1/*	$NetBSD: getdtablesize.c,v 1.1.1.1 2011/04/13 18:15:41 elric Exp $	*/
2
3/*
4 * Copyright (c) 1995-2001 Kungliga Tekniska Högskolan
5 * (Royal Institute of Technology, Stockholm, Sweden).
6 * All rights reserved.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 *
15 * 2. Redistributions in binary form must reproduce the above copyright
16 *    notice, this list of conditions and the following disclaimer in the
17 *    documentation and/or other materials provided with the distribution.
18 *
19 * 3. Neither the name of the Institute nor the names of its contributors
20 *    may be used to endorse or promote products derived from this software
21 *    without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33 * SUCH DAMAGE.
34 */
35
36#include <config.h>
37
38#include <krb5/roken.h>
39
40#ifdef HAVE_SYS_TYPES_H
41#include <sys/types.h>
42#endif
43#ifdef TIME_WITH_SYS_TIME
44#include <sys/time.h>
45#include <time.h>
46#elif defined(HAVE_SYS_TIME_H)
47#include <sys/time.h>
48#else
49#include <time.h>
50#endif
51#ifdef HAVE_SYS_PARAM_H
52#include <sys/param.h>
53#endif
54#ifdef HAVE_UNISTD_H
55#include <unistd.h>
56#endif
57
58#ifdef HAVE_SYS_RESOURCE_H
59#include <sys/resource.h>
60#endif
61
62#ifdef HAVE_SYS_SYSCTL_H
63#include <sys/sysctl.h>
64#endif
65
66ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
67getdtablesize(void)
68{
69  int files = -1;
70#if defined(HAVE_SYSCONF) && defined(_SC_OPEN_MAX)
71  files = sysconf(_SC_OPEN_MAX);
72#else /* !defined(HAVE_SYSCONF) */
73#if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
74  struct rlimit res;
75  if (getrlimit(RLIMIT_NOFILE, &res) == 0)
76    files = res.rlim_cur;
77#else /* !definded(HAVE_GETRLIMIT) */
78#if defined(HAVE_SYSCTL) && defined(CTL_KERN) && defined(KERN_MAXFILES)
79  int mib[2];
80  size_t len;
81
82  mib[0] = CTL_KERN;
83  mib[1] = KERN_MAXFILES;
84  len = sizeof(files);
85  sysctl(&mib, 2, &files, sizeof(files), NULL, 0);
86#endif /* defined(HAVE_SYSCTL) */
87#endif /* !definded(HAVE_GETRLIMIT) */
88#endif /* !defined(HAVE_SYSCONF) */
89
90#ifdef OPEN_MAX
91  if (files < 0)
92    files = OPEN_MAX;
93#endif
94
95#ifdef NOFILE
96  if (files < 0)
97    files = NOFILE;
98#endif
99
100  return files;
101}
102