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                   2001-2008 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 #define DEFAULT_DEVICE "/dev/tun0"
  33
  34 typedef enum device_type {
  35         DEVICE_TYPE_TUN,
  36         DEVICE_TYPE_TUNIFHEAD,
  37         DEVICE_TYPE_TAP,
  38 } device_type_t;
  39
  40 int device_fd = -1;
  41 char *device = NULL;
  42 char *iface = NULL;
  43 static char *device_info = NULL;
  44 static int device_total_in = 0;
  45 static int device_total_out = 0;
  46 #if defined(HAVE_OPENBSD) || defined(HAVE_FREEBSD)
  47 static device_type_t device_type = DEVICE_TYPE_TUNIFHEAD;
  48 #else
  49 static device_type_t device_type = DEVICE_TYPE_TUN;
  50 #endif
  51
  52 bool setup_device(void) {
  53         char *type;
  54
  55         cp();
  56
  57         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  58                 device = xstrdup(DEFAULT_DEVICE);
  59
  60         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  61                 iface = xstrdup(rindex(device, '/') ? rindex(device, '/') + 1 : device);
  62
  63         if((device_fd = open(device, O_RDWR | O_NONBLOCK)) < 0) {
  64                 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
  65                 return false;
  66         }
  67
  68         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  69                 if(!strcasecmp(type, "tun"))
  70                         /* use default */;
  71                 else if(!strcasecmp(type, "tunnohead"))
  72                         device_type = DEVICE_TYPE_TUN;
  73                 else if(!strcasecmp(type, "tunifhead"))
  74                         device_type = DEVICE_TYPE_TUNIFHEAD;
  75                 else if(!strcasecmp(type, "tap"))
  76                         device_type = DEVICE_TYPE_TAP;
  77                 else {
  78                         logger(LOG_ERR, _("Unknown device type %s!"), type);
  79                         return false;
  80                 }
  81         } else {
  82                 if(strstr(device, "tap") || routing_mode != RMODE_ROUTER)
  83                         device_type = DEVICE_TYPE_TAP;
  84         }
  85
  86         switch(device_type) {
  87                 default:
  88                         device_type = DEVICE_TYPE_TUN;
  89                 case DEVICE_TYPE_TUN:
  90 #ifdef TUNSIFHEAD
  91                 {
  92                         const int zero = 0;
  93                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
  94                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
  95                                 return false;
  96                         }
  97                 }
  98 #endif
  99 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 100                 {
 101                         const int mode = IFF_BROADCAST | IFF_MULTICAST;
 102                         ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 103                 }
 104 #endif
 105
 106                         device_info = _("Generic BSD tun device");
 107                         break;
 108                 case DEVICE_TYPE_TUNIFHEAD:
 109 #ifdef TUNSIFHEAD
 110                 {
 111                         const int one = 1;
 112                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 113                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 114                                 return false;
 115                         }
 116                 }
 117 #endif
 118 #if defined(TUNSIFMODE) && defined(IFF_BROADCAST) && defined(IFF_MULTICAST)
 119                 {
 120                                 const int mode = IFF_BROADCAST | IFF_MULTICAST;
 121                                 ioctl(device_fd, TUNSIFMODE, &mode, sizeof mode);
 122                 }
 123 #endif
 124
 125                         device_info = _("Generic BSD tun device");
 126                         break;
 127                 case DEVICE_TYPE_TAP:
 128                         if(routing_mode == RMODE_ROUTER)
 129                                 overwrite_mac = true;
 130                         device_info = _("Generic BSD tap device");
 131                         break;
 132         }
 133
 134         logger(LOG_INFO, _("%s is a %s"), device, device_info);
 135
 136         return true;
 137 }
 138
 139 void close_device(void) {
 140         cp();
 141
 142         close(device_fd);
 143 }
 144
 145 bool read_packet(vpn_packet_t *packet) {
 146         int lenin;
 147
 148         cp();
 149
 150         switch(device_type) {
 151                 case DEVICE_TYPE_TUN:
 152                         if((lenin = read(device_fd, packet->data + 14, MTU - 14)) <= 0) {
 153                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 154                                            device, strerror(errno));
 155                                 return false;
 156                         }
 157
 158                         switch(packet->data[14] >> 4) {
 159                                 case 4:
 160                                         packet->data[12] = 0x08;
 161                                         packet->data[13] = 0x00;
 162                                         break;
 163                                 case 6:
 164                                         packet->data[12] = 0x86;
 165                                         packet->data[13] = 0xDD;
 166                                         break;
 167                                 default:
 168                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 169                                                            _ ("Unknown IP version %d while reading packet from %s %s"),
 170                                                            packet->data[14] >> 4, device_info, device);
 171                                         return false;
 172                         }
 173
 174                         packet->len = lenin + 14;
 175                         break;
 176
 177                 case DEVICE_TYPE_TUNIFHEAD: {
 178                         u_int32_t type;
 179                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 180
 181                         if((lenin = readv(device_fd, vector, 2)) <= 0) {
 182                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 183                                            device, strerror(errno));
 184                                 return false;
 185                         }
 186
 187                         switch (ntohl(type)) {
 188                                 case AF_INET:
 189                                         packet->data[12] = 0x08;
 190                                         packet->data[13] = 0x00;
 191                                         break;
 192
 193                                 case AF_INET6:
 194                                         packet->data[12] = 0x86;
 195                                         packet->data[13] = 0xDD;
 196                                         break;
 197
 198                                 default:
 199                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 200                                                            _ ("Unknown address family %x while reading packet from %s %s"),
 201                                                            ntohl(type), device_info, device);
 202                                         return false;
 203                         }
 204
 205                         packet->len = lenin + 10;
 206                         break;
 207                 }
 208
 209                 case DEVICE_TYPE_TAP:
 210                         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
 211                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 212                                            device, strerror(errno));
 213                                 return false;
 214                         }
 215
 216                         packet->len = lenin;
 217                         break;
 218
 219                 default:
 220                         return false;
 221         }
 222
 223         device_total_in += packet->len;
 224
 225         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
 226                            packet->len, device_info);
 227
 228         return true;
 229 }
 230
 231 bool write_packet(vpn_packet_t *packet)
 232 {
 233         cp();
 234
 235         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
 236                            packet->len, device_info);
 237
 238         switch(device_type) {
 239                 case DEVICE_TYPE_TUN:
 240                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 241                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 242                                            device, strerror(errno));
 243                                 return false;
 244                         }
 245                         break;
 246
 247                 case DEVICE_TYPE_TUNIFHEAD: {
 248                         u_int32_t type;
 249                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, packet->len - 14}};
 250                         int af;
 251
 252                         af = (packet->data[12] << 8) + packet->data[13];
 253
 254                         switch (af) {
 255                                 case 0x0800:
 256                                         type = htonl(AF_INET);
 257                                         break;
 258                                 case 0x86DD:
 259                                         type = htonl(AF_INET6);
 260                                         break;
 261                                 default:
 262                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 263                                                            _("Unknown address family %x while writing packet to %s %s"),
 264                                                            af, device_info, device);
 265                                         return false;
 266                         }
 267
 268                         if(writev(device_fd, vector, 2) < 0) {
 269                                 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
 270                                            strerror(errno));
 271                                 return false;
 272                         }
 273                         break;
 274                 }
 275
 276                 case DEVICE_TYPE_TAP:
 277                         if(write(device_fd, packet->data, packet->len) < 0) {
 278                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 279                                            device, strerror(errno));
 280                                 return false;
 281                         }
 282                         break;
 283
 284                 default:
 285                         return false;
 286         }
 287
 288         device_total_out += packet->len;
 289
 290         return true;
 291 }
 292
 293 void dump_device_stats(void)
 294 {
 295         cp();
 296
 297         logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
 298         logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
 299         logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
 300 }