src/bsd/device.c

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