On Sun, Oct 6, 2019 at 6:49 PM Salvatore Mesoraca
[off-list ref] wrote:

Salvatore Mesoraca [off-list ref] wrote:

quoted

Jann Horn [off-list ref] wrote:

quoted

On Sat, Jul 6, 2019 at 12:55 PM Salvatore Mesoraca
[off-list ref] wrote:

quoted

Creation of a generic Discrete Finite Automata implementation
for string matching. The transition tables have to be produced
in user-space.
This allows us to possibly support advanced string matching
patterns like regular expressions, but they need to be supported
by user-space tools.

AppArmor already has a DFA implementation that takes a DFA machine
from userspace and runs it against file paths; see e.g.
aa_dfa_match(). Did you look into whether you could move their DFA to
some place like lib/ and reuse it instead of adding yet another
generic rule interface to the kernel?

Yes, using AppArmor DFA cloud be a possibility.
Though, I didn't know how AppArmor's maintainers feel about this.
I thought that was easier to just implement my own.
Anyway I understand that re-using that code would be the optimal solution.
I'm adding in CC AppArmor's maintainers, let's see what they think about this.

I don't want this to prevent SARA from being up-streamed.
Do you think that having another DFA here could be acceptable anyway?
Would it be better if I just drop the DFA an go back to simple string
matching to speed up things?

While I think that it would be nicer not to have yet another
implementation of the same thing, I don't feel strongly about it.