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[oweals/gnunet.git] / 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 #include "platform.h"
27 #include "gnunet_client_lib.h"
28 #include "gnunet_arm_service.h"
29 #include "gnunet_hello_lib.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_server_lib.h"
32 #include "gnunet_time_lib.h"
33 #include "gnunet_transport_service.h"
34 #include "transport.h"
35
36 /**
37  * After how long do we give up on transmitting a HELLO
38  * to the service?
39  */
40 #define OFFER_HELLO_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 30)
41
42 /**
43  * After how long do we automatically retry an unsuccessful
44  * CONNECT request?
45  */
46 #define CONNECT_RETRY_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 750)
47
48 /**
49  * How long should ARM wait when starting up the
50  * transport service before reporting back?
51  */
52 #define START_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
53
54 /**
55  * How long should ARM wait when stopping the
56  * transport service before reporting back?
57  */
58 #define STOP_SERVICE_TIMEOUT GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS, 5)
59
60 /**
61  * Entry in linked list of all of our current neighbours.
62  */
63 struct NeighbourList
64 {
65
66   /**
67    * This is a linked list.
68    */
69   struct NeighbourList *next;
70
71   /**
72    * Active transmit handle, can be NULL.  Used to move
73    * from ready to wait list on disconnect and to block
74    * two transmissions to the same peer from being scheduled
75    * at the same time.
76    */
77   struct GNUNET_TRANSPORT_TransmitHandle *transmit_handle;
78
79   /**
80    * Identity of this neighbour.
81    */
82   struct GNUNET_PeerIdentity id;
83
84   /**
85    * At what time did we reset last_sent last?
86    */
87   struct GNUNET_TIME_Absolute last_quota_update;
88
89   /**
90    * How many bytes have we sent since the "last_quota_update"
91    * timestamp?
92    */
93   uint64_t last_sent;
94
95   /**
96    * Quota for outbound traffic to the neighbour in bytes/ms.
97    */
98   uint32_t quota_out;
99
100   /**
101    * Set to GNUNET_YES if we are currently allowed to
102    * transmit a message to the transport service for this
103    * peer, GNUNET_NO otherwise.
104    */
105   int transmit_ok;
106
107   /**
108    * Set to GNUNET_YES if we have received an ACK for the
109    * given peer.  Peers that receive our HELLO always respond
110    * with an ACK to let us know that we are successfully
111    * communicating.  Note that a PING can not be used for this
112    * since PINGs are only send if a HELLO address requires
113    * confirmation (and also, PINGs are not passed to the
114    * transport API itself).
115    */
116   int received_ack;
117
118 };
119
120
121 /**
122  * Linked list of requests from clients for our HELLO
123  * that were deferred.
124  */
125 struct HelloWaitList
126 {
127
128   /**
129    * This is a linked list.
130    */
131   struct HelloWaitList *next;
132
133   /**
134    * Reference back to our transport handle.
135    */
136   struct GNUNET_TRANSPORT_Handle *handle;
137
138   /**
139    * Callback to call once we got our HELLO.
140    */
141   GNUNET_TRANSPORT_HelloUpdateCallback rec;
142
143   /**
144    * Closure for rec.
145    */
146   void *rec_cls;
147
148   /**
149    * When to time out (call rec with NULL).
150    */
151   struct GNUNET_TIME_Absolute timeout;
152
153   /**
154    * Timeout task (used to trigger timeout,
155    * cancel if we get the HELLO in time).
156    */
157   GNUNET_SCHEDULER_TaskIdentifier task;
158
159
160 };
161
162
163 /**
164  * Opaque handle for a transmission-ready request.
165  */
166 struct GNUNET_TRANSPORT_TransmitHandle
167 {
168
169   /**
170    * We keep the transmit handles that are waiting for
171    * a transport-level connection in a doubly linked list.
172    */
173   struct GNUNET_TRANSPORT_TransmitHandle *next;
174
175   /**
176    * We keep the transmit handles that are waiting for
177    * a transport-level connection in a doubly linked list.
178    */
179   struct GNUNET_TRANSPORT_TransmitHandle *prev;
180
181   /**
182    * Handle of the main transport data structure.
183    */
184   struct GNUNET_TRANSPORT_Handle *handle;
185
186   /**
187    * Neighbour for this handle, can be NULL if the service
188    * is not yet connected to the target.
189    */
190   struct NeighbourList *neighbour;
191
192   /**
193    * Which peer is this transmission going to be for?  All
194    * zeros if it is control-traffic to the service.
195    */
196   struct GNUNET_PeerIdentity target;
197
198   /**
199    * Function to call when notify_size bytes are available
200    * for transmission.
201    */
202   GNUNET_CONNECTION_TransmitReadyNotify notify;
203
204   /**
205    * Closure for notify.
206    */
207   void *notify_cls;
208
209   /**
210    * transmit_ready task Id.  The task is used to introduce the
211    * artificial delay that may be required to maintain the bandwidth
212    * limits.  Later, this will be the ID of the "transmit_timeout"
213    * task which is used to signal a timeout if the transmission could
214    * not be done in a timely fashion.
215    */
216   GNUNET_SCHEDULER_TaskIdentifier notify_delay_task;
217
218   /**
219    * Timeout for this request.
220    */
221   struct GNUNET_TIME_Absolute timeout;
222
223   /**
224    * How many bytes is our notify callback waiting for?
225    */
226   size_t notify_size;
227
228   /**
229    * How important is this message?
230    */
231   unsigned int priority;
232
233 };
234
235
236 /**
237  * Handle for the transport service (includes all of the
238  * state for the transport service).
239  */
240 struct GNUNET_TRANSPORT_Handle
241 {
242
243   /**
244    * Closure for the callbacks.
245    */
246   void *cls;
247
248   /**
249    * Function to call for received data.
250    */
251   GNUNET_TRANSPORT_ReceiveCallback rec;
252
253   /**
254    * function to call on connect events
255    */
256   GNUNET_TRANSPORT_NotifyConnect nc_cb;
257
258   /**
259    * function to call on disconnect events
260    */
261   GNUNET_TRANSPORT_NotifyDisconnect nd_cb;
262
263   /**
264    * The current HELLO message for this peer.  Updated
265    * whenever transports change their addresses.
266    */
267   struct GNUNET_HELLO_Message *my_hello;
268
269   /**
270    * My client connection to the transport service.
271    */
272   struct GNUNET_CLIENT_Connection *client;
273
274   /**
275    * Handle to our registration with the client for notification.
276    */
277   struct GNUNET_CLIENT_TransmitHandle *network_handle;
278
279   /**
280    * Linked list of transmit handles that are waiting for the
281    * transport to connect to the respective peer.  When we
282    * receive notification that the transport connected to a
283    * peer, we go over this list and check if someone has already
284    * requested a transmission to the new peer; if so, we trigger
285    * the next step.
286    */
287   struct GNUNET_TRANSPORT_TransmitHandle *connect_wait_head;
288
289   /**
290    * Linked list of transmit handles that are waiting for the
291    * transport to be ready for transmission to the respective
292    * peer.  When we
293    * receive notification that the transport disconnected from
294    * a peer, we go over this list and move the entry back to
295    * the connect_wait list.
296    */
297   struct GNUNET_TRANSPORT_TransmitHandle *connect_ready_head;
298
299   /**
300    * Linked list of pending requests for our HELLO.
301    */
302   struct HelloWaitList *hwl_head;
303
304   /**
305    * My scheduler.
306    */
307   struct GNUNET_SCHEDULER_Handle *sched;
308
309   /**
310    * My configuration.
311    */
312   const struct GNUNET_CONFIGURATION_Handle *cfg;
313
314   /**
315    * Linked list of the current neighbours of this peer.
316    */
317   struct NeighbourList *neighbours;
318
319   /**
320    * ID of the task trying to reconnect to the
321    * service.
322    */
323   GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
324
325   /**
326    * Delay until we try to reconnect.
327    */
328   struct GNUNET_TIME_Relative reconnect_delay;
329
330   /**
331    * Do we currently have a transmission pending?
332    * (schedule transmission was called but has not
333    * yet succeeded)?
334    */
335   int transmission_scheduled;
336 };
337
338
339 static struct NeighbourList *
340 find_neighbour (struct GNUNET_TRANSPORT_Handle *h,
341                 const struct GNUNET_PeerIdentity *peer)
342 {
343   struct NeighbourList *pos;
344
345   pos = h->neighbours;
346   while ((pos != NULL) &&
347          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
348     pos = pos->next;
349   return pos;
350 }
351
352
353 /**
354  * Schedule the task to send one message from the
355  * connect_ready list to the service.
356  */
357 static void schedule_transmission (struct GNUNET_TRANSPORT_Handle *h);
358
359
360 /**
361  * Transmit message to client...
362  */
363 static size_t
364 transport_notify_ready (void *cls, size_t size, void *buf)
365 {
366   struct GNUNET_TRANSPORT_Handle *h = cls;
367   struct GNUNET_TRANSPORT_TransmitHandle *th;
368   struct NeighbourList *n;
369   size_t ret;
370   char *cbuf;
371
372   h->network_handle = NULL;
373   h->transmission_scheduled = GNUNET_NO;
374   if (buf == NULL)
375     {
376 #if DEBUG_TRANSPORT
377       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
378                   "Could not transmit to transport service, cancelling pending requests\n");
379 #endif
380       th = h->connect_ready_head;
381       if (th->next != NULL)
382         th->next->prev = NULL;
383       h->connect_ready_head = th->next;
384       if (NULL != (n = th->neighbour))
385         {
386           GNUNET_assert (n->transmit_handle == th);
387           n->transmit_handle = NULL;
388         }
389       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
390         {
391           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
392           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
393         }
394       if (NULL != th->notify)
395         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
396       GNUNET_free (th);
397       if (h->connect_ready_head != NULL)
398         schedule_transmission (h);      /* FIXME: is this ok? */
399       return 0;
400     }
401 #if DEBUG_TRANSPORT
402   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
403               "Ready to transmit %u bytes to transport service\n", size);
404 #endif
405   cbuf = buf;
406   ret = 0;
407   h->network_handle = NULL;
408   h->transmission_scheduled = GNUNET_NO;
409   while ((h->connect_ready_head != NULL) &&
410          (h->connect_ready_head->notify_size <= size))
411     {
412       th = h->connect_ready_head;
413       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
414         {
415           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
416           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
417         }
418       GNUNET_assert (th->notify_size <= size);
419       if (th->next != NULL)
420         th->next->prev = NULL;
421       h->connect_ready_head = th->next;
422       if (NULL != (n = th->neighbour))
423         {
424           GNUNET_assert (n->transmit_handle == th);
425           n->transmit_handle = NULL;
426         }
427       if (NULL != th->notify)
428         ret += th->notify (th->notify_cls, size, &cbuf[ret]);
429       GNUNET_free (th);
430       if (n != NULL)
431         n->last_sent += ret;
432       size -= ret;
433     }
434   if (h->connect_ready_head != NULL)
435     schedule_transmission (h);
436 #if DEBUG_TRANSPORT
437   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
438               "Transmitting %u bytes to transport service\n", ret);
439 #endif
440   return ret;
441 }
442
443
444 /**
445  * Schedule the task to send one message from the
446  * connect_ready list to the service.
447  */
448 static void
449 schedule_transmission (struct GNUNET_TRANSPORT_Handle *h)
450 {
451   struct GNUNET_TRANSPORT_TransmitHandle *th;
452
453   GNUNET_assert (NULL == h->network_handle);
454   if (h->client == NULL)
455     {
456       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
457                   "Could not yet schedule transmission: we are not yet connected to the transport service!\n");
458       return;                   /* not yet connected */
459     }
460   th = h->connect_ready_head;
461   if (th == NULL)
462     return;                     /* no request pending */
463   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
464     {
465       /* remove existing time out task, will be integrated
466          with transmit_ready notification! */
467       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
468       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
469     }
470   h->transmission_scheduled = GNUNET_YES;
471   h->network_handle = GNUNET_CLIENT_notify_transmit_ready (h->client,
472                                                            th->notify_size,
473                                                            GNUNET_TIME_absolute_get_remaining
474                                                            (th->timeout),
475                                                            GNUNET_NO,
476                                                            &transport_notify_ready,
477                                                            h);
478   GNUNET_assert (NULL != h->network_handle);
479 }
480
481
482 /**
483  * Insert the given transmit handle in the given sorted
484  * doubly linked list based on timeout.
485  *
486  * @param head pointer to the head of the linked list
487  * @param th element to insert into the list
488  */
489 static void
490 insert_transmit_handle (struct GNUNET_TRANSPORT_TransmitHandle **head,
491                         struct GNUNET_TRANSPORT_TransmitHandle *th)
492 {
493   struct GNUNET_TRANSPORT_TransmitHandle *pos;
494   struct GNUNET_TRANSPORT_TransmitHandle *prev;
495
496   pos = *head;
497   prev = NULL;
498   while ((pos != NULL) && (pos->timeout.value < th->timeout.value))
499     {
500       prev = pos;
501       pos = pos->next;
502     }
503   if (prev == NULL)
504     {
505       th->next = *head;
506       if (th->next != NULL)
507         th->next->prev = th;
508       *head = th;
509     }
510   else
511     {
512       th->next = pos;
513       th->prev = prev;
514       prev->next = th;
515       if (pos != NULL)
516         pos->prev = th;
517     }
518 }
519
520
521 /**
522  * Cancel a pending notify delay task (if pending) and also remove the
523  * given transmit handle from whatever list is on.
524  *
525  * @param th handle for the transmission request to manipulate
526  */
527 static void
528 remove_from_any_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
529 {
530   struct GNUNET_TRANSPORT_Handle *h;
531
532   h = th->handle;
533   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
534     {
535       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
536       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
537     }
538   if (th->prev == NULL)
539     {
540       if (th == h->connect_wait_head)
541         h->connect_wait_head = th->next;
542       else
543         h->connect_ready_head = th->next;
544     }
545   else
546     {
547       th->prev->next = th->next;
548     }
549   if (th->next != NULL)
550     th->next->prev = th->prev;
551 }
552
553
554 /**
555  * Schedule a request to connect to the given
556  * neighbour (and if successful, add the specified
557  * handle to the wait list).
558  *
559  * @param th handle for a request to transmit once we
560  *        have connected
561  */
562 static void try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th);
563
564
565 /**
566  * Called when our transmit request timed out before any transport
567  * reported success connecting to the desired peer or before the
568  * transport was ready to receive.  Signal error and free
569  * TransmitHandle.
570  */
571 static void
572 peer_transmit_timeout (void *cls,
573                        const struct GNUNET_SCHEDULER_TaskContext *tc)
574 {
575   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
576
577   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
578   if (th->neighbour != NULL)
579     th->neighbour->transmit_handle = NULL;
580 #if DEBUG_TRANSPORT
581   GNUNET_log (GNUNET_ERROR_TYPE_INFO,
582               "Request for transmission to peer `%s' timed out.\n",
583               GNUNET_i2s (&th->target));
584 #endif
585   remove_from_any_list (th);
586   if (NULL != th->notify)
587     th->notify (th->notify_cls, 0, NULL);
588   GNUNET_free (th);
589 }
590
591
592
593
594 /**
595  * Queue control request for transmission to the transport
596  * service.
597  *
598  * @param h handle to the transport service
599  * @param size number of bytes to be transmitted
600  * @param at_head request must be added to the head of the queue
601  *        (otherwise request will be appended)
602  * @param timeout how long this transmission can wait (at most)
603  * @param notify function to call to get the content
604  * @param notify_cls closure for notify
605  */
606 static void
607 schedule_control_transmit (struct GNUNET_TRANSPORT_Handle *h,
608                            size_t size,
609                            int at_head,
610                            struct GNUNET_TIME_Relative timeout,
611                            GNUNET_CONNECTION_TransmitReadyNotify notify,
612                            void *notify_cls)
613 {
614   struct GNUNET_TRANSPORT_TransmitHandle *th;
615
616 #if DEBUG_TRANSPORT
617   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
618               "Control transmit of %u bytes within %llums requested\n",
619               size, (unsigned long long) timeout.value);
620 #endif
621   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
622   th->handle = h;
623   th->notify = notify;
624   th->notify_cls = notify_cls;
625   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
626   th->notify_size = size;
627   th->notify_delay_task
628     = GNUNET_SCHEDULER_add_delayed (h->sched,
629                                     timeout, &peer_transmit_timeout, th);
630   if (at_head)
631     {
632       th->next = h->connect_ready_head;
633       h->connect_ready_head = th;
634       if (th->next != NULL)
635         th->next->prev = th;
636     }
637   else
638     {
639       insert_transmit_handle (&h->connect_ready_head, th);
640     }
641   if (GNUNET_NO == h->transmission_scheduled)
642     schedule_transmission (h);
643 }
644
645
646 /**
647  * Update the quota values for the given neighbour now.
648  */
649 static void
650 update_quota (struct NeighbourList *n)
651 {
652   struct GNUNET_TIME_Relative delta;
653   uint64_t allowed;
654   uint64_t remaining;
655
656   delta = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
657   allowed = delta.value * n->quota_out;
658   if (n->last_sent < allowed)
659     {
660       remaining = allowed - n->last_sent;
661       if (n->quota_out > 0)
662         remaining /= n->quota_out;
663       else
664         remaining = 0;
665       if (remaining > MAX_BANDWIDTH_CARRY)
666         remaining = MAX_BANDWIDTH_CARRY;
667       n->last_sent = 0;
668       n->last_quota_update = GNUNET_TIME_absolute_get ();
669       n->last_quota_update.value -= remaining;
670     }
671   else
672     {
673       n->last_sent -= allowed;
674       n->last_quota_update = GNUNET_TIME_absolute_get ();
675     }
676 }
677
678
679 struct SetQuotaContext
680 {
681   struct GNUNET_TRANSPORT_Handle *handle;
682
683   struct GNUNET_PeerIdentity target;
684
685   GNUNET_SCHEDULER_Task cont;
686
687   void *cont_cls;
688
689   struct GNUNET_TIME_Absolute timeout;
690
691   uint32_t quota_in;
692 };
693
694
695 static size_t
696 send_set_quota (void *cls, size_t size, void *buf)
697 {
698   struct SetQuotaContext *sqc = cls;
699   struct QuotaSetMessage *msg;
700
701   if (buf == NULL)
702     {
703       GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
704                                          sqc->cont,
705                                          sqc->cont_cls,
706                                          GNUNET_SCHEDULER_REASON_TIMEOUT);
707       GNUNET_free (sqc);
708       return 0;
709     }
710 #if DEBUG_TRANSPORT
711   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
712               "Transmitting `%s' request with respect to `%4s'.\n",
713               "SET_QUOTA", GNUNET_i2s (&sqc->target));
714 #endif
715   GNUNET_assert (size >= sizeof (struct QuotaSetMessage));
716   msg = buf;
717   msg->header.size = htons (sizeof (struct QuotaSetMessage));
718   msg->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SET_QUOTA);
719   msg->quota_in = htonl (sqc->quota_in);
720   memcpy (&msg->peer, &sqc->target, sizeof (struct GNUNET_PeerIdentity));
721   if (sqc->cont != NULL)
722     GNUNET_SCHEDULER_add_continuation (sqc->handle->sched,
723                                        sqc->cont,
724                                        sqc->cont_cls,
725                                        GNUNET_SCHEDULER_REASON_PREREQ_DONE);
726   GNUNET_free (sqc);
727   return sizeof (struct QuotaSetMessage);
728 }
729
730
731 /**
732  * Set the share of incoming bandwidth for the given
733  * peer to the specified amount.
734  *
735  * @param handle connection to transport service
736  * @param target who's bandwidth quota is being changed
737  * @param quota_in incoming bandwidth quota in bytes per ms
738  * @param quota_out outgoing bandwidth quota in bytes per ms
739  * @param timeout how long to wait until signaling failure if
740  *        we can not communicate the quota change
741  * @param cont continuation to call when done, will be called
742  *        either with reason "TIMEOUT" or with reason "PREREQ_DONE"
743  * @param cont_cls closure for continuation
744  */
745 void
746 GNUNET_TRANSPORT_set_quota (struct GNUNET_TRANSPORT_Handle *handle,
747                             const struct GNUNET_PeerIdentity *target,
748                             uint32_t quota_in,
749                             uint32_t quota_out,
750                             struct GNUNET_TIME_Relative timeout,
751                             GNUNET_SCHEDULER_Task cont, void *cont_cls)
752 {
753   struct NeighbourList *n;
754   struct SetQuotaContext *sqc;
755
756   n = find_neighbour (handle, target);
757   if (n != NULL)
758     {
759       update_quota (n);
760       if (n->quota_out < quota_out)
761         n->last_quota_update = GNUNET_TIME_absolute_get ();
762       n->quota_out = quota_out;
763     }
764   sqc = GNUNET_malloc (sizeof (struct SetQuotaContext));
765   sqc->handle = handle;
766   sqc->target = *target;
767   sqc->cont = cont;
768   sqc->cont_cls = cont_cls;
769   sqc->timeout = GNUNET_TIME_relative_to_absolute (timeout);
770   sqc->quota_in = quota_in;
771   schedule_control_transmit (handle,
772                              sizeof (struct QuotaSetMessage),
773                              GNUNET_NO, timeout, &send_set_quota, sqc);
774 }
775
776
777 /**
778  * Obtain the HELLO message for this peer.
779  *
780  * @param handle connection to transport service
781  * @param timeout how long to wait for the HELLO
782  * @param rec function to call with the HELLO, sender will be our peer
783  *            identity; message and sender will be NULL on timeout
784  *            (handshake with transport service pending/failed).
785  *             cost estimate will be 0.
786  * @param rec_cls closure for rec
787  */
788 void
789 GNUNET_TRANSPORT_get_hello (struct GNUNET_TRANSPORT_Handle *handle,
790                             GNUNET_TRANSPORT_HelloUpdateCallback rec,
791                             void *rec_cls)
792 {
793   struct HelloWaitList *hwl;
794
795   hwl = GNUNET_malloc (sizeof (struct HelloWaitList));
796   hwl->next = handle->hwl_head;
797   handle->hwl_head = hwl;
798   hwl->handle = handle;
799   hwl->rec = rec;
800   hwl->rec_cls = rec_cls;
801   if (handle->my_hello == NULL)
802     return;    
803   rec (rec_cls, (const struct GNUNET_MessageHeader *) handle->my_hello);
804 }
805
806
807
808 /**
809  * Stop receiving updates about changes to our HELLO message.
810  *
811  * @param handle connection to transport service
812  * @param rec function previously registered to be called with the HELLOs
813  * @param rec_cls closure for rec
814  */
815 void
816 GNUNET_TRANSPORT_get_hello_cancel (struct GNUNET_TRANSPORT_Handle *handle,
817                                    GNUNET_TRANSPORT_HelloUpdateCallback rec,
818                                    void *rec_cls)
819 {
820   struct HelloWaitList *pos;
821   struct HelloWaitList *prev;
822
823   prev = NULL;
824   pos = handle->hwl_head;
825   while (pos != NULL)
826     {
827       if ( (pos->rec == rec) &&
828            (pos->rec_cls == rec_cls) )
829         break;
830       prev = pos;
831       pos = pos->next;
832     }
833   GNUNET_break (pos != NULL);
834   if (pos == NULL)
835     return;
836   if (prev == NULL)
837     handle->hwl_head = pos->next;
838   else
839     prev->next = pos->next;
840   GNUNET_free (pos);
841 }
842
843
844 static size_t
845 send_hello (void *cls, size_t size, void *buf)
846 {
847   struct GNUNET_MessageHeader *hello = cls;
848   uint16_t msize;
849
850   if (buf == NULL)
851     {
852 #if DEBUG_TRANSPORT
853       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
854                   "Timeout while trying to transmit `%s' request.\n",
855                   "HELLO");
856 #endif
857       GNUNET_free (hello);
858       return 0;
859     }
860 #if DEBUG_TRANSPORT
861   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
862               "Transmitting `%s' request.\n", "HELLO");
863 #endif
864   msize = ntohs (hello->size);
865   GNUNET_assert (size >= msize);
866   memcpy (buf, hello, msize);
867   GNUNET_free (hello);
868   return msize;
869 }
870
871
872 /**
873  * Offer the transport service the HELLO of another peer.  Note that
874  * the transport service may just ignore this message if the HELLO is
875  * malformed or useless due to our local configuration.
876  *
877  * @param handle connection to transport service
878  * @param hello the hello message
879  */
880 void
881 GNUNET_TRANSPORT_offer_hello (struct GNUNET_TRANSPORT_Handle *handle,
882                               const struct GNUNET_MessageHeader *hello)
883 {
884   struct GNUNET_MessageHeader *hc;
885   uint16_t size;
886
887   if (handle->client == NULL)
888     {
889 #if DEBUG_TRANSPORT
890       GNUNET_log (GNUNET_ERROR_TYPE_INFO,
891                   "Not connected to transport service, dropping offered HELLO\n");
892       fprintf(stderr, "Not connected to transport service, dropping offered HELLO\n");
893 #endif
894       return;
895     }
896   GNUNET_break (ntohs (hello->type) == GNUNET_MESSAGE_TYPE_HELLO);
897   size = ntohs (hello->size);
898   GNUNET_break (size >= sizeof (struct GNUNET_MessageHeader));
899   hc = GNUNET_malloc (size);
900   memcpy (hc, hello, size);
901   schedule_control_transmit (handle,
902                              size,
903                              GNUNET_NO, OFFER_HELLO_TIMEOUT, &send_hello, hc);
904 }
905
906
907 /**
908  * Function we use for handling incoming messages.
909  */
910 static void demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg);
911
912
913 static size_t
914 send_start (void *cls, size_t size, void *buf)
915 {
916   struct GNUNET_MessageHeader *s = buf;
917
918   if (buf == NULL)
919     {
920 #if DEBUG_TRANSPORT
921       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
922                   "Timeout while trying to transmit `%s' request.\n",
923                   "START");
924 #endif
925       return 0;
926     }
927 #if DEBUG_TRANSPORT
928   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
929               "Transmitting `%s' request.\n", "START");
930 #endif
931   GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
932   s->size = htons (sizeof (struct GNUNET_MessageHeader));
933   s->type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_START);
934   return sizeof (struct GNUNET_MessageHeader);
935 }
936
937
938 /**
939  * We're ready to transmit the request that the transport service
940  * should connect to a new peer.  In addition to sending the
941  * request, schedule the next phase for the transmission processing
942  * that caused the connect request in the first place.
943  */
944 static size_t
945 request_connect (void *cls, size_t size, void *buf)
946 {
947   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
948   struct TryConnectMessage *tcm;
949   struct GNUNET_TRANSPORT_Handle *h;
950
951   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
952   h = th->handle;
953   if (buf == NULL)
954     {
955 #if DEBUG_TRANSPORT
956       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
957                   "Failed to transmit `%s' request for `%4s' to service.\n",
958                   "TRY_CONNECT", GNUNET_i2s (&th->target));
959 #endif
960       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
961         {
962           GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
963           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
964         }
965       if (NULL != th->notify)
966         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
967       GNUNET_free (th);
968       return 0;
969     }
970 #if DEBUG_TRANSPORT
971   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
972               "Transmitting `%s' message for `%4s' (need connection in %llu ms).\n",
973               "TRY_CONNECT", GNUNET_i2s (&th->target),
974               GNUNET_TIME_absolute_get_remaining (th->timeout).value);
975 #endif
976   GNUNET_assert (size >= sizeof (struct TryConnectMessage));
977   tcm = buf;
978   tcm->header.size = htons (sizeof (struct TryConnectMessage));
979   tcm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_TRY_CONNECT);
980   tcm->reserved = htonl (0);
981   memcpy (&tcm->peer, &th->target, sizeof (struct GNUNET_PeerIdentity));
982   th->notify_delay_task
983     = GNUNET_SCHEDULER_add_delayed (h->sched,
984                                     GNUNET_TIME_absolute_get_remaining
985                                     (th->timeout),
986                                     &peer_transmit_timeout, th);
987   insert_transmit_handle (&h->connect_wait_head, th);
988   return sizeof (struct TryConnectMessage);
989 }
990
991
992 /**
993  * Schedule a request to connect to the given
994  * neighbour (and if successful, add the specified
995  * handle to the wait list).
996  *
997  * @param th handle for a request to transmit once we
998  *        have connected
999  */
1000 static void
1001 try_connect (struct GNUNET_TRANSPORT_TransmitHandle *th)
1002 {
1003   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1004   schedule_control_transmit (th->handle,
1005                              sizeof (struct TryConnectMessage),
1006                              GNUNET_NO,
1007                              GNUNET_TIME_absolute_get_remaining (th->timeout),
1008                              &request_connect, th);
1009 }
1010
1011
1012 /**
1013  * Task for delayed attempts to reconnect to a peer.
1014  *
1015  * @param cls must be a transmit handle that determines the peer
1016  *        to which we will try to connect
1017  * @param tc scheduler information about why we were triggered (not used)
1018  */
1019 static void
1020 try_connect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1021 {
1022   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1023
1024   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1025   try_connect (th);
1026 }
1027
1028
1029 /**
1030  * Remove neighbour from our list.  Will automatically
1031  * trigger a re-connect attempt if we have messages pending
1032  * for this peer.
1033  * 
1034  * @param h our state
1035  * @param peer the peer to remove
1036  */
1037 static void
1038 remove_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1039                   const struct GNUNET_PeerIdentity *peer)
1040 {
1041   struct NeighbourList *prev;
1042   struct NeighbourList *pos;
1043   struct GNUNET_TRANSPORT_TransmitHandle *th;
1044
1045 #if DEBUG_TRANSPORT
1046   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1047               "Removing neighbour `%s' from list of connected peers.\n",
1048               GNUNET_i2s (peer));
1049 #endif
1050   prev = NULL;
1051   pos = h->neighbours;
1052   while ((pos != NULL) &&
1053          (0 != memcmp (peer, &pos->id, sizeof (struct GNUNET_PeerIdentity))))
1054     {
1055       prev = pos;
1056       pos = pos->next;
1057     }
1058   if (pos == NULL)
1059     {
1060       GNUNET_break (0);
1061       return;
1062     }
1063   if (prev == NULL)
1064     h->neighbours = pos->next;
1065   else
1066     prev->next = pos->next;
1067   if (NULL != (th = pos->transmit_handle))
1068     {
1069       pos->transmit_handle = NULL;
1070       th->neighbour = NULL;
1071       remove_from_any_list (th);
1072       if (GNUNET_TIME_absolute_get_remaining (th->timeout).value <=
1073           CONNECT_RETRY_TIMEOUT.value)
1074         {
1075           /* signal error */
1076           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1077                       _
1078                       ("Connection with `%4s' failed and timeout was in the past, giving up on message delivery.\n"),
1079                       GNUNET_i2s (peer));
1080           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1081           peer_transmit_timeout (th, NULL);
1082         }
1083       else
1084         {
1085           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1086                       _
1087                       ("Connection with `%4s' failed, will keep trying for %llu ms to deliver message\n"),
1088                       GNUNET_i2s (peer),
1089                       GNUNET_TIME_absolute_get_remaining (th->timeout).value);
1090           /* try again in a bit */
1091           GNUNET_assert (GNUNET_SCHEDULER_NO_TASK == th->notify_delay_task);
1092           th->notify_delay_task
1093             = GNUNET_SCHEDULER_add_delayed (h->sched,
1094                                             CONNECT_RETRY_TIMEOUT,
1095                                             &try_connect_task, th);
1096         }
1097     }
1098   if (h->nc_cb != NULL)
1099     h->nd_cb (h->cls, peer);
1100   GNUNET_free (pos);
1101 }
1102
1103
1104 /**
1105  * Try again to connect to transport service.
1106  */
1107 static void
1108 reconnect (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1109 {
1110   struct GNUNET_TRANSPORT_Handle *h = cls;
1111   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1112   struct NeighbourList *n;
1113
1114   /* Forget about all neighbours that we used to be connected
1115      to */
1116   while (NULL != (n = h->neighbours))
1117     remove_neighbour (h, &n->id);
1118 #if DEBUG_TRANSPORT
1119   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Connecting to transport service.\n");
1120 #endif
1121   GNUNET_assert (h->client == NULL);
1122   h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1123   h->client = GNUNET_CLIENT_connect (h->sched, "transport", h->cfg);
1124   GNUNET_assert (h->client != NULL);
1125   /* make sure we don't send "START" twice,
1126      remove existing entry from queue (if present) */
1127   pos = h->connect_ready_head;
1128   while (pos != NULL)
1129     {
1130       if (pos->notify == &send_start)
1131         {
1132           if (pos->prev == NULL)
1133             h->connect_ready_head = pos->next;
1134           else
1135             pos->prev->next = pos->next;
1136           if (pos->next != NULL)
1137             pos->next->prev = pos->prev;
1138           GNUNET_assert (pos->neighbour == NULL);
1139           if (GNUNET_SCHEDULER_NO_TASK != pos->notify_delay_task)
1140             {
1141               GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1142               pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1143             }
1144           GNUNET_free (pos);
1145           break;
1146         }
1147       pos = pos->next;
1148     }
1149   schedule_control_transmit (h,
1150                              sizeof (struct GNUNET_MessageHeader),
1151                              GNUNET_YES,
1152                              GNUNET_TIME_UNIT_FOREVER_REL, &send_start, NULL);
1153   GNUNET_CLIENT_receive (h->client,
1154                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1155 }
1156
1157
1158 /**
1159  * Function that will schedule the job that will try
1160  * to connect us again to the client.
1161  */
1162 static void
1163 schedule_reconnect (struct GNUNET_TRANSPORT_Handle *h)
1164 {
1165 #if DEBUG_TRANSPORT
1166   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1167               "Scheduling task to reconnect to transport service in %llu ms.\n",
1168               h->reconnect_delay.value);
1169 #endif
1170   GNUNET_assert (h->client == NULL);
1171   GNUNET_assert (h->reconnect_task == GNUNET_SCHEDULER_NO_TASK);
1172   h->reconnect_task
1173     = GNUNET_SCHEDULER_add_delayed (h->sched,
1174                                     h->reconnect_delay, &reconnect, h);
1175   h->reconnect_delay = GNUNET_TIME_UNIT_SECONDS;
1176 }
1177
1178
1179 /**
1180  * We are connected to the respective peer, check the
1181  * bandwidth limits and schedule the transmission.
1182  */
1183 static void schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th);
1184
1185
1186 /**
1187  * Function called by the scheduler when the timeout
1188  * for bandwidth availablility for the target
1189  * neighbour is reached.
1190  */
1191 static void
1192 transmit_ready (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
1193 {
1194   struct GNUNET_TRANSPORT_TransmitHandle *th = cls;
1195
1196   th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1197   schedule_request (th);
1198 }
1199
1200
1201 /**
1202  * Remove the given transmit handle from the wait list.  Does NOT free
1203  * it.
1204  */
1205 static void
1206 remove_from_wait_list (struct GNUNET_TRANSPORT_TransmitHandle *th)
1207 {
1208   if (th->prev == NULL)
1209     th->handle->connect_wait_head = th->next;
1210   else
1211     th->prev->next = th->next;
1212   if (th->next != NULL)
1213     th->next->prev = th->prev;
1214 }
1215
1216
1217 /**
1218  * We are connected to the respective peer, check the
1219  * bandwidth limits and schedule the transmission.
1220  */
1221 static void
1222 schedule_request (struct GNUNET_TRANSPORT_TransmitHandle *th)
1223 {
1224   struct GNUNET_TRANSPORT_Handle *h;
1225   struct GNUNET_TIME_Relative duration;
1226   struct NeighbourList *n;
1227   uint64_t available;
1228
1229   h = th->handle;
1230   n = th->neighbour;
1231   if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1232     {
1233       GNUNET_SCHEDULER_cancel (h->sched, th->notify_delay_task);
1234       th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1235     }
1236   /* check outgoing quota */
1237   duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1238   if (duration.value > MIN_QUOTA_REFRESH_TIME)
1239     {
1240       update_quota (n);
1241       duration = GNUNET_TIME_absolute_get_duration (n->last_quota_update);
1242     }
1243   available = duration.value * n->quota_out;
1244   if (available < n->last_sent + th->notify_size)
1245     {
1246       /* calculate how much bandwidth we'd still need to
1247          accumulate and based on that how long we'll have
1248          to wait... */
1249       available = n->last_sent + th->notify_size - available;
1250       duration = GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS,
1251                                                 available / n->quota_out);
1252       if (th->timeout.value <
1253           GNUNET_TIME_relative_to_absolute (duration).value)
1254         {
1255           /* signal timeout! */
1256 #if DEBUG_TRANSPORT
1257           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1258                       "Would need %llu ms before bandwidth is available for delivery to `%4s', that is too long.  Signaling timeout.\n",
1259                       duration.value, GNUNET_i2s (&th->target));
1260 #endif
1261           remove_from_wait_list (th);
1262           if (NULL != th->notify)
1263             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1264           GNUNET_free (th);
1265           return;
1266         }
1267 #if DEBUG_TRANSPORT
1268       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1269                   "Need more bandwidth, delaying delivery to `%4s' by %llu ms\n",
1270                   GNUNET_i2s (&th->target), duration.value);
1271 #endif
1272       th->notify_delay_task
1273         = GNUNET_SCHEDULER_add_delayed (h->sched,
1274                                         duration, &transmit_ready, th);
1275       return;
1276     }
1277 #if DEBUG_TRANSPORT
1278   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1279               "Bandwidth available for transmission to `%4s'\n",
1280               GNUNET_i2s (&n->id));
1281 #endif
1282   if (GNUNET_NO == n->transmit_ok)
1283     {
1284       /* we may be ready, but transport service is not;
1285          wait for SendOkMessage or timeout */
1286 #if DEBUG_TRANSPORT
1287       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1288                   "Need to wait for transport service `%s' message\n",
1289                   "SEND_OK");
1290 #endif
1291       th->notify_delay_task
1292         = GNUNET_SCHEDULER_add_delayed (h->sched,
1293                                         GNUNET_TIME_absolute_get_remaining
1294                                         (th->timeout), &peer_transmit_timeout,
1295                                         th);
1296       return;
1297     }
1298   n->transmit_ok = GNUNET_NO;
1299   remove_from_wait_list (th);
1300 #if DEBUG_TRANSPORT
1301   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1302               "Moving message for `%4s' to ready list\n",
1303               GNUNET_i2s (&n->id));
1304 #endif
1305   insert_transmit_handle (&h->connect_ready_head, th);
1306   if (GNUNET_NO == h->transmission_scheduled)
1307     schedule_transmission (h);
1308 }
1309
1310
1311 /**
1312  * Add neighbour to our list
1313  */
1314 static void
1315 add_neighbour (struct GNUNET_TRANSPORT_Handle *h,
1316                uint32_t quota_out,
1317                struct GNUNET_TIME_Relative latency,
1318                uint16_t distance,
1319                const struct GNUNET_PeerIdentity *pid)
1320 {
1321   struct NeighbourList *n;
1322   struct GNUNET_TRANSPORT_TransmitHandle *prev;
1323   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1324   struct GNUNET_TRANSPORT_TransmitHandle *next;
1325
1326   /* check for duplicates */
1327   if (NULL != find_neighbour (h, pid))
1328     {
1329       GNUNET_break (0);
1330       return;
1331     }
1332 #if DEBUG_TRANSPORT
1333   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1334               "Creating entry for new neighbour `%4s'.\n", GNUNET_i2s (pid));
1335 #endif
1336   n = GNUNET_malloc (sizeof (struct NeighbourList));
1337   n->id = *pid;
1338   n->last_quota_update = GNUNET_TIME_absolute_get ();
1339   n->quota_out = quota_out;
1340   n->next = h->neighbours;
1341   n->transmit_ok = GNUNET_YES;
1342   h->neighbours = n;
1343   if (h->nc_cb != NULL)
1344     h->nc_cb (h->cls, &n->id, latency, distance);
1345   prev = NULL;
1346   pos = h->connect_wait_head;
1347   while (pos != NULL)
1348     {
1349       next = pos->next;
1350       if (0 == memcmp (pid,
1351                        &pos->target, sizeof (struct GNUNET_PeerIdentity)))
1352         {
1353           pos->neighbour = n;
1354           GNUNET_assert (NULL == n->transmit_handle);
1355           n->transmit_handle = pos;
1356           if (prev == NULL)
1357             h->connect_wait_head = next;
1358           else
1359             prev->next = next;
1360           if (GNUNET_YES == n->received_ack)
1361             {
1362 #if DEBUG_TRANSPORT
1363               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1364                           "Found pending request for `%4s' will trigger it now.\n",
1365                           GNUNET_i2s (&pos->target));
1366 #endif
1367               if (pos->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1368                 {
1369                   GNUNET_SCHEDULER_cancel (h->sched, pos->notify_delay_task);
1370                   pos->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1371                 }
1372               schedule_request (pos);
1373             }
1374           else
1375             {
1376 #if DEBUG_TRANSPORT
1377               GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1378                           "Found pending request for `%4s' but still need `%s' before proceeding.\n",
1379                           GNUNET_i2s (&pos->target), "ACK");
1380 #endif
1381             }
1382           break;
1383         }
1384       prev = pos;
1385       pos = next;
1386     }
1387 }
1388
1389
1390 /**
1391  * Connect to the transport service.  Note that the connection may
1392  * complete (or fail) asynchronously.
1393  *
1394
1395  * @param sched scheduler to use
1396  * @param cfg configuration to use
1397  * @param cls closure for the callbacks
1398  * @param rec receive function to call
1399  * @param nc function to call on connect events
1400  * @param nd function to call on disconnect events
1401  */
1402 struct GNUNET_TRANSPORT_Handle *
1403 GNUNET_TRANSPORT_connect (struct GNUNET_SCHEDULER_Handle *sched,
1404                           const struct GNUNET_CONFIGURATION_Handle *cfg,
1405                           void *cls,
1406                           GNUNET_TRANSPORT_ReceiveCallback rec,
1407                           GNUNET_TRANSPORT_NotifyConnect nc,
1408                           GNUNET_TRANSPORT_NotifyDisconnect nd)
1409 {
1410   struct GNUNET_TRANSPORT_Handle *ret;
1411
1412   GNUNET_ARM_start_services (cfg, sched, "peerinfo", "transport", NULL);
1413   ret = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_Handle));
1414   ret->sched = sched;
1415   ret->cfg = cfg;
1416   ret->cls = cls;
1417   ret->rec = rec;
1418   ret->nc_cb = nc;
1419   ret->nd_cb = nd;
1420   ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
1421   schedule_reconnect (ret);
1422   return ret;
1423 }
1424
1425
1426 /**
1427  * Disconnect from the transport service.
1428  */
1429 void
1430 GNUNET_TRANSPORT_disconnect (struct GNUNET_TRANSPORT_Handle *handle)
1431 {
1432   struct GNUNET_TRANSPORT_TransmitHandle *th;
1433   struct NeighbourList *n;
1434   struct HelloWaitList *hwl;
1435   struct GNUNET_CLIENT_Connection *client;
1436
1437 #if DEBUG_TRANSPORT
1438   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Transport disconnect called!\n");
1439 #endif
1440   while (NULL != (th = handle->connect_ready_head))
1441     {
1442       handle->connect_ready_head = th->next;
1443       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1444         {
1445           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1446           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1447         }
1448       if (NULL != th->notify)
1449         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1450       GNUNET_free (th);
1451     }
1452   while (NULL != (th = handle->connect_wait_head))
1453     {
1454       handle->connect_wait_head = th->next;
1455       if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1456         {
1457           GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1458           th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1459         }
1460       if (NULL != th->notify)
1461         GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));
1462       GNUNET_free (th);
1463     }
1464   while (NULL != (n = handle->neighbours))
1465     {
1466       handle->neighbours = n->next;
1467       if (NULL != (th = n->transmit_handle))
1468         {
1469           if (th->notify_delay_task != GNUNET_SCHEDULER_NO_TASK)
1470             {
1471               GNUNET_SCHEDULER_cancel (handle->sched, th->notify_delay_task);
1472               th->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1473             }
1474           if (NULL != th->notify)
1475             GNUNET_assert (0 == th->notify (th->notify_cls, 0, NULL));        
1476           GNUNET_free (th);
1477         }
1478       GNUNET_free (n);
1479     }
1480   while (NULL != (hwl = handle->hwl_head))
1481     {
1482       handle->hwl_head = hwl->next;
1483       GNUNET_SCHEDULER_cancel (handle->sched, hwl->task);
1484       GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
1485                   _
1486                   ("Disconnect while notification for `%s' still registered.\n"),
1487                   "HELLO");
1488       if (hwl->rec != NULL)
1489         hwl->rec (hwl->rec_cls, NULL);
1490       GNUNET_free (hwl);
1491     }
1492   if (handle->reconnect_task != GNUNET_SCHEDULER_NO_TASK)
1493     {
1494       GNUNET_SCHEDULER_cancel (handle->sched, handle->reconnect_task);
1495       handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
1496     }
1497   GNUNET_free_non_null (handle->my_hello);
1498   handle->my_hello = NULL;
1499   GNUNET_ARM_stop_services (handle->cfg, handle->sched, "transport",
1500                             "peerinfo", NULL);
1501   if (NULL != handle->network_handle)
1502     {
1503       GNUNET_CLIENT_notify_transmit_ready_cancel (handle->network_handle);
1504       handle->network_handle = NULL;
1505     }
1506   if (NULL != (client = handle->client))
1507     {
1508 #if DEBUG_TRANSPORT
1509       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1510                   "Disconnecting from transport service for good.\n");
1511 #endif
1512       handle->client = NULL;
1513       GNUNET_CLIENT_disconnect (client);
1514     }
1515   GNUNET_free (handle);
1516 }
1517
1518
1519 /**
1520  * Type of a function to call when we receive a message
1521  * from the service.
1522  *
1523  * @param cls closure
1524  * @param msg message received, NULL on timeout or fatal error
1525  */
1526 static void
1527 demultiplexer (void *cls, const struct GNUNET_MessageHeader *msg)
1528 {
1529   struct GNUNET_TRANSPORT_Handle *h = cls;
1530   const struct DisconnectInfoMessage *dim;
1531   const struct ConnectInfoMessage *cim;
1532   const struct InboundMessage *im;
1533   const struct GNUNET_MessageHeader *imm;
1534   const struct SendOkMessage *okm;
1535   struct HelloWaitList *hwl;
1536   struct HelloWaitList *next_hwl;
1537   struct NeighbourList *n;
1538   struct GNUNET_PeerIdentity me;
1539   struct GNUNET_TRANSPORT_TransmitHandle *th;
1540   uint16_t size;
1541
1542   if ((msg == NULL) || (h->client == NULL))
1543     {
1544       if (h->client != NULL)
1545         {
1546 #if DEBUG_TRANSPORT
1547           GNUNET_log (GNUNET_ERROR_TYPE_INFO,
1548                       "Error receiving from transport service, disconnecting temporarily.\n");
1549 #endif
1550           if (h->network_handle != NULL)
1551             {
1552               GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1553               h->network_handle = NULL;
1554               h->transmission_scheduled = GNUNET_NO;
1555               th = h->connect_ready_head;
1556               /* add timeout again, we cancelled the transmit_ready task! */
1557               GNUNET_assert (th->notify_delay_task ==
1558                              GNUNET_SCHEDULER_NO_TASK);
1559               th->notify_delay_task =
1560                 GNUNET_SCHEDULER_add_delayed (h->sched,
1561                                               GNUNET_TIME_absolute_get_remaining
1562                                               (th->timeout),
1563                                               &peer_transmit_timeout, th);
1564             }
1565           GNUNET_CLIENT_disconnect (h->client);
1566           h->client = NULL;
1567           schedule_reconnect (h);
1568         }
1569       else
1570         {
1571           /* shutdown initiated from 'GNUNET_TRANSPORT_disconnect',
1572              finish clean up work! */
1573           GNUNET_free (h);
1574         }
1575       return;
1576     }
1577   GNUNET_CLIENT_receive (h->client,
1578                          &demultiplexer, h, GNUNET_TIME_UNIT_FOREVER_REL);
1579   size = ntohs (msg->size);
1580   switch (ntohs (msg->type))
1581     {
1582     case GNUNET_MESSAGE_TYPE_HELLO:
1583       if (GNUNET_OK !=
1584           GNUNET_HELLO_get_id ((const struct GNUNET_HELLO_Message *) msg,
1585                                &me))
1586         {
1587           GNUNET_break (0);
1588           break;
1589         }
1590 #if DEBUG_TRANSPORT
1591       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1592                   "Receiving (my own) `%s' message, I am `%4s'.\n",
1593                   "HELLO", GNUNET_i2s (&me));
1594 #endif
1595       GNUNET_free_non_null (h->my_hello);
1596       h->my_hello = NULL;
1597       if (size < sizeof (struct GNUNET_MessageHeader))
1598         {
1599           GNUNET_break (0);
1600           break;
1601         }
1602       h->my_hello = GNUNET_malloc (size);
1603       memcpy (h->my_hello, msg, size);
1604       hwl = h->hwl_head;
1605       while (NULL != hwl)
1606         {
1607           next_hwl = hwl->next;
1608           hwl->rec (hwl->rec_cls,
1609                     (const struct GNUNET_MessageHeader *) h->my_hello);
1610           hwl = next_hwl;
1611         }
1612       break;
1613     case GNUNET_MESSAGE_TYPE_TRANSPORT_CONNECT:
1614       if (size != sizeof (struct ConnectInfoMessage))
1615         {
1616           GNUNET_break (0);
1617           break;
1618         }
1619       cim = (const struct ConnectInfoMessage *) msg;
1620 #if DEBUG_TRANSPORT
1621       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1622                   "Receiving `%s' message for `%4s'.\n",
1623                   "CONNECT", GNUNET_i2s (&cim->id));
1624 #endif
1625       add_neighbour (h,
1626                      ntohl (cim->quota_out),
1627                      GNUNET_TIME_relative_ntoh (cim->latency), ntohs(cim->distance), &cim->id);
1628       break;
1629     case GNUNET_MESSAGE_TYPE_TRANSPORT_DISCONNECT:
1630       if (size != sizeof (struct DisconnectInfoMessage))
1631         {
1632           GNUNET_break (0);
1633           break;
1634         }
1635       dim = (const struct DisconnectInfoMessage *) msg;
1636 #if DEBUG_TRANSPORT
1637       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1638                   "Receiving `%s' message for `%4s'.\n",
1639                   "DISCONNECT", GNUNET_i2s (&dim->peer));
1640 #endif
1641       remove_neighbour (h, &dim->peer);
1642       break;
1643     case GNUNET_MESSAGE_TYPE_TRANSPORT_SEND_OK:
1644       if (size != sizeof (struct SendOkMessage))
1645         {
1646           GNUNET_break (0);
1647           break;
1648         }
1649       okm = (const struct SendOkMessage *) msg;
1650 #if DEBUG_TRANSPORT
1651       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1652                   "Receiving `%s' message, transmission %s.\n", "SEND_OK",
1653                   ntohl (okm->success) == GNUNET_OK ? "succeeded" : "failed");
1654 #endif
1655       n = find_neighbour (h, &okm->peer);
1656       GNUNET_assert (n != NULL);
1657       n->transmit_ok = GNUNET_YES;
1658       if (n->transmit_handle != NULL)
1659         {
1660 #if DEBUG_TRANSPORT
1661           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1662                       "Processing pending message for `%4s'\n",
1663                       GNUNET_i2s (&n->id));
1664 #endif
1665           GNUNET_SCHEDULER_cancel (h->sched,
1666                                    n->transmit_handle->notify_delay_task);
1667           n->transmit_handle->notify_delay_task = GNUNET_SCHEDULER_NO_TASK;
1668           GNUNET_assert (GNUNET_YES == n->received_ack);
1669           schedule_request (n->transmit_handle);
1670         }
1671       break;
1672     case GNUNET_MESSAGE_TYPE_TRANSPORT_RECV:
1673 #if DEBUG_TRANSPORT
1674       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1675                   "Receiving `%s' message.\n", "RECV");
1676 #endif
1677       if (size <
1678           sizeof (struct InboundMessage) +
1679           sizeof (struct GNUNET_MessageHeader))
1680         {
1681           GNUNET_break (0);
1682           break;
1683         }
1684       im = (const struct InboundMessage *) msg;
1685       imm = (const struct GNUNET_MessageHeader *) &im[1];
1686       if (ntohs (imm->size) + sizeof (struct InboundMessage) != size)
1687         {
1688           GNUNET_break (0);
1689           break;
1690         }
1691       switch (ntohs (imm->type))
1692         {
1693         case GNUNET_MESSAGE_TYPE_TRANSPORT_ACK:
1694 #if DEBUG_TRANSPORT
1695           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1696                       "Receiving `%s' message from `%4s'.\n",
1697                       "ACK", GNUNET_i2s (&im->peer));
1698 #endif
1699           n = find_neighbour (h, &im->peer);
1700           if (n == NULL)
1701             {
1702               GNUNET_break (0);
1703               break;
1704             }
1705           if (n->received_ack == GNUNET_NO)
1706             {
1707               n->received_ack = GNUNET_YES;
1708               if (NULL != n->transmit_handle)
1709                 {
1710 #if DEBUG_TRANSPORT
1711                   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1712                               "Peer connected, scheduling delayed message for delivery now.\n");
1713 #endif
1714                   schedule_request (n->transmit_handle);
1715                 }
1716             }
1717           break;
1718         default:
1719 #if DEBUG_TRANSPORT
1720           GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1721                       "Received message of type %u from `%4s'.\n",
1722                       ntohs (imm->type), GNUNET_i2s (&im->peer));
1723 #endif
1724           if (h->rec != NULL)
1725             h->rec (h->cls, &im->peer, imm,
1726                     GNUNET_TIME_relative_ntoh (im->latency), ntohs(im->distance));
1727           break;
1728         }
1729       break;
1730     default:
1731       GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
1732                   _
1733                   ("Received unexpected message of type %u in %s:%u\n"),
1734                   ntohs (msg->type), __FILE__, __LINE__);
1735       GNUNET_break (0);
1736       break;
1737     }
1738 }
1739
1740
1741 struct ClientTransmitWrapper
1742 {
1743   GNUNET_CONNECTION_TransmitReadyNotify notify;
1744   void *notify_cls;
1745   struct GNUNET_TRANSPORT_TransmitHandle *th;
1746 };
1747
1748
1749 /**
1750  * Transmit message of a client destined for another
1751  * peer to the service.
1752  */
1753 static size_t
1754 client_notify_wrapper (void *cls, size_t size, void *buf)
1755 {
1756   struct ClientTransmitWrapper *ctw = cls;
1757   struct OutboundMessage *obm;
1758   struct GNUNET_MessageHeader *hdr;
1759   size_t ret;
1760
1761   if (size == 0)
1762     {
1763 #if DEBUG_TRANSPORT
1764       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1765                   "Transmission request could not be satisfied.\n");
1766 #endif
1767       if (NULL != ctw->notify)
1768         GNUNET_assert (0 == ctw->notify (ctw->notify_cls, 0, NULL));
1769       GNUNET_free (ctw);
1770       return 0;
1771     }
1772   GNUNET_assert (size >= sizeof (struct OutboundMessage));
1773   obm = buf;
1774   if (ctw->notify != NULL)
1775     ret = ctw->notify (ctw->notify_cls,
1776                        size - sizeof (struct OutboundMessage),
1777                        (void *) &obm[1]);
1778   else
1779     ret = 0;
1780   if (ret == 0)
1781     {
1782       /* Need to reset flag, no SEND means no SEND_OK! */
1783       ctw->th->neighbour->transmit_ok = GNUNET_YES;
1784       GNUNET_free (ctw);
1785       return 0;
1786     }
1787   GNUNET_assert (ret >= sizeof (struct GNUNET_MessageHeader));
1788   hdr = (struct GNUNET_MessageHeader *) &obm[1];
1789   GNUNET_assert (ntohs (hdr->size) == ret);
1790   GNUNET_assert (ret + sizeof (struct OutboundMessage) <
1791                  GNUNET_SERVER_MAX_MESSAGE_SIZE);
1792 #if DEBUG_TRANSPORT
1793   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1794               "Transmitting `%s' message with data for `%4s'\n",
1795               "SEND", GNUNET_i2s (&ctw->th->target));
1796 #endif
1797   ret += sizeof (struct OutboundMessage);
1798   obm->header.type = htons (GNUNET_MESSAGE_TYPE_TRANSPORT_SEND);
1799   obm->header.size = htons (ret);
1800   obm->priority = htonl (ctw->th->priority);
1801   obm->peer = ctw->th->target;
1802   GNUNET_free (ctw);
1803   return ret;
1804 }
1805
1806
1807
1808 /**
1809  * Check if we could queue a message of the given size for
1810  * transmission.  The transport service will take both its
1811  * internal buffers and bandwidth limits imposed by the
1812  * other peer into consideration when answering this query.
1813  *
1814  * @param handle connection to transport service
1815  * @param target who should receive the message
1816  * @param size how big is the message we want to transmit?
1817  * @param priority how important is the message?
1818  * @param timeout after how long should we give up (and call
1819  *        notify with buf NULL and size 0)?
1820  * @param notify function to call when we are ready to
1821  *        send such a message
1822  * @param notify_cls closure for notify
1823  * @return NULL if someone else is already waiting to be notified
1824  *         non-NULL if the notify callback was queued (can be used to cancel
1825  *         using GNUNET_TRANSPORT_notify_transmit_ready_cancel)
1826  */
1827 struct GNUNET_TRANSPORT_TransmitHandle *
1828 GNUNET_TRANSPORT_notify_transmit_ready (struct GNUNET_TRANSPORT_Handle
1829                                         *handle,
1830                                         const struct GNUNET_PeerIdentity
1831                                         *target, size_t size,
1832                                         unsigned int priority,
1833                                         struct GNUNET_TIME_Relative timeout,
1834                                         GNUNET_CONNECTION_TransmitReadyNotify
1835                                         notify, void *notify_cls)
1836 {
1837   struct GNUNET_TRANSPORT_TransmitHandle *pos;
1838   struct GNUNET_TRANSPORT_TransmitHandle *th;
1839   struct NeighbourList *n;
1840   struct ClientTransmitWrapper *ctw;
1841
1842   if (size + sizeof (struct OutboundMessage) >=
1843       GNUNET_SERVER_MAX_MESSAGE_SIZE)
1844     {
1845       GNUNET_break (0);
1846       return NULL;
1847     }
1848 #if DEBUG_TRANSPORT
1849   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1850               "Asking transport service for transmission of %u bytes to peer `%4s'.\n",
1851               size, GNUNET_i2s (target));
1852 #endif
1853   n = find_neighbour (handle, target);
1854   if ((n != NULL) && (n->transmit_handle != NULL))
1855     return NULL;                /* already have a request pending for this peer! */
1856   ctw = GNUNET_malloc (sizeof (struct ClientTransmitWrapper));
1857   th = GNUNET_malloc (sizeof (struct GNUNET_TRANSPORT_TransmitHandle));
1858   ctw->notify = notify;
1859   ctw->notify_cls = notify_cls;
1860   ctw->th = th;
1861   th->handle = handle;
1862   th->neighbour = n;
1863   th->target = *target;
1864   th->notify = &client_notify_wrapper;
1865   th->notify_cls = ctw;
1866   th->timeout = GNUNET_TIME_relative_to_absolute (timeout);
1867   th->notify_size = size + sizeof (struct OutboundMessage);
1868   th->priority = priority;
1869   if (NULL == n)
1870     {
1871       pos = handle->connect_wait_head;
1872       while (pos != NULL)
1873         {
1874           GNUNET_assert (0 != memcmp (target,
1875                                       &pos->target,
1876                                       sizeof (struct GNUNET_PeerIdentity)));
1877           pos = pos->next;
1878         }
1879 #if DEBUG_TRANSPORT
1880       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1881                   "Will now try to connect to `%4s'.\n", GNUNET_i2s (target));
1882 #endif
1883       try_connect (th);
1884       return th;
1885     }
1886
1887 #if DEBUG_TRANSPORT
1888   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1889               "Transmission request queued for transmission to transport service.\n");
1890 #endif
1891   GNUNET_assert (NULL == n->transmit_handle);
1892   n->transmit_handle = th;
1893   if (GNUNET_YES != n->received_ack)
1894     {
1895 #if DEBUG_TRANSPORT
1896       GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1897                   "Connection to `%4s' is not yet confirmed connected, scheduling timeout (%llu ms) only.\n",
1898                   GNUNET_i2s (target), timeout.value);
1899 #endif
1900       th->notify_delay_task
1901         = GNUNET_SCHEDULER_add_delayed (handle->sched,
1902                                         timeout, &peer_transmit_timeout, th);
1903       return th;
1904     }
1905
1906 #if DEBUG_TRANSPORT
1907   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1908               "Peer `%4s' is ready to receive, scheduling message for delivery now.\n",
1909               GNUNET_i2s (target));
1910 #endif
1911   th->notify_delay_task
1912     = GNUNET_SCHEDULER_add_now (handle->sched, &transmit_ready, th);
1913   return th;
1914 }
1915
1916
1917 /**
1918  * Cancel the specified transmission-ready notification.
1919  */
1920 void
1921 GNUNET_TRANSPORT_notify_transmit_ready_cancel (struct
1922                                                GNUNET_TRANSPORT_TransmitHandle
1923                                                *th)
1924 {
1925   struct GNUNET_TRANSPORT_Handle *h;
1926
1927 #if DEBUG_TRANSPORT
1928   GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
1929               "Transmission request of %u bytes to `%4s' was cancelled.\n",
1930               th->notify_size - sizeof (struct OutboundMessage),
1931               GNUNET_i2s (&th->target));
1932 #endif
1933   GNUNET_assert (th->notify == &client_notify_wrapper);
1934   remove_from_any_list (th);
1935   h = th->handle;
1936   if ((h->connect_ready_head == NULL) && (h->network_handle != NULL))
1937     {
1938       GNUNET_CLIENT_notify_transmit_ready_cancel (h->network_handle);
1939       h->network_handle = NULL;
1940       h->transmission_scheduled = GNUNET_NO;
1941     }
1942   GNUNET_free (th->notify_cls);
1943   GNUNET_assert (th->notify_delay_task == GNUNET_SCHEDULER_NO_TASK);
1944   GNUNET_free (th);
1945 }
1946
1947
1948 /* end of transport_api.c */