source: draft-ietf-httpbis/latest/p5-range.xml @ 1542

Last change on this file since 1542 was 1542, checked in by ylafon@…, 8 years ago

Explicitly allow servers to combine ranges, mitigate the use of range request to do denial-of-services attacks

  • Property svn:eol-style set to native
  • Property svn:mime-type set to text/xml
File size: 72.8 KB
Line 
1<?xml version="1.0" encoding="utf-8"?>
2<?xml-stylesheet type='text/xsl' href='../myxml2rfc.xslt'?>
3<!DOCTYPE rfc [
4  <!ENTITY MAY "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>MAY</bcp14>">
5  <!ENTITY MUST "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>MUST</bcp14>">
6  <!ENTITY MUST-NOT "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>MUST NOT</bcp14>">
7  <!ENTITY OPTIONAL "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>OPTIONAL</bcp14>">
8  <!ENTITY RECOMMENDED "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>RECOMMENDED</bcp14>">
9  <!ENTITY REQUIRED "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>REQUIRED</bcp14>">
10  <!ENTITY SHALL "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHALL</bcp14>">
11  <!ENTITY SHALL-NOT "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHALL NOT</bcp14>">
12  <!ENTITY SHOULD "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHOULD</bcp14>">
13  <!ENTITY SHOULD-NOT "<bcp14 xmlns='http://purl.org/net/xml2rfc/ext'>SHOULD NOT</bcp14>">
14  <!ENTITY ID-VERSION "latest">
15  <!ENTITY ID-MONTH "February">
16  <!ENTITY ID-YEAR "2012">
17  <!ENTITY architecture               "<xref target='Part1' x:rel='#architecture' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
18  <!ENTITY notation                   "<xref target='Part1' x:rel='#notation' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
19  <!ENTITY abnf-extension             "<xref target='Part1' x:rel='#abnf.extension' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
20  <!ENTITY acks                       "<xref target='Part1' x:rel='#acks' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
21  <!ENTITY whitespace                 "<xref target='Part1' x:rel='#whitespace' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
22  <!ENTITY field-components           "<xref target='Part1' x:rel='#field.components' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
23  <!ENTITY http-date                  "<xref target='Part2' x:rel='#http.date' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
24  <!ENTITY messaging                  "<xref target='Part1' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
25  <!ENTITY entity-tags                "<xref target='Part4' x:rel='#header.etag' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
26  <!ENTITY weak-and-strong-validators "<xref target='Part4' x:rel='#weak.and.strong.validators' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
27  <!ENTITY lastmod-comparison         "<xref target='Part4' x:rel='#lastmod.comparison' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
28  <!ENTITY p6-heuristic               "<xref target='Part6' x:rel='#heuristic.freshness' xmlns:x='http://purl.org/net/xml2rfc/ext'/>">
29]>
30<?rfc toc="yes" ?>
31<?rfc symrefs="yes" ?>
32<?rfc sortrefs="yes" ?>
33<?rfc compact="yes"?>
34<?rfc subcompact="no" ?>
35<?rfc linkmailto="no" ?>
36<?rfc editing="no" ?>
37<?rfc comments="yes"?>
38<?rfc inline="yes"?>
39<?rfc rfcedstyle="yes"?>
40<?rfc-ext allow-markup-in-artwork="yes" ?>
41<?rfc-ext include-references-in-index="yes" ?>
42<rfc obsoletes="2616" category="std" x:maturity-level="proposed"
43     ipr="pre5378Trust200902" docName="draft-ietf-httpbis-p5-range-&ID-VERSION;"
44     xmlns:x='http://purl.org/net/xml2rfc/ext'>
45<x:link rel="prev" basename="p4-conditional"/>
46<x:link rel="next" basename="p6-cache"/>
47<x:feedback template="mailto:ietf-http-wg@w3.org?subject={docname},%20%22{section}%22&amp;body=&lt;{ref}&gt;:"/>
48<front>
49
50  <title abbrev="HTTP/1.1, Part 5">HTTP/1.1, part 5: Range Requests and Partial Responses</title>
51
52  <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
53    <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
54    <address>
55      <postal>
56        <street>345 Park Ave</street>
57        <city>San Jose</city>
58        <region>CA</region>
59        <code>95110</code>
60        <country>USA</country>
61      </postal>
62      <email>fielding@gbiv.com</email>
63      <uri>http://roy.gbiv.com/</uri>
64    </address>
65  </author>
66
67  <author initials="J." surname="Gettys" fullname="Jim Gettys">
68    <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
69    <address>
70      <postal>
71        <street>21 Oak Knoll Road</street>
72        <city>Carlisle</city>
73        <region>MA</region>
74        <code>01741</code>
75        <country>USA</country>
76      </postal>
77      <email>jg@freedesktop.org</email>
78      <uri>http://gettys.wordpress.com/</uri>
79    </address>
80  </author>
81 
82  <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
83    <organization abbrev="HP">Hewlett-Packard Company</organization>
84    <address>
85      <postal>
86        <street>HP Labs, Large Scale Systems Group</street>
87        <street>1501 Page Mill Road, MS 1177</street>
88        <city>Palo Alto</city>
89        <region>CA</region>
90        <code>94304</code>
91        <country>USA</country>
92      </postal>
93      <email>JeffMogul@acm.org</email>
94    </address>
95  </author>
96
97  <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
98    <organization abbrev="Microsoft">Microsoft Corporation</organization>
99    <address>
100      <postal>
101        <street>1 Microsoft Way</street>
102        <city>Redmond</city>
103        <region>WA</region>
104        <code>98052</code>
105        <country>USA</country>
106      </postal>
107      <email>henrikn@microsoft.com</email>
108    </address>
109  </author>
110
111  <author initials="L." surname="Masinter" fullname="Larry Masinter">
112    <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
113    <address>
114      <postal>
115        <street>345 Park Ave</street>
116        <city>San Jose</city>
117        <region>CA</region>
118        <code>95110</code>
119        <country>USA</country>
120      </postal>
121      <email>LMM@acm.org</email>
122      <uri>http://larry.masinter.net/</uri>
123    </address>
124  </author>
125 
126  <author initials="P." surname="Leach" fullname="Paul J. Leach">
127    <organization abbrev="Microsoft">Microsoft Corporation</organization>
128    <address>
129      <postal>
130        <street>1 Microsoft Way</street>
131        <city>Redmond</city>
132        <region>WA</region>
133        <code>98052</code>
134      </postal>
135      <email>paulle@microsoft.com</email>
136    </address>
137  </author>
138   
139  <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
140    <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
141    <address>
142      <postal>
143        <street>MIT Computer Science and Artificial Intelligence Laboratory</street>
144        <street>The Stata Center, Building 32</street>
145        <street>32 Vassar Street</street>
146        <city>Cambridge</city>
147        <region>MA</region>
148        <code>02139</code>
149        <country>USA</country>
150      </postal>
151      <email>timbl@w3.org</email>
152      <uri>http://www.w3.org/People/Berners-Lee/</uri>
153    </address>
154  </author>
155
156  <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
157    <organization abbrev="W3C">World Wide Web Consortium</organization>
158    <address>
159      <postal>
160        <street>W3C / ERCIM</street>
161        <street>2004, rte des Lucioles</street>
162        <city>Sophia-Antipolis</city>
163        <region>AM</region>
164        <code>06902</code>
165        <country>France</country>
166      </postal>
167      <email>ylafon@w3.org</email>
168      <uri>http://www.raubacapeu.net/people/yves/</uri>
169    </address>
170  </author>
171
172  <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
173    <organization abbrev="greenbytes">greenbytes GmbH</organization>
174    <address>
175      <postal>
176        <street>Hafenweg 16</street>
177        <city>Muenster</city><region>NW</region><code>48155</code>
178        <country>Germany</country>
179      </postal>
180      <phone>+49 251 2807760</phone>
181      <facsimile>+49 251 2807761</facsimile>
182      <email>julian.reschke@greenbytes.de</email>
183      <uri>http://greenbytes.de/tech/webdav/</uri>
184    </address>
185  </author>
186
187  <date month="&ID-MONTH;" year="&ID-YEAR;"/>
188  <workgroup>HTTPbis Working Group</workgroup>
189
190<abstract>
191<t>
192   The Hypertext Transfer Protocol (HTTP) is an application-level protocol for
193   distributed, collaborative, hypertext information systems. HTTP has been in
194   use by the World Wide Web global information initiative since 1990. This
195   document is Part 5 of the seven-part specification that defines the protocol
196   referred to as "HTTP/1.1" and, taken together, obsoletes RFC 2616.
197</t>
198<t>
199   Part 5 defines range-specific requests and the rules for constructing and
200   combining responses to those requests.
201</t>
202</abstract>
203
204<note title="Editorial Note (To be removed by RFC Editor)">
205  <t>
206    Discussion of this draft should take place on the HTTPBIS working group
207    mailing list (ietf-http-wg@w3.org), which is archived at
208    <eref target="http://lists.w3.org/Archives/Public/ietf-http-wg/"/>.
209  </t>
210  <t>
211    The current issues list is at
212    <eref target="http://tools.ietf.org/wg/httpbis/trac/report/3"/> and related
213    documents (including fancy diffs) can be found at
214    <eref target="http://tools.ietf.org/wg/httpbis/"/>.
215  </t>
216  <t>
217    The changes in this draft are summarized in <xref target="changes.since.18"/>.
218  </t>
219</note>
220</front>
221<middle>
222<section title="Introduction" anchor="introduction">
223<t>
224   HTTP clients often encounter interrupted data transfers as a result
225   of cancelled requests or dropped connections.  When a client has stored
226   a partial representation, it is desirable to request the remainder
227   of that representation in a subsequent request rather than transfer
228   the entire representation.
229   There are also a number of Web applications that benefit from being
230   able to request only a subset of a larger representation, such as a
231   single page of a very large document or only part of an image to be
232   rendered by a device with limited local storage.
233</t>
234<t>
235   This document defines HTTP/1.1 range requests,
236   partial responses, and the multipart/byteranges media type.
237   The protocol for range requests is an &OPTIONAL; feature of HTTP,
238   designed so resources or recipients that do not implement this feature
239   can respond as if it is a normal GET request without impacting
240   interoperability.  Partial responses are indicated by a distinct status
241   code to not be mistaken for full responses by intermediate caches
242   that might not implement the feature.
243</t>
244<t>
245   Although the HTTP range request mechanism is designed to allow for
246   extensible range types, this specification only defines requests for
247   byte ranges.
248</t>
249
250<section title="Conformance and Error Handling" anchor="intro.conformance.and.error.handling">
251<t>
252   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
253   "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
254   document are to be interpreted as described in <xref target="RFC2119"/>.
255</t>
256<t>
257   This document defines conformance criteria for several roles in HTTP
258   communication, including Senders, Recipients, Clients, Servers, User-Agents,
259   Origin Servers, Intermediaries, Proxies and Gateways. See &architecture;
260   for definitions of these terms.
261</t>
262<t>
263   An implementation is considered conformant if it complies with all of the
264   requirements associated with its role(s). Note that SHOULD-level requirements
265   are relevant here, unless one of the documented exceptions is applicable.
266</t>
267<t>
268   This document also uses ABNF to define valid protocol elements
269   (<xref target="notation"/>). In addition to the prose requirements placed
270   upon them, Senders &MUST-NOT; generate protocol elements that are invalid.
271</t>
272<t>
273   Unless noted otherwise, Recipients &MAY; take steps to recover a usable
274   protocol element from an invalid construct. However, HTTP does not define
275   specific error handling mechanisms, except in cases where it has direct
276   impact on security. This is because different uses of the protocol require
277   different error handling strategies; for example, a Web browser may wish to
278   transparently recover from a response where the Location header field
279   doesn't parse according to the ABNF, whereby in a systems control protocol
280   using HTTP, this type of error recovery could lead to dangerous consequences.
281</t>
282</section>
283
284<section title="Syntax Notation" anchor="notation">
285  <x:anchor-alias value="ALPHA"/>
286  <x:anchor-alias value="CHAR"/>
287  <x:anchor-alias value="CR"/>
288  <x:anchor-alias value="DIGIT"/>
289  <x:anchor-alias value="LF"/>
290  <x:anchor-alias value="OCTET"/>
291  <x:anchor-alias value="SP"/>
292  <x:anchor-alias value="VCHAR"/>
293<t>
294   This specification uses the Augmented Backus-Naur Form (ABNF) notation
295   of <xref target="RFC5234"/> with the list rule extension defined in
296   &notation;<xref target="collected.abnf"/> shows the collected ABNF
297   with the list rule expanded.
298</t>
299<t>
300  The following core rules are included by
301  reference, as defined in <xref target="RFC5234" x:fmt="," x:sec="B.1"/>:
302  ALPHA (letters), CR (carriage return), CRLF (CR LF), CTL (controls),
303  DIGIT (decimal 0-9), DQUOTE (double quote),
304  HEXDIG (hexadecimal 0-9/A-F/a-f), LF (line feed),
305  OCTET (any 8-bit sequence of data), SP (space), and
306  VCHAR (any visible US-ASCII character).
307</t>
308
309<t>
310  Note that all rules derived from <x:ref>token</x:ref> are to
311  be compared case-insensitively, like <x:ref>range-unit</x:ref> and
312  <x:ref>acceptable-ranges</x:ref>.
313</t>
314
315<section title="Core Rules" anchor="core.rules">
316  <x:anchor-alias value="token"/>
317  <x:anchor-alias value="OWS"/>
318  <x:anchor-alias value="HTTP-date"/>
319<t>
320  The core rules below are defined in <xref target="Part1"/> and
321  <xref target="Part2"/>:
322</t>
323<figure><artwork type="abnf2616">
324  <x:ref>OWS</x:ref>        = &lt;OWS, defined in &whitespace;&gt;
325  <x:ref>token</x:ref>      = &lt;token, defined in &field-components;&gt;
326  <x:ref>HTTP-date</x:ref>  = &lt;HTTP-date, defined in &http-date;&gt;
327</artwork></figure>
328</section>
329
330<section title="ABNF Rules defined in other Parts of the Specification" anchor="abnf.dependencies">
331  <x:anchor-alias value="entity-tag"/>
332<t>
333  The ABNF rules below are defined in other parts:
334</t>
335<figure><!--Part4--><artwork type="abnf2616">
336  <x:ref>entity-tag</x:ref> = &lt;entity-tag, defined in &entity-tags;&gt;
337</artwork></figure>
338</section>
339
340</section>
341
342</section>
343
344
345<section title="Range Units" anchor="range.units">
346  <x:anchor-alias value="bytes-unit"/>
347  <x:anchor-alias value="other-range-unit"/>
348  <x:anchor-alias value="range-unit"/>
349<t>
350   HTTP/1.1 allows a client to request that only part (a range) of the
351   representation be included within the response. HTTP/1.1 uses range
352   units in the Range (<xref target="header.range"/>) and Content-Range (<xref target="header.content-range"/>)
353   header fields. A representation can be broken down into subranges according
354   to various structural units.
355</t>
356<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="range-unit"/><iref primary="true" item="Grammar" subitem="bytes-unit"/><iref primary="true" item="Grammar" subitem="other-range-unit"/>
357  <x:ref>range-unit</x:ref>       = <x:ref>bytes-unit</x:ref> / <x:ref>other-range-unit</x:ref>
358  <x:ref>bytes-unit</x:ref>       = "bytes"
359  <x:ref>other-range-unit</x:ref> = <x:ref>token</x:ref>
360</artwork></figure>
361<t>
362  HTTP/1.1 has been designed to allow implementations of applications
363  that do not depend on knowledge of ranges. The only range unit defined
364  by HTTP/1.1 is "bytes". Additional specifiers can be defined as described
365  in <xref target="range.specifier.registry"/>.
366</t>
367<t>
368  If a range unit is not understood in a request, a server &MUST; ignore
369  the whole Range header field (<xref target="header.range"/>).
370  If a range unit is not understood in a response, an intermediary
371  &SHOULD; pass the response to the client; a client &MUST; fail.
372</t>
373
374<section title="Range Specifier Registry" anchor="range.specifier.registry">
375<t>
376   The HTTP Range Specifier Registry defines the name space for the range
377   specifier names.
378</t>
379<t>
380   Registrations &MUST; include the following fields:
381   <list style="symbols">
382     <t>Name</t>
383     <t>Description</t>
384     <t>Pointer to specification text</t>
385   </list>
386</t>
387<t>
388  Values to be added to this name space are subject to IETF review
389  (<xref target="RFC5226" x:fmt="," x:sec="4.1"/>).
390</t>
391<t>
392   The registry itself is maintained at
393   <eref target="http://www.iana.org/assignments/http-range-specifiers"/>.
394</t>
395</section>
396
397</section>
398
399<section title="Status Code Definitions" anchor="status.code.definitions">
400<section title="206 Partial Content" anchor="status.206">
401  <iref primary="true" item="206 Partial Content (status code)" x:for-anchor=""/>
402  <iref primary="true" item="Status Codes" subitem="206 Partial Content" x:for-anchor=""/>
403<t>
404   The server has fulfilled the partial GET request for the resource.
405   The request &MUST; have included a Range header field (<xref target="header.range"/>)
406   indicating the desired range, and &MAY; have included an If-Range
407   header field (<xref target="header.if-range"/>) to make the request conditional.
408</t>
409<t>
410   The response &MUST; include the following header fields:
411  <list style="symbols">
412    <t>
413        Either a Content-Range header field (<xref target="header.content-range"/>) indicating
414        the range included with this response, or a multipart/byteranges
415        Content-Type including Content-Range fields for each part. If a
416        Content-Length header field is present in the response, its
417        value &MUST; match the actual number of octets transmitted in the
418        message-body.
419    </t>
420    <t>
421        Date
422    </t>
423    <t>
424        Cache-Control, ETag, Expires, Content-Location, Last-Modified,
425        and/or Vary, if the header field would have been sent in a 200
426        response to the same request
427    </t>
428  </list>
429</t>
430<t>
431   If the 206 response is the result of an If-Range request, the response
432   &SHOULD-NOT; include other representation header fields. Otherwise, the response
433   &MUST; include all of the representation header fields that would have been returned
434   with a 200 (OK) response to the same request.
435</t>
436<t>
437   Caches &MAY; use a heuristic (see &p6-heuristic;) to determine
438   freshness for 206 responses.
439</t>
440</section>
441
442<section title="416 Requested Range Not Satisfiable" anchor="status.416">
443  <iref primary="true" item="416 Requested Range Not Satisfiable (status code)" x:for-anchor=""/>
444  <iref primary="true" item="Status Codes" subitem="416 Requested Range Not Satisfiable" x:for-anchor=""/>
445<t>
446   A server &SHOULD; return a response with this status code if a request
447   included a Range header field (<xref target="header.range"/>), and none of
448   the ranges-specifier values in this field overlap the current extent
449   of the selected resource, and the request did not include an If-Range
450   header field (<xref target="header.if-range"/>). (For byte-ranges,
451   this means that the first-byte-pos of all of the byte-range-spec values were
452   greater than the current length of the selected resource.)
453</t>
454<t>
455   When this status code is returned for a byte-range request, the
456   response &SHOULD; include a Content-Range header field
457   specifying the current length of the representation (see <xref target="header.content-range"/>).
458   This response &MUST-NOT; use the multipart/byteranges content-type. For example,
459</t>
460<figure><artwork type="example">
461  HTTP/1.1 416 Requested Range Not Satisfiable
462  Date: Mon, 20 Jan 2012 15:41:54 GMT
463  Content-Range: bytes */47022
464  Content-Type: image/gif
465</artwork></figure>
466<x:note>
467  <t>
468    <x:h>Note:</x:h> Clients cannot depend on servers to send a 416 (Requested
469    range not satisfiable) response instead of a 200 (OK) response for
470    an unsatisfiable Range header field, since not all servers
471    implement this header field.
472  </t>
473</x:note>
474</section>
475</section>
476
477<section title="Responses to a Range Request">
478<section title="Response to a Single and Multiple Ranges Request">
479<t>
480   When an HTTP message includes the content of a single range (for
481   example, a response to a request for a single range, or to a request
482   for a set of ranges that overlap without any holes), this content is
483   transmitted with a Content-Range header field, and a Content-Length header
484   field showing the number of bytes actually transferred. For example,
485</t>
486<figure><artwork type="example">
487  HTTP/1.1 206 Partial Content
488  Date: Wed, 15 Nov 1995 06:25:24 GMT
489  Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
490  Content-Range: bytes 21010-47021/47022
491  Content-Length: 26012
492  Content-Type: image/gif
493</artwork></figure>
494<t>
495   When an HTTP message includes the content of multiple ranges (for
496   example, a response to a request for multiple non-overlapping
497   ranges), these are transmitted as a multipart message. The multipart
498   media type used for this purpose is "multipart/byteranges" as defined
499   in <xref target="internet.media.type.multipart.byteranges"/>.
500</t>
501<t>
502   A server &MAY; combine requested ranges when those ranges are overlapping
503   (See <xref target="security.considerations"/>).
504</t>
505<t>
506   A response to a request for a single range &MUST-NOT; be sent using the
507   multipart/byteranges media type.  A response to a request for
508   multiple ranges, whose result is a single range, &MAY; be sent as a
509   multipart/byteranges media type with one part. A client that cannot
510   decode a multipart/byteranges message &MUST-NOT; ask for multiple
511   ranges in a single request.
512</t>
513<t>
514   When a client requests multiple ranges in one request, the
515   server &SHOULD; return them in the order that they appeared in the
516   request.
517</t>
518</section>
519
520<section title="Combining Ranges" anchor="combining.byte.ranges">
521<t>
522   A response might transfer only a subrange of a representation if the
523   connection closed prematurely or if the request used one or more Range
524   specifications.  After several such transfers, a client might have
525   received several ranges of the same representation.  These ranges can only
526   be safely combined if they all have in common the same strong validator,
527   where "strong validator" is defined to be either an entity-tag that is
528   not marked as weak (&entity-tags;) or, if no entity-tag is provided, a
529   Last-Modified value that is strong in the sense defined by
530   &lastmod-comparison;.
531</t>
532<t>
533   When a client receives an incomplete 200 (OK) or 206 (Partial Content)
534   response and already has one or more stored responses for the same method
535   and effective request URI, all of the stored responses with the same
536   strong validator &MAY; be combined with the partial content in this new
537   response.  If none of the stored responses contain the same strong
538   validator, then this new response corresponds to a new representation
539   and &MUST-NOT; be combined with the existing stored responses.
540</t>
541<t>
542   If the new response is an incomplete 200 (OK) response, then the header
543   fields of that new response are used for any combined response and replace
544   those of the matching stored responses.
545</t>
546<t>
547   If the new response is a 206 (Partial Content) response and at least one
548   of the matching stored responses is a 200 (OK), then the combined response
549   header fields consist of the most recent 200 response's header fields.
550   If all of the matching stored responses are 206 responses, then the
551   stored response with the most header fields is used as the source of
552   header fields for the combined response, except that the client &MUST;
553   use other header fields provided in the new response, aside from
554   Content-Range, to replace all instances of the corresponding header
555   fields in the stored response.
556</t>
557<t>
558   The combined response message-body consists of the union of partial
559   content ranges in the new response and each of the selected responses.
560   If the union consists of the entire range of the representation, then the
561   combined response &MUST; be recorded as a complete 200 (OK) response
562   with a Content-Length header field that reflects the complete length.
563   Otherwise, the combined response(s) &MUST; include a Content-Range
564   header field describing the included range(s) and be recorded as
565   incomplete.  If the union consists of a discontinuous range of the
566   representation, then the client &MAY; store it as either a multipart range
567   response or as multiple 206 responses with one continuous range each.
568</t>
569</section>
570</section>
571
572<section title="Header Field Definitions" anchor="header.field.definitions">
573<t>
574   This section defines the syntax and semantics of HTTP/1.1 header fields
575   related to range requests and partial responses.
576</t>
577
578<section title="Accept-Ranges" anchor="header.accept-ranges">
579  <iref primary="true" item="Accept-Ranges header field" x:for-anchor=""/>
580  <iref primary="true" item="Header Fields" subitem="Accept-Ranges" x:for-anchor=""/>
581  <x:anchor-alias value="Accept-Ranges"/>
582  <x:anchor-alias value="acceptable-ranges"/>
583<t>
584   The "Accept-Ranges" header field allows a resource to indicate
585   its acceptance of range requests.
586</t>
587<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Accept-Ranges"/><iref primary="true" item="Grammar" subitem="acceptable-ranges"/>
588  <x:ref>Accept-Ranges</x:ref>     = <x:ref>acceptable-ranges</x:ref>
589  <x:ref>acceptable-ranges</x:ref> = 1#<x:ref>range-unit</x:ref> / "none"
590</artwork></figure>
591<t>
592      Origin servers that accept byte-range requests &MAY; send
593</t>
594<figure><artwork type="example">
595  Accept-Ranges: bytes
596</artwork></figure>
597<t>
598      but are not required to do so. Clients &MAY; generate range
599      requests without having received this header field for the resource
600      involved. Range units are defined in <xref target="range.units"/>.
601</t>
602<t>
603      Servers that do not accept any kind of range request for a
604      resource &MAY; send
605</t>
606<figure><artwork type="example">
607  Accept-Ranges: none
608</artwork></figure>
609<t>
610      to advise the client not to attempt a range request.
611</t>
612</section>
613
614<section title="Content-Range" anchor="header.content-range">
615  <iref primary="true" item="Content-Range header field" x:for-anchor=""/>
616  <iref primary="true" item="Header Fields" subitem="Content-Range" x:for-anchor=""/>
617  <x:anchor-alias value="byte-content-range-spec"/>
618  <x:anchor-alias value="byte-range-resp-spec"/>
619  <x:anchor-alias value="Content-Range"/>
620  <x:anchor-alias value="instance-length"/>
621  <x:anchor-alias value="other-content-range-spec"/>
622  <x:anchor-alias value="other-range-resp-spec"/>
623<t>
624   The "Content-Range" header field is sent with a partial representation to
625   specify where in the full representation the payload body is intended to be
626   applied.
627</t>
628<t>   
629   Range units are defined in <xref target="range.units"/>.
630</t>
631<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Content-Range"/><iref primary="true" item="Grammar" subitem="byte-content-range-spec"/><iref primary="true" item="Grammar" subitem="byte-range-resp-spec"/><iref primary="true" item="Grammar" subitem="instance-length"/>
632  <x:ref>Content-Range</x:ref>           = <x:ref>byte-content-range-spec</x:ref>
633                          / <x:ref>other-content-range-spec</x:ref>
634                         
635  <x:ref>byte-content-range-spec</x:ref> = <x:ref>bytes-unit</x:ref> <x:ref>SP</x:ref>
636                            <x:ref>byte-range-resp-spec</x:ref> "/"
637                            ( <x:ref>instance-length</x:ref> / "*" )
638 
639  <x:ref>byte-range-resp-spec</x:ref>    = (<x:ref>first-byte-pos</x:ref> "-" <x:ref>last-byte-pos</x:ref>)
640                          / "*"
641                         
642  <x:ref>instance-length</x:ref>         = 1*<x:ref>DIGIT</x:ref>
643 
644  <x:ref>other-content-range-spec</x:ref> = <x:ref>other-range-unit</x:ref> <x:ref>SP</x:ref>
645                             <x:ref>other-range-resp-spec</x:ref>
646  <x:ref>other-range-resp-spec</x:ref>    = *<x:ref>CHAR</x:ref>
647</artwork></figure>
648<t>
649   The header field &SHOULD; indicate the total length of the full representation,
650   unless this length is unknown or difficult to determine. The asterisk
651   "*" character means that the instance-length is unknown at the time
652   when the response was generated.
653</t>
654<t>
655   Unlike byte-ranges-specifier values (see <xref target="byte.ranges"/>), a byte-range-resp-spec
656   &MUST; only specify one range, and &MUST; contain
657   absolute byte positions for both the first and last byte of the
658   range.
659</t>
660<t>
661   A byte-content-range-spec with a byte-range-resp-spec whose last-byte-pos
662   value is less than its first-byte-pos value, or whose
663   instance-length value is less than or equal to its last-byte-pos
664   value, is invalid. The recipient of an invalid byte-content-range-spec
665   &MUST; ignore it and any content transferred along with it.
666</t>
667<t>
668   In the case of a byte range request:
669   A server sending a response with status code 416 (Requested range not
670   satisfiable) &SHOULD; include a Content-Range field with a byte-range-resp-spec
671   of "*". The instance-length specifies the current length of
672   the selected resource. A response with status code 206 (Partial
673   Content) &MUST-NOT; include a Content-Range field with a byte-range-resp-spec of "*".
674</t>
675<t>
676  The "Content-Range" header field has no meaning for status codes that do not
677  explicitly describe its semantic. Currently, only status codes
678  206 (Partial Content) and 416 (Requested range not satisfiable) describe
679  the meaning of this header field.
680</t>
681<t>
682   Examples of byte-content-range-spec values, assuming that the representation
683   contains a total of 1234 bytes:
684   <list style="symbols">
685      <t>
686        The first 500 bytes:
687<figure><artwork type="example" x:indent-with="   ">
688  bytes 0-499/1234
689</artwork></figure>
690      </t>   
691      <t>
692        The second 500 bytes:
693<figure><artwork type="example" x:indent-with="   ">
694  bytes 500-999/1234
695</artwork></figure>
696      </t>   
697      <t>
698        All except for the first 500 bytes:
699<figure><artwork type="example" x:indent-with="   ">
700  bytes 500-1233/1234
701</artwork></figure>
702      </t>   
703      <t>
704        The last 500 bytes:
705<figure><artwork type="example" x:indent-with="   ">
706  bytes 734-1233/1234
707</artwork></figure>
708      </t>   
709   </list>
710</t>
711<t>
712   If the server ignores a byte-range-spec (for example if it is
713   syntactically invalid, or if it may be seen as a denial-of-service
714   attack), the server &SHOULD; treat the request as if the invalid Range
715   header field did not exist. (Normally, this means return a 200
716   response containing the full representation).
717</t>
718</section>
719
720<section title="If-Range" anchor="header.if-range">
721  <iref primary="true" item="If-Range header field" x:for-anchor=""/>
722  <iref primary="true" item="Header Fields" subitem="If-Range" x:for-anchor=""/>
723  <x:anchor-alias value="If-Range"/>
724<t>
725   If a client has a partial copy of a representation and wishes
726   to have an up-to-date copy of the entire representation, it
727   could use the Range header field with a conditional GET (using
728   either or both of If-Unmodified-Since and If-Match.) However, if the
729   condition fails because the representation has been modified, the client
730   would then have to make a second request to obtain the entire current
731   representation.
732</t>
733<t>
734   The "If-Range" header field allows a client to "short-circuit" the second
735   request. Informally, its meaning is "if the representation is unchanged, send
736   me the part(s) that I am missing; otherwise, send me the entire new
737   representation".
738</t>
739<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="If-Range"/>
740  <x:ref>If-Range</x:ref> = <x:ref>entity-tag</x:ref> / <x:ref>HTTP-date</x:ref>
741</artwork></figure>
742<t>
743   Clients &MUST-NOT; use an entity-tag marked as weak in an If-Range
744   field value and &MUST-NOT; use a Last-Modified date in an If-Range
745   field value unless it has no entity-tag for the representation and
746   the Last-Modified date it does have for the representation is strong
747   in the sense defined by &lastmod-comparison;.
748</t>
749<t>
750   A server that evaluates a conditional range request that is applicable
751   to one of its representations &MUST; evaluate the condition as false if
752   the entity-tag used as a validator is marked as weak or, when an HTTP-date
753   is used as the validator, if the date value is not strong in the sense
754   defined by &lastmod-comparison;. (A server can distinguish between a
755   valid HTTP-date and any form of entity-tag by examining the first
756   two characters.)
757</t>
758<t>
759   The If-Range header field &SHOULD; only be sent by clients together with
760   a Range header field.  The If-Range header field &MUST; be ignored if it
761   is received in a request that does not include a Range header field.
762   The If-Range header field &MUST; be ignored by a server that does not
763   support the sub-range operation.
764</t>
765<t>
766   If the validator given in the If-Range header field matches the current
767   validator for the selected representation of the target resource, then
768   the server &SHOULD; send the specified sub-range of the representation
769   using a 206 (Partial Content) response. If the validator does not match,
770   then the server &SHOULD; send the entire representation using a 200 (OK)
771   response.
772</t>
773</section>
774
775<section title="Range" anchor="header.range">
776  <iref primary="true" item="Range header field" x:for-anchor=""/>
777  <iref primary="true" item="Header Fields" subitem="Range" x:for-anchor=""/>
778
779<section title="Byte Ranges" anchor="byte.ranges">
780<t>
781   Since all HTTP representations are transferred as sequences
782   of bytes, the concept of a byte range is meaningful for any HTTP
783   representation. (However, not all clients and servers need to support byte-range
784   operations.)
785</t>
786<t>
787   Byte range specifications in HTTP apply to the sequence of bytes in
788   the representation body (not necessarily the same as the message-body).
789</t>
790<t anchor="rule.ranges-specifier">
791  <x:anchor-alias value="byte-range-set"/>
792  <x:anchor-alias value="byte-range-spec"/>
793  <x:anchor-alias value="byte-ranges-specifier"/>
794  <x:anchor-alias value="first-byte-pos"/>
795  <x:anchor-alias value="last-byte-pos"/>
796  <x:anchor-alias value="ranges-specifier"/>
797  <x:anchor-alias value="suffix-byte-range-spec"/>
798  <x:anchor-alias value="suffix-length"/>
799
800   A byte range operation &MAY; specify a single range of bytes, or a set
801   of ranges within a single representation.
802</t>
803<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="ranges-specifier"/><iref primary="true" item="Grammar" subitem="byte-ranges-specifier"/><iref primary="true" item="Grammar" subitem="byte-range-set"/><iref primary="true" item="Grammar" subitem="byte-range-spec"/><iref primary="true" item="Grammar" subitem="first-byte-pos"/><iref primary="true" item="Grammar" subitem="last-byte-pos"/>
804  <x:ref>byte-ranges-specifier</x:ref> = <x:ref>bytes-unit</x:ref> "=" <x:ref>byte-range-set</x:ref>
805  <x:ref>byte-range-set</x:ref>  = 1#( <x:ref>byte-range-spec</x:ref> / <x:ref>suffix-byte-range-spec</x:ref> )
806  <x:ref>byte-range-spec</x:ref> = <x:ref>first-byte-pos</x:ref> "-" [ <x:ref>last-byte-pos</x:ref> ]
807  <x:ref>first-byte-pos</x:ref>  = 1*<x:ref>DIGIT</x:ref>
808  <x:ref>last-byte-pos</x:ref>   = 1*<x:ref>DIGIT</x:ref>
809</artwork></figure>
810<t>
811   The first-byte-pos value in a byte-range-spec gives the byte-offset
812   of the first byte in a range. The last-byte-pos value gives the
813   byte-offset of the last byte in the range; that is, the byte
814   positions specified are inclusive. Byte offsets start at zero.
815</t>
816<t>
817   If the last-byte-pos value is present, it &MUST; be greater than or
818   equal to the first-byte-pos in that byte-range-spec, or the byte-range-spec
819   is syntactically invalid. The recipient of a byte-range-set
820   that includes one or more syntactically invalid byte-range-spec
821   values &MUST; ignore the header field that includes that byte-range-set.
822</t>
823<t>
824   If the last-byte-pos value is absent, or if the value is greater than
825   or equal to the current length of the representation body, last-byte-pos is
826   taken to be equal to one less than the current length of the representation
827   in bytes.
828</t>
829<t>
830   By its choice of last-byte-pos, a client can limit the number of
831   bytes retrieved without knowing the size of the representation.
832</t>
833<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="suffix-byte-range-spec"/><iref primary="true" item="Grammar" subitem="suffix-length"/>
834  <x:ref>suffix-byte-range-spec</x:ref> = "-" <x:ref>suffix-length</x:ref>
835  <x:ref>suffix-length</x:ref> = 1*<x:ref>DIGIT</x:ref>
836</artwork></figure>
837<t>
838   A suffix-byte-range-spec is used to specify the suffix of the
839   representation body, of a length given by the suffix-length value. (That is,
840   this form specifies the last N bytes of a representation.) If the
841   representation is shorter than the specified suffix-length, the entire
842   representation is used.
843</t>
844<t>
845   If a syntactically valid byte-range-set includes at least one byte-range-spec
846   whose first-byte-pos is less than the current length of
847   the representation, or at least one suffix-byte-range-spec with a non-zero
848   suffix-length, then the byte-range-set is satisfiable.
849   Otherwise, the byte-range-set is unsatisfiable. If the byte-range-set
850   is unsatisfiable, the server &SHOULD; return a response with a
851   416 (Requested range not satisfiable) status code. Otherwise, the server
852   &SHOULD; return a response with a 206 (Partial Content) status code
853   containing the satisfiable ranges of the representation.
854</t>
855<t>
856   Examples of byte-ranges-specifier values (assuming a representation of
857   length 10000):
858  <list style="symbols">
859     <t>The first 500 bytes (byte offsets 0-499, inclusive):
860<figure><artwork type="example" x:indent-with="   ">
861  bytes=0-499
862</artwork></figure>
863    </t>
864     <t>The second 500 bytes (byte offsets 500-999, inclusive):
865<figure><artwork type="example" x:indent-with="   ">
866  bytes=500-999
867</artwork></figure>
868    </t>
869     <t>The final 500 bytes (byte offsets 9500-9999, inclusive):
870<figure><artwork type="example" x:indent-with="   ">
871  bytes=-500
872</artwork></figure>
873    Or:
874<figure><artwork type="example" x:indent-with="   ">
875  bytes=9500-
876</artwork></figure>
877    </t>
878     <t>The first and last bytes only (bytes 0 and 9999):
879<figure><artwork type="example" x:indent-with="   ">
880  bytes=0-0,-1
881</artwork></figure>
882     </t>
883     <t>Several legal but not canonical specifications of the second 500
884        bytes (byte offsets 500-999, inclusive):
885<figure><artwork type="example" x:indent-with="   ">
886  bytes=500-600,601-999
887  bytes=500-700,601-999
888</artwork></figure>
889     </t>
890  </list>
891</t>
892</section>
893
894<section title="Range Retrieval Requests" anchor="range.retrieval.requests">
895  <x:anchor-alias value="Range"/>
896  <x:anchor-alias value="other-ranges-specifier"/>
897  <x:anchor-alias value="other-range-set"/>
898<t>
899   The "Range" header field defines the GET method (conditional or
900   not) to request one or more sub-ranges of the response representation body, instead
901   of the entire representation body.
902</t>
903<figure><artwork type="abnf2616"><iref primary="true" item="Grammar" subitem="Range"/>
904  <x:ref>Range</x:ref> = <x:ref>byte-ranges-specifier</x:ref> / <x:ref>other-ranges-specifier</x:ref>
905  <x:ref>other-ranges-specifier</x:ref> = <x:ref>other-range-unit</x:ref> "=" <x:ref>other-range-set</x:ref>
906  <x:ref>other-range-set</x:ref> = 1*<x:ref>CHAR</x:ref>
907</artwork></figure>
908<t>
909   A server &MAY; ignore the Range header field. However, origin
910   servers and intermediate caches ought to support byte ranges when
911   possible, since Range supports efficient recovery from partially
912   failed transfers, and supports efficient partial retrieval of large
913   representations.
914</t>
915<t>
916   If the server supports the Range header field and the specified range or
917   ranges are appropriate for the representation:
918  <list style="symbols">
919     <t>The presence of a Range header field in an unconditional GET modifies
920        what is returned if the GET is otherwise successful. In other
921        words, the response carries a status code of 206 (Partial
922        Content) instead of 200 (OK).</t>
923
924     <t>The presence of a Range header field in a conditional GET (a request
925        using one or both of If-Modified-Since and If-None-Match, or
926        one or both of If-Unmodified-Since and If-Match) modifies what
927        is returned if the GET is otherwise successful and the
928        condition is true. It does not affect the 304 (Not Modified)
929        response returned if the conditional is false.</t>
930  </list>
931</t>
932<t>
933   In some cases, it might be more appropriate to use the If-Range
934   header field (see <xref target="header.if-range"/>) in addition to the Range
935   header field.
936</t>
937<t>
938   If a proxy that supports ranges receives a Range request, forwards
939   the request to an inbound server, and receives an entire representation in
940   reply, it &MAY; only return the requested range to its client.
941</t>
942</section>
943</section>
944</section>
945
946<section title="IANA Considerations" anchor="IANA.considerations">
947
948<section title="Status Code Registration" anchor="status.code.registration">
949<t>
950   The HTTP Status Code Registry located at <eref target="http://www.iana.org/assignments/http-status-codes"/>
951   shall be updated with the registrations below:
952</t>
953<?BEGININC p5-range.iana-status-codes ?>
954<!--AUTOGENERATED FROM extract-status-code-defs.xslt, do not edit manually-->
955<texttable align="left" suppress-title="true" anchor="iana.status.code.registration.table">
956   <ttcol>Value</ttcol>
957   <ttcol>Description</ttcol>
958   <ttcol>Reference</ttcol>
959   <c>206</c>
960   <c>Partial Content</c>
961   <c>
962      <xref target="status.206"/>
963   </c>
964   <c>416</c>
965   <c>Requested Range Not Satisfiable</c>
966   <c>
967      <xref target="status.416"/>
968   </c>
969</texttable>
970<!--(END)-->
971<?ENDINC p5-range.iana-status-codes ?>
972</section>
973
974<section title="Header Field Registration" anchor="header.field.registration">
975<t>
976   The Message Header Field Registry located at <eref target="http://www.iana.org/assignments/message-headers/message-header-index.html"/> shall be updated
977   with the permanent registrations below (see <xref target="RFC3864"/>):
978</t>
979<?BEGININC p5-range.iana-headers ?>
980<!--AUTOGENERATED FROM extract-header-defs.xslt, do not edit manually-->
981<texttable align="left" suppress-title="true" anchor="iana.header.registration.table">
982   <ttcol>Header Field Name</ttcol>
983   <ttcol>Protocol</ttcol>
984   <ttcol>Status</ttcol>
985   <ttcol>Reference</ttcol>
986
987   <c>Accept-Ranges</c>
988   <c>http</c>
989   <c>standard</c>
990   <c>
991      <xref target="header.accept-ranges"/>
992   </c>
993   <c>Content-Range</c>
994   <c>http</c>
995   <c>standard</c>
996   <c>
997      <xref target="header.content-range"/>
998   </c>
999   <c>If-Range</c>
1000   <c>http</c>
1001   <c>standard</c>
1002   <c>
1003      <xref target="header.if-range"/>
1004   </c>
1005   <c>Range</c>
1006   <c>http</c>
1007   <c>standard</c>
1008   <c>
1009      <xref target="header.range"/>
1010   </c>
1011</texttable>
1012<!--(END)-->
1013<?ENDINC p5-range.iana-headers ?>
1014<t>
1015   The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
1016</t>
1017</section>
1018
1019<section title="Range Specifier Registration" anchor="range.specifier.registration">
1020<t>
1021  The registration procedure for HTTP Range Specifiers is defined by
1022  <xref target="range.specifier.registry"/> of this document.
1023</t>
1024<t>
1025   The HTTP Range Specifier Registry shall be created at <eref target="http://www.iana.org/assignments/http-range-specifiers"/>
1026   and be populated with the registrations below:
1027</t>
1028<texttable align="left" suppress-title="true" anchor="iana.range.specifiers.table">
1029   <ttcol>Range Specifier Name</ttcol>
1030   <ttcol>Description</ttcol>
1031   <ttcol>Reference</ttcol>
1032
1033   <c>bytes</c>
1034   <c>a range of octets</c>
1035   <c>(this specification)</c>
1036</texttable>
1037<t>
1038   The change controller is: "IETF (iesg@ietf.org) - Internet Engineering Task Force".
1039</t>
1040</section>
1041</section>
1042
1043<section title="Security Considerations" anchor="security.considerations">
1044<t>
1045   This section is meant to inform application developers, information
1046   providers, and users of the security limitations in HTTP/1.1 as
1047   described by this document. The discussion does not include
1048   definitive solutions to the problems revealed, though it does make
1049   some suggestions for reducing security risks.
1050</t>
1051<section title="Overlapping Ranges" anchor="overlapping.ranges">
1052<t>
1053   Range requests containing overlapping ranges may lead to the situation
1054   where a server is sending far more data than the size of the complete
1055   resource representation.
1056</t>
1057</section>
1058</section>
1059
1060<section title="Acknowledgments" anchor="acks">
1061<t>
1062  See &acks;.
1063</t>
1064</section>
1065</middle>
1066<back>
1067
1068<references title="Normative References">
1069
1070<reference anchor="Part1">
1071  <front>
1072    <title abbrev="HTTP/1.1">HTTP/1.1, part 1: URIs, Connections, and Message Parsing</title>
1073    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
1074      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1075      <address><email>fielding@gbiv.com</email></address>
1076    </author>
1077    <author initials="J." surname="Gettys" fullname="Jim Gettys">
1078      <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
1079      <address><email>jg@freedesktop.org</email></address>
1080    </author>
1081    <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
1082      <organization abbrev="HP">Hewlett-Packard Company</organization>
1083      <address><email>JeffMogul@acm.org</email></address>
1084    </author>
1085    <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
1086      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1087      <address><email>henrikn@microsoft.com</email></address>
1088    </author>
1089    <author initials="L." surname="Masinter" fullname="Larry Masinter">
1090      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1091      <address><email>LMM@acm.org</email></address>
1092    </author>
1093    <author initials="P." surname="Leach" fullname="Paul J. Leach">
1094      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1095      <address><email>paulle@microsoft.com</email></address>
1096    </author>
1097    <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
1098      <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1099      <address><email>timbl@w3.org</email></address>
1100    </author>
1101    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
1102      <organization abbrev="W3C">World Wide Web Consortium</organization>
1103      <address><email>ylafon@w3.org</email></address>
1104    </author>
1105    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
1106      <organization abbrev="greenbytes">greenbytes GmbH</organization>
1107      <address><email>julian.reschke@greenbytes.de</email></address>
1108    </author>
1109    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
1110  </front>
1111  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p1-messaging-&ID-VERSION;"/>
1112  <x:source href="p1-messaging.xml" basename="p1-messaging"/>
1113</reference>
1114
1115<reference anchor="Part2">
1116  <front>
1117    <title abbrev="HTTP/1.1">HTTP/1.1, part 2: Message Semantics</title>
1118    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
1119      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1120      <address><email>fielding@gbiv.com</email></address>
1121    </author>
1122    <author initials="J." surname="Gettys" fullname="Jim Gettys">
1123      <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
1124      <address><email>jg@freedesktop.org</email></address>
1125    </author>
1126    <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
1127      <organization abbrev="HP">Hewlett-Packard Company</organization>
1128      <address><email>JeffMogul@acm.org</email></address>
1129    </author>
1130    <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
1131      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1132      <address><email>henrikn@microsoft.com</email></address>
1133    </author>
1134    <author initials="L." surname="Masinter" fullname="Larry Masinter">
1135      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1136      <address><email>LMM@acm.org</email></address>
1137    </author>
1138    <author initials="P." surname="Leach" fullname="Paul J. Leach">
1139      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1140      <address><email>paulle@microsoft.com</email></address>
1141    </author>
1142    <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
1143      <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1144      <address><email>timbl@w3.org</email></address>
1145    </author>
1146    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
1147      <organization abbrev="W3C">World Wide Web Consortium</organization>
1148      <address><email>ylafon@w3.org</email></address>
1149    </author>
1150    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
1151      <organization abbrev="greenbytes">greenbytes GmbH</organization>
1152      <address><email>julian.reschke@greenbytes.de</email></address>
1153    </author>
1154    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
1155  </front>
1156  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p2-semantics-&ID-VERSION;"/>
1157  <x:source href="p2-semantics.xml" basename="p2-semantics"/>
1158</reference>
1159
1160<reference anchor="Part4">
1161  <front>
1162    <title abbrev="HTTP/1.1">HTTP/1.1, part 4: Conditional Requests</title>
1163    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
1164      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1165      <address><email>fielding@gbiv.com</email></address>
1166    </author>
1167    <author initials="J." surname="Gettys" fullname="Jim Gettys">
1168      <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
1169      <address><email>jg@freedesktop.org</email></address>
1170    </author>
1171    <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
1172      <organization abbrev="HP">Hewlett-Packard Company</organization>
1173      <address><email>JeffMogul@acm.org</email></address>
1174    </author>
1175    <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
1176      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1177      <address><email>henrikn@microsoft.com</email></address>
1178    </author>
1179    <author initials="L." surname="Masinter" fullname="Larry Masinter">
1180      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1181      <address><email>LMM@acm.org</email></address>
1182    </author>
1183    <author initials="P." surname="Leach" fullname="Paul J. Leach">
1184      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1185      <address><email>paulle@microsoft.com</email></address>
1186    </author>
1187    <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
1188      <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1189      <address><email>timbl@w3.org</email></address>
1190    </author>
1191    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
1192      <organization abbrev="W3C">World Wide Web Consortium</organization>
1193      <address><email>ylafon@w3.org</email></address>
1194    </author>
1195    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
1196      <organization abbrev="greenbytes">greenbytes GmbH</organization>
1197      <address><email>julian.reschke@greenbytes.de</email></address>
1198    </author>
1199    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
1200  </front>
1201  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p4-conditional-&ID-VERSION;"/>
1202  <x:source href="p4-conditional.xml" basename="p4-conditional"/>
1203</reference>
1204
1205<reference anchor="Part6">
1206  <front>
1207    <title abbrev="HTTP/1.1">HTTP/1.1, part 6: Caching</title>
1208    <author initials="R." surname="Fielding" fullname="Roy T. Fielding" role="editor">
1209      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1210      <address><email>fielding@gbiv.com</email></address>
1211    </author>
1212    <author initials="J." surname="Gettys" fullname="Jim Gettys">
1213      <organization abbrev="Alcatel-Lucent">Alcatel-Lucent Bell Labs</organization>
1214      <address><email>jg@freedesktop.org</email></address>
1215    </author>
1216    <author initials="J." surname="Mogul" fullname="Jeffrey C. Mogul">
1217      <organization abbrev="HP">Hewlett-Packard Company</organization>
1218      <address><email>JeffMogul@acm.org</email></address>
1219    </author>
1220    <author initials="H." surname="Frystyk" fullname="Henrik Frystyk Nielsen">
1221      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1222      <address><email>henrikn@microsoft.com</email></address>
1223    </author>
1224    <author initials="L." surname="Masinter" fullname="Larry Masinter">
1225      <organization abbrev="Adobe">Adobe Systems Incorporated</organization>
1226      <address><email>LMM@acm.org</email></address>
1227    </author>
1228    <author initials="P." surname="Leach" fullname="Paul J. Leach">
1229      <organization abbrev="Microsoft">Microsoft Corporation</organization>
1230      <address><email>paulle@microsoft.com</email></address>
1231    </author>
1232    <author initials="T." surname="Berners-Lee" fullname="Tim Berners-Lee">
1233      <organization abbrev="W3C/MIT">World Wide Web Consortium</organization>
1234      <address><email>timbl@w3.org</email></address>
1235    </author>
1236    <author initials="Y." surname="Lafon" fullname="Yves Lafon" role="editor">
1237      <organization abbrev="W3C">World Wide Web Consortium</organization>
1238      <address><email>ylafon@w3.org</email></address>
1239    </author>
1240    <author initials="M." surname="Nottingham" fullname="Mark Nottingham" role="editor">
1241      <organization>Rackspace</organization>
1242      <address><email>mnot@mnot.net</email></address>
1243    </author>
1244    <author initials="J. F." surname="Reschke" fullname="Julian F. Reschke" role="editor">
1245      <organization abbrev="greenbytes">greenbytes GmbH</organization>
1246      <address><email>julian.reschke@greenbytes.de</email></address>
1247    </author>
1248    <date month="&ID-MONTH;" year="&ID-YEAR;"/>
1249  </front>
1250  <seriesInfo name="Internet-Draft" value="draft-ietf-httpbis-p6-cache-&ID-VERSION;"/>
1251  <x:source href="p6-cache.xml" basename="p6-cache"/>
1252</reference>
1253
1254<reference anchor="RFC2046">
1255  <front>
1256    <title abbrev="Media Types">Multipurpose Internet Mail Extensions (MIME) Part Two: Media Types</title>
1257    <author initials="N." surname="Freed" fullname="Ned Freed">
1258      <organization>Innosoft International, Inc.</organization>
1259      <address><email>ned@innosoft.com</email></address>
1260    </author>
1261    <author initials="N." surname="Borenstein" fullname="Nathaniel S. Borenstein">
1262      <organization>First Virtual Holdings</organization>
1263      <address><email>nsb@nsb.fv.com</email></address>
1264    </author>
1265    <date month="November" year="1996"/>
1266  </front>
1267  <seriesInfo name="RFC" value="2046"/>
1268</reference>
1269
1270<reference anchor="RFC2119">
1271  <front>
1272    <title>Key words for use in RFCs to Indicate Requirement Levels</title>
1273    <author initials="S." surname="Bradner" fullname="Scott Bradner">
1274      <organization>Harvard University</organization>
1275      <address><email>sob@harvard.edu</email></address>
1276    </author>
1277    <date month="March" year="1997"/>
1278  </front>
1279  <seriesInfo name="BCP" value="14"/>
1280  <seriesInfo name="RFC" value="2119"/>
1281</reference>
1282
1283<reference anchor="RFC5234">
1284  <front>
1285    <title abbrev="ABNF for Syntax Specifications">Augmented BNF for Syntax Specifications: ABNF</title>
1286    <author initials="D." surname="Crocker" fullname="Dave Crocker" role="editor">
1287      <organization>Brandenburg InternetWorking</organization>
1288      <address>
1289        <email>dcrocker@bbiw.net</email>
1290      </address> 
1291    </author>
1292    <author initials="P." surname="Overell" fullname="Paul Overell">
1293      <organization>THUS plc.</organization>
1294      <address>
1295        <email>paul.overell@thus.net</email>
1296      </address>
1297    </author>
1298    <date month="January" year="2008"/>
1299  </front>
1300  <seriesInfo name="STD" value="68"/>
1301  <seriesInfo name="RFC" value="5234"/>
1302</reference>
1303
1304</references>
1305
1306<references title="Informative References">
1307
1308<reference anchor="RFC2616">
1309  <front>
1310    <title>Hypertext Transfer Protocol -- HTTP/1.1</title>
1311    <author initials="R." surname="Fielding" fullname="R. Fielding">
1312      <organization>University of California, Irvine</organization>
1313      <address><email>fielding@ics.uci.edu</email></address>
1314    </author>
1315    <author initials="J." surname="Gettys" fullname="J. Gettys">
1316      <organization>W3C</organization>
1317      <address><email>jg@w3.org</email></address>
1318    </author>
1319    <author initials="J." surname="Mogul" fullname="J. Mogul">
1320      <organization>Compaq Computer Corporation</organization>
1321      <address><email>mogul@wrl.dec.com</email></address>
1322    </author>
1323    <author initials="H." surname="Frystyk" fullname="H. Frystyk">
1324      <organization>MIT Laboratory for Computer Science</organization>
1325      <address><email>frystyk@w3.org</email></address>
1326    </author>
1327    <author initials="L." surname="Masinter" fullname="L. Masinter">
1328      <organization>Xerox Corporation</organization>
1329      <address><email>masinter@parc.xerox.com</email></address>
1330    </author>
1331    <author initials="P." surname="Leach" fullname="P. Leach">
1332      <organization>Microsoft Corporation</organization>
1333      <address><email>paulle@microsoft.com</email></address>
1334    </author>
1335    <author initials="T." surname="Berners-Lee" fullname="T. Berners-Lee">
1336      <organization>W3C</organization>
1337      <address><email>timbl@w3.org</email></address>
1338    </author>
1339    <date month="June" year="1999"/>
1340  </front>
1341  <seriesInfo name="RFC" value="2616"/>
1342</reference>
1343
1344<reference anchor='RFC3864'>
1345  <front>
1346    <title>Registration Procedures for Message Header Fields</title>
1347    <author initials='G.' surname='Klyne' fullname='G. Klyne'>
1348      <organization>Nine by Nine</organization>
1349      <address><email>GK-IETF@ninebynine.org</email></address>
1350    </author>
1351    <author initials='M.' surname='Nottingham' fullname='M. Nottingham'>
1352      <organization>BEA Systems</organization>
1353      <address><email>mnot@pobox.com</email></address>
1354    </author>
1355    <author initials='J.' surname='Mogul' fullname='J. Mogul'>
1356      <organization>HP Labs</organization>
1357      <address><email>JeffMogul@acm.org</email></address>
1358    </author>
1359    <date year='2004' month='September' />
1360  </front>
1361  <seriesInfo name='BCP' value='90' />
1362  <seriesInfo name='RFC' value='3864' />
1363</reference>
1364
1365<reference anchor="RFC4288">
1366  <front>
1367    <title>Media Type Specifications and Registration Procedures</title>
1368    <author initials="N." surname="Freed" fullname="N. Freed">
1369      <organization>Sun Microsystems</organization>
1370      <address>
1371        <email>ned.freed@mrochek.com</email>
1372      </address>
1373    </author>
1374    <author initials="J." surname="Klensin" fullname="J. Klensin">
1375      <address>
1376        <email>klensin+ietf@jck.com</email>
1377      </address>
1378    </author>
1379    <date year="2005" month="December"/>
1380  </front>
1381  <seriesInfo name="BCP" value="13"/>
1382  <seriesInfo name="RFC" value="4288"/>
1383</reference>
1384
1385<reference anchor='RFC5226'>
1386  <front>
1387    <title>Guidelines for Writing an IANA Considerations Section in RFCs</title>
1388    <author initials='T.' surname='Narten' fullname='T. Narten'>
1389      <organization>IBM</organization>
1390      <address><email>narten@us.ibm.com</email></address>
1391    </author>
1392    <author initials='H.' surname='Alvestrand' fullname='H. Alvestrand'>
1393      <organization>Google</organization>
1394      <address><email>Harald@Alvestrand.no</email></address>
1395    </author>
1396    <date year='2008' month='May' />
1397  </front>
1398  <seriesInfo name='BCP' value='26' />
1399  <seriesInfo name='RFC' value='5226' />
1400</reference>
1401
1402</references>
1403
1404<section title="Internet Media Type multipart/byteranges" anchor="internet.media.type.multipart.byteranges">
1405<iref item="Media Type" subitem="multipart/byteranges" primary="true"/>
1406<iref item="multipart/byteranges Media Type" primary="true"/>
1407<t>
1408   When an HTTP 206 (Partial Content) response message includes the
1409   content of multiple ranges (a response to a request for multiple
1410   non-overlapping ranges), these are transmitted as a multipart
1411   message-body (<xref target="RFC2046" x:fmt="," x:sec="5.1"/>). The media type for this purpose is called
1412   "multipart/byteranges".  The following is to be registered with IANA <xref target="RFC4288"/>.
1413</t>
1414<x:note>
1415  <t>
1416    <x:h>Note:</x:h> Despite the name "multipart/byteranges" is not limited to the byte ranges only.
1417  </t>
1418</x:note>
1419<t>
1420   The multipart/byteranges media type includes one or more parts, each
1421   with its own Content-Type and Content-Range fields. The required
1422   boundary parameter specifies the boundary string used to separate
1423   each body-part.
1424</t>
1425<t>
1426  <list style="hanging" x:indent="12em">
1427    <t hangText="Type name:">
1428      multipart
1429    </t>
1430    <t hangText="Subtype name:">
1431      byteranges
1432    </t>
1433    <t hangText="Required parameters:">
1434      boundary
1435    </t>
1436    <t hangText="Optional parameters:">
1437      none
1438    </t>
1439    <t hangText="Encoding considerations:">
1440      only "7bit", "8bit", or "binary" are permitted
1441    </t>
1442    <t hangText="Security considerations:">
1443      none
1444    </t>
1445    <t hangText="Interoperability considerations:">
1446      none
1447    </t>
1448    <t hangText="Published specification:">
1449      This specification (see <xref target="internet.media.type.multipart.byteranges"/>).
1450    </t>
1451    <t hangText="Applications that use this media type:">
1452    </t>
1453    <t hangText="Additional information:">
1454      <list style="hanging">
1455        <t hangText="Magic number(s):">none</t>
1456        <t hangText="File extension(s):">none</t>
1457        <t hangText="Macintosh file type code(s):">none</t>
1458      </list>
1459    </t>
1460    <t hangText="Person and email address to contact for further information:">
1461      See Authors Section.
1462    </t>
1463    <t hangText="Intended usage:">
1464      COMMON
1465    </t>
1466    <t hangText="Restrictions on usage:">
1467      none
1468    </t>
1469    <t hangText="Author/Change controller:">
1470      IESG
1471    </t>
1472  </list>
1473</t>
1474<figure><preamble>
1475   For example:
1476</preamble><artwork type="example">
1477  HTTP/1.1 206 Partial Content
1478  Date: Wed, 15 Nov 1995 06:25:24 GMT
1479  Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
1480  Content-type: multipart/byteranges; boundary=THIS_STRING_SEPARATES
1481 
1482  --THIS_STRING_SEPARATES
1483  Content-type: application/pdf
1484  Content-range: bytes 500-999/8000
1485 
1486  ...the first range...
1487  --THIS_STRING_SEPARATES
1488  Content-type: application/pdf
1489  Content-range: bytes 7000-7999/8000
1490 
1491  ...the second range
1492  --THIS_STRING_SEPARATES--
1493</artwork></figure>
1494<figure><preamble>
1495   Other example:
1496</preamble>
1497<artwork type="example">
1498  HTTP/1.1 206 Partial Content
1499  Date: Tue, 14 Nov 1995 06:25:24 GMT
1500  Last-Modified: Tue, 14 July 04:58:08 GMT
1501  Content-type: multipart/byteranges; boundary=THIS_STRING_SEPARATES
1502 
1503  --THIS_STRING_SEPARATES
1504  Content-type: video/example
1505  Content-range: exampleunit 1.2-4.3/25
1506 
1507  ...the first range...
1508  --THIS_STRING_SEPARATES
1509  Content-type: video/example
1510  Content-range: exampleunit 11.2-14.3/25
1511 
1512  ...the second range
1513  --THIS_STRING_SEPARATES--
1514</artwork>
1515</figure>
1516<t>
1517      Notes:
1518  <list style="numbers">
1519      <t>Additional CRLFs &MAY; precede the first boundary string in the body.</t>
1520
1521      <t>Although <xref target="RFC2046"/> permits the boundary string to be
1522         quoted, some existing implementations handle a quoted boundary
1523         string incorrectly.</t>
1524
1525      <t>A number of browsers and servers were coded to an early draft
1526         of the byteranges specification to use a media type of
1527         multipart/x-byteranges<iref item="multipart/x-byteranges Media Type"/><iref item="Media Type" subitem="multipart/x-byteranges"/>, which is almost, but not quite
1528         compatible with the version documented in HTTP/1.1.</t>
1529  </list>
1530</t>
1531</section>
1532
1533<section title="Compatibility with Previous Versions" anchor="compatibility">
1534<section title="Changes from RFC 2616" anchor="changes.from.rfc.2616">
1535<t>
1536  Clarify that it is not ok to use a weak validator in a 206 response.
1537  (<xref target="status.206"/>)
1538</t>
1539<t>
1540  Change ABNF productions for header fields to only define the field value.
1541  (<xref target="header.field.definitions"/>)
1542</t>
1543<t>
1544  Clarify that multipart/byteranges can consist of a single part.
1545  (<xref target="internet.media.type.multipart.byteranges"/>)
1546</t>
1547</section>
1548
1549</section>
1550
1551<?BEGININC p5-range.abnf-appendix ?>
1552<section xmlns:x="http://purl.org/net/xml2rfc/ext" title="Collected ABNF" anchor="collected.abnf">
1553<figure>
1554<artwork type="abnf" name="p5-range.parsed-abnf">
1555<x:ref>Accept-Ranges</x:ref> = acceptable-ranges
1556
1557<x:ref>Content-Range</x:ref> = byte-content-range-spec / other-content-range-spec
1558
1559<x:ref>HTTP-date</x:ref> = &lt;HTTP-date, defined in [Part2], Section 8&gt;
1560
1561<x:ref>If-Range</x:ref> = entity-tag / HTTP-date
1562
1563<x:ref>OWS</x:ref> = &lt;OWS, defined in [Part1], Section 3.2.1&gt;
1564
1565<x:ref>Range</x:ref> = byte-ranges-specifier / other-ranges-specifier
1566
1567<x:ref>acceptable-ranges</x:ref> = ( *( "," OWS ) range-unit *( OWS "," [ OWS
1568 range-unit ] ) ) / "none"
1569
1570<x:ref>byte-content-range-spec</x:ref> = bytes-unit SP byte-range-resp-spec "/" (
1571 instance-length / "*" )
1572<x:ref>byte-range-resp-spec</x:ref> = ( first-byte-pos "-" last-byte-pos ) / "*"
1573<x:ref>byte-range-set</x:ref> = ( *( "," OWS ) byte-range-spec ) / (
1574 suffix-byte-range-spec *( OWS "," [ ( OWS byte-range-spec ) /
1575 suffix-byte-range-spec ] ) )
1576<x:ref>byte-range-spec</x:ref> = first-byte-pos "-" [ last-byte-pos ]
1577<x:ref>byte-ranges-specifier</x:ref> = bytes-unit "=" byte-range-set
1578<x:ref>bytes-unit</x:ref> = "bytes"
1579
1580<x:ref>entity-tag</x:ref> = &lt;entity-tag, defined in [Part4], Section 2.3&gt;
1581
1582<x:ref>first-byte-pos</x:ref> = 1*DIGIT
1583
1584<x:ref>instance-length</x:ref> = 1*DIGIT
1585
1586<x:ref>last-byte-pos</x:ref> = 1*DIGIT
1587
1588<x:ref>other-content-range-spec</x:ref> = other-range-unit SP other-range-resp-spec
1589<x:ref>other-range-resp-spec</x:ref> = *CHAR
1590<x:ref>other-range-set</x:ref> = 1*CHAR
1591<x:ref>other-range-unit</x:ref> = token
1592<x:ref>other-ranges-specifier</x:ref> = other-range-unit "=" other-range-set
1593
1594<x:ref>range-unit</x:ref> = bytes-unit / other-range-unit
1595
1596<x:ref>suffix-byte-range-spec</x:ref> = "-" suffix-length
1597<x:ref>suffix-length</x:ref> = 1*DIGIT
1598
1599<x:ref>token</x:ref> = &lt;token, defined in [Part1], Section 3.2.4&gt;
1600</artwork>
1601</figure>
1602<figure><preamble>ABNF diagnostics:</preamble><artwork type="inline">
1603; Accept-Ranges defined but not used
1604; Content-Range defined but not used
1605; If-Range defined but not used
1606; Range defined but not used
1607</artwork></figure></section>
1608<?ENDINC p5-range.abnf-appendix ?>
1609
1610
1611<section title="Change Log (to be removed by RFC Editor before publication)" anchor="change.log">
1612
1613<section title="Since RFC 2616">
1614<t>
1615  Extracted relevant partitions from <xref target="RFC2616"/>.
1616</t>
1617</section>
1618
1619<section title="Since draft-ietf-httpbis-p5-range-00">
1620<t>
1621  Closed issues:
1622  <list style="symbols"> 
1623    <t>
1624      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/18"/>:
1625      "Cache validators in 206 responses"
1626      (<eref target="http://purl.org/NET/http-errata#ifrange206"/>)
1627    </t>
1628    <t>
1629      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/35"/>:
1630      "Normative and Informative references"
1631    </t>
1632    <t>
1633      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/86"/>:
1634      "Normative up-to-date references"
1635    </t>
1636  </list>
1637</t>
1638</section>
1639
1640<section title="Since draft-ietf-httpbis-p5-range-01">
1641<t>
1642  Closed issues:
1643  <list style="symbols"> 
1644    <t>
1645      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/55"/>:
1646      "Updating to RFC4288"
1647    </t>
1648  </list>
1649</t>
1650<t>
1651  Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
1652  <list style="symbols"> 
1653    <t>
1654      Add explicit references to BNF syntax and rules imported from other parts of the specification.
1655    </t>
1656  </list>
1657</t>
1658</section>
1659
1660<section title="Since draft-ietf-httpbis-p5-range-02" anchor="changes.since.02">
1661<t>
1662  Ongoing work on IANA Message Header Field Registration (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/40"/>):
1663  <list style="symbols"> 
1664    <t>
1665      Reference RFC 3984, and update header field registrations for headers defined
1666      in this document.
1667    </t>
1668  </list>
1669</t>
1670</section>
1671
1672<section title="Since draft-ietf-httpbis-p5-range-03" anchor="changes.since.03">
1673<t>
1674  None.
1675</t>
1676</section>
1677
1678<section title="Since draft-ietf-httpbis-p5-range-04" anchor="changes.since.04">
1679<t>
1680  Closed issues:
1681  <list style="symbols"> 
1682    <t>
1683      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/133"/>:
1684      "multipart/byteranges minimum number of parts"
1685    </t>
1686  </list>
1687</t>
1688<t>
1689  Ongoing work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
1690  <list style="symbols"> 
1691    <t>
1692      Use "/" instead of "|" for alternatives.
1693    </t>
1694    <t>
1695      Introduce new ABNF rules for "bad" whitespace ("BWS"), optional
1696      whitespace ("OWS") and required whitespace ("RWS").
1697    </t>
1698    <t>
1699      Rewrite ABNFs to spell out whitespace rules, factor out
1700      header field value format definitions.
1701    </t>
1702  </list>
1703</t>
1704</section>
1705
1706<section title="Since draft-ietf-httpbis-p5-range-05" anchor="changes.since.05">
1707<t>
1708  Closed issues:
1709  <list style="symbols"> 
1710    <t>
1711      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/142"/>:
1712      "State base for *-byte-pos and suffix-length"
1713    </t>
1714  </list>
1715</t>
1716<t>
1717  Ongoing work on Custom Ranges (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/85"/>):
1718  <list style="symbols"> 
1719    <t>
1720      Remove bias in favor of byte ranges; allow custom ranges in ABNF.
1721    </t>
1722  </list>
1723</t>
1724<t>
1725  Final work on ABNF conversion (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/36"/>):
1726  <list style="symbols"> 
1727    <t>
1728      Add appendix containing collected and expanded ABNF, reorganize ABNF introduction.
1729    </t>
1730  </list>
1731</t>
1732</section>
1733
1734<section title="Since draft-ietf-httpbis-p5-range-06" anchor="changes.since.06">
1735<t>
1736  Closed issues:
1737  <list style="symbols"> 
1738    <t>
1739      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/161"/>:
1740      "base for numeric protocol elements"
1741    </t>
1742  </list>
1743</t>
1744</section>
1745
1746<section title="Since draft-ietf-httpbis-p5-range-07" anchor="changes.since.07">
1747<t>
1748  Closed issues:
1749  <list style="symbols">
1750    <t>
1751      Fixed discrepancy in the If-Range definition about allowed validators.
1752    </t>
1753    <t>
1754      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/150" />: "multipart/byteranges for custom range units"
1755    </t>
1756    <t>
1757      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/151" />: "range unit missing from other-ranges-specifier in Range header"
1758    </t>
1759    <t>
1760      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/198"/>:
1761      "move IANA registrations for optional status codes"
1762    </t>
1763  </list>
1764</t>
1765</section>
1766
1767<section title="Since draft-ietf-httpbis-p5-range-08" anchor="changes.since.08">
1768<t>
1769  No significant changes.
1770</t>
1771</section>
1772
1773<section title="Since draft-ietf-httpbis-p5-range-09" anchor="changes.since.09">
1774<t>
1775 No significant changes.
1776</t>
1777</section>
1778
1779<section title="Since draft-ietf-httpbis-p5-range-10" anchor="changes.since.10">
1780<t>
1781  Closed issues:
1782  <list style="symbols"> 
1783    <t>
1784      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/69"/>:
1785      "Clarify 'Requested Variant'"
1786    </t>
1787    <t>
1788      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/109"/>:
1789      "Clarify entity / representation / variant terminology"
1790    </t>
1791    <t>
1792      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/220"/>:
1793      "consider removing the 'changes from 2068' sections"
1794    </t>
1795  </list>
1796</t>
1797<t>
1798  Ongoing work on Custom Ranges (<eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/85"/>):
1799  <list style="symbols"> 
1800    <t>
1801      Add IANA registry.
1802    </t>
1803  </list>
1804</t>
1805</section>
1806
1807<section title="Since draft-ietf-httpbis-p5-range-11" anchor="changes.since.11">
1808<t>
1809  Closed issues:
1810  <list style="symbols"> 
1811    <t>
1812      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/217"/>:
1813      "Caches can't be required to serve ranges"
1814    </t>
1815  </list>
1816</t>
1817</section>
1818
1819<section title="Since draft-ietf-httpbis-p5-range-12" anchor="changes.since.12">
1820<t>
1821  Closed issues:
1822  <list style="symbols"> 
1823    <t>
1824      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/224"/>:
1825      "Header Classification"
1826    </t>
1827  </list>
1828</t>
1829</section>
1830
1831<section title="Since draft-ietf-httpbis-p5-range-13" anchor="changes.since.13">
1832<t>
1833  Closed issues:
1834  <list style="symbols">
1835    <t>
1836      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/276"/>:
1837      "untangle ABNFs for header fields"
1838    </t>
1839  </list>
1840</t>
1841</section>
1842
1843<section title="Since draft-ietf-httpbis-p5-range-14" anchor="changes.since.14">
1844<t>
1845  None.
1846</t>
1847</section>
1848
1849<section title="Since draft-ietf-httpbis-p5-range-15" anchor="changes.since.15">
1850<t>
1851  Closed issues:
1852  <list style="symbols">
1853    <t>
1854      <eref target="http://trac.tools.ietf.org/wg/httpbis/trac/ticket/175"/>:
1855      "Security consideration: range flooding"
1856    </t>
1857  </list>
1858</t>
1859</section>
1860
1861<section title="Since draft-ietf-httpbis-p5-range-16" anchor="changes.since.16">
1862<t>
1863  Closed issues:
1864  <list style="symbols"> 
1865    <t>
1866      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/186"/>:
1867      "Document HTTP's error-handling philosophy"
1868    </t>
1869    <t>
1870      <eref target="http://trac.tools.ietf.org/wg/httpbis/trac/ticket/301"/>:
1871      "Content-Range on responses other than 206"
1872    </t>
1873    <t>
1874      <eref target="http://trac.tools.ietf.org/wg/httpbis/trac/ticket/319"/>:
1875      "case sensitivity of ranges in p5"
1876    </t>
1877  </list>
1878</t>
1879</section>
1880
1881<section title="Since draft-ietf-httpbis-p5-range-17" anchor="changes.since.17">
1882<t>
1883  None.
1884</t>
1885</section>
1886
1887<section title="Since draft-ietf-httpbis-p5-range-18" anchor="changes.since.18">
1888<t>
1889  Closed issues:
1890  <list style="symbols"> 
1891    <t>
1892      <eref target="http://tools.ietf.org/wg/httpbis/trac/ticket/311"/>:
1893      "Add limitations to Range to reduce its use as a denial-of-service tool"
1894    </t>
1895  </list>
1896</t>
1897</section>
1898
1899</section>
1900
1901</back>
1902</rfc>
Note: See TracBrowser for help on using the repository browser.