aboutsummaryrefslogtreecommitdiff
path: root/archival/unzip.c
blob: 0a27e5e18afcfb0f54088780bed3a8a702e285a1 (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
/* vi: set sw=4 ts=4: */
/*
 * Mini unzip implementation for busybox
 *
 * Copyright (C) 2004 by Ed Clark
 *
 * Loosely based on original busybox unzip applet by Laurence Anderson.
 * All options and features should work in this version.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this source tree.
 */
/* For reference see
 * http://www.pkware.com/company/standards/appnote/
 * http://www.info-zip.org/pub/infozip/doc/appnote-iz-latest.zip
 *
 * TODO
 * Zip64 + other methods
 */
//config:config UNZIP
//config:	bool "unzip (24 kb)"
//config:	default y
//config:	help
//config:	unzip will list or extract files from a ZIP archive,
//config:	commonly found on DOS/WIN systems. The default behavior
//config:	(with no options) is to extract the archive into the
//config:	current directory.
//config:
//config:config FEATURE_UNZIP_CDF
//config:	bool "Read and use Central Directory data"
//config:	default y
//config:	depends on UNZIP
//config:	help
//config:	If you know that you only need to deal with simple
//config:	ZIP files without deleted/updated files, SFX archives etc,
//config:	you can reduce code size by unselecting this option.
//config:	To support less trivial ZIPs, say Y.
//config:
//config:config FEATURE_UNZIP_BZIP2
//config:	bool "Support compression method 12 (bzip2)"
//config:	default y
//config:	depends on FEATURE_UNZIP_CDF && DESKTOP
// FEATURE_UNZIP_CDF is needed, otherwise we can't find start of next file
// DESKTOP is needed to get back uncompressed length
//config:
//config:config FEATURE_UNZIP_LZMA
//config:	bool "Support compression method 14 (lzma)"
//config:	default y
//config:	depends on FEATURE_UNZIP_CDF && DESKTOP
//config:
//config:config FEATURE_UNZIP_XZ
//config:	bool "Support compression method 95 (xz)"
//config:	default y
//config:	depends on FEATURE_UNZIP_CDF && DESKTOP

//applet:IF_UNZIP(APPLET(unzip, BB_DIR_USR_BIN, BB_SUID_DROP))
//kbuild:lib-$(CONFIG_UNZIP) += unzip.o

//usage:#define unzip_trivial_usage
//usage:       "[-lnojpq] FILE[.zip] [FILE]... [-x FILE...] [-d DIR]"
//usage:#define unzip_full_usage "\n\n"
//usage:       "Extract FILEs from ZIP archive\n"
//usage:     "\n	-l	List contents (with -q for short form)"
//usage:     "\n	-n	Never overwrite files (default: ask)"
//usage:     "\n	-o	Overwrite"
//usage:     "\n	-j	Do not restore paths"
//usage:     "\n	-p	Print to stdout"
//usage:     "\n	-q	Quiet"
//usage:     "\n	-x FILE	Exclude FILEs"
//usage:     "\n	-d DIR	Extract into DIR"

#include "libbb.h"
#include "bb_archive.h"

#if 0
# define dbg(...) bb_error_msg(__VA_ARGS__)
#else
# define dbg(...) ((void)0)
#endif

enum {
#if BB_BIG_ENDIAN
	ZIP_FILEHEADER_MAGIC = 0x504b0304,
	ZIP_CDF_MAGIC        = 0x504b0102, /* CDF item */
	ZIP_CDE_MAGIC        = 0x504b0506, /* End of CDF */
	ZIP_DD_MAGIC         = 0x504b0708,
#else
	ZIP_FILEHEADER_MAGIC = 0x04034b50,
	ZIP_CDF_MAGIC        = 0x02014b50,
	ZIP_CDE_MAGIC        = 0x06054b50,
	ZIP_DD_MAGIC         = 0x08074b50,
#endif
};

#define ZIP_HEADER_LEN 26

typedef union {
	uint8_t raw[ZIP_HEADER_LEN];
	struct {
		uint16_t version;               /* 0-1 */
		uint16_t zip_flags;             /* 2-3 */
		uint16_t method;                /* 4-5 */
		uint16_t modtime;               /* 6-7 */
		uint16_t moddate;               /* 8-9 */
		uint32_t crc32 PACKED;          /* 10-13 */
		uint32_t cmpsize PACKED;        /* 14-17 */
		uint32_t ucmpsize PACKED;       /* 18-21 */
		uint16_t filename_len;          /* 22-23 */
		uint16_t extra_len;             /* 24-25 */
		/* filename follows (not NUL terminated) */
		/* extra field follows */
		/* data follows */
	} fmt PACKED;
} zip_header_t; /* PACKED - gcc 4.2.1 doesn't like it (spews warning) */

#define FIX_ENDIANNESS_ZIP(zip) \
do { if (BB_BIG_ENDIAN) { \
	(zip).fmt.method        = SWAP_LE16((zip).fmt.method      ); \
	(zip).fmt.crc32         = SWAP_LE32((zip).fmt.crc32       ); \
	(zip).fmt.cmpsize       = SWAP_LE32((zip).fmt.cmpsize     ); \
	(zip).fmt.ucmpsize      = SWAP_LE32((zip).fmt.ucmpsize    ); \
	(zip).fmt.filename_len  = SWAP_LE16((zip).fmt.filename_len); \
	(zip).fmt.extra_len     = SWAP_LE16((zip).fmt.extra_len   ); \
}} while (0)

#define CDF_HEADER_LEN 42

typedef union {
	uint8_t raw[CDF_HEADER_LEN];
	struct {
		/* uint32_t signature; 50 4b 01 02 */
		uint16_t version_made_by;       /* 0-1 */
		uint16_t version_needed;        /* 2-3 */
		uint16_t cdf_flags;             /* 4-5 */
		uint16_t method;                /* 6-7 */
		uint16_t modtime;               /* 8-9 */
		uint16_t moddate;               /* 10-11 */
		uint32_t crc32;                 /* 12-15 */
		uint32_t cmpsize;               /* 16-19 */
		uint32_t ucmpsize;              /* 20-23 */
		uint16_t filename_len;          /* 24-25 */
		uint16_t extra_len;             /* 26-27 */
		uint16_t file_comment_length;   /* 28-29 */
		uint16_t disk_number_start;     /* 30-31 */
		uint16_t internal_attributes;   /* 32-33 */
		uint32_t external_attributes PACKED; /* 34-37 */
		uint32_t relative_offset_of_local_header PACKED; /* 38-41 */
		/* filename follows (not NUL terminated) */
		/* extra field follows */
		/* file comment follows */
	} fmt PACKED;
} cdf_header_t;

#define FIX_ENDIANNESS_CDF(cdf) \
do { if (BB_BIG_ENDIAN) { \
	(cdf).fmt.version_made_by = SWAP_LE16((cdf).fmt.version_made_by); \
	(cdf).fmt.version_needed = SWAP_LE16((cdf).fmt.version_needed); \
	(cdf).fmt.method        = SWAP_LE16((cdf).fmt.method      ); \
	(cdf).fmt.modtime       = SWAP_LE16((cdf).fmt.modtime     ); \
	(cdf).fmt.moddate       = SWAP_LE16((cdf).fmt.moddate     ); \
	(cdf).fmt.crc32         = SWAP_LE32((cdf).fmt.crc32       ); \
	(cdf).fmt.cmpsize       = SWAP_LE32((cdf).fmt.cmpsize     ); \
	(cdf).fmt.ucmpsize      = SWAP_LE32((cdf).fmt.ucmpsize    ); \
	(cdf).fmt.filename_len  = SWAP_LE16((cdf).fmt.filename_len); \
	(cdf).fmt.extra_len     = SWAP_LE16((cdf).fmt.extra_len   ); \
	(cdf).fmt.file_comment_length = SWAP_LE16((cdf).fmt.file_comment_length); \
	(cdf).fmt.external_attributes = SWAP_LE32((cdf).fmt.external_attributes); \
}} while (0)

#define CDE_LEN 16

typedef union {
	uint8_t raw[CDE_LEN];
	struct {
		/* uint32_t signature; 50 4b 05 06 */
		uint16_t this_disk_no;
		uint16_t disk_with_cdf_no;
		uint16_t cdf_entries_on_this_disk;
		uint16_t cdf_entries_total;
		uint32_t cdf_size;
		uint32_t cdf_offset;
		/* uint16_t archive_comment_length; */
		/* archive comment follows */
	} fmt PACKED;
} cde_t;

#define FIX_ENDIANNESS_CDE(cde) \
do { if (BB_BIG_ENDIAN) { \
	(cde).fmt.cdf_offset = SWAP_LE32((cde).fmt.cdf_offset); \
}} while (0)

struct BUG {
	/* Check the offset of the last element, not the length.  This leniency
	 * allows for poor packing, whereby the overall struct may be too long,
	 * even though the elements are all in the right place.
	 */
	char BUG_zip_header_must_be_26_bytes[
		offsetof(zip_header_t, fmt.extra_len) + 2
			== ZIP_HEADER_LEN ? 1 : -1];
	char BUG_cdf_header_must_be_42_bytes[
		offsetof(cdf_header_t, fmt.relative_offset_of_local_header) + 4
			== CDF_HEADER_LEN ? 1 : -1];
	char BUG_cde_must_be_16_bytes[
		sizeof(cde_t) == CDE_LEN ? 1 : -1];
};


enum { zip_fd = 3 };


/* This value means that we failed to find CDF */
#define BAD_CDF_OFFSET ((uint32_t)0xffffffff)

#if !ENABLE_FEATURE_UNZIP_CDF

# define find_cdf_offset() BAD_CDF_OFFSET

#else
/* Seen in the wild:
 * Self-extracting PRO2K3XP_32.exe contains 19078464 byte zip archive,
 * where CDE was nearly 48 kbytes before EOF.
 * (Surprisingly, it also apparently has *another* CDE structure
 * closer to the end, with bogus cdf_offset).
 * To make extraction work, bumped PEEK_FROM_END from 16k to 64k.
 */
#define PEEK_FROM_END (64*1024)
/* NB: does not preserve file position! */
static uint32_t find_cdf_offset(void)
{
	cde_t cde;
	unsigned char *buf;
	unsigned char *p;
	off_t end;
	uint32_t found;

	end = lseek(zip_fd, 0, SEEK_END);
	if (end == (off_t) -1)
		return BAD_CDF_OFFSET;

	end -= PEEK_FROM_END;
	if (end < 0)
		end = 0;

	dbg("Looking for cdf_offset starting from 0x%"OFF_FMT"x", end);
	xlseek(zip_fd, end, SEEK_SET);
	buf = xzalloc(PEEK_FROM_END);
	full_read(zip_fd, buf, PEEK_FROM_END);

	found = BAD_CDF_OFFSET;
	p = buf;
	while (p <= buf + PEEK_FROM_END - CDE_LEN - 4) {
		if (*p != 'P') {
			p++;
			continue;
		}
		if (*++p != 'K')
			continue;
		if (*++p != 5)
			continue;
		if (*++p != 6)
			continue;
		/* we found CDE! */
		memcpy(cde.raw, p + 1, CDE_LEN);
		FIX_ENDIANNESS_CDE(cde);
		/*
		 * I've seen .ZIP files with seemingly valid CDEs
		 * where cdf_offset points past EOF - ??
		 * This check ignores such CDEs:
		 */
		if (cde.fmt.cdf_offset < end + (p - buf)) {
			found = cde.fmt.cdf_offset;
			dbg("Possible cdf_offset:0x%x at 0x%"OFF_FMT"x",
				(unsigned)found, end + (p-3 - buf));
			dbg("  cdf_offset+cdf_size:0x%x",
				(unsigned)(found + SWAP_LE32(cde.fmt.cdf_size)));
			/*
			 * We do not "break" here because only the last CDE is valid.
			 * I've seen a .zip archive which contained a .zip file,
			 * uncompressed, and taking the first CDE was using
			 * the CDE inside that file!
			 */
		}
	}
	free(buf);
	dbg("Found cdf_offset:0x%x", (unsigned)found);
	return found;
};

static uint32_t read_next_cdf(uint32_t cdf_offset, cdf_header_t *cdf)
{
	uint32_t magic;

	if (cdf_offset == BAD_CDF_OFFSET)
		return cdf_offset;

	dbg("Reading CDF at 0x%x", (unsigned)cdf_offset);
	xlseek(zip_fd, cdf_offset, SEEK_SET);
	xread(zip_fd, &magic, 4);
	/* Central Directory End? Assume CDF has ended.
	 * (more correct method is to use cde.cdf_entries_total counter)
	 */
	if (magic == ZIP_CDE_MAGIC) {
		dbg("got ZIP_CDE_MAGIC");
		return 0; /* EOF */
	}
	xread(zip_fd, cdf->raw, CDF_HEADER_LEN);

	FIX_ENDIANNESS_CDF(*cdf);
	dbg("  filename_len:%u extra_len:%u file_comment_length:%u",
		(unsigned)cdf->fmt.filename_len,
		(unsigned)cdf->fmt.extra_len,
		(unsigned)cdf->fmt.file_comment_length
	);
	cdf_offset += 4 + CDF_HEADER_LEN
		+ cdf->fmt.filename_len
		+ cdf->fmt.extra_len
		+ cdf->fmt.file_comment_length;

	return cdf_offset;
};
#endif

static void die_if_bad_fnamesize(unsigned sz)
{
	if (sz > 0xfff) /* more than 4k?! no funny business please */
		bb_error_msg_and_die("bad archive");
}

static void unzip_skip(off_t skip)
{
	if (skip != 0)
		if (lseek(zip_fd, skip, SEEK_CUR) == (off_t)-1)
			bb_copyfd_exact_size(zip_fd, -1, skip);
}

static void unzip_create_leading_dirs(const char *fn)
{
	/* Create all leading directories */
	char *name = xstrdup(fn);
	if (bb_make_directory(dirname(name), 0777, FILEUTILS_RECUR)) {
		xfunc_die(); /* bb_make_directory is noisy */
	}
	free(name);
}

#if ENABLE_FEATURE_UNZIP_CDF
static void unzip_extract_symlink(llist_t **symlink_placeholders,
		zip_header_t *zip,
		const char *dst_fn)
{
	char *target;

	die_if_bad_fnamesize(zip->fmt.ucmpsize);

	if (zip->fmt.method == 0) {
		/* Method 0 - stored (not compressed) */
		target = xzalloc(zip->fmt.ucmpsize + 1);
		xread(zip_fd, target, zip->fmt.ucmpsize);
	} else {
#if 1
		bb_error_msg_and_die("compressed symlink is not supported");
#else
		transformer_state_t xstate;
		init_transformer_state(&xstate);
		xstate.mem_output_size_max = zip->fmt.ucmpsize;
		/* ...unpack... */
		if (!xstate.mem_output_buf)
			WTF();
		target = xstate.mem_output_buf;
		target = xrealloc(target, xstate.mem_output_size + 1);
		target[xstate.mem_output_size] = '\0';
#endif
	}
	create_or_remember_symlink(symlink_placeholders,
			target,
			dst_fn);
	free(target);
}
#endif

static void unzip_extract(zip_header_t *zip, int dst_fd)
{
	transformer_state_t xstate;

	if (zip->fmt.method == 0) {
		/* Method 0 - stored (not compressed) */
		off_t size = zip->fmt.ucmpsize;
		if (size)
			bb_copyfd_exact_size(zip_fd, dst_fd, size);
		return;
	}

	init_transformer_state(&xstate);
	xstate.bytes_in = zip->fmt.cmpsize;
	xstate.src_fd = zip_fd;
	xstate.dst_fd = dst_fd;
	if (zip->fmt.method == 8) {
		/* Method 8 - inflate */
		if (inflate_unzip(&xstate) < 0)
			bb_error_msg_and_die("inflate error");
		/* Validate decompression - crc */
		if (zip->fmt.crc32 != (xstate.crc32 ^ 0xffffffffL)) {
			bb_error_msg_and_die("crc error");
		}
	}
#if ENABLE_FEATURE_UNZIP_BZIP2
	else if (zip->fmt.method == 12) {
		/* Tested. Unpacker reads too much, but we use CDF
		 * and will seek to the correct beginning of next file.
		 */
		xstate.bytes_out = unpack_bz2_stream(&xstate);
		if (xstate.bytes_out < 0)
			bb_error_msg_and_die("inflate error");
	}
#endif
#if ENABLE_FEATURE_UNZIP_LZMA
	else if (zip->fmt.method == 14) {
		/* Not tested yet */
		xstate.bytes_out = unpack_lzma_stream(&xstate);
		if (xstate.bytes_out < 0)
			bb_error_msg_and_die("inflate error");
	}
#endif
#if ENABLE_FEATURE_UNZIP_XZ
	else if (zip->fmt.method == 95) {
		/* Not tested yet */
		xstate.bytes_out = unpack_xz_stream(&xstate);
		if (xstate.bytes_out < 0)
			bb_error_msg_and_die("inflate error");
	}
#endif
	else {
		bb_error_msg_and_die("unsupported method %u", zip->fmt.method);
	}

	/* Validate decompression - size */
	if (zip->fmt.ucmpsize != xstate.bytes_out) {
		/* Don't die. Who knows, maybe len calculation
		 * was botched somewhere. After all, crc matched! */
		bb_error_msg("bad length");
	}
}

static void my_fgets80(char *buf80)
{
	fflush_all();
	if (!fgets(buf80, 80, stdin)) {
		bb_perror_msg_and_die("can't read standard input");
	}
}

static int get_lstat_mode(const char *dst_fn)
{
	struct stat stat_buf;
	if (lstat(dst_fn, &stat_buf) == -1) {
		if (errno != ENOENT) {
			bb_perror_msg_and_die("can't stat '%s'", dst_fn);
		}
		/* File does not exist */
		return -1;
	}
	return stat_buf.st_mode;
}

int unzip_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int unzip_main(int argc, char **argv)
{
	enum {
		OPT_l = (1 << 0),
		OPT_x = (1 << 1),
		OPT_j = (1 << 2),
	};
	unsigned opts;
	smallint quiet = 0;
	IF_NOT_FEATURE_UNZIP_CDF(const) smallint verbose = 0;
	enum { O_PROMPT, O_NEVER, O_ALWAYS };
	smallint overwrite = O_PROMPT;
	uint32_t cdf_offset;
	unsigned long total_usize;
	unsigned long total_size;
	unsigned total_entries;
	int dst_fd = -1;
	char *src_fn = NULL;
	char *dst_fn = NULL;
	llist_t *zaccept = NULL;
	llist_t *zreject = NULL;
	char *base_dir = NULL;
#if ENABLE_FEATURE_UNZIP_CDF
	llist_t *symlink_placeholders = NULL;
#endif
	int i;
	char key_buf[80]; /* must match size used by my_fgets80 */

/* -q, -l and -v: UnZip 5.52 of 28 February 2005, by Info-ZIP:
 *
 * # /usr/bin/unzip -qq -v decompress_unlzma.i.zip
 *   204372  Defl:N    35278  83%  09-06-09 14:23  0d056252  decompress_unlzma.i
 * # /usr/bin/unzip -q -v decompress_unlzma.i.zip
 *  Length   Method    Size  Ratio   Date   Time   CRC-32    Name
 * --------  ------  ------- -----   ----   ----   ------    ----
 *   204372  Defl:N    35278  83%  09-06-09 14:23  0d056252  decompress_unlzma.i
 * --------          -------  ---                            -------
 *   204372            35278  83%                            1 file
 * # /usr/bin/unzip -v decompress_unlzma.i.zip
 * Archive:  decompress_unlzma.i.zip
 *  Length   Method    Size  Ratio   Date   Time   CRC-32    Name
 * --------  ------  ------- -----   ----   ----   ------    ----
 *   204372  Defl:N    35278  83%  09-06-09 14:23  0d056252  decompress_unlzma.i
 * --------          -------  ---                            -------
 *   204372            35278  83%                            1 file
 * # unzip -v decompress_unlzma.i.zip
 * Archive:  decompress_unlzma.i.zip
 *   Length     Date   Time    Name
 *  --------    ----   ----    ----
 *    204372  09-06-09 14:23   decompress_unlzma.i
 *  --------                   -------
 *    204372                   1 files
 * # /usr/bin/unzip -l -qq decompress_unlzma.i.zip
 *    204372  09-06-09 14:23   decompress_unlzma.i
 * # /usr/bin/unzip -l -q decompress_unlzma.i.zip
 *   Length     Date   Time    Name
 *  --------    ----   ----    ----
 *    204372  09-06-09 14:23   decompress_unlzma.i
 *  --------                   -------
 *    204372                   1 file
 * # /usr/bin/unzip -l decompress_unlzma.i.zip
 * Archive:  decompress_unlzma.i.zip
 *   Length     Date   Time    Name
 *  --------    ----   ----    ----
 *    204372  09-06-09 14:23   decompress_unlzma.i
 *  --------                   -------
 *    204372                   1 file
 */

	opts = 0;
	/* '-' makes getopt return 1 for non-options */
	while ((i = getopt(argc, argv, "-d:lnopqxjv")) != -1) {
		switch (i) {
		case 'd':  /* Extract to base directory */
			base_dir = optarg;
			break;

		case 'l': /* List */
			opts |= OPT_l;
			break;

		case 'n': /* Never overwrite existing files */
			overwrite = O_NEVER;
			break;

		case 'o': /* Always overwrite existing files */
			overwrite = O_ALWAYS;
			break;

		case 'p': /* Extract files to stdout and fall through to set verbosity */
			dst_fd = STDOUT_FILENO;

		case 'q': /* Be quiet */
			quiet++;
			break;

		case 'v': /* Verbose list */
			IF_FEATURE_UNZIP_CDF(verbose++;)
			opts |= OPT_l;
			break;

		case 'x':
			opts |= OPT_x;
			break;

		case 'j':
			opts |= OPT_j;
			break;

		case 1:
			if (!src_fn) {
				/* The zip file */
				/* +5: space for ".zip" and NUL */
				src_fn = xmalloc(strlen(optarg) + 5);
				strcpy(src_fn, optarg);
			} else if (!(opts & OPT_x)) {
				/* Include files */
				llist_add_to(&zaccept, optarg);
			} else {
				/* Exclude files */
				llist_add_to(&zreject, optarg);
			}
			break;

		default:
			bb_show_usage();
		}
	}

#ifndef __GLIBC__
	/*
	 * This code is needed for non-GNU getopt
	 * which doesn't understand "-" in option string.
	 * The -x option won't work properly in this case:
	 * "unzip a.zip q -x w e" will be interpreted as
	 * "unzip a.zip q w e -x" = "unzip a.zip q w e"
	 */
	argv += optind;
	if (argv[0]) {
		/* +5: space for ".zip" and NUL */
		src_fn = xmalloc(strlen(argv[0]) + 5);
		strcpy(src_fn, argv[0]);
		while (*++argv)
			llist_add_to(&zaccept, *argv);
	}
#endif

	if (!src_fn) {
		bb_show_usage();
	}

	/* Open input file */
	if (LONE_DASH(src_fn)) {
		xdup2(STDIN_FILENO, zip_fd);
		/* Cannot use prompt mode since zip data is arriving on STDIN */
		if (overwrite == O_PROMPT)
			overwrite = O_NEVER;
	} else {
		static const char extn[][5] ALIGN1 = { ".zip", ".ZIP" };
		char *ext = src_fn + strlen(src_fn);
		int src_fd;

		i = 0;
		for (;;) {
			src_fd = open(src_fn, O_RDONLY);
			if (src_fd >= 0)
				break;
			if (++i > 2) {
				*ext = '\0';
				bb_error_msg_and_die("can't open %s[.zip]", src_fn);
			}
			strcpy(ext, extn[i - 1]);
		}
		xmove_fd(src_fd, zip_fd);
	}

	/* Change dir if necessary */
	if (base_dir)
		xchdir(base_dir);

	if (quiet <= 1) { /* not -qq */
		if (quiet == 0)
			printf("Archive:  %s\n", src_fn);
		if (opts & OPT_l) {
			puts(verbose ?
				" Length   Method    Size  Cmpr    Date    Time   CRC-32   Name\n"
				"--------  ------  ------- ---- ---------- ----- --------  ----"
				:
				"  Length      Date    Time    Name\n"
				"---------  ---------- -----   ----"
				);
		}
	}

/* Example of an archive with one 0-byte long file named 'z'
 * created by Zip 2.31 on Unix:
 * 0000 [50 4b]03 04 0a 00 00 00 00 00 42 1a b8 3c 00 00 |PK........B..<..|
 *       sig........ vneed flags compr mtime mdate crc32>
 * 0010  00 00 00 00 00 00 00 00 00 00 01 00 15 00 7a 55 |..............zU|
 *      >..... csize...... usize...... fnlen exlen fn ex>
 * 0020  54 09 00 03 cc d3 f9 4b cc d3 f9 4b 55 78 04 00 |T......K...KUx..|
 *      >tra_field......................................
 * 0030  00 00 00 00[50 4b]01 02 17 03 0a 00 00 00 00 00 |....PK..........|
 *       ........... sig........ vmade vneed flags compr
 * 0040  42 1a b8 3c 00 00 00 00 00 00 00 00 00 00 00 00 |B..<............|
 *       mtime mdate crc32...... csize...... usize......
 * 0050  01 00 0d 00 00 00 00 00 00 00 00 00 a4 81 00 00 |................|
 *       fnlen exlen clen. dnum. iattr eattr...... relofs> (eattr = rw-r--r--)
 * 0060  00 00 7a 55 54 05 00 03 cc d3 f9 4b 55 78 00 00 |..zUT......KUx..|
 *      >..... fn extra_field...........................
 * 0070 [50 4b]05 06 00 00 00 00 01 00 01 00 3c 00 00 00 |PK..........<...|
 * 0080  34 00 00 00 00 00                               |4.....|
 */
	total_usize = 0;
	total_size = 0;
	total_entries = 0;
	cdf_offset = find_cdf_offset();	/* try to seek to the end, find CDE and CDF start */
	while (1) {
		zip_header_t zip;
		mode_t dir_mode = 0777;
#if ENABLE_FEATURE_UNZIP_CDF
		mode_t file_mode = 0666;
#endif

		if (!ENABLE_FEATURE_UNZIP_CDF || cdf_offset == BAD_CDF_OFFSET) {
			/* Normally happens when input is unseekable.
			 *
			 * Valid ZIP file has Central Directory at the end
			 * with central directory file headers (CDFs).
			 * After it, there is a Central Directory End structure.
			 * CDFs identify what files are in the ZIP and where
			 * they are located. This allows ZIP readers to load
			 * the list of files without reading the entire ZIP archive.
			 * ZIP files may be appended to, only files specified in
			 * the CD are valid. Scanning for local file headers is
			 * not a correct algorithm.
			 *
			 * We try to do the above, and resort to "linear" reading
			 * of ZIP file only if seek failed or CDE wasn't found.
			 */
			uint32_t magic;

			/* Check magic number */
			xread(zip_fd, &magic, 4);
			/* CDF item? Assume there are no more files, exit */
			if (magic == ZIP_CDF_MAGIC) {
				dbg("got ZIP_CDF_MAGIC");
				break;
			}
			/* Data descriptor? It was a streaming file, go on */
			if (magic == ZIP_DD_MAGIC) {
				dbg("got ZIP_DD_MAGIC");
				/* skip over duplicate crc32, cmpsize and ucmpsize */
				unzip_skip(3 * 4);
				continue;
			}
			if (magic != ZIP_FILEHEADER_MAGIC)
				bb_error_msg_and_die("invalid zip magic %08X", (int)magic);
			dbg("got ZIP_FILEHEADER_MAGIC");

			xread(zip_fd, zip.raw, ZIP_HEADER_LEN);
			FIX_ENDIANNESS_ZIP(zip);
			if (zip.fmt.zip_flags & SWAP_LE16(0x0008)) {
				bb_error_msg_and_die("zip flag %s is not supported",
					"8 (streaming)");
			}
		}
#if ENABLE_FEATURE_UNZIP_CDF
		else {
			/* cdf_offset is valid (and we know the file is seekable) */
			cdf_header_t cdf;
			cdf_offset = read_next_cdf(cdf_offset, &cdf);
			if (cdf_offset == 0) /* EOF? */
				break;
# if 1
			xlseek(zip_fd,
				SWAP_LE32(cdf.fmt.relative_offset_of_local_header) + 4,
				SEEK_SET);
			xread(zip_fd, zip.raw, ZIP_HEADER_LEN);
			FIX_ENDIANNESS_ZIP(zip);
			if (zip.fmt.zip_flags & SWAP_LE16(0x0008)) {
				/* 0x0008 - streaming. [u]cmpsize can be reliably gotten
				 * only from Central Directory.
				 */
				zip.fmt.crc32    = cdf.fmt.crc32;
				zip.fmt.cmpsize  = cdf.fmt.cmpsize;
				zip.fmt.ucmpsize = cdf.fmt.ucmpsize;
			}
// Seen in some zipfiles: central directory 9 byte extra field contains
// a subfield with ID 0x5455 and 5 data bytes, which is a Unix-style UTC mtime.
// Local header version:
//  u16 0x5455 ("UT")
//  u16 size (1 + 4 * n)
//  u8  flags: bit 0:mtime is present, bit 1:atime is present, bit 2:ctime is present
//  u32 mtime
//  u32 atime
//  u32 ctime
// Central header version:
//  u16 0x5455 ("UT")
//  u16 size (5 (or 1?))
//  u8  flags: bit 0:mtime is present, bit 1:atime is present, bit 2:ctime is present
//  u32 mtime (CDF does not store atime/ctime)
# else
			/* CDF has the same data as local header, no need to read the latter...
			 * ...not really. An archive was seen with cdf.extra_len == 6 but
			 * zip.extra_len == 0.
			 */
			memcpy(&zip.fmt.version,
				&cdf.fmt.version_needed, ZIP_HEADER_LEN);
			xlseek(zip_fd,
				SWAP_LE32(cdf.fmt.relative_offset_of_local_header) + 4 + ZIP_HEADER_LEN,
				SEEK_SET);
# endif
			if ((cdf.fmt.version_made_by >> 8) == 3) {
				/* This archive is created on Unix */
				dir_mode = file_mode = (cdf.fmt.external_attributes >> 16);
			}
		}
#endif

		if (zip.fmt.zip_flags & SWAP_LE16(0x0001)) {
			/* 0x0001 - encrypted */
			bb_error_msg_and_die("zip flag %s is not supported",
					"1 (encryption)");
		}
		dbg("File cmpsize:0x%x extra_len:0x%x ucmpsize:0x%x",
			(unsigned)zip.fmt.cmpsize,
			(unsigned)zip.fmt.extra_len,
			(unsigned)zip.fmt.ucmpsize
		);

		/* Read filename */
		free(dst_fn);
		die_if_bad_fnamesize(zip.fmt.filename_len);
		dst_fn = xzalloc(zip.fmt.filename_len + 1);
		xread(zip_fd, dst_fn, zip.fmt.filename_len);
		/* Skip extra header bytes */
		unzip_skip(zip.fmt.extra_len);

		/* Guard against "/abspath", "/../" and similar attacks */
		overlapping_strcpy(dst_fn, strip_unsafe_prefix(dst_fn));

		/* Filter zip entries */
		if (find_list_entry(zreject, dst_fn)
		 || (zaccept && !find_list_entry(zaccept, dst_fn))
		) { /* Skip entry */
			goto skip_cmpsize;
		}

		if (opts & OPT_l) {
			/* List entry */
			char dtbuf[sizeof("mm-dd-yyyy hh:mm")];
			sprintf(dtbuf, "%02u-%02u-%04u %02u:%02u",
				(zip.fmt.moddate >> 5) & 0xf,  // mm: 0x01e0
				(zip.fmt.moddate)      & 0x1f, // dd: 0x001f
				(zip.fmt.moddate >> 9) + 1980, // yy: 0xfe00
				(zip.fmt.modtime >> 11),       // hh: 0xf800
				(zip.fmt.modtime >> 5) & 0x3f  // mm: 0x07e0
				// seconds/2 not shown, encoded in -- 0x001f
			);
			if (!verbose) {
				//      "  Length      Date    Time    Name\n"
				//      "---------  ---------- -----   ----"
				printf(       "%9u  " "%s   "         "%s\n",
					(unsigned)zip.fmt.ucmpsize,
					dtbuf,
					dst_fn);
			} else {
				char method6[7];
				unsigned long percents;

				sprintf(method6, "%6u", zip.fmt.method);
				if (zip.fmt.method == 0) {
					strcpy(method6, "Stored");
				}
				if (zip.fmt.method == 8) {
					strcpy(method6, "Defl:N");
					/* normal, maximum, fast, superfast */
					IF_DESKTOP(method6[5] = "NXFS"[(zip.fmt.zip_flags >> 1) & 3];)
				}
				percents = zip.fmt.ucmpsize - zip.fmt.cmpsize;
				if ((int32_t)percents < 0)
					percents = 0; /* happens if ucmpsize < cmpsize */
				percents = percents * 100;
				if (zip.fmt.ucmpsize)
					percents /= zip.fmt.ucmpsize;
				//      " Length   Method    Size  Cmpr    Date    Time   CRC-32   Name\n"
				//      "--------  ------  ------- ---- ---------- ----- --------  ----"
				printf(      "%8u  %s"        "%9u%4u%% " "%s "         "%08x  "  "%s\n",
					(unsigned)zip.fmt.ucmpsize,
					method6,
					(unsigned)zip.fmt.cmpsize,
					(unsigned)percents,
					dtbuf,
					zip.fmt.crc32,
					dst_fn);
				total_size += zip.fmt.cmpsize;
			}
			total_usize += zip.fmt.ucmpsize;
			goto skip_cmpsize;
		}

		if (dst_fd == STDOUT_FILENO) {
			/* Extracting to STDOUT */
			goto do_extract;
		}

		/* Strip paths (after -l: unzip -lj a.zip lists full names) */
		if (opts & OPT_j)
			overlapping_strcpy(dst_fn, bb_basename(dst_fn));
		/* Did this strip everything ("DIR/" case)? Then skip */
		if (!dst_fn[0])
			goto skip_cmpsize;

		if (last_char_is(dst_fn, '/')) {
			int mode;

			/* Extract directory */
			mode = get_lstat_mode(dst_fn);
			if (mode == -1) { /* ENOENT */
				if (!quiet) {
					printf("   creating: %s\n", dst_fn);
				}
				unzip_create_leading_dirs(dst_fn);
				if (bb_make_directory(dst_fn, dir_mode, FILEUTILS_IGNORE_CHMOD_ERR)) {
					xfunc_die();
				}
			} else {
				if (!S_ISDIR(mode)) {
					bb_error_msg_and_die("'%s' exists but is not a %s",
						dst_fn, "directory");
				}
			}
			goto skip_cmpsize;
		}
 check_file:
		/* Does target file already exist? */
		{
			int mode = get_lstat_mode(dst_fn);
			if (mode == -1) {
				/* ENOENT: does not exist */
				goto do_open_and_extract;
			}
			if (overwrite == O_NEVER) {
				goto skip_cmpsize;
			}
			if (!S_ISREG(mode)) {
 fishy:
				bb_error_msg_and_die("'%s' exists but is not a %s",
					dst_fn, "regular file");
			}
			if (overwrite == O_ALWAYS) {
				goto do_open_and_extract;
			}
			printf("replace %s? [y]es, [n]o, [A]ll, [N]one, [r]ename: ", dst_fn);
			my_fgets80(key_buf);
			/* User input could take a long time. Is it still a regular file? */
			mode = get_lstat_mode(dst_fn);
			if (!S_ISREG(mode))
				goto fishy;
		}

		/* Extract (or skip) it */
		switch (key_buf[0]) {
		case 'A':
			overwrite = O_ALWAYS;
		case 'y': /* Open file and fall into unzip */
 do_open_and_extract:
			unzip_create_leading_dirs(dst_fn);
#if ENABLE_FEATURE_UNZIP_CDF
			dst_fd = -1;
			if (!S_ISLNK(file_mode)) {
				dst_fd = xopen3(dst_fn,
					O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW,
					file_mode);
			}
#else
			/* O_NOFOLLOW defends against symlink attacks */
			dst_fd = xopen(dst_fn, O_WRONLY | O_CREAT | O_TRUNC | O_NOFOLLOW);
#endif
 do_extract:
			if (!quiet) {
				printf(/* zip.fmt.method == 0
					? " extracting: %s\n"
					: */ "  inflating: %s\n", dst_fn);
			}
#if ENABLE_FEATURE_UNZIP_CDF
			if (S_ISLNK(file_mode)) {
				if (dst_fd != STDOUT_FILENO) /* not -p? */
					unzip_extract_symlink(&symlink_placeholders, &zip, dst_fn);
			} else
#endif
			{
				unzip_extract(&zip, dst_fd);
				if (dst_fd != STDOUT_FILENO) {
					/* closing STDOUT is potentially bad for future business */
					close(dst_fd);
				}
			}
			break;

		case 'N':
			overwrite = O_NEVER;
		case 'n': /* Skip entry data */
 skip_cmpsize:
			unzip_skip(zip.fmt.cmpsize);
			break;

		case 'r':
			/* Prompt for new name */
			printf("new name: ");
			my_fgets80(key_buf);
			free(dst_fn);
			dst_fn = xstrdup(key_buf);
			chomp(dst_fn);
			goto check_file;

		default:
			printf("error: invalid response [%c]\n", (char)key_buf[0]);
			goto check_file;
		}

		total_entries++;
	}

#if ENABLE_FEATURE_UNZIP_CDF
	create_symlinks_from_list(symlink_placeholders);
#endif

	if ((opts & OPT_l) && quiet <= 1) {
		if (!verbose) {
			//	"  Length      Date    Time    Name\n"
			//	"---------  ---------- -----   ----"
			printf( " --------%21s"               "-------\n"
				     "%9lu%21s"               "%u files\n",
				"",
				total_usize, "", total_entries);
		} else {
			unsigned long percents = total_usize - total_size;
			if ((long)percents < 0)
				percents = 0; /* happens if usize < size */
			percents = percents * 100;
			if (total_usize)
				percents /= total_usize;
			//	" Length   Method    Size  Cmpr    Date    Time   CRC-32   Name\n"
			//	"--------  ------  ------- ---- ---------- ----- --------  ----"
			printf( "--------          ------- ----%28s"                      "----\n"
				"%8lu"              "%17lu%4u%%%28s"                      "%u files\n",
				"",
				total_usize, total_size, (unsigned)percents, "",
				total_entries);
		}
	}

	return 0;
}