diff options
Diffstat (limited to 'pkg/tcpip')
-rw-r--r-- | pkg/tcpip/checker/checker.go | 11 | ||||
-rw-r--r-- | pkg/tcpip/network/internal/ip/errors.go | 10 | ||||
-rw-r--r-- | pkg/tcpip/network/internal/ip/stats.go | 30 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv4/ipv4.go | 4 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/icmp.go | 8 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 113 | ||||
-rw-r--r-- | pkg/tcpip/network/ipv6/ipv6_test.go | 176 | ||||
-rw-r--r-- | pkg/tcpip/tcpip.go | 12 |
8 files changed, 308 insertions, 56 deletions
diff --git a/pkg/tcpip/checker/checker.go b/pkg/tcpip/checker/checker.go index 12c39dfa3..18e6cc3cd 100644 --- a/pkg/tcpip/checker/checker.go +++ b/pkg/tcpip/checker/checker.go @@ -1607,6 +1607,17 @@ func IPv6RouterAlert(want header.IPv6RouterAlertValue) IPv6ExtHdrOptionChecker { } } +// IPv6UnknownOption validates that an extension header option is the +// unknown header option. +func IPv6UnknownOption() IPv6ExtHdrOptionChecker { + return func(t *testing.T, opt header.IPv6ExtHdrOption) { + _, ok := opt.(*header.IPv6UnknownExtHdrOption) + if !ok { + t.Errorf("got = %T, want = header.IPv6UnknownExtHdrOption", opt) + } + } +} + // IgnoreCmpPath returns a cmp.Option that ignores listed field paths. func IgnoreCmpPath(paths ...string) cmp.Option { ignores := map[string]struct{}{} diff --git a/pkg/tcpip/network/internal/ip/errors.go b/pkg/tcpip/network/internal/ip/errors.go index 50fabfd79..d3577b377 100644 --- a/pkg/tcpip/network/internal/ip/errors.go +++ b/pkg/tcpip/network/internal/ip/errors.go @@ -34,13 +34,13 @@ func (*ErrTTLExceeded) isForwardingError() {} func (*ErrTTLExceeded) String() string { return "ttl exceeded" } -// ErrIPOptProblem indicates the received packet had a problem with an IP -// option. -type ErrIPOptProblem struct{} +// ErrParameterProblem indicates the received packet had a problem with an IP +// parameter. +type ErrParameterProblem struct{} -func (*ErrIPOptProblem) isForwardingError() {} +func (*ErrParameterProblem) isForwardingError() {} -func (*ErrIPOptProblem) String() string { return "ip option problem" } +func (*ErrParameterProblem) String() string { return "parameter problem" } // ErrLinkLocalSourceAddress indicates the received packet had a link-local // source address. diff --git a/pkg/tcpip/network/internal/ip/stats.go b/pkg/tcpip/network/internal/ip/stats.go index 392f0b0c7..68b8b550e 100644 --- a/pkg/tcpip/network/internal/ip/stats.go +++ b/pkg/tcpip/network/internal/ip/stats.go @@ -16,7 +16,7 @@ package ip import "gvisor.dev/gvisor/pkg/tcpip" -// LINT.IfChange(MultiCounterIPStats) +// LINT.IfChange(MultiCounterIPForwardingStats) // MultiCounterIPForwardingStats holds IP forwarding statistics. Each counter // may have several versions. @@ -38,11 +38,30 @@ type MultiCounterIPForwardingStats struct { // because they contained a link-local destination address. LinkLocalDestination tcpip.MultiCounterStat + // ExtensionHeaderProblem is the number of IP packets which were dropped + // because of a problem encountered when processing an IPv6 extension + // header. + ExtensionHeaderProblem tcpip.MultiCounterStat + // Errors is the number of IP packets received which could not be // successfully forwarded. Errors tcpip.MultiCounterStat } +// Init sets internal counters to track a and b counters. +func (m *MultiCounterIPForwardingStats) Init(a, b *tcpip.IPForwardingStats) { + m.Unrouteable.Init(a.Unrouteable, b.Unrouteable) + m.Errors.Init(a.Errors, b.Errors) + m.LinkLocalSource.Init(a.LinkLocalSource, b.LinkLocalSource) + m.LinkLocalDestination.Init(a.LinkLocalDestination, b.LinkLocalDestination) + m.ExtensionHeaderProblem.Init(a.ExtensionHeaderProblem, b.ExtensionHeaderProblem) + m.ExhaustedTTL.Init(a.ExhaustedTTL, b.ExhaustedTTL) +} + +// LINT.ThenChange(:MultiCounterIPForwardingStats, ../../../tcpip.go:IPForwardingStats) + +// LINT.IfChange(MultiCounterIPStats) + // MultiCounterIPStats holds IP statistics, each counter may have several // versions. type MultiCounterIPStats struct { @@ -120,15 +139,6 @@ type MultiCounterIPStats struct { } // Init sets internal counters to track a and b counters. -func (m *MultiCounterIPForwardingStats) Init(a, b *tcpip.IPForwardingStats) { - m.Unrouteable.Init(a.Unrouteable, b.Unrouteable) - m.Errors.Init(a.Errors, b.Errors) - m.LinkLocalSource.Init(a.LinkLocalSource, b.LinkLocalSource) - m.LinkLocalDestination.Init(a.LinkLocalDestination, b.LinkLocalDestination) - m.ExhaustedTTL.Init(a.ExhaustedTTL, b.ExhaustedTTL) -} - -// Init sets internal counters to track a and b counters. func (m *MultiCounterIPStats) Init(a, b *tcpip.IPStats) { m.PacketsReceived.Init(a.PacketsReceived, b.PacketsReceived) m.DisabledPacketsReceived.Init(a.DisabledPacketsReceived, b.DisabledPacketsReceived) diff --git a/pkg/tcpip/network/ipv4/ipv4.go b/pkg/tcpip/network/ipv4/ipv4.go index b11e56c6a..19657fde1 100644 --- a/pkg/tcpip/network/ipv4/ipv4.go +++ b/pkg/tcpip/network/ipv4/ipv4.go @@ -645,7 +645,7 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) ip.ForwardingError { forwarding: true, }, pkt) } - return &ip.ErrIPOptProblem{} + return &ip.ErrParameterProblem{} } copied := copy(opts, newOpts) if copied != len(newOpts) { @@ -827,7 +827,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv4, pkt *stack.PacketBuffer) stats.ip.Forwarding.ExhaustedTTL.Increment() case *ip.ErrNoRoute: stats.ip.Forwarding.Unrouteable.Increment() - case *ip.ErrIPOptProblem: + case *ip.ErrParameterProblem: e.protocol.stack.Stats().MalformedRcvdPackets.Increment() stats.ip.MalformedPacketsReceived.Increment() default: diff --git a/pkg/tcpip/network/ipv6/icmp.go b/pkg/tcpip/network/ipv6/icmp.go index ebb0b73df..247a07dc2 100644 --- a/pkg/tcpip/network/ipv6/icmp.go +++ b/pkg/tcpip/network/ipv6/icmp.go @@ -984,11 +984,15 @@ type icmpReasonParameterProblem struct { // packet if the field in error is beyond what can fit // in the maximum size of an ICMPv6 error message. pointer uint32 + + // forwarding indicates that the problem arose while we were trying to forward + // a packet. + forwarding bool } func (*icmpReasonParameterProblem) isICMPReason() {} -func (*icmpReasonParameterProblem) isForwarding() bool { - return false +func (p *icmpReasonParameterProblem) isForwarding() bool { + return p.forwarding } // icmpReasonPortUnreachable is an error where the transport protocol has no diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index 659057fa7..4fdb2793d 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -941,6 +941,11 @@ func (e *endpoint) forwardPacket(pkt *stack.PacketBuffer) ip.ForwardingError { return nil } + // Check extension headers for any errors requiring action during forwarding. + if err := e.processExtensionHeaders(h, pkt, true /* forwarding */); err != nil { + return &ip.ErrParameterProblem{} + } + r, err := e.protocol.stack.FindRoute(0, "", dstAddr, ProtocolNumber, false /* multicastLoop */) switch err.(type) { case nil: @@ -1084,6 +1089,8 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) e.stats.ip.Forwarding.ExhaustedTTL.Increment() case *ip.ErrNoRoute: e.stats.ip.Forwarding.Unrouteable.Increment() + case *ip.ErrParameterProblem: + e.stats.ip.Forwarding.ExtensionHeaderProblem.Increment() default: panic(fmt.Sprintf("unexpected error %s while trying to forward packet: %#v", err, pkt)) } @@ -1091,6 +1098,28 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) return } + // iptables filtering. All packets that reach here are intended for + // this machine and need not be forwarded. + inNicName := e.protocol.stack.FindNICNameFromID(e.nic.ID()) + if ok := e.protocol.stack.IPTables().Check(stack.Input, pkt, nil, "" /* preroutingAddr */, inNicName, "" /* outNicName */); !ok { + // iptables is telling us to drop the packet. + stats.IPTablesInputDropped.Increment() + return + } + + // Any returned error is only useful for terminating execution early, but + // we have nothing left to do, so we can drop it. + _ = e.processExtensionHeaders(h, pkt, false /* forwarding */) +} + +// processExtensionHeaders processes the extension headers in the given packet. +// Returns an error if the processing of a header failed or if the packet should +// be discarded. +func (e *endpoint) processExtensionHeaders(h header.IPv6, pkt *stack.PacketBuffer, forwarding bool) error { + stats := e.stats.ip + srcAddr := h.SourceAddress() + dstAddr := h.DestinationAddress() + // Create a VV to parse the packet. We don't plan to modify anything here. // vv consists of: // - Any IPv6 header bytes after the first 40 (i.e. extensions). @@ -1101,15 +1130,6 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) vv.AppendViews(pkt.Data().Views()) it := header.MakeIPv6PayloadIterator(header.IPv6ExtensionHeaderIdentifier(h.NextHeader()), vv) - // iptables filtering. All packets that reach here are intended for - // this machine and need not be forwarded. - inNicName := e.protocol.stack.FindNICNameFromID(e.nic.ID()) - if ok := e.protocol.stack.IPTables().Check(stack.Input, pkt, nil, "" /* preroutingAddr */, inNicName, "" /* outNicName */); !ok { - // iptables is telling us to drop the packet. - stats.IPTablesInputDropped.Increment() - return - } - var ( hasFragmentHeader bool routerAlert *header.IPv6RouterAlertOption @@ -1122,22 +1142,41 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) extHdr, done, err := it.Next() if err != nil { stats.MalformedPacketsReceived.Increment() - return + return err } if done { break } + // As per RFC 8200, section 4: + // + // Extension headers (except for the Hop-by-Hop Options header) are + // not processed, inserted, or deleted by any node along a packet's + // delivery path until the packet reaches the node identified in the + // Destination Address field of the IPv6 header. + // + // Furthermore, as per RFC 8200 section 4.1, the Hop By Hop extension + // header is restricted to appear first in the list of extension headers. + // + // Therefore, we can immediately return once we hit any header other + // than the Hop-by-Hop header while forwarding a packet. + if forwarding { + if _, ok := extHdr.(header.IPv6HopByHopOptionsExtHdr); !ok { + return nil + } + } + switch extHdr := extHdr.(type) { case header.IPv6HopByHopOptionsExtHdr: // As per RFC 8200 section 4.1, the Hop By Hop extension header is // restricted to appear immediately after an IPv6 fixed header. if previousHeaderStart != 0 { _ = e.protocol.returnError(&icmpReasonParameterProblem{ - code: header.ICMPv6UnknownHeader, - pointer: previousHeaderStart, + code: header.ICMPv6UnknownHeader, + pointer: previousHeaderStart, + forwarding: forwarding, }, pkt) - return + return fmt.Errorf("found Hop-by-Hop header = %#v with non-zero previous header offset = %d", extHdr, previousHeaderStart) } optsIt := extHdr.Iter() @@ -1146,7 +1185,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) opt, done, err := optsIt.Next() if err != nil { stats.MalformedPacketsReceived.Increment() - return + return err } if done { break @@ -1161,7 +1200,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) // There MUST only be one option of this type, regardless of // value, per Hop-by-Hop header. stats.MalformedPacketsReceived.Increment() - return + return fmt.Errorf("found multiple Router Alert options (%#v, %#v)", opt, routerAlert) } routerAlert = opt stats.OptionRouterAlertReceived.Increment() @@ -1169,10 +1208,10 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) switch opt.UnknownAction() { case header.IPv6OptionUnknownActionSkip: case header.IPv6OptionUnknownActionDiscard: - return + return fmt.Errorf("found unknown Hop-by-Hop header option = %#v with discard action", opt) case header.IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest: if header.IsV6MulticastAddress(dstAddr) { - return + return fmt.Errorf("found unknown hop-by-hop header option = %#v with discard action", opt) } fallthrough case header.IPv6OptionUnknownActionDiscardSendICMP: @@ -1187,10 +1226,11 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) code: header.ICMPv6UnknownOption, pointer: it.ParseOffset() + optsIt.OptionOffset(), respondToMulticast: true, + forwarding: forwarding, }, pkt) - return + return fmt.Errorf("found unknown hop-by-hop header option = %#v with discard action", opt) default: - panic(fmt.Sprintf("unrecognized action for an unrecognized Hop By Hop extension header option = %d", opt)) + panic(fmt.Sprintf("unrecognized action for an unrecognized Hop By Hop extension header option = %#v", opt)) } } } @@ -1212,8 +1252,13 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) _ = e.protocol.returnError(&icmpReasonParameterProblem{ code: header.ICMPv6ErroneousHeader, pointer: it.ParseOffset(), + // For the sake of consistency, we're using the value of `forwarding` + // here, even though it should always be false if we've reached this + // point. If `forwarding` is true here, we're executing undefined + // behavior no matter what. + forwarding: forwarding, }, pkt) - return + return fmt.Errorf("found unrecognized routing type with non-zero segments left in header = %#v", extHdr) } case header.IPv6FragmentExtHdr: @@ -1248,7 +1293,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) if err != nil { stats.MalformedPacketsReceived.Increment() stats.MalformedFragmentsReceived.Increment() - return + return err } if done { break @@ -1276,7 +1321,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) default: stats.MalformedPacketsReceived.Increment() stats.MalformedFragmentsReceived.Increment() - return + return fmt.Errorf("known extension header = %#v present after fragment header in a non-initial fragment", lastHdr) } } @@ -1285,7 +1330,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) // Drop the packet as it's marked as a fragment but has no payload. stats.MalformedPacketsReceived.Increment() stats.MalformedFragmentsReceived.Increment() - return + return fmt.Errorf("fragment has no payload") } // As per RFC 2460 Section 4.5: @@ -1303,7 +1348,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) code: header.ICMPv6ErroneousHeader, pointer: header.IPv6PayloadLenOffset, }, pkt) - return + return fmt.Errorf("found fragment length = %d that is not a multiple of 8 octets", fragmentPayloadLen) } // The packet is a fragment, let's try to reassemble it. @@ -1317,14 +1362,15 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) // Parameter Problem, Code 0, message should be sent to the source of // the fragment, pointing to the Fragment Offset field of the fragment // packet. - if int(start)+fragmentPayloadLen > header.IPv6MaximumPayloadSize { + lengthAfterReassembly := int(start) + fragmentPayloadLen + if lengthAfterReassembly > header.IPv6MaximumPayloadSize { stats.MalformedPacketsReceived.Increment() stats.MalformedFragmentsReceived.Increment() _ = e.protocol.returnError(&icmpReasonParameterProblem{ code: header.ICMPv6ErroneousHeader, pointer: fragmentFieldOffset, }, pkt) - return + return fmt.Errorf("determined that reassembled packet length = %d would exceed allowed length = %d", lengthAfterReassembly, header.IPv6MaximumPayloadSize) } // Note that pkt doesn't have its transport header set after reassembly, @@ -1346,7 +1392,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) if err != nil { stats.MalformedPacketsReceived.Increment() stats.MalformedFragmentsReceived.Increment() - return + return err } if ready { @@ -1368,7 +1414,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) opt, done, err := optsIt.Next() if err != nil { stats.MalformedPacketsReceived.Increment() - return + return err } if done { break @@ -1379,10 +1425,10 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) switch opt.UnknownAction() { case header.IPv6OptionUnknownActionSkip: case header.IPv6OptionUnknownActionDiscard: - return + return fmt.Errorf("found unknown destination header option = %#v with discard action", opt) case header.IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest: if header.IsV6MulticastAddress(dstAddr) { - return + return fmt.Errorf("found unknown destination header option %#v with discard action", opt) } fallthrough case header.IPv6OptionUnknownActionDiscardSendICMP: @@ -1399,9 +1445,9 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) pointer: it.ParseOffset() + optsIt.OptionOffset(), respondToMulticast: true, }, pkt) - return + return fmt.Errorf("found unknown destination header option %#v with discard action", opt) default: - panic(fmt.Sprintf("unrecognized action for an unrecognized Destination extension header option = %d", opt)) + panic(fmt.Sprintf("unrecognized action for an unrecognized Destination extension header option = %#v", opt)) } } @@ -1432,6 +1478,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) // transport protocol (e.g., UDP) has no listener, if that transport // protocol has no alternative means to inform the sender. _ = e.protocol.returnError(&icmpReasonPortUnreachable{}, pkt) + return fmt.Errorf("destination port unreachable") case stack.TransportPacketProtocolUnreachable: // As per RFC 8200 section 4. (page 7): // Extension headers are numbered from IANA IP Protocol Numbers @@ -1463,6 +1510,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) code: header.ICMPv6UnknownHeader, pointer: prevHdrIDOffset, }, pkt) + return fmt.Errorf("transport protocol unreachable") default: panic(fmt.Sprintf("unrecognized result from DeliverTransportPacket = %d", res)) } @@ -1476,6 +1524,7 @@ func (e *endpoint) handleValidatedPacket(h header.IPv6, pkt *stack.PacketBuffer) } } + return nil } // Close cleans up resources associated with the endpoint. diff --git a/pkg/tcpip/network/ipv6/ipv6_test.go b/pkg/tcpip/network/ipv6/ipv6_test.go index 4fbe39528..5307516d7 100644 --- a/pkg/tcpip/network/ipv6/ipv6_test.go +++ b/pkg/tcpip/network/ipv6/ipv6_test.go @@ -3025,6 +3025,7 @@ func TestForwarding(t *testing.T) { tests := []struct { name string + extHdr func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) TTL uint8 expectErrorICMP bool expectPacketForwarded bool @@ -3036,6 +3037,7 @@ func TestForwarding(t *testing.T) { expectPacketUnrouteableError bool expectLinkLocalSourceError bool expectLinkLocalDestError bool + expectExtensionHeaderError bool }{ { name: "TTL of zero", @@ -3108,6 +3110,158 @@ func TestForwarding(t *testing.T) { destAddr: remoteIPv6Addr2, expectLinkLocalSourceError: true, }, + { + name: "Hopbyhop with unknown option skippable action", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: remoteIPv6Addr2, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Skippable unknown. + 63, 4, 1, 2, 3, 4, + + // Skippable unknown. + 62, 6, 1, 2, 3, 4, 5, 6, + }, hopByHopExtHdrID, checker.IPv6ExtHdr(checker.IPv6HopByHopExtensionHeader(checker.IPv6UnknownOption(), checker.IPv6UnknownOption())) + }, + expectPacketForwarded: true, + }, + { + name: "Hopbyhop with unknown option discard action", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: remoteIPv6Addr2, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Skippable unknown. + 63, 4, 1, 2, 3, 4, + + // Discard unknown. + 127, 6, 1, 2, 3, 4, 5, 6, + }, hopByHopExtHdrID, nil + }, + expectExtensionHeaderError: true, + }, + { + name: "Hopbyhop with unknown option discard and send icmp action (unicast)", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: remoteIPv6Addr2, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Skippable unknown. + 63, 4, 1, 2, 3, 4, + + // Discard & send ICMP if option is unknown. + 191, 6, 1, 2, 3, 4, 5, 6, + }, hopByHopExtHdrID, nil + }, + expectErrorICMP: true, + icmpType: header.ICMPv6ParamProblem, + icmpCode: header.ICMPv6UnknownOption, + expectExtensionHeaderError: true, + }, + { + name: "Hopbyhop with unknown option discard and send icmp action (multicast)", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: multicastIPv6Addr, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Skippable unknown. + 63, 4, 1, 2, 3, 4, + + // Discard & send ICMP if option is unknown. + 191, 6, 1, 2, 3, 4, 5, 6, + }, hopByHopExtHdrID, nil + }, + expectErrorICMP: true, + icmpType: header.ICMPv6ParamProblem, + icmpCode: header.ICMPv6UnknownOption, + expectExtensionHeaderError: true, + }, + { + name: "Hopbyhop with unknown option discard and send icmp action unless multicast dest (unicast)", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: remoteIPv6Addr2, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Skippable unknown. + 63, 4, 1, 2, 3, 4, + + // Discard & send ICMP unless packet is for multicast destination if + // option is unknown. + 255, 6, 1, 2, 3, 4, 5, 6, + }, hopByHopExtHdrID, nil + }, + expectErrorICMP: true, + icmpType: header.ICMPv6ParamProblem, + icmpCode: header.ICMPv6UnknownOption, + expectExtensionHeaderError: true, + }, + { + name: "Hopbyhop with unknown option discard and send icmp action unless multicast dest (multicast)", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: multicastIPv6Addr, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Skippable unknown. + 63, 4, 1, 2, 3, 4, + + // Discard & send ICMP unless packet is for multicast destination if + // option is unknown. + 255, 6, 1, 2, 3, 4, 5, 6, + }, hopByHopExtHdrID, nil + }, + expectExtensionHeaderError: true, + }, + { + name: "Hopbyhop with router alert option", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: remoteIPv6Addr2, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 0, + + // Router Alert option. + 5, 2, 0, 0, 0, 0, + }, hopByHopExtHdrID, checker.IPv6ExtHdr(checker.IPv6HopByHopExtensionHeader(checker.IPv6RouterAlert(header.IPv6RouterAlertMLD))) + }, + expectPacketForwarded: true, + }, + { + name: "Hopbyhop with two router alert options", + TTL: 2, + sourceAddr: remoteIPv6Addr1, + destAddr: remoteIPv6Addr2, + extHdr: func(nextHdr uint8) ([]byte, uint8, checker.NetworkChecker) { + return []byte{ + nextHdr, 1, + + // Router Alert option. + 5, 2, 0, 0, 0, 0, + + // Router Alert option. + 5, 2, 0, 0, 0, 0, + }, hopByHopExtHdrID, nil + }, + expectExtensionHeaderError: true, + }, } for _, test := range tests { @@ -3150,7 +3304,17 @@ func TestForwarding(t *testing.T) { t.Fatalf("SetForwarding(%d, true): %s", ProtocolNumber, err) } - hdr := buffer.NewPrependable(header.IPv6MinimumSize + header.ICMPv6MinimumSize) + transportProtocol := header.ICMPv6ProtocolNumber + extHdrBytes := []byte{} + extHdrChecker := checker.IPv6ExtHdr() + if test.extHdr != nil { + nextHdrID := hopByHopExtHdrID + extHdrBytes, nextHdrID, extHdrChecker = test.extHdr(uint8(header.ICMPv6ProtocolNumber)) + transportProtocol = tcpip.TransportProtocolNumber(nextHdrID) + } + extHdrLen := len(extHdrBytes) + + hdr := buffer.NewPrependable(header.IPv6MinimumSize + header.ICMPv6MinimumSize + extHdrLen) icmp := header.ICMPv6(hdr.Prepend(header.ICMPv6MinimumSize)) icmp.SetIdent(randomIdent) icmp.SetSequence(randomSequence) @@ -3162,10 +3326,11 @@ func TestForwarding(t *testing.T) { Src: test.sourceAddr, Dst: test.destAddr, })) + copy(hdr.Prepend(extHdrLen), extHdrBytes) ip := header.IPv6(hdr.Prepend(header.IPv6MinimumSize)) ip.Encode(&header.IPv6Fields{ PayloadLength: header.ICMPv6MinimumSize, - TransportProtocol: header.ICMPv6ProtocolNumber, + TransportProtocol: transportProtocol, HopLimit: test.TTL, SrcAddr: test.sourceAddr, DstAddr: test.destAddr, @@ -3205,10 +3370,11 @@ func TestForwarding(t *testing.T) { t.Fatal("expected ICMP Echo Request packet through outgoing NIC") } - checker.IPv6(t, header.IPv6(stack.PayloadSince(reply.Pkt.NetworkHeader())), + checker.IPv6WithExtHdr(t, header.IPv6(stack.PayloadSince(reply.Pkt.NetworkHeader())), checker.SrcAddr(test.sourceAddr), checker.DstAddr(test.destAddr), checker.TTL(test.TTL-1), + extHdrChecker, checker.ICMPv6( checker.ICMPv6Type(header.ICMPv6EchoRequest), checker.ICMPv6Code(header.ICMPv6UnusedCode), @@ -3249,6 +3415,10 @@ func TestForwarding(t *testing.T) { if got, want := s.Stats().IP.Forwarding.Errors.Value(), boolToInt(!test.expectPacketForwarded); got != want { t.Errorf("got s.Stats().IP.Forwarding.Errors.Value() = %d, want = %d", got, want) } + + if got, want := s.Stats().IP.Forwarding.ExtensionHeaderProblem.Value(), boolToInt(test.expectExtensionHeaderError); got != want { + t.Errorf("got s.Stats().IP.Forwarding.ExtensionHeaderProblem.Value() = %d, want = %d", got, want) + } }) } } diff --git a/pkg/tcpip/tcpip.go b/pkg/tcpip/tcpip.go index d5f941c5f..6d7e22afe 100644 --- a/pkg/tcpip/tcpip.go +++ b/pkg/tcpip/tcpip.go @@ -1530,9 +1530,10 @@ type IGMPStats struct { // IPForwardingStats collects stats related to IP forwarding (both v4 and v6). type IPForwardingStats struct { + // LINT.IfChange(IPForwardingStats) + // Unrouteable is the number of IP packets received which were dropped - // because the netstack could not construct a route to their - // destination. + // because a route to their destination could not be constructed. Unrouteable *StatCounter // ExhaustedTTL is the number of IP packets received which were dropped @@ -1547,9 +1548,16 @@ type IPForwardingStats struct { // because they contained a link-local destination address. LinkLocalDestination *StatCounter + // ExtensionHeaderProblem is the number of IP packets which were dropped + // because of a problem encountered when processing an IPv6 extension + // header. + ExtensionHeaderProblem *StatCounter + // Errors is the number of IP packets received which could not be // successfully forwarded. Errors *StatCounter + + // LINT.ThenChange(network/internal/ip/stats.go:multiCounterIPForwardingStats) } // IPStats collects IP-specific stats (both v4 and v6). |