1// SPDX-License-Identifier: LGPL-2.1+ 2/* 3 * This implementation is based on code from uClibc-0.9.30.3 but was 4 * modified and extended for use within U-Boot. 5 * 6 * Copyright (C) 2010-2013 Wolfgang Denk <wd@denx.de> 7 * 8 * Original license header: 9 * 10 * Copyright (C) 1993, 1995, 1996, 1997, 2002 Free Software Foundation, Inc. 11 * This file is part of the GNU C Library. 12 * Contributed by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1993. 13 */ 14 15#include <errno.h> 16#include <log.h> 17#include <malloc.h> 18#include <sort.h> 19 20#ifdef USE_HOSTCC /* HOST build */ 21# include <string.h> 22# include <assert.h> 23# include <ctype.h> 24 25# ifndef debug 26# ifdef DEBUG 27# define debug(fmt,args...) printf(fmt ,##args) 28# else 29# define debug(fmt,args...) 30# endif 31# endif 32#else /* U-Boot build */ 33# include <linux/string.h> 34# include <linux/ctype.h> 35#endif 36 37#define USED_FREE 0 38#define USED_DELETED -1 39 40#include <env_callback.h> 41#include <env_flags.h> 42#include <search.h> 43#include <slre.h> 44 45/* 46 * [Aho,Sethi,Ullman] Compilers: Principles, Techniques and Tools, 1986 47 * [Knuth] The Art of Computer Programming, part 3 (6.4) 48 */ 49 50/* 51 * The reentrant version has no static variables to maintain the state. 52 * Instead the interface of all functions is extended to take an argument 53 * which describes the current status. 54 */ 55 56struct env_entry_node { 57 int used; 58 struct env_entry entry; 59}; 60 61 62static void _hdelete(const char *key, struct hsearch_data *htab, 63 struct env_entry *ep, int idx); 64 65/* 66 * hcreate() 67 */ 68 69/* 70 * For the used double hash method the table size has to be a prime. To 71 * correct the user given table size we need a prime test. This trivial 72 * algorithm is adequate because 73 * a) the code is (most probably) called a few times per program run and 74 * b) the number is small because the table must fit in the core 75 * */ 76static int isprime(unsigned int number) 77{ 78 /* no even number will be passed */ 79 unsigned int div = 3; 80 81 while (div * div < number && number % div != 0) 82 div += 2; 83 84 return number % div != 0; 85} 86 87/* 88 * Before using the hash table we must allocate memory for it. 89 * Test for an existing table are done. We allocate one element 90 * more as the found prime number says. This is done for more effective 91 * indexing as explained in the comment for the hsearch function. 92 * The contents of the table is zeroed, especially the field used 93 * becomes zero. 94 */ 95 96int hcreate_r(size_t nel, struct hsearch_data *htab) 97{ 98 /* Test for correct arguments. */ 99 if (htab == NULL) { 100 __set_errno(EINVAL); 101 return 0; 102 } 103 104 /* There is still another table active. Return with error. */ 105 if (htab->table != NULL) { 106 __set_errno(EINVAL); 107 return 0; 108 } 109 110 /* Change nel to the first prime number not smaller as nel. */ 111 nel |= 1; /* make odd */ 112 while (!isprime(nel)) 113 nel += 2; 114 115 htab->size = nel; 116 htab->filled = 0; 117 118 /* allocate memory and zero out */ 119 htab->table = (struct env_entry_node *)calloc(htab->size + 1, 120 sizeof(struct env_entry_node)); 121 if (htab->table == NULL) { 122 __set_errno(ENOMEM); 123 return 0; 124 } 125 126 /* everything went alright */ 127 return 1; 128} 129 130 131/* 132 * hdestroy() 133 */ 134 135/* 136 * After using the hash table it has to be destroyed. The used memory can 137 * be freed and the local static variable can be marked as not used. 138 */ 139 140void hdestroy_r(struct hsearch_data *htab) 141{ 142 int i; 143 144 /* Test for correct arguments. */ 145 if (htab == NULL) { 146 __set_errno(EINVAL); 147 return; 148 } 149 150 /* free used memory */ 151 for (i = 1; i <= htab->size; ++i) { 152 if (htab->table[i].used > 0) { 153 struct env_entry *ep = &htab->table[i].entry; 154 155 free((void *)ep->key); 156 free(ep->data); 157 } 158 } 159 free(htab->table); 160 161 /* the sign for an existing table is an value != NULL in htable */ 162 htab->table = NULL; 163} 164 165/* 166 * hsearch() 167 */ 168 169/* 170 * This is the search function. It uses double hashing with open addressing. 171 * The argument item.key has to be a pointer to an zero terminated, most 172 * probably strings of chars. The function for generating a number of the 173 * strings is simple but fast. It can be replaced by a more complex function 174 * like ajw (see [Aho,Sethi,Ullman]) if the needs are shown. 175 * 176 * We use an trick to speed up the lookup. The table is created by hcreate 177 * with one more element available. This enables us to use the index zero 178 * special. This index will never be used because we store the first hash 179 * index in the field used where zero means not used. Every other value 180 * means used. The used field can be used as a first fast comparison for 181 * equality of the stored and the parameter value. This helps to prevent 182 * unnecessary expensive calls of strcmp. 183 * 184 * This implementation differs from the standard library version of 185 * this function in a number of ways: 186 * 187 * - While the standard version does not make any assumptions about 188 * the type of the stored data objects at all, this implementation 189 * works with NUL terminated strings only. 190 * - Instead of storing just pointers to the original objects, we 191 * create local copies so the caller does not need to care about the 192 * data any more. 193 * - The standard implementation does not provide a way to update an 194 * existing entry. This version will create a new entry or update an 195 * existing one when both "action == ENV_ENTER" and "item.data != NULL". 196 * - Instead of returning 1 on success, we return the index into the 197 * internal hash table, which is also guaranteed to be positive. 198 * This allows us direct access to the found hash table slot for 199 * example for functions like hdelete(). 200 */ 201 202int hmatch_r(const char *match, int last_idx, struct env_entry **retval, 203 struct hsearch_data *htab) 204{ 205 unsigned int idx; 206 size_t key_len = strlen(match); 207 208 for (idx = last_idx + 1; idx < htab->size; ++idx) { 209 if (htab->table[idx].used <= 0) 210 continue; 211 if (!strncmp(match, htab->table[idx].entry.key, key_len)) { 212 *retval = &htab->table[idx].entry; 213 return idx; 214 } 215 } 216 217 __set_errno(ESRCH); 218 *retval = NULL; 219 return 0; 220} 221 222static int 223do_callback(const struct env_entry *e, const char *name, const char *value, 224 enum env_op op, int flags) 225{ 226#ifndef CONFIG_SPL_BUILD 227 if (e->callback) 228 return e->callback(name, value, op, flags); 229#endif 230 return 0; 231} 232 233/* 234 * Compare an existing entry with the desired key, and overwrite if the action 235 * is ENV_ENTER. This is simply a helper function for hsearch_r(). 236 */ 237static inline int _compare_and_overwrite_entry(struct env_entry item, 238 enum env_action action, struct env_entry **retval, 239 struct hsearch_data *htab, int flag, unsigned int hval, 240 unsigned int idx) 241{ 242 if (htab->table[idx].used == hval 243 && strcmp(item.key, htab->table[idx].entry.key) == 0) { 244 /* Overwrite existing value? */ 245 if (action == ENV_ENTER && item.data) { 246 /* check for permission */ 247 if (htab->change_ok != NULL && htab->change_ok( 248 &htab->table[idx].entry, item.data, 249 env_op_overwrite, flag)) { 250 debug("change_ok() rejected setting variable " 251 "%s, skipping it!\n", item.key); 252 __set_errno(EPERM); 253 *retval = NULL; 254 return 0; 255 } 256 257 /* If there is a callback, call it */ 258 if (do_callback(&htab->table[idx].entry, item.key, 259 item.data, env_op_overwrite, flag)) { 260 debug("callback() rejected setting variable " 261 "%s, skipping it!\n", item.key); 262 __set_errno(EINVAL); 263 *retval = NULL; 264 return 0; 265 } 266 267 free(htab->table[idx].entry.data); 268 htab->table[idx].entry.data = strdup(item.data); 269 if (!htab->table[idx].entry.data) { 270 __set_errno(ENOMEM); 271 *retval = NULL; 272 return 0; 273 } 274 } 275 /* return found entry */ 276 *retval = &htab->table[idx].entry; 277 return idx; 278 } 279 /* keep searching */ 280 return -1; 281} 282 283int hsearch_r(struct env_entry item, enum env_action action, 284 struct env_entry **retval, struct hsearch_data *htab, int flag) 285{ 286 unsigned int hval; 287 unsigned int count; 288 unsigned int len = strlen(item.key); 289 unsigned int idx; 290 unsigned int first_deleted = 0; 291 int ret; 292 293 /* Compute an value for the given string. Perhaps use a better method. */ 294 hval = len; 295 count = len; 296 while (count-- > 0) { 297 hval <<= 4; 298 hval += item.key[count]; 299 } 300 301 /* 302 * First hash function: 303 * simply take the modul but prevent zero. 304 */ 305 hval %= htab->size; 306 if (hval == 0) 307 ++hval; 308 309 /* The first index tried. */ 310 idx = hval; 311 312 if (htab->table[idx].used) { 313 /* 314 * Further action might be required according to the 315 * action value. 316 */ 317 unsigned hval2; 318 319 if (htab->table[idx].used == USED_DELETED) 320 first_deleted = idx; 321 322 ret = _compare_and_overwrite_entry(item, action, retval, htab, 323 flag, hval, idx); 324 if (ret != -1) 325 return ret; 326 327 /* 328 * Second hash function: 329 * as suggested in [Knuth] 330 */ 331 hval2 = 1 + hval % (htab->size - 2); 332 333 do { 334 /* 335 * Because SIZE is prime this guarantees to 336 * step through all available indices. 337 */ 338 if (idx <= hval2) 339 idx = htab->size + idx - hval2; 340 else 341 idx -= hval2; 342 343 /* 344 * If we visited all entries leave the loop 345 * unsuccessfully. 346 */ 347 if (idx == hval) 348 break; 349 350 if (htab->table[idx].used == USED_DELETED 351 && !first_deleted) 352 first_deleted = idx; 353 354 /* If entry is found use it. */ 355 ret = _compare_and_overwrite_entry(item, action, retval, 356 htab, flag, hval, idx); 357 if (ret != -1) 358 return ret; 359 } 360 while (htab->table[idx].used != USED_FREE); 361 } 362 363 /* An empty bucket has been found. */ 364 if (action == ENV_ENTER) { 365 /* 366 * If table is full and another entry should be 367 * entered return with error. 368 */ 369 if (htab->filled == htab->size) { 370 __set_errno(ENOMEM); 371 *retval = NULL; 372 return 0; 373 } 374 375 /* 376 * Create new entry; 377 * create copies of item.key and item.data 378 */ 379 if (first_deleted) 380 idx = first_deleted; 381 382 htab->table[idx].used = hval; 383 htab->table[idx].entry.key = strdup(item.key); 384 htab->table[idx].entry.data = strdup(item.data); 385 if (!htab->table[idx].entry.key || 386 !htab->table[idx].entry.data) { 387 __set_errno(ENOMEM); 388 *retval = NULL; 389 return 0; 390 } 391 392 ++htab->filled; 393 394 /* This is a new entry, so look up a possible callback */ 395 env_callback_init(&htab->table[idx].entry); 396 /* Also look for flags */ 397 env_flags_init(&htab->table[idx].entry); 398 399 /* check for permission */ 400 if (htab->change_ok != NULL && htab->change_ok( 401 &htab->table[idx].entry, item.data, env_op_create, flag)) { 402 debug("change_ok() rejected setting variable " 403 "%s, skipping it!\n", item.key); 404 _hdelete(item.key, htab, &htab->table[idx].entry, idx); 405 __set_errno(EPERM); 406 *retval = NULL; 407 return 0; 408 } 409 410 /* If there is a callback, call it */ 411 if (do_callback(&htab->table[idx].entry, item.key, item.data, 412 env_op_create, flag)) { 413 debug("callback() rejected setting variable " 414 "%s, skipping it!\n", item.key); 415 _hdelete(item.key, htab, &htab->table[idx].entry, idx); 416 __set_errno(EINVAL); 417 *retval = NULL; 418 return 0; 419 } 420 421 /* return new entry */ 422 *retval = &htab->table[idx].entry; 423 return 1; 424 } 425 426 __set_errno(ESRCH); 427 *retval = NULL; 428 return 0; 429} 430 431 432/* 433 * hdelete() 434 */ 435 436/* 437 * The standard implementation of hsearch(3) does not provide any way 438 * to delete any entries from the hash table. We extend the code to 439 * do that. 440 */ 441 442static void _hdelete(const char *key, struct hsearch_data *htab, 443 struct env_entry *ep, int idx) 444{ 445 /* free used entry */ 446 debug("hdelete: DELETING key \"%s\"\n", key); 447 free((void *)ep->key); 448 free(ep->data); 449 ep->flags = 0; 450 htab->table[idx].used = USED_DELETED; 451 452 --htab->filled; 453} 454 455int hdelete_r(const char *key, struct hsearch_data *htab, int flag) 456{ 457 struct env_entry e, *ep; 458 int idx; 459 460 debug("hdelete: DELETE key \"%s\"\n", key); 461 462 e.key = (char *)key; 463 464 idx = hsearch_r(e, ENV_FIND, &ep, htab, 0); 465 if (idx == 0) { 466 __set_errno(ESRCH); 467 return -ENOENT; /* not found */ 468 } 469 470 /* Check for permission */ 471 if (htab->change_ok != NULL && 472 htab->change_ok(ep, NULL, env_op_delete, flag)) { 473 debug("change_ok() rejected deleting variable " 474 "%s, skipping it!\n", key); 475 __set_errno(EPERM); 476 return -EPERM; 477 } 478 479 /* If there is a callback, call it */ 480 if (do_callback(&htab->table[idx].entry, key, NULL, 481 env_op_delete, flag)) { 482 debug("callback() rejected deleting variable " 483 "%s, skipping it!\n", key); 484 __set_errno(EINVAL); 485 return -EINVAL; 486 } 487 488 _hdelete(key, htab, ep, idx); 489 490 return 0; 491} 492 493#if !(defined(CONFIG_SPL_BUILD) && !defined(CONFIG_SPL_SAVEENV)) 494/* 495 * hexport() 496 */ 497 498/* 499 * Export the data stored in the hash table in linearized form. 500 * 501 * Entries are exported as "name=value" strings, separated by an 502 * arbitrary (non-NUL, of course) separator character. This allows to 503 * use this function both when formatting the U-Boot environment for 504 * external storage (using '\0' as separator), but also when using it 505 * for the "printenv" command to print all variables, simply by using 506 * as '\n" as separator. This can also be used for new features like 507 * exporting the environment data as text file, including the option 508 * for later re-import. 509 * 510 * The entries in the result list will be sorted by ascending key 511 * values. 512 * 513 * If the separator character is different from NUL, then any 514 * separator characters and backslash characters in the values will 515 * be escaped by a preceding backslash in output. This is needed for 516 * example to enable multi-line values, especially when the output 517 * shall later be parsed (for example, for re-import). 518 * 519 * There are several options how the result buffer is handled: 520 * 521 * *resp size 522 * ----------- 523 * NULL 0 A string of sufficient length will be allocated. 524 * NULL >0 A string of the size given will be 525 * allocated. An error will be returned if the size is 526 * not sufficient. Any unused bytes in the string will 527 * be '\0'-padded. 528 * !NULL 0 The user-supplied buffer will be used. No length 529 * checking will be performed, i. e. it is assumed that 530 * the buffer size will always be big enough. DANGEROUS. 531 * !NULL >0 The user-supplied buffer will be used. An error will 532 * be returned if the size is not sufficient. Any unused 533 * bytes in the string will be '\0'-padded. 534 */ 535 536static int cmpkey(const void *p1, const void *p2) 537{ 538 struct env_entry *e1 = *(struct env_entry **)p1; 539 struct env_entry *e2 = *(struct env_entry **)p2; 540 541 return (strcmp(e1->key, e2->key)); 542} 543 544static int match_string(int flag, const char *str, const char *pat, void *priv) 545{ 546 switch (flag & H_MATCH_METHOD) { 547 case H_MATCH_IDENT: 548 if (strcmp(str, pat) == 0) 549 return 1; 550 break; 551 case H_MATCH_SUBSTR: 552 if (strstr(str, pat)) 553 return 1; 554 break; 555#ifdef CONFIG_REGEX 556 case H_MATCH_REGEX: 557 { 558 struct slre *slrep = (struct slre *)priv; 559 560 if (slre_match(slrep, str, strlen(str), NULL)) 561 return 1; 562 } 563 break; 564#endif 565 default: 566 printf("## ERROR: unsupported match method: 0x%02x\n", 567 flag & H_MATCH_METHOD); 568 break; 569 } 570 return 0; 571} 572 573static int match_entry(struct env_entry *ep, int flag, int argc, 574 char *const argv[]) 575{ 576 int arg; 577 void *priv = NULL; 578 579 for (arg = 0; arg < argc; ++arg) { 580#ifdef CONFIG_REGEX 581 struct slre slre; 582 583 if (slre_compile(&slre, argv[arg]) == 0) { 584 printf("Error compiling regex: %s\n", slre.err_str); 585 return 0; 586 } 587 588 priv = (void *)&slre; 589#endif 590 if (flag & H_MATCH_KEY) { 591 if (match_string(flag, ep->key, argv[arg], priv)) 592 return 1; 593 } 594 if (flag & H_MATCH_DATA) { 595 if (match_string(flag, ep->data, argv[arg], priv)) 596 return 1; 597 } 598 } 599 return 0; 600} 601 602ssize_t hexport_r(struct hsearch_data *htab, const char sep, int flag, 603 char **resp, size_t size, 604 int argc, char *const argv[]) 605{ 606 struct env_entry *list[htab->size]; 607 char *res, *p; 608 size_t totlen; 609 int i, n; 610 611 /* Test for correct arguments. */ 612 if ((resp == NULL) || (htab == NULL)) { 613 __set_errno(EINVAL); 614 return (-1); 615 } 616 617 debug("EXPORT table = %p, htab.size = %d, htab.filled = %d, size = %lu\n", 618 htab, htab->size, htab->filled, (ulong)size); 619 /* 620 * Pass 1: 621 * search used entries, 622 * save addresses and compute total length 623 */ 624 for (i = 1, n = 0, totlen = 0; i <= htab->size; ++i) { 625 626 if (htab->table[i].used > 0) { 627 struct env_entry *ep = &htab->table[i].entry; 628 int found = match_entry(ep, flag, argc, argv); 629 630 if ((argc > 0) && (found == 0)) 631 continue; 632 633 if ((flag & H_HIDE_DOT) && ep->key[0] == '.') 634 continue; 635 636 list[n++] = ep; 637 638 totlen += strlen(ep->key); 639 640 if (sep == '\0') { 641 totlen += strlen(ep->data); 642 } else { /* check if escapes are needed */ 643 char *s = ep->data; 644 645 while (*s) { 646 ++totlen; 647 /* add room for needed escape chars */ 648 if ((*s == sep) || (*s == '\\')) 649 ++totlen; 650 ++s; 651 } 652 } 653 totlen += 2; /* for '=' and 'sep' char */ 654 } 655 } 656 657#ifdef DEBUG 658 /* Pass 1a: print unsorted list */ 659 printf("Unsorted: n=%d\n", n); 660 for (i = 0; i < n; ++i) { 661 printf("\t%3d: %p ==> %-10s => %s\n", 662 i, list[i], list[i]->key, list[i]->data); 663 } 664#endif 665 666 /* Sort list by keys */ 667 qsort(list, n, sizeof(struct env_entry *), cmpkey); 668 669 /* Check if the user supplied buffer size is sufficient */ 670 if (size) { 671 if (size < totlen + 1) { /* provided buffer too small */ 672 printf("Env export buffer too small: %lu, but need %lu\n", 673 (ulong)size, (ulong)totlen + 1); 674 __set_errno(ENOMEM); 675 return (-1); 676 } 677 } else { 678 size = totlen + 1; 679 } 680 681 /* Check if the user provided a buffer */ 682 if (*resp) { 683 /* yes; clear it */ 684 res = *resp; 685 memset(res, '\0', size); 686 } else { 687 /* no, allocate and clear one */ 688 *resp = res = calloc(1, size); 689 if (res == NULL) { 690 __set_errno(ENOMEM); 691 return (-1); 692 } 693 } 694 /* 695 * Pass 2: 696 * export sorted list of result data 697 */ 698 for (i = 0, p = res; i < n; ++i) { 699 const char *s; 700 701 s = list[i]->key; 702 while (*s) 703 *p++ = *s++; 704 *p++ = '='; 705 706 s = list[i]->data; 707 708 while (*s) { 709 if ((*s == sep) || (*s == '\\')) 710 *p++ = '\\'; /* escape */ 711 *p++ = *s++; 712 } 713 *p++ = sep; 714 } 715 *p = '\0'; /* terminate result */ 716 717 return size; 718} 719#endif 720 721 722/* 723 * himport() 724 */ 725 726/* 727 * Check whether variable 'name' is amongst vars[], 728 * and remove all instances by setting the pointer to NULL 729 */ 730static int drop_var_from_set(const char *name, int nvars, char * vars[]) 731{ 732 int i = 0; 733 int res = 0; 734 735 /* No variables specified means process all of them */ 736 if (nvars == 0) 737 return 1; 738 739 for (i = 0; i < nvars; i++) { 740 if (vars[i] == NULL) 741 continue; 742 /* If we found it, delete all of them */ 743 if (!strcmp(name, vars[i])) { 744 vars[i] = NULL; 745 res = 1; 746 } 747 } 748 if (!res) 749 debug("Skipping non-listed variable %s\n", name); 750 751 return res; 752} 753 754/* 755 * Import linearized data into hash table. 756 * 757 * This is the inverse function to hexport(): it takes a linear list 758 * of "name=value" pairs and creates hash table entries from it. 759 * 760 * Entries without "value", i. e. consisting of only "name" or 761 * "name=", will cause this entry to be deleted from the hash table. 762 * 763 * The "flag" argument can be used to control the behaviour: when the 764 * H_NOCLEAR bit is set, then an existing hash table will kept, i. e. 765 * new data will be added to an existing hash table; otherwise, if no 766 * vars are passed, old data will be discarded and a new hash table 767 * will be created. If vars are passed, passed vars that are not in 768 * the linear list of "name=value" pairs will be removed from the 769 * current hash table. 770 * 771 * The separator character for the "name=value" pairs can be selected, 772 * so we both support importing from externally stored environment 773 * data (separated by NUL characters) and from plain text files 774 * (entries separated by newline characters). 775 * 776 * To allow for nicely formatted text input, leading white space 777 * (sequences of SPACE and TAB chars) is ignored, and entries starting 778 * (after removal of any leading white space) with a '#' character are 779 * considered comments and ignored. 780 * 781 * [NOTE: this means that a variable name cannot start with a '#' 782 * character.] 783 * 784 * When using a non-NUL separator character, backslash is used as 785 * escape character in the value part, allowing for example for 786 * multi-line values. 787 * 788 * In theory, arbitrary separator characters can be used, but only 789 * '\0' and '\n' have really been tested. 790 */ 791 792int himport_r(struct hsearch_data *htab, 793 const char *env, size_t size, const char sep, int flag, 794 int crlf_is_lf, int nvars, char * const vars[]) 795{ 796 char *data, *sp, *dp, *name, *value; 797 char *localvars[nvars]; 798 int i; 799 800 /* Test for correct arguments. */ 801 if (htab == NULL) { 802 __set_errno(EINVAL); 803 return 0; 804 } 805 806 /* we allocate new space to make sure we can write to the array */ 807 if ((data = malloc(size + 1)) == NULL) { 808 debug("himport_r: can't malloc %lu bytes\n", (ulong)size + 1); 809 __set_errno(ENOMEM); 810 return 0; 811 } 812 memcpy(data, env, size); 813 data[size] = '\0'; 814 dp = data; 815 816 /* make a local copy of the list of variables */ 817 if (nvars) 818 memcpy(localvars, vars, sizeof(vars[0]) * nvars); 819 820#if CONFIG_IS_ENABLED(ENV_APPEND) 821 flag |= H_NOCLEAR; 822#endif 823 824 if ((flag & H_NOCLEAR) == 0 && !nvars) { 825 /* Destroy old hash table if one exists */ 826 debug("Destroy Hash Table: %p table = %p\n", htab, 827 htab->table); 828 if (htab->table) 829 hdestroy_r(htab); 830 } 831 832 /* 833 * Create new hash table (if needed). The computation of the hash 834 * table size is based on heuristics: in a sample of some 70+ 835 * existing systems we found an average size of 39+ bytes per entry 836 * in the environment (for the whole key=value pair). Assuming a 837 * size of 8 per entry (= safety factor of ~5) should provide enough 838 * safety margin for any existing environment definitions and still 839 * allow for more than enough dynamic additions. Note that the 840 * "size" argument is supposed to give the maximum environment size 841 * (CONFIG_ENV_SIZE). This heuristics will result in 842 * unreasonably large numbers (and thus memory footprint) for 843 * big flash environments (>8,000 entries for 64 KB 844 * environment size), so we clip it to a reasonable value. 845 * On the other hand we need to add some more entries for free 846 * space when importing very small buffers. Both boundaries can 847 * be overwritten in the board config file if needed. 848 */ 849 850 if (!htab->table) { 851 int nent = CONFIG_ENV_MIN_ENTRIES + size / 8; 852 853 if (nent > CONFIG_ENV_MAX_ENTRIES) 854 nent = CONFIG_ENV_MAX_ENTRIES; 855 856 debug("Create Hash Table: N=%d\n", nent); 857 858 if (hcreate_r(nent, htab) == 0) { 859 free(data); 860 return 0; 861 } 862 } 863 864 if (!size) { 865 free(data); 866 return 1; /* everything OK */ 867 } 868 if(crlf_is_lf) { 869 /* Remove Carriage Returns in front of Line Feeds */ 870 unsigned ignored_crs = 0; 871 for(;dp < data + size && *dp; ++dp) { 872 if(*dp == '\r' && 873 dp < data + size - 1 && *(dp+1) == '\n') 874 ++ignored_crs; 875 else 876 *(dp-ignored_crs) = *dp; 877 } 878 size -= ignored_crs; 879 dp = data; 880 } 881 /* Parse environment; allow for '\0' and 'sep' as separators */ 882 do { 883 struct env_entry e, *rv; 884 885 /* skip leading white space */ 886 while (isblank(*dp)) 887 ++dp; 888 889 /* skip comment lines */ 890 if (*dp == '#') { 891 while (*dp && (*dp != sep)) 892 ++dp; 893 ++dp; 894 continue; 895 } 896 897 /* parse name */ 898 for (name = dp; *dp != '=' && *dp && *dp != sep; ++dp) 899 ; 900 901 /* deal with "name" and "name=" entries (delete var) */ 902 if (*dp == '\0' || *(dp + 1) == '\0' || 903 *dp == sep || *(dp + 1) == sep) { 904 if (*dp == '=') 905 *dp++ = '\0'; 906 *dp++ = '\0'; /* terminate name */ 907 908 debug("DELETE CANDIDATE: \"%s\"\n", name); 909 if (!drop_var_from_set(name, nvars, localvars)) 910 continue; 911 912 if (hdelete_r(name, htab, flag)) 913 debug("DELETE ERROR ##############################\n"); 914 915 continue; 916 } 917 *dp++ = '\0'; /* terminate name */ 918 919 /* parse value; deal with escapes */ 920 for (value = sp = dp; *dp && (*dp != sep); ++dp) { 921 if ((*dp == '\\') && *(dp + 1)) 922 ++dp; 923 *sp++ = *dp; 924 } 925 *sp++ = '\0'; /* terminate value */ 926 ++dp; 927 928 if (*name == 0) { 929 debug("INSERT: unable to use an empty key\n"); 930 __set_errno(EINVAL); 931 free(data); 932 return 0; 933 } 934 935 /* Skip variables which are not supposed to be processed */ 936 if (!drop_var_from_set(name, nvars, localvars)) 937 continue; 938 939 /* enter into hash table */ 940 e.key = name; 941 e.data = value; 942 943 hsearch_r(e, ENV_ENTER, &rv, htab, flag); 944#if !IS_ENABLED(CONFIG_ENV_WRITEABLE_LIST) 945 if (rv == NULL) { 946 printf("himport_r: can't insert \"%s=%s\" into hash table\n", 947 name, value); 948 } 949#endif 950 951 debug("INSERT: table %p, filled %d/%d rv %p ==> name=\"%s\" value=\"%s\"\n", 952 htab, htab->filled, htab->size, 953 rv, name, value); 954 } while ((dp < data + size) && *dp); /* size check needed for text */ 955 /* without '\0' termination */ 956 debug("INSERT: free(data = %p)\n", data); 957 free(data); 958 959 if (flag & H_NOCLEAR) 960 goto end; 961 962 /* process variables which were not considered */ 963 for (i = 0; i < nvars; i++) { 964 if (localvars[i] == NULL) 965 continue; 966 /* 967 * All variables which were not deleted from the variable list 968 * were not present in the imported env 969 * This could mean two things: 970 * a) if the variable was present in current env, we delete it 971 * b) if the variable was not present in current env, we notify 972 * it might be a typo 973 */ 974 if (hdelete_r(localvars[i], htab, flag)) 975 printf("WARNING: '%s' neither in running nor in imported env!\n", localvars[i]); 976 else 977 printf("WARNING: '%s' not in imported env, deleting it!\n", localvars[i]); 978 } 979 980end: 981 debug("INSERT: done\n"); 982 return 1; /* everything OK */ 983} 984 985/* 986 * hwalk_r() 987 */ 988 989/* 990 * Walk all of the entries in the hash, calling the callback for each one. 991 * this allows some generic operation to be performed on each element. 992 */ 993int hwalk_r(struct hsearch_data *htab, int (*callback)(struct env_entry *entry)) 994{ 995 int i; 996 int retval; 997 998 for (i = 1; i <= htab->size; ++i) { 999 if (htab->table[i].used > 0) { 1000 retval = callback(&htab->table[i].entry); 1001 if (retval) 1002 return retval; 1003 } 1004 } 1005 1006 return 0; 1007} 1008