tun.c

/****************************************************************************
 * hn70ap/apps/libhn70ap/tun.c
 *
 *   Copyright (C) 2018 Sebastien Lorquet. All rights reserved.
 *   Author: Sebastien Lorquet <sebastien@lorquet.fr>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * 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 OWNER 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.
 *
 ****************************************************************************/

#include <nuttx/config.h>

#include <string.h>

#include <fcntl.h>
#include <unistd.h>

#include <sys/ioctl.h>

#include <nuttx/net/tun.h>

#include <hn70ap/tun.h>

int hn70ap_tun_init(char ifname[IFNAMSIZ])
{
  struct ifreq ifr;
  int errcode;
  int fd;

  if ((fd = open("/dev/tun", O_RDWR)) < 0)
    {
      return fd;
    }

  memset(&ifr, 0, sizeof(ifr));
  ifr.ifr_flags = IFF_TUN;
  if (ifname[0])
    {
      strncpy(ifr.ifr_name, ifname, IFNAMSIZ);
    }

  if ((errcode = ioctl(fd, TUNSETIFF, (unsigned long)&ifr)) < 0)
    {
      close(fd);
      return errcode;
    }

  return fd;
}