aboutsummaryrefslogtreecommitdiff
path: root/src/or/or.h
blob: 6356549467ac397276f05ae6be9fcd8e0c4f66f4 (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
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
2095
2096
2097
2098
2099
2100
2101
2102
2103
2104
2105
2106
2107
2108
2109
2110
2111
2112
2113
2114
2115
2116
2117
2118
2119
2120
2121
2122
2123
2124
2125
2126
2127
2128
2129
2130
2131
2132
2133
2134
2135
2136
2137
2138
2139
2140
2141
2142
2143
2144
2145
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156
2157
2158
2159
2160
2161
2162
2163
2164
2165
2166
2167
2168
2169
2170
2171
2172
2173
2174
2175
2176
2177
2178
2179
2180
2181
2182
2183
2184
2185
2186
2187
2188
2189
2190
2191
2192
2193
2194
2195
2196
2197
2198
2199
2200
2201
2202
2203
2204
2205
2206
2207
2208
2209
2210
2211
2212
2213
2214
2215
2216
2217
2218
2219
2220
2221
2222
2223
2224
2225
2226
2227
2228
2229
2230
2231
2232
2233
2234
2235
2236
2237
2238
2239
2240
2241
2242
/* Copyright 2001 Matej Pfajfar.
 * Copyright 2001-2004 Roger Dingledine.
 * Copyright 2004-2005 Roger Dingledine, Nick Mathewson. */
/* See LICENSE for licensing information */
/* $Id$ */

/**
 * \file or.h
 * \brief Master header file for Tor-specific functionality.
 **/

#ifndef __OR_H
#define __OR_H
#define OR_H_ID "$Id$"

#include "orconfig.h"
#ifdef MS_WINDOWS
#define WIN32_WINNT 0x400
#define _WIN32_WINNT 0x400
#define WIN32_LEAN_AND_MEAN
#endif

#include <stdio.h>
#include <stdlib.h>
#include <limits.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_CTYPE_H
#include <ctype.h>
#endif
#include "../common/torint.h"
#ifdef HAVE_INTTYPES_H
#include <inttypes.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h> /* FreeBSD needs this to know what version it is */
#endif
#ifdef HAVE_SYS_LIMITS_H
#include <sys/limits.h>
#endif
#ifdef HAVE_MACHINE_LIMITS_H
#ifndef __FreeBSD__
  /* FreeBSD has a bug where it complains that this file is obsolete,
     and I should migrate to using sys/limits. It complains even when
     I include both. */
#include <machine/limits.h>
#endif
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h> /* Must be included before sys/stat.h for Ultrix */
#endif
#ifdef HAVE_SYS_WAIT_H
#include <sys/wait.h>
#endif
#ifdef HAVE_SYS_FCNTL_H
#include <sys/fcntl.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_ASSERT_H
#include <assert.h>
#endif
#ifdef HAVE_TIME_H
#include <time.h>
#endif

/** Upper bound on maximum simultaneous connections; can be lowered by
 * config file. */
#define MAXCONNECTIONS 15000

#ifdef MS_WINDOWS
/* No, we don't need to redefine FD_SETSIZE before including winsock:
 * we use libevent now, and libevent handles the select() stuff.  Yes,
 * some documents imply that we need to redefine anyway if we're using
 * select() anywhere in our application or in anything it links to: these
 * documents are either the holy texts of a cargo cult of network
 * programmers, or more likely a simplification of what's going on for
 * people who haven't read winsock[2].c for themselves.
 */
#if (_MSC_VER <= 1300)
#include <winsock.h>
#else
#include <winsock2.h>
#include <ws2tcpip.h>
#endif
#endif

#ifdef MS_WINDOWS
#include <io.h>
#include <process.h>
#include <direct.h>
#include <windows.h>
#define snprintf _snprintf
#endif

#ifdef HAVE_EVENT_H
#include <event.h>
#else
#error "Tor requires libevent to build."
#endif

#include "../common/crypto.h"
#include "../common/tortls.h"
#include "../common/log.h"
#include "../common/compat.h"
#include "../common/container.h"
#include "../common/util.h"
#include "../common/torgzip.h"

/* These signals are defined to help control_signal_act work.
 * XXXX Move into compat.h ?
 */
#ifndef SIGHUP
#define SIGHUP 1
#endif
#ifndef SIGINT
#define SIGINT 2
#endif
#ifndef SIGUSR1
#define SIGUSR1 10
#endif
#ifndef SIGUSR2
#define SIGUSR2 12
#endif
#ifndef SIGTERM
#define SIGTERM 15
#endif

#if (SIZEOF_CELL_T != 0)
/* On Irix, stdlib.h defines a cell_t type, so we need to make sure
 * that our stuff always calls cell_t something different. */
#define cell_t tor_cell_t
#endif

#define DEFAULT_BANDWIDTH_OP (1024 * 1000)
#define MAX_NICKNAME_LEN 19
/* Hex digest plus dollar sign. */
#define MAX_HEX_NICKNAME_LEN (HEX_DIGEST_LEN+1)
/** Maximum size, in bytes, for resized buffers. */
#define MAX_BUF_SIZE ((1<<24)-1)
#define MAX_DIR_SIZE MAX_BUF_SIZE

/* For http parsing */
#define MAX_HEADERS_SIZE 50000
#define MAX_BODY_SIZE 500000

#ifdef TOR_PERF
/** How long do we keep DNS cache entries before purging them? */
#define MAX_DNS_ENTRY_AGE (150*60)
#else
#define MAX_DNS_ENTRY_AGE (30*60)
#endif

/** How often do we rotate onion keys? */
#define MIN_ONION_KEY_LIFETIME (7*24*60*60) /* once a week */
/** How often do we rotate TLS contexts? */
#define MAX_SSL_KEY_LIFETIME (120*60)

/** How old do we allow a router to get before removing it, either
 * from the descriptor list (for dirservers) or the router list (for others)?
 * In seconds. */
#define ROUTER_MAX_AGE (60*60*24)

typedef enum {
  CIRC_ID_TYPE_LOWER=0,
  CIRC_ID_TYPE_HIGHER=1
} circ_id_type_t;

#define _CONN_TYPE_MIN 3
/** Type for sockets listening for OR connections. */
#define CONN_TYPE_OR_LISTENER 3
/** A bidirectional TLS connection transmitting a sequence of cells.
 * May be from an OR to an OR, or from an OP to an OR. */
#define CONN_TYPE_OR 4
/** A TCP connection from an onion router to a stream's destination. */
#define CONN_TYPE_EXIT 5
/** Type for sockets listening for SOCKS connections. */
#define CONN_TYPE_AP_LISTENER 6
/** A SOCKS proxy connection from the user application to the onion
 * proxy. */
#define CONN_TYPE_AP 7
/** Type for sockets listening for HTTP connections to the directory server. */
#define CONN_TYPE_DIR_LISTENER 8
/** Type for HTTP connections to the directory server. */
#define CONN_TYPE_DIR 9
/** Connection from the main process to a DNS worker process. */
#define CONN_TYPE_DNSWORKER 10
/** Connection from the main process to a CPU worker process. */
#define CONN_TYPE_CPUWORKER 11
/** Type for listenting for connections from user interface process */
#define CONN_TYPE_CONTROL_LISTENER 12
/** Type for connections from user interface process */
#define CONN_TYPE_CONTROL 13
#define _CONN_TYPE_MAX 13

#define CONN_IS_EDGE(x) ((x)->type == CONN_TYPE_EXIT || (x)->type == CONN_TYPE_AP)

/** State for any listener connection. */
#define LISTENER_STATE_READY 0

#define _DNSWORKER_STATE_MIN 1
/** State for a connection to a dnsworker process that's idle. */
#define DNSWORKER_STATE_IDLE 1
/** State for a connection to a dnsworker process that's resolving a hostname. */
#define DNSWORKER_STATE_BUSY 2
#define _DNSWORKER_STATE_MAX 2

#define _CPUWORKER_STATE_MIN 1
/** State for a connection to a cpuworker process that's idle. */
#define CPUWORKER_STATE_IDLE 1
/** State for a connection to a cpuworker process that's processing a
 * handshake. */
#define CPUWORKER_STATE_BUSY_ONION 2
#define _CPUWORKER_STATE_MAX 2

#define CPUWORKER_TASK_ONION CPUWORKER_STATE_BUSY_ONION

#define _OR_CONN_STATE_MIN 1
/** State for a connection to an OR: waiting for connect() to finish. */
#define OR_CONN_STATE_CONNECTING 1
/** State for a connection to an OR: waiting for proxy command to flush. */
#define OR_CONN_STATE_PROXY_FLUSHING 2
/** State for a connection to an OR: waiting for proxy response. */
#define OR_CONN_STATE_PROXY_READING 3
/** State for a connection to an OR: SSL is handshaking, not done yet. */
#define OR_CONN_STATE_HANDSHAKING 4
/** State for a connection to an OR: Ready to send/receive cells. */
#define OR_CONN_STATE_OPEN 5
#define _OR_CONN_STATE_MAX 5

#define _EXIT_CONN_STATE_MIN 1
/** State for an exit connection: waiting for response from dns farm. */
#define EXIT_CONN_STATE_RESOLVING 1
/** State for an exit connection: waiting for connect() to finish. */
#define EXIT_CONN_STATE_CONNECTING 2
/** State for an exit connection: open and ready to transmit data. */
#define EXIT_CONN_STATE_OPEN 3
/** State for an exit connection: waiting to be removed. */
#define EXIT_CONN_STATE_RESOLVEFAILED 4
#define _EXIT_CONN_STATE_MAX 4

/* the AP state values must be disjoint from the EXIT state values */
#define _AP_CONN_STATE_MIN 5
/** State for a SOCKS connection: waiting for SOCKS request. */
#define AP_CONN_STATE_SOCKS_WAIT 5
/** State for a SOCKS connection: got a y.onion URL; waiting to receive
 * rendezvous rescriptor. */
#define AP_CONN_STATE_RENDDESC_WAIT 6
/** The controller will attach this connection to a circuit; it isn't our
 * job to do so. */
#define AP_CONN_STATE_CONTROLLER_WAIT 7
/** State for a SOCKS connection: waiting for a completed circuit. */
#define AP_CONN_STATE_CIRCUIT_WAIT 8
/** State for a SOCKS connection: sent BEGIN, waiting for CONNECTED. */
#define AP_CONN_STATE_CONNECT_WAIT 9
/** State for a SOCKS connection: send RESOLVE, waiting for RESOLVED. */
#define AP_CONN_STATE_RESOLVE_WAIT 10
/** State for a SOCKS connection: ready to send and receive. */
#define AP_CONN_STATE_OPEN 11
#define _AP_CONN_STATE_MAX 11

#define _DIR_CONN_STATE_MIN 1
/** State for connection to directory server: waiting for connect(). */
#define DIR_CONN_STATE_CONNECTING 1
/** State for connection to directory server: sending HTTP request. */
#define DIR_CONN_STATE_CLIENT_SENDING 2
/** State for connection to directory server: reading HTTP response. */
#define DIR_CONN_STATE_CLIENT_READING 3
/** State for connection to directory server: happy and finished. */
#define DIR_CONN_STATE_CLIENT_FINISHED 4
/** State for connection at directory server: waiting for HTTP request. */
#define DIR_CONN_STATE_SERVER_COMMAND_WAIT 5
/** State for connection at directory server: sending HTTP response. */
#define DIR_CONN_STATE_SERVER_WRITING 6
#define _DIR_CONN_STATE_MAX 6

#define _CONTROL_CONN_STATE_MIN 1
#define CONTROL_CONN_STATE_OPEN_V0 1
#define CONTROL_CONN_STATE_OPEN_V1 2
#define CONTROL_CONN_STATE_NEEDAUTH_V0 3
#define CONTROL_CONN_STATE_NEEDAUTH_V1 4
#define _CONTROL_CONN_STATE_MAX 4

#define _DIR_PURPOSE_MIN 1
/** Purpose for connection to directory server: download a directory. */
#define DIR_PURPOSE_FETCH_DIR 1
/** Purpose for connection to directory server: download just the list
 * of running routers. */
#define DIR_PURPOSE_FETCH_RUNNING_LIST 2
/** Purpose for connection to directory server: download a rendezvous
 * descriptor. */
#define DIR_PURPOSE_FETCH_RENDDESC 3
/** Purpose for connection to directory server: set after a rendezvous
 * descriptor is downloaded. */
#define DIR_PURPOSE_HAS_FETCHED_RENDDESC 4
/** A connection to a directory server: download one or more network-status
 * objects */
#define DIR_PURPOSE_FETCH_NETWORKSTATUS 5
/**  A connection to a directory server: download one or more server
 * descriptors. */
#define DIR_PURPOSE_FETCH_SERVERDESC 6
/** Purpose for connection to directory server: upload a server descriptor. */
#define DIR_PURPOSE_UPLOAD_DIR 7
/** Purpose for connection to directory server: upload a rendezvous
 * descriptor. */
#define DIR_PURPOSE_UPLOAD_RENDDESC 8
/** Purpose for connection at a directory server. */
#define DIR_PURPOSE_SERVER 9
#define _DIR_PURPOSE_MAX 9

#define _EXIT_PURPOSE_MIN 1
#define EXIT_PURPOSE_CONNECT 1
#define EXIT_PURPOSE_RESOLVE 2
#define _EXIT_PURPOSE_MAX 2

/** Circuit state: I'm the OP, still haven't done all my handshakes. */
#define CIRCUIT_STATE_BUILDING 0
/** Circuit state: Waiting to process the onionskin. */
#define CIRCUIT_STATE_ONIONSKIN_PENDING 1
/** Circuit state: I'd like to deliver a create, but my n_conn is still connecting. */
#define CIRCUIT_STATE_OR_WAIT 2
/** Circuit state: onionskin(s) processed, ready to send/receive cells. */
#define CIRCUIT_STATE_OPEN 3

#define _CIRCUIT_PURPOSE_MIN 1

/* these circuits were initiated elsewhere */
#define _CIRCUIT_PURPOSE_OR_MIN 1
/** OR-side circuit purpose: normal circuit, at OR. */
#define CIRCUIT_PURPOSE_OR 1
/** OR-side circuit purpose: At OR, from Bob, waiting for intro from Alices. */
#define CIRCUIT_PURPOSE_INTRO_POINT 2
/** OR-side circuit purpose: At OR, from Alice, waiting for Bob. */
#define CIRCUIT_PURPOSE_REND_POINT_WAITING 3
/** OR-side circuit purpose: At OR, both circuits have this purpose. */
#define CIRCUIT_PURPOSE_REND_ESTABLISHED 4
#define _CIRCUIT_PURPOSE_OR_MAX 4

/* these circuits originate at this node */

/* here's how circ client-side purposes work:
 *   normal circuits are C_GENERAL.
 *   circuits that are c_introducing are either on their way to
 *     becoming open, or they are open and waiting for a
 *     suitable rendcirc before they send the intro.
 *   circuits that are c_introduce_ack_wait have sent the intro,
 *     but haven't gotten a response yet.
 *   circuits that are c_establish_rend are either on their way
 *     to becoming open, or they are open and have sent the
 *     establish_rendezvous cell but haven't received an ack.
 *   circuits that are c_rend_ready are open and have received a
 *     rend ack, but haven't heard from bob yet. if they have a
 *     buildstate->pending_final_cpath then they're expecting a
 *     cell from bob, else they're not.
 *   circuits that are c_rend_ready_intro_acked are open, and
 *     some intro circ has sent its intro and received an ack.
 *   circuits that are c_rend_joined are open, have heard from
 *     bob, and are talking to him.
 */
/** Client-side circuit purpose: Normal circuit, with cpath. */
#define CIRCUIT_PURPOSE_C_GENERAL 5
/** Client-side circuit purpose: at Alice, connecting to intro point. */
#define CIRCUIT_PURPOSE_C_INTRODUCING 6
/** Client-side circuit purpose: at Alice, sent INTRODUCE1 to intro point, waiting for ACK/NAK. */
#define CIRCUIT_PURPOSE_C_INTRODUCE_ACK_WAIT 7
/** Client-side circuit purpose: at Alice, introduced and acked, closing. */
#define CIRCUIT_PURPOSE_C_INTRODUCE_ACKED 8
/** Client-side circuit purpose: at Alice, waiting for ack. */
#define CIRCUIT_PURPOSE_C_ESTABLISH_REND 9
/** Client-side circuit purpose: at Alice, waiting for Bob. */
#define CIRCUIT_PURPOSE_C_REND_READY 10
/** Client-side circuit purpose: at Alice, waiting for Bob, INTRODUCE
 * has been acknowledged. */
#define CIRCUIT_PURPOSE_C_REND_READY_INTRO_ACKED 11
/** Client-side circuit purpose: at Alice, rendezvous established. */
#define CIRCUIT_PURPOSE_C_REND_JOINED 12

/** Hidden-service-side circuit purpose: at Bob, waiting for introductions. */
#define CIRCUIT_PURPOSE_S_ESTABLISH_INTRO 13
/** Hidden-service-side circuit purpose: at Bob, successfully established
 * intro. */
#define CIRCUIT_PURPOSE_S_INTRO 14
/** Hidden-service-side circuit purpose: at Bob, connecting to rend point. */
#define CIRCUIT_PURPOSE_S_CONNECT_REND 15
/** Hidden-service-side circuit purpose: at Bob, rendezvous established. */
#define CIRCUIT_PURPOSE_S_REND_JOINED 16
/** A testing circuit; not meant to be used for actual traffic. */
#define CIRCUIT_PURPOSE_TESTING 17
#define _CIRCUIT_PURPOSE_MAX 17

/** True iff the circuit purpose <b>p</b> is for a circuit at the OP
 * that this OP has originated. */
#define CIRCUIT_PURPOSE_IS_ORIGIN(p) ((p)>_CIRCUIT_PURPOSE_OR_MAX)
#define CIRCUIT_IS_ORIGIN(c) (CIRCUIT_PURPOSE_IS_ORIGIN((c)->purpose))

#define RELAY_COMMAND_BEGIN 1
#define RELAY_COMMAND_DATA 2
#define RELAY_COMMAND_END 3
#define RELAY_COMMAND_CONNECTED 4
#define RELAY_COMMAND_SENDME 5
#define RELAY_COMMAND_EXTEND 6
#define RELAY_COMMAND_EXTENDED 7
#define RELAY_COMMAND_TRUNCATE 8
#define RELAY_COMMAND_TRUNCATED 9
#define RELAY_COMMAND_DROP 10
#define RELAY_COMMAND_RESOLVE 11
#define RELAY_COMMAND_RESOLVED 12

#define RELAY_COMMAND_ESTABLISH_INTRO 32
#define RELAY_COMMAND_ESTABLISH_RENDEZVOUS 33
#define RELAY_COMMAND_INTRODUCE1 34
#define RELAY_COMMAND_INTRODUCE2 35
#define RELAY_COMMAND_RENDEZVOUS1 36
#define RELAY_COMMAND_RENDEZVOUS2 37
#define RELAY_COMMAND_INTRO_ESTABLISHED 38
#define RELAY_COMMAND_RENDEZVOUS_ESTABLISHED 39
#define RELAY_COMMAND_INTRODUCE_ACK 40

#define END_STREAM_REASON_MISC 1
#define END_STREAM_REASON_RESOLVEFAILED 2
#define END_STREAM_REASON_CONNECTREFUSED 3
#define END_STREAM_REASON_EXITPOLICY 4
#define END_STREAM_REASON_DESTROY 5
#define END_STREAM_REASON_DONE 6
#define END_STREAM_REASON_TIMEOUT 7
/* 8 is unallocated. */
#define END_STREAM_REASON_HIBERNATING 9
#define END_STREAM_REASON_INTERNAL 10
#define END_STREAM_REASON_RESOURCELIMIT 11
#define END_STREAM_REASON_CONNRESET 12
#define END_STREAM_REASON_TORPROTOCOL 13

/* These high-numbered end reasons are not part of the official spec,
 * and are not intended to be put in relay end cells. They are here
 * to be more informative when sending back socks replies to the
 * application. */
#define END_STREAM_REASON_ALREADY_SOCKS_REPLIED 256
#define END_STREAM_REASON_CANT_ATTACH 257
#define END_STREAM_REASON_NET_UNREACHABLE 258

#define RESOLVED_TYPE_HOSTNAME 0
#define RESOLVED_TYPE_IPV4 4
#define RESOLVED_TYPE_IPV6 6
#define RESOLVED_TYPE_ERROR_TRANSIENT 0xF0
#define RESOLVED_TYPE_ERROR 0xF1

/** Length of 'y' portion of 'y.onion' URL. */
#define REND_SERVICE_ID_LEN 16

#define CELL_DIRECTION_IN 1
#define CELL_DIRECTION_OUT 2

#ifdef TOR_PERF
#define CIRCWINDOW_START 10000
#define CIRCWINDOW_INCREMENT 1000
#define STREAMWINDOW_START 5000
#define STREAMWINDOW_INCREMENT 500
#else
#define CIRCWINDOW_START 1000
#define CIRCWINDOW_INCREMENT 100
#define STREAMWINDOW_START 500
#define STREAMWINDOW_INCREMENT 50
#endif

/* cell commands */
#define CELL_PADDING 0
#define CELL_CREATE 1
#define CELL_CREATED 2
#define CELL_RELAY 3
#define CELL_DESTROY 4
#define CELL_CREATE_FAST 5
#define CELL_CREATED_FAST 6

/* people behind fascist firewalls use only these ports */
#define REQUIRED_FIREWALL_DIRPORT 80
#define REQUIRED_FIREWALL_ORPORT 443

/* legal characters in a nickname */
#define LEGAL_NICKNAME_CHARACTERS "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

/** Name to use in client TLS certificates if no nickname is given.*/
#define DEFAULT_CLIENT_NICKNAME "client"

#define SOCKS4_NETWORK_LEN 8

typedef enum {
  SOCKS5_SUCCEEDED                  = 0x00,
  SOCKS5_GENERAL_ERROR              = 0x01,
  SOCKS5_NOT_ALLOWED                = 0x02,
  SOCKS5_NET_UNREACHABLE            = 0x03,
  SOCKS5_HOST_UNREACHABLE           = 0x04,
  SOCKS5_CONNECTION_REFUSED         = 0x05,
  SOCKS5_TTL_EXPIRED                = 0x06,
  SOCKS5_COMMAND_NOT_SUPPORTED      = 0x07,
  SOCKS5_ADDRESS_TYPE_NOT_SUPPORTED = 0x08,
} socks5_reply_status_t;

/*
 * Relay payload:
 *         Relay command           [1 byte]
 *         Recognized              [2 bytes]
 *         Stream ID               [2 bytes]
 *         Partial SHA-1           [4 bytes]
 *         Length                  [2 bytes]
 *         Relay payload           [498 bytes]
 */

#define CELL_PAYLOAD_SIZE 509
#define CELL_NETWORK_SIZE 512

#define RELAY_HEADER_SIZE (1+2+2+4+2)
#define RELAY_PAYLOAD_SIZE (CELL_PAYLOAD_SIZE-RELAY_HEADER_SIZE)

/** Parsed onion routing cell.  All communication from OP-to-OR, or from
 * OR-to-OR, is via cells. */
typedef struct {
  uint16_t circ_id; /**< Circuit which received the cell. */
  uint8_t command; /**< Type of the cell: one of PADDING, CREATE, RELAY,
                    * or DESTROY. */
  char payload[CELL_PAYLOAD_SIZE]; /**< Cell body. */
} cell_t;

/** Beginning of a RELAY cell payload. */
typedef struct {
  uint8_t command; /**< The end-to-end relay command. */
  uint16_t recognized; /**< Used to tell whether cell is for us. */
  uint16_t stream_id; /**< Which stream is this cell associated with? */
  char integrity[4]; /**< Used to tell whether cell is corrupted. */
  uint16_t length; /**< How long is the payload body? */
} relay_header_t;

typedef struct buf_t buf_t;
typedef struct socks_request_t socks_request_t;

#define CONNECTION_MAGIC 0x7C3C304Eu

/** Description of a connection to another host or process, and associated
 * data.
 *
 * A connection is named based on what it's connected to -- an "OR
 * connection" has an onion router on the other end, an "OP connection"
 * (nearly obsolete) has an onion proxy on the other end, an "exit
 * connection" has a website or other server on the other end, and an
 * "AP connection" has an application proxy (and thus a user) on the
 * other end.
 *
 * Every connection has a type and a state.  Connections never change
 * their type, but can go through many state changes in their lifetime.
 *
 * Every connection has two associated input and output buffers.
 * Listeners don't use them.  For non-listener connections, incoming
 * data is appended to conn->inbuf, and outgoing data is taken from
 * conn->outbuf.  Connections differ primarily in the functions called
 * to fill and drain these buffers.
 */
struct connection_t {
  uint32_t magic; /**< For memory debugging: must equal CONNECTION_MAGIC. */

  uint8_t type; /**< What kind of connection is this? */
  uint8_t state; /**< Current state of this connection. */
  uint8_t purpose; /**< Only used for DIR types currently. */
  unsigned wants_to_read:1; /**< Boolean: should we start reading again once
                            * the bandwidth throttler allows it?
                            */
  unsigned wants_to_write:1; /**< Boolean: should we start writing again once
                             * the bandwidth throttler allows reads?
                             */
  unsigned hold_open_until_flushed:1; /**< Despite this connection's being
                                      * marked for close, do we flush it
                                      * before closing it?
                                      */
  unsigned has_sent_end:1; /**< For debugging; only used on edge connections.
                         * Set once we've set the stream end,
                         * and check in circuit_about_to_close_connection(). */
  /** For control connections only. If set, we send extended info with control
   * events as appropriate. */
  unsigned int control_events_are_extended:1;

  int s; /**< Our socket; -1 if this connection is closed. */
  int poll_index; /* XXXX rename. */
  struct event *read_event; /**< libevent event structure. */
  struct event *write_event; /**< libevent event structure. */
  int marked_for_close; /**< Should we close this conn on the next iteration
                         * of the main loop? (If true, holds the line number
                         * where this connection was marked.)
                         */
  const char *marked_for_close_file; /**< For debugging: in which file were
                                      * we marked for close? */

  buf_t *inbuf; /**< Buffer holding data read over this connection. */
  int inbuf_reached_eof; /**< Boolean: did read() return 0 on this conn? */
  time_t timestamp_lastread; /**< When was the last time poll() said we could read? */

  buf_t *outbuf; /**< Buffer holding data to write over this connection. */
  size_t outbuf_flushlen; /**< How much data should we try to flush from the
                           * outbuf? */
  time_t timestamp_lastwritten; /**< When was the last time poll() said we could write? */

  time_t timestamp_created; /**< When was this connection_t created? */
  time_t timestamp_lastempty; /**< When was the outbuf last completely empty?*/

  uint32_t addr; /**< IP of the other side of the connection; used to identify
                  * routers, along with port. */
  uint16_t port; /**< If non-zero, port  on the other end
                  * of the connection. */
  char *address; /**< FQDN (or IP) of the guy on the other end.
                  * strdup into this, because free_connection frees it.
                  */
  crypto_pk_env_t *identity_pkey; /**< Public RSA key for the other side's
                                   * signing key. */
  char identity_digest[DIGEST_LEN]; /**< Hash of identity_pkey */
  char *nickname; /**< Nickname of OR on other side (if any). */

  /** Nickname of planned exit node -- used with .exit support. */
  char *chosen_exit_name;

/* Used only by OR connections: */
  tor_tls_t *tls; /**< TLS connection state (OR only.) */
  uint16_t next_circ_id; /**< Which circ_id do we try to use next on
                          * this connection?  This is always in the
                          * range 0..1<<15-1. (OR only.)*/

  /* bandwidth and receiver_bucket only used by ORs in OPEN state: */
  int bandwidth; /**< Connection bandwidth. (OPEN ORs only.) */
  int receiver_bucket; /**< When this hits 0, stop receiving. Every second we
                        * add 'bandwidth' to this, capping it at 10*bandwidth.
                        * (OPEN ORs only)
                        */
  circ_id_type_t circ_id_type; /**< When we send CREATE cells along this
                                * connection, which half of the space should
                                * we use? */

/* Used only by DIR and AP connections: */
  char rend_query[REND_SERVICE_ID_LEN+1]; /**< What rendezvous service are we
                                           * querying for? (DIR/AP only) */

/* Used only by edge connections: */
  uint16_t stream_id;
  struct connection_t *next_stream; /**< Points to the next stream at this
                                     * edge, if any (Edge only). */
  struct crypt_path_t *cpath_layer; /**< A pointer to which node in the circ
                                     * this conn exits at. (Edge only.) */
  int package_window; /**< How many more relay cells can i send into the
                       * circuit? (Edge only.) */
  int deliver_window; /**< How many more relay cells can end at me? (Edge
                       * only.) */

#if 0
  int done_sending; /**< For half-open connections; not used currently. */
  int done_receiving; /**< For half-open connections; not used currently. */
#endif
  struct circuit_t *on_circuit; /**< The circuit (if any) that this edge
                                 * connection is using. */

/* Used only by Dir connections */
  char *requested_resource; /**< Which 'resource' did we ask the directory for?*/

/* Used only by AP connections */
  socks_request_t *socks_request; /**< SOCKS structure describing request (AP
                                   * only.) */

  /** Quasi-global identifier for this connection; used for control.c */
  /* XXXX NM This can get re-used after 2**32 circuits. */
  uint32_t global_identifier;

  /* Used only by control connections */
  uint32_t event_mask;
  uint32_t incoming_cmd_len;
  uint32_t incoming_cmd_cur_len;
  char *incoming_cmd;

  /* Used only by control v0 connections */
  uint16_t incoming_cmd_type;
};

typedef struct connection_t connection_t;

typedef enum {
  ADDR_POLICY_ACCEPT=1,
  ADDR_POLICY_REJECT=2,
} addr_policy_action_t;

/** A linked list of policy rules */
typedef struct addr_policy_t {
  addr_policy_action_t policy_type; /**< What to do when the policy matches.*/
  char *string; /**< String representation of this rule. */
  uint32_t addr; /**< Base address to accept or reject. */
  uint32_t msk; /**< Accept/reject all addresses <b>a</b> such that
                 * a &amp; msk == <b>addr</b> &amp; msk . */
  uint16_t prt_min; /**< Lowest port number to accept/reject. */
  uint16_t prt_max; /**< Highest port number to accept/reject. */

  struct addr_policy_t *next; /**< Next rule in list. */
} addr_policy_t;

/** A cached_dir_t represents a cacheable directory object, along with its
 * compressed form. */
typedef struct cached_dir_t {
  char *dir; /**< Contents of this object */
  char *dir_z; /**< Compressed contents of this object. */
  size_t dir_len; /**< Length of <b>dir</b> */
  size_t dir_z_len; /**< Length of <b>dir_z</b> */
  time_t published; /**< When was this object published */
} cached_dir_t;

/** Information about another onion router in the network. */
typedef struct {
  char *signed_descriptor; /**< The original signed descriptor for this router*/
  size_t signed_descriptor_len; /**< The length of signed_descriptor */
  char signed_descriptor_digest[DIGEST_LEN]; /**< The digest of the signed descriptor. */

  char *address; /**< Location of OR: either a hostname or an IP address. */
  char *nickname; /**< Human-readable OR name. */

  uint32_t addr; /**< IPv4 address of OR, in host order. */
  uint16_t or_port; /**< Port for OR-to-OR and OP-to-OR connections. */
  uint16_t dir_port; /**< Port for HTTP directory connections. */

  time_t published_on; /**< When was the information in this routerinfo_t
                        * published? */

  crypto_pk_env_t *onion_pkey; /**< Public RSA key for onions. */
  crypto_pk_env_t *identity_pkey;  /**< Public RSA key for signing. */
  char identity_digest[DIGEST_LEN]; /**< Digest of identity key */

  char *platform; /**< What software/operating system is this OR using? */

  /* link info */
  uint32_t bandwidthrate; /**< How many bytes does this OR add to its token
                           * bucket per second? */
  uint32_t bandwidthburst; /**< How large is this OR's token bucket? */
  /** How many bytes/s is this router known to handle? */
  uint32_t bandwidthcapacity;
  addr_policy_t *exit_policy; /**< What streams will this OR permit
                                      * to exit? */
  long uptime; /**< How many seconds the router claims to have been up */
  smartlist_t *declared_family; /**< Nicknames of router which this router
                                 * claims are its family. */
  char *contact_info; /**< Declared contact info for this router. */
  unsigned int is_hibernating:1; /**< Whether the router claims to be
                                  * hibernating */

  /* local info */
  unsigned int is_running:1; /**< As far as we know, is this OR currently
                              * running? */
  unsigned int is_verified:1; /**< Has a trusted dirserver validated this OR?
                               *  (For Authdir: Have we validated this OR?)
                               */
  unsigned int is_named:1; /**< Do we believe the nickname that this OR gives
                            * us? */
  unsigned int xx_is_recognized:1; /**< Temporary: do we think that this
                                    * descriptor's digest is recognized?
                                    */
  unsigned int xx_is_extra_new:1; /**< Temporary: do we think that this
                                   * descriptor's digest is recognized?
                                   */

  /* The below items are used only by authdirservers for
   * reachability testing. */
  /** When was the last time we could reach this OR? */
  time_t last_reachable;
  /** When did we start testing reachability for this OR? */
  time_t testing_since;
  /** How many times has a descriptor been posted and we believed
   * this router to be unreachable? We only actually warn on the third. */
  int num_unreachable_notifications;
} routerinfo_t;

/** Contents of a single router entry in a network status object.
 */
typedef struct routerstatus_t {
  time_t published_on; /**< When was this router published? */
  char nickname[MAX_NICKNAME_LEN+1]; /**<The nickname this router says it has. */
  char identity_digest[DIGEST_LEN]; /**< Digest of the router's identity key. */
  char descriptor_digest[DIGEST_LEN]; /**< Digest of the router's most recent
                                       * descriptor. */
  uint32_t addr; /**< IPv4 address for this router. */
  uint16_t or_port; /**< OR port for this router. */
  uint16_t dir_port; /**< Directory port for this router. */
  unsigned int is_exit:1; /**< True iff this router is a good exit. */
  unsigned int is_stable:1; /**< True iff this router stays up a long time. */
  unsigned int is_fast:1; /**< True iff this router has good bandwidth. */
  unsigned int is_running:1; /**< True iff this router is up. */
  unsigned int is_named:1; /**< True iff "nickname" belongs to this router. */
  unsigned int is_valid:1; /**< True iff this router is validated. */
} routerstatus_t;

/** DOCDOC */
typedef struct local_routerstatus_t {
  routerstatus_t status;
  time_t next_attempt_at; /**< When should we try this descriptor again? */
  uint8_t n_download_failures; /**< Number of failures trying to download the
                                * most recent descriptor. */
  unsigned int should_download:1; /**< DOCDOC */
  unsigned int name_lookup_warned:1; /**< Have we warned the user for referring
                                      * to this (unnamed) router by nickname?
                                      */
} local_routerstatus_t;

/*XXXX011 make this configurable? */
#define MAX_ROUTERDESC_DOWNLOAD_FAILURES 8

/** Contents of a (v2 or later) network status object. */
typedef struct networkstatus_t {
  /** When did we receive the network-status document? */
  time_t received_on;

  /** What was the digest of the document? */
  char networkstatus_digest[DIGEST_LEN];

  unsigned int is_recent; /**< Is this recent enough to influence running
                           * status? */

  /* These fields come from the actual network-status document.*/
  time_t published_on; /**< Declared publication date. */

  char *source_address; /**< Canonical directory server hostname. */
  uint32_t source_addr; /**< Canonical directory server IP. */
  uint16_t source_dirport; /**< Canonical directory server dirport. */

  char identity_digest[DIGEST_LEN]; /**< Digest of signing key. */
  char *contact; /**< How to contact directory admin? (may be NULL). */
  crypto_pk_env_t *signing_key; /**< Key used to sign this directory. */
  char *client_versions; /**< comma-separated list of recommended client
                          * versions. */
  char *server_versions; /**< comma-separated list of recommended server
                          * versions. */

  unsigned int binds_names:1; /**< True iff this directory server binds names. */
  unsigned int recommends_versions:1; /**< True iff this directory server
                                       * recommends client and server software
                                       * versions. */

  smartlist_t *entries; /**< List of router_status_t*.   This list is kept
                         * sorted by identity_digest. */
} networkstatus_t;

/** Contents of a directory of onion routers. */
typedef struct {
  /** List of routerinfo_t. */
  smartlist_t *routers;
} routerlist_t;

/** Information on router used when extending a circuit.  (We don't need a
 * full routerinfo_t to extend: we only need addr:port:keyid to build an OR
 * connection, and onion_key to create the onionskin.) */
typedef struct extend_info_t {
  char nickname[MAX_HEX_NICKNAME_LEN+1]; /**< This router's nickname for display. */
  char identity_digest[DIGEST_LEN]; /**< Hash of this router's identity key. */
  uint32_t addr; /**< IP address in host order. */
  uint16_t port; /**< OR port. */
  crypto_pk_env_t *onion_key; /**< Current onionskin key. */
} extend_info_t;

#define CRYPT_PATH_MAGIC 0x70127012u

/** Holds accounting information for a single step in the layered encryption
 * performed by a circuit.  Used only at the client edge of a circuit. */
typedef struct crypt_path_t {
  uint32_t magic;

  /* crypto environments */
  /** Encryption key and counter for cells heading towards the OR at this
   * step. */
  crypto_cipher_env_t *f_crypto;
  /** Encryption key and counter for cells heading back from the OR at this
   * step. */
  crypto_cipher_env_t *b_crypto;

  /** Digest state for cells heading towards the OR at this step. */
  crypto_digest_env_t *f_digest; /* for integrity checking */
  /** Digest state for cells heading away from the OR at this step. */
  crypto_digest_env_t *b_digest;

  /** Current state of Diffie-Hellman key negotiation with the OR at this
   * step. */
  crypto_dh_env_t *dh_handshake_state;
  char fast_handshake_state[DIGEST_LEN];
  /** Negotiated key material shared with the OR at this step. */
  char handshake_digest[DIGEST_LEN];/* KH in tor-spec.txt */

  /** Information to extend to the OR at this step. */
  extend_info_t *extend_info;

  /** Is the circuit built to this step?  Must be one of:
   *    - CPATH_STATE_CLOSED (The circuit has not been extended to this step)
   *    - CPATH_STATE_AWAITING_KEYS (We have sent an EXTEND/CREATE to this step
   *      and not received an EXTENDED/CREATED)
   *    - CPATH_STATE_OPEN (The circuit has been extended to this step) */
  uint8_t state;
#define CPATH_STATE_CLOSED 0
#define CPATH_STATE_AWAITING_KEYS 1
#define CPATH_STATE_OPEN 2
  struct crypt_path_t *next; /**< Link to next crypt_path_t in the circuit.
                              * (The list is circular, so the last node
                              * links to the first.) */
  struct crypt_path_t *prev; /**< Link to previous crypt_path_t in the
                              * circuit. */

  int package_window; /**< How many bytes are we allowed to originate ending
                       * at this step? */
  int deliver_window; /**< How many bytes are we willing to deliver originating
                       * at this step? */
} crypt_path_t;

#define CPATH_KEY_MATERIAL_LEN (20*2+16*2)

#define DH_KEY_LEN DH_BYTES
#define ONIONSKIN_CHALLENGE_LEN (PKCS1_OAEP_PADDING_OVERHEAD+\
                                 CIPHER_KEY_LEN+\
                                 DH_KEY_LEN)
#define ONIONSKIN_REPLY_LEN (DH_KEY_LEN+DIGEST_LEN)
#define REND_COOKIE_LEN DIGEST_LEN

/** Information used to build a circuit. */
typedef struct {
  /** Intended length of the final circuit. */
  int desired_path_len;
  /** How to extend to the planned exit node. */
  extend_info_t *chosen_exit;
  /** Whether every node in the circ must have adequate uptime. */
  int need_uptime;
  /** Whether every node in the circ must have adequate capacity. */
  int need_capacity;
  /** Whether the last hop was picked with exiting in mind. */
  int is_internal;
  /** The crypt_path_t to append after rendezvous: used for rendezvous. */
  crypt_path_t *pending_final_cpath;
  /** How many times has building a circuit for this task failed? */
  int failure_count;
  /** At what time should we give up on this task? */
  time_t expiry_time;
} cpath_build_state_t;

#define CIRCUIT_MAGIC 0x35315243u

/**
 * A circuit is a path over the onion routing
 * network. Applications can connect to one end of the circuit, and can
 * create exit connections at the other end of the circuit. AP and exit
 * connections have only one circuit associated with them (and thus these
 * connection types are closed when the circuit is closed), whereas
 * OR connections multiplex many circuits at once, and stay standing even
 * when there are no circuits running over them.
 *
 * A circuit_t structure fills two roles.  First, a circuit_t links two
 * connections together: either an edge connection and an OR connection,
 * or two OR connections.  (When joined to an OR connection, a circuit_t
 * affects only cells sent to a particular circID on that connection.  When
 * joined to an edge connection, a circuit_t affects all data.)

 * Second, a circuit_t holds the cipher keys and state for sending data
 * along a given circuit.  At the OP, it has a sequence of ciphers, each
 * of which is shared with a single OR along the circuit.  Separate
 * ciphers are used for data going "forward" (away from the OP) and
 * "backward" (towards the OP).  At the OR, a circuit has only two stream
 * ciphers: one for data going forward, and one for data going backward.
 */
struct circuit_t {
  uint32_t magic; /**< For memory debugging: must equal CIRCUIT_MAGIC. */

  int marked_for_close; /**< Should we close this circuit at the end of the
                         * main loop? (If true, holds the line number where
                         * this circuit was marked.) */
  const char *marked_for_close_file; /**< For debugging: in which file was this
                                      * circuit marked for close? */

  /** The IPv4 address of the OR that is next in this circuit. */
  uint32_t n_addr;
  /** The port for the OR that is next in this circuit. */
  uint16_t n_port;
  /** The OR connection that is previous in this circuit. */
  connection_t *p_conn;
  /** The OR connection that is next in this circuit. */
  connection_t *n_conn;
  /** The identity hash of n_conn. */
  char n_conn_id_digest[DIGEST_LEN];
  /** Linked list of AP streams associated with this circuit. */
  connection_t *p_streams;
  /** Linked list of Exit streams associated with this circuit. */
  connection_t *n_streams;
  /** Linked list of Exit streams associated with this circuit that are
   * still being resolved. */
  connection_t *resolving_streams;
  /** The next stream_id that will be tried when we're attempting to
   * construct a new AP stream originating at this circuit. */
  uint16_t next_stream_id;
  /** How many relay data cells can we package (read from edge streams)
   * on this circuit before we receive a circuit-level sendme cell asking
   * for more? */
  int package_window;
  /** How many relay data cells will we deliver (write to edge streams)
   * on this circuit? When deliver_window gets low, we send some
   * circuit-level sendme cells to indicate that we're willing to accept
   * more. */
  int deliver_window;

  /** The circuit_id used in the previous (backward) hop of this circuit. */
  uint16_t p_circ_id;
  /** The circuit_id used in the next (forward) hop of this circuit. */
  uint16_t n_circ_id;

  /** The cipher used by intermediate hops for cells heading toward the
   * OP. */
  crypto_cipher_env_t *p_crypto;
  /** The cipher used by intermediate hops for cells heading away from
   * the OP. */
  crypto_cipher_env_t *n_crypto;

  /** The integrity-checking digest used by intermediate hops, for
   * cells packaged here and heading towards the OP.
   */
  crypto_digest_env_t *p_digest;
  /** The integrity-checking digest used by intermediate hops, for
   * cells packaged at the OP and arriving here.
   */
  crypto_digest_env_t *n_digest;

  /** Build state for this circuit. It includes the intended path
   * length, the chosen exit router, rendezvous information, etc.
   */
  cpath_build_state_t *build_state;
  /** The doubly-linked list of crypt_path_t entries, one per hop,
   * for this circuit. This includes ciphers for each hop,
   * integrity-checking digests for each hop, and package/delivery
   * windows for each hop.
   *
   * The cpath field is defined only when we are the circuit's origin.
   */
  crypt_path_t *cpath;

  /** For storage while passing to cpuworker, or while n_conn is pending. */
  char onionskin[ONIONSKIN_CHALLENGE_LEN];

  char handshake_digest[DIGEST_LEN]; /**< Stores KH for intermediate hops. */

  time_t timestamp_created; /**< When was this circuit created? */
  time_t timestamp_dirty; /**< When the circuit was first used, or 0 if the
                           * circuit is clean. */

  uint8_t state; /**< Current status of this circuit. */
  uint8_t purpose; /**< Why are we creating this circuit? */

  /**
   * The rend_query field holds the y portion of y.onion (nul-terminated)
   * if purpose is C_INTRODUCING or C_ESTABLISH_REND, or is a C_GENERAL
   * for a hidden service, or is S_*.
   */
  char rend_query[REND_SERVICE_ID_LEN+1];

  /** The rend_pk_digest field holds a hash of location-hidden service's
   * PK if purpose is INTRO_POINT or S_ESTABLISH_INTRO or S_RENDEZVOUSING.
   */
  char rend_pk_digest[DIGEST_LEN];

  /** Holds rendezvous cookie if purpose is REND_POINT_WAITING or
   * C_ESTABLISH_REND. Filled with zeroes otherwise.
   */
  char rend_cookie[REND_COOKIE_LEN];

  /** Points to spliced circuit if purpose is REND_ESTABLISHED, and circuit
   * is not marked for close. */
  struct circuit_t *rend_splice;

  /** Quasi-global identifier for this circuit; used for control.c */
  /* XXXX NM This can get re-used after 2**32 circuits. */
  uint32_t global_identifier;

  struct circuit_t *next; /**< Next circuit in linked list. */
};

typedef struct circuit_t circuit_t;

#define ALLOW_UNVERIFIED_ENTRY        1
#define ALLOW_UNVERIFIED_EXIT         2
#define ALLOW_UNVERIFIED_MIDDLE       4
#define ALLOW_UNVERIFIED_RENDEZVOUS   8
#define ALLOW_UNVERIFIED_INTRODUCTION 16

/** An entry specifying a set of addresses and ports that should be remapped
 * to another address and port before exiting this exit node. */
typedef struct exit_redirect_t {
  uint32_t addr;
  uint32_t mask;
  uint16_t port_min;
  uint16_t port_max;

  uint32_t addr_dest;
  uint16_t port_dest;
  unsigned is_redirect:1;
} exit_redirect_t;

/** A linked list of lines in a config file. */
typedef struct config_line_t {
  char *key;
  char *value;
  struct config_line_t *next;
} config_line_t;

/** Configuration options for a Tor process */
typedef struct {
  uint32_t _magic;

  /** What should the tor process actually do? */
  enum {
    CMD_RUN_TOR=0, CMD_LIST_FINGERPRINT, CMD_HASH_PASSWORD,
    CMD_VERIFY_CONFIG, CMD_RUN_UNITTESTS
  } command;
  const char *command_arg; /**< Argument for command-line option. */

  config_line_t *OldLogOptions; /**< List of configuration lines
                                        * for logfiles, old style. */

  config_line_t *Logs; /**< New-style list of configuration lines
                               * for logs */

  char *DebugLogFile; /**< Where to send verbose log messages. */
  char *DataDirectory; /**< OR only: where to store long-term data. */
  char *Nickname; /**< OR only: nickname of this onion router. */
  char *Address; /**< OR only: configured address for this onion router. */
  char *PidFile; /**< Where to store PID of Tor process. */

  char *ExitNodes; /**< Comma-separated list of nicknames of ORs to consider
                    * as exits. */
  char *EntryNodes; /**< Comma-separated list of nicknames of ORs to consider
                     * as entry points. */
  int StrictExitNodes; /**< Boolean: When none of our ExitNodes are up, do we
                        * stop building circuits? */
  int StrictEntryNodes; /**< Boolean: When none of our EntryNodes are up, do we
                         * stop building circuits? */
  char *ExcludeNodes; /**< Comma-separated list of nicknames of ORs not to
                       * use in circuits. */

  char *RendNodes; /**< Comma-separated list of nicknames used as introduction
                    * points. */
  char *RendExcludeNodes; /**< Comma-separated list of nicknames not to use
                           * as introduction points. */

  smartlist_t *AllowUnverifiedNodes; /**< List of "entry", "middle", "exit" */
  int _AllowUnverified; /**< Bitmask; derived from AllowUnverifiedNodes; */
  config_line_t *ExitPolicy; /**< Lists of exit policy components. */
  config_line_t *SocksPolicy; /**< Lists of socks policy components */
  config_line_t *DirPolicy; /**< Lists of dir policy components */
  /** Addresses to bind for listening for SOCKS connections. */
  config_line_t *SocksBindAddress;
  /** Addresses to bind for listening for OR connections. */
  config_line_t *ORBindAddress;
  /** Addresses to bind for listening for directory connections. */
  config_line_t *DirBindAddress;
  /** Local address to bind outbound sockets */
  char *OutboundBindAddress;
  /** Directory server only: which versions of
   * Tor should we tell users to run? */
  config_line_t *RecommendedVersions;
  config_line_t *RecommendedClientVersions;
  config_line_t *RecommendedServerVersions;
  /** Whether dirservers refuse router descriptors with private IPs. */
  int DirAllowPrivateAddresses;
  char *User; /**< Name of user to run Tor as. */
  char *Group; /**< Name of group to run Tor as. */
  double PathlenCoinWeight; /**< Parameter used to configure average path
                             * length (alpha in geometric distribution). */
  int ORPort; /**< Port to listen on for OR connections. */
  int SocksPort; /**< Port to listen on for SOCKS connections. */
  int ControlPort; /**< Port to listen on for control connections. */
  int DirPort; /**< Port to listen on for directory connections. */
  int AssumeReachable; /**< Whether to publish our descriptor regardless. */
  int AuthoritativeDir; /**< Boolean: is this an authoritative directory? */
  int V1AuthoritativeDir; /**< Boolean: is this an authoritative directory?
                           * for version 1 directories? */
  int NamingAuthoritativeDir; /**< Boolean: is this an authoritative directory
                               * that's willing to bind names? */
  int VersioningAuthoritativeDir; /**< Boolean: is this an authoritative directory
                                   * that's willing to recommend versions? */
  int ClientOnly; /**< Boolean: should we never evolve into a server role? */
  int NoPublish; /**< Boolean: should we never publish a descriptor? */
  int ConnLimit; /**< Requested maximum number of simultaneous connections. */
  int _ConnLimit; /**< Actual maximum number of simultaneous connections. */
  int IgnoreVersion; /**< If true, run no matter what versions of Tor the
                      * directory recommends. */
  int RunAsDaemon; /**< If true, run in the background. (Unix only) */
  int FascistFirewall; /**< Whether to prefer ORs reachable on open ports. */
  smartlist_t *FirewallPorts; /**< Which ports our firewall allows (strings). */
  config_line_t *ReachableAddresses; /**< Which IP:ports our firewall allows
                                      * (exit policy.) */

  /** Application ports that require all nodes in circ to have sufficient uptime. */
  smartlist_t *LongLivedPorts;
  /** Should we try to reuse the same exit node for a given host */
  smartlist_t *TrackHostExits;
  int TrackHostExitsExpire; /**< Number of seconds until we expire an addressmap */
  config_line_t *AddressMap; /**< List of address map directives. */
  int DirFetchPeriod; /**< How often do we fetch new directories? */
  int DirPostPeriod; /**< How often do we post our server descriptor to the
                      * authoritative directory servers? */
  int RendPostPeriod; /**< How often do we post each rendezvous service
                       * descriptor? Remember to publish them independently. */
  int StatusFetchPeriod; /**< How often do we fetch running-routers lists? */
  int KeepalivePeriod; /**< How often do we send padding cells to keep
                        * connections alive? */
  int MaxOnionsPending; /**< How many circuit CREATE requests do we allow
                         * to wait simultaneously before we start dropping
                         * them? */
  int NewCircuitPeriod; /**< How long do we use a circuit before building
                         * a new one? */
  int MaxCircuitDirtiness; /**< Never use circs that were first used more than
                                this interval ago. */
  uint64_t BandwidthRate; /**< How much bandwidth, on average, are we willing to
                           * use in a second? */
  uint64_t BandwidthBurst; /**< How much bandwidth, at maximum, are we willing to
                            * use in a second? */
  uint64_t MaxAdvertisedBandwidth; /**< How much bandwidth are we willing to
                                    * tell people we have? */
  int NumCpus; /**< How many CPUs should we try to use? */
  int RunTesting; /**< If true, create testing circuits to measure how well the
                   * other ORs are running. */
  config_line_t *RendConfigLines; /**< List of configuration lines
                                          * for rendezvous services. */
  char *ContactInfo; /**< Contact info to be published in the directory */

  char *HttpProxy; /**< hostname[:port] to use as http proxy, if any */
  uint32_t HttpProxyAddr; /**< Parsed IPv4 addr for http proxy, if any */
  uint16_t HttpProxyPort; /**< Parsed port for http proxy, if any */
  char *HttpProxyAuthenticator; /**< username:password string, if any */

  char *HttpsProxy; /**< hostname[:port] to use as https proxy, if any */
  uint32_t HttpsProxyAddr; /**< Parsed IPv4 addr for https proxy, if any */
  uint16_t HttpsProxyPort; /**< Parsed port for https proxy, if any */
  char *HttpsProxyAuthenticator; /**< username:password string, if any */

  config_line_t *DirServers; /**< List of configuration lines
                                     * for directory servers. */
  char *MyFamily; /**< Declared family for this OR. */
  config_line_t *NodeFamilies; /**< List of config lines for
                                       * node families */
  config_line_t *RedirectExit; /**< List of config lines for simple
                                       * addr/port redirection */
  smartlist_t *RedirectExitList; /**< List of exit_redirect_t */
  config_line_t *AuthDirReject; /**< Address policy for descriptors to
                                 * reject. */
  config_line_t *AuthDirInvalid; /**< Address policy for descriptors to
                                  * never mark as valid. */
  char *AccountingStart; /**< How long is the accounting interval, and when
                          * does it start? */
  uint64_t AccountingMax; /**< How many bytes do we allow per accounting
                           * interval before hibernation?  0 for "never
                           * hibernate." */
  int _AccountingMaxKB; /**< How many KB do we allow per accounting
                         * interval before hibernation?  0 for "never
                         * hibernate."  (Based on a deprecated option)*/

  char *HashedControlPassword; /**< Base64-encoded hash of a password for
                                * the control system. */
  int CookieAuthentication; /**< Boolean: do we enable cookie-based auth for
                             * the control system? */
  int LeaveStreamsUnattached; /**< Boolean: Does Tor attach new streams to
                          * circuits itself (0), or does it expect a controller
                          * to cope? (1) */
  int ShutdownWaitLength; /**< When we get a SIGINT and we're a server, how
                           * long do we wait before exiting? */
  int SafeLogging; /**< Boolean: are we allowed to log sensitive strings
                    * such as addresses (0), or do we scrub them first (1)? */
  int HardwareAccel; /**< Boolean: Should we enable OpenSSL hardware
                      * acceleration where available? */
  int UseHelperNodes; /**< Boolean: Do we try to enter from a smallish number
                       * of fixed nodes? */
  int NumHelperNodes; /**< How many helper nodes do we try to establish? */
  int RephistTrackTime; /**< How many seconds do we keep rephist info? */

  addr_policy_t *reachable_addr_policy; /**< Parsed from ReachableAddresses */
} or_options_t;

/** Persistent state for an onion router, as saved to disk. */
typedef struct {
  uint32_t _magic;
  int dirty;

  /* XXXX These options aren't actually attached to anything yet. */
  time_t LastWritten;
  time_t AccountingIntervalStart;
  uint64_t AccountingBytesReadInInterval;
  uint64_t AccountingBytesWrittenInInterval;
  int AccountingSecondsActive;
  uint64_t AccountingExpectedUsage;

  config_line_t *HelperNodes;
} or_state_t;

#define MAX_SOCKS_REPLY_LEN 1024
#define MAX_SOCKS_ADDR_LEN 256
#define SOCKS_COMMAND_CONNECT 0x01
#define SOCKS_COMMAND_RESOLVE 0xF0
/** State of a SOCKS request from a user to an OP */
struct socks_request_t {
  char socks_version; /**< Which version of SOCKS did the client use? */
  int command; /**< What has the user requested? One of CONNECT or RESOLVE. */
  size_t replylen; /**< Length of <b>reply</b>. */
  char reply[MAX_SOCKS_REPLY_LEN]; /**< Write an entry into this string if
                                    * we want to specify our own socks reply,
                                    * rather than using the default socks4 or
                                    * socks5 socks reply. We use this for the
                                    * two-stage socks5 handshake.
                                    */
  int has_finished; /**< Has the SOCKS handshake finished? */
  char address[MAX_SOCKS_ADDR_LEN]; /**< What address did the client ask to connect to? */
  uint16_t port; /**< What port did the client ask to connect to? */
};

/* all the function prototypes go here */

/********************************* buffers.c ***************************/

buf_t *buf_new(void);
buf_t *buf_new_with_capacity(size_t size);
void buf_free(buf_t *buf);
void buf_clear(buf_t *buf);
void buf_shrink(buf_t *buf);

size_t buf_datalen(const buf_t *buf);
size_t buf_capacity(const buf_t *buf);
const char *_buf_peek_raw_buffer(const buf_t *buf);

int read_to_buf(int s, size_t at_most, buf_t *buf, int *reached_eof);
int read_to_buf_tls(tor_tls_t *tls, size_t at_most, buf_t *buf);

int flush_buf(int s, buf_t *buf, size_t *buf_flushlen);
int flush_buf_tls(tor_tls_t *tls, buf_t *buf, size_t *buf_flushlen);

int write_to_buf(const char *string, size_t string_len, buf_t *buf);
int fetch_from_buf(char *string, size_t string_len, buf_t *buf);
int fetch_from_buf_http(buf_t *buf,
                        char **headers_out, size_t max_headerlen,
                        char **body_out, size_t *body_used, size_t max_bodylen,
                        int force_complete);
int fetch_from_buf_socks(buf_t *buf, socks_request_t *req);
int fetch_from_buf_control0(buf_t *buf, uint32_t *len_out, uint16_t *type_out,
                            char **body_out, int check_for_v1);
int fetch_from_buf_line(buf_t *buf, char *data_out, size_t *data_len);

void assert_buf_ok(buf_t *buf);

/********************************* circuitbuild.c **********************/

char *circuit_list_path(circuit_t *circ, int verbose);
void circuit_log_path(int severity, circuit_t *circ);
void circuit_rep_hist_note_result(circuit_t *circ);
void circuit_dump_by_conn(connection_t *conn, int severity);
circuit_t *circuit_init(uint8_t purpose, int need_uptime,
                        int need_capacity, int internal);
circuit_t *circuit_establish_circuit(uint8_t purpose, extend_info_t *exit,
                                     int need_uptime, int need_capacity, int internal);
int circuit_handle_first_hop(circuit_t *circ);
void circuit_n_conn_done(connection_t *or_conn, int status);
int circuit_send_next_onion_skin(circuit_t *circ);
void circuit_note_clock_jumped(int seconds_elapsed);
int circuit_extend(cell_t *cell, circuit_t *circ);
int circuit_init_cpath_crypto(crypt_path_t *cpath, char *key_data, int reverse);
int circuit_finish_handshake(circuit_t *circ, uint8_t cell_type, char *reply);
int circuit_truncated(circuit_t *circ, crypt_path_t *layer);
int onionskin_answer(circuit_t *circ, uint8_t cell_type, char *payload, char *keys);
int circuit_all_predicted_ports_handled(time_t now, int *need_uptime,
                                        int *need_capacity);

int circuit_append_new_exit(circuit_t *circ, extend_info_t *info);
int circuit_extend_to_new_exit(circuit_t *circ, extend_info_t *info);
void onion_append_to_cpath(crypt_path_t **head_ptr, crypt_path_t *new_hop);
extend_info_t *extend_info_from_router(routerinfo_t *r);
extend_info_t *extend_info_dup(extend_info_t *info);
void extend_info_free(extend_info_t *info);
routerinfo_t *build_state_get_exit_router(cpath_build_state_t *state);
const char *build_state_get_exit_nickname(cpath_build_state_t *state);

void helper_node_set_status(const char *digest, int succeeded);
void helper_nodes_set_status_from_directory(void);
int helper_nodes_update_state(or_state_t *state);
int helper_nodes_parse_state(or_state_t *state, int set, const char **err);
int helper_nodes_getinfo_helper(const char *question, char **answer);
void helper_nodes_free_all(void);

/********************************* circuitlist.c ***********************/

circuit_t * _circuit_get_global_list(void);
const char *circuit_state_to_string(int state);
enum which_conn_changed_t { P_CONN_CHANGED=1, N_CONN_CHANGED=0 };
void circuit_set_circid_orconn(circuit_t *circ, uint16_t id,
                               connection_t *conn,
                               enum which_conn_changed_t which);
void circuit_close_all_marked(void);
circuit_t *circuit_new(uint16_t p_circ_id, connection_t *p_conn);
circuit_t *circuit_get_by_circid_orconn(uint16_t circ_id, connection_t *conn);
circuit_t *circuit_get_by_edge_conn(connection_t *conn);
circuit_t *circuit_get_by_conn(connection_t *conn);
circuit_t *circuit_get_by_global_id(uint32_t id);
circuit_t *circuit_get_by_rend_query_and_purpose(const char *rend_query, uint8_t purpose);
circuit_t *circuit_get_next_by_pk_and_purpose(circuit_t *start,
                                         const char *digest, uint8_t purpose);
circuit_t *circuit_get_rendezvous(const char *cookie);
circuit_t *circuit_get_clean_open(uint8_t purpose, int need_uptime,
                                  int need_capacity, int internal);
void circuit_mark_all_unused_circs(void);
void circuit_expire_all_dirty_circs(void);
void _circuit_mark_for_close(circuit_t *circ, int line, const char *file);

#define circuit_mark_for_close(c) \
  _circuit_mark_for_close((c), __LINE__, _SHORT_FILE_)

void assert_cpath_layer_ok(const crypt_path_t *cp);
void assert_circuit_ok(const circuit_t *c);
void circuit_free_all(void);

/********************************* circuituse.c ************************/

void circuit_expire_building(time_t now);
void circuit_remove_handled_ports(smartlist_t *needed_ports);
int circuit_stream_is_being_handled(connection_t *conn, uint16_t port, int min);
void circuit_build_needed_circs(time_t now);
void circuit_detach_stream(circuit_t *circ, connection_t *conn);
void circuit_about_to_close_connection(connection_t *conn);
void circuit_has_opened(circuit_t *circ);
void circuit_build_failed(circuit_t *circ);
circuit_t *circuit_launch_by_nickname(uint8_t purpose, const char *exit_nickname,
                                      int need_uptime, int need_capacity, int is_internal);
circuit_t *circuit_launch_by_extend_info(uint8_t purpose,
                                         extend_info_t *info,
                                         int need_uptime, int need_capacity, int is_internal);
circuit_t *circuit_launch_by_router(uint8_t purpose, routerinfo_t *exit,
                                    int need_uptime, int need_capacity, int is_internal);
void circuit_reset_failure_count(int timeout);
int connection_ap_handshake_attach_chosen_circuit(connection_t *conn,
                                                  circuit_t *circ);
int connection_ap_handshake_attach_circuit(connection_t *conn);

/********************************* command.c ***************************/

void command_process_cell(cell_t *cell, connection_t *conn);

extern unsigned long stats_n_padding_cells_processed;
extern unsigned long stats_n_create_cells_processed;
extern unsigned long stats_n_created_cells_processed;
extern unsigned long stats_n_relay_cells_processed;
extern unsigned long stats_n_destroy_cells_processed;

/********************************* config.c ***************************/

or_options_t *get_options(void);
int set_options(or_options_t *new_val);
void config_free_all(void);
const char *safe_str(const char *address);

int config_get_lines(char *string, config_line_t **result);
void config_free_lines(config_line_t *front);
int options_trial_assign(config_line_t *list, int use_defaults, int clear_first);
int resolve_my_address(or_options_t *options, uint32_t *addr,
                       char **hostname_out);
void options_init(or_options_t *options);
int options_init_from_torrc(int argc, char **argv);
int options_init_logs(or_options_t *options, int validate_only);
int config_parse_addr_policy(config_line_t *cfg,
                             addr_policy_t **dest,
                             int assume_action);
int config_cmp_addr_policies(addr_policy_t *a, addr_policy_t *b);
void options_append_default_exit_policy(addr_policy_t **policy);
void addr_policy_free(addr_policy_t *p);
int option_is_recognized(const char *key);
const char *option_get_canonical_name(const char *key);
config_line_t *option_get_assignment(or_options_t *options,
                                     const char *key);
char *options_dump(or_options_t *options, int minimal);
int options_save_current(void);
const char *get_torrc_fname(void);

or_state_t *get_or_state(void);
int or_state_load(void);
int or_state_save(void);

int config_getinfo_helper(const char *question, char **answer);

int firewall_is_fascist(void);
int fascist_firewall_allows_address(uint32_t addr, uint16_t port);

/********************************* connection.c ***************************/

const char *conn_type_to_string(int type);
const char *conn_state_to_string(int type, int state);

connection_t *connection_new(int type);
void connection_unregister(connection_t *conn);
void connection_free(connection_t *conn);
void connection_free_all(void);
void connection_about_to_close_connection(connection_t *conn);
void connection_close_immediate(connection_t *conn);
void _connection_mark_for_close(connection_t *conn,int line, const char *file);

#define connection_mark_for_close(c) \
  _connection_mark_for_close((c), __LINE__, _SHORT_FILE_)

void connection_expire_held_open(void);

int connection_connect(connection_t *conn, char *address, uint32_t addr, uint16_t port);
int retry_all_listeners(int force, smartlist_t *replaced_conns,
                        smartlist_t *new_conns);

void connection_bucket_init(void);
void connection_bucket_refill(struct timeval *now);

int connection_handle_read(connection_t *conn);

int connection_fetch_from_buf(char *string, size_t len, connection_t *conn);

int connection_wants_to_flush(connection_t *conn);
int connection_outbuf_too_full(connection_t *conn);
int connection_handle_write(connection_t *conn);
void _connection_controller_force_write(connection_t *conn);
void connection_write_to_buf(const char *string, size_t len, connection_t *conn);

connection_t *connection_or_exact_get_by_addr_port(uint32_t addr, uint16_t port);
connection_t *connection_get_by_identity_digest(const char *digest, int type);
connection_t *connection_get_by_global_id(uint32_t id);

connection_t *connection_get_by_type(int type);
connection_t *connection_get_by_type_purpose(int type, int purpose);
connection_t *connection_get_by_type_addr_port_purpose(int type, uint32_t addr,
                                                     uint16_t port, int purpose);
connection_t *connection_get_by_type_state(int type, int state);
connection_t *connection_get_by_type_state_lastwritten(int type, int state);
connection_t *connection_get_by_type_state_rendquery(int type, int state, const char *rendquery);

#define connection_speaks_cells(conn) ((conn)->type == CONN_TYPE_OR)
#define connection_has_pending_tls_data(conn) \
  ((conn)->type == CONN_TYPE_OR && \
   (conn)->state == OR_CONN_STATE_OPEN && \
   tor_tls_get_pending_bytes((conn)->tls))
int connection_is_listener(connection_t *conn);
int connection_state_is_open(connection_t *conn);
int connection_state_is_connecting(connection_t *conn);

int connection_send_destroy(uint16_t circ_id, connection_t *conn);
char *alloc_http_authenticator(const char *authenticator);

void assert_connection_ok(connection_t *conn, time_t now);
int connection_or_nonopen_was_started_here(connection_t *conn);

/********************************* connection_edge.c ***************************/

#define connection_mark_unattached_ap(conn, endreason) \
  _connection_mark_unattached_ap((conn), (endreason), __LINE__, _SHORT_FILE_)

void _connection_mark_unattached_ap(connection_t *conn, int endreason,
                                    int line, const char *file);
int connection_edge_reached_eof(connection_t *conn);
int connection_edge_process_inbuf(connection_t *conn, int package_partial);
int connection_edge_destroy(uint16_t circ_id, connection_t *conn);
int connection_edge_end(connection_t *conn, char reason, crypt_path_t *cpath_layer);
int connection_edge_end_errno(connection_t *conn, crypt_path_t *cpath_layer);
int connection_edge_finished_flushing(connection_t *conn);
int connection_edge_finished_connecting(connection_t *conn);

int connection_ap_handshake_send_begin(connection_t *ap_conn, circuit_t *circ);
int connection_ap_handshake_send_resolve(connection_t *ap_conn, circuit_t *circ);

int connection_ap_make_bridge(char *address, uint16_t port);
void connection_ap_handshake_socks_reply(connection_t *conn, char *reply,
                                         size_t replylen,
                                         socks5_reply_status_t status);
void connection_ap_handshake_socks_resolved(connection_t *conn,
                                            int answer_type,
                                            size_t answer_len,
                                            const char *answer,
                                            int ttl);

int connection_exit_begin_conn(cell_t *cell, circuit_t *circ);
int connection_exit_begin_resolve(cell_t *cell, circuit_t *circ);
void connection_exit_connect(connection_t *conn);
int connection_edge_is_rendezvous_stream(connection_t *conn);
int connection_ap_can_use_exit(connection_t *conn, routerinfo_t *exit);
void connection_ap_expire_beginning(void);
void connection_ap_attach_pending(void);
int connection_ap_detach_retriable(connection_t *conn, circuit_t *circ);

void addressmap_init(void);
void addressmap_clean(time_t now);
void addressmap_clear_configured(void);
void addressmap_clear_transient(void);
void addressmap_free_all(void);
void addressmap_rewrite(char *address, size_t maxlen);
int addressmap_already_mapped(const char *address);
void addressmap_register(const char *address, char *new_address, time_t expires);
int client_dns_incr_failures(const char *address);
void client_dns_clear_failures(const char *address);
void client_dns_set_addressmap(const char *address, uint32_t val, const char *exitname, int ttl);
int address_is_in_virtual_range(const char *addr);
const char *addressmap_register_virtual_address(int type, char *new_address);
void addressmap_get_mappings(smartlist_t *sl, time_t min_expires, time_t max_expires);

void parse_socks_policy(void);
void free_socks_policy(void);
int socks_policy_permits_address(uint32_t addr);

void set_exit_redirects(smartlist_t *lst);
typedef enum hostname_type_t {
  NORMAL_HOSTNAME, ONION_HOSTNAME, EXIT_HOSTNAME, BAD_HOSTNAME
} hostname_type_t;
hostname_type_t parse_extended_hostname(char *address);

/********************************* connection_or.c ***************************/

int connection_or_reached_eof(connection_t *conn);
int connection_or_process_inbuf(connection_t *conn);
int connection_or_finished_flushing(connection_t *conn);
int connection_or_finished_connecting(connection_t *conn);

connection_t *connection_or_connect(uint32_t addr, uint16_t port,
                                    const char *id_digest);

int connection_tls_start_handshake(connection_t *conn, int receiving);
int connection_tls_continue_handshake(connection_t *conn);

void connection_or_write_cell_to_buf(const cell_t *cell, connection_t *conn);
void connection_or_update_nickname(connection_t *conn);

/********************************* control.c ***************************/

typedef enum circuit_status_event_t {
  CIRC_EVENT_LAUNCHED = 0,
  CIRC_EVENT_BUILT    = 1,
  CIRC_EVENT_EXTENDED = 2,
  CIRC_EVENT_FAILED   = 3,
  CIRC_EVENT_CLOSED   = 4,
} circuit_status_event_t;

typedef enum stream_status_event_t {
  STREAM_EVENT_SENT_CONNECT = 0,
  STREAM_EVENT_SENT_RESOLVE = 1,
  STREAM_EVENT_SUCCEEDED    = 2,
  STREAM_EVENT_FAILED       = 3,
  STREAM_EVENT_CLOSED       = 4,
  STREAM_EVENT_NEW          = 5,
  STREAM_EVENT_NEW_RESOLVE  = 6,
  STREAM_EVENT_FAILED_RETRIABLE = 7
} stream_status_event_t;

typedef enum or_conn_status_event_t {
  OR_CONN_EVENT_LAUNCHED     = 0,
  OR_CONN_EVENT_CONNECTED    = 1,
  OR_CONN_EVENT_FAILED       = 2,
  OR_CONN_EVENT_CLOSED       = 3,
} or_conn_status_event_t;

void control_update_global_event_mask(void);
void control_adjust_event_log_severity(void);
void disable_control_logging(void);
void enable_control_logging(void);

/** Execute the statement <b>stmt</b>, which may log events concerning the
 * connection <b>conn</b>.  To prevent infinite loops, disable log messages
 * being stent to controllers if <b>conn</b> is a control connection.
 *
 * Stmt must not contain any return or goto statements.
 */
#define CONN_LOG_PROTECT(conn, stmt)                                    \
  do {                                                                  \
    int _log_conn_is_control = (conn && conn->type == CONN_TYPE_CONTROL); \
    if (_log_conn_is_control)                                           \
      disable_control_logging();                                        \
    do {stmt;} while (0);                                               \
    if (_log_conn_is_control)                                           \
      enable_control_logging();                                         \
  } while (0)

/** Log information about the connection <b>conn</b>, protecting it as with
 * CONN_LOG_PROTECT. Example:
 *
 * LOG_FN_CONN(conn, (LOG_DEBUG, "Socket %d wants to write", conn->s));
 **/
#define LOG_FN_CONN(conn, args)                 \
  CONN_LOG_PROTECT(conn, log_fn args)

int connection_control_finished_flushing(connection_t *conn);
int connection_control_reached_eof(connection_t *conn);
int connection_control_process_inbuf(connection_t *conn);

int control_event_circuit_status(circuit_t *circ, circuit_status_event_t e);
int control_event_stream_status(connection_t *conn, stream_status_event_t e);
int control_event_or_conn_status(connection_t *conn, or_conn_status_event_t e);
int control_event_bandwidth_used(uint32_t n_read, uint32_t n_written);
void control_event_logmsg(int severity, const char *msg);
int control_event_descriptors_changed(smartlist_t *routers);
int control_event_address_mapped(const char *from, const char *to,time_t expires);

int init_cookie_authentication(int enabled);
int decode_hashed_password(char *buf, const char *hashed);

/********************************* cpuworker.c *****************************/

void cpu_init(void);
void cpuworkers_rotate(void);
int connection_cpu_finished_flushing(connection_t *conn);
int connection_cpu_reached_eof(connection_t *conn);
int connection_cpu_process_inbuf(connection_t *conn);
int assign_to_cpuworker(connection_t *cpuworker, uint8_t question_type,
                        void *task);

/********************************* directory.c ***************************/

int dir_policy_permits_address(uint32_t addr);
void directory_post_to_dirservers(uint8_t purpose, const char *payload,
                                  size_t payload_len);
void directory_get_from_dirserver(uint8_t purpose, const char *resource,
                                  int retry_if_no_servers);
void directory_initiate_command_router(routerinfo_t *router, uint8_t purpose,
                                       int private_connection, const char *resource,
                                       const char *payload, size_t payload_len);

int parse_http_response(const char *headers, int *code, time_t *date,
                        int *compression, char **response);

int connection_dir_reached_eof(connection_t *conn);
int connection_dir_process_inbuf(connection_t *conn);
int connection_dir_finished_flushing(connection_t *conn);
int connection_dir_finished_connecting(connection_t *conn);
void connection_dir_request_failed(connection_t *conn);
void parse_dir_policy(void);
void free_dir_policy(void);
int dir_split_resource_into_fingerprints(const char *resource,
                               smartlist_t *fp_out, int *compresseed_out);

/********************************* dirserv.c ***************************/

void parse_authdir_policy(void);
int dirserv_add_own_fingerprint(const char *nickname, crypto_pk_env_t *pk);
int dirserv_parse_fingerprint_file(const char *fname);
void dirserv_free_fingerprint_list(void);
const char *dirserv_get_nickname_by_digest(const char *digest);
int dirserv_add_descriptor(const char *desc, const char **msg);
char *dirserver_getinfo_unregistered(const char *question);
void dirserv_free_descriptors(void);
int dirserv_thinks_router_is_blatantly_unreachable(routerinfo_t *router,
                                                   time_t now);
int list_server_status(smartlist_t *routers, char **router_status_out);
int dirserv_dump_directory_to_string(char **dir_out,
                                     crypto_pk_env_t *private_key);
void directory_set_dirty(void);
size_t dirserv_get_directory(const char **cp, int compress);
size_t dirserv_get_runningrouters(const char **rr, int compress);
void dirserv_set_cached_directory(const char *directory, time_t when,
                                  int is_running_routers);
void dirserv_set_cached_networkstatus_v2(const char *directory, const char *fp,
                                         time_t published);
int dirserv_get_networkstatus_v2(smartlist_t *result, const char *key);
void dirserv_get_routerdescs(smartlist_t *descs_out, const char *key);
void dirserv_orconn_tls_done(const char *address,
                             uint16_t or_port,
                             const char *digest_rcvd,
                             const char *nickname,
                             int as_advertised);
int authdir_wants_to_reject_router(routerinfo_t *ri,
                                   const char **msg);
void dirserv_free_all(void);

/********************************* dns.c ***************************/

void dns_init(void);
void dns_free_all(void);
int connection_dns_finished_flushing(connection_t *conn);
int connection_dns_reached_eof(connection_t *conn);
int connection_dns_process_inbuf(connection_t *conn);
void dnsworkers_rotate(void);
void connection_dns_remove(connection_t *conn);
void assert_connection_edge_not_dns_pending(connection_t *conn);
void assert_all_pending_dns_resolves_ok(void);
void dns_cancel_pending_resolve(char *question);
int dns_resolve(connection_t *exitconn);

/********************************* hibernate.c **********************/

int accounting_parse_options(or_options_t *options, int validate_only);
int accounting_is_enabled(or_options_t *options);
void configure_accounting(time_t now);
void accounting_run_housekeeping(time_t now);
void accounting_add_bytes(size_t n_read, size_t n_written, int seconds);
int accounting_record_bandwidth_usage(time_t now);
void hibernate_begin_shutdown(void);
int we_are_hibernating(void);
void consider_hibernation(time_t now);
int accounting_getinfo_helper(const char *question, char **answer);
void accounting_set_bandwidth_usage_from_state(or_state_t *state);

/********************************* main.c ***************************/

int connection_add(connection_t *conn);
int connection_remove(connection_t *conn);
int connection_in_array(connection_t *conn);
void add_connection_to_closeable_list(connection_t *conn);
int connection_is_on_closeable_list(connection_t *conn);

void get_connection_array(connection_t ***array, int *n);

void connection_watch_events(connection_t *conn, short events);
int connection_is_reading(connection_t *conn);
void connection_stop_reading(connection_t *conn);
void connection_start_reading(connection_t *conn);

int connection_is_writing(connection_t *conn);
void connection_stop_writing(connection_t *conn);
void connection_start_writing(connection_t *conn);

void directory_all_unreachable(time_t now);
void directory_info_has_arrived(time_t now, int from_cache);

int control_signal_act(int the_signal);
void handle_signals(int is_parent);
void tor_cleanup(void);
void tor_free_all(int postfork);

int tor_main(int argc, char *argv[]);

/********************************* onion.c ***************************/

int onion_pending_add(circuit_t *circ);
circuit_t *onion_next_task(void);
void onion_pending_remove(circuit_t *circ);

int onion_skin_create(crypto_pk_env_t *router_key,
                      crypto_dh_env_t **handshake_state_out,
                      char *onion_skin_out);

int onion_skin_server_handshake(const char *onion_skin,
                                crypto_pk_env_t *private_key,
                                crypto_pk_env_t *prev_private_key,
                                char *handshake_reply_out,
                                char *key_out,
                                size_t key_out_len);

int onion_skin_client_handshake(crypto_dh_env_t *handshake_state,
                                const char *handshake_reply,
                                char *key_out,
                                size_t key_out_len);

int fast_server_handshake(const char *key_in,
                          char *handshake_reply_out,
                          char *key_out,
                          size_t key_out_len);

int fast_client_handshake(const char *handshake_state,
                          const char *handshake_reply_out,
                          char *key_out,
                          size_t key_out_len);

void clear_pending_onions(void);

/********************************* relay.c ***************************/

extern unsigned long stats_n_relay_cells_relayed;
extern unsigned long stats_n_relay_cells_delivered;

int circuit_receive_relay_cell(cell_t *cell, circuit_t *circ,
                               int cell_direction);

void relay_header_pack(char *dest, const relay_header_t *src);
void relay_header_unpack(relay_header_t *dest, const char *src);
int connection_edge_send_command(connection_t *fromconn, circuit_t *circ,
                                 int relay_command, const char *payload,
                                 size_t payload_len, crypt_path_t *cpath_layer);
int connection_edge_package_raw_inbuf(connection_t *conn, int package_partial);
void connection_edge_consider_sending_sendme(connection_t *conn);
socks5_reply_status_t connection_edge_end_reason_socks5_response(int reason);
int errno_to_end_reason(int e);

extern uint64_t stats_n_data_cells_packaged;
extern uint64_t stats_n_data_bytes_packaged;
extern uint64_t stats_n_data_cells_received;
extern uint64_t stats_n_data_bytes_received;

/********************************* rephist.c ***************************/

void rep_hist_init(void);
void rep_hist_note_connect_failed(const char* nickname, time_t when);
void rep_hist_note_connect_succeeded(const char* nickname, time_t when);
void rep_hist_note_disconnect(const char* nickname, time_t when);
void rep_hist_note_connection_died(const char* nickname, time_t when);
void rep_hist_note_extend_succeeded(const char *from_name,
                                    const char *to_name);
void rep_hist_note_extend_failed(const char *from_name, const char *to_name);
void rep_hist_dump_stats(time_t now, int severity);
void rep_hist_note_bytes_read(int num_bytes, time_t when);
void rep_hist_note_bytes_written(int num_bytes, time_t when);
int rep_hist_bandwidth_assess(void);
char *rep_hist_get_bandwidth_lines(void);
void rep_history_clean(time_t before);

void rep_hist_note_used_port(uint16_t port, time_t now);
smartlist_t *rep_hist_get_predicted_ports(time_t now);
void rep_hist_note_used_hidserv(time_t now, int need_uptime, int need_capacity);
int rep_hist_get_predicted_hidserv(time_t now, int *need_uptime, int *need_capacity);
void rep_hist_note_used_resolve(time_t now);
int rep_hist_get_predicted_resolve(time_t now);

void rep_hist_free_all(void);

/********************************* rendclient.c ***************************/

void rend_client_introcirc_has_opened(circuit_t *circ);
void rend_client_rendcirc_has_opened(circuit_t *circ);
int rend_client_introduction_acked(circuit_t *circ, const char *request, size_t request_len);
void rend_client_refetch_renddesc(const char *query);
int rend_client_remove_intro_point(extend_info_t *failed_intro, const char *query);
int rend_client_rendezvous_acked(circuit_t *circ, const char *request, size_t request_len);
int rend_client_receive_rendezvous(circuit_t *circ, const char *request, size_t request_len);
void rend_client_desc_here(const char *query);

extend_info_t *rend_client_get_random_intro(const char *query);

int rend_client_send_introduction(circuit_t *introcirc, circuit_t *rendcirc);

/********************************* rendcommon.c ***************************/

/** Information used to connect to a hidden service. */
typedef struct rend_service_descriptor_t {
  crypto_pk_env_t *pk; /**< This service's public key. */
  int version; /**< 0 or 1. */
  time_t timestamp; /**< Time when the descriptor was generated. */
  uint16_t protocols; /**< Bitmask: which rendezvous protocols are supported?
                       * (We allow bits '0', '1', and '2' to be set.) */
  int n_intro_points; /**< Number of introduction points. */
  /** Array of n_intro_points elements for this service's introduction points'
   * nicknames.  Elements are removed from this array if introduction attempts
   * fail. */
  char **intro_points;
  /** Array of n_intro_points elements for this service's introduction points'
   * extend_infos, or NULL if this descriptor is V0.  Elements are removed
   * from this array if introduction attempts fail.  If this array is present,
   * its elements correspond to the elements of intro_points. */
  extend_info_t **intro_point_extend_info;
} rend_service_descriptor_t;

int rend_cmp_service_ids(const char *one, const char *two);

void rend_process_relay_cell(circuit_t *circ, int command, size_t length,
                             const char *payload);

void rend_service_descriptor_free(rend_service_descriptor_t *desc);
int rend_encode_service_descriptor(rend_service_descriptor_t *desc,
                                   int version,
                                   crypto_pk_env_t *key,
                                   char **str_out,
                                   size_t *len_out);
rend_service_descriptor_t *rend_parse_service_descriptor(const char *str, size_t len);
int rend_get_service_id(crypto_pk_env_t *pk, char *out);

/** A cached rendezvous descriptor. */
typedef struct rend_cache_entry_t {
  size_t len; /** Length of <b>desc</b> */
  time_t received; /** When was the descriptor received? */
  char *desc; /** Service descriptor */
  rend_service_descriptor_t *parsed; /* Parsed value of 'desc' */
} rend_cache_entry_t;

void rend_cache_init(void);
void rend_cache_clean(void);
void rend_cache_free_all(void);
int rend_valid_service_id(const char *query);
int rend_cache_lookup_desc(const char *query, int version, const char **desc, size_t *desc_len);
int rend_cache_lookup_entry(const char *query, int version, rend_cache_entry_t **entry_out);
int rend_cache_store(const char *desc, size_t desc_len);

/********************************* rendservice.c ***************************/

int num_rend_services(void);
int rend_config_services(or_options_t *options, int validate_only);
int rend_service_load_keys(void);
void rend_services_init(void);
void rend_services_introduce(void);
void rend_consider_services_upload(time_t now);

void rend_service_intro_has_opened(circuit_t *circuit);
int rend_service_intro_established(circuit_t *circuit, const char *request, size_t request_len);
void rend_service_rendezvous_has_opened(circuit_t *circuit);
int rend_service_introduce(circuit_t *circuit, const char *request, size_t request_len);
void rend_service_relaunch_rendezvous(circuit_t *oldcirc);
int rend_service_set_connection_addr_port(connection_t *conn, circuit_t *circ);
void rend_service_dump_stats(int severity);
void rend_service_free_all(void);

/********************************* rendmid.c *******************************/
int rend_mid_establish_intro(circuit_t *circ, const char *request, size_t request_len);
int rend_mid_introduce(circuit_t *circ, const char *request, size_t request_len);
int rend_mid_establish_rendezvous(circuit_t *circ, const char *request, size_t request_len);
int rend_mid_rendezvous(circuit_t *circ, const char *request, size_t request_len);

/********************************* router.c ***************************/
typedef enum {
  ADDR_POLICY_ACCEPTED=0,
  ADDR_POLICY_REJECTED=-1,
  ADDR_POLICY_PROBABLY_ACCEPTED=1,
  ADDR_POLICY_PROBABLY_REJECTED=2
} addr_policy_result_t;

void set_onion_key(crypto_pk_env_t *k);
crypto_pk_env_t *get_onion_key(void);
crypto_pk_env_t *get_previous_onion_key(void);
time_t get_onion_key_set_at(void);
void set_identity_key(crypto_pk_env_t *k);
crypto_pk_env_t *get_identity_key(void);
int identity_key_is_set(void);
void dup_onion_keys(crypto_pk_env_t **key, crypto_pk_env_t **last);
void rotate_onion_key(void);
crypto_pk_env_t *init_key_from_file(const char *fname);
int init_keys(void);

int check_whether_orport_reachable(void);
int check_whether_dirport_reachable(void);
void consider_testing_reachability(void);
void router_orport_found_reachable(void);
void router_dirport_found_reachable(void);
void server_has_changed_ip(void);
void consider_publishable_server(time_t now, int force);

int authdir_mode(or_options_t *options);
int clique_mode(or_options_t *options);
int server_mode(or_options_t *options);
int advertised_server_mode(void);
int proxy_mode(or_options_t *options);

void router_retry_connections(int force);
int router_is_clique_mode(routerinfo_t *router);
void router_upload_dir_desc_to_dirservers(int force);
void mark_my_descriptor_dirty_if_older_than(time_t when);
void mark_my_descriptor_dirty(void);
void check_descriptor_bandwidth_changed(time_t now);
void check_descriptor_ipaddress_changed(time_t now);
int router_compare_to_my_exit_policy(connection_t *conn);
routerinfo_t *router_get_my_routerinfo(void);
const char *router_get_my_descriptor(void);
int router_digest_is_me(const char *digest);
int router_is_me(routerinfo_t *router);
int router_fingerprint_is_me(const char *fp);
int router_rebuild_descriptor(int force);
int router_dump_router_to_string(char *s, size_t maxlen, routerinfo_t *router,
                                 crypto_pk_env_t *ident_key);
int is_legal_nickname(const char *s);
int is_legal_nickname_or_hexdigest(const char *s);
void router_reset_warnings(void);
void router_free_all(void);

/********************************* routerlist.c ***************************/

/** Represents information about a single trusted directory server. */
typedef struct trusted_dir_server_t {
  char *description;
  char *nickname;
  char *address; /**< Hostname */
  uint32_t addr; /**< IPv4 address */
  uint16_t dir_port; /**< Directory port */
  char digest[DIGEST_LEN]; /**< Digest of identity key */
  unsigned int is_running:1; /**< True iff we think this server is running. */
  unsigned int supports_v1_protocol:1; /**< True iff this server is an
                                        * authority for the older ("v1")
                                        * directory protocol.*/
  int n_networkstatus_failures; /**< How many times have we asked for this
                                 * server's network-status unsuccessfully? */
} trusted_dir_server_t;

int router_reload_router_list(void);
int router_reload_networkstatus(void);
void router_get_trusted_dir_servers(smartlist_t **outp);
routerinfo_t *router_pick_directory_server(int requireother,
                                           int fascistfirewall,
                                           int for_v2_directory,
                                           int retry_if_no_servers);
trusted_dir_server_t *router_pick_trusteddirserver(int need_v1_support,
                                                   int requireother,
                                                   int fascistfirewall,
                                                   int retry_if_no_servers);
trusted_dir_server_t *router_get_trusteddirserver_by_digest(
     const char *digest);
int all_trusted_directory_servers_down(void);
void routerlist_add_family(smartlist_t *sl, routerinfo_t *router);
void add_nickname_list_to_smartlist(smartlist_t *sl, const char *list, int warn_if_down, int warn_if_unnamed);
routerinfo_t *routerlist_find_my_routerinfo(void);
int exit_policy_implicitly_allows_local_networks(addr_policy_t *policy,
                                                 int warn);

/** How many seconds a router must be up before we'll use it for
 * reliability-critical node positions.
 */
#define ROUTER_REQUIRED_MIN_UPTIME (24*3600) /* a day */
#define ROUTER_REQUIRED_MIN_BANDWIDTH 10000

routerinfo_t *router_find_exact_exit_enclave(const char *address, uint16_t port);
int router_is_unreliable(routerinfo_t *router, int need_uptime, int need_capacity);
routerinfo_t *routerlist_sl_choose_by_bandwidth(smartlist_t *sl);
routerinfo_t *router_choose_random_node(const char *preferred,
                                        const char *excluded,
                                        smartlist_t *excludedsmartlist,
                                        int need_uptime, int need_bandwidth,
                                        int allow_unverified, int strict);
routerinfo_t *router_get_by_nickname(const char *nickname,
                                     int warn_if_unnamed);
routerinfo_t *router_get_by_hexdigest(const char *hexdigest);
routerinfo_t *router_get_by_digest(const char *digest);
int router_digest_is_trusted_dir(const char *digest);
void router_get_routerlist(routerlist_t **prouterlist);
void routerlist_reset_warnings(void);
void routerlist_free(routerlist_t *routerlist);
void routerinfo_free(routerinfo_t *router);
void routerstatus_free(routerstatus_t *routerstatus);
void networkstatus_free(networkstatus_t *networkstatus);
void routerlist_free_all(void);
routerinfo_t *routerinfo_copy(const routerinfo_t *router);
void router_mark_as_down(const char *digest);
void routerlist_remove_old_routers(int age);
void networkstatus_list_clean(time_t now);
int router_add_to_routerlist(routerinfo_t *router, const char **msg,
                             int from_cache);
int router_load_single_router(const char *s, const char **msg);
void router_load_routers_from_string(const char *s, int from_cache,
                                     smartlist_t *requested_fingerprints);
typedef enum { NS_FROM_CACHE, NS_FROM_DIR, NS_GENERATED} networkstatus_source_t;
int router_set_networkstatus(const char *s, time_t arrived_at,
                             networkstatus_source_t source,
                             smartlist_t *requested_fingerprints);
addr_policy_result_t router_compare_addr_to_addr_policy(uint32_t addr,
                              uint16_t port, addr_policy_t *policy);

int router_exit_policy_all_routers_reject(uint32_t addr, uint16_t port,
                                          int need_uptime);

int router_exit_policy_rejects_all(routerinfo_t *router);
void add_trusted_dir_server(const char *nickname,
                            const char *address, uint16_t port,
                            const char *digest, int supports_v1);
void clear_trusted_dir_servers(void);
networkstatus_t *networkstatus_get_by_digest(const char *digest);
local_routerstatus_t *router_get_combined_status_by_digest(const char *digest);
void update_networkstatus_downloads(time_t now);
void update_router_descriptor_downloads(time_t now);
void routers_update_all_from_networkstatus(void);
void routers_update_status_from_networkstatus(smartlist_t *routers,
                                              int reset_failures,
                                              int assume_recognized);
smartlist_t *router_list_superseded(void);
int router_have_minimum_dir_info(void);
void networkstatus_list_update_recent(time_t now);
void router_reset_descriptor_download_failures(void);
void router_reset_status_download_failures(void);
int router_differences_are_cosmetic(routerinfo_t *r1, routerinfo_t *r2);

/********************************* routerparse.c ************************/

#define MAX_STATUS_TAG_LEN 32
/** Structure to hold parsed Tor versions.  This is a little messier
 * than we would like it to be, because we changed version schemes with 0.1.0.
 *
 * See version-spec.txt for the whole business.
 */
typedef struct tor_version_t {
  int major;
  int minor;
  int micro;
  /** Release status.  For version in the post-0.1 format, this is always
   * VER_RELEASE. */
  enum { VER_PRE=0, VER_RC=1, VER_RELEASE=2, } status;
  int patchlevel;
  /** CVS status.  For version in the post-0.1 format, this is always
   * IS_NOT_CVS */
  enum { IS_CVS=0, IS_NOT_CVS=1} cvs;
  char status_tag[MAX_STATUS_TAG_LEN];
} tor_version_t;

typedef enum version_status_t {
  VS_RECOMMENDED=0, /**< This version is listed as recommended. */
  VS_OLD=1, /**< This version is older than any recommended version. */
  VS_NEW=2, /**< This version is newer than any recommended version. */
  VS_NEW_IN_SERIES=3, /**< This version is newer than any recommended version
                       * in its series, and such recommended versions exist. */
  VS_UNRECOMMENDED=4 /**< This version is not recommended (general case) */
} version_status_t;

int router_get_router_hash(const char *s, char *digest);
int router_get_dir_hash(const char *s, char *digest);
int router_get_runningrouters_hash(const char *s, char *digest);
int router_get_networkstatus_v2_hash(const char *s, char *digest);
int router_append_dirobj_signature(char *buf, size_t buf_len, const char *digest,
                                   crypto_pk_env_t *private_key);
int router_parse_list_from_string(const char **s,
                                  smartlist_t *dest);
int router_parse_routerlist_from_directory(const char *s,
                                           routerlist_t **dest,
                                           crypto_pk_env_t *pkey,
                                           int check_version,
                                           int write_to_cache);
int router_parse_runningrouters(const char *str);
int router_parse_directory(const char *str);
routerinfo_t *router_parse_entry_from_string(const char *s, const char *end);
int router_add_exit_policy_from_string(routerinfo_t *router, const char *s);
addr_policy_t *router_parse_addr_policy_from_string(const char *s,
                                                    int assume_action);
version_status_t tor_version_is_obsolete(const char *myversion,
                                         const char *versionlist);
version_status_t version_status_join(version_status_t a, version_status_t b);
int tor_version_parse(const char *s, tor_version_t *out);
int tor_version_as_new_as(const char *platform, const char *cutoff);
int tor_version_compare(tor_version_t *a, tor_version_t *b);
void assert_addr_policy_ok(addr_policy_t *t);
void sort_routerstatus_entries(smartlist_t *sl);

networkstatus_t *networkstatus_parse_from_string(const char *s);

#endif