hashtable.c 25 KB

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