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(_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 *fd = 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(fd[num_open.rlim_cur] > 0)
72 close(fd[num_open.rlim_cur]);
73 free(fd);
74 fd = 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
rlimit(int keep_open)102 static int rlimit(int keep_open)
103 {
104 int nitems, i;
105 int *memchunk = NULL;
106 char *fmt;
107 struct rlimit rl;
108 char strbuff[256];
109 char strbuff1[81];
110 char strbuff2[81];
111 char fmt_u[] = "%u";
112 char fmt_lu[] = "%lu";
113 #ifdef HAVE_LONGLONG
114 char fmt_llu[] = "%llu";
115
116 if(sizeof(rl.rlim_max) > sizeof(long))
117 fmt = fmt_llu;
118 else
119 #endif
120 fmt = (sizeof(rl.rlim_max) < sizeof(long))?fmt_u:fmt_lu;
121
122 /* get initial open file limits */
123
124 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
125 store_errmsg("getrlimit() failed", errno);
126 fprintf(stderr, "%s\n", msgbuff);
127 return -1;
128 }
129
130 /* show initial open file limits */
131
132 #ifdef RLIM_INFINITY
133 if(rl.rlim_cur == RLIM_INFINITY)
134 strcpy(strbuff, "INFINITY");
135 else
136 #endif
137 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_cur);
138 fprintf(stderr, "initial soft limit: %s\n", strbuff);
139
140 #ifdef RLIM_INFINITY
141 if(rl.rlim_max == RLIM_INFINITY)
142 strcpy(strbuff, "INFINITY");
143 else
144 #endif
145 msnprintf(strbuff, sizeof(strbuff), fmt, 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 #ifdef RLIM_INFINITY
199 if(rl.rlim_cur == RLIM_INFINITY)
200 strcpy(strbuff, "INFINITY");
201 else
202 #endif
203 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_cur);
204 fprintf(stderr, "current soft limit: %s\n", strbuff);
205
206 #ifdef RLIM_INFINITY
207 if(rl.rlim_max == RLIM_INFINITY)
208 strcpy(strbuff, "INFINITY");
209 else
210 #endif
211 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_max);
212 fprintf(stderr, "current hard limit: %s\n", strbuff);
213
214 } /* (rl.rlim_cur != rl.rlim_max) */
215
216 /*
217 * test 518 is all about testing libcurl functionality
218 * when more than FD_SETSIZE file descriptors are open.
219 * This means that if for any reason we are not able to
220 * open more than FD_SETSIZE file descriptors then test
221 * 518 should not be run.
222 */
223
224 /*
225 * verify that soft limit is higher than NUM_NEEDED,
226 * which is the number of file descriptors we would
227 * try to open plus SAFETY_MARGIN to not exhaust the
228 * file descriptor pool
229 */
230
231 num_open.rlim_cur = NUM_NEEDED;
232
233 if((rl.rlim_cur > 0) &&
234 #ifdef RLIM_INFINITY
235 (rl.rlim_cur != RLIM_INFINITY) &&
236 #endif
237 (rl.rlim_cur <= num_open.rlim_cur)) {
238 msnprintf(strbuff2, sizeof(strbuff2), fmt, rl.rlim_cur);
239 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
240 msnprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
241 strbuff1, strbuff2);
242 store_errmsg(strbuff, 0);
243 fprintf(stderr, "%s\n", msgbuff);
244 return -4;
245 }
246
247 /*
248 * reserve a chunk of memory before opening file descriptors to
249 * avoid a low memory condition once the file descriptors are
250 * open. System conditions that could make the test fail should
251 * be addressed in the precheck phase. This chunk of memory shall
252 * be always free()ed before exiting the rlimit() function so
253 * that it becomes available to the test.
254 */
255
256 for(nitems = i = 1; nitems <= i; i *= 2)
257 nitems = i;
258 if(nitems > 0x7fff)
259 nitems = 0x40000;
260 do {
261 num_open.rlim_max = sizeof(*memchunk) * (size_t)nitems;
262 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
263 fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
264 memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
265 if(!memchunk) {
266 fprintf(stderr, "memchunk, malloc() failed\n");
267 nitems /= 2;
268 }
269 } while(nitems && !memchunk);
270 if(!memchunk) {
271 store_errmsg("memchunk, malloc() failed", errno);
272 fprintf(stderr, "%s\n", msgbuff);
273 return -5;
274 }
275
276 /* initialize it to fight lazy allocation */
277
278 fprintf(stderr, "initializing memchunk array\n");
279
280 for(i = 0; i < nitems; i++)
281 memchunk[i] = -1;
282
283 /* set the number of file descriptors we will try to open */
284
285 num_open.rlim_max = NUM_OPEN;
286
287 /* verify that we won't overflow size_t in malloc() */
288
289 if((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*fd)) {
290 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_max);
291 msnprintf(strbuff, sizeof(strbuff), "unable to allocate an array for %s "
292 "file descriptors, would overflow size_t", strbuff1);
293 store_errmsg(strbuff, 0);
294 fprintf(stderr, "%s\n", msgbuff);
295 free(memchunk);
296 return -6;
297 }
298
299 /* allocate array for file descriptors */
300
301 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
302 fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
303
304 fd = malloc(sizeof(*fd) * (size_t)(num_open.rlim_max));
305 if(!fd) {
306 store_errmsg("fd, malloc() failed", errno);
307 fprintf(stderr, "%s\n", msgbuff);
308 free(memchunk);
309 return -7;
310 }
311
312 /* initialize it to fight lazy allocation */
313
314 fprintf(stderr, "initializing fd array\n");
315
316 for(num_open.rlim_cur = 0;
317 num_open.rlim_cur < num_open.rlim_max;
318 num_open.rlim_cur++)
319 fd[num_open.rlim_cur] = -1;
320
321 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
322 fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
323
324 /* open a dummy descriptor */
325
326 fd[0] = open(DEV_NULL, O_RDONLY);
327 if(fd[0] < 0) {
328 msnprintf(strbuff, sizeof(strbuff), "opening of %s failed", DEV_NULL);
329 store_errmsg(strbuff, errno);
330 fprintf(stderr, "%s\n", msgbuff);
331 free(fd);
332 fd = NULL;
333 free(memchunk);
334 return -8;
335 }
336
337 /* create a bunch of file descriptors */
338
339 for(num_open.rlim_cur = 1;
340 num_open.rlim_cur < num_open.rlim_max;
341 num_open.rlim_cur++) {
342
343 fd[num_open.rlim_cur] = dup(fd[0]);
344
345 if(fd[num_open.rlim_cur] < 0) {
346
347 fd[num_open.rlim_cur] = -1;
348
349 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
350 msnprintf(strbuff, sizeof(strbuff), "dup() attempt %s failed", strbuff1);
351 fprintf(stderr, "%s\n", strbuff);
352
353 msnprintf(strbuff1, sizeof(strbuff), fmt, num_open.rlim_cur);
354 msnprintf(strbuff, sizeof(strbuff), "fds system limit seems close to %s",
355 strbuff1);
356 fprintf(stderr, "%s\n", strbuff);
357
358 num_open.rlim_max = NUM_NEEDED;
359
360 msnprintf(strbuff2, sizeof(strbuff2), fmt, num_open.rlim_max);
361 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
362 msnprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
363 strbuff2, strbuff1);
364 store_errmsg(strbuff, 0);
365 fprintf(stderr, "%s\n", msgbuff);
366
367 for(num_open.rlim_cur = 0;
368 fd[num_open.rlim_cur] >= 0;
369 num_open.rlim_cur++)
370 close(fd[num_open.rlim_cur]);
371 free(fd);
372 fd = NULL;
373 free(memchunk);
374 return -9;
375
376 }
377
378 }
379
380 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
381 fprintf(stderr, "%s file descriptors open\n", strbuff);
382
383 #if !defined(HAVE_POLL_FINE) && !defined(USE_WINSOCK)
384
385 /*
386 * when using select() instead of poll() we cannot test
387 * libcurl functionality with a socket number equal or
388 * greater than FD_SETSIZE. In any case, macro VERIFY_SOCK
389 * in lib/select.c enforces this check and protects libcurl
390 * from a possible crash. The effect of this protection
391 * is that test 518 will always fail, since the actual
392 * call to select() never takes place. We skip test 518
393 * with an indication that select limit would be exceeded.
394 */
395
396 num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
397 if(num_open.rlim_max > num_open.rlim_cur) {
398 msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
399 FD_SETSIZE);
400 store_errmsg(strbuff, 0);
401 fprintf(stderr, "%s\n", msgbuff);
402 close_file_descriptors();
403 free(memchunk);
404 return -10;
405 }
406
407 num_open.rlim_cur = FD_SETSIZE - SAFETY_MARGIN;
408 for(rl.rlim_cur = 0;
409 rl.rlim_cur < num_open.rlim_max;
410 rl.rlim_cur++) {
411 if((fd[rl.rlim_cur] > 0) &&
412 ((unsigned int)fd[rl.rlim_cur] > num_open.rlim_cur)) {
413 msnprintf(strbuff, sizeof(strbuff), "select limit is FD_SETSIZE %d",
414 FD_SETSIZE);
415 store_errmsg(strbuff, 0);
416 fprintf(stderr, "%s\n", msgbuff);
417 close_file_descriptors();
418 free(memchunk);
419 return -11;
420 }
421 }
422
423 #endif /* using a FD_SETSIZE bound select() */
424
425 /*
426 * Old or 'backwards compatible' implementations of stdio do not allow
427 * handling of streams with an underlying file descriptor number greater
428 * than 255, even when allowing high numbered file descriptors for sockets.
429 * At this point we have a big number of file descriptors which have been
430 * opened using dup(), so lets test the stdio implementation and discover
431 * if it is capable of fopen()ing some additional files.
432 */
433
434 if(!fopen_works()) {
435 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_max);
436 msnprintf(strbuff, sizeof(strbuff),
437 "fopen fails with %s fds open()",
438 strbuff1);
439 fprintf(stderr, "%s\n", msgbuff);
440 msnprintf(strbuff, sizeof(strbuff),
441 "fopen fails with lots of fds open()");
442 store_errmsg(strbuff, 0);
443 close_file_descriptors();
444 free(memchunk);
445 return -12;
446 }
447
448 /* free the chunk of memory we were reserving so that it
449 becomes becomes available to the test */
450
451 free(memchunk);
452
453 /* close file descriptors unless instructed to keep them */
454
455 if(!keep_open) {
456 close_file_descriptors();
457 }
458
459 return 0;
460 }
461
test(char * URL)462 int test(char *URL)
463 {
464 CURLcode res;
465 CURL *curl;
466
467 if(!strcmp(URL, "check")) {
468 /* used by the test script to ask if we can run this test or not */
469 if(rlimit(FALSE)) {
470 fprintf(stdout, "rlimit problem: %s\n", msgbuff);
471 return 1;
472 }
473 return 0; /* sure, run this! */
474 }
475
476 if(rlimit(TRUE)) {
477 /* failure */
478 return TEST_ERR_MAJOR_BAD;
479 }
480
481 /* run the test with the bunch of open file descriptors
482 and close them all once the test is over */
483
484 if(curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
485 fprintf(stderr, "curl_global_init() failed\n");
486 close_file_descriptors();
487 return TEST_ERR_MAJOR_BAD;
488 }
489
490 curl = curl_easy_init();
491 if(!curl) {
492 fprintf(stderr, "curl_easy_init() failed\n");
493 close_file_descriptors();
494 curl_global_cleanup();
495 return TEST_ERR_MAJOR_BAD;
496 }
497
498 test_setopt(curl, CURLOPT_URL, URL);
499 test_setopt(curl, CURLOPT_HEADER, 1L);
500
501 res = curl_easy_perform(curl);
502
503 test_cleanup:
504
505 close_file_descriptors();
506 curl_easy_cleanup(curl);
507 curl_global_cleanup();
508
509 return (int)res;
510 }
511
512 #else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
513
test(char * URL)514 int test(char *URL)
515 {
516 (void)URL;
517 printf("system lacks necessary system function(s)");
518 return 1; /* skip test */
519 }
520
521 #endif /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
522