diff options
Diffstat (limited to 'pkg/tcpip/network/ipv4/icmp.go')
| -rw-r--r-- | pkg/tcpip/network/ipv4/icmp.go | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/pkg/tcpip/network/ipv4/icmp.go b/pkg/tcpip/network/ipv4/icmp.go index d51c36f19..1c3b0887f 100644 --- a/pkg/tcpip/network/ipv4/icmp.go +++ b/pkg/tcpip/network/ipv4/icmp.go @@ -167,14 +167,17 @@ func (e *endpoint) handleControl(errInfo stack.TransportError, pkt *stack.Packet p := hdr.TransportProtocol() dstAddr := hdr.DestinationAddress() // Skip the ip header, then deliver the error. - pkt.Data().DeleteFront(hlen) + if _, ok := pkt.Data().Consume(hlen); !ok { + panic(fmt.Sprintf("could not consume the IP header of %d bytes", hlen)) + } e.dispatcher.DeliverTransportError(srcAddr, dstAddr, ProtocolNumber, p, errInfo, pkt) } func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { received := e.stats.icmp.packetsReceived // ICMP packets don't have their TransportHeader fields set. See - // icmp/protocol.go:protocol.Parse for a full explanation. + // icmp/protocol.go:protocol.Parse for a full explanation. Not all ICMP types + // require consuming the header, so we only call PullUp. v, ok := pkt.Data().PullUp(header.ICMPv4MinimumSize) if !ok { received.invalid.Increment() @@ -242,7 +245,8 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { // 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. + // be modifying fields. Both the ICMP header (with its type modified to + // EchoReply) and payload are reused in the reply packet. // // TODO(gvisor.dev/issue/4399): The copy may not be needed if there are no // waiting endpoints. Consider moving responsibility for doing the copy to @@ -331,6 +335,8 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { case header.ICMPv4EchoReply: received.echoReply.Increment() + // ICMP sockets expect the ICMP header to be present, so we don't consume + // the ICMP header. e.dispatcher.DeliverTransportPacket(header.ICMPv4ProtocolNumber, pkt) case header.ICMPv4DstUnreachable: @@ -338,7 +344,9 @@ func (e *endpoint) handleICMP(pkt *stack.PacketBuffer) { mtu := h.MTU() code := h.Code() - pkt.Data().DeleteFront(header.ICMPv4MinimumSize) + if _, ok := pkt.Data().Consume(header.ICMPv4MinimumSize); !ok { + panic("could not consume ICMPv4MinimumSize bytes") + } switch code { case header.ICMPv4HostUnreachable: e.handleControl(&icmpv4DestinationHostUnreachableSockError{}, pkt) |