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
|
/*-
* Copyright (c) 2003-2007 Tim Kientzle
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/*
* This file contains the "essential" portions of the read API, that
* is, stuff that will probably always be used by any client that
* actually needs to read an archive. Optional pieces have been, as
* far as possible, separated out into separate files to avoid
* needlessly bloating statically-linked clients.
*/
#include "archive_platform.h"
__FBSDID("$FreeBSD$");
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#include <stdio.h>
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "archive.h"
#include "archive_entry.h"
#include "archive_private.h"
#include "archive_read_private.h"
#define minimum(a, b) (a < b ? a : b)
static int build_stream(struct archive_read *);
static int choose_format(struct archive_read *);
static struct archive_vtable *archive_read_vtable(void);
static int _archive_read_close(struct archive *);
static int _archive_read_finish(struct archive *);
static struct archive_vtable *
archive_read_vtable(void)
{
static struct archive_vtable av;
static int inited = 0;
if (!inited) {
av.archive_finish = _archive_read_finish;
av.archive_close = _archive_read_close;
}
return (&av);
}
/*
* Allocate, initialize and return a struct archive object.
*/
struct archive *
archive_read_new(void)
{
struct archive_read *a;
a = (struct archive_read *)malloc(sizeof(*a));
if (a == NULL)
return (NULL);
memset(a, 0, sizeof(*a));
a->archive.magic = ARCHIVE_READ_MAGIC;
a->archive.state = ARCHIVE_STATE_NEW;
a->entry = archive_entry_new();
a->archive.vtable = archive_read_vtable();
return (&a->archive);
}
/*
* Record the do-not-extract-to file. This belongs in archive_read_extract.c.
*/
void
archive_read_extract_set_skip_file(struct archive *_a, dev_t d, ino_t i)
{
struct archive_read *a = (struct archive_read *)_a;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_ANY,
"archive_read_extract_set_skip_file");
a->skip_file_dev = d;
a->skip_file_ino = i;
}
/*
* Set read options for the format.
*/
int
archive_read_set_format_options(struct archive *_a, const char *s)
{
struct archive_read *a;
char key[64], val[64];
int len, r;
a = (struct archive_read *)_a;
if (a->format == NULL || a->format->options == NULL ||
a->format->name == NULL)
/* This format does not support option. */
return (ARCHIVE_OK);
while ((len = __archive_parse_options(s, a->format->name,
sizeof(key), key, sizeof(val), val)) > 0) {
if (val[0] == '\0')
r = a->format->options(a, key, NULL);
else
r = a->format->options(a, key, val);
if (r == ARCHIVE_FATAL)
return (r);
s += len;
}
if (len < 0) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Illegal format options.");
return (ARCHIVE_WARN);
}
return (ARCHIVE_OK);
}
/*
* Set read options for the filter.
*/
int
archive_read_set_filter_options(struct archive *_a, const char *s)
{
struct archive_read *a;
struct archive_read_filter *filter;
struct archive_read_filter_bidder *bidder;
char key[64], val[64];
int len, r;
a = (struct archive_read *)_a;
filter = a->filter;
len = 0;
for (filter = a->filter; filter != NULL; filter = filter->upstream) {
bidder = filter->bidder;
if (bidder->options == NULL)
/* This bidder does not support option */
continue;
while ((len = __archive_parse_options(s, filter->name,
sizeof(key), key, sizeof(val), val)) > 0) {
if (val[0] == '\0')
r = bidder->options(bidder, key, NULL);
else
r = bidder->options(bidder, key, val);
if (r == ARCHIVE_FATAL)
return (r);
s += len;
}
}
if (len < 0) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC,
"Illegal format options.");
return (ARCHIVE_WARN);
}
return (ARCHIVE_OK);
}
/*
* Set read options for the format and the filter.
*/
int
archive_read_set_options(struct archive *_a, const char *s)
{
int r;
r = archive_read_set_format_options(_a, s);
if (r != ARCHIVE_OK)
return (r);
r = archive_read_set_filter_options(_a, s);
if (r != ARCHIVE_OK)
return (r);
return (ARCHIVE_OK);
}
/*
* Open the archive
*/
int
archive_read_open(struct archive *a, void *client_data,
archive_open_callback *client_opener, archive_read_callback *client_reader,
archive_close_callback *client_closer)
{
/* Old archive_read_open() is just a thin shell around
* archive_read_open2. */
return archive_read_open2(a, client_data, client_opener,
client_reader, NULL, client_closer);
}
static ssize_t
client_read_proxy(struct archive_read_filter *self, const void **buff)
{
ssize_t r;
r = (self->archive->client.reader)(&self->archive->archive,
self->data, buff);
self->archive->archive.raw_position += r;
return (r);
}
static int64_t
client_skip_proxy(struct archive_read_filter *self, int64_t request)
{
int64_t r;
r = (self->archive->client.skipper)(&self->archive->archive,
self->data, request);
self->archive->archive.raw_position += r;
return (r);
}
static int
client_close_proxy(struct archive_read_filter *self)
{
int r = ARCHIVE_OK;
if (self->archive->client.closer != NULL)
r = (self->archive->client.closer)((struct archive *)self->archive,
self->data);
self->data = NULL;
return (r);
}
int
archive_read_open2(struct archive *_a, void *client_data,
archive_open_callback *client_opener,
archive_read_callback *client_reader,
archive_skip_callback *client_skipper,
archive_close_callback *client_closer)
{
struct archive_read *a = (struct archive_read *)_a;
struct archive_read_filter *filter;
int e;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW,
"archive_read_open");
if (client_reader == NULL)
__archive_errx(1,
"No reader function provided to archive_read_open");
/* Open data source. */
if (client_opener != NULL) {
e =(client_opener)(&a->archive, client_data);
if (e != 0) {
/* If the open failed, call the closer to clean up. */
if (client_closer)
(client_closer)(&a->archive, client_data);
return (e);
}
}
/* Save the client functions and mock up the initial source. */
a->client.reader = client_reader;
a->client.skipper = client_skipper;
a->client.closer = client_closer;
filter = calloc(1, sizeof(*filter));
if (filter == NULL)
return (ARCHIVE_FATAL);
filter->bidder = NULL;
filter->upstream = NULL;
filter->archive = a;
filter->data = client_data;
filter->read = client_read_proxy;
filter->skip = client_skip_proxy;
filter->close = client_close_proxy;
filter->name = "none";
filter->code = ARCHIVE_COMPRESSION_NONE;
a->filter = filter;
/* Build out the input pipeline. */
e = build_stream(a);
if (e == ARCHIVE_OK)
a->archive.state = ARCHIVE_STATE_HEADER;
return (e);
}
/*
* Allow each registered stream transform to bid on whether
* it wants to handle this stream. Repeat until we've finished
* building the pipeline.
*/
static int
build_stream(struct archive_read *a)
{
int number_bidders, i, bid, best_bid;
struct archive_read_filter_bidder *bidder, *best_bidder;
struct archive_read_filter *filter;
int r;
for (;;) {
number_bidders = sizeof(a->bidders) / sizeof(a->bidders[0]);
best_bid = 0;
best_bidder = NULL;
bidder = a->bidders;
for (i = 0; i < number_bidders; i++, bidder++) {
if (bidder->bid != NULL) {
bid = (bidder->bid)(bidder, a->filter);
if (bid > best_bid) {
best_bid = bid;
best_bidder = bidder;
}
}
}
/* If no bidder, we're done. */
if (best_bidder == NULL) {
a->archive.compression_name = a->filter->name;
a->archive.compression_code = a->filter->code;
return (ARCHIVE_OK);
}
filter
= (struct archive_read_filter *)calloc(1, sizeof(*filter));
if (filter == NULL)
return (ARCHIVE_FATAL);
filter->bidder = best_bidder;
filter->archive = a;
filter->upstream = a->filter;
r = (best_bidder->init)(filter);
if (r != ARCHIVE_OK) {
free(filter);
return (r);
}
a->filter = filter;
}
}
/*
* Read header of next entry.
*/
int
archive_read_next_header(struct archive *_a, struct archive_entry **entryp)
{
struct archive_read *a = (struct archive_read *)_a;
struct archive_entry *entry;
int slot, ret;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC,
ARCHIVE_STATE_HEADER | ARCHIVE_STATE_DATA,
"archive_read_next_header");
*entryp = NULL;
entry = a->entry;
archive_entry_clear(entry);
archive_clear_error(&a->archive);
/*
* If no format has yet been chosen, choose one.
*/
if (a->format == NULL) {
slot = choose_format(a);
if (slot < 0) {
a->archive.state = ARCHIVE_STATE_FATAL;
return (ARCHIVE_FATAL);
}
a->format = &(a->formats[slot]);
}
/*
* If client didn't consume entire data, skip any remainder
* (This is especially important for GNU incremental directories.)
*/
if (a->archive.state == ARCHIVE_STATE_DATA) {
ret = archive_read_data_skip(&a->archive);
if (ret == ARCHIVE_EOF) {
archive_set_error(&a->archive, EIO, "Premature end-of-file.");
a->archive.state = ARCHIVE_STATE_FATAL;
return (ARCHIVE_FATAL);
}
if (ret != ARCHIVE_OK)
return (ret);
}
/* Record start-of-header. */
a->header_position = a->archive.file_position;
ret = (a->format->read_header)(a, entry);
/*
* EOF and FATAL are persistent at this layer. By
* modifying the state, we guarantee that future calls to
* read a header or read data will fail.
*/
switch (ret) {
case ARCHIVE_EOF:
a->archive.state = ARCHIVE_STATE_EOF;
break;
case ARCHIVE_OK:
a->archive.state = ARCHIVE_STATE_DATA;
break;
case ARCHIVE_WARN:
a->archive.state = ARCHIVE_STATE_DATA;
break;
case ARCHIVE_RETRY:
break;
case ARCHIVE_FATAL:
a->archive.state = ARCHIVE_STATE_FATAL;
break;
}
*entryp = entry;
a->read_data_output_offset = 0;
a->read_data_remaining = 0;
return (ret);
}
/*
* Allow each registered format to bid on whether it wants to handle
* the next entry. Return index of winning bidder.
*/
static int
choose_format(struct archive_read *a)
{
int slots;
int i;
int bid, best_bid;
int best_bid_slot;
slots = sizeof(a->formats) / sizeof(a->formats[0]);
best_bid = -1;
best_bid_slot = -1;
/* Set up a->format and a->pformat_data for convenience of bidders. */
a->format = &(a->formats[0]);
for (i = 0; i < slots; i++, a->format++) {
if (a->format->bid) {
bid = (a->format->bid)(a);
if (bid == ARCHIVE_FATAL)
return (ARCHIVE_FATAL);
if ((bid > best_bid) || (best_bid_slot < 0)) {
best_bid = bid;
best_bid_slot = i;
}
}
}
/*
* There were no bidders; this is a serious programmer error
* and demands a quick and definitive abort.
*/
if (best_bid_slot < 0)
__archive_errx(1, "No formats were registered; you must "
"invoke at least one archive_read_support_format_XXX "
"function in order to successfully read an archive.");
/*
* There were bidders, but no non-zero bids; this means we
* can't support this stream.
*/
if (best_bid < 1) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Unrecognized archive format");
return (ARCHIVE_FATAL);
}
return (best_bid_slot);
}
/*
* Return the file offset (within the uncompressed data stream) where
* the last header started.
*/
int64_t
archive_read_header_position(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC,
ARCHIVE_STATE_ANY, "archive_read_header_position");
return (a->header_position);
}
/*
* Read data from an archive entry, using a read(2)-style interface.
* This is a convenience routine that just calls
* archive_read_data_block and copies the results into the client
* buffer, filling any gaps with zero bytes. Clients using this
* API can be completely ignorant of sparse-file issues; sparse files
* will simply be padded with nulls.
*
* DO NOT intermingle calls to this function and archive_read_data_block
* to read a single entry body.
*/
ssize_t
archive_read_data(struct archive *_a, void *buff, size_t s)
{
struct archive_read *a = (struct archive_read *)_a;
char *dest;
const void *read_buf;
size_t bytes_read;
size_t len;
int r;
bytes_read = 0;
dest = (char *)buff;
while (s > 0) {
if (a->read_data_remaining == 0) {
read_buf = a->read_data_block;
r = archive_read_data_block(&a->archive, &read_buf,
&a->read_data_remaining, &a->read_data_offset);
a->read_data_block = read_buf;
if (r == ARCHIVE_EOF)
return (bytes_read);
/*
* Error codes are all negative, so the status
* return here cannot be confused with a valid
* byte count. (ARCHIVE_OK is zero.)
*/
if (r < ARCHIVE_OK)
return (r);
}
if (a->read_data_offset < a->read_data_output_offset) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_FILE_FORMAT,
"Encountered out-of-order sparse blocks");
return (ARCHIVE_RETRY);
}
/* Compute the amount of zero padding needed. */
if (a->read_data_output_offset + (off_t)s <
a->read_data_offset) {
len = s;
} else if (a->read_data_output_offset <
a->read_data_offset) {
len = a->read_data_offset -
a->read_data_output_offset;
} else
len = 0;
/* Add zeroes. */
memset(dest, 0, len);
s -= len;
a->read_data_output_offset += len;
dest += len;
bytes_read += len;
/* Copy data if there is any space left. */
if (s > 0) {
len = a->read_data_remaining;
if (len > s)
len = s;
memcpy(dest, a->read_data_block, len);
s -= len;
a->read_data_block += len;
a->read_data_remaining -= len;
a->read_data_output_offset += len;
a->read_data_offset += len;
dest += len;
bytes_read += len;
}
}
return (bytes_read);
}
#if ARCHIVE_API_VERSION < 3
/*
* Obsolete function provided for compatibility only. Note that the API
* of this function doesn't allow the caller to detect if the remaining
* data from the archive entry is shorter than the buffer provided, or
* even if an error occurred while reading data.
*/
int
archive_read_data_into_buffer(struct archive *a, void *d, ssize_t len)
{
archive_read_data(a, d, len);
return (ARCHIVE_OK);
}
#endif
/*
* Skip over all remaining data in this entry.
*/
int
archive_read_data_skip(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
int r;
const void *buff;
size_t size;
off_t offset;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA,
"archive_read_data_skip");
if (a->format->read_data_skip != NULL)
r = (a->format->read_data_skip)(a);
else {
while ((r = archive_read_data_block(&a->archive,
&buff, &size, &offset))
== ARCHIVE_OK)
;
}
if (r == ARCHIVE_EOF)
r = ARCHIVE_OK;
a->archive.state = ARCHIVE_STATE_HEADER;
return (r);
}
/*
* Read the next block of entry data from the archive.
* This is a zero-copy interface; the client receives a pointer,
* size, and file offset of the next available block of data.
*
* Returns ARCHIVE_OK if the operation is successful, ARCHIVE_EOF if
* the end of entry is encountered.
*/
int
archive_read_data_block(struct archive *_a,
const void **buff, size_t *size, off_t *offset)
{
struct archive_read *a = (struct archive_read *)_a;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_DATA,
"archive_read_data_block");
if (a->format->read_data == NULL) {
archive_set_error(&a->archive, ARCHIVE_ERRNO_PROGRAMMER,
"Internal error: "
"No format_read_data_block function registered");
return (ARCHIVE_FATAL);
}
return (a->format->read_data)(a, buff, size, offset);
}
/*
* Close the file and release most resources.
*
* Be careful: client might just call read_new and then read_finish.
* Don't assume we actually read anything or performed any non-trivial
* initialization.
*/
static int
_archive_read_close(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
int r = ARCHIVE_OK, r1 = ARCHIVE_OK;
size_t i, n;
__archive_check_magic(&a->archive, ARCHIVE_READ_MAGIC,
ARCHIVE_STATE_ANY, "archive_read_close");
a->archive.state = ARCHIVE_STATE_CLOSED;
/* Call cleanup functions registered by optional components. */
if (a->cleanup_archive_extract != NULL)
r = (a->cleanup_archive_extract)(a);
/* TODO: Clean up the formatters. */
/* Clean up the filter pipeline. */
while (a->filter != NULL) {
struct archive_read_filter *t = a->filter->upstream;
if (a->filter->close != NULL) {
r1 = (a->filter->close)(a->filter);
if (r1 < r)
r = r1;
}
free(a->filter->buffer);
free(a->filter);
a->filter = t;
}
/* Release the bidder objects. */
n = sizeof(a->bidders)/sizeof(a->bidders[0]);
for (i = 0; i < n; i++) {
if (a->bidders[i].free != NULL) {
r1 = (a->bidders[i].free)(&a->bidders[i]);
if (r1 < r)
r = r1;
}
}
return (r);
}
/*
* Release memory and other resources.
*/
int
_archive_read_finish(struct archive *_a)
{
struct archive_read *a = (struct archive_read *)_a;
int i;
int slots;
int r = ARCHIVE_OK;
__archive_check_magic(_a, ARCHIVE_READ_MAGIC, ARCHIVE_STATE_ANY,
"archive_read_finish");
if (a->archive.state != ARCHIVE_STATE_CLOSED)
r = archive_read_close(&a->archive);
/* Cleanup format-specific data. */
slots = sizeof(a->formats) / sizeof(a->formats[0]);
for (i = 0; i < slots; i++) {
a->format = &(a->formats[i]);
if (a->formats[i].cleanup)
(a->formats[i].cleanup)(a);
}
archive_string_free(&a->archive.error_string);
if (a->entry)
archive_entry_free(a->entry);
a->archive.magic = 0;
free(a);
#if ARCHIVE_API_VERSION > 1
return (r);
#endif
}
/*
* Used internally by read format handlers to register their bid and
* initialization functions.
*/
int
__archive_read_register_format(struct archive_read *a,
void *format_data,
const char *name,
int (*bid)(struct archive_read *),
int (*options)(struct archive_read *, const char *, const char *),
int (*read_header)(struct archive_read *, struct archive_entry *),
int (*read_data)(struct archive_read *, const void **, size_t *, off_t *),
int (*read_data_skip)(struct archive_read *),
int (*cleanup)(struct archive_read *))
{
int i, number_slots;
__archive_check_magic(&a->archive,
ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW,
"__archive_read_register_format");
number_slots = sizeof(a->formats) / sizeof(a->formats[0]);
for (i = 0; i < number_slots; i++) {
if (a->formats[i].bid == bid)
return (ARCHIVE_WARN); /* We've already installed */
if (a->formats[i].bid == NULL) {
a->formats[i].bid = bid;
a->formats[i].options = options;
a->formats[i].read_header = read_header;
a->formats[i].read_data = read_data;
a->formats[i].read_data_skip = read_data_skip;
a->formats[i].cleanup = cleanup;
a->formats[i].data = format_data;
a->formats[i].name = name;
return (ARCHIVE_OK);
}
}
__archive_errx(1, "Not enough slots for format registration");
return (ARCHIVE_FATAL); /* Never actually called. */
}
/*
* Used internally by decompression routines to register their bid and
* initialization functions.
*/
struct archive_read_filter_bidder *
__archive_read_get_bidder(struct archive_read *a)
{
int i, number_slots;
__archive_check_magic(&a->archive,
ARCHIVE_READ_MAGIC, ARCHIVE_STATE_NEW,
"__archive_read_get_bidder");
number_slots = sizeof(a->bidders) / sizeof(a->bidders[0]);
for (i = 0; i < number_slots; i++) {
if (a->bidders[i].bid == NULL)
return (a->bidders + i);
}
__archive_errx(1, "Not enough slots for compression registration");
return (NULL); /* Never actually executed. */
}
/*
* The next three functions comprise the peek/consume internal I/O
* system used by archive format readers. This system allows fairly
* flexible read-ahead and allows the I/O code to operate in a
* zero-copy manner most of the time.
*
* In the ideal case, filters generate blocks of data
* and __archive_read_ahead() just returns pointers directly into
* those blocks. Then __archive_read_consume() just bumps those
* pointers. Only if your request would span blocks does the I/O
* layer use a copy buffer to provide you with a contiguous block of
* data. The __archive_read_skip() is an optimization; it scans ahead
* very quickly (it usually translates into a seek() operation if
* you're reading uncompressed disk files).
*
* A couple of useful idioms:
* * "I just want some data." Ask for 1 byte and pay attention to
* the "number of bytes available" from __archive_read_ahead().
* You can consume more than you asked for; you just can't consume
* more than is available. If you consume everything that's
* immediately available, the next read_ahead() call will pull
* the next block.
* * "I want to output a large block of data." As above, ask for 1 byte,
* emit all that's available (up to whatever limit you have), then
* repeat until you're done.
* * "I want to peek ahead by a large amount." Ask for 4k or so, then
* double and repeat until you get an error or have enough. Note
* that the I/O layer will likely end up expanding its copy buffer
* to fit your request, so use this technique cautiously. This
* technique is used, for example, by some of the format tasting
* code that has uncertain look-ahead needs.
*
* TODO: Someday, provide a more generic __archive_read_seek() for
* those cases where it's useful. This is tricky because there are lots
* of cases where seek() is not available (reading gzip data from a
* network socket, for instance), so there needs to be a good way to
* communicate whether seek() is available and users of that interface
* need to use non-seeking strategies whenever seek() is not available.
*/
/*
* Looks ahead in the input stream:
* * If 'avail' pointer is provided, that returns number of bytes available
* in the current buffer, which may be much larger than requested.
* * If end-of-file, *avail gets set to zero.
* * If error, *avail gets error code.
* * If request can be met, returns pointer to data, returns NULL
* if request is not met.
*
* Note: If you just want "some data", ask for 1 byte and pay attention
* to *avail, which will have the actual amount available. If you
* know exactly how many bytes you need, just ask for that and treat
* a NULL return as an error.
*
* Important: This does NOT move the file pointer. See
* __archive_read_consume() below.
*/
/*
* This is tricky. We need to provide our clients with pointers to
* contiguous blocks of memory but we want to avoid copying whenever
* possible.
*
* Mostly, this code returns pointers directly into the block of data
* provided by the client_read routine. It can do this unless the
* request would split across blocks. In that case, we have to copy
* into an internal buffer to combine reads.
*/
const void *
__archive_read_ahead(struct archive_read *a, size_t min, ssize_t *avail)
{
return (__archive_read_filter_ahead(a->filter, min, avail));
}
const void *
__archive_read_filter_ahead(struct archive_read_filter *filter,
size_t min, ssize_t *avail)
{
ssize_t bytes_read;
size_t tocopy;
if (filter->fatal) {
if (avail)
*avail = ARCHIVE_FATAL;
return (NULL);
}
/*
* Keep pulling more data until we can satisfy the request.
*/
for (;;) {
/*
* If we can satisfy from the copy buffer, we're done.
*/
if (filter->avail >= min) {
if (avail != NULL)
*avail = filter->avail;
return (filter->next);
}
/*
* We can satisfy directly from client buffer if everything
* currently in the copy buffer is still in the client buffer.
*/
if (filter->client_total >= filter->client_avail + filter->avail
&& filter->client_avail + filter->avail >= min) {
/* "Roll back" to client buffer. */
filter->client_avail += filter->avail;
filter->client_next -= filter->avail;
/* Copy buffer is now empty. */
filter->avail = 0;
filter->next = filter->buffer;
/* Return data from client buffer. */
if (avail != NULL)
*avail = filter->client_avail;
return (filter->client_next);
}
/* Move data forward in copy buffer if necessary. */
if (filter->next > filter->buffer &&
filter->next + min > filter->buffer + filter->buffer_size) {
if (filter->avail > 0)
memmove(filter->buffer, filter->next, filter->avail);
filter->next = filter->buffer;
}
/* If we've used up the client data, get more. */
if (filter->client_avail <= 0) {
if (filter->end_of_file) {
if (avail != NULL)
*avail = 0;
return (NULL);
}
bytes_read = (filter->read)(filter,
&filter->client_buff);
if (bytes_read < 0) { /* Read error. */
filter->client_total = filter->client_avail = 0;
filter->client_next = filter->client_buff = NULL;
filter->fatal = 1;
if (avail != NULL)
*avail = ARCHIVE_FATAL;
return (NULL);
}
if (bytes_read == 0) { /* Premature end-of-file. */
filter->client_total = filter->client_avail = 0;
filter->client_next = filter->client_buff = NULL;
filter->end_of_file = 1;
/* Return whatever we do have. */
if (avail != NULL)
*avail = filter->avail;
return (NULL);
}
filter->position += bytes_read;
filter->client_total = bytes_read;
filter->client_avail = filter->client_total;
filter->client_next = filter->client_buff;
}
else
{
/*
* We can't satisfy the request from the copy
* buffer or the existing client data, so we
* need to copy more client data over to the
* copy buffer.
*/
/* Ensure the buffer is big enough. */
if (min > filter->buffer_size) {
size_t s, t;
char *p;
/* Double the buffer; watch for overflow. */
s = t = filter->buffer_size;
if (s == 0)
s = min;
while (s < min) {
t *= 2;
if (t <= s) { /* Integer overflow! */
archive_set_error(
&filter->archive->archive,
ENOMEM,
"Unable to allocate copy buffer");
filter->fatal = 1;
if (avail != NULL)
*avail = ARCHIVE_FATAL;
return (NULL);
}
s = t;
}
/* Now s >= min, so allocate a new buffer. */
p = (char *)malloc(s);
if (p == NULL) {
archive_set_error(
&filter->archive->archive,
ENOMEM,
"Unable to allocate copy buffer");
filter->fatal = 1;
if (avail != NULL)
*avail = ARCHIVE_FATAL;
return (NULL);
}
/* Move data into newly-enlarged buffer. */
if (filter->avail > 0)
memmove(p, filter->next, filter->avail);
free(filter->buffer);
filter->next = filter->buffer = p;
filter->buffer_size = s;
}
/* We can add client data to copy buffer. */
/* First estimate: copy to fill rest of buffer. */
tocopy = (filter->buffer + filter->buffer_size)
- (filter->next + filter->avail);
/* Don't waste time buffering more than we need to. */
if (tocopy + filter->avail > min)
tocopy = min - filter->avail;
/* Don't copy more than is available. */
if (tocopy > filter->client_avail)
tocopy = filter->client_avail;
memcpy(filter->next + filter->avail, filter->client_next,
tocopy);
/* Remove this data from client buffer. */
filter->client_next += tocopy;
filter->client_avail -= tocopy;
/* add it to copy buffer. */
filter->avail += tocopy;
}
}
}
/*
* Move the file pointer forward. This should be called after
* __archive_read_ahead() returns data to you. Don't try to move
* ahead by more than the amount of data available according to
* __archive_read_ahead().
*/
/*
* Mark the appropriate data as used. Note that the request here will
* often be much smaller than the size of the previous read_ahead
* request.
*/
ssize_t
__archive_read_consume(struct archive_read *a, size_t request)
{
ssize_t r;
r = __archive_read_filter_consume(a->filter, request);
a->archive.file_position += r;
return (r);
}
ssize_t
__archive_read_filter_consume(struct archive_read_filter * filter,
size_t request)
{
if (filter->avail > 0) {
/* Read came from copy buffer. */
filter->next += request;
filter->avail -= request;
} else {
/* Read came from client buffer. */
filter->client_next += request;
filter->client_avail -= request;
}
return (request);
}
/*
* Move the file pointer ahead by an arbitrary amount. If you're
* reading uncompressed data from a disk file, this will actually
* translate into a seek() operation. Even in cases where seek()
* isn't feasible, this at least pushes the read-and-discard loop
* down closer to the data source.
*/
int64_t
__archive_read_skip(struct archive_read *a, int64_t request)
{
return (__archive_read_filter_skip(a->filter, request));
}
int64_t
__archive_read_filter_skip(struct archive_read_filter *filter, int64_t request)
{
off_t bytes_skipped, total_bytes_skipped = 0;
size_t min;
if (filter->fatal)
return (-1);
/*
* If there is data in the buffers already, use that first.
*/
if (filter->avail > 0) {
min = minimum(request, (off_t)filter->avail);
bytes_skipped = __archive_read_consume(filter->archive, min);
request -= bytes_skipped;
total_bytes_skipped += bytes_skipped;
}
if (filter->client_avail > 0) {
min = minimum(request, (off_t)filter->client_avail);
bytes_skipped = __archive_read_consume(filter->archive, min);
request -= bytes_skipped;
total_bytes_skipped += bytes_skipped;
}
if (request == 0)
return (total_bytes_skipped);
/*
* If a client_skipper was provided, try that first.
*/
#if ARCHIVE_API_VERSION < 2
if ((filter->skip != NULL) && (request < SSIZE_MAX)) {
#else
if (filter->skip != NULL) {
#endif
bytes_skipped = (filter->skip)(filter, request);
if (bytes_skipped < 0) { /* error */
filter->client_total = filter->client_avail = 0;
filter->client_next = filter->client_buff = NULL;
filter->fatal = 1;
return (bytes_skipped);
}
filter->archive->archive.file_position += bytes_skipped;
total_bytes_skipped += bytes_skipped;
request -= bytes_skipped;
filter->client_next = filter->client_buff;
filter->client_avail = filter->client_total = 0;
}
/*
* Note that client_skipper will usually not satisfy the
* full request (due to low-level blocking concerns),
* so even if client_skipper is provided, we may still
* have to use ordinary reads to finish out the request.
*/
while (request > 0) {
const void* dummy_buffer;
ssize_t bytes_read;
dummy_buffer = __archive_read_ahead(filter->archive,
1, &bytes_read);
if (bytes_read < 0)
return (bytes_read);
if (bytes_read == 0) {
/* We hit EOF before we satisfied the skip request. */
archive_set_error(&filter->archive->archive,
ARCHIVE_ERRNO_MISC,
"Truncated input file (need to skip %jd bytes)",
(intmax_t)request);
return (ARCHIVE_FATAL);
}
min = (size_t)(minimum(bytes_read, request));
bytes_read = __archive_read_consume(filter->archive, min);
total_bytes_skipped += bytes_read;
request -= bytes_read;
}
return (total_bytes_skipped);
}
|