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     $Id: device.c 1398 2004-11-01 15:18:53Z guus $
  21 */
  22
  23 #include "system.h"
  24
  25 #include "conf.h"
  26 #include "logger.h"
  27 #include "net.h"
  28 #include "route.h"
  29 #include "utils.h"
  30 #include "xalloc.h"
  31
  32 #ifdef HAVE_TUNEMU
  33 #include "bsd/tunemu.h"
  34 #endif
  35
  36 #define DEFAULT_DEVICE "/dev/tun0"
  37
  38 typedef enum device_type {
  39         DEVICE_TYPE_TUN,
  40         DEVICE_TYPE_TUNIFHEAD,
  41         DEVICE_TYPE_TAP,
  42 #ifdef HAVE_TUNEMU
  43         DEVICE_TYPE_TUNEMU,
  44 #endif
  45 } device_type_t;
  46
  47 int device_fd = -1;
  48 char *device = NULL;
  49 char *iface = NULL;
  50 static char *device_info = NULL;
  51 static int device_total_in = 0;
  52 static int device_total_out = 0;
  53 #if defined(TUNEMU)
  54 static device_type_t device_type = DEVICE_TYPE_TUNEMU;
  55 #elif defined(HAVE_OPENBSD) || defined(HAVE_FREEBSD)
  56 static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
  57 #else
  58 static device_type_t device_type = DEVICE_TYPE_TUN;
  59 #endif
  60
  61 bool setup_device(void) {
  62         char *type;
  63
  64         cp();
  65
  66         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  67                 device = xstrdup(DEFAULT_DEVICE);
  68
  69         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  70                 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
  71
  72         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  73                 if(!strcasecmp(type, "tun"))
  74                         /* use default */;
  75 #ifdef HAVE_TUNEMU
  76                 else if(!strcasecmp(type, "tunemu"))
  77                         device_type = DEVICE_TYPE_TUNEMU;
  78 #endif
  79                 else if(!strcasecmp(type, "tunnohead"))
  80                         device_type = DEVICE_TYPE_TUN;
  81                 else if(!strcasecmp(type, "tunifhead"))
  82                         device_type = DEVICE_TYPE_TUNIFHEAD;
  83                 else if(!strcasecmp(type, "tap"))
  84                         device_type = DEVICE_TYPE_TAP;
  85                 else {
  86                         logger(LOG_ERR, _("Unknown device type %s!"), type);
  87                         return false;
  88                 }
  89         } else {
  90                 if(strstr(device, "tap") || routing_mode != RMODE_ROUTER)
  91                         device_type = DEVICE_TYPE_TAP;
  92         }
  93
  94         switch(device_type) {
  95 #ifdef HAVE_TUNEMU
  96                 case DEVICE_TYPE_TUNEMU: {
  97                         char dynamic_name[256] = "";
  98                         device_fd = tunemu_open(dynamic_name);
  99                 }
 100                         break;
 101 #endif
 102                 default:
 103                         device_fd = open(device, O_RDWR | O_NONBLOCK);
 104         }
 105
 106         if(device_fd < 0) {
 107                 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
 108                 return false;
 109         }
 110
 111         switch(device_type) {
 112                 default:
 113                         device_type = DEVICE_TYPE_TUN;
 114                 case DEVICE_TYPE_TUN:
 115 #ifdef TUNSIFHEAD
 116                 {
 117                         const int zero = 0;
 118                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
 119                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 120                                 return false;
 121                         }
 122                 }
 123 #endif
 124 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 125                 {
 126                         const int mode = IFF_BROADCAST | IFF_MULTICAST;
 127                         ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 128                 }
 129 #endif
 130
 131                         device_info = _("Generic BSD tun device");
 132                         break;
 133                 case DEVICE_TYPE_TUNIFHEAD:
 134 #ifdef TUNSIFHEAD
 135                 {
 136                         const int one = 1;
 137                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 138                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 139                                 return false;
 140                         }
 141                 }
 142 #endif
 143 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 144                 {
 145                                 const int mode = IFF_BROADCAST | IFF_MULTICAST;
 146                                 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 147                 }
 148 #endif
 149
 150                         device_info = _("Generic BSD tun device");
 151                         break;
 152                 case DEVICE_TYPE_TAP:
 153                         if(routing_mode == RMODE_ROUTER)
 154                                 overwrite_mac = true;
 155                         device_info = _("Generic BSD tap device");
 156                         break;
 157 #ifdef HAVE_TUNEMU
 158                 case DEVICE_TYPE_TUNEMU:
 159                         device_info = _("BSD tunemu device");
 160                         break;
 161 #endif
 162         }
 163
 164         logger(LOG_INFO, _("%s is a %s"), device, device_info);
 165
 166         return true;
 167 }
 168
 169 void close_device(void) {
 170         cp();
 171
 172         switch(device_type) {
 173 #ifdef HAVE_TUNEMU
 174                 case DEVICE_TYPE_TUNEMU:
 175                         tunemu_close(device_fd);
 176                         break;
 177 #endif
 178                 default:
 179                         close(device_fd);
 180         }
 181
 182         free(device);
 183         free(iface);
 184 }
 185
 186 bool read_packet(vpn_packet_t *packet) {
 187         int lenin;
 188
 189         cp();
 190
 191         switch(device_type) {
 192                 case DEVICE_TYPE_TUN:
 193 #ifdef HAVE_TUNEMU
 194                 case DEVICE_TYPE_TUNEMU:
 195                         if(device_type == DEVICE_TYPE_TUNEMU)
 196                                 lenin = tunemu_read(device_fd, packet->data + 14, MTU - 14);
 197                         else
 198 #else
 199                                 lenin = read(device_fd, packet->data + 14, MTU - 14);
 200 #endif
 201
 202                         if(lenin <= 0) {
 203                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 204                                            device, strerror(errno));
 205                                 return false;
 206                         }
 207
 208                         switch(packet->data[14] >> 4) {
 209                                 case 4:
 210                                         packet->data[12] = 0x08;
 211                                         packet->data[13] = 0x00;
 212                                         break;
 213                                 case 6:
 214                                         packet->data[12] = 0x86;
 215                                         packet->data[13] = 0xDD;
 216                                         break;
 217                                 default:
 218                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 219                                                            _ ("Unknown IP version %d while reading packet from %s %s"),
 220                                                            packet->data[14] >> 4, device_info, device);
 221                                         return false;
 222                         }
 223
 224                         packet->len = lenin + 14;
 225                         break;
 226
 227                 case DEVICE_TYPE_TUNIFHEAD: {
 228                         u_int32_t type;
 229                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 230
 231                         if((lenin = readv(device_fd, vector, 2)) <= 0) {
 232                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 233                                            device, strerror(errno));
 234                                 return false;
 235                         }
 236
 237                         switch (ntohl(type)) {
 238                                 case AF_INET:
 239                                         packet->data[12] = 0x08;
 240                                         packet->data[13] = 0x00;
 241                                         break;
 242
 243                                 case AF_INET6:
 244                                         packet->data[12] = 0x86;
 245                                         packet->data[13] = 0xDD;
 246                                         break;
 247
 248                                 default:
 249                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 250                                                            _ ("Unknown address family %x while reading packet from %s %s"),
 251                                                            ntohl(type), device_info, device);
 252                                         return false;
 253                         }
 254
 255                         packet->len = lenin + 10;
 256                         break;
 257                 }
 258
 259                 case DEVICE_TYPE_TAP:
 260                         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
 261                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 262                                            device, strerror(errno));
 263                                 return false;
 264                         }
 265
 266                         packet->len = lenin;
 267                         break;
 268
 269                 default:
 270                         return false;
 271         }
 272
 273         device_total_in += packet->len;
 274
 275         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
 276                            packet->len, device_info);
 277
 278         logger(LOG_INFO, "E:fd_read");
 279         return true;
 280 }
 281
 282 bool write_packet(vpn_packet_t *packet)
 283 {
 284         cp();
 285
 286         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
 287                            packet->len, device_info);
 288
 289         switch(device_type) {
 290                 case DEVICE_TYPE_TUN:
 291                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 292                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 293                                            device, strerror(errno));
 294                                 return false;
 295                         }
 296                         break;
 297
 298                 case DEVICE_TYPE_TUNIFHEAD: {
 299                         u_int32_t type;
 300                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, packet->len - 14}};
 301                         int af;
 302
 303                         af = (packet->data[12] << 8) + packet->data[13];
 304
 305                         switch (af) {
 306                                 case 0x0800:
 307                                         type = htonl(AF_INET);
 308                                         break;
 309                                 case 0x86DD:
 310                                         type = htonl(AF_INET6);
 311                                         break;
 312                                 default:
 313                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 314                                                            _("Unknown address family %x while writing packet to %s %s"),
 315                                                            af, device_info, device);
 316                                         return false;
 317                         }
 318
 319                         if(writev(device_fd, vector, 2) < 0) {
 320                                 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
 321                                            strerror(errno));
 322                                 return false;
 323                         }
 324                         break;
 325                 }
 326
 327                 case DEVICE_TYPE_TAP:
 328                         if(write(device_fd, packet->data, packet->len) < 0) {
 329                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 330                                            device, strerror(errno));
 331                                 return false;
 332                         }
 333                         break;
 334
 335 #ifdef HAVE_TUNEMU
 336                 case DEVICE_TYPE_TUNEMU:
 337                         if(tunemu_write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 338                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 339                                            device, strerror(errno));
 340                                 return false;
 341                         }
 342                         break;
 343 #endif
 344
 345                 default:
 346                         return false;
 347         }
 348
 349         device_total_out += packet->len;
 350
 351         return true;
 352 }
 353
 354 void dump_device_stats(void)
 355 {
 356         cp();
 357
 358         logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
 359         logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
 360         logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
 361 }