ARES_GETNAMEINFO(3)    FreeBSD 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
       _gethostbyaddr&section=3">ares_gethostbyaddr(3) and getservbyport(3). The function will translate
       the address either by executing a host query on the name service
       channel identified by channel or it will attempt to resolve it locally
       if possible.  The parameters sa and len give the address as a sockaddr
       structure, 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 immediately,
       or may happen during a later call to _process&section=3">ares_process(3), _destroy&section=3">ares_destroy(3)
       or _cancel&section=3">ares_cancel(3).

       The callback argument arg is copied from the ares_getnameinfo 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 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),

AUTHOR
       Dominick Meglio
       Copyright 2005 by Dominick Meglio.

                                  1 May 2009               ARES_GETNAMEINFO(3)