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DOC: minor updates to the proxy protocol doc

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Update the release data, revision history and the link to the Forwarded
HTTP extension.
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Willy Tarreau 2014-06-14 11:45:09 +02:00
parent 01320c9a34
commit 7a6f134121
1 changed files with 12 additions and 9 deletions
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doc/proxy-protocol.txt
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@ -1,4 +1,4 @@
2014/05/10 Willy Tarreau
2014/06/14 Willy Tarreau
HAProxy Technologies
The PROXY protocol
Versions 1 & 2
@ -19,6 +19,8 @@ Revision history
2012/06/21 - add support for binary format
2012/11/19 - final review and fixes
2014/05/18 - modify and extend PROXY protocol version 2
2014/06/11 - fix example code to consider ver+cmd merge
2014/06/14 - fix v2 header check in example code, and update Forwarded spec
1. Background
@ -27,11 +29,11 @@ Relaying TCP connections through proxies generally involves a loss of the
original TCP connection parameters such as source and destination addresses,
ports, and so on. Some protocols make it a little bit easier to transfer such
information. For SMTP, Postfix authors have proposed the XCLIENT protocol [1]
which received broad adoption and is particularly suited to mail exchanges. In
HTTP, there is the "Forwarded-For" proposed standard [2]. This proposal aims at
replacing the omnipresent "X-Forwarded-For" header which carries information
about the original source address, and the less common X-Original-To which
carries information about the destination address.
which received broad adoption and is particularly suited to mail exchanges.
For HTTP, there is the "Forwarded" extension [2], which aims at replacing the
omnipresent "X-Forwarded-For" header which carries information about the
original source address, and the less common X-Original-To which carries
information about the destination address.
However, both mechanisms require a knowledge of the underlying protocol to be
implemented in intermediaries.
@ -40,10 +42,11 @@ Then comes a new class of products which we'll call "dumb proxies", not because
they don't do anything, but because they're processing protocol-agnostic data.
Both Stunnel[3] and Stud[4] are examples of such "dumb proxies". They talk raw
TCP on one side, and raw SSL on the other one, and do that reliably, without
any knowledge of what protocol is transported on top of the connection.
any knowledge of what protocol is transported on top of the connection. Haproxy
running in pure TCP mode obviously falls into that category as well.
The problem with such a proxy when it is combined with another one such as
haproxy is to adapt it to talk the higher level protocol. A patch is available
haproxy, is to adapt it to talk the higher level protocol. A patch is available
for Stunnel to make it capable of inserting an X-Forwarded-For header in the
first HTTP request of each incoming connection. Haproxy is able not to add
another one when the connection comes from Stunnel, so that it's possible to
@ -734,7 +737,7 @@ Please use w@1wt.eu to send any comments to the author.
The following links were referenced in the document.
[1] http://www.postfix.org/XCLIENT_README.html
[2] http://tools.ietf.org/html/draft-ietf-appsawg-http-forwarded
[2] http://tools.ietf.org/html/rfc7239
[3] http://www.stunnel.org/
[4] https://github.com/bumptech/stud
[5] https://github.com/bumptech/stud/pull/81