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 04:04:23 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 <sys/ioctl.h>
34 #ifdef __DragonFly__
35 #include <net/tun/if_tun.h>
36 #else
37 #include <net/if_tun.h>
38 #endif
39
40 /* #include "vtun.h"
41 #include "lib.h" */
42
43 /*
44 * Allocate TUN device, returns opened fd.
45 * Stores dev name in the first arg(must be large enough).
46 */
tun_open(char * dev)47 int tun_open(char *dev)
48 {
49 char tunname[14];
50 int i, fd = -1;
51
52 if( *dev ){
53 sprintf(tunname, "/dev/%s", dev);
54 fd = open(tunname, O_RDWR);
55 } else {
56 for(i=0; i < 255; i++){
57 sprintf(tunname, "/dev/tun%d", i);
58 /* Open device */
59 if( (fd=open(tunname, O_RDWR)) > 0 ){
60 sprintf(dev, "tun%d", i);
61 break;
62 }
63 }
64 }
65 if( fd > -1 ){
66 i=0;
67 /* Disable extended modes */
68 ioctl(fd, TUNSLMODE, &i);
69 ioctl(fd, TUNSIFHEAD, &i);
70 }
71 return fd;
72 }
73
tun_close(int fd,char * dev)74 int tun_close(int fd, char *dev)
75 {
76 return close(fd);
77 }
78
79 /* Read/write frames from/to TUN device */
tun_write(int fd,char * buf,int len)80 int tun_write(int fd, char *buf, int len)
81 {
82 return write(fd, buf, len);
83 }
84
tun_read(int fd,char * buf,int len)85 int tun_read(int fd, char *buf, int len)
86 {
87 return read(fd, buf, len);
88 }
89
tun_last_error()90 const char *tun_last_error()
91 {
92 return strerror(errno);
93 }
94