HTTP K. Oku
Internet-Draft J. Iyengar
Intended status: Informational Fastly
Expires: 14 February 2022 13 August 2021
Self-Tracing for HTTP
draft-kazuho-httpbis-selftrace-00
Abstract
This document registers a "Well-Known URI" for exposing state of an
HTTP connection to the peer using formats such as qlog schema [QLOG].
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 14 February 2022.
Copyright Notice
Copyright (c) 2021 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.
Oku & Iyengar Expires 14 February 2022 [Page 1]
Internet-Draft Self-Tracing for HTTP August 2021
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Notational Conventions . . . . . . . . . . . . . . . . . 2
2. The Self-Trace Well-Known URI . . . . . . . . . . . . . . . . 2
3. Security Considerations . . . . . . . . . . . . . . . . . . . 3
3.1. Cross-Origin Attacks . . . . . . . . . . . . . . . . . . 3
3.2. Coalescing Proxy Acting as Client . . . . . . . . . . . . 3
3.3. Connections Serving Multiple Origins . . . . . . . . . . 3
4. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
5. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
5.1. Normative References . . . . . . . . . . . . . . . . . . 4
5.2. Informative References . . . . . . . . . . . . . . . . . 4
Appendix A. Acknowledgements . . . . . . . . . . . . . . . . . . 5
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
One challenge regarding HTTP ([HTTP]) performance or stability
analysis is obtaining the sender-side trace of connections. End-
users of HTTP who face issues do not have access to the server-side
traces. It is also difficult for server-side operators to retain
enough amount of fine-grained traces that they can consult when their
end-users report issues. Also, there are privacy concerns regarding
retaining fine-grained traces.
This challenge can be overcome if the server exposes the trace of
each HTTP connection on that same connection. When users experience
issues, they can report to the server operators with the traces that
they obtained on the HTTP connections that suffered. The privacy
concern is mitigated as the users will be submitting the trace
actively.
1.1. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119].
2. The Self-Trace Well-Known URI
When a server receives a GET request at the Self-Trace Well-Known
URI, it starts streaming event information that occur on the
connection on which that request was received.
Note however that, depending on the type of the trace being
collected, sending chunks of a trace might cause additonal events
that in turn generate more chunks that have to be sent. To prevent
Oku & Iyengar Expires 14 February 2022 [Page 2]
Internet-Draft Self-Tracing for HTTP August 2021
this infinite feedback loop, a server SHOULD suspend the transmission
of self-trace when the self-trace becomes the only HTTP request being
inflight on an HTTP connection. When a new HTTP request is opened on
the same HTTP connection, the server can resume the transmission of
the trace.
3. Security Considerations
3.1. Cross-Origin Attacks
To prevent cross-origin attacks, web browser access to the self-trace
MUST be resticted to the same origin [FETCH].
3.2. Coalescing Proxy Acting as Client
When a forward proxy that coalesces HTTP requests from multiple end-
clients connect to an HTTP server that can serve the self-trace, and
if one of the end-clients request the self-trace, the provided trace
might contain information regarding requests bein issued by other
end-clients.
To prevent this attack, servers SHOULD serve self-trace only when
HTTPS is being used. The assumption here is that when HTTPS is being
used, end-clients are directly connected to the server.
3.3. Connections Serving Multiple Origins
Sometimes, reverse proxies are configured as such that one HTTP
connection can be used for serving multiple origins maintained by
different entities (e.g., CDN using an X.509 certificate that
contains multiple customers). In such deployments, a malicious
origin might use a script running on a web browser to fetch the self-
trace that conains traffic information related to other origins
colocated, then upload the fetched trace to extract information.
To prevent such attacks, reverse proxies used for forwarding HTTP
requests to multiple origins belonging to different entities SHOULD
do either of the following:
* Serve self-trace only from an origin maintained by the operator of
the reverse proxy.
* Serve self-trace during only when requests for one origin is
inflight on a given connection.
Oku & Iyengar Expires 14 February 2022 [Page 3]
Internet-Draft Self-Tracing for HTTP August 2021
4. IANA Considerations
This specification registers the following value in the "Well-Known
URIs" registry established by [RFC5785]:
URI suffix: self-trace
Change controller: IETF
Specification document(s): this document
Related information: N/A
5. References
5.1. Normative References
[HTTP] Fielding, R. T., Nottingham, M., and J. Reschke,
"HTTP/1.1", Work in Progress, Internet-Draft, draft-ietf-
httpbis-messaging-17, 25 July 2021,
<https://www.ietf.org/archive/id/draft-ietf-httpbis-
messaging-17.txt>.
[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>.
[RFC5785] Nottingham, M. and E. Hammer-Lahav, "Defining Well-Known
Uniform Resource Identifiers (URIs)", RFC 5785,
DOI 10.17487/RFC5785, April 2010,
<https://www.rfc-editor.org/info/rfc5785>.
5.2. Informative References
[FETCH] WHATWG, "Fetch - Living Standard", n.d.,
<https://fetch.spec.whatwg.org>.
[I-D.benfield-http2-debug-state]
Benfield, C. and B. Fitzpatrick, "HTTP/2 Implementation
Debug State", Work in Progress, Internet-Draft, draft-
benfield-http2-debug-state-01, 10 August 2016,
<https://www.ietf.org/archive/id/draft-benfield-http2-
debug-state-01.txt>.
Oku & Iyengar Expires 14 February 2022 [Page 4]
Internet-Draft Self-Tracing for HTTP August 2021
[QLOG] Marx, R., Niccolini, L., and M. Seemann, "Main logging
schema for qlog", Work in Progress, Internet-Draft, draft-
ietf-quic-qlog-main-schema-00, 10 June 2021,
<https://www.ietf.org/archive/id/draft-ietf-quic-qlog-
main-schema-00.txt>.
Appendix A. Acknowledgements
In [I-D.benfield-http2-debug-state], Cory Benfield presented the idea
of exposing a snapshot of an HTTP connection to the client. The key
difference from that proposal is that this specification defines a
way to "stream" the states as they change.
Authors' Addresses
Kazuho Oku
Fastly
Email: kazuhooku@gmail.com
Jana Iyengar
Fastly
Email: jri.ietf@gmail.com
Oku & Iyengar Expires 14 February 2022 [Page 5]