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3 (C) 2001, 2002, 2004, 2005, 2007, 2009 Christian Grothoff (and other contributing authors)
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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;
96 struct GNUNET_SCHEDULER_Handle *sched;
99 * Connection to the service.
101 struct GNUNET_CLIENT_Connection *client;
104 * Head of transmission queue.
106 struct TransmissionQueueEntry *tq_head;
109 * Tail of transmission queue.
111 struct TransmissionQueueEntry *tq_tail;
114 * Handle for the current transmission request, or NULL if none is pending.
116 struct GNUNET_CLIENT_TransmitHandle *th;
119 * Set to GNUNET_YES if we are currently receiving replies from the
128 * Connect to the peerinfo service.
130 * @param sched scheduler to use
131 * @param cfg configuration to use
132 * @return NULL on error (configuration related, actual connection
133 * etablishment may happen asynchronously).
135 struct GNUNET_PEERINFO_Handle *
136 GNUNET_PEERINFO_connect (struct GNUNET_SCHEDULER_Handle *sched,
137 const struct GNUNET_CONFIGURATION_Handle *cfg)
139 struct GNUNET_CLIENT_Connection *client;
140 struct GNUNET_PEERINFO_Handle *ret;
142 client = GNUNET_CLIENT_connect (sched, "peerinfo", cfg);
145 ret = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_Handle));
146 ret->client = client;
154 * Disconnect from the peerinfo service. Note that all iterators must
155 * have completed or have been cancelled by the time this function is
156 * called (otherwise, calling this function is a serious error).
157 * Furthermore, if 'GNUNET_PEERINFO_add_peer' operations are still
158 * pending, they will be cancelled silently on disconnect.
160 * @param h handle to disconnect
163 GNUNET_PEERINFO_disconnect (struct GNUNET_PEERINFO_Handle *h)
165 struct TransmissionQueueEntry *tqe;
167 while (NULL != (tqe = h->tq_head))
169 GNUNET_CONTAINER_DLL_remove (h->tq_head,
172 if (tqe->cont != NULL)
173 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
176 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
182 * Check if we have a request pending in the transmission queue and are
183 * able to transmit it right now. If so, schedule transmission.
185 * @param h handle to the service
188 trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
192 * Close the existing connection to PEERINFO and reconnect.
194 * @param h handle to the service
197 reconnect (struct GNUNET_PEERINFO_Handle *h)
199 GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR);
200 h->client = GNUNET_CLIENT_connect (h->sched, "peerinfo", h->cfg);
201 GNUNET_assert (h->client != NULL);
206 * Transmit the request at the head of the transmission queue
207 * and trigger continuation (if any).
209 * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue)
210 * @param size size of the buffer (0 on error)
211 * @param buf where to copy the message
212 * @return number of bytes copied to buf
215 do_transmit (void *cls, size_t size, void *buf)
217 struct GNUNET_PEERINFO_Handle *h = cls;
218 struct TransmissionQueueEntry *tqe = h->tq_head;
225 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
227 ("Failed to transmit message of type %u to `%s' service.\n"),
228 ntohs (msg->type), "peerinfo");
230 GNUNET_CONTAINER_DLL_remove (h->tq_head,
234 trigger_transmit (h);
235 if (tqe->cont != NULL)
236 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
241 GNUNET_assert (size >= ret);
242 memcpy (buf, &tqe[1], ret);
243 GNUNET_CONTAINER_DLL_remove (h->tq_head,
246 if (tqe->cont != NULL)
247 tqe->cont (tqe->cont_cls, GNUNET_OK);
249 trigger_transmit (h);
256 * Check if we have a request pending in the transmission queue and are
257 * able to transmit it right now. If so, schedule transmission.
259 * @param h handle to the service
262 trigger_transmit (struct GNUNET_PEERINFO_Handle *h)
264 struct TransmissionQueueEntry *tqe;
266 /* FIXME: need to handle case where we are still *receiving* (and then
267 do nothing here as well!) */
268 if (NULL == (tqe = h->tq_head))
272 if (h->in_receive == GNUNET_YES)
274 h->th = GNUNET_CLIENT_notify_transmit_ready (h->client,
276 GNUNET_TIME_absolute_get_remaining (tqe->timeout),
283 * Add a host to the persistent list. This method operates in
284 * semi-reliable mode: if the transmission is not completed by
285 * the time 'GNUNET_PEERINFO_disconnect' is called, it will be
286 * aborted. Furthermore, if a second HELLO is added for the
287 * same peer before the first one was transmitted, PEERINFO may
288 * merge the two HELLOs prior to transmission to the service.
290 * @param h handle to the peerinfo service
291 * @param hello the verified (!) HELLO message
294 GNUNET_PEERINFO_add_peer (struct GNUNET_PEERINFO_Handle *h,
295 const struct GNUNET_HELLO_Message *hello)
297 uint16_t hs = GNUNET_HELLO_size (hello);
298 struct TransmissionQueueEntry *tqe;
301 struct GNUNET_PeerIdentity peer;
302 GNUNET_assert (GNUNET_OK == GNUNET_HELLO_get_id (hello, &peer));
303 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
304 "Adding peer `%s' to PEERINFO database (%u bytes of `%s')\n",
309 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) + hs);
311 tqe->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
312 memcpy (&tqe[1], hello, hs);
313 GNUNET_CONTAINER_DLL_insert_after (h->tq_head,
317 trigger_transmit (h);
322 * Context for an iteration request.
324 struct GNUNET_PEERINFO_IteratorContext
327 * Handle to the PEERINFO service.
329 struct GNUNET_PEERINFO_Handle *h;
332 * Function to call with the results.
334 GNUNET_PEERINFO_Processor callback;
337 * Closure for 'callback'.
342 * Our entry in the transmission queue.
344 struct TransmissionQueueEntry *tqe;
347 * Task responsible for timeout.
349 GNUNET_SCHEDULER_TaskIdentifier timeout_task;
352 * Timeout for the operation.
354 struct GNUNET_TIME_Absolute timeout;
357 * Are we now receiving?
364 * Type of a function to call when we receive a message
368 * @param msg message received, NULL on timeout or fatal error
371 peerinfo_handler (void *cls, const struct GNUNET_MessageHeader *msg)
373 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
374 const struct InfoMessage *im;
375 const struct GNUNET_HELLO_Message *hello;
378 ic->h->in_receive = GNUNET_NO;
381 GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
382 _("Failed to receive response from `%s' service.\n"),
385 trigger_transmit (ic->h);
386 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
387 GNUNET_SCHEDULER_cancel (ic->h->sched,
389 if (ic->callback != NULL)
390 ic->callback (ic->callback_cls, NULL, NULL, 1);
394 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
397 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
398 "Received end of list of peers from peerinfo database\n");
400 trigger_transmit (ic->h);
401 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
402 GNUNET_SCHEDULER_cancel (ic->h->sched,
404 if (ic->callback != NULL)
405 ic->callback (ic->callback_cls, NULL, NULL, 0);
409 ms = ntohs (msg->size);
410 if ((ms < sizeof (struct InfoMessage)) ||
411 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
415 trigger_transmit (ic->h);
416 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
417 GNUNET_SCHEDULER_cancel (ic->h->sched,
419 if (ic->callback != NULL)
420 ic->callback (ic->callback_cls, NULL, NULL, 2);
424 im = (const struct InfoMessage *) msg;
426 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
428 hello = (const struct GNUNET_HELLO_Message *) &im[1];
429 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
433 trigger_transmit (ic->h);
434 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
435 GNUNET_SCHEDULER_cancel (ic->h->sched,
437 if (ic->callback != NULL)
438 ic->callback (ic->callback_cls, NULL, NULL, 2);
444 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
445 "Received %u bytes of `%s' information about peer `%s' from PEERINFO database\n",
446 (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello),
448 GNUNET_i2s (&im->peer));
450 ic->h->in_receive = GNUNET_YES;
451 if (ic->callback != NULL)
452 ic->callback (ic->callback_cls, &im->peer, hello, ntohl (im->trust));
453 GNUNET_CLIENT_receive (ic->h->client,
456 GNUNET_TIME_absolute_get_remaining (ic->timeout));
461 * We've transmitted the iteration request. Now get ready to process
462 * the results (or handle transmission error).
464 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
465 * @param transmit_success GNUNET_OK if transmission worked
468 iterator_start_receive (void *cls,
469 int transmit_success)
471 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
473 if (GNUNET_OK != transmit_success)
475 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
477 GNUNET_SCHEDULER_cancel (ic->h->sched,
479 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
482 trigger_transmit (ic->h);
483 ic->callback (ic->callback_cls, NULL, NULL, 2);
487 ic->h->in_receive = GNUNET_YES;
488 ic->in_receive = GNUNET_YES;
490 GNUNET_CLIENT_receive (ic->h->client,
493 GNUNET_TIME_absolute_get_remaining (ic->timeout));
498 * Peerinfo iteration request has timed out.
500 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
501 * @param tc scheduler context
504 signal_timeout (void *cls,
505 const struct GNUNET_SCHEDULER_TaskContext *tc)
507 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
509 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
510 if (! ic->in_receive)
511 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head,
514 ic->callback (ic->callback_cls, NULL, NULL, 1);
518 GNUNET_free (ic->tqe);
524 * Call a method for each known matching host and change its trust
525 * value. The callback method will be invoked once for each matching
526 * host and then finally once with a NULL pointer. After that final
527 * invocation, the iterator context must no longer be used.
529 * Note that the last call can be triggered by timeout or by simply
530 * being done; however, the trust argument will be set to zero if we
531 * are done, 1 if we timed out and 2 for fatal error.
533 * Instead of calling this function with 'peer == NULL' and 'trust ==
534 * 0', it is often better to use 'GNUNET_PEERINFO_notify'.
536 * @param h handle to the peerinfo service
537 * @param peer restrict iteration to this peer only (can be NULL)
538 * @param trust_delta how much to change the trust in all matching peers
539 * @param timeout how long to wait until timing out
540 * @param callback the method to call for each peer
541 * @param callback_cls closure for callback
542 * @return NULL on error (in this case, 'callback' is never called!),
543 * otherwise an iterator context
545 struct GNUNET_PEERINFO_IteratorContext *
546 GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
547 const struct GNUNET_PeerIdentity *peer,
549 struct GNUNET_TIME_Relative timeout,
550 GNUNET_PEERINFO_Processor callback,
553 struct ListAllPeersMessage *lapm;
554 struct ListPeerMessage *lpm;
555 struct GNUNET_PEERINFO_IteratorContext *ic;
556 struct TransmissionQueueEntry *tqe;
559 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
560 "Requesting list of peers from peerinfo database\n");
564 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
565 sizeof (struct ListAllPeersMessage));
566 tqe->size = sizeof (struct ListAllPeersMessage);
567 lapm = (struct ListAllPeersMessage *) &tqe[1];
568 lapm->header.size = htons (sizeof (struct ListAllPeersMessage));
569 lapm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
570 lapm->trust_change = htonl (trust_delta);
574 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
575 sizeof (struct ListPeerMessage));
576 tqe->size = sizeof (struct ListPeerMessage);
577 lpm = (struct ListPeerMessage *) &tqe[1];
578 lpm->header.size = htons (sizeof (struct ListPeerMessage));
579 lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
580 lpm->trust_change = htonl (trust_delta);
581 memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
583 ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext));
586 ic->callback = callback;
587 ic->callback_cls = callback_cls;
588 ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
589 ic->timeout_task = GNUNET_SCHEDULER_add_delayed (h->sched,
593 tqe->timeout = ic->timeout;
594 tqe->cont = &iterator_start_receive;
596 tqe->timeout = ic->timeout;
597 GNUNET_CONTAINER_DLL_insert_after (h->tq_head,
601 trigger_transmit (h);
608 * Cancel an iteration over peer information.
610 * @param ic context of the iterator to cancel
613 GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
615 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
617 GNUNET_SCHEDULER_cancel (ic->h->sched,
619 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
623 return; /* need to finish processing */
624 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head,
627 GNUNET_free (ic->tqe);
632 /* end of peerinfo_api.c */