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- /*
- This file is part of GNUnet
- Copyright (C) 2012, 2013, 2016 GNUnet e.V.
- GNUnet is free software: you can redistribute it and/or modify it
- under the terms of the GNU Affero General Public License as published
- by the Free Software Foundation, either version 3 of the License,
- or (at your option) any later version.
- GNUnet is distributed in the hope that it will be useful, but
- WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- Affero General Public License for more details.
- You should have received a copy of the GNU Affero General Public License
- along with this program. If not, see <http://www.gnu.org/licenses/>.
- SPDX-License-Identifier: AGPL3.0-or-later
- */
- /**
- * @file regex/regex_api_search.c
- * @brief access regex service to discover
- * peers using matching strings
- * @author Maximilian Szengel
- * @author Christian Grothoff
- */
- #include "platform.h"
- #include "gnunet_protocols.h"
- #include "gnunet_util_lib.h"
- #include "gnunet_regex_service.h"
- #include "regex_ipc.h"
- #define LOG(kind, ...) GNUNET_log_from (kind, "regex-api", __VA_ARGS__)
- /**
- * Handle to store data about a regex search.
- */
- struct GNUNET_REGEX_Search
- {
- /**
- * Connection to the regex service.
- */
- struct GNUNET_MQ_Handle *mq;
- /**
- * Our configuration.
- */
- const struct GNUNET_CONFIGURATION_Handle *cfg;
- /**
- * Function to call with results.
- */
- GNUNET_REGEX_Found callback;
- /**
- * Closure for @e callback.
- */
- void *callback_cls;
- /**
- * Search string to transmit to the service.
- */
- char *string;
- };
- /**
- * (Re)connect to the REGEX service for the given search @a s.
- *
- * @param s context for the search search for
- */
- static void
- search_reconnect (struct GNUNET_REGEX_Search *s);
- /**
- * We got a response or disconnect after asking regex
- * to do the search. Check it is well-formed.
- *
- * @param cls the `struct GNUNET_REGEX_Search` to handle reply for
- * @param result the message
- * @return #GNUNET_SYSERR if @a rm is not well-formed.
- */
- static int
- check_search_response (void *cls,
- const struct ResultMessage *result)
- {
- uint16_t size = ntohs (result->header.size) - sizeof(*result);
- uint16_t gpl = ntohs (result->get_path_length);
- uint16_t ppl = ntohs (result->put_path_length);
- if (size != (gpl + ppl) * sizeof(struct GNUNET_PeerIdentity))
- {
- GNUNET_break (0);
- return GNUNET_SYSERR;
- }
- return GNUNET_OK;
- }
- /**
- * We got a response or disconnect after asking regex
- * to do the search. Handle it.
- *
- * @param cls the `struct GNUNET_REGEX_Search` to handle reply for
- * @param result the message
- */
- static void
- handle_search_response (void *cls,
- const struct ResultMessage *result)
- {
- struct GNUNET_REGEX_Search *s = cls;
- uint16_t gpl = ntohs (result->get_path_length);
- uint16_t ppl = ntohs (result->put_path_length);
- const struct GNUNET_PeerIdentity *pid;
- pid = &result->id;
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Got regex result %s\n",
- GNUNET_i2s (pid));
- s->callback (s->callback_cls,
- pid,
- &pid[1],
- gpl,
- &pid[1 + gpl],
- ppl);
- }
- /**
- * We got a disconnect after asking regex to do the announcement.
- * Retry.
- *
- * @param cls the `struct GNUNET_REGEX_Search` to retry
- * @param error error code
- */
- static void
- mq_error_handler (void *cls,
- enum GNUNET_MQ_Error error)
- {
- struct GNUNET_REGEX_Search *s = cls;
- GNUNET_MQ_destroy (s->mq);
- s->mq = NULL;
- search_reconnect (s);
- }
- /**
- * (Re)connect to the REGEX service for the given search @a s.
- *
- * @param s context for the search search for
- */
- static void
- search_reconnect (struct GNUNET_REGEX_Search *s)
- {
- struct GNUNET_MQ_MessageHandler handlers[] = {
- GNUNET_MQ_hd_var_size (search_response,
- GNUNET_MESSAGE_TYPE_REGEX_RESULT,
- struct ResultMessage,
- s),
- GNUNET_MQ_handler_end ()
- };
- size_t slen = strlen (s->string) + 1;
- struct GNUNET_MQ_Envelope *env;
- struct RegexSearchMessage *rsm;
- GNUNET_assert (NULL == s->mq);
- s->mq = GNUNET_CLIENT_connect (s->cfg,
- "regex",
- handlers,
- &mq_error_handler,
- s);
- if (NULL == s->mq)
- return;
- env = GNUNET_MQ_msg_extra (rsm,
- slen,
- GNUNET_MESSAGE_TYPE_REGEX_SEARCH);
- GNUNET_memcpy (&rsm[1],
- s->string,
- slen);
- GNUNET_MQ_send (s->mq,
- env);
- }
- /**
- * Search for a peer offering a regex matching certain string in the DHT.
- * The search runs until #GNUNET_REGEX_search_cancel() is called, even if results
- * are returned.
- *
- * @param cfg configuration to use
- * @param string String to match against the regexes in the DHT.
- * @param callback Callback for found peers.
- * @param callback_cls Closure for @c callback.
- * @return Handle to stop search and free resources.
- * Must be freed by calling #GNUNET_REGEX_search_cancel().
- */
- struct GNUNET_REGEX_Search *
- GNUNET_REGEX_search (const struct GNUNET_CONFIGURATION_Handle *cfg,
- const char *string,
- GNUNET_REGEX_Found callback,
- void *callback_cls)
- {
- struct GNUNET_REGEX_Search *s;
- size_t slen = strlen (string) + 1;
- if (slen + sizeof(struct RegexSearchMessage) >= GNUNET_MAX_MESSAGE_SIZE)
- {
- GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
- _ ("Search string `%s' is too long!\n"),
- string);
- GNUNET_break (0);
- return NULL;
- }
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Starting regex search for %s\n",
- string);
- s = GNUNET_new (struct GNUNET_REGEX_Search);
- s->cfg = cfg;
- s->string = GNUNET_strdup (string);
- s->callback = callback;
- s->callback_cls = callback_cls;
- search_reconnect (s);
- if (NULL == s->mq)
- {
- GNUNET_free (s->string);
- GNUNET_free (s);
- return NULL;
- }
- return s;
- }
- /**
- * Stop search and free all data used by a #GNUNET_REGEX_search() call.
- *
- * @param s Handle returned by a previous #GNUNET_REGEX_search() call.
- */
- void
- GNUNET_REGEX_search_cancel (struct GNUNET_REGEX_Search *s)
- {
- GNUNET_MQ_destroy (s->mq);
- GNUNET_free (s->string);
- GNUNET_free (s);
- }
- /* end of regex_api_search.c */
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