fd528bde |
1 | /* -*-c-*- |
fd528bde |
2 | * |
3 | * Tunnel interface for 4.4BSD-derived systems |
4 | * |
5 | * (c) 2001 Straylight/Edgeware |
6 | */ |
7 | |
e04c2d50 |
8 | /*----- Licensing notice --------------------------------------------------* |
fd528bde |
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 | * |
fd528bde |
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 | * |
fd528bde |
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 | |
fd528bde |
27 | /*----- Header files ------------------------------------------------------*/ |
28 | |
42da2a58 |
29 | #define TUN_INTERNALS |
30 | |
fd528bde |
31 | #include "tripe.h" |
32 | |
33 | /*----- Main code ---------------------------------------------------------*/ |
34 | |
42da2a58 |
35 | #ifdef TUN_BSD |
36 | |
37 | struct tunnel { |
38 | const tunnel_ops *ops; /* Pointer to operations */ |
39 | sel_file f; /* Selector for tunnel device */ |
40 | struct peer *p; /* Pointer to my peer */ |
41 | unsigned n; /* Number of my tunnel device */ |
e04c2d50 |
42 | }; |
42da2a58 |
43 | |
fd528bde |
44 | /* --- @t_read@ --- * |
45 | * |
46 | * Arguments: @int fd@ = file descriptor to read |
47 | * @unsigned mode@ = what's happened |
48 | * @void *v@ = pointer to tunnel block |
49 | * |
50 | * Returns: --- |
51 | * |
52 | * Use: Reads data from the tunnel. |
53 | */ |
54 | |
42da2a58 |
55 | static void t_read(int fd, unsigned mode, void *v) |
fd528bde |
56 | { |
57 | tunnel *t = v; |
58 | ssize_t n; |
59 | buf b; |
60 | |
61 | n = read(fd, buf_i, sizeof(buf_i)); |
62 | if (n < 0) { |
72917fe7 |
63 | a_warn("TUN", "%s", p_ifname(t->p), "read-error", "?ERRNO", A_END); |
fd528bde |
64 | return; |
65 | } |
66 | IF_TRACING(T_TUNNEL, { |
060ca767 |
67 | trace(T_TUNNEL, "tun-bsd: packet arrived"); |
68 | trace_block(T_PACKET, "tun-bsd: packet contents", buf_i, n); |
fd528bde |
69 | }) |
70 | buf_init(&b, buf_i, n); |
71 | p_tun(t->p, &b); |
72 | } |
73 | |
42da2a58 |
74 | /* --- @t_init@ --- * |
fd528bde |
75 | * |
76 | * Arguments: --- |
77 | * |
78 | * Returns: --- |
79 | * |
80 | * Use: Initializes the tunneling system. Maybe this will require |
81 | * opening file descriptors or something. |
82 | */ |
83 | |
42da2a58 |
84 | static void t_init(void) { return; } |
fd528bde |
85 | |
42da2a58 |
86 | /* --- @t_create@ --- * |
fd528bde |
87 | * |
42da2a58 |
88 | * Arguments: @peer *p@ = pointer to peer block |
72917fe7 |
89 | * @char **ifn@ = where to put the interface name |
fd528bde |
90 | * |
42da2a58 |
91 | * Returns: A tunnel block if it worked, or null on failure. |
fd528bde |
92 | * |
93 | * Use: Initializes a new tunnel. |
94 | */ |
95 | |
72917fe7 |
96 | static tunnel *t_create(peer *p, char **ifn) |
fd528bde |
97 | { |
98 | int fd; |
99 | unsigned n; |
42da2a58 |
100 | tunnel *t; |
fd528bde |
101 | char buf[16]; |
102 | |
103 | n = 0; |
104 | for (;;) { |
105 | sprintf(buf, "/dev/tun%u", n); |
ef4a1ab7 |
106 | if ((fd = open(buf, O_RDWR)) >= 0) |
fd528bde |
107 | break; |
108 | switch (errno) { |
109 | case EBUSY: |
110 | T( trace(T_TUNNEL, "tunnel device %u busy: skipping", n); ) |
111 | break; |
112 | case ENOENT: |
f43df819 |
113 | a_warn("TUN", "-", "bsd", "no-tunnel-devices", A_END); |
42da2a58 |
114 | return (0); |
fd528bde |
115 | default: |
f43df819 |
116 | a_warn("TUN", "-", "open-error", "%s", buf, "?ERRNO", A_END); |
fd528bde |
117 | break; |
118 | } |
119 | n++; |
120 | } |
121 | |
42da2a58 |
122 | t = CREATE(tunnel); |
123 | t->ops = &tun_bsd; |
fd528bde |
124 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
125 | t->p = p; |
126 | t->n = n; |
127 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
128 | sel_addfile(&t->f); |
72917fe7 |
129 | *ifn = xstrdup(buf + 5); |
060ca767 |
130 | T( trace(T_TUNNEL, "tun-bsd: attached interface %s to peer `%s'", |
72917fe7 |
131 | *ifn, p_name(p)); ) |
42da2a58 |
132 | return (t); |
fd528bde |
133 | } |
134 | |
42da2a58 |
135 | /* --- @t_inject@ --- * |
fd528bde |
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 |
145 | static void t_inject(tunnel *t, buf *b) |
fd528bde |
146 | { |
147 | IF_TRACING(T_TUNNEL, { |
060ca767 |
148 | trace(T_TUNNEL, "tun-bsd: inject decrypted packet"); |
149 | trace_block(T_PACKET, "tun-bsd: packet contents", BBASE(b), BLEN(b)); |
fd528bde |
150 | }) |
151 | write(t->f.fd, BBASE(b), BLEN(b)); |
152 | } |
153 | |
42da2a58 |
154 | /* --- @t_destroy@ --- * |
fd528bde |
155 | * |
156 | * Arguments: @tunnel *t@ = pointer to tunnel block |
157 | * |
158 | * Returns: --- |
159 | * |
160 | * Use: Destroys a tunnel. |
161 | */ |
162 | |
42da2a58 |
163 | static void t_destroy(tunnel *t) |
6047fbac |
164 | { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); } |
fd528bde |
165 | |
42da2a58 |
166 | const tunnel_ops tun_bsd = { |
167 | "bsd", |
168 | t_init, |
169 | t_create, |
72917fe7 |
170 | 0, |
42da2a58 |
171 | t_inject, |
172 | t_destroy |
173 | }; |
174 | |
175 | #endif |
176 | |
fd528bde |
177 | /*----- That's all, folks -------------------------------------------------*/ |