/* -*- mode: c; c-file-style: "openbsd" -*- */

#include "lldpd.h"

#include <sys/param.h>

#include <sys/uio.h>

#include <sys/types.h>

#include <sys/socket.h>

#include <sys/stat.h>

#include <errno.h>

#include <fcntl.h>

#include <signal.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <unistd.h>

/*

 * Copyright 2001 Niels Provos <provos@citi.umich.edu>

 * All rights reserved.

 *

 * Copyright (c) 2002 Matthieu Herrb

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 *    - Redistributions of source code must retain the above copyright

 *      notice, this list of conditions and the following disclaimer.

 *    - Redistributions in binary form must reproduce the above

 *      copyright notice, this list of conditions and the following

 *      disclaimer in the documentation and/or other materials provided

 *      with the distribution.

 *

 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS

 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT

 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS

 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE

 * COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,

 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,

 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER

 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN

 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE

 * POSSIBILITY OF SUCH DAMAGE.

 */

void

send_fd(enum priv_context ctx, int fd)

{

  struct msghdr msg;

  union {

    struct cmsghdr hdr;

    char buf[CMSG_SPACE(sizeof(int))];

  } cmsgbuf;

  struct cmsghdr *cmsg;

  struct iovec vec;

  int result = 0;

  ssize_t n;

  memset(&msg, 0, sizeof(msg));

  memset(&cmsgbuf.buf, 0, sizeof(cmsgbuf.buf));

  if (fd >= 0) {

    msg.msg_control = (caddr_t)&cmsgbuf.buf;

    msg.msg_controllen = sizeof(cmsgbuf.buf);

    cmsg = CMSG_FIRSTHDR(&msg);

    cmsg->cmsg_len = CMSG_LEN(sizeof(int));

    cmsg->cmsg_level = SOL_SOCKET;

    cmsg->cmsg_type = SCM_RIGHTS;

    memcpy(CMSG_DATA(cmsg), &fd, sizeof(int));

  } else {

    result = errno;

  }

  vec.iov_base = &result;

  vec.iov_len = sizeof(int);

  msg.msg_iov = &vec;

  msg.msg_iovlen = 1;

  if ((n = sendmsg(priv_fd(ctx), &msg, 0)) == -1)

    log_warn("privsep", "sendmsg(%d)", priv_fd(ctx));

  if (n != sizeof(int))

    log_warnx("privsep", "sendmsg: expected sent 1 got %ld", (long)n);

}

int

receive_fd(enum priv_context ctx)

{

  struct msghdr msg;

  union {

    struct cmsghdr hdr;

    char buf[CMSG_SPACE(sizeof(int))];

  } cmsgbuf;

  struct cmsghdr *cmsg;

  struct iovec vec;

  ssize_t n;

  int result;

  int fd;

  memset(&msg, 0, sizeof(msg));

  vec.iov_base = &result;

  vec.iov_len = sizeof(int);

  msg.msg_iov = &vec;

  msg.msg_iovlen = 1;

  msg.msg_control = &cmsgbuf.buf;

  msg.msg_controllen = sizeof(cmsgbuf.buf);

  if ((n = recvmsg(priv_fd(ctx), &msg, 0)) == -1) log_warn("privsep", "recvmsg");

  if (n != sizeof(int))

    log_warnx("privsep", "recvmsg: expected received 1 got %ld", (long)n);

  if (result == 0) {

    cmsg = CMSG_FIRSTHDR(&msg);

    if (cmsg == NULL) {

      log_warnx("privsep", "no message header");

      return -1;

    }

    if (cmsg->cmsg_type != SCM_RIGHTS)

      log_warnx("privsep", "expected type %d got %d", SCM_RIGHTS,

          cmsg->cmsg_type);

    memcpy(&fd, CMSG_DATA(cmsg), sizeof(int));

    return fd;

  } else {

    errno = result;

    return -1;

  }

}