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 along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 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         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  63                 device = xstrdup(DEFAULT_DEVICE);
  64
  65         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  66                 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
  67
  68         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  69                 if(!strcasecmp(type, "tun"))
  70                         /* use default */;
  71 #ifdef HAVE_TUNEMU
  72                 else if(!strcasecmp(type, "tunemu"))
  73                         device_type = DEVICE_TYPE_TUNEMU;
  74 #endif
  75                 else if(!strcasecmp(type, "tunnohead"))
  76                         device_type = DEVICE_TYPE_TUN;
  77                 else if(!strcasecmp(type, "tunifhead"))
  78                         device_type = DEVICE_TYPE_TUNIFHEAD;
  79                 else if(!strcasecmp(type, "tap"))
  80                         device_type = DEVICE_TYPE_TAP;
  81                 else {
  82                         logger(LOG_ERR, _("Unknown device type %s!"), type);
  83                         return false;
  84                 }
  85         } else {
  86                 if(strstr(device, "tap") || routing_mode != RMODE_ROUTER)
  87                         device_type = DEVICE_TYPE_TAP;
  88         }
  89
  90         switch(device_type) {
  91 #ifdef HAVE_TUNEMU
  92                 case DEVICE_TYPE_TUNEMU: {
  93                         char dynamic_name[256] = "";
  94                         device_fd = tunemu_open(dynamic_name);
  95                 }
  96                         break;
  97 #endif
  98                 default:
  99                         device_fd = open(device, O_RDWR | O_NONBLOCK);
 100         }
 101
 102         if(device_fd < 0) {
 103                 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
 104                 return false;
 105         }
 106
 107         switch(device_type) {
 108                 default:
 109                         device_type = DEVICE_TYPE_TUN;
 110                 case DEVICE_TYPE_TUN:
 111 #ifdef TUNSIFHEAD
 112                 {
 113                         const int zero = 0;
 114                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
 115                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 116                                 return false;
 117                         }
 118                 }
 119 #endif
 120 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 121                 {
 122                         const int mode = IFF_BROADCAST | IFF_MULTICAST;
 123                         ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 124                 }
 125 #endif
 126
 127                         device_info = _("Generic BSD tun device");
 128                         break;
 129                 case DEVICE_TYPE_TUNIFHEAD:
 130 #ifdef TUNSIFHEAD
 131                 {
 132                         const int one = 1;
 133                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 134                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 135                                 return false;
 136                         }
 137                 }
 138 #endif
 139 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 140                 {
 141                                 const int mode = IFF_BROADCAST | IFF_MULTICAST;
 142                                 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 143                 }
 144 #endif
 145
 146                         device_info = _("Generic BSD tun device");
 147                         break;
 148                 case DEVICE_TYPE_TAP:
 149                         if(routing_mode == RMODE_ROUTER)
 150                                 overwrite_mac = true;
 151                         device_info = _("Generic BSD tap device");
 152                         break;
 153 #ifdef HAVE_TUNEMU
 154                 case DEVICE_TYPE_TUNEMU:
 155                         device_info = _("BSD tunemu device");
 156                         break;
 157 #endif
 158         }
 159
 160         logger(LOG_INFO, _("%s is a %s"), device, device_info);
 161
 162         return true;
 163 }
 164
 165 void close_device(void) {
 166         switch(device_type) {
 167 #ifdef HAVE_TUNEMU
 168                 case DEVICE_TYPE_TUNEMU:
 169                         tunemu_close(device_fd);
 170                         break;
 171 #endif
 172                 default:
 173                         close(device_fd);
 174         }
 175
 176         free(device);
 177         free(iface);
 178 }
 179
 180 bool read_packet(vpn_packet_t *packet) {
 181         int lenin;
 182
 183         switch(device_type) {
 184                 case DEVICE_TYPE_TUN:
 185 #ifdef HAVE_TUNEMU
 186                 case DEVICE_TYPE_TUNEMU:
 187                         if(device_type == DEVICE_TYPE_TUNEMU)
 188                                 lenin = tunemu_read(device_fd, packet->data + 14, MTU - 14);
 189                         else
 190 #else
 191                                 lenin = read(device_fd, packet->data + 14, MTU - 14);
 192 #endif
 193
 194                         if(lenin <= 0) {
 195                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 196                                            device, strerror(errno));
 197                                 return false;
 198                         }
 199
 200                         switch(packet->data[14] >> 4) {
 201                                 case 4:
 202                                         packet->data[12] = 0x08;
 203                                         packet->data[13] = 0x00;
 204                                         break;
 205                                 case 6:
 206                                         packet->data[12] = 0x86;
 207                                         packet->data[13] = 0xDD;
 208                                         break;
 209                                 default:
 210                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 211                                                            _ ("Unknown IP version %d while reading packet from %s %s"),
 212                                                            packet->data[14] >> 4, device_info, device);
 213                                         return false;
 214                         }
 215
 216                         packet->len = lenin + 14;
 217                         break;
 218
 219                 case DEVICE_TYPE_TUNIFHEAD: {
 220                         u_int32_t type;
 221                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 222
 223                         if((lenin = readv(device_fd, vector, 2)) <= 0) {
 224                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 225                                            device, strerror(errno));
 226                                 return false;
 227                         }
 228
 229                         switch (ntohl(type)) {
 230                                 case AF_INET:
 231                                         packet->data[12] = 0x08;
 232                                         packet->data[13] = 0x00;
 233                                         break;
 234
 235                                 case AF_INET6:
 236                                         packet->data[12] = 0x86;
 237                                         packet->data[13] = 0xDD;
 238                                         break;
 239
 240                                 default:
 241                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 242                                                            _ ("Unknown address family %x while reading packet from %s %s"),
 243                                                            ntohl(type), device_info, device);
 244                                         return false;
 245                         }
 246
 247                         packet->len = lenin + 10;
 248                         break;
 249                 }
 250
 251                 case DEVICE_TYPE_TAP:
 252                         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
 253                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 254                                            device, strerror(errno));
 255                                 return false;
 256                         }
 257
 258                         packet->len = lenin;
 259                         break;
 260
 261                 default:
 262                         return false;
 263         }
 264
 265         device_total_in += packet->len;
 266
 267         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
 268                            packet->len, device_info);
 269
 270         logger(LOG_INFO, "E:fd_read");
 271         return true;
 272 }
 273
 274 bool write_packet(vpn_packet_t *packet) {
 275         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
 276                            packet->len, device_info);
 277
 278         switch(device_type) {
 279                 case DEVICE_TYPE_TUN:
 280                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 281                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 282                                            device, strerror(errno));
 283                                 return false;
 284                         }
 285                         break;
 286
 287                 case DEVICE_TYPE_TUNIFHEAD: {
 288                         u_int32_t type;
 289                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, packet->len - 14}};
 290                         int af;
 291
 292                         af = (packet->data[12] << 8) + packet->data[13];
 293
 294                         switch (af) {
 295                                 case 0x0800:
 296                                         type = htonl(AF_INET);
 297                                         break;
 298                                 case 0x86DD:
 299                                         type = htonl(AF_INET6);
 300                                         break;
 301                                 default:
 302                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 303                                                            _("Unknown address family %x while writing packet to %s %s"),
 304                                                            af, device_info, device);
 305                                         return false;
 306                         }
 307
 308                         if(writev(device_fd, vector, 2) < 0) {
 309                                 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
 310                                            strerror(errno));
 311                                 return false;
 312                         }
 313                         break;
 314                 }
 315
 316                 case DEVICE_TYPE_TAP:
 317                         if(write(device_fd, packet->data, packet->len) < 0) {
 318                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 319                                            device, strerror(errno));
 320                                 return false;
 321                         }
 322                         break;
 323
 324 #ifdef HAVE_TUNEMU
 325                 case DEVICE_TYPE_TUNEMU:
 326                         if(tunemu_write(device_fd, packet->data + 14, packet->len - 14) < 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 #endif
 333
 334                 default:
 335                         return false;
 336         }
 337
 338         device_total_out += packet->len;
 339
 340         return true;
 341 }
 342
 343 void dump_device_stats(void) {
 344         logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
 345         logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
 346         logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
 347 }