Files
nixos/module.firewall.nix
2026-07-28 01:49:17 -04:00

57 lines
1.7 KiB
Nix

# firewall-rules.nix
{ config, lib, ... }:
with lib;
let
cfg = config.networking.firewall.restrictedPorts;
ruleOpts = { name, ... }: {
options = {
name = mkOption {
type = types.str;
default = name;
description = "Name of the firewall rule.";
};
port = mkOption {
# Allow either an integer port (80) or a string range/list ("8000-8010" or "{ 80, 443 }")
type = types.oneOf [ types.port types.str ];
description = "Target port, port range (e.g. \"8000-8010\"), or list.";
};
protocol = mkOption {
type = types.enum [ "tcp" "udp" ];
default = "tcp";
description = "Transport protocol (tcp or udp).";
};
allowedCIDRs = mkOption {
type = types.listOf types.str;
default = [ "0.0.0.0/0" "::/0" ];
description = "Allowed source CIDRs. Defaults to all IPv4 and IPv6 if omitted.";
};
};
};
formatCidrRule = rule: cidr:
let
family = if hasInfix ":" cidr then "ip6" else "ip";
# toString handles both integers (2222) and strings ("8000-8010") cleanly
portStr = toString rule.port;
in
"${family} saddr ${cidr} ${rule.protocol} dport ${portStr} accept comment \"${rule.name}\"";
formatRule = ruleName: rule:
concatMapStringsSep "\n" (formatCidrRule rule) rule.allowedCIDRs;
in {
options.networking.firewall.restrictedPorts = mkOption {
type = types.attrsOf (types.submodule ruleOpts);
default = { };
description = "Declarative map of named firewall rules.";
};
config = mkIf (cfg != { }) {
networking.firewall.extraInputRules =
concatMapStringsSep "\n" (ruleName: formatRule ruleName cfg.${ruleName}) (attrNames cfg);
};
}