xref: /freebsd/lib/libc/string/strerror.c (revision 3bdf775801b218aa5a89564839405b122f4b233e)
1 /*-
2  * Copyright (c) 1988, 1993
3  *	The Regents of the University of California.  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  * 3. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #if defined(LIBC_SCCS) && !defined(lint)
31 static char sccsid[] = "@(#)strerror.c	8.1 (Berkeley) 6/4/93";
32 #endif /* LIBC_SCCS and not lint */
33 #include <sys/cdefs.h>
34 __FBSDID("$FreeBSD$");
35 
36 #if defined(NLS)
37 #include <nl_types.h>
38 #endif
39 
40 #include <limits.h>
41 #include <errno.h>
42 #include <string.h>
43 #include <stdio.h>
44 
45 #include "errlst.h"
46 
47 #define	UPREFIX		"Unknown error"
48 
49 /*
50  * Define a buffer size big enough to describe a 64-bit signed integer
51  * converted to ASCII decimal (19 bytes), with an optional leading sign
52  * (1 byte); finally, we get the prefix, delimiter (": ") and a trailing
53  * NUL from UPREFIX.
54  */
55 #define	EBUFSIZE	(20 + 2 + sizeof(UPREFIX))
56 
57 /*
58  * Doing this by hand instead of linking with stdio(3) avoids bloat for
59  * statically linked binaries.
60  */
61 static void
62 errstr(int num, char *uprefix, char *buf, size_t len)
63 {
64 	char *t;
65 	unsigned int uerr;
66 	char tmp[EBUFSIZE];
67 
68 	t = tmp + sizeof(tmp);
69 	*--t = '\0';
70 	uerr = (num >= 0) ? num : -num;
71 	do {
72 		*--t = "0123456789"[uerr % 10];
73 	} while (uerr /= 10);
74 	if (num < 0)
75 		*--t = '-';
76 	*--t = ' ';
77 	*--t = ':';
78 	strlcpy(buf, uprefix, len);
79 	strlcat(buf, t, len);
80 }
81 
82 int
83 strerror_r(int errnum, char *strerrbuf, size_t buflen)
84 {
85 	int retval = 0;
86 #if defined(NLS)
87 	int saved_errno = errno;
88 	nl_catd catd;
89 	catd = catopen("libc", NL_CAT_LOCALE);
90 #endif
91 
92 	if (errnum < 0 || errnum >= __hidden_sys_nerr) {
93 		errstr(errnum,
94 #if defined(NLS)
95 			catgets(catd, 1, 0xffff, UPREFIX),
96 #else
97 			UPREFIX,
98 #endif
99 			strerrbuf, buflen);
100 		retval = EINVAL;
101 	} else {
102 		if (strlcpy(strerrbuf,
103 #if defined(NLS)
104 			catgets(catd, 1, errnum, __hidden_sys_errlist[errnum]),
105 #else
106 			__hidden_sys_errlist[errnum],
107 #endif
108 			buflen) >= buflen)
109 		retval = ERANGE;
110 	}
111 
112 #if defined(NLS)
113 	catclose(catd);
114 	errno = saved_errno;
115 #endif
116 
117 	return (retval);
118 }
119 
120 char *
121 strerror(int num)
122 {
123 	static char ebuf[NL_TEXTMAX];
124 
125 	if (strerror_r(num, ebuf, sizeof(ebuf)) != 0)
126 		errno = EINVAL;
127 	return (ebuf);
128 }
129