diff options
Diffstat (limited to 'pkg/tcpip/network/ipv6/ipv6.go')
| -rw-r--r-- | pkg/tcpip/network/ipv6/ipv6.go | 115 |
1 files changed, 84 insertions, 31 deletions
diff --git a/pkg/tcpip/network/ipv6/ipv6.go b/pkg/tcpip/network/ipv6/ipv6.go index aff4e1425..7458c3795 100644 --- a/pkg/tcpip/network/ipv6/ipv6.go +++ b/pkg/tcpip/network/ipv6/ipv6.go @@ -1,4 +1,4 @@ -// Copyright 2018 The gVisor Authors. +// 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. @@ -536,7 +536,10 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { return } - for firstHeader := true; ; firstHeader = false { + for { + // Keep track of the start of the previous header so we can report the + // special case of a Hop by Hop at a location other than at the start. + previousHeaderStart := it.HeaderOffset() extHdr, done, err := it.Next() if err != nil { r.Stats().IP.MalformedPacketsReceived.Increment() @@ -550,11 +553,11 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { 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. - // - // TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1 - // (unrecognized next header) error in response to an extension header's - // Next Header field with the Hop By Hop extension header identifier. - if !firstHeader { + if previousHeaderStart != 0 { + _ = returnError(r, &icmpReasonParameterProblem{ + code: header.ICMPv6UnknownHeader, + pointer: previousHeaderStart, + }, pkt) return } @@ -576,13 +579,25 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { case header.IPv6OptionUnknownActionSkip: case header.IPv6OptionUnknownActionDiscard: return - case header.IPv6OptionUnknownActionDiscardSendICMP: - // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for - // unrecognized IPv6 extension header options. - return case header.IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest: - // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for - // unrecognized IPv6 extension header options. + if header.IsV6MulticastAddress(r.LocalAddress) { + return + } + fallthrough + case header.IPv6OptionUnknownActionDiscardSendICMP: + // This case satisfies a requirement of RFC 8200 section 4.2 + // which states that an unknown option starting with bits [10] should: + // + // discard the packet and, regardless of whether or not the + // packet's Destination Address was a multicast address, send an + // ICMP Parameter Problem, Code 2, message to the packet's + // Source Address, pointing to the unrecognized Option Type. + // + _ = returnError(r, &icmpReasonParameterProblem{ + code: header.ICMPv6UnknownOption, + pointer: it.ParseOffset() + optsIt.OptionOffset(), + respondToMulticast: true, + }, pkt) return default: panic(fmt.Sprintf("unrecognized action for an unrecognized Hop By Hop extension header option = %d", opt)) @@ -593,16 +608,20 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { // As per RFC 8200 section 4.4, if a node encounters a routing header with // an unrecognized routing type value, with a non-zero Segments Left // value, the node must discard the packet and send an ICMP Parameter - // Problem, Code 0. If the Segments Left is 0, the node must ignore the - // Routing extension header and process the next header in the packet. + // Problem, Code 0 to the packet's Source Address, pointing to the + // unrecognized Routing Type. + // + // If the Segments Left is 0, the node must ignore the Routing extension + // header and process the next header in the packet. // // Note, the stack does not yet handle any type of routing extension // header, so we just make sure Segments Left is zero before processing // the next extension header. - // - // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 0 for - // unrecognized routing types with a non-zero Segments Left value. if extHdr.SegmentsLeft() != 0 { + _ = returnError(r, &icmpReasonParameterProblem{ + code: header.ICMPv6ErroneousHeader, + pointer: it.ParseOffset(), + }, pkt) return } @@ -737,13 +756,25 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { case header.IPv6OptionUnknownActionSkip: case header.IPv6OptionUnknownActionDiscard: return - case header.IPv6OptionUnknownActionDiscardSendICMP: - // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for - // unrecognized IPv6 extension header options. - return case header.IPv6OptionUnknownActionDiscardSendICMPNoMulticastDest: - // TODO(b/152019344): Send an ICMPv6 Parameter Problem Code 2 for - // unrecognized IPv6 extension header options. + if header.IsV6MulticastAddress(r.LocalAddress) { + return + } + fallthrough + case header.IPv6OptionUnknownActionDiscardSendICMP: + // This case satisfies a requirement of RFC 8200 section 4.2 + // which states that an unknown option starting with bits [10] should: + // + // discard the packet and, regardless of whether or not the + // packet's Destination Address was a multicast address, send an + // ICMP Parameter Problem, Code 2, message to the packet's + // Source Address, pointing to the unrecognized Option Type. + // + _ = returnError(r, &icmpReasonParameterProblem{ + code: header.ICMPv6UnknownOption, + pointer: it.ParseOffset() + optsIt.OptionOffset(), + respondToMulticast: true, + }, pkt) return default: panic(fmt.Sprintf("unrecognized action for an unrecognized Destination extension header option = %d", opt)) @@ -767,8 +798,7 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { pkt.TransportProtocolNumber = p e.handleICMP(r, pkt, hasFragmentHeader) } else { - // TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1 error - // in response to unrecognized next header values. + r.Stats().IP.PacketsDelivered.Increment() switch res := e.dispatcher.DeliverTransportPacket(r, p, pkt); res { case stack.TransportPacketHandled: case stack.TransportPacketDestinationPortUnreachable: @@ -778,17 +808,40 @@ func (e *endpoint) HandlePacket(r *stack.Route, pkt *stack.PacketBuffer) { // transport protocol (e.g., UDP) has no listener, if that transport // protocol has no alternative means to inform the sender. _ = returnError(r, &icmpReasonPortUnreachable{}, pkt) + case stack.TransportPacketProtocolUnreachable: + // As per RFC 8200 section 4. (page 7): + // Extension headers are numbered from IANA IP Protocol Numbers + // [IANA-PN], the same values used for IPv4 and IPv6. When + // processing a sequence of Next Header values in a packet, the + // first one that is not an extension header [IANA-EH] indicates + // that the next item in the packet is the corresponding upper-layer + // header. + // With more related information on page 8: + // If, as a result of processing a header, the destination node is + // required to proceed to the next header but the Next Header value + // in the current header is unrecognized by the node, it should + // discard the packet and send an ICMP Parameter Problem message to + // the source of the packet, with an ICMP Code value of 1 + // ("unrecognized Next Header type encountered") and the ICMP + // Pointer field containing the offset of the unrecognized value + // within the original packet. + // + // Which when taken together indicate that an unknown protocol should + // be treated as an unrecognized next header value. + _ = returnError(r, &icmpReasonParameterProblem{ + code: header.ICMPv6UnknownHeader, + pointer: it.ParseOffset(), + }, pkt) default: panic(fmt.Sprintf("unrecognized result from DeliverTransportPacket = %d", res)) } } default: - // If we receive a packet for an extension header we do not yet handle, - // drop the packet for now. - // - // TODO(b/152019344): Send an ICMPv6 Parameter Problem, Code 1 error - // in response to unrecognized next header values. + _ = returnError(r, &icmpReasonParameterProblem{ + code: header.ICMPv6UnknownHeader, + pointer: it.ParseOffset(), + }, pkt) r.Stats().UnknownProtocolRcvdPackets.Increment() return } |