2 This file is part of GNUnet.
3 (C) 2011 Christian Grothoff (and other contributing authors)
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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;
269 pm = (struct PutMessage*) 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 memcpy (&pm[1], data, data_len);
275 GSF_local_client_transmit_ (lc, &pm->header);
278 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
279 "Queued reply to query `%s' for local client\n",
280 GNUNET_h2s (&prd->query),
281 (unsigned int) prd->type);
283 if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
285 cr->kill_task = GNUNET_SCHEDULER_add_now (&client_request_destroy,
291 * Handle START_SEARCH-message (search request from local client).
293 * @param client identification of the client
294 * @param message the actual message
295 * @return pending request handle for the request, NULL on error
297 struct GSF_PendingRequest *
298 GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
299 const struct GNUNET_MessageHeader *message)
301 static GNUNET_HashCode all_zeros;
302 const struct SearchMessage *sm;
303 struct GSF_LocalClient *lc;
304 struct ClientRequest *cr;
305 struct GSF_PendingRequestData *prd;
308 enum GNUNET_BLOCK_Type type;
309 enum GSF_PendingRequestOptions options;
311 msize = ntohs (message->size);
312 if ( (msize < sizeof (struct SearchMessage)) ||
313 (0 != (msize - sizeof (struct SearchMessage)) % sizeof (GNUNET_HashCode)) )
316 GNUNET_SERVER_receive_done (client,
320 GNUNET_STATISTICS_update (GSF_stats,
321 gettext_noop ("# client searches received"),
324 sc = (msize - sizeof (struct SearchMessage)) / sizeof (GNUNET_HashCode);
325 sm = (const struct SearchMessage*) message;
326 type = ntohl (sm->type);
328 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
329 "Received request for `%s' of type %u from local client\n",
330 GNUNET_h2s (&sm->query),
331 (unsigned int) type);
333 lc = GSF_local_client_lookup_ (client);
335 /* detect duplicate KBLOCK requests */
336 if ( (type == GNUNET_BLOCK_TYPE_FS_KBLOCK) ||
337 (type == GNUNET_BLOCK_TYPE_FS_NBLOCK) ||
338 (type == GNUNET_BLOCK_TYPE_ANY) )
340 /* FIXME: this does currently not work to filter duplicate
341 results from *local* datastore since the local store is
342 queried before we continue to process additional
343 messages from the client! -- fix protocol? */
347 prd = GSF_pending_request_get_data_ (cr->pr);
348 if ( (0 != memcmp (&prd->query,
350 sizeof (GNUNET_HashCode))) &&
351 (prd->type == type) )
358 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
359 "Have existing request, merging content-seen lists.\n");
361 GSF_pending_request_update_ (cr->pr,
362 (const GNUNET_HashCode*) &sm[1],
364 GNUNET_STATISTICS_update (GSF_stats,
365 gettext_noop ("# client searches updated (merged content seen list)"),
368 GNUNET_SERVER_receive_done (client,
374 GNUNET_STATISTICS_update (GSF_stats,
375 gettext_noop ("# client searches active"),
378 cr = GNUNET_malloc (sizeof (struct ClientRequest));
380 GNUNET_CONTAINER_DLL_insert (lc->cr_head,
383 options = GSF_PRO_LOCAL_REQUEST;
384 if (0 != (1 & ntohl (sm->options)))
385 options |= GSF_PRO_LOCAL_ONLY;
386 cr->pr = GSF_pending_request_create_ (options,
389 (type == GNUNET_BLOCK_TYPE_FS_SBLOCK)
390 ? &sm->target /* namespace */
392 (0 != memcmp (&sm->target,
394 sizeof (GNUNET_HashCode)))
395 ? (const struct GNUNET_PeerIdentity*) &sm->target
398 ntohl (sm->anonymity_level),
402 (const GNUNET_HashCode*) &sm[1], sc,
403 &client_response_handler,
410 * Transmit the given message by copying it to the target buffer
411 * "buf". "buf" will be NULL and "size" zero if the socket was closed
412 * for writing in the meantime. In that case, do nothing
413 * (the disconnect or shutdown handler will take care of the rest).
414 * If we were able to transmit messages and there are still more
415 * pending, ask core again for further calls to this function.
417 * @param cls closure, pointer to the 'struct GSF_LocalClient'
418 * @param size number of bytes available in buf
419 * @param buf where the callee should write the message
420 * @return number of bytes written to buf
423 transmit_to_client (void *cls,
427 struct GSF_LocalClient *lc = cls;
429 struct ClientResponse *res;
436 while ( (NULL != (res = lc->res_head) ) &&
437 (res->msize <= size) )
439 memcpy (&cbuf[msize], &res[1], res->msize);
442 GNUNET_CONTAINER_DLL_remove (lc->res_head,
448 lc->th = GNUNET_SERVER_notify_transmit_ready (lc->client,
450 GNUNET_TIME_UNIT_FOREVER_REL,
458 * Transmit a message to the given local client as soon as possible.
459 * If the client disconnects before transmission, the message is
462 * @param lc recipient
463 * @param msg message to transmit to client
466 GSF_local_client_transmit_ (struct GSF_LocalClient *lc,
467 const struct GNUNET_MessageHeader *msg)
469 struct ClientResponse *res;
472 msize = ntohs (msg->size);
473 res = GNUNET_malloc (sizeof (struct ClientResponse) + msize);
476 memcpy (&res[1], msg, msize);
477 GNUNET_CONTAINER_DLL_insert_tail (lc->res_head,
481 lc->th = GNUNET_SERVER_notify_transmit_ready (lc->client,
483 GNUNET_TIME_UNIT_FOREVER_REL,
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) &&
506 (pos->client != client) )
510 while (NULL != (cr = pos->cr_head))
512 GNUNET_CONTAINER_DLL_remove (pos->cr_head,
515 GSF_pending_request_cancel_ (cr->pr);
516 GNUNET_STATISTICS_update (GSF_stats,
517 gettext_noop ("# client searches active"),
520 if (GNUNET_SCHEDULER_NO_TASK != cr->kill_task)
521 GNUNET_SCHEDULER_cancel (cr->kill_task);
524 while (NULL != (res = pos->res_head))
526 GNUNET_CONTAINER_DLL_remove (pos->res_head,
533 GNUNET_CONNECTION_notify_transmit_ready_cancel (pos->th);
536 GSF_handle_local_client_disconnect_ (pos);
537 GNUNET_CONTAINER_DLL_remove (client_head,
544 /* end of gnunet-service-fs_lc.c */