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       lwres_getnameinfo - lightweight resolver socket address structure to
       hostname and service name


       #include <lwres/netdb.h>

       int lwres_getnameinfo(const struct sockaddr *sa, size_t salen,
                             char *host, size_t hostlen, char *serv,
                             size_t servlen, int flags);


       This function is equivalent to the getnameinfo(3) function defined in
       RFC2133.  lwres_getnameinfo() returns the hostname for the struct
       sockaddr sa which is salen bytes long. The hostname is of length
       hostlen and is returned via *host.  The maximum length of the hostname
       is 1025 bytes: NI_MAXHOST.

       The name of the service associated with the port number in sa is
       returned in *serv.  It is servlen bytes long. The maximum length of the
       service name is NI_MAXSERV - 32 bytes.

       The flags argument sets the following bits:

           A fully qualified domain name is not required for local hosts. The
           local part of the fully qualified domain name is returned instead.

           Return the address in numeric form, as if calling inet_ntop(),
           instead of a host name.

           A name is required. If the hostname cannot be found in the DNS and
           this flag is set, a non-zero error code is returned. If the
           hostname is not found and the flag is not set, the address is
           returned in numeric form.

           The service name is returned as a digit string representing the
           port number.

           Specifies that the service being looked up is a datagram service,
           and causes getservbyport() to be called with a second argument of
           "udp" instead of its default of "tcp". This is required for the few
           ports (512-514) that have different services for UDP and TCP.


       lwres_getnameinfo() returns 0 on success or a non-zero error code if an
       error occurs.


       RFC2133(), getservbyport(3), lwres(3), lwres_getnameinfo(3),
       lwres_getnamebyaddr(3).  lwres_net_ntop(3).


       RFC2133 fails to define what the nonzero return values of
       getnameinfo(3) are.


       Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc.
       Copyright (C) 2000, 2001 Internet Software Consortium.