[PATCH] Add proxy_protocol option to mail listener

[Kees Bos]

On za, 2017-08-05 at 20:44 -0400, Wayde Nie wrote:
> Hi Kees, Maxim,
> 
> I'm very interested in proxy_protocol enabled nginx mail proxy as
> well.
> Wondering if the feature might be more straightforward (initially?)
> if,
> when enabled on the listen line, it simply set the appropriate
> $proxy_protocol_* variables, similar to the http servers?
> 
> I was hoping that I could then include it as an http get param in the
> url for my auth_http directive for the auth script to do a dns
> blacklist
> lookup and/or logging (and possibly some other anti spambot efforts).
> 
> I'm working on it with your patch as a starting point, and I can get
> it
> to compile cleanly.  Nginx keeps working as expected when I don't set
> proxy_protocol on the listen directive, and when I do set
> proxy_protocol
> on the listen directive I see the correct ip and port picked up and
> logged in the error.log, however, then nginx stops sending the smtp
> greeting... My mail client connects to my loadbalancer, the lb
> connects
> to nginx:587 sending the PROXY line, nginx parses and logs the PROXY
> fields,  then the client times out waiting for any return traffic
> from
> nginx... I know it's something I'm doing :-)
> 
> I'm happy to keep poking away at it, but curious mostly, if you think
> the approach is sound? (ie. use $proxy_protocol_addr, set by
> proxy_protocol directive and pass in to auth_http script in auth url
> as
> a get param?) and if an initial patch that starts by just setting
> $proxy_protocol_* variables would be a useful first step in this type
> of
> functionality?
> 
> Thanks! Wayde.

Just to get the picture right (it looks to me that your downstream smtp
server expects the proxy protocol), what's the exact flow you're trying
to accomplish?