all bytes before + // the IIDOffsetInIPv6Address-th byte are the prefix bytes, and all + // bytes including and after the IIDOffsetInIPv6Address-th byte are + // for the IID. + IIDOffsetInIPv6Address = 8 + + // OpaqueIIDSecretKeyMinBytes is the recommended minimum number of bytes + // for the secret key used to generate an opaque interface identifier as + // outlined by RFC 7217. + OpaqueIIDSecretKeyMinBytes = 16 + + // ipv6MulticastAddressScopeByteIdx is the byte where the scope (scop) field + // is located within a multicast IPv6 address, as per RFC 4291 section 2.7. + ipv6MulticastAddressScopeByteIdx = 1 + + // ipv6MulticastAddressScopeMask is the mask for the scope (scop) field, + // within the byte holding the field, as per RFC 4291 section 2.7. + ipv6MulticastAddressScopeMask = 0xF + + // ipv6LinkLocalMulticastScope is the value of the scope (scop) field within + // a multicast IPv6 address that indicates the address has link-local scope, + // as per RFC 4291 section 2.7. + ipv6LinkLocalMulticastScope = 2 ) -// IPv6EmptySubnet is the empty IPv6 subnet. +// IPv6EmptySubnet is the empty IPv6 subnet. It may also be known as the +// catch-all or wildcard subnet. That is, all IPv6 addresses are considered to +// be contained within this subnet. var IPv6EmptySubnet = func() tcpip.Subnet { subnet, err := tcpip.NewSubnet(IPv6Any, tcpip.AddressMask(IPv6Any)) if err != nil { @@ -123,7 +169,7 @@ func (b IPv6) HopLimit() uint8 { // NextHeader returns the value of the "next header" field of the ipv6 header. func (b IPv6) NextHeader() uint8 { - return b[nextHdr] + return b[IPv6NextHeaderOffset] } // TransportProtocol implements Network.TransportProtocol. @@ -183,7 +229,7 @@ func (b IPv6) SetDestinationAddress(addr tcpip.Address) { // SetNextHeader sets the value of the "next header" field of the ipv6 header. func (b IPv6) SetNextHeader(v uint8) { - b[nextHdr] = v + b[IPv6NextHeaderOffset] = v } // SetChecksum implements Network.SetChecksum. Given that IPv6 doesn't have a @@ -195,7 +241,7 @@ func (IPv6) SetChecksum(uint16) { func (b IPv6) Encode(i *IPv6Fields) { b.SetTOS(i.TrafficClass, i.FlowLabel) b.SetPayloadLength(i.PayloadLength) - b[nextHdr] = i.NextHeader + b[IPv6NextHeaderOffset] = i.NextHeader b[hopLimit] = i.HopLimit b.SetSourceAddress(i.SrcAddr) b.SetDestinationAddress(i.DstAddr) @@ -264,27 +310,43 @@ func SolicitedNodeAddr(addr tcpip.Address) tcpip.Address { return solicitedNodeMulticastPrefix + addr[len(addr)-3:] } +// EthernetAdddressToModifiedEUI64IntoBuf populates buf with a modified EUI-64 +// from a 48-bit Ethernet/MAC address, as per RFC 4291 section 2.5.1. +// +// buf MUST be at least 8 bytes. +func EthernetAdddressToModifiedEUI64IntoBuf(linkAddr tcpip.LinkAddress, buf []byte) { + buf[0] = linkAddr[0] ^ 2 + buf[1] = linkAddr[1] + buf[2] = linkAddr[2] + buf[3] = 0xFF + buf[4] = 0xFE + buf[5] = linkAddr[3] + buf[6] = linkAddr[4] + buf[7] = linkAddr[5] +} + +// EthernetAddressToModifiedEUI64 computes a modified EUI-64 from a 48-bit +// Ethernet/MAC address, as per RFC 4291 section 2.5.1. +func EthernetAddressToModifiedEUI64(linkAddr tcpip.LinkAddress) [IIDSize]byte { + var buf [IIDSize]byte + EthernetAdddressToModifiedEUI64IntoBuf(linkAddr, buf[:]) + return buf +} + // LinkLocalAddr computes the default IPv6 link-local address from a link-layer // (MAC) address. func LinkLocalAddr(linkAddr tcpip.LinkAddress) tcpip.Address { - // Convert a 48-bit MAC to an EUI-64 and then prepend the link-local - // header, FE80::. + // Convert a 48-bit MAC to a modified EUI-64 and then prepend the + // link-local header, FE80::. // // The conversion is very nearly: // aa:bb:cc:dd:ee:ff => FE80::Aabb:ccFF:FEdd:eeff // Note the capital A. The conversion aa->Aa involves a bit flip. - lladdrb := [16]byte{ - 0: 0xFE, - 1: 0x80, - 8: linkAddr[0] ^ 2, - 9: linkAddr[1], - 10: linkAddr[2], - 11: 0xFF, - 12: 0xFE, - 13: linkAddr[3], - 14: linkAddr[4], - 15: linkAddr[5], + lladdrb := [IPv6AddressSize]byte{ + 0: 0xFE, + 1: 0x80, } + EthernetAdddressToModifiedEUI64IntoBuf(linkAddr, lladdrb[IIDOffsetInIPv6Address:]) return tcpip.Address(lladdrb[:]) } @@ -296,3 +358,145 @@ func IsV6LinkLocalAddress(addr tcpip.Address) bool { } return addr[0] == 0xfe && (addr[1]&0xc0) == 0x80 } + +// IsV6LinkLocalMulticastAddress determines if the provided address is an IPv6 +// link-local multicast address. +func IsV6LinkLocalMulticastAddress(addr tcpip.Address) bool { + return IsV6MulticastAddress(addr) && addr[ipv6MulticastAddressScopeByteIdx]&ipv6MulticastAddressScopeMask == ipv6LinkLocalMulticastScope +} + +// IsV6UniqueLocalAddress determines if the provided address is an IPv6 +// unique-local address (within the prefix FC00::/7). +func IsV6UniqueLocalAddress(addr tcpip.Address) bool { + if len(addr) != IPv6AddressSize { + return false + } + // According to RFC 4193 section 3.1, a unique local address has the prefix + // FC00::/7. + return (addr[0] & 0xfe) == 0xfc +} + +// AppendOpaqueInterfaceIdentifier appends a 64 bit opaque interface identifier +// (IID) to buf as outlined by RFC 7217 and returns the extended buffer. +// +// The opaque IID is generated from the cryptographic hash of the concatenation +// of the prefix, NIC's name, DAD counter (DAD retry counter) and the secret +// key. The secret key SHOULD be at least OpaqueIIDSecretKeyMinBytes bytes and +// MUST be generated to a pseudo-random number. See RFC 4086 for randomness +// requirements for security. +// +// If buf has enough capacity for the IID (IIDSize bytes), a new underlying +// array for the buffer will not be allocated. +func AppendOpaqueInterfaceIdentifier(buf []byte, prefix tcpip.Subnet, nicName string, dadCounter uint8, secretKey []byte) []byte { + // As per RFC 7217 section 5, the opaque identifier can be generated as a + // cryptographic hash of the concatenation of each of the function parameters. + // Note, we omit the optional Network_ID field. + h := sha256.New() + // h.Write never returns an error. + h.Write([]byte(prefix.ID()[:IIDOffsetInIPv6Address])) + h.Write([]byte(nicName)) + h.Write([]byte{dadCounter}) + h.Write(secretKey) + + var sumBuf [sha256.Size]byte + sum := h.Sum(sumBuf[:0]) + + return append(buf, sum[:IIDSize]...) +} + +// LinkLocalAddrWithOpaqueIID computes the default IPv6 link-local address with +// an opaque IID. +func LinkLocalAddrWithOpaqueIID(nicName string, dadCounter uint8, secretKey []byte) tcpip.Address { + lladdrb := [IPv6AddressSize]byte{ + 0: 0xFE, + 1: 0x80, + } + + return tcpip.Address(AppendOpaqueInterfaceIdentifier(lladdrb[:IIDOffsetInIPv6Address], IPv6LinkLocalPrefix.Subnet(), nicName, dadCounter, secretKey)) +} + +// IPv6AddressScope is the scope of an IPv6 address. +type IPv6AddressScope int + +const ( + // LinkLocalScope indicates a link-local address. + LinkLocalScope IPv6AddressScope = iota + + // UniqueLocalScope indicates a unique-local address. + UniqueLocalScope + + // GlobalScope indicates a global address. + GlobalScope +) + +// ScopeForIPv6Address returns the scope for an IPv6 address. +func ScopeForIPv6Address(addr tcpip.Address) (IPv6AddressScope, *tcpip.Error) { + if len(addr) != IPv6AddressSize { + return GlobalScope, tcpip.ErrBadAddress + } + + switch { + case IsV6LinkLocalMulticastAddress(addr): + return LinkLocalScope, nil + + case IsV6LinkLocalAddress(addr): + return LinkLocalScope, nil + + case IsV6UniqueLocalAddress(addr): + return UniqueLocalScope, nil + + default: + return GlobalScope, nil + } +} + +// InitialTempIID generates the initial temporary IID history value to generate +// temporary SLAAC addresses with. +// +// Panics if initialTempIIDHistory is not at least IIDSize bytes. +func InitialTempIID(initialTempIIDHistory []byte, seed []byte, nicID tcpip.NICID) { + h := sha256.New() + // h.Write never returns an error. + h.Write(seed) + var nicIDBuf [4]byte + binary.BigEndian.PutUint32(nicIDBuf[:], uint32(nicID)) + h.Write(nicIDBuf[:]) + + var sumBuf [sha256.Size]byte + sum := h.Sum(sumBuf[:0]) + + if n := copy(initialTempIIDHistory, sum[sha256.Size-IIDSize:]); n != IIDSize { + panic(fmt.Sprintf("copied %d bytes, expected %d bytes", n, IIDSize)) + } +} + +// GenerateTempIPv6SLAACAddr generates a temporary SLAAC IPv6 address for an +// associated stable/permanent SLAAC address. +// +// GenerateTempIPv6SLAACAddr will update the temporary IID history value to be +// used when generating a new temporary IID. +// +// Panics if tempIIDHistory is not at least IIDSize bytes. +func GenerateTempIPv6SLAACAddr(tempIIDHistory []byte, stableAddr tcpip.Address) tcpip.AddressWithPrefix { + addrBytes := []byte(stableAddr) + h := sha256.New() + h.Write(tempIIDHistory) + h.Write(addrBytes[IIDOffsetInIPv6Address:]) + var sumBuf [sha256.Size]byte + sum := h.Sum(sumBuf[:0]) + + // The rightmost 64 bits of sum are saved for the next iteration. + if n := copy(tempIIDHistory, sum[sha256.Size-IIDSize:]); n != IIDSize { + panic(fmt.Sprintf("copied %d bytes, expected %d bytes", n, IIDSize)) + } + + // The leftmost 64 bits of sum is used as the IID. + if n := copy(addrBytes[IIDOffsetInIPv6Address:], sum); n != IIDSize { + panic(fmt.Sprintf("copied %d IID bytes, expected %d bytes", n, IIDSize)) + } + + return tcpip.AddressWithPrefix{ + Address: tcpip.Address(addrBytes), + PrefixLen: IIDOffsetInIPv6Address * 8, + } +} diff --git a/pkg/tcpip/header/ipv6_extension_headers.go b/pkg/tcpip/header/ipv6_extension_headers.go new file mode 100644 index 000000000..3499d8399 --- /dev/null +++ b/pkg/tcpip/header/ipv6_extension_headers.go @@ -0,0 +1,551 @@ +// 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 header + +import ( + "bufio" + "bytes" + "encoding/binary" + "fmt" + "io" + + "gvisor.dev/gvisor/pkg/tcpip/buffer" +) + +// IPv6ExtensionHeaderIdentifier is an IPv6 extension header identifier. +type IPv6ExtensionHeaderIdentifier uint8 + +const ( + // IPv6HopByHopOptionsExtHdrIdentifier is the header identifier of a Hop by + // Hop Options extension header, as per RFC 8200 section 4.3. + IPv6HopByHopOptionsExtHdrIdentifier IPv6ExtensionHeaderIdentifier = 0 + + // IPv6RoutingExtHdrIdentifier is the header identifier of a Routing extension + // header, as per RFC 8200 section 4.4. + IPv6RoutingExtHdrIdentifier IPv6ExtensionHeaderIdentifier = 43 + + // IPv6FragmentExtHdrIdentifier is the header identifier of a Fragment + // extension header, as per RFC 8200 section 4.5. + IPv6FragmentExtHdrIdentifier IPv6ExtensionHeaderIdentifier = 44 + + // IPv6DestinationOptionsExtHdrIdentifier is the header identifier of a + // Destination Options extension header, as per RFC 8200 section 4.6. + IPv6DestinationOptionsExtHdrIdentifier IPv6ExtensionHeaderIdentifier = 60 + + // IPv6NoNextHeaderIdentifier is the header identifier used to signify the end + // of an IPv6 payload, as per RFC 8200 section 4.7. + IPv6NoNextHeaderIdentifier IPv6ExtensionHeaderIdentifier = 59 +) + +const ( + // ipv6UnknownExtHdrOptionActionMask is the mask of the action to take when + // a node encounters an unrecognized option. + ipv6UnknownExtHdrOptionActionMask = 192 + + // ipv6UnknownExtHdrOptionActionShift is the least significant bits to discard + // from the action value for an unrecognized option identifier. + ipv6UnknownExtHdrOptionActionShift = 6 + + // ipv6RoutingExtHdrSegmentsLeftIdx is the index to the Segments Left field + // within an IPv6RoutingExtHdr. + ipv6RoutingExtHdrSegmentsLeftIdx = 1 + + // IPv6FragmentExtHdrLength is the length of an IPv6 extension header, in + // bytes. + IPv6FragmentExtHdrLength = 8 + + // ipv6FragmentExtHdrFragmentOffsetOffset is the offset to the start of the + // Fragment Offset field within an IPv6FragmentExtHdr. + ipv6FragmentExtHdrFragmentOffsetOffset = 0 + + // ipv6FragmentExtHdrFragmentOffsetShift is the least significant bits to + // discard from the Fragment Offset. + ipv6FragmentExtHdrFragmentOffsetShift = 3 + + // ipv6FragmentExtHdrFlagsIdx is the index to the flags field within an + // IPv6FragmentExtHdr. + ipv6FragmentExtHdrFlagsIdx = 1 + + // ipv6FragmentExtHdrMFlagMask is the mask of the More (M) flag within the + // flags field of an IPv6FragmentExtHdr. + ipv6FragmentExtHdrMFlagMask = 1 + + // ipv6FragmentExtHdrIdentificationOffset is the offset to the Identification + // field within an IPv6FragmentExtHdr. + ipv6FragmentExtHdrIdentificationOffset = 2 + + // ipv6ExtHdrLenBytesPerUnit is the unit size of an extension header's length + // field. That is, given a Length field of 2, the extension header expects + // 16 bytes following the first 8 bytes (see ipv6ExtHdrLenBytesExcluded for + // details about the first 8 bytes' exclusion from the Length field). + ipv6ExtHdrLenBytesPerUnit = 8 + + // ipv6ExtHdrLenBytesExcluded is the number of bytes excluded from an + // extension header's Length field following the Length field. + // + // The Length field excludes the first 8 bytes, but the Next Header and Length + // field take up the first 2 of the 8 bytes so we expect (at minimum) 6 bytes + // after the Length field. + // + // This ensures that every extension header is at least 8 bytes. + ipv6ExtHdrLenBytesExcluded = 6 + + // IPv6FragmentExtHdrFragmentOffsetBytesPerUnit is the unit size of a Fragment + // extension header's Fragment Offset field. That is, given a Fragment Offset + // of 2, the extension header is indiciating that the fragment's payload + // starts at the 16th byte in the reassembled packet. + IPv6FragmentExtHdrFragmentOffsetBytesPerUnit = 8 +) + +// IPv6PayloadHeader is implemented by the various headers that can be found +// in an IPv6 payload. +// +// These headers include IPv6 extension headers or upper layer data. +type IPv6PayloadHeader interface { + isIPv6PayloadHeader() +} + +// IPv6RawPayloadHeader the remainder of an IPv6 payload after an iterator +// encounters a Next Header field it does not recognize as an IPv6 extension +// header. +type IPv6RawPayloadHeader struct { + Identifier IPv6ExtensionHeaderIdentifier + Buf buffer.VectorisedView +} + +// isIPv6PayloadHeader implements IPv6PayloadHeader.isIPv6PayloadHeader. +func (IPv6RawPayloadHeader) isIPv6PayloadHeader() {} + +// ipv6OptionsExtHdr is an IPv6 extension header that holds options. +type ipv6OptionsExtHdr []byte + +// Iter returns an iterator over the IPv6 extension header options held in b. +func (b ipv6OptionsExtHdr) Iter() IPv6OptionsExtHdrOptionsIterator { + it := IPv6OptionsExtHdrOptionsIterator{} + it.reader.Reset(b) + return it +} + +// IPv6OptionsExtHdrOptionsIterator is an iterator over IPv6 extension header +// options. +// +// Note, between when an IPv6OptionsExtHdrOptionsIterator is obtained and last +// used, no changes to the underlying buffer may happen. Doing so may cause +// undefined and unexpected behaviour. It is fine to obtain an +// IPv6OptionsExtHdrOptionsIterator, iterate over the first few options then +// modify the backing payload so long as the IPv6OptionsExtHdrOptionsIterator +// obtained before modification is no longer used. +type IPv6OptionsExtHdrOptionsIterator struct { + reader bytes.Reader +} + +// IPv6OptionUnknownAction is the action that must be taken if the processing +// IPv6 node does not recognize the option, as outlined in RFC 8200 section 4.2. +type IPv6OptionUnknownAction int + +const ( + // IPv6OptionUnknownActionSkip indicates that the unrecognized option must + // be skipped and the node should continue processing the header. + IPv6OptionUnknownActionSkip IPv6OptionUnknownAction = 0 + + // IPv6OptionUnknownActionDiscard indicates that the packet must be silently + // discarded. + IPv6OptionUnknownActionDiscard IPv6OptionUnknownAction = 1 + + // IPv6OptionUnknownActionDiscardSendICMP indicates that the packet must be + // discarded and the node must send an ICMP Parameter Problem, Code 2, message + // to the packet's source, regardless of whether or not the packet's + // Destination was a multicast address. + IPv6OptionUnknownActionDiscardSendICMP IPv6OptionUnknownAction = 2 + + // IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest indicates that the + // packet must be discarded and the node must send an ICMP Parameter Problem, + // Code 2, message to the packet's source only if the packet's Destination was + // not a multicast address. + IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest IPv6OptionUnknownAction = 3 +) + +// IPv6ExtHdrOption is implemented by the various IPv6 extension header options. +type IPv6ExtHdrOption interface { + // UnknownAction returns the action to take in response to an unrecognized + // option. + UnknownAction() IPv6OptionUnknownAction + + // isIPv6ExtHdrOption is used to "lock" this interface so it is not + // implemented by other packages. + isIPv6ExtHdrOption() +} + +// IPv6ExtHdrOptionIndentifier is an IPv6 extension header option identifier. +type IPv6ExtHdrOptionIndentifier uint8 + +const ( + // ipv6Pad1ExtHdrOptionIdentifier is the identifier for a padding option that + // provides 1 byte padding, as outlined in RFC 8200 section 4.2. + ipv6Pad1ExtHdrOptionIdentifier IPv6ExtHdrOptionIndentifier = 0 + + // ipv6PadBExtHdrOptionIdentifier is the identifier for a padding option that + // provides variable length byte padding, as outlined in RFC 8200 section 4.2. + ipv6PadNExtHdrOptionIdentifier IPv6ExtHdrOptionIndentifier = 1 +) + +// IPv6UnknownExtHdrOption holds the identifier and data for an IPv6 extension +// header option that is unknown by the parsing utilities. +type IPv6UnknownExtHdrOption struct { + Identifier IPv6ExtHdrOptionIndentifier + Data []byte +} + +// UnknownAction implements IPv6OptionUnknownAction.UnknownAction. +func (o *IPv6UnknownExtHdrOption) UnknownAction() IPv6OptionUnknownAction { + return IPv6OptionUnknownAction((o.Identifier & ipv6UnknownExtHdrOptionActionMask) >> ipv6UnknownExtHdrOptionActionShift) +} + +// isIPv6ExtHdrOption implements IPv6ExtHdrOption.isIPv6ExtHdrOption. +func (*IPv6UnknownExtHdrOption) isIPv6ExtHdrOption() {} + +// Next returns the next option in the options data. +// +// If the next item is not a known extension header option, +// IPv6UnknownExtHdrOption will be returned with the option identifier and data. +// +// The return is of the format (option, done, error). done will be true when +// Next is unable to return anything because the iterator has reached the end of +// the options data, or an error occured. +func (i *IPv6OptionsExtHdrOptionsIterator) Next() (IPv6ExtHdrOption, bool, error) { + for { + temp, err := i.reader.ReadByte() + if err != nil { + // If we can't read the first byte of a new option, then we know the + // options buffer has been exhausted and we are done iterating. + return nil, true, nil + } + id := IPv6ExtHdrOptionIndentifier(temp) + + // If the option identifier indicates the option is a Pad1 option, then we + // know the option does not have Length and Data fields. End processing of + // the Pad1 option and continue processing the buffer as a new option. + if id == ipv6Pad1ExtHdrOptionIdentifier { + continue + } + + length, err := i.reader.ReadByte() + if err != nil { + if err != io.EOF { + // ReadByte should only ever return nil or io.EOF. + panic(fmt.Sprintf("unexpected error when reading the option's Length field for option with id = %d: %s", id, err)) + } + + // We use io.ErrUnexpectedEOF as exhausting the buffer is unexpected once + // we start parsing an option; we expect the reader to contain enough + // bytes for the whole option. + return nil, true, fmt.Errorf("error when reading the option's Length field for option with id = %d: %w", id, io.ErrUnexpectedEOF) + } + + // Special-case the variable length padding option to avoid a copy. + if id == ipv6PadNExtHdrOptionIdentifier { + // Do we have enough bytes in the reader for the PadN option? + if n := i.reader.Len(); n < int(length) { + // Reset the reader to effectively consume the remaining buffer. + i.reader.Reset(nil) + + // We return the same error as if we failed to read a non-padding option + // so consumers of this iterator don't need to differentiate between + // padding and non-padding options. + return nil, true, fmt.Errorf("read %d out of %d option data bytes for option with id = %d: %w", n, length, id, io.ErrUnexpectedEOF) + } + + if _, err := i.reader.Seek(int64(length), io.SeekCurrent); err != nil { + panic(fmt.Sprintf("error when skipping PadN (N = %d) option's data bytes: %s", length, err)) + } + + // End processing of the PadN option and continue processing the buffer as + // a new option. + continue + } + + bytes := make([]byte, length) + if n, err := io.ReadFull(&i.reader, bytes); err != nil { + // io.ReadFull may return io.EOF if i.reader has been exhausted. We use + // io.ErrUnexpectedEOF instead as the io.EOF is unexpected given the + // Length field found in the option. + if err == io.EOF { + err = io.ErrUnexpectedEOF + } + + return nil, true, fmt.Errorf("read %d out of %d option data bytes for option with id = %d: %w", n, length, id, err) + } + + return &IPv6UnknownExtHdrOption{Identifier: id, Data: bytes}, false, nil + } +} + +// IPv6HopByHopOptionsExtHdr is a buffer holding the Hop By Hop Options +// extension header. +type IPv6HopByHopOptionsExtHdr struct { + ipv6OptionsExtHdr +} + +// isIPv6PayloadHeader implements IPv6PayloadHeader.isIPv6PayloadHeader. +func (IPv6HopByHopOptionsExtHdr) isIPv6PayloadHeader() {} + +// IPv6DestinationOptionsExtHdr is a buffer holding the Destination Options +// extension header. +type IPv6DestinationOptionsExtHdr struct { + ipv6OptionsExtHdr +} + +// isIPv6PayloadHeader implements IPv6PayloadHeader.isIPv6PayloadHeader. +func (IPv6DestinationOptionsExtHdr) isIPv6PayloadHeader() {} + +// IPv6RoutingExtHdr is a buffer holding the Routing extension header specific +// data as outlined in RFC 8200 section 4.4. +type IPv6RoutingExtHdr []byte + +// isIPv6PayloadHeader implements IPv6PayloadHeader.isIPv6PayloadHeader. +func (IPv6RoutingExtHdr) isIPv6PayloadHeader() {} + +// SegmentsLeft returns the Segments Left field. +func (b IPv6RoutingExtHdr) SegmentsLeft() uint8 { + return b[ipv6RoutingExtHdrSegmentsLeftIdx] +} + +// IPv6FragmentExtHdr is a buffer holding the Fragment extension header specific +// data as outlined in RFC 8200 section 4.5. +// +// Note, the buffer does not include the Next Header and Reserved fields. +type IPv6FragmentExtHdr [6]byte + +// isIPv6PayloadHeader implements IPv6PayloadHeader.isIPv6PayloadHeader. +func (IPv6FragmentExtHdr) isIPv6PayloadHeader() {} + +// FragmentOffset returns the Fragment Offset field. +// +// This value indicates where the buffer following the Fragment extension header +// starts in the target (reassembled) packet. +func (b IPv6FragmentExtHdr) FragmentOffset() uint16 { + return binary.BigEndian.Uint16(b[ipv6FragmentExtHdrFragmentOffsetOffset:]) >> ipv6FragmentExtHdrFragmentOffsetShift +} + +// More returns the More (M) flag. +// +// This indicates whether any fragments are expected to succeed b. +func (b IPv6FragmentExtHdr) More() bool { + return b[ipv6FragmentExtHdrFlagsIdx]&ipv6FragmentExtHdrMFlagMask != 0 +} + +// ID returns the Identification field. +// +// This value is used to uniquely identify the packet, between a +// souce and destination. +func (b IPv6FragmentExtHdr) ID() uint32 { + return binary.BigEndian.Uint32(b[ipv6FragmentExtHdrIdentificationOffset:]) +} + +// IsAtomic returns whether the fragment header indicates an atomic fragment. An +// atomic fragment is a fragment that contains all the data required to +// reassemble a full packet. +func (b IPv6FragmentExtHdr) IsAtomic() bool { + return !b.More() && b.FragmentOffset() == 0 +} + +// IPv6PayloadIterator is an iterator over the contents of an IPv6 payload. +// +// The IPv6 payload may contain IPv6 extension headers before any upper layer +// data. +// +// Note, between when an IPv6PayloadIterator is obtained and last used, no +// changes to the payload may happen. Doing so may cause undefined and +// unexpected behaviour. It is fine to obtain an IPv6PayloadIterator, iterate +// over the first few headers then modify the backing payload so long as the +// IPv6PayloadIterator obtained before modification is no longer used. +type IPv6PayloadIterator struct { + // The identifier of the next header to parse. + nextHdrIdentifier IPv6ExtensionHeaderIdentifier + + // reader is an io.Reader over payload. + reader bufio.Reader + payload buffer.VectorisedView + + // Indicates to the iterator that it should return the remaining payload as a + // raw payload on the next call to Next. + forceRaw bool +} + +// MakeIPv6PayloadIterator returns an iterator over the IPv6 payload containing +// extension headers, or a raw payload if the payload cannot be parsed. +func MakeIPv6PayloadIterator(nextHdrIdentifier IPv6ExtensionHeaderIdentifier, payload buffer.VectorisedView) IPv6PayloadIterator { + readers := payload.Readers() + readerPs := make([]io.Reader, 0, len(readers)) + for i := range readers { + readerPs = append(readerPs, &readers[i]) + } + + return IPv6PayloadIterator{ + nextHdrIdentifier: nextHdrIdentifier, + payload: payload.Clone(nil), + // We need a buffer of size 1 for calls to bufio.Reader.ReadByte. + reader: *bufio.NewReaderSize(io.MultiReader(readerPs...), 1), + } +} + +// AsRawHeader returns the remaining payload of i as a raw header and +// optionally consumes the iterator. +// +// If consume is true, calls to Next after calling AsRawHeader on i will +// indicate that the iterator is done. +func (i *IPv6PayloadIterator) AsRawHeader(consume bool) IPv6RawPayloadHeader { + identifier := i.nextHdrIdentifier + + var buf buffer.VectorisedView + if consume { + // Since we consume the iterator, we return the payload as is. + buf = i.payload + + // Mark i as done. + *i = IPv6PayloadIterator{ + nextHdrIdentifier: IPv6NoNextHeaderIdentifier, + } + } else { + buf = i.payload.Clone(nil) + } + + return IPv6RawPayloadHeader{Identifier: identifier, Buf: buf} +} + +// Next returns the next item in the payload. +// +// If the next item is not a known IPv6 extension header, IPv6RawPayloadHeader +// will be returned with the remaining bytes and next header identifier. +// +// The return is of the format (header, done, error). done will be true when +// Next is unable to return anything because the iterator has reached the end of +// the payload, or an error occured. +func (i *IPv6PayloadIterator) Next() (IPv6PayloadHeader, bool, error) { + // We could be forced to return i as a raw header when the previous header was + // a fragment extension header as the data following the fragment extension + // header may not be complete. + if i.forceRaw { + return i.AsRawHeader(true /* consume */), false, nil + } + + // Is the header we are parsing a known extension header? + switch i.nextHdrIdentifier { + case IPv6HopByHopOptionsExtHdrIdentifier: + nextHdrIdentifier, bytes, err := i.nextHeaderData(false /* fragmentHdr */, nil) + if err != nil { + return nil, true, err + } + + i.nextHdrIdentifier = nextHdrIdentifier + return IPv6HopByHopOptionsExtHdr{ipv6OptionsExtHdr: bytes}, false, nil + case IPv6RoutingExtHdrIdentifier: + nextHdrIdentifier, bytes, err := i.nextHeaderData(false /* fragmentHdr */, nil) + if err != nil { + return nil, true, err + } + + i.nextHdrIdentifier = nextHdrIdentifier + return IPv6RoutingExtHdr(bytes), false, nil + case IPv6FragmentExtHdrIdentifier: + var data [6]byte + // We ignore the returned bytes becauase we know the fragment extension + // header specific data will fit in data. + nextHdrIdentifier, _, err := i.nextHeaderData(true /* fragmentHdr */, data[:]) + if err != nil { + return nil, true, err + } + + fragmentExtHdr := IPv6FragmentExtHdr(data) + + // If the packet is not the first fragment, do not attempt to parse anything + // after the fragment extension header as the payload following the fragment + // extension header should not contain any headers; the first fragment must + // hold all the headers up to and including any upper layer headers, as per + // RFC 8200 section 4.5. + if fragmentExtHdr.FragmentOffset() != 0 { + i.forceRaw = true + } + + i.nextHdrIdentifier = nextHdrIdentifier + return fragmentExtHdr, false, nil + case IPv6DestinationOptionsExtHdrIdentifier: + nextHdrIdentifier, bytes, err := i.nextHeaderData(false /* fragmentHdr */, nil) + if err != nil { + return nil, true, err + } + + i.nextHdrIdentifier = nextHdrIdentifier + return IPv6DestinationOptionsExtHdr{ipv6OptionsExtHdr: bytes}, false, nil + case IPv6NoNextHeaderIdentifier: + // This indicates the end of the IPv6 payload. + return nil, true, nil + + default: + // The header we are parsing is not a known extension header. Return the + // raw payload. + return i.AsRawHeader(true /* consume */), false, nil + } +} + +// nextHeaderData returns the extension header's Next Header field and raw data. +// +// fragmentHdr indicates that the extension header being parsed is the Fragment +// extension header so the Length field should be ignored as it is Reserved +// for the Fragment extension header. +// +// If bytes is not nil, extension header specific data will be read into bytes +// if it has enough capacity. If bytes is provided but does not have enough +// capacity for the data, nextHeaderData will panic. +func (i *IPv6PayloadIterator) nextHeaderData(fragmentHdr bool, bytes []byte) (IPv6ExtensionHeaderIdentifier, []byte, error) { + // We ignore the number of bytes read because we know we will only ever read + // at max 1 bytes since rune has a length of 1. If we read 0 bytes, the Read + // would return io.EOF to indicate that io.Reader has reached the end of the + // payload. + nextHdrIdentifier, err := i.reader.ReadByte() + i.payload.TrimFront(1) + if err != nil { + return 0, nil, fmt.Errorf("error when reading the Next Header field for extension header with id = %d: %w", i.nextHdrIdentifier, err) + } + + var length uint8 + length, err = i.reader.ReadByte() + i.payload.TrimFront(1) + if err != nil { + if fragmentHdr { + return 0, nil, fmt.Errorf("error when reading the Length field for extension header with id = %d: %w", i.nextHdrIdentifier, err) + } + + return 0, nil, fmt.Errorf("error when reading the Reserved field for extension header with id = %d: %w", i.nextHdrIdentifier, err) + } + if fragmentHdr { + length = 0 + } + + bytesLen := int(length)*ipv6ExtHdrLenBytesPerUnit + ipv6ExtHdrLenBytesExcluded + if bytes == nil { + bytes = make([]byte, bytesLen) + } else if n := len(bytes); n < bytesLen { + panic(fmt.Sprintf("bytes only has space for %d bytes but need space for %d bytes (length = %d) for extension header with id = %d", n, bytesLen, length, i.nextHdrIdentifier)) + } + + n, err := io.ReadFull(&i.reader, bytes) + i.payload.TrimFront(n) + if err != nil { + return 0, nil, fmt.Errorf("read %d out of %d extension header data bytes (length = %d) for header with id = %d: %w", n, bytesLen, length, i.nextHdrIdentifier, err) + } + + return IPv6ExtensionHeaderIdentifier(nextHdrIdentifier), bytes, nil +} diff --git a/pkg/tcpip/header/ipv6_extension_headers_test.go b/pkg/tcpip/header/ipv6_extension_headers_test.go new file mode 100644 index 000000000..ab20c5f37 --- /dev/null +++ b/pkg/tcpip/header/ipv6_extension_headers_test.go @@ -0,0 +1,992 @@ +// 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 header + +import ( + "bytes" + "errors" + "io" + "testing" + + "github.com/google/go-cmp/cmp" + "gvisor.dev/gvisor/pkg/tcpip/buffer" +) + +// Equal returns true of a and b are equivalent. +// +// Note, Equal will return true if a and b hold the same Identifier value and +// contain the same bytes in Buf, even if the bytes are split across views +// differently. +// +// Needed to use cmp.Equal on IPv6RawPayloadHeader as it contains unexported +// fields. +func (a IPv6RawPayloadHeader) Equal(b IPv6RawPayloadHeader) bool { + return a.Identifier == b.Identifier && bytes.Equal(a.Buf.ToView(), b.Buf.ToView()) +} + +// Equal returns true of a and b are equivalent. +// +// Note, Equal will return true if a and b hold equivalent ipv6OptionsExtHdrs. +// +// Needed to use cmp.Equal on IPv6RawPayloadHeader as it contains unexported +// fields. +func (a IPv6HopByHopOptionsExtHdr) Equal(b IPv6HopByHopOptionsExtHdr) bool { + return bytes.Equal(a.ipv6OptionsExtHdr, b.ipv6OptionsExtHdr) +} + +// Equal returns true of a and b are equivalent. +// +// Note, Equal will return true if a and b hold equivalent ipv6OptionsExtHdrs. +// +// Needed to use cmp.Equal on IPv6RawPayloadHeader as it contains unexported +// fields. +func (a IPv6DestinationOptionsExtHdr) Equal(b IPv6DestinationOptionsExtHdr) bool { + return bytes.Equal(a.ipv6OptionsExtHdr, b.ipv6OptionsExtHdr) +} + +func TestIPv6UnknownExtHdrOption(t *testing.T) { + tests := []struct { + name string + identifier IPv6ExtHdrOptionIndentifier + expectedUnknownAction IPv6OptionUnknownAction + }{ + { + name: "Skip with zero LSBs", + identifier: 0, + expectedUnknownAction: IPv6OptionUnknownActionSkip, + }, + { + name: "Discard with zero LSBs", + identifier: 64, + expectedUnknownAction: IPv6OptionUnknownActionDiscard, + }, + { + name: "Discard and ICMP with zero LSBs", + identifier: 128, + expectedUnknownAction: IPv6OptionUnknownActionDiscardSendICMP, + }, + { + name: "Discard and ICMP for non multicast destination with zero LSBs", + identifier: 192, + expectedUnknownAction: IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest, + }, + { + name: "Skip with non-zero LSBs", + identifier: 63, + expectedUnknownAction: IPv6OptionUnknownActionSkip, + }, + { + name: "Discard with non-zero LSBs", + identifier: 127, + expectedUnknownAction: IPv6OptionUnknownActionDiscard, + }, + { + name: "Discard and ICMP with non-zero LSBs", + identifier: 191, + expectedUnknownAction: IPv6OptionUnknownActionDiscardSendICMP, + }, + { + name: "Discard and ICMP for non multicast destination with non-zero LSBs", + identifier: 255, + expectedUnknownAction: IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + opt := &IPv6UnknownExtHdrOption{Identifier: test.identifier, Data: []byte{1, 2, 3, 4}} + if a := opt.UnknownAction(); a != test.expectedUnknownAction { + t.Fatalf("got UnknownAction() = %d, want = %d", a, test.expectedUnknownAction) + } + }) + } + +} + +func TestIPv6OptionsExtHdrIterErr(t *testing.T) { + tests := []struct { + name string + bytes []byte + err error + }{ + { + name: "Single unknown with zero length", + bytes: []byte{255, 0}, + }, + { + name: "Single unknown with non-zero length", + bytes: []byte{255, 3, 1, 2, 3}, + }, + { + name: "Two options", + bytes: []byte{ + 255, 0, + 254, 1, 1, + }, + }, + { + name: "Three options", + bytes: []byte{ + 255, 0, + 254, 1, 1, + 253, 4, 2, 3, 4, 5, + }, + }, + { + name: "Single unknown only identifier", + bytes: []byte{255}, + err: io.ErrUnexpectedEOF, + }, + { + name: "Single unknown too small with length = 1", + bytes: []byte{255, 1}, + err: io.ErrUnexpectedEOF, + }, + { + name: "Single unknown too small with length = 2", + bytes: []byte{255, 2, 1}, + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid first with second unknown only identifier", + bytes: []byte{ + 255, 0, + 254, + }, + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid first with second unknown missing data", + bytes: []byte{ + 255, 0, + 254, 1, + }, + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid first with second unknown too small", + bytes: []byte{ + 255, 0, + 254, 2, 1, + }, + err: io.ErrUnexpectedEOF, + }, + { + name: "One Pad1", + bytes: []byte{0}, + }, + { + name: "Multiple Pad1", + bytes: []byte{0, 0, 0}, + }, + { + name: "Multiple PadN", + bytes: []byte{ + // Pad3 + 1, 1, 1, + + // Pad5 + 1, 3, 1, 2, 3, + }, + }, + { + name: "Pad5 too small middle of data buffer", + bytes: []byte{1, 3, 1, 2}, + err: io.ErrUnexpectedEOF, + }, + { + name: "Pad5 no data", + bytes: []byte{1, 3}, + err: io.ErrUnexpectedEOF, + }, + } + + check := func(t *testing.T, it IPv6OptionsExtHdrOptionsIterator, expectedErr error) { + for i := 0; ; i++ { + _, done, err := it.Next() + if err != nil { + // If we encountered a non-nil error while iterating, make sure it is + // is the same error as expectedErr. + if !errors.Is(err, expectedErr) { + t.Fatalf("got %d-th Next() = %v, want = %v", i, err, expectedErr) + } + + return + } + if done { + // If we are done (without an error), make sure that we did not expect + // an error. + if expectedErr != nil { + t.Fatalf("expected error when iterating; want = %s", expectedErr) + } + + return + } + } + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + t.Run("Hop By Hop", func(t *testing.T) { + extHdr := IPv6HopByHopOptionsExtHdr{ipv6OptionsExtHdr: test.bytes} + check(t, extHdr.Iter(), test.err) + }) + + t.Run("Destination", func(t *testing.T) { + extHdr := IPv6DestinationOptionsExtHdr{ipv6OptionsExtHdr: test.bytes} + check(t, extHdr.Iter(), test.err) + }) + }) + } +} + +func TestIPv6OptionsExtHdrIter(t *testing.T) { + tests := []struct { + name string + bytes []byte + expected []IPv6ExtHdrOption + }{ + { + name: "Single unknown with zero length", + bytes: []byte{255, 0}, + expected: []IPv6ExtHdrOption{ + &IPv6UnknownExtHdrOption{Identifier: 255, Data: []byte{}}, + }, + }, + { + name: "Single unknown with non-zero length", + bytes: []byte{255, 3, 1, 2, 3}, + expected: []IPv6ExtHdrOption{ + &IPv6UnknownExtHdrOption{Identifier: 255, Data: []byte{1, 2, 3}}, + }, + }, + { + name: "Single Pad1", + bytes: []byte{0}, + }, + { + name: "Two Pad1", + bytes: []byte{0, 0}, + }, + { + name: "Single Pad3", + bytes: []byte{1, 1, 1}, + }, + { + name: "Single Pad5", + bytes: []byte{1, 3, 1, 2, 3}, + }, + { + name: "Multiple Pad", + bytes: []byte{ + // Pad1 + 0, + + // Pad2 + 1, 0, + + // Pad3 + 1, 1, 1, + + // Pad4 + 1, 2, 1, 2, + + // Pad5 + 1, 3, 1, 2, 3, + }, + }, + { + name: "Multiple options", + bytes: []byte{ + // Pad1 + 0, + + // Unknown + 255, 0, + + // Pad2 + 1, 0, + + // Unknown + 254, 1, 1, + + // Pad3 + 1, 1, 1, + + // Unknown + 253, 4, 2, 3, 4, 5, + + // Pad4 + 1, 2, 1, 2, + }, + expected: []IPv6ExtHdrOption{ + &IPv6UnknownExtHdrOption{Identifier: 255, Data: []byte{}}, + &IPv6UnknownExtHdrOption{Identifier: 254, Data: []byte{1}}, + &IPv6UnknownExtHdrOption{Identifier: 253, Data: []byte{2, 3, 4, 5}}, + }, + }, + } + + checkIter := func(t *testing.T, it IPv6OptionsExtHdrOptionsIterator, expected []IPv6ExtHdrOption) { + for i, e := range expected { + opt, done, err := it.Next() + if err != nil { + t.Errorf("(i=%d) Next(): %s", i, err) + } + if done { + t.Errorf("(i=%d) unexpectedly done iterating", i) + } + if diff := cmp.Diff(e, opt); diff != "" { + t.Errorf("(i=%d) got option mismatch (-want +got):\n%s", i, diff) + } + + if t.Failed() { + t.FailNow() + } + } + + opt, done, err := it.Next() + if err != nil { + t.Errorf("(last) Next(): %s", err) + } + if !done { + t.Errorf("(last) iterator unexpectedly not done") + } + if opt != nil { + t.Errorf("(last) got Next() = %T, want = nil", opt) + } + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + t.Run("Hop By Hop", func(t *testing.T) { + extHdr := IPv6HopByHopOptionsExtHdr{ipv6OptionsExtHdr: test.bytes} + checkIter(t, extHdr.Iter(), test.expected) + }) + + t.Run("Destination", func(t *testing.T) { + extHdr := IPv6DestinationOptionsExtHdr{ipv6OptionsExtHdr: test.bytes} + checkIter(t, extHdr.Iter(), test.expected) + }) + }) + } +} + +func TestIPv6RoutingExtHdr(t *testing.T) { + tests := []struct { + name string + bytes []byte + segmentsLeft uint8 + }{ + { + name: "Zeroes", + bytes: []byte{0, 0, 0, 0, 0, 0}, + segmentsLeft: 0, + }, + { + name: "Ones", + bytes: []byte{1, 1, 1, 1, 1, 1}, + segmentsLeft: 1, + }, + { + name: "Mixed", + bytes: []byte{1, 2, 3, 4, 5, 6}, + segmentsLeft: 2, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + extHdr := IPv6RoutingExtHdr(test.bytes) + if got := extHdr.SegmentsLeft(); got != test.segmentsLeft { + t.Errorf("got SegmentsLeft() = %d, want = %d", got, test.segmentsLeft) + } + }) + } +} + +func TestIPv6FragmentExtHdr(t *testing.T) { + tests := []struct { + name string + bytes [6]byte + fragmentOffset uint16 + more bool + id uint32 + }{ + { + name: "Zeroes", + bytes: [6]byte{0, 0, 0, 0, 0, 0}, + fragmentOffset: 0, + more: false, + id: 0, + }, + { + name: "Ones", + bytes: [6]byte{0, 9, 0, 0, 0, 1}, + fragmentOffset: 1, + more: true, + id: 1, + }, + { + name: "Mixed", + bytes: [6]byte{68, 9, 128, 4, 2, 1}, + fragmentOffset: 2177, + more: true, + id: 2147746305, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + extHdr := IPv6FragmentExtHdr(test.bytes) + if got := extHdr.FragmentOffset(); got != test.fragmentOffset { + t.Errorf("got FragmentOffset() = %d, want = %d", got, test.fragmentOffset) + } + if got := extHdr.More(); got != test.more { + t.Errorf("got More() = %t, want = %t", got, test.more) + } + if got := extHdr.ID(); got != test.id { + t.Errorf("got ID() = %d, want = %d", got, test.id) + } + }) + } +} + +func makeVectorisedViewFromByteBuffers(bs ...[]byte) buffer.VectorisedView { + size := 0 + var vs []buffer.View + + for _, b := range bs { + vs = append(vs, buffer.View(b)) + size += len(b) + } + + return buffer.NewVectorisedView(size, vs) +} + +func TestIPv6ExtHdrIterErr(t *testing.T) { + tests := []struct { + name string + firstNextHdr IPv6ExtensionHeaderIdentifier + payload buffer.VectorisedView + err error + }{ + { + name: "Upper layer only without data", + firstNextHdr: 255, + }, + { + name: "Upper layer only with data", + firstNextHdr: 255, + payload: makeVectorisedViewFromByteBuffers([]byte{1, 2, 3, 4}), + }, + { + name: "No next header", + firstNextHdr: IPv6NoNextHeaderIdentifier, + }, + { + name: "No next header with data", + firstNextHdr: IPv6NoNextHeaderIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{1, 2, 3, 4}), + }, + { + name: "Valid single hop by hop", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 4, 1, 2, 3, 4}), + }, + { + name: "Hop by hop too small", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 4, 1, 2, 3}), + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid single fragment", + firstNextHdr: IPv6FragmentExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 68, 9, 128, 4, 2, 1}), + }, + { + name: "Fragment too small", + firstNextHdr: IPv6FragmentExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 68, 9, 128, 4, 2}), + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid single destination", + firstNextHdr: IPv6DestinationOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 4, 1, 2, 3, 4}), + }, + { + name: "Destination too small", + firstNextHdr: IPv6DestinationOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 4, 1, 2, 3}), + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid single routing", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 2, 3, 4, 5, 6}), + }, + { + name: "Valid single routing across views", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 2}, []byte{3, 4, 5, 6}), + }, + { + name: "Routing too small with zero length field", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 0, 1, 2, 3, 4, 5}), + err: io.ErrUnexpectedEOF, + }, + { + name: "Valid routing with non-zero length field", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 1, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 8}), + }, + { + name: "Valid routing with non-zero length field across views", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 1, 1, 2, 3, 4, 5, 6}, []byte{1, 2, 3, 4, 5, 6, 7, 8}), + }, + { + name: "Routing too small with non-zero length field", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 1, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7}), + err: io.ErrUnexpectedEOF, + }, + { + name: "Routing too small with non-zero length field across views", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{255, 1, 1, 2, 3, 4, 5, 6}, []byte{1, 2, 3, 4, 5, 6, 7}), + err: io.ErrUnexpectedEOF, + }, + { + name: "Mixed", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Hop By Hop Options extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // (Atomic) Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6RoutingExtHdrIdentifier), 255, 0, 6, 128, 4, 2, 1, + + // Routing extension header. + uint8(IPv6DestinationOptionsExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Destination Options extension header. + 255, 0, 255, 4, 1, 2, 3, 4, + + // Upper layer data. + 1, 2, 3, 4, + }), + }, + { + name: "Mixed without upper layer data", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Hop By Hop Options extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // (Atomic) Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6RoutingExtHdrIdentifier), 255, 0, 6, 128, 4, 2, 1, + + // Routing extension header. + uint8(IPv6DestinationOptionsExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Destination Options extension header. + 255, 0, 255, 4, 1, 2, 3, 4, + }), + }, + { + name: "Mixed without upper layer data but last ext hdr too small", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Hop By Hop Options extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // (Atomic) Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6RoutingExtHdrIdentifier), 255, 0, 6, 128, 4, 2, 1, + + // Routing extension header. + uint8(IPv6DestinationOptionsExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Destination Options extension header. + 255, 0, 255, 4, 1, 2, 3, + }), + err: io.ErrUnexpectedEOF, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + it := MakeIPv6PayloadIterator(test.firstNextHdr, test.payload) + + for i := 0; ; i++ { + _, done, err := it.Next() + if err != nil { + // If we encountered a non-nil error while iterating, make sure it is + // is the same error as test.err. + if !errors.Is(err, test.err) { + t.Fatalf("got %d-th Next() = %v, want = %v", i, err, test.err) + } + + return + } + if done { + // If we are done (without an error), make sure that we did not expect + // an error. + if test.err != nil { + t.Fatalf("expected error when iterating; want = %s", test.err) + } + + return + } + } + }) + } +} + +func TestIPv6ExtHdrIter(t *testing.T) { + routingExtHdrWithUpperLayerData := buffer.View([]byte{255, 0, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4}) + upperLayerData := buffer.View([]byte{1, 2, 3, 4}) + tests := []struct { + name string + firstNextHdr IPv6ExtensionHeaderIdentifier + payload buffer.VectorisedView + expected []IPv6PayloadHeader + }{ + // With a non-atomic fragment that is not the first fragment, the payload + // after the fragment will not be parsed because the payload is expected to + // only hold upper layer data. + { + name: "hopbyhop - fragment (not first) - routing - upper", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Hop By Hop extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // Fragment extension header. + // + // More = 1, Fragment Offset = 2117, ID = 2147746305 + uint8(IPv6RoutingExtHdrIdentifier), 0, 68, 9, 128, 4, 2, 1, + + // Routing extension header. + // + // Even though we have a routing ext header here, it should be + // be interpretted as raw bytes as only the first fragment is expected + // to hold headers. + 255, 0, 1, 2, 3, 4, 5, 6, + + // Upper layer data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6HopByHopOptionsExtHdr{ipv6OptionsExtHdr: []byte{1, 4, 1, 2, 3, 4}}, + IPv6FragmentExtHdr([6]byte{68, 9, 128, 4, 2, 1}), + IPv6RawPayloadHeader{ + Identifier: IPv6RoutingExtHdrIdentifier, + Buf: routingExtHdrWithUpperLayerData.ToVectorisedView(), + }, + }, + }, + { + name: "hopbyhop - fragment (first) - routing - upper", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Hop By Hop extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // Fragment extension header. + // + // More = 1, Fragment Offset = 0, ID = 2147746305 + uint8(IPv6RoutingExtHdrIdentifier), 0, 0, 1, 128, 4, 2, 1, + + // Routing extension header. + 255, 0, 1, 2, 3, 4, 5, 6, + + // Upper layer data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6HopByHopOptionsExtHdr{ipv6OptionsExtHdr: []byte{1, 4, 1, 2, 3, 4}}, + IPv6FragmentExtHdr([6]byte{0, 1, 128, 4, 2, 1}), + IPv6RoutingExtHdr([]byte{1, 2, 3, 4, 5, 6}), + IPv6RawPayloadHeader{ + Identifier: 255, + Buf: upperLayerData.ToVectorisedView(), + }, + }, + }, + { + name: "fragment - routing - upper (across views)", + firstNextHdr: IPv6FragmentExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Fragment extension header. + uint8(IPv6RoutingExtHdrIdentifier), 0, 68, 9, 128, 4, 2, 1, + + // Routing extension header. + 255, 0, 1, 2}, []byte{3, 4, 5, 6, + + // Upper layer data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6FragmentExtHdr([6]byte{68, 9, 128, 4, 2, 1}), + IPv6RawPayloadHeader{ + Identifier: IPv6RoutingExtHdrIdentifier, + Buf: routingExtHdrWithUpperLayerData.ToVectorisedView(), + }, + }, + }, + + // If we have an atomic fragment, the payload following the fragment + // extension header should be parsed normally. + { + name: "atomic fragment - routing - destination - upper", + firstNextHdr: IPv6FragmentExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6RoutingExtHdrIdentifier), 255, 0, 6, 128, 4, 2, 1, + + // Routing extension header. + uint8(IPv6DestinationOptionsExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Destination Options extension header. + 255, 0, 1, 4, 1, 2, 3, 4, + + // Upper layer data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6FragmentExtHdr([6]byte{0, 6, 128, 4, 2, 1}), + IPv6RoutingExtHdr([]byte{1, 2, 3, 4, 5, 6}), + IPv6DestinationOptionsExtHdr{ipv6OptionsExtHdr: []byte{1, 4, 1, 2, 3, 4}}, + IPv6RawPayloadHeader{ + Identifier: 255, + Buf: upperLayerData.ToVectorisedView(), + }, + }, + }, + { + name: "atomic fragment - routing - upper (across views)", + firstNextHdr: IPv6FragmentExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6RoutingExtHdrIdentifier), 255, 0, 6}, []byte{128, 4, 2, 1, + + // Routing extension header. + 255, 0, 1, 2}, []byte{3, 4, 5, 6, + + // Upper layer data. + 1, 2}, []byte{3, 4}), + expected: []IPv6PayloadHeader{ + IPv6FragmentExtHdr([6]byte{0, 6, 128, 4, 2, 1}), + IPv6RoutingExtHdr([]byte{1, 2, 3, 4, 5, 6}), + IPv6RawPayloadHeader{ + Identifier: 255, + Buf: makeVectorisedViewFromByteBuffers(upperLayerData[:2], upperLayerData[2:]), + }, + }, + }, + { + name: "atomic fragment - destination - no next header", + firstNextHdr: IPv6FragmentExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Fragment extension header. + // + // Res (Reserved) bits are 1 which should not affect anything. + uint8(IPv6DestinationOptionsExtHdrIdentifier), 0, 0, 6, 128, 4, 2, 1, + + // Destination Options extension header. + uint8(IPv6NoNextHeaderIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // Random data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6FragmentExtHdr([6]byte{0, 6, 128, 4, 2, 1}), + IPv6DestinationOptionsExtHdr{ipv6OptionsExtHdr: []byte{1, 4, 1, 2, 3, 4}}, + }, + }, + { + name: "routing - atomic fragment - no next header", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Routing extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6NoNextHeaderIdentifier), 0, 0, 6, 128, 4, 2, 1, + + // Random data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6RoutingExtHdr([]byte{1, 2, 3, 4, 5, 6}), + IPv6FragmentExtHdr([6]byte{0, 6, 128, 4, 2, 1}), + }, + }, + { + name: "routing - atomic fragment - no next header (across views)", + firstNextHdr: IPv6RoutingExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Routing extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Fragment extension header. + // + // Reserved bits are 1 which should not affect anything. + uint8(IPv6NoNextHeaderIdentifier), 255, 0, 6}, []byte{128, 4, 2, 1, + + // Random data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6RoutingExtHdr([]byte{1, 2, 3, 4, 5, 6}), + IPv6FragmentExtHdr([6]byte{0, 6, 128, 4, 2, 1}), + }, + }, + { + name: "hopbyhop - routing - fragment - no next header", + firstNextHdr: IPv6HopByHopOptionsExtHdrIdentifier, + payload: makeVectorisedViewFromByteBuffers([]byte{ + // Hop By Hop Options extension header. + uint8(IPv6RoutingExtHdrIdentifier), 0, 1, 4, 1, 2, 3, 4, + + // Routing extension header. + uint8(IPv6FragmentExtHdrIdentifier), 0, 1, 2, 3, 4, 5, 6, + + // Fragment extension header. + // + // Fragment Offset = 32; Res = 6. + uint8(IPv6NoNextHeaderIdentifier), 0, 1, 6, 128, 4, 2, 1, + + // Random data. + 1, 2, 3, 4, + }), + expected: []IPv6PayloadHeader{ + IPv6HopByHopOptionsExtHdr{ipv6OptionsExtHdr: []byte{1, 4, 1, 2, 3, 4}}, + IPv6RoutingExtHdr([]byte{1, 2, 3, 4, 5, 6}), + IPv6FragmentExtHdr([6]byte{1, 6, 128, 4, 2, 1}), + IPv6RawPayloadHeader{ + Identifier: IPv6NoNextHeaderIdentifier, + Buf: upperLayerData.ToVectorisedView(), + }, + }, + }, + + // Test the raw payload for common transport layer protocol numbers. + { + name: "TCP raw payload", + firstNextHdr: IPv6ExtensionHeaderIdentifier(TCPProtocolNumber), + payload: makeVectorisedViewFromByteBuffers(upperLayerData), + expected: []IPv6PayloadHeader{IPv6RawPayloadHeader{ + Identifier: IPv6ExtensionHeaderIdentifier(TCPProtocolNumber), + Buf: upperLayerData.ToVectorisedView(), + }}, + }, + { + name: "UDP raw payload", + firstNextHdr: IPv6ExtensionHeaderIdentifier(UDPProtocolNumber), + payload: makeVectorisedViewFromByteBuffers(upperLayerData), + expected: []IPv6PayloadHeader{IPv6RawPayloadHeader{ + Identifier: IPv6ExtensionHeaderIdentifier(UDPProtocolNumber), + Buf: upperLayerData.ToVectorisedView(), + }}, + }, + { + name: "ICMPv4 raw payload", + firstNextHdr: IPv6ExtensionHeaderIdentifier(ICMPv4ProtocolNumber), + payload: makeVectorisedViewFromByteBuffers(upperLayerData), + expected: []IPv6PayloadHeader{IPv6RawPayloadHeader{ + Identifier: IPv6ExtensionHeaderIdentifier(ICMPv4ProtocolNumber), + Buf: upperLayerData.ToVectorisedView(), + }}, + }, + { + name: "ICMPv6 raw payload", + firstNextHdr: IPv6ExtensionHeaderIdentifier(ICMPv6ProtocolNumber), + payload: makeVectorisedViewFromByteBuffers(upperLayerData), + expected: []IPv6PayloadHeader{IPv6RawPayloadHeader{ + Identifier: IPv6ExtensionHeaderIdentifier(ICMPv6ProtocolNumber), + Buf: upperLayerData.ToVectorisedView(), + }}, + }, + { + name: "Unknwon next header raw payload", + firstNextHdr: 255, + payload: makeVectorisedViewFromByteBuffers(upperLayerData), + expected: []IPv6PayloadHeader{IPv6RawPayloadHeader{ + Identifier: 255, + Buf: upperLayerData.ToVectorisedView(), + }}, + }, + { + name: "Unknwon next header raw payload (across views)", + firstNextHdr: 255, + payload: makeVectorisedViewFromByteBuffers(upperLayerData[:2], upperLayerData[2:]), + expected: []IPv6PayloadHeader{IPv6RawPayloadHeader{ + Identifier: 255, + Buf: makeVectorisedViewFromByteBuffers(upperLayerData[:2], upperLayerData[2:]), + }}, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + it := MakeIPv6PayloadIterator(test.firstNextHdr, test.payload) + + for i, e := range test.expected { + extHdr, done, err := it.Next() + if err != nil { + t.Errorf("(i=%d) Next(): %s", i, err) + } + if done { + t.Errorf("(i=%d) unexpectedly done iterating", i) + } + if diff := cmp.Diff(e, extHdr); diff != "" { + t.Errorf("(i=%d) got ext hdr mismatch (-want +got):\n%s", i, diff) + } + + if t.Failed() { + t.FailNow() + } + } + + extHdr, done, err := it.Next() + if err != nil { + t.Errorf("(last) Next(): %s", err) + } + if !done { + t.Errorf("(last) iterator unexpectedly not done") + } + if extHdr != nil { + t.Errorf("(last) got Next() = %T, want = nil", extHdr) + } + }) + } +} diff --git a/pkg/tcpip/header/ipv6_test.go b/pkg/tcpip/header/ipv6_test.go new file mode 100644 index 000000000..426a873b1 --- /dev/null +++ b/pkg/tcpip/header/ipv6_test.go @@ -0,0 +1,417 @@ +// 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 header_test + +import ( + "bytes" + "crypto/sha256" + "fmt" + "testing" + + "github.com/google/go-cmp/cmp" + "gvisor.dev/gvisor/pkg/rand" + "gvisor.dev/gvisor/pkg/tcpip" + "gvisor.dev/gvisor/pkg/tcpip/header" +) + +const ( + linkAddr = tcpip.LinkAddress("\x02\x02\x03\x04\x05\x06") + linkLocalAddr = tcpip.Address("\xfe\x80\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01") + linkLocalMulticastAddr = tcpip.Address("\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01") + uniqueLocalAddr1 = tcpip.Address("\xfc\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01") + uniqueLocalAddr2 = tcpip.Address("\xfd\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x02") + globalAddr = tcpip.Address("\xa0\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01") +) + +func TestEthernetAdddressToModifiedEUI64(t *testing.T) { + expectedIID := [header.IIDSize]byte{0, 2, 3, 255, 254, 4, 5, 6} + + if diff := cmp.Diff(expectedIID, header.EthernetAddressToModifiedEUI64(linkAddr)); diff != "" { + t.Errorf("EthernetAddressToModifiedEUI64(%s) mismatch (-want +got):\n%s", linkAddr, diff) + } + + var buf [header.IIDSize]byte + header.EthernetAdddressToModifiedEUI64IntoBuf(linkAddr, buf[:]) + if diff := cmp.Diff(expectedIID, buf); diff != "" { + t.Errorf("EthernetAddressToModifiedEUI64IntoBuf(%s, _) mismatch (-want +got):\n%s", linkAddr, diff) + } +} + +func TestLinkLocalAddr(t *testing.T) { + if got, want := header.LinkLocalAddr(linkAddr), tcpip.Address("\xfe\x80\x00\x00\x00\x00\x00\x00\x00\x02\x03\xff\xfe\x04\x05\x06"); got != want { + t.Errorf("got LinkLocalAddr(%s) = %s, want = %s", linkAddr, got, want) + } +} + +func TestAppendOpaqueInterfaceIdentifier(t *testing.T) { + var secretKeyBuf [header.OpaqueIIDSecretKeyMinBytes * 2]byte + if n, err := rand.Read(secretKeyBuf[:]); err != nil { + t.Fatalf("rand.Read(_): %s", err) + } else if want := header.OpaqueIIDSecretKeyMinBytes * 2; n != want { + t.Fatalf("expected rand.Read to read %d bytes, read %d bytes", want, n) + } + + tests := []struct { + name string + prefix tcpip.Subnet + nicName string + dadCounter uint8 + secretKey []byte + }{ + { + name: "SecretKey of minimum size", + prefix: header.IPv6LinkLocalPrefix.Subnet(), + nicName: "eth0", + dadCounter: 0, + secretKey: secretKeyBuf[:header.OpaqueIIDSecretKeyMinBytes], + }, + { + name: "SecretKey of less than minimum size", + prefix: func() tcpip.Subnet { + addrWithPrefix := tcpip.AddressWithPrefix{ + Address: "\x01\x02\x03\x03\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + PrefixLen: header.IIDOffsetInIPv6Address * 8, + } + return addrWithPrefix.Subnet() + }(), + nicName: "eth10", + dadCounter: 1, + secretKey: secretKeyBuf[:header.OpaqueIIDSecretKeyMinBytes/2], + }, + { + name: "SecretKey of more than minimum size", + prefix: func() tcpip.Subnet { + addrWithPrefix := tcpip.AddressWithPrefix{ + Address: "\x01\x02\x03\x04\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + PrefixLen: header.IIDOffsetInIPv6Address * 8, + } + return addrWithPrefix.Subnet() + }(), + nicName: "eth11", + dadCounter: 2, + secretKey: secretKeyBuf[:header.OpaqueIIDSecretKeyMinBytes*2], + }, + { + name: "Nil SecretKey and empty nicName", + prefix: func() tcpip.Subnet { + addrWithPrefix := tcpip.AddressWithPrefix{ + Address: "\x01\x02\x03\x05\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00", + PrefixLen: header.IIDOffsetInIPv6Address * 8, + } + return addrWithPrefix.Subnet() + }(), + nicName: "", + dadCounter: 3, + secretKey: nil, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + h := sha256.New() + h.Write([]byte(test.prefix.ID()[:header.IIDOffsetInIPv6Address])) + h.Write([]byte(test.nicName)) + h.Write([]byte{test.dadCounter}) + if k := test.secretKey; k != nil { + h.Write(k) + } + var hashSum [sha256.Size]byte + h.Sum(hashSum[:0]) + want := hashSum[:header.IIDSize] + + // Passing a nil buffer should result in a new buffer returned with the + // IID. + if got := header.AppendOpaqueInterfaceIdentifier(nil, test.prefix, test.nicName, test.dadCounter, test.secretKey); !bytes.Equal(got, want) { + t.Errorf("got AppendOpaqueInterfaceIdentifier(nil, %s, %s, %d, %x) = %x, want = %x", test.prefix, test.nicName, test.dadCounter, test.secretKey, got, want) + } + + // Passing a buffer with sufficient capacity for the IID should populate + // the buffer provided. + var iidBuf [header.IIDSize]byte + if got := header.AppendOpaqueInterfaceIdentifier(iidBuf[:0], test.prefix, test.nicName, test.dadCounter, test.secretKey); !bytes.Equal(got, want) { + t.Errorf("got AppendOpaqueInterfaceIdentifier(iidBuf[:0], %s, %s, %d, %x) = %x, want = %x", test.prefix, test.nicName, test.dadCounter, test.secretKey, got, want) + } + if got := iidBuf[:]; !bytes.Equal(got, want) { + t.Errorf("got iidBuf = %x, want = %x", got, want) + } + }) + } +} + +func TestLinkLocalAddrWithOpaqueIID(t *testing.T) { + var secretKeyBuf [header.OpaqueIIDSecretKeyMinBytes * 2]byte + if n, err := rand.Read(secretKeyBuf[:]); err != nil { + t.Fatalf("rand.Read(_): %s", err) + } else if want := header.OpaqueIIDSecretKeyMinBytes * 2; n != want { + t.Fatalf("expected rand.Read to read %d bytes, read %d bytes", want, n) + } + + prefix := header.IPv6LinkLocalPrefix.Subnet() + + tests := []struct { + name string + prefix tcpip.Subnet + nicName string + dadCounter uint8 + secretKey []byte + }{ + { + name: "SecretKey of minimum size", + nicName: "eth0", + dadCounter: 0, + secretKey: secretKeyBuf[:header.OpaqueIIDSecretKeyMinBytes], + }, + { + name: "SecretKey of less than minimum size", + nicName: "eth10", + dadCounter: 1, + secretKey: secretKeyBuf[:header.OpaqueIIDSecretKeyMinBytes/2], + }, + { + name: "SecretKey of more than minimum size", + nicName: "eth11", + dadCounter: 2, + secretKey: secretKeyBuf[:header.OpaqueIIDSecretKeyMinBytes*2], + }, + { + name: "Nil SecretKey and empty nicName", + nicName: "", + dadCounter: 3, + secretKey: nil, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + addrBytes := [header.IPv6AddressSize]byte{ + 0: 0xFE, + 1: 0x80, + } + + want := tcpip.Address(header.AppendOpaqueInterfaceIdentifier( + addrBytes[:header.IIDOffsetInIPv6Address], + prefix, + test.nicName, + test.dadCounter, + test.secretKey, + )) + + if got := header.LinkLocalAddrWithOpaqueIID(test.nicName, test.dadCounter, test.secretKey); got != want { + t.Errorf("got LinkLocalAddrWithOpaqueIID(%s, %d, %x) = %s, want = %s", test.nicName, test.dadCounter, test.secretKey, got, want) + } + }) + } +} + +func TestIsV6UniqueLocalAddress(t *testing.T) { + tests := []struct { + name string + addr tcpip.Address + expected bool + }{ + { + name: "Valid Unique 1", + addr: uniqueLocalAddr1, + expected: true, + }, + { + name: "Valid Unique 2", + addr: uniqueLocalAddr1, + expected: true, + }, + { + name: "Link Local", + addr: linkLocalAddr, + expected: false, + }, + { + name: "Global", + addr: globalAddr, + expected: false, + }, + { + name: "IPv4", + addr: "\x01\x02\x03\x04", + expected: false, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + if got := header.IsV6UniqueLocalAddress(test.addr); got != test.expected { + t.Errorf("got header.IsV6UniqueLocalAddress(%s) = %t, want = %t", test.addr, got, test.expected) + } + }) + } +} + +func TestIsV6LinkLocalMulticastAddress(t *testing.T) { + tests := []struct { + name string + addr tcpip.Address + expected bool + }{ + { + name: "Valid Link Local Multicast", + addr: linkLocalMulticastAddr, + expected: true, + }, + { + name: "Valid Link Local Multicast with flags", + addr: "\xff\xf2\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01", + expected: true, + }, + { + name: "Link Local Unicast", + addr: linkLocalAddr, + expected: false, + }, + { + name: "IPv4 Multicast", + addr: "\xe0\x00\x00\x01", + expected: false, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + if got := header.IsV6LinkLocalMulticastAddress(test.addr); got != test.expected { + t.Errorf("got header.IsV6LinkLocalMulticastAddress(%s) = %t, want = %t", test.addr, got, test.expected) + } + }) + } +} + +func TestIsV6LinkLocalAddress(t *testing.T) { + tests := []struct { + name string + addr tcpip.Address + expected bool + }{ + { + name: "Valid Link Local Unicast", + addr: linkLocalAddr, + expected: true, + }, + { + name: "Link Local Multicast", + addr: linkLocalMulticastAddr, + expected: false, + }, + { + name: "Unique Local", + addr: uniqueLocalAddr1, + expected: false, + }, + { + name: "Global", + addr: globalAddr, + expected: false, + }, + { + name: "IPv4 Link Local", + addr: "\xa9\xfe\x00\x01", + expected: false, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + if got := header.IsV6LinkLocalAddress(test.addr); got != test.expected { + t.Errorf("got header.IsV6LinkLocalAddress(%s) = %t, want = %t", test.addr, got, test.expected) + } + }) + } +} + +func TestScopeForIPv6Address(t *testing.T) { + tests := []struct { + name string + addr tcpip.Address + scope header.IPv6AddressScope + err *tcpip.Error + }{ + { + name: "Unique Local", + addr: uniqueLocalAddr1, + scope: header.UniqueLocalScope, + err: nil, + }, + { + name: "Link Local Unicast", + addr: linkLocalAddr, + scope: header.LinkLocalScope, + err: nil, + }, + { + name: "Link Local Multicast", + addr: linkLocalMulticastAddr, + scope: header.LinkLocalScope, + err: nil, + }, + { + name: "Global", + addr: globalAddr, + scope: header.GlobalScope, + err: nil, + }, + { + name: "IPv4", + addr: "\x01\x02\x03\x04", + scope: header.GlobalScope, + err: tcpip.ErrBadAddress, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + got, err := header.ScopeForIPv6Address(test.addr) + if err != test.err { + t.Errorf("got header.IsV6UniqueLocalAddress(%s) = (_, %v), want = (_, %v)", test.addr, err, test.err) + } + if got != test.scope { + t.Errorf("got header.IsV6UniqueLocalAddress(%s) = (%d, _), want = (%d, _)", test.addr, got, test.scope) + } + }) + } +} + +func TestSolicitedNodeAddr(t *testing.T) { + tests := []struct { + addr tcpip.Address + want tcpip.Address + }{ + { + addr: "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\xa0", + want: "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xff\x0e\x0f\xa0", + }, + { + addr: "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\xdd\x0e\x0f\xa0", + want: "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xff\x0e\x0f\xa0", + }, + { + addr: "\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\xdd\x01\x02\x03", + want: "\xff\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\xff\x01\x02\x03", + }, + } + + for _, test := range tests { + t.Run(fmt.Sprintf("%s", test.addr), func(t *testing.T) { + if got := header.SolicitedNodeAddr(test.addr); got != test.want { + t.Fatalf("got header.SolicitedNodeAddr(%s) = %s, want = %s", test.addr, got, test.want) + } + }) + } +} diff --git a/pkg/tcpip/header/ndp_options.go b/pkg/tcpip/header/ndp_options.go index 98310ea23..5d3975c56 100644 --- a/pkg/tcpip/header/ndp_options.go +++ b/pkg/tcpip/header/ndp_options.go @@ -15,24 +15,46 @@ package header import ( + "bytes" "encoding/binary" + "errors" + "fmt" + "io" + "math" "time" "gvisor.dev/gvisor/pkg/tcpip" ) +// NDPOptionIdentifier is an NDP option type identifier. +type NDPOptionIdentifier uint8 + const ( - // NDPTargetLinkLayerAddressOptionType is the type of the Target - // Link-Layer Address option, as per RFC 4861 section 4.6.1. - NDPTargetLinkLayerAddressOptionType = 2 + // NDPSourceLinkLayerAddressOptionType is the type of the Source Link Layer + // Address option, as per RFC 4861 section 4.6.1. + NDPSourceLinkLayerAddressOptionType NDPOptionIdentifier = 1 - // ndpTargetEthernetLinkLayerAddressSize is the size of a Target - // Link Layer Option for an Ethernet address. - ndpTargetEthernetLinkLayerAddressSize = 8 + // NDPTargetLinkLayerAddressOptionType is the type of the Target Link Layer + // Address option, as per RFC 4861 section 4.6.1. + NDPTargetLinkLayerAddressOptionType NDPOptionIdentifier = 2 - // ndpPrefixInformationType is the type of the Prefix Information + // NDPPrefixInformationType is the type of the Prefix Information // option, as per RFC 4861 section 4.6.2. - ndpPrefixInformationType = 3 + NDPPrefixInformationType NDPOptionIdentifier = 3 + + // NDPRecursiveDNSServerOptionType is the type of the Recursive DNS + // Server option, as per RFC 8106 section 5.1. + NDPRecursiveDNSServerOptionType NDPOptionIdentifier = 25 + + // NDPDNSSearchListOptionType is the type of the DNS Search List option, + // as per RFC 8106 section 5.2. + NDPDNSSearchListOptionType = 31 +) + +const ( + // NDPLinkLayerAddressSize is the size of a Source or Target Link Layer + // Address option for an Ethernet address. + NDPLinkLayerAddressSize = 8 // ndpPrefixInformationLength is the expected length, in bytes, of the // body of an NDP Prefix Information option, as per RFC 4861 section @@ -84,10 +106,39 @@ const ( // within an NDPPrefixInformation. ndpPrefixInformationPrefixOffset = 14 - // NDPPrefixInformationInfiniteLifetime is a value that represents - // infinity for the Valid and Preferred Lifetime fields in a NDP Prefix - // Information option. Its value is (2^32 - 1)s = 4294967295s - NDPPrefixInformationInfiniteLifetime = time.Second * 4294967295 + // ndpRecursiveDNSServerLifetimeOffset is the start of the 4-byte + // Lifetime field within an NDPRecursiveDNSServer. + ndpRecursiveDNSServerLifetimeOffset = 2 + + // ndpRecursiveDNSServerAddressesOffset is the start of the addresses + // for IPv6 Recursive DNS Servers within an NDPRecursiveDNSServer. + ndpRecursiveDNSServerAddressesOffset = 6 + + // minNDPRecursiveDNSServerLength is the minimum NDP Recursive DNS Server + // option's body size when it contains at least one IPv6 address, as per + // RFC 8106 section 5.3.1. + minNDPRecursiveDNSServerBodySize = 22 + + // ndpDNSSearchListLifetimeOffset is the start of the 4-byte + // Lifetime field within an NDPDNSSearchList. + ndpDNSSearchListLifetimeOffset = 2 + + // ndpDNSSearchListDomainNamesOffset is the start of the DNS search list + // domain names within an NDPDNSSearchList. + ndpDNSSearchListDomainNamesOffset = 6 + + // minNDPDNSSearchListBodySize is the minimum NDP DNS Search List option's + // body size when it contains at least one domain name, as per RFC 8106 + // section 5.3.1. + minNDPDNSSearchListBodySize = 14 + + // maxDomainNameLabelLength is the maximum length of a domain name + // label, as per RFC 1035 section 3.1. + maxDomainNameLabelLength = 63 + + // maxDomainNameLength is the maximum length of a domain name, including + // label AND label length octet, as per RFC 1035 section 3.1. + maxDomainNameLength = 255 // lengthByteUnits is the multiplier factor for the Length field of an // NDP option. That is, the length field for NDP options is in units of @@ -95,9 +146,158 @@ const ( lengthByteUnits = 8 ) +var ( + // NDPInfiniteLifetime is a value that represents infinity for the + // 4-byte lifetime fields found in various NDP options. Its value is + // (2^32 - 1)s = 4294967295s. + // + // This is a variable instead of a constant so that tests can change + // this value to a smaller value. It should only be modified by tests. + NDPInfiniteLifetime = time.Second * math.MaxUint32 +) + +// NDPOptionIterator is an iterator of NDPOption. +// +// Note, between when an NDPOptionIterator is obtained and last used, no changes +// to the NDPOptions may happen. Doing so may cause undefined and unexpected +// behaviour. It is fine to obtain an NDPOptionIterator, iterate over the first +// few NDPOption then modify the backing NDPOptions so long as the +// NDPOptionIterator obtained before modification is no longer used. +type NDPOptionIterator struct { + opts *bytes.Buffer +} + +// Potential errors when iterating over an NDPOptions. +var ( + ErrNDPOptMalformedBody = errors.New("NDP option has a malformed body") + ErrNDPOptMalformedHeader = errors.New("NDP option has a malformed header") +) + +// Next returns the next element in the backing NDPOptions, or true if we are +// done, or false if an error occured. +// +// The return can be read as option, done, error. Note, option should only be +// used if done is false and error is nil. +func (i *NDPOptionIterator) Next() (NDPOption, bool, error) { + for { + // Do we still have elements to look at? + if i.opts.Len() == 0 { + return nil, true, nil + } + + // Get the Type field. + temp, err := i.opts.ReadByte() + if err != nil { + if err != io.EOF { + // ReadByte should only ever return nil or io.EOF. + panic(fmt.Sprintf("unexpected error when reading the option's Type field: %s", err)) + } + + // We use io.ErrUnexpectedEOF as exhausting the buffer is unexpected once + // we start parsing an option; we expect the buffer to contain enough + // bytes for the whole option. + return nil, true, fmt.Errorf("unexpectedly exhausted buffer when reading the option's Type field: %w", io.ErrUnexpectedEOF) + } + kind := NDPOptionIdentifier(temp) + + // Get the Length field. + length, err := i.opts.ReadByte() + if err != nil { + if err != io.EOF { + panic(fmt.Sprintf("unexpected error when reading the option's Length field for %s: %s", kind, err)) + } + + return nil, true, fmt.Errorf("unexpectedly exhausted buffer when reading the option's Length field for %s: %w", kind, io.ErrUnexpectedEOF) + } + + // This would indicate an erroneous NDP option as the Length field should + // never be 0. + if length == 0 { + return nil, true, fmt.Errorf("zero valued Length field for %s: %w", kind, ErrNDPOptMalformedHeader) + } + + // Get the body. + numBytes := int(length) * lengthByteUnits + numBodyBytes := numBytes - 2 + body := i.opts.Next(numBodyBytes) + if len(body) < numBodyBytes { + return nil, true, fmt.Errorf("unexpectedly exhausted buffer when reading the option's Body for %s: %w", kind, io.ErrUnexpectedEOF) + } + + switch kind { + case NDPSourceLinkLayerAddressOptionType: + return NDPSourceLinkLayerAddressOption(body), false, nil + + case NDPTargetLinkLayerAddressOptionType: + return NDPTargetLinkLayerAddressOption(body), false, nil + + case NDPPrefixInformationType: + // Make sure the length of a Prefix Information option + // body is ndpPrefixInformationLength, as per RFC 4861 + // section 4.6.2. + if numBodyBytes != ndpPrefixInformationLength { + return nil, true, fmt.Errorf("got %d bytes for NDP Prefix Information option's body, expected %d bytes: %w", numBodyBytes, ndpPrefixInformationLength, ErrNDPOptMalformedBody) + } + + return NDPPrefixInformation(body), false, nil + + case NDPRecursiveDNSServerOptionType: + opt := NDPRecursiveDNSServer(body) + if err := opt.checkAddresses(); err != nil { + return nil, true, err + } + + return opt, false, nil + + case NDPDNSSearchListOptionType: + opt := NDPDNSSearchList(body) + if err := opt.checkDomainNames(); err != nil { + return nil, true, err + } + + return opt, false, nil + + default: + // We do not yet recognize the option, just skip for + // now. This is okay because RFC 4861 allows us to + // skip/ignore any unrecognized options. However, + // we MUST recognized all the options in RFC 4861. + // + // TODO(b/141487990): Handle all NDP options as defined + // by RFC 4861. + } + } +} + // NDPOptions is a buffer of NDP options as defined by RFC 4861 section 4.6. type NDPOptions []byte +// Iter returns an iterator of NDPOption. +// +// If check is true, Iter will do an integrity check on the options by iterating +// over it and returning an error if detected. +// +// See NDPOptionIterator for more information. +func (b NDPOptions) Iter(check bool) (NDPOptionIterator, error) { + it := NDPOptionIterator{ + opts: bytes.NewBuffer(b), + } + + if check { + it2 := NDPOptionIterator{ + opts: bytes.NewBuffer(b), + } + + for { + if _, done, err := it2.Next(); err != nil || done { + return it, err + } + } + } + + return it, nil +} + // Serialize serializes the provided list of NDP options into o. // // Note, b must be of sufficient size to hold all the options in s. See @@ -116,7 +316,7 @@ func (b NDPOptions) Serialize(s NDPOptionsSerializer) int { continue } - b[0] = o.Type() + b[0] = byte(o.Type()) // We know this safe because paddedLength would have returned // 0 if o had an invalid length (> 255 * lengthByteUnits). @@ -137,15 +337,17 @@ func (b NDPOptions) Serialize(s NDPOptionsSerializer) int { return done } -// ndpOption is the set of functions to be implemented by all NDP option types. -type ndpOption interface { - // Type returns the type of this ndpOption. - Type() uint8 +// NDPOption is the set of functions to be implemented by all NDP option types. +type NDPOption interface { + fmt.Stringer + + // Type returns the type of the receiver. + Type() NDPOptionIdentifier - // Length returns the length of the body of this ndpOption, in bytes. + // Length returns the length of the body of the receiver, in bytes. Length() int - // serializeInto serializes this ndpOption into the provided byte + // serializeInto serializes the receiver into the provided byte // buffer. // // Note, the caller MUST provide a byte buffer with size of at least @@ -154,15 +356,15 @@ type ndpOption interface { // buffer is not of sufficient size. // // serializeInto will return the number of bytes that was used to - // serialize this ndpOption. Implementers must only use the number of - // bytes required to serialize this ndpOption. Callers MAY provide a + // serialize the receiver. Implementers must only use the number of + // bytes required to serialize the receiver. Callers MAY provide a // larger buffer than required to serialize into. serializeInto([]byte) int } // paddedLength returns the length of o, in bytes, with any padding bytes, if // required. -func paddedLength(o ndpOption) int { +func paddedLength(o NDPOption) int { l := o.Length() if l == 0 { @@ -201,7 +403,7 @@ func paddedLength(o ndpOption) int { } // NDPOptionsSerializer is a serializer for NDP options. -type NDPOptionsSerializer []ndpOption +type NDPOptionsSerializer []NDPOption // Length returns the total number of bytes required to serialize. func (b NDPOptionsSerializer) Length() int { @@ -214,6 +416,46 @@ func (b NDPOptionsSerializer) Length() int { return l } +// NDPSourceLinkLayerAddressOption is the NDP Source Link Layer Option +// as defined by RFC 4861 section 4.6.1. +// +// It is the first X bytes following the NDP option's Type and Length field +// where X is the value in Length multiplied by lengthByteUnits - 2 bytes. +type NDPSourceLinkLayerAddressOption tcpip.LinkAddress + +// Type implements NDPOption.Type. +func (o NDPSourceLinkLayerAddressOption) Type() NDPOptionIdentifier { + return NDPSourceLinkLayerAddressOptionType +} + +// Length implements NDPOption.Length. +func (o NDPSourceLinkLayerAddressOption) Length() int { + return len(o) +} + +// serializeInto implements NDPOption.serializeInto. +func (o NDPSourceLinkLayerAddressOption) serializeInto(b []byte) int { + return copy(b, o) +} + +// String implements fmt.Stringer.String. +func (o NDPSourceLinkLayerAddressOption) String() string { + return fmt.Sprintf("%T(%s)", o, tcpip.LinkAddress(o)) +} + +// EthernetAddress will return an ethernet (MAC) address if the +// NDPSourceLinkLayerAddressOption's body has at minimum EthernetAddressSize +// bytes. If the body has more than EthernetAddressSize bytes, only the first +// EthernetAddressSize bytes are returned as that is all that is needed for an +// Ethernet address. +func (o NDPSourceLinkLayerAddressOption) EthernetAddress() tcpip.LinkAddress { + if len(o) >= EthernetAddressSize { + return tcpip.LinkAddress(o[:EthernetAddressSize]) + } + + return tcpip.LinkAddress([]byte(nil)) +} + // NDPTargetLinkLayerAddressOption is the NDP Target Link Layer Option // as defined by RFC 4861 section 4.6.1. // @@ -221,21 +463,39 @@ func (b NDPOptionsSerializer) Length() int { // where X is the value in Length multiplied by lengthByteUnits - 2 bytes. type NDPTargetLinkLayerAddressOption tcpip.LinkAddress -// Type implements ndpOption.Type. -func (o NDPTargetLinkLayerAddressOption) Type() uint8 { +// Type implements NDPOption.Type. +func (o NDPTargetLinkLayerAddressOption) Type() NDPOptionIdentifier { return NDPTargetLinkLayerAddressOptionType } -// Length implements ndpOption.Length. +// Length implements NDPOption.Length. func (o NDPTargetLinkLayerAddressOption) Length() int { return len(o) } -// serializeInto implements ndpOption.serializeInto. +// serializeInto implements NDPOption.serializeInto. func (o NDPTargetLinkLayerAddressOption) serializeInto(b []byte) int { return copy(b, o) } +// String implements fmt.Stringer.String. +func (o NDPTargetLinkLayerAddressOption) String() string { + return fmt.Sprintf("%T(%s)", o, tcpip.LinkAddress(o)) +} + +// EthernetAddress will return an ethernet (MAC) address if the +// NDPTargetLinkLayerAddressOption's body has at minimum EthernetAddressSize +// bytes. If the body has more than EthernetAddressSize bytes, only the first +// EthernetAddressSize bytes are returned as that is all that is needed for an +// Ethernet address. +func (o NDPTargetLinkLayerAddressOption) EthernetAddress() tcpip.LinkAddress { + if len(o) >= EthernetAddressSize { + return tcpip.LinkAddress(o[:EthernetAddressSize]) + } + + return tcpip.LinkAddress([]byte(nil)) +} + // NDPPrefixInformation is the NDP Prefix Information option as defined by // RFC 4861 section 4.6.2. // @@ -243,17 +503,17 @@ func (o NDPTargetLinkLayerAddressOption) serializeInto(b []byte) int { // ndpPrefixInformationLength bytes. type NDPPrefixInformation []byte -// Type implements ndpOption.Type. -func (o NDPPrefixInformation) Type() uint8 { - return ndpPrefixInformationType +// Type implements NDPOption.Type. +func (o NDPPrefixInformation) Type() NDPOptionIdentifier { + return NDPPrefixInformationType } -// Length implements ndpOption.Length. +// Length implements NDPOption.Length. func (o NDPPrefixInformation) Length() int { return ndpPrefixInformationLength } -// serializeInto implements ndpOption.serializeInto. +// serializeInto implements NDPOption.serializeInto. func (o NDPPrefixInformation) serializeInto(b []byte) int { used := copy(b, o) @@ -269,6 +529,17 @@ func (o NDPPrefixInformation) serializeInto(b []byte) int { return used } +// String implements fmt.Stringer.String. +func (o NDPPrefixInformation) String() string { + return fmt.Sprintf("%T(O=%t, A=%t, PL=%s, VL=%s, Prefix=%s)", + o, + o.OnLinkFlag(), + o.AutonomousAddressConfigurationFlag(), + o.PreferredLifetime(), + o.ValidLifetime(), + o.Subnet()) +} + // PrefixLength returns the value in the number of leading bits in the Prefix // that are valid. // @@ -302,7 +573,7 @@ func (o NDPPrefixInformation) AutonomousAddressConfigurationFlag() bool { // // Note, a value of 0 implies the prefix should not be considered as on-link, // and a value of infinity/forever is represented by -// NDPPrefixInformationInfiniteLifetime. +// NDPInfiniteLifetime. func (o NDPPrefixInformation) ValidLifetime() time.Duration { // The field is the time in seconds, as per RFC 4861 section 4.6.2. return time.Second * time.Duration(binary.BigEndian.Uint32(o[ndpPrefixInformationValidLifetimeOffset:])) @@ -315,7 +586,7 @@ func (o NDPPrefixInformation) ValidLifetime() time.Duration { // // Note, a value of 0 implies that addresses generated from the prefix should // no longer remain preferred, and a value of infinity is represented by -// NDPPrefixInformationInfiniteLifetime. +// NDPInfiniteLifetime. // // Also note that the value of this field MUST NOT exceed the Valid Lifetime // field to avoid preferring addresses that are no longer valid, for the @@ -334,3 +605,295 @@ func (o NDPPrefixInformation) PreferredLifetime() time.Duration { func (o NDPPrefixInformation) Prefix() tcpip.Address { return tcpip.Address(o[ndpPrefixInformationPrefixOffset:][:IPv6AddressSize]) } + +// Subnet returns the Prefix field and Prefix Length field represented in a +// tcpip.Subnet. +func (o NDPPrefixInformation) Subnet() tcpip.Subnet { + addrWithPrefix := tcpip.AddressWithPrefix{ + Address: o.Prefix(), + PrefixLen: int(o.PrefixLength()), + } + return addrWithPrefix.Subnet() +} + +// NDPRecursiveDNSServer is the NDP Recursive DNS Server option, as defined by +// RFC 8106 section 5.1. +// +// To make sure that the option meets its minimum length and does not end in the +// middle of a DNS server's IPv6 address, the length of a valid +// NDPRecursiveDNSServer must meet the following constraint: +// (Length - ndpRecursiveDNSServerAddressesOffset) % IPv6AddressSize == 0 +type NDPRecursiveDNSServer []byte + +// Type returns the type of an NDP Recursive DNS Server option. +// +// Type implements NDPOption.Type. +func (NDPRecursiveDNSServer) Type() NDPOptionIdentifier { + return NDPRecursiveDNSServerOptionType +} + +// Length implements NDPOption.Length. +func (o NDPRecursiveDNSServer) Length() int { + return len(o) +} + +// serializeInto implements NDPOption.serializeInto. +func (o NDPRecursiveDNSServer) serializeInto(b []byte) int { + used := copy(b, o) + + // Zero out the reserved bytes that are before the Lifetime field. + for i := 0; i < ndpRecursiveDNSServerLifetimeOffset; i++ { + b[i] = 0 + } + + return used +} + +// String implements fmt.Stringer.String. +func (o NDPRecursiveDNSServer) String() string { + lt := o.Lifetime() + addrs, err := o.Addresses() + if err != nil { + return fmt.Sprintf("%T([] valid for %s; err = %s)", o, lt, err) + } + return fmt.Sprintf("%T(%s valid for %s)", o, addrs, lt) +} + +// Lifetime returns the length of time that the DNS server addresses +// in this option may be used for name resolution. +// +// Note, a value of 0 implies the addresses should no longer be used, +// and a value of infinity/forever is represented by NDPInfiniteLifetime. +// +// Lifetime may panic if o does not have enough bytes to hold the Lifetime +// field. +func (o NDPRecursiveDNSServer) Lifetime() time.Duration { + // The field is the time in seconds, as per RFC 8106 section 5.1. + return time.Second * time.Duration(binary.BigEndian.Uint32(o[ndpRecursiveDNSServerLifetimeOffset:])) +} + +// Addresses returns the recursive DNS server IPv6 addresses that may be +// used for name resolution. +// +// Note, the addresses MAY be link-local addresses. +func (o NDPRecursiveDNSServer) Addresses() ([]tcpip.Address, error) { + var addrs []tcpip.Address + return addrs, o.iterAddresses(func(addr tcpip.Address) { addrs = append(addrs, addr) }) +} + +// checkAddresses iterates over the addresses in an NDP Recursive DNS Server +// option and returns any error it encounters. +func (o NDPRecursiveDNSServer) checkAddresses() error { + return o.iterAddresses(nil) +} + +// iterAddresses iterates over the addresses in an NDP Recursive DNS Server +// option and calls a function with each valid unicast IPv6 address. +// +// Note, the addresses MAY be link-local addresses. +func (o NDPRecursiveDNSServer) iterAddresses(fn func(tcpip.Address)) error { + if l := len(o); l < minNDPRecursiveDNSServerBodySize { + return fmt.Errorf("got %d bytes for NDP Recursive DNS Server option's body, expected at least %d bytes: %w", l, minNDPRecursiveDNSServerBodySize, io.ErrUnexpectedEOF) + } + + o = o[ndpRecursiveDNSServerAddressesOffset:] + l := len(o) + if l%IPv6AddressSize != 0 { + return fmt.Errorf("NDP Recursive DNS Server option's body ends in the middle of an IPv6 address (addresses body size = %d bytes): %w", l, ErrNDPOptMalformedBody) + } + + for i := 0; len(o) != 0; i++ { + addr := tcpip.Address(o[:IPv6AddressSize]) + if !IsV6UnicastAddress(addr) { + return fmt.Errorf("%d-th address (%s) in NDP Recursive DNS Server option is not a valid unicast IPv6 address: %w", i, addr, ErrNDPOptMalformedBody) + } + + if fn != nil { + fn(addr) + } + + o = o[IPv6AddressSize:] + } + + return nil +} + +// NDPDNSSearchList is the NDP DNS Search List option, as defined by +// RFC 8106 section 5.2. +type NDPDNSSearchList []byte + +// Type implements NDPOption.Type. +func (o NDPDNSSearchList) Type() NDPOptionIdentifier { + return NDPDNSSearchListOptionType +} + +// Length implements NDPOption.Length. +func (o NDPDNSSearchList) Length() int { + return len(o) +} + +// serializeInto implements NDPOption.serializeInto. +func (o NDPDNSSearchList) serializeInto(b []byte) int { + used := copy(b, o) + + // Zero out the reserved bytes that are before the Lifetime field. + for i := 0; i < ndpDNSSearchListLifetimeOffset; i++ { + b[i] = 0 + } + + return used +} + +// String implements fmt.Stringer.String. +func (o NDPDNSSearchList) String() string { + lt := o.Lifetime() + domainNames, err := o.DomainNames() + if err != nil { + return fmt.Sprintf("%T([] valid for %s; err = %s)", o, lt, err) + } + return fmt.Sprintf("%T(%s valid for %s)", o, domainNames, lt) +} + +// Lifetime returns the length of time that the DNS search list of domain names +// in this option may be used for name resolution. +// +// Note, a value of 0 implies the domain names should no longer be used, +// and a value of infinity/forever is represented by NDPInfiniteLifetime. +func (o NDPDNSSearchList) Lifetime() time.Duration { + // The field is the time in seconds, as per RFC 8106 section 5.1. + return time.Second * time.Duration(binary.BigEndian.Uint32(o[ndpDNSSearchListLifetimeOffset:])) +} + +// DomainNames returns a DNS search list of domain names. +// +// DomainNames will parse the backing buffer as outlined by RFC 1035 section +// 3.1 and return a list of strings, with all domain names in lower case. +func (o NDPDNSSearchList) DomainNames() ([]string, error) { + var domainNames []string + return domainNames, o.iterDomainNames(func(domainName string) { domainNames = append(domainNames, domainName) }) +} + +// checkDomainNames iterates over the domain names in an NDP DNS Search List +// option and returns any error it encounters. +func (o NDPDNSSearchList) checkDomainNames() error { + return o.iterDomainNames(nil) +} + +// iterDomainNames iterates over the domain names in an NDP DNS Search List +// option and calls a function with each valid domain name. +func (o NDPDNSSearchList) iterDomainNames(fn func(string)) error { + if l := len(o); l < minNDPDNSSearchListBodySize { + return fmt.Errorf("got %d bytes for NDP DNS Search List option's body, expected at least %d bytes: %w", l, minNDPDNSSearchListBodySize, io.ErrUnexpectedEOF) + } + + var searchList bytes.Reader + searchList.Reset(o[ndpDNSSearchListDomainNamesOffset:]) + + var scratch [maxDomainNameLength]byte + domainName := bytes.NewBuffer(scratch[:]) + + // Parse the domain names, as per RFC 1035 section 3.1. + for searchList.Len() != 0 { + domainName.Reset() + + // Parse a label within a domain name, as per RFC 1035 section 3.1. + for { + // The first byte is the label length. + labelLenByte, err := searchList.ReadByte() + if err != nil { + if err != io.EOF { + // ReadByte should only ever return nil or io.EOF. + panic(fmt.Sprintf("unexpected error when reading a label's length: %s", err)) + } + + // We use io.ErrUnexpectedEOF as exhausting the buffer is unexpected + // once we start parsing a domain name; we expect the buffer to contain + // enough bytes for the whole domain name. + return fmt.Errorf("unexpected exhausted buffer while parsing a new label for a domain from NDP Search List option: %w", io.ErrUnexpectedEOF) + } + labelLen := int(labelLenByte) + + // A zero-length label implies the end of a domain name. + if labelLen == 0 { + // If the domain name is empty or we have no callback function, do + // nothing further with the current domain name. + if domainName.Len() == 0 || fn == nil { + break + } + + // Ignore the trailing period in the parsed domain name. + domainName.Truncate(domainName.Len() - 1) + fn(domainName.String()) + break + } + + // The label's length must not exceed the maximum length for a label. + if labelLen > maxDomainNameLabelLength { + return fmt.Errorf("label length of %d bytes is greater than the max label length of %d bytes for an NDP Search List option: %w", labelLen, maxDomainNameLabelLength, ErrNDPOptMalformedBody) + } + + // The label (and trailing period) must not make the domain name too long. + if labelLen+1 > domainName.Cap()-domainName.Len() { + return fmt.Errorf("label would make an NDP Search List option's domain name longer than the max domain name length of %d bytes: %w", maxDomainNameLength, ErrNDPOptMalformedBody) + } + + // Copy the label and add a trailing period. + for i := 0; i < labelLen; i++ { + b, err := searchList.ReadByte() + if err != nil { + if err != io.EOF { + panic(fmt.Sprintf("unexpected error when reading domain name's label: %s", err)) + } + + return fmt.Errorf("read %d out of %d bytes for a domain name's label from NDP Search List option: %w", i, labelLen, io.ErrUnexpectedEOF) + } + + // As per RFC 1035 section 2.3.1: + // 1) the label must only contain ASCII include letters, digits and + // hyphens + // 2) the first character in a label must be a letter + // 3) the last letter in a label must be a letter or digit + + if !isLetter(b) { + if i == 0 { + return fmt.Errorf("first character of a domain name's label in an NDP Search List option must be a letter, got character code = %d: %w", b, ErrNDPOptMalformedBody) + } + + if b == '-' { + if i == labelLen-1 { + return fmt.Errorf("last character of a domain name's label in an NDP Search List option must not be a hyphen (-): %w", ErrNDPOptMalformedBody) + } + } else if !isDigit(b) { + return fmt.Errorf("domain name's label in an NDP Search List option may only contain letters, digits and hyphens, got character code = %d: %w", b, ErrNDPOptMalformedBody) + } + } + + // If b is an upper case character, make it lower case. + if isUpperLetter(b) { + b = b - 'A' + 'a' + } + + if err := domainName.WriteByte(b); err != nil { + panic(fmt.Sprintf("unexpected error writing label to domain name buffer: %s", err)) + } + } + if err := domainName.WriteByte('.'); err != nil { + panic(fmt.Sprintf("unexpected error writing trailing period to domain name buffer: %s", err)) + } + } + } + + return nil +} + +func isLetter(b byte) bool { + return b >= 'a' && b <= 'z' || isUpperLetter(b) +} + +func isUpperLetter(b byte) bool { + return b >= 'A' && b <= 'Z' +} + +func isDigit(b byte) bool { + return b >= '0' && b <= '9' +} diff --git a/pkg/tcpip/header/ndp_router_solicit.go b/pkg/tcpip/header/ndp_router_solicit.go new file mode 100644 index 000000000..9e67ba95d --- /dev/null +++ b/pkg/tcpip/header/ndp_router_solicit.go @@ -0,0 +1,36 @@ +// 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 header + +// NDPRouterSolicit is an NDP Router Solicitation message. It will only contain +// the body of an ICMPv6 packet. +// +// See RFC 4861 section 4.1 for more details. +type NDPRouterSolicit []byte + +const ( + // NDPRSMinimumSize is the minimum size of a valid NDP Router + // Solicitation message (body of an ICMPv6 packet). + NDPRSMinimumSize = 4 + + // ndpRSOptionsOffset is the start of the NDP options in an + // NDPRouterSolicit. + ndpRSOptionsOffset = 4 +) + +// Options returns an NDPOptions of the the options body. +func (b NDPRouterSolicit) Options() NDPOptions { + return NDPOptions(b[ndpRSOptionsOffset:]) +} diff --git a/pkg/tcpip/header/ndp_test.go b/pkg/tcpip/header/ndp_test.go index 0bbf67a2b..dc4591253 100644 --- a/pkg/tcpip/header/ndp_test.go +++ b/pkg/tcpip/header/ndp_test.go @@ -16,9 +16,14 @@ package header import ( "bytes" + "errors" + "fmt" + "io" + "regexp" "testing" "time" + "github.com/google/go-cmp/cmp" "gvisor.dev/gvisor/pkg/tcpip" ) @@ -36,18 +41,18 @@ func TestNDPNeighborSolicit(t *testing.T) { ns := NDPNeighborSolicit(b) addr := tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10") if got := ns.TargetAddress(); got != addr { - t.Fatalf("got ns.TargetAddress = %s, want %s", got, addr) + t.Errorf("got ns.TargetAddress = %s, want %s", got, addr) } // Test updating the Target Address. addr2 := tcpip.Address("\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x11") ns.SetTargetAddress(addr2) if got := ns.TargetAddress(); got != addr2 { - t.Fatalf("got ns.TargetAddress = %s, want %s", got, addr2) + t.Errorf("got ns.TargetAddress = %s, want %s", got, addr2) } // Make sure the address got updated in the backing buffer. if got := tcpip.Address(b[ndpNSTargetAddessOffset:][:IPv6AddressSize]); got != addr2 { - t.Fatalf("got targetaddress buffer = %s, want %s", got, addr2) + t.Errorf("got targetaddress buffer = %s, want %s", got, addr2) } } @@ -65,56 +70,56 @@ func TestNDPNeighborAdvert(t *testing.T) { na := NDPNeighborAdvert(b) addr := tcpip.Address("\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10") if got := na.TargetAddress(); got != addr { - t.Fatalf("got TargetAddress = %s, want %s", got, addr) + t.Errorf("got TargetAddress = %s, want %s", got, addr) } // Test getting the Router Flag. if got := na.RouterFlag(); !got { - t.Fatalf("got RouterFlag = false, want = true") + t.Errorf("got RouterFlag = false, want = true") } // Test getting the Solicited Flag. if got := na.SolicitedFlag(); got { - t.Fatalf("got SolicitedFlag = true, want = false") + t.Errorf("got SolicitedFlag = true, want = false") } // Test getting the Override Flag. if got := na.OverrideFlag(); !got { - t.Fatalf("got OverrideFlag = false, want = true") + t.Errorf("got OverrideFlag = false, want = true") } // Test updating the Target Address. addr2 := tcpip.Address("\x11\x12\x13\x14\x15\x16\x17\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x11") na.SetTargetAddress(addr2) if got := na.TargetAddress(); got != addr2 { - t.Fatalf("got TargetAddress = %s, want %s", got, addr2) + t.Errorf("got TargetAddress = %s, want %s", got, addr2) } // Make sure the address got updated in the backing buffer. if got := tcpip.Address(b[ndpNATargetAddressOffset:][:IPv6AddressSize]); got != addr2 { - t.Fatalf("got targetaddress buffer = %s, want %s", got, addr2) + t.Errorf("got targetaddress buffer = %s, want %s", got, addr2) } // Test updating the Router Flag. na.SetRouterFlag(false) if got := na.RouterFlag(); got { - t.Fatalf("got RouterFlag = true, want = false") + t.Errorf("got RouterFlag = true, want = false") } // Test updating the Solicited Flag. na.SetSolicitedFlag(true) if got := na.SolicitedFlag(); !got { - t.Fatalf("got SolicitedFlag = false, want = true") + t.Errorf("got SolicitedFlag = false, want = true") } // Test updating the Override Flag. na.SetOverrideFlag(false) if got := na.OverrideFlag(); got { - t.Fatalf("got OverrideFlag = true, want = false") + t.Errorf("got OverrideFlag = true, want = false") } // Make sure flags got updated in the backing buffer. if got := b[ndpNAFlagsOffset]; got != 64 { - t.Fatalf("got flags byte = %d, want = 64") + t.Errorf("got flags byte = %d, want = 64", got) } } @@ -128,27 +133,181 @@ func TestNDPRouterAdvert(t *testing.T) { ra := NDPRouterAdvert(b) if got := ra.CurrHopLimit(); got != 64 { - t.Fatalf("got ra.CurrHopLimit = %d, want = 64", got) + t.Errorf("got ra.CurrHopLimit = %d, want = 64", got) } if got := ra.ManagedAddrConfFlag(); !got { - t.Fatalf("got ManagedAddrConfFlag = false, want = true") + t.Errorf("got ManagedAddrConfFlag = false, want = true") } if got := ra.OtherConfFlag(); got { - t.Fatalf("got OtherConfFlag = true, want = false") + t.Errorf("got OtherConfFlag = true, want = false") } if got, want := ra.RouterLifetime(), time.Second*258; got != want { - t.Fatalf("got ra.RouterLifetime = %d, want = %d", got, want) + t.Errorf("got ra.RouterLifetime = %d, want = %d", got, want) } if got, want := ra.ReachableTime(), time.Millisecond*50595078; got != want { - t.Fatalf("got ra.ReachableTime = %d, want = %d", got, want) + t.Errorf("got ra.ReachableTime = %d, want = %d", got, want) } if got, want := ra.RetransTimer(), time.Millisecond*117967114; got != want { - t.Fatalf("got ra.RetransTimer = %d, want = %d", got, want) + t.Errorf("got ra.RetransTimer = %d, want = %d", got, want) + } +} + +// TestNDPSourceLinkLayerAddressOptionEthernetAddress tests getting the +// Ethernet address from an NDPSourceLinkLayerAddressOption. +func TestNDPSourceLinkLayerAddressOptionEthernetAddress(t *testing.T) { + tests := []struct { + name string + buf []byte + expected tcpip.LinkAddress + }{ + { + "ValidMAC", + []byte{1, 2, 3, 4, 5, 6}, + tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"), + }, + { + "SLLBodyTooShort", + []byte{1, 2, 3, 4, 5}, + tcpip.LinkAddress([]byte(nil)), + }, + { + "SLLBodyLargerThanNeeded", + []byte{1, 2, 3, 4, 5, 6, 7, 8}, + tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"), + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + sll := NDPSourceLinkLayerAddressOption(test.buf) + if got := sll.EthernetAddress(); got != test.expected { + t.Errorf("got sll.EthernetAddress = %s, want = %s", got, test.expected) + } + }) + } +} + +// TestNDPSourceLinkLayerAddressOptionSerialize tests serializing a +// NDPSourceLinkLayerAddressOption. +func TestNDPSourceLinkLayerAddressOptionSerialize(t *testing.T) { + tests := []struct { + name string + buf []byte + expectedBuf []byte + addr tcpip.LinkAddress + }{ + { + "Ethernet", + make([]byte, 8), + []byte{1, 1, 1, 2, 3, 4, 5, 6}, + "\x01\x02\x03\x04\x05\x06", + }, + { + "Padding", + []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1}, + []byte{1, 2, 1, 2, 3, 4, 5, 6, 7, 8, 0, 0, 0, 0, 0, 0}, + "\x01\x02\x03\x04\x05\x06\x07\x08", + }, + { + "Empty", + nil, + nil, + "", + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + opts := NDPOptions(test.buf) + serializer := NDPOptionsSerializer{ + NDPSourceLinkLayerAddressOption(test.addr), + } + if got, want := int(serializer.Length()), len(test.expectedBuf); got != want { + t.Fatalf("got Length = %d, want = %d", got, want) + } + opts.Serialize(serializer) + if !bytes.Equal(test.buf, test.expectedBuf) { + t.Fatalf("got b = %d, want = %d", test.buf, test.expectedBuf) + } + + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + if len(test.expectedBuf) > 0 { + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPSourceLinkLayerAddressOptionType { + t.Fatalf("got Type = %d, want = %d", got, NDPSourceLinkLayerAddressOptionType) + } + sll := next.(NDPSourceLinkLayerAddressOption) + if got, want := []byte(sll), test.expectedBuf[2:]; !bytes.Equal(got, want) { + t.Fatalf("got Next = (%x, _, _), want = (%x, _, _)", got, want) + } + + if got, want := sll.EthernetAddress(), tcpip.LinkAddress(test.expectedBuf[2:][:EthernetAddressSize]); got != want { + t.Errorf("got sll.EthernetAddress = %s, want = %s", got, want) + } + } + + // Iterator should not return anything else. + next, done, err := it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } + }) + } +} + +// TestNDPTargetLinkLayerAddressOptionEthernetAddress tests getting the +// Ethernet address from an NDPTargetLinkLayerAddressOption. +func TestNDPTargetLinkLayerAddressOptionEthernetAddress(t *testing.T) { + tests := []struct { + name string + buf []byte + expected tcpip.LinkAddress + }{ + { + "ValidMAC", + []byte{1, 2, 3, 4, 5, 6}, + tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"), + }, + { + "TLLBodyTooShort", + []byte{1, 2, 3, 4, 5}, + tcpip.LinkAddress([]byte(nil)), + }, + { + "TLLBodyLargerThanNeeded", + []byte{1, 2, 3, 4, 5, 6, 7, 8}, + tcpip.LinkAddress("\x01\x02\x03\x04\x05\x06"), + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + tll := NDPTargetLinkLayerAddressOption(test.buf) + if got := tll.EthernetAddress(); got != test.expected { + t.Errorf("got tll.EthernetAddress = %s, want = %s", got, test.expected) + } + }) } } @@ -175,8 +334,8 @@ func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) { }, { "Empty", - []byte{}, - []byte{}, + nil, + nil, "", }, } @@ -194,6 +353,44 @@ func TestNDPTargetLinkLayerAddressOptionSerialize(t *testing.T) { if !bytes.Equal(test.buf, test.expectedBuf) { t.Fatalf("got b = %d, want = %d", test.buf, test.expectedBuf) } + + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + if len(test.expectedBuf) > 0 { + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPTargetLinkLayerAddressOptionType { + t.Fatalf("got Type = %d, want = %d", got, NDPTargetLinkLayerAddressOptionType) + } + tll := next.(NDPTargetLinkLayerAddressOption) + if got, want := []byte(tll), test.expectedBuf[2:]; !bytes.Equal(got, want) { + t.Fatalf("got Next = (%x, _, _), want = (%x, _, _)", got, want) + } + + if got, want := tll.EthernetAddress(), tcpip.LinkAddress(test.expectedBuf[2:][:EthernetAddressSize]); got != want { + t.Errorf("got tll.EthernetAddress = %s, want = %s", got, want) + } + } + + // Iterator should not return anything else. + next, done, err := it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } }) } } @@ -232,39 +429,1093 @@ func TestNDPPrefixInformationOption(t *testing.T) { t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expectedBuf) } - // First two bytes are the Type and Length fields, which are not part of - // the option body. - pi := NDPPrefixInformation(targetBuf[2:]) + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPPrefixInformationType { + t.Errorf("got Type = %d, want = %d", got, NDPPrefixInformationType) + } + + pi := next.(NDPPrefixInformation) if got := pi.Type(); got != 3 { - t.Fatalf("got Type = %d, want = 3", got) + t.Errorf("got Type = %d, want = 3", got) } if got := pi.Length(); got != 30 { - t.Fatalf("got Length = %d, want = 30", got) + t.Errorf("got Length = %d, want = 30", got) } if got := pi.PrefixLength(); got != 43 { - t.Fatalf("got PrefixLength = %d, want = 43", got) + t.Errorf("got PrefixLength = %d, want = 43", got) } if pi.OnLinkFlag() { - t.Fatalf("got OnLinkFlag = true, want = false") + t.Error("got OnLinkFlag = true, want = false") } if !pi.AutonomousAddressConfigurationFlag() { - t.Fatalf("got AutonomousAddressConfigurationFlag = false, want = true") + t.Error("got AutonomousAddressConfigurationFlag = false, want = true") } if got, want := pi.ValidLifetime(), 16909060*time.Second; got != want { - t.Fatalf("got ValidLifetime = %d, want = %d", got, want) + t.Errorf("got ValidLifetime = %d, want = %d", got, want) } if got, want := pi.PreferredLifetime(), 84281096*time.Second; got != want { - t.Fatalf("got PreferredLifetime = %d, want = %d", got, want) + t.Errorf("got PreferredLifetime = %d, want = %d", got, want) } if got, want := pi.Prefix(), tcpip.Address("\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17\x18"); got != want { - t.Fatalf("got Prefix = %s, want = %s", got, want) + t.Errorf("got Prefix = %s, want = %s", got, want) + } + + // Iterator should not return anything else. + next, done, err = it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } +} + +func TestNDPRecursiveDNSServerOptionSerialize(t *testing.T) { + b := []byte{ + 9, 8, + 1, 2, 4, 8, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + } + targetBuf := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1} + expected := []byte{ + 25, 3, 0, 0, + 1, 2, 4, 8, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + } + opts := NDPOptions(targetBuf) + serializer := NDPOptionsSerializer{ + NDPRecursiveDNSServer(b), + } + if got, want := opts.Serialize(serializer), len(expected); got != want { + t.Errorf("got Serialize = %d, want = %d", got, want) + } + if !bytes.Equal(targetBuf, expected) { + t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expected) + } + + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPRecursiveDNSServerOptionType { + t.Errorf("got Type = %d, want = %d", got, NDPRecursiveDNSServerOptionType) + } + + opt, ok := next.(NDPRecursiveDNSServer) + if !ok { + t.Fatalf("next (type = %T) cannot be casted to an NDPRecursiveDNSServer", next) + } + if got := opt.Type(); got != 25 { + t.Errorf("got Type = %d, want = 31", got) + } + if got := opt.Length(); got != 22 { + t.Errorf("got Length = %d, want = 22", got) + } + if got, want := opt.Lifetime(), 16909320*time.Second; got != want { + t.Errorf("got Lifetime = %s, want = %s", got, want) + } + want := []tcpip.Address{ + "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + } + addrs, err := opt.Addresses() + if err != nil { + t.Errorf("opt.Addresses() = %s", err) + } + if diff := cmp.Diff(addrs, want); diff != "" { + t.Errorf("mismatched addresses (-want +got):\n%s", diff) + } + + // Iterator should not return anything else. + next, done, err = it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } +} + +func TestNDPRecursiveDNSServerOption(t *testing.T) { + tests := []struct { + name string + buf []byte + lifetime time.Duration + addrs []tcpip.Address + }{ + { + "Valid1Addr", + []byte{ + 25, 3, 0, 0, + 0, 0, 0, 0, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + }, + 0, + []tcpip.Address{ + "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + }, + }, + { + "Valid2Addr", + []byte{ + 25, 5, 0, 0, + 0, 0, 0, 0, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + 17, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, + }, + 0, + []tcpip.Address{ + "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + "\x11\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x10", + }, + }, + { + "Valid3Addr", + []byte{ + 25, 7, 0, 0, + 0, 0, 0, 0, + 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, + 17, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 16, + 17, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 17, + }, + 0, + []tcpip.Address{ + "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f", + "\x11\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x10", + "\x11\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x11", + }, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + opts := NDPOptions(test.buf) + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + // Iterator should get our option. + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPRecursiveDNSServerOptionType { + t.Fatalf("got Type = %d, want = %d", got, NDPRecursiveDNSServerOptionType) + } + + opt, ok := next.(NDPRecursiveDNSServer) + if !ok { + t.Fatalf("next (type = %T) cannot be casted to an NDPRecursiveDNSServer", next) + } + if got := opt.Lifetime(); got != test.lifetime { + t.Errorf("got Lifetime = %d, want = %d", got, test.lifetime) + } + addrs, err := opt.Addresses() + if err != nil { + t.Errorf("opt.Addresses() = %s", err) + } + if diff := cmp.Diff(addrs, test.addrs); diff != "" { + t.Errorf("mismatched addresses (-want +got):\n%s", diff) + } + + // Iterator should not return anything else. + next, done, err = it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } + }) + } +} + +// TestNDPDNSSearchListOption tests the getters of NDPDNSSearchList. +func TestNDPDNSSearchListOption(t *testing.T) { + tests := []struct { + name string + buf []byte + lifetime time.Duration + domainNames []string + err error + }{ + { + name: "Valid1Label", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, 'a', 'b', 'c', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: []string{ + "abc", + }, + err: nil, + }, + { + name: "Valid2Label", + buf: []byte{ + 0, 0, + 0, 0, 0, 5, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 0, + 0, 0, 0, 0, 0, 0, + }, + lifetime: 5 * time.Second, + domainNames: []string{ + "abc.abcd", + }, + err: nil, + }, + { + name: "Valid3Label", + buf: []byte{ + 0, 0, + 1, 0, 0, 0, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 1, 'e', + 0, + 0, 0, 0, 0, + }, + lifetime: 16777216 * time.Second, + domainNames: []string{ + "abc.abcd.e", + }, + err: nil, + }, + { + name: "Valid2Domains", + buf: []byte{ + 0, 0, + 1, 2, 3, 4, + 3, 'a', 'b', 'c', + 0, + 2, 'd', 'e', + 3, 'x', 'y', 'z', + 0, + 0, 0, 0, + }, + lifetime: 16909060 * time.Second, + domainNames: []string{ + "abc", + "de.xyz", + }, + err: nil, + }, + { + name: "Valid3DomainsMixedCase", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 3, 'a', 'B', 'c', + 0, + 2, 'd', 'E', + 3, 'X', 'y', 'z', + 0, + 1, 'J', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abc", + "de.xyz", + "j", + }, + err: nil, + }, + { + name: "ValidDomainAfterNULL", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 3, 'a', 'B', 'c', + 0, 0, 0, 0, + 2, 'd', 'E', + 3, 'X', 'y', 'z', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abc", + "de.xyz", + }, + err: nil, + }, + { + name: "Valid0Domains", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 0, + 0, 0, 0, 0, 0, 0, 0, + }, + lifetime: 0, + domainNames: nil, + err: nil, + }, + { + name: "NoTrailingNull", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 7, 'a', 'b', 'c', 'd', 'e', 'f', 'g', + }, + lifetime: 0, + domainNames: nil, + err: io.ErrUnexpectedEOF, + }, + { + name: "IncorrectLength", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 8, 'a', 'b', 'c', 'd', 'e', 'f', 'g', + }, + lifetime: 0, + domainNames: nil, + err: io.ErrUnexpectedEOF, + }, + { + name: "IncorrectLengthWithNULL", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 7, 'a', 'b', 'c', 'd', 'e', 'f', + 0, + }, + lifetime: 0, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "LabelOfLength63", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk", + }, + err: nil, + }, + { + name: "LabelOfLength64", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 64, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', + 0, + }, + lifetime: 0, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "DomainNameOfLength255", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 62, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', + 0, + }, + lifetime: 0, + domainNames: []string{ + "abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijk.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghij", + }, + err: nil, + }, + { + name: "DomainNameOfLength256", + buf: []byte{ + 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 0, + }, + lifetime: 0, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "StartingDigitForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, '9', 'b', 'c', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "StartingHyphenForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, '-', 'b', 'c', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "EndingHyphenForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, 'a', 'b', '-', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: nil, + err: ErrNDPOptMalformedBody, + }, + { + name: "EndingDigitForLabel", + buf: []byte{ + 0, 0, + 0, 0, 0, 1, + 3, 'a', 'b', '9', + 0, + 0, 0, 0, + }, + lifetime: time.Second, + domainNames: []string{ + "ab9", + }, + err: nil, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + opt := NDPDNSSearchList(test.buf) + + if got := opt.Lifetime(); got != test.lifetime { + t.Errorf("got Lifetime = %d, want = %d", got, test.lifetime) + } + domainNames, err := opt.DomainNames() + if !errors.Is(err, test.err) { + t.Errorf("opt.DomainNames() = %s", err) + } + if diff := cmp.Diff(domainNames, test.domainNames); diff != "" { + t.Errorf("mismatched domain names (-want +got):\n%s", diff) + } + }) + } +} + +func TestNDPSearchListOptionDomainNameLabelInvalidSymbols(t *testing.T) { + for r := rune(0); r <= 255; r++ { + t.Run(fmt.Sprintf("RuneVal=%d", r), func(t *testing.T) { + buf := []byte{ + 0, 0, + 0, 0, 0, 0, + 3, 'a', 0 /* will be replaced */, 'c', + 0, + 0, 0, 0, + } + buf[8] = uint8(r) + opt := NDPDNSSearchList(buf) + + // As per RFC 1035 section 2.3.1, the label must only include ASCII + // letters, digits and hyphens (a-z, A-Z, 0-9, -). + var expectedErr error + re := regexp.MustCompile(`[a-zA-Z0-9-]`) + if !re.Match([]byte{byte(r)}) { + expectedErr = ErrNDPOptMalformedBody + } + + if domainNames, err := opt.DomainNames(); !errors.Is(err, expectedErr) { + t.Errorf("got opt.DomainNames() = (%s, %v), want = (_, %v)", domainNames, err, ErrNDPOptMalformedBody) + } + }) + } +} + +func TestNDPDNSSearchListOptionSerialize(t *testing.T) { + b := []byte{ + 9, 8, + 1, 0, 0, 0, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 1, 'e', + 0, + } + targetBuf := []byte{1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1} + expected := []byte{ + 31, 3, 0, 0, + 1, 0, 0, 0, + 3, 'a', 'b', 'c', + 4, 'a', 'b', 'c', 'd', + 1, 'e', + 0, + 0, 0, 0, 0, + } + opts := NDPOptions(targetBuf) + serializer := NDPOptionsSerializer{ + NDPDNSSearchList(b), + } + if got, want := opts.Serialize(serializer), len(expected); got != want { + t.Errorf("got Serialize = %d, want = %d", got, want) + } + if !bytes.Equal(targetBuf, expected) { + t.Fatalf("got targetBuf = %x, want = %x", targetBuf, expected) + } + + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got := next.Type(); got != NDPDNSSearchListOptionType { + t.Errorf("got Type = %d, want = %d", got, NDPDNSSearchListOptionType) + } + + opt, ok := next.(NDPDNSSearchList) + if !ok { + t.Fatalf("next (type = %T) cannot be casted to an NDPDNSSearchList", next) + } + if got := opt.Type(); got != 31 { + t.Errorf("got Type = %d, want = 31", got) + } + if got := opt.Length(); got != 22 { + t.Errorf("got Length = %d, want = 22", got) + } + if got, want := opt.Lifetime(), 16777216*time.Second; got != want { + t.Errorf("got Lifetime = %s, want = %s", got, want) + } + domainNames, err := opt.DomainNames() + if err != nil { + t.Errorf("opt.DomainNames() = %s", err) + } + if diff := cmp.Diff(domainNames, []string{"abc.abcd.e"}); diff != "" { + t.Errorf("domain names mismatch (-want +got):\n%s", diff) + } + + // Iterator should not return anything else. + next, done, err = it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) + } +} + +// TestNDPOptionsIterCheck tests that Iter will return false if the NDPOptions +// the iterator was returned for is malformed. +func TestNDPOptionsIterCheck(t *testing.T) { + tests := []struct { + name string + buf []byte + expectedErr error + }{ + { + name: "ZeroLengthField", + buf: []byte{0, 0, 0, 0, 0, 0, 0, 0}, + expectedErr: ErrNDPOptMalformedHeader, + }, + { + name: "ValidSourceLinkLayerAddressOption", + buf: []byte{1, 1, 1, 2, 3, 4, 5, 6}, + expectedErr: nil, + }, + { + name: "TooSmallSourceLinkLayerAddressOption", + buf: []byte{1, 1, 1, 2, 3, 4, 5}, + expectedErr: io.ErrUnexpectedEOF, + }, + { + name: "ValidTargetLinkLayerAddressOption", + buf: []byte{2, 1, 1, 2, 3, 4, 5, 6}, + expectedErr: nil, + }, + { + name: "TooSmallTargetLinkLayerAddressOption", + buf: []byte{2, 1, 1, 2, 3, 4, 5}, + expectedErr: io.ErrUnexpectedEOF, + }, + { + name: "ValidPrefixInformation", + buf: []byte{ + 3, 4, 43, 64, + 1, 2, 3, 4, + 5, 6, 7, 8, + 0, 0, 0, 0, + 9, 10, 11, 12, + 13, 14, 15, 16, + 17, 18, 19, 20, + 21, 22, 23, 24, + }, + expectedErr: nil, + }, + { + name: "TooSmallPrefixInformation", + buf: []byte{ + 3, 4, 43, 64, + 1, 2, 3, 4, + 5, 6, 7, 8, + 0, 0, 0, 0, + 9, 10, 11, 12, + 13, 14, 15, 16, + 17, 18, 19, 20, + 21, 22, 23, + }, + expectedErr: io.ErrUnexpectedEOF, + }, + { + name: "InvalidPrefixInformationLength", + buf: []byte{ + 3, 3, 43, 64, + 1, 2, 3, 4, + 5, 6, 7, 8, + 0, 0, 0, 0, + 9, 10, 11, 12, + 13, 14, 15, 16, + }, + expectedErr: ErrNDPOptMalformedBody, + }, + { + name: "ValidSourceAndTargetLinkLayerAddressWithPrefixInformation", + buf: []byte{ + // Source Link-Layer Address. + 1, 1, 1, 2, 3, 4, 5, 6, + + // Target Link-Layer Address. + 2, 1, 7, 8, 9, 10, 11, 12, + + // Prefix information. + 3, 4, 43, 64, + 1, 2, 3, 4, + 5, 6, 7, 8, + 0, 0, 0, 0, + 9, 10, 11, 12, + 13, 14, 15, 16, + 17, 18, 19, 20, + 21, 22, 23, 24, + }, + expectedErr: nil, + }, + { + name: "ValidSourceAndTargetLinkLayerAddressWithPrefixInformationWithUnrecognized", + buf: []byte{ + // Source Link-Layer Address. + 1, 1, 1, 2, 3, 4, 5, 6, + + // Target Link-Layer Address. + 2, 1, 7, 8, 9, 10, 11, 12, + + // 255 is an unrecognized type. If 255 ends up + // being the type for some recognized type, + // update 255 to some other unrecognized value. + 255, 2, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 8, + + // Prefix information. + 3, 4, 43, 64, + 1, 2, 3, 4, + 5, 6, 7, 8, + 0, 0, 0, 0, + 9, 10, 11, 12, + 13, 14, 15, 16, + 17, 18, 19, 20, + 21, 22, 23, 24, + }, + expectedErr: nil, + }, + { + name: "InvalidRecursiveDNSServerCutsOffAddress", + buf: []byte{ + 25, 4, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, + 0, 1, 2, 3, 4, 5, 6, 7, + }, + expectedErr: ErrNDPOptMalformedBody, + }, + { + name: "InvalidRecursiveDNSServerInvalidLengthField", + buf: []byte{ + 25, 2, 0, 0, + 0, 0, 0, 0, + 0, 1, 2, 3, 4, 5, 6, 7, 8, + }, + expectedErr: io.ErrUnexpectedEOF, + }, + { + name: "RecursiveDNSServerTooSmall", + buf: []byte{ + 25, 1, 0, 0, + 0, 0, 0, + }, + expectedErr: io.ErrUnexpectedEOF, + }, + { + name: "RecursiveDNSServerMulticast", + buf: []byte{ + 25, 3, 0, 0, + 0, 0, 0, 0, + 255, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, + }, + expectedErr: ErrNDPOptMalformedBody, + }, + { + name: "RecursiveDNSServerUnspecified", + buf: []byte{ + 25, 3, 0, 0, + 0, 0, 0, 0, + 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, + }, + expectedErr: ErrNDPOptMalformedBody, + }, + { + name: "DNSSearchListLargeCompliantRFC1035", + buf: []byte{ + 31, 33, 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 62, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', + 0, + }, + expectedErr: nil, + }, + { + name: "DNSSearchListNonCompliantRFC1035", + buf: []byte{ + 31, 33, 0, 0, + 0, 0, 0, 0, + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 63, 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q', + 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', + 'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', + 'i', 'j', 'k', + 0, + 0, 0, 0, 0, 0, 0, 0, 0, + }, + expectedErr: ErrNDPOptMalformedBody, + }, + { + name: "DNSSearchListValidSmall", + buf: []byte{ + 31, 2, 0, 0, + 0, 0, 0, 0, + 6, 'a', 'b', 'c', 'd', 'e', 'f', + 0, + }, + expectedErr: nil, + }, + { + name: "DNSSearchListTooSmall", + buf: []byte{ + 31, 1, 0, 0, + 0, 0, 0, + }, + expectedErr: io.ErrUnexpectedEOF, + }, + } + + for _, test := range tests { + t.Run(test.name, func(t *testing.T) { + opts := NDPOptions(test.buf) + + if _, err := opts.Iter(true); !errors.Is(err, test.expectedErr) { + t.Fatalf("got Iter(true) = (_, %v), want = (_, %v)", err, test.expectedErr) + } + + // test.buf may be malformed but we chose not to check + // the iterator so it must return true. + if _, err := opts.Iter(false); err != nil { + t.Fatalf("got Iter(false) = (_, %s), want = (_, nil)", err) + } + }) + } +} + +// TestNDPOptionsIter tests that we can iterator over a valid NDPOptions. Note, +// this test does not actually check any of the option's getters, it simply +// checks the option Type and Body. We have other tests that tests the option +// field gettings given an option body and don't need to duplicate those tests +// here. +func TestNDPOptionsIter(t *testing.T) { + buf := []byte{ + // Source Link-Layer Address. + 1, 1, 1, 2, 3, 4, 5, 6, + + // Target Link-Layer Address. + 2, 1, 7, 8, 9, 10, 11, 12, + + // 255 is an unrecognized type. If 255 ends up being the type + // for some recognized type, update 255 to some other + // unrecognized value. Note, this option should be skipped when + // iterating. + 255, 2, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 8, + + // Prefix information. + 3, 4, 43, 64, + 1, 2, 3, 4, + 5, 6, 7, 8, + 0, 0, 0, 0, + 9, 10, 11, 12, + 13, 14, 15, 16, + 17, 18, 19, 20, + 21, 22, 23, 24, + } + + opts := NDPOptions(buf) + it, err := opts.Iter(true) + if err != nil { + t.Fatalf("got Iter = (_, %s), want = (_, nil)", err) + } + + // Test the first (Source Link-Layer) option. + next, done, err := it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got, want := []byte(next.(NDPSourceLinkLayerAddressOption)), buf[2:][:6]; !bytes.Equal(got, want) { + t.Errorf("got Next = (%x, _, _), want = (%x, _, _)", got, want) + } + if got := next.Type(); got != NDPSourceLinkLayerAddressOptionType { + t.Errorf("got Type = %d, want = %d", got, NDPSourceLinkLayerAddressOptionType) + } + + // Test the next (Target Link-Layer) option. + next, done, err = it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got, want := []byte(next.(NDPTargetLinkLayerAddressOption)), buf[10:][:6]; !bytes.Equal(got, want) { + t.Errorf("got Next = (%x, _, _), want = (%x, _, _)", got, want) + } + if got := next.Type(); got != NDPTargetLinkLayerAddressOptionType { + t.Errorf("got Type = %d, want = %d", got, NDPTargetLinkLayerAddressOptionType) + } + + // Test the next (Prefix Information) option. + // Note, the unrecognized option should be skipped. + next, done, err = it.Next() + if err != nil { + t.Fatalf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if done { + t.Fatal("got Next = (_, true, _), want = (_, false, _)") + } + if got, want := next.(NDPPrefixInformation), buf[34:][:30]; !bytes.Equal(got, want) { + t.Errorf("got Next = (%x, _, _), want = (%x, _, _)", got, want) + } + if got := next.Type(); got != NDPPrefixInformationType { + t.Errorf("got Type = %d, want = %d", got, NDPPrefixInformationType) + } + + // Iterator should not return anything else. + next, done, err = it.Next() + if err != nil { + t.Errorf("got Next = (_, _, %s), want = (_, _, nil)", err) + } + if !done { + t.Error("got Next = (_, false, _), want = (_, true, _)") + } + if next != nil { + t.Errorf("got Next = (%x, _, _), want = (nil, _, _)", next) } } diff --git a/pkg/tcpip/header/ndpoptionidentifier_string.go b/pkg/tcpip/header/ndpoptionidentifier_string.go new file mode 100644 index 000000000..6fe9a336b --- /dev/null +++ b/pkg/tcpip/header/ndpoptionidentifier_string.go @@ -0,0 +1,50 @@ +// 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 NDPOptionIdentifier ."; DO NOT EDIT. + +package header + +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[NDPSourceLinkLayerAddressOptionType-1] + _ = x[NDPTargetLinkLayerAddressOptionType-2] + _ = x[NDPPrefixInformationType-3] + _ = x[NDPRecursiveDNSServerOptionType-25] +} + +const ( + _NDPOptionIdentifier_name_0 = "NDPSourceLinkLayerAddressOptionTypeNDPTargetLinkLayerAddressOptionTypeNDPPrefixInformationType" + _NDPOptionIdentifier_name_1 = "NDPRecursiveDNSServerOptionType" +) + +var ( + _NDPOptionIdentifier_index_0 = [...]uint8{0, 35, 70, 94} +) + +func (i NDPOptionIdentifier) String() string { + switch { + case 1 <= i && i <= 3: + i -= 1 + return _NDPOptionIdentifier_name_0[_NDPOptionIdentifier_index_0[i]:_NDPOptionIdentifier_index_0[i+1]] + case i == 25: + return _NDPOptionIdentifier_name_1 + default: + return "NDPOptionIdentifier(" + strconv.FormatInt(int64(i), 10) + ")" + } +} diff --git a/pkg/tcpip/header/tcp.go b/pkg/tcpip/header/tcp.go index 82cfe785c..4c6f808e5 100644 --- a/pkg/tcpip/header/tcp.go +++ b/pkg/tcpip/header/tcp.go @@ -66,6 +66,14 @@ const ( TCPOptionSACK = 5 ) +// Option Lengths. +const ( + TCPOptionMSSLength = 4 + TCPOptionTSLength = 10 + TCPOptionWSLength = 3 + TCPOptionSackPermittedLength = 2 +) + // TCPFields contains the fields of a TCP packet. It is used to describe the // fields of a packet that needs to be encoded. type TCPFields struct { @@ -81,7 +89,8 @@ type TCPFields struct { // AckNum is the "acknowledgement number" field of a TCP packet. AckNum uint32 - // DataOffset is the "data offset" field of a TCP packet. + // DataOffset is the "data offset" field of a TCP packet. It is the length of + // the TCP header in bytes. DataOffset uint8 // Flags is the "flags" field of a TCP packet. @@ -213,7 +222,8 @@ func (b TCP) AckNumber() uint32 { return binary.BigEndian.Uint32(b[TCPAckNumOffset:]) } -// DataOffset returns the "data offset" field of the tcp header. +// DataOffset returns the "data offset" field of the tcp header. The return +// value is the length of the TCP header in bytes. func (b TCP) DataOffset() uint8 { return (b[TCPDataOffset] >> 4) * 4 } @@ -238,6 +248,11 @@ func (b TCP) Checksum() uint16 { return binary.BigEndian.Uint16(b[TCPChecksumOffset:]) } +// UrgentPointer returns the "urgent pointer" field of the tcp header. +func (b TCP) UrgentPointer() uint16 { + return binary.BigEndian.Uint16(b[TCPUrgentPtrOffset:]) +} + // SetSourcePort sets the "source port" field of the tcp header. func (b TCP) SetSourcePort(port uint16) { binary.BigEndian.PutUint16(b[TCPSrcPortOffset:], port) @@ -253,6 +268,37 @@ func (b TCP) SetChecksum(checksum uint16) { binary.BigEndian.PutUint16(b[TCPChecksumOffset:], checksum) } +// SetDataOffset sets the data offset field of the tcp header. headerLen should +// be the length of the TCP header in bytes. +func (b TCP) SetDataOffset(headerLen uint8) { + b[TCPDataOffset] = (headerLen / 4) << 4 +} + +// SetSequenceNumber sets the sequence number field of the tcp header. +func (b TCP) SetSequenceNumber(seqNum uint32) { + binary.BigEndian.PutUint32(b[TCPSeqNumOffset:], seqNum) +} + +// SetAckNumber sets the ack number field of the tcp header. +func (b TCP) SetAckNumber(ackNum uint32) { + binary.BigEndian.PutUint32(b[TCPAckNumOffset:], ackNum) +} + +// SetFlags sets the flags field of the tcp header. +func (b TCP) SetFlags(flags uint8) { + b[TCPFlagsOffset] = flags +} + +// SetWindowSize sets the window size field of the tcp header. +func (b TCP) SetWindowSize(rcvwnd uint16) { + binary.BigEndian.PutUint16(b[TCPWinSizeOffset:], rcvwnd) +} + +// SetUrgentPoiner sets the window size field of the tcp header. +func (b TCP) SetUrgentPoiner(urgentPointer uint16) { + binary.BigEndian.PutUint16(b[TCPUrgentPtrOffset:], urgentPointer) +} + // CalculateChecksum calculates the checksum of the tcp segment. // partialChecksum is the checksum of the network-layer pseudo-header // and the checksum of the segment data. @@ -456,14 +502,11 @@ func ParseTCPOptions(b []byte) TCPOptions { // returns without encoding anything. It returns the number of bytes written to // the provided buffer. func EncodeMSSOption(mss uint32, b []byte) int { - // mssOptionSize is the number of bytes in a valid MSS option. - const mssOptionSize = 4 - - if len(b) < mssOptionSize { + if len(b) < TCPOptionMSSLength { return 0 } - b[0], b[1], b[2], b[3] = TCPOptionMSS, mssOptionSize, byte(mss>>8), byte(mss) - return mssOptionSize + b[0], b[1], b[2], b[3] = TCPOptionMSS, TCPOptionMSSLength, byte(mss>>8), byte(mss) + return TCPOptionMSSLength } // EncodeWSOption encodes the WS TCP option with the WS value in the @@ -471,10 +514,10 @@ func EncodeMSSOption(mss uint32, b []byte) int { // returns without encoding anything. It returns the number of bytes written to // the provided buffer. func EncodeWSOption(ws int, b []byte) int { - if len(b) < 3 { + if len(b) < TCPOptionWSLength { return 0 } - b[0], b[1], b[2] = TCPOptionWS, 3, uint8(ws) + b[0], b[1], b[2] = TCPOptionWS, TCPOptionWSLength, uint8(ws) return int(b[1]) } @@ -483,10 +526,10 @@ func EncodeWSOption(ws int, b []byte) int { // just returns without encoding anything. It returns the number of bytes // written to the provided buffer. func EncodeTSOption(tsVal, tsEcr uint32, b []byte) int { - if len(b) < 10 { + if len(b) < TCPOptionTSLength { return 0 } - b[0], b[1] = TCPOptionTS, 10 + b[0], b[1] = TCPOptionTS, TCPOptionTSLength binary.BigEndian.PutUint32(b[2:], tsVal) binary.BigEndian.PutUint32(b[6:], tsEcr) return int(b[1]) @@ -497,11 +540,11 @@ func EncodeTSOption(tsVal, tsEcr uint32, b []byte) int { // encoding anything. It returns the number of bytes written to the provided // buffer. func EncodeSACKPermittedOption(b []byte) int { - if len(b) < 2 { + if len(b) < TCPOptionSackPermittedLength { return 0 } - b[0], b[1] = TCPOptionSACKPermitted, 2 + b[0], b[1] = TCPOptionSACKPermitted, TCPOptionSackPermittedLength return int(b[1]) } @@ -556,3 +599,23 @@ func AddTCPOptionPadding(options []byte, offset int) int { } return paddingToAdd } + +// Acceptable checks if a segment that starts at segSeq and has length segLen is +// "acceptable" for arriving in a receive window that starts at rcvNxt and ends +// before rcvAcc, according to the table on page 26 and 69 of RFC 793. +func Acceptable(segSeq seqnum.Value, segLen seqnum.Size, rcvNxt, rcvAcc seqnum.Value) bool { + if rcvNxt == rcvAcc { + return segLen == 0 && segSeq == rcvNxt + } + if segLen == 0 { + // rcvWnd is incremented by 1 because that is Linux's behavior despite the + // RFC. + return segSeq.InRange(rcvNxt, rcvAcc.Add(1)) + } + // Page 70 of RFC 793 allows packets that can be made "acceptable" by trimming + // the payload, so we'll accept any payload that overlaps the receieve window. + // segSeq < rcvAcc is more correct according to RFC, however, Linux does it + // differently, it uses segSeq <= rcvAcc, we'd want to keep the same behavior + // as Linux. + return rcvNxt.LessThan(segSeq.Add(segLen)) && segSeq.LessThanEq(rcvAcc) +} diff --git a/pkg/tcpip/header/udp.go b/pkg/tcpip/header/udp.go index 74412c894..9339d637f 100644 --- a/pkg/tcpip/header/udp.go +++ b/pkg/tcpip/header/udp.go @@ -99,6 +99,11 @@ func (b UDP) SetChecksum(checksum uint16) { binary.BigEndian.PutUint16(b[udpChecksum:], checksum) } +// SetLength sets the "length" field of the udp header. +func (b UDP) SetLength(length uint16) { + binary.BigEndian.PutUint16(b[udpLength:], length) +} + // CalculateChecksum calculates the checksum of the udp packet, given the // checksum of the network-layer pseudo-header and the checksum of the payload. func (b UDP) CalculateChecksum(partialChecksum uint16) uint16 { |