diff options
-rw-r--r-- | pkg/tcpip/network/ipv4/icmp.go | 89 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 28 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv4/ipv4_test.go | 136 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/BUILD | 1 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 77 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/icmp_test.go | 3 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 33 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ipv6_test.go | 146 |
8 files changed, 420 insertions, 93 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go index 2aa38eb98..d51c36f19 100644 --- a/pkg/tcpip/network/ipv4/icmp.go +++ b/pkg/tcpip/network/ipv4/icmp.go @@ -240,12 +240,6 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { case header.ICMPv4Echo: received.echoRequest.Increment() - sent := e.stats.icmp.packetsSent - if !e.protocol.stack.AllowICMPMessage() { - sent.rateLimited.Increment() - return - } - // DeliverTransportPacket will take ownership of pkt so don't use it beyond // this point. Make a deep copy of the data before pkt gets sent as we will // be modifying fields. @@ -281,6 +275,12 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { } defer r.Release() + sent := e.stats.icmp.packetsSent + if !e.protocol.allowICMPReply(header.ICMPv4EchoReply, header.ICMPv4UnusedCode) { + sent.rateLimited.Increment() + return + } + // TODO(gvisor.dev/issue/3810:) When adding protocol numbers into the // header information, we may have to change this code to handle the // ICMP header no longer being in the data buffer. @@ -562,13 +562,6 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip return &tcpip.ErrNotConnected{} } - sent := netEP.stats.icmp.packetsSent - - if !p.stack.AllowICMPMessage() { - sent.rateLimited.Increment() - return nil - } - transportHeader := pkt.TransportHeader().View() // Don't respond to icmp error packets. @@ -606,6 +599,35 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip } } + sent := netEP.stats.icmp.packetsSent + icmpType, icmpCode, counter, pointer := func() (header.ICMPv4Type, header.ICMPv4Code, tcpip.MultiCounterStat, byte) { + switch reason := reason.(type) { + case *icmpReasonPortUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4PortUnreachable, sent.dstUnreachable, 0 + case *icmpReasonProtoUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4ProtoUnreachable, sent.dstUnreachable, 0 + case *icmpReasonNetworkUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4NetUnreachable, sent.dstUnreachable, 0 + case *icmpReasonHostUnreachable: + return header.ICMPv4DstUnreachable, header.ICMPv4HostUnreachable, sent.dstUnreachable, 0 + case *icmpReasonFragmentationNeeded: + return header.ICMPv4DstUnreachable, header.ICMPv4FragmentationNeeded, sent.dstUnreachable, 0 + case *icmpReasonTTLExceeded: + return header.ICMPv4TimeExceeded, header.ICMPv4TTLExceeded, sent.timeExceeded, 0 + case *icmpReasonReassemblyTimeout: + return header.ICMPv4TimeExceeded, header.ICMPv4ReassemblyTimeout, sent.timeExceeded, 0 + case *icmpReasonParamProblem: + return header.ICMPv4ParamProblem, header.ICMPv4UnusedCode, sent.paramProblem, reason.pointer + default: + panic(fmt.Sprintf("unsupported ICMP type %T", reason)) + } + }() + + if !p.allowICMPReply(icmpType, icmpCode) { + sent.rateLimited.Increment() + return nil + } + // Now work out how much of the triggering packet we should return. // As per RFC 1812 Section 4.3.2.3 // @@ -658,44 +680,9 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip icmpPkt.TransportProtocolNumber = header.ICMPv4ProtocolNumber icmpHdr := header.ICMPv4(icmpPkt.TransportHeader().Push(header.ICMPv4MinimumSize)) - var counter tcpip.MultiCounterStat - switch reason := reason.(type) { - case *icmpReasonPortUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4PortUnreachable) - counter = sent.dstUnreachable - case *icmpReasonProtoUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4ProtoUnreachable) - counter = sent.dstUnreachable - case *icmpReasonNetworkUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4NetUnreachable) - counter = sent.dstUnreachable - case *icmpReasonHostUnreachable: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4HostUnreachable) - counter = sent.dstUnreachable - case *icmpReasonFragmentationNeeded: - icmpHdr.SetType(header.ICMPv4DstUnreachable) - icmpHdr.SetCode(header.ICMPv4FragmentationNeeded) - counter = sent.dstUnreachable - case *icmpReasonTTLExceeded: - icmpHdr.SetType(header.ICMPv4TimeExceeded) - icmpHdr.SetCode(header.ICMPv4TTLExceeded) - counter = sent.timeExceeded - case *icmpReasonReassemblyTimeout: - icmpHdr.SetType(header.ICMPv4TimeExceeded) - icmpHdr.SetCode(header.ICMPv4ReassemblyTimeout) - counter = sent.timeExceeded - case *icmpReasonParamProblem: - icmpHdr.SetType(header.ICMPv4ParamProblem) - icmpHdr.SetCode(header.ICMPv4UnusedCode) - icmpHdr.SetPointer(reason.pointer) - counter = sent.paramProblem - default: - panic(fmt.Sprintf("unsupported ICMP type %T", reason)) - } + icmpHdr.SetCode(icmpCode) + icmpHdr.SetType(icmpType) + icmpHdr.SetPointer(pointer) icmpHdr.SetChecksum(header.ICMPv4Checksum(icmpHdr, icmpPkt.Data().AsRange().Checksum())) if err := route.WritePacket( diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index 63223bc92..25f5a52e3 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -1215,6 +1215,9 @@ type protocol struct { // eps is keyed by NICID to allow protocol methods to retrieve an endpoint // when handling a packet, by looking at which NIC handled the packet. eps map[tcpip.NICID]*endpoint + + // ICMP types for which the stack's global rate limiting must apply. + icmpRateLimitedTypes map[header.ICMPv4Type]struct{} } // defaultTTL is the current default TTL for the protocol. Only the @@ -1330,6 +1333,23 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu return ipHdr.TransportProtocol(), !ipHdr.More() && ipHdr.FragmentOffset() == 0, true } +// allowICMPReply reports whether an ICMP reply with provided type and code may +// be sent following the rate mask options and global ICMP rate limiter. +func (p *protocol) allowICMPReply(icmpType header.ICMPv4Type, code header.ICMPv4Code) bool { + // Mimic linux and never rate limit for PMTU discovery. + // https://github.com/torvalds/linux/blob/9e9fb7655ed585da8f468e29221f0ba194a5f613/net/ipv4/icmp.c#L288 + if icmpType == header.ICMPv4DstUnreachable && code == header.ICMPv4FragmentationNeeded { + return true + } + p.mu.RLock() + defer p.mu.RUnlock() + + if _, ok := p.mu.icmpRateLimitedTypes[icmpType]; ok { + return p.stack.AllowICMPMessage() + } + return true +} + // calculateNetworkMTU calculates the network-layer payload MTU based on the // link-layer payload mtu. func calculateNetworkMTU(linkMTU, networkHeaderSize uint32) (uint32, tcpip.Error) { @@ -1409,6 +1429,14 @@ func NewProtocolWithOptions(opts Options) stack.NetworkProtocolFactory { } p.fragmentation = fragmentation.NewFragmentation(fragmentblockSize, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, ReassembleTimeout, s.Clock(), p) p.mu.eps = make(map[tcpip.NICID]*endpoint) + // Set ICMP rate limiting to Linux defaults. + // See https://man7.org/linux/man-pages/man7/icmp.7.html. + p.mu.icmpRateLimitedTypes = map[header.ICMPv4Type]struct{}{ + header.ICMPv4DstUnreachable: struct{}{}, + header.ICMPv4SrcQuench: struct{}{}, + header.ICMPv4TimeExceeded: struct{}{}, + header.ICMPv4ParamProblem: struct{}{}, + } return p } } diff --git a/pkg/tcpip/network/ipv4/ipv4_test.go b/pkg/tcpip/network/ipv4/ipv4_test.go index e7b5b3ea2..ef91245d7 100644 --- a/pkg/tcpip/network/ipv4/ipv4_test.go +++ b/pkg/tcpip/network/ipv4/ipv4_test.go @@ -3373,3 +3373,139 @@ func TestCloseLocking(t *testing.T) { } }() } + +func TestIcmpRateLimit(t *testing.T) { + var ( + host1IPv4Addr = tcpip.ProtocolAddress{ + Protocol: ipv4.ProtocolNumber, + AddressWithPrefix: tcpip.AddressWithPrefix{ + Address: tcpip.Address(net.ParseIP("192.168.0.1").To4()), + PrefixLen: 24, + }, + } + host2IPv4Addr = tcpip.ProtocolAddress{ + Protocol: ipv4.ProtocolNumber, + AddressWithPrefix: tcpip.AddressWithPrefix{ + Address: tcpip.Address(net.ParseIP("192.168.0.2").To4()), + PrefixLen: 24, + }, + } + ) + const icmpBurst = 5 + e := channel.New(1, defaultMTU, tcpip.LinkAddress("")) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocolFactory{arp.NewProtocol, ipv4.NewProtocol}, + TransportProtocols: []stack.TransportProtocolFactory{udp.NewProtocol}, + Clock: faketime.NewManualClock(), + }) + s.SetICMPBurst(icmpBurst) + + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("s.CreateNIC(%d, _): %s", nicID, err) + } + if err := s.AddProtocolAddress(nicID, host1IPv4Addr, stack.AddressProperties{}); err != nil { + t.Fatalf("s.AddProtocolAddress(%d, %+v, {}): %s", nicID, host1IPv4Addr, err) + } + s.SetRouteTable([]tcpip.Route{ + { + Destination: host1IPv4Addr.AddressWithPrefix.Subnet(), + NIC: nicID, + }, + }) + tests := []struct { + name string + createPacket func() buffer.View + check func(*testing.T, *channel.Endpoint, int) + }{ + { + name: "echo", + createPacket: func() buffer.View { + totalLength := header.IPv4MinimumSize + header.ICMPv4MinimumSize + hdr := buffer.NewPrependable(totalLength) + icmpH := header.ICMPv4(hdr.Prepend(header.ICMPv4MinimumSize)) + icmpH.SetIdent(1) + icmpH.SetSequence(1) + icmpH.SetType(header.ICMPv4Echo) + icmpH.SetCode(header.ICMPv4UnusedCode) + icmpH.SetChecksum(0) + icmpH.SetChecksum(^header.Checksum(icmpH, 0)) + ip := header.IPv4(hdr.Prepend(header.IPv4MinimumSize)) + ip.Encode(&header.IPv4Fields{ + TotalLength: uint16(totalLength), + Protocol: uint8(header.ICMPv4ProtocolNumber), + TTL: 1, + SrcAddr: host2IPv4Addr.AddressWithPrefix.Address, + DstAddr: host1IPv4Addr.AddressWithPrefix.Address, + }) + ip.SetChecksum(^ip.CalculateChecksum()) + return hdr.View() + }, + check: func(t *testing.T, e *channel.Endpoint, round int) { + p, ok := e.Read() + if !ok { + t.Fatalf("expected echo response, no packet read in endpoint in round %d", round) + } + if got, want := p.Proto, header.IPv4ProtocolNumber; got != want { + t.Errorf("got p.Proto = %d, want = %d", got, want) + } + checker.IPv4(t, stack.PayloadSince(p.Pkt.NetworkHeader()), + checker.SrcAddr(host1IPv4Addr.AddressWithPrefix.Address), + checker.DstAddr(host2IPv4Addr.AddressWithPrefix.Address), + checker.ICMPv4( + checker.ICMPv4Type(header.ICMPv4EchoReply), + )) + }, + }, + { + name: "dst unreachable", + createPacket: func() buffer.View { + totalLength := header.IPv4MinimumSize + header.UDPMinimumSize + hdr := buffer.NewPrependable(totalLength) + udpH := header.UDP(hdr.Prepend(header.UDPMinimumSize)) + udpH.Encode(&header.UDPFields{ + SrcPort: 100, + DstPort: 101, + Length: header.UDPMinimumSize, + }) + ip := header.IPv4(hdr.Prepend(header.IPv4MinimumSize)) + ip.Encode(&header.IPv4Fields{ + TotalLength: uint16(totalLength), + Protocol: uint8(header.UDPProtocolNumber), + TTL: 1, + SrcAddr: host2IPv4Addr.AddressWithPrefix.Address, + DstAddr: host1IPv4Addr.AddressWithPrefix.Address, + }) + ip.SetChecksum(^ip.CalculateChecksum()) + return hdr.View() + }, + check: func(t *testing.T, e *channel.Endpoint, round int) { + p, ok := e.Read() + if round >= icmpBurst { + if ok { + t.Errorf("got packet %x in round %d, expected ICMP rate limit to stop it", p.Pkt.Data().Views(), round) + } + return + } + if !ok { + t.Fatalf("expected unreachable in round %d, no packet read in endpoint", round) + } + checker.IPv4(t, stack.PayloadSince(p.Pkt.NetworkHeader()), + checker.SrcAddr(host1IPv4Addr.AddressWithPrefix.Address), + checker.DstAddr(host2IPv4Addr.AddressWithPrefix.Address), + checker.ICMPv4( + checker.ICMPv4Type(header.ICMPv4DstUnreachable), + )) + }, + }, + } + for _, testCase := range tests { + t.Run(testCase.name, func(t *testing.T) { + for round := 0; round < icmpBurst+1; round++ { + e.InjectInbound(header.IPv4ProtocolNumber, stack.NewPacketBuffer(stack.PacketBufferOptions{ + Data: testCase.createPacket().ToVectorisedView(), + })) + testCase.check(t, e, round) + } + }) + } +} diff --git a/pkg/tcpip/network/ipv6/BUILD b/pkg/tcpip/network/ipv6/BUILD index f99cbf8f3..f814926a3 100644 --- a/pkg/tcpip/network/ipv6/BUILD +++ b/pkg/tcpip/network/ipv6/BUILD @@ -51,6 +51,7 @@ go_test( "//pkg/tcpip/transport/udp", "//pkg/waiter", "@com_github_google_go_cmp//cmp:go_default_library", + "@org_golang_x_time//rate:go_default_library", ], ) diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index 94caaae6c..6c6107264 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -692,6 +692,11 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer, hasFragmentHeader bool, r } defer r.Release() + if !e.protocol.allowICMPReply(header.ICMPv6EchoReply) { + sent.rateLimited.Increment() + return + } + replyPkt := stack.NewPacketBuffer(stack.PacketBufferOptions{ ReserveHeaderBytes: int(r.MaxHeaderLength()) + header.ICMPv6EchoMinimumSize, Data: pkt.Data().ExtractVV(), @@ -1174,13 +1179,6 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip return &tcpip.ErrNotConnected{} } - sent := netEP.stats.icmp.packetsSent - - if !p.stack.AllowICMPMessage() { - sent.rateLimited.Increment() - return nil - } - if pkt.TransportProtocolNumber == header.ICMPv6ProtocolNumber { // TODO(gvisor.dev/issues/3810): Sort this out when ICMP headers are stored. // Unfortunately at this time ICMP Packets do not have a transport @@ -1198,6 +1196,33 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip } } + sent := netEP.stats.icmp.packetsSent + icmpType, icmpCode, counter, typeSpecific := func() (header.ICMPv6Type, header.ICMPv6Code, tcpip.MultiCounterStat, uint32) { + switch reason := reason.(type) { + case *icmpReasonParameterProblem: + return header.ICMPv6ParamProblem, reason.code, sent.paramProblem, reason.pointer + case *icmpReasonPortUnreachable: + return header.ICMPv6DstUnreachable, header.ICMPv6PortUnreachable, sent.dstUnreachable, 0 + case *icmpReasonNetUnreachable: + return header.ICMPv6DstUnreachable, header.ICMPv6NetworkUnreachable, sent.dstUnreachable, 0 + case *icmpReasonHostUnreachable: + return header.ICMPv6DstUnreachable, header.ICMPv6AddressUnreachable, sent.dstUnreachable, 0 + case *icmpReasonPacketTooBig: + return header.ICMPv6PacketTooBig, header.ICMPv6UnusedCode, sent.packetTooBig, 0 + case *icmpReasonHopLimitExceeded: + return header.ICMPv6TimeExceeded, header.ICMPv6HopLimitExceeded, sent.timeExceeded, 0 + case *icmpReasonReassemblyTimeout: + return header.ICMPv6TimeExceeded, header.ICMPv6ReassemblyTimeout, sent.timeExceeded, 0 + default: + panic(fmt.Sprintf("unsupported ICMP type %T", reason)) + } + }() + + if !p.allowICMPReply(icmpType) { + sent.rateLimited.Increment() + return nil + } + network, transport := pkt.NetworkHeader().View(), pkt.TransportHeader().View() // As per RFC 4443 section 2.4 @@ -1232,40 +1257,10 @@ func (p *protocol) returnError(reason icmpReason, pkt *stack.PacketBuffer) tcpip newPkt.TransportProtocolNumber = header.ICMPv6ProtocolNumber icmpHdr := header.ICMPv6(newPkt.TransportHeader().Push(header.ICMPv6DstUnreachableMinimumSize)) - var counter tcpip.MultiCounterStat - switch reason := reason.(type) { - case *icmpReasonParameterProblem: - icmpHdr.SetType(header.ICMPv6ParamProblem) - icmpHdr.SetCode(reason.code) - icmpHdr.SetTypeSpecific(reason.pointer) - counter = sent.paramProblem - case *icmpReasonPortUnreachable: - icmpHdr.SetType(header.ICMPv6DstUnreachable) - icmpHdr.SetCode(header.ICMPv6PortUnreachable) - counter = sent.dstUnreachable - case *icmpReasonNetUnreachable: - icmpHdr.SetType(header.ICMPv6DstUnreachable) - icmpHdr.SetCode(header.ICMPv6NetworkUnreachable) - counter = sent.dstUnreachable - case *icmpReasonHostUnreachable: - icmpHdr.SetType(header.ICMPv6DstUnreachable) - icmpHdr.SetCode(header.ICMPv6AddressUnreachable) - counter = sent.dstUnreachable - case *icmpReasonPacketTooBig: - icmpHdr.SetType(header.ICMPv6PacketTooBig) - icmpHdr.SetCode(header.ICMPv6UnusedCode) - counter = sent.packetTooBig - case *icmpReasonHopLimitExceeded: - icmpHdr.SetType(header.ICMPv6TimeExceeded) - icmpHdr.SetCode(header.ICMPv6HopLimitExceeded) - counter = sent.timeExceeded - case *icmpReasonReassemblyTimeout: - icmpHdr.SetType(header.ICMPv6TimeExceeded) - icmpHdr.SetCode(header.ICMPv6ReassemblyTimeout) - counter = sent.timeExceeded - default: - panic(fmt.Sprintf("unsupported ICMP type %T", reason)) - } + icmpHdr.SetType(icmpType) + icmpHdr.SetCode(icmpCode) + icmpHdr.SetTypeSpecific(typeSpecific) + dataRange := newPkt.Data().AsRange() icmpHdr.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{ Header: icmpHdr, diff --git a/pkg/tcpip/network/ipv6/icmp_test.go b/pkg/tcpip/network/ipv6/icmp_test.go index 3b4c235fa..03d9f425c 100644 --- a/pkg/tcpip/network/ipv6/icmp_test.go +++ b/pkg/tcpip/network/ipv6/icmp_test.go @@ -22,6 +22,7 @@ import ( "testing" "github.com/google/go-cmp/cmp" + "golang.org/x/time/rate" "gvisor.dev/gvisor/pkg/tcpip" "gvisor.dev/gvisor/pkg/tcpip/buffer" "gvisor.dev/gvisor/pkg/tcpip/checker" @@ -1435,6 +1436,8 @@ func TestPacketQueing(t *testing.T) { TransportProtocols: []stack.TransportProtocolFactory{udp.NewProtocol}, Clock: clock, }) + // Make sure ICMP rate limiting doesn't get in our way. + s.SetICMPLimit(rate.Inf) if err := s.CreateNIC(nicID, e); err != nil { t.Fatalf("s.CreateNIC(%d, _): %s", nicID, err) diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index 3799d8245..dab99d00d 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -1990,6 +1990,9 @@ type protocol struct { // eps is keyed by NICID to allow protocol methods to retrieve an endpoint // when handling a packet, by looking at which NIC handled the packet. eps map[tcpip.NICID]*endpoint + + // ICMP types for which the stack's global rate limiting must apply. + icmpRateLimitedTypes map[header.ICMPv6Type]struct{} } ids []uint32 @@ -2001,7 +2004,8 @@ type protocol struct { // Must be accessed using atomic operations. defaultTTL uint32 - fragmentation *fragmentation.Fragmentation + fragmentation *fragmentation.Fragmentation + icmpRateLimiter *stack.ICMPRateLimiter } // Number returns the ipv6 protocol number. @@ -2177,6 +2181,18 @@ func (*protocol) Parse(pkt *stack.PacketBuffer) (proto tcpip.TransportProtocolNu return proto, !fragMore && fragOffset == 0, true } +// allowICMPReply reports whether an ICMP reply with provided type may +// be sent following the rate mask options and global ICMP rate limiter. +func (p *protocol) allowICMPReply(icmpType header.ICMPv6Type) bool { + p.mu.RLock() + defer p.mu.RUnlock() + + if _, ok := p.mu.icmpRateLimitedTypes[icmpType]; ok { + return p.stack.AllowICMPMessage() + } + return true +} + // calculateNetworkMTU calculates the network-layer payload MTU based on the // link-layer payload MTU and the length of every IPv6 header. // Note that this is different than the Payload Length field of the IPv6 header, @@ -2273,6 +2289,21 @@ func NewProtocolWithOptions(opts Options) stack.NetworkProtocolFactory { p.fragmentation = fragmentation.NewFragmentation(header.IPv6FragmentExtHdrFragmentOffsetBytesPerUnit, fragmentation.HighFragThreshold, fragmentation.LowFragThreshold, ReassembleTimeout, s.Clock(), p) p.mu.eps = make(map[tcpip.NICID]*endpoint) p.SetDefaultTTL(DefaultTTL) + // Set default ICMP rate limiting to Linux defaults. + // + // Default: 0-1,3-127 (rate limit ICMPv6 errors except Packet Too Big) + // See https://www.kernel.org/doc/Documentation/networking/ip-sysctl.txt. + defaultIcmpTypes := make(map[header.ICMPv6Type]struct{}) + for i := header.ICMPv6Type(0); i < header.ICMPv6EchoRequest; i++ { + switch i { + case header.ICMPv6PacketTooBig: + // Do not rate limit packet too big by default. + default: + defaultIcmpTypes[i] = struct{}{} + } + } + p.mu.icmpRateLimitedTypes = defaultIcmpTypes + return p } } diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go index 74f19900c..e5286081e 100644 --- a/pkg/tcpip/network/ipv6/ipv6_test.go +++ b/pkg/tcpip/network/ipv6/ipv6_test.go @@ -3522,3 +3522,149 @@ func TestMultiCounterStatsInitialization(t *testing.T) { t.Error(err) } } + +func TestIcmpRateLimit(t *testing.T) { + var ( + host1IPv6Addr = tcpip.ProtocolAddress{ + Protocol: ProtocolNumber, + AddressWithPrefix: tcpip.AddressWithPrefix{ + Address: tcpip.Address(net.ParseIP("10::1").To16()), + PrefixLen: 64, + }, + } + host2IPv6Addr = tcpip.ProtocolAddress{ + Protocol: ProtocolNumber, + AddressWithPrefix: tcpip.AddressWithPrefix{ + Address: tcpip.Address(net.ParseIP("10::2").To16()), + PrefixLen: 64, + }, + } + ) + const icmpBurst = 5 + e := channel.New(1, defaultMTU, tcpip.LinkAddress("")) + s := stack.New(stack.Options{ + NetworkProtocols: []stack.NetworkProtocolFactory{NewProtocol}, + TransportProtocols: []stack.TransportProtocolFactory{udp.NewProtocol}, + Clock: faketime.NewManualClock(), + }) + s.SetICMPBurst(icmpBurst) + + if err := s.CreateNIC(nicID, e); err != nil { + t.Fatalf("s.CreateNIC(%d, _): %s", nicID, err) + } + if err := s.AddProtocolAddress(nicID, host1IPv6Addr, stack.AddressProperties{}); err != nil { + t.Fatalf("s.AddProtocolAddress(%d, %+v, {}): %s", nicID, host1IPv6Addr, err) + } + s.SetRouteTable([]tcpip.Route{ + { + Destination: host1IPv6Addr.AddressWithPrefix.Subnet(), + NIC: nicID, + }, + }) + tests := []struct { + name string + createPacket func() buffer.View + check func(*testing.T, *channel.Endpoint, int) + }{ + { + name: "echo", + createPacket: func() buffer.View { + totalLength := header.IPv6MinimumSize + header.ICMPv6MinimumSize + hdr := buffer.NewPrependable(totalLength) + icmpH := header.ICMPv6(hdr.Prepend(header.ICMPv6MinimumSize)) + icmpH.SetIdent(1) + icmpH.SetSequence(1) + icmpH.SetType(header.ICMPv6EchoRequest) + icmpH.SetCode(header.ICMPv6UnusedCode) + icmpH.SetChecksum(0) + icmpH.SetChecksum(header.ICMPv6Checksum(header.ICMPv6ChecksumParams{ + Header: icmpH, + Src: host2IPv6Addr.AddressWithPrefix.Address, + Dst: host1IPv6Addr.AddressWithPrefix.Address, + })) + payloadLength := hdr.UsedLength() + ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize)) + ip.Encode(&header.IPv6Fields{ + PayloadLength: uint16(payloadLength), + TransportProtocol: header.ICMPv6ProtocolNumber, + HopLimit: 1, + SrcAddr: host2IPv6Addr.AddressWithPrefix.Address, + DstAddr: host1IPv6Addr.AddressWithPrefix.Address, + }) + return hdr.View() + }, + check: func(t *testing.T, e *channel.Endpoint, round int) { + p, ok := e.Read() + if !ok { + t.Fatalf("expected echo response, no packet read in endpoint in round %d", round) + } + if got, want := p.Proto, header.IPv6ProtocolNumber; got != want { + t.Errorf("got p.Proto = %d, want = %d", got, want) + } + checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()), + checker.SrcAddr(host1IPv6Addr.AddressWithPrefix.Address), + checker.DstAddr(host2IPv6Addr.AddressWithPrefix.Address), + checker.ICMPv6( + checker.ICMPv6Type(header.ICMPv6EchoReply), + )) + }, + }, + { + name: "dst unreachable", + createPacket: func() buffer.View { + totalLength := header.IPv6MinimumSize + header.UDPMinimumSize + hdr := buffer.NewPrependable(totalLength) + udpH := header.UDP(hdr.Prepend(header.UDPMinimumSize)) + udpH.Encode(&header.UDPFields{ + SrcPort: 100, + DstPort: 101, + Length: header.UDPMinimumSize, + }) + + // Calculate the UDP checksum and set it. + sum := header.PseudoHeaderChecksum(udp.ProtocolNumber, host2IPv6Addr.AddressWithPrefix.Address, host1IPv6Addr.AddressWithPrefix.Address, header.UDPMinimumSize) + sum = header.Checksum(nil, sum) + udpH.SetChecksum(^udpH.CalculateChecksum(sum)) + + payloadLength := hdr.UsedLength() + ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize)) + ip.Encode(&header.IPv6Fields{ + PayloadLength: uint16(payloadLength), + TransportProtocol: header.UDPProtocolNumber, + HopLimit: 1, + SrcAddr: host2IPv6Addr.AddressWithPrefix.Address, + DstAddr: host1IPv6Addr.AddressWithPrefix.Address, + }) + return hdr.View() + }, + check: func(t *testing.T, e *channel.Endpoint, round int) { + p, ok := e.Read() + if round >= icmpBurst { + if ok { + t.Errorf("got packet %x in round %d, expected ICMP rate limit to stop it", p.Pkt.Data().Views(), round) + } + return + } + if !ok { + t.Fatalf("expected unreachable in round %d, no packet read in endpoint", round) + } + checker.IPv6(t, stack.PayloadSince(p.Pkt.NetworkHeader()), + checker.SrcAddr(host1IPv6Addr.AddressWithPrefix.Address), + checker.DstAddr(host2IPv6Addr.AddressWithPrefix.Address), + checker.ICMPv6( + checker.ICMPv6Type(header.ICMPv6DstUnreachable), + )) + }, + }, + } + for _, testCase := range tests { + t.Run(testCase.name, func(t *testing.T) { + for round := 0; round < icmpBurst+1; round++ { + e.InjectInbound(header.IPv6ProtocolNumber, stack.NewPacketBuffer(stack.PacketBufferOptions{ + Data: testCase.createPacket().ToVectorisedView(), + })) + testCase.check(t, e, round) + } + }) + } +} |