fff-network: Add migration for Archer C7 WAN ports

With 8d66bdf the port configuration of TP-Link Archer C7 has been
changed to a single-interface configuration.

This had unforseen side effects on upgraded devices. Because WANDEV
is evaluated from the updated network.* file, the port configuration
of the switch is evaluated from the update-safe network.config, which
is now incompatible with the updated interface configuration.

Therefore, a migration script has to be added, which updates the port
configuration in network.config to the new single-interface network
configuration.

Fixes: #60 (gitea)
Signed-off-by: Fabian Bläse <fabian@blaese.de>
Reviewed-by: Robert Langhammer <rlanghammer@web.de>

src/packages/fff/fff-network/Makefile

@@ -1,7 +1,7 @@
 include $(TOPDIR)/rules.mk
 
 PKG_NAME:=fff-network
-PKG_RELEASE:=28
+PKG_RELEASE:=29
 
 include $(INCLUDE_DIR)/package.mk
 

src/packages/fff/fff-network/files/etc/uci-defaults/20-migrate-c7-portconfig

@@ -0,0 +1,14 @@
+BOARD="$(uci get board.model.name)"
+
+# only execute if running on a TP-Link Archer C7 v2
+if [ "$BOARD" != "tplink,archer-c7-v2" ]; then
+	exit 0
+fi
+
+# only execute if there is something to migrate
+if [ ! -s /etc/network.config ]; then
+	exit 0
+fi
+
+# modify WAN_PORTS to new single-interface configuration
+sed -i '/WAN_PORTS/ s/6/0t/g' /etc/network.config