lib537.c 14 KB

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  1. /***************************************************************************
  2. * _ _ ____ _
  3. * Project ___| | | | _ \| |
  4. * / __| | | | |_) | |
  5. * | (__| |_| | _ <| |___
  6. * \___|\___/|_| \_\_____|
  7. *
  8. * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
  9. *
  10. * This software is licensed as described in the file COPYING, which
  11. * you should have received as part of this distribution. The terms
  12. * are also available at https://curl.se/docs/copyright.html.
  13. *
  14. * You may opt to use, copy, modify, merge, publish, distribute and/or sell
  15. * copies of the Software, and permit persons to whom the Software is
  16. * furnished to do so, under the terms of the COPYING file.
  17. *
  18. * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  19. * KIND, either express or implied.
  20. *
  21. * SPDX-License-Identifier: curl
  22. *
  23. ***************************************************************************/
  24. #include "test.h"
  25. #ifdef HAVE_SYS_RESOURCE_H
  26. #include <sys/resource.h>
  27. #endif
  28. #ifdef HAVE_FCNTL_H
  29. #include <fcntl.h>
  30. #endif
  31. #include <limits.h>
  32. #include "warnless.h"
  33. #include "memdebug.h"
  34. #if !defined(HAVE_POLL_FINE) && \
  35. !defined(USE_WINSOCK) && \
  36. !defined(FD_SETSIZE)
  37. #error "this test requires FD_SETSIZE"
  38. #endif
  39. #define SAFETY_MARGIN (11)
  40. #if defined(_WIN32) || defined(MSDOS)
  41. #define DEV_NULL "NUL"
  42. #else
  43. #define DEV_NULL "/dev/null"
  44. #endif
  45. #if defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT)
  46. static int *fd = NULL;
  47. static struct rlimit num_open;
  48. static char msgbuff[256];
  49. static void store_errmsg(const char *msg, int err)
  50. {
  51. if(!err)
  52. msnprintf(msgbuff, sizeof(msgbuff), "%s", msg);
  53. else
  54. msnprintf(msgbuff, sizeof(msgbuff), "%s, errno %d, %s", msg,
  55. err, strerror(err));
  56. }
  57. static void close_file_descriptors(void)
  58. {
  59. for(num_open.rlim_cur = 0;
  60. num_open.rlim_cur < num_open.rlim_max;
  61. num_open.rlim_cur++)
  62. if(fd[num_open.rlim_cur] > 0)
  63. close(fd[num_open.rlim_cur]);
  64. free(fd);
  65. fd = NULL;
  66. }
  67. static int fopen_works(void)
  68. {
  69. FILE *fpa[3];
  70. int i;
  71. int ret = 1;
  72. for(i = 0; i < 3; i++) {
  73. fpa[i] = NULL;
  74. }
  75. for(i = 0; i < 3; i++) {
  76. fpa[i] = fopen(DEV_NULL, FOPEN_READTEXT);
  77. if(!fpa[i]) {
  78. store_errmsg("fopen failed", errno);
  79. fprintf(stderr, "%s\n", msgbuff);
  80. ret = 0;
  81. break;
  82. }
  83. }
  84. for(i = 0; i < 3; i++) {
  85. if(fpa[i])
  86. fclose(fpa[i]);
  87. }
  88. return ret;
  89. }
  90. static void rlim2str(char *buf, size_t len, rlim_t val)
  91. {
  92. #ifdef RLIM_INFINITY
  93. if(val == RLIM_INFINITY) {
  94. msnprintf(buf, len, "INFINITY");
  95. return;
  96. }
  97. #endif
  98. #ifdef HAVE_LONGLONG
  99. if(sizeof(rlim_t) > sizeof(long))
  100. msnprintf(buf, len, "%llu", (unsigned long long)val);
  101. else
  102. #endif
  103. {
  104. if(sizeof(rlim_t) < sizeof(long))
  105. msnprintf(buf, len, "%u", (unsigned int)val);
  106. else
  107. msnprintf(buf, len, "%lu", (unsigned long)val);
  108. }
  109. }
  110. static int rlimit(int keep_open)
  111. {
  112. int *tmpfd;
  113. rlim_t nitems, i;
  114. int *memchunk = NULL;
  115. struct rlimit rl;
  116. char strbuff[256];
  117. char strbuff1[81];
  118. /* get initial open file limits */
  119. if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
  120. store_errmsg("getrlimit() failed", errno);
  121. fprintf(stderr, "%s\n", msgbuff);
  122. return -1;
  123. }
  124. /* show initial open file limits */
  125. rlim2str(strbuff, sizeof(strbuff), rl.rlim_cur);
  126. fprintf(stderr, "initial soft limit: %s\n", strbuff);
  127. rlim2str(strbuff, sizeof(strbuff), rl.rlim_max);
  128. fprintf(stderr, "initial hard limit: %s\n", strbuff);
  129. /*
  130. * if soft limit and hard limit are different we ask the
  131. * system to raise soft limit all the way up to the hard
  132. * limit. Due to some other system limit the soft limit
  133. * might not be raised up to the hard limit. So from this
  134. * point the resulting soft limit is our limit. Trying to
  135. * open more than soft limit file descriptors will fail.
  136. */
  137. if(rl.rlim_cur != rl.rlim_max) {
  138. #ifdef OPEN_MAX
  139. if((rl.rlim_cur > 0) &&
  140. (rl.rlim_cur < OPEN_MAX)) {
  141. fprintf(stderr, "raising soft limit up to OPEN_MAX\n");
  142. rl.rlim_cur = OPEN_MAX;
  143. if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
  144. /* on failure don't abort just issue a warning */
  145. store_errmsg("setrlimit() failed", errno);
  146. fprintf(stderr, "%s\n", msgbuff);
  147. msgbuff[0] = '\0';
  148. }
  149. }
  150. #endif
  151. fprintf(stderr, "raising soft limit up to hard limit\n");
  152. rl.rlim_cur = rl.rlim_max;
  153. if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
  154. /* on failure don't abort just issue a warning */
  155. store_errmsg("setrlimit() failed", errno);
  156. fprintf(stderr, "%s\n", msgbuff);
  157. msgbuff[0] = '\0';
  158. }
  159. /* get current open file limits */
  160. if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
  161. store_errmsg("getrlimit() failed", errno);
  162. fprintf(stderr, "%s\n", msgbuff);
  163. return -3;
  164. }
  165. /* show current open file limits */
  166. rlim2str(strbuff, sizeof(strbuff), rl.rlim_cur);
  167. fprintf(stderr, "current soft limit: %s\n", strbuff);
  168. rlim2str(strbuff, sizeof(strbuff), rl.rlim_max);
  169. fprintf(stderr, "current hard limit: %s\n", strbuff);
  170. } /* (rl.rlim_cur != rl.rlim_max) */
  171. /*
  172. * test 537 is all about testing libcurl functionality
  173. * when the system has nearly exhausted the number of
  174. * available file descriptors. Test 537 will try to run
  175. * with a very small number of file descriptors available.
  176. * This implies that any file descriptor which is open
  177. * when the test runs will have a number in the high range
  178. * of whatever the system supports.
  179. */
  180. /*
  181. * reserve a chunk of memory before opening file descriptors to
  182. * avoid a low memory condition once the file descriptors are
  183. * open. System conditions that could make the test fail should
  184. * be addressed in the precheck phase. This chunk of memory shall
  185. * be always free()ed before exiting the rlimit() function so
  186. * that it becomes available to the test.
  187. */
  188. for(nitems = i = 1; nitems <= i; i *= 2)
  189. nitems = i;
  190. if(nitems > 0x7fff)
  191. nitems = 0x40000;
  192. do {
  193. num_open.rlim_max = sizeof(*memchunk) * nitems;
  194. rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
  195. fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
  196. memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
  197. if(!memchunk) {
  198. fprintf(stderr, "memchunk, malloc() failed\n");
  199. nitems /= 2;
  200. }
  201. } while(nitems && !memchunk);
  202. if(!memchunk) {
  203. store_errmsg("memchunk, malloc() failed", errno);
  204. fprintf(stderr, "%s\n", msgbuff);
  205. return -4;
  206. }
  207. /* initialize it to fight lazy allocation */
  208. fprintf(stderr, "initializing memchunk array\n");
  209. for(i = 0; i < nitems; i++)
  210. memchunk[i] = -1;
  211. /* set the number of file descriptors we will try to open */
  212. #ifdef RLIM_INFINITY
  213. if((rl.rlim_cur > 0) && (rl.rlim_cur != RLIM_INFINITY)) {
  214. #else
  215. if(rl.rlim_cur > 0) {
  216. #endif
  217. /* soft limit minus SAFETY_MARGIN */
  218. num_open.rlim_max = rl.rlim_cur - SAFETY_MARGIN;
  219. }
  220. else {
  221. /* a huge number of file descriptors */
  222. for(nitems = i = 1; nitems <= i; i *= 2)
  223. nitems = i;
  224. if(nitems > 0x7fff)
  225. nitems = 0x40000;
  226. num_open.rlim_max = nitems;
  227. }
  228. /* verify that we won't overflow size_t in malloc() */
  229. if((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*fd)) {
  230. rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_max);
  231. msnprintf(strbuff, sizeof(strbuff), "unable to allocate an array for %s "
  232. "file descriptors, would overflow size_t", strbuff1);
  233. store_errmsg(strbuff, 0);
  234. fprintf(stderr, "%s\n", msgbuff);
  235. free(memchunk);
  236. return -5;
  237. }
  238. /* allocate array for file descriptors */
  239. do {
  240. rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
  241. fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
  242. fd = malloc(sizeof(*fd) * (size_t)(num_open.rlim_max));
  243. if(!fd) {
  244. fprintf(stderr, "fd, malloc() failed\n");
  245. num_open.rlim_max /= 2;
  246. }
  247. } while(num_open.rlim_max && !fd);
  248. if(!fd) {
  249. store_errmsg("fd, malloc() failed", errno);
  250. fprintf(stderr, "%s\n", msgbuff);
  251. free(memchunk);
  252. return -6;
  253. }
  254. /* initialize it to fight lazy allocation */
  255. fprintf(stderr, "initializing fd array\n");
  256. for(num_open.rlim_cur = 0;
  257. num_open.rlim_cur < num_open.rlim_max;
  258. num_open.rlim_cur++)
  259. fd[num_open.rlim_cur] = -1;
  260. rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
  261. fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
  262. /* open a dummy descriptor */
  263. fd[0] = open(DEV_NULL, O_RDONLY);
  264. if(fd[0] < 0) {
  265. msnprintf(strbuff, sizeof(strbuff), "opening of %s failed", DEV_NULL);
  266. store_errmsg(strbuff, errno);
  267. fprintf(stderr, "%s\n", msgbuff);
  268. free(fd);
  269. fd = NULL;
  270. free(memchunk);
  271. return -7;
  272. }
  273. /* create a bunch of file descriptors */
  274. for(num_open.rlim_cur = 1;
  275. num_open.rlim_cur < num_open.rlim_max;
  276. num_open.rlim_cur++) {
  277. fd[num_open.rlim_cur] = dup(fd[0]);
  278. if(fd[num_open.rlim_cur] < 0) {
  279. fd[num_open.rlim_cur] = -1;
  280. rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
  281. msnprintf(strbuff, sizeof(strbuff), "dup() attempt %s failed", strbuff1);
  282. fprintf(stderr, "%s\n", strbuff);
  283. rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
  284. msnprintf(strbuff, sizeof(strbuff), "fds system limit seems close to %s",
  285. strbuff1);
  286. fprintf(stderr, "%s\n", strbuff);
  287. num_open.rlim_max = num_open.rlim_cur - SAFETY_MARGIN;
  288. num_open.rlim_cur -= num_open.rlim_max;
  289. rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
  290. msnprintf(strbuff, sizeof(strbuff), "closing %s file descriptors",
  291. strbuff1);
  292. fprintf(stderr, "%s\n", strbuff);
  293. for(num_open.rlim_cur = num_open.rlim_max;
  294. fd[num_open.rlim_cur] >= 0;
  295. num_open.rlim_cur++) {
  296. close(fd[num_open.rlim_cur]);
  297. fd[num_open.rlim_cur] = -1;
  298. }
  299. rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
  300. fprintf(stderr, "shrinking array for %s file descriptors\n", strbuff);
  301. /* we don't care if we can't shrink it */
  302. tmpfd = realloc(fd, sizeof(*fd) * (size_t)(num_open.rlim_max));
  303. if(tmpfd) {
  304. fd = tmpfd;
  305. tmpfd = NULL;
  306. }
  307. break;
  308. }
  309. }
  310. rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
  311. fprintf(stderr, "%s file descriptors open\n", strbuff);
  312. #if !defined(HAVE_POLL_FINE) && !defined(USE_WINSOCK)
  313. /*
  314. * when using select() instead of poll() we cannot test
  315. * libcurl functionality with a socket number equal or
  316. * greater than FD_SETSIZE. In any case, macro VERIFY_SOCK
  317. * in lib/select.c enforces this check and protects libcurl
  318. * from a possible crash. The effect of this protection
  319. * is that test 537 will always fail, since the actual
  320. * call to select() never takes place. We skip test 537
  321. * with an indication that select limit would be exceeded.
  322. */
  323. num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
  324. if(num_open.rlim_max > num_open.rlim_cur) {
  325. msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
  326. FD_SETSIZE);
  327. store_errmsg(strbuff, 0);
  328. fprintf(stderr, "%s\n", msgbuff);
  329. close_file_descriptors();
  330. free(memchunk);
  331. return -8;
  332. }
  333. num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
  334. for(rl.rlim_cur = 0;
  335. rl.rlim_cur < num_open.rlim_max;
  336. rl.rlim_cur++) {
  337. if((fd[rl.rlim_cur] > 0) &&
  338. ((unsigned int)fd[rl.rlim_cur] > num_open.rlim_cur)) {
  339. msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
  340. FD_SETSIZE);
  341. store_errmsg(strbuff, 0);
  342. fprintf(stderr, "%s\n", msgbuff);
  343. close_file_descriptors();
  344. free(memchunk);
  345. return -9;
  346. }
  347. }
  348. #endif /* using a FD_SETSIZE bound select() */
  349. /*
  350. * Old or 'backwards compatible' implementations of stdio do not allow
  351. * handling of streams with an underlying file descriptor number greater
  352. * than 255, even when allowing high numbered file descriptors for sockets.
  353. * At this point we have a big number of file descriptors which have been
  354. * opened using dup(), so lets test the stdio implementation and discover
  355. * if it is capable of fopen()ing some additional files.
  356. */
  357. if(!fopen_works()) {
  358. rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_max);
  359. msnprintf(strbuff, sizeof(strbuff), "fopen fails with %s fds open",
  360. strbuff1);
  361. fprintf(stderr, "%s\n", msgbuff);
  362. msnprintf(strbuff, sizeof(strbuff), "fopen fails with lots of fds open");
  363. store_errmsg(strbuff, 0);
  364. close_file_descriptors();
  365. free(memchunk);
  366. return -10;
  367. }
  368. /* free the chunk of memory we were reserving so that it
  369. becomes available to the test */
  370. free(memchunk);
  371. /* close file descriptors unless instructed to keep them */
  372. if(!keep_open) {
  373. close_file_descriptors();
  374. }
  375. return 0;
  376. }
  377. CURLcode test(char *URL)
  378. {
  379. CURLcode res;
  380. CURL *curl;
  381. if(!strcmp(URL, "check")) {
  382. /* used by the test script to ask if we can run this test or not */
  383. if(rlimit(FALSE)) {
  384. fprintf(stdout, "rlimit problem: %s\n", msgbuff);
  385. return (CURLcode)1;
  386. }
  387. return CURLE_OK; /* sure, run this! */
  388. }
  389. if(rlimit(TRUE)) {
  390. /* failure */
  391. return TEST_ERR_MAJOR_BAD;
  392. }
  393. /* run the test with the bunch of open file descriptors
  394. and close them all once the test is over */
  395. if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
  396. fprintf(stderr, "curl_global_init() failed\n");
  397. close_file_descriptors();
  398. return TEST_ERR_MAJOR_BAD;
  399. }
  400. curl = curl_easy_init();
  401. if(!curl) {
  402. fprintf(stderr, "curl_easy_init() failed\n");
  403. close_file_descriptors();
  404. curl_global_cleanup();
  405. return TEST_ERR_MAJOR_BAD;
  406. }
  407. test_setopt(curl, CURLOPT_URL, URL);
  408. test_setopt(curl, CURLOPT_HEADER, 1L);
  409. res = curl_easy_perform(curl);
  410. test_cleanup:
  411. close_file_descriptors();
  412. curl_easy_cleanup(curl);
  413. curl_global_cleanup();
  414. return res;
  415. }
  416. #else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
  417. CURLcode test(char *URL)
  418. {
  419. (void)URL;
  420. printf("system lacks necessary system function(s)");
  421. return (CURLcode)1; /* skip test */
  422. }
  423. #endif /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */