2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2005 Ivo Timmermans,
4 2001-2009 Guus Sliepen <guus@tinc-vpn.org>
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 #ifdef HAVE_LINUX_IF_TUN_H
24 #include <linux/if_tun.h>
25 #define DEFAULT_DEVICE "/dev/net/tun"
27 #define DEFAULT_DEVICE "/dev/tap0"
39 typedef enum device_type_t {
47 static device_type_t device_type;
50 static char ifrname[IFNAMSIZ];
51 static char *device_info;
53 static uint64_t device_total_in = 0;
54 static uint64_t device_total_out = 0;
58 static void read_thread(void *arg) {
59 static vpn_packet_t packet;
63 if(read_packet(&packet)) {
64 route(myself, &packet);
66 if(errno == EAGAIN || errno == EINTR) {
76 bool setup_device(void) {
80 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
81 device = xstrdup(DEFAULT_DEVICE);
83 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
84 #ifdef HAVE_LINUX_IF_TUN_H
86 iface = xstrdup(netname);
88 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
90 fd = open(device, O_RDWR);
93 logger(LOG_ERR, "Could not open %s: %s", device, strerror(errno));
97 #ifdef HAVE_LINUX_IF_TUN_H
98 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
100 memset(&ifr, 0, sizeof ifr);
101 if(routing_mode == RMODE_ROUTER) {
102 ifr.ifr_flags = IFF_TUN;
103 device_type = DEVICE_TYPE_TUN;
104 device_info = "Linux tun/tap device (tun mode)";
106 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
107 device_type = DEVICE_TYPE_TAP;
108 device_info = "Linux tun/tap device (tap mode)";
112 /* Set IFF_ONE_QUEUE flag... */
113 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
114 ifr.ifr_flags |= IFF_ONE_QUEUE;
118 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
120 if(!ioctl(fd, TUNSETIFF, &ifr)) {
121 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
122 if(iface) free(iface);
123 iface = xstrdup(ifrname);
124 } else if(!ioctl(fd, (('T' << 8) | 202), &ifr)) {
125 logger(LOG_WARNING, "Old ioctl() request was needed for %s", device);
126 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
127 if(iface) free(iface);
128 iface = xstrdup(ifrname);
132 if(routing_mode == RMODE_ROUTER)
133 overwrite_mac = true;
134 device_info = "Linux ethertap device";
135 device_type = DEVICE_TYPE_ETHERTAP;
138 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
141 logger(LOG_INFO, "%s is a %s", device, device_info);
143 return thread_create(&thread, read_thread, NULL);
146 void close_device(void) {
148 thread_destroy(&thread);
154 bool read_packet(vpn_packet_t *packet) {
157 switch(device_type) {
158 case DEVICE_TYPE_TUN:
159 inlen = read(fd, packet->data + 10, MTU - 10);
162 logger(LOG_ERR, "Error while reading from %s %s: %s",
163 device_info, device, strerror(errno));
167 packet->len = inlen + 10;
169 case DEVICE_TYPE_TAP:
170 inlen = read(fd, packet->data, MTU);
173 logger(LOG_ERR, "Error while reading from %s %s: %s",
174 device_info, device, strerror(errno));
180 case DEVICE_TYPE_ETHERTAP:
181 inlen = read(fd, packet->data - 2, MTU + 2);
184 logger(LOG_ERR, "Error while reading from %s %s: %s",
185 device_info, device, strerror(errno));
189 packet->len = inlen - 2;
193 device_total_in += packet->len;
195 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
201 bool write_packet(vpn_packet_t *packet) {
202 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
203 packet->len, device_info);
205 switch(device_type) {
206 case DEVICE_TYPE_TUN:
207 packet->data[10] = packet->data[11] = 0;
208 if(write(fd, packet->data + 10, packet->len - 10) < 0) {
209 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
214 case DEVICE_TYPE_TAP:
215 if(write(fd, packet->data, packet->len) < 0) {
216 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
221 case DEVICE_TYPE_ETHERTAP:
222 *(short int *)(packet->data - 2) = packet->len;
224 if(write(fd, packet->data - 2, packet->len + 2) < 0) {
225 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
232 device_total_out += packet->len;
237 void dump_device_stats(void) {
238 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
239 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
240 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);