2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2003 Ivo Timmermans <ivo@o2w.nl>,
4 2001-2003 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 1.1.2.17 2003/07/12 17:41:48 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;
70 int setup_device(void)
76 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
77 device = DEFAULT_DEVICE;
79 if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
83 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
85 device_fd = open(device, O_RDWR | O_NONBLOCK);
88 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
93 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
95 memset(&ifr, 0, sizeof(ifr));
96 if(routing_mode == RMODE_ROUTER) {
97 ifr.ifr_flags = IFF_TUN;
98 device_type = DEVICE_TYPE_TUN;
99 device_info = _("Linux tun/tap device (tun mode)");
101 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
102 device_type = DEVICE_TYPE_TAP;
103 device_info = _("Linux tun/tap device (tap mode)");
107 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
109 if(!ioctl(device_fd, TUNSETIFF, (void *) &ifr)) {
110 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
112 } else if(!ioctl(device_fd, (('T' << 8) | 202), (void *) &ifr)) {
113 logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
114 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
119 if(routing_mode == RMODE_ROUTER)
121 device_info = _("Linux ethertap device");
122 device_type = DEVICE_TYPE_ETHERTAP;
123 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
126 logger(LOG_INFO, _("%s is a %s"), device, device_info);
131 void close_device(void)
138 int read_packet(vpn_packet_t *packet)
144 switch(device_type) {
145 case DEVICE_TYPE_TUN:
146 lenin = read(device_fd, packet->data + 10, MTU - 10);
149 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
150 device_info, device, strerror(errno));
154 packet->len = lenin + 10;
156 case DEVICE_TYPE_TAP:
157 lenin = read(device_fd, packet->data, MTU);
160 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
161 device_info, device, strerror(errno));
167 case DEVICE_TYPE_ETHERTAP:
168 lenin = read(device_fd, packet->data - 2, MTU + 2);
171 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
172 device_info, device, strerror(errno));
176 packet->len = lenin - 2;
180 device_total_in += packet->len;
182 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
188 int write_packet(vpn_packet_t *packet)
192 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
193 packet->len, device_info);
195 switch(device_type) {
196 case DEVICE_TYPE_TUN:
197 packet->data[10] = packet->data[11] = 0;
198 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
199 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
204 case DEVICE_TYPE_TAP:
205 if(write(device_fd, packet->data, packet->len) < 0) {
206 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
211 case DEVICE_TYPE_ETHERTAP:
212 *(short int *)(packet->data - 2) = packet->len;
214 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
215 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
222 device_total_out += packet->len;
227 void dump_device_stats(void)
231 logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
232 logger(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
233 logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);