// GapInStream is called by TCP layer when a packets are missing from the tcp
// stream.
func (mc *Memcache) GapInStream(
tcptuple *common.TcpTuple,
dir uint8, nbytes int,
private protos.ProtocolData,
) (priv protos.ProtocolData, drop bool) {
debug("memcache(tcp) stream gap detected")
defer logp.Recover("GapInStream(memcache) exception")
if !isMemcacheConnection(private) {
return private, false
}
conn := private.(*tcpConnectionData)
stream := conn.Streams[dir]
parser := stream.parser
msg := parser.message
if msg != nil {
if msg.IsRequest {
msg.AddNotes(NoteRequestPacketLoss)
} else {
msg.AddNotes(NoteResponsePacketLoss)
}
}
// If we are about to read binary data (length) encoded, but missing gab
// does fully cover data area, we might be able to continue processing the
// stream + transactions
inData := parser.state == parseStateDataBinary ||
parser.state == parseStateIncompleteDataBinary ||
parser.state == parseStateData ||
parser.state == parseStateIncompleteData
if inData {
if msg == nil {
logp.WTF("parser message is nil on data load")
return private, true
}
alreadyRead := stream.Buf.Len() - int(msg.bytesLost)
dataRequired := int(msg.bytes) - alreadyRead
if nbytes <= dataRequired {
// yay, all bytes included in message binary data part.
// just drop binary data part and recover parsing.
if msg.isBinary {
parser.state = parseStateIncompleteDataBinary
} else {
parser.state = parseStateIncompleteData
}
msg.bytesLost += uint(nbytes)
return private, false
}
}
// need to drop TCP stream. But try to publish all cached trancsactions first
mc.pushAllTCPTrans(conn.connection)
return private, true
}
func requiresCounterpart(tuple *icmpTuple, msg *icmpMessage) bool {
if tuple.IcmpVersion == 4 {
return icmp4PairTypes[msg.Type]
}
if tuple.IcmpVersion == 6 {
return icmp6PairTypes[msg.Type]
}
logp.WTF("icmp", "Invalid ICMP version[%d]", tuple.IcmpVersion)
return false
}
func isError(tuple *icmpTuple, msg *icmpMessage) bool {
if tuple.IcmpVersion == 4 {
return icmp4ErrorTypes[msg.Type]
}
if tuple.IcmpVersion == 6 {
return icmp6ErrorTypes[msg.Type]
}
logp.WTF("icmp", "Invalid ICMP version[%d]", tuple.IcmpVersion)
return true
}
func isRequest(tuple *icmpTuple, msg *icmpMessage) bool {
if tuple.IcmpVersion == 4 {
return !icmp4ResponseTypes[msg.Type]
}
if tuple.IcmpVersion == 6 {
return !icmp6ResponseTypes[msg.Type]
}
logp.WTF("icmp", "Invalid ICMP version[%d]", tuple.IcmpVersion)
return true
}
func humanReadable(tuple *icmpTuple, msg *icmpMessage) string {
if tuple.IcmpVersion == 4 {
return layers.ICMPv4TypeCode(binary.BigEndian.Uint16([]byte{msg.Type, msg.Code})).String()
}
if tuple.IcmpVersion == 6 {
return layers.ICMPv6TypeCode(binary.BigEndian.Uint16([]byte{msg.Type, msg.Code})).String()
}
logp.WTF("icmp", "Invalid ICMP version[%d]", tuple.IcmpVersion)
return ""
}
func extractTrackingData(icmpVersion uint8, msgType uint8, baseLayer *layers.BaseLayer) (uint16, uint16) {
if icmpVersion == 4 {
if icmp4PairTypes[msgType] {
id := binary.BigEndian.Uint16(baseLayer.Contents[4:6])
seq := binary.BigEndian.Uint16(baseLayer.Contents[6:8])
return id, seq
}
return 0, 0
}
if icmpVersion == 6 {
if icmp6PairTypes[msgType] {
id := binary.BigEndian.Uint16(baseLayer.Contents[4:6])
seq := binary.BigEndian.Uint16(baseLayer.Contents[6:8])
return id, seq
}
return 0, 0
}
logp.WTF("icmp", "Invalid ICMP version[%d]", icmpVersion)
return 0, 0
}
func (mc *Memcache) InitDefaults() {
if err := mc.Ports.Init(11211); err != nil {
logp.WTF("memcache default port number invalid")
}
mc.handler = mc
}
