Switching on snappy compression from a config file fails

[Samuli Seppänen]

Adapted from James' description:

"There is still one issue that I haven't solved with snappy patch in 2.1. When running in server mode, the patch works fine if per-client-session compression parameters are set via client-connect script or management interface, however the patch fails if they are hardcoded into config file."

This ticket can be fixed after porting of 2.1.x-only patches to master has been finished.

[Samuli Seppänen]

More info from James:

There's one issue I've seen in the Snappy implementation in 2.1.  There 
are two locations in init.c with code that resets the compression context.

dest->c2.comp_context = NULL;

This code works fine with the AS because it always uses explicit 
"client-connect" directives to set up the compression parameters for a 
given client instance object, so there's no need to inherit compression 
directives from the main config.  But I realized later, when I tried to 
run a standalone OpenVPN server using a standard config file, without 
the AS, and without a client-connect script, that those lines cause 
compression directives in the config file to fail to propagate to the 
client instance object.

[Gert Döring]

Actually, it's even worse - not only "switching on snappy from config file" fails but also "any compression" - I have "comp-lzo" set in my server config, and upon client connect it seems to fall down to "no compression"...

"compress <anything>" in ccd/client.conf works fine.

OTOH with the hints from James this should be fairly easy to spot now... just need to understand the flow of compression configuration through the code.

[Gert Döring]

patch seems trivial, maybe I'm overlooking something. mailed james, asked for review

[Gert Döring]

commited to git. will send to list tomorrow.

[Gert Döring]

committed to master, as commit 1690f290f4bd2b203634e8fef9a82f7a03e5b06b