www.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                   2001-2009 Guus Sliepen <guus@tinc-vpn.org>
   5
   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.
  10
  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.
  15
  16     You should have received a copy of the GNU General Public License
  17     along with this program; if not, write to the Free Software
  18     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include "conf.h"
  24 #include "logger.h"
  25 #include "net.h"
  26 #include "route.h"
  27 #include "utils.h"
  28 #include "xalloc.h"
  29
  30 #ifdef HAVE_TUNEMU
  31 #include "bsd/tunemu.h"
  32 #endif
  33
  34 #define DEFAULT_DEVICE "/dev/tun0"
  35
  36 typedef enum device_type {
  37         DEVICE_TYPE_TUN,
  38         DEVICE_TYPE_TUNIFHEAD,
  39         DEVICE_TYPE_TAP,
  40 #ifdef HAVE_TUNEMU
  41         DEVICE_TYPE_TUNEMU,
  42 #endif
  43 } device_type_t;
  44
  45 int device_fd = -1;
  46 char *device = NULL;
  47 char *iface = NULL;
  48 static char *device_info = NULL;
  49 static int device_total_in = 0;
  50 static int device_total_out = 0;
  51 #if defined(TUNEMU)
  52 static device_type_t device_type = DEVICE_TYPE_TUNEMU;
  53 #elif defined(HAVE_OPENBSD) || defined(HAVE_FREEBSD)
  54 static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
  55 #else
  56 static device_type_t device_type = DEVICE_TYPE_TUN;
  57 #endif
  58
  59 bool setup_device(void) {
  60         char *type;
  61
  62         cp();
  63
  64         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  65                 device = xstrdup(DEFAULT_DEVICE);
  66
  67         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  68                 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
  69
  70         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  71                 if(!strcasecmp(type, "tun"))
  72                         /* use default */;
  73 #ifdef HAVE_TUNEMU
  74                 else if(!strcasecmp(type, "tunemu"))
  75                         device_type = DEVICE_TYPE_TUNEMU;
  76 #endif
  77                 else if(!strcasecmp(type, "tunnohead"))
  78                         device_type = DEVICE_TYPE_TUN;
  79                 else if(!strcasecmp(type, "tunifhead"))
  80                         device_type = DEVICE_TYPE_TUNIFHEAD;
  81                 else if(!strcasecmp(type, "tap"))
  82                         device_type = DEVICE_TYPE_TAP;
  83                 else {
  84                         logger(LOG_ERR, _("Unknown device type %s!"), type);
  85                         return false;
  86                 }
  87         } else {
  88                 if(strstr(device, "tap") || routing_mode != RMODE_ROUTER)
  89                         device_type = DEVICE_TYPE_TAP;
  90         }
  91
  92         switch(device_type) {
  93 #ifdef HAVE_TUNEMU
  94                 case DEVICE_TYPE_TUNEMU: {
  95                         char dynamic_name[256] = "";
  96                         device_fd = tunemu_open(dynamic_name);
  97                 }
  98                         break;
  99 #endif
 100                 default:
 101                         device_fd = open(device, O_RDWR | O_NONBLOCK);
 102         }
 103
 104         if(device_fd < 0) {
 105                 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
 106                 return false;
 107         }
 108
 109         switch(device_type) {
 110                 default:
 111                         device_type = DEVICE_TYPE_TUN;
 112                 case DEVICE_TYPE_TUN:
 113 #ifdef TUNSIFHEAD
 114                 {
 115                         const int zero = 0;
 116                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
 117                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 118                                 return false;
 119                         }
 120                 }
 121 #endif
 122 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 123                 {
 124                         const int mode = IFF_BROADCAST | IFF_MULTICAST;
 125                         ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 126                 }
 127 #endif
 128
 129                         device_info = _("Generic BSD tun device");
 130                         break;
 131                 case DEVICE_TYPE_TUNIFHEAD:
 132 #ifdef TUNSIFHEAD
 133                 {
 134                         const int one = 1;
 135                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 136                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 137                                 return false;
 138                         }
 139                 }
 140 #endif
 141 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 142                 {
 143                                 const int mode = IFF_BROADCAST | IFF_MULTICAST;
 144                                 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 145                 }
 146 #endif
 147
 148                         device_info = _("Generic BSD tun device");
 149                         break;
 150                 case DEVICE_TYPE_TAP:
 151                         if(routing_mode == RMODE_ROUTER)
 152                                 overwrite_mac = true;
 153                         device_info = _("Generic BSD tap device");
 154                         break;
 155 #ifdef HAVE_TUNEMU
 156                 case DEVICE_TYPE_TUNEMU:
 157                         device_info = _("BSD tunemu device");
 158                         break;
 159 #endif
 160         }
 161
 162         logger(LOG_INFO, _("%s is a %s"), device, device_info);
 163
 164         return true;
 165 }
 166
 167 void close_device(void) {
 168         cp();
 169
 170         switch(device_type) {
 171 #ifdef HAVE_TUNEMU
 172                 case DEVICE_TYPE_TUNEMU:
 173                         tunemu_close(device_fd);
 174                         break;
 175 #endif
 176                 default:
 177                         close(device_fd);
 178         }
 179
 180         free(device);
 181         free(iface);
 182 }
 183
 184 bool read_packet(vpn_packet_t *packet) {
 185         int lenin;
 186
 187         cp();
 188
 189         switch(device_type) {
 190                 case DEVICE_TYPE_TUN:
 191 #ifdef HAVE_TUNEMU
 192                 case DEVICE_TYPE_TUNEMU:
 193                         if(device_type == DEVICE_TYPE_TUNEMU)
 194                                 lenin = tunemu_read(device_fd, packet->data + 14, MTU - 14);
 195                         else
 196 #else
 197                                 lenin = read(device_fd, packet->data + 14, MTU - 14);
 198 #endif
 199
 200                         if(lenin <= 0) {
 201                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 202                                            device, strerror(errno));
 203                                 return false;
 204                         }
 205
 206                         switch(packet->data[14] >> 4) {
 207                                 case 4:
 208                                         packet->data[12] = 0x08;
 209                                         packet->data[13] = 0x00;
 210                                         break;
 211                                 case 6:
 212                                         packet->data[12] = 0x86;
 213                                         packet->data[13] = 0xDD;
 214                                         break;
 215                                 default:
 216                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 217                                                            _ ("Unknown IP version %d while reading packet from %s %s"),
 218                                                            packet->data[14] >> 4, device_info, device);
 219                                         return false;
 220                         }
 221
 222                         packet->len = lenin + 14;
 223                         break;
 224
 225                 case DEVICE_TYPE_TUNIFHEAD: {
 226                         u_int32_t type;
 227                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 228
 229                         if((lenin = readv(device_fd, vector, 2)) <= 0) {
 230                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 231                                            device, strerror(errno));
 232                                 return false;
 233                         }
 234
 235                         switch (ntohl(type)) {
 236                                 case AF_INET:
 237                                         packet->data[12] = 0x08;
 238                                         packet->data[13] = 0x00;
 239                                         break;
 240
 241                                 case AF_INET6:
 242                                         packet->data[12] = 0x86;
 243                                         packet->data[13] = 0xDD;
 244                                         break;
 245
 246                                 default:
 247                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 248                                                            _ ("Unknown address family %x while reading packet from %s %s"),
 249                                                            ntohl(type), device_info, device);
 250                                         return false;
 251                         }
 252
 253                         packet->len = lenin + 10;
 254                         break;
 255                 }
 256
 257                 case DEVICE_TYPE_TAP:
 258                         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
 259                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 260                                            device, strerror(errno));
 261                                 return false;
 262                         }
 263
 264                         packet->len = lenin;
 265                         break;
 266
 267                 default:
 268                         return false;
 269         }
 270
 271         device_total_in += packet->len;
 272
 273         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
 274                            packet->len, device_info);
 275
 276         logger(LOG_INFO, "E:fd_read");
 277         return true;
 278 }
 279
 280 bool write_packet(vpn_packet_t *packet)
 281 {
 282         cp();
 283
 284         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
 285                            packet->len, device_info);
 286
 287         switch(device_type) {
 288                 case DEVICE_TYPE_TUN:
 289                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 290                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 291                                            device, strerror(errno));
 292                                 return false;
 293                         }
 294                         break;
 295
 296                 case DEVICE_TYPE_TUNIFHEAD: {
 297                         u_int32_t type;
 298                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, packet->len - 14}};
 299                         int af;
 300
 301                         af = (packet->data[12] << 8) + packet->data[13];
 302
 303                         switch (af) {
 304                                 case 0x0800:
 305                                         type = htonl(AF_INET);
 306                                         break;
 307                                 case 0x86DD:
 308                                         type = htonl(AF_INET6);
 309                                         break;
 310                                 default:
 311                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 312                                                            _("Unknown address family %x while writing packet to %s %s"),
 313                                                            af, device_info, device);
 314                                         return false;
 315                         }
 316
 317                         if(writev(device_fd, vector, 2) < 0) {
 318                                 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
 319                                            strerror(errno));
 320                                 return false;
 321                         }
 322                         break;
 323                 }
 324
 325                 case DEVICE_TYPE_TAP:
 326                         if(write(device_fd, packet->data, packet->len) < 0) {
 327                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 328                                            device, strerror(errno));
 329                                 return false;
 330                         }
 331                         break;
 332
 333 #ifdef HAVE_TUNEMU
 334                 case DEVICE_TYPE_TUNEMU:
 335                         if(tunemu_write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 336                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 337                                            device, strerror(errno));
 338                                 return false;
 339                         }
 340                         break;
 341 #endif
 342
 343                 default:
 344                         return false;
 345         }
 346
 347         device_total_out += packet->len;
 348
 349         return true;
 350 }
 351
 352 void dump_device_stats(void)
 353 {
 354         cp();
 355
 356         logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
 357         logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
 358         logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
 359 }