IPFW and the IP stack

[Robert Watson]

On Thu, 4 Dec 2003, Devon H.O'Dell wrote:

> This is obviously the most logical explanation. There's a good bit of
> questioning for PFIL_HOOKS to be enabled in generic to allow ipf to be
> loaded as a module as well. If this is the case, we'll have two
> firewalls that have their hooks compiled in by default allowing for them
> both to be loaded as modules. (Is this still scheduled for 5.2?) 
> 
> But at this point, there's no way to allow one to turn the IPFW hooks
> *off*. Is there a reason for this? 
> 
> Would it be beneficial (or possible) to hook ipfw into pfil(9)? This
> way, we could allow the modules to be loaded by default for both and
> also allow for the total absence of both in the kernel. Sorry if I've
> missed discussions on this and am being redundant. 

Sam Leffler has done a substantial amount of work to push all of the
various "hacks"" (features?) behind PFIL_HOOKS, and I anticipate we'll
ship PFIL_HOOKS enabled in GENERIC in 5.3 and use it to plug in most of
these services.  This also means packages like IPFilter and PF will work
"out of the box" without a kernel recompile, not to mention offering
substantial architectural cleanup. 

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Senior Research Scientist, McAfee Research