aboutsummaryrefslogtreecommitdiff
path: root/lib/http.c
blob: ea3e8af3577865d5ade0d137f62454695b7e37d0 (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
/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2017, Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.haxx.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 ***************************************************************************/

#include "curl_setup.h"

#ifndef CURL_DISABLE_HTTP

#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif

#ifdef HAVE_NETDB_H
#include <netdb.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#ifdef HAVE_NET_IF_H
#include <net/if.h>
#endif
#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif

#ifdef HAVE_SYS_PARAM_H
#include <sys/param.h>
#endif

#include "urldata.h"
#include <curl/curl.h>
#include "transfer.h"
#include "sendf.h"
#include "formdata.h"
#include "mime.h"
#include "progress.h"
#include "curl_base64.h"
#include "cookie.h"
#include "vauth/vauth.h"
#include "vtls/vtls.h"
#include "http_digest.h"
#include "http_ntlm.h"
#include "curl_ntlm_wb.h"
#include "http_negotiate.h"
#include "url.h"
#include "share.h"
#include "hostip.h"
#include "http.h"
#include "select.h"
#include "parsedate.h" /* for the week day and month names */
#include "strtoofft.h"
#include "multiif.h"
#include "strcase.h"
#include "content_encoding.h"
#include "http_proxy.h"
#include "warnless.h"
#include "non-ascii.h"
#include "conncache.h"
#include "pipeline.h"
#include "http2.h"
#include "connect.h"
#include "strdup.h"

/* The last 3 #include files should be in this order */
#include "curl_printf.h"
#include "curl_memory.h"
#include "memdebug.h"

/*
 * Forward declarations.
 */

static int http_getsock_do(struct connectdata *conn,
                           curl_socket_t *socks,
                           int numsocks);
static int http_should_fail(struct connectdata *conn);

#ifdef USE_SSL
static CURLcode https_connecting(struct connectdata *conn, bool *done);
static int https_getsock(struct connectdata *conn,
                         curl_socket_t *socks,
                         int numsocks);
#else
#define https_connecting(x,y) CURLE_COULDNT_CONNECT
#endif

/*
 * HTTP handler interface.
 */
const struct Curl_handler Curl_handler_http = {
  "HTTP",                               /* scheme */
  Curl_http_setup_conn,                 /* setup_connection */
  Curl_http,                            /* do_it */
  Curl_http_done,                       /* done */
  ZERO_NULL,                            /* do_more */
  Curl_http_connect,                    /* connect_it */
  ZERO_NULL,                            /* connecting */
  ZERO_NULL,                            /* doing */
  ZERO_NULL,                            /* proto_getsock */
  http_getsock_do,                      /* doing_getsock */
  ZERO_NULL,                            /* domore_getsock */
  ZERO_NULL,                            /* perform_getsock */
  ZERO_NULL,                            /* disconnect */
  ZERO_NULL,                            /* readwrite */
  ZERO_NULL,                            /* connection_check */
  PORT_HTTP,                            /* defport */
  CURLPROTO_HTTP,                       /* protocol */
  PROTOPT_CREDSPERREQUEST               /* flags */
};

#ifdef USE_SSL
/*
 * HTTPS handler interface.
 */
const struct Curl_handler Curl_handler_https = {
  "HTTPS",                              /* scheme */
  Curl_http_setup_conn,                 /* setup_connection */
  Curl_http,                            /* do_it */
  Curl_http_done,                       /* done */
  ZERO_NULL,                            /* do_more */
  Curl_http_connect,                    /* connect_it */
  https_connecting,                     /* connecting */
  ZERO_NULL,                            /* doing */
  https_getsock,                        /* proto_getsock */
  http_getsock_do,                      /* doing_getsock */
  ZERO_NULL,                            /* domore_getsock */
  ZERO_NULL,                            /* perform_getsock */
  ZERO_NULL,                            /* disconnect */
  ZERO_NULL,                            /* readwrite */
  ZERO_NULL,                            /* connection_check */
  PORT_HTTPS,                           /* defport */
  CURLPROTO_HTTPS,                      /* protocol */
  PROTOPT_SSL | PROTOPT_CREDSPERREQUEST | PROTOPT_ALPN_NPN /* flags */
};
#endif

CURLcode Curl_http_setup_conn(struct connectdata *conn)
{
  /* allocate the HTTP-specific struct for the Curl_easy, only to survive
     during this request */
  struct HTTP *http;
  DEBUGASSERT(conn->data->req.protop == NULL);

  http = calloc(1, sizeof(struct HTTP));
  if(!http)
    return CURLE_OUT_OF_MEMORY;

  Curl_mime_initpart(&http->form, conn->data);
  conn->data->req.protop = http;

  Curl_http2_setup_conn(conn);
  Curl_http2_setup_req(conn->data);

  return CURLE_OK;
}


/*
 * checkProxyHeaders() checks the linked list of custom proxy headers
 * if proxy headers are not available, then it will lookup into http header
 * link list
 *
 * It takes a connectdata struct as input instead of the Curl_easy simply
 * to know if this is a proxy request or not, as it then might check a
 * different header list.
 */
char *Curl_checkProxyheaders(const struct connectdata *conn,
                             const char *thisheader)
{
  struct curl_slist *head;
  size_t thislen = strlen(thisheader);
  struct Curl_easy *data = conn->data;

  for(head = (conn->bits.proxy && data->set.sep_headers) ?
        data->set.proxyheaders : data->set.headers;
      head; head = head->next) {
    if(strncasecompare(head->data, thisheader, thislen))
      return head->data;
  }

  return NULL;
}

/*
 * Strip off leading and trailing whitespace from the value in the
 * given HTTP header line and return a strdupped copy. Returns NULL in
 * case of allocation failure. Returns an empty string if the header value
 * consists entirely of whitespace.
 */
char *Curl_copy_header_value(const char *header)
{
  const char *start;
  const char *end;
  char *value;
  size_t len;

  DEBUGASSERT(header);

  /* Find the end of the header name */
  while(*header && (*header != ':'))
    ++header;

  if(*header)
    /* Skip over colon */
    ++header;

  /* Find the first non-space letter */
  start = header;
  while(*start && ISSPACE(*start))
    start++;

  /* data is in the host encoding so
     use '\r' and '\n' instead of 0x0d and 0x0a */
  end = strchr(start, '\r');
  if(!end)
    end = strchr(start, '\n');
  if(!end)
    end = strchr(start, '\0');
  if(!end)
    return NULL;

  /* skip all trailing space letters */
  while((end > start) && ISSPACE(*end))
    end--;

  /* get length of the type */
  len = end - start + 1;

  value = malloc(len + 1);
  if(!value)
    return NULL;

  memcpy(value, start, len);
  value[len] = 0; /* zero terminate */

  return value;
}

/*
 * http_output_basic() sets up an Authorization: header (or the proxy version)
 * for HTTP Basic authentication.
 *
 * Returns CURLcode.
 */
static CURLcode http_output_basic(struct connectdata *conn, bool proxy)
{
  size_t size = 0;
  char *authorization = NULL;
  struct Curl_easy *data = conn->data;
  char **userp;
  const char *user;
  const char *pwd;
  CURLcode result;
  char *out;

  if(proxy) {
    userp = &conn->allocptr.proxyuserpwd;
    user = conn->http_proxy.user;
    pwd = conn->http_proxy.passwd;
  }
  else {
    userp = &conn->allocptr.userpwd;
    user = conn->user;
    pwd = conn->passwd;
  }

  out = aprintf("%s:%s", user, pwd);
  if(!out)
    return CURLE_OUT_OF_MEMORY;

  result = Curl_base64_encode(data, out, strlen(out), &authorization, &size);
  if(result)
    goto fail;

  if(!authorization) {
    result = CURLE_REMOTE_ACCESS_DENIED;
    goto fail;
  }

  free(*userp);
  *userp = aprintf("%sAuthorization: Basic %s\r\n",
                   proxy ? "Proxy-" : "",
                   authorization);
  free(authorization);
  if(!*userp) {
    result = CURLE_OUT_OF_MEMORY;
    goto fail;
  }

  fail:
  free(out);
  return result;
}

/* pickoneauth() selects the most favourable authentication method from the
 * ones available and the ones we want.
 *
 * return TRUE if one was picked
 */
static bool pickoneauth(struct auth *pick)
{
  bool picked;
  /* only deal with authentication we want */
  unsigned long avail = pick->avail & pick->want;
  picked = TRUE;

  /* The order of these checks is highly relevant, as this will be the order
     of preference in case of the existence of multiple accepted types. */
  if(avail & CURLAUTH_NEGOTIATE)
    pick->picked = CURLAUTH_NEGOTIATE;
  else if(avail & CURLAUTH_DIGEST)
    pick->picked = CURLAUTH_DIGEST;
  else if(avail & CURLAUTH_NTLM)
    pick->picked = CURLAUTH_NTLM;
  else if(avail & CURLAUTH_NTLM_WB)
    pick->picked = CURLAUTH_NTLM_WB;
  else if(avail & CURLAUTH_BASIC)
    pick->picked = CURLAUTH_BASIC;
  else {
    pick->picked = CURLAUTH_PICKNONE; /* we select to use nothing */
    picked = FALSE;
  }
  pick->avail = CURLAUTH_NONE; /* clear it here */

  return picked;
}

/*
 * Curl_http_perhapsrewind()
 *
 * If we are doing POST or PUT {
 *   If we have more data to send {
 *     If we are doing NTLM {
 *       Keep sending since we must not disconnect
 *     }
 *     else {
 *       If there is more than just a little data left to send, close
 *       the current connection by force.
 *     }
 *   }
 *   If we have sent any data {
 *     If we don't have track of all the data {
 *       call app to tell it to rewind
 *     }
 *     else {
 *       rewind internally so that the operation can restart fine
 *     }
 *   }
 * }
 */
static CURLcode http_perhapsrewind(struct connectdata *conn)
{
  struct Curl_easy *data = conn->data;
  struct HTTP *http = data->req.protop;
  curl_off_t bytessent;
  curl_off_t expectsend = -1; /* default is unknown */

  if(!http)
    /* If this is still NULL, we have not reach very far and we can safely
       skip this rewinding stuff */
    return CURLE_OK;

  switch(data->set.httpreq) {
  case HTTPREQ_GET:
  case HTTPREQ_HEAD:
    return CURLE_OK;
  default:
    break;
  }

  bytessent = http->writebytecount;

  if(conn->bits.authneg) {
    /* This is a state where we are known to be negotiating and we don't send
       any data then. */
    expectsend = 0;
  }
  else if(!conn->bits.protoconnstart) {
    /* HTTP CONNECT in progress: there is no body */
    expectsend = 0;
  }
  else {
    /* figure out how much data we are expected to send */
    switch(data->set.httpreq) {
    case HTTPREQ_POST:
      if(data->state.infilesize != -1)
        expectsend = data->state.infilesize;
      break;
    case HTTPREQ_PUT:
      if(data->state.infilesize != -1)
        expectsend = data->state.infilesize;
      break;
    case HTTPREQ_POST_FORM:
    case HTTPREQ_POST_MIME:
      expectsend = http->postsize;
      break;
    default:
      break;
    }
  }

  conn->bits.rewindaftersend = FALSE; /* default */

  if((expectsend == -1) || (expectsend > bytessent)) {
#if defined(USE_NTLM)
    /* There is still data left to send */
    if((data->state.authproxy.picked == CURLAUTH_NTLM) ||
       (data->state.authhost.picked == CURLAUTH_NTLM) ||
       (data->state.authproxy.picked == CURLAUTH_NTLM_WB) ||
       (data->state.authhost.picked == CURLAUTH_NTLM_WB)) {
      if(((expectsend - bytessent) < 2000) ||
         (conn->ntlm.state != NTLMSTATE_NONE) ||
         (conn->proxyntlm.state != NTLMSTATE_NONE)) {
        /* The NTLM-negotiation has started *OR* there is just a little (<2K)
           data left to send, keep on sending. */

        /* rewind data when completely done sending! */
        if(!conn->bits.authneg) {
          conn->bits.rewindaftersend = TRUE;
          infof(data, "Rewind stream after send\n");
        }

        return CURLE_OK;
      }

      if(conn->bits.close)
        /* this is already marked to get closed */
        return CURLE_OK;

      infof(data, "NTLM send, close instead of sending %"
            CURL_FORMAT_CURL_OFF_T " bytes\n",
            (curl_off_t)(expectsend - bytessent));
    }
#endif

    /* This is not NTLM or many bytes left to send: close */
    streamclose(conn, "Mid-auth HTTP and much data left to send");
    data->req.size = 0; /* don't download any more than 0 bytes */

    /* There still is data left to send, but this connection is marked for
       closure so we can safely do the rewind right now */
  }

  if(bytessent)
    /* we rewind now at once since if we already sent something */
    return Curl_readrewind(conn);

  return CURLE_OK;
}

/*
 * Curl_http_auth_act() gets called when all HTTP headers have been received
 * and it checks what authentication methods that are available and decides
 * which one (if any) to use. It will set 'newurl' if an auth method was
 * picked.
 */

CURLcode Curl_http_auth_act(struct connectdata *conn)
{
  struct Curl_easy *data = conn->data;
  bool pickhost = FALSE;
  bool pickproxy = FALSE;
  CURLcode result = CURLE_OK;

  if(100 <= data->req.httpcode && 199 >= data->req.httpcode)
    /* this is a transient response code, ignore */
    return CURLE_OK;

  if(data->state.authproblem)
    return data->set.http_fail_on_error?CURLE_HTTP_RETURNED_ERROR:CURLE_OK;

  if(conn->bits.user_passwd &&
     ((data->req.httpcode == 401) ||
      (conn->bits.authneg && data->req.httpcode < 300))) {
    pickhost = pickoneauth(&data->state.authhost);
    if(!pickhost)
      data->state.authproblem = TRUE;
  }
  if(conn->bits.proxy_user_passwd &&
     ((data->req.httpcode == 407) ||
      (conn->bits.authneg && data->req.httpcode < 300))) {
    pickproxy = pickoneauth(&data->state.authproxy);
    if(!pickproxy)
      data->state.authproblem = TRUE;
  }

  if(pickhost || pickproxy) {
    /* In case this is GSS auth, the newurl field is already allocated so
       we must make sure to free it before allocating a new one. As figured
       out in bug #2284386 */
    Curl_safefree(data->req.newurl);
    data->req.newurl = strdup(data->change.url); /* clone URL */
    if(!data->req.newurl)
      return CURLE_OUT_OF_MEMORY;

    if((data->set.httpreq != HTTPREQ_GET) &&
       (data->set.httpreq != HTTPREQ_HEAD) &&
       !conn->bits.rewindaftersend) {
      result = http_perhapsrewind(conn);
      if(result)
        return result;
    }
  }
  else if((data->req.httpcode < 300) &&
          (!data->state.authhost.done) &&
          conn->bits.authneg) {
    /* no (known) authentication available,
       authentication is not "done" yet and
       no authentication seems to be required and
       we didn't try HEAD or GET */
    if((data->set.httpreq != HTTPREQ_GET) &&
       (data->set.httpreq != HTTPREQ_HEAD)) {
      data->req.newurl = strdup(data->change.url); /* clone URL */
      if(!data->req.newurl)
        return CURLE_OUT_OF_MEMORY;
      data->state.authhost.done = TRUE;
    }
  }
  if(http_should_fail(conn)) {
    failf(data, "The requested URL returned error: %d",
          data->req.httpcode);
    result = CURLE_HTTP_RETURNED_ERROR;
  }

  return result;
}

/*
 * Output the correct authentication header depending on the auth type
 * and whether or not it is to a proxy.
 */
static CURLcode
output_auth_headers(struct connectdata *conn,
                    struct auth *authstatus,
                    const char *request,
                    const char *path,
                    bool proxy)
{
  const char *auth = NULL;
  CURLcode result = CURLE_OK;
#if !defined(CURL_DISABLE_VERBOSE_STRINGS) || defined(USE_SPNEGO)
  struct Curl_easy *data = conn->data;
#endif
#ifdef USE_SPNEGO
  struct negotiatedata *negdata = proxy ?
    &data->state.proxyneg : &data->state.negotiate;
#endif

#ifdef CURL_DISABLE_CRYPTO_AUTH
  (void)request;
  (void)path;
#endif

#ifdef USE_SPNEGO
  negdata->state = GSS_AUTHNONE;
  if((authstatus->picked == CURLAUTH_NEGOTIATE) &&
     negdata->context && !GSS_ERROR(negdata->status)) {
    auth = "Negotiate";
    result = Curl_output_negotiate(conn, proxy);
    if(result)
      return result;
    authstatus->done = TRUE;
    negdata->state = GSS_AUTHSENT;
  }
  else
#endif
#ifdef USE_NTLM
  if(authstatus->picked == CURLAUTH_NTLM) {
    auth = "NTLM";
    result = Curl_output_ntlm(conn, proxy);
    if(result)
      return result;
  }
  else
#endif
#if defined(USE_NTLM) && defined(NTLM_WB_ENABLED)
  if(authstatus->picked == CURLAUTH_NTLM_WB) {
    auth = "NTLM_WB";
    result = Curl_output_ntlm_wb(conn, proxy);
    if(result)
      return result;
  }
  else
#endif
#ifndef CURL_DISABLE_CRYPTO_AUTH
  if(authstatus->picked == CURLAUTH_DIGEST) {
    auth = "Digest";
    result = Curl_output_digest(conn,
                                proxy,
                                (const unsigned char *)request,
                                (const unsigned char *)path);
    if(result)
      return result;
  }
  else
#endif
  if(authstatus->picked == CURLAUTH_BASIC) {
    /* Basic */
    if((proxy && conn->bits.proxy_user_passwd &&
        !Curl_checkProxyheaders(conn, "Proxy-authorization:")) ||
       (!proxy && conn->bits.user_passwd &&
        !Curl_checkheaders(conn, "Authorization:"))) {
      auth = "Basic";
      result = http_output_basic(conn, proxy);
      if(result)
        return result;
    }

    /* NOTE: this function should set 'done' TRUE, as the other auth
       functions work that way */
    authstatus->done = TRUE;
  }

  if(auth) {
    infof(data, "%s auth using %s with user '%s'\n",
          proxy ? "Proxy" : "Server", auth,
          proxy ? (conn->http_proxy.user ? conn->http_proxy.user : "") :
                  (conn->user ? conn->user : ""));
    authstatus->multipass = (!authstatus->done) ? TRUE : FALSE;
  }
  else
    authstatus->multipass = FALSE;

  return CURLE_OK;
}

/**
 * Curl_http_output_auth() setups the authentication headers for the
 * host/proxy and the correct authentication
 * method. conn->data->state.authdone is set to TRUE when authentication is
 * done.
 *
 * @param conn all information about the current connection
 * @param request pointer to the request keyword
 * @param path pointer to the requested path
 * @param proxytunnel boolean if this is the request setting up a "proxy
 * tunnel"
 *
 * @returns CURLcode
 */
CURLcode
Curl_http_output_auth(struct connectdata *conn,
                      const char *request,
                      const char *path,
                      bool proxytunnel) /* TRUE if this is the request setting
                                           up the proxy tunnel */
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;
  struct auth *authhost;
  struct auth *authproxy;

  DEBUGASSERT(data);

  authhost = &data->state.authhost;
  authproxy = &data->state.authproxy;

  if((conn->bits.httpproxy && conn->bits.proxy_user_passwd) ||
     conn->bits.user_passwd)
    /* continue please */;
  else {
    authhost->done = TRUE;
    authproxy->done = TRUE;
    return CURLE_OK; /* no authentication with no user or password */
  }

  if(authhost->want && !authhost->picked)
    /* The app has selected one or more methods, but none has been picked
       so far by a server round-trip. Then we set the picked one to the
       want one, and if this is one single bit it'll be used instantly. */
    authhost->picked = authhost->want;

  if(authproxy->want && !authproxy->picked)
    /* The app has selected one or more methods, but none has been picked so
       far by a proxy round-trip. Then we set the picked one to the want one,
       and if this is one single bit it'll be used instantly. */
    authproxy->picked = authproxy->want;

#ifndef CURL_DISABLE_PROXY
  /* Send proxy authentication header if needed */
  if(conn->bits.httpproxy &&
      (conn->bits.tunnel_proxy == proxytunnel)) {
    result = output_auth_headers(conn, authproxy, request, path, TRUE);
    if(result)
      return result;
  }
  else
#else
  (void)proxytunnel;
#endif /* CURL_DISABLE_PROXY */
    /* we have no proxy so let's pretend we're done authenticating
       with it */
    authproxy->done = TRUE;

  /* To prevent the user+password to get sent to other than the original
     host due to a location-follow, we do some weirdo checks here */
  if(!data->state.this_is_a_follow ||
     conn->bits.netrc ||
     !data->state.first_host ||
     data->set.http_disable_hostname_check_before_authentication ||
     strcasecompare(data->state.first_host, conn->host.name)) {
    result = output_auth_headers(conn, authhost, request, path, FALSE);
  }
  else
    authhost->done = TRUE;

  return result;
}

/*
 * Curl_http_input_auth() deals with Proxy-Authenticate: and WWW-Authenticate:
 * headers. They are dealt with both in the transfer.c main loop and in the
 * proxy CONNECT loop.
 */

CURLcode Curl_http_input_auth(struct connectdata *conn, bool proxy,
                              const char *auth) /* the first non-space */
{
  /*
   * This resource requires authentication
   */
  struct Curl_easy *data = conn->data;

#ifdef USE_SPNEGO
  struct negotiatedata *negdata = proxy?
    &data->state.proxyneg:&data->state.negotiate;
#endif
  unsigned long *availp;
  struct auth *authp;

  if(proxy) {
    availp = &data->info.proxyauthavail;
    authp = &data->state.authproxy;
  }
  else {
    availp = &data->info.httpauthavail;
    authp = &data->state.authhost;
  }

  /*
   * Here we check if we want the specific single authentication (using ==) and
   * if we do, we initiate usage of it.
   *
   * If the provided authentication is wanted as one out of several accepted
   * types (using &), we OR this authentication type to the authavail
   * variable.
   *
   * Note:
   *
   * ->picked is first set to the 'want' value (one or more bits) before the
   * request is sent, and then it is again set _after_ all response 401/407
   * headers have been received but then only to a single preferred method
   * (bit).
   */

  while(*auth) {
#ifdef USE_SPNEGO
    if(checkprefix("Negotiate", auth)) {
      if((authp->avail & CURLAUTH_NEGOTIATE) ||
         Curl_auth_is_spnego_supported()) {
        *availp |= CURLAUTH_NEGOTIATE;
        authp->avail |= CURLAUTH_NEGOTIATE;

        if(authp->picked == CURLAUTH_NEGOTIATE) {
          if(negdata->state == GSS_AUTHSENT ||
             negdata->state == GSS_AUTHNONE) {
            CURLcode result = Curl_input_negotiate(conn, proxy, auth);
            if(!result) {
              DEBUGASSERT(!data->req.newurl);
              data->req.newurl = strdup(data->change.url);
              if(!data->req.newurl)
                return CURLE_OUT_OF_MEMORY;
              data->state.authproblem = FALSE;
              /* we received a GSS auth token and we dealt with it fine */
              negdata->state = GSS_AUTHRECV;
            }
            else
              data->state.authproblem = TRUE;
          }
        }
      }
    }
    else
#endif
#ifdef USE_NTLM
      /* NTLM support requires the SSL crypto libs */
      if(checkprefix("NTLM", auth)) {
        if((authp->avail & CURLAUTH_NTLM) ||
           (authp->avail & CURLAUTH_NTLM_WB) ||
           Curl_auth_is_ntlm_supported()) {
          *availp |= CURLAUTH_NTLM;
          authp->avail |= CURLAUTH_NTLM;

          if(authp->picked == CURLAUTH_NTLM ||
             authp->picked == CURLAUTH_NTLM_WB) {
            /* NTLM authentication is picked and activated */
            CURLcode result = Curl_input_ntlm(conn, proxy, auth);
            if(!result) {
              data->state.authproblem = FALSE;
#ifdef NTLM_WB_ENABLED
              if(authp->picked == CURLAUTH_NTLM_WB) {
                *availp &= ~CURLAUTH_NTLM;
                authp->avail &= ~CURLAUTH_NTLM;
                *availp |= CURLAUTH_NTLM_WB;
                authp->avail |= CURLAUTH_NTLM_WB;

                /* Get the challenge-message which will be passed to
                 * ntlm_auth for generating the type 3 message later */
                while(*auth && ISSPACE(*auth))
                  auth++;
                if(checkprefix("NTLM", auth)) {
                  auth += strlen("NTLM");
                  while(*auth && ISSPACE(*auth))
                    auth++;
                  if(*auth) {
                    conn->challenge_header = strdup(auth);
                    if(!conn->challenge_header)
                      return CURLE_OUT_OF_MEMORY;
                  }
                }
              }
#endif
            }
            else {
              infof(data, "Authentication problem. Ignoring this.\n");
              data->state.authproblem = TRUE;
            }
          }
        }
      }
      else
#endif
#ifndef CURL_DISABLE_CRYPTO_AUTH
        if(checkprefix("Digest", auth)) {
          if((authp->avail & CURLAUTH_DIGEST) != 0)
            infof(data, "Ignoring duplicate digest auth header.\n");
          else if(Curl_auth_is_digest_supported()) {
            CURLcode result;

            *availp |= CURLAUTH_DIGEST;
            authp->avail |= CURLAUTH_DIGEST;

            /* We call this function on input Digest headers even if Digest
             * authentication isn't activated yet, as we need to store the
             * incoming data from this header in case we are going to use
             * Digest */
            result = Curl_input_digest(conn, proxy, auth);
            if(result) {
              infof(data, "Authentication problem. Ignoring this.\n");
              data->state.authproblem = TRUE;
            }
          }
        }
        else
#endif
          if(checkprefix("Basic", auth)) {
            *availp |= CURLAUTH_BASIC;
            authp->avail |= CURLAUTH_BASIC;
            if(authp->picked == CURLAUTH_BASIC) {
              /* We asked for Basic authentication but got a 40X back
                 anyway, which basically means our name+password isn't
                 valid. */
              authp->avail = CURLAUTH_NONE;
              infof(data, "Authentication problem. Ignoring this.\n");
              data->state.authproblem = TRUE;
            }
          }

    /* there may be multiple methods on one line, so keep reading */
    while(*auth && *auth != ',') /* read up to the next comma */
      auth++;
    if(*auth == ',') /* if we're on a comma, skip it */
      auth++;
    while(*auth && ISSPACE(*auth))
      auth++;
  }

  return CURLE_OK;
}

/**
 * http_should_fail() determines whether an HTTP response has gotten us
 * into an error state or not.
 *
 * @param conn all information about the current connection
 *
 * @retval 0 communications should continue
 *
 * @retval 1 communications should not continue
 */
static int http_should_fail(struct connectdata *conn)
{
  struct Curl_easy *data;
  int httpcode;

  DEBUGASSERT(conn);
  data = conn->data;
  DEBUGASSERT(data);

  httpcode = data->req.httpcode;

  /*
  ** If we haven't been asked to fail on error,
  ** don't fail.
  */
  if(!data->set.http_fail_on_error)
    return 0;

  /*
  ** Any code < 400 is never terminal.
  */
  if(httpcode < 400)
    return 0;

  /*
  ** Any code >= 400 that's not 401 or 407 is always
  ** a terminal error
  */
  if((httpcode != 401) && (httpcode != 407))
    return 1;

  /*
  ** All we have left to deal with is 401 and 407
  */
  DEBUGASSERT((httpcode == 401) || (httpcode == 407));

  /*
  ** Examine the current authentication state to see if this
  ** is an error.  The idea is for this function to get
  ** called after processing all the headers in a response
  ** message.  So, if we've been to asked to authenticate a
  ** particular stage, and we've done it, we're OK.  But, if
  ** we're already completely authenticated, it's not OK to
  ** get another 401 or 407.
  **
  ** It is possible for authentication to go stale such that
  ** the client needs to reauthenticate.  Once that info is
  ** available, use it here.
  */

  /*
  ** Either we're not authenticating, or we're supposed to
  ** be authenticating something else.  This is an error.
  */
  if((httpcode == 401) && !conn->bits.user_passwd)
    return TRUE;
  if((httpcode == 407) && !conn->bits.proxy_user_passwd)
    return TRUE;

  return data->state.authproblem;
}

/*
 * readmoredata() is a "fread() emulation" to provide POST and/or request
 * data. It is used when a huge POST is to be made and the entire chunk wasn't
 * sent in the first send(). This function will then be called from the
 * transfer.c loop when more data is to be sent to the peer.
 *
 * Returns the amount of bytes it filled the buffer with.
 */
static size_t readmoredata(char *buffer,
                           size_t size,
                           size_t nitems,
                           void *userp)
{
  struct connectdata *conn = (struct connectdata *)userp;
  struct HTTP *http = conn->data->req.protop;
  size_t fullsize = size * nitems;

  if(!http->postsize)
    /* nothing to return */
    return 0;

  /* make sure that a HTTP request is never sent away chunked! */
  conn->data->req.forbidchunk = (http->sending == HTTPSEND_REQUEST)?TRUE:FALSE;

  if(http->postsize <= (curl_off_t)fullsize) {
    memcpy(buffer, http->postdata, (size_t)http->postsize);
    fullsize = (size_t)http->postsize;

    if(http->backup.postsize) {
      /* move backup data into focus and continue on that */
      http->postdata = http->backup.postdata;
      http->postsize = http->backup.postsize;
      conn->data->state.fread_func = http->backup.fread_func;
      conn->data->state.in = http->backup.fread_in;

      http->sending++; /* move one step up */

      http->backup.postsize = 0;
    }
    else
      http->postsize = 0;

    return fullsize;
  }

  memcpy(buffer, http->postdata, fullsize);
  http->postdata += fullsize;
  http->postsize -= fullsize;

  return fullsize;
}

/* ------------------------------------------------------------------------- */
/* add_buffer functions */

/*
 * Curl_add_buffer_init() sets up and returns a fine buffer struct
 */
Curl_send_buffer *Curl_add_buffer_init(void)
{
  return calloc(1, sizeof(Curl_send_buffer));
}

/*
 * Curl_add_buffer_free() frees all associated resources.
 */
void Curl_add_buffer_free(Curl_send_buffer *buff)
{
  if(buff) /* deal with NULL input */
    free(buff->buffer);
  free(buff);
}

/*
 * Curl_add_buffer_send() sends a header buffer and frees all associated
 * memory.  Body data may be appended to the header data if desired.
 *
 * Returns CURLcode
 */
CURLcode Curl_add_buffer_send(Curl_send_buffer *in,
                              struct connectdata *conn,

                               /* add the number of sent bytes to this
                                  counter */
                              long *bytes_written,

                               /* how much of the buffer contains body data */
                              size_t included_body_bytes,
                              int socketindex)

{
  ssize_t amount;
  CURLcode result;
  char *ptr;
  size_t size;
  struct HTTP *http = conn->data->req.protop;
  size_t sendsize;
  curl_socket_t sockfd;
  size_t headersize;

  DEBUGASSERT(socketindex <= SECONDARYSOCKET);

  sockfd = conn->sock[socketindex];

  /* The looping below is required since we use non-blocking sockets, but due
     to the circumstances we will just loop and try again and again etc */

  ptr = in->buffer;
  size = in->size_used;

  headersize = size - included_body_bytes; /* the initial part that isn't body
                                              is header */

  DEBUGASSERT(size > included_body_bytes);

  result = Curl_convert_to_network(conn->data, ptr, headersize);
  /* Curl_convert_to_network calls failf if unsuccessful */
  if(result) {
    /* conversion failed, free memory and return to the caller */
    Curl_add_buffer_free(in);
    return result;
  }

  if((conn->handler->flags & PROTOPT_SSL ||
     conn->http_proxy.proxytype == CURLPROXY_HTTPS)
     && conn->httpversion != 20) {
    /* We never send more than CURL_MAX_WRITE_SIZE bytes in one single chunk
       when we speak HTTPS, as if only a fraction of it is sent now, this data
       needs to fit into the normal read-callback buffer later on and that
       buffer is using this size.
    */

    sendsize = CURLMIN(size, CURL_MAX_WRITE_SIZE);

    /* OpenSSL is very picky and we must send the SAME buffer pointer to the
       library when we attempt to re-send this buffer. Sending the same data
       is not enough, we must use the exact same address. For this reason, we
       must copy the data to the uploadbuffer first, since that is the buffer
       we will be using if this send is retried later.
    */
    memcpy(conn->data->state.uploadbuffer, ptr, sendsize);
    ptr = conn->data->state.uploadbuffer;
  }
  else
    sendsize = size;

  result = Curl_write(conn, sockfd, ptr, sendsize, &amount);

  if(!result) {
    /*
     * Note that we may not send the entire chunk at once, and we have a set
     * number of data bytes at the end of the big buffer (out of which we may
     * only send away a part).
     */
    /* how much of the header that was sent */
    size_t headlen = (size_t)amount>headersize ? headersize : (size_t)amount;
    size_t bodylen = amount - headlen;

    if(conn->data->set.verbose) {
      /* this data _may_ contain binary stuff */
      Curl_debug(conn->data, CURLINFO_HEADER_OUT, ptr, headlen, conn);
      if(bodylen) {
        /* there was body data sent beyond the initial header part, pass that
           on to the debug callback too */
        Curl_debug(conn->data, CURLINFO_DATA_OUT,
                   ptr + headlen, bodylen, conn);
      }
    }

    /* 'amount' can never be a very large value here so typecasting it so a
       signed 31 bit value should not cause problems even if ssize_t is
       64bit */
    *bytes_written += (long)amount;

    if(http) {
      /* if we sent a piece of the body here, up the byte counter for it
         accordingly */
      http->writebytecount += bodylen;

      if((size_t)amount != size) {
        /* The whole request could not be sent in one system call. We must
           queue it up and send it later when we get the chance. We must not
           loop here and wait until it might work again. */

        size -= amount;

        ptr = in->buffer + amount;

        /* backup the currently set pointers */
        http->backup.fread_func = conn->data->state.fread_func;
        http->backup.fread_in = conn->data->state.in;
        http->backup.postdata = http->postdata;
        http->backup.postsize = http->postsize;

        /* set the new pointers for the request-sending */
        conn->data->state.fread_func = (curl_read_callback)readmoredata;
        conn->data->state.in = (void *)conn;
        http->postdata = ptr;
        http->postsize = (curl_off_t)size;

        http->send_buffer = in;
        http->sending = HTTPSEND_REQUEST;

        return CURLE_OK;
      }
      http->sending = HTTPSEND_BODY;
      /* the full buffer was sent, clean up and return */
    }
    else {
      if((size_t)amount != size)
        /* We have no continue-send mechanism now, fail. This can only happen
           when this function is used from the CONNECT sending function. We
           currently (stupidly) assume that the whole request is always sent
           away in the first single chunk.

           This needs FIXing.
        */
        return CURLE_SEND_ERROR;
      Curl_pipeline_leave_write(conn);
    }
  }
  Curl_add_buffer_free(in);

  return result;
}


/*
 * add_bufferf() add the formatted input to the buffer.
 */
CURLcode Curl_add_bufferf(Curl_send_buffer *in, const char *fmt, ...)
{
  char *s;
  va_list ap;
  va_start(ap, fmt);
  s = vaprintf(fmt, ap); /* this allocs a new string to append */
  va_end(ap);

  if(s) {
    CURLcode result = Curl_add_buffer(in, s, strlen(s));
    free(s);
    return result;
  }
  /* If we failed, we cleanup the whole buffer and return error */
  free(in->buffer);
  free(in);
  return CURLE_OUT_OF_MEMORY;
}

/*
 * add_buffer() appends a memory chunk to the existing buffer
 */
CURLcode Curl_add_buffer(Curl_send_buffer *in, const void *inptr, size_t size)
{
  char *new_rb;
  size_t new_size;

  if(~size < in->size_used) {
    /* If resulting used size of send buffer would wrap size_t, cleanup
       the whole buffer and return error. Otherwise the required buffer
       size will fit into a single allocatable memory chunk */
    Curl_safefree(in->buffer);
    free(in);
    return CURLE_OUT_OF_MEMORY;
  }

  if(!in->buffer ||
     ((in->size_used + size) > (in->size_max - 1))) {

    /* If current buffer size isn't enough to hold the result, use a
       buffer size that doubles the required size. If this new size
       would wrap size_t, then just use the largest possible one */

    if((size > (size_t)-1 / 2) || (in->size_used > (size_t)-1 / 2) ||
       (~(size * 2) < (in->size_used * 2)))
      new_size = (size_t)-1;
    else
      new_size = (in->size_used + size) * 2;

    if(in->buffer)
      /* we have a buffer, enlarge the existing one */
      new_rb = Curl_saferealloc(in->buffer, new_size);
    else
      /* create a new buffer */
      new_rb = malloc(new_size);

    if(!new_rb) {
      /* If we failed, we cleanup the whole buffer and return error */
      free(in);
      return CURLE_OUT_OF_MEMORY;
    }

    in->buffer = new_rb;
    in->size_max = new_size;
  }
  memcpy(&in->buffer[in->size_used], inptr, size);

  in->size_used += size;

  return CURLE_OK;
}

/* end of the add_buffer functions */
/* ------------------------------------------------------------------------- */



/*
 * Curl_compareheader()
 *
 * Returns TRUE if 'headerline' contains the 'header' with given 'content'.
 * Pass headers WITH the colon.
 */
bool
Curl_compareheader(const char *headerline, /* line to check */
                   const char *header,  /* header keyword _with_ colon */
                   const char *content) /* content string to find */
{
  /* RFC2616, section 4.2 says: "Each header field consists of a name followed
   * by a colon (":") and the field value. Field names are case-insensitive.
   * The field value MAY be preceded by any amount of LWS, though a single SP
   * is preferred." */

  size_t hlen = strlen(header);
  size_t clen;
  size_t len;
  const char *start;
  const char *end;

  if(!strncasecompare(headerline, header, hlen))
    return FALSE; /* doesn't start with header */

  /* pass the header */
  start = &headerline[hlen];

  /* pass all white spaces */
  while(*start && ISSPACE(*start))
    start++;

  /* find the end of the header line */
  end = strchr(start, '\r'); /* lines end with CRLF */
  if(!end) {
    /* in case there's a non-standard compliant line here */
    end = strchr(start, '\n');

    if(!end)
      /* hm, there's no line ending here, use the zero byte! */
      end = strchr(start, '\0');
  }

  len = end-start; /* length of the content part of the input line */
  clen = strlen(content); /* length of the word to find */

  /* find the content string in the rest of the line */
  for(; len >= clen; len--, start++) {
    if(strncasecompare(start, content, clen))
      return TRUE; /* match! */
  }

  return FALSE; /* no match */
}

/*
 * Curl_http_connect() performs HTTP stuff to do at connect-time, called from
 * the generic Curl_connect().
 */
CURLcode Curl_http_connect(struct connectdata *conn, bool *done)
{
  CURLcode result;

  /* We default to persistent connections. We set this already in this connect
     function to make the re-use checks properly be able to check this bit. */
  connkeep(conn, "HTTP default");

  /* the CONNECT procedure might not have been completed */
  result = Curl_proxy_connect(conn, FIRSTSOCKET);
  if(result)
    return result;

  if(conn->bits.proxy_connect_closed)
    /* this is not an error, just part of the connection negotiation */
    return CURLE_OK;

  if(CONNECT_FIRSTSOCKET_PROXY_SSL())
    return CURLE_OK; /* wait for HTTPS proxy SSL initialization to complete */

  if(Curl_connect_ongoing(conn))
    /* nothing else to do except wait right now - we're not done here. */
    return CURLE_OK;

  if(conn->given->protocol & CURLPROTO_HTTPS) {
    /* perform SSL initialization */
    result = https_connecting(conn, done);
    if(result)
      return result;
  }
  else
    *done = TRUE;

  return CURLE_OK;
}

/* this returns the socket to wait for in the DO and DOING state for the multi
   interface and then we're always _sending_ a request and thus we wait for
   the single socket to become writable only */
static int http_getsock_do(struct connectdata *conn,
                           curl_socket_t *socks,
                           int numsocks)
{
  /* write mode */
  (void)numsocks; /* unused, we trust it to be at least 1 */
  socks[0] = conn->sock[FIRSTSOCKET];
  return GETSOCK_WRITESOCK(0);
}

#ifdef USE_SSL
static CURLcode https_connecting(struct connectdata *conn, bool *done)
{
  CURLcode result;
  DEBUGASSERT((conn) && (conn->handler->flags & PROTOPT_SSL));

  /* perform SSL initialization for this socket */
  result = Curl_ssl_connect_nonblocking(conn, FIRSTSOCKET, done);
  if(result)
    connclose(conn, "Failed HTTPS connection");

  return result;
}

static int https_getsock(struct connectdata *conn,
                         curl_socket_t *socks,
                         int numsocks)
{
  if(conn->handler->flags & PROTOPT_SSL)
    return Curl_ssl_getsock(conn, socks, numsocks);
  return GETSOCK_BLANK;
}
#endif /* USE_SSL */

/*
 * Curl_http_done() gets called after a single HTTP request has been
 * performed.
 */

CURLcode Curl_http_done(struct connectdata *conn,
                        CURLcode status, bool premature)
{
  struct Curl_easy *data = conn->data;
  struct HTTP *http = data->req.protop;

  /* Clear multipass flag. If authentication isn't done yet, then it will get
   * a chance to be set back to true when we output the next auth header */
  data->state.authhost.multipass = FALSE;
  data->state.authproxy.multipass = FALSE;

  Curl_unencode_cleanup(conn);

#ifdef USE_SPNEGO
  if(data->state.proxyneg.state == GSS_AUTHSENT ||
     data->state.negotiate.state == GSS_AUTHSENT) {
    /* add forbid re-use if http-code != 401/407 as a WA only needed for
     * 401/407 that signal auth failure (empty) otherwise state will be RECV
     * with current code.
     * Do not close CONNECT_ONLY connections. */
    if((data->req.httpcode != 401) && (data->req.httpcode != 407) &&
       !data->set.connect_only)
      streamclose(conn, "Negotiate transfer completed");
    Curl_cleanup_negotiate(data);
  }
#endif

  /* set the proper values (possibly modified on POST) */
  conn->seek_func = data->set.seek_func; /* restore */
  conn->seek_client = data->set.seek_client; /* restore */

  if(!http)
    return CURLE_OK;

  if(http->send_buffer) {
    Curl_add_buffer_free(http->send_buffer);
    http->send_buffer = NULL; /* clear the pointer */
  }

  Curl_http2_done(conn, premature);

  Curl_mime_cleanpart(&http->form);

  switch(data->set.httpreq) {
  case HTTPREQ_PUT:
  case HTTPREQ_POST_FORM:
  case HTTPREQ_POST_MIME:
    data->req.bytecount = http->readbytecount + http->writebytecount;
    break;
  default:
    break;
  }

  if(status)
    return status;

  if(!premature && /* this check is pointless when DONE is called before the
                      entire operation is complete */
     !conn->bits.retry &&
     !data->set.connect_only &&
     (http->readbytecount +
      data->req.headerbytecount -
      data->req.deductheadercount) <= 0) {
    /* If this connection isn't simply closed to be retried, AND nothing was
       read from the HTTP server (that counts), this can't be right so we
       return an error here */
    failf(data, "Empty reply from server");
    return CURLE_GOT_NOTHING;
  }

  return CURLE_OK;
}

/*
 * Determine if we should use HTTP 1.1 (OR BETTER) for this request. Reasons
 * to avoid it include:
 *
 * - if the user specifically requested HTTP 1.0
 * - if the server we are connected to only supports 1.0
 * - if any server previously contacted to handle this request only supports
 * 1.0.
 */
static bool use_http_1_1plus(const struct Curl_easy *data,
                             const struct connectdata *conn)
{
  if((data->state.httpversion == 10) || (conn->httpversion == 10))
    return FALSE;
  if((data->set.httpversion == CURL_HTTP_VERSION_1_0) &&
     (conn->httpversion <= 10))
    return FALSE;
  return ((data->set.httpversion == CURL_HTTP_VERSION_NONE) ||
          (data->set.httpversion >= CURL_HTTP_VERSION_1_1));
}

static const char *get_http_string(const struct Curl_easy *data,
                                   const struct connectdata *conn)
{
#ifdef USE_NGHTTP2
  if(conn->proto.httpc.h2)
    return "2";
#endif

  if(use_http_1_1plus(data, conn))
    return "1.1";

  return "1.0";
}

/* check and possibly add an Expect: header */
static CURLcode expect100(struct Curl_easy *data,
                          struct connectdata *conn,
                          Curl_send_buffer *req_buffer)
{
  CURLcode result = CURLE_OK;
  const char *ptr;
  data->state.expect100header = FALSE; /* default to false unless it is set
                                          to TRUE below */
  if(use_http_1_1plus(data, conn) &&
     (conn->httpversion != 20)) {
    /* if not doing HTTP 1.0 or version 2, or disabled explicitly, we add an
       Expect: 100-continue to the headers which actually speeds up post
       operations (as there is one packet coming back from the web server) */
    ptr = Curl_checkheaders(conn, "Expect:");
    if(ptr) {
      data->state.expect100header =
        Curl_compareheader(ptr, "Expect:", "100-continue");
    }
    else {
      result = Curl_add_bufferf(req_buffer,
                         "Expect: 100-continue\r\n");
      if(!result)
        data->state.expect100header = TRUE;
    }
  }

  return result;
}

enum proxy_use {
  HEADER_SERVER,  /* direct to server */
  HEADER_PROXY,   /* regular request to proxy */
  HEADER_CONNECT  /* sending CONNECT to a proxy */
};

CURLcode Curl_add_custom_headers(struct connectdata *conn,
                                 bool is_connect,
                                 Curl_send_buffer *req_buffer)
{
  char *ptr;
  struct curl_slist *h[2];
  struct curl_slist *headers;
  int numlists = 1; /* by default */
  struct Curl_easy *data = conn->data;
  int i;

  enum proxy_use proxy;

  if(is_connect)
    proxy = HEADER_CONNECT;
  else
    proxy = conn->bits.httpproxy && !conn->bits.tunnel_proxy?
      HEADER_PROXY:HEADER_SERVER;

  switch(proxy) {
  case HEADER_SERVER:
    h[0] = data->set.headers;
    break;
  case HEADER_PROXY:
    h[0] = data->set.headers;
    if(data->set.sep_headers) {
      h[1] = data->set.proxyheaders;
      numlists++;
    }
    break;
  case HEADER_CONNECT:
    if(data->set.sep_headers)
      h[0] = data->set.proxyheaders;
    else
      h[0] = data->set.headers;
    break;
  }

  /* loop through one or two lists */
  for(i = 0; i < numlists; i++) {
    headers = h[i];

    while(headers) {
      ptr = strchr(headers->data, ':');
      if(ptr) {
        /* we require a colon for this to be a true header */

        ptr++; /* pass the colon */
        while(*ptr && ISSPACE(*ptr))
          ptr++;

        if(*ptr) {
          /* only send this if the contents was non-blank */

          if(conn->allocptr.host &&
             /* a Host: header was sent already, don't pass on any custom Host:
                header as that will produce *two* in the same request! */
             checkprefix("Host:", headers->data))
            ;
          else if(data->set.httpreq == HTTPREQ_POST_FORM &&
                  /* this header (extended by formdata.c) is sent later */
                  checkprefix("Content-Type:", headers->data))
            ;
          else if(data->set.httpreq == HTTPREQ_POST_MIME &&
                  /* this header is sent later */
                  checkprefix("Content-Type:", headers->data))
            ;
          else if(conn->bits.authneg &&
                  /* while doing auth neg, don't allow the custom length since
                     we will force length zero then */
                  checkprefix("Content-Length", headers->data))
            ;
          else if(conn->allocptr.te &&
                  /* when asking for Transfer-Encoding, don't pass on a custom
                     Connection: */
                  checkprefix("Connection", headers->data))
            ;
          else if((conn->httpversion == 20) &&
                  checkprefix("Transfer-Encoding:", headers->data))
            /* HTTP/2 doesn't support chunked requests */
            ;
          else {
            CURLcode result = Curl_add_bufferf(req_buffer, "%s\r\n",
                                               headers->data);
            if(result)
              return result;
          }
        }
      }
      else {
        ptr = strchr(headers->data, ';');
        if(ptr) {

          ptr++; /* pass the semicolon */
          while(*ptr && ISSPACE(*ptr))
            ptr++;

          if(*ptr) {
            /* this may be used for something else in the future */
          }
          else {
            if(*(--ptr) == ';') {
              CURLcode result;

              /* send no-value custom header if terminated by semicolon */
              *ptr = ':';
              result = Curl_add_bufferf(req_buffer, "%s\r\n",
                                        headers->data);
              if(result)
                return result;
            }
          }
        }
      }
      headers = headers->next;
    }
  }

  return CURLE_OK;
}

CURLcode Curl_add_timecondition(struct Curl_easy *data,
                                Curl_send_buffer *req_buffer)
{
  const struct tm *tm;
  struct tm keeptime;
  CURLcode result;
  char datestr[80];
  const char *condp;

  if(data->set.timecondition == CURL_TIMECOND_NONE)
    /* no condition was asked for */
    return CURLE_OK;

  result = Curl_gmtime(data->set.timevalue, &keeptime);
  if(result) {
    failf(data, "Invalid TIMEVALUE");
    return result;
  }
  tm = &keeptime;

  switch(data->set.timecondition) {
  default:
    return CURLE_BAD_FUNCTION_ARGUMENT;

  case CURL_TIMECOND_IFMODSINCE:
    condp = "If-Modified-Since";
    break;
  case CURL_TIMECOND_IFUNMODSINCE:
    condp = "If-Unmodified-Since";
    break;
  case CURL_TIMECOND_LASTMOD:
    condp = "Last-Modified";
    break;
  }

  /* The If-Modified-Since header family should have their times set in
   * GMT as RFC2616 defines: "All HTTP date/time stamps MUST be
   * represented in Greenwich Mean Time (GMT), without exception. For the
   * purposes of HTTP, GMT is exactly equal to UTC (Coordinated Universal
   * Time)." (see page 20 of RFC2616).
   */

  /* format: "Tue, 15 Nov 1994 12:45:26 GMT" */
  snprintf(datestr, sizeof(datestr),
           "%s: %s, %02d %s %4d %02d:%02d:%02d GMT\r\n",
           condp,
           Curl_wkday[tm->tm_wday?tm->tm_wday-1:6],
           tm->tm_mday,
           Curl_month[tm->tm_mon],
           tm->tm_year + 1900,
           tm->tm_hour,
           tm->tm_min,
           tm->tm_sec);

  result = Curl_add_buffer(req_buffer, datestr, strlen(datestr));

  return result;
}

/*
 * Curl_http() gets called from the generic multi_do() function when a HTTP
 * request is to be performed. This creates and sends a properly constructed
 * HTTP request.
 */
CURLcode Curl_http(struct connectdata *conn, bool *done)
{
  struct Curl_easy *data = conn->data;
  CURLcode result = CURLE_OK;
  struct HTTP *http;
  const char *ppath = data->state.path;
  bool paste_ftp_userpwd = FALSE;
  char ftp_typecode[sizeof("/;type=?")] = "";
  const char *host = conn->host.name;
  const char *te = ""; /* transfer-encoding */
  const char *ptr;
  const char *request;
  Curl_HttpReq httpreq = data->set.httpreq;
#if !defined(CURL_DISABLE_COOKIES)
  char *addcookies = NULL;
#endif
  curl_off_t included_body = 0;
  const char *httpstring;
  Curl_send_buffer *req_buffer;
  curl_off_t postsize = 0; /* curl_off_t to handle large file sizes */
  int seekerr = CURL_SEEKFUNC_CANTSEEK;

  /* Always consider the DO phase done after this function call, even if there
     may be parts of the request that is not yet sent, since we can deal with
     the rest of the request in the PERFORM phase. */
  *done = TRUE;

  if(conn->httpversion < 20) { /* unless the connection is re-used and already
                                  http2 */
    switch(conn->negnpn) {
    case CURL_HTTP_VERSION_2:
      conn->httpversion = 20; /* we know we're on HTTP/2 now */

      result = Curl_http2_switched(conn, NULL, 0);
      if(result)
        return result;
      break;
    case CURL_HTTP_VERSION_1_1:
      /* continue with HTTP/1.1 when explicitly requested */
      break;
    default:
      /* Check if user wants to use HTTP/2 with clear TCP*/
#ifdef USE_NGHTTP2
      if(conn->data->set.httpversion ==
         CURL_HTTP_VERSION_2_PRIOR_KNOWLEDGE) {
        DEBUGF(infof(data, "HTTP/2 over clean TCP\n"));
        conn->httpversion = 20;

        result = Curl_http2_switched(conn, NULL, 0);
        if(result)
          return result;
      }
#endif
      break;
    }
  }
  else {
    /* prepare for a http2 request */
    result = Curl_http2_setup(conn);
    if(result)
      return result;
  }

  http = data->req.protop;

  if(!data->state.this_is_a_follow) {
    /* Free to avoid leaking memory on multiple requests*/
    free(data->state.first_host);

    data->state.first_host = strdup(conn->host.name);
    if(!data->state.first_host)
      return CURLE_OUT_OF_MEMORY;

    data->state.first_remote_port = conn->remote_port;
  }
  http->writebytecount = http->readbytecount = 0;

  if((conn->handler->protocol&(PROTO_FAMILY_HTTP|CURLPROTO_FTP)) &&
     data->set.upload) {
    httpreq = HTTPREQ_PUT;
  }

  /* Now set the 'request' pointer to the proper request string */
  if(data->set.str[STRING_CUSTOMREQUEST])
    request = data->set.str[STRING_CUSTOMREQUEST];
  else {
    if(data->set.opt_no_body)
      request = "HEAD";
    else {
      DEBUGASSERT((httpreq > HTTPREQ_NONE) && (httpreq < HTTPREQ_LAST));
      switch(httpreq) {
      case HTTPREQ_POST:
      case HTTPREQ_POST_FORM:
      case HTTPREQ_POST_MIME:
        request = "POST";
        break;
      case HTTPREQ_PUT:
        request = "PUT";
        break;
      case HTTPREQ_OPTIONS:
        request = "OPTIONS";
        break;
      default: /* this should never happen */
      case HTTPREQ_GET:
        request = "GET";
        break;
      case HTTPREQ_HEAD:
        request = "HEAD";
        break;
      }
    }
  }

  /* The User-Agent string might have been allocated in url.c already, because
     it might have been used in the proxy connect, but if we have got a header
     with the user-agent string specified, we erase the previously made string
     here. */
  if(Curl_checkheaders(conn, "User-Agent:")) {
    free(conn->allocptr.uagent);
    conn->allocptr.uagent = NULL;
  }

  /* setup the authentication headers */
  result = Curl_http_output_auth(conn, request, ppath, FALSE);
  if(result)
    return result;

  if((data->state.authhost.multipass || data->state.authproxy.multipass) &&
     (httpreq != HTTPREQ_GET) &&
     (httpreq != HTTPREQ_HEAD)) {
    /* Auth is required and we are not authenticated yet. Make a PUT or POST
       with content-length zero as a "probe". */
    conn->bits.authneg = TRUE;
  }
  else
    conn->bits.authneg = FALSE;

  Curl_safefree(conn->allocptr.ref);
  if(data->change.referer && !Curl_checkheaders(conn, "Referer:")) {
    conn->allocptr.ref = aprintf("Referer: %s\r\n", data->change.referer);
    if(!conn->allocptr.ref)
      return CURLE_OUT_OF_MEMORY;
  }
  else
    conn->allocptr.ref = NULL;

#if !defined(CURL_DISABLE_COOKIES)
  if(data->set.str[STRING_COOKIE] && !Curl_checkheaders(conn, "Cookie:"))
    addcookies = data->set.str[STRING_COOKIE];
#endif

  if(!Curl_checkheaders(conn, "Accept-Encoding:") &&
     data->set.str[STRING_ENCODING]) {
    Curl_safefree(conn->allocptr.accept_encoding);
    conn->allocptr.accept_encoding =
      aprintf("Accept-Encoding: %s\r\n", data->set.str[STRING_ENCODING]);
    if(!conn->allocptr.accept_encoding)
      return CURLE_OUT_OF_MEMORY;
  }
  else {
    Curl_safefree(conn->allocptr.accept_encoding);
    conn->allocptr.accept_encoding = NULL;
  }

#ifdef HAVE_LIBZ
  /* we only consider transfer-encoding magic if libz support is built-in */

  if(!Curl_checkheaders(conn, "TE:") &&
     data->set.http_transfer_encoding) {
    /* When we are to insert a TE: header in the request, we must also insert
       TE in a Connection: header, so we need to merge the custom provided
       Connection: header and prevent the original to get sent. Note that if
       the user has inserted his/hers own TE: header we don't do this magic
       but then assume that the user will handle it all! */
    char *cptr = Curl_checkheaders(conn, "Connection:");
#define TE_HEADER "TE: gzip\r\n"

    Curl_safefree(conn->allocptr.te);

    /* Create the (updated) Connection: header */
    conn->allocptr.te = cptr? aprintf("%s, TE\r\n" TE_HEADER, cptr):
      strdup("Connection: TE\r\n" TE_HEADER);

    if(!conn->allocptr.te)
      return CURLE_OUT_OF_MEMORY;
  }
#endif

  switch(httpreq) {
  case HTTPREQ_POST_MIME:
    http->sendit = &data->set.mimepost;
    break;
  case HTTPREQ_POST_FORM:
    /* Convert the form structure into a mime structure. */
    Curl_mime_cleanpart(&http->form);
    result = Curl_getformdata(data, &http->form, data->set.httppost,
                              data->state.fread_func);
    if(result)
      return result;
    http->sendit = &http->form;
    break;
  default:
    http->sendit = NULL;
  }

  if(http->sendit) {
    const char *cthdr = Curl_checkheaders(conn, "Content-Type:");

    /* Read and seek body only. */
    http->sendit->flags |= MIME_BODY_ONLY;

    /* Prepare the mime structure headers & set content type. */

    if(cthdr)
      for(cthdr += 13; *cthdr == ' '; cthdr++)
        ;
    else if(http->sendit->kind == MIMEKIND_MULTIPART)
      cthdr = "multipart/form-data";

    curl_mime_headers(http->sendit, data->set.headers, 0);
    result = Curl_mime_prepare_headers(http->sendit, cthdr,
                                       NULL, MIMESTRATEGY_FORM);
    curl_mime_headers(http->sendit, NULL, 0);
    if(!result)
      result = Curl_mime_rewind(http->sendit);
    if(result)
      return result;
    http->postsize = Curl_mime_size(http->sendit);
  }

  ptr = Curl_checkheaders(conn, "Transfer-Encoding:");
  if(ptr) {
    /* Some kind of TE is requested, check if 'chunked' is chosen */
    data->req.upload_chunky =
      Curl_compareheader(ptr, "Transfer-Encoding:", "chunked");
  }
  else {
    if((conn->handler->protocol & PROTO_FAMILY_HTTP) &&
       (((httpreq == HTTPREQ_POST_MIME || httpreq == HTTPREQ_POST_FORM) &&
       http->postsize < 0) ||
       (data->set.upload && data->state.infilesize == -1))) {
      if(conn->bits.authneg)
        /* don't enable chunked during auth neg */
        ;
      else if(use_http_1_1plus(data, conn)) {
        /* HTTP, upload, unknown file size and not HTTP 1.0 */
        data->req.upload_chunky = TRUE;
      }
      else {
        failf(data, "Chunky upload is not supported by HTTP 1.0");
        return CURLE_UPLOAD_FAILED;
      }
    }
    else {
      /* else, no chunky upload */
      data->req.upload_chunky = FALSE;
    }

    if(data->req.upload_chunky)
      te = "Transfer-Encoding: chunked\r\n";
  }

  Curl_safefree(conn->allocptr.host);

  ptr = Curl_checkheaders(conn, "Host:");
  if(ptr && (!data->state.this_is_a_follow ||
             strcasecompare(data->state.first_host, conn->host.name))) {
#if !defined(CURL_DISABLE_COOKIES)
    /* If we have a given custom Host: header, we extract the host name in
       order to possibly use it for cookie reasons later on. We only allow the
       custom Host: header if this is NOT a redirect, as setting Host: in the
       redirected request is being out on thin ice. Except if the host name
       is the same as the first one! */
    char *cookiehost = Curl_copy_header_value(ptr);
    if(!cookiehost)
      return CURLE_OUT_OF_MEMORY;
    if(!*cookiehost)
      /* ignore empty data */
      free(cookiehost);
    else {
      /* If the host begins with '[', we start searching for the port after
         the bracket has been closed */
      int startsearch = 0;
      if(*cookiehost == '[') {
        char *closingbracket;
        /* since the 'cookiehost' is an allocated memory area that will be
           freed later we cannot simply increment the pointer */
        memmove(cookiehost, cookiehost + 1, strlen(cookiehost) - 1);
        closingbracket = strchr(cookiehost, ']');
        if(closingbracket)
          *closingbracket = 0;
      }
      else {
        char *colon = strchr(cookiehost + startsearch, ':');
        if(colon)
          *colon = 0; /* The host must not include an embedded port number */
      }
      Curl_safefree(conn->allocptr.cookiehost);
      conn->allocptr.cookiehost = cookiehost;
    }
#endif

    if(strcmp("Host:", ptr)) {
      conn->allocptr.host = aprintf("%s\r\n", ptr);
      if(!conn->allocptr.host)
        return CURLE_OUT_OF_MEMORY;
    }
    else
      /* when clearing the header */
      conn->allocptr.host = NULL;
  }
  else {
    /* When building Host: headers, we must put the host name within
       [brackets] if the host name is a plain IPv6-address. RFC2732-style. */

    if(((conn->given->protocol&CURLPROTO_HTTPS) &&
        (conn->remote_port == PORT_HTTPS)) ||
       ((conn->given->protocol&CURLPROTO_HTTP) &&
        (conn->remote_port == PORT_HTTP)) )
      /* if(HTTPS on port 443) OR (HTTP on port 80) then don't include
         the port number in the host string */
      conn->allocptr.host = aprintf("Host: %s%s%s\r\n",
                                    conn->bits.ipv6_ip?"[":"",
                                    host,
                                    conn->bits.ipv6_ip?"]":"");
    else
      conn->allocptr.host = aprintf("Host: %s%s%s:%hu\r\n",
                                    conn->bits.ipv6_ip?"[":"",
                                    host,
                                    conn->bits.ipv6_ip?"]":"",
                                    conn->remote_port);

    if(!conn->allocptr.host)
      /* without Host: we can't make a nice request */
      return CURLE_OUT_OF_MEMORY;
  }

#ifndef CURL_DISABLE_PROXY
  if(conn->bits.httpproxy && !conn->bits.tunnel_proxy) {
    /* Using a proxy but does not tunnel through it */

    /* The path sent to the proxy is in fact the entire URL. But if the remote
       host is a IDN-name, we must make sure that the request we produce only
       uses the encoded host name! */
    if(conn->host.dispname != conn->host.name) {
      char *url = data->change.url;
      ptr = strstr(url, conn->host.dispname);
      if(ptr) {
        /* This is where the display name starts in the URL, now replace this
           part with the encoded name. TODO: This method of replacing the host
           name is rather crude as I believe there's a slight risk that the
           user has entered a user name or password that contain the host name
           string. */
        size_t currlen = strlen(conn->host.dispname);
        size_t newlen = strlen(conn->host.name);
        size_t urllen = strlen(url);

        char *newurl;

        newurl = malloc(urllen + newlen - currlen + 1);
        if(newurl) {
          /* copy the part before the host name */
          memcpy(newurl, url, ptr - url);
          /* append the new host name instead of the old */
          memcpy(newurl + (ptr - url), conn->host.name, newlen);
          /* append the piece after the host name */
          memcpy(newurl + newlen + (ptr - url),
                 ptr + currlen, /* copy the trailing zero byte too */
                 urllen - (ptr-url) - currlen + 1);
          if(data->change.url_alloc) {
            Curl_safefree(data->change.url);
            data->change.url_alloc = FALSE;
          }
          data->change.url = newurl;
          data->change.url_alloc = TRUE;
        }
        else
          return CURLE_OUT_OF_MEMORY;
      }
    }
    ppath = data->change.url;
    if(checkprefix("ftp://", ppath)) {
      if(data->set.proxy_transfer_mode) {
        /* when doing ftp, append ;type=<a|i> if not present */
        char *type = strstr(ppath, ";type=");
        if(type && type[6] && type[7] == 0) {
          switch(Curl_raw_toupper(type[6])) {
          case 'A':
          case 'D':
          case 'I':
            break;
          default:
            type = NULL;
          }
        }
        if(!type) {
          char *p = ftp_typecode;
          /* avoid sending invalid URLs like ftp://example.com;type=i if the
           * user specified ftp://example.com without the slash */
          if(!*data->state.path && ppath[strlen(ppath) - 1] != '/') {
            *p++ = '/';
          }
          snprintf(p, sizeof(ftp_typecode) - 1, ";type=%c",
                   data->set.prefer_ascii ? 'a' : 'i');
        }
      }
      if(conn->bits.user_passwd && !conn->bits.userpwd_in_url)
        paste_ftp_userpwd = TRUE;
    }
  }
#endif /* CURL_DISABLE_PROXY */

  http->p_accept = Curl_checkheaders(conn, "Accept:")?NULL:"Accept: */*\r\n";

  if((HTTPREQ_POST == httpreq || HTTPREQ_PUT == httpreq) &&
     data->state.resume_from) {
    /**********************************************************************
     * Resuming upload in HTTP means that we PUT or POST and that we have
     * got a resume_from value set. The resume value has already created
     * a Range: header that will be passed along. We need to "fast forward"
     * the file the given number of bytes and decrease the assume upload
     * file size before we continue this venture in the dark lands of HTTP.
     * Resuming mime/form posting at an offset > 0 has no sense and is ignored.
     *********************************************************************/

    if(data->state.resume_from < 0) {
      /*
       * This is meant to get the size of the present remote-file by itself.
       * We don't support this now. Bail out!
       */
      data->state.resume_from = 0;
    }

    if(data->state.resume_from && !data->state.this_is_a_follow) {
      /* do we still game? */

      /* Now, let's read off the proper amount of bytes from the
         input. */
      if(conn->seek_func) {
        seekerr = conn->seek_func(conn->seek_client, data->state.resume_from,
                                  SEEK_SET);
      }

      if(seekerr != CURL_SEEKFUNC_OK) {
        curl_off_t passed = 0;

        if(seekerr != CURL_SEEKFUNC_CANTSEEK) {
          failf(data, "Could not seek stream");
          return CURLE_READ_ERROR;
        }
        /* when seekerr == CURL_SEEKFUNC_CANTSEEK (can't seek to offset) */
        do {
          size_t readthisamountnow =
            (data->state.resume_from - passed > data->set.buffer_size) ?
            (size_t)data->set.buffer_size :
            curlx_sotouz(data->state.resume_from - passed);

          size_t actuallyread =
            data->state.fread_func(data->state.buffer, 1, readthisamountnow,
                                   data->state.in);

          passed += actuallyread;
          if((actuallyread == 0) || (actuallyread > readthisamountnow)) {
            /* this checks for greater-than only to make sure that the
               CURL_READFUNC_ABORT return code still aborts */
            failf(data, "Could only read %" CURL_FORMAT_CURL_OFF_T
                  " bytes from the input", passed);
            return CURLE_READ_ERROR;
          }
        } while(passed < data->state.resume_from);
      }

      /* now, decrease the size of the read */
      if(data->state.infilesize>0) {
        data->state.infilesize -= data->state.resume_from;

        if(data->state.infilesize <= 0) {
          failf(data, "File already completely uploaded");
          return CURLE_PARTIAL_FILE;
        }
      }
      /* we've passed, proceed as normal */
    }
  }
  if(data->state.use_range) {
    /*
     * A range is selected. We use different headers whether we're downloading
     * or uploading and we always let customized headers override our internal
     * ones if any such are specified.
     */
    if(((httpreq == HTTPREQ_GET) || (httpreq == HTTPREQ_HEAD)) &&
       !Curl_checkheaders(conn, "Range:")) {
      /* if a line like this was already allocated, free the previous one */
      free(conn->allocptr.rangeline);
      conn->allocptr.rangeline = aprintf("Range: bytes=%s\r\n",
                                         data->state.range);
    }
    else if((httpreq == HTTPREQ_POST || httpreq == HTTPREQ_PUT) &&
            !Curl_checkheaders(conn, "Content-Range:")) {

      /* if a line like this was already allocated, free the previous one */
      free(conn->allocptr.rangeline);

      if(data->set.set_resume_from < 0) {
        /* Upload resume was asked for, but we don't know the size of the
           remote part so we tell the server (and act accordingly) that we
           upload the whole file (again) */
        conn->allocptr.rangeline =
          aprintf("Content-Range: bytes 0-%" CURL_FORMAT_CURL_OFF_T
                  "/%" CURL_FORMAT_CURL_OFF_T "\r\n",
                  data->state.infilesize - 1, data->state.infilesize);

      }
      else if(data->state.resume_from) {
        /* This is because "resume" was selected */
        curl_off_t total_expected_size =
          data->state.resume_from + data->state.infilesize;
        conn->allocptr.rangeline =
          aprintf("Content-Range: bytes %s%" CURL_FORMAT_CURL_OFF_T
                  "/%" CURL_FORMAT_CURL_OFF_T "\r\n",
                  data->state.range, total_expected_size-1,
                  total_expected_size);
      }
      else {
        /* Range was selected and then we just pass the incoming range and
           append total size */
        conn->allocptr.rangeline =
          aprintf("Content-Range: bytes %s/%" CURL_FORMAT_CURL_OFF_T "\r\n",
                  data->state.range, data->state.infilesize);
      }
      if(!conn->allocptr.rangeline)
        return CURLE_OUT_OF_MEMORY;
    }
  }

  httpstring = get_http_string(data, conn);

  /* initialize a dynamic send-buffer */
  req_buffer = Curl_add_buffer_init();

  if(!req_buffer)
    return CURLE_OUT_OF_MEMORY;

  /* add the main request stuff */
  /* GET/HEAD/POST/PUT */
  result = Curl_add_bufferf(req_buffer, "%s ", request);
  if(result)
    return result;

  if(data->set.str[STRING_TARGET])
    ppath = data->set.str[STRING_TARGET];

  /* url */
  if(paste_ftp_userpwd)
    result = Curl_add_bufferf(req_buffer, "ftp://%s:%s@%s",
                              conn->user, conn->passwd,
                              ppath + sizeof("ftp://") - 1);
  else
    result = Curl_add_buffer(req_buffer, ppath, strlen(ppath));
  if(result)
    return result;

  result =
    Curl_add_bufferf(req_buffer,
                     "%s" /* ftp typecode (;type=x) */
                     " HTTP/%s\r\n" /* HTTP version */
                     "%s" /* host */
                     "%s" /* proxyuserpwd */
                     "%s" /* userpwd */
                     "%s" /* range */
                     "%s" /* user agent */
                     "%s" /* accept */
                     "%s" /* TE: */
                     "%s" /* accept-encoding */
                     "%s" /* referer */
                     "%s" /* Proxy-Connection */
                     "%s",/* transfer-encoding */

                     ftp_typecode,
                     httpstring,
                     (conn->allocptr.host?conn->allocptr.host:""),
                     conn->allocptr.proxyuserpwd?
                     conn->allocptr.proxyuserpwd:"",
                     conn->allocptr.userpwd?conn->allocptr.userpwd:"",
                     (data->state.use_range && conn->allocptr.rangeline)?
                     conn->allocptr.rangeline:"",
                     (data->set.str[STRING_USERAGENT] &&
                      *data->set.str[STRING_USERAGENT] &&
                      conn->allocptr.uagent)?
                     conn->allocptr.uagent:"",
                     http->p_accept?http->p_accept:"",
                     conn->allocptr.te?conn->allocptr.te:"",
                     (data->set.str[STRING_ENCODING] &&
                      *data->set.str[STRING_ENCODING] &&
                      conn->allocptr.accept_encoding)?
                     conn->allocptr.accept_encoding:"",
                     (data->change.referer && conn->allocptr.ref)?
                     conn->allocptr.ref:"" /* Referer: <data> */,
                     (conn->bits.httpproxy &&
                      !conn->bits.tunnel_proxy &&
                      !Curl_checkProxyheaders(conn, "Proxy-Connection:"))?
                     "Proxy-Connection: Keep-Alive\r\n":"",
                     te
      );

  /* clear userpwd and proxyuserpwd to avoid re-using old credentials
   * from re-used connections */
  Curl_safefree(conn->allocptr.userpwd);
  Curl_safefree(conn->allocptr.proxyuserpwd);

  if(result)
    return result;

  if(!(conn->handler->flags&PROTOPT_SSL) &&
     conn->httpversion != 20 &&
     (data->set.httpversion == CURL_HTTP_VERSION_2)) {
    /* append HTTP2 upgrade magic stuff to the HTTP request if it isn't done
       over SSL */
    result = Curl_http2_request_upgrade(req_buffer, conn);
    if(result)
      return result;
  }

#if !defined(CURL_DISABLE_COOKIES)
  if(data->cookies || addcookies) {
    struct Cookie *co = NULL; /* no cookies from start */
    int count = 0;

    if(data->cookies) {
      Curl_share_lock(data, CURL_LOCK_DATA_COOKIE, CURL_LOCK_ACCESS_SINGLE);
      co = Curl_cookie_getlist(data->cookies,
                               conn->allocptr.cookiehost?
                               conn->allocptr.cookiehost:host,
                               data->state.path,
                               (conn->handler->protocol&CURLPROTO_HTTPS)?
                               TRUE:FALSE);
      Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
    }
    if(co) {
      struct Cookie *store = co;
      /* now loop through all cookies that matched */
      while(co) {
        if(co->value) {
          if(0 == count) {
            result = Curl_add_bufferf(req_buffer, "Cookie: ");
            if(result)
              break;
          }
          result = Curl_add_bufferf(req_buffer,
                                    "%s%s=%s", count?"; ":"",
                                    co->name, co->value);
          if(result)
            break;
          count++;
        }
        co = co->next; /* next cookie please */
      }
      Curl_cookie_freelist(store);
    }
    if(addcookies && !result) {
      if(!count)
        result = Curl_add_bufferf(req_buffer, "Cookie: ");
      if(!result) {
        result = Curl_add_bufferf(req_buffer, "%s%s", count?"; ":"",
                                  addcookies);
        count++;
      }
    }
    if(count && !result)
      result = Curl_add_buffer(req_buffer, "\r\n", 2);

    if(result)
      return result;
  }
#endif

  result = Curl_add_timecondition(data, req_buffer);
  if(result)
    return result;

  result = Curl_add_custom_headers(conn, FALSE, req_buffer);
  if(result)
    return result;

  http->postdata = NULL;  /* nothing to post at this point */
  Curl_pgrsSetUploadSize(data, -1); /* upload size is unknown atm */

  /* If 'authdone' is FALSE, we must not set the write socket index to the
     Curl_transfer() call below, as we're not ready to actually upload any
     data yet. */

  switch(httpreq) {

  case HTTPREQ_PUT: /* Let's PUT the data to the server! */

    if(conn->bits.authneg)
      postsize = 0;
    else
      postsize = data->state.infilesize;

    if((postsize != -1) && !data->req.upload_chunky &&
       (conn->bits.authneg || !Curl_checkheaders(conn, "Content-Length:"))) {
      /* only add Content-Length if not uploading chunked */
      result = Curl_add_bufferf(req_buffer,
                                "Content-Length: %" CURL_FORMAT_CURL_OFF_T
                                "\r\n", postsize);
      if(result)
        return result;
    }

    if(postsize != 0) {
      result = expect100(data, conn, req_buffer);
      if(result)
        return result;
    }

    result = Curl_add_buffer(req_buffer, "\r\n", 2); /* end of headers */
    if(result)
      return result;

    /* set the upload size to the progress meter */
    Curl_pgrsSetUploadSize(data, postsize);

    /* this sends the buffer and frees all the buffer resources */
    result = Curl_add_buffer_send(req_buffer, conn,
                                  &data->info.request_size, 0, FIRSTSOCKET);
    if(result)
      failf(data, "Failed sending PUT request");
    else
      /* prepare for transfer */
      Curl_setup_transfer(conn, FIRSTSOCKET, -1, TRUE,
                          &http->readbytecount, postsize?FIRSTSOCKET:-1,
                          postsize?&http->writebytecount:NULL);
    if(result)
      return result;
    break;

  case HTTPREQ_POST_FORM:
  case HTTPREQ_POST_MIME:
    /* This is form posting using mime data. */
    if(conn->bits.authneg) {
      /* nothing to post! */
      result = Curl_add_bufferf(req_buffer, "Content-Length: 0\r\n\r\n");
      if(result)
        return result;

      result = Curl_add_buffer_send(req_buffer, conn,
                                    &data->info.request_size, 0, FIRSTSOCKET);
      if(result)
        failf(data, "Failed sending POST request");
      else
        /* setup variables for the upcoming transfer */
        Curl_setup_transfer(conn, FIRSTSOCKET, -1, TRUE, &http->readbytecount,
                            -1, NULL);
      break;
    }

    postsize = http->postsize;

    /* We only set Content-Length and allow a custom Content-Length if
       we don't upload data chunked, as RFC2616 forbids us to set both
       kinds of headers (Transfer-Encoding: chunked and Content-Length) */
    if(postsize != -1 && !data->req.upload_chunky &&
       (conn->bits.authneg || !Curl_checkheaders(conn, "Content-Length:"))) {
      /* we allow replacing this header if not during auth negotiation,
         although it isn't very wise to actually set your own */
      result = Curl_add_bufferf(req_buffer,
                                "Content-Length: %" CURL_FORMAT_CURL_OFF_T
                                "\r\n", postsize);
      if(result)
        return result;
    }

    /* Output mime-generated headers. */
    {
      struct curl_slist *hdr;

      for(hdr = http->sendit->curlheaders; hdr; hdr = hdr->next) {
        result = Curl_add_bufferf(req_buffer, "%s\r\n", hdr->data);
        if(result)
          return result;
      }
    }

    /* For really small posts we don't use Expect: headers at all, and for
       the somewhat bigger ones we allow the app to disable it. Just make
       sure that the expect100header is always set to the preferred value
       here. */
    ptr = Curl_checkheaders(conn, "Expect:");
    if(ptr) {
      data->state.expect100header =
        Curl_compareheader(ptr, "Expect:", "100-continue");
    }
    else if(postsize > EXPECT_100_THRESHOLD || postsize < 0) {
      result = expect100(data, conn, req_buffer);
      if(result)
        return result;
    }
    else
      data->state.expect100header = FALSE;

    /* make the request end in a true CRLF */
    result = Curl_add_buffer(req_buffer, "\r\n", 2);
    if(result)
      return result;

    /* set the upload size to the progress meter */
    Curl_pgrsSetUploadSize(data, postsize);

    /* Read from mime structure. */
    data->state.fread_func = (curl_read_callback) Curl_mime_read;
    data->state.in = (void *) http->sendit;
    http->sending = HTTPSEND_BODY;

    /* this sends the buffer and frees all the buffer resources */
    result = Curl_add_buffer_send(req_buffer, conn,
                                  &data->info.request_size, 0, FIRSTSOCKET);
    if(result)
      failf(data, "Failed sending POST request");
    else
      /* prepare for transfer */
      Curl_setup_transfer(conn, FIRSTSOCKET, -1, TRUE,
                          &http->readbytecount, postsize?FIRSTSOCKET:-1,
                          postsize?&http->writebytecount:NULL);
    if(result)
      return result;

    break;

  case HTTPREQ_POST:
    /* this is the simple POST, using x-www-form-urlencoded style */

    if(conn->bits.authneg)
      postsize = 0;
    else
      /* the size of the post body */
      postsize = data->state.infilesize;

    /* We only set Content-Length and allow a custom Content-Length if
       we don't upload data chunked, as RFC2616 forbids us to set both
       kinds of headers (Transfer-Encoding: chunked and Content-Length) */
    if((postsize != -1) && !data->req.upload_chunky &&
       (conn->bits.authneg || !Curl_checkheaders(conn, "Content-Length:"))) {
      /* we allow replacing this header if not during auth negotiation,
         although it isn't very wise to actually set your own */
      result = Curl_add_bufferf(req_buffer,
                                "Content-Length: %" CURL_FORMAT_CURL_OFF_T
                                "\r\n", postsize);
      if(result)
        return result;
    }

    if(!Curl_checkheaders(conn, "Content-Type:")) {
      result = Curl_add_bufferf(req_buffer,
                                "Content-Type: application/"
                                "x-www-form-urlencoded\r\n");
      if(result)
        return result;
    }

    /* For really small posts we don't use Expect: headers at all, and for
       the somewhat bigger ones we allow the app to disable it. Just make
       sure that the expect100header is always set to the preferred value
       here. */
    ptr = Curl_checkheaders(conn, "Expect:");
    if(ptr) {
      data->state.expect100header =
        Curl_compareheader(ptr, "Expect:", "100-continue");
    }
    else if(postsize > EXPECT_100_THRESHOLD || postsize < 0) {
      result = expect100(data, conn, req_buffer);
      if(result)
        return result;
    }
    else
      data->state.expect100header = FALSE;

    if(data->set.postfields) {

      /* In HTTP2, we send request body in DATA frame regardless of
         its size. */
      if(conn->httpversion != 20 &&
         !data->state.expect100header &&
         (postsize < MAX_INITIAL_POST_SIZE)) {
        /* if we don't use expect: 100  AND
           postsize is less than MAX_INITIAL_POST_SIZE

           then append the post data to the HTTP request header. This limit
           is no magic limit but only set to prevent really huge POSTs to
           get the data duplicated with malloc() and family. */

        result = Curl_add_buffer(req_buffer, "\r\n", 2); /* end of headers! */
        if(result)
          return result;

        if(!data->req.upload_chunky) {
          /* We're not sending it 'chunked', append it to the request
             already now to reduce the number if send() calls */
          result = Curl_add_buffer(req_buffer, data->set.postfields,
                                   (size_t)postsize);
          included_body = postsize;
        }
        else {
          if(postsize) {
            /* Append the POST data chunky-style */
            result = Curl_add_bufferf(req_buffer, "%x\r\n", (int)postsize);
            if(!result) {
              result = Curl_add_buffer(req_buffer, data->set.postfields,
                                       (size_t)postsize);
              if(!result)
                result = Curl_add_buffer(req_buffer, "\r\n", 2);
              included_body = postsize + 2;
            }
          }
          if(!result)
            result = Curl_add_buffer(req_buffer, "\x30\x0d\x0a\x0d\x0a", 5);
          /* 0  CR  LF  CR  LF */
          included_body += 5;
        }
        if(result)
          return result;
        /* Make sure the progress information is accurate */
        Curl_pgrsSetUploadSize(data, postsize);
      }
      else {
        /* A huge POST coming up, do data separate from the request */
        http->postsize = postsize;
        http->postdata = data->set.postfields;

        http->sending = HTTPSEND_BODY;

        data->state.fread_func = (curl_read_callback)readmoredata;
        data->state.in = (void *)conn;

        /* set the upload size to the progress meter */
        Curl_pgrsSetUploadSize(data, http->postsize);

        result = Curl_add_buffer(req_buffer, "\r\n", 2); /* end of headers! */
        if(result)
          return result;
      }
    }
    else {
      result = Curl_add_buffer(req_buffer, "\r\n", 2); /* end of headers! */
      if(result)
        return result;

      if(data->req.upload_chunky && conn->bits.authneg) {
        /* Chunky upload is selected and we're negotiating auth still, send
           end-of-data only */
        result = Curl_add_buffer(req_buffer,
                                 "\x30\x0d\x0a\x0d\x0a", 5);
        /* 0  CR  LF  CR  LF */
        if(result)
          return result;
      }

      else if(data->state.infilesize) {
        /* set the upload size to the progress meter */
        Curl_pgrsSetUploadSize(data, postsize?postsize:-1);

        /* set the pointer to mark that we will send the post body using the
           read callback, but only if we're not in authenticate
           negotiation  */
        if(!conn->bits.authneg) {
          http->postdata = (char *)&http->postdata;
          http->postsize = postsize;
        }
      }
    }
    /* issue the request */
    result = Curl_add_buffer_send(req_buffer, conn, &data->info.request_size,
                                  (size_t)included_body, FIRSTSOCKET);

    if(result)
      failf(data, "Failed sending HTTP POST request");
    else
      Curl_setup_transfer(conn, FIRSTSOCKET, -1, TRUE,
                          &http->readbytecount, http->postdata?FIRSTSOCKET:-1,
                          http->postdata?&http->writebytecount:NULL);
    break;

  default:
    result = Curl_add_buffer(req_buffer, "\r\n", 2);
    if(result)
      return result;

    /* issue the request */
    result = Curl_add_buffer_send(req_buffer, conn,
                                  &data->info.request_size, 0, FIRSTSOCKET);

    if(result)
      failf(data, "Failed sending HTTP request");
    else
      /* HTTP GET/HEAD download: */
      Curl_setup_transfer(conn, FIRSTSOCKET, -1, TRUE, &http->readbytecount,
                          http->postdata?FIRSTSOCKET:-1,
                          http->postdata?&http->writebytecount:NULL);
  }
  if(result)
    return result;

  if(http->writebytecount) {
    /* if a request-body has been sent off, we make sure this progress is noted
       properly */
    Curl_pgrsSetUploadCounter(data, http->writebytecount);
    if(Curl_pgrsUpdate(conn))
      result = CURLE_ABORTED_BY_CALLBACK;

    if(http->writebytecount >= postsize) {
      /* already sent the entire request body, mark the "upload" as
         complete */
      infof(data, "upload completely sent off: %" CURL_FORMAT_CURL_OFF_T
            " out of %" CURL_FORMAT_CURL_OFF_T " bytes\n",
            http->writebytecount, postsize);
      data->req.upload_done = TRUE;
      data->req.keepon &= ~KEEP_SEND; /* we're done writing */
      data->req.exp100 = EXP100_SEND_DATA; /* already sent */
      Curl_expire_done(data, EXPIRE_100_TIMEOUT);
    }
  }

  if((conn->httpversion == 20) && data->req.upload_chunky)
    /* upload_chunky was set above to set up the request in a chunky fashion,
       but is disabled here again to avoid that the chunked encoded version is
       actually used when sending the request body over h2 */
    data->req.upload_chunky = FALSE;
  return result;
}

/*
 * checkhttpprefix()
 *
 * Returns TRUE if member of the list matches prefix of string
 */
static bool
checkhttpprefix(struct Curl_easy *data,
                const char *s)
{
  struct curl_slist *head = data->set.http200aliases;
  bool rc = FALSE;
#ifdef CURL_DOES_CONVERSIONS
  /* convert from the network encoding using a scratch area */
  char *scratch = strdup(s);
  if(NULL == scratch) {
    failf(data, "Failed to allocate memory for conversion!");
    return FALSE; /* can't return CURLE_OUT_OF_MEMORY so return FALSE */
  }
  if(CURLE_OK != Curl_convert_from_network(data, scratch, strlen(s) + 1)) {
    /* Curl_convert_from_network calls failf if unsuccessful */
    free(scratch);
    return FALSE; /* can't return CURLE_foobar so return FALSE */
  }
  s = scratch;
#endif /* CURL_DOES_CONVERSIONS */

  while(head) {
    if(checkprefix(head->data, s)) {
      rc = TRUE;
      break;
    }
    head = head->next;
  }

  if(!rc && (checkprefix("HTTP/", s)))
    rc = TRUE;

#ifdef CURL_DOES_CONVERSIONS
  free(scratch);
#endif /* CURL_DOES_CONVERSIONS */
  return rc;
}

#ifndef CURL_DISABLE_RTSP
static bool
checkrtspprefix(struct Curl_easy *data,
                const char *s)
{
  bool result = FALSE;

#ifdef CURL_DOES_CONVERSIONS
  /* convert from the network encoding using a scratch area */
  char *scratch = strdup(s);
  if(NULL == scratch) {
    failf(data, "Failed to allocate memory for conversion!");
    return FALSE; /* can't return CURLE_OUT_OF_MEMORY so return FALSE */
  }
  if(CURLE_OK != Curl_convert_from_network(data, scratch, strlen(s) + 1)) {
    /* Curl_convert_from_network calls failf if unsuccessful */
    result = FALSE; /* can't return CURLE_foobar so return FALSE */
  }
  else
    result = checkprefix("RTSP/", scratch)? TRUE: FALSE;
  free(scratch);
#else
  (void)data; /* unused */
  result = checkprefix("RTSP/", s)? TRUE: FALSE;
#endif /* CURL_DOES_CONVERSIONS */

  return result;
}
#endif /* CURL_DISABLE_RTSP */

static bool
checkprotoprefix(struct Curl_easy *data, struct connectdata *conn,
                 const char *s)
{
#ifndef CURL_DISABLE_RTSP
  if(conn->handler->protocol & CURLPROTO_RTSP)
    return checkrtspprefix(data, s);
#else
  (void)conn;
#endif /* CURL_DISABLE_RTSP */

  return checkhttpprefix(data, s);
}

/*
 * header_append() copies a chunk of data to the end of the already received
 * header. We make sure that the full string fit in the allocated header
 * buffer, or else we enlarge it.
 */
static CURLcode header_append(struct Curl_easy *data,
                              struct SingleRequest *k,
                              size_t length)
{
  if(k->hbuflen + length >= data->state.headersize) {
    /* We enlarge the header buffer as it is too small */
    char *newbuff;
    size_t hbufp_index;
    size_t newsize;

    if(k->hbuflen + length > CURL_MAX_HTTP_HEADER) {
      /* The reason to have a max limit for this is to avoid the risk of a bad
         server feeding libcurl with a never-ending header that will cause
         reallocs infinitely */
      failf(data, "Avoided giant realloc for header (max is %d)!",
            CURL_MAX_HTTP_HEADER);
      return CURLE_OUT_OF_MEMORY;
    }

    newsize = CURLMAX((k->hbuflen + length) * 3 / 2, data->state.headersize*2);
    hbufp_index = k->hbufp - data->state.headerbuff;
    newbuff = realloc(data->state.headerbuff, newsize);
    if(!newbuff) {
      failf(data, "Failed to alloc memory for big header!");
      return CURLE_OUT_OF_MEMORY;
    }
    data->state.headersize = newsize;
    data->state.headerbuff = newbuff;
    k->hbufp = data->state.headerbuff + hbufp_index;
  }
  memcpy(k->hbufp, k->str_start, length);
  k->hbufp += length;
  k->hbuflen += length;
  *k->hbufp = 0;

  return CURLE_OK;
}

static void print_http_error(struct Curl_easy *data)
{
  struct SingleRequest *k = &data->req;
  char *beg = k->p;

  /* make sure that data->req.p points to the HTTP status line */
  if(!strncmp(beg, "HTTP", 4)) {

    /* skip to HTTP status code */
    beg = strchr(beg, ' ');
    if(beg && *++beg) {

      /* find trailing CR */
      char end_char = '\r';
      char *end = strchr(beg, end_char);
      if(!end) {
        /* try to find LF (workaround for non-compliant HTTP servers) */
        end_char = '\n';
        end = strchr(beg, end_char);
      }

      if(end) {
        /* temporarily replace CR or LF by NUL and print the error message */
        *end = '\0';
        failf(data, "The requested URL returned error: %s", beg);

        /* restore the previously replaced CR or LF */
        *end = end_char;
        return;
      }
    }
  }

  /* fall-back to printing the HTTP status code only */
  failf(data, "The requested URL returned error: %d", k->httpcode);
}

/*
 * Read any HTTP header lines from the server and pass them to the client app.
 */
CURLcode Curl_http_readwrite_headers(struct Curl_easy *data,
                                       struct connectdata *conn,
                                       ssize_t *nread,
                                       bool *stop_reading)
{
  CURLcode result;
  struct SingleRequest *k = &data->req;

  /* header line within buffer loop */
  do {
    size_t rest_length;
    size_t full_length;
    int writetype;

    /* str_start is start of line within buf */
    k->str_start = k->str;

    /* data is in network encoding so use 0x0a instead of '\n' */
    k->end_ptr = memchr(k->str_start, 0x0a, *nread);

    if(!k->end_ptr) {
      /* Not a complete header line within buffer, append the data to
         the end of the headerbuff. */
      result = header_append(data, k, *nread);
      if(result)
        return result;

      if(!k->headerline && (k->hbuflen>5)) {
        /* make a first check that this looks like a protocol header */
        if(!checkprotoprefix(data, conn, data->state.headerbuff)) {
          /* this is not the beginning of a protocol first header line */
          k->header = FALSE;
          k->badheader = HEADER_ALLBAD;
          break;
        }
      }

      break; /* read more and try again */
    }

    /* decrease the size of the remaining (supposed) header line */
    rest_length = (k->end_ptr - k->str) + 1;
    *nread -= (ssize_t)rest_length;

    k->str = k->end_ptr + 1; /* move past new line */

    full_length = k->str - k->str_start;

    result = header_append(data, k, full_length);
    if(result)
      return result;

    k->end_ptr = k->hbufp;
    k->p = data->state.headerbuff;

    /****
     * We now have a FULL header line that p points to
     *****/

    if(!k->headerline) {
      /* the first read header */
      if((k->hbuflen>5) &&
         !checkprotoprefix(data, conn, data->state.headerbuff)) {
        /* this is not the beginning of a protocol first header line */
        k->header = FALSE;
        if(*nread)
          /* since there's more, this is a partial bad header */
          k->badheader = HEADER_PARTHEADER;
        else {
          /* this was all we read so it's all a bad header */
          k->badheader = HEADER_ALLBAD;
          *nread = (ssize_t)rest_length;
        }
        break;
      }
    }

    /* headers are in network encoding so
       use 0x0a and 0x0d instead of '\n' and '\r' */
    if((0x0a == *k->p) || (0x0d == *k->p)) {
      size_t headerlen;
      /* Zero-length header line means end of headers! */

#ifdef CURL_DOES_CONVERSIONS
      if(0x0d == *k->p) {
        *k->p = '\r'; /* replace with CR in host encoding */
        k->p++;       /* pass the CR byte */
      }
      if(0x0a == *k->p) {
        *k->p = '\n'; /* replace with LF in host encoding */
        k->p++;       /* pass the LF byte */
      }
#else
      if('\r' == *k->p)
        k->p++; /* pass the \r byte */
      if('\n' == *k->p)
        k->p++; /* pass the \n byte */
#endif /* CURL_DOES_CONVERSIONS */

      if(100 <= k->httpcode && 199 >= k->httpcode) {
        /* "A user agent MAY ignore unexpected 1xx status responses." */
        switch(k->httpcode) {
        case 100:
          /*
           * We have made a HTTP PUT or POST and this is 1.1-lingo
           * that tells us that the server is OK with this and ready
           * to receive the data.
           * However, we'll get more headers now so we must get
           * back into the header-parsing state!
           */
          k->header = TRUE;
          k->headerline = 0; /* restart the header line counter */

          /* if we did wait for this do enable write now! */
          if(k->exp100 > EXP100_SEND_DATA) {
            k->exp100 = EXP100_SEND_DATA;
            k->keepon |= KEEP_SEND;
            Curl_expire_done(data, EXPIRE_100_TIMEOUT);
          }
          break;
        case 101:
          /* Switching Protocols */
          if(k->upgr101 == UPGR101_REQUESTED) {
            /* Switching to HTTP/2 */
            infof(data, "Received 101\n");
            k->upgr101 = UPGR101_RECEIVED;

            /* we'll get more headers (HTTP/2 response) */
            k->header = TRUE;
            k->headerline = 0; /* restart the header line counter */

            /* switch to http2 now. The bytes after response headers
               are also processed here, otherwise they are lost. */
            result = Curl_http2_switched(conn, k->str, *nread);
            if(result)
              return result;
            *nread = 0;
          }
          else {
            /* Switching to another protocol (e.g. WebSocket) */
            k->header = FALSE; /* no more header to parse! */
          }
          break;
        default:
          /* the status code 1xx indicates a provisional response, so
             we'll get another set of headers */
          k->header = TRUE;
          k->headerline = 0; /* restart the header line counter */
          break;
        }
      }
      else {
        k->header = FALSE; /* no more header to parse! */

        if((k->size == -1) && !k->chunk && !conn->bits.close &&
           (conn->httpversion == 11) &&
           !(conn->handler->protocol & CURLPROTO_RTSP) &&
           data->set.httpreq != HTTPREQ_HEAD) {
          /* On HTTP 1.1, when connection is not to get closed, but no
             Content-Length nor Content-Encoding chunked have been
             received, according to RFC2616 section 4.4 point 5, we
             assume that the server will close the connection to
             signal the end of the document. */
          infof(data, "no chunk, no close, no size. Assume close to "
                "signal end\n");
          streamclose(conn, "HTTP: No end-of-message indicator");
        }
      }

      /* At this point we have some idea about the fate of the connection.
         If we are closing the connection it may result auth failure. */
#if defined(USE_NTLM)
      if(conn->bits.close &&
         (((data->req.httpcode == 401) &&
           (conn->ntlm.state == NTLMSTATE_TYPE2)) ||
          ((data->req.httpcode == 407) &&
           (conn->proxyntlm.state == NTLMSTATE_TYPE2)))) {
        infof(data, "Connection closure while negotiating auth (HTTP 1.0?)\n");
        data->state.authproblem = TRUE;
      }
#endif

      /*
       * When all the headers have been parsed, see if we should give
       * up and return an error.
       */
      if(http_should_fail(conn)) {
        failf(data, "The requested URL returned error: %d",
              k->httpcode);
        return CURLE_HTTP_RETURNED_ERROR;
      }

      /* now, only output this if the header AND body are requested:
       */
      writetype = CLIENTWRITE_HEADER;
      if(data->set.include_header)
        writetype |= CLIENTWRITE_BODY;

      headerlen = k->p - data->state.headerbuff;

      result = Curl_client_write(conn, writetype,
                                 data->state.headerbuff,
                                 headerlen);
      if(result)
        return result;

      data->info.header_size += (long)headerlen;
      data->req.headerbytecount += (long)headerlen;

      data->req.deductheadercount =
        (100 <= k->httpcode && 199 >= k->httpcode)?data->req.headerbytecount:0;

      /* Curl_http_auth_act() checks what authentication methods
       * that are available and decides which one (if any) to
       * use. It will set 'newurl' if an auth method was picked. */
      result = Curl_http_auth_act(conn);

      if(result)
        return result;

      if(k->httpcode >= 300) {
        if((!conn->bits.authneg) && !conn->bits.close &&
           !conn->bits.rewindaftersend) {
          /*
           * General treatment of errors when about to send data. Including :
           * "417 Expectation Failed", while waiting for 100-continue.
           *
           * The check for close above is done simply because of something
           * else has already deemed the connection to get closed then
           * something else should've considered the big picture and we
           * avoid this check.
           *
           * rewindaftersend indicates that something has told libcurl to
           * continue sending even if it gets discarded
           */

          switch(data->set.httpreq) {
          case HTTPREQ_PUT:
          case HTTPREQ_POST:
          case HTTPREQ_POST_FORM:
          case HTTPREQ_POST_MIME:
            /* We got an error response. If this happened before the whole
             * request body has been sent we stop sending and mark the
             * connection for closure after we've read the entire response.
             */
            Curl_expire_done(data, EXPIRE_100_TIMEOUT);
            if(!k->upload_done) {
              if(data->set.http_keep_sending_on_error) {
                infof(data, "HTTP error before end of send, keep sending\n");
                if(k->exp100 > EXP100_SEND_DATA) {
                  k->exp100 = EXP100_SEND_DATA;
                  k->keepon |= KEEP_SEND;
                }
              }
              else {
                infof(data, "HTTP error before end of send, stop sending\n");
                streamclose(conn, "Stop sending data before everything sent");
                k->upload_done = TRUE;
                k->keepon &= ~KEEP_SEND; /* don't send */
                if(data->state.expect100header)
                  k->exp100 = EXP100_FAILED;
              }
            }
            break;

          default: /* default label present to avoid compiler warnings */
            break;
          }
        }

        if(conn->bits.rewindaftersend) {
          /* We rewind after a complete send, so thus we continue
             sending now */
          infof(data, "Keep sending data to get tossed away!\n");
          k->keepon |= KEEP_SEND;
        }
      }

      if(!k->header) {
        /*
         * really end-of-headers.
         *
         * If we requested a "no body", this is a good time to get
         * out and return home.
         */
        if(data->set.opt_no_body)
          *stop_reading = TRUE;
#ifndef CURL_DISABLE_RTSP
        else if((conn->handler->protocol & CURLPROTO_RTSP) &&
                (data->set.rtspreq == RTSPREQ_DESCRIBE) &&
                (k->size <= -1))
          /* Respect section 4.4 of rfc2326: If the Content-Length header is
             absent, a length 0 must be assumed.  It will prevent libcurl from
             hanging on DESCRIBE request that got refused for whatever
             reason */
          *stop_reading = TRUE;
#endif
        else {
          /* If we know the expected size of this document, we set the
             maximum download size to the size of the expected
             document or else, we won't know when to stop reading!

             Note that we set the download maximum even if we read a
             "Connection: close" header, to make sure that
             "Content-Length: 0" still prevents us from attempting to
             read the (missing) response-body.
          */
          /* According to RFC2616 section 4.4, we MUST ignore
             Content-Length: headers if we are now receiving data
             using chunked Transfer-Encoding.
          */
          if(k->chunk)
            k->maxdownload = k->size = -1;
        }
        if(-1 != k->size) {
          /* We do this operation even if no_body is true, since this
             data might be retrieved later with curl_easy_getinfo()
             and its CURLINFO_CONTENT_LENGTH_DOWNLOAD option. */

          Curl_pgrsSetDownloadSize(data, k->size);
          k->maxdownload = k->size;
        }

        /* If max download size is *zero* (nothing) we already have
           nothing and can safely return ok now!  But for HTTP/2, we'd
           like to call http2_handle_stream_close to properly close a
           stream.  In order to do this, we keep reading until we
           close the stream. */
        if(0 == k->maxdownload
#if defined(USE_NGHTTP2)
           && !((conn->handler->protocol & PROTO_FAMILY_HTTP) &&
                conn->httpversion == 20)
#endif
           )
          *stop_reading = TRUE;

        if(*stop_reading) {
          /* we make sure that this socket isn't read more now */
          k->keepon &= ~KEEP_RECV;
        }

        if(data->set.verbose)
          Curl_debug(data, CURLINFO_HEADER_IN,
                     k->str_start, headerlen, conn);
        break;          /* exit header line loop */
      }

      /* We continue reading headers, so reset the line-based
         header parsing variables hbufp && hbuflen */
      k->hbufp = data->state.headerbuff;
      k->hbuflen = 0;
      continue;
    }

    /*
     * Checks for special headers coming up.
     */

    if(!k->headerline++) {
      /* This is the first header, it MUST be the error code line
         or else we consider this to be the body right away! */
      int httpversion_major;
      int rtspversion_major;
      int nc = 0;
#ifdef CURL_DOES_CONVERSIONS
#define HEADER1 scratch
#define SCRATCHSIZE 21
      CURLcode res;
      char scratch[SCRATCHSIZE + 1]; /* "HTTP/major.minor 123" */
      /* We can't really convert this yet because we
         don't know if it's the 1st header line or the body.
         So we do a partial conversion into a scratch area,
         leaving the data at k->p as-is.
      */
      strncpy(&scratch[0], k->p, SCRATCHSIZE);
      scratch[SCRATCHSIZE] = 0; /* null terminate */
      res = Curl_convert_from_network(data,
                                      &scratch[0],
                                      SCRATCHSIZE);
      if(res)
        /* Curl_convert_from_network calls failf if unsuccessful */
        return res;
#else
#define HEADER1 k->p /* no conversion needed, just use k->p */
#endif /* CURL_DOES_CONVERSIONS */

      if(conn->handler->protocol & PROTO_FAMILY_HTTP) {
        /*
         * https://tools.ietf.org/html/rfc7230#section-3.1.2
         *
         * The response code is always a three-digit number in HTTP as the spec
         * says. We try to allow any number here, but we cannot make
         * guarantees on future behaviors since it isn't within the protocol.
         */
        char separator;
        nc = sscanf(HEADER1,
                    " HTTP/%1d.%1d%c%3d",
                    &httpversion_major,
                    &conn->httpversion,
                    &separator,
                    &k->httpcode);

        if(nc == 1 && httpversion_major == 2 &&
           1 == sscanf(HEADER1, " HTTP/2 %d", &k->httpcode)) {
          conn->httpversion = 0;
          nc = 4;
          separator = ' ';
        }

        if((nc == 4) && (' ' == separator)) {
          conn->httpversion += 10 * httpversion_major;

          if(k->upgr101 == UPGR101_RECEIVED) {
            /* supposedly upgraded to http2 now */
            if(conn->httpversion != 20)
              infof(data, "Lying server, not serving HTTP/2\n");
          }
        }
        else if(!nc) {
          /* this is the real world, not a Nirvana
             NCSA 1.5.x returns this crap when asked for HTTP/1.1
          */
          nc = sscanf(HEADER1, " HTTP %3d", &k->httpcode);
          conn->httpversion = 10;

          /* If user has set option HTTP200ALIASES,
             compare header line against list of aliases
          */
          if(!nc) {
            if(checkhttpprefix(data, k->p)) {
              nc = 1;
              k->httpcode = 200;
              conn->httpversion = 10;
            }
          }
        }
        else {
          failf(data, "Unsupported HTTP version in response\n");
          return CURLE_UNSUPPORTED_PROTOCOL;
        }
      }
      else if(conn->handler->protocol & CURLPROTO_RTSP) {
        nc = sscanf(HEADER1,
                    " RTSP/%d.%d %3d",
                    &rtspversion_major,
                    &conn->rtspversion,
                    &k->httpcode);
        if(nc == 3) {
          conn->rtspversion += 10 * rtspversion_major;
          conn->httpversion = 11; /* For us, RTSP acts like HTTP 1.1 */
        }
        else {
          /* TODO: do we care about the other cases here? */
          nc = 0;
        }
      }

      if(nc) {
        data->info.httpcode = k->httpcode;

        data->info.httpversion = conn->httpversion;
        if(!data->state.httpversion ||
           data->state.httpversion > conn->httpversion)
          /* store the lowest server version we encounter */
          data->state.httpversion = conn->httpversion;

        /*
         * This code executes as part of processing the header.  As a
         * result, it's not totally clear how to interpret the
         * response code yet as that depends on what other headers may
         * be present.  401 and 407 may be errors, but may be OK
         * depending on how authentication is working.  Other codes
         * are definitely errors, so give up here.
         */
        if(data->set.http_fail_on_error && (k->httpcode >= 400) &&
           ((k->httpcode != 401) || !conn->bits.user_passwd) &&
           ((k->httpcode != 407) || !conn->bits.proxy_user_passwd) ) {

          if(data->state.resume_from &&
             (data->set.httpreq == HTTPREQ_GET) &&
             (k->httpcode == 416)) {
            /* "Requested Range Not Satisfiable", just proceed and
               pretend this is no error */
          }
          else {
            /* serious error, go home! */
            print_http_error(data);
            return CURLE_HTTP_RETURNED_ERROR;
          }
        }

        if(conn->httpversion == 10) {
          /* Default action for HTTP/1.0 must be to close, unless
             we get one of those fancy headers that tell us the
             server keeps it open for us! */
          infof(data, "HTTP 1.0, assume close after body\n");
          connclose(conn, "HTTP/1.0 close after body");
        }
        else if(conn->httpversion == 20 ||
                (k->upgr101 == UPGR101_REQUESTED && k->httpcode == 101)) {
          DEBUGF(infof(data, "HTTP/2 found, allow multiplexing\n"));

          /* HTTP/2 cannot blacklist multiplexing since it is a core
             functionality of the protocol */
          conn->bundle->multiuse = BUNDLE_MULTIPLEX;
        }
        else if(conn->httpversion >= 11 &&
                !conn->bits.close) {
          /* If HTTP version is >= 1.1 and connection is persistent
             server supports pipelining. */
          DEBUGF(infof(data,
                       "HTTP 1.1 or later with persistent connection, "
                       "pipelining supported\n"));
          /* Activate pipelining if needed */
          if(conn->bundle) {
            if(!Curl_pipeline_site_blacklisted(data, conn))
              conn->bundle->multiuse = BUNDLE_PIPELINING;
          }
        }

        switch(k->httpcode) {
        case 204:
          /* (quote from RFC2616, section 10.2.5): The server has
           * fulfilled the request but does not need to return an
           * entity-body ... The 204 response MUST NOT include a
           * message-body, and thus is always terminated by the first
           * empty line after the header fields. */
          /* FALLTHROUGH */
        case 304:
          /* (quote from RFC2616, section 10.3.5): The 304 response
           * MUST NOT contain a message-body, and thus is always
           * terminated by the first empty line after the header
           * fields.  */
          if(data->set.timecondition)
            data->info.timecond = TRUE;
          k->size = 0;
          k->maxdownload = 0;
          k->ignorecl = TRUE; /* ignore Content-Length headers */
          break;
        default:
          /* nothing */
          break;
        }
      }
      else {
        k->header = FALSE;   /* this is not a header line */
        break;
      }
    }

    result = Curl_convert_from_network(data, k->p, strlen(k->p));
    /* Curl_convert_from_network calls failf if unsuccessful */
    if(result)
      return result;

    /* Check for Content-Length: header lines to get size */
    if(!k->ignorecl && !data->set.ignorecl &&
       checkprefix("Content-Length:", k->p)) {
      curl_off_t contentlength;
      if(!curlx_strtoofft(k->p + 15, NULL, 10, &contentlength)) {
        if(data->set.max_filesize &&
           contentlength > data->set.max_filesize) {
          failf(data, "Maximum file size exceeded");
          return CURLE_FILESIZE_EXCEEDED;
        }
        if(contentlength >= 0) {
          k->size = contentlength;
          k->maxdownload = k->size;
          /* we set the progress download size already at this point
             just to make it easier for apps/callbacks to extract this
             info as soon as possible */
          Curl_pgrsSetDownloadSize(data, k->size);
        }
        else {
          /* Negative Content-Length is really odd, and we know it
             happens for example when older Apache servers send large
             files */
          streamclose(conn, "negative content-length");
          infof(data, "Negative content-length: %" CURL_FORMAT_CURL_OFF_T
                ", closing after transfer\n", contentlength);
        }
      }
      else
        infof(data, "Illegal Content-Length: header\n");
    }
    /* check for Content-Type: header lines to get the MIME-type */
    else if(checkprefix("Content-Type:", k->p)) {
      char *contenttype = Curl_copy_header_value(k->p);
      if(!contenttype)
        return CURLE_OUT_OF_MEMORY;
      if(!*contenttype)
        /* ignore empty data */
        free(contenttype);
      else {
        Curl_safefree(data->info.contenttype);
        data->info.contenttype = contenttype;
      }
    }
    else if(checkprefix("Server:", k->p)) {
      if(conn->httpversion < 20) {
        /* only do this for non-h2 servers */
        char *server_name = Curl_copy_header_value(k->p);

        /* Turn off pipelining if the server version is blacklisted  */
        if(conn->bundle && (conn->bundle->multiuse == BUNDLE_PIPELINING)) {
          if(Curl_pipeline_server_blacklisted(data, server_name))
            conn->bundle->multiuse = BUNDLE_NO_MULTIUSE;
        }
        free(server_name);
      }
    }
    else if((conn->httpversion == 10) &&
            conn->bits.httpproxy &&
            Curl_compareheader(k->p,
                               "Proxy-Connection:", "keep-alive")) {
      /*
       * When a HTTP/1.0 reply comes when using a proxy, the
       * 'Proxy-Connection: keep-alive' line tells us the
       * connection will be kept alive for our pleasure.
       * Default action for 1.0 is to close.
       */
      connkeep(conn, "Proxy-Connection keep-alive"); /* don't close */
      infof(data, "HTTP/1.0 proxy connection set to keep alive!\n");
    }
    else if((conn->httpversion == 11) &&
            conn->bits.httpproxy &&
            Curl_compareheader(k->p,
                               "Proxy-Connection:", "close")) {
      /*
       * We get a HTTP/1.1 response from a proxy and it says it'll
       * close down after this transfer.
       */
      connclose(conn, "Proxy-Connection: asked to close after done");
      infof(data, "HTTP/1.1 proxy connection set close!\n");
    }
    else if((conn->httpversion == 10) &&
            Curl_compareheader(k->p, "Connection:", "keep-alive")) {
      /*
       * A HTTP/1.0 reply with the 'Connection: keep-alive' line
       * tells us the connection will be kept alive for our
       * pleasure.  Default action for 1.0 is to close.
       *
       * [RFC2068, section 19.7.1] */
      connkeep(conn, "Connection keep-alive");
      infof(data, "HTTP/1.0 connection set to keep alive!\n");
    }
    else if(Curl_compareheader(k->p, "Connection:", "close")) {
      /*
       * [RFC 2616, section 8.1.2.1]
       * "Connection: close" is HTTP/1.1 language and means that
       * the connection will close when this request has been
       * served.
       */
      streamclose(conn, "Connection: close used");
    }
    else if(checkprefix("Transfer-Encoding:", k->p)) {
      /* One or more encodings. We check for chunked and/or a compression
         algorithm. */
      /*
       * [RFC 2616, section 3.6.1] A 'chunked' transfer encoding
       * means that the server will send a series of "chunks". Each
       * chunk starts with line with info (including size of the
       * coming block) (terminated with CRLF), then a block of data
       * with the previously mentioned size. There can be any amount
       * of chunks, and a chunk-data set to zero signals the
       * end-of-chunks. */

      char *start;

      /* Find the first non-space letter */
      start = k->p + 18;

      for(;;) {
        /* skip whitespaces and commas */
        while(*start && (ISSPACE(*start) || (*start == ',')))
          start++;

        if(checkprefix("chunked", start)) {
          k->chunk = TRUE; /* chunks coming our way */

          /* init our chunky engine */
          Curl_httpchunk_init(conn);

          start += 7;
        }

        if(k->auto_decoding)
          /* TODO: we only support the first mentioned compression for now */
          break;

        if(checkprefix("identity", start)) {
          k->auto_decoding = IDENTITY;
          start += 8;
        }
        else if(checkprefix("deflate", start)) {
          k->auto_decoding = DEFLATE;
          start += 7;
        }
        else if(checkprefix("gzip", start)) {
          k->auto_decoding = GZIP;
          start += 4;
        }
        else if(checkprefix("x-gzip", start)) {
          k->auto_decoding = GZIP;
          start += 6;
        }
        else
          /* unknown! */
          break;

      }

    }
    else if(checkprefix("Content-Encoding:", k->p) &&
            data->set.str[STRING_ENCODING]) {
      /*
       * Process Content-Encoding. Look for the values: identity,
       * gzip, deflate, compress, x-gzip and x-compress. x-gzip and
       * x-compress are the same as gzip and compress. (Sec 3.5 RFC
       * 2616). zlib cannot handle compress.  However, errors are
       * handled further down when the response body is processed
       */
      char *start;

      /* Find the first non-space letter */
      start = k->p + 17;
      while(*start && ISSPACE(*start))
        start++;

      /* Record the content-encoding for later use */
      if(checkprefix("identity", start))
        k->auto_decoding = IDENTITY;
      else if(checkprefix("deflate", start))
        k->auto_decoding = DEFLATE;
      else if(checkprefix("gzip", start)
              || checkprefix("x-gzip", start))
        k->auto_decoding = GZIP;
    }
    else if(checkprefix("Content-Range:", k->p)) {
      /* Content-Range: bytes [num]-
         Content-Range: bytes: [num]-
         Content-Range: [num]-
         Content-Range: [asterisk]/[total]

         The second format was added since Sun's webserver
         JavaWebServer/1.1.1 obviously sends the header this way!
         The third added since some servers use that!
         The forth means the requested range was unsatisfied.
      */

      char *ptr = k->p + 14;

      /* Move forward until first digit or asterisk */
      while(*ptr && !ISDIGIT(*ptr) && *ptr != '*')
        ptr++;

      /* if it truly stopped on a digit */
      if(ISDIGIT(*ptr)) {
        if(!curlx_strtoofft(ptr, NULL, 10, &k->offset)) {
          if(data->state.resume_from == k->offset)
            /* we asked for a resume and we got it */
            k->content_range = TRUE;
        }
      }
      else
        data->state.resume_from = 0; /* get everything */
    }
#if !defined(CURL_DISABLE_COOKIES)
    else if(data->cookies &&
            checkprefix("Set-Cookie:", k->p)) {
      Curl_share_lock(data, CURL_LOCK_DATA_COOKIE,
                      CURL_LOCK_ACCESS_SINGLE);
      Curl_cookie_add(data,
                      data->cookies, TRUE, k->p + 11,
                      /* If there is a custom-set Host: name, use it
                         here, or else use real peer host name. */
                      conn->allocptr.cookiehost?
                      conn->allocptr.cookiehost:conn->host.name,
                      data->state.path);
      Curl_share_unlock(data, CURL_LOCK_DATA_COOKIE);
    }
#endif
    else if(checkprefix("Last-Modified:", k->p) &&
            (data->set.timecondition || data->set.get_filetime) ) {
      time_t secs = time(NULL);
      k->timeofdoc = curl_getdate(k->p + strlen("Last-Modified:"),
                                  &secs);
      if(data->set.get_filetime)
        data->info.filetime = (long)k->timeofdoc;
    }
    else if((checkprefix("WWW-Authenticate:", k->p) &&
             (401 == k->httpcode)) ||
            (checkprefix("Proxy-authenticate:", k->p) &&
             (407 == k->httpcode))) {

      bool proxy = (k->httpcode == 407) ? TRUE : FALSE;
      char *auth = Curl_copy_header_value(k->p);
      if(!auth)
        return CURLE_OUT_OF_MEMORY;

      result = Curl_http_input_auth(conn, proxy, auth);

      free(auth);

      if(result)
        return result;
    }
    else if((k->httpcode >= 300 && k->httpcode < 400) &&
            checkprefix("Location:", k->p) &&
            !data->req.location) {
      /* this is the URL that the server advises us to use instead */
      char *location = Curl_copy_header_value(k->p);
      if(!location)
        return CURLE_OUT_OF_MEMORY;
      if(!*location)
        /* ignore empty data */
        free(location);
      else {
        data->req.location = location;

        if(data->set.http_follow_location) {
          DEBUGASSERT(!data->req.newurl);
          data->req.newurl = strdup(data->req.location); /* clone */
          if(!data->req.newurl)
            return CURLE_OUT_OF_MEMORY;

          /* some cases of POST and PUT etc needs to rewind the data
             stream at this point */
          result = http_perhapsrewind(conn);
          if(result)
            return result;
        }
      }
    }
    else if(conn->handler->protocol & CURLPROTO_RTSP) {
      result = Curl_rtsp_parseheader(conn, k->p);
      if(result)
        return result;
    }

    /*
     * End of header-checks. Write them to the client.
     */

    writetype = CLIENTWRITE_HEADER;
    if(data->set.include_header)
      writetype |= CLIENTWRITE_BODY;

    if(data->set.verbose)
      Curl_debug(data, CURLINFO_HEADER_IN,
                 k->p, (size_t)k->hbuflen, conn);

    result = Curl_client_write(conn, writetype, k->p, k->hbuflen);
    if(result)
      return result;

    data->info.header_size += (long)k->hbuflen;
    data->req.headerbytecount += (long)k->hbuflen;

    /* reset hbufp pointer && hbuflen */
    k->hbufp = data->state.headerbuff;
    k->hbuflen = 0;
  }
  while(*k->str); /* header line within buffer */

  /* We might have reached the end of the header part here, but
     there might be a non-header part left in the end of the read
     buffer. */

  return CURLE_OK;
}

#endif /* CURL_DISABLE_HTTP */