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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"
32 * Message in linked list we should send to the ATS service. The
33 * actual binary message follows this struct.
41 struct PendingMessage *next;
46 struct PendingMessage *prev;
49 * Size of the message.
54 * Is this the 'ATS_START' message?
61 * Information we track per session.
66 * Identity of the peer (just needed for error checking).
68 struct GNUNET_PeerIdentity peer;
73 struct Session *session;
76 * Set to GNUNET_YES if the slot is used.
83 * Handle to the ATS subsystem for bandwidth/transport scheduling information.
85 struct GNUNET_ATS_SchedulingHandle
91 const struct GNUNET_CONFIGURATION_Handle *cfg;
94 * Callback to invoke on suggestions.
96 GNUNET_ATS_AddressSuggestionCallback suggest_cb;
99 * Closure for 'suggest_cb'.
101 void *suggest_cb_cls;
104 * Connection to ATS service.
106 struct GNUNET_CLIENT_Connection *client;
109 * Head of list of messages for the ATS service.
111 struct PendingMessage *pending_head;
114 * Tail of list of messages for the ATS service
116 struct PendingMessage *pending_tail;
119 * Current request for transmission to ATS.
121 struct GNUNET_CLIENT_TransmitHandle *th;
124 * Array of session objects (we need to translate them to numbers and back
125 * for the protocol; the offset in the array is the session number on the
126 * network). Index 0 is always NULL and reserved to represent the NULL pointer.
127 * Unused entries are also NULL.
129 struct SessionRecord *session_array;
132 * Task to trigger reconnect.
134 GNUNET_SCHEDULER_TaskIdentifier task;
137 * Size of the session array.
139 unsigned int session_array_size;
145 * Re-establish the connection to the ATS service.
147 * @param sh handle to use to re-connect.
150 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
155 * Re-establish the connection to the ATS service.
157 * @param cls handle to use to re-connect.
158 * @param tc scheduler context
161 reconnect_task (void *cls,
162 const struct GNUNET_SCHEDULER_TaskContext *tc)
164 struct GNUNET_ATS_SchedulingHandle *sh = cls;
166 sh->task = GNUNET_SCHEDULER_NO_TASK;
172 * Transmit messages from the message queue to the service
173 * (if there are any, and if we are not already trying).
175 * @param sh handle to use
178 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
182 * Type of a function to call when we receive a message
185 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
186 * @param msg message received, NULL on timeout or fatal error
189 process_ats_message (void *cls,
190 const struct GNUNET_MessageHeader *msg);
194 * We can now transmit a message to ATS. Do it.
196 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
197 * @param size number of bytes we can transmit to ATS
198 * @param buf where to copy the messages
199 * @return number of bytes copied into buf
202 transmit_message_to_ats (void *cls,
206 struct GNUNET_ATS_SchedulingHandle *sh = cls;
207 struct PendingMessage *p;
212 if ( (size == 0) || (buf == NULL))
214 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
216 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
217 &reconnect_task, sh);
222 while ( (NULL != (p = sh->pending_head)) &&
225 memcpy (&cbuf[ret], &p[1], p->size);
228 GNUNET_CONTAINER_DLL_remove (sh->pending_head,
231 if (GNUNET_YES == p->is_init)
232 GNUNET_CLIENT_receive (sh->client,
233 &process_ats_message, sh,
234 GNUNET_TIME_UNIT_FOREVER_REL);
243 * Transmit messages from the message queue to the service
244 * (if there are any, and if we are not already trying).
246 * @param sh handle to use
249 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
251 struct PendingMessage *p;
255 if (NULL == (p = sh->pending_head))
257 if (NULL == sh->client)
258 return; /* currently reconnecting */
259 sh->th = GNUNET_CLIENT_notify_transmit_ready (sh->client,
261 GNUNET_TIME_UNIT_FOREVER_REL,
263 &transmit_message_to_ats, sh);
268 * Find the session object corresponding to the given session ID.
270 * @param sh our handle
271 * @param session_id current session ID
272 * @param peer peer the session belongs to
273 * @return the session object (or NULL)
275 static struct Session*
276 find_session (struct GNUNET_ATS_SchedulingHandle *sh,
278 const struct GNUNET_PeerIdentity *peer)
280 if (session_id >= sh->session_array_size)
287 GNUNET_assert (0 == memcmp (peer,
288 &sh->session_array[session_id].peer,
289 sizeof (struct GNUNET_PeerIdentity)));
290 return sh->session_array[session_id].session;
295 * Get the ID for the given session object. If we do not have an ID for
296 * the given session object, allocate one.
298 * @param sh our handle
299 * @param session session object
300 * @param peer peer the session belongs to
301 * @return the session id
304 get_session_id (struct GNUNET_ATS_SchedulingHandle *sh,
305 struct Session *session,
306 const struct GNUNET_PeerIdentity *peer)
314 for (i=1;i<sh->session_array_size;i++)
316 if (session == sh->session_array[i].session)
318 GNUNET_assert (0 == memcmp (peer,
319 &sh->session_array[i].peer,
320 sizeof (struct GNUNET_PeerIdentity)));
324 (sh->session_array[i].slot_used == GNUNET_NO) )
329 f = sh->session_array_size;
330 GNUNET_array_grow (sh->session_array,
331 sh->session_array_size,
332 sh->session_array_size * 2);
334 GNUNET_assert (f > 0);
335 sh->session_array[f].session = session;
336 sh->session_array[f].peer = *peer;
337 sh->session_array[f].slot_used = GNUNET_YES;
343 * Remove the session of the given session ID from the session
344 * table (it is no longer valid).
346 * @param sh our handle
347 * @param session_id identifies session that is no longer valid
348 * @param peer peer the session belongs to
351 remove_session (struct GNUNET_ATS_SchedulingHandle *sh,
353 const struct GNUNET_PeerIdentity *peer)
357 GNUNET_assert (session_id < sh->session_array_size);
358 GNUNET_assert (GNUNET_YES == sh->session_array[session_id].slot_used);
359 GNUNET_assert (0 == memcmp (peer,
360 &sh->session_array[session_id].peer,
361 sizeof (struct GNUNET_PeerIdentity)));
362 sh->session_array[session_id].session = NULL;
367 * Release the session slot from the session table (ATS service is
368 * also done using it).
370 * @param sh our handle
371 * @param session_id identifies session that is no longer valid
372 * @param peer peer the session belongs to
375 release_session (struct GNUNET_ATS_SchedulingHandle *sh,
377 const struct GNUNET_PeerIdentity *peer)
379 GNUNET_assert (session_id < sh->session_array_size);
380 GNUNET_assert (0 == memcmp (peer,
381 &sh->session_array[session_id].peer,
382 sizeof (struct GNUNET_PeerIdentity)));
383 sh->session_array[session_id].slot_used = GNUNET_NO;
384 memset (&sh->session_array[session_id].peer,
386 sizeof (struct GNUNET_PeerIdentity));
391 process_release_message (struct GNUNET_ATS_SchedulingHandle *sh,
392 const struct SessionReleaseMessage *srm)
395 ntohl (srm->session_id),
401 * Type of a function to call when we receive a message
404 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
405 * @param msg message received, NULL on timeout or fatal error
408 process_ats_message (void *cls,
409 const struct GNUNET_MessageHeader *msg)
411 struct GNUNET_ATS_SchedulingHandle *sh = cls;
412 const struct AddressSuggestionMessage *m;
413 const struct GNUNET_ATS_Information *atsi;
415 const char *plugin_name;
416 uint16_t address_length;
417 uint16_t plugin_name_length;
422 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
424 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
425 &reconnect_task, sh);
428 if ( (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE) &&
429 (ntohs (msg->size) == sizeof (struct SessionReleaseMessage)) )
431 process_release_message (sh,
432 (const struct SessionReleaseMessage*) msg);
433 GNUNET_CLIENT_receive (sh->client,
434 &process_ats_message, sh,
435 GNUNET_TIME_UNIT_FOREVER_REL);
438 if ( (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
439 (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)) )
442 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
444 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
445 &reconnect_task, sh);
448 m = (const struct AddressSuggestionMessage*) msg;
449 ats_count = ntohl (m->ats_count);
450 address_length = ntohs (m->address_length);
451 atsi = (const struct GNUNET_ATS_Information*) &m[1];
452 address = (const char*) &atsi[ats_count];
453 plugin_name = &address[address_length];
454 plugin_name_length = ntohs (m->plugin_name_length);
455 if ( (address_length +
457 ats_count * sizeof (struct GNUNET_ATS_Information) +
458 sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
459 (ats_count > GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)) ||
460 (plugin_name[plugin_name_length - 1] != '\0') )
463 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
465 sh->task = GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS,
466 &reconnect_task, sh);
469 sh->suggest_cb (sh->suggest_cb_cls,
472 address, address_length,
473 find_session (sh, ntohl (m->session_id), &m->peer),
478 GNUNET_CLIENT_receive (sh->client,
479 &process_ats_message, sh,
480 GNUNET_TIME_UNIT_FOREVER_REL);
485 * Re-establish the connection to the ATS service.
487 * @param sh handle to use to re-connect.
490 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
492 struct PendingMessage *p;
493 struct ClientStartMessage *init;
495 GNUNET_assert (NULL == sh->client);
496 sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
497 GNUNET_assert (NULL != sh->client);
498 if ( (NULL == (p = sh->pending_head)) ||
499 (GNUNET_YES != p->is_init) )
501 p = GNUNET_malloc (sizeof (struct PendingMessage) +
502 sizeof (struct ClientStartMessage));
503 p->size = sizeof (struct ClientStartMessage);
504 p->is_init = GNUNET_YES;
505 init = (struct ClientStartMessage *) &p[1];
506 init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
507 init->header.size = htons (sizeof (struct ClientStartMessage));
508 init->start_flag = htonl (START_FLAG_SCHEDULING);
509 GNUNET_CONTAINER_DLL_insert (sh->pending_head,
518 * Initialize the ATS subsystem.
520 * @param cfg configuration to use
521 * @param suggest_cb notification to call whenever the suggestation changed
522 * @param suggest_cb_cls closure for 'suggest_cb'
523 * @return ats context
525 struct GNUNET_ATS_SchedulingHandle *
526 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
527 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
528 void *suggest_cb_cls)
530 struct GNUNET_ATS_SchedulingHandle *sh;
532 sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
534 sh->suggest_cb = suggest_cb;
535 sh->suggest_cb_cls = suggest_cb_cls;
536 GNUNET_array_grow (sh->session_array,
537 sh->session_array_size,
545 * Client is done with ATS scheduling, release resources.
547 * @param sh handle to release
550 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
552 struct PendingMessage *p;
554 while (NULL != (p = sh->pending_head))
556 GNUNET_CONTAINER_DLL_remove (sh->pending_head,
561 if (NULL != sh->client)
563 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
566 if (GNUNET_SCHEDULER_NO_TASK != sh->task)
568 GNUNET_SCHEDULER_cancel (sh->task);
569 sh->task = GNUNET_SCHEDULER_NO_TASK;
571 GNUNET_array_grow (sh->session_array,
572 sh->session_array_size,
579 * We would like to establish a new connection with a peer. ATS
580 * should suggest a good address to begin with.
583 * @param peer identity of the peer we need an address for
586 GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
587 const struct GNUNET_PeerIdentity *peer)
589 struct PendingMessage *p;
590 struct RequestAddressMessage *m;
592 p = GNUNET_malloc (sizeof (struct PendingMessage) +
593 sizeof (struct RequestAddressMessage));
594 p->size = sizeof (struct RequestAddressMessage);
595 p->is_init = GNUNET_NO;
596 m = (struct RequestAddressMessage*) &p[1];
597 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
598 m->header.size = htons (sizeof (struct RequestAddressMessage));
599 m->reserved = htonl (0);
601 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
609 * We have updated performance statistics for a given address. Note
610 * that this function can be called for addresses that are currently
611 * in use as well as addresses that are valid but not actively in use.
612 * Furthermore, the peer may not even be connected to us right now (in
613 * which case the call may be ignored or the information may be stored
614 * for later use). Update bandwidth assignments.
617 * @param peer identity of the new peer
618 * @param plugin_name name of the transport plugin
619 * @param plugin_addr address (if available)
620 * @param plugin_addr_len number of bytes in plugin_addr
621 * @param session session handle (if available)
622 * @param ats performance data for the address
623 * @param ats_count number of performance records in 'ats'
626 GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
627 const struct GNUNET_PeerIdentity *peer,
628 const char *plugin_name,
629 const void *plugin_addr, size_t plugin_addr_len,
630 struct Session *session,
631 const struct GNUNET_ATS_Information *ats,
634 struct PendingMessage *p;
635 struct AddressUpdateMessage *m;
636 struct GNUNET_ATS_Information *am;
641 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
642 msize = sizeof (struct AddressUpdateMessage) + plugin_addr_len +
643 ats_count * sizeof (struct GNUNET_ATS_Information) + namelen;
644 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
645 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
646 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
647 (ats_count >= GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)) )
652 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
654 p->is_init = GNUNET_NO;
655 m = (struct AddressUpdateMessage*) &p[1];
656 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
657 m->header.size = htons (msize);
658 m->ats_count = htonl (ats_count);
660 m->address_length = htons (plugin_addr_len);
661 m->plugin_name_length = htons (namelen);
662 m->session_id = htonl (get_session_id (sh, session, peer));
663 am = (struct GNUNET_ATS_Information*) &m[1];
664 memcpy (am, ats, ats_count * sizeof (struct GNUNET_ATS_Information));
665 pm = (char *) &am[ats_count];
666 memcpy (pm, plugin_addr, plugin_addr_len);
667 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
668 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
676 * A session got destroyed, stop including it as a valid address.
679 * @param peer identity of the peer
680 * @param plugin_name name of the transport plugin
681 * @param plugin_addr address (if available)
682 * @param plugin_addr_len number of bytes in plugin_addr
683 * @param session session handle that is no longer valid
686 GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
687 const struct GNUNET_PeerIdentity *peer,
688 const char *plugin_name,
689 const void *plugin_addr,
690 size_t plugin_addr_len,
691 struct Session *session)
693 struct PendingMessage *p;
694 struct AddressDestroyedMessage *m;
700 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
701 msize = sizeof (struct AddressDestroyedMessage) + plugin_addr_len +
703 if ( (msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
704 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
705 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) )
710 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
712 p->is_init = GNUNET_NO;
713 m = (struct AddressDestroyedMessage*) &p[1];
714 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
715 m->header.size = htons (msize);
716 m->reserved = htonl (0);
718 m->address_length = htons (plugin_addr_len);
719 m->plugin_name_length = htons (namelen);
720 m->session_id = htonl (session_id = get_session_id (sh, session, peer));
722 memcpy (pm, plugin_addr, plugin_addr_len);
723 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
724 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head,
728 remove_session (sh, session_id, peer);
731 /* end of ats_api_scheduling.c */