Internet DRAFT - draft-piraux-quic-tunnel-tcp
draft-piraux-quic-tunnel-tcp
QUIC Working Group M. Piraux
Internet-Draft O. Bonaventure
Intended status: Experimental UCLouvain
Expires: February 13, 2021 August 12, 2020
Tunneling TCP inside QUIC
draft-piraux-quic-tunnel-tcp-02
Abstract
This document specifies a new operating mode for a QUIC tunnel to
efficiently convey TCP bytestreams.
Status of This Memo
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 3
3. The stream mode . . . . . . . . . . . . . . . . . . . . . . . 3
4. Connection establishment . . . . . . . . . . . . . . . . . . 4
5. Messages format . . . . . . . . . . . . . . . . . . . . . . . 5
5.1. QUIC tunnel stream TLVs . . . . . . . . . . . . . . . . . 5
5.1.1. TCP Connect TLV . . . . . . . . . . . . . . . . . . . 6
5.1.2. TCP Connect OK TLV . . . . . . . . . . . . . . . . . 6
5.1.3. Error TLV . . . . . . . . . . . . . . . . . . . . . . 6
5.1.4. End TLV . . . . . . . . . . . . . . . . . . . . . . . 8
6. Example flows . . . . . . . . . . . . . . . . . . . . . . . . 8
7. Security Considerations . . . . . . . . . . . . . . . . . . . 9
7.1. Denial of Service . . . . . . . . . . . . . . . . . . . . 9
8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 9
8.1. QUIC tunnel stream TLVs . . . . . . . . . . . . . . . . . 9
8.1.1. QUIC tunnel stream TLVs Types . . . . . . . . . . . . 9
8.1.2. QUIC tunnel streams TLVs Error Types . . . . . . . . 9
8.2. QUIC Transport Parameter Registry . . . . . . . . . . . . 10
9. References . . . . . . . . . . . . . . . . . . . . . . . . . 10
9.1. Normative References . . . . . . . . . . . . . . . . . . 10
9.2. Informative References . . . . . . . . . . . . . . . . . 11
Appendix A. Change Log . . . . . . . . . . . . . . . . . . . . . 11
A.1. Since draft-piraux-quic-tunnel-tcp-01 . . . . . . . . . . 11
A.2. Since draft-piraux-quic-tunnel-tcp-00 . . . . . . . . . . 11
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 11
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 11
1. Introduction
The recently proposed QUIC tunnel protocol [I-D.piraux-quic-tunnel]
supports the exchange of IP packets and Ethernet frames over a QUIC
connection. Its two operating modes transports plain packets inside
QUIC frames. Its main advantage is that it supports any network-
layer protocol. 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
to the IP/UDP/QUIC headers of the QUIC connection. For TCP
connections for instance, the per-packet overhead can be large.
In this document, we propose a new operating mode for the QUIC tunnel
protocol, called the stream mode. It takes advantage of the QUIC
streams to efficiently transport TCP bytestreams over a QUIC
connection. Section 3 describes this new mode. Section 5 specifies
the format of the messages introduced by this document. Section 6
contains example flows.
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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. The stream mode
Since QUIC supports multiple streams, another possibility to carry
the data exchanged over TCP connections between the client and the
concentrator is to transport the bytestream of each TCP connection as
one of the bidirectional streams of the QUIC connection. For this,
we base our approach on the 0-RTT Convert protocol
[I-D.ietf-tcpm-converters] that was proposed to ease the deployment
of TCP extensions. In a nutshell, it is an application proxy that
converts TCP connections, allowing the use of new TCP extensions
through an intermediate relay.
We use a similar approach in our stream mode. When a client opens a
stream, it sends at the beginning of the bytestream one or more TLV
messages indicating the IP address and port number of the remote
destination of the bytestream. Their format is detailed in section
Section 5.1. Upon reception of such a TLV message, the concentrator
opens a TCP connection towards the specified destination and connects
the incoming bytestream of the QUIC connection to the bytestream of
the new TCP connection (and similarly in the opposite direction).
Figure 1 summarizes how the new TCP connection is mapped to the QUIC
stream. Actions and events of a TCP connection are translated to
actions and events of the associated QUIC stream, so that a state
transition on one is translated to the other.
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+------------------+-------------------------+
| TCP | QUIC Stream |
+------------------+-------------------------+
| SYN received | Open Stream, send TLVs |
| FIN received | Send Stream FIN |
| RST received | Send STOP_SENDING |
| | Send RESET_STREAM |
| Data received | Send Stream data |
+------------------+-------------------------+
+-------------------------------+------------+
| QUIC Stream | TCP |
+-------------------------------+------------+
| Stream opened, TLVs received | Send SYN |
| Stream FIN received | Send FIN |
| STOP_SENDING received | Send RST |
| RESET_STREAM received | Send RST |
| Stream data received | Send data |
+-------------------------------+------------+
Figure 1: TCP connection to QUIC stream mapping
When sending STOP_SENDING or RESET_STREAM frames in response to the
receipt of a TCP RST, QUIC tunnel peers MUST use the application
protocol error code 0x00 (TCP_CONNECTION_RESET).
The QUIC stream-level flow control can be tuned to match the receive
window size of the corresponding TCP connection, so that no excessive
data needs to be buffered.
4. Connection establishment
The connection establishment follows the requirements described in
Section 5 of [I-D.piraux-quic-tunnel].
In addition, the support of the stream mode is negotiated during the
connection establishment by including the quic_tunnel_stream_mode
transport parameter (value TBD). The parameter value has no meaning
and SHOULD be null.
During the connection establishment, the concentrator can control the
number of TCP bytestreams that can be opened initially by setting the
initial_max_streams_bidi QUIC transport parameter as defined in
[I-D.ietf-quic-transport].
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5. Messages format
In the following sections, we specify the format of each message
introduced in this document. They are encoded using the TLV format
described in [I-D.piraux-quic-tunnel].
5.1. QUIC tunnel stream TLVs
When using the stream mode, one or more messages are used to trigger
and confirm the establishment of a connection towards the final
destination for a given stream. Those messages are exchanged on this
QUIC stream before the TCP connection bytestream. This section
describes the format of these messages.
This document specifies the following QUIC tunnel stream TLVs:
+------+----------+-----------------------------+
| Type | Size | Name |
+------+----------+-----------------------------+
| 0x00 | 20 bytes | TCP Connect TLV |
| 0x01 | 2 bytes | TCP Connect OK TLV |
| 0x02 | Variable | Error TLV |
| 0xff | 2 bytes | End TLV |
+------+----------+-----------------------------+
Figure 2: QUIC tunnel stream TLVs
The TCP Connect TLV is used to request the establishment a TCP
connection by the concentrator towards the final destination. The
TCP Connect OK TLV confirms the establishment of this TCP connection.
The Error TLV is used to indicate any error that occurred during the
establishment of a TCP connection. Finally, the End TLV marks the
end of the series of TLVs and the start of the bytestream on a given
QUIC stream. These TLVs are detailed in the following sections.
Future versions of this document may define new TLVs. The End TLV
allows a QUIC tunnel peer to send several TLVs before the start of
the bytestream.
Offset 0 Offset 20 Offset 22
| | |
Client v v v
+-----------------+---------+----------------
Stream 0 | TCP Connect TLV | End TLV | TCP bytestream ...
+-----------------+---------+----------------
Figure 3: Example of use of QUIC tunnel stream TLVs
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Figure 3 illustrates an example of use of QUIC tunnel streams TLVs.
In this example, the client opens Stream 0 and sends two TLVs. The
first one requests the concentrator to establish a new TCP
connection. The second TLV marks the end of the series of TLV and
the start of the TCP bytestream.
5.1.1. TCP Connect TLV
The TCP Connect TLV indicates the final destination of the TCP
connection associated to a given QUIC stream. The fields Remote Peer
Port and Remote Peer IP Address contain the destination port number
and IP address of the final destination.
The Remote Peer IP Address MUST be encoded as an IPv6 address. IPv4
addresses MUST be encoded using the IPv4-Mapped IPv6 Address format
defined in [RFC4291]. Further, the Remote Peer IP address field MUST
NOT include multicast, broadcast, and host loopback addresses
[RFC6890].
A QUIC tunnel peer MUST NOT send more than one TCP Connect TLV per
QUIC stream. A QUIC tunnel peer MUST NOT send a TCP Connect TLV on
non-self initiated streams.
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) | Remote Peer Port (16) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| |
| Remote Peer IP Address (128) |
| |
| |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 4: TCP Connect TLV
5.1.2. TCP Connect OK TLV
The TCP Connect OK TLV does not contain a value. Its presence
confirms the successful establishment of the requested TCP connection
to the final destination. A QUIC peer MUST NOT send a TCP Connect OK
TLV on self-initiated streams.
5.1.3. Error TLV
The Error TLV indicates out-of-band errors that occurred during the
establishment of the TCP connection to the final destination. These
errors can be ICMP Destination Unreachable messages for instance. In
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this case the ICMP packet received by the concentrator is copied
inside the Error Payload field.
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) | Error Code (16) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| [Error Payload (*)] |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
Figure 5: Error TLV
The following bytestream-level error codes are defined in this
document:
+------+---------------------------+
| Code | Name |
+------+---------------------------+
| 0x0 | Protocol Violation |
| 0x1 | ICMP Packet Received |
| 0x2 | Malformed TLV |
| 0x3 | Network Failure |
+------+---------------------------+
Figure 6: Bytestream-level Error Codes
o Protocol Violation (0x0): A general error code for all non-
conforming behaviors encountered. A QUIC tunnel peer SHOULD use a
more specific error code when possible.
o ICMP Packet Received (0x1): This code indicates that the
concentrator received an ICMP packet while trying to create the
associated TCP connection. The Error Payload contains the packet.
o Malformed TLV (0x2): This code indicates that a received TLV was
not successfully parsed or formed. A peer receiving a TCP Connect
TLV with an invalid IP address MUST send an Error TLV with this
error code.
o Network Failure (0x3): This codes indicates that a network failure
prevented the establishment of the connection.
After sending one or more Error TLVs, the sender MUST send an End TLV
and terminate the stream, i.e. set the FIN bit after the End TLV.
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5.1.4. End TLV
The End TLV does not contain a value. Its existence signals the end
of the series of TLVs. The next byte in the QUIC stream after this
TLV is part of of the tunneled bytestream.
6. Example flows
This section illustrates the different messages described previously
and how they are used in a QUIC tunnel connection. For QUIC STREAM
frames, we use the following syntax: STREAM[ID, Stream Data [, FIN]].
The first element is the Stream ID, the second is the Stream Data
contained in the frame and the last one is optional and indicates
that the FIN bit is set.
Client Concentrator Final Destination
| STREAM[0, "TCP Connect, End"] || |
|------------------------------>|| SYN |
| ||==============================>|
| || SYN+ACK |
|STREAM[0,"TCP Connect OK, End"]||<==============================|
|<------------------------------|| |
| STREAM[0, "bytestream data"] || |
|------------------------------>|| bytestream data, ACK |
| ||==============================>|
| || bytestream data, ACK |
| STREAM[0, "bytestream data"] ||<==============================|
|<------------------------------|| FIN |
| STREAM[0, "", FIN] ||<==============================|
|<------------------------------|| ACK |
| STREAM[0, "", FIN] ||==============================>|
|------------------------------>|| FIN |
| ||==============================>|
| || ACK |
| ||<==============================|
Legend:
--- QUIC connection
=== TCP connection
Figure 7: Example flow for the stream mode
On Figure 7, the client is initiating a TCP connection in stream mode
to the Final Destination. A request and a response are exchanged,
then the connection is torn down gracefully. A remote-initiated
connection accepted by the concentrator on behalf of the client would
have the order and the direction of all messages reversed.
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7. Security Considerations
7.1. Denial of Service
There is a risk of an amplification attack when the Concentrator
sends a TCP SYN in response of a TCP Connect TLV. When a TCP SYN is
larger than the client request, the Concentrator amplifies the client
traffic. To mitigate such attacks, the Concentrator SHOULD rate
limit the number of pending TCP Connect from a given client.
8. IANA Considerations
8.1. QUIC tunnel stream TLVs
IANA is requested to create a new "QUIC tunnel stream Parameters"
registry.
The following subsections detail new registries within "QUIC tunnel
stream Parameters" registry.
8.1.1. QUIC tunnel stream TLVs Types
IANA is request to create the "QUIC tunnel stream TLVs Types" sub-
registry. 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 | TCP Connect TLV | [This-Doc] |
| 1 | TCP Connect OK TLV | [This-Doc] |
| 2 | Error TLV | [This-Doc] |
| 255 | End TLV | [This-Doc] |
+------+-----------------------------+------------+
8.1.2. QUIC tunnel streams TLVs Error Types
IANA is request to create the "QUIC tunnel stream TLVs Error Types"
sub-registry. 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:
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+------+---------------------------+------------+
| Code | Name | Reference |
+------+---------------------------+------------+
| 0 | Protocol Violation | [This-Doc] |
| 1 | ICMP packet received | [This-Doc] |
| 2 | Malformed TLV | [This-Doc] |
| 3 | Network Failure | [This-Doc] |
+------+---------------------------+------------+
8.2. QUIC Transport Parameter Registry
This document defines a new transport parameter for the negotiation
of the stream mode. The following entry in Table 1 should be added
to the "QUIC Transport Parameters" registry under the "QUIC Protocol"
heading.
+-------+-------------------------+---------------+
| Value | Parameter Name | Specification |
+-------+-------------------------+---------------+
| TBD | quic_tunnel_stream_mode | Section 4 |
+-------+-------------------------+---------------+
Table 1: Addition to QUIC Transport Parameters Entries
9. References
9.1. Normative References
[I-D.piraux-quic-tunnel]
Piraux, M., Bonaventure, O., and A. Masputra, "Tunneling
Internet protocols inside QUIC", draft-piraux-quic-
tunnel-02 (work in progress), July 2020.
[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>.
[RFC4291] Hinden, R. and S. Deering, "IP Version 6 Addressing
Architecture", RFC 4291, DOI 10.17487/RFC4291, February
2006, <https://www.rfc-editor.org/info/rfc4291>.
[RFC6890] Cotton, M., Vegoda, L., Bonica, R., Ed., and B. Haberman,
"Special-Purpose IP Address Registries", BCP 153,
RFC 6890, DOI 10.17487/RFC6890, April 2013,
<https://www.rfc-editor.org/info/rfc6890>.
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[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
[I-D.ietf-quic-transport]
Iyengar, J. and M. Thomson, "QUIC: A UDP-Based Multiplexed
and Secure Transport", draft-ietf-quic-transport-29 (work
in progress), June 2020.
[I-D.ietf-tcpm-converters]
Bonaventure, O., Boucadair, M., Gundavelli, S., Seo, S.,
and B. Hesmans, "0-RTT TCP Convert Protocol", draft-ietf-
tcpm-converters-19 (work in progress), March 2020.
[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>.
Appendix A. Change Log
A.1. Since draft-piraux-quic-tunnel-tcp-01
o Nits
A.2. Since draft-piraux-quic-tunnel-tcp-00
o Add the quic_tunnel_stream_mode transport parameter for
negotiation
Acknowledgments
This documents draws heavily on the initial version of
[I-D.piraux-quic-tunnel]. Their contributors are thanked again here.
This work was partially supported by the MQUIC project.
Authors' Addresses
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Maxime Piraux
UCLouvain
Email: maxime.piraux@uclouvain.be
Olivier Bonaventure
UCLouvain
Email: olivier.bonaventure@uclouvain.be
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