xref: /freebsd/usr.sbin/makefs/mtree.c (revision e9ac41698b2f322d55ccf9da50a3596edb2c1800)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2011 Marcel Moolenaar
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19  * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 #if HAVE_NBTOOL_CONFIG_H
29 #include "nbtool_config.h"
30 #endif
31 
32 #include <sys/param.h>
33 #include <sys/queue.h>
34 #include <sys/sbuf.h>
35 #include <sys/stat.h>
36 #include <sys/types.h>
37 #include <assert.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <grp.h>
41 #include <inttypes.h>
42 #include <pwd.h>
43 #include <stdarg.h>
44 #include <stdbool.h>
45 #include <stddef.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <strings.h>
50 #include <time.h>
51 #include <unistd.h>
52 #include <util.h>
53 #include <vis.h>
54 
55 #include "makefs.h"
56 
57 #ifndef ENOATTR
58 #define	ENOATTR	ENODATA
59 #endif
60 
61 #define	IS_DOT(nm)	((nm)[0] == '.' && (nm)[1] == '\0')
62 #define	IS_DOTDOT(nm)	((nm)[0] == '.' && (nm)[1] == '.' && (nm)[2] == '\0')
63 
64 struct mtree_fileinfo {
65 	SLIST_ENTRY(mtree_fileinfo) next;
66 	FILE *fp;
67 	const char *name;
68 	u_int line;
69 };
70 
71 /* Global state used while parsing. */
72 static SLIST_HEAD(, mtree_fileinfo) mtree_fileinfo =
73     SLIST_HEAD_INITIALIZER(mtree_fileinfo);
74 static fsnode *mtree_root;
75 static fsnode *mtree_current;
76 static fsnode mtree_global;
77 static fsinode mtree_global_inode;
78 static u_int errors, warnings;
79 
80 static void mtree_error(const char *, ...) __printflike(1, 2);
81 static void mtree_warning(const char *, ...) __printflike(1, 2);
82 
83 static int
84 mtree_file_push(const char *name, FILE *fp)
85 {
86 	struct mtree_fileinfo *fi;
87 
88 	fi = emalloc(sizeof(*fi));
89 	if (strcmp(name, "-") == 0)
90 		fi->name = estrdup("(stdin)");
91 	else
92 		fi->name = estrdup(name);
93 	if (fi->name == NULL) {
94 		free(fi);
95 		return (ENOMEM);
96 	}
97 
98 	fi->fp = fp;
99 	fi->line = 0;
100 
101 	SLIST_INSERT_HEAD(&mtree_fileinfo, fi, next);
102 	return (0);
103 }
104 
105 static void
106 mtree_print(const char *msgtype, const char *fmt, va_list ap)
107 {
108 	struct mtree_fileinfo *fi;
109 
110 	if (msgtype != NULL) {
111 		fi = SLIST_FIRST(&mtree_fileinfo);
112 		if (fi != NULL)
113 			fprintf(stderr, "%s:%u: ", fi->name, fi->line);
114 		fprintf(stderr, "%s: ", msgtype);
115 	}
116 	vfprintf(stderr, fmt, ap);
117 }
118 
119 static void
120 mtree_error(const char *fmt, ...)
121 {
122 	va_list ap;
123 
124 	va_start(ap, fmt);
125 	mtree_print("error", fmt, ap);
126 	va_end(ap);
127 
128 	errors++;
129 	fputc('\n', stderr);
130 }
131 
132 static void
133 mtree_warning(const char *fmt, ...)
134 {
135 	va_list ap;
136 
137 	va_start(ap, fmt);
138 	mtree_print("warning", fmt, ap);
139 	va_end(ap);
140 
141 	warnings++;
142 	fputc('\n', stderr);
143 }
144 
145 #ifndef MAKEFS_MAX_TREE_DEPTH
146 # define MAKEFS_MAX_TREE_DEPTH (MAXPATHLEN/2)
147 #endif
148 
149 /* construct path to node->name */
150 static char *
151 mtree_file_path(fsnode *node)
152 {
153 	fsnode *pnode;
154 	struct sbuf *sb;
155 	char *res, *rp[MAKEFS_MAX_TREE_DEPTH];
156 	int depth;
157 
158 	depth = 0;
159 	rp[depth] = node->name;
160 	for (pnode = node->parent; pnode && depth < MAKEFS_MAX_TREE_DEPTH - 1;
161 	     pnode = pnode->parent) {
162 		if (strcmp(pnode->name, ".") == 0)
163 			break;
164 		rp[++depth] = pnode->name;
165 	}
166 
167 	sb = sbuf_new_auto();
168 	if (sb == NULL) {
169 		errno = ENOMEM;
170 		return (NULL);
171 	}
172 	while (depth > 0) {
173 		sbuf_cat(sb, rp[depth--]);
174 		sbuf_putc(sb, '/');
175 	}
176 	sbuf_cat(sb, rp[depth]);
177 	sbuf_finish(sb);
178 	res = estrdup(sbuf_data(sb));
179 	sbuf_delete(sb);
180 	if (res == NULL)
181 		errno = ENOMEM;
182 	return res;
183 
184 }
185 
186 /* mtree_resolve() sets errno to indicate why NULL was returned. */
187 static char *
188 mtree_resolve(const char *spec, int *istemp)
189 {
190 	struct sbuf *sb;
191 	char *res, *var = NULL;
192 	const char *base, *p, *v;
193 	size_t len;
194 	int c, error, quoted, subst;
195 
196 	len = strlen(spec);
197 	if (len == 0) {
198 		errno = EINVAL;
199 		return (NULL);
200 	}
201 
202 	c = (len > 1) ? (spec[0] == spec[len - 1]) ? spec[0] : 0 : 0;
203 	*istemp = (c == '`') ? 1 : 0;
204 	subst = (c == '`' || c == '"') ? 1 : 0;
205 	quoted = (subst || c == '\'') ? 1 : 0;
206 
207 	if (!subst) {
208 		res = estrdup(spec + quoted);
209 		if (quoted)
210 			res[len - 2] = '\0';
211 		return (res);
212 	}
213 
214 	sb = sbuf_new_auto();
215 	if (sb == NULL) {
216 		errno = ENOMEM;
217 		return (NULL);
218 	}
219 
220 	base = spec + 1;
221 	len -= 2;
222 	error = 0;
223 	while (len > 0) {
224 		p = strchr(base, '$');
225 		if (p == NULL) {
226 			sbuf_bcat(sb, base, len);
227 			base += len;
228 			len = 0;
229 			continue;
230 		}
231 		/* The following is safe. spec always starts with a quote. */
232 		if (p[-1] == '\\')
233 			p--;
234 		if (base != p) {
235 			sbuf_bcat(sb, base, p - base);
236 			len -= p - base;
237 			base = p;
238 		}
239 		if (*p == '\\') {
240 			sbuf_putc(sb, '$');
241 			base += 2;
242 			len -= 2;
243 			continue;
244 		}
245 		/* Skip the '$'. */
246 		base++;
247 		len--;
248 		/* Handle ${X} vs $X. */
249 		v = base;
250 		if (*base == '{') {
251 			p = strchr(v, '}');
252 			if (p == NULL)
253 				p = v;
254 		} else
255 			p = v;
256 		len -= (p + 1) - base;
257 		base = p + 1;
258 
259 		if (v == p) {
260 			sbuf_putc(sb, *v);
261 			continue;
262 		}
263 
264 		error = ENOMEM;
265 		var = ecalloc(p - v, 1);
266 		memcpy(var, v + 1, p - v - 1);
267 		if (strcmp(var, ".CURDIR") == 0) {
268 			res = getcwd(NULL, 0);
269 			if (res == NULL)
270 				break;
271 		} else if (strcmp(var, ".PROG") == 0) {
272 			res = estrdup(getprogname());
273 		} else {
274 			v = getenv(var);
275 			if (v != NULL) {
276 				res = estrdup(v);
277 			} else
278 				res = NULL;
279 		}
280 		error = 0;
281 
282 		if (res != NULL) {
283 			sbuf_cat(sb, res);
284 			free(res);
285 		}
286 		free(var);
287 		var = NULL;
288 	}
289 
290 	free(var);
291 	sbuf_finish(sb);
292 	res = (error == 0) ? strdup(sbuf_data(sb)) : NULL;
293 	sbuf_delete(sb);
294 	if (res == NULL)
295 		errno = ENOMEM;
296 	return (res);
297 }
298 
299 static int
300 skip_over(FILE *fp, const char *cs)
301 {
302 	int c;
303 
304 	c = getc(fp);
305 	while (c != EOF && strchr(cs, c) != NULL)
306 		c = getc(fp);
307 	if (c != EOF) {
308 		ungetc(c, fp);
309 		return (0);
310 	}
311 	return (ferror(fp) ? errno : -1);
312 }
313 
314 static int
315 skip_to(FILE *fp, const char *cs)
316 {
317 	int c;
318 
319 	c = getc(fp);
320 	while (c != EOF && strchr(cs, c) == NULL)
321 		c = getc(fp);
322 	if (c != EOF) {
323 		ungetc(c, fp);
324 		return (0);
325 	}
326 	return (ferror(fp) ? errno : -1);
327 }
328 
329 static int
330 read_word(FILE *fp, char *buf, size_t bufsz)
331 {
332 	struct mtree_fileinfo *fi;
333 	size_t idx, qidx;
334 	int c, done, error, esc, qlvl;
335 
336 	if (bufsz == 0)
337 		return (EINVAL);
338 
339 	done = 0;
340 	esc = 0;
341 	idx = 0;
342 	qidx = -1;
343 	qlvl = 0;
344 	do {
345 		c = getc(fp);
346 		switch (c) {
347 		case EOF:
348 			buf[idx] = '\0';
349 			error = ferror(fp) ? errno : -1;
350 			if (error == -1)
351 				mtree_error("unexpected end of file");
352 			return (error);
353 		case '#':		/* comment -- skip to end of line. */
354 			if (!esc) {
355 				error = skip_to(fp, "\n");
356 				if (!error)
357 					continue;
358 			}
359 			break;
360 		case '\\':
361 			esc++;
362 			break;
363 		case '`':
364 		case '\'':
365 		case '"':
366 			if (esc)
367 				break;
368 			if (qlvl == 0) {
369 				qlvl++;
370 				qidx = idx;
371 			} else if (c == buf[qidx]) {
372 				qlvl--;
373 				if (qlvl > 0) {
374 					do {
375 						qidx--;
376 					} while (buf[qidx] != '`' &&
377 					    buf[qidx] != '\'' &&
378 					    buf[qidx] != '"');
379 				} else
380 					qidx = -1;
381 			} else {
382 				qlvl++;
383 				qidx = idx;
384 			}
385 			break;
386 		case ' ':
387 		case '\t':
388 		case '\n':
389 			if (!esc && qlvl == 0) {
390 				ungetc(c, fp);
391 				c = '\0';
392 				done = 1;
393 				break;
394 			}
395 			if (c == '\n') {
396 				/*
397 				 * We going to eat the newline ourselves.
398 				 */
399 				if (qlvl > 0)
400 					mtree_warning("quoted word straddles "
401 					    "onto next line.");
402 				fi = SLIST_FIRST(&mtree_fileinfo);
403 				fi->line++;
404 			}
405 			break;
406 		default:
407 			if (esc)
408 				buf[idx++] = '\\';
409 			break;
410 		}
411 		buf[idx++] = c;
412 		esc = 0;
413 	} while (idx < bufsz && !done);
414 
415 	if (idx >= bufsz) {
416 		mtree_error("word too long to fit buffer (max %zu characters)",
417 		    bufsz);
418 		skip_to(fp, " \t\n");
419 	}
420 	return (0);
421 }
422 
423 static fsnode *
424 create_node(const char *name, u_int type, fsnode *parent, fsnode *global)
425 {
426 	fsnode *n;
427 
428 	n = ecalloc(1, sizeof(*n));
429 	n->name = estrdup(name);
430 	n->type = (type == 0) ? global->type : type;
431 	n->parent = parent;
432 
433 	n->inode = ecalloc(1, sizeof(*n->inode));
434 
435 	/* Assign global options/defaults. */
436 	memcpy(n->inode, global->inode, sizeof(*n->inode));
437 	n->inode->st.st_mode = (n->inode->st.st_mode & ~S_IFMT) | n->type;
438 
439 	if (n->type == S_IFLNK)
440 		n->symlink = global->symlink;
441 	else if (n->type == S_IFREG)
442 		n->contents = global->contents;
443 
444 	return (n);
445 }
446 
447 static void
448 destroy_node(fsnode *n)
449 {
450 
451 	assert(n != NULL);
452 	assert(n->name != NULL);
453 	assert(n->inode != NULL);
454 
455 	free(n->inode);
456 	free(n->name);
457 	free(n);
458 }
459 
460 static int
461 read_number(const char *tok, u_int base, intmax_t *res, intmax_t min,
462     intmax_t max)
463 {
464 	char *end;
465 	intmax_t val;
466 
467 	val = strtoimax(tok, &end, base);
468 	if (end == tok || end[0] != '\0')
469 		return (EINVAL);
470 	if (val < min || val > max)
471 		return (EDOM);
472 	*res = val;
473 	return (0);
474 }
475 
476 static int
477 read_mtree_keywords(FILE *fp, fsnode *node)
478 {
479 	char keyword[PATH_MAX];
480 	char *name, *p, *value;
481 	gid_t gid;
482 	uid_t uid;
483 	struct stat *st, sb;
484 	intmax_t num;
485 	u_long flset, flclr;
486 	int error, istemp;
487 	uint32_t type;
488 
489 	st = &node->inode->st;
490 	do {
491 		error = skip_over(fp, " \t");
492 		if (error)
493 			break;
494 
495 		error = read_word(fp, keyword, sizeof(keyword));
496 		if (error)
497 			break;
498 
499 		if (keyword[0] == '\0')
500 			break;
501 
502 		value = strchr(keyword, '=');
503 		if (value != NULL)
504 			*value++ = '\0';
505 
506 		/*
507 		 * We use EINVAL, ENOATTR, ENOSYS and ENXIO to signal
508 		 * certain conditions:
509 		 *   EINVAL -	Value provided for a keyword that does
510 		 *		not take a value. The value is ignored.
511 		 *   ENOATTR -	Value missing for a keyword that needs
512 		 *		a value. The keyword is ignored.
513 		 *   ENOSYS -	Unsupported keyword encountered. The
514 		 *		keyword is ignored.
515 		 *   ENXIO -	Value provided for a keyword that does
516 		 *		not take a value. The value is ignored.
517 		 */
518 		switch (keyword[0]) {
519 		case 'c':
520 			if (strcmp(keyword, "contents") == 0) {
521 				if (value == NULL) {
522 					error = ENOATTR;
523 					break;
524 				}
525 				node->contents = estrdup(value);
526 			} else
527 				error = ENOSYS;
528 			break;
529 		case 'f':
530 			if (strcmp(keyword, "flags") == 0) {
531 				if (value == NULL) {
532 					error = ENOATTR;
533 					break;
534 				}
535 				flset = flclr = 0;
536 #if HAVE_STRUCT_STAT_ST_FLAGS
537 				if (!strtofflags(&value, &flset, &flclr)) {
538 					st->st_flags &= ~flclr;
539 					st->st_flags |= flset;
540 				} else
541 					error = errno;
542 #endif
543 			} else
544 				error = ENOSYS;
545 			break;
546 		case 'g':
547 			if (strcmp(keyword, "gid") == 0) {
548 				if (value == NULL) {
549 					error = ENOATTR;
550 					break;
551 				}
552 				error = read_number(value, 10, &num,
553 				    0, UINT_MAX);
554 				if (!error)
555 					st->st_gid = num;
556 			} else if (strcmp(keyword, "gname") == 0) {
557 				if (value == NULL) {
558 					error = ENOATTR;
559 					break;
560 				}
561 				if (gid_from_group(value, &gid) == 0)
562 					st->st_gid = gid;
563 				else
564 					error = EINVAL;
565 			} else
566 				error = ENOSYS;
567 			break;
568 		case 'l':
569 			if (strcmp(keyword, "link") == 0) {
570 				if (value == NULL) {
571 					error = ENOATTR;
572 					break;
573 				}
574 				node->symlink = emalloc(strlen(value) + 1);
575 				if (node->symlink == NULL) {
576 					error = errno;
577 					break;
578 				}
579 				if (strunvis(node->symlink, value) < 0) {
580 					error = errno;
581 					break;
582 				}
583 			} else
584 				error = ENOSYS;
585 			break;
586 		case 'm':
587 			if (strcmp(keyword, "mode") == 0) {
588 				if (value == NULL) {
589 					error = ENOATTR;
590 					break;
591 				}
592 				if (value[0] >= '0' && value[0] <= '9') {
593 					error = read_number(value, 8, &num,
594 					    0, 07777);
595 					if (!error) {
596 						st->st_mode &= S_IFMT;
597 						st->st_mode |= num;
598 					}
599 				} else {
600 					/* Symbolic mode not supported. */
601 					error = EINVAL;
602 					break;
603 				}
604 			} else
605 				error = ENOSYS;
606 			break;
607 		case 'o':
608 			if (strcmp(keyword, "optional") == 0) {
609 				if (value != NULL)
610 					error = ENXIO;
611 				node->flags |= FSNODE_F_OPTIONAL;
612 			} else
613 				error = ENOSYS;
614 			break;
615 		case 's':
616 			if (strcmp(keyword, "size") == 0) {
617 				if (value == NULL) {
618 					error = ENOATTR;
619 					break;
620 				}
621 				error = read_number(value, 10, &num,
622 				    0, INTMAX_MAX);
623 				if (!error)
624 					st->st_size = num;
625 			} else
626 				error = ENOSYS;
627 			break;
628 		case 't':
629 			if (strcmp(keyword, "tags") == 0) {
630 				if (value == NULL) {
631 					error = ENOATTR;
632 					break;
633 				}
634 				/* Ignore. */
635 			} else if (strcmp(keyword, "time") == 0) {
636 				if (value == NULL) {
637 					error = ENOATTR;
638 					break;
639 				}
640 				p = strchr(value, '.');
641 				if (p != NULL)
642 					*p++ = '\0';
643 				error = read_number(value, 10, &num, 0,
644 				    INTMAX_MAX);
645 				if (error)
646 					break;
647 				st->st_atime = num;
648 				st->st_ctime = num;
649 				st->st_mtime = num;
650 #if HAVE_STRUCT_STAT_ST_MTIMENSEC
651 				if (p == NULL)
652 					break;
653 				error = read_number(p, 10, &num, 0,
654 				    INTMAX_MAX);
655 				if (error)
656 					break;
657 				st->st_atimensec = num;
658 				st->st_ctimensec = num;
659 				st->st_mtimensec = num;
660 #endif
661 			} else if (strcmp(keyword, "type") == 0) {
662 				if (value == NULL) {
663 					error = ENOATTR;
664 					break;
665 				}
666 				if (strcmp(value, "dir") == 0)
667 					node->type = S_IFDIR;
668 				else if (strcmp(value, "file") == 0)
669 					node->type = S_IFREG;
670 				else if (strcmp(value, "link") == 0)
671 					node->type = S_IFLNK;
672 				else
673 					error = EINVAL;
674 			} else
675 				error = ENOSYS;
676 			break;
677 		case 'u':
678 			if (strcmp(keyword, "uid") == 0) {
679 				if (value == NULL) {
680 					error = ENOATTR;
681 					break;
682 				}
683 				error = read_number(value, 10, &num,
684 				    0, UINT_MAX);
685 				if (!error)
686 					st->st_uid = num;
687 			} else if (strcmp(keyword, "uname") == 0) {
688 				if (value == NULL) {
689 					error = ENOATTR;
690 					break;
691 				}
692 				if (uid_from_user(value, &uid) == 0)
693 					st->st_uid = uid;
694 				else
695 					error = EINVAL;
696 			} else
697 				error = ENOSYS;
698 			break;
699 		default:
700 			error = ENOSYS;
701 			break;
702 		}
703 
704 		switch (error) {
705 		case EINVAL:
706 			mtree_error("%s: invalid value '%s'", keyword, value);
707 			break;
708 		case ENOATTR:
709 			mtree_error("%s: keyword needs a value", keyword);
710 			break;
711 		case ENOSYS:
712 			mtree_warning("%s: unsupported keyword", keyword);
713 			break;
714 		case ENXIO:
715 			mtree_error("%s: keyword does not take a value",
716 			    keyword);
717 			break;
718 		}
719 	} while (1);
720 
721 	if (error)
722 		return (error);
723 
724 	st->st_mode = (st->st_mode & ~S_IFMT) | node->type;
725 
726 	/* Nothing more to do for the global defaults. */
727 	if (node->name == NULL)
728 		return (0);
729 
730 	/*
731 	 * Be intelligent about the file type.
732 	 */
733 	if (node->contents != NULL) {
734 		if (node->symlink != NULL) {
735 			mtree_error("%s: both link and contents keywords "
736 			    "defined", node->name);
737 			return (0);
738 		}
739 		type = S_IFREG;
740 	} else if (node->type != 0) {
741 		type = node->type;
742 		if (type == S_IFLNK && node->symlink == NULL) {
743 			mtree_error("%s: link type requires link keyword", node->name);
744 			return (0);
745 		} else 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 			/* Reset st since node->inode has been updated. */
793 			st = &node->inode->st;
794 		}
795 	}
796 
797 	free(node->contents);
798 	node->contents = name;
799 	st->st_size = sb.st_size;
800 	return (0);
801 }
802 
803 static int
804 read_mtree_command(FILE *fp)
805 {
806 	char cmd[10];
807 	int error;
808 
809 	error = read_word(fp, cmd, sizeof(cmd));
810 	if (error)
811 		goto out;
812 
813 	error = read_mtree_keywords(fp, &mtree_global);
814 
815  out:
816 	skip_to(fp, "\n");
817 	(void)getc(fp);
818 	return (error);
819 }
820 
821 static int
822 read_mtree_spec1(FILE *fp, bool def, const char *name)
823 {
824 	fsnode *last, *node, *parent;
825 	u_int type;
826 	int error;
827 
828 	assert(name[0] != '\0');
829 
830 	/*
831 	 * Treat '..' specially, because it only changes our current
832 	 * directory. We don't create a node for it. We simply ignore
833 	 * any keywords that may appear on the line as well.
834 	 * Going up a directory is a little non-obvious. A directory
835 	 * node has a corresponding '.' child. The parent of '.' is
836 	 * not the '.' node of the parent directory, but the directory
837 	 * node within the parent to which the child relates. However,
838 	 * going up a directory means we need to find the '.' node to
839 	 * which the directory node is linked.  This we can do via the
840 	 * first * pointer, because '.' is always the first entry in a
841 	 * directory.
842 	 */
843 	if (IS_DOTDOT(name)) {
844 		/* This deals with NULL pointers as well. */
845 		if (mtree_current == mtree_root) {
846 			mtree_warning("ignoring .. in root directory");
847 			return (0);
848 		}
849 
850 		node = mtree_current;
851 
852 		assert(node != NULL);
853 		assert(IS_DOT(node->name));
854 		assert(node->first == node);
855 
856 		/* Get the corresponding directory node in the parent. */
857 		node = mtree_current->parent;
858 
859 		assert(node != NULL);
860 		assert(!IS_DOT(node->name));
861 
862 		node = node->first;
863 
864 		assert(node != NULL);
865 		assert(IS_DOT(node->name));
866 		assert(node->first == node);
867 
868 		mtree_current = node;
869 		return (0);
870 	}
871 
872 	/*
873 	 * If we don't have a current directory and the first specification
874 	 * (either implicit or defined) is not '.', then we need to create
875 	 * a '.' node first (using a recursive call).
876 	 */
877 	if (!IS_DOT(name) && mtree_current == NULL) {
878 		error = read_mtree_spec1(fp, false, ".");
879 		if (error)
880 			return (error);
881 	}
882 
883 	/*
884 	 * Lookup the name in the current directory (if we have a current
885 	 * directory) to make sure we do not create multiple nodes for the
886 	 * same component. For non-definitions, if we find a node with the
887 	 * same name, simply change the current directory. For definitions
888 	 * more happens.
889 	 */
890 	last = NULL;
891 	node = mtree_current;
892 	while (node != NULL) {
893 		assert(node->first == mtree_current);
894 
895 		if (strcmp(name, node->name) == 0) {
896 			if (def == true) {
897 				if (dupsok == 0)
898 					mtree_error(
899 					    "duplicate definition of %s",
900 					    name);
901 				else if (dupsok == 1)
902 					mtree_warning(
903 					    "duplicate definition of %s",
904 					    name);
905 				return (0);
906 			}
907 
908 			if (node->type != S_IFDIR) {
909 				mtree_error("%s is not a directory", name);
910 				return (0);
911 			}
912 
913 			assert(!IS_DOT(name));
914 
915 			node = node->child;
916 
917 			assert(node != NULL);
918 			assert(IS_DOT(node->name));
919 
920 			mtree_current = node;
921 			return (0);
922 		}
923 
924 		last = node;
925 		node = last->next;
926 	}
927 
928 	parent = (mtree_current != NULL) ? mtree_current->parent : NULL;
929 	type = (def == false || IS_DOT(name)) ? S_IFDIR : 0;
930 	node = create_node(name, type, parent, &mtree_global);
931 	if (node == NULL)
932 		return (ENOMEM);
933 
934 	if (def == true) {
935 		error = read_mtree_keywords(fp, node);
936 		if (error) {
937 			destroy_node(node);
938 			return (error);
939 		}
940 	}
941 
942 	node->first = (mtree_current != NULL) ? mtree_current : node;
943 
944 	if (last != NULL)
945 		last->next = node;
946 
947 	if (node->type != S_IFDIR)
948 		return (0);
949 
950 	if (!IS_DOT(node->name)) {
951 		parent = node;
952 		node = create_node(".", S_IFDIR, parent, parent);
953 		if (node == NULL) {
954 			last->next = NULL;
955 			destroy_node(parent);
956 			return (ENOMEM);
957 		}
958 		parent->child = node;
959 		node->first = node;
960 	}
961 
962 	assert(node != NULL);
963 	assert(IS_DOT(node->name));
964 	assert(node->first == node);
965 
966 	mtree_current = node;
967 	if (mtree_root == NULL)
968 		mtree_root = node;
969 
970 	return (0);
971 }
972 
973 static int
974 read_mtree_spec(FILE *fp)
975 {
976 	char pathspec[PATH_MAX], pathtmp[4*PATH_MAX + 1];
977 	char *cp;
978 	int error;
979 
980 	error = read_word(fp, pathtmp, sizeof(pathtmp));
981 	if (error)
982 		goto out;
983 	if (strnunvis(pathspec, PATH_MAX, pathtmp) == -1) {
984 		error = errno;
985 		goto out;
986 	}
987 	error = 0;
988 
989 	cp = strchr(pathspec, '/');
990 	if (cp != NULL) {
991 		/* Absolute pathname */
992 		mtree_current = mtree_root;
993 
994 		do {
995 			*cp++ = '\0';
996 
997 			/* Disallow '..' as a component. */
998 			if (IS_DOTDOT(pathspec)) {
999 				mtree_error("absolute path cannot contain "
1000 				    ".. component");
1001 				goto out;
1002 			}
1003 
1004 			/* Ignore multiple adjacent slashes and '.'. */
1005 			if (pathspec[0] != '\0' && !IS_DOT(pathspec))
1006 				error = read_mtree_spec1(fp, false, pathspec);
1007 			memmove(pathspec, cp, strlen(cp) + 1);
1008 			cp = strchr(pathspec, '/');
1009 		} while (!error && cp != NULL);
1010 
1011 		/* Disallow '.' and '..' as the last component. */
1012 		if (!error && (IS_DOT(pathspec) || IS_DOTDOT(pathspec))) {
1013 			mtree_error("absolute path cannot contain . or .. "
1014 			    "components");
1015 			goto out;
1016 		}
1017 	}
1018 
1019 	/* Ignore absolute specifications that end with a slash. */
1020 	if (!error && pathspec[0] != '\0')
1021 		error = read_mtree_spec1(fp, true, pathspec);
1022 
1023  out:
1024 	skip_to(fp, "\n");
1025 	(void)getc(fp);
1026 	return (error);
1027 }
1028 
1029 fsnode *
1030 read_mtree(const char *fname, fsnode *node)
1031 {
1032 	struct mtree_fileinfo *fi;
1033 	FILE *fp;
1034 	int c, error;
1035 
1036 	/* We do not yet support nesting... */
1037 	assert(node == NULL);
1038 
1039 	if (strcmp(fname, "-") == 0)
1040 		fp = stdin;
1041 	else {
1042 		fp = fopen(fname, "r");
1043 		if (fp == NULL)
1044 			err(1, "Can't open `%s'", fname);
1045 	}
1046 
1047 	error = mtree_file_push(fname, fp);
1048 	if (error)
1049 		goto out;
1050 
1051 	memset(&mtree_global, 0, sizeof(mtree_global));
1052 	memset(&mtree_global_inode, 0, sizeof(mtree_global_inode));
1053 	mtree_global.inode = &mtree_global_inode;
1054 	mtree_global_inode.nlink = 1;
1055 	mtree_global_inode.st.st_nlink = 1;
1056 	mtree_global_inode.st.st_atime = mtree_global_inode.st.st_ctime =
1057 	    mtree_global_inode.st.st_mtime = time(NULL);
1058 	errors = warnings = 0;
1059 
1060 	setgroupent(1);
1061 	setpassent(1);
1062 
1063 	mtree_root = node;
1064 	mtree_current = node;
1065 	do {
1066 		/* Start of a new line... */
1067 		fi = SLIST_FIRST(&mtree_fileinfo);
1068 		fi->line++;
1069 
1070 		error = skip_over(fp, " \t");
1071 		if (error)
1072 			break;
1073 
1074 		c = getc(fp);
1075 		if (c == EOF) {
1076 			error = ferror(fp) ? errno : -1;
1077 			break;
1078 		}
1079 
1080 		switch (c) {
1081 		case '\n':		/* empty line */
1082 			error = 0;
1083 			break;
1084 		case '#':		/* comment -- skip to end of line. */
1085 			error = skip_to(fp, "\n");
1086 			if (!error)
1087 				(void)getc(fp);
1088 			break;
1089 		case '/':		/* special commands */
1090 			error = read_mtree_command(fp);
1091 			break;
1092 		default:		/* specification */
1093 			ungetc(c, fp);
1094 			error = read_mtree_spec(fp);
1095 			break;
1096 		}
1097 	} while (!error);
1098 
1099 	endpwent();
1100 	endgrent();
1101 
1102 	if (error <= 0 && (errors || warnings)) {
1103 		warnx("%u error(s) and %u warning(s) in mtree manifest",
1104 		    errors, warnings);
1105 		if (errors)
1106 			exit(1);
1107 	}
1108 
1109  out:
1110 	if (error > 0)
1111 		errc(1, error, "Error reading mtree file");
1112 
1113 	if (fp != stdin)
1114 		fclose(fp);
1115 
1116 	if (mtree_root != NULL)
1117 		return (mtree_root);
1118 
1119 	/* Handle empty specifications. */
1120 	node = create_node(".", S_IFDIR, NULL, &mtree_global);
1121 	node->first = node;
1122 	return (node);
1123 }
1124