xref: /freebsd/usr.sbin/makefs/mtree.c (revision 396c556d77189a5c474d35cec6f44a762e310b7d) 
1 /*-
2  * Copyright (c) 2011 Marcel Moolenaar
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24  */
25 
26 #include <sys/cdefs.h>
27 __FBSDID("$FreeBSD$");
28 
29 #include <sys/param.h>
30 #include <sys/queue.h>
31 #include <sys/sbuf.h>
32 #include <sys/stat.h>
33 #include <sys/types.h>
34 #include <assert.h>
35 #include <errno.h>
36 #include <fcntl.h>
37 #include <grp.h>
38 #include <inttypes.h>
39 #include <pwd.h>
40 #include <stdarg.h>
41 #include <stdbool.h>
42 #include <stddef.h>
43 #include <stdio.h>
44 #include <stdlib.h>
45 #include <string.h>
46 #include <strings.h>
47 #include <time.h>
48 #include <unistd.h>
49 #include <util.h>
50 #include <vis.h>
51 
52 #include "makefs.h"
53 
54 #ifndef ENOATTR
55 #define	ENOATTR	ENOMSG
56 #endif
57 
58 #define	IS_DOT(nm)	((nm)[0] == '.' && (nm)[1] == '\0')
59 #define	IS_DOTDOT(nm)	((nm)[0] == '.' && (nm)[1] == '.' && (nm)[2] == '\0')
60 
61 struct mtree_fileinfo {
62 	SLIST_ENTRY(mtree_fileinfo) next;
63 	FILE *fp;
64 	const char *name;
65 	u_int line;
66 };
67 
68 /* Global state used while parsing. */
69 static SLIST_HEAD(, mtree_fileinfo) mtree_fileinfo =
70     SLIST_HEAD_INITIALIZER(mtree_fileinfo);
71 static fsnode *mtree_root;
72 static fsnode *mtree_current;
73 static fsnode mtree_global;
74 static fsinode mtree_global_inode;
75 static u_int errors, warnings;
76 
77 static void mtree_error(const char *, ...) __printflike(1, 2);
78 static void mtree_warning(const char *, ...) __printflike(1, 2);
79 
80 static int
81 mtree_file_push(const char *name, FILE *fp)
82 {
83 	struct mtree_fileinfo *fi;
84 
85 	fi = emalloc(sizeof(*fi));
86 	if (strcmp(name, "-") == 0)
87 		fi->name = estrdup("(stdin)");
88 	else
89 		fi->name = estrdup(name);
90 	if (fi->name == NULL) {
91 		free(fi);
92 		return (ENOMEM);
93 	}
94 
95 	fi->fp = fp;
96 	fi->line = 0;
97 
98 	SLIST_INSERT_HEAD(&mtree_fileinfo, fi, next);
99 	return (0);
100 }
101 
102 static void
103 mtree_print(const char *msgtype, const char *fmt, va_list ap)
104 {
105 	struct mtree_fileinfo *fi;
106 
107 	if (msgtype != NULL) {
108 		fi = SLIST_FIRST(&mtree_fileinfo);
109 		if (fi != NULL)
110 			fprintf(stderr, "%s:%u: ", fi->name, fi->line);
111 		fprintf(stderr, "%s: ", msgtype);
112 	}
113 	vfprintf(stderr, fmt, ap);
114 }
115 
116 static void
117 mtree_error(const char *fmt, ...)
118 {
119 	va_list ap;
120 
121 	va_start(ap, fmt);
122 	mtree_print("error", fmt, ap);
123 	va_end(ap);
124 
125 	errors++;
126 	fputc('\n', stderr);
127 }
128 
129 static void
130 mtree_warning(const char *fmt, ...)
131 {
132 	va_list ap;
133 
134 	va_start(ap, fmt);
135 	mtree_print("warning", fmt, ap);
136 	va_end(ap);
137 
138 	warnings++;
139 	fputc('\n', stderr);
140 }
141 
142 #ifndef MAKEFS_MAX_TREE_DEPTH
143 # define MAKEFS_MAX_TREE_DEPTH (MAXPATHLEN/2)
144 #endif
145 
146 /* construct path to node->name */
147 static char *
148 mtree_file_path(fsnode *node)
149 {
150 	fsnode *pnode;
151 	struct sbuf *sb;
152 	char *res, *rp[MAKEFS_MAX_TREE_DEPTH];
153 	int depth;
154 
155 	depth = 0;
156 	rp[depth] = node->name;
157 	for (pnode = node->parent; pnode && depth < MAKEFS_MAX_TREE_DEPTH - 1;
158 	     pnode = pnode->parent) {
159 		if (strcmp(pnode->name, ".") == 0)
160 			break;
161 		rp[++depth] = pnode->name;
162 	}
163 
164 	sb = sbuf_new_auto();
165 	if (sb == NULL) {
166 		errno = ENOMEM;
167 		return (NULL);
168 	}
169 	while (depth > 0) {
170 		sbuf_cat(sb, rp[depth--]);
171 		sbuf_putc(sb, '/');
172 	}
173 	sbuf_cat(sb, rp[depth]);
174 	sbuf_finish(sb);
175 	res = estrdup(sbuf_data(sb));
176 	sbuf_delete(sb);
177 	if (res == NULL)
178 		errno = ENOMEM;
179 	return res;
180 
181 }
182 
183 /* mtree_resolve() sets errno to indicate why NULL was returned. */
184 static char *
185 mtree_resolve(const char *spec, int *istemp)
186 {
187 	struct sbuf *sb;
188 	char *res, *var = NULL;
189 	const char *base, *p, *v;
190 	size_t len;
191 	int c, error, quoted, subst;
192 
193 	len = strlen(spec);
194 	if (len == 0) {
195 		errno = EINVAL;
196 		return (NULL);
197 	}
198 
199 	c = (len > 1) ? (spec[0] == spec[len - 1]) ? spec[0] : 0 : 0;
200 	*istemp = (c == '`') ? 1 : 0;
201 	subst = (c == '`' || c == '"') ? 1 : 0;
202 	quoted = (subst || c == '\'') ? 1 : 0;
203 
204 	if (!subst) {
205 		res = estrdup(spec + quoted);
206 		if (quoted)
207 			res[len - 2] = '\0';
208 		return (res);
209 	}
210 
211 	sb = sbuf_new_auto();
212 	if (sb == NULL) {
213 		errno = ENOMEM;
214 		return (NULL);
215 	}
216 
217 	base = spec + 1;
218 	len -= 2;
219 	error = 0;
220 	while (len > 0) {
221 		p = strchr(base, '$');
222 		if (p == NULL) {
223 			sbuf_bcat(sb, base, len);
224 			base += len;
225 			len = 0;
226 			continue;
227 		}
228 		/* The following is safe. spec always starts with a quote. */
229 		if (p[-1] == '\\')
230 			p--;
231 		if (base != p) {
232 			sbuf_bcat(sb, base, p - base);
233 			len -= p - base;
234 			base = p;
235 		}
236 		if (*p == '\\') {
237 			sbuf_putc(sb, '$');
238 			base += 2;
239 			len -= 2;
240 			continue;
241 		}
242 		/* Skip the '$'. */
243 		base++;
244 		len--;
245 		/* Handle ${X} vs $X. */
246 		v = base;
247 		if (*base == '{') {
248 			p = strchr(v, '}');
249 			if (p == NULL)
250 				p = v;
251 		} else
252 			p = v;
253 		len -= (p + 1) - base;
254 		base = p + 1;
255 
256 		if (v == p) {
257 			sbuf_putc(sb, *v);
258 			continue;
259 		}
260 
261 		error = ENOMEM;
262 		var = ecalloc(p - v, 1);
263 		memcpy(var, v + 1, p - v - 1);
264 		if (strcmp(var, ".CURDIR") == 0) {
265 			res = getcwd(NULL, 0);
266 			if (res == NULL)
267 				break;
268 		} else if (strcmp(var, ".PROG") == 0) {
269 			res = estrdup(getprogname());
270 		} else {
271 			v = getenv(var);
272 			if (v != NULL) {
273 				res = estrdup(v);
274 			} else
275 				res = NULL;
276 		}
277 		error = 0;
278 
279 		if (res != NULL) {
280 			sbuf_cat(sb, res);
281 			free(res);
282 		}
283 		free(var);
284 		var = NULL;
285 	}
286 
287 	free(var);
288 	sbuf_finish(sb);
289 	res = (error == 0) ? strdup(sbuf_data(sb)) : NULL;
290 	sbuf_delete(sb);
291 	if (res == NULL)
292 		errno = ENOMEM;
293 	return (res);
294 }
295 
296 static int
297 skip_over(FILE *fp, const char *cs)
298 {
299 	int c;
300 
301 	c = getc(fp);
302 	while (c != EOF && strchr(cs, c) != NULL)
303 		c = getc(fp);
304 	if (c != EOF) {
305 		ungetc(c, fp);
306 		return (0);
307 	}
308 	return (ferror(fp) ? errno : -1);
309 }
310 
311 static int
312 skip_to(FILE *fp, const char *cs)
313 {
314 	int c;
315 
316 	c = getc(fp);
317 	while (c != EOF && strchr(cs, c) == NULL)
318 		c = getc(fp);
319 	if (c != EOF) {
320 		ungetc(c, fp);
321 		return (0);
322 	}
323 	return (ferror(fp) ? errno : -1);
324 }
325 
326 static int
327 read_word(FILE *fp, char *buf, size_t bufsz)
328 {
329 	struct mtree_fileinfo *fi;
330 	size_t idx, qidx;
331 	int c, done, error, esc, qlvl;
332 
333 	if (bufsz == 0)
334 		return (EINVAL);
335 
336 	done = 0;
337 	esc = 0;
338 	idx = 0;
339 	qidx = -1;
340 	qlvl = 0;
341 	do {
342 		c = getc(fp);
343 		switch (c) {
344 		case EOF:
345 			buf[idx] = '\0';
346 			error = ferror(fp) ? errno : -1;
347 			if (error == -1)
348 				mtree_error("unexpected end of file");
349 			return (error);
350 		case '#':		/* comment -- skip to end of line. */
351 			if (!esc) {
352 				error = skip_to(fp, "\n");
353 				if (!error)
354 					continue;
355 			}
356 			break;
357 		case '\\':
358 			esc++;
359 			break;
360 		case '`':
361 		case '\'':
362 		case '"':
363 			if (esc)
364 				break;
365 			if (qlvl == 0) {
366 				qlvl++;
367 				qidx = idx;
368 			} else if (c == buf[qidx]) {
369 				qlvl--;
370 				if (qlvl > 0) {
371 					do {
372 						qidx--;
373 					} while (buf[qidx] != '`' &&
374 					    buf[qidx] != '\'' &&
375 					    buf[qidx] != '"');
376 				} else
377 					qidx = -1;
378 			} else {
379 				qlvl++;
380 				qidx = idx;
381 			}
382 			break;
383 		case ' ':
384 		case '\t':
385 		case '\n':
386 			if (!esc && qlvl == 0) {
387 				ungetc(c, fp);
388 				c = '\0';
389 				done = 1;
390 				break;
391 			}
392 			if (c == '\n') {
393 				/*
394 				 * We going to eat the newline ourselves.
395 				 */
396 				if (qlvl > 0)
397 					mtree_warning("quoted word straddles "
398 					    "onto next line.");
399 				fi = SLIST_FIRST(&mtree_fileinfo);
400 				fi->line++;
401 			}
402 			break;
403 		default:
404 			if (esc)
405 				buf[idx++] = '\\';
406 			break;
407 		}
408 		buf[idx++] = c;
409 		esc = 0;
410 	} while (idx < bufsz && !done);
411 
412 	if (idx >= bufsz) {
413 		mtree_error("word too long to fit buffer (max %zu characters)",
414 		    bufsz);
415 		skip_to(fp, " \t\n");
416 	}
417 	return (0);
418 }
419 
420 static fsnode *
421 create_node(const char *name, u_int type, fsnode *parent, fsnode *global)
422 {
423 	fsnode *n;
424 
425 	n = ecalloc(1, sizeof(*n));
426 	n->name = estrdup(name);
427 	n->type = (type == 0) ? global->type : type;
428 	n->parent = parent;
429 
430 	n->inode = ecalloc(1, sizeof(*n->inode));
431 
432 	/* Assign global options/defaults. */
433 	memcpy(n->inode, global->inode, sizeof(*n->inode));
434 	n->inode->st.st_mode = (n->inode->st.st_mode & ~S_IFMT) | n->type;
435 
436 	if (n->type == S_IFLNK)
437 		n->symlink = global->symlink;
438 	else if (n->type == S_IFREG)
439 		n->contents = global->contents;
440 
441 	return (n);
442 }
443 
444 static void
445 destroy_node(fsnode *n)
446 {
447 
448 	assert(n != NULL);
449 	assert(n->name != NULL);
450 	assert(n->inode != NULL);
451 
452 	free(n->inode);
453 	free(n->name);
454 	free(n);
455 }
456 
457 static int
458 read_number(const char *tok, u_int base, intmax_t *res, intmax_t min,
459     intmax_t max)
460 {
461 	char *end;
462 	intmax_t val;
463 
464 	val = strtoimax(tok, &end, base);
465 	if (end == tok || end[0] != '\0')
466 		return (EINVAL);
467 	if (val < min || val > max)
468 		return (EDOM);
469 	*res = val;
470 	return (0);
471 }
472 
473 static int
474 read_mtree_keywords(FILE *fp, fsnode *node)
475 {
476 	char keyword[PATH_MAX];
477 	char *name, *p, *value;
478 	gid_t gid;
479 	uid_t uid;
480 	struct stat *st, sb;
481 	intmax_t num;
482 	u_long flset, flclr;
483 	int error, istemp;
484 	uint32_t type;
485 
486 	st = &node->inode->st;
487 	do {
488 		error = skip_over(fp, " \t");
489 		if (error)
490 			break;
491 
492 		error = read_word(fp, keyword, sizeof(keyword));
493 		if (error)
494 			break;
495 
496 		if (keyword[0] == '\0')
497 			break;
498 
499 		value = strchr(keyword, '=');
500 		if (value != NULL)
501 			*value++ = '\0';
502 
503 		/*
504 		 * We use EINVAL, ENOATTR, ENOSYS and ENXIO to signal
505 		 * certain conditions:
506 		 *   EINVAL -	Value provided for a keyword that does
507 		 *		not take a value. The value is ignored.
508 		 *   ENOATTR -	Value missing for a keyword that needs
509 		 *		a value. The keyword is ignored.
510 		 *   ENOSYS -	Unsupported keyword encountered. The
511 		 *		keyword is ignored.
512 		 *   ENXIO -	Value provided for a keyword that does
513 		 *		not take a value. The value is ignored.
514 		 */
515 		switch (keyword[0]) {
516 		case 'c':
517 			if (strcmp(keyword, "contents") == 0) {
518 				if (value == NULL) {
519 					error = ENOATTR;
520 					break;
521 				}
522 				node->contents = estrdup(value);
523 			} else
524 				error = ENOSYS;
525 			break;
526 		case 'f':
527 			if (strcmp(keyword, "flags") == 0) {
528 				if (value == NULL) {
529 					error = ENOATTR;
530 					break;
531 				}
532 				flset = flclr = 0;
533 				if (!strtofflags(&value, &flset, &flclr)) {
534 					st->st_flags &= ~flclr;
535 					st->st_flags |= flset;
536 				} else
537 					error = errno;
538 			} else
539 				error = ENOSYS;
540 			break;
541 		case 'g':
542 			if (strcmp(keyword, "gid") == 0) {
543 				if (value == NULL) {
544 					error = ENOATTR;
545 					break;
546 				}
547 				error = read_number(value, 10, &num,
548 				    0, UINT_MAX);
549 				if (!error)
550 					st->st_gid = num;
551 			} else if (strcmp(keyword, "gname") == 0) {
552 				if (value == NULL) {
553 					error = ENOATTR;
554 					break;
555 				}
556 				if (gid_from_group(value, &gid) == 0)
557 					st->st_gid = gid;
558 				else
559 					error = EINVAL;
560 			} else
561 				error = ENOSYS;
562 			break;
563 		case 'l':
564 			if (strcmp(keyword, "link") == 0) {
565 				if (value == NULL) {
566 					error = ENOATTR;
567 					break;
568 				}
569 				node->symlink = emalloc(strlen(value) + 1);
570 				if (node->symlink == NULL) {
571 					error = errno;
572 					break;
573 				}
574 				if (strunvis(node->symlink, value) < 0) {
575 					error = errno;
576 					break;
577 				}
578 			} else
579 				error = ENOSYS;
580 			break;
581 		case 'm':
582 			if (strcmp(keyword, "mode") == 0) {
583 				if (value == NULL) {
584 					error = ENOATTR;
585 					break;
586 				}
587 				if (value[0] >= '0' && value[0] <= '9') {
588 					error = read_number(value, 8, &num,
589 					    0, 07777);
590 					if (!error) {
591 						st->st_mode &= S_IFMT;
592 						st->st_mode |= num;
593 					}
594 				} else {
595 					/* Symbolic mode not supported. */
596 					error = EINVAL;
597 					break;
598 				}
599 			} else
600 				error = ENOSYS;
601 			break;
602 		case 'o':
603 			if (strcmp(keyword, "optional") == 0) {
604 				if (value != NULL)
605 					error = ENXIO;
606 				node->flags |= FSNODE_F_OPTIONAL;
607 			} else
608 				error = ENOSYS;
609 			break;
610 		case 's':
611 			if (strcmp(keyword, "size") == 0) {
612 				if (value == NULL) {
613 					error = ENOATTR;
614 					break;
615 				}
616 				error = read_number(value, 10, &num,
617 				    0, INTMAX_MAX);
618 				if (!error)
619 					st->st_size = num;
620 			} else
621 				error = ENOSYS;
622 			break;
623 		case 't':
624 			if (strcmp(keyword, "time") == 0) {
625 				if (value == NULL) {
626 					error = ENOATTR;
627 					break;
628 				}
629 				p = strchr(value, '.');
630 				if (p != NULL)
631 					*p++ = '\0';
632 				error = read_number(value, 10, &num, 0,
633 				    INTMAX_MAX);
634 				if (error)
635 					break;
636 				st->st_atime = num;
637 				st->st_ctime = num;
638 				st->st_mtime = num;
639 				if (p == NULL)
640 					break;
641 				error = read_number(p, 10, &num, 0,
642 				    INTMAX_MAX);
643 				if (error)
644 					break;
645 				if (num != 0)
646 					error = EINVAL;
647 			} else if (strcmp(keyword, "type") == 0) {
648 				if (value == NULL) {
649 					error = ENOATTR;
650 					break;
651 				}
652 				if (strcmp(value, "dir") == 0)
653 					node->type = S_IFDIR;
654 				else if (strcmp(value, "file") == 0)
655 					node->type = S_IFREG;
656 				else if (strcmp(value, "link") == 0)
657 					node->type = S_IFLNK;
658 				else
659 					error = EINVAL;
660 			} else
661 				error = ENOSYS;
662 			break;
663 		case 'u':
664 			if (strcmp(keyword, "uid") == 0) {
665 				if (value == NULL) {
666 					error = ENOATTR;
667 					break;
668 				}
669 				error = read_number(value, 10, &num,
670 				    0, UINT_MAX);
671 				if (!error)
672 					st->st_uid = num;
673 			} else if (strcmp(keyword, "uname") == 0) {
674 				if (value == NULL) {
675 					error = ENOATTR;
676 					break;
677 				}
678 				if (uid_from_user(value, &uid) == 0)
679 					st->st_uid = uid;
680 				else
681 					error = EINVAL;
682 			} else
683 				error = ENOSYS;
684 			break;
685 		default:
686 			error = ENOSYS;
687 			break;
688 		}
689 
690 		switch (error) {
691 		case EINVAL:
692 			mtree_error("%s: invalid value '%s'", keyword, value);
693 			break;
694 		case ENOATTR:
695 			mtree_error("%s: keyword needs a value", keyword);
696 			break;
697 		case ENOSYS:
698 			mtree_warning("%s: unsupported keyword", keyword);
699 			break;
700 		case ENXIO:
701 			mtree_error("%s: keyword does not take a value",
702 			    keyword);
703 			break;
704 		}
705 	} while (1);
706 
707 	if (error)
708 		return (error);
709 
710 	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
711 
712 	/* Nothing more to do for the global defaults. */
713 	if (node->name == NULL)
714 		return (0);
715 
716 	/*
717 	 * Be intelligent about the file type.
718 	 */
719 	if (node->contents != NULL) {
720 		if (node->symlink != NULL) {
721 			mtree_error("%s: both link and contents keywords "
722 			    "defined", node->name);
723 			return (0);
724 		}
725 		type = S_IFREG;
726 	} else if (node->type != 0) {
727 		type = node->type;
728 		if (type == S_IFREG) {
729 			/* the named path is the default contents */
730 			node->contents = mtree_file_path(node);
731 		}
732 	} else
733 		type = (node->symlink != NULL) ? S_IFLNK : S_IFDIR;
734 
735 	if (node->type == 0)
736 		node->type = type;
737 
738 	if (node->type != type) {
739 		mtree_error("%s: file type and defined keywords to not match",
740 		    node->name);
741 		return (0);
742 	}
743 
744 	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
745 
746 	if (node->contents == NULL)
747 		return (0);
748 
749 	name = mtree_resolve(node->contents, &istemp);
750 	if (name == NULL)
751 		return (errno);
752 
753 	if (stat(name, &sb) != 0) {
754 		mtree_error("%s: contents file '%s' not found", node->name,
755 		    name);
756 		free(name);
757 		return (0);
758 	}
759 
760 	/*
761          * Check for hardlinks. If the contents key is used, then the check
762          * will only trigger if the contents file is a link even if it is used
763          * by more than one file
764 	 */
765 	if (sb.st_nlink > 1) {
766 		fsinode *curino;
767 
768 		st->st_ino = sb.st_ino;
769 		st->st_dev = sb.st_dev;
770 		curino = link_check(node->inode);
771 		if (curino != NULL) {
772 			free(node->inode);
773 			node->inode = curino;
774 			node->inode->nlink++;
775 		}
776 	}
777 
778 	free(node->contents);
779 	node->contents = name;
780 	st->st_size = sb.st_size;
781 	return (0);
782 }
783 
784 static int
785 read_mtree_command(FILE *fp)
786 {
787 	char cmd[10];
788 	int error;
789 
790 	error = read_word(fp, cmd, sizeof(cmd));
791 	if (error)
792 		goto out;
793 
794 	error = read_mtree_keywords(fp, &mtree_global);
795 
796  out:
797 	skip_to(fp, "\n");
798 	(void)getc(fp);
799 	return (error);
800 }
801 
802 static int
803 read_mtree_spec1(FILE *fp, bool def, const char *name)
804 {
805 	fsnode *last, *node, *parent;
806 	u_int type;
807 	int error;
808 
809 	assert(name[0] != '\0');
810 
811 	/*
812 	 * Treat '..' specially, because it only changes our current
813 	 * directory. We don't create a node for it. We simply ignore
814 	 * any keywords that may appear on the line as well.
815 	 * Going up a directory is a little non-obvious. A directory
816 	 * node has a corresponding '.' child. The parent of '.' is
817 	 * not the '.' node of the parent directory, but the directory
818 	 * node within the parent to which the child relates. However,
819 	 * going up a directory means we need to find the '.' node to
820 	 * which the directoy node is linked.  This we can do via the
821 	 * first * pointer, because '.' is always the first entry in a
822 	 * directory.
823 	 */
824 	if (IS_DOTDOT(name)) {
825 		/* This deals with NULL pointers as well. */
826 		if (mtree_current == mtree_root) {
827 			mtree_warning("ignoring .. in root directory");
828 			return (0);
829 		}
830 
831 		node = mtree_current;
832 
833 		assert(node != NULL);
834 		assert(IS_DOT(node->name));
835 		assert(node->first == node);
836 
837 		/* Get the corresponding directory node in the parent. */
838 		node = mtree_current->parent;
839 
840 		assert(node != NULL);
841 		assert(!IS_DOT(node->name));
842 
843 		node = node->first;
844 
845 		assert(node != NULL);
846 		assert(IS_DOT(node->name));
847 		assert(node->first == node);
848 
849 		mtree_current = node;
850 		return (0);
851 	}
852 
853 	/*
854 	 * If we don't have a current directory and the first specification
855 	 * (either implicit or defined) is not '.', then we need to create
856 	 * a '.' node first (using a recursive call).
857 	 */
858 	if (!IS_DOT(name) && mtree_current == NULL) {
859 		error = read_mtree_spec1(fp, false, ".");
860 		if (error)
861 			return (error);
862 	}
863 
864 	/*
865 	 * Lookup the name in the current directory (if we have a current
866 	 * directory) to make sure we do not create multiple nodes for the
867 	 * same component. For non-definitions, if we find a node with the
868 	 * same name, simply change the current directory. For definitions
869 	 * more happens.
870 	 */
871 	last = NULL;
872 	node = mtree_current;
873 	while (node != NULL) {
874 		assert(node->first == mtree_current);
875 
876 		if (strcmp(name, node->name) == 0) {
877 			if (def == true) {
878 				if (!dupsok)
879 					mtree_error(
880 					    "duplicate definition of %s",
881 					    name);
882 				else
883 					mtree_warning(
884 					    "duplicate definition of %s",
885 					    name);
886 				return (0);
887 			}
888 
889 			if (node->type != S_IFDIR) {
890 				mtree_error("%s is not a directory", name);
891 				return (0);
892 			}
893 
894 			assert(!IS_DOT(name));
895 
896 			node = node->child;
897 
898 			assert(node != NULL);
899 			assert(IS_DOT(node->name));
900 
901 			mtree_current = node;
902 			return (0);
903 		}
904 
905 		last = node;
906 		node = last->next;
907 	}
908 
909 	parent = (mtree_current != NULL) ? mtree_current->parent : NULL;
910 	type = (def == false || IS_DOT(name)) ? S_IFDIR : 0;
911 	node = create_node(name, type, parent, &mtree_global);
912 	if (node == NULL)
913 		return (ENOMEM);
914 
915 	if (def == true) {
916 		error = read_mtree_keywords(fp, node);
917 		if (error) {
918 			destroy_node(node);
919 			return (error);
920 		}
921 	}
922 
923 	node->first = (mtree_current != NULL) ? mtree_current : node;
924 
925 	if (last != NULL)
926 		last->next = node;
927 
928 	if (node->type != S_IFDIR)
929 		return (0);
930 
931 	if (!IS_DOT(node->name)) {
932 		parent = node;
933 		node = create_node(".", S_IFDIR, parent, parent);
934 		if (node == NULL) {
935 			last->next = NULL;
936 			destroy_node(parent);
937 			return (ENOMEM);
938 		}
939 		parent->child = node;
940 		node->first = node;
941 	}
942 
943 	assert(node != NULL);
944 	assert(IS_DOT(node->name));
945 	assert(node->first == node);
946 
947 	mtree_current = node;
948 	if (mtree_root == NULL)
949 		mtree_root = node;
950 
951 	return (0);
952 }
953 
954 static int
955 read_mtree_spec(FILE *fp)
956 {
957 	char pathspec[PATH_MAX], pathtmp[4*PATH_MAX + 1];
958 	char *cp;
959 	int error;
960 
961 	error = read_word(fp, pathtmp, sizeof(pathtmp));
962 	if (error)
963 		goto out;
964 	if (strnunvis(pathspec, PATH_MAX, pathtmp) == -1) {
965 		error = errno;
966 		goto out;
967 	}
968 	error = 0;
969 
970 	cp = strchr(pathspec, '/');
971 	if (cp != NULL) {
972 		/* Absolute pathname */
973 		mtree_current = mtree_root;
974 
975 		do {
976 			*cp++ = '\0';
977 
978 			/* Disallow '..' as a component. */
979 			if (IS_DOTDOT(pathspec)) {
980 				mtree_error("absolute path cannot contain "
981 				    ".. component");
982 				goto out;
983 			}
984 
985 			/* Ignore multiple adjacent slashes and '.'. */
986 			if (pathspec[0] != '\0' && !IS_DOT(pathspec))
987 				error = read_mtree_spec1(fp, false, pathspec);
988 			memmove(pathspec, cp, strlen(cp) + 1);
989 			cp = strchr(pathspec, '/');
990 		} while (!error && cp != NULL);
991 
992 		/* Disallow '.' and '..' as the last component. */
993 		if (!error && (IS_DOT(pathspec) || IS_DOTDOT(pathspec))) {
994 			mtree_error("absolute path cannot contain . or .. "
995 			    "components");
996 			goto out;
997 		}
998 	}
999 
1000 	/* Ignore absolute specfications that end with a slash. */
1001 	if (!error && pathspec[0] != '\0')
1002 		error = read_mtree_spec1(fp, true, pathspec);
1003 
1004  out:
1005 	skip_to(fp, "\n");
1006 	(void)getc(fp);
1007 	return (error);
1008 }
1009 
1010 fsnode *
1011 read_mtree(const char *fname, fsnode *node)
1012 {
1013 	struct mtree_fileinfo *fi;
1014 	FILE *fp;
1015 	int c, error;
1016 
1017 	/* We do not yet support nesting... */
1018 	assert(node == NULL);
1019 
1020 	if (strcmp(fname, "-") == 0)
1021 		fp = stdin;
1022 	else {
1023 		fp = fopen(fname, "r");
1024 		if (fp == NULL)
1025 			err(1, "Can't open `%s'", fname);
1026 	}
1027 
1028 	error = mtree_file_push(fname, fp);
1029 	if (error)
1030 		goto out;
1031 
1032 	memset(&mtree_global, 0, sizeof(mtree_global));
1033 	memset(&mtree_global_inode, 0, sizeof(mtree_global_inode));
1034 	mtree_global.inode = &mtree_global_inode;
1035 	mtree_global_inode.nlink = 1;
1036 	mtree_global_inode.st.st_nlink = 1;
1037 	mtree_global_inode.st.st_atime = mtree_global_inode.st.st_ctime =
1038 	    mtree_global_inode.st.st_mtime = time(NULL);
1039 	errors = warnings = 0;
1040 
1041 	setgroupent(1);
1042 	setpassent(1);
1043 
1044 	mtree_root = node;
1045 	mtree_current = node;
1046 	do {
1047 		/* Start of a new line... */
1048 		fi = SLIST_FIRST(&mtree_fileinfo);
1049 		fi->line++;
1050 
1051 		error = skip_over(fp, " \t");
1052 		if (error)
1053 			break;
1054 
1055 		c = getc(fp);
1056 		if (c == EOF) {
1057 			error = ferror(fp) ? errno : -1;
1058 			break;
1059 		}
1060 
1061 		switch (c) {
1062 		case '\n':		/* empty line */
1063 			error = 0;
1064 			break;
1065 		case '#':		/* comment -- skip to end of line. */
1066 			error = skip_to(fp, "\n");
1067 			if (!error)
1068 				(void)getc(fp);
1069 			break;
1070 		case '/':		/* special commands */
1071 			error = read_mtree_command(fp);
1072 			break;
1073 		default:		/* specification */
1074 			ungetc(c, fp);
1075 			error = read_mtree_spec(fp);
1076 			break;
1077 		}
1078 	} while (!error);
1079 
1080 	endpwent();
1081 	endgrent();
1082 
1083 	if (error <= 0 && (errors || warnings)) {
1084 		warnx("%u error(s) and %u warning(s) in mtree manifest",
1085 		    errors, warnings);
1086 		if (errors)
1087 			exit(1);
1088 	}
1089 
1090  out:
1091 	if (error > 0)
1092 		errc(1, error, "Error reading mtree file");
1093 
1094 	if (fp != stdin)
1095 		fclose(fp);
1096 
1097 	if (mtree_root != NULL)
1098 		return (mtree_root);
1099 
1100 	/* Handle empty specifications. */
1101 	node = create_node(".", S_IFDIR, NULL, &mtree_global);
1102 	node->first = node;
1103 	return (node);
1104 }
1105