mirror of
https://github.com/xjasonlyu/tun2socks.git
synced 2025-11-01 04:22:44 +08:00
60 lines
1021 B
Go
60 lines
1021 B
Go
package packet
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import (
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"encoding/binary"
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"net"
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)
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const (
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IPVERSION_4 = 4
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IPVERSION_6 = 6
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PROTOCOL_ICMP = 1
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PROTOCOL_TCP = 6
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PROTOCOL_UDP = 17
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)
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func PeekIPVersion(data []byte) uint8 {
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return uint8((data[0] & 0xf0) >> 4)
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}
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func PeekProtocol(data []byte) string {
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switch uint8(data[9]) {
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case PROTOCOL_ICMP:
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return "icmp"
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case PROTOCOL_TCP:
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return "tcp"
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case PROTOCOL_UDP:
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return "udp"
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default:
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return "unknown"
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}
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}
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func PeekSourceAddress(data []byte) net.IP {
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return net.IP(data[12:16])
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}
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func PeekSourcePort(data []byte) uint16 {
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ihl := uint8(data[0] & 0x0f)
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return binary.BigEndian.Uint16(data[ihl*4 : ihl*4+2])
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}
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func PeekDestinationAddress(data []byte) net.IP {
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return net.IP(data[16:20])
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}
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func PeekDestinationPort(data []byte) uint16 {
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ihl := uint8(data[0] & 0x0f)
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return binary.BigEndian.Uint16(data[ihl*4+2 : ihl*4+4])
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}
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func IsSYNSegment(data []byte) bool {
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ihl := uint8(data[0] & 0x0f)
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if uint8(data[ihl*4+13]&(1<<1)) == 0 {
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return false
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} else {
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return true
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}
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}
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