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 1.1.2.12 2002/09/09 22:33:24 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/misc/net/tun"
44 #define DEFAULT_DEVICE "/dev/tap0"
54 #define DEVICE_TYPE_ETHERTAP 0
55 #define DEVICE_TYPE_TUNTAP 1
61 char ifrname[IFNAMSIZ];
64 int device_total_in = 0;
65 int device_total_out = 0;
67 extern subnet_t mymac;
70 open the local ethertap device
72 int setup_device(void)
78 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
79 device = DEFAULT_DEVICE;
81 if(!get_config_string(lookup_config(config_tree, "Interface"), &interface))
85 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
87 device_fd = open(device, O_RDWR | O_NONBLOCK);
90 syslog(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
94 /* Set default MAC address for ethertap devices */
95 mymac.type = SUBNET_MAC;
96 mymac.net.mac.address.x[0] = 0xfe;
97 mymac.net.mac.address.x[1] = 0xfd;
98 mymac.net.mac.address.x[2] = 0x00;
99 mymac.net.mac.address.x[3] = 0x00;
100 mymac.net.mac.address.x[4] = 0x00;
101 mymac.net.mac.address.x[5] = 0x00;
104 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
106 memset(&ifr, 0, sizeof(ifr));
107 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
110 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
112 if(!ioctl(device_fd, TUNSETIFF, (void *) &ifr)) {
113 device_info = _("Linux tun/tap device");
114 device_type = DEVICE_TYPE_TUNTAP;
115 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
117 } else if(!ioctl(device_fd, (('T' << 8) | 202), (void *) &ifr)) {
118 syslog(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
119 device_type = DEVICE_TYPE_TUNTAP;
120 device_info = _("Linux tun/tap device");
121 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
126 device_info = _("Linux ethertap device");
127 device_type = DEVICE_TYPE_ETHERTAP;
128 interface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
131 syslog(LOG_INFO, _("%s is a %s"), device, device_info);
136 void close_device(void)
144 read, encrypt and send data that is
145 available through the ethertap device
147 int read_packet(vpn_packet_t *packet)
153 if(device_type == DEVICE_TYPE_TUNTAP) {
154 lenin = read(device_fd, packet->data, MTU);
157 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
158 device_info, device, strerror(errno));
163 } else { /* ethertap */
165 lenin = read(device_fd, packet->data - 2, MTU + 2);
168 syslog(LOG_ERR, _("Error while reading from %s %s: %s"),
169 device_info, device, strerror(errno));
173 packet->len = lenin - 2;
176 device_total_in += packet->len;
178 if(debug_lvl >= DEBUG_TRAFFIC) {
179 syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
186 int write_packet(vpn_packet_t *packet)
190 if(debug_lvl >= DEBUG_TRAFFIC)
191 syslog(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
192 packet->len, device_info);
194 if(device_type == DEVICE_TYPE_TUNTAP) {
195 if(write(device_fd, packet->data, packet->len) < 0) {
196 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
200 } else { /* ethertap */
201 *(short int *)(packet->data - 2) = packet->len;
203 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
204 syslog(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
210 device_total_out += packet->len;
215 void dump_device_stats(void)
219 syslog(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
220 syslog(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
221 syslog(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);