2 device.c -- Interaction BSD tun/tap device
3 Copyright (C) 2001-2005 Ivo Timmermans,
4 2001-2016 Guus Sliepen <guus@tinc-vpn.org>
5 2009 Grzegorz Dymarek <gregd72002@googlemail.com>
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License along
18 with this program; if not, write to the Free Software Foundation, Inc.,
19 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
22 #include "../system.h"
25 #include "../device.h"
26 #include "../logger.h"
30 #include "../xalloc.h"
36 #ifdef HAVE_NET_IF_UTUN_H
37 #include <sys/sys_domain.h>
38 #include <sys/kern_control.h>
39 #include <net/if_utun.h>
42 #define DEFAULT_TUN_DEVICE "/dev/tun0"
43 #define DEFAULT_TAP_DEVICE "/dev/tap0"
45 typedef enum device_type {
47 DEVICE_TYPE_TUNIFHEAD,
58 static char *device_info = NULL;
59 static uint64_t device_total_in = 0;
60 static uint64_t device_total_out = 0;
61 #if defined(ENABLE_TUNEMU)
62 static device_type_t device_type = DEVICE_TYPE_TUNEMU;
63 #elif defined(HAVE_OPENBSD) || defined(HAVE_FREEBSD) || defined(HAVE_DRAGONFLY)
64 static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
66 static device_type_t device_type = DEVICE_TYPE_TUN;
69 #ifdef HAVE_NET_IF_UTUN_H
70 static bool setup_utun(void) {
71 device_fd = socket(PF_SYSTEM, SOCK_DGRAM, SYSPROTO_CONTROL);
73 logger(LOG_ERR, "Could not open PF_SYSTEM socket: %s\n", strerror(errno));
77 struct ctl_info info = {};
78 strlcpy(info.ctl_name, UTUN_CONTROL_NAME, sizeof info.ctl_name);
80 if(ioctl(device_fd, CTLIOCGINFO, &info) == -1) {
81 logger(LOG_ERR, "ioctl(CTLIOCGINFO) failed: %s", strerror(errno));
86 char *p = strstr(device, "utun"), *e = NULL;
88 unit = strtol(p + 4, &e, 10);
93 struct sockaddr_ctl sc = {
96 .sc_family = AF_SYSTEM,
97 .ss_sysaddr = AF_SYS_CONTROL,
101 if(connect(device_fd, (struct sockaddr *)&sc, sizeof(sc)) == -1) {
102 logger(LOG_ERR, "Could not connect utun socket: %s\n", strerror(errno));
107 socklen_t len = sizeof name;
108 if(getsockopt(device_fd, SYSPROTO_CONTROL, UTUN_OPT_IFNAME, name, &len)) {
109 iface = xstrdup(device);
111 iface = xstrdup(name);
114 device_info = "OS X utun device";
116 logger(LOG_INFO, "%s is a %s", device, device_info);
122 static bool setup_device(void) {
123 // Find out which device file to open
125 if(!get_config_string(lookup_config(config_tree, "Device"), &device)) {
126 if(routing_mode == RMODE_ROUTER)
127 device = xstrdup(DEFAULT_TUN_DEVICE);
129 device = xstrdup(DEFAULT_TAP_DEVICE);
132 // Find out if it's supposed to be a tun or a tap device
136 if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
137 if(!strcasecmp(type, "tun"))
140 else if(!strcasecmp(type, "tunemu"))
141 device_type = DEVICE_TYPE_TUNEMU;
143 #ifdef HAVE_NET_IF_UTUN_H
144 else if(!strcasecmp(type, "utun"))
145 device_type = DEVICE_TYPE_UTUN;
147 else if(!strcasecmp(type, "tunnohead"))
148 device_type = DEVICE_TYPE_TUN;
149 else if(!strcasecmp(type, "tunifhead"))
150 device_type = DEVICE_TYPE_TUNIFHEAD;
151 else if(!strcasecmp(type, "tap"))
152 device_type = DEVICE_TYPE_TAP;
154 logger(LOG_ERR, "Unknown device type %s!", type);
158 #ifdef HAVE_NET_IF_UTUN_H
159 if(strncmp(device, "utun", 4) == 0 || strncmp(device, "/dev/utun", 9) == 0)
160 device_type = DEVICE_TYPE_UTUN;
163 if(strstr(device, "tap") || routing_mode != RMODE_ROUTER)
164 device_type = DEVICE_TYPE_TAP;
167 if(routing_mode == RMODE_SWITCH && device_type != DEVICE_TYPE_TAP) {
168 logger(LOG_ERR, "Only tap devices support switch mode!");
174 switch(device_type) {
176 case DEVICE_TYPE_TUNEMU: {
177 char dynamic_name[256] = "";
178 device_fd = tunemu_open(dynamic_name);
182 #ifdef HAVE_NET_IF_UTUN_H
183 case DEVICE_TYPE_UTUN:
187 device_fd = open(device, O_RDWR | O_NONBLOCK);
191 logger(LOG_ERR, "Could not open %s: %s", device, strerror(errno));
196 fcntl(device_fd, F_SETFD, FD_CLOEXEC);
199 // Guess what the corresponding interface is called
201 char *realname = NULL;
203 #if defined(HAVE_FDEVNAME)
204 realname = fdevname(device_fd);
205 #elif defined(HAVE_DEVNAME)
207 if(!fstat(device_fd, &buf))
208 realname = devname(buf.st_rdev, S_IFCHR);
214 if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
215 iface = xstrdup(strrchr(realname, '/') ? strrchr(realname, '/') + 1 : realname);
216 else if(strcmp(iface, strrchr(realname, '/') ? strrchr(realname, '/') + 1 : realname))
217 logger(LOG_WARNING, "Warning: Interface does not match Device. $INTERFACE might be set incorrectly.");
219 // Configure the device as best as we can
221 switch(device_type) {
223 device_type = DEVICE_TYPE_TUN;
224 case DEVICE_TYPE_TUN:
228 if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
229 logger(LOG_ERR, "System call `%s' failed: %s", "ioctl", strerror(errno));
234 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
236 const int mode = IFF_BROADCAST | IFF_MULTICAST;
237 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
241 device_info = "Generic BSD tun device";
243 case DEVICE_TYPE_TUNIFHEAD:
247 if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
248 logger(LOG_ERR, "System call `%s' failed: %s", "ioctl", strerror(errno));
253 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
255 const int mode = IFF_BROADCAST | IFF_MULTICAST;
256 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
260 device_info = "Generic BSD tun device";
262 case DEVICE_TYPE_TAP:
263 if(routing_mode == RMODE_ROUTER)
264 overwrite_mac = true;
265 device_info = "Generic BSD tap device";
269 if(ioctl(device_fd, TAPGIFNAME, (void*)&ifr) == 0) {
272 iface = xstrdup(ifr.ifr_name);
279 case DEVICE_TYPE_TUNEMU:
280 device_info = "BSD tunemu device";
287 ioctl(device_fd, SIOCGIFADDR, mymac.x);
290 logger(LOG_INFO, "%s is a %s", device, device_info);
295 static void close_device(void) {
296 switch(device_type) {
298 case DEVICE_TYPE_TUNEMU:
299 tunemu_close(device_fd);
310 static bool read_packet(vpn_packet_t *packet) {
313 switch(device_type) {
314 case DEVICE_TYPE_TUN:
316 case DEVICE_TYPE_TUNEMU:
317 if(device_type == DEVICE_TYPE_TUNEMU)
318 lenin = tunemu_read(device_fd, packet->data + 14, MTU - 14);
321 lenin = read(device_fd, packet->data + 14, MTU - 14);
324 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
325 device, strerror(errno));
329 switch(packet->data[14] >> 4) {
331 packet->data[12] = 0x08;
332 packet->data[13] = 0x00;
335 packet->data[12] = 0x86;
336 packet->data[13] = 0xDD;
339 ifdebug(TRAFFIC) logger(LOG_ERR,
340 "Unknown IP version %d while reading packet from %s %s",
341 packet->data[14] >> 4, device_info, device);
345 memset(packet->data, 0, 12);
346 packet->len = lenin + 14;
349 case DEVICE_TYPE_UTUN:
350 case DEVICE_TYPE_TUNIFHEAD: {
351 if((lenin = read(device_fd, packet->data + 10, MTU - 10)) <= 0) {
352 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
353 device, strerror(errno));
357 switch(packet->data[14] >> 4) {
359 packet->data[12] = 0x08;
360 packet->data[13] = 0x00;
363 packet->data[12] = 0x86;
364 packet->data[13] = 0xDD;
367 ifdebug(TRAFFIC) logger(LOG_ERR,
368 "Unknown IP version %d while reading packet from %s %s",
369 packet->data[14] >> 4, device_info, device);
373 memset(packet->data, 0, 12);
374 packet->len = lenin + 10;
378 case DEVICE_TYPE_TAP:
379 if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
380 logger(LOG_ERR, "Error while reading from %s %s: %s", device_info,
381 device, strerror(errno));
392 device_total_in += packet->len;
394 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Read packet of %d bytes from %s",
395 packet->len, device_info);
400 static bool write_packet(vpn_packet_t *packet) {
401 ifdebug(TRAFFIC) logger(LOG_DEBUG, "Writing packet of %d bytes to %s",
402 packet->len, device_info);
404 switch(device_type) {
405 case DEVICE_TYPE_TUN:
406 if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
407 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info,
408 device, strerror(errno));
413 case DEVICE_TYPE_UTUN:
414 case DEVICE_TYPE_TUNIFHEAD: {
415 int af = (packet->data[12] << 8) + packet->data[13];
420 type = htonl(AF_INET);
423 type = htonl(AF_INET6);
426 ifdebug(TRAFFIC) logger(LOG_ERR,
427 "Unknown address family %x while writing packet to %s %s",
428 af, device_info, device);
432 memcpy(packet->data + 10, &type, sizeof type);
434 if(write(device_fd, packet->data + 10, packet->len - 10) < 0) {
435 logger(LOG_ERR, "Can't write to %s %s: %s", device_info, device,
442 case DEVICE_TYPE_TAP:
443 if(write(device_fd, packet->data, packet->len) < 0) {
444 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info,
445 device, strerror(errno));
451 case DEVICE_TYPE_TUNEMU:
452 if(tunemu_write(device_fd, packet->data + 14, packet->len - 14) < 0) {
453 logger(LOG_ERR, "Error while writing to %s %s: %s", device_info,
454 device, strerror(errno));
464 device_total_out += packet->len;
469 static void dump_device_stats(void) {
470 logger(LOG_DEBUG, "Statistics for %s %s:", device_info, device);
471 logger(LOG_DEBUG, " total bytes in: %10"PRIu64, device_total_in);
472 logger(LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
475 const devops_t os_devops = {
476 .setup = setup_device,
477 .close = close_device,
479 .write = write_packet,
480 .dump_stats = dump_device_stats,