summaryrefslogtreecommitdiffstats
path: root/contrib/libarchive/libarchive/archive_read_open_filename.c
blob: 64b0179762092ef3bd42597260e02e5876dfe628 (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
/*-
 * Copyright (c) 2003-2010 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.
 */

#include "archive_platform.h"
__FBSDID("$FreeBSD$");

#ifdef HAVE_SYS_IOCTL_H
#include <sys/ioctl.h>
#endif
#ifdef HAVE_SYS_STAT_H
#include <sys/stat.h>
#endif
#ifdef HAVE_ERRNO_H
#include <errno.h>
#endif
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
#ifdef HAVE_IO_H
#include <io.h>
#endif
#ifdef HAVE_STDLIB_H
#include <stdlib.h>
#endif
#ifdef HAVE_STRING_H
#include <string.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
#include <sys/disk.h>
#elif defined(__NetBSD__) || defined(__OpenBSD__)
#include <sys/disklabel.h>
#include <sys/dkio.h>
#elif defined(__DragonFly__)
#include <sys/diskslice.h>
#endif

#include "archive.h"
#include "archive_private.h"
#include "archive_string.h"

#ifndef O_BINARY
#define O_BINARY 0
#endif
#ifndef O_CLOEXEC
#define O_CLOEXEC	0
#endif

struct read_file_data {
	int	 fd;
	size_t	 block_size;
	void	*buffer;
	mode_t	 st_mode;  /* Mode bits for opened file. */
	char	 use_lseek;
	enum fnt_e { FNT_STDIN, FNT_MBS, FNT_WCS } filename_type;
	union {
		char	 m[1];/* MBS filename. */
		wchar_t	 w[1];/* WCS filename. */
	} filename; /* Must be last! */
};

static int	file_open(struct archive *, void *);
static int	file_close(struct archive *, void *);
static int file_close2(struct archive *, void *);
static int file_switch(struct archive *, void *, void *);
static ssize_t	file_read(struct archive *, void *, const void **buff);
static int64_t	file_seek(struct archive *, void *, int64_t request, int);
static int64_t	file_skip(struct archive *, void *, int64_t request);
static int64_t	file_skip_lseek(struct archive *, void *, int64_t request);

int
archive_read_open_file(struct archive *a, const char *filename,
    size_t block_size)
{
	return (archive_read_open_filename(a, filename, block_size));
}

int
archive_read_open_filename(struct archive *a, const char *filename,
    size_t block_size)
{
	const char *filenames[2];
	filenames[0] = filename;
	filenames[1] = NULL;
	return archive_read_open_filenames(a, filenames, block_size);
}

int
archive_read_open_filenames(struct archive *a, const char **filenames,
    size_t block_size)
{
	struct read_file_data *mine;
	const char *filename = NULL;
	if (filenames)
		filename = *(filenames++);

	archive_clear_error(a);
	do
	{
		if (filename == NULL)
			filename = "";
		mine = (struct read_file_data *)calloc(1,
			sizeof(*mine) + strlen(filename));
		if (mine == NULL)
			goto no_memory;
		strcpy(mine->filename.m, filename);
		mine->block_size = block_size;
		mine->fd = -1;
		mine->buffer = NULL;
		mine->st_mode = mine->use_lseek = 0;
		if (filename == NULL || filename[0] == '\0') {
			mine->filename_type = FNT_STDIN;
		} else
			mine->filename_type = FNT_MBS;
		if (archive_read_append_callback_data(a, mine) != (ARCHIVE_OK))
			return (ARCHIVE_FATAL);
		if (filenames == NULL)
			break;
		filename = *(filenames++);
	} while (filename != NULL && filename[0] != '\0');
	archive_read_set_open_callback(a, file_open);
	archive_read_set_read_callback(a, file_read);
	archive_read_set_skip_callback(a, file_skip);
	archive_read_set_close_callback(a, file_close);
	archive_read_set_switch_callback(a, file_switch);
	archive_read_set_seek_callback(a, file_seek);

	return (archive_read_open1(a));
no_memory:
	archive_set_error(a, ENOMEM, "No memory");
	return (ARCHIVE_FATAL);
}

int
archive_read_open_filename_w(struct archive *a, const wchar_t *wfilename,
    size_t block_size)
{
	struct read_file_data *mine = (struct read_file_data *)calloc(1,
		sizeof(*mine) + wcslen(wfilename) * sizeof(wchar_t));
	if (!mine)
	{
		archive_set_error(a, ENOMEM, "No memory");
		return (ARCHIVE_FATAL);
	}
	mine->fd = -1;
	mine->block_size = block_size;

	if (wfilename == NULL || wfilename[0] == L'\0') {
		mine->filename_type = FNT_STDIN;
	} else {
#if defined(_WIN32) && !defined(__CYGWIN__)
		mine->filename_type = FNT_WCS;
		wcscpy(mine->filename.w, wfilename);
#else
		/*
		 * POSIX system does not support a wchar_t interface for
		 * open() system call, so we have to translate a wchar_t
		 * filename to multi-byte one and use it.
		 */
		struct archive_string fn;

		archive_string_init(&fn);
		if (archive_string_append_from_wcs(&fn, wfilename,
		    wcslen(wfilename)) != 0) {
			if (errno == ENOMEM)
				archive_set_error(a, errno,
				    "Can't allocate memory");
			else
				archive_set_error(a, EINVAL,
				    "Failed to convert a wide-character"
				    " filename to a multi-byte filename");
			archive_string_free(&fn);
			free(mine);
			return (ARCHIVE_FATAL);
		}
		mine->filename_type = FNT_MBS;
		strcpy(mine->filename.m, fn.s);
		archive_string_free(&fn);
#endif
	}
	if (archive_read_append_callback_data(a, mine) != (ARCHIVE_OK))
		return (ARCHIVE_FATAL);
	archive_read_set_open_callback(a, file_open);
	archive_read_set_read_callback(a, file_read);
	archive_read_set_skip_callback(a, file_skip);
	archive_read_set_close_callback(a, file_close);
	archive_read_set_switch_callback(a, file_switch);
	archive_read_set_seek_callback(a, file_seek);

	return (archive_read_open1(a));
}

static int
file_open(struct archive *a, void *client_data)
{
	struct stat st;
	struct read_file_data *mine = (struct read_file_data *)client_data;
	void *buffer;
	const char *filename = NULL;
	const wchar_t *wfilename = NULL;
	int fd = -1;
	int is_disk_like = 0;
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	off_t mediasize = 0; /* FreeBSD-specific, so off_t okay here. */
#elif defined(__NetBSD__) || defined(__OpenBSD__)
	struct disklabel dl;
#elif defined(__DragonFly__)
	struct partinfo pi;
#endif

	archive_clear_error(a);
	if (mine->filename_type == FNT_STDIN) {
		/* We used to delegate stdin support by
		 * directly calling archive_read_open_fd(a,0,block_size)
		 * here, but that doesn't (and shouldn't) handle the
		 * end-of-file flush when reading stdout from a pipe.
		 * Basically, read_open_fd() is intended for folks who
		 * are willing to handle such details themselves.  This
		 * API is intended to be a little smarter for folks who
		 * want easy handling of the common case.
		 */
		fd = 0;
#if defined(__CYGWIN__) || defined(_WIN32)
		setmode(0, O_BINARY);
#endif
		filename = "";
	} else if (mine->filename_type == FNT_MBS) {
		filename = mine->filename.m;
		fd = open(filename, O_RDONLY | O_BINARY | O_CLOEXEC);
		__archive_ensure_cloexec_flag(fd);
		if (fd < 0) {
			archive_set_error(a, errno,
			    "Failed to open '%s'", filename);
			return (ARCHIVE_FATAL);
		}
	} else {
#if defined(_WIN32) && !defined(__CYGWIN__)
		wfilename = mine->filename.w;
		fd = _wopen(wfilename, O_RDONLY | O_BINARY);
		if (fd < 0 && errno == ENOENT) {
			wchar_t *fullpath;
			fullpath = __la_win_permissive_name_w(wfilename);
			if (fullpath != NULL) {
				fd = _wopen(fullpath, O_RDONLY | O_BINARY);
				free(fullpath);
			}
		}
		if (fd < 0) {
			archive_set_error(a, errno,
			    "Failed to open '%S'", wfilename);
			return (ARCHIVE_FATAL);
		}
#else
		archive_set_error(a, ARCHIVE_ERRNO_MISC,
		    "Unexpedted operation in archive_read_open_filename");
		goto fail;
#endif
	}
	if (fstat(fd, &st) != 0) {
		if (mine->filename_type == FNT_WCS)
			archive_set_error(a, errno, "Can't stat '%S'",
			    wfilename);
		else
			archive_set_error(a, errno, "Can't stat '%s'",
			    filename);
		goto fail;
	}

	/*
	 * Determine whether the input looks like a disk device or a
	 * tape device.  The results are used below to select an I/O
	 * strategy:
	 *  = "disk-like" devices support arbitrary lseek() and will
	 *    support I/O requests of any size.  So we get easy skipping
	 *    and can cheat on block sizes to get better performance.
	 *  = "tape-like" devices require strict blocking and use
	 *    specialized ioctls for seeking.
	 *  = "socket-like" devices cannot seek at all but can improve
	 *    performance by using nonblocking I/O to read "whatever is
	 *    available right now".
	 *
	 * Right now, we only specially recognize disk-like devices,
	 * but it should be straightforward to add probes and strategy
	 * here for tape-like and socket-like devices.
	 */
	if (S_ISREG(st.st_mode)) {
		/* Safety:  Tell the extractor not to overwrite the input. */
		archive_read_extract_set_skip_file(a, st.st_dev, st.st_ino);
		/* Regular files act like disks. */
		is_disk_like = 1;
	}
#if defined(__FreeBSD__) || defined(__FreeBSD_kernel__)
	/* FreeBSD: if it supports DIOCGMEDIASIZE ioctl, it's disk-like. */
	else if (S_ISCHR(st.st_mode) &&
	    ioctl(fd, DIOCGMEDIASIZE, &mediasize) == 0 &&
	    mediasize > 0) {
		is_disk_like = 1;
	}
#elif defined(__NetBSD__) || defined(__OpenBSD__)
	/* Net/OpenBSD: if it supports DIOCGDINFO ioctl, it's disk-like. */
	else if ((S_ISCHR(st.st_mode) || S_ISBLK(st.st_mode)) &&
	    ioctl(fd, DIOCGDINFO, &dl) == 0 &&
	    dl.d_partitions[DISKPART(st.st_rdev)].p_size > 0) {
		is_disk_like = 1;
	}
#elif defined(__DragonFly__)
	/* DragonFly BSD:  if it supports DIOCGPART ioctl, it's disk-like. */
	else if (S_ISCHR(st.st_mode) &&
	    ioctl(fd, DIOCGPART, &pi) == 0 &&
	    pi.media_size > 0) {
		is_disk_like = 1;
	}
#elif defined(__linux__)
	/* Linux:  All block devices are disk-like. */
	else if (S_ISBLK(st.st_mode) &&
	    lseek(fd, 0, SEEK_CUR) == 0 &&
	    lseek(fd, 0, SEEK_SET) == 0 &&
	    lseek(fd, 0, SEEK_END) > 0 &&
	    lseek(fd, 0, SEEK_SET) == 0) {
		is_disk_like = 1;
	}
#endif
	/* TODO: Add an "is_tape_like" variable and appropriate tests. */

	/* Disk-like devices prefer power-of-two block sizes.  */
	/* Use provided block_size as a guide so users have some control. */
	if (is_disk_like) {
		size_t new_block_size = 64 * 1024;
		while (new_block_size < mine->block_size
		    && new_block_size < 64 * 1024 * 1024)
			new_block_size *= 2;
		mine->block_size = new_block_size;
	}
	buffer = malloc(mine->block_size);
	if (buffer == NULL) {
		archive_set_error(a, ENOMEM, "No memory");
		goto fail;
	}
	mine->buffer = buffer;
	mine->fd = fd;
	/* Remember mode so close can decide whether to flush. */
	mine->st_mode = st.st_mode;

	/* Disk-like inputs can use lseek(). */
	if (is_disk_like)
		mine->use_lseek = 1;

	return (ARCHIVE_OK);
fail:
	/*
	 * Don't close file descriptors not opened or ones pointing referring
	 * to `FNT_STDIN`.
	 */
	if (fd != -1 && fd != 0)
		close(fd);
	return (ARCHIVE_FATAL);
}

static ssize_t
file_read(struct archive *a, void *client_data, const void **buff)
{
	struct read_file_data *mine = (struct read_file_data *)client_data;
	ssize_t bytes_read;

	/* TODO: If a recent lseek() operation has left us
	 * mis-aligned, read and return a short block to try to get
	 * us back in alignment. */

	/* TODO: Someday, try mmap() here; if that succeeds, give
	 * the entire file to libarchive as a single block.  That
	 * could be a lot faster than block-by-block manual I/O. */

	/* TODO: We might be able to improve performance on pipes and
	 * sockets by setting non-blocking I/O and just accepting
	 * whatever we get here instead of waiting for a full block
	 * worth of data. */

	*buff = mine->buffer;
	for (;;) {
		bytes_read = read(mine->fd, mine->buffer, mine->block_size);
		if (bytes_read < 0) {
			if (errno == EINTR)
				continue;
			else if (mine->filename_type == FNT_STDIN)
				archive_set_error(a, errno,
				    "Error reading stdin");
			else if (mine->filename_type == FNT_MBS)
				archive_set_error(a, errno,
				    "Error reading '%s'", mine->filename.m);
			else
				archive_set_error(a, errno,
				    "Error reading '%S'", mine->filename.w);
		}
		return (bytes_read);
	}
}

/*
 * Regular files and disk-like block devices can use simple lseek
 * without needing to round the request to the block size.
 *
 * TODO: This can leave future reads mis-aligned.  Since we know the
 * offset here, we should store it and use it in file_read() above
 * to determine whether we should perform a short read to get back
 * into alignment.  Long series of mis-aligned reads can negatively
 * impact disk throughput.  (Of course, the performance impact should
 * be carefully tested; extra code complexity is only worthwhile if
 * it does provide measurable improvement.)
 *
 * TODO: Be lazy about the actual seek.  There are a few pathological
 * cases where libarchive makes a bunch of seek requests in a row
 * without any intervening reads.  This isn't a huge performance
 * problem, since the kernel handles seeks lazily already, but
 * it would be very slightly faster if we simply remembered the
 * seek request here and then actually performed the seek at the
 * top of the read callback above.
 */
static int64_t
file_skip_lseek(struct archive *a, void *client_data, int64_t request)
{
	struct read_file_data *mine = (struct read_file_data *)client_data;
#if defined(_WIN32) && !defined(__CYGWIN__)
	/* We use _lseeki64() on Windows. */
	int64_t old_offset, new_offset;
#else
	off_t old_offset, new_offset;
#endif

	/* We use off_t here because lseek() is declared that way. */

	/* TODO: Deal with case where off_t isn't 64 bits.
	 * This shouldn't be a problem on Linux or other POSIX
	 * systems, since the configuration logic for libarchive
	 * tries to obtain a 64-bit off_t.
	 */
	if ((old_offset = lseek(mine->fd, 0, SEEK_CUR)) >= 0 &&
	    (new_offset = lseek(mine->fd, request, SEEK_CUR)) >= 0)
		return (new_offset - old_offset);

	/* If lseek() fails, don't bother trying again. */
	mine->use_lseek = 0;

	/* Let libarchive recover with read+discard */
	if (errno == ESPIPE)
		return (0);

	/* If the input is corrupted or truncated, fail. */
	if (mine->filename_type == FNT_STDIN)
		archive_set_error(a, errno, "Error seeking in stdin");
	else if (mine->filename_type == FNT_MBS)
		archive_set_error(a, errno, "Error seeking in '%s'",
		    mine->filename.m);
	else
		archive_set_error(a, errno, "Error seeking in '%S'",
		    mine->filename.w);
	return (-1);
}


/*
 * TODO: Implement another file_skip_XXXX that uses MTIO ioctls to
 * accelerate operation on tape drives.
 */

static int64_t
file_skip(struct archive *a, void *client_data, int64_t request)
{
	struct read_file_data *mine = (struct read_file_data *)client_data;

	/* Delegate skip requests. */
	if (mine->use_lseek)
		return (file_skip_lseek(a, client_data, request));

	/* If we can't skip, return 0; libarchive will read+discard instead. */
	return (0);
}

/*
 * TODO: Store the offset and use it in the read callback.
 */
static int64_t
file_seek(struct archive *a, void *client_data, int64_t request, int whence)
{
	struct read_file_data *mine = (struct read_file_data *)client_data;
	int64_t r;

	/* We use off_t here because lseek() is declared that way. */
	/* See above for notes about when off_t is less than 64 bits. */
	r = lseek(mine->fd, request, whence);
	if (r >= 0)
		return r;

	/* If the input is corrupted or truncated, fail. */
	if (mine->filename_type == FNT_STDIN)
		archive_set_error(a, errno, "Error seeking in stdin");
	else if (mine->filename_type == FNT_MBS)
		archive_set_error(a, errno, "Error seeking in '%s'",
		    mine->filename.m);
	else
		archive_set_error(a, errno, "Error seeking in '%S'",
		    mine->filename.w);
	return (ARCHIVE_FATAL);
}

static int
file_close2(struct archive *a, void *client_data)
{
	struct read_file_data *mine = (struct read_file_data *)client_data;

	(void)a; /* UNUSED */

	/* Only flush and close if open succeeded. */
	if (mine->fd >= 0) {
		/*
		 * Sometimes, we should flush the input before closing.
		 *   Regular files: faster to just close without flush.
		 *   Disk-like devices:  Ditto.
		 *   Tapes: must not flush (user might need to
		 *      read the "next" item on a non-rewind device).
		 *   Pipes and sockets:  must flush (otherwise, the
		 *      program feeding the pipe or socket may complain).
		 * Here, I flush everything except for regular files and
		 * device nodes.
		 */
		if (!S_ISREG(mine->st_mode)
		    && !S_ISCHR(mine->st_mode)
		    && !S_ISBLK(mine->st_mode)) {
			ssize_t bytesRead;
			do {
				bytesRead = read(mine->fd, mine->buffer,
				    mine->block_size);
			} while (bytesRead > 0);
		}
		/* If a named file was opened, then it needs to be closed. */
		if (mine->filename_type != FNT_STDIN)
			close(mine->fd);
	}
	free(mine->buffer);
	mine->buffer = NULL;
	mine->fd = -1;
	return (ARCHIVE_OK);
}

static int
file_close(struct archive *a, void *client_data)
{
	struct read_file_data *mine = (struct read_file_data *)client_data;
	file_close2(a, client_data);
	free(mine);
	return (ARCHIVE_OK);
}

static int
file_switch(struct archive *a, void *client_data1, void *client_data2)
{
	file_close2(a, client_data1);
	return file_open(a, client_data2);
}
OpenPOWER on IntegriCloud