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 #include <linux/if_tun.h>
24 #define DEFAULT_DEVICE "/dev/net/tun"
34 typedef enum device_type_t {
40 static device_type_t device_type;
43 static char ifrname[IFNAMSIZ];
44 static char *device_info;
46 uint64_t device_in_packets = 0;
47 uint64_t device_in_bytes = 0;
48 uint64_t device_out_packets = 0;
49 uint64_t device_out_bytes = 0;
51 bool setup_device(void) {
52 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
53 device = xstrdup(DEFAULT_DEVICE);
55 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
56 #ifdef HAVE_LINUX_IF_TUN_H
58 iface = xstrdup(netname);
60 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
62 device_fd = open(device, O_RDWR | O_NONBLOCK);
65 logger(LOG_ERR, "Could not open %s: %s", device, strerror(errno));
69 struct ifreq ifr = {{{0}}};
71 if(routing_mode == RMODE_ROUTER) {
72 ifr.ifr_flags = IFF_TUN;
73 device_type = DEVICE_TYPE_TUN;
74 device_info = "Linux tun/tap device (tun mode)";
76 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
77 device_type = DEVICE_TYPE_TAP;
78 device_info = "Linux tun/tap device (tap mode)";
82 /* Set IFF_ONE_QUEUE flag... */
85 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
86 ifr.ifr_flags |= IFF_ONE_QUEUE;
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);
103 logger(LOG_INFO, "%s is a %s", device, device_info);
108 void close_device(void) {
115 bool read_packet(vpn_packet_t *packet) {
118 switch(device_type) {
119 case DEVICE_TYPE_TUN:
120 inlen = read(device_fd, packet->data + 10, MTU - 10);
123 logger(LOG_ERR, "Error while reading from %s %s: %s",
124 device_info, device, strerror(errno));
128 packet->len = inlen + 10;
130 case DEVICE_TYPE_TAP:
131 inlen = read(device_fd, packet->data, MTU);
134 logger(LOG_ERR, "Error while reading from %s %s: %s",
135 device_info, device, strerror(errno));
146 device_in_bytes += packet->len;
148 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
154 bool write_packet(vpn_packet_t *packet) {
155 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
156 packet->len, device_info);
158 switch(device_type) {
159 case DEVICE_TYPE_TUN:
160 packet->data[10] = packet->data[11] = 0;
161 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
162 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
167 case DEVICE_TYPE_TAP:
168 if(write(device_fd, packet->data, packet->len) < 0) {
169 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
178 device_out_packets++;
179 device_out_bytes += packet->len;
184 void dump_device_stats(void) {
185 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
186 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_in_bytes);
187 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_out_bytes);