2 This file is part of GNUnet.
3 Copyright (C) 2009-2013, 2016, 2018 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
8 or (at your option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
22 * @brief library to access the GNS service
23 * @author Martin Schanzenbach
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_constants.h"
29 #include "gnunet_arm_service.h"
30 #include "gnunet_hello_lib.h"
31 #include "gnunet_protocols.h"
32 #include "gnunet_dht_service.h"
37 #define LOG(kind,...) GNUNET_log_from (kind, "gns-api",__VA_ARGS__)
40 * Handle to a lookup request
42 struct GNUNET_GNS_LookupRequest
48 struct GNUNET_GNS_LookupRequest *next;
53 struct GNUNET_GNS_LookupRequest *prev;
58 struct GNUNET_GNS_Handle *gns_handle;
61 * processor to call on lookup result
63 GNUNET_GNS_LookupResultProcessor lookup_proc;
66 * @e lookup_proc closure
71 * Envelope with the message for this queue entry.
73 struct GNUNET_MQ_Envelope *env;
84 * Reconnect to GNS service.
86 * @param handle the handle to the GNS service
89 reconnect (struct GNUNET_GNS_Handle *handle);
95 * @param cls the handle
98 reconnect_task (void *cls)
100 struct GNUNET_GNS_Handle *handle = cls;
102 handle->reconnect_task = NULL;
108 * Disconnect from service and then reconnect.
110 * @param handle our handle
113 force_reconnect (struct GNUNET_GNS_Handle *handle)
115 GNUNET_MQ_destroy (handle->mq);
117 handle->reconnect_backoff
118 = GNUNET_TIME_STD_BACKOFF (handle->reconnect_backoff);
119 handle->reconnect_task
120 = GNUNET_SCHEDULER_add_delayed (handle->reconnect_backoff,
127 * Generic error handler, called with the appropriate error code and
128 * the same closure specified at the creation of the message queue.
129 * Not every message queue implementation supports an error handler.
131 * @param cls closure with the `struct GNUNET_GNS_Handle *`
132 * @param error error code
135 mq_error_handler (void *cls,
136 enum GNUNET_MQ_Error error)
138 struct GNUNET_GNS_Handle *handle = cls;
140 LOG (GNUNET_ERROR_TYPE_WARNING,
141 "Problem with message queue. error: %i\n",
143 force_reconnect (handle);
148 * Check validity of message received from the GNS service
150 * @param cls the `struct GNUNET_GNS_Handle *`
151 * @param loookup_msg the incoming message
154 check_result (void *cls,
155 const struct LookupResultMessage *lookup_msg)
157 size_t mlen = ntohs (lookup_msg->header.size) - sizeof (*lookup_msg);
158 uint32_t rd_count = ntohl (lookup_msg->rd_count);
159 struct GNUNET_GNSRECORD_Data rd[rd_count];
163 GNUNET_GNSRECORD_records_deserialize (mlen,
164 (const char*) &lookup_msg[1],
169 return GNUNET_SYSERR;
176 * Handler for messages received from the GNS service
178 * @param cls the `struct GNUNET_GNS_Handle *`
179 * @param loookup_msg the incoming message
182 handle_result (void *cls,
183 const struct LookupResultMessage *lookup_msg)
185 struct GNUNET_GNS_Handle *handle = cls;
186 size_t mlen = ntohs (lookup_msg->header.size) - sizeof (*lookup_msg);
187 uint32_t rd_count = ntohl (lookup_msg->rd_count);
188 struct GNUNET_GNSRECORD_Data rd[rd_count];
189 uint32_t r_id = ntohl (lookup_msg->id);
190 struct GNUNET_GNS_LookupRequest *lr;
191 GNUNET_GNS_LookupResultProcessor proc;
194 LOG (GNUNET_ERROR_TYPE_DEBUG,
195 "Received lookup reply from GNS service (%u records)\n",
196 (unsigned int) rd_count);
197 for (lr = handle->lookup_head; NULL != lr; lr = lr->next)
198 if (lr->r_id == r_id)
202 proc = lr->lookup_proc;
203 proc_cls = lr->proc_cls;
205 GNUNET_assert (GNUNET_OK ==
206 GNUNET_GNSRECORD_records_deserialize (mlen,
207 (const char*) &lookup_msg[1],
213 GNUNET_CONTAINER_DLL_remove (handle->lookup_head,
217 GNUNET_MQ_discard (lr->env);
223 * Reconnect to GNS service.
225 * @param handle the handle to the GNS service
228 reconnect (struct GNUNET_GNS_Handle *handle)
230 struct GNUNET_MQ_MessageHandler handlers[] = {
231 GNUNET_MQ_hd_var_size (result,
232 GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT,
233 struct LookupResultMessage,
235 GNUNET_MQ_handler_end ()
238 GNUNET_assert (NULL == handle->mq);
239 LOG (GNUNET_ERROR_TYPE_DEBUG,
240 "Trying to connect to GNS\n");
241 handle->mq = GNUNET_CLIENT_connect (handle->cfg,
246 if (NULL == handle->mq)
248 for (struct GNUNET_GNS_LookupRequest *lh = handle->lookup_head;
251 GNUNET_MQ_send_copy (handle->mq,
257 * Initialize the connection with the GNS service.
259 * @param cfg configuration to use
260 * @return handle to the GNS service, or NULL on error
262 struct GNUNET_GNS_Handle *
263 GNUNET_GNS_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
265 struct GNUNET_GNS_Handle *handle;
267 handle = GNUNET_new (struct GNUNET_GNS_Handle);
270 if (NULL == handle->mq)
272 GNUNET_free (handle);
280 * Shutdown connection with the GNS service.
282 * @param handle handle of the GNS connection to stop
285 GNUNET_GNS_disconnect (struct GNUNET_GNS_Handle *handle)
287 if (NULL != handle->mq)
289 GNUNET_MQ_destroy (handle->mq);
292 if (NULL != handle->reconnect_task)
294 GNUNET_SCHEDULER_cancel (handle->reconnect_task);
295 handle->reconnect_task = NULL;
297 GNUNET_assert (NULL == handle->lookup_head);
298 GNUNET_free (handle);
303 * Cancel pending lookup request
305 * @param lr the lookup request to cancel
306 * @return closure from the lookup result processor
309 GNUNET_GNS_lookup_cancel (struct GNUNET_GNS_LookupRequest *lr)
311 struct GNUNET_GNS_Handle *handle = lr->gns_handle;
314 GNUNET_CONTAINER_DLL_remove (handle->lookup_head,
317 GNUNET_MQ_discard (lr->env);
325 * Perform an asynchronous lookup operation on the GNS.
327 * @param handle handle to the GNS service
328 * @param name the name to look up
329 * @param zone the zone to start the resolution in
330 * @param type the record type to look up
331 * @param options local options for the lookup
332 * @param proc processor to call on result
333 * @param proc_cls closure for @a proc
334 * @return handle to the get request
336 struct GNUNET_GNS_LookupRequest*
337 GNUNET_GNS_lookup (struct GNUNET_GNS_Handle *handle,
339 const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
341 enum GNUNET_GNS_LocalOptions options,
342 GNUNET_GNS_LookupResultProcessor proc,
345 /* IPC to shorten gns names, return shorten_handle */
346 struct LookupMessage *lookup_msg;
347 struct GNUNET_GNS_LookupRequest *lr;
355 LOG (GNUNET_ERROR_TYPE_DEBUG,
356 "Trying to lookup `%s' in GNS\n",
358 nlen = strlen (name) + 1;
359 if (nlen >= GNUNET_MAX_MESSAGE_SIZE - sizeof (*lr))
364 lr = GNUNET_new (struct GNUNET_GNS_LookupRequest);
365 lr->gns_handle = handle;
366 lr->lookup_proc = proc;
367 lr->proc_cls = proc_cls;
368 lr->r_id = handle->r_id_gen++;
369 lr->env = GNUNET_MQ_msg_extra (lookup_msg,
371 GNUNET_MESSAGE_TYPE_GNS_LOOKUP);
372 lookup_msg->id = htonl (lr->r_id);
373 lookup_msg->options = htons ((uint16_t) options);
374 lookup_msg->zone = *zone;
375 lookup_msg->type = htonl (type);
376 GNUNET_memcpy (&lookup_msg[1],
379 GNUNET_CONTAINER_DLL_insert (handle->lookup_head,
382 if (NULL != handle->mq)
383 GNUNET_MQ_send_copy (handle->mq,
389 /* end of gns_api.c */