aboutsummaryrefslogtreecommitdiff
path: root/src/arm/gnunet-service-arm.c
blob: 1249fe0030008cc488516bfb4e272aac12b068b9 (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
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
/*
     This file is part of GNUnet.
     (C) 2009, 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 arm/gnunet-service-arm.c
 * @brief the automated restart manager service
 * @author Christian Grothoff
 */
#include "platform.h"
#include "gnunet_util_lib.h"
#include "gnunet_arm_service.h"
#include "gnunet_protocols.h"
#include "arm.h"

/**
 * How many messages do we queue up at most for optional
 * notifications to a client?  (this can cause notifications
 * about outgoing messages to be dropped).
 */
#define MAX_NOTIFY_QUEUE 1024


/**
 * List of our services.
 */
struct ServiceList;


/**
 * Record with information about a listen socket we have open.
 */
struct ServiceListeningInfo
{
  /**
   * This is a linked list.
   */
  struct ServiceListeningInfo *next;

  /**
   * This is a linked list.
   */
  struct ServiceListeningInfo *prev;

  /**
   * Address this socket is listening on.
   */
  struct sockaddr *service_addr;

  /**
   * Service this listen socket is for.
   */
  struct ServiceList *sl;

  /**
   * Number of bytes in 'service_addr'
   */
  socklen_t service_addr_len;

  /**
   * Our listening socket.
   */
  struct GNUNET_NETWORK_Handle *listen_socket;

  /**
   * Task doing the accepting.
   */
  GNUNET_SCHEDULER_TaskIdentifier accept_task;

};


/**
 * List of our services.
 */
struct ServiceList
{
  /**
   * This is a doubly-linked list.
   */
  struct ServiceList *next;

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

  /**
   * Linked list of listen sockets associated with this service.
   */
  struct ServiceListeningInfo *listen_head;

  /**
   * Linked list of listen sockets associated with this service.
   */
  struct ServiceListeningInfo *listen_tail;

  /**
   * Name of the service.
   */
  char *name;

  /**
   * Name of the binary used.
   */
  char *binary;

  /**
   * Name of the configuration file used.
   */
  char *config;

  /**
   * Client to notify upon kill completion (waitpid), NULL
   * if we should simply restart the process.
   */
  struct GNUNET_SERVER_Client *killing_client;

  /**
   * ID of the request that killed the service (for reporting back).
   */
  uint64_t killing_client_request_id;

  /**
   * Process structure pointer of the child.
   */
  struct GNUNET_OS_Process *proc;

  /**
   * Process exponential backoff time
   */
  struct GNUNET_TIME_Relative backoff;

  /**
   * Absolute time at which the process is scheduled to restart in case of death
   */
  struct GNUNET_TIME_Absolute restart_at;

  /**
   * Time we asked the service to shut down (used to calculate time it took
   * the service to terminate).
   */
  struct GNUNET_TIME_Absolute killed_at;

  /**
   * Is this service to be started by default (or did a client tell us explicitly
   * to start it)?  #GNUNET_NO if the service is started only upon 'accept' on a
   * listen socket or possibly explicitly by a client changing the value.
   */
  int is_default;

  /**
   * Should we use pipes to signal this process? (YES for Java binaries and if we
   * are on Windoze).
   */
  int pipe_control;
};

/**
 * List of running services.
 */
static struct ServiceList *running_head;

/**
 * List of running services.
 */
static struct ServiceList *running_tail;

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

/**
 * Command to prepend to each actual command.
 */
static char *prefix_command;

/**
 * Option to append to each actual command.
 */
static char *final_option;

/**
 * ID of task called whenever we get a SIGCHILD.
 */
static GNUNET_SCHEDULER_TaskIdentifier child_death_task;

/**
 * ID of task called whenever the timeout for restarting a child
 * expires.
 */
static GNUNET_SCHEDULER_TaskIdentifier child_restart_task;

/**
 * Pipe used to communicate shutdown via signal.
 */
static struct GNUNET_DISK_PipeHandle *sigpipe;

/**
 * Are we in shutdown mode?
 */
static int in_shutdown;

/**
 * Are we starting user services?
 */
static int start_user = GNUNET_YES;

/**
 * Are we starting system services?
 */
static int start_system = GNUNET_YES;

/**
 * Handle to our server instance.  Our server is a bit special in that
 * its service is not immediately stopped once we get a shutdown
 * request (since we need to continue service until all of our child
 * processes are dead).  This handle is used to shut down the server
 * (and thus trigger process termination) once all child processes are
 * also dead.  A special option in the ARM configuration modifies the
 * behaviour of the service implementation to not do the shutdown
 * immediately.
 */
static struct GNUNET_SERVER_Handle *server;

/**
 * Context for notifications we need to send to our clients.
 */
static struct GNUNET_SERVER_NotificationContext *notifier;


/**
 * Transmit a status result message.
 *
 * @param cls a `unit16_t *` with message type
 * @param size number of bytes available in @a buf
 * @param buf where to copy the message, NULL on error
 * @return number of bytes copied to @a buf
 */
static size_t
write_result (void *cls, size_t size, void *buf)
{
  struct GNUNET_ARM_ResultMessage *msg = cls;
  size_t msize;

  if (NULL == buf)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
		_("Could not send status result to client\n"));
    GNUNET_free (msg);
    return 0;			/* error, not much we can do */
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
	      "Sending status response %u to client\n",
	      (unsigned int) msg->result);
  msize = msg->arm_msg.header.size;
  GNUNET_assert (size >= msize);
  msg->arm_msg.header.size = htons (msg->arm_msg.header.size);
  msg->arm_msg.header.type = htons (msg->arm_msg.header.type);
  msg->result = htonl (msg->result);
  msg->arm_msg.request_id = GNUNET_htonll (msg->arm_msg.request_id);
  memcpy (buf, msg, msize);
  GNUNET_free (msg);
  return msize;
}


/**
 * Transmit the list of running services.
 *
 * @param cls pointer to `struct GNUNET_ARM_ListResultMessage` with the message
 * @param size number of bytes available in @a buf
 * @param buf where to copy the message, NULL on error
 * @return number of bytes copied to @a buf
 */
static size_t
write_list_result (void *cls, size_t size, void *buf)
{
  struct GNUNET_ARM_ListResultMessage *msg = cls;
  size_t rslt_size;

  if (NULL == buf)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _("Could not send list result to client\n"));
    GNUNET_free (msg);
    return 0;                   /* error, not much we can do */
  }

  rslt_size = msg->arm_msg.header.size;
  GNUNET_assert (size >= rslt_size);
  msg->arm_msg.header.size = htons (msg->arm_msg.header.size);
  msg->arm_msg.header.type = htons (msg->arm_msg.header.type);
  msg->arm_msg.request_id = GNUNET_htonll (msg->arm_msg.request_id);
  msg->count = htons (msg->count);

  memcpy (buf, msg, rslt_size);
  GNUNET_free (msg);
  return rslt_size;
}


/**
 * Signal our client that we will start or stop the
 * service.
 *
 * @param client who is being signalled
 * @param name name of the service
 * @param request_id id of the request that is being responded to.
 * @param result message type to send
 * @return NULL if it was not found
 */
static void
signal_result (struct GNUNET_SERVER_Client *client,
	       const char *name,
	       uint64_t request_id,
	       enum GNUNET_ARM_Result result)
{
  struct GNUNET_ARM_ResultMessage *msg;
  size_t msize;

  msize = sizeof (struct GNUNET_ARM_ResultMessage);
  msg = GNUNET_malloc (msize);
  msg->arm_msg.header.size = msize;
  msg->arm_msg.header.type = GNUNET_MESSAGE_TYPE_ARM_RESULT;
  msg->result = result;
  msg->arm_msg.request_id = request_id;

  GNUNET_SERVER_notify_transmit_ready (client, msize,
				       GNUNET_TIME_UNIT_FOREVER_REL,
				       write_result, msg);
}


/**
 * Tell all clients about status change of a service.
 *
 * @param name name of the service
 * @param status message type to send
 * @param unicast if not NULL, send to this client only.
 *                otherwise, send to all clients in the notifier
 */
static void
broadcast_status (const char *name,
		  enum GNUNET_ARM_ServiceStatus status,
		  struct GNUNET_SERVER_Client *unicast)
{
  struct GNUNET_ARM_StatusMessage *msg;
  size_t namelen;

  if (NULL == notifier)
    return;
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
      "Sending status %u of service `%s' to client\n",
      (unsigned int) status, name);
  namelen = strlen (name);
  msg = GNUNET_malloc (sizeof (struct GNUNET_ARM_StatusMessage) + namelen + 1);
  msg->header.size = htons (sizeof (struct GNUNET_ARM_StatusMessage) + namelen + 1);
  msg->header.type = htons (GNUNET_MESSAGE_TYPE_ARM_STATUS);
  msg->status = htonl ((uint32_t) (status));
  memcpy ((char *) &msg[1], name, namelen + 1);

  if (NULL == unicast)
    GNUNET_SERVER_notification_context_broadcast (notifier,
        (struct GNUNET_MessageHeader *) msg, GNUNET_YES);
  else
    GNUNET_SERVER_notification_context_unicast (notifier, unicast,
        (const struct GNUNET_MessageHeader *) msg, GNUNET_NO);
  GNUNET_free (msg);
}


/**
 * Actually start the process for the given service.
 *
 * @param sl identifies service to start
 * @param client that asked to start the service (may be NULL)
 * @param request_id id of the request in response to which the process is
 *                   being started. 0 if starting was not requested.
 */
static void
start_process (struct ServiceList *sl,
               struct GNUNET_SERVER_Client *client,
               uint64_t request_id)
{
  char *loprefix;
  char *options;
  char *optpos;
  char *optend;
  const char *next;
  int use_debug;
  char b;
  char *val;
  struct ServiceListeningInfo *sli;
  SOCKTYPE *lsocks;
  unsigned int ls;
  char *binary;
  char *quotedbinary;

  /* calculate listen socket list */
  lsocks = NULL;
  ls = 0;
  for (sli = sl->listen_head; NULL != sli; sli = sli->next)
    {
      GNUNET_array_append (lsocks, ls,
			   GNUNET_NETWORK_get_fd (sli->listen_socket));
      if (sli->accept_task != GNUNET_SCHEDULER_NO_TASK)
	{
	  GNUNET_SCHEDULER_cancel (sli->accept_task);
	  sli->accept_task = GNUNET_SCHEDULER_NO_TASK;
	}
    }
#if WINDOWS
  GNUNET_array_append (lsocks, ls, INVALID_SOCKET);
#else
  GNUNET_array_append (lsocks, ls, -1);
#endif

  /* obtain configuration */
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, sl->name, "PREFIX",
					     &loprefix))
    loprefix = GNUNET_strdup (prefix_command);
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, sl->name, "OPTIONS",
					     &options))
    {
      options = GNUNET_strdup (final_option);
      if (NULL == strstr (options, "%"))
	{
	  /* replace '{}' with service name */
	  while (NULL != (optpos = strstr (options, "{}")))
	    {
	      optpos[0] = '%';
	      optpos[1] = 's';
	      GNUNET_asprintf (&optpos, options, sl->name);
	      GNUNET_free (options);
	      options = optpos;
	    }
	  /* replace '$PATH' with value associated with "PATH" */
	  while (NULL != (optpos = strstr (options, "$")))
	    {
	      optend = optpos + 1;
	      while (isupper ((unsigned char) *optend))
		optend++;
	      b = *optend;
	      if ('\0' == b)
		next = "";
	      else
		next = optend + 1;
	      *optend = '\0';
	      if (GNUNET_OK !=
		  GNUNET_CONFIGURATION_get_value_string (cfg, "PATHS",
							 optpos + 1, &val))
		val = GNUNET_strdup ("");
	      *optpos = '\0';
	      GNUNET_asprintf (&optpos, "%s%s%c%s", options, val, b, next);
	      GNUNET_free (options);
	      GNUNET_free (val);
	      options = optpos;
	    }
	}
    }
  use_debug = GNUNET_CONFIGURATION_get_value_yesno (cfg, sl->name, "DEBUG");

  /* actually start process */
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
	      "Starting service `%s' using binary `%s' and configuration `%s'\n",
	      sl->name, sl->binary, sl->config);
  binary = GNUNET_OS_get_libexec_binary_path (sl->binary);
  GNUNET_asprintf (&quotedbinary,
		   "\"%s\"",
		   binary);

  GNUNET_assert (NULL == sl->proc);
  if (GNUNET_YES == use_debug)
  {
    if (NULL == sl->config)
      sl->proc =
	GNUNET_OS_start_process_s (sl->pipe_control,
                                   GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                   lsocks, loprefix, quotedbinary, "-L",
                                   "DEBUG", options, NULL);
    else
      sl->proc =
          GNUNET_OS_start_process_s (sl->pipe_control,
                                     GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                     lsocks, loprefix, quotedbinary, "-c",
                                     sl->config, "-L",
                                     "DEBUG", options, NULL);
  }
  else
  {
    if (NULL == sl->config)
      sl->proc =
          GNUNET_OS_start_process_s (sl->pipe_control,
                                     GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                     lsocks, loprefix, quotedbinary,
                                     options, NULL);
    else
      sl->proc =
          GNUNET_OS_start_process_s (sl->pipe_control,
                                     GNUNET_OS_INHERIT_STD_OUT_AND_ERR,
                                     lsocks, loprefix, quotedbinary, "-c",
                                     sl->config, options, NULL);
  }
  GNUNET_free (binary);
  GNUNET_free (quotedbinary);
  if (sl->proc == NULL)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _("Failed to start service `%s'\n"),
		sl->name);
    if (client)
      signal_result (client,
                     sl->name,
                     request_id,
                     GNUNET_ARM_RESULT_START_FAILED);
  }
  else
  {
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _("Starting service `%s'\n"),
		sl->name);
    broadcast_status (sl->name, GNUNET_ARM_SERVICE_STARTING, NULL);
    if (client)
      signal_result (client, sl->name, request_id, GNUNET_ARM_RESULT_STARTING);
  }
  /* clean up */
  GNUNET_free (loprefix);
  GNUNET_free (options);
  GNUNET_array_grow (lsocks, ls, 0);
}


/**
 * Find the process with the given service
 * name in the given list and return it.
 *
 * @param name which service entry to look up
 * @return NULL if it was not found
 */
static struct ServiceList *
find_service (const char *name)
{
  struct ServiceList *sl;

  sl = running_head;
  while (sl != NULL)
    {
      if (0 == strcasecmp (sl->name, name))
	return sl;
      sl = sl->next;
    }
  return NULL;
}


/**
 * First connection has come to the listening socket associated with the service,
 * create the service in order to relay the incoming connection to it
 *
 * @param cls callback data, `struct ServiceListeningInfo` describing a listen socket
 * @param tc context
 */
static void
accept_connection (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct ServiceListeningInfo *sli = cls;
  struct ServiceList *sl = sli->sl;

  sli->accept_task = GNUNET_SCHEDULER_NO_TASK;
  GNUNET_assert (GNUNET_NO == in_shutdown);
  if (0 != (GNUNET_SCHEDULER_REASON_SHUTDOWN & tc->reason))
    return;
  start_process (sl, NULL, 0);
}


/**
 * Creating a listening socket for each of the service's addresses and
 * wait for the first incoming connection to it
 *
 * @param sa address associated with the service
 * @param addr_len length of @a sa
 * @param sl service entry for the service in question
 */
static void
create_listen_socket (struct sockaddr *sa, socklen_t addr_len,
		      struct ServiceList *sl)
{
  static int on = 1;
  struct GNUNET_NETWORK_Handle *sock;
  struct ServiceListeningInfo *sli;
#ifndef WINDOWS
  int match_uid;
  int match_gid;
#endif

  switch (sa->sa_family)
  {
  case AF_INET:
    sock = GNUNET_NETWORK_socket_create (PF_INET, SOCK_STREAM, 0);
    break;
  case AF_INET6:
    sock = GNUNET_NETWORK_socket_create (PF_INET6, SOCK_STREAM, 0);
    break;
  case AF_UNIX:
    if (strcmp (GNUNET_a2s (sa, addr_len), "@") == 0)	/* Do not bind to blank UNIX path! */
      return;
    sock = GNUNET_NETWORK_socket_create (PF_UNIX, SOCK_STREAM, 0);
    break;
  default:
    GNUNET_break (0);
    sock = NULL;
    errno = EAFNOSUPPORT;
    break;
  }
  if (NULL == sock)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                _("Unable to create socket for service `%s': %s\n"),
                sl->name, STRERROR (errno));
    GNUNET_free (sa);
    return;
  }
  if (GNUNET_NETWORK_socket_setsockopt
      (sock, SOL_SOCKET, SO_REUSEADDR, &on, sizeof (on)) != GNUNET_OK)
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
			 "setsockopt");
#ifdef IPV6_V6ONLY
  if ((sa->sa_family == AF_INET6) &&
      (GNUNET_NETWORK_socket_setsockopt
       (sock, IPPROTO_IPV6, IPV6_V6ONLY, &on, sizeof (on)) != GNUNET_OK))
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR | GNUNET_ERROR_TYPE_BULK,
			 "setsockopt");
#endif

  if (GNUNET_OK !=
      GNUNET_NETWORK_socket_bind (sock, (const struct sockaddr *) sa, addr_len))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_WARNING,
                _
                ("Unable to bind listening socket for service `%s' to address `%s': %s\n"),
                sl->name, GNUNET_a2s (sa, addr_len), STRERROR (errno));
    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
    GNUNET_free (sa);
    return;
  }
#ifndef WINDOWS
  if ((AF_UNIX == sa->sa_family)
#ifdef LINUX
      /* Permission settings are not required when abstract sockets are used */
      && ('\0' != ((const struct sockaddr_un *)sa)->sun_path[0])
#endif      
      )
  {
    match_uid =
      GNUNET_CONFIGURATION_get_value_yesno (cfg, sl->name,
                                            "UNIX_MATCH_UID");
    match_gid =
      GNUNET_CONFIGURATION_get_value_yesno (cfg, sl->name,
                                            "UNIX_MATCH_GID");
    GNUNET_DISK_fix_permissions (((const struct sockaddr_un *)sa)->sun_path,
                                 match_uid,
                                 match_gid);

  }
#endif
  if (GNUNET_NETWORK_socket_listen (sock, 5) != GNUNET_OK)
  {
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "listen");
    GNUNET_break (GNUNET_OK == GNUNET_NETWORK_socket_close (sock));
    GNUNET_free (sa);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
	      _("ARM now monitors connections to service `%s' at `%s'\n"),
	      sl->name, GNUNET_a2s (sa, addr_len));
  sli = GNUNET_new (struct ServiceListeningInfo);
  sli->service_addr = sa;
  sli->service_addr_len = addr_len;
  sli->listen_socket = sock;
  sli->sl = sl;
  sli->accept_task =
    GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL, sock,
				   &accept_connection, sli);
  GNUNET_CONTAINER_DLL_insert (sl->listen_head, sl->listen_tail, sli);
}


/**
 * Remove and free an entry in the service list.  Listen sockets
 * must have already been cleaned up.  Only to be called during shutdown.
 *
 * @param sl entry to free
 */
static void
free_service (struct ServiceList *sl)
{
  GNUNET_assert (GNUNET_YES == in_shutdown);
  GNUNET_CONTAINER_DLL_remove (running_head, running_tail, sl);
  GNUNET_assert (NULL == sl->listen_head);
  GNUNET_free_non_null (sl->config);
  GNUNET_free_non_null (sl->binary);
  GNUNET_free (sl->name);
  GNUNET_free (sl);
}


/**
 * Handle START-message.
 *
 * @param cls closure (always NULL)
 * @param client identification of the client
 * @param message the actual message
 * @return #GNUNET_OK to keep the connection open,
 *         #GNUNET_SYSERR to close it (signal serious error)
 */
static void
handle_start (void *cls, struct GNUNET_SERVER_Client *client,
	      const struct GNUNET_MessageHeader *message)
{
  const char *servicename;
  struct ServiceList *sl;
  uint16_t size;
  uint64_t request_id;
  struct GNUNET_ARM_Message *amsg;

  amsg = (struct GNUNET_ARM_Message *) message;
  request_id = GNUNET_ntohll (amsg->request_id);
  size = ntohs (amsg->header.size);
  size -= sizeof (struct GNUNET_ARM_Message);
  servicename = (const char *) &amsg[1];
  if ((size == 0) || (servicename[size - 1] != '\0'))
  {
    GNUNET_break (0);
    GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
    return;
  }
  if (GNUNET_YES == in_shutdown)
  {
    signal_result (client, servicename, request_id,
		   GNUNET_ARM_RESULT_IN_SHUTDOWN);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
    return;
  }
  sl = find_service (servicename);
  if (NULL == sl)
  {
    signal_result (client, servicename, request_id,
		   GNUNET_ARM_RESULT_IS_NOT_KNOWN);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
    return;
  }
  sl->is_default = GNUNET_YES;
  if (NULL != sl->proc)
  {
    signal_result (client, servicename, request_id,
		   GNUNET_ARM_RESULT_IS_STARTED_ALREADY);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
    return;
  }
  start_process (sl, client, request_id);
  GNUNET_SERVER_receive_done (client, GNUNET_OK);
}


/**
 * Start a shutdown sequence.
 *
 * @param cls closure (refers to service)
 * @param tc task context
 */
static void
trigger_shutdown (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Triggering shutdown\n");
  GNUNET_SCHEDULER_shutdown ();
}


/**
 * Handle STOP-message.
 *
 * @param cls closure (always NULL)
 * @param client identification of the client
 * @param message the actual message
 * @return #GNUNET_OK to keep the connection open,
 *         #GNUNET_SYSERR to close it (signal serious error)
 */
static void
handle_stop (void *cls, struct GNUNET_SERVER_Client *client,
	     const struct GNUNET_MessageHeader *message)
{
  struct ServiceList *sl;
  const char *servicename;
  uint16_t size;
  uint64_t request_id;
  struct GNUNET_ARM_Message *amsg;

  amsg = (struct GNUNET_ARM_Message *) message;
  request_id = GNUNET_ntohll (amsg->request_id);
  size = ntohs (amsg->header.size);
  size -= sizeof (struct GNUNET_ARM_Message);
  servicename = (const char *) &amsg[1];
  if ((size == 0) || (servicename[size - 1] != '\0'))
    {
      GNUNET_break (0);
      GNUNET_SERVER_receive_done (client, GNUNET_SYSERR);
      return;
    }
  GNUNET_log (GNUNET_ERROR_TYPE_INFO,
	      _("Preparing to stop `%s'\n"),
	      servicename);
  if (0 == strcasecmp (servicename, "arm"))
  {
    broadcast_status (servicename, GNUNET_ARM_SERVICE_STOPPING, NULL);
    signal_result (client, servicename, request_id, GNUNET_ARM_RESULT_STOPPING);
    GNUNET_SERVER_client_persist_ (client);
    GNUNET_SCHEDULER_add_now (trigger_shutdown, NULL);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
    return;
  }
  sl = find_service (servicename);
  if (sl == NULL)
    {
      signal_result (client, servicename, request_id, GNUNET_ARM_RESULT_IS_NOT_KNOWN);
      GNUNET_SERVER_receive_done (client, GNUNET_OK);
      return;
    }
  sl->is_default = GNUNET_NO;
  if (GNUNET_YES == in_shutdown)
    {
      /* shutdown in progress */
      signal_result (client, servicename, request_id, GNUNET_ARM_RESULT_IN_SHUTDOWN);
      GNUNET_SERVER_receive_done (client, GNUNET_OK);
      return;
    }
  if (NULL != sl->killing_client)
  {
    /* killing already in progress */
    signal_result (client, servicename, request_id,
		   GNUNET_ARM_RESULT_IS_STOPPING_ALREADY);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
    return;
  }
  if (NULL == sl->proc)
  {
    /* process is down */
    signal_result (client, servicename, request_id,
		   GNUNET_ARM_RESULT_IS_STOPPED_ALREADY);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
    return;
  }
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
	      "Sending kill signal to service `%s', waiting for process to die.\n",
	      servicename);
  broadcast_status (servicename, GNUNET_ARM_SERVICE_STOPPING, NULL);
  /* no signal_start - only when it's STOPPED */
  sl->killed_at = GNUNET_TIME_absolute_get ();
  if (0 != GNUNET_OS_process_kill (sl->proc, GNUNET_TERM_SIG))
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
  sl->killing_client = client;
  sl->killing_client_request_id = request_id;
  GNUNET_SERVER_client_keep (client);
  GNUNET_SERVER_receive_done (client, GNUNET_OK);
}


/**
 * Handle LIST-message.
 *
 * @param cls closure (always NULL)
 * @param client identification of the client
 * @param message the actual message
 */
static void
handle_list (void *cls, struct GNUNET_SERVER_Client *client,
             const struct GNUNET_MessageHeader *message)
{
  struct GNUNET_ARM_ListResultMessage *msg;
  struct GNUNET_ARM_Message *request;
  size_t string_list_size;
  size_t total_size;
  struct ServiceList *sl;
  uint16_t count;

  if (NULL == client)
    return;

  request = (struct GNUNET_ARM_Message *) message;
  GNUNET_break (0 == ntohl (request->reserved));
  count = 0;
  string_list_size = 0;
  /* first count the running processes get their name's size */
  for (sl = running_head; NULL != sl; sl = sl->next)
  {
    if (NULL != sl->proc)
    {
      string_list_size += strlen (sl->name);
      string_list_size += strlen (sl->binary);
      string_list_size += 4;
      count++;
    }
  }

  total_size = sizeof (struct GNUNET_ARM_ListResultMessage)
               + string_list_size;
  msg = GNUNET_malloc (total_size);
  msg->arm_msg.header.size = total_size;
  msg->arm_msg.header.type = GNUNET_MESSAGE_TYPE_ARM_LIST_RESULT;
  msg->arm_msg.reserved = htonl (0);
  msg->arm_msg.request_id = GNUNET_ntohll (request->request_id);
  msg->count = count;

  char *pos = (char *)&msg[1];
  for (sl = running_head; NULL != sl; sl = sl->next)
  {
    if (NULL != sl->proc)
    {
      size_t s = strlen (sl->name) + strlen (sl->binary) + 4;
      GNUNET_snprintf (pos, s, "%s (%s)", sl->name, sl->binary);
      pos += s;
    }
  }
  GNUNET_SERVER_notify_transmit_ready (client,
                                       total_size,
                                       GNUNET_TIME_UNIT_FOREVER_REL,
                                       &write_list_result, msg);
  GNUNET_SERVER_receive_done (client, GNUNET_OK);
}


/**
 * We are done with everything.  Stop remaining
 * tasks, signal handler and the server.
 */
static void
do_shutdown ()
{
  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Last shutdown phase\n");
  if (NULL != notifier)
  {
    GNUNET_SERVER_notification_context_destroy (notifier);
    notifier = NULL;
  }
  if (NULL != server)
    {
      GNUNET_SERVER_destroy (server);
      server = NULL;
    }
  if (GNUNET_SCHEDULER_NO_TASK != child_death_task)
    {
      GNUNET_SCHEDULER_cancel (child_death_task);
      child_death_task = GNUNET_SCHEDULER_NO_TASK;
    }
}


/**
 * Count how many services are still active.
 *
 * @param running_head list of services
 * @return number of active services found
 */
static unsigned int
list_count (struct ServiceList *running_head)
{
  struct ServiceList *i;
  unsigned int res = 0;

  for (res = 0, i = running_head; i; i = i->next, res++)
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		"%s\n",
		i->name);
  return res;
}


/**
 * Task run for shutdown.
 *
 * @param cls closure, NULL if we need to self-restart
 * @param tc context
 */
static void
shutdown_task (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct ServiceList *pos;
  struct ServiceList *nxt;
  struct ServiceListeningInfo *sli;

  GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
	      "First shutdown phase\n");
  if (GNUNET_SCHEDULER_NO_TASK != child_restart_task)
  {
    GNUNET_SCHEDULER_cancel (child_restart_task);
    child_restart_task = GNUNET_SCHEDULER_NO_TASK;
  }
  in_shutdown = GNUNET_YES;
  /* first, stop listening */
  for (pos = running_head; NULL != pos; pos = pos->next)
  {
    while (NULL != (sli = pos->listen_head))
      {
	GNUNET_CONTAINER_DLL_remove (pos->listen_head,
				     pos->listen_tail, sli);
	if (sli->accept_task != GNUNET_SCHEDULER_NO_TASK)
	  {
	    GNUNET_SCHEDULER_cancel (sli->accept_task);
	    sli->accept_task = GNUNET_SCHEDULER_NO_TASK;
	  }
	GNUNET_break (GNUNET_OK ==
		      GNUNET_NETWORK_socket_close (sli->listen_socket));
	GNUNET_free (sli->service_addr);
	GNUNET_free (sli);
      }
  }
  /* then, shutdown all existing service processes */
  nxt = running_head;
  while (NULL != (pos = nxt))
  {
    nxt = pos->next;
    if (pos->proc != NULL)
    {
      GNUNET_log (GNUNET_ERROR_TYPE_INFO,
		  "Stopping service `%s'\n",
		  pos->name);
      pos->killed_at = GNUNET_TIME_absolute_get ();
      if (0 != GNUNET_OS_process_kill (pos->proc, GNUNET_TERM_SIG))
	GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "kill");
    }
    else
    {
      free_service (pos);
    }
  }
  /* finally, should all service processes be already gone, terminate for real */
  if (running_head == NULL)
    do_shutdown ();
  else
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		"Delaying shutdown, have %u childs still running\n",
		list_count (running_head));
}


/**
 * Task run whenever it is time to restart a child that died.
 *
 * @param cls closure, always NULL
 * @param tc context
 */
static void
delayed_restart_task (void *cls,
		      const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct ServiceList *sl;
  struct GNUNET_TIME_Relative lowestRestartDelay;
  struct ServiceListeningInfo *sli;

  child_restart_task = GNUNET_SCHEDULER_NO_TASK;
  if (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
    return;
  GNUNET_assert (GNUNET_NO == in_shutdown);
  lowestRestartDelay = GNUNET_TIME_UNIT_FOREVER_REL;

  /* check for services that need to be restarted due to
   * configuration changes or because the last restart failed */
  for (sl = running_head; NULL != sl; sl = sl->next)
  {
    if (NULL != sl->proc)
      continue;
    /* service is currently not running */
    if (0 == GNUNET_TIME_absolute_get_remaining (sl->restart_at).rel_value_us)
    {
      /* restart is now allowed */
      if (sl->is_default)
      {
	/* process should run by default, start immediately */
	GNUNET_log (GNUNET_ERROR_TYPE_INFO,
		    _("Restarting service `%s'.\n"), sl->name);
	start_process (sl, NULL, 0);
      }
      else
      {
	/* process is run on-demand, ensure it is re-started if there is demand */
	for (sli = sl->listen_head; NULL != sli; sli = sli->next)
	  if (GNUNET_SCHEDULER_NO_TASK == sli->accept_task)
	  {
	    /* accept was actually paused, so start it again */
	    sli->accept_task =
	      GNUNET_SCHEDULER_add_read_net
	      (GNUNET_TIME_UNIT_FOREVER_REL, sli->listen_socket,
	       &accept_connection, sli);
	  }
      }
    }
    else
    {
      /* update calculation for earliest time to reactivate a service */
      lowestRestartDelay =
	GNUNET_TIME_relative_min (lowestRestartDelay,
				  GNUNET_TIME_absolute_get_remaining
				  (sl->restart_at));
    }
  }
  if (lowestRestartDelay.rel_value_us != GNUNET_TIME_UNIT_FOREVER_REL.rel_value_us)
  {
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
		"Will restart process in %s\n",
		GNUNET_STRINGS_relative_time_to_string (lowestRestartDelay, GNUNET_YES));
    child_restart_task =
      GNUNET_SCHEDULER_add_delayed_with_priority (lowestRestartDelay,
						  GNUNET_SCHEDULER_PRIORITY_IDLE,
						  &delayed_restart_task, NULL);
  }
}


/**
 * Task triggered whenever we receive a SIGCHLD (child
 * process died).
 *
 * @param cls closure, NULL if we need to self-restart
 * @param tc context
 */
static void
maint_child_death (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
{
  struct ServiceList *pos;
  struct ServiceList *next;
  struct ServiceListeningInfo *sli;
  const char *statstr;
  int statcode;
  int ret;
  char c[16];
  enum GNUNET_OS_ProcessStatusType statusType;
  unsigned long statusCode;
  const struct GNUNET_DISK_FileHandle *pr;

  pr = GNUNET_DISK_pipe_handle (sigpipe, GNUNET_DISK_PIPE_END_READ);
  child_death_task = GNUNET_SCHEDULER_NO_TASK;
  if (0 == (tc->reason & GNUNET_SCHEDULER_REASON_READ_READY))
    {
      /* shutdown scheduled us, ignore! */
      child_death_task =
	GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
					pr, &maint_child_death, NULL);
      return;
    }
  /* consume the signal */
  GNUNET_break (0 < GNUNET_DISK_file_read (pr, &c, sizeof (c)));

  /* check for services that died (WAITPID) */
  next = running_head;
  while (NULL != (pos = next))
    {
      next = pos->next;

      if (pos->proc == NULL)
      {
	if (GNUNET_YES == in_shutdown)
	  free_service (pos);
	continue;
      }
      if ((GNUNET_SYSERR ==
	   (ret =
	    GNUNET_OS_process_status (pos->proc, &statusType, &statusCode)))
	  || ((ret == GNUNET_NO) || (statusType == GNUNET_OS_PROCESS_STOPPED)
	      || (statusType == GNUNET_OS_PROCESS_RUNNING)))
	continue;
      if (statusType == GNUNET_OS_PROCESS_EXITED)
      {
	statstr = _( /* process termination method */ "exit");
	statcode = statusCode;
      }
      else if (statusType == GNUNET_OS_PROCESS_SIGNALED)
      {
	statstr = _( /* process termination method */ "signal");
	statcode = statusCode;
      }
      else
      {
	statstr = _( /* process termination method */ "unknown");
	statcode = 0;
      }
      if (0 != pos->killed_at.abs_value_us)
      {
	GNUNET_log (GNUNET_ERROR_TYPE_INFO,
		    _("Service `%s' took %s to terminate\n"),
		    pos->name,
		    GNUNET_STRINGS_relative_time_to_string (GNUNET_TIME_absolute_get_duration (pos->killed_at), GNUNET_YES));
      }
      GNUNET_OS_process_destroy (pos->proc);
      pos->proc = NULL;
      broadcast_status (pos->name, GNUNET_ARM_SERVICE_STOPPED, NULL);
      if (NULL != pos->killing_client)
      {
        signal_result (pos->killing_client, pos->name,
            pos->killing_client_request_id, GNUNET_ARM_RESULT_STOPPED);
        GNUNET_SERVER_client_drop (pos->killing_client);
        pos->killing_client = NULL;
        pos->killing_client_request_id = 0;
      }
      if (GNUNET_YES != in_shutdown)
      {
        if ((statusType == GNUNET_OS_PROCESS_EXITED) && (statcode == 0))
        {
          /* process terminated normally, allow restart at any time */
          pos->restart_at.abs_value_us = 0;
          GNUNET_log (GNUNET_ERROR_TYPE_INFO,
              _("Service `%s' terminated normally, will restart at any time\n"),
              pos->name);
          /* process can still be re-started on-demand, ensure it is re-started if there is demand */
          for (sli = pos->listen_head; NULL != sli; sli = sli->next)
          {
            GNUNET_break (GNUNET_SCHEDULER_NO_TASK == sli->accept_task);
            sli->accept_task =
                GNUNET_SCHEDULER_add_read_net (GNUNET_TIME_UNIT_FOREVER_REL,
                    sli->listen_socket, &accept_connection, sli);
          }
	}
        else
        {
	  if (0 == (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN))
	    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
	        _("Service `%s' terminated with status %s/%d, will restart in %s\n"),
                pos->name, statstr, statcode,
                GNUNET_STRINGS_relative_time_to_string (pos->backoff, GNUNET_YES));
	  /* schedule restart */
	  pos->restart_at = GNUNET_TIME_relative_to_absolute (pos->backoff);
	  pos->backoff = GNUNET_TIME_STD_BACKOFF (pos->backoff);
          if (GNUNET_SCHEDULER_NO_TASK != child_restart_task)
            GNUNET_SCHEDULER_cancel (child_restart_task);
          child_restart_task = GNUNET_SCHEDULER_add_with_priority (
            GNUNET_SCHEDULER_PRIORITY_IDLE, &delayed_restart_task, NULL);
        }
      }
      else
      {
        free_service (pos);
      }
    }
  child_death_task = GNUNET_SCHEDULER_add_read_file (
      GNUNET_TIME_UNIT_FOREVER_REL, pr, &maint_child_death, NULL);
  if ((NULL == running_head) && (GNUNET_YES == in_shutdown))
    do_shutdown ();
  else if (GNUNET_YES == in_shutdown)
    GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
        "Delaying shutdown after child's death, still have %u children\n",
        list_count (running_head));

}


/**
 * Signal handler called for SIGCHLD.  Triggers the
 * respective handler by writing to the trigger pipe.
 */
static void
sighandler_child_death ()
{
  static char c;
  int old_errno = errno;	/* back-up errno */

  GNUNET_break (1 ==
		GNUNET_DISK_file_write (GNUNET_DISK_pipe_handle
					(sigpipe, GNUNET_DISK_PIPE_END_WRITE),
					&c, sizeof (c)));
  errno = old_errno;		/* restore errno */
}


/**
 * Setup our service record for the given section in the configuration file
 * (assuming the section is for a service).
 *
 * @param cls unused
 * @param section a section in the configuration file
 * @return #GNUNET_OK (continue)
 */
static void
setup_service (void *cls, const char *section)
{
  struct ServiceList *sl;
  char *binary;
  char *config;
  struct stat sbuf;
  struct sockaddr **addrs;
  socklen_t *addr_lens;
  int ret;
  unsigned int i;

  if (strcasecmp (section, "arm") == 0)
    return;
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, section, "BINARY", &binary))
  {
    /* not a service section */
    return;
  }
  if ((GNUNET_YES ==
       GNUNET_CONFIGURATION_have_value (cfg, section, "USER_SERVICE")) &&
      (GNUNET_YES ==
       GNUNET_CONFIGURATION_get_value_yesno (cfg, section, "USER_SERVICE")))
  {
    if (GNUNET_NO == start_user)
    {
      GNUNET_free (binary);
      return; /* user service, and we don't deal with those */
    }
  }
  else
  {
    if (GNUNET_NO == start_system)
    {
      GNUNET_free (binary);
      return; /* system service, and we don't deal with those */
    }
  }
  sl = find_service (section);
  if (NULL != sl)
  {
    /* got the same section twice!? */
    GNUNET_break (0);
    GNUNET_free (binary);
    return;
  }
  config = NULL;
  if (( (GNUNET_OK !=
	 GNUNET_CONFIGURATION_get_value_filename (cfg, section, "CONFIG",
						  &config)) &&
	(GNUNET_OK !=
	 GNUNET_CONFIGURATION_get_value_filename (cfg, "PATHS", "DEFAULTCONFIG",
						  &config)) ) ||
      (0 != STAT (config, &sbuf)))
  {
    if (NULL != config)
    {
      GNUNET_log_config_invalid (GNUNET_ERROR_TYPE_WARNING,
				 section, "CONFIG",
				 STRERROR (errno));
      GNUNET_free (config);
      config = NULL;
    }
  }
  sl = GNUNET_new (struct ServiceList);
  sl->name = GNUNET_strdup (section);
  sl->binary = binary;
  sl->config = config;
  sl->backoff = GNUNET_TIME_UNIT_MILLISECONDS;
  sl->restart_at = GNUNET_TIME_UNIT_FOREVER_ABS;
#if WINDOWS
  sl->pipe_control = GNUNET_YES;
#else
  if (GNUNET_CONFIGURATION_have_value (cfg, section, "PIPECONTROL"))
    sl->pipe_control = GNUNET_CONFIGURATION_get_value_yesno (cfg, section, "PIPECONTROL");
#endif
  GNUNET_CONTAINER_DLL_insert (running_head, running_tail, sl);

  if (GNUNET_YES !=
      GNUNET_CONFIGURATION_get_value_yesno (cfg, section, "AUTOSTART"))
    return;
  if (0 >= (ret = GNUNET_SERVICE_get_server_addresses (section, cfg,
						       &addrs, &addr_lens)))
    return;
  /* this will free (or capture) addrs[i] */
  for (i = 0; i < ret; i++)
    create_listen_socket (addrs[i], addr_lens[i], sl);
  GNUNET_free (addrs);
  GNUNET_free (addr_lens);
}


/**
 * A client connected, add it to the notification context.
 *
 * @param cls closure
 * @param client identification of the client
 */
static void
handle_client_connecting (void *cls, struct GNUNET_SERVER_Client *client)
{
  /* All clients are considered to be of the "monitor" kind
   * (that is, they don't affect ARM shutdown).
   */
  if (NULL != client)
    GNUNET_SERVER_client_mark_monitor (client);
}


/**
 * Handle MONITOR-message.
 *
 * @param cls closure (always NULL)
 * @param client identification of the client
 * @param message the actual message
 * @return #GNUNET_OK to keep the connection open,
 *         #GNUNET_SYSERR to close it (signal serious error)
 */
static void
handle_monitor (void *cls, struct GNUNET_SERVER_Client *client,
	     const struct GNUNET_MessageHeader *message)
{
  /* Removal is handled by the server implementation, internally. */
  if ((NULL != client) && (NULL != notifier))
  {
    GNUNET_SERVER_notification_context_add (notifier, client);
    broadcast_status ("arm", GNUNET_ARM_SERVICE_MONITORING_STARTED, client);
    GNUNET_SERVER_receive_done (client, GNUNET_OK);
  }
}


/**
 * Process arm requests.
 *
 * @param cls closure
 * @param serv the initialized server
 * @param c configuration to use
 */
static void
run (void *cls, struct GNUNET_SERVER_Handle *serv,
     const struct GNUNET_CONFIGURATION_Handle *c)
{
  static const struct GNUNET_SERVER_MessageHandler handlers[] = {
    {&handle_start, NULL, GNUNET_MESSAGE_TYPE_ARM_START, 0},
    {&handle_stop, NULL, GNUNET_MESSAGE_TYPE_ARM_STOP, 0},
    {&handle_monitor, NULL, GNUNET_MESSAGE_TYPE_ARM_MONITOR,
     sizeof (struct GNUNET_MessageHeader)},
    {&handle_list, NULL, GNUNET_MESSAGE_TYPE_ARM_LIST,
     sizeof (struct GNUNET_ARM_Message)},
    {NULL, NULL, 0, 0}
  };
  char *defaultservices;
  const char *pos;
  struct ServiceList *sl;

  cfg = c;
  server = serv;
  GNUNET_assert (NULL != serv);
  GNUNET_SCHEDULER_add_delayed (GNUNET_TIME_UNIT_FOREVER_REL,
                                &shutdown_task,
				NULL);
  child_death_task =
    GNUNET_SCHEDULER_add_read_file (GNUNET_TIME_UNIT_FOREVER_REL,
				    GNUNET_DISK_pipe_handle (sigpipe,
							     GNUNET_DISK_PIPE_END_READ),
				    &maint_child_death, NULL);

  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, "ARM", "GLOBAL_PREFIX",
					     &prefix_command))
    prefix_command = GNUNET_strdup ("");
  if (GNUNET_OK !=
      GNUNET_CONFIGURATION_get_value_string (cfg, "ARM", "GLOBAL_POSTFIX",
					     &final_option))
    final_option = GNUNET_strdup ("");
  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno (cfg, "ARM", "USER_ONLY"))
  {
    GNUNET_break (GNUNET_YES == start_user);
    start_system = GNUNET_NO;
  }
  if (GNUNET_YES ==
      GNUNET_CONFIGURATION_get_value_yesno (cfg, "ARM", "SYSTEM_ONLY"))
  {
    GNUNET_break (GNUNET_YES == start_system);
    start_user = GNUNET_NO;
  }
  GNUNET_CONFIGURATION_iterate_sections (cfg, &setup_service, NULL);

  /* start default services... */
  if (GNUNET_OK ==
      GNUNET_CONFIGURATION_get_value_string (cfg,
                                             "ARM",
                                             "DEFAULTSERVICES",
					     &defaultservices))
  {
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _("Starting default services `%s'\n"),
                defaultservices);
    if (0 < strlen (defaultservices))
    {
      for (pos = strtok (defaultservices, " "); NULL != pos;
           pos = strtok (NULL, " "))
      {
        sl = find_service (pos);
        if (NULL == sl)
        {
          GNUNET_log (GNUNET_ERROR_TYPE_ERROR,
                      _("Default service `%s' not configured correctly!\n"),
                      pos);
          continue;
        }
        sl->is_default = GNUNET_YES;
        start_process (sl, NULL, 0);
      }
    }
    GNUNET_free (defaultservices);
  }
  else
  {
    GNUNET_log (GNUNET_ERROR_TYPE_INFO,
                _("No default services configured, GNUnet will not really start right now.\n"));
  }

  notifier =
      GNUNET_SERVER_notification_context_create (server, MAX_NOTIFY_QUEUE);
  GNUNET_SERVER_connect_notify (server, handle_client_connecting, NULL);
  /* process client requests */
  GNUNET_SERVER_add_handlers (server, handlers);
}


/**
 * The main function for the arm service.
 *
 * @param argc number of arguments from the command line
 * @param argv command line arguments
 * @return 0 ok, 1 on error
 */
int
main (int argc, char *const *argv)
{
  int ret;
  struct GNUNET_SIGNAL_Context *shc_chld;

  sigpipe = GNUNET_DISK_pipe (GNUNET_NO, GNUNET_NO, GNUNET_NO, GNUNET_NO);
  GNUNET_assert (sigpipe != NULL);
  shc_chld =
    GNUNET_SIGNAL_handler_install (GNUNET_SIGCHLD, &sighandler_child_death);
  ret =
    (GNUNET_OK ==
     GNUNET_SERVICE_run (argc, argv, "arm",
			 GNUNET_SERVICE_OPTION_MANUAL_SHUTDOWN, &run, NULL)) ? 0 : 1;
  GNUNET_SIGNAL_handler_uninstall (shc_chld);
  shc_chld = NULL;
  GNUNET_DISK_pipe_close (sigpipe);
  sigpipe = NULL;
  return ret;
}


#ifdef LINUX
#include <malloc.h>

/**
 * MINIMIZE heap size (way below 128k) since this process doesn't need much.
 */
void __attribute__ ((constructor)) GNUNET_ARM_memory_init ()
{
  mallopt (M_TRIM_THRESHOLD, 4 * 1024);
  mallopt (M_TOP_PAD, 1 * 1024);
  malloc_trim (0);
}
#endif


/* end of gnunet-service-arm.c */