WIP: router: add miniupnpd for automatic port forwarding (e.g. syncthing)

By default, Linux will respond to ARP requests that belong to other interfaces. Normally this isn't a problem, but it causes issues since my WAN and LAN20 are technically bridged.

flake.lock

@@ -7,11 +7,11 @@
         ]
       },
       "locked": {
-        "lastModified": 1742957044,
-        "narHash": "sha256-gwW0tBIA77g6qq45y220drTy0DmThF3fJMwVFUtYV9c=",
+        "lastModified": 1745001336,
+        "narHash": "sha256-R4HuzrgYtOYBNmB3lfRxcieHEBO4uSfgHNz4MzWkZ5M=",
         "owner": "nix-community",
         "repo": "home-manager",
-        "rev": "ce287a5cd3ef78203bc78021447f937a988d9f6f",
+        "rev": "fc09cb7aaadb70d6c4898654ffc872f0d2415df9",
         "type": "github"
       },
       "original": {
@@ -58,11 +58,11 @@
     },
     "nixpkgs": {
       "locked": {
-        "lastModified": 1742669843,
-        "narHash": "sha256-G5n+FOXLXcRx+3hCJ6Rt6ZQyF1zqQ0DL0sWAMn2Nk0w=",
+        "lastModified": 1744932701,
+        "narHash": "sha256-fusHbZCyv126cyArUwwKrLdCkgVAIaa/fQJYFlCEqiU=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "1e5b653dff12029333a6546c11e108ede13052eb",
+        "rev": "b024ced1aac25639f8ca8fdfc2f8c4fbd66c48ef",
         "type": "github"
       },
       "original": {

home/default.nix

@@ -19,6 +19,7 @@ in
     SHELL = "fish";
   };
 
+  # TODO: remove (replace by bitwarden-desktop)
   services.gnome-keyring = {
     enable = true;
     components = [ "pkcs11" "ssh" ];
@@ -161,6 +162,7 @@ in
         shellExpand = true;
       };
       dolphinrc.General.ShowFullPath = true;
+      dolphinrc.DetailsMode.PreviewSize.persistent = true;
       kactivitymanagerdrc = {
         activities."809dc779-bf5b-49e6-8e3f-cbe283cb05b6" = "Default";
         activities."b34a506d-ac4f-4797-8c08-6ef45bc49341" = "Fun";

hosts/Yura-PC/default.nix

@@ -32,7 +32,7 @@
 
   boot.loader.timeout = 3;
   boot.loader.systemd-boot.configurationLimit = 5;
-  boot.kernelPackages = pkgs.linuxKernel.packages.linux_6_12;
+  boot.kernelPackages = pkgs.linuxKernel.packages.linux_6_13;
 
   # https://nixos.wiki/wiki/Accelerated_Video_Playback
   hardware.graphics = {
@@ -125,6 +125,7 @@
 
       # Nix
       nixd
+      nil
 
       # Gleam
       gleam
@@ -237,12 +238,14 @@
     whois
     yt-dlp
   ] ++ [
+    bitwarden-desktop
     darkman
     host-spawn # for flatpaks
     kdePackages.filelight
     kdePackages.flatpak-kcm
     kdePackages.kate
     kdePackages.yakuake
+    # TODO: remove (replace by bitwarden-desktop)
     gcr
     gnome-keyring # config for this and some others
     mpv
@@ -261,6 +264,7 @@
     jetbrains.webstorm
     android-studio
     rustup
+    zed-editor
   ];
 
   # Some programs need SUID wrappers, can be configured further or are

hosts/router/firewall.nix

@@ -20,8 +20,9 @@ in
           ${ifs.lan40.name},
           ${ifs.lan50.name},
       }
-      define OPNSENSE_NET6 = ${pdFromWan}d::/64
+      define OPNSENSE_NET6 = ${vars.extra.opnsense.net6}
       define ZONE_LAN_EXTRA_NET6 = {
+          # TODO: reevaluate this statement
           ${ifs.lan20.net6},  # needed since packets can come in from wan on these addrs
           $OPNSENSE_NET6,
       }
@@ -29,6 +30,7 @@ in
       define CLOUDFLARE_NET6 = {
           # https://www.cloudflare.com/ips-v6
           # TODO: figure out a better way to get addrs dynamically from url
+          # perhaps building a nixos module/package that fetches the ips?
           2400:cb00::/32,
           2606:4700::/32,
           2803:f800::/32,
@@ -125,7 +127,7 @@ in
           meta l4proto . ip6 daddr . th dport @port_forward_v6 accept
 
           # Allowed IPv6 from cloudflare
-          ip6 saddr $CLOUDFLARE_NET6 ip6 daddr @cloudflare_forward_v6 accept
+          ip6 saddr $CLOUDFLARE_NET6 ip6 daddr @cloudflare_forward_v6 th dport https accept
       }
 
       chain zone_lan_input {

hosts/router/ifconfig.nix

@@ -46,6 +46,12 @@ let
   };
 in
 {
+  # By default, Linux will respond to ARP requests that belong to other interfaces.
+  # Normally this isn't a problem, but it causes issues
+  # since my WAN and LAN20 are technically bridged.
+  # https://networkengineering.stackexchange.com/questions/83071/why-linux-answers-arp-requests-for-ips-that-belong-to-different-network-interfac
+  boot.kernel.sysctl."net.ipv4.conf.default.arp_filter" = 1;
+
   # It is impossible to do multiple prefix requests with networkd,
   # so I use dhcpcd for this
   # https://github.com/systemd/systemd/issues/22571
@@ -144,6 +150,7 @@ in
           ifs.lan40.name
           ifs.lan50.name
         ];
+        routes = vars.extra.opnsense.routes;
       };
       "30-vlan10" = mkLanConfig ifs.lan10;
       "30-vlan20" = mkLanConfig ifs.lan20;

hosts/router/services.nix

@@ -4,6 +4,16 @@ let
   domain = vars.domain;
 in
 {
+  services.miniupnpd = {
+    enable = true;
+    natpmp = true;
+    externalInterface = vars.ifs.wan.name;
+    internalIPs = [
+      vars.ifs.lan.name
+      vars.ifs.lan20.name
+    ];
+  };
+
   # https://wiki.nixos.org/wiki/Prometheus
   services.prometheus = {
     enable = true;

hosts/router/vars.nix

@@ -95,4 +95,28 @@ rec {
       ulaPrefix_ = "${ulaPrefix}:0050";  # ::/64
     };
   };
+
+  extra = {
+    opnsense = rec {
+      addr4 = "${ifs.lan.p4}.250";
+      ulaAddr = "${ifs.lan.ulaPrefix}::250";
+      p6 = "${pdFromWan}d";
+      net6 = "${p6}::/64";
+      # VPN routes on opnsense
+      routes = [
+        {
+          Destination = "10.6.0.0/24";
+          Gateway = addr4;
+        }
+        {
+          Destination = "10.18.0.0/20";
+          Gateway = addr4;
+        }
+        {
+          Destination = net6;
+          Gateway = ulaAddr;
+        }
+      ];
+    };
+  };
 }