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