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 1.1.2.16 2003/07/06 22:11:35 guus Exp $
27 #include <sys/types.h>
33 #include <sys/ioctl.h>
37 #include LINUX_IF_TUN_H
39 #include <linux/if_tun.h>
41 #define DEFAULT_DEVICE "/dev/net/tun"
43 #define DEFAULT_DEVICE "/dev/tap0"
64 char ifrname[IFNAMSIZ];
67 int device_total_in = 0;
68 int device_total_out = 0;
71 open the local ethertap device
73 int setup_device(void)
79 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
80 device = DEFAULT_DEVICE;
82 if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
86 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
88 device_fd = open(device, O_RDWR | O_NONBLOCK);
91 logger(DEBUG_ALWAYS, LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
96 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
98 memset(&ifr, 0, sizeof(ifr));
99 if(routing_mode == RMODE_ROUTER) {
100 ifr.ifr_flags = IFF_TUN;
101 device_type = DEVICE_TYPE_TUN;
102 device_info = _("Linux tun/tap device (tun mode)");
104 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
105 device_type = DEVICE_TYPE_TAP;
106 device_info = _("Linux tun/tap device (tap mode)");
110 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
112 if(!ioctl(device_fd, TUNSETIFF, (void *) &ifr)) {
113 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
115 } else if(!ioctl(device_fd, (('T' << 8) | 202), (void *) &ifr)) {
116 logger(DEBUG_ALWAYS, LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
117 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
122 if(routing_mode == RMODE_ROUTER)
124 device_info = _("Linux ethertap device");
125 device_type = DEVICE_TYPE_ETHERTAP;
126 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
129 logger(DEBUG_ALWAYS, LOG_INFO, _("%s is a %s"), device, device_info);
134 void close_device(void)
142 read, encrypt and send data that is
143 available through the ethertap device
145 int read_packet(vpn_packet_t *packet)
151 switch(device_type) {
152 case DEVICE_TYPE_TUN:
153 lenin = read(device_fd, packet->data + 10, MTU - 10);
156 logger(DEBUG_ALWAYS, LOG_ERR, _("Error while reading from %s %s: %s"),
157 device_info, device, strerror(errno));
161 packet->len = lenin + 10;
163 case DEVICE_TYPE_TAP:
164 lenin = read(device_fd, packet->data, MTU);
167 logger(DEBUG_ALWAYS, LOG_ERR, _("Error while reading from %s %s: %s"),
168 device_info, device, strerror(errno));
174 case DEVICE_TYPE_ETHERTAP:
175 lenin = read(device_fd, packet->data - 2, MTU + 2);
178 logger(DEBUG_ALWAYS, LOG_ERR, _("Error while reading from %s %s: %s"),
179 device_info, device, strerror(errno));
183 packet->len = lenin - 2;
187 device_total_in += packet->len;
189 logger(DEBUG_TRAFFIC, LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
195 int write_packet(vpn_packet_t *packet)
199 logger(DEBUG_TRAFFIC, LOG_DEBUG, _("Writing packet of %d bytes to %s"),
200 packet->len, device_info);
202 switch(device_type) {
203 case DEVICE_TYPE_TUN:
204 packet->data[10] = packet->data[11] = 0;
205 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
206 logger(DEBUG_ALWAYS, LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
211 case DEVICE_TYPE_TAP:
212 if(write(device_fd, packet->data, packet->len) < 0) {
213 logger(DEBUG_ALWAYS, LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
218 case DEVICE_TYPE_ETHERTAP:
219 *(short int *)(packet->data - 2) = packet->len;
221 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
222 logger(DEBUG_ALWAYS, LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
229 device_total_out += packet->len;
234 void dump_device_stats(void)
238 logger(DEBUG_ALWAYS, LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
239 logger(DEBUG_ALWAYS, LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
240 logger(DEBUG_ALWAYS, LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);