summaryrefslogtreecommitdiff
path: root/lib/libalpm/be_sync.c
blob: 4a4be5482689d3c89c0b9cca6a7663544150ab4a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
/*
 *  be_sync.c : backend for sync databases
 *
 *  Copyright (c) 2006-2018 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <limits.h>
#include <unistd.h>

/* libarchive */
#include <archive.h>
#include <archive_entry.h>

/* libalpm */
#include "util.h"
#include "log.h"
#include "libarchive-compat.h"
#include "alpm.h"
#include "alpm_list.h"
#include "package.h"
#include "handle.h"
#include "delta.h"
#include "deps.h"
#include "dload.h"
#include "filelist.h"

static char *get_sync_dir(alpm_handle_t *handle)
{
	size_t len = strlen(handle->dbpath) + 6;
	char *syncpath;
	struct stat buf;

	MALLOC(syncpath, len, RET_ERR(handle, ALPM_ERR_MEMORY, NULL));
	sprintf(syncpath, "%s%s", handle->dbpath, "sync/");

	if(stat(syncpath, &buf) != 0) {
		_alpm_log(handle, ALPM_LOG_DEBUG, "database dir '%s' does not exist, creating it\n",
				syncpath);
		if(_alpm_makepath(syncpath) != 0) {
			free(syncpath);
			RET_ERR(handle, ALPM_ERR_SYSTEM, NULL);
		}
	} else if(!S_ISDIR(buf.st_mode)) {
		_alpm_log(handle, ALPM_LOG_WARNING, _("removing invalid file: %s\n"), syncpath);
		if(unlink(syncpath) != 0 || _alpm_makepath(syncpath) != 0) {
			free(syncpath);
			RET_ERR(handle, ALPM_ERR_SYSTEM, NULL);
		}
	}

	return syncpath;
}

static int sync_db_validate(alpm_db_t *db)
{
	int siglevel;
	const char *dbpath;

	if(db->status & DB_STATUS_VALID || db->status & DB_STATUS_MISSING) {
		return 0;
	}
	if(db->status & DB_STATUS_INVALID) {
		db->handle->pm_errno = ALPM_ERR_DB_INVALID_SIG;
		return -1;
	}

	dbpath = _alpm_db_path(db);
	if(!dbpath) {
		/* pm_errno set in _alpm_db_path() */
		return -1;
	}

	/* we can skip any validation if the database doesn't exist */
	if(_alpm_access(db->handle, NULL, dbpath, R_OK) != 0 && errno == ENOENT) {
		alpm_event_database_missing_t event = {
			.type = ALPM_EVENT_DATABASE_MISSING,
			.dbname = db->treename
		};
		db->status &= ~DB_STATUS_EXISTS;
		db->status |= DB_STATUS_MISSING;
		EVENT(db->handle, &event);
		goto valid;
	}
	db->status |= DB_STATUS_EXISTS;
	db->status &= ~DB_STATUS_MISSING;

	/* this takes into account the default verification level if UNKNOWN
	 * was assigned to this db */
	siglevel = alpm_db_get_siglevel(db);

	if(siglevel & ALPM_SIG_DATABASE) {
		int retry, ret;
		do {
			retry = 0;
			alpm_siglist_t *siglist;
			ret = _alpm_check_pgp_helper(db->handle, dbpath, NULL,
					siglevel & ALPM_SIG_DATABASE_OPTIONAL, siglevel & ALPM_SIG_DATABASE_MARGINAL_OK,
					siglevel & ALPM_SIG_DATABASE_UNKNOWN_OK, &siglist);
			if(ret) {
				retry = _alpm_process_siglist(db->handle, db->treename, siglist,
						siglevel & ALPM_SIG_DATABASE_OPTIONAL, siglevel & ALPM_SIG_DATABASE_MARGINAL_OK,
						siglevel & ALPM_SIG_DATABASE_UNKNOWN_OK);
			}
			alpm_siglist_cleanup(siglist);
			free(siglist);
		} while(retry);

		if(ret) {
			db->status &= ~DB_STATUS_VALID;
			db->status |= DB_STATUS_INVALID;
			db->handle->pm_errno = ALPM_ERR_DB_INVALID_SIG;
			return 1;
		}
	}

valid:
	db->status |= DB_STATUS_VALID;
	db->status &= ~DB_STATUS_INVALID;
	return 0;
}

/** Update a package database
 *
 * An update of the package database \a db will be attempted. Unless
 * \a force is true, the update will only be performed if the remote
 * database was modified since the last update.
 *
 * This operation requires a database lock, and will return an applicable error
 * if the lock could not be obtained.
 *
 * Example:
 * @code
 * alpm_list_t *syncs = alpm_get_syncdbs();
 * for(i = syncs; i; i = alpm_list_next(i)) {
 *     alpm_db_t *db = alpm_list_getdata(i);
 *     result = alpm_db_update(0, db);
 *
 *     if(result < 0) {
 *	       printf("Unable to update database: %s\n", alpm_strerrorlast());
 *     } else if(result == 1) {
 *         printf("Database already up to date\n");
 *     } else {
 *         printf("Database updated\n");
 *     }
 * }
 * @endcode
 *
 * @ingroup alpm_databases
 * @note After a successful update, the \link alpm_db_get_pkgcache()
 * package cache \endlink will be invalidated
 * @param force if true, then forces the update, otherwise update only in case
 * the database isn't up to date
 * @param db pointer to the package database to update
 * @return 0 on success, -1 on error (pm_errno is set accordingly), 1 if up to
 * to date
 */
int SYMEXPORT alpm_db_update(int force, alpm_db_t *db)
{
	char *syncpath;
	const char *dbext;
	alpm_list_t *i;
	int updated = 0;
	int ret = -1;
	mode_t oldmask;
	alpm_handle_t *handle;
	int siglevel;

	/* Sanity checks */
	ASSERT(db != NULL, return -1);
	handle = db->handle;
	handle->pm_errno = ALPM_ERR_OK;
	ASSERT(db != handle->db_local, RET_ERR(handle, ALPM_ERR_WRONG_ARGS, -1));
	ASSERT(db->servers != NULL, RET_ERR(handle, ALPM_ERR_SERVER_NONE, -1));

	if(!(db->usage & ALPM_DB_USAGE_SYNC)) {
		return 0;
	}

	syncpath = get_sync_dir(handle);
	if(!syncpath) {
		return -1;
	}

	/* force update of invalid databases to fix potential mismatched database/signature */
	if(db->status & DB_STATUS_INVALID) {
		force = 1;
	}

	/* make sure we have a sane umask */
	oldmask = umask(0022);

	siglevel = alpm_db_get_siglevel(db);

	/* attempt to grab a lock */
	if(_alpm_handle_lock(handle)) {
		free(syncpath);
		umask(oldmask);
		RET_ERR(handle, ALPM_ERR_HANDLE_LOCK, -1);
	}

	dbext = db->handle->dbext;

	for(i = db->servers; i; i = i->next) {
		const char *server = i->data, *final_db_url = NULL;
		struct dload_payload payload;
		size_t len;
		int sig_ret = 0;

		memset(&payload, 0, sizeof(struct dload_payload));

		/* set hard upper limit of 25MiB */
		payload.max_size = 25 * 1024 * 1024;

		/* print server + filename into a buffer */
		len = strlen(server) + strlen(db->treename) + strlen(dbext) + 2;
		MALLOC(payload.fileurl, len,
			{
				free(syncpath);
				umask(oldmask);
				RET_ERR(handle, ALPM_ERR_MEMORY, -1);
			}
		);
		snprintf(payload.fileurl, len, "%s/%s%s", server, db->treename, dbext);
		payload.handle = handle;
		payload.force = force;
		payload.unlink_on_fail = 1;

		ret = _alpm_download(&payload, syncpath, NULL, &final_db_url);
		_alpm_dload_payload_reset(&payload);
		updated = (updated || ret == 0);

		if(ret != -1 && updated && (siglevel & ALPM_SIG_DATABASE)) {
			/* an existing sig file is no good at this point */
			char *sigpath = _alpm_sigpath(handle, _alpm_db_path(db));
			if(!sigpath) {
				ret = -1;
				break;
			}
			unlink(sigpath);
			free(sigpath);


			/* check if the final URL from internal downloader looks reasonable */
			if(final_db_url != NULL) {
				if(strlen(final_db_url) < 3
						|| strcmp(final_db_url + strlen(final_db_url) - strlen(dbext),
								dbext) != 0) {
					final_db_url = NULL;
				}
			}

			/* if we downloaded a DB, we want the .sig from the same server */
			if(final_db_url != NULL) {
				/* print final_db_url into a buffer (leave space for .sig) */
				len = strlen(final_db_url) + 5;
			} else {
				/* print server + filename into a buffer (leave space for separator and .sig) */
				len = strlen(server) + strlen(db->treename) + strlen(dbext) + 6;
			}

			MALLOC(payload.fileurl, len,
				{
					free(syncpath);
					umask(oldmask);
					RET_ERR(handle, ALPM_ERR_MEMORY, -1);
				}
			);

			if(final_db_url != NULL) {
				snprintf(payload.fileurl, len, "%s.sig", final_db_url);
			} else {
				snprintf(payload.fileurl, len, "%s/%s%s.sig", server, db->treename, dbext);
			}

			payload.handle = handle;
			payload.force = 1;
			payload.errors_ok = (siglevel & ALPM_SIG_DATABASE_OPTIONAL);

			/* set hard upper limit of 16KiB */
			payload.max_size = 16 * 1024;

			sig_ret = _alpm_download(&payload, syncpath, NULL, NULL);
			/* errors_ok suppresses error messages, but not the return code */
			sig_ret = payload.errors_ok ? 0 : sig_ret;
			_alpm_dload_payload_reset(&payload);
		}

		if(ret != -1 && sig_ret != -1) {
			break;
		}
	}

	if(updated) {
		/* Cache needs to be rebuilt */
		_alpm_db_free_pkgcache(db);

		/* clear all status flags regarding validity/existence */
		db->status &= ~DB_STATUS_VALID;
		db->status &= ~DB_STATUS_INVALID;
		db->status &= ~DB_STATUS_EXISTS;
		db->status &= ~DB_STATUS_MISSING;

		/* if the download failed skip validation to preserve the download error */
		if(ret != -1 && sync_db_validate(db) != 0) {
			/* pm_errno should be set */
			ret = -1;
		}
	}

	if(ret == -1) {
		/* pm_errno was set by the download code */
		_alpm_log(handle, ALPM_LOG_DEBUG, "failed to sync db: %s\n",
				alpm_strerror(handle->pm_errno));
	} else {
		handle->pm_errno = ALPM_ERR_OK;
	}

	_alpm_handle_unlock(handle);
	free(syncpath);
	umask(oldmask);
	return ret;
}

/* Forward decl so I don't reorganize the whole file right now */
static int sync_db_read(alpm_db_t *db, struct archive *archive,
		struct archive_entry *entry, alpm_pkg_t **likely_pkg);

static int _sync_get_validation(alpm_pkg_t *pkg)
{
	if(pkg->validation) {
		return pkg->validation;
	}

	if(pkg->md5sum) {
		pkg->validation |= ALPM_PKG_VALIDATION_MD5SUM;
	}
	if(pkg->sha256sum) {
		pkg->validation |= ALPM_PKG_VALIDATION_SHA256SUM;
	}
	if(pkg->base64_sig) {
		pkg->validation |= ALPM_PKG_VALIDATION_SIGNATURE;
	}

	if(!pkg->validation) {
		pkg->validation |= ALPM_PKG_VALIDATION_NONE;
	}

	return pkg->validation;
}

static alpm_pkg_t *load_pkg_for_entry(alpm_db_t *db, const char *entryname,
		const char **entry_filename, alpm_pkg_t *likely_pkg)
{
	char *pkgname = NULL, *pkgver = NULL;
	unsigned long pkgname_hash;
	alpm_pkg_t *pkg;

	/* get package and db file names */
	if(entry_filename) {
		char *fname = strrchr(entryname, '/');
		if(fname) {
			*entry_filename = fname + 1;
		} else {
			*entry_filename = NULL;
		}
	}
	if(_alpm_splitname(entryname, &pkgname, &pkgver, &pkgname_hash) != 0) {
		_alpm_log(db->handle, ALPM_LOG_ERROR,
				_("invalid name for database entry '%s'\n"), entryname);
		return NULL;
	}

	if(likely_pkg && pkgname_hash == likely_pkg->name_hash
			&& strcmp(likely_pkg->name, pkgname) == 0) {
		pkg = likely_pkg;
	} else {
		pkg = _alpm_pkghash_find(db->pkgcache, pkgname);
	}
	if(pkg == NULL) {
		pkg = _alpm_pkg_new();
		if(pkg == NULL) {
			RET_ERR(db->handle, ALPM_ERR_MEMORY, NULL);
		}

		pkg->name = pkgname;
		pkg->version = pkgver;
		pkg->name_hash = pkgname_hash;

		pkg->origin = ALPM_PKG_FROM_SYNCDB;
		pkg->origin_data.db = db;
		pkg->ops = &default_pkg_ops;
		pkg->ops->get_validation = _sync_get_validation;
		pkg->handle = db->handle;

		/* add to the collection */
		_alpm_log(db->handle, ALPM_LOG_FUNCTION, "adding '%s' to package cache for db '%s'\n",
				pkg->name, db->treename);
		if(_alpm_pkghash_add(&db->pkgcache, pkg) == NULL) {
			_alpm_pkg_free(pkg);
			RET_ERR(db->handle, ALPM_ERR_MEMORY, NULL);
		}
	} else {
		free(pkgname);
		free(pkgver);
	}

	return pkg;
}

/* This function doesn't work as well as one might think, as size of database
 * entries varies considerably. Adding signatures nearly doubles the size of a
 * single entry; deltas also can make for large variations in size. These
 * current values are heavily influenced by Arch Linux; databases with no
 * deltas and a single signature per package. */
static size_t estimate_package_count(struct stat *st, struct archive *archive)
{
	int per_package;

	switch(_alpm_archive_filter_code(archive)) {
		case ARCHIVE_COMPRESSION_NONE:
			per_package = 3015;
			break;
		case ARCHIVE_COMPRESSION_GZIP:
		case ARCHIVE_COMPRESSION_COMPRESS:
			per_package = 464;
			break;
		case ARCHIVE_COMPRESSION_BZIP2:
			per_package = 394;
			break;
		case ARCHIVE_COMPRESSION_LZMA:
		case ARCHIVE_COMPRESSION_XZ:
			per_package = 400;
			break;
#ifdef ARCHIVE_COMPRESSION_UU
		case ARCHIVE_COMPRESSION_UU:
			per_package = 3015 * 4 / 3;
			break;
#endif
		default:
			/* assume it is at least somewhat compressed */
			per_package = 500;
	}

	return (size_t)((st->st_size / per_package) + 1);
}

static int sync_db_populate(alpm_db_t *db)
{
	const char *dbpath;
	size_t est_count, count;
	int fd;
	int ret = 0;
	int archive_ret;
	struct stat buf;
	struct archive *archive;
	struct archive_entry *entry;
	alpm_pkg_t *pkg = NULL;

	if(db->status & DB_STATUS_INVALID) {
		RET_ERR(db->handle, ALPM_ERR_DB_INVALID, -1);
	}
	if(db->status & DB_STATUS_MISSING) {
		RET_ERR(db->handle, ALPM_ERR_DB_NOT_FOUND, -1);
	}
	dbpath = _alpm_db_path(db);
	if(!dbpath) {
		/* pm_errno set in _alpm_db_path() */
		return -1;
	}

	fd = _alpm_open_archive(db->handle, dbpath, &buf,
			&archive, ALPM_ERR_DB_OPEN);
	if(fd < 0) {
		db->status &= ~DB_STATUS_VALID;
		db->status |= DB_STATUS_INVALID;
		return -1;
	}
	est_count = estimate_package_count(&buf, archive);

	/* currently only .files dbs contain file lists - make flexible when required*/
	if(strcmp(db->handle->dbext, ".files") == 0) {
		/* files databases are about four times larger on average */
		est_count /= 4;
	}

	db->pkgcache = _alpm_pkghash_create(est_count);
	if(db->pkgcache == NULL) {
		db->handle->pm_errno = ALPM_ERR_MEMORY;
		ret = -1;
		goto cleanup;
	}

	while((archive_ret = archive_read_next_header(archive, &entry)) == ARCHIVE_OK) {
		mode_t mode = archive_entry_mode(entry);
		if(!S_ISDIR(mode)) {
			/* we have desc, depends or deltas - parse it */
			if(sync_db_read(db, archive, entry, &pkg) != 0) {
				_alpm_log(db->handle, ALPM_LOG_ERROR,
						_("could not parse package description file '%s' from db '%s'\n"),
						archive_entry_pathname(entry), db->treename);
				ret = -1;
			}
		}
	}
	if(archive_ret != ARCHIVE_EOF) {
		_alpm_log(db->handle, ALPM_LOG_ERROR, _("could not read db '%s' (%s)\n"),
				db->treename, archive_error_string(archive));
		_alpm_db_free_pkgcache(db);
		db->handle->pm_errno = ALPM_ERR_LIBARCHIVE;
		ret = -1;
		goto cleanup;
	}

	count = alpm_list_count(db->pkgcache->list);
	if(count > 0) {
		db->pkgcache->list = alpm_list_msort(db->pkgcache->list,
				count, _alpm_pkg_cmp);
	}
	_alpm_log(db->handle, ALPM_LOG_DEBUG,
			"added %zu packages to package cache for db '%s'\n",
			count, db->treename);

cleanup:
	_alpm_archive_read_free(archive);
	if(fd >= 0) {
		close(fd);
	}
	return ret;
}

/* This function validates %FILENAME%. filename must be between 3 and
 * PATH_MAX characters and cannot be contain a path */
static int _alpm_validate_filename(alpm_db_t *db, const char *pkgname,
		const char *filename)
{
	size_t len = strlen(filename);

	if(filename[0] == '.') {
		errno = EINVAL;
		_alpm_log(db->handle, ALPM_LOG_ERROR, _("%s database is inconsistent: filename "
					"of package %s is illegal\n"), db->treename, pkgname);
		return -1;
	} else if(memchr(filename, '/', len) != NULL) {
		errno = EINVAL;
		_alpm_log(db->handle, ALPM_LOG_ERROR, _("%s database is inconsistent: filename "
					"of package %s is illegal\n"), db->treename, pkgname);
		return -1;
	} else if(len > PATH_MAX) {
		errno = EINVAL;
		_alpm_log(db->handle, ALPM_LOG_ERROR, _("%s database is inconsistent: filename "
					"of package %s is too long\n"), db->treename, pkgname);
		return -1;
	}

	return 0;
}

#define READ_NEXT() do { \
	if(_alpm_archive_fgets(archive, &buf) != ARCHIVE_OK) goto error; \
	line = buf.line; \
	_alpm_strip_newline(line, buf.real_line_size); \
} while(0)

#define READ_AND_STORE(f) do { \
	READ_NEXT(); \
	STRDUP(f, line, goto error); \
} while(0)

#define READ_AND_STORE_ALL(f) do { \
	char *linedup; \
	if(_alpm_archive_fgets(archive, &buf) != ARCHIVE_OK) goto error; \
	if(_alpm_strip_newline(buf.line, buf.real_line_size) == 0) break; \
	STRDUP(linedup, buf.line, goto error); \
	f = alpm_list_add(f, linedup); \
} while(1) /* note the while(1) and not (0) */

#define READ_AND_SPLITDEP(f) do { \
	if(_alpm_archive_fgets(archive, &buf) != ARCHIVE_OK) goto error; \
	if(_alpm_strip_newline(buf.line, buf.real_line_size) == 0) break; \
	f = alpm_list_add(f, alpm_dep_from_string(line)); \
} while(1) /* note the while(1) and not (0) */

static int sync_db_read(alpm_db_t *db, struct archive *archive,
		struct archive_entry *entry, alpm_pkg_t **likely_pkg)
{
	const char *entryname, *filename;
	alpm_pkg_t *pkg;
	struct archive_read_buffer buf;

	entryname = archive_entry_pathname(entry);
	if(entryname == NULL) {
		_alpm_log(db->handle, ALPM_LOG_DEBUG,
				"invalid archive entry provided to _alpm_sync_db_read, skipping\n");
		return -1;
	}

	_alpm_log(db->handle, ALPM_LOG_FUNCTION, "loading package data from archive entry %s\n",
			entryname);

	memset(&buf, 0, sizeof(buf));
	/* 512K for a line length seems reasonable */
	buf.max_line_size = 512 * 1024;

	pkg = load_pkg_for_entry(db, entryname, &filename, *likely_pkg);

	if(pkg == NULL) {
		_alpm_log(db->handle, ALPM_LOG_DEBUG,
				"entry %s could not be loaded into %s sync database\n",
				entryname, db->treename);
		return -1;
	}

	if(filename == NULL) {
		/* A file exists outside of a subdirectory. This isn't a read error, so return
		 * success and try to continue on. */
		_alpm_log(db->handle, ALPM_LOG_WARNING, _("unknown database file: %s\n"),
				entryname);
		return 0;
	}

	if(strcmp(filename, "desc") == 0 || strcmp(filename, "depends") == 0
			|| strcmp(filename, "files") == 0
			|| (strcmp(filename, "deltas") == 0 && db->handle->deltaratio > 0.0) ) {
		int ret;
		while((ret = _alpm_archive_fgets(archive, &buf)) == ARCHIVE_OK) {
			char *line = buf.line;
			if(_alpm_strip_newline(line, buf.real_line_size) == 0) {
				/* length of stripped line was zero */
				continue;
			}

			if(strcmp(line, "%NAME%") == 0) {
				READ_NEXT();
				if(strcmp(line, pkg->name) != 0) {
					_alpm_log(db->handle, ALPM_LOG_ERROR, _("%s database is inconsistent: name "
								"mismatch on package %s\n"), db->treename, pkg->name);
				}
			} else if(strcmp(line, "%VERSION%") == 0) {
				READ_NEXT();
				if(strcmp(line, pkg->version) != 0) {
					_alpm_log(db->handle, ALPM_LOG_ERROR, _("%s database is inconsistent: version "
								"mismatch on package %s\n"), db->treename, pkg->name);
				}
			} else if(strcmp(line, "%FILENAME%") == 0) {
				READ_AND_STORE(pkg->filename);
				if(_alpm_validate_filename(db, pkg->name, pkg->filename) < 0) {
					return -1;
				}
			} else if(strcmp(line, "%BASE%") == 0) {
				READ_AND_STORE(pkg->base);
			} else if(strcmp(line, "%DESC%") == 0) {
				READ_AND_STORE(pkg->desc);
			} else if(strcmp(line, "%GROUPS%") == 0) {
				READ_AND_STORE_ALL(pkg->groups);
			} else if(strcmp(line, "%URL%") == 0) {
				READ_AND_STORE(pkg->url);
			} else if(strcmp(line, "%LICENSE%") == 0) {
				READ_AND_STORE_ALL(pkg->licenses);
			} else if(strcmp(line, "%ARCH%") == 0) {
				READ_AND_STORE(pkg->arch);
			} else if(strcmp(line, "%BUILDDATE%") == 0) {
				READ_NEXT();
				pkg->builddate = _alpm_parsedate(line);
			} else if(strcmp(line, "%PACKAGER%") == 0) {
				READ_AND_STORE(pkg->packager);
			} else if(strcmp(line, "%CSIZE%") == 0) {
				READ_NEXT();
				pkg->size = _alpm_strtoofft(line);
			} else if(strcmp(line, "%ISIZE%") == 0) {
				READ_NEXT();
				pkg->isize = _alpm_strtoofft(line);
			} else if(strcmp(line, "%MD5SUM%") == 0) {
				READ_AND_STORE(pkg->md5sum);
			} else if(strcmp(line, "%SHA256SUM%") == 0) {
				READ_AND_STORE(pkg->sha256sum);
			} else if(strcmp(line, "%PGPSIG%") == 0) {
				READ_AND_STORE(pkg->base64_sig);
			} else if(strcmp(line, "%REPLACES%") == 0) {
				READ_AND_SPLITDEP(pkg->replaces);
			} else if(strcmp(line, "%DEPENDS%") == 0) {
				READ_AND_SPLITDEP(pkg->depends);
			} else if(strcmp(line, "%OPTDEPENDS%") == 0) {
				READ_AND_SPLITDEP(pkg->optdepends);
			} else if(strcmp(line, "%MAKEDEPENDS%") == 0) {
				/* currently unused */
				while(1) {
					READ_NEXT();
					if(strlen(line) == 0) break;
				}
			} else if(strcmp(line, "%CHECKDEPENDS%") == 0) {
				/* currently unused */
				while(1) {
					READ_NEXT();
					if(strlen(line) == 0) break;
				}
			} else if(strcmp(line, "%CONFLICTS%") == 0) {
				READ_AND_SPLITDEP(pkg->conflicts);
			} else if(strcmp(line, "%PROVIDES%") == 0) {
				READ_AND_SPLITDEP(pkg->provides);
			} else if(strcmp(line, "%DELTAS%") == 0) {
				/* Different than the rest because of the _alpm_delta_parse call. */
				while(1) {
					READ_NEXT();
					if(strlen(line) == 0) break;
					pkg->deltas = alpm_list_add(pkg->deltas,
							_alpm_delta_parse(db->handle, line));
				}
			} else if(strcmp(line, "%FILES%") == 0) {
				/* TODO: this could lazy load if there is future demand */
				size_t files_count = 0, files_size = 0;
				alpm_file_t *files = NULL;

				while(1) {
					if(_alpm_archive_fgets(archive, &buf) != ARCHIVE_OK) {
						goto error;
					}
					line = buf.line;
					if(_alpm_strip_newline(line, buf.real_line_size) == 0) {
						break;
					}

					if(!_alpm_greedy_grow((void **)&files, &files_size,
								(files_count ? (files_count + 1) * sizeof(alpm_file_t) : 8 * sizeof(alpm_file_t)))) {
						goto error;
					}
					STRDUP(files[files_count].name, line, goto error);
					files_count++;
				}
				/* attempt to hand back any memory we don't need */
				if(files_count > 0) {
					files = realloc(files, sizeof(alpm_file_t) * files_count);
				} else {
					FREE(files);
				}
				pkg->files.count = files_count;
				pkg->files.files = files;
				_alpm_filelist_sort(&pkg->files);
			}
		}
		if(ret != ARCHIVE_EOF) {
			goto error;
		}
		*likely_pkg = pkg;
	} else if(strcmp(filename, "deltas") == 0) {
		/* skip reading delta files if UseDelta is unset */
	} else {
		/* unknown database file */
		_alpm_log(db->handle, ALPM_LOG_DEBUG, "unknown database file: %s\n", filename);
	}

	return 0;

error:
	_alpm_log(db->handle, ALPM_LOG_DEBUG, "error parsing database file: %s\n", filename);
	return -1;
}

struct db_operations sync_db_ops = {
	.validate         = sync_db_validate,
	.populate         = sync_db_populate,
	.unregister       = _alpm_db_unregister,
};

alpm_db_t *_alpm_db_register_sync(alpm_handle_t *handle, const char *treename,
		int level)
{
	alpm_db_t *db;

	_alpm_log(handle, ALPM_LOG_DEBUG, "registering sync database '%s'\n", treename);

#ifndef HAVE_LIBGPGME
	if(level != 0 && level != ALPM_SIG_USE_DEFAULT) {
		RET_ERR(handle, ALPM_ERR_MISSING_CAPABILITY_SIGNATURES, NULL);
	}
#endif

	db = _alpm_db_new(treename, 0);
	if(db == NULL) {
		RET_ERR(handle, ALPM_ERR_DB_CREATE, NULL);
	}
	db->ops = &sync_db_ops;
	db->handle = handle;
	db->siglevel = level;

	sync_db_validate(db);

	handle->dbs_sync = alpm_list_add(handle->dbs_sync, db);
	return db;
}