ares_getnameinfo(3)

ARES_GETNAMEINFO(3)    C LIBRARY FUNCTIONS    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
          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 combina-
     tion  of  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  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 can-
                        not 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

                     Last change: 1 May 2009                    1

ARES_GETNAMEINFO(3)    C LIBRARY FUNCTIONS    ARES_GETNAMEINFO(3)

                        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
     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 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 com-
                        pleted.

     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

                     Last change: 1 May 2009                    2

ARES_GETNAMEINFO(3)    C LIBRARY FUNCTIONS    ARES_GETNAMEINFO(3)

     Copyright 2005 by Dominick Meglio.

                     Last change: 1 May 2009                    3