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21 * @file cadet/gnunet-service-cadet_dht.c
22 * @brief Information we track per peer.
23 * @author Bartlomiej Polot
24 * @author Christian Grothoff
28 #include "gnunet_util_lib.h"
29 #include "gnunet_dht_service.h"
30 #include "gnunet_statistics_service.h"
31 #include "gnunet-service-cadet.h"
32 #include "gnunet-service-cadet_dht.h"
33 #include "gnunet-service-cadet_hello.h"
34 #include "gnunet-service-cadet_peer.h"
35 #include "gnunet-service-cadet_paths.h"
38 * How long do we wait before first announcing our presence to the DHT.
39 * Used to wait for our HELLO to be available. Note that we also get
40 * notifications when our HELLO is ready, so this is just the maximum
41 * we wait for the first notification.
43 #define STARTUP_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 500)
46 * How long do we wait after we get an updated HELLO before publishing?
47 * Allows for the HELLO to be updated again quickly, for example in
48 * case multiple addresses changed and we got a partial update.
50 #define CHANGE_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100)
53 #define LOG(level, ...) GNUNET_log_from (level,"cadet-dht",__VA_ARGS__)
57 * Handle for DHT searches.
59 struct GCD_search_handle
64 struct GNUNET_DHT_GetHandle *dhtget;
72 static struct GNUNET_DHT_Handle *dht_handle;
75 * How often to PUT own ID in the DHT.
77 static struct GNUNET_TIME_Relative id_announce_time;
80 * DHT replication level, see DHT API: #GNUNET_DHT_get_start(), #GNUNET_DHT_put().
82 static unsigned long long dht_replication_level;
85 * Task to periodically announce itself in the network.
87 static struct GNUNET_SCHEDULER_Task *announce_id_task;
90 * Delay for the next ID announce.
92 static struct GNUNET_TIME_Relative announce_delay;
96 * Function to process paths received for a new peer addition. The recorded
97 * paths form the initial tunnel, which can be optimized later.
98 * Called on each result obtained for the DHT search.
101 * @param exp when will this value expire
102 * @param key key of the result
103 * @param get_path path of the get request
104 * @param get_path_length lenght of @a get_path
105 * @param put_path path of the put request
106 * @param put_path_length length of the @a put_path
107 * @param type type of the result
108 * @param size number of bytes in data
109 * @param data pointer to the result data
112 dht_get_id_handler (void *cls, struct GNUNET_TIME_Absolute exp,
113 const struct GNUNET_HashCode *key,
114 const struct GNUNET_PeerIdentity *get_path,
115 unsigned int get_path_length,
116 const struct GNUNET_PeerIdentity *put_path,
117 unsigned int put_path_length,
118 enum GNUNET_BLOCK_Type type,
122 const struct GNUNET_HELLO_Message *hello = data;
123 struct CadetPeer *peer;
125 GCPP_try_path_from_dht (get_path,
129 if ( (size >= sizeof (struct GNUNET_HELLO_Message)) &&
130 (ntohs (hello->header.size) == size) &&
131 (size == GNUNET_HELLO_size (hello)) )
133 peer = GCP_get (&put_path[0],
135 LOG (GNUNET_ERROR_TYPE_DEBUG,
136 "Got HELLO for %s\n",
145 * Periodically announce self id in the DHT
150 announce_id (void *cls)
152 struct GNUNET_HashCode phash;
153 const struct GNUNET_HELLO_Message *hello;
155 struct GNUNET_TIME_Absolute expiration;
156 struct GNUNET_TIME_Relative next_put;
158 hello = GCH_get_mine ();
159 size = (NULL != hello) ? GNUNET_HELLO_size (hello) : 0;
162 expiration = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get (),
164 announce_delay = GNUNET_TIME_STD_BACKOFF (announce_delay);
168 expiration = GNUNET_HELLO_get_last_expiration (hello);
169 announce_delay = GNUNET_TIME_UNIT_SECONDS;
172 /* Call again in id_announce_time, unless HELLO expires first,
173 * but wait at least 1s. */
175 = GNUNET_TIME_absolute_get_remaining (expiration);
177 = GNUNET_TIME_relative_min (next_put,
180 = GNUNET_TIME_relative_max (next_put,
181 GNUNET_TIME_UNIT_SECONDS);
183 = GNUNET_SCHEDULER_add_delayed (next_put,
186 GNUNET_STATISTICS_update (stats,
193 GNUNET_memcpy (&phash,
195 sizeof (my_full_id));
196 LOG (GNUNET_ERROR_TYPE_DEBUG,
197 "Announcing my HELLO (%u bytes) in the DHT\n",
199 GNUNET_DHT_put (dht_handle, /* DHT handle */
200 &phash, /* Key to use */
201 dht_replication_level, /* Replication level */
202 GNUNET_DHT_RO_RECORD_ROUTE
203 | GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE, /* DHT options */
204 GNUNET_BLOCK_TYPE_DHT_HELLO, /* Block type */
205 size, /* Size of the data */
206 (const char *) hello, /* Data itself */
207 expiration, /* Data expiration */
208 NULL, /* Continuation */
209 NULL); /* Continuation closure */
214 * Function called by the HELLO subsystem whenever OUR hello
215 * changes. Re-triggers the DHT PUT immediately.
220 if (NULL == announce_id_task)
221 return; /* too early */
222 GNUNET_SCHEDULER_cancel (announce_id_task);
224 = GNUNET_SCHEDULER_add_delayed (CHANGE_DELAY,
231 * Initialize the DHT subsystem.
233 * @param c Configuration.
236 GCD_init (const struct GNUNET_CONFIGURATION_Handle *c)
239 GNUNET_CONFIGURATION_get_value_number (c,
241 "DHT_REPLICATION_LEVEL",
242 &dht_replication_level))
244 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
246 "DHT_REPLICATION_LEVEL",
248 dht_replication_level = 3;
252 GNUNET_CONFIGURATION_get_value_time (c,
257 GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR,
261 GNUNET_SCHEDULER_shutdown ();
265 dht_handle = GNUNET_DHT_connect (c,
267 GNUNET_break (NULL != dht_handle);
268 announce_delay = GNUNET_TIME_UNIT_SECONDS;
269 announce_id_task = GNUNET_SCHEDULER_add_delayed (STARTUP_DELAY,
276 * Shut down the DHT subsystem.
281 if (NULL != dht_handle)
283 GNUNET_DHT_disconnect (dht_handle);
286 if (NULL != announce_id_task)
288 GNUNET_SCHEDULER_cancel (announce_id_task);
289 announce_id_task = NULL;
295 * Search DHT for paths to @a peeR_id
297 * @param peer_id peer to search for
298 * @return handle to abort search
300 struct GCD_search_handle *
301 GCD_search (const struct GNUNET_PeerIdentity *peer_id)
303 struct GNUNET_HashCode phash;
304 struct GCD_search_handle *h;
306 GNUNET_STATISTICS_update (stats,
313 GNUNET_memcpy (&phash,
317 h = GNUNET_new (struct GCD_search_handle);
318 h->dhtget = GNUNET_DHT_get_start (dht_handle, /* handle */
319 GNUNET_BLOCK_TYPE_DHT_HELLO, /* type */
320 &phash, /* key to search */
321 dht_replication_level, /* replication level */
322 GNUNET_DHT_RO_RECORD_ROUTE |
323 GNUNET_DHT_RO_DEMULTIPLEX_EVERYWHERE,
328 LOG (GNUNET_ERROR_TYPE_DEBUG,
329 "Starting DHT GET for peer %s (%p)\n",
330 GNUNET_i2s (peer_id),
337 * Stop DHT search started with #GCD_search().
339 * @param h handle to search to stop
342 GCD_search_stop (struct GCD_search_handle *h)
344 LOG (GNUNET_ERROR_TYPE_DEBUG,
345 "Stopping DHT GET %p\n",
347 GNUNET_DHT_get_stop (h->dhtget);
351 /* end of gnunet-service-cadet_dht.c */