draft-reschke-http-status-308-07.txt   draft-reschke-http-status-308-latest.txt 
Network Working Group J. Reschke Internet Engineering Task Force (IETF) J. Reschke
Internet-Draft greenbytes Request for Comments: 7238 greenbytes
Intended status: Experimental March 26, 2012 Category: Experimental May 2021
Expires: September 27, 2012 ISSN: 2070-1721
The Hypertext Transfer Protocol (HTTP) Status Code 308 (Permanent The Hypertext Transfer Protocol Status Code 308 (Permanent Redirect)
Redirect)
draft-reschke-http-status-308-07
Abstract Abstract
This document specifies the additional HyperText Transfer Protocol This document specifies the additional Hypertext Transfer Protocol
(HTTP) Status Code 308 (Permanent Redirect). (HTTP) status code 308 (Permanent Redirect).
Editorial Note (To be removed by RFC Editor before publication) Editorial Note (To be removed by RFC Editor before publication)
Distribution of this document is unlimited. Although this is not a Distribution of this document is unlimited. Although this is not a
work item of the HTTPbis Working Group, comments should be sent to work item of the HTTPbis Working Group, comments should be sent to
the Hypertext Transfer Protocol (HTTP) mailing list at the Hypertext Transfer Protocol (HTTP) mailing list at ietf-http-
ietf-http-wg@w3.org [1], which may be joined by sending a message wg@w3.org [1], which may be joined by sending a message with subject
with subject "subscribe" to ietf-http-wg-request@w3.org [2]. "subscribe" to ietf-http-wg-request@w3.org [2].
Discussions of the HTTPbis Working Group are archived at Discussions of the HTTPbis Working Group are archived at
<http://lists.w3.org/Archives/Public/ietf-http-wg/>. <http://lists.w3.org/Archives/Public/ietf-http-wg/>.
XML versions, latest edits, and the issues list for this document are XML versions, latest edits, and the issues list for this document are
available from available from <http://greenbytes.de/tech/webdav/#draft-reschke-http-
<http://greenbytes.de/tech/webdav/#draft-reschke-http-status-308>. status-308>.
Test cases related to redirection in general and the status code 308 _This is a temporary document for the purpose of tracking the
in particular can be found at editorial changes made during the AUTH48 (RFC publication) phase._
<http://greenbytes.de/tech/tc/httpredirects/#l-308>.
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This document is not an Internet Standards Track specification; it is
provisions of BCP 78 and BCP 79. published for examination, experimental implementation, and
evaluation.
Internet-Drafts are working documents of the Internet Engineering This document defines an Experimental Protocol for the Internet
Task Force (IETF). Note that other groups may also distribute community. This document is a product of the Internet Engineering
working documents as Internet-Drafts. The list of current Internet- Task Force (IETF). It represents the consensus of the IETF
Drafts is at http://datatracker.ietf.org/drafts/current/. community. It has received public review and has been approved for
publication by the Internet Engineering Steering Group (IESG). Not
all documents approved by the IESG are candidates for any level of
Internet Standard; see Section 2 of RFC 7841.
Internet-Drafts are draft documents valid for a maximum of six months Information about the current status of this document, any errata,
and may be updated, replaced, or obsoleted by other documents at any and how to provide feedback on it may be obtained at
time. It is inappropriate to use Internet-Drafts as reference https://www.rfc-editor.org/info/rfc7238.
material or to cite them other than as "work in progress."
This Internet-Draft will expire on September 27, 2012.
Copyright Notice Copyright Notice
Copyright (c) 2012 IETF Trust and the persons identified as the Copyright (c) 2021 IETF Trust and the persons identified as the
document authors. All rights reserved. document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents Provisions Relating to IETF Documents
(http://trustee.ietf.org/license-info) in effect on the date of (https://trustee.ietf.org/license-info) in effect on the date of
publication of this document. Please review these documents publication of this document. Please review these documents
carefully, as they describe your rights and restrictions with respect carefully, as they describe your rights and restrictions with respect
to this document. Code Components extracted from this document must to this document. Code Components extracted from this document must
include Simplified BSD License text as described in Section 4.e of include Simplified BSD License text as described in Section 4.e of
the Trust Legal Provisions and are provided without warranty as the Trust Legal Provisions and are provided without warranty as
described in the Simplified BSD License. described in the Simplified BSD License.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Notational Conventions . . . . . . . . . . . . . . . . . . . . 3 2. Notational Conventions . . . . . . . . . . . . . . . . . . . 3
3. 308 Permanent Redirect . . . . . . . . . . . . . . . . . . . . 3 3. 308 Permanent Redirect . . . . . . . . . . . . . . . . . . . 3
4. Deployment Considerations . . . . . . . . . . . . . . . . . . . 4 4. Deployment Considerations . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 5 5. Security Considerations . . . . . . . . . . . . . . . . . . . 5
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 5
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
8. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6 8. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
8.1. Normative References . . . . . . . . . . . . . . . . . . . 6 8.1. Normative References . . . . . . . . . . . . . . . . . . 5
8.2. Informative References . . . . . . . . . . . . . . . . . . 6 8.2. Informative References . . . . . . . . . . . . . . . . . 6
Appendix A. Implementations (to be removed by RFC Editor 8.3. URIs . . . . . . . . . . . . . . . . . . . . . . . . . . 6
before publication) . . . . . . . . . . . . . . . . . 7 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 6
Appendix B. Change Log (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . . 7
B.1. Since draft-reschke-http-status-308-00 . . . . . . . . . . 7
B.2. Since draft-reschke-http-status-308-01 . . . . . . . . . . 7
B.3. Since draft-reschke-http-status-308-02 . . . . . . . . . . 7
B.4. Since draft-reschke-http-status-308-03 . . . . . . . . . . 7
B.5. Since draft-reschke-http-status-308-04 . . . . . . . . . . 7
B.6. Since draft-reschke-http-status-308-05 . . . . . . . . . . 8
B.7. Since draft-reschke-http-status-308-06 . . . . . . . . . . 8
Appendix C. Resolved issues (to be removed by RFC Editor
before publication) . . . . . . . . . . . . . . . . . 8
C.1. consistency307 . . . . . . . . . . . . . . . . . . . . . . 8
C.2. sniffing . . . . . . . . . . . . . . . . . . . . . . . . . 8
Appendix D. Open issues (to be removed by RFC Editor prior to
publication) . . . . . . . . . . . . . . . . . . . . . 8
D.1. edit . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
1. Introduction 1. Introduction
HTTP defines a set of status codes for the purpose of redirecting a HTTP defines a set of status codes for the purpose of redirecting a
request to a different URI ([RFC3986]). The history of these status request to a different URI ([RFC3986]). The history of these status
codes is summarized in Section 7.3 of codes is summarized in Section 6.4 of [RFC7231], which also
[draft-ietf-httpbis-p2-semantics], which also classifies the existing classifies the existing status codes into four categories.
status codes into four categories.
The first of these categories contains the status codes 301 (Moved The first of these categories contains the status codes 301 (Moved
Permanently), 302 (Found), and 307 (Temporary Redirect), which can be Permanently), 302 (Found), and 307 (Temporary Redirect), which can be
classified as below: classified as below:
+-------------------------------------------+-----------+-----------+ +-------------------------------------------+-----------+-----------+
| | Permanent | Temporary | | | Permanent | Temporary |
+-------------------------------------------+-----------+-----------+ +-------------------------------------------+-----------+-----------+
| Allows changing the request method from | 301 | 302 | | Allows changing the request method from | 301 | 302 |
| POST to GET | | | | POST to GET | | |
| Does not allow changing the request | - | 307 | | Does not allow changing the request | - | 307 |
| method from POST to GET | | | | method from POST to GET | | |
+-------------------------------------------+-----------+-----------+ +-------------------------------------------+-----------+-----------+
Section 7.3.7 of [draft-ietf-httpbis-p2-semantics] states that HTTP Section 6.4.7 of [RFC7231] states that HTTP does not define a
does not define a permanent variant of status code 307; this permanent variant of status code 307; this specification adds the
specification adds the status code 308, defining this missing variant status code 308, defining this missing variant (Section 3).
(Section 3).
2. Notational Conventions 2. Notational Conventions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in [RFC2119]. document are to be interpreted as described in [RFC2119].
3. 308 Permanent Redirect 3. 308 Permanent Redirect
The target resource has been assigned a new permanent URI and any The 308 (Permanent Redirect) status code indicates that the target
future references to this resource SHOULD use one of the returned resource has been assigned a new permanent URI and any future
URIs. Clients with link editing capabilities ought to automatically references to this resource ought to use one of the enclosed URIs.
re-link references to the effective request URI (Section 5.5 of Clients with link editing capabilities ought to automatically re-link
[draft-ietf-httpbis-p1-messaging]) to one or more of the new references to the effective request URI (Section 5.5 of [RFC7230]) to
references returned by the server, where possible. one or more of the new references sent by the server, where possible.
Caches MAY use a heuristic (see [draft-ietf-httpbis-p6-cache], The server SHOULD generate a Location header field ([RFC7231],
Section 2.3.1.1) to determine freshness for 308 responses. Section 7.1.2) in the response containing a preferred URI reference
for the new permanent URI. The user agent MAY use the Location field
value for automatic redirection. The server's response payload
usually contains a short hypertext note with a hyperlink to the new
URI(s).
The new permanent URI SHOULD be given by the Location field in the A 308 response is cacheable by default; i.e., unless otherwise
response ([draft-ietf-httpbis-p2-semantics], Section 10.5). A indicated by the method definition or explicit cache controls (see
response payload can contain a short hypertext note with a hyperlink [RFC7234], Section 4.2.2).
to the new URI(s).
Note: This status code is similar to 301 Moved Permanently Note: This status code is similar to 301 (Moved Permanently)
(Section 7.3.2 of [draft-ietf-httpbis-p2-semantics]), except that ([RFC7231], Section 6.4.2), except that it does not allow changing
it does not allow rewriting the request method from POST to GET. the request method from POST to GET.
4. Deployment Considerations 4. Deployment Considerations
Section 4 of [draft-ietf-httpbis-p2-semantics] requires recipients to Section 6 of [RFC7231] requires recipients to treat unknown 3xx
treat unknown 3xx status codes the same way as status code 300 status codes the same way as status code 300 Multiple Choices
Multiple Choices ([draft-ietf-httpbis-p2-semantics], Section 7.3.1). ([RFC7231], Section 6.4.1). Thus, servers will not be able to rely
Thus, servers will not be able to rely on automatic redirection on automatic redirection happening similar to status codes 301, 302,
happening similar to status codes 301, 302, or 307. or 307.
Therefore, initial use of status code 308 will be restricted to cases Therefore, initial use of status code 308 will be restricted to cases
where the server has sufficient confidence in the clients where the server has sufficient confidence in the client's
understanding the new code, or when a fallback to the semantics of understanding the new code or when a fallback to the semantics of
status code 300 is not problematic. Server implementers are advised status code 300 is not problematic. Server implementers are advised
not to vary the status code based on characteristics of the request, not to vary the status code based on characteristics of the request,
such as the User-Agent header field ("User-Agent Sniffing") -- doing such as the User-Agent header field ("User-Agent Sniffing") -- doing
so usually results in both hard to maintain and hard to debug code so usually results in code that is both hard to maintain and hard to
and would also require special attention to caching (i.e., setting a debug and would also require special attention to caching (i.e.,
"Vary" response header field, as defined in Section 3.5 of setting a "Vary" response header field, as defined in Section 7.1.4
[draft-ietf-httpbis-p6-cache]). of [RFC7231]).
Note that many existing HTML-based user agents will emulate a refresh Note that many existing HTML-based user agents will emulate a refresh
when encountering an HTML <meta> refresh directive ([HTML]). This when encountering an HTML <meta> refresh directive ([HTML]). This
can be used as another fallback. For example: can be used as another fallback. For example:
Client request: Client request:
GET / HTTP/1.1 GET / HTTP/1.1
Host: example.com Host: example.com
skipping to change at page 5, line 32 skipping to change at page 5, line 8
The document has been moved to The document has been moved to
<a href="http://example.com/new" <a href="http://example.com/new"
>http://example.com/new</a>. >http://example.com/new</a>.
</p> </p>
</body> </body>
</html> </html>
5. Security Considerations 5. Security Considerations
All security considerations that apply to HTTP redirects apply to the All security considerations that apply to HTTP redirects apply to the
308 status code as well (see Section 12 of 308 status code as well (see Section 9 of [RFC7231]).
[draft-ietf-httpbis-p2-semantics]).
6. IANA Considerations 6. IANA Considerations
The registration below shall be added to the HTTP Status Code The registration below has been added to the "Hypertext Transfer
Registry (defined in Section 4.2 of [draft-ietf-httpbis-p2-semantics] Protocol (HTTP) Status Code Registry" (defined in Section 8.2 of
and located at <http://www.iana.org/assignments/http-status-codes>): [RFC7231] and located at <http://www.iana.org/assignments/http-
status-codes>):
+-------+--------------------+---------------------------------+ +-------+--------------------+----------------------------------+
| Value | Description | Reference | | Value | Description | Reference |
+-------+--------------------+---------------------------------+ +-------+--------------------+----------------------------------+
| 308 | Permanent Redirect | Section 3 of this specification | | 308 | Permanent Redirect | Section 3 of this specification |
+-------+--------------------+---------------------------------+ +-------+--------------------+----------------------------------+
7. Acknowledgements 7. Acknowledgements
The definition for the new status code 308 re-uses text from the The definition for the new status code 308 reuses text from the
HTTP/1.1 definitions of status codes 301 and 307. HTTP/1.1 definitions of status codes 301 and 307.
Furthermore, thanks to Ben Campbell, Cyrus Daboo, Eran Hammer-Lahav, Furthermore, thanks to Ben Campbell, Cyrus Daboo, Eran Hammer-Lahav,
Bjoern Hoehrmann, Subramanian Moonesamy, Peter Saint-Andre, and Bjoern Hoehrmann, Subramanian Moonesamy, Peter Saint-Andre, and
Robert Sparks for feedback on this document. Robert Sparks for feedback on this document.
8. References 8. References
8.1. Normative References 8.1. Normative References
[RFC2119] Bradner, S., "Key words for use in [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
RFCs to Indicate Requirement Requirement Levels", BCP 14, RFC 2119,
Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997,
March 1997. <https://www.rfc-editor.org/info/rfc2119>.
[RFC3986] Berners-Lee, T., Fielding, R., and [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
L. Masinter, "Uniform Resource Resource Identifier (URI): Generic Syntax", STD 66,
Identifier (URI): Generic Syntax", RFC 3986, DOI 10.17487/RFC3986, January 2005,
STD 66, RFC 3986, January 2005. <https://www.rfc-editor.org/info/rfc3986>.
[draft-ietf-httpbis-p1-messaging] Fielding, R., Ed., Lafon, Y., Ed., [RFC7230] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
and J. Reschke, Ed., "HTTP/1.1, Protocol (HTTP/1.1): Message Syntax and Routing",
part 1: URIs, Connections, and RFC 7230, DOI 10.17487/RFC7230, June 2014,
Message Parsing", <https://www.rfc-editor.org/info/rfc7230>.
draft-ietf-httpbis-p1-messaging-19
(work in progress), March 2012.
[draft-ietf-httpbis-p2-semantics] Fielding, R., Ed., Lafon, Y., Ed., [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
and J. Reschke, Ed., "HTTP/1.1, Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
part 2: Message Semantics", DOI 10.17487/RFC7231, June 2014,
draft-ietf-httpbis-p2-semantics-19 <https://www.rfc-editor.org/info/rfc7231>.
(work in progress), March 2012.
[draft-ietf-httpbis-p6-cache] Fielding, R., Ed., Lafon, Y., Ed., [RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Nottingham, M., Ed., and J. Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
Reschke, Ed., "HTTP/1.1, part 6: RFC 7234, DOI 10.17487/RFC7234, June 2014,
Caching", <https://www.rfc-editor.org/info/rfc7234>.
draft-ietf-httpbis-p6-cache-19
(work in progress), March 2012.
8.2. Informative References 8.2. Informative References
[HTML] Raggett, D., Le Hors, A., and I. [HTML] Raggett, D., Le Hors, A., and I. Jacobs, "HTML 4.01
Jacobs, "HTML 4.01 Specification", Specification", W3C Recommendation REC-html401-19991224,
W3C Recommendation REC-html401- December 1999,
19991224, December 1999, <http:// <http://www.w3.org/TR/1999/REC-html401-19991224>.
www.w3.org/TR/1999/
REC-html401-19991224>.
Latest version available at
<http://www.w3.org/TR/html401>.
URIs
[1] <mailto:ietf-http-wg@w3.org>
[2] <mailto:ietf-http-wg-request@w3.org?subject=subscribe>
Appendix A. Implementations (to be removed by RFC Editor before
publication)
Chrome: Feature requested in Chromium Issue 109012
(<http://code.google.com/p/chromium/issues/detail?id=109012>).
Curl (the library): no change was needed (test case:
<https://github.com/bagder/curl/blob/master/tests/data/test1325>).
Firefox: now in "nightly" builds, scheduled for release in Firefox 14
(see <https://bugzilla.mozilla.org/show_bug.cgi?id=714302>).
Safari: automatically redirects 3xx status codes when a Location
header field is present, but does not preserve the request method.
Appendix B. Change Log (to be removed by RFC Editor before publication)
B.1. Since draft-reschke-http-status-308-00
Updated HTTPbis reference. Added Appendix A. Added and resolved
issue "refresh".
B.2. Since draft-reschke-http-status-308-01
Added URI spec reference.
B.3. Since draft-reschke-http-status-308-02
Tune HTML example. Expand "Implementations" section. Added and
resolved issue "respformat" (align with new proposed text for 307 in
HTTPbis P2).
B.4. Since draft-reschke-http-status-308-03
Added and resolved issue "uaconfirm".
B.5. Since draft-reschke-http-status-308-04
Added and resolved issue "missingconsiderations". Added request
message to example. Updated the Safari implementation note.
B.6. Since draft-reschke-http-status-308-05
Add informative HTML reference. Update HTTPbis references.
B.7. Since draft-reschke-http-status-308-06
Added and resolved issues "consistency307" and "sniffing". Updated
Firefox implementation status.
Appendix C. Resolved issues (to be removed by RFC Editor before
publication)
Issues that were either rejected or resolved in this version of this
document.
C.1. consistency307
In Section 3:
Type: edit
ben@nostrum.com (2012-03-16): The 307 definition includes an explicit
post about that behavior not being allowed. Section 3 of this doc
does neither.
Resolution: Import (part of the) note from status code 307
description.
C.2. sniffing
In Section 4:
Type: edit
rjsparks@nostrum.com (2012-03-15): Would it be worth adding something
to the draft explicitily discouraging UA sniffing? A reference to
something that already explores why that's not a good idea perhaps?
Resolution: Add advice not to attempt UA sniffing.
Appendix D. Open issues (to be removed by RFC Editor prior to Latest version available at <http://www.w3.org/TR/
publication) html401>.
D.1. edit 8.3. URIs
Type: edit [1] mailto:ietf-http-wg@w3.org
julian.reschke@greenbytes.de (2011-04-15): Umbrella issue for [2] mailto:ietf-http-wg-request@w3.org?subject=subscribe
editorial fixes/enhancements.
Author's Address Author's Address
Julian F. Reschke Julian F. Reschke
greenbytes GmbH greenbytes GmbH
Hafenweg 16 Hafenweg 16
Muenster, NW 48155 Muenster, NW 48155
Germany Germany
EMail: julian.reschke@greenbytes.de EMail: julian.reschke@greenbytes.de
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