W3C home > Mailing lists > Public > public-tracking@w3.org > November 2011

RE: Headers modified along the way against user (non) choices

From: Kevin Smith <kevsmith@adobe.com>
Date: Fri, 11 Nov 2011 11:48:21 -0800
To: Karl Dubost <karld@opera.com>, "public-tracking@w3.org Group WG" <public-tracking@w3.org>
Message-ID: <6E120BECD1FFF142BC26B61F4D994CF30635CAF023@nambx07.corp.adobe.com>
What would be the objective of echoing the request?  What would we expect the browser to do with the information?  They could warn the user, but in most cases, I doubt the user cares why their DNT preference is being ignored and I would expect both the user and the browser to react exactly the same as if the server simply returned a DNT:0.  At best, the browser could provide the additional information "the site may not be at fault so you may want to try this site on a different network".  This does not seem worth the extra complexity.

The other purpose I can see of echoing the request is trying to determine which proxies or other services were altering the header.  I personally would hate to bloat the specification for debugging purposes.  There has to be a more elegant method for doing this since every new header has experienced the same problem and I am not familiar with any others requiring an echo.

What other benefits could be derived from echoing the request?

-----Original Message-----
From: Karl Dubost [mailto:karld@opera.com] 
Sent: Wednesday, November 09, 2011 11:25 AM
To: public-tracking@w3.org Group WG
Subject: Headers modified along the way against user (non) choices

On the call today, we discussed about user choice on setting the DNT header.
(Thinking out loud, not a strong opinion)

Basically the header sets 

	DNT: 1 

and along the way a proxy modified the header for

	DNT: 0 

the final server knows only the last value and then might not be able to behave according to user choices.

* CGI
  Roy proposed on IRC to have a cgi script on the final server 
  displaying what headers it has received. Issues because it 
  means the user has to understand what is happening. 

* Echo
  another possibility would be having the server sending back 
  in the response a header with the original DNT header. 
  Server sending something like (not the formal syntax)
  DNT-received: 0
  This has issues too. Ian Fette will say too heavy?
  And a proxy can still modify it on the way back too.





-- 
Karl Dubost - http://dev.opera.com/
Developer Relations & Tools, Opera Software
Received on Friday, 11 November 2011 19:49:07 UTC

This archive was generated by hypermail 2.3.1 : Friday, 21 June 2013 10:11:22 UTC