src/transport/gnunet-service-transport_plugins.c

   1 /*
   2    This file is part of GNUnet.
   3    Copyright (C) 2010-2014 GNUnet e.V.
   4
   5    GNUnet is free software: you can redistribute it and/or modify it
   6    under the terms of the GNU Affero General Public License as published
   7    by the Free Software Foundation, either version 3 of the License,
   8    or (at your option) any later version.
   9
  10    GNUnet is distributed in the hope that it will be useful, but
  11    WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Affero General Public License for more details.
  14
  15    You should have received a copy of the GNU Affero General Public License
  16    along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17
  18      SPDX-License-Identifier: AGPL3.0-or-later
  19  */
  20
  21 /**
  22  * @file transport/gnunet-service-transport_plugins.c
  23  * @brief plugin management
  24  * @author Christian Grothoff
  25  */
  26 #include "platform.h"
  27 #include "gnunet-service-transport.h"
  28 #include "gnunet-service-transport_hello.h"
  29 #include "gnunet-service-transport_ats.h"
  30 #include "gnunet-service-transport_plugins.h"
  31
  32 /**
  33  * Entry in doubly-linked list of all of our plugins.
  34  */
  35 struct TransportPlugin {
  36   /**
  37    * This is a doubly-linked list.
  38    */
  39   struct TransportPlugin *next;
  40
  41   /**
  42    * This is a doubly-linked list.
  43    */
  44   struct TransportPlugin *prev;
  45
  46   /**
  47    * API of the transport as returned by the plugin's
  48    * initialization function.
  49    */
  50   struct GNUNET_TRANSPORT_PluginFunctions *api;
  51
  52   /**
  53    * Short name for the plugin (i.e. "tcp").
  54    */
  55   char *short_name;
  56
  57   /**
  58    * Name of the library (i.e. "gnunet_plugin_transport_tcp").
  59    */
  60   char *lib_name;
  61
  62   /**
  63    * Environment this transport service is using
  64    * for this plugin.
  65    */
  66   struct GNUNET_TRANSPORT_PluginEnvironment env;
  67 };
  68
  69 /**
  70  * Head of DLL of all loaded plugins.
  71  */
  72 static struct TransportPlugin *plugins_head;
  73
  74 /**
  75  * Head of DLL of all loaded plugins.
  76  */
  77 static struct TransportPlugin *plugins_tail;
  78
  79
  80 /**
  81  * Function that will be called to update metrics for an address
  82  *
  83  * @param cls closure
  84  * @param address address to update metrics for
  85  * @param session the session
  86  * @param distance new distance
  87  */
  88 static void
  89 plugin_env_update_distance(void *cls,
  90                            const struct GNUNET_HELLO_Address *address,
  91                            uint32_t distance)
  92 {
  93   GST_ats_update_distance(address,
  94                           distance);
  95 }
  96
  97
  98 /**
  99  * Function that will be called to figure if an address is an loopback,
 100  * LAN, WAN etc. address
 101  *
 102  * @param cls closure
 103  * @param addr binary address
 104  * @param addrlen length of the @a addr
 105  * @return type of the network @a addr belongs to
 106  */
 107 static enum GNUNET_NetworkType
 108 plugin_env_address_to_type(void *cls,
 109                            const struct sockaddr *addr,
 110                            size_t addrlen)
 111 {
 112   if (NULL == GST_is)
 113     {
 114       GNUNET_break(0);
 115       return GNUNET_NT_UNSPECIFIED;
 116     }
 117   return GNUNET_NT_scanner_get_type(GST_is,
 118                                     addr,
 119                                     addrlen);
 120 }
 121
 122
 123 /**
 124  * Load and initialize all plugins.  The respective functions will be
 125  * invoked by the plugins when the respective events happen.  The
 126  * closure will be set to a 'const char*' containing the name of the
 127  * plugin that caused the call.
 128  *
 129  * @param recv_cb function to call when data is received
 130  * @param address_cb function to call when our public addresses changed
 131  * @param session_start_cb function to call when a session was created
 132  * @param session_end_cb function to call when a session was terminated
 133  * @param address_type_cb function to call when a address type is requested
 134  */
 135 void
 136 GST_plugins_load(GNUNET_TRANSPORT_PluginReceiveCallback recv_cb,
 137                  GNUNET_TRANSPORT_AddressNotification address_cb,
 138                  GNUNET_TRANSPORT_SessionStart session_start_cb,
 139                  GNUNET_TRANSPORT_SessionEnd session_end_cb)
 140 {
 141   struct TransportPlugin *plug;
 142   struct TransportPlugin *next;
 143   unsigned long long tneigh;
 144   char *libname;
 145   char *plugs;
 146   char *pos;
 147   int fail;
 148
 149   if (GNUNET_OK !=
 150       GNUNET_CONFIGURATION_get_value_number(GST_cfg,
 151                                             "TRANSPORT",
 152                                             "NEIGHBOUR_LIMIT",
 153                                             &tneigh))
 154     {
 155       GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 156                  _("Transport service is lacking NEIGHBOUR_LIMIT option.\n"));
 157       return;
 158     }
 159   if (GNUNET_OK !=
 160       GNUNET_CONFIGURATION_get_value_string(GST_cfg,
 161                                             "TRANSPORT",
 162                                             "PLUGINS",
 163                                             &plugs))
 164     return;
 165   GNUNET_log(GNUNET_ERROR_TYPE_INFO,
 166              _("Starting transport plugins `%s'\n"),
 167              plugs);
 168   for (pos = strtok(plugs, " "); pos != NULL; pos = strtok(NULL, " "))
 169     {
 170       GNUNET_log(GNUNET_ERROR_TYPE_INFO,
 171                  _("Loading `%s' transport plugin\n"),
 172                  pos);
 173       GNUNET_asprintf(&libname,
 174                       "libgnunet_plugin_transport_%s",
 175                       pos);
 176       plug = GNUNET_new(struct TransportPlugin);
 177       plug->short_name = GNUNET_strdup(pos);
 178       plug->lib_name = libname;
 179       plug->env.cfg = GST_cfg;
 180       plug->env.my_identity = &GST_my_identity;
 181       plug->env.get_our_hello = &GST_hello_get;
 182       plug->env.cls = plug->short_name;
 183       plug->env.receive = recv_cb;
 184       plug->env.notify_address = address_cb;
 185       plug->env.session_start = session_start_cb;
 186       plug->env.session_end = session_end_cb;
 187       plug->env.get_address_type = &plugin_env_address_to_type;
 188       plug->env.update_address_distance = &plugin_env_update_distance;
 189       plug->env.max_connections = tneigh;
 190       plug->env.stats = GST_stats;
 191       GNUNET_CONTAINER_DLL_insert(plugins_head,
 192                                   plugins_tail,
 193                                   plug);
 194     }
 195   GNUNET_free(plugs);
 196   next = plugins_head;
 197   while (NULL != next)
 198     {
 199       plug = next;
 200       next = plug->next;
 201       plug->api = GNUNET_PLUGIN_load(plug->lib_name,
 202                                      &plug->env);
 203       if (NULL == plug->api)
 204         {
 205           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 206                      _("Failed to load transport plugin for `%s'\n"),
 207                      plug->lib_name);
 208           GNUNET_CONTAINER_DLL_remove(plugins_head,
 209                                       plugins_tail,
 210                                       plug);
 211           GNUNET_free(plug->short_name);
 212           GNUNET_free(plug->lib_name);
 213           GNUNET_free(plug);
 214           continue;
 215         }
 216       fail = GNUNET_NO;
 217       if (NULL == plug->api->address_pretty_printer)
 218         {
 219           fail = GNUNET_YES;
 220           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 221                      _("Missing function `%s' in transport plugin for `%s'\n"),
 222                      "address_pretty_printer",
 223                      plug->lib_name);
 224         }
 225       if (NULL == plug->api->address_to_string)
 226         {
 227           fail = GNUNET_YES;
 228           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 229                      _("Missing function `%s' in transport plugin for `%s'\n"),
 230                      "address_to_string",
 231                      plug->lib_name);
 232         }
 233       if (NULL == plug->api->string_to_address)
 234         {
 235           fail = GNUNET_YES;
 236           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 237                      _("Missing function `%s' in transport plugin for `%s'\n"),
 238                      "string_to_address",
 239                      plug->lib_name);
 240         }
 241       if (NULL == plug->api->check_address)
 242         {
 243           fail = GNUNET_YES;
 244           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 245                      _("Missing function `%s' in transport plugin for `%s'\n"),
 246                      "check_address",
 247                      plug->lib_name);
 248         }
 249       if (NULL == plug->api->get_session)
 250         {
 251           fail = GNUNET_YES;
 252           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 253                      _("Missing function `%s' in transport plugin for `%s'\n"),
 254                      "get_session",
 255                      plug->lib_name);
 256         }
 257       if (NULL == plug->api->get_network)
 258         {
 259           fail = GNUNET_YES;
 260           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 261                      _("Missing function `%s' in transport plugin for `%s'\n"),
 262                      "get_network",
 263                      plug->lib_name);
 264         }
 265       if (NULL == plug->api->send)
 266         {
 267           fail = GNUNET_YES;
 268           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 269                      _("Missing function `%s' in transport plugin for `%s'\n"),
 270                      "send",
 271                      plug->lib_name);
 272         }
 273       if (NULL == plug->api->disconnect_peer)
 274         {
 275           fail = GNUNET_YES;
 276           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 277                      _("Missing function `%s' in transport plugin for `%s'\n"),
 278                      "disconnect_peer",
 279                      plug->lib_name);
 280         }
 281       if (NULL == plug->api->disconnect_session)
 282         {
 283           fail = GNUNET_YES;
 284           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 285                      _("Missing function `%s' in transport plugin for `%s'\n"),
 286                      "disconnect_session",
 287                      plug->lib_name);
 288         }
 289       if (NULL == plug->api->query_keepalive_factor)
 290         {
 291           fail = GNUNET_YES;
 292           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 293                      _("Missing function `%s' in transport plugin for `%s'\n"),
 294                      "query_keepalive_factor",
 295                      plug->lib_name);
 296         }
 297       if (NULL == plug->api->update_session_timeout)
 298         {
 299           fail = GNUNET_YES;
 300           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 301                      _("Missing function `%s' in transport plugin for `%s'\n"),
 302                      "update_session_timeout",
 303                      plug->lib_name);
 304         }
 305       if (GNUNET_YES == fail)
 306         {
 307           GNUNET_log(GNUNET_ERROR_TYPE_ERROR,
 308                      _("Did not load plugin `%s' due to missing functions\n"),
 309                      plug->lib_name);
 310           GNUNET_break(NULL == GNUNET_PLUGIN_unload(plug->lib_name, plug->api));
 311           GNUNET_CONTAINER_DLL_remove(plugins_head,
 312                                       plugins_tail,
 313                                       plug);
 314           GNUNET_free(plug->short_name);
 315           GNUNET_free(plug->lib_name);
 316           GNUNET_free(plug);
 317         }
 318     }
 319 }
 320
 321
 322 /**
 323  * Unload all plugins
 324  */
 325 void
 326 GST_plugins_unload()
 327 {
 328   struct TransportPlugin *plug;
 329
 330   while (NULL != (plug = plugins_head))
 331     {
 332       GNUNET_break(NULL == GNUNET_PLUGIN_unload(plug->lib_name, plug->api));
 333       GNUNET_free(plug->lib_name);
 334       GNUNET_free(plug->short_name);
 335       GNUNET_CONTAINER_DLL_remove(plugins_head, plugins_tail, plug);
 336       GNUNET_free(plug);
 337     }
 338 }
 339
 340
 341 /**
 342  * Obtain the plugin API based on a plugin name.
 343  *
 344  * @param name name of the plugin
 345  * @return the plugin's API, NULL if the plugin is not loaded
 346  */
 347 struct GNUNET_TRANSPORT_PluginFunctions *
 348 GST_plugins_find(const char *name)
 349 {
 350   struct TransportPlugin *pos;
 351
 352   for (pos = plugins_head; NULL != pos; pos = pos->next)
 353     if (0 == strcmp(name, pos->short_name))
 354       break;
 355   if (NULL == pos)
 356     return NULL;
 357   return pos->api;
 358 }
 359
 360
 361 /**
 362  * Obtain the plugin API based on a the stripped plugin name after the underscore.
 363  *
 364  * Example: GST_plugins_printer_find (http_client) will return all plugins
 365  * starting with the prefix "http":
 366  * http_client or server if loaded
 367  *
 368  * @param name name of the plugin
 369  * @return the plugin's API, NULL if the plugin is not loaded
 370  */
 371 struct GNUNET_TRANSPORT_PluginFunctions *
 372 GST_plugins_printer_find(const char *name)
 373 {
 374   struct TransportPlugin *pos;
 375   char *stripped = GNUNET_strdup(name);
 376   char *sep = strchr(stripped, '_');
 377
 378   if (NULL != sep)
 379     sep[0] = '\0';
 380   for (pos = plugins_head; NULL != pos; pos = pos->next)
 381     if (pos->short_name == strstr(pos->short_name, stripped))
 382       break;
 383   GNUNET_free(stripped);
 384   if (NULL == pos)
 385     return NULL;
 386   return pos->api;
 387 }
 388
 389
 390 /**
 391  * Convert a given address to a human-readable format.  Note that the
 392  * return value will be overwritten on the next call to this function.
 393  *
 394  * @param address the address to convert
 395  * @return statically allocated (!) human-readable address
 396  */
 397 const char *
 398 GST_plugins_a2s(const struct GNUNET_HELLO_Address *address)
 399 {
 400   struct GNUNET_TRANSPORT_PluginFunctions *api;
 401   static char unable_to_show[1024];
 402   static const char *s;
 403
 404   if (NULL == address)
 405     return "<NULL>";
 406   if (0 == address->address_length)
 407     return TRANSPORT_SESSION_INBOUND_STRING; /* Addresse with length 0 are inbound, address->address itself may be NULL */
 408   api = GST_plugins_printer_find(address->transport_name);
 409   if (NULL == api)
 410     {
 411       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG,
 412                  "Failed to find transport plugin `%s'\n",
 413                  address->transport_name);
 414       return "<plugin unknown>";
 415     }
 416   if (0 == address->address_length)
 417     {
 418       GNUNET_snprintf(unable_to_show,
 419                       sizeof(unable_to_show),
 420                       "<unable to stringify %u-byte long address of %s transport>",
 421                       (unsigned int)address->address_length,
 422                       address->transport_name);
 423       return unable_to_show;
 424     }
 425   return(NULL != (s = api->address_to_string(NULL,
 426                                              address->address,
 427                                              address->address_length))
 428          ? s
 429          : "<invalid>");
 430 }
 431
 432
 433 /**
 434  * Register callback with all plugins to monitor their status.
 435  *
 436  * @param cb callback to register, NULL to unsubscribe
 437  * @param cb_cls closure for @a cb
 438  */
 439 void
 440 GST_plugins_monitor_subscribe(GNUNET_TRANSPORT_SessionInfoCallback cb,
 441                               void *cb_cls)
 442 {
 443   struct TransportPlugin *pos;
 444
 445   for (pos = plugins_head; NULL != pos; pos = pos->next)
 446     if (NULL == pos->api->setup_monitor)
 447       GNUNET_break(0);
 448     else
 449       pos->api->setup_monitor(pos->api->cls,
 450                               cb,
 451                               cb_cls);
 452 }
 453
 454
 455 /* end of file gnunet-service-transport_plugins.c */