draft-ietf-httpbis-rfc7238bis-01.txt   draft-ietf-httpbis-rfc7238bis-02.txt 
HTTPbis Working Group J. Reschke HTTPbis Working Group J. Reschke
Internet-Draft greenbytes Internet-Draft greenbytes
Obsoletes: 7238 (if approved) September 16, 2014 Obsoletes: 7238 (if approved) January 14, 2015
Intended status: Standards Track Intended status: Standards Track
Expires: March 20, 2015 Expires: July 18, 2015
The Hypertext Transfer Protocol Status Code 308 (Permanent Redirect) The Hypertext Transfer Protocol Status Code 308 (Permanent Redirect)
draft-ietf-httpbis-rfc7238bis-01 draft-ietf-httpbis-rfc7238bis-02
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).
Status of This Memo Status of This Memo
This Internet-Draft is submitted in full conformance with the This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79. provisions of BCP 78 and BCP 79.
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Internet-Drafts are working documents of the Internet Engineering Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet- working documents as Internet-Drafts. The list of current Internet-
Drafts is at http://datatracker.ietf.org/drafts/current/. Drafts is at http://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
This Internet-Draft will expire on March 20, 2015. This Internet-Draft will expire on July 18, 2015.
Copyright Notice Copyright Notice
Copyright (c) 2014 IETF Trust and the persons identified as the Copyright (c) 2015 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 (http://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
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+-------------------------------------------+-----------+-----------+ +-------------------------------------------+-----------+-----------+
| | 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 6.4.7 of [RFC7231] states that HTTP does not define a Section 6.4.7 of [RFC7231] states that it does not define a permanent
permanent variant of status code 307; this specification adds the variant of status code 307; this specification adds the status code
status code 308, defining this missing variant (Section 3). 308, defining this missing variant (Section 3).
This specification contains no technical changes from the This specification contains no technical changes from the
experimental RFC 7238, which it obsoletes. experimental RFC 7238, which it obsoletes.
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].
skipping to change at page 4, line 21 skipping to change at page 4, line 21
the request method from POST to GET. the request method from POST to GET.
4. Deployment Considerations 4. Deployment Considerations
Section 6 of [RFC7231] requires recipients to treat unknown 3xx Section 6 of [RFC7231] requires recipients to treat unknown 3xx
status codes the same way as status code 300 Multiple Choices status codes the same way as status code 300 Multiple Choices
([RFC7231], Section 6.4.1). Thus, servers will not be able to rely ([RFC7231], Section 6.4.1). Thus, servers will not be able to rely
on automatic redirection happening similar to status codes 301, 302, on automatic redirection happening similar to status codes 301, 302,
or 307. or 307.
Therefore, initial use of status code 308 will be restricted to cases Therefore, the use of status code 308 is restricted to cases where
where the server has sufficient confidence in the client's the server has sufficient confidence in the client's understanding
understanding the new code or when a fallback to the semantics of the new code or when a fallback to the semantics of status code 300
status code 300 is not problematic. Server implementers are advised is not problematic. Server implementers are advised not to vary the
not to vary the status code based on characteristics of the request, status code based on characteristics of the request, such as the
such as the User-Agent header field ("User-Agent Sniffing") -- doing User-Agent header field ("User-Agent Sniffing") -- doing so usually
so usually results in code that is both hard to maintain and hard to results in code that is both hard to maintain and hard to debug and
debug and would also require special attention to caching (i.e., would also require special attention to caching (i.e., setting a
setting a "Vary" response header field, as defined in Section 7.1.4 "Vary" response header field, as defined in Section 7.1.4 of
of [RFC7231]). [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], Section
can be used as another fallback. For example: 4.2.5.3). This 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
Server response: Server response:
HTTP/1.1 308 Permanent Redirect HTTP/1.1 308 Permanent Redirect
Content-Type: text/html; charset=UTF-8 Content-Type: text/html; charset=UTF-8
Location: http://example.com/new Location: http://example.com/new
Content-Length: 454 Content-Length: 356
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" <!DOCTYPE HTML>
"http://www.w3.org/TR/html4/strict.dtd">
<html> <html>
<head> <head>
<title>Permanent Redirect</title> <title>Permanent Redirect</title>
<meta http-equiv="refresh" <meta http-equiv="refresh"
content="0; url=http://example.com/new"> content="0; url=http://example.com/new">
</head> </head>
<body> <body>
<p> <p>
The document has been moved to The document has been moved to
<a href="http://example.com/new" <a href="http://example.com/new"
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| 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 reuses 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, Adrian Farrell,
Bjoern Hoehrmann, Subramanian Moonesamy, Peter Saint-Andre, and Eran Hammer-Lahav, Bjoern Hoehrmann, Barry Leiba, Subramanian
Robert Sparks for feedback on this document. Moonesamy, Peter Saint-Andre, and 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 RFCs to Indicate [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997. Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform [RFC3986] Berners-Lee, T., Fielding, R., and L. Masinter, "Uniform
Resource Identifier (URI): Generic Syntax", STD 66, Resource Identifier (URI): Generic Syntax", STD 66,
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[RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer [RFC7231] Fielding, R., Ed. and J. Reschke, Ed., "Hypertext Transfer
Protocol (HTTP/1.1): Semantics and Content", RFC 7231, Protocol (HTTP/1.1): Semantics and Content", RFC 7231,
June 2014. June 2014.
[RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke, [RFC7234] Fielding, R., Ed., Nottingham, M., Ed., and J. Reschke,
Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching", Ed., "Hypertext Transfer Protocol (HTTP/1.1): Caching",
RFC 7234, June 2014. RFC 7234, June 2014.
8.2. Informative References 8.2. Informative References
[HTML] Raggett, D., Le Hors, A., and I. Jacobs, "HTML 4.01 [HTML] Hickson, I., Berjon, R., Faulkner, S., Leithead, T., Doyle
Specification", W3C Recommendation REC-html401-19991224, Navara, E., O'Connor, E., and S. Pfeiffer, "HTML5", W3C
December 1999, Recommendation REC-html5-20141028, October 2014,
<http://www.w3.org/TR/1999/REC-html401-19991224>. <http://www.w3.org/TR/2014/REC-html5-20141028/>.
Latest version available at Latest version available at <http://www.w3.org/TR/html5/>.
<http://www.w3.org/TR/html401>.
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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