gai_strerror.c

来自「非常好的dns解析软件」· C语言 代码 · 共 84 行

/*
 * Copyright (C) 2004-2006  Internet Systems Consortium, Inc. ("ISC")
 * Copyright (C) 2000, 2001  Internet Software Consortium.
 *
 * Permission to use, copy, modify, and distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
 * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
 * PERFORMANCE OF THIS SOFTWARE.
 */

/* $Id: gai_strerror.c,v 1.16.18.4 2006/08/25 05:25:51 marka Exp $ */

/*! \file gai_strerror.c
 * lwres_gai_strerror() returns an error message corresponding to an
 * error code returned by getaddrinfo(). The following error codes and
 * their meaning are defined in \link netdb.h include/lwres/netdb.h.\endlink
 *
 * \li #EAI_ADDRFAMILY address family for hostname not supported
 * \li #EAI_AGAIN temporary failure in name resolution
 * \li #EAI_BADFLAGS invalid value for #ai_flags
 * \li #EAI_FAIL non-recoverable failure in name resolution
 * \li #EAI_FAMILY ai_family not supported
 * \li #EAI_MEMORY memory allocation failure
 * \li #EAI_NODATA no address associated with hostname
 * \li #EAI_NONAME hostname or servname not provided, or not known
 * \li #EAI_SERVICE servname not supported for ai_socktype
 * \li #EAI_SOCKTYPE ai_socktype not supported
 * \li #EAI_SYSTEM system error returned in errno
 *
 * The message invalid error code is returned if ecode is out of range.
 *
 * ai_flags, ai_family and ai_socktype are elements of the struct
 * addrinfo used by lwres_getaddrinfo().
 *
 * \section gai_strerror_see See Also
 *
 * strerror, lwres_getaddrinfo(), getaddrinfo(), RFC2133.
 */

#include <config.h>

#include <lwres/netdb.h>

/*% Text of error messages. */
static const char *gai_messages[] = {
	"no error",
	"address family for hostname not supported",
	"temporary failure in name resolution",
	"invalid value for ai_flags",
	"non-recoverable failure in name resolution",
	"ai_family not supported",
	"memory allocation failure",
	"no address associated with hostname",
	"hostname nor servname provided, or not known",
	"servname not supported for ai_socktype",
	"ai_socktype not supported",
	"system error returned in errno",
	"bad hints",
	"bad protocol"
};

/*% Returns an error message corresponding to an error code returned by getaddrinfo() */
char *
lwres_gai_strerror(int ecode) {
	union {
		const char *const_ptr;
		char *deconst_ptr;
	} ptr;

	if ((ecode < 0) ||
	    (ecode >= (int)(sizeof(gai_messages)/sizeof(*gai_messages))))
		ptr.const_ptr = "invalid error code";
	else
		ptr.const_ptr = gai_messages[ecode];
	return (ptr.deconst_ptr);
}