xref: /openbsd-src/bin/pax/ftree.c (revision a28daedfc357b214be5c701aa8ba8adb29a7f1c2)
1 /*	$OpenBSD: ftree.c,v 1.28 2008/05/06 06:54:28 henning Exp $	*/
2 /*	$NetBSD: ftree.c,v 1.4 1995/03/21 09:07:21 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 #ifndef lint
38 #if 0
39 static const char sccsid[] = "@(#)ftree.c	8.2 (Berkeley) 4/18/94";
40 #else
41 static const char rcsid[] = "$OpenBSD: ftree.c,v 1.28 2008/05/06 06:54:28 henning Exp $";
42 #endif
43 #endif /* not lint */
44 
45 #include <sys/types.h>
46 #include <sys/time.h>
47 #include <sys/stat.h>
48 #include <sys/param.h>
49 #include <unistd.h>
50 #include <string.h>
51 #include <stdio.h>
52 #include <errno.h>
53 #include <stdlib.h>
54 #include <fts.h>
55 #include "pax.h"
56 #include "ftree.h"
57 #include "extern.h"
58 
59 /*
60  * routines to interface with the fts library function.
61  *
62  * file args supplied to pax are stored on a single linked list (of type FTREE)
63  * and given to fts to be processed one at a time. pax "selects" files from
64  * the expansion of each arg into the corresponding file tree (if the arg is a
65  * directory, otherwise the node itself is just passed to pax). The selection
66  * is modified by the -n and -u flags. The user is informed when a specific
67  * file arg does not generate any selected files. -n keeps expanding the file
68  * tree arg until one of its files is selected, then skips to the next file
69  * arg. when the user does not supply the file trees as command line args to
70  * pax, they are read from stdin
71  */
72 
73 static FTS *ftsp = NULL;		/* current FTS handle */
74 static int ftsopts;			/* options to be used on fts_open */
75 static char *farray[2];			/* array for passing each arg to fts */
76 static FTREE *fthead = NULL;		/* head of linked list of file args */
77 static FTREE *fttail = NULL;		/* tail of linked list of file args */
78 static FTREE *ftcur = NULL;		/* current file arg being processed */
79 static FTSENT *ftent = NULL;		/* current file tree entry */
80 static int ftree_skip;			/* when set skip to next file arg */
81 
82 static int ftree_arg(void);
83 static char *getpathname(char *, int);
84 
85 /*
86  * ftree_start()
87  *	initialize the options passed to fts_open() during this run of pax
88  *	options are based on the selection of pax options by the user
89  *	fts_start() also calls fts_arg() to open the first valid file arg. We
90  *	also attempt to reset directory access times when -t (tflag) is set.
91  * Return:
92  *	0 if there is at least one valid file arg to process, -1 otherwise
93  */
94 
95 int
96 ftree_start(void)
97 {
98 	/*
99 	 * set up the operation mode of fts, open the first file arg. We must
100 	 * use FTS_NOCHDIR, as the user may have to open multiple archives and
101 	 * if fts did a chdir off into the boondocks, we may create an archive
102 	 * volume in an place where the user did not expect to.
103 	 */
104 	ftsopts = FTS_NOCHDIR;
105 
106 	/*
107 	 * optional user flags that effect file traversal
108 	 * -H command line symlink follow only (half follow)
109 	 * -L follow sylinks (logical)
110 	 * -P do not follow sylinks (physical). This is the default.
111 	 * -X do not cross over mount points
112 	 * -t preserve access times on files read.
113 	 * -n select only the first member of a file tree when a match is found
114 	 * -d do not extract subtrees rooted at a directory arg.
115 	 */
116 	if (Lflag)
117 		ftsopts |= FTS_LOGICAL;
118 	else
119 		ftsopts |= FTS_PHYSICAL;
120 	if (Hflag)
121 		ftsopts |= FTS_COMFOLLOW;
122 	if (Xflag)
123 		ftsopts |= FTS_XDEV;
124 
125 	if ((fthead == NULL) && ((farray[0] = malloc(PAXPATHLEN+2)) == NULL)) {
126 		paxwarn(1, "Unable to allocate memory for file name buffer");
127 		return(-1);
128 	}
129 
130 	if (ftree_arg() < 0)
131 		return(-1);
132 	if (tflag && (atdir_start() < 0))
133 		return(-1);
134 	return(0);
135 }
136 
137 /*
138  * ftree_add()
139  *	add the arg to the linked list of files to process. Each will be
140  *	processed by fts one at a time
141  * Return:
142  *	0 if added to the linked list, -1 if failed
143  */
144 
145 int
146 ftree_add(char *str, int chflg)
147 {
148 	FTREE *ft;
149 	int len;
150 
151 	/*
152 	 * simple check for bad args
153 	 */
154 	if ((str == NULL) || (*str == '\0')) {
155 		paxwarn(0, "Invalid file name argument");
156 		return(-1);
157 	}
158 
159 	/*
160 	 * allocate FTREE node and add to the end of the linked list (args are
161 	 * processed in the same order they were passed to pax). Get rid of any
162 	 * trailing / the user may pass us. (watch out for / by itself).
163 	 */
164 	if ((ft = (FTREE *)malloc(sizeof(FTREE))) == NULL) {
165 		paxwarn(0, "Unable to allocate memory for filename");
166 		return(-1);
167 	}
168 
169 	if (((len = strlen(str) - 1) > 0) && (str[len] == '/'))
170 		str[len] = '\0';
171 	ft->fname = str;
172 	ft->refcnt = 0;
173 	ft->newercnt = 0;
174 	ft->chflg = chflg;
175 	ft->fow = NULL;
176 	if (fthead == NULL) {
177 		fttail = fthead = ft;
178 		return(0);
179 	}
180 	fttail->fow = ft;
181 	fttail = ft;
182 	return(0);
183 }
184 
185 /*
186  * ftree_sel()
187  *	this entry has been selected by pax. bump up reference count and handle
188  *	-n and -d processing.
189  */
190 
191 void
192 ftree_sel(ARCHD *arcn)
193 {
194 	/*
195 	 * set reference bit for this pattern. This linked list is only used
196 	 * when file trees are supplied pax as args. The list is not used when
197 	 * the trees are read from stdin.
198 	 */
199 	if (ftcur != NULL)
200 		ftcur->refcnt = 1;
201 
202 	/*
203 	 * if -n we are done with this arg, force a skip to the next arg when
204 	 * pax asks for the next file in next_file().
205 	 * if -d we tell fts only to match the directory (if the arg is a dir)
206 	 * and not the entire file tree rooted at that point.
207 	 */
208 	if (nflag)
209 		ftree_skip = 1;
210 
211 	if (!dflag || (arcn->type != PAX_DIR))
212 		return;
213 
214 	if (ftent != NULL)
215 		(void)fts_set(ftsp, ftent, FTS_SKIP);
216 }
217 
218 /*
219  * ftree_skipped_newer()
220  *	file has been skipped because a newer file exists and -u/-D given
221  */
222 
223 void
224 ftree_skipped_newer(ARCHD *arcn)
225 {
226 	/* skipped due to -u/-D, mark accordingly */
227 	if (ftcur != NULL)
228 		ftcur->newercnt = 1;
229 }
230 
231 /*
232  * ftree_chk()
233  *	called at end on pax execution. Prints all those file args that did not
234  *	have a selected member (reference count still 0)
235  */
236 
237 void
238 ftree_chk(void)
239 {
240 	FTREE *ft;
241 	int wban = 0;
242 
243 	/*
244 	 * make sure all dir access times were reset.
245 	 */
246 	if (tflag)
247 		atdir_end();
248 
249 	/*
250 	 * walk down list and check reference count. Print out those members
251 	 * that never had a match
252 	 */
253 	for (ft = fthead; ft != NULL; ft = ft->fow) {
254 		if ((ft->refcnt > 0) || ft->newercnt > 0 || ft->chflg)
255 			continue;
256 		if (wban == 0) {
257 			paxwarn(1,"WARNING! These file names were not selected:");
258 			++wban;
259 		}
260 		(void)fprintf(stderr, "%s\n", ft->fname);
261 	}
262 }
263 
264 /*
265  * ftree_arg()
266  *	Get the next file arg for fts to process. Can be from either the linked
267  *	list or read from stdin when the user did not them as args to pax. Each
268  *	arg is processed until the first successful fts_open().
269  * Return:
270  *	0 when the next arg is ready to go, -1 if out of file args (or EOF on
271  *	stdin).
272  */
273 
274 static int
275 ftree_arg(void)
276 {
277 
278 	/*
279 	 * close off the current file tree
280 	 */
281 	if (ftsp != NULL) {
282 		(void)fts_close(ftsp);
283 		ftsp = NULL;
284 	}
285 
286 	/*
287 	 * keep looping until we get a valid file tree to process. Stop when we
288 	 * reach the end of the list (or get an eof on stdin)
289 	 */
290 	for (;;) {
291 		if (fthead == NULL) {
292 			/*
293 			 * the user didn't supply any args, get the file trees
294 			 * to process from stdin;
295 			 */
296 			if (getpathname(farray[0], PAXPATHLEN+1) == NULL)
297 				return(-1);
298 		} else {
299 			/*
300 			 * the user supplied the file args as arguments to pax
301 			 */
302 			if (ftcur == NULL)
303 				ftcur = fthead;
304 			else if ((ftcur = ftcur->fow) == NULL)
305 				return(-1);
306 			if (ftcur->chflg) {
307 				/* First fchdir() back... */
308 				if (fchdir(cwdfd) < 0) {
309 					syswarn(1, errno,
310 					  "Can't fchdir to starting directory");
311 					return(-1);
312 				}
313 				if (chdir(ftcur->fname) < 0) {
314 					syswarn(1, errno, "Can't chdir to %s",
315 					    ftcur->fname);
316 					return(-1);
317 				}
318 				continue;
319 			} else
320 				farray[0] = ftcur->fname;
321 		}
322 
323 		/*
324 		 * watch it, fts wants the file arg stored in a array of char
325 		 * ptrs, with the last one a null. we use a two element array
326 		 * and set farray[0] to point at the buffer with the file name
327 		 * in it. We cannot pass all the file args to fts at one shot
328 		 * as we need to keep a handle on which file arg generates what
329 		 * files (the -n and -d flags need this). If the open is
330 		 * successful, return a 0.
331 		 */
332 		if ((ftsp = fts_open(farray, ftsopts, NULL)) != NULL)
333 			break;
334 	}
335 	return(0);
336 }
337 
338 /*
339  * next_file()
340  *	supplies the next file to process in the supplied archd structure.
341  * Return:
342  *	0 when contents of arcn have been set with the next file, -1 when done.
343  */
344 
345 int
346 next_file(ARCHD *arcn)
347 {
348 	int cnt;
349 	time_t atime;
350 	time_t mtime;
351 
352 	/*
353 	 * ftree_sel() might have set the ftree_skip flag if the user has the
354 	 * -n option and a file was selected from this file arg tree. (-n says
355 	 * only one member is matched for each pattern) ftree_skip being 1
356 	 * forces us to go to the next arg now.
357 	 */
358 	if (ftree_skip) {
359 		/*
360 		 * clear and go to next arg
361 		 */
362 		ftree_skip = 0;
363 		if (ftree_arg() < 0)
364 			return(-1);
365 	}
366 
367 	/*
368 	 * loop until we get a valid file to process
369 	 */
370 	for (;;) {
371 		if ((ftent = fts_read(ftsp)) == NULL) {
372 			if (errno)
373 				syswarn(1, errno, "next_file");
374 			/*
375 			 * out of files in this tree, go to next arg, if none
376 			 * we are done
377 			 */
378 			if (ftree_arg() < 0)
379 				return(-1);
380 			continue;
381 		}
382 
383 		/*
384 		 * handle each type of fts_read() flag
385 		 */
386 		switch (ftent->fts_info) {
387 		case FTS_D:
388 		case FTS_DEFAULT:
389 		case FTS_F:
390 		case FTS_SL:
391 		case FTS_SLNONE:
392 			/*
393 			 * these are all ok
394 			 */
395 			break;
396 		case FTS_DP:
397 			/*
398 			 * already saw this directory. If the user wants file
399 			 * access times reset, we use this to restore the
400 			 * access time for this directory since this is the
401 			 * last time we will see it in this file subtree
402 			 * remember to force the time (this is -t on a read
403 			 * directory, not a created directory).
404 			 */
405 			if (!tflag || (get_atdir(ftent->fts_statp->st_dev,
406 			    ftent->fts_statp->st_ino, &mtime, &atime) < 0))
407 				continue;
408 			set_ftime(ftent->fts_path, mtime, atime, 1);
409 			continue;
410 		case FTS_DC:
411 			/*
412 			 * fts claims a file system cycle
413 			 */
414 			paxwarn(1,"File system cycle found at %s",ftent->fts_path);
415 			continue;
416 		case FTS_DNR:
417 			syswarn(1, ftent->fts_errno,
418 			    "Unable to read directory %s", ftent->fts_path);
419 			continue;
420 		case FTS_ERR:
421 			syswarn(1, ftent->fts_errno,
422 			    "File system traversal error");
423 			continue;
424 		case FTS_NS:
425 		case FTS_NSOK:
426 			syswarn(1, ftent->fts_errno,
427 			    "Unable to access %s", ftent->fts_path);
428 			continue;
429 		}
430 
431 		/*
432 		 * ok got a file tree node to process. copy info into arcn
433 		 * structure (initialize as required)
434 		 */
435 		arcn->skip = 0;
436 		arcn->pad = 0;
437 		arcn->ln_nlen = 0;
438 		arcn->ln_name[0] = '\0';
439 		memcpy(&arcn->sb, ftent->fts_statp, sizeof(arcn->sb));
440 
441 		/*
442 		 * file type based set up and copy into the arcn struct
443 		 * SIDE NOTE:
444 		 * we try to reset the access time on all files and directories
445 		 * we may read when the -t flag is specified. files are reset
446 		 * when we close them after copying. we reset the directories
447 		 * when we are done with their file tree (we also clean up at
448 		 * end in case we cut short a file tree traversal). However
449 		 * there is no way to reset access times on symlinks.
450 		 */
451 		switch (S_IFMT & arcn->sb.st_mode) {
452 		case S_IFDIR:
453 			arcn->type = PAX_DIR;
454 			if (!tflag)
455 				break;
456 			add_atdir(ftent->fts_path, arcn->sb.st_dev,
457 			    arcn->sb.st_ino, arcn->sb.st_mtime,
458 			    arcn->sb.st_atime);
459 			break;
460 		case S_IFCHR:
461 			arcn->type = PAX_CHR;
462 			break;
463 		case S_IFBLK:
464 			arcn->type = PAX_BLK;
465 			break;
466 		case S_IFREG:
467 			/*
468 			 * only regular files with have data to store on the
469 			 * archive. all others will store a zero length skip.
470 			 * the skip field is used by pax for actual data it has
471 			 * to read (or skip over).
472 			 */
473 			arcn->type = PAX_REG;
474 			arcn->skip = arcn->sb.st_size;
475 			break;
476 		case S_IFLNK:
477 			arcn->type = PAX_SLK;
478 			/*
479 			 * have to read the symlink path from the file
480 			 */
481 			if ((cnt = readlink(ftent->fts_path, arcn->ln_name,
482 			    PAXPATHLEN)) < 0) {
483 				syswarn(1, errno, "Unable to read symlink %s",
484 				    ftent->fts_path);
485 				continue;
486 			}
487 			/*
488 			 * set link name length, watch out readlink does not
489 			 * always NUL terminate the link path
490 			 */
491 			arcn->ln_name[cnt] = '\0';
492 			arcn->ln_nlen = cnt;
493 			break;
494 		case S_IFSOCK:
495 			/*
496 			 * under BSD storing a socket is senseless but we will
497 			 * let the format specific write function make the
498 			 * decision of what to do with it.
499 			 */
500 			arcn->type = PAX_SCK;
501 			break;
502 		case S_IFIFO:
503 			arcn->type = PAX_FIF;
504 			break;
505 		}
506 		break;
507 	}
508 
509 	/*
510 	 * copy file name, set file name length
511 	 */
512 	arcn->nlen = strlcpy(arcn->name, ftent->fts_path, sizeof(arcn->name));
513 	if (arcn->nlen >= sizeof(arcn->name))
514 		arcn->nlen = sizeof(arcn->name) - 1; /* XXX truncate? */
515 	arcn->org_name = ftent->fts_path;
516 	return(0);
517 }
518 
519 /*
520  * getpathname()
521  *	Reads a pathname from stdin, handling NUL- or newline-termination.
522  * Return:
523  *	NULL at end of file, otherwise the NUL-terminated buffer.
524  */
525 
526 static char *
527 getpathname(char *buf, int buflen)
528 {
529 	char *bp, *ep;
530 	int ch, term;
531 
532 	if (zeroflag) {
533 		/*
534 		 * Read a NUL-terminated pathname, being especially
535 		 * paranoid about proper termination and pathname length.
536 		 */
537 		for (bp = buf, ep = buf + buflen; bp < ep; bp++) {
538 			if ((ch = getchar()) == EOF) {
539 				if (bp != buf)
540 					paxwarn(1, "Ignoring unterminated "
541 					    "pathname at EOF");
542 				return(NULL);
543 			}
544 			if ((*bp = ch) == '\0')
545 				return(buf);
546 		}
547 		/* Too long - skip this path */
548 		*--bp = '\0';
549 		term = '\0';
550 	} else {
551 		if (fgets(buf, buflen, stdin) == NULL)
552 			return(NULL);
553 		if ((bp = strchr(buf, '\n')) != NULL || feof(stdin)) {
554 			if (bp != NULL)
555 				*bp = '\0';
556 			return(buf);
557 		}
558 		/* Too long - skip this path */
559 		term = '\n';
560 	}
561 	while ((ch = getchar()) != term && ch != EOF)
562 		;
563 	paxwarn(1, "Ignoring too-long pathname: %s", buf);
564 	return(NULL);
565 }
566