summaryrefslogtreecommitdiffstats
path: root/lib/libalpm/util.c
blob: 81d950e8e5b7dd864856ab91028d0f2b48a2fd79 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
/*
 *  util.c
 *
 *  Copyright (c) 2006-2011 Pacman Development Team <pacman-dev@archlinux.org>
 *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
 *  Copyright (c) 2005 by Aurelien Foret <orelien@chez.com>
 *  Copyright (c) 2005 by Christian Hamar <krics@linuxforum.hu>
 *  Copyright (c) 2006 by David Kimpe <dnaku@frugalware.org>
 *  Copyright (c) 2005, 2006 by Miklos Vajna <vmiklos@frugalware.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 "config.h"

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <fcntl.h>
#include <unistd.h>
#include <ctype.h>
#include <dirent.h>
#include <time.h>
#include <syslog.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>

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

#ifdef HAVE_LIBSSL
#include <openssl/md5.h>
#else
#include "md5.h"
#endif

/* libalpm */
#include "util.h"
#include "log.h"
#include "package.h"
#include "alpm.h"
#include "alpm_list.h"
#include "handle.h"

#ifndef HAVE_STRSEP
/* This is a replacement for strsep which is not portable (missing on Solaris).
 * Copyright (c) 2001 by François Gouget <fgouget_at_codeweavers.com> */
char* strsep(char** str, const char* delims)
{
	char* token;

	if (*str==NULL) {
		/* No more tokens */
		return NULL;
	}

	token=*str;
	while (**str!='\0') {
		if (strchr(delims,**str)!=NULL) {
			**str='\0';
			(*str)++;
			return token;
		}
		(*str)++;
	}
	/* There is no other token */
	*str=NULL;
	return token;
}
#endif

int _alpm_makepath(const char *path)
{
	return(_alpm_makepath_mode(path, 0755));
}

/* does the same thing as 'mkdir -p' */
int _alpm_makepath_mode(const char *path, mode_t mode)
{
	/* A bit of pointer hell here. Descriptions:
	 * orig - a copy of path so we can safely butcher it with strsep
	 * str - the current position in the path string (after the delimiter)
	 * ptr - the original position of str after calling strsep
	 * incr - incrementally generated path for use in stat/mkdir call
	 */
	char *orig, *str, *ptr, *incr;
	mode_t oldmask = umask(0000);
	int ret = 0;

	orig = strdup(path);
	incr = calloc(strlen(orig) + 1, sizeof(char));
	str = orig;
	while((ptr = strsep(&str, "/"))) {
		if(strlen(ptr)) {
			/* we have another path component- append the newest component to
			 * existing string and create one more level of dir structure */
			strcat(incr, "/");
			strcat(incr, ptr);
			if(access(incr, F_OK)) {
				if(mkdir(incr, mode)) {
					ret = 1;
					break;
				}
			}
		}
	}
	free(orig);
	free(incr);
	umask(oldmask);
	return(ret);
}

#define CPBUFSIZE 8 * 1024

int _alpm_copyfile(const char *src, const char *dest)
{
	FILE *in, *out;
	size_t len;
	char *buf;
	int ret = 0;

	in = fopen(src, "rb");
	if(in == NULL) {
		return(1);
	}
	out = fopen(dest, "wb");
	if(out == NULL) {
		fclose(in);
		return(1);
	}

	CALLOC(buf, (size_t)CPBUFSIZE, (size_t)1, ret = 1; goto cleanup;);

	/* do the actual file copy */
	while((len = fread(buf, 1, CPBUFSIZE, in))) {
		size_t nwritten = 0;
		nwritten = fwrite(buf, 1, len, out);
		if((nwritten != len) || ferror(out)) {
			pm_errno = PM_ERR_WRITE;
			_alpm_log(PM_LOG_ERROR, _("error writing to file '%s': %s\n"),
					dest, strerror(errno));
			ret = -1;
			goto cleanup;
		}
	}

	/* chmod dest to permissions of src, as long as it is not a symlink */
	struct stat statbuf;
	if(!stat(src, &statbuf)) {
		if(! S_ISLNK(statbuf.st_mode)) {
			fchmod(fileno(out), statbuf.st_mode);
		}
	} else {
		/* stat was unsuccessful */
		ret = 1;
	}

cleanup:
	fclose(in);
	fclose(out);
	FREE(buf);
	return(ret);
}

/* Trim whitespace and newlines from a string
*/
char *_alpm_strtrim(char *str)
{
	char *pch = str;

	if(*str == '\0') {
		/* string is empty, so we're done. */
		return(str);
	}

	while(isspace((unsigned char)*pch)) {
		pch++;
	}
	if(pch != str) {
		memmove(str, pch, (strlen(pch) + 1));
	}

	/* check if there wasn't anything but whitespace in the string. */
	if(*str == '\0') {
		return(str);
	}

	pch = (str + (strlen(str) - 1));
	while(isspace((unsigned char)*pch)) {
		pch--;
	}
	*++pch = '\0';

	return(str);
}

/* Create a lock file */
int _alpm_lckmk()
{
	int fd;
	char *dir, *ptr;
	const char *file = alpm_option_get_lockfile();

	/* create the dir of the lockfile first */
	dir = strdup(file);
	ptr = strrchr(dir, '/');
	if(ptr) {
		*ptr = '\0';
	}
	_alpm_makepath(dir);
	FREE(dir);

	do {
		fd = open(file, O_WRONLY | O_CREAT | O_EXCL, 0000);
	} while (fd == -1 && errno == EINTR);
	if(fd > 0) {
		FILE *f = fdopen(fd, "w");
		fprintf(f, "%ld\n", (long)getpid());
		fflush(f);
		fsync(fd);
		fclose(f);
		return(fd);
	}
	return(-1);
}

/* Remove a lock file */
int _alpm_lckrm()
{
	const char *file = alpm_option_get_lockfile();
	if(unlink(file) == -1 && errno != ENOENT) {
		return(-1);
	}
	return(0);
}

/* Compression functions */

/**
 * @brief Unpack a specific file in an archive.
 *
 * @param archive  the archive to unpack
 * @param prefix   where to extract the files
 * @param fn       a file within the archive to unpack
 * @return 0 on success, 1 on failure
 */
int _alpm_unpack_single(const char *archive, const char *prefix, const char *fn)
{
	alpm_list_t *list = NULL;
	int ret = 0;
	if(fn == NULL) {
		return(1);
	}
	list = alpm_list_add(list, (void *)fn);
	ret = _alpm_unpack(archive, prefix, list, 1);
	alpm_list_free(list);
	return(ret);
}

/**
 * @brief Unpack a list of files in an archive.
 *
 * @param archive  the archive to unpack
 * @param prefix   where to extract the files
 * @param list     a list of files within the archive to unpack or
 * NULL for all
 * @param breakfirst break after the first entry found
 *
 * @return 0 on success, 1 on failure
 */
int _alpm_unpack(const char *archive, const char *prefix, alpm_list_t *list, int breakfirst)
{
	int ret = 0;
	mode_t oldmask;
	struct archive *_archive;
	struct archive_entry *entry;
	char cwd[PATH_MAX];
	int restore_cwd = 0;

	ALPM_LOG_FUNC;

	if((_archive = archive_read_new()) == NULL)
		RET_ERR(PM_ERR_LIBARCHIVE, 1);

	archive_read_support_compression_all(_archive);
	archive_read_support_format_all(_archive);

	if(archive_read_open_filename(_archive, archive,
				ARCHIVE_DEFAULT_BYTES_PER_BLOCK) != ARCHIVE_OK) {
		_alpm_log(PM_LOG_ERROR, _("could not open %s: %s\n"), archive,
				archive_error_string(_archive));
		RET_ERR(PM_ERR_PKG_OPEN, 1);
	}

	oldmask = umask(0022);

	/* save the cwd so we can restore it later */
	if(getcwd(cwd, PATH_MAX) == NULL) {
		_alpm_log(PM_LOG_ERROR, _("could not get current working directory\n"));
	} else {
		restore_cwd = 1;
	}

	/* just in case our cwd was removed in the upgrade operation */
	if(chdir(prefix) != 0) {
		_alpm_log(PM_LOG_ERROR, _("could not change directory to %s (%s)\n"), prefix, strerror(errno));
		ret = 1;
		goto cleanup;
	}

	while(archive_read_next_header(_archive, &entry) == ARCHIVE_OK) {
		const struct stat *st;
		const char *entryname; /* the name of the file in the archive */

		st = archive_entry_stat(entry);
		entryname = archive_entry_pathname(entry);

		if(S_ISREG(st->st_mode)) {
			archive_entry_set_perm(entry, 0644);
		} else if(S_ISDIR(st->st_mode)) {
			archive_entry_set_perm(entry, 0755);
		}

		/* If specific files were requested, skip entries that don't match. */
		if(list) {
			char *prefix = strdup(entryname);
			char *p = strstr(prefix,"/");
			if(p) {
				*(p+1) = '\0';
			}
			char *found = alpm_list_find_str(list, prefix);
			free(prefix);
			if(!found) {
				if (archive_read_data_skip(_archive) != ARCHIVE_OK) {
					ret = 1;
					goto cleanup;
				}
				continue;
			} else {
				_alpm_log(PM_LOG_DEBUG, "extracting: %s\n", entryname);
			}
		}

		/* Extract the archive entry. */
		int readret = archive_read_extract(_archive, entry, 0);
		if(readret == ARCHIVE_WARN) {
			/* operation succeeded but a non-critical error was encountered */
			_alpm_log(PM_LOG_WARNING, _("warning given while extracting %s (%s)\n"),
					entryname, archive_error_string(_archive));
		} else if(readret != ARCHIVE_OK) {
			_alpm_log(PM_LOG_ERROR, _("could not extract %s (%s)\n"),
					entryname, archive_error_string(_archive));
			ret = 1;
			goto cleanup;
		}

		if(breakfirst) {
			break;
		}
	}

cleanup:
	umask(oldmask);
	archive_read_finish(_archive);
	if(restore_cwd && chdir(cwd) != 0) {
		_alpm_log(PM_LOG_ERROR, _("could not change directory to %s (%s)\n"), cwd, strerror(errno));
	}
	return(ret);
}

/* does the same thing as 'rm -rf' */
int _alpm_rmrf(const char *path)
{
	int errflag = 0;
	struct dirent *dp;
	DIR *dirp;
	char name[PATH_MAX];
	struct stat st;

	if(_alpm_lstat(path, &st) == 0) {
		if(!S_ISDIR(st.st_mode)) {
			if(!unlink(path)) {
				return(0);
			} else {
				if(errno == ENOENT) {
					return(0);
				} else {
					return(1);
				}
			}
		} else {
			dirp = opendir(path);
			if(!dirp) {
				return(1);
			}
			for(dp = readdir(dirp); dp != NULL; dp = readdir(dirp)) {
				if(dp->d_ino) {
					sprintf(name, "%s/%s", path, dp->d_name);
					if(strcmp(dp->d_name, "..") != 0 && strcmp(dp->d_name, ".") != 0) {
						errflag += _alpm_rmrf(name);
					}
				}
			}
			closedir(dirp);
			if(rmdir(path)) {
				errflag++;
			}
		}
		return(errflag);
	}
	return(0);
}

int _alpm_logaction(int usesyslog, FILE *f, const char *fmt, va_list args)
{
	int ret = 0;

	if(usesyslog) {
		/* we can't use a va_list more than once, so we need to copy it
		 * so we can use the original when calling vfprintf below. */
		va_list args_syslog;
		va_copy(args_syslog, args);
		vsyslog(LOG_WARNING, fmt, args_syslog);
		va_end(args_syslog);
	}

	if(f) {
		time_t t;
		struct tm *tm;

		t = time(NULL);
		tm = localtime(&t);

		/* Use ISO-8601 date format */
		fprintf(f, "[%04d-%02d-%02d %02d:%02d] ",
						tm->tm_year+1900, tm->tm_mon+1, tm->tm_mday,
						tm->tm_hour, tm->tm_min);
		ret = vfprintf(f, fmt, args);
		fflush(f);
	}

	return(ret);
}

int _alpm_run_chroot(const char *root, const char *path, char *const argv[])
{
	char cwd[PATH_MAX];
	pid_t pid;
	int pipefd[2];
	int restore_cwd = 0;
	int retval = 0;

	ALPM_LOG_FUNC;

	/* save the cwd so we can restore it later */
	if(getcwd(cwd, PATH_MAX) == NULL) {
		_alpm_log(PM_LOG_ERROR, _("could not get current working directory\n"));
	} else {
		restore_cwd = 1;
	}

	/* just in case our cwd was removed in the upgrade operation */
	if(chdir(root) != 0) {
		_alpm_log(PM_LOG_ERROR, _("could not change directory to %s (%s)\n"), root, strerror(errno));
		goto cleanup;
	}

	_alpm_log(PM_LOG_DEBUG, "executing \"%s\" under chroot \"%s\"\n", path, root);

	/* Flush open fds before fork() to avoid cloning buffers */
	fflush(NULL);

	if(pipe(pipefd) == -1) {
		_alpm_log(PM_LOG_ERROR, _("could not create pipe (%s)\n"), strerror(errno));
		retval = 1;
		goto cleanup;
	}

	/* fork- parent and child each have seperate code blocks below */
	pid = fork();
	if(pid == -1) {
		_alpm_log(PM_LOG_ERROR, _("could not fork a new process (%s)\n"), strerror(errno));
		retval = 1;
		goto cleanup;
	}

	if(pid == 0) {
		/* this code runs for the child only (the actual chroot/exec) */
		close(1);
		close(2);
		while(dup2(pipefd[1], 1) == -1 && errno == EINTR);
		while(dup2(pipefd[1], 2) == -1 && errno == EINTR);
		close(pipefd[0]);
		close(pipefd[1]);

		/* use fprintf instead of _alpm_log to send output through the parent */
		if(chroot(root) != 0) {
			fprintf(stderr, _("could not change the root directory (%s)\n"), strerror(errno));
			exit(1);
		}
		if(chdir("/") != 0) {
			fprintf(stderr, _("could not change directory to / (%s)\n"), strerror(errno));
			exit(1);
		}
		umask(0022);
		execv(path, argv);
		fprintf(stderr, _("call to execv failed (%s)\n"), strerror(errno));
		exit(1);
	} else {
		/* this code runs for the parent only (wait on the child) */
		int status;
		FILE *pipe;

		close(pipefd[1]);
		pipe = fdopen(pipefd[0], "r");
		if(pipe == NULL) {
			close(pipefd[0]);
			retval = 1;
		} else {
			while(!feof(pipe)) {
				char line[PATH_MAX];
				if(fgets(line, PATH_MAX, pipe) == NULL)
					break;
				alpm_logaction("%s", line);
				EVENT(handle->trans, PM_TRANS_EVT_SCRIPTLET_INFO, line, NULL);
			}
			fclose(pipe);
		}

		while(waitpid(pid, &status, 0) == -1) {
			if(errno != EINTR) {
				_alpm_log(PM_LOG_ERROR, _("call to waitpid failed (%s)\n"), strerror(errno));
				retval = 1;
				goto cleanup;
			}
		}

		/* report error from above after the child has exited */
		if(retval != 0) {
			_alpm_log(PM_LOG_ERROR, _("could not open pipe (%s)\n"), strerror(errno));
			goto cleanup;
		}
		/* check the return status, make sure it is 0 (success) */
		if(WIFEXITED(status)) {
			_alpm_log(PM_LOG_DEBUG, "call to waitpid succeeded\n");
			if(WEXITSTATUS(status) != 0) {
				_alpm_log(PM_LOG_ERROR, _("command failed to execute correctly\n"));
				retval = 1;
			}
		}
	}

cleanup:
	if(restore_cwd && chdir(cwd) != 0) {
		_alpm_log(PM_LOG_ERROR, _("could not change directory to %s (%s)\n"), cwd, strerror(errno));
	}

	return(retval);
}

int _alpm_ldconfig(const char *root)
{
	char line[PATH_MAX];

	_alpm_log(PM_LOG_DEBUG, "running ldconfig\n");

	snprintf(line, PATH_MAX, "%setc/ld.so.conf", root);
	if(access(line, F_OK) == 0) {
		snprintf(line, PATH_MAX, "%ssbin/ldconfig", root);
		if(access(line, X_OK) == 0) {
			char *argv[] = { "ldconfig", NULL };
			_alpm_run_chroot(root, "/sbin/ldconfig", argv);
		}
	}

	return(0);
}

/* Helper function for comparing strings using the
 * alpm "compare func" signature */
int _alpm_str_cmp(const void *s1, const void *s2)
{
	return(strcmp(s1, s2));
}

/** Find a filename in a registered alpm cachedir.
 * @param filename name of file to find
 * @return malloced path of file, NULL if not found
 */
char *_alpm_filecache_find(const char* filename)
{
	char path[PATH_MAX];
	char *retpath;
	alpm_list_t *i;

	/* Loop through the cache dirs until we find a matching file */
	for(i = alpm_option_get_cachedirs(); i; i = alpm_list_next(i)) {
		snprintf(path, PATH_MAX, "%s%s", (char*)alpm_list_getdata(i),
				filename);
		if(access(path, R_OK) == 0) {
			retpath = strdup(path);
			_alpm_log(PM_LOG_DEBUG, "found cached pkg: %s\n", retpath);
			return(retpath);
		}
	}
	/* package wasn't found in any cachedir */
	return(NULL);
}

/** Check the alpm cachedirs for existance and find a writable one.
 * If no valid cache directory can be found, use /tmp.
 * @return pointer to a writable cache directory.
 */
const char *_alpm_filecache_setup(void)
{
	struct stat buf;
	alpm_list_t *i, *tmp;
	char *cachedir;

	/* Loop through the cache dirs until we find a writeable dir */
	for(i = alpm_option_get_cachedirs(); i; i = alpm_list_next(i)) {
		cachedir = alpm_list_getdata(i);
		if(stat(cachedir, &buf) != 0) {
			/* cache directory does not exist.... try creating it */
			_alpm_log(PM_LOG_WARNING, _("no %s cache exists, creating...\n"),
					cachedir);
			if(_alpm_makepath(cachedir) == 0) {
				_alpm_log(PM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
				return(cachedir);
			}
		} else if(S_ISDIR(buf.st_mode) && (buf.st_mode & S_IWUSR)) {
			_alpm_log(PM_LOG_DEBUG, "using cachedir: %s\n", cachedir);
			return(cachedir);
		}
	}

	/* we didn't find a valid cache directory. use /tmp. */
	tmp = alpm_list_add(NULL, strdup("/tmp/"));
	alpm_option_set_cachedirs(tmp);
	_alpm_log(PM_LOG_DEBUG, "using cachedir: %s", "/tmp/\n");
	_alpm_log(PM_LOG_WARNING, _("couldn't create package cache, using /tmp instead\n"));
	return(alpm_list_getdata(tmp));
}

/** lstat wrapper that treats /path/dirsymlink/ the same as /path/dirsymlink.
 * Linux lstat follows POSIX semantics and still performs a dereference on
 * the first, and for uses of lstat in libalpm this is not what we want.
 * @param path path to file to lstat
 * @param buf structure to fill with stat information
 * @return the return code from lstat
 */
int _alpm_lstat(const char *path, struct stat *buf)
{
	int ret;
	char *newpath = strdup(path);
	size_t len = strlen(newpath);

	/* strip the trailing slash if one exists */
	if(len != 0 && newpath[len - 1] == '/') {
			newpath[len - 1] = '\0';
	}

	ret = lstat(newpath, buf);

	FREE(newpath);
	return(ret);
}

#ifdef HAVE_LIBSSL
static int md5_file(const char *path, unsigned char output[16])
{
	FILE *f;
	size_t n;
	MD5_CTX ctx;
	unsigned char *buf;

	CALLOC(buf, 8192, sizeof(unsigned char), return(1));

	if((f = fopen(path, "rb")) == NULL) {
		free(buf);
		return(1);
	}

	MD5_Init(&ctx);

	while((n = fread(buf, 1, sizeof(buf), f)) > 0) {
		MD5_Update(&ctx, buf, n);
	}

	MD5_Final(output, &ctx);

	memset(&ctx, 0, sizeof(MD5_CTX));
	free(buf);

	if(ferror(f) != 0) {
		fclose(f);
		return(2);
	}

	fclose(f);
	return(0);
}
#endif

/** Get the md5 sum of file.
 * @param filename name of the file
 * @return the checksum on success, NULL on error
 * @addtogroup alpm_misc
 */
char SYMEXPORT *alpm_compute_md5sum(const char *filename)
{
	unsigned char output[16];
	char *md5sum;
	int ret, i;

	ALPM_LOG_FUNC;

	ASSERT(filename != NULL, return(NULL));

	/* allocate 32 chars plus 1 for null */
	md5sum = calloc(33, sizeof(char));
	/* defined above for OpenSSL, otherwise defined in md5.h */
	ret = md5_file(filename, output);

	if (ret > 0) {
		RET_ERR(PM_ERR_NOT_A_FILE, NULL);
	}

	/* Convert the result to something readable */
	for (i = 0; i < 16; i++) {
		/* sprintf is acceptable here because we know our output */
		sprintf(md5sum +(i * 2), "%02x", output[i]);
	}
	md5sum[32] = '\0';

	_alpm_log(PM_LOG_DEBUG, "md5(%s) = %s\n", filename, md5sum);
	return(md5sum);
}

int _alpm_test_md5sum(const char *filepath, const char *md5sum)
{
	char *md5sum2;
	int ret;

	md5sum2 = alpm_compute_md5sum(filepath);

	if(md5sum == NULL || md5sum2 == NULL) {
		ret = -1;
	} else if(strcmp(md5sum, md5sum2) != 0) {
		ret = 1;
	} else {
		ret = 0;
	}

	FREE(md5sum2);
	return(ret);
}

/* Note: does NOT handle sparse files on purpose for speed. */
int _alpm_archive_fgets(struct archive *a, struct archive_read_buffer *b)
{
	char *i = NULL;
	int64_t offset;
	int done = 0;

	while(1) {
		/* have we processed this entire block? */
		if(b->block + b->block_size == b->block_offset) {
			if(b->ret == ARCHIVE_EOF) {
				/* reached end of archive on the last read, now we are out of data */
				goto cleanup;
			}

			/* zero-copy - this is the entire next block of data. */
			b->ret = archive_read_data_block(a, (void*)&b->block,
					&b->block_size, &offset);
			b->block_offset = b->block;

			/* error or end of archive with no data read, cleanup */
			if(b->ret < ARCHIVE_OK ||
					(b->block_size == 0 && b->ret == ARCHIVE_EOF)) {
				goto cleanup;
			}
		}

		/* loop through the block looking for EOL characters */
		for(i = b->block_offset; i < (b->block + b->block_size); i++) {
			/* check if read value was null or newline */
			if(*i == '\0' || *i == '\n') {
				done = 1;
				break;
			}
		}

		/* allocate our buffer, or ensure our existing one is big enough */
		if(!b->line) {
			/* set the initial buffer to the read block_size */
			CALLOC(b->line, b->block_size + 1, sizeof(char),
					RET_ERR(PM_ERR_MEMORY, -1));
			b->line_size = b->block_size + 1;
			b->line_offset = b->line;
		} else {
			size_t needed = (size_t)((b->line_offset - b->line)
					+ (i - b->block_offset) + 1);
			if(needed > b->max_line_size) {
				RET_ERR(PM_ERR_MEMORY, -1);
			}
			if(needed > b->line_size) {
				/* need to realloc + copy data to fit total length */
				char *new;
				CALLOC(new, needed, sizeof(char), RET_ERR(PM_ERR_MEMORY, -1));
				memcpy(new, b->line, b->line_size);
				b->line_size = needed;
				b->line_offset = new + (b->line_offset - b->line);
				free(b->line);
				b->line = new;
			}
		}

		if(done) {
			size_t len = (size_t)(i - b->block_offset);
			memcpy(b->line_offset, b->block_offset, len);
			b->line_offset[len] = '\0';
			b->block_offset = ++i;
			/* this is the main return point; from here you can read b->line */
			return(ARCHIVE_OK);
		} else {
			/* we've looked through the whole block but no newline, copy it */
			size_t len = (size_t)(b->block + b->block_size - b->block_offset);
			memcpy(b->line_offset, b->block_offset, len);
			b->line_offset += len;
			b->block_offset = i;
		}
	}

cleanup:
	{
		int ret = b->ret;
		FREE(b->line);
		memset(b, 0, sizeof(b));
		return(ret);
	}
}

int _alpm_splitname(const char *target, pmpkg_t *pkg)
{
	/* the format of a db entry is as follows:
	 *    package-version-rel/
	 * package name can contain hyphens, so parse from the back- go back
	 * two hyphens and we have split the version from the name.
	 */
	char *tmp, *p, *q;

	if(target == NULL || pkg == NULL) {
		return(-1);
	}
	STRDUP(tmp, target, RET_ERR(PM_ERR_MEMORY, -1));
	p = tmp + strlen(tmp);

	/* remove any trailing '/' */
	while (*(p - 1) == '/') {
	  --p;
	  *p = '\0';
	}

	/* do the magic parsing- find the beginning of the version string
	 * by doing two iterations of same loop to lop off two hyphens */
	for(q = --p; *q && *q != '-'; q--);
	for(p = --q; *p && *p != '-'; p--);
	if(*p != '-' || p == tmp) {
		return(-1);
	}

	/* copy into fields and return */
	if(pkg->version) {
		FREE(pkg->version);
	}
	STRDUP(pkg->version, p+1, RET_ERR(PM_ERR_MEMORY, -1));
	/* insert a terminator at the end of the name (on hyphen)- then copy it */
	*p = '\0';
	if(pkg->name) {
		FREE(pkg->name);
	}
	STRDUP(pkg->name, tmp, RET_ERR(PM_ERR_MEMORY, -1));
	pkg->name_hash = _alpm_hash_sdbm(pkg->name);

	free(tmp);
	return(0);
}

/**
 * Hash the given string to an unsigned long value.
 * This is the standard sdbm hashing algorithm.
 * @param str string to hash
 * @return the hash value of the given string
 */
unsigned long _alpm_hash_sdbm(const char *str)
{
	unsigned long hash = 0;
	int c;

	if(!str) {
		return(hash);
	}
	while((c = *str++)) {
		hash = c + (hash << 6) + (hash << 16) - hash;
	}

	return(hash);
}

long _alpm_parsedate(const char *line)
{
	if(isalpha((unsigned char)line[0])) {
		/* initialize to null in case of failure */
		struct tm tmp_tm = { 0 };
		setlocale(LC_TIME, "C");
		strptime(line, "%a %b %e %H:%M:%S %Y", &tmp_tm);
		setlocale(LC_TIME, "");
		return(mktime(&tmp_tm));
	}
	return(atol(line));
}

#ifndef HAVE_STRNDUP
/* A quick and dirty implementation derived from glibc */
static size_t strnlen(const char *s, size_t max)
{
    register const char *p;
    for(p = s; *p && max--; ++p);
    return(p - s);
}

char *strndup(const char *s, size_t n)
{
  size_t len = strnlen(s, n);
  char *new = (char *) malloc(len + 1);

  if (new == NULL)
    return NULL;

  new[len] = '\0';
  return (char *) memcpy(new, s, len);
}
#endif

/* vim: set ts=2 sw=2 noet: */