2 This file is part of GNUnet.
3 (C) 2001, 2002, 2004, 2005, 2007, 2009, 2010 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file peerinfo/peerinfo_api.c
23 * @brief API to access peerinfo service
24 * @author Christian Grothoff
27 #include "gnunet_client_lib.h"
28 #include "gnunet_container_lib.h"
29 #include "gnunet_peerinfo_service.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_time_lib.h"
35 * Function to call after transmission has succeeded.
38 * @param success GNUNET_OK if transmission worked, GNUNET_SYSERR on error
40 typedef void (*TransmissionContinuation)(void *cls,
45 * Entry in the transmission queue to PEERINFO service.
47 struct TransmissionQueueEntry
50 * This is a linked list.
52 struct TransmissionQueueEntry *next;
55 * This is a linked list.
57 struct TransmissionQueueEntry *prev;
60 * Function to call after request has been transmitted, or NULL (in which
61 * case we must consider sending the next entry immediately).
63 TransmissionContinuation cont;
71 * Timeout for the operation.
73 struct GNUNET_TIME_Absolute timeout;
76 * Number of bytes of the request message (follows after this struct).
84 * Handle to the peerinfo service.
86 struct GNUNET_PEERINFO_Handle
91 const struct GNUNET_CONFIGURATION_Handle *cfg;
94 * Connection to the service.
96 struct GNUNET_CLIENT_Connection *client;
99 * Head of transmission queue.
101 struct TransmissionQueueEntry *tq_head;
104 * Tail of transmission queue.
106 struct TransmissionQueueEntry *tq_tail;
109 * Handle for the current transmission request, or NULL if none is pending.
111 struct GNUNET_CLIENT_TransmitHandle *th;
114 * Set to GNUNET_YES if we are currently receiving replies from the
123 * Connect to the peerinfo service.
125 * @param cfg configuration to use
126 * @return NULL on error (configuration related, actual connection
127 * establishment may happen asynchronously).
129 struct GNUNET_PEERINFO_Handle *
130 GNUNET_PEERINFO_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
132 struct GNUNET_CLIENT_Connection *client;
133 struct GNUNET_PEERINFO_Handle *ret;
135 client = GNUNET_CLIENT_connect ("peerinfo", cfg);
138 ret = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle));
139 ret->client = client;
146 * Disconnect from the peerinfo service. Note that all iterators must
147 * have completed or have been cancelled by the time this function is
148 * called (otherwise, calling this function is a serious error).
149 * Furthermore, if 'GNUNET_PEERINFO_add_peer' operations are still
150 * pending, they will be cancelled silently on disconnect.
152 * @param h handle to disconnect
155 GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h)
157 struct TransmissionQueueEntry *tqe;
159 while (NULL != (tqe = h->tq_head))
161 GNUNET_CONTAINER_DLL_remove (h->tq_head,
164 if (tqe->cont != NULL)
165 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
170 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
173 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
179 * Check if we have a request pending in the transmission queue and are
180 * able to transmit it right now. If so, schedule transmission.
182 * @param h handle to the service
185 trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
189 * Close the existing connection to PEERINFO and reconnect.
191 * @param h handle to the service
194 reconnect (struct GNUNET_PEERINFO_Handle *h)
196 GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR);
198 h->client = GNUNET_CLIENT_connect ("peerinfo", h->cfg);
199 GNUNET_assert (h->client != NULL);
204 * Transmit the request at the head of the transmission queue
205 * and trigger continuation (if any).
207 * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue)
208 * @param size size of the buffer (0 on error)
209 * @param buf where to copy the message
210 * @return number of bytes copied to buf
213 do_transmit (void *cls, size_t size, void *buf)
215 struct GNUNET_PEERINFO_Handle *h = cls;
216 struct TransmissionQueueEntry *tqe = h->tq_head;
222 GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
223 _("Failed to transmit message to `%s' service.\n"),
226 GNUNET_CONTAINER_DLL_remove (h->tq_head,
230 trigger_transmit (h);
233 if (tqe->cont != NULL)
234 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
240 GNUNET_assert (size >= ret);
241 memcpy (buf, &tqe[1], ret);
243 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
244 "Transmitting request of size %u to `%s' service.\n",
248 GNUNET_CONTAINER_DLL_remove (h->tq_head,
251 if (tqe->cont != NULL)
252 tqe->cont (tqe->cont_cls, GNUNET_OK);
254 trigger_transmit (h);
261 * Check if we have a request pending in the transmission queue and are
262 * able to transmit it right now. If so, schedule transmission.
264 * @param h handle to the service
267 trigger_transmit (struct GNUNET_PEERINFO_Handle *h)
269 struct TransmissionQueueEntry *tqe;
271 if (NULL == (tqe = h->tq_head))
275 if (h->in_receive == GNUNET_YES)
277 h->th = GNUNET_CLIENT_notify_transmit_ready (h->client,
279 GNUNET_TIME_absolute_get_remaining (tqe->timeout),
286 * Add a host to the persistent list. This method operates in
287 * semi-reliable mode: if the transmission is not completed by
288 * the time 'GNUNET_PEERINFO_disconnect' is called, it will be
289 * aborted. Furthermore, if a second HELLO is added for the
290 * same peer before the first one was transmitted, PEERINFO may
291 * merge the two HELLOs prior to transmission to the service.
293 * @param h handle to the peerinfo service
294 * @param hello the verified (!) HELLO message
297 GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
298 const struct GNUNET_HELLO_Message *hello)
300 uint16_t hs = GNUNET_HELLO_size (hello);
301 struct TransmissionQueueEntry *tqe;
304 struct GNUNET_PeerIdentity peer;
305 GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer));
306 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
307 "Adding peer `%s' to PEERINFO database (%u bytes of `%s')\n",
312 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + hs);
314 tqe->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
315 memcpy (&tqe[1], hello, hs);
316 GNUNET_CONTAINER_DLL_insert_after (h->tq_head,
320 trigger_transmit (h);
325 * Context for an iteration request.
327 struct GNUNET_PEERINFO_IteratorContext
330 * Handle to the PEERINFO service.
332 struct GNUNET_PEERINFO_Handle *h;
335 * Function to call with the results.
337 GNUNET_PEERINFO_Processor callback;
340 * Closure for 'callback'.
345 * Our entry in the transmission queue.
347 struct TransmissionQueueEntry *tqe;
350 * Task responsible for timeout.
352 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
355 * Timeout for the operation.
357 struct GNUNET_TIME_Absolute timeout;
360 * Are we now receiving?
367 * Type of a function to call when we receive a message
371 * @param msg message received, NULL on timeout or fatal error
374 peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg)
376 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
377 const struct InfoMessage *im;
378 const struct GNUNET_HELLO_Message *hello;
381 ic->h->in_receive = GNUNET_NO;
384 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
385 _("Failed to receive response from `%s' service.\n"),
388 trigger_transmit (ic->h);
389 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
390 GNUNET_SCHEDULER_cancel (ic->timeout_task);
391 if (ic->callback != NULL)
392 ic->callback (ic->callback_cls, NULL, NULL);
396 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
399 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
400 "Received end of list of peers from `%s' service\n",
403 trigger_transmit (ic->h);
404 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
405 GNUNET_SCHEDULER_cancel (ic->timeout_task);
406 if (ic->callback != NULL)
407 ic->callback (ic->callback_cls, NULL, NULL);
411 ms = ntohs (msg->size);
412 if ((ms < sizeof (struct InfoMessage)) ||
413 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
417 trigger_transmit (ic->h);
418 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
419 GNUNET_SCHEDULER_cancel (ic->timeout_task);
420 if (ic->callback != NULL)
421 ic->callback (ic->callback_cls, NULL, NULL);
425 im = (const struct InfoMessage *) msg;
426 GNUNET_break (0 == ntohl (im->reserved));
428 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
430 hello = (const struct GNUNET_HELLO_Message *) &im[1];
431 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
435 trigger_transmit (ic->h);
436 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
437 GNUNET_SCHEDULER_cancel (ic->timeout_task);
438 if (ic->callback != NULL)
439 ic->callback (ic->callback_cls, NULL, NULL);
445 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
446 "Received %u bytes of `%s' information about peer `%s' from `%s' service\n",
447 (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello),
449 GNUNET_i2s (&im->peer),
452 ic->h->in_receive = GNUNET_YES;
453 if (ic->callback != NULL)
454 ic->callback (ic->callback_cls, &im->peer, hello);
455 GNUNET_CLIENT_receive (ic->h->client,
458 GNUNET_TIME_absolute_get_remaining (ic->timeout));
463 * We've transmitted the iteration request. Now get ready to process
464 * the results (or handle transmission error).
466 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
467 * @param transmit_success GNUNET_OK if transmission worked
470 iterator_start_receive (void *cls,
471 int transmit_success)
473 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
475 if (GNUNET_OK != transmit_success)
477 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
478 _("Failed to transmit iteration request to `%s' service (%d).\n"),
481 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
483 GNUNET_SCHEDULER_cancel (ic->timeout_task);
484 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
487 trigger_transmit (ic->h);
488 if (ic->callback != NULL)
489 ic->callback (ic->callback_cls, NULL, NULL);
494 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
495 "Waiting for response from `%s' service.\n",
498 ic->h->in_receive = GNUNET_YES;
499 ic->in_receive = GNUNET_YES;
501 GNUNET_CLIENT_receive (ic->h->client,
504 GNUNET_TIME_absolute_get_remaining (ic->timeout));
509 * Peerinfo iteration request has timed out.
511 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
512 * @param tc scheduler context
515 signal_timeout (void *cls,
516 const struct GNUNET_SCHEDULER_TaskContext *tc)
518 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
520 GNUNET_log (GNUNET_ERROR_TYPE_WARNING | GNUNET_ERROR_TYPE_BULK,
521 _("Timeout transmitting iteration request to `%s' service.\n"),
523 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
524 if (! ic->in_receive)
525 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head,
529 ic->callback (ic->callback_cls, NULL, NULL);
531 GNUNET_free_non_null (ic->tqe);
537 * Call a method for each known matching host and change its trust
538 * value. The callback method will be invoked once for each matching
539 * host and then finally once with a NULL pointer. After that final
540 * invocation, the iterator context must no longer be used.
542 * Instead of calling this function with 'peer == NULL' it is often
543 * better to use 'GNUNET_PEERINFO_notify'.
545 * @param h handle to the peerinfo service
546 * @param peer restrict iteration to this peer only (can be NULL)
547 * @param timeout how long to wait until timing out
548 * @param callback the method to call for each peer
549 * @param callback_cls closure for callback
550 * @return NULL on error (in this case, 'callback' is never called!),
551 * otherwise an iterator context
553 struct GNUNET_PEERINFO_IteratorContext *
554 GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
555 const struct GNUNET_PeerIdentity *peer,
556 struct GNUNET_TIME_Relative timeout,
557 GNUNET_PEERINFO_Processor callback,
560 struct GNUNET_MessageHeader *lapm;
561 struct ListPeerMessage *lpm;
562 struct GNUNET_PEERINFO_IteratorContext *ic;
563 struct TransmissionQueueEntry *tqe;
568 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
569 "Requesting list of peers from PEERINFO service\n");
571 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
572 sizeof (struct GNUNET_MessageHeader));
573 tqe->size = sizeof (struct GNUNET_MessageHeader);
574 lapm = (struct GNUNET_MessageHeader *) &tqe[1];
575 lapm->size = htons (sizeof (struct GNUNET_MessageHeader));
576 lapm->type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
581 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
582 "Requesting information on peer `%4s' from PEERINFO service\n",
585 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
586 sizeof (struct ListPeerMessage));
587 tqe->size = sizeof (struct ListPeerMessage);
588 lpm = (struct ListPeerMessage *) &tqe[1];
589 lpm->header.size = htons (sizeof (struct ListPeerMessage));
590 lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
591 memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
593 ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext));
596 ic->callback = callback;
597 ic->callback_cls = callback_cls;
598 ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
599 ic->timeout_task = GNUNET_SCHEDULER_add_delayed (timeout,
602 tqe->timeout = ic->timeout;
603 tqe->cont = &iterator_start_receive;
605 tqe->timeout = ic->timeout;
606 GNUNET_CONTAINER_DLL_insert_after (h->tq_head,
610 trigger_transmit (h);
617 * Cancel an iteration over peer information.
619 * @param ic context of the iterator to cancel
622 GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
624 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
626 GNUNET_SCHEDULER_cancel (ic->timeout_task);
627 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
631 return; /* need to finish processing */
632 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head,
635 GNUNET_free (ic->tqe);
640 /* end of peerinfo_api.c */