strerror.c revision 330897 
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
3 *
4 * Copyright (c) 1988, 1993
5 *	The Regents of the University of California.  All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#if defined(LIBC_SCCS) && !defined(lint)
33static char sccsid[] = "@(#)strerror.c	8.1 (Berkeley) 6/4/93";
34#endif /* LIBC_SCCS and not lint */
35#include <sys/cdefs.h>
36__FBSDID("$FreeBSD: stable/11/lib/libc/string/strerror.c 330897 2018-03-14 03:19:51Z eadler $");
37
38#if defined(NLS)
39#include <nl_types.h>
40#endif
41
42#include <limits.h>
43#include <errno.h>
44#include <string.h>
45#include <stdio.h>
46
47#include "errlst.h"
48
49#define	UPREFIX		"Unknown error"
50
51/*
52 * Define a buffer size big enough to describe a 64-bit signed integer
53 * converted to ASCII decimal (19 bytes), with an optional leading sign
54 * (1 byte); finally, we get the prefix, delimiter (": ") and a trailing
55 * NUL from UPREFIX.
56 */
57#define	EBUFSIZE	(20 + 2 + sizeof(UPREFIX))
58
59/*
60 * Doing this by hand instead of linking with stdio(3) avoids bloat for
61 * statically linked binaries.
62 */
63static void
64errstr(int num, char *uprefix, char *buf, size_t len)
65{
66	char *t;
67	unsigned int uerr;
68	char tmp[EBUFSIZE];
69
70	t = tmp + sizeof(tmp);
71	*--t = '\0';
72	uerr = (num >= 0) ? num : -num;
73	do {
74		*--t = "0123456789"[uerr % 10];
75	} while (uerr /= 10);
76	if (num < 0)
77		*--t = '-';
78	*--t = ' ';
79	*--t = ':';
80	strlcpy(buf, uprefix, len);
81	strlcat(buf, t, len);
82}
83
84int
85strerror_r(int errnum, char *strerrbuf, size_t buflen)
86{
87	int retval = 0;
88#if defined(NLS)
89	int saved_errno = errno;
90	nl_catd catd;
91	catd = catopen("libc", NL_CAT_LOCALE);
92#endif
93
94	if (errnum < 0 || errnum >= __hidden_sys_nerr) {
95		errstr(errnum,
96#if defined(NLS)
97			catgets(catd, 1, 0xffff, UPREFIX),
98#else
99			UPREFIX,
100#endif
101			strerrbuf, buflen);
102		retval = EINVAL;
103	} else {
104		if (strlcpy(strerrbuf,
105#if defined(NLS)
106			catgets(catd, 1, errnum, __hidden_sys_errlist[errnum]),
107#else
108			__hidden_sys_errlist[errnum],
109#endif
110			buflen) >= buflen)
111		retval = ERANGE;
112	}
113
114#if defined(NLS)
115	catclose(catd);
116	errno = saved_errno;
117#endif
118
119	return (retval);
120}
121
122char *
123strerror(int num)
124{
125	static char ebuf[NL_TEXTMAX];
126
127	if (strerror_r(num, ebuf, sizeof(ebuf)) != 0)
128		errno = EINVAL;
129	return (ebuf);
130}
131