mirror of
https://github.com/XTLS/Xray-core.git
synced 2024-08-24 05:36:27 +00:00
51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
// +build linux
|
|
|
|
package tcp
|
|
|
|
import (
|
|
"syscall"
|
|
"unsafe"
|
|
|
|
"github.com/xtls/xray-core/transport/internet/stat"
|
|
|
|
"github.com/xtls/xray-core/common/net"
|
|
)
|
|
|
|
const SO_ORIGINAL_DST = 80
|
|
|
|
func GetOriginalDestination(conn stat.Connection) (net.Destination, error) {
|
|
sysrawconn, f := conn.(syscall.Conn)
|
|
if !f {
|
|
return net.Destination{}, newError("unable to get syscall.Conn")
|
|
}
|
|
rawConn, err := sysrawconn.SyscallConn()
|
|
if err != nil {
|
|
return net.Destination{}, newError("failed to get sys fd").Base(err)
|
|
}
|
|
var dest net.Destination
|
|
err = rawConn.Control(func(fd uintptr) {
|
|
level := syscall.IPPROTO_IP
|
|
if conn.RemoteAddr().String()[0] == '[' {
|
|
level = syscall.IPPROTO_IPV6
|
|
}
|
|
addr, err := syscall.GetsockoptIPv6MTUInfo(int(fd), level, SO_ORIGINAL_DST)
|
|
if err != nil {
|
|
newError("failed to call getsockopt").Base(err).WriteToLog()
|
|
return
|
|
}
|
|
ip := (*[4]byte)(unsafe.Pointer(&addr.Addr.Flowinfo))[:4]
|
|
if level == syscall.IPPROTO_IPV6 {
|
|
ip = addr.Addr.Addr[:]
|
|
}
|
|
port := (*[2]byte)(unsafe.Pointer(&addr.Addr.Port))[:2]
|
|
dest = net.TCPDestination(net.IPAddress(ip), net.PortFromBytes(port))
|
|
})
|
|
if err != nil {
|
|
return net.Destination{}, newError("failed to control connection").Base(err)
|
|
}
|
|
if !dest.IsValid() {
|
|
return net.Destination{}, newError("failed to call getsockopt")
|
|
}
|
|
return dest, nil
|
|
}
|