diff options
Diffstat (limited to 'pkg/tcpip/link/sniffer/sniffer.go')
| -rw-r--r-- | pkg/tcpip/link/sniffer/sniffer.go | 65 |
1 files changed, 49 insertions, 16 deletions
diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go index be2537a82..0799c8f4d 100644 --- a/pkg/tcpip/link/sniffer/sniffer.go +++ b/pkg/tcpip/link/sniffer/sniffer.go @@ -171,11 +171,7 @@ func (e *endpoint) GSOMaxSize() uint32 { func (e *endpoint) dumpPacket(prefix string, gso *stack.GSO, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer) { writer := e.writer if writer == nil && atomic.LoadUint32(&LogPackets) == 1 { - first := pkt.Header.View() - if len(first) == 0 { - first = pkt.Data.First() - } - logPacket(prefix, protocol, first, gso) + logPacket(prefix, protocol, pkt, gso) } if writer != nil && atomic.LoadUint32(&LogPacketsToPCAP) == 1 { totalLength := pkt.Header.UsedLength() + pkt.Data.Size() @@ -238,7 +234,7 @@ func (e *endpoint) WriteRawPacket(vv buffer.VectorisedView) *tcpip.Error { // Wait implements stack.LinkEndpoint.Wait. func (e *endpoint) Wait() { e.lower.Wait() } -func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.View, gso *stack.GSO) { +func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, pkt *stack.PacketBuffer, gso *stack.GSO) { // Figure out the network layer info. var transProto uint8 src := tcpip.Address("unknown") @@ -247,28 +243,49 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie size := uint16(0) var fragmentOffset uint16 var moreFragments bool + + // Create a clone of pkt, including any headers if present. Avoid allocating + // backing memory for the clone. + views := [8]buffer.View{} + vv := buffer.NewVectorisedView(0, views[:0]) + vv.AppendView(pkt.Header.View()) + vv.Append(pkt.Data) + switch protocol { case header.IPv4ProtocolNumber: - ipv4 := header.IPv4(b) + hdr, ok := vv.PullUp(header.IPv4MinimumSize) + if !ok { + return + } + ipv4 := header.IPv4(hdr) fragmentOffset = ipv4.FragmentOffset() moreFragments = ipv4.Flags()&header.IPv4FlagMoreFragments == header.IPv4FlagMoreFragments src = ipv4.SourceAddress() dst = ipv4.DestinationAddress() transProto = ipv4.Protocol() size = ipv4.TotalLength() - uint16(ipv4.HeaderLength()) - b = b[ipv4.HeaderLength():] + vv.TrimFront(int(ipv4.HeaderLength())) id = int(ipv4.ID()) case header.IPv6ProtocolNumber: - ipv6 := header.IPv6(b) + hdr, ok := vv.PullUp(header.IPv6MinimumSize) + if !ok { + return + } + ipv6 := header.IPv6(hdr) src = ipv6.SourceAddress() dst = ipv6.DestinationAddress() transProto = ipv6.NextHeader() size = ipv6.PayloadLength() - b = b[header.IPv6MinimumSize:] + vv.TrimFront(header.IPv6MinimumSize) case header.ARPProtocolNumber: - arp := header.ARP(b) + hdr, ok := vv.PullUp(header.ARPSize) + if !ok { + return + } + vv.TrimFront(header.ARPSize) + arp := header.ARP(hdr) log.Infof( "%s arp %v (%v) -> %v (%v) valid:%v", prefix, @@ -284,7 +301,7 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie // We aren't guaranteed to have a transport header - it's possible for // writes via raw endpoints to contain only network headers. - if minSize, ok := transportProtocolMinSizes[tcpip.TransportProtocolNumber(transProto)]; ok && len(b) < minSize { + if minSize, ok := transportProtocolMinSizes[tcpip.TransportProtocolNumber(transProto)]; ok && vv.Size() < minSize { log.Infof("%s %v -> %v transport protocol: %d, but no transport header found (possible raw packet)", prefix, src, dst, transProto) return } @@ -297,7 +314,11 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie switch tcpip.TransportProtocolNumber(transProto) { case header.ICMPv4ProtocolNumber: transName = "icmp" - icmp := header.ICMPv4(b) + hdr, ok := vv.PullUp(header.ICMPv4MinimumSize) + if !ok { + break + } + icmp := header.ICMPv4(hdr) icmpType := "unknown" if fragmentOffset == 0 { switch icmp.Type() { @@ -330,7 +351,11 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie case header.ICMPv6ProtocolNumber: transName = "icmp" - icmp := header.ICMPv6(b) + hdr, ok := vv.PullUp(header.ICMPv6MinimumSize) + if !ok { + break + } + icmp := header.ICMPv6(hdr) icmpType := "unknown" switch icmp.Type() { case header.ICMPv6DstUnreachable: @@ -361,7 +386,11 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie case header.UDPProtocolNumber: transName = "udp" - udp := header.UDP(b) + hdr, ok := vv.PullUp(header.UDPMinimumSize) + if !ok { + break + } + udp := header.UDP(hdr) if fragmentOffset == 0 && len(udp) >= header.UDPMinimumSize { srcPort = udp.SourcePort() dstPort = udp.DestinationPort() @@ -371,7 +400,11 @@ func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b buffer.Vie case header.TCPProtocolNumber: transName = "tcp" - tcp := header.TCP(b) + hdr, ok := vv.PullUp(header.TCPMinimumSize) + if !ok { + break + } + tcp := header.TCP(hdr) if fragmentOffset == 0 && len(tcp) >= header.TCPMinimumSize { offset := int(tcp.DataOffset()) if offset < header.TCPMinimumSize { |