2 device.c -- Interaction with Linux ethertap and tun/tap device
3 Copyright (C) 2001-2005 Ivo Timmermans,
4 2001-2013 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.
21 #include "../system.h"
23 #include <linux/if_tun.h>
24 #define DEFAULT_DEVICE "/dev/net/tun"
27 #include "../device.h"
28 #include "../logger.h"
33 #include "../xalloc.h"
34 #include "../device.h"
36 typedef enum device_type_t {
42 static device_type_t device_type;
45 static char *type = NULL;
46 static char ifrname[IFNAMSIZ];
47 static char *device_info;
49 static bool setup_device(void) {
50 if(!get_config_string(lookup_config(config_tree, "Device"), &device))
51 device = xstrdup(DEFAULT_DEVICE);
53 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
55 iface = xstrdup(netname);
57 device_fd = open(device, O_RDWR | O_NONBLOCK);
60 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open %s: %s", device, strerror(errno));
65 fcntl(device_fd, F_SETFD, FD_CLOEXEC);
68 struct ifreq ifr = {{{0}}};
70 get_config_string(lookup_config(config_tree, "DeviceType"), &type);
72 if(type && strcasecmp(type, "tun") && strcasecmp(type, "tap")) {
73 logger(DEBUG_ALWAYS, LOG_ERR, "Unknown device type %s!", type);
77 if((type && !strcasecmp(type, "tun")) || (!type && routing_mode == RMODE_ROUTER)) {
78 ifr.ifr_flags = IFF_TUN;
79 device_type = DEVICE_TYPE_TUN;
80 device_info = "Linux tun/tap device (tun mode)";
82 if (routing_mode == RMODE_ROUTER)
84 ifr.ifr_flags = IFF_TAP | IFF_NO_PI;
85 device_type = DEVICE_TYPE_TAP;
86 device_info = "Linux tun/tap device (tap mode)";
90 /* Set IFF_ONE_QUEUE flag... */
93 if(get_config_bool(lookup_config(config_tree, "IffOneQueue"), &t1q) && t1q)
94 ifr.ifr_flags |= IFF_ONE_QUEUE;
98 strncpy(ifr.ifr_name, iface, IFNAMSIZ);
100 if(!ioctl(device_fd, TUNSETIFF, &ifr)) {
101 strncpy(ifrname, ifr.ifr_name, IFNAMSIZ);
103 iface = xstrdup(ifrname);
106 logger(DEBUG_ALWAYS, LOG_INFO, "%s is a %s", device, device_info);
111 static void close_device(void) {
119 static bool read_packet(vpn_packet_t *packet) {
122 switch(device_type) {
123 case DEVICE_TYPE_TUN:
124 inlen = read(device_fd, packet->data + 10, MTU - 10);
127 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s",
128 device_info, device, strerror(errno));
132 memset(packet->data, 0, 12);
133 packet->len = inlen + 10;
135 case DEVICE_TYPE_TAP:
136 inlen = read(device_fd, packet->data, MTU);
139 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s",
140 device_info, device, strerror(errno));
150 logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from %s", packet->len,
156 static bool write_packet(vpn_packet_t *packet) {
157 logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
158 packet->len, device_info);
160 switch(device_type) {
161 case DEVICE_TYPE_TUN:
162 packet->data[10] = packet->data[11] = 0;
163 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
164 logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device,
169 case DEVICE_TYPE_TAP:
170 if(write(device_fd, packet->data, packet->len) < 0) {
171 logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device,
183 const devops_t os_devops = {
184 .setup = setup_device,
185 .close = close_device,
187 .write = write_packet,