summaryrefslogtreecommitdiff
path: root/src/transport/transport_api_monitor_peers.c
blob: ce4d9ae9e675d4817b9e85e14a89bceb9284b60d (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
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
/*
     This file is part of GNUnet.
     Copyright (C) 2009-2014, 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 transport/transport_api_monitor_peers.c
 * @brief montoring api for transport peer status
 *
 * This api provides the ability to query the transport service about
 * the connection status of a specific or all peers.
 *
 * Calls back with information about peer(s) including address used, state and
 * state timeout for peer requests.
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_arm_service.h"
#include "gnunet_hello_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_transport_service.h"
#include "transport.h"

/**
 * Context for iterating validation entries.
 */
struct GNUNET_TRANSPORT_PeerMonitoringContext
{
  /**
   * Function to call with the binary address.
   */
  GNUNET_TRANSPORT_PeerIterateCallback cb;

  /**
   * Closure for @e cb.
   */
  void *cb_cls;

  /**
   * Connection to the service.
   */
  struct GNUNET_MQ_Handle *mq;

  /**
   * Configuration we use.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Backoff for reconnect.
   */
  struct GNUNET_TIME_Relative backoff;

  /**
   * Task ID for reconnect.
   */
  struct GNUNET_SCHEDULER_Task *reconnect_task;

  /**
   * Identity of the peer to monitor.
   */
  struct GNUNET_PeerIdentity peer;

  /**
   * Was this a one-shot request?
   */
  int one_shot;
};


/**
 * Check if a state is defined as connected
 *
 * @param state the state value
 * @return #GNUNET_YES or #GNUNET_NO
 */
int
GNUNET_TRANSPORT_is_connected (enum GNUNET_TRANSPORT_PeerState state)
{
  switch (state)
  {
  case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
  case GNUNET_TRANSPORT_PS_INIT_ATS:
  case GNUNET_TRANSPORT_PS_SYN_SENT:
  case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
  case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
    return GNUNET_NO;
  case GNUNET_TRANSPORT_PS_CONNECTED:
  case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
  case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
  case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
    return GNUNET_YES;
  case GNUNET_TRANSPORT_PS_DISCONNECT:
  case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
    return GNUNET_NO;
  default:
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                "Unhandled state `%s'\n",
                GNUNET_TRANSPORT_ps2s (state));
    GNUNET_break (0);
    break;
  }
  return GNUNET_SYSERR;
}


/**
 * Convert peer state to human-readable string.
 *
 * @param state the state value
 * @return corresponding string
 */
const char *
GNUNET_TRANSPORT_ps2s (enum GNUNET_TRANSPORT_PeerState state)
{
  switch (state)
  {
  case GNUNET_TRANSPORT_PS_NOT_CONNECTED:
    return "S_NOT_CONNECTED";
  case GNUNET_TRANSPORT_PS_INIT_ATS:
    return "S_INIT_ATS";
  case GNUNET_TRANSPORT_PS_SYN_SENT:
    return "S_SYN_SENT";
  case GNUNET_TRANSPORT_PS_SYN_RECV_ATS:
    return "S_SYN_RECV_ATS";
  case GNUNET_TRANSPORT_PS_SYN_RECV_ACK:
    return "S_SYN_RECV_ACK";
  case GNUNET_TRANSPORT_PS_CONNECTED:
    return "S_CONNECTED";
  case GNUNET_TRANSPORT_PS_RECONNECT_ATS:
    return "S_RECONNECT_ATS";
  case GNUNET_TRANSPORT_PS_RECONNECT_SENT:
    return "S_RECONNECT_SENT";
  case GNUNET_TRANSPORT_PS_SWITCH_SYN_SENT:
    return "S_SWITCH_SYN_SENT";
  case GNUNET_TRANSPORT_PS_DISCONNECT:
    return "S_DISCONNECT";
  case GNUNET_TRANSPORT_PS_DISCONNECT_FINISHED:
    return "S_DISCONNECT_FINISHED";
  default:
    GNUNET_break (0);
    return "UNDEFINED";
  }
}


/**
 * Task run to re-establish the connection.
 *
 * @param cls our `struct GNUNET_TRANSPORT_PeerMonitoringContext *`
 */
static void
do_peer_connect (void *cls);


/**
 * Cut the existing connection and reconnect.
 *
 * @param pal_ctx our context
 */
static void
reconnect_peer_ctx (struct GNUNET_TRANSPORT_PeerMonitoringContext *pal_ctx)
{
  GNUNET_assert (GNUNET_NO == pal_ctx->one_shot);
  GNUNET_MQ_destroy (pal_ctx->mq);
  pal_ctx->mq = NULL;
  pal_ctx->cb (pal_ctx->cb_cls,
               NULL,
               NULL,
               GNUNET_TRANSPORT_PS_NOT_CONNECTED,
               GNUNET_TIME_UNIT_ZERO_ABS);
  pal_ctx->backoff = GNUNET_TIME_STD_BACKOFF (pal_ctx->backoff);
  pal_ctx->reconnect_task = GNUNET_SCHEDULER_add_delayed (pal_ctx->backoff,
							  &do_peer_connect,
							  pal_ctx);
}


/**
 * Function called with responses from the service.
 *
 * @param cls our `struct GNUNET_TRANSPORT_PeerMonitoringContext *`
 * @param msg message from service
 */
static void
handle_response_end (void *cls,
                     const struct GNUNET_MessageHeader *msg)
{
  struct GNUNET_TRANSPORT_PeerMonitoringContext *pal_ctx = cls;

  if (pal_ctx->one_shot)
  {
    /* iteration finished */
    pal_ctx->cb (pal_ctx->cb_cls,
                 NULL,
                 NULL,
                 GNUNET_TRANSPORT_PS_NOT_CONNECTED,
                 GNUNET_TIME_UNIT_ZERO_ABS);
    GNUNET_TRANSPORT_monitor_peers_cancel (pal_ctx);
    return;
  }
  /* not quite what we expected, reconnect */
  GNUNET_break (0);
  reconnect_peer_ctx (pal_ctx);
}


/**
 * Function called to check responses from the service.
 *
 * @param cls our `struct GNUNET_TRANSPORT_PeerMonitoringContext *`
 * @param pir_msg  message with the human-readable address
 * @return #GNUNET_OK if @a pir_msg is well-formed
 */
static int
check_response (void *cls,
                const struct PeerIterateResponseMessage *pir_msg)
{
  uint16_t size = ntohs (pir_msg->header.size) - sizeof (*pir_msg);
  size_t alen = ntohl (pir_msg->addrlen);
  size_t tlen = ntohl (pir_msg->pluginlen);
  const char *addr;
  const char *transport_name;

  if (size != tlen + alen)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if ( (0 == tlen) && (0 == alen) )
    return GNUNET_OK;
  if (0 == tlen)
  {
    GNUNET_break (0); /* This must not happen: address without plugin */
    return GNUNET_SYSERR;
  }
  addr = (const char *) &pir_msg[1];
  transport_name = &addr[alen];
  if (transport_name[tlen - 1] != '\0')
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}


/**
 * Function called with responses from the service.
 *
 * @param cls our `struct GNUNET_TRANSPORT_PeerMonitoringContext *`
 * @param msg  message with the human-readable address
 */
static void
handle_response (void *cls,
                 const struct PeerIterateResponseMessage *pir_msg)
{
  struct GNUNET_TRANSPORT_PeerMonitoringContext *pal_ctx = cls;
  struct GNUNET_HELLO_Address *address;
  size_t alen = ntohl (pir_msg->addrlen);
  size_t tlen = ntohl (pir_msg->pluginlen);
  const char *addr;
  const char *transport_name;

  if ( (0 == tlen) &&
       (0 == alen) )
  {
    /* No address available */
    pal_ctx->cb (pal_ctx->cb_cls,
                 &pir_msg->peer,
                 NULL,
                 ntohl(pir_msg->state),
                 GNUNET_TIME_absolute_ntoh (pir_msg->state_timeout));
    return;
  }
  addr = (const char *) &pir_msg[1];
  transport_name = &addr[alen];

  /* notify client */
  address = GNUNET_HELLO_address_allocate (&pir_msg->peer,
                                           transport_name,
                                           addr,
                                           alen,
                                           ntohl (pir_msg->local_address_info));
  pal_ctx->cb (pal_ctx->cb_cls,
               &pir_msg->peer,
               address,
               ntohl (pir_msg->state),
               GNUNET_TIME_absolute_ntoh (pir_msg->state_timeout));
  GNUNET_HELLO_address_free (address);
}



/**
 * 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_TRANSPORT_PeerMonitoringContext *`
 * @param error error code
 */
static void
mq_error_handler (void *cls,
                  enum GNUNET_MQ_Error error)
{
  struct GNUNET_TRANSPORT_PeerMonitoringContext *pal_ctx = cls;

  if (pal_ctx->one_shot)
  {
    /* Disconnect */
    pal_ctx->cb (pal_ctx->cb_cls,
                 NULL,
                 NULL,
                 GNUNET_TRANSPORT_PS_NOT_CONNECTED,
                 GNUNET_TIME_UNIT_ZERO_ABS);
    GNUNET_TRANSPORT_monitor_peers_cancel (pal_ctx);
    return;
  }
  reconnect_peer_ctx (pal_ctx);
}


/**
 * Task run to re-establish the connection.
 *
 * @param cls our `struct GNUNET_TRANSPORT_PeerMonitoringContext *`
 */
static void
do_peer_connect (void *cls)
{
  struct GNUNET_TRANSPORT_PeerMonitoringContext *pal_ctx = cls;
  struct GNUNET_MQ_MessageHandler handlers[] = {
    GNUNET_MQ_hd_var_size (response,
                           GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_PEER_RESPONSE,
                           struct PeerIterateResponseMessage,
                           pal_ctx),
    GNUNET_MQ_hd_fixed_size (response_end,
                             GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_PEER_RESPONSE_END,
                             struct GNUNET_MessageHeader,
                             pal_ctx),
    GNUNET_MQ_handler_end ()
  };
  struct PeerMonitorMessage *msg;
  struct GNUNET_MQ_Envelope *env;

  pal_ctx->reconnect_task = NULL;
  pal_ctx->mq = GNUNET_CLIENT_connect (pal_ctx->cfg,
                                       "transport",
                                       handlers,
                                       &mq_error_handler,
                                       pal_ctx);
  if (NULL == pal_ctx->mq)
    return;
  env = GNUNET_MQ_msg (msg,
                       GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_PEER_REQUEST);
  msg->one_shot = htonl (pal_ctx->one_shot);
  msg->peer = pal_ctx->peer;
  GNUNET_MQ_send (pal_ctx->mq,
                  env);
}


/**
 * Return information about a specific peer or all peers currently known to
 * transport service once or in monitoring mode. To obtain information about
 * a specific peer, a peer identity can be passed. To obtain information about
 * all peers currently known to transport service, NULL can be passed as peer
 * identity.
 *
 * For each peer, the callback is called with information about the address used
 * to communicate with this peer, the state this peer is currently in and the
 * the current timeout for this state.
 *
 * Upon completion, the 'GNUNET_TRANSPORT_PeerIterateCallback' is called one
 * more time with 'NULL'. After this, the operation must no longer be
 * explicitly canceled.
 *
 * The #GNUNET_TRANSPORT_monitor_peers_cancel call MUST not be called in the
 * the peer_callback!
 *
 * @param cfg configuration to use
 * @param peer a specific peer identity to obtain information for,
 *      NULL for all peers
 * @param one_shot #GNUNET_YES to return the current state and then end (with NULL+NULL),
 *                 #GNUNET_NO to monitor peers continuously
 * @param peer_callback function to call with the results
 * @param peer_callback_cls closure for @a peer_address_callback
 */
struct GNUNET_TRANSPORT_PeerMonitoringContext *
GNUNET_TRANSPORT_monitor_peers (const struct GNUNET_CONFIGURATION_Handle *cfg,
                                const struct GNUNET_PeerIdentity *peer,
                                int one_shot,
                                GNUNET_TRANSPORT_PeerIterateCallback peer_callback,
                                void *peer_callback_cls)
{
  struct GNUNET_TRANSPORT_PeerMonitoringContext *pal_ctx
    = GNUNET_new (struct GNUNET_TRANSPORT_PeerMonitoringContext);

  pal_ctx->cb = peer_callback;
  pal_ctx->cb_cls = peer_callback_cls;
  pal_ctx->cfg = cfg;
  if (NULL != peer)
    pal_ctx->peer = *peer;
  pal_ctx->one_shot = one_shot;
  do_peer_connect (pal_ctx);
  if (NULL == pal_ctx->mq)
  {
    GNUNET_free (pal_ctx);
    return NULL;
  }
  return pal_ctx;
}


/**
 * Cancel request to monitor peers
 *
 * @param pic handle for the request to cancel
 */
void
GNUNET_TRANSPORT_monitor_peers_cancel (struct GNUNET_TRANSPORT_PeerMonitoringContext *pic)
{
  if (NULL != pic->mq)
  {
    GNUNET_MQ_destroy (pic->mq);
    pic->mq = NULL;
  }
  if (NULL != pic->reconnect_task)
  {
    GNUNET_SCHEDULER_cancel (pic->reconnect_task);
    pic->reconnect_task = NULL;
  }
  GNUNET_free (pic);
}


/* end of transport_api_monitor_peers.c */