draft-ietf-httpbis-p5-range-11.txt   draft-ietf-httpbis-p5-range-12.txt 
HTTPbis Working Group R. Fielding, Ed. HTTPbis Working Group R. Fielding, Ed.
Internet-Draft Day Software Internet-Draft Day Software
Obsoletes: 2616 (if approved) J. Gettys Obsoletes: 2616 (if approved) J. Gettys
Intended status: Standards Track Alcatel-Lucent Intended status: Standards Track Alcatel-Lucent
Expires: February 5, 2011 J. Mogul Expires: April 28, 2011 J. Mogul
HP HP
H. Frystyk H. Frystyk
Microsoft Microsoft
L. Masinter L. Masinter
Adobe Systems Adobe Systems
P. Leach P. Leach
Microsoft Microsoft
T. Berners-Lee T. Berners-Lee
W3C/MIT W3C/MIT
Y. Lafon, Ed. Y. Lafon, Ed.
W3C W3C
J. Reschke, Ed. J. Reschke, Ed.
greenbytes greenbytes
August 4, 2010 October 25, 2010
HTTP/1.1, part 5: Range Requests and Partial Responses HTTP/1.1, part 5: Range Requests and Partial Responses
draft-ietf-httpbis-p5-range-11 draft-ietf-httpbis-p5-range-12
Abstract Abstract
The Hypertext Transfer Protocol (HTTP) is an application-level The Hypertext Transfer Protocol (HTTP) is an application-level
protocol for distributed, collaborative, hypermedia information protocol for distributed, collaborative, hypermedia information
systems. HTTP has been in use by the World Wide Web global systems. HTTP has been in use by the World Wide Web global
information initiative since 1990. This document is Part 5 of the information initiative since 1990. This document is Part 5 of the
seven-part specification that defines the protocol referred to as seven-part specification that defines the protocol referred to as
"HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 5 defines "HTTP/1.1" and, taken together, obsoletes RFC 2616. Part 5 defines
range-specific requests and the rules for constructing and combining range-specific requests and the rules for constructing and combining
responses to those requests. responses to those requests.
Editorial Note (To be removed by RFC Editor) Editorial Note (To be removed by RFC Editor)
Discussion of this draft should take place on the HTTPBIS working Discussion of this draft should take place on the HTTPBIS working
group mailing list (ietf-http-wg@w3.org). The current issues list is group mailing list (ietf-http-wg@w3.org). The current issues list is
at <http://tools.ietf.org/wg/httpbis/trac/report/3> and related at <http://tools.ietf.org/wg/httpbis/trac/report/3> and related
documents (including fancy diffs) can be found at documents (including fancy diffs) can be found at
<http://tools.ietf.org/wg/httpbis/>. <http://tools.ietf.org/wg/httpbis/>.
The changes in this draft are summarized in Appendix D.12. The changes in this draft are summarized in Appendix D.13.
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.
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 February 5, 2011. This Internet-Draft will expire on April 28, 2011.
Copyright Notice Copyright Notice
Copyright (c) 2010 IETF Trust and the persons identified as the Copyright (c) 2010 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
skipping to change at page 3, line 7 skipping to change at page 2, line 47
modifications of such material outside the IETF Standards Process. modifications of such material outside the IETF Standards Process.
Without obtaining an adequate license from the person(s) controlling Without obtaining an adequate license from the person(s) controlling
the copyright in such materials, this document may not be modified the copyright in such materials, this document may not be modified
outside the IETF Standards Process, and derivative works of it may outside the IETF Standards Process, and derivative works of it may
not be created outside the IETF Standards Process, except to format not be created outside the IETF Standards Process, except to format
it for publication as an RFC or to translate it into languages other it for publication as an RFC or to translate it into languages other
than English. than English.
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 5 1.1. Requirements . . . . . . . . . . . . . . . . . . . . . . . 4
1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 5 1.2. Syntax Notation . . . . . . . . . . . . . . . . . . . . . 4
1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 6 1.2.1. Core Rules . . . . . . . . . . . . . . . . . . . . . . 5
1.2.2. ABNF Rules defined in other Parts of the 1.2.2. ABNF Rules defined in other Parts of the
Specification . . . . . . . . . . . . . . . . . . . . 6 Specification . . . . . . . . . . . . . . . . . . . . 5
2. Range Units . . . . . . . . . . . . . . . . . . . . . . . . . 6 2. Range Units . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1. Range Specifier Registry . . . . . . . . . . . . . . . . . 6 2.1. Range Specifier Registry . . . . . . . . . . . . . . . . . 5
3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 7 3. Status Code Definitions . . . . . . . . . . . . . . . . . . . 6
3.1. 206 Partial Content . . . . . . . . . . . . . . . . . . . 7 3.1. 206 Partial Content . . . . . . . . . . . . . . . . . . . 6
3.2. 416 Requested Range Not Satisfiable . . . . . . . . . . . 8 3.2. 416 Requested Range Not Satisfiable . . . . . . . . . . . 7
4. Combining Ranges . . . . . . . . . . . . . . . . . . . . . . . 8 4. Combining Ranges . . . . . . . . . . . . . . . . . . . . . . . 7
5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 8 5. Header Field Definitions . . . . . . . . . . . . . . . . . . . 7
5.1. Accept-Ranges . . . . . . . . . . . . . . . . . . . . . . 9 5.1. Accept-Ranges . . . . . . . . . . . . . . . . . . . . . . 8
5.2. Content-Range . . . . . . . . . . . . . . . . . . . . . . 9 5.2. Content-Range . . . . . . . . . . . . . . . . . . . . . . 8
5.3. If-Range . . . . . . . . . . . . . . . . . . . . . . . . . 11 5.3. If-Range . . . . . . . . . . . . . . . . . . . . . . . . . 10
5.4. Range . . . . . . . . . . . . . . . . . . . . . . . . . . 12 5.4. Range . . . . . . . . . . . . . . . . . . . . . . . . . . 11
5.4.1. Byte Ranges . . . . . . . . . . . . . . . . . . . . . 12 5.4.1. Byte Ranges . . . . . . . . . . . . . . . . . . . . . 11
5.4.2. Range Retrieval Requests . . . . . . . . . . . . . . . 14 5.4.2. Range Retrieval Requests . . . . . . . . . . . . . . . 13
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14
6.1. Status Code Registration . . . . . . . . . . . . . . . . . 15 6.1. Status Code Registration . . . . . . . . . . . . . . . . . 14
6.2. Header Field Registration . . . . . . . . . . . . . . . . 15 6.2. Header Field Registration . . . . . . . . . . . . . . . . 14
6.3. Range Specifier Registration . . . . . . . . . . . . . . . 16 6.3. Range Specifier Registration . . . . . . . . . . . . . . . 15
7. Security Considerations . . . . . . . . . . . . . . . . . . . 16 7. Security Considerations . . . . . . . . . . . . . . . . . . . 15
8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 16 8. Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . 15
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 15
9.1. Normative References . . . . . . . . . . . . . . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . . 15
9.2. Informative References . . . . . . . . . . . . . . . . . . 17 9.2. Informative References . . . . . . . . . . . . . . . . . . 16
Appendix A. Internet Media Type multipart/byteranges . . . . . . 17 Appendix A. Internet Media Type multipart/byteranges . . . . . . 16
Appendix B. Compatibility with Previous Versions . . . . . . . . 20 Appendix B. Compatibility with Previous Versions . . . . . . . . 19
B.1. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 20 B.1. Changes from RFC 2616 . . . . . . . . . . . . . . . . . . 19
Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 20 Appendix C. Collected ABNF . . . . . . . . . . . . . . . . . . . 19
Appendix D. Change Log (to be removed by RFC Editor before Appendix D. Change Log (to be removed by RFC Editor before
publication) . . . . . . . . . . . . . . . . . . . . 21 publication) . . . . . . . . . . . . . . . . . . . . 20
D.1. Since RFC2616 . . . . . . . . . . . . . . . . . . . . . . 21 D.1. Since RFC 2616 . . . . . . . . . . . . . . . . . . . . . . 20
D.2. Since draft-ietf-httpbis-p5-range-00 . . . . . . . . . . . 21 D.2. Since draft-ietf-httpbis-p5-range-00 . . . . . . . . . . . 20
D.3. Since draft-ietf-httpbis-p5-range-01 . . . . . . . . . . . 22 D.3. Since draft-ietf-httpbis-p5-range-01 . . . . . . . . . . . 21
D.4. Since draft-ietf-httpbis-p5-range-02 . . . . . . . . . . . 22 D.4. Since draft-ietf-httpbis-p5-range-02 . . . . . . . . . . . 21
D.5. Since draft-ietf-httpbis-p5-range-03 . . . . . . . . . . . 22 D.5. Since draft-ietf-httpbis-p5-range-03 . . . . . . . . . . . 21
D.6. Since draft-ietf-httpbis-p5-range-04 . . . . . . . . . . . 22 D.6. Since draft-ietf-httpbis-p5-range-04 . . . . . . . . . . . 21
D.7. Since draft-ietf-httpbis-p5-range-05 . . . . . . . . . . . 22 D.7. Since draft-ietf-httpbis-p5-range-05 . . . . . . . . . . . 21
D.8. Since draft-ietf-httpbis-p5-range-06 . . . . . . . . . . . 23 D.8. Since draft-ietf-httpbis-p5-range-06 . . . . . . . . . . . 22
D.9. Since draft-ietf-httpbis-p5-range-07 . . . . . . . . . . . 23 D.9. Since draft-ietf-httpbis-p5-range-07 . . . . . . . . . . . 22
D.10. Since draft-ietf-httpbis-p5-range-08 . . . . . . . . . . . 23 D.10. Since draft-ietf-httpbis-p5-range-08 . . . . . . . . . . . 22
D.11. Since draft-ietf-httpbis-p5-range-09 . . . . . . . . . . . 23 D.11. Since draft-ietf-httpbis-p5-range-09 . . . . . . . . . . . 22
D.12. Since draft-ietf-httpbis-p5-range-10 . . . . . . . . . . . 23 D.12. Since draft-ietf-httpbis-p5-range-10 . . . . . . . . . . . 22
D.13. Since draft-ietf-httpbis-p5-range-11 . . . . . . . . . . . 23
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
1. Introduction 1. Introduction
HTTP clients often encounter interrupted data transfers as a result HTTP clients often encounter interrupted data transfers as a result
of cancelled requests or dropped connections. When a cache has of cancelled requests or dropped connections. When a cache has
stored a partial representation, it is desirable to request the stored a partial representation, it is desirable to request the
remainder of that representation in a subsequent request rather than remainder of that representation in a subsequent request rather than
transfer the entire representation. There are also a number of Web transfer the entire representation. There are also a number of Web
applications that benefit from being able to request only a subset of applications that benefit from being able to request only a subset of
a larger representation, such as a single page of a very large a larger representation, such as a single page of a very large
skipping to change at page 6, line 44 skipping to change at page 5, line 44
range-unit = bytes-unit / other-range-unit range-unit = bytes-unit / other-range-unit
bytes-unit = "bytes" bytes-unit = "bytes"
other-range-unit = token other-range-unit = token
HTTP/1.1 has been designed to allow implementations of applications HTTP/1.1 has been designed to allow implementations of applications
that do not depend on knowledge of ranges. The only range unit that do not depend on knowledge of ranges. The only range unit
defined by HTTP/1.1 is "bytes". Additional specifiers can be defined defined by HTTP/1.1 is "bytes". Additional specifiers can be defined
as described in Section 2.1. as described in Section 2.1.
If a range unit is not understood in a request, a server MUST ignore If a range unit is not understood in a request, a server MUST ignore
the whole Range header (Section 5.4). If a range unit is not the whole Range header field (Section 5.4). If a range unit is not
understood in a response, an intermediary SHOULD pass the response to understood in a response, an intermediary SHOULD pass the response to
the client; a client MUST fail. the client; a client MUST fail.
2.1. Range Specifier Registry 2.1. Range Specifier Registry
The HTTP Ranger Specifier Registry defines the name space for the The HTTP Ranger Specifier Registry defines the name space for the
range specifier names. range specifier names.
Registrations MUST include the following fields: Registrations MUST include the following fields:
skipping to change at page 7, line 50 skipping to change at page 6, line 50
and/or Vary, if the header field would have been sent in a 200 and/or Vary, if the header field would have been sent in a 200
response to the same request response to the same request
If the 206 response is the result of an If-Range request, the If the 206 response is the result of an If-Range request, the
response SHOULD NOT include other representation header fields. response SHOULD NOT include other representation header fields.
Otherwise, the response MUST include all of the representation header Otherwise, the response MUST include all of the representation header
fields that would have been returned with a 200 (OK) response to the fields that would have been returned with a 200 (OK) response to the
same request. same request.
A cache MUST NOT combine a 206 response with other previously cached A cache MUST NOT combine a 206 response with other previously cached
content if the ETag or Last-Modified headers do not match exactly, content if the ETag or Last-Modified header fields do not match
see Section 4. exactly, see Section 4.
A cache that does not support the Range and Content-Range headers A cache that does not support the Range and Content-Range header
MUST NOT cache 206 (Partial Content) responses. Furthermore, if a fields MUST NOT cache 206 (Partial Content) responses. Furthermore,
response uses a range unit that is not understood by the cache, then if a response uses a range unit that is not understood by the cache,
it MUST NOT be cached either. then it MUST NOT be cached either.
3.2. 416 Requested Range Not Satisfiable 3.2. 416 Requested Range Not Satisfiable
A server SHOULD return a response with this status code if a request A server SHOULD return a response with this status code if a request
included a Range request-header field (Section 5.4), and none of the included a Range request-header field (Section 5.4), and none of the
ranges-specifier values in this field overlap the current extent of ranges-specifier values in this field overlap the current extent of
the selected resource, and the request did not include an If-Range the selected resource, and the request did not include an If-Range
request-header field (Section 5.3). (For byte-ranges, this means request-header field (Section 5.3). (For byte-ranges, this means
that the first-byte-pos of all of the byte-range-spec values were that the first-byte-pos of all of the byte-range-spec values were
greater than the current length of the selected resource.) greater than the current length of the selected resource.)
skipping to change at page 9, line 19 skipping to change at page 8, line 19
Accept-Ranges = "Accept-Ranges" ":" OWS Accept-Ranges-v Accept-Ranges = "Accept-Ranges" ":" OWS Accept-Ranges-v
Accept-Ranges-v = acceptable-ranges Accept-Ranges-v = acceptable-ranges
acceptable-ranges = 1#range-unit / "none" acceptable-ranges = 1#range-unit / "none"
Origin servers that accept byte-range requests MAY send Origin servers that accept byte-range requests MAY send
Accept-Ranges: bytes Accept-Ranges: bytes
but are not required to do so. Clients MAY generate range requests but are not required to do so. Clients MAY generate range requests
without having received this header for the resource involved. Range without having received this header field for the resource involved.
units are defined in Section 2. Range units are defined in Section 2.
Servers that do not accept any kind of range request for a resource Servers that do not accept any kind of range request for a resource
MAY send MAY send
Accept-Ranges: none Accept-Ranges: none
to advise the client not to attempt a range request. to advise the client not to attempt a range request.
5.2. Content-Range 5.2. Content-Range
skipping to change at page 10, line 7 skipping to change at page 9, line 7
byte-range-resp-spec = (first-byte-pos "-" last-byte-pos) byte-range-resp-spec = (first-byte-pos "-" last-byte-pos)
/ "*" / "*"
instance-length = 1*DIGIT instance-length = 1*DIGIT
other-content-range-spec = other-range-unit SP other-content-range-spec = other-range-unit SP
other-range-resp-spec other-range-resp-spec
other-range-resp-spec = *CHAR other-range-resp-spec = *CHAR
The header SHOULD indicate the total length of the full The header field SHOULD indicate the total length of the full
representation, unless this length is unknown or difficult to representation, unless this length is unknown or difficult to
determine. The asterisk "*" character means that the instance-length determine. The asterisk "*" character means that the instance-length
is unknown at the time when the response was generated. is unknown at the time when the response was generated.
Unlike byte-ranges-specifier values (see Section 5.4.1), a byte- Unlike byte-ranges-specifier values (see Section 5.4.1), a byte-
range-resp-spec MUST only specify one range, and MUST contain range-resp-spec MUST only specify one range, and MUST contain
absolute byte positions for both the first and last byte of the absolute byte positions for both the first and last byte of the
range. range.
A byte-content-range-spec with a byte-range-resp-spec whose last- A byte-content-range-spec with a byte-range-resp-spec whose last-
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bytes 500-1233/1234 bytes 500-1233/1234
o The last 500 bytes: o The last 500 bytes:
bytes 734-1233/1234 bytes 734-1233/1234
When an HTTP message includes the content of a single range (for When an HTTP message includes the content of a single range (for
example, a response to a request for a single range, or to a request example, a response to a request for a single range, or to a request
for a set of ranges that overlap without any holes), this content is for a set of ranges that overlap without any holes), this content is
transmitted with a Content-Range header, and a Content-Length header transmitted with a Content-Range header field, and a Content-Length
showing the number of bytes actually transferred. For example, header field showing the number of bytes actually transferred. For
example,
HTTP/1.1 206 Partial Content HTTP/1.1 206 Partial Content
Date: Wed, 15 Nov 1995 06:25:24 GMT Date: Wed, 15 Nov 1995 06:25:24 GMT
Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT Last-Modified: Wed, 15 Nov 1995 04:58:08 GMT
Content-Range: bytes 21010-47021/47022 Content-Range: bytes 21010-47021/47022
Content-Length: 26012 Content-Length: 26012
Content-Type: image/gif Content-Type: image/gif
When an HTTP message includes the content of multiple ranges (for When an HTTP message includes the content of multiple ranges (for
example, a response to a request for multiple non-overlapping example, a response to a request for multiple non-overlapping
skipping to change at page 11, line 43 skipping to change at page 10, line 44
If the server receives a request (other than one including an If- If the server receives a request (other than one including an If-
Range request-header field) with an unsatisfiable Range request- Range request-header field) with an unsatisfiable Range request-
header field (that is, all of whose byte-range-spec values have a header field (that is, all of whose byte-range-spec values have a
first-byte-pos value greater than the current length of the selected first-byte-pos value greater than the current length of the selected
resource), it SHOULD return a response code of 416 (Requested range resource), it SHOULD return a response code of 416 (Requested range
not satisfiable) (Section 3.2). not satisfiable) (Section 3.2).
Note: Clients cannot depend on servers to send a 416 (Requested Note: Clients cannot depend on servers to send a 416 (Requested
range not satisfiable) response instead of a 200 (OK) response for range not satisfiable) response instead of a 200 (OK) response for
an unsatisfiable Range request-header, since not all servers an unsatisfiable Range request-header field, since not all servers
implement this request-header. implement this request-header field.
5.3. If-Range 5.3. If-Range
If a client has a partial copy of a representation in its cache, and If a client has a partial copy of a representation in its cache, and
wishes to have an up-to-date copy of the entire representation in its wishes to have an up-to-date copy of the entire representation in its
cache, it could use the Range request-header with a conditional GET cache, it could use the Range request-header field with a conditional
(using either or both of If-Unmodified-Since and If-Match.) However, GET (using either or both of If-Unmodified-Since and If-Match.)
if the condition fails because the representation has been modified, However, if the condition fails because the representation has been
the client would then have to make a second request to obtain the modified, the client would then have to make a second request to
entire current representation. obtain the entire current representation.
The "If-Range" request-header field allows a client to "short- The "If-Range" request-header field allows a client to "short-
circuit" the second request. Informally, its meaning is "if the circuit" the second request. Informally, its meaning is "if the
representation is unchanged, send me the part(s) that I am missing; representation is unchanged, send me the part(s) that I am missing;
otherwise, send me the entire new representation". otherwise, send me the entire new representation".
If-Range = "If-Range" ":" OWS If-Range-v If-Range = "If-Range" ":" OWS If-Range-v
If-Range-v = entity-tag / HTTP-date If-Range-v = entity-tag / HTTP-date
If the client has no entity-tag for a representation, but does have a If the client has no entity-tag for a representation, but does have a
Last-Modified date, it MAY use that date in an If-Range header. (The Last-Modified date, it MAY use that date in an If-Range header field.
server can distinguish between a valid HTTP-date and any form of (The server can distinguish between a valid HTTP-date and any form of
entity-tag by examining no more than two characters.) The If-Range entity-tag by examining no more than two characters.) The If-Range
header SHOULD only be used together with a Range header, and MUST be header field SHOULD only be used together with a Range header field,
ignored if the request does not include a Range header, or if the and MUST be ignored if the request does not include a Range header
server does not support the sub-range operation. field, or if the server does not support the sub-range operation.
If the entity-tag given in the If-Range header matches the current If the entity-tag given in the If-Range header field matches the
cache validator for the representation, then the server SHOULD current cache validator for the representation, then the server
provide the specified sub-range of the representation using a 206 SHOULD provide the specified sub-range of the representation using a
(Partial Content) response. If the cache validator does not match, 206 (Partial Content) response. If the cache validator does not
then the server SHOULD return the entire representation using a 200 match, then the server SHOULD return the entire representation using
(OK) response. a 200 (OK) response.
5.4. Range 5.4. Range
5.4.1. Byte Ranges 5.4.1. Byte Ranges
Since all HTTP representations are transferred as sequences of bytes, Since all HTTP representations are transferred as sequences of bytes,
the concept of a byte range is meaningful for any HTTP the concept of a byte range is meaningful for any HTTP
representation. (However, not all clients and servers need to representation. (However, not all clients and servers need to
support byte-range operations.) support byte-range operations.)
skipping to change at page 14, line 39 skipping to change at page 13, line 39
The "Range" request-header field defines the GET method (conditional The "Range" request-header field defines the GET method (conditional
or not) to request one or more sub-ranges of the response or not) to request one or more sub-ranges of the response
representation body, instead of the entire representation body. representation body, instead of the entire representation body.
Range = "Range" ":" OWS Range-v Range = "Range" ":" OWS Range-v
Range-v = byte-ranges-specifier Range-v = byte-ranges-specifier
/ other-ranges-specifier / other-ranges-specifier
other-ranges-specifier = other-range-unit "=" other-range-set other-ranges-specifier = other-range-unit "=" other-range-set
other-range-set = 1*CHAR other-range-set = 1*CHAR
A server MAY ignore the Range header. However, HTTP/1.1 origin A server MAY ignore the Range header field. However, HTTP/1.1 origin
servers and intermediate caches ought to support byte ranges when servers and intermediate caches ought to support byte ranges when
possible, since Range supports efficient recovery from partially possible, since Range supports efficient recovery from partially
failed transfers, and supports efficient partial retrieval of large failed transfers, and supports efficient partial retrieval of large
representations. representations.
If the server supports the Range header and the specified range or If the server supports the Range header field and the specified range
ranges are appropriate for the representation: or ranges are appropriate for the representation:
o The presence of a Range header in an unconditional GET modifies o The presence of a Range header field in an unconditional GET
what is returned if the GET is otherwise successful. In other modifies what is returned if the GET is otherwise successful. In
words, the response carries a status code of 206 (Partial Content) other words, the response carries a status code of 206 (Partial
instead of 200 (OK). Content) instead of 200 (OK).
o The presence of a Range header in a conditional GET (a request o The presence of a Range header field in a conditional GET (a
using one or both of If-Modified-Since and If-None-Match, or one request using one or both of If-Modified-Since and If-None-Match,
or both of If-Unmodified-Since and If-Match) modifies what is or one or both of If-Unmodified-Since and If-Match) modifies what
returned if the GET is otherwise successful and the condition is is returned if the GET is otherwise successful and the condition
true. It does not affect the 304 (Not Modified) response returned is true. It does not affect the 304 (Not Modified) response
if the conditional is false. returned if the conditional is false.
In some cases, it might be more appropriate to use the If-Range In some cases, it might be more appropriate to use the If-Range
header (see Section 5.3) in addition to the Range header. header field (see Section 5.3) in addition to the Range header field.
If a proxy that supports ranges receives a Range request, forwards If a proxy that supports ranges receives a Range request, forwards
the request to an inbound server, and receives an entire the request to an inbound server, and receives an entire
representation in reply, it SHOULD only return the requested range to representation in reply, it MAY only return the requested range to
its client. It SHOULD store the entire received response in its its client.
cache if that is consistent with its cache allocation policies.
6. IANA Considerations 6. IANA Considerations
6.1. Status Code Registration 6.1. Status Code Registration
The HTTP Status Code Registry located at The HTTP Status Code Registry located at
<http://www.iana.org/assignments/http-status-codes> shall be updated <http://www.iana.org/assignments/http-status-codes> shall be updated
with the registrations below: with the registrations below:
+-------+---------------------------------+-------------+ +-------+---------------------------------+-------------+
skipping to change at page 16, line 44 skipping to change at page 15, line 44
Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi Larry Masinter, Jeff Mogul, Lou Montulli, David W. Morris, Luigi
Rizzo, and Bill Weihl. Rizzo, and Bill Weihl.
9. References 9. References
9.1. Normative References 9.1. Normative References
[Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., [Part1] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed.,
and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections, and J. Reschke, Ed., "HTTP/1.1, part 1: URIs, Connections,
and Message Parsing", draft-ietf-httpbis-p1-messaging-11 and Message Parsing", draft-ietf-httpbis-p1-messaging-12
(work in progress), August 2010. (work in progress), October 2010.
[Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H., [Part4] Fielding, R., Ed., Gettys, J., Mogul, J., Frystyk, H.,
Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed., Masinter, L., Leach, P., Berners-Lee, T., Lafon, Y., Ed.,
and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional and J. Reschke, Ed., "HTTP/1.1, part 4: Conditional
Requests", draft-ietf-httpbis-p4-conditional-11 (work in Requests", draft-ietf-httpbis-p4-conditional-12 (work in
progress), August 2010. progress), October 2010.
[RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail [RFC2046] Freed, N. and N. Borenstein, "Multipurpose Internet Mail
Extensions (MIME) Part Two: Media Types", RFC 2046, Extensions (MIME) Part Two: Media Types", RFC 2046,
November 1996. November 1996.
[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.
[RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax [RFC5234] Crocker, D., Ed. and P. Overell, "Augmented BNF for Syntax
Specifications: ABNF", STD 68, RFC 5234, January 2008. Specifications: ABNF", STD 68, RFC 5234, January 2008.
skipping to change at page 21, line 35 skipping to change at page 20, line 35
ABNF diagnostics: ABNF diagnostics:
; Accept-Ranges defined but not used ; Accept-Ranges defined but not used
; Content-Range defined but not used ; Content-Range defined but not used
; If-Range defined but not used ; If-Range defined but not used
; Range defined but not used ; Range defined but not used
Appendix D. Change Log (to be removed by RFC Editor before publication) Appendix D. Change Log (to be removed by RFC Editor before publication)
D.1. Since RFC2616 D.1. Since RFC 2616
Extracted relevant partitions from [RFC2616]. Extracted relevant partitions from [RFC2616].
D.2. Since draft-ietf-httpbis-p5-range-00 D.2. Since draft-ietf-httpbis-p5-range-00
Closed issues: Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/18>: "Cache o <http://tools.ietf.org/wg/httpbis/trac/ticket/18>: "Cache
validators in 206 responses" validators in 206 responses"
(<http://purl.org/NET/http-errata#ifrange206>) (<http://purl.org/NET/http-errata#ifrange206>)
skipping to change at page 22, line 20 skipping to change at page 21, line 20
RFC4288" RFC4288"
Ongoing work on ABNF conversion Ongoing work on ABNF conversion
(<http://tools.ietf.org/wg/httpbis/trac/ticket/36>): (<http://tools.ietf.org/wg/httpbis/trac/ticket/36>):
o Add explicit references to BNF syntax and rules imported from o Add explicit references to BNF syntax and rules imported from
other parts of the specification. other parts of the specification.
D.4. Since draft-ietf-httpbis-p5-range-02 D.4. Since draft-ietf-httpbis-p5-range-02
Ongoing work on IANA Message Header Registration Ongoing work on IANA Message Header Field Registration
(<http://tools.ietf.org/wg/httpbis/trac/ticket/40>): (<http://tools.ietf.org/wg/httpbis/trac/ticket/40>):
o Reference RFC 3984, and update header registrations for headers o Reference RFC 3984, and update header field registrations for
defined in this document. headers defined in this document.
D.5. Since draft-ietf-httpbis-p5-range-03 D.5. Since draft-ietf-httpbis-p5-range-03
D.6. Since draft-ietf-httpbis-p5-range-04 D.6. Since draft-ietf-httpbis-p5-range-04
Closed issues: Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/133>: "multipart/ o <http://tools.ietf.org/wg/httpbis/trac/ticket/133>: "multipart/
byteranges minimum number of parts" byteranges minimum number of parts"
Ongoing work on ABNF conversion Ongoing work on ABNF conversion
(<http://tools.ietf.org/wg/httpbis/trac/ticket/36>): (<http://tools.ietf.org/wg/httpbis/trac/ticket/36>):
o Use "/" instead of "|" for alternatives. o Use "/" instead of "|" for alternatives.
o Introduce new ABNF rules for "bad" whitespace ("BWS"), optional o Introduce new ABNF rules for "bad" whitespace ("BWS"), optional
whitespace ("OWS") and required whitespace ("RWS"). whitespace ("OWS") and required whitespace ("RWS").
o Rewrite ABNFs to spell out whitespace rules, factor out header o Rewrite ABNFs to spell out whitespace rules, factor out header
value format definitions. field value format definitions.
D.7. Since draft-ietf-httpbis-p5-range-05 D.7. Since draft-ietf-httpbis-p5-range-05
Closed issues: Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/142>: "State base o <http://tools.ietf.org/wg/httpbis/trac/ticket/142>: "State base
for *-byte-pos and suffix-length" for *-byte-pos and suffix-length"
Ongoing work on Custom Ranges Ongoing work on Custom Ranges
(<http://tools.ietf.org/wg/httpbis/trac/ticket/85>): (<http://tools.ietf.org/wg/httpbis/trac/ticket/85>):
skipping to change at page 24, line 16 skipping to change at page 23, line 16
entity / representation / variant terminology" entity / representation / variant terminology"
o <http://tools.ietf.org/wg/httpbis/trac/ticket/220>: "consider o <http://tools.ietf.org/wg/httpbis/trac/ticket/220>: "consider
removing the 'changes from 2068' sections" removing the 'changes from 2068' sections"
Ongoing work on Custom Ranges Ongoing work on Custom Ranges
(<http://tools.ietf.org/wg/httpbis/trac/ticket/85>): (<http://tools.ietf.org/wg/httpbis/trac/ticket/85>):
o Add IANA registry. o Add IANA registry.
D.13. Since draft-ietf-httpbis-p5-range-11
Closed issues:
o <http://tools.ietf.org/wg/httpbis/trac/ticket/217>: "Caches can't
be required to serve ranges"
Index Index
2 2
206 Partial Content (status code) 7 206 Partial Content (status code) 6
4 4
416 Requested Range Not Satisfiable (status code) 8 416 Requested Range Not Satisfiable (status code) 7
A A
Accept-Ranges header 9 Accept-Ranges header 8
C C
Content-Range header 9 Content-Range header 8
G G
Grammar Grammar
Accept-Ranges 9 Accept-Ranges 8
Accept-Ranges-v 9 Accept-Ranges-v 8
acceptable-ranges 9 acceptable-ranges 8
byte-content-range-spec 9 byte-content-range-spec 8
byte-range-resp-spec 9 byte-range-resp-spec 8
byte-range-set 12 byte-range-set 11
byte-range-spec 12 byte-range-spec 11
byte-ranges-specifier 12 byte-ranges-specifier 11
bytes-unit 6 bytes-unit 5
Content-Range 9 Content-Range 8
content-range-spec 9 content-range-spec 8
Content-Range-v 9 Content-Range-v 8
first-byte-pos 12 first-byte-pos 11
If-Range 12 If-Range 11
If-Range-v 12 If-Range-v 11
instance-length 9 instance-length 8
last-byte-pos 12 last-byte-pos 11
other-range-unit 6 other-range-unit 5
Range 14 Range 13
range-unit 6 range-unit 5
ranges-specifier 12 ranges-specifier 11
suffix-byte-range-spec 13 suffix-byte-range-spec 12
suffix-length 13 suffix-length 12
H H
Headers Headers
Accept-Ranges 9 Accept-Ranges 8
Content-Range 9 Content-Range 8
If-Range 11 If-Range 10
Range 12 Range 11
I I
If-Range header 11 If-Range header 10
M M
Media Type Media Type
multipart/byteranges 17 multipart/byteranges 16
multipart/x-byteranges 20 multipart/x-byteranges 19
multipart/byteranges Media Type 17 multipart/byteranges Media Type 16
multipart/x-byteranges Media Type 20 multipart/x-byteranges Media Type 19
R R
Range header 12 Range header 11
S S
Status Codes Status Codes
206 Partial Content 7 206 Partial Content 6
416 Requested Range Not Satisfiable 8 416 Requested Range Not Satisfiable 7
Authors' Addresses Authors' Addresses
Roy T. Fielding (editor) Roy T. Fielding (editor)
Day Software Day Software
23 Corporate Plaza DR, Suite 280 23 Corporate Plaza DR, Suite 280
Newport Beach, CA 92660 Newport Beach, CA 92660
USA USA
Phone: +1-949-706-5300 Phone: +1-949-706-5300
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