xref: /freebsd/usr.sbin/makefs/mtree.c (revision f37852c17391fdf0e8309bcf684384dd0d854e43) 
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 
51 #include "makefs.h"
52 
53 #ifndef ENOATTR
54 #define	ENOATTR	ENOMSG
55 #endif
56 
57 #define	IS_DOT(nm)	((nm)[0] == '.' && (nm)[1] == '\0')
58 #define	IS_DOTDOT(nm)	((nm)[0] == '.' && (nm)[1] == '.' && (nm)[2] == '\0')
59 
60 struct mtree_fileinfo {
61 	SLIST_ENTRY(mtree_fileinfo) next;
62 	FILE *fp;
63 	const char *name;
64 	u_int line;
65 };
66 
67 /* Global state used while parsing. */
68 static SLIST_HEAD(, mtree_fileinfo) mtree_fileinfo =
69     SLIST_HEAD_INITIALIZER(mtree_fileinfo);
70 static fsnode *mtree_root;
71 static fsnode *mtree_current;
72 static fsnode mtree_global;
73 static fsinode mtree_global_inode;
74 static u_int errors, warnings;
75 
76 static void mtree_error(const char *, ...) __printflike(1, 2);
77 static void mtree_warning(const char *, ...) __printflike(1, 2);
78 
79 static int
80 mtree_file_push(const char *name, FILE *fp)
81 {
82 	struct mtree_fileinfo *fi;
83 
84 	fi = emalloc(sizeof(*fi));
85 	if (strcmp(name, "-") == 0)
86 		fi->name = estrdup("(stdin)");
87 	else
88 		fi->name = estrdup(name);
89 	if (fi->name == NULL) {
90 		free(fi);
91 		return (ENOMEM);
92 	}
93 
94 	fi->fp = fp;
95 	fi->line = 0;
96 
97 	SLIST_INSERT_HEAD(&mtree_fileinfo, fi, next);
98 	return (0);
99 }
100 
101 static void
102 mtree_print(const char *msgtype, const char *fmt, va_list ap)
103 {
104 	struct mtree_fileinfo *fi;
105 
106 	if (msgtype != NULL) {
107 		fi = SLIST_FIRST(&mtree_fileinfo);
108 		if (fi != NULL)
109 			fprintf(stderr, "%s:%u: ", fi->name, fi->line);
110 		fprintf(stderr, "%s: ", msgtype);
111 	}
112 	vfprintf(stderr, fmt, ap);
113 }
114 
115 static void
116 mtree_error(const char *fmt, ...)
117 {
118 	va_list ap;
119 
120 	va_start(ap, fmt);
121 	mtree_print("error", fmt, ap);
122 	va_end(ap);
123 
124 	errors++;
125 	fputc('\n', stderr);
126 }
127 
128 static void
129 mtree_warning(const char *fmt, ...)
130 {
131 	va_list ap;
132 
133 	va_start(ap, fmt);
134 	mtree_print("warning", fmt, ap);
135 	va_end(ap);
136 
137 	warnings++;
138 	fputc('\n', stderr);
139 }
140 
141 #ifndef MAKEFS_MAX_TREE_DEPTH
142 # define MAKEFS_MAX_TREE_DEPTH (MAXPATHLEN/2)
143 #endif
144 
145 /* construct path to node->name */
146 static char *
147 mtree_file_path(fsnode *node)
148 {
149 	fsnode *pnode;
150 	struct sbuf *sb;
151 	char *res, *rp[MAKEFS_MAX_TREE_DEPTH];
152 	int depth;
153 
154 	depth = 0;
155 	rp[depth] = node->name;
156 	for (pnode = node->parent; pnode && depth < MAKEFS_MAX_TREE_DEPTH - 1;
157 	     pnode = pnode->parent) {
158 		if (strcmp(pnode->name, ".") == 0)
159 			break;
160 		rp[++depth] = pnode->name;
161 	}
162 
163 	sb = sbuf_new_auto();
164 	if (sb == NULL) {
165 		errno = ENOMEM;
166 		return (NULL);
167 	}
168 	while (depth > 0) {
169 		sbuf_cat(sb, rp[depth--]);
170 		sbuf_putc(sb, '/');
171 	}
172 	sbuf_cat(sb, rp[depth]);
173 	sbuf_finish(sb);
174 	res = estrdup(sbuf_data(sb));
175 	sbuf_delete(sb);
176 	if (res == NULL)
177 		errno = ENOMEM;
178 	return res;
179 
180 }
181 
182 /* mtree_resolve() sets errno to indicate why NULL was returned. */
183 static char *
184 mtree_resolve(const char *spec, int *istemp)
185 {
186 	struct sbuf *sb;
187 	char *res, *var = NULL;
188 	const char *base, *p, *v;
189 	size_t len;
190 	int c, error, quoted, subst;
191 
192 	len = strlen(spec);
193 	if (len == 0) {
194 		errno = EINVAL;
195 		return (NULL);
196 	}
197 
198 	c = (len > 1) ? (spec[0] == spec[len - 1]) ? spec[0] : 0 : 0;
199 	*istemp = (c == '`') ? 1 : 0;
200 	subst = (c == '`' || c == '"') ? 1 : 0;
201 	quoted = (subst || c == '\'') ? 1 : 0;
202 
203 	if (!subst) {
204 		res = estrdup(spec + quoted);
205 		if (quoted)
206 			res[len - 2] = '\0';
207 		return (res);
208 	}
209 
210 	sb = sbuf_new_auto();
211 	if (sb == NULL) {
212 		errno = ENOMEM;
213 		return (NULL);
214 	}
215 
216 	base = spec + 1;
217 	len -= 2;
218 	error = 0;
219 	while (len > 0) {
220 		p = strchr(base, '$');
221 		if (p == NULL) {
222 			sbuf_bcat(sb, base, len);
223 			base += len;
224 			len = 0;
225 			continue;
226 		}
227 		/* The following is safe. spec always starts with a quote. */
228 		if (p[-1] == '\\')
229 			p--;
230 		if (base != p) {
231 			sbuf_bcat(sb, base, p - base);
232 			len -= p - base;
233 			base = p;
234 		}
235 		if (*p == '\\') {
236 			sbuf_putc(sb, '$');
237 			base += 2;
238 			len -= 2;
239 			continue;
240 		}
241 		/* Skip the '$'. */
242 		base++;
243 		len--;
244 		/* Handle ${X} vs $X. */
245 		v = base;
246 		if (*base == '{') {
247 			p = strchr(v, '}');
248 			if (p == NULL)
249 				p = v;
250 		} else
251 			p = v;
252 		len -= (p + 1) - base;
253 		base = p + 1;
254 
255 		if (v == p) {
256 			sbuf_putc(sb, *v);
257 			continue;
258 		}
259 
260 		error = ENOMEM;
261 		var = ecalloc(p - v, 1);
262 		memcpy(var, v + 1, p - v - 1);
263 		if (strcmp(var, ".CURDIR") == 0) {
264 			res = getcwd(NULL, 0);
265 			if (res == NULL)
266 				break;
267 		} else if (strcmp(var, ".PROG") == 0) {
268 			res = estrdup(getprogname());
269 		} else {
270 			v = getenv(var);
271 			if (v != NULL) {
272 				res = estrdup(v);
273 			} else
274 				res = NULL;
275 		}
276 		error = 0;
277 
278 		if (res != NULL) {
279 			sbuf_cat(sb, res);
280 			free(res);
281 		}
282 		free(var);
283 		var = NULL;
284 	}
285 
286 	free(var);
287 	sbuf_finish(sb);
288 	res = (error == 0) ? strdup(sbuf_data(sb)) : NULL;
289 	sbuf_delete(sb);
290 	if (res == NULL)
291 		errno = ENOMEM;
292 	return (res);
293 }
294 
295 static int
296 skip_over(FILE *fp, const char *cs)
297 {
298 	int c;
299 
300 	c = getc(fp);
301 	while (c != EOF && strchr(cs, c) != NULL)
302 		c = getc(fp);
303 	if (c != EOF) {
304 		ungetc(c, fp);
305 		return (0);
306 	}
307 	return (ferror(fp) ? errno : -1);
308 }
309 
310 static int
311 skip_to(FILE *fp, const char *cs)
312 {
313 	int c;
314 
315 	c = getc(fp);
316 	while (c != EOF && strchr(cs, c) == NULL)
317 		c = getc(fp);
318 	if (c != EOF) {
319 		ungetc(c, fp);
320 		return (0);
321 	}
322 	return (ferror(fp) ? errno : -1);
323 }
324 
325 static int
326 read_word(FILE *fp, char *buf, size_t bufsz)
327 {
328 	struct mtree_fileinfo *fi;
329 	size_t idx, qidx;
330 	int c, done, error, esc, qlvl;
331 
332 	if (bufsz == 0)
333 		return (EINVAL);
334 
335 	done = 0;
336 	esc = 0;
337 	idx = 0;
338 	qidx = -1;
339 	qlvl = 0;
340 	do {
341 		c = getc(fp);
342 		switch (c) {
343 		case EOF:
344 			buf[idx] = '\0';
345 			error = ferror(fp) ? errno : -1;
346 			if (error == -1)
347 				mtree_error("unexpected end of file");
348 			return (error);
349 		case '#':		/* comment -- skip to end of line. */
350 			if (!esc) {
351 				error = skip_to(fp, "\n");
352 				if (!error)
353 					continue;
354 			}
355 			break;
356 		case '\\':
357 			esc++;
358 			if (esc == 1)
359 				continue;
360 			break;
361 		case '`':
362 		case '\'':
363 		case '"':
364 			if (esc)
365 				break;
366 			if (qlvl == 0) {
367 				qlvl++;
368 				qidx = idx;
369 			} else if (c == buf[qidx]) {
370 				qlvl--;
371 				if (qlvl > 0) {
372 					do {
373 						qidx--;
374 					} while (buf[qidx] != '`' &&
375 					    buf[qidx] != '\'' &&
376 					    buf[qidx] != '"');
377 				} else
378 					qidx = -1;
379 			} else {
380 				qlvl++;
381 				qidx = idx;
382 			}
383 			break;
384 		case ' ':
385 		case '\t':
386 		case '\n':
387 			if (!esc && qlvl == 0) {
388 				ungetc(c, fp);
389 				c = '\0';
390 				done = 1;
391 				break;
392 			}
393 			if (c == '\n') {
394 				/*
395 				 * We going to eat the newline ourselves.
396 				 */
397 				if (qlvl > 0)
398 					mtree_warning("quoted word straddles "
399 					    "onto next line.");
400 				fi = SLIST_FIRST(&mtree_fileinfo);
401 				fi->line++;
402 			}
403 			break;
404 		case 'a':
405 			if (esc)
406 				c = '\a';
407 			break;
408 		case 'b':
409 			if (esc)
410 				c = '\b';
411 			break;
412 		case 'f':
413 			if (esc)
414 				c = '\f';
415 			break;
416 		case 'n':
417 			if (esc)
418 				c = '\n';
419 			break;
420 		case 'r':
421 			if (esc)
422 				c = '\r';
423 			break;
424 		case 't':
425 			if (esc)
426 				c = '\t';
427 			break;
428 		case 'v':
429 			if (esc)
430 				c = '\v';
431 			break;
432 		}
433 		buf[idx++] = c;
434 		esc = 0;
435 	} while (idx < bufsz && !done);
436 
437 	if (idx >= bufsz) {
438 		mtree_error("word too long to fit buffer (max %zu characters)",
439 		    bufsz);
440 		skip_to(fp, " \t\n");
441 	}
442 	return (0);
443 }
444 
445 static fsnode *
446 create_node(const char *name, u_int type, fsnode *parent, fsnode *global)
447 {
448 	fsnode *n;
449 
450 	n = ecalloc(1, sizeof(*n));
451 	n->name = estrdup(name);
452 	n->type = (type == 0) ? global->type : type;
453 	n->parent = parent;
454 
455 	n->inode = ecalloc(1, sizeof(*n->inode));
456 
457 	/* Assign global options/defaults. */
458 	memcpy(n->inode, global->inode, sizeof(*n->inode));
459 	n->inode->st.st_mode = (n->inode->st.st_mode & ~S_IFMT) | n->type;
460 
461 	if (n->type == S_IFLNK)
462 		n->symlink = global->symlink;
463 	else if (n->type == S_IFREG)
464 		n->contents = global->contents;
465 
466 	return (n);
467 }
468 
469 static void
470 destroy_node(fsnode *n)
471 {
472 
473 	assert(n != NULL);
474 	assert(n->name != NULL);
475 	assert(n->inode != NULL);
476 
477 	free(n->inode);
478 	free(n->name);
479 	free(n);
480 }
481 
482 static int
483 read_number(const char *tok, u_int base, intmax_t *res, intmax_t min,
484     intmax_t max)
485 {
486 	char *end;
487 	intmax_t val;
488 
489 	val = strtoimax(tok, &end, base);
490 	if (end == tok || end[0] != '\0')
491 		return (EINVAL);
492 	if (val < min || val > max)
493 		return (EDOM);
494 	*res = val;
495 	return (0);
496 }
497 
498 static int
499 read_mtree_keywords(FILE *fp, fsnode *node)
500 {
501 	char keyword[PATH_MAX];
502 	char *name, *p, *value;
503 	gid_t gid;
504 	uid_t uid;
505 	struct stat *st, sb;
506 	intmax_t num;
507 	u_long flset, flclr;
508 	int error, istemp;
509 	uint32_t type;
510 
511 	st = &node->inode->st;
512 	do {
513 		error = skip_over(fp, " \t");
514 		if (error)
515 			break;
516 
517 		error = read_word(fp, keyword, sizeof(keyword));
518 		if (error)
519 			break;
520 
521 		if (keyword[0] == '\0')
522 			break;
523 
524 		value = strchr(keyword, '=');
525 		if (value != NULL)
526 			*value++ = '\0';
527 
528 		/*
529 		 * We use EINVAL, ENOATTR, ENOSYS and ENXIO to signal
530 		 * certain conditions:
531 		 *   EINVAL -	Value provided for a keyword that does
532 		 *		not take a value. The value is ignored.
533 		 *   ENOATTR -	Value missing for a keyword that needs
534 		 *		a value. The keyword is ignored.
535 		 *   ENOSYS -	Unsupported keyword encountered. The
536 		 *		keyword is ignored.
537 		 *   ENXIO -	Value provided for a keyword that does
538 		 *		not take a value. The value is ignored.
539 		 */
540 		switch (keyword[0]) {
541 		case 'c':
542 			if (strcmp(keyword, "contents") == 0) {
543 				if (value == NULL) {
544 					error = ENOATTR;
545 					break;
546 				}
547 				node->contents = estrdup(value);
548 			} else
549 				error = ENOSYS;
550 			break;
551 		case 'f':
552 			if (strcmp(keyword, "flags") == 0) {
553 				if (value == NULL) {
554 					error = ENOATTR;
555 					break;
556 				}
557 				flset = flclr = 0;
558 				if (!strtofflags(&value, &flset, &flclr)) {
559 					st->st_flags &= ~flclr;
560 					st->st_flags |= flset;
561 				} else
562 					error = errno;
563 			} else
564 				error = ENOSYS;
565 			break;
566 		case 'g':
567 			if (strcmp(keyword, "gid") == 0) {
568 				if (value == NULL) {
569 					error = ENOATTR;
570 					break;
571 				}
572 				error = read_number(value, 10, &num,
573 				    0, UINT_MAX);
574 				if (!error)
575 					st->st_gid = num;
576 			} else if (strcmp(keyword, "gname") == 0) {
577 				if (value == NULL) {
578 					error = ENOATTR;
579 					break;
580 				}
581 				if (gid_from_group(value, &gid) == 0)
582 					st->st_gid = gid;
583 				else
584 					error = EINVAL;
585 			} else
586 				error = ENOSYS;
587 			break;
588 		case 'l':
589 			if (strcmp(keyword, "link") == 0) {
590 				if (value == NULL) {
591 					error = ENOATTR;
592 					break;
593 				}
594 				node->symlink = estrdup(value);
595 			} else
596 				error = ENOSYS;
597 			break;
598 		case 'm':
599 			if (strcmp(keyword, "mode") == 0) {
600 				if (value == NULL) {
601 					error = ENOATTR;
602 					break;
603 				}
604 				if (value[0] >= '0' && value[0] <= '9') {
605 					error = read_number(value, 8, &num,
606 					    0, 07777);
607 					if (!error) {
608 						st->st_mode &= S_IFMT;
609 						st->st_mode |= num;
610 					}
611 				} else {
612 					/* Symbolic mode not supported. */
613 					error = EINVAL;
614 					break;
615 				}
616 			} else
617 				error = ENOSYS;
618 			break;
619 		case 'o':
620 			if (strcmp(keyword, "optional") == 0) {
621 				if (value != NULL)
622 					error = ENXIO;
623 				node->flags |= FSNODE_F_OPTIONAL;
624 			} else
625 				error = ENOSYS;
626 			break;
627 		case 's':
628 			if (strcmp(keyword, "size") == 0) {
629 				if (value == NULL) {
630 					error = ENOATTR;
631 					break;
632 				}
633 				error = read_number(value, 10, &num,
634 				    0, INTMAX_MAX);
635 				if (!error)
636 					st->st_size = num;
637 			} else
638 				error = ENOSYS;
639 			break;
640 		case 't':
641 			if (strcmp(keyword, "time") == 0) {
642 				if (value == NULL) {
643 					error = ENOATTR;
644 					break;
645 				}
646 				p = strchr(value, '.');
647 				if (p != NULL)
648 					*p++ = '\0';
649 				error = read_number(value, 10, &num, 0,
650 				    INTMAX_MAX);
651 				if (error)
652 					break;
653 				st->st_atime = num;
654 				st->st_ctime = num;
655 				st->st_mtime = num;
656 				if (p == NULL)
657 					break;
658 				error = read_number(p, 10, &num, 0,
659 				    INTMAX_MAX);
660 				if (error)
661 					break;
662 				if (num != 0)
663 					error = EINVAL;
664 			} else if (strcmp(keyword, "type") == 0) {
665 				if (value == NULL) {
666 					error = ENOATTR;
667 					break;
668 				}
669 				if (strcmp(value, "dir") == 0)
670 					node->type = S_IFDIR;
671 				else if (strcmp(value, "file") == 0)
672 					node->type = S_IFREG;
673 				else if (strcmp(value, "link") == 0)
674 					node->type = S_IFLNK;
675 				else
676 					error = EINVAL;
677 			} else
678 				error = ENOSYS;
679 			break;
680 		case 'u':
681 			if (strcmp(keyword, "uid") == 0) {
682 				if (value == NULL) {
683 					error = ENOATTR;
684 					break;
685 				}
686 				error = read_number(value, 10, &num,
687 				    0, UINT_MAX);
688 				if (!error)
689 					st->st_uid = num;
690 			} else if (strcmp(keyword, "uname") == 0) {
691 				if (value == NULL) {
692 					error = ENOATTR;
693 					break;
694 				}
695 				if (uid_from_user(value, &uid) == 0)
696 					st->st_uid = uid;
697 				else
698 					error = EINVAL;
699 			} else
700 				error = ENOSYS;
701 			break;
702 		default:
703 			error = ENOSYS;
704 			break;
705 		}
706 
707 		switch (error) {
708 		case EINVAL:
709 			mtree_error("%s: invalid value '%s'", keyword, value);
710 			break;
711 		case ENOATTR:
712 			mtree_error("%s: keyword needs a value", keyword);
713 			break;
714 		case ENOSYS:
715 			mtree_warning("%s: unsupported keyword", keyword);
716 			break;
717 		case ENXIO:
718 			mtree_error("%s: keyword does not take a value",
719 			    keyword);
720 			break;
721 		}
722 	} while (1);
723 
724 	if (error)
725 		return (error);
726 
727 	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
728 
729 	/* Nothing more to do for the global defaults. */
730 	if (node->name == NULL)
731 		return (0);
732 
733 	/*
734 	 * Be intelligent about the file type.
735 	 */
736 	if (node->contents != NULL) {
737 		if (node->symlink != NULL) {
738 			mtree_error("%s: both link and contents keywords "
739 			    "defined", node->name);
740 			return (0);
741 		}
742 		type = S_IFREG;
743 	} else if (node->type != 0) {
744 		type = node->type;
745 		if (type == S_IFREG) {
746 			/* the named path is the default contents */
747 			node->contents = mtree_file_path(node);
748 		}
749 	} else
750 		type = (node->symlink != NULL) ? S_IFLNK : S_IFDIR;
751 
752 	if (node->type == 0)
753 		node->type = type;
754 
755 	if (node->type != type) {
756 		mtree_error("%s: file type and defined keywords to not match",
757 		    node->name);
758 		return (0);
759 	}
760 
761 	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
762 
763 	if (node->contents == NULL)
764 		return (0);
765 
766 	name = mtree_resolve(node->contents, &istemp);
767 	if (name == NULL)
768 		return (errno);
769 
770 	if (stat(name, &sb) != 0) {
771 		mtree_error("%s: contents file '%s' not found", node->name,
772 		    name);
773 		free(name);
774 		return (0);
775 	}
776 
777 	/*
778          * Check for hardlinks. If the contents key is used, then the check
779          * will only trigger if the contents file is a link even if it is used
780          * by more than one file
781 	 */
782 	if (sb.st_nlink > 1) {
783 		fsinode *curino;
784 
785 		st->st_ino = sb.st_ino;
786 		st->st_dev = sb.st_dev;
787 		curino = link_check(node->inode);
788 		if (curino != NULL) {
789 			free(node->inode);
790 			node->inode = curino;
791 			node->inode->nlink++;
792 		}
793 	}
794 
795 	free(node->contents);
796 	node->contents = name;
797 	st->st_size = sb.st_size;
798 	return (0);
799 }
800 
801 static int
802 read_mtree_command(FILE *fp)
803 {
804 	char cmd[10];
805 	int error;
806 
807 	error = read_word(fp, cmd, sizeof(cmd));
808 	if (error)
809 		goto out;
810 
811 	error = read_mtree_keywords(fp, &mtree_global);
812 
813  out:
814 	skip_to(fp, "\n");
815 	(void)getc(fp);
816 	return (error);
817 }
818 
819 static int
820 read_mtree_spec1(FILE *fp, bool def, const char *name)
821 {
822 	fsnode *last, *node, *parent;
823 	u_int type;
824 	int error;
825 
826 	assert(name[0] != '\0');
827 
828 	/*
829 	 * Treat '..' specially, because it only changes our current
830 	 * directory. We don't create a node for it. We simply ignore
831 	 * any keywords that may appear on the line as well.
832 	 * Going up a directory is a little non-obvious. A directory
833 	 * node has a corresponding '.' child. The parent of '.' is
834 	 * not the '.' node of the parent directory, but the directory
835 	 * node within the parent to which the child relates. However,
836 	 * going up a directory means we need to find the '.' node to
837 	 * which the directoy node is linked.  This we can do via the
838 	 * first * pointer, because '.' is always the first entry in a
839 	 * directory.
840 	 */
841 	if (IS_DOTDOT(name)) {
842 		/* This deals with NULL pointers as well. */
843 		if (mtree_current == mtree_root) {
844 			mtree_warning("ignoring .. in root directory");
845 			return (0);
846 		}
847 
848 		node = mtree_current;
849 
850 		assert(node != NULL);
851 		assert(IS_DOT(node->name));
852 		assert(node->first == node);
853 
854 		/* Get the corresponding directory node in the parent. */
855 		node = mtree_current->parent;
856 
857 		assert(node != NULL);
858 		assert(!IS_DOT(node->name));
859 
860 		node = node->first;
861 
862 		assert(node != NULL);
863 		assert(IS_DOT(node->name));
864 		assert(node->first == node);
865 
866 		mtree_current = node;
867 		return (0);
868 	}
869 
870 	/*
871 	 * If we don't have a current directory and the first specification
872 	 * (either implicit or defined) is not '.', then we need to create
873 	 * a '.' node first (using a recursive call).
874 	 */
875 	if (!IS_DOT(name) && mtree_current == NULL) {
876 		error = read_mtree_spec1(fp, false, ".");
877 		if (error)
878 			return (error);
879 	}
880 
881 	/*
882 	 * Lookup the name in the current directory (if we have a current
883 	 * directory) to make sure we do not create multiple nodes for the
884 	 * same component. For non-definitions, if we find a node with the
885 	 * same name, simply change the current directory. For definitions
886 	 * more happens.
887 	 */
888 	last = NULL;
889 	node = mtree_current;
890 	while (node != NULL) {
891 		assert(node->first == mtree_current);
892 
893 		if (strcmp(name, node->name) == 0) {
894 			if (def == true) {
895 				if (!dupsok)
896 					mtree_error(
897 					    "duplicate definition of %s",
898 					    name);
899 				else
900 					mtree_warning(
901 					    "duplicate definition of %s",
902 					    name);
903 				return (0);
904 			}
905 
906 			if (node->type != S_IFDIR) {
907 				mtree_error("%s is not a directory", name);
908 				return (0);
909 			}
910 
911 			assert(!IS_DOT(name));
912 
913 			node = node->child;
914 
915 			assert(node != NULL);
916 			assert(IS_DOT(node->name));
917 
918 			mtree_current = node;
919 			return (0);
920 		}
921 
922 		last = node;
923 		node = last->next;
924 	}
925 
926 	parent = (mtree_current != NULL) ? mtree_current->parent : NULL;
927 	type = (def == false || IS_DOT(name)) ? S_IFDIR : 0;
928 	node = create_node(name, type, parent, &mtree_global);
929 	if (node == NULL)
930 		return (ENOMEM);
931 
932 	if (def == true) {
933 		error = read_mtree_keywords(fp, node);
934 		if (error) {
935 			destroy_node(node);
936 			return (error);
937 		}
938 	}
939 
940 	node->first = (mtree_current != NULL) ? mtree_current : node;
941 
942 	if (last != NULL)
943 		last->next = node;
944 
945 	if (node->type != S_IFDIR)
946 		return (0);
947 
948 	if (!IS_DOT(node->name)) {
949 		parent = node;
950 		node = create_node(".", S_IFDIR, parent, parent);
951 		if (node == NULL) {
952 			last->next = NULL;
953 			destroy_node(parent);
954 			return (ENOMEM);
955 		}
956 		parent->child = node;
957 		node->first = node;
958 	}
959 
960 	assert(node != NULL);
961 	assert(IS_DOT(node->name));
962 	assert(node->first == node);
963 
964 	mtree_current = node;
965 	if (mtree_root == NULL)
966 		mtree_root = node;
967 
968 	return (0);
969 }
970 
971 static int
972 read_mtree_spec(FILE *fp)
973 {
974 	char pathspec[PATH_MAX];
975 	char *cp;
976 	int error;
977 
978 	error = read_word(fp, pathspec, sizeof(pathspec));
979 	if (error)
980 		goto out;
981 
982 	cp = strchr(pathspec, '/');
983 	if (cp != NULL) {
984 		/* Absolute pathname */
985 		mtree_current = mtree_root;
986 
987 		do {
988 			*cp++ = '\0';
989 
990 			/* Disallow '..' as a component. */
991 			if (IS_DOTDOT(pathspec)) {
992 				mtree_error("absolute path cannot contain "
993 				    ".. component");
994 				goto out;
995 			}
996 
997 			/* Ignore multiple adjacent slashes and '.'. */
998 			if (pathspec[0] != '\0' && !IS_DOT(pathspec))
999 				error = read_mtree_spec1(fp, false, pathspec);
1000 			memmove(pathspec, cp, strlen(cp) + 1);
1001 			cp = strchr(pathspec, '/');
1002 		} while (!error && cp != NULL);
1003 
1004 		/* Disallow '.' and '..' as the last component. */
1005 		if (!error && (IS_DOT(pathspec) || IS_DOTDOT(pathspec))) {
1006 			mtree_error("absolute path cannot contain . or .. "
1007 			    "components");
1008 			goto out;
1009 		}
1010 	}
1011 
1012 	/* Ignore absolute specfications that end with a slash. */
1013 	if (!error && pathspec[0] != '\0')
1014 		error = read_mtree_spec1(fp, true, pathspec);
1015 
1016  out:
1017 	skip_to(fp, "\n");
1018 	(void)getc(fp);
1019 	return (error);
1020 }
1021 
1022 fsnode *
1023 read_mtree(const char *fname, fsnode *node)
1024 {
1025 	struct mtree_fileinfo *fi;
1026 	FILE *fp;
1027 	int c, error;
1028 
1029 	/* We do not yet support nesting... */
1030 	assert(node == NULL);
1031 
1032 	if (strcmp(fname, "-") == 0)
1033 		fp = stdin;
1034 	else {
1035 		fp = fopen(fname, "r");
1036 		if (fp == NULL)
1037 			err(1, "Can't open `%s'", fname);
1038 	}
1039 
1040 	error = mtree_file_push(fname, fp);
1041 	if (error)
1042 		goto out;
1043 
1044 	memset(&mtree_global, 0, sizeof(mtree_global));
1045 	memset(&mtree_global_inode, 0, sizeof(mtree_global_inode));
1046 	mtree_global.inode = &mtree_global_inode;
1047 	mtree_global_inode.nlink = 1;
1048 	mtree_global_inode.st.st_nlink = 1;
1049 	mtree_global_inode.st.st_atime = mtree_global_inode.st.st_ctime =
1050 	    mtree_global_inode.st.st_mtime = time(NULL);
1051 	errors = warnings = 0;
1052 
1053 	setgroupent(1);
1054 	setpassent(1);
1055 
1056 	mtree_root = node;
1057 	mtree_current = node;
1058 	do {
1059 		/* Start of a new line... */
1060 		fi = SLIST_FIRST(&mtree_fileinfo);
1061 		fi->line++;
1062 
1063 		error = skip_over(fp, " \t");
1064 		if (error)
1065 			break;
1066 
1067 		c = getc(fp);
1068 		if (c == EOF) {
1069 			error = ferror(fp) ? errno : -1;
1070 			break;
1071 		}
1072 
1073 		switch (c) {
1074 		case '\n':		/* empty line */
1075 			error = 0;
1076 			break;
1077 		case '#':		/* comment -- skip to end of line. */
1078 			error = skip_to(fp, "\n");
1079 			if (!error)
1080 				(void)getc(fp);
1081 			break;
1082 		case '/':		/* special commands */
1083 			error = read_mtree_command(fp);
1084 			break;
1085 		default:		/* specification */
1086 			ungetc(c, fp);
1087 			error = read_mtree_spec(fp);
1088 			break;
1089 		}
1090 	} while (!error);
1091 
1092 	endpwent();
1093 	endgrent();
1094 
1095 	if (error <= 0 && (errors || warnings)) {
1096 		warnx("%u error(s) and %u warning(s) in mtree manifest",
1097 		    errors, warnings);
1098 		if (errors)
1099 			exit(1);
1100 	}
1101 
1102  out:
1103 	if (error > 0)
1104 		errc(1, error, "Error reading mtree file");
1105 
1106 	if (fp != stdin)
1107 		fclose(fp);
1108 
1109 	if (mtree_root != NULL)
1110 		return (mtree_root);
1111 
1112 	/* Handle empty specifications. */
1113 	node = create_node(".", S_IFDIR, NULL, &mtree_global);
1114 	node->first = node;
1115 	return (node);
1116 }
1117