1 files changed, 126 insertions, 0 deletions
diff --git a/tv/modules/iptables.nix b/tv/modules/iptables.nix
new file mode 100644
index 0000000..cbf49f5
--- /dev/null
+++ b/tv/modules/iptables.nix
@@ -0,0 +1,126 @@
+{ config, lib, pkgs, ... }:
+
+with builtins;
+with lib;
+let
+  cfg = config.tv.iptables;
+
+  out = {
+    options.tv.iptables = api;
+    config = mkIf cfg.enable imp;
+  };
+
+  api = {
+    enable = mkEnableOption "tv.iptables";
+
+    input-internet-accept-new-tcp = mkOption {
+      type = with types; listOf (either int str);
+      default = [];
+    };
+
+    input-retiolum-accept-new-tcp = mkOption {
+      type = with types; listOf (either int str);
+      default = [];
+    };
+  };
+
+  imp = {
+    networking.firewall.enable = false;
+
+    systemd.services.tv-iptables = {
+      description = "tv-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} tv-iptables_start";
+      };
+    };
+  };
+
+
+  accept-new-tcp = port:
+    "-p tcp -m tcp --dport ${port} -m conntrack --ctstate NEW -j ACCEPT";
+
+  rules = iptables-version:
+    pkgs.writeText "tv-iptables-rules${toString iptables-version}" ''
+      *nat
+      :PREROUTING ACCEPT [0:0]
+      :INPUT ACCEPT [0:0]
+      :OUTPUT ACCEPT [0:0]
+      :POSTROUTING ACCEPT [0:0]
+      ${concatMapStringsSep "\n" (rule: "-A PREROUTING ${rule}") ([]
+        ++ [
+          "! -i retiolum -p tcp -m tcp --dport 22 -j REDIRECT --to-ports 0"
+          "-p tcp -m tcp --dport 11423 -j REDIRECT --to-ports 22"
+        ]
+      )}
+      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"
+        ]
+        ++ map accept-new-tcp (unique (map toString cfg.input-internet-accept-new-tcp))
+        ++ ["-i retiolum -j Retiolum"]
+      )}
+      ${concatMapStringsSep "\n" (rule: "-A Retiolum ${rule}") ([]
+        ++ {
+          ip4tables = [
+            "-p icmp -m icmp --icmp-type echo-request -j ACCEPT"
+          ];
+          ip6tables = [
+            "-p ipv6-icmp -m icmp6 --icmpv6-type echo-request -j ACCEPT"
+          ];
+        }."ip${toString iptables-version}tables"
+        ++ map accept-new-tcp (unique (map toString cfg.input-retiolum-accept-new-tcp))
+        ++ {
+          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
+    '';
+
+  startScript = pkgs.writeScript "tv-iptables_start" ''
+    #! /bin/sh
+    set -euf
+    iptables-restore < ${rules 4}
+    ip6tables-restore < ${rules 6}
+  '';
+
+in
+out
+
+#let
+#  cfg = config.tv.iptables;
+#  arg' = arg // { inherit cfg; };
+#in
+#
+#{
+#  options.tv.iptables = import ./options.nix arg';
+#  config = lib.mkIf cfg.enable (import ./config.nix arg');
+#}