1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 1998 - 2011, 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 http://curl.haxx.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 #ifdef HAVE_LIMITS_H
31 #include <limits.h>
32 #endif
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     sprintf(msgbuff, "%s", msg);
61   else
62     sprintf(msgbuff, "%s, errno %d, %s", msg, err, strerror(err));
63 }
64 
close_file_descriptors(void)65 static void close_file_descriptors(void)
66 {
67   for (num_open.rlim_cur = 0;
68        num_open.rlim_cur < num_open.rlim_max;
69        num_open.rlim_cur++)
70     if (fd[num_open.rlim_cur] > 0)
71       close(fd[num_open.rlim_cur]);
72   free(fd);
73   fd = NULL;
74 }
75 
fopen_works(void)76 static int fopen_works(void)
77 {
78   FILE *fpa[3];
79   int i;
80   int ret = 1;
81 
82   for (i = 0; i < 3; i++) {
83     fpa[i] = NULL;
84   }
85   for (i = 0; i < 3; i++) {
86     fpa[i] = fopen(DEV_NULL, "r");
87     if (fpa[i] == NULL) {
88       store_errmsg("fopen() failed", ERRNO);
89       fprintf(stderr, "%s\n", msgbuff);
90       ret = 0;
91       break;
92     }
93   }
94   for (i = 0; i < 3; i++) {
95     if (fpa[i] != NULL)
96       fclose(fpa[i]);
97   }
98   return ret;
99 }
100 
rlimit(int keep_open)101 static int rlimit(int keep_open)
102 {
103   int nitems, i;
104   int *memchunk = NULL;
105   char *fmt;
106   struct rlimit rl;
107   char strbuff[256];
108   char strbuff1[81];
109   char strbuff2[81];
110   char fmt_u[] = "%u";
111   char fmt_lu[] = "%lu";
112 #ifdef HAVE_LONGLONG
113   char fmt_llu[] = "%llu";
114 
115   if (sizeof(rl.rlim_max) > sizeof(long))
116     fmt = fmt_llu;
117   else
118 #endif
119     fmt = (sizeof(rl.rlim_max) < sizeof(long))?fmt_u:fmt_lu;
120 
121   /* get initial open file limits */
122 
123   if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
124     store_errmsg("getrlimit() failed", ERRNO);
125     fprintf(stderr, "%s\n", msgbuff);
126     return -1;
127   }
128 
129   /* show initial open file limits */
130 
131 #ifdef RLIM_INFINITY
132   if (rl.rlim_cur == RLIM_INFINITY)
133     strcpy(strbuff, "INFINITY");
134   else
135 #endif
136     sprintf(strbuff, fmt, rl.rlim_cur);
137   fprintf(stderr, "initial soft limit: %s\n", strbuff);
138 
139 #ifdef RLIM_INFINITY
140   if (rl.rlim_max == RLIM_INFINITY)
141     strcpy(strbuff, "INFINITY");
142   else
143 #endif
144     sprintf(strbuff, fmt, rl.rlim_max);
145   fprintf(stderr, "initial hard limit: %s\n", strbuff);
146 
147   /* show our constants */
148 
149   fprintf(stderr, "test518 FD_SETSIZE: %d\n", FD_SETSIZE);
150   fprintf(stderr, "test518 NUM_OPEN  : %d\n", NUM_OPEN);
151   fprintf(stderr, "test518 NUM_NEEDED: %d\n", NUM_NEEDED);
152 
153   /*
154    * if soft limit and hard limit are different we ask the
155    * system to raise soft limit all the way up to the hard
156    * limit. Due to some other system limit the soft limit
157    * might not be raised up to the hard limit. So from this
158    * point the resulting soft limit is our limit. Trying to
159    * open more than soft limit file descriptors will fail.
160    */
161 
162   if (rl.rlim_cur != rl.rlim_max) {
163 
164 #ifdef OPEN_MAX
165     if ((rl.rlim_cur > 0) &&
166         (rl.rlim_cur < OPEN_MAX)) {
167       fprintf(stderr, "raising soft limit up to OPEN_MAX\n");
168       rl.rlim_cur = OPEN_MAX;
169       if (setrlimit(RLIMIT_NOFILE, &rl) != 0) {
170         /* on failure don't abort just issue a warning */
171         store_errmsg("setrlimit() failed", ERRNO);
172         fprintf(stderr, "%s\n", msgbuff);
173         msgbuff[0] = '\0';
174       }
175     }
176 #endif
177 
178     fprintf(stderr, "raising soft limit up to hard limit\n");
179     rl.rlim_cur = rl.rlim_max;
180     if (setrlimit(RLIMIT_NOFILE, &rl) != 0) {
181       /* on failure don't abort just issue a warning */
182       store_errmsg("setrlimit() failed", ERRNO);
183       fprintf(stderr, "%s\n", msgbuff);
184       msgbuff[0] = '\0';
185     }
186 
187     /* get current open file limits */
188 
189     if (getrlimit(RLIMIT_NOFILE, &rl) != 0) {
190       store_errmsg("getrlimit() failed", ERRNO);
191       fprintf(stderr, "%s\n", msgbuff);
192       return -3;
193     }
194 
195     /* show current open file limits */
196 
197 #ifdef RLIM_INFINITY
198     if (rl.rlim_cur == RLIM_INFINITY)
199       strcpy(strbuff, "INFINITY");
200     else
201 #endif
202       sprintf(strbuff, fmt, rl.rlim_cur);
203     fprintf(stderr, "current soft limit: %s\n", strbuff);
204 
205 #ifdef RLIM_INFINITY
206     if (rl.rlim_max == RLIM_INFINITY)
207       strcpy(strbuff, "INFINITY");
208     else
209 #endif
210       sprintf(strbuff, fmt, rl.rlim_max);
211     fprintf(stderr, "current hard limit: %s\n", strbuff);
212 
213   } /* (rl.rlim_cur != rl.rlim_max) */
214 
215   /*
216    * test 518 is all about testing libcurl functionality
217    * when more than FD_SETSIZE file descriptors are open.
218    * This means that if for any reason we are not able to
219    * open more than FD_SETSIZE file descriptors then test
220    * 518 should not be run.
221    */
222 
223   /*
224    * verify that soft limit is higher than NUM_NEEDED,
225    * which is the number of file descriptors we would
226    * try to open plus SAFETY_MARGIN to not exhaust the
227    * file descriptor pool
228    */
229 
230   num_open.rlim_cur = NUM_NEEDED;
231 
232   if ((rl.rlim_cur > 0) &&
233 #ifdef RLIM_INFINITY
234      (rl.rlim_cur != RLIM_INFINITY) &&
235 #endif
236      (rl.rlim_cur <= num_open.rlim_cur)) {
237     sprintf(strbuff2, fmt, rl.rlim_cur);
238     sprintf(strbuff1, fmt, num_open.rlim_cur);
239     sprintf(strbuff, "fds needed %s > system limit %s",
240             strbuff1, strbuff2);
241     store_errmsg(strbuff, 0);
242     fprintf(stderr, "%s\n", msgbuff);
243     return -4;
244   }
245 
246   /*
247    * reserve a chunk of memory before opening file descriptors to
248    * avoid a low memory condition once the file descriptors are
249    * open. System conditions that could make the test fail should
250    * be addressed in the precheck phase. This chunk of memory shall
251    * be always free()ed before exiting the rlimit() function so
252    * that it becomes available to the test.
253    */
254 
255   for (nitems = i = 1; nitems <= i; i *= 2)
256     nitems = i;
257   if (nitems > 0x7fff)
258     nitems = 0x40000;
259   do {
260     num_open.rlim_max = sizeof(*memchunk) * (size_t)nitems;
261     sprintf(strbuff, fmt, num_open.rlim_max);
262     fprintf(stderr, "allocating memchunk %s byte array\n", strbuff);
263     memchunk = malloc(sizeof(*memchunk) * (size_t)nitems);
264     if (!memchunk) {
265       fprintf(stderr, "memchunk, malloc() failed\n");
266       nitems /= 2;
267     }
268   } while (nitems && !memchunk);
269   if (!memchunk) {
270     store_errmsg("memchunk, malloc() failed", ERRNO);
271     fprintf(stderr, "%s\n", msgbuff);
272     return -5;
273   }
274 
275   /* initialize it to fight lazy allocation */
276 
277   fprintf(stderr, "initializing memchunk array\n");
278 
279   for (i = 0; i < nitems; i++)
280     memchunk[i] = -1;
281 
282   /* set the number of file descriptors we will try to open */
283 
284   num_open.rlim_max = NUM_OPEN;
285 
286   /* verify that we won't overflow size_t in malloc() */
287 
288   if ((size_t)(num_open.rlim_max) > ((size_t)-1) / sizeof(*fd)) {
289     sprintf(strbuff1, fmt, num_open.rlim_max);
290     sprintf(strbuff, "unable to allocate an array for %s "
291             "file descriptors, would overflow size_t", strbuff1);
292     store_errmsg(strbuff, 0);
293     fprintf(stderr, "%s\n", msgbuff);
294     free(memchunk);
295     return -6;
296   }
297 
298   /* allocate array for file descriptors */
299 
300   sprintf(strbuff, fmt, num_open.rlim_max);
301   fprintf(stderr, "allocating array for %s file descriptors\n", strbuff);
302 
303   fd = malloc(sizeof(*fd) * (size_t)(num_open.rlim_max));
304   if (!fd) {
305     store_errmsg("fd, malloc() failed", ERRNO);
306     fprintf(stderr, "%s\n", msgbuff);
307     free(memchunk);
308     return -7;
309   }
310 
311   /* initialize it to fight lazy allocation */
312 
313   fprintf(stderr, "initializing fd array\n");
314 
315   for (num_open.rlim_cur = 0;
316        num_open.rlim_cur < num_open.rlim_max;
317        num_open.rlim_cur++)
318     fd[num_open.rlim_cur] = -1;
319 
320   sprintf(strbuff, fmt, num_open.rlim_max);
321   fprintf(stderr, "trying to open %s file descriptors\n", strbuff);
322 
323   /* open a dummy descriptor */
324 
325   fd[0] = open(DEV_NULL, O_RDONLY);
326   if (fd[0] < 0) {
327     sprintf(strbuff, "opening of %s failed", DEV_NULL);
328     store_errmsg(strbuff, ERRNO);
329     fprintf(stderr, "%s\n", msgbuff);
330     free(fd);
331     fd = NULL;
332     free(memchunk);
333     return -8;
334   }
335 
336   /* create a bunch of file descriptors */
337 
338   for (num_open.rlim_cur = 1;
339        num_open.rlim_cur < num_open.rlim_max;
340        num_open.rlim_cur++) {
341 
342     fd[num_open.rlim_cur] = dup(fd[0]);
343 
344     if (fd[num_open.rlim_cur] < 0) {
345 
346       fd[num_open.rlim_cur] = -1;
347 
348       sprintf(strbuff1, fmt, num_open.rlim_cur);
349       sprintf(strbuff, "dup() attempt %s failed", strbuff1);
350       fprintf(stderr, "%s\n", strbuff);
351 
352       sprintf(strbuff1, fmt, num_open.rlim_cur);
353       sprintf(strbuff, "fds system limit seems close to %s", strbuff1);
354       fprintf(stderr, "%s\n", strbuff);
355 
356       num_open.rlim_max = NUM_NEEDED;
357 
358       sprintf(strbuff2, fmt, num_open.rlim_max);
359       sprintf(strbuff1, fmt, num_open.rlim_cur);
360       sprintf(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   sprintf(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     sprintf(strbuff, "select limit is FD_SETSIZE %d", FD_SETSIZE);
399     store_errmsg(strbuff, 0);
400     fprintf(stderr, "%s\n", msgbuff);
401     close_file_descriptors();
402     free(memchunk);
403     return -10;
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 ((fd[rl.rlim_cur] > 0) &&
411        ((unsigned int)fd[rl.rlim_cur] > num_open.rlim_cur)) {
412       sprintf(strbuff, "select limit is FD_SETSIZE %d", FD_SETSIZE);
413       store_errmsg(strbuff, 0);
414       fprintf(stderr, "%s\n", msgbuff);
415       close_file_descriptors();
416       free(memchunk);
417       return -11;
418     }
419   }
420 
421 #endif /* using a FD_SETSIZE bound select() */
422 
423   /*
424    * Old or 'backwards compatible' implementations of stdio do not allow
425    * handling of streams with an underlying file descriptor number greater
426    * than 255, even when allowing high numbered file descriptors for sockets.
427    * At this point we have a big number of file descriptors which have been
428    * opened using dup(), so lets test the stdio implementation and discover
429    * if it is capable of fopen()ing some additional files.
430    */
431 
432   if (!fopen_works()) {
433     sprintf(strbuff1, fmt, num_open.rlim_max);
434     sprintf(strbuff, "stdio fopen() fails with %s fds open()",
435             strbuff1);
436     fprintf(stderr, "%s\n", msgbuff);
437     sprintf(strbuff, "stdio fopen() fails with lots of fds open()");
438     store_errmsg(strbuff, 0);
439     close_file_descriptors();
440     free(memchunk);
441     return -12;
442   }
443 
444   /* free the chunk of memory we were reserving so that it
445      becomes becomes available to the test */
446 
447   free(memchunk);
448 
449   /* close file descriptors unless instructed to keep them */
450 
451   if (!keep_open) {
452     close_file_descriptors();
453   }
454 
455   return 0;
456 }
457 
test(char * URL)458 int test(char *URL)
459 {
460   CURLcode res;
461   CURL *curl;
462 
463   if(!strcmp(URL, "check")) {
464     /* used by the test script to ask if we can run this test or not */
465     if(rlimit(FALSE)) {
466       fprintf(stdout, "rlimit problem: %s\n", msgbuff);
467       return 1;
468     }
469     return 0; /* sure, run this! */
470   }
471 
472   if (rlimit(TRUE)) {
473     /* failure */
474     return TEST_ERR_MAJOR_BAD;
475   }
476 
477   /* run the test with the bunch of open file descriptors
478      and close them all once the test is over */
479 
480   if (curl_global_init(CURL_GLOBAL_ALL) != CURLE_OK) {
481     fprintf(stderr, "curl_global_init() failed\n");
482     close_file_descriptors();
483     return TEST_ERR_MAJOR_BAD;
484   }
485 
486   if ((curl = curl_easy_init()) == NULL) {
487     fprintf(stderr, "curl_easy_init() failed\n");
488     close_file_descriptors();
489     curl_global_cleanup();
490     return TEST_ERR_MAJOR_BAD;
491   }
492 
493   test_setopt(curl, CURLOPT_URL, URL);
494   test_setopt(curl, CURLOPT_HEADER, 1L);
495 
496   res = curl_easy_perform(curl);
497 
498 test_cleanup:
499 
500   close_file_descriptors();
501   curl_easy_cleanup(curl);
502   curl_global_cleanup();
503 
504   return (int)res;
505 }
506 
507 #else /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
508 
test(char * URL)509 int test(char *URL)
510 {
511   (void)URL;
512   printf("system lacks necessary system function(s)");
513   return 1; /* skip test */
514 }
515 
516 #endif /* defined(HAVE_GETRLIMIT) && defined(HAVE_SETRLIMIT) */
517