github.com/Uhtred009/v2ray-core-1@v4.31.2+incompatible/transport/internet/udp/hub_linux.go (about)

     1  // +build linux
     2  
     3  package udp
     4  
     5  import (
     6  	"syscall"
     7  
     8  	"golang.org/x/sys/unix"
     9  	"v2ray.com/core/common/net"
    10  )
    11  
    12  func RetrieveOriginalDest(oob []byte) net.Destination {
    13  	msgs, err := syscall.ParseSocketControlMessage(oob)
    14  	if err != nil {
    15  		return net.Destination{}
    16  	}
    17  	for _, msg := range msgs {
    18  		if msg.Header.Level == syscall.SOL_IP && msg.Header.Type == syscall.IP_RECVORIGDSTADDR {
    19  			ip := net.IPAddress(msg.Data[4:8])
    20  			port := net.PortFromBytes(msg.Data[2:4])
    21  			return net.UDPDestination(ip, port)
    22  		} else if msg.Header.Level == syscall.SOL_IPV6 && msg.Header.Type == unix.IPV6_RECVORIGDSTADDR {
    23  			ip := net.IPAddress(msg.Data[8:24])
    24  			port := net.PortFromBytes(msg.Data[2:4])
    25  			return net.UDPDestination(ip, port)
    26  		}
    27  	}
    28  	return net.Destination{}
    29  }
    30  
    31  func ReadUDPMsg(conn *net.UDPConn, payload []byte, oob []byte) (int, int, int, *net.UDPAddr, error) {
    32  	return conn.ReadMsgUDP(payload, oob)
    33  }