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3 (C) 2010,2011 Christian Grothoff (and other contributing authors)
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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 #include "gnunet_ats_service.h"
30 #define DEBUG_ATS GNUNET_EXTRA_LOGGING
33 * Message in linked list we should send to the ATS service. The
34 * actual binary message follows this struct.
42 struct PendingMessage *next;
47 struct PendingMessage *prev;
50 * Size of the message.
55 * Is this the 'ATS_START' message?
62 * Information we track per session.
67 * Identity of the peer (just needed for error checking).
69 struct GNUNET_PeerIdentity peer;
74 struct Session *session;
77 * Set to GNUNET_YES if the slot is used.
84 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
86 struct GNUNET_ATS_SchedulingHandle
92 const struct GNUNET_CONFIGURATION_Handle *cfg;
95 * Callback to invoke on suggestions.
97 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
100 * Closure for 'suggest_cb'.
102 void *suggest_cb_cls;
105 * Connection to ATS service.
107 struct GNUNET_CLIENT_Connection *client;
110 * Head of list of messages for the ATS service.
112 struct PendingMessage *pending_head;
115 * Tail of list of messages for the ATS service
117 struct PendingMessage *pending_tail;
120 * Current request for transmission to ATS.
122 struct GNUNET_CLIENT_TransmitHandle *th;
125 * Array of session objects (we need to translate them to numbers and back
126 * for the protocol; the offset in the array is the session number on the
127 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
128 * Unused entries are also NULL.
130 struct SessionRecord *session_array;
133 * Task to trigger reconnect.
135 GNUNET_SCHEDULER_TaskIdentifier task;
138 * Size of the session array.
140 unsigned int session_array_size;
143 * Should we reconnect to ATS due to some serious error?
150 * Re-establish the connection to the ATS service.
152 * @param sh handle to use to re-connect.
155 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
159 * Re-establish the connection to the ATS service.
161 * @param cls handle to use to re-connect.
162 * @param tc scheduler context
165 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
167 struct GNUNET_ATS_SchedulingHandle *sh = cls;
169 sh->task = GNUNET_SCHEDULER_NO_TASK;
175 * Disconnect from ATS and then reconnect.
177 * @param sh our handle
180 force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
182 sh->reconnect = GNUNET_NO;
183 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
186 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
192 * Transmit messages from the message queue to the service
193 * (if there are any, and if we are not already trying).
195 * @param sh handle to use
198 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
202 * Type of a function to call when we receive a message
205 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
206 * @param msg message received, NULL on timeout or fatal error
209 process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg);
213 * We can now transmit a message to ATS. Do it.
215 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
216 * @param size number of bytes we can transmit to ATS
217 * @param buf where to copy the messages
218 * @return number of bytes copied into buf
221 transmit_message_to_ats (void *cls, size_t size, void *buf)
223 struct GNUNET_ATS_SchedulingHandle *sh = cls;
224 struct PendingMessage *p;
229 if ((size == 0) || (buf == NULL))
231 force_reconnect (sh);
236 while ((NULL != (p = sh->pending_head)) && (p->size <= size))
238 memcpy (&cbuf[ret], &p[1], p->size);
241 GNUNET_CONTAINER_DLL_remove (sh->pending_head, sh->pending_tail, p);
242 if (GNUNET_YES == p->is_init)
243 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
244 GNUNET_TIME_UNIT_FOREVER_REL);
253 * Transmit messages from the message queue to the service
254 * (if there are any, and if we are not already trying).
256 * @param sh handle to use
259 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
261 struct PendingMessage *p;
265 if (NULL == (p = sh->pending_head))
267 if (NULL == sh->client)
268 return; /* currently reconnecting */
270 GNUNET_CLIENT_notify_transmit_ready (sh->client, p->size,
271 GNUNET_TIME_UNIT_FOREVER_REL,
272 GNUNET_NO, &transmit_message_to_ats,
278 * Find the session object corresponding to the given session ID.
280 * @param sh our handle
281 * @param session_id current session ID
282 * @param peer peer the session belongs to
283 * @return the session object (or NULL)
285 static struct Session *
286 find_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
287 const struct GNUNET_PeerIdentity *peer)
290 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
291 "Find session %u from peer %s in %p\n",
292 (unsigned int) session_id,
296 if (session_id >= sh->session_array_size)
303 if (sh->session_array[session_id].session == NULL)
306 memcmp (peer, &sh->session_array[session_id].peer,
307 sizeof (struct GNUNET_PeerIdentity)));
312 memcmp (peer, &sh->session_array[session_id].peer,
313 sizeof (struct GNUNET_PeerIdentity)))
316 sh->reconnect = GNUNET_YES;
319 return sh->session_array[session_id].session;
324 * Get the ID for the given session object. If we do not have an ID for
325 * the given session object, allocate one.
327 * @param sh our handle
328 * @param session session object
329 * @param peer peer the session belongs to
330 * @return the session id
333 get_session_id (struct GNUNET_ATS_SchedulingHandle *sh, struct Session *session,
334 const struct GNUNET_PeerIdentity *peer)
340 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
341 "Get session ID for session %p from peer %s in %p\n",
349 for (i = 1; i < sh->session_array_size; i++)
351 if (session == sh->session_array[i].session)
353 GNUNET_assert (0 == memcmp (peer, &sh->session_array[i].peer,
354 sizeof (struct GNUNET_PeerIdentity)));
357 if ((f == 0) && (sh->session_array[i].slot_used == GNUNET_NO))
362 f = sh->session_array_size;
363 GNUNET_array_grow (sh->session_array, sh->session_array_size,
364 sh->session_array_size * 2);
366 GNUNET_assert (f > 0);
367 sh->session_array[f].session = session;
368 sh->session_array[f].peer = *peer;
369 sh->session_array[f].slot_used = GNUNET_YES;
371 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
372 "Assigning session ID %u for session %p of peer %s in %p\n",
383 * Remove the session of the given session ID from the session
384 * table (it is no longer valid).
386 * @param sh our handle
387 * @param session_id identifies session that is no longer valid
388 * @param peer peer the session belongs to
391 remove_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
392 const struct GNUNET_PeerIdentity *peer)
395 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
396 "Remove sessionID %u from peer %s in %p\n",
397 (unsigned int) session_id,
403 GNUNET_assert (session_id < sh->session_array_size);
404 GNUNET_assert (GNUNET_YES == sh->session_array[session_id].slot_used);
405 GNUNET_assert (0 == memcmp (peer, &sh->session_array[session_id].peer,
406 sizeof (struct GNUNET_PeerIdentity)));
407 sh->session_array[session_id].session = NULL;
412 * Release the session slot from the session table (ATS service is
413 * also done using it).
415 * @param sh our handle
416 * @param session_id identifies session that is no longer valid
417 * @param peer peer the session belongs to
420 release_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
421 const struct GNUNET_PeerIdentity *peer)
424 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
425 "Release sessionID %u from peer %s in %p\n",
426 (unsigned int) session_id,
430 if (session_id >= sh->session_array_size)
433 sh->reconnect = GNUNET_YES;
437 /* this slot should have been removed from remove_session before */
438 GNUNET_assert (sh->session_array[session_id].session == NULL);
440 if (0 != memcmp (peer, &sh->session_array[session_id].peer,
441 sizeof (struct GNUNET_PeerIdentity)))
444 sh->reconnect = GNUNET_YES;
447 sh->session_array[session_id].slot_used = GNUNET_NO;
448 memset (&sh->session_array[session_id].peer, 0,
449 sizeof (struct GNUNET_PeerIdentity));
454 process_release_message (struct GNUNET_ATS_SchedulingHandle *sh,
455 const struct SessionReleaseMessage *srm)
457 release_session (sh, ntohl (srm->session_id), &srm->peer);
462 * Type of a function to call when we receive a message
465 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
466 * @param msg message received, NULL on timeout or fatal error
469 process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg)
471 struct GNUNET_ATS_SchedulingHandle *sh = cls;
472 const struct AddressSuggestionMessage *m;
473 const struct GNUNET_ATS_Information *atsi;
474 const char *plugin_address;
475 const char *plugin_name;
476 uint16_t plugin_address_length;
477 uint16_t plugin_name_length;
479 struct GNUNET_HELLO_Address address;
484 force_reconnect (sh);
487 if ((ntohs (msg->type) == GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE) &&
488 (ntohs (msg->size) == sizeof (struct SessionReleaseMessage)))
490 process_release_message (sh, (const struct SessionReleaseMessage *) msg);
491 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
492 GNUNET_TIME_UNIT_FOREVER_REL);
493 if (GNUNET_YES == sh->reconnect)
494 force_reconnect (sh);
497 if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
498 (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)))
501 force_reconnect (sh);
504 m = (const struct AddressSuggestionMessage *) msg;
505 ats_count = ntohl (m->ats_count);
506 plugin_address_length = ntohs (m->address_length);
507 atsi = (const struct GNUNET_ATS_Information *) &m[1];
508 plugin_address = (const char *) &atsi[ats_count];
509 plugin_name = &plugin_address[plugin_address_length];
510 plugin_name_length = ntohs (m->plugin_name_length);
511 if ((plugin_address_length + plugin_name_length +
512 ats_count * sizeof (struct GNUNET_ATS_Information) +
513 sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
515 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information))
516 || (plugin_name[plugin_name_length - 1] != '\0'))
519 force_reconnect (sh);
522 uint32_t session_id = ntohl (m->session_id);
528 s = find_session (sh, session_id, &m->peer);
532 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
533 "ATS tries to use outdated session `%s'\n",
534 GNUNET_i2s(&m->peer));
539 address.peer = m->peer;
540 address.address = plugin_address;
541 address.address_length = plugin_address_length;
542 address.transport_name = plugin_name;
543 sh->suggest_cb (sh->suggest_cb_cls, &address, s, m->bandwidth_out,
544 m->bandwidth_in, atsi, ats_count);
546 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
547 GNUNET_TIME_UNIT_FOREVER_REL);
548 if (GNUNET_YES == sh->reconnect)
549 force_reconnect (sh);
554 * Re-establish the connection to the ATS service.
556 * @param sh handle to use to re-connect.
559 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
561 struct PendingMessage *p;
562 struct ClientStartMessage *init;
564 GNUNET_assert (NULL == sh->client);
565 sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
566 GNUNET_assert (NULL != sh->client);
567 if ((NULL == (p = sh->pending_head)) || (GNUNET_YES != p->is_init))
569 p = GNUNET_malloc (sizeof (struct PendingMessage) +
570 sizeof (struct ClientStartMessage));
571 p->size = sizeof (struct ClientStartMessage);
572 p->is_init = GNUNET_YES;
573 init = (struct ClientStartMessage *) &p[1];
574 init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
575 init->header.size = htons (sizeof (struct ClientStartMessage));
576 init->start_flag = htonl (START_FLAG_SCHEDULING);
577 GNUNET_CONTAINER_DLL_insert (sh->pending_head, sh->pending_tail, p);
584 * Initialize the ATS subsystem.
586 * @param cfg configuration to use
587 * @param suggest_cb notification to call whenever the suggestation changed
588 * @param suggest_cb_cls closure for 'suggest_cb'
589 * @return ats context
591 struct GNUNET_ATS_SchedulingHandle *
592 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
593 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
594 void *suggest_cb_cls)
596 struct GNUNET_ATS_SchedulingHandle *sh;
598 sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
600 sh->suggest_cb = suggest_cb;
601 sh->suggest_cb_cls = suggest_cb_cls;
602 GNUNET_array_grow (sh->session_array, sh->session_array_size, 4);
609 * Client is done with ATS scheduling, release resources.
611 * @param sh handle to release
614 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
616 struct PendingMessage *p;
618 while (NULL != (p = sh->pending_head))
620 GNUNET_CONTAINER_DLL_remove (sh->pending_head, sh->pending_tail, p);
623 if (NULL != sh->client)
625 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
628 if (GNUNET_SCHEDULER_NO_TASK != sh->task)
630 GNUNET_SCHEDULER_cancel (sh->task);
631 sh->task = GNUNET_SCHEDULER_NO_TASK;
633 GNUNET_array_grow (sh->session_array, sh->session_array_size, 0);
639 * We would like to establish a new connection with a peer. ATS
640 * should suggest a good address to begin with.
643 * @param peer identity of the peer we need an address for
646 GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
647 const struct GNUNET_PeerIdentity *peer)
649 struct PendingMessage *p;
650 struct RequestAddressMessage *m;
652 p = GNUNET_malloc (sizeof (struct PendingMessage) +
653 sizeof (struct RequestAddressMessage));
654 p->size = sizeof (struct RequestAddressMessage);
655 p->is_init = GNUNET_NO;
656 m = (struct RequestAddressMessage *) &p[1];
657 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
658 m->header.size = htons (sizeof (struct RequestAddressMessage));
659 m->reserved = htonl (0);
661 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
667 * We would like to stop receiving address updates for this peer
670 * @param peer identity of the peer
673 GNUNET_ATS_suggest_address_cancel (struct GNUNET_ATS_SchedulingHandle *sh,
674 const struct GNUNET_PeerIdentity *peer)
676 struct PendingMessage *p;
677 struct RequestAddressMessage *m;
679 p = GNUNET_malloc (sizeof (struct PendingMessage) +
680 sizeof (struct RequestAddressMessage));
681 p->size = sizeof (struct RequestAddressMessage);
682 p->is_init = GNUNET_NO;
683 m = (struct RequestAddressMessage *) &p[1];
684 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS_CANCEL);
685 m->header.size = htons (sizeof (struct RequestAddressMessage));
686 m->reserved = htonl (0);
688 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
693 * We have updated performance statistics for a given address. Note
694 * that this function can be called for addresses that are currently
695 * in use as well as addresses that are valid but not actively in use.
696 * Furthermore, the peer may not even be connected to us right now (in
697 * which case the call may be ignored or the information may be stored
698 * for later use). Update bandwidth assignments.
701 * @param address the address
702 * @param session session handle (if available)
703 * @param ats performance data for the address
704 * @param ats_count number of performance records in 'ats'
707 GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
708 const struct GNUNET_HELLO_Address *address,
709 struct Session *session,
710 const struct GNUNET_ATS_Information *ats,
713 struct PendingMessage *p;
714 struct AddressUpdateMessage *m;
715 struct GNUNET_ATS_Information *am;
720 namelen = (address->transport_name == NULL) ? 0 : strlen (address->transport_name) + 1;
722 sizeof (struct AddressUpdateMessage) + address->address_length +
723 ats_count * sizeof (struct GNUNET_ATS_Information) + namelen;
724 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
725 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
726 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
728 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)))
734 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
736 p->is_init = GNUNET_NO;
737 m = (struct AddressUpdateMessage *) &p[1];
738 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
739 m->header.size = htons (msize);
740 m->ats_count = htonl (ats_count);
741 m->peer = address->peer;
742 m->address_length = htons (address->address_length);
743 m->plugin_name_length = htons (namelen);
744 m->session_id = htonl (get_session_id (sh, session, &address->peer));
745 am = (struct GNUNET_ATS_Information *) &m[1];
746 memcpy (am, ats, ats_count * sizeof (struct GNUNET_ATS_Information));
747 pm = (char *) &am[ats_count];
748 memcpy (pm, address->address, address->address_length);
749 memcpy (&pm[address->address_length], address->transport_name, namelen);
750 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
756 * An address is now in use or not used any more.
759 * @param address the address
760 * @param session session handle
761 * @param in_use GNUNET_YES if this address is now used, GNUNET_NO
762 * if address is not used any more
765 GNUNET_ATS_address_in_use (struct GNUNET_ATS_SchedulingHandle *sh,
766 const struct GNUNET_HELLO_Address *address,
767 struct Session *session,
770 struct PendingMessage *p;
771 struct AddressUseMessage *m;
776 GNUNET_assert (NULL != address);
777 namelen = (address->transport_name == NULL) ? 0 : strlen (address->transport_name) + 1;
778 msize = sizeof (struct AddressUseMessage) + address->address_length + namelen;
779 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
780 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
781 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
787 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
789 p->is_init = GNUNET_NO;
790 m = (struct AddressUseMessage *) &p[1];
791 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_IN_USE);
792 m->header.size = htons (msize);
793 m->peer = address->peer;
794 m->in_use = htons (in_use);
795 m->address_length = htons (address->address_length);
796 m->plugin_name_length = htons (namelen);
797 m->session_id = htonl (get_session_id (sh, session, &address->peer));
799 memcpy (pm, address->address, address->address_length);
800 memcpy (&pm[address->address_length], address->transport_name, namelen);
801 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
807 * A session got destroyed, stop including it as a valid address.
810 * @param address the address
811 * @param session session handle that is no longer valid
814 GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
815 const struct GNUNET_HELLO_Address *address,
816 struct Session *session)
818 struct PendingMessage *p;
819 struct AddressDestroyedMessage *m;
825 namelen = (address->transport_name == NULL) ? 0 : strlen (address->transport_name) + 1;
826 msize = sizeof (struct AddressDestroyedMessage) + address->address_length + namelen;
827 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
828 (address->address_length >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
829 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
835 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
837 p->is_init = GNUNET_NO;
838 m = (struct AddressDestroyedMessage *) &p[1];
839 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
840 m->header.size = htons (msize);
841 m->reserved = htonl (0);
842 m->peer = address->peer;
843 m->address_length = htons (address->address_length);
844 m->plugin_name_length = htons (namelen);
845 session_id = get_session_id (sh, session, &address->peer);
846 m->session_id = htonl (session_id);
848 memcpy (pm, address->address, address->address_length);
849 memcpy (&pm[address->address_length], address->transport_name, namelen);
850 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
852 remove_session (sh, session_id, &address->peer);
855 /* end of ats_api_scheduling.c */