xref: /freebsd/lib/libc/net/gai_strerror.c (revision cb2887746f8b9dd4ad6b1e757cdc053a08b25a2e)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.
5  * 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 project 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 PROJECT 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 PROJECT 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 #include "namespace.h"
33 #include <netdb.h>
34 #if defined(NLS)
35 #include <nl_types.h>
36 #include <errno.h>
37 #include <limits.h>
38 #include <stdlib.h>
39 #include <string.h>
40 #include "reentrant.h"
41 #endif
42 #include "un-namespace.h"
43 
44 /*
45  * Entries EAI_ADDRFAMILY (1) and EAI_NODATA (7) were omitted from RFC 3493,
46  * but are or may be used as extensions or in old code.
47  */
48 static const char *const ai_errlist[] = {
49 	[0] =			"Success",
50 	[EAI_ADDRFAMILY] =	"Address family for hostname not supported",
51 	[EAI_AGAIN] =		"Name could not be resolved at this time",
52 	[EAI_BADFLAGS] =	"Flags parameter had an invalid value",
53 	[EAI_FAIL] =		"Non-recoverable failure in name resolution",
54 	[EAI_FAMILY] =		"Address family not recognized",
55 	[EAI_MEMORY] =		"Memory allocation failure",
56 	[EAI_NODATA] =		"No address associated with hostname",
57 	[EAI_NONAME] =		"Name does not resolve",
58 	[EAI_SERVICE] =		"Service was not recognized for socket type",
59 	[EAI_SOCKTYPE] =	"Intended socket type was not recognized",
60 	[EAI_SYSTEM] =		"System error returned in errno",
61 	[EAI_BADHINTS] =	"Invalid value for hints",
62 	[EAI_PROTOCOL] =	"Resolved protocol is unknown",
63 	[EAI_OVERFLOW] =	"Argument buffer overflow",
64 };
65 
66 #if defined(NLS)
67 static char		gai_buf[NL_TEXTMAX];
68 static once_t		gai_init_once = ONCE_INITIALIZER;
69 static thread_key_t	gai_key;
70 static int		gai_keycreated = 0;
71 
72 static void
73 gai_keycreate(void)
74 {
75 	gai_keycreated = thr_keycreate(&gai_key, free) == 0;
76 }
77 #endif
78 
79 const char *
80 gai_strerror(int ecode)
81 {
82 #if defined(NLS)
83 	nl_catd catd;
84 	char *buf;
85 	int saved_errno;
86 
87 	saved_errno = errno;
88 	if (thr_main() != 0)
89 		buf = gai_buf;
90 	else {
91 		if (thr_once(&gai_init_once, gai_keycreate) != 0 ||
92 		    !gai_keycreated)
93 			goto thr_err;
94 		if ((buf = thr_getspecific(gai_key)) == NULL) {
95 			if ((buf = malloc(sizeof(gai_buf))) == NULL)
96 				goto thr_err;
97 			if (thr_setspecific(gai_key, buf) != 0) {
98 				free(buf);
99 				goto thr_err;
100 			}
101 		}
102 	}
103 
104 	catd = catopen("libc", NL_CAT_LOCALE);
105 	if (ecode > 0 && ecode < EAI_MAX)
106 		strlcpy(buf, catgets(catd, 3, ecode, ai_errlist[ecode]),
107 		    sizeof(gai_buf));
108 	else if (ecode == 0)
109 		strlcpy(buf, catgets(catd, 3, NL_MSGMAX - 1, "Success"),
110 		    sizeof(gai_buf));
111 	else
112 		strlcpy(buf, catgets(catd, 3, NL_MSGMAX, "Unknown error"),
113 		    sizeof(gai_buf));
114 	catclose(catd);
115 	errno = saved_errno;
116 	return (buf);
117 
118 thr_err:
119 	errno = saved_errno;
120 #endif
121 	if (ecode >= 0 && ecode < EAI_MAX)
122 		return (ai_errlist[ecode]);
123 	return ("Unknown error");
124 }
125