rfc2068.txt

本书源码主要针对目前流行的FTP、HTTP、E-mail、Telnet、ICMP、Modem串口通信编程、拨号网络编程等内容进行详细的讲解

Network Working Group                                      R. Fielding
Request for Comments: 2068                                   UC Irvine
Category: Standards Track                                    J. Gettys
                                                              J. Mogul
                                                                   DEC
                                                            H. Frystyk
                                                        T. Berners-Lee
                                                               MIT/LCS
                                                          January 1997


                Hypertext Transfer Protocol -- HTTP/1.1

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Abstract

   The Hypertext Transfer Protocol (HTTP) is an application-level
   protocol for distributed, collaborative, hypermedia information
   systems. It is a generic, stateless, object-oriented protocol which
   can be used for many tasks, such as name servers and distributed
   object management systems, through extension of its request methods.
   A feature of HTTP is the typing and negotiation of data
   representation, allowing systems to be built independently of the
   data being transferred.

   HTTP has been in use by the World-Wide Web global information
   initiative since 1990. This specification defines the protocol
   referred to as "HTTP/1.1".

Table of Contents

   1 Introduction.............................................7
    1.1 Purpose ..............................................7
    1.2 Requirements .........................................7
    1.3 Terminology ..........................................8
    1.4 Overall Operation ...................................11
   2 Notational Conventions and Generic Grammar..............13
    2.1 Augmented BNF .......................................13
    2.2 Basic Rules .........................................15
   3 Protocol Parameters.....................................17
    3.1 HTTP Version ........................................17



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    3.2 Uniform Resource Identifiers ........................18
     3.2.1 General Syntax ...................................18
     3.2.2 http URL .........................................19
     3.2.3 URI Comparison ...................................20
    3.3 Date/Time Formats ...................................21
     3.3.1 Full Date ........................................21
     3.3.2 Delta Seconds ....................................22
    3.4 Character Sets ......................................22
    3.5 Content Codings .....................................23
    3.6 Transfer Codings ....................................24
    3.7 Media Types .........................................25
     3.7.1 Canonicalization and Text Defaults ...............26
     3.7.2 Multipart Types ..................................27
    3.8 Product Tokens ......................................28
    3.9 Quality Values ......................................28
    3.10 Language Tags ......................................28
    3.11 Entity Tags ........................................29
    3.12 Range Units ........................................30
   4 HTTP Message............................................30
    4.1 Message Types .......................................30
    4.2 Message Headers .....................................31
    4.3 Message Body ........................................32
    4.4 Message Length ......................................32
    4.5 General Header Fields ...............................34
   5 Request.................................................34
    5.1 Request-Line ........................................34
     5.1.1 Method ...........................................35
     5.1.2 Request-URI ......................................35
    5.2 The Resource Identified by a Request ................37
    5.3 Request Header Fields ...............................37
   6 Response................................................38
    6.1 Status-Line .........................................38
     6.1.1 Status Code and Reason Phrase ....................39
    6.2 Response Header Fields ..............................41
   7 Entity..................................................41
    7.1 Entity Header Fields ................................41
    7.2 Entity Body .........................................42
     7.2.1 Type .............................................42
     7.2.2 Length ...........................................43
   8 Connections.............................................43
    8.1 Persistent Connections ..............................43
     8.1.1 Purpose ..........................................43
     8.1.2 Overall Operation ................................44
     8.1.3 Proxy Servers ....................................45
     8.1.4 Practical Considerations .........................45
    8.2 Message Transmission Requirements ...................46
   9 Method Definitions......................................48
    9.1 Safe and Idempotent Methods .........................48



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     9.1.1 Safe Methods .....................................48
     9.1.2 Idempotent Methods ...............................49
    9.2 OPTIONS .............................................49
    9.3 GET .................................................50
    9.4 HEAD ................................................50
    9.5 POST ................................................51
    9.6 PUT .................................................52
    9.7 DELETE ..............................................53
    9.8 TRACE ...............................................53
   10 Status Code Definitions................................53
    10.1 Informational 1xx ..................................54
     10.1.1 100 Continue ....................................54
     10.1.2 101 Switching Protocols .........................54
    10.2 Successful 2xx .....................................54
     10.2.1 200 OK ..........................................54
     10.2.2 201 Created .....................................55
     10.2.3 202 Accepted ....................................55
     10.2.4 203 Non-Authoritative Information ...............55
     10.2.5 204 No Content ..................................55
     10.2.6 205 Reset Content ...............................56
     10.2.7 206 Partial Content .............................56
    10.3 Redirection 3xx ....................................56
     10.3.1 300 Multiple Choices ............................57
     10.3.2 301 Moved Permanently ...........................57
     10.3.3 302 Moved Temporarily ...........................58
     10.3.4 303 See Other ...................................58
     10.3.5 304 Not Modified ................................58
     10.3.6 305 Use Proxy ...................................59
    10.4 Client Error 4xx ...................................59
     10.4.1 400 Bad Request .................................60
     10.4.2 401 Unauthorized ................................60
     10.4.3 402 Payment Required ............................60
     10.4.4 403 Forbidden ...................................60
     10.4.5 404 Not Found ...................................60
     10.4.6 405 Method Not Allowed ..........................61
     10.4.7 406 Not Acceptable ..............................61
     10.4.8 407 Proxy Authentication Required ...............61
     10.4.9 408 Request Timeout .............................62
     10.4.10 409 Conflict ...................................62
     10.4.11 410 Gone .......................................62
     10.4.12 411 Length Required ............................63
     10.4.13 412 Precondition Failed ........................63
     10.4.14 413 Request Entity Too Large ...................63
     10.4.15 414 Request-URI Too Long .......................63
     10.4.16 415 Unsupported Media Type .....................63
    10.5 Server Error 5xx ...................................64
     10.5.1 500 Internal Server Error .......................64
     10.5.2 501 Not Implemented .............................64



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     10.5.3 502 Bad Gateway .................................64
     10.5.4 503 Service Unavailable .........................64
     10.5.5 504 Gateway Timeout .............................64
     10.5.6 505 HTTP Version Not Supported ..................65
   11 Access Authentication..................................65
    11.1 Basic Authentication Scheme ........................66
    11.2 Digest Authentication Scheme .......................67
   12 Content Negotiation....................................67
    12.1 Server-driven Negotiation ..........................68
    12.2 Agent-driven Negotiation ...........................69
    12.3 Transparent Negotiation ............................70
   13 Caching in HTTP........................................70
     13.1.1 Cache Correctness ...............................72
     13.1.2 Warnings ........................................73
     13.1.3 Cache-control Mechanisms ........................74
     13.1.4 Explicit User Agent Warnings ....................74
     13.1.5 Exceptions to the Rules and Warnings ............75
     13.1.6 Client-controlled Behavior ......................75
    13.2 Expiration Model ...................................75
     13.2.1 Server-Specified Expiration .....................75
     13.2.2 Heuristic Expiration ............................76
     13.2.3 Age Calculations ................................77
     13.2.4 Expiration Calculations .........................79
     13.2.5 Disambiguating Expiration Values ................80
     13.2.6 Disambiguating Multiple Responses ...............80
    13.3 Validation Model ...................................81
     13.3.1 Last-modified Dates .............................82
     13.3.2 Entity Tag Cache Validators .....................82
     13.3.3 Weak and Strong Validators ......................82
     13.3.4 Rules for When to Use Entity Tags and Last-
     modified Dates..........................................85
     13.3.5 Non-validating Conditionals .....................86
    13.4 Response Cachability ...............................86
    13.5 Constructing Responses From Caches .................87
     13.5.1 End-to-end and Hop-by-hop Headers ...............88
     13.5.2 Non-modifiable Headers ..........................88
     13.5.3 Combining Headers ...............................89
     13.5.4 Combining Byte Ranges ...........................90
    13.6 Caching Negotiated Responses .......................90
    13.7 Shared and Non-Shared Caches .......................91
    13.8 Errors or Incomplete Response Cache Behavior .......91
    13.9 Side Effects of GET and HEAD .......................92
    13.10 Invalidation After Updates or Deletions ...........92
    13.11 Write-Through Mandatory ...........................93
    13.12 Cache Replacement .................................93
    13.13 History Lists .....................................93
   14 Header Field Definitions...............................94
    14.1 Accept .............................................95



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    14.2 Accept-Charset .....................................97
    14.3 Accept-Encoding ....................................97
    14.4 Accept-Language ....................................98
    14.5 Accept-Ranges ......................................99
    14.6 Age ................................................99
    14.7 Allow .............................................100
    14.8 Authorization .....................................100
    14.9 Cache-Control .....................................101
     14.9.1 What is Cachable ...............................103
     14.9.2 What May be Stored by Caches ...................103
     14.9.3 Modifications of the Basic Expiration Mechanism 104
     14.9.4 Cache Revalidation and Reload Controls .........105
     14.9.5 No-Transform Directive .........................107
     14.9.6 Cache Control Extensions .......................108
    14.10 Connection .......................................109
    14.11 Content-Base .....................................109
    14.12 Content-Encoding .................................110
    14.13 Content-Language .................................110
    14.14 Content-Length ...................................111
    14.15 Content-Location .................................112
    14.16 Content-MD5 ......................................113
    14.17 Content-Range ....................................114
    14.18 Content-Type .....................................116
    14.19 Date .............................................116
    14.20 ETag .............................................117
    14.21 Expires ..........................................117
    14.22 From .............................................118
    14.23 Host .............................................119
    14.24 If-Modified-Since ................................119
    14.25 If-Match .........................................121
    14.26 If-None-Match ....................................122
    14.27 If-Range .........................................123
    14.28 If-Unmodified-Since ..............................124
    14.29 Last-Modified ....................................124
    14.30 Location .........................................125
    14.31 Max-Forwards .....................................125
    14.32 Pragma ...........................................126
    14.33 Proxy-Authenticate ...............................127
    14.34 Proxy-Authorization ..............................127
    14.35 Public ...........................................127
    14.36 Range ............................................128
     14.36.1 Byte Ranges ...................................128
     14.36.2 Range Retrieval Requests ......................130
    14.37 Referer ..........................................131
    14.38 Retry-After ......................................131
    14.39 Server ...........................................132
    14.40 Transfer-Encoding ................................132
    14.41 Upgrade ..........................................132



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    14.42 User-Agent .......................................134
    14.43 Vary .............................................134
    14.44 Via ..............................................135
    14.45 Warning ..........................................137
    14.46 WWW-Authenticate .................................139
   15 Security Considerations...............................139
    15.1 Authentication of Clients .........................139
    15.2 Offering a Choice of Authentication Schemes .......140