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 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   size_t tsize;
 155
 156   if (buf == NULL)
 157     {
 158       finish(handle, GNUNET_SYSERR);
 159       return 0;
 160     }
 161   handle->th = NULL;
 162
 163   ret = 0;
 164
 165   if (handle->current != NULL)
 166   {
 167     tsize = ntohs(handle->current->msg->header.size);
 168     if (size >= tsize)
 169     {
 170       memcpy(buf, handle->current->msg, tsize);
 171     }
 172     else
 173     {
 174       return ret;
 175     }
 176   }
 177
 178   return ret;
 179 }
 180
 181 /**
 182  * Try to send messages from list of messages to send
 183  */
 184 static void process_pending_message(struct GNUNET_DV_Handle *handle)
 185 {
 186   struct GNUNET_TIME_Relative timeout;
 187
 188   if (handle->current != NULL)
 189     return;                     /* action already pending */
 190   if (GNUNET_YES != try_connect (handle))
 191     {
 192       finish (handle, GNUNET_SYSERR);
 193       return;
 194     }
 195
 196   /* schedule next action */
 197   handle->current = handle->pending_list;
 198   if (NULL == handle->current)
 199     {
 200       if (handle->do_destroy)
 201         {
 202           handle->do_destroy = GNUNET_NO;
 203           //GNUNET_DV_disconnect (handle); /* FIXME: replace with proper disconnect stuffs */
 204         }
 205       return;
 206     }
 207   handle->pending_list = handle->pending_list->next;
 208   handle->current->next = NULL;
 209
 210   timeout = GNUNET_TIME_absolute_get_remaining (handle->current->timeout);
 211   if (NULL ==
 212       (handle->th = GNUNET_CLIENT_notify_transmit_ready (handle->client,
 213                                                     ntohs(handle->current->msg->msgbuf_size),
 214                                                     timeout,
 215                                                     GNUNET_YES,
 216                                                     &transmit_pending, handle)))
 217     {
 218 #if DEBUG_STATISTICS
 219       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 220                   "Failed to transmit request to dv service.\n");
 221 #endif
 222       finish (handle, GNUNET_SYSERR);
 223     }
 224 }
 225
 226 /**
 227  * Add a pending message to the linked list
 228  *
 229  * @param handle handle to the specified DV api
 230  * @param msg the message to add to the list
 231  */
 232 static void add_pending(struct GNUNET_DV_Handle *handle, struct GNUNET_DV_SendMessage *msg)
 233 {
 234   struct PendingMessages *new_message;
 235   struct PendingMessages *pos;
 236   struct PendingMessages *last;
 237
 238   new_message = GNUNET_malloc(sizeof(struct PendingMessages));
 239   new_message->msg = msg;
 240
 241   if (handle->pending_list != NULL)
 242     {
 243       pos = handle->pending_list;
 244       while(pos != NULL)
 245         {
 246           last = pos;
 247           pos = pos->next;
 248         }
 249       new_message->next = last->next; /* Should always be null */
 250       last->next = new_message;
 251     }
 252   else
 253     {
 254       new_message->next = handle->pending_list; /* Will always be null */
 255       handle->pending_list = new_message;
 256     }
 257
 258   process_pending_message(handle);
 259 }
 260
 261
 262
 263
 264 void handle_message_receipt (void *cls,
 265                              const struct GNUNET_MessageHeader * msg)
 266 {
 267   struct GNUNET_DV_Handle *handle = cls;
 268   struct GNUNET_DV_MessageReceived *received_msg;
 269   size_t packed_msg_len;
 270   size_t sender_address_len;
 271   char *sender_address;
 272   char *packed_msg;
 273
 274   if (msg == NULL)
 275   {
 276     return; /* Connection closed? */
 277   }
 278
 279   GNUNET_assert(ntohs(msg->type) == GNUNET_MESSAGE_TYPE_TRANSPORT_DV_RECEIVE);
 280
 281   if (ntohs(msg->size) < sizeof(struct GNUNET_DV_MessageReceived))
 282     return;
 283
 284   received_msg = (struct GNUNET_DV_MessageReceived *)msg;
 285   packed_msg_len = ntohs(received_msg->msg_len);
 286   sender_address_len = ntohs(received_msg->sender_address_len);
 287   GNUNET_assert(ntohs(msg->size) == (sizeof(struct GNUNET_DV_MessageReceived) + packed_msg_len + sender_address_len));
 288
 289   sender_address = GNUNET_malloc(sender_address_len);
 290   memcpy(sender_address, &received_msg[1], sender_address_len);
 291   packed_msg = GNUNET_malloc(packed_msg_len);
 292   memcpy(packed_msg, &received_msg[1 + sender_address_len], packed_msg_len);
 293
 294   handle->receive_handler(handle->receive_cls,
 295                           &received_msg->sender,
 296                           packed_msg,
 297                           packed_msg_len,
 298                           ntohl(received_msg->distance),
 299                           sender_address,
 300                           sender_address_len);
 301
 302   GNUNET_free(sender_address);
 303
 304   GNUNET_CLIENT_receive (handle->client,
 305                          &handle_message_receipt,
 306                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 307 }
 308
 309 /**
 310  * Send a message from the plugin to the DV service indicating that
 311  * a message should be sent via DV to some peer.
 312  *
 313  * @param dv_handle the handle to the DV api
 314  * @param target the final target of the message
 315  * @param msgbuf the msg(s) to send
 316  * @param msgbuf_size the size of msgbuf
 317  * @param priority priority to pass on to core when sending the message
 318  * @param timeout how long can this message be delayed (pass through to core)
 319  * @param addr the address of this peer (internally known to DV)
 320  * @param addrlen the length of the peer address
 321  *
 322  */
 323 int GNUNET_DV_send (struct GNUNET_DV_Handle *dv_handle,
 324                     const struct GNUNET_PeerIdentity *target,
 325                     const char *msgbuf,
 326                     size_t msgbuf_size,
 327                     unsigned int priority,
 328                     struct GNUNET_TIME_Relative timeout,
 329                     const void *addr,
 330                     size_t addrlen)
 331 {
 332   struct GNUNET_DV_SendMessage *msg;
 333
 334   msg = GNUNET_malloc(sizeof(struct GNUNET_DV_SendMessage) + msgbuf_size + addrlen);
 335   msg->header.size = htons(sizeof(struct GNUNET_DV_SendMessage) + msgbuf_size + addrlen);
 336   msg->header.type = htons(GNUNET_MESSAGE_TYPE_TRANSPORT_DV_SEND);
 337   memcpy(&msg->target, target, sizeof(struct GNUNET_PeerIdentity));
 338   msg->msgbuf = GNUNET_malloc(msgbuf_size);
 339   memcpy(msg->msgbuf, msgbuf, msgbuf_size);
 340   msg->msgbuf_size = htons(msgbuf_size);
 341   msg->priority = htonl(priority);
 342   msg->timeout = timeout;
 343   msg->addrlen = htons(addrlen);
 344   memcpy(&msg[1], addr, addrlen);
 345
 346   add_pending(dv_handle, msg);
 347
 348   return GNUNET_OK;
 349 }
 350
 351 /**
 352  * Connect to the DV service
 353  *
 354  * @param sched the scheduler to use
 355  * @param cfg the configuration to use
 356  * @param receive_handler method call when on receipt from the service
 357  * @param receive_handler_cls closure for receive_handler
 358  *
 359  * @return handle to the DV service
 360  */
 361 struct GNUNET_DV_Handle *
 362 GNUNET_DV_connect (struct GNUNET_SCHEDULER_Handle *sched,
 363                   const struct GNUNET_CONFIGURATION_Handle *cfg,
 364                   GNUNET_DV_MessageReceivedHandler receive_handler,
 365                   void *receive_handler_cls)
 366 {
 367   struct GNUNET_DV_Handle *handle;
 368
 369   handle = GNUNET_malloc(sizeof(struct GNUNET_DV_Handle));
 370
 371   handle->cfg = cfg;
 372   handle->sched = sched;
 373   handle->pending_list = NULL;
 374   handle->current = NULL;
 375   handle->do_destroy = GNUNET_NO;
 376   handle->th = NULL;
 377   handle->client = GNUNET_CLIENT_connect(sched, "dv", cfg);
 378   handle->receive_handler = receive_handler;
 379   handle->receive_cls = receive_handler_cls;
 380
 381   if (handle->client == NULL)
 382     return NULL;
 383
 384   GNUNET_CLIENT_receive (handle->client,
 385                          &handle_message_receipt,
 386                          handle, GNUNET_TIME_UNIT_FOREVER_REL);
 387
 388   return handle;
 389 }
 390
 391 /**
 392  * Disconnect from the DV service
 393  *
 394  * @param handle the current handle to the service to disconnect
 395  */
 396 void GNUNET_DV_disconnect(struct GNUNET_DV_Handle *handle)
 397 {
 398   struct PendingMessages *pos;
 399
 400   GNUNET_assert(handle != NULL);
 401
 402   if (handle->th != NULL) /* We have a live transmit request in the Aether */
 403     {
 404       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
 405       handle->th = NULL;
 406     }
 407   if (handle->current != NULL) /* We are trying to send something now, clean it up */
 408     GNUNET_free(handle->current);
 409   while (NULL != (pos = handle->pending_list)) /* Remove all pending sends from the list */
 410     {
 411       handle->pending_list = pos->next;
 412       GNUNET_free(pos);
 413     }
 414   if (handle->client != NULL) /* Finally, disconnect from the service */
 415     {
 416       GNUNET_CLIENT_disconnect (handle->client, GNUNET_NO);
 417       handle->client = NULL;
 418     }
 419
 420   GNUNET_free (handle);
 421 }
 422
 423 /* end of dv_api.c */