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                   2001-2007 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
  31 #define DEFAULT_DEVICE "/dev/tun0"
  32
  33 typedef enum device_type {
  34         DEVICE_TYPE_TUN,
  35         DEVICE_TYPE_TUNIFHEAD,
  36         DEVICE_TYPE_TAP,
  37 } device_type_t;
  38
  39 int device_fd = -1;
  40 char *device;
  41 char *iface;
  42 char *device_info;
  43 static int device_total_in = 0;
  44 static int device_total_out = 0;
  45 #ifdef HAVE_OPENBSD
  46 static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
  47 #else
  48 static device_type_t device_type = DEVICE_TYPE_TUN;
  49 #endif
  50
  51 bool setup_device(void) {
  52         char *type;
  53
  54         cp();
  55
  56         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  57                 device = DEFAULT_DEVICE;
  58
  59         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  60                 iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
  61
  62         if((device_fd = open(device, O_RDWR | O_NONBLOCK)) < 0) {
  63                 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
  64                 return false;
  65         }
  66
  67         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  68                 if(!strcasecmp(type, "tun"))
  69                         /* use default */;
  70                 else if(!strcasecmp(type, "tunnohead"))
  71                         device_type = DEVICE_TYPE_TUN;
  72                 else if(!strcasecmp(type, "tunifhead"))
  73                         device_type = DEVICE_TYPE_TUNIFHEAD;
  74                 else if(!strcasecmp(type, "tap"))
  75                         device_type = DEVICE_TYPE_TAP;
  76                 else {
  77                         logger(LOG_ERR, _("Unknown device type %s!"), type);
  78                         return false;
  79                 }
  80         } else {
  81                 if(strstr(device, "tap"))
  82                         device_type = DEVICE_TYPE_TAP;
  83         }
  84
  85         switch(device_type) {
  86                 default:
  87                         device_type = DEVICE_TYPE_TUN;
  88                 case DEVICE_TYPE_TUN:
  89 #ifdef TUNSIFHEAD
  90                 {
  91                         const int zero = 0;
  92                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
  93                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
  94                                 return false;
  95                         }
  96                 }
  97 #endif
  98 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
  99                 {
 100                         const int mode = IFF_BROADCAST | IFF_MULTICAST;
 101                         ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 102                 }
 103 #endif
 104
 105                         device_info = _("Generic BSD tun device");
 106                         break;
 107                 case DEVICE_TYPE_TUNIFHEAD:
 108 #ifdef TUNSIFHEAD
 109                 {
 110                         const int one = 1;
 111                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 112                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 113                                 return false;
 114                         }
 115                 }
 116 #endif
 117 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 118                 {
 119                                 const int mode = IFF_BROADCAST | IFF_MULTICAST;
 120                                 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 121                 }
 122 #endif
 123
 124                         device_info = _("Generic BSD tun device");
 125                         break;
 126                 case DEVICE_TYPE_TAP:
 127                         if(routing_mode == RMODE_ROUTER)
 128                                 overwrite_mac = true;
 129                         device_info = _("Generic BSD tap device");
 130                         break;
 131         }
 132
 133         logger(LOG_INFO, _("%s is a %s"), device, device_info);
 134
 135         return true;
 136 }
 137
 138 void close_device(void) {
 139         cp();
 140
 141         close(device_fd);
 142 }
 143
 144 bool read_packet(vpn_packet_t *packet) {
 145         int lenin;
 146
 147         cp();
 148
 149         switch(device_type) {
 150                 case DEVICE_TYPE_TUN:
 151                         if((lenin = read(device_fd, packet->data + 14, MTU - 14)) <= 0) {
 152                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 153                                            device, strerror(errno));
 154                                 return false;
 155                         }
 156
 157                         switch(packet->data[14] >> 4) {
 158                                 case 4:
 159                                         packet->data[12] = 0x08;
 160                                         packet->data[13] = 0x00;
 161                                         break;
 162                                 case 6:
 163                                         packet->data[12] = 0x86;
 164                                         packet->data[13] = 0xDD;
 165                                         break;
 166                                 default:
 167                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 168                                                            _ ("Unknown IP version %d while reading packet from %s %s"),
 169                                                            packet->data[14] >> 4, device_info, device);
 170                                         return false;
 171                         }
 172
 173                         packet->len = lenin + 14;
 174                         break;
 175
 176                 case DEVICE_TYPE_TUNIFHEAD: {
 177                         u_int32_t type;
 178                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 179
 180                         if((lenin = readv(device_fd, vector, 2)) <= 0) {
 181                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 182                                            device, strerror(errno));
 183                                 return false;
 184                         }
 185
 186                         switch (ntohl(type)) {
 187                                 case AF_INET:
 188                                         packet->data[12] = 0x08;
 189                                         packet->data[13] = 0x00;
 190                                         break;
 191
 192                                 case AF_INET6:
 193                                         packet->data[12] = 0x86;
 194                                         packet->data[13] = 0xDD;
 195                                         break;
 196
 197                                 default:
 198                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 199                                                            _ ("Unknown address family %x while reading packet from %s %s"),
 200                                                            ntohl(type), device_info, device);
 201                                         return false;
 202                         }
 203
 204                         packet->len = lenin + 10;
 205                         break;
 206                 }
 207
 208                 case DEVICE_TYPE_TAP:
 209                         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
 210                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 211                                            device, strerror(errno));
 212                                 return false;
 213                         }
 214
 215                         packet->len = lenin;
 216                         break;
 217
 218                 default:
 219                         return false;
 220         }
 221
 222         device_total_in += packet->len;
 223
 224         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
 225                            packet->len, device_info);
 226
 227         return true;
 228 }
 229
 230 bool write_packet(vpn_packet_t *packet)
 231 {
 232         cp();
 233
 234         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
 235                            packet->len, device_info);
 236
 237         switch(device_type) {
 238                 case DEVICE_TYPE_TUN:
 239                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 240                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 241                                            device, strerror(errno));
 242                                 return false;
 243                         }
 244                         break;
 245
 246                 case DEVICE_TYPE_TUNIFHEAD: {
 247                         u_int32_t type;
 248                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, packet->len - 14}};
 249                         int af;
 250
 251                         af = (packet->data[12] << 8) + packet->data[13];
 252
 253                         switch (af) {
 254                                 case 0x0800:
 255                                         type = htonl(AF_INET);
 256                                         break;
 257                                 case 0x86DD:
 258                                         type = htonl(AF_INET6);
 259                                         break;
 260                                 default:
 261                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 262                                                            _("Unknown address family %x while writing packet to %s %s"),
 263                                                            af, device_info, device);
 264                                         return false;
 265                         }
 266
 267                         if(writev(device_fd, vector, 2) < 0) {
 268                                 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
 269                                            strerror(errno));
 270                                 return false;
 271                         }
 272                         break;
 273                 }
 274
 275                 case DEVICE_TYPE_TAP:
 276                         if(write(device_fd, packet->data, packet->len) < 0) {
 277                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 278                                            device, strerror(errno));
 279                                 return false;
 280                         }
 281                         break;
 282
 283                 default:
 284                         return false;
 285         }
 286
 287         device_total_out += packet->len;
 288
 289         return true;
 290 }
 291
 292 void dump_device_stats(void)
 293 {
 294         cp();
 295
 296         logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
 297         logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
 298         logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
 299 }