networks: implement bssid support

nix/networks/list.nix

@@ -6,6 +6,7 @@ in
 [
   {
     ssid = "~";
+    bssid = "de:ad:de:ad:d0:d0"; # dead dead dodo
     priority = preferredPriority;
     hasPassword = true;
   }

nix/networks/wpa_supplicant-compat.nix

@@ -13,23 +13,27 @@ let
   go =
     networkArgs@{
       ssid,
+      bssid ? null,
       # Custom fields wrapping nixpkgs module options
       hasPassword ? false,
       scanOnLowSignal ? false,
       randomizeMac ? false,
       ...
     }:
+    let
+      uniqueKey = "${ssid}${lib.optionalString (bssid != null) bssid}";
+    in
     {
-      ${ssid} = lib.mkMerge [
+      ${uniqueKey} # we use a unique key here to make sure no "same ssid different bssid" networks collide in key.
+        =
+          lib.mkMerge [
             (builtins.removeAttrs networkArgs [
-          # We keep ssid, because it overrides the attrset name ssid
-          # "ssid"
               "hasPassword"
               "scanOnLowSignal"
               "randomizeMac"
             ])
             (lib.optionalAttrs hasPassword {
-          pskRaw = "ext:${escapePwdKey ssid}";
+              pskRaw = "ext:${escapePwdKey uniqueKey}"; # this implies changing the external password key if you set a bssid!
             })
             {
               extraConfig = ''