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ares_getnameinfo(3) [centos man page]

ARES_GETNAMEINFO(3)					     Library Functions Manual					       ARES_GETNAMEINFO(3)

NAME

       ares_getnameinfo - Address-to-nodename translation in protocol-independent manner

SYNOPSIS

       #include <ares.h>

       typedef void (*ares_nameinfo_callback)(void *arg, int status,
       int timeouts, char *node, char *service)

       void ares_getnameinfo(ares_channel channel, const struct sockaddr *sa,
	    ares_socklen_t salen, int flags, ares_nameinfo_callback callback,
	    void *arg)

DESCRIPTION

       The  ares_getnameinfo  function	is  defined  for  protocol-independent address translation. The function is a combination of ares_gethost-
       byaddr(3) and getservbyport(3). The function will translate the address either by executing a host query on the name service channel  iden-
       tified  by  channel  or it will attempt to resolve it locally if possible.  The parameters sa and len give the address as a sockaddr struc-
       ture, and flags gives the options that the function will use.  Valid flags are listed below:

       ARES_NI_NOFQDN	  Only the nodename portion of the FQDN is returned for local hosts.

       ARES_NI_NUMERICHOST
			  The numeric form of the hostname is returned rather than the name.

       ARES_NI_NAMEREQD   An error is returned if the hostname cannot be found in the DNS.

       ARES_NI_NUMERICSERV
			  The numeric form of the service is returned rather than the name.

       ARES_NI_TCP	  The service name is to be looked up for the TCP protocol.

       ARES_NI_UDP	  The service name is to be looked up for the UDP protocol.

       ARES_NI_SCTP	  The service name is to be looked up for the SCTP protocol.

       ARES_NI_DCCP	  The service name is to be looked up for the DCCP protocol.

       ARES_NI_NUMERICSCOPE
			  The numeric form of the scope ID is returned rather than the name.

       ARES_NI_LOOKUPHOST A hostname lookup is being requested.

       ARES_NI_LOOKUPSERVICE
			  A service name lookup is being requested.

       When the query is complete or has failed, the ares library will invoke callback.  Completion or failure of the  query  may  happen  immedi-
       ately, or may happen during a later call to ares_process(3), ares_destroy(3) or ares_cancel(3).

       The  callback argument arg is copied from the ares_getnameinfo argument arg.  The callback argument status indicates whether the query suc-
       ceeded and, if not, how it failed.  It may have any of the following values:

       ARES_SUCCESS	  The host lookup completed successfully.

       ARES_ENOTIMP	  The ares library does not know how to look up addresses of type family.

       ARES_ENOTFOUND	  The address addr was not found.

       ARES_ENOMEM	  Memory was exhausted.

       ARES_ECANCELLED	  The query was cancelled.

       ARES_EDESTRUCTION  The name service channel channel is being destroyed; the query will not be completed.

       ARES_EBADFLAGS	  The flags parameter contains an illegal value.

       The callback argument timeouts reports how many times a query timed out during the execution of the given request.

       On successful completion of the query, the callback argument node contains a string representing the hostname (assuming	ARES_NI_LOOKUPHOST
       was  specified).  Additionally, service contains a string representing the service name (assuming ARES_NI_LOOKUPSERVICE was specified).	If
       the query did not complete successfully, or one of the values was not requested, node or service will be NULL.

SEE ALSO

       ares_process(3), ares_getaddrinfo(3)

AUTHOR

       Dominick Meglio
       Copyright 2005 by Dominick Meglio.

								    1 May 2009						       ARES_GETNAMEINFO(3)

Check Out this Related Man Page

ARES_SEND(3)						     Library Functions Manual						      ARES_SEND(3)

NAME

       ares_send - Initiate a DNS query

SYNOPSIS

       #include <ares.h>

       typedef void (*ares_callback)(void *arg, int status,
       int timeouts, unsigned char *abuf, int alen)

       void ares_send(ares_channel channel, const unsigned char *qbuf,
	    int qlen, ares_callback callback, void *arg)

DESCRIPTION

       The  ares_send function initiates a DNS query on the name service channel identified by channel.  The parameters qbuf and qlen give the DNS
       query, which should already have been formatted according to the DNS protocol.  When the query is complete or has failed, the ares  library
       will  invoke  callback.	Completion or failure of the query may happen immediately, or may happen during a later call to ares_process(3) or
       ares_destroy(3).

       The callback argument arg is copied from the ares_send argument arg.  The callback argument status indicates whether  the  query  succeeded
       and, if not, how it failed.  It may have any of the following values:

       ARES_SUCCESS	  The query completed.

       ARES_EBADQUERY	  The query buffer was poorly formed (was not long enough for a DNS header or was too long for TCP transmission).

       ARES_ETIMEOUT	  No name servers responded within the timeout period.

       ARES_ECONNREFUSED  No name servers could be contacted.

       ARES_ENOMEM	  Memory was exhausted.

       ARES_EDESTRUCTION  The name service channel channel is being destroyed; the query will not be completed.

       The callback argument timeouts reports how many times a query timed out during the execution of the given request.

       If  the	query completed, the callback argument abuf points to a result buffer of length alen.  If the query did not complete, abuf will be
       NULL and alen will be 0.

       Unless the flag ARES_FLAG_NOCHECKRESP was set at channel initialization time, ares_send will normally ignore responses whose  questions	do
       not  match  the questions in qbuf, as well as responses with reply codes of SERVFAIL, NOTIMP, and REFUSED.  Unlike other query functions in
       the ares library, however, ares_send does not inspect the header of the reply packet to determine the error status, so a callback status of
       ARES_SUCCESS does not reflect as much about the response as for other query functions.

SEE ALSO

       ares_process(3)

AUTHOR

       Greg Hudson, MIT Information Systems
       Copyright 1998 by the Massachusetts Institute of Technology.

								   25 July 1998 						      ARES_SEND(3)
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