refactor: engine/tcp/worker perf improvements

2026-05-12 15:16:11 +00:00
parent dc16b979e7
commit ecc2cde1c2
9 changed files with 743 additions and 546 deletions
@@ -0,0 +1,91 @@
+package engine
+
+import "net"
+
+type L3Info struct {
+	Version  uint8
+	Protocol uint8
+	IHL      uint8
+	SrcIP    [4]byte
+	DstIP    [4]byte
+	Length   uint16
+}
+
+func (i L3Info) SrcIPAddr() net.IP { return net.IP(i.SrcIP[:]) }
+func (i L3Info) DstIPAddr() net.IP { return net.IP(i.DstIP[:]) }
+
+type TCPInfo struct {
+	SrcPort uint16
+	DstPort uint16
+	Seq     uint32
+	Ack     uint32
+	HdrLen  uint8
+	SYN     bool
+	FIN     bool
+	RST     bool
+	ACK     bool
+}
+
+type UDPInfo struct {
+	SrcPort uint16
+	DstPort uint16
+}
+
+func ParseL3(data []byte) (l3 L3Info, transport []byte, ok bool) {
+	if len(data) < 20 {
+		return
+	}
+	version := data[0] >> 4
+	if version != 4 {
+		return
+	}
+	ihl := data[0] & 0x0F
+	if ihl < 5 || len(data) < int(ihl)*4 {
+		return
+	}
+	totalLen := int(uint16(data[2])<<8 | uint16(data[3]))
+	if totalLen < int(ihl)*4 || totalLen > len(data) {
+		totalLen = len(data)
+	}
+	return L3Info{
+		Version:  4,
+		Protocol: data[9],
+		IHL:      ihl,
+		Length:   uint16(totalLen),
+		SrcIP:    [4]byte{data[12], data[13], data[14], data[15]},
+		DstIP:    [4]byte{data[16], data[17], data[18], data[19]},
+	}, data[ihl*4:totalLen], true
+}
+
+func ParseTCP(transport []byte) (TCPInfo, []byte, bool) {
+	if len(transport) < 20 {
+		return TCPInfo{}, nil, false
+	}
+	dataOff := uint8(transport[12]>>4) * 4
+	if dataOff < 20 || len(transport) < int(dataOff) {
+		return TCPInfo{}, nil, false
+	}
+	flags := transport[13]
+	payloadLen := len(transport) - int(dataOff)
+	return TCPInfo{
+		SrcPort: uint16(transport[0])<<8 | uint16(transport[1]),
+		DstPort: uint16(transport[2])<<8 | uint16(transport[3]),
+		Seq:     uint32(transport[4])<<24 | uint32(transport[5])<<16 | uint32(transport[6])<<8 | uint32(transport[7]),
+		Ack:     uint32(transport[8])<<24 | uint32(transport[9])<<16 | uint32(transport[10])<<8 | uint32(transport[11]),
+		HdrLen:  dataOff,
+		SYN:     flags&0x02 != 0,
+		FIN:     flags&0x01 != 0,
+		RST:     flags&0x04 != 0,
+		ACK:     flags&0x10 != 0,
+	}, transport[dataOff : dataOff+uint8(payloadLen)], true
+}
+
+func ParseUDP(transport []byte) (UDPInfo, []byte, bool) {
+	if len(transport) < 8 {
+		return UDPInfo{}, nil, false
+	}
+	return UDPInfo{
+		SrcPort: uint16(transport[0])<<8 | uint16(transport[1]),
+		DstPort: uint16(transport[2])<<8 | uint16(transport[3]),
+	}, transport[8:], true
+}