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Allow admin clients to filter out async messages. Send notifications
[tripe] / tun-bsd.c
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fd528bde 1/* -*-c-*-
2 *
3cdc3f3a 3 * $Id$
fd528bde 4 *
5 * Tunnel interface for 4.4BSD-derived systems
6 *
7 * (c) 2001 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
fd528bde 29/*----- Header files ------------------------------------------------------*/
30
31#include "tripe.h"
32
33/*----- Main code ---------------------------------------------------------*/
34
35#if TUN_TYPE != TUN_BSD
36# error "Tunnel type mismatch: fix the Makefile"
37#endif
38
39/* --- @t_read@ --- *
40 *
41 * Arguments: @int fd@ = file descriptor to read
42 * @unsigned mode@ = what's happened
43 * @void *v@ = pointer to tunnel block
44 *
45 * Returns: ---
46 *
47 * Use: Reads data from the tunnel.
48 */
49
50void t_read(int fd, unsigned mode, void *v)
51{
52 tunnel *t = v;
53 ssize_t n;
54 buf b;
55
56 n = read(fd, buf_i, sizeof(buf_i));
57 if (n < 0) {
3cdc3f3a 58 a_warn("TUN %s read-error -- %s", tun_ifname(t), strerror(errno));
fd528bde 59 return;
60 }
61 IF_TRACING(T_TUNNEL, {
62 trace(T_TUNNEL, "tunnel: packet arrived");
63 trace_block(T_PACKET, "tunnel: packet contents", buf_i, n);
64 })
65 buf_init(&b, buf_i, n);
66 p_tun(t->p, &b);
67}
68
69/* --- @tun_init@ --- *
70 *
71 * Arguments: ---
72 *
73 * Returns: ---
74 *
75 * Use: Initializes the tunneling system. Maybe this will require
76 * opening file descriptors or something.
77 */
78
79void tun_init(void)
80{
81 return;
82}
83
84/* --- @tun_create@ --- *
85 *
86 * Arguments: @tunnel *t@ = pointer to tunnel block
87 * @peer *p@ = pointer to peer block
88 *
89 * Returns: Zero if it worked, nonzero on failure.
90 *
91 * Use: Initializes a new tunnel.
92 */
93
94int tun_create(tunnel *t, peer *p)
95{
96 int fd;
97 unsigned n;
98 char buf[16];
99
100 n = 0;
101 for (;;) {
102 sprintf(buf, "/dev/tun%u", n);
ef4a1ab7 103 if ((fd = open(buf, O_RDWR)) >= 0)
fd528bde 104 break;
105 switch (errno) {
106 case EBUSY:
107 T( trace(T_TUNNEL, "tunnel device %u busy: skipping", n); )
108 break;
109 case ENOENT:
3cdc3f3a 110 a_warn("TUN - bsd no-tunnel-devices");
fd528bde 111 return (-1);
112 default:
3cdc3f3a 113 a_warn("TUN - open-error %s -- %s", buf, strerror(errno));
fd528bde 114 break;
115 }
116 n++;
117 }
118
119 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
120 t->p = p;
121 t->n = n;
122 sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
123 sel_addfile(&t->f);
124 T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'",
125 tun_ifname(t), p_name(p)); )
126 return (0);
127}
128
129/* --- @tun_ifname@ --- *
130 *
131 * Arguments: @tunnel *t@ = pointer to tunnel block
132 *
133 * Returns: A pointer to the tunnel's interface name.
134 */
135
136const char *tun_ifname(tunnel *t)
137{
138 static char buf[8];
139 sprintf(buf, "tun%u", t->n);
140 return (buf);
141}
142
143/* --- @tun_inject@ --- *
144 *
145 * Arguments: @tunnel *t@ = pointer to tunnel block
146 * @buf *b@ = buffer to send
147 *
148 * Returns: ---
149 *
150 * Use: Injects a packet into the local network stack.
151 */
152
153void tun_inject(tunnel *t, buf *b)
154{
155 IF_TRACING(T_TUNNEL, {
156 trace(T_TUNNEL, "tunnel: inject decrypted packet");
157 trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
158 })
159 write(t->f.fd, BBASE(b), BLEN(b));
160}
161
162/* --- @tun_destroy@ --- *
163 *
164 * Arguments: @tunnel *t@ = pointer to tunnel block
165 *
166 * Returns: ---
167 *
168 * Use: Destroys a tunnel.
169 */
170
171void tun_destroy(tunnel *t)
172{
173 sel_rmfile(&t->f);
174 close(t->f.fd);
175}
176
177/*----- That's all, folks -------------------------------------------------*/