1 /* $NetBSD: prop_object.c,v 1.20 2008/02/23 01:26:01 lukem 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 * 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 _PROP_ARG_UNUSED) 100 { 101 /* Nothing to do, currently. */ 102 } 103 104 /* 105 * _prop_object_externalize_start_tag -- 106 * Append an XML-style start tag to the externalize buffer. 107 */ 108 bool 109 _prop_object_externalize_start_tag( 110 struct _prop_object_externalize_context *ctx, const char *tag) 111 { 112 unsigned int i; 113 114 for (i = 0; i < ctx->poec_depth; i++) { 115 if (_prop_object_externalize_append_char(ctx, '\t') == false) 116 return (false); 117 } 118 if (_prop_object_externalize_append_char(ctx, '<') == false || 119 _prop_object_externalize_append_cstring(ctx, tag) == false || 120 _prop_object_externalize_append_char(ctx, '>') == false) 121 return (false); 122 123 return (true); 124 } 125 126 /* 127 * _prop_object_externalize_end_tag -- 128 * Append an XML-style end tag to the externalize buffer. 129 */ 130 bool 131 _prop_object_externalize_end_tag( 132 struct _prop_object_externalize_context *ctx, const char *tag) 133 { 134 135 if (_prop_object_externalize_append_char(ctx, '<') == false || 136 _prop_object_externalize_append_char(ctx, '/') == false || 137 _prop_object_externalize_append_cstring(ctx, tag) == false || 138 _prop_object_externalize_append_char(ctx, '>') == false || 139 _prop_object_externalize_append_char(ctx, '\n') == false) 140 return (false); 141 142 return (true); 143 } 144 145 /* 146 * _prop_object_externalize_empty_tag -- 147 * Append an XML-style empty tag to the externalize buffer. 148 */ 149 bool 150 _prop_object_externalize_empty_tag( 151 struct _prop_object_externalize_context *ctx, const char *tag) 152 { 153 unsigned int i; 154 155 for (i = 0; i < ctx->poec_depth; i++) { 156 if (_prop_object_externalize_append_char(ctx, '\t') == false) 157 return (false); 158 } 159 160 if (_prop_object_externalize_append_char(ctx, '<') == false || 161 _prop_object_externalize_append_cstring(ctx, tag) == false || 162 _prop_object_externalize_append_char(ctx, '/') == false || 163 _prop_object_externalize_append_char(ctx, '>') == false || 164 _prop_object_externalize_append_char(ctx, '\n') == false) 165 return (false); 166 167 return (true); 168 } 169 170 /* 171 * _prop_object_externalize_append_cstring -- 172 * Append a C string to the externalize buffer. 173 */ 174 bool 175 _prop_object_externalize_append_cstring( 176 struct _prop_object_externalize_context *ctx, const char *cp) 177 { 178 179 while (*cp != '\0') { 180 if (_prop_object_externalize_append_char(ctx, 181 (unsigned char) *cp) == false) 182 return (false); 183 cp++; 184 } 185 186 return (true); 187 } 188 189 /* 190 * _prop_object_externalize_append_encoded_cstring -- 191 * Append an encoded C string to the externalize buffer. 192 */ 193 bool 194 _prop_object_externalize_append_encoded_cstring( 195 struct _prop_object_externalize_context *ctx, const char *cp) 196 { 197 198 while (*cp != '\0') { 199 switch (*cp) { 200 case '<': 201 if (_prop_object_externalize_append_cstring(ctx, 202 "<") == false) 203 return (false); 204 break; 205 case '>': 206 if (_prop_object_externalize_append_cstring(ctx, 207 ">") == false) 208 return (false); 209 break; 210 case '&': 211 if (_prop_object_externalize_append_cstring(ctx, 212 "&") == false) 213 return (false); 214 break; 215 default: 216 if (_prop_object_externalize_append_char(ctx, 217 (unsigned char) *cp) == false) 218 return (false); 219 break; 220 } 221 cp++; 222 } 223 224 return (true); 225 } 226 227 #define BUF_EXPAND 256 228 229 /* 230 * _prop_object_externalize_append_char -- 231 * Append a single character to the externalize buffer. 232 */ 233 bool 234 _prop_object_externalize_append_char( 235 struct _prop_object_externalize_context *ctx, unsigned char c) 236 { 237 238 _PROP_ASSERT(ctx->poec_capacity != 0); 239 _PROP_ASSERT(ctx->poec_buf != NULL); 240 _PROP_ASSERT(ctx->poec_len <= ctx->poec_capacity); 241 242 if (ctx->poec_len == ctx->poec_capacity) { 243 char *cp = _PROP_REALLOC(ctx->poec_buf, 244 ctx->poec_capacity + BUF_EXPAND, 245 M_TEMP); 246 if (cp == NULL) 247 return (false); 248 ctx->poec_capacity = ctx->poec_capacity + BUF_EXPAND; 249 ctx->poec_buf = cp; 250 } 251 252 ctx->poec_buf[ctx->poec_len++] = c; 253 254 return (true); 255 } 256 257 /* 258 * _prop_object_externalize_header -- 259 * Append the standard XML header to the externalize buffer. 260 */ 261 bool 262 _prop_object_externalize_header(struct _prop_object_externalize_context *ctx) 263 { 264 static const char _plist_xml_header[] = 265 "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n" 266 "<!DOCTYPE plist PUBLIC \"-//Apple Computer//DTD PLIST 1.0//EN\" \"http://www.apple.com/DTDs/PropertyList-1.0.dtd\">\n"; 267 268 if (_prop_object_externalize_append_cstring(ctx, 269 _plist_xml_header) == false || 270 _prop_object_externalize_start_tag(ctx, 271 "plist version=\"1.0\"") == false || 272 _prop_object_externalize_append_char(ctx, '\n') == false) 273 return (false); 274 275 return (true); 276 } 277 278 /* 279 * _prop_object_externalize_footer -- 280 * Append the standard XML footer to the externalize buffer. This 281 * also NUL-terminates the buffer. 282 */ 283 bool 284 _prop_object_externalize_footer(struct _prop_object_externalize_context *ctx) 285 { 286 287 if (_prop_object_externalize_end_tag(ctx, "plist") == false || 288 _prop_object_externalize_append_char(ctx, '\0') == false) 289 return (false); 290 291 return (true); 292 } 293 294 /* 295 * _prop_object_externalize_context_alloc -- 296 * Allocate an externalize context. 297 */ 298 struct _prop_object_externalize_context * 299 _prop_object_externalize_context_alloc(void) 300 { 301 struct _prop_object_externalize_context *ctx; 302 303 ctx = _PROP_MALLOC(sizeof(*ctx), M_TEMP); 304 if (ctx != NULL) { 305 ctx->poec_buf = _PROP_MALLOC(BUF_EXPAND, M_TEMP); 306 if (ctx->poec_buf == NULL) { 307 _PROP_FREE(ctx, M_TEMP); 308 return (NULL); 309 } 310 ctx->poec_len = 0; 311 ctx->poec_capacity = BUF_EXPAND; 312 ctx->poec_depth = 0; 313 } 314 return (ctx); 315 } 316 317 /* 318 * _prop_object_externalize_context_free -- 319 * Free an externalize context. 320 */ 321 void 322 _prop_object_externalize_context_free( 323 struct _prop_object_externalize_context *ctx) 324 { 325 326 /* Buffer is always freed by the caller. */ 327 _PROP_FREE(ctx, M_TEMP); 328 } 329 330 /* 331 * _prop_object_internalize_skip_comment -- 332 * Skip the body and end tag of a comment. 333 */ 334 static bool 335 _prop_object_internalize_skip_comment( 336 struct _prop_object_internalize_context *ctx) 337 { 338 const char *cp = ctx->poic_cp; 339 340 while (!_PROP_EOF(*cp)) { 341 if (cp[0] == '-' && 342 cp[1] == '-' && 343 cp[2] == '>') { 344 ctx->poic_cp = cp + 3; 345 return (true); 346 } 347 cp++; 348 } 349 350 return (false); /* ran out of buffer */ 351 } 352 353 /* 354 * _prop_object_internalize_find_tag -- 355 * Find the next tag in an XML stream. Optionally compare the found 356 * tag to an expected tag name. State of the context is undefined 357 * if this routine returns false. Upon success, the context points 358 * to the first octet after the tag. 359 */ 360 bool 361 _prop_object_internalize_find_tag(struct _prop_object_internalize_context *ctx, 362 const char *tag, _prop_tag_type_t type) 363 { 364 const char *cp; 365 size_t taglen; 366 367 if (tag != NULL) 368 taglen = strlen(tag); 369 else 370 taglen = 0; 371 372 start_over: 373 cp = ctx->poic_cp; 374 375 /* 376 * Find the start of the tag. 377 */ 378 while (_PROP_ISSPACE(*cp)) 379 cp++; 380 if (_PROP_EOF(*cp)) 381 return (false); 382 383 if (*cp != '<') 384 return (false); 385 386 ctx->poic_tag_start = cp++; 387 if (_PROP_EOF(*cp)) 388 return (false); 389 390 if (*cp == '!') { 391 if (cp[1] != '-' || cp[2] != '-') 392 return (false); 393 /* 394 * Comment block -- only allowed if we are allowed to 395 * return a start tag. 396 */ 397 if (type == _PROP_TAG_TYPE_END) 398 return (false); 399 ctx->poic_cp = cp + 3; 400 if (_prop_object_internalize_skip_comment(ctx) == false) 401 return (false); 402 goto start_over; 403 } 404 405 if (*cp == '/') { 406 if (type != _PROP_TAG_TYPE_END && 407 type != _PROP_TAG_TYPE_EITHER) 408 return (false); 409 cp++; 410 if (_PROP_EOF(*cp)) 411 return (false); 412 ctx->poic_tag_type = _PROP_TAG_TYPE_END; 413 } else { 414 if (type != _PROP_TAG_TYPE_START && 415 type != _PROP_TAG_TYPE_EITHER) 416 return (false); 417 ctx->poic_tag_type = _PROP_TAG_TYPE_START; 418 } 419 420 ctx->poic_tagname = cp; 421 422 while (!_PROP_ISSPACE(*cp) && *cp != '/' && *cp != '>') 423 cp++; 424 if (_PROP_EOF(*cp)) 425 return (false); 426 427 ctx->poic_tagname_len = cp - ctx->poic_tagname; 428 429 /* Make sure this is the tag we're looking for. */ 430 if (tag != NULL && 431 (taglen != ctx->poic_tagname_len || 432 memcmp(tag, ctx->poic_tagname, taglen) != 0)) 433 return (false); 434 435 /* Check for empty tag. */ 436 if (*cp == '/') { 437 if (ctx->poic_tag_type != _PROP_TAG_TYPE_START) 438 return(false); /* only valid on start tags */ 439 ctx->poic_is_empty_element = true; 440 cp++; 441 if (_PROP_EOF(*cp) || *cp != '>') 442 return (false); 443 } else 444 ctx->poic_is_empty_element = false; 445 446 /* Easy case of no arguments. */ 447 if (*cp == '>') { 448 ctx->poic_tagattr = NULL; 449 ctx->poic_tagattr_len = 0; 450 ctx->poic_tagattrval = NULL; 451 ctx->poic_tagattrval_len = 0; 452 ctx->poic_cp = cp + 1; 453 return (true); 454 } 455 456 _PROP_ASSERT(!_PROP_EOF(*cp)); 457 cp++; 458 if (_PROP_EOF(*cp)) 459 return (false); 460 461 while (_PROP_ISSPACE(*cp)) 462 cp++; 463 if (_PROP_EOF(*cp)) 464 return (false); 465 466 ctx->poic_tagattr = cp; 467 468 while (!_PROP_ISSPACE(*cp) && *cp != '=') 469 cp++; 470 if (_PROP_EOF(*cp)) 471 return (false); 472 473 ctx->poic_tagattr_len = cp - ctx->poic_tagattr; 474 475 cp++; 476 if (*cp != '\"') 477 return (false); 478 cp++; 479 if (_PROP_EOF(*cp)) 480 return (false); 481 482 ctx->poic_tagattrval = cp; 483 while (*cp != '\"') 484 cp++; 485 if (_PROP_EOF(*cp)) 486 return (false); 487 ctx->poic_tagattrval_len = cp - ctx->poic_tagattrval; 488 489 cp++; 490 if (*cp != '>') 491 return (false); 492 493 ctx->poic_cp = cp + 1; 494 return (true); 495 } 496 497 /* 498 * _prop_object_internalize_decode_string -- 499 * Decode an encoded string. 500 */ 501 bool 502 _prop_object_internalize_decode_string( 503 struct _prop_object_internalize_context *ctx, 504 char *target, size_t targsize, size_t *sizep, 505 const char **cpp) 506 { 507 const char *src; 508 size_t tarindex; 509 char c; 510 511 tarindex = 0; 512 src = ctx->poic_cp; 513 514 for (;;) { 515 if (_PROP_EOF(*src)) 516 return (false); 517 if (*src == '<') { 518 break; 519 } 520 521 if ((c = *src) == '&') { 522 if (src[1] == 'a' && 523 src[2] == 'm' && 524 src[3] == 'p' && 525 src[4] == ';') { 526 c = '&'; 527 src += 5; 528 } else if (src[1] == 'l' && 529 src[2] == 't' && 530 src[3] == ';') { 531 c = '<'; 532 src += 4; 533 } else if (src[1] == 'g' && 534 src[2] == 't' && 535 src[3] == ';') { 536 c = '>'; 537 src += 4; 538 } else if (src[1] == 'a' && 539 src[2] == 'p' && 540 src[3] == 'o' && 541 src[4] == 's' && 542 src[5] == ';') { 543 c = '\''; 544 src += 6; 545 } else if (src[1] == 'q' && 546 src[2] == 'u' && 547 src[3] == 'o' && 548 src[4] == 't' && 549 src[5] == ';') { 550 c = '\"'; 551 src += 6; 552 } else 553 return (false); 554 } else 555 src++; 556 if (target) { 557 if (tarindex >= targsize) 558 return (false); 559 target[tarindex] = c; 560 } 561 tarindex++; 562 } 563 564 _PROP_ASSERT(*src == '<'); 565 if (sizep != NULL) 566 *sizep = tarindex; 567 if (cpp != NULL) 568 *cpp = src; 569 570 return (true); 571 } 572 573 /* 574 * _prop_object_internalize_match -- 575 * Returns true if the two character streams match. 576 */ 577 bool 578 _prop_object_internalize_match(const char *str1, size_t len1, 579 const char *str2, size_t len2) 580 { 581 582 return (len1 == len2 && memcmp(str1, str2, len1) == 0); 583 } 584 585 #define INTERNALIZER(t, f) \ 586 { t, sizeof(t) - 1, f } 587 588 static const struct _prop_object_internalizer { 589 const char *poi_tag; 590 size_t poi_taglen; 591 prop_object_internalizer_t poi_intern; 592 } _prop_object_internalizer_table[] = { 593 INTERNALIZER("array", _prop_array_internalize), 594 595 INTERNALIZER("true", _prop_bool_internalize), 596 INTERNALIZER("false", _prop_bool_internalize), 597 598 INTERNALIZER("data", _prop_data_internalize), 599 600 INTERNALIZER("dict", _prop_dictionary_internalize), 601 602 INTERNALIZER("integer", _prop_number_internalize), 603 604 INTERNALIZER("string", _prop_string_internalize), 605 606 { 0, 0, NULL } 607 }; 608 609 #undef INTERNALIZER 610 611 /* 612 * _prop_object_internalize_by_tag -- 613 * Determine the object type from the tag in the context and 614 * internalize it. 615 */ 616 prop_object_t 617 _prop_object_internalize_by_tag(struct _prop_object_internalize_context *ctx) 618 { 619 const struct _prop_object_internalizer *poi; 620 prop_object_t obj, parent_obj; 621 void *data, *iter; 622 prop_object_internalizer_continue_t iter_func; 623 struct _prop_stack stack; 624 625 _prop_stack_init(&stack); 626 627 match_start: 628 for (poi = _prop_object_internalizer_table; 629 poi->poi_tag != NULL; poi++) { 630 if (_prop_object_internalize_match(ctx->poic_tagname, 631 ctx->poic_tagname_len, 632 poi->poi_tag, 633 poi->poi_taglen)) 634 break; 635 } 636 if (poi == NULL) { 637 while (_prop_stack_pop(&stack, &obj, &iter, &data, NULL)) { 638 iter_func = (prop_object_internalizer_continue_t)iter; 639 (*iter_func)(&stack, &obj, ctx, data, NULL); 640 } 641 642 return (NULL); 643 } 644 645 obj = NULL; 646 if (!(*poi->poi_intern)(&stack, &obj, ctx)) 647 goto match_start; 648 649 parent_obj = obj; 650 while (_prop_stack_pop(&stack, &parent_obj, &iter, &data, NULL)) { 651 iter_func = (prop_object_internalizer_continue_t)iter; 652 if (!(*iter_func)(&stack, &parent_obj, ctx, data, obj)) 653 goto match_start; 654 obj = parent_obj; 655 } 656 657 return (parent_obj); 658 } 659 660 prop_object_t 661 _prop_generic_internalize(const char *xml, const char *master_tag) 662 { 663 prop_object_t obj = NULL; 664 struct _prop_object_internalize_context *ctx; 665 666 ctx = _prop_object_internalize_context_alloc(xml); 667 if (ctx == NULL) 668 return (NULL); 669 670 /* We start with a <plist> tag. */ 671 if (_prop_object_internalize_find_tag(ctx, "plist", 672 _PROP_TAG_TYPE_START) == false) 673 goto out; 674 675 /* Plist elements cannot be empty. */ 676 if (ctx->poic_is_empty_element) 677 goto out; 678 679 /* 680 * We don't understand any plist attributes, but Apple XML 681 * property lists often have a "version" attribute. If we 682 * see that one, we simply ignore it. 683 */ 684 if (ctx->poic_tagattr != NULL && 685 !_PROP_TAGATTR_MATCH(ctx, "version")) 686 goto out; 687 688 /* Next we expect to see opening master_tag. */ 689 if (_prop_object_internalize_find_tag(ctx, master_tag, 690 _PROP_TAG_TYPE_START) == false) 691 goto out; 692 693 obj = _prop_object_internalize_by_tag(ctx); 694 if (obj == NULL) 695 goto out; 696 697 /* 698 * We've advanced past the closing master_tag. 699 * Now we want </plist>. 700 */ 701 if (_prop_object_internalize_find_tag(ctx, "plist", 702 _PROP_TAG_TYPE_END) == false) { 703 prop_object_release(obj); 704 obj = NULL; 705 } 706 707 out: 708 _prop_object_internalize_context_free(ctx); 709 return (obj); 710 } 711 712 /* 713 * _prop_object_internalize_context_alloc -- 714 * Allocate an internalize context. 715 */ 716 struct _prop_object_internalize_context * 717 _prop_object_internalize_context_alloc(const char *xml) 718 { 719 struct _prop_object_internalize_context *ctx; 720 721 ctx = _PROP_MALLOC(sizeof(struct _prop_object_internalize_context), 722 M_TEMP); 723 if (ctx == NULL) 724 return (NULL); 725 726 ctx->poic_xml = ctx->poic_cp = xml; 727 728 /* 729 * Skip any whitespace and XML preamble stuff that we don't 730 * know about / care about. 731 */ 732 for (;;) { 733 while (_PROP_ISSPACE(*xml)) 734 xml++; 735 if (_PROP_EOF(*xml) || *xml != '<') 736 goto bad; 737 738 #define MATCH(str) (memcmp(&xml[1], str, sizeof(str) - 1) == 0) 739 740 /* 741 * Skip over the XML preamble that Apple XML property 742 * lists usually include at the top of the file. 743 */ 744 if (MATCH("?xml ") || 745 MATCH("!DOCTYPE plist")) { 746 while (*xml != '>' && !_PROP_EOF(*xml)) 747 xml++; 748 if (_PROP_EOF(*xml)) 749 goto bad; 750 xml++; /* advance past the '>' */ 751 continue; 752 } 753 754 if (MATCH("<!--")) { 755 ctx->poic_cp = xml + 4; 756 if (_prop_object_internalize_skip_comment(ctx) == false) 757 goto bad; 758 xml = ctx->poic_cp; 759 continue; 760 } 761 762 #undef MATCH 763 764 /* 765 * We don't think we should skip it, so let's hope we can 766 * parse it. 767 */ 768 break; 769 } 770 771 ctx->poic_cp = xml; 772 return (ctx); 773 bad: 774 _PROP_FREE(ctx, M_TEMP); 775 return (NULL); 776 } 777 778 /* 779 * _prop_object_internalize_context_free -- 780 * Free an internalize context. 781 */ 782 void 783 _prop_object_internalize_context_free( 784 struct _prop_object_internalize_context *ctx) 785 { 786 787 _PROP_FREE(ctx, M_TEMP); 788 } 789 790 #if !defined(_KERNEL) && !defined(_STANDALONE) 791 /* 792 * _prop_object_externalize_file_dirname -- 793 * dirname(3), basically. We have to roll our own because the 794 * system dirname(3) isn't reentrant. 795 */ 796 static void 797 _prop_object_externalize_file_dirname(const char *path, char *result) 798 { 799 const char *lastp; 800 size_t len; 801 802 /* 803 * If `path' is a NULL pointer or points to an empty string, 804 * return ".". 805 */ 806 if (path == NULL || *path == '\0') 807 goto singledot; 808 809 /* String trailing slashes, if any. */ 810 lastp = path + strlen(path) - 1; 811 while (lastp != path && *lastp == '/') 812 lastp--; 813 814 /* Terminate path at the last occurrence of '/'. */ 815 do { 816 if (*lastp == '/') { 817 /* Strip trailing slashes, if any. */ 818 while (lastp != path && *lastp == '/') 819 lastp--; 820 821 /* ...and copy the result into the result buffer. */ 822 len = (lastp - path) + 1 /* last char */; 823 if (len > (PATH_MAX - 1)) 824 len = PATH_MAX - 1; 825 826 memcpy(result, path, len); 827 result[len] = '\0'; 828 return; 829 } 830 } while (--lastp >= path); 831 832 /* No /'s found, return ".". */ 833 singledot: 834 strcpy(result, "."); 835 } 836 837 /* 838 * _prop_object_externalize_write_file -- 839 * Write an externalized dictionary to the specified file. 840 * The file is written atomically from the caller's perspective, 841 * and the mode set to 0666 modified by the caller's umask. 842 */ 843 bool 844 _prop_object_externalize_write_file(const char *fname, const char *xml, 845 size_t len) 846 { 847 char tname[PATH_MAX]; 848 int fd; 849 int save_errno; 850 mode_t myumask; 851 852 if (len > SSIZE_MAX) { 853 errno = EFBIG; 854 return (false); 855 } 856 857 /* 858 * Get the directory name where the file is to be written 859 * and create the temporary file. 860 */ 861 _prop_object_externalize_file_dirname(fname, tname); 862 if (strlcat(tname, "/.plistXXXXXX", sizeof(tname)) >= sizeof(tname)) { 863 errno = ENAMETOOLONG; 864 return (false); 865 } 866 if ((fd = mkstemp(tname)) == -1) 867 return (false); 868 869 if (write(fd, xml, len) != (ssize_t)len) 870 goto bad; 871 872 if (fsync(fd) == -1) 873 goto bad; 874 875 myumask = umask(0); 876 (void)umask(myumask); 877 if (fchmod(fd, 0666 & ~myumask) == -1) 878 goto bad; 879 880 (void) close(fd); 881 fd = -1; 882 883 if (rename(tname, fname) == -1) 884 goto bad; 885 886 return (true); 887 888 bad: 889 save_errno = errno; 890 if (fd != -1) 891 (void) close(fd); 892 (void) unlink(tname); 893 errno = save_errno; 894 return (false); 895 } 896 897 /* 898 * _prop_object_internalize_map_file -- 899 * Map a file for the purpose of internalizing it. 900 */ 901 struct _prop_object_internalize_mapped_file * 902 _prop_object_internalize_map_file(const char *fname) 903 { 904 struct stat sb; 905 struct _prop_object_internalize_mapped_file *mf; 906 size_t pgsize = (size_t)sysconf(_SC_PAGESIZE); 907 size_t pgmask = pgsize - 1; 908 bool need_guard = false; 909 int fd; 910 911 mf = _PROP_MALLOC(sizeof(*mf), M_TEMP); 912 if (mf == NULL) 913 return (NULL); 914 915 fd = open(fname, O_RDONLY, 0400); 916 if (fd == -1) { 917 _PROP_FREE(mf, M_TEMP); 918 return (NULL); 919 } 920 921 if (fstat(fd, &sb) == -1) { 922 (void) close(fd); 923 _PROP_FREE(mf, M_TEMP); 924 return (NULL); 925 } 926 mf->poimf_mapsize = ((size_t)sb.st_size + pgmask) & ~pgmask; 927 if (mf->poimf_mapsize < sb.st_size) { 928 (void) close(fd); 929 _PROP_FREE(mf, M_TEMP); 930 return (NULL); 931 } 932 933 /* 934 * If the file length is an integral number of pages, then we 935 * need to map a guard page at the end in order to provide the 936 * necessary NUL-termination of the buffer. 937 */ 938 if ((sb.st_size & pgmask) == 0) 939 need_guard = true; 940 941 mf->poimf_xml = mmap(NULL, need_guard ? mf->poimf_mapsize + pgsize 942 : mf->poimf_mapsize, 943 PROT_READ, MAP_FILE|MAP_SHARED, fd, (off_t)0); 944 (void) close(fd); 945 if (mf->poimf_xml == MAP_FAILED) { 946 _PROP_FREE(mf, M_TEMP); 947 return (NULL); 948 } 949 (void) madvise(mf->poimf_xml, mf->poimf_mapsize, MADV_SEQUENTIAL); 950 951 if (need_guard) { 952 if (mmap(mf->poimf_xml + mf->poimf_mapsize, 953 pgsize, PROT_READ, 954 MAP_ANON|MAP_PRIVATE|MAP_FIXED, -1, 955 (off_t)0) == MAP_FAILED) { 956 (void) munmap(mf->poimf_xml, mf->poimf_mapsize); 957 _PROP_FREE(mf, M_TEMP); 958 return (NULL); 959 } 960 mf->poimf_mapsize += pgsize; 961 } 962 963 return (mf); 964 } 965 966 /* 967 * _prop_object_internalize_unmap_file -- 968 * Unmap a file previously mapped for internalizing. 969 */ 970 void 971 _prop_object_internalize_unmap_file( 972 struct _prop_object_internalize_mapped_file *mf) 973 { 974 975 (void) madvise(mf->poimf_xml, mf->poimf_mapsize, MADV_DONTNEED); 976 (void) munmap(mf->poimf_xml, mf->poimf_mapsize); 977 _PROP_FREE(mf, M_TEMP); 978 } 979 #endif /* !_KERNEL && !_STANDALONE */ 980 981 /* 982 * Retain / release serialization -- 983 * 984 * Eventually we would like to use atomic operations. But until we have 985 * an MI API for them that is common to userland and the kernel, we will 986 * use a lock instead. 987 * 988 * We use a single global mutex for all serialization. In the kernel, because 989 * we are still under a biglock, this will basically never contend (properties 990 * cannot be manipulated at interrupt level). In userland, this will cost 991 * nothing for single-threaded programs. For multi-threaded programs, there 992 * could be contention, but it probably won't cost that much unless the program 993 * makes heavy use of property lists. 994 */ 995 _PROP_MUTEX_DECL_STATIC(_prop_refcnt_mutex) 996 #define _PROP_REFCNT_LOCK() _PROP_MUTEX_LOCK(_prop_refcnt_mutex) 997 #define _PROP_REFCNT_UNLOCK() _PROP_MUTEX_UNLOCK(_prop_refcnt_mutex) 998 999 /* 1000 * prop_object_retain -- 1001 * Increment the reference count on an object. 1002 */ 1003 void 1004 prop_object_retain(prop_object_t obj) 1005 { 1006 struct _prop_object *po = obj; 1007 uint32_t ocnt; 1008 1009 _PROP_REFCNT_LOCK(); 1010 ocnt = po->po_refcnt++; 1011 _PROP_REFCNT_UNLOCK(); 1012 1013 _PROP_ASSERT(ocnt != 0xffffffffU); 1014 } 1015 1016 /* 1017 * prop_object_release_emergency 1018 * A direct free with prop_object_release failed. 1019 * Walk down the tree until a leaf is found and 1020 * free that. Do not recurse to avoid stack overflows. 1021 * 1022 * This is a slow edge condition, but necessary to 1023 * guarantee that an object can always be freed. 1024 */ 1025 static void 1026 prop_object_release_emergency(prop_object_t obj) 1027 { 1028 struct _prop_object *po; 1029 prop_object_t parent = NULL; 1030 uint32_t ocnt; 1031 1032 for (;;) { 1033 po = obj; 1034 _PROP_ASSERT(obj); 1035 1036 _PROP_REFCNT_LOCK(); 1037 ocnt = po->po_refcnt--; 1038 _PROP_REFCNT_UNLOCK(); 1039 1040 _PROP_ASSERT(ocnt != 0); 1041 if (ocnt != 1) 1042 break; 1043 1044 _PROP_ASSERT(po->po_type); 1045 if ((po->po_type->pot_free)(NULL, &obj) == 0) 1046 break; 1047 1048 parent = po; 1049 _PROP_REFCNT_LOCK(); 1050 ++po->po_refcnt; 1051 _PROP_REFCNT_UNLOCK(); 1052 } 1053 _PROP_ASSERT(parent); 1054 /* One object was just freed. */ 1055 po = parent; 1056 (*po->po_type->pot_emergency_free)(parent); 1057 } 1058 1059 /* 1060 * prop_object_release -- 1061 * Decrement the reference count on an object. 1062 * 1063 * Free the object if we are releasing the final 1064 * reference. 1065 */ 1066 void 1067 prop_object_release(prop_object_t obj) 1068 { 1069 struct _prop_object *po; 1070 struct _prop_stack stack; 1071 int ret; 1072 uint32_t ocnt; 1073 1074 _prop_stack_init(&stack); 1075 1076 do { 1077 do { 1078 po = obj; 1079 _PROP_ASSERT(obj); 1080 1081 _PROP_REFCNT_LOCK(); 1082 ocnt = po->po_refcnt--; 1083 _PROP_REFCNT_UNLOCK(); 1084 1085 _PROP_ASSERT(ocnt != 0); 1086 if (ocnt != 1) { 1087 ret = 0; 1088 break; 1089 } 1090 1091 ret = (po->po_type->pot_free)(&stack, &obj); 1092 1093 if (ret == _PROP_OBJECT_FREE_DONE) 1094 break; 1095 1096 _PROP_REFCNT_LOCK(); 1097 ++po->po_refcnt; 1098 _PROP_REFCNT_UNLOCK(); 1099 } while (ret == _PROP_OBJECT_FREE_RECURSE); 1100 if (ret == _PROP_OBJECT_FREE_FAILED) 1101 prop_object_release_emergency(obj); 1102 } while (_prop_stack_pop(&stack, &obj, NULL, NULL, NULL)); 1103 } 1104 1105 /* 1106 * prop_object_type -- 1107 * Return the type of an object. 1108 */ 1109 prop_type_t 1110 prop_object_type(prop_object_t obj) 1111 { 1112 struct _prop_object *po = obj; 1113 1114 if (obj == NULL) 1115 return (PROP_TYPE_UNKNOWN); 1116 1117 return (po->po_type->pot_type); 1118 } 1119 1120 /* 1121 * prop_object_equals -- 1122 * Returns true if thw two objects are equivalent. 1123 */ 1124 bool 1125 prop_object_equals(prop_object_t obj1, prop_object_t obj2) 1126 { 1127 return (prop_object_equals_with_error(obj1, obj2, NULL)); 1128 } 1129 1130 bool 1131 prop_object_equals_with_error(prop_object_t obj1, prop_object_t obj2, 1132 bool *error_flag) 1133 { 1134 struct _prop_object *po1; 1135 struct _prop_object *po2; 1136 void *stored_pointer1, *stored_pointer2; 1137 prop_object_t next_obj1, next_obj2; 1138 struct _prop_stack stack; 1139 int ret; 1140 1141 _prop_stack_init(&stack); 1142 if (error_flag) 1143 *error_flag = false; 1144 1145 start_subtree: 1146 stored_pointer1 = NULL; 1147 stored_pointer2 = NULL; 1148 po1 = obj1; 1149 po2 = obj2; 1150 1151 if (po1->po_type != po2->po_type) 1152 return (false); 1153 1154 continue_subtree: 1155 ret = (*po1->po_type->pot_equals)(obj1, obj2, &stored_pointer1, &stored_pointer2, 1156 &next_obj1, &next_obj2); 1157 if (ret == _PROP_OBJECT_EQUALS_FALSE) 1158 goto finish; 1159 if (ret == _PROP_OBJECT_EQUALS_TRUE) { 1160 if (!_prop_stack_pop(&stack, &obj1, &obj2, 1161 &stored_pointer1, &stored_pointer2)) 1162 return true; 1163 goto continue_subtree; 1164 } 1165 _PROP_ASSERT(ret == _PROP_OBJECT_EQUALS_RECURSE); 1166 1167 if (!_prop_stack_push(&stack, obj1, obj2, 1168 stored_pointer1, stored_pointer2)) { 1169 if (error_flag) 1170 *error_flag = true; 1171 goto finish; 1172 } 1173 obj1 = next_obj1; 1174 obj2 = next_obj2; 1175 goto start_subtree; 1176 1177 finish: 1178 while (_prop_stack_pop(&stack, &obj1, &obj2, NULL, NULL)) { 1179 po1 = obj1; 1180 (*po1->po_type->pot_equals_finish)(obj1, obj2); 1181 } 1182 return (false); 1183 } 1184 1185 /* 1186 * prop_object_iterator_next -- 1187 * Return the next item during an iteration. 1188 */ 1189 prop_object_t 1190 prop_object_iterator_next(prop_object_iterator_t pi) 1191 { 1192 1193 return ((*pi->pi_next_object)(pi)); 1194 } 1195 1196 /* 1197 * prop_object_iterator_reset -- 1198 * Reset the iterator to the first object so as to restart 1199 * iteration. 1200 */ 1201 void 1202 prop_object_iterator_reset(prop_object_iterator_t pi) 1203 { 1204 1205 (*pi->pi_reset)(pi); 1206 } 1207 1208 /* 1209 * prop_object_iterator_release -- 1210 * Release the object iterator. 1211 */ 1212 void 1213 prop_object_iterator_release(prop_object_iterator_t pi) 1214 { 1215 1216 prop_object_release(pi->pi_obj); 1217 _PROP_FREE(pi, M_TEMP); 1218 } 1219