xref: /freebsd/bin/pax/pat_rep.c (revision 2008043f386721d58158e37e0d7e50df8095942d)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1992 Keith Muller.
5  * Copyright (c) 1992, 1993
6  *	The Regents of the University of California.  All rights reserved.
7  *
8  * This code is derived from software contributed to Berkeley by
9  * Keith Muller of the University of California, San Diego.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 3. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #ifndef lint
37 #if 0
38 static char sccsid[] = "@(#)pat_rep.c	8.2 (Berkeley) 4/18/94";
39 #endif
40 #endif /* not lint */
41 #include <sys/cdefs.h>
42 #include <sys/types.h>
43 #include <sys/stat.h>
44 #include <stdio.h>
45 #include <string.h>
46 #include <stdlib.h>
47 #include <regex.h>
48 #include "pax.h"
49 #include "pat_rep.h"
50 #include "extern.h"
51 
52 /*
53  * routines to handle pattern matching, name modification (regular expression
54  * substitution and interactive renames), and destination name modification for
55  * copy (-rw). Both file name and link names are adjusted as required in these
56  * routines.
57  */
58 
59 #define MAXSUBEXP	10		/* max subexpressions, DO NOT CHANGE */
60 static PATTERN *pathead = NULL;		/* file pattern match list head */
61 static PATTERN *pattail = NULL;		/* file pattern match list tail */
62 static REPLACE *rephead = NULL;		/* replacement string list head */
63 static REPLACE *reptail = NULL;		/* replacement string list tail */
64 
65 static int rep_name(char *, int *, int);
66 static int tty_rename(ARCHD *);
67 static int fix_path(char *, int *, char *, int);
68 static int fn_match(char *, char *, char **);
69 static char * range_match(char *, int);
70 static int resub(regex_t *, regmatch_t *, char *, char *, char *, char *);
71 
72 /*
73  * rep_add()
74  *	parses the -s replacement string; compiles the regular expression
75  *	and stores the compiled value and it's replacement string together in
76  *	replacement string list. Input to this function is of the form:
77  *		/old/new/pg
78  *	The first char in the string specifies the delimiter used by this
79  *	replacement string. "Old" is a regular expression in "ed" format which
80  *	is compiled by regcomp() and is applied to filenames. "new" is the
81  *	substitution string; p and g are options flags for printing and global
82  *	replacement (over the single filename)
83  * Return:
84  *	0 if a proper replacement string and regular expression was added to
85  *	the list of replacement patterns; -1 otherwise.
86  */
87 
88 int
89 rep_add(char *str)
90 {
91 	char *pt1;
92 	char *pt2;
93 	REPLACE *rep;
94 	int res;
95 	char rebuf[BUFSIZ];
96 
97 	/*
98 	 * throw out the bad parameters
99 	 */
100 	if ((str == NULL) || (*str == '\0')) {
101 		paxwarn(1, "Empty replacement string");
102 		return(-1);
103 	}
104 
105 	/*
106 	 * first character in the string specifies what the delimiter is for
107 	 * this expression
108 	 */
109 	if ((pt1 = strchr(str+1, *str)) == NULL) {
110 		paxwarn(1, "Invalid replacement string %s", str);
111 		return(-1);
112 	}
113 
114 	/*
115 	 * allocate space for the node that handles this replacement pattern
116 	 * and split out the regular expression and try to compile it
117 	 */
118 	if ((rep = (REPLACE *)malloc(sizeof(REPLACE))) == NULL) {
119 		paxwarn(1, "Unable to allocate memory for replacement string");
120 		return(-1);
121 	}
122 
123 	*pt1 = '\0';
124 	if ((res = regcomp(&(rep->rcmp), str+1, 0)) != 0) {
125 		regerror(res, &(rep->rcmp), rebuf, sizeof(rebuf));
126 		paxwarn(1, "%s while compiling regular expression %s", rebuf, str);
127 		free(rep);
128 		return(-1);
129 	}
130 
131 	/*
132 	 * put the delimiter back in case we need an error message and
133 	 * locate the delimiter at the end of the replacement string
134 	 * we then point the node at the new substitution string
135 	 */
136 	*pt1++ = *str;
137 	if ((pt2 = strchr(pt1, *str)) == NULL) {
138 		regfree(&rep->rcmp);
139 		free(rep);
140 		paxwarn(1, "Invalid replacement string %s", str);
141 		return(-1);
142 	}
143 
144 	*pt2 = '\0';
145 	rep->nstr = pt1;
146 	pt1 = pt2++;
147 	rep->flgs = 0;
148 
149 	/*
150 	 * set the options if any
151 	 */
152 	while (*pt2 != '\0') {
153 		switch(*pt2) {
154 		case 'g':
155 		case 'G':
156 			rep->flgs  |= GLOB;
157 			break;
158 		case 'p':
159 		case 'P':
160 			rep->flgs  |= PRNT;
161 			break;
162 		default:
163 			regfree(&rep->rcmp);
164 			free(rep);
165 			*pt1 = *str;
166 			paxwarn(1, "Invalid replacement string option %s", str);
167 			return(-1);
168 		}
169 		++pt2;
170 	}
171 
172 	/*
173 	 * all done, link it in at the end
174 	 */
175 	rep->fow = NULL;
176 	if (rephead == NULL) {
177 		reptail = rephead = rep;
178 		return(0);
179 	}
180 	reptail->fow = rep;
181 	reptail = rep;
182 	return(0);
183 }
184 
185 /*
186  * pat_add()
187  *	add a pattern match to the pattern match list. Pattern matches are used
188  *	to select which archive members are extracted. (They appear as
189  *	arguments to pax in the list and read modes). If no patterns are
190  *	supplied to pax, all members in the archive will be selected (and the
191  *	pattern match list is empty).
192  * Return:
193  *	0 if the pattern was added to the list, -1 otherwise
194  */
195 
196 int
197 pat_add(char *str, char *chdnam)
198 {
199 	PATTERN *pt;
200 
201 	/*
202 	 * throw out the junk
203 	 */
204 	if ((str == NULL) || (*str == '\0')) {
205 		paxwarn(1, "Empty pattern string");
206 		return(-1);
207 	}
208 
209 	/*
210 	 * allocate space for the pattern and store the pattern. the pattern is
211 	 * part of argv so do not bother to copy it, just point at it. Add the
212 	 * node to the end of the pattern list
213 	 */
214 	if ((pt = (PATTERN *)malloc(sizeof(PATTERN))) == NULL) {
215 		paxwarn(1, "Unable to allocate memory for pattern string");
216 		return(-1);
217 	}
218 
219 	pt->pstr = str;
220 	pt->pend = NULL;
221 	pt->plen = strlen(str);
222 	pt->fow = NULL;
223 	pt->flgs = 0;
224 	pt->chdname = chdnam;
225 
226 	if (pathead == NULL) {
227 		pattail = pathead = pt;
228 		return(0);
229 	}
230 	pattail->fow = pt;
231 	pattail = pt;
232 	return(0);
233 }
234 
235 /*
236  * pat_chk()
237  *	complain if any the user supplied pattern did not result in a match to
238  *	a selected archive member.
239  */
240 
241 void
242 pat_chk(void)
243 {
244 	PATTERN *pt;
245 	int wban = 0;
246 
247 	/*
248 	 * walk down the list checking the flags to make sure MTCH was set,
249 	 * if not complain
250 	 */
251 	for (pt = pathead; pt != NULL; pt = pt->fow) {
252 		if (pt->flgs & MTCH)
253 			continue;
254 		if (!wban) {
255 			paxwarn(1, "WARNING! These patterns were not matched:");
256 			++wban;
257 		}
258 		(void)fprintf(stderr, "%s\n", pt->pstr);
259 	}
260 }
261 
262 /*
263  * pat_sel()
264  *	the archive member which matches a pattern was selected. Mark the
265  *	pattern as having selected an archive member. arcn->pat points at the
266  *	pattern that was matched. arcn->pat is set in pat_match()
267  *
268  *	NOTE: When the -c option is used, we are called when there was no match
269  *	by pat_match() (that means we did match before the inverted sense of
270  *	the logic). Now this seems really strange at first, but with -c  we
271  *	need to keep track of those patterns that cause an archive member to NOT
272  *	be selected (it found an archive member with a specified pattern)
273  * Return:
274  *	0 if the pattern pointed at by arcn->pat was tagged as creating a
275  *	match, -1 otherwise.
276  */
277 
278 int
279 pat_sel(ARCHD *arcn)
280 {
281 	PATTERN *pt;
282 	PATTERN **ppt;
283 	int len;
284 
285 	/*
286 	 * if no patterns just return
287 	 */
288 	if ((pathead == NULL) || ((pt = arcn->pat) == NULL))
289 		return(0);
290 
291 	/*
292 	 * when we are NOT limited to a single match per pattern mark the
293 	 * pattern and return
294 	 */
295 	if (!nflag) {
296 		pt->flgs |= MTCH;
297 		return(0);
298 	}
299 
300 	/*
301 	 * we reach this point only when we allow a single selected match per
302 	 * pattern, if the pattern matches a directory and we do not have -d
303 	 * (dflag) we are done with this pattern. We may also be handed a file
304 	 * in the subtree of a directory. in that case when we are operating
305 	 * with -d, this pattern was already selected and we are done
306 	 */
307 	if (pt->flgs & DIR_MTCH)
308 		return(0);
309 
310 	if (!dflag && ((pt->pend != NULL) || (arcn->type == PAX_DIR))) {
311 		/*
312 		 * ok we matched a directory and we are allowing
313 		 * subtree matches but because of the -n only its children will
314 		 * match. This is tagged as a DIR_MTCH type.
315 		 * WATCH IT, the code assumes that pt->pend points
316 		 * into arcn->name and arcn->name has not been modified.
317 		 * If not we will have a big mess. Yup this is another kludge
318 		 */
319 
320 		/*
321 		 * if this was a prefix match, remove trailing part of path
322 		 * so we can copy it. Future matches will be exact prefix match
323 		 */
324 		if (pt->pend != NULL)
325 			*pt->pend = '\0';
326 
327 		if ((pt->pstr = strdup(arcn->name)) == NULL) {
328 			paxwarn(1, "Pattern select out of memory");
329 			if (pt->pend != NULL)
330 				*pt->pend = '/';
331 			pt->pend = NULL;
332 			return(-1);
333 		}
334 
335 		/*
336 		 * put the trailing / back in the source string
337 		 */
338 		if (pt->pend != NULL) {
339 			*pt->pend = '/';
340 			pt->pend = NULL;
341 		}
342 		pt->plen = strlen(pt->pstr);
343 
344 		/*
345 		 * strip off any trailing /, this should really never happen
346 		 */
347 		len = pt->plen - 1;
348 		if (*(pt->pstr + len) == '/') {
349 			*(pt->pstr + len) = '\0';
350 			pt->plen = len;
351 		}
352 		pt->flgs = DIR_MTCH | MTCH;
353 		arcn->pat = pt;
354 		return(0);
355 	}
356 
357 	/*
358 	 * we are then done with this pattern, so we delete it from the list
359 	 * because it can never be used for another match.
360 	 * Seems kind of strange to do for a -c, but the pax spec is really
361 	 * vague on the interaction of -c -n and -d. We assume that when -c
362 	 * and the pattern rejects a member (i.e. it matched it) it is done.
363 	 * In effect we place the order of the flags as having -c last.
364 	 */
365 	pt = pathead;
366 	ppt = &pathead;
367 	while ((pt != NULL) && (pt != arcn->pat)) {
368 		ppt = &(pt->fow);
369 		pt = pt->fow;
370 	}
371 
372 	if (pt == NULL) {
373 		/*
374 		 * should never happen....
375 		 */
376 		paxwarn(1, "Pattern list inconsistent");
377 		return(-1);
378 	}
379 	*ppt = pt->fow;
380 	free(pt);
381 	arcn->pat = NULL;
382 	return(0);
383 }
384 
385 /*
386  * pat_match()
387  *	see if this archive member matches any supplied pattern, if a match
388  *	is found, arcn->pat is set to point at the potential pattern. Later if
389  *	this archive member is "selected" we process and mark the pattern as
390  *	one which matched a selected archive member (see pat_sel())
391  * Return:
392  *	0 if this archive member should be processed, 1 if it should be
393  *	skipped and -1 if we are done with all patterns (and pax should quit
394  *	looking for more members)
395  */
396 
397 int
398 pat_match(ARCHD *arcn)
399 {
400 	PATTERN *pt;
401 
402 	arcn->pat = NULL;
403 
404 	/*
405 	 * if there are no more patterns and we have -n (and not -c) we are
406 	 * done. otherwise with no patterns to match, matches all
407 	 */
408 	if (pathead == NULL) {
409 		if (nflag && !cflag)
410 			return(-1);
411 		return(0);
412 	}
413 
414 	/*
415 	 * have to search down the list one at a time looking for a match.
416 	 */
417 	pt = pathead;
418 	while (pt != NULL) {
419 		/*
420 		 * check for a file name match unless we have DIR_MTCH set in
421 		 * this pattern then we want a prefix match
422 		 */
423 		if (pt->flgs & DIR_MTCH) {
424 			/*
425 			 * this pattern was matched before to a directory
426 			 * as we must have -n set for this (but not -d). We can
427 			 * only match CHILDREN of that directory so we must use
428 			 * an exact prefix match (no wildcards).
429 			 */
430 			if ((arcn->name[pt->plen] == '/') &&
431 			    (strncmp(pt->pstr, arcn->name, pt->plen) == 0))
432 				break;
433 		} else if (fn_match(pt->pstr, arcn->name, &pt->pend) == 0)
434 			break;
435 		pt = pt->fow;
436 	}
437 
438 	/*
439 	 * return the result, remember that cflag (-c) inverts the sense of a
440 	 * match
441 	 */
442 	if (pt == NULL)
443 		return(cflag ? 0 : 1);
444 
445 	/*
446 	 * We had a match, now when we invert the sense (-c) we reject this
447 	 * member. However we have to tag the pattern a being successful, (in a
448 	 * match, not in selecting an archive member) so we call pat_sel() here.
449 	 */
450 	arcn->pat = pt;
451 	if (!cflag)
452 		return(0);
453 
454 	if (pat_sel(arcn) < 0)
455 		return(-1);
456 	arcn->pat = NULL;
457 	return(1);
458 }
459 
460 /*
461  * fn_match()
462  * Return:
463  *	0 if this archive member should be processed, 1 if it should be
464  *	skipped and -1 if we are done with all patterns (and pax should quit
465  *	looking for more members)
466  *	Note: *pend may be changed to show where the prefix ends.
467  */
468 
469 static int
470 fn_match(char *pattern, char *string, char **pend)
471 {
472 	char c;
473 	char test;
474 
475 	*pend = NULL;
476 	for (;;) {
477 		switch (c = *pattern++) {
478 		case '\0':
479 			/*
480 			 * Ok we found an exact match
481 			 */
482 			if (*string == '\0')
483 				return(0);
484 
485 			/*
486 			 * Check if it is a prefix match
487 			 */
488 			if ((dflag == 1) || (*string != '/'))
489 				return(-1);
490 
491 			/*
492 			 * It is a prefix match, remember where the trailing
493 			 * / is located
494 			 */
495 			*pend = string;
496 			return(0);
497 		case '?':
498 			if ((test = *string++) == '\0')
499 				return (-1);
500 			break;
501 		case '*':
502 			c = *pattern;
503 			/*
504 			 * Collapse multiple *'s.
505 			 */
506 			while (c == '*')
507 				c = *++pattern;
508 
509 			/*
510 			 * Optimized hack for pattern with a * at the end
511 			 */
512 			if (c == '\0')
513 				return (0);
514 
515 			/*
516 			 * General case, use recursion.
517 			 */
518 			while ((test = *string) != '\0') {
519 				if (!fn_match(pattern, string, pend))
520 					return (0);
521 				++string;
522 			}
523 			return (-1);
524 		case '[':
525 			/*
526 			 * range match
527 			 */
528 			if (((test = *string++) == '\0') ||
529 			    ((pattern = range_match(pattern, test)) == NULL))
530 				return (-1);
531 			break;
532 		case '\\':
533 		default:
534 			if (c != *string++)
535 				return (-1);
536 			break;
537 		}
538 	}
539 	/* NOTREACHED */
540 }
541 
542 static char *
543 range_match(char *pattern, int test)
544 {
545 	char c;
546 	char c2;
547 	int negate;
548 	int ok = 0;
549 
550 	if ((negate = (*pattern == '!')) != 0)
551 		++pattern;
552 
553 	while ((c = *pattern++) != ']') {
554 		/*
555 		 * Illegal pattern
556 		 */
557 		if (c == '\0')
558 			return (NULL);
559 
560 		if ((*pattern == '-') && ((c2 = pattern[1]) != '\0') &&
561 		    (c2 != ']')) {
562 			if ((c <= test) && (test <= c2))
563 				ok = 1;
564 			pattern += 2;
565 		} else if (c == test)
566 			ok = 1;
567 	}
568 	return (ok == negate ? NULL : pattern);
569 }
570 
571 /*
572  * mod_name()
573  *	modify a selected file name. first attempt to apply replacement string
574  *	expressions, then apply interactive file rename. We apply replacement
575  *	string expressions to both filenames and file links (if we didn't the
576  *	links would point to the wrong place, and we could never be able to
577  *	move an archive that has a file link in it). When we rename files
578  *	interactively, we store that mapping (old name to user input name) so
579  *	if we spot any file links to the old file name in the future, we will
580  *	know exactly how to fix the file link.
581  * Return:
582  *	0 continue to  process file, 1 skip this file, -1 pax is finished
583  */
584 
585 int
586 mod_name(ARCHD *arcn)
587 {
588 	int res = 0;
589 
590 	/*
591 	 * Strip off leading '/' if appropriate.
592 	 * Currently, this option is only set for the tar format.
593 	 */
594 	if (rmleadslash && arcn->name[0] == '/') {
595 		if (arcn->name[1] == '\0') {
596 			arcn->name[0] = '.';
597 		} else {
598 			(void)memmove(arcn->name, &arcn->name[1],
599 			    strlen(arcn->name));
600 			arcn->nlen--;
601 		}
602 		if (rmleadslash < 2) {
603 			rmleadslash = 2;
604 			paxwarn(0, "Removing leading / from absolute path names in the archive");
605 		}
606 	}
607 	if (rmleadslash && arcn->ln_name[0] == '/' &&
608 	    (arcn->type == PAX_HLK || arcn->type == PAX_HRG)) {
609 		if (arcn->ln_name[1] == '\0') {
610 			arcn->ln_name[0] = '.';
611 		} else {
612 			(void)memmove(arcn->ln_name, &arcn->ln_name[1],
613 			    strlen(arcn->ln_name));
614 			arcn->ln_nlen--;
615 		}
616 		if (rmleadslash < 2) {
617 			rmleadslash = 2;
618 			paxwarn(0, "Removing leading / from absolute path names in the archive");
619 		}
620 	}
621 
622 	/*
623 	 * IMPORTANT: We have a problem. what do we do with symlinks?
624 	 * Modifying a hard link name makes sense, as we know the file it
625 	 * points at should have been seen already in the archive (and if it
626 	 * wasn't seen because of a read error or a bad archive, we lose
627 	 * anyway). But there are no such requirements for symlinks. On one
628 	 * hand the symlink that refers to a file in the archive will have to
629 	 * be modified to so it will still work at its new location in the
630 	 * file system. On the other hand a symlink that points elsewhere (and
631 	 * should continue to do so) should not be modified. There is clearly
632 	 * no perfect solution here. So we handle them like hardlinks. Clearly
633 	 * a replacement made by the interactive rename mapping is very likely
634 	 * to be correct since it applies to a single file and is an exact
635 	 * match. The regular expression replacements are a little harder to
636 	 * justify though. We claim that the symlink name is only likely
637 	 * to be replaced when it points within the file tree being moved and
638 	 * in that case it should be modified. what we really need to do is to
639 	 * call an oracle here. :)
640 	 */
641 	if (rephead != NULL) {
642 		/*
643 		 * we have replacement strings, modify the name and the link
644 		 * name if any.
645 		 */
646 		if ((res = rep_name(arcn->name, &(arcn->nlen), 1)) != 0)
647 			return(res);
648 
649 		if (((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
650 		    (arcn->type == PAX_HRG)) &&
651 		    ((res = rep_name(arcn->ln_name, &(arcn->ln_nlen), 0)) != 0))
652 			return(res);
653 	}
654 
655 	if (iflag) {
656 		/*
657 		 * perform interactive file rename, then map the link if any
658 		 */
659 		if ((res = tty_rename(arcn)) != 0)
660 			return(res);
661 		if ((arcn->type == PAX_SLK) || (arcn->type == PAX_HLK) ||
662 		    (arcn->type == PAX_HRG))
663 			sub_name(arcn->ln_name, &(arcn->ln_nlen), sizeof(arcn->ln_name));
664 	}
665 	return(res);
666 }
667 
668 /*
669  * tty_rename()
670  *	Prompt the user for a replacement file name. A "." keeps the old name,
671  *	a empty line skips the file, and an EOF on reading the tty, will cause
672  *	pax to stop processing and exit. Otherwise the file name input, replaces
673  *	the old one.
674  * Return:
675  *	0 process this file, 1 skip this file, -1 we need to exit pax
676  */
677 
678 static int
679 tty_rename(ARCHD *arcn)
680 {
681 	char tmpname[PAXPATHLEN+2];
682 	int res;
683 
684 	/*
685 	 * prompt user for the replacement name for a file, keep trying until
686 	 * we get some reasonable input. Archives may have more than one file
687 	 * on them with the same name (from updates etc). We print verbose info
688 	 * on the file so the user knows what is up.
689 	 */
690 	tty_prnt("\nATTENTION: %s interactive file rename operation.\n", argv0);
691 
692 	for (;;) {
693 		ls_tty(arcn);
694 		tty_prnt("Input new name, or a \".\" to keep the old name, ");
695 		tty_prnt("or a \"return\" to skip this file.\n");
696 		tty_prnt("Input > ");
697 		if (tty_read(tmpname, sizeof(tmpname)) < 0)
698 			return(-1);
699 		if (strcmp(tmpname, "..") == 0) {
700 			tty_prnt("Try again, illegal file name: ..\n");
701 			continue;
702 		}
703 		if (strlen(tmpname) > PAXPATHLEN) {
704 			tty_prnt("Try again, file name too long\n");
705 			continue;
706 		}
707 		break;
708 	}
709 
710 	/*
711 	 * empty file name, skips this file. a "." leaves it alone
712 	 */
713 	if (tmpname[0] == '\0') {
714 		tty_prnt("Skipping file.\n");
715 		return(1);
716 	}
717 	if ((tmpname[0] == '.') && (tmpname[1] == '\0')) {
718 		tty_prnt("Processing continues, name unchanged.\n");
719 		return(0);
720 	}
721 
722 	/*
723 	 * ok the name changed. We may run into links that point at this
724 	 * file later. we have to remember where the user sent the file
725 	 * in order to repair any links.
726 	 */
727 	tty_prnt("Processing continues, name changed to: %s\n", tmpname);
728 	res = add_name(arcn->name, arcn->nlen, tmpname);
729 	arcn->nlen = l_strncpy(arcn->name, tmpname, sizeof(arcn->name) - 1);
730 	arcn->name[arcn->nlen] = '\0';
731 	if (res < 0)
732 		return(-1);
733 	return(0);
734 }
735 
736 /*
737  * set_dest()
738  *	fix up the file name and the link name (if any) so this file will land
739  *	in the destination directory (used during copy() -rw).
740  * Return:
741  *	0 if ok, -1 if failure (name too long)
742  */
743 
744 int
745 set_dest(ARCHD *arcn, char *dest_dir, int dir_len)
746 {
747 	if (fix_path(arcn->name, &(arcn->nlen), dest_dir, dir_len) < 0)
748 		return(-1);
749 
750 	/*
751 	 * It is really hard to deal with symlinks here, we cannot be sure
752 	 * if the name they point was moved (or will be moved). It is best to
753 	 * leave them alone.
754 	 */
755 	if ((arcn->type != PAX_HLK) && (arcn->type != PAX_HRG))
756 		return(0);
757 
758 	if (fix_path(arcn->ln_name, &(arcn->ln_nlen), dest_dir, dir_len) < 0)
759 		return(-1);
760 	return(0);
761 }
762 
763 /*
764  * fix_path
765  *	concatenate dir_name and or_name and store the result in or_name (if
766  *	it fits). This is one ugly function.
767  * Return:
768  *	0 if ok, -1 if the final name is too long
769  */
770 
771 static int
772 fix_path( char *or_name, int *or_len, char *dir_name, int dir_len)
773 {
774 	char *src;
775 	char *dest;
776 	char *start;
777 	int len;
778 
779 	/*
780 	 * we shift the or_name to the right enough to tack in the dir_name
781 	 * at the front. We make sure we have enough space for it all before
782 	 * we start. since dest always ends in a slash, we skip of or_name
783 	 * if it also starts with one.
784 	 */
785 	start = or_name;
786 	src = start + *or_len;
787 	dest = src + dir_len;
788 	if (*start == '/') {
789 		++start;
790 		--dest;
791 	}
792 	if ((len = dest - or_name) > PAXPATHLEN) {
793 		paxwarn(1, "File name %s/%s, too long", dir_name, start);
794 		return(-1);
795 	}
796 	*or_len = len;
797 
798 	/*
799 	 * enough space, shift
800 	 */
801 	while (src >= start)
802 		*dest-- = *src--;
803 	src = dir_name + dir_len - 1;
804 
805 	/*
806 	 * splice in the destination directory name
807 	 */
808 	while (src >= dir_name)
809 		*dest-- = *src--;
810 
811 	*(or_name + len) = '\0';
812 	return(0);
813 }
814 
815 /*
816  * rep_name()
817  *	walk down the list of replacement strings applying each one in order.
818  *	when we find one with a successful substitution, we modify the name
819  *	as specified. if required, we print the results. if the resulting name
820  *	is empty, we will skip this archive member. We use the regexp(3)
821  *	routines (regexp() ought to win a prize as having the most cryptic
822  *	library function manual page).
823  *	--Parameters--
824  *	name is the file name we are going to apply the regular expressions to
825  *	(and may be modified)
826  *	nlen is the length of this name (and is modified to hold the length of
827  *	the final string).
828  *	prnt is a flag that says whether to print the final result.
829  * Return:
830  *	0 if substitution was successful, 1 if we are to skip the file (the name
831  *	ended up empty)
832  */
833 
834 static int
835 rep_name(char *name, int *nlen, int prnt)
836 {
837 	REPLACE *pt;
838 	char *inpt;
839 	char *outpt;
840 	char *endpt;
841 	char *rpt;
842 	int found = 0;
843 	int res;
844 	regmatch_t pm[MAXSUBEXP];
845 	char nname[PAXPATHLEN+1];	/* final result of all replacements */
846 	char buf1[PAXPATHLEN+1];	/* where we work on the name */
847 
848 	/*
849 	 * copy the name into buf1, where we will work on it. We need to keep
850 	 * the orig string around so we can print out the result of the final
851 	 * replacement. We build up the final result in nname. inpt points at
852 	 * the string we apply the regular expression to. prnt is used to
853 	 * suppress printing when we handle replacements on the link field
854 	 * (the user already saw that substitution go by)
855 	 */
856 	pt = rephead;
857 	(void)strlcpy(buf1, name, sizeof(buf1));
858 	inpt = buf1;
859 	outpt = nname;
860 	endpt = outpt + PAXPATHLEN;
861 
862 	/*
863 	 * try each replacement string in order
864 	 */
865 	while (pt != NULL) {
866 		do {
867 			/*
868 			 * check for a successful substitution, if not go to
869 			 * the next pattern, or cleanup if we were global
870 			 */
871 			if (regexec(&(pt->rcmp), inpt, MAXSUBEXP, pm, 0) != 0)
872 				break;
873 
874 			/*
875 			 * ok we found one. We have three parts, the prefix
876 			 * which did not match, the section that did and the
877 			 * tail (that also did not match). Copy the prefix to
878 			 * the final output buffer (watching to make sure we
879 			 * do not create a string too long).
880 			 */
881 			found = 1;
882 			rpt = inpt + pm[0].rm_so;
883 
884 			while ((inpt < rpt) && (outpt < endpt))
885 				*outpt++ = *inpt++;
886 			if (outpt == endpt)
887 				break;
888 
889 			/*
890 			 * for the second part (which matched the regular
891 			 * expression) apply the substitution using the
892 			 * replacement string and place it the prefix in the
893 			 * final output. If we have problems, skip it.
894 			 */
895 			if ((res = resub(&(pt->rcmp),pm,inpt,pt->nstr,outpt,endpt))
896 			    < 0) {
897 				if (prnt)
898 					paxwarn(1, "Replacement name error %s",
899 					    name);
900 				return(1);
901 			}
902 			outpt += res;
903 
904 			/*
905 			 * we set up to look again starting at the first
906 			 * character in the tail (of the input string right
907 			 * after the last character matched by the regular
908 			 * expression (inpt always points at the first char in
909 			 * the string to process). If we are not doing a global
910 			 * substitution, we will use inpt to copy the tail to
911 			 * the final result. Make sure we do not overrun the
912 			 * output buffer
913 			 */
914 			inpt += pm[0].rm_eo - pm[0].rm_so;
915 
916 			if ((outpt == endpt) || (*inpt == '\0'))
917 				break;
918 
919 			/*
920 			 * if the user wants global we keep trying to
921 			 * substitute until it fails, then we are done.
922 			 */
923 		} while (pt->flgs & GLOB);
924 
925 		if (found)
926 			break;
927 
928 		/*
929 		 * a successful substitution did NOT occur, try the next one
930 		 */
931 		pt = pt->fow;
932 	}
933 
934 	if (found) {
935 		/*
936 		 * we had a substitution, copy the last tail piece (if there is
937 		 * room) to the final result
938 		 */
939 		while ((outpt < endpt) && (*inpt != '\0'))
940 			*outpt++ = *inpt++;
941 
942 		*outpt = '\0';
943 		if ((outpt == endpt) && (*inpt != '\0')) {
944 			if (prnt)
945 				paxwarn(1,"Replacement name too long %s >> %s",
946 				    name, nname);
947 			return(1);
948 		}
949 
950 		/*
951 		 * inform the user of the result if wanted
952 		 */
953 		if (prnt && (pt->flgs & PRNT)) {
954 			if (*nname == '\0')
955 				(void)fprintf(stderr,"%s >> <empty string>\n",
956 				    name);
957 			else
958 				(void)fprintf(stderr,"%s >> %s\n", name, nname);
959 		}
960 
961 		/*
962 		 * if empty inform the caller this file is to be skipped
963 		 * otherwise copy the new name over the orig name and return
964 		 */
965 		if (*nname == '\0')
966 			return(1);
967 		*nlen = l_strncpy(name, nname, PAXPATHLEN + 1);
968 		name[PAXPATHLEN] = '\0';
969 	}
970 	return(0);
971 }
972 
973 
974 /*
975  * resub()
976  *	apply the replacement to the matched expression. expand out the old
977  * 	style ed(1) subexpression expansion.
978  * Return:
979  *	-1 if error, or the number of characters added to the destination.
980  */
981 
982 static int
983 resub(regex_t *rp, regmatch_t *pm, char *orig, char *src, char *dest,
984 	char *destend)
985 {
986 	char *spt;
987 	char *dpt;
988 	char c;
989 	regmatch_t *pmpt;
990 	int len;
991 	int subexcnt;
992 
993 	spt =  src;
994 	dpt = dest;
995 	subexcnt = rp->re_nsub;
996 	while ((dpt < destend) && ((c = *spt++) != '\0')) {
997 		/*
998 		 * see if we just have an ordinary replacement character
999 		 * or we refer to a subexpression.
1000 		 */
1001 		if (c == '&') {
1002 			pmpt = pm;
1003 		} else if ((c == '\\') && (*spt >= '0') && (*spt <= '9')) {
1004 			/*
1005 			 * make sure there is a subexpression as specified
1006 			 */
1007 			if ((len = *spt++ - '0') > subexcnt)
1008 				return(-1);
1009 			pmpt = pm + len;
1010 		} else {
1011  			/*
1012 			 * Ordinary character, just copy it
1013 			 */
1014  			if ((c == '\\') && ((*spt == '\\') || (*spt == '&')))
1015  				c = *spt++;
1016  			*dpt++ = c;
1017 			continue;
1018 		}
1019 
1020 		/*
1021 		 * continue if the subexpression is bogus
1022 		 */
1023 		if ((pmpt->rm_so < 0) || (pmpt->rm_eo < 0) ||
1024 		    ((len = pmpt->rm_eo - pmpt->rm_so) <= 0))
1025 			continue;
1026 
1027 		/*
1028 		 * copy the subexpression to the destination.
1029 		 * fail if we run out of space or the match string is damaged
1030 		 */
1031 		if (len > (destend - dpt))
1032 			len = destend - dpt;
1033 		if (l_strncpy(dpt, orig + pmpt->rm_so, len) != len)
1034 			return(-1);
1035 		dpt += len;
1036 	}
1037 	return(dpt - dest);
1038 }
1039