none/tests/rlimit_nofile.c

   1 #include <errno.h>
   2 #include <fcntl.h>
   3 #include <stdio.h>
   4 #include <stdlib.h>
   5 #include <sys/resource.h>
   6 #include <unistd.h>
   7 #include "fdleak.h"
   8
   9 int main(int argc, char **argv)
  10 {
  11    struct rlimit oldrlim;
  12    struct rlimit newrlim;
  13    int fd;
  14
  15    CLOSE_INHERITED_FDS;
  16
  17    if (getrlimit(RLIMIT_NOFILE, &oldrlim) < 0)
  18    {
  19       perror("getrlimit");
  20       exit(1);
  21    }
  22
  23    newrlim.rlim_cur = oldrlim.rlim_max+1;
  24    newrlim.rlim_max = oldrlim.rlim_max;
  25    if (setrlimit(RLIMIT_NOFILE, &newrlim) == -1)
  26    {
  27       if (errno != EINVAL) {
  28          fprintf(stderr, "setrlimit exceeding hardlimit must set errno=EINVAL\n");
  29          exit(1);
  30       }
  31    }
  32    else
  33    {
  34         fprintf(stderr, "setrlimit exceeding hardlimit must return -1\n");
  35         exit(1);
  36    }
  37
  38    newrlim.rlim_cur = oldrlim.rlim_max;
  39    newrlim.rlim_max = oldrlim.rlim_max+1;
  40    if (setrlimit(RLIMIT_NOFILE, &newrlim) == -1)
  41    {
  42       if (errno != EPERM) {
  43          fprintf(stderr, "setrlimit changing hardlimit must set errno=EPERM\n");
  44          exit(1);
  45       }
  46    }
  47    else
  48    {
  49         fprintf(stderr, "setrlimit changing hardlimit must return -1\n");
  50         exit(1);
  51    }
  52
  53    newrlim.rlim_cur = oldrlim.rlim_cur / 2;
  54    newrlim.rlim_max = oldrlim.rlim_max;
  55
  56    if (setrlimit(RLIMIT_NOFILE, &newrlim) < 0)
  57    {
  58       perror("setrlimit");
  59       exit(1);
  60    }
  61
  62    if (getrlimit(RLIMIT_NOFILE, &newrlim) < 0)
  63    {
  64       perror("getrlimit");
  65       exit(1);
  66    }
  67
  68    if (newrlim.rlim_cur != oldrlim.rlim_cur / 2)
  69    {
  70       fprintf(stderr, "rlim_cur is %llu (should be %llu)\n",
  71               (unsigned long long)newrlim.rlim_cur,
  72               (unsigned long long)oldrlim.rlim_cur / 2);
  73    }
  74
  75    if (newrlim.rlim_max != oldrlim.rlim_max)
  76    {
  77       fprintf(stderr, "rlim_max is %llu (should be %llu)\n",
  78               (unsigned long long)newrlim.rlim_max,
  79               (unsigned long long)oldrlim.rlim_max);
  80    }
  81
  82    newrlim.rlim_cur -= 3; /* allow for stdin, stdout and stderr */
  83
  84    while (newrlim.rlim_cur-- > 0)
  85    {
  86       if (open("/dev/null", O_RDONLY) < 0)
  87       {
  88          perror("open");
  89       }
  90    }
  91
  92    if ((fd = open("/dev/null", O_RDONLY)) >= 0)
  93    {
  94       fprintf(stderr, "open succeeded with fd %d - it should have failed!\n", fd);
  95    }
  96    else if (errno != EMFILE)
  97    {
  98       perror("open");
  99    }
 100
 101    /* We used to test setrlimit(RLIMIT_NOFILE, NULL) -1 || errno != EFAULT,
 102       but glibc doesn't give any guarantees that won't just crash, in
 103       newer versions it just silently succeeds... See bug #385912. */
 104
 105    exit(0);
 106 }