123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431 |
- /*
- This file is part of GNUnet.
- Copyright (C) 2009-2020 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 gns/gns_api.c
- * @brief library to access the GNS service
- * @author Martin Schanzenbach
- * @author Christian Grothoff
- */
- #include "platform.h"
- #include "gnunet_util_lib.h"
- #include "gnunet_constants.h"
- #include "gnunet_arm_service.h"
- #include "gnunet_hello_lib.h"
- #include "gnunet_protocols.h"
- #include "gnunet_dht_service.h"
- #include "gns.h"
- #include "gns_api.h"
- #define LOG(kind, ...) GNUNET_log_from (kind, "gns-api", __VA_ARGS__)
- /**
- * Default recursion depth limit to apply if
- * the application does not specify any.
- */
- #define DEFAULT_LIMIT 128
- /**
- * Handle to a lookup request
- */
- struct GNUNET_GNS_LookupRequest
- {
- /**
- * DLL
- */
- struct GNUNET_GNS_LookupRequest *next;
- /**
- * DLL
- */
- struct GNUNET_GNS_LookupRequest *prev;
- /**
- * handle to gns
- */
- struct GNUNET_GNS_Handle *gns_handle;
- /**
- * processor to call on lookup result
- */
- GNUNET_GNS_LookupResultProcessor lookup_proc;
- /**
- * @e lookup_proc closure
- */
- void *proc_cls;
- /**
- * Envelope with the message for this queue entry.
- */
- struct GNUNET_MQ_Envelope *env;
- /**
- * request id
- */
- uint32_t r_id;
- };
- /**
- * Reconnect to GNS service.
- *
- * @param handle the handle to the GNS service
- */
- static void
- reconnect (struct GNUNET_GNS_Handle *handle);
- /**
- * Reconnect to GNS
- *
- * @param cls the handle
- */
- static void
- reconnect_task (void *cls)
- {
- struct GNUNET_GNS_Handle *handle = cls;
- handle->reconnect_task = NULL;
- reconnect (handle);
- }
- /**
- * Disconnect from service and then reconnect.
- *
- * @param handle our handle
- */
- static void
- force_reconnect (struct GNUNET_GNS_Handle *handle)
- {
- GNUNET_MQ_destroy (handle->mq);
- handle->mq = NULL;
- handle->reconnect_backoff
- = GNUNET_TIME_STD_BACKOFF (handle->reconnect_backoff);
- handle->reconnect_task
- = GNUNET_SCHEDULER_add_delayed (handle->reconnect_backoff,
- &reconnect_task,
- handle);
- }
- /**
- * Generic error handler, called with the appropriate error code and
- * the same closure specified at the creation of the message queue.
- * Not every message queue implementation supports an error handler.
- *
- * @param cls closure with the `struct GNUNET_GNS_Handle *`
- * @param error error code
- */
- static void
- mq_error_handler (void *cls,
- enum GNUNET_MQ_Error error)
- {
- struct GNUNET_GNS_Handle *handle = cls;
- LOG (GNUNET_ERROR_TYPE_WARNING,
- "Problem with message queue. error: %i\n",
- error);
- force_reconnect (handle);
- }
- /**
- * Check validity of message received from the GNS service
- *
- * @param cls the `struct GNUNET_GNS_Handle *`
- * @param loookup_msg the incoming message
- */
- static int
- check_result (void *cls,
- const struct LookupResultMessage *lookup_msg)
- {
- size_t mlen = ntohs (lookup_msg->header.size) - sizeof(*lookup_msg);
- uint32_t rd_count = ntohl (lookup_msg->rd_count);
- struct GNUNET_GNSRECORD_Data rd[rd_count];
- (void) cls;
- if (GNUNET_SYSERR ==
- GNUNET_GNSRECORD_records_deserialize (mlen,
- (const char *) &lookup_msg[1],
- rd_count,
- rd))
- {
- GNUNET_break (0);
- return GNUNET_SYSERR;
- }
- return GNUNET_OK;
- }
- /**
- * Handler for messages received from the GNS service
- *
- * @param cls the `struct GNUNET_GNS_Handle *`
- * @param loookup_msg the incoming message
- */
- static void
- handle_result (void *cls,
- const struct LookupResultMessage *lookup_msg)
- {
- struct GNUNET_GNS_Handle *handle = cls;
- size_t mlen = ntohs (lookup_msg->header.size) - sizeof(*lookup_msg);
- uint32_t rd_count = ntohl (lookup_msg->rd_count);
- struct GNUNET_GNSRECORD_Data rd[rd_count];
- uint32_t r_id = ntohl (lookup_msg->id);
- struct GNUNET_GNS_LookupRequest *lr;
- GNUNET_GNS_LookupResultProcessor proc;
- void *proc_cls;
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Received lookup reply from GNS service (%u records)\n",
- (unsigned int) rd_count);
- for (lr = handle->lookup_head; NULL != lr; lr = lr->next)
- if (lr->r_id == r_id)
- break;
- if (NULL == lr)
- return;
- proc = lr->lookup_proc;
- proc_cls = lr->proc_cls;
- GNUNET_assert (GNUNET_OK ==
- GNUNET_GNSRECORD_records_deserialize (mlen,
- (const
- char *) &lookup_msg[1],
- rd_count,
- rd));
- proc (proc_cls,
- rd_count,
- rd);
- GNUNET_CONTAINER_DLL_remove (handle->lookup_head,
- handle->lookup_tail,
- lr);
- if (NULL != lr->env)
- GNUNET_MQ_discard (lr->env);
- GNUNET_free (lr);
- }
- /**
- * Reconnect to GNS service.
- *
- * @param handle the handle to the GNS service
- */
- static void
- reconnect (struct GNUNET_GNS_Handle *handle)
- {
- struct GNUNET_MQ_MessageHandler handlers[] = {
- GNUNET_MQ_hd_var_size (result,
- GNUNET_MESSAGE_TYPE_GNS_LOOKUP_RESULT,
- struct LookupResultMessage,
- handle),
- GNUNET_MQ_handler_end ()
- };
- GNUNET_assert (NULL == handle->mq);
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Trying to connect to GNS\n");
- handle->mq = GNUNET_CLIENT_connect (handle->cfg,
- "gns",
- handlers,
- &mq_error_handler,
- handle);
- if (NULL == handle->mq)
- return;
- for (struct GNUNET_GNS_LookupRequest *lh = handle->lookup_head;
- NULL != lh;
- lh = lh->next)
- GNUNET_MQ_send_copy (handle->mq,
- lh->env);
- }
- /**
- * Initialize the connection with the GNS service.
- *
- * @param cfg configuration to use
- * @return handle to the GNS service, or NULL on error
- */
- struct GNUNET_GNS_Handle *
- GNUNET_GNS_connect (const struct GNUNET_CONFIGURATION_Handle *cfg)
- {
- struct GNUNET_GNS_Handle *handle;
- handle = GNUNET_new (struct GNUNET_GNS_Handle);
- handle->cfg = cfg;
- reconnect (handle);
- if (NULL == handle->mq)
- {
- GNUNET_free (handle);
- return NULL;
- }
- return handle;
- }
- /**
- * Shutdown connection with the GNS service.
- *
- * @param handle handle of the GNS connection to stop
- */
- void
- GNUNET_GNS_disconnect (struct GNUNET_GNS_Handle *handle)
- {
- if (NULL != handle->mq)
- {
- GNUNET_MQ_destroy (handle->mq);
- handle->mq = NULL;
- }
- if (NULL != handle->reconnect_task)
- {
- GNUNET_SCHEDULER_cancel (handle->reconnect_task);
- handle->reconnect_task = NULL;
- }
- GNUNET_assert (NULL == handle->lookup_head);
- GNUNET_free (handle);
- }
- /**
- * Cancel pending lookup request
- *
- * @param lr the lookup request to cancel
- * @return closure from the lookup result processor
- */
- void *
- GNUNET_GNS_lookup_cancel (struct GNUNET_GNS_LookupRequest *lr)
- {
- struct GNUNET_GNS_Handle *handle = lr->gns_handle;
- void *ret;
- GNUNET_CONTAINER_DLL_remove (handle->lookup_head,
- handle->lookup_tail,
- lr);
- GNUNET_MQ_discard (lr->env);
- ret = lr->proc_cls;
- GNUNET_free (lr);
- return ret;
- }
- /**
- * Perform an asynchronous lookup operation on the GNS.
- *
- * @param handle handle to the GNS service
- * @param name the name to look up (in UTF-8 encoding)
- * @param zone zone to look in
- * @param type the GNS record type to look for
- * @param options local options for the lookup
- * @param recursion_depth_limit maximum number of zones
- * that the lookup may (still) traverse
- * @param proc function to call on result
- * @param proc_cls closure for @a proc
- * @return handle to the queued request
- */
- struct GNUNET_GNS_LookupRequest *
- GNUNET_GNS_lookup_limited (struct GNUNET_GNS_Handle *handle,
- const char *name,
- const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
- uint32_t type,
- enum GNUNET_GNS_LocalOptions options,
- uint16_t recursion_depth_limit,
- GNUNET_GNS_LookupResultProcessor proc,
- void *proc_cls)
- {
- /* IPC to shorten gns names, return shorten_handle */
- struct LookupMessage *lookup_msg;
- struct GNUNET_GNS_LookupRequest *lr;
- size_t nlen;
- if (NULL == name)
- {
- GNUNET_break (0);
- return NULL;
- }
- LOG (GNUNET_ERROR_TYPE_DEBUG,
- "Trying to lookup `%s' in GNS\n",
- name);
- nlen = strlen (name) + 1;
- if (nlen >= GNUNET_MAX_MESSAGE_SIZE - sizeof(*lr))
- {
- GNUNET_break (0);
- return NULL;
- }
- lr = GNUNET_new (struct GNUNET_GNS_LookupRequest);
- lr->gns_handle = handle;
- lr->lookup_proc = proc;
- lr->proc_cls = proc_cls;
- lr->r_id = handle->r_id_gen++;
- lr->env = GNUNET_MQ_msg_extra (lookup_msg,
- nlen,
- GNUNET_MESSAGE_TYPE_GNS_LOOKUP);
- lookup_msg->id = htonl (lr->r_id);
- lookup_msg->options = htons ((uint16_t) options);
- lookup_msg->recursion_depth_limit
- = htons (recursion_depth_limit);
- lookup_msg->zone = *zone;
- lookup_msg->type = htonl (type);
- GNUNET_memcpy (&lookup_msg[1],
- name,
- nlen);
- GNUNET_CONTAINER_DLL_insert (handle->lookup_head,
- handle->lookup_tail,
- lr);
- if (NULL != handle->mq)
- GNUNET_MQ_send_copy (handle->mq,
- lr->env);
- return lr;
- }
- /**
- * Perform an asynchronous lookup operation on the GNS.
- *
- * @param handle handle to the GNS service
- * @param name the name to look up (in UTF-8 encoding)
- * @param zone the zone to start the resolution in
- * @param type the record type to look up
- * @param options local options for the lookup
- * @param proc processor to call on result
- * @param proc_cls closure for @a proc
- * @return handle to the get request
- */
- struct GNUNET_GNS_LookupRequest*
- GNUNET_GNS_lookup (struct GNUNET_GNS_Handle *handle,
- const char *name,
- const struct GNUNET_CRYPTO_EcdsaPublicKey *zone,
- uint32_t type,
- enum GNUNET_GNS_LocalOptions options,
- GNUNET_GNS_LookupResultProcessor proc,
- void *proc_cls)
- {
- return GNUNET_GNS_lookup_limited (handle,
- name,
- zone,
- type,
- options,
- DEFAULT_LIMIT,
- proc,
- proc_cls);
- }
- /* end of gns_api.c */
|