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