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

@@ -13,31 +13,35 @@ 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
     {
-      ${ssid} = lib.mkMerge [
-        (builtins.removeAttrs networkArgs [
-          # We keep ssid, because it overrides the attrset name ssid
-          # "ssid"
-          "hasPassword"
-          "scanOnLowSignal"
-          "randomizeMac"
-        ])
-        (lib.optionalAttrs hasPassword {
-          pskRaw = "ext:${escapePwdKey ssid}";
-        })
-        {
-          extraConfig = ''
-            ${lib.optionalString scanOnLowSignal "bgscan=\"simple:30:-70:3600\""}
-            ${lib.optionalString randomizeMac "mac_addr=1"}
-          '';
-        }
-      ];
+      ${uniqueKey} # we use a unique key here to make sure no "same ssid different bssid" networks collide in key.
+        =
+          lib.mkMerge [
+            (builtins.removeAttrs networkArgs [
+              "hasPassword"
+              "scanOnLowSignal"
+              "randomizeMac"
+            ])
+            (lib.optionalAttrs hasPassword {
+              pskRaw = "ext:${escapePwdKey uniqueKey}"; # this implies changing the external password key if you set a bssid!
+            })
+            {
+              extraConfig = ''
+                ${lib.optionalString scanOnLowSignal "bgscan=\"simple:30:-70:3600\""}
+                ${lib.optionalString randomizeMac "mac_addr=1"}
+              '';
+            }
+          ];
     };
 in
 ns: lib.mkMerge (map go ns)