summaryrefslogtreecommitdiff
path: root/src/logic/tpax_archive_enqueue.c
blob: 7d8c27834c00b5d562ea94d4959db6479d055e13 (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
/**************************************************************/
/*  tpax: a topological pax implementation                    */
/*  Copyright (C) 2020--2024  SysDeer Technologies, LLC       */
/*  Released under GPLv2 and GPLv3; see COPYING.TPAX.         */
/**************************************************************/

#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <grp.h>
#include <pwd.h>
#include <sys/mman.h>
#include <sys/stat.h>

#include <tpax/tpax.h>
#include <tpax/tpax_specs.h>
#include "tpax_driver_impl.h"
#include "tpax_getdents_impl.h"
#include "tpax_readlink_impl.h"
#include "tpax_tmpfile_impl.h"
#include "tpax_errinfo_impl.h"

static char * tpax_add_prefix_item(
	const struct tpax_driver_ctx *  dctx,
	const char *                    prefix)
{
	struct tpax_driver_ctx_impl *   ictx;
	char **                         prefv;
	char **                         psrc;
	char **                         pdst;
	off_t                           elements;
	char *                          pitem;

	ictx = tpax_get_driver_ictx(dctx);

	for (psrc=ictx->prefixv; *psrc; psrc++)
		if (!strcmp(*psrc,prefix))
			return *psrc;

	if (ictx->prefixp == ictx->prefcap) {
		elements  = ictx->prefcap - ictx->prefixv;
		elements += 256;

		if (!(prefv = calloc(elements,sizeof(char *))))
			return 0;

		for (psrc=ictx->prefixv,pdst=prefv; *psrc; psrc++,pdst++)
			*pdst = *psrc;

		if (ictx->prefixv != ictx->prefptr)
			free(ictx->prefixv);

		ictx->prefixv = prefv;
		ictx->prefixp = pdst;
		ictx->prefcap = &prefv[--elements];
	}

	if (!(pitem = strdup(prefix)))
		return 0;

	*ictx->prefixp++ = pitem;

	return pitem;
}

static char * tpax_add_prefix_item_from_path(
	const struct tpax_driver_ctx *  dctx,
	const char *                    path,
	const char *                    mark)
{
	off_t   nbytes;
	char    pathbuf[PATH_MAX];

	if ((nbytes = (mark - path)) >= (PATH_MAX - 1))
		return 0;

	memcpy(pathbuf,path,nbytes);
	pathbuf[nbytes++] = '/';
	pathbuf[nbytes]   = '\0';

	return tpax_add_prefix_item(dctx,pathbuf);
}

static int tpax_dirent_init_from_stat(
	const struct stat * st,
	const char *        basename,
	struct dirent *     dirent)
{
	/* st_mode to d_type translation */
	if (S_ISREG(st->st_mode))
		dirent->d_type = DT_REG;
	else if (S_ISLNK(st->st_mode))
		dirent->d_type = DT_LNK;
	else if (S_ISDIR(st->st_mode))
		dirent->d_type = DT_DIR;
	else if (S_ISCHR(st->st_mode))
		dirent->d_type = DT_CHR;
	else if (S_ISBLK(st->st_mode))
		dirent->d_type = DT_CHR;
	else if (S_ISFIFO(st->st_mode))
		dirent->d_type = DT_CHR;
	else
		return -1;

	/* d_off, d_ino */
	dirent->d_off    = 0;
	dirent->d_ino    = st->st_ino;

	/* d_reclen */
	dirent->d_reclen  = offsetof(struct dirent,d_name);
	dirent->d_reclen += strlen(basename) + 1;

	dirent->d_reclen += 0x1;
	dirent->d_reclen |= 0x1;
	dirent->d_reclen ^= 0x1;

	/* d_name */
	strcpy(dirent->d_name,basename);

	return 0;
}

static struct tpax_dirent_buffer * tpax_dirent_buf_first_alloc(
	const struct tpax_driver_ctx * dctx)
{
	void * addr;
	struct tpax_driver_ctx_impl * ictx;

	addr = (struct tpax_dirent_buffer *)mmap(
		0,TPAX_DIRENT_BUFLEN,
		PROT_READ|PROT_WRITE,
		MAP_PRIVATE|MAP_ANONYMOUS,
		-1,0);

	if (addr == MAP_FAILED)
		return 0;

	ictx                  = tpax_get_driver_ictx(dctx);
	ictx->dirents         = (struct tpax_dirent_buffer *)addr;
	ictx->dirents->cdent  = ictx->dirents->dbuf;

	ictx->dirents->size   = TPAX_DIRENT_BUFLEN;
	ictx->dirents->next   = 0;

	ictx->dirents->nfree  = TPAX_DIRENT_BUFLEN;
	ictx->dirents->nfree -= offsetof(struct tpax_dirent_buffer,dbuf);

	return ictx->dirents;
}

static struct tpax_dirent_buffer * tpax_dirent_buf_next_alloc(
	struct tpax_dirent_buffer * current)
{
	void * addr;

	addr = (struct tpax_dirent_buffer *)mmap(
		0,TPAX_DIRENT_BUFLEN,
		PROT_READ|PROT_WRITE,
		MAP_PRIVATE|MAP_ANONYMOUS,
		-1,0);

	if (addr == MAP_FAILED)
		return 0;

	current->next         = (struct tpax_dirent_buffer *)addr;
	current->next->cdent  = current->next->dbuf;

	current->next->size   = TPAX_DIRENT_BUFLEN;
	current->next->next   = 0;

	current->next->nfree  = TPAX_DIRENT_BUFLEN;
	current->next->nfree -= offsetof(struct tpax_dirent_buffer,dbuf);

	return current->next;
}

static int tpax_archive_enqueue_ret(
	int                     ret,
	struct tpax_unit_ctx *  unit)
{
	if (unit)
		tpax_lib_free_unit_ctx(unit);

	return ret;
}

static int tpax_archive_add_queue_item(
	const struct tpax_driver_ctx *  dctx,
	const struct dirent *           dirent,
	const struct tpax_dirent *      parent,
	const char *                    prefix,
	dev_t                           srdev,
	dev_t                           stdev,
	ino_t                           stino,
	int                             depth,
	int                             flags,
	int                             fdat,
	bool *                          fkeep)
{
	struct tpax_dirent_buffer *     dentbuf;
	struct tpax_dirent *            cdent;
	const char *                    src;
	char *                          dst;
	char *                          cap;
	size_t                          needed;

	if (!(dentbuf = tpax_get_driver_dirents(dctx)))
		if (!(dentbuf = tpax_dirent_buf_first_alloc(dctx)))
			return tpax_archive_enqueue_ret(
				TPAX_SYSTEM_ERROR(dctx),
				0);

	needed  = dirent->d_reclen;
	needed += offsetof(struct tpax_dirent,dirent);
	needed += 0x7;
	needed |= 0x7;
	needed ^= 0x7;

	for (; dentbuf->next && (dentbuf->nfree < needed); )
		dentbuf = dentbuf->next;

	if (dentbuf->nfree < needed)
		if (!(dentbuf = tpax_dirent_buf_next_alloc(dentbuf)))
			return tpax_archive_enqueue_ret(
				TPAX_SYSTEM_ERROR(dctx),
				0);

	*fkeep        = true;
	cdent         = dentbuf->cdent;

	cdent->fdat   = fdat;
	cdent->depth  = depth;
	cdent->flags  = flags;
	cdent->stdev  = stdev;
	cdent->stino  = stino;
	cdent->nsize  = needed;
	cdent->parent = parent;
	cdent->prefix = prefix;

	switch (dirent->d_type) {
		case DT_CHR:
		case DT_BLK:
			cdent->srdev = srdev;
			break;

		default:
			cdent->srdev = 0777777;
	}

	memset(&cdent->dirent,0,offsetof(struct dirent,d_name));

	cdent->dirent.d_ino    = dirent->d_ino;
	cdent->dirent.d_type   = dirent->d_type;
	cdent->dirent.d_reclen = dirent->d_reclen;

	src  = dirent->d_name;
	dst  = cdent->dirent.d_name;

	cap  = dst - offsetof(struct dirent,d_name);
	cap -= offsetof(struct tpax_dirent,dirent);
	cap += needed;

	for (; *src; )
		*dst++ = *src++;

	for (; dst<cap; )
		*dst++ = 0;

	dentbuf->cdent  = (struct tpax_dirent *)cap;
	dentbuf->nfree -= needed;

	tpax_set_driver_dirmark(dctx,cdent);

	return 0;
}

static int tpax_archive_enqueue_dir_entries(
	const struct tpax_driver_ctx *  dctx,
	struct tpax_dirent *            dent)
{
	int                             fd;
	int                             fdat;
	int                             fdlnk;
	int                             depth;
	bool                            fkeep;
	bool                            flinks;
	bool                            fstdev;
	long                            nbytes;
	struct dirent *                 lnkent;
	struct dirent *                 dirent;
	struct dirent *                 dirents;
	struct tpax_dirent *            cdent;
	struct tpax_unit_ctx *          uctx;
	struct stat                     st;
	struct stat                     lnkst;
	uintptr_t                       addr;
	char                            lnktgt[PATH_MAX];
	char                            lnkbuf[PATH_MAX + sizeof(struct dirent)];

	/* init */
	fdat  = dent->fdat;
	depth = dent->depth;

	/* uctx on the fly */
	if (tpax_lib_get_unit_ctx(
			dctx,fdat,
			dent->dirent.d_name,
			&uctx) < 0)
		return TPAX_NESTED_ERROR(dctx);

	/* verify that recursion item is still a directory */
	if (!S_ISDIR(uctx->st->st_mode))
		return tpax_archive_enqueue_ret(
			TPAX_CUSTOM_ERROR(dctx,TPAX_ERR_FLOW_ERROR),
			uctx);

	/* ensure physical device identity as needed */
	if (dctx->cctx->drvflags & TPAX_DRIVER_STRICT_DEVICE_ID)
		if (dent->parent && (uctx->st->st_dev != dent->parent->stdev))
			return 0;

	/* obtain buffer for file-system directory entries */
	dirents = tpax_get_driver_getdents_buffer(dctx);
	dirent  = dirents;
	fkeep   = false;
	nbytes  = 0;
	depth++;

	/* open directory and obtain first directory entries */
	if ((fd = openat(fdat,dent->dirent.d_name,O_RDONLY|O_DIRECTORY|O_CLOEXEC,0)) < 0)
		return tpax_archive_enqueue_ret(
			TPAX_SYSTEM_ERROR(dctx),
			uctx);

	lnkent = (struct dirent *)lnkbuf;
	flinks = (dctx->cctx->drvflags & TPAX_DRIVER_PAX_SYMLINK_ITEMS);
	fstdev = (dctx->cctx->drvflags & TPAX_DRIVER_STRICT_DEVICE_ID);
	nbytes = tpax_getdents(fd,dirents,TPAX_DIRENT_BUFLEN);

	/* debugging, struct stat initialization when fstdev is false */
	memset(&st,0,sizeof(st));

	while ((nbytes == -EINTR) || ((nbytes < 0) && (errno == EINTR)))
		nbytes = tpax_getdents(fd,dirents,TPAX_DIRENT_BUFLEN);

	if (nbytes < 0)
		return tpax_archive_enqueue_ret(
			TPAX_SYSTEM_ERROR(dctx),
			uctx);

	/* iterate */
	for (; nbytes; ) {
		if (!strcmp(dirent->d_name,".")) {
			(void)0;

		} else if (!strcmp(dirent->d_name,"..")) {
			(void)0;

		} else {
			if (dirent->d_type == DT_UNKNOWN) {
				if (fstatat(fd,dirent->d_name,&st,AT_SYMLINK_NOFOLLOW))
					return tpax_archive_enqueue_ret(
						TPAX_SYSTEM_ERROR(dctx),
						uctx);

				if (S_ISDIR(st.st_mode)) {
					dirent->d_type = DT_DIR;
				}
			} else if (fstdev) {
				if (fstatat(fd,dirent->d_name,&st,AT_SYMLINK_NOFOLLOW))
					return tpax_archive_enqueue_ret(
						TPAX_SYSTEM_ERROR(dctx),
						uctx);
			}

			if (tpax_archive_add_queue_item(
					dctx,dirent,dent,0,
					st.st_rdev,
					st.st_dev,st.st_ino,
					depth,
					TPAX_ITEM_IMPLICIT,
					fd,&fkeep) < 0)
				return tpax_archive_enqueue_ret(
					TPAX_NESTED_ERROR(dctx),
					uctx);

			/* follow encountered symlink arguments as needed */
			fdlnk = (flinks && (dirent->d_type == DT_LNK))
				? openat(fd,dirent->d_name,O_RDONLY|O_CLOEXEC)
				: (-1);

			if (fdlnk >= 0) {
				if (fstat(fdlnk,&lnkst) <0) {
					close(fdlnk);
					return tpax_archive_enqueue_ret(
						TPAX_SYSTEM_ERROR(dctx),
						uctx);
				}

				if (tpax_readlinkat(fd,dirent->d_name,lnktgt,PATH_MAX) < 0)
					return tpax_archive_enqueue_ret(
						TPAX_SYSTEM_ERROR(dctx),
						uctx);

				close(fdlnk);

				if (tpax_dirent_init_from_stat(&lnkst,lnktgt,lnkent) < 0)
					return tpax_archive_enqueue_ret(
						TPAX_CUSTOM_ERROR(
							dctx,
							TPAX_ERR_FLOW_ERROR),
						0);

				cdent = tpax_get_driver_dirmark(dctx);
				cdent->flags |= TPAX_ITEM_NAMEREF;

				if (tpax_archive_add_queue_item(
						dctx,lnkent,cdent,0,
						lnkst.st_rdev,
						lnkst.st_dev,lnkst.st_ino,
						depth+1,
						TPAX_ITEM_IMPLICIT|TPAX_ITEM_SYMLINK,
						fd,&fkeep) < 0)
					return tpax_archive_enqueue_ret(
						TPAX_NESTED_ERROR(dctx),
						0);
			}
		}

		addr    = (uintptr_t)dirent;
		addr   += dirent->d_reclen;
		nbytes -= dirent->d_reclen;
		dirent  = (struct dirent *)addr;

		if (nbytes == 0) {
			nbytes = tpax_getdents(fd,dirents,TPAX_DIRENT_BUFLEN);

			while ((nbytes == -EINTR) || ((nbytes < 0) && (errno == EINTR)))
				nbytes = tpax_getdents(fd,dirents,TPAX_DIRENT_BUFLEN);

			if (nbytes < 0)
				tpax_archive_enqueue_ret(
					TPAX_SYSTEM_ERROR(dctx),
					uctx);

			dirent = dirents;
		}
	}

	/* all done */
	return tpax_archive_enqueue_ret(
		fkeep ? 0 : close(fd),
		uctx);
}

static const char * tpax_path_prefix_mark(const char * path)
{
	const char *    src;
	char *          mark;
	char            pathbuf[PATH_MAX];

	src  = path;
	mark = pathbuf;

	for (; *src; )
		*mark++ = *src++;

	for (--mark; (*mark == '/'); mark--)
		(void)0;

	*++mark = '\0';

	for (; (mark > pathbuf) && (mark[-1] != '/'); )
		mark--;

	return (mark <= pathbuf) ? 0 : &path[--mark-pathbuf];
}

int tpax_archive_enqueue(
	const struct tpax_driver_ctx *  dctx,
	const struct tpax_unit_ctx *    uctx)
{
	int                             fdat;
	int                             fdlnk;
	uintptr_t                       addr;
	const char *                    name;
	const char *                    mark;
	const char *                    prefix;
	bool                            fkeep;
	struct tpax_dirent_buffer *     dentbuf;
	struct tpax_dirent *            cdent;
	struct tpax_dirent *            cnext;
	struct dirent *                 dirent;
	struct dirent *                 lnkent;
	struct stat                     lnkst;
	char                            entbuf[PATH_MAX + sizeof(struct dirent)];
	char                            lnkbuf[PATH_MAX + sizeof(struct dirent)];

	/* init */
	fdat   = tpax_driver_fdcwd(dctx);
	dirent = (struct dirent *)entbuf;
	lnkent = (struct dirent *)lnkbuf;
	prefix = 0;

	/* split path to prefix + basename */
	if ((mark = tpax_path_prefix_mark(*uctx->path)))
		if (!(prefix = tpax_add_prefix_item_from_path(
				dctx,*uctx->path,mark)))
			return tpax_archive_enqueue_ret(
				TPAX_BUFFER_ERROR(dctx),
				0);

	name = mark ? ++mark : *uctx->path;

	if (prefix)
		if ((fdat = openat(fdat,prefix,O_RDONLY|O_DIRECTORY|O_CLOEXEC,0)) < 0)
			return tpax_archive_enqueue_ret(
				TPAX_SYSTEM_ERROR(dctx),
				0);

	/* explicit item directory entry */
	if (tpax_dirent_init_from_stat(uctx->st,name,dirent) < 0)
			return tpax_archive_enqueue_ret(
				TPAX_CUSTOM_ERROR(
					dctx,
					TPAX_ERR_FLOW_ERROR),
				0);

	/* add to queue */
	if (tpax_archive_add_queue_item(
			dctx,dirent,0,prefix,
			uctx->st->st_rdev,
			uctx->st->st_dev,
			uctx->st->st_ino,0,
			TPAX_ITEM_EXPLICIT,
			fdat,&fkeep) < 0)
		return tpax_archive_enqueue_ret(
			TPAX_NESTED_ERROR(dctx),
			0);

	/* follow command-line symlink arguments as needed */
	fdlnk = (uctx->link[0] && (dctx->cctx->drvflags & TPAX_DRIVER_PAX_SYMLINK_ARGS))
		? openat(fdat,uctx->link[0],O_RDONLY|O_CLOEXEC) : (-1);

	if (fdlnk >= 0) {
		if (fstat(fdlnk,&lnkst) <0) {
			close(fdlnk);
			return tpax_archive_enqueue_ret(
				TPAX_SYSTEM_ERROR(dctx),
				0);
		}

		close(fdlnk);

		if (tpax_dirent_init_from_stat(&lnkst,uctx->link[0],lnkent) < 0)
			return tpax_archive_enqueue_ret(
				TPAX_CUSTOM_ERROR(
					dctx,
					TPAX_ERR_FLOW_ERROR),
				0);

		cdent = tpax_get_driver_dirmark(dctx);
		cdent->flags |= TPAX_ITEM_NAMEREF;

		if (tpax_archive_add_queue_item(
				dctx,lnkent,cdent,0,
				lnkst.st_rdev,
				lnkst.st_dev,lnkst.st_ino,
				1,
				TPAX_ITEM_EXPLICIT|TPAX_ITEM_SYMLINK,
				fdat,&fkeep) < 0)
			return tpax_archive_enqueue_ret(
				TPAX_NESTED_ERROR(dctx),
				0);
	}

	/* queue directory child items */
	dentbuf = tpax_get_driver_dirents(dctx);
	cdent   = tpax_get_driver_dirmark(dctx);

	for (; cdent; ) {
		if (cdent->dirent.d_type == DT_DIR)
			if (dctx->cctx->drvflags & TPAX_DRIVER_DIR_MEMBER_RECURSE)
				if (tpax_archive_enqueue_dir_entries(dctx,cdent) < 0)
					return TPAX_NESTED_ERROR(dctx);

		addr  = (uintptr_t)cdent;
		addr += cdent->nsize;
		cnext = (struct tpax_dirent *)addr;

		if (cnext == dentbuf->cdent) {
			dentbuf = dentbuf->next;
			cnext   = dentbuf ? dentbuf->dbuf : 0;
		}

		cdent = cnext;
	}

	return 0;
}