chiark / gitweb /
Improve the SLIP driver: allow dynamic creation of SLIP interfaces.
[tripe] / tun-linux.c
CommitLineData
37075862 1/* -*-c-*-
2 *
3cdc3f3a 3 * $Id$
37075862 4 *
5 * Tunnel interface based on Linux TUN/TAP driver
6 *
7 * (c) 2003 Straylight/Edgeware
8 */
9
10/*----- Licensing notice --------------------------------------------------*
11 *
12 * This file is part of Trivial IP Encryption (TrIPE).
13 *
14 * TrIPE is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
18 *
19 * TrIPE is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
23 *
24 * You should have received a copy of the GNU General Public License
25 * along with TrIPE; if not, write to the Free Software Foundation,
26 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
27 */
28
37075862 29/*----- Header files ------------------------------------------------------*/
30
31#include "tripe.h"
32
33#include <sys/ioctl.h>
34
35/*----- Main code ---------------------------------------------------------*/
36
37#if TUN_TYPE != TUN_LINUX
38# error "Tunnel type mismatch: fix the Makefile"
39#endif
40
41/* --- @t_read@ --- *
42 *
43 * Arguments: @int fd@ = file descriptor to read
44 * @unsigned mode@ = what's happened
45 * @void *v@ = pointer to tunnel block
46 *
47 * Returns: ---
48 *
49 * Use: Reads data from the tunnel.
50 */
51
52static void t_read(int fd, unsigned mode, void *v)
53{
54 tunnel *t = v;
55 ssize_t n;
56 buf b;
57
58 n = read(fd, buf_i, sizeof(buf_i));
59 if (n < 0) {
3cdc3f3a 60 a_warn("TUN %s read-error -- %s", t->ifn, strerror(errno));
37075862 61 return;
62 }
63 IF_TRACING(T_TUNNEL, {
64 trace(T_TUNNEL, "tunnel: packet arrived");
65 trace_block(T_PACKET, "tunnel: packet contents", buf_i, n);
66 })
67 buf_init(&b, buf_i, n);
68 p_tun(t->p, &b);
69}
70
71/* --- @tun_init@ --- *
72 *
73 * Arguments: ---
74 *
75 * Returns: ---
76 *
77 * Use: Initializes the tunneling system. Maybe this will require
78 * opening file descriptors or something.
79 */
80
81void tun_init(void)
82{
83 return;
84}
85
86/* --- @tun_create@ --- *
87 *
88 * Arguments: @tunnel *t@ = pointer to tunnel block
89 * @peer *p@ = pointer to peer block
90 *
91 * Returns: Zero if it worked, nonzero on failure.
92 *
93 * Use: Initializes a new tunnel.
94 */
95
96int tun_create(tunnel *t, peer *p)
97{
98 int fd;
99 int f;
100 struct ifreq iff;
101
102 if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
3cdc3f3a 103 a_warn("TUN - open-error /dev/net/tun -- %s", strerror(errno));
37075862 104 return (-1);
105 }
106 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
107 iff.ifr_name[0] = 0;
b9066fbb 108 iff.ifr_flags = IFF_TUN | IFF_NO_PI;
37075862 109 if ((f = ioctl(fd, TUNSETIFF, &iff)) < 0) {
3cdc3f3a 110 a_warn("TUN - linux config-error -- %s", strerror(errno));
37075862 111 close(fd);
112 return (-1);
113 }
114 t->p = p;
115 sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
116 sel_addfile(&t->f);
117 iff.ifr_name[IFNAMSIZ - 1] = 0;
118 strcpy(t->ifn, iff.ifr_name);
119 T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'",
120 t->ifn, p_name(p)); )
121 return (0);
122}
123
124/* --- @tun_ifname@ --- *
125 *
126 * Arguments: @tunnel *t@ = pointer to tunnel block
127 *
128 * Returns: A pointer to the tunnel's interface name.
129 */
130
131const char *tun_ifname(tunnel *t)
132{
133 return (t->ifn);
134}
135
136/* --- @tun_inject@ --- *
137 *
138 * Arguments: @tunnel *t@ = pointer to tunnel block
139 * @buf *b@ = buffer to send
140 *
141 * Returns: ---
142 *
143 * Use: Injects a packet into the local network stack.
144 */
145
146void tun_inject(tunnel *t, buf *b)
147{
148 IF_TRACING(T_TUNNEL, {
149 trace(T_TUNNEL, "tunnel: inject decrypted packet");
150 trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
151 })
152 write(t->f.fd, BBASE(b), BLEN(b));
153}
154
155/* --- @tun_destroy@ --- *
156 *
157 * Arguments: @tunnel *t@ = pointer to tunnel block
158 *
159 * Returns: ---
160 *
161 * Use: Destroys a tunnel.
162 */
163
164void tun_destroy(tunnel *t)
165{
166 sel_rmfile(&t->f);
167 close(t->f.fd);
168}
169
170/*----- That's all, folks -------------------------------------------------*/