lwres_getnameinfo(3)

NAME

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

SYNOPSIS

       #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);

DESCRIPTION

       This function is equivalent to the getnameinfo(3) function defined in
       RFC2133.  lwres_getnameinfo() returns the hostname for the struct
       sockaddrsa 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:

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

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

       NI_NAMEREQD
           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.

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

       NI_DGRAM
           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.

RETURN VALUES

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

SEE ALSO

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

BUGS

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

AUTHOR

       Internet Systems Consortium, Inc.

COPYRIGHT

       Copyright (C) 2004, 2005, 2007, 2014-2016 Internet Systems Consortium,
       Inc. ("ISC")
       Copyright (C) 2000, 2001 Internet Software Consortium.

ISC                               2007-06-18              LWRES_GETNAMEINFO(3)