xref: /freebsd/lib/libc/resolv/herror.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: (BSD-3-Clause AND ISC)
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 "port_before.h"
50 
51 #include "namespace.h"
52 #include <sys/param.h>
53 #include <sys/uio.h>
54 
55 #include <netinet/in.h>
56 #include <arpa/nameser.h>
57 
58 #include <netdb.h>
59 #include <resolv.h>
60 #include <string.h>
61 #include <unistd.h>
62 #include "un-namespace.h"
63 
64 #include "port_after.h"
65 
66 const char *h_errlist[] = {
67 	"Resolver Error 0 (no error)",
68 	"Unknown host",				/*%< 1 HOST_NOT_FOUND */
69 	"Host name lookup failure",		/*%< 2 TRY_AGAIN */
70 	"Unknown server error",			/*%< 3 NO_RECOVERY */
71 	"No address associated with name",	/*%< 4 NO_ADDRESS */
72 };
73 const int h_nerr = { nitems(h_errlist) };
74 
75 #undef	h_errno
76 int	h_errno;
77 
78 /*%
79  * herror --
80  *	print the error indicated by the h_errno value.
81  */
82 void
83 herror(const char *s) {
84 	struct iovec iov[4], *v = iov;
85 	char *t;
86 
87 	if (s != NULL && *s != '\0') {
88 		DE_CONST(s, t);
89 		v->iov_base = t;
90 		v->iov_len = strlen(t);
91 		v++;
92 		DE_CONST(": ", t);
93 		v->iov_base = t;
94 		v->iov_len = 2;
95 		v++;
96 	}
97 	DE_CONST(hstrerror(*__h_errno()), t);
98 	v->iov_base = t;
99 	v->iov_len = strlen(v->iov_base);
100 	v++;
101 	DE_CONST("\n", t);
102 	v->iov_base = t;
103 	v->iov_len = 1;
104 	_writev(STDERR_FILENO, iov, (v - iov) + 1);
105 }
106 
107 /*%
108  * hstrerror --
109  *	return the string associated with a given "host" errno value.
110  */
111 const char *
112 hstrerror(int err) {
113 	if (err < 0)
114 		return ("Resolver internal error");
115 	else if (err < h_nerr)
116 		return (h_errlist[err]);
117 	return ("Unknown resolver error");
118 }
119 
120 /*! \file */
121