aboutsummaryrefslogtreecommitdiff
path: root/src/transport/transport_api2_monitor.c
blob: 97812ff89909ae695253647e18b3040415f5f8e0 (plain) (blame)
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
/*
     This file is part of GNUnet.
     Copyright (C) 2018 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_api2_monitor.c
 * @brief implementation of the gnunet_transport_monitor_service.h API
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_protocols.h"
#include "gnunet_transport_monitor_service.h"
#include "transport.h"


/**
 * Opaque handle to the transport service for monitors.
 */
struct GNUNET_TRANSPORT_MonitorContext
{
  /**
   * Our configuration.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Queue to talk to the transport service.
   */
  struct GNUNET_MQ_Handle *mq;

  /**
   * Peer we monitor, all zeros for "all"
   */
  struct GNUNET_PeerIdentity peer;

  /**
   * #GNUNET_YES to return the current state and then end.
   */
  int one_shot;

  /**
   * Function to call with monitor data.
   */
  GNUNET_TRANSPORT_MonitorCallback cb;

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


/**
 * (re)connect our monitor to the transport service
 *
 * @param mc handle to reconnect
 */
static void
reconnect (struct GNUNET_TRANSPORT_MonitorContext *mc);


/**
 * Send message to the transport service about our montoring
 * desire.
 *
 * @param ai address to delete
 */
static void
send_start_monitor (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  struct GNUNET_MQ_Envelope *env;
  struct GNUNET_TRANSPORT_MonitorStart *smm;

  if (NULL == mc->mq)
    return;
  env = GNUNET_MQ_msg (smm, GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_START);
  smm->one_shot = htonl ((uint32_t) mc->one_shot);
  smm->peer = mc->peer;
  GNUNET_MQ_send (mc->mq, env);
}


/**
 * Disconnect from the transport service.
 *
 * @param mc service to disconnect from
 */
static void
disconnect (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  if (NULL == mc->mq)
    return;
  GNUNET_MQ_destroy (mc->mq);
  mc->mq = NULL;
}


/**
 * Function called on MQ errors. Reconnects to the service.
 *
 * @param cls our `struct GNUNET_TRANSPORT_MonitorContext *`
 * @param error what error happened?
 */
static void
error_handler (void *cls, enum GNUNET_MQ_Error error)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc = cls;

  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              "MQ failure %d, reconnecting to transport service.\n",
              error);
  disconnect (mc);
  /* TODO: maybe do this with exponential backoff/delay */
  reconnect (mc);
}


/**
 * Transport service sends us information about what is going on.
 * Check if @a md is well-formed.
 *
 * @param cls our `struct GNUNET_TRANSPORT_MonitorContext *`
 * @param md the monitor data we got
 * @return #GNUNET_OK if @a smt is well-formed
 */
static int
check_monitor_data (void *cls, const struct GNUNET_TRANSPORT_MonitorData *md)
{
  (void) cls;
  GNUNET_MQ_check_zero_termination (md);
  return GNUNET_OK;
}


/**
 * Transport service sends us information about what is going on.
 *
 * @param cls our `struct GNUNET_TRANSPORT_MonitorContext *`
 * @param md monitor data
 */
static void
handle_monitor_data (void *cls, const struct GNUNET_TRANSPORT_MonitorData *md)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc = cls;
  struct GNUNET_TRANSPORT_MonitorInformation mi;

  mi.address = (const char *) &md[1];
  mi.nt = (enum GNUNET_NetworkType) ntohl (md->nt);
  mi.cs = (enum GNUNET_TRANSPORT_ConnectionStatus) ntohl (md->cs);
  mi.num_msg_pending = ntohl (md->num_msg_pending);
  mi.num_bytes_pending = ntohl (md->num_bytes_pending);
  mi.last_validation = GNUNET_TIME_absolute_ntoh (md->last_validation);
  mi.valid_until = GNUNET_TIME_absolute_ntoh (md->valid_until);
  mi.next_validation = GNUNET_TIME_absolute_ntoh (md->next_validation);
  mi.rtt = GNUNET_TIME_relative_ntoh (md->rtt);
  mc->cb (mc->cb_cls, &md->peer, &mi);
}


/**
 * One shot was requested, and transport service is done.
 *
 * @param cls our `struct GNUNET_TRANSPORT_MonitorContext *`
 * @param me end message
 */
static void
handle_monitor_end (void *cls, const struct GNUNET_MessageHeader *me)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc = cls;

  if (GNUNET_YES != mc->one_shot)
  {
    GNUNET_break (0);
    disconnect (mc);
    reconnect (mc);
    return;
  }
  mc->cb (mc->cb_cls, NULL, NULL);
  GNUNET_TRANSPORT_monitor_cancel (mc);
}


/**
 * (re)connect our monitor to the transport service
 *
 * @param mc handle to reconnect
 */
static void
reconnect (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  struct GNUNET_MQ_MessageHandler handlers[] =
    {GNUNET_MQ_hd_var_size (monitor_data,
                            GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_DATA,
                            struct GNUNET_TRANSPORT_MonitorData,
                            mc),
     GNUNET_MQ_hd_fixed_size (monitor_end,
                              GNUNET_MESSAGE_TYPE_TRANSPORT_MONITOR_END,
                              struct GNUNET_MessageHeader,
                              mc),
     GNUNET_MQ_handler_end ()};

  mc->mq =
    GNUNET_CLIENT_connect (mc->cfg, "transport", handlers, &error_handler, mc);
  if (NULL == mc->mq)
    return;
  send_start_monitor (mc);
}


/**
 * 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 cb function to call with the results
 * @param cb_cls closure for @a mc
 */
struct GNUNET_TRANSPORT_MonitorContext *
GNUNET_TRANSPORT_monitor (const struct GNUNET_CONFIGURATION_Handle *cfg,
                          const struct GNUNET_PeerIdentity *peer,
                          int one_shot,
                          GNUNET_TRANSPORT_MonitorCallback cb,
                          void *cb_cls)
{
  struct GNUNET_TRANSPORT_MonitorContext *mc;

  mc = GNUNET_new (struct GNUNET_TRANSPORT_MonitorContext);
  mc->cfg = cfg;
  if (NULL != peer)
    mc->peer = *peer;
  mc->one_shot = one_shot;
  mc->cb = cb;
  mc->cb_cls = cb_cls;
  reconnect (mc);
  if (NULL == mc->mq)
  {
    GNUNET_free (mc);
    return NULL;
  }
  return mc;
}


/**
 * Cancel request to monitor peers
 *
 * @param pmc handle for the request to cancel
 */
void
GNUNET_TRANSPORT_monitor_cancel (struct GNUNET_TRANSPORT_MonitorContext *mc)
{
  disconnect (mc);
  GNUNET_free (mc);
}

/* end of transport_api2_monitor.c */