Internet DRAFT - draft-piraux-intarea-quic-tunnel-session
draft-piraux-intarea-quic-tunnel-session
Internet Area Working Group M. Piraux
Internet-Draft O. Bonaventure
Intended status: Experimental UCLouvain
Expires: 6 May 2021 A. Masputra
Apple Inc.
2 November 2020
Session mode for multiple QUIC Tunnels
draft-piraux-intarea-quic-tunnel-session-00
Abstract
This document specifies methods for grouping QUIC tunnel connections
in a single session enabling the exchange of packets of Internet
protocols over several QUIC connections.
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
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This Internet-Draft will expire on 6 May 2021.
Copyright Notice
Copyright (c) 2020 IETF Trust and the persons identified as the
document authors. All rights reserved.
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Please review these documents carefully, as they describe your rights
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. Reference environment . . . . . . . . . . . . . . . . . . . . 3
4. The tunnel session mode . . . . . . . . . . . . . . . . . . . 4
4.1. Joining a tunneling session . . . . . . . . . . . . . . . 6
4.1.1. Coordinate use of the Packet Tag . . . . . . . . . . 7
5. Connection establishment . . . . . . . . . . . . . . . . . . 7
6. Messages format . . . . . . . . . . . . . . . . . . . . . . . 7
6.1. QUIC tunnel control TLVs . . . . . . . . . . . . . . . . 8
6.1.1. New Session TLV . . . . . . . . . . . . . . . . . . . 8
6.1.2. Session ID TLV . . . . . . . . . . . . . . . . . . . 9
6.1.3. Join Session TLV . . . . . . . . . . . . . . . . . . 9
7. Security Considerations . . . . . . . . . . . . . . . . . . . 10
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 10
8.1. Registration of QUIC tunnel Identification String . . . . 10
8.2. QUIC tunnel control TLVs . . . . . . . . . . . . . . . . 10
8.2.1. QUIC tunnel control TLVs Types . . . . . . . . . . . 10
8.3. QUIC tunnel control Error Codes . . . . . . . . . . . . . 11
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11
9.1. Normative References . . . . . . . . . . . . . . . . . . 11
9.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 12
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 13
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 13
1. Introduction
Mobile devices such as laptops, smartphones or tablets have different
requirements than the traditional fixed devices. These mobile
devices often change their network attachment. They are often
attached to trusted networks, but sometimes they need to be connected
to untrusted networks where their communications can be eavesdropped,
filtered or modified. In these situations, the classical approach is
to rely on VPN protocols such as DTLS or IPSec. These VPN protocols
provide the encryption and authentication functions to protect those
mobile clients from malicious behaviors in untrusted networks.
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Today's mobile devices are often multihomed and many expect to be
able to perform seamless handovers from one access network to another
without breaking the established VPN sessions. In some situations it
can also be beneficial to combine two or more access networks
together to increase the available host bandwidth. A protocol such
as Multipath TCP [RFC6824] supports those handovers and allows
aggregating the bandwidth of different access links. It could be
combined with single-path VPN protocols to support both seamless
handovers and bandwidth aggregation above VPN tunnels.
Unfortunately, Multipath TCP is not yet deployed on most Internet
servers and thus few applications would benefit from such a use case.
This document explores how QUIC could be used to enable multi-homed
mobile devices to communicate securely in untrusted networks.
This document is organized as follows. Section 3 describes the
reference environment. Then, we propose a new mode of operation,
explained in Section 4, that use the recently proposed datagram
extension ([I-D.pauly-quic-datagram]) for QUIC to transport plain IP
packets over a QUIC connection. Section 5 specifies how a connection
is established in this document proposal. Section 6 details the
format of the messages introduced by this document.
2. Conventions and Definitions
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. Reference environment
The reference environment is illustrated in Figure 1, in which a
client-initiated flow is tunneled through the concentrator.
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+---------+
.----| Access |----.
| | network | |
| | A | |
v +---------- v +-------------+
+--------+ +--------------+ | Final |
| Client | | Concentrator |<===\ ... \===>| destination |
+--------+ +--------------+ | server |
^ +---------+ ^ +-------------+
| | Access | |
| | network | | Legend:
.----| B |----. --- QUIC connection
+---------+ === Tunneled flow
Figure 1: Example environment
Such a multihomed client would like to benefit from the different
access networks available to reach the concentrator. These access
networks can be used for load-sharing, failover or other purposes.
One possibility to efficiently use these two access networks is to
rely on the proposed Multipath extensions to QUIC
[I-D.deconinck-quic-multipath]. Another approach is to create one
QUIC connection using the single-path QUIC protocol
[I-D.ietf-quic-transport] over each access network and glue these
different connections together in a single session on the
concentrator. Given the migration capabilities of QUIC, this
approach could support failover with a single active QUIC connection
at a time.
4. The tunnel session mode
The "tunnel session" mode enables the client and the concentrator to
exchange packets of several network protocols through the QUIC tunnel
connection at the same time. It also leverages the QUIC datagram
extension [I-D.pauly-quic-datagram].
This document specifies the following format for encoding packets in
QUIC DATAGRAM frame. It allows encoding packets from several
protocols by identifying the corresponding protocol of the packet in
each QUIC DATAGRAM frame. Figure 2 describes this encoding.
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Protocol Type (16) | Packet Tag (16) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Packet (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
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Figure 2: Encoding packets in QUIC DATAGRAM frame
This encoding defines three fields.
* Protocol Type: The Protocol Type field contains the protocol type
of the payload packet. The values for the different protocols are
defined as "ETHER TYPES" in [IANA-ETHER-TYPES]. A QUIC tunnel
that receives a Protocol Type representing an unsupported protocol
MAY drop the associated Packet. QUIC tunnel endpoints willing to
exchange Ethernet frames can use the value 0x6558 for
[Transparent-Ethernet-Bridging].
* Packet Tag: An opaque 16-bit value. The QUIC tunnel application
is free to decide its semantic value. For instance, a QUIC tunnel
endpoint MAY encode the sending order of packets in the Packet
Tag, e.g. as a timestamp or a sequence number, to allow reordering
on the receiver.
* Packet: The packet conveyed inside the QUIC tunnel connection.
,->+----------+
| | IP |
QUIC packet | +----------+
containing | | UDP |
a DATAGRAM | +----------+
frame | | QUIC |
| |..........|
| | DATAGRAM |
| | P. Type |
| | P. Tag |
| |+--------+|<-.
| || IP || |
| |+--------+| | Tunneled
| || UDP || | UDP packet
| |+--------+| |
| | .... |<-.
`->+----------+
Figure 3: QUIC packet sent by the client when tunneling a UDP packet
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Figure 3 illustrates how a UDP packet is tunneled using the tunnel
session mode. The main advantage of the tunnel session mode is that
it supports IP and any protocol above the network layer. Any IP
packet can be transported using the datagram extension over a QUIC
connection. However, this advantage comes with a large per-packet
overhead since each packet contains both a network and a transport
header. All these headers must be transmitted in addition with the
IP/UDP/QUIC headers of the QUIC connection. For TCP connections for
instance, the per-packet overhead can be large.
4.1. Joining a tunneling session
If the client is multihomed, it can use Multipath QUIC
[I-D.deconinck-quic-multipath] to efficiently use its different
access networks. This version of the document does not elaborate in
details on this possibility. If the concentrator does not support
Multipath QUIC, then the client creates several QUIC connections and
joins them at the application layer. This works as illustrated in
figure Figure 4. Each message is exchanged over a dedicated
unidirectional QUIC stream. Their format is detailed in Section 6.
When the client opens the first QUIC connection with the
concentrator, (1) it can request a QUIC tunnel session identifier.
(2) The concentrator replies with a variable-length opaque value that
identifies the QUIC tunneling session. When opening a QUIC
connection over another access network, (3) the client can send this
identifier to join the QUIC tunneling session. The concentrator
matches the session identifier with the existing session with the
client. It can then use both sessions to reach the client and
receive tunneled packets from the client.
1-Req. Sess. ID->
.-----------------------------.
| <-Sess. ID.-2 |
v v
+--------+ +--------------+
| Client | | Concentrator |
+--------+ +--------------+
^ ^
| 3-Join. Sess.-> | Legend:
.-----------------------------. --- QUIC connection
Figure 4: Creating sessions over different access networks
Joining a tunneling session allows grouping several QUIC connections
to the concentrator. Each endpoint can then coordinate the use of
the Packet Tag across the tunneling session as presented in
Section 4.1.1.
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Both QUIC tunnel endpoints open their first unidirectional stream
(i.e. stream 2 and 3), hereafter named the QUIC tunnel control
stream, to exchange these messages. A QUIC tunnel endpoint MUST NOT
close its control stream and SHOULD provide enough flow control
credit to its peer.
The messages format used for this purpose are described in Section 6.
The client initiates the procedure and MAY either start a new session
or join an existing session. This negotiation MUST NOT take place
more than once per QUIC connection.
4.1.1. Coordinate use of the Packet Tag
When using the tunnel session mode, each packet is associated with a
16-bit value called Packet Tag. This document leaves defining the
meaning of this value to implementations. This section provides some
examples on how it can be used to implement packet reordering across
several QUIC tunnel connections grouped in a tunneling session.
A first simple example of use is to encode the timestamp at which the
datagram was sent. Using a millisecond precision and encoding the 16
lower bits of the timestamp makes the value wrapping around in a bit
more than 65 seconds.
Another example of use is to maintain a value counting the datagrams
sent over all QUIC tunnel connections of the tunneling session. The
16-bit value allows distinguishing at most 32768 packets in flight.
The QUIC tunnel receiver can then distinguish, buffer and reorder
packets based on this value. Mechanisms for managing the datagram
buffer and negotiating the use of the Packet Tag are out of scope of
this document.
5. Connection establishment
During connection establishment, the tunnel session mode support is
indicated by setting the ALPN token "qt-session" in the TLS
handshake. Draft-version implementations MAY specify a particular
draft version by suffixing the token, e.g. "qt-session-00" refers to
the first version of this document.
6. Messages format
In the following sections, we specify the format of each message
introduced in this document. They are encoded as TLVs, following the
format defined in Section 7 of [I-D.piraux-intarea-quic-tunnel].
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6.1. QUIC tunnel control TLVs
This document specifies additional QUIC tunnel control TLVs:
+------+----------+--------------+----------------+-------------------+
| Type | Size | Sender | Mode | Name |
+------+----------+--------------+----------------+-------------------+
| 0x01 | Variable | Client | tunnel session | New Session TLV |
| 0x02 | Variable | Concentrator | tunnel session | Session ID TLV |
| 0x03 | Variable | Client | tunnel session | Join Session TLV |
+------+----------+--------------+----------------+-------------------+
Figure 5: QUIC tunnel control TLVs
The New Session TLV is used by the client to initiate a new tunneling
session. The Session ID TLV is used by the concentrator to
communicate to the client the Session ID identifying this tunneling
session. The Join Session TLV is used to join a given tunneling
session, identified by a Session ID. All QUIC these tunnel control
TLVs MUST NOT be sent on other streams than the QUIC tunnel control
streams.
When the tunnel session mode is in use, the Access Report TLV defined
in Section 7.1.1 of [I-D.piraux-intarea-quic-tunnel] MUST be sent on
other streams than the QUIC tunnel control stream.
6.1.1. New Session TLV
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (8) | Length (8) | [QoS Flow Indication (*)] ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 6: New Session ID TLV
The New Session TLV contains an optional value. It initiates a new
tunneling session at the concentrator, and can contain an opaque
value giving an indication on the type of traffic conveyed over this
session. The concentrator can use this indication for QoS purposes
for instance.
The concentrator MUST send a Session ID TLV in response, with the
Session ID corresponding to the tunneling session created. After
sending a New Session TLV, the client MUST close the QUIC tunnel
control stream.
The concentrator MUST NOT send New Session TLVs.
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6.1.2. Session ID TLV
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (8) | Length (8) | Session ID (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 7: Session ID TLV
The Session ID TLV contains an opaque value that identifies the
current tunneling session. It can be used by the client in
subsequent QUIC connections to join them to this tunneling session.
The concentrator MUST send a Session ID TLV in response of a New
Session TLV, with the Session ID corresponding to the tunneling
session created.
The client MUST NOT send a Session ID TLV. The concentrator MUST
close the QUIC tunnel control stream after sending a Session ID TLV.
6.1.3. Join Session TLV
1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Type (8) | Length (8) | Session ID (*) ...
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 8: Join Session TLV
The Join Session TLV contains an opaque value that identifies a
tunneling session to join. The client can send a Join Session TLV to
join the QUIC connection to a particular tunneling session. The
tunneling session is identified by the Session ID. After sending a
Join Session TLV, the client MUST close the QUIC tunnel control
stream.
The concentrator MUST NOT send Join Session TLVs. After receiving a
Join Session TLV, the concentrator MUST use the Session ID to join
this QUIC connection to the tunneling session. Joining the tunneling
session implies merging the state of this QUIC tunnel connection to
the session. A successful joining of connection is indicated by the
closure of the QUIC tunnel control stream of the concentrator.
In cases of failure when joining a tunneling session, the
concentrator MUST send a RESET_STREAM with an application error code
discerning the cause of the failure. The possible codes are listed
below:
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* UNKNOWN_ERROR (0x0): An unknown error occurred when joining the
tunneling session. QUIC tunnel endpoints SHOULD use more specific
error codes when applicable.
* UNKNOWN_SESSION_ID (0x1): The Session ID used in the Join Session
TLV is not a valid ID. It was not issued in a Session ID TLV or
refers to an expired tunneling session.
* CONFLICTING_STATE (0x2): The current state of the QUIC tunnel
connection could not be merged with the tunneling session.
7. Security Considerations
The security considerations of [I-D.piraux-intarea-quic-tunnel] are
also applicable to this document.
8. IANA Considerations
8.1. Registration of QUIC tunnel Identification String
This document creates a new registration for the identification of
the QUIC tunnel protocol in the "Application Layer Protocol
Negotiation (ALPN) Protocol IDs" registry established in [RFC7301].
The "qt-session" string identifies the QUIC tunnel protocol tunnel
session mode.
Protocol: QUIC Tunnel session mode
Identification Sequence: 0x71 0x74 0x2d 0x73 0x65 0x73 0x73 0x69
0x6f 0x6e ("qt-session")
Specification: This document
8.2. QUIC tunnel control TLVs
The following subsections detail new registries within "QUIC tunnel
control Parameters" registry.
8.2.1. QUIC tunnel control TLVs Types
This document creates three new registrations to identify the QUIC
tunnel control TLVs defined in this document in the "QUIC tunnel
control TLVs Types" sub-registry defined in
[I-D.piraux-intarea-quic-tunnel].
The values to be added in the registry are as follows:
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+------+-----------------------+------------+
| Code | Name | Reference |
+------+-----------------------+------------+
| 1 | New Session TLV | [This-Doc] |
| 2 | Session ID TLV | [This-Doc] |
| 3 | Join Session TLV | [This-Doc] |
+------+-----------------------+------------+
8.3. QUIC tunnel control Error Codes
This document establishes a registry for QUIC tunnel control stream
error codes. The "QUIC tunnel control Error Code" registry manages a
62-bit space. New values are assigned via IETF Review (Section 4.8
of [RFC8126]).
The initial values to be assigned at the creation of the registry are
as follows:
+------+-----------------------+------------+
| Code | Name | Reference |
+------+-----------------------+------------+
| 0 | UNKNOWN_ERROR | [This-Doc] |
| 1 | UNKNOWN_SESSION_ID | [This-Doc] |
| 2 | CONFLICTING_STATE | [This-Doc] |
+------+-----------------------+------------+
9. References
9.1. Normative References
[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/info/rfc2119>.
[I-D.piraux-intarea-quic-tunnel]
Piraux, M., Bonaventure, O., and A. Masputra, "Tunneling
Internet protocols inside QUIC", Work in Progress,
Internet-Draft, draft-piraux-intarea-quic-tunnel-00, 2
November 2020, <http://www.ietf.org/internet-drafts/draft-
piraux-intarea-quic-tunnel-00.txt>.
[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/info/rfc8174>.
9.2. Informative References
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[I-D.pauly-quic-datagram]
Pauly, T., Kinnear, E., and D. Schinazi, "An Unreliable
Datagram Extension to QUIC", Work in Progress, Internet-
Draft, draft-pauly-quic-datagram-05, 4 November 2019,
<http://www.ietf.org/internet-drafts/draft-pauly-quic-
datagram-05.txt>.
[I-D.ietf-quic-transport]
Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
and Secure Transport", Work in Progress, Internet-Draft,
draft-ietf-quic-transport-32, 20 October 2020,
<http://www.ietf.org/internet-drafts/draft-ietf-quic-
transport-32.txt>.
[I-D.deconinck-quic-multipath]
Coninck, Q. and O. Bonaventure, "Multipath Extensions for
QUIC (MP-QUIC)", Work in Progress, Internet-Draft, draft-
deconinck-quic-multipath-05, 20 August 2020,
<http://www.ietf.org/internet-drafts/draft-deconinck-quic-
multipath-05.txt>.
[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
"Transport Layer Security (TLS) Application-Layer Protocol
Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
July 2014, <https://www.rfc-editor.org/info/rfc7301>.
[RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for
Writing an IANA Considerations Section in RFCs", BCP 26,
RFC 8126, DOI 10.17487/RFC8126, June 2017,
<https://www.rfc-editor.org/info/rfc8126>.
[RFC6824] Ford, A., Raiciu, C., Handley, M., and O. Bonaventure,
"TCP Extensions for Multipath Operation with Multiple
Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013,
<https://www.rfc-editor.org/info/rfc6824>.
[IANA-ETHER-TYPES]
"IANA ETHER TYPES", https://www.iana.org/assignments/ieee-
802-numbers/ieee-802-numbers.txt , 2019.
[Transparent-Ethernet-Bridging]
Hanks, S., Li, T., Farinacci, D., and P. Traina, "Generic
Routing Encapsulation (GRE)", RFC 1701,
DOI 10.17487/RFC1701, October 1994,
<https://www.rfc-editor.org/info/rfc1701>.
Appendix A. Change Log
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Acknowledgments
Authors' Addresses
Maxime Piraux
UCLouvain
Email: maxime.piraux@uclouvain.be
Olivier Bonaventure
UCLouvain
Email: olivier.bonaventure@uclouvain.be
Adi Masputra
Apple Inc.
Email: adi@apple.com
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