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"
35 typedef enum device_type_t {
41 static device_type_t device_type;
44 static char ifrname[IFNAMSIZ];
45 static char *device_info;
47 uint64_t device_in_packets = 0;
48 uint64_t device_in_bytes = 0;
49 uint64_t device_out_packets = 0;
50 uint64_t device_out_bytes = 0;
52 bool setup_device(void) {
53 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
54 device = xstrdup(DEFAULT_DEVICE);
56 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
57 #ifdef HAVE_LINUX_IF_TUN_H
59 iface = xstrdup(netname);
61 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
63 device_fd = open(device, O_RDWR | O_NONBLOCK);
66 logger(LOG_ERR, "Could not open %s: %s", device, strerror(errno));
70 struct ifreq ifr = {{{0}}};
72 if(routing_mode == RMODE_ROUTER) {
73 ifr.ifr_flags = IFF_TUN;
74 device_type = DEVICE_TYPE_TUN;
75 device_info = "Linux tun/tap device (tun mode)";
77 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
78 device_type = DEVICE_TYPE_TAP;
79 device_info = "Linux tun/tap device (tap mode)";
83 /* Set IFF_ONE_QUEUE flag... */
86 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
87 ifr.ifr_flags |= IFF_ONE_QUEUE;
91 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
93 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
94 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
95 if(iface) free(iface);
96 iface = xstrdup(ifrname);
97 } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
98 logger(LOG_WARNING, "Old ioctl() request was needed for %s", device);
99 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
100 if(iface) free(iface);
101 iface = xstrdup(ifrname);
104 logger(LOG_INFO, "%s is a %s", device, device_info);
109 void close_device(void) {
116 bool read_packet(vpn_packet_t *packet) {
119 switch(device_type) {
120 case DEVICE_TYPE_TUN:
121 inlen = read(device_fd, packet->data + 10, MTU - 10);
124 logger(LOG_ERR, "Error while reading from %s %s: %s",
125 device_info, device, strerror(errno));
129 packet->len = inlen + 10;
131 case DEVICE_TYPE_TAP:
132 inlen = read(device_fd, packet->data, MTU);
135 logger(LOG_ERR, "Error while reading from %s %s: %s",
136 device_info, device, strerror(errno));
147 device_in_bytes += packet->len;
149 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
155 bool write_packet(vpn_packet_t *packet) {
156 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
157 packet->len, device_info);
159 switch(device_type) {
160 case DEVICE_TYPE_TUN:
161 packet->data[10] = packet->data[11] = 0;
162 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
163 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
168 case DEVICE_TYPE_TAP:
169 if(write(device_fd, packet->data, packet->len) < 0) {
170 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
179 device_out_packets++;
180 device_out_bytes += packet->len;
185 void dump_device_stats(void) {
186 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
187 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_in_bytes);
188 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_out_bytes);