tun_dev-bsd.c

   1 /*
   2     VTun - Virtual Tunnel over TCP/IP network.
   3
   4     Copyright (C) 1998-2000  Maxim Krasnyansky <max_mk@yahoo.com>
   5
   6     VTun has been derived from VPPP package by Maxim Krasnyansky.
   7
   8     This program is free software; you can redistribute it and/or modify
   9     it under the terms of the GNU General Public License as published by
  10     the Free Software Foundation; either version 2 of the License, or
  11     (at your option) any later version.
  12
  13     This program is distributed in the hope that it will be useful,
  14     but WITHOUT ANY WARRANTY; without even the implied warranty of
  15     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16     GNU General Public License for more details.
  17  */
  18
  19 /*
  20  * $Id: tun_dev.c,v 1.1.2.2 2000/11/20 08:15:53 maxk Exp $
  21  */
  22
  23 #include <unistd.h>
  24 #include <fcntl.h>
  25 #include <stdlib.h>
  26 #include <stdio.h>
  27 #include <string.h>
  28 #include <syslog.h>
  29 #include <sys/ioctl.h>
  30
  31 #include <sys/socket.h>
  32 #include <net/if.h>
  33 #include <net/if_tun.h>
  34
  35 /*
  36  * Allocate TUN device, returns opened fd.
  37  * Stores dev name in the first arg(must be large enough).
  38  */
  39 int tun_open(char *dev)
  40 {
  41     char tunname[14];
  42     int i, fd;
  43
  44     if( *dev ) {
  45        sprintf(tunname, "/dev/%s", dev);
  46        return open(tunname, O_RDWR);
  47     }
  48
  49     for(i=0; i < 255; i++){
  50        sprintf(tunname, "/dev/tun%d", i);
  51        /* Open device */
  52        if( (fd=open(tunname, O_RDWR)) > 0 ){
  53           sprintf(dev, "tun%d", i);
  54           return fd;
  55        }
  56     }
  57     return -1;
  58 }
  59
  60 int tun_close(int fd, char *dev)
  61 {
  62     return close(fd);
  63 }
  64
  65 /* Read/write frames from TUN device */
  66 int tun_write(int fd, char *buf, int len)
  67 {
  68     return write(fd, buf, len);
  69 }
  70
  71 int tun_read(int fd, char *buf, int len)
  72 {
  73     return read(fd, buf, len);
  74 }