ONC+ Developer's Guide

rpcbind Operation

rpcbind is contacted by way of an assigned address specific to the transport being used. For TCP/IP and UDP/IP, for example, it is port number 111. Each transport has such an assigned well-known address. This section describes a description of each of the procedures supported by rpcbind.


This procedure does no work. By convention, procedure zero of any program takes no parameters and returns no results.


When a program first becomes available on a machine, it registers itself with the rpcbind program running on the same machine. The program passes its program number prog, version number vers, network identifier netid, and the universal address uaddr; on which it awaits service requests.

The procedure returns a Boolean response with the value TRUE if the procedure successfully established the mapping and FALSE otherwise. The procedure refuses to establish a mapping if one already exists for the ordered set (prog, vers, netid).

Neither netid nor uaddr can be NULL, and that netid should be a valid network identifier on the machine making the call.


When a program becomes unavailable, it should unregister itself with the rpcbind program on the same machine.

The parameters and results have meanings identical to those of RPCBPROC_SET. The mapping of the (prog, vers, netid) tuple with uaddr is deleted.

If netid is NULL, all mappings specified by the ordered set (prog, vers, *) and the corresponding universal addresses are deleted. Only the owner of the service or the superuser is allowed to unset a service.


Given a program number prog, version number vers, and network identifier netid, this procedure returns the universal address on which the program is awaiting call requests.

The netid field of the argument is ignored and the netid is inferred from the netid of the transport on which the request came in.


This procedure lists all entries in rpcbind's database.

The procedure takes no parameters and returns a list of program, version, netid, and universal addresses. Call this procedure using a stream rather than a datagram transport to avoid the return of a large amount of data.


This procedure enables a caller to call another remote procedure on the same machine without knowing the remote procedure's universal address. RPCBPROC_CALLIT support broadcasts to arbitrary remote programs through rpcbind's universal address.

The parameters prog, vers, proc, and the args_ptr are the program number, version number, procedure number, and parameters of the remote procedure.

This procedure sends a response only if the procedure was successfully executed, and is silent (no response) otherwise.

The procedure returns the remote program's universal address, and the results of the remote procedure.


This procedure returns the local time on its own machine in seconds since midnight of January 1, 1970.


This procedure converts universal addresses to transport (netbuf) addresses. RPCBPROC_UADDR2TADDR is equivalent to uaddr2taddr(). See the netdir(3NSL) man page. Only processes that cannot link to the name-to-address library modules should use RPCBPROC_UADDR2TADDR.


This procedure converts transport (netbuf) addresses to universal addresses. RPCBPROC_TADDR2UADDR is equivalent to taddr2uaddr(). See the netdir(3NSL) man page. Only processes that cannot link to the name-to-address library modules should use RPCBPROC_TADDR2UADDR.

Version 4 rpcbind

Version 4 of the rpcbind protocol includes all of the previous procedures, and adds several others.


This procedure is identical to the version 3 RPCBPROC_CALLIT procedure. The new name indicates that the procedure should be used for broadcast RPCs only. RPCBPROC_INDIRECT, defined in the following text, should be used for indirect RPC calls.


This procedure is similar to RPCBPROC_GETADDR. The difference is that the r_vers field of the rpcb structure can be used to specify the version of interest. If that version is not registered, no address is returned.


This procedure is similar to RPCBPROC_CALLIT. Instead of being silent about errors, such as the program not being registered on the system, this procedure returns an indication of the error. Do not use this procedure for broadcast RPC. Use it with indirect RPC calls only.


This procedure returns a list of addresses for the given rpcb entry. The client might be able to use the results to determine alternate transports that it can use to communicate with the server.


This procedure returns statistics on the activity of the rpcbind server. The information lists the number and kind of requests the server has received.

All procedures except RPCBPROC_SET and RPCBPROC_UNSET can be called by clients running on a machine other than a machine on which rpcbind is running. rpcbind accepts only RPCPROC_SET and RPCPROC_UNSET requests on the loopback transport.