summaryrefslogtreecommitdiff
path: root/src/ats/ats_api_performance.c
blob: c9f9a0b38fb3d318b86e3cf47f0d45366ab3f0eb (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
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
/*
     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 ats/ats_api_performance.c
 * @brief automatic transport selection and outbound bandwidth determination
 * @author Christian Grothoff
 * @author Matthias Wachs
  */
#include "platform.h"
#include "gnunet_ats_service.h"
#include "ats.h"


/**
 * Message in linked list we should send to the ATS service.  The
 * actual binary message follows this struct.
 */
struct PendingMessage
{

  /**
   * Kept in a DLL.
   */
  struct PendingMessage *next;

  /**
   * Kept in a DLL.
   */
  struct PendingMessage *prev;

  /**
   * Size of the message.
   */
  size_t size;

  /**
   * Is this the 'ATS_START' message?
   */
  int is_init;
};


/**
 * Linked list of pending reservations.
 */
struct GNUNET_ATS_ReservationContext
{

  /**
   * Kept in a DLL.
   */
  struct GNUNET_ATS_ReservationContext *next;

  /**
   * Kept in a DLL.
   */
  struct GNUNET_ATS_ReservationContext *prev;

  /**
   * Target peer.
   */
  struct GNUNET_PeerIdentity peer;

  /**
   * Desired reservation
   */
  int32_t size;

  /**
   * Function to call on result.
   */
  GNUNET_ATS_ReservationCallback rcb;

  /**
   * Closure for 'rcb'
   */
  void *rcb_cls;

  /**
   * Do we need to undo this reservation if it succeeded?  Set to
   * GNUNET_YES if a reservation is cancelled.  (at that point, 'info'
   * is also set to NULL; however, info will ALSO be NULL for the
   * reservation context that is created to undo the original request,
   * so 'info' being NULL cannot be used to check if undo is
   * required).
   */
  int undo;
};


/**
 * ATS Handle to obtain and/or modify performance information.
 */
struct GNUNET_ATS_PerformanceHandle
{

  /**
   * Our configuration.
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Callback to invoke on performance changes.
   */
  GNUNET_ATS_PeerInformationCallback infocb;

  /**
   * Closure for 'infocb'.
   */
  void *infocb_cls;

  /**
   * Connection to ATS service.
   */
  struct GNUNET_CLIENT_Connection *client;

  /**
   * Head of list of messages for the ATS service.
   */
  struct PendingMessage *pending_head;

  /**
   * Tail of list of messages for the ATS service
   */
  struct PendingMessage *pending_tail;

  /**
   * Head of linked list of pending reservation requests.
   */
  struct GNUNET_ATS_ReservationContext *reservation_head;

  /**
   * Tail of linked list of pending reservation requests.
   */
  struct GNUNET_ATS_ReservationContext *reservation_tail;

  /**
   * Current request for transmission to ATS.
   */
  struct GNUNET_CLIENT_TransmitHandle *th;

  /**
   * Task to trigger reconnect.
   */
  GNUNET_SCHEDULER_TaskIdentifier task;

};


/**
 * Re-establish the connection to the ATS service.
 *
 * @param ph handle to use to re-connect.
 */
static void
reconnect (struct GNUNET_ATS_PerformanceHandle *ph);


/**
 * Re-establish the connection to the ATS service.
 *
 * @param cls handle to use to re-connect.
 * @param tc scheduler context
 */
static void
reconnect_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct GNUNET_ATS_PerformanceHandle *ph = cls;

  ph->task = GNUNET_SCHEDULER_NO_TASK;
  reconnect (ph);
}


/**
 * Transmit messages from the message queue to the service
 * (if there are any, and if we are not already trying).
 *
 * @param ph handle to use
 */
static void
do_transmit (struct GNUNET_ATS_PerformanceHandle *ph);


/**
 * We can now transmit a message to ATS. Do it.
 *
 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
 * @param size number of bytes we can transmit to ATS
 * @param buf where to copy the messages
 * @return number of bytes copied into buf
 */
static size_t
transmit_message_to_ats (void *cls, size_t size, void *buf)
{
  struct GNUNET_ATS_PerformanceHandle *ph = cls;
  struct PendingMessage *p;
  size_t ret;
  char *cbuf;

  ph->th = NULL;
  ret = 0;
  cbuf = buf;
  while ((NULL != (p = ph->pending_head)) && (p->size <= size))
  {
    memcpy (&cbuf[ret], &p[1], p->size);
    ret += p->size;
    size -= p->size;
    GNUNET_CONTAINER_DLL_remove (ph->pending_head, ph->pending_tail, p);
    GNUNET_free (p);
  }
  do_transmit (ph);
  return ret;
}


/**
 * Transmit messages from the message queue to the service
 * (if there are any, and if we are not already trying).
 *
 * @param ph handle to use
 */
static void
do_transmit (struct GNUNET_ATS_PerformanceHandle *ph)
{
  struct PendingMessage *p;

  if (NULL != ph->th)
    return;
  if (NULL == (p = ph->pending_head))
    return;
  if (NULL == ph->client)
    return;                     /* currently reconnecting */
  ph->th =
      GNUNET_CLIENT_notify_transmit_ready (ph->client, p->size,
                                           GNUNET_TIME_UNIT_FOREVER_REL,
                                           GNUNET_YES, &transmit_message_to_ats,
                                           ph);
}


/**
 * We received a peer information message.  Validate and process it.
 *
 * @param ph our context with the callback
 * @param msg the message
 * @return GNUNET_OK if the message was well-formed
 */
static int
process_pi_message (struct GNUNET_ATS_PerformanceHandle *ph,
                    const struct GNUNET_MessageHeader *msg)
{
  const struct PeerInformationMessage *pi;
  const struct GNUNET_ATS_Information *atsi;
  const char *plugin_address;
  const char *plugin_name;
  struct GNUNET_HELLO_Address address;
  uint16_t plugin_address_length;
  uint16_t plugin_name_length;
  uint32_t ats_count;

  if (ph->infocb == NULL)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  if (ntohs (msg->size) < sizeof (struct PeerInformationMessage))
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  pi = (const struct PeerInformationMessage *) msg;
  ats_count = ntohl (pi->ats_count);
  plugin_address_length = ntohs (pi->address_length);
  plugin_name_length = ntohs (pi->plugin_name_length);
  atsi = (const struct GNUNET_ATS_Information *) &pi[1];
  plugin_address = (const char *) &atsi[ats_count];
  plugin_name = &plugin_address[plugin_address_length];
  if ((plugin_address_length + plugin_name_length +
       ats_count * sizeof (struct GNUNET_ATS_Information) +
       sizeof (struct PeerInformationMessage) != ntohs (msg->size)) ||
      (ats_count >
       GNUNET_SERVER_MAX_MESSAGE_SIZE / sizeof (struct GNUNET_ATS_Information))
      || (plugin_name[plugin_name_length - 1] != '\0'))
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  address.peer = pi->peer;
  address.address = plugin_address;
  address.address_length = plugin_address_length;
  address.transport_name = plugin_name;
  ph->infocb (ph->infocb_cls, &address, pi->bandwidth_out, pi->bandwidth_in,
              atsi, ats_count);
  return GNUNET_OK;
}


/**
 * We received a reservation result message.  Validate and process it.
 *
 * @param ph our context with the callback
 * @param msg the message
 * @return GNUNET_OK if the message was well-formed
 */
static int
process_rr_message (struct GNUNET_ATS_PerformanceHandle *ph,
                    const struct GNUNET_MessageHeader *msg)
{
  const struct ReservationResultMessage *rr;
  struct GNUNET_ATS_ReservationContext *rc;
  int32_t amount;

  if (ntohs (msg->size) < sizeof (struct ReservationResultMessage))
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  rr = (const struct ReservationResultMessage *) msg;
  amount = ntohl (rr->amount);
  rc = ph->reservation_head;
  if (0 != memcmp (&rr->peer, &rc->peer, sizeof (struct GNUNET_PeerIdentity)))
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  GNUNET_CONTAINER_DLL_remove (ph->reservation_head, ph->reservation_tail, rc);
  if ((amount == 0) || (rc->rcb != NULL))
  {
    /* tell client if not cancelled */
    if (rc->rcb != NULL)
      rc->rcb (rc->rcb_cls, &rr->peer, amount,
               GNUNET_TIME_relative_ntoh (rr->res_delay));
    GNUNET_free (rc);
    return GNUNET_OK;
  }
  /* amount non-zero, but client cancelled, consider undo! */
  if (GNUNET_YES != rc->undo)
  {
    GNUNET_free (rc);
    return GNUNET_OK;           /* do not try to undo failed undos or negative amounts */
  }
  GNUNET_free (rc);
  (void) GNUNET_ATS_reserve_bandwidth (ph, &rr->peer, -amount, NULL, NULL);
  return GNUNET_OK;
}


/**
 * Type of a function to call when we receive a message
 * from the service.
 *
 * @param cls the 'struct GNUNET_ATS_SchedulingHandle'
 * @param msg message received, NULL on timeout or fatal error
 */
static void
process_ats_message (void *cls, const struct GNUNET_MessageHeader *msg)
{
  struct GNUNET_ATS_PerformanceHandle *ph = cls;

  if (NULL == msg)
    goto reconnect;
  switch (ntohs (msg->type))
  {
  case GNUNET_MESSAGE_TYPE_ATS_PEER_INFORMATION:
    if (GNUNET_OK != process_pi_message (ph, msg))
      goto reconnect;
    break;
  case GNUNET_MESSAGE_TYPE_ATS_RESERVATION_RESULT:
    if (GNUNET_OK != process_rr_message (ph, msg))
      goto reconnect;
    break;
  default:
    GNUNET_break (0);
    goto reconnect;
    return;
  }
  GNUNET_CLIENT_receive (ph->client, &process_ats_message, ph,
                         GNUNET_TIME_UNIT_FOREVER_REL);
  return;
reconnect:
  GNUNET_CLIENT_disconnect (ph->client, GNUNET_NO);
  ph->client = NULL;
  ph->task =
      GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_SECONDS, &reconnect_task,
                                    ph);
}


/**
 * Re-establish the connection to the ATS service.
 *
 * @param ph handle to use to re-connect.
 */
static void
reconnect (struct GNUNET_ATS_PerformanceHandle *ph)
{
  struct PendingMessage *p;
  struct ClientStartMessage *init;

  GNUNET_assert (NULL == ph->client);
  ph->client = GNUNET_CLIENT_connect ("ats", ph->cfg);
  GNUNET_assert (NULL != ph->client);
  GNUNET_CLIENT_receive (ph->client, &process_ats_message, ph,
                         GNUNET_TIME_UNIT_FOREVER_REL);
  if ((NULL == (p = ph->pending_head)) || (GNUNET_YES != p->is_init))
  {
    p = GNUNET_malloc (sizeof (struct PendingMessage) +
                       sizeof (struct ClientStartMessage));
    p->size = sizeof (struct ClientStartMessage);
    p->is_init = GNUNET_YES;
    init = (struct ClientStartMessage *) &p[1];
    init->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_START);
    init->header.size = htons (sizeof (struct ClientStartMessage));
    init->start_flag =
        htonl ((ph->infocb ==
                NULL) ? START_FLAG_PERFORMANCE_NO_PIC :
               START_FLAG_PERFORMANCE_WITH_PIC);
    GNUNET_CONTAINER_DLL_insert (ph->pending_head, ph->pending_tail, p);
  }
  do_transmit (ph);
}



/**
 * Get handle to access performance API of the ATS subsystem.
 *
 * @param cfg configuration to use
 * @param infocb function to call on allocation changes, can be NULL
 * @param infocb_cls closure for infocb
 * @return ats performance context
 */
struct GNUNET_ATS_PerformanceHandle *
GNUNET_ATS_performance_init (const struct GNUNET_CONFIGURATION_Handle *cfg,
                             GNUNET_ATS_PeerInformationCallback infocb,
                             void *infocb_cls)
{
  struct GNUNET_ATS_PerformanceHandle *ph;

  ph = GNUNET_malloc (sizeof (struct GNUNET_ATS_PerformanceHandle));
  ph->cfg = cfg;
  ph->infocb = infocb;
  ph->infocb_cls = infocb_cls;
  reconnect (ph);
  return ph;
}


/**
 * Client is done using the ATS performance subsystem, release resources.
 *
 * @param ph handle
 */
void
GNUNET_ATS_performance_done (struct GNUNET_ATS_PerformanceHandle *ph)
{
  struct PendingMessage *p;
  struct GNUNET_ATS_ReservationContext *rc;

  while (NULL != (p = ph->pending_head))
  {
    GNUNET_CONTAINER_DLL_remove (ph->pending_head, ph->pending_tail, p);
    GNUNET_free (p);
  }
  while (NULL != (rc = ph->reservation_head))
  {
    GNUNET_CONTAINER_DLL_remove (ph->reservation_head, ph->reservation_tail,
                                 rc);
    GNUNET_break (NULL == rc->rcb);
    GNUNET_free (rc);
  }
  if (GNUNET_SCHEDULER_NO_TASK != ph->task)
  {
    GNUNET_SCHEDULER_cancel (ph->task);
    ph->task = GNUNET_SCHEDULER_NO_TASK;
  }
  if (NULL != ph->client)
  {
    GNUNET_CLIENT_disconnect (ph->client, GNUNET_NO);
    ph->client = NULL;
  }
  GNUNET_free (ph);
}


/**
 * Reserve inbound bandwidth from the given peer.  ATS will look at
 * the current amount of traffic we receive from the peer and ensure
 * that the peer could add 'amount' of data to its stream.
 *
 * @param ph performance handle
 * @param peer identifies the peer
 * @param amount reserve N bytes for receiving, negative
 *                amounts can be used to undo a (recent) reservation;
 * @param rcb function to call with the resulting reservation information
 * @param rcb_cls closure for info
 * @return NULL on error
 * @deprecated will be replaced soon
 */
struct GNUNET_ATS_ReservationContext *
GNUNET_ATS_reserve_bandwidth (struct GNUNET_ATS_PerformanceHandle *ph,
                              const struct GNUNET_PeerIdentity *peer,
                              int32_t amount,
                              GNUNET_ATS_ReservationCallback rcb, void *rcb_cls)
{
  struct GNUNET_ATS_ReservationContext *rc;
  struct PendingMessage *p;
  struct ReservationRequestMessage *m;

  rc = GNUNET_malloc (sizeof (struct GNUNET_ATS_ReservationContext));
  rc->size = amount;
  rc->peer = *peer;
  rc->rcb = rcb;
  rc->rcb_cls = rcb_cls;
  if ((rcb != NULL) && (amount > 0))
    rc->undo = GNUNET_YES;
  GNUNET_CONTAINER_DLL_insert_tail (ph->reservation_head, ph->reservation_tail,
                                    rc);

  p = GNUNET_malloc (sizeof (struct PendingMessage) +
                     sizeof (struct ReservationRequestMessage));
  p->size = sizeof (struct ReservationRequestMessage);
  p->is_init = GNUNET_NO;
  m = (struct ReservationRequestMessage *) &p[1];
  m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_RESERVATION_REQUEST);
  m->header.size = htons (sizeof (struct ReservationRequestMessage));
  m->amount = htonl (amount);
  m->peer = *peer;
  GNUNET_CONTAINER_DLL_insert_tail (ph->pending_head, ph->pending_tail, p);
  do_transmit (ph);
  return rc;
}


/**
 * Cancel request for reserving bandwidth.
 *
 * @param rc context returned by the original GNUNET_ATS_reserve_bandwidth call
 */
void
GNUNET_ATS_reserve_bandwidth_cancel (struct GNUNET_ATS_ReservationContext *rc)
{
  rc->rcb = NULL;
}


/**
 * Change preferences for the given peer. Preference changes are forgotten if peers
 * disconnect.
 *
 * @param ph performance handle
 * @param peer identifies the peer
 * @param ... 0-terminated specification of the desired changes
 */
void
GNUNET_ATS_change_preference (struct GNUNET_ATS_PerformanceHandle *ph,
                              const struct GNUNET_PeerIdentity *peer, ...)
{
  struct PendingMessage *p;
  struct ChangePreferenceMessage *m;
  size_t msize;
  uint32_t count;
  struct PreferenceInformation *pi;
  va_list ap;
  enum GNUNET_ATS_PreferenceKind kind;

  count = 0;
  va_start (ap, peer);
  while (GNUNET_ATS_PREFERENCE_END !=
         (kind = va_arg (ap, enum GNUNET_ATS_PreferenceKind)))
  {
    switch (kind)
    {
    case GNUNET_ATS_PREFERENCE_BANDWIDTH:
      count++;
      (void) va_arg (ap, double);

      break;
    case GNUNET_ATS_PREFERENCE_LATENCY:
      count++;
      (void) va_arg (ap, double);

      break;
    default:
      GNUNET_assert (0);
    }
  }
  va_end (ap);
  msize =
      count * sizeof (struct PreferenceInformation) +
      sizeof (struct ChangePreferenceMessage);
  p = GNUNET_malloc (sizeof (struct PendingMessage) + msize);
  p->size = msize;
  p->is_init = GNUNET_NO;
  m = (struct ChangePreferenceMessage *) &p[1];
  m->header.type = htons (GNUNET_MESSAGE_TYPE_ATS_PREFERENCE_CHANGE);
  m->header.size = htons (msize);
  m->num_preferences = htonl (count);
  m->peer = *peer;
  pi = (struct PreferenceInformation *) &m[1];
  count = 0;
  va_start (ap, peer);
  while (GNUNET_ATS_PREFERENCE_END !=
         (kind = va_arg (ap, enum GNUNET_ATS_PreferenceKind)))
  {
    pi[count].preference_kind = htonl (kind);
    switch (kind)
    {
    case GNUNET_ATS_PREFERENCE_BANDWIDTH:
      pi[count].preference_value = (float) va_arg (ap, double);

      count++;
      break;
    case GNUNET_ATS_PREFERENCE_LATENCY:
      pi[count].preference_value = (float) va_arg (ap, double);

      count++;
      break;
    default:
      GNUNET_assert (0);
    }
  }
  va_end (ap);
  GNUNET_CONTAINER_DLL_insert_tail (ph->pending_head, ph->pending_tail, p);
  do_transmit (ph);
}

/* end of ats_api_performance.c */