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 1.1.2.15 2003/06/11 19:28:37 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;
72 open the local ethertap device
74 int setup_device(void)
80 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
81 device = DEFAULT_DEVICE;
83 if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
87 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
89 device_fd = open(device, O_RDWR | O_NONBLOCK);
92 syslog(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
97 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
99 memset(&ifr, 0, sizeof(ifr));
100 if(routing_mode == RMODE_ROUTER) {
101 ifr.ifr_flags = IFF_TUN;
102 device_type = DEVICE_TYPE_TUN;
103 device_info = _("Linux tun/tap device (tun mode)");
105 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
106 device_type = DEVICE_TYPE_TAP;
107 device_info = _("Linux tun/tap device (tap mode)");
111 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
113 if(!ioctl(device_fd, TUNSETIFF, (void *) &ifr)) {
114 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
116 } else if(!ioctl(device_fd, (('T' << 8) | 202), (void *) &ifr)) {
117 syslog(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
118 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
123 if(routing_mode == RMODE_ROUTER)
125 device_info = _("Linux ethertap device");
126 device_type = DEVICE_TYPE_ETHERTAP;
127 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
130 syslog(LOG_INFO, _("%s is a %s"), device, device_info);
135 void close_device(void)
143 read, encrypt and send data that is
144 available through the ethertap device
146 int read_packet(vpn_packet_t *packet)
152 switch(device_type) {
153 case DEVICE_TYPE_TUN:
154 lenin = read(device_fd, packet->data + 10, MTU - 10);
157 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
158 device_info, device, strerror(errno));
162 packet->len = lenin + 10;
164 case DEVICE_TYPE_TAP:
165 lenin = read(device_fd, packet->data, MTU);
168 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
169 device_info, device, strerror(errno));
175 case DEVICE_TYPE_ETHERTAP:
176 lenin = read(device_fd, packet->data - 2, MTU + 2);
179 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
180 device_info, device, strerror(errno));
184 packet->len = lenin - 2;
188 device_total_in += packet->len;
190 if(debug_lvl >= DEBUG_TRAFFIC) {
191 syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
198 int write_packet(vpn_packet_t *packet)
202 if(debug_lvl >= DEBUG_TRAFFIC)
203 syslog(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
204 packet->len, device_info);
206 switch(device_type) {
207 case DEVICE_TYPE_TUN:
208 packet->data[10] = packet->data[11] = 0;
209 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
210 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
215 case DEVICE_TYPE_TAP:
216 if(write(device_fd, packet->data, packet->len) < 0) {
217 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
222 case DEVICE_TYPE_ETHERTAP:
223 *(short int *)(packet->data - 2) = packet->len;
225 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
226 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
233 device_total_out += packet->len;
238 void dump_device_stats(void)
242 syslog(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
243 syslog(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
244 syslog(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);