src/transport/transport_api.c

   1 /*
   2      This file is part of GNUnet.
   3      (C) 2009 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/transport_api.c
  23  * @brief library to access the low-level P2P IO service
  24  * @author Christian Grothoff
  25  *
  26  * TODO:
  27  * - set_quota with low bandwidth should cause peer
  28  *   disconnects (currently never does that) (MINOR)
  29  */
  30 #include "platform.h"
  31 #include "gnunet_client_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_transport_service.h"
  38 #include "transport.h"
  39
  40 /**
  41  * After how long do we give up on transmitting a HELLO
  42  * to the service?
  43  */
  44 #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
  45
  46 /**
  47  * How long should ARM wait when starting up the
  48  * transport service before reporting back?
  49  */
  50 #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  51
  52 /**
  53  * How long should ARM wait when stopping the
  54  * transport service before reporting back?
  55  */
  56 #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
  57
  58 /**
  59  * Entry in linked list of all of our current neighbours.
  60  */
  61 struct NeighbourList
  62 {
  63
  64   /**
  65    * This is a linked list.
  66    */
  67   struct NeighbourList *next;
  68
  69   /**
  70    * Active transmit handle, can be NULL.  Used to move
  71    * from ready to wait list on disconnect and to block
  72    * two transmissions to the same peer from being scheduled
  73    * at the same time.
  74    */
  75   struct GNUNET_TRANSPORT_TransmitHandle *transmit_handle;
  76
  77
  78   /**
  79    * Identity of this neighbour.
  80    */
  81   struct GNUNET_PeerIdentity id;
  82
  83   /**
  84    * At what time did we reset last_sent last?
  85    */
  86   struct GNUNET_TIME_Absolute last_quota_update;
  87
  88   /**
  89    * How many bytes have we sent since the "last_quota_update"
  90    * timestamp?
  91    */
  92   uint64_t last_sent;
  93
  94   /**
  95    * Quota for outbound traffic to the neighbour in bytes/ms.
  96    */
  97   uint32_t quota_out;
  98
  99   /**
 100    * Set to GNUNET_YES if we are currently allowed to
 101    * transmit a message to the transport service for this
 102    * peer, GNUNET_NO otherwise.
 103    */
 104   int transmit_ok;
 105
 106   /**
 107    * Set to GNUNET_YES if we have received an ACK for the
 108    * given peer.  Peers that receive our HELLO always respond
 109    * with an ACK to let us know that we are successfully
 110    * communicating.  Note that a PING can not be used for this
 111    * since PINGs are only send if a HELLO address requires
 112    * confirmation (and also, PINGs are not passed to the
 113    * transport API itself).
 114    */
 115   int received_ack;
 116
 117 };
 118
 119
 120 /**
 121  * Linked list of requests from clients for our HELLO
 122  * that were deferred.
 123  */
 124 struct HelloWaitList
 125 {
 126
 127   /**
 128    * This is a linked list.
 129    */
 130   struct HelloWaitList *next;
 131
 132   /**
 133    * Reference back to our transport handle.
 134    */
 135   struct GNUNET_TRANSPORT_Handle *handle;
 136
 137   /**
 138    * Callback to call once we got our HELLO.
 139    */
 140   GNUNET_TRANSPORT_ReceiveCallback rec;
 141
 142   /**
 143    * Closure for rec.
 144    */
 145   void *rec_cls;
 146
 147   /**
 148    * When to time out (call rec with NULL).
 149    */
 150   struct GNUNET_TIME_Absolute timeout;
 151
 152   /**
 153    * Timeout task (used to trigger timeout,
 154    * cancel if we get the HELLO in time).
 155    */
 156   GNUNET_SCHEDULER_TaskIdentifier task;
 157
 158
 159 };
 160
 161
 162 /**
 163  * Opaque handle for a transmission-ready request.
 164  */
 165 struct GNUNET_TRANSPORT_TransmitHandle
 166 {
 167
 168   /**
 169    * We keep the transmit handles that are waiting for
 170    * a transport-level connection in a doubly linked list.
 171    */
 172   struct GNUNET_TRANSPORT_TransmitHandle *next;
 173
 174   /**
 175    * We keep the transmit handles that are waiting for
 176    * a transport-level connection in a doubly linked list.
 177    */
 178   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 179
 180   /**
 181    * Handle of the main transport data structure.
 182    */
 183   struct GNUNET_TRANSPORT_Handle *handle;
 184
 185   /**
 186    * Neighbour for this handle, can be NULL if the service
 187    * is not yet connected to the target.
 188    */
 189   struct NeighbourList *neighbour;
 190
 191   /**
 192    * Which peer is this transmission going to be for?  All
 193    * zeros if it is control-traffic to the service.
 194    */
 195   struct GNUNET_PeerIdentity target;
 196
 197   /**
 198    * Function to call when notify_size bytes are available
 199    * for transmission.
 200    */
 201   GNUNET_NETWORK_TransmitReadyNotify notify;
 202
 203   /**
 204    * Closure for notify.
 205    */
 206   void *notify_cls;
 207
 208   /**
 209    * transmit_ready task Id.  The task is used to introduce the
 210    * artificial delay that may be required to maintain the bandwidth
 211    * limits.  Later, this will be the ID of the "transmit_timeout"
 212    * task which is used to signal a timeout if the transmission could
 213    * not be done in a timely fashion.
 214    */
 215   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
 216
 217   /**
 218    * Timeout for this request.
 219    */
 220   struct GNUNET_TIME_Absolute timeout;
 221
 222   /**
 223    * How many bytes is our notify callback waiting for?
 224    */
 225   size_t notify_size;
 226
 227   /**
 228    * How important is this message?
 229    */
 230   unsigned int priority;
 231
 232 };
 233
 234
 235 /**
 236  * Handle for the transport service (includes all of the
 237  * state for the transport service).
 238  */
 239 struct GNUNET_TRANSPORT_Handle
 240 {
 241
 242   /**
 243    * Closure for the callbacks.
 244    */
 245   void *cls;
 246
 247   /**
 248    * Function to call for received data.
 249    */
 250   GNUNET_TRANSPORT_ReceiveCallback rec;
 251
 252   /**
 253    * function to call on connect events
 254    */
 255   GNUNET_TRANSPORT_NotifyConnect nc_cb;
 256
 257   /**
 258    * function to call on disconnect events
 259    */
 260   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
 261
 262   /**
 263    * The current HELLO message for this peer.  Updated
 264    * whenever transports change their addresses.
 265    */
 266   struct GNUNET_HELLO_Message *my_hello;
 267
 268   /**
 269    * My client connection to the transport service.
 270    */
 271   struct GNUNET_CLIENT_Connection *client;
 272
 273   /**
 274    * Handle to our registration with the client for notification.
 275    */
 276   struct GNUNET_NETWORK_TransmitHandle *network_handle;
 277
 278   /**
 279    * Linked list of transmit handles that are waiting for the
 280    * transport to connect to the respective peer.  When we
 281    * receive notification that the transport connected to a
 282    * peer, we go over this list and check if someone has already
 283    * requested a transmission to the new peer; if so, we trigger
 284    * the next step.
 285    */
 286   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
 287
 288   /**
 289    * Linked list of transmit handles that are waiting for the
 290    * transport to be ready for transmission to the respective
 291    * peer.  When we
 292    * receive notification that the transport disconnected from
 293    * a peer, we go over this list and move the entry back to
 294    * the connect_wait list.
 295    */
 296   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
 297
 298   /**
 299    * Linked list of pending requests for our HELLO.
 300    */
 301   struct HelloWaitList *hwl_head;
 302
 303   /**
 304    * My scheduler.
 305    */
 306   struct GNUNET_SCHEDULER_Handle *sched;
 307
 308   /**
 309    * My configuration.
 310    */
 311   struct GNUNET_CONFIGURATION_Handle *cfg;
 312
 313   /**
 314    * Linked list of the current neighbours of this peer.
 315    */
 316   struct NeighbourList *neighbours;
 317
 318   /**
 319    * ID of the task trying to reconnect to the
 320    * service.
 321    */
 322   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
 323
 324   /**
 325    * Delay until we try to reconnect.
 326    */
 327   struct GNUNET_TIME_Relative reconnect_delay;
 328
 329   /**
 330    * Do we currently have a transmission pending?
 331    * (schedule transmission was called but has not
 332    * yet succeeded)?
 333    */
 334   int transmission_scheduled;
 335 };
 336
 337
 338 static struct NeighbourList *
 339 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
 340                 const struct GNUNET_PeerIdentity *peer)
 341 {
 342   struct NeighbourList *pos;
 343
 344   pos = h->neighbours;
 345   while ((pos != NULL) &&
 346          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
 347     pos = pos->next;
 348   return pos;
 349 }
 350
 351
 352 /**
 353  * Schedule the task to send one message from the
 354  * connect_ready list to the service.
 355  */
 356 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
 357
 358
 359 /**
 360  * Transmit message to client...
 361  */
 362 static size_t
 363 transport_notify_ready (void *cls, size_t size, void *buf)
 364 {
 365   struct GNUNET_TRANSPORT_Handle *h = cls;
 366   struct GNUNET_TRANSPORT_TransmitHandle *th;
 367   struct NeighbourList *n;
 368   size_t ret;
 369   char *cbuf;
 370
 371   h->network_handle = NULL;
 372   h->transmission_scheduled = GNUNET_NO;
 373   if (buf == NULL)
 374     {
 375 #if DEBUG_TRANSPORT
 376       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 377                   "Could not transmit to transport service, cancelling pending requests\n");
 378 #endif
 379       th = h->connect_ready_head;
 380       if (th->next != NULL)
 381         th->next->prev = NULL;
 382       h->connect_ready_head = th->next;
 383       if (NULL != (n = th->neighbour))
 384         {
 385           GNUNET_assert (n->transmit_handle == th);
 386           n->transmit_handle = NULL;
 387         }
 388       GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
 389       GNUNET_free (th);
 390       return 0;
 391     }
 392 #if DEBUG_TRANSPORT
 393   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 394               "Ready to transmit %u bytes to transport service\n", size);
 395 #endif
 396   cbuf = buf;
 397   ret = 0;
 398   h->network_handle = NULL;
 399   h->transmission_scheduled = GNUNET_NO;
 400   do
 401     {
 402       th = h->connect_ready_head;
 403       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
 404         {
 405           /* remove existing time out task (only applies if
 406              this is not the first iteration of the loop) */
 407           GNUNET_SCHEDULER_cancel (h->sched,
 408                                    th->notify_delay_task);
 409           th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 410         }
 411       GNUNET_assert (th->notify_size <= size);
 412       if (th->next != NULL)
 413         th->next->prev = NULL;
 414       h->connect_ready_head = th->next;
 415       if (NULL != (n = th->neighbour))
 416         {
 417           GNUNET_assert (n->transmit_handle == th);
 418           n->transmit_handle = NULL;
 419         }
 420       ret += th->notify (th->notify_cls, size, &cbuf[ret]);
 421       GNUNET_free (th);
 422       if (n != NULL)
 423         n->last_sent += ret;
 424       size -= ret;
 425     }
 426   while ((h->connect_ready_head != NULL) &&
 427          (h->connect_ready_head->notify_size <= size));
 428   if (h->connect_ready_head != NULL)
 429     schedule_transmission (h);
 430 #if DEBUG_TRANSPORT
 431   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 432               "Transmitting %u bytes to transport service\n", ret);
 433 #endif
 434   return ret;
 435 }
 436
 437
 438 /**
 439  * Schedule the task to send one message from the
 440  * connect_ready list to the service.
 441  */
 442 static void
 443 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
 444 {
 445   struct GNUNET_TRANSPORT_TransmitHandle *th;
 446
 447   GNUNET_assert (NULL == h->network_handle);
 448   if (h->client == NULL)
 449     {
 450       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 451                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
 452       return; /* not yet connected */
 453     }
 454   th = h->connect_ready_head;
 455   if (th == NULL)
 456     return; /* no request pending */
 457   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
 458     {
 459       /* remove existing time out task, will be integrated
 460          with transmit_ready notification! */
 461       GNUNET_SCHEDULER_cancel (h->sched,
 462                                th->notify_delay_task);
 463       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 464     }
 465   h->transmission_scheduled = GNUNET_YES;
 466   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
 467                                                            th->notify_size,
 468                                                            GNUNET_TIME_absolute_get_remaining
 469                                                            (th->timeout),
 470                                                            &transport_notify_ready,
 471                                                            h);
 472   GNUNET_assert (NULL != h->network_handle);
 473 }
 474
 475
 476 /**
 477  * Insert the given transmit handle in the given sorted
 478  * doubly linked list based on timeout.
 479  *
 480  * @param head pointer to the head of the linked list
 481  * @param th element to insert into the list
 482  */
 483 static void
 484 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
 485                         struct GNUNET_TRANSPORT_TransmitHandle *th)
 486 {
 487   struct GNUNET_TRANSPORT_TransmitHandle *pos;
 488   struct GNUNET_TRANSPORT_TransmitHandle *prev;
 489
 490   pos = *head;
 491   prev = NULL;
 492   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
 493     {
 494       prev = pos;
 495       pos = pos->next;
 496     }
 497   if (prev == NULL)
 498     {
 499       th->next = *head;
 500       if (th->next != NULL)
 501         th->next->prev = th;
 502       *head = th;
 503     }
 504   else
 505     {
 506       th->next = pos;
 507       th->prev = prev;
 508       prev->next = th;
 509       if (pos != NULL)
 510         pos->prev = th;
 511     }
 512 }
 513
 514
 515 /**
 516  * Cancel a pending notify delay task (if pending) and also remove the
 517  * given transmit handle from whatever list is on.
 518  *
 519  * @param th handle for the transmission request to manipulate
 520  */
 521 static void
 522 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
 523 {
 524   struct GNUNET_TRANSPORT_Handle *h;
 525
 526   h = th->handle;
 527   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
 528     {
 529       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
 530       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 531     }
 532   if (th->prev == NULL)
 533     {
 534       if (th == h->connect_wait_head)
 535         h->connect_wait_head = th->next;
 536       else
 537         h->connect_ready_head = th->next;
 538     }
 539   else
 540     {
 541       th->prev->next = th->next;
 542     }
 543   if (th->next != NULL)
 544     th->next->prev = th->prev;
 545 }
 546
 547
 548 /**
 549  * Called when our transmit request timed out before any transport
 550  * reported success connecting to the desired peer or before the
 551  * transport was ready to receive.  Signal error and free
 552  * TransmitHandle.
 553  */
 554 static void
 555 transmit_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 556 {
 557   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 558
 559   th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
 560   if (th->neighbour != NULL)
 561     th->neighbour->transmit_handle = NULL;
 562 #if DEBUG_TRANSPORT
 563   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 564               "Request for transmission to peer `%s' timed out.\n",
 565               GNUNET_i2s(&th->target));
 566 #endif
 567   remove_from_any_list (th);
 568   th->notify (th->notify_cls, 0, NULL);
 569   GNUNET_free (th);
 570 }
 571
 572
 573
 574
 575 /**
 576  * Queue control request for transmission to the transport
 577  * service.
 578  *
 579  * @param size number of bytes to be transmitted
 580  * @param at_head request must be added to the head of the queue
 581  *        (otherwise request will be appended)
 582  * @param timeout how long this transmission can wait (at most)
 583  * @param notify function to call to get the content
 584  * @param notify_cls closure for notify
 585  */
 586 static void
 587 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
 588                            size_t size,
 589                            int at_head,
 590                            struct GNUNET_TIME_Relative timeout,
 591                            GNUNET_NETWORK_TransmitReadyNotify notify,
 592                            void *notify_cls)
 593 {
 594   struct GNUNET_TRANSPORT_TransmitHandle *th;
 595
 596   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
 597   th->handle = h;
 598   th->notify = notify;
 599   th->notify_cls = notify_cls;
 600   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 601   th->notify_size = size;
 602   th->notify_delay_task
 603     = GNUNET_SCHEDULER_add_delayed (h->sched,
 604                                     GNUNET_NO,
 605                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
 606                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 607                                     timeout,
 608                                     &transmit_timeout, th);
 609   if (at_head)
 610     {
 611       th->next = h->connect_ready_head;
 612       h->connect_ready_head = th;
 613       if (th->next != NULL)
 614         th->next->prev = th;
 615     }
 616   else
 617     {
 618       insert_transmit_handle (&h->connect_ready_head, th);
 619     }
 620   if (GNUNET_NO == h->transmission_scheduled)
 621     schedule_transmission (h);
 622 }
 623
 624
 625 /**
 626  * Update the quota values for the given neighbour now.
 627  */
 628 static void
 629 update_quota (struct NeighbourList *n)
 630 {
 631   struct GNUNET_TIME_Relative delta;
 632   uint64_t allowed;
 633   uint64_t remaining;
 634
 635   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
 636   allowed = delta.value * n->quota_out;
 637   if (n->last_sent < allowed)
 638     {
 639       remaining = allowed - n->last_sent;
 640       if (n->quota_out > 0)
 641         remaining /= n->quota_out;
 642       else
 643         remaining = 0;
 644       if (remaining > MAX_BANDWIDTH_CARRY)
 645         remaining = MAX_BANDWIDTH_CARRY;
 646       n->last_sent = 0;
 647       n->last_quota_update = GNUNET_TIME_absolute_get ();
 648       n->last_quota_update.value -= remaining;
 649     }
 650   else
 651     {
 652       n->last_sent -= allowed;
 653       n->last_quota_update = GNUNET_TIME_absolute_get ();
 654     }
 655 }
 656
 657
 658 struct SetQuotaContext
 659 {
 660   struct GNUNET_TRANSPORT_Handle *handle;
 661
 662   struct GNUNET_PeerIdentity target;
 663
 664   GNUNET_SCHEDULER_Task cont;
 665
 666   void *cont_cls;
 667
 668   struct GNUNET_TIME_Absolute timeout;
 669
 670   uint32_t quota_in;
 671 };
 672
 673
 674 static size_t
 675 send_set_quota (void *cls, size_t size, void *buf)
 676 {
 677   struct SetQuotaContext *sqc = cls;
 678   struct QuotaSetMessage *msg;
 679
 680   if (buf == NULL)
 681     {
 682       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 683                                          GNUNET_NO,
 684                                          sqc->cont,
 685                                          sqc->cont_cls,
 686                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
 687       GNUNET_free (sqc);
 688       return 0;
 689     }
 690 #if DEBUG_TRANSPORT
 691   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 692               "Transmitting `%s' request with respect to `%4s'.\n",
 693               "SET_QUOTA", GNUNET_i2s (&sqc->target));
 694 #endif
 695   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
 696   msg = buf;
 697   msg->header.size = htons (sizeof (struct QuotaSetMessage));
 698   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
 699   msg->quota_in = htonl (sqc->quota_in);
 700   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
 701   if (sqc->cont != NULL)
 702     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
 703                                        GNUNET_NO,
 704                                        sqc->cont,
 705                                        sqc->cont_cls,
 706                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
 707   GNUNET_free (sqc);
 708   return sizeof (struct QuotaSetMessage);
 709 }
 710
 711
 712 /**
 713  * Set the share of incoming bandwidth for the given
 714  * peer to the specified amount.
 715  *
 716  * @param handle connection to transport service
 717  * @param target who's bandwidth quota is being changed
 718  * @param quota_in incoming bandwidth quota in bytes per ms; 0 can
 719  *        be used to force all traffic to be discarded
 720  * @param quota_out outgoing bandwidth quota in bytes per ms; 0 can
 721  *        be used to force all traffic to be discarded
 722  * @param timeout how long to wait until signaling failure if
 723  *        we can not communicate the quota change
 724  * @param cont continuation to call when done, will be called
 725  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
 726  * @param cont_cls closure for continuation
 727  */
 728 void
 729 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
 730                             const struct GNUNET_PeerIdentity *target,
 731                             uint32_t quota_in,
 732                             uint32_t quota_out,
 733                             struct GNUNET_TIME_Relative timeout,
 734                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
 735 {
 736   struct NeighbourList *n;
 737   struct SetQuotaContext *sqc;
 738
 739   n = find_neighbour (handle, target);
 740   if (n != NULL)
 741     {
 742       update_quota (n);
 743       if (n->quota_out < quota_out)
 744         n->last_quota_update = GNUNET_TIME_absolute_get ();
 745       n->quota_out = quota_out;
 746     }
 747   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
 748   sqc->handle = handle;
 749   sqc->target = *target;
 750   sqc->cont = cont;
 751   sqc->cont_cls = cont_cls;
 752   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 753   sqc->quota_in = quota_in;
 754   schedule_control_transmit (handle,
 755                              sizeof (struct QuotaSetMessage),
 756                              GNUNET_NO, timeout, &send_set_quota, sqc);
 757 }
 758
 759
 760 /**
 761  * A "get_hello" request has timed out.  Signal the client
 762  * and clean up.
 763  */
 764 static void
 765 hello_wait_timeout (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
 766 {
 767   struct HelloWaitList *hwl = cls;
 768   struct HelloWaitList *pos;
 769   struct HelloWaitList *prev;
 770
 771   prev = NULL;
 772   pos = hwl->handle->hwl_head;
 773   while (pos != hwl)
 774     {
 775       GNUNET_assert (pos != NULL);
 776       prev = pos;
 777       pos = pos->next;
 778     }
 779   if (prev == NULL)
 780     hwl->handle->hwl_head = hwl->next;
 781   else
 782     prev->next = hwl->next;
 783   GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 784               _("Timeout trying to obtain `%s' from transport service.\n"),
 785               "HELLO");
 786   /* signal timeout */
 787   if (hwl->rec != NULL)
 788     hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
 789   GNUNET_free (hwl);
 790 }
 791
 792
 793 /**
 794  * Obtain the HELLO message for this peer.
 795  *
 796  * @param handle connection to transport service
 797  * @param timeout how long to wait for the HELLO
 798  * @param rec function to call with the HELLO, sender will be our peer
 799  *            identity; message and sender will be NULL on timeout
 800  *            (handshake with transport service pending/failed).
 801  *             cost estimate will be 0.
 802  * @param rec_cls closure for rec
 803  */
 804 void
 805 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
 806                             struct GNUNET_TIME_Relative timeout,
 807                             GNUNET_TRANSPORT_ReceiveCallback rec,
 808                             void *rec_cls)
 809 {
 810   struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded pk;
 811   struct GNUNET_PeerIdentity me;
 812   struct HelloWaitList *hwl;
 813
 814   if (handle->my_hello == NULL)
 815     {
 816       hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
 817       hwl->next = handle->hwl_head;
 818       handle->hwl_head = hwl;
 819       hwl->handle = handle;
 820       hwl->rec = rec;
 821       hwl->rec_cls = rec_cls;
 822       hwl->timeout = GNUNET_TIME_relative_to_absolute (timeout);
 823       hwl->task = GNUNET_SCHEDULER_add_delayed (handle->sched,
 824                                                 GNUNET_YES,
 825                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
 826                                                 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 827                                                 timeout,
 828                                                 &hello_wait_timeout, hwl);
 829       return;
 830     }
 831   GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_key (handle->my_hello, &pk));
 832   GNUNET_CRYPTO_hash (&pk,
 833                       sizeof (struct GNUNET_CRYPTO_RsaPublicKeyBinaryEncoded),
 834                       &me.hashPubKey);
 835
 836   rec (rec_cls,
 837        GNUNET_TIME_UNIT_ZERO,
 838        &me, (const struct GNUNET_MessageHeader *) handle->my_hello);
 839 }
 840
 841
 842 static size_t
 843 send_hello (void *cls, size_t size, void *buf)
 844 {
 845   struct GNUNET_MessageHeader *hello = cls;
 846   uint16_t msize;
 847
 848   if (buf == NULL)
 849     {
 850 #if DEBUG_TRANSPORT
 851       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 852                   "Timeout while trying to transmit `%s' request.\n",
 853                   "HELLO");
 854 #endif
 855       GNUNET_free (hello);
 856       return 0;
 857     }
 858 #if DEBUG_TRANSPORT
 859   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 860               "Transmitting `%s' request.\n", "HELLO");
 861 #endif
 862   msize = ntohs (hello->size);
 863   GNUNET_assert (size >= msize);
 864   memcpy (buf, hello, msize);
 865   GNUNET_free (hello);
 866   return msize;
 867 }
 868
 869
 870 /**
 871  * Offer the transport service the HELLO of another peer.  Note that
 872  * the transport service may just ignore this message if the HELLO is
 873  * malformed or useless due to our local configuration.
 874  *
 875  * @param handle connection to transport service
 876  * @param hello the hello message
 877  */
 878 void
 879 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
 880                               const struct GNUNET_MessageHeader *hello)
 881 {
 882   struct GNUNET_MessageHeader *hc;
 883   uint16_t size;
 884
 885   if (handle->client == NULL)
 886     {
 887 #if DEBUG_TRANSPORT
 888       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
 889                   "Not connected to transport service, dropping offered HELLO\n");
 890 #endif
 891       return;
 892     }
 893   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
 894   size = ntohs (hello->size);
 895   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
 896   hc = GNUNET_malloc (size);
 897   memcpy (hc, hello, size);
 898   schedule_control_transmit (handle,
 899                              size,
 900                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
 901 }
 902
 903
 904 /**
 905  * Function we use for handling incoming messages.
 906  */
 907 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
 908
 909
 910 static size_t
 911 send_start (void *cls, size_t size, void *buf)
 912 {
 913   struct GNUNET_MessageHeader *s = buf;
 914
 915   if (buf == NULL)
 916     {
 917 #if DEBUG_TRANSPORT
 918       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
 919                   "Timeout while trying to transmit `%s' request.\n",
 920                   "START");
 921 #endif
 922       return 0;
 923     }
 924 #if DEBUG_TRANSPORT
 925   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 926               "Transmitting `%s' request.\n", "START");
 927 #endif
 928   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
 929   s->size = htons (sizeof (struct GNUNET_MessageHeader));
 930   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
 931   return sizeof (struct GNUNET_MessageHeader);
 932 }
 933
 934
 935 /**
 936  * We're ready to transmit the request that the transport service
 937  * should connect to a new peer.  In addition to sending the
 938  * request, schedule the next phase for the transmission processing
 939  * that caused the connect request in the first place.
 940  */
 941 static size_t
 942 request_connect (void *cls, size_t size, void *buf)
 943 {
 944   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
 945   struct TryConnectMessage *tcm;
 946   struct GNUNET_TRANSPORT_Handle *h;
 947
 948   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
 949   h = th->handle;
 950   if (buf == NULL)
 951     {
 952 #if DEBUG_TRANSPORT
 953       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 954                   "Failed to transmit `%s' request for `%4s' to service.\n",
 955                   "TRY_CONNECT",
 956                   GNUNET_i2s(&th->target));
 957 #endif
 958       th->notify (th->notify_cls, 0, NULL);
 959       GNUNET_free (th);
 960       return 0;
 961     }
 962 #if DEBUG_TRANSPORT
 963   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
 964               "Transmitting `%s' message for `%4s'.\n",
 965               "TRY_CONNECT", GNUNET_i2s (&th->target));
 966 #endif
 967   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
 968   tcm = buf;
 969   tcm->header.size = htons (sizeof (struct TryConnectMessage));
 970   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
 971   tcm->reserved = htonl (0);
 972   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
 973   th->notify_delay_task
 974     = GNUNET_SCHEDULER_add_delayed (h->sched,
 975                                     GNUNET_NO,
 976                                     GNUNET_SCHEDULER_PRIORITY_KEEP,
 977                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
 978                                     GNUNET_TIME_absolute_get_remaining
 979                                     (th->timeout), &transmit_timeout, th);
 980   insert_transmit_handle (&h->connect_wait_head, th);
 981   return sizeof (struct TryConnectMessage);
 982 }
 983
 984
 985 /**
 986  * Schedule a request to connect to the given
 987  * neighbour (and if successful, add the specified
 988  * handle to the wait list).
 989  *
 990  * @param th handle for a request to transmit once we
 991  *        have connected
 992  */
 993 static void
 994 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
 995 {
 996   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
 997   schedule_control_transmit (th->handle,
 998                              sizeof (struct TryConnectMessage),
 999                              GNUNET_NO,
1000                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1001                              &request_connect, th);
1002 }
1003
1004
1005 /**
1006  * Remove neighbour from our list
1007  */
1008 static void
1009 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1010                   const struct GNUNET_PeerIdentity *peer)
1011 {
1012   struct NeighbourList *prev;
1013   struct NeighbourList *pos;
1014   struct GNUNET_TRANSPORT_TransmitHandle *th;
1015
1016   prev = NULL;
1017   pos = h->neighbours;
1018   while ((pos != NULL) &&
1019          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
1020     {
1021       prev = pos;
1022       pos = pos->next;
1023     }
1024   if (pos == NULL)
1025     {
1026       GNUNET_break (0);
1027       return;
1028     }
1029   if (prev == NULL)
1030     h->neighbours = pos->next;
1031   else
1032     prev->next = pos->next;
1033   if (NULL != (th = pos->transmit_handle))
1034     {
1035       pos->transmit_handle = NULL;
1036       th->neighbour = NULL;
1037       remove_from_any_list (th);
1038       try_connect (th);
1039     }
1040   if (h->nc_cb != NULL)
1041     h->nd_cb (h->cls, peer);
1042   GNUNET_free (pos);
1043 }
1044
1045
1046 /**
1047  * Try again to connect to transport service.
1048  */
1049 static void
1050 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1051 {
1052   struct GNUNET_TRANSPORT_Handle *h = cls;
1053   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1054   struct NeighbourList *n;
1055
1056   /* Forget about all neighbours that we used to be connected
1057      to */
1058   while (NULL != (n = h->neighbours))
1059     remove_neighbour (h, &n->id);
1060 #if DEBUG_TRANSPORT
1061   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1062 #endif
1063   GNUNET_assert (h->client == NULL);
1064   h->reconnect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1065   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1066   GNUNET_assert (h->client != NULL);
1067   /* make sure we don't send "START" twice,
1068      remove existing entry from queue (if present) */
1069   pos = h->connect_ready_head;
1070   while (pos != NULL)
1071     {
1072       if (pos->notify == &send_start)
1073         {
1074           if (pos->prev == NULL)
1075             h->connect_ready_head = pos->next;
1076           else
1077             pos->prev->next = pos->next;
1078           if (pos->next != NULL)
1079             pos->next->prev = pos->prev;
1080           GNUNET_assert (pos->neighbour == NULL);
1081           GNUNET_free (pos);
1082           break;
1083         }
1084       pos = pos->next;
1085     }
1086   schedule_control_transmit (h,
1087                              sizeof (struct GNUNET_MessageHeader),
1088                              GNUNET_YES,
1089                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
1090   GNUNET_CLIENT_receive (h->client,
1091                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1092 }
1093
1094
1095 /**
1096  * Function that will schedule the job that will try
1097  * to connect us again to the client.
1098  */
1099 static void
1100 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1101 {
1102 #if DEBUG_TRANSPORT
1103   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1104               "Scheduling task to reconnect to transport service in %llu ms.\n",
1105               h->reconnect_delay.value);
1106 #endif
1107   GNUNET_assert (h->client == NULL);
1108   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1109   h->reconnect_task
1110     = GNUNET_SCHEDULER_add_delayed (h->sched,
1111                                     GNUNET_NO,
1112                                     GNUNET_SCHEDULER_PRIORITY_DEFAULT,
1113                                     GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1114                                     h->reconnect_delay, &reconnect, h);
1115   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1116 }
1117
1118
1119 /**
1120  * We are connected to the respective peer, check the
1121  * bandwidth limits and schedule the transmission.
1122  */
1123 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1124
1125
1126 /**
1127  * Function called by the scheduler when the timeout
1128  * for bandwidth availablility for the target
1129  * neighbour is reached.
1130  */
1131 static void
1132 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1133 {
1134   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1135
1136   th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1137   schedule_request (th);
1138 }
1139
1140
1141 /**
1142  * Remove the given transmit handle from the wait list.  Does NOT free
1143  * it.
1144  */
1145 static void
1146 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1147 {
1148   if (th->prev == NULL)
1149     th->handle->connect_wait_head = th->next;
1150   else
1151     th->prev->next = th->next;
1152   if (th->next != NULL)
1153     th->next->prev = th->prev;
1154 }
1155
1156
1157 /**
1158  * We are connected to the respective peer, check the
1159  * bandwidth limits and schedule the transmission.
1160  */
1161 static void
1162 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1163 {
1164   struct GNUNET_TRANSPORT_Handle *h;
1165   struct GNUNET_TIME_Relative duration;
1166   struct NeighbourList *n;
1167   uint64_t available;
1168
1169   h = th->handle;
1170   n = th->neighbour;
1171   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1172     {
1173       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1174       th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1175     }
1176   /* check outgoing quota */
1177   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1178   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1179     {
1180       update_quota (n);
1181       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1182     }
1183   available = duration.value * n->quota_out;
1184   if (available < n->last_sent + th->notify_size)
1185     {
1186       /* calculate how much bandwidth we'd still need to
1187          accumulate and based on that how long we'll have
1188          to wait... */
1189       available = n->last_sent + th->notify_size - available;
1190       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1191                                                 available / n->quota_out);
1192       if (th->timeout.value <
1193           GNUNET_TIME_relative_to_absolute (duration).value)
1194         {
1195           /* signal timeout! */
1196 #if DEBUG_TRANSPORT
1197           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1198                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1199                       duration.value,
1200                       GNUNET_i2s(&th->target));
1201 #endif
1202           remove_from_wait_list (th);
1203           th->notify (th->notify_cls, 0, NULL);
1204           GNUNET_free (th);
1205           return;
1206         }
1207 #if DEBUG_TRANSPORT
1208       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1209                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1210                   GNUNET_i2s(&th->target),
1211                   duration.value);
1212 #endif
1213       th->notify_delay_task
1214         = GNUNET_SCHEDULER_add_delayed (h->sched,
1215                                         GNUNET_NO,
1216                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1217                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1218                                         duration, &transmit_ready, th);
1219       return;
1220     }
1221 #if DEBUG_TRANSPORT
1222   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1223               "Bandwidth available for transmission to `%4s'\n",
1224               GNUNET_i2s (&n->id));
1225 #endif
1226   if (GNUNET_NO == n->transmit_ok)
1227     {
1228       /* we may be ready, but transport service is not;
1229          wait for SendOkMessage or timeout */
1230 #if DEBUG_TRANSPORT
1231       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1232                   "Need to wait for transport service `%s' message\n",
1233                   "SEND_OK");
1234 #endif
1235       th->notify_delay_task
1236         = GNUNET_SCHEDULER_add_delayed (h->sched,
1237                                         GNUNET_NO,
1238                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1239                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1240                                         GNUNET_TIME_absolute_get_remaining
1241                                         (th->timeout), &transmit_timeout, th);
1242       return;
1243     }
1244   n->transmit_ok = GNUNET_NO;
1245   remove_from_wait_list (th);
1246 #if DEBUG_TRANSPORT
1247   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Moving message for `%4s' to ready list\n",
1248               GNUNET_i2s(&n->id));
1249 #endif
1250   insert_transmit_handle (&h->connect_ready_head, th);
1251   if (GNUNET_NO == h->transmission_scheduled)
1252     schedule_transmission (h);
1253 }
1254
1255
1256 /**
1257  * Add neighbour to our list
1258  */
1259 static void
1260 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1261                uint32_t quota_out,
1262                struct GNUNET_TIME_Relative latency,
1263                const struct GNUNET_PeerIdentity *pid)
1264 {
1265   struct NeighbourList *n;
1266   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1267   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1268   struct GNUNET_TRANSPORT_TransmitHandle *next;
1269
1270   /* check for duplicates */
1271   if (NULL != find_neighbour (h, pid))
1272     {
1273       GNUNET_break (0);
1274       return;
1275     }
1276 #if DEBUG_TRANSPORT
1277   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1278               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1279 #endif
1280   n = GNUNET_malloc (sizeof (struct NeighbourList));
1281   n->id = *pid;
1282   n->last_quota_update = GNUNET_TIME_absolute_get ();
1283   n->quota_out = quota_out;
1284   n->next = h->neighbours;
1285   n->transmit_ok = GNUNET_YES;
1286   h->neighbours = n;
1287   if (h->nc_cb != NULL)
1288     h->nc_cb (h->cls, &n->id, latency);
1289   prev = NULL;
1290   pos = h->connect_wait_head;
1291   while (pos != NULL)
1292     {
1293       next = pos->next;
1294       if (0 == memcmp (pid,
1295                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1296         {
1297           pos->neighbour = n;
1298           GNUNET_assert (NULL == n->transmit_handle);
1299           n->transmit_handle = pos;
1300           if (prev == NULL)
1301             h->connect_wait_head = next;
1302           else
1303             prev->next = next;
1304           if (GNUNET_YES == n->received_ack)
1305             {
1306 #if DEBUG_TRANSPORT
1307               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1308                           "Found pending request for `%4s' will trigger it now.\n",
1309                           GNUNET_i2s (&pos->target));
1310 #endif
1311               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1312                 {
1313                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1314                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1315                 }
1316               schedule_request (pos);
1317             }
1318           else
1319             {
1320 #if DEBUG_TRANSPORT
1321               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1322                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1323                           GNUNET_i2s (&pos->target),
1324                           "ACK");
1325 #endif
1326             }
1327           break;
1328         }
1329       prev = pos;
1330       pos = next;
1331     }
1332 }
1333
1334
1335 /**
1336  * Connect to the transport service.  Note that the connection may
1337  * complete (or fail) asynchronously.
1338  *
1339
1340  * @param sched scheduler to use
1341  * @param cfg configuration to use
1342  * @param cls closure for the callbacks
1343  * @param rec receive function to call
1344  * @param nc function to call on connect events
1345  * @param dc function to call on disconnect events
1346  */
1347 struct GNUNET_TRANSPORT_Handle *
1348 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1349                           struct GNUNET_CONFIGURATION_Handle *cfg,
1350                           void *cls,
1351                           GNUNET_TRANSPORT_ReceiveCallback rec,
1352                           GNUNET_TRANSPORT_NotifyConnect nc,
1353                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1354 {
1355   struct GNUNET_TRANSPORT_Handle *ret;
1356
1357   GNUNET_ARM_start_service ("peerinfo",
1358                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1359   GNUNET_ARM_start_service ("transport",
1360                             cfg, sched, START_SERVICE_TIMEOUT, NULL, NULL);
1361   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1362   ret->sched = sched;
1363   ret->cfg = cfg;
1364   ret->cls = cls;
1365   ret->rec = rec;
1366   ret->nc_cb = nc;
1367   ret->nd_cb = nd;
1368   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1369   schedule_reconnect (ret);
1370   return ret;
1371 }
1372
1373
1374 /**
1375  * These stop activities must be run in a fresh
1376  * scheduler that is NOT in shutdown mode.
1377  */
1378 static void
1379 stop_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1380 {
1381   struct GNUNET_TRANSPORT_Handle *handle = cls;
1382   GNUNET_ARM_stop_service ("transport",
1383                            handle->cfg,
1384                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1385   GNUNET_ARM_stop_service ("peerinfo",
1386                            handle->cfg,
1387                            tc->sched, STOP_SERVICE_TIMEOUT, NULL, NULL);
1388 }
1389
1390
1391 /**
1392  * Disconnect from the transport service.
1393  */
1394 void
1395 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1396 {
1397   struct GNUNET_TRANSPORT_TransmitHandle *th;
1398   struct NeighbourList *n;
1399   struct HelloWaitList *hwl;
1400   struct GNUNET_CLIENT_Connection *client;
1401
1402 #if DEBUG_TRANSPORT
1403   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1404 #endif
1405   while (NULL != (th = handle->connect_ready_head))
1406     {
1407       handle->connect_ready_head = th->next;
1408       th->notify (th->notify_cls, 0, NULL);
1409       GNUNET_free (th);
1410     }
1411   while (NULL != (th = handle->connect_wait_head))
1412     {
1413       handle->connect_wait_head = th->next;
1414       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1415         {
1416           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1417           th->notify_delay_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1418         }
1419       th->notify (th->notify_cls, 0, NULL);
1420       GNUNET_free (th);
1421     }
1422   while (NULL != (n = handle->neighbours))
1423     {
1424       handle->neighbours = n->next;
1425       GNUNET_free (n);
1426     }
1427   while (NULL != (hwl = handle->hwl_head))
1428     {
1429       handle->hwl_head = hwl->next;
1430       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1431       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1432                   _("Disconnect while trying to obtain `%s' from transport service.\n"),
1433                   "HELLO");
1434       if (hwl->rec != NULL)
1435         hwl->rec (hwl->rec_cls, GNUNET_TIME_UNIT_ZERO, NULL, NULL);
1436       GNUNET_free (hwl);
1437     }
1438   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_PREREQUISITE_TASK)
1439     {
1440       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1441       handle->reconnect_task = GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1442     }
1443   GNUNET_free_non_null (handle->my_hello);
1444   handle->my_hello = NULL;
1445   GNUNET_SCHEDULER_run (&stop_task, handle);
1446   if (NULL != (client = handle->client))
1447     {
1448 #if DEBUG_TRANSPORT
1449       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1450                   "Disconnecting from transport service for good.\n");
1451 #endif
1452       handle->client = NULL;
1453       GNUNET_CLIENT_disconnect (client);
1454     }
1455   if (client == NULL)
1456     GNUNET_free (handle);
1457 }
1458
1459
1460 /**
1461  * Type of a function to call when we receive a message
1462  * from the service.
1463  *
1464  * @param cls closure
1465  * @param msg message received, NULL on timeout or fatal error
1466  */
1467 static void
1468 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1469 {
1470   struct GNUNET_TRANSPORT_Handle *h = cls;
1471   const struct DisconnectInfoMessage *dim;
1472   const struct ConnectInfoMessage *cim;
1473   const struct InboundMessage *im;
1474   const struct GNUNET_MessageHeader *imm;
1475   const struct SendOkMessage *okm;
1476   struct HelloWaitList *hwl;
1477   struct NeighbourList *n;
1478   struct GNUNET_PeerIdentity me;
1479   struct GNUNET_TRANSPORT_TransmitHandle *th;
1480   uint16_t size;
1481
1482   if ((msg == NULL) || (h->client == NULL))
1483     {
1484       if (h->client != NULL)
1485         {
1486 #if DEBUG_TRANSPORT
1487           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1488                       "Error receiving from transport service, disconnecting temporarily.\n");
1489 #endif
1490           if (h->network_handle != NULL)
1491             {
1492               GNUNET_NETWORK_notify_transmit_ready_cancel (h->network_handle);
1493               h->network_handle = NULL;
1494               h->transmission_scheduled = GNUNET_NO;
1495               th = h->connect_ready_head;
1496               /* add timeout again, we cancelled the transmit_ready task! */
1497               GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_PREREQUISITE_TASK);
1498               th->notify_delay_task
1499                 = GNUNET_SCHEDULER_add_delayed (h->sched,
1500                                                 GNUNET_NO,
1501                                                 GNUNET_SCHEDULER_PRIORITY_KEEP,
1502                                                 GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1503                                                 GNUNET_TIME_absolute_get_remaining(th->timeout),
1504                                                 &transmit_timeout,
1505                                                 th);
1506             }
1507           GNUNET_CLIENT_disconnect (h->client);
1508           h->client = NULL;
1509           schedule_reconnect (h);
1510         }
1511       else
1512         {
1513           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1514              finish clean up work! */
1515           GNUNET_free (h);
1516         }
1517       return;
1518     }
1519   GNUNET_CLIENT_receive (h->client,
1520                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1521   size = ntohs (msg->size);
1522   switch (ntohs (msg->type))
1523     {
1524     case GNUNET_MESSAGE_TYPE_HELLO:
1525       if (GNUNET_OK !=
1526           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1527                                &me))
1528         {
1529           GNUNET_break (0);
1530           break;
1531         }
1532 #if DEBUG_TRANSPORT
1533       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1534                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1535                   "HELLO", GNUNET_i2s (&me));
1536 #endif
1537       GNUNET_free_non_null (h->my_hello);
1538       h->my_hello = NULL;
1539       if (size < sizeof (struct GNUNET_MessageHeader))
1540         {
1541           GNUNET_break (0);
1542           break;
1543         }
1544       h->my_hello = GNUNET_malloc (size);
1545       memcpy (h->my_hello, msg, size);
1546       while (NULL != (hwl = h->hwl_head))
1547         {
1548           h->hwl_head = hwl->next;
1549           GNUNET_SCHEDULER_cancel (h->sched, hwl->task);
1550           GNUNET_TRANSPORT_get_hello (h,
1551                                       GNUNET_TIME_UNIT_ZERO,
1552                                       hwl->rec, hwl->rec_cls);
1553           GNUNET_free (hwl);
1554         }
1555       break;
1556     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1557       if (size != sizeof (struct ConnectInfoMessage))
1558         {
1559           GNUNET_break (0);
1560           break;
1561         }
1562       cim = (const struct ConnectInfoMessage *) msg;
1563 #if DEBUG_TRANSPORT
1564       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1565                   "Receiving `%s' message for `%4s'.\n",
1566                   "CONNECT", GNUNET_i2s (&cim->id));
1567 #endif
1568       add_neighbour (h,
1569                      ntohl (cim->quota_out),
1570                      GNUNET_TIME_relative_ntoh (cim->latency), &cim->id);
1571       break;
1572     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1573       if (size != sizeof (struct DisconnectInfoMessage))
1574         {
1575           GNUNET_break (0);
1576           break;
1577         }
1578       dim = (const struct DisconnectInfoMessage *) msg;
1579 #if DEBUG_TRANSPORT
1580       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1581                   "Receiving `%s' message for `%4s'.\n",
1582                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1583 #endif
1584       remove_neighbour (h, &dim->peer);
1585       break;
1586     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1587       if (size != sizeof (struct SendOkMessage))
1588         {
1589           GNUNET_break (0);
1590           break;
1591         }
1592       okm = (const struct SendOkMessage *) msg;
1593 #if DEBUG_TRANSPORT
1594       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1595                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1596                   ntohl(okm->success) == GNUNET_OK ? "succeeded" : "failed");
1597 #endif
1598       n = find_neighbour (h, &okm->peer);
1599       GNUNET_assert (n != NULL);
1600       n->transmit_ok = GNUNET_YES;
1601       if (n->transmit_handle != NULL)
1602         {
1603 #if DEBUG_TRANSPORT
1604           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1605                       "Processing pending message\n");
1606 #endif
1607           GNUNET_SCHEDULER_cancel (h->sched,
1608                                    n->transmit_handle->notify_delay_task);
1609           n->transmit_handle->notify_delay_task =
1610             GNUNET_SCHEDULER_NO_PREREQUISITE_TASK;
1611           GNUNET_assert (GNUNET_YES == n->received_ack);
1612           schedule_request (n->transmit_handle);
1613         }
1614       break;
1615     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1616 #if DEBUG_TRANSPORT
1617       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1618                   "Receiving `%s' message.\n", "RECV");
1619 #endif
1620       if (size <
1621           sizeof (struct InboundMessage) +
1622           sizeof (struct GNUNET_MessageHeader))
1623         {
1624           GNUNET_break (0);
1625           break;
1626         }
1627       im = (const struct InboundMessage *) msg;
1628       imm = (const struct GNUNET_MessageHeader *) &im[1];
1629       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1630         {
1631           GNUNET_break (0);
1632           break;
1633         }
1634       switch (ntohs (imm->type))
1635         {
1636         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1637 #if DEBUG_TRANSPORT
1638           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1639                       "Receiving `%s' message from `%4s'.\n",
1640                       "ACK", GNUNET_i2s (&im->peer));
1641 #endif
1642           n = find_neighbour (h, &im->peer);
1643           if (n == NULL)
1644             {
1645               GNUNET_break (0);
1646               break;
1647             }
1648           if (n->received_ack == GNUNET_NO)
1649             {
1650               n->received_ack = GNUNET_YES;
1651               if (NULL != n->transmit_handle)
1652                 {
1653 #if DEBUG_TRANSPORT
1654                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1655                               "Peer connected, scheduling delayed message for deliverery now.\n");
1656 #endif
1657                   schedule_request (n->transmit_handle);
1658                 }
1659             }
1660           break;
1661         default:
1662 #if DEBUG_TRANSPORT
1663           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1664                       "Received message of type %u from `%4s'.\n",
1665                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1666 #endif
1667           if (h->rec != NULL)
1668             h->rec (h->cls,
1669                     GNUNET_TIME_relative_ntoh (im->latency), &im->peer, imm);
1670           break;
1671         }
1672       break;
1673     default:
1674       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1675                   _
1676                   ("Received unexpected message of type %u in %s:%u\n"),
1677                   ntohs (msg->type), __FILE__, __LINE__);
1678       GNUNET_break (0);
1679       break;
1680     }
1681 }
1682
1683
1684 struct ClientTransmitWrapper
1685 {
1686   GNUNET_NETWORK_TransmitReadyNotify notify;
1687   void *notify_cls;
1688   struct GNUNET_TRANSPORT_TransmitHandle *th;
1689 };
1690
1691
1692 /**
1693  * Transmit message of a client destined for another
1694  * peer to the service.
1695  */
1696 static size_t
1697 client_notify_wrapper (void *cls, size_t size, void *buf)
1698 {
1699   struct ClientTransmitWrapper *ctw = cls;
1700   struct OutboundMessage *obm;
1701   struct GNUNET_MessageHeader *hdr;
1702   size_t ret;
1703
1704   if (size == 0)
1705     {
1706 #if DEBUG_TRANSPORT
1707       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1708                   "Transmission request could not be satisfied.\n");
1709 #endif
1710       ret = ctw->notify (ctw->notify_cls, 0, NULL);
1711       GNUNET_assert (ret == 0);
1712       GNUNET_free (ctw);
1713       return 0;
1714     }
1715   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1716   obm = buf;
1717   ret = ctw->notify (ctw->notify_cls,
1718                      size - sizeof (struct OutboundMessage),
1719                      (void *) &obm[1]);
1720   if (ret == 0)
1721     {
1722       /* Need to reset flag, no SEND means no SEND_OK! */
1723       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1724       GNUNET_free (ctw);
1725       return 0;
1726     }
1727   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1728   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1729   GNUNET_assert (ntohs (hdr->size) == ret);
1730   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1731                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1732 #if DEBUG_TRANSPORT
1733   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1734               "Transmitting `%s' message with data for `%4s'\n",
1735               "SEND", GNUNET_i2s (&ctw->th->target));
1736 #endif
1737   ret += sizeof (struct OutboundMessage);
1738   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1739   obm->header.size = htons (ret);
1740   obm->priority = htonl (ctw->th->priority);
1741   obm->peer = ctw->th->target;
1742   GNUNET_free (ctw);
1743   return ret;
1744 }
1745
1746
1747
1748 /**
1749  * Check if we could queue a message of the given size for
1750  * transmission.  The transport service will take both its
1751  * internal buffers and bandwidth limits imposed by the
1752  * other peer into consideration when answering this query.
1753  *
1754  * @param handle connection to transport service
1755  * @param target who should receive the message
1756  * @param size how big is the message we want to transmit?
1757  * @param priority how important is the message?
1758  * @param timeout after how long should we give up (and call
1759  *        notify with buf NULL and size 0)?
1760  * @param notify function to call when we are ready to
1761  *        send such a message
1762  * @param notify_cls closure for notify
1763  * @return NULL if someone else is already waiting to be notified
1764  *         non-NULL if the notify callback was queued (can be used to cancel
1765  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1766  */
1767 struct GNUNET_TRANSPORT_TransmitHandle *
1768 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1769                                         *handle,
1770                                         const struct GNUNET_PeerIdentity
1771                                         *target, size_t size,
1772                                         unsigned int priority,
1773                                         struct GNUNET_TIME_Relative timeout,
1774                                         GNUNET_NETWORK_TransmitReadyNotify
1775                                         notify, void *notify_cls)
1776 {
1777   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1778   struct GNUNET_TRANSPORT_TransmitHandle *th;
1779   struct NeighbourList *n;
1780   struct ClientTransmitWrapper *ctw;
1781
1782   if (size + sizeof (struct OutboundMessage) >=
1783       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1784     {
1785       GNUNET_break (0);
1786       return NULL;
1787     }
1788 #if DEBUG_TRANSPORT
1789   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1790               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1791               size, GNUNET_i2s (target));
1792 #endif
1793   n = find_neighbour (handle, target);
1794   if ( (n != NULL) &&
1795        (n->transmit_handle != NULL) )
1796     return NULL; /* already have a request pending for this peer! */
1797   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1798   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1799   ctw->notify = notify;
1800   ctw->notify_cls = notify_cls;
1801   ctw->th = th;
1802   th->handle = handle;
1803   th->neighbour = n;
1804   th->target = *target;
1805   th->notify = &client_notify_wrapper;
1806   th->notify_cls = ctw;
1807   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1808   th->notify_size = size + sizeof (struct OutboundMessage);
1809   th->priority = priority;
1810   if (NULL == n)
1811     {
1812       pos = handle->connect_wait_head;
1813       while (pos != NULL)
1814         {
1815           GNUNET_assert (0 != memcmp (target,
1816                                       &pos->target,
1817                                       sizeof (struct GNUNET_PeerIdentity)));
1818           pos = pos->next;
1819         }
1820 #if DEBUG_TRANSPORT
1821       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1822                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1823 #endif
1824       try_connect (th);
1825       return th;
1826     }
1827
1828 #if DEBUG_TRANSPORT
1829   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1830               "Transmission request queued for transmission to transport service.\n");
1831 #endif
1832   GNUNET_assert (NULL == n->transmit_handle);
1833   n->transmit_handle = th;
1834   if (GNUNET_YES != n->received_ack)
1835     {
1836 #if DEBUG_TRANSPORT
1837       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1838                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1839                   GNUNET_i2s (target), timeout.value);
1840 #endif
1841       th->notify_delay_task
1842         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1843                                         GNUNET_NO,
1844                                         GNUNET_SCHEDULER_PRIORITY_KEEP,
1845                                         GNUNET_SCHEDULER_NO_PREREQUISITE_TASK,
1846                                         timeout, &transmit_timeout, th);
1847       return th;
1848     }
1849
1850 #if DEBUG_TRANSPORT
1851   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1852               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1853               GNUNET_i2s (target));
1854 #endif
1855   schedule_request (th);
1856   return th;
1857 }
1858
1859
1860 /**
1861  * Cancel the specified transmission-ready
1862  * notification.
1863  */
1864 void
1865 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1866                                                GNUNET_TRANSPORT_TransmitHandle
1867                                                *th)
1868 {
1869   struct GNUNET_TRANSPORT_Handle *h;
1870
1871 #if DEBUG_TRANSPORT
1872   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1873               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1874               th->notify_size - sizeof(struct OutboundMessage),
1875               GNUNET_i2s (&th->target));
1876 #endif
1877   GNUNET_assert (th->notify == &client_notify_wrapper);
1878   remove_from_any_list (th);
1879   h = th->handle;
1880   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1881     {
1882       GNUNET_NETWORK_notify_transmit_ready_cancel (h->network_handle);
1883       h->network_handle = NULL;
1884       h->transmission_scheduled = GNUNET_NO;
1885     }
1886   GNUNET_free (th->notify_cls);
1887   GNUNET_free (th);
1888 }
1889
1890
1891 /* end of transport_api.c */