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 #include "../transport/plugin_transport.h"
  40
  41
  42 struct PendingMessages
  43 {
  44   /**
  45    * Linked list of pending messages
  46    */
  47   struct PendingMessages *next;
  48
  49   /**
  50    * Message that is pending
  51    */
  52   struct GNUNET_DV_SendMessage *msg;
  53
  54   /**
  55    * Timeout for this message
  56    */
  57   struct GNUNET_TIME_Absolute timeout;
  58
  59 };
  60
  61
  62
  63 /**
  64  * Handle for the service.
  65  */
  66 struct GNUNET_DV_Handle
  67 {
  68   /**
  69    * Our scheduler.
  70    */
  71   struct GNUNET_SCHEDULER_Handle *sched;
  72
  73   /**
  74    * Configuration to use.
  75    */
  76   const struct GNUNET_CONFIGURATION_Handle *cfg;
  77
  78   /**
  79    * Socket (if available).
  80    */
  81   struct GNUNET_CLIENT_Connection *client;
  82
  83   /**
  84    * Currently pending transmission request.
  85    */
  86   struct GNUNET_CLIENT_TransmitHandle *th;
  87
  88   /**
  89    * List of the currently pending messages for the DV service.
  90    */
  91   struct PendingMessages *pending_list;
  92
  93   /**
  94    * Message we are currently sending.
  95    */
  96   struct PendingMessages *current;
  97
  98   /**
  99    * Kill off the connection and any pending messages.
 100    */
 101   int do_destroy;
 102
 103   /**
 104    * Handler for messages we receive from the DV service
 105    */
 106   GNUNET_DV_MessageReceivedHandler receive_handler;
 107
 108   /**
 109    * Closure for the receive handler
 110    */
 111   void *receive_cls;
 112
 113   /**
 114    * Current unique ID
 115    */
 116   uint32_t uid_gen;
 117
 118   /**
 119    * Hashmap containing outstanding send requests awaiting confirmation.
 120    */
 121   struct GNUNET_CONTAINER_MultiHashMap *send_callbacks;
 122
 123 };
 124
 125
 126 struct StartContext
 127 {
 128   /**
 129    * Start message
 130    */
 131   struct GNUNET_MessageHeader *message;
 132
 133   /**
 134    * Handle to service, in case of timeout
 135    */
 136   struct GNUNET_DV_Handle *handle;
 137 };
 138
 139 struct SendCallbackContext
 140 {
 141   /**
 142    * The continuation to call once a message is confirmed sent (or failed)
 143    */
 144   GNUNET_TRANSPORT_TransmitContinuation cont;
 145
 146   /**
 147    * Closure to call with send continuation.
 148    */
 149   void *cont_cls;
 150
 151   /**
 152    * Target of the message.
 153    */
 154   struct GNUNET_PeerIdentity target;
 155 };
 156
 157 /**
 158  * Convert unique ID to hash code.
 159  *
 160  * @param uid unique ID to convert
 161  * @param hash set to uid (extended with zeros)
 162  */
 163 static void
 164 hash_from_uid (uint32_t uid,
 165                GNUNET_HashCode *hash)
 166 {
 167   memset (hash, 0, sizeof(GNUNET_HashCode));
 168   *((uint32_t*)hash) = uid;
 169 }
 170
 171 /**
 172  * Try to (re)connect to the dv service.
 173  *
 174  * @return GNUNET_YES on success, GNUNET_NO on failure.
 175  */
 176 static int
 177 try_connect (struct GNUNET_DV_Handle *ret)
 178 {
 179   if (ret->client != NULL)
 180     return GNUNET_OK;
 181   ret->client = GNUNET_CLIENT_connect (ret->sched, "dv", ret->cfg);
 182   if (ret->client != NULL)
 183     return GNUNET_YES;
 184 #if DEBUG_STATISTICS
 185   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 186               _("Failed to connect to the dv service!\n"));
 187 #endif
 188   return GNUNET_NO;
 189 }
 190
 191 static void process_pending_message(struct GNUNET_DV_Handle *handle);
 192
 193 /**
 194  * Send complete, schedule next
 195  */
 196 static void
 197 finish (struct GNUNET_DV_Handle *handle, int code)
 198 {
 199   struct PendingMessages *pos = handle->current;
 200   handle->current = NULL;
 201   process_pending_message (handle);
 202
 203   GNUNET_free (pos);
 204 }
 205
 206
 207 static size_t
 208 transmit_pending (void *cls, size_t size, void *buf)
 209 {
 210   struct GNUNET_DV_Handle *handle = cls;
 211   size_t ret;
 212   size_t tsize;
 213
 214 #if DEBUG_DV
 215   if (handle->current != NULL)
 216     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV API: Transmit pending called with message type %d\n", ntohs(handle->current->msg->header.type));
 217 #endif
 218
 219   if (buf == NULL)
 220     {
 221 #if DEBUG_DV
 222       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV API: Transmit pending FAILED!\n\n\n");
 223 #endif
 224       finish(handle, GNUNET_SYSERR);
 225       return 0;
 226     }
 227   handle->th = NULL;
 228
 229   ret = 0;
 230
 231   if (handle->current != NULL)
 232   {
 233     tsize = ntohs(handle->current->msg->header.size);
 234     if (size >= tsize)
 235     {
 236       memcpy(buf, handle->current->msg, tsize);
 237 #if DEBUG_DV
 238       GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV API: Copied %d bytes into buffer!\n\n\n", tsize);
 239 #endif
 240       finish(handle, GNUNET_OK);
 241       return tsize;
 242     }
 243
 244   }
 245
 246   return ret;
 247 }
 248
 249 /**
 250  * Try to send messages from list of messages to send
 251  */
 252 static void process_pending_message(struct GNUNET_DV_Handle *handle)
 253 {
 254
 255   if (handle->current != NULL)
 256     return;                     /* action already pending */
 257   if (GNUNET_YES != try_connect (handle))
 258     {
 259       finish (handle, GNUNET_SYSERR);
 260       return;
 261     }
 262
 263   /* schedule next action */
 264   handle->current = handle->pending_list;
 265   if (NULL == handle->current)
 266     {
 267       if (handle->do_destroy)
 268         {
 269           handle->do_destroy = GNUNET_NO;
 270           //GNUNET_DV_disconnect (handle); /* FIXME: replace with proper disconnect stuffs */
 271         }
 272       return;
 273     }
 274   handle->pending_list = handle->pending_list->next;
 275   handle->current->next = NULL;
 276
 277   if (NULL ==
 278       (handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
 279                                                     ntohl(handle->current->msg->msgbuf_size),
 280                                                     handle->current->msg->timeout,
 281                                                     GNUNET_YES,
 282                                                     &transmit_pending, handle)))
 283     {
 284 #if DEBUG_DV
 285       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 286                   "Failed to transmit request to dv service.\n");
 287 #endif
 288       finish (handle, GNUNET_SYSERR);
 289     }
 290 }
 291
 292 /**
 293  * Add a pending message to the linked list
 294  *
 295  * @param handle handle to the specified DV api
 296  * @param msg the message to add to the list
 297  */
 298 static void add_pending(struct GNUNET_DV_Handle *handle, struct GNUNET_DV_SendMessage *msg)
 299 {
 300   struct PendingMessages *new_message;
 301   struct PendingMessages *pos;
 302   struct PendingMessages *last;
 303
 304   new_message = GNUNET_malloc(sizeof(struct PendingMessages));
 305   new_message->msg = msg;
 306
 307   if (handle->pending_list != NULL)
 308     {
 309       pos = handle->pending_list;
 310       while(pos != NULL)
 311         {
 312           last = pos;
 313           pos = pos->next;
 314         }
 315       new_message->next = last->next; /* Should always be null */
 316       last->next = new_message;
 317     }
 318   else
 319     {
 320       new_message->next = handle->pending_list; /* Will always be null */
 321       handle->pending_list = new_message;
 322     }
 323
 324   process_pending_message(handle);
 325 }
 326
 327 /**
 328  * Handles a message sent from the DV service to us.
 329  * Parse it out and give it to the plugin.
 330  *
 331  * @param cls the handle to the DV API
 332  * @param msg the message that was received
 333  */
 334 void handle_message_receipt (void *cls,
 335                              const struct GNUNET_MessageHeader * msg)
 336 {
 337   struct GNUNET_DV_Handle *handle = cls;
 338   struct GNUNET_DV_MessageReceived *received_msg;
 339   struct GNUNET_DV_SendResultMessage *send_result_msg;
 340   size_t packed_msg_len;
 341   size_t sender_address_len;
 342   char *sender_address;
 343   char *packed_msg;
 344   char *packed_msg_start;
 345   GNUNET_HashCode uidhash;
 346   struct SendCallbackContext *send_ctx;
 347
 348   if (msg == NULL)
 349   {
 350     return; /* Connection closed? */
 351   }
 352
 353   GNUNET_assert((ntohs(msg->type) == GNUNET_MESSAGE_TYPE_TRANSPORT_DV_RECEIVE) || (ntohs(msg->type) == GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND_RESULT));
 354
 355   switch (ntohs(msg->type))
 356   {
 357   case GNUNET_MESSAGE_TYPE_TRANSPORT_DV_RECEIVE:
 358     if (ntohs(msg->size) < sizeof(struct GNUNET_DV_MessageReceived))
 359       return;
 360
 361     received_msg = (struct GNUNET_DV_MessageReceived *)msg;
 362     packed_msg_len = ntohl(received_msg->msg_len);
 363     sender_address_len = ntohl(received_msg->sender_address_len);
 364
 365     GNUNET_assert(ntohs(msg->size) == (sizeof(struct GNUNET_DV_MessageReceived) + packed_msg_len + sender_address_len));
 366     sender_address = GNUNET_malloc(sender_address_len);
 367     memcpy(sender_address, &received_msg[1], sender_address_len);
 368     packed_msg_start = (char *)&received_msg[1];
 369     packed_msg = GNUNET_malloc(packed_msg_len);
 370     memcpy(packed_msg, &packed_msg_start[sender_address_len], packed_msg_len);
 371
 372 #if DEBUG_DV
 373     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV_API receive: packed message type: %d or %d\n", ntohs(((struct GNUNET_MessageHeader *)packed_msg)->type), ((struct GNUNET_MessageHeader *)packed_msg)->type);
 374     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV_API receive: message sender reported as %s\n", GNUNET_i2s(&received_msg->sender));
 375     GNUNET_log(GNUNET_ERROR_TYPE_DEBUG, "DV_API receive: distance is %u\n", ntohl(received_msg->distance));
 376 #endif
 377
 378     handle->receive_handler(handle->receive_cls,
 379                             &received_msg->sender,
 380                             packed_msg,
 381                             packed_msg_len,
 382                             ntohl(received_msg->distance),
 383                             sender_address,
 384                             sender_address_len);
 385
 386     GNUNET_free(sender_address);
 387     break;
 388   case GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND_RESULT:
 389     if (ntohs(msg->size) < sizeof(struct GNUNET_DV_SendResultMessage))
 390       return;
 391
 392     send_result_msg = (struct GNUNET_DV_SendResultMessage *)msg;
 393     hash_from_uid(ntohl(send_result_msg->uid), &uidhash);
 394     send_ctx = GNUNET_CONTAINER_multihashmap_get(handle->send_callbacks, &uidhash);
 395
 396     if ((send_ctx != NULL) && (send_ctx->cont != NULL))
 397       {
 398         if (ntohl(send_result_msg->result) == 0)
 399           {
 400             send_ctx->cont(send_ctx->cont_cls, &send_ctx->target, GNUNET_OK);
 401           }
 402         else
 403           {
 404             send_ctx->cont(send_ctx->cont_cls, &send_ctx->target, GNUNET_SYSERR);
 405           }
 406       }
 407     GNUNET_free_non_null(send_ctx);
 408     break;
 409   default:
 410     break;
 411   }
 412   GNUNET_CLIENT_receive (handle->client,
 413                          &handle_message_receipt,
 414                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 415 }
 416
 417 /**
 418  * Send a message from the plugin to the DV service indicating that
 419  * a message should be sent via DV to some peer.
 420  *
 421  * @param dv_handle the handle to the DV api
 422  * @param target the final target of the message
 423  * @param msgbuf the msg(s) to send
 424  * @param msgbuf_size the size of msgbuf
 425  * @param priority priority to pass on to core when sending the message
 426  * @param timeout how long can this message be delayed (pass through to core)
 427  * @param addr the address of this peer (internally known to DV)
 428  * @param addrlen the length of the peer address
 429  * @param cont continuation to call once the message has been sent (or failed)
 430  * @param cont_cls closure for continuation
 431  *
 432  */
 433 int GNUNET_DV_send (struct GNUNET_DV_Handle *dv_handle,
 434                     const struct GNUNET_PeerIdentity *target,
 435                     const char *msgbuf,
 436                     size_t msgbuf_size,
 437                     unsigned int priority,
 438                     struct GNUNET_TIME_Relative timeout,
 439                     const void *addr,
 440                     size_t addrlen,
 441                     GNUNET_TRANSPORT_TransmitContinuation
 442                     cont, void *cont_cls)
 443 {
 444   struct GNUNET_DV_SendMessage *msg;
 445   struct SendCallbackContext *send_ctx;
 446   char *end_of_message;
 447   GNUNET_HashCode uidhash;
 448 #if DEBUG_DV_MESSAGES
 449   dv_handle->uid_gen = GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_STRONG, UINT32_MAX);
 450 #else
 451   dv_handle->uid_gen++;
 452 #endif
 453
 454   msg = GNUNET_malloc(sizeof(struct GNUNET_DV_SendMessage) + addrlen + msgbuf_size);
 455   msg->header.size = htons(sizeof(struct GNUNET_DV_SendMessage) + addrlen + msgbuf_size);
 456   msg->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND);
 457   memcpy(&msg->target, target, sizeof(struct GNUNET_PeerIdentity));
 458   msg->msgbuf_size = htonl(msgbuf_size);
 459   msg->priority = htonl(priority);
 460   msg->timeout = timeout;
 461   msg->addrlen = htonl(addrlen);
 462   msg->uid = htonl(dv_handle->uid_gen);
 463   memcpy(&msg[1], addr, addrlen);
 464   end_of_message = (char *)&msg[1];
 465   end_of_message = &end_of_message[addrlen];
 466   memcpy(end_of_message, msgbuf, msgbuf_size);
 467   add_pending(dv_handle, msg);
 468   send_ctx = GNUNET_malloc(sizeof(struct SendCallbackContext));
 469   send_ctx->cont = cont;
 470   send_ctx->cont_cls = cont_cls;
 471   memcpy(&send_ctx->target, target, sizeof(struct GNUNET_PeerIdentity));
 472   hash_from_uid(dv_handle->uid_gen, &uidhash);
 473   GNUNET_CONTAINER_multihashmap_put(dv_handle->send_callbacks, &uidhash, send_ctx, GNUNET_CONTAINER_MULTIHASHMAPOPTION_REPLACE);
 474
 475   return GNUNET_OK;
 476 }
 477
 478 /* Forward declaration */
 479 void GNUNET_DV_disconnect(struct GNUNET_DV_Handle *handle);
 480
 481 static size_t
 482 transmit_start (void *cls, size_t size, void *buf)
 483 {
 484   struct StartContext *start_context = cls;
 485   struct GNUNET_DV_Handle *handle = start_context->handle;
 486   size_t tsize;
 487
 488   if (buf == NULL)
 489     {
 490       GNUNET_free(start_context->message);
 491       GNUNET_free(start_context);
 492       GNUNET_DV_disconnect(handle);
 493       return 0;
 494     }
 495
 496   tsize = ntohs(start_context->message->size);
 497   if (size >= tsize)
 498   {
 499     memcpy(buf, start_context->message, tsize);
 500     return tsize;
 501   }
 502
 503   return 0;
 504 }
 505
 506 /**
 507  * Connect to the DV service
 508  *
 509  * @param sched the scheduler to use
 510  * @param cfg the configuration to use
 511  * @param receive_handler method call when on receipt from the service
 512  * @param receive_handler_cls closure for receive_handler
 513  *
 514  * @return handle to the DV service
 515  */
 516 struct GNUNET_DV_Handle *
 517 GNUNET_DV_connect (struct GNUNET_SCHEDULER_Handle *sched,
 518                   const struct GNUNET_CONFIGURATION_Handle *cfg,
 519                   GNUNET_DV_MessageReceivedHandler receive_handler,
 520                   void *receive_handler_cls)
 521 {
 522   struct GNUNET_DV_Handle *handle;
 523   struct GNUNET_MessageHeader *start_message;
 524   struct StartContext *start_context;
 525   handle = GNUNET_malloc(sizeof(struct GNUNET_DV_Handle));
 526
 527   handle->cfg = cfg;
 528   handle->sched = sched;
 529   handle->pending_list = NULL;
 530   handle->current = NULL;
 531   handle->do_destroy = GNUNET_NO;
 532   handle->th = NULL;
 533   handle->client = GNUNET_CLIENT_connect(sched, "dv", cfg);
 534   handle->receive_handler = receive_handler;
 535   handle->receive_cls = receive_handler_cls;
 536
 537   if (handle->client == NULL)
 538     {
 539       GNUNET_free(handle);
 540       return NULL;
 541     }
 542
 543   start_message = GNUNET_malloc(sizeof(struct GNUNET_MessageHeader));
 544   start_message->size = htons(sizeof(struct GNUNET_MessageHeader));
 545   start_message->type = htons(GNUNET_MESSAGE_TYPE_DV_START);
 546
 547   start_context = GNUNET_malloc(sizeof(struct StartContext));
 548   start_context->handle = handle;
 549   start_context->message = start_message;
 550   GNUNET_CLIENT_notify_transmit_ready (handle->client,
 551                                        sizeof(struct GNUNET_MessageHeader),
 552                                        GNUNET_TIME_relative_multiply(GNUNET_TIME_UNIT_SECONDS, 60),
 553                                        GNUNET_YES,
 554                                        &transmit_start, start_context);
 555
 556   handle->send_callbacks = GNUNET_CONTAINER_multihashmap_create(100);
 557
 558   GNUNET_CLIENT_receive (handle->client,
 559                          &handle_message_receipt,
 560                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 561
 562   return handle;
 563 }
 564
 565 /**
 566  * Disconnect from the DV service
 567  *
 568  * @param handle the current handle to the service to disconnect
 569  */
 570 void GNUNET_DV_disconnect(struct GNUNET_DV_Handle *handle)
 571 {
 572   struct PendingMessages *pos;
 573
 574   GNUNET_assert(handle != NULL);
 575
 576   if (handle->th != NULL) /* We have a live transmit request in the Aether */
 577     {
 578       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
 579       handle->th = NULL;
 580     }
 581   if (handle->current != NULL) /* We are trying to send something now, clean it up */
 582     GNUNET_free(handle->current);
 583   while (NULL != (pos = handle->pending_list)) /* Remove all pending sends from the list */
 584     {
 585       handle->pending_list = pos->next;
 586       GNUNET_free(pos);
 587     }
 588   if (handle->client != NULL) /* Finally, disconnect from the service */
 589     {
 590       GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
 591       handle->client = NULL;
 592     }
 593
 594   GNUNET_free (handle);
 595 }
 596
 597 /* end of dv_api.c */