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 #ifndef FD_SETSIZE
38 #error "this test requires FD_SETSIZE"
39 #endif
40
41 #define SAFETY_MARGIN (16)
42 #define NUM_OPEN (FD_SETSIZE + 10)
43 #define NUM_NEEDED (NUM_OPEN + SAFETY_MARGIN)
44
45 #if defined(_WIN32) || defined(MSDOS)
46 #define DEV_NULL "NUL"
47 #else
48 #define DEV_NULL "/dev/null"
49 #endif
50
51 #if defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT)
52
53 static int *testfd = NULL;
54 static struct rlimit num_open;
55 static char msgbuff[256];
56
store_errmsg(const char * msg,int err)57 static void store_errmsg(const char *msg, int err)
58 {
59 if(!err)
60 msnprintf(msgbuff, sizeof(msgbuff), "%s", msg);
61 else
62 msnprintf(msgbuff, sizeof(msgbuff), "%s, errno %d, %s", msg,
63 err, strerror(err));
64 }
65
close_file_descriptors(void)66 static void close_file_descriptors(void)
67 {
68 for(num_open.rlim_cur = 0;
69 num_open.rlim_cur < num_open.rlim_max;
70 num_open.rlim_cur++)
71 if(testfd[num_open.rlim_cur] > 0)
72 close(testfd[num_open.rlim_cur]);
73 free(testfd);
74 testfd = NULL;
75 }
76
fopen_works(void)77 static int fopen_works(void)
78 {
79 FILE *fpa[3];
80 int i;
81 int ret = 1;
82
83 for(i = 0; i < 3; i++) {
84 fpa[i] = NULL;
85 }
86 for(i = 0; i < 3; i++) {
87 fpa[i] = fopen(DEV_NULL, FOPEN_READTEXT);
88 if(!fpa[i]) {
89 store_errmsg("fopen failed", errno);
90 fprintf(stderr, "%s\n", msgbuff);
91 ret = 0;
92 break;
93 }
94 }
95 for(i = 0; i < 3; i++) {
96 if(fpa[i])
97 fclose(fpa[i]);
98 }
99 return ret;
100 }
101
rlim2str(char * buf,size_t len,rlim_t val)102 static void rlim2str(char *buf, size_t len, rlim_t val)
103 {
104 #ifdef RLIM_INFINITY
105 if(val == RLIM_INFINITY) {
106 msnprintf(buf, len, "INFINITY");
107 return;
108 }
109 #endif
110 #ifdef HAVE_LONGLONG
111 if(sizeof(rlim_t) > sizeof(long))
112 msnprintf(buf, len, "%llu", (unsigned long long)val);
113 else
114 #endif
115 {
116 if(sizeof(rlim_t) < sizeof(long))
117 msnprintf(buf, len, "%u", (unsigned int)val);
118 else
119 msnprintf(buf, len, "%lu", (unsigned long)val);
120 }
121 }
122
test_rlimit(int keep_open)123 static int test_rlimit(int keep_open)
124 {
125 rlim_t nitems, i;
126 int *memchunk = NULL;
127 struct rlimit rl;
128 char strbuff[256];
129 char strbuff1[81];
130 char strbuff2[81];
131
132 /* get initial open file limits */
133
134 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
135 store_errmsg("getrlimit() failed", errno);
136 fprintf(stderr, "%s\n", msgbuff);
137 return -1;
138 }
139
140 /* show initial open file limits */
141
142 rlim2str(strbuff, sizeof(strbuff), rl.rlim_cur);
143 fprintf(stderr, "initial soft limit: %s\n", strbuff);
144
145 rlim2str(strbuff, sizeof(strbuff), rl.rlim_max);
146 fprintf(stderr, "initial hard limit: %s\n", strbuff);
147
148 /* show our constants */
149
150 fprintf(stderr, "test518 FD_SETSIZE: %d\n", FD_SETSIZE);
151 fprintf(stderr, "test518 NUM_OPEN : %d\n", NUM_OPEN);
152 fprintf(stderr, "test518 NUM_NEEDED: %d\n", NUM_NEEDED);
153
154 /*
155 * if soft limit and hard limit are different we ask the
156 * system to raise soft limit all the way up to the hard
157 * limit. Due to some other system limit the soft limit
158 * might not be raised up to the hard limit. So from this
159 * point the resulting soft limit is our limit. Trying to
160 * open more than soft limit file descriptors will fail.
161 */
162
163 if(rl.rlim_cur != rl.rlim_max) {
164
165 #ifdef OPEN_MAX
166 if((rl.rlim_cur > 0) &&
167 (rl.rlim_cur < OPEN_MAX)) {
168 fprintf(stderr, "raising soft limit up to OPEN_MAX\n");
169 rl.rlim_cur = OPEN_MAX;
170 if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
171 /* on failure don't abort just issue a warning */
172 store_errmsg("setrlimit() failed", errno);
173 fprintf(stderr, "%s\n", msgbuff);
174 msgbuff[0] = '\0';
175 }
176 }
177 #endif
178
179 fprintf(stderr, "raising soft limit up to hard limit\n");
180 rl.rlim_cur = rl.rlim_max;
181 if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
182 /* on failure don't abort just issue a warning */
183 store_errmsg("setrlimit() failed", errno);
184 fprintf(stderr, "%s\n", msgbuff);
185 msgbuff[0] = '\0';
186 }
187
188 /* get current open file limits */
189
190 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
191 store_errmsg("getrlimit() failed", errno);
192 fprintf(stderr, "%s\n", msgbuff);
193 return -3;
194 }
195
196 /* show current open file limits */
197
198 rlim2str(strbuff, sizeof(strbuff), rl.rlim_cur);
199 fprintf(stderr, "current soft limit: %s\n", strbuff);
200
201 rlim2str(strbuff, sizeof(strbuff), rl.rlim_max);
202 fprintf(stderr, "current hard limit: %s\n", strbuff);
203
204 } /* (rl.rlim_cur != rl.rlim_max) */
205
206 /*
207 * test 518 is all about testing libcurl functionality
208 * when more than FD_SETSIZE file descriptors are open.
209 * This means that if for any reason we are not able to
210 * open more than FD_SETSIZE file descriptors then test
211 * 518 should not be run.
212 */
213
214 /*
215 * verify that soft limit is higher than NUM_NEEDED,
216 * which is the number of file descriptors we would
217 * try to open plus SAFETY_MARGIN to not exhaust the
218 * file descriptor pool
219 */
220
221 num_open.rlim_cur = NUM_NEEDED;
222
223 if((rl.rlim_cur > 0) &&
224 #ifdef RLIM_INFINITY
225 (rl.rlim_cur != RLIM_INFINITY) &&
226 #endif
227 (rl.rlim_cur <= num_open.rlim_cur)) {
228 rlim2str(strbuff2, sizeof(strbuff2), rl.rlim_cur);
229 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
230 msnprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
231 strbuff1, strbuff2);
232 store_errmsg(strbuff, 0);
233 fprintf(stderr, "%s\n", msgbuff);
234 return -4;
235 }
236
237 /*
238 * reserve a chunk of memory before opening file descriptors to
239 * avoid a low memory condition once the file descriptors are
240 * open. System conditions that could make the test fail should
241 * be addressed in the precheck phase. This chunk of memory shall
242 * be always free()ed before exiting the test_rlimit() function so
243 * that it becomes available to the test.
244 */
245
246 for(nitems = i = 1; nitems <= i; i *= 2)
247 nitems = i;
248 if(nitems > 0x7fff)
249 nitems = 0x40000;
250 do {
251 num_open.rlim_max = sizeof(*memchunk) * nitems;
252 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
253 fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
254 memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
255 if(!memchunk) {
256 fprintf(stderr, "memchunk, malloc() failed\n");
257 nitems /= 2;
258 }
259 } while(nitems && !memchunk);
260 if(!memchunk) {
261 store_errmsg("memchunk, malloc() failed", errno);
262 fprintf(stderr, "%s\n", msgbuff);
263 return -5;
264 }
265
266 /* initialize it to fight lazy allocation */
267
268 fprintf(stderr, "initializing memchunk array\n");
269
270 for(i = 0; i < nitems; i++)
271 memchunk[i] = -1;
272
273 /* set the number of file descriptors we will try to open */
274
275 num_open.rlim_max = NUM_OPEN;
276
277 /* verify that we won't overflow size_t in malloc() */
278
279 if((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*testfd)) {
280 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_max);
281 msnprintf(strbuff, sizeof(strbuff), "unable to allocate an array for %s "
282 "file descriptors, would overflow size_t", strbuff1);
283 store_errmsg(strbuff, 0);
284 fprintf(stderr, "%s\n", msgbuff);
285 free(memchunk);
286 return -6;
287 }
288
289 /* allocate array for file descriptors */
290
291 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
292 fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
293
294 testfd = malloc(sizeof(*testfd) * (size_t)(num_open.rlim_max));
295 if(!testfd) {
296 store_errmsg("testfd, malloc() failed", errno);
297 fprintf(stderr, "%s\n", msgbuff);
298 free(memchunk);
299 return -7;
300 }
301
302 /* initialize it to fight lazy allocation */
303
304 fprintf(stderr, "initializing testfd array\n");
305
306 for(num_open.rlim_cur = 0;
307 num_open.rlim_cur < num_open.rlim_max;
308 num_open.rlim_cur++)
309 testfd[num_open.rlim_cur] = -1;
310
311 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
312 fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
313
314 /* open a dummy descriptor */
315
316 testfd[0] = open(DEV_NULL, O_RDONLY);
317 if(testfd[0] < 0) {
318 msnprintf(strbuff, sizeof(strbuff), "opening of %s failed", DEV_NULL);
319 store_errmsg(strbuff, errno);
320 fprintf(stderr, "%s\n", msgbuff);
321 free(testfd);
322 testfd = NULL;
323 free(memchunk);
324 return -8;
325 }
326
327 /* create a bunch of file descriptors */
328
329 for(num_open.rlim_cur = 1;
330 num_open.rlim_cur < num_open.rlim_max;
331 num_open.rlim_cur++) {
332
333 testfd[num_open.rlim_cur] = dup(testfd[0]);
334
335 if(testfd[num_open.rlim_cur] < 0) {
336
337 testfd[num_open.rlim_cur] = -1;
338
339 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
340 msnprintf(strbuff, sizeof(strbuff), "dup() attempt %s failed", strbuff1);
341 fprintf(stderr, "%s\n", strbuff);
342
343 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
344 msnprintf(strbuff, sizeof(strbuff), "fds system limit seems close to %s",
345 strbuff1);
346 fprintf(stderr, "%s\n", strbuff);
347
348 num_open.rlim_max = NUM_NEEDED;
349
350 rlim2str(strbuff2, sizeof(strbuff2), num_open.rlim_max);
351 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_cur);
352 msnprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
353 strbuff2, strbuff1);
354 store_errmsg(strbuff, 0);
355 fprintf(stderr, "%s\n", msgbuff);
356
357 for(num_open.rlim_cur = 0;
358 testfd[num_open.rlim_cur] >= 0;
359 num_open.rlim_cur++)
360 close(testfd[num_open.rlim_cur]);
361 free(testfd);
362 testfd = NULL;
363 free(memchunk);
364 return -9;
365 }
366 }
367
368 rlim2str(strbuff, sizeof(strbuff), num_open.rlim_max);
369 fprintf(stderr, "%s file descriptors open\n", strbuff);
370
371 #if !defined(HAVE_POLL_FINE) && !defined(USE_WINSOCK)
372
373 /*
374 * when using select() instead of poll() we cannot test
375 * libcurl functionality with a socket number equal or
376 * greater than FD_SETSIZE. In any case, macro VERIFY_SOCK
377 * in lib/select.c enforces this check and protects libcurl
378 * from a possible crash. The effect of this protection
379 * is that test 518 will always fail, since the actual
380 * call to select() never takes place. We skip test 518
381 * with an indication that select limit would be exceeded.
382 */
383
384 num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
385 if(num_open.rlim_max > num_open.rlim_cur) {
386 msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
387 FD_SETSIZE);
388 store_errmsg(strbuff, 0);
389 fprintf(stderr, "%s\n", msgbuff);
390 close_file_descriptors();
391 free(memchunk);
392 return -10;
393 }
394
395 num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
396 for(rl.rlim_cur = 0;
397 rl.rlim_cur < num_open.rlim_max;
398 rl.rlim_cur++) {
399 if((testfd[rl.rlim_cur] > 0) &&
400 ((unsigned int)testfd[rl.rlim_cur] > num_open.rlim_cur)) {
401 msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
402 FD_SETSIZE);
403 store_errmsg(strbuff, 0);
404 fprintf(stderr, "%s\n", msgbuff);
405 close_file_descriptors();
406 free(memchunk);
407 return -11;
408 }
409 }
410
411 #endif /* using a FD_SETSIZE bound select() */
412
413 /*
414 * Old or 'backwards compatible' implementations of stdio do not allow
415 * handling of streams with an underlying file descriptor number greater
416 * than 255, even when allowing high numbered file descriptors for sockets.
417 * At this point we have a big number of file descriptors which have been
418 * opened using dup(), so lets test the stdio implementation and discover
419 * if it is capable of fopen()ing some additional files.
420 */
421
422 if(!fopen_works()) {
423 rlim2str(strbuff1, sizeof(strbuff1), num_open.rlim_max);
424 msnprintf(strbuff, sizeof(strbuff), "fopen fails with %s fds open",
425 strbuff1);
426 fprintf(stderr, "%s\n", msgbuff);
427 msnprintf(strbuff, sizeof(strbuff), "fopen fails with lots of fds open");
428 store_errmsg(strbuff, 0);
429 close_file_descriptors();
430 free(memchunk);
431 return -12;
432 }
433
434 /* free the chunk of memory we were reserving so that it
435 becomes available to the test */
436
437 free(memchunk);
438
439 /* close file descriptors unless instructed to keep them */
440
441 if(!keep_open) {
442 close_file_descriptors();
443 }
444
445 return 0;
446 }
447
test(char * URL)448 CURLcode test(char *URL)
449 {
450 CURLcode res;
451 CURL *curl;
452
453 if(!strcmp(URL, "check")) {
454 /* used by the test script to ask if we can run this test or not */
455 if(test_rlimit(FALSE)) {
456 fprintf(stdout, "test_rlimit problem: %s\n", msgbuff);
457 return (CURLcode)1;
458 }
459 return CURLE_OK; /* sure, run this! */
460 }
461
462 if(test_rlimit(TRUE)) {
463 /* failure */
464 return TEST_ERR_MAJOR_BAD;
465 }
466
467 /* run the test with the bunch of open file descriptors
468 and close them all once the test is over */
469
470 if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
471 fprintf(stderr, "curl_global_init() failed\n");
472 close_file_descriptors();
473 return TEST_ERR_MAJOR_BAD;
474 }
475
476 curl = curl_easy_init();
477 if(!curl) {
478 fprintf(stderr, "curl_easy_init() failed\n");
479 close_file_descriptors();
480 curl_global_cleanup();
481 return TEST_ERR_MAJOR_BAD;
482 }
483
484 test_setopt(curl, CURLOPT_URL, URL);
485 test_setopt(curl, CURLOPT_HEADER, 1L);
486
487 res = curl_easy_perform(curl);
488
489 test_cleanup:
490
491 close_file_descriptors();
492 curl_easy_cleanup(curl);
493 curl_global_cleanup();
494
495 return res;
496 }
497
498 #else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
499
test(char * URL)500 CURLcode test(char *URL)
501 {
502 (void)URL;
503 printf("system lacks necessary system function(s)");
504 return 1; /* skip test */
505 }
506
507 #endif /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
508
