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