1 /*-
2 * Copyright (c) 2007 Peter Wemm
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24 * SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 __FBSDID("$FreeBSD: stable/10/lib/libc/gen/__getosreldate.c 211416 2010-08-17 09:13:26Z kib $");
29
30 #include <sys/param.h>
31 #include <sys/sysctl.h>
32 #include <errno.h>
33 #include <link.h>
34 #include "libc_private.h"
35
36 int __getosreldate(void);
37
38 /*
39 * This is private to libc. It is intended for wrapping syscall stubs in order
40 * to avoid having to put SIGSYS signal handlers in place to test for presence
41 * of new syscalls. This caches the result in order to be as quick as possible.
42 *
43 * Use getosreldate(3) for public use as it respects the $OSVERSION environment
44 * variable.
45 */
46
47 int
__getosreldate(void)48 __getosreldate(void)
49 {
50 static int osreldate;
51 size_t len;
52 int oid[2];
53 int error, osrel;
54
55 if (osreldate != 0)
56 return (osreldate);
57
58 error = _elf_aux_info(AT_OSRELDATE, &osreldate, sizeof(osreldate));
59 if (error == 0 && osreldate != 0)
60 return (osreldate);
61
62 oid[0] = CTL_KERN;
63 oid[1] = KERN_OSRELDATE;
64 osrel = 0;
65 len = sizeof(osrel);
66 error = sysctl(oid, 2, &osrel, &len, NULL, 0);
67 if (error == 0 && osrel > 0 && len == sizeof(osrel))
68 osreldate = osrel;
69 return (osreldate);
70 }
71