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v2fly/transport/internet/tcp/sockopt_linux.go
2017-04-18 12:35:54 +02:00

30 lines
793 B
Go

// +build linux
package tcp
import (
"net"
"syscall"
v2net "v2ray.com/core/common/net"
"v2ray.com/core/transport/internet"
"v2ray.com/core/transport/internet/internal"
)
const SO_ORIGINAL_DST = 80
func GetOriginalDestination(conn internet.Connection) (v2net.Destination, error) {
fd, err := internal.GetSysFd(conn.(net.Conn))
if err != nil {
return v2net.Destination{}, newError("failed to get original destination").Base(err)
}
addr, err := syscall.GetsockoptIPv6Mreq(fd, syscall.IPPROTO_IP, SO_ORIGINAL_DST)
if err != nil {
return v2net.Destination{}, newError("failed to call getsockopt").Base(err)
}
ip := v2net.IPAddress(addr.Multiaddr[4:8])
port := uint16(addr.Multiaddr[2])<<8 + uint16(addr.Multiaddr[3])
return v2net.TCPDestination(ip, v2net.Port(port)), nil
}