xref: /freebsd/usr.sbin/autofs/common.c (revision 7ebeea9a)
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  */
30 
31 #include <sys/cdefs.h>
32 __FBSDID("$FreeBSD$");
33 
34 #include <sys/types.h>
35 #include <sys/time.h>
36 #include <sys/ioctl.h>
37 #include <sys/param.h>
38 #include <sys/linker.h>
39 #include <sys/mount.h>
40 #include <sys/socket.h>
41 #include <sys/stat.h>
42 #include <sys/wait.h>
43 #include <sys/utsname.h>
44 #include <assert.h>
45 #include <ctype.h>
46 #include <err.h>
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <libgen.h>
50 #include <netdb.h>
51 #include <paths.h>
52 #include <signal.h>
53 #include <stdbool.h>
54 #include <stdint.h>
55 #define	_WITH_GETLINE
56 #include <stdio.h>
57 #include <stdlib.h>
58 #include <string.h>
59 #include <unistd.h>
60 
61 #include <libutil.h>
62 
63 #include "autofs_ioctl.h"
64 
65 #include "common.h"
66 
67 extern FILE *yyin;
68 extern char *yytext;
69 extern int yylex(void);
70 
71 static void	parse_master_yyin(struct node *root, const char *master);
72 static void	parse_map_yyin(struct node *parent, const char *map,
73 		    const char *executable_key);
74 
75 char *
76 checked_strdup(const char *s)
77 {
78 	char *c;
79 
80 	assert(s != NULL);
81 
82 	c = strdup(s);
83 	if (c == NULL)
84 		log_err(1, "strdup");
85 	return (c);
86 }
87 
88 /*
89  * Take two pointers to strings, concatenate the contents with "/" in the
90  * middle, make the first pointer point to the result, the second pointer
91  * to NULL, and free the old strings.
92  *
93  * Concatenate pathnames, basically.
94  */
95 static void
96 concat(char **p1, char **p2)
97 {
98 	int ret;
99 	char *path;
100 
101 	assert(p1 != NULL);
102 	assert(p2 != NULL);
103 
104 	if (*p1 == NULL)
105 		*p1 = checked_strdup("");
106 
107 	if (*p2 == NULL)
108 		*p2 = checked_strdup("");
109 
110 	ret = asprintf(&path, "%s/%s", *p1, *p2);
111 	if (ret < 0)
112 		log_err(1, "asprintf");
113 
114 	/*
115 	 * XXX
116 	 */
117 	//free(*p1);
118 	//free(*p2);
119 
120 	*p1 = path;
121 	*p2 = NULL;
122 }
123 
124 /*
125  * Concatenate two strings, inserting separator between them, unless not needed.
126  *
127  * This function is very convenient to use when you do not care about freeing
128  * memory - which is okay here, because we are a short running process.
129  */
130 char *
131 separated_concat(const char *s1, const char *s2, char separator)
132 {
133 	char *result;
134 	int ret;
135 
136 	assert(s1 != NULL);
137 	assert(s2 != NULL);
138 
139 	if (s1[0] == '\0' || s2[0] == '\0' ||
140 	    s1[strlen(s1) - 1] == separator || s2[0] == separator) {
141 		ret = asprintf(&result, "%s%s", s1, s2);
142 	} else {
143 		ret = asprintf(&result, "%s%c%s", s1, separator, s2);
144 	}
145 	if (ret < 0)
146 		log_err(1, "asprintf");
147 
148 	//log_debugx("separated_concat: got %s and %s, returning %s", s1, s2, result);
149 
150 	return (result);
151 }
152 
153 void
154 create_directory(const char *path)
155 {
156 	char *component, *copy, *tofree, *partial;
157 	int error;
158 
159 	assert(path[0] == '/');
160 
161 	/*
162 	 * +1 to skip the leading slash.
163 	 */
164 	copy = tofree = checked_strdup(path + 1);
165 
166 	partial = NULL;
167 	for (;;) {
168 		component = strsep(&copy, "/");
169 		if (component == NULL)
170 			break;
171 		concat(&partial, &component);
172 		//log_debugx("creating \"%s\"", partial);
173 		error = mkdir(partial, 0755);
174 		if (error != 0 && errno != EEXIST) {
175 			log_warn("cannot create %s", partial);
176 			return;
177 		}
178 	}
179 
180 	free(tofree);
181 }
182 
183 struct node *
184 node_new_root(void)
185 {
186 	struct node *n;
187 
188 	n = calloc(1, sizeof(*n));
189 	if (n == NULL)
190 		log_err(1, "calloc");
191 	// XXX
192 	n->n_key = checked_strdup("/");
193 	n->n_options = checked_strdup("");
194 
195 	TAILQ_INIT(&n->n_children);
196 
197 	return (n);
198 }
199 
200 struct node *
201 node_new(struct node *parent, char *key, char *options, char *location,
202     const char *config_file, int config_line)
203 {
204 	struct node *n;
205 
206 	n = calloc(1, sizeof(*n));
207 	if (n == NULL)
208 		log_err(1, "calloc");
209 
210 	TAILQ_INIT(&n->n_children);
211 	assert(key != NULL);
212 	assert(key[0] != '\0');
213 	n->n_key = key;
214 	if (options != NULL)
215 		n->n_options = options;
216 	else
217 		n->n_options = strdup("");
218 	n->n_location = location;
219 	assert(config_file != NULL);
220 	n->n_config_file = config_file;
221 	assert(config_line >= 0);
222 	n->n_config_line = config_line;
223 
224 	assert(parent != NULL);
225 	n->n_parent = parent;
226 	TAILQ_INSERT_TAIL(&parent->n_children, n, n_next);
227 
228 	return (n);
229 }
230 
231 struct node *
232 node_new_map(struct node *parent, char *key, char *options, char *map,
233     const char *config_file, int config_line)
234 {
235 	struct node *n;
236 
237 	n = calloc(1, sizeof(*n));
238 	if (n == NULL)
239 		log_err(1, "calloc");
240 
241 	TAILQ_INIT(&n->n_children);
242 	assert(key != NULL);
243 	assert(key[0] != '\0');
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 	assert(n->n_key[0] != '\0');
567 	path = separated_concat(n->n_key, x, '/');
568 	free(x);
569 
570 	/*
571 	 * Strip trailing slash.
572 	 */
573 	len = strlen(path);
574 	assert(len > 0);
575 	if (path[len - 1] == '/')
576 		path[len - 1] = '\0';
577 
578 	return (node_path_x(n->n_parent, path));
579 }
580 
581 /*
582  * Return full path for node, consisting of concatenated
583  * paths of node itself and all its parents, up to the root.
584  */
585 char *
586 node_path(const struct node *n)
587 {
588 
589 	return (node_path_x(n, checked_strdup("")));
590 }
591 
592 static char *
593 node_options_x(const struct node *n, char *x)
594 {
595 	char *options;
596 
597 	options = separated_concat(x, n->n_options, ',');
598 	if (n->n_parent == NULL)
599 		return (options);
600 
601 	return (node_options_x(n->n_parent, options));
602 }
603 
604 /*
605  * Return options for node, consisting of concatenated
606  * options from the node itself and all its parents,
607  * up to the root.
608  */
609 char *
610 node_options(const struct node *n)
611 {
612 
613 	return (node_options_x(n, checked_strdup("")));
614 }
615 
616 static void
617 node_print_indent(const struct node *n, int indent)
618 {
619 	const struct node *child, *first_child;
620 	char *path, *options;
621 
622 	path = node_path(n);
623 	options = node_options(n);
624 
625 	/*
626 	 * Do not show both parent and child node if they have the same
627 	 * mountpoint; only show the child node.  This means the typical,
628 	 * "key location", map entries are shown in a single line;
629 	 * the "key mountpoint1 location2 mountpoint2 location2" entries
630 	 * take multiple lines.
631 	 */
632 	first_child = TAILQ_FIRST(&n->n_children);
633 	if (first_child == NULL || TAILQ_NEXT(first_child, n_next) != NULL ||
634 	    strcmp(path, node_path(first_child)) != 0) {
635 		assert(n->n_location == NULL || n->n_map == NULL);
636 		printf("%*.s%-*s %s%-*s %-*s # %s map %s at %s:%d\n",
637 		    indent, "",
638 		    25 - indent,
639 		    path,
640 		    options[0] != '\0' ? "-" : " ",
641 		    20,
642 		    options[0] != '\0' ? options : "",
643 		    20,
644 		    n->n_location != NULL ? n->n_location : n->n_map != NULL ? n->n_map : "",
645 		    node_is_direct_map(n) ? "direct" : "indirect",
646 		    indent == 0 ? "referenced" : "defined",
647 		    n->n_config_file, n->n_config_line);
648 	}
649 
650 	free(path);
651 	free(options);
652 
653 	TAILQ_FOREACH(child, &n->n_children, n_next)
654 		node_print_indent(child, indent + 2);
655 }
656 
657 void
658 node_print(const struct node *n)
659 {
660 	const struct node *child;
661 
662 	TAILQ_FOREACH(child, &n->n_children, n_next)
663 		node_print_indent(child, 0);
664 }
665 
666 struct node *
667 node_find(struct node *node, const char *path)
668 {
669 	struct node *child, *found;
670 	char *tmp;
671 	size_t tmplen;
672 
673 	//log_debugx("looking up %s in %s", path, node->n_key);
674 
675 	tmp = node_path(node);
676 	tmplen = strlen(tmp);
677 	if (strncmp(tmp, path, tmplen) != 0) {
678 		free(tmp);
679 		return (NULL);
680 	}
681 	if (path[tmplen] != '/' && path[tmplen] != '\0') {
682 		/*
683 		 * If we have two map entries like 'foo' and 'foobar', make
684 		 * sure the search for 'foobar' won't match 'foo' instead.
685 		 */
686 		free(tmp);
687 		return (NULL);
688 	}
689 	free(tmp);
690 
691 	TAILQ_FOREACH(child, &node->n_children, n_next) {
692 		found = node_find(child, path);
693 		if (found != NULL)
694 			return (found);
695 	}
696 
697 	return (node);
698 }
699 
700 /*
701  * Canonical form of a map entry looks like this:
702  *
703  * key [-options] [ [/mountpoint] [-options2] location ... ]
704  *
705  * Entries for executable maps are slightly different, as they
706  * lack the 'key' field and are always single-line; the key field
707  * for those maps is taken from 'executable_key' argument.
708  *
709  * We parse it in such a way that a map always has two levels - first
710  * for key, and the second, for the mountpoint.
711  */
712 static void
713 parse_map_yyin(struct node *parent, const char *map, const char *executable_key)
714 {
715 	char *key = NULL, *options = NULL, *mountpoint = NULL,
716 	    *options2 = NULL, *location = NULL;
717 	int ret;
718 	struct node *node;
719 
720 	lineno = 1;
721 
722 	if (executable_key != NULL)
723 		key = checked_strdup(executable_key);
724 
725 	for (;;) {
726 		ret = yylex();
727 		if (ret == 0 || ret == NEWLINE) {
728 			/*
729 			 * In case of executable map, the key is always
730 			 * non-NULL, even if the map is empty.  So, make sure
731 			 * we don't fail empty maps here.
732 			 */
733 			if ((key != NULL && executable_key == NULL) ||
734 			    options != NULL) {
735 				log_errx(1, "truncated entry at %s, line %d",
736 				    map, lineno);
737 			}
738 			if (ret == 0 || executable_key != NULL) {
739 				/*
740 				 * End of file.
741 				 */
742 				break;
743 			} else {
744 				key = options = NULL;
745 				continue;
746 			}
747 		}
748 		if (key == NULL) {
749 			key = checked_strdup(yytext);
750 			if (key[0] == '+') {
751 				node_new(parent, key, NULL, NULL, map, lineno);
752 				key = options = NULL;
753 				continue;
754 			}
755 			continue;
756 		} else if (yytext[0] == '-') {
757 			if (options != NULL) {
758 				log_errx(1, "duplicated options at %s, line %d",
759 				    map, lineno);
760 			}
761 			/*
762 			 * +1 to skip leading "-".
763 			 */
764 			options = checked_strdup(yytext + 1);
765 			continue;
766 		}
767 
768 		/*
769 		 * We cannot properly handle a situation where the map key
770 		 * is "/".  Ignore such entries.
771 		 *
772 		 * XXX: According to Piete Brooks, Linux automounter uses
773 		 *	"/" as a wildcard character in LDAP maps.  Perhaps
774 		 *	we should work around this braindamage by substituting
775 		 *	"*" for "/"?
776 		 */
777 		if (strcmp(key, "/") == 0) {
778 			log_warnx("nonsensical map key \"/\" at %s, line %d; "
779 			    "ignoring map entry ", map, lineno);
780 
781 			/*
782 			 * Skip the rest of the entry.
783 			 */
784 			do {
785 				ret = yylex();
786 			} while (ret != 0 && ret != NEWLINE);
787 
788 			key = options = NULL;
789 			continue;
790 		}
791 
792 		//log_debugx("adding map node, %s", key);
793 		node = node_new(parent, key, options, NULL, map, lineno);
794 		key = options = NULL;
795 
796 		for (;;) {
797 			if (yytext[0] == '/') {
798 				if (mountpoint != NULL) {
799 					log_errx(1, "duplicated mountpoint "
800 					    "in %s, line %d", map, lineno);
801 				}
802 				if (options2 != NULL || location != NULL) {
803 					log_errx(1, "mountpoint out of order "
804 					    "in %s, line %d", map, lineno);
805 				}
806 				mountpoint = checked_strdup(yytext);
807 				goto again;
808 			}
809 
810 			if (yytext[0] == '-') {
811 				if (options2 != NULL) {
812 					log_errx(1, "duplicated options "
813 					    "in %s, line %d", map, lineno);
814 				}
815 				if (location != NULL) {
816 					log_errx(1, "options out of order "
817 					    "in %s, line %d", map, lineno);
818 				}
819 				options2 = checked_strdup(yytext + 1);
820 				goto again;
821 			}
822 
823 			if (location != NULL) {
824 				log_errx(1, "too many arguments "
825 				    "in %s, line %d", map, lineno);
826 			}
827 
828 			/*
829 			 * If location field starts with colon, e.g. ":/dev/cd0",
830 			 * then strip it.
831 			 */
832 			if (yytext[0] == ':') {
833 				location = checked_strdup(yytext + 1);
834 				if (location[0] == '\0') {
835 					log_errx(1, "empty location in %s, "
836 					    "line %d", map, lineno);
837 				}
838 			} else {
839 				location = checked_strdup(yytext);
840 			}
841 
842 			if (mountpoint == NULL)
843 				mountpoint = checked_strdup("/");
844 			if (options2 == NULL)
845 				options2 = checked_strdup("");
846 
847 #if 0
848 			log_debugx("adding map node, %s %s %s",
849 			    mountpoint, options2, location);
850 #endif
851 			node_new(node, mountpoint, options2, location,
852 			    map, lineno);
853 			mountpoint = options2 = location = NULL;
854 again:
855 			ret = yylex();
856 			if (ret == 0 || ret == NEWLINE) {
857 				if (mountpoint != NULL || options2 != NULL ||
858 				    location != NULL) {
859 					log_errx(1, "truncated entry "
860 					    "in %s, line %d", map, lineno);
861 				}
862 				break;
863 			}
864 		}
865 	}
866 }
867 
868 /*
869  * Parse output of a special map called without argument.  It is a list
870  * of keys, separated by newlines.  They can contain whitespace, so use
871  * getline(3) instead of lexer used for maps.
872  */
873 static void
874 parse_map_keys_yyin(struct node *parent, const char *map)
875 {
876 	char *line = NULL, *key;
877 	size_t linecap = 0;
878 	ssize_t linelen;
879 
880 	lineno = 1;
881 
882 	for (;;) {
883 		linelen = getline(&line, &linecap, yyin);
884 		if (linelen < 0) {
885 			/*
886 			 * End of file.
887 			 */
888 			break;
889 		}
890 		if (linelen <= 1) {
891 			/*
892 			 * Empty line, consisting of just the newline.
893 			 */
894 			continue;
895 		}
896 
897 		/*
898 		 * "-1" to strip the trailing newline.
899 		 */
900 		key = strndup(line, linelen - 1);
901 
902 		log_debugx("adding key \"%s\"", key);
903 		node_new(parent, key, NULL, NULL, map, lineno);
904 		lineno++;
905 	}
906 	free(line);
907 }
908 
909 static bool
910 file_is_executable(const char *path)
911 {
912 	struct stat sb;
913 	int error;
914 
915 	error = stat(path, &sb);
916 	if (error != 0)
917 		log_err(1, "cannot stat %s", path);
918 	if ((sb.st_mode & S_IXUSR) || (sb.st_mode & S_IXGRP) ||
919 	    (sb.st_mode & S_IXOTH))
920 		return (true);
921 	return (false);
922 }
923 
924 /*
925  * Parse a special map, e.g. "-hosts".
926  */
927 static void
928 parse_special_map(struct node *parent, const char *map, const char *key)
929 {
930 	char *path;
931 	int error, ret;
932 
933 	assert(map[0] == '-');
934 
935 	/*
936 	 * +1 to skip leading "-" in map name.
937 	 */
938 	ret = asprintf(&path, "%s/special_%s", AUTO_SPECIAL_PREFIX, map + 1);
939 	if (ret < 0)
940 		log_err(1, "asprintf");
941 
942 	yyin = auto_popen(path, key, NULL);
943 	assert(yyin != NULL);
944 
945 	if (key == NULL) {
946 		parse_map_keys_yyin(parent, map);
947 	} else {
948 		parse_map_yyin(parent, map, key);
949 	}
950 
951 	error = auto_pclose(yyin);
952 	yyin = NULL;
953 	if (error != 0)
954 		log_errx(1, "failed to handle special map \"%s\"", map);
955 
956 	node_expand_includes(parent, false);
957 	node_expand_direct_maps(parent);
958 
959 	free(path);
960 }
961 
962 /*
963  * Retrieve and parse map from directory services, e.g. LDAP.
964  * Note that it is different from executable maps, in that
965  * the include script outputs the whole map to standard output
966  * (as opposed to executable maps that only output a single
967  * entry, without the key), and it takes the map name as an
968  * argument, instead of key.
969  */
970 static void
971 parse_included_map(struct node *parent, const char *map)
972 {
973 	int error;
974 
975 	assert(map[0] != '-');
976 	assert(map[0] != '/');
977 
978 	error = access(AUTO_INCLUDE_PATH, F_OK);
979 	if (error != 0) {
980 		log_errx(1, "directory services not configured;"
981 		    " %s does not exist", AUTO_INCLUDE_PATH);
982 	}
983 
984 	yyin = auto_popen(AUTO_INCLUDE_PATH, map, NULL);
985 	assert(yyin != NULL);
986 
987 	parse_map_yyin(parent, map, NULL);
988 
989 	error = auto_pclose(yyin);
990 	yyin = NULL;
991 	if (error != 0)
992 		log_errx(1, "failed to handle remote map \"%s\"", map);
993 
994 	node_expand_includes(parent, false);
995 	node_expand_direct_maps(parent);
996 }
997 
998 void
999 parse_map(struct node *parent, const char *map, const char *key)
1000 {
1001 	char *path = NULL;
1002 	int error, ret;
1003 	bool executable;
1004 
1005 	assert(map != NULL);
1006 	assert(map[0] != '\0');
1007 
1008 	log_debugx("parsing map \"%s\"", map);
1009 
1010 	if (map[0] == '-')
1011 		return (parse_special_map(parent, map, key));
1012 
1013 	if (map[0] == '/') {
1014 		path = checked_strdup(map);
1015 	} else {
1016 		ret = asprintf(&path, "%s/%s", AUTO_MAP_PREFIX, map);
1017 		if (ret < 0)
1018 			log_err(1, "asprintf");
1019 		log_debugx("map \"%s\" maps to \"%s\"", map, path);
1020 
1021 		/*
1022 		 * See if the file exists.  If not, try to obtain the map
1023 		 * from directory services.
1024 		 */
1025 		error = access(path, F_OK);
1026 		if (error != 0) {
1027 			log_debugx("map file \"%s\" does not exist; falling "
1028 			    "back to directory services", path);
1029 			return (parse_included_map(parent, map));
1030 		}
1031 	}
1032 
1033 	executable = file_is_executable(path);
1034 
1035 	if (executable) {
1036 		log_debugx("map \"%s\" is executable", map);
1037 
1038 		if (key != NULL) {
1039 			yyin = auto_popen(path, key, NULL);
1040 		} else {
1041 			yyin = auto_popen(path, NULL);
1042 		}
1043 		assert(yyin != NULL);
1044 	} else {
1045 		yyin = fopen(path, "r");
1046 		if (yyin == NULL)
1047 			log_err(1, "unable to open \"%s\"", path);
1048 	}
1049 
1050 	free(path);
1051 	path = NULL;
1052 
1053 	parse_map_yyin(parent, map, executable ? key : NULL);
1054 
1055 	if (executable) {
1056 		error = auto_pclose(yyin);
1057 		yyin = NULL;
1058 		if (error != 0) {
1059 			log_errx(1, "failed to handle executable map \"%s\"",
1060 			    map);
1061 		}
1062 	} else {
1063 		fclose(yyin);
1064 	}
1065 	yyin = NULL;
1066 
1067 	log_debugx("done parsing map \"%s\"", map);
1068 
1069 	node_expand_includes(parent, false);
1070 	node_expand_direct_maps(parent);
1071 }
1072 
1073 static void
1074 parse_master_yyin(struct node *root, const char *master)
1075 {
1076 	char *mountpoint = NULL, *map = NULL, *options = NULL;
1077 	int ret;
1078 
1079 	/*
1080 	 * XXX: 1 gives incorrect values; wtf?
1081 	 */
1082 	lineno = 0;
1083 
1084 	for (;;) {
1085 		ret = yylex();
1086 		if (ret == 0 || ret == NEWLINE) {
1087 			if (mountpoint != NULL) {
1088 				//log_debugx("adding map for %s", mountpoint);
1089 				node_new_map(root, mountpoint, options, map,
1090 				    master, lineno);
1091 			}
1092 			if (ret == 0) {
1093 				break;
1094 			} else {
1095 				mountpoint = map = options = NULL;
1096 				continue;
1097 			}
1098 		}
1099 		if (mountpoint == NULL) {
1100 			mountpoint = checked_strdup(yytext);
1101 		} else if (map == NULL) {
1102 			map = checked_strdup(yytext);
1103 		} else if (options == NULL) {
1104 			/*
1105 			 * +1 to skip leading "-".
1106 			 */
1107 			options = checked_strdup(yytext + 1);
1108 		} else {
1109 			log_errx(1, "too many arguments at %s, line %d",
1110 			    master, lineno);
1111 		}
1112 	}
1113 }
1114 
1115 void
1116 parse_master(struct node *root, const char *master)
1117 {
1118 
1119 	log_debugx("parsing auto_master file at \"%s\"", master);
1120 
1121 	yyin = fopen(master, "r");
1122 	if (yyin == NULL)
1123 		err(1, "unable to open %s", master);
1124 
1125 	parse_master_yyin(root, master);
1126 
1127 	fclose(yyin);
1128 	yyin = NULL;
1129 
1130 	log_debugx("done parsing \"%s\"", master);
1131 
1132 	node_expand_includes(root, true);
1133 	node_expand_direct_maps(root);
1134 }
1135 
1136 /*
1137  * Two things daemon(3) does, that we actually also want to do
1138  * when running in foreground, is closing the stdin and chdiring
1139  * to "/".  This is what we do here.
1140  */
1141 void
1142 lesser_daemon(void)
1143 {
1144 	int error, fd;
1145 
1146 	error = chdir("/");
1147 	if (error != 0)
1148 		log_warn("chdir");
1149 
1150 	fd = open(_PATH_DEVNULL, O_RDWR, 0);
1151 	if (fd < 0) {
1152 		log_warn("cannot open %s", _PATH_DEVNULL);
1153 		return;
1154 	}
1155 
1156 	error = dup2(fd, STDIN_FILENO);
1157 	if (error != 0)
1158 		log_warn("dup2");
1159 
1160 	error = close(fd);
1161 	if (error != 0) {
1162 		/* Bloody hell. */
1163 		log_warn("close");
1164 	}
1165 }
1166 
1167 int
1168 main(int argc, char **argv)
1169 {
1170 	char *cmdname;
1171 
1172 	if (argv[0] == NULL)
1173 		log_errx(1, "NULL command name");
1174 
1175 	cmdname = basename(argv[0]);
1176 
1177 	if (strcmp(cmdname, "automount") == 0)
1178 		return (main_automount(argc, argv));
1179 	else if (strcmp(cmdname, "automountd") == 0)
1180 		return (main_automountd(argc, argv));
1181 	else if (strcmp(cmdname, "autounmountd") == 0)
1182 		return (main_autounmountd(argc, argv));
1183 	else
1184 		log_errx(1, "binary name should be either \"automount\", "
1185 		    "\"automountd\", or \"autounmountd\"");
1186 }
1187