2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2002 Ivo Timmermans <itimmermans@bigfoot.com>,
4 2001-2002 Guus Sliepen <guus@sliepen.warande.net>
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 1.1.2.5 2002/02/10 21:57:54 guus Exp $
26 #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/misc/net/tun"
43 #define DEFAULT_DEVICE "/dev/tap0"
53 #define DEVICE_TYPE_ETHERTAP 0
54 #define DEVICE_TYPE_TUNTAP 1
60 char ifrname[IFNAMSIZ];
63 int device_total_in = 0;
64 int device_total_out = 0;
66 extern subnet_t mymac;
69 open the local ethertap device
71 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))
82 if((device_fd = open(device, O_RDWR | O_NONBLOCK)) < 0)
84 syslog(LOG_ERR, _("Could not open %s: %m"), device);
88 /* Set default MAC address for ethertap devices */
90 mymac.type = SUBNET_MAC;
91 mymac.net.mac.address.x[0] = 0xfe;
92 mymac.net.mac.address.x[1] = 0xfd;
93 mymac.net.mac.address.x[2] = 0x00;
94 mymac.net.mac.address.x[3] = 0x00;
95 mymac.net.mac.address.x[4] = 0x00;
96 mymac.net.mac.address.x[5] = 0x00;
99 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
101 memset(&ifr, 0, sizeof(ifr));
103 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
105 strncpy(ifr.ifr_name, interface, IFNAMSIZ);
107 if (!ioctl(device_fd, TUNSETIFF, (void *) &ifr))
109 device_info = _("Linux tun/tap device");
110 device_type = DEVICE_TYPE_TUNTAP;
111 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
115 if (!ioctl(device_fd, (('T'<< 8) | 202), (void *) &ifr))
117 syslog(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
118 device_type = DEVICE_TYPE_TUNTAP;
119 device_info = _("Linux tun/tap device");
120 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
126 device_info = _("Linux ethertap device");
127 device_type = DEVICE_TYPE_ETHERTAP;
130 syslog(LOG_INFO, _("%s is a %s"), device, device_info);
135 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)
149 if(device_type == DEVICE_TYPE_TUNTAP)
151 if((lenin = read(device_fd, packet->data, MTU)) <= 0)
153 syslog(LOG_ERR, _("Error while reading from %s %s: %m"), device_info, device);
161 if((lenin = read(device_fd, packet->data - 2, MTU + 2)) <= 0)
163 syslog(LOG_ERR, _("Error while reading from %s %s: %m"), device_info, device);
167 packet->len = lenin - 2;
170 device_total_in += packet->len;
172 if(debug_lvl >= DEBUG_TRAFFIC)
174 syslog(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len, device_info);
181 int write_packet(vpn_packet_t *packet)
184 if(debug_lvl >= DEBUG_TRAFFIC)
185 syslog(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
186 packet->len, device_info);
188 if(device_type == DEVICE_TYPE_TUNTAP)
190 if(write(device_fd, packet->data, packet->len) < 0)
192 syslog(LOG_ERR, _("Can't write to %s %s: %m"), device_info, device);
198 *(short int *)(packet->data - 2) = packet->len;
199 if(write(device_fd, packet->data - 2, packet->len + 2) < 0)
201 syslog(LOG_ERR, _("Can't write to %s %s: %m"), device_info, device);
206 device_total_out += packet->len;
211 void dump_device_stats(void)
214 syslog(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
215 syslog(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
216 syslog(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);