3 * Tunnel interface based on Linux TUN/TAP driver
5 * (c) 2003 Straylight/Edgeware
8 /*----- Licensing notice --------------------------------------------------*
10 * This file is part of Trivial IP Encryption (TrIPE).
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.
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.
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.
27 /*----- Header files ------------------------------------------------------*/
34 # include <sys/ioctl.h>
35 # include <linux/if.h>
36 # include <linux/if_tun.h>
39 /*----- Main code ---------------------------------------------------------*/
44 const tunnel_ops *ops; /* Pointer to operations */
45 sel_file f; /* Selector for TUN/TAP device */
46 struct peer *p; /* Pointer to my peer */
51 * Arguments: @int fd@ = file descriptor to read
52 * @unsigned mode@ = what's happened
53 * @void *v@ = pointer to tunnel block
57 * Use: Reads data from the tunnel.
60 static void t_read(int fd, unsigned mode, void *v)
66 n = read(fd, buf_i, sizeof(buf_i));
68 a_warn("TUN", "%s", p_ifname(t->p), "read-error", "?ERRNO", A_END);
71 IF_TRACING(T_TUNNEL, {
72 trace(T_TUNNEL, "tun-linux: packet arrived");
73 trace_block(T_PACKET, "tun-linux: packet contents", buf_i, n);
75 buf_init(&b, buf_i, n);
85 * Use: Initializes the tunneling system. Maybe this will require
86 * opening file descriptors or something.
89 static void t_init(void) { return; }
93 * Arguments: @char **ifn@ = where to put the interface name
95 * Returns: A file descriptor, or @-1@ on failure.
97 * Use: Opens a tunnel device. This will run with root privileges
98 * even if the rest of the server has dropped them.
101 static int t_open(char **ifn)
106 if ((fd = open("/dev/net/tun", O_RDWR)) < 0) {
107 a_warn("TUN", "-", "linux",
108 "open-error", "/dev/net/tun", "?ERRNO",
112 memset(&iff, 0, sizeof(iff));
114 iff.ifr_flags = IFF_TUN | IFF_NO_PI;
115 if (ioctl(fd, TUNSETIFF, &iff) < 0) {
116 a_warn("TUN", "-", "linux", "config-error", "?ERRNO", A_END);
120 iff.ifr_name[IFNAMSIZ - 1] = 0;
121 *ifn = xstrdup(iff.ifr_name);
125 /* --- @t_create@ --- *
127 * Arguments: @peer *p@ = pointer to peer block
128 * @int fd@ = file descriptor of tunnel device
129 * @char **ifn@ = where to put the interface name
131 * Returns: A tunnel block if it worked, or null on failure.
133 * Use: Initializes a new tunnel.
136 static tunnel *t_create(peer *p, int fd, char **ifn)
140 fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
144 sel_initfile(&sel, &t->f, fd, SEL_READ, t_read, t);
149 /* --- @t_inject@ --- *
151 * Arguments: @tunnel *t@ = pointer to tunnel block
152 * @buf *b@ = buffer to send
156 * Use: Injects a packet into the local network stack.
159 static void t_inject(tunnel *t, buf *b)
161 IF_TRACING(T_TUNNEL, {
162 trace(T_TUNNEL, "tun-linux: inject decrypted packet");
163 trace_block(T_PACKET, "tunnel: packet contents", BBASE(b), BLEN(b));
165 write(t->f.fd, BBASE(b), BLEN(b));
168 /* --- @t_destroy@ --- *
170 * Arguments: @tunnel *t@ = pointer to tunnel block
174 * Use: Destroys a tunnel.
177 static void t_destroy(tunnel *t)
178 { sel_rmfile(&t->f); close(t->f.fd); DESTROY(t); }
180 const tunnel_ops tun_linux = {
192 /*----- That's all, folks -------------------------------------------------*/