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 * tun_dev.c,v 1.2.2.1.2.1 2006/11/16 04:04:40 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 #include <errno.h>
32
33 /* #include "vtun.h"
34 #include "lib.h" */
35
36 /*
37 * Allocate TUN device, returns opened fd.
38 * Stores dev name in the first arg(must be large enough).
39 */
tun_open(char * dev)40 int tun_open(char *dev)
41 {
42 char tunname[14];
43 int i, fd;
44
45 if( *dev ) {
46 sprintf(tunname, "/dev/%s", dev);
47 return open(tunname, O_RDWR);
48 }
49
50 for(i=0; i < 255; i++){
51 sprintf(tunname, "/dev/tun%d", i);
52 /* Open device */
53 if( (fd=open(tunname, O_RDWR)) > 0 ){
54 sprintf(dev, "tun%d", i);
55 return fd;
56 }
57 }
58 return -1;
59 }
60
tun_close(int fd,char * dev)61 int tun_close(int fd, char *dev)
62 {
63 return close(fd);
64 }
65
66 /* Read/write frames from TUN device */
tun_write(int fd,char * buf,int len)67 int tun_write(int fd, char *buf, int len)
68 {
69 return write(fd, buf, len);
70 }
71
tun_read(int fd,char * buf,int len)72 int tun_read(int fd, char *buf, int len)
73 {
74 return read(fd, buf, len);
75 }
76
tun_last_error()77 const char *tun_last_error()
78 {
79 return strerror(errno);
80 }
81