diff options
Diffstat (limited to 'pkg/tcpip/link/sniffer/sniffer.go')
| -rw-r--r-- | pkg/tcpip/link/sniffer/sniffer.go | 20 |
1 files changed, 15 insertions, 5 deletions
diff --git a/pkg/tcpip/link/sniffer/sniffer.go b/pkg/tcpip/link/sniffer/sniffer.go index 3836cebb7..414a7edb4 100644 --- a/pkg/tcpip/link/sniffer/sniffer.go +++ b/pkg/tcpip/link/sniffer/sniffer.go @@ -118,7 +118,7 @@ func NewWithFile(lower tcpip.LinkEndpointID, file *os.File, snapLen uint32) (tcp // logs the packet before forwarding to the actual dispatcher. func (e *endpoint) DeliverNetworkPacket(linkEP stack.LinkEndpoint, remoteLinkAddr tcpip.LinkAddress, protocol tcpip.NetworkProtocolNumber, vv *buffer.VectorisedView) { if atomic.LoadUint32(&LogPackets) == 1 && e.file == nil { - LogPacket("recv", protocol, vv.First(), nil) + logPacket("recv", protocol, vv.First(), nil) } if e.file != nil && atomic.LoadUint32(&LogPacketsToFile) == 1 { vs := vv.Views() @@ -190,7 +190,7 @@ func (e *endpoint) LinkAddress() tcpip.LinkAddress { // the request to the lower endpoint. func (e *endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload buffer.View, protocol tcpip.NetworkProtocolNumber) *tcpip.Error { if atomic.LoadUint32(&LogPackets) == 1 && e.file == nil { - LogPacket("send", protocol, hdr.UsedBytes(), payload) + logPacket("send", protocol, hdr.UsedBytes(), payload) } if e.file != nil && atomic.LoadUint32(&LogPacketsToFile) == 1 { hdrBuf := hdr.UsedBytes() @@ -226,8 +226,7 @@ func (e *endpoint) WritePacket(r *stack.Route, hdr *buffer.Prependable, payload return e.lower.WritePacket(r, hdr, payload, protocol) } -// LogPacket logs the given packet. -func LogPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b, plb []byte) { +func logPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b, plb []byte) { // Figure out the network layer info. var transProto uint8 src := tcpip.Address("unknown") @@ -316,9 +315,19 @@ func LogPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b, plb []byt case header.TCPProtocolNumber: transName = "tcp" tcp := header.TCP(b) + offset := int(tcp.DataOffset()) + if offset < header.TCPMinimumSize { + details += fmt.Sprintf("invalid packet: tcp data offset too small %d", offset) + break + } + if offset > len(tcp) { + details += fmt.Sprintf("invalid packet: tcp data offset %d larger than packet buffer length %d", offset, len(tcp)) + break + } + srcPort = tcp.SourcePort() dstPort = tcp.DestinationPort() - size -= uint16(tcp.DataOffset()) + size -= uint16(offset) // Initialize the TCP flags. flags := tcp.Flags() @@ -334,6 +343,7 @@ func LogPacket(prefix string, protocol tcpip.NetworkProtocolNumber, b, plb []byt } else { details += fmt.Sprintf(" options: %+v", tcp.ParsedOptions()) } + default: log.Infof("%s %v -> %v unknown transport protocol: %d", prefix, src, dst, transProto) return |