GCC Code Coverage Report
Directory: ./ Exec Total Coverage
File: bin/pax/tables.c Lines: 102 499 20.4 %
Date: 2017-11-13 Branches: 49 378 13.0 %

Line Branch Exec Source
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/*	$OpenBSD: tables.c,v 1.53 2017/09/16 07:42:34 otto Exp $	*/
2
/*	$NetBSD: tables.c,v 1.4 1995/03/21 09:07:45 cgd Exp $	*/
3
4
/*-
5
 * Copyright (c) 1992 Keith Muller.
6
 * Copyright (c) 1992, 1993
7
 *	The Regents of the University of California.  All rights reserved.
8
 *
9
 * This code is derived from software contributed to Berkeley by
10
 * Keith Muller of the University of California, San Diego.
11
 *
12
 * Redistribution and use in source and binary forms, with or without
13
 * modification, are permitted provided that the following conditions
14
 * are met:
15
 * 1. Redistributions of source code must retain the above copyright
16
 *    notice, this list of conditions and the following disclaimer.
17
 * 2. Redistributions in binary form must reproduce the above copyright
18
 *    notice, this list of conditions and the following disclaimer in the
19
 *    documentation and/or other materials provided with the distribution.
20
 * 3. Neither the name of the University nor the names of its contributors
21
 *    may be used to endorse or promote products derived from this software
22
 *    without specific prior written permission.
23
 *
24
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34
 * SUCH DAMAGE.
35
 */
36
37
#include <sys/types.h>
38
#include <sys/stat.h>
39
#include <errno.h>
40
#include <fcntl.h>
41
#include <limits.h>
42
#include <signal.h>
43
#include <stdio.h>
44
#include <stdlib.h>
45
#include <string.h>
46
#include <unistd.h>
47
48
#include "pax.h"
49
#include "extern.h"
50
51
/*
52
 * Routines for controlling the contents of all the different databases pax
53
 * keeps. Tables are dynamically created only when they are needed. The
54
 * goal was speed and the ability to work with HUGE archives. The databases
55
 * were kept simple, but do have complex rules for when the contents change.
56
 * As of this writing, the posix library functions were more complex than
57
 * needed for this application (pax databases have very short lifetimes and
58
 * do not survive after pax is finished). Pax is required to handle very
59
 * large archives. These database routines carefully combine memory usage and
60
 * temporary file storage in ways which will not significantly impact runtime
61
 * performance while allowing the largest possible archives to be handled.
62
 * Trying to force the fit to the posix database routines was not considered
63
 * time well spent.
64
 */
65
66
/*
67
 * data structures and constants used by the different databases kept by pax
68
 */
69
70
/*
71
 * Hash Table Sizes MUST BE PRIME, if set too small performance suffers.
72
 * Probably safe to expect 500000 inodes per tape. Assuming good key
73
 * distribution (inodes) chains of under 50 long (worst case) is ok.
74
 */
75
#define L_TAB_SZ	2503		/* hard link hash table size */
76
#define F_TAB_SZ	50503		/* file time hash table size */
77
#define N_TAB_SZ	541		/* interactive rename hash table */
78
#define D_TAB_SZ	317		/* unique device mapping table */
79
#define A_TAB_SZ	317		/* ftree dir access time reset table */
80
#define SL_TAB_SZ	317		/* escape symlink tables */
81
#define MAXKEYLEN	64		/* max number of chars for hash */
82
#define DIRP_SIZE	64		/* initial size of created dir table */
83
84
/*
85
 * file hard link structure (hashed by dev/ino and chained) used to find the
86
 * hard links in a file system or with some archive formats (cpio)
87
 */
88
typedef struct hrdlnk {
89
	ino_t		ino;	/* files inode number */
90
	char		*name;	/* name of first file seen with this ino/dev */
91
	dev_t		dev;	/* files device number */
92
	u_long		nlink;	/* expected link count */
93
	struct hrdlnk	*fow;
94
} HRDLNK;
95
96
/*
97
 * Archive write update file time table (the -u, -C flag), hashed by filename.
98
 * Filenames are stored in a scratch file at seek offset into the file. The
99
 * file time (mod time) and the file name length (for a quick check) are
100
 * stored in a hash table node. We were forced to use a scratch file because
101
 * with -u, the mtime for every node in the archive must always be available
102
 * to compare against (and this data can get REALLY large with big archives).
103
 * By being careful to read only when we have a good chance of a match, the
104
 * performance loss is not measurable (and the size of the archive we can
105
 * handle is greatly increased).
106
 */
107
typedef struct ftm {
108
	off_t		seek;		/* location in scratch file */
109
	struct timespec	mtim;		/* files last modification time */
110
	struct ftm	*fow;
111
	int		namelen;	/* file name length */
112
} FTM;
113
114
/*
115
 * Interactive rename table (-i flag), hashed by orig filename.
116
 * We assume this will not be a large table as this mapping data can only be
117
 * obtained through interactive input by the user. Nobody is going to type in
118
 * changes for 500000 files? We use chaining to resolve collisions.
119
 */
120
121
typedef struct namt {
122
	char		*oname;		/* old name */
123
	char		*nname;		/* new name typed in by the user */
124
	struct namt	*fow;
125
} NAMT;
126
127
/*
128
 * Unique device mapping tables. Some protocols (e.g. cpio) require that the
129
 * <c_dev,c_ino> pair will uniquely identify a file in an archive unless they
130
 * are links to the same file. Appending to archives can break this. For those
131
 * protocols that have this requirement we map c_dev to a unique value not seen
132
 * in the archive when we append. We also try to handle inode truncation with
133
 * this table. (When the inode field in the archive header are too small, we
134
 * remap the dev on writes to remove accidental collisions).
135
 *
136
 * The list is hashed by device number using chain collision resolution. Off of
137
 * each DEVT are linked the various remaps for this device based on those bits
138
 * in the inode which were truncated. For example if we are just remapping to
139
 * avoid a device number during an update append, off the DEVT we would have
140
 * only a single DLIST that has a truncation id of 0 (no inode bits were
141
 * stripped for this device so far). When we spot inode truncation we create
142
 * a new mapping based on the set of bits in the inode which were stripped off.
143
 * so if the top four bits of the inode are stripped and they have a pattern of
144
 * 0110...... (where . are those bits not truncated) we would have a mapping
145
 * assigned for all inodes that has the same 0110.... pattern (with this dev
146
 * number of course). This keeps the mapping sparse and should be able to store
147
 * close to the limit of files which can be represented by the optimal
148
 * combination of dev and inode bits, and without creating a fouled up archive.
149
 * Note we also remap truncated devs in the same way (an exercise for the
150
 * dedicated reader; always wanted to say that...:)
151
 */
152
153
typedef struct devt {
154
	dev_t		dev;	/* the orig device number we now have to map */
155
	struct devt	*fow;	/* new device map list */
156
	struct dlist	*list;	/* map list based on inode truncation bits */
157
} DEVT;
158
159
typedef struct dlist {
160
	ino_t trunc_bits;	/* truncation pattern for a specific map */
161
	dev_t dev;		/* the new device id we use */
162
	struct dlist *fow;
163
} DLIST;
164
165
/*
166
 * ftree directory access time reset table. When we are done with a
167
 * subtree we reset the access and mod time of the directory when the tflag is
168
 * set. Not really explicitly specified in the pax spec, but easy and fast to
169
 * do (and this may have even been intended in the spec, it is not clear).
170
 * table is hashed by inode with chaining.
171
 */
172
173
typedef struct atdir {
174
	struct file_times ft;
175
	struct atdir *fow;
176
} ATDIR;
177
178
/*
179
 * created directory time and mode storage entry. After pax is finished during
180
 * extraction or copy, we must reset directory access modes and times that
181
 * may have been modified after creation (they no longer have the specified
182
 * times and/or modes). We must reset time in the reverse order of creation,
183
 * because entries are added  from the top of the file tree to the bottom.
184
 * We MUST reset times from leaf to root (it will not work the other
185
 * direction).
186
 */
187
188
typedef struct dirdata {
189
	struct file_times ft;
190
	u_int16_t mode;		/* file mode to restore */
191
	u_int16_t frc_mode;	/* do we force mode settings? */
192
} DIRDATA;
193
194
static HRDLNK **ltab = NULL;	/* hard link table for detecting hard links */
195
static FTM **ftab = NULL;	/* file time table for updating arch */
196
static NAMT **ntab = NULL;	/* interactive rename storage table */
197
#ifndef NOCPIO
198
static DEVT **dtab = NULL;	/* device/inode mapping tables */
199
#endif
200
static ATDIR **atab = NULL;	/* file tree directory time reset table */
201
static DIRDATA *dirp = NULL;	/* storage for setting created dir time/mode */
202
static size_t dirsize;		/* size of dirp table */
203
static size_t dircnt = 0;	/* entries in dir time/mode storage */
204
static int ffd = -1;		/* tmp file for file time table name storage */
205
206
/*
207
 * hard link table routines
208
 *
209
 * The hard link table tries to detect hard links to files using the device and
210
 * inode values. We do this when writing an archive, so we can tell the format
211
 * write routine that this file is a hard link to another file. The format
212
 * write routine then can store this file in whatever way it wants (as a hard
213
 * link if the format supports that like tar, or ignore this info like cpio).
214
 * (Actually a field in the format driver table tells us if the format wants
215
 * hard link info. if not, we do not waste time looking for them). We also use
216
 * the same table when reading an archive. In that situation, this table is
217
 * used by the format read routine to detect hard links from stored dev and
218
 * inode numbers (like cpio). This will allow pax to create a link when one
219
 * can be detected by the archive format.
220
 */
221
222
/*
223
 * lnk_start
224
 *	Creates the hard link table.
225
 * Return:
226
 *	0 if created, -1 if failure
227
 */
228
229
int
230
lnk_start(void)
231
{
232
68
	if (ltab != NULL)
233
		return(0);
234
34
	if ((ltab = calloc(L_TAB_SZ, sizeof(HRDLNK *))) == NULL) {
235
		paxwarn(1, "Cannot allocate memory for hard link table");
236
		return(-1);
237
	}
238
34
	return(0);
239
34
}
240
241
/*
242
 * chk_lnk()
243
 *	Looks up entry in hard link hash table. If found, it copies the name
244
 *	of the file it is linked to (we already saw that file) into ln_name.
245
 *	lnkcnt is decremented and if goes to 1 the node is deleted from the
246
 *	database. (We have seen all the links to this file). If not found,
247
 *	we add the file to the database if it has the potential for having
248
 *	hard links to other files we may process (it has a link count > 1)
249
 * Return:
250
 *	if found returns 1; if not found returns 0; -1 on error
251
 */
252
253
int
254
chk_lnk(ARCHD *arcn)
255
{
256
	HRDLNK *pt;
257
	HRDLNK **ppt;
258
	u_int indx;
259
260
226
	if (ltab == NULL)
261
		return(-1);
262
	/*
263
	 * ignore those nodes that cannot have hard links
264
	 */
265

210
	if ((arcn->type == PAX_DIR) || (arcn->sb.st_nlink <= 1))
266
89
		return(0);
267
268
	/*
269
	 * hash inode number and look for this file
270
	 */
271
24
	indx = ((unsigned)arcn->sb.st_ino) % L_TAB_SZ;
272
24
	if ((pt = ltab[indx]) != NULL) {
273
		/*
274
		 * its hash chain in not empty, walk down looking for it
275
		 */
276
		ppt = &(ltab[indx]);
277
24
		while (pt != NULL) {
278

24
			if ((pt->ino == arcn->sb.st_ino) &&
279
12
			    (pt->dev == arcn->sb.st_dev))
280
				break;
281
			ppt = &(pt->fow);
282
			pt = pt->fow;
283
		}
284
285
12
		if (pt != NULL) {
286
			/*
287
			 * found a link. set the node type and copy in the
288
			 * name of the file it is to link to. we need to
289
			 * handle hardlinks to regular files differently than
290
			 * other links.
291
			 */
292
12
			arcn->ln_nlen = strlcpy(arcn->ln_name, pt->name,
293
				sizeof(arcn->ln_name));
294
			/* XXX truncate? */
295
12
			if ((size_t)arcn->nlen >= sizeof(arcn->name))
296
				arcn->nlen = sizeof(arcn->name) - 1;
297
12
			if (arcn->type == PAX_REG)
298
				arcn->type = PAX_HRG;
299
			else
300
				arcn->type = PAX_HLK;
301
302
			/*
303
			 * if we have found all the links to this file, remove
304
			 * it from the database
305
			 */
306
12
			if (--pt->nlink <= 1) {
307
12
				*ppt = pt->fow;
308
12
				free(pt->name);
309
12
				free(pt);
310
12
			}
311
12
			return(1);
312
		}
313
	}
314
315
	/*
316
	 * we never saw this file before. It has links so we add it to the
317
	 * front of this hash chain
318
	 */
319
12
	if ((pt = malloc(sizeof(HRDLNK))) != NULL) {
320
12
		if ((pt->name = strdup(arcn->name)) != NULL) {
321
12
			pt->dev = arcn->sb.st_dev;
322
12
			pt->ino = arcn->sb.st_ino;
323
12
			pt->nlink = arcn->sb.st_nlink;
324
12
			pt->fow = ltab[indx];
325
12
			ltab[indx] = pt;
326
12
			return(0);
327
		}
328
		free(pt);
329
	}
330
331
	paxwarn(1, "Hard link table out of memory");
332
	return(-1);
333
113
}
334
335
/*
336
 * purg_lnk
337
 *	remove reference for a file that we may have added to the data base as
338
 *	a potential source for hard links. We ended up not using the file, so
339
 *	we do not want to accidently point another file at it later on.
340
 */
341
342
void
343
purg_lnk(ARCHD *arcn)
344
{
345
	HRDLNK *pt;
346
	HRDLNK **ppt;
347
	u_int indx;
348
349
	if (ltab == NULL)
350
		return;
351
	/*
352
	 * do not bother to look if it could not be in the database
353
	 */
354
	if ((arcn->sb.st_nlink <= 1) || (arcn->type == PAX_DIR) ||
355
	    PAX_IS_HARDLINK(arcn->type))
356
		return;
357
358
	/*
359
	 * find the hash chain for this inode value, if empty return
360
	 */
361
	indx = ((unsigned)arcn->sb.st_ino) % L_TAB_SZ;
362
	if ((pt = ltab[indx]) == NULL)
363
		return;
364
365
	/*
366
	 * walk down the list looking for the inode/dev pair, unlink and
367
	 * free if found
368
	 */
369
	ppt = &(ltab[indx]);
370
	while (pt != NULL) {
371
		if ((pt->ino == arcn->sb.st_ino) &&
372
		    (pt->dev == arcn->sb.st_dev))
373
			break;
374
		ppt = &(pt->fow);
375
		pt = pt->fow;
376
	}
377
	if (pt == NULL)
378
		return;
379
380
	/*
381
	 * remove and free it
382
	 */
383
	*ppt = pt->fow;
384
	free(pt->name);
385
	free(pt);
386
}
387
388
/*
389
 * lnk_end()
390
 *	pull apart a existing link table so we can reuse it. We do this between
391
 *	read and write phases of append with update. (The format may have
392
 *	used the link table, and we need to start with a fresh table for the
393
 *	write phase
394
 */
395
396
void
397
lnk_end(void)
398
{
399
	int i;
400
	HRDLNK *pt;
401
	HRDLNK *ppt;
402
403
36
	if (ltab == NULL)
404
18
		return;
405
406
	for (i = 0; i < L_TAB_SZ; ++i) {
407
		if (ltab[i] == NULL)
408
			continue;
409
		pt = ltab[i];
410
		ltab[i] = NULL;
411
412
		/*
413
		 * free up each entry on this chain
414
		 */
415
		while (pt != NULL) {
416
			ppt = pt;
417
			pt = ppt->fow;
418
			free(ppt->name);
419
			free(ppt);
420
		}
421
	}
422
18
}
423
424
/*
425
 * modification time table routines
426
 *
427
 * The modification time table keeps track of last modification times for all
428
 * files stored in an archive during a write phase when -u is set. We only
429
 * add a file to the archive if it is newer than a file with the same name
430
 * already stored on the archive (if there is no other file with the same
431
 * name on the archive it is added). This applies to writes and appends.
432
 * An append with an -u must read the archive and store the modification time
433
 * for every file on that archive before starting the write phase. It is clear
434
 * that this is one HUGE database. To save memory space, the actual file names
435
 * are stored in a scratch file and indexed by an in-memory hash table. The
436
 * hash table is indexed by hashing the file path. The nodes in the table store
437
 * the length of the filename and the lseek offset within the scratch file
438
 * where the actual name is stored. Since there are never any deletions from
439
 * this table, fragmentation of the scratch file is never a issue. Lookups
440
 * seem to not exhibit any locality at all (files in the database are rarely
441
 * looked up more than once...), so caching is just a waste of memory. The
442
 * only limitation is the amount of scratch file space available to store the
443
 * path names.
444
 */
445
446
/*
447
 * ftime_start()
448
 *	create the file time hash table and open for read/write the scratch
449
 *	file. (after created it is unlinked, so when we exit we leave
450
 *	no witnesses).
451
 * Return:
452
 *	0 if the table and file was created ok, -1 otherwise
453
 */
454
455
int
456
ftime_start(void)
457
{
458
459
	if (ftab != NULL)
460
		return(0);
461
	if ((ftab = calloc(F_TAB_SZ, sizeof(FTM *))) == NULL) {
462
		paxwarn(1, "Cannot allocate memory for file time table");
463
		return(-1);
464
	}
465
466
	/*
467
	 * get random name and create temporary scratch file, unlink name
468
	 * so it will get removed on exit
469
	 */
470
	memcpy(tempbase, _TFILE_BASE, sizeof(_TFILE_BASE));
471
	if ((ffd = mkstemp(tempfile)) < 0) {
472
		syswarn(1, errno, "Unable to create temporary file: %s",
473
		    tempfile);
474
		return(-1);
475
	}
476
	(void)unlink(tempfile);
477
478
	return(0);
479
}
480
481
/*
482
 * chk_ftime()
483
 *	looks up entry in file time hash table. If not found, the file is
484
 *	added to the hash table and the file named stored in the scratch file.
485
 *	If a file with the same name is found, the file times are compared and
486
 *	the most recent file time is retained. If the new file was younger (or
487
 *	was not in the database) the new file is selected for storage.
488
 * Return:
489
 *	0 if file should be added to the archive, 1 if it should be skipped,
490
 *	-1 on error
491
 */
492
493
int
494
chk_ftime(ARCHD *arcn)
495
{
496
	FTM *pt;
497
	int namelen;
498
	u_int indx;
499
	char ckname[PAXPATHLEN+1];
500
501
	/*
502
	 * no info, go ahead and add to archive
503
	 */
504
	if (ftab == NULL)
505
		return(0);
506
507
	/*
508
	 * hash the pathname and look up in table
509
	 */
510
	namelen = arcn->nlen;
511
	indx = st_hash(arcn->name, namelen, F_TAB_SZ);
512
	if ((pt = ftab[indx]) != NULL) {
513
		/*
514
		 * the hash chain is not empty, walk down looking for match
515
		 * only read up the path names if the lengths match, speeds
516
		 * up the search a lot
517
		 */
518
		while (pt != NULL) {
519
			if (pt->namelen == namelen) {
520
				/*
521
				 * potential match, have to read the name
522
				 * from the scratch file.
523
				 */
524
				if (lseek(ffd,pt->seek,SEEK_SET) != pt->seek) {
525
					syswarn(1, errno,
526
					    "Failed ftime table seek");
527
					return(-1);
528
				}
529
				if (read(ffd, ckname, namelen) != namelen) {
530
					syswarn(1, errno,
531
					    "Failed ftime table read");
532
					return(-1);
533
				}
534
535
				/*
536
				 * if the names match, we are done
537
				 */
538
				if (!strncmp(ckname, arcn->name, namelen))
539
					break;
540
			}
541
542
			/*
543
			 * try the next entry on the chain
544
			 */
545
			pt = pt->fow;
546
		}
547
548
		if (pt != NULL) {
549
			/*
550
			 * found the file, compare the times, save the newer
551
			 */
552
			if (timespeccmp(&arcn->sb.st_mtim, &pt->mtim, >)) {
553
				/*
554
				 * file is newer
555
				 */
556
				pt->mtim = arcn->sb.st_mtim;
557
				return(0);
558
			}
559
			/*
560
			 * file is older
561
			 */
562
			return(1);
563
		}
564
	}
565
566
	/*
567
	 * not in table, add it
568
	 */
569
	if ((pt = malloc(sizeof(FTM))) != NULL) {
570
		/*
571
		 * add the name at the end of the scratch file, saving the
572
		 * offset. add the file to the head of the hash chain
573
		 */
574
		if ((pt->seek = lseek(ffd, 0, SEEK_END)) >= 0) {
575
			if (write(ffd, arcn->name, namelen) == namelen) {
576
				pt->mtim = arcn->sb.st_mtim;
577
				pt->namelen = namelen;
578
				pt->fow = ftab[indx];
579
				ftab[indx] = pt;
580
				return(0);
581
			}
582
			syswarn(1, errno, "Failed write to file time table");
583
		} else
584
			syswarn(1, errno, "Failed seek on file time table");
585
	} else
586
		paxwarn(1, "File time table ran out of memory");
587
588
	if (pt != NULL)
589
		free(pt);
590
	return(-1);
591
}
592
593
/*
594
 * escaping (absolute or w/"..") symlink table routines
595
 *
596
 * By default, an archive shouldn't be able extract to outside of the
597
 * current directory.  What should we do if the archive contains a symlink
598
 * whose value is either absolute or contains ".." components?  What we'll
599
 * do is initially create the path as an empty file (to block attempts to
600
 * reference _through_ it) and instead record its path and desired
601
 * final value and mode.  Then once all the other archive
602
 * members are created (but before the pass to set timestamps on
603
 * directories) we'll process those records, replacing the placeholder with
604
 * the correct symlink and setting them to the correct mode, owner, group,
605
 * and timestamps.
606
 *
607
 * Note: we also need to handle hardlinks to symlinks (barf) as well as
608
 * hardlinks whose target is replaced by a later entry in the archive (barf^2).
609
 *
610
 * So we track things by dev+ino of the placeholder file, associating with
611
 * that the value and mode of the final symlink and a list of paths that
612
 * should all be hardlinks of that.  We'll 'store' the symlink's desired
613
 * timestamps, owner, and group by setting them on the placeholder file.
614
 *
615
 * The operations are:
616
 * a) create an escaping symlink: create the placeholder file and add an entry
617
 *    for the new link
618
 * b) create a hardlink: do the link.  If the target turns out to be a
619
 *    zero-length file whose dev+ino are in the symlink table, then add this
620
 *    path to the list of names for that link
621
 * c) perform deferred processing: for each entry, check each associated path:
622
 *    if it's a zero-length file with the correct dev+ino then recreate it as
623
 *    the specified symlink or hardlink to the first such
624
 */
625
626
struct slpath {
627
	char	*sp_path;
628
	struct	slpath *sp_next;
629
};
630
struct slinode {
631
	ino_t	sli_ino;
632
	char	*sli_value;
633
	struct	slpath sli_paths;
634
	struct	slinode *sli_fow;		/* hash table chain */
635
	dev_t	sli_dev;
636
	mode_t	sli_mode;
637
};
638
639
static struct slinode **slitab = NULL;
640
641
/*
642
 * sltab_start()
643
 *	create the hash table
644
 * Return:
645
 *	0 if the table and file was created ok, -1 otherwise
646
 */
647
648
int
649
sltab_start(void)
650
{
651
652
12
	if ((slitab = calloc(SL_TAB_SZ, sizeof *slitab)) == NULL) {
653
		syswarn(1, errno, "symlink table");
654
		return(-1);
655
	}
656
657
6
	return(0);
658
6
}
659
660
/*
661
 * sltab_add_sym()
662
 *	Create the placeholder and tracking info for an escaping symlink.
663
 * Return:
664
 *	0 on success, -1 otherwise
665
 */
666
667
int
668
sltab_add_sym(const char *path0, const char *value0, mode_t mode)
669
{
670
	struct stat sb;
671
	struct slinode *s;
672
	struct slpath *p;
673
	char *path, *value;
674
	u_int indx;
675
	int fd;
676
677
	/* create the placeholder */
678
	fd = open(path0, O_WRONLY | O_CREAT | O_EXCL | O_CLOEXEC, 0600);
679
	if (fd == -1)
680
		return (-1);
681
	if (fstat(fd, &sb) == -1) {
682
		unlink(path0);
683
		close(fd);
684
		return (-1);
685
	}
686
	close(fd);
687
688
	if (havechd && *path0 != '/') {
689
		if ((path = realpath(path0, NULL)) == NULL) {
690
			syswarn(1, errno, "Cannot canonicalize %s", path0);
691
			unlink(path0);
692
			return (-1);
693
		}
694
	} else if ((path = strdup(path0)) == NULL) {
695
		syswarn(1, errno, "defered symlink path");
696
		unlink(path0);
697
		return (-1);
698
	}
699
	if ((value = strdup(value0)) == NULL) {
700
		syswarn(1, errno, "defered symlink value");
701
		unlink(path);
702
		free(path);
703
		return (-1);
704
	}
705
706
	/* now check the hash table for conflicting entry */
707
	indx = (sb.st_ino ^ sb.st_dev) % SL_TAB_SZ;
708
	for (s = slitab[indx]; s != NULL; s = s->sli_fow) {
709
		if (s->sli_ino != sb.st_ino || s->sli_dev != sb.st_dev)
710
			continue;
711
712
		/*
713
		 * One of our placeholders got removed behind our back and
714
		 * we've reused the inode.  Weird, but clean up the mess.
715
		 */
716
		free(s->sli_value);
717
		free(s->sli_paths.sp_path);
718
		p = s->sli_paths.sp_next;
719
		while (p != NULL) {
720
			struct slpath *next_p = p->sp_next;
721
722
			free(p->sp_path);
723
			free(p);
724
			p = next_p;
725
		}
726
		goto set_value;
727
	}
728
729
	/* Normal case: create a new node */
730
	if ((s = malloc(sizeof *s)) == NULL) {
731
		syswarn(1, errno, "defered symlink");
732
		unlink(path);
733
		free(path);
734
		free(value);
735
		return (-1);
736
	}
737
	s->sli_ino = sb.st_ino;
738
	s->sli_dev = sb.st_dev;
739
	s->sli_fow = slitab[indx];
740
	slitab[indx] = s;
741
742
set_value:
743
	s->sli_paths.sp_path = path;
744
	s->sli_paths.sp_next = NULL;
745
	s->sli_value = value;
746
	s->sli_mode = mode;
747
	return (0);
748
}
749
750
/*
751
 * sltab_add_link()
752
 *	A hardlink was created; if it looks like a placeholder, handle the
753
 *	tracking.
754
 * Return:
755
 *	0 if things are ok, -1 if something went wrong
756
 */
757
758
int
759
sltab_add_link(const char *path, const struct stat *sb)
760
{
761
	struct slinode *s;
762
	struct slpath *p;
763
	u_int indx;
764
765

36
	if (!S_ISREG(sb->st_mode) || sb->st_size != 0)
766
		return (1);
767
768
	/* find the hash table entry for this hardlink */
769
12
	indx = (sb->st_ino ^ sb->st_dev) % SL_TAB_SZ;
770
24
	for (s = slitab[indx]; s != NULL; s = s->sli_fow) {
771
		if (s->sli_ino != sb->st_ino || s->sli_dev != sb->st_dev)
772
			continue;
773
774
		if ((p = malloc(sizeof *p)) == NULL) {
775
			syswarn(1, errno, "deferred symlink hardlink");
776
			return (-1);
777
		}
778
		if (havechd && *path != '/') {
779
			if ((p->sp_path = realpath(path, NULL)) == NULL) {
780
				syswarn(1, errno, "Cannot canonicalize %s",
781
				    path);
782
				free(p);
783
				return (-1);
784
			}
785
		} else if ((p->sp_path = strdup(path)) == NULL) {
786
			syswarn(1, errno, "defered symlink hardlink path");
787
			free(p);
788
			return (-1);
789
		}
790
791
		/* link it in */
792
		p->sp_next = s->sli_paths.sp_next;
793
		s->sli_paths.sp_next = p;
794
		return (0);
795
	}
796
797
	/* not found */
798
12
	return (1);
799
12
}
800
801
802
static int
803
sltab_process_one(struct slinode *s, struct slpath *p, const char *first,
804
    int in_sig)
805
{
806
	struct stat sb;
807
	char *path = p->sp_path;
808
	mode_t mode;
809
	int err;
810
811
	/*
812
	 * is it the expected placeholder?  This can fail legimately
813
	 * if the archive overwrote the link with another, later entry,
814
	 * so don't warn.
815
	 */
816
	if (stat(path, &sb) != 0 || !S_ISREG(sb.st_mode) || sb.st_size != 0 ||
817
	    sb.st_ino != s->sli_ino || sb.st_dev != s->sli_dev)
818
		return (0);
819
820
	if (unlink(path) && errno != ENOENT) {
821
		if (!in_sig)
822
			syswarn(1, errno, "deferred symlink removal");
823
		return (0);
824
	}
825
826
	err = 0;
827
	if (first != NULL) {
828
		/* add another hardlink to the existing symlink */
829
		if (linkat(AT_FDCWD, first, AT_FDCWD, path, 0) == 0)
830
			return (0);
831
832
		/*
833
		 * Couldn't hardlink the symlink for some reason, so we'll
834
		 * try creating it as its own symlink, but save the error
835
		 * for reporting if that fails.
836
		 */
837
		err = errno;
838
	}
839
840
	if (symlink(s->sli_value, path)) {
841
		if (!in_sig) {
842
			const char *qualifier = "";
843
			if (err)
844
				qualifier = " hardlink";
845
			else
846
				err = errno;
847
848
			syswarn(1, err, "deferred symlink%s: %s",
849
			    qualifier, path);
850
		}
851
		return (0);
852
	}
853
854
	/* success, so set the id, mode, and times */
855
	mode = s->sli_mode;
856
	if (pids) {
857
		/* if can't set the ids, force the set[ug]id bits off */
858
		if (set_ids(path, sb.st_uid, sb.st_gid))
859
			mode &= ~(SETBITS);
860
	}
861
862
	if (pmode)
863
		set_pmode(path, mode);
864
865
	if (patime || pmtime)
866
		set_ftime(path, &sb.st_mtim, &sb.st_atim, 0);
867
868
	/*
869
	 * If we tried to link to first but failed, then this new symlink
870
	 * might be a better one to try in the future.  Guess from the errno.
871
	 */
872
	if (err == 0 || err == ENOENT || err == EMLINK || err == EOPNOTSUPP)
873
		return (1);
874
	return (0);
875
}
876
877
/*
878
 * sltab_process()
879
 *	Do all the delayed process for escape symlinks
880
 */
881
882
void
883
sltab_process(int in_sig)
884
{
885
	struct slinode *s;
886
	struct slpath *p;
887
	char *first;
888
	u_int indx;
889
890
12
	if (slitab == NULL)
891
		return;
892
893
	/* walk across the entire hash table */
894
3816
	for (indx = 0; indx < SL_TAB_SZ; indx++) {
895
3804
		while ((s = slitab[indx]) != NULL) {
896
			/* pop this entry */
897
			slitab[indx] = s->sli_fow;
898
899
			first = NULL;
900
			p = &s->sli_paths;
901
			while (1) {
902
				struct slpath *next_p;
903
904
				if (sltab_process_one(s, p, first, in_sig)) {
905
					if (!in_sig)
906
						free(first);
907
					first = p->sp_path;
908
				} else if (!in_sig)
909
					free(p->sp_path);
910
911
				if ((next_p = p->sp_next) == NULL)
912
					break;
913
				*p = *next_p;
914
				if (!in_sig)
915
					free(next_p);
916
			}
917
			if (!in_sig) {
918
				free(first);
919
				free(s->sli_value);
920
				free(s);
921
			}
922
		}
923
	}
924
6
	if (!in_sig)
925
6
		free(slitab);
926
6
	slitab = NULL;
927
12
}
928
929
930
/*
931
 * Interactive rename table routines
932
 *
933
 * The interactive rename table keeps track of the new names that the user
934
 * assigns to files from tty input. Since this map is unique for each file
935
 * we must store it in case there is a reference to the file later in archive
936
 * (a link). Otherwise we will be unable to find the file we know was
937
 * extracted. The remapping of these files is stored in a memory based hash
938
 * table (it is assumed since input must come from /dev/tty, it is unlikely to
939
 * be a very large table).
940
 */
941
942
/*
943
 * name_start()
944
 *	create the interactive rename table
945
 * Return:
946
 *	0 if successful, -1 otherwise
947
 */
948
949
int
950
name_start(void)
951
{
952
	if (ntab != NULL)
953
		return(0);
954
	if ((ntab = calloc(N_TAB_SZ, sizeof(NAMT *))) == NULL) {
955
		paxwarn(1, "Cannot allocate memory for interactive rename table");
956
		return(-1);
957
	}
958
	return(0);
959
}
960
961
/*
962
 * add_name()
963
 *	add the new name to old name mapping just created by the user.
964
 *	If an old name mapping is found (there may be duplicate names on an
965
 *	archive) only the most recent is kept.
966
 * Return:
967
 *	0 if added, -1 otherwise
968
 */
969
970
int
971
add_name(char *oname, int onamelen, char *nname)
972
{
973
	NAMT *pt;
974
	u_int indx;
975
976
	if (ntab == NULL) {
977
		/*
978
		 * should never happen
979
		 */
980
		paxwarn(0, "No interactive rename table, links may fail");
981
		return(0);
982
	}
983
984
	/*
985
	 * look to see if we have already mapped this file, if so we
986
	 * will update it
987
	 */
988
	indx = st_hash(oname, onamelen, N_TAB_SZ);
989
	if ((pt = ntab[indx]) != NULL) {
990
		/*
991
		 * look down the has chain for the file
992
		 */
993
		while ((pt != NULL) && (strcmp(oname, pt->oname) != 0))
994
			pt = pt->fow;
995
996
		if (pt != NULL) {
997
			/*
998
			 * found an old mapping, replace it with the new one
999
			 * the user just input (if it is different)
1000
			 */
1001
			if (strcmp(nname, pt->nname) == 0)
1002
				return(0);
1003
1004
			free(pt->nname);
1005
			if ((pt->nname = strdup(nname)) == NULL) {
1006
				paxwarn(1, "Cannot update rename table");
1007
				return(-1);
1008
			}
1009
			return(0);
1010
		}
1011
	}
1012
1013
	/*
1014
	 * this is a new mapping, add it to the table
1015
	 */
1016
	if ((pt = malloc(sizeof(NAMT))) != NULL) {
1017
		if ((pt->oname = strdup(oname)) != NULL) {
1018
			if ((pt->nname = strdup(nname)) != NULL) {
1019
				pt->fow = ntab[indx];
1020
				ntab[indx] = pt;
1021
				return(0);
1022
			}
1023
			free(pt->oname);
1024
		}
1025
		free(pt);
1026
	}
1027
	paxwarn(1, "Interactive rename table out of memory");
1028
	return(-1);
1029
}
1030
1031
/*
1032
 * sub_name()
1033
 *	look up a link name to see if it points at a file that has been
1034
 *	remapped by the user. If found, the link is adjusted to contain the
1035
 *	new name (oname is the link to name)
1036
 */
1037
1038
void
1039
sub_name(char *oname, int *onamelen, int onamesize)
1040
{
1041
	NAMT *pt;
1042
	u_int indx;
1043
1044
	if (ntab == NULL)
1045
		return;
1046
	/*
1047
	 * look the name up in the hash table
1048
	 */
1049
	indx = st_hash(oname, *onamelen, N_TAB_SZ);
1050
	if ((pt = ntab[indx]) == NULL)
1051
		return;
1052
1053
	while (pt != NULL) {
1054
		/*
1055
		 * walk down the hash chain looking for a match
1056
		 */
1057
		if (strcmp(oname, pt->oname) == 0) {
1058
			/*
1059
			 * found it, replace it with the new name
1060
			 * and return (we know that oname has enough space)
1061
			 */
1062
			*onamelen = strlcpy(oname, pt->nname, onamesize);
1063
			if (*onamelen >= onamesize)
1064
				*onamelen = onamesize - 1; /* XXX truncate? */
1065
			return;
1066
		}
1067
		pt = pt->fow;
1068
	}
1069
1070
	/*
1071
	 * no match, just return
1072
	 */
1073
}
1074
1075
#ifndef NOCPIO
1076
/*
1077
 * device/inode mapping table routines
1078
 * (used with formats that store device and inodes fields)
1079
 *
1080
 * device/inode mapping tables remap the device field in a archive header. The
1081
 * device/inode fields are used to determine when files are hard links to each
1082
 * other. However these values have very little meaning outside of that. This
1083
 * database is used to solve one of two different problems.
1084
 *
1085
 * 1) when files are appended to an archive, while the new files may have hard
1086
 * links to each other, you cannot determine if they have hard links to any
1087
 * file already stored on the archive from a prior run of pax. We must assume
1088
 * that these inode/device pairs are unique only within a SINGLE run of pax
1089
 * (which adds a set of files to an archive). So we have to make sure the
1090
 * inode/dev pairs we add each time are always unique. We do this by observing
1091
 * while the inode field is very dense, the use of the dev field is fairly
1092
 * sparse. Within each run of pax, we remap any device number of a new archive
1093
 * member that has a device number used in a prior run and already stored in a
1094
 * file on the archive. During the read phase of the append, we store the
1095
 * device numbers used and mark them to not be used by any file during the
1096
 * write phase. If during write we go to use one of those old device numbers,
1097
 * we remap it to a new value.
1098
 *
1099
 * 2) Often the fields in the archive header used to store these values are
1100
 * too small to store the entire value. The result is an inode or device value
1101
 * which can be truncated. This really can foul up an archive. With truncation
1102
 * we end up creating links between files that are really not links (after
1103
 * truncation the inodes are the same value). We address that by detecting
1104
 * truncation and forcing a remap of the device field to split truncated
1105
 * inodes away from each other. Each truncation creates a pattern of bits that
1106
 * are removed. We use this pattern of truncated bits to partition the inodes
1107
 * on a single device to many different devices (each one represented by the
1108
 * truncated bit pattern). All inodes on the same device that have the same
1109
 * truncation pattern are mapped to the same new device. Two inodes that
1110
 * truncate to the same value clearly will always have different truncation
1111
 * bit patterns, so they will be split from away each other. When we spot
1112
 * device truncation we remap the device number to a non truncated value.
1113
 * (for more info see table.h for the data structures involved).
1114
 */
1115
1116
static DEVT *chk_dev(dev_t, int);
1117
1118
/*
1119
 * dev_start()
1120
 *	create the device mapping table
1121
 * Return:
1122
 *	0 if successful, -1 otherwise
1123
 */
1124
1125
int
1126
dev_start(void)
1127
{
1128
	if (dtab != NULL)
1129
		return(0);
1130
	if ((dtab = calloc(D_TAB_SZ, sizeof(DEVT *))) == NULL) {
1131
		paxwarn(1, "Cannot allocate memory for device mapping table");
1132
		return(-1);
1133
	}
1134
	return(0);
1135
}
1136
1137
/*
1138
 * add_dev()
1139
 *	add a device number to the table. this will force the device to be
1140
 *	remapped to a new value if it be used during a write phase. This
1141
 *	function is called during the read phase of an append to prohibit the
1142
 *	use of any device number already in the archive.
1143
 * Return:
1144
 *	0 if added ok, -1 otherwise
1145
 */
1146
1147
int
1148
add_dev(ARCHD *arcn)
1149
{
1150
	if (chk_dev(arcn->sb.st_dev, 1) == NULL)
1151
		return(-1);
1152
	return(0);
1153
}
1154
1155
/*
1156
 * chk_dev()
1157
 *	check for a device value in the device table. If not found and the add
1158
 *	flag is set, it is added. This does NOT assign any mapping values, just
1159
 *	adds the device number as one that need to be remapped. If this device
1160
 *	is already mapped, just return with a pointer to that entry.
1161
 * Return:
1162
 *	pointer to the entry for this device in the device map table. Null
1163
 *	if the add flag is not set and the device is not in the table (it is
1164
 *	not been seen yet). If add is set and the device cannot be added, null
1165
 *	is returned (indicates an error).
1166
 */
1167
1168
static DEVT *
1169
chk_dev(dev_t dev, int add)
1170
{
1171
	DEVT *pt;
1172
	u_int indx;
1173
1174
	if (dtab == NULL)
1175
		return(NULL);
1176
	/*
1177
	 * look to see if this device is already in the table
1178
	 */
1179
	indx = ((unsigned)dev) % D_TAB_SZ;
1180
	if ((pt = dtab[indx]) != NULL) {
1181
		while ((pt != NULL) && (pt->dev != dev))
1182
			pt = pt->fow;
1183
1184
		/*
1185
		 * found it, return a pointer to it
1186
		 */
1187
		if (pt != NULL)
1188
			return(pt);
1189
	}
1190
1191
	/*
1192
	 * not in table, we add it only if told to as this may just be a check
1193
	 * to see if a device number is being used.
1194
	 */
1195
	if (add == 0)
1196
		return(NULL);
1197
1198
	/*
1199
	 * allocate a node for this device and add it to the front of the hash
1200
	 * chain. Note we do not assign remaps values here, so the pt->list
1201
	 * list must be NULL.
1202
	 */
1203
	if ((pt = malloc(sizeof(DEVT))) == NULL) {
1204
		paxwarn(1, "Device map table out of memory");
1205
		return(NULL);
1206
	}
1207
	pt->dev = dev;
1208
	pt->list = NULL;
1209
	pt->fow = dtab[indx];
1210
	dtab[indx] = pt;
1211
	return(pt);
1212
}
1213
/*
1214
 * map_dev()
1215
 *	given an inode and device storage mask (the mask has a 1 for each bit
1216
 *	the archive format is able to store in a header), we check for inode
1217
 *	and device truncation and remap the device as required. Device mapping
1218
 *	can also occur when during the read phase of append a device number was
1219
 *	seen (and was marked as do not use during the write phase). WE ASSUME
1220
 *	that unsigned longs are the same size or bigger than the fields used
1221
 *	for ino_t and dev_t. If not the types will have to be changed.
1222
 * Return:
1223
 *	0 if all ok, -1 otherwise.
1224
 */
1225
1226
int
1227
map_dev(ARCHD *arcn, u_long dev_mask, u_long ino_mask)
1228
{
1229
	DEVT *pt;
1230
	DLIST *dpt;
1231
	static dev_t lastdev = 0;	/* next device number to try */
1232
	int trc_ino = 0;
1233
	int trc_dev = 0;
1234
	ino_t trunc_bits = 0;
1235
	ino_t nino;
1236
1237
	if (dtab == NULL)
1238
		return(0);
1239
	/*
1240
	 * check for device and inode truncation, and extract the truncated
1241
	 * bit pattern.
1242
	 */
1243
	if ((arcn->sb.st_dev & (dev_t)dev_mask) != arcn->sb.st_dev)
1244
		++trc_dev;
1245
	if ((nino = arcn->sb.st_ino & (ino_t)ino_mask) != arcn->sb.st_ino) {
1246
		++trc_ino;
1247
		trunc_bits = arcn->sb.st_ino & (ino_t)(~ino_mask);
1248
	}
1249
1250
	/*
1251
	 * see if this device is already being mapped, look up the device
1252
	 * then find the truncation bit pattern which applies
1253
	 */
1254
	if ((pt = chk_dev(arcn->sb.st_dev, 0)) != NULL) {
1255
		/*
1256
		 * this device is already marked to be remapped
1257
		 */
1258
		for (dpt = pt->list; dpt != NULL; dpt = dpt->fow)
1259
			if (dpt->trunc_bits == trunc_bits)
1260
				break;
1261
1262
		if (dpt != NULL) {
1263
			/*
1264
			 * we are being remapped for this device and pattern
1265
			 * change the device number to be stored and return
1266
			 */
1267
			arcn->sb.st_dev = dpt->dev;
1268
			arcn->sb.st_ino = nino;
1269
			return(0);
1270
		}
1271
	} else {
1272
		/*
1273
		 * this device is not being remapped YET. if we do not have any
1274
		 * form of truncation, we do not need a remap
1275
		 */
1276
		if (!trc_ino && !trc_dev)
1277
			return(0);
1278
1279
		/*
1280
		 * we have truncation, have to add this as a device to remap
1281
		 */
1282
		if ((pt = chk_dev(arcn->sb.st_dev, 1)) == NULL)
1283
			goto bad;
1284
1285
		/*
1286
		 * if we just have a truncated inode, we have to make sure that
1287
		 * all future inodes that do not truncate (they have the
1288
		 * truncation pattern of all 0's) continue to map to the same
1289
		 * device number. We probably have already written inodes with
1290
		 * this device number to the archive with the truncation
1291
		 * pattern of all 0's. So we add the mapping for all 0's to the
1292
		 * same device number.
1293
		 */
1294
		if (!trc_dev && (trunc_bits != 0)) {
1295
			if ((dpt = malloc(sizeof(DLIST))) == NULL)
1296
				goto bad;
1297
			dpt->trunc_bits = 0;
1298
			dpt->dev = arcn->sb.st_dev;
1299
			dpt->fow = pt->list;
1300
			pt->list = dpt;
1301
		}
1302
	}
1303
1304
	/*
1305
	 * look for a device number not being used. We must watch for wrap
1306
	 * around on lastdev (so we do not get stuck looking forever!)
1307
	 */
1308
	while (++lastdev > 0) {
1309
		if (chk_dev(lastdev, 0) != NULL)
1310
			continue;
1311
		/*
1312
		 * found an unused value. If we have reached truncation point
1313
		 * for this format we are hosed, so we give up. Otherwise we
1314
		 * mark it as being used.
1315
		 */
1316
		if (((lastdev & ((dev_t)dev_mask)) != lastdev) ||
1317
		    (chk_dev(lastdev, 1) == NULL))
1318
			goto bad;
1319
		break;
1320
	}
1321
1322
	if ((lastdev <= 0) || ((dpt = malloc(sizeof(DLIST))) == NULL))
1323
		goto bad;
1324
1325
	/*
1326
	 * got a new device number, store it under this truncation pattern.
1327
	 * change the device number this file is being stored with.
1328
	 */
1329
	dpt->trunc_bits = trunc_bits;
1330
	dpt->dev = lastdev;
1331
	dpt->fow = pt->list;
1332
	pt->list = dpt;
1333
	arcn->sb.st_dev = lastdev;
1334
	arcn->sb.st_ino = nino;
1335
	return(0);
1336
1337
    bad:
1338
	paxwarn(1, "Unable to fix truncated inode/device field when storing %s",
1339
	    arcn->name);
1340
	paxwarn(0, "Archive may create improper hard links when extracted");
1341
	return(0);
1342
}
1343
#endif /* NOCPIO */
1344
1345
/*
1346
 * directory access/mod time reset table routines (for directories READ by pax)
1347
 *
1348
 * The pax -t flag requires that access times of archive files be the same
1349
 * before being read by pax. For regular files, access time is restored after
1350
 * the file has been copied. This database provides the same functionality for
1351
 * directories read during file tree traversal. Restoring directory access time
1352
 * is more complex than files since directories may be read several times until
1353
 * all the descendants in their subtree are visited by fts. Directory access
1354
 * and modification times are stored during the fts pre-order visit (done
1355
 * before any descendants in the subtree are visited) and restored after the
1356
 * fts post-order visit (after all the descendants have been visited). In the
1357
 * case of premature exit from a subtree (like from the effects of -n), any
1358
 * directory entries left in this database are reset during final cleanup
1359
 * operations of pax. Entries are hashed by inode number for fast lookup.
1360
 */
1361
1362
/*
1363
 * atdir_start()
1364
 *	create the directory access time database for directories READ by pax.
1365
 * Return:
1366
 *	0 is created ok, -1 otherwise.
1367
 */
1368
1369
int
1370
atdir_start(void)
1371
{
1372
	if (atab != NULL)
1373
		return(0);
1374
	if ((atab = calloc(A_TAB_SZ, sizeof(ATDIR *))) == NULL) {
1375
		paxwarn(1,"Cannot allocate space for directory access time table");
1376
		return(-1);
1377
	}
1378
	return(0);
1379
}
1380
1381
1382
/*
1383
 * atdir_end()
1384
 *	walk through the directory access time table and reset the access time
1385
 *	of any directory who still has an entry left in the database. These
1386
 *	entries are for directories READ by pax
1387
 */
1388
1389
void
1390
atdir_end(void)
1391
{
1392
	ATDIR *pt;
1393
	int i;
1394
1395
	if (atab == NULL)
1396
		return;
1397
	/*
1398
	 * for each non-empty hash table entry reset all the directories
1399
	 * chained there.
1400
	 */
1401
	for (i = 0; i < A_TAB_SZ; ++i) {
1402
		if ((pt = atab[i]) == NULL)
1403
			continue;
1404
		/*
1405
		 * remember to force the times, set_ftime() looks at pmtime
1406
		 * and patime, which only applies to things CREATED by pax,
1407
		 * not read by pax. Read time reset is controlled by -t.
1408
		 */
1409
		for (; pt != NULL; pt = pt->fow)
1410
			set_attr(&pt->ft, 1, 0, 0, 0);
1411
	}
1412
}
1413
1414
/*
1415
 * add_atdir()
1416
 *	add a directory to the directory access time table. Table is hashed
1417
 *	and chained by inode number. This is for directories READ by pax
1418
 */
1419
1420
void
1421
add_atdir(char *fname, dev_t dev, ino_t ino, const struct timespec *mtimp,
1422
    const struct timespec *atimp)
1423
{
1424
	ATDIR *pt;
1425
	sigset_t allsigs, savedsigs;
1426
	u_int indx;
1427
1428
	if (atab == NULL)
1429
		return;
1430
1431
	/*
1432
	 * make sure this directory is not already in the table, if so just
1433
	 * return (the older entry always has the correct time). The only
1434
	 * way this will happen is when the same subtree can be traversed by
1435
	 * different args to pax and the -n option is aborting fts out of a
1436
	 * subtree before all the post-order visits have been made.
1437
	 */
1438
	indx = ((unsigned)ino) % A_TAB_SZ;
1439
	if ((pt = atab[indx]) != NULL) {
1440
		while (pt != NULL) {
1441
			if ((pt->ft.ft_ino == ino) && (pt->ft.ft_dev == dev))
1442
				break;
1443
			pt = pt->fow;
1444
		}
1445
1446
		/*
1447
		 * oops, already there. Leave it alone.
1448
		 */
1449
		if (pt != NULL)
1450
			return;
1451
	}
1452
1453
	/*
1454
	 * add it to the front of the hash chain
1455
	 */
1456
	sigfillset(&allsigs);
1457
	sigprocmask(SIG_BLOCK, &allsigs, &savedsigs);
1458
	if ((pt = malloc(sizeof *pt)) != NULL) {
1459
		if ((pt->ft.ft_name = strdup(fname)) != NULL) {
1460
			pt->ft.ft_dev = dev;
1461
			pt->ft.ft_ino = ino;
1462
			pt->ft.ft_mtim = *mtimp;
1463
			pt->ft.ft_atim = *atimp;
1464
			pt->fow = atab[indx];
1465
			atab[indx] = pt;
1466
			sigprocmask(SIG_SETMASK, &savedsigs, NULL);
1467
			return;
1468
		}
1469
		free(pt);
1470
	}
1471
1472
	sigprocmask(SIG_SETMASK, &savedsigs, NULL);
1473
	paxwarn(1, "Directory access time reset table ran out of memory");
1474
}
1475
1476
/*
1477
 * get_atdir()
1478
 *	look up a directory by inode and device number to obtain the access
1479
 *	and modification time you want to set to. If found, the modification
1480
 *	and access time parameters are set and the entry is removed from the
1481
 *	table (as it is no longer needed). These are for directories READ by
1482
 *	pax
1483
 * Return:
1484
 *	0 if found, -1 if not found.
1485
 */
1486
1487
int
1488
do_atdir(const char *name, dev_t dev, ino_t ino)
1489
{
1490
	ATDIR *pt;
1491
	ATDIR **ppt;
1492
	sigset_t allsigs, savedsigs;
1493
	u_int indx;
1494
1495
	if (atab == NULL)
1496
		return(-1);
1497
	/*
1498
	 * hash by inode and search the chain for an inode and device match
1499
	 */
1500
	indx = ((unsigned)ino) % A_TAB_SZ;
1501
	if ((pt = atab[indx]) == NULL)
1502
		return(-1);
1503
1504
	ppt = &(atab[indx]);
1505
	while (pt != NULL) {
1506
		if ((pt->ft.ft_ino == ino) && (pt->ft.ft_dev == dev))
1507
			break;
1508
		/*
1509
		 * no match, go to next one
1510
		 */
1511
		ppt = &(pt->fow);
1512
		pt = pt->fow;
1513
	}
1514
1515
	/*
1516
	 * return if we did not find it.
1517
	 */
1518
	if (pt == NULL || pt->ft.ft_name == NULL ||
1519
	    strcmp(name, pt->ft.ft_name) == 0)
1520
		return(-1);
1521
1522
	/*
1523
	 * found it. set the times and remove the entry from the table.
1524
	 */
1525
	set_attr(&pt->ft, 1, 0, 0, 0);
1526
	sigfillset(&allsigs);
1527
	sigprocmask(SIG_BLOCK, &allsigs, &savedsigs);
1528
	*ppt = pt->fow;
1529
	sigprocmask(SIG_SETMASK, &savedsigs, NULL);
1530
	free(pt->ft.ft_name);
1531
	free(pt);
1532
	return(0);
1533
}
1534
1535
/*
1536
 * directory access mode and time storage routines (for directories CREATED
1537
 * by pax).
1538
 *
1539
 * Pax requires that extracted directories, by default, have their access/mod
1540
 * times and permissions set to the values specified in the archive. During the
1541
 * actions of extracting (and creating the destination subtree during -rw copy)
1542
 * directories extracted may be modified after being created. Even worse is
1543
 * that these directories may have been created with file permissions which
1544
 * prohibits any descendants of these directories from being extracted. When
1545
 * directories are created by pax, access rights may be added to permit the
1546
 * creation of files in their subtree. Every time pax creates a directory, the
1547
 * times and file permissions specified by the archive are stored. After all
1548
 * files have been extracted (or copied), these directories have their times
1549
 * and file modes reset to the stored values. The directory info is restored in
1550
 * reverse order as entries were added from root to leaf: to restore atime
1551
 * properly, we must go backwards.
1552
 */
1553
1554
/*
1555
 * dir_start()
1556
 *	set up the directory time and file mode storage for directories CREATED
1557
 *	by pax.
1558
 * Return:
1559
 *	0 if ok, -1 otherwise
1560
 */
1561
1562
int
1563
dir_start(void)
1564
{
1565
12
	if (dirp != NULL)
1566
		return(0);
1567
1568
6
	dirsize = DIRP_SIZE;
1569
6
	if ((dirp = reallocarray(NULL, dirsize, sizeof(DIRDATA))) == NULL) {
1570
		paxwarn(1, "Unable to allocate memory for directory times");
1571
		return(-1);
1572
	}
1573
6
	return(0);
1574
6
}
1575
1576
/*
1577
 * add_dir()
1578
 *	add the mode and times for a newly CREATED directory
1579
 *	name is name of the directory, psb the stat buffer with the data in it,
1580
 *	frc_mode is a flag that says whether to force the setting of the mode
1581
 *	(ignoring the user set values for preserving file mode). Frc_mode is
1582
 *	for the case where we created a file and found that the resulting
1583
 *	directory was not writeable and the user asked for file modes to NOT
1584
 *	be preserved. (we have to preserve what was created by default, so we
1585
 *	have to force the setting at the end. this is stated explicitly in the
1586
 *	pax spec)
1587
 */
1588
1589
void
1590
add_dir(char *name, struct stat *psb, int frc_mode)
1591
{
1592
	DIRDATA *dblk;
1593
24
	sigset_t allsigs, savedsigs;
1594
12
	char realname[PATH_MAX], *rp;
1595
1596
12
	if (dirp == NULL)
1597
		return;
1598
1599

12
	if (havechd && *name != '/') {
1600
		if ((rp = realpath(name, realname)) == NULL) {
1601
			paxwarn(1, "Cannot canonicalize %s", name);
1602
			return;
1603
		}
1604
		name = rp;
1605
	}
1606
12
	if (dircnt == dirsize) {
1607
		dblk = reallocarray(dirp, dirsize * 2, sizeof(DIRDATA));
1608
		if (dblk == NULL) {
1609
			paxwarn(1, "Unable to store mode and times for created"
1610
			    " directory: %s", name);
1611
			return;
1612
		}
1613
		sigprocmask(SIG_BLOCK, &allsigs, &savedsigs);
1614
		dirp = dblk;
1615
		dirsize *= 2;
1616
		sigprocmask(SIG_SETMASK, &savedsigs, NULL);
1617
	}
1618
12
	dblk = &dirp[dircnt];
1619
12
	if ((dblk->ft.ft_name = strdup(name)) == NULL) {
1620
		paxwarn(1, "Unable to store mode and times for created"
1621
		    " directory: %s", name);
1622
		return;
1623
	}
1624
12
	dblk->ft.ft_mtim = psb->st_mtim;
1625
12
	dblk->ft.ft_atim = psb->st_atim;
1626
12
	dblk->ft.ft_ino = psb->st_ino;
1627
12
	dblk->ft.ft_dev = psb->st_dev;
1628
12
	dblk->mode = psb->st_mode & ABITS;
1629
12
	dblk->frc_mode = frc_mode;
1630
12
	sigprocmask(SIG_BLOCK, &allsigs, &savedsigs);
1631
12
	++dircnt;
1632
12
	sigprocmask(SIG_SETMASK, &savedsigs, NULL);
1633
24
}
1634
1635
/*
1636
 * delete_dir()
1637
 *	When we rmdir a directory, we may want to make sure we don't
1638
 *	later warn about being unable to set its mode and times.
1639
 */
1640
1641
void
1642
delete_dir(dev_t dev, ino_t ino)
1643
{
1644
	DIRDATA *dblk;
1645
	char *name;
1646
	size_t i;
1647
1648
	if (dirp == NULL)
1649
		return;
1650
	for (i = 0; i < dircnt; i++) {
1651
		dblk = &dirp[i];
1652
1653
		if (dblk->ft.ft_name == NULL)
1654
			continue;
1655
		if (dblk->ft.ft_dev == dev && dblk->ft.ft_ino == ino) {
1656
			name = dblk->ft.ft_name;
1657
			dblk->ft.ft_name = NULL;
1658
			free(name);
1659
			break;
1660
		}
1661
	}
1662
}
1663
1664
/*
1665
 * proc_dir(int in_sig)
1666
 *	process all file modes and times stored for directories CREATED
1667
 *	by pax.  If in_sig is set, we're in a signal handler and can't
1668
 *	free stuff.
1669
 */
1670
1671
void
1672
proc_dir(int in_sig)
1673
{
1674
	DIRDATA *dblk;
1675
	size_t cnt;
1676
1677
12
	if (dirp == NULL)
1678
		return;
1679
	/*
1680
	 * read backwards through the file and process each directory
1681
	 */
1682
6
	cnt = dircnt;
1683
36
	while (cnt-- > 0) {
1684
12
		dblk = &dirp[cnt];
1685
		/*
1686
		 * If we remove a directory we created, we replace the
1687
		 * ft_name with NULL.  Ignore those.
1688
		 */
1689
12
		if (dblk->ft.ft_name == NULL)
1690
			continue;
1691
1692
		/*
1693
		 * frc_mode set, make sure we set the file modes even if
1694
		 * the user didn't ask for it (see file_subs.c for more info)
1695
		 */
1696
36
		set_attr(&dblk->ft, 0, dblk->mode, pmode || dblk->frc_mode,
1697
		    in_sig);
1698
12
		if (!in_sig)
1699
12
			free(dblk->ft.ft_name);
1700
	}
1701
1702
6
	if (!in_sig)
1703
6
		free(dirp);
1704
6
	dirp = NULL;
1705
6
	dircnt = 0;
1706
12
}
1707
1708
/*
1709
 * database independent routines
1710
 */
1711
1712
/*
1713
 * st_hash()
1714
 *	hashes filenames to a u_int for hashing into a table. Looks at the tail
1715
 *	end of file, as this provides far better distribution than any other
1716
 *	part of the name. For performance reasons we only care about the last
1717
 *	MAXKEYLEN chars (should be at LEAST large enough to pick off the file
1718
 *	name). Was tested on 500,000 name file tree traversal from the root
1719
 *	and gave almost a perfectly uniform distribution of keys when used with
1720
 *	prime sized tables (MAXKEYLEN was 128 in test). Hashes (sizeof int)
1721
 *	chars at a time and pads with 0 for last addition.
1722
 * Return:
1723
 *	the hash value of the string MOD (%) the table size.
1724
 */
1725
1726
u_int
1727
st_hash(const char *name, int len, int tabsz)
1728
{
1729
	const char *pt;
1730
	char *dest;
1731
	const char *end;
1732
	int i;
1733
	u_int key = 0;
1734
	int steps;
1735
	int res;
1736
1296
	u_int val;
1737
1738
	/*
1739
	 * only look at the tail up to MAXKEYLEN, we do not need to waste
1740
	 * time here (remember these are pathnames, the tail is what will
1741
	 * spread out the keys)
1742
	 */
1743
648
	if (len > MAXKEYLEN) {
1744
		pt = &(name[len - MAXKEYLEN]);
1745
		len = MAXKEYLEN;
1746
	} else
1747
		pt = name;
1748
1749
	/*
1750
	 * calculate the number of u_int size steps in the string and if
1751
	 * there is a runt to deal with
1752
	 */
1753
648
	steps = len/sizeof(u_int);
1754
648
	res = len % sizeof(u_int);
1755
1756
	/*
1757
	 * add up the value of the string in unsigned integer sized pieces
1758
	 * too bad we cannot have unsigned int aligned strings, then we
1759
	 * could avoid the expensive copy.
1760
	 */
1761
2592
	for (i = 0; i < steps; ++i) {
1762
648
		end = pt + sizeof(u_int);
1763
		dest = (char *)&val;
1764
6480
		while (pt < end)
1765
2592
			*dest++ = *pt++;
1766
648
		key += val;
1767
	}
1768
1769
	/*
1770
	 * add in the runt padded with zero to the right
1771
	 */
1772
648
	if (res) {
1773
24
		val = 0;
1774
24
		end = pt + res;
1775
		dest = (char *)&val;
1776
144
		while (pt < end)
1777
48
			*dest++ = *pt++;
1778
24
		key += val;
1779
24
	}
1780
1781
	/*
1782
	 * return the result mod the table size
1783
	 */
1784
1296
	return(key % tabsz);
1785
648
}