firmware: add upgrade paths for current versions

nginx/domains/firmware.ffmuc.net.conf

@@ -7,12 +7,13 @@ map $http_x_firmware_version $firmwareVersion {
     "~^v(\d+)\.(\d+)\.(\d+)(-next)?" $1.$2.$3$4;
     # old next versions v2020.3.4.1-next1 until v2020.3.5.0-next1
     "~^v2020\.3\..*-next"    "next-v2021";
+    # Old autoupdaters do not send the X-Firmware-Version header
     default                  "unknown";
 }
 
 map $firmwareVersion $targetDirectory {
     # OpenWrt 19.07 (Both Gluon v2019.1.x and v2020.1.x)
-    # Old autoupdaters do not send the X-Firmware-Version header
+    #  Note: we do not have an upgrade path from pre-v2019 firmware
     "unknown"                           $gluon_v2019_1_x;
     "~^2020\.3\.[2-5]"                  $gluon_v2019_1_x;
 
@@ -77,11 +78,12 @@ server {
 
         # Add Gluon releases here that allow an upgrade path to the latest version
         # https://github.com/freifunk-gluon/gluon/wiki/Release-life-cycle#migration-paths-diagram
-        set $gluon_v2019_1_x gluon_v2021.1.x; # we do not have an upgrade path for v2018 and earlier yet
-        set $gluon_v2021_1_x gluon_v2021.1.x;
-        set $gluon_v2022_1_x gluon_v2023.1.x;
-        set $gluon_v2023_1_x gluon_v2023.1.x;
-        set $gluon_v2023_2_x gluon_v2023.2.x;
+        set $gluon_v2019_1_x gluon_v2021.1.x; # we want routers to upgrade from v2019 to v2021 and only then attempt v2023
+        set $gluon_v2021_1_x gluon_v2021.1.x_v2023.1.x;
+        set $gluon_v2022_1_x gluon_v2023.1.x_v2023.2.x;
+        set $gluon_v2023_1_x gluon_v2023.1.x_v2023.2.x;
+        set $gluon_v2023_2_x gluon_v2023.1.x_v2023.2.x;
+        set $gluon_next gluon_next;
 
         if ($targetDirectory = "keep") {
             break;