Network File System Version 4                              B. Coddington
Internet-Draft                                                 S. Mayhew
Intended status: Standards Track                                 Red Hat
Expires: 6 January 2023                                    C. Lever, Ed.
                                                                  Oracle
                                                             5 July 2022


               Remote Procedure Call over QUIC Version 1
                   draft-cel-nfsv4-rpc-over-quicv1-01

Abstract

   This document specifies a protocol for conveying Remote Procedure
   (RPC) messages on QUIC version 1 connections.  It requires no
   revision to application RPC protocols or the RPC protocol itself.

Note

   This note is to be removed before publishing as an RFC.

   Discussion of this draft occurs on the NFSv4 working group mailing
   list (nfsv4@ietf.org), archived at
   https://mailarchive.ietf.org/arch/browse/nfsv4/. Working Group
   information is available at https://datatracker.ietf.org/wg/nfsv4/
   about/.

   Submit suggestions and changes as pull requests at
   https://github.com/chucklever/i-d-rpc-over-quicv1.  Instructions are
   on that page.

Status of This Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
   Task Force (IETF).  Note that other groups may also distribute
   working documents as Internet-Drafts.  The list of current Internet-
   Drafts is at https://datatracker.ietf.org/drafts/current/.

   Internet-Drafts are draft documents valid for a maximum of six months
   and may be updated, replaced, or obsoleted by other documents at any
   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on 6 January 2023.




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Copyright Notice

   Copyright (c) 2022 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents (https://trustee.ietf.org/
   license-info) in effect on the date of publication of this document.
   Please review these documents carefully, as they describe your rights
   and restrictions with respect to this document.  Code Components
   extracted from this document must include Revised BSD License text as
   described in Section 4.e of the Trust Legal Provisions and are
   provided without warranty as described in the Revised BSD License.

Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . .   2
   2.  Requirements Language . . . . . . . . . . . . . . . . . . . .   3
   3.  RPC-over-QUIC Framework . . . . . . . . . . . . . . . . . . .   3
     3.1.  Transport Layer Security  . . . . . . . . . . . . . . . .   3
     3.2.  RPC Message Framing . . . . . . . . . . . . . . . . . . .   4
     3.3.  Connections and Streams . . . . . . . . . . . . . . . . .   4
   4.  Implementation Status . . . . . . . . . . . . . . . . . . . .   5
   5.  Security Considerations . . . . . . . . . . . . . . . . . . .   6
   6.  IANA Considerations . . . . . . . . . . . . . . . . . . . . .   6
     6.1.  Netids for RPC-over-QUIC  . . . . . . . . . . . . . . . .   6
   7.  References  . . . . . . . . . . . . . . . . . . . . . . . . .   6
     7.1.  Normative References  . . . . . . . . . . . . . . . . . .   6
     7.2.  Informative References  . . . . . . . . . . . . . . . . .   7
   Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . .   8
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . .   8

1.  Introduction

   QUIC is a reliable, connection-oriented network transport protocol
   that is designed to be general-purpose and secure [RFC9000].  Its
   features include integrated transport layer security, multiple
   streams over each connection, fast reconnect, and robust recovery
   from packet loss and network congestion.

   Open Network Computing Remote Procedure Call (often shortened to
   "RPC") is a Remote Procedure Call protocol that runs over a variety
   of network transports [RFC5531].  RPC implementations so far use UDP
   [RFC0768] or TCP [RFC0793].  This document specifies how to transport
   RPC messages over QUIC version 1.

      |  Explain motivations:
      |



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      |     *  TLS
      |
      |     *  Multiple streams--though applications are speculative at
      |        this point.  (Maybe they will allow more sophisticated
      |        prioritization of traffic without the overhead of
      |        multiple TCP connections?)
      |
      |     *  Lower-latency connection setup--though NFS connections
      |        are typically long-lived.
      |
      |     *  Likely SMB adoption of QUIC should make QUIC
      |        implementations widely available.
      |
      |  In addition, this section needs to document and demonstrate
      |  specific use cases that cannot be addressed using existing RPC
      |  transports and security mechanisms such as RPC-over-TCP, RPC-
      |  with-TLS, or RPC-over-RDMA.

2.  Requirements Language

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
   "OPTIONAL" in this document are to be interpreted as described in
   BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
   capitals, as shown here.

3.  RPC-over-QUIC Framework

   RPC is first and foremost a message-passing protocol.  This section
   covers the implementaion details of exchanging RPC messages over
   QUICv1.  Readers should already be familiar with ONC RPC [RFC5531].

3.1.  Transport Layer Security

   RPC-over-QUIC provides peer authentication and encryption services
   using a framework based on Transport Layer Security (TLS).  Ergo,
   RPC-over-QUIC inherently fulfills many of the requirements of
   [I-D.ietf-nfsv4-rpc-tls].  The details of QUIC's use of TLS are
   specified in [RFC9001].  In particular:

   *  With QUICv1, security at the transport layer is always enabled.
      Thus, there is no need or use for the STARTTLS mechanism described
      in Section 4 of [I-D.ietf-nfsv4-rpc-tls].

   *  The discussion in [I-D.ietf-nfsv4-rpc-tls] about the opportunistic
      use of TLS does not apply to RPC-over-QUIC.





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   *  The peer authentication requirements in Section 5.2 of
      [I-D.ietf-nfsv4-rpc-tls] do apply to RPC-over-QUIC.

   *  The PKIX Extended Key Usage values defined in
      [I-D.ietf-nfsv4-rpc-tls] are also valid for use with RPC-over-
      QUIC.

   *  The ALPN defined in Section 8.2 of [I-D.ietf-nfsv4-rpc-tls] is
      also used for RPC-over-QUIC.

3.2.  RPC Message Framing

   Record marking on QUIC is exactly as in TCP.  See Section 11 of
   [RFC5531].

      |  Discussion: This is the simplest thing to do.
      |
      |  bfields: Open question whether we should do something more
      |  complicated that adds RDMA-like features or at least provides
      |  some minimal help with data alignment.  Possibilities might
      |  include a single additional integer giving the offset of a
      |  payload, serving only as a hint; or reference additional
      |  streams in the same connection for payloads; or even looking
      |  into full RDMA--long-term there may be interest in supporting
      |  RDMA over QUIC, and we may be able to piggyback on that effort.
      |
      |  cel: Direct data placement over TCP can already be accomplished
      |  today using MPA/DDP protocols (formerly known as iWARP).  Using
      |  a software iWARP implementation means no special hardware is
      |  necessary.  Likewise, if MPA/DDP can be made to support QUIC,
      |  much of the need for a separate RPC-over-QUIC is moot.  In
      |  addition, it would bring automatically transport layer security
      |  to other RDMA-enabled protocols (such as RPC-over-RDMA).
      |
      |  lars: If changes to the RPC-over-QUIC binding might be desired
      |  in the future, how would they be negotiated/expressed?  Should
      |  a versioned ALPN be used instead of the one from
      |  [I-D.ietf-nfsv4-rpc-tls]?

3.3.  Connections and Streams

   QUIC provides a "stream" abstraction, described in Section 2 of
   [RFC9000].  Each QUIC stream can be unidirectional or bidirectional.
   QUIC supports a nearly unlimited number of concurrent streams per
   connection.






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   Unless explicitly specified, when RPC protocol specifications refer
   to a "connection", this applies to a QUIC connection, not to a
   stream.  As an example, in the case of NFSv4.1 [RFC8881], a
   BIND_CONN_TO_SESSION operation binds a QUIC connection and does not
   need to be repeated for each stream on the connection.

   An RPC Reply MUST be sent over the same connection and stream as the
   Call message with a matching XID.  Forward-direction RPC messages
   MUST be sent over a client-initiated bidirectional stream (stream
   type 0x00).  Reverse-direction RPC messages MUST be sent over a
   server-initiated bidirectional stream (stream type 0x01).  Otherwise,
   unless otherwise explicitly specified, RPC callers are free to use
   streams as they wish, and responders have to accommodate callers that
   do so.

      |  NFS requirement on resends: QUIC allows reconnecting using the
      |  same connection ID, so isn't breaking/reconnection somewhat
      |  ambiguous?  When can a server drop or a client resend?  Any
      |  advice needed for server-side DRC implementations?
      |
      |  lars: I'm not sure I understand what is meant by "reconnecting"
      |  above.  Is this referring to connection migration?  Or a 0-RTT
      |  repeated connection instance?  Something else?
      |
      |  lars: Also, I'm not sure if the use of streams is fully
      |  specified by the above.  Is the intent here to leave it to
      |  callers to decide if they want to use a fresh stream for each
      |  RPC, or reuse an existing stream for a series of RPCs?

4.  Implementation Status

   This section is to be removed before publishing as an RFC.

   This section records the status of known implementations of the
   protocol defined by this specification at the time of posting of this
   Internet-Draft, and is based on a proposal described in [RFC7942].
   The description of implementations in this section is intended to
   assist the IETF in its decision processes in progressing drafts to
   RFCs.

   Please note that the listing of any individual implementation here
   does not imply endorsement by the IETF.  Furthermore, no effort has
   been spent to verify the information presented here that was supplied
   by IETF contributors.  This is not intended as, and must not be
   construed to be, a catalog of available implementations or their
   features.  Readers are advised to note that other implementations may
   exist.




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   There are no known implementations of RPC-over-QUICv1 as described in
   this document.

5.  Security Considerations

   Readers should refer to the discussion of QUIC's transport layer
   security in Section 21 of [RFC9000].

6.  IANA Considerations

   RFC Editor: In the following subsections, please replace RFC-TBD with
   the RFC number assigned to this document.  Furthermore, please remove
   this Editor's Note before this document is published.

6.1.  Netids for RPC-over-QUIC

   Each new RPC transport is assigned one or more RPC "netid" strings.
   These strings are an rpcbind [RFC1833] string naming the underlying
   transport protocol, appropriate message framing, and the format of
   service addresses and ports, among other things.

   This document requests that IANA allocate the following "Netid"
   registry strings in the "ONC RPC Netid" registry, as defined in
   [RFC5665]:

         NC_QUIC    "quic"
         NC_QUIC6   "quic6"

   These netids MUST be used for any transport satisfying the
   requirements described in this document.  The "quic" netid is to be
   used when IPv4 addressing is employed by the underlying transport,
   and "quic6" for IPv6 addressing.  IANA should use this document (RFC-
   TBD) as the reference for the new entries.

      |  lars: Why one per IP address family?  This seems common
      |  practice with netids, but also seems to be a layering
      |  violation?

7.  References

7.1.  Normative References

   [I-D.ietf-nfsv4-rpc-tls]
              Myklebust, T. and C. Lever, "Towards Remote Procedure Call
              Encryption By Default", Work in Progress, Internet-Draft,
              draft-ietf-nfsv4-rpc-tls-11, 23 November 2020,
              <https://datatracker.ietf.org/doc/html/draft-ietf-nfsv4-
              rpc-tls-11>.



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   [RFC1833]  Srinivasan, R., "Binding Protocols for ONC RPC Version 2",
              RFC 1833, DOI 10.17487/RFC1833, August 1995,
              <https://www.rfc-editor.org/rfc/rfc1833>.

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119,
              DOI 10.17487/RFC2119, March 1997,
              <https://www.rfc-editor.org/rfc/rfc2119>.

   [RFC5531]  Thurlow, R., "RPC: Remote Procedure Call Protocol
              Specification Version 2", RFC 5531, DOI 10.17487/RFC5531,
              May 2009, <https://www.rfc-editor.org/rfc/rfc5531>.

   [RFC5665]  Eisler, M., "IANA Considerations for Remote Procedure Call
              (RPC) Network Identifiers and Universal Address Formats",
              RFC 5665, DOI 10.17487/RFC5665, January 2010,
              <https://www.rfc-editor.org/rfc/rfc5665>.

   [RFC8174]  Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
              2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
              May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.

   [RFC9000]  Iyengar, J., Ed. and M. Thomson, Ed., "QUIC: A UDP-Based
              Multiplexed and Secure Transport", RFC 9000,
              DOI 10.17487/RFC9000, May 2021,
              <https://www.rfc-editor.org/rfc/rfc9000>.

   [RFC9001]  Thomson, M., Ed. and S. Turner, Ed., "Using TLS to Secure
              QUIC", RFC 9001, DOI 10.17487/RFC9001, May 2021,
              <https://www.rfc-editor.org/rfc/rfc9001>.

7.2.  Informative References

   [RFC0768]  Postel, J., "User Datagram Protocol", STD 6, RFC 768,
              DOI 10.17487/RFC0768, August 1980,
              <https://www.rfc-editor.org/rfc/rfc768>.

   [RFC0793]  Postel, J., "Transmission Control Protocol", STD 7,
              RFC 793, DOI 10.17487/RFC0793, September 1981,
              <https://www.rfc-editor.org/rfc/rfc793>.

   [RFC7942]  Sheffer, Y. and A. Farrel, "Improving Awareness of Running
              Code: The Implementation Status Section", BCP 205,
              RFC 7942, DOI 10.17487/RFC7942, July 2016,
              <https://www.rfc-editor.org/rfc/rfc7942>.






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   [RFC8881]  Noveck, D., Ed. and C. Lever, "Network File System (NFS)
              Version 4 Minor Version 1 Protocol", RFC 8881,
              DOI 10.17487/RFC8881, August 2020,
              <https://www.rfc-editor.org/rfc/rfc8881>.

Acknowledgments

   The authors express their deepest appreciation for the contributions
   of J.  Bruce Fields who was an original author of this document.  In
   addition, we are indebted to Lars Eggert and the QUIC working group
   for the creation of the QUIC transport protocol.

   The editor is grateful to Bill Baker, Greg Marsden, and Martin
   Thomson for their input and support.

   Special thanks to Transport Area Directors Martin Duke and
   Zaheduzzaman Sarker, NFSV4 Working Group Chairs David Noveck and
   Brian Pawlowski, and NFSV4 Working Group Secretary Thomas Haynes for
   their guidance and oversight.

Authors' Addresses

   Benjamin Coddington
   Red Hat
   United States of America
   Email: bcodding@redhat.com


   Scott Mayhew
   Red Hat
   United States of America
   Email: smayhew@redhat.com


   Charles Lever (editor)
   Oracle Corporation
   United States of America
   Email: chuck.lever@oracle.com













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