summaryrefslogtreecommitdiff
path: root/http.c
blob: 3034d10b6804387bc267b27757e2eae2279415d5 (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
#include "git-compat-util.h"
#include "http.h"
#include "config.h"
#include "pack.h"
#include "sideband.h"
#include "run-command.h"
#include "url.h"
#include "urlmatch.h"
#include "credential.h"
#include "version.h"
#include "pkt-line.h"
#include "gettext.h"
#include "transport.h"
#include "packfile.h"
#include "protocol.h"
#include "string-list.h"
#include "object-store.h"

static struct trace_key trace_curl = TRACE_KEY_INIT(CURL);
static int trace_curl_data = 1;
static struct string_list cookies_to_redact = STRING_LIST_INIT_DUP;
#if LIBCURL_VERSION_NUM >= 0x070a08
long int git_curl_ipresolve = CURL_IPRESOLVE_WHATEVER;
#else
long int git_curl_ipresolve;
#endif
int active_requests;
int http_is_verbose;
ssize_t http_post_buffer = 16 * LARGE_PACKET_MAX;

#if LIBCURL_VERSION_NUM >= 0x070a06
#define LIBCURL_CAN_HANDLE_AUTH_ANY
#endif

static int min_curl_sessions = 1;
static int curl_session_count;
#ifdef USE_CURL_MULTI
static int max_requests = -1;
static CURLM *curlm;
#endif
#ifndef NO_CURL_EASY_DUPHANDLE
static CURL *curl_default;
#endif

#define PREV_BUF_SIZE 4096

char curl_errorstr[CURL_ERROR_SIZE];

static int curl_ssl_verify = -1;
static int curl_ssl_try;
static const char *ssl_cert;
static const char *ssl_cipherlist;
static const char *ssl_version;
static struct {
	const char *name;
	long ssl_version;
} sslversions[] = {
	{ "sslv2", CURL_SSLVERSION_SSLv2 },
	{ "sslv3", CURL_SSLVERSION_SSLv3 },
	{ "tlsv1", CURL_SSLVERSION_TLSv1 },
#if LIBCURL_VERSION_NUM >= 0x072200
	{ "tlsv1.0", CURL_SSLVERSION_TLSv1_0 },
	{ "tlsv1.1", CURL_SSLVERSION_TLSv1_1 },
	{ "tlsv1.2", CURL_SSLVERSION_TLSv1_2 },
#endif
#if LIBCURL_VERSION_NUM >= 0x073400
	{ "tlsv1.3", CURL_SSLVERSION_TLSv1_3 },
#endif
};
#if LIBCURL_VERSION_NUM >= 0x070903
static const char *ssl_key;
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
static const char *ssl_capath;
#endif
#if LIBCURL_VERSION_NUM >= 0x071304
static const char *curl_no_proxy;
#endif
#if LIBCURL_VERSION_NUM >= 0x072c00
static const char *ssl_pinnedkey;
#endif
static const char *ssl_cainfo;
static long curl_low_speed_limit = -1;
static long curl_low_speed_time = -1;
static int curl_ftp_no_epsv;
static const char *curl_http_proxy;
static const char *http_proxy_authmethod;
static struct {
	const char *name;
	long curlauth_param;
} proxy_authmethods[] = {
	{ "basic", CURLAUTH_BASIC },
	{ "digest", CURLAUTH_DIGEST },
	{ "negotiate", CURLAUTH_GSSNEGOTIATE },
	{ "ntlm", CURLAUTH_NTLM },
#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
	{ "anyauth", CURLAUTH_ANY },
#endif
	/*
	 * CURLAUTH_DIGEST_IE has no corresponding command-line option in
	 * curl(1) and is not included in CURLAUTH_ANY, so we leave it out
	 * here, too
	 */
};
#ifdef CURLGSSAPI_DELEGATION_FLAG
static const char *curl_deleg;
static struct {
	const char *name;
	long curl_deleg_param;
} curl_deleg_levels[] = {
	{ "none", CURLGSSAPI_DELEGATION_NONE },
	{ "policy", CURLGSSAPI_DELEGATION_POLICY_FLAG },
	{ "always", CURLGSSAPI_DELEGATION_FLAG },
};
#endif

static struct credential proxy_auth = CREDENTIAL_INIT;
static const char *curl_proxyuserpwd;
static const char *curl_cookie_file;
static int curl_save_cookies;
struct credential http_auth = CREDENTIAL_INIT;
static int http_proactive_auth;
static const char *user_agent;
static int curl_empty_auth = -1;

enum http_follow_config http_follow_config = HTTP_FOLLOW_INITIAL;

#if LIBCURL_VERSION_NUM >= 0x071700
/* Use CURLOPT_KEYPASSWD as is */
#elif LIBCURL_VERSION_NUM >= 0x070903
#define CURLOPT_KEYPASSWD CURLOPT_SSLKEYPASSWD
#else
#define CURLOPT_KEYPASSWD CURLOPT_SSLCERTPASSWD
#endif

static struct credential cert_auth = CREDENTIAL_INIT;
static int ssl_cert_password_required;
#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
static unsigned long http_auth_methods = CURLAUTH_ANY;
static int http_auth_methods_restricted;
/* Modes for which empty_auth cannot actually help us. */
static unsigned long empty_auth_useless =
	CURLAUTH_BASIC
#ifdef CURLAUTH_DIGEST_IE
	| CURLAUTH_DIGEST_IE
#endif
	| CURLAUTH_DIGEST;
#endif

static struct curl_slist *pragma_header;
static struct curl_slist *no_pragma_header;
static struct curl_slist *extra_http_headers;

static struct active_request_slot *active_queue_head;

static char *cached_accept_language;

size_t fread_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
{
	size_t size = eltsize * nmemb;
	struct buffer *buffer = buffer_;

	if (size > buffer->buf.len - buffer->posn)
		size = buffer->buf.len - buffer->posn;
	memcpy(ptr, buffer->buf.buf + buffer->posn, size);
	buffer->posn += size;

	return size;
}

#ifndef NO_CURL_IOCTL
curlioerr ioctl_buffer(CURL *handle, int cmd, void *clientp)
{
	struct buffer *buffer = clientp;

	switch (cmd) {
	case CURLIOCMD_NOP:
		return CURLIOE_OK;

	case CURLIOCMD_RESTARTREAD:
		buffer->posn = 0;
		return CURLIOE_OK;

	default:
		return CURLIOE_UNKNOWNCMD;
	}
}
#endif

size_t fwrite_buffer(char *ptr, size_t eltsize, size_t nmemb, void *buffer_)
{
	size_t size = eltsize * nmemb;
	struct strbuf *buffer = buffer_;

	strbuf_add(buffer, ptr, size);
	return size;
}

size_t fwrite_null(char *ptr, size_t eltsize, size_t nmemb, void *strbuf)
{
	return eltsize * nmemb;
}

static void closedown_active_slot(struct active_request_slot *slot)
{
	active_requests--;
	slot->in_use = 0;
}

static void finish_active_slot(struct active_request_slot *slot)
{
	closedown_active_slot(slot);
	curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE, &slot->http_code);

	if (slot->finished != NULL)
		(*slot->finished) = 1;

	/* Store slot results so they can be read after the slot is reused */
	if (slot->results != NULL) {
		slot->results->curl_result = slot->curl_result;
		slot->results->http_code = slot->http_code;
#if LIBCURL_VERSION_NUM >= 0x070a08
		curl_easy_getinfo(slot->curl, CURLINFO_HTTPAUTH_AVAIL,
				  &slot->results->auth_avail);
#else
		slot->results->auth_avail = 0;
#endif

		curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CONNECTCODE,
			&slot->results->http_connectcode);
	}

	/* Run callback if appropriate */
	if (slot->callback_func != NULL)
		slot->callback_func(slot->callback_data);
}

static void xmulti_remove_handle(struct active_request_slot *slot)
{
#ifdef USE_CURL_MULTI
	curl_multi_remove_handle(curlm, slot->curl);
#endif
}

#ifdef USE_CURL_MULTI
static void process_curl_messages(void)
{
	int num_messages;
	struct active_request_slot *slot;
	CURLMsg *curl_message = curl_multi_info_read(curlm, &num_messages);

	while (curl_message != NULL) {
		if (curl_message->msg == CURLMSG_DONE) {
			int curl_result = curl_message->data.result;
			slot = active_queue_head;
			while (slot != NULL &&
			       slot->curl != curl_message->easy_handle)
				slot = slot->next;
			if (slot != NULL) {
				xmulti_remove_handle(slot);
				slot->curl_result = curl_result;
				finish_active_slot(slot);
			} else {
				fprintf(stderr, "Received DONE message for unknown request!\n");
			}
		} else {
			fprintf(stderr, "Unknown CURL message received: %d\n",
				(int)curl_message->msg);
		}
		curl_message = curl_multi_info_read(curlm, &num_messages);
	}
}
#endif

static int http_options(const char *var, const char *value, void *cb)
{
	if (!strcmp("http.sslverify", var)) {
		curl_ssl_verify = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp("http.sslcipherlist", var))
		return git_config_string(&ssl_cipherlist, var, value);
	if (!strcmp("http.sslversion", var))
		return git_config_string(&ssl_version, var, value);
	if (!strcmp("http.sslcert", var))
		return git_config_pathname(&ssl_cert, var, value);
#if LIBCURL_VERSION_NUM >= 0x070903
	if (!strcmp("http.sslkey", var))
		return git_config_pathname(&ssl_key, var, value);
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
	if (!strcmp("http.sslcapath", var))
		return git_config_pathname(&ssl_capath, var, value);
#endif
	if (!strcmp("http.sslcainfo", var))
		return git_config_pathname(&ssl_cainfo, var, value);
	if (!strcmp("http.sslcertpasswordprotected", var)) {
		ssl_cert_password_required = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp("http.ssltry", var)) {
		curl_ssl_try = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp("http.minsessions", var)) {
		min_curl_sessions = git_config_int(var, value);
#ifndef USE_CURL_MULTI
		if (min_curl_sessions > 1)
			min_curl_sessions = 1;
#endif
		return 0;
	}
#ifdef USE_CURL_MULTI
	if (!strcmp("http.maxrequests", var)) {
		max_requests = git_config_int(var, value);
		return 0;
	}
#endif
	if (!strcmp("http.lowspeedlimit", var)) {
		curl_low_speed_limit = (long)git_config_int(var, value);
		return 0;
	}
	if (!strcmp("http.lowspeedtime", var)) {
		curl_low_speed_time = (long)git_config_int(var, value);
		return 0;
	}

	if (!strcmp("http.noepsv", var)) {
		curl_ftp_no_epsv = git_config_bool(var, value);
		return 0;
	}
	if (!strcmp("http.proxy", var))
		return git_config_string(&curl_http_proxy, var, value);

	if (!strcmp("http.proxyauthmethod", var))
		return git_config_string(&http_proxy_authmethod, var, value);

	if (!strcmp("http.cookiefile", var))
		return git_config_pathname(&curl_cookie_file, var, value);
	if (!strcmp("http.savecookies", var)) {
		curl_save_cookies = git_config_bool(var, value);
		return 0;
	}

	if (!strcmp("http.postbuffer", var)) {
		http_post_buffer = git_config_ssize_t(var, value);
		if (http_post_buffer < 0)
			warning(_("negative value for http.postbuffer; defaulting to %d"), LARGE_PACKET_MAX);
		if (http_post_buffer < LARGE_PACKET_MAX)
			http_post_buffer = LARGE_PACKET_MAX;
		return 0;
	}

	if (!strcmp("http.useragent", var))
		return git_config_string(&user_agent, var, value);

	if (!strcmp("http.emptyauth", var)) {
		if (value && !strcmp("auto", value))
			curl_empty_auth = -1;
		else
			curl_empty_auth = git_config_bool(var, value);
		return 0;
	}

	if (!strcmp("http.delegation", var)) {
#ifdef CURLGSSAPI_DELEGATION_FLAG
		return git_config_string(&curl_deleg, var, value);
#else
		warning(_("Delegation control is not supported with cURL < 7.22.0"));
		return 0;
#endif
	}

	if (!strcmp("http.pinnedpubkey", var)) {
#if LIBCURL_VERSION_NUM >= 0x072c00
		return git_config_pathname(&ssl_pinnedkey, var, value);
#else
		warning(_("Public key pinning not supported with cURL < 7.44.0"));
		return 0;
#endif
	}

	if (!strcmp("http.extraheader", var)) {
		if (!value) {
			return config_error_nonbool(var);
		} else if (!*value) {
			curl_slist_free_all(extra_http_headers);
			extra_http_headers = NULL;
		} else {
			extra_http_headers =
				curl_slist_append(extra_http_headers, value);
		}
		return 0;
	}

	if (!strcmp("http.followredirects", var)) {
		if (value && !strcmp(value, "initial"))
			http_follow_config = HTTP_FOLLOW_INITIAL;
		else if (git_config_bool(var, value))
			http_follow_config = HTTP_FOLLOW_ALWAYS;
		else
			http_follow_config = HTTP_FOLLOW_NONE;
		return 0;
	}

	/* Fall back on the default ones */
	return git_default_config(var, value, cb);
}

static int curl_empty_auth_enabled(void)
{
	if (curl_empty_auth >= 0)
		return curl_empty_auth;

#ifndef LIBCURL_CAN_HANDLE_AUTH_ANY
	/*
	 * Our libcurl is too old to do AUTH_ANY in the first place;
	 * just default to turning the feature off.
	 */
#else
	/*
	 * In the automatic case, kick in the empty-auth
	 * hack as long as we would potentially try some
	 * method more exotic than "Basic" or "Digest".
	 *
	 * But only do this when this is our second or
	 * subsequent request, as by then we know what
	 * methods are available.
	 */
	if (http_auth_methods_restricted &&
	    (http_auth_methods & ~empty_auth_useless))
		return 1;
#endif
	return 0;
}

static void init_curl_http_auth(CURL *result)
{
	if (!http_auth.username || !*http_auth.username) {
		if (curl_empty_auth_enabled())
			curl_easy_setopt(result, CURLOPT_USERPWD, ":");
		return;
	}

	credential_fill(&http_auth);

#if LIBCURL_VERSION_NUM >= 0x071301
	curl_easy_setopt(result, CURLOPT_USERNAME, http_auth.username);
	curl_easy_setopt(result, CURLOPT_PASSWORD, http_auth.password);
#else
	{
		static struct strbuf up = STRBUF_INIT;
		/*
		 * Note that we assume we only ever have a single set of
		 * credentials in a given program run, so we do not have
		 * to worry about updating this buffer, only setting its
		 * initial value.
		 */
		if (!up.len)
			strbuf_addf(&up, "%s:%s",
				http_auth.username, http_auth.password);
		curl_easy_setopt(result, CURLOPT_USERPWD, up.buf);
	}
#endif
}

/* *var must be free-able */
static void var_override(const char **var, char *value)
{
	if (value) {
		free((void *)*var);
		*var = xstrdup(value);
	}
}

static void set_proxyauth_name_password(CURL *result)
{
#if LIBCURL_VERSION_NUM >= 0x071301
		curl_easy_setopt(result, CURLOPT_PROXYUSERNAME,
			proxy_auth.username);
		curl_easy_setopt(result, CURLOPT_PROXYPASSWORD,
			proxy_auth.password);
#else
		struct strbuf s = STRBUF_INIT;

		strbuf_addstr_urlencode(&s, proxy_auth.username, 1);
		strbuf_addch(&s, ':');
		strbuf_addstr_urlencode(&s, proxy_auth.password, 1);
		curl_proxyuserpwd = strbuf_detach(&s, NULL);
		curl_easy_setopt(result, CURLOPT_PROXYUSERPWD, curl_proxyuserpwd);
#endif
}

static void init_curl_proxy_auth(CURL *result)
{
	if (proxy_auth.username) {
		if (!proxy_auth.password)
			credential_fill(&proxy_auth);
		set_proxyauth_name_password(result);
	}

	var_override(&http_proxy_authmethod, getenv("GIT_HTTP_PROXY_AUTHMETHOD"));

#if LIBCURL_VERSION_NUM >= 0x070a07 /* CURLOPT_PROXYAUTH and CURLAUTH_ANY */
	if (http_proxy_authmethod) {
		int i;
		for (i = 0; i < ARRAY_SIZE(proxy_authmethods); i++) {
			if (!strcmp(http_proxy_authmethod, proxy_authmethods[i].name)) {
				curl_easy_setopt(result, CURLOPT_PROXYAUTH,
						proxy_authmethods[i].curlauth_param);
				break;
			}
		}
		if (i == ARRAY_SIZE(proxy_authmethods)) {
			warning("unsupported proxy authentication method %s: using anyauth",
					http_proxy_authmethod);
			curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
		}
	}
	else
		curl_easy_setopt(result, CURLOPT_PROXYAUTH, CURLAUTH_ANY);
#endif
}

static int has_cert_password(void)
{
	if (ssl_cert == NULL || ssl_cert_password_required != 1)
		return 0;
	if (!cert_auth.password) {
		cert_auth.protocol = xstrdup("cert");
		cert_auth.username = xstrdup("");
		cert_auth.path = xstrdup(ssl_cert);
		credential_fill(&cert_auth);
	}
	return 1;
}

#if LIBCURL_VERSION_NUM >= 0x071900
static void set_curl_keepalive(CURL *c)
{
	curl_easy_setopt(c, CURLOPT_TCP_KEEPALIVE, 1);
}

#elif LIBCURL_VERSION_NUM >= 0x071000
static int sockopt_callback(void *client, curl_socket_t fd, curlsocktype type)
{
	int ka = 1;
	int rc;
	socklen_t len = (socklen_t)sizeof(ka);

	if (type != CURLSOCKTYPE_IPCXN)
		return 0;

	rc = setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, (void *)&ka, len);
	if (rc < 0)
		warning_errno("unable to set SO_KEEPALIVE on socket");

	return 0; /* CURL_SOCKOPT_OK only exists since curl 7.21.5 */
}

static void set_curl_keepalive(CURL *c)
{
	curl_easy_setopt(c, CURLOPT_SOCKOPTFUNCTION, sockopt_callback);
}

#else
static void set_curl_keepalive(CURL *c)
{
	/* not supported on older curl versions */
}
#endif

static void redact_sensitive_header(struct strbuf *header)
{
	const char *sensitive_header;

	if (skip_prefix(header->buf, "Authorization:", &sensitive_header) ||
	    skip_prefix(header->buf, "Proxy-Authorization:", &sensitive_header)) {
		/* The first token is the type, which is OK to log */
		while (isspace(*sensitive_header))
			sensitive_header++;
		while (*sensitive_header && !isspace(*sensitive_header))
			sensitive_header++;
		/* Everything else is opaque and possibly sensitive */
		strbuf_setlen(header,  sensitive_header - header->buf);
		strbuf_addstr(header, " <redacted>");
	} else if (cookies_to_redact.nr &&
		   skip_prefix(header->buf, "Cookie:", &sensitive_header)) {
		struct strbuf redacted_header = STRBUF_INIT;
		char *cookie;

		while (isspace(*sensitive_header))
			sensitive_header++;

		/*
		 * The contents of header starting from sensitive_header will
		 * subsequently be overridden, so it is fine to mutate this
		 * string (hence the assignment to "char *").
		 */
		cookie = (char *) sensitive_header;

		while (cookie) {
			char *equals;
			char *semicolon = strstr(cookie, "; ");
			if (semicolon)
				*semicolon = 0;
			equals = strchrnul(cookie, '=');
			if (!equals) {
				/* invalid cookie, just append and continue */
				strbuf_addstr(&redacted_header, cookie);
				continue;
			}
			*equals = 0; /* temporarily set to NUL for lookup */
			if (string_list_lookup(&cookies_to_redact, cookie)) {
				strbuf_addstr(&redacted_header, cookie);
				strbuf_addstr(&redacted_header, "=<redacted>");
			} else {
				*equals = '=';
				strbuf_addstr(&redacted_header, cookie);
			}
			if (semicolon) {
				/*
				 * There are more cookies. (Or, for some
				 * reason, the input string ends in "; ".)
				 */
				strbuf_addstr(&redacted_header, "; ");
				cookie = semicolon + strlen("; ");
			} else {
				cookie = NULL;
			}
		}

		strbuf_setlen(header, sensitive_header - header->buf);
		strbuf_addbuf(header, &redacted_header);
	}
}

static void curl_dump_header(const char *text, unsigned char *ptr, size_t size, int hide_sensitive_header)
{
	struct strbuf out = STRBUF_INIT;
	struct strbuf **headers, **header;

	strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
		text, (long)size, (long)size);
	trace_strbuf(&trace_curl, &out);
	strbuf_reset(&out);
	strbuf_add(&out, ptr, size);
	headers = strbuf_split_max(&out, '\n', 0);

	for (header = headers; *header; header++) {
		if (hide_sensitive_header)
			redact_sensitive_header(*header);
		strbuf_insert((*header), 0, text, strlen(text));
		strbuf_insert((*header), strlen(text), ": ", 2);
		strbuf_rtrim((*header));
		strbuf_addch((*header), '\n');
		trace_strbuf(&trace_curl, (*header));
	}
	strbuf_list_free(headers);
	strbuf_release(&out);
}

static void curl_dump_data(const char *text, unsigned char *ptr, size_t size)
{
	size_t i;
	struct strbuf out = STRBUF_INIT;
	unsigned int width = 60;

	strbuf_addf(&out, "%s, %10.10ld bytes (0x%8.8lx)\n",
		text, (long)size, (long)size);
	trace_strbuf(&trace_curl, &out);

	for (i = 0; i < size; i += width) {
		size_t w;

		strbuf_reset(&out);
		strbuf_addf(&out, "%s: ", text);
		for (w = 0; (w < width) && (i + w < size); w++) {
			unsigned char ch = ptr[i + w];

			strbuf_addch(&out,
				       (ch >= 0x20) && (ch < 0x80)
				       ? ch : '.');
		}
		strbuf_addch(&out, '\n');
		trace_strbuf(&trace_curl, &out);
	}
	strbuf_release(&out);
}

static int curl_trace(CURL *handle, curl_infotype type, char *data, size_t size, void *userp)
{
	const char *text;
	enum { NO_FILTER = 0, DO_FILTER = 1 };

	switch (type) {
	case CURLINFO_TEXT:
		trace_printf_key(&trace_curl, "== Info: %s", data);
		break;
	case CURLINFO_HEADER_OUT:
		text = "=> Send header";
		curl_dump_header(text, (unsigned char *)data, size, DO_FILTER);
		break;
	case CURLINFO_DATA_OUT:
		if (trace_curl_data) {
			text = "=> Send data";
			curl_dump_data(text, (unsigned char *)data, size);
		}
		break;
	case CURLINFO_SSL_DATA_OUT:
		if (trace_curl_data) {
			text = "=> Send SSL data";
			curl_dump_data(text, (unsigned char *)data, size);
		}
		break;
	case CURLINFO_HEADER_IN:
		text = "<= Recv header";
		curl_dump_header(text, (unsigned char *)data, size, NO_FILTER);
		break;
	case CURLINFO_DATA_IN:
		if (trace_curl_data) {
			text = "<= Recv data";
			curl_dump_data(text, (unsigned char *)data, size);
		}
		break;
	case CURLINFO_SSL_DATA_IN:
		if (trace_curl_data) {
			text = "<= Recv SSL data";
			curl_dump_data(text, (unsigned char *)data, size);
		}
		break;

	default:		/* we ignore unknown types by default */
		return 0;
	}
	return 0;
}

void setup_curl_trace(CURL *handle)
{
	if (!trace_want(&trace_curl))
		return;
	curl_easy_setopt(handle, CURLOPT_VERBOSE, 1L);
	curl_easy_setopt(handle, CURLOPT_DEBUGFUNCTION, curl_trace);
	curl_easy_setopt(handle, CURLOPT_DEBUGDATA, NULL);
}

#ifdef CURLPROTO_HTTP
static long get_curl_allowed_protocols(int from_user)
{
	long allowed_protocols = 0;

	if (is_transport_allowed("http", from_user))
		allowed_protocols |= CURLPROTO_HTTP;
	if (is_transport_allowed("https", from_user))
		allowed_protocols |= CURLPROTO_HTTPS;
	if (is_transport_allowed("ftp", from_user))
		allowed_protocols |= CURLPROTO_FTP;
	if (is_transport_allowed("ftps", from_user))
		allowed_protocols |= CURLPROTO_FTPS;

	return allowed_protocols;
}
#endif

static CURL *get_curl_handle(void)
{
	CURL *result = curl_easy_init();

	if (!result)
		die("curl_easy_init failed");

	if (!curl_ssl_verify) {
		curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 0);
		curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 0);
	} else {
		/* Verify authenticity of the peer's certificate */
		curl_easy_setopt(result, CURLOPT_SSL_VERIFYPEER, 1);
		/* The name in the cert must match whom we tried to connect */
		curl_easy_setopt(result, CURLOPT_SSL_VERIFYHOST, 2);
	}

#if LIBCURL_VERSION_NUM >= 0x070907
	curl_easy_setopt(result, CURLOPT_NETRC, CURL_NETRC_OPTIONAL);
#endif
#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
	curl_easy_setopt(result, CURLOPT_HTTPAUTH, CURLAUTH_ANY);
#endif

#ifdef CURLGSSAPI_DELEGATION_FLAG
	if (curl_deleg) {
		int i;
		for (i = 0; i < ARRAY_SIZE(curl_deleg_levels); i++) {
			if (!strcmp(curl_deleg, curl_deleg_levels[i].name)) {
				curl_easy_setopt(result, CURLOPT_GSSAPI_DELEGATION,
						curl_deleg_levels[i].curl_deleg_param);
				break;
			}
		}
		if (i == ARRAY_SIZE(curl_deleg_levels))
			warning("Unknown delegation method '%s': using default",
				curl_deleg);
	}
#endif

	if (http_proactive_auth)
		init_curl_http_auth(result);

	if (getenv("GIT_SSL_VERSION"))
		ssl_version = getenv("GIT_SSL_VERSION");
	if (ssl_version && *ssl_version) {
		int i;
		for (i = 0; i < ARRAY_SIZE(sslversions); i++) {
			if (!strcmp(ssl_version, sslversions[i].name)) {
				curl_easy_setopt(result, CURLOPT_SSLVERSION,
						 sslversions[i].ssl_version);
				break;
			}
		}
		if (i == ARRAY_SIZE(sslversions))
			warning("unsupported ssl version %s: using default",
				ssl_version);
	}

	if (getenv("GIT_SSL_CIPHER_LIST"))
		ssl_cipherlist = getenv("GIT_SSL_CIPHER_LIST");
	if (ssl_cipherlist != NULL && *ssl_cipherlist)
		curl_easy_setopt(result, CURLOPT_SSL_CIPHER_LIST,
				ssl_cipherlist);

	if (ssl_cert != NULL)
		curl_easy_setopt(result, CURLOPT_SSLCERT, ssl_cert);
	if (has_cert_password())
		curl_easy_setopt(result, CURLOPT_KEYPASSWD, cert_auth.password);
#if LIBCURL_VERSION_NUM >= 0x070903
	if (ssl_key != NULL)
		curl_easy_setopt(result, CURLOPT_SSLKEY, ssl_key);
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
	if (ssl_capath != NULL)
		curl_easy_setopt(result, CURLOPT_CAPATH, ssl_capath);
#endif
#if LIBCURL_VERSION_NUM >= 0x072c00
	if (ssl_pinnedkey != NULL)
		curl_easy_setopt(result, CURLOPT_PINNEDPUBLICKEY, ssl_pinnedkey);
#endif
	if (ssl_cainfo != NULL)
		curl_easy_setopt(result, CURLOPT_CAINFO, ssl_cainfo);

	if (curl_low_speed_limit > 0 && curl_low_speed_time > 0) {
		curl_easy_setopt(result, CURLOPT_LOW_SPEED_LIMIT,
				 curl_low_speed_limit);
		curl_easy_setopt(result, CURLOPT_LOW_SPEED_TIME,
				 curl_low_speed_time);
	}

	curl_easy_setopt(result, CURLOPT_MAXREDIRS, 20);
#if LIBCURL_VERSION_NUM >= 0x071301
	curl_easy_setopt(result, CURLOPT_POSTREDIR, CURL_REDIR_POST_ALL);
#elif LIBCURL_VERSION_NUM >= 0x071101
	curl_easy_setopt(result, CURLOPT_POST301, 1);
#endif
#ifdef CURLPROTO_HTTP
	curl_easy_setopt(result, CURLOPT_REDIR_PROTOCOLS,
			 get_curl_allowed_protocols(0));
	curl_easy_setopt(result, CURLOPT_PROTOCOLS,
			 get_curl_allowed_protocols(-1));
#else
	warning("protocol restrictions not applied to curl redirects because\n"
		"your curl version is too old (>= 7.19.4)");
#endif
	if (getenv("GIT_CURL_VERBOSE"))
		curl_easy_setopt(result, CURLOPT_VERBOSE, 1L);
	setup_curl_trace(result);
	if (getenv("GIT_TRACE_CURL_NO_DATA"))
		trace_curl_data = 0;
	if (getenv("GIT_REDACT_COOKIES")) {
		string_list_split(&cookies_to_redact,
				  getenv("GIT_REDACT_COOKIES"), ',', -1);
		string_list_sort(&cookies_to_redact);
	}

	curl_easy_setopt(result, CURLOPT_USERAGENT,
		user_agent ? user_agent : git_user_agent());

	if (curl_ftp_no_epsv)
		curl_easy_setopt(result, CURLOPT_FTP_USE_EPSV, 0);

#ifdef CURLOPT_USE_SSL
	if (curl_ssl_try)
		curl_easy_setopt(result, CURLOPT_USE_SSL, CURLUSESSL_TRY);
#endif

	/*
	 * CURL also examines these variables as a fallback; but we need to query
	 * them here in order to decide whether to prompt for missing password (cf.
	 * init_curl_proxy_auth()).
	 *
	 * Unlike many other common environment variables, these are historically
	 * lowercase only. It appears that CURL did not know this and implemented
	 * only uppercase variants, which was later corrected to take both - with
	 * the exception of http_proxy, which is lowercase only also in CURL. As
	 * the lowercase versions are the historical quasi-standard, they take
	 * precedence here, as in CURL.
	 */
	if (!curl_http_proxy) {
		if (http_auth.protocol && !strcmp(http_auth.protocol, "https")) {
			var_override(&curl_http_proxy, getenv("HTTPS_PROXY"));
			var_override(&curl_http_proxy, getenv("https_proxy"));
		} else {
			var_override(&curl_http_proxy, getenv("http_proxy"));
		}
		if (!curl_http_proxy) {
			var_override(&curl_http_proxy, getenv("ALL_PROXY"));
			var_override(&curl_http_proxy, getenv("all_proxy"));
		}
	}

	if (curl_http_proxy && curl_http_proxy[0] == '\0') {
		/*
		 * Handle case with the empty http.proxy value here to keep
		 * common code clean.
		 * NB: empty option disables proxying at all.
		 */
		curl_easy_setopt(result, CURLOPT_PROXY, "");
	} else if (curl_http_proxy) {
#if LIBCURL_VERSION_NUM >= 0x071800
		if (starts_with(curl_http_proxy, "socks5h"))
			curl_easy_setopt(result,
				CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5_HOSTNAME);
		else if (starts_with(curl_http_proxy, "socks5"))
			curl_easy_setopt(result,
				CURLOPT_PROXYTYPE, CURLPROXY_SOCKS5);
		else if (starts_with(curl_http_proxy, "socks4a"))
			curl_easy_setopt(result,
				CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4A);
		else if (starts_with(curl_http_proxy, "socks"))
			curl_easy_setopt(result,
				CURLOPT_PROXYTYPE, CURLPROXY_SOCKS4);
#endif
#if LIBCURL_VERSION_NUM >= 0x073400
		else if (starts_with(curl_http_proxy, "https"))
			curl_easy_setopt(result,
				CURLOPT_PROXYTYPE, CURLPROXY_HTTPS);
#endif
		if (strstr(curl_http_proxy, "://"))
			credential_from_url(&proxy_auth, curl_http_proxy);
		else {
			struct strbuf url = STRBUF_INIT;
			strbuf_addf(&url, "http://%s", curl_http_proxy);
			credential_from_url(&proxy_auth, url.buf);
			strbuf_release(&url);
		}

		if (!proxy_auth.host)
			die("Invalid proxy URL '%s'", curl_http_proxy);

		curl_easy_setopt(result, CURLOPT_PROXY, proxy_auth.host);
#if LIBCURL_VERSION_NUM >= 0x071304
		var_override(&curl_no_proxy, getenv("NO_PROXY"));
		var_override(&curl_no_proxy, getenv("no_proxy"));
		curl_easy_setopt(result, CURLOPT_NOPROXY, curl_no_proxy);
#endif
	}
	init_curl_proxy_auth(result);

	set_curl_keepalive(result);

	return result;
}

static void set_from_env(const char **var, const char *envname)
{
	const char *val = getenv(envname);
	if (val)
		*var = val;
}

static void protocol_http_header(void)
{
	if (get_protocol_version_config() > 0) {
		struct strbuf protocol_header = STRBUF_INIT;

		strbuf_addf(&protocol_header, GIT_PROTOCOL_HEADER ": version=%d",
			    get_protocol_version_config());


		extra_http_headers = curl_slist_append(extra_http_headers,
						       protocol_header.buf);
		strbuf_release(&protocol_header);
	}
}

void http_init(struct remote *remote, const char *url, int proactive_auth)
{
	char *low_speed_limit;
	char *low_speed_time;
	char *normalized_url;
	struct urlmatch_config config = { STRING_LIST_INIT_DUP };

	config.section = "http";
	config.key = NULL;
	config.collect_fn = http_options;
	config.cascade_fn = git_default_config;
	config.cb = NULL;

	http_is_verbose = 0;
	normalized_url = url_normalize(url, &config.url);

	git_config(urlmatch_config_entry, &config);
	free(normalized_url);

	if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK)
		die("curl_global_init failed");

	http_proactive_auth = proactive_auth;

	if (remote && remote->http_proxy)
		curl_http_proxy = xstrdup(remote->http_proxy);

	if (remote)
		var_override(&http_proxy_authmethod, remote->http_proxy_authmethod);

	protocol_http_header();

	pragma_header = curl_slist_append(http_copy_default_headers(),
		"Pragma: no-cache");
	no_pragma_header = curl_slist_append(http_copy_default_headers(),
		"Pragma:");

#ifdef USE_CURL_MULTI
	{
		char *http_max_requests = getenv("GIT_HTTP_MAX_REQUESTS");
		if (http_max_requests != NULL)
			max_requests = atoi(http_max_requests);
	}

	curlm = curl_multi_init();
	if (!curlm)
		die("curl_multi_init failed");
#endif

	if (getenv("GIT_SSL_NO_VERIFY"))
		curl_ssl_verify = 0;

	set_from_env(&ssl_cert, "GIT_SSL_CERT");
#if LIBCURL_VERSION_NUM >= 0x070903
	set_from_env(&ssl_key, "GIT_SSL_KEY");
#endif
#if LIBCURL_VERSION_NUM >= 0x070908
	set_from_env(&ssl_capath, "GIT_SSL_CAPATH");
#endif
	set_from_env(&ssl_cainfo, "GIT_SSL_CAINFO");

	set_from_env(&user_agent, "GIT_HTTP_USER_AGENT");

	low_speed_limit = getenv("GIT_HTTP_LOW_SPEED_LIMIT");
	if (low_speed_limit != NULL)
		curl_low_speed_limit = strtol(low_speed_limit, NULL, 10);
	low_speed_time = getenv("GIT_HTTP_LOW_SPEED_TIME");
	if (low_speed_time != NULL)
		curl_low_speed_time = strtol(low_speed_time, NULL, 10);

	if (curl_ssl_verify == -1)
		curl_ssl_verify = 1;

	curl_session_count = 0;
#ifdef USE_CURL_MULTI
	if (max_requests < 1)
		max_requests = DEFAULT_MAX_REQUESTS;
#endif

	if (getenv("GIT_CURL_FTP_NO_EPSV"))
		curl_ftp_no_epsv = 1;

	if (url) {
		credential_from_url(&http_auth, url);
		if (!ssl_cert_password_required &&
		    getenv("GIT_SSL_CERT_PASSWORD_PROTECTED") &&
		    starts_with(url, "https://"))
			ssl_cert_password_required = 1;
	}

#ifndef NO_CURL_EASY_DUPHANDLE
	curl_default = get_curl_handle();
#endif
}

void http_cleanup(void)
{
	struct active_request_slot *slot = active_queue_head;

	while (slot != NULL) {
		struct active_request_slot *next = slot->next;
		if (slot->curl != NULL) {
			xmulti_remove_handle(slot);
			curl_easy_cleanup(slot->curl);
		}
		free(slot);
		slot = next;
	}
	active_queue_head = NULL;

#ifndef NO_CURL_EASY_DUPHANDLE
	curl_easy_cleanup(curl_default);
#endif

#ifdef USE_CURL_MULTI
	curl_multi_cleanup(curlm);
#endif
	curl_global_cleanup();

	curl_slist_free_all(extra_http_headers);
	extra_http_headers = NULL;

	curl_slist_free_all(pragma_header);
	pragma_header = NULL;

	curl_slist_free_all(no_pragma_header);
	no_pragma_header = NULL;

	if (curl_http_proxy) {
		free((void *)curl_http_proxy);
		curl_http_proxy = NULL;
	}

	if (proxy_auth.password) {
		memset(proxy_auth.password, 0, strlen(proxy_auth.password));
		FREE_AND_NULL(proxy_auth.password);
	}

	free((void *)curl_proxyuserpwd);
	curl_proxyuserpwd = NULL;

	free((void *)http_proxy_authmethod);
	http_proxy_authmethod = NULL;

	if (cert_auth.password != NULL) {
		memset(cert_auth.password, 0, strlen(cert_auth.password));
		FREE_AND_NULL(cert_auth.password);
	}
	ssl_cert_password_required = 0;

	FREE_AND_NULL(cached_accept_language);
}

struct active_request_slot *get_active_slot(void)
{
	struct active_request_slot *slot = active_queue_head;
	struct active_request_slot *newslot;

#ifdef USE_CURL_MULTI
	int num_transfers;

	/* Wait for a slot to open up if the queue is full */
	while (active_requests >= max_requests) {
		curl_multi_perform(curlm, &num_transfers);
		if (num_transfers < active_requests)
			process_curl_messages();
	}
#endif

	while (slot != NULL && slot->in_use)
		slot = slot->next;

	if (slot == NULL) {
		newslot = xmalloc(sizeof(*newslot));
		newslot->curl = NULL;
		newslot->in_use = 0;
		newslot->next = NULL;

		slot = active_queue_head;
		if (slot == NULL) {
			active_queue_head = newslot;
		} else {
			while (slot->next != NULL)
				slot = slot->next;
			slot->next = newslot;
		}
		slot = newslot;
	}

	if (slot->curl == NULL) {
#ifdef NO_CURL_EASY_DUPHANDLE
		slot->curl = get_curl_handle();
#else
		slot->curl = curl_easy_duphandle(curl_default);
#endif
		curl_session_count++;
	}

	active_requests++;
	slot->in_use = 1;
	slot->results = NULL;
	slot->finished = NULL;
	slot->callback_data = NULL;
	slot->callback_func = NULL;
	curl_easy_setopt(slot->curl, CURLOPT_COOKIEFILE, curl_cookie_file);
	if (curl_save_cookies)
		curl_easy_setopt(slot->curl, CURLOPT_COOKIEJAR, curl_cookie_file);
	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, pragma_header);
	curl_easy_setopt(slot->curl, CURLOPT_ERRORBUFFER, curl_errorstr);
	curl_easy_setopt(slot->curl, CURLOPT_CUSTOMREQUEST, NULL);
	curl_easy_setopt(slot->curl, CURLOPT_READFUNCTION, NULL);
	curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION, NULL);
	curl_easy_setopt(slot->curl, CURLOPT_POSTFIELDS, NULL);
	curl_easy_setopt(slot->curl, CURLOPT_UPLOAD, 0);
	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);
	curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 1);
	curl_easy_setopt(slot->curl, CURLOPT_RANGE, NULL);

	/*
	 * Default following to off unless "ALWAYS" is configured; this gives
	 * callers a sane starting point, and they can tweak for individual
	 * HTTP_FOLLOW_* cases themselves.
	 */
	if (http_follow_config == HTTP_FOLLOW_ALWAYS)
		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);
	else
		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 0);

#if LIBCURL_VERSION_NUM >= 0x070a08
	curl_easy_setopt(slot->curl, CURLOPT_IPRESOLVE, git_curl_ipresolve);
#endif
#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
	curl_easy_setopt(slot->curl, CURLOPT_HTTPAUTH, http_auth_methods);
#endif
	if (http_auth.password || curl_empty_auth_enabled())
		init_curl_http_auth(slot->curl);

	return slot;
}

int start_active_slot(struct active_request_slot *slot)
{
#ifdef USE_CURL_MULTI
	CURLMcode curlm_result = curl_multi_add_handle(curlm, slot->curl);
	int num_transfers;

	if (curlm_result != CURLM_OK &&
	    curlm_result != CURLM_CALL_MULTI_PERFORM) {
		warning("curl_multi_add_handle failed: %s",
			curl_multi_strerror(curlm_result));
		active_requests--;
		slot->in_use = 0;
		return 0;
	}

	/*
	 * We know there must be something to do, since we just added
	 * something.
	 */
	curl_multi_perform(curlm, &num_transfers);
#endif
	return 1;
}

#ifdef USE_CURL_MULTI
struct fill_chain {
	void *data;
	int (*fill)(void *);
	struct fill_chain *next;
};

static struct fill_chain *fill_cfg;

void add_fill_function(void *data, int (*fill)(void *))
{
	struct fill_chain *new_fill = xmalloc(sizeof(*new_fill));
	struct fill_chain **linkp = &fill_cfg;
	new_fill->data = data;
	new_fill->fill = fill;
	new_fill->next = NULL;
	while (*linkp)
		linkp = &(*linkp)->next;
	*linkp = new_fill;
}

void fill_active_slots(void)
{
	struct active_request_slot *slot = active_queue_head;

	while (active_requests < max_requests) {
		struct fill_chain *fill;
		for (fill = fill_cfg; fill; fill = fill->next)
			if (fill->fill(fill->data))
				break;

		if (!fill)
			break;
	}

	while (slot != NULL) {
		if (!slot->in_use && slot->curl != NULL
			&& curl_session_count > min_curl_sessions) {
			curl_easy_cleanup(slot->curl);
			slot->curl = NULL;
			curl_session_count--;
		}
		slot = slot->next;
	}
}

void step_active_slots(void)
{
	int num_transfers;
	CURLMcode curlm_result;

	do {
		curlm_result = curl_multi_perform(curlm, &num_transfers);
	} while (curlm_result == CURLM_CALL_MULTI_PERFORM);
	if (num_transfers < active_requests) {
		process_curl_messages();
		fill_active_slots();
	}
}
#endif

void run_active_slot(struct active_request_slot *slot)
{
#ifdef USE_CURL_MULTI
	fd_set readfds;
	fd_set writefds;
	fd_set excfds;
	int max_fd;
	struct timeval select_timeout;
	int finished = 0;

	slot->finished = &finished;
	while (!finished) {
		step_active_slots();

		if (slot->in_use) {
#if LIBCURL_VERSION_NUM >= 0x070f04
			long curl_timeout;
			curl_multi_timeout(curlm, &curl_timeout);
			if (curl_timeout == 0) {
				continue;
			} else if (curl_timeout == -1) {
				select_timeout.tv_sec  = 0;
				select_timeout.tv_usec = 50000;
			} else {
				select_timeout.tv_sec  =  curl_timeout / 1000;
				select_timeout.tv_usec = (curl_timeout % 1000) * 1000;
			}
#else
			select_timeout.tv_sec  = 0;
			select_timeout.tv_usec = 50000;
#endif

			max_fd = -1;
			FD_ZERO(&readfds);
			FD_ZERO(&writefds);
			FD_ZERO(&excfds);
			curl_multi_fdset(curlm, &readfds, &writefds, &excfds, &max_fd);

			/*
			 * It can happen that curl_multi_timeout returns a pathologically
			 * long timeout when curl_multi_fdset returns no file descriptors
			 * to read.  See commit message for more details.
			 */
			if (max_fd < 0 &&
			    (select_timeout.tv_sec > 0 ||
			     select_timeout.tv_usec > 50000)) {
				select_timeout.tv_sec  = 0;
				select_timeout.tv_usec = 50000;
			}

			select(max_fd+1, &readfds, &writefds, &excfds, &select_timeout);
		}
	}
#else
	while (slot->in_use) {
		slot->curl_result = curl_easy_perform(slot->curl);
		finish_active_slot(slot);
	}
#endif
}

static void release_active_slot(struct active_request_slot *slot)
{
	closedown_active_slot(slot);
	if (slot->curl) {
		xmulti_remove_handle(slot);
		if (curl_session_count > min_curl_sessions) {
			curl_easy_cleanup(slot->curl);
			slot->curl = NULL;
			curl_session_count--;
		}
	}
#ifdef USE_CURL_MULTI
	fill_active_slots();
#endif
}

void finish_all_active_slots(void)
{
	struct active_request_slot *slot = active_queue_head;

	while (slot != NULL)
		if (slot->in_use) {
			run_active_slot(slot);
			slot = active_queue_head;
		} else {
			slot = slot->next;
		}
}

/* Helpers for modifying and creating URLs */
static inline int needs_quote(int ch)
{
	if (((ch >= 'A') && (ch <= 'Z'))
			|| ((ch >= 'a') && (ch <= 'z'))
			|| ((ch >= '0') && (ch <= '9'))
			|| (ch == '/')
			|| (ch == '-')
			|| (ch == '.'))
		return 0;
	return 1;
}

static char *quote_ref_url(const char *base, const char *ref)
{
	struct strbuf buf = STRBUF_INIT;
	const char *cp;
	int ch;

	end_url_with_slash(&buf, base);

	for (cp = ref; (ch = *cp) != 0; cp++)
		if (needs_quote(ch))
			strbuf_addf(&buf, "%%%02x", ch);
		else
			strbuf_addch(&buf, *cp);

	return strbuf_detach(&buf, NULL);
}

void append_remote_object_url(struct strbuf *buf, const char *url,
			      const char *hex,
			      int only_two_digit_prefix)
{
	end_url_with_slash(buf, url);

	strbuf_addf(buf, "objects/%.*s/", 2, hex);
	if (!only_two_digit_prefix)
		strbuf_addstr(buf, hex + 2);
}

char *get_remote_object_url(const char *url, const char *hex,
			    int only_two_digit_prefix)
{
	struct strbuf buf = STRBUF_INIT;
	append_remote_object_url(&buf, url, hex, only_two_digit_prefix);
	return strbuf_detach(&buf, NULL);
}

static int handle_curl_result(struct slot_results *results)
{
	/*
	 * If we see a failing http code with CURLE_OK, we have turned off
	 * FAILONERROR (to keep the server's custom error response), and should
	 * translate the code into failure here.
	 *
	 * Likewise, if we see a redirect (30x code), that means we turned off
	 * redirect-following, and we should treat the result as an error.
	 */
	if (results->curl_result == CURLE_OK &&
	    results->http_code >= 300) {
		results->curl_result = CURLE_HTTP_RETURNED_ERROR;
		/*
		 * Normally curl will already have put the "reason phrase"
		 * from the server into curl_errorstr; unfortunately without
		 * FAILONERROR it is lost, so we can give only the numeric
		 * status code.
		 */
		xsnprintf(curl_errorstr, sizeof(curl_errorstr),
			  "The requested URL returned error: %ld",
			  results->http_code);
	}

	if (results->curl_result == CURLE_OK) {
		credential_approve(&http_auth);
		if (proxy_auth.password)
			credential_approve(&proxy_auth);
		return HTTP_OK;
	} else if (missing_target(results))
		return HTTP_MISSING_TARGET;
	else if (results->http_code == 401) {
		if (http_auth.username && http_auth.password) {
			credential_reject(&http_auth);
			return HTTP_NOAUTH;
		} else {
#ifdef LIBCURL_CAN_HANDLE_AUTH_ANY
			http_auth_methods &= ~CURLAUTH_GSSNEGOTIATE;
			if (results->auth_avail) {
				http_auth_methods &= results->auth_avail;
				http_auth_methods_restricted = 1;
			}
#endif
			return HTTP_REAUTH;
		}
	} else {
		if (results->http_connectcode == 407)
			credential_reject(&proxy_auth);
#if LIBCURL_VERSION_NUM >= 0x070c00
		if (!curl_errorstr[0])
			strlcpy(curl_errorstr,
				curl_easy_strerror(results->curl_result),
				sizeof(curl_errorstr));
#endif
		return HTTP_ERROR;
	}
}

int run_one_slot(struct active_request_slot *slot,
		 struct slot_results *results)
{
	slot->results = results;
	if (!start_active_slot(slot)) {
		xsnprintf(curl_errorstr, sizeof(curl_errorstr),
			  "failed to start HTTP request");
		return HTTP_START_FAILED;
	}

	run_active_slot(slot);
	return handle_curl_result(results);
}

struct curl_slist *http_copy_default_headers(void)
{
	struct curl_slist *headers = NULL, *h;

	for (h = extra_http_headers; h; h = h->next)
		headers = curl_slist_append(headers, h->data);

	return headers;
}

static CURLcode curlinfo_strbuf(CURL *curl, CURLINFO info, struct strbuf *buf)
{
	char *ptr;
	CURLcode ret;

	strbuf_reset(buf);
	ret = curl_easy_getinfo(curl, info, &ptr);
	if (!ret && ptr)
		strbuf_addstr(buf, ptr);
	return ret;
}

/*
 * Check for and extract a content-type parameter. "raw"
 * should be positioned at the start of the potential
 * parameter, with any whitespace already removed.
 *
 * "name" is the name of the parameter. The value is appended
 * to "out".
 */
static int extract_param(const char *raw, const char *name,
			 struct strbuf *out)
{
	size_t len = strlen(name);

	if (strncasecmp(raw, name, len))
		return -1;
	raw += len;

	if (*raw != '=')
		return -1;
	raw++;

	while (*raw && !isspace(*raw) && *raw != ';')
		strbuf_addch(out, *raw++);
	return 0;
}

/*
 * Extract a normalized version of the content type, with any
 * spaces suppressed, all letters lowercased, and no trailing ";"
 * or parameters.
 *
 * Note that we will silently remove even invalid whitespace. For
 * example, "text / plain" is specifically forbidden by RFC 2616,
 * but "text/plain" is the only reasonable output, and this keeps
 * our code simple.
 *
 * If the "charset" argument is not NULL, store the value of any
 * charset parameter there.
 *
 * Example:
 *   "TEXT/PLAIN; charset=utf-8" -> "text/plain", "utf-8"
 *   "text / plain" -> "text/plain"
 */
static void extract_content_type(struct strbuf *raw, struct strbuf *type,
				 struct strbuf *charset)
{
	const char *p;

	strbuf_reset(type);
	strbuf_grow(type, raw->len);
	for (p = raw->buf; *p; p++) {
		if (isspace(*p))
			continue;
		if (*p == ';') {
			p++;
			break;
		}
		strbuf_addch(type, tolower(*p));
	}

	if (!charset)
		return;

	strbuf_reset(charset);
	while (*p) {
		while (isspace(*p) || *p == ';')
			p++;
		if (!extract_param(p, "charset", charset))
			return;
		while (*p && !isspace(*p))
			p++;
	}

	if (!charset->len && starts_with(type->buf, "text/"))
		strbuf_addstr(charset, "ISO-8859-1");
}

static void write_accept_language(struct strbuf *buf)
{
	/*
	 * MAX_DECIMAL_PLACES must not be larger than 3. If it is larger than
	 * that, q-value will be smaller than 0.001, the minimum q-value the
	 * HTTP specification allows. See
	 * http://tools.ietf.org/html/rfc7231#section-5.3.1 for q-value.
	 */
	const int MAX_DECIMAL_PLACES = 3;
	const int MAX_LANGUAGE_TAGS = 1000;
	const int MAX_ACCEPT_LANGUAGE_HEADER_SIZE = 4000;
	char **language_tags = NULL;
	int num_langs = 0;
	const char *s = get_preferred_languages();
	int i;
	struct strbuf tag = STRBUF_INIT;

	/* Don't add Accept-Language header if no language is preferred. */
	if (!s)
		return;

	/*
	 * Split the colon-separated string of preferred languages into
	 * language_tags array.
	 */
	do {
		/* collect language tag */
		for (; *s && (isalnum(*s) || *s == '_'); s++)
			strbuf_addch(&tag, *s == '_' ? '-' : *s);

		/* skip .codeset, @modifier and any other unnecessary parts */
		while (*s && *s != ':')
			s++;

		if (tag.len) {
			num_langs++;
			REALLOC_ARRAY(language_tags, num_langs);
			language_tags[num_langs - 1] = strbuf_detach(&tag, NULL);
			if (num_langs >= MAX_LANGUAGE_TAGS - 1) /* -1 for '*' */
				break;
		}
	} while (*s++);

	/* write Accept-Language header into buf */
	if (num_langs) {
		int last_buf_len = 0;
		int max_q;
		int decimal_places;
		char q_format[32];

		/* add '*' */
		REALLOC_ARRAY(language_tags, num_langs + 1);
		language_tags[num_langs++] = "*"; /* it's OK; this won't be freed */

		/* compute decimal_places */
		for (max_q = 1, decimal_places = 0;
		     max_q < num_langs && decimal_places <= MAX_DECIMAL_PLACES;
		     decimal_places++, max_q *= 10)
			;

		xsnprintf(q_format, sizeof(q_format), ";q=0.%%0%dd", decimal_places);

		strbuf_addstr(buf, "Accept-Language: ");

		for (i = 0; i < num_langs; i++) {
			if (i > 0)
				strbuf_addstr(buf, ", ");

			strbuf_addstr(buf, language_tags[i]);

			if (i > 0)
				strbuf_addf(buf, q_format, max_q - i);

			if (buf->len > MAX_ACCEPT_LANGUAGE_HEADER_SIZE) {
				strbuf_remove(buf, last_buf_len, buf->len - last_buf_len);
				break;
			}

			last_buf_len = buf->len;
		}
	}

	/* free language tags -- last one is a static '*' */
	for (i = 0; i < num_langs - 1; i++)
		free(language_tags[i]);
	free(language_tags);
}

/*
 * Get an Accept-Language header which indicates user's preferred languages.
 *
 * Examples:
 *   LANGUAGE= -> ""
 *   LANGUAGE=ko:en -> "Accept-Language: ko, en; q=0.9, *; q=0.1"
 *   LANGUAGE=ko_KR.UTF-8:sr@latin -> "Accept-Language: ko-KR, sr; q=0.9, *; q=0.1"
 *   LANGUAGE=ko LANG=en_US.UTF-8 -> "Accept-Language: ko, *; q=0.1"
 *   LANGUAGE= LANG=en_US.UTF-8 -> "Accept-Language: en-US, *; q=0.1"
 *   LANGUAGE= LANG=C -> ""
 */
static const char *get_accept_language(void)
{
	if (!cached_accept_language) {
		struct strbuf buf = STRBUF_INIT;
		write_accept_language(&buf);
		if (buf.len > 0)
			cached_accept_language = strbuf_detach(&buf, NULL);
	}

	return cached_accept_language;
}

static void http_opt_request_remainder(CURL *curl, off_t pos)
{
	char buf[128];
	xsnprintf(buf, sizeof(buf), "%"PRIuMAX"-", (uintmax_t)pos);
	curl_easy_setopt(curl, CURLOPT_RANGE, buf);
}

/* http_request() targets */
#define HTTP_REQUEST_STRBUF	0
#define HTTP_REQUEST_FILE	1

static int http_request(const char *url,
			void *result, int target,
			const struct http_get_options *options)
{
	struct active_request_slot *slot;
	struct slot_results results;
	struct curl_slist *headers = http_copy_default_headers();
	struct strbuf buf = STRBUF_INIT;
	const char *accept_language;
	int ret;

	slot = get_active_slot();
	curl_easy_setopt(slot->curl, CURLOPT_HTTPGET, 1);

	if (result == NULL) {
		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 1);
	} else {
		curl_easy_setopt(slot->curl, CURLOPT_NOBODY, 0);
		curl_easy_setopt(slot->curl, CURLOPT_FILE, result);

		if (target == HTTP_REQUEST_FILE) {
			off_t posn = ftello(result);
			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
					 fwrite);
			if (posn > 0)
				http_opt_request_remainder(slot->curl, posn);
		} else
			curl_easy_setopt(slot->curl, CURLOPT_WRITEFUNCTION,
					 fwrite_buffer);
	}

	accept_language = get_accept_language();

	if (accept_language)
		headers = curl_slist_append(headers, accept_language);

	strbuf_addstr(&buf, "Pragma:");
	if (options && options->no_cache)
		strbuf_addstr(&buf, " no-cache");
	if (options && options->keep_error)
		curl_easy_setopt(slot->curl, CURLOPT_FAILONERROR, 0);
	if (options && options->initial_request &&
	    http_follow_config == HTTP_FOLLOW_INITIAL)
		curl_easy_setopt(slot->curl, CURLOPT_FOLLOWLOCATION, 1);

	headers = curl_slist_append(headers, buf.buf);

	curl_easy_setopt(slot->curl, CURLOPT_URL, url);
	curl_easy_setopt(slot->curl, CURLOPT_HTTPHEADER, headers);
	curl_easy_setopt(slot->curl, CURLOPT_ENCODING, "gzip");

	ret = run_one_slot(slot, &results);

	if (options && options->content_type) {
		struct strbuf raw = STRBUF_INIT;
		curlinfo_strbuf(slot->curl, CURLINFO_CONTENT_TYPE, &raw);
		extract_content_type(&raw, options->content_type,
				     options->charset);
		strbuf_release(&raw);
	}

	if (options && options->effective_url)
		curlinfo_strbuf(slot->curl, CURLINFO_EFFECTIVE_URL,
				options->effective_url);

	curl_slist_free_all(headers);
	strbuf_release(&buf);

	return ret;
}

/*
 * Update the "base" url to a more appropriate value, as deduced by
 * redirects seen when requesting a URL starting with "url".
 *
 * The "asked" parameter is a URL that we asked curl to access, and must begin
 * with "base".
 *
 * The "got" parameter is the URL that curl reported to us as where we ended
 * up.
 *
 * Returns 1 if we updated the base url, 0 otherwise.
 *
 * Our basic strategy is to compare "base" and "asked" to find the bits
 * specific to our request. We then strip those bits off of "got" to yield the
 * new base. So for example, if our base is "http://example.com/foo.git",
 * and we ask for "http://example.com/foo.git/info/refs", we might end up
 * with "https://other.example.com/foo.git/info/refs". We would want the
 * new URL to become "https://other.example.com/foo.git".
 *
 * Note that this assumes a sane redirect scheme. It's entirely possible
 * in the example above to end up at a URL that does not even end in
 * "info/refs".  In such a case we die. There's not much we can do, such a
 * scheme is unlikely to represent a real git repository, and failing to
 * rewrite the base opens options for malicious redirects to do funny things.
 */
static int update_url_from_redirect(struct strbuf *base,
				    const char *asked,
				    const struct strbuf *got)
{
	const char *tail;
	size_t new_len;

	if (!strcmp(asked, got->buf))
		return 0;

	if (!skip_prefix(asked, base->buf, &tail))
		die("BUG: update_url_from_redirect: %s is not a superset of %s",
		    asked, base->buf);

	new_len = got->len;
	if (!strip_suffix_mem(got->buf, &new_len, tail))
		die(_("unable to update url base from redirection:\n"
		      "  asked for: %s\n"
		      "   redirect: %s"),
		    asked, got->buf);

	strbuf_reset(base);
	strbuf_add(base, got->buf, new_len);

	return 1;
}

static int http_request_reauth(const char *url,
			       void *result, int target,
			       struct http_get_options *options)
{
	int ret = http_request(url, result, target, options);

	if (ret != HTTP_OK && ret != HTTP_REAUTH)
		return ret;

	if (options && options->effective_url && options->base_url) {
		if (update_url_from_redirect(options->base_url,
					     url, options->effective_url)) {
			credential_from_url(&http_auth, options->base_url->buf);
			url = options->effective_url->buf;
		}
	}

	if (ret != HTTP_REAUTH)
		return ret;

	/*
	 * If we are using KEEP_ERROR, the previous request may have
	 * put cruft into our output stream; we should clear it out before
	 * making our next request. We only know how to do this for
	 * the strbuf case, but that is enough to satisfy current callers.
	 */
	if (options && options->keep_error) {
		switch (target) {
		case HTTP_REQUEST_STRBUF:
			strbuf_reset(result);
			break;
		default:
			die("BUG: HTTP_KEEP_ERROR is only supported with strbufs");
		}
	}

	credential_fill(&http_auth);

	return http_request(url, result, target, options);
}

int http_get_strbuf(const char *url,
		    struct strbuf *result,
		    struct http_get_options *options)
{
	return http_request_reauth(url, result, HTTP_REQUEST_STRBUF, options);
}

/*
 * Downloads a URL and stores the result in the given file.
 *
 * If a previous interrupted download is detected (i.e. a previous temporary
 * file is still around) the download is resumed.
 */
static int http_get_file(const char *url, const char *filename,
			 struct http_get_options *options)
{
	int ret;
	struct strbuf tmpfile = STRBUF_INIT;
	FILE *result;

	strbuf_addf(&tmpfile, "%s.temp", filename);
	result = fopen(tmpfile.buf, "a");
	if (!result) {
		error("Unable to open local file %s", tmpfile.buf);
		ret = HTTP_ERROR;
		goto cleanup;
	}

	ret = http_request_reauth(url, result, HTTP_REQUEST_FILE, options);
	fclose(result);

	if (ret == HTTP_OK && finalize_object_file(tmpfile.buf, filename))
		ret = HTTP_ERROR;
cleanup:
	strbuf_release(&tmpfile);
	return ret;
}

int http_fetch_ref(const char *base, struct ref *ref)
{
	struct http_get_options options = {0};
	char *url;
	struct strbuf buffer = STRBUF_INIT;
	int ret = -1;

	options.no_cache = 1;

	url = quote_ref_url(base, ref->name);
	if (http_get_strbuf(url, &buffer, &options) == HTTP_OK) {
		strbuf_rtrim(&buffer);
		if (buffer.len == 40)
			ret = get_oid_hex(buffer.buf, &ref->old_oid);
		else if (starts_with(buffer.buf, "ref: ")) {
			ref->symref = xstrdup(buffer.buf + 5);
			ret = 0;
		}
	}

	strbuf_release(&buffer);
	free(url);
	return ret;
}

/* Helpers for fetching packs */
static char *fetch_pack_index(unsigned char *sha1, const char *base_url)
{
	char *url, *tmp;
	struct strbuf buf = STRBUF_INIT;

	if (http_is_verbose)
		fprintf(stderr, "Getting index for pack %s\n", sha1_to_hex(sha1));

	end_url_with_slash(&buf, base_url);
	strbuf_addf(&buf, "objects/pack/pack-%s.idx", sha1_to_hex(sha1));
	url = strbuf_detach(&buf, NULL);

	strbuf_addf(&buf, "%s.temp", sha1_pack_index_name(sha1));
	tmp = strbuf_detach(&buf, NULL);

	if (http_get_file(url, tmp, NULL) != HTTP_OK) {
		error("Unable to get pack index %s", url);
		FREE_AND_NULL(tmp);
	}

	free(url);
	return tmp;
}

static int fetch_and_setup_pack_index(struct packed_git **packs_head,
	unsigned char *sha1, const char *base_url)
{
	struct packed_git *new_pack;
	char *tmp_idx = NULL;
	int ret;

	if (has_pack_index(sha1)) {
		new_pack = parse_pack_index(sha1, sha1_pack_index_name(sha1));
		if (!new_pack)
			return -1; /* parse_pack_index() already issued error message */
		goto add_pack;
	}

	tmp_idx = fetch_pack_index(sha1, base_url);
	if (!tmp_idx)
		return -1;

	new_pack = parse_pack_index(sha1, tmp_idx);
	if (!new_pack) {
		unlink(tmp_idx);
		free(tmp_idx);

		return -1; /* parse_pack_index() already issued error message */
	}

	ret = verify_pack_index(new_pack);
	if (!ret) {
		close_pack_index(new_pack);
		ret = finalize_object_file(tmp_idx, sha1_pack_index_name(sha1));
	}
	free(tmp_idx);
	if (ret)
		return -1;

add_pack:
	new_pack->next = *packs_head;
	*packs_head = new_pack;
	return 0;
}

int http_get_info_packs(const char *base_url, struct packed_git **packs_head)
{
	struct http_get_options options = {0};
	int ret = 0, i = 0;
	char *url, *data;
	struct strbuf buf = STRBUF_INIT;
	unsigned char sha1[20];

	end_url_with_slash(&buf, base_url);
	strbuf_addstr(&buf, "objects/info/packs");
	url = strbuf_detach(&buf, NULL);

	options.no_cache = 1;
	ret = http_get_strbuf(url, &buf, &options);
	if (ret != HTTP_OK)
		goto cleanup;

	data = buf.buf;
	while (i < buf.len) {
		switch (data[i]) {
		case 'P':
			i++;
			if (i + 52 <= buf.len &&
			    starts_with(data + i, " pack-") &&
			    starts_with(data + i + 46, ".pack\n")) {
				get_sha1_hex(data + i + 6, sha1);
				fetch_and_setup_pack_index(packs_head, sha1,
						      base_url);
				i += 51;
				break;
			}
		default:
			while (i < buf.len && data[i] != '\n')
				i++;
		}
		i++;
	}

cleanup:
	free(url);
	return ret;
}

void release_http_pack_request(struct http_pack_request *preq)
{
	if (preq->packfile != NULL) {
		fclose(preq->packfile);
		preq->packfile = NULL;
	}
	preq->slot = NULL;
	free(preq->url);
	free(preq);
}

int finish_http_pack_request(struct http_pack_request *preq)
{
	struct packed_git **lst;
	struct packed_git *p = preq->target;
	char *tmp_idx;
	size_t len;
	struct child_process ip = CHILD_PROCESS_INIT;

	close_pack_index(p);

	fclose(preq->packfile);
	preq->packfile = NULL;

	lst = preq->lst;
	while (*lst != p)
		lst = &((*lst)->next);
	*lst = (*lst)->next;

	if (!strip_suffix(preq->tmpfile, ".pack.temp", &len))
		die("BUG: pack tmpfile does not end in .pack.temp?");
	tmp_idx = xstrfmt("%.*s.idx.temp", (int)len, preq->tmpfile);

	argv_array_push(&ip.args, "index-pack");
	argv_array_pushl(&ip.args, "-o", tmp_idx, NULL);
	argv_array_push(&ip.args, preq->tmpfile);
	ip.git_cmd = 1;
	ip.no_stdin = 1;
	ip.no_stdout = 1;

	if (run_command(&ip)) {
		unlink(preq->tmpfile);
		unlink(tmp_idx);
		free(tmp_idx);
		return -1;
	}

	unlink(sha1_pack_index_name(p->sha1));

	if (finalize_object_file(preq->tmpfile, sha1_pack_name(p->sha1))
	 || finalize_object_file(tmp_idx, sha1_pack_index_name(p->sha1))) {
		free(tmp_idx);
		return -1;
	}

	install_packed_git(the_repository, p);
	free(tmp_idx);
	return 0;
}

struct http_pack_request *new_http_pack_request(
	struct packed_git *target, const char *base_url)
{
	off_t prev_posn = 0;
	struct strbuf buf = STRBUF_INIT;
	struct http_pack_request *preq;

	preq = xcalloc(1, sizeof(*preq));
	preq->target = target;

	end_url_with_slash(&buf, base_url);
	strbuf_addf(&buf, "objects/pack/pack-%s.pack",
		sha1_to_hex(target->sha1));
	preq->url = strbuf_detach(&buf, NULL);

	snprintf(preq->tmpfile, sizeof(preq->tmpfile), "%s.temp",
		sha1_pack_name(target->sha1));
	preq->packfile = fopen(preq->tmpfile, "a");
	if (!preq->packfile) {
		error("Unable to open local file %s for pack",
		      preq->tmpfile);
		goto abort;
	}

	preq->slot = get_active_slot();
	curl_easy_setopt(preq->slot->curl, CURLOPT_FILE, preq->packfile);
	curl_easy_setopt(preq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite);
	curl_easy_setopt(preq->slot->curl, CURLOPT_URL, preq->url);
	curl_easy_setopt(preq->slot->curl, CURLOPT_HTTPHEADER,
		no_pragma_header);

	/*
	 * If there is data present from a previous transfer attempt,
	 * resume where it left off
	 */
	prev_posn = ftello(preq->packfile);
	if (prev_posn>0) {
		if (http_is_verbose)
			fprintf(stderr,
				"Resuming fetch of pack %s at byte %"PRIuMAX"\n",
				sha1_to_hex(target->sha1), (uintmax_t)prev_posn);
		http_opt_request_remainder(preq->slot->curl, prev_posn);
	}

	return preq;

abort:
	free(preq->url);
	free(preq);
	return NULL;
}

/* Helpers for fetching objects (loose) */
static size_t fwrite_sha1_file(char *ptr, size_t eltsize, size_t nmemb,
			       void *data)
{
	unsigned char expn[4096];
	size_t size = eltsize * nmemb;
	int posn = 0;
	struct http_object_request *freq = data;
	struct active_request_slot *slot = freq->slot;

	if (slot) {
		CURLcode c = curl_easy_getinfo(slot->curl, CURLINFO_HTTP_CODE,
						&slot->http_code);
		if (c != CURLE_OK)
			die("BUG: curl_easy_getinfo for HTTP code failed: %s",
				curl_easy_strerror(c));
		if (slot->http_code >= 300)
			return size;
	}

	do {
		ssize_t retval = xwrite(freq->localfile,
					(char *) ptr + posn, size - posn);
		if (retval < 0)
			return posn;
		posn += retval;
	} while (posn < size);

	freq->stream.avail_in = size;
	freq->stream.next_in = (void *)ptr;
	do {
		freq->stream.next_out = expn;
		freq->stream.avail_out = sizeof(expn);
		freq->zret = git_inflate(&freq->stream, Z_SYNC_FLUSH);
		git_SHA1_Update(&freq->c, expn,
				sizeof(expn) - freq->stream.avail_out);
	} while (freq->stream.avail_in && freq->zret == Z_OK);
	return size;
}

struct http_object_request *new_http_object_request(const char *base_url,
	unsigned char *sha1)
{
	char *hex = sha1_to_hex(sha1);
	struct strbuf filename = STRBUF_INIT;
	char prevfile[PATH_MAX];
	int prevlocal;
	char prev_buf[PREV_BUF_SIZE];
	ssize_t prev_read = 0;
	off_t prev_posn = 0;
	struct http_object_request *freq;

	freq = xcalloc(1, sizeof(*freq));
	hashcpy(freq->sha1, sha1);
	freq->localfile = -1;

	sha1_file_name(the_repository, &filename, sha1);
	snprintf(freq->tmpfile, sizeof(freq->tmpfile),
		 "%s.temp", filename.buf);

	snprintf(prevfile, sizeof(prevfile), "%s.prev", filename.buf);
	unlink_or_warn(prevfile);
	rename(freq->tmpfile, prevfile);
	unlink_or_warn(freq->tmpfile);
	strbuf_release(&filename);

	if (freq->localfile != -1)
		error("fd leakage in start: %d", freq->localfile);
	freq->localfile = open(freq->tmpfile,
			       O_WRONLY | O_CREAT | O_EXCL, 0666);
	/*
	 * This could have failed due to the "lazy directory creation";
	 * try to mkdir the last path component.
	 */
	if (freq->localfile < 0 && errno == ENOENT) {
		char *dir = strrchr(freq->tmpfile, '/');
		if (dir) {
			*dir = 0;
			mkdir(freq->tmpfile, 0777);
			*dir = '/';
		}
		freq->localfile = open(freq->tmpfile,
				       O_WRONLY | O_CREAT | O_EXCL, 0666);
	}

	if (freq->localfile < 0) {
		error_errno("Couldn't create temporary file %s", freq->tmpfile);
		goto abort;
	}

	git_inflate_init(&freq->stream);

	git_SHA1_Init(&freq->c);

	freq->url = get_remote_object_url(base_url, hex, 0);

	/*
	 * If a previous temp file is present, process what was already
	 * fetched.
	 */
	prevlocal = open(prevfile, O_RDONLY);
	if (prevlocal != -1) {
		do {
			prev_read = xread(prevlocal, prev_buf, PREV_BUF_SIZE);
			if (prev_read>0) {
				if (fwrite_sha1_file(prev_buf,
						     1,
						     prev_read,
						     freq) == prev_read) {
					prev_posn += prev_read;
				} else {
					prev_read = -1;
				}
			}
		} while (prev_read > 0);
		close(prevlocal);
	}
	unlink_or_warn(prevfile);

	/*
	 * Reset inflate/SHA1 if there was an error reading the previous temp
	 * file; also rewind to the beginning of the local file.
	 */
	if (prev_read == -1) {
		memset(&freq->stream, 0, sizeof(freq->stream));
		git_inflate_init(&freq->stream);
		git_SHA1_Init(&freq->c);
		if (prev_posn>0) {
			prev_posn = 0;
			lseek(freq->localfile, 0, SEEK_SET);
			if (ftruncate(freq->localfile, 0) < 0) {
				error_errno("Couldn't truncate temporary file %s",
					    freq->tmpfile);
				goto abort;
			}
		}
	}

	freq->slot = get_active_slot();

	curl_easy_setopt(freq->slot->curl, CURLOPT_FILE, freq);
	curl_easy_setopt(freq->slot->curl, CURLOPT_FAILONERROR, 0);
	curl_easy_setopt(freq->slot->curl, CURLOPT_WRITEFUNCTION, fwrite_sha1_file);
	curl_easy_setopt(freq->slot->curl, CURLOPT_ERRORBUFFER, freq->errorstr);
	curl_easy_setopt(freq->slot->curl, CURLOPT_URL, freq->url);
	curl_easy_setopt(freq->slot->curl, CURLOPT_HTTPHEADER, no_pragma_header);

	/*
	 * If we have successfully processed data from a previous fetch
	 * attempt, only fetch the data we don't already have.
	 */
	if (prev_posn>0) {
		if (http_is_verbose)
			fprintf(stderr,
				"Resuming fetch of object %s at byte %"PRIuMAX"\n",
				hex, (uintmax_t)prev_posn);
		http_opt_request_remainder(freq->slot->curl, prev_posn);
	}

	return freq;

abort:
	free(freq->url);
	free(freq);
	return NULL;
}

void process_http_object_request(struct http_object_request *freq)
{
	if (freq->slot == NULL)
		return;
	freq->curl_result = freq->slot->curl_result;
	freq->http_code = freq->slot->http_code;
	freq->slot = NULL;
}

int finish_http_object_request(struct http_object_request *freq)
{
	struct stat st;
	struct strbuf filename = STRBUF_INIT;

	close(freq->localfile);
	freq->localfile = -1;

	process_http_object_request(freq);

	if (freq->http_code == 416) {
		warning("requested range invalid; we may already have all the data.");
	} else if (freq->curl_result != CURLE_OK) {
		if (stat(freq->tmpfile, &st) == 0)
			if (st.st_size == 0)
				unlink_or_warn(freq->tmpfile);
		return -1;
	}

	git_inflate_end(&freq->stream);
	git_SHA1_Final(freq->real_sha1, &freq->c);
	if (freq->zret != Z_STREAM_END) {
		unlink_or_warn(freq->tmpfile);
		return -1;
	}
	if (hashcmp(freq->sha1, freq->real_sha1)) {
		unlink_or_warn(freq->tmpfile);
		return -1;
	}
	sha1_file_name(the_repository, &filename, freq->sha1);
	freq->rename = finalize_object_file(freq->tmpfile, filename.buf);
	strbuf_release(&filename);

	return freq->rename;
}

void abort_http_object_request(struct http_object_request *freq)
{
	unlink_or_warn(freq->tmpfile);

	release_http_object_request(freq);
}

void release_http_object_request(struct http_object_request *freq)
{
	if (freq->localfile != -1) {
		close(freq->localfile);
		freq->localfile = -1;
	}
	if (freq->url != NULL) {
		FREE_AND_NULL(freq->url);
	}
	if (freq->slot != NULL) {
		freq->slot->callback_func = NULL;
		freq->slot->callback_data = NULL;
		release_active_slot(freq->slot);
		freq->slot = NULL;
	}
}