chiark / gitweb /
server/keyset.c, server/keymgmt.c: Variable data limits.
[tripe] / server / tun-linux.c
CommitLineData
37075862 1/* -*-c-*-
2 *
37075862 3 * Tunnel interface based on Linux TUN/TAP driver
4 *
5 * (c) 2003 Straylight/Edgeware
6 */
7
e04c2d50 8/*----- Licensing notice --------------------------------------------------*
37075862 9 *
10 * This file is part of Trivial IP Encryption (TrIPE).
11 *
12 * TrIPE is free software; you can redistribute it and/or modify
13 * it under the terms of the GNU General Public License as published by
14 * the Free Software Foundation; either version 2 of the License, or
15 * (at your option) any later version.
e04c2d50 16 *
37075862 17 * TrIPE is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 * GNU General Public License for more details.
e04c2d50 21 *
37075862 22 * You should have received a copy of the GNU General Public License
23 * along with TrIPE; if not, write to the Free Software Foundation,
24 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
25 */
26
37075862 27/*----- Header files ------------------------------------------------------*/
28
42da2a58 29#define TUN_INTERNALS
30
37075862 31#include "tripe.h"
32
42da2a58 33#ifdef TUN_LINUX
34# include <sys/ioctl.h>
35# include <linux/if.h>
36# include <linux/if_tun.h>
37#endif
37075862 38
39/*----- Main code ---------------------------------------------------------*/
40
42da2a58 41#ifdef TUN_LINUX
42
43struct tunnel {
44 const tunnel_ops *ops; /* Pointer to operations */
45 sel_file f; /* Selector for TUN/TAP device */
46 struct peer *p; /* Pointer to my peer */
e04c2d50 47};
37075862 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) {
72917fe7 68 a_warn("TUN", "%s", p_ifname(t->p), "read-error", "?ERRNO", A_END);
37075862 69 return;
70 }
71 IF_TRACING(T_TUNNEL, {
060ca767 72 trace(T_TUNNEL, "tun-linux: packet arrived");
73 trace_block(T_PACKET, "tun-linux: packet contents", buf_i, n);
37075862 74 })
75 buf_init(&b, buf_i, n);
76 p_tun(t->p, &b);
77}
78
42da2a58 79/* --- @t_init@ --- *
37075862 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
42da2a58 89static void t_init(void) { return; }
37075862 90
42da2a58 91/* --- @t_create@ --- *
37075862 92 *
42da2a58 93 * Arguments: @peer *p@ = pointer to peer block
72917fe7 94 * @char **ifn@ = where to put the interface name
37075862 95 *
42da2a58 96 * Returns: A tunnel block if it worked, or null on failure.
37075862 97 *
98 * Use: Initializes a new tunnel.
99 */
100
72917fe7 101static tunnel *t_create(peer *p, char **ifn)
37075862 102{
103 int fd;
104 int f;
105 struct ifreq iff;
42da2a58 106 tunnel *t;
37075862 107
108 if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
f43df819
MW
109 a_warn("TUN", "-", "linux",
110 "open-error", "/dev/net/tun", "?ERRNO",
111 A_END);
42da2a58 112 return (0);
37075862 113 }
114 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
060ca767 115 memset(&iff, 0, sizeof(iff));
37075862 116 iff.ifr_name[0] = 0;
b9066fbb 117 iff.ifr_flags = IFF_TUN | IFF_NO_PI;
37075862 118 if ((f = ioctl(fd, TUNSETIFF, &iff)) < 0) {
f43df819 119 a_warn("TUN", "-", "linux", "config-error", "?ERRNO", A_END);
37075862 120 close(fd);
42da2a58 121 return (0);
37075862 122 }
42da2a58 123 t = CREATE(tunnel);
124 t->ops = &tun_linux;
37075862 125 t->p = p;
126 sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
127 sel_addfile(&t->f);
128 iff.ifr_name[IFNAMSIZ - 1] = 0;
72917fe7 129 *ifn = xstrdup(iff.ifr_name);
060ca767 130 T( trace(T_TUNNEL, "tun-linux: attached interface %s to peer `%s'",
72917fe7 131 *ifn, p_name(p)); )
42da2a58 132 return (t);
37075862 133}
134
42da2a58 135/* --- @t_inject@ --- *
37075862 136 *
137 * Arguments: @tunnel *t@ = pointer to tunnel block
138 * @buf *b@ = buffer to send
139 *
140 * Returns: ---
141 *
142 * Use: Injects a packet into the local network stack.
143 */
144
42da2a58 145static void t_inject(tunnel *t, buf *b)
37075862 146{
147 IF_TRACING(T_TUNNEL, {
060ca767 148 trace(T_TUNNEL, "tun-linux: inject decrypted packet");
37075862 149 trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
150 })
151 write(t->f.fd, BBASE(b), BLEN(b));
152}
153
42da2a58 154/* --- @t_destroy@ --- *
37075862 155 *
156 * Arguments: @tunnel *t@ = pointer to tunnel block
157 *
158 * Returns: ---
159 *
160 * Use: Destroys a tunnel.
161 */
162
42da2a58 163static void t_destroy(tunnel *t)
6047fbac 164 { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); }
37075862 165
42da2a58 166const tunnel_ops tun_linux = {
167 "linux",
168 t_init,
169 t_create,
72917fe7 170 0,
42da2a58 171 t_inject,
172 t_destroy
173};
174
175#endif
176
37075862 177/*----- That's all, folks -------------------------------------------------*/