xref: /freebsd/crypto/heimdal/lib/roken/getdtablesize.c (revision 1669d8afc64812c8d2d1d147ae1fd42ff441e1b1)
1 /*
2  * Copyright (c) 1995-2001 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #ifdef HAVE_CONFIG_H
35 #include <config.h>
36 RCSID("$Id: getdtablesize.c,v 1.11 2001/06/20 00:00:38 joda Exp $");
37 #endif
38 
39 #include "roken.h"
40 
41 #ifdef HAVE_SYS_TYPES_H
42 #include <sys/types.h>
43 #endif
44 #ifdef TIME_WITH_SYS_TIME
45 #include <sys/time.h>
46 #include <time.h>
47 #elif defined(HAVE_SYS_TIME_H)
48 #include <sys/time.h>
49 #else
50 #include <time.h>
51 #endif
52 #ifdef HAVE_SYS_PARAM_H
53 #include <sys/param.h>
54 #endif
55 #ifdef HAVE_UNISTD_H
56 #include <unistd.h>
57 #endif
58 
59 #ifdef HAVE_SYS_RESOURCE_H
60 #include <sys/resource.h>
61 #endif
62 
63 #ifdef HAVE_SYS_SYSCTL_H
64 #include <sys/sysctl.h>
65 #endif
66 
67 int getdtablesize(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