summaryrefslogtreecommitdiff
path: root/src/transport/gnunet-service-transport_hello.c
blob: 8b38a673e9173dee83d27af94a16a7833bc07978 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
/*
     This file is part of GNUnet.
     (C) 2010,2011 Christian Grothoff (and other contributing authors)

     GNUnet is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published
     by the Free Software Foundation; either version 3, 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
     General Public License for more details.

     You should have received a copy of the GNU General Public License
     along with GNUnet; see the file COPYING.  If not, write to the
     Free Software Foundation, Inc., 59 Temple Place - Suite 330,
     Boston, MA 02111-1307, USA.
*/

/**
 * @file transport/gnunet-service-transport_hello.c
 * @brief hello management implementation
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_constants.h"
#include "gnunet_hello_lib.h"
#include "gnunet_peerinfo_service.h"
#include "gnunet_statistics_service.h"
#include "gnunet-service-transport_hello.h"
#include "gnunet-service-transport.h"
#include "gnunet-service-transport_plugins.h"


/**
 * How often do we refresh our HELLO (due to expiration concerns)?
 */
#define HELLO_REFRESH_PERIOD GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_HOURS, 6)


/**
 * Entry in linked list of network addresses for ourselves.  Also
 * includes a cached signature for 'struct TransportPongMessage's.
 */
struct OwnAddressList
{
  /**
   * This is a doubly-linked list.
   */
  struct OwnAddressList *next;

  /**
   * This is a doubly-linked list.
   */
  struct OwnAddressList *prev;

  /**
   * The address.
   */
  struct GNUNET_HELLO_Address *address;

  /**
   * How long until the current signature expires? (ZERO if the
   * signature was never created).
   */
  struct GNUNET_TIME_Absolute pong_sig_expires;

  /**
   * Signature for a 'struct TransportPongMessage' for this address.
   */
  struct GNUNET_CRYPTO_RsaSignature pong_signature;

};


/**
 * Our HELLO message.
 */
static struct GNUNET_HELLO_Message *our_hello;

/**
 * Function to call on HELLO changes.
 */
static GST_HelloCallback hello_cb;

/**
 * Closure for 'hello_cb'.
 */
static void *hello_cb_cls;

/**
 * Head of my addresses.
 */
struct OwnAddressList *oal_head;

/**
 * Tail of my addresses.
 */
struct OwnAddressList *oal_tail;

/**
 * Identifier of 'refresh_hello' task.
 */
static GNUNET_SCHEDULER_TaskIdentifier hello_task;


/**
 * Closure for 'address_generator'.
 */
struct GeneratorContext
{
  /**
   * Where are we in the DLL?
   */
  struct OwnAddressList *addr_pos;

  /**
   * When do addresses expire?
   */
  struct GNUNET_TIME_Absolute expiration;
};


/**
 * Add an address from the 'OwnAddressList' to the buffer.
 *
 * @param cls the 'struct GeneratorContext'
 * @param max maximum number of bytes left
 * @param buf where to write the address
 */
static size_t
address_generator (void *cls, size_t max, void *buf)
{
  struct GeneratorContext *gc = cls;
  size_t ret;

  if (NULL == gc->addr_pos)
    return 0;
  ret =
    GNUNET_HELLO_add_address (gc->addr_pos->address, gc->expiration,
			      buf, max);
  gc->addr_pos = gc->addr_pos->next;
  return ret;
}


/**
 * Construct our HELLO message from all of the addresses of
 * all of the transports.
 *
 * @param cls unused
 * @param tc scheduler context
 */
static void
refresh_hello_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct GeneratorContext gc;

  hello_task = GNUNET_SCHEDULER_NO_TASK;
  gc.addr_pos = oal_head;
  gc.expiration =
      GNUNET_TIME_relative_to_absolute
      (GNUNET_CONSTANTS_HELLO_ADDRESS_EXPIRATION);
  GNUNET_free (our_hello);
  our_hello = GNUNET_HELLO_create (&GST_my_public_key, &address_generator, &gc);
#if DEBUG_TRANSPORT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG | GNUNET_ERROR_TYPE_BULK,
              "Refreshed my `%s', new size is %d\n", "HELLO",
              GNUNET_HELLO_size (our_hello));
#endif
  GNUNET_STATISTICS_update (GST_stats, gettext_noop ("# refreshed my HELLO"), 1,
                            GNUNET_NO);
  if (NULL != hello_cb)
    hello_cb (hello_cb_cls, GST_hello_get ());
  GNUNET_PEERINFO_add_peer (GST_peerinfo, our_hello);
  hello_task =
      GNUNET_SCHEDULER_add_delayed (HELLO_REFRESH_PERIOD, &refresh_hello_task,
                                    NULL);

}


/**
 * Schedule task to refresh hello (unless such a
 * task exists already).
 */
static void
refresh_hello ()
{
  if (hello_task != GNUNET_SCHEDULER_NO_TASK)
    GNUNET_SCHEDULER_cancel (hello_task);
  hello_task = GNUNET_SCHEDULER_add_now (&refresh_hello_task, NULL);
}


/**
 * Initialize the HELLO module.
 *
 * @param cb function to call whenever our HELLO changes
 * @param cb_cls closure for cb
 */
void
GST_hello_start (GST_HelloCallback cb, void *cb_cls)
{
  hello_cb = cb;
  hello_cb_cls = cb_cls;
  our_hello = GNUNET_HELLO_create (&GST_my_public_key, NULL, NULL);
  refresh_hello ();
}


/**
 * Shutdown the HELLO module.
 */
void
GST_hello_stop ()
{
  hello_cb = NULL;
  hello_cb_cls = NULL;
  if (GNUNET_SCHEDULER_NO_TASK != hello_task)
  {
    GNUNET_SCHEDULER_cancel (hello_task);
    hello_task = GNUNET_SCHEDULER_NO_TASK;
  }
  if (NULL != our_hello)
  {
    GNUNET_free (our_hello);
    our_hello = NULL;
  }
}


/**
 * Obtain this peers HELLO message.
 *
 * @return our HELLO message
 */
const struct GNUNET_MessageHeader *
GST_hello_get ()
{
  return (struct GNUNET_MessageHeader *) our_hello;
}


/**
 * Add or remove an address from this peer's HELLO message.
 *
 * @param addremove GNUNET_YES to add, GNUNET_NO to remove
 * @param address address to add or remove
 */
void
GST_hello_modify_addresses (int addremove,
			    const struct GNUNET_HELLO_Address *address)
{
  struct OwnAddressList *al;

#if DEBUG_TRANSPORT
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
              (add_remove ==
               GNUNET_YES) ? "Adding `%s':%s to the set of our addresses\n" :
              "Removing `%s':%s from the set of our addresses\n",
              GST_plugins_a2s (address), p->short_name);
#endif
  GNUNET_assert (address != NULL);
  if (GNUNET_NO == addremove)
  {
    for (al = oal_head; al != NULL; al = al->next)
      if (0 ==
	  GNUNET_HELLO_address_cmp (address,
				    al->address))
	{
        GNUNET_CONTAINER_DLL_remove (oal_head, oal_tail, al);
        GNUNET_HELLO_address_free (al->address);
        GNUNET_free (al);
        refresh_hello ();
        return;
      }
    /* address to be removed not found!? */
    GNUNET_break (0);
    return;
  }
  al = GNUNET_malloc (sizeof (struct OwnAddressList));
  GNUNET_CONTAINER_DLL_insert (oal_head, oal_tail, al);
  al->address = GNUNET_HELLO_address_copy (address);
  refresh_hello ();
}


/**
 * Test if a particular address is one of ours.
 *
 * @param address address to test
 * @param sig location where to cache PONG signatures for this address [set]
 * @param sig_expiration how long until the current 'sig' expires?
 *            (ZERO if sig was never created) [set]
 * @return GNUNET_YES if this is one of our addresses,
 *         GNUNET_NO if not
 */
int
GST_hello_test_address (const struct GNUNET_HELLO_Address *address,
                        struct GNUNET_CRYPTO_RsaSignature **sig,
                        struct GNUNET_TIME_Absolute **sig_expiration)
{
  struct OwnAddressList *al;

  for (al = oal_head; al != NULL; al = al->next)
    if (0 == GNUNET_HELLO_address_cmp (address,
				       al->address))
    {
      *sig = &al->pong_signature;
      *sig_expiration = &al->pong_sig_expires;
      return GNUNET_YES;
    }
  *sig = NULL;
  *sig_expiration = NULL;
  return GNUNET_NO;
}


/* end of file gnunet-service-transport_hello.c */