xref: /freebsd/usr.sbin/autofs/common.c (revision 5608fd23c27fa1e8ee595d7b678cbfd35d657fbe)
1 /*-
2  * Copyright (c) 2014 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Edward Tomasz Napierala under sponsorship
6  * from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #include <sys/types.h>
33 #include <sys/time.h>
34 #include <sys/ioctl.h>
35 #include <sys/param.h>
36 #include <sys/linker.h>
37 #include <sys/mount.h>
38 #include <sys/socket.h>
39 #include <sys/stat.h>
40 #include <sys/wait.h>
41 #include <sys/utsname.h>
42 #include <assert.h>
43 #include <ctype.h>
44 #include <err.h>
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <libgen.h>
48 #include <netdb.h>
49 #include <paths.h>
50 #include <signal.h>
51 #include <stdbool.h>
52 #include <stdint.h>
53 #include <stdio.h>
54 #include <stdlib.h>
55 #include <string.h>
56 #include <unistd.h>
57 
58 #include <libutil.h>
59 
60 #include "autofs_ioctl.h"
61 
62 #include "common.h"
63 
64 extern FILE *yyin;
65 extern char *yytext;
66 extern int yylex(void);
67 
68 static void	parse_master_yyin(struct node *root, const char *master);
69 static void	parse_map_yyin(struct node *parent, const char *map,
70 		    const char *executable_key);
71 
72 char *
73 checked_strdup(const char *s)
74 {
75 	char *c;
76 
77 	assert(s != NULL);
78 
79 	c = strdup(s);
80 	if (c == NULL)
81 		log_err(1, "strdup");
82 	return (c);
83 }
84 
85 /*
86  * Take two pointers to strings, concatenate the contents with "/" in the
87  * middle, make the first pointer point to the result, the second pointer
88  * to NULL, and free the old strings.
89  *
90  * Concatenate pathnames, basically.
91  */
92 static void
93 concat(char **p1, char **p2)
94 {
95 	int ret;
96 	char *path;
97 
98 	assert(p1 != NULL);
99 	assert(p2 != NULL);
100 
101 	if (*p1 == NULL)
102 		*p1 = checked_strdup("");
103 
104 	if (*p2 == NULL)
105 		*p2 = checked_strdup("");
106 
107 	ret = asprintf(&path, "%s/%s", *p1, *p2);
108 	if (ret < 0)
109 		log_err(1, "asprintf");
110 
111 	/*
112 	 * XXX
113 	 */
114 	//free(*p1);
115 	//free(*p2);
116 
117 	*p1 = path;
118 	*p2 = NULL;
119 }
120 
121 /*
122  * Concatenate two strings, inserting separator between them, unless not needed.
123  *
124  * This function is very convenient to use when you do not care about freeing
125  * memory - which is okay here, because we are a short running process.
126  */
127 char *
128 separated_concat(const char *s1, const char *s2, char separator)
129 {
130 	char *result;
131 	int ret;
132 
133 	assert(s1 != NULL);
134 	assert(s2 != NULL);
135 
136 	if (s1[0] == '\0' || s2[0] == '\0' ||
137 	    s1[strlen(s1) - 1] == separator || s2[0] == separator) {
138 		ret = asprintf(&result, "%s%s", s1, s2);
139 	} else {
140 		ret = asprintf(&result, "%s%c%s", s1, separator, s2);
141 	}
142 	if (ret < 0)
143 		log_err(1, "asprintf");
144 
145 	//log_debugx("separated_concat: got %s and %s, returning %s", s1, s2, result);
146 
147 	return (result);
148 }
149 
150 void
151 create_directory(const char *path)
152 {
153 	char *component, *copy, *tofree, *partial;
154 	int error;
155 
156 	assert(path[0] == '/');
157 
158 	/*
159 	 * +1 to skip the leading slash.
160 	 */
161 	copy = tofree = checked_strdup(path + 1);
162 
163 	partial = NULL;
164 	for (;;) {
165 		component = strsep(&copy, "/");
166 		if (component == NULL)
167 			break;
168 		concat(&partial, &component);
169 		//log_debugx("checking \"%s\" for existence", partial);
170 		error = access(partial, F_OK);
171 		if (error == 0)
172 			continue;
173 		if (errno != ENOENT)
174 			log_err(1, "cannot access %s", partial);
175 		log_debugx("directory %s does not exist, creating",
176 		    partial);
177 		error = mkdir(partial, 0755);
178 		if (error != 0)
179 			log_err(1, "cannot create %s", partial);
180 	}
181 
182 	free(tofree);
183 }
184 
185 struct node *
186 node_new_root(void)
187 {
188 	struct node *n;
189 
190 	n = calloc(1, sizeof(*n));
191 	if (n == NULL)
192 		log_err(1, "calloc");
193 	// XXX
194 	n->n_key = checked_strdup("/");
195 	n->n_options = checked_strdup("");
196 
197 	TAILQ_INIT(&n->n_children);
198 
199 	return (n);
200 }
201 
202 struct node *
203 node_new(struct node *parent, char *key, char *options, char *location,
204     const char *config_file, int config_line)
205 {
206 	struct node *n;
207 
208 	n = calloc(1, sizeof(*n));
209 	if (n == NULL)
210 		log_err(1, "calloc");
211 
212 	TAILQ_INIT(&n->n_children);
213 	assert(key != NULL);
214 	n->n_key = key;
215 	if (options != NULL)
216 		n->n_options = options;
217 	else
218 		n->n_options = strdup("");
219 	n->n_location = location;
220 	assert(config_file != NULL);
221 	n->n_config_file = config_file;
222 	assert(config_line >= 0);
223 	n->n_config_line = config_line;
224 
225 	assert(parent != NULL);
226 	n->n_parent = parent;
227 	TAILQ_INSERT_TAIL(&parent->n_children, n, n_next);
228 
229 	return (n);
230 }
231 
232 struct node *
233 node_new_map(struct node *parent, char *key, char *options, char *map,
234     const char *config_file, int config_line)
235 {
236 	struct node *n;
237 
238 	n = calloc(1, sizeof(*n));
239 	if (n == NULL)
240 		log_err(1, "calloc");
241 
242 	TAILQ_INIT(&n->n_children);
243 	assert(key != NULL);
244 	n->n_key = key;
245 	if (options != NULL)
246 		n->n_options = options;
247 	else
248 		n->n_options = strdup("");
249 	n->n_map = map;
250 	assert(config_file != NULL);
251 	n->n_config_file = config_file;
252 	assert(config_line >= 0);
253 	n->n_config_line = config_line;
254 
255 	assert(parent != NULL);
256 	n->n_parent = parent;
257 	TAILQ_INSERT_TAIL(&parent->n_children, n, n_next);
258 
259 	return (n);
260 }
261 
262 static struct node *
263 node_duplicate(const struct node *o, struct node *parent)
264 {
265 	const struct node *child;
266 	struct node *n;
267 
268 	if (parent == NULL)
269 		parent = o->n_parent;
270 
271 	n = node_new(parent, o->n_key, o->n_options, o->n_location,
272 	    o->n_config_file, o->n_config_line);
273 
274 	TAILQ_FOREACH(child, &o->n_children, n_next)
275 		node_duplicate(child, n);
276 
277 	return (n);
278 }
279 
280 static void
281 node_delete(struct node *n)
282 {
283 	struct node *child, *tmp;
284 
285 	assert (n != NULL);
286 
287 	TAILQ_FOREACH_SAFE(child, &n->n_children, n_next, tmp)
288 		node_delete(child);
289 
290 	if (n->n_parent != NULL)
291 		TAILQ_REMOVE(&n->n_parent->n_children, n, n_next);
292 
293 	free(n);
294 }
295 
296 /*
297  * Move (reparent) node 'n' to make it sibling of 'previous', placed
298  * just after it.
299  */
300 static void
301 node_move_after(struct node *n, struct node *previous)
302 {
303 
304 	TAILQ_REMOVE(&n->n_parent->n_children, n, n_next);
305 	n->n_parent = previous->n_parent;
306 	TAILQ_INSERT_AFTER(&previous->n_parent->n_children, previous, n, n_next);
307 }
308 
309 static void
310 node_expand_includes(struct node *root, bool is_master)
311 {
312 	struct node *n, *n2, *tmp, *tmp2, *tmproot;
313 	int error;
314 
315 	TAILQ_FOREACH_SAFE(n, &root->n_children, n_next, tmp) {
316 		if (n->n_key[0] != '+')
317 			continue;
318 
319 		error = access(AUTO_INCLUDE_PATH, F_OK);
320 		if (error != 0) {
321 			log_errx(1, "directory services not configured; "
322 			    "%s does not exist", AUTO_INCLUDE_PATH);
323 		}
324 
325 		/*
326 		 * "+1" to skip leading "+".
327 		 */
328 		yyin = auto_popen(AUTO_INCLUDE_PATH, n->n_key + 1, NULL);
329 		assert(yyin != NULL);
330 
331 		tmproot = node_new_root();
332 		if (is_master)
333 			parse_master_yyin(tmproot, n->n_key);
334 		else
335 			parse_map_yyin(tmproot, n->n_key, NULL);
336 
337 		error = auto_pclose(yyin);
338 		yyin = NULL;
339 		if (error != 0) {
340 			log_errx(1, "failed to handle include \"%s\"",
341 			    n->n_key);
342 		}
343 
344 		/*
345 		 * Entries to be included are now in tmproot.  We need to merge
346 		 * them with the rest, preserving their place and ordering.
347 		 */
348 		TAILQ_FOREACH_REVERSE_SAFE(n2,
349 		    &tmproot->n_children, nodehead, n_next, tmp2) {
350 			node_move_after(n2, n);
351 		}
352 
353 		node_delete(n);
354 		node_delete(tmproot);
355 	}
356 }
357 
358 static char *
359 expand_ampersand(char *string, const char *key)
360 {
361 	char c, *expanded;
362 	int i, ret, before_len = 0;
363 	bool backslashed = false;
364 
365 	assert(key[0] != '\0');
366 
367 	expanded = checked_strdup(string);
368 
369 	for (i = 0; string[i] != '\0'; i++) {
370 		c = string[i];
371 		if (c == '\\' && backslashed == false) {
372 			backslashed = true;
373 			continue;
374 		}
375 		if (backslashed) {
376 			backslashed = false;
377 			continue;
378 		}
379 		backslashed = false;
380 		if (c != '&')
381 			continue;
382 
383 		/*
384 		 * The 'before_len' variable contains the number
385 		 * of characters before the '&'.
386 		 */
387 		before_len = i;
388 		//assert(i + 1 < (int)strlen(string));
389 
390 		ret = asprintf(&expanded, "%.*s%s%s",
391 		    before_len, string, key, string + before_len + 1);
392 		if (ret < 0)
393 			log_err(1, "asprintf");
394 
395 		//log_debugx("\"%s\" expanded with key \"%s\" to \"%s\"",
396 		//    string, key, expanded);
397 
398 		/*
399 		 * Figure out where to start searching for next variable.
400 		 */
401 		string = expanded;
402 		i = before_len + strlen(key);
403 		backslashed = false;
404 		//assert(i < (int)strlen(string));
405 	}
406 
407 	return (expanded);
408 }
409 
410 /*
411  * Expand "&" in n_location.  If the key is NULL, try to use
412  * key from map entries themselves.  Keep in mind that maps
413  * consist of tho levels of node structures, the key is one
414  * level up.
415  *
416  * Variant with NULL key is for "automount -LL".
417  */
418 void
419 node_expand_ampersand(struct node *n, const char *key)
420 {
421 	struct node *child;
422 
423 	if (n->n_location != NULL) {
424 		if (key == NULL) {
425 			if (n->n_parent != NULL &&
426 			    strcmp(n->n_parent->n_key, "*") != 0) {
427 				n->n_location = expand_ampersand(n->n_location,
428 				    n->n_parent->n_key);
429 			}
430 		} else {
431 			n->n_location = expand_ampersand(n->n_location, key);
432 		}
433 	}
434 
435 	TAILQ_FOREACH(child, &n->n_children, n_next)
436 		node_expand_ampersand(child, key);
437 }
438 
439 /*
440  * Expand "*" in n_key.
441  */
442 void
443 node_expand_wildcard(struct node *n, const char *key)
444 {
445 	struct node *child, *expanded;
446 
447 	assert(key != NULL);
448 
449 	if (strcmp(n->n_key, "*") == 0) {
450 		expanded = node_duplicate(n, NULL);
451 		expanded->n_key = checked_strdup(key);
452 		node_move_after(expanded, n);
453 	}
454 
455 	TAILQ_FOREACH(child, &n->n_children, n_next)
456 		node_expand_wildcard(child, key);
457 }
458 
459 int
460 node_expand_defined(struct node *n)
461 {
462 	struct node *child;
463 	int error, cumulated_error = 0;
464 
465 	if (n->n_location != NULL) {
466 		n->n_location = defined_expand(n->n_location);
467 		if (n->n_location == NULL) {
468 			log_warnx("failed to expand location for %s",
469 			    node_path(n));
470 			return (EINVAL);
471 		}
472 	}
473 
474 	TAILQ_FOREACH(child, &n->n_children, n_next) {
475 		error = node_expand_defined(child);
476 		if (error != 0 && cumulated_error == 0)
477 			cumulated_error = error;
478 	}
479 
480 	return (cumulated_error);
481 }
482 
483 bool
484 node_is_direct_map(const struct node *n)
485 {
486 
487 	for (;;) {
488 		assert(n->n_parent != NULL);
489 		if (n->n_parent->n_parent == NULL)
490 			break;
491 		n = n->n_parent;
492 	}
493 
494 	assert(n->n_key != NULL);
495 	if (strcmp(n->n_key, "/-") != 0)
496 		return (false);
497 
498 	return (true);
499 }
500 
501 static void
502 node_expand_maps(struct node *n, bool indirect)
503 {
504 	struct node *child, *tmp;
505 
506 	TAILQ_FOREACH_SAFE(child, &n->n_children, n_next, tmp) {
507 		if (node_is_direct_map(child)) {
508 			if (indirect)
509 				continue;
510 		} else {
511 			if (indirect == false)
512 				continue;
513 		}
514 
515 		/*
516 		 * This is the first-level map node; the one that contains
517 		 * the key and subnodes with mountpoints and actual map names.
518 		 */
519 		if (child->n_map == NULL)
520 			continue;
521 
522 		if (indirect) {
523 			log_debugx("map \"%s\" is an indirect map, parsing",
524 			    child->n_map);
525 		} else {
526 			log_debugx("map \"%s\" is a direct map, parsing",
527 			    child->n_map);
528 		}
529 		parse_map(child, child->n_map, NULL);
530 	}
531 }
532 
533 static void
534 node_expand_direct_maps(struct node *n)
535 {
536 
537 	node_expand_maps(n, false);
538 }
539 
540 void
541 node_expand_indirect_maps(struct node *n)
542 {
543 
544 	node_expand_maps(n, true);
545 }
546 
547 static char *
548 node_path_x(const struct node *n, char *x)
549 {
550 	char *path;
551 	size_t len;
552 
553 	if (n->n_parent == NULL)
554 		return (x);
555 
556 	/*
557 	 * Return "/-" for direct maps only if we were asked for path
558 	 * to the "/-" node itself, not to any of its subnodes.
559 	 */
560 	if (n->n_parent->n_parent == NULL &&
561 	    strcmp(n->n_key, "/-") == 0 &&
562 	    x[0] != '\0') {
563 		return (x);
564 	}
565 
566 	path = separated_concat(n->n_key, x, '/');
567 	free(x);
568 
569 	/*
570 	 * Strip trailing slash.
571 	 */
572 	len = strlen(path);
573 	assert(len > 0);
574 	if (path[len - 1] == '/')
575 		path[len - 1] = '\0';
576 
577 	return (node_path_x(n->n_parent, path));
578 }
579 
580 /*
581  * Return full path for node, consisting of concatenated
582  * paths of node itself and all its parents, up to the root.
583  */
584 char *
585 node_path(const struct node *n)
586 {
587 
588 	return (node_path_x(n, checked_strdup("")));
589 }
590 
591 static char *
592 node_options_x(const struct node *n, char *x)
593 {
594 	char *options;
595 
596 	options = separated_concat(x, n->n_options, ',');
597 	if (n->n_parent == NULL)
598 		return (options);
599 
600 	return (node_options_x(n->n_parent, options));
601 }
602 
603 /*
604  * Return options for node, consisting of concatenated
605  * options from the node itself and all its parents,
606  * up to the root.
607  */
608 char *
609 node_options(const struct node *n)
610 {
611 
612 	return (node_options_x(n, checked_strdup("")));
613 }
614 
615 static void
616 node_print_indent(const struct node *n, int indent)
617 {
618 	const struct node *child, *first_child;
619 	char *path, *options;
620 
621 	path = node_path(n);
622 	options = node_options(n);
623 
624 	/*
625 	 * Do not show both parent and child node if they have the same
626 	 * mountpoint; only show the child node.  This means the typical,
627 	 * "key location", map entries are shown in a single line;
628 	 * the "key mountpoint1 location2 mountpoint2 location2" entries
629 	 * take multiple lines.
630 	 */
631 	first_child = TAILQ_FIRST(&n->n_children);
632 	if (first_child == NULL || TAILQ_NEXT(first_child, n_next) != NULL ||
633 	    strcmp(path, node_path(first_child)) != 0) {
634 		assert(n->n_location == NULL || n->n_map == NULL);
635 		printf("%*.s%-*s %s%-*s %-*s # %s map %s at %s:%d\n",
636 		    indent, "",
637 		    25 - indent,
638 		    path,
639 		    options[0] != '\0' ? "-" : " ",
640 		    20,
641 		    options[0] != '\0' ? options : "",
642 		    20,
643 		    n->n_location != NULL ? n->n_location : n->n_map != NULL ? n->n_map : "",
644 		    node_is_direct_map(n) ? "direct" : "indirect",
645 		    indent == 0 ? "referenced" : "defined",
646 		    n->n_config_file, n->n_config_line);
647 	}
648 
649 	free(path);
650 	free(options);
651 
652 	TAILQ_FOREACH(child, &n->n_children, n_next)
653 		node_print_indent(child, indent + 2);
654 }
655 
656 void
657 node_print(const struct node *n)
658 {
659 	const struct node *child;
660 
661 	TAILQ_FOREACH(child, &n->n_children, n_next)
662 		node_print_indent(child, 0);
663 }
664 
665 struct node *
666 node_find(struct node *node, const char *path)
667 {
668 	struct node *child, *found;
669 	char *tmp;
670 
671 	//log_debugx("looking up %s in %s", path, node->n_key);
672 
673 	tmp = node_path(node);
674 	if (strncmp(tmp, path, strlen(tmp)) != 0) {
675 		free(tmp);
676 		return (NULL);
677 	}
678 	free(tmp);
679 
680 	TAILQ_FOREACH(child, &node->n_children, n_next) {
681 		found = node_find(child, path);
682 		if (found != NULL)
683 			return (found);
684 	}
685 
686 	return (node);
687 }
688 
689 /*
690  * Canonical form of a map entry looks like this:
691  *
692  * key [-options] [ [/mountpoint] [-options2] location ... ]
693  *
694  * Entries for executable maps are slightly different, as they
695  * lack the 'key' field and are always single-line; the key field
696  * for those maps is taken from 'executable_key' argument.
697  *
698  * We parse it in such a way that a map always has two levels - first
699  * for key, and the second, for the mountpoint.
700  */
701 static void
702 parse_map_yyin(struct node *parent, const char *map, const char *executable_key)
703 {
704 	char *key = NULL, *options = NULL, *mountpoint = NULL,
705 	    *options2 = NULL, *location = NULL;
706 	int ret;
707 	struct node *node;
708 
709 	lineno = 1;
710 
711 	if (executable_key != NULL)
712 		key = checked_strdup(executable_key);
713 
714 	for (;;) {
715 		ret = yylex();
716 		if (ret == 0 || ret == NEWLINE) {
717 			if (key != NULL || options != NULL) {
718 				log_errx(1, "truncated entry at %s, line %d",
719 				    map, lineno);
720 			}
721 			if (ret == 0 || executable_key != NULL) {
722 				/*
723 				 * End of file.
724 				 */
725 				break;
726 			} else {
727 				key = options = NULL;
728 				continue;
729 			}
730 		}
731 		if (key == NULL) {
732 			key = checked_strdup(yytext);
733 			if (key[0] == '+') {
734 				node_new(parent, key, NULL, NULL, map, lineno);
735 				key = options = NULL;
736 				continue;
737 			}
738 			continue;
739 		} else if (yytext[0] == '-') {
740 			if (options != NULL) {
741 				log_errx(1, "duplicated options at %s, line %d",
742 				    map, lineno);
743 			}
744 			/*
745 			 * +1 to skip leading "-".
746 			 */
747 			options = checked_strdup(yytext + 1);
748 			continue;
749 		}
750 
751 		/*
752 		 * We cannot properly handle a situation where the map key
753 		 * is "/".  Ignore such entries.
754 		 *
755 		 * XXX: According to Piete Brooks, Linux automounter uses
756 		 *	"/" as a wildcard character in LDAP maps.  Perhaps
757 		 *	we should work around this braindamage by substituting
758 		 *	"*" for "/"?
759 		 */
760 		if (strcmp(key, "/") == 0) {
761 			log_warnx("nonsensical map key \"/\" at %s, line %d; "
762 			    "ignoring map entry ", map, lineno);
763 
764 			/*
765 			 * Skip the rest of the entry.
766 			 */
767 			do {
768 				ret = yylex();
769 			} while (ret != 0 && ret != NEWLINE);
770 
771 			key = options = NULL;
772 			continue;
773 		}
774 
775 		//log_debugx("adding map node, %s", key);
776 		node = node_new(parent, key, options, NULL, map, lineno);
777 		key = options = NULL;
778 
779 		for (;;) {
780 			if (yytext[0] == '/') {
781 				if (mountpoint != NULL) {
782 					log_errx(1, "duplicated mountpoint "
783 					    "in %s, line %d", map, lineno);
784 				}
785 				if (options2 != NULL || location != NULL) {
786 					log_errx(1, "mountpoint out of order "
787 					    "in %s, line %d", map, lineno);
788 				}
789 				mountpoint = checked_strdup(yytext);
790 				goto again;
791 			}
792 
793 			if (yytext[0] == '-') {
794 				if (options2 != NULL) {
795 					log_errx(1, "duplicated options "
796 					    "in %s, line %d", map, lineno);
797 				}
798 				if (location != NULL) {
799 					log_errx(1, "options out of order "
800 					    "in %s, line %d", map, lineno);
801 				}
802 				options2 = checked_strdup(yytext + 1);
803 				goto again;
804 			}
805 
806 			if (location != NULL) {
807 				log_errx(1, "too many arguments "
808 				    "in %s, line %d", map, lineno);
809 			}
810 
811 			/*
812 			 * If location field starts with colon, e.g. ":/dev/cd0",
813 			 * then strip it.
814 			 */
815 			if (yytext[0] == ':') {
816 				location = checked_strdup(yytext + 1);
817 				if (location[0] == '\0') {
818 					log_errx(1, "empty location in %s, "
819 					    "line %d", map, lineno);
820 				}
821 			} else {
822 				location = checked_strdup(yytext);
823 			}
824 
825 			if (mountpoint == NULL)
826 				mountpoint = checked_strdup("/");
827 			if (options2 == NULL)
828 				options2 = checked_strdup("");
829 
830 #if 0
831 			log_debugx("adding map node, %s %s %s",
832 			    mountpoint, options2, location);
833 #endif
834 			node_new(node, mountpoint, options2, location,
835 			    map, lineno);
836 			mountpoint = options2 = location = NULL;
837 again:
838 			ret = yylex();
839 			if (ret == 0 || ret == NEWLINE) {
840 				if (mountpoint != NULL || options2 != NULL ||
841 				    location != NULL) {
842 					log_errx(1, "truncated entry "
843 					    "in %s, line %d", map, lineno);
844 				}
845 				break;
846 			}
847 		}
848 	}
849 }
850 
851 static bool
852 file_is_executable(const char *path)
853 {
854 	struct stat sb;
855 	int error;
856 
857 	error = stat(path, &sb);
858 	if (error != 0)
859 		log_err(1, "cannot stat %s", path);
860 	if ((sb.st_mode & S_IXUSR) || (sb.st_mode & S_IXGRP) ||
861 	    (sb.st_mode & S_IXOTH))
862 		return (true);
863 	return (false);
864 }
865 
866 /*
867  * Parse a special map, e.g. "-hosts".
868  */
869 static void
870 parse_special_map(struct node *parent, const char *map, const char *key)
871 {
872 	char *path;
873 	int error, ret;
874 
875 	assert(map[0] == '-');
876 
877 	if (key == NULL) {
878 		log_debugx("skipping map %s due to forced -nobrowse", map);
879 		return;
880 	}
881 
882 	/*
883 	 * +1 to skip leading "-" in map name.
884 	 */
885 	ret = asprintf(&path, "%s/special_%s", AUTO_SPECIAL_PREFIX, map + 1);
886 	if (ret < 0)
887 		log_err(1, "asprintf");
888 
889 	yyin = auto_popen(path, key, NULL);
890 	assert(yyin != NULL);
891 
892 	parse_map_yyin(parent, map, key);
893 
894 	error = auto_pclose(yyin);
895 	yyin = NULL;
896 	if (error != 0)
897 		log_errx(1, "failed to handle special map \"%s\"", map);
898 
899 	node_expand_includes(parent, false);
900 	node_expand_direct_maps(parent);
901 
902 	free(path);
903 }
904 
905 /*
906  * Retrieve and parse map from directory services, e.g. LDAP.
907  * Note that it is different from executable maps, in that
908  * the include script outputs the whole map to standard output
909  * (as opposed to executable maps that only output a single
910  * entry, without the key), and it takes the map name as an
911  * argument, instead of key.
912  */
913 static void
914 parse_included_map(struct node *parent, const char *map)
915 {
916 	int error;
917 
918 	assert(map[0] != '-');
919 	assert(map[0] != '/');
920 
921 	error = access(AUTO_INCLUDE_PATH, F_OK);
922 	if (error != 0) {
923 		log_errx(1, "directory services not configured;"
924 		    " %s does not exist", AUTO_INCLUDE_PATH);
925 	}
926 
927 	yyin = auto_popen(AUTO_INCLUDE_PATH, map, NULL);
928 	assert(yyin != NULL);
929 
930 	parse_map_yyin(parent, map, NULL);
931 
932 	error = auto_pclose(yyin);
933 	yyin = NULL;
934 	if (error != 0)
935 		log_errx(1, "failed to handle remote map \"%s\"", map);
936 
937 	node_expand_includes(parent, false);
938 	node_expand_direct_maps(parent);
939 }
940 
941 void
942 parse_map(struct node *parent, const char *map, const char *key)
943 {
944 	char *path = NULL;
945 	int error, ret;
946 	bool executable;
947 
948 	assert(map != NULL);
949 	assert(map[0] != '\0');
950 
951 	log_debugx("parsing map \"%s\"", map);
952 
953 	if (map[0] == '-')
954 		return (parse_special_map(parent, map, key));
955 
956 	if (map[0] == '/') {
957 		path = checked_strdup(map);
958 	} else {
959 		ret = asprintf(&path, "%s/%s", AUTO_MAP_PREFIX, map);
960 		if (ret < 0)
961 			log_err(1, "asprintf");
962 		log_debugx("map \"%s\" maps to \"%s\"", map, path);
963 
964 		/*
965 		 * See if the file exists.  If not, try to obtain the map
966 		 * from directory services.
967 		 */
968 		error = access(path, F_OK);
969 		if (error != 0) {
970 			log_debugx("map file \"%s\" does not exist; falling "
971 			    "back to directory services", path);
972 			return (parse_included_map(parent, map));
973 		}
974 	}
975 
976 	executable = file_is_executable(path);
977 
978 	if (executable) {
979 		log_debugx("map \"%s\" is executable", map);
980 
981 		if (key != NULL) {
982 			yyin = auto_popen(path, key, NULL);
983 		} else {
984 			yyin = auto_popen(path, NULL);
985 		}
986 		assert(yyin != NULL);
987 	} else {
988 		yyin = fopen(path, "r");
989 		if (yyin == NULL)
990 			log_err(1, "unable to open \"%s\"", path);
991 	}
992 
993 	free(path);
994 	path = NULL;
995 
996 	parse_map_yyin(parent, map, executable ? key : NULL);
997 
998 	if (executable) {
999 		error = auto_pclose(yyin);
1000 		yyin = NULL;
1001 		if (error != 0) {
1002 			log_errx(1, "failed to handle executable map \"%s\"",
1003 			    map);
1004 		}
1005 	} else {
1006 		fclose(yyin);
1007 	}
1008 	yyin = NULL;
1009 
1010 	log_debugx("done parsing map \"%s\"", map);
1011 
1012 	node_expand_includes(parent, false);
1013 	node_expand_direct_maps(parent);
1014 }
1015 
1016 static void
1017 parse_master_yyin(struct node *root, const char *master)
1018 {
1019 	char *mountpoint = NULL, *map = NULL, *options = NULL;
1020 	int ret;
1021 
1022 	/*
1023 	 * XXX: 1 gives incorrect values; wtf?
1024 	 */
1025 	lineno = 0;
1026 
1027 	for (;;) {
1028 		ret = yylex();
1029 		if (ret == 0 || ret == NEWLINE) {
1030 			if (mountpoint != NULL) {
1031 				//log_debugx("adding map for %s", mountpoint);
1032 				node_new_map(root, mountpoint, options, map,
1033 				    master, lineno);
1034 			}
1035 			if (ret == 0) {
1036 				break;
1037 			} else {
1038 				mountpoint = map = options = NULL;
1039 				continue;
1040 			}
1041 		}
1042 		if (mountpoint == NULL) {
1043 			mountpoint = checked_strdup(yytext);
1044 		} else if (map == NULL) {
1045 			map = checked_strdup(yytext);
1046 		} else if (options == NULL) {
1047 			/*
1048 			 * +1 to skip leading "-".
1049 			 */
1050 			options = checked_strdup(yytext + 1);
1051 		} else {
1052 			log_errx(1, "too many arguments at %s, line %d",
1053 			    master, lineno);
1054 		}
1055 	}
1056 }
1057 
1058 void
1059 parse_master(struct node *root, const char *master)
1060 {
1061 
1062 	log_debugx("parsing auto_master file at \"%s\"", master);
1063 
1064 	yyin = fopen(master, "r");
1065 	if (yyin == NULL)
1066 		err(1, "unable to open %s", master);
1067 
1068 	parse_master_yyin(root, master);
1069 
1070 	fclose(yyin);
1071 	yyin = NULL;
1072 
1073 	log_debugx("done parsing \"%s\"", master);
1074 
1075 	node_expand_includes(root, true);
1076 	node_expand_direct_maps(root);
1077 }
1078 
1079 /*
1080  * Two things daemon(3) does, that we actually also want to do
1081  * when running in foreground, is closing the stdin and chdiring
1082  * to "/".  This is what we do here.
1083  */
1084 void
1085 lesser_daemon(void)
1086 {
1087 	int error, fd;
1088 
1089 	error = chdir("/");
1090 	if (error != 0)
1091 		log_warn("chdir");
1092 
1093 	fd = open(_PATH_DEVNULL, O_RDWR, 0);
1094 	if (fd < 0) {
1095 		log_warn("cannot open %s", _PATH_DEVNULL);
1096 		return;
1097 	}
1098 
1099 	error = dup2(fd, STDIN_FILENO);
1100 	if (error != 0)
1101 		log_warn("dup2");
1102 
1103 	error = close(fd);
1104 	if (error != 0) {
1105 		/* Bloody hell. */
1106 		log_warn("close");
1107 	}
1108 }
1109 
1110 int
1111 main(int argc, char **argv)
1112 {
1113 	char *cmdname;
1114 
1115 	if (argv[0] == NULL)
1116 		log_errx(1, "NULL command name");
1117 
1118 	cmdname = basename(argv[0]);
1119 
1120 	if (strcmp(cmdname, "automount") == 0)
1121 		return (main_automount(argc, argv));
1122 	else if (strcmp(cmdname, "automountd") == 0)
1123 		return (main_automountd(argc, argv));
1124 	else if (strcmp(cmdname, "autounmountd") == 0)
1125 		return (main_autounmountd(argc, argv));
1126 	else
1127 		log_errx(1, "binary name should be either \"automount\", "
1128 		    "\"automountd\", or \"autounmountd\"");
1129 }
1130