A.2 Port Mapper Operation

The portmapper program currently supports two protocols (UDP/IP and TCP/IP). The portmapper is contacted by talking to it on assigned port number 111 (SUNRPC [8]) on either of these protocols. The following is a description of each of the portmapper procedures:

PMAPPROC_NULL:

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

PMAPPROC_SET:

When a program first becomes available on a machine, it registers itself with the port mapper program on the same machine. The program passes its program number "prog", version number "vers", transport protocol number "prot", and the port "port" on which it awaits service request. The procedure returns a boolean response whose value is "TRUE" if the procedure successfully established the mapping and "FALSE" otherwise. The procedure refuses to establish a mapping if one already exists for the tuple "(prog, vers, prot)".

PMAPPROC_UNSET:

When a program becomes unavailable, it should unregister itself with the port mapper program on the same machine. The parameters and results have meanings identical to those of "PMAPPROC_SET". The protocol and port number fields of the argument are ignored.

PMAPPROC_GETPORT:

Given a program number "prog", version number "vers", and transport protocol number "prot", this procedure returns the port number on which the program is awaiting call requests. A port value of zeros means the program has not been registered. The "port" field of the argument is ignored.

PMAPPROC_DUMP:

This procedure enumerates all entries in the port mapper's database. The procedure takes no parameters and returns a list of program, version, protocol, and port values.

PMAPPROC_CALLIT:

This procedure allows a caller to call another remote procedure on the same machine without knowing the remote procedure's port number. It is intended for supporting broadcasts to arbitrary remote programs via the well-known port mapper's port. The parameters "prog", "vers", "proc", and the bytes of "args" are the program number, version number, procedure number, and parameters of the remote procedure. Note:

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

(2) The port mapper communicates with the remote program using UDP/IP only.

The procedure returns the remote program's port number, and the bytes of results are the results of the remote procedure.

REFERENCES

[1] Birrel, A. D., and Nelson, B. J., "Implementing Remote Procedure Calls", XEROX CSL-83-7, October 1983.

[2] Cheriton, D., "VMTP: Versatile Message Transaction Protocol", Version 0.7, RFC-1045, Stanford University, February 1988.

[3] Diffie & Hellman, "Net Directions in Cryptography", IEEE Transactions on Information Theory IT-22, November 1976.

[4] Postel, J., and Harrenstien, K., "Time Protocol", RFC-868, Network Information Center, SRI, May 1983.

Sun Microsystems, Inc. [Page 23] RFC 1050 Remote Procedure Call April 1988

[5] National Bureau of Standards, "Data Encryption Standard", Federal Information Processing Standards Publication 46, January 1977.

[6] Postel, J., "Transmission Control Protocol - DARPA Internet Program Protocol Specification", RFC-793; Network Information Center, SRI, September 1981.

[7] Postel, J., "User Datagram Protocol", RFC-768, Network Information Center, SRI, August 1980.

[8] Reynolds, J. and Postel, J.; "Assigned Numbers", RFC-1010, Network Information Center, SRI, May 1987.

[9] Sun Microsystems; "XDR: External Data Representation Standard", RFC-1014; Sun Microsystems, June 1987.