summaryrefslogtreecommitdiff
path: root/src/mesh/mesh_api.c
blob: 4b6d6c4f95eb0d3b10777c05e11424b698752d9e (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
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
/*
     This file is part of GNUnet.
     (C) 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 mesh/mesh_api.c
 * @brief mesh api: client implementation of mesh service
 * @author Bartlomiej Polot
 *
 * STRUCTURE:
 * - CONSTANTS
 * - DATA STRUCTURES
 * - AUXILIARY FUNCTIONS
 * - RECEIVE HANDLERS
 * - SEND FUNCTIONS
 * - API CALL DEFINITIONS
 */
#ifdef __cplusplus
extern "C"
{
#if 0                           /* keep Emacsens' auto-indent happy */
}
#endif
#endif

#include "platform.h"
#include "gnunet_common.h"
#include "gnunet_client_lib.h"
#include "gnunet_util_lib.h"
#include "gnunet_peer_lib.h"
#include "gnunet_mesh_service.h"
#include "mesh.h"
#include "mesh_protocol.h"

#define MESH_API_DEBUG GNUNET_YES

#if MESH_API_DEBUG
#define LOG(kind,...) GNUNET_log_from (kind, "mesh-api",__VA_ARGS__)
#else
#define LOG(kind,...)
#endif

/******************************************************************************/
/************************      DATA STRUCTURES     ****************************/
/******************************************************************************/

/**
 * Transmission queue to the service
 */
struct GNUNET_MESH_TransmitHandle
{

    /**
     * Double Linked list
     */
  struct GNUNET_MESH_TransmitHandle *next;

    /**
     * Double Linked list
     */
  struct GNUNET_MESH_TransmitHandle *prev;

    /**
     * Tunnel this message is sent on / for (may be NULL for control messages).
     */
  struct GNUNET_MESH_Tunnel *tunnel;

    /**
     * Callback to obtain the message to transmit, or NULL if we
     * got the message in 'data'.  Notice that messages built
     * by 'notify' need to be encapsulated with information about
     * the 'target'.
     */
  GNUNET_CONNECTION_TransmitReadyNotify notify;

    /**
     * Closure for 'notify'
     */
  void *notify_cls;

    /**
     * How long is this message valid.  Once the timeout has been
     * reached, the message must no longer be sent.  If this
     * is a message with a 'notify' callback set, the 'notify'
     * function should be called with 'buf' NULL and size 0.
     */
  struct GNUNET_TIME_Absolute timeout;

    /**
     * Task triggering a timeout, can be NO_TASK if the timeout is FOREVER.
     */
  GNUNET_SCHEDULER_TaskIdentifier timeout_task;

    /**
     * Priority of the message.  The queue is sorted by priority,
     * control messages have the maximum priority (UINT32_MAX).
     */
  uint32_t priority;

    /**
     * Target of the message, 0 for multicast.  This field
     * is only valid if 'notify' is non-NULL.
     */
  GNUNET_PEER_Id target;

    /**
     * Size of 'data' -- or the desired size of 'notify' if 'data' is NULL.
     */
  size_t size;
};


/**
 * Opaque handle to the service.
 */
struct GNUNET_MESH_Handle
{

    /**
     * Handle to the server connection, to send messages later
     */
  struct GNUNET_CLIENT_Connection *client;

    /**
     * Set of handlers used for processing incoming messages in the tunnels
     */
  const struct GNUNET_MESH_MessageHandler *message_handlers;

    /**
     * Set of applications that should be claimed to be offered at this node.
     * Note that this is just informative, the appropiate handlers must be
     * registered independently and the mapping is up to the developer of the
     * client application.
     */
  const GNUNET_MESH_ApplicationType *applications;

    /**
     * Double linked list of the tunnels this client is connected to.
     */
  struct GNUNET_MESH_Tunnel *tunnels_head;
  struct GNUNET_MESH_Tunnel *tunnels_tail;

    /**
     * Callback for inbound tunnel creation
     */
  GNUNET_MESH_InboundTunnelNotificationHandler *new_tunnel;

    /**
     * Callback for inbound tunnel disconnection
     */
  GNUNET_MESH_TunnelEndHandler *cleaner;

    /**
     * Handle to cancel pending transmissions in case of disconnection
     */
  struct GNUNET_CLIENT_TransmitHandle *th;

    /**
     * Closure for all the handlers given by the client
     */
  void *cls;

    /**
     * Messages to send to the service
     */
  struct GNUNET_MESH_TransmitHandle *th_head;
  struct GNUNET_MESH_TransmitHandle *th_tail;

    /**
     * tid of the next tunnel to create (to avoid reusing IDs often)
     */
  MESH_TunnelNumber next_tid;
  unsigned int n_handlers;
  unsigned int n_applications;
  unsigned int max_queue_size;

    /**
     * Have we started the task to receive messages from the service
     * yet? We do this after we send the 'MESH_LOCAL_CONNECT' message.
     */
  int in_receive;

    /**
     * Number of packets queued
     */
  unsigned int npackets;

  /**
   * Configuration given by the client, in case of reconnection
   */
  const struct GNUNET_CONFIGURATION_Handle *cfg;

  /**
   * Time to the next reconnect in case one reconnect fails
   */
  struct GNUNET_TIME_Relative reconnect_time;
  
  /**
   * Task for trying to reconnect.
   */
  GNUNET_SCHEDULER_TaskIdentifier reconnect_task;
};


/**
 * Description of a peer
 */
struct GNUNET_MESH_Peer
{
    /**
     * ID of the peer in short form
     */
  GNUNET_PEER_Id id;

  /**
   * Tunnel this peer belongs to
   */
  struct GNUNET_MESH_Tunnel *t;

  /**
   * Flag indicating whether service has informed about its connection
   */
  int connected;

};


/**
 * Opaque handle to a tunnel.
 */
struct GNUNET_MESH_Tunnel
{

    /**
     * DLL
     */
  struct GNUNET_MESH_Tunnel *next;
  struct GNUNET_MESH_Tunnel *prev;

    /**
     * Callback to execute when peers connect to the tunnel
     */
  GNUNET_MESH_PeerConnectHandler connect_handler;

    /**
     * Callback to execute when peers disconnect from the tunnel
     */
  GNUNET_MESH_PeerDisconnectHandler disconnect_handler;

    /**
     * Closure for the connect/disconnect handlers
     */
  void *cls;

    /**
     * Handle to the mesh this tunnel belongs to
     */
  struct GNUNET_MESH_Handle *mesh;

    /**
     * Local ID of the tunnel
     */
  MESH_TunnelNumber tid;

    /**
     * Owner of the tunnel. 0 if the tunnel is the local client.
     */
  GNUNET_PEER_Id owner;

    /**
     * All peers added to the tunnel
     */
  struct GNUNET_MESH_Peer **peers;

  /**
   * List of application types that have been requested for this tunnel
   */
  GNUNET_MESH_ApplicationType *apps;

  /**
   * Any data the caller wants to put in here
   */
  void *ctx;

  /**
     * Number of peers added to the tunnel
     */
  unsigned int npeers;

    /**
     * Number of packets queued in this tunnel
     */
  unsigned int npackets;

    /**
     * Number of applications requested this tunnel
     */
  unsigned int napps;

};


/******************************************************************************/
/***********************     AUXILIARY FUNCTIONS      *************************/
/******************************************************************************/

/**
 * Get the tunnel handler for the tunnel specified by id from the given handle
 * @param h Mesh handle
 * @param tid ID of the wanted tunnel
 * @return handle to the required tunnel or NULL if not found
 */
static struct GNUNET_MESH_Tunnel *
retrieve_tunnel (struct GNUNET_MESH_Handle *h, MESH_TunnelNumber tid)
{
  struct GNUNET_MESH_Tunnel *t;

  t = h->tunnels_head;
  while (t != NULL)
  {
    if (t->tid == tid)
      return t;
    t = t->next;
  }
  return NULL;
}


/**
 * Create a new tunnel and insert it in the tunnel list of the mesh handle
 * @param h Mesh handle
 * @param tid desired tid of the tunnel, 0 to assign one automatically
 * @return handle to the created tunnel
 */
static struct GNUNET_MESH_Tunnel *
create_tunnel (struct GNUNET_MESH_Handle *h, MESH_TunnelNumber tid)
{
  struct GNUNET_MESH_Tunnel *t;

  t = GNUNET_malloc (sizeof (struct GNUNET_MESH_Tunnel));
  GNUNET_CONTAINER_DLL_insert (h->tunnels_head, h->tunnels_tail, t);
  t->mesh = h;
  if (0 == tid)
  {
    t->tid = h->next_tid;
    while (NULL != retrieve_tunnel (h, h->next_tid))
    {
      h->next_tid++;
      h->next_tid &= ~GNUNET_MESH_LOCAL_TUNNEL_ID_SERV;
      h->next_tid |= GNUNET_MESH_LOCAL_TUNNEL_ID_CLI;
    }
  }
  else
  {
    t->tid = tid;
  }
  return t;
}


/**
 * Destroy the specified tunnel.
 * - Destroys all peers, calling the disconnect callback on each if needed
 * - Cancels all outgoing traffic for that tunnel, calling respective notifys
 * - Calls cleaner if tunnel was inbound
 * - Frees all memory used
 *
 * @param t Pointer to the tunnel.
 * @param call_cleaner Whether to call the cleaner handler.
 *
 * @return Handle to the required tunnel or NULL if not found.
 */
static void
destroy_tunnel (struct GNUNET_MESH_Tunnel *t, int call_cleaner)
{
  struct GNUNET_MESH_Handle *h;
  struct GNUNET_PeerIdentity pi;
  struct GNUNET_MESH_TransmitHandle *th;
  struct GNUNET_MESH_TransmitHandle *next;
  unsigned int i;

  if (NULL == t)
  {
    GNUNET_break (0);
    return;
  }
  h = t->mesh;

  /* disconnect all peers */
  GNUNET_CONTAINER_DLL_remove (h->tunnels_head, h->tunnels_tail, t);
  for (i = 0; i < t->npeers; i++)
  {
    if ( (NULL != t->disconnect_handler) && t->peers[i]->connected)
    {
      GNUNET_PEER_resolve (t->peers[i]->id, &pi);
      t->disconnect_handler (t->cls, &pi);
    }
    GNUNET_PEER_change_rc (t->peers[i]->id, -1);
    GNUNET_free (t->peers[i]);
  }

  /* signal tunnel destruction */
  if ( (NULL != h->cleaner) && (0 != t->owner) && (GNUNET_YES == call_cleaner) )
    h->cleaner (h->cls, t, t->ctx);

  /* check that clients did not leave messages behind in the queue */
  for (th = h->th_head; NULL != th; th = next)
  {
    next = th->next;
    if (th->tunnel != t)
      continue;
    /* Clients should have aborted their requests already.
     * Management traffic should be ok, as clients can't cancel that */
    GNUNET_break (NULL == th->notify);
    GNUNET_CONTAINER_DLL_remove (h->th_head, h->th_tail, th);

    /* clean up request */
    if (GNUNET_SCHEDULER_NO_TASK != th->timeout_task)
      GNUNET_SCHEDULER_cancel (th->timeout_task);
    GNUNET_free (th);    
  }

  /* if there are no more pending requests with mesh service, cancel active request */
  /* Note: this should be unnecessary... */
  if ( (NULL == h->th_head) && (NULL != h->th))
  {
    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
    h->th = NULL;
  }


  if (t->npeers > 0)
    GNUNET_free (t->peers);
  if (0 != t->owner)
    GNUNET_PEER_change_rc (t->owner, -1);
  if (0 != t->napps && t->apps)
    GNUNET_free (t->apps);
  GNUNET_free (t);
  return;
}


/**
 * Get the peer descriptor for the peer with id from the given tunnel
 * @param t Tunnel handle
 * @param id Short form ID of the wanted peer
 * @return handle to the requested peer or NULL if not found
 */
static struct GNUNET_MESH_Peer *
retrieve_peer (struct GNUNET_MESH_Tunnel *t, GNUNET_PEER_Id id)
{
  unsigned int i;

  for (i = 0; i < t->npeers; i++)
    if (t->peers[i]->id == id)
      return t->peers[i];
  return NULL;
}


/**
 * Add a peer into a tunnel
 * @param t Tunnel handle
 * @param pi Full ID of the new peer
 * @return handle to the newly created peer
 */
static struct GNUNET_MESH_Peer *
add_peer_to_tunnel (struct GNUNET_MESH_Tunnel *t,
                    const struct GNUNET_PeerIdentity *pi)
{
  struct GNUNET_MESH_Peer *p;
  GNUNET_PEER_Id id;

  if (0 != t->owner)
  {
    GNUNET_break (0);
    return NULL;
  }
  id = GNUNET_PEER_intern (pi);

  p = GNUNET_malloc (sizeof (struct GNUNET_MESH_Peer));
  p->id = id;
  p->t = t;
  GNUNET_array_append (t->peers, t->npeers, p);
  return p;
}


/**
 * Remove a peer from a tunnel
 * @param p Peer handle
 */
static void
remove_peer_from_tunnel (struct GNUNET_MESH_Peer *p)
{
  unsigned int i;

  for (i = 0; i < p->t->npeers; i++)
  {
    if (p->t->peers[i] == p)
      break;
  }
  if (i == p->t->npeers)
  {
    GNUNET_break (0);
    return;
  }
  p->t->peers[i] = p->t->peers[p->t->npeers - 1];
  GNUNET_array_grow (p->t->peers, p->t->npeers, p->t->npeers - 1);
}


/**
 * Notify client that the transmission has timed out
 * @param cls closure
 * @param tc task context
 */
static void
timeout_transmission (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct GNUNET_MESH_TransmitHandle *th = cls;
  struct GNUNET_MESH_Handle *mesh;

  mesh = th->tunnel->mesh;
  GNUNET_CONTAINER_DLL_remove (mesh->th_head, mesh->th_tail, th);
  if (th->notify != NULL)
    th->notify (th->notify_cls, 0, NULL);
  GNUNET_free (th);
  if ((NULL == mesh->th_head) && (NULL != mesh->th))
  {
    /* queue empty, no point in asking for transmission */
    GNUNET_CLIENT_notify_transmit_ready_cancel (mesh->th);
    mesh->th = NULL;
  }
}


/**
 * Add a transmit handle to the transmission queue by priority and set the
 * timeout if needed.
 *
 * @param h mesh handle with the queue head and tail
 * @param th handle to the packet to be transmitted
 */
static void
add_to_queue (struct GNUNET_MESH_Handle *h,
              struct GNUNET_MESH_TransmitHandle *th)
{
  struct GNUNET_MESH_TransmitHandle *p;

  p = h->th_head;
  while ((NULL != p) && (th->priority <= p->priority))
    p = p->next;
  if (NULL == p)
    p = h->th_tail;
  else
    p = p->prev;
  GNUNET_CONTAINER_DLL_insert_after (h->th_head, h->th_tail, p, th);
  if (GNUNET_TIME_UNIT_FOREVER_ABS.abs_value == th->timeout.abs_value)
    return;
  th->timeout_task =
      GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_absolute_get_remaining
                                    (th->timeout), &timeout_transmission, th);
}


/**
 * Auxiliary function to send an already constructed packet to the service.
 * Takes care of creating a new queue element, copying the message and
 * calling the tmt_rdy function if necessary.
 *
 * @param h mesh handle
 * @param msg message to transmit
 * @param tunnel tunnel this send is related to (NULL if N/A)
 */
static void
send_packet (struct GNUNET_MESH_Handle *h,
             const struct GNUNET_MessageHeader *msg,
             struct GNUNET_MESH_Tunnel *tunnel);


/**
 * Reconnect callback: tries to reconnect again after a failer previous
 * reconnecttion
 * @param cls closure (mesh handle)
 * @param tc task context
 */
static void
reconnect_cbk (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc);


/**
 * Send a connect packet to the service with the applications and types
 * requested by the user.
 *
 * @param h The mesh handle.
 *
 */
static void
send_connect (struct GNUNET_MESH_Handle *h)
{
  size_t size;

  size = sizeof (struct GNUNET_MESH_ClientConnect);
  size += h->n_applications * sizeof (GNUNET_MESH_ApplicationType);
  size += h->n_handlers * sizeof (uint16_t);
  {
    char buf[size];
    struct GNUNET_MESH_ClientConnect *msg;
    GNUNET_MESH_ApplicationType *apps;
    uint16_t napps;
    uint16_t *types;
    uint16_t ntypes;

    /* build connection packet */
    msg = (struct GNUNET_MESH_ClientConnect *) buf;
    msg->header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_CONNECT);
    msg->header.size = htons (size);
    apps = (GNUNET_MESH_ApplicationType *) &msg[1];
    for (napps = 0; napps < h->n_applications; napps++)
    {
      apps[napps] = htonl (h->applications[napps]);
      LOG (GNUNET_ERROR_TYPE_DEBUG, " app %u\n", h->applications[napps]);
    }
    types = (uint16_t *) & apps[napps];
    for (ntypes = 0; ntypes < h->n_handlers; ntypes++)
      types[ntypes] = htons (h->message_handlers[ntypes].type);
    msg->applications = htons (napps);
    msg->types = htons (ntypes);
    LOG (GNUNET_ERROR_TYPE_DEBUG,
         "Sending %lu bytes long message %d types and %d apps\n",
         ntohs (msg->header.size), ntypes, napps);
    send_packet (h, &msg->header, NULL);
  }
}


/**
 * Reconnect to the service, retransmit all infomation to try to restore the
 * original state.
 *
 * @param h handle to the mesh
 *
 * @return GNUNET_YES in case of sucess, GNUNET_NO otherwise (service down...)
 */
static int
do_reconnect (struct GNUNET_MESH_Handle *h)
{
  struct GNUNET_MESH_Tunnel *t;
  unsigned int i;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "*****************************\n");
  LOG (GNUNET_ERROR_TYPE_DEBUG, "*******   RECONNECT   *******\n");
  LOG (GNUNET_ERROR_TYPE_DEBUG, "*****************************\n");

  h->in_receive = GNUNET_NO;
  /* disconnect */
  if (NULL != h->th)
  {
    GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
    h->th = NULL;
  }
  if (NULL != h->client)
  {
    GNUNET_CLIENT_disconnect (h->client);
  }

  /* connect again */
  h->client = GNUNET_CLIENT_connect ("mesh", h->cfg);
  if (h->client == NULL)
  {
    h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->reconnect_time,
                                                      &reconnect_cbk, h);
    h->reconnect_time =
        GNUNET_TIME_relative_min (GNUNET_TIME_UNIT_SECONDS,
                                  GNUNET_TIME_relative_multiply
                                  (h->reconnect_time, 2));
    LOG (GNUNET_ERROR_TYPE_DEBUG, "  Next retry in %sms\n",
         GNUNET_TIME_relative_to_string (h->reconnect_time));
    GNUNET_break (0);
    return GNUNET_NO;
  }
  else
  {
    h->reconnect_time = GNUNET_TIME_UNIT_MILLISECONDS;
  }
  send_connect (h);
  /* Rebuild all tunnels */
  for (t = h->tunnels_head; NULL != t; t = t->next)
  {
    struct GNUNET_MESH_TunnelMessage tmsg;
    struct GNUNET_MESH_PeerControl pmsg;

    if (t->tid >= GNUNET_MESH_LOCAL_TUNNEL_ID_SERV)
    {
      /* Tunnel was created by service (incoming tunnel) */
      /* TODO: Notify service of missing tunnel, to request
       * creator to recreate path (find a path to him via DHT?)
       */
      continue;
    }
    tmsg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_CREATE);
    tmsg.header.size = htons (sizeof (struct GNUNET_MESH_TunnelMessage));
    tmsg.tunnel_id = htonl (t->tid);
    send_packet (h, &tmsg.header, t);

    pmsg.header.size = htons (sizeof (struct GNUNET_MESH_PeerControl));
    pmsg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD);
    pmsg.tunnel_id = htonl (t->tid);

    /* Reconnect all peers */
    for (i = 0; i < t->npeers; i++)
    {
      GNUNET_PEER_resolve (t->peers[i]->id, &pmsg.peer);
      if (NULL != t->disconnect_handler && t->peers[i]->connected)
        t->disconnect_handler (t->cls, &pmsg.peer);
      /* If the tunnel was "by type", dont connect individual peers */
      if (0 == t->napps)
        send_packet (t->mesh, &pmsg.header, t);
    }
    /* Reconnect all types, if any  */
    for (i = 0; i < t->napps; i++)
    {
      struct GNUNET_MESH_ConnectPeerByType msg;

      msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectPeerByType));
      msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD_BY_TYPE);
      msg.tunnel_id = htonl (t->tid);
      msg.type = htonl (t->apps[i]);
      send_packet (t->mesh, &msg.header, t);
    }
  }
  return GNUNET_YES;
}

/**
 * Reconnect callback: tries to reconnect again after a failer previous
 * reconnecttion
 * @param cls closure (mesh handle)
 * @param tc task context
 */
static void
reconnect_cbk (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct GNUNET_MESH_Handle *h = cls;

  h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
    return;
  do_reconnect (h);
}


/**
 * Reconnect to the service, retransmit all infomation to try to restore the
 * original state.
 *
 * @param h handle to the mesh
 *
 * @return GNUNET_YES in case of sucess, GNUNET_NO otherwise (service down...)
 */
static void
reconnect (struct GNUNET_MESH_Handle *h)
{
  LOG (GNUNET_ERROR_TYPE_DEBUG, "Requested RECONNECT\n");
  if (GNUNET_SCHEDULER_NO_TASK == h->reconnect_task)
    h->reconnect_task = GNUNET_SCHEDULER_add_delayed (h->reconnect_time,
                                                      &reconnect_cbk, h);
}


/******************************************************************************/
/***********************      RECEIVE HANDLERS     ****************************/
/******************************************************************************/

/**
 * Process the new tunnel notification and add it to the tunnels in the handle
 *
 * @param h     The mesh handle
 * @param msg   A message with the details of the new incoming tunnel
 */
static void
process_tunnel_created (struct GNUNET_MESH_Handle *h,
                        const struct GNUNET_MESH_TunnelNotification *msg)
{
  struct GNUNET_MESH_Tunnel *t;
  MESH_TunnelNumber tid;

  tid = ntohl (msg->tunnel_id);
  if (tid < GNUNET_MESH_LOCAL_TUNNEL_ID_SERV)
  {
    GNUNET_break (0);
    return;
  }
  if (NULL != h->new_tunnel)
  {
    struct GNUNET_ATS_Information atsi;

    t = create_tunnel (h, tid);
    t->owner = GNUNET_PEER_intern (&msg->peer);
    t->npeers = 1;
    t->peers = GNUNET_malloc (sizeof (struct GNUNET_MESH_Peer *));
    t->peers[0] = GNUNET_malloc (sizeof (struct GNUNET_MESH_Peer));
    t->peers[0]->t = t;
    t->peers[0]->connected = 1;
    t->peers[0]->id = t->owner;
    GNUNET_PEER_change_rc (t->owner, 1);
    t->mesh = h;
    t->tid = tid;
    atsi.type = 0;
    atsi.value = 0;
    t->ctx = h->new_tunnel (h->cls, t, &msg->peer, &atsi);
    LOG (GNUNET_ERROR_TYPE_DEBUG, "new incoming tunnel %X\n", t->tid);
  }
  else
  {
    struct GNUNET_MESH_TunnelMessage d_msg;

    LOG (GNUNET_ERROR_TYPE_DEBUG, "No handler for incoming tunnels\n");

    d_msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_DESTROY);
    d_msg.header.size = htons (sizeof (struct GNUNET_MESH_TunnelMessage));
    d_msg.tunnel_id = msg->tunnel_id;

    send_packet (h, &d_msg.header, NULL);
  }
  return;
}


/**
 * Process the tunnel destroy notification and free associated resources
 *
 * @param h     The mesh handle
 * @param msg   A message with the details of the tunnel being destroyed
 */
static void
process_tunnel_destroy (struct GNUNET_MESH_Handle *h,
                        const struct GNUNET_MESH_TunnelMessage *msg)
{
  struct GNUNET_MESH_Tunnel *t;
  MESH_TunnelNumber tid;

  tid = ntohl (msg->tunnel_id);
  t = retrieve_tunnel (h, tid);

  if (NULL == t)
  {
    return;
  }
  if (0 == t->owner)
  {
    GNUNET_break (0);
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel %u destroyed\n", t->tid);
  destroy_tunnel (t, GNUNET_YES);
  return;
}


/**
 * Process the new peer event and notify the upper level of it
 *
 * @param h     The mesh handle
 * @param msg   A message with the details of the peer event
 */
static void
process_peer_event (struct GNUNET_MESH_Handle *h,
                    const struct GNUNET_MESH_PeerControl *msg)
{
  struct GNUNET_MESH_Tunnel *t;
  struct GNUNET_MESH_Peer *p;
  struct GNUNET_ATS_Information atsi;
  GNUNET_PEER_Id id;
  uint16_t size;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "processig peer event\n");
  size = ntohs (msg->header.size);
  if (size != sizeof (struct GNUNET_MESH_PeerControl))
  {
    GNUNET_break (0);
    return;
  }
  t = retrieve_tunnel (h, ntohl (msg->tunnel_id));
  if (NULL == t)
  {
    GNUNET_break (0);
    return;
  }
  id = GNUNET_PEER_search (&msg->peer);
  if ((p = retrieve_peer (t, id)) == NULL)
    p = add_peer_to_tunnel (t, &msg->peer);
  if (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD == ntohs (msg->header.type))
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "adding peer\n");
    if (NULL != t->connect_handler)
    {
      atsi.type = 0;
      atsi.value = 0;
      t->connect_handler (t->cls, &msg->peer, &atsi);
    }
    p->connected = 1;
  }
  else
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "removing peer\n");
    if (NULL != t->disconnect_handler && p->connected)
    {
      t->disconnect_handler (t->cls, &msg->peer);
    }
    remove_peer_from_tunnel (p);
    GNUNET_free (p);
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "processing peer event END\n");
}


/**
 * Process the incoming data packets
 *
 * @param h         The mesh handle
 * @param message   A message encapsulating the data
 * 
 * @return GNUNET_YES if everything went fine
 *         GNUNET_NO if client closed connection (h no longer valid)
 */
static int
process_incoming_data (struct GNUNET_MESH_Handle *h,
                       const struct GNUNET_MessageHeader *message)
{
  const struct GNUNET_MessageHeader *payload;
  const struct GNUNET_MESH_MessageHandler *handler;
  const struct GNUNET_PeerIdentity *peer;
  struct GNUNET_MESH_Unicast *ucast;
  struct GNUNET_MESH_Multicast *mcast;
  struct GNUNET_MESH_ToOrigin *to_orig;
  struct GNUNET_MESH_Tunnel *t;
  unsigned int i;
  uint16_t type;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Got a data message!\n");
  type = ntohs (message->type);
  switch (type)
  {
  case GNUNET_MESSAGE_TYPE_MESH_UNICAST:
    ucast = (struct GNUNET_MESH_Unicast *) message;

    t = retrieve_tunnel (h, ntohl (ucast->tid));
    payload = (struct GNUNET_MessageHeader *) &ucast[1];
    peer = &ucast->oid;
    LOG (GNUNET_ERROR_TYPE_DEBUG, "  ucast on tunnel %s [%x]\n",
         GNUNET_i2s (peer), ntohl (ucast->tid));
    break;
  case GNUNET_MESSAGE_TYPE_MESH_MULTICAST:
    mcast = (struct GNUNET_MESH_Multicast *) message;
    t = retrieve_tunnel (h, ntohl (mcast->tid));
    payload = (struct GNUNET_MessageHeader *) &mcast[1];
    peer = &mcast->oid;
    LOG (GNUNET_ERROR_TYPE_DEBUG, "  mcast on tunnel %s [%x]\n",
         GNUNET_i2s (peer), ntohl (mcast->tid));
    break;
  case GNUNET_MESSAGE_TYPE_MESH_TO_ORIGIN:
    to_orig = (struct GNUNET_MESH_ToOrigin *) message;
    t = retrieve_tunnel (h, ntohl (to_orig->tid));
    payload = (struct GNUNET_MessageHeader *) &to_orig[1];
    peer = &to_orig->sender;
    LOG (GNUNET_ERROR_TYPE_DEBUG, "  torig on tunnel %s [%x]\n",
         GNUNET_i2s (peer), ntohl (to_orig->tid));
    break;
  default:
    GNUNET_break (0);
    return GNUNET_YES;
  }
  if (NULL == t)
  {
    GNUNET_break (0);
    return GNUNET_YES;
  }
  type = ntohs (payload->type);
  for (i = 0; i < h->n_handlers; i++)
  {
    handler = &h->message_handlers[i];
    if (handler->type == type)
    {
      struct GNUNET_ATS_Information atsi;

      atsi.type = 0;
      atsi.value = 0;
      if (GNUNET_OK !=
          handler->callback (h->cls, t, &t->ctx, peer, payload, &atsi))
      {
        LOG (GNUNET_ERROR_TYPE_DEBUG, "MESH: callback caused disconnection\n");
        GNUNET_MESH_disconnect (h);
        return GNUNET_NO;
      }
      else
      {
        LOG (GNUNET_ERROR_TYPE_DEBUG,
             "MESH: callback completed successfully\n");

      }
    }
  }
  return GNUNET_YES;
}


/**
 * Function to process all messages received from the service
 *
 * @param cls closure
 * @param msg message received, NULL on timeout or fatal error
 */
static void
msg_received (void *cls, const struct GNUNET_MessageHeader *msg)
{
  struct GNUNET_MESH_Handle *h = cls;

  if (msg == NULL)
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "Received NULL msg\n");
    reconnect (h);
    return;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "received a message type %hu from MESH\n",
       ntohs (msg->type));
  switch (ntohs (msg->type))
  {
    /* Notify of a new incoming tunnel */
  case GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_CREATE:
    process_tunnel_created (h, (struct GNUNET_MESH_TunnelNotification *) msg);
    break;
    /* Notify of a tunnel disconnection */
  case GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_DESTROY:
    process_tunnel_destroy (h, (struct GNUNET_MESH_TunnelMessage *) msg);
    break;
    /* Notify of a new peer or a peer disconnect in the tunnel */
  case GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD:
  case GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_DEL:
    process_peer_event (h, (struct GNUNET_MESH_PeerControl *) msg);
    break;
    /* Notify of a new data packet in the tunnel */
  case GNUNET_MESSAGE_TYPE_MESH_UNICAST:
  case GNUNET_MESSAGE_TYPE_MESH_MULTICAST:
  case GNUNET_MESSAGE_TYPE_MESH_TO_ORIGIN:
    if (GNUNET_NO == process_incoming_data (h, msg))
      return;
    break;
    /* We shouldn't get any other packages, log and ignore */
  default:
    LOG (GNUNET_ERROR_TYPE_WARNING,
         "MESH: unsolicited message form service (type %d)\n",
         ntohs (msg->type));
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "message processed\n");
  GNUNET_CLIENT_receive (h->client, &msg_received, h,
                         GNUNET_TIME_UNIT_FOREVER_REL);
}


/******************************************************************************/
/************************       SEND FUNCTIONS     ****************************/
/******************************************************************************/

/**
 * Function called to send a message to the service.
 * "buf" will be NULL and "size" zero if the socket was closed for writing in
 * the meantime.
 *
 * @param cls closure, the mesh handle
 * @param size number of bytes available in buf
 * @param buf where the callee should write the connect message
 * @return number of bytes written to buf
 */
static size_t
send_callback (void *cls, size_t size, void *buf)
{
  struct GNUNET_MESH_Handle *h = cls;
  struct GNUNET_MESH_TransmitHandle *th;
  char *cbuf = buf;
  size_t tsize;
  size_t psize;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Send packet() Buffer %u\n", size);
  h->th = NULL;
  if ((0 == size) || (NULL == buf))
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "Received NULL callback\n");
    reconnect (h);
    return 0;
  }
  tsize = 0;
  while ((NULL != (th = h->th_head)) && (size >= th->size))
  {
    if (NULL != th->notify)
    {
      if (th->tunnel->tid >= GNUNET_MESH_LOCAL_TUNNEL_ID_SERV)
      {
        /* traffic to origin */
        struct GNUNET_MESH_ToOrigin to;
        struct GNUNET_MessageHeader *mh;

        GNUNET_assert (size >= th->size);
        mh = (struct GNUNET_MessageHeader *) &cbuf[sizeof (to)];
        psize = th->notify (th->notify_cls, size - sizeof (to), mh);
        LOG (GNUNET_ERROR_TYPE_DEBUG, "  to origin, type %u\n",
             ntohs (mh->type));
        if (psize > 0)
        {
          psize += sizeof (to);
          GNUNET_assert (size >= psize);
          to.header.size = htons (psize);
          to.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_TO_ORIGIN);
          to.tid = htonl (th->tunnel->tid);
          memset (&to.oid, 0, sizeof (struct GNUNET_PeerIdentity));
          memset (&to.sender, 0, sizeof (struct GNUNET_PeerIdentity));
          memcpy (cbuf, &to, sizeof (to));
        }
      }
      else if (th->target == 0)
      {
        /* multicast */
        struct GNUNET_MESH_Multicast mc;
        struct GNUNET_MessageHeader *mh;

        GNUNET_assert (size >= th->size);
        mh = (struct GNUNET_MessageHeader *) &cbuf[sizeof (mc)];
        psize = th->notify (th->notify_cls, size - sizeof (mc), mh);
        LOG (GNUNET_ERROR_TYPE_DEBUG, "  multicast, type %u\n",
             ntohs (mh->type));
        if (psize > 0)
        {
          psize += sizeof (mc);
          GNUNET_assert (size >= psize);
          mc.header.size = htons (psize);
          mc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_MULTICAST);
          mc.tid = htonl (th->tunnel->tid);
          mc.mid = 0;
          mc.ttl = 0;
          memset (&mc.oid, 0, sizeof (struct GNUNET_PeerIdentity));
          memcpy (cbuf, &mc, sizeof (mc));
        }
      }
      else
      {
        /* unicast */
        struct GNUNET_MESH_Unicast uc;
        struct GNUNET_MessageHeader *mh;

        GNUNET_assert (size >= th->size);
        mh = (struct GNUNET_MessageHeader *) &cbuf[sizeof (uc)];
        psize = th->notify (th->notify_cls, size - sizeof (uc), mh);
        LOG (GNUNET_ERROR_TYPE_DEBUG, "  unicast, type %u\n",
             ntohs (mh->type));
        if (psize > 0)
        {
          psize += sizeof (uc);
          GNUNET_assert (size >= psize);
          uc.header.size = htons (psize);
          uc.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_UNICAST);
          uc.tid = htonl (th->tunnel->tid);
          memset (&uc.oid, 0, sizeof (struct GNUNET_PeerIdentity));
          GNUNET_PEER_resolve (th->target, &uc.destination);
          memcpy (cbuf, &uc, sizeof (uc));
        }
      }
    }
    else
    {
      memcpy (cbuf, &th[1], th->size);
      psize = th->size;
    }
    if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
      GNUNET_SCHEDULER_cancel (th->timeout_task);
    if (NULL != th->notify)
    {
      th->tunnel->mesh->npackets--;
      th->tunnel->npackets--;
    }
    GNUNET_CONTAINER_DLL_remove (h->th_head, h->th_tail, th);
    GNUNET_free (th);
    cbuf += psize;
    size -= psize;
    tsize += psize;
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "  total size: %u\n", tsize);
  if (NULL != (th = h->th_head))
  {
    LOG (GNUNET_ERROR_TYPE_DEBUG, "  next size: %u\n", th->size);
    if (NULL == h->th)
      h->th =
          GNUNET_CLIENT_notify_transmit_ready (h->client, th->size,
                                               GNUNET_TIME_UNIT_FOREVER_REL,
                                               GNUNET_YES, &send_callback, h);
  }
  LOG (GNUNET_ERROR_TYPE_DEBUG, "Send packet() END\n");
  if (GNUNET_NO == h->in_receive)
  {
    h->in_receive = GNUNET_YES;
    GNUNET_CLIENT_receive (h->client, &msg_received, h,
                           GNUNET_TIME_UNIT_FOREVER_REL);
  }
  return tsize;
}


/**
 * Auxiliary function to send an already constructed packet to the service.
 * Takes care of creating a new queue element, copying the message and
 * calling the tmt_rdy function if necessary.
 * 
 * @param h mesh handle
 * @param msg message to transmit
 * @param tunnel tunnel this send is related to (NULL if N/A)
 */
static void
send_packet (struct GNUNET_MESH_Handle *h,
             const struct GNUNET_MessageHeader *msg,
             struct GNUNET_MESH_Tunnel *tunnel)
{
  struct GNUNET_MESH_TransmitHandle *th;
  size_t msize;

  msize = ntohs (msg->size);
  th = GNUNET_malloc (sizeof (struct GNUNET_MESH_TransmitHandle) + msize);
  th->priority = UINT32_MAX;
  th->timeout = GNUNET_TIME_UNIT_FOREVER_ABS;
  th->size = msize;
  th->tunnel = tunnel;
  memcpy (&th[1], msg, msize);
  add_to_queue (h, th);
  if (NULL != h->th)
    return;
  h->th =
      GNUNET_CLIENT_notify_transmit_ready (h->client, msize,
                                           GNUNET_TIME_UNIT_FOREVER_REL,
                                           GNUNET_YES, &send_callback, h);
}


/******************************************************************************/
/**********************      API CALL DEFINITIONS     *************************/
/******************************************************************************/

/**
 * Connect to the mesh service.
 *
 * @param cfg configuration to use
 * @param queue_size size of the data message queue, shared among all tunnels
 *                   (each tunnel is guaranteed to accept at least one message,
 *                    no matter what is the status of other tunnels)
 * @param cls closure for the various callbacks that follow
 *            (including handlers in the handlers array)
 * @param new_tunnel function called when an *inbound* tunnel is created
 * @param cleaner function called when an *inbound* tunnel is destroyed by the
 *                remote peer, it is *not* called if GNUNET_MESH_tunnel_destroy
 *                is called on the tunnel
 * @param handlers callbacks for messages we care about, NULL-terminated
 *                note that the mesh is allowed to drop notifications about
 *                inbound messages if the client does not process them fast
 *                enough (for this notification type, a bounded queue is used)
 * @param stypes list of the applications that this client claims to provide
 * @return handle to the mesh service NULL on error
 *         (in this case, init is never called)
 */
struct GNUNET_MESH_Handle *
GNUNET_MESH_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
                     unsigned int queue_size, void *cls,
                     GNUNET_MESH_InboundTunnelNotificationHandler new_tunnel,
                     GNUNET_MESH_TunnelEndHandler cleaner,
                     const struct GNUNET_MESH_MessageHandler *handlers,
                     const GNUNET_MESH_ApplicationType *stypes)
{
  struct GNUNET_MESH_Handle *h;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "GNUNET_MESH_connect()\n");
  h = GNUNET_malloc (sizeof (struct GNUNET_MESH_Handle));
  h->cfg = cfg;
  h->max_queue_size = queue_size;
  h->new_tunnel = new_tunnel;
  h->cleaner = cleaner;
  h->client = GNUNET_CLIENT_connect ("mesh", cfg);
  if (h->client == NULL)
  {
    GNUNET_break (0);
    GNUNET_free (h);
    return NULL;
  }
  h->cls = cls;
  /* FIXME memdup? */
  h->applications = stypes;
  h->message_handlers = handlers;
  h->next_tid = GNUNET_MESH_LOCAL_TUNNEL_ID_CLI;
  h->reconnect_time = GNUNET_TIME_UNIT_MILLISECONDS;
  h->reconnect_task = GNUNET_SCHEDULER_NO_TASK;

  /* count handlers and apps, calculate size */
  for (h->n_applications = 0; stypes[h->n_applications]; h->n_applications++) ;
  for (h->n_handlers = 0; handlers[h->n_handlers].type; h->n_handlers++) ;
  send_connect (h);
  LOG (GNUNET_ERROR_TYPE_DEBUG, "GNUNET_MESH_connect() END\n");
  return h;
}


/**
 * Disconnect from the mesh service. All tunnels will be destroyed. All tunnel
 * disconnect callbacks will be called on any still connected peers, notifying
 * about their disconnection. The registered inbound tunnel cleaner will be
 * called should any inbound tunnels still exist.
 *
 * @param handle connection to mesh to disconnect
 */
void
GNUNET_MESH_disconnect (struct GNUNET_MESH_Handle *handle)
{
  struct GNUNET_MESH_Tunnel *t;
  struct GNUNET_MESH_Tunnel *aux;
  struct GNUNET_MESH_TransmitHandle *th;

  t = handle->tunnels_head;
  while (NULL != t)
  {
    aux = t->next;
    if (t->tid < GNUNET_MESH_LOCAL_TUNNEL_ID_SERV)
    {
      GNUNET_break (0);
      LOG (GNUNET_ERROR_TYPE_DEBUG, "tunnel %X not destroyed\n", t->tid);
    }
    destroy_tunnel (t, GNUNET_YES);
    t = aux;
  }
  while ( (th = handle->th_head) != NULL)
  {
    struct GNUNET_MessageHeader *msg;

    /* Make sure it is an allowed packet (everything else should have been
     * already canceled).
     */
    GNUNET_break (UINT32_MAX == th->priority);
    GNUNET_break (NULL == th->notify);
    msg = (struct GNUNET_MessageHeader *) &th[1];
    switch (ntohs(msg->type))
    {
      case GNUNET_MESSAGE_TYPE_MESH_LOCAL_CONNECT:
      case GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_DESTROY:
        break;
      default:
        GNUNET_break (0);
        LOG (GNUNET_ERROR_TYPE_DEBUG, "unexpected msg %u\n",
             ntohs(msg->type));
    }

    GNUNET_CONTAINER_DLL_remove (handle->th_head, handle->th_tail, th);
    GNUNET_free (th);
  }

  if (NULL != handle->th)
  {
    GNUNET_CLIENT_notify_transmit_ready_cancel (handle->th);
    handle->th = NULL;
  }
  if (NULL != handle->client)
  {
    GNUNET_CLIENT_disconnect (handle->client);
    handle->client = NULL;
  }
  if (GNUNET_SCHEDULER_NO_TASK != handle->reconnect_task)
  {
    GNUNET_SCHEDULER_cancel(handle->reconnect_task);
    handle->reconnect_task = GNUNET_SCHEDULER_NO_TASK;
  }
  GNUNET_free (handle);
}


/**
 * Create a new tunnel (we're initiator and will be allowed to add/remove peers
 * and to broadcast).
 *
 * @param h mesh handle
 * @param tunnel_ctx client's tunnel context to associate with the tunnel
 * @param connect_handler function to call when peers are actually connected
 * @param disconnect_handler function to call when peers are disconnected
 * @param handler_cls closure for connect/disconnect handlers
 */
struct GNUNET_MESH_Tunnel *
GNUNET_MESH_tunnel_create (struct GNUNET_MESH_Handle *h, void *tunnel_ctx,
                           GNUNET_MESH_PeerConnectHandler connect_handler,
                           GNUNET_MESH_PeerDisconnectHandler disconnect_handler,
                           void *handler_cls)
{
  struct GNUNET_MESH_Tunnel *t;
  struct GNUNET_MESH_TunnelMessage msg;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Creating new tunnel\n");
  t = create_tunnel (h, 0);
  t->connect_handler = connect_handler;
  t->disconnect_handler = disconnect_handler;
  t->cls = handler_cls;
  t->ctx = tunnel_ctx;
  msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_CREATE);
  msg.header.size = htons (sizeof (struct GNUNET_MESH_TunnelMessage));
  msg.tunnel_id = htonl (t->tid);
  send_packet (h, &msg.header, t);
  return t;
}


/**
 * Destroy an existing tunnel. The existing callback for the tunnel will NOT
 * be called.
 *
 * @param tunnel tunnel handle
 */
void
GNUNET_MESH_tunnel_destroy (struct GNUNET_MESH_Tunnel *tunnel)
{
  struct GNUNET_MESH_Handle *h;
  struct GNUNET_MESH_TunnelMessage msg;
  struct GNUNET_MESH_TransmitHandle *th;

  LOG (GNUNET_ERROR_TYPE_DEBUG, "Destroying tunnel\n");
  h = tunnel->mesh;

  msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_TUNNEL_DESTROY);
  msg.header.size = htons (sizeof (struct GNUNET_MESH_TunnelMessage));
  msg.tunnel_id = htonl (tunnel->tid);
  th = h->th_head;
  while (th != NULL)
  {
    struct GNUNET_MESH_TransmitHandle *aux;
    if (th->tunnel == tunnel)
    {
      aux = th->next;
      /* FIXME call the handler? */
      if (NULL != th->notify)
        th->notify (th->notify_cls, 0, NULL);
      GNUNET_CONTAINER_DLL_remove (h->th_head, h->th_tail, th);
      GNUNET_free (th);
      th = aux;
    }
    else
      th = th->next;
  }

  destroy_tunnel (tunnel, GNUNET_NO);
  send_packet (h, &msg.header, NULL);
}


/**
 * Request that a peer should be added to the tunnel.  The existing
 * connect handler will be called ONCE with either success or failure.
 * This function should NOT be called again with the same peer before the
 * connect handler is called.
 *
 * @param tunnel handle to existing tunnel
 * @param peer peer to add
 */
void
GNUNET_MESH_peer_request_connect_add (struct GNUNET_MESH_Tunnel *tunnel,
                                      const struct GNUNET_PeerIdentity *peer)
{
  struct GNUNET_MESH_PeerControl msg;
  GNUNET_PEER_Id peer_id;
  unsigned int i;

  peer_id = GNUNET_PEER_intern (peer);
  for (i = 0; i < tunnel->npeers; i++)
  {
    if (tunnel->peers[i]->id == peer_id)
    {
      /* Peer already exists in tunnel */
      GNUNET_PEER_change_rc (peer_id, -1);
      GNUNET_break (0);
      return;
    }
  }
  if (NULL == add_peer_to_tunnel (tunnel, peer))
    return;

  msg.header.size = htons (sizeof (struct GNUNET_MESH_PeerControl));
  msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD);
  msg.tunnel_id = htonl (tunnel->tid);
  msg.peer = *peer;
  send_packet (tunnel->mesh, &msg.header, tunnel);

  return;
}


/**
 * Request that a peer should be removed from the tunnel.  The existing
 * disconnect handler will be called ONCE if we were connected.
 *
 * @param tunnel handle to existing tunnel
 * @param peer peer to remove
 */
void
GNUNET_MESH_peer_request_connect_del (struct GNUNET_MESH_Tunnel *tunnel,
                                      const struct GNUNET_PeerIdentity *peer)
{
  struct GNUNET_MESH_PeerControl msg;
  GNUNET_PEER_Id peer_id;
  unsigned int i;

  peer_id = GNUNET_PEER_search (peer);
  if (0 == peer_id)
  {
    GNUNET_break (0);
    return;
  }
  for (i = 0; i < tunnel->npeers; i++)
    if (tunnel->peers[i]->id == peer_id)
      break;
  if (i == tunnel->npeers)
  {
    GNUNET_break (0);
    return;
  }
  if (NULL != tunnel->disconnect_handler && tunnel->peers[i]->connected == 1)
    tunnel->disconnect_handler (tunnel->cls, peer);
  GNUNET_PEER_change_rc (peer_id, -1);
  GNUNET_free (tunnel->peers[i]);
  tunnel->peers[i] = tunnel->peers[tunnel->npeers - 1];
  GNUNET_array_grow (tunnel->peers, tunnel->npeers, tunnel->npeers - 1);

  msg.header.size = htons (sizeof (struct GNUNET_MESH_PeerControl));
  msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_DEL);
  msg.tunnel_id = htonl (tunnel->tid);
  memcpy (&msg.peer, peer, sizeof (struct GNUNET_PeerIdentity));
  send_packet (tunnel->mesh, &msg.header, tunnel);
}


/**
 * Request that the mesh should try to connect to a peer supporting the given
 * message type.
 *
 * @param tunnel handle to existing tunnel
 * @param app_type application type that must be supported by the peer (MESH
 *                 should discover peer in proximity handling this type)
 */
void
GNUNET_MESH_peer_request_connect_by_type (struct GNUNET_MESH_Tunnel *tunnel,
                                          GNUNET_MESH_ApplicationType app_type)
{
  struct GNUNET_MESH_ConnectPeerByType msg;

  GNUNET_array_append (tunnel->apps, tunnel->napps, app_type);

  LOG (GNUNET_ERROR_TYPE_DEBUG, "* CONNECT BY TYPE *\n");
  msg.header.size = htons (sizeof (struct GNUNET_MESH_ConnectPeerByType));
  msg.header.type = htons (GNUNET_MESSAGE_TYPE_MESH_LOCAL_PEER_ADD_BY_TYPE);
  msg.tunnel_id = htonl (tunnel->tid);
  msg.type = htonl (app_type);
  send_packet (tunnel->mesh, &msg.header, tunnel);
}


/**
 * Ask the mesh to call "notify" once it is ready to transmit the
 * given number of bytes to the specified "target".  If we are not yet
 * connected to the specified peer, a call to this function will cause
 * us to try to establish a connection.
 *
 * @param tunnel tunnel to use for transmission
 * @param cork is corking allowed for this transmission?
 * @param priority how important is the message?
 * @param maxdelay how long can the message wait?
 * @param target destination for the message,
 *               NULL for multicast to all tunnel targets
 * @param notify_size how many bytes of buffer space does notify want?
 * @param notify function to call when buffer space is available;
 *        will be called with NULL on timeout or if the overall queue
 *        for this peer is larger than queue_size and this is currently
 *        the message with the lowest priority
 * @param notify_cls closure for notify
 * @return non-NULL if the notify callback was queued,
 *         NULL if we can not even queue the request (insufficient
 *         memory); if NULL is returned, "notify" will NOT be called.
 */
struct GNUNET_MESH_TransmitHandle *
GNUNET_MESH_notify_transmit_ready (struct GNUNET_MESH_Tunnel *tunnel, int cork,
                                   uint32_t priority,
                                   struct GNUNET_TIME_Relative maxdelay,
                                   const struct GNUNET_PeerIdentity *target,
                                   size_t notify_size,
                                   GNUNET_CONNECTION_TransmitReadyNotify notify,
                                   void *notify_cls)
{
  struct GNUNET_MESH_TransmitHandle *th;
  struct GNUNET_MESH_TransmitHandle *least_priority_th;
  uint32_t least_priority;
  size_t overhead;

  GNUNET_assert (NULL != tunnel);
  LOG (GNUNET_ERROR_TYPE_DEBUG, "mesh notify transmit ready called\n");
  if (NULL != target)
    LOG (GNUNET_ERROR_TYPE_DEBUG, "    target %s\n", GNUNET_i2s (target));
  else
    LOG (GNUNET_ERROR_TYPE_DEBUG, "    target multicast\n");
  GNUNET_assert (NULL != notify);
  if (tunnel->mesh->npackets >= tunnel->mesh->max_queue_size &&
      tunnel->npackets > 0)
  {
    /* queue full */
    if (0 == priority)
      return NULL;
    th = tunnel->mesh->th_tail;
    least_priority = priority;
    least_priority_th = NULL;
    while (NULL != th)
    {
      if (th->priority < least_priority && th->tunnel->npackets > 1)
      {
        least_priority_th = th;
        least_priority = th->priority;
      }
      th = th->prev;
    }
    if (NULL == least_priority_th)
      return NULL;
    /* Can't be a control message */
    GNUNET_assert (NULL != least_priority_th->notify);
    least_priority_th->notify (notify_cls, 0, NULL);
    least_priority_th->tunnel->npackets--;
    tunnel->mesh->npackets--;
    GNUNET_CONTAINER_DLL_remove (tunnel->mesh->th_head, tunnel->mesh->th_tail,
                                 least_priority_th);
    if (GNUNET_SCHEDULER_NO_TASK != least_priority_th->timeout_task)
      GNUNET_SCHEDULER_cancel (least_priority_th->timeout_task);
    GNUNET_free (least_priority_th);
  }
  tunnel->npackets++;
  tunnel->mesh->npackets++;
  th = GNUNET_malloc (sizeof (struct GNUNET_MESH_TransmitHandle));
  th->tunnel = tunnel;
  th->priority = priority;
  th->timeout = GNUNET_TIME_relative_to_absolute (maxdelay);
  th->target = GNUNET_PEER_intern (target);
  if (tunnel->tid >= GNUNET_MESH_LOCAL_TUNNEL_ID_SERV)
    overhead = sizeof (struct GNUNET_MESH_ToOrigin);
  else if (NULL == target)
    overhead = sizeof (struct GNUNET_MESH_Multicast);
  else
    overhead = sizeof (struct GNUNET_MESH_Unicast);
  th->size = notify_size + overhead;
  th->notify = notify;
  th->notify_cls = notify_cls;
  add_to_queue (tunnel->mesh, th);
  if (NULL != tunnel->mesh->th)
    return th;
  tunnel->mesh->th =
      GNUNET_CLIENT_notify_transmit_ready (tunnel->mesh->client, th->size,
                                           GNUNET_TIME_UNIT_FOREVER_REL,
                                           GNUNET_YES, &send_callback,
                                           tunnel->mesh);
  return th;
}


/**
 * Cancel the specified transmission-ready notification.
 *
 * @param th handle that was returned by "notify_transmit_ready".
 */
void
GNUNET_MESH_notify_transmit_ready_cancel (struct GNUNET_MESH_TransmitHandle *th)
{
  struct GNUNET_MESH_Handle *mesh;

  mesh = th->tunnel->mesh;
  if (th->timeout_task != GNUNET_SCHEDULER_NO_TASK)
    GNUNET_SCHEDULER_cancel (th->timeout_task);
  GNUNET_CONTAINER_DLL_remove (mesh->th_head, mesh->th_tail, th);
  GNUNET_free (th);
  if ((NULL == mesh->th_head) && (NULL != mesh->th))
  {
    /* queue empty, no point in asking for transmission */
    GNUNET_CLIENT_notify_transmit_ready_cancel (mesh->th);
    mesh->th = NULL;
  }
}


/**
 * Transition API for tunnel ctx management
 */
void
GNUNET_MESH_tunnel_set_data (struct GNUNET_MESH_Tunnel *tunnel, void *data)
{
  tunnel->ctx = data;
}

/**
 * Transition API for tunnel ctx management
 */
void *
GNUNET_MESH_tunnel_get_data (struct GNUNET_MESH_Tunnel *tunnel)
{
  return tunnel->ctx;
}


#if 0                           /* keep Emacsens' auto-indent happy */
{
#endif
#ifdef __cplusplus
}
#endif