Internet Engineering Task Force (IETF) R. Hamilton
Request for Comments: 9220 Google
Category: Standards Track June 2022
ISSN: 2070-1721
Bootstrapping WebSockets with HTTP/3
Abstract
The mechanism for running the WebSocket Protocol over a single stream
of an HTTP/2 connection is equally applicable to HTTP/3, but the
HTTP-version-specific details need to be specified. This document
describes how the mechanism is adapted for HTTP/3.
Status of This Memo
This is an Internet Standards Track document.
This document is a product of the Internet Engineering Task Force
(IETF). It represents the consensus of the IETF community. It has
received public review and has been approved for publication by the
Internet Engineering Steering Group (IESG). Further information on
Internet Standards is available in Section 2 of RFC 7841.
Information about the current status of this document, any errata,
and how to provide feedback on it may be obtained at
https://www.rfc-editor.org/info/rfc9220.
Copyright Notice
Copyright (c) 2022 IETF Trust and the persons identified as the
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Table of Contents
1. Introduction
2. Conventions and Definitions
3. WebSockets Upgrade over HTTP/3
4. Security Considerations
5. IANA Considerations
6. Normative References
Acknowledgments
Author's Address
1. Introduction
"Bootstrapping WebSockets with HTTP/2" [RFC8441] defines an extension
to HTTP/2 [HTTP/2] that is also useful in HTTP/3 [HTTP/3]. This
extension makes use of an HTTP/2 setting. Appendix A.3 of [HTTP/3]
gives some guidance on what changes (if any) are appropriate when
porting settings from HTTP/2 to HTTP/3.
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. WebSockets Upgrade over HTTP/3
[RFC8441] defines a mechanism for running the WebSocket Protocol
[RFC6455] over a single stream of an HTTP/2 connection. It defines
an Extended CONNECT method that specifies a new ":protocol" pseudo-
header field and new semantics for the ":path" and ":authority"
pseudo-header fields. It also defines a new HTTP/2 setting sent by a
server to allow the client to use Extended CONNECT.
The semantics of the pseudo-header fields and setting are identical
to those in HTTP/2 as defined in [RFC8441]. Appendix A.3 of [HTTP/3]
requires that HTTP/3 settings be registered separately for HTTP/3.
The SETTINGS_ENABLE_CONNECT_PROTOCOL value is 0x08 (decimal 8), as in
HTTP/2.
If a server advertises support for Extended CONNECT but receives an
Extended CONNECT request with a ":protocol" value that is unknown or
is not supported, the server SHOULD respond to the request with a 501
(Not Implemented) status code (Section 15.6.2 of [HTTP]). A server
MAY provide more information via a "problem details" response
[RFC7807].
The HTTP/3 stream closure is also analogous to the TCP connection
closure of [RFC6455]. Orderly TCP-level closures are represented as
a FIN bit on the stream (Section 4.4 of [HTTP/3]). RST exceptions
are represented with a stream error (Section 8 of [HTTP/3]) of type
H3_REQUEST_CANCELLED (Section 8.1 of [HTTP/3]).
4. Security Considerations
This document introduces no new security considerations beyond those
discussed in [RFC8441].
5. IANA Considerations
This document registers a new setting in the "HTTP/3 Settings"
registry (Section 11.2.2 of [HTTP/3]).
Value: 0x08
Setting Name: SETTINGS_ENABLE_CONNECT_PROTOCOL
Default: 0
Status: permanent
Specification: This document
Change Controller: IETF
Contact: HTTP Working Group (ietf-http-wg@w3.org)
6. Normative References
[HTTP] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "HTTP Semantics", STD 97, RFC 9110,
DOI 10.17487/RFC9110, June 2022,
<https://www.rfc-editor.org/info/rfc9110>.
[HTTP/2] Thomson, M., Ed. and C. Benfield, Ed., "HTTP/2", RFC 9113,
DOI 10.17487/RFC9113, June 2022,
<https://www.rfc-editor.org/info/rfc9113>.
[HTTP/3] Bishop, M., Ed., "HTTP/3", RFC 9114, DOI 10.17487/RFC9114,
June 2022, <https://www.rfc-editor.org/info/rfc9114>.
[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>.
[RFC6455] Fette, I. and A. Melnikov, "The WebSocket Protocol",
RFC 6455, DOI 10.17487/RFC6455, December 2011,
<https://www.rfc-editor.org/info/rfc6455>.
[RFC7807] Nottingham, M. and E. Wilde, "Problem Details for HTTP
APIs", RFC 7807, DOI 10.17487/RFC7807, March 2016,
<https://www.rfc-editor.org/info/rfc7807>.
[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>.
[RFC8441] McManus, P., "Bootstrapping WebSockets with HTTP/2",
RFC 8441, DOI 10.17487/RFC8441, September 2018,
<https://www.rfc-editor.org/info/rfc8441>.
Acknowledgments
This document had reviews and input from many contributors in the
IETF HTTP and QUIC Working Groups, with substantive input from David
Schinazi, Martin Thomson, Lucas Pardue, Mike Bishop, Dragana
Damjanovic, Mark Nottingham, and Julian Reschke.
Author's Address
Ryan Hamilton
Google
Email: rch@google.com