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21 * @file fs/gnunet-service-fs_lc.c
22 * @brief API to handle 'local clients'
23 * @author Christian Grothoff
26 #include "gnunet-service-fs.h"
27 #include "gnunet-service-fs_lc.h"
28 #include "gnunet-service-fs_cp.h"
29 #include "gnunet-service-fs_pr.h"
33 * Doubly-linked list of requests we are performing
34 * on behalf of the same client.
40 * This is a doubly-linked list.
42 struct ClientRequest *next;
45 * This is a doubly-linked list.
47 struct ClientRequest *prev;
50 * Request this entry represents.
52 struct GSF_PendingRequest *pr;
55 * Client list this request belongs to.
57 struct GSF_LocalClient *lc;
60 * Task scheduled to destroy the request.
62 struct GNUNET_SCHEDULER_Task * kill_task;
68 * Replies to be transmitted to the client. The actual
69 * response message is allocated after this struct.
74 * This is a doubly-linked list.
76 struct ClientResponse *next;
79 * This is a doubly-linked list.
81 struct ClientResponse *prev;
84 * Client list entry this response belongs to.
86 struct GSF_LocalClient *lc;
89 * Number of bytes in the response.
98 struct GSF_LocalClient
102 * We keep clients in a DLL.
104 struct GSF_LocalClient *next;
107 * We keep clients in a DLL.
109 struct GSF_LocalClient *prev;
114 struct GNUNET_SERVER_Client *client;
117 * Head of list of requests performed on behalf
118 * of this client right now.
120 struct ClientRequest *cr_head;
123 * Tail of list of requests performed on behalf
124 * of this client right now.
126 struct ClientRequest *cr_tail;
129 * Head of linked list of responses.
131 struct ClientResponse *res_head;
134 * Tail of linked list of responses.
136 struct ClientResponse *res_tail;
139 * Context for sending replies.
141 struct GNUNET_SERVER_TransmitHandle *th;
147 * Head of linked list of our local clients.
149 static struct GSF_LocalClient *client_head;
152 * Head of linked list of our local clients.
154 static struct GSF_LocalClient *client_tail;
158 * Look up a local client record or create one if it
161 * @param client handle of the client
162 * @return handle to local client entry
164 struct GSF_LocalClient *
165 GSF_local_client_lookup_ (struct GNUNET_SERVER_Client *client)
167 struct GSF_LocalClient *pos;
170 while ((NULL != pos) && (pos->client != client))
174 pos = GNUNET_new (struct GSF_LocalClient);
175 pos->client = client;
176 GNUNET_CONTAINER_DLL_insert (client_head,
184 * Free the given client request.
186 * @param cls the client request to free
187 * @param tc task context
190 client_request_destroy (void *cls,
191 const struct GNUNET_SCHEDULER_TaskContext *tc)
193 struct ClientRequest *cr = cls;
194 struct GSF_LocalClient *lc;
196 cr->kill_task = NULL;
198 GNUNET_CONTAINER_DLL_remove (lc->cr_head,
201 GSF_pending_request_cancel_ (cr->pr,
203 GNUNET_STATISTICS_update (GSF_stats,
204 gettext_noop ("# client searches active"),
212 * Handle a reply to a pending request. Also called if a request
213 * expires (then with data == NULL). The handler may be called
214 * many times (depending on the request type), but will not be
215 * called during or after a call to #GSF_pending_request_cancel()
216 * and will also not be called anymore after a call signalling
219 * @param cls user-specified closure
220 * @param eval evaluation of the result
221 * @param pr handle to the original pending request
222 * @param reply_anonymity_level anonymity level for the reply, UINT32_MAX for "unknown"
223 * @param expiration when does @a data expire?
224 * @param last_transmission when was the last time we've tried to download this block? (FOREVER if unknown)
225 * @param type type of the block
226 * @param data response data, NULL on request expiration
227 * @param data_len number of bytes in @a data
230 client_response_handler (void *cls,
231 enum GNUNET_BLOCK_EvaluationResult eval,
232 struct GSF_PendingRequest *pr,
233 uint32_t reply_anonymity_level,
234 struct GNUNET_TIME_Absolute expiration,
235 struct GNUNET_TIME_Absolute last_transmission,
236 enum GNUNET_BLOCK_Type type,
240 struct ClientRequest *cr = cls;
241 struct GSF_LocalClient *lc;
242 struct ClientPutMessage *pm;
243 const struct GSF_PendingRequestData *prd;
248 /* local-only request, with no result, clean up. */
249 if (NULL == cr->kill_task)
250 cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy,
254 prd = GSF_pending_request_get_data_ (pr);
255 GNUNET_break (type != GNUNET_BLOCK_TYPE_ANY);
256 if ((prd->type != type) && (prd->type != GNUNET_BLOCK_TYPE_ANY))
261 GNUNET_STATISTICS_update (GSF_stats,
263 ("# replies received for local clients"), 1,
265 GNUNET_assert (pr == cr->pr);
267 msize = sizeof (struct ClientPutMessage) + data_len;
269 char buf[msize] GNUNET_ALIGN;
271 pm = (struct ClientPutMessage *) buf;
272 pm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_PUT);
273 pm->header.size = htons (msize);
274 pm->type = htonl (type);
275 pm->expiration = GNUNET_TIME_absolute_hton (expiration);
276 pm->last_transmission = GNUNET_TIME_absolute_hton (last_transmission);
277 pm->num_transmissions = htonl (prd->num_transmissions);
278 pm->respect_offered = htonl (prd->respect_offered);
279 memcpy (&pm[1], data, data_len);
280 GSF_local_client_transmit_ (lc, &pm->header);
282 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
283 "Queued reply to query `%s' for local client\n",
284 GNUNET_h2s (&prd->query), (unsigned int) prd->type);
285 if (GNUNET_BLOCK_EVALUATION_OK_LAST != eval)
287 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
288 "Evaluation %d - keeping query alive\n",
292 if (NULL == cr->kill_task)
293 cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy, cr);
298 * Handle START_SEARCH-message (search request from local client).
299 * Only responsible for creating the request entry itself and setting
300 * up reply callback and cancellation on client disconnect. Does NOT
301 * execute the actual request strategy (planning).
303 * @param client identification of the client
304 * @param message the actual message
305 * @param prptr where to store the pending request handle for the request
306 * @return #GNUNET_YES to start local processing,
307 * #GNUNET_NO to not (yet) start local processing,
308 * #GNUNET_SYSERR on error
311 GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
312 const struct GNUNET_MessageHeader *message,
313 struct GSF_PendingRequest **prptr)
315 static struct GNUNET_PeerIdentity all_zeros;
316 const struct SearchMessage *sm;
317 struct GSF_LocalClient *lc;
318 struct ClientRequest *cr;
319 struct GSF_PendingRequestData *prd;
322 enum GNUNET_BLOCK_Type type;
323 enum GSF_PendingRequestOptions options;
325 msize = ntohs (message->size);
326 if ((msize < sizeof (struct SearchMessage)) ||
327 (0 != (msize - sizeof (struct SearchMessage)) % sizeof (struct GNUNET_HashCode)))
331 return GNUNET_SYSERR;
333 GNUNET_STATISTICS_update (GSF_stats,
334 gettext_noop ("# client searches received"),
337 sc = (msize - sizeof (struct SearchMessage)) / sizeof (struct GNUNET_HashCode);
338 sm = (const struct SearchMessage *) message;
339 type = ntohl (sm->type);
340 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
341 "Received request for `%s' of type %u from local client\n",
342 GNUNET_h2s (&sm->query), (unsigned int) type);
343 lc = GSF_local_client_lookup_ (client);
345 /* detect duplicate UBLOCK requests */
346 if ((type == GNUNET_BLOCK_TYPE_FS_UBLOCK) ||
347 (type == GNUNET_BLOCK_TYPE_ANY))
352 prd = GSF_pending_request_get_data_ (cr->pr);
353 /* only unify with queries that hae not yet started local processing
354 (SEARCH_MESSAGE_OPTION_CONTINUED was always set) and that have a
355 matching query and type */
356 if ((GNUNET_YES != prd->has_started) &&
357 (0 != memcmp (&prd->query,
359 sizeof (struct GNUNET_HashCode))) &&
367 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
368 "Have existing request, merging content-seen lists.\n");
369 GSF_pending_request_update_ (cr->pr,
370 (const struct GNUNET_HashCode *) &sm[1],
372 GNUNET_STATISTICS_update (GSF_stats,
374 ("# client searches updated (merged content seen list)"),
379 GNUNET_STATISTICS_update (GSF_stats,
380 gettext_noop ("# client searches active"), 1,
382 cr = GNUNET_new (struct ClientRequest);
384 GNUNET_CONTAINER_DLL_insert (lc->cr_head,
387 options = GSF_PRO_LOCAL_REQUEST;
388 if (0 != (SEARCH_MESSAGE_OPTION_LOOPBACK_ONLY & ntohl (sm->options)))
389 options |= GSF_PRO_LOCAL_ONLY;
390 cr->pr = GSF_pending_request_create_ (options, type,
393 memcmp (&sm->target, &all_zeros,
394 sizeof (struct GNUNET_PeerIdentity)))
395 ? &sm->target : NULL, NULL, 0,
397 ntohl (sm->anonymity_level),
402 (const struct GNUNET_HashCode *) &sm[1], sc,
403 &client_response_handler, cr);
407 (SEARCH_MESSAGE_OPTION_CONTINUED & ntohl (sm->options))) ? GNUNET_NO :
413 * Transmit the given message by copying it to the target buffer
414 * "buf". "buf" will be NULL and "size" zero if the socket was closed
415 * for writing in the meantime. In that case, do nothing
416 * (the disconnect or shutdown handler will take care of the rest).
417 * If we were able to transmit messages and there are still more
418 * pending, ask core again for further calls to this function.
420 * @param cls closure, pointer to the `struct GSF_LocalClient`
421 * @param size number of bytes available in @a buf
422 * @param buf where the callee should write the message
423 * @return number of bytes written to @a buf
426 transmit_to_client (void *cls,
430 struct GSF_LocalClient *lc = cls;
432 struct ClientResponse *res;
439 while ((NULL != (res = lc->res_head)) && (res->msize <= size))
441 memcpy (&cbuf[msize], &res[1], res->msize);
444 GNUNET_CONTAINER_DLL_remove (lc->res_head, lc->res_tail, res);
449 GNUNET_SERVER_notify_transmit_ready (lc->client, res->msize,
450 GNUNET_TIME_UNIT_FOREVER_REL,
451 &transmit_to_client, lc);
457 * Transmit a message to the given local client as soon as possible.
458 * If the client disconnects before transmission, the message is
461 * @param lc recipient
462 * @param msg message to transmit to client
465 GSF_local_client_transmit_ (struct GSF_LocalClient *lc,
466 const struct GNUNET_MessageHeader *msg)
468 struct ClientResponse *res;
471 msize = ntohs (msg->size);
472 res = GNUNET_malloc (sizeof (struct ClientResponse) + msize);
478 GNUNET_CONTAINER_DLL_insert_tail (lc->res_head,
483 GNUNET_SERVER_notify_transmit_ready (lc->client, msize,
484 GNUNET_TIME_UNIT_FOREVER_REL,
485 &transmit_to_client, lc);
490 * A client disconnected from us. Tear down the local client
494 * @param client handle of the client
497 GSF_client_disconnect_handler_ (void *cls,
498 struct GNUNET_SERVER_Client *client)
500 struct GSF_LocalClient *pos;
501 struct ClientRequest *cr;
502 struct ClientResponse *res;
505 while ((pos != NULL) && (pos->client != client))
509 while (NULL != (cr = pos->cr_head))
511 if (NULL != cr->kill_task)
512 GNUNET_SCHEDULER_cancel (cr->kill_task);
513 client_request_destroy (cr, NULL);
515 while (NULL != (res = pos->res_head))
517 GNUNET_CONTAINER_DLL_remove (pos->res_head, pos->res_tail, res);
522 GNUNET_SERVER_notify_transmit_ready_cancel (pos->th);
525 GSF_handle_local_client_disconnect_ (pos);
526 GNUNET_CONTAINER_DLL_remove (client_head, client_tail, pos);
531 /* end of gnunet-service-fs_lc.c */