tinc-vpn.org Git - tinc/blob - src/bsd/device.c

   1 /*
   2     device.c -- Interaction BSD tun/tap device
   3     Copyright (C) 2001-2005 Ivo Timmermans,
   4                   2001-2013 Guus Sliepen <guus@tinc-vpn.org>
   5                   2009      Grzegorz Dymarek <gregd72002@googlemail.com>
   6
   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.
  11
  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.
  16
  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.
  20 */
  21
  22 #include "system.h"
  23
  24 #include "conf.h"
  25 #include "device.h"
  26 #include "logger.h"
  27 #include "names.h"
  28 #include "net.h"
  29 #include "route.h"
  30 #include "utils.h"
  31 #include "xalloc.h"
  32
  33 #ifdef ENABLE_TUNEMU
  34 #include "bsd/tunemu.h"
  35 #endif
  36
  37 #define DEFAULT_TUN_DEVICE "/dev/tun0"
  38 #if defined(HAVE_FREEBSD) || defined(HAVE_NETBSD)
  39 #define DEFAULT_TAP_DEVICE "/dev/tap0"
  40 #else
  41 #define DEFAULT_TAP_DEVICE "/dev/tun0"
  42 #endif
  43
  44 typedef enum device_type {
  45         DEVICE_TYPE_TUN,
  46         DEVICE_TYPE_TUNIFHEAD,
  47         DEVICE_TYPE_TAP,
  48 #ifdef ENABLE_TUNEMU
  49         DEVICE_TYPE_TUNEMU,
  50 #endif
  51 } device_type_t;
  52
  53 int device_fd = -1;
  54 char *device = NULL;
  55 char *iface = NULL;
  56 static char *device_info = NULL;
  57 static uint64_t device_total_in = 0;
  58 static uint64_t device_total_out = 0;
  59 #if defined(ENABLE_TUNEMU)
  60 static device_type_t device_type = DEVICE_TYPE_TUNEMU;
  61 #elif defined(HAVE_OPENBSD) || defined(HAVE_FREEBSD) || defined(HAVE_DRAGONFLY)
  62 static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
  63 #else
  64 static device_type_t device_type = DEVICE_TYPE_TUN;
  65 #endif
  66
  67 static bool setup_device(void) {
  68         char *type;
  69
  70         if(!get_config_string(lookup_config(config_tree, "Device"), &device)) {
  71                 if(routing_mode == RMODE_ROUTER)
  72                         device = xstrdup(DEFAULT_TUN_DEVICE);
  73                 else
  74                         device = xstrdup(DEFAULT_TAP_DEVICE);
  75         }
  76
  77         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  78                 iface = xstrdup(strrchr(device, '/') ? strrchr(device, '/') + 1 : device);
  79
  80         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  81                 if(!strcasecmp(type, "tun"))
  82                         /* use default */;
  83 #ifdef ENABLE_TUNEMU
  84                 else if(!strcasecmp(type, "tunemu"))
  85                         device_type = DEVICE_TYPE_TUNEMU;
  86 #endif
  87                 else if(!strcasecmp(type, "tunnohead"))
  88                         device_type = DEVICE_TYPE_TUN;
  89                 else if(!strcasecmp(type, "tunifhead"))
  90                         device_type = DEVICE_TYPE_TUNIFHEAD;
  91                 else if(!strcasecmp(type, "tap"))
  92                         device_type = DEVICE_TYPE_TAP;
  93                 else {
  94                         logger(DEBUG_ALWAYS, LOG_ERR, "Unknown device type %s!", type);
  95                         return false;
  96                 }
  97         } else {
  98                 if(strstr(device, "tap") || routing_mode != RMODE_ROUTER)
  99                         device_type = DEVICE_TYPE_TAP;
 100         }
 101
 102         switch(device_type) {
 103 #ifdef ENABLE_TUNEMU
 104                 case DEVICE_TYPE_TUNEMU: {
 105                         char dynamic_name[256] = "";
 106                         device_fd = tunemu_open(dynamic_name);
 107                 }
 108                         break;
 109 #endif
 110                 default:
 111                         device_fd = open(device, O_RDWR | O_NONBLOCK);
 112         }
 113
 114         if(device_fd < 0) {
 115                 logger(DEBUG_ALWAYS, LOG_ERR, "Could not open %s: %s", device, strerror(errno));
 116                 return false;
 117         }
 118
 119 #ifdef FD_CLOEXEC
 120         fcntl(device_fd, F_SETFD, FD_CLOEXEC);
 121 #endif
 122
 123         switch(device_type) {
 124                 default:
 125                         device_type = DEVICE_TYPE_TUN;
 126                 case DEVICE_TYPE_TUN:
 127 #ifdef TUNSIFHEAD
 128                 {
 129                         const int zero = 0;
 130                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
 131                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "ioctl", strerror(errno));
 132                                 return false;
 133                         }
 134                 }
 135 #endif
 136 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 137                 {
 138                         const int mode = IFF_BROADCAST | IFF_MULTICAST;
 139                         ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 140                 }
 141 #endif
 142
 143                         device_info = "Generic BSD tun device";
 144                         break;
 145                 case DEVICE_TYPE_TUNIFHEAD:
 146 #ifdef TUNSIFHEAD
 147                 {
 148                         const int one = 1;
 149                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 150                                 logger(DEBUG_ALWAYS, LOG_ERR, "System call `%s' failed: %s", "ioctl", strerror(errno));
 151                                 return false;
 152                         }
 153                 }
 154 #endif
 155 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 156                 {
 157                                 const int mode = IFF_BROADCAST | IFF_MULTICAST;
 158                                 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 159                 }
 160 #endif
 161
 162                         device_info = "Generic BSD tun device";
 163                         break;
 164                 case DEVICE_TYPE_TAP:
 165                         if(routing_mode == RMODE_ROUTER)
 166                                 overwrite_mac = true;
 167                         device_info = "Generic BSD tap device";
 168 #ifdef TAPGIFNAME
 169                         {
 170                                 struct ifreq ifr;
 171                                 if(ioctl(device_fd, TAPGIFNAME, (void*)&ifr) == 0) {
 172                                         if(iface)
 173                                                 free(iface);
 174                                         iface = xstrdup(ifr.ifr_name);
 175                                 }
 176                         }
 177
 178 #endif
 179                         break;
 180 #ifdef ENABLE_TUNEMU
 181                 case DEVICE_TYPE_TUNEMU:
 182                         device_info = "BSD tunemu device";
 183                         break;
 184 #endif
 185         }
 186
 187         logger(DEBUG_ALWAYS, LOG_INFO, "%s is a %s", device, device_info);
 188
 189         return true;
 190 }
 191
 192 static void close_device(void) {
 193         switch(device_type) {
 194 #ifdef ENABLE_TUNEMU
 195                 case DEVICE_TYPE_TUNEMU:
 196                         tunemu_close(device_fd);
 197                         break;
 198 #endif
 199                 default:
 200                         close(device_fd);
 201         }
 202
 203         free(device);
 204         free(iface);
 205 }
 206
 207 static bool read_packet(vpn_packet_t *packet) {
 208         int inlen;
 209
 210         switch(device_type) {
 211                 case DEVICE_TYPE_TUN:
 212 #ifdef ENABLE_TUNEMU
 213                 case DEVICE_TYPE_TUNEMU:
 214                         if(device_type == DEVICE_TYPE_TUNEMU)
 215                                 inlen = tunemu_read(device_fd, packet->data + 14, MTU - 14);
 216                         else
 217 #endif
 218                                 inlen = read(device_fd, packet->data + 14, MTU - 14);
 219
 220                         if(inlen <= 0) {
 221                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
 222                                            device, strerror(errno));
 223                                 return false;
 224                         }
 225
 226                         switch(packet->data[14] >> 4) {
 227                                 case 4:
 228                                         packet->data[12] = 0x08;
 229                                         packet->data[13] = 0x00;
 230                                         break;
 231                                 case 6:
 232                                         packet->data[12] = 0x86;
 233                                         packet->data[13] = 0xDD;
 234                                         break;
 235                                 default:
 236                                         logger(DEBUG_TRAFFIC, LOG_ERR,
 237                                                            "Unknown IP version %d while reading packet from %s %s",
 238                                                            packet->data[14] >> 4, device_info, device);
 239                                         return false;
 240                         }
 241
 242                         memset(packet->data, 0, 12);
 243                         packet->len = inlen + 14;
 244                         break;
 245
 246                 case DEVICE_TYPE_TUNIFHEAD: {
 247                         u_int32_t type;
 248                         struct iovec vector[2] = {{&type, sizeof type}, {packet->data + 14, MTU - 14}};
 249
 250                         if((inlen = readv(device_fd, vector, 2)) <= 0) {
 251                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
 252                                            device, strerror(errno));
 253                                 return false;
 254                         }
 255
 256                         switch (ntohl(type)) {
 257                                 case AF_INET:
 258                                         packet->data[12] = 0x08;
 259                                         packet->data[13] = 0x00;
 260                                         break;
 261
 262                                 case AF_INET6:
 263                                         packet->data[12] = 0x86;
 264                                         packet->data[13] = 0xDD;
 265                                         break;
 266
 267                                 default:
 268                                         logger(DEBUG_TRAFFIC, LOG_ERR,
 269                                                            "Unknown address family %x while reading packet from %s %s",
 270                                                            ntohl(type), device_info, device);
 271                                         return false;
 272                         }
 273
 274                         memset(packet->data, 0, 12);
 275                         packet->len = inlen + 10;
 276                         break;
 277                 }
 278
 279                 case DEVICE_TYPE_TAP:
 280                         if((inlen = read(device_fd, packet->data, MTU)) <= 0) {
 281                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while reading from %s %s: %s", device_info,
 282                                            device, strerror(errno));
 283                                 return false;
 284                         }
 285
 286                         packet->len = inlen;
 287                         break;
 288
 289                 default:
 290                         return false;
 291         }
 292
 293         device_total_in += packet->len;
 294
 295         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Read packet of %d bytes from %s",
 296                            packet->len, device_info);
 297
 298         return true;
 299 }
 300
 301 static bool write_packet(vpn_packet_t *packet) {
 302         logger(DEBUG_TRAFFIC, LOG_DEBUG, "Writing packet of %d bytes to %s",
 303                            packet->len, device_info);
 304
 305         switch(device_type) {
 306                 case DEVICE_TYPE_TUN:
 307                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 308                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info,
 309                                            device, strerror(errno));
 310                                 return false;
 311                         }
 312                         break;
 313
 314                 case DEVICE_TYPE_TUNIFHEAD: {
 315                         u_int32_t type;
 316                         struct iovec vector[2] = {{&type, sizeof type}, {packet->data + 14, packet->len - 14}};
 317                         int af;
 318
 319                         af = (packet->data[12] << 8) + packet->data[13];
 320
 321                         switch (af) {
 322                                 case 0x0800:
 323                                         type = htonl(AF_INET);
 324                                         break;
 325                                 case 0x86DD:
 326                                         type = htonl(AF_INET6);
 327                                         break;
 328                                 default:
 329                                         logger(DEBUG_TRAFFIC, LOG_ERR,
 330                                                            "Unknown address family %x while writing packet to %s %s",
 331                                                            af, device_info, device);
 332                                         return false;
 333                         }
 334
 335                         if(writev(device_fd, vector, 2) < 0) {
 336                                 logger(DEBUG_ALWAYS, LOG_ERR, "Can't write to %s %s: %s", device_info, device,
 337                                            strerror(errno));
 338                                 return false;
 339                         }
 340                         break;
 341                 }
 342
 343                 case DEVICE_TYPE_TAP:
 344                         if(write(device_fd, packet->data, packet->len) < 0) {
 345                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info,
 346                                            device, strerror(errno));
 347                                 return false;
 348                         }
 349                         break;
 350
 351 #ifdef ENABLE_TUNEMU
 352                 case DEVICE_TYPE_TUNEMU:
 353                         if(tunemu_write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 354                                 logger(DEBUG_ALWAYS, LOG_ERR, "Error while writing to %s %s: %s", device_info,
 355                                            device, strerror(errno));
 356                                 return false;
 357                         }
 358                         break;
 359 #endif
 360
 361                 default:
 362                         return false;
 363         }
 364
 365         device_total_out += packet->len;
 366
 367         return true;
 368 }
 369
 370 static void dump_device_stats(void) {
 371         logger(DEBUG_ALWAYS, LOG_DEBUG, "Statistics for %s %s:", device_info, device);
 372         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes in:  %10"PRIu64, device_total_in);
 373         logger(DEBUG_ALWAYS, LOG_DEBUG, " total bytes out: %10"PRIu64, device_total_out);
 374 }
 375
 376 const devops_t os_devops = {
 377         .setup = setup_device,
 378         .close = close_device,
 379         .read = read_packet,
 380         .write = write_packet,
 381         .dump_stats = dump_device_stats,
 382 };