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 uint64_t device_total_in = 0;
51 static uint64_t device_total_out = 0;
53 bool setup_device(void) {
57 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
58 device = xstrdup(DEFAULT_DEVICE);
60 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
61 #ifdef HAVE_LINUX_IF_TUN_H
63 iface = xstrdup(netname);
65 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
67 device_fd = open(device, O_RDWR | O_NONBLOCK);
70 logger(LOG_ERR, "Could not open %s: %s", device, strerror(errno));
74 #ifdef HAVE_LINUX_IF_TUN_H
75 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
77 memset(&ifr, 0, sizeof ifr);
78 if(routing_mode == RMODE_ROUTER) {
79 ifr.ifr_flags = IFF_TUN;
80 device_type = DEVICE_TYPE_TUN;
81 device_info = "Linux tun/tap device (tun mode)";
83 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
84 device_type = DEVICE_TYPE_TAP;
85 device_info = "Linux tun/tap device (tap mode)";
89 /* Set IFF_ONE_QUEUE flag... */
90 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
91 ifr.ifr_flags |= IFF_ONE_QUEUE;
95 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
97 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
98 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
99 if(iface) free(iface);
100 iface = xstrdup(ifrname);
101 } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
102 logger(LOG_WARNING, "Old ioctl() request was needed for %s", device);
103 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
104 if(iface) free(iface);
105 iface = xstrdup(ifrname);
109 if(routing_mode == RMODE_ROUTER)
110 overwrite_mac = true;
111 device_info = "Linux ethertap device";
112 device_type = DEVICE_TYPE_ETHERTAP;
115 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
118 logger(LOG_INFO, "%s is a %s", device, device_info);
123 void close_device(void) {
130 bool read_packet(vpn_packet_t *packet) {
133 switch(device_type) {
134 case DEVICE_TYPE_TUN:
135 inlen = read(device_fd, packet->data + 10, MTU - 10);
138 logger(LOG_ERR, "Error while reading from %s %s: %s",
139 device_info, device, strerror(errno));
143 packet->len = inlen + 10;
145 case DEVICE_TYPE_TAP:
146 inlen = read(device_fd, packet->data, MTU);
149 logger(LOG_ERR, "Error while reading from %s %s: %s",
150 device_info, device, strerror(errno));
156 case DEVICE_TYPE_ETHERTAP:
157 inlen = read(device_fd, packet->data - 2, MTU + 2);
160 logger(LOG_ERR, "Error while reading from %s %s: %s",
161 device_info, device, strerror(errno));
165 packet->len = inlen - 2;
169 device_total_in += packet->len;
171 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
177 bool write_packet(vpn_packet_t *packet) {
178 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
179 packet->len, device_info);
181 switch(device_type) {
182 case DEVICE_TYPE_TUN:
183 packet->data[10] = packet->data[11] = 0;
184 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
185 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
190 case DEVICE_TYPE_TAP:
191 if(write(device_fd, packet->data, packet->len) < 0) {
192 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
197 case DEVICE_TYPE_ETHERTAP:
198 *(short int *)(packet->data - 2) = packet->len;
200 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
201 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
208 device_total_out += packet->len;
213 void dump_device_stats(void) {
214 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
215 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
216 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);