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;
65 * Replies to be transmitted to the client. The actual
66 * response message is allocated after this struct.
71 * This is a doubly-linked list.
73 struct ClientResponse *next;
76 * This is a doubly-linked list.
78 struct ClientResponse *prev;
81 * Client list entry this response belongs to.
83 struct GSF_LocalClient *lc;
86 * Number of bytes in the response.
95 struct GSF_LocalClient
99 * We keep clients in a DLL.
101 struct GSF_LocalClient *next;
104 * We keep clients in a DLL.
106 struct GSF_LocalClient *prev;
111 struct GNUNET_SERVER_Client *client;
114 * Head of list of requests performed on behalf
115 * of this client right now.
117 struct ClientRequest *cr_head;
120 * Tail of list of requests performed on behalf
121 * of this client right now.
123 struct ClientRequest *cr_tail;
126 * Head of linked list of responses.
128 struct ClientResponse *res_head;
131 * Tail of linked list of responses.
133 struct ClientResponse *res_tail;
136 * Context for sending replies.
138 struct GNUNET_CONNECTION_TransmitHandle *th;
144 * Head of linked list of our local clients.
146 static struct GSF_LocalClient *client_head;
150 * Head of linked list of our local clients.
152 static struct GSF_LocalClient *client_tail;
156 * Look up a local client record or create one if it
159 * @param client handle of the client
160 * @return handle to local client entry
162 struct GSF_LocalClient *
163 GSF_local_client_lookup_ (struct GNUNET_SERVER_Client *client)
165 struct GSF_LocalClient *pos;
168 while ( (pos != NULL) &&
169 (pos->client != client) )
173 pos = GNUNET_malloc (sizeof (struct GSF_LocalClient));
174 pos->client = client;
175 GNUNET_CONTAINER_DLL_insert (client_head,
183 * Handle a reply to a pending request. Also called if a request
184 * expires (then with data == NULL). The handler may be called
185 * many times (depending on the request type), but will not be
186 * called during or after a call to GSF_pending_request_cancel
187 * and will also not be called anymore after a call signalling
190 * @param cls user-specified closure
191 * @param eval evaluation of the result
192 * @param pr handle to the original pending request
193 * @param expiration when does 'data' expire?
194 * @param type type of the block
195 * @param data response data, NULL on request expiration
196 * @param data_len number of bytes in data
199 client_response_handler (void *cls,
200 enum GNUNET_BLOCK_EvaluationResult eval,
201 struct GSF_PendingRequest *pr,
202 struct GNUNET_TIME_Absolute expiration,
203 enum GNUNET_BLOCK_Type type,
207 struct ClientRequest *cr = cls;
208 struct GSF_LocalClient *lc;
209 struct PutMessage *pm;
210 const struct GSF_PendingRequestData *prd;
215 /* ugh, request 'timed out' -- how can this be? */
219 prd = GSF_pending_request_get_data_ (pr);
220 GNUNET_break (type != GNUNET_BLOCK_TYPE_ANY);
221 if ( (prd->type != type) &&
222 (prd->type != GNUNET_BLOCK_TYPE_ANY) )
227 GNUNET_STATISTICS_update (GSF_stats,
228 gettext_noop ("# replies received for local clients"),
231 GNUNET_assert (pr == cr->pr);
233 msize = sizeof (struct PutMessage) + data_len;
234 pm = GNUNET_malloc (msize);
235 pm->header.type = htons (GNUNET_MESSAGE_TYPE_FS_PUT);
236 pm->header.size = htons (msize);
237 pm->type = htonl (type);
238 pm->expiration = GNUNET_TIME_absolute_hton (expiration);
239 memcpy (&pm[1], data, data_len);
240 GSF_local_client_transmit_ (lc, &pm->header);
242 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
243 "Queued reply to query `%s' for local client\n",
244 GNUNET_h2s (&prd->query),
245 (unsigned int) prd->type);
247 if (eval != GNUNET_BLOCK_EVALUATION_OK_LAST)
249 GNUNET_CONTAINER_DLL_remove (lc->cr_head,
252 GSF_pending_request_cancel_ (cr->pr);
253 GNUNET_STATISTICS_update (GSF_stats,
254 gettext_noop ("# client searches active"),
263 * Handle START_SEARCH-message (search request from local client).
265 * @param client identification of the client
266 * @param message the actual message
267 * @return pending request handle for the request, NULL on error
269 struct GSF_PendingRequest *
270 GSF_local_client_start_search_handler_ (struct GNUNET_SERVER_Client *client,
271 const struct GNUNET_MessageHeader *message)
273 static GNUNET_HashCode all_zeros;
274 const struct SearchMessage *sm;
275 struct GSF_LocalClient *lc;
276 struct ClientRequest *cr;
277 struct GSF_PendingRequestData *prd;
280 enum GNUNET_BLOCK_Type type;
281 enum GSF_PendingRequestOptions options;
283 msize = ntohs (message->size);
284 if ( (msize < sizeof (struct SearchMessage)) ||
285 (0 != (msize - sizeof (struct SearchMessage)) % sizeof (GNUNET_HashCode)) )
288 GNUNET_SERVER_receive_done (client,
292 GNUNET_STATISTICS_update (GSF_stats,
293 gettext_noop ("# client searches received"),
296 sc = (msize - sizeof (struct SearchMessage)) / sizeof (GNUNET_HashCode);
297 sm = (const struct SearchMessage*) message;
298 type = ntohl (sm->type);
300 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
301 "Received request for `%s' of type %u from local client\n",
302 GNUNET_h2s (&sm->query),
303 (unsigned int) type);
305 lc = GSF_local_client_lookup_ (client);
307 /* detect duplicate KBLOCK requests */
308 if ( (type == GNUNET_BLOCK_TYPE_FS_KBLOCK) ||
309 (type == GNUNET_BLOCK_TYPE_FS_NBLOCK) ||
310 (type == GNUNET_BLOCK_TYPE_ANY) )
312 /* FIXME: this does currently not work to filter duplicate
313 results from *local* datastore since the local store is
314 queried before we continue to process additional
315 messages from the client! -- fix protocol? */
319 prd = GSF_pending_request_get_data_ (cr->pr);
320 if ( (0 != memcmp (&prd->query,
322 sizeof (GNUNET_HashCode))) &&
323 (prd->type == type) )
330 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
331 "Have existing request, merging content-seen lists.\n");
333 GSF_pending_request_update_ (cr->pr,
334 (const GNUNET_HashCode*) &sm[1],
336 GNUNET_STATISTICS_update (GSF_stats,
337 gettext_noop ("# client searches updated (merged content seen list)"),
340 GNUNET_SERVER_receive_done (client,
346 GNUNET_STATISTICS_update (GSF_stats,
347 gettext_noop ("# client searches active"),
350 cr = GNUNET_malloc (sizeof (struct ClientRequest));
352 GNUNET_CONTAINER_DLL_insert (lc->cr_head,
355 options = GSF_PRO_LOCAL_REQUEST;
356 if (0 != (1 & ntohl (sm->options)))
357 options |= GSF_PRO_LOCAL_ONLY;
358 cr->pr = GSF_pending_request_create_ (options,
361 (type == GNUNET_BLOCK_TYPE_FS_SBLOCK)
362 ? &sm->target /* namespace */
364 (0 != memcmp (&sm->target,
366 sizeof (GNUNET_HashCode)))
367 ? (const struct GNUNET_PeerIdentity*) &sm->target
370 ntohl (sm->anonymity_level),
374 (const GNUNET_HashCode*) &sm[1], sc,
375 &client_response_handler,
382 * Transmit the given message by copying it to the target buffer
383 * "buf". "buf" will be NULL and "size" zero if the socket was closed
384 * for writing in the meantime. In that case, do nothing
385 * (the disconnect or shutdown handler will take care of the rest).
386 * If we were able to transmit messages and there are still more
387 * pending, ask core again for further calls to this function.
389 * @param cls closure, pointer to the 'struct GSF_LocalClient'
390 * @param size number of bytes available in buf
391 * @param buf where the callee should write the message
392 * @return number of bytes written to buf
395 transmit_to_client (void *cls,
399 struct GSF_LocalClient *lc = cls;
401 struct ClientResponse *res;
408 while ( (NULL != (res = lc->res_head) ) &&
409 (res->msize <= size) )
411 memcpy (&cbuf[msize], &res[1], res->msize);
414 GNUNET_CONTAINER_DLL_remove (lc->res_head,
420 lc->th = GNUNET_SERVER_notify_transmit_ready (lc->client,
422 GNUNET_TIME_UNIT_FOREVER_REL,
430 * Transmit a message to the given local client as soon as possible.
431 * If the client disconnects before transmission, the message is
434 * @param lc recipient
435 * @param msg message to transmit to client
438 GSF_local_client_transmit_ (struct GSF_LocalClient *lc,
439 const struct GNUNET_MessageHeader *msg)
441 struct ClientResponse *res;
444 msize = ntohs (msg->size);
445 res = GNUNET_malloc (sizeof (struct ClientResponse) + msize);
448 memcpy (&res[1], msg, msize);
449 GNUNET_CONTAINER_DLL_insert_tail (lc->res_head,
453 lc->th = GNUNET_SERVER_notify_transmit_ready (lc->client,
455 GNUNET_TIME_UNIT_FOREVER_REL,
462 * A client disconnected from us. Tear down the local client
466 * @param client handle of the client
469 GSF_client_disconnect_handler_ (void *cls,
470 struct GNUNET_SERVER_Client *client)
472 struct GSF_LocalClient *pos;
473 struct ClientRequest *cr;
474 struct ClientResponse *res;
477 while ( (pos != NULL) &&
478 (pos->client != client) )
482 while (NULL != (cr = pos->cr_head))
484 GNUNET_CONTAINER_DLL_remove (pos->cr_head,
487 GSF_pending_request_cancel_ (cr->pr);
488 GNUNET_STATISTICS_update (GSF_stats,
489 gettext_noop ("# client searches active"),
494 while (NULL != (res = pos->res_head))
496 GNUNET_CONTAINER_DLL_remove (pos->res_head,
503 GNUNET_CONNECTION_notify_transmit_ready_cancel (pos->th);
506 GSF_handle_local_client_disconnect_ (pos);
507 GNUNET_CONTAINER_DLL_remove (client_head,
514 /* end of gnunet-service-fs_lc.c */