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Diffstat (limited to 'src/cadet/gnunet-service-cadet_dht.c')
-rw-r--r-- | src/cadet/gnunet-service-cadet_dht.c | 351 |
1 files changed, 351 insertions, 0 deletions
diff --git a/src/cadet/gnunet-service-cadet_dht.c b/src/cadet/gnunet-service-cadet_dht.c new file mode 100644 index 000000000..f00c0caf3 --- /dev/null +++ b/src/cadet/gnunet-service-cadet_dht.c | |||
@@ -0,0 +1,351 @@ | |||
1 | /* | ||
2 | This file is part of GNUnet. | ||
3 | Copyright (C) 2013, 2017 GNUnet e.V. | ||
4 | |||
5 | GNUnet is free software; you can redistribute it and/or modify | ||
6 | it under the terms of the GNU General Public License as published | ||
7 | by the Free Software Foundation; either version 3, or (at your | ||
8 | option) any later version. | ||
9 | |||
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 | General Public License for more details. | ||
14 | |||
15 | You should have received a copy of the GNU General Public License | ||
16 | along with GNUnet; see the file COPYING. If not, write to the | ||
17 | Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, | ||
18 | Boston, MA 02110-1301, USA. | ||
19 | */ | ||
20 | /** | ||
21 | * @file cadet/gnunet-service-cadet_dht.c | ||
22 | * @brief Information we track per peer. | ||
23 | * @author Bartlomiej Polot | ||
24 | * @author Christian Grothoff | ||
25 | */ | ||
26 | |||
27 | #include "platform.h" | ||
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" | ||
36 | |||
37 | /** | ||
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. | ||
42 | */ | ||
43 | #define STARTUP_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 500) | ||
44 | |||
45 | /** | ||
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. | ||
49 | */ | ||
50 | #define CHANGE_DELAY GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_MILLISECONDS, 100) | ||
51 | |||
52 | |||
53 | #define LOG(level, ...) GNUNET_log_from (level,"cadet-dht",__VA_ARGS__) | ||
54 | |||
55 | |||
56 | /** | ||
57 | * Handle for DHT searches. | ||
58 | */ | ||
59 | struct GCD_search_handle | ||
60 | { | ||
61 | /** | ||
62 | * DHT_GET handle. | ||
63 | */ | ||
64 | struct GNUNET_DHT_GetHandle *dhtget; | ||
65 | |||
66 | }; | ||
67 | |||
68 | |||
69 | /** | ||
70 | * Handle to use DHT. | ||
71 | */ | ||
72 | static struct GNUNET_DHT_Handle *dht_handle; | ||
73 | |||
74 | /** | ||
75 | * How often to PUT own ID in the DHT. | ||
76 | */ | ||
77 | static struct GNUNET_TIME_Relative id_announce_time; | ||
78 | |||
79 | /** | ||
80 | * DHT replication level, see DHT API: #GNUNET_DHT_get_start(), #GNUNET_DHT_put(). | ||
81 | */ | ||
82 | static unsigned long long dht_replication_level; | ||
83 | |||
84 | /** | ||
85 | * Task to periodically announce itself in the network. | ||
86 | */ | ||
87 | static struct GNUNET_SCHEDULER_Task *announce_id_task; | ||
88 | |||
89 | /** | ||
90 | * Delay for the next ID announce. | ||
91 | */ | ||
92 | static struct GNUNET_TIME_Relative announce_delay; | ||
93 | |||
94 | |||
95 | /** | ||
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. | ||
99 | * | ||
100 | * @param cls closure | ||
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 | ||
110 | */ | ||
111 | static void | ||
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, | ||
119 | size_t size, | ||
120 | const void *data) | ||
121 | { | ||
122 | const struct GNUNET_HELLO_Message *hello = data; | ||
123 | struct CadetPeer *peer; | ||
124 | |||
125 | GCPP_try_path_from_dht (get_path, | ||
126 | get_path_length, | ||
127 | put_path, | ||
128 | put_path_length); | ||
129 | if ( (size >= sizeof (struct GNUNET_HELLO_Message)) && | ||
130 | (ntohs (hello->header.size) == size) && | ||
131 | (size == GNUNET_HELLO_size (hello)) ) | ||
132 | { | ||
133 | peer = GCP_get (&put_path[0], | ||
134 | GNUNET_YES); | ||
135 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
136 | "Got HELLO for %s\n", | ||
137 | GCP_2s (peer)); | ||
138 | GCP_set_hello (peer, | ||
139 | hello); | ||
140 | } | ||
141 | } | ||
142 | |||
143 | |||
144 | /** | ||
145 | * Periodically announce self id in the DHT | ||
146 | * | ||
147 | * @param cls closure | ||
148 | */ | ||
149 | static void | ||
150 | announce_id (void *cls) | ||
151 | { | ||
152 | struct GNUNET_HashCode phash; | ||
153 | const struct GNUNET_HELLO_Message *hello; | ||
154 | size_t size; | ||
155 | struct GNUNET_TIME_Absolute expiration; | ||
156 | struct GNUNET_TIME_Relative next_put; | ||
157 | |||
158 | hello = GCH_get_mine (); | ||
159 | size = (NULL != hello) ? GNUNET_HELLO_size (hello) : 0; | ||
160 | if (0 == size) | ||
161 | { | ||
162 | expiration = GNUNET_TIME_absolute_add (GNUNET_TIME_absolute_get (), | ||
163 | announce_delay); | ||
164 | announce_delay = GNUNET_TIME_STD_BACKOFF (announce_delay); | ||
165 | } | ||
166 | else | ||
167 | { | ||
168 | expiration = GNUNET_HELLO_get_last_expiration (hello); | ||
169 | announce_delay = GNUNET_TIME_UNIT_SECONDS; | ||
170 | } | ||
171 | |||
172 | /* Call again in id_announce_time, unless HELLO expires first, | ||
173 | * but wait at least 1s. */ | ||
174 | next_put | ||
175 | = GNUNET_TIME_absolute_get_remaining (expiration); | ||
176 | next_put | ||
177 | = GNUNET_TIME_relative_min (next_put, | ||
178 | id_announce_time); | ||
179 | next_put | ||
180 | = GNUNET_TIME_relative_max (next_put, | ||
181 | GNUNET_TIME_UNIT_SECONDS); | ||
182 | announce_id_task | ||
183 | = GNUNET_SCHEDULER_add_delayed (next_put, | ||
184 | &announce_id, | ||
185 | cls); | ||
186 | GNUNET_STATISTICS_update (stats, | ||
187 | "# DHT announce", | ||
188 | 1, | ||
189 | GNUNET_NO); | ||
190 | memset (&phash, | ||
191 | 0, | ||
192 | sizeof (phash)); | ||
193 | GNUNET_memcpy (&phash, | ||
194 | &my_full_id, | ||
195 | sizeof (my_full_id)); | ||
196 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
197 | "Announcing my HELLO (%u bytes) in the DHT\n", | ||
198 | size); | ||
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 */ | ||
210 | } | ||
211 | |||
212 | |||
213 | /** | ||
214 | * Function called by the HELLO subsystem whenever OUR hello | ||
215 | * changes. Re-triggers the DHT PUT immediately. | ||
216 | */ | ||
217 | void | ||
218 | GCD_hello_update () | ||
219 | { | ||
220 | if (NULL == announce_id_task) | ||
221 | return; /* too early */ | ||
222 | GNUNET_SCHEDULER_cancel (announce_id_task); | ||
223 | announce_id_task | ||
224 | = GNUNET_SCHEDULER_add_delayed (CHANGE_DELAY, | ||
225 | &announce_id, | ||
226 | NULL); | ||
227 | } | ||
228 | |||
229 | |||
230 | /** | ||
231 | * Initialize the DHT subsystem. | ||
232 | * | ||
233 | * @param c Configuration. | ||
234 | */ | ||
235 | void | ||
236 | GCD_init (const struct GNUNET_CONFIGURATION_Handle *c) | ||
237 | { | ||
238 | if (GNUNET_OK != | ||
239 | GNUNET_CONFIGURATION_get_value_number (c, | ||
240 | "CADET", | ||
241 | "DHT_REPLICATION_LEVEL", | ||
242 | &dht_replication_level)) | ||
243 | { | ||
244 | GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING, | ||
245 | "CADET", | ||
246 | "DHT_REPLICATION_LEVEL", | ||
247 | "USING DEFAULT"); | ||
248 | dht_replication_level = 3; | ||
249 | } | ||
250 | |||
251 | if (GNUNET_OK != | ||
252 | GNUNET_CONFIGURATION_get_value_time (c, | ||
253 | "CADET", | ||
254 | "ID_ANNOUNCE_TIME", | ||
255 | &id_announce_time)) | ||
256 | { | ||
257 | GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_ERROR, | ||
258 | "CADET", | ||
259 | "ID_ANNOUNCE_TIME", | ||
260 | "MISSING"); | ||
261 | GNUNET_SCHEDULER_shutdown (); | ||
262 | return; | ||
263 | } | ||
264 | |||
265 | dht_handle = GNUNET_DHT_connect (c, | ||
266 | 64); | ||
267 | GNUNET_break (NULL != dht_handle); | ||
268 | announce_delay = GNUNET_TIME_UNIT_SECONDS; | ||
269 | announce_id_task = GNUNET_SCHEDULER_add_delayed (STARTUP_DELAY, | ||
270 | &announce_id, | ||
271 | NULL); | ||
272 | } | ||
273 | |||
274 | |||
275 | /** | ||
276 | * Shut down the DHT subsystem. | ||
277 | */ | ||
278 | void | ||
279 | GCD_shutdown (void) | ||
280 | { | ||
281 | if (NULL != dht_handle) | ||
282 | { | ||
283 | GNUNET_DHT_disconnect (dht_handle); | ||
284 | dht_handle = NULL; | ||
285 | } | ||
286 | if (NULL != announce_id_task) | ||
287 | { | ||
288 | GNUNET_SCHEDULER_cancel (announce_id_task); | ||
289 | announce_id_task = NULL; | ||
290 | } | ||
291 | } | ||
292 | |||
293 | |||
294 | /** | ||
295 | * Search DHT for paths to @a peeR_id | ||
296 | * | ||
297 | * @param peer_id peer to search for | ||
298 | * @return handle to abort search | ||
299 | */ | ||
300 | struct GCD_search_handle * | ||
301 | GCD_search (const struct GNUNET_PeerIdentity *peer_id) | ||
302 | { | ||
303 | struct GNUNET_HashCode phash; | ||
304 | struct GCD_search_handle *h; | ||
305 | |||
306 | GNUNET_STATISTICS_update (stats, | ||
307 | "# DHT search", | ||
308 | 1, | ||
309 | GNUNET_NO); | ||
310 | memset (&phash, | ||
311 | 0, | ||
312 | sizeof (phash)); | ||
313 | GNUNET_memcpy (&phash, | ||
314 | peer_id, | ||
315 | sizeof (*peer_id)); | ||
316 | |||
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, | ||
324 | NULL, /* xquery */ | ||
325 | 0, /* xquery bits */ | ||
326 | &dht_get_id_handler, | ||
327 | h); | ||
328 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
329 | "Starting DHT GET for peer %s (%p)\n", | ||
330 | GNUNET_i2s (peer_id), | ||
331 | h); | ||
332 | return h; | ||
333 | } | ||
334 | |||
335 | |||
336 | /** | ||
337 | * Stop DHT search started with #GCD_search(). | ||
338 | * | ||
339 | * @param h handle to search to stop | ||
340 | */ | ||
341 | void | ||
342 | GCD_search_stop (struct GCD_search_handle *h) | ||
343 | { | ||
344 | LOG (GNUNET_ERROR_TYPE_DEBUG, | ||
345 | "Stopping DHT GET %p\n", | ||
346 | h); | ||
347 | GNUNET_DHT_get_stop (h->dhtget); | ||
348 | GNUNET_free (h); | ||
349 | } | ||
350 | |||
351 | /* end of gnunet-service-cadet_dht.c */ | ||