aboutsummaryrefslogtreecommitdiff
path: root/src/or/or.h
blob: 701877c64bf0e3f462091a39ec177bc846780e7e (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
2243
2244
2245
2246
2247
2248
2249
2250
2251
2252
2253
2254
2255
2256
2257
2258
2259
2260
2261
2262
2263
2264
2265
2266
2267
2268
2269
2270
2271
2272
2273
2274
2275
2276
2277
2278
2279
2280
2281
2282
2283
2284
2285
2286
2287
2288
2289
2290
2291
2292
2293
2294
2295
2296
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306
2307
2308
2309
2310
2311
2312
2313
2314
2315
2316
2317
2318
2319
2320
2321
2322
2323
2324
2325
2326
2327
2328
2329
2330
2331
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341
2342
2343
2344
2345
2346
2347
2348
2349
2350
2351
2352
2353
2354
2355
2356
2357
2358
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369
2370
2371
2372
2373
2374
2375
2376
2377
2378
2379
2380
2381
2382
2383
2384
2385
2386
2387
2388
2389
2390
2391
2392
2393
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407
2408
2409
2410
2411
2412
2413
2414
2415
2416
2417
2418
2419
2420
2421
2422
2423
2424
2425
2426
2427
2428
2429
2430
2431
2432
2433
2434
2435
2436
2437
2438
2439
2440
2441
2442
2443
2444
2445
2446
2447
2448
2449
2450
2451
2452
2453
2454
2455
2456
2457
2458
2459
2460
2461
2462
2463
2464
2465
2466
2467
2468
2469
2470
2471
2472
2473
2474
2475
2476
2477
2478
2479
2480
2481
2482
2483
2484
2485
2486
2487
2488
2489
2490
2491
2492
2493
2494
2495
2496
2497
2498
2499
2500
2501
2502
2503
2504
2505
2506
2507
2508
2509
2510
2511
2512
2513
2514
2515
2516
2517
2518
2519
2520
2521
2522
2523
2524
2525
2526
2527
2528
2529
2530
2531
2532
2533
2534
2535
2536
2537
2538
2539
2540
2541
2542
2543
2544
2545
2546
2547
2548
2549
2550
2551
2552
2553
2554
2555
2556
2557
2558
2559
2560
2561
2562
2563
2564
2565
2566
2567
2568
2569
2570
2571
2572
2573
2574
2575
2576
2577
2578
2579
2580
2581
2582
2583
2584
2585
2586
2587
2588
2589
2590
2591
2592
2593
2594
2595
2596
2597
2598
2599
2600
2601
2602
2603
2604
2605
2606
2607
2608
2609
2610
2611
2612
2613
2614
2615
2616
2617
2618
2619
2620
2621
2622
2623
2624
2625
2626
2627
2628
2629
2630
2631
2632
2633
2634
2635
2636
2637
2638
2639
2640
2641
2642
2643
2644
2645
2646
2647
2648
2649
2650
2651
2652
2653
2654
2655
2656
2657
2658
2659
2660
2661
2662
2663
2664
2665
2666
2667
2668
2669
2670
2671
2672
2673
2674
2675
2676
2677
2678
2679
2680
2681
2682
2683
2684
2685
2686
2687
2688
2689
2690
2691
2692
2693
2694
2695
2696
2697
2698
2699
2700
2701
2702
2703
2704
2705
2706
2707
2708
2709
2710
2711
2712
2713
2714
2715
2716
2717
2718
2719
2720
2721
2722
2723
2724
2725
2726
2727
2728
2729
2730
2731
2732
2733
2734
2735
2736
2737
2738
2739
2740
2741
2742
2743
2744
2745
2746
2747
2748
2749
2750
2751
2752
2753
2754
2755
2756
2757
2758
2759
2760
2761
2762
2763
2764
2765
2766
2767
2768
2769
2770
2771
2772
2773
2774
2775
2776
2777
2778
2779
2780
2781
2782
2783
2784
2785
2786
2787
2788
2789
2790
2791
2792
2793
2794
2795
2796
2797
2798
2799
2800
2801
2802
2803
2804
2805
2806
2807
2808
2809
2810
2811
2812
2813
2814
2815
2816
2817
2818
2819
2820
2821
2822
2823
2824
2825
2826
2827
2828
2829
2830
2831
2832
2833
2834
2835
2836
2837
2838
2839
2840
2841
2842
2843
2844
2845
2846
2847
2848
2849
2850
2851
2852
2853
2854
2855
2856
2857
2858
2859
2860
2861
2862
2863
2864
2865
2866
2867
2868
2869
2870
2871
2872
2873
2874
2875
2876
2877
2878
2879
2880
2881
2882
2883
2884
2885
2886
2887
2888
2889
2890
2891
2892
2893
2894
2895
2896
2897
2898
2899
2900
2901
2902
2903
2904
2905
2906
2907
2908
2909
2910
2911
2912
2913
2914
2915
2916
2917
2918
2919
2920
2921
2922
2923
2924
2925
2926
2927
2928
2929
2930
2931
2932
2933
2934
2935
2936
2937
2938
2939
2940
2941
2942
2943
2944
2945
2946
2947
2948
2949
2950
2951
2952
2953
2954
2955
2956
2957
2958
2959
2960
2961
2962
2963
2964
2965
2966
2967
2968
2969
2970
2971
2972
2973
2974
2975
2976
2977
2978
2979
2980
2981
2982
2983
2984
2985
2986
2987
2988
2989
2990
2991
2992
2993
2994
2995
2996
2997
2998
2999
3000
3001
3002
3003
3004
3005
3006
3007
3008
3009
3010
3011
3012
3013
3014
3015
3016
3017
3018
3019
3020
3021
3022
3023
3024
3025
3026
3027
3028
3029
3030
3031
3032
3033
3034
3035
3036
3037
3038
3039
3040
3041
3042
3043
3044
3045
3046
3047
3048
3049
3050
3051
3052
3053
3054
3055
3056
3057
3058
3059
3060
3061
3062
3063
3064
3065
3066
3067
3068
3069
3070
3071
3072
3073
3074
3075
3076
3077
3078
3079
3080
3081
3082
3083
3084
3085
3086
3087
3088
3089
3090
3091
3092
3093
3094
3095
3096
3097
3098
3099
3100
3101
3102
3103
3104
3105
3106
3107
3108
3109
3110
3111
3112
3113
3114
3115
3116
3117
3118
3119
3120
3121
3122
3123
3124
3125
3126
3127
3128
3129
3130
3131
3132
3133
3134
3135
3136
3137
3138
3139
3140
3141
3142
3143
3144
3145
3146
3147
3148
3149
3150
3151
3152
3153
3154
3155
3156
3157
3158
3159
3160
3161
3162
3163
3164
3165
3166
3167
3168
3169
3170
3171
3172
3173
3174
3175
3176
3177
3178
3179
3180
3181
3182
3183
3184
3185
3186
3187
3188
3189
3190
3191
3192
3193
3194
3195
3196
3197
3198
3199
3200
3201
3202
3203
3204
3205
3206
3207
3208
3209
3210
3211
3212
3213
3214
3215
3216
3217
3218
3219
3220
3221
3222
3223
3224
3225
3226
3227
3228
3229
3230
3231
3232
3233
3234
3235
3236
3237
3238
3239
3240
3241
3242
3243
3244
3245
3246
3247
3248
3249
3250
3251
3252
3253
3254
3255
3256
3257
3258
3259
3260
3261
3262
3263
3264
3265
3266
3267
3268
3269
3270
3271
3272
3273
3274
3275
3276
3277
3278
3279
3280
3281
3282
3283
3284
3285
3286
3287
3288
3289
3290
3291
3292
3293
3294
3295
3296
3297
3298
3299
3300
3301
3302
3303
3304
3305
3306
3307
3308
3309
3310
3311
3312
3313
3314
3315
3316
3317
3318
3319
3320
3321
3322
3323
3324
3325
3326
3327
3328
3329
3330
3331
3332
3333
3334
3335
3336
3337
3338
3339
3340
3341
3342
3343
3344
3345
3346
3347
3348
3349
3350
3351
3352
3353
3354
3355
3356
3357
3358
3359
3360
3361
3362
3363
3364
3365
3366
3367
3368
3369
3370
3371
3372
3373
3374
3375
3376
3377
3378
3379
3380
3381
3382
3383
3384
3385
3386
3387
3388
3389
3390
3391
3392
3393
3394
3395
3396
3397
3398
3399
3400
3401
3402
3403
3404
3405
3406
3407
3408
3409
3410
3411
3412
3413
3414
3415
3416
3417
3418
3419
3420
3421
3422
3423
3424
3425
3426
3427
3428
3429
3430
3431
3432
3433
3434
3435
3436
3437
3438
3439
3440
3441
3442
3443
3444
3445
3446
3447
3448
3449
3450
3451
3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
3587
3588
3589
3590
3591
3592
3593
3594
3595
3596
3597
3598
3599
3600
3601
3602
3603
3604
3605
3606
3607
3608
3609
3610
3611
3612
3613
3614
3615
3616
3617
3618
3619
3620
3621
3622
3623
3624
3625
3626
3627
3628
3629
3630
3631
3632
3633
3634
3635
3636
3637
3638
3639
3640
3641
3642
3643
3644
3645
3646
3647
3648
3649
3650
3651
3652
3653
3654
3655
3656
3657
3658
3659
3660
3661
3662
3663
3664
3665
3666
3667
3668
3669
3670
3671
3672
3673
3674
3675
3676
3677
3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
3740
3741
3742
3743
3744
3745
3746
3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
3803
3804
3805
3806
3807
3808
3809
3810
3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
3836
3837
3838
3839
3840
3841
3842
3843
3844
3845
3846
3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
3864
3865
3866
3867
3868
3869
3870
3871
3872
3873
3874
3875
3876
3877
3878
3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
3934
3935
3936
3937
3938
3939
3940
3941
3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
4001
4002
4003
4004
4005
4006
4007
4008
4009
4010
4011
4012
4013
4014
4015
4016
4017
4018
4019
4020
4021
4022
4023
4024
4025
4026
4027
4028
4029
4030
4031
4032
4033
4034
4035
4036
4037
4038
4039
4040
4041
4042
4043
4044
4045
4046
4047
4048
4049
4050
4051
4052
4053
4054
4055
4056
4057
4058
4059
4060
4061
4062
4063
4064
4065
4066
4067
4068
4069
4070
4071
4072
4073
4074
4075
4076
4077
4078
4079
4080
4081
4082
4083
4084
4085
4086
4087
4088
4089
4090
4091
4092
4093
4094
4095
4096
4097
4098
4099
4100
4101
4102
4103
4104
4105
4106
4107
4108
4109
4110
4111
4112
4113
4114
4115
4116
4117
4118
4119
4120
4121
4122
4123
4124
4125
4126
4127
4128
4129
4130
4131
4132
4133
4134
4135
4136
4137
4138
4139
4140
4141
4142
4143
4144
4145
4146
4147
4148
4149
4150
4151
4152
4153
4154
4155
4156
4157
4158
4159
4160
4161
4162
4163
4164
4165
4166
4167
4168
4169
4170
4171
4172
4173
4174
4175
4176
4177
4178
4179
4180
4181
4182
4183
4184
4185
4186
4187
4188
4189
4190
4191
4192
4193
4194
4195
4196
4197
4198
4199
4200
4201
4202
4203
4204
4205
4206
4207
4208
4209
4210
4211
4212
4213
4214
4215
4216
4217
4218
4219
4220
4221
4222
4223
4224
4225
4226
4227
4228
4229
4230
4231
4232
4233
4234
4235
4236
4237
4238
4239
4240
4241
4242
4243
4244
4245
4246
4247
4248
4249
4250
4251
4252
4253
4254
4255
4256
4257
4258
4259
4260
4261
4262
4263
4264
4265
4266
4267
4268
4269
4270
4271
4272
4273
4274
4275
4276
4277
4278
4279
4280
4281
4282
4283
4284
4285
4286
4287
4288
4289
4290
4291
4292
4293
4294
4295
4296
4297
4298
4299
4300
4301
4302
4303
4304
4305
4306
4307
4308
4309
4310
4311
4312
4313
4314
4315
4316
4317
4318
4319
4320
4321
4322
4323
4324
4325
4326
4327
4328
4329
4330
4331
4332
4333
4334
4335
4336
4337
4338
4339
4340
4341
4342
4343
4344
4345
4346
4347
4348
4349
4350
4351
4352
4353
4354
4355
4356
4357
4358
4359
4360
4361
4362
4363
4364
4365
4366
4367
4368
4369
4370
4371
4372
4373
4374
4375
4376
4377
4378
4379
4380
4381
4382
4383
4384
4385
4386
4387
4388
4389
4390
4391
4392
4393
4394
4395
4396
4397
4398
4399
4400
4401
4402
4403
4404
4405
4406
4407
4408
4409
4410
4411
4412
4413
4414
4415
4416
4417
4418
4419
4420
4421
4422
4423
4424
4425
4426
4427
4428
4429
4430
4431
4432
4433
4434
4435
4436
4437
4438
4439
4440
4441
4442
4443
4444
4445
4446
4447
4448
4449
4450
4451
4452
4453
4454
4455
4456
4457
4458
4459
4460
4461
4462
4463
4464
4465
4466
4467
4468
4469
4470
4471
4472
4473
4474
4475
4476
4477
4478
4479
4480
4481
4482
4483
4484
4485
4486
4487
4488
4489
4490
4491
4492
4493
4494
4495
4496
4497
4498
4499
4500
4501
4502
4503
4504
4505
4506
4507
4508
4509
4510
4511
4512
4513
4514
4515
4516
4517
4518
4519
4520
4521
4522
4523
4524
4525
4526
4527
4528
4529
4530
4531
4532
4533
4534
4535
4536
4537
4538
4539
4540
4541
4542
4543
4544
4545
4546
4547
4548
4549
4550
4551
4552
4553
4554
4555
4556
4557
4558
4559
4560
4561
4562
4563
4564
4565
4566
4567
4568
4569
4570
4571
4572
4573
4574
4575
4576
4577
4578
4579
4580
4581
4582
4583
4584
4585
4586
4587
4588
4589
4590
4591
4592
4593
4594
4595
4596
4597
4598
4599
4600
4601
4602
4603
4604
4605
4606
4607
4608
4609
4610
4611
4612
4613
4614
4615
4616
4617
4618
4619
4620
4621
4622
4623
4624
4625
4626
4627
4628
4629
4630
4631
4632
4633
4634
4635
4636
4637
4638
4639
4640
4641
4642
4643
4644
4645
4646
4647
4648
4649
4650
4651
4652
4653
4654
4655
4656
4657
4658
4659
4660
4661
4662
4663
4664
4665
4666
4667
4668
4669
4670
4671
4672
4673
4674
4675
4676
4677
4678
4679
4680
4681
4682
4683
4684
4685
4686
4687
4688
4689
4690
4691
4692
4693
4694
4695
4696
4697
4698
4699
4700
4701
4702
4703
4704
4705
4706
4707
4708
4709
4710
4711
4712
4713
4714
4715
4716
4717
4718
4719
4720
4721
4722
4723
4724
4725
4726
4727
4728
4729
4730
4731
4732
4733
4734
4735
4736
4737
4738
4739
4740
4741
4742
4743
4744
4745
4746
4747
4748
4749
4750
4751
4752
4753
4754
4755
4756
4757
4758
4759
4760
4761
4762
4763
4764
4765
4766
4767
4768
4769
4770
4771
4772
4773
4774
4775
4776
4777
4778
4779
4780
4781
4782
4783
4784
4785
4786
4787
4788
4789
4790
4791
4792
4793
4794
4795
4796
4797
4798
4799
4800
4801
4802
4803
4804
4805
4806
4807
4808
4809
4810
4811
4812
4813
4814
4815
4816
4817
4818
4819
4820
4821
4822
4823
4824
4825
4826
4827
4828
4829
4830
4831
4832
4833
4834
4835
4836
4837
4838
4839
4840
4841
4842
4843
4844
4845
4846
4847
4848
4849
4850
4851
4852
4853
4854
4855
4856
4857
4858
4859
4860
4861
4862
4863
4864
4865
4866
4867
4868
4869
4870
4871
4872
4873
4874
4875
4876
4877
4878
4879
4880
4881
4882
4883
4884
4885
4886
4887
4888
4889
4890
4891
4892
4893
4894
4895
4896
4897
4898
4899
4900
4901
4902
4903
4904
4905
4906
4907
4908
4909
4910
4911
4912
4913
4914
4915
4916
4917
4918
4919
4920
4921
4922
4923
4924
4925
4926
4927
4928
4929
4930
4931
4932
4933
4934
4935
4936
4937
4938
4939
4940
4941
4942
4943
4944
4945
4946
4947
4948
4949
4950
4951
4952
4953
4954
4955
4956
4957
4958
4959
4960
4961
4962
4963
4964
4965
4966
4967
4968
4969
4970
4971
4972
4973
4974
4975
4976
4977
4978
4979
4980
4981
4982
4983
4984
4985
4986
4987
4988
4989
4990
4991
4992
4993
4994
4995
4996
4997
4998
4999
5000
5001
5002
5003
5004
5005
5006
5007
5008
5009
5010
5011
5012
5013
5014
5015
5016
5017
5018
5019
5020
5021
/* Copyright (c) 2001 Matej Pfajfar.
 * Copyright (c) 2001-2004, Roger Dingledine.
 * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
 * Copyright (c) 2007-2013, The Tor Project, Inc. */
/* See LICENSE for licensing information */

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

#ifndef TOR_OR_H
#define TOR_OR_H

#include "orconfig.h"

#ifdef __COVERITY__
/* If we're building for a static analysis, turn on all the off-by-default
 * features. */
#ifndef INSTRUMENT_DOWNLOADS
#define INSTRUMENT_DOWNLOADS 1
#endif
#endif

#ifdef _WIN32
#ifndef _WIN32_WINNT
#define _WIN32_WINNT 0x0501
#endif
#define WIN32_LEAN_AND_MEAN
#endif

#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h> /* FreeBSD needs this to know what version it is */
#endif
#include "torint.h"
#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_UN_H
#include <sys/un.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

#ifdef _WIN32
#include <io.h>
#include <process.h>
#include <direct.h>
#include <windows.h>
#endif

#ifdef USE_BUFFEREVENTS
#include <event2/bufferevent.h>
#include <event2/buffer.h>
#include <event2/util.h>
#endif

#include "crypto.h"
#include "tortls.h"
#include "../common/torlog.h"
#include "container.h"
#include "torgzip.h"
#include "address.h"
#include "compat_libevent.h"
#include "ht.h"
#include "replaycache.h"
#include "crypto_curve25519.h"
#include "tor_queue.h"

/* These signals are defined to help handle_control_signal work.
 */
#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
/* Controller signals start at a high number so we don't
 * conflict with system-defined signals. */
#define SIGNEWNYM 129
#define SIGCLEARDNSCACHE 130

#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

#ifdef ENABLE_TOR2WEB_MODE
#define NON_ANONYMOUS_MODE_ENABLED 1
#endif

/** Length of longest allowable configured nickname. */
#define MAX_NICKNAME_LEN 19
/** Length of a router identity encoded as a hexadecimal digest, plus
 * possible dollar sign. */
#define MAX_HEX_NICKNAME_LEN (HEX_DIGEST_LEN+1)
/** Maximum length of verbose router identifier: dollar sign, hex ID digest,
 * equal sign or tilde, nickname. */
#define MAX_VERBOSE_NICKNAME_LEN (1+HEX_DIGEST_LEN+1+MAX_NICKNAME_LEN)

/** Maximum size, in bytes, for resized buffers. */
#define MAX_BUF_SIZE ((1<<24)-1) /* 16MB-1 */
/** Maximum size, in bytes, for any directory object that we've downloaded. */
#define MAX_DIR_DL_SIZE MAX_BUF_SIZE

/** For HTTP parsing: Maximum number of bytes we'll accept in the headers
 * of an HTTP request or response. */
#define MAX_HEADERS_SIZE 50000
/** Maximum size, in bytes, for any directory object that we're accepting
 * as an upload. */
#define MAX_DIR_UL_SIZE MAX_BUF_SIZE

/** Maximum size, in bytes, of a single router descriptor uploaded to us
 * as a directory authority. Caches and clients fetch whatever descriptors
 * the authorities tell them to fetch, and don't care about size. */
#define MAX_DESCRIPTOR_UPLOAD_SIZE 20000

/** Maximum size of a single extrainfo document, as above. */
#define MAX_EXTRAINFO_UPLOAD_SIZE 50000

/** How long do we keep DNS cache entries before purging them (regardless of
 * their TTL)? */
#define MAX_DNS_ENTRY_AGE (30*60)
/** How long do we cache/tell clients to cache DNS records when no TTL is
 * known? */
#define DEFAULT_DNS_TTL (30*60)
/** How long can a TTL be before we stop believing it? */
#define MAX_DNS_TTL (3*60*60)
/** How small can a TTL be before we stop believing it?  Provides rudimentary
 * pinning. */
#define MIN_DNS_TTL 60

/** How often do we rotate onion keys? */
#define MIN_ONION_KEY_LIFETIME (7*24*60*60)
/** How often do we rotate TLS contexts? */
#define MAX_SSL_KEY_LIFETIME_INTERNAL (2*60*60)

/** How old do we allow a router to get before removing it
 * from the router list? In seconds. */
#define ROUTER_MAX_AGE (60*60*48)
/** How old can a router get before we (as a server) will no longer
 * consider it live? In seconds. */
#define ROUTER_MAX_AGE_TO_PUBLISH (60*60*24)
/** How old do we let a saved descriptor get before force-removing it? */
#define OLD_ROUTER_DESC_MAX_AGE (60*60*24*5)

/** Possible rules for generating circuit IDs on an OR connection. */
typedef enum {
  CIRC_ID_TYPE_LOWER=0, /**< Pick from 0..1<<15-1. */
  CIRC_ID_TYPE_HIGHER=1, /**< Pick from 1<<15..1<<16-1. */
  /** The other side of a connection is an OP: never create circuits to it,
   * and let it use any circuit ID it wants. */
  CIRC_ID_TYPE_NEITHER=2
} circ_id_type_t;
#define circ_id_type_bitfield_t ENUM_BF(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 CPU worker process. */
#define CONN_TYPE_CPUWORKER 10
/** Type for listening for connections from user interface process. */
#define CONN_TYPE_CONTROL_LISTENER 11
/** Type for connections from user interface process. */
#define CONN_TYPE_CONTROL 12
/** Type for sockets listening for transparent connections redirected by pf or
 * netfilter. */
#define CONN_TYPE_AP_TRANS_LISTENER 13
/** Type for sockets listening for transparent connections redirected by
 * natd. */
#define CONN_TYPE_AP_NATD_LISTENER 14
/** Type for sockets listening for DNS requests. */
#define CONN_TYPE_AP_DNS_LISTENER 15

/** Type for connections from the Extended ORPort. */
#define CONN_TYPE_EXT_OR 16
/** Type for sockets listening for Extended ORPort connections. */
#define CONN_TYPE_EXT_OR_LISTENER 17

#define CONN_TYPE_MAX_ 17
/* !!!! If _CONN_TYPE_MAX is ever over 31, we must grow the type field in
 * connection_t. */

/* Proxy client types */
#define PROXY_NONE 0
#define PROXY_CONNECT 1
#define PROXY_SOCKS4 2
#define PROXY_SOCKS5 3
/* !!!! If there is ever a PROXY_* type over 2, we must grow the proxy_type
 * field in or_connection_t */

/* Pluggable transport proxy type. Don't use this in or_connection_t,
 * instead use the actual underlying proxy type (see above).  */
#define PROXY_PLUGGABLE 4

/* Proxy client handshake states */
/* We use a proxy but we haven't even connected to it yet. */
#define PROXY_INFANT 1
/* We use an HTTP proxy and we've sent the CONNECT command. */
#define PROXY_HTTPS_WANT_CONNECT_OK 2
/* We use a SOCKS4 proxy and we've sent the CONNECT command. */
#define PROXY_SOCKS4_WANT_CONNECT_OK 3
/* We use a SOCKS5 proxy and we try to negotiate without
   any authentication . */
#define PROXY_SOCKS5_WANT_AUTH_METHOD_NONE 4
/* We use a SOCKS5 proxy and we try to negotiate with
   Username/Password authentication . */
#define PROXY_SOCKS5_WANT_AUTH_METHOD_RFC1929 5
/* We use a SOCKS5 proxy and we just sent our credentials. */
#define PROXY_SOCKS5_WANT_AUTH_RFC1929_OK 6
/* We use a SOCKS5 proxy and we just sent our CONNECT command. */
#define PROXY_SOCKS5_WANT_CONNECT_OK 7
/* We use a proxy and we CONNECTed successfully!. */
#define PROXY_CONNECTED 8

/** True iff <b>x</b> is an edge connection. */
#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 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 CPUWORKER_TASK_SHUTDOWN 255

#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 handshake to complete */
#define OR_CONN_STATE_PROXY_HANDSHAKING 2
/** State for an OR connection client: SSL is handshaking, not done
 * yet. */
#define OR_CONN_STATE_TLS_HANDSHAKING 3
/** State for a connection to an OR: We're doing a second SSL handshake for
 * renegotiation purposes. (V2 handshake only.) */
#define OR_CONN_STATE_TLS_CLIENT_RENEGOTIATING 4
/** State for a connection at an OR: We're waiting for the client to
 * renegotiate (to indicate a v2 handshake) or send a versions cell (to
 * indicate a v3 handshake) */
#define OR_CONN_STATE_TLS_SERVER_RENEGOTIATING 5
/** State for an OR connection: We're done with our SSL handshake, we've done
 * renegotiation, but we haven't yet negotiated link protocol versions and
 * sent a netinfo cell. */
#define OR_CONN_STATE_OR_HANDSHAKING_V2 6
/** State for an OR connection: We're done with our SSL handshake, but we
 * haven't yet negotiated link protocol versions, done a V3 handshake, and
 * sent a netinfo cell. */
#define OR_CONN_STATE_OR_HANDSHAKING_V3 7
/** State for an OR connection: Ready to send/receive cells. */
#define OR_CONN_STATE_OPEN 8
#define OR_CONN_STATE_MAX_ 8

/** States of the Extended ORPort protocol. Be careful before changing
 *  the numbers: they matter. */
#define EXT_OR_CONN_STATE_MIN_ 1
/** Extended ORPort authentication is waiting for the authentication
 *  type selected by the client. */
#define EXT_OR_CONN_STATE_AUTH_WAIT_AUTH_TYPE 1
/** Extended ORPort authentication is waiting for the client nonce. */
#define EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_NONCE 2
/** Extended ORPort authentication is waiting for the client hash. */
#define EXT_OR_CONN_STATE_AUTH_WAIT_CLIENT_HASH 3
#define EXT_OR_CONN_STATE_AUTH_MAX 3
/** Authentication finished and the Extended ORPort is now accepting
 *  traffic. */
#define EXT_OR_CONN_STATE_OPEN 4
/** Extended ORPort is flushing its last messages and preparing to
 *  start accepting OR connections. */
#define EXT_OR_CONN_STATE_FLUSHING 5
#define EXT_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 descriptor. */
#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: sent 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
/** State for a transparent natd connection: waiting for original
 * destination. */
#define AP_CONN_STATE_NATD_WAIT 12
#define AP_CONN_STATE_MAX_ 12

/** True iff the AP_CONN_STATE_* value <b>s</b> means that the corresponding
 * edge connection is not attached to any circuit. */
#define AP_CONN_STATE_IS_UNATTACHED(s) \
  ((s) <= AP_CONN_STATE_CIRCUIT_WAIT || (s) == AP_CONN_STATE_NATD_WAIT)

#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

/** True iff the purpose of <b>conn</b> means that it's a server-side
 * directory connection. */
#define DIR_CONN_IS_SERVER(conn) ((conn)->purpose == DIR_PURPOSE_SERVER)

#define CONTROL_CONN_STATE_MIN_ 1
/** State for a control connection: Authenticated and accepting v1 commands. */
#define CONTROL_CONN_STATE_OPEN 1
/** State for a control connection: Waiting for authentication; speaking
 * protocol v1. */
#define CONTROL_CONN_STATE_NEEDAUTH 2
#define CONTROL_CONN_STATE_MAX_ 2

#define DIR_PURPOSE_MIN_ 4
/** A connection to a directory server: set after a v2 rendezvous
 * descriptor is downloaded. */
#define DIR_PURPOSE_HAS_FETCHED_RENDDESC_V2 4
/** A connection to a directory server: download one or more server
 * descriptors. */
#define DIR_PURPOSE_FETCH_SERVERDESC 6
/** A connection to a directory server: download one or more extra-info
 * documents. */
#define DIR_PURPOSE_FETCH_EXTRAINFO 7
/** A connection to a directory server: upload a server descriptor. */
#define DIR_PURPOSE_UPLOAD_DIR 8
/** A connection to a directory server: upload a v3 networkstatus vote. */
#define DIR_PURPOSE_UPLOAD_VOTE 10
/** A connection to a directory server: upload a v3 consensus signature */
#define DIR_PURPOSE_UPLOAD_SIGNATURES 11
/** A connection to a directory server: download one or more v3 networkstatus
 * votes. */
#define DIR_PURPOSE_FETCH_STATUS_VOTE 12
/** A connection to a directory server: download a v3 detached signatures
 * object for a consensus. */
#define DIR_PURPOSE_FETCH_DETACHED_SIGNATURES 13
/** A connection to a directory server: download a v3 networkstatus
 * consensus. */
#define DIR_PURPOSE_FETCH_CONSENSUS 14
/** A connection to a directory server: download one or more directory
 * authority certificates. */
#define DIR_PURPOSE_FETCH_CERTIFICATE 15

/** Purpose for connection at a directory server. */
#define DIR_PURPOSE_SERVER 16
/** A connection to a hidden service directory server: upload a v2 rendezvous
 * descriptor. */
#define DIR_PURPOSE_UPLOAD_RENDDESC_V2 17
/** A connection to a hidden service directory server: download a v2 rendezvous
 * descriptor. */
#define DIR_PURPOSE_FETCH_RENDDESC_V2 18
/** A connection to a directory server: download a microdescriptor. */
#define DIR_PURPOSE_FETCH_MICRODESC 19
#define DIR_PURPOSE_MAX_ 19

/** True iff <b>p</b> is a purpose corresponding to uploading data to a
 * directory server. */
#define DIR_PURPOSE_IS_UPLOAD(p)                \
  ((p)==DIR_PURPOSE_UPLOAD_DIR ||               \
   (p)==DIR_PURPOSE_UPLOAD_VOTE ||              \
   (p)==DIR_PURPOSE_UPLOAD_SIGNATURES)

#define EXIT_PURPOSE_MIN_ 1
/** This exit stream wants to do an ordinary connect. */
#define EXIT_PURPOSE_CONNECT 1
/** This exit stream wants to do a resolve (either normal or reverse). */
#define EXIT_PURPOSE_RESOLVE 2
#define EXIT_PURPOSE_MAX_ 2

/* !!!! If any connection purpose is ever over 31, we must grow the type
 * field in connection_t. */

/** Circuit state: I'm the origin, 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_chan is still
 * connecting. */
#define CIRCUIT_STATE_CHAN_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
/** This circuit is used for build time measurement only */
#define CIRCUIT_PURPOSE_C_MEASURE_TIMEOUT 13
#define CIRCUIT_PURPOSE_C_MAX_ 13
/** Hidden-service-side circuit purpose: at Bob, waiting for introductions. */
#define CIRCUIT_PURPOSE_S_ESTABLISH_INTRO 14
/** Hidden-service-side circuit purpose: at Bob, successfully established
 * intro. */
#define CIRCUIT_PURPOSE_S_INTRO 15
/** Hidden-service-side circuit purpose: at Bob, connecting to rend point. */
#define CIRCUIT_PURPOSE_S_CONNECT_REND 16
/** Hidden-service-side circuit purpose: at Bob, rendezvous established. */
#define CIRCUIT_PURPOSE_S_REND_JOINED 17
/** A testing circuit; not meant to be used for actual traffic. */
#define CIRCUIT_PURPOSE_TESTING 18
/** A controller made this circuit and Tor should not use it. */
#define CIRCUIT_PURPOSE_CONTROLLER 19
/** This circuit is used for path bias probing only */
#define CIRCUIT_PURPOSE_PATH_BIAS_TESTING 20
#define CIRCUIT_PURPOSE_MAX_ 20
/** A catch-all for unrecognized purposes. Currently we don't expect
 * to make or see any circuits with this purpose. */
#define CIRCUIT_PURPOSE_UNKNOWN 255

/** True iff the circuit purpose <b>p</b> is for a circuit that
 * originated at this node. */
#define CIRCUIT_PURPOSE_IS_ORIGIN(p) ((p)>CIRCUIT_PURPOSE_OR_MAX_)
/** True iff the circuit purpose <b>p</b> is for a circuit that originated
 * here to serve as a client.  (Hidden services don't count here.) */
#define CIRCUIT_PURPOSE_IS_CLIENT(p)  \
  ((p)> CIRCUIT_PURPOSE_OR_MAX_ &&    \
   (p)<=CIRCUIT_PURPOSE_C_MAX_)
/** True iff the circuit_t <b>c</b> is actually an origin_circuit_t. */
#define CIRCUIT_IS_ORIGIN(c) (CIRCUIT_PURPOSE_IS_ORIGIN((c)->purpose))
/** True iff the circuit purpose <b>p</b> is for an established rendezvous
 * circuit. */
#define CIRCUIT_PURPOSE_IS_ESTABLISHED_REND(p) \
  ((p) == CIRCUIT_PURPOSE_C_REND_JOINED ||     \
   (p) == CIRCUIT_PURPOSE_S_REND_JOINED)
/** True iff the circuit_t c is actually an or_circuit_t */
#define CIRCUIT_IS_ORCIRC(c) (((circuit_t *)(c))->magic == OR_CIRCUIT_MAGIC)

/** How many circuits do we want simultaneously in-progress to handle
 * a given stream? */
#define MIN_CIRCUITS_HANDLING_STREAM 2

/* These RELAY_COMMAND constants define values for relay cell commands, and
* must match those defined in tor-spec.txt. */
#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_BEGIN_DIR 13
#define RELAY_COMMAND_EXTEND2 14
#define RELAY_COMMAND_EXTENDED2 15

#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

/* Reasons why an OR connection is closed. */
#define END_OR_CONN_REASON_DONE           1
#define END_OR_CONN_REASON_REFUSED        2 /* connection refused */
#define END_OR_CONN_REASON_OR_IDENTITY    3
#define END_OR_CONN_REASON_CONNRESET      4 /* connection reset by peer */
#define END_OR_CONN_REASON_TIMEOUT        5
#define END_OR_CONN_REASON_NO_ROUTE       6 /* no route to host/net */
#define END_OR_CONN_REASON_IO_ERROR       7 /* read/write error */
#define END_OR_CONN_REASON_RESOURCE_LIMIT 8 /* sockets, buffers, etc */
#define END_OR_CONN_REASON_PT_MISSING     9 /* PT failed or not available */
#define END_OR_CONN_REASON_MISC           10

/* Reasons why we (or a remote OR) might close a stream. See tor-spec.txt for
 * documentation of these.  The values must match. */
#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
#define END_STREAM_REASON_NOROUTE 8
#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
#define END_STREAM_REASON_NOTDIRECTORY 14
#define END_STREAM_REASON_ENTRYPOLICY 15

/* 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. */
/* XXXX 256 is no longer used; feel free to reuse it. */
/** We were unable to attach the connection to any circuit at all. */
/* XXXX the ways we use this one don't make a lot of sense. */
#define END_STREAM_REASON_CANT_ATTACH 257
/** We can't connect to any directories at all, so we killed our streams
 * before they can time out. */
#define END_STREAM_REASON_NET_UNREACHABLE 258
/** This is a SOCKS connection, and the client used (or misused) the SOCKS
 * protocol in a way we couldn't handle. */
#define END_STREAM_REASON_SOCKSPROTOCOL 259
/** This is a transparent proxy connection, but we can't extract the original
 * target address:port. */
#define END_STREAM_REASON_CANT_FETCH_ORIG_DEST 260
/** This is a connection on the NATD port, and the destination IP:Port was
 * either ill-formed or out-of-range. */
#define END_STREAM_REASON_INVALID_NATD_DEST 261
/** The target address is in a private network (like 127.0.0.1 or 10.0.0.1);
 * you don't want to do that over a randomly chosen exit */
#define END_STREAM_REASON_PRIVATE_ADDR 262

/** Bitwise-and this value with endreason to mask out all flags. */
#define END_STREAM_REASON_MASK 511

/** Bitwise-or this with the argument to control_event_stream_status
 * to indicate that the reason came from an END cell. */
#define END_STREAM_REASON_FLAG_REMOTE 512
/** Bitwise-or this with the argument to control_event_stream_status
 * to indicate that we already sent a CLOSED stream event. */
#define END_STREAM_REASON_FLAG_ALREADY_SENT_CLOSED 1024
/** Bitwise-or this with endreason to indicate that we already sent
 * a socks reply, and no further reply needs to be sent from
 * connection_mark_unattached_ap(). */
#define END_STREAM_REASON_FLAG_ALREADY_SOCKS_REPLIED 2048

/** Reason for remapping an AP connection's address: we have a cached
 * answer. */
#define REMAP_STREAM_SOURCE_CACHE 1
/** Reason for remapping an AP connection's address: the exit node told us an
 * answer. */
#define REMAP_STREAM_SOURCE_EXIT 2

/* 'type' values to use in RESOLVED cells.  Specified in tor-spec.txt. */
#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

/* Negative reasons are internal: we never send them in a DESTROY or TRUNCATE
 * call; they only go to the controller for tracking  */
/** Our post-timeout circuit time measurement period expired.
 * We must give up now */
#define END_CIRC_REASON_MEASUREMENT_EXPIRED -3

/** We couldn't build a path for this circuit. */
#define END_CIRC_REASON_NOPATH          -2
/** Catch-all "other" reason for closing origin circuits. */
#define END_CIRC_AT_ORIGIN              -1

/* Reasons why we (or a remote OR) might close a circuit. See tor-spec.txt for
 * documentation of these. */
#define END_CIRC_REASON_MIN_            0
#define END_CIRC_REASON_NONE            0
#define END_CIRC_REASON_TORPROTOCOL     1
#define END_CIRC_REASON_INTERNAL        2
#define END_CIRC_REASON_REQUESTED       3
#define END_CIRC_REASON_HIBERNATING     4
#define END_CIRC_REASON_RESOURCELIMIT   5
#define END_CIRC_REASON_CONNECTFAILED   6
#define END_CIRC_REASON_OR_IDENTITY     7
#define END_CIRC_REASON_CHANNEL_CLOSED  8
#define END_CIRC_REASON_FINISHED        9
#define END_CIRC_REASON_TIMEOUT         10
#define END_CIRC_REASON_DESTROYED       11
#define END_CIRC_REASON_NOSUCHSERVICE   12
#define END_CIRC_REASON_MAX_            12

/** Bitwise-OR this with the argument to circuit_mark_for_close() or
 * control_event_circuit_status() to indicate that the reason was
 * passed through from a destroy or truncate cell. */
#define END_CIRC_REASON_FLAG_REMOTE     512

/** Length of 'y' portion of 'y.onion' URL. */
#define REND_SERVICE_ID_LEN_BASE32 16

/** Length of 'y.onion' including '.onion' URL. */
#define REND_SERVICE_ADDRESS_LEN (16+1+5)

/** Length of a binary-encoded rendezvous service ID. */
#define REND_SERVICE_ID_LEN 10

/** Time period for which a v2 descriptor will be valid. */
#define REND_TIME_PERIOD_V2_DESC_VALIDITY (24*60*60)

/** Time period within which two sets of v2 descriptors will be uploaded in
 * parallel. */
#define REND_TIME_PERIOD_OVERLAPPING_V2_DESCS (60*60)

/** Number of non-consecutive replicas (i.e. distributed somewhere
 * in the ring) for a descriptor. */
#define REND_NUMBER_OF_NON_CONSECUTIVE_REPLICAS 2

/** Number of consecutive replicas for a descriptor. */
#define REND_NUMBER_OF_CONSECUTIVE_REPLICAS 3

/** Length of v2 descriptor ID (32 base32 chars = 160 bits). */
#define REND_DESC_ID_V2_LEN_BASE32 32

/** Length of the base32-encoded secret ID part of versioned hidden service
 * descriptors. */
#define REND_SECRET_ID_PART_LEN_BASE32 32

/** Length of the base32-encoded hash of an introduction point's
 * identity key. */
#define REND_INTRO_POINT_ID_LEN_BASE32 32

/** Length of the descriptor cookie that is used for client authorization
 * to hidden services. */
#define REND_DESC_COOKIE_LEN 16

/** Length of the base64-encoded descriptor cookie that is used for
 * exchanging client authorization between hidden service and client. */
#define REND_DESC_COOKIE_LEN_BASE64 22

/** Length of client identifier in encrypted introduction points for hidden
 * service authorization type 'basic'. */
#define REND_BASIC_AUTH_CLIENT_ID_LEN 4

/** Multiple of the number of clients to which the real number of clients
 * is padded with fake clients for hidden service authorization type
 * 'basic'. */
#define REND_BASIC_AUTH_CLIENT_MULTIPLE 16

/** Length of client entry consisting of client identifier and encrypted
 * session key for hidden service authorization type 'basic'. */
#define REND_BASIC_AUTH_CLIENT_ENTRY_LEN (REND_BASIC_AUTH_CLIENT_ID_LEN \
                                          + CIPHER_KEY_LEN)

/** Maximum size of v2 hidden service descriptors. */
#define REND_DESC_MAX_SIZE (20 * 1024)

/** Legal characters for use in authorized client names for a hidden
 * service. */
#define REND_LEGAL_CLIENTNAME_CHARACTERS \
  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789+-_"

/** Maximum length of authorized client names for a hidden service. */
#define REND_CLIENTNAME_MAX_LEN 16

/** Length of the rendezvous cookie that is used to connect circuits at the
 * rendezvous point. */
#define REND_COOKIE_LEN DIGEST_LEN

/** Client authorization type that a hidden service performs. */
typedef enum rend_auth_type_t {
  REND_NO_AUTH      = 0,
  REND_BASIC_AUTH   = 1,
  REND_STEALTH_AUTH = 2,
} rend_auth_type_t;

/** Client-side configuration of authorization for a hidden service. */
typedef struct rend_service_authorization_t {
  char descriptor_cookie[REND_DESC_COOKIE_LEN];
  char onion_address[REND_SERVICE_ADDRESS_LEN+1];
  rend_auth_type_t auth_type;
} rend_service_authorization_t;

/** Client- and server-side data that is used for hidden service connection
 * establishment. Not all fields contain data depending on where this struct
 * is used. */
typedef struct rend_data_t {
  /** Onion address (without the .onion part) that a client requests. */
  char onion_address[REND_SERVICE_ID_LEN_BASE32+1];

  /** (Optional) descriptor cookie that is used by a client. */
  char descriptor_cookie[REND_DESC_COOKIE_LEN];

  /** Authorization type for accessing a service used by a client. */
  rend_auth_type_t auth_type;

  /** Hash of the hidden service's PK used by a service. */
  char rend_pk_digest[DIGEST_LEN];

  /** Rendezvous cookie used by both, client and service. */
  char rend_cookie[REND_COOKIE_LEN];
} rend_data_t;

/** Time interval for tracking replays of DH public keys received in
 * INTRODUCE2 cells.  Used only to avoid launching multiple
 * simultaneous attempts to connect to the same rendezvous point. */
#define REND_REPLAY_TIME_INTERVAL (5 * 60)

/** Used to indicate which way a cell is going on a circuit. */
typedef enum {
  CELL_DIRECTION_IN=1, /**< The cell is moving towards the origin. */
  CELL_DIRECTION_OUT=2, /**< The cell is moving away from the origin. */
} cell_direction_t;

/** Initial value for both sides of a circuit transmission window when the
 * circuit is initialized.  Measured in cells. */
#define CIRCWINDOW_START 1000
#define CIRCWINDOW_START_MIN 100
#define CIRCWINDOW_START_MAX 1000
/** Amount to increment a circuit window when we get a circuit SENDME. */
#define CIRCWINDOW_INCREMENT 100
/** Initial value on both sides of a stream transmission window when the
 * stream is initialized.  Measured in cells. */
#define STREAMWINDOW_START 500
/** Amount to increment a stream window when we get a stream SENDME. */
#define STREAMWINDOW_INCREMENT 50

/** Maximum number of queued cells on a circuit for which we are the
 * midpoint before we give up and kill it.  This must be >= circwindow
 * to avoid killing innocent circuits, and >= circwindow*2 to give
 * leaky-pipe a chance of working someday. The ORCIRC_MAX_MIDDLE_KILL_THRESH
 * ratio controls the margin of error between emitting a warning and
 * killing the circuit.
 */
#define ORCIRC_MAX_MIDDLE_CELLS (CIRCWINDOW_START_MAX*2)
/** Ratio of hard (circuit kill) to soft (warning) thresholds for the
 * ORCIRC_MAX_MIDDLE_CELLS tests.
 */
#define ORCIRC_MAX_MIDDLE_KILL_THRESH (1.1f)

/* Cell commands.  These values are defined in tor-spec.txt. */
#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
#define CELL_VERSIONS 7
#define CELL_NETINFO 8
#define CELL_RELAY_EARLY 9
#define CELL_CREATE2 10
#define CELL_CREATED2 11

#define CELL_VPADDING 128
#define CELL_CERTS 129
#define CELL_AUTH_CHALLENGE 130
#define CELL_AUTHENTICATE 131
#define CELL_AUTHORIZE 132
#define CELL_COMMAND_MAX_ 132

/** How long to test reachability before complaining to the user. */
#define TIMEOUT_UNTIL_UNREACHABILITY_COMPLAINT (20*60)

/** Legal characters in a nickname. */
#define LEGAL_NICKNAME_CHARACTERS \
  "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"

/** Name to use in client TLS certificates if no nickname is given. Once
 * Tor 0.1.2.x is obsolete, we can remove this. */
#define DEFAULT_CLIENT_NICKNAME "client"

/** Name chosen by routers that don't configure nicknames */
#define UNNAMED_ROUTER_NICKNAME "Unnamed"

/** Number of bytes in a SOCKS4 header. */
#define SOCKS4_NETWORK_LEN 8

/*
 * 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]
 */

/** Number of bytes in a cell, minus cell header. */
#define CELL_PAYLOAD_SIZE 509
/** Number of bytes in a cell transmitted over the network, in the longest
 * form */
#define CELL_MAX_NETWORK_SIZE 514

/** Maximum length of a header on a variable-length cell. */
#define VAR_CELL_MAX_HEADER_SIZE 7

static int get_cell_network_size(int wide_circ_ids);
static INLINE int get_cell_network_size(int wide_circ_ids)
{
  return wide_circ_ids ? CELL_MAX_NETWORK_SIZE : CELL_MAX_NETWORK_SIZE - 2;
}
static int get_var_cell_header_size(int wide_circ_ids);
static INLINE int get_var_cell_header_size(int wide_circ_ids)
{
  return wide_circ_ids ? VAR_CELL_MAX_HEADER_SIZE :
    VAR_CELL_MAX_HEADER_SIZE - 2;
}
static int get_circ_id_size(int wide_circ_ids);
static INLINE int get_circ_id_size(int wide_circ_ids)
{
  return wide_circ_ids ? 4 : 2;
}

/** Number of bytes in a relay cell's header (not including general cell
 * header). */
#define RELAY_HEADER_SIZE (1+2+2+4+2)
/** Largest number of bytes that can fit in a relay cell payload. */
#define RELAY_PAYLOAD_SIZE (CELL_PAYLOAD_SIZE-RELAY_HEADER_SIZE)

/** Identifies a circuit on an or_connection */
typedef uint32_t circid_t;
/** Identifies a stream on a circuit */
typedef uint16_t streamid_t;

/* channel_t typedef; struct channel_s is in channel.h */

typedef struct channel_s channel_t;

/* channel_listener_t typedef; struct channel_listener_s is in channel.h */

typedef struct channel_listener_s channel_listener_t;

/* channel states for channel_t */

typedef enum {
  /*
   * Closed state - channel is inactive
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_CLOSING
   * Permitted transitions to:
   *   - CHANNEL_STATE_OPENING
   */
  CHANNEL_STATE_CLOSED = 0,
  /*
   * Opening state - channel is trying to connect
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_CLOSED
   * Permitted transitions to:
   *   - CHANNEL_STATE_CLOSING
   *   - CHANNEL_STATE_ERROR
   *   - CHANNEL_STATE_OPEN
   */
  CHANNEL_STATE_OPENING,
  /*
   * Open state - channel is active and ready for use
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_MAINT
   *   - CHANNEL_STATE_OPENING
   * Permitted transitions to:
   *   - CHANNEL_STATE_CLOSING
   *   - CHANNEL_STATE_ERROR
   *   - CHANNEL_STATE_MAINT
   */
  CHANNEL_STATE_OPEN,
  /*
   * Maintenance state - channel is temporarily offline for subclass specific
   *   maintenance activities such as TLS renegotiation.
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_OPEN
   * Permitted transitions to:
   *   - CHANNEL_STATE_CLOSING
   *   - CHANNEL_STATE_ERROR
   *   - CHANNEL_STATE_OPEN
   */
  CHANNEL_STATE_MAINT,
  /*
   * Closing state - channel is shutting down
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_MAINT
   *   - CHANNEL_STATE_OPEN
   * Permitted transitions to:
   *   - CHANNEL_STATE_CLOSED,
   *   - CHANNEL_STATE_ERROR
   */
  CHANNEL_STATE_CLOSING,
  /*
   * Error state - channel has experienced a permanent error
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_CLOSING
   *   - CHANNEL_STATE_MAINT
   *   - CHANNEL_STATE_OPENING
   *   - CHANNEL_STATE_OPEN
   * Permitted transitions to:
   *   - None
   */
  CHANNEL_STATE_ERROR,
  /*
   * Placeholder for maximum state value
   */
  CHANNEL_STATE_LAST
} channel_state_t;

/* channel listener states for channel_listener_t */

typedef enum {
  /*
   * Closed state - channel listener is inactive
   *
   * Permitted transitions from:
   *   - CHANNEL_LISTENER_STATE_CLOSING
   * Permitted transitions to:
   *   - CHANNEL_LISTENER_STATE_LISTENING
   */
  CHANNEL_LISTENER_STATE_CLOSED = 0,
  /*
   * Listening state - channel listener is listening for incoming
   * connections
   *
   * Permitted transitions from:
   *   - CHANNEL_LISTENER_STATE_CLOSED
   * Permitted transitions to:
   *   - CHANNEL_LISTENER_STATE_CLOSING
   *   - CHANNEL_LISTENER_STATE_ERROR
   */
  CHANNEL_LISTENER_STATE_LISTENING,
  /*
   * Closing state - channel listener is shutting down
   *
   * Permitted transitions from:
   *   - CHANNEL_LISTENER_STATE_LISTENING
   * Permitted transitions to:
   *   - CHANNEL_LISTENER_STATE_CLOSED,
   *   - CHANNEL_LISTENER_STATE_ERROR
   */
  CHANNEL_LISTENER_STATE_CLOSING,
  /*
   * Error state - channel listener has experienced a permanent error
   *
   * Permitted transitions from:
   *   - CHANNEL_STATE_CLOSING
   *   - CHANNEL_STATE_LISTENING
   * Permitted transitions to:
   *   - None
   */
  CHANNEL_LISTENER_STATE_ERROR,
  /*
   * Placeholder for maximum state value
   */
  CHANNEL_LISTENER_STATE_LAST
} channel_listener_state_t;

/* TLS channel stuff */

typedef struct channel_tls_s channel_tls_t;

/* circuitmux_t typedef; struct circuitmux_s is in circuitmux.h */

typedef struct circuitmux_s circuitmux_t;

/** Parsed onion routing cell.  All communication between nodes
 * is via cells. */
typedef struct cell_t {
  circid_t circ_id; /**< Circuit which received the cell. */
  uint8_t command; /**< Type of the cell: one of CELL_PADDING, CELL_CREATE,
                    * CELL_DESTROY, etc */
  uint8_t payload[CELL_PAYLOAD_SIZE]; /**< Cell body. */
} cell_t;

/** Parsed variable-length onion routing cell. */
typedef struct var_cell_t {
  /** Type of the cell: CELL_VERSIONS, etc. */
  uint8_t command;
  /** Circuit thich received the cell */
  circid_t circ_id;
  /** Number of bytes actually stored in <b>payload</b> */
  uint16_t payload_len;
  /** Payload of this cell */
  uint8_t payload[FLEXIBLE_ARRAY_MEMBER];
} var_cell_t;

/** A parsed Extended ORPort message. */
typedef struct ext_or_cmd_t {
  uint16_t cmd; /** Command type */
  uint16_t len; /** Body length */
  char body[FLEXIBLE_ARRAY_MEMBER]; /** Message body */
} ext_or_cmd_t;

/** A cell as packed for writing to the network. */
typedef struct packed_cell_t {
  /** Next cell queued on this circuit. */
  TOR_SIMPLEQ_ENTRY(packed_cell_t) next;
  char body[CELL_MAX_NETWORK_SIZE]; /**< Cell as packed for network. */
  uint32_t inserted_time; /**< Time (in milliseconds since epoch, with high
                           * bits truncated) when this cell was inserted. */
} packed_cell_t;

/** A queue of cells on a circuit, waiting to be added to the
 * or_connection_t's outbuf. */
typedef struct cell_queue_t {
  /** Linked list of packed_cell_t*/
  TOR_SIMPLEQ_HEAD(cell_simpleq, packed_cell_t) head;
  int n; /**< The number of cells in the queue. */
} cell_queue_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. */
  streamid_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;
#ifdef USE_BUFFEREVENTS
#define generic_buffer_t struct evbuffer
#else
#define generic_buffer_t buf_t
#endif

/* Values for connection_t.magic: used to make sure that downcasts (casts from
* connection_t to foo_connection_t) are safe. */
#define BASE_CONNECTION_MAGIC 0x7C3C304Eu
#define OR_CONNECTION_MAGIC 0x7D31FF03u
#define EDGE_CONNECTION_MAGIC 0xF0374013u
#define ENTRY_CONNECTION_MAGIC 0xbb4a5703
#define DIR_CONNECTION_MAGIC 0x9988ffeeu
#define CONTROL_CONNECTION_MAGIC 0x8abc765du
#define LISTENER_CONNECTION_MAGIC 0x1a1ac741u

/** 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 a Tor node 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.
 */
typedef struct connection_t {
  uint32_t magic; /**< For memory debugging: must equal one of
                   * *_CONNECTION_MAGIC. */

  uint8_t state; /**< Current state of this connection. */
  unsigned int type:5; /**< What kind of connection is this? */
  unsigned int purpose:5; /**< Only used for DIR and EXIT types currently. */

  /* The next fields are all one-bit booleans. Some are only applicable to
   * connection subtypes, but we hold them here anyway, to save space.
   */
  unsigned int read_blocked_on_bw:1; /**< Boolean: should we start reading
                            * again once the bandwidth throttler allows it? */
  unsigned int write_blocked_on_bw:1; /**< Boolean: should we start writing
                             * again once the bandwidth throttler allows
                             * writes? */
  unsigned int hold_open_until_flushed:1; /**< Despite this connection's being
                                      * marked for close, do we flush it
                                      * before closing it? */
  unsigned int inbuf_reached_eof:1; /**< Boolean: did read() return 0 on this
                                     * conn? */
  /** Set to 1 when we're inside connection_flushed_some to keep us from
   * calling connection_handle_write() recursively. */
  unsigned int in_flushed_some:1;
  /** True if connection_handle_write is currently running on this connection.
   */
  unsigned int in_connection_handle_write:1;

  /* For linked connections:
   */
  unsigned int linked:1; /**< True if there is, or has been, a linked_conn. */
  /** True iff we'd like to be notified about read events from the
   * linked conn. */
  unsigned int reading_from_linked_conn:1;
  /** True iff we're willing to write to the linked conn. */
  unsigned int writing_to_linked_conn:1;
  /** True iff we're currently able to read on the linked conn, and our
   * read_event should be made active with libevent. */
  unsigned int active_on_link:1;
  /** True iff we've called connection_close_immediate() on this linked
   * connection. */
  unsigned int linked_conn_is_closed:1;

  /** CONNECT/SOCKS proxy client handshake state (for outgoing connections). */
  unsigned int proxy_state:4;

  /** Our socket; set to TOR_INVALID_SOCKET if this connection is closed,
   * or has no socket. */
  tor_socket_t s;
  int conn_array_index; /**< Index into the global connection array. */

  struct event *read_event; /**< Libevent event structure. */
  struct event *write_event; /**< Libevent event structure. */
  buf_t *inbuf; /**< Buffer holding data read over this connection. */
  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_lastread; /**< When was the last time libevent said we could
                              * read? */
  time_t timestamp_lastwritten; /**< When was the last time libevent said we
                                 * could write? */

#ifdef USE_BUFFEREVENTS
  struct bufferevent *bufev; /**< A Libevent buffered IO structure. */
#endif

  time_t timestamp_created; /**< When was this connection_t created? */

  /* XXXX_IP6 make this IPv6-capable */
  int socket_family; /**< Address family of this connection's socket.  Usually
                      * AF_INET, but it can also be AF_UNIX, or in the future
                      * AF_INET6 */
  tor_addr_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. */
  uint16_t 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? */
  char *address; /**< FQDN (or IP) of the guy on the other end.
                  * strdup into this, because free_connection() frees it. */
  /** Another connection that's connected to this one in lieu of a socket. */
  struct connection_t *linked_conn;

  /** Unique identifier for this connection on this Tor instance. */
  uint64_t global_identifier;

  /** Bytes read since last call to control_event_conn_bandwidth_used().
   * Only used if we're configured to emit CONN_BW events. */
  uint32_t n_read_conn_bw;

  /** Bytes written since last call to control_event_conn_bandwidth_used().
   * Only used if we're configured to emit CONN_BW events. */
  uint32_t n_written_conn_bw;
} connection_t;

/** Subtype of connection_t; used for a listener socket. */
typedef struct listener_connection_t {
  connection_t base_;

  /** If the connection is a CONN_TYPE_AP_DNS_LISTENER, this field points
   * to the evdns_server_port it uses to listen to and answer connections. */
  struct evdns_server_port *dns_server_port;

  /** @name Isolation parameters
   *
   * For an AP listener, these fields describe how to isolate streams that
   * arrive on the listener.
   *
   * @{
   */
  /** The session group for this listener. */
  int session_group;
  /** One or more ISO_ flags to describe how to isolate streams. */
  uint8_t isolation_flags;
  /**@}*/
  /** For SOCKS connections only: If this is set, we will choose "no
   * authentication" instead of "username/password" authentication if both
   * are offered. Used as input to parse_socks. */
  unsigned int socks_prefer_no_auth : 1;

  /** For a SOCKS listeners, these fields describe whether we should
   * allow IPv4 and IPv6 addresses from our exit nodes, respectively.
   *
   * @{
   */
  unsigned int socks_ipv4_traffic : 1;
  unsigned int socks_ipv6_traffic : 1;
  /** @} */
  /** For a socks listener: should we tell the exit that we prefer IPv6
   * addresses? */
  unsigned int socks_prefer_ipv6 : 1;

  /** For a socks listener: should we cache IPv4/IPv6 DNS information that
   * exit nodes tell us?
   *
   * @{ */
  unsigned int cache_ipv4_answers : 1;
  unsigned int cache_ipv6_answers : 1;
  /** @} */
  /** For a socks listeners: if we find an answer in our client-side DNS cache,
   * should we use it?
   *
   * @{ */
  unsigned int use_cached_ipv4_answers : 1;
  unsigned int use_cached_ipv6_answers : 1;
  /** @} */
  /** For socks listeners: When we can automap an address to IPv4 or IPv6,
   * do we prefer IPv6? */
  unsigned int prefer_ipv6_virtaddr : 1;

} listener_connection_t;

/** Minimum length of the random part of an AUTH_CHALLENGE cell. */
#define OR_AUTH_CHALLENGE_LEN 32

/**
 * @name Certificate types for CERTS cells.
 *
 * These values are defined by the protocol, and affect how an X509
 * certificate in a CERTS cell is interpreted and used.
 *
 * @{ */
/** A certificate that authenticates a TLS link key.  The subject key
 * must match the key used in the TLS handshake; it must be signed by
 * the identity key. */
#define OR_CERT_TYPE_TLS_LINK 1
/** A self-signed identity certificate. The subject key must be a
 * 1024-bit RSA key. */
#define OR_CERT_TYPE_ID_1024 2
/** A certificate that authenticates a key used in an AUTHENTICATE cell
 * in the v3 handshake.  The subject key must be a 1024-bit RSA key; it
 * must be signed by the identity key */
#define OR_CERT_TYPE_AUTH_1024 3
/**@}*/

/** The one currently supported type of AUTHENTICATE cell.  It contains
 * a bunch of structures signed with an RSA1024 key.  The signed
 * structures include a HMAC using negotiated TLS secrets, and a digest
 * of all cells sent or received before the AUTHENTICATE cell (including
 * the random server-generated AUTH_CHALLENGE cell).
 */
#define AUTHTYPE_RSA_SHA256_TLSSECRET 1

/** The length of the part of the AUTHENTICATE cell body that the client and
 * server can generate independently (when using RSA_SHA256_TLSSECRET). It
 * contains everything except the client's timestamp, the client's randomly
 * generated nonce, and the signature. */
#define V3_AUTH_FIXED_PART_LEN (8+(32*6))
/** The length of the part of the AUTHENTICATE cell body that the client
 * signs. */
#define V3_AUTH_BODY_LEN (V3_AUTH_FIXED_PART_LEN + 8 + 16)

/** Stores flags and information related to the portion of a v2/v3 Tor OR
 * connection handshake that happens after the TLS handshake is finished.
 */
typedef struct or_handshake_state_t {
  /** When was the VERSIONS cell sent on this connection?  Used to get
   * an estimate of the skew in the returning NETINFO reply. */
  time_t sent_versions_at;
  /** True iff we originated this connection */
  unsigned int started_here : 1;
  /** True iff we have received and processed a VERSIONS cell. */
  unsigned int received_versions : 1;
  /** True iff we have received and processed an AUTH_CHALLENGE cell */
  unsigned int received_auth_challenge : 1;
  /** True iff we have received and processed a CERTS cell. */
  unsigned int received_certs_cell : 1;
  /** True iff we have received and processed an AUTHENTICATE cell */
  unsigned int received_authenticate : 1;

  /* True iff we've received valid authentication to some identity. */
  unsigned int authenticated : 1;

  /* True iff we have sent a netinfo cell */
  unsigned int sent_netinfo : 1;

  /** True iff we should feed outgoing cells into digest_sent and
   * digest_received respectively.
   *
   * From the server's side of the v3 handshake, we want to capture everything
   * from the VERSIONS cell through and including the AUTH_CHALLENGE cell.
   * From the client's, we want to capture everything from the VERSIONS cell
   * through but *not* including the AUTHENTICATE cell.
   *
   * @{ */
  unsigned int digest_sent_data : 1;
  unsigned int digest_received_data : 1;
  /**@}*/

  /** Identity digest that we have received and authenticated for our peer
   * on this connection. */
  uint8_t authenticated_peer_id[DIGEST_LEN];

  /** Digests of the cells that we have sent or received as part of a V3
   * handshake.  Used for making and checking AUTHENTICATE cells.
   *
   * @{
   */
  crypto_digest_t *digest_sent;
  crypto_digest_t *digest_received;
  /** @} */

  /** Certificates that a connection initiator sent us in a CERTS cell; we're
   * holding on to them until we get an AUTHENTICATE cell.
   *
   * @{
   */
  /** The cert for the key that's supposed to sign the AUTHENTICATE cell */
  tor_cert_t *auth_cert;
  /** A self-signed identity certificate */
  tor_cert_t *id_cert;
  /**@}*/
} or_handshake_state_t;

/** Length of Extended ORPort connection identifier. */
#define EXT_OR_CONN_ID_LEN DIGEST_LEN /* 20 */

/** Subtype of connection_t for an "OR connection" -- that is, one that speaks
 * cells over TLS. */
typedef struct or_connection_t {
  connection_t base_;

  /** Hash of the public RSA key for the other side's identity key, or zeroes
   * if the other side hasn't shown us a valid identity key. */
  char identity_digest[DIGEST_LEN];

  /** Extended ORPort connection identifier. */
  char *ext_or_conn_id;
  /** This is the ClientHash value we expect to receive from the
   *  client during the Extended ORPort authentication protocol. We
   *  compute it upon receiving the ClientNoce from the client, and we
   *  compare it with the acual ClientHash value sent by the
   *  client. */
  char *ext_or_auth_correct_client_hash;
  /** String carrying the name of the pluggable transport
   *  (e.g. "obfs2") that is obfuscating this connection. If no
   *  pluggable transports are used, it's NULL. */
  char *ext_or_transport;

  char *nickname; /**< Nickname of OR on other side (if any). */

  tor_tls_t *tls; /**< TLS connection state. */
  int tls_error; /**< Last tor_tls error code. */
  /** When we last used this conn for any client traffic. If not
   * recent, we can rate limit it further. */

  /* Channel using this connection */
  channel_tls_t *chan;

  tor_addr_t real_addr; /**< The actual address that this connection came from
                       * or went to.  The <b>addr</b> field is prone to
                       * getting overridden by the address from the router
                       * descriptor matching <b>identity_digest</b>. */

  /** Should this connection be used for extending circuits to the server
   * matching the <b>identity_digest</b> field?  Set to true if we're pretty
   * sure we aren't getting MITMed, either because we're connected to an
   * address listed in a server descriptor, or because an authenticated
   * NETINFO cell listed the address we're connected to as recognized. */
  unsigned int is_canonical:1;

  /** True iff we have decided that the other end of this connection
   * is a client.  Connections with this flag set should never be used
   * to satisfy an EXTEND request.  */
  unsigned int is_connection_with_client:1;
  /** True iff this is an outgoing connection. */
  unsigned int is_outgoing:1;
  unsigned int proxy_type:2; /**< One of PROXY_NONE...PROXY_SOCKS5 */
  unsigned int wide_circ_ids:1;
  /** True iff this connection has had its bootstrap failure logged with
   * control_event_bootstrap_problem. */
  unsigned int have_noted_bootstrap_problem:1;

  uint16_t link_proto; /**< What protocol version are we using? 0 for
                        * "none negotiated yet." */

  or_handshake_state_t *handshake_state; /**< If we are setting this connection
                                          * up, state information to do so. */

  time_t timestamp_lastempty; /**< When was the outbuf last completely empty?*/
  time_t timestamp_last_added_nonpadding; /** When did we last add a
                                           * non-padding cell to the outbuf? */

  /* bandwidth* and *_bucket only used by ORs in OPEN state: */
  int bandwidthrate; /**< Bytes/s added to the bucket. (OPEN ORs only.) */
  int bandwidthburst; /**< Max bucket size for this conn. (OPEN ORs only.) */
#ifndef USE_BUFFEREVENTS
  int read_bucket; /**< When this hits 0, stop receiving. Every second we
                    * add 'bandwidthrate' to this, capping it at
                    * bandwidthburst. (OPEN ORs only) */
  int write_bucket; /**< When this hits 0, stop writing. Like read_bucket. */
#else
  /** A rate-limiting configuration object to determine how this connection
   * set its read- and write- limits. */
  /* XXXX we could share this among all connections. */
  struct ev_token_bucket_cfg *bucket_cfg;
#endif

  struct or_connection_t *next_with_same_id; /**< Next connection with same
                                              * identity digest as this one. */
  /** Last emptied read token bucket in msec since midnight; only used if
   * TB_EMPTY events are enabled. */
  uint32_t read_emptied_time;
  /** Last emptied write token bucket in msec since midnight; only used if
   * TB_EMPTY events are enabled. */
  uint32_t write_emptied_time;
} or_connection_t;

/** Subtype of connection_t for an "edge connection" -- that is, an entry (ap)
 * connection, or an exit. */
typedef struct edge_connection_t {
  connection_t base_;

  struct edge_connection_t *next_stream; /**< Points to the next stream at this
                                          * edge, if any */
  int package_window; /**< How many more relay cells can I send into the
                       * circuit? */
  int deliver_window; /**< How many more relay cells can end at me? */

  struct circuit_t *on_circuit; /**< The circuit (if any) that this edge
                                 * connection is using. */

  /** A pointer to which node in the circ this conn exits at.  Set for AP
   * connections and for hidden service exit connections. */
  struct crypt_path_t *cpath_layer;
  /** What rendezvous service are we querying for (if an AP) or providing (if
   * an exit)? */
  rend_data_t *rend_data;

  uint32_t address_ttl; /**< TTL for address-to-addr mapping on exit
                         * connection.  Exit connections only. */
  uint32_t begincell_flags; /** Flags sent or received in the BEGIN cell
                             * for this connection */

  streamid_t stream_id; /**< The stream ID used for this edge connection on its
                         * circuit */

  /** The reason why this connection is closing; passed to the controller. */
  uint16_t end_reason;

  /** Bytes read since last call to control_event_stream_bandwidth_used() */
  uint32_t n_read;

  /** Bytes written since last call to control_event_stream_bandwidth_used() */
  uint32_t n_written;

  /** True iff this connection is for a DNS request only. */
  unsigned int is_dns_request:1;
  /** True iff this connection is for a PTR DNS request. (exit only) */
  unsigned int is_reverse_dns_lookup:1;

  unsigned int edge_has_sent_end:1; /**< For debugging; only used on edge
                         * connections.  Set once we've set the stream end,
                         * and check in connection_about_to_close_connection().
                         */
  /** True iff we've blocked reading until the circuit has fewer queued
   * cells. */
  unsigned int edge_blocked_on_circ:1;

  /** Unique ID for directory requests; this used to be in connection_t, but
   * that's going away and being used on channels instead.  We still tag
   * edge connections with dirreq_id from circuits, so it's copied here. */
  uint64_t dirreq_id;
} edge_connection_t;

/** Subtype of edge_connection_t for an "entry connection" -- that is, a SOCKS
 * connection, a DNS request, a TransPort connection or a NATD connection */
typedef struct entry_connection_t {
  edge_connection_t edge_;

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

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

  /* === Isolation related, AP only. === */
  /** AP only: based on which factors do we isolate this stream? */
  uint8_t isolation_flags;
  /** AP only: what session group is this stream in? */
  int session_group;
  /** AP only: The newnym epoch in which we created this connection. */
  unsigned nym_epoch;
  /** AP only: The original requested address before we rewrote it. */
  char *original_dest_address;
  /* Other fields to isolate on already exist.  The ClientAddr is addr.  The
     ClientProtocol is a combination of type and socks_request->
     socks_version.  SocksAuth is socks_request->username/password.
     DestAddr is in socks_request->address. */

  /** Number of times we've reassigned this application connection to
   * a new circuit. We keep track because the timeout is longer if we've
   * already retried several times. */
  uint8_t num_socks_retries;

  /** For AP connections only: buffer for data that we have sent
   * optimistically, which we might need to re-send if we have to
   * retry this connection. */
  generic_buffer_t *pending_optimistic_data;
  /* For AP connections only: buffer for data that we previously sent
  * optimistically which we are currently re-sending as we retry this
  * connection. */
  generic_buffer_t *sending_optimistic_data;

  /** If this is a DNSPort connection, this field holds the pending DNS
   * request that we're going to try to answer.  */
  struct evdns_server_request *dns_server_request;

#define NUM_CIRCUITS_LAUNCHED_THRESHOLD 10
  /** Number of times we've launched a circuit to handle this stream. If
    * it gets too high, that could indicate an inconsistency between our
    * "launch a circuit to handle this stream" logic and our "attach our
    * stream to one of the available circuits" logic. */
  unsigned int num_circuits_launched:4;

  /** True iff this stream must attach to a one-hop circuit (e.g. for
   * begin_dir). */
  unsigned int want_onehop:1;
  /** True iff this stream should use a BEGIN_DIR relay command to establish
   * itself rather than BEGIN (either via onehop or via a whole circuit). */
  unsigned int use_begindir:1;

  /** For AP connections only. If 1, and we fail to reach the chosen exit,
   * stop requiring it. */
  unsigned int chosen_exit_optional:1;
  /** For AP connections only. If non-zero, this exit node was picked as
   * a result of the TrackHostExit, and the value decrements every time
   * we fail to complete a circuit to our chosen exit -- if it reaches
   * zero, abandon the associated mapaddress. */
  unsigned int chosen_exit_retries:3;

  /** True iff this is an AP connection that came from a transparent or
   * NATd connection */
  unsigned int is_transparent_ap:1;

  /** For AP connections only: Set if this connection's target exit node
   * allows optimistic data (that is, data sent on this stream before
   * the exit has sent a CONNECTED cell) and we have chosen to use it.
   */
  unsigned int may_use_optimistic_data : 1;

  /** Should we permit IPv4 and IPv6 traffic to use this connection?
   *
   * @{ */
  unsigned int ipv4_traffic_ok : 1;
  unsigned int ipv6_traffic_ok : 1;
  /** @} */
  /** Should we say we prefer IPv6 traffic? */
  unsigned int prefer_ipv6_traffic : 1;

  /** For a socks listener: should we cache IPv4/IPv6 DNS information that
   * exit nodes tell us?
   *
   * @{ */
  unsigned int cache_ipv4_answers : 1;
  unsigned int cache_ipv6_answers : 1;
  /** @} */
  /** For a socks listeners: if we find an answer in our client-side DNS cache,
   * should we use it?
   *
   * @{ */
  unsigned int use_cached_ipv4_answers : 1;
  unsigned int use_cached_ipv6_answers : 1;
  /** @} */
  /** For socks listeners: When we can automap an address to IPv4 or IPv6,
   * do we prefer IPv6? */
  unsigned int prefer_ipv6_virtaddr : 1;

} entry_connection_t;

typedef enum {
    DIR_SPOOL_NONE=0, DIR_SPOOL_SERVER_BY_DIGEST, DIR_SPOOL_SERVER_BY_FP,
    DIR_SPOOL_EXTRA_BY_DIGEST, DIR_SPOOL_EXTRA_BY_FP,
    DIR_SPOOL_CACHED_DIR, DIR_SPOOL_NETWORKSTATUS,
    DIR_SPOOL_MICRODESC, /* NOTE: if we add another entry, add another bit. */
} dir_spool_source_t;
#define dir_spool_source_bitfield_t ENUM_BF(dir_spool_source_t)

/** Subtype of connection_t for an "directory connection" -- that is, an HTTP
 * connection to retrieve or serve directory material. */
typedef struct dir_connection_t {
  connection_t base_;

 /** Which 'resource' did we ask the directory for? This is typically the part
  * of the URL string that defines, relative to the directory conn purpose,
  * what thing we want.  For example, in router descriptor downloads by
  * descriptor digest, it contains "d/", then one ore more +-separated
  * fingerprints.
  **/
  char *requested_resource;
  unsigned int dirconn_direct:1; /**< Is this dirconn direct, or via Tor? */

  /* Used only for server sides of some dir connections, to implement
   * "spooling" of directory material to the outbuf.  Otherwise, we'd have
   * to append everything to the outbuf in one enormous chunk. */
  /** What exactly are we spooling right now? */
  dir_spool_source_bitfield_t  dir_spool_src : 3;

  /** If we're fetching descriptors, what router purpose shall we assign
   * to them? */
  uint8_t router_purpose;
  /** List of fingerprints for networkstatuses or descriptors to be spooled. */
  smartlist_t *fingerprint_stack;
  /** A cached_dir_t object that we're currently spooling out */
  struct cached_dir_t *cached_dir;
  /** The current offset into cached_dir. */
  off_t cached_dir_offset;
  /** The zlib object doing on-the-fly compression for spooled data. */
  tor_zlib_state_t *zlib_state;

  /** What rendezvous service are we querying for? */
  rend_data_t *rend_data;

  char identity_digest[DIGEST_LEN]; /**< Hash of the public RSA key for
                                     * the directory server's signing key. */

  /** Unique ID for directory requests; this used to be in connection_t, but
   * that's going away and being used on channels instead.  The dirserver still
   * needs this for the incoming side, so it's moved here. */
  uint64_t dirreq_id;
} dir_connection_t;

/** Subtype of connection_t for an connection to a controller. */
typedef struct control_connection_t {
  connection_t base_;

  uint32_t event_mask; /**< Bitfield: which events does this controller
                        * care about? */

  /** True if we have sent a protocolinfo reply on this connection. */
  unsigned int have_sent_protocolinfo:1;
  /** True if we have received a takeownership command on this
   * connection. */
  unsigned int is_owning_control_connection:1;

  /** If we have sent an AUTHCHALLENGE reply on this connection and
   * have not received a successful AUTHENTICATE command, points to
   * the value which the client must send to authenticate itself;
   * otherwise, NULL. */
  char *safecookie_client_hash;

  /** Amount of space allocated in incoming_cmd. */
  uint32_t incoming_cmd_len;
  /** Number of bytes currently stored in incoming_cmd. */
  uint32_t incoming_cmd_cur_len;
  /** A control command that we're reading from the inbuf, but which has not
   * yet arrived completely. */
  char *incoming_cmd;
} control_connection_t;

/** Cast a connection_t subtype pointer to a connection_t **/
#define TO_CONN(c) (&(((c)->base_)))
/** Helper macro: Given a pointer to to.base_, of type from*, return &to. */
#define DOWNCAST(to, ptr) ((to*)SUBTYPE_P(ptr, to, base_))

/** Cast a entry_connection_t subtype pointer to a edge_connection_t **/
#define ENTRY_TO_EDGE_CONN(c) (&(((c))->edge_))
/** Cast a entry_connection_t subtype pointer to a connection_t **/
#define ENTRY_TO_CONN(c) (TO_CONN(ENTRY_TO_EDGE_CONN(c)))

/** Convert a connection_t* to an or_connection_t*; assert if the cast is
 * invalid. */
static or_connection_t *TO_OR_CONN(connection_t *);
/** Convert a connection_t* to a dir_connection_t*; assert if the cast is
 * invalid. */
static dir_connection_t *TO_DIR_CONN(connection_t *);
/** Convert a connection_t* to an edge_connection_t*; assert if the cast is
 * invalid. */
static edge_connection_t *TO_EDGE_CONN(connection_t *);
/** Convert a connection_t* to an entry_connection_t*; assert if the cast is
 * invalid. */
static entry_connection_t *TO_ENTRY_CONN(connection_t *);
/** Convert a edge_connection_t* to an entry_connection_t*; assert if the cast
 * is invalid. */
static entry_connection_t *EDGE_TO_ENTRY_CONN(edge_connection_t *);
/** Convert a connection_t* to an control_connection_t*; assert if the cast is
 * invalid. */
static control_connection_t *TO_CONTROL_CONN(connection_t *);
/** Convert a connection_t* to an listener_connection_t*; assert if the cast is
 * invalid. */
static listener_connection_t *TO_LISTENER_CONN(connection_t *);

static INLINE or_connection_t *TO_OR_CONN(connection_t *c)
{
  tor_assert(c->magic == OR_CONNECTION_MAGIC);
  return DOWNCAST(or_connection_t, c);
}
static INLINE dir_connection_t *TO_DIR_CONN(connection_t *c)
{
  tor_assert(c->magic == DIR_CONNECTION_MAGIC);
  return DOWNCAST(dir_connection_t, c);
}
static INLINE edge_connection_t *TO_EDGE_CONN(connection_t *c)
{
  tor_assert(c->magic == EDGE_CONNECTION_MAGIC ||
             c->magic == ENTRY_CONNECTION_MAGIC);
  return DOWNCAST(edge_connection_t, c);
}
static INLINE entry_connection_t *TO_ENTRY_CONN(connection_t *c)
{
  tor_assert(c->magic == ENTRY_CONNECTION_MAGIC);
  return (entry_connection_t*) SUBTYPE_P(c, entry_connection_t, edge_.base_);
}
static INLINE entry_connection_t *EDGE_TO_ENTRY_CONN(edge_connection_t *c)
{
  tor_assert(c->base_.magic == ENTRY_CONNECTION_MAGIC);
  return (entry_connection_t*) SUBTYPE_P(c, entry_connection_t, edge_);
}
static INLINE control_connection_t *TO_CONTROL_CONN(connection_t *c)
{
  tor_assert(c->magic == CONTROL_CONNECTION_MAGIC);
  return DOWNCAST(control_connection_t, c);
}
static INLINE listener_connection_t *TO_LISTENER_CONN(connection_t *c)
{
  tor_assert(c->magic == LISTENER_CONNECTION_MAGIC);
  return DOWNCAST(listener_connection_t, c);
}

/* Conditional macros to help write code that works whether bufferevents are
   disabled or not.

   We can't just write:
      if (conn->bufev) {
        do bufferevent stuff;
      } else {
        do other stuff;
      }
   because the bufferevent stuff won't even compile unless we have a fairly
   new version of Libevent.  Instead, we say:
      IF_HAS_BUFFEREVENT(conn, { do_bufferevent_stuff } );
   or:
      IF_HAS_BUFFEREVENT(conn, {
        do bufferevent stuff;
      }) ELSE_IF_NO_BUFFEREVENT {
        do non-bufferevent stuff;
      }
   If we're compiling with bufferevent support, then the macros expand more or
   less to:
      if (conn->bufev) {
        do_bufferevent_stuff;
      } else {
        do non-bufferevent stuff;
      }
   and if we aren't using bufferevents, they expand more or less to:
      { do non-bufferevent stuff; }
*/
#ifdef USE_BUFFEREVENTS
#define HAS_BUFFEREVENT(c) (((c)->bufev) != NULL)
#define IF_HAS_BUFFEREVENT(c, stmt)                \
  if ((c)->bufev) do {                             \
      stmt ;                                       \
  } while (0)
#define ELSE_IF_NO_BUFFEREVENT ; else
#define IF_HAS_NO_BUFFEREVENT(c)                   \
  if (NULL == (c)->bufev)
#else
#define HAS_BUFFEREVENT(c) (0)
#define IF_HAS_BUFFEREVENT(c, stmt) (void)0
#define ELSE_IF_NO_BUFFEREVENT ;
#define IF_HAS_NO_BUFFEREVENT(c)                \
  if (1)
#endif

/** What action type does an address policy indicate: accept or reject? */
typedef enum {
  ADDR_POLICY_ACCEPT=1,
  ADDR_POLICY_REJECT=2,
} addr_policy_action_t;
#define addr_policy_action_bitfield_t ENUM_BF(addr_policy_action_t)

/** A reference-counted address policy rule. */
typedef struct addr_policy_t {
  int refcnt; /**< Reference count */
  /** What to do when the policy matches.*/
  addr_policy_action_bitfield_t policy_type:2;
  unsigned int is_private:1; /**< True iff this is the pseudo-address,
                              * "private". */
  unsigned int is_canonical:1; /**< True iff this policy is the canonical
                                * copy (stored in a hash table to avoid
                                * duplication of common policies) */
  maskbits_t maskbits; /**< Accept/reject all addresses <b>a</b> such that the
                 * first <b>maskbits</b> bits of <b>a</b> match
                 * <b>addr</b>. */
  /** Base address to accept or reject.
   *
   * Note that wildcards are treated
   * differntly depending on address family. An AF_UNSPEC address means
   * "All addresses, IPv4 or IPv6." An AF_INET address with maskbits==0 means
   * "All IPv4 addresses" and an AF_INET6 address with maskbits == 0 means
   * "All IPv6 addresses".
  **/
  tor_addr_t addr;
  uint16_t prt_min; /**< Lowest port number to accept/reject. */
  uint16_t prt_max; /**< Highest port number to accept/reject. */
} 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, NUL-terminated. */
  char *dir_z; /**< Compressed contents of this object. */
  size_t dir_len; /**< Length of <b>dir</b> (not counting its NUL). */
  size_t dir_z_len; /**< Length of <b>dir_z</b>. */
  time_t published; /**< When was this object published. */
  digests_t digests; /**< Digests of this object (networkstatus only) */
  int refcnt; /**< Reference count for this cached_dir_t. */
} cached_dir_t;

/** Enum used to remember where a signed_descriptor_t is stored and how to
 * manage the memory for signed_descriptor_body.  */
typedef enum {
  /** The descriptor isn't stored on disk at all: the copy in memory is
   * canonical; the saved_offset field is meaningless. */
  SAVED_NOWHERE=0,
  /** The descriptor is stored in the cached_routers file: the
   * signed_descriptor_body is meaningless; the signed_descriptor_len and
   * saved_offset are used to index into the mmaped cache file. */
  SAVED_IN_CACHE,
  /** The descriptor is stored in the cached_routers.new file: the
   * signed_descriptor_body and saved_offset fields are both set. */
  /* FFFF (We could also mmap the file and grow the mmap as needed, or
   * lazy-load the descriptor text by using seek and read.  We don't, for
   * now.)
   */
  SAVED_IN_JOURNAL
} saved_location_t;
#define saved_location_bitfield_t ENUM_BF(saved_location_t)

/** Enumeration: what kind of download schedule are we using for a given
 * object? */
typedef enum {
  DL_SCHED_GENERIC = 0,
  DL_SCHED_CONSENSUS = 1,
  DL_SCHED_BRIDGE = 2,
} download_schedule_t;
#define download_schedule_bitfield_t ENUM_BF(download_schedule_t)

/** Information about our plans for retrying downloads for a downloadable
 * object. */
typedef struct download_status_t {
  time_t next_attempt_at; /**< When should we try downloading this descriptor
                           * again? */
  uint8_t n_download_failures; /**< Number of failures trying to download the
                                * most recent descriptor. */
  download_schedule_bitfield_t schedule : 8;
} download_status_t;

/** If n_download_failures is this high, the download can never happen. */
#define IMPOSSIBLE_TO_DOWNLOAD 255

/** The max size we expect router descriptor annotations we create to
 * be. We'll accept larger ones if we see them on disk, but we won't
 * create any that are larger than this. */
#define ROUTER_ANNOTATION_BUF_LEN 256

/** Information need to cache an onion router's descriptor. */
typedef struct signed_descriptor_t {
  /** Pointer to the raw server descriptor, preceded by annotations.  Not
   * necessarily NUL-terminated.  If saved_location is SAVED_IN_CACHE, this
   * pointer is null. */
  char *signed_descriptor_body;
  /** Length of the annotations preceding the server descriptor. */
  size_t annotations_len;
  /** Length of the server descriptor. */
  size_t signed_descriptor_len;
  /** Digest of the server descriptor, computed as specified in
   * dir-spec.txt. */
  char signed_descriptor_digest[DIGEST_LEN];
  /** Identity digest of the router. */
  char identity_digest[DIGEST_LEN];
  /** Declared publication time of the descriptor. */
  time_t published_on;
  /** For routerdescs only: digest of the corresponding extrainfo. */
  char extra_info_digest[DIGEST_LEN];
  /** For routerdescs only: Status of downloading the corresponding
   * extrainfo. */
  download_status_t ei_dl_status;
  /** Where is the descriptor saved? */
  saved_location_t saved_location;
  /** If saved_location is SAVED_IN_CACHE or SAVED_IN_JOURNAL, the offset of
   * this descriptor in the corresponding file. */
  off_t saved_offset;
  /** What position is this descriptor within routerlist->routers or
   * routerlist->old_routers? -1 for none. */
  int routerlist_index;
  /** The valid-until time of the most recent consensus that listed this
   * descriptor.  0 for "never listed in a consensus, so far as we know." */
  time_t last_listed_as_valid_until;
  /* If true, we do not ever try to save this object in the cache. */
  unsigned int do_not_cache : 1;
  /* If true, this item is meant to represent an extrainfo. */
  unsigned int is_extrainfo : 1;
  /* If true, we got an extrainfo for this item, and the digest was right,
   * but it was incompatible. */
  unsigned int extrainfo_is_bogus : 1;
  /* If true, we are willing to transmit this item unencrypted. */
  unsigned int send_unencrypted : 1;
} signed_descriptor_t;

/** A signed integer representing a country code. */
typedef int16_t country_t;

/** Information about another onion router in the network. */
typedef struct {
  signed_descriptor_t cache_info;
  char *nickname; /**< Human-readable OR name. */

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

  /** A router's IPv6 address, if it has one. */
  /* XXXXX187 Actually these should probably be part of a list of addresses,
   * not just a special case.  Use abstractions to access these; don't do it
   * directly. */
  tor_addr_t ipv6_addr;
  uint16_t ipv6_orport;

  crypto_pk_t *onion_pkey; /**< Public RSA key for onions. */
  crypto_pk_t *identity_pkey;  /**< Public RSA key for signing. */
  /** Public curve25519 key for onions */
  curve25519_public_key_t *onion_curve25519_pkey;

  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;
  smartlist_t *exit_policy; /**< What streams will this OR permit
                             * to exit on IPv4?  NULL for 'reject *:*'. */
  /** What streams will this OR permit to exit on IPv6?
   * NULL for 'reject *:*' */
  struct short_policy_t *ipv6_exit_policy;
  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 */
  unsigned int caches_extra_info:1; /**< Whether the router says it caches and
                                     * serves extrainfo documents. */
  unsigned int allow_single_hop_exits:1;  /**< Whether the router says
                                           * it allows single hop exits. */

  unsigned int wants_to_be_hs_dir:1; /**< True iff this router claims to be
                                      * a hidden service directory. */
  unsigned int policy_is_reject_star:1; /**< True iff the exit policy for this
                                         * router rejects everything. */
  /** True if, after we have added this router, we should re-launch
   * tests for it. */
  unsigned int needs_retest_if_added:1;

/** Tor can use this router for general positions in circuits; we got it
 * from a directory server as usual, or we're an authority and a server
 * uploaded it. */
#define ROUTER_PURPOSE_GENERAL 0
/** Tor should avoid using this router for circuit-building: we got it
 * from a crontroller.  If the controller wants to use it, it'll have to
 * ask for it by identity. */
#define ROUTER_PURPOSE_CONTROLLER 1
/** Tor should use this router only for bridge positions in circuits: we got
 * it via a directory request from the bridge itself, or a bridge
 * authority. x*/
#define ROUTER_PURPOSE_BRIDGE 2
/** Tor should not use this router; it was marked in cached-descriptors with
 * a purpose we didn't recognize. */
#define ROUTER_PURPOSE_UNKNOWN 255

  /* In what way did we find out about this router?  One of ROUTER_PURPOSE_*.
   * Routers of different purposes are kept segregated and used for different
   * things; see notes on ROUTER_PURPOSE_* macros above.
   */
  uint8_t purpose;
} routerinfo_t;

/** Information needed to keep and cache a signed extra-info document. */
typedef struct extrainfo_t {
  signed_descriptor_t cache_info;
  /** The router's nickname. */
  char nickname[MAX_NICKNAME_LEN+1];
  /** True iff we found the right key for this extra-info, verified the
   * signature, and found it to be bad. */
  unsigned int bad_sig : 1;
  /** If present, we didn't have the right key to verify this extra-info,
   * so this is a copy of the signature in the document. */
  char *pending_sig;
  /** Length of pending_sig. */
  size_t pending_sig_len;
} extrainfo_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. */
  /** Digest of the router's most recent descriptor or microdescriptor.
   * If it's a descriptor, we only use the first DIGEST_LEN bytes. */
  char descriptor_digest[DIGEST256_LEN];
  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. */
  tor_addr_t ipv6_addr; /**< IPv6 address for this router. */
  uint16_t ipv6_orport; /**<IPV6 OR port for this router. */
  unsigned int is_authority:1; /**< True iff this router is an authority. */
  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. */
  /** True iff this router is called 'running' in the consensus. We give it
   * this funny name so that we don't accidentally use this bit as a view of
   * whether we think the router is *currently* running.  If that's what you
   * want to know, look at is_running in node_t. */
  unsigned int is_flagged_running:1;
  unsigned int is_named:1; /**< True iff "nickname" belongs to this router. */
  unsigned int is_unnamed:1; /**< True iff "nickname" belongs to another
                              * router. */
  unsigned int is_valid:1; /**< True iff this router isn't invalid. */
  unsigned int is_possible_guard:1; /**< True iff this router would be a good
                                     * choice as an entry guard. */
  unsigned int is_bad_exit:1; /**< True iff this node is a bad choice for
                               * an exit node. */
  unsigned int is_bad_directory:1; /**< Do we think this directory is junky,
                                    * underpowered, or otherwise useless? */
  unsigned int is_hs_dir:1; /**< True iff this router is a v2-or-later hidden
                             * service directory. */
  /** True iff we know version info for this router. (i.e., a "v" entry was
   * included.)  We'll replace all these with a big tor_version_t or a char[]
   * if the number of traits we care about ever becomes incredibly big. */
  unsigned int version_known:1;

  /** True iff this router is a version that, if it caches directory info,
   * we can get microdescriptors from. */
  unsigned int version_supports_microdesc_cache:1;
  /** True iff this router is a version that allows DATA cells to arrive on
   * a stream before it has sent a CONNECTED cell. */
  unsigned int version_supports_optimistic_data:1;
  /** True iff this router has a version that allows it to accept EXTEND2
   * cells */
  unsigned int version_supports_extend2_cells:1;

  unsigned int has_bandwidth:1; /**< The vote/consensus had bw info */
  unsigned int has_exitsummary:1; /**< The vote/consensus had exit summaries */
  unsigned int bw_is_unmeasured:1; /**< This is a consensus entry, with
                                    * the Unmeasured flag set. */

  uint32_t bandwidth_kb; /**< Bandwidth (capacity) of the router as reported in
                       * the vote/consensus, in kilobytes/sec. */
  char *exitsummary; /**< exit policy summary -
                      * XXX weasel: this probably should not stay a string. */

  /* ---- The fields below aren't derived from the networkstatus; they
   * hold local information only. */

  time_t last_dir_503_at; /**< When did this router last tell us that it
                           * was too busy to serve directory info? */
  download_status_t dl_status;

} routerstatus_t;

/** A single entry in a parsed policy summary, describing a range of ports. */
typedef struct short_policy_entry_t {
  uint16_t min_port, max_port;
} short_policy_entry_t;

/** A short_poliy_t is the parsed version of a policy summary. */
typedef struct short_policy_t {
  /** True if the members of 'entries' are port ranges to accept; false if
   * they are port ranges to reject */
  unsigned int is_accept : 1;
  /** The actual number of values in 'entries'. */
  unsigned int n_entries : 31;
  /** An array of 0 or more short_policy_entry_t values, each describing a
   * range of ports that this policy accepts or rejects (depending on the
   * value of is_accept).
   */
  short_policy_entry_t entries[FLEXIBLE_ARRAY_MEMBER];
} short_policy_t;

/** A microdescriptor is the smallest amount of information needed to build a
 * circuit through a router.  They are generated by the directory authorities,
 * using information from the uploaded routerinfo documents.  They are not
 * self-signed, but are rather authenticated by having their hash in a signed
 * networkstatus document. */
typedef struct microdesc_t {
  /** Hashtable node, used to look up the microdesc by its digest. */
  HT_ENTRY(microdesc_t) node;

  /* Cache information */

  /**  When was this microdescriptor last listed in a consensus document?
   * Once a microdesc has been unlisted long enough, we can drop it.
   */
  time_t last_listed;
  /** Where is this microdescriptor currently stored? */
  saved_location_bitfield_t saved_location : 3;
  /** If true, do not attempt to cache this microdescriptor on disk. */
  unsigned int no_save : 1;
  /** If true, this microdesc has an entry in the microdesc_map */
  unsigned int held_in_map : 1;
  /** Reference count: how many node_ts have a reference to this microdesc? */
  unsigned int held_by_nodes;

  /** If saved_location == SAVED_IN_CACHE, this field holds the offset of the
   * microdescriptor in the cache. */
  off_t off;

  /* The string containing the microdesc. */

  /** A pointer to the encoded body of the microdescriptor.  If the
   * saved_location is SAVED_IN_CACHE, then the body is a pointer into an
   * mmap'd region.  Otherwise, it is a malloc'd string.  The string might not
   * be NUL-terminated; take the length from <b>bodylen</b>. */
  char *body;
  /** The length of the microdescriptor in <b>body</b>. */
  size_t bodylen;
  /** A SHA256-digest of the microdescriptor. */
  char digest[DIGEST256_LEN];

  /* Fields in the microdescriptor. */

  /** As routerinfo_t.onion_pkey */
  crypto_pk_t *onion_pkey;
  /** As routerinfo_t.onion_curve25519_pkey */
  curve25519_public_key_t *onion_curve25519_pkey;
  /** As routerinfo_t.ipv6_add */
  tor_addr_t ipv6_addr;
  /** As routerinfo_t.ipv6_orport */
  uint16_t ipv6_orport;
  /** As routerinfo_t.family */
  smartlist_t *family;
  /** IPv4 exit policy summary */
  short_policy_t *exit_policy;
  /** IPv6 exit policy summary */
  short_policy_t *ipv6_exit_policy;

} microdesc_t;

/** A node_t represents a Tor router.
 *
 * Specifically, a node_t is a Tor router as we are using it: a router that
 * we are considering for circuits, connections, and so on.  A node_t is a
 * thin wrapper around the routerstatus, routerinfo, and microdesc for a
 * single wrapper, and provides a consistent interface for all of them.
 *
 * Also, a node_t has mutable state.  While a routerinfo, a routerstatus,
 * and a microdesc have[*] only the information read from a router
 * descriptor, a consensus entry, and a microdescriptor (respectively)...
 * a node_t has flags based on *our own current opinion* of the node.
 *
 * [*] Actually, there is some leftover information in each that is mutable.
 *  We should try to excise that.
 */
typedef struct node_t {
  /* Indexing information */

  /** Used to look up the node_t by its identity digest. */
  HT_ENTRY(node_t) ht_ent;
  /** Position of the node within the list of nodes */
  int nodelist_idx;

  /** The identity digest of this node_t.  No more than one node_t per
   * identity may exist at a time. */
  char identity[DIGEST_LEN];

  microdesc_t *md;
  routerinfo_t *ri;
  routerstatus_t *rs;

  /* local info: copied from routerstatus, then possibly frobbed based
   * on experience.  Authorities set this stuff directly.  Note that
   * these reflect knowledge of the primary (IPv4) OR port only.  */

  unsigned int is_running:1; /**< As far as we know, is this OR currently
                              * running? */
  unsigned int is_valid:1; /**< Has a trusted dirserver validated this OR?
                            *  (For Authdir: Have we validated this OR?) */
  unsigned int is_fast:1; /** Do we think this is a fast OR? */
  unsigned int is_stable:1; /** Do we think this is a stable OR? */
  unsigned int is_possible_guard:1; /**< Do we think this is an OK guard? */
  unsigned int is_exit:1; /**< Do we think this is an OK exit? */
  unsigned int is_bad_exit:1; /**< Do we think this exit is censored, borked,
                               * or otherwise nasty? */
  unsigned int is_bad_directory:1; /**< Do we think this directory is junky,
                                    * underpowered, or otherwise useless? */
  unsigned int is_hs_dir:1; /**< True iff this router is a hidden service
                             * directory according to the authorities. */

  /* Local info: warning state. */

  unsigned int name_lookup_warned:1; /**< Have we warned the user for referring
                                      * to this (unnamed) router by nickname?
                                      */

  /** Local info: we treat this node as if it rejects everything */
  unsigned int rejects_all:1;

  /** Local info: this node is in our list of guards */
  unsigned int using_as_guard:1;

  /* Local info: derived. */

  /** True if the IPv6 OR port is preferred over the IPv4 OR port.  */
  unsigned int ipv6_preferred:1;

  /** According to the geoip db what country is this router in? */
  /* XXXprop186 what is this suppose to mean with multiple OR ports? */
  country_t country;

  /* 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;        /* IPv4. */
  time_t last_reachable6;       /* IPv6. */

} node_t;

/** Linked list of microdesc hash lines for a single router in a directory
 * vote.
 */
typedef struct vote_microdesc_hash_t {
  /** Next element in the list, or NULL. */
  struct vote_microdesc_hash_t *next;
  /** The raw contents of the microdesc hash line, from the "m" through the
   * newline. */
  char *microdesc_hash_line;
} vote_microdesc_hash_t;

/** The claim about a single router, made in a vote. */
typedef struct vote_routerstatus_t {
  routerstatus_t status; /**< Underlying 'status' object for this router.
                          * Flags are redundant. */
  /** How many known-flags are allowed in a vote? This is the width of
   * the flags field of vote_routerstatus_t */
#define MAX_KNOWN_FLAGS_IN_VOTE 64
  uint64_t flags; /**< Bit-field for all recognized flags; index into
                   * networkstatus_t.known_flags. */
  char *version; /**< The version that the authority says this router is
                  * running. */
  unsigned int has_measured_bw:1; /**< The vote had a measured bw */
  uint32_t measured_bw_kb; /**< Measured bandwidth (capacity) of the router */
  /** The hash or hashes that the authority claims this microdesc has. */
  vote_microdesc_hash_t *microdesc;
} vote_routerstatus_t;

/** A signature of some document by an authority. */
typedef struct document_signature_t {
  /** Declared SHA-1 digest of this voter's identity key */
  char identity_digest[DIGEST_LEN];
  /** Declared SHA-1 digest of signing key used by this voter. */
  char signing_key_digest[DIGEST_LEN];
  /** Algorithm used to compute the digest of the document. */
  digest_algorithm_t alg;
  /** Signature of the signed thing. */
  char *signature;
  /** Length of <b>signature</b> */
  int signature_len;
  unsigned int bad_signature : 1; /**< Set to true if we've tried to verify
                                   * the sig, and we know it's bad. */
  unsigned int good_signature : 1; /**< Set to true if we've verified the sig
                                     * as good. */
} document_signature_t;

/** Information about a single voter in a vote or a consensus. */
typedef struct networkstatus_voter_info_t {
  /** Declared SHA-1 digest of this voter's identity key */
  char identity_digest[DIGEST_LEN];
  char *nickname; /**< Nickname of this voter */
  /** Digest of this voter's "legacy" identity key, if any.  In vote only; for
   * consensuses, we treat legacy keys as additional signers. */
  char legacy_id_digest[DIGEST_LEN];
  char *address; /**< Address of this voter, in string format. */
  uint32_t addr; /**< Address of this voter, in IPv4, in host order. */
  uint16_t dir_port; /**< Directory port of this voter */
  uint16_t or_port; /**< OR port of this voter */
  char *contact; /**< Contact information for this voter. */
  char vote_digest[DIGEST_LEN]; /**< Digest of this voter's vote, as signed. */

  /* Nothing from here on is signed. */
  /** The signature of the document and the signature's status. */
  smartlist_t *sigs;
} networkstatus_voter_info_t;

/** Enumerates the possible seriousness values of a networkstatus document. */
typedef enum {
  NS_TYPE_VOTE,
  NS_TYPE_CONSENSUS,
  NS_TYPE_OPINION,
} networkstatus_type_t;

/** Enumerates recognized flavors of a consensus networkstatus document.  All
 * flavors of a consensus are generated from the same set of votes, but they
 * present different types information to different versions of Tor. */
typedef enum {
  FLAV_NS = 0,
  FLAV_MICRODESC = 1,
} consensus_flavor_t;

/** How many different consensus flavors are there? */
#define N_CONSENSUS_FLAVORS ((int)(FLAV_MICRODESC)+1)

/** A common structure to hold a v3 network status vote, or a v3 network
 * status consensus. */
typedef struct networkstatus_t {
  networkstatus_type_t type; /**< Vote, consensus, or opinion? */
  consensus_flavor_t flavor; /**< If a consensus, what kind? */
  unsigned int has_measured_bws : 1;/**< True iff this networkstatus contains
                                     * measured= bandwidth values. */

  time_t published; /**< Vote only: Time when vote was written. */
  time_t valid_after; /**< Time after which this vote or consensus applies. */
  time_t fresh_until; /**< Time before which this is the most recent vote or
                       * consensus. */
  time_t valid_until; /**< Time after which this vote or consensus should not
                       * be used. */

  /** Consensus only: what method was used to produce this consensus? */
  int consensus_method;
  /** Vote only: what methods is this voter willing to use? */
  smartlist_t *supported_methods;

  /** How long does this vote/consensus claim that authorities take to
   * distribute their votes to one another? */
  int vote_seconds;
  /** How long does this vote/consensus claim that authorities take to
   * distribute their consensus signatures to one another? */
  int dist_seconds;

  /** Comma-separated list of recommended client software, or NULL if this
   * voter has no opinion. */
  char *client_versions;
  char *server_versions;
  /** List of flags that this vote/consensus applies to routers.  If a flag is
   * not listed here, the voter has no opinion on what its value should be. */
  smartlist_t *known_flags;

  /** List of key=value strings for the parameters in this vote or
   * consensus, sorted by key. */
  smartlist_t *net_params;

  /** List of key=value strings for the bw weight parameters in the
   * consensus. */
  smartlist_t *weight_params;

  /** List of networkstatus_voter_info_t.  For a vote, only one element
   * is included.  For a consensus, one element is included for every voter
   * whose vote contributed to the consensus. */
  smartlist_t *voters;

  struct authority_cert_t *cert; /**< Vote only: the voter's certificate. */

  /** Digests of this document, as signed. */
  digests_t digests;

  /** List of router statuses, sorted by identity digest.  For a vote,
   * the elements are vote_routerstatus_t; for a consensus, the elements
   * are routerstatus_t. */
  smartlist_t *routerstatus_list;

  /** If present, a map from descriptor digest to elements of
   * routerstatus_list. */
  digestmap_t *desc_digest_map;
} networkstatus_t;

/** A set of signatures for a networkstatus consensus.  Unless otherwise
 * noted, all fields are as for networkstatus_t. */
typedef struct ns_detached_signatures_t {
  time_t valid_after;
  time_t fresh_until;
  time_t valid_until;
  strmap_t *digests; /**< Map from flavor name to digestset_t */
  strmap_t *signatures; /**< Map from flavor name to list of
                         * document_signature_t */
} ns_detached_signatures_t;

/** Allowable types of desc_store_t. */
typedef enum store_type_t {
  ROUTER_STORE = 0,
  EXTRAINFO_STORE = 1
} store_type_t;

/** A 'store' is a set of descriptors saved on disk, with accompanying
 * journal, mmaped as needed, rebuilt as needed. */
typedef struct desc_store_t {
  /** Filename (within DataDir) for the store.  We append .tmp to this
   * filename for a temporary file when rebuilding the store, and .new to this
   * filename for the journal. */
  const char *fname_base;
  /** Human-readable description of what this store contains. */
  const char *description;

  tor_mmap_t *mmap; /**< A mmap for the main file in the store. */

  store_type_t type; /**< What's stored in this store? */

  /** The size of the router log, in bytes. */
  size_t journal_len;
  /** The size of the router store, in bytes. */
  size_t store_len;
  /** Total bytes dropped since last rebuild: this is space currently
   * used in the cache and the journal that could be freed by a rebuild. */
  size_t bytes_dropped;
} desc_store_t;

/** Contents of a directory of onion routers. */
typedef struct {
  /** Map from server identity digest to a member of routers. */
  struct digest_ri_map_t *identity_map;
  /** Map from server descriptor digest to a signed_descriptor_t from
   * routers or old_routers. */
  struct digest_sd_map_t *desc_digest_map;
  /** Map from extra-info digest to an extrainfo_t.  Only exists for
   * routers in routers or old_routers. */
  struct digest_ei_map_t *extra_info_map;
  /** Map from extra-info digests to a signed_descriptor_t for a router
   * descriptor having that extra-info digest.  Only exists for
   * routers in routers or old_routers. */
  struct digest_sd_map_t *desc_by_eid_map;
  /** List of routerinfo_t for all currently live routers we know. */
  smartlist_t *routers;
  /** List of signed_descriptor_t for older router descriptors we're
   * caching. */
  smartlist_t *old_routers;
  /** Store holding server descriptors.  If present, any router whose
   * cache_info.saved_location == SAVED_IN_CACHE is stored in this file
   * starting at cache_info.saved_offset */
  desc_store_t desc_store;
  /** Store holding extra-info documents. */
  desc_store_t extrainfo_store;
} 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. Note that for onehop
 * general-purpose tunnels, the onion_key is NULL. */
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. */
  uint16_t port; /**< OR port. */
  tor_addr_t addr; /**< IP address. */
  crypto_pk_t *onion_key; /**< Current onionskin key. */
#ifdef CURVE25519_ENABLED
  curve25519_public_key_t curve25519_onion_key;
#endif
} extend_info_t;

/** Certificate for v3 directory protocol: binds long-term authority identity
 * keys to medium-term authority signing keys. */
typedef struct authority_cert_t {
  /** Information relating to caching this cert on disk and looking it up. */
  signed_descriptor_t cache_info;
  /** This authority's long-term authority identity key. */
  crypto_pk_t *identity_key;
  /** This authority's medium-term signing key. */
  crypto_pk_t *signing_key;
  /** The digest of <b>signing_key</b> */
  char signing_key_digest[DIGEST_LEN];
  /** The listed expiration time of this certificate. */
  time_t expires;
  /** This authority's IPv4 address, in host order. */
  uint32_t addr;
  /** This authority's directory port. */
  uint16_t dir_port;
} authority_cert_t;

/** Bitfield enum type listing types of information that directory authorities
 * can be authoritative about, and that directory caches may or may not cache.
 *
 * Note that the granularity here is based on authority granularity and on
 * cache capabilities.  Thus, one particular bit may correspond in practice to
 * a few types of directory info, so long as every authority that pronounces
 * officially about one of the types prounounces officially about all of them,
 * and so long as every cache that caches one of them caches all of them.
 */
typedef enum {
  NO_DIRINFO      = 0,
  /** Serves/signs v3 directory information: votes, consensuses, certs */
  V3_DIRINFO      = 1 << 2,
  /** Serves bridge descriptors. */
  BRIDGE_DIRINFO  = 1 << 4,
  /** Serves extrainfo documents. */
  EXTRAINFO_DIRINFO=1 << 5,
  /** Serves microdescriptors. */
  MICRODESC_DIRINFO=1 << 6,
} dirinfo_type_t;

#define ALL_DIRINFO ((dirinfo_type_t)((1<<7)-1))

#define CRYPT_PATH_MAGIC 0x70127012u

struct fast_handshake_state_t;
struct ntor_handshake_state_t;
#define ONION_HANDSHAKE_TYPE_TAP  0x0000
#define ONION_HANDSHAKE_TYPE_FAST 0x0001
#define ONION_HANDSHAKE_TYPE_NTOR 0x0002
#define MAX_ONION_HANDSHAKE_TYPE 0x0002
typedef struct {
  uint16_t tag;
  union {
    struct fast_handshake_state_t *fast;
    crypto_dh_t *tap;
    struct ntor_handshake_state_t *ntor;
  } u;
} onion_handshake_state_t;

/** 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_t *f_crypto;
  /** Encryption key and counter for cells heading back from the OR at this
   * step. */
  crypto_cipher_t *b_crypto;

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

  /** Current state of the handshake as performed with the OR at this
   * step. */
  onion_handshake_state_t handshake_state;
  /** Diffie-hellman handshake state for performing an introduction
   * operations */
  crypto_dh_t *rend_dh_handshake_state;

  /** Negotiated key material shared with the OR at this step. */
  char rend_circ_nonce[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 cells are we allowed to originate ending
                       * at this step? */
  int deliver_window; /**< How many cells are we willing to deliver originating
                       * at this step? */
} crypt_path_t;

/** A reference-counted pointer to a crypt_path_t, used only to share
 * the final rendezvous cpath to be used on a service-side rendezvous
 * circuit among multiple circuits built in parallel to the same
 * destination rendezvous point. */
typedef struct {
  /** The reference count. */
  unsigned int refcount;
  /** The pointer.  Set to NULL when the crypt_path_t is put into use
   * on an opened rendezvous circuit. */
  crypt_path_t *cpath;
} crypt_path_reference_t;

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

#define DH_KEY_LEN DH_BYTES

/** 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. */
  unsigned int need_uptime : 1;
  /** Whether every node in the circ must have adequate capacity. */
  unsigned int need_capacity : 1;
  /** Whether the last hop was picked with exiting in mind. */
  unsigned int is_internal : 1;
  /** Did we pick this as a one-hop tunnel (not safe for other streams)?
   * These are for encrypted dir conns that exit to this router, not
   * for arbitrary exits from the circuit. */
  unsigned int onehop_tunnel : 1;
  /** The crypt_path_t to append after rendezvous: used for rendezvous. */
  crypt_path_t *pending_final_cpath;
  /** A ref-counted reference to the crypt_path_t to append after
   * rendezvous; used on the service side. */
  crypt_path_reference_t *service_pending_final_cpath_ref;
  /** 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 ORIGIN_CIRCUIT_MAGIC 0x35315243u
#define OR_CIRCUIT_MAGIC 0x98ABC04Fu

struct create_cell_t;

/** Entry in the cell stats list of a circuit; used only if CELL_STATS
 * events are enabled. */
typedef struct testing_cell_stats_entry_t {
  uint8_t command; /**< cell command number. */
  /** Waiting time in centiseconds if this event is for a removed cell,
   * or 0 if this event is for adding a cell to the queue.  22 bits can
   * store more than 11 hours, enough to assume that a circuit with this
   * delay would long have been closed. */
  unsigned int waiting_time:22;
  unsigned int removed:1; /**< 0 for added to, 1 for removed from queue. */
  unsigned int exitward:1; /**< 0 for app-ward, 1 for exit-ward. */
} testing_cell_stats_entry_t;

/**
 * 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 can fill one of two roles.  First, a or_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, an origin_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.
 */
typedef struct circuit_t {
  uint32_t magic; /**< For memory and type debugging: must equal
                   * ORIGIN_CIRCUIT_MAGIC or OR_CIRCUIT_MAGIC. */

  /** The channel that is next in this circuit. */
  channel_t *n_chan;

  /**
   * The circuit_id used in the next (forward) hop of this circuit;
   * this is unique to n_chan, but this ordered pair is globally
   * unique:
   *
   * (n_chan->global_identifier, n_circ_id)
   */
  circid_t n_circ_id;

  /**
   * Circuit mux associated with n_chan to which this circuit is attached;
   * NULL if we have no n_chan.
   */
  circuitmux_t *n_mux;

  /** Queue of cells waiting to be transmitted on n_chan */
  cell_queue_t n_chan_cells;

  /**
   * The hop to which we want to extend this circuit.  Should be NULL if
   * the circuit has attached to a channel.
   */
  extend_info_t *n_hop;

  /** True iff we are waiting for n_chan_cells to become less full before
   * allowing p_streams to add any more cells. (Origin circuit only.) */
  unsigned int streams_blocked_on_n_chan : 1;
  /** True iff we are waiting for p_chan_cells to become less full before
   * allowing n_streams to add any more cells. (OR circuit only.) */
  unsigned int streams_blocked_on_p_chan : 1;

  /** True iff we have queued a delete backwards on this circuit, but not put
   * it on the output buffer. */
  unsigned int p_delete_pending : 1;
  /** True iff we have queued a delete forwards on this circuit, but not put
   * it on the output buffer. */
  unsigned int n_delete_pending : 1;

  /** True iff this circuit has received a DESTROY cell in either direction */
  unsigned int received_destroy : 1;

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

  /** 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;

  /** Temporary field used during circuits_handle_oom. */
  uint32_t age_tmp;

  /** For storage while n_chan is pending (state CIRCUIT_STATE_CHAN_WAIT). */
  struct create_cell_t *n_chan_create_cell;

  /** When did circuit construction actually begin (ie send the
   * CREATE cell or begin cannibalization).
   *
   * Note: This timer will get reset if we decide to cannibalize
   * a circuit. It may also get reset during certain phases of hidden
   * service circuit use.
   *
   * We keep this timestamp with a higher resolution than most so that the
   * circuit-build-time tracking code can get millisecond resolution.
   */
  struct timeval timestamp_began;

  /** This timestamp marks when the init_circuit_base constructor ran. */
  struct timeval timestamp_created;

  /** When the circuit was first used, or 0 if the circuit is clean.
   *
   * XXXX023 Note that some code will artifically adjust this value backward
   * in time in order to indicate that a circuit shouldn't be used for new
   * streams, but that it can stay alive as long as it has streams on it.
   * That's a kludge we should fix.
   *
   * XXX023 The CBT code uses this field to record when HS-related
   * circuits entered certain states.  This usage probably won't
   * interfere with this field's primary purpose, but we should
   * document it more thoroughly to make sure of that.
   */
  time_t timestamp_dirty;

  uint16_t 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? */

  /** Unique ID for measuring tunneled network status requests. */
  uint64_t dirreq_id;

  /** Next circuit in linked list of all circuits (global_circuitlist). */
  TOR_LIST_ENTRY(circuit_t) head;

  /** Next circuit in the doubly-linked ring of circuits waiting to add
   * cells to n_conn.  NULL if we have no cells pending, or if we're not
   * linked to an OR connection. */
  struct circuit_t *next_active_on_n_chan;
  /** Previous circuit in the doubly-linked ring of circuits waiting to add
   * cells to n_conn.  NULL if we have no cells pending, or if we're not
   * linked to an OR connection. */
  struct circuit_t *prev_active_on_n_chan;

  /** Various statistics about cells being added to or removed from this
   * circuit's queues; used only if CELL_STATS events are enabled and
   * cleared after being sent to control port. */
  smartlist_t *testing_cell_stats;
} circuit_t;

/** Largest number of relay_early cells that we can send on a given
 * circuit. */
#define MAX_RELAY_EARLY_CELLS_PER_CIRCUIT 8

/**
 * Describes the circuit building process in simplified terms based
 * on the path bias accounting state for a circuit.
 *
 * NOTE: These state values are enumerated in the order for which we
 * expect circuits to transition through them. If you add states,
 * you need to preserve this overall ordering. The various pathbias
 * state transition and accounting functions (pathbias_mark_* and
 * pathbias_count_*) contain ordinal comparisons to enforce proper
 * state transitions for corrections.
 *
 * This state machine and the associated logic was created to prevent
 * miscounting due to unknown cases of circuit reuse. See also tickets
 * #6475 and #7802.
 */
typedef enum {
    /** This circuit is "new". It has not yet completed a first hop
     * or been counted by the path bias code. */
    PATH_STATE_NEW_CIRC = 0,
    /** This circuit has completed one/two hops, and has been counted by
     * the path bias logic. */
    PATH_STATE_BUILD_ATTEMPTED = 1,
    /** This circuit has been completely built */
    PATH_STATE_BUILD_SUCCEEDED = 2,
    /** Did we try to attach any SOCKS streams or hidserv introductions to
      * this circuit?
      *
      * Note: If we ever implement end-to-end stream timing through test
      * stream probes (#5707), we must *not* set this for those probes
      * (or any other automatic streams) because the adversary could
      * just tag at a later point.
      */
    PATH_STATE_USE_ATTEMPTED = 3,
    /** Did any SOCKS streams or hidserv introductions actually succeed on
      * this circuit?
      *
      * If any streams detatch/fail from this circuit, the code transitions
      * the circuit back to PATH_STATE_USE_ATTEMPTED to ensure we probe. See
      * pathbias_mark_use_rollback() for that.
      */
    PATH_STATE_USE_SUCCEEDED = 4,

    /**
     * This is a special state to indicate that we got a corrupted
     * relay cell on a circuit and we don't intend to probe it.
     */
    PATH_STATE_USE_FAILED = 5,

    /**
     * This is a special state to indicate that we already counted
     * the circuit. Used to guard against potential state machine
     * violations.
     */
    PATH_STATE_ALREADY_COUNTED = 6,
} path_state_t;
#define path_state_bitfield_t ENUM_BF(path_state_t)

/** An origin_circuit_t holds data necessary to build and use a circuit.
 */
typedef struct origin_circuit_t {
  circuit_t base_;

  /** Linked list of AP streams (or EXIT streams if hidden service)
   * associated with this circuit. */
  edge_connection_t *p_streams;

  /** Bytes read from any attached stream since last call to
   * control_event_circ_bandwidth_used().  Only used if we're configured
   * to emit CIRC_BW events. */
  uint32_t n_read_circ_bw;

  /** Bytes written to any attached stream since last call to
   * control_event_circ_bandwidth_used().  Only used if we're configured
   * to emit CIRC_BW events. */
  uint32_t n_written_circ_bw;

  /** 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.
   */
  crypt_path_t *cpath;

  /** Holds all rendezvous data on either client or service side. */
  rend_data_t *rend_data;

  /** How many more relay_early cells can we send on this circuit, according
   * to the specification? */
  unsigned int remaining_relay_early_cells : 4;

  /** Set if this circuit is insanely old and we already informed the user */
  unsigned int is_ancient : 1;

  /** Set if this circuit has already been opened. Used to detect
   * cannibalized circuits. */
  unsigned int has_opened : 1;

  /**
   * Path bias state machine. Used to ensure integrity of our
   * circuit building and usage accounting. See path_state_t
   * for more details.
   */
  path_state_bitfield_t path_state : 3;

  /* If this flag is set, we should not consider attaching any more
   * connections to this circuit. */
  unsigned int unusable_for_new_conns : 1;

  /**
   * Tristate variable to guard against pathbias miscounting
   * due to circuit purpose transitions changing the decision
   * of pathbias_should_count(). This variable is informational
   * only. The current results of pathbias_should_count() are
   * the official decision for pathbias accounting.
   */
  uint8_t pathbias_shouldcount;
#define PATHBIAS_SHOULDCOUNT_UNDECIDED 0
#define PATHBIAS_SHOULDCOUNT_IGNORED   1
#define PATHBIAS_SHOULDCOUNT_COUNTED   2

  /** For path probing. Store the temporary probe stream ID
   * for response comparison */
  streamid_t pathbias_probe_id;

  /** For path probing. Store the temporary probe address nonce
   * (in host byte order) for response comparison. */
  uint32_t pathbias_probe_nonce;

  /** Set iff this is a hidden-service circuit which has timed out
   * according to our current circuit-build timeout, but which has
   * been kept around because it might still succeed in connecting to
   * its destination, and which is not a fully-connected rendezvous
   * circuit.
   *
   * (We clear this flag for client-side rendezvous circuits when they
   * are 'joined' to the other side's rendezvous circuit, so that
   * connection_ap_handshake_attach_circuit can put client streams on
   * the circuit.  We also clear this flag for service-side rendezvous
   * circuits when they are 'joined' to a client's rend circ, but only
   * for symmetry with the client case.  Client-side introduction
   * circuits are closed when we get a joined rend circ, and
   * service-side introduction circuits never have this flag set.) */
  unsigned int hs_circ_has_timed_out : 1;

  /** Set iff this circuit has been given a relaxed timeout because
   * no circuits have opened. Used to prevent spamming logs. */
  unsigned int relaxed_timeout : 1;

  /** Set iff this is a service-side rendezvous circuit for which a
   * new connection attempt has been launched.  We consider launching
   * a new service-side rend circ to a client when the previous one
   * fails; now that we don't necessarily close a service-side rend
   * circ when we launch a new one to the same client, this flag keeps
   * us from launching two retries for the same failed rend circ. */
  unsigned int hs_service_side_rend_circ_has_been_relaunched : 1;

  /** What commands were sent over this circuit that decremented the
   * RELAY_EARLY counter? This is for debugging task 878. */
  uint8_t relay_early_commands[MAX_RELAY_EARLY_CELLS_PER_CIRCUIT];

  /** How many RELAY_EARLY cells have been sent over this circuit? This is
   * for debugging task 878, too. */
  int relay_early_cells_sent;

  /** The next stream_id that will be tried when we're attempting to
   * construct a new AP stream originating at this circuit. */
  streamid_t next_stream_id;

  /* The intro key replaces the hidden service's public key if purpose is
   * S_ESTABLISH_INTRO or S_INTRO, provided that no unversioned rendezvous
   * descriptor is used. */
  crypto_pk_t *intro_key;

  /** 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;

  /** True if we have associated one stream to this circuit, thereby setting
   * the isolation paramaters for this circuit.  Note that this doesn't
   * necessarily mean that we've <em>attached</em> any streams to the circuit:
   * we may only have marked up this circuit during the launch process.
   */
  unsigned int isolation_values_set : 1;
  /** True iff any stream has <em>ever</em> been attached to this circuit.
   *
   * In a better world we could use timestamp_dirty for this, but
   * timestamp_dirty is far too overloaded at the moment.
   */
  unsigned int isolation_any_streams_attached : 1;

  /** A bitfield of ISO_* flags for every isolation field such that this
   * circuit has had streams with more than one value for that field
   * attached to it. */
  uint8_t isolation_flags_mixed;

  /** @name Isolation parameters
   *
   * If any streams have been associated with this circ (isolation_values_set
   * == 1), and all streams associated with the circuit have had the same
   * value for some field ((isolation_flags_mixed & ISO_FOO) == 0), then these
   * elements hold the value for that field.
   *
   * Note again that "associated" is not the same as "attached": we
   * preliminarily associate streams with a circuit while the circuit is being
   * launched, so that we can tell whether we need to launch more circuits.
   *
   * @{
   */
  uint8_t client_proto_type;
  uint8_t client_proto_socksver;
  uint16_t dest_port;
  tor_addr_t client_addr;
  char *dest_address;
  int session_group;
  unsigned nym_epoch;
  size_t socks_username_len;
  uint8_t socks_password_len;
  /* Note that the next two values are NOT NUL-terminated; see
     socks_username_len and socks_password_len for their lengths. */
  char *socks_username;
  char *socks_password;
  /** Global identifier for the first stream attached here; used by
   * ISO_STREAM. */
  uint64_t associated_isolated_stream_global_id;
  /**@}*/
  /** A list of addr_policy_t for this circuit in particular. Used by
   * adjust_exit_policy_from_exitpolicy_failure.
   */
  smartlist_t *prepend_policy;
} origin_circuit_t;

struct onion_queue_t;

/** An or_circuit_t holds information needed to implement a circuit at an
 * OR. */
typedef struct or_circuit_t {
  circuit_t base_;

  /** Next circuit in the doubly-linked ring of circuits waiting to add
   * cells to p_chan.  NULL if we have no cells pending, or if we're not
   * linked to an OR connection. */
  struct circuit_t *next_active_on_p_chan;
  /** Previous circuit in the doubly-linked ring of circuits waiting to add
   * cells to p_chan.  NULL if we have no cells pending, or if we're not
   * linked to an OR connection. */
  struct circuit_t *prev_active_on_p_chan;
  /** Pointer to an entry on the onion queue, if this circuit is waiting for a
   * chance to give an onionskin to a cpuworker. Used only in onion.c */
  struct onion_queue_t *onionqueue_entry;

  /** The circuit_id used in the previous (backward) hop of this circuit. */
  circid_t p_circ_id;
  /** Queue of cells waiting to be transmitted on p_conn. */
  cell_queue_t p_chan_cells;
  /** The channel that is previous in this circuit. */
  channel_t *p_chan;
  /**
   * Circuit mux associated with p_chan to which this circuit is attached;
   * NULL if we have no p_chan.
   */
  circuitmux_t *p_mux;
  /** Linked list of Exit streams associated with this circuit. */
  edge_connection_t *n_streams;
  /** Linked list of Exit streams associated with this circuit that are
   * still being resolved. */
  edge_connection_t *resolving_streams;
  /** The cipher used by intermediate hops for cells heading toward the
   * OP. */
  crypto_cipher_t *p_crypto;
  /** The cipher used by intermediate hops for cells heading away from
   * the OP. */
  crypto_cipher_t *n_crypto;

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

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

  struct or_circuit_rendinfo_s *rendinfo;

  /** Stores KH for the handshake. */
  char rend_circ_nonce[DIGEST_LEN];/* KH in tor-spec.txt */

  /** How many more relay_early cells can we send on this circuit, according
   * to the specification? */
  unsigned int remaining_relay_early_cells : 4;

  /** True iff this circuit was made with a CREATE_FAST cell. */
  unsigned int is_first_hop : 1;

  /** Number of cells that were removed from circuit queue; reset every
   * time when writing buffer stats to disk. */
  uint32_t processed_cells;

  /** Total time in milliseconds that cells spent in both app-ward and
   * exit-ward queues of this circuit; reset every time when writing
   * buffer stats to disk. */
  uint64_t total_cell_waiting_time;

  /** Maximum cell queue size for a middle relay; this is stored per circuit
   * so append_cell_to_circuit_queue() can adjust it if it changes.  If set
   * to zero, it is initialized to the default value.
   */
  uint32_t max_middle_cells;
} or_circuit_t;

typedef struct or_circuit_rendinfo_s {

#if REND_COOKIE_LEN != DIGEST_LEN
#error "The REND_TOKEN_LEN macro assumes REND_COOKIE_LEN == DIGEST_LEN"
#endif
#define REND_TOKEN_LEN DIGEST_LEN

  /** A hash of location-hidden service's PK if purpose is INTRO_POINT, or a
   * rendezvous cookie if purpose is REND_POINT_WAITING. Filled with zeroes
   * otherwise.
   */
  char rend_token[REND_TOKEN_LEN];

  /** True if this is a rendezvous point circuit; false if this is an
   * introduction point. */
  unsigned is_rend_circ;

} or_circuit_rendinfo_t;

/** Convert a circuit subtype to a circuit_t. */
#define TO_CIRCUIT(x)  (&((x)->base_))

/** Convert a circuit_t* to a pointer to the enclosing or_circuit_t.  Assert
 * if the cast is impossible. */
static or_circuit_t *TO_OR_CIRCUIT(circuit_t *);
/** Convert a circuit_t* to a pointer to the enclosing origin_circuit_t.
 * Assert if the cast is impossible. */
static origin_circuit_t *TO_ORIGIN_CIRCUIT(circuit_t *);

static INLINE or_circuit_t *TO_OR_CIRCUIT(circuit_t *x)
{
  tor_assert(x->magic == OR_CIRCUIT_MAGIC);
  return DOWNCAST(or_circuit_t, x);
}
static INLINE origin_circuit_t *TO_ORIGIN_CIRCUIT(circuit_t *x)
{
  tor_assert(x->magic == ORIGIN_CIRCUIT_MAGIC);
  return DOWNCAST(origin_circuit_t, x);
}

/** Bitfield type: things that we're willing to use invalid routers for. */
typedef enum invalid_router_usage_t {
  ALLOW_INVALID_ENTRY       =1,
  ALLOW_INVALID_EXIT        =2,
  ALLOW_INVALID_MIDDLE      =4,
  ALLOW_INVALID_RENDEZVOUS  =8,
  ALLOW_INVALID_INTRODUCTION=16,
} invalid_router_usage_t;

/* limits for TCP send and recv buffer size used for constrained sockets */
#define MIN_CONSTRAINED_TCP_BUFFER 2048
#define MAX_CONSTRAINED_TCP_BUFFER 262144  /* 256k */

/** @name Isolation flags

    Ways to isolate client streams

    @{
*/
/** Isolate based on destination port */
#define ISO_DESTPORT    (1u<<0)
/** Isolate based on destination address */
#define ISO_DESTADDR    (1u<<1)
/** Isolate based on SOCKS authentication */
#define ISO_SOCKSAUTH   (1u<<2)
/** Isolate based on client protocol choice */
#define ISO_CLIENTPROTO (1u<<3)
/** Isolate based on client address */
#define ISO_CLIENTADDR  (1u<<4)
/** Isolate based on session group (always on). */
#define ISO_SESSIONGRP  (1u<<5)
/** Isolate based on newnym epoch (always on). */
#define ISO_NYM_EPOCH   (1u<<6)
/** Isolate all streams (Internal only). */
#define ISO_STREAM      (1u<<7)
/**@}*/

/** Default isolation level for ports. */
#define ISO_DEFAULT (ISO_CLIENTADDR|ISO_SOCKSAUTH|ISO_SESSIONGRP|ISO_NYM_EPOCH)

/** Indicates that we haven't yet set a session group on a port_cfg_t. */
#define SESSION_GROUP_UNSET -1
/** Session group reserved for directory connections */
#define SESSION_GROUP_DIRCONN -2
/** Session group reserved for resolve requests launched by a controller */
#define SESSION_GROUP_CONTROL_RESOLVE -3
/** First automatically allocated session group number */
#define SESSION_GROUP_FIRST_AUTO -4

/** Configuration for a single port that we're listening on. */
typedef struct port_cfg_t {
  tor_addr_t addr; /**< The actual IP to listen on, if !is_unix_addr. */
  int port; /**< The configured port, or CFG_AUTO_PORT to tell Tor to pick its
             * own port. */
  uint8_t type; /**< One of CONN_TYPE_*_LISTENER */
  unsigned is_unix_addr : 1; /**< True iff this is an AF_UNIX address. */

  /* Client port types (socks, dns, trans, natd) only: */
  uint8_t isolation_flags; /**< Zero or more isolation flags */
  int session_group; /**< A session group, or -1 if this port is not in a
                      * session group. */
  /* Socks only: */
  /** When both no-auth and user/pass are advertised by a SOCKS client, select
   * no-auth. */
  unsigned int socks_prefer_no_auth : 1;

  /* Server port types (or, dir) only: */
  unsigned int no_advertise : 1;
  unsigned int no_listen : 1;
  unsigned int all_addrs : 1;
  unsigned int bind_ipv4_only : 1;
  unsigned int bind_ipv6_only : 1;

  /* Client port types only: */
  unsigned int ipv4_traffic : 1;
  unsigned int ipv6_traffic : 1;
  unsigned int prefer_ipv6 : 1;

  /** For a socks listener: should we cache IPv4/IPv6 DNS information that
   * exit nodes tell us?
   *
   * @{ */
  unsigned int cache_ipv4_answers : 1;
  unsigned int cache_ipv6_answers : 1;
  /** @} */
  /** For a socks listeners: if we find an answer in our client-side DNS cache,
   * should we use it?
   *
   * @{ */
  unsigned int use_cached_ipv4_answers : 1;
  unsigned int use_cached_ipv6_answers : 1;
  /** @} */
  /** For socks listeners: When we can automap an address to IPv4 or IPv6,
   * do we prefer IPv6? */
  unsigned int prefer_ipv6_virtaddr : 1;

  /* Unix sockets only: */
  /** Path for an AF_UNIX address */
  char unix_addr[FLEXIBLE_ARRAY_MEMBER];
} port_cfg_t;

/** Ordinary configuration line. */
#define CONFIG_LINE_NORMAL 0
/** Appends to previous configuration for the same option, even if we
 * would ordinary replace it. */
#define CONFIG_LINE_APPEND 1
/* Removes all previous configuration for an option. */
#define CONFIG_LINE_CLEAR 2

/** A linked list of lines in a config file. */
typedef struct config_line_t {
  char *key;
  char *value;
  struct config_line_t *next;
  /** What special treatment (if any) does this line require? */
  unsigned int command:2;
  /** If true, subsequent assignments to this linelist should replace
   * it, not extend it.  Set only on the first item in a linelist in an
   * or_options_t. */
  unsigned int fragile:1;
} config_line_t;

typedef struct routerset_t routerset_t;

/** A magic value for the (Socks|OR|...)Port options below, telling Tor
 * to pick its own port. */
#define CFG_AUTO_PORT 0xc4005e

/** 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, CMD_DUMP_CONFIG
  } command;
  char *command_arg; /**< Argument for command-line option. */

  config_line_t *Logs; /**< New-style list of configuration lines
                        * for logs */
  int LogTimeGranularity; /**< Log resolution in milliseconds. */

  int LogMessageDomains; /**< Boolean: Should we log the domain(s) in which
                          * each log message occurs? */

  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. */

  int DynamicDHGroups; /**< Dynamic generation of prime moduli for use in DH.*/

  routerset_t *ExitNodes; /**< Structure containing nicknames, digests,
                           * country codes and IP address patterns of ORs to
                           * consider as exits. */
  routerset_t *EntryNodes;/**< Structure containing nicknames, digests,
                           * country codes and IP address patterns of ORs to
                           * consider as entry points. */
  int StrictNodes; /**< Boolean: When none of our EntryNodes or ExitNodes
                    * are up, or we need to access a node in ExcludeNodes,
                    * do we just fail instead? */
  routerset_t *ExcludeNodes;/**< Structure containing nicknames, digests,
                             * country codes and IP address patterns of ORs
                             * not to use in circuits. But see StrictNodes
                             * above. */
  routerset_t *ExcludeExitNodes;/**< Structure containing nicknames, digests,
                                 * country codes and IP address patterns of
                                 * ORs not to consider as exits. */

  /** Union of ExcludeNodes and ExcludeExitNodes */
  routerset_t *ExcludeExitNodesUnion_;

  int DisableAllSwap; /**< Boolean: Attempt to call mlockall() on our
                       * process for all current and future memory. */

  /** List of "entry", "middle", "exit", "introduction", "rendezvous". */
  smartlist_t *AllowInvalidNodes;
  /** Bitmask; derived from AllowInvalidNodes. */
  invalid_router_usage_t AllowInvalid_;
  config_line_t *ExitPolicy; /**< Lists of exit policy components. */
  int ExitPolicyRejectPrivate; /**< Should we not exit to local addresses? */
  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 *SocksListenAddress;
  /** Addresses to bind for listening for transparent pf/netfilter
   * connections. */
  config_line_t *TransListenAddress;
  /** Addresses to bind for listening for transparent natd connections */
  config_line_t *NATDListenAddress;
  /** Addresses to bind for listening for SOCKS connections. */
  config_line_t *DNSListenAddress;
  /** Addresses to bind for listening for OR connections. */
  config_line_t *ORListenAddress;
  /** Addresses to bind for listening for directory connections. */
  config_line_t *DirListenAddress;
  /** Addresses to bind for listening for control connections. */
  config_line_t *ControlListenAddress;
  /** Local address to bind outbound sockets */
  config_line_t *OutboundBindAddress;
  /** IPv4 address derived from OutboundBindAddress. */
  tor_addr_t OutboundBindAddressIPv4_;
  /** IPv6 address derived from OutboundBindAddress. */
  tor_addr_t OutboundBindAddressIPv6_;
  /** 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 allow router descriptors with private IPs. */
  int DirAllowPrivateAddresses;
  /** Whether routers accept EXTEND cells to routers with private IPs. */
  int ExtendAllowPrivateAddresses;
  char *User; /**< Name of user to run Tor as. */
  char *Group; /**< Name of group to run Tor as. */
  config_line_t *ORPort_lines; /**< Ports to listen on for OR connections. */
  /** Ports to listen on for extended OR connections. */
  config_line_t *ExtORPort_lines;
  /** Ports to listen on for SOCKS connections. */
  config_line_t *SocksPort_lines;
  /** Ports to listen on for transparent pf/netfilter connections. */
  config_line_t *TransPort_lines;
  const char *TransProxyType; /**< What kind of transparent proxy
                               * implementation are we using? */
  /** Parsed value of TransProxyType. */
  enum {
    TPT_DEFAULT,
    TPT_PF_DIVERT,
    TPT_IPFW,
    TPT_TPROXY,
  } TransProxyType_parsed;
  config_line_t *NATDPort_lines; /**< Ports to listen on for transparent natd
                            * connections. */
  config_line_t *ControlPort_lines; /**< Ports to listen on for control
                               * connections. */
  config_line_t *ControlSocket; /**< List of Unix Domain Sockets to listen on
                                 * for control connections. */

  int ControlSocketsGroupWritable; /**< Boolean: Are control sockets g+rw? */
  /** Ports to listen on for directory connections. */
  config_line_t *DirPort_lines;
  config_line_t *DNSPort_lines; /**< Ports to listen on for DNS requests. */

  /* MaxMemInQueues value as input by the user. We clean this up to be
   * MaxMemInQueues. */
  uint64_t MaxMemInQueues_raw;
  uint64_t MaxMemInQueues;/**< If we have more memory than this allocated
                            * for queues and buffers, run the OOM handler */

  /** @name port booleans
   *
   * Derived booleans: True iff there is a non-listener port on an AF_INET or
   * AF_INET6 address of the given type configured in one of the _lines
   * options above.
   *
   * @{
   */
  unsigned int ORPort_set : 1;
  unsigned int SocksPort_set : 1;
  unsigned int TransPort_set : 1;
  unsigned int NATDPort_set : 1;
  unsigned int ControlPort_set : 1;
  unsigned int DirPort_set : 1;
  unsigned int DNSPort_set : 1;
  unsigned int ExtORPort_set : 1;
  /**@}*/

  int AssumeReachable; /**< Whether to publish our descriptor regardless. */
  int AuthoritativeDir; /**< Boolean: is this an authoritative directory? */
  int V3AuthoritativeDir; /**< Boolean: is this an authoritative directory
                           * for version 3 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 BridgeAuthoritativeDir; /**< Boolean: is this an authoritative directory
                               * that aggregates bridge descriptors? */

  /** If set on a bridge authority, it will answer requests on its dirport
   * for bridge statuses -- but only if the requests use this password. */
  char *BridgePassword;
  /** If BridgePassword is set, this is a SHA256 digest of the basic http
   * authenticator for it. Used so we can do a time-independent comparison. */
  char *BridgePassword_AuthDigest_;

  int UseBridges; /**< Boolean: should we start all circuits with a bridge? */
  config_line_t *Bridges; /**< List of bootstrap bridge addresses. */

  config_line_t *ClientTransportPlugin; /**< List of client
                                           transport plugins. */

  config_line_t *ServerTransportPlugin; /**< List of client
                                           transport plugins. */

  /** List of TCP/IP addresses that transports should listen at. */
  config_line_t *ServerTransportListenAddr;

  /** List of options that must be passed to pluggable transports. */
  config_line_t *ServerTransportOptions;

  int BridgeRelay; /**< Boolean: are we acting as a bridge relay? We make
                    * this explicit so we can change how we behave in the
                    * future. */

  /** Boolean: if we know the bridge's digest, should we get new
   * descriptors from the bridge authorities or from the bridge itself? */
  int UpdateBridgesFromAuthority;

  int AvoidDiskWrites; /**< Boolean: should we never cache things to disk?
                        * Not used yet. */
  int ClientOnly; /**< Boolean: should we never evolve into a server role? */
  /** To what authority types do we publish our descriptor? Choices are
   * "v1", "v2", "v3", "bridge", or "". */
  smartlist_t *PublishServerDescriptor;
  /** A bitfield of authority types, derived from PublishServerDescriptor. */
  dirinfo_type_t PublishServerDescriptor_;
  /** Boolean: do we publish hidden service descriptors to the HS auths? */
  int PublishHidServDescriptors;
  int FetchServerDescriptors; /**< Do we fetch server descriptors as normal? */
  int FetchHidServDescriptors; /**< and hidden service descriptors? */
  int HidServDirectoryV2; /**< Do we participate in the HS DHT? */

  int VoteOnHidServDirectoriesV2; /**< As a directory authority, vote on
                                   * assignment of the HSDir flag? */
  int MinUptimeHidServDirectoryV2; /**< As directory authority, accept hidden
                                    * service directories after what time? */

  int FetchUselessDescriptors; /**< Do we fetch non-running descriptors too? */
  int AllDirActionsPrivate; /**< Should every directory action be sent
                             * through a Tor circuit? */

  /** Run in 'tor2web mode'? (I.e. only make client connections to hidden
   * services, and use a single hop for all hidden-service-related
   * circuits.) */
  int Tor2webMode;

  /** Close hidden service client circuits immediately when they reach
   * the normal circuit-build timeout, even if they have already sent
   * an INTRODUCE1 cell on its way to the service. */
  int CloseHSClientCircuitsImmediatelyOnTimeout;

  /** Close hidden-service-side rendezvous circuits immediately when
   * they reach the normal circuit-build timeout. */
  int CloseHSServiceRendCircuitsImmediatelyOnTimeout;

  int ConnLimit; /**< Demanded minimum number of simultaneous connections. */
  int ConnLimit_; /**< Maximum allowed number of simultaneous connections. */
  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; /**< IP:ports our firewall allows. */
  config_line_t *ReachableORAddresses; /**< IP:ports for OR conns. */
  config_line_t *ReachableDirAddresses; /**< IP:ports for Dir conns. */

  int ConstrainedSockets; /**< Shrink xmit and recv socket buffers. */
  uint64_t ConstrainedSockSize; /**< Size of constrained buffers. */

  /** Whether we should drop exit streams from Tors that we don't know are
   * relays.  One of "0" (never refuse), "1" (always refuse), or "-1" (do
   * what the consensus says, defaulting to 'refuse' if the consensus says
   * nothing). */
  int RefuseUnknownExits;

  /** Application ports that require all nodes in circ to have sufficient
   * uptime. */
  smartlist_t *LongLivedPorts;
  /** Application ports that are likely to be unencrypted and
   * unauthenticated; we reject requests for them to prevent the
   * user from screwing up and leaking plaintext secrets to an
   * observer somewhere on the Internet. */
  smartlist_t *RejectPlaintextPorts;
  /** Related to RejectPlaintextPorts above, except this config option
   * controls whether we warn (in the log and via a controller status
   * event) every time a risky connection is attempted. */
  smartlist_t *WarnPlaintextPorts;
  /** 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 AutomapHostsOnResolve; /**< If true, when we get a resolve request for a
                              * hostname ending with one of the suffixes in
                              * <b>AutomapHostsSuffixes</b>, map it to a
                              * virtual address. */
  smartlist_t *AutomapHostsSuffixes; /**< List of suffixes for
                                      * <b>AutomapHostsOnResolve</b>. */
  int RendPostPeriod; /**< How often do we post each rendezvous service
                       * descriptor? Remember to publish them independently. */
  int KeepalivePeriod; /**< How often do we send padding cells to keep
                        * connections alive? */
  int SocksTimeout; /**< How long do we let a socks connection wait
                     * unattached before we fail it? */
  int LearnCircuitBuildTimeout; /**< If non-zero, we attempt to learn a value
                                 * for CircuitBuildTimeout based on timeout
                                 * history */
  int CircuitBuildTimeout; /**< Cull non-open circuits that were born at
                            * least this many seconds ago. Used until
                            * adaptive algorithm learns a new value. */
  int CircuitIdleTimeout; /**< Cull open clean circuits that were born
                           * at least this many seconds ago. */
  int CircuitStreamTimeout; /**< If non-zero, detach streams from circuits
                             * and try a new circuit if the stream has been
                             * waiting for this many seconds. If zero, use
                             * our default internal timeout schedule. */
  int MaxOnionQueueDelay; /**<DOCDOC*/
  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. */
  int PredictedPortsRelevanceTime; /** How long after we've requested a
                                    * connection for a given port, do we want
                                    * to continue to pick exits that support
                                    * that port?  */
  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? */
  uint64_t RelayBandwidthRate; /**< How much bandwidth, on average, are we
                                 * willing to use for all relayed conns? */
  uint64_t RelayBandwidthBurst; /**< How much bandwidth, at maximum, will we
                                 * use in a second for all relayed conns? */
  uint64_t PerConnBWRate; /**< Long-term bw on a single TLS conn, if set. */
  uint64_t PerConnBWBurst; /**< Allowed burst on a single TLS conn, if set. */
  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. */
  config_line_t *HidServAuth; /**< List of configuration lines for client-side
                               * authorizations for hidden services */
  char *ContactInfo; /**< Contact info to be published in the directory. */

  int HeartbeatPeriod; /**< Log heartbeat messages after this many seconds
                        * have passed. */

  char *HTTPProxy; /**< hostname[:port] to use as http proxy, if any. */
  tor_addr_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. */
  tor_addr_t HTTPSProxyAddr; /**< Parsed addr for https proxy, if any. */
  uint16_t HTTPSProxyPort; /**< Parsed port for https proxy, if any. */
  char *HTTPSProxyAuthenticator; /**< username:password string, if any. */

  char *Socks4Proxy; /**< hostname:port to use as a SOCKS4 proxy, if any. */
  tor_addr_t Socks4ProxyAddr; /**< Derived from Socks4Proxy. */
  uint16_t Socks4ProxyPort; /**< Derived from Socks4Proxy. */

  char *Socks5Proxy; /**< hostname:port to use as a SOCKS5 proxy, if any. */
  tor_addr_t Socks5ProxyAddr; /**< Derived from Sock5Proxy. */
  uint16_t Socks5ProxyPort; /**< Derived from Socks5Proxy. */
  char *Socks5ProxyUsername; /**< Username for SOCKS5 authentication, if any */
  char *Socks5ProxyPassword; /**< Password for SOCKS5 authentication, if any */

  /** List of configuration lines for replacement directory authorities.
   * If you just want to replace one class of authority at a time,
   * use the "Alternate*Authority" options below instead. */
  config_line_t *DirAuthorities;

  /** List of fallback directory servers */
  config_line_t *FallbackDir;

  /** Weight to apply to all directory authority rates if considering them
   * along with fallbackdirs */
  double DirAuthorityFallbackRate;

  /** If set, use these main (currently v3) directory authorities and
   * not the default ones. */
  config_line_t *AlternateDirAuthority;

  /** If set, use these bridge authorities and not the default one. */
  config_line_t *AlternateBridgeAuthority;

  char *MyFamily; /**< Declared family for this OR. */
  config_line_t *NodeFamilies; /**< List of config lines for
                                * node families */
  smartlist_t *NodeFamilySets; /**< List of parsed NodeFamilies values. */
  config_line_t *AuthDirBadDir; /**< Address policy for descriptors to
                                 * mark as bad dir mirrors. */
  config_line_t *AuthDirBadExit; /**< Address policy for descriptors to
                                  * mark as bad exits. */
  config_line_t *AuthDirReject; /**< Address policy for descriptors to
                                 * reject. */
  config_line_t *AuthDirInvalid; /**< Address policy for descriptors to
                                  * never mark as valid. */
  /** @name AuthDir...CC
   *
   * Lists of country codes to mark as BadDir, BadExit, or Invalid, or to
   * reject entirely.
   *
   * @{
   */
  smartlist_t *AuthDirBadDirCCs;
  smartlist_t *AuthDirBadExitCCs;
  smartlist_t *AuthDirInvalidCCs;
  smartlist_t *AuthDirRejectCCs;
  /**@}*/

  int AuthDirListBadDirs; /**< True iff we should list bad dirs,
                           * and vote for all other dir mirrors as good. */
  int AuthDirListBadExits; /**< True iff we should list bad exits,
                            * and vote for all other exits as good. */
  int AuthDirRejectUnlisted; /**< Boolean: do we reject all routers that
                              * aren't named in our fingerprint file? */
  int AuthDirMaxServersPerAddr; /**< Do not permit more than this
                                 * number of servers per IP address. */
  int AuthDirMaxServersPerAuthAddr; /**< Do not permit more than this
                                     * number of servers per IP address shared
                                     * with an authority. */
  int AuthDirHasIPv6Connectivity; /**< Boolean: are we on IPv6?  */

  /** If non-zero, always vote the Fast flag for any relay advertising
   * this amount of capacity or more. */
  uint64_t AuthDirFastGuarantee;

  /** If non-zero, this advertised capacity or more is always sufficient
   * to satisfy the bandwidth requirement for the Guard flag. */
  uint64_t AuthDirGuardBWGuarantee;

  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." */

  /** Base64-encoded hash of accepted passwords for the control system. */
  config_line_t *HashedControlPassword;
  /** As HashedControlPassword, but not saved. */
  config_line_t *HashedControlSessionPassword;

  int CookieAuthentication; /**< Boolean: do we enable cookie-based auth for
                             * the control system? */
  char *CookieAuthFile; /**< Filesystem location of a ControlPort
                         *   authentication cookie. */
  char *ExtORPortCookieAuthFile; /**< Filesystem location of Extended
                                 *   ORPort authentication cookie. */
  int CookieAuthFileGroupReadable; /**< Boolean: Is the CookieAuthFile g+r? */
  int LeaveStreamsUnattached; /**< Boolean: Does Tor attach new streams to
                          * circuits itself (0), or does it expect a controller
                          * to cope? (1) */
  int DisablePredictedCircuits; /**< Boolean: does Tor preemptively
                                 * make circuits in the background (0),
                                 * or not (1)? */

  /** Process specifier for a controller that ‘owns’ this Tor
   * instance.  Tor will terminate if its owning controller does. */
  char *OwningControllerProcess;

  int ShutdownWaitLength; /**< When we get a SIGINT and we're a server, how
                           * long do we wait before exiting? */
  char *SafeLogging; /**< Contains "relay", "1", "0" (meaning no scrubbing). */

  /* Derived from SafeLogging */
  enum {
    SAFELOG_SCRUB_ALL, SAFELOG_SCRUB_RELAY, SAFELOG_SCRUB_NONE
  } SafeLogging_;

  int Sandbox; /**< Boolean: should sandboxing be enabled? */
  int SafeSocks; /**< Boolean: should we outright refuse application
                  * connections that use socks4 or socks5-with-local-dns? */
#define LOG_PROTOCOL_WARN (get_options()->ProtocolWarnings ? \
                           LOG_WARN : LOG_INFO)
  int ProtocolWarnings; /**< Boolean: when other parties screw up the Tor
                         * protocol, is it a warn or an info in our logs? */
  int TestSocks; /**< Boolean: when we get a socks connection, do we loudly
                  * log whether it was DNS-leaking or not? */
  int HardwareAccel; /**< Boolean: Should we enable OpenSSL hardware
                      * acceleration where available? */
  /** Token Bucket Refill resolution in milliseconds. */
  int TokenBucketRefillInterval;
  char *AccelName; /**< Optional hardware acceleration engine name. */
  char *AccelDir; /**< Optional hardware acceleration engine search dir. */
  int UseEntryGuards; /**< Boolean: Do we try to enter from a smallish number
                       * of fixed nodes? */
  int NumEntryGuards; /**< How many entry guards do we try to establish? */
  int UseEntryGuardsAsDirGuards; /** Boolean: Do we try to get directory info
                                  * from a smallish number of fixed nodes? */
  int NumDirectoryGuards; /**< How many dir guards do we try to establish?
                           * If 0, use value from NumEntryGuards. */
  int RephistTrackTime; /**< How many seconds do we keep rephist info? */
  int FastFirstHopPK; /**< If Tor believes it is safe, should we save a third
                       * of our PK time by sending CREATE_FAST cells? */
  /** Should we always fetch our dir info on the mirror schedule (which
   * means directly from the authorities) no matter our other config? */
  int FetchDirInfoEarly;

  /** Should we fetch our dir info at the start of the consensus period? */
  int FetchDirInfoExtraEarly;

  char *VirtualAddrNetworkIPv4; /**< Address and mask to hand out for virtual
                                 * MAPADDRESS requests for IPv4 addresses */
  char *VirtualAddrNetworkIPv6; /**< Address and mask to hand out for virtual
                                 * MAPADDRESS requests for IPv6 addresses */
  int ServerDNSSearchDomains; /**< Boolean: If set, we don't force exit
                      * addresses to be FQDNs, but rather search for them in
                      * the local domains. */
  int ServerDNSDetectHijacking; /**< Boolean: If true, check for DNS failure
                                 * hijacking. */
  int ServerDNSRandomizeCase; /**< Boolean: Use the 0x20-hack to prevent
                               * DNS poisoning attacks. */
  char *ServerDNSResolvConfFile; /**< If provided, we configure our internal
                     * resolver from the file here rather than from
                     * /etc/resolv.conf (Unix) or the registry (Windows). */
  char *DirPortFrontPage; /**< This is a full path to a file with an html
                    disclaimer. This allows a server administrator to show
                    that they're running Tor and anyone visiting their server
                    will know this without any specialized knowledge. */
  int DisableDebuggerAttachment; /**< Currently Linux only specific attempt to
                                      disable ptrace; needs BSD testing. */
  /** Boolean: if set, we start even if our resolv.conf file is missing
   * or broken. */
  int ServerDNSAllowBrokenConfig;
  /** Boolean: if set, then even connections to private addresses will get
   * rate-limited. */
  int CountPrivateBandwidth;
  smartlist_t *ServerDNSTestAddresses; /**< A list of addresses that definitely
                                        * should be resolvable. Used for
                                        * testing our DNS server. */
  int EnforceDistinctSubnets; /**< If true, don't allow multiple routers in the
                               * same network zone in the same circuit. */
  int TunnelDirConns; /**< If true, use BEGIN_DIR rather than BEGIN when
                       * possible. */
  int PreferTunneledDirConns; /**< If true, avoid dirservers that don't
                               * support BEGIN_DIR, when possible. */
  int PortForwarding; /**< If true, use NAT-PMP or UPnP to automatically
                       * forward the DirPort and ORPort on the NAT device */
  char *PortForwardingHelper; /** < Filename or full path of the port
                                  forwarding helper executable */
  int AllowNonRFC953Hostnames; /**< If true, we allow connections to hostnames
                                * with weird characters. */
  /** If true, we try resolving hostnames with weird characters. */
  int ServerDNSAllowNonRFC953Hostnames;

  /** If true, we try to download extra-info documents (and we serve them,
   * if we are a cache).  For authorities, this is always true. */
  int DownloadExtraInfo;

  /** If true, and we are acting as a relay, allow exit circuits even when
   * we are the first hop of a circuit. */
  int AllowSingleHopExits;
  /** If true, don't allow relays with AllowSingleHopExits=1 to be used in
   * circuits that we build. */
  int ExcludeSingleHopRelays;
  /** If true, and the controller tells us to use a one-hop circuit, and the
   * exit allows it, we use it. */
  int AllowSingleHopCircuits;

  /** If true, we convert "www.google.com.foo.exit" addresses on the
   * socks/trans/natd ports into "www.google.com" addresses that
   * exit from the node "foo". Disabled by default since attacking
   * websites and exit relays can use it to manipulate your path
   * selection. */
  int AllowDotExit;

  /** If true, we will warn if a user gives us only an IP address
   * instead of a hostname. */
  int WarnUnsafeSocks;

  /** If true, the user wants us to collect statistics on clients
   * requesting network statuses from us as directory. */
  int DirReqStatistics;

  /** If true, the user wants us to collect statistics on port usage. */
  int ExitPortStatistics;

  /** If true, the user wants us to collect connection statistics. */
  int ConnDirectionStatistics;

  /** If true, the user wants us to collect cell statistics. */
  int CellStatistics;

  /** If true, the user wants us to collect statistics as entry node. */
  int EntryStatistics;

  /** If true, include statistics file contents in extra-info documents. */
  int ExtraInfoStatistics;

  /** If true, do not believe anybody who tells us that a domain resolves
   * to an internal address, or that an internal address has a PTR mapping.
   * Helps avoid some cross-site attacks. */
  int ClientDNSRejectInternalAddresses;

  /** If true, do not accept any requests to connect to internal addresses
   * over randomly chosen exits. */
  int ClientRejectInternalAddresses;

  /** If true, clients may connect over IPv6. XXX we don't really
      enforce this -- clients _may_ set up outgoing IPv6 connections
      even when this option is not set. */
  int ClientUseIPv6;
  /** If true, prefer an IPv6 OR port over an IPv4 one. */
  int ClientPreferIPv6ORPort;

  /** The length of time that we think a consensus should be fresh. */
  int V3AuthVotingInterval;
  /** The length of time we think it will take to distribute votes. */
  int V3AuthVoteDelay;
  /** The length of time we think it will take to distribute signatures. */
  int V3AuthDistDelay;
  /** The number of intervals we think a consensus should be valid. */
  int V3AuthNIntervalsValid;

  /** Should advertise and sign consensuses with a legacy key, for key
   * migration purposes? */
  int V3AuthUseLegacyKey;

  /** Location of bandwidth measurement file */
  char *V3BandwidthsFile;

  /** Authority only: key=value pairs that we add to our networkstatus
   * consensus vote on the 'params' line. */
  char *ConsensusParams;

  /** Authority only: minimum number of measured bandwidths we must see
   * before we only beliee measured bandwidths to assign flags. */
  int MinMeasuredBWsForAuthToIgnoreAdvertised;

  /** The length of time that we think an initial consensus should be fresh.
   * Only altered on testing networks. */
  int TestingV3AuthInitialVotingInterval;

  /** The length of time we think it will take to distribute initial votes.
   * Only altered on testing networks. */
  int TestingV3AuthInitialVoteDelay;

  /** The length of time we think it will take to distribute initial
   * signatures.  Only altered on testing networks.*/
  int TestingV3AuthInitialDistDelay;

  /** Offset in seconds added to the starting time for consensus
      voting. Only altered on testing networks. */
  int TestingV3AuthVotingStartOffset;

  /** If an authority has been around for less than this amount of time, it
   * does not believe its reachability information is accurate.  Only
   * altered on testing networks. */
  int TestingAuthDirTimeToLearnReachability;

  /** Clients don't download any descriptor this recent, since it will
   * probably not have propagated to enough caches.  Only altered on testing
   * networks. */
  int TestingEstimatedDescriptorPropagationTime;

  /** Schedule for when servers should download things in general.  Only
   * altered on testing networks. */
  smartlist_t *TestingServerDownloadSchedule;

  /** Schedule for when clients should download things in general.  Only
   * altered on testing networks. */
  smartlist_t *TestingClientDownloadSchedule;

  /** Schedule for when servers should download consensuses.  Only altered
   * on testing networks. */
  smartlist_t *TestingServerConsensusDownloadSchedule;

  /** Schedule for when clients should download consensuses.  Only altered
   * on testing networks. */
  smartlist_t *TestingClientConsensusDownloadSchedule;

  /** Schedule for when clients should download bridge descriptors.  Only
   * altered on testing networks. */
  smartlist_t *TestingBridgeDownloadSchedule;

  /** When directory clients have only a few descriptors to request, they
   * batch them until they have more, or until this amount of time has
   * passed.  Only altered on testing networks. */
  int TestingClientMaxIntervalWithoutRequest;

  /** How long do we let a directory connection stall before expiring
   * it?  Only altered on testing networks. */
  int TestingDirConnectionMaxStall;

  /** How many times will we try to fetch a consensus before we give
   * up?  Only altered on testing networks. */
  int TestingConsensusMaxDownloadTries;

  /** How many times will we try to download a router's descriptor before
   * giving up?  Only altered on testing networks. */
  int TestingDescriptorMaxDownloadTries;

  /** How many times will we try to download a microdescriptor before
   * giving up?  Only altered on testing networks. */
  int TestingMicrodescMaxDownloadTries;

  /** How many times will we try to fetch a certificate before giving
   * up?  Only altered on testing networks. */
  int TestingCertMaxDownloadTries;

  /** If true, we take part in a testing network. Change the defaults of a
   * couple of other configuration options and allow to change the values
   * of certain configuration options. */
  int TestingTorNetwork;

  /** Minimum value for the Exit flag threshold on testing networks. */
  uint64_t TestingMinExitFlagThreshold;

  /** Minimum value for the Fast flag threshold on testing networks. */
  uint64_t TestingMinFastFlagThreshold;

  /** Relays in a testing network which should be voted Guard
   * regardless of uptime and bandwidth. */
  routerset_t *TestingDirAuthVoteGuard;

  /** Enable CONN_BW events.  Only altered on testing networks. */
  int TestingEnableConnBwEvent;

  /** Enable CELL_STATS events.  Only altered on testing networks. */
  int TestingEnableCellStatsEvent;

  /** Enable TB_EMPTY events.  Only altered on testing networks. */
  int TestingEnableTbEmptyEvent;

  /** If true, and we have GeoIP data, and we're a bridge, keep a per-country
   * count of how many client addresses have contacted us so that we can help
   * the bridge authority guess which countries have blocked access to us. */
  int BridgeRecordUsageByCountry;

  /** Optionally, IPv4 and IPv6 GeoIP data. */
  char *GeoIPFile;
  char *GeoIPv6File;

  /** Autobool: if auto, then any attempt to Exclude{Exit,}Nodes a particular
   * country code will exclude all nodes in ?? and A1.  If true, all nodes in
   * ?? and A1 are excluded. Has no effect if we don't know any GeoIP data. */
  int GeoIPExcludeUnknown;

  /** If true, SIGHUP should reload the torrc.  Sometimes controllers want
   * to make this false. */
  int ReloadTorrcOnSIGHUP;

  /* The main parameter for picking circuits within a connection.
   *
   * If this value is positive, when picking a cell to relay on a connection,
   * we always relay from the circuit whose weighted cell count is lowest.
   * Cells are weighted exponentially such that if one cell is sent
   * 'CircuitPriorityHalflife' seconds before another, it counts for half as
   * much.
   *
   * If this value is zero, we're disabling the cell-EWMA algorithm.
   *
   * If this value is negative, we're using the default approach
   * according to either Tor or a parameter set in the consensus.
   */
  double CircuitPriorityHalflife;

  /** If true, do not enable IOCP on windows with bufferevents, even if
   * we think we could. */
  int DisableIOCP;
  /** For testing only: will go away eventually. */
  int UseFilteringSSLBufferevents;

  /** Set to true if the TestingTorNetwork configuration option is set.
   * This is used so that options_validate() has a chance to realize that
   * the defaults have changed. */
  int UsingTestNetworkDefaults_;

  /** If 1, we try to use microdescriptors to build circuits.  If 0, we don't.
   * If -1, Tor decides. */
  int UseMicrodescriptors;

  /** File where we should write the ControlPort. */
  char *ControlPortWriteToFile;
  /** Should that file be group-readable? */
  int ControlPortFileGroupReadable;

#define MAX_MAX_CLIENT_CIRCUITS_PENDING 1024
  /** Maximum number of non-open general-purpose origin circuits to allow at
   * once. */
  int MaxClientCircuitsPending;

  /** If 1, we always send optimistic data when it's supported.  If 0, we
   * never use it.  If -1, we do what the consensus says. */
  int OptimisticData;

  /** If 1, and we are using IOCP, we set the kernel socket SNDBUF and RCVBUF
   * to 0 to try to save kernel memory and avoid the dread "Out of buffers"
   * issue. */
  int UserspaceIOCPBuffers;

  /** If 1, we accept and launch no external network connections, except on
   * control ports. */
  int DisableNetwork;

  /**
   * Parameters for path-bias detection.
   * @{
   * These options override the default behavior of Tor's (**currently
   * experimental**) path bias detection algorithm. To try to find broken or
   * misbehaving guard nodes, Tor looks for nodes where more than a certain
   * fraction of circuits through that guard fail to get built.
   *
   * The PathBiasCircThreshold option controls how many circuits we need to
   * build through a guard before we make these checks.  The
   * PathBiasNoticeRate, PathBiasWarnRate and PathBiasExtremeRate options
   * control what fraction of circuits must succeed through a guard so we
   * won't write log messages.  If less than PathBiasExtremeRate circuits
   * succeed *and* PathBiasDropGuards is set to 1, we disable use of that
   * guard.
   *
   * When we have seen more than PathBiasScaleThreshold circuits through a
   * guard, we scale our observations by 0.5 (governed by the consensus) so
   * that new observations don't get swamped by old ones.
   *
   * By default, or if a negative value is provided for one of these options,
   * Tor uses reasonable defaults from the networkstatus consensus document.
   * If no defaults are available there, these options default to 150, .70,
   * .50, .30, 0, and 300 respectively.
   */
  int PathBiasCircThreshold;
  double PathBiasNoticeRate;
  double PathBiasWarnRate;
  double PathBiasExtremeRate;
  int PathBiasDropGuards;
  int PathBiasScaleThreshold;
  /** @} */

  /**
   * Parameters for path-bias use detection
   * @{
   * Similar to the above options, these options override the default behavior
   * of Tor's (**currently experimental**) path use bias detection algorithm.
   *
   * Where as the path bias parameters govern thresholds for successfully
   * building circuits, these four path use bias parameters govern thresholds
   * only for circuit usage. Circuits which receive no stream usage are not
   * counted by this detection algorithm. A used circuit is considered
   * successful if it is capable of carrying streams or otherwise receiving
   * well-formed responses to RELAY cells.
   *
   * By default, or if a negative value is provided for one of these options,
   * Tor uses reasonable defaults from the networkstatus consensus document.
   * If no defaults are available there, these options default to 20, .80,
   * .60, and 100, respectively.
   */
  int PathBiasUseThreshold;
  double PathBiasNoticeUseRate;
  double PathBiasExtremeUseRate;
  int PathBiasScaleUseThreshold;
  /** @} */

  int IPv6Exit; /**< Do we support exiting to IPv6 addresses? */

  char *TLSECGroup; /**< One of "P256", "P224", or nil for auto */

  /** Autobool: should we use the ntor handshake if we can? */
  int UseNTorHandshake;

  /** Fraction: */
  double PathsNeededToBuildCircuits;

  /** What expiry time shall we place on our SSL certs? "0" means we
   * should guess a suitable value. */
  int SSLKeyLifetime;

  /** How long (seconds) do we keep a guard before picking a new one? */
  int GuardLifetime;

  /** Should we send the timestamps that pre-023 hidden services want? */
  int Support022HiddenServices;
} or_options_t;

/** Persistent state for an onion router, as saved to disk. */
typedef struct {
  uint32_t magic_;
  /** The time at which we next plan to write the state to the disk.  Equal to
   * TIME_MAX if there are no savable changes, 0 if there are changes that
   * should be saved right away. */
  time_t next_write;

  /** When was the state last written to disk? */
  time_t LastWritten;

  /** Fields for accounting bandwidth use. */
  time_t AccountingIntervalStart;
  uint64_t AccountingBytesReadInInterval;
  uint64_t AccountingBytesWrittenInInterval;
  int AccountingSecondsActive;
  int AccountingSecondsToReachSoftLimit;
  time_t AccountingSoftLimitHitAt;
  uint64_t AccountingBytesAtSoftLimit;
  uint64_t AccountingExpectedUsage;

  /** A list of Entry Guard-related configuration lines. */
  config_line_t *EntryGuards;

  config_line_t *TransportProxies;

  /** These fields hold information on the history of bandwidth usage for
   * servers.  The "Ends" fields hold the time when we last updated the
   * bandwidth usage. The "Interval" fields hold the granularity, in seconds,
   * of the entries of Values.  The "Values" lists hold decimal string
   * representations of the number of bytes read or written in each
   * interval. The "Maxima" list holds decimal strings describing the highest
   * rate achieved during the interval.
   */
  time_t      BWHistoryReadEnds;
  int         BWHistoryReadInterval;
  smartlist_t *BWHistoryReadValues;
  smartlist_t *BWHistoryReadMaxima;
  time_t      BWHistoryWriteEnds;
  int         BWHistoryWriteInterval;
  smartlist_t *BWHistoryWriteValues;
  smartlist_t *BWHistoryWriteMaxima;
  time_t      BWHistoryDirReadEnds;
  int         BWHistoryDirReadInterval;
  smartlist_t *BWHistoryDirReadValues;
  smartlist_t *BWHistoryDirReadMaxima;
  time_t      BWHistoryDirWriteEnds;
  int         BWHistoryDirWriteInterval;
  smartlist_t *BWHistoryDirWriteValues;
  smartlist_t *BWHistoryDirWriteMaxima;

  /** Build time histogram */
  config_line_t * BuildtimeHistogram;
  unsigned int TotalBuildTimes;
  unsigned int CircuitBuildAbandonedCount;

  /** What version of Tor wrote this state file? */
  char *TorVersion;

  /** Holds any unrecognized values we found in the state file, in the order
   * in which we found them. */
  config_line_t *ExtraLines;

  /** When did we last rotate our onion key?  "0" for 'no idea'. */
  time_t LastRotatedOnionKey;
} or_state_t;

/** Change the next_write time of <b>state</b> to <b>when</b>, unless the
 * state is already scheduled to be written to disk earlier than <b>when</b>.
 */
static INLINE void or_state_mark_dirty(or_state_t *state, time_t when)
{
  if (state->next_write > when)
    state->next_write = when;
}

#define MAX_SOCKS_REPLY_LEN 1024
#define MAX_SOCKS_ADDR_LEN 256
#define SOCKS_NO_AUTH 0x00
#define SOCKS_USER_PASS 0x02

/** Please open a TCP connection to this addr:port. */
#define SOCKS_COMMAND_CONNECT       0x01
/** Please turn this FQDN into an IP address, privately. */
#define SOCKS_COMMAND_RESOLVE       0xF0
/** Please turn this IP address into an FQDN, privately. */
#define SOCKS_COMMAND_RESOLVE_PTR   0xF1

#define SOCKS_COMMAND_IS_CONNECT(c) ((c)==SOCKS_COMMAND_CONNECT)
#define SOCKS_COMMAND_IS_RESOLVE(c) ((c)==SOCKS_COMMAND_RESOLVE || \
                                     (c)==SOCKS_COMMAND_RESOLVE_PTR)

/** State of a SOCKS request from a user to an OP.  Also used to encode other
 * information for non-socks user request (such as those on TransPort and
 * DNSPort) */
struct socks_request_t {
  /** Which version of SOCKS did the client use? One of "0, 4, 5" -- where
   * 0 means that no socks handshake ever took place, and this is just a
   * stub connection (e.g. see connection_ap_make_link()). */
  uint8_t socks_version;
  /** If using socks5 authentication, which authentication type did we
   * negotiate?  currently we support 0 (no authentication) and 2
   * (username/password). */
  uint8_t auth_type;
  /** What is this stream's goal? One of the SOCKS_COMMAND_* values */
  uint8_t command;
  /** Which kind of listener created this stream? */
  uint8_t listener_type;
  size_t replylen; /**< Length of <b>reply</b>. */
  uint8_t 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.
                                    */
  char address[MAX_SOCKS_ADDR_LEN]; /**< What address did the client ask to
                                       connect to/resolve? */
  uint16_t port; /**< What port did the client ask to connect to? */
  unsigned int has_finished : 1; /**< Has the SOCKS handshake finished? Used to
                              * make sure we send back a socks reply for
                              * every connection. */
  unsigned int got_auth : 1; /**< Have we received any authentication data? */
  /** If this is set, we will choose "no authentication" instead of
   * "username/password" authentication if both are offered. Used as input to
   * parse_socks. */
  unsigned int socks_prefer_no_auth : 1;

  /** Number of bytes in username; 0 if username is NULL */
  size_t usernamelen;
  /** Number of bytes in password; 0 if password is NULL */
  uint8_t passwordlen;
  /** The negotiated username value if any (for socks5), or the entire
   * authentication string (for socks4).  This value is NOT nul-terminated;
   * see usernamelen for its length. */
  char *username;
  /** The negotiated password value if any (for socks5). This value is NOT
   * nul-terminated; see passwordlen for its length. */
  char *password;
};

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

/** How many hops does a general-purpose circuit have by default? */
#define DEFAULT_ROUTE_LEN 3

/* Circuit Build Timeout "public" structures. */

/** Precision multiplier for the Bw weights */
#define BW_WEIGHT_SCALE   10000
#define BW_MIN_WEIGHT_SCALE 1
#define BW_MAX_WEIGHT_SCALE INT32_MAX

/** Total size of the circuit timeout history to accumulate.
 * 1000 is approx 2.5 days worth of continual-use circuits. */
#define CBT_NCIRCUITS_TO_OBSERVE 1000

/** Width of the histogram bins in milliseconds */
#define CBT_BIN_WIDTH ((build_time_t)50)

/** Number of modes to use in the weighted-avg computation of Xm */
#define CBT_DEFAULT_NUM_XM_MODES 3
#define CBT_MIN_NUM_XM_MODES 1
#define CBT_MAX_NUM_XM_MODES 20

/** A build_time_t is milliseconds */
typedef uint32_t build_time_t;

/**
 * CBT_BUILD_ABANDONED is our flag value to represent a force-closed
 * circuit (Aka a 'right-censored' pareto value).
 */
#define CBT_BUILD_ABANDONED ((build_time_t)(INT32_MAX-1))
#define CBT_BUILD_TIME_MAX ((build_time_t)(INT32_MAX))

/** Save state every 10 circuits */
#define CBT_SAVE_STATE_EVERY 10

/* Circuit build times consensus parameters */

/**
 * How long to wait before actually closing circuits that take too long to
 * build in terms of CDF quantile.
 */
#define CBT_DEFAULT_CLOSE_QUANTILE 95
#define CBT_MIN_CLOSE_QUANTILE CBT_MIN_QUANTILE_CUTOFF
#define CBT_MAX_CLOSE_QUANTILE CBT_MAX_QUANTILE_CUTOFF

/**
 * How many circuits count as recent when considering if the
 * connection has gone gimpy or changed.
 */
#define CBT_DEFAULT_RECENT_CIRCUITS 20
#define CBT_MIN_RECENT_CIRCUITS 3
#define CBT_MAX_RECENT_CIRCUITS 1000

/**
 * Maximum count of timeouts that finish the first hop in the past
 * RECENT_CIRCUITS before calculating a new timeout.
 *
 * This tells us whether to abandon timeout history and set
 * the timeout back to whatever circuit_build_times_get_initial_timeout()
 * gives us.
 */
#define CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT (CBT_DEFAULT_RECENT_CIRCUITS*9/10)
#define CBT_MIN_MAX_RECENT_TIMEOUT_COUNT 3
#define CBT_MAX_MAX_RECENT_TIMEOUT_COUNT 10000

/** Minimum circuits before estimating a timeout */
#define CBT_DEFAULT_MIN_CIRCUITS_TO_OBSERVE 100
#define CBT_MIN_MIN_CIRCUITS_TO_OBSERVE 1
#define CBT_MAX_MIN_CIRCUITS_TO_OBSERVE 10000

/** Cutoff percentile on the CDF for our timeout estimation. */
#define CBT_DEFAULT_QUANTILE_CUTOFF 80
#define CBT_MIN_QUANTILE_CUTOFF 10
#define CBT_MAX_QUANTILE_CUTOFF 99
double circuit_build_times_quantile_cutoff(void);

/** How often in seconds should we build a test circuit */
#define CBT_DEFAULT_TEST_FREQUENCY 60
#define CBT_MIN_TEST_FREQUENCY 1
#define CBT_MAX_TEST_FREQUENCY INT32_MAX

/** Lowest allowable value for CircuitBuildTimeout in milliseconds */
#define CBT_DEFAULT_TIMEOUT_MIN_VALUE (1500)
#define CBT_MIN_TIMEOUT_MIN_VALUE 500
#define CBT_MAX_TIMEOUT_MIN_VALUE INT32_MAX

/** Initial circuit build timeout in milliseconds */
#define CBT_DEFAULT_TIMEOUT_INITIAL_VALUE (60*1000)
#define CBT_MIN_TIMEOUT_INITIAL_VALUE CBT_MIN_TIMEOUT_MIN_VALUE
#define CBT_MAX_TIMEOUT_INITIAL_VALUE INT32_MAX
int32_t circuit_build_times_initial_timeout(void);

#if CBT_DEFAULT_MAX_RECENT_TIMEOUT_COUNT < CBT_MIN_MAX_RECENT_TIMEOUT_COUNT
#error "RECENT_CIRCUITS is set too low."
#endif

/** Information about the state of our local network connection */
typedef struct {
  /** The timestamp we last completed a TLS handshake or received a cell */
  time_t network_last_live;
  /** If the network is not live, how many timeouts has this caused? */
  int nonlive_timeouts;
  /** Circular array of circuits that have made it to the first hop. Slot is
   * 1 if circuit timed out, 0 if circuit succeeded */
  int8_t *timeouts_after_firsthop;
  /** Number of elements allocated for the above array */
  int num_recent_circs;
  /** Index into circular array. */
  int after_firsthop_idx;
} network_liveness_t;

typedef struct circuit_build_times_s circuit_build_times_t;

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

/** An error from options_trial_assign() or options_init_from_string(). */
typedef enum setopt_err_t {
  SETOPT_OK = 0,
  SETOPT_ERR_MISC = -1,
  SETOPT_ERR_PARSE = -2,
  SETOPT_ERR_TRANSITION = -3,
  SETOPT_ERR_SETTING = -4,
} setopt_err_t;

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

/** Enumerates possible origins of a client-side address mapping. */
typedef enum {
  /** We're remapping this address because the controller told us to. */
  ADDRMAPSRC_CONTROLLER,
  /** We're remapping this address because of an AutomapHostsOnResolve
   * configuration. */
  ADDRMAPSRC_AUTOMAP,
  /** We're remapping this address because our configuration (via torrc, the
   * command line, or a SETCONF command) told us to. */
  ADDRMAPSRC_TORRC,
  /** We're remapping this address because we have TrackHostExit configured,
   * and we want to remember to use the same exit next time. */
  ADDRMAPSRC_TRACKEXIT,
  /** We're remapping this address because we got a DNS resolution from a
   * Tor server that told us what its value was. */
  ADDRMAPSRC_DNS,

  /** No remapping has occurred.  This isn't a possible value for an
   * addrmap_entry_t; it's used as a null value when we need to answer "Why
   * did this remapping happen." */
  ADDRMAPSRC_NONE
} addressmap_entry_source_t;
#define addressmap_entry_source_bitfield_t ENUM_BF(addressmap_entry_source_t)

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

/** Used to indicate the type of a circuit event passed to the controller.
 * The various types are defined in control-spec.txt */
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;

/** Used to indicate the type of a CIRC_MINOR event passed to the controller.
 * The various types are defined in control-spec.txt . */
typedef enum circuit_status_minor_event_t {
  CIRC_MINOR_EVENT_PURPOSE_CHANGED,
  CIRC_MINOR_EVENT_CANNIBALIZED,
} circuit_status_minor_event_t;

/** Used to indicate the type of a stream event passed to the controller.
 * The various types are defined in control-spec.txt */
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_EVENT_REMAP        = 8
} stream_status_event_t;

/** Used to indicate the type of an OR connection event passed to the
 * controller.  The various types are defined in control-spec.txt */
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_EVENT_NEW          = 4,
} or_conn_status_event_t;

/** Used to indicate the type of a buildtime event */
typedef enum buildtimeout_set_event_t {
  BUILDTIMEOUT_SET_EVENT_COMPUTED  = 0,
  BUILDTIMEOUT_SET_EVENT_RESET     = 1,
  BUILDTIMEOUT_SET_EVENT_SUSPENDED = 2,
  BUILDTIMEOUT_SET_EVENT_DISCARD = 3,
  BUILDTIMEOUT_SET_EVENT_RESUME = 4
} buildtimeout_set_event_t;

/** Execute the statement <b>stmt</b>, which may log events concerning the
 * connection <b>conn</b>.  To prevent infinite loops, disable log messages
 * being sent 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)                                    \
  STMT_BEGIN                                                            \
    int _log_conn_is_control;                                           \
    tor_assert(conn);                                                   \
    _log_conn_is_control = (conn->type == CONN_TYPE_CONTROL);           \
    if (_log_conn_is_control)                                           \
      disable_control_logging();                                        \
  STMT_BEGIN stmt; STMT_END;                                            \
    if (_log_conn_is_control)                                           \
      enable_control_logging();                                         \
  STMT_END

/** Enum describing various stages of bootstrapping, for use with controller
 * bootstrap status events. The values range from 0 to 100. */
typedef enum {
  BOOTSTRAP_STATUS_UNDEF=-1,
  BOOTSTRAP_STATUS_STARTING=0,
  BOOTSTRAP_STATUS_CONN_DIR=5,
  BOOTSTRAP_STATUS_HANDSHAKE=-2,
  BOOTSTRAP_STATUS_HANDSHAKE_DIR=10,
  BOOTSTRAP_STATUS_ONEHOP_CREATE=15,
  BOOTSTRAP_STATUS_REQUESTING_STATUS=20,
  BOOTSTRAP_STATUS_LOADING_STATUS=25,
  BOOTSTRAP_STATUS_LOADING_KEYS=40,
  BOOTSTRAP_STATUS_REQUESTING_DESCRIPTORS=45,
  BOOTSTRAP_STATUS_LOADING_DESCRIPTORS=50,
  BOOTSTRAP_STATUS_CONN_OR=80,
  BOOTSTRAP_STATUS_HANDSHAKE_OR=85,
  BOOTSTRAP_STATUS_CIRCUIT_CREATE=90,
  BOOTSTRAP_STATUS_DONE=100
} bootstrap_status_t;

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

/** A pair of digests created by dir_split_resource_info_fingerprint_pairs() */
typedef struct {
  char first[DIGEST_LEN];
  char second[DIGEST_LEN];
} fp_pair_t;

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

/** An enum to describe what format we're generating a routerstatus line in.
 */
typedef enum {
  /** For use in a v2 opinion */
  NS_V2,
  /** For use in a consensus networkstatus document (ns flavor) */
  NS_V3_CONSENSUS,
  /** For use in a vote networkstatus document */
  NS_V3_VOTE,
  /** For passing to the controlport in response to a GETINFO request */
  NS_CONTROL_PORT,
  /** For use in a consensus networkstatus document (microdesc flavor) */
  NS_V3_CONSENSUS_MICRODESC
} routerstatus_format_type_t;

#ifdef DIRSERV_PRIVATE
typedef struct measured_bw_line_t {
  char node_id[DIGEST_LEN];
  char node_hex[MAX_HEX_NICKNAME_LEN+1];
  long int bw_kb;
} measured_bw_line_t;

#endif

/********************************* dirvote.c ************************/

/** Describes the schedule by which votes should be generated. */
typedef struct vote_timing_t {
  /** Length in seconds between one consensus becoming valid and the next
   * becoming valid. */
  int vote_interval;
  /** For how many intervals is a consensus valid? */
  int n_intervals_valid;
  /** Time in seconds allowed to propagate votes */
  int vote_delay;
  /** Time in seconds allowed to propagate signatures */
  int dist_delay;
} vote_timing_t;

/********************************* geoip.c **************************/

/** Indicates an action that we might be noting geoip statistics on.
 * Note that if we're noticing CONNECT, we're a bridge, and if we're noticing
 * the others, we're not.
 */
typedef enum {
  /** We've noticed a connection as a bridge relay or entry guard. */
  GEOIP_CLIENT_CONNECT = 0,
  /** We've served a networkstatus consensus as a directory server. */
  GEOIP_CLIENT_NETWORKSTATUS = 1,
} geoip_client_action_t;
/** Indicates either a positive reply or a reason for rejectng a network
 * status request that will be included in geoip statistics. */
typedef enum {
  /** Request is answered successfully. */
  GEOIP_SUCCESS = 0,
  /** V3 network status is not signed by a sufficient number of requested
   * authorities. */
  GEOIP_REJECT_NOT_ENOUGH_SIGS = 1,
  /** Requested network status object is unavailable. */
  GEOIP_REJECT_UNAVAILABLE = 2,
  /** Requested network status not found. */
  GEOIP_REJECT_NOT_FOUND = 3,
  /** Network status has not been modified since If-Modified-Since time. */
  GEOIP_REJECT_NOT_MODIFIED = 4,
  /** Directory is busy. */
  GEOIP_REJECT_BUSY = 5,
} geoip_ns_response_t;
#define GEOIP_NS_RESPONSE_NUM 6

/** Directory requests that we are measuring can be either direct or
 * tunneled. */
typedef enum {
  DIRREQ_DIRECT = 0,
  DIRREQ_TUNNELED = 1,
} dirreq_type_t;

/** Possible states for either direct or tunneled directory requests that
 * are relevant for determining network status download times. */
typedef enum {
  /** Found that the client requests a network status; applies to both
   * direct and tunneled requests; initial state of a request that we are
   * measuring. */
  DIRREQ_IS_FOR_NETWORK_STATUS = 0,
  /** Finished writing a network status to the directory connection;
   * applies to both direct and tunneled requests; completes a direct
   * request. */
  DIRREQ_FLUSHING_DIR_CONN_FINISHED = 1,
  /** END cell sent to circuit that initiated a tunneled request. */
  DIRREQ_END_CELL_SENT = 2,
  /** Flushed last cell from queue of the circuit that initiated a
    * tunneled request to the outbuf of the OR connection. */
  DIRREQ_CIRC_QUEUE_FLUSHED = 3,
  /** Flushed last byte from buffer of the channel belonging to the
    * circuit that initiated a tunneled request; completes a tunneled
    * request. */
  DIRREQ_CHANNEL_BUFFER_FLUSHED = 4
} dirreq_state_t;

#define WRITE_STATS_INTERVAL (24*60*60)

/********************************* microdesc.c *************************/

typedef struct microdesc_cache_t microdesc_cache_t;

/********************************* networkstatus.c *********************/

/** Possible statuses of a version of Tor, given opinions from the directory
 * servers. */
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, but later recommended versions exist.
                       */
  VS_UNRECOMMENDED=4, /**< This version is not recommended (general case). */
  VS_EMPTY=5, /**< The version list was empty; no agreed-on versions. */
  VS_UNKNOWN, /**< We have no idea. */
} version_status_t;

/********************************* policies.c ************************/

/** Outcome of applying an address policy to an address. */
typedef enum {
  /** The address was accepted */
  ADDR_POLICY_ACCEPTED=0,
  /** The address was rejected */
  ADDR_POLICY_REJECTED=-1,
  /** Part of the address was unknown, but as far as we can tell, it was
   * accepted. */
  ADDR_POLICY_PROBABLY_ACCEPTED=1,
  /** Part of the address was unknown, but as far as we can tell, it was
   * rejected. */
  ADDR_POLICY_PROBABLY_REJECTED=2,
} addr_policy_result_t;

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

/** Possible public/private key operations in Tor: used to keep track of where
 * we're spending our time. */
typedef enum {
  SIGN_DIR, SIGN_RTR,
  VERIFY_DIR, VERIFY_RTR,
  ENC_ONIONSKIN, DEC_ONIONSKIN,
  TLS_HANDSHAKE_C, TLS_HANDSHAKE_S,
  REND_CLIENT, REND_MID, REND_SERVER,
} pk_op_t;

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

/** Hidden-service side configuration of client authorization. */
typedef struct rend_authorized_client_t {
  char *client_name;
  char descriptor_cookie[REND_DESC_COOKIE_LEN];
  crypto_pk_t *client_key;
} rend_authorized_client_t;

/** ASCII-encoded v2 hidden service descriptor. */
typedef struct rend_encoded_v2_service_descriptor_t {
  char desc_id[DIGEST_LEN]; /**< Descriptor ID. */
  char *desc_str; /**< Descriptor string. */
} rend_encoded_v2_service_descriptor_t;

/** The maximum number of non-circuit-build-timeout failures a hidden
 * service client will tolerate while trying to build a circuit to an
 * introduction point.  See also rend_intro_point_t.unreachable_count. */
#define MAX_INTRO_POINT_REACHABILITY_FAILURES 5

/** The maximum number of distinct INTRODUCE2 cells which a hidden
 * service's introduction point will receive before it begins to
 * expire.
 *
 * XXX023 Is this number at all sane? */
#define INTRO_POINT_LIFETIME_INTRODUCTIONS 16384

/** The minimum number of seconds that an introduction point will last
 * before expiring due to old age.  (If it receives
 * INTRO_POINT_LIFETIME_INTRODUCTIONS INTRODUCE2 cells, it may expire
 * sooner.)
 *
 * XXX023 Should this be configurable? */
#define INTRO_POINT_LIFETIME_MIN_SECONDS (18*60*60)
/** The maximum number of seconds that an introduction point will last
 * before expiring due to old age.
 *
 * XXX023 Should this be configurable? */
#define INTRO_POINT_LIFETIME_MAX_SECONDS (24*60*60)

/** Introduction point information.  Used both in rend_service_t (on
 * the service side) and in rend_service_descriptor_t (on both the
 * client and service side). */
typedef struct rend_intro_point_t {
  extend_info_t *extend_info; /**< Extend info of this introduction point. */
  crypto_pk_t *intro_key; /**< Introduction key that replaces the service
                               * key, if this descriptor is V2. */

  /** (Client side only) Flag indicating that a timeout has occurred
   * after sending an INTRODUCE cell to this intro point.  After a
   * timeout, an intro point should not be tried again during the same
   * hidden service connection attempt, but it may be tried again
   * during a future connection attempt. */
  unsigned int timed_out : 1;

  /** (Client side only) The number of times we have failed to build a
   * circuit to this intro point for some reason other than our
   * circuit-build timeout.  See also MAX_INTRO_POINT_REACHABILITY_FAILURES. */
  unsigned int unreachable_count : 3;

  /** (Service side only) Flag indicating that this intro point was
   * included in the last HS descriptor we generated. */
  unsigned int listed_in_last_desc : 1;

  /** (Service side only) Flag indicating that
   * rend_service_note_removing_intro_point has been called for this
   * intro point. */
  unsigned int rend_service_note_removing_intro_point_called : 1;

  /** (Service side only) A replay cache recording the RSA-encrypted parts
   * of INTRODUCE2 cells this intro point's circuit has received.  This is
   * used to prevent replay attacks. */
  replaycache_t *accepted_intro_rsa_parts;

  /** (Service side only) Count of INTRODUCE2 cells accepted from this
   * intro point.
   */
  int accepted_introduce2_count;

  /** (Service side only) The time at which this intro point was first
   * published, or -1 if this intro point has not yet been
   * published. */
  time_t time_published;

  /** (Service side only) The time at which this intro point should
   * (start to) expire, or -1 if we haven't decided when this intro
   * point should expire. */
  time_t time_to_expire;

  /** (Service side only) The time at which we decided that this intro
   * point should start expiring, or -1 if this intro point is not yet
   * expiring.
   *
   * This field also serves as a flag to indicate that we have decided
   * to expire this intro point, in case intro_point_should_expire_now
   * flaps (perhaps due to a clock jump; perhaps due to other
   * weirdness, or even a (present or future) bug). */
  time_t time_expiring;
} rend_intro_point_t;

#define REND_PROTOCOL_VERSION_BITMASK_WIDTH 16

/** Information used to connect to a hidden service.  Used on both the
 * service side and the client side. */
typedef struct rend_service_descriptor_t {
  crypto_pk_t *pk; /**< This service's public key. */
  int version; /**< Version of the descriptor format: 0 or 2. */
  time_t timestamp; /**< Time when the descriptor was generated. */
  /** Bitmask: which introduce/rendezvous protocols are supported?
   * (We allow bits '0', '1', '2' and '3' to be set.) */
  unsigned protocols : REND_PROTOCOL_VERSION_BITMASK_WIDTH;
  /** List of the service's introduction points.  Elements are removed if
   * introduction attempts fail. */
  smartlist_t *intro_nodes;
  /** Has descriptor been uploaded to all hidden service directories? */
  int all_uploads_performed;
  /** List of hidden service directories to which an upload request for
   * this descriptor could be sent. Smartlist exists only when at least one
   * of the previous upload requests failed (otherwise it's not important
   * to know which uploads succeeded and which not). */
  smartlist_t *successful_uploads;
} rend_service_descriptor_t;

/** 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;

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

/** Represents information about a single trusted or fallback directory
 * server. */
typedef struct dir_server_t {
  char *description;
  char *nickname;
  char *address; /**< Hostname. */
  uint32_t addr; /**< IPv4 address. */
  uint16_t dir_port; /**< Directory port. */
  uint16_t or_port; /**< OR port: Used for tunneling connections. */
  double weight; /** Weight used when selecting this node at random */
  char digest[DIGEST_LEN]; /**< Digest of identity key. */
  char v3_identity_digest[DIGEST_LEN]; /**< Digest of v3 (authority only,
                                        * high-security) identity key. */

  unsigned int is_running:1; /**< True iff we think this server is running. */
  unsigned int is_authority:1; /**< True iff this is a directory authority
                                * of some kind. */

  /** True iff this server has accepted the most recent server descriptor
   * we tried to upload to it. */
  unsigned int has_accepted_serverdesc:1;

  /** What kind of authority is this? (Bitfield.) */
  dirinfo_type_t type;

  time_t addr_current_at; /**< When was the document that we derived the
                           * address information from published? */

  routerstatus_t fake_status; /**< Used when we need to pass this trusted
                               * dir_server_t to directory_initiate_command_*
                               * as a routerstatus_t.  Not updated by the
                               * router-status management code!
                               **/
} dir_server_t;

#define ROUTER_REQUIRED_MIN_BANDWIDTH (20*1024)

#define ROUTER_MAX_DECLARED_BANDWIDTH INT32_MAX

/* Flags for pick_directory_server() and pick_trusteddirserver(). */
/** Flag to indicate that we should not automatically be willing to use
 * ourself to answer a directory request.
 * Passed to router_pick_directory_server (et al).*/
#define PDS_ALLOW_SELF                 (1<<0)
/** Flag to indicate that if no servers seem to be up, we should mark all
 * directory servers as up and try again.
 * Passed to router_pick_directory_server (et al).*/
#define PDS_RETRY_IF_NO_SERVERS        (1<<1)
/** Flag to indicate that we should not exclude directory servers that
 * our ReachableAddress settings would exclude.  This usually means that
 * we're going to connect to the server over Tor, and so we don't need to
 * worry about our firewall telling us we can't.
 * Passed to router_pick_directory_server (et al).*/
#define PDS_IGNORE_FASCISTFIREWALL     (1<<2)
/** Flag to indicate that we should not use any directory authority to which
 * we have an existing directory connection for downloading server descriptors
 * or extrainfo documents.
 *
 * Passed to router_pick_directory_server (et al)
 *
 * [XXXX NOTE: This option is only implemented for pick_trusteddirserver,
 *  not pick_directory_server.  If we make it work on pick_directory_server
 *  too, we could conservatively make it only prevent multiple fetches to
 *  the same authority, or we could aggressively make it prevent multiple
 *  fetches to _any_ single directory server.]
 */
#define PDS_NO_EXISTING_SERVERDESC_FETCH (1<<3)
#define PDS_NO_EXISTING_MICRODESC_FETCH (1<<4)

/** This node is to be chosen as a directory guard, so don't choose any
 * node that's currently a guard. */
#define PDS_FOR_GUARD (1<<5)

#define PDS_PREFER_TUNNELED_DIR_CONNS_ (1<<16)

/** Possible ways to weight routers when choosing one randomly.  See
 * routerlist_sl_choose_by_bandwidth() for more information.*/
typedef enum bandwidth_weight_rule_t {
  NO_WEIGHTING, WEIGHT_FOR_EXIT, WEIGHT_FOR_MID, WEIGHT_FOR_GUARD,
  WEIGHT_FOR_DIR
} bandwidth_weight_rule_t;

/** Flags to be passed to control router_choose_random_node() to indicate what
 * kind of nodes to pick according to what algorithm. */
typedef enum {
  CRN_NEED_UPTIME = 1<<0,
  CRN_NEED_CAPACITY = 1<<1,
  CRN_NEED_GUARD = 1<<2,
  CRN_ALLOW_INVALID = 1<<3,
  /* XXXX not used, apparently. */
  CRN_WEIGHT_AS_EXIT = 1<<5,
  CRN_NEED_DESC = 1<<6
} router_crn_flags_t;

/** Return value for router_add_to_routerlist() and dirserv_add_descriptor() */
typedef enum was_router_added_t {
  ROUTER_ADDED_SUCCESSFULLY = 1,
  ROUTER_ADDED_NOTIFY_GENERATOR = 0,
  ROUTER_BAD_EI = -1,
  ROUTER_WAS_NOT_NEW = -2,
  ROUTER_NOT_IN_CONSENSUS = -3,
  ROUTER_NOT_IN_CONSENSUS_OR_NETWORKSTATUS = -4,
  ROUTER_AUTHDIR_REJECTS = -5,
  ROUTER_WAS_NOT_WANTED = -6
} was_router_added_t;

/********************************* 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;
  char status_tag[MAX_STATUS_TAG_LEN];
  int svn_revision;

  int git_tag_len;
  char git_tag[DIGEST_LEN];
} tor_version_t;

#endif