xref: /netbsd-src/common/lib/libprop/prop_object.c (revision ce2c90c7c172d95d2402a5b3d96d8f8e6d138a21)
1 /*	$NetBSD: prop_object.c,v 1.7 2006/10/12 04:41:51 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 2006 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Jason R. Thorpe.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *      This product includes software developed by the NetBSD
21  *      Foundation, Inc. and its contributors.
22  * 4. Neither the name of The NetBSD Foundation nor the names of its
23  *    contributors may be used to endorse or promote products derived
24  *    from this software without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
36  * POSSIBILITY OF SUCH DAMAGE.
37  */
38 
39 #include <prop/prop_object.h>
40 #include "prop_object_impl.h"
41 
42 #if !defined(_KERNEL) && !defined(_STANDALONE)
43 #include <sys/mman.h>
44 #include <sys/stat.h>
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <limits.h>
48 #include <unistd.h>
49 #endif
50 
51 #ifdef _STANDALONE
52 void *
53 _prop_standalone_calloc(size_t size)
54 {
55 	void *rv;
56 
57 	rv = alloc(size);
58 	if (rv != NULL)
59 		memset(rv, 0, size);
60 
61 	return (rv);
62 }
63 
64 void *
65 _prop_standalone_realloc(void *v, size_t size)
66 {
67 	void *rv;
68 
69 	rv = alloc(size);
70 	if (rv != NULL) {
71 		memcpy(rv, v, size);	/* XXX */
72 		dealloc(v, 0);		/* XXX */
73 	}
74 
75 	return (rv);
76 }
77 #endif /* _STANDALONE */
78 
79 /*
80  * _prop_object_init --
81  *	Initialize an object.  Called when sub-classes create
82  *	an instance.
83  */
84 void
85 _prop_object_init(struct _prop_object *po, const struct _prop_object_type *pot)
86 {
87 
88 	po->po_type = pot;
89 	po->po_refcnt = 1;
90 }
91 
92 /*
93  * _prop_object_fini --
94  *	Finalize an object.  Called when sub-classes destroy
95  *	an instance.
96  */
97 /*ARGSUSED*/
98 void
99 _prop_object_fini(struct _prop_object *po)
100 {
101 	/* Nothing to do, currently. */
102 	(void) po;
103 }
104 
105 /*
106  * _prop_object_externalize_start_tag --
107  *	Append an XML-style start tag to the externalize buffer.
108  */
109 boolean_t
110 _prop_object_externalize_start_tag(
111     struct _prop_object_externalize_context *ctx, const char *tag)
112 {
113 	unsigned int i;
114 
115 	for (i = 0; i < ctx->poec_depth; i++) {
116 		if (_prop_object_externalize_append_char(ctx, '\t') == FALSE)
117 			return (FALSE);
118 	}
119 	if (_prop_object_externalize_append_char(ctx, '<') == FALSE ||
120 	    _prop_object_externalize_append_cstring(ctx, tag) == FALSE ||
121 	    _prop_object_externalize_append_char(ctx, '>') == FALSE)
122 		return (FALSE);
123 
124 	return (TRUE);
125 }
126 
127 /*
128  * _prop_object_externalize_end_tag --
129  *	Append an XML-style end tag to the externalize buffer.
130  */
131 boolean_t
132 _prop_object_externalize_end_tag(
133     struct _prop_object_externalize_context *ctx, const char *tag)
134 {
135 
136 	if (_prop_object_externalize_append_char(ctx, '<') == FALSE ||
137 	    _prop_object_externalize_append_char(ctx, '/') == FALSE ||
138 	    _prop_object_externalize_append_cstring(ctx, tag) == FALSE ||
139 	    _prop_object_externalize_append_char(ctx, '>') == FALSE ||
140 	    _prop_object_externalize_append_char(ctx, '\n') == FALSE)
141 		return (FALSE);
142 
143 	return (TRUE);
144 }
145 
146 /*
147  * _prop_object_externalize_empty_tag --
148  *	Append an XML-style empty tag to the externalize buffer.
149  */
150 boolean_t
151 _prop_object_externalize_empty_tag(
152     struct _prop_object_externalize_context *ctx, const char *tag)
153 {
154 	unsigned int i;
155 
156 	for (i = 0; i < ctx->poec_depth; i++) {
157 		if (_prop_object_externalize_append_char(ctx, '\t') == FALSE)
158 			return (FALSE);
159 	}
160 
161 	if (_prop_object_externalize_append_char(ctx, '<') == FALSE ||
162 	    _prop_object_externalize_append_cstring(ctx, tag) == FALSE ||
163 	    _prop_object_externalize_append_char(ctx, '/') == FALSE ||
164 	    _prop_object_externalize_append_char(ctx, '>') == FALSE ||
165 	    _prop_object_externalize_append_char(ctx, '\n') == FALSE)
166 	    	return (FALSE);
167 
168 	return (TRUE);
169 }
170 
171 /*
172  * _prop_object_externalize_append_cstring --
173  *	Append a C string to the externalize buffer.
174  */
175 boolean_t
176 _prop_object_externalize_append_cstring(
177     struct _prop_object_externalize_context *ctx, const char *cp)
178 {
179 
180 	while (*cp != '\0') {
181 		if (_prop_object_externalize_append_char(ctx,
182 						(unsigned char) *cp) == FALSE)
183 			return (FALSE);
184 		cp++;
185 	}
186 
187 	return (TRUE);
188 }
189 
190 /*
191  * _prop_object_externalize_append_encoded_cstring --
192  *	Append an encoded C string to the externalize buffer.
193  */
194 boolean_t
195 _prop_object_externalize_append_encoded_cstring(
196     struct _prop_object_externalize_context *ctx, const char *cp)
197 {
198 
199 	while (*cp != '\0') {
200 		switch (*cp) {
201 		case '<':
202 			if (_prop_object_externalize_append_cstring(ctx,
203 					"&lt;") == FALSE)
204 				return (FALSE);
205 			break;
206 		case '>':
207 			if (_prop_object_externalize_append_cstring(ctx,
208 					"&gt;") == FALSE)
209 				return (FALSE);
210 			break;
211 		case '&':
212 			if (_prop_object_externalize_append_cstring(ctx,
213 					"&amp;") == FALSE)
214 				return (FALSE);
215 			break;
216 		default:
217 			if (_prop_object_externalize_append_char(ctx,
218 					(unsigned char) *cp) == FALSE)
219 				return (FALSE);
220 			break;
221 		}
222 		cp++;
223 	}
224 
225 	return (TRUE);
226 }
227 
228 #define	BUF_EXPAND		256
229 
230 /*
231  * _prop_object_externalize_append_char --
232  *	Append a single character to the externalize buffer.
233  */
234 boolean_t
235 _prop_object_externalize_append_char(
236     struct _prop_object_externalize_context *ctx, unsigned char c)
237 {
238 
239 	_PROP_ASSERT(ctx->poec_capacity != 0);
240 	_PROP_ASSERT(ctx->poec_buf != NULL);
241 	_PROP_ASSERT(ctx->poec_len <= ctx->poec_capacity);
242 
243 	if (ctx->poec_len == ctx->poec_capacity) {
244 		char *cp = _PROP_REALLOC(ctx->poec_buf,
245 					 ctx->poec_capacity + BUF_EXPAND,
246 					 M_TEMP);
247 		if (cp == NULL)
248 			return (FALSE);
249 		ctx->poec_capacity = ctx->poec_capacity + BUF_EXPAND;
250 		ctx->poec_buf = cp;
251 	}
252 
253 	ctx->poec_buf[ctx->poec_len++] = c;
254 
255 	return (TRUE);
256 }
257 
258 /*
259  * _prop_object_externalize_header --
260  *	Append the standard XML header to the externalize buffer.
261  */
262 boolean_t
263 _prop_object_externalize_header(struct _prop_object_externalize_context *ctx)
264 {
265 	static const char _plist_xml_header[] =
266 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n"
267 "<!DOCTYPE plist PUBLIC \"-//Apple Computer//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n";
268 
269 	if (_prop_object_externalize_append_cstring(ctx,
270 						 _plist_xml_header) == FALSE ||
271 	    _prop_object_externalize_start_tag(ctx,
272 				       "plist version=\"1.0\"") == FALSE ||
273 	    _prop_object_externalize_append_char(ctx, '\n') == FALSE)
274 		return (FALSE);
275 
276 	return (TRUE);
277 }
278 
279 /*
280  * _prop_object_externalize_footer --
281  *	Append the standard XML footer to the externalize buffer.  This
282  *	also NUL-terminates the buffer.
283  */
284 boolean_t
285 _prop_object_externalize_footer(struct _prop_object_externalize_context *ctx)
286 {
287 
288 	if (_prop_object_externalize_end_tag(ctx, "plist") == FALSE ||
289 	    _prop_object_externalize_append_char(ctx, '\0') == FALSE)
290 		return (FALSE);
291 
292 	return (TRUE);
293 }
294 
295 /*
296  * _prop_object_externalize_context_alloc --
297  *	Allocate an externalize context.
298  */
299 struct _prop_object_externalize_context *
300 _prop_object_externalize_context_alloc(void)
301 {
302 	struct _prop_object_externalize_context *ctx;
303 
304 	ctx = _PROP_MALLOC(sizeof(*ctx), M_TEMP);
305 	if (ctx != NULL) {
306 		ctx->poec_buf = _PROP_MALLOC(BUF_EXPAND, M_TEMP);
307 		if (ctx->poec_buf == NULL) {
308 			_PROP_FREE(ctx, M_TEMP);
309 			return (NULL);
310 		}
311 		ctx->poec_len = 0;
312 		ctx->poec_capacity = BUF_EXPAND;
313 		ctx->poec_depth = 0;
314 	}
315 	return (ctx);
316 }
317 
318 /*
319  * _prop_object_externalize_context_free --
320  *	Free an externalize context.
321  */
322 void
323 _prop_object_externalize_context_free(
324 		struct _prop_object_externalize_context *ctx)
325 {
326 
327 	/* Buffer is always freed by the caller. */
328 	_PROP_FREE(ctx, M_TEMP);
329 }
330 
331 /*
332  * _prop_object_internalize_skip_comment --
333  *	Skip the body and end tag of a comment.
334  */
335 static boolean_t
336 _prop_object_internalize_skip_comment(
337 				struct _prop_object_internalize_context *ctx)
338 {
339 	const char *cp = ctx->poic_cp;
340 
341 	while (!_PROP_EOF(*cp)) {
342 		if (cp[0] == '-' &&
343 		    cp[1] == '-' &&
344 		    cp[2] == '>') {
345 			ctx->poic_cp = cp + 3;
346 			return (TRUE);
347 		}
348 		cp++;
349 	}
350 
351 	return (FALSE);		/* ran out of buffer */
352 }
353 
354 /*
355  * _prop_object_internalize_find_tag --
356  *	Find the next tag in an XML stream.  Optionally compare the found
357  *	tag to an expected tag name.  State of the context is undefined
358  *	if this routine returns FALSE.  Upon success, the context points
359  *	to the first octet after the tag.
360  */
361 boolean_t
362 _prop_object_internalize_find_tag(struct _prop_object_internalize_context *ctx,
363 		      const char *tag, _prop_tag_type_t type)
364 {
365 	const char *cp;
366 	size_t taglen;
367 
368 	if (tag != NULL)
369 		taglen = strlen(tag);
370 	else
371 		taglen = 0;
372 
373  start_over:
374 	cp = ctx->poic_cp;
375 
376 	/*
377 	 * Find the start of the tag.
378 	 */
379 	while (_PROP_ISSPACE(*cp))
380 		cp++;
381 	if (_PROP_EOF(*cp))
382 		return (FALSE);
383 
384 	if (*cp != '<')
385 		return (FALSE);
386 
387 	ctx->poic_tag_start = cp++;
388 	if (_PROP_EOF(*cp))
389 		return (FALSE);
390 
391 	if (*cp == '!') {
392 		if (cp[1] != '-' || cp[2] != '-')
393 			return (FALSE);
394 		/*
395 		 * Comment block -- only allowed if we are allowed to
396 		 * return a start tag.
397 		 */
398 		if (type == _PROP_TAG_TYPE_END)
399 			return (FALSE);
400 		ctx->poic_cp = cp + 3;
401 		if (_prop_object_internalize_skip_comment(ctx) == FALSE)
402 			return (FALSE);
403 		goto start_over;
404 	}
405 
406 	if (*cp == '/') {
407 		if (type != _PROP_TAG_TYPE_END &&
408 		    type != _PROP_TAG_TYPE_EITHER)
409 			return (FALSE);
410 		cp++;
411 		if (_PROP_EOF(*cp))
412 			return (FALSE);
413 		ctx->poic_tag_type = _PROP_TAG_TYPE_END;
414 	} else {
415 		if (type != _PROP_TAG_TYPE_START &&
416 		    type != _PROP_TAG_TYPE_EITHER)
417 			return (FALSE);
418 		ctx->poic_tag_type = _PROP_TAG_TYPE_START;
419 	}
420 
421 	ctx->poic_tagname = cp;
422 
423 	while (!_PROP_ISSPACE(*cp) && *cp != '/' && *cp != '>')
424 		cp++;
425 	if (_PROP_EOF(*cp))
426 		return (FALSE);
427 
428 	ctx->poic_tagname_len = cp - ctx->poic_tagname;
429 
430 	/* Make sure this is the tag we're looking for. */
431 	if (tag != NULL &&
432 	    (taglen != ctx->poic_tagname_len ||
433 	     memcmp(tag, ctx->poic_tagname, taglen) != 0))
434 		return (FALSE);
435 
436 	/* Check for empty tag. */
437 	if (*cp == '/') {
438 		if (ctx->poic_tag_type != _PROP_TAG_TYPE_START)
439 			return(FALSE);		/* only valid on start tags */
440 		ctx->poic_is_empty_element = TRUE;
441 		cp++;
442 		if (_PROP_EOF(*cp) || *cp != '>')
443 			return (FALSE);
444 	} else
445 		ctx->poic_is_empty_element = FALSE;
446 
447 	/* Easy case of no arguments. */
448 	if (*cp == '>') {
449 		ctx->poic_tagattr = NULL;
450 		ctx->poic_tagattr_len = 0;
451 		ctx->poic_tagattrval = NULL;
452 		ctx->poic_tagattrval_len = 0;
453 		ctx->poic_cp = cp + 1;
454 		return (TRUE);
455 	}
456 
457 	_PROP_ASSERT(!_PROP_EOF(*cp));
458 	cp++;
459 	if (_PROP_EOF(*cp))
460 		return (FALSE);
461 
462 	while (_PROP_ISSPACE(*cp))
463 		cp++;
464 	if (_PROP_EOF(*cp))
465 		return (FALSE);
466 
467 	ctx->poic_tagattr = cp;
468 
469 	while (!_PROP_ISSPACE(*cp) && *cp != '=')
470 		cp++;
471 	if (_PROP_EOF(*cp))
472 		return (FALSE);
473 
474 	ctx->poic_tagattr_len = cp - ctx->poic_tagattr;
475 
476 	cp++;
477 	if (*cp != '\"')
478 		return (FALSE);
479 	cp++;
480 	if (_PROP_EOF(*cp))
481 		return (FALSE);
482 
483 	ctx->poic_tagattrval = cp;
484 	while (*cp != '\"')
485 		cp++;
486 	if (_PROP_EOF(*cp))
487 		return (FALSE);
488 	ctx->poic_tagattrval_len = cp - ctx->poic_tagattrval;
489 
490 	cp++;
491 	if (*cp != '>')
492 		return (FALSE);
493 
494 	ctx->poic_cp = cp + 1;
495 	return (TRUE);
496 }
497 
498 /*
499  * _prop_object_internalize_decode_string --
500  *	Decode an encoded string.
501  */
502 boolean_t
503 _prop_object_internalize_decode_string(
504 				struct _prop_object_internalize_context *ctx,
505 				char *target, size_t targsize, size_t *sizep,
506 				const char **cpp)
507 {
508 	const char *src;
509 	size_t tarindex;
510 	char c;
511 
512 	tarindex = 0;
513 	src = ctx->poic_cp;
514 
515 	for (;;) {
516 		if (_PROP_EOF(*src))
517 			return (FALSE);
518 		if (*src == '<') {
519 			break;
520 		}
521 
522 		if ((c = *src) == '&') {
523 			if (src[1] == 'a' &&
524 			    src[2] == 'm' &&
525 			    src[3] == 'p' &&
526 			    src[4] == ';') {
527 			    	c = '&';
528 				src += 5;
529 			} else if (src[1] == 'l' &&
530 				   src[2] == 't' &&
531 				   src[3] == ';') {
532 				c = '<';
533 				src += 4;
534 			} else if (src[1] == 'g' &&
535 				   src[2] == 't' &&
536 				   src[3] == ';') {
537 				c = '>';
538 				src += 4;
539 			} else if (src[1] == 'a' &&
540 				   src[2] == 'p' &&
541 				   src[3] == 'o' &&
542 				   src[4] == 's' &&
543 				   src[5] == ';') {
544 				c = '\'';
545 				src += 6;
546 			} else if (src[1] == 'q' &&
547 				   src[2] == 'u' &&
548 				   src[3] == 'o' &&
549 				   src[4] == 't' &&
550 				   src[5] == ';') {
551 				c = '\"';
552 				src += 6;
553 			} else
554 				return (FALSE);
555 		} else
556 			src++;
557 		if (target) {
558 			if (tarindex >= targsize)
559 				return (FALSE);
560 			target[tarindex] = c;
561 		}
562 		tarindex++;
563 	}
564 
565 	_PROP_ASSERT(*src == '<');
566 	if (sizep != NULL)
567 		*sizep = tarindex;
568 	if (cpp != NULL)
569 		*cpp = src;
570 
571 	return (TRUE);
572 }
573 
574 /*
575  * _prop_object_internalize_match --
576  *	Returns true if the two character streams match.
577  */
578 boolean_t
579 _prop_object_internalize_match(const char *str1, size_t len1,
580 			       const char *str2, size_t len2)
581 {
582 
583 	return (len1 == len2 && memcmp(str1, str2, len1) == 0);
584 }
585 
586 #define	INTERNALIZER(t, f)			\
587 {	t,	sizeof(t) - 1,		f	}
588 
589 static const struct _prop_object_internalizer {
590 	const char	*poi_tag;
591 	size_t		poi_taglen;
592 	prop_object_t	(*poi_intern)(
593 				struct _prop_object_internalize_context *);
594 } _prop_object_internalizer_table[] = {
595 	INTERNALIZER("array", _prop_array_internalize),
596 
597 	INTERNALIZER("true", _prop_bool_internalize),
598 	INTERNALIZER("false", _prop_bool_internalize),
599 
600 	INTERNALIZER("data", _prop_data_internalize),
601 
602 	INTERNALIZER("dict", _prop_dictionary_internalize),
603 
604 	INTERNALIZER("integer", _prop_number_internalize),
605 
606 	INTERNALIZER("string", _prop_string_internalize),
607 
608 	{ 0, 0, NULL }
609 };
610 
611 #undef INTERNALIZER
612 
613 /*
614  * _prop_object_internalize_by_tag --
615  *	Determine the object type from the tag in the context and
616  *	internalize it.
617  */
618 prop_object_t
619 _prop_object_internalize_by_tag(struct _prop_object_internalize_context *ctx)
620 {
621 	const struct _prop_object_internalizer *poi;
622 
623 	for (poi = _prop_object_internalizer_table;
624 	     poi->poi_tag != NULL; poi++) {
625 		if (_prop_object_internalize_match(ctx->poic_tagname,
626 						   ctx->poic_tagname_len,
627 						   poi->poi_tag,
628 						   poi->poi_taglen))
629 			return ((*poi->poi_intern)(ctx));
630 	}
631 
632 	return (NULL);
633 }
634 
635 /*
636  * _prop_object_internalize_context_alloc --
637  *	Allocate an internalize context.
638  */
639 struct _prop_object_internalize_context *
640 _prop_object_internalize_context_alloc(const char *xml)
641 {
642 	struct _prop_object_internalize_context *ctx;
643 
644 	ctx = _PROP_MALLOC(sizeof(struct _prop_object_internalize_context),
645 			   M_TEMP);
646 	if (ctx == NULL)
647 		return (NULL);
648 
649 	ctx->poic_xml = ctx->poic_cp = xml;
650 
651 	/*
652 	 * Skip any whitespace and XML preamble stuff that we don't
653 	 * know about / care about.
654 	 */
655 	for (;;) {
656 		while (_PROP_ISSPACE(*xml))
657 			xml++;
658 		if (_PROP_EOF(*xml) || *xml != '<')
659 			goto bad;
660 
661 #define	MATCH(str)	(memcmp(&xml[1], str, sizeof(str) - 1) == 0)
662 
663 		/*
664 		 * Skip over the XML preamble that Apple XML property
665 		 * lists usually include at the top of the file.
666 		 */
667 		if (MATCH("?xml ") ||
668 		    MATCH("!DOCTYPE plist")) {
669 			while (*xml != '>' && !_PROP_EOF(*xml))
670 				xml++;
671 			if (_PROP_EOF(*xml))
672 				goto bad;
673 			xml++;	/* advance past the '>' */
674 			continue;
675 		}
676 
677 		if (MATCH("<!--")) {
678 			ctx->poic_cp = xml + 4;
679 			if (_prop_object_internalize_skip_comment(ctx) == FALSE)
680 				goto bad;
681 			xml = ctx->poic_cp;
682 			continue;
683 		}
684 
685 #undef MATCH
686 
687 		/*
688 		 * We don't think we should skip it, so let's hope we can
689 		 * parse it.
690 		 */
691 		break;
692 	}
693 
694 	ctx->poic_cp = xml;
695 	return (ctx);
696  bad:
697 	_PROP_FREE(ctx, M_TEMP);
698 	return (NULL);
699 }
700 
701 /*
702  * _prop_object_internalize_context_free --
703  *	Free an internalize context.
704  */
705 void
706 _prop_object_internalize_context_free(
707 		struct _prop_object_internalize_context *ctx)
708 {
709 
710 	_PROP_FREE(ctx, M_TEMP);
711 }
712 
713 #if !defined(_KERNEL) && !defined(_STANDALONE)
714 /*
715  * _prop_object_externalize_file_dirname --
716  *	dirname(3), basically.  We have to roll our own because the
717  *	system dirname(3) isn't reentrant.
718  */
719 static void
720 _prop_object_externalize_file_dirname(const char *path, char *result)
721 {
722 	const char *lastp;
723 	size_t len;
724 
725 	/*
726 	 * If `path' is a NULL pointer or points to an empty string,
727 	 * return ".".
728 	 */
729 	if (path == NULL || *path == '\0')
730 		goto singledot;
731 
732 	/* String trailing slashes, if any. */
733 	lastp = path + strlen(path) - 1;
734 	while (lastp != path && *lastp == '/')
735 		lastp--;
736 
737 	/* Terminate path at the last occurrence of '/'. */
738 	do {
739 		if (*lastp == '/') {
740 			/* Strip trailing slashes, if any. */
741 			while (lastp != path && *lastp == '/')
742 				lastp--;
743 
744 			/* ...and copy the result into the result buffer. */
745 			len = (lastp - path) + 1 /* last char */;
746 			if (len > (PATH_MAX - 1))
747 				len = PATH_MAX - 1;
748 
749 			memcpy(result, path, len);
750 			result[len] = '\0';
751 			return;
752 		}
753 	} while (--lastp >= path);
754 
755  	/* No /'s found, return ".". */
756  singledot:
757 	strcpy(result, ".");
758 }
759 
760 /*
761  * _prop_object_externalize_write_file --
762  *	Write an externalized dictionary to the specified file.
763  *	The file is written atomically from the caller's perspective,
764  *	and the mode set to 0666 modified by the caller's umask.
765  */
766 boolean_t
767 _prop_object_externalize_write_file(const char *fname, const char *xml,
768     size_t len)
769 {
770 	char tname[PATH_MAX];
771 	int fd;
772 	int save_errno;
773 
774 	if (len > SSIZE_MAX) {
775 		errno = EFBIG;
776 		return (FALSE);
777 	}
778 
779 	/*
780 	 * Get the directory name where the file is to be written
781 	 * and create the temporary file.
782 	 *
783 	 * We don't use mkstemp() because mkstemp() always creates the
784 	 * file with mode 0600.  We do, however, use mktemp() safely.
785 	 */
786  again:
787 	_prop_object_externalize_file_dirname(fname, tname);
788 	if (strlcat(tname, "/.plistXXXXXX", sizeof(tname)) >= sizeof(tname)) {
789 		errno = ENAMETOOLONG;
790 		return (FALSE);
791 	}
792 	if (mktemp(tname) == NULL)
793 		return (FALSE);
794 	if ((fd = open(tname, O_CREAT|O_RDWR|O_EXCL, 0666)) == -1) {
795 		if (errno == EEXIST)
796 			goto again;
797 		return (FALSE);
798 	}
799 
800 	if (write(fd, xml, len) != (ssize_t)len)
801 		goto bad;
802 
803 	if (fsync(fd) == -1)
804 		goto bad;
805 
806 	(void) close(fd);
807 	fd = -1;
808 
809 	if (rename(tname, fname) == -1)
810 		goto bad;
811 
812 	return (TRUE);
813 
814  bad:
815 	save_errno = errno;
816 	if (fd != -1)
817 		(void) close(fd);
818 	(void) unlink(tname);
819 	errno = save_errno;
820 	return (FALSE);
821 }
822 
823 /*
824  * _prop_object_internalize_map_file --
825  *	Map a file for the purpose of internalizing it.
826  */
827 struct _prop_object_internalize_mapped_file *
828 _prop_object_internalize_map_file(const char *fname)
829 {
830 	struct stat sb;
831 	struct _prop_object_internalize_mapped_file *mf;
832 	size_t pgsize = sysconf(_SC_PAGESIZE);
833 	size_t pgmask = pgsize - 1;
834 	boolean_t need_guard = FALSE;
835 	int fd;
836 
837 	mf = _PROP_MALLOC(sizeof(*mf), M_TEMP);
838 	if (mf == NULL)
839 		return (NULL);
840 
841 	fd = open(fname, O_RDONLY, 0400);
842 	if (fd == -1) {
843 		_PROP_FREE(mf, M_TEMP);
844 		return (NULL);
845 	}
846 
847 	if (fstat(fd, &sb) == -1) {
848 		(void) close(fd);
849 		_PROP_FREE(mf, M_TEMP);
850 		return (NULL);
851 	}
852 	mf->poimf_mapsize = ((size_t)sb.st_size + pgmask) & ~pgmask;
853 	if (mf->poimf_mapsize < sb.st_size) {
854 		(void) close(fd);
855 		_PROP_FREE(mf, M_TEMP);
856 		return (NULL);
857 	}
858 
859 	/*
860 	 * If the file length is an integral number of pages, then we
861 	 * need to map a guard page at the end in order to provide the
862 	 * necessary NUL-termination of the buffer.
863 	 */
864 	if ((sb.st_size & pgmask) == 0)
865 		need_guard = TRUE;
866 
867 	mf->poimf_xml = mmap(NULL, need_guard ? mf->poimf_mapsize + pgsize
868 			    		      : mf->poimf_mapsize,
869 			    PROT_READ, MAP_FILE|MAP_SHARED, fd, (off_t)0);
870 	(void) close(fd);
871 	if (mf->poimf_xml == MAP_FAILED) {
872 		_PROP_FREE(mf, M_TEMP);
873 		return (NULL);
874 	}
875 	(void) madvise(mf->poimf_xml, mf->poimf_mapsize, MADV_SEQUENTIAL);
876 
877 	if (need_guard) {
878 		if (mmap(mf->poimf_xml + mf->poimf_mapsize,
879 			 pgsize, PROT_READ,
880 			 MAP_ANON|MAP_PRIVATE|MAP_FIXED, -1,
881 			 (off_t)0) == MAP_FAILED) {
882 			(void) munmap(mf->poimf_xml, mf->poimf_mapsize);
883 			_PROP_FREE(mf, M_TEMP);
884 			return (NULL);
885 		}
886 		mf->poimf_mapsize += pgsize;
887 	}
888 
889 	return (mf);
890 }
891 
892 /*
893  * _prop_object_internalize_unmap_file --
894  *	Unmap a file previously mapped for internalizing.
895  */
896 void
897 _prop_object_internalize_unmap_file(
898     struct _prop_object_internalize_mapped_file *mf)
899 {
900 
901 	(void) madvise(mf->poimf_xml, mf->poimf_mapsize, MADV_DONTNEED);
902 	(void) munmap(mf->poimf_xml, mf->poimf_mapsize);
903 	_PROP_FREE(mf, M_TEMP);
904 }
905 #endif /* !_KERNEL && !_STANDALONE */
906 
907 /*
908  * Retain / release serialization --
909  *
910  * Eventually we would like to use atomic operations.  But until we have
911  * an MI API for them that is common to userland and the kernel, we will
912  * use a lock instead.
913  *
914  * We use a single global mutex for all serialization.  In the kernel, because
915  * we are still under a biglock, this will basically never contend (properties
916  * cannot be manipulated at interrupt level).  In userland, this will cost
917  * nothing for single-threaded programs.  For multi-threaded programs, there
918  * could be contention, but it probably won't cost that much unless the program
919  * makes heavy use of property lists.
920  */
921 _PROP_MUTEX_DECL_STATIC(_prop_refcnt_mutex)
922 #define	_PROP_REFCNT_LOCK()	_PROP_MUTEX_LOCK(_prop_refcnt_mutex)
923 #define	_PROP_REFCNT_UNLOCK()	_PROP_MUTEX_UNLOCK(_prop_refcnt_mutex)
924 
925 /*
926  * prop_object_retain --
927  *	Increment the reference count on an object.
928  */
929 void
930 prop_object_retain(prop_object_t obj)
931 {
932 	struct _prop_object *po = obj;
933 	uint32_t ocnt;
934 
935 	_PROP_REFCNT_LOCK();
936 	ocnt = po->po_refcnt++;
937 	_PROP_REFCNT_UNLOCK();
938 
939 	_PROP_ASSERT(ocnt != 0xffffffffU);
940 }
941 
942 /*
943  * prop_object_release --
944  *	Decrement the reference count on an object.
945  *
946  *	Free the object if we are releasing the final
947  *	reference.
948  */
949 void
950 prop_object_release(prop_object_t obj)
951 {
952 	struct _prop_object *po = obj;
953 	uint32_t ocnt;
954 
955 	_PROP_REFCNT_LOCK();
956 	ocnt = po->po_refcnt--;
957 	_PROP_REFCNT_UNLOCK();
958 
959 	_PROP_ASSERT(ocnt != 0);
960 	if (ocnt == 1)
961 		(*po->po_type->pot_free)(po);
962 }
963 
964 /*
965  * prop_object_type --
966  *	Return the type of an object.
967  */
968 prop_type_t
969 prop_object_type(prop_object_t obj)
970 {
971 	struct _prop_object *po = obj;
972 
973 	if (obj == NULL)
974 		return (PROP_TYPE_UNKNOWN);
975 
976 	return (po->po_type->pot_type);
977 }
978 
979 /*
980  * prop_object_equals --
981  *	Returns TRUE if thw two objects are equivalent.
982  */
983 boolean_t
984 prop_object_equals(prop_object_t obj1, prop_object_t obj2)
985 {
986 	struct _prop_object *po1 = obj1;
987 	struct _prop_object *po2 = obj2;
988 
989 	if (po1->po_type != po2->po_type)
990 		return (FALSE);
991 
992 	return ((*po1->po_type->pot_equals)(obj1, obj2));
993 }
994 
995 /*
996  * prop_object_iterator_next --
997  *	Return the next item during an iteration.
998  */
999 prop_object_t
1000 prop_object_iterator_next(prop_object_iterator_t pi)
1001 {
1002 
1003 	return ((*pi->pi_next_object)(pi));
1004 }
1005 
1006 /*
1007  * prop_object_iterator_reset --
1008  *	Reset the iterator to the first object so as to restart
1009  *	iteration.
1010  */
1011 void
1012 prop_object_iterator_reset(prop_object_iterator_t pi)
1013 {
1014 
1015 	(*pi->pi_reset)(pi);
1016 }
1017 
1018 /*
1019  * prop_object_iterator_release --
1020  *	Release the object iterator.
1021  */
1022 void
1023 prop_object_iterator_release(prop_object_iterator_t pi)
1024 {
1025 
1026 	prop_object_release(pi->pi_obj);
1027 	_PROP_FREE(pi, M_TEMP);
1028 }
1029