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Support Linux TUN/TAP device. Fix some bugs.
[tripe] / tun-linux.c
CommitLineData
37075862 1/* -*-c-*-
2 *
3 * $Id: tun-linux.c,v 1.1 2003/04/06 10:25:17 mdw Exp $
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
29/*----- Revision history --------------------------------------------------*
30 *
31 * $Log: tun-linux.c,v $
32 * Revision 1.1 2003/04/06 10:25:17 mdw
33 * Support Linux TUN/TAP device. Fix some bugs.
34 *
35 */
36
37/*----- Header files ------------------------------------------------------*/
38
39#include "tripe.h"
40
41#include <sys/ioctl.h>
42
43/*----- Main code ---------------------------------------------------------*/
44
45#if TUN_TYPE != TUN_LINUX
46# error "Tunnel type mismatch: fix the Makefile"
47#endif
48
49/* --- @t_read@ --- *
50 *
51 * Arguments: @int fd@ = file descriptor to read
52 * @unsigned mode@ = what's happened
53 * @void *v@ = pointer to tunnel block
54 *
55 * Returns: ---
56 *
57 * Use: Reads data from the tunnel.
58 */
59
60static void t_read(int fd, unsigned mode, void *v)
61{
62 tunnel *t = v;
63 ssize_t n;
64 buf b;
65
66 n = read(fd, buf_i, sizeof(buf_i));
67 if (n < 0) {
68 a_warn("tunnel read failed (%s): %s", t->ifn, strerror(errno));
69 return;
70 }
71 IF_TRACING(T_TUNNEL, {
72 trace(T_TUNNEL, "tunnel: packet arrived");
73 trace_block(T_PACKET, "tunnel: packet contents", buf_i, n);
74 })
75 buf_init(&b, buf_i, n);
76 p_tun(t->p, &b);
77}
78
79/* --- @tun_init@ --- *
80 *
81 * Arguments: ---
82 *
83 * Returns: ---
84 *
85 * Use: Initializes the tunneling system. Maybe this will require
86 * opening file descriptors or something.
87 */
88
89void tun_init(void)
90{
91 return;
92}
93
94/* --- @tun_create@ --- *
95 *
96 * Arguments: @tunnel *t@ = pointer to tunnel block
97 * @peer *p@ = pointer to peer block
98 *
99 * Returns: Zero if it worked, nonzero on failure.
100 *
101 * Use: Initializes a new tunnel.
102 */
103
104int tun_create(tunnel *t, peer *p)
105{
106 int fd;
107 int f;
108 struct ifreq iff;
109
110 if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
111 a_warn("open `/dev/net/tun' failed: %s", strerror(errno));
112 return (-1);
113 }
114 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
115 iff.ifr_name[0] = 0;
116 iff.ifr_flags = IFF_TUN | IFF_NO_PI;
117 if ((f = ioctl(fd, TUNSETIFF, &iff)) < 0) {
118 a_warn("couldn't set configure new TUN/TAP interface: %s",
119 strerror(errno));
120 close(fd);
121 return (-1);
122 }
123 t->p = p;
124 sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
125 sel_addfile(&t->f);
126 iff.ifr_name[IFNAMSIZ - 1] = 0;
127 strcpy(t->ifn, iff.ifr_name);
128 T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'",
129 t->ifn, p_name(p)); )
130 return (0);
131}
132
133/* --- @tun_ifname@ --- *
134 *
135 * Arguments: @tunnel *t@ = pointer to tunnel block
136 *
137 * Returns: A pointer to the tunnel's interface name.
138 */
139
140const char *tun_ifname(tunnel *t)
141{
142 return (t->ifn);
143}
144
145/* --- @tun_inject@ --- *
146 *
147 * Arguments: @tunnel *t@ = pointer to tunnel block
148 * @buf *b@ = buffer to send
149 *
150 * Returns: ---
151 *
152 * Use: Injects a packet into the local network stack.
153 */
154
155void tun_inject(tunnel *t, buf *b)
156{
157 IF_TRACING(T_TUNNEL, {
158 trace(T_TUNNEL, "tunnel: inject decrypted packet");
159 trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
160 })
161 write(t->f.fd, BBASE(b), BLEN(b));
162}
163
164/* --- @tun_destroy@ --- *
165 *
166 * Arguments: @tunnel *t@ = pointer to tunnel block
167 *
168 * Returns: ---
169 *
170 * Use: Destroys a tunnel.
171 */
172
173void tun_destroy(tunnel *t)
174{
175 sel_rmfile(&t->f);
176 close(t->f.fd);
177}
178
179/*----- That's all, folks -------------------------------------------------*/