1/***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2021, 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 ***************************************************************************/
22#include "test.h"
23
24#ifdef HAVE_SYS_RESOURCE_H
25#include <sys/resource.h>
26#endif
27#ifdef HAVE_FCNTL_H
28#include <fcntl.h>
29#endif
30#include <limits.h>
31
32#include "warnless.h"
33#include "memdebug.h"
34
35#ifndef FD_SETSIZE
36#error "this test requires FD_SETSIZE"
37#endif
38
39#define SAFETY_MARGIN (16)
40#define NUM_OPEN (FD_SETSIZE + 10)
41#define NUM_NEEDED (NUM_OPEN + SAFETY_MARGIN)
42
43#if defined(WIN32) || 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
51static int *fd = NULL;
52static struct rlimit num_open;
53static char msgbuff[256];
54
55static 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
64static 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(fd[num_open.rlim_cur] > 0)
70 close(fd[num_open.rlim_cur]);
71 free(fd);
72 fd = NULL;
73}
74
75static 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] != NULL)
95 fclose(fpa[i]);
96 }
97 return ret;
98}
99
100static int rlimit(int keep_open)
101{
102 int nitems, i;
103 int *memchunk = NULL;
104 char *fmt;
105 struct rlimit rl;
106 char strbuff[256];
107 char strbuff1[81];
108 char strbuff2[81];
109 char fmt_u[] = "%u";
110 char fmt_lu[] = "%lu";
111#ifdef HAVE_LONGLONG
112 char fmt_llu[] = "%llu";
113
114 if(sizeof(rl.rlim_max) > sizeof(long))
115 fmt = fmt_llu;
116 else
117#endif
118 fmt = (sizeof(rl.rlim_max) < sizeof(long))?fmt_u:fmt_lu;
119
120 /* get initial open file limits */
121
122 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
123 store_errmsg("getrlimit() failed", errno);
124 fprintf(stderr, "%s\n", msgbuff);
125 return -1;
126 }
127
128 /* show initial open file limits */
129
130#ifdef RLIM_INFINITY
131 if(rl.rlim_cur == RLIM_INFINITY)
132 strcpy(strbuff, "INFINITY");
133 else
134#endif
135 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_cur);
136 fprintf(stderr, "initial soft limit: %s\n", strbuff);
137
138#ifdef RLIM_INFINITY
139 if(rl.rlim_max == RLIM_INFINITY)
140 strcpy(strbuff, "INFINITY");
141 else
142#endif
143 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_max);
144 fprintf(stderr, "initial hard limit: %s\n", strbuff);
145
146 /* show our constants */
147
148 fprintf(stderr, "test518 FD_SETSIZE: %d\n", FD_SETSIZE);
149 fprintf(stderr, "test518 NUM_OPEN : %d\n", NUM_OPEN);
150 fprintf(stderr, "test518 NUM_NEEDED: %d\n", NUM_NEEDED);
151
152 /*
153 * if soft limit and hard limit are different we ask the
154 * system to raise soft limit all the way up to the hard
155 * limit. Due to some other system limit the soft limit
156 * might not be raised up to the hard limit. So from this
157 * point the resulting soft limit is our limit. Trying to
158 * open more than soft limit file descriptors will fail.
159 */
160
161 if(rl.rlim_cur != rl.rlim_max) {
162
163#ifdef OPEN_MAX
164 if((rl.rlim_cur > 0) &&
165 (rl.rlim_cur < OPEN_MAX)) {
166 fprintf(stderr, "raising soft limit up to OPEN_MAX\n");
167 rl.rlim_cur = OPEN_MAX;
168 if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
169 /* on failure don't abort just issue a warning */
170 store_errmsg("setrlimit() failed", errno);
171 fprintf(stderr, "%s\n", msgbuff);
172 msgbuff[0] = '\0';
173 }
174 }
175#endif
176
177 fprintf(stderr, "raising soft limit up to hard limit\n");
178 rl.rlim_cur = rl.rlim_max;
179 if(setrlimit(RLIMIT_NOFILE, &rl) != 0) {
180 /* on failure don't abort just issue a warning */
181 store_errmsg("setrlimit() failed", errno);
182 fprintf(stderr, "%s\n", msgbuff);
183 msgbuff[0] = '\0';
184 }
185
186 /* get current open file limits */
187
188 if(getrlimit(RLIMIT_NOFILE, &rl) != 0) {
189 store_errmsg("getrlimit() failed", errno);
190 fprintf(stderr, "%s\n", msgbuff);
191 return -3;
192 }
193
194 /* show current open file limits */
195
196#ifdef RLIM_INFINITY
197 if(rl.rlim_cur == RLIM_INFINITY)
198 strcpy(strbuff, "INFINITY");
199 else
200#endif
201 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_cur);
202 fprintf(stderr, "current soft limit: %s\n", strbuff);
203
204#ifdef RLIM_INFINITY
205 if(rl.rlim_max == RLIM_INFINITY)
206 strcpy(strbuff, "INFINITY");
207 else
208#endif
209 msnprintf(strbuff, sizeof(strbuff), fmt, rl.rlim_max);
210 fprintf(stderr, "current hard limit: %s\n", strbuff);
211
212 } /* (rl.rlim_cur != rl.rlim_max) */
213
214 /*
215 * test 518 is all about testing libcurl functionality
216 * when more than FD_SETSIZE file descriptors are open.
217 * This means that if for any reason we are not able to
218 * open more than FD_SETSIZE file descriptors then test
219 * 518 should not be run.
220 */
221
222 /*
223 * verify that soft limit is higher than NUM_NEEDED,
224 * which is the number of file descriptors we would
225 * try to open plus SAFETY_MARGIN to not exhaust the
226 * file descriptor pool
227 */
228
229 num_open.rlim_cur = NUM_NEEDED;
230
231 if((rl.rlim_cur > 0) &&
232#ifdef RLIM_INFINITY
233 (rl.rlim_cur != RLIM_INFINITY) &&
234#endif
235 (rl.rlim_cur <= num_open.rlim_cur)) {
236 msnprintf(strbuff2, sizeof(strbuff2), fmt, rl.rlim_cur);
237 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
238 msnprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
239 strbuff1, strbuff2);
240 store_errmsg(strbuff, 0);
241 fprintf(stderr, "%s\n", msgbuff);
242 return -4;
243 }
244
245 /*
246 * reserve a chunk of memory before opening file descriptors to
247 * avoid a low memory condition once the file descriptors are
248 * open. System conditions that could make the test fail should
249 * be addressed in the precheck phase. This chunk of memory shall
250 * be always free()ed before exiting the rlimit() function so
251 * that it becomes available to the test.
252 */
253
254 for(nitems = i = 1; nitems <= i; i *= 2)
255 nitems = i;
256 if(nitems > 0x7fff)
257 nitems = 0x40000;
258 do {
259 num_open.rlim_max = sizeof(*memchunk) * (size_t)nitems;
260 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
261 fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
262 memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
263 if(!memchunk) {
264 fprintf(stderr, "memchunk, malloc() failed\n");
265 nitems /= 2;
266 }
267 } while(nitems && !memchunk);
268 if(!memchunk) {
269 store_errmsg("memchunk, malloc() failed", errno);
270 fprintf(stderr, "%s\n", msgbuff);
271 return -5;
272 }
273
274 /* initialize it to fight lazy allocation */
275
276 fprintf(stderr, "initializing memchunk array\n");
277
278 for(i = 0; i < nitems; i++)
279 memchunk[i] = -1;
280
281 /* set the number of file descriptors we will try to open */
282
283 num_open.rlim_max = NUM_OPEN;
284
285 /* verify that we won't overflow size_t in malloc() */
286
287 if((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*fd)) {
288 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_max);
289 msnprintf(strbuff, sizeof(strbuff), "unable to allocate an array for %s "
290 "file descriptors, would overflow size_t", strbuff1);
291 store_errmsg(strbuff, 0);
292 fprintf(stderr, "%s\n", msgbuff);
293 free(memchunk);
294 return -6;
295 }
296
297 /* allocate array for file descriptors */
298
299 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
300 fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
301
302 fd = malloc(sizeof(*fd) * (size_t)(num_open.rlim_max));
303 if(!fd) {
304 store_errmsg("fd, malloc() failed", errno);
305 fprintf(stderr, "%s\n", msgbuff);
306 free(memchunk);
307 return -7;
308 }
309
310 /* initialize it to fight lazy allocation */
311
312 fprintf(stderr, "initializing fd array\n");
313
314 for(num_open.rlim_cur = 0;
315 num_open.rlim_cur < num_open.rlim_max;
316 num_open.rlim_cur++)
317 fd[num_open.rlim_cur] = -1;
318
319 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
320 fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
321
322 /* open a dummy descriptor */
323
324 fd[0] = open(DEV_NULL, O_RDONLY);
325 if(fd[0] < 0) {
326 msnprintf(strbuff, sizeof(strbuff), "opening of %s failed", DEV_NULL);
327 store_errmsg(strbuff, errno);
328 fprintf(stderr, "%s\n", msgbuff);
329 free(fd);
330 fd = NULL;
331 free(memchunk);
332 return -8;
333 }
334
335 /* create a bunch of file descriptors */
336
337 for(num_open.rlim_cur = 1;
338 num_open.rlim_cur < num_open.rlim_max;
339 num_open.rlim_cur++) {
340
341 fd[num_open.rlim_cur] = dup(fd[0]);
342
343 if(fd[num_open.rlim_cur] < 0) {
344
345 fd[num_open.rlim_cur] = -1;
346
347 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
348 msnprintf(strbuff, sizeof(strbuff), "dup() attempt %s failed", strbuff1);
349 fprintf(stderr, "%s\n", strbuff);
350
351 msnprintf(strbuff1, sizeof(strbuff), fmt, num_open.rlim_cur);
352 msnprintf(strbuff, sizeof(strbuff), "fds system limit seems close to %s",
353 strbuff1);
354 fprintf(stderr, "%s\n", strbuff);
355
356 num_open.rlim_max = NUM_NEEDED;
357
358 msnprintf(strbuff2, sizeof(strbuff2), fmt, num_open.rlim_max);
359 msnprintf(strbuff1, sizeof(strbuff1), fmt, num_open.rlim_cur);
360 msnprintf(strbuff, sizeof(strbuff), "fds needed %s > system limit %s",
361 strbuff2, strbuff1);
362 store_errmsg(strbuff, 0);
363 fprintf(stderr, "%s\n", msgbuff);
364
365 for(num_open.rlim_cur = 0;
366 fd[num_open.rlim_cur] >= 0;
367 num_open.rlim_cur++)
368 close(fd[num_open.rlim_cur]);
369 free(fd);
370 fd = NULL;
371 free(memchunk);
372 return -9;
373
374 }
375
376 }
377
378 msnprintf(strbuff, sizeof(strbuff), fmt, num_open.rlim_max);
379 fprintf(stderr, "%s file descriptors open\n", strbuff);
380
381#if !defined(HAVE_POLL_FINE) && \
382 !defined(USE_WINSOCK) && \
383 !defined(TPF)
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
462int 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
503test_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
514int 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