stockholm/tv/3modules/iptables.nix

178 lines
4.8 KiB
Nix

{ config, lib, pkgs, ... }:
with import <stockholm/lib>;
let {
cfg = config.tv.iptables;
body = {
options.tv.iptables = api;
config = lib.mkIf cfg.enable imp;
};
extraTypes = {
rules = types.submodule {
options = {
nat.OUTPUT = mkOption {
type = with types; listOf str;
default = [];
};
nat.PREROUTING = mkOption {
type = with types; listOf str;
default = [];
};
nat.POSTROUTING = mkOption {
type = with types; listOf str;
default = [];
};
filter.FORWARD = mkOption {
type = with types; listOf str;
default = [];
};
filter.INPUT = mkOption {
type = with types; listOf str;
default = [];
};
filter.Retiolum = mkOption {
type = with types; listOf str;
default = [];
};
};
};
};
api = {
enable = mkEnableOption "tv.iptables";
accept-echo-request = mkOption {
type = with types; nullOr (enum ["internet" "retiolum"]);
default = "retiolum";
};
input-internet-accept-tcp = mkOption {
type = with types; listOf (either int str);
default = [];
};
input-internet-accept-udp = mkOption {
type = with types; listOf (either int str);
default = [];
};
input-retiolum-accept-tcp = mkOption {
type = with types; listOf (either int str);
default = [];
};
input-retiolum-accept-udp = mkOption {
type = with types; listOf (either int str);
default = [];
};
extra = mkOption {
default = {};
type = extraTypes.rules;
};
extra4 = mkOption {
default = {};
type = extraTypes.rules;
};
extra6 = mkOption {
default = {};
type = extraTypes.rules;
};
};
imp = {
networking.firewall.enable = false;
systemd.services.tv-iptables = {
wantedBy = [ "sysinit.target" ];
wants = [ "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";
SyslogIdentifier = "tv-iptables_start";
ExecStart = pkgs.writeDash "tv-iptables_start" ''
set -euf
iptables-restore < ${rules 4}
ip6tables-restore < ${rules 6}
'';
};
unitConfig.DefaultDependencies = false;
};
};
formatTable = table:
(concatStringsSep "\n"
(mapAttrsToList
(chain: concatMapStringsSep "\n" (rule: "-A ${chain} ${rule}"))
table));
rules = iptables-version: let
accept-echo-request = {
ip4tables = "-p icmp -m icmp --icmp-type echo-request -j ACCEPT";
ip6tables = "-p ipv6-icmp -m icmp6 --icmpv6-type echo-request -j ACCEPT";
}."ip${toString iptables-version}tables";
accept-tcp = port: "-p tcp -m tcp --dport ${port} -j ACCEPT";
accept-udp = port: "-p udp -m udp --dport ${port} -j ACCEPT";
in
pkgs.writeText "tv-iptables-rules${toString iptables-version}" ''
*nat
:PREROUTING ACCEPT [0:0]
:INPUT ACCEPT [0:0]
:OUTPUT ACCEPT [0:0]
:POSTROUTING ACCEPT [0:0]
${formatTable cfg."extra${toString iptables-version}".nat}
${formatTable cfg.extra.nat}
COMMIT
*filter
:INPUT DROP [0:0]
:FORWARD DROP [0:0]
:OUTPUT ACCEPT [0:0]
:Retiolum - [0:0]
${concatMapStringsSep "\n" (rule: "-A INPUT ${rule}") ([]
++ [
"-m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT"
"-i lo -j ACCEPT"
]
++ optional (cfg.accept-echo-request == "internet") accept-echo-request
++ map accept-tcp (unique (map toString cfg.input-internet-accept-tcp))
++ map accept-udp (unique (map toString cfg.input-internet-accept-udp))
++ ["-i retiolum -j Retiolum"]
)}
${formatTable cfg.extra.filter}
${formatTable cfg."extra${toString iptables-version}".filter}
${concatMapStringsSep "\n" (rule: "-A Retiolum ${rule}") ([]
++ optional (cfg.accept-echo-request == "retiolum") accept-echo-request
++ map accept-tcp (unique (map toString cfg.input-retiolum-accept-tcp))
++ map accept-udp (unique (map toString cfg.input-retiolum-accept-udp))
++ {
ip4tables = [
"-p tcp -j REJECT --reject-with tcp-reset"
"-p udp -j REJECT --reject-with icmp-port-unreachable"
"-j REJECT --reject-with icmp-proto-unreachable"
];
ip6tables = [
"-p tcp -j REJECT --reject-with tcp-reset"
"-p udp -j REJECT --reject-with icmp6-port-unreachable"
"-j REJECT"
];
}."ip${toString iptables-version}tables"
)}
COMMIT
'';
}