xref: /openbsd-src/bin/pax/ftree.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: ftree.c,v 1.30 2012/12/04 02:24:45 deraadt 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 #include <sys/types.h>
38 #include <sys/time.h>
39 #include <sys/stat.h>
40 #include <unistd.h>
41 #include <string.h>
42 #include <stdio.h>
43 #include <errno.h>
44 #include <stdlib.h>
45 #include <fts.h>
46 #include "pax.h"
47 #include "ftree.h"
48 #include "extern.h"
49 
50 /*
51  * routines to interface with the fts library function.
52  *
53  * file args supplied to pax are stored on a single linked list (of type FTREE)
54  * and given to fts to be processed one at a time. pax "selects" files from
55  * the expansion of each arg into the corresponding file tree (if the arg is a
56  * directory, otherwise the node itself is just passed to pax). The selection
57  * is modified by the -n and -u flags. The user is informed when a specific
58  * file arg does not generate any selected files. -n keeps expanding the file
59  * tree arg until one of its files is selected, then skips to the next file
60  * arg. when the user does not supply the file trees as command line args to
61  * pax, they are read from stdin
62  */
63 
64 static FTS *ftsp = NULL;		/* current FTS handle */
65 static int ftsopts;			/* options to be used on fts_open */
66 static char *farray[2];			/* array for passing each arg to fts */
67 static FTREE *fthead = NULL;		/* head of linked list of file args */
68 static FTREE *fttail = NULL;		/* tail of linked list of file args */
69 static FTREE *ftcur = NULL;		/* current file arg being processed */
70 static FTSENT *ftent = NULL;		/* current file tree entry */
71 static int ftree_skip;			/* when set skip to next file arg */
72 
73 static int ftree_arg(void);
74 static char *getpathname(char *, int);
75 
76 /*
77  * ftree_start()
78  *	initialize the options passed to fts_open() during this run of pax
79  *	options are based on the selection of pax options by the user
80  *	fts_start() also calls fts_arg() to open the first valid file arg. We
81  *	also attempt to reset directory access times when -t (tflag) is set.
82  * Return:
83  *	0 if there is at least one valid file arg to process, -1 otherwise
84  */
85 
86 int
87 ftree_start(void)
88 {
89 	/*
90 	 * set up the operation mode of fts, open the first file arg. We must
91 	 * use FTS_NOCHDIR, as the user may have to open multiple archives and
92 	 * if fts did a chdir off into the boondocks, we may create an archive
93 	 * volume in an place where the user did not expect to.
94 	 */
95 	ftsopts = FTS_NOCHDIR;
96 
97 	/*
98 	 * optional user flags that effect file traversal
99 	 * -H command line symlink follow only (half follow)
100 	 * -L follow sylinks (logical)
101 	 * -P do not follow sylinks (physical). This is the default.
102 	 * -X do not cross over mount points
103 	 * -t preserve access times on files read.
104 	 * -n select only the first member of a file tree when a match is found
105 	 * -d do not extract subtrees rooted at a directory arg.
106 	 */
107 	if (Lflag)
108 		ftsopts |= FTS_LOGICAL;
109 	else
110 		ftsopts |= FTS_PHYSICAL;
111 	if (Hflag)
112 		ftsopts |= FTS_COMFOLLOW;
113 	if (Xflag)
114 		ftsopts |= FTS_XDEV;
115 
116 	if ((fthead == NULL) && ((farray[0] = malloc(PAXPATHLEN+2)) == NULL)) {
117 		paxwarn(1, "Unable to allocate memory for file name buffer");
118 		return(-1);
119 	}
120 
121 	if (ftree_arg() < 0)
122 		return(-1);
123 	if (tflag && (atdir_start() < 0))
124 		return(-1);
125 	return(0);
126 }
127 
128 /*
129  * ftree_add()
130  *	add the arg to the linked list of files to process. Each will be
131  *	processed by fts one at a time
132  * Return:
133  *	0 if added to the linked list, -1 if failed
134  */
135 
136 int
137 ftree_add(char *str, int chflg)
138 {
139 	FTREE *ft;
140 	int len;
141 
142 	/*
143 	 * simple check for bad args
144 	 */
145 	if ((str == NULL) || (*str == '\0')) {
146 		paxwarn(0, "Invalid file name argument");
147 		return(-1);
148 	}
149 
150 	/*
151 	 * allocate FTREE node and add to the end of the linked list (args are
152 	 * processed in the same order they were passed to pax). Get rid of any
153 	 * trailing / the user may pass us. (watch out for / by itself).
154 	 */
155 	if ((ft = (FTREE *)malloc(sizeof(FTREE))) == NULL) {
156 		paxwarn(0, "Unable to allocate memory for filename");
157 		return(-1);
158 	}
159 
160 	if (((len = strlen(str) - 1) > 0) && (str[len] == '/'))
161 		str[len] = '\0';
162 	ft->fname = str;
163 	ft->refcnt = 0;
164 	ft->newercnt = 0;
165 	ft->chflg = chflg;
166 	ft->fow = NULL;
167 	if (fthead == NULL) {
168 		fttail = fthead = ft;
169 		return(0);
170 	}
171 	fttail->fow = ft;
172 	fttail = ft;
173 	return(0);
174 }
175 
176 /*
177  * ftree_sel()
178  *	this entry has been selected by pax. bump up reference count and handle
179  *	-n and -d processing.
180  */
181 
182 void
183 ftree_sel(ARCHD *arcn)
184 {
185 	/*
186 	 * set reference bit for this pattern. This linked list is only used
187 	 * when file trees are supplied pax as args. The list is not used when
188 	 * the trees are read from stdin.
189 	 */
190 	if (ftcur != NULL)
191 		ftcur->refcnt = 1;
192 
193 	/*
194 	 * if -n we are done with this arg, force a skip to the next arg when
195 	 * pax asks for the next file in next_file().
196 	 * if -d we tell fts only to match the directory (if the arg is a dir)
197 	 * and not the entire file tree rooted at that point.
198 	 */
199 	if (nflag)
200 		ftree_skip = 1;
201 
202 	if (!dflag || (arcn->type != PAX_DIR))
203 		return;
204 
205 	if (ftent != NULL)
206 		(void)fts_set(ftsp, ftent, FTS_SKIP);
207 }
208 
209 /*
210  * ftree_skipped_newer()
211  *	file has been skipped because a newer file exists and -u/-D given
212  */
213 
214 void
215 ftree_skipped_newer(ARCHD *arcn)
216 {
217 	/* skipped due to -u/-D, mark accordingly */
218 	if (ftcur != NULL)
219 		ftcur->newercnt = 1;
220 }
221 
222 /*
223  * ftree_chk()
224  *	called at end on pax execution. Prints all those file args that did not
225  *	have a selected member (reference count still 0)
226  */
227 
228 void
229 ftree_chk(void)
230 {
231 	FTREE *ft;
232 	int wban = 0;
233 
234 	/*
235 	 * make sure all dir access times were reset.
236 	 */
237 	if (tflag)
238 		atdir_end();
239 
240 	/*
241 	 * walk down list and check reference count. Print out those members
242 	 * that never had a match
243 	 */
244 	for (ft = fthead; ft != NULL; ft = ft->fow) {
245 		if ((ft->refcnt > 0) || ft->newercnt > 0 || ft->chflg)
246 			continue;
247 		if (wban == 0) {
248 			paxwarn(1,"WARNING! These file names were not selected:");
249 			++wban;
250 		}
251 		(void)fprintf(stderr, "%s\n", ft->fname);
252 	}
253 }
254 
255 /*
256  * ftree_arg()
257  *	Get the next file arg for fts to process. Can be from either the linked
258  *	list or read from stdin when the user did not them as args to pax. Each
259  *	arg is processed until the first successful fts_open().
260  * Return:
261  *	0 when the next arg is ready to go, -1 if out of file args (or EOF on
262  *	stdin).
263  */
264 
265 static int
266 ftree_arg(void)
267 {
268 
269 	/*
270 	 * close off the current file tree
271 	 */
272 	if (ftsp != NULL) {
273 		(void)fts_close(ftsp);
274 		ftsp = NULL;
275 	}
276 
277 	/*
278 	 * keep looping until we get a valid file tree to process. Stop when we
279 	 * reach the end of the list (or get an eof on stdin)
280 	 */
281 	for (;;) {
282 		if (fthead == NULL) {
283 			/*
284 			 * the user didn't supply any args, get the file trees
285 			 * to process from stdin;
286 			 */
287 			if (getpathname(farray[0], PAXPATHLEN+1) == NULL)
288 				return(-1);
289 		} else {
290 			/*
291 			 * the user supplied the file args as arguments to pax
292 			 */
293 			if (ftcur == NULL)
294 				ftcur = fthead;
295 			else if ((ftcur = ftcur->fow) == NULL)
296 				return(-1);
297 			if (ftcur->chflg) {
298 				/* First fchdir() back... */
299 				if (fchdir(cwdfd) < 0) {
300 					syswarn(1, errno,
301 					  "Can't fchdir to starting directory");
302 					return(-1);
303 				}
304 				if (chdir(ftcur->fname) < 0) {
305 					syswarn(1, errno, "Can't chdir to %s",
306 					    ftcur->fname);
307 					return(-1);
308 				}
309 				continue;
310 			} else
311 				farray[0] = ftcur->fname;
312 		}
313 
314 		/*
315 		 * watch it, fts wants the file arg stored in a array of char
316 		 * ptrs, with the last one a null. we use a two element array
317 		 * and set farray[0] to point at the buffer with the file name
318 		 * in it. We cannot pass all the file args to fts at one shot
319 		 * as we need to keep a handle on which file arg generates what
320 		 * files (the -n and -d flags need this). If the open is
321 		 * successful, return a 0.
322 		 */
323 		if ((ftsp = fts_open(farray, ftsopts, NULL)) != NULL)
324 			break;
325 	}
326 	return(0);
327 }
328 
329 /*
330  * next_file()
331  *	supplies the next file to process in the supplied archd structure.
332  * Return:
333  *	0 when contents of arcn have been set with the next file, -1 when done.
334  */
335 
336 int
337 next_file(ARCHD *arcn)
338 {
339 	int cnt;
340 	time_t atime;
341 	time_t mtime;
342 
343 	/*
344 	 * ftree_sel() might have set the ftree_skip flag if the user has the
345 	 * -n option and a file was selected from this file arg tree. (-n says
346 	 * only one member is matched for each pattern) ftree_skip being 1
347 	 * forces us to go to the next arg now.
348 	 */
349 	if (ftree_skip) {
350 		/*
351 		 * clear and go to next arg
352 		 */
353 		ftree_skip = 0;
354 		if (ftree_arg() < 0)
355 			return(-1);
356 	}
357 
358 	/*
359 	 * loop until we get a valid file to process
360 	 */
361 	for (;;) {
362 		if ((ftent = fts_read(ftsp)) == NULL) {
363 			if (errno)
364 				syswarn(1, errno, "next_file");
365 			/*
366 			 * out of files in this tree, go to next arg, if none
367 			 * we are done
368 			 */
369 			if (ftree_arg() < 0)
370 				return(-1);
371 			continue;
372 		}
373 
374 		/*
375 		 * handle each type of fts_read() flag
376 		 */
377 		switch (ftent->fts_info) {
378 		case FTS_D:
379 		case FTS_DEFAULT:
380 		case FTS_F:
381 		case FTS_SL:
382 		case FTS_SLNONE:
383 			/*
384 			 * these are all ok
385 			 */
386 			break;
387 		case FTS_DP:
388 			/*
389 			 * already saw this directory. If the user wants file
390 			 * access times reset, we use this to restore the
391 			 * access time for this directory since this is the
392 			 * last time we will see it in this file subtree
393 			 * remember to force the time (this is -t on a read
394 			 * directory, not a created directory).
395 			 */
396 			if (!tflag || (get_atdir(ftent->fts_statp->st_dev,
397 			    ftent->fts_statp->st_ino, &mtime, &atime) < 0))
398 				continue;
399 			set_ftime(ftent->fts_path, mtime, atime, 1);
400 			continue;
401 		case FTS_DC:
402 			/*
403 			 * fts claims a file system cycle
404 			 */
405 			paxwarn(1,"File system cycle found at %s",ftent->fts_path);
406 			continue;
407 		case FTS_DNR:
408 			syswarn(1, ftent->fts_errno,
409 			    "Unable to read directory %s", ftent->fts_path);
410 			continue;
411 		case FTS_ERR:
412 			syswarn(1, ftent->fts_errno,
413 			    "File system traversal error");
414 			continue;
415 		case FTS_NS:
416 		case FTS_NSOK:
417 			syswarn(1, ftent->fts_errno,
418 			    "Unable to access %s", ftent->fts_path);
419 			continue;
420 		}
421 
422 		/*
423 		 * ok got a file tree node to process. copy info into arcn
424 		 * structure (initialize as required)
425 		 */
426 		arcn->skip = 0;
427 		arcn->pad = 0;
428 		arcn->ln_nlen = 0;
429 		arcn->ln_name[0] = '\0';
430 		memcpy(&arcn->sb, ftent->fts_statp, sizeof(arcn->sb));
431 
432 		/*
433 		 * file type based set up and copy into the arcn struct
434 		 * SIDE NOTE:
435 		 * we try to reset the access time on all files and directories
436 		 * we may read when the -t flag is specified. files are reset
437 		 * when we close them after copying. we reset the directories
438 		 * when we are done with their file tree (we also clean up at
439 		 * end in case we cut short a file tree traversal). However
440 		 * there is no way to reset access times on symlinks.
441 		 */
442 		switch (S_IFMT & arcn->sb.st_mode) {
443 		case S_IFDIR:
444 			arcn->type = PAX_DIR;
445 			if (!tflag)
446 				break;
447 			add_atdir(ftent->fts_path, arcn->sb.st_dev,
448 			    arcn->sb.st_ino, arcn->sb.st_mtime,
449 			    arcn->sb.st_atime);
450 			break;
451 		case S_IFCHR:
452 			arcn->type = PAX_CHR;
453 			break;
454 		case S_IFBLK:
455 			arcn->type = PAX_BLK;
456 			break;
457 		case S_IFREG:
458 			/*
459 			 * only regular files with have data to store on the
460 			 * archive. all others will store a zero length skip.
461 			 * the skip field is used by pax for actual data it has
462 			 * to read (or skip over).
463 			 */
464 			arcn->type = PAX_REG;
465 			arcn->skip = arcn->sb.st_size;
466 			break;
467 		case S_IFLNK:
468 			arcn->type = PAX_SLK;
469 			/*
470 			 * have to read the symlink path from the file
471 			 */
472 			if ((cnt = readlink(ftent->fts_path, arcn->ln_name,
473 			    PAXPATHLEN)) < 0) {
474 				syswarn(1, errno, "Unable to read symlink %s",
475 				    ftent->fts_path);
476 				continue;
477 			}
478 			/*
479 			 * set link name length, watch out readlink does not
480 			 * always NUL terminate the link path
481 			 */
482 			arcn->ln_name[cnt] = '\0';
483 			arcn->ln_nlen = cnt;
484 			break;
485 		case S_IFSOCK:
486 			/*
487 			 * under BSD storing a socket is senseless but we will
488 			 * let the format specific write function make the
489 			 * decision of what to do with it.
490 			 */
491 			arcn->type = PAX_SCK;
492 			break;
493 		case S_IFIFO:
494 			arcn->type = PAX_FIF;
495 			break;
496 		}
497 		break;
498 	}
499 
500 	/*
501 	 * copy file name, set file name length
502 	 */
503 	arcn->nlen = strlcpy(arcn->name, ftent->fts_path, sizeof(arcn->name));
504 	if (arcn->nlen >= sizeof(arcn->name))
505 		arcn->nlen = sizeof(arcn->name) - 1; /* XXX truncate? */
506 	arcn->org_name = ftent->fts_path;
507 	return(0);
508 }
509 
510 /*
511  * getpathname()
512  *	Reads a pathname from stdin, handling NUL- or newline-termination.
513  * Return:
514  *	NULL at end of file, otherwise the NUL-terminated buffer.
515  */
516 
517 static char *
518 getpathname(char *buf, int buflen)
519 {
520 	char *bp, *ep;
521 	int ch, term;
522 
523 	if (zeroflag) {
524 		/*
525 		 * Read a NUL-terminated pathname, being especially
526 		 * paranoid about proper termination and pathname length.
527 		 */
528 		for (bp = buf, ep = buf + buflen; bp < ep; bp++) {
529 			if ((ch = getchar()) == EOF) {
530 				if (bp != buf)
531 					paxwarn(1, "Ignoring unterminated "
532 					    "pathname at EOF");
533 				return(NULL);
534 			}
535 			if ((*bp = ch) == '\0')
536 				return(buf);
537 		}
538 		/* Too long - skip this path */
539 		*--bp = '\0';
540 		term = '\0';
541 	} else {
542 		if (fgets(buf, buflen, stdin) == NULL)
543 			return(NULL);
544 		if ((bp = strchr(buf, '\n')) != NULL || feof(stdin)) {
545 			if (bp != NULL)
546 				*bp = '\0';
547 			return(buf);
548 		}
549 		/* Too long - skip this path */
550 		term = '\n';
551 	}
552 	while ((ch = getchar()) != term && ch != EOF)
553 		;
554 	paxwarn(1, "Ignoring too-long pathname: %s", buf);
555 	return(NULL);
556 }
557