[sslh] Better --transparent way on Linux

[Yves Rutschle]

Hello everyone,

On Sat, Nov 02, 2019 at 08:55:27PM +0000, Yves Rutschle wrote:
> Thanks for the new rules and comments... I'll try and
> integrate this into the existing documentation, but I think
> I need to re-organise it if we don't want to have things
> scattered all over...


See new interesting information here:
https://github.com/yrutschle/sslh/issues/252#issuecomment-576224387
which indicates adding docker is yet another setup.

So now my thinking is to make 4 chapters:

- sslh and target service on same host
  => Achieved with the simple rules

- sslh and target service on different hosts
  => achieved with Sean Warner's setup (currently documented
  in https://github.com/yrutschle/sslh/blob/master/doc/tproxy.md)

- sslh on main host and target in a docker on the same host
- sslh in a docker targeting a different docker
  => No known working setup at this point

This is all complicated by the fact that for some reason my
VPS does not seem to support transparent proxying
(setsockopt IP_TRANSPARENT fails...) so I can't test
anything :/

Y.