draft-ietf-nfsv4-rfc1831bis-03.txt   draft-ietf-nfsv4-rfc1831bis-04.txt 
Network Working Group Robert Thurlow Network Working Group Robert Thurlow
Document: draft-ietf-nfsv4-rfc1831bis-03.txt Document: draft-ietf-nfsv4-rfc1831bis-04.txt
RPC: Remote Procedure Call Protocol Specification Version 2 RPC: Remote Procedure Call Protocol Specification Version 2
Status of this Memo Status of this Memo
This document is an Internet-Draft and is subject to all provisions This document is an Internet-Draft and is subject to all provisions
of Section 10 of RFC2026. of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that Task Force (IETF), its areas, and its working groups. Note that
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time. It is inappropriate to use Internet- Drafts as reference time. It is inappropriate to use Internet- Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at The list of current Internet-Drafts can be accessed at
http://www.ietf.org/1id-abstracts.html http://www.ietf.org/1id-abstracts.html
The list of Internet-Draft Shadow Directories can be accessed at The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html http://www.ietf.org/shadow.html
Discussion and suggestions for improvement are requested. This Discussion and suggestions for improvement are requested. This
document will expire in December, 2004. Distribution of this draft is document will expire in March, 2005. Distribution of this draft is
unlimited. unlimited.
Abstract Abstract
This document describes the ONC (Open Network Computing) Remote This document describes the ONC (Open Network Computing) Remote
Procedure Call (ONC RPC Version 2) protocol as it is currently Procedure Call (ONC RPC Version 2) protocol as it is currently
deployed and accepted. It is meant to supersede [RFC1831]. deployed and accepted. It is meant to supersede [RFC1831].
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . 3
3. The RPC Model . . . . . . . . . . . . . . . . . . . . . . . 3 3. The RPC Model . . . . . . . . . . . . . . . . . . . . . . . 3
4. Transports and Semantics . . . . . . . . . . . . . . . . . . 5 4. Transports and Semantics . . . . . . . . . . . . . . . . . . 5
5. Binding and Rendezvous Independence . . . . . . . . . . . . 6 5. Binding and Rendezvous Independence . . . . . . . . . . . . 6
6. Authentication . . . . . . . . . . . . . . . . . . . . . . . 6 6. Authentication . . . . . . . . . . . . . . . . . . . . . . . 6
7. RPC Protocol Requirements . . . . . . . . . . . . . . . . . 6 7. RPC Protocol Requirements . . . . . . . . . . . . . . . . . 6
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11.3. Syntax Notes . . . . . . . . . . . . . . . . . . . . . 16 11.3. Syntax Notes . . . . . . . . . . . . . . . . . . . . . 16
12. IANA Considerations . . . . . . . . . . . . . . . . . . . 17 12. IANA Considerations . . . . . . . . . . . . . . . . . . . 17
13. Security Considerations . . . . . . . . . . . . . . . . . 17 13. Security Considerations . . . . . . . . . . . . . . . . . 17
14. Appendix A: System Authentication . . . . . . . . . . . . 17 14. Appendix A: System Authentication . . . . . . . . . . . . 17
15. Appendix B: Requesting RPC program or authentication 15. Appendix B: Requesting RPC program or authentication
numbers . . . . . . . . . . . . . . . . . . . . . . . . . 18 numbers . . . . . . . . . . . . . . . . . . . . . . . . . 18
16. Normative References . . . . . . . . . . . . . . . . . . 20 16. Normative References . . . . . . . . . . . . . . . . . . 20
17. Informative References . . . . . . . . . . . . . . . . . 20 17. Informative References . . . . . . . . . . . . . . . . . 20
18. Author's Address . . . . . . . . . . . . . . . . . . . . 22 18. Author's Address . . . . . . . . . . . . . . . . . . . . 22
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
1. Introduction 1. Introduction
This document specifies version two of the message protocol used in This document specifies version two of the message protocol used in
ONC Remote Procedure Call (RPC). The message protocol is specified ONC Remote Procedure Call (RPC). The message protocol is specified
with the eXternal Data Representation (XDR) language [RFC1832]. This with the eXternal Data Representation (XDR) language [RFC1832]. This
document assumes that the reader is familiar with XDR. It does not document assumes that the reader is familiar with XDR. It does not
attempt to justify remote procedure calls systems or describe their attempt to justify remote procedure calls systems or describe their
use. The paper by Birrell and Nelson [XRPC] is recommended as an use. The paper by Birrell and Nelson [XRPC] is recommended as an
excellent background for the remote procedure call concept. excellent background for the remote procedure call concept.
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3. The RPC Model 3. The RPC Model
The ONC RPC protocol is based on the remote procedure call model, The ONC RPC protocol is based on the remote procedure call model,
which is similar to the local procedure call model. In the local which is similar to the local procedure call model. In the local
case, the caller places arguments to a procedure in some well- case, the caller places arguments to a procedure in some well-
specified location (such as a register window). It then transfers specified location (such as a register window). It then transfers
control to the procedure, and eventually regains control. At that control to the procedure, and eventually regains control. At that
point, the results of the procedure are extracted from the well- point, the results of the procedure are extracted from the well-
specified location, and the caller continues execution. specified location, and the caller continues execution.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
The remote procedure call model is similar. One thread of control The remote procedure call model is similar. One thread of control
logically winds through two processes: the caller's process, and a logically winds through two processes: the caller's process, and a
server's process. The caller process first sends a call message to server's process. The caller process first sends a call message to
the server process and waits (blocks) for a reply message. The call the server process and waits (blocks) for a reply message. The call
message includes the procedure's parameters, and the reply message message includes the procedure's parameters, and the reply message
includes the procedure's results. Once the reply message is includes the procedure's results. Once the reply message is
received, the results of the procedure are extracted, and caller's received, the results of the procedure are extracted, and caller's
execution is resumed. execution is resumed.
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o Authentication: since remote procedure calls can be transported o Authentication: since remote procedure calls can be transported
over unsecured networks, authentication may be necessary. over unsecured networks, authentication may be necessary.
Authentication prevents one entity from masquerading as some Authentication prevents one entity from masquerading as some
other entity. other entity.
The conclusion is that even though there are tools to automatically The conclusion is that even though there are tools to automatically
generate client and server libraries for a given service, protocols generate client and server libraries for a given service, protocols
must still be designed carefully. must still be designed carefully.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
4. Transports and Semantics 4. Transports and Semantics
The RPC protocol can be implemented on several different transport The RPC protocol can be implemented on several different transport
protocols. The RPC protocol does not care how a message is passed protocols. The RPC protocol does not care how a message is passed
from one process to another, but only with specification and from one process to another, but only with specification and
interpretation of messages. However, the application may wish to interpretation of messages. However, the application may wish to
obtain information about (and perhaps control over) the transport obtain information about (and perhaps control over) the transport
layer through an interface not specified in this document. For layer through an interface not specified in this document. For
example, the transport protocol may impose a restriction on the example, the transport protocol may impose a restriction on the
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may choose to reuse its previous transaction ID when retransmitting a may choose to reuse its previous transaction ID when retransmitting a
call. The server may choose to remember this ID after executing a call. The server may choose to remember this ID after executing a
call and not execute calls with the same ID in order to achieve some call and not execute calls with the same ID in order to achieve some
degree of execute-at-most-once semantics. The server is not allowed degree of execute-at-most-once semantics. The server is not allowed
to examine this ID in any other way except as a test for equality. to examine this ID in any other way except as a test for equality.
On the other hand, if using a "reliable" transport such as TCP, the On the other hand, if using a "reliable" transport such as TCP, the
application can infer from a reply message that the procedure was application can infer from a reply message that the procedure was
executed exactly once, but if it receives no reply message, it cannot executed exactly once, but if it receives no reply message, it cannot
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
assume that the remote procedure was not executed. Note that even if assume that the remote procedure was not executed. Note that even if
a connection-oriented protocol like TCP is used, an application still a connection-oriented protocol like TCP is used, an application still
needs time-outs and reconnection to handle server crashes. needs time-outs and reconnection to handle server crashes.
There are other possibilities for transports besides datagram- or There are other possibilities for transports besides datagram- or
connection-oriented protocols. For example, a request-reply protocol connection-oriented protocols. For example, a request-reply protocol
such as [VMTP] is perhaps a natural transport for RPC. ONC RPC such as [VMTP] is perhaps a natural transport for RPC. ONC RPC
currently uses both TCP and UDP transport protocols. Section 10 currently uses both TCP and UDP transport protocols. Section 10
(Record Marking Standard) describes the mechanism employed by ONC RPC (Record Marking Standard) describes the mechanism employed by ONC RPC
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The RPC protocol must provide for the following: The RPC protocol must provide for the following:
o Unique specification of a procedure to be called. o Unique specification of a procedure to be called.
o Provisions for matching response messages to request messages. o Provisions for matching response messages to request messages.
o Provisions for authenticating the caller to service and vice- o Provisions for authenticating the caller to service and vice-
versa. versa.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
Besides these requirements, features that detect the following are Besides these requirements, features that detect the following are
worth supporting because of protocol roll-over errors, implementation worth supporting because of protocol roll-over errors, implementation
bugs, user error, and network administration: bugs, user error, and network administration:
o RPC protocol mismatches. o RPC protocol mismatches.
o Remote program protocol version mismatches. o Remote program protocol version mismatches.
o Protocol errors (such as misspecification of a procedure's o Protocol errors (such as misspecification of a procedure's
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The reply message to a request message has enough information to The reply message to a request message has enough information to
distinguish the following error conditions: distinguish the following error conditions:
o The remote implementation of RPC does not support protocol o The remote implementation of RPC does not support protocol
version 2. The lowest and highest supported RPC version numbers version 2. The lowest and highest supported RPC version numbers
are returned. are returned.
o The remote program is not available on the remote system. o The remote program is not available on the remote system.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
o The remote program does not support the requested version o The remote program does not support the requested version
number. The lowest and highest supported remote program version number. The lowest and highest supported remote program version
numbers are returned. numbers are returned.
o The requested procedure number does not exist. (This is usually o The requested procedure number does not exist. (This is usually
a client side protocol or programming error.) a client side protocol or programming error.)
o The parameters to the remote procedure appear to be garbage from o The parameters to the remote procedure appear to be garbage from
the server's point of view. (Again, this is usually caused by a the server's point of view. (Again, this is usually caused by a
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(uninterpreted by) the RPC protocol implementation. (uninterpreted by) the RPC protocol implementation.
The interpretation and semantics of the data contained within the The interpretation and semantics of the data contained within the
authentication fields is specified by individual, independent authentication fields is specified by individual, independent
authentication protocol specifications. (Section 9 defines the authentication protocol specifications. (Section 9 defines the
various authentication protocols.) various authentication protocols.)
If authentication parameters were rejected, the reply message If authentication parameters were rejected, the reply message
contains information stating why they were rejected. contains information stating why they were rejected.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
7.3. Program Number Assignment 7.3. Program Number Assignment
Program numbers are given out in groups of hexadecimal 20000000 Program numbers are given out in groups of hexadecimal 20000000
(decimal 536870912) according to the following chart: (decimal 536870912) according to the following chart:
0 Reserved 0 Reserved
1 - 0x1fffffff To be assigned by IANA 1 - 0x1fffffff To be assigned by IANA
0x20000000 - 0x3fffffff Defined by local administrator 0x20000000 - 0x3fffffff Defined by local administrator
(some blocks assigned here) (some blocks assigned here)
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batch calls is usually terminated by a legitimate remote procedure batch calls is usually terminated by a legitimate remote procedure
call operation in order to flush the pipeline and get positive call operation in order to flush the pipeline and get positive
acknowledgement. acknowledgement.
7.4.2. Broadcast Remote Procedure Calls 7.4.2. Broadcast Remote Procedure Calls
In broadcast protocols, the client sends a broadcast call to the In broadcast protocols, the client sends a broadcast call to the
network and waits for numerous replies. This requires the use of network and waits for numerous replies. This requires the use of
packet-based protocols (like UDP) as its transport protocol. Servers packet-based protocols (like UDP) as its transport protocol. Servers
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
that support broadcast protocols usually respond only when the call that support broadcast protocols usually respond only when the call
is successfully processed and are silent in the face of errors, but is successfully processed and are silent in the face of errors, but
this varies with the application. this varies with the application.
The principles of broadcast RPC also apply to multicasting - an RPC The principles of broadcast RPC also apply to multicasting - an RPC
request can be sent to a multicast address. request can be sent to a multicast address.
8. The RPC Message Protocol 8. The RPC Message Protocol
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enum reject_stat { enum reject_stat {
RPC_MISMATCH = 0, /* RPC version number != 2 */ RPC_MISMATCH = 0, /* RPC version number != 2 */
AUTH_ERROR = 1 /* remote can't authenticate caller */ AUTH_ERROR = 1 /* remote can't authenticate caller */
}; };
Why authentication failed: Why authentication failed:
enum auth_stat { enum auth_stat {
AUTH_OK = 0, /* success */ AUTH_OK = 0, /* success */
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
/* /*
* failed at remote end * failed at remote end
*/ */
AUTH_BADCRED = 1, /* bad credential (seal broken) */ AUTH_BADCRED = 1, /* bad credential (seal broken) */
AUTH_REJECTEDCRED = 2, /* client must begin new session */ AUTH_REJECTEDCRED = 2, /* client must begin new session */
AUTH_BADVERF = 3, /* bad verifier (seal broken) */ AUTH_BADVERF = 3, /* bad verifier (seal broken) */
AUTH_REJECTEDVERF = 4, /* verifier expired or replayed */ AUTH_REJECTEDVERF = 4, /* verifier expired or replayed */
AUTH_TOOWEAK = 5, /* rejected for security reasons */ AUTH_TOOWEAK = 5, /* rejected for security reasons */
/* /*
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struct rpc_msg { struct rpc_msg {
unsigned int xid; unsigned int xid;
union switch (msg_type mtype) { union switch (msg_type mtype) {
case CALL: case CALL:
call_body cbody; call_body cbody;
case REPLY: case REPLY:
reply_body rbody; reply_body rbody;
} body; } body;
}; };
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
Body of an RPC call: Body of an RPC call:
In version 2 of the RPC protocol specification, rpcvers must be equal In version 2 of the RPC protocol specification, rpcvers must be equal
to 2. The fields prog, vers, and proc specify the remote program, to 2. The fields prog, vers, and proc specify the remote program,
its version number, and the procedure within the remote program to be its version number, and the procedure within the remote program to be
called. After these fields are two authentication parameters: cred called. After these fields are two authentication parameters: cred
(authentication credential) and verf (authentication verifier). The (authentication credential) and verf (authentication verifier). The
two authentication parameters are followed by the parameters to the two authentication parameters are followed by the parameters to the
remote procedure, which are specified by the specific program remote procedure, which are specified by the specific program
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order to validate itself to the client. It is followed by a union order to validate itself to the client. It is followed by a union
whose discriminant is an enum accept_stat. The SUCCESS arm of the whose discriminant is an enum accept_stat. The SUCCESS arm of the
union is protocol specific. The PROG_UNAVAIL, PROC_UNAVAIL, union is protocol specific. The PROG_UNAVAIL, PROC_UNAVAIL,
GARBAGE_ARGS, and SYSTEM_ERR arms of the union are void. The GARBAGE_ARGS, and SYSTEM_ERR arms of the union are void. The
PROG_MISMATCH arm specifies the lowest and highest version numbers of PROG_MISMATCH arm specifies the lowest and highest version numbers of
the remote program supported by the server. the remote program supported by the server.
struct accepted_reply { struct accepted_reply {
opaque_auth verf; opaque_auth verf;
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
union switch (accept_stat stat) { union switch (accept_stat stat) {
case SUCCESS: case SUCCESS:
opaque results[0]; opaque results[0];
/* /*
* procedure-specific results start here * procedure-specific results start here
*/ */
case PROG_MISMATCH: case PROG_MISMATCH:
struct { struct {
unsigned int low; unsigned int low;
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9. Authentication Protocols 9. Authentication Protocols
As previously stated, authentication parameters are opaque, but As previously stated, authentication parameters are opaque, but
open-ended to the rest of the RPC protocol. This section defines two open-ended to the rest of the RPC protocol. This section defines two
standard "flavors" of authentication. Implementors are free to standard "flavors" of authentication. Implementors are free to
invent new authentication types, with the same rules of flavor number invent new authentication types, with the same rules of flavor number
assignment as there is for program number assignment. The "flavor" assignment as there is for program number assignment. The "flavor"
of a credential or verifier refers to the value of the "flavor" field of a credential or verifier refers to the value of the "flavor" field
in the opaque_auth structure. Flavor numbers, like RPC program in the opaque_auth structure. Flavor numbers, like RPC program
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
numbers, are also administered centrally, and developers may assign numbers, are also administered centrally, and developers may assign
new flavor numbers by methods described in Appendix B. Credentials new flavor numbers by methods described in Appendix B. Credentials
and verifiers are represented as variable length opaque data (the and verifiers are represented as variable length opaque data (the
"body" field in the opaque_auth structure). "body" field in the opaque_auth structure).
In this document, two flavors of authentication are described. Of In this document, two flavors of authentication are described. Of
these, Null authentication (described in the next subsection) is these, Null authentication (described in the next subsection) is
mandatory - it must be available in all implementations. System mandatory - it must be available in all implementations. System
authentication (AUTH_SYS) is described in Appendix A. It is strongly authentication (AUTH_SYS) is described in Appendix A. It is strongly
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highest-order bit of the header; the length is the 31 low-order bits. highest-order bit of the header; the length is the 31 low-order bits.
(Note that this record specification is NOT in XDR standard form!) (Note that this record specification is NOT in XDR standard form!)
11. The RPC Language 11. The RPC Language
Just as there was a need to describe the XDR data-types in a formal Just as there was a need to describe the XDR data-types in a formal
language, there is also need to describe the procedures that operate language, there is also need to describe the procedures that operate
on these XDR data-types in a formal language as well. The RPC on these XDR data-types in a formal language as well. The RPC
Language is an extension to the XDR language, with the addition of Language is an extension to the XDR language, with the addition of
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
"program", "procedure", and "version" declarations. The following "program", "procedure", and "version" declarations. The following
example is used to describe the essence of the language. example is used to describe the essence of the language.
11.1. An Example Service Described in the RPC Language 11.1. An Example Service Described in the RPC Language
Here is an example of the specification of a simple ping program. Here is an example of the specification of a simple ping program.
program PING_PROG { program PING_PROG {
/* /*
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convention, procedure 0 of any RPC protocol should have the same convention, procedure 0 of any RPC protocol should have the same
semantics, and never require any kind of authentication. The second semantics, and never require any kind of authentication. The second
procedure is used for the client to have the server do a reverse ping procedure is used for the client to have the server do a reverse ping
operation back to the client, and it returns the amount of time (in operation back to the client, and it returns the amount of time (in
microseconds) that the operation used. The next version, microseconds) that the operation used. The next version,
PING_VERS_ORIG, is the original version of the protocol and it does PING_VERS_ORIG, is the original version of the protocol and it does
not contain PINGPROC_PINGBACK procedure. It is useful for not contain PINGPROC_PINGBACK procedure. It is useful for
compatibility with old client programs, and as this program matures compatibility with old client programs, and as this program matures
it may be dropped from the protocol entirely. it may be dropped from the protocol entirely.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
11.2. The RPC Language Specification 11.2. The RPC Language Specification
The RPC language is identical to the XDR language defined in RFC The RPC language is identical to the XDR language defined in RFC
1014, except for the added definition of a "program-def" described 1014, except for the added definition of a "program-def" described
below. below.
program-def: program-def:
"program" identifier "{" "program" identifier "{"
version-def version-def
version-def * version-def *
"}" "=" constant ";" "}" "=" constant ";"
version-def: version-def:
"version" identifier "{" "version" identifier "{"
procedure-def procedure-def
procedure-def * procedure-def *
"}" "=" constant ";" "}" "=" constant ";"
procedure-def: procedure-def:
proc-return identifier "(" type-specifier proc-return identifier "(" proc-firstarg
("," type-specifier )* ")" "=" constant ";" ("," type-specifier )* ")" "=" constant ";"
proc-return: "void" | type-specifier proc-return: "void" | type-specifier
proc-firstarg: "void" | type-specifier
11.3. Syntax Notes 11.3. Syntax Notes
o The following keywords are added and cannot be used as o The following keywords are added and cannot be used as
identifiers: "program" and "version"; identifiers: "program" and "version";
o A version name cannot occur more than once within the scope of a o A version name cannot occur more than once within the scope of a
program definition. Nor can a version number occur more than program definition. Nor can a version number occur more than
once within the scope of a program definition. once within the scope of a program definition.
o A procedure name cannot occur more than once within the scope of o A procedure name cannot occur more than once within the scope of
a version definition. Nor can a procedure number occur more than a version definition. Nor can a procedure number occur more than
once within the scope of version definition. once within the scope of version definition.
o Program identifiers are in the same name space as constant and o Program identifiers are in the same name space as constant and
type identifiers. type identifiers.
o Only unsigned constants can be assigned to programs, versions o Only unsigned constants can be assigned to programs, versions
and procedures. and procedures.
o Current RPC language compilers do not generally support more o Current RPC language compilers do not generally support more
Title Remote Procedure Call Protocol Version 2 September 2004
than one type-specifier in procedure argument lists; the usual than one type-specifier in procedure argument lists; the usual
practice is to wrap arguments into a structure. practice is to wrap arguments into a structure.
Title Remote Procedure Call Protocol Version 2 June 2004
12. IANA Considerations 12. IANA Considerations
[RPCIANA] proposes to transfer authority over RPC program numbers and [RPCIANA] proposes to transfer authority over RPC program numbers and
authentication flavor numbers described here from Sun Microsystems, authentication flavor numbers described here from Sun Microsystems,
Inc. to IANA. This document assumes this transfer. Inc. to IANA. This document assumes this transfer.
13. Security Considerations 13. Security Considerations
AUTH_SYS as described in Appendix A is known to be insecure due to AUTH_SYS as described in Appendix A is known to be insecure due to
the lack of a verifier to permit the credential to be validated. Use the lack of a verifier to permit the credential to be validated. Use
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The "stamp" is an arbitrary ID which the caller machine may generate. The "stamp" is an arbitrary ID which the caller machine may generate.
The "machinename" is the name of the caller's machine (like The "machinename" is the name of the caller's machine (like
"krypton"). The "uid" is the caller's effective user ID. The "gid" "krypton"). The "uid" is the caller's effective user ID. The "gid"
is the caller's effective group ID. The "gids" is a counted array of is the caller's effective group ID. The "gids" is a counted array of
groups which contain the caller as a member. The verifier groups which contain the caller as a member. The verifier
accompanying the credential should have "AUTH_NONE" flavor value accompanying the credential should have "AUTH_NONE" flavor value
(defined above). Note this credential is only unique within a (defined above). Note this credential is only unique within a
particular domain of machine names, uids, and gids. particular domain of machine names, uids, and gids.
Title Remote Procedure Call Protocol Version 2 September 2004
The flavor value of the verifier received in the reply message from The flavor value of the verifier received in the reply message from
the server may be "AUTH_NONE" or "AUTH_SHORT". In the case of the server may be "AUTH_NONE" or "AUTH_SHORT". In the case of
"AUTH_SHORT", the bytes of the reply verifier's string encode an "AUTH_SHORT", the bytes of the reply verifier's string encode an
opaque structure. This new opaque structure may now be passed to the opaque structure. This new opaque structure may now be passed to the
Title Remote Procedure Call Protocol Version 2 June 2004
server instead of the original "AUTH_SYS" flavor credential. The server instead of the original "AUTH_SYS" flavor credential. The
server may keep a cache which maps shorthand opaque structures server may keep a cache which maps shorthand opaque structures
(passed back by way of an "AUTH_SHORT" style reply verifier) to the (passed back by way of an "AUTH_SHORT" style reply verifier) to the
original credentials of the caller. The caller can save network original credentials of the caller. The caller can save network
bandwidth and server cpu cycles by using the shorthand credential. bandwidth and server cpu cycles by using the shorthand credential.
The server may flush the shorthand opaque structure at any time. If The server may flush the shorthand opaque structure at any time. If
this happens, the remote procedure call message will be rejected due this happens, the remote procedure call message will be rejected due
to an authentication error. The reason for the failure will be to an authentication error. The reason for the failure will be
"AUTH_REJECTEDCRED". At this point, the client may wish to try the "AUTH_REJECTEDCRED". At this point, the client may wish to try the
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o The name of person or company which will use the number o The name of person or company which will use the number
o An "identifier string" which associates the number with a o An "identifier string" which associates the number with a
service service
o Email address of the contact person for the service which will o Email address of the contact person for the service which will
be using the number. be using the number.
o A short description of the purpose and use of the number o A short description of the purpose and use of the number
Title Remote Procedure Call Protocol Version 2 September 2004
o If an authentication flavor number is sought, and the number o If an authentication flavor number is sought, and the number
will be a 'pseudo-flavor' intended for use with RPCSEC_GSS and will be a 'pseudo-flavor' intended for use with RPCSEC_GSS and
NFS, mappings analogous to those in Section 4.2 of [RFC2623] are NFS, mappings analogous to those in Section 4.2 of [RFC2623] are
Title Remote Procedure Call Protocol Version 2 June 2004
required. required.
Specific numbers cannot be requested. Numbers are assigned on a Specific numbers cannot be requested. Numbers are assigned on a
First Come First Served basis. First Come First Served basis.
For all RPC authentication flavor numbers to used on the Internet, it For all RPC authentication flavor numbers to used on the Internet, it
is strongly advised that an informational or standards-track RFC be is strongly advised that an informational or standards-track RFC be
published describing the authentication mechanism behaviour and published describing the authentication mechanism behaviour and
parameters. parameters.
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
16. Normative References 16. Normative References
[RFC1832] [RFC1832]
Srinivasan, R., "XDR: External Data Representation Standard", RFC Srinivasan, R., "XDR: External Data Representation Standard", RFC
1832, Sun Microsystems, Inc., August 1995. 1832, Sun Microsystems, Inc., August 1995.
17. Informative References 17. Informative References
[XRPC] [XRPC]
skipping to change at page 21, line 5 skipping to change at page 21, line 5
Protocol Specification", STD 7, RFC 793, USC/Information Sciences Protocol Specification", STD 7, RFC 793, USC/Information Sciences
Institute, September 1981. Institute, September 1981.
[RFC768] [RFC768]
Postel, J., "User Datagram Protocol", STD 6, RFC 768, USC/Information Postel, J., "User Datagram Protocol", STD 6, RFC 768, USC/Information
Sciences Institute, August 1980. Sciences Institute, August 1980.
[RFC1700] [RFC1700]
Reynolds, J., and Postel, J., "Assigned Numbers", STD 2, RFC 1700, Reynolds, J., and Postel, J., "Assigned Numbers", STD 2, RFC 1700,
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
USC/Information Sciences Institute, October 1994. USC/Information Sciences Institute, October 1994.
[RFC1831] [RFC1831]
R. Srinivasan, "RPC: Remote Procedure Call Protocol Specification R. Srinivasan, "RPC: Remote Procedure Call Protocol Specification
Version 2", RFC1831, August 1995. Version 2", RFC1831, August 1995.
[KERB87] [KERB87]
Miller, S., Neuman, C., Schiller, J., and J. Saltzer, "Section Miller, S., Neuman, C., Schiller, J., and J. Saltzer, "Section
E.2.1: Kerberos Authentication and Authorization System", M.I.T. E.2.1: Kerberos Authentication and Authorization System", M.I.T.
skipping to change at page 22, line 5 skipping to change at page 22, line 5
[RFC1510] [RFC1510]
Kohl, J. and C. Neuman, "The Kerberos Network Authentication Service Kohl, J. and C. Neuman, "The Kerberos Network Authentication Service
(V5)", RFC 1510, Digital Equipment Corporation, USC/Information (V5)", RFC 1510, Digital Equipment Corporation, USC/Information
Sciences Institute, September 1993. Sciences Institute, September 1993.
[RPCIANA] [RPCIANA]
R. Thurlow, "RPC Numbering Authority Transfer to IANA", R. Thurlow, "RPC Numbering Authority Transfer to IANA",
http://www.ietf.org/internet-drafts/draft-ietf-nfsv4-rpc-iana-01.txt, http://www.ietf.org/internet-drafts/draft-ietf-nfsv4-rpc-iana-01.txt,
May 2004 May 2004
Title Remote Procedure Call Protocol Version 2 June 2004 Title Remote Procedure Call Protocol Version 2 September 2004
18. Author's Address 18. Author's Address
Address comments related to this memorandum to: Address comments related to this memorandum to:
nfsv4-wg@sunroof.eng.sun.com nfsv4-wg@sunroof.eng.sun.com
Robert Thurlow Robert Thurlow
Sun Microsystems, Inc. Sun Microsystems, Inc.
500 Eldorado Boulevard, UBRM05-171 500 Eldorado Boulevard, UBRM05-171
 End of changes. 

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