utils_android.go

// +build android

package main

/*
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/uio.h>

#define ANCIL_FD_BUFFER(n) \
    struct { \
        struct cmsghdr h; \
        int fd[n]; \
    }

int
ancil_send_fds_with_buffer(int sock, const int *fds, unsigned n_fds, void *buffer)
{
    struct msghdr msghdr;
    char nothing = '!';
    struct iovec nothing_ptr;
    struct cmsghdr *cmsg;
    int i;

    nothing_ptr.iov_base = &nothing;
    nothing_ptr.iov_len = 1;
    msghdr.msg_name = NULL;
    msghdr.msg_namelen = 0;
    msghdr.msg_iov = &nothing_ptr;
    msghdr.msg_iovlen = 1;
    msghdr.msg_flags = 0;
    msghdr.msg_control = buffer;
    msghdr.msg_controllen = sizeof(struct cmsghdr) + sizeof(int) * n_fds;
    cmsg = CMSG_FIRSTHDR(&msghdr);
    cmsg->cmsg_len = msghdr.msg_controllen;
    cmsg->cmsg_level = SOL_SOCKET;
    cmsg->cmsg_type = SCM_RIGHTS;
    for(i = 0; i < n_fds; i++)
        ((int *)CMSG_DATA(cmsg))[i] = fds[i];
    return(sendmsg(sock, &msghdr, 0) >= 0 ? 0 : -1);
}

int
ancil_send_fd(int sock, int fd)
{
    ANCIL_FD_BUFFER(1) buffer;

    return(ancil_send_fds_with_buffer(sock, &fd, 1, &buffer));
}

void
set_timeout(int sock)
{
    struct timeval tv;
    tv.tv_sec  = 3;
    tv.tv_usec = 0;
    setsockopt(sock, SOL_SOCKET, SO_RCVTIMEO, (char *)&tv, sizeof(struct timeval));
    setsockopt(sock, SOL_SOCKET, SO_SNDTIMEO, (char *)&tv, sizeof(struct timeval));
}

*/
import "C"

import (
	"log"
	"syscall"

	vinternet "github.com/xtls/xray-core/transport/internet"
)

func ControlOnConnSetup(network string, address string, conn syscall.RawConn) error {
	return conn.Control(func(s uintptr) {
		fd := int(s)
		path := "protect_path"

		socket, err := syscall.Socket(syscall.AF_UNIX, syscall.SOCK_STREAM, 0)
		if err != nil {
			log.Println(err)
		}

		defer syscall.Close(socket)

		C.set_timeout(C.int(socket))

		err = syscall.Connect(socket, &syscall.SockaddrUnix{Name: path})
		if err != nil {
			log.Println(err)
		}

		C.ancil_send_fd(C.int(socket), C.int(fd))

		dummy := []byte{1}
		n, err := syscall.Read(socket, dummy)
		if err != nil {
			log.Println(err)
		}
		if n != 1 {
			log.Println("Failed to protect fd: ", fd)
		}
	})
}

func registerControlFunc() {
	vinternet.RegisterDialerController(ControlOnConnSetup)
	vinternet.RegisterListenerController(ControlOnConnSetup)
}