/*	$NetBSD: gai_strerror.c,v 1.6 2022/09/23 12:15:32 christos Exp $	*/

/*
 * Copyright (C) Internet Systems Consortium, Inc. ("ISC")
 *
 * SPDX-License-Identifier: MPL-2.0
 *
 * This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0.  If a copy of the MPL was not distributed with this
 * file, you can obtain one at https://mozilla.org/MPL/2.0/.
 *
 * See the COPYRIGHT file distributed with this work for additional
 * information regarding copyright ownership.
 */

/*! \file gai_strerror.c
 * gai_strerror() returns an error message corresponding to an
 * error code returned by getaddrinfo() and getnameinfo(). The following error
 * codes and their meaning are defined in
 * \link netdb.h include/irs/netdb.h.\endlink
 * This implementation is almost an exact copy of lwres/gai_sterror.c except
 * that it catches up the latest API standard, RFC3493.
 *
 * \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 (obsoleted in RFC3493)
 * \li #EAI_NONAME hostname nor servname 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
 * \li #EAI_BADHINTS Invalid value for hints (non-standard)
 * \li #EAI_PROTOCOL Resolved protocol is unknown (non-standard)
 * \li #EAI_OVERFLOW Argument buffer overflow
 * \li #EAI_INSECUREDATA Insecure Data (experimental)
 *
 * 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(), getaddrinfo(), getnameinfo(), RFC3493.
 */

#include <isc/net.h>

#include <irs/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",
				      "argument buffer overflow",
				      "insecure data provided" };

/*%
 * Returns an error message corresponding to an error code returned by
 * getaddrinfo() and getnameinfo()
 */
#if defined _WIN32
char *
#else  /* if defined _WIN32 */
const char *
#endif /* if defined _WIN32 */
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);
}