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1 | /* -*-c-*- |
2 | * |
3 | * $Id: tun-bsd.c,v 1.1 2001/02/05 19:48:18 mdw Exp $ |
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 | |
29 | /*----- Revision history --------------------------------------------------* |
30 | * |
31 | * $Log: tun-bsd.c,v $ |
32 | * Revision 1.1 2001/02/05 19:48:18 mdw |
33 | * Initial support for BSD tunnel devices. |
34 | * |
35 | */ |
36 | |
37 | /*----- Header files ------------------------------------------------------*/ |
38 | |
39 | #include "tripe.h" |
40 | |
41 | /*----- Main code ---------------------------------------------------------*/ |
42 | |
43 | #if TUN_TYPE != TUN_BSD |
44 | # error "Tunnel type mismatch: fix the Makefile" |
45 | #endif |
46 | |
47 | /* --- @t_read@ --- * |
48 | * |
49 | * Arguments: @int fd@ = file descriptor to read |
50 | * @unsigned mode@ = what's happened |
51 | * @void *v@ = pointer to tunnel block |
52 | * |
53 | * Returns: --- |
54 | * |
55 | * Use: Reads data from the tunnel. |
56 | */ |
57 | |
58 | void t_read(int fd, unsigned mode, void *v) |
59 | { |
60 | tunnel *t = v; |
61 | ssize_t n; |
62 | buf b; |
63 | |
64 | n = read(fd, buf_i, sizeof(buf_i)); |
65 | if (n < 0) { |
66 | a_warn("tunnel read failed (%s): %s", tun_ifname(t), strerror(errno)); |
67 | return; |
68 | } |
69 | IF_TRACING(T_TUNNEL, { |
70 | trace(T_TUNNEL, "tunnel: packet arrived"); |
71 | trace_block(T_PACKET, "tunnel: packet contents", buf_i, n); |
72 | }) |
73 | buf_init(&b, buf_i, n); |
74 | p_tun(t->p, &b); |
75 | } |
76 | |
77 | /* --- @tun_init@ --- * |
78 | * |
79 | * Arguments: --- |
80 | * |
81 | * Returns: --- |
82 | * |
83 | * Use: Initializes the tunneling system. Maybe this will require |
84 | * opening file descriptors or something. |
85 | */ |
86 | |
87 | void tun_init(void) |
88 | { |
89 | return; |
90 | } |
91 | |
92 | /* --- @tun_create@ --- * |
93 | * |
94 | * Arguments: @tunnel *t@ = pointer to tunnel block |
95 | * @peer *p@ = pointer to peer block |
96 | * |
97 | * Returns: Zero if it worked, nonzero on failure. |
98 | * |
99 | * Use: Initializes a new tunnel. |
100 | */ |
101 | |
102 | int tun_create(tunnel *t, peer *p) |
103 | { |
104 | int fd; |
105 | unsigned n; |
106 | char buf[16]; |
107 | |
108 | n = 0; |
109 | for (;;) { |
110 | sprintf(buf, "/dev/tun%u", n); |
111 | if ((fd = open("/dev/unet", O_RDWR)) >= 0) |
112 | break; |
113 | switch (errno) { |
114 | case EBUSY: |
115 | T( trace(T_TUNNEL, "tunnel device %u busy: skipping", n); ) |
116 | break; |
117 | case ENOENT: |
118 | a_warn("no suitable tunnel devices found"); |
119 | return (-1); |
120 | default: |
121 | a_warn("error opening `%s': %s (skipping)", buf, strerror(errno)); |
122 | break; |
123 | } |
124 | n++; |
125 | } |
126 | |
127 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
128 | t->p = p; |
129 | t->n = n; |
130 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
131 | sel_addfile(&t->f); |
132 | T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'", |
133 | tun_ifname(t), p_name(p)); ) |
134 | return (0); |
135 | } |
136 | |
137 | /* --- @tun_ifname@ --- * |
138 | * |
139 | * Arguments: @tunnel *t@ = pointer to tunnel block |
140 | * |
141 | * Returns: A pointer to the tunnel's interface name. |
142 | */ |
143 | |
144 | const char *tun_ifname(tunnel *t) |
145 | { |
146 | static char buf[8]; |
147 | sprintf(buf, "tun%u", t->n); |
148 | return (buf); |
149 | } |
150 | |
151 | /* --- @tun_inject@ --- * |
152 | * |
153 | * Arguments: @tunnel *t@ = pointer to tunnel block |
154 | * @buf *b@ = buffer to send |
155 | * |
156 | * Returns: --- |
157 | * |
158 | * Use: Injects a packet into the local network stack. |
159 | */ |
160 | |
161 | void tun_inject(tunnel *t, buf *b) |
162 | { |
163 | IF_TRACING(T_TUNNEL, { |
164 | trace(T_TUNNEL, "tunnel: inject decrypted packet"); |
165 | trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b)); |
166 | }) |
167 | write(t->f.fd, BBASE(b), BLEN(b)); |
168 | } |
169 | |
170 | /* --- @tun_destroy@ --- * |
171 | * |
172 | * Arguments: @tunnel *t@ = pointer to tunnel block |
173 | * |
174 | * Returns: --- |
175 | * |
176 | * Use: Destroys a tunnel. |
177 | */ |
178 | |
179 | void tun_destroy(tunnel *t) |
180 | { |
181 | sel_rmfile(&t->f); |
182 | close(t->f.fd); |
183 | } |
184 | |
185 | /*----- That's all, folks -------------------------------------------------*/ |