src/bsd/device.c

   1 /*
   2     device.c -- Interaction BSD tun/tap device
   3     Copyright (C) 2001-2004 Ivo Timmermans <ivo@tinc-vpn.org>,
   4                   2001-2004 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 #ifdef TUNSIFHEAD
  53         const int zero = 0;
  54         const int one = 1;
  55 #endif
  56         char *type;
  57
  58         cp();
  59
  60         if(!get_config_string(lookup_config(config_tree, "Device"), &device))
  61                 device = DEFAULT_DEVICE;
  62
  63         if(!get_config_string(lookup_config(config_tree, "Interface"), &iface))
  64                 iface = rindex(device, '/') ? rindex(device, '/') + 1 : device;
  65
  66         if((device_fd = open(device, O_RDWR | O_NONBLOCK)) < 0) {
  67                 logger(LOG_ERR, _("Could not open %s: %s"), device, strerror(errno));
  68                 return false;
  69         }
  70
  71         if(get_config_string(lookup_config(config_tree, "DeviceType"), &type)) {
  72                 if(!strcasecmp(type, "tun"))
  73                         /* use default */;
  74                 else if(!strcasecmp(type, "tunnohead"))
  75                         device_type = DEVICE_TYPE_TUN;
  76                 else if(!strcasecmp(type, "tunifhead"))
  77                         device_type = DEVICE_TYPE_TUNIFHEAD;
  78                 else if(!strcasecmp(type, "tap"))
  79                         device_type = DEVICE_TYPE_TAP;
  80                 else {
  81                         logger(LOG_ERR, _("Unknown device type %s!"), type);
  82                         return false;
  83                 }
  84         } else {
  85                 if(strstr(device, "tap"))
  86                         device_type = DEVICE_TYPE_TAP;
  87         }
  88
  89         switch(device_type) {
  90                 default:
  91                         device_type = DEVICE_TYPE_TUN;
  92                 case DEVICE_TYPE_TUN:
  93 #ifdef TUNSIFHEAD
  94                         if(ioctl(device_fd, TUNSIFHEAD, &zero, sizeof zero) == -1) {
  95                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
  96                                 return false;
  97                         }
  98 #endif
  99                         device_info = _("Generic BSD tun device");
 100                         break;
 101                 case DEVICE_TYPE_TUNIFHEAD:
 102 #ifdef TUNSIFHEAD
 103                         if(ioctl(device_fd, TUNSIFHEAD, &one, sizeof one) == -1) {
 104                                 logger(LOG_ERR, _("System call `%s' failed: %s"), "ioctl", strerror(errno));
 105                                 return false;
 106                         }
 107 #endif
 108                         device_info = _("Generic BSD tun device");
 109                         break;
 110                 case DEVICE_TYPE_TAP:
 111                         if(routing_mode == RMODE_ROUTER)
 112                                 overwrite_mac = true;
 113                         device_info = _("Generic BSD tap device");
 114                         break;
 115         }
 116
 117         logger(LOG_INFO, _("%s is a %s"), device, device_info);
 118
 119         return true;
 120 }
 121
 122 void close_device(void) {
 123         cp();
 124
 125         close(device_fd);
 126 }
 127
 128 bool read_packet(vpn_packet_t *packet) {
 129         int lenin;
 130
 131         cp();
 132
 133         switch(device_type) {
 134                 case DEVICE_TYPE_TUN:
 135                         if((lenin = read(device_fd, packet->data + 14, MTU - 14)) <= 0) {
 136                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 137                                            device, strerror(errno));
 138                                 return false;
 139                         }
 140
 141                         switch(packet->data[14] >> 4) {
 142                                 case 4:
 143                                         packet->data[12] = 0x08;
 144                                         packet->data[13] = 0x00;
 145                                         break;
 146                                 case 6:
 147                                         packet->data[12] = 0x86;
 148                                         packet->data[13] = 0xDD;
 149                                         break;
 150                                 default:
 151                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 152                                                            _ ("Unknown IP version %d while reading packet from %s %s"),
 153                                                            packet->data[14] >> 4, device_info, device);
 154                                         return false;
 155                         }
 156
 157                         packet->len = lenin + 14;
 158                         break;
 159
 160                 case DEVICE_TYPE_TUNIFHEAD: {
 161                         u_int32_t type;
 162                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 163
 164                         if((lenin = readv(device_fd, vector, 2)) <= 0) {
 165                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 166                                            device, strerror(errno));
 167                                 return false;
 168                         }
 169
 170                         switch (ntohl(type)) {
 171                                 case AF_INET:
 172                                         packet->data[12] = 0x08;
 173                                         packet->data[13] = 0x00;
 174                                         break;
 175
 176                                 case AF_INET6:
 177                                         packet->data[12] = 0x86;
 178                                         packet->data[13] = 0xDD;
 179                                         break;
 180
 181                                 default:
 182                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 183                                                            _ ("Unknown address family %x while reading packet from %s %s"),
 184                                                            ntohl(type), device_info, device);
 185                                         return false;
 186                         }
 187
 188                         packet->len = lenin + 10;
 189                         break;
 190                 }
 191
 192                 case DEVICE_TYPE_TAP:
 193                         if((lenin = read(device_fd, packet->data, MTU)) <= 0) {
 194                                 logger(LOG_ERR, _("Error while reading from %s %s: %s"), device_info,
 195                                            device, strerror(errno));
 196                                 return false;
 197                         }
 198
 199                         packet->len = lenin;
 200                         break;
 201
 202                 default:
 203                         return false;
 204         }
 205
 206         device_total_in += packet->len;
 207
 208         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Read packet of %d bytes from %s"),
 209                            packet->len, device_info);
 210
 211         return true;
 212 }
 213
 214 bool write_packet(vpn_packet_t *packet)
 215 {
 216         cp();
 217
 218         ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Writing packet of %d bytes to %s"),
 219                            packet->len, device_info);
 220
 221         switch(device_type) {
 222                 case DEVICE_TYPE_TUN:
 223                         if(write(device_fd, packet->data + 14, packet->len - 14) < 0) {
 224                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 225                                            device, strerror(errno));
 226                                 return false;
 227                         }
 228                         break;
 229
 230                 case DEVICE_TYPE_TUNIFHEAD: {
 231                         u_int32_t type;
 232                         struct iovec vector[2] = {{&type, sizeof(type)}, {packet->data + 14, MTU - 14}};
 233                         int af;
 234
 235                         af = (packet->data[12] << 8) + packet->data[13];
 236
 237                         switch (af) {
 238                                 case 0x0800:
 239                                         type = htonl(AF_INET);
 240                                         break;
 241                                 case 0x86DD:
 242                                         type = htonl(AF_INET6);
 243                                         break;
 244                                 default:
 245                                         ifdebug(TRAFFIC) logger(LOG_ERR,
 246                                                            _("Unknown address family %x while writing packet to %s %s"),
 247                                                            af, device_info, device);
 248                                         return false;
 249                         }
 250
 251                         if(writev(device_fd, vector, 2) < 0) {
 252                                 logger(LOG_ERR, _("Can't write to %s %s: %s"), device_info, device,
 253                                            strerror(errno));
 254                                 return false;
 255                         }
 256                         break;
 257                 }
 258
 259                 case DEVICE_TYPE_TAP:
 260                         if(write(device_fd, packet->data, packet->len) < 0) {
 261                                 logger(LOG_ERR, _("Error while writing to %s %s: %s"), device_info,
 262                                            device, strerror(errno));
 263                                 return false;
 264                         }
 265                         break;
 266
 267                 default:
 268                         return false;
 269         }
 270
 271         device_total_out += packet->len;
 272
 273         return true;
 274 }
 275
 276 void dump_device_stats(void)
 277 {
 278         cp();
 279
 280         logger(LOG_DEBUG, _("Statistics for %s %s:"), device_info, device);
 281         logger(LOG_DEBUG, _(" total bytes in:  %10d"), device_total_in);
 282         logger(LOG_DEBUG, _(" total bytes out: %10d"), device_total_out);
 283 }