package main

import (
	"net"
	"syscall"
)

func uidPair(conn *net.UnixConn) (int, error) {
	brut, err := conn.SyscallConn()
	if err != nil {
		return -1, err
	}
	var cred *syscall.Ucred
	var errCred error
	if err := brut.Control(func(fd uintptr) {
		cred, errCred = syscall.GetsockoptUcred(int(fd), syscall.SOL_SOCKET, syscall.SO_PEERCRED)
	}); err != nil {
		return -1, err
	}
	if errCred != nil {
		return -1, errCred
	}
	return int(cred.Uid), nil
}