2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2002 Ivo Timmermans <ivo@o2w.nl>,
4 2001-2002 Guus Sliepen <guus@sliepen.eu.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.
20 $Id: device.c,v 1.1.2.14 2003/06/11 19:09:52 guus Exp $
27 #include <sys/types.h>
34 #include <sys/ioctl.h>
38 #include LINUX_IF_TUN_H
40 #include <linux/if_tun.h>
42 #define DEFAULT_DEVICE "/dev/net/tun"
44 #define DEFAULT_DEVICE "/dev/tap0"
65 char ifrname[IFNAMSIZ];
68 int device_total_in = 0;
69 int device_total_out = 0;
71 extern subnet_t mymac;
74 open the local ethertap device
76 int setup_device(void)
82 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
83 device = DEFAULT_DEVICE;
85 if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
89 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
91 device_fd = open(device, O_RDWR | O_NONBLOCK);
94 syslog(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
98 /* Set default MAC address for ethertap devices */
99 mymac.type = SUBNET_MAC;
100 mymac.net.mac.address.x[0] = 0xfe;
101 mymac.net.mac.address.x[1] = 0xfd;
102 mymac.net.mac.address.x[2] = 0x00;
103 mymac.net.mac.address.x[3] = 0x00;
104 mymac.net.mac.address.x[4] = 0x00;
105 mymac.net.mac.address.x[5] = 0x00;
108 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
110 memset(&ifr, 0, sizeof(ifr));
111 if(routing_mode == RMODE_ROUTER) {
112 ifr.ifr_flags = IFF_TUN;
113 device_type = DEVICE_TYPE_TUN;
114 device_info = _("Linux tun/tap device (tun mode)");
116 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
117 device_type = DEVICE_TYPE_TAP;
118 device_info = _("Linux tun/tap device (tap mode)");
122 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
124 if(!ioctl(device_fd, TUNSETIFF, (void *) &ifr)) {
125 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
127 } else if(!ioctl(device_fd, (('T' << 8) | 202), (void *) &ifr)) {
128 syslog(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
129 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
134 device_info = _("Linux ethertap device");
135 device_type = DEVICE_TYPE_ETHERTAP;
136 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
139 syslog(LOG_INFO, _("%s is a %s"), device, device_info);
144 void close_device(void)
152 read, encrypt and send data that is
153 available through the ethertap device
155 int read_packet(vpn_packet_t *packet)
161 switch(device_type) {
162 case DEVICE_TYPE_TUN:
163 lenin = read(device_fd, packet->data + 10, MTU - 10);
166 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
167 device_info, device, strerror(errno));
171 packet->len = lenin + 10;
173 case DEVICE_TYPE_TAP:
174 lenin = read(device_fd, packet->data, MTU);
177 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
178 device_info, device, strerror(errno));
184 case DEVICE_TYPE_ETHERTAP:
185 lenin = read(device_fd, packet->data - 2, MTU + 2);
188 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
189 device_info, device, strerror(errno));
193 packet->len = lenin - 2;
197 device_total_in += packet->len;
199 if(debug_lvl >= DEBUG_TRAFFIC) {
200 syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
207 int write_packet(vpn_packet_t *packet)
211 if(debug_lvl >= DEBUG_TRAFFIC)
212 syslog(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
213 packet->len, device_info);
215 switch(device_type) {
216 case DEVICE_TYPE_TUN:
217 packet->data[10] = packet->data[11] = 0;
218 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
219 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
224 case DEVICE_TYPE_TAP:
225 if(write(device_fd, packet->data, packet->len) < 0) {
226 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
231 case DEVICE_TYPE_ETHERTAP:
232 *(short int *)(packet->data - 2) = packet->len;
234 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
235 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
242 device_total_out += packet->len;
247 void dump_device_stats(void)
251 syslog(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
252 syslog(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
253 syslog(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);