isc_strerror.c revision 256281 
1/*
2 * Copyright (C) 2001  Internet Software Consortium.
3 *
4 * Permission to use, copy, modify, and distribute this software for any
5 * purpose with or without fee is hereby granted, provided that the above
6 * copyright notice and this permission notice appear in all copies.
7 *
8 * THE SOFTWARE IS PROVIDED "AS IS" AND INTERNET SOFTWARE CONSORTIUM
9 * DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL
10 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL
11 * INTERNET SOFTWARE CONSORTIUM BE LIABLE FOR ANY SPECIAL, DIRECT,
12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING
13 * FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT,
14 * NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
15 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16 */
17
18/* $Id: strerror.c,v 1.3 2001/11/20 01:45:45 gson Exp $ */
19
20#include <config.h>
21
22#include <stdio.h>
23#include <string.h>
24
25#include <isc/mutex.h>
26#include <isc/once.h>
27#include <isc/print.h>
28#include <isc/strerror.h>
29#include <isc/util.h>
30
31#include "l_stdlib.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 = 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 = 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}
75