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 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:

       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.

COPYRIGHT

       Copyright © 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC")
       Copyright © 2000, 2001 Internet Software Consortium.