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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);
178 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
181 GNUNET_CLIENT_disconnect (h->client, GNUNET_NO);
187 * Check if we have a request pending in the transmission queue and are
188 * able to transmit it right now. If so, schedule transmission.
190 * @param h handle to the service
193 trigger_transmit (struct GNUNET_PEERINFO_Handle *h);
197 * Close the existing connection to PEERINFO and reconnect.
199 * @param h handle to the service
202 reconnect (struct GNUNET_PEERINFO_Handle *h)
204 GNUNET_CLIENT_disconnect (h->client, GNUNET_SYSERR);
205 h->client = GNUNET_CLIENT_connect (h->sched, "peerinfo", h->cfg);
206 GNUNET_assert (h->client != NULL);
211 * Transmit the request at the head of the transmission queue
212 * and trigger continuation (if any).
214 * @param cls the 'struct GNUNET_PEERINFO_Handle' (with the queue)
215 * @param size size of the buffer (0 on error)
216 * @param buf where to copy the message
217 * @return number of bytes copied to buf
220 do_transmit (void *cls, size_t size, void *buf)
222 struct GNUNET_PEERINFO_Handle *h = cls;
223 struct TransmissionQueueEntry *tqe = h->tq_head;
230 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
232 ("Failed to transmit message of type %u to `%s' service.\n"),
233 ntohs (msg->type), "peerinfo");
235 GNUNET_CONTAINER_DLL_remove (h->tq_head,
239 trigger_transmit (h);
240 if (tqe->cont != NULL)
241 tqe->cont (tqe->cont_cls, GNUNET_SYSERR);
246 GNUNET_assert (size >= ret);
247 memcpy (buf, &tqe[1], ret);
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_WARNING,
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->h->sched,
392 if (ic->callback != NULL)
393 ic->callback (ic->callback_cls, NULL, NULL, 1);
397 if (ntohs (msg->type) == GNUNET_MESSAGE_TYPE_PEERINFO_INFO_END)
400 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
401 "Received end of list of peers from peerinfo database\n");
403 trigger_transmit (ic->h);
404 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
405 GNUNET_SCHEDULER_cancel (ic->h->sched,
407 if (ic->callback != NULL)
408 ic->callback (ic->callback_cls, NULL, NULL, 0);
412 ms = ntohs (msg->size);
413 if ((ms < sizeof (struct InfoMessage)) ||
414 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_PEERINFO_INFO))
418 trigger_transmit (ic->h);
419 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
420 GNUNET_SCHEDULER_cancel (ic->h->sched,
422 if (ic->callback != NULL)
423 ic->callback (ic->callback_cls, NULL, NULL, 2);
427 im = (const struct InfoMessage *) msg;
429 if (ms > sizeof (struct InfoMessage) + sizeof (struct GNUNET_MessageHeader))
431 hello = (const struct GNUNET_HELLO_Message *) &im[1];
432 if (ms != sizeof (struct InfoMessage) + GNUNET_HELLO_size (hello))
436 trigger_transmit (ic->h);
437 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
438 GNUNET_SCHEDULER_cancel (ic->h->sched,
440 if (ic->callback != NULL)
441 ic->callback (ic->callback_cls, NULL, NULL, 2);
447 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
448 "Received %u bytes of `%s' information about peer `%s' from PEERINFO database\n",
449 (hello == NULL) ? 0 : (unsigned int) GNUNET_HELLO_size (hello),
451 GNUNET_i2s (&im->peer));
453 ic->h->in_receive = GNUNET_YES;
454 if (ic->callback != NULL)
455 ic->callback (ic->callback_cls, &im->peer, hello, ntohl (im->trust));
456 GNUNET_CLIENT_receive (ic->h->client,
459 GNUNET_TIME_absolute_get_remaining (ic->timeout));
464 * We've transmitted the iteration request. Now get ready to process
465 * the results (or handle transmission error).
467 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext'
468 * @param transmit_success GNUNET_OK if transmission worked
471 iterator_start_receive (void *cls,
472 int transmit_success)
474 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
476 if (GNUNET_OK != transmit_success)
478 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
480 GNUNET_SCHEDULER_cancel (ic->h->sched,
482 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
485 trigger_transmit (ic->h);
486 ic->callback (ic->callback_cls, NULL, NULL, 1);
490 ic->h->in_receive = GNUNET_YES;
491 ic->in_receive = GNUNET_YES;
493 GNUNET_CLIENT_receive (ic->h->client,
496 GNUNET_TIME_absolute_get_remaining (ic->timeout));
501 * Peerinfo iteration request has timed out.
503 * @param cls the 'struct GNUNET_PEERINFO_IteratorContext*'
504 * @param tc scheduler context
507 signal_timeout (void *cls,
508 const struct GNUNET_SCHEDULER_TaskContext *tc)
510 struct GNUNET_PEERINFO_IteratorContext *ic = cls;
512 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
513 if (! ic->in_receive)
514 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head,
517 ic->callback (ic->callback_cls, NULL, NULL, 1);
521 GNUNET_free (ic->tqe);
527 * Call a method for each known matching host and change its trust
528 * value. The callback method will be invoked once for each matching
529 * host and then finally once with a NULL pointer. After that final
530 * invocation, the iterator context must no longer be used.
532 * Note that the last call can be triggered by timeout or by simply
533 * being done; however, the trust argument will be set to zero if we
534 * are done, 1 if we timed out and 2 for fatal error.
536 * Instead of calling this function with 'peer == NULL' and 'trust ==
537 * 0', it is often better to use 'GNUNET_PEERINFO_notify'.
539 * @param h handle to the peerinfo service
540 * @param peer restrict iteration to this peer only (can be NULL)
541 * @param trust_delta how much to change the trust in all matching peers
542 * @param timeout how long to wait until timing out
543 * @param callback the method to call for each peer
544 * @param callback_cls closure for callback
545 * @return NULL on error (in this case, 'callback' is never called!),
546 * otherwise an iterator context
548 struct GNUNET_PEERINFO_IteratorContext *
549 GNUNET_PEERINFO_iterate (struct GNUNET_PEERINFO_Handle *h,
550 const struct GNUNET_PeerIdentity *peer,
552 struct GNUNET_TIME_Relative timeout,
553 GNUNET_PEERINFO_Processor callback,
556 struct ListAllPeersMessage *lapm;
557 struct ListPeerMessage *lpm;
558 struct GNUNET_PEERINFO_IteratorContext *ic;
559 struct TransmissionQueueEntry *tqe;
562 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
563 "Requesting list of peers from peerinfo database\n");
567 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
568 sizeof (struct ListAllPeersMessage));
569 tqe->size = sizeof (struct ListAllPeersMessage);
570 lapm = (struct ListAllPeersMessage *) &tqe[1];
571 lapm->header.size = htons (sizeof (struct ListAllPeersMessage));
572 lapm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET_ALL);
573 lapm->trust_change = htonl (trust_delta);
577 tqe = GNUNET_malloc (sizeof (struct TransmissionQueueEntry) +
578 sizeof (struct ListPeerMessage));
579 tqe->size = sizeof (struct ListPeerMessage);
580 lpm = (struct ListPeerMessage *) &tqe[1];
581 lpm->header.size = htons (sizeof (struct ListPeerMessage));
582 lpm->header.type = htons (GNUNET_MESSAGE_TYPE_PEERINFO_GET);
583 lpm->trust_change = htonl (trust_delta);
584 memcpy (&lpm->peer, peer, sizeof (struct GNUNET_PeerIdentity));
586 ic = GNUNET_malloc (sizeof (struct GNUNET_PEERINFO_IteratorContext));
589 ic->callback = callback;
590 ic->callback_cls = callback_cls;
591 ic->timeout = GNUNET_TIME_relative_to_absolute (timeout);
592 ic->timeout_task = GNUNET_SCHEDULER_add_delayed (h->sched,
596 tqe->timeout = ic->timeout;
597 tqe->cont = &iterator_start_receive;
599 tqe->timeout = ic->timeout;
600 GNUNET_CONTAINER_DLL_insert_after (h->tq_head,
604 trigger_transmit (h);
611 * Cancel an iteration over peer information.
613 * @param ic context of the iterator to cancel
616 GNUNET_PEERINFO_iterate_cancel (struct GNUNET_PEERINFO_IteratorContext *ic)
618 if (ic->timeout_task != GNUNET_SCHEDULER_NO_TASK)
620 GNUNET_SCHEDULER_cancel (ic->h->sched,
622 ic->timeout_task = GNUNET_SCHEDULER_NO_TASK;
626 return; /* need to finish processing */
627 GNUNET_CONTAINER_DLL_remove (ic->h->tq_head,
630 GNUNET_free (ic->tqe);
635 /* end of peerinfo_api.c */