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1 | /* -*-c-*- |
2 | * |
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3 | * $Id: tun-unet.c,v 1.6 2004/04/08 01:36:17 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 | |
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29 | /*----- Header files ------------------------------------------------------*/ |
30 | |
31 | #include "tripe.h" |
32 | |
33 | #include <sys/ioctl.h> |
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34 | #include <net/if.h> |
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35 | #include <unet.h> |
36 | |
37 | /*----- Main code ---------------------------------------------------------*/ |
38 | |
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39 | #if TUN_TYPE != TUN_UNET |
40 | # error "Tunnel type mismatch: fix the Makefile" |
41 | #endif |
42 | |
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43 | /* --- @t_read@ --- * |
44 | * |
45 | * Arguments: @int fd@ = file descriptor to read |
46 | * @unsigned mode@ = what's happened |
47 | * @void *v@ = pointer to tunnel block |
48 | * |
49 | * Returns: --- |
50 | * |
51 | * Use: Reads data from the tunnel. |
52 | */ |
53 | |
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54 | static void t_read(int fd, unsigned mode, void *v) |
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55 | { |
56 | tunnel *t = v; |
57 | ssize_t n; |
58 | buf b; |
59 | |
60 | n = read(fd, buf_i, sizeof(buf_i)); |
61 | if (n < 0) { |
62 | a_warn("tunnel read failed (%s): %s", tun_ifname(t), strerror(errno)); |
63 | return; |
64 | } |
65 | IF_TRACING(T_TUNNEL, { |
66 | trace(T_TUNNEL, "tunnel: packet arrived"); |
67 | trace_block(T_PACKET, "tunnel: packet contents", buf_i, n); |
68 | }) |
69 | buf_init(&b, buf_i, n); |
70 | p_tun(t->p, &b); |
71 | } |
72 | |
73 | /* --- @tun_init@ --- * |
74 | * |
75 | * Arguments: --- |
76 | * |
77 | * Returns: --- |
78 | * |
79 | * Use: Initializes the tunneling system. Maybe this will require |
80 | * opening file descriptors or something. |
81 | */ |
82 | |
83 | void tun_init(void) |
84 | { |
85 | return; |
86 | } |
87 | |
88 | /* --- @tun_create@ --- * |
89 | * |
90 | * Arguments: @tunnel *t@ = pointer to tunnel block |
91 | * @peer *p@ = pointer to peer block |
92 | * |
93 | * Returns: Zero if it worked, nonzero on failure. |
94 | * |
95 | * Use: Initializes a new tunnel. |
96 | */ |
97 | |
98 | int tun_create(tunnel *t, peer *p) |
99 | { |
100 | int fd; |
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101 | int f; |
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102 | |
103 | if ((fd = open("/dev/unet", O_RDWR)) < 0) { |
104 | a_warn("open `/dev/unet' failed: %s", strerror(errno)); |
105 | return (-1); |
106 | } |
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107 | fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC); |
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108 | if ((f = ioctl(fd, UNIOCGIFFLAGS)) < 0 || |
109 | ioctl(fd, UNIOCSIFFLAGS, f | IFF_POINTOPOINT)) { |
110 | a_warn("couldn't set point-to-point flag: %s", strerror(errno)); |
111 | close(fd); |
112 | return (-1); |
113 | } |
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114 | t->p = p; |
115 | sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t); |
116 | sel_addfile(&t->f); |
117 | T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'", |
118 | tun_ifname(t), p_name(p)); ) |
119 | return (0); |
120 | } |
121 | |
122 | /* --- @tun_ifname@ --- * |
123 | * |
124 | * Arguments: @tunnel *t@ = pointer to tunnel block |
125 | * |
126 | * Returns: A pointer to the tunnel's interface name. |
127 | */ |
128 | |
129 | const char *tun_ifname(tunnel *t) |
130 | { |
131 | static char b[UNET_NAMEMAX]; |
132 | struct unet_info uni; |
133 | if (ioctl(t->f.fd, UNIOCGINFO, &uni)) { |
134 | a_warn("ioctl(UNIOCGINFO) failed: %s", strerror(errno)); |
135 | return ("<error>"); |
136 | } |
137 | if (strlen(uni.uni_ifname) + 1 > sizeof(b)) { |
138 | a_warn("interface name too long!"); |
139 | return ("<error>"); |
140 | } |
141 | strcpy(b, uni.uni_ifname); |
142 | return (b); |
143 | } |
144 | |
145 | /* --- @tun_inject@ --- * |
146 | * |
147 | * Arguments: @tunnel *t@ = pointer to tunnel block |
148 | * @buf *b@ = buffer to send |
149 | * |
150 | * Returns: --- |
151 | * |
152 | * Use: Injects a packet into the local network stack. |
153 | */ |
154 | |
155 | void tun_inject(tunnel *t, buf *b) |
156 | { |
157 | IF_TRACING(T_TUNNEL, { |
158 | trace(T_TUNNEL, "tunnel: inject decrypted packet"); |
159 | trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b)); |
160 | }) |
161 | write(t->f.fd, BBASE(b), BLEN(b)); |
162 | } |
163 | |
164 | /* --- @tun_destroy@ --- * |
165 | * |
166 | * Arguments: @tunnel *t@ = pointer to tunnel block |
167 | * |
168 | * Returns: --- |
169 | * |
170 | * Use: Destroys a tunnel. |
171 | */ |
172 | |
173 | void tun_destroy(tunnel *t) |
174 | { |
175 | sel_rmfile(&t->f); |
176 | close(t->f.fd); |
177 | } |
178 | |
179 | /*----- That's all, folks -------------------------------------------------*/ |