summaryrefslogtreecommitdiff
path: root/util.c
blob: c367c794fb21ed2fe171a37d7b81f70dab0b57c7 (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
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
/*  -*- c-file-style: "linux" -*-
    
    Copyright (C) 1996-2000 by Andrew Tridgell 
    Copyright (C) Paul Mackerras 1996
   
   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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

/*
  Utilities used in rsync 

  tridge, June 1996
  */
#include "rsync.h"

extern int verbose;


/****************************************************************************
Set a fd into nonblocking mode
****************************************************************************/
void set_nonblocking(int fd)
{
	int val;

	if((val = fcntl(fd, F_GETFL, 0)) == -1)
		return;
	if (!(val & NONBLOCK_FLAG)) {
		val |= NONBLOCK_FLAG;
		fcntl(fd, F_SETFL, val);
	}
}

/****************************************************************************
Set a fd into blocking mode
****************************************************************************/
void set_blocking(int fd)
{
	int val;

	if((val = fcntl(fd, F_GETFL, 0)) == -1)
		return;
	if (val & NONBLOCK_FLAG) {
		val &= ~NONBLOCK_FLAG;
		fcntl(fd, F_SETFL, val);
	}
}


/* create a file descriptor pair - like pipe() but use socketpair if
   possible (because of blocking issues on pipes)

   always set non-blocking
 */
int fd_pair(int fd[2])
{
	int ret;

#if HAVE_SOCKETPAIR
	ret = socketpair(AF_UNIX, SOCK_STREAM, 0, fd);
#else
	ret = pipe(fd);
#endif

	if (ret == 0) {
		set_nonblocking(fd[0]);
		set_nonblocking(fd[1]);
	}
	
	return ret;
}


/* this is derived from CVS code 

   note that in the child STDIN is set to blocking and STDOUT
   is set to non-blocking. This is necessary as rsh relies on stdin being blocking
   and ssh relies on stdout being non-blocking

   if blocking_io is set then use blocking io on both fds. That can be
   used to cope with badly broken rsh implementations like the one on
   solaris.
 */
pid_t piped_child(char **command,int *f_in,int *f_out)
{
  pid_t pid;
  int to_child_pipe[2];
  int from_child_pipe[2];
  extern int blocking_io;

  if (fd_pair(to_child_pipe) < 0 ||
      fd_pair(from_child_pipe) < 0) {
    rprintf(FERROR,"pipe: %s\n",strerror(errno));
    exit_cleanup(RERR_IPC);
  }


  pid = do_fork();
  if (pid == -1) {
    rprintf(FERROR,"fork: %s\n",strerror(errno));
    exit_cleanup(RERR_IPC);
  }

  if (pid == 0)
    {
      extern int orig_umask;
      if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
	  close(to_child_pipe[1]) < 0 ||
	  close(from_child_pipe[0]) < 0 ||
	  dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
	rprintf(FERROR,"Failed to dup/close : %s\n",strerror(errno));
	exit_cleanup(RERR_IPC);
      }
      if (to_child_pipe[0] != STDIN_FILENO) close(to_child_pipe[0]);
      if (from_child_pipe[1] != STDOUT_FILENO) close(from_child_pipe[1]);
      umask(orig_umask);
      set_blocking(STDIN_FILENO);
      if (blocking_io) {
	set_blocking(STDOUT_FILENO);
      }
      execvp(command[0], command);
      rprintf(FERROR,"Failed to exec %s : %s\n",
	      command[0],strerror(errno));
      exit_cleanup(RERR_IPC);
    }

  if (close(from_child_pipe[1]) < 0 ||
      close(to_child_pipe[0]) < 0) {
    rprintf(FERROR,"Failed to close : %s\n",strerror(errno));   
    exit_cleanup(RERR_IPC);
  }

  *f_in = from_child_pipe[0];
  *f_out = to_child_pipe[1];

  return pid;
}

pid_t local_child(int argc, char **argv,int *f_in,int *f_out)
{
	pid_t pid;
	int to_child_pipe[2];
	int from_child_pipe[2];
	extern int read_batch;  /* dw */

	if (fd_pair(to_child_pipe) < 0 ||
	    fd_pair(from_child_pipe) < 0) {
		rprintf(FERROR,"pipe: %s\n",strerror(errno));
		exit_cleanup(RERR_IPC);
	}


	pid = do_fork();
	if (pid == -1) {
		rprintf(FERROR,"fork: %s\n",strerror(errno));
		exit_cleanup(RERR_IPC);
	}

	if (pid == 0) {
		extern int am_sender;
		extern int am_server;

		if (read_batch)
		    am_sender = 0;
		else
		    am_sender = !am_sender;
		am_server = 1;		

		if (dup2(to_child_pipe[0], STDIN_FILENO) < 0 ||
		    close(to_child_pipe[1]) < 0 ||
		    close(from_child_pipe[0]) < 0 ||
		    dup2(from_child_pipe[1], STDOUT_FILENO) < 0) {
			rprintf(FERROR,"Failed to dup/close : %s\n",strerror(errno));
			exit_cleanup(RERR_IPC);
		}
		if (to_child_pipe[0] != STDIN_FILENO) close(to_child_pipe[0]);
		if (from_child_pipe[1] != STDOUT_FILENO) close(from_child_pipe[1]);
		start_server(STDIN_FILENO, STDOUT_FILENO, argc, argv);
	}

	if (close(from_child_pipe[1]) < 0 ||
	    close(to_child_pipe[0]) < 0) {
		rprintf(FERROR,"Failed to close : %s\n",strerror(errno));   
		exit_cleanup(RERR_IPC);
	}

	*f_in = from_child_pipe[0];
	*f_out = to_child_pipe[1];
  
	return pid;
}



void out_of_memory(char *str)
{
  rprintf(FERROR,"ERROR: out of memory in %s\n",str);
  exit_cleanup(RERR_MALLOC);
}

void overflow(char *str)
{
  rprintf(FERROR,"ERROR: buffer overflow in %s\n",str);
  exit_cleanup(RERR_MALLOC);
}



int set_modtime(char *fname,time_t modtime)
{
	extern int dry_run;
	if (dry_run) return 0;
	{
#ifdef HAVE_UTIMBUF
		struct utimbuf tbuf;  
		tbuf.actime = time(NULL);
		tbuf.modtime = modtime;
		return utime(fname,&tbuf);
#elif defined(HAVE_UTIME)
		time_t t[2];
		t[0] = time(NULL);
		t[1] = modtime;
		return utime(fname,t);
#else
		struct timeval t[2];
		t[0].tv_sec = time(NULL);
		t[0].tv_usec = 0;
		t[1].tv_sec = modtime;
		t[1].tv_usec = 0;
		return utimes(fname,t);
#endif
	}
}


/****************************************************************************
create any necessary directories in fname. Unfortunately we don't know
what perms to give the directory when this is called so we need to rely
on the umask
****************************************************************************/
int create_directory_path(char *fname)
{
	extern int orig_umask;
	char *p;

	while (*fname == '/') fname++;
	while (strncmp(fname,"./",2)==0) fname += 2;

	p = fname;
	while ((p=strchr(p,'/'))) {
		*p = 0;
		do_mkdir(fname,0777 & ~orig_umask); 
		*p = '/';
		p++;
	}
	return 0;
}


/* Write LEN bytes at PTR to descriptor DESC, retrying if interrupted.
   Return LEN upon success, write's (negative) error code otherwise.  

   derived from GNU C's cccp.c.
*/
static int full_write(int desc, char *ptr, int len)
{
	int total_written;
	
	total_written = 0;
	while (len > 0) {
		int written = write (desc, ptr, len);
		if (written < 0)  {
#ifdef EINTR
			if (errno == EINTR)
				continue;
#endif
			return written;
		}
		total_written += written;
		ptr += written;
		len -= written;
	}
	return total_written;
}

/* Read LEN bytes at PTR from descriptor DESC, retrying if interrupted.
   Return the actual number of bytes read, zero for EOF, or negative
   for an error.  

   derived from GNU C's cccp.c. */
static int safe_read(int desc, char *ptr, int len)
{
	int n_chars;
 
	if (len <= 0)
		return len;
 
#ifdef EINTR
	do {
		n_chars = read(desc, ptr, len);
	} while (n_chars < 0 && errno == EINTR);
#else
	n_chars = read(desc, ptr, len);
#endif
 
	return n_chars;
}


/* copy a file - this is used in conjunction with the --temp-dir option */
int copy_file(char *source, char *dest, mode_t mode)
{
	int ifd;
	int ofd;
	char buf[1024 * 8];
	int len;   /* Number of bytes read into `buf'. */

	ifd = do_open(source, O_RDONLY, 0);
	if (ifd == -1) {
		rprintf(FERROR,"open %s: %s\n",
			source,strerror(errno));
		return -1;
	}

	if (robust_unlink(dest) && errno != ENOENT) {
		rprintf(FERROR,"unlink %s: %s\n",
			dest,strerror(errno));
		return -1;
	}

	ofd = do_open(dest, O_WRONLY | O_CREAT | O_TRUNC | O_EXCL, mode);
	if (ofd == -1) {
		rprintf(FERROR,"open %s: %s\n",
			dest,strerror(errno));
		close(ifd);
		return -1;
	}

	while ((len = safe_read(ifd, buf, sizeof(buf))) > 0) {
		if (full_write(ofd, buf, len) < 0) {
			rprintf(FERROR,"write %s: %s\n",
				dest,strerror(errno));
			close(ifd);
			close(ofd);
			return -1;
		}
	}

	close(ifd);
	close(ofd);

	if (len < 0) {
		rprintf(FERROR,"read %s: %s\n",
			source,strerror(errno));
		return -1;
	}

	return 0;
}

/*
  Robust unlink: some OS'es (HPUX) refuse to unlink busy files, so
  rename to <path>/.rsyncNNN instead. Note that successive rsync runs
  will shuffle the filenames around a bit as long as the file is still
  busy; this is because this function does not know if the unlink call
  is due to a new file coming in, or --delete trying to remove old
  .rsyncNNN files, hence it renames it each time.
*/
/* MAX_RENAMES should be 10**MAX_RENAMES_DIGITS */
#define MAX_RENAMES_DIGITS 3
#define MAX_RENAMES 1000

int robust_unlink(char *fname)
{
#ifndef ETXTBSY
	return do_unlink(fname);
#else
	static int counter = 1;
	int rc, pos, start;
	char path[MAXPATHLEN];

	rc = do_unlink(fname);
	if ((rc == 0) || (errno != ETXTBSY))
		return rc;

	strlcpy(path, fname, MAXPATHLEN);

	pos = strlen(path);
	while((path[--pos] != '/') && (pos >= 0))
		;
	++pos;
	strlcpy(&path[pos], ".rsync", MAXPATHLEN-pos);
	pos += sizeof(".rsync")-1;

	if (pos > (MAXPATHLEN-MAX_RENAMES_DIGITS-1)) {
		errno = ETXTBSY;
		return -1;
	}

	/* start where the last one left off to reduce chance of clashes */
	start = counter;
	do {
		sprintf(&path[pos], "%03d", counter);
		if (++counter >= MAX_RENAMES)
			counter = 1;
	} while (((rc = access(path, 0)) == 0) && (counter != start));

	if (verbose > 0)
		rprintf(FINFO,"renaming %s to %s because of text busy\n",
					    fname, path);

	/* maybe we should return rename()'s exit status? Nah. */
	if (do_rename(fname, path) != 0) {
		errno = ETXTBSY;
		return -1;
	}
	return 0;
#endif
}

int robust_rename(char *from, char *to)
{
#ifndef ETXTBSY
	return do_rename(from, to);
#else
	int rc = do_rename(from, to);
	if ((rc == 0) || (errno != ETXTBSY))
		return rc;
	if (robust_unlink(to) != 0)
		return -1;
	return do_rename(from, to);
#endif
}


static pid_t all_pids[10];
static int num_pids;

/* fork and record the pid of the child */
pid_t do_fork(void)
{
	pid_t newpid = fork();
	
	if (newpid) {
		all_pids[num_pids++] = newpid;
	}
	return newpid;
}

/* kill all children */
void kill_all(int sig)
{
	int i;
	for (i=0;i<num_pids;i++) {
		if (all_pids[i] != getpid())
			kill(all_pids[i], sig);
	}
}

/* turn a user name into a uid */
int name_to_uid(char *name, uid_t *uid)
{
	struct passwd *pass;
	if (!name || !*name) return 0;
	pass = getpwnam(name);
	if (pass) {
		*uid = pass->pw_uid;
		return 1;
	}
	return 0;
}

/* turn a group name into a gid */
int name_to_gid(char *name, gid_t *gid)
{
	struct group *grp;
	if (!name || !*name) return 0;
	grp = getgrnam(name);
	if (grp) {
		*gid = grp->gr_gid;
		return 1;
	}
	return 0;
}


/* lock a byte range in a open file */
int lock_range(int fd, int offset, int len)
{
	struct flock lock;

	lock.l_type = F_WRLCK;
	lock.l_whence = SEEK_SET;
	lock.l_start = offset;
	lock.l_len = len;
	lock.l_pid = 0;
	
	return fcntl(fd,F_SETLK,&lock) == 0;
}


static void glob_expand_one(char *s, char **argv, int *argc, int maxargs)
{
#if !(defined(HAVE_GLOB) && defined(HAVE_GLOB_H))
	if (!*s) s = ".";
	argv[*argc] = strdup(s);
	(*argc)++;
	return;
#else
	extern int sanitize_paths;
	glob_t globbuf;
	int i;

	if (!*s) s = ".";

	argv[*argc] = strdup(s);
	if (sanitize_paths) {
		sanitize_path(argv[*argc], NULL);
	}

	memset(&globbuf, 0, sizeof(globbuf));
	glob(argv[*argc], 0, NULL, &globbuf);
	if (globbuf.gl_pathc == 0) {
		(*argc)++;
		globfree(&globbuf);
		return;
	}
	for (i=0; i<(maxargs - (*argc)) && i<globbuf.gl_pathc;i++) {
		if (i == 0) free(argv[*argc]);
		argv[(*argc) + i] = strdup(globbuf.gl_pathv[i]);
		if (!argv[(*argc) + i]) out_of_memory("glob_expand");
	}
	globfree(&globbuf);
	(*argc) += i;
#endif
}

void glob_expand(char *base1, char **argv, int *argc, int maxargs)
{
	char *s = argv[*argc];
	char *p, *q;
	char *base = base1;

	if (!s || !*s) return;

	if (strncmp(s, base, strlen(base)) == 0) {
		s += strlen(base);
	}

	s = strdup(s);
	if (!s) out_of_memory("glob_expand");

	if (asprintf(&base," %s/", base1) <= 0) out_of_memory("glob_expand");

	q = s;
	while ((p = strstr(q,base)) && ((*argc) < maxargs)) {
		/* split it at this point */
		*p = 0;
		glob_expand_one(q, argv, argc, maxargs);
		q = p+strlen(base);
	}

	if (*q && (*argc < maxargs)) glob_expand_one(q, argv, argc, maxargs);

	free(s);
	free(base);
}

/*******************************************************************
  convert a string to lower case
********************************************************************/
void strlower(char *s)
{
	while (*s) {
		if (isupper(*s)) *s = tolower(*s);
		s++;
	}
}

void *Realloc(void *p, int size)
{
	if (!p) return (void *)malloc(size);
	return (void *)realloc(p, size);
}


void clean_fname(char *name)
{
	char *p;
	int l;
	int modified = 1;

	if (!name) return;

	while (modified) {
		modified = 0;

		if ((p=strstr(name,"/./"))) {
			modified = 1;
			while (*p) {
				p[0] = p[2];
				p++;
			}
		}

		if ((p=strstr(name,"//"))) {
			modified = 1;
			while (*p) {
				p[0] = p[1];
				p++;
			}
		}

		if (strncmp(p=name,"./",2) == 0) {      
			modified = 1;
			do {
				p[0] = p[2];
			} while (*p++);
		}

		l = strlen(p=name);
		if (l > 1 && p[l-1] == '/') {
			modified = 1;
			p[l-1] = 0;
		}
	}
}

/*
 * Make path appear as if a chroot had occurred:
 *    1. remove leading "/" (or replace with "." if at end)
 *    2. remove leading ".." components (except those allowed by "reldir")
 *    3. delete any other "<dir>/.." (recursively)
 * Can only shrink paths, so sanitizes in place.
 * While we're at it, remove double slashes and "." components like
 *   clean_fname does(), but DON'T remove a trailing slash because that
 *   is sometimes significant on command line arguments.
 * If "reldir" is non-null, it is a sanitized directory that the path will be
 *    relative to, so allow as many ".." at the beginning of the path as
 *    there are components in reldir.  This is used for symbolic link targets.
 *    If reldir is non-null and the path began with "/", to be completely like
 *    a chroot we should add in depth levels of ".." at the beginning of the
 *    path, but that would blow the assumption that the path doesn't grow and
 *    it is not likely to end up being a valid symlink anyway, so just do
 *    the normal removal of the leading "/" instead.
 * Contributed by Dave Dykstra <dwd@bell-labs.com>
 */

void sanitize_path(char *p, char *reldir)
{
	char *start, *sanp;
	int depth = 0;
	int allowdotdot = 0;

	if (reldir) {
		depth++;
		while (*reldir) {
			if (*reldir++ == '/') {
				depth++;
			}
		}
	}
	start = p;
	sanp = p;
	while (*p == '/') {
		/* remove leading slashes */
		p++;
	}
	while (*p != '\0') {
		/* this loop iterates once per filename component in p.
		 * both p (and sanp if the original had a slash) should
		 * always be left pointing after a slash
		 */
		if ((*p == '.') && ((*(p+1) == '/') || (*(p+1) == '\0'))) {
			/* skip "." component */
			while (*++p == '/') {
				/* skip following slashes */
				;
			}
			continue;
		}
		allowdotdot = 0;
		if ((*p == '.') && (*(p+1) == '.') &&
			    ((*(p+2) == '/') || (*(p+2) == '\0'))) {
			/* ".." component followed by slash or end */
			if ((depth > 0) && (sanp == start)) {
				/* allow depth levels of .. at the beginning */
				--depth;
				allowdotdot = 1;
			} else {
				p += 2;
				if (*p == '/')
					p++;
				if (sanp != start) {
					/* back up sanp one level */
					--sanp; /* now pointing at slash */
					while ((sanp > start) && (*(sanp - 1) != '/')) {
						/* skip back up to slash */
						sanp--;
					}
				}
				continue;
			}
		}
		while (1) {
			/* copy one component through next slash */
			*sanp++ = *p++;
			if ((*p == '\0') || (*(p-1) == '/')) {
				while (*p == '/') {
					/* skip multiple slashes */
					p++;
				}
				break;
			}
		}
		if (allowdotdot) {
			/* move the virtual beginning to leave the .. alone */
			start = sanp;
		}
	}
	if ((sanp == start) && !allowdotdot) {
		/* ended up with nothing, so put in "." component */
		/*
		 * note that the !allowdotdot doesn't prevent this from
		 *  happening in all allowed ".." situations, but I didn't
		 *  think it was worth putting in an extra variable to ensure
		 *  it since an extra "." won't hurt in those situations.
		 */
		*sanp++ = '.';
	}
	*sanp = '\0';
}


static char curr_dir[MAXPATHLEN];

/* like chdir() but can be reversed with pop_dir() if save is set. It
   is also much faster as it remembers where we have been */
char *push_dir(char *dir, int save)
{
	char *ret = curr_dir;
	static int initialised;

	if (!initialised) {
		initialised = 1;
		getcwd(curr_dir, sizeof(curr_dir)-1);
	}

	if (!dir) return NULL; /* this call was probably just to initialize */

	if (chdir(dir)) return NULL;

	if (save) {
		ret = strdup(curr_dir);
	}

	if (*dir == '/') {
		strlcpy(curr_dir, dir, sizeof(curr_dir));
	} else {
		strlcat(curr_dir,"/", sizeof(curr_dir));
		strlcat(curr_dir,dir, sizeof(curr_dir));
	}

	clean_fname(curr_dir);

	return ret;
}

/* reverse a push_dir call */
int pop_dir(char *dir)
{
	int ret;

	ret = chdir(dir);
	if (ret) {
		free(dir);
		return ret;
	}

	strlcpy(curr_dir, dir, sizeof(curr_dir));

	free(dir);

	return 0;
}

/* we need to supply our own strcmp function for file list comparisons
   to ensure that signed/unsigned usage is consistent between machines. */
int u_strcmp(const char *cs1, const char *cs2)
{
	const uchar *s1 = (const uchar *)cs1;
	const uchar *s2 = (const uchar *)cs2;

	while (*s1 && *s2 && (*s1 == *s2)) {
		s1++; s2++;
	}
	
	return (int)*s1 - (int)*s2;
}

static OFF_T last_ofs;

void end_progress(OFF_T size)
{
	extern int do_progress, am_server;

	if (do_progress && !am_server) {
		rprintf(FINFO,"%.0f (100%%)\n", (double)size);
	}
	last_ofs = 0;
}

void show_progress(OFF_T ofs, OFF_T size)
{
	extern int do_progress, am_server;

	if (do_progress && !am_server) {
		if (ofs > last_ofs + 1000) {
			int pct = (int)((100.0*ofs)/size);
			rprintf(FINFO,"%.0f (%d%%)\r", (double)ofs, pct);
			last_ofs = ofs;
		}
	}
}

/* determine if a symlink points outside the current directory tree */
int unsafe_symlink(char *dest, char *src)
{
	char *tok;
	int depth = 0;

	/* all absolute and null symlinks are unsafe */
	if (!dest || !(*dest) || (*dest == '/')) return 1;

	src = strdup(src);
	if (!src) out_of_memory("unsafe_symlink");

	/* find out what our safety margin is */
	for (tok=strtok(src,"/"); tok; tok=strtok(NULL,"/")) {
		if (strcmp(tok,"..") == 0) {
			depth=0;
		} else if (strcmp(tok,".") == 0) {
			/* nothing */
		} else {
			depth++;
		}
	}
	free(src);

	/* drop by one to account for the filename portion */
	depth--;

	dest = strdup(dest);
	if (!dest) out_of_memory("unsafe_symlink");

	for (tok=strtok(dest,"/"); tok; tok=strtok(NULL,"/")) {
		if (strcmp(tok,"..") == 0) {
			depth--;
		} else if (strcmp(tok,".") == 0) {
			/* nothing */
		} else {
			depth++;
		}
		/* if at any point we go outside the current directory then
		   stop - it is unsafe */
		if (depth < 0) break;
	}

	free(dest);
	return (depth < 0);
}


/****************************************************************************
  return the date and time as a string
****************************************************************************/
char *timestring(time_t t)
{
	static char TimeBuf[200];
	struct tm *tm = localtime(&t);

#ifdef HAVE_STRFTIME
	strftime(TimeBuf,sizeof(TimeBuf)-1,"%Y/%m/%d %T",tm);
#else
	strlcpy(TimeBuf, asctime(tm), sizeof(TimeBuf));
#endif

	if (TimeBuf[strlen(TimeBuf)-1] == '\n') {
		TimeBuf[strlen(TimeBuf)-1] = 0;
	}

	return(TimeBuf);
}


/*******************************************************************
sleep for a specified number of milliseconds
********************************************************************/
void msleep(int t)
{
	int tdiff=0;
	struct timeval tval,t1,t2;  

	gettimeofday(&t1, NULL);
	gettimeofday(&t2, NULL);
  
	while (tdiff < t) {
		tval.tv_sec = (t-tdiff)/1000;
		tval.tv_usec = 1000*((t-tdiff)%1000);
 
		errno = 0;
		select(0,NULL,NULL, NULL, &tval);

		gettimeofday(&t2, NULL);
		tdiff = (t2.tv_sec - t1.tv_sec)*1000 + 
			(t2.tv_usec - t1.tv_usec)/1000;
	}
}


/*******************************************************************
 Determine if two file modification times are equivalent (either exact 
 or in the modification timestamp window established by --modify-window) 
 Returns 0 if the times should be treated as the same, 1 if the 
 first is later and -1 if the 2nd is later
 *******************************************************************/
int cmp_modtime(time_t file1, time_t file2)
{
	extern int modify_window;

	if (file2 > file1) {
		if (file2 - file1 <= modify_window) return 0;
		return -1;
	}
	if (file1 - file2 <= modify_window) return 0;
	return 1;
}


#ifdef __INSURE__XX
#include <dlfcn.h>

/*******************************************************************
This routine is a trick to immediately catch errors when debugging
with insure. A xterm with a gdb is popped up when insure catches
a error. It is Linux specific.
********************************************************************/
int _Insure_trap_error(int a1, int a2, int a3, int a4, int a5, int a6)
{
	static int (*fn)();
	int ret;
	char *cmd;

	asprintf(&cmd, "/usr/X11R6/bin/xterm -display :0 -T Panic -n Panic -e /bin/sh -c 'cat /tmp/ierrs.*.%d ; gdb /proc/%d/exe %d'", 
		getpid(), getpid(), getpid());

	if (!fn) {
		static void *h;
		h = dlopen("/usr/local/parasoft/insure++lite/lib.linux2/libinsure.so", RTLD_LAZY);
		fn = dlsym(h, "_Insure_trap_error");
	}

	ret = fn(a1, a2, a3, a4, a5, a6);

	system(cmd);

	free(cmd);

	return ret;
}
#endif