herror.c revision 270838 
1/*
2 * Copyright (c) 1987, 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 * 4. 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/*
31 * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC")
32 * Portions Copyright (c) 1996-1999 by Internet Software Consortium.
33 *
34 * Permission to use, copy, modify, and distribute this software for any
35 * purpose with or without fee is hereby granted, provided that the above
36 * copyright notice and this permission notice appear in all copies.
37 *
38 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
39 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
40 * MERCHANTABILITY AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR
41 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
42 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
43 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
44 * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
45 */
46
47#if defined(LIBC_SCCS) && !defined(lint)
48static const char sccsid[] = "@(#)herror.c	8.1 (Berkeley) 6/4/93";
49static const char rcsid[] = "$Id: herror.c,v 1.4 2005/04/27 04:56:41 sra Exp $";
50#endif /* LIBC_SCCS and not lint */
51#include <sys/cdefs.h>
52__FBSDID("$FreeBSD: stable/10/lib/libc/resolv/herror.c 270838 2014-08-30 10:16:25Z ume $");
53
54#include "port_before.h"
55
56#include "namespace.h"
57#include <sys/types.h>
58#include <sys/param.h>
59#include <sys/uio.h>
60
61#include <netinet/in.h>
62#include <arpa/nameser.h>
63
64#include <netdb.h>
65#include <resolv.h>
66#include <string.h>
67#include <unistd.h>
68#include "un-namespace.h"
69
70#include "port_after.h"
71
72const char *h_errlist[] = {
73	"Resolver Error 0 (no error)",
74	"Unknown host",				/*%< 1 HOST_NOT_FOUND */
75	"Host name lookup failure",		/*%< 2 TRY_AGAIN */
76	"Unknown server error",			/*%< 3 NO_RECOVERY */
77	"No address associated with name",	/*%< 4 NO_ADDRESS */
78};
79const int h_nerr = { sizeof h_errlist / sizeof h_errlist[0] };
80
81#undef	h_errno
82int	h_errno;
83
84/*%
85 * herror --
86 *	print the error indicated by the h_errno value.
87 */
88void
89herror(const char *s) {
90	struct iovec iov[4], *v = iov;
91	char *t;
92
93	if (s != NULL && *s != '\0') {
94		DE_CONST(s, t);
95		v->iov_base = t;
96		v->iov_len = strlen(t);
97		v++;
98		DE_CONST(": ", t);
99		v->iov_base = t;
100		v->iov_len = 2;
101		v++;
102	}
103	DE_CONST(hstrerror(*__h_errno()), t);
104	v->iov_base = t;
105	v->iov_len = strlen(v->iov_base);
106	v++;
107	DE_CONST("\n", t);
108	v->iov_base = t;
109	v->iov_len = 1;
110	_writev(STDERR_FILENO, iov, (v - iov) + 1);
111}
112
113/*%
114 * hstrerror --
115 *	return the string associated with a given "host" errno value.
116 */
117const char *
118hstrerror(int err) {
119	if (err < 0)
120		return ("Resolver internal error");
121	else if (err < h_nerr)
122		return (h_errlist[err]);
123	return ("Unknown resolver error");
124}
125
126/*! \file */
127