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21 * @file ats/ats_api_scheduling.c
22 * @brief automatic transport selection and outbound bandwidth determination
23 * @author Christian Grothoff
24 * @author Matthias Wachs
27 * - we could avoid a linear scan over the
28 * active addresses in some cases, so if
29 * there is need, we can still optimize here
30 * - we might want to split off the logic to
31 * determine LAN vs. WAN, as it has nothing
32 * to do with accessing the ATS service.
35 #include "gnunet_ats_service.h"
39 * How frequently do we scan the interfaces for changes to the addresses?
41 #define INTERFACE_PROCESSING_INTERVAL GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MINUTES, 2)
43 #define LOG(kind,...) GNUNET_log_from(kind, "ats-scheduling-api", __VA_ARGS__)
46 * Session ID we use if there is no session / slot.
52 * Information we track per address, incoming or outgoing. It also
53 * doesn't matter if we have a session, any address that ATS is
54 * allowed to suggest right now should be tracked.
56 struct GNUNET_ATS_AddressRecord
60 * Scheduling handle this address record belongs to.
62 struct GNUNET_ATS_SchedulingHandle *sh;
67 struct GNUNET_HELLO_Address *address;
70 * Session handle. NULL if we have an address but no
71 * active session for this address.
73 struct GNUNET_ATS_Session *session;
76 * Performance data about the address.
78 struct GNUNET_ATS_PropertiesNBO properties;
81 * Which slot (index) in the session array does
82 * this record correspond to?
83 * FIXME: a linear search on this is really crappy!
84 * Maybe switch to a 64-bit global counter and be
85 * done with it? Or does that then cause too much
86 * trouble on the ATS-service side?
91 * We're about to destroy this address record, just ATS does
92 * not know this yet. Once ATS confirms its destruction,
100 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
102 struct GNUNET_ATS_SchedulingHandle
108 const struct GNUNET_CONFIGURATION_Handle *cfg;
111 * Callback to invoke on suggestions.
113 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
116 * Closure for @e suggest_cb.
118 void *suggest_cb_cls;
121 * Message queue for sending requests to the ATS service.
123 struct GNUNET_MQ_Handle *mq;
126 * Array of session objects (we need to translate them to numbers and back
127 * for the protocol; the offset in the array is the session number on the
128 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
129 * Unused entries are also NULL.
131 struct GNUNET_ATS_AddressRecord **session_array;
134 * Task to trigger reconnect.
136 struct GNUNET_SCHEDULER_Task *task;
139 * Reconnect backoff delay.
141 struct GNUNET_TIME_Relative backoff;
144 * Size of the @e session_array.
146 unsigned int session_array_size;
152 * Re-establish the connection to the ATS service.
154 * @param sh handle to use to re-connect.
157 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
161 * Re-establish the connection to the ATS service.
163 * @param cls handle to use to re-connect.
166 reconnect_task (void *cls)
168 struct GNUNET_ATS_SchedulingHandle *sh = cls;
176 * Disconnect from ATS and then reconnect.
178 * @param sh our handle
181 force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
185 GNUNET_MQ_destroy (sh->mq);
188 sh->suggest_cb (sh->suggest_cb_cls,
190 GNUNET_BANDWIDTH_ZERO,
191 GNUNET_BANDWIDTH_ZERO);
192 sh->backoff = GNUNET_TIME_STD_BACKOFF (sh->backoff);
193 sh->task = GNUNET_SCHEDULER_add_delayed (sh->backoff,
200 * Find the session object corresponding to the given session ID.
202 * @param sh our handle
203 * @param session_id current session ID
204 * @param peer peer the session belongs to
205 * @return the session object (or NULL)
207 static struct GNUNET_ATS_AddressRecord *
208 find_session (struct GNUNET_ATS_SchedulingHandle *sh,
210 const struct GNUNET_PeerIdentity *peer)
212 struct GNUNET_ATS_AddressRecord *ar;
214 if (session_id >= sh->session_array_size)
221 ar = sh->session_array[session_id];
227 if (NULL == ar->address)
229 /* address was destroyed in the meantime, this can happen
230 as we communicate asynchronously with the ATS service. */
233 if (0 != memcmp (peer,
235 sizeof (struct GNUNET_PeerIdentity)))
245 * Get an available session ID.
247 * @param sh our handle
248 * @return an unused slot, but never NOT_FOUND (0)
251 find_empty_session_slot (struct GNUNET_ATS_SchedulingHandle *sh)
257 while ( ( (NOT_FOUND == off) ||
258 (NULL != sh->session_array[off % sh->session_array_size]) ) &&
259 (i < sh->session_array_size) )
264 if ( (NOT_FOUND != off % sh->session_array_size) &&
265 (NULL == sh->session_array[off % sh->session_array_size]) )
267 i = sh->session_array_size;
268 GNUNET_array_grow (sh->session_array,
269 sh->session_array_size,
270 sh->session_array_size * 2);
276 * Get the ID for the given session object.
278 * @param sh our handle
279 * @param session session object
280 * @param address the address we are looking for
281 * @return the session id or NOT_FOUND for error
284 find_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
285 struct GNUNET_ATS_Session *session,
286 const struct GNUNET_HELLO_Address *address)
295 for (i = 1; i < sh->session_array_size; i++)
296 if ( (NULL != sh->session_array[i]) &&
297 (GNUNET_NO == sh->session_array[i]->in_destroy) &&
298 ( (session == sh->session_array[i]->session) ||
299 (NULL == sh->session_array[i]->session) ) &&
300 (0 == memcmp (&address->peer,
301 &sh->session_array[i]->address->peer,
302 sizeof (struct GNUNET_PeerIdentity))) &&
303 (0 == GNUNET_HELLO_address_cmp (address,
304 sh->session_array[i]->address)) )
311 * Release the session slot from the session table (ATS service is
312 * also done using it).
314 * @param sh our handle
315 * @param session_id identifies session that is no longer valid
318 release_session (struct GNUNET_ATS_SchedulingHandle *sh,
321 struct GNUNET_ATS_AddressRecord *ar;
323 if (NOT_FOUND == session_id)
325 if (session_id >= sh->session_array_size)
328 force_reconnect (sh);
331 /* this slot should have been removed from remove_session before */
332 ar = sh->session_array[session_id];
333 if (NULL != ar->session)
336 force_reconnect (sh);
339 GNUNET_HELLO_address_free (ar->address);
341 sh->session_array[session_id] = NULL;
346 * Type of a function to call when we receive a session release
347 * message from the service.
349 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
350 * @param srm message received
353 handle_ats_session_release (void *cls,
354 const struct GNUNET_ATS_SessionReleaseMessage *srm)
356 struct GNUNET_ATS_SchedulingHandle *sh = cls;
358 /* Note: peer field in srm not necessary right now,
359 but might be good to have in the future */
361 ntohl (srm->session_id));
366 * Type of a function to call when we receive a address suggestion
367 * message from the service.
369 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
370 * @param m message received
373 handle_ats_address_suggestion (void *cls,
374 const struct AddressSuggestionMessage *m)
376 struct GNUNET_ATS_SchedulingHandle *sh = cls;
377 struct GNUNET_ATS_AddressRecord *ar;
380 session_id = ntohl (m->session_id);
384 force_reconnect (sh);
387 ar = find_session (sh,
393 force_reconnect (sh);
396 if (NULL == sh->suggest_cb)
398 if (GNUNET_YES == ar->in_destroy)
400 /* ignore suggestion, as this address is dying, unless BW is 0,
401 in that case signal 'disconnect' via BW 0 */
402 if ( (0 == ntohl (m->bandwidth_out.value__)) &&
403 (0 == ntohl (m->bandwidth_in.value__)) )
405 LOG (GNUNET_ERROR_TYPE_DEBUG,
406 "ATS suggests disconnect from peer `%s' with BW %u/%u\n",
407 GNUNET_i2s (&ar->address->peer),
408 (unsigned int) ntohl (m->bandwidth_out.value__),
409 (unsigned int) ntohl (m->bandwidth_in.value__));
410 sh->suggest_cb (sh->suggest_cb_cls,
419 if ( (NULL == ar->session) &&
420 (GNUNET_HELLO_address_check_option (ar->address,
421 GNUNET_HELLO_ADDRESS_INFO_INBOUND)) )
426 sh->backoff = GNUNET_TIME_UNIT_ZERO;
427 LOG (GNUNET_ERROR_TYPE_DEBUG,
428 "ATS suggests address slot %u for peer `%s' using plugin %s\n",
430 GNUNET_i2s (&ar->address->peer),
431 ar->address->transport_name);
432 sh->suggest_cb (sh->suggest_cb_cls,
442 * We encountered an error handling the MQ to the
443 * ATS service. Reconnect.
445 * @param cls the `struct GNUNET_ATS_SchedulingHandle`
446 * @param error details about the error
449 error_handler (void *cls,
450 enum GNUNET_MQ_Error error)
452 struct GNUNET_ATS_SchedulingHandle *sh = cls;
454 LOG (GNUNET_ERROR_TYPE_DEBUG,
455 "ATS connection died (code %d), reconnecting\n",
457 force_reconnect (sh);
462 * Generate and transmit the `struct AddressAddMessage` for the given
465 * @param sh the scheduling handle to use for transmission
466 * @param ar the address to inform the ATS service about
469 send_add_address_message (struct GNUNET_ATS_SchedulingHandle *sh,
470 const struct GNUNET_ATS_AddressRecord *ar)
472 struct GNUNET_MQ_Envelope *ev;
473 struct AddressAddMessage *m;
479 return; /* disconnected, skip for now */
480 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != ar->properties.scope);
481 namelen = strlen (ar->address->transport_name) + 1;
482 msize = ar->address->address_length + namelen;
483 ev = GNUNET_MQ_msg_extra (m, msize, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_ADD);
484 m->peer = ar->address->peer;
485 m->address_length = htons (ar->address->address_length);
486 m->address_local_info = htonl ((uint32_t) ar->address->local_info);
487 m->plugin_name_length = htons (namelen);
488 m->session_id = htonl (ar->slot);
489 m->properties = ar->properties;
491 LOG (GNUNET_ERROR_TYPE_DEBUG,
492 "Adding address for peer `%s', plugin `%s', session %p slot %u\n",
493 GNUNET_i2s (&ar->address->peer),
494 ar->address->transport_name,
499 ar->address->address,
500 ar->address->address_length);
501 if (NULL != ar->address->transport_name)
502 memcpy (&pm[ar->address->address_length],
503 ar->address->transport_name,
505 GNUNET_MQ_send (sh->mq, ev);
510 * Re-establish the connection to the ATS service.
512 * @param sh handle to use to re-connect.
515 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
517 GNUNET_MQ_hd_fixed_size (ats_session_release,
518 GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE,
519 struct GNUNET_ATS_SessionReleaseMessage);
520 GNUNET_MQ_hd_fixed_size (ats_address_suggestion,
521 GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION,
522 struct AddressSuggestionMessage);
523 struct GNUNET_MQ_MessageHandler handlers[] = {
524 make_ats_session_release_handler (sh),
525 make_ats_address_suggestion_handler (sh),
526 GNUNET_MQ_handler_end ()
528 struct GNUNET_MQ_Envelope *ev;
529 struct ClientStartMessage *init;
531 struct GNUNET_ATS_AddressRecord *ar;
532 struct GNUNET_CLIENT_Connection *client;
534 GNUNET_assert (NULL == sh->mq);
535 client = GNUNET_CLIENT_connect ("ats",
540 force_reconnect (sh);
543 sh->mq = GNUNET_MQ_queue_for_connection_client (client,
547 ev = GNUNET_MQ_msg (init,
548 GNUNET_MESSAGE_TYPE_ATS_START);
549 init->start_flag = htonl (START_FLAG_SCHEDULING);
550 GNUNET_MQ_send (sh->mq, ev);
553 for (i=0;i<sh->session_array_size;i++)
555 ar = sh->session_array[i];
558 send_add_address_message (sh, ar);
566 * Initialize the ATS subsystem.
568 * @param cfg configuration to use
569 * @param suggest_cb notification to call whenever the suggestation changed
570 * @param suggest_cb_cls closure for @a suggest_cb
571 * @return ats context
573 struct GNUNET_ATS_SchedulingHandle *
574 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
575 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
576 void *suggest_cb_cls)
578 struct GNUNET_ATS_SchedulingHandle *sh;
580 sh = GNUNET_new (struct GNUNET_ATS_SchedulingHandle);
582 sh->suggest_cb = suggest_cb;
583 sh->suggest_cb_cls = suggest_cb_cls;
584 GNUNET_array_grow (sh->session_array,
585 sh->session_array_size,
593 * Client is done with ATS scheduling, release resources.
595 * @param sh handle to release
598 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
600 struct GNUNET_ATS_AddressRecord *ar;
605 GNUNET_MQ_destroy (sh->mq);
608 if (NULL != sh->task)
610 GNUNET_SCHEDULER_cancel (sh->task);
613 for (i=0;i<sh->session_array_size;i++)
615 if (NULL != (ar = sh->session_array[i]))
617 GNUNET_HELLO_address_free (ar->address);
619 sh->session_array[i] = NULL;
622 GNUNET_array_grow (sh->session_array,
623 sh->session_array_size,
630 * We have a new address ATS should know. Addresses have to be added
631 * with this function before they can be: updated, set in use and
635 * @param address the address
636 * @param session session handle, can be NULL
637 * @param prop performance data for the address
638 * @return handle to the address representation inside ATS, NULL
639 * on error (i.e. ATS knows this exact address already)
641 struct GNUNET_ATS_AddressRecord *
642 GNUNET_ATS_address_add (struct GNUNET_ATS_SchedulingHandle *sh,
643 const struct GNUNET_HELLO_Address *address,
644 struct GNUNET_ATS_Session *session,
645 const struct GNUNET_ATS_Properties *prop)
647 struct GNUNET_ATS_AddressRecord *ar;
654 /* we need a valid address */
658 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
659 namelen = strlen (address->transport_name) + 1;
660 msize = address->address_length + namelen;
661 if ((msize + sizeof (struct AddressUpdateMessage) >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
662 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
663 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
665 /* address too large for us, this should not happen */
675 /* Already existing, nothing todo, but this should not happen */
679 s = find_empty_session_slot (sh);
680 ar = GNUNET_new (struct GNUNET_ATS_AddressRecord);
683 ar->session = session;
684 ar->address = GNUNET_HELLO_address_copy (address);
685 GNUNET_ATS_properties_hton (&ar->properties,
687 sh->session_array[s] = ar;
688 send_add_address_message (sh, ar);
694 * An address was used to initiate a session.
696 * @param ar address record to update information for
697 * @param session session handle
700 GNUNET_ATS_address_add_session (struct GNUNET_ATS_AddressRecord *ar,
701 struct GNUNET_ATS_Session *session)
703 GNUNET_break (NULL == ar->session);
704 ar->session = session;
709 * A session was destroyed, disassociate it from the
710 * given address record. If this was an incoming
711 * addess, destroy the address as well.
713 * @param ar address record to update information for
714 * @param session session handle
715 * @return #GNUNET_YES if the @a ar was destroyed because
716 * it was an incoming address,
717 * #GNUNET_NO if the @ar was kept because we can
718 * use it still to establish a new session
721 GNUNET_ATS_address_del_session (struct GNUNET_ATS_AddressRecord *ar,
722 struct GNUNET_ATS_Session *session)
724 GNUNET_assert (session == ar->session);
726 if (GNUNET_HELLO_address_check_option (ar->address,
727 GNUNET_HELLO_ADDRESS_INFO_INBOUND))
729 GNUNET_ATS_address_destroy (ar);
737 * We have updated performance statistics for a given address. Note
738 * that this function can be called for addresses that are currently
739 * in use as well as addresses that are valid but not actively in use.
740 * Furthermore, the peer may not even be connected to us right now (in
741 * which case the call may be ignored or the information may be stored
742 * for later use). Update bandwidth assignments.
744 * @param ar address record to update information for
745 * @param prop performance data for the address
748 GNUNET_ATS_address_update (struct GNUNET_ATS_AddressRecord *ar,
749 const struct GNUNET_ATS_Properties *prop)
751 struct GNUNET_ATS_SchedulingHandle *sh = ar->sh;
752 struct GNUNET_MQ_Envelope *ev;
753 struct AddressUpdateMessage *m;
755 LOG (GNUNET_ERROR_TYPE_DEBUG,
756 "Updating address for peer `%s', plugin `%s', session %p slot %u\n",
757 GNUNET_i2s (&ar->address->peer),
758 ar->address->transport_name,
761 GNUNET_break (GNUNET_ATS_NET_UNSPECIFIED != prop->scope);
762 GNUNET_ATS_properties_hton (&ar->properties,
765 return; /* disconnected, skip for now */
766 ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
767 m->session_id = htonl (ar->slot);
768 m->peer = ar->address->peer;
769 m->properties = ar->properties;
770 GNUNET_MQ_send (sh->mq,
776 * An address got destroyed, stop using it as a valid address.
778 * @param ar address to destroy
781 GNUNET_ATS_address_destroy (struct GNUNET_ATS_AddressRecord *ar)
783 struct GNUNET_ATS_SchedulingHandle *sh = ar->sh;
784 struct GNUNET_MQ_Envelope *ev;
785 struct AddressDestroyedMessage *m;
787 LOG (GNUNET_ERROR_TYPE_DEBUG,
788 "Deleting address for peer `%s', plugin `%s', slot %u session %p\n",
789 GNUNET_i2s (&ar->address->peer),
790 ar->address->transport_name,
793 GNUNET_break (NULL == ar->session);
795 ar->in_destroy = GNUNET_YES;
798 ev = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
799 m->session_id = htonl (ar->slot);
800 m->peer = ar->address->peer;
801 GNUNET_MQ_send (sh->mq, ev);
805 /* end of ats_api_scheduling.c */