Hi Eric, On Sun, Mar 29, 2009 at 09:06:40PM -0700, Eric Schwab wrote: > We would like to use x-client with the SMTP protocol with haproxy, as a > means to pass along some basic data to the backend SMTP servers. We > looked into this a month or two ago and Willy mentioned that this would > be substantially easier once 1.3.16/17 was released.
... and now I confirm this ;-) > I know that this could be implemented previously with HTTP - is this now > viable with SMTP? If not, does anybody have the time / inclination / > ability to add this capability? I would be happy to discuss this > off-line as appropriate. I think it is plainly doable now that we can intercept requests and responses for analysis. In fact, I'm even wondering whether we should also support a generic protocol which would work in any mode by prepending a specific line before the payload. This could be used between multiple proxies to make the last one work in transparent mode and connect to the server using the original client's IP. I have some vague memories of some oddities in the XCLIENT protocol, but right now I don't remember which ones. I believe it was the need to let the EHLO line pass first, then check the response, then insert XCLIENT and pass the rest. If an option is provided to force XCLIENT on some servers, we could also simply prepend this line in the request before ever doing the EHLO. I'm not sure whether it works, but the README does not contradict this option. Now, as to who will develop this... I think it's a matter of several hours of work, maybe a full day. I really don't have time right now for this, but maybe there are some persons on the list who can do. Regards, Willy
