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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;
142 * Should we reconnect to ATS due to some serious error?
149 * Re-establish the connection to the ATS service.
151 * @param sh handle to use to re-connect.
154 reconnect (struct GNUNET_ATS_SchedulingHandle *sh);
158 * Re-establish the connection to the ATS service.
160 * @param cls handle to use to re-connect.
161 * @param tc scheduler context
164 reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
166 struct GNUNET_ATS_SchedulingHandle *sh = cls;
168 sh->task = GNUNET_SCHEDULER_NO_TASK;
174 * Disconnect from ATS and then reconnect.
176 * @param sh our handle
179 force_reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
181 sh->reconnect = GNUNET_NO;
182 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
185 GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
191 * Transmit messages from the message queue to the service
192 * (if there are any, and if we are not already trying).
194 * @param sh handle to use
197 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh);
201 * Type of a function to call when we receive a message
204 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
205 * @param msg message received, NULL on timeout or fatal error
208 process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg);
212 * We can now transmit a message to ATS. Do it.
214 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
215 * @param size number of bytes we can transmit to ATS
216 * @param buf where to copy the messages
217 * @return number of bytes copied into buf
220 transmit_message_to_ats (void *cls, size_t size, void *buf)
222 struct GNUNET_ATS_SchedulingHandle *sh = cls;
223 struct PendingMessage *p;
228 if ((size == 0) || (buf == NULL))
230 force_reconnect (sh);
235 while ((NULL != (p = sh->pending_head)) && (p->size <= size))
237 memcpy (&cbuf[ret], &p[1], p->size);
240 GNUNET_CONTAINER_DLL_remove (sh->pending_head, sh->pending_tail, p);
241 if (GNUNET_YES == p->is_init)
242 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
243 GNUNET_TIME_UNIT_FOREVER_REL);
252 * Transmit messages from the message queue to the service
253 * (if there are any, and if we are not already trying).
255 * @param sh handle to use
258 do_transmit (struct GNUNET_ATS_SchedulingHandle *sh)
260 struct PendingMessage *p;
264 if (NULL == (p = sh->pending_head))
266 if (NULL == sh->client)
267 return; /* currently reconnecting */
269 GNUNET_CLIENT_notify_transmit_ready (sh->client, p->size,
270 GNUNET_TIME_UNIT_FOREVER_REL,
271 GNUNET_NO, &transmit_message_to_ats,
277 * Find the session object corresponding to the given session ID.
279 * @param sh our handle
280 * @param session_id current session ID
281 * @param peer peer the session belongs to
282 * @return the session object (or NULL)
284 static struct Session *
285 find_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
286 const struct GNUNET_PeerIdentity *peer)
288 if (session_id >= sh->session_array_size)
296 memcmp (peer, &sh->session_array[session_id].peer,
297 sizeof (struct GNUNET_PeerIdentity)))
300 sh->reconnect = GNUNET_YES;
303 return sh->session_array[session_id].session;
308 * Get the ID for the given session object. If we do not have an ID for
309 * the given session object, allocate one.
311 * @param sh our handle
312 * @param session session object
313 * @param peer peer the session belongs to
314 * @return the session id
317 get_session_id (struct GNUNET_ATS_SchedulingHandle *sh, struct Session *session,
318 const struct GNUNET_PeerIdentity *peer)
326 for (i = 1; i < sh->session_array_size; i++)
328 if (session == sh->session_array[i].session)
331 memcmp (peer, &sh->session_array[i].peer,
332 sizeof (struct GNUNET_PeerIdentity)));
335 if ((f == 0) && (sh->session_array[i].slot_used == GNUNET_NO))
340 f = sh->session_array_size;
341 GNUNET_array_grow (sh->session_array, sh->session_array_size,
342 sh->session_array_size * 2);
344 GNUNET_assert (f > 0);
345 sh->session_array[f].session = session;
346 sh->session_array[f].peer = *peer;
347 sh->session_array[f].slot_used = GNUNET_YES;
353 * Remove the session of the given session ID from the session
354 * table (it is no longer valid).
356 * @param sh our handle
357 * @param session_id identifies session that is no longer valid
358 * @param peer peer the session belongs to
361 remove_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
362 const struct GNUNET_PeerIdentity *peer)
366 GNUNET_assert (session_id < sh->session_array_size);
367 GNUNET_assert (GNUNET_YES == sh->session_array[session_id].slot_used);
369 memcmp (peer, &sh->session_array[session_id].peer,
370 sizeof (struct GNUNET_PeerIdentity)));
371 sh->session_array[session_id].session = NULL;
376 * Release the session slot from the session table (ATS service is
377 * also done using it).
379 * @param sh our handle
380 * @param session_id identifies session that is no longer valid
381 * @param peer peer the session belongs to
384 release_session (struct GNUNET_ATS_SchedulingHandle *sh, uint32_t session_id,
385 const struct GNUNET_PeerIdentity *peer)
387 if (session_id >= sh->session_array_size)
390 sh->reconnect = GNUNET_YES;
394 memcmp (peer, &sh->session_array[session_id].peer,
395 sizeof (struct GNUNET_PeerIdentity)))
398 sh->reconnect = GNUNET_YES;
401 sh->session_array[session_id].slot_used = GNUNET_NO;
402 memset (&sh->session_array[session_id].peer, 0,
403 sizeof (struct GNUNET_PeerIdentity));
408 process_release_message (struct GNUNET_ATS_SchedulingHandle *sh,
409 const struct SessionReleaseMessage *srm)
411 release_session (sh, ntohl (srm->session_id), &srm->peer);
416 * Type of a function to call when we receive a message
419 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
420 * @param msg message received, NULL on timeout or fatal error
423 process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg)
425 struct GNUNET_ATS_SchedulingHandle *sh = cls;
426 const struct AddressSuggestionMessage *m;
427 const struct GNUNET_ATS_Information *atsi;
429 const char *plugin_name;
430 uint16_t address_length;
431 uint16_t plugin_name_length;
436 force_reconnect (sh);
439 if ((ntohs (msg->type) == GNUNET_MESSAGE_TYPE_ATS_SESSION_RELEASE) &&
440 (ntohs (msg->size) == sizeof (struct SessionReleaseMessage)))
442 process_release_message (sh, (const struct SessionReleaseMessage *) msg);
443 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
444 GNUNET_TIME_UNIT_FOREVER_REL);
445 if (GNUNET_YES == sh->reconnect)
446 force_reconnect (sh);
449 if ((ntohs (msg->type) != GNUNET_MESSAGE_TYPE_ATS_ADDRESS_SUGGESTION) ||
450 (ntohs (msg->size) <= sizeof (struct AddressSuggestionMessage)))
453 force_reconnect (sh);
456 m = (const struct AddressSuggestionMessage *) msg;
457 ats_count = ntohl (m->ats_count);
458 address_length = ntohs (m->address_length);
459 atsi = (const struct GNUNET_ATS_Information *) &m[1];
460 address = (const char *) &atsi[ats_count];
461 plugin_name = &address[address_length];
462 plugin_name_length = ntohs (m->plugin_name_length);
463 if ((address_length + plugin_name_length +
464 ats_count * sizeof (struct GNUNET_ATS_Information) +
465 sizeof (struct AddressSuggestionMessage) != ntohs (msg->size)) ||
467 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information))
468 || (plugin_name[plugin_name_length - 1] != '\0'))
471 force_reconnect (sh);
474 sh->suggest_cb (sh->suggest_cb_cls, &m->peer, plugin_name, address,
475 address_length, find_session (sh, ntohl (m->session_id),
476 &m->peer), m->bandwidth_out,
477 m->bandwidth_in, atsi, ats_count);
478 GNUNET_CLIENT_receive (sh->client, &process_ats_message, sh,
479 GNUNET_TIME_UNIT_FOREVER_REL);
480 if (GNUNET_YES == sh->reconnect)
481 force_reconnect (sh);
486 * Re-establish the connection to the ATS service.
488 * @param sh handle to use to re-connect.
491 reconnect (struct GNUNET_ATS_SchedulingHandle *sh)
493 struct PendingMessage *p;
494 struct ClientStartMessage *init;
496 GNUNET_assert (NULL == sh->client);
497 sh->client = GNUNET_CLIENT_connect ("ats", sh->cfg);
498 GNUNET_assert (NULL != sh->client);
499 if ((NULL == (p = sh->pending_head)) || (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, sh->pending_tail, p);
516 * Initialize the ATS subsystem.
518 * @param cfg configuration to use
519 * @param suggest_cb notification to call whenever the suggestation changed
520 * @param suggest_cb_cls closure for 'suggest_cb'
521 * @return ats context
523 struct GNUNET_ATS_SchedulingHandle *
524 GNUNET_ATS_scheduling_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
525 GNUNET_ATS_AddressSuggestionCallback suggest_cb,
526 void *suggest_cb_cls)
528 struct GNUNET_ATS_SchedulingHandle *sh;
530 sh = GNUNET_malloc (sizeof (struct GNUNET_ATS_SchedulingHandle));
532 sh->suggest_cb = suggest_cb;
533 sh->suggest_cb_cls = suggest_cb_cls;
534 GNUNET_array_grow (sh->session_array, sh->session_array_size, 4);
541 * Client is done with ATS scheduling, release resources.
543 * @param sh handle to release
546 GNUNET_ATS_scheduling_done (struct GNUNET_ATS_SchedulingHandle *sh)
548 struct PendingMessage *p;
550 while (NULL != (p = sh->pending_head))
552 GNUNET_CONTAINER_DLL_remove (sh->pending_head, sh->pending_tail, p);
555 if (NULL != sh->client)
557 GNUNET_CLIENT_disconnect (sh->client, GNUNET_NO);
560 if (GNUNET_SCHEDULER_NO_TASK != sh->task)
562 GNUNET_SCHEDULER_cancel (sh->task);
563 sh->task = GNUNET_SCHEDULER_NO_TASK;
565 GNUNET_array_grow (sh->session_array, sh->session_array_size, 0);
571 * We would like to establish a new connection with a peer. ATS
572 * should suggest a good address to begin with.
575 * @param peer identity of the peer we need an address for
578 GNUNET_ATS_suggest_address (struct GNUNET_ATS_SchedulingHandle *sh,
579 const struct GNUNET_PeerIdentity *peer)
581 struct PendingMessage *p;
582 struct RequestAddressMessage *m;
584 p = GNUNET_malloc (sizeof (struct PendingMessage) +
585 sizeof (struct RequestAddressMessage));
586 p->size = sizeof (struct RequestAddressMessage);
587 p->is_init = GNUNET_NO;
588 m = (struct RequestAddressMessage *) &p[1];
589 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_REQUEST_ADDRESS);
590 m->header.size = htons (sizeof (struct RequestAddressMessage));
591 m->reserved = htonl (0);
593 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
599 * We have updated performance statistics for a given address. Note
600 * that this function can be called for addresses that are currently
601 * in use as well as addresses that are valid but not actively in use.
602 * Furthermore, the peer may not even be connected to us right now (in
603 * which case the call may be ignored or the information may be stored
604 * for later use). Update bandwidth assignments.
607 * @param peer identity of the new peer
608 * @param plugin_name name of the transport plugin
609 * @param plugin_addr address (if available)
610 * @param plugin_addr_len number of bytes in plugin_addr
611 * @param session session handle (if available)
612 * @param ats performance data for the address
613 * @param ats_count number of performance records in 'ats'
616 GNUNET_ATS_address_update (struct GNUNET_ATS_SchedulingHandle *sh,
617 const struct GNUNET_PeerIdentity *peer,
618 const char *plugin_name, const void *plugin_addr,
619 size_t plugin_addr_len, struct Session *session,
620 const struct GNUNET_ATS_Information *ats,
623 struct PendingMessage *p;
624 struct AddressUpdateMessage *m;
625 struct GNUNET_ATS_Information *am;
630 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
632 sizeof (struct AddressUpdateMessage) + plugin_addr_len +
633 ats_count * sizeof (struct GNUNET_ATS_Information) + namelen;
634 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
635 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
636 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
638 GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information)))
643 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
645 p->is_init = GNUNET_NO;
646 m = (struct AddressUpdateMessage *) &p[1];
647 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_UPDATE);
648 m->header.size = htons (msize);
649 m->ats_count = htonl (ats_count);
651 m->address_length = htons (plugin_addr_len);
652 m->plugin_name_length = htons (namelen);
653 m->session_id = htonl (get_session_id (sh, session, peer));
654 am = (struct GNUNET_ATS_Information *) &m[1];
655 memcpy (am, ats, ats_count * sizeof (struct GNUNET_ATS_Information));
656 pm = (char *) &am[ats_count];
657 memcpy (pm, plugin_addr, plugin_addr_len);
658 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
659 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
665 * An address is now in use or not used any more.
668 * @param peer identity of the peer
669 * @param plugin_name name of the transport plugin
670 * @param plugin_addr address (if available)
671 * @param plugin_addr_len number of bytes in plugin_addr
672 * @param session session handle
673 * @param in_use GNUNET_YES if this address is now used, GNUNET_NO
674 * if address is not used any more
677 GNUNET_ATS_address_in_use (struct GNUNET_ATS_SchedulingHandle *sh,
678 const struct GNUNET_PeerIdentity *peer,
679 const char *plugin_name, const void *plugin_addr,
680 size_t plugin_addr_len, struct Session *session,
683 struct PendingMessage *p;
684 struct AddressUseMessage *m;
689 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
690 msize = sizeof (struct AddressUseMessage) + plugin_addr_len + namelen;
691 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
692 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
693 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
698 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
700 p->is_init = GNUNET_NO;
701 m = (struct AddressUseMessage *) &p[1];
702 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_IN_USE);
703 m->header.size = htons (msize);
705 m->in_use = htons (in_use);
706 m->address_length = htons (plugin_addr_len);
707 m->plugin_name_length = htons (namelen);
708 m->session_id = htonl (get_session_id (sh, session, peer));
710 memcpy (pm, plugin_addr, plugin_addr_len);
711 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
712 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
718 * A session got destroyed, stop including it as a valid address.
721 * @param peer identity of the peer
722 * @param plugin_name name of the transport plugin
723 * @param plugin_addr address (if available)
724 * @param plugin_addr_len number of bytes in plugin_addr
725 * @param session session handle that is no longer valid
728 GNUNET_ATS_address_destroyed (struct GNUNET_ATS_SchedulingHandle *sh,
729 const struct GNUNET_PeerIdentity *peer,
730 const char *plugin_name, const void *plugin_addr,
731 size_t plugin_addr_len, struct Session *session)
733 struct PendingMessage *p;
734 struct AddressDestroyedMessage *m;
740 namelen = (plugin_name == NULL) ? 0 : strlen (plugin_name) + 1;
741 msize = sizeof (struct AddressDestroyedMessage) + plugin_addr_len + namelen;
742 if ((msize >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
743 (plugin_addr_len >= GNUNET_SERVER_MAX_MESSAGE_SIZE) ||
744 (namelen >= GNUNET_SERVER_MAX_MESSAGE_SIZE))
749 p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
751 p->is_init = GNUNET_NO;
752 m = (struct AddressDestroyedMessage *) &p[1];
753 m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_ADDRESS_DESTROYED);
754 m->header.size = htons (msize);
755 m->reserved = htonl (0);
757 m->address_length = htons (plugin_addr_len);
758 m->plugin_name_length = htons (namelen);
759 m->session_id = htonl (session_id = get_session_id (sh, session, peer));
761 memcpy (pm, plugin_addr, plugin_addr_len);
762 memcpy (&pm[plugin_addr_len], plugin_name, namelen);
763 GNUNET_CONTAINER_DLL_insert_tail (sh->pending_head, sh->pending_tail, p);
765 remove_session (sh, session_id, peer);
768 /* end of ats_api_scheduling.c */