xref: /third_party/curl/tests/libtest/lib518.c (revision 13498266)
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
53static int *fd = NULL;
54static struct rlimit num_open;
55static char msgbuff[256];
56
57static 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
66static 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
77static 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
102static 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
123static int 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 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(*fd)) {
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  fd = malloc(sizeof(*fd) * (size_t)(num_open.rlim_max));
295  if(!fd) {
296    store_errmsg("fd, 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 fd 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    fd[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  fd[0] = open(DEV_NULL, O_RDONLY);
317  if(fd[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(fd);
322    fd = 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    fd[num_open.rlim_cur] = dup(fd[0]);
334
335    if(fd[num_open.rlim_cur] < 0) {
336
337      fd[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          fd[num_open.rlim_cur] >= 0;
359          num_open.rlim_cur++)
360        close(fd[num_open.rlim_cur]);
361      free(fd);
362      fd = 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((fd[rl.rlim_cur] > 0) &&
400       ((unsigned int)fd[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 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
448int 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(rlimit(FALSE)) {
456      fprintf(stdout, "rlimit problem: %s\n", msgbuff);
457      return 1;
458    }
459    return 0; /* sure, run this! */
460  }
461
462  if(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
489test_cleanup:
490
491  close_file_descriptors();
492  curl_easy_cleanup(curl);
493  curl_global_cleanup();
494
495  return (int)res;
496}
497
498#else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
499
500int 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