func (icmp *Icmp) ProcessICMPv6(
flowID *flows.FlowID,
icmp6 *layers.ICMPv6,
pkt *protos.Packet,
) {
typ := uint8(icmp6.TypeCode >> 8)
code := uint8(icmp6.TypeCode)
id, seq := extractTrackingData(6, typ, &icmp6.BaseLayer)
tuple := &icmpTuple{
IcmpVersion: 6,
SrcIp: pkt.Tuple.Src_ip,
DstIp: pkt.Tuple.Dst_ip,
Id: id,
Seq: seq,
}
msg := &icmpMessage{
Ts: pkt.Ts,
Type: typ,
Code: code,
Length: len(icmp6.BaseLayer.Payload),
}
if isRequest(tuple, msg) {
if flowID != nil {
flowID.AddICMPv6Request(id)
}
icmp.processRequest(tuple, msg)
} else {
if flowID != nil {
flowID.AddICMPv6Response(id)
}
icmp.processResponse(tuple, msg)
}
}
func (icmp *icmpPlugin) ProcessICMPv4(
flowID *flows.FlowID,
icmp4 *layers.ICMPv4,
pkt *protos.Packet,
) {
typ := uint8(icmp4.TypeCode >> 8)
code := uint8(icmp4.TypeCode)
id, seq := extractTrackingData(4, typ, &icmp4.BaseLayer)
tuple := &icmpTuple{
icmpVersion: 4,
srcIP: pkt.Tuple.SrcIP,
dstIP: pkt.Tuple.DstIP,
id: id,
seq: seq,
}
msg := &icmpMessage{
ts: pkt.Ts,
Type: typ,
code: code,
length: len(icmp4.BaseLayer.Payload),
}
if isRequest(tuple, msg) {
if flowID != nil {
flowID.AddICMPv4Request(id)
}
icmp.processRequest(tuple, msg)
} else {
if flowID != nil {
flowID.AddICMPv4Response(id)
}
icmp.processResponse(tuple, msg)
}
}
func (tcp *Tcp) Process(id *flows.FlowID, tcphdr *layers.TCP, pkt *protos.Packet) {
// This Recover should catch all exceptions in
// protocol modules.
defer logp.Recover("Process tcp exception")
debugf("tcp flow id: %p", id)
stream, created := tcp.getStream(pkt)
if stream.conn == nil {
return
}
if id != nil {
id.AddConnectionID(uint64(stream.conn.id))
}
conn := stream.conn
tcp_start_seq := tcphdr.Seq
tcp_seq := tcp_start_seq + uint32(len(pkt.Payload))
lastSeq := conn.lastSeq[stream.dir]
if isDebug {
debugf("pkt.start_seq=%v pkt.last_seq=%v stream.last_seq=%v (len=%d)",
tcp_start_seq, tcp_seq, lastSeq, len(pkt.Payload))
}
if len(pkt.Payload) > 0 && lastSeq != 0 {
if tcpSeqBeforeEq(tcp_seq, lastSeq) {
if isDebug {
debugf("Ignoring retransmitted segment. pkt.seq=%v len=%v stream.seq=%v",
tcphdr.Seq, len(pkt.Payload), lastSeq)
}
return
}
if tcpSeqBefore(lastSeq, tcp_start_seq) {
if !created {
gap := int(tcp_start_seq - lastSeq)
logp.Warn("Gap in tcp stream. last_seq: %d, seq: %d, gap: %d", lastSeq, tcp_start_seq, gap)
drop := stream.gapInStream(gap)
if drop {
if isDebug {
debugf("Dropping connection state because of gap")
}
// drop application layer connection state and
// update stream_id for app layer analysers using stream_id for lookups
conn.id = tcp.getId()
conn.data = nil
}
}
}
}
conn.lastSeq[stream.dir] = tcp_seq
stream.addPacket(pkt, tcphdr)
}
func (tcp *Tcp) Process(id *flows.FlowID, tcphdr *layers.TCP, pkt *protos.Packet) {
// This Recover should catch all exceptions in
// protocol modules.
defer logp.Recover("Process tcp exception")
stream, created := tcp.getStream(pkt)
if stream.conn == nil {
return
}
conn := stream.conn
if id != nil {
id.AddConnectionID(uint64(conn.id))
}
if isDebug {
debugf("tcp flow id: %p", id)
}
if len(pkt.Payload) == 0 && !tcphdr.FIN {
// return early if packet is not interesting. Still need to find/create
// stream first in order to update the TCP stream timer
return
}
tcpStartSeq := tcphdr.Seq
tcpSeq := tcpStartSeq + uint32(len(pkt.Payload))
lastSeq := conn.lastSeq[stream.dir]
if isDebug {
debugf("pkt.start_seq=%v pkt.last_seq=%v stream.last_seq=%v (len=%d)",
tcpStartSeq, tcpSeq, lastSeq, len(pkt.Payload))
}
if len(pkt.Payload) > 0 && lastSeq != 0 {
if tcpSeqBeforeEq(tcpSeq, lastSeq) {
if isDebug {
debugf("Ignoring retransmitted segment. pkt.seq=%v len=%v stream.seq=%v",
tcphdr.Seq, len(pkt.Payload), lastSeq)
}
return
}
switch tcpSeqCompare(lastSeq, tcpStartSeq) {
case seqLT: // lastSeq < tcpStartSeq => Gap in tcp stream detected
if created {
break
}
gap := int(tcpStartSeq - lastSeq)
debugf("Gap in tcp stream. last_seq: %d, seq: %d, gap: %d", lastSeq, tcpStartSeq, gap)
drop := stream.gapInStream(gap)
if drop {
if isDebug {
debugf("Dropping connection state because of gap")
}
droppedBecauseOfGaps.Add(1)
// drop application layer connection state and
// update stream_id for app layer analysers using stream_id for lookups
conn.id = tcp.getId()
conn.data = nil
}
case seqGT:
// lastSeq > tcpStartSeq => overlapping TCP segment detected. shrink packet
delta := lastSeq - tcpStartSeq
if isDebug {
debugf("Overlapping tcp segment. last_seq %d, seq: %d, delta: %d",
lastSeq, tcpStartSeq, delta)
}
pkt.Payload = pkt.Payload[delta:]
tcphdr.Seq += delta
}
}
conn.lastSeq[stream.dir] = tcpSeq
stream.addPacket(pkt, tcphdr)
}