xref: /dragonfly/sys/libprop/prop_object.c (revision 8f706258d81394752df150b362d9dacacbdc8efa)
1 /*        $NetBSD: prop_object.c,v 1.26 2009/03/30 07:42:51 haad Exp $          */
2 
3 /*-
4  * Copyright (c) 2006, 2007 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  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 #include <libprop/prop_object.h>
33 #include "prop_object_impl.h"
34 
35 #if !defined(_KERNEL) && !defined(_STANDALONE)
36 #include <sys/mman.h>
37 #include <sys/stat.h>
38 #include <errno.h>
39 #include <fcntl.h>
40 #include <limits.h>
41 #include <unistd.h>
42 #endif
43 
44 /* XXX: netbsd's _nv stuff effectively does addfetch, not fetchadd */
45 #define atomic_inc_32_nv(x)   (atomic_fetchadd_int(x, 1)+1)
46 #define atomic_dec_32_nv(x)   (atomic_fetchadd_int(x, -1)-1)
47 #define atomic_inc_32(x)      atomic_add_int(x, 1)
48 #define atomic_dec_32(x)      atomic_add_int(x, 1)
49 
50 #include <machine/atomic.h>
51 
52 #ifdef _STANDALONE
53 void *
_prop_standalone_calloc(size_t size)54 _prop_standalone_calloc(size_t size)
55 {
56           void *rv;
57 
58           rv = alloc(size);
59           if (rv != NULL)
60                     memset(rv, 0, size);
61 
62           return (rv);
63 }
64 
65 void *
_prop_standalone_realloc(void * v,size_t size)66 _prop_standalone_realloc(void *v, size_t size)
67 {
68           void *rv;
69 
70           rv = alloc(size);
71           if (rv != NULL) {
72                     memcpy(rv, v, size);          /* XXX */
73                     dealloc(v, 0);                /* XXX */
74           }
75 
76           return (rv);
77 }
78 #endif /* _STANDALONE */
79 
80 /*
81  * _prop_object_init --
82  *        Initialize an object.  Called when sub-classes create
83  *        an instance.
84  */
85 void
_prop_object_init(struct _prop_object * po,const struct _prop_object_type * pot)86 _prop_object_init(struct _prop_object *po, const struct _prop_object_type *pot)
87 {
88 
89           po->po_type = pot;
90           po->po_refcnt = 1;
91 }
92 
93 /*
94  * _prop_object_fini --
95  *        Finalize an object.  Called when sub-classes destroy
96  *        an instance.
97  */
98 /*ARGSUSED*/
99 void
_prop_object_fini(struct _prop_object * po _PROP_ARG_UNUSED)100 _prop_object_fini(struct _prop_object *po _PROP_ARG_UNUSED)
101 {
102           /* Nothing to do, currently. */
103 }
104 
105 /*
106  * _prop_object_externalize_start_tag --
107  *        Append an XML-style start tag to the externalize buffer.
108  */
109 bool
_prop_object_externalize_start_tag(struct _prop_object_externalize_context * ctx,const char * tag)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 bool
_prop_object_externalize_end_tag(struct _prop_object_externalize_context * ctx,const char * tag)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 bool
_prop_object_externalize_empty_tag(struct _prop_object_externalize_context * ctx,const char * tag)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 bool
_prop_object_externalize_append_cstring(struct _prop_object_externalize_context * ctx,const char * cp)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 bool
_prop_object_externalize_append_encoded_cstring(struct _prop_object_externalize_context * ctx,const char * cp)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 bool
_prop_object_externalize_append_char(struct _prop_object_externalize_context * ctx,unsigned char c)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 bool
_prop_object_externalize_header(struct _prop_object_externalize_context * ctx)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 bool
_prop_object_externalize_footer(struct _prop_object_externalize_context * ctx)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 *
_prop_object_externalize_context_alloc(void)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
_prop_object_externalize_context_free(struct _prop_object_externalize_context * ctx)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 bool
_prop_object_internalize_skip_comment(struct _prop_object_internalize_context * ctx)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 bool
_prop_object_internalize_find_tag(struct _prop_object_internalize_context * ctx,const char * tag,_prop_tag_type_t type)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 bool
_prop_object_internalize_decode_string(struct _prop_object_internalize_context * ctx,char * target,size_t targsize,size_t * sizep,const char ** cpp)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 bool
_prop_object_internalize_match(const char * str1,size_t len1,const char * str2,size_t len2)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_internalizer_t    poi_intern;
593 } _prop_object_internalizer_table[] = {
594           INTERNALIZER("array", _prop_array_internalize),
595 
596           INTERNALIZER("true", _prop_bool_internalize),
597           INTERNALIZER("false", _prop_bool_internalize),
598 
599           INTERNALIZER("data", _prop_data_internalize),
600 
601           INTERNALIZER("dict", _prop_dictionary_internalize),
602 
603           INTERNALIZER("integer", _prop_number_internalize),
604 
605           INTERNALIZER("string", _prop_string_internalize),
606 
607           { 0, 0, NULL }
608 };
609 
610 #undef INTERNALIZER
611 
612 /*
613  * _prop_object_internalize_by_tag --
614  *        Determine the object type from the tag in the context and
615  *        internalize it.
616  */
617 prop_object_t
_prop_object_internalize_by_tag(struct _prop_object_internalize_context * ctx)618 _prop_object_internalize_by_tag(struct _prop_object_internalize_context *ctx)
619 {
620           const struct _prop_object_internalizer *poi;
621           prop_object_t obj, parent_obj;
622           void *data, *iter;
623           prop_object_internalizer_continue_t iter_func;
624           struct _prop_stack stack;
625 
626           _prop_stack_init(&stack);
627 
628 match_start:
629           for (poi = _prop_object_internalizer_table;
630                poi->poi_tag != NULL; poi++) {
631                     if (_prop_object_internalize_match(ctx->poic_tagname,
632                                                                ctx->poic_tagname_len,
633                                                                poi->poi_tag,
634                                                                poi->poi_taglen))
635                               break;
636           }
637           if ((poi == NULL) || (poi->poi_tag == NULL)) {
638                     while (_prop_stack_pop(&stack, &obj, &iter, &data, NULL)) {
639                               iter_func = (prop_object_internalizer_continue_t)iter;
640                               (*iter_func)(&stack, &obj, ctx, data, NULL);
641                     }
642 
643                     return (NULL);
644           }
645 
646           obj = NULL;
647           if (!(*poi->poi_intern)(&stack, &obj, ctx))
648                     goto match_start;
649 
650           parent_obj = obj;
651           while (_prop_stack_pop(&stack, &parent_obj, &iter, &data, NULL)) {
652                     iter_func = (prop_object_internalizer_continue_t)iter;
653                     if (!(*iter_func)(&stack, &parent_obj, ctx, data, obj))
654                               goto match_start;
655                     obj = parent_obj;
656           }
657 
658           return (parent_obj);
659 }
660 
661 prop_object_t
_prop_generic_internalize(const char * xml,const char * master_tag)662 _prop_generic_internalize(const char *xml, const char *master_tag)
663 {
664           prop_object_t obj = NULL;
665           struct _prop_object_internalize_context *ctx;
666 
667           ctx = _prop_object_internalize_context_alloc(xml);
668           if (ctx == NULL)
669                     return (NULL);
670 
671           /* We start with a <plist> tag. */
672           if (_prop_object_internalize_find_tag(ctx, "plist",
673                                                         _PROP_TAG_TYPE_START) == false)
674                     goto out;
675 
676           /* Plist elements cannot be empty. */
677           if (ctx->poic_is_empty_element)
678                     goto out;
679 
680           /*
681            * We don't understand any plist attributes, but Apple XML
682            * property lists often have a "version" attribute.  If we
683            * see that one, we simply ignore it.
684            */
685           if (ctx->poic_tagattr != NULL &&
686               !_PROP_TAGATTR_MATCH(ctx, "version"))
687                     goto out;
688 
689           /* Next we expect to see opening master_tag. */
690           if (_prop_object_internalize_find_tag(ctx, master_tag,
691                                                         _PROP_TAG_TYPE_START) == false)
692                     goto out;
693 
694           obj = _prop_object_internalize_by_tag(ctx);
695           if (obj == NULL)
696                     goto out;
697 
698           /*
699            * We've advanced past the closing master_tag.
700            * Now we want </plist>.
701            */
702           if (_prop_object_internalize_find_tag(ctx, "plist",
703                                                         _PROP_TAG_TYPE_END) == false) {
704                     prop_object_release(obj);
705                     obj = NULL;
706           }
707 
708  out:
709           _prop_object_internalize_context_free(ctx);
710           return (obj);
711 }
712 
713 /*
714  * _prop_object_internalize_context_alloc --
715  *        Allocate an internalize context.
716  */
717 struct _prop_object_internalize_context *
_prop_object_internalize_context_alloc(const char * xml)718 _prop_object_internalize_context_alloc(const char *xml)
719 {
720           struct _prop_object_internalize_context *ctx;
721 
722           ctx = _PROP_MALLOC(sizeof(struct _prop_object_internalize_context),
723                                  M_TEMP);
724           if (ctx == NULL)
725                     return (NULL);
726 
727           ctx->poic_xml = ctx->poic_cp = xml;
728 
729           /*
730            * Skip any whitespace and XML preamble stuff that we don't
731            * know about / care about.
732            */
733           for (;;) {
734                     while (_PROP_ISSPACE(*xml))
735                               xml++;
736                     if (_PROP_EOF(*xml) || *xml != '<')
737                               goto bad;
738 
739 #define   MATCH(str)          (memcmp(&xml[1], str, sizeof(str) - 1) == 0)
740 
741                     /*
742                      * Skip over the XML preamble that Apple XML property
743                      * lists usually include at the top of the file.
744                      */
745                     if (MATCH("?xml ") ||
746                         MATCH("!DOCTYPE plist")) {
747                               while (*xml != '>' && !_PROP_EOF(*xml))
748                                         xml++;
749                               if (_PROP_EOF(*xml))
750                                         goto bad;
751                               xml++;    /* advance past the '>' */
752                               continue;
753                     }
754 
755                     if (MATCH("<!--")) {
756                               ctx->poic_cp = xml + 4;
757                               if (_prop_object_internalize_skip_comment(ctx) == false)
758                                         goto bad;
759                               xml = ctx->poic_cp;
760                               continue;
761                     }
762 
763 #undef MATCH
764 
765                     /*
766                      * We don't think we should skip it, so let's hope we can
767                      * parse it.
768                      */
769                     break;
770           }
771 
772           ctx->poic_cp = xml;
773           return (ctx);
774  bad:
775           _PROP_FREE(ctx, M_TEMP);
776           return (NULL);
777 }
778 
779 /*
780  * _prop_object_internalize_context_free --
781  *        Free an internalize context.
782  */
783 void
_prop_object_internalize_context_free(struct _prop_object_internalize_context * ctx)784 _prop_object_internalize_context_free(
785                     struct _prop_object_internalize_context *ctx)
786 {
787 
788           _PROP_FREE(ctx, M_TEMP);
789 }
790 
791 #if !defined(_KERNEL) && !defined(_STANDALONE)
792 /*
793  * _prop_object_externalize_file_dirname --
794  *        dirname(3), basically.  We have to roll our own because the
795  *        system dirname(3) isn't reentrant.
796  */
797 static void
_prop_object_externalize_file_dirname(const char * path,char * result)798 _prop_object_externalize_file_dirname(const char *path, char *result)
799 {
800           const char *lastp;
801           size_t len;
802 
803           /*
804            * If `path' is a NULL pointer or points to an empty string,
805            * return ".".
806            */
807           if (path == NULL || *path == '\0')
808                     goto singledot;
809 
810           /* String trailing slashes, if any. */
811           lastp = path + strlen(path) - 1;
812           while (lastp != path && *lastp == '/')
813                     lastp--;
814 
815           /* Terminate path at the last occurrence of '/'. */
816           do {
817                     if (*lastp == '/') {
818                               /* Strip trailing slashes, if any. */
819                               while (lastp != path && *lastp == '/')
820                                         lastp--;
821 
822                               /* ...and copy the result into the result buffer. */
823                               len = (lastp - path) + 1 /* last char */;
824                               if (len > (PATH_MAX - 1))
825                                         len = PATH_MAX - 1;
826 
827                               memcpy(result, path, len);
828                               result[len] = '\0';
829                               return;
830                     }
831           } while (--lastp >= path);
832 
833           /* No /'s found, return ".". */
834  singledot:
835           strcpy(result, ".");
836 }
837 
838 /*
839  * _prop_object_externalize_write_file --
840  *        Write an externalized dictionary to the specified file.
841  *        The file is written atomically from the caller's perspective,
842  *        and the mode set to 0666 modified by the caller's umask.
843  */
844 bool
_prop_object_externalize_write_file(const char * fname,const char * xml,size_t len)845 _prop_object_externalize_write_file(const char *fname, const char *xml,
846     size_t len)
847 {
848           char tname[PATH_MAX];
849           int fd;
850           int save_errno;
851           mode_t myumask;
852 
853           if (len > SSIZE_MAX) {
854                     errno = EFBIG;
855                     return (false);
856           }
857 
858           /*
859            * Get the directory name where the file is to be written
860            * and create the temporary file.
861            */
862           _prop_object_externalize_file_dirname(fname, tname);
863           if (strlcat(tname, "/.plistXXXXXX", sizeof(tname)) >= sizeof(tname)) {
864                     errno = ENAMETOOLONG;
865                     return (false);
866           }
867           if ((fd = mkstemp(tname)) == -1)
868                     return (false);
869 
870           if (write(fd, xml, len) != (ssize_t)len)
871                     goto bad;
872 
873           if (fsync(fd) == -1)
874                     goto bad;
875 
876           myumask = umask(0);
877           (void)umask(myumask);
878           if (fchmod(fd, 0666 & ~myumask) == -1)
879                     goto bad;
880 
881           (void) close(fd);
882           fd = -1;
883 
884           if (rename(tname, fname) == -1)
885                     goto bad;
886 
887           return (true);
888 
889  bad:
890           save_errno = errno;
891           if (fd != -1)
892                     (void) close(fd);
893           (void) unlink(tname);
894           errno = save_errno;
895           return (false);
896 }
897 
898 /*
899  * _prop_object_internalize_map_file --
900  *        Map a file for the purpose of internalizing it.
901  */
902 struct _prop_object_internalize_mapped_file *
_prop_object_internalize_map_file(const char * fname)903 _prop_object_internalize_map_file(const char *fname)
904 {
905           struct stat sb;
906           struct _prop_object_internalize_mapped_file *mf;
907           size_t pgsize = (size_t)sysconf(_SC_PAGESIZE);
908           size_t pgmask = pgsize - 1;
909           bool need_guard = false;
910           int fd;
911 
912           mf = _PROP_MALLOC(sizeof(*mf), M_TEMP);
913           if (mf == NULL)
914                     return (NULL);
915 
916           fd = open(fname, O_RDONLY, 0400);
917           if (fd == -1) {
918                     _PROP_FREE(mf, M_TEMP);
919                     return (NULL);
920           }
921 
922           if (fstat(fd, &sb) == -1) {
923                     (void) close(fd);
924                     _PROP_FREE(mf, M_TEMP);
925                     return (NULL);
926           }
927           mf->poimf_mapsize = ((size_t)sb.st_size + pgmask) & ~pgmask;
928           if (mf->poimf_mapsize < (size_t)sb.st_size) {
929                     (void) close(fd);
930                     _PROP_FREE(mf, M_TEMP);
931                     return (NULL);
932           }
933 
934           /*
935            * If the file length is an integral number of pages, then we
936            * need to map a guard page at the end in order to provide the
937            * necessary NUL-termination of the buffer.
938            */
939           if ((sb.st_size & pgmask) == 0)
940                     need_guard = true;
941 
942           mf->poimf_xml = mmap(NULL, need_guard ? mf->poimf_mapsize + pgsize
943                                                         : mf->poimf_mapsize,
944                                   PROT_READ, MAP_FILE|MAP_SHARED, fd, (off_t)0);
945           (void) close(fd);
946           if (mf->poimf_xml == MAP_FAILED) {
947                     _PROP_FREE(mf, M_TEMP);
948                     return (NULL);
949           }
950           (void) madvise(mf->poimf_xml, mf->poimf_mapsize, MADV_SEQUENTIAL);
951 
952           if (need_guard) {
953                     if (mmap(mf->poimf_xml + mf->poimf_mapsize,
954                                pgsize, PROT_READ,
955                                MAP_ANON|MAP_PRIVATE|MAP_FIXED, -1,
956                                (off_t)0) == MAP_FAILED) {
957                               (void) munmap(mf->poimf_xml, mf->poimf_mapsize);
958                               _PROP_FREE(mf, M_TEMP);
959                               return (NULL);
960                     }
961                     mf->poimf_mapsize += pgsize;
962           }
963 
964           return (mf);
965 }
966 
967 /*
968  * _prop_object_internalize_unmap_file --
969  *        Unmap a file previously mapped for internalizing.
970  */
971 void
_prop_object_internalize_unmap_file(struct _prop_object_internalize_mapped_file * mf)972 _prop_object_internalize_unmap_file(
973     struct _prop_object_internalize_mapped_file *mf)
974 {
975 
976           (void) madvise(mf->poimf_xml, mf->poimf_mapsize, MADV_DONTNEED);
977           (void) munmap(mf->poimf_xml, mf->poimf_mapsize);
978           _PROP_FREE(mf, M_TEMP);
979 }
980 #endif /* !_KERNEL && !_STANDALONE */
981 
982 /*
983  * prop_object_retain --
984  *        Increment the reference count on an object.
985  */
986 void
prop_object_retain(prop_object_t obj)987 prop_object_retain(prop_object_t obj)
988 {
989           struct _prop_object *po = obj;
990           uint32_t ncnt;
991 
992           ncnt = atomic_inc_32_nv(&po->po_refcnt);
993           _PROP_ASSERT(ncnt != 0);
994 }
995 
996 /*
997  * prop_object_release_emergency
998  *        A direct free with prop_object_release failed.
999  *        Walk down the tree until a leaf is found and
1000  *        free that. Do not recurse to avoid stack overflows.
1001  *
1002  *        This is a slow edge condition, but necessary to
1003  *        guarantee that an object can always be freed.
1004  */
1005 static void
prop_object_release_emergency(prop_object_t obj)1006 prop_object_release_emergency(prop_object_t obj)
1007 {
1008           struct _prop_object *po;
1009           void (*unlock)(void);
1010           prop_object_t parent = NULL;
1011           uint32_t ocnt;
1012 
1013           for (;;) {
1014                     po = obj;
1015                     _PROP_ASSERT(obj);
1016 
1017                     if (po->po_type->pot_lock != NULL)
1018                               po->po_type->pot_lock();
1019 
1020                     /* Save pointerto unlock function */
1021                     unlock = po->po_type->pot_unlock;
1022 
1023                     /* Dance a bit to make sure we always get the non-racy ocnt */
1024                     ocnt = atomic_dec_32_nv(&po->po_refcnt);
1025                     ocnt++;
1026                     _PROP_ASSERT(ocnt != 0);
1027 
1028                     if (ocnt != 1) {
1029                               if (unlock != NULL)
1030                                         unlock();
1031                               break;
1032                     }
1033 
1034                     _PROP_ASSERT(po->po_type);
1035                     if ((po->po_type->pot_free)(NULL, &obj) ==
1036                         _PROP_OBJECT_FREE_DONE) {
1037                               if (unlock != NULL)
1038                                         unlock();
1039                               break;
1040                     }
1041 
1042                     if (unlock != NULL)
1043                               unlock();
1044 
1045                     parent = po;
1046                     atomic_inc_32(&po->po_refcnt);
1047           }
1048           _PROP_ASSERT(parent);
1049           /* One object was just freed. */
1050           po = parent;
1051           (*po->po_type->pot_emergency_free)(parent);
1052 }
1053 
1054 /*
1055  * prop_object_release --
1056  *        Decrement the reference count on an object.
1057  *
1058  *        Free the object if we are releasing the final
1059  *        reference.
1060  */
1061 void
prop_object_release(prop_object_t obj)1062 prop_object_release(prop_object_t obj)
1063 {
1064           struct _prop_object *po;
1065           struct _prop_stack stack;
1066           void (*unlock)(void);
1067           int ret;
1068           uint32_t ocnt;
1069 
1070           _prop_stack_init(&stack);
1071 
1072           do {
1073                     do {
1074                               po = obj;
1075                               _PROP_ASSERT(obj);
1076 
1077                               if (po->po_type->pot_lock != NULL)
1078                                         po->po_type->pot_lock();
1079 
1080                               /* Save pointer to object unlock function */
1081                               unlock = po->po_type->pot_unlock;
1082 
1083                               ocnt = atomic_dec_32_nv(&po->po_refcnt);
1084                               ocnt++;
1085                               _PROP_ASSERT(ocnt != 0);
1086 
1087                               if (ocnt != 1) {
1088                                         ret = 0;
1089                                         if (unlock != NULL)
1090                                                   unlock();
1091                                         break;
1092                               }
1093 
1094                               ret = (po->po_type->pot_free)(&stack, &obj);
1095 
1096                               if (unlock != NULL)
1097                                         unlock();
1098 
1099                               if (ret == _PROP_OBJECT_FREE_DONE)
1100                                         break;
1101 
1102                               atomic_inc_32(&po->po_refcnt);
1103                     } while (ret == _PROP_OBJECT_FREE_RECURSE);
1104                     if (ret == _PROP_OBJECT_FREE_FAILED)
1105                               prop_object_release_emergency(obj);
1106           } while (_prop_stack_pop(&stack, &obj, NULL, NULL, NULL));
1107 }
1108 
1109 /*
1110  * prop_object_type --
1111  *        Return the type of an object.
1112  */
1113 prop_type_t
prop_object_type(prop_object_t obj)1114 prop_object_type(prop_object_t obj)
1115 {
1116           struct _prop_object *po = obj;
1117 
1118           if (obj == NULL)
1119                     return (PROP_TYPE_UNKNOWN);
1120 
1121           return (po->po_type->pot_type);
1122 }
1123 
1124 /*
1125  * prop_object_equals --
1126  *        Returns true if thw two objects are equivalent.
1127  */
1128 bool
prop_object_equals(prop_object_t obj1,prop_object_t obj2)1129 prop_object_equals(prop_object_t obj1, prop_object_t obj2)
1130 {
1131           return (prop_object_equals_with_error(obj1, obj2, NULL));
1132 }
1133 
1134 bool
prop_object_equals_with_error(prop_object_t obj1,prop_object_t obj2,bool * error_flag)1135 prop_object_equals_with_error(prop_object_t obj1, prop_object_t obj2,
1136     bool *error_flag)
1137 {
1138           struct _prop_object *po1;
1139           struct _prop_object *po2;
1140           void *stored_pointer1, *stored_pointer2;
1141           prop_object_t next_obj1, next_obj2;
1142           struct _prop_stack stack;
1143           _prop_object_equals_rv_t ret;
1144 
1145           _prop_stack_init(&stack);
1146           if (error_flag)
1147                     *error_flag = false;
1148 
1149  start_subtree:
1150           stored_pointer1 = NULL;
1151           stored_pointer2 = NULL;
1152           po1 = obj1;
1153           po2 = obj2;
1154 
1155           if (po1->po_type != po2->po_type)
1156                     return (false);
1157 
1158  continue_subtree:
1159           ret = (*po1->po_type->pot_equals)(obj1, obj2,
1160                                                     &stored_pointer1, &stored_pointer2,
1161                                                     &next_obj1, &next_obj2);
1162           if (ret == _PROP_OBJECT_EQUALS_FALSE)
1163                     goto finish;
1164           if (ret == _PROP_OBJECT_EQUALS_TRUE) {
1165                     if (!_prop_stack_pop(&stack, &obj1, &obj2,
1166                                              &stored_pointer1, &stored_pointer2))
1167                               return true;
1168                     po1 = obj1;
1169                     po2 = obj2;
1170                     goto continue_subtree;
1171           }
1172           _PROP_ASSERT(ret == _PROP_OBJECT_EQUALS_RECURSE);
1173 
1174           if (!_prop_stack_push(&stack, obj1, obj2,
1175                                     stored_pointer1, stored_pointer2)) {
1176                     if (error_flag)
1177                               *error_flag = true;
1178                     goto finish;
1179           }
1180           obj1 = next_obj1;
1181           obj2 = next_obj2;
1182           goto start_subtree;
1183 
1184 finish:
1185           while (_prop_stack_pop(&stack, &obj1, &obj2, NULL, NULL)) {
1186                     po1 = obj1;
1187                     (*po1->po_type->pot_equals_finish)(obj1, obj2);
1188           }
1189           return (false);
1190 }
1191 
1192 /*
1193  * prop_object_iterator_next --
1194  *        Return the next item during an iteration.
1195  */
1196 prop_object_t
prop_object_iterator_next(prop_object_iterator_t pi)1197 prop_object_iterator_next(prop_object_iterator_t pi)
1198 {
1199 
1200           return ((*pi->pi_next_object)(pi));
1201 }
1202 
1203 /*
1204  * prop_object_iterator_reset --
1205  *        Reset the iterator to the first object so as to restart
1206  *        iteration.
1207  */
1208 void
prop_object_iterator_reset(prop_object_iterator_t pi)1209 prop_object_iterator_reset(prop_object_iterator_t pi)
1210 {
1211 
1212           (*pi->pi_reset)(pi);
1213 }
1214 
1215 /*
1216  * prop_object_iterator_release --
1217  *        Release the object iterator.
1218  */
1219 void
prop_object_iterator_release(prop_object_iterator_t pi)1220 prop_object_iterator_release(prop_object_iterator_t pi)
1221 {
1222 
1223           prop_object_release(pi->pi_obj);
1224           _PROP_FREE(pi, M_TEMP);
1225 }
1226