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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tun-unet.c,v 1.3 2001/02/05 19:55:00 mdw Exp $ |
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4 | * |
5 | * Tunnel interface based on Linux Usernet |
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-unet.c,v $ |
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32 | * Revision 1.3 2001/02/05 19:55:00 mdw |
33 | * Guard against inappropriate compilation. |
34 | * |
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35 | * Revision 1.2 2001/02/04 17:10:58 mdw |
36 | * Make file descriptors be nonblocking and close-on-exec. |
37 | * |
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38 | * Revision 1.1 2001/02/03 20:26:37 mdw |
39 | * Initial checkin. |
40 | * |
41 | */ |
42 | |
43 | /*----- Header files ------------------------------------------------------*/ |
44 | |
45 | #include "tripe.h" |
46 | |
47 | #include <sys/ioctl.h> |
48 | #include <unet.h> |
49 | |
50 | /*----- Main code ---------------------------------------------------------*/ |
51 | |
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52 | #if TUN_TYPE != TUN_UNET |
53 | # error "Tunnel type mismatch: fix the Makefile" |
54 | #endif |
55 | |
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56 | /* --- @t_read@ --- * |
57 | * |
58 | * Arguments: @int fd@ = file descriptor to read |
59 | * @unsigned mode@ = what's happened |
60 | * @void *v@ = pointer to tunnel block |
61 | * |
62 | * Returns: --- |
63 | * |
64 | * Use: Reads data from the tunnel. |
65 | */ |
66 | |
67 | void t_read(int fd, unsigned mode, void *v) |
68 | { |
69 | tunnel *t = v; |
70 | ssize_t n; |
71 | buf b; |
72 | |
73 | n = read(fd, buf_i, sizeof(buf_i)); |
74 | if (n < 0) { |
75 | a_warn("tunnel read failed (%s): %s", tun_ifname(t), strerror(errno)); |
76 | return; |
77 | } |
78 | IF_TRACING(T_TUNNEL, { |
79 | trace(T_TUNNEL, "tunnel: packet arrived"); |
80 | trace_block(T_PACKET, "tunnel: packet contents", buf_i, n); |
81 | }) |
82 | buf_init(&b, buf_i, n); |
83 | p_tun(t->p, &b); |
84 | } |
85 | |
86 | /* --- @tun_init@ --- * |
87 | * |
88 | * Arguments: --- |
89 | * |
90 | * Returns: --- |
91 | * |
92 | * Use: Initializes the tunneling system. Maybe this will require |
93 | * opening file descriptors or something. |
94 | */ |
95 | |
96 | void tun_init(void) |
97 | { |
98 | return; |
99 | } |
100 | |
101 | /* --- @tun_create@ --- * |
102 | * |
103 | * Arguments: @tunnel *t@ = pointer to tunnel block |
104 | * @peer *p@ = pointer to peer block |
105 | * |
106 | * Returns: Zero if it worked, nonzero on failure. |
107 | * |
108 | * Use: Initializes a new tunnel. |
109 | */ |
110 | |
111 | int tun_create(tunnel *t, peer *p) |
112 | { |
113 | int fd; |
114 | |
115 | if ((fd = open("/dev/unet", O_RDWR)) < 0) { |
116 | a_warn("open `/dev/unet' failed: %s", strerror(errno)); |
117 | return (-1); |
118 | } |
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119 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
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120 | t->p = p; |
121 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
122 | sel_addfile(&t->f); |
123 | T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'", |
124 | tun_ifname(t), p_name(p)); ) |
125 | return (0); |
126 | } |
127 | |
128 | /* --- @tun_ifname@ --- * |
129 | * |
130 | * Arguments: @tunnel *t@ = pointer to tunnel block |
131 | * |
132 | * Returns: A pointer to the tunnel's interface name. |
133 | */ |
134 | |
135 | const char *tun_ifname(tunnel *t) |
136 | { |
137 | static char b[UNET_NAMEMAX]; |
138 | struct unet_info uni; |
139 | if (ioctl(t->f.fd, UNIOCGINFO, &uni)) { |
140 | a_warn("ioctl(UNIOCGINFO) failed: %s", strerror(errno)); |
141 | return ("<error>"); |
142 | } |
143 | if (strlen(uni.uni_ifname) + 1 > sizeof(b)) { |
144 | a_warn("interface name too long!"); |
145 | return ("<error>"); |
146 | } |
147 | strcpy(b, uni.uni_ifname); |
148 | return (b); |
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 -------------------------------------------------*/ |