1 /*
2 VTun - Virtual Tunnel over TCP/IP network.
3
4 Copyright (C) 1998-2016 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 1.5.2.3 2016/10/01 21:37:39 mtbishop Exp $
21 */
22
23 #include "config.h"
24
25 #include <unistd.h>
26 #include <fcntl.h>
27 #include <stdlib.h>
28 #include <stdio.h>
29 #include <string.h>
30 #include <syslog.h>
31
32 #include "vtun.h"
33 #include "lib.h"
34
35 /*
36 * Allocate TUN device, returns opened fd.
37 * Stores dev name in the first arg(must be large enough).
38 */
tun_open(char * dev)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
tun_close(int fd,char * dev)60 int tun_close(int fd, char *dev)
61 {
62 return close(fd);
63 }
64
65 /* Read/write frames from TUN device */
tun_write(int fd,char * buf,int len)66 int tun_write(int fd, char *buf, int len)
67 {
68 return write(fd, buf, len);
69 }
70
tun_read(int fd,char * buf,int len)71 int tun_read(int fd, char *buf, int len)
72 {
73 return read(fd, buf, len);
74 }
75