1 /*        $NetBSD: herror.c,v 1.10 2015/02/24 17:56:20 christos Exp $ */
2 
3 /*
4  * Copyright (c) 1987, 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 /*
33  * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
34  * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
35  *
36  * Permission to use, copy, modify, and distribute this software for any
37  * purpose with or without fee is hereby granted, provided that the above
38  * copyright notice and this permission notice appear in all copies.
39  *
40  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
41  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
42  * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
43  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
44  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
45  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
46  * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
47  */
48 
49 #include <sys/cdefs.h>
50 #if defined(LIBC_SCCS) && !defined(lint)
51 #ifdef notdef
52 static const char sccsid[] = "@(#)herror.c        8.1 (Berkeley) 6/4/93";
53 static const char rcsid[] = "Id: herror.c,v 1.4 2005/04/27 04:56:41 sra Exp";
54 #else
55 __RCSID("$NetBSD: herror.c,v 1.10 2015/02/24 17:56:20 christos Exp $");
56 #endif
57 #endif /* LIBC_SCCS and not lint */
58 
59 #include "port_before.h"
60 
61 #include "namespace.h"
62 #include <sys/types.h>
63 #include <sys/param.h>
64 #include <sys/uio.h>
65 
66 #include <netinet/in.h>
67 #include <arpa/nameser.h>
68 
69 #include <netdb.h>
70 #include <resolv.h>
71 #include <string.h>
72 #include <unistd.h>
73 
74 #include "port_after.h"
75 
76 const char *h_errlist[] = {
77           "Resolver Error 0 (no error)",
78           "Unknown host",                                   /*%< 1 HOST_NOT_FOUND */
79           "Host name lookup failure",             /*%< 2 TRY_AGAIN */
80           "Unknown server error",                           /*%< 3 NO_RECOVERY */
81           "No address associated with name",      /*%< 4 NO_ADDRESS */
82 };
83 int       h_nerr = { sizeof h_errlist / sizeof h_errlist[0] };
84 
85 #if !(__GLIBC__ > 2 || __GLIBC__ == 2 &&  __GLIBC_MINOR__ >= 3)
86 #undef    h_errno
87 int       h_errno;
88 #endif
89 
90 #ifdef __weak_alias
__weak_alias(herror,_herror)91 __weak_alias(herror,_herror)
92 #endif
93 
94 /*%
95  * herror --
96  *        print the error indicated by the h_errno value.
97  */
98 void
99 herror(const char *s) {
100           struct iovec iov[4], *v = iov;
101           char *t;
102 
103           if (s != NULL && *s != '\0') {
104                     DE_CONST(s, t);
105                     v->iov_base = t;
106                     v->iov_len = strlen(t);
107                     v++;
108                     DE_CONST(": ", t);
109                     v->iov_base = t;
110                     v->iov_len = 2;
111                     v++;
112           }
113           DE_CONST(hstrerror(*__h_errno()), t);
114           v->iov_base = t;
115           v->iov_len = strlen(v->iov_base);
116           v++;
117           DE_CONST("\n", t);
118           v->iov_base = t;
119           v->iov_len = 1;
120           (void)writev(STDERR_FILENO, iov, (int)((v - iov) + 1));
121 }
122 
123 /*%
124  * hstrerror --
125  *        return the string associated with a given "host" errno value.
126  */
127 const char *
hstrerror(int err)128 hstrerror(int err) {
129           if (err < 0)
130                     return ("Resolver internal error");
131           else if (err < h_nerr)
132                     return (h_errlist[err]);
133           return ("Unknown resolver error");
134 }
135 
136 /*! \file */
137