avb_util.c 8.9 KB

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  1. // SPDX-License-Identifier: MIT
  2. /*
  3. * Copyright (C) 2016 The Android Open Source Project
  4. */
  5. #include "avb_util.h"
  6. #include <stdarg.h>
  7. uint32_t avb_be32toh(uint32_t in) {
  8. uint8_t* d = (uint8_t*)&in;
  9. uint32_t ret;
  10. ret = ((uint32_t)d[0]) << 24;
  11. ret |= ((uint32_t)d[1]) << 16;
  12. ret |= ((uint32_t)d[2]) << 8;
  13. ret |= ((uint32_t)d[3]);
  14. return ret;
  15. }
  16. uint64_t avb_be64toh(uint64_t in) {
  17. uint8_t* d = (uint8_t*)&in;
  18. uint64_t ret;
  19. ret = ((uint64_t)d[0]) << 56;
  20. ret |= ((uint64_t)d[1]) << 48;
  21. ret |= ((uint64_t)d[2]) << 40;
  22. ret |= ((uint64_t)d[3]) << 32;
  23. ret |= ((uint64_t)d[4]) << 24;
  24. ret |= ((uint64_t)d[5]) << 16;
  25. ret |= ((uint64_t)d[6]) << 8;
  26. ret |= ((uint64_t)d[7]);
  27. return ret;
  28. }
  29. /* Converts a 32-bit unsigned integer from host to big-endian byte order. */
  30. uint32_t avb_htobe32(uint32_t in) {
  31. union {
  32. uint32_t word;
  33. uint8_t bytes[4];
  34. } ret;
  35. ret.bytes[0] = (in >> 24) & 0xff;
  36. ret.bytes[1] = (in >> 16) & 0xff;
  37. ret.bytes[2] = (in >> 8) & 0xff;
  38. ret.bytes[3] = in & 0xff;
  39. return ret.word;
  40. }
  41. /* Converts a 64-bit unsigned integer from host to big-endian byte order. */
  42. uint64_t avb_htobe64(uint64_t in) {
  43. union {
  44. uint64_t word;
  45. uint8_t bytes[8];
  46. } ret;
  47. ret.bytes[0] = (in >> 56) & 0xff;
  48. ret.bytes[1] = (in >> 48) & 0xff;
  49. ret.bytes[2] = (in >> 40) & 0xff;
  50. ret.bytes[3] = (in >> 32) & 0xff;
  51. ret.bytes[4] = (in >> 24) & 0xff;
  52. ret.bytes[5] = (in >> 16) & 0xff;
  53. ret.bytes[6] = (in >> 8) & 0xff;
  54. ret.bytes[7] = in & 0xff;
  55. return ret.word;
  56. }
  57. int avb_safe_memcmp(const void* s1, const void* s2, size_t n) {
  58. const unsigned char* us1 = s1;
  59. const unsigned char* us2 = s2;
  60. int result = 0;
  61. if (0 == n) {
  62. return 0;
  63. }
  64. /*
  65. * Code snippet without data-dependent branch due to Nate Lawson
  66. * (nate@root.org) of Root Labs.
  67. */
  68. while (n--) {
  69. result |= *us1++ ^ *us2++;
  70. }
  71. return result != 0;
  72. }
  73. bool avb_safe_add_to(uint64_t* value, uint64_t value_to_add) {
  74. uint64_t original_value;
  75. avb_assert(value != NULL);
  76. original_value = *value;
  77. *value += value_to_add;
  78. if (*value < original_value) {
  79. avb_error("Overflow when adding values.\n");
  80. return false;
  81. }
  82. return true;
  83. }
  84. bool avb_safe_add(uint64_t* out_result, uint64_t a, uint64_t b) {
  85. uint64_t dummy;
  86. if (out_result == NULL) {
  87. out_result = &dummy;
  88. }
  89. *out_result = a;
  90. return avb_safe_add_to(out_result, b);
  91. }
  92. bool avb_validate_utf8(const uint8_t* data, size_t num_bytes) {
  93. size_t n;
  94. unsigned int num_cc;
  95. for (n = 0, num_cc = 0; n < num_bytes; n++) {
  96. uint8_t c = data[n];
  97. if (num_cc > 0) {
  98. if ((c & (0x80 | 0x40)) == 0x80) {
  99. /* 10xx xxxx */
  100. } else {
  101. goto fail;
  102. }
  103. num_cc--;
  104. } else {
  105. if (c < 0x80) {
  106. num_cc = 0;
  107. } else if ((c & (0x80 | 0x40 | 0x20)) == (0x80 | 0x40)) {
  108. /* 110x xxxx */
  109. num_cc = 1;
  110. } else if ((c & (0x80 | 0x40 | 0x20 | 0x10)) == (0x80 | 0x40 | 0x20)) {
  111. /* 1110 xxxx */
  112. num_cc = 2;
  113. } else if ((c & (0x80 | 0x40 | 0x20 | 0x10 | 0x08)) ==
  114. (0x80 | 0x40 | 0x20 | 0x10)) {
  115. /* 1111 0xxx */
  116. num_cc = 3;
  117. } else {
  118. goto fail;
  119. }
  120. }
  121. }
  122. if (num_cc != 0) {
  123. goto fail;
  124. }
  125. return true;
  126. fail:
  127. return false;
  128. }
  129. bool avb_str_concat(char* buf,
  130. size_t buf_size,
  131. const char* str1,
  132. size_t str1_len,
  133. const char* str2,
  134. size_t str2_len) {
  135. uint64_t combined_len;
  136. if (!avb_safe_add(&combined_len, str1_len, str2_len)) {
  137. avb_error("Overflow when adding string sizes.\n");
  138. return false;
  139. }
  140. if (combined_len > buf_size - 1) {
  141. avb_error("Insufficient buffer space.\n");
  142. return false;
  143. }
  144. avb_memcpy(buf, str1, str1_len);
  145. avb_memcpy(buf + str1_len, str2, str2_len);
  146. buf[combined_len] = '\0';
  147. return true;
  148. }
  149. void* avb_malloc(size_t size) {
  150. void* ret = avb_malloc_(size);
  151. if (ret == NULL) {
  152. avb_error("Failed to allocate memory.\n");
  153. return NULL;
  154. }
  155. return ret;
  156. }
  157. void* avb_calloc(size_t size) {
  158. void* ret = avb_malloc(size);
  159. if (ret == NULL) {
  160. return NULL;
  161. }
  162. avb_memset(ret, '\0', size);
  163. return ret;
  164. }
  165. char* avb_strdup(const char* str) {
  166. size_t len = avb_strlen(str);
  167. char* ret = avb_malloc(len + 1);
  168. if (ret == NULL) {
  169. return NULL;
  170. }
  171. avb_memcpy(ret, str, len);
  172. ret[len] = '\0';
  173. return ret;
  174. }
  175. const char* avb_strstr(const char* haystack, const char* needle) {
  176. size_t n, m;
  177. /* Look through |haystack| and check if the first character of
  178. * |needle| matches. If so, check the rest of |needle|.
  179. */
  180. for (n = 0; haystack[n] != '\0'; n++) {
  181. if (haystack[n] != needle[0]) {
  182. continue;
  183. }
  184. for (m = 1;; m++) {
  185. if (needle[m] == '\0') {
  186. return haystack + n;
  187. }
  188. if (haystack[n + m] != needle[m]) {
  189. break;
  190. }
  191. }
  192. }
  193. return NULL;
  194. }
  195. const char* avb_strv_find_str(const char* const* strings,
  196. const char* str,
  197. size_t str_size) {
  198. size_t n;
  199. for (n = 0; strings[n] != NULL; n++) {
  200. if (avb_strlen(strings[n]) == str_size &&
  201. avb_memcmp(strings[n], str, str_size) == 0) {
  202. return strings[n];
  203. }
  204. }
  205. return NULL;
  206. }
  207. char* avb_replace(const char* str, const char* search, const char* replace) {
  208. char* ret = NULL;
  209. size_t ret_len = 0;
  210. size_t search_len, replace_len;
  211. const char* str_after_last_replace;
  212. search_len = avb_strlen(search);
  213. replace_len = avb_strlen(replace);
  214. str_after_last_replace = str;
  215. while (*str != '\0') {
  216. const char* s;
  217. size_t num_before;
  218. size_t num_new;
  219. s = avb_strstr(str, search);
  220. if (s == NULL) {
  221. break;
  222. }
  223. num_before = s - str;
  224. if (ret == NULL) {
  225. num_new = num_before + replace_len + 1;
  226. ret = avb_malloc(num_new);
  227. if (ret == NULL) {
  228. goto out;
  229. }
  230. avb_memcpy(ret, str, num_before);
  231. avb_memcpy(ret + num_before, replace, replace_len);
  232. ret[num_new - 1] = '\0';
  233. ret_len = num_new - 1;
  234. } else {
  235. char* new_str;
  236. num_new = ret_len + num_before + replace_len + 1;
  237. new_str = avb_malloc(num_new);
  238. if (new_str == NULL) {
  239. goto out;
  240. }
  241. avb_memcpy(new_str, ret, ret_len);
  242. avb_memcpy(new_str + ret_len, str, num_before);
  243. avb_memcpy(new_str + ret_len + num_before, replace, replace_len);
  244. new_str[num_new - 1] = '\0';
  245. avb_free(ret);
  246. ret = new_str;
  247. ret_len = num_new - 1;
  248. }
  249. str = s + search_len;
  250. str_after_last_replace = str;
  251. }
  252. if (ret == NULL) {
  253. ret = avb_strdup(str_after_last_replace);
  254. if (ret == NULL) {
  255. goto out;
  256. }
  257. } else {
  258. size_t num_remaining = avb_strlen(str_after_last_replace);
  259. size_t num_new = ret_len + num_remaining + 1;
  260. char* new_str = avb_malloc(num_new);
  261. if (new_str == NULL) {
  262. goto out;
  263. }
  264. avb_memcpy(new_str, ret, ret_len);
  265. avb_memcpy(new_str + ret_len, str_after_last_replace, num_remaining);
  266. new_str[num_new - 1] = '\0';
  267. avb_free(ret);
  268. ret = new_str;
  269. ret_len = num_new - 1;
  270. }
  271. out:
  272. return ret;
  273. }
  274. /* We only support a limited amount of strings in avb_strdupv(). */
  275. #define AVB_STRDUPV_MAX_NUM_STRINGS 32
  276. char* avb_strdupv(const char* str, ...) {
  277. va_list ap;
  278. const char* strings[AVB_STRDUPV_MAX_NUM_STRINGS];
  279. size_t lengths[AVB_STRDUPV_MAX_NUM_STRINGS];
  280. size_t num_strings, n;
  281. uint64_t total_length;
  282. char *ret = NULL, *dest;
  283. num_strings = 0;
  284. total_length = 0;
  285. va_start(ap, str);
  286. do {
  287. size_t str_len = avb_strlen(str);
  288. strings[num_strings] = str;
  289. lengths[num_strings] = str_len;
  290. if (!avb_safe_add_to(&total_length, str_len)) {
  291. avb_fatal("Overflow while determining total length.\n");
  292. break;
  293. }
  294. num_strings++;
  295. if (num_strings == AVB_STRDUPV_MAX_NUM_STRINGS) {
  296. avb_fatal("Too many strings passed.\n");
  297. break;
  298. }
  299. str = va_arg(ap, const char*);
  300. } while (str != NULL);
  301. va_end(ap);
  302. ret = avb_malloc(total_length + 1);
  303. if (ret == NULL) {
  304. goto out;
  305. }
  306. dest = ret;
  307. for (n = 0; n < num_strings; n++) {
  308. avb_memcpy(dest, strings[n], lengths[n]);
  309. dest += lengths[n];
  310. }
  311. *dest = '\0';
  312. avb_assert(dest == ret + total_length);
  313. out:
  314. return ret;
  315. }
  316. const char* avb_basename(const char* str) {
  317. int64_t n;
  318. size_t len;
  319. len = avb_strlen(str);
  320. if (len >= 2) {
  321. for (n = len - 2; n >= 0; n--) {
  322. if (str[n] == '/') {
  323. return str + n + 1;
  324. }
  325. }
  326. }
  327. return str;
  328. }
  329. void avb_uppercase(char* str) {
  330. size_t i;
  331. for (i = 0; str[i] != '\0'; ++i) {
  332. if (str[i] <= 0x7A && str[i] >= 0x61) {
  333. str[i] -= 0x20;
  334. }
  335. }
  336. }
  337. char* avb_bin2hex(const uint8_t* data, size_t data_len) {
  338. const char hex_digits[17] = "0123456789abcdef";
  339. char* hex_data;
  340. size_t n;
  341. hex_data = avb_malloc(data_len * 2 + 1);
  342. if (hex_data == NULL) {
  343. return NULL;
  344. }
  345. for (n = 0; n < data_len; n++) {
  346. hex_data[n * 2] = hex_digits[data[n] >> 4];
  347. hex_data[n * 2 + 1] = hex_digits[data[n] & 0x0f];
  348. }
  349. hex_data[n * 2] = '\0';
  350. return hex_data;
  351. }