/*
 * Copyright (C) 2009  Internet Systems Consortium, Inc. ("ISC")
 *
 * Permission to use, copy, modify, and/or 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 1.5 2009-09-02 23:48:02 tbox Exp $ */

/*! \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 <config.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()
 */
IRS_GAISTRERROR_RETURN_T
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);
}