3 * $Id: tun-unet.c,v 1.6 2004/04/08 01:36:17 mdw Exp $
5 * Tunnel interface based on Linux Usernet
7 * (c) 2001 Straylight/Edgeware
10 /*----- Licensing notice --------------------------------------------------*
12 * This file is part of Trivial IP Encryption (TrIPE).
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.
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.
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.
29 /*----- Header files ------------------------------------------------------*/
33 #include <sys/ioctl.h>
37 /*----- Main code ---------------------------------------------------------*/
39 #if TUN_TYPE != TUN_UNET
40 # error "Tunnel type mismatch: fix the Makefile"
45 * Arguments: @int fd@ = file descriptor to read
46 * @unsigned mode@ = what's happened
47 * @void *v@ = pointer to tunnel block
51 * Use: Reads data from the tunnel.
54 static void t_read(int fd, unsigned mode, void *v)
60 n = read(fd, buf_i, sizeof(buf_i));
62 a_warn("tunnel read failed (%s): %s", tun_ifname(t), strerror(errno));
65 IF_TRACING(T_TUNNEL, {
66 trace(T_TUNNEL, "tunnel: packet arrived");
67 trace_block(T_PACKET, "tunnel: packet contents", buf_i, n);
69 buf_init(&b, buf_i, n);
73 /* --- @tun_init@ --- *
79 * Use: Initializes the tunneling system. Maybe this will require
80 * opening file descriptors or something.
88 /* --- @tun_create@ --- *
90 * Arguments: @tunnel *t@ = pointer to tunnel block
91 * @peer *p@ = pointer to peer block
93 * Returns: Zero if it worked, nonzero on failure.
95 * Use: Initializes a new tunnel.
98 int tun_create(tunnel *t, peer *p)
103 if ((fd = open("/dev/unet", O_RDWR)) < 0) {
104 a_warn("open `/dev/unet' failed: %s", strerror(errno));
107 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
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));
115 sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
117 T( trace(T_TUNNEL, "tunnel: attached interface %s to peer `%s'",
118 tun_ifname(t), p_name(p)); )
122 /* --- @tun_ifname@ --- *
124 * Arguments: @tunnel *t@ = pointer to tunnel block
126 * Returns: A pointer to the tunnel's interface name.
129 const char *tun_ifname(tunnel *t)
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));
137 if (strlen(uni.uni_ifname) + 1 > sizeof(b)) {
138 a_warn("interface name too long!");
141 strcpy(b, uni.uni_ifname);
145 /* --- @tun_inject@ --- *
147 * Arguments: @tunnel *t@ = pointer to tunnel block
148 * @buf *b@ = buffer to send
152 * Use: Injects a packet into the local network stack.
155 void tun_inject(tunnel *t, buf *b)
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));
161 write(t->f.fd, BBASE(b), BLEN(b));
164 /* --- @tun_destroy@ --- *
166 * Arguments: @tunnel *t@ = pointer to tunnel block
170 * Use: Destroys a tunnel.
173 void tun_destroy(tunnel *t)
179 /*----- That's all, folks -------------------------------------------------*/