v2ray-core/transport/internet/udp/sourceForgeSender.go

56 lines
1.1 KiB
Go

// +build linux
package udp
import (
"net"
"os"
"syscall"
)
//Currently, Only IPv4 Forge is supported
func TransmitSocket(src net.Addr, dst net.Addr) (net.Conn, error) {
var fd int
var err error
fd, err = syscall.Socket(syscall.AF_INET, syscall.SOCK_DGRAM, 0)
if err != nil {
return nil, err
}
err = syscall.SetsockoptInt(fd, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1)
if err != nil {
return nil, err
}
err = syscall.SetsockoptInt(fd, syscall.SOL_IP, syscall.IP_TRANSPARENT, 1)
if err != nil {
return nil, err
}
ip := src.(*net.UDPAddr).IP.To4()
var ip2 [4]byte
copy(ip2[:], ip)
srcaddr := syscall.SockaddrInet4{}
srcaddr.Addr = ip2
srcaddr.Port = src.(*net.UDPAddr).Port
err = syscall.Bind(fd, &srcaddr)
if err != nil {
return nil, err
}
ipd := dst.(*net.UDPAddr).IP.To4()
var ip2d [4]byte
copy(ip2d[:], ipd)
dstaddr := syscall.SockaddrInet4{}
dstaddr.Addr = ip2d
dstaddr.Port = dst.(*net.UDPAddr).Port
err = syscall.Connect(fd, &dstaddr)
if err != nil {
return nil, err
}
fdf := os.NewFile(uintptr(fd), "/dev/udp/")
c, err := net.FileConn(fdf)
if err != nil {
return nil, err
}
return c, nil
}