mirror of https://github.com/XTLS/Xray-core
73 lines
2.1 KiB
Go
73 lines
2.1 KiB
Go
// +build linux
|
|
|
|
package dokodemo
|
|
|
|
import (
|
|
"fmt"
|
|
"net"
|
|
"os"
|
|
"syscall"
|
|
)
|
|
|
|
func FakeUDP(addr *net.UDPAddr, mark int) (net.PacketConn, error) {
|
|
|
|
localSocketAddress, af, err := udpAddrToSocketAddr(addr)
|
|
if err != nil {
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("build local socket address: %s", err)}
|
|
}
|
|
|
|
fileDescriptor, err := syscall.Socket(af, syscall.SOCK_DGRAM, 0)
|
|
if err != nil {
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("socket open: %s", err)}
|
|
}
|
|
|
|
if mark != 0 {
|
|
if err = syscall.SetsockoptInt(fileDescriptor, syscall.SOL_SOCKET, syscall.SO_MARK, mark); err != nil {
|
|
syscall.Close(fileDescriptor)
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("set socket option: SO_MARK: %s", err)}
|
|
}
|
|
}
|
|
|
|
if err = syscall.SetsockoptInt(fileDescriptor, syscall.SOL_SOCKET, syscall.SO_REUSEADDR, 1); err != nil {
|
|
syscall.Close(fileDescriptor)
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("set socket option: SO_REUSEADDR: %s", err)}
|
|
}
|
|
|
|
if err = syscall.SetsockoptInt(fileDescriptor, syscall.SOL_IP, syscall.IP_TRANSPARENT, 1); err != nil {
|
|
syscall.Close(fileDescriptor)
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("set socket option: IP_TRANSPARENT: %s", err)}
|
|
}
|
|
|
|
if err = syscall.Bind(fileDescriptor, localSocketAddress); err != nil {
|
|
syscall.Close(fileDescriptor)
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("socket bind: %s", err)}
|
|
}
|
|
|
|
fdFile := os.NewFile(uintptr(fileDescriptor), fmt.Sprintf("net-udp-fake-%s", addr.String()))
|
|
defer fdFile.Close()
|
|
|
|
packetConn, err := net.FilePacketConn(fdFile)
|
|
if err != nil {
|
|
syscall.Close(fileDescriptor)
|
|
return nil, &net.OpError{Op: "fake", Err: fmt.Errorf("convert file descriptor to connection: %s", err)}
|
|
}
|
|
|
|
return packetConn, nil
|
|
}
|
|
|
|
func udpAddrToSocketAddr(addr *net.UDPAddr) (syscall.Sockaddr, int, error) {
|
|
switch {
|
|
case addr.IP.To4() != nil:
|
|
ip := [4]byte{}
|
|
copy(ip[:], addr.IP.To4())
|
|
|
|
return &syscall.SockaddrInet4{Addr: ip, Port: addr.Port}, syscall.AF_INET, nil
|
|
|
|
default:
|
|
ip := [16]byte{}
|
|
copy(ip[:], addr.IP.To16())
|
|
|
|
return &syscall.SockaddrInet6{Addr: ip, Port: addr.Port, ZoneId: 0}, syscall.AF_INET6, nil
|
|
}
|
|
}
|