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