/contrib/bind9/lib/isc/unix/strerror.c

 1/*
 2 * Copyright (C) 2004, 2005, 2007, 2009  Internet Systems Consortium, Inc. ("ISC")
 3 * Copyright (C) 2001  Internet Software Consortium.
 4 *
 5 * Permission to use, copy, modify, and/or distribute this software for any
 6 * purpose with or without fee is hereby granted, provided that the above
 7 * copyright notice and this permission notice appear in all copies.
 8 *
 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
11 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
15 * PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: strerror.c,v 1.10 2009/02/16 23:48:04 tbox Exp $ */
19
20/*! \file */
21
22#include <config.h>
23
24#include <stdio.h>
25#include <string.h>
26
27#include <isc/mutex.h>
28#include <isc/once.h>
29#include <isc/print.h>
30#include <isc/strerror.h>
31#include <isc/util.h>
32
33#ifdef HAVE_STRERROR
34/*%
35 * We need to do this this way for profiled locks.
36 */
37static isc_mutex_t isc_strerror_lock;
38static void init_lock(void) {
39	RUNTIME_CHECK(isc_mutex_init(&isc_strerror_lock) == ISC_R_SUCCESS);
40}
41#else
42extern const char * const sys_errlist[];
43extern const int sys_nerr;
44#endif
45
46void
47isc__strerror(int num, char *buf, size_t size) {
48#ifdef HAVE_STRERROR
49	char *msg;
50	unsigned int unum = (unsigned int)num;
51	static isc_once_t once = ISC_ONCE_INIT;
52
53	REQUIRE(buf != NULL);
54
55	RUNTIME_CHECK(isc_once_do(&once, init_lock) == ISC_R_SUCCESS);
56
57	LOCK(&isc_strerror_lock);
58	msg = strerror(num);
59	if (msg != NULL)
60		snprintf(buf, size, "%s", msg);
61	else
62		snprintf(buf, size, "Unknown error: %u", unum);
63	UNLOCK(&isc_strerror_lock);
64#else
65	unsigned int unum = (unsigned int)num;
66
67	REQUIRE(buf != NULL);
68
69	if (num >= 0 && num < sys_nerr)
70		snprintf(buf, size, "%s", sys_errlist[num]);
71	else
72		snprintf(buf, size, "Unknown error: %u", unum);
73#endif
74}