setexpr.c 11 KB

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  1. // SPDX-License-Identifier: GPL-2.0+
  2. /*
  3. * Copyright 2008 Freescale Semiconductor, Inc.
  4. * Copyright 2013 Wolfgang Denk <wd@denx.de>
  5. */
  6. /*
  7. * This file provides a shell like 'expr' function to return.
  8. */
  9. #include <common.h>
  10. #include <config.h>
  11. #include <command.h>
  12. #include <env.h>
  13. #include <log.h>
  14. #include <malloc.h>
  15. #include <mapmem.h>
  16. #include <linux/sizes.h>
  17. /**
  18. * struct expr_arg: Holds an argument to an expression
  19. *
  20. * @ival: Integer value (if width is not CMD_DATA_SIZE_STR)
  21. * @sval: String value (if width is CMD_DATA_SIZE_STR)
  22. */
  23. struct expr_arg {
  24. union {
  25. ulong ival;
  26. char *sval;
  27. };
  28. };
  29. static int get_arg(char *s, int w, struct expr_arg *argp)
  30. {
  31. struct expr_arg arg;
  32. /*
  33. * If the parameter starts with a '*' then assume it is a pointer to
  34. * the value we want.
  35. */
  36. if (s[0] == '*') {
  37. ulong *p;
  38. ulong addr;
  39. ulong val;
  40. int len;
  41. char *str;
  42. addr = simple_strtoul(&s[1], NULL, 16);
  43. switch (w) {
  44. case 1:
  45. p = map_sysmem(addr, sizeof(uchar));
  46. val = (ulong)*(uchar *)p;
  47. unmap_sysmem(p);
  48. arg.ival = val;
  49. break;
  50. case 2:
  51. p = map_sysmem(addr, sizeof(ushort));
  52. val = (ulong)*(ushort *)p;
  53. unmap_sysmem(p);
  54. arg.ival = val;
  55. break;
  56. case CMD_DATA_SIZE_STR:
  57. p = map_sysmem(addr, SZ_64K);
  58. /* Maximum string length of 64KB plus terminator */
  59. len = strnlen((char *)p, SZ_64K) + 1;
  60. str = malloc(len);
  61. if (!str) {
  62. printf("Out of memory\n");
  63. return -ENOMEM;
  64. }
  65. memcpy(str, p, len);
  66. str[len - 1] = '\0';
  67. unmap_sysmem(p);
  68. arg.sval = str;
  69. break;
  70. case 4:
  71. p = map_sysmem(addr, sizeof(u32));
  72. val = *(u32 *)p;
  73. unmap_sysmem(p);
  74. arg.ival = val;
  75. break;
  76. default:
  77. p = map_sysmem(addr, sizeof(ulong));
  78. val = *p;
  79. unmap_sysmem(p);
  80. arg.ival = val;
  81. break;
  82. }
  83. } else {
  84. if (w == CMD_DATA_SIZE_STR)
  85. return -EINVAL;
  86. arg.ival = simple_strtoul(s, NULL, 16);
  87. }
  88. *argp = arg;
  89. return 0;
  90. }
  91. #ifdef CONFIG_REGEX
  92. #include <slre.h>
  93. /*
  94. * memstr - Find the first substring in memory
  95. * @s1: The string to be searched
  96. * @s2: The string to search for
  97. *
  98. * Similar to and based on strstr(),
  99. * but strings do not need to be NUL terminated.
  100. */
  101. static char *memstr(const char *s1, int l1, const char *s2, int l2)
  102. {
  103. if (!l2)
  104. return (char *)s1;
  105. while (l1 >= l2) {
  106. l1--;
  107. if (!memcmp(s1, s2, l2))
  108. return (char *)s1;
  109. s1++;
  110. }
  111. return NULL;
  112. }
  113. /**
  114. * substitute() - Substitute part of one string with another
  115. *
  116. * This updates @string so that the first occurrence of @old is replaced with
  117. * @new
  118. *
  119. * @string: String buffer containing string to update at the start
  120. * @slen: Pointer to current string length, updated on success
  121. * @ssize: Size of string buffer
  122. * @old: Old string to find in the buffer (no terminator needed)
  123. * @olen: Length of @old excluding terminator
  124. * @new: New string to replace @old with
  125. * @nlen: Length of @new excluding terminator
  126. * @return pointer to immediately after the copied @new in @string, or NULL if
  127. * no replacement took place
  128. */
  129. static char *substitute(char *string, int *slen, int ssize,
  130. const char *old, int olen, const char *new, int nlen)
  131. {
  132. char *p = memstr(string, *slen, old, olen);
  133. if (p == NULL)
  134. return NULL;
  135. debug("## Match at pos %ld: match len %d, subst len %d\n",
  136. (long)(p - string), olen, nlen);
  137. /* make sure replacement matches */
  138. if (*slen + nlen - olen > ssize) {
  139. printf("## error: substitution buffer overflow\n");
  140. return NULL;
  141. }
  142. /* move tail if needed */
  143. if (olen != nlen) {
  144. int tail, len;
  145. len = (olen > nlen) ? olen : nlen;
  146. tail = ssize - (p + len - string);
  147. debug("## tail len %d\n", tail);
  148. memmove(p + nlen, p + olen, tail);
  149. }
  150. /* insert substitute */
  151. memcpy(p, new, nlen);
  152. *slen += nlen - olen;
  153. return p + nlen;
  154. }
  155. int setexpr_regex_sub(char *data, uint data_size, char *nbuf, uint nbuf_size,
  156. const char *r, const char *s, bool global)
  157. {
  158. struct slre slre;
  159. char *datap = data;
  160. int res, len, nlen, loop;
  161. if (slre_compile(&slre, r) == 0) {
  162. printf("Error compiling regex: %s\n", slre.err_str);
  163. return 1;
  164. }
  165. len = strlen(data);
  166. for (loop = 0;; loop++) {
  167. struct cap caps[slre.num_caps + 2];
  168. const char *old;
  169. char *np;
  170. int i, olen;
  171. (void) memset(caps, 0, sizeof(caps));
  172. res = slre_match(&slre, datap, len - (datap - data), caps);
  173. debug("Result: %d\n", res);
  174. for (i = 0; i <= slre.num_caps; i++) {
  175. if (caps[i].len > 0) {
  176. debug("Substring %d: [%.*s]\n", i,
  177. caps[i].len, caps[i].ptr);
  178. }
  179. }
  180. if (res == 0) {
  181. if (loop == 0) {
  182. printf("%s: No match\n", data);
  183. return 1;
  184. } else {
  185. break;
  186. }
  187. }
  188. debug("## MATCH ## %s\n", data);
  189. if (!s)
  190. return 1;
  191. old = caps[0].ptr;
  192. olen = caps[0].len;
  193. nlen = strlen(s);
  194. if (nlen + 1 >= nbuf_size) {
  195. printf("## error: pattern buffer overflow: have %d, need %d\n",
  196. nbuf_size, nlen + 1);
  197. return 1;
  198. }
  199. strcpy(nbuf, s);
  200. debug("## SUBST(1) ## %s\n", nbuf);
  201. /*
  202. * Handle back references
  203. *
  204. * Support for \0 ... \9, where \0 is the
  205. * whole matched pattern (similar to &).
  206. *
  207. * Implementation is a bit simpleminded as
  208. * backrefs are substituted sequentially, one
  209. * by one. This will lead to somewhat
  210. * unexpected results if the replacement
  211. * strings contain any \N strings then then
  212. * may get substitued, too. We accept this
  213. * restriction for the sake of simplicity.
  214. */
  215. for (i = 0; i < 10; ++i) {
  216. char backref[2] = {
  217. '\\',
  218. '0',
  219. };
  220. if (caps[i].len == 0)
  221. break;
  222. backref[1] += i;
  223. debug("## BACKREF %d: replace \"%.*s\" by \"%.*s\" in \"%s\"\n",
  224. i,
  225. 2, backref,
  226. caps[i].len, caps[i].ptr,
  227. nbuf);
  228. for (np = nbuf;;) {
  229. char *p = memstr(np, nlen, backref, 2);
  230. if (p == NULL)
  231. break;
  232. np = substitute(np, &nlen,
  233. nbuf_size - (np - nbuf),
  234. backref, 2,
  235. caps[i].ptr, caps[i].len);
  236. if (np == NULL)
  237. return 1;
  238. }
  239. }
  240. debug("## SUBST(2) ## %s\n", nbuf);
  241. datap = substitute(datap, &len, data_size - (datap - data),
  242. old, olen, nbuf, nlen);
  243. if (datap == NULL)
  244. return 1;
  245. debug("## REMAINDER: %s\n", datap);
  246. debug("## RESULT: %s\n", data);
  247. if (!global)
  248. break;
  249. }
  250. debug("## FINAL (now env_set()) : %s\n", data);
  251. return 0;
  252. }
  253. #define SLRE_BUFSZ 16384
  254. #define SLRE_PATSZ 4096
  255. /*
  256. * Perform regex operations on a environment variable
  257. *
  258. * Returns 0 if OK, 1 in case of errors.
  259. */
  260. static int regex_sub_var(const char *name, const char *r, const char *s,
  261. const char *t, int global)
  262. {
  263. struct slre slre;
  264. char data[SLRE_BUFSZ];
  265. char nbuf[SLRE_PATSZ];
  266. const char *value;
  267. int len;
  268. int ret;
  269. if (!name)
  270. return 1;
  271. if (slre_compile(&slre, r) == 0) {
  272. printf("Error compiling regex: %s\n", slre.err_str);
  273. return 1;
  274. }
  275. if (!t) {
  276. value = env_get(name);
  277. if (!value) {
  278. printf("## Error: variable \"%s\" not defined\n", name);
  279. return 1;
  280. }
  281. t = value;
  282. }
  283. debug("REGEX on %s=%s\n", name, t);
  284. debug("REGEX=\"%s\", SUBST=\"%s\", GLOBAL=%d\n", r, s ? s : "<NULL>",
  285. global);
  286. len = strlen(t);
  287. if (len + 1 > SLRE_BUFSZ) {
  288. printf("## error: subst buffer overflow: have %d, need %d\n",
  289. SLRE_BUFSZ, len + 1);
  290. return 1;
  291. }
  292. strcpy(data, t);
  293. ret = setexpr_regex_sub(data, SLRE_BUFSZ, nbuf, SLRE_PATSZ, r, s,
  294. global);
  295. if (ret)
  296. return 1;
  297. printf("%s=%s\n", name, data);
  298. return env_set(name, data);
  299. }
  300. #endif
  301. static int do_setexpr(struct cmd_tbl *cmdtp, int flag, int argc,
  302. char *const argv[])
  303. {
  304. struct expr_arg aval, bval;
  305. ulong value;
  306. int ret = 0;
  307. int w;
  308. /*
  309. * We take 3, 5, or 6 arguments:
  310. * 3 : setexpr name value
  311. * 5 : setexpr name val1 op val2
  312. * setexpr name [g]sub r s
  313. * 6 : setexpr name [g]sub r s t
  314. */
  315. /* > 6 already tested by max command args */
  316. if ((argc < 3) || (argc == 4))
  317. return CMD_RET_USAGE;
  318. w = cmd_get_data_size(argv[0], 4);
  319. if (get_arg(argv[2], w, &aval))
  320. return CMD_RET_FAILURE;
  321. /* plain assignment: "setexpr name value" */
  322. if (argc == 3) {
  323. if (w == CMD_DATA_SIZE_STR) {
  324. ret = env_set(argv[1], aval.sval);
  325. free(aval.sval);
  326. } else {
  327. ret = env_set_hex(argv[1], aval.ival);
  328. }
  329. return ret;
  330. }
  331. /* 5 or 6 args (6 args only with [g]sub) */
  332. #ifdef CONFIG_REGEX
  333. /*
  334. * rexep handling: "setexpr name [g]sub r s [t]"
  335. * with 5 args, "t" will be NULL
  336. */
  337. if (strcmp(argv[2], "gsub") == 0)
  338. return regex_sub_var(argv[1], argv[3], argv[4], argv[5], 1);
  339. if (strcmp(argv[2], "sub") == 0)
  340. return regex_sub_var(argv[1], argv[3], argv[4], argv[5], 0);
  341. #endif
  342. /* standard operators: "setexpr name val1 op val2" */
  343. if (argc != 5)
  344. return CMD_RET_USAGE;
  345. if (strlen(argv[3]) != 1)
  346. return CMD_RET_USAGE;
  347. if (get_arg(argv[4], w, &bval)) {
  348. if (w == CMD_DATA_SIZE_STR)
  349. free(aval.sval);
  350. return CMD_RET_FAILURE;
  351. }
  352. if (w == CMD_DATA_SIZE_STR) {
  353. int len;
  354. char *str;
  355. switch (argv[3][0]) {
  356. case '+':
  357. len = strlen(aval.sval) + strlen(bval.sval) + 1;
  358. str = malloc(len);
  359. if (!str) {
  360. printf("Out of memory\n");
  361. ret = CMD_RET_FAILURE;
  362. } else {
  363. /* These were copied out and checked earlier */
  364. strcpy(str, aval.sval);
  365. strcat(str, bval.sval);
  366. ret = env_set(argv[1], str);
  367. if (ret)
  368. printf("Could not set var\n");
  369. free(str);
  370. }
  371. break;
  372. default:
  373. printf("invalid op\n");
  374. ret = 1;
  375. }
  376. } else {
  377. ulong a = aval.ival;
  378. ulong b = bval.ival;
  379. switch (argv[3][0]) {
  380. case '|':
  381. value = a | b;
  382. break;
  383. case '&':
  384. value = a & b;
  385. break;
  386. case '+':
  387. value = a + b;
  388. break;
  389. case '^':
  390. value = a ^ b;
  391. break;
  392. case '-':
  393. value = a - b;
  394. break;
  395. case '*':
  396. value = a * b;
  397. break;
  398. case '/':
  399. value = a / b;
  400. break;
  401. case '%':
  402. value = a % b;
  403. break;
  404. default:
  405. printf("invalid op\n");
  406. return 1;
  407. }
  408. env_set_hex(argv[1], value);
  409. }
  410. if (w == CMD_DATA_SIZE_STR) {
  411. free(aval.sval);
  412. free(bval.sval);
  413. }
  414. return ret;
  415. }
  416. U_BOOT_CMD(
  417. setexpr, 6, 0, do_setexpr,
  418. "set environment variable as the result of eval expression",
  419. "[.b, .w, .l, .s] name [*]value1 <op> [*]value2\n"
  420. " - set environment variable 'name' to the result of the evaluated\n"
  421. " expression specified by <op>. <op> can be &, |, ^, +, -, *, /, %\n"
  422. " (for strings only + is supported)\n"
  423. " size argument is only meaningful if value1 and/or value2 are\n"
  424. " memory addresses (*)\n"
  425. "setexpr[.b, .w, .l] name [*]value\n"
  426. " - load a value into a variable"
  427. #ifdef CONFIG_REGEX
  428. "\n"
  429. "setexpr name gsub r s [t]\n"
  430. " - For each substring matching the regular expression <r> in the\n"
  431. " string <t>, substitute the string <s>. The result is\n"
  432. " assigned to <name>. If <t> is not supplied, use the old\n"
  433. " value of <name>\n"
  434. "setexpr name sub r s [t]\n"
  435. " - Just like gsub(), but replace only the first matching substring"
  436. #endif
  437. );