2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2005 Ivo Timmermans,
4 2001-2012 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 along
17 with this program; if not, write to the Free Software Foundation, Inc.,
18 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
23 #include <linux/if_tun.h>
24 #define DEFAULT_DEVICE "/dev/net/tun"
35 typedef enum device_type_t {
41 static device_type_t device_type;
44 static char *type = NULL;
45 static char ifrname[IFNAMSIZ];
46 static char *device_info;
48 uint64_t device_in_packets = 0;
49 uint64_t device_in_bytes = 0;
50 uint64_t device_out_packets = 0;
51 uint64_t device_out_bytes = 0;
53 static bool setup_device(void) {
54 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
55 device = xstrdup(DEFAULT_DEVICE);
57 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
59 iface = xstrdup(netname);
61 device_fd = open(device, O_RDWR | O_NONBLOCK);
64 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open %s: %s", device, strerror(errno));
69 fcntl(device_fd, F_SETFD, FD_CLOEXEC);
72 struct ifreq ifr = {{{0}}};
74 get_config_string(lookup_config(config_tree, "DeviceType"), &type);
76 if(type && strcasecmp(type, "tun") && strcasecmp(type, "tap")) {
77 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown device type %s!", type);
81 if((type && !strcasecmp(type, "tun")) || (!type && routing_mode == RMODE_ROUTER)) {
82 ifr.ifr_flags = IFF_TUN;
83 device_type = DEVICE_TYPE_TUN;
84 device_info = "Linux tun/tap device (tun mode)";
86 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
87 device_type = DEVICE_TYPE_TAP;
88 device_info = "Linux tun/tap device (tap mode)";
92 /* Set IFF_ONE_QUEUE flag... */
95 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
96 ifr.ifr_flags |= IFF_ONE_QUEUE;
100 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
102 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
103 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
105 iface = xstrdup(ifrname);
108 logger(DEBUG_ALWAYS, LOG_INFO, "%s is a %s", device, device_info);
113 static void close_device(void) {
121 static bool read_packet(vpn_packet_t *packet) {
124 switch(device_type) {
125 case DEVICE_TYPE_TUN:
126 inlen = read(device_fd, packet->data + 10, MTU - 10);
129 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s",
130 device_info, device, strerror(errno));
134 packet->len = inlen + 10;
136 case DEVICE_TYPE_TAP:
137 inlen = read(device_fd, packet->data, MTU);
140 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s",
141 device_info, device, strerror(errno));
152 device_in_bytes += packet->len;
154 logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
160 static bool write_packet(vpn_packet_t *packet) {
161 logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
162 packet->len, device_info);
164 switch(device_type) {
165 case DEVICE_TYPE_TUN:
166 packet->data[10] = packet->data[11] = 0;
167 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
168 logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device,
173 case DEVICE_TYPE_TAP:
174 if(write(device_fd, packet->data, packet->len) < 0) {
175 logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device,
184 device_out_packets++;
185 device_out_bytes += packet->len;
190 static void dump_device_stats(void) {
191 logger(DEBUG_ALWAYS, LOG_DEBUG, "Statistics for %s %s:", device_info, device);
192 logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes in: %10"PRIu64, device_in_bytes);
193 logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes out: %10"PRIu64, device_out_bytes);
196 const devops_t os_devops = {
197 .setup = setup_device,
198 .close = close_device,
200 .write = write_packet,
201 .dump_stats = dump_device_stats,