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"
37 typedef enum device_type_t {
44 static device_type_t device_type;
47 static char ifrname[IFNAMSIZ];
48 static char *device_info;
50 static int device_total_in = 0;
51 static int device_total_out = 0;
53 bool setup_device(void) {
58 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
59 device = xstrdup(DEFAULT_DEVICE);
61 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
62 #ifdef HAVE_LINUX_IF_TUN_H
64 iface = xstrdup(netname);
66 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
68 device_fd = open(device, O_RDWR | O_NONBLOCK);
71 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
75 #ifdef HAVE_LINUX_IF_TUN_H
76 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
78 memset(&ifr, 0, sizeof(ifr));
79 if(routing_mode == RMODE_ROUTER) {
80 ifr.ifr_flags = IFF_TUN;
81 device_type = DEVICE_TYPE_TUN;
82 device_info = _("Linux tun/tap device (tun mode)");
84 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
85 device_type = DEVICE_TYPE_TAP;
86 device_info = _("Linux tun/tap device (tap mode)");
90 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
92 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
93 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
94 if(iface) free(iface);
95 iface = xstrdup(ifrname);
96 } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
97 logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
98 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
99 if(iface) free(iface);
100 iface = xstrdup(ifrname);
104 if(routing_mode == RMODE_ROUTER)
105 overwrite_mac = true;
106 device_info = _("Linux ethertap device");
107 device_type = DEVICE_TYPE_ETHERTAP;
110 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
113 logger(LOG_INFO, _("%s is a %s"), device, device_info);
118 void close_device(void) {
127 bool read_packet(vpn_packet_t *packet) {
132 switch(device_type) {
133 case DEVICE_TYPE_TUN:
134 lenin = read(device_fd, packet->data + 10, MTU - 10);
137 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
138 device_info, device, strerror(errno));
142 packet->len = lenin + 10;
144 case DEVICE_TYPE_TAP:
145 lenin = read(device_fd, packet->data, MTU);
148 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
149 device_info, device, strerror(errno));
155 case DEVICE_TYPE_ETHERTAP:
156 lenin = read(device_fd, packet->data - 2, MTU + 2);
159 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
160 device_info, device, strerror(errno));
164 packet->len = lenin - 2;
168 device_total_in += packet->len;
170 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
176 bool write_packet(vpn_packet_t *packet) {
179 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
180 packet->len, device_info);
182 switch(device_type) {
183 case DEVICE_TYPE_TUN:
184 packet->data[10] = packet->data[11] = 0;
185 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
186 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
191 case DEVICE_TYPE_TAP:
192 if(write(device_fd, packet->data, packet->len) < 0) {
193 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
198 case DEVICE_TYPE_ETHERTAP:
199 *(short int *)(packet->data - 2) = packet->len;
201 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
202 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
209 device_total_out += packet->len;
214 void dump_device_stats(void) {
217 logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
218 logger(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
219 logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);