% vim set ft=prolog

% rule(src, dst, proto, port, source(..)).

:- module(firewall, [
    fw_rule/2,
    warning/1,
    retract_all_from/1]).

:- use_module(hosts, [
    router_link/3]).

:- dynamic fw_rule/2.

warning(Msg) :-
    fw_rule(Host, Attr),
    \+ (_{from:_} :< Attr),
    format(string(Msg), "Missing 'from' on fw_rule for host '~w', ~w", [Host, Attr]).

rules_from(From, Rules) :-
    findall(fw_rule(Host, Attr), (fw_rule(Host, Attr), Attr.from=From), Rules).

retract_all_from(From) :-
    rules_from(From, Rules),
    retract_rules(Rules).

retract_rules([R|Rules]) :- retract(R), retract_rules(Rules).
retract_rules([]).