Bootstrapping WebSockets with HTTP/2
RFC 8441
| Document | Type |
RFC - Proposed Standard
(September 2018; Errata)
Updates RFC 6455
|
|
|---|---|---|---|
| Last updated | 2018-09-21 | ||
| Replaces | draft-mcmanus-httpbis-h2-websockets | ||
| Stream | IETF | ||
| Formats | plain text pdf html bibtex | ||
| Reviews | |||
| Stream | WG state | Submitted to IESG for Publication | |
| Document shepherd | Mark Nottingham | ||
| Shepherd write-up | Show (last changed 2018-05-07) | ||
| IESG | IESG state | RFC 8441 (Proposed Standard) | |
| Consensus Boilerplate | Yes | ||
| Telechat date | |||
| Responsible AD | Alexey Melnikov | ||
| Send notices to | Mark Nottingham <mnot@mnot.net> | ||
| IANA | IANA review state | IANA OK - Actions Needed | |
| IANA action state | RFC-Ed-Ack | ||
Internet Engineering Task Force (IETF) P. McManus
Request for Comments: 8441 Mozilla
Updates: 6455 September 2018
Category: Standards Track
ISSN: 2070-1721
Bootstrapping WebSockets with HTTP/2
Abstract
This document defines a mechanism for running the WebSocket Protocol
(RFC 6455) over a single stream of an HTTP/2 connection.
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/rfc8441.
Copyright Notice
Copyright (c) 2018 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 Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License.
McManus Standards Track [Page 1]
RFC 8441 H2 WebSockets September 2018
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 3
3. The SETTINGS_ENABLE_CONNECT_PROTOCOL SETTINGS Parameter . . . 3
4. The Extended CONNECT Method . . . . . . . . . . . . . . . . . 4
5. Using Extended CONNECT to Bootstrap the WebSocket Protocol . 4
5.1. Example . . . . . . . . . . . . . . . . . . . . . . . . . 6
6. Design Considerations . . . . . . . . . . . . . . . . . . . . 6
7. About Intermediaries . . . . . . . . . . . . . . . . . . . . 6
8. Security Considerations . . . . . . . . . . . . . . . . . . . 7
9. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 7
9.1. A New HTTP/2 Setting . . . . . . . . . . . . . . . . . . 7
9.2. A New HTTP Upgrade Token . . . . . . . . . . . . . . . . 7
10. Normative References . . . . . . . . . . . . . . . . . . . . 8
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 8
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction
The Hypertext Transfer Protocol (HTTP) [RFC7230] provides compatible
resource-level semantics across different versions, but it does not
offer compatibility at the connection-management level. Other
protocols that rely on connection-management details of HTTP, such as
WebSockets, must be updated for new versions of HTTP.
The WebSocket Protocol [RFC6455] uses the HTTP/1.1 Upgrade mechanism
(Section 6.7 of [RFC7230]) to transition a TCP connection from HTTP
into a WebSocket connection. A different approach must be taken with
HTTP/2 [RFC7540]. Due to its multiplexing nature, HTTP/2 does not
allow connection-wide header fields or status codes, such as the
Upgrade and Connection request-header fields or the 101 (Switching
Protocols) response code. These are all required by the [RFC6455]
opening handshake.
Being able to bootstrap WebSockets from HTTP/2 allows one TCP
connection to be shared by both protocols and extends HTTP/2's more
efficient use of the network to WebSockets.
This document extends the HTTP CONNECT method, as specified for
HTTP/2 in Section 8.3 of [RFC7540]. The extension allows the
substitution of a new protocol name to connect to rather than the
external host normally used by CONNECT. The result is a tunnel on a
single HTTP/2 stream that can carry data for WebSockets (or any other
protocol). The other streams on the connection may carry more
extended CONNECT tunnels, traditional HTTP/2 data, or a mixture of
both.
McManus Standards Track [Page 2]
RFC 8441 H2 WebSockets September 2018
This tunneled stream will be multiplexed with other regular streams
on the connection and enjoys the normal priority, cancellation, and
flow-control features of HTTP/2.
Streams that successfully establish a WebSocket connection using a
tunneled stream and the modifications to the opening handshake
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