src/dv/dv_api.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009, 2010 Christian Grothoff (and other contributing authors)
   4
   5      GNUnet is free software; you can redistribute it and/or modify
   6      it under the terms of the GNU General Public License as published
   7      by the Free Software Foundation; either version 2, or (at your
   8      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      General Public License for more details.
  14
  15      You should have received a copy of the GNU General Public License
  16      along with GNUnet; see the file COPYING.  If not, write to the
  17      Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  18      Boston, MA 02111-1307, USA.
  19 */
  20
  21 /**
  22  * @file dv/dv_api.c
  23  * @brief library to access the DV service
  24  * @author Christian Grothoff
  25  * @author Nathan Evans
  26  */
  27 #include "platform.h"
  28 #include "gnunet_bandwidth_lib.h"
  29 #include "gnunet_client_lib.h"
  30 #include "gnunet_constants.h"
  31 #include "gnunet_container_lib.h"
  32 #include "gnunet_arm_service.h"
  33 #include "gnunet_hello_lib.h"
  34 #include "gnunet_protocols.h"
  35 #include "gnunet_server_lib.h"
  36 #include "gnunet_time_lib.h"
  37 #include "gnunet_dv_service.h"
  38 #include "dv.h"
  39
  40
  41 struct PendingMessages
  42 {
  43   /**
  44    * Linked list of pending messages
  45    */
  46   struct PendingMessages *next;
  47
  48   /**
  49    * Message that is pending
  50    */
  51   struct GNUNET_DV_SendMessage *msg;
  52
  53   /**
  54    * Timeout for this message
  55    */
  56   struct GNUNET_TIME_Absolute timeout;
  57
  58 };
  59
  60
  61
  62 /**
  63  * Handle for the service.
  64  */
  65 struct GNUNET_DV_Handle
  66 {
  67   /**
  68    * Our scheduler.
  69    */
  70   struct GNUNET_SCHEDULER_Handle *sched;
  71
  72   /**
  73    * Configuration to use.
  74    */
  75   const struct GNUNET_CONFIGURATION_Handle *cfg;
  76
  77   /**
  78    * Socket (if available).
  79    */
  80   struct GNUNET_CLIENT_Connection *client;
  81
  82   /**
  83    * Currently pending transmission request.
  84    */
  85   struct GNUNET_CLIENT_TransmitHandle *th;
  86
  87   /**
  88    * List of the currently pending messages for the DV service.
  89    */
  90   struct PendingMessages *pending_list;
  91
  92   /**
  93    * Message we are currently sending.
  94    */
  95   struct PendingMessages *current;
  96
  97   /**
  98    * Kill off the connection and any pending messages.
  99    */
 100   int do_destroy;
 101
 102   /**
 103    * Handler for messages we receive from the DV service
 104    */
 105   GNUNET_DV_MessageReceivedHandler receive_handler;
 106
 107   /**
 108    * Closure for the receive handler
 109    */
 110   void *receive_cls;
 111
 112 };
 113
 114
 115 struct StartContext
 116 {
 117
 118   /**
 119    * Start message
 120    */
 121   struct GNUNET_MessageHeader *message;
 122
 123   /**
 124    * Handle to service, in case of timeout
 125    */
 126   struct GNUNET_DV_Handle *handle;
 127 };
 128
 129
 130 /**
 131  * Try to (re)connect to the dv service.
 132  *
 133  * @return GNUNET_YES on success, GNUNET_NO on failure.
 134  */
 135 static int
 136 try_connect (struct GNUNET_DV_Handle *ret)
 137 {
 138   if (ret->client != NULL)
 139     return GNUNET_OK;
 140   ret->client = GNUNET_CLIENT_connect (ret->sched, "dv", ret->cfg);
 141   if (ret->client != NULL)
 142     return GNUNET_YES;
 143 #if DEBUG_STATISTICS
 144   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 145               _("Failed to connect to the dv service!\n"));
 146 #endif
 147   return GNUNET_NO;
 148 }
 149
 150 static void process_pending_message(struct GNUNET_DV_Handle *handle);
 151
 152 /**
 153  * Send complete, schedule next
 154  */
 155 static void
 156 finish (struct GNUNET_DV_Handle *handle, int code)
 157 {
 158   struct PendingMessages *pos = handle->current;
 159   handle->current = NULL;
 160   process_pending_message (handle);
 161
 162   GNUNET_free (pos);
 163 }
 164
 165
 166 static size_t
 167 transmit_pending (void *cls, size_t size, void *buf)
 168 {
 169   struct GNUNET_DV_Handle *handle = cls;
 170   size_t ret;
 171   size_t tsize;
 172
 173   if (buf == NULL)
 174     {
 175       finish(handle, GNUNET_SYSERR);
 176       return 0;
 177     }
 178   handle->th = NULL;
 179
 180   ret = 0;
 181
 182   if (handle->current != NULL)
 183   {
 184     tsize = ntohs(handle->current->msg->header.size);
 185     if (size >= tsize)
 186     {
 187       memcpy(buf, handle->current->msg, tsize);
 188     }
 189     else
 190     {
 191       return ret;
 192     }
 193   }
 194
 195   return ret;
 196 }
 197
 198 /**
 199  * Try to send messages from list of messages to send
 200  */
 201 static void process_pending_message(struct GNUNET_DV_Handle *handle)
 202 {
 203   struct GNUNET_TIME_Relative timeout;
 204
 205   if (handle->current != NULL)
 206     return;                     /* action already pending */
 207   if (GNUNET_YES != try_connect (handle))
 208     {
 209       finish (handle, GNUNET_SYSERR);
 210       return;
 211     }
 212
 213   /* schedule next action */
 214   handle->current = handle->pending_list;
 215   if (NULL == handle->current)
 216     {
 217       if (handle->do_destroy)
 218         {
 219           handle->do_destroy = GNUNET_NO;
 220           //GNUNET_DV_disconnect (handle); /* FIXME: replace with proper disconnect stuffs */
 221         }
 222       return;
 223     }
 224   handle->pending_list = handle->pending_list->next;
 225   handle->current->next = NULL;
 226
 227   timeout = GNUNET_TIME_absolute_get_remaining (handle->current->timeout);
 228   if (NULL ==
 229       (handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
 230                                                     ntohs(handle->current->msg->msgbuf_size),
 231                                                     timeout,
 232                                                     GNUNET_YES,
 233                                                     &transmit_pending, handle)))
 234     {
 235 #if DEBUG_DV
 236       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 237                   "Failed to transmit request to dv service.\n");
 238 #endif
 239       finish (handle, GNUNET_SYSERR);
 240     }
 241 }
 242
 243 /**
 244  * Add a pending message to the linked list
 245  *
 246  * @param handle handle to the specified DV api
 247  * @param msg the message to add to the list
 248  */
 249 static void add_pending(struct GNUNET_DV_Handle *handle, struct GNUNET_DV_SendMessage *msg)
 250 {
 251   struct PendingMessages *new_message;
 252   struct PendingMessages *pos;
 253   struct PendingMessages *last;
 254
 255   new_message = GNUNET_malloc(sizeof(struct PendingMessages));
 256   new_message->msg = msg;
 257
 258   if (handle->pending_list != NULL)
 259     {
 260       pos = handle->pending_list;
 261       while(pos != NULL)
 262         {
 263           last = pos;
 264           pos = pos->next;
 265         }
 266       new_message->next = last->next; /* Should always be null */
 267       last->next = new_message;
 268     }
 269   else
 270     {
 271       new_message->next = handle->pending_list; /* Will always be null */
 272       handle->pending_list = new_message;
 273     }
 274
 275   process_pending_message(handle);
 276 }
 277
 278
 279 void handle_message_receipt (void *cls,
 280                              const struct GNUNET_MessageHeader * msg)
 281 {
 282   struct GNUNET_DV_Handle *handle = cls;
 283   struct GNUNET_DV_MessageReceived *received_msg;
 284   size_t packed_msg_len;
 285   size_t sender_address_len;
 286   char *sender_address;
 287   char *packed_msg;
 288
 289   if (msg == NULL)
 290   {
 291     return; /* Connection closed? */
 292   }
 293
 294 #if DEBUG_DV
 295   fprintf(stdout, "dv api receives message of type %d or raw %d\n", ntohs(msg->type), msg->type);
 296 #endif
 297   GNUNET_assert(ntohs(msg->type) == GNUNET_MESSAGE_TYPE_TRANSPORT_DV_RECEIVE);
 298
 299   if (ntohs(msg->size) < sizeof(struct GNUNET_DV_MessageReceived))
 300     return;
 301
 302   received_msg = (struct GNUNET_DV_MessageReceived *)msg;
 303   packed_msg_len = ntohs(received_msg->msg_len);
 304   sender_address_len = ntohs(received_msg->sender_address_len);
 305   GNUNET_assert(ntohs(msg->size) == (sizeof(struct GNUNET_DV_MessageReceived) + packed_msg_len + sender_address_len));
 306
 307   sender_address = GNUNET_malloc(sender_address_len);
 308   memcpy(sender_address, &received_msg[1], sender_address_len);
 309   packed_msg = GNUNET_malloc(packed_msg_len);
 310   memcpy(packed_msg, &received_msg[1 + sender_address_len], packed_msg_len);
 311
 312   handle->receive_handler(handle->receive_cls,
 313                           &received_msg->sender,
 314                           packed_msg,
 315                           packed_msg_len,
 316                           ntohl(received_msg->distance),
 317                           sender_address,
 318                           sender_address_len);
 319
 320   GNUNET_free(sender_address);
 321
 322   GNUNET_CLIENT_receive (handle->client,
 323                          &handle_message_receipt,
 324                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 325 }
 326
 327 /**
 328  * Send a message from the plugin to the DV service indicating that
 329  * a message should be sent via DV to some peer.
 330  *
 331  * @param dv_handle the handle to the DV api
 332  * @param target the final target of the message
 333  * @param msgbuf the msg(s) to send
 334  * @param msgbuf_size the size of msgbuf
 335  * @param priority priority to pass on to core when sending the message
 336  * @param timeout how long can this message be delayed (pass through to core)
 337  * @param addr the address of this peer (internally known to DV)
 338  * @param addrlen the length of the peer address
 339  *
 340  */
 341 int GNUNET_DV_send (struct GNUNET_DV_Handle *dv_handle,
 342                     const struct GNUNET_PeerIdentity *target,
 343                     const char *msgbuf,
 344                     size_t msgbuf_size,
 345                     unsigned int priority,
 346                     struct GNUNET_TIME_Relative timeout,
 347                     const void *addr,
 348                     size_t addrlen)
 349 {
 350   struct GNUNET_DV_SendMessage *msg;
 351
 352   msg = GNUNET_malloc(sizeof(struct GNUNET_DV_SendMessage) + msgbuf_size + addrlen);
 353   msg->header.size = htons(sizeof(struct GNUNET_DV_SendMessage) + msgbuf_size + addrlen);
 354   msg->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND);
 355   memcpy(&msg->target, target, sizeof(struct GNUNET_PeerIdentity));
 356   msg->msgbuf = GNUNET_malloc(msgbuf_size);
 357   memcpy(msg->msgbuf, msgbuf, msgbuf_size);
 358   msg->msgbuf_size = htons(msgbuf_size);
 359   msg->priority = htonl(priority);
 360   msg->timeout = timeout;
 361   msg->addrlen = htons(addrlen);
 362   memcpy(&msg[1], addr, addrlen);
 363
 364   add_pending(dv_handle, msg);
 365
 366   return GNUNET_OK;
 367 }
 368
 369 /* Forward declaration */
 370 void GNUNET_DV_disconnect(struct GNUNET_DV_Handle *handle);
 371
 372 static size_t
 373 transmit_start (void *cls, size_t size, void *buf)
 374 {
 375   struct StartContext *start_context = cls;
 376   struct GNUNET_DV_Handle *handle = start_context->handle;
 377   size_t tsize;
 378
 379   if (buf == NULL)
 380     {
 381       GNUNET_free(start_context->message);
 382       GNUNET_free(start_context);
 383       GNUNET_DV_disconnect(handle);
 384       return 0;
 385     }
 386
 387   tsize = ntohs(start_context->message->size);
 388   if (size >= tsize)
 389   {
 390     memcpy(buf, start_context->message, tsize);
 391     return tsize;
 392   }
 393
 394   return 0;
 395 }
 396
 397 /**
 398  * Connect to the DV service
 399  *
 400  * @param sched the scheduler to use
 401  * @param cfg the configuration to use
 402  * @param receive_handler method call when on receipt from the service
 403  * @param receive_handler_cls closure for receive_handler
 404  *
 405  * @return handle to the DV service
 406  */
 407 struct GNUNET_DV_Handle *
 408 GNUNET_DV_connect (struct GNUNET_SCHEDULER_Handle *sched,
 409                   const struct GNUNET_CONFIGURATION_Handle *cfg,
 410                   GNUNET_DV_MessageReceivedHandler receive_handler,
 411                   void *receive_handler_cls)
 412 {
 413   struct GNUNET_DV_Handle *handle;
 414   struct GNUNET_MessageHeader *start_message;
 415   struct StartContext *start_context;
 416   handle = GNUNET_malloc(sizeof(struct GNUNET_DV_Handle));
 417
 418   handle->cfg = cfg;
 419   handle->sched = sched;
 420   handle->pending_list = NULL;
 421   handle->current = NULL;
 422   handle->do_destroy = GNUNET_NO;
 423   handle->th = NULL;
 424   handle->client = GNUNET_CLIENT_connect(sched, "dv", cfg);
 425   handle->receive_handler = receive_handler;
 426   handle->receive_cls = receive_handler_cls;
 427
 428   if (handle->client == NULL)
 429     {
 430       GNUNET_free(handle);
 431       return NULL;
 432     }
 433
 434   start_message = GNUNET_malloc(sizeof(struct GNUNET_MessageHeader));
 435   start_message->size = htons(sizeof(struct GNUNET_MessageHeader));
 436   start_message->type = htons(GNUNET_MESSAGE_TYPE_DV_START);
 437
 438   start_context = GNUNET_malloc(sizeof(struct StartContext));
 439   start_context->handle = handle;
 440   start_context->message = start_message;
 441   GNUNET_CLIENT_notify_transmit_ready (handle->client,
 442                                        sizeof(struct GNUNET_MessageHeader),
 443                                        GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 60),
 444                                        GNUNET_YES,
 445                                        &transmit_start, start_context);
 446
 447   GNUNET_CLIENT_receive (handle->client,
 448                          &handle_message_receipt,
 449                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 450
 451   return handle;
 452 }
 453
 454 /**
 455  * Disconnect from the DV service
 456  *
 457  * @param handle the current handle to the service to disconnect
 458  */
 459 void GNUNET_DV_disconnect(struct GNUNET_DV_Handle *handle)
 460 {
 461   struct PendingMessages *pos;
 462
 463   GNUNET_assert(handle != NULL);
 464
 465   if (handle->th != NULL) /* We have a live transmit request in the Aether */
 466     {
 467       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
 468       handle->th = NULL;
 469     }
 470   if (handle->current != NULL) /* We are trying to send something now, clean it up */
 471     GNUNET_free(handle->current);
 472   while (NULL != (pos = handle->pending_list)) /* Remove all pending sends from the list */
 473     {
 474       handle->pending_list = pos->next;
 475       GNUNET_free(pos);
 476     }
 477   if (handle->client != NULL) /* Finally, disconnect from the service */
 478     {
 479       GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
 480       handle->client = NULL;
 481     }
 482
 483   GNUNET_free (handle);
 484 }
 485
 486 /* end of dv_api.c */