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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
189 client_request_destroy (void *cls)
191 struct ClientRequest *cr = cls;
192 struct GSF_LocalClient *lc;
194 cr->kill_task = NULL;
196 GNUNET_CONTAINER_DLL_remove (lc->cr_head,
199 GSF_pending_request_cancel_ (cr->pr,
201 GNUNET_STATISTICS_update (GSF_stats,
202 gettext_noop ("# client searches active"),
210 * Handle a reply to a pending request. Also called if a request
211 * expires (then with data == NULL). The handler may be called
212 * many times (depending on the request type), but will not be
213 * called during or after a call to #GSF_pending_request_cancel()
214 * and will also not be called anymore after a call signalling
217 * @param cls user-specified closure
218 * @param eval evaluation of the result
219 * @param pr handle to the original pending request
220 * @param reply_anonymity_level anonymity level for the reply, UINT32_MAX for "unknown"
221 * @param expiration when does @a data expire?
222 * @param last_transmission when was the last time we've tried to download this block? (FOREVER if unknown)
223 * @param type type of the block
224 * @param data response data, NULL on request expiration
225 * @param data_len number of bytes in @a data
228 client_response_handler (void *cls,
229 enum GNUNET_BLOCK_EvaluationResult eval,
230 struct GSF_PendingRequest *pr,
231 uint32_t reply_anonymity_level,
232 struct GNUNET_TIME_Absolute expiration,
233 struct GNUNET_TIME_Absolute last_transmission,
234 enum GNUNET_BLOCK_Type type,
238 struct ClientRequest *cr = cls;
239 struct GSF_LocalClient *lc;
240 struct ClientPutMessage *pm;
241 const struct GSF_PendingRequestData *prd;
246 /* local-only request, with no result, clean up. */
247 if (NULL == cr->kill_task)
248 cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy,
252 prd = GSF_pending_request_get_data_ (pr);
253 GNUNET_break (type != GNUNET_BLOCK_TYPE_ANY);
254 if ((prd->type != type) && (prd->type != GNUNET_BLOCK_TYPE_ANY))
259 GNUNET_STATISTICS_update (GSF_stats,
261 ("# replies received for local clients"), 1,
263 GNUNET_assert (pr == cr->pr);
265 msize = sizeof (struct ClientPutMessage) + data_len;
267 char buf[msize] GNUNET_ALIGN;
269 pm = (struct ClientPutMessage *) buf;
270 pm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_PUT);
271 pm->header.size = htons (msize);
272 pm->type = htonl (type);
273 pm->expiration = GNUNET_TIME_absolute_hton (expiration);
274 pm->last_transmission = GNUNET_TIME_absolute_hton (last_transmission);
275 pm->num_transmissions = htonl (prd->num_transmissions);
276 pm->respect_offered = htonl (prd->respect_offered);
277 memcpy (&pm[1], data, data_len);
278 GSF_local_client_transmit_ (lc, &pm->header);
280 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
281 "Queued reply to query `%s' for local client\n",
282 GNUNET_h2s (&prd->query));
283 if (GNUNET_BLOCK_EVALUATION_OK_LAST != eval)
285 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
286 "Evaluation %d - keeping query alive\n",
290 if (NULL == cr->kill_task)
291 cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy, cr);
296 * Handle START_SEARCH-message (search request from local client).
297 * Only responsible for creating the request entry itself and setting
298 * up reply callback and cancellation on client disconnect. Does NOT
299 * execute the actual request strategy (planning).
301 * @param client identification of the client
302 * @param message the actual message
303 * @param prptr where to store the pending request handle for the request
304 * @return #GNUNET_YES to start local processing,
305 * #GNUNET_NO to not (yet) start local processing,
306 * #GNUNET_SYSERR on error
309 GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
310 const struct GNUNET_MessageHeader *message,
311 struct GSF_PendingRequest **prptr)
313 static struct GNUNET_PeerIdentity all_zeros;
314 const struct SearchMessage *sm;
315 struct GSF_LocalClient *lc;
316 struct ClientRequest *cr;
317 struct GSF_PendingRequestData *prd;
320 enum GNUNET_BLOCK_Type type;
321 enum GSF_PendingRequestOptions options;
323 msize = ntohs (message->size);
324 if ((msize < sizeof (struct SearchMessage)) ||
325 (0 != (msize - sizeof (struct SearchMessage)) % sizeof (struct GNUNET_HashCode)))
329 return GNUNET_SYSERR;
331 GNUNET_STATISTICS_update (GSF_stats,
332 gettext_noop ("# client searches received"),
335 sc = (msize - sizeof (struct SearchMessage)) / sizeof (struct GNUNET_HashCode);
336 sm = (const struct SearchMessage *) message;
337 type = ntohl (sm->type);
338 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
339 "Received request for `%s' of type %u from local client\n",
340 GNUNET_h2s (&sm->query), (unsigned int) type);
341 lc = GSF_local_client_lookup_ (client);
343 /* detect duplicate UBLOCK requests */
344 if ((type == GNUNET_BLOCK_TYPE_FS_UBLOCK) ||
345 (type == GNUNET_BLOCK_TYPE_ANY))
350 prd = GSF_pending_request_get_data_ (cr->pr);
351 /* only unify with queries that hae not yet started local processing
352 (SEARCH_MESSAGE_OPTION_CONTINUED was always set) and that have a
353 matching query and type */
354 if ((GNUNET_YES != prd->has_started) &&
355 (0 != memcmp (&prd->query,
357 sizeof (struct GNUNET_HashCode))) &&
365 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
366 "Have existing request, merging content-seen lists.\n");
367 GSF_pending_request_update_ (cr->pr,
368 (const struct GNUNET_HashCode *) &sm[1],
370 GNUNET_STATISTICS_update (GSF_stats,
372 ("# client searches updated (merged content seen list)"),
377 GNUNET_STATISTICS_update (GSF_stats,
378 gettext_noop ("# client searches active"), 1,
380 cr = GNUNET_new (struct ClientRequest);
382 GNUNET_CONTAINER_DLL_insert (lc->cr_head,
385 options = GSF_PRO_LOCAL_REQUEST;
386 if (0 != (SEARCH_MESSAGE_OPTION_LOOPBACK_ONLY & ntohl (sm->options)))
387 options |= GSF_PRO_LOCAL_ONLY;
388 cr->pr = GSF_pending_request_create_ (options, type,
391 memcmp (&sm->target, &all_zeros,
392 sizeof (struct GNUNET_PeerIdentity)))
393 ? &sm->target : NULL, NULL, 0,
395 ntohl (sm->anonymity_level),
400 (const struct GNUNET_HashCode *) &sm[1], sc,
401 &client_response_handler, cr);
405 (SEARCH_MESSAGE_OPTION_CONTINUED & ntohl (sm->options))) ? GNUNET_NO :
411 * Transmit the given message by copying it to the target buffer
412 * "buf". "buf" will be NULL and "size" zero if the socket was closed
413 * for writing in the meantime. In that case, do nothing
414 * (the disconnect or shutdown handler will take care of the rest).
415 * If we were able to transmit messages and there are still more
416 * pending, ask core again for further calls to this function.
418 * @param cls closure, pointer to the `struct GSF_LocalClient`
419 * @param size number of bytes available in @a buf
420 * @param buf where the callee should write the message
421 * @return number of bytes written to @a buf
424 transmit_to_client (void *cls,
428 struct GSF_LocalClient *lc = cls;
430 struct ClientResponse *res;
437 while ((NULL != (res = lc->res_head)) && (res->msize <= size))
439 memcpy (&cbuf[msize], &res[1], res->msize);
442 GNUNET_CONTAINER_DLL_remove (lc->res_head, lc->res_tail, res);
447 GNUNET_SERVER_notify_transmit_ready (lc->client, res->msize,
448 GNUNET_TIME_UNIT_FOREVER_REL,
449 &transmit_to_client, lc);
455 * Transmit a message to the given local client as soon as possible.
456 * If the client disconnects before transmission, the message is
459 * @param lc recipient
460 * @param msg message to transmit to client
463 GSF_local_client_transmit_ (struct GSF_LocalClient *lc,
464 const struct GNUNET_MessageHeader *msg)
466 struct ClientResponse *res;
469 msize = ntohs (msg->size);
470 res = GNUNET_malloc (sizeof (struct ClientResponse) + msize);
476 GNUNET_CONTAINER_DLL_insert_tail (lc->res_head,
481 GNUNET_SERVER_notify_transmit_ready (lc->client, msize,
482 GNUNET_TIME_UNIT_FOREVER_REL,
483 &transmit_to_client, lc);
488 * A client disconnected from us. Tear down the local client
492 * @param client handle of the client
495 GSF_client_disconnect_handler_ (void *cls,
496 struct GNUNET_SERVER_Client *client)
498 struct GSF_LocalClient *pos;
499 struct ClientRequest *cr;
500 struct ClientResponse *res;
503 while ((pos != NULL) && (pos->client != client))
507 while (NULL != (cr = pos->cr_head))
509 if (NULL != cr->kill_task)
510 GNUNET_SCHEDULER_cancel (cr->kill_task);
511 client_request_destroy (cr);
513 while (NULL != (res = pos->res_head))
515 GNUNET_CONTAINER_DLL_remove (pos->res_head, pos->res_tail, res);
520 GNUNET_SERVER_notify_transmit_ready_cancel (pos->th);
523 GSF_handle_local_client_disconnect_ (pos);
524 GNUNET_CONTAINER_DLL_remove (client_head, client_tail, pos);
529 /* end of gnunet-service-fs_lc.c */