issues with IPv6 listening sockets and send-proxy

[Björn Jacke]

Hi,

I recently ran into the problem, that using "send-proxy" with Apache's 
mod_remoteip and RemoteIPProxyProtocol on fails for all IPv4 addresses. 
The main problem is mod_remoteup, which doesn't accept IPv4-mapped IPv6 
addresses. I've reported that bug in 
https://bz.apache.org/bugzilla/show_bug.cgi?id=69672 and hope that this 
will get fixed.

Of course you can work around the problem by not listening on  ":::443" 
for both IPv6 and IPv4 at the same time but use "v6only" and listen on 
"*:443" separately.

People might argue however, that it's not ideal to report IPv4-mapped 
IPv6 addresses via the proxy protocol. You might consider to change 
haproxy here, too, so that IPv4 addresses are reported, even if the 
incoming address technically was a IPv4-mapped IPv6 address. I would 
prefer that actually.

Let me know if you want this as a bug report to track this as an issue 
for haproxy.

Björn