2 This file is part of GNUnet.
3 (C) 2011 Christian Grothoff (and other contributing authors)
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12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
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22 * @file fs/gnunet-service-fs_lc.c
23 * @brief API to handle 'connected peers'
24 * @author Christian Grothoff
28 #include "gnunet-service-fs.h"
29 #include "gnunet-service-fs_lc.h"
30 #include "gnunet-service-fs_cp.h"
31 #include "gnunet-service-fs_pr.h"
35 * Doubly-linked list of requests we are performing
36 * on behalf of the same client.
42 * This is a doubly-linked list.
44 struct ClientRequest *next;
47 * This is a doubly-linked list.
49 struct ClientRequest *prev;
52 * Request this entry represents.
54 struct GSF_PendingRequest *pr;
57 * Client list this request belongs to.
59 struct GSF_LocalClient *lc;
62 * Task scheduled to destroy the request.
64 GNUNET_SCHEDULER_TaskIdentifier kill_task;
70 * Replies to be transmitted to the client. The actual
71 * response message is allocated after this struct.
76 * This is a doubly-linked list.
78 struct ClientResponse *next;
81 * This is a doubly-linked list.
83 struct ClientResponse *prev;
86 * Client list entry this response belongs to.
88 struct GSF_LocalClient *lc;
91 * Number of bytes in the response.
100 struct GSF_LocalClient
104 * We keep clients in a DLL.
106 struct GSF_LocalClient *next;
109 * We keep clients in a DLL.
111 struct GSF_LocalClient *prev;
116 struct GNUNET_SERVER_Client *client;
119 * Head of list of requests performed on behalf
120 * of this client right now.
122 struct ClientRequest *cr_head;
125 * Tail of list of requests performed on behalf
126 * of this client right now.
128 struct ClientRequest *cr_tail;
131 * Head of linked list of responses.
133 struct ClientResponse *res_head;
136 * Tail of linked list of responses.
138 struct ClientResponse *res_tail;
141 * Context for sending replies.
143 struct GNUNET_CONNECTION_TransmitHandle *th;
149 * Head of linked list of our local clients.
151 static struct GSF_LocalClient *client_head;
155 * Head of linked list of our local clients.
157 static struct GSF_LocalClient *client_tail;
161 * Look up a local client record or create one if it
164 * @param client handle of the client
165 * @return handle to local client entry
167 struct GSF_LocalClient *
168 GSF_local_client_lookup_ (struct GNUNET_SERVER_Client *client)
170 struct GSF_LocalClient *pos;
173 while ( (pos != NULL) &&
174 (pos->client != client) )
178 pos = GNUNET_malloc (sizeof (struct GSF_LocalClient));
179 pos->client = client;
180 GNUNET_CONTAINER_DLL_insert (client_head,
188 * Free the given client request.
190 * @param cls the client request to free
191 * @param tc task context
194 client_request_destroy (void *cls,
195 const struct GNUNET_SCHEDULER_TaskContext *tc)
197 struct ClientRequest *cr = cls;
198 struct GSF_LocalClient *lc;
200 cr->kill_task = GNUNET_SCHEDULER_NO_TASK;
202 GNUNET_CONTAINER_DLL_remove (lc->cr_head,
205 GSF_pending_request_cancel_ (cr->pr);
206 GNUNET_STATISTICS_update (GSF_stats,
207 gettext_noop ("# client searches active"),
215 * Handle a reply to a pending request. Also called if a request
216 * expires (then with data == NULL). The handler may be called
217 * many times (depending on the request type), but will not be
218 * called during or after a call to GSF_pending_request_cancel
219 * and will also not be called anymore after a call signalling
222 * @param cls user-specified closure
223 * @param eval evaluation of the result
224 * @param pr handle to the original pending request
225 * @param expiration when does 'data' expire?
226 * @param type type of the block
227 * @param data response data, NULL on request expiration
228 * @param data_len number of bytes in data
231 client_response_handler (void *cls,
232 enum GNUNET_BLOCK_EvaluationResult eval,
233 struct GSF_PendingRequest *pr,
234 struct GNUNET_TIME_Absolute expiration,
235 enum GNUNET_BLOCK_Type type,
239 struct ClientRequest *cr = cls;
240 struct GSF_LocalClient *lc;
241 struct PutMessage *pm;
242 const struct GSF_PendingRequestData *prd;
247 /* ugh, request 'timed out' -- how can this be? */
251 prd = GSF_pending_request_get_data_ (pr);
252 GNUNET_break (type != GNUNET_BLOCK_TYPE_ANY);
253 if ( (prd->type != type) &&
254 (prd->type != GNUNET_BLOCK_TYPE_ANY) )
259 GNUNET_STATISTICS_update (GSF_stats,
260 gettext_noop ("# replies received for local clients"),
263 GNUNET_assert (pr == cr->pr);
265 msize = sizeof (struct PutMessage) + data_len;
266 pm = GNUNET_malloc (msize);
267 pm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_PUT);
268 pm->header.size = htons (msize);
269 pm->type = htonl (type);
270 pm->expiration = GNUNET_TIME_absolute_hton (expiration);
271 memcpy (&pm[1], data, data_len);
272 GSF_local_client_transmit_ (lc, &pm->header);
274 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
275 "Queued reply to query `%s' for local client\n",
276 GNUNET_h2s (&prd->query),
277 (unsigned int) prd->type);
279 if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
281 cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy,
287 * Handle START_SEARCH-message (search request from local client).
289 * @param client identification of the client
290 * @param message the actual message
291 * @return pending request handle for the request, NULL on error
293 struct GSF_PendingRequest *
294 GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
295 const struct GNUNET_MessageHeader *message)
297 static GNUNET_HashCode all_zeros;
298 const struct SearchMessage *sm;
299 struct GSF_LocalClient *lc;
300 struct ClientRequest *cr;
301 struct GSF_PendingRequestData *prd;
304 enum GNUNET_BLOCK_Type type;
305 enum GSF_PendingRequestOptions options;
307 msize = ntohs (message->size);
308 if ( (msize < sizeof (struct SearchMessage)) ||
309 (0 != (msize - sizeof (struct SearchMessage)) % sizeof (GNUNET_HashCode)) )
312 GNUNET_SERVER_receive_done (client,
316 GNUNET_STATISTICS_update (GSF_stats,
317 gettext_noop ("# client searches received"),
320 sc = (msize - sizeof (struct SearchMessage)) / sizeof (GNUNET_HashCode);
321 sm = (const struct SearchMessage*) message;
322 type = ntohl (sm->type);
324 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
325 "Received request for `%s' of type %u from local client\n",
326 GNUNET_h2s (&sm->query),
327 (unsigned int) type);
329 lc = GSF_local_client_lookup_ (client);
331 /* detect duplicate KBLOCK requests */
332 if ( (type == GNUNET_BLOCK_TYPE_FS_KBLOCK) ||
333 (type == GNUNET_BLOCK_TYPE_FS_NBLOCK) ||
334 (type == GNUNET_BLOCK_TYPE_ANY) )
336 /* FIXME: this does currently not work to filter duplicate
337 results from *local* datastore since the local store is
338 queried before we continue to process additional
339 messages from the client! -- fix protocol? */
343 prd = GSF_pending_request_get_data_ (cr->pr);
344 if ( (0 != memcmp (&prd->query,
346 sizeof (GNUNET_HashCode))) &&
347 (prd->type == type) )
354 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
355 "Have existing request, merging content-seen lists.\n");
357 GSF_pending_request_update_ (cr->pr,
358 (const GNUNET_HashCode*) &sm[1],
360 GNUNET_STATISTICS_update (GSF_stats,
361 gettext_noop ("# client searches updated (merged content seen list)"),
364 GNUNET_SERVER_receive_done (client,
370 GNUNET_STATISTICS_update (GSF_stats,
371 gettext_noop ("# client searches active"),
374 cr = GNUNET_malloc (sizeof (struct ClientRequest));
376 GNUNET_CONTAINER_DLL_insert (lc->cr_head,
379 options = GSF_PRO_LOCAL_REQUEST;
380 if (0 != (1 & ntohl (sm->options)))
381 options |= GSF_PRO_LOCAL_ONLY;
382 cr->pr = GSF_pending_request_create_ (options,
385 (type == GNUNET_BLOCK_TYPE_FS_SBLOCK)
386 ? &sm->target /* namespace */
388 (0 != memcmp (&sm->target,
390 sizeof (GNUNET_HashCode)))
391 ? (const struct GNUNET_PeerIdentity*) &sm->target
394 ntohl (sm->anonymity_level),
398 (const GNUNET_HashCode*) &sm[1], sc,
399 &client_response_handler,
406 * Transmit the given message by copying it to the target buffer
407 * "buf". "buf" will be NULL and "size" zero if the socket was closed
408 * for writing in the meantime. In that case, do nothing
409 * (the disconnect or shutdown handler will take care of the rest).
410 * If we were able to transmit messages and there are still more
411 * pending, ask core again for further calls to this function.
413 * @param cls closure, pointer to the 'struct GSF_LocalClient'
414 * @param size number of bytes available in buf
415 * @param buf where the callee should write the message
416 * @return number of bytes written to buf
419 transmit_to_client (void *cls,
423 struct GSF_LocalClient *lc = cls;
425 struct ClientResponse *res;
432 while ( (NULL != (res = lc->res_head) ) &&
433 (res->msize <= size) )
435 memcpy (&cbuf[msize], &res[1], res->msize);
438 GNUNET_CONTAINER_DLL_remove (lc->res_head,
444 lc->th = GNUNET_SERVER_notify_transmit_ready (lc->client,
446 GNUNET_TIME_UNIT_FOREVER_REL,
454 * Transmit a message to the given local client as soon as possible.
455 * If the client disconnects before transmission, the message is
458 * @param lc recipient
459 * @param msg message to transmit to client
462 GSF_local_client_transmit_ (struct GSF_LocalClient *lc,
463 const struct GNUNET_MessageHeader *msg)
465 struct ClientResponse *res;
468 msize = ntohs (msg->size);
469 res = GNUNET_malloc (sizeof (struct ClientResponse) + msize);
472 memcpy (&res[1], msg, msize);
473 GNUNET_CONTAINER_DLL_insert_tail (lc->res_head,
477 lc->th = GNUNET_SERVER_notify_transmit_ready (lc->client,
479 GNUNET_TIME_UNIT_FOREVER_REL,
486 * A client disconnected from us. Tear down the local client
490 * @param client handle of the client
493 GSF_client_disconnect_handler_ (void *cls,
494 struct GNUNET_SERVER_Client *client)
496 struct GSF_LocalClient *pos;
497 struct ClientRequest *cr;
498 struct ClientResponse *res;
501 while ( (pos != NULL) &&
502 (pos->client != client) )
506 while (NULL != (cr = pos->cr_head))
508 GNUNET_CONTAINER_DLL_remove (pos->cr_head,
511 GSF_pending_request_cancel_ (cr->pr);
512 GNUNET_STATISTICS_update (GSF_stats,
513 gettext_noop ("# client searches active"),
516 if (GNUNET_SCHEDULER_NO_TASK != cr->kill_task)
517 GNUNET_SCHEDULER_cancel (cr->kill_task);
520 while (NULL != (res = pos->res_head))
522 GNUNET_CONTAINER_DLL_remove (pos->res_head,
529 GNUNET_CONNECTION_notify_transmit_ready_cancel (pos->th);
532 GSF_handle_local_client_disconnect_ (pos);
533 GNUNET_CONTAINER_DLL_remove (client_head,
540 /* end of gnunet-service-fs_lc.c */