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
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
25 #ifdef HAVE_LINUX_IF_TUN_H
26 #include <linux/if_tun.h>
27 #define DEFAULT_DEVICE "/dev/net/tun"
29 #define DEFAULT_DEVICE "/dev/tap0"
39 typedef enum device_type_t {
46 static device_type_t device_type;
49 static char ifrname[IFNAMSIZ];
50 static char *device_info;
52 static int device_total_in = 0;
53 static int device_total_out = 0;
55 bool setup_device(void) {
60 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
61 device = xstrdup(DEFAULT_DEVICE);
63 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
64 #ifdef HAVE_LINUX_IF_TUN_H
66 iface = xstrdup(netname);
68 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
70 device_fd = open(device, O_RDWR | O_NONBLOCK);
73 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
77 #ifdef HAVE_LINUX_IF_TUN_H
78 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
80 memset(&ifr, 0, sizeof ifr);
81 if(routing_mode == RMODE_ROUTER) {
82 ifr.ifr_flags = IFF_TUN;
83 device_type = DEVICE_TYPE_TUN;
84 device_info = _("Linux tun/tap device (tun mode)");
86 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
87 device_type = DEVICE_TYPE_TAP;
88 device_info = _("Linux tun/tap device (tap mode)");
92 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
94 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
95 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
96 if(iface) free(iface);
97 iface = xstrdup(ifrname);
98 } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
99 logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
100 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
101 if(iface) free(iface);
102 iface = xstrdup(ifrname);
106 if(routing_mode == RMODE_ROUTER)
107 overwrite_mac = true;
108 device_info = _("Linux ethertap device");
109 device_type = DEVICE_TYPE_ETHERTAP;
112 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
115 logger(LOG_INFO, _("%s is a %s"), device, device_info);
120 void close_device(void) {
129 bool read_packet(vpn_packet_t *packet) {
134 switch(device_type) {
135 case DEVICE_TYPE_TUN:
136 inlen = 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 = inlen + 10;
146 case DEVICE_TYPE_TAP:
147 inlen = 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 inlen = 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 = inlen - 2;
170 device_total_in += packet->len;
172 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
178 bool write_packet(vpn_packet_t *packet) {
181 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
182 packet->len, device_info);
184 switch(device_type) {
185 case DEVICE_TYPE_TUN:
186 packet->data[10] = packet->data[11] = 0;
187 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
188 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
193 case DEVICE_TYPE_TAP:
194 if(write(device_fd, packet->data, packet->len) < 0) {
195 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
200 case DEVICE_TYPE_ETHERTAP:
201 *(short int *)(packet->data - 2) = packet->len;
203 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
204 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
211 device_total_out += packet->len;
216 void dump_device_stats(void) {
219 logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
220 logger(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
221 logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);