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
26 #ifdef HAVE_SYS_RESOURCE_H
27 #include <sys/resource.h>
28 #endif
29 #ifdef HAVE_FCNTL_H
30 #include <fcntl.h>
31 #endif
32 #include <limits.h>
33
34 #include "warnless.h"
35 #include "memdebug.h"
36
37 #if !defined(HAVE_POLL) && !defined(USE_WINSOCK) && !defined(FD_SETSIZE)
38 #error "this test requires FD_SETSIZE"
39 #endif
40
41 #define SAFETY_MARGIN (11)
42
43 #if defined(_WIN32) || defined(MSDOS)
44 #define DEV_NULL "NUL"
45 #else
46 #define DEV_NULL "/dev/null"
47 #endif
48
49 #if defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT)
50
51 static int *testfd = NULL;
52 static struct rlimit num_open;
53 static char msgbuff[256];
54
store_errmsg(const char * msg,int err)55 static void store_errmsg(const char *msg, int err)
56 {
57 if(!err)
58 msnprintf(msgbuff, sizeof(msgbuff), "%s", msg);
59 else
60 msnprintf(msgbuff, sizeof(msgbuff), "%s, errno %d, %s", msg,
61 err, strerror(err));
62 }
63
close_file_descriptors(void)64 static void close_file_descriptors(void)
65 {
66 for(num_open.rlim_cur = 0;
67 num_open.rlim_cur < num_open.rlim_max;
68 num_open.rlim_cur++)
69 if(testfd[num_open.rlim_cur] > 0)
70 close(testfd[num_open.rlim_cur]);
71 free(testfd);
72 testfd = NULL;
73 }
74
fopen_works(void)75 static int fopen_works(void)
76 {
77 FILE *fpa[3];
78 int i;
79 int ret = 1;
80
81 for(i = 0; i < 3; i++) {
82 fpa[i] = NULL;
83 }
84 for(i = 0; i < 3; i++) {
85 fpa[i] = fopen(DEV_NULL, FOPEN_READTEXT);
86 if(!fpa[i]) {
87 store_errmsg("fopen failed", errno);
88 fprintf(stderr, "%s\n", msgbuff);
89 ret = 0;
90 break;
91 }
92 }
93 for(i = 0; i < 3; i++) {
94 if(fpa[i])
95 fclose(fpa[i]);
96 }
97 return ret;
98 }
99
rlim2str(char * buf,size_t len,rlim_t val)100 static void rlim2str(char *buf, size_t len, rlim_t val)
101 {
102 #ifdef RLIM_INFINITY
103 if(val == RLIM_INFINITY) {
104 msnprintf(buf, len, "INFINITY");
105 return;
106 }
107 #endif
108 #ifdef HAVE_LONGLONG
109 if(sizeof(rlim_t) > sizeof(long))
110 msnprintf(buf, len, "%llu", (unsigned long long)val);
111 else
112 #endif
113 {
114 if(sizeof(rlim_t) < sizeof(long))
115 msnprintf(buf, len, "%u", (unsigned int)val);
116 else
117 msnprintf(buf, len, "%lu", (unsigned long)val);
118 }
119 }
120
test_rlimit(int keep_open)121 static int test_rlimit(int keep_open)
122 {
123 int *tmpfd;
124 rlim_t nitems, i;
125 int *memchunk = NULL;
126 struct rlimit rl;
127 char strbuff[256];
128 char strbuff1[81];
129
130 /* get initial open file limits */
131
132 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
133 store_errmsg("getrlimit() failed", errno);
134 fprintf(stderr, "%s\n", msgbuff);
135 return -1;
136 }
137
138 /* show initial open file limits */
139
140 rlim2str(strbuff, sizeof(strbuff), rl.rlim_cur);
141 fprintf(stderr, "initial soft limit: %s\n", strbuff);
142
143 rlim2str(strbuff, sizeof(strbuff), rl.rlim_max);
144 fprintf(stderr, "initial hard limit: %s\n", strbuff);
145
146 /* If the OS allows a HUGE number of open files, we do not run.
147 * Modern debian sid reports a limit of 134217724 and this tests
148 * takes minutes. */
149 #define LIMIT_CAP (256*1024)
150 if(rl.rlim_cur > LIMIT_CAP) {
151 fprintf(stderr, "soft limit above %ld, not running\n", (long)LIMIT_CAP);
152 return -2;
153 }
154
155 /*
156 * if soft limit and hard limit are different we ask the
157 * system to raise soft limit all the way up to the hard
158 * limit. Due to some other system limit the soft limit
159 * might not be raised up to the hard limit. So from this
160 * point the resulting soft limit is our limit. Trying to
161 * open more than soft limit file descriptors will fail.
162 */
163
164 if(rl.rlim_cur != rl.rlim_max) {
165
166 #ifdef OPEN_MAX
167 if((rl.rlim_cur > 0) &&
168 (rl.rlim_cur < OPEN_MAX)) {
169 fprintf(stderr, "raising soft limit up to OPEN_MAX\n");
170 rl.rlim_cur = OPEN_MAX;
171 if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
172 /* on failure don't abort just issue a warning */
173 store_errmsg("setrlimit() failed", errno);
174 fprintf(stderr, "%s\n", msgbuff);
175 msgbuff[0] = '\0';
176 }
177 }
178 #endif
179
180 fprintf(stderr, "raising soft limit up to hard limit\n");
181 rl.rlim_cur = rl.rlim_max;
182 if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
183 /* on failure don't abort just issue a warning */
184 store_errmsg("setrlimit() failed", errno);
185 fprintf(stderr, "%s\n", msgbuff);
186 msgbuff[0] = '\0';
187 }
188
189 /* get current open file limits */
190
191 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
192 store_errmsg("getrlimit() failed", errno);
193 fprintf(stderr, "%s\n", msgbuff);
194 return -3;
195 }
196
197 /* show current open file limits */
198
199 rlim2str(strbuff, sizeof(strbuff), rl.rlim_cur);
200 fprintf(stderr, "current soft limit: %s\n", strbuff);
201
202 rlim2str(strbuff, sizeof(strbuff), rl.rlim_max);
203 fprintf(stderr, "current hard limit: %s\n", strbuff);
204
205 } /* (rl.rlim_cur != rl.rlim_max) */
206
207 /*
208 * test 537 is all about testing libcurl functionality
209 * when the system has nearly exhausted the number of
210 * available file descriptors. Test 537 will try to run
211 * with a very small number of file descriptors available.
212 * This implies that any file descriptor which is open
213 * when the test runs will have a number in the high range
214 * of whatever the system supports.
215 */
216
217 /*
218 * reserve a chunk of memory before opening file descriptors to
219 * avoid a low memory condition once the file descriptors are
220 * open. System conditions that could make the test fail should
221 * be addressed in the precheck phase. This chunk of memory shall
222 * be always free()ed before exiting the test_rlimit() function so
223 * that it becomes available to the test.
224 */
225
226 for(nitems = i = 1; nitems <= i; i *= 2)
227 nitems = i;
228 if(nitems > 0x7fff)
229 nitems = 0x40000;
230 do {
231 num_open.rlim_max = sizeof(*memchunk) * nitems;
232 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
233 fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
234 memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
235 if(!memchunk) {
236 fprintf(stderr, "memchunk, malloc() failed\n");
237 nitems /= 2;
238 }
239 } while(nitems && !memchunk);
240 if(!memchunk) {
241 store_errmsg("memchunk, malloc() failed", errno);
242 fprintf(stderr, "%s\n", msgbuff);
243 return -4;
244 }
245
246 /* initialize it to fight lazy allocation */
247
248 fprintf(stderr, "initializing memchunk array\n");
249
250 for(i = 0; i < nitems; i++)
251 memchunk[i] = -1;
252
253 /* set the number of file descriptors we will try to open */
254
255 #ifdef RLIM_INFINITY
256 if((rl.rlim_cur > 0) && (rl.rlim_cur != RLIM_INFINITY)) {
257 #else
258 if(rl.rlim_cur > 0) {
259 #endif
260 /* soft limit minus SAFETY_MARGIN */
261 num_open.rlim_max = rl.rlim_cur - SAFETY_MARGIN;
262 }
263 else {
264 /* a huge number of file descriptors */
265 for(nitems = i = 1; nitems <= i; i *= 2)
266 nitems = i;
267 if(nitems > 0x7fff)
268 nitems = 0x40000;
269 num_open.rlim_max = nitems;
270 }
271
272 /* verify that we won't overflow size_t in malloc() */
273
274 if((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*testfd)) {
275 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_max);
276 msnprintf(strbuff, sizeof(strbuff), "unable to allocate an array for %s "
277 "file descriptors, would overflow size_t", strbuff1);
278 store_errmsg(strbuff, 0);
279 fprintf(stderr, "%s\n", msgbuff);
280 free(memchunk);
281 return -5;
282 }
283
284 /* allocate array for file descriptors */
285
286 do {
287 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
288 fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
289
290 testfd = malloc(sizeof(*testfd) * (size_t)(num_open.rlim_max));
291 if(!testfd) {
292 fprintf(stderr, "testfd, malloc() failed\n");
293 num_open.rlim_max /= 2;
294 }
295 } while(num_open.rlim_max && !testfd);
296 if(!testfd) {
297 store_errmsg("testfd, malloc() failed", errno);
298 fprintf(stderr, "%s\n", msgbuff);
299 free(memchunk);
300 return -6;
301 }
302
303 /* initialize it to fight lazy allocation */
304
305 fprintf(stderr, "initializing testfd array\n");
306
307 for(num_open.rlim_cur = 0;
308 num_open.rlim_cur < num_open.rlim_max;
309 num_open.rlim_cur++)
310 testfd[num_open.rlim_cur] = -1;
311
312 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
313 fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
314
315 /* open a dummy descriptor */
316
317 testfd[0] = open(DEV_NULL, O_RDONLY);
318 if(testfd[0] < 0) {
319 msnprintf(strbuff, sizeof(strbuff), "opening of %s failed", DEV_NULL);
320 store_errmsg(strbuff, errno);
321 fprintf(stderr, "%s\n", msgbuff);
322 free(testfd);
323 testfd = NULL;
324 free(memchunk);
325 return -7;
326 }
327
328 /* create a bunch of file descriptors */
329
330 for(num_open.rlim_cur = 1;
331 num_open.rlim_cur < num_open.rlim_max;
332 num_open.rlim_cur++) {
333
334 testfd[num_open.rlim_cur] = dup(testfd[0]);
335
336 if(testfd[num_open.rlim_cur] < 0) {
337
338 testfd[num_open.rlim_cur] = -1;
339
340 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
341 msnprintf(strbuff, sizeof(strbuff), "dup() attempt %s failed", strbuff1);
342 fprintf(stderr, "%s\n", strbuff);
343
344 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
345 msnprintf(strbuff, sizeof(strbuff), "fds system limit seems close to %s",
346 strbuff1);
347 fprintf(stderr, "%s\n", strbuff);
348
349 num_open.rlim_max = num_open.rlim_cur - SAFETY_MARGIN;
350
351 num_open.rlim_cur -= num_open.rlim_max;
352 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
353 msnprintf(strbuff, sizeof(strbuff), "closing %s file descriptors",
354 strbuff1);
355 fprintf(stderr, "%s\n", strbuff);
356
357 for(num_open.rlim_cur = num_open.rlim_max;
358 testfd[num_open.rlim_cur] >= 0;
359 num_open.rlim_cur++) {
360 close(testfd[num_open.rlim_cur]);
361 testfd[num_open.rlim_cur] = -1;
362 }
363
364 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
365 fprintf(stderr, "shrinking array for %s file descriptors\n", strbuff);
366
367 /* we don't care if we can't shrink it */
368
369 tmpfd = realloc(testfd, sizeof(*testfd) * (size_t)(num_open.rlim_max));
370 if(tmpfd) {
371 testfd = tmpfd;
372 tmpfd = NULL;
373 }
374
375 break;
376 }
377 }
378
379 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
380 fprintf(stderr, "%s file descriptors open\n", strbuff);
381
382 #if !defined(HAVE_POLL) && !defined(USE_WINSOCK)
383
384 /*
385 * when using select() instead of poll() we cannot test
386 * libcurl functionality with a socket number equal or
387 * greater than FD_SETSIZE. In any case, macro VERIFY_SOCK
388 * in lib/select.c enforces this check and protects libcurl
389 * from a possible crash. The effect of this protection
390 * is that test 537 will always fail, since the actual
391 * call to select() never takes place. We skip test 537
392 * with an indication that select limit would be exceeded.
393 */
394
395 num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
396 if(num_open.rlim_max > num_open.rlim_cur) {
397 msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
398 FD_SETSIZE);
399 store_errmsg(strbuff, 0);
400 fprintf(stderr, "%s\n", msgbuff);
401 close_file_descriptors();
402 free(memchunk);
403 return -8;
404 }
405
406 num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
407 for(rl.rlim_cur = 0;
408 rl.rlim_cur < num_open.rlim_max;
409 rl.rlim_cur++) {
410 if((testfd[rl.rlim_cur] > 0) &&
411 ((unsigned int)testfd[rl.rlim_cur] > num_open.rlim_cur)) {
412 msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
413 FD_SETSIZE);
414 store_errmsg(strbuff, 0);
415 fprintf(stderr, "%s\n", msgbuff);
416 close_file_descriptors();
417 free(memchunk);
418 return -9;
419 }
420 }
421
422 #endif /* using a FD_SETSIZE bound select() */
423
424 /*
425 * Old or 'backwards compatible' implementations of stdio do not allow
426 * handling of streams with an underlying file descriptor number greater
427 * than 255, even when allowing high numbered file descriptors for sockets.
428 * At this point we have a big number of file descriptors which have been
429 * opened using dup(), so lets test the stdio implementation and discover
430 * if it is capable of fopen()ing some additional files.
431 */
432
433 if(!fopen_works()) {
434 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_max);
435 msnprintf(strbuff, sizeof(strbuff), "fopen fails with %s fds open",
436 strbuff1);
437 fprintf(stderr, "%s\n", msgbuff);
438 msnprintf(strbuff, sizeof(strbuff), "fopen fails with lots of fds open");
439 store_errmsg(strbuff, 0);
440 close_file_descriptors();
441 free(memchunk);
442 return -10;
443 }
444
445 /* free the chunk of memory we were reserving so that it
446 becomes available to the test */
447
448 free(memchunk);
449
450 /* close file descriptors unless instructed to keep them */
451
452 if(!keep_open) {
453 close_file_descriptors();
454 }
455
456 return 0;
457 }
458
459 CURLcode test(char *URL)
460 {
461 CURLcode res;
462 CURL *curl;
463
464 if(!strcmp(URL, "check")) {
465 /* used by the test script to ask if we can run this test or not */
466 if(test_rlimit(FALSE)) {
467 fprintf(stdout, "test_rlimit problem: %s\n", msgbuff);
468 return (CURLcode)1;
469 }
470 return CURLE_OK; /* sure, run this! */
471 }
472
473 if(test_rlimit(TRUE)) {
474 /* failure */
475 return TEST_ERR_MAJOR_BAD;
476 }
477
478 /* run the test with the bunch of open file descriptors
479 and close them all once the test is over */
480
481 if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
482 fprintf(stderr, "curl_global_init() failed\n");
483 close_file_descriptors();
484 return TEST_ERR_MAJOR_BAD;
485 }
486
487 curl = curl_easy_init();
488 if(!curl) {
489 fprintf(stderr, "curl_easy_init() failed\n");
490 close_file_descriptors();
491 curl_global_cleanup();
492 return TEST_ERR_MAJOR_BAD;
493 }
494
495 test_setopt(curl, CURLOPT_URL, URL);
496 test_setopt(curl, CURLOPT_HEADER, 1L);
497
498 res = curl_easy_perform(curl);
499
500 test_cleanup:
501
502 close_file_descriptors();
503 curl_easy_cleanup(curl);
504 curl_global_cleanup();
505
506 return res;
507 }
508
509 #else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
510
511 CURLcode test(char *URL)
512 {
513 (void)URL;
514 printf("system lacks necessary system function(s)");
515 return (CURLcode)1; /* skip test */
516 }
517
518 #endif /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
519
