2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2005 Ivo Timmermans,
4 2001-2006 Guus Sliepen <guus@tinc-vpn.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.
25 #include <linux/if_tun.h>
26 #define DEFAULT_DEVICE "/dev/net/tun"
34 typedef enum device_type_t {
41 static device_type_t device_type;
44 char ifrname[IFNAMSIZ];
47 static int device_total_in = 0;
48 static int device_total_out = 0;
50 bool setup_device(void)
56 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
57 device = DEFAULT_DEVICE;
59 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
63 iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
65 device_fd = open(device, O_RDWR | O_NONBLOCK);
68 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
73 /* Ok now check if this is an old ethertap or a new tun/tap thingie */
75 memset(&ifr, 0, sizeof(ifr));
76 if(routing_mode == RMODE_ROUTER) {
77 ifr.ifr_flags = IFF_TUN;
78 device_type = DEVICE_TYPE_TUN;
79 device_info = _("Linux tun/tap device (tun mode)");
81 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
82 device_type = DEVICE_TYPE_TAP;
83 device_info = _("Linux tun/tap device (tap mode)");
87 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
89 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
90 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
92 } else if(!ioctl(device_fd, (('T' << 8) | 202), &ifr)) {
93 logger(LOG_WARNING, _("Old ioctl() request was needed for %s"), device);
94 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
99 if(routing_mode == RMODE_ROUTER)
100 overwrite_mac = true;
101 device_info = _("Linux ethertap device");
102 device_type = DEVICE_TYPE_ETHERTAP;
103 iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
106 logger(LOG_INFO, _("%s is a %s"), device, device_info);
111 void close_device(void)
118 bool read_packet(vpn_packet_t *packet)
124 switch(device_type) {
125 case DEVICE_TYPE_TUN:
126 lenin = read(device_fd, packet->data + 10, MTU - 10);
129 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
130 device_info, device, strerror(errno));
134 packet->len = lenin + 10;
136 case DEVICE_TYPE_TAP:
137 lenin = read(device_fd, packet->data, MTU);
140 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
141 device_info, device, strerror(errno));
147 case DEVICE_TYPE_ETHERTAP:
148 lenin = read(device_fd, packet->data - 2, MTU + 2);
151 logger(LOG_ERR, _("Error while reading from %s %s: %s"),
152 device_info, device, strerror(errno));
156 packet->len = lenin - 2;
160 device_total_in += packet->len;
162 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"), packet->len,
168 bool write_packet(vpn_packet_t *packet)
172 ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
173 packet->len, device_info);
175 switch(device_type) {
176 case DEVICE_TYPE_TUN:
177 packet->data[10] = packet->data[11] = 0;
178 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
179 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
184 case DEVICE_TYPE_TAP:
185 if(write(device_fd, packet->data, packet->len) < 0) {
186 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
191 case DEVICE_TYPE_ETHERTAP:
192 *(short int *)(packet->data - 2) = packet->len;
194 if(write(device_fd, packet->data - 2, packet->len + 2) < 0) {
195 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
202 device_total_out += packet->len;
207 void dump_device_stats(void)
211 logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
212 logger(LOG_DEBUG, _(" total bytes in: %10d"), device_total_in);
213 logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);