[TYPO3-core] RFC: Fix bug #7397: Proxy servers replace REMOTE_ADDR with their own IP

[Martin Kutschker]

Dmitry Dulepov [typo3] schrieb:
> Hi!
> 
> Michael Stucki wrote:
>> Problem:
>> When requesting the clients REMOTE_ADDR, it can happen that there is a 
>> proxy
>> in between server and client, which replaces the value with his own 
>> IP, and
>> puts the original IP in HTTP_X_FORWARDED_FOR instead.
>>
>> Solution:
>> Add a new configuration option to send HTTP_X_FORWARDED_FOR when 
>> requesting
>> the REMOTE_ADDR.
> 
> There is a problem with the patch. Some proxies are configured to reveal 
> themselves but not show IP address of the user. They send 
> HTTP_X_FORWARDED_FOR with value "unknown". So your patch will given 
> invalid IP address. Some proxies are chained and they return two or more 
> addresses (like "192.168.0.23, 10.10.10.5") and it is impossible to 
> determine which address really belongs to cleint. Also will not produce 
> proper output with your patch.

I'll try to take your comments into account when I make my own patch. 
Some concerns of yours are addressed already, I'll check the others as well.

Masi