2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2005 Ivo Timmermans,
4 2001-2011 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"
38 typedef enum device_type_t {
45 static device_type_t device_type;
48 static char ifrname[IFNAMSIZ];
49 static char *device_info;
51 static uint64_t device_total_in = 0;
52 static uint64_t device_total_out = 0;
54 static 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(strrchr(device, '/') ? strrchr(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 /* Set IFF_ONE_QUEUE flag... */
91 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
92 ifr.ifr_flags |= IFF_ONE_QUEUE;
96 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
98 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
99 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
100 if(iface) free(iface);
101 iface = xstrdup(ifrname);
102 } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
103 logger(LOG_WARNING, "Old ioctl() request was needed for %s", device);
104 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
105 if(iface) free(iface);
106 iface = xstrdup(ifrname);
110 if(routing_mode == RMODE_ROUTER)
111 overwrite_mac = true;
112 device_info = "Linux ethertap device";
113 device_type = DEVICE_TYPE_ETHERTAP;
116 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
119 logger(LOG_INFO, "%s is a %s", device, device_info);
124 static void close_device(void) {
131 static bool read_packet(vpn_packet_t *packet) {
134 switch(device_type) {
135 case DEVICE_TYPE_TUN:
136 lenin = read(device_fd, packet->data + 10, MTU - 10);
139 logger(LOG_ERR, "Error while reading from %s %s: %s",
140 device_info, device, strerror(errno));
144 packet->len = lenin + 10;
146 case DEVICE_TYPE_TAP:
147 lenin = read(device_fd, packet->data, MTU);
150 logger(LOG_ERR, "Error while reading from %s %s: %s",
151 device_info, device, strerror(errno));
157 case DEVICE_TYPE_ETHERTAP:
158 lenin = read(device_fd, packet->data - 2, MTU + 2);
161 logger(LOG_ERR, "Error while reading from %s %s: %s",
162 device_info, device, strerror(errno));
166 packet->len = lenin - 2;
170 device_total_in += packet->len;
172 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
178 static 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 static void dump_device_stats(void) {
215 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
216 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
217 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
220 const devops_t os_devops = {
221 .setup = setup_device,
222 .close = close_device,
224 .write = write_packet,
225 .dump_stats = dump_device_stats,