xref: /openbsd-src/bin/pax/pat_rep.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: pat_rep.c,v 1.41 2016/08/26 04:19:28 guenther Exp $	*/
2 /*	$NetBSD: pat_rep.c,v 1.4 1995/03/21 09:07:33 cgd Exp $	*/
3 
4 /*-
5  * Copyright (c) 1992 Keith Muller.
6  * Copyright (c) 1992, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * Keith Muller of the University of California, San Diego.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 
37 #include <sys/types.h>
38 #include <sys/stat.h>
39 #include <regex.h>
40 #include <stdio.h>
41 #include <stdlib.h>
42 #include <string.h>
43 
44 #include "pax.h"
45 #include "extern.h"
46 
47 /*
48  * data structure for storing user supplied replacement strings (-s)
49  */
50 typedef struct replace {
51 	char		*nstr;	/* the new string we will substitute with */
52 	regex_t		rcmp;	/* compiled regular expression used to match */
53 	int		flgs;	/* print conversions? global in operation?  */
54 #define	PRNT		0x1
55 #define	GLOB		0x2
56 	struct replace	*fow;	/* pointer to next pattern */
57 } REPLACE;
58 
59 /*
60  * routines to handle pattern matching, name modification (regular expression
61  * substitution and interactive renames), and destination name modification for
62  * copy (-rw). Both file name and link names are adjusted as required in these
63  * routines.
64  */
65 
66 #define MAXSUBEXP	10		/* max subexpressions, DO NOT CHANGE */
67 static PATTERN *pathead = NULL;		/* file pattern match list head */
68 static PATTERN *pattail = NULL;		/* file pattern match list tail */
69 static REPLACE *rephead = NULL;		/* replacement string list head */
70 static REPLACE *reptail = NULL;		/* replacement string list tail */
71 
72 static int rep_name(char *, size_t, int *, int);
73 static int tty_rename(ARCHD *);
74 static int fix_path(char *, int *, char *, int);
75 static int fn_match(char *, char *, char **);
76 static char * range_match(char *, int);
77 static int resub(regex_t *, regmatch_t *, char *, char *, char *, char *);
78 
79 /*
80  * rep_add()
81  *	parses the -s replacement string; compiles the regular expression
82  *	and stores the compiled value and it's replacement string together in
83  *	replacement string list. Input to this function is of the form:
84  *		/old/new/pg
85  *	The first char in the string specifies the delimiter used by this
86  *	replacement string. "Old" is a regular expression in "ed" format which
87  *	is compiled by regcomp() and is applied to filenames. "new" is the
88  *	substitution string; p and g are options flags for printing and global
89  *	replacement (over the single filename)
90  * Return:
91  *	0 if a proper replacement string and regular expression was added to
92  *	the list of replacement patterns; -1 otherwise.
93  */
94 
95 int
96 rep_add(char *str)
97 {
98 	char *pt1;
99 	char *pt2;
100 	REPLACE *rep;
101 	int res;
102 	char rebuf[BUFSIZ];
103 
104 	/*
105 	 * throw out the bad parameters
106 	 */
107 	if ((str == NULL) || (*str == '\0')) {
108 		paxwarn(1, "Empty replacement string");
109 		return(-1);
110 	}
111 
112 	/*
113 	 * first character in the string specifies what the delimiter is for
114 	 * this expression
115 	 */
116 	for (pt1 = str+1; *pt1; pt1++) {
117 		if (*pt1 == '\\') {
118 			pt1++;
119 			continue;
120 		}
121 		if (*pt1 == *str)
122 			break;
123 	}
124 	if (*pt1 == '\0') {
125 		paxwarn(1, "Invalid replacement string %s", str);
126 		return(-1);
127 	}
128 
129 	/*
130 	 * allocate space for the node that handles this replacement pattern
131 	 * and split out the regular expression and try to compile it
132 	 */
133 	if ((rep = malloc(sizeof(REPLACE))) == NULL) {
134 		paxwarn(1, "Unable to allocate memory for replacement string");
135 		return(-1);
136 	}
137 
138 	*pt1 = '\0';
139 	if ((res = regcomp(&(rep->rcmp), str+1, 0)) != 0) {
140 		regerror(res, &(rep->rcmp), rebuf, sizeof(rebuf));
141 		paxwarn(1, "%s while compiling regular expression %s", rebuf, str);
142 		free(rep);
143 		return(-1);
144 	}
145 
146 	/*
147 	 * put the delimiter back in case we need an error message and
148 	 * locate the delimiter at the end of the replacement string
149 	 * we then point the node at the new substitution string
150 	 */
151 	*pt1++ = *str;
152 	for (pt2 = pt1; *pt2; pt2++) {
153 		if (*pt2 == '\\') {
154 			pt2++;
155 			continue;
156 		}
157 		if (*pt2 == *str)
158 			break;
159 	}
160 	if (*pt2 == '\0') {
161 		regfree(&(rep->rcmp));
162 		free(rep);
163 		paxwarn(1, "Invalid replacement string %s", str);
164 		return(-1);
165 	}
166 
167 	*pt2 = '\0';
168 	rep->nstr = pt1;
169 	pt1 = pt2++;
170 	rep->flgs = 0;
171 
172 	/*
173 	 * set the options if any
174 	 */
175 	while (*pt2 != '\0') {
176 		switch (*pt2) {
177 		case 'g':
178 		case 'G':
179 			rep->flgs  |= GLOB;
180 			break;
181 		case 'p':
182 		case 'P':
183 			rep->flgs  |= PRNT;
184 			break;
185 		default:
186 			regfree(&(rep->rcmp));
187 			free(rep);
188 			*pt1 = *str;
189 			paxwarn(1, "Invalid replacement string option %s", str);
190 			return(-1);
191 		}
192 		++pt2;
193 	}
194 
195 	/*
196 	 * all done, link it in at the end
197 	 */
198 	rep->fow = NULL;
199 	if (rephead == NULL) {
200 		reptail = rephead = rep;
201 		return(0);
202 	}
203 	reptail->fow = rep;
204 	reptail = rep;
205 	return(0);
206 }
207 
208 /*
209  * pat_add()
210  *	add a pattern match to the pattern match list. Pattern matches are used
211  *	to select which archive members are extracted. (They appear as
212  *	arguments to pax in the list and read modes). If no patterns are
213  *	supplied to pax, all members in the archive will be selected (and the
214  *	pattern match list is empty).
215  * Return:
216  *	0 if the pattern was added to the list, -1 otherwise
217  */
218 
219 int
220 pat_add(char *str, char *chdirname)
221 {
222 	PATTERN *pt;
223 
224 	/*
225 	 * throw out the junk
226 	 */
227 	if ((str == NULL) || (*str == '\0')) {
228 		paxwarn(1, "Empty pattern string");
229 		return(-1);
230 	}
231 
232 	/*
233 	 * allocate space for the pattern and store the pattern. the pattern is
234 	 * part of argv so do not bother to copy it, just point at it. Add the
235 	 * node to the end of the pattern list
236 	 */
237 	if ((pt = malloc(sizeof(PATTERN))) == NULL) {
238 		paxwarn(1, "Unable to allocate memory for pattern string");
239 		return(-1);
240 	}
241 
242 	pt->pstr = str;
243 	pt->pend = NULL;
244 	pt->plen = strlen(str);
245 	pt->fow = NULL;
246 	pt->flgs = 0;
247 	pt->chdname = chdirname;
248 
249 	if (pathead == NULL) {
250 		pattail = pathead = pt;
251 		return(0);
252 	}
253 	pattail->fow = pt;
254 	pattail = pt;
255 	return(0);
256 }
257 
258 /*
259  * pat_chk()
260  *	complain if any the user supplied pattern did not result in a match to
261  *	a selected archive member.
262  */
263 
264 void
265 pat_chk(void)
266 {
267 	PATTERN *pt;
268 	int wban = 0;
269 
270 	/*
271 	 * walk down the list checking the flags to make sure MTCH was set,
272 	 * if not complain
273 	 */
274 	for (pt = pathead; pt != NULL; pt = pt->fow) {
275 		if (pt->flgs & MTCH)
276 			continue;
277 		if (!wban) {
278 			paxwarn(1, "WARNING! These patterns were not matched:");
279 			++wban;
280 		}
281 		(void)fprintf(stderr, "%s\n", pt->pstr);
282 	}
283 }
284 
285 /*
286  * pat_sel()
287  *	the archive member which matches a pattern was selected. Mark the
288  *	pattern as having selected an archive member. arcn->pat points at the
289  *	pattern that was matched. arcn->pat is set in pat_match()
290  *
291  *	NOTE: When the -c option is used, we are called when there was no match
292  *	by pat_match() (that means we did match before the inverted sense of
293  *	the logic). Now this seems really strange at first, but with -c we
294  *	need to keep track of those patterns that cause an archive member to NOT
295  *	be selected (it found an archive member with a specified pattern)
296  * Return:
297  *	0 if the pattern pointed at by arcn->pat was tagged as creating a
298  *	match, -1 otherwise.
299  */
300 
301 int
302 pat_sel(ARCHD *arcn)
303 {
304 	PATTERN *pt;
305 	PATTERN **ppt;
306 	size_t len;
307 
308 	/*
309 	 * if no patterns just return
310 	 */
311 	if ((pathead == NULL) || ((pt = arcn->pat) == NULL))
312 		return(0);
313 
314 	/*
315 	 * when we are NOT limited to a single match per pattern mark the
316 	 * pattern and return
317 	 */
318 	if (!nflag) {
319 		pt->flgs |= MTCH;
320 		return(0);
321 	}
322 
323 	/*
324 	 * we reach this point only when we allow a single selected match per
325 	 * pattern, if the pattern matches a directory and we do not have -d
326 	 * (dflag) we are done with this pattern. We may also be handed a file
327 	 * in the subtree of a directory. in that case when we are operating
328 	 * with -d, this pattern was already selected and we are done
329 	 */
330 	if (pt->flgs & DIR_MTCH)
331 		return(0);
332 
333 	if (!dflag && ((pt->pend != NULL) || (arcn->type == PAX_DIR))) {
334 		/*
335 		 * ok we matched a directory and we are allowing
336 		 * subtree matches but because of the -n only its children will
337 		 * match. This is tagged as a DIR_MTCH type.
338 		 * WATCH IT, the code assumes that pt->pend points
339 		 * into arcn->name and arcn->name has not been modified.
340 		 * If not we will have a big mess. Yup this is another kludge
341 		 */
342 
343 		/*
344 		 * if this was a prefix match, remove trailing part of path
345 		 * so we can copy it. Future matches will be exact prefix match
346 		 */
347 		if (pt->pend != NULL)
348 			*pt->pend = '\0';
349 
350 		if ((pt->pstr = strdup(arcn->name)) == NULL) {
351 			paxwarn(1, "Pattern select out of memory");
352 			if (pt->pend != NULL)
353 				*pt->pend = '/';
354 			pt->pend = NULL;
355 			return(-1);
356 		}
357 
358 		/*
359 		 * put the trailing / back in the source string
360 		 */
361 		if (pt->pend != NULL) {
362 			*pt->pend = '/';
363 			pt->pend = NULL;
364 		}
365 		pt->plen = strlen(pt->pstr);
366 
367 		/*
368 		 * strip off any trailing /, this should really never happen
369 		 */
370 		len = pt->plen - 1;
371 		if (*(pt->pstr + len) == '/') {
372 			*(pt->pstr + len) = '\0';
373 			pt->plen = len;
374 		}
375 		pt->flgs = DIR_MTCH | MTCH;
376 		arcn->pat = pt;
377 		return(0);
378 	}
379 
380 	/*
381 	 * we are then done with this pattern, so we delete it from the list
382 	 * because it can never be used for another match.
383 	 * Seems kind of strange to do for a -c, but the pax spec is really
384 	 * vague on the interaction of -c, -n and -d. We assume that when -c
385 	 * and the pattern rejects a member (i.e. it matched it) it is done.
386 	 * In effect we place the order of the flags as having -c last.
387 	 */
388 	pt = pathead;
389 	ppt = &pathead;
390 	while ((pt != NULL) && (pt != arcn->pat)) {
391 		ppt = &(pt->fow);
392 		pt = pt->fow;
393 	}
394 
395 	if (pt == NULL) {
396 		/*
397 		 * should never happen....
398 		 */
399 		paxwarn(1, "Pattern list inconsistent");
400 		return(-1);
401 	}
402 	*ppt = pt->fow;
403 	free(pt);
404 	arcn->pat = NULL;
405 	return(0);
406 }
407 
408 /*
409  * pat_match()
410  *	see if this archive member matches any supplied pattern, if a match
411  *	is found, arcn->pat is set to point at the potential pattern. Later if
412  *	this archive member is "selected" we process and mark the pattern as
413  *	one which matched a selected archive member (see pat_sel())
414  * Return:
415  *	0 if this archive member should be processed, 1 if it should be
416  *	skipped and -1 if we are done with all patterns (and pax should quit
417  *	looking for more members)
418  */
419 
420 int
421 pat_match(ARCHD *arcn)
422 {
423 	PATTERN *pt;
424 
425 	arcn->pat = NULL;
426 
427 	/*
428 	 * if there are no more patterns and we have -n (and not -c) we are
429 	 * done. otherwise with no patterns to match, matches all
430 	 */
431 	if (pathead == NULL) {
432 		if (nflag && !cflag)
433 			return(-1);
434 		return(0);
435 	}
436 
437 	/*
438 	 * have to search down the list one at a time looking for a match.
439 	 */
440 	pt = pathead;
441 	while (pt != NULL) {
442 		/*
443 		 * check for a file name match unless we have DIR_MTCH set in
444 		 * this pattern then we want a prefix match
445 		 */
446 		if (pt->flgs & DIR_MTCH) {
447 			/*
448 			 * this pattern was matched before to a directory
449 			 * as we must have -n set for this (but not -d). We can
450 			 * only match CHILDREN of that directory so we must use
451 			 * an exact prefix match (no wildcards).
452 			 */
453 			if ((arcn->name[pt->plen] == '/') &&
454 			    (strncmp(pt->pstr, arcn->name, pt->plen) == 0))
455 				break;
456 		} else if (fn_match(pt->pstr, arcn->name, &pt->pend) == 0)
457 			break;
458 		pt = pt->fow;
459 	}
460 
461 	/*
462 	 * return the result, remember that cflag (-c) inverts the sense of a
463 	 * match
464 	 */
465 	if (pt == NULL)
466 		return(cflag ? 0 : 1);
467 
468 	/*
469 	 * we had a match, now when we invert the sense (-c) we reject this
470 	 * member. However we have to tag the pattern a being successful, (in a
471 	 * match, not in selecting a archive member) so we call pat_sel() here.
472 	 */
473 	arcn->pat = pt;
474 	if (!cflag)
475 		return(0);
476 
477 	if (pat_sel(arcn) < 0)
478 		return(-1);
479 	arcn->pat = NULL;
480 	return(1);
481 }
482 
483 /*
484  * fn_match()
485  * Return:
486  *	0 if this archive member should be processed, 1 if it should be
487  *	skipped and -1 if we are done with all patterns (and pax should quit
488  *	looking for more members)
489  *	Note: *pend may be changed to show where the prefix ends.
490  */
491 
492 static int
493 fn_match(char *pattern, char *string, char **pend)
494 {
495 	char c;
496 	char test;
497 
498 	*pend = NULL;
499 	for (;;) {
500 		switch (c = *pattern++) {
501 		case '\0':
502 			/*
503 			 * Ok we found an exact match
504 			 */
505 			if (*string == '\0')
506 				return(0);
507 
508 			/*
509 			 * Check if it is a prefix match
510 			 */
511 			if ((dflag == 1) || (*string != '/'))
512 				return(-1);
513 
514 			/*
515 			 * It is a prefix match, remember where the trailing
516 			 * / is located
517 			 */
518 			*pend = string;
519 			return(0);
520 		case '?':
521 			if ((test = *string++) == '\0')
522 				return (-1);
523 			break;
524 		case '*':
525 			c = *pattern;
526 			/*
527 			 * Collapse multiple *'s.
528 			 */
529 			while (c == '*')
530 				c = *++pattern;
531 
532 			/*
533 			 * Optimized hack for pattern with a * at the end
534 			 */
535 			if (c == '\0')
536 				return (0);
537 
538 			/*
539 			 * General case, use recursion.
540 			 */
541 			while ((test = *string) != '\0') {
542 				if (!fn_match(pattern, string, pend))
543 					return (0);
544 				++string;
545 			}
546 			return (-1);
547 		case '[':
548 			/*
549 			 * range match
550 			 */
551 			if (((test = *string++) == '\0') ||
552 			    ((pattern = range_match(pattern, test)) == NULL))
553 				return (-1);
554 			break;
555 		case '\\':
556 		default:
557 			if (c != *string++)
558 				return (-1);
559 			break;
560 		}
561 	}
562 	/* NOTREACHED */
563 }
564 
565 static char *
566 range_match(char *pattern, int test)
567 {
568 	char c;
569 	char c2;
570 	int negate;
571 	int ok = 0;
572 
573 	if ((negate = (*pattern == '!')) != 0)
574 		++pattern;
575 
576 	while ((c = *pattern++) != ']') {
577 		/*
578 		 * Illegal pattern
579 		 */
580 		if (c == '\0')
581 			return (NULL);
582 
583 		if ((*pattern == '-') && ((c2 = pattern[1]) != '\0') &&
584 		    (c2 != ']')) {
585 			if ((c <= test) && (test <= c2))
586 				ok = 1;
587 			pattern += 2;
588 		} else if (c == test)
589 			ok = 1;
590 	}
591 	return (ok == negate ? NULL : pattern);
592 }
593 
594 /*
595  * has_dotdot()
596  *	Returns true iff the supplied path contains a ".." component.
597  */
598 
599 int
600 has_dotdot(const char *path)
601 {
602 	const char *p = path;
603 
604 	while ((p = strstr(p, "..")) != NULL) {
605 		if ((p == path || p[-1] == '/') &&
606 		    (p[2] == '/' || p[2] == '\0'))
607 			return (1);
608 		p += 2;
609 	}
610 	return (0);
611 }
612 
613 /*
614  * mod_name()
615  *	modify a selected file name. first attempt to apply replacement string
616  *	expressions, then apply interactive file rename. We apply replacement
617  *	string expressions to both filenames and file links (if we didn't the
618  *	links would point to the wrong place, and we could never be able to
619  *	move an archive that has a file link in it). When we rename files
620  *	interactively, we store that mapping (old name to user input name) so
621  *	if we spot any file links to the old file name in the future, we will
622  *	know exactly how to fix the file link.
623  * Return:
624  *	0 continue to  process file, 1 skip this file, -1 pax is finished
625  */
626 
627 int
628 mod_name(ARCHD *arcn)
629 {
630 	int res = 0;
631 
632 	/*
633 	 * Strip off leading '/' if appropriate.
634 	 * Currently, this option is only set for the tar format.
635 	 */
636 	while (rmleadslash && arcn->name[0] == '/') {
637 		if (arcn->name[1] == '\0') {
638 			arcn->name[0] = '.';
639 		} else {
640 			(void)memmove(arcn->name, &arcn->name[1],
641 			    strlen(arcn->name));
642 			arcn->nlen--;
643 		}
644 		if (rmleadslash < 2) {
645 			rmleadslash = 2;
646 			paxwarn(0, "Removing leading / from absolute path names in the archive");
647 		}
648 	}
649 	while (rmleadslash && arcn->ln_name[0] == '/' &&
650 	    PAX_IS_HARDLINK(arcn->type)) {
651 		if (arcn->ln_name[1] == '\0') {
652 			arcn->ln_name[0] = '.';
653 		} else {
654 			(void)memmove(arcn->ln_name, &arcn->ln_name[1],
655 			    strlen(arcn->ln_name));
656 			arcn->ln_nlen--;
657 		}
658 		if (rmleadslash < 2) {
659 			rmleadslash = 2;
660 			paxwarn(0, "Removing leading / from absolute path names in the archive");
661 		}
662 	}
663 	if (rmleadslash) {
664 		const char *last = NULL;
665 		const char *p = arcn->name;
666 
667 		while ((p = strstr(p, "..")) != NULL) {
668 			if ((p == arcn->name || p[-1] == '/') &&
669 			    (p[2] == '/' || p[2] == '\0'))
670 				last = p + 2;
671 			p += 2;
672 		}
673 		if (last != NULL) {
674 			last++;
675 			paxwarn(1, "Removing leading \"%.*s\"",
676 			    (int)(last - arcn->name), arcn->name);
677 			arcn->nlen = strlen(last);
678 			if (arcn->nlen > 0)
679 				memmove(arcn->name, last, arcn->nlen + 1);
680 			else {
681 				arcn->name[0] = '.';
682 				arcn->name[1] = '\0';
683 				arcn->nlen = 1;
684 			}
685 		}
686 	}
687 
688 	/*
689 	 * IMPORTANT: We have a problem. what do we do with symlinks?
690 	 * Modifying a hard link name makes sense, as we know the file it
691 	 * points at should have been seen already in the archive (and if it
692 	 * wasn't seen because of a read error or a bad archive, we lose
693 	 * anyway). But there are no such requirements for symlinks. On one
694 	 * hand the symlink that refers to a file in the archive will have to
695 	 * be modified to so it will still work at its new location in the
696 	 * file system. On the other hand a symlink that points elsewhere (and
697 	 * should continue to do so) should not be modified. There is clearly
698 	 * no perfect solution here. So we handle them like hardlinks. Clearly
699 	 * a replacement made by the interactive rename mapping is very likely
700 	 * to be correct since it applies to a single file and is an exact
701 	 * match. The regular expression replacements are a little harder to
702 	 * justify though. We claim that the symlink name is only likely
703 	 * to be replaced when it points within the file tree being moved and
704 	 * in that case it should be modified. what we really need to do is to
705 	 * call an oracle here. :)
706 	 */
707 	if (rephead != NULL) {
708 		/*
709 		 * we have replacement strings, modify the name and the link
710 		 * name if any.
711 		 */
712 		if ((res = rep_name(arcn->name, sizeof(arcn->name), &(arcn->nlen), 1)) != 0)
713 			return(res);
714 
715 		if (PAX_IS_LINK(arcn->type)) {
716 			if ((res = rep_name(arcn->ln_name,
717 			    sizeof(arcn->ln_name), &(arcn->ln_nlen), 0)) != 0)
718 				return(res);
719 		}
720 	}
721 
722 	if (iflag) {
723 		/*
724 		 * perform interactive file rename, then map the link if any
725 		 */
726 		if ((res = tty_rename(arcn)) != 0)
727 			return(res);
728 		if (PAX_IS_LINK(arcn->type))
729 			sub_name(arcn->ln_name, &(arcn->ln_nlen),
730 			    sizeof(arcn->ln_name));
731 	}
732 	return(res);
733 }
734 
735 /*
736  * tty_rename()
737  *	Prompt the user for a replacement file name. A "." keeps the old name,
738  *	a empty line skips the file, and an EOF on reading the tty, will cause
739  *	pax to stop processing and exit. Otherwise the file name input, replaces
740  *	the old one.
741  * Return:
742  *	0 process this file, 1 skip this file, -1 we need to exit pax
743  */
744 
745 static int
746 tty_rename(ARCHD *arcn)
747 {
748 	char tmpname[PAXPATHLEN+2];
749 	int res;
750 
751 	/*
752 	 * prompt user for the replacement name for a file, keep trying until
753 	 * we get some reasonable input. Archives may have more than one file
754 	 * on them with the same name (from updates etc). We print verbose info
755 	 * on the file so the user knows what is up.
756 	 */
757 	tty_prnt("\nATTENTION: %s interactive file rename operation.\n", argv0);
758 
759 	for (;;) {
760 		ls_tty(arcn);
761 		tty_prnt("Input new name, or a \".\" to keep the old name, ");
762 		tty_prnt("or a \"return\" to skip this file.\n");
763 		tty_prnt("Input > ");
764 		if (tty_read(tmpname, sizeof(tmpname)) < 0)
765 			return(-1);
766 		if (strcmp(tmpname, "..") == 0) {
767 			tty_prnt("Try again, illegal file name: ..\n");
768 			continue;
769 		}
770 		if (strlen(tmpname) > PAXPATHLEN) {
771 			tty_prnt("Try again, file name too long\n");
772 			continue;
773 		}
774 		break;
775 	}
776 
777 	/*
778 	 * empty file name, skips this file. a "." leaves it alone
779 	 */
780 	if (tmpname[0] == '\0') {
781 		tty_prnt("Skipping file.\n");
782 		return(1);
783 	}
784 	if ((tmpname[0] == '.') && (tmpname[1] == '\0')) {
785 		tty_prnt("Processing continues, name unchanged.\n");
786 		return(0);
787 	}
788 
789 	/*
790 	 * ok the name changed. We may run into links that point at this
791 	 * file later. we have to remember where the user sent the file
792 	 * in order to repair any links.
793 	 */
794 	tty_prnt("Processing continues, name changed to: %s\n", tmpname);
795 	res = add_name(arcn->name, arcn->nlen, tmpname);
796 	arcn->nlen = strlcpy(arcn->name, tmpname, sizeof(arcn->name));
797 	if (arcn->nlen >= sizeof(arcn->name))
798 		arcn->nlen = sizeof(arcn->name) - 1; /* XXX truncate? */
799 	if (res < 0)
800 		return(-1);
801 	return(0);
802 }
803 
804 /*
805  * set_dest()
806  *	fix up the file name and the link name (if any) so this file will land
807  *	in the destination directory (used during copy() -rw).
808  * Return:
809  *	0 if ok, -1 if failure (name too long)
810  */
811 
812 int
813 set_dest(ARCHD *arcn, char *dest_dir, int dir_len)
814 {
815 	if (fix_path(arcn->name, &(arcn->nlen), dest_dir, dir_len) < 0)
816 		return(-1);
817 
818 	/*
819 	 * It is really hard to deal with symlinks here, we cannot be sure
820 	 * if the name they point was moved (or will be moved). It is best to
821 	 * leave them alone.
822 	 */
823 	if (!PAX_IS_HARDLINK(arcn->type))
824 		return(0);
825 
826 	if (fix_path(arcn->ln_name, &(arcn->ln_nlen), dest_dir, dir_len) < 0)
827 		return(-1);
828 	return(0);
829 }
830 
831 /*
832  * fix_path
833  *	concatenate dir_name and or_name and store the result in or_name (if
834  *	it fits). This is one ugly function.
835  * Return:
836  *	0 if ok, -1 if the final name is too long
837  */
838 
839 static int
840 fix_path(char *or_name, int *or_len, char *dir_name, int dir_len)
841 {
842 	char *src;
843 	char *dest;
844 	char *start;
845 	int len;
846 
847 	/*
848 	 * we shift the or_name to the right enough to tack in the dir_name
849 	 * at the front. We make sure we have enough space for it all before
850 	 * we start. since dest always ends in a slash, we skip of or_name
851 	 * if it also starts with one.
852 	 */
853 	start = or_name;
854 	src = start + *or_len;
855 	dest = src + dir_len;
856 	if (*start == '/') {
857 		++start;
858 		--dest;
859 	}
860 	if ((len = dest - or_name) > PAXPATHLEN) {
861 		paxwarn(1, "File name %s/%s, too long", dir_name, start);
862 		return(-1);
863 	}
864 	*or_len = len;
865 
866 	/*
867 	 * enough space, shift
868 	 */
869 	while (src >= start)
870 		*dest-- = *src--;
871 	src = dir_name + dir_len - 1;
872 
873 	/*
874 	 * splice in the destination directory name
875 	 */
876 	while (src >= dir_name)
877 		*dest-- = *src--;
878 
879 	*(or_name + len) = '\0';
880 	return(0);
881 }
882 
883 /*
884  * rep_name()
885  *	walk down the list of replacement strings applying each one in order.
886  *	when we find one with a successful substitution, we modify the name
887  *	as specified. if required, we print the results. if the resulting name
888  *	is empty, we will skip this archive member. We use the regexp(3)
889  *	routines (regexp() ought to win a prize as having the most cryptic
890  *	library function manual page).
891  *	--Parameters--
892  *	name is the file name we are going to apply the regular expressions to
893  *	(and may be modified)
894  *	nsize is the size of the name buffer.
895  *	nlen is the length of this name (and is modified to hold the length of
896  *	the final string).
897  *	prnt is a flag that says whether to print the final result.
898  * Return:
899  *	0 if substitution was successful, 1 if we are to skip the file (the name
900  *	ended up empty)
901  */
902 
903 static int
904 rep_name(char *name, size_t nsize, int *nlen, int prnt)
905 {
906 	REPLACE *pt;
907 	char *inpt;
908 	char *outpt;
909 	char *endpt;
910 	char *rpt;
911 	int found = 0;
912 	int res;
913 	regmatch_t pm[MAXSUBEXP];
914 	char nname[PAXPATHLEN+1];	/* final result of all replacements */
915 	char buf1[PAXPATHLEN+1];	/* where we work on the name */
916 
917 	/*
918 	 * copy the name into buf1, where we will work on it. We need to keep
919 	 * the orig string around so we can print out the result of the final
920 	 * replacement. We build up the final result in nname. inpt points at
921 	 * the string we apply the regular expression to. prnt is used to
922 	 * suppress printing when we handle replacements on the link field
923 	 * (the user already saw that substitution go by)
924 	 */
925 	pt = rephead;
926 	(void)strlcpy(buf1, name, sizeof(buf1));
927 	inpt = buf1;
928 	outpt = nname;
929 	endpt = outpt + PAXPATHLEN;
930 
931 	/*
932 	 * try each replacement string in order
933 	 */
934 	while (pt != NULL) {
935 		do {
936 			char *oinpt = inpt;
937 			/*
938 			 * check for a successful substitution, if not go to
939 			 * the next pattern, or cleanup if we were global
940 			 */
941 			if (regexec(&(pt->rcmp), inpt, MAXSUBEXP, pm, 0) != 0)
942 				break;
943 
944 			/*
945 			 * ok we found one. We have three parts, the prefix
946 			 * which did not match, the section that did and the
947 			 * tail (that also did not match). Copy the prefix to
948 			 * the final output buffer (watching to make sure we
949 			 * do not create a string too long).
950 			 */
951 			found = 1;
952 			rpt = inpt + pm[0].rm_so;
953 
954 			while ((inpt < rpt) && (outpt < endpt))
955 				*outpt++ = *inpt++;
956 			if (outpt == endpt)
957 				break;
958 
959 			/*
960 			 * for the second part (which matched the regular
961 			 * expression) apply the substitution using the
962 			 * replacement string and place it the prefix in the
963 			 * final output. If we have problems, skip it.
964 			 */
965 			if ((res = resub(&(pt->rcmp),pm,pt->nstr,oinpt,outpt,endpt))
966 			    < 0) {
967 				if (prnt)
968 					paxwarn(1, "Replacement name error %s",
969 					    name);
970 				return(1);
971 			}
972 			outpt += res;
973 
974 			/*
975 			 * we set up to look again starting at the first
976 			 * character in the tail (of the input string right
977 			 * after the last character matched by the regular
978 			 * expression (inpt always points at the first char in
979 			 * the string to process). If we are not doing a global
980 			 * substitution, we will use inpt to copy the tail to
981 			 * the final result. Make sure we do not overrun the
982 			 * output buffer
983 			 */
984 			inpt += pm[0].rm_eo - pm[0].rm_so;
985 
986 			if ((outpt == endpt) || (*inpt == '\0'))
987 				break;
988 
989 			/*
990 			 * if the user wants global we keep trying to
991 			 * substitute until it fails, then we are done.
992 			 */
993 		} while (pt->flgs & GLOB);
994 
995 		if (found)
996 			break;
997 
998 		/*
999 		 * a successful substitution did NOT occur, try the next one
1000 		 */
1001 		pt = pt->fow;
1002 	}
1003 
1004 	if (found) {
1005 		/*
1006 		 * we had a substitution, copy the last tail piece (if there is
1007 		 * room) to the final result
1008 		 */
1009 		while ((outpt < endpt) && (*inpt != '\0'))
1010 			*outpt++ = *inpt++;
1011 
1012 		*outpt = '\0';
1013 		if ((outpt == endpt) && (*inpt != '\0')) {
1014 			if (prnt)
1015 				paxwarn(1,"Replacement name too long %s >> %s",
1016 				    name, nname);
1017 			return(1);
1018 		}
1019 
1020 		/*
1021 		 * inform the user of the result if wanted
1022 		 */
1023 		if (prnt && (pt->flgs & PRNT)) {
1024 			if (*nname == '\0')
1025 				(void)fprintf(stderr,"%s >> <empty string>\n",
1026 				    name);
1027 			else
1028 				(void)fprintf(stderr,"%s >> %s\n", name, nname);
1029 		}
1030 
1031 		/*
1032 		 * if empty inform the caller this file is to be skipped
1033 		 * otherwise copy the new name over the orig name and return
1034 		 */
1035 		if (*nname == '\0')
1036 			return(1);
1037 		*nlen = strlcpy(name, nname, nsize);
1038 	}
1039 	return(0);
1040 }
1041 
1042 /*
1043  * resub()
1044  *	apply the replacement to the matched expression. expand out the old
1045  *	style ed(1) subexpression expansion.
1046  * Return:
1047  *	-1 if error, or the number of characters added to the destination.
1048  */
1049 
1050 static int
1051 resub(regex_t *rp, regmatch_t *pm, char *src, char *inpt, char *dest,
1052 	char *destend)
1053 {
1054 	char *spt;
1055 	char *dpt;
1056 	char c;
1057 	regmatch_t *pmpt;
1058 	int len;
1059 	int subexcnt;
1060 
1061 	spt =  src;
1062 	dpt = dest;
1063 	subexcnt = rp->re_nsub;
1064 	while ((dpt < destend) && ((c = *spt++) != '\0')) {
1065 		/*
1066 		 * see if we just have an ordinary replacement character
1067 		 * or we refer to a subexpression.
1068 		 */
1069 		if (c == '&') {
1070 			pmpt = pm;
1071 		} else if ((c == '\\') && (*spt >= '0') && (*spt <= '9')) {
1072 			/*
1073 			 * make sure there is a subexpression as specified
1074 			 */
1075 			if ((len = *spt++ - '0') > subexcnt)
1076 				return(-1);
1077 			pmpt = pm + len;
1078 		} else {
1079 			/*
1080 			 * Ordinary character, just copy it
1081 			 */
1082 			if ((c == '\\') && (*spt != '\0'))
1083 				c = *spt++;
1084 			*dpt++ = c;
1085 			continue;
1086 		}
1087 
1088 		/*
1089 		 * continue if the subexpression is bogus
1090 		 */
1091 		if ((pmpt->rm_so < 0) || (pmpt->rm_eo < 0) ||
1092 		    ((len = pmpt->rm_eo - pmpt->rm_so) <= 0))
1093 			continue;
1094 
1095 		/*
1096 		 * copy the subexpression to the destination.
1097 		 * fail if we run out of space or the match string is damaged
1098 		 */
1099 		if (len > (destend - dpt))
1100 			return (-1);
1101 		strncpy(dpt, inpt + pmpt->rm_so, len);
1102 		dpt += len;
1103 	}
1104 	return(dpt - dest);
1105 }
1106