RPC Packet header에 대한 짧은 참고의 글..

의미 : 백과사전

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원격 프로시저 호출(Remote procedure call, RPC)은 컴퓨터 프로그램이 다른 주소 공간에서 원격 제어를 위한 프로그래머의 세세한 코딩 없이 함수나 프로시저의 실행을 허용하는 기술이다. 다시 말해, 프로그래머는 함수가 실행 프로그램에 로컬 위치에 있든 원격 위치에 있든 간에 반드시 동일한 코드를 짜게 된다.

어떠한 소프트웨어가 객체 지향의 원칙을 사용하여 프로그래밍 때, RPC는 원격 호출(remote invocation) 또는 원격 메소드 호출(remote method invocation)이라고 일컫는다.

가끔 ONC RPC와 DCE/RPC와 같은 비호환 대상을 수행하기 위해 쓰이는 다른 수많은 기술이 있다.

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The RPC UDP and TCP frames have a structure similar to the following example:

The UDP version is actually an NFS frame that uses Unix for authentication (hence the extra fields) and does not use an authentication verifier.

The RPC Call message has the following fields:

• Transaction ID - matches RPC requests and replies.
• Sending Direction Indicator
• RPC version number - currently the version is 4 for connectionless RPC (using UDP) and 5 for connection-oriented RPC. An extra field is added for connection-oriented RPC for the minor protocol version ('0' or '1').
• Remote Program Number - issued by Sun (rpc@sun.com)
• Remote Program Version Number - version of the program
• Remote Procedure Number - the number of the procedure being called. This number matches the Requests and the Replies and is a 4-byte field containing an 8 digit hexadecimal number.
• Remote Protocol Number - the first 4 least significant bits are used for this. The other bits are reserved.

Sun has control over program numbers 0x00000000 to 0x1fffffff. The range 0x20000000 to 0x3fffffff is for user use when testing new applications. Other ranges above are given out in blocks of 0x20000000.

The following table lists some of the more common Program call numbers that Sun have assigned in their range:

Number	Program	Explanation
0x00100000	portmapper	portmap sunrpc. Manages use of transport ports. Other Lookup services could be used here.
0x00100001	rstat_svc	Remote statistics.
0x00100002	rusersd	Remote users.
0x00100003	nfs	Network file system.
0x00100004	ypserv	ypprog. Yellow pages directory service.
0x00100005	mountd	Mount protocol.
0x00100006	Remote DBX	Remote DBX.
0x00100007	ypbind	Yellow pages binding service.
0x00100008	walld	Shutdown messages.
0x00100009	yppasswd	Yellow pages password server.
0x00100010	etherstatd	Ethernet status.
0x00100011	rquotad	Disk quota manager.
0x00100012	sprayd	Packet generator.
0x00100013	3270_mapper	3270 mapping service.
0x00100014	rje_mapper	Remote job entry mapping service.
0x00100015	selection_svc	Selection service.
0x00100016	database_svc	Remote database access.
0x00100017	rexd	Remote execution.
0x00100018	alis	Alice office automation program.
0x00100019	sched	Scheduling service.
0x00100020	llockmgr	Local lock manager.
0x00100021>	nlockmgr	Network lock manager.
0x00100022	x25.inr	X.25 INR protocol.
0x00100023	statmon	Status monitor 1.
0x00100024	status	Status monitor 2.
0x00100025	Select_Lib	Selection library.
0x00100026	bootparam	Boot parameters service.
0x00100027	Mazewars	Mazewars game.
0x00100028	ypupdated	Yellow pages update service.
0x00100029	Key_Server	Key server.
0x00100030	SecureLogin	Secure login service.
0x00100031	NFS_FwdInit	NFS network forwarding service.
0x00100032	NFS_FwdTrns	NFS forwarding transmitter.
0x00100033	SunLink_MAP	Sunlink MAP.
0x00100034	Net_Monitor	Network monitor.
0x00100035	DataBase	Lightweight database.
0x00100036	Passwd_Auth	Password authorization.
0x00100037	TFS_Service	Translucent file service.
0x00100038	NSE_Service	NSE server.
0x00100039	NSE_Daemon	NSE activate process.
0x00100069	ypxfrd	Yellow Pages Transfer.
0x00150001	pcnfsd	PC password authorization.
0x00200000	PyramidLock	Pyramid lock service.
0x00200001	PyramidSys5	Pyramid Sys5 service.
0x00200002	CADDS_Image	CV CADDS images.
0x00300001	ADTFileLock	ADT file locking service.

There are also the following authentication parameters:

• 0 - (Null) Not used and the authentication fields have zero length.
• 1 - (UNIX) UNIX user and group IDs. If this is the type authentication being used then additional parameters such as the System Name, User ID and Group ID. This is used by NFS.
• 2 - (Short) Shorthand code used, generated by the client
• 3 - (DES) Data encryption standard used by secure NFS.

RFC 2695 describes authentication mechanisms for RPC.
RFC 2203 describes the RPCSEC_GSS ONC RPC security flavor.
RFC 2078 describes Generic Security Service Application Program Interface.

Reply Messages can contain the following messages:

• call successful - Call completed with no errors.
• program unknown - Program number was not found.
• bad program ver - Program version was not found.
• proced unknown - Program procedure was not found.
• bad parameters - Invalid call parameters (arguments) were found.
• bad RPC version - RPC Version not supported.
• bad credentials - Invalid call credentials supplied.
• restart session - Request to begin a new session.
• bad verifier - Invalid verifier was supplied.
• verify rejected - Verifier has expired or was re-used.
• failed security - Caller has insufficient privileges.

 

출처 : http://www.rhyshaden.com/rpc.htm