From 1078d1a8a3f4f17f20fa81c76f9af39fc844e801 Mon Sep 17 00:00:00 2001 From: lassulus Date: Thu, 1 Oct 2015 22:10:21 +0200 Subject: move iptables.nix to krebs --- krebs/3modules/iptables.nix | 186 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 186 insertions(+) create mode 100644 krebs/3modules/iptables.nix (limited to 'krebs/3modules/iptables.nix') diff --git a/krebs/3modules/iptables.nix b/krebs/3modules/iptables.nix new file mode 100644 index 000000000..9596229de --- /dev/null +++ b/krebs/3modules/iptables.nix @@ -0,0 +1,186 @@ +arg@{ config, lib, pkgs, ... }: + +let + inherit (pkgs) writeScript writeText; + + inherit (builtins) + elem + ; + + inherit (lib) + concatMapStringsSep + concatStringsSep + attrNames + unique + fold + any + attrValues + catAttrs + filter + flatten + length + hasAttr + mkEnableOption + mkOption + mkIf + types + sort + ; + + cfg = config.krebs.iptables; + + out = { + options.krebs.iptables = api; + config = mkIf cfg.enable imp; + }; + + api = { + enable = mkEnableOption "iptables"; + + #tables.filter.INPUT = { + # policy = "DROP"; + # rules = [ + # { predicate = "-i retiolum"; target = "ACCEPT"; priority = -10; } + # ]; + #}; + #new api + tables = mkOption { + type = with types; attrsOf (attrsOf (submodule ({ + options = { + policy = mkOption { + type = str; + default = "-"; + }; + rules = mkOption { + type = nullOr (listOf (submodule ({ + options = { + predicate = mkOption { + type = str; + }; + target = mkOption { + type = str; + }; + precedence = mkOption { + type = int; + default = 0; + }; + }; + }))); + default = null; + }; + }; + }))); + }; + }; + + imp = { + networking.firewall.enable = false; + + systemd.services.krebs-iptables = { + description = "krebs-iptables"; + wantedBy = [ "network-pre.target" ]; + before = [ "network-pre.target" ]; + after = [ "systemd-modules-load.service" ]; + + path = with pkgs; [ + iptables + ]; + + restartIfChanged = true; + + serviceConfig = { + Type = "simple"; + RemainAfterExit = true; + Restart = "always"; + ExecStart = "@${startScript} krebs-iptables_start"; + }; + }; + }; + + #buildTable :: iptablesVersion -> iptablesAttrSet` -> str + #todo: differentiate by iptables-version + buildTables = v: ts: + let + + declareChain = t: cn: + #TODO: find out what to do whit these count numbers + ":${cn} ${t."${cn}".policy} [0:0]"; + + buildChain = tn: cn: + let + sortedRules = sort (a: b: a.precedence > b.precedence) ts."${tn}"."${cn}".rules; + + in + #TODO: double check should be unneccessary, refactor! + if ts.${tn}.${cn}.rules or null != null then + concatMapStringsSep "\n" (rule: "\n-A ${cn} ${rule}") ([] + ++ map (buildRule tn cn) sortedRules + ) + else + "" + ; + + + buildRule = tn: cn: rule: + #target validation test: + assert (elem rule.target ([ "ACCEPT" "REJECT" "DROP" "QUEUE" "LOG" "RETURN" ] ++ (attrNames ts."${tn}"))); + + #predicate validation test: + #maybe use iptables-test + #TODO: howto exit with evaluation error by shellscript? + #apperantly not possible from nix because evalatution wouldn't be deterministic. + "${rule.predicate} -j ${rule.target}"; + + buildTable = tn: + "*${tn}\n" + + concatStringsSep "\n" ([] + ++ map (declareChain ts."${tn}") (attrNames ts."${tn}") + ) + + #this looks dirty, find a better way to do this (maybe optionalString) + concatStringsSep "" ([] + ++ map (buildChain tn) (attrNames ts."${tn}") + ) + + "\nCOMMIT"; + in + concatStringsSep "\n" ([] + ++ map buildTable (attrNames ts) + ); + +#===== + + rules4 = iptables-version: + let + #TODO: find out good defaults. + tables-defaults = { + nat.PREROUTING.policy = "ACCEPT"; + nat.INPUT.policy = "ACCEPT"; + nat.OUTPUT.policy = "ACCEPT"; + nat.POSTROUTING.policy = "ACCEPT"; + filter.INPUT.policy = "ACCEPT"; + filter.FORWARD.policy = "ACCEPT"; + filter.OUTPUT.policy = "ACCEPT"; + + #if someone specifies any other rules on this chain, the default rules get lost. + #is this wanted beahiviour or a bug? + #TODO: implement abstraction of rules + filter.INPUT.rules = [ + { predicate = "-m conntrack --ctstate RELATED,ESTABLISHED"; target = "ACCEPT"; } + ]; + }; + tables = tables-defaults // cfg.tables; + + in + writeText "krebs-iptables-rules${toString iptables-version}" '' + ${buildTables iptables-version tables} + ''; + + startScript = writeScript "krebs-iptables_start" '' + #! /bin/sh + set -euf + iptables-restore < ${rules4 4} + ip6tables-restore < ${rules4 6} + ''; + +in +out + -- cgit v1.2.3