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				2	.\" Copyright 2005 by Dominick Meglio.
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				13	.\" this software for any purpose. It is provided "as is"
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				16	.TH ARES_GETNAMEINFO 3 "1 May 2009"
				17	.SH NAME
				18	ares_getnameinfo \- Address-to-nodename translation in protocol-independent manner
				19	.SH SYNOPSIS
				20	.nf
				21	.B #include <ares.h>
				22	.PP
				23	.B typedef void (ares_nameinfo_callback)(void \fIarg\fP, int \fIstatus\fP,
				24	.B int \fItimeouts\fP, char \fInode\fP, char \fIservice\fP)
				25	.PP
				26	.B void ares_getnameinfo(ares_channel \fIchannel\fP, const struct sockaddr *\fIsa\fP,
				27	.B ares_socklen_t \fIsalen\fP, int \fIflags\fP, ares_nameinfo_callback \fIcallback\fP,
				28	.B void *\fIarg\fP)
				29	.fi
				30	.SH DESCRIPTION
				31	The
				32	.B ares_getnameinfo
				33	function is defined for protocol-independent address translation. The function
				34	is a combination of \fIares_gethostbyaddr(3)\fP and \fIgetservbyport(3)\fP. The function will
				35	translate the address either by executing a host query on the name service channel
				36	identified by
				37	.IR channel
				38	or it will attempt to resolve it locally if possible.
				39	The parameters
				40	.I sa
				41	and
				42	.I len
				43	give the address as a sockaddr structure, and
				44	.I flags
				45	gives the options that the function will use. Valid flags are listed below:
				46	.TP 19
				47	.B ARES_NI_NOFQDN
				48	Only the nodename portion of the FQDN is returned for local hosts.
				49	.TP 19
				50	.B ARES_NI_NUMERICHOST
				51	The numeric form of the hostname is returned rather than the name.
				52	.TP 19
				53	.B ARES_NI_NAMEREQD
				54	An error is returned if the hostname cannot be found in the DNS.
				55	.TP 19
				56	.B ARES_NI_NUMERICSERV
				57	The numeric form of the service is returned rather than the name.
				58	.TP 19
				59	.B ARES_NI_TCP
				60	The service name is to be looked up for the TCP protocol.
				61	.TP 19
				62	.B ARES_NI_UDP
				63	The service name is to be looked up for the UDP protocol.
				64	.TP 19
				65	.B ARES_NI_SCTP
				66	The service name is to be looked up for the SCTP protocol.
				67	.TP 19
				68	.B ARES_NI_DCCP
				69	The service name is to be looked up for the DCCP protocol.
				70	.TP 19
				71	.B ARES_NI_NUMERICSCOPE
				72	The numeric form of the scope ID is returned rather than the name.
				73	.TP 19
				74	.B ARES_NI_LOOKUPHOST
				75	A hostname lookup is being requested.
				76	.TP 19
				77	.B ARES_NI_LOOKUPSERVICE
				78	A service name lookup is being requested.
				79	.PP
				80	When the query
				81	is complete or has
				82	failed, the ares library will invoke \fIcallback\fP. Completion or failure of
				83	the query may happen immediately, or may happen during a later call to
				84	\fIares_process(3)\fP, \fIares_destroy(3)\fP or \fIares_cancel(3)\fP.
				85	.PP
				86	The callback argument
				87	.I arg
				88	is copied from the
				89	.B ares_getnameinfo
				90	argument
				91	.IR arg .
				92	The callback argument
				93	.I status
				94	indicates whether the query succeeded and, if not, how it failed. It
				95	may have any of the following values:
				96	.TP 19
				97	.B ARES_SUCCESS
				98	The host lookup completed successfully.
				99	.TP 19
				100	.B ARES_ENOTIMP
				101	The ares library does not know how to look up addresses of type
				102	.IR family .
				103	.TP 19
				104	.B ARES_ENOTFOUND
				105	The address
				106	.I addr
				107	was not found.
				108	.TP 19
				109	.B ARES_ENOMEM
				110	Memory was exhausted.
				111	.TP 19
				112	.B ARES_ECANCELLED
				113	The query was cancelled.
				114	.TP 19
				115	.B ARES_EDESTRUCTION
				116	The name service channel
				117	.I channel
				118	is being destroyed; the query will not be completed.
				119	.TP 19
				120	.B ARES_EBADFLAGS
				121	The
				122	.I flags
				123	parameter contains an illegal value.
				124	.PP
				125	The callback argument
				126	.I timeouts
				127	reports how many times a query timed out during the execution of the
				128	given request.
				129	.PP
				130	On successful completion of the query, the callback argument
				131	.I node
				132	contains a string representing the hostname (assuming
				133	.B ARES_NI_LOOKUPHOST
				134	was specified). Additionally,
				135	.I service
				136	contains a string representing the service name (assuming
				137	.B ARES_NI_LOOKUPSERVICE
				138	was specified).
				139	If the query did not complete successfully, or one of the values
				140	was not requested,
				141	.I node
				142	or
				143	.I service
				144	will be
				145	.BR NULL .
				146	.SH SEE ALSO
				147	.BR ares_process (3),
				148	.SH AUTHOR
				149	Dominick Meglio
				150	.br
				151	Copyright 2005 by Dominick Meglio.