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 transport/dv_api.c
  23  * @brief library to access the DV service
  24  * @author Christian Grothoff
  25  * @author Not 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  * Handle for the service.
  62  */
  63 struct GNUNET_DV_Handle
  64 {
  65   /**
  66    * Our scheduler.
  67    */
  68   struct GNUNET_SCHEDULER_Handle *sched;
  69
  70   /**
  71    * Configuration to use.
  72    */
  73   const struct GNUNET_CONFIGURATION_Handle *cfg;
  74
  75   /**
  76    * Socket (if available).
  77    */
  78   struct GNUNET_CLIENT_Connection *client;
  79
  80   /**
  81    * Currently pending transmission request.
  82    */
  83   struct GNUNET_CLIENT_TransmitHandle *th;
  84
  85   /**
  86    * List of the currently pending messages for the DV service.
  87    */
  88   struct PendingMessages *pending_list;
  89
  90   /**
  91    * Message we are currently sending.
  92    */
  93   struct PendingMessages *current;
  94
  95   /**
  96    * Kill off the connection and any pending messages.
  97    */
  98   int do_destroy;
  99
 100   /**
 101    * Handler for messages we receive from the DV service
 102    */
 103   GNUNET_DV_MessageReceivedHandler receive_handler;
 104
 105   /**
 106    * Closure for the receive handler
 107    */
 108   void *receive_cls;
 109
 110 };
 111
 112
 113 /**
 114  * Try to (re)connect to the dv service.
 115  *
 116  * @return GNUNET_YES on success, GNUNET_NO on failure.
 117  */
 118 static int
 119 try_connect (struct GNUNET_DV_Handle *ret)
 120 {
 121   if (ret->client != NULL)
 122     return GNUNET_OK;
 123   ret->client = GNUNET_CLIENT_connect (ret->sched, "dv", ret->cfg);
 124   if (ret->client != NULL)
 125     return GNUNET_YES;
 126 #if DEBUG_STATISTICS
 127   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 128               _("Failed to connect to the dv service!\n"));
 129 #endif
 130   return GNUNET_NO;
 131 }
 132
 133 static void process_pending_message(struct GNUNET_DV_Handle *handle);
 134
 135 /**
 136  * Send complete, schedule next
 137  */
 138 static void
 139 finish (struct GNUNET_DV_Handle *handle, int code)
 140 {
 141   struct PendingMessages *pos = handle->current;
 142   handle->current = NULL;
 143   process_pending_message (handle);
 144
 145   GNUNET_free (pos);
 146 }
 147
 148
 149 static size_t
 150 transmit_pending (void *cls, size_t size, void *buf)
 151 {
 152   struct GNUNET_DV_Handle *handle = cls;
 153   size_t ret;
 154
 155   if (buf == NULL)
 156     {
 157       finish(handle, GNUNET_SYSERR);
 158       return 0;
 159     }
 160   handle->th = NULL;
 161
 162   return ret;
 163 }
 164
 165 /**
 166  * Try to send messages from list of messages to send
 167  */
 168 static void process_pending_message(struct GNUNET_DV_Handle *handle)
 169 {
 170   struct GNUNET_TIME_Relative timeout;
 171
 172   if (handle->current != NULL)
 173     return;                     /* action already pending */
 174   if (GNUNET_YES != try_connect (handle))
 175     {
 176       finish (handle, GNUNET_SYSERR);
 177       return;
 178     }
 179
 180   /* schedule next action */
 181   handle->current = handle->pending_list;
 182   if (NULL == handle->current)
 183     {
 184       if (handle->do_destroy)
 185         {
 186           handle->do_destroy = GNUNET_NO;
 187           //GNUNET_DV_disconnect (handle); /* FIXME: replace with proper disconnect stuffs */
 188         }
 189       return;
 190     }
 191   handle->pending_list = handle->pending_list->next;
 192   handle->current->next = NULL;
 193
 194   timeout = GNUNET_TIME_absolute_get_remaining (handle->current->timeout);
 195   if (NULL ==
 196       (handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
 197                                                     ntohs(handle->current->msg->msgbuf_size),
 198                                                     timeout,
 199                                                     GNUNET_YES,
 200                                                     &transmit_pending, handle)))
 201     {
 202 #if DEBUG_STATISTICS
 203       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 204                   "Failed to transmit request to dv service.\n");
 205 #endif
 206       finish (handle, GNUNET_SYSERR);
 207     }
 208 }
 209
 210 /**
 211  * Add a pending message to the linked list
 212  *
 213  * @param handle handle to the specified DV api
 214  * @param msg the message to add to the list
 215  */
 216 static void add_pending(struct GNUNET_DV_Handle *handle, struct GNUNET_DV_SendMessage *msg)
 217 {
 218   struct PendingMessages *new_message;
 219   struct PendingMessages *pos;
 220   struct PendingMessages *last;
 221
 222   new_message = GNUNET_malloc(sizeof(struct PendingMessages));
 223   new_message->msg = msg;
 224
 225   if (handle->pending_list != NULL)
 226     {
 227       pos = handle->pending_list;
 228       while(pos != NULL)
 229         {
 230           last = pos;
 231           pos = pos->next;
 232         }
 233       new_message->next = last->next; /* Should always be null */
 234       last->next = new_message;
 235     }
 236   else
 237     {
 238       new_message->next = handle->pending_list; /* Will always be null */
 239       handle->pending_list = new_message;
 240     }
 241
 242   process_pending_message(handle);
 243 }
 244
 245
 246
 247
 248 void handle_message_receipt (void *cls,
 249                              const struct GNUNET_MessageHeader * msg)
 250 {
 251   struct GNUNET_DV_Handle *handle = cls;
 252   struct GNUNET_DV_MessageReceived *received_msg;
 253   char *sender_address;
 254
 255   GNUNET_assert(ntohs(msg->type) == GNUNET_MESSAGE_TYPE_TRANSPORT_DV_RECEIVE);
 256
 257   if (ntohs(msg->size) < sizeof(struct GNUNET_DV_MessageReceived))
 258     return;
 259
 260   received_msg = (struct GNUNET_DV_MessageReceived *)msg;
 261   GNUNET_assert(ntohs(msg->size) == (sizeof(struct GNUNET_DV_MessageReceived) + ntohs(received_msg->msg->size) + ntohs(received_msg->sender_address_len)));
 262
 263   sender_address = GNUNET_malloc(ntohs(received_msg->sender_address_len));
 264   sender_address = memcpy(sender_address, &received_msg[1], ntohs(received_msg->sender_address_len));
 265
 266   handle->receive_handler(handle->receive_cls,
 267                           received_msg->sender,
 268                           received_msg->msg,
 269                           ntohl(received_msg->distance),
 270                           sender_address,
 271                           ntohs(received_msg->sender_address_len));
 272
 273   GNUNET_free(sender_address);
 274
 275   GNUNET_CLIENT_receive (handle->client,
 276                          &handle_message_receipt,
 277                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 278 }
 279
 280 /**
 281  * Send a message from the plugin to the DV service indicating that
 282  * a message should be sent via DV to some peer.
 283  *
 284  * @target the final target of the message
 285  * @msgbuf the msg(s) to send
 286  * @msgbuf_size the size of msgbuf
 287  * @priority priority to pass on to core when sending the message
 288  * @timeout how long can this message be delayed (pass through to core)
 289  * @addr the address of this peer (internally known to DV)
 290  * @addrlen the length of the peer address
 291  *
 292  */
 293 int GNUNET_DV_send (struct GNUNET_DV_Handle *dv_handle,
 294                     const struct GNUNET_PeerIdentity *target,
 295                     const char *msgbuf,
 296                     size_t msgbuf_size,
 297                     unsigned int priority,
 298                     struct GNUNET_TIME_Relative timeout,
 299                     const void *addr,
 300                     size_t addrlen)
 301 {
 302   struct GNUNET_DV_SendMessage *msg;
 303
 304   msg = GNUNET_malloc(sizeof(struct GNUNET_DV_SendMessage) + msgbuf_size + addrlen);
 305   msg->header.size = htons(sizeof(struct GNUNET_DV_SendMessage) + msgbuf_size + addrlen);
 306   msg->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND);
 307   memcpy(&msg->target, target, sizeof(struct GNUNET_PeerIdentity));
 308   msg->msgbuf = GNUNET_malloc(msgbuf_size);
 309   memcpy(msg->msgbuf, msgbuf, msgbuf_size);
 310   msg->msgbuf_size = htons(msgbuf_size);
 311   msg->priority = htonl(priority);
 312   msg->timeout = timeout;
 313   msg->addrlen = htons(addrlen);
 314   memcpy(&msg[1], addr, addrlen);
 315
 316   add_pending(dv_handle, msg);
 317   process_pending_message(dv_handle);
 318
 319   return GNUNET_OK;
 320 }
 321
 322 /**
 323  * Connect to the DV service
 324  *
 325  * @param sched the scheduler to use
 326  * @param cfg the configuration to use
 327  *
 328  * @return handle to the DV service
 329  */
 330 struct GNUNET_DV_Handle *
 331 GNUNET_DV_connect (struct GNUNET_SCHEDULER_Handle *sched,
 332                   const struct GNUNET_CONFIGURATION_Handle *cfg,
 333                   GNUNET_DV_MessageReceivedHandler receive_handler,
 334                   void *receive_handler_cls)
 335 {
 336   struct GNUNET_DV_Handle *handle;
 337
 338   handle = GNUNET_malloc(sizeof(struct GNUNET_DV_Handle));
 339
 340   handle->cfg = cfg;
 341   handle->sched = sched;
 342   handle->pending_list = NULL;
 343   handle->current = NULL;
 344   handle->do_destroy = GNUNET_NO;
 345   handle->th = NULL;
 346   handle->client = GNUNET_CLIENT_connect(sched, "dv", cfg);
 347   handle->receive_handler = receive_handler;
 348   handle->receive_cls = receive_handler_cls;
 349
 350   if (handle->client == NULL)
 351     return NULL;
 352
 353   GNUNET_CLIENT_receive (handle->client,
 354                          &handle_message_receipt,
 355                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 356
 357   return handle;
 358 }
 359
 360 /**
 361  * Disconnect from the DV service
 362  *
 363  * @param handle the current handle to the service to disconnect
 364  */
 365 void GNUNET_DV_disconnect(struct GNUNET_DV_Handle *handle)
 366 {
 367   struct PendingMessages *pos;
 368
 369   GNUNET_assert(handle != NULL);
 370
 371   if (handle->th != NULL) /* We have a live transmit request in the Aether */
 372     {
 373       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
 374       handle->th = NULL;
 375     }
 376   if (handle->current != NULL) /* We are trying to send something now, clean it up */
 377     GNUNET_free(handle->current);
 378   while (NULL != (pos = handle->pending_list)) /* Remove all pending sends from the list */
 379     {
 380       handle->pending_list = pos->next;
 381       GNUNET_free(pos);
 382     }
 383   if (handle->client != NULL) /* Finally, disconnect from the service */
 384     {
 385       GNUNET_CLIENT_disconnect (handle->client);
 386       handle->client = NULL;
 387     }
 388
 389   GNUNET_free (handle);
 390 }
 391
 392 /* end of dv_api.c */