sysupgrade: move UCI diff into a separate function lib

For reuse by other modules as well.

wifimngr/files/214-uci-wireless

@@ -13,6 +13,11 @@ if [ -n "$SAVE_CONFIG" ] && [ $SAVE_CONFIG -eq 0 ]; then
 	exit 0
 fi
 
+# Source functions.
+for f in /lib/upgrade/iopsys*.sh; do
+	[ -r "$f" -a -s "$f" ] || continue
+	source $f
+done
 
 [ -d "/lib/config/snapshots/first_boot/uci" ] || exit 0
 
@@ -21,64 +26,7 @@ hasWifi=$(chroot "${2}" db -q get hw.board.hasWifi)
 [ "$hasWifi" = "1" ] || exit 0
 
 
-# Read the very first verion of the wireless settings.
+uci_possibly_migrate_package "wireless" "$2" || exit
-if ! chroot "${2}" uci -c "/lib/config/snapshots/first_boot/uci" \
-		-q show wireless >"/tmp/wireless-first-$$" || \
-		[ ! -s "/tmp/wireless-first-$$" ]; then
-	exit 0
-fi
-
-
-# Let the current UCI export its wireless settings.
-if ! chroot "${2}" uci -q show wireless >"/tmp/wireless-current-$$" || \
-		[ ! -s "/tmp/wireless-current-$$" ]; then
-	exit 0
-fi
-
-# If there a diff between the two?
-if grep -vFf "/tmp/wireless-first-$$"  "/tmp/wireless-current-$$" \
-		>"/tmp/wireless-diff-$$" && [ -s "/tmp/wireless-diff-$$" ]; then
-
-	# Create new config if it doesn't yet exist.
-	[ -s "/etc/config/wireless" ] || : >>"/etc/config/wireless"
-
-	# Extract named section "headers" like e.g:
-	#   wireless.wl0=wifi-device
-	# from current settings.
-	grep -E "wireless\.[^\.@][^\.]+=" "/tmp/wireless-current-$$" \
-		>"/tmp/wireless-named-secs-$$"
-
-	# Check if a named section exist in the diff. If so,
-	# add corresponding named section "header" to the diff.
-	# Example: Is
-	#   wireless.wl0
-	# in the diff? Then add
-	#   wireless.wl0=wifi-device
-	# to the diff as well.
-	while read -t 5 -s line; do		
-		section="${line%%=*}"
-		if grep -qF "$section" "/tmp/wireless-diff-$$"; then
-			echo "$line" >>"/tmp/wireless-diff-$$"
-		fi
-	done <"/tmp/wireless-named-secs-$$"
-
-	# Migration of anonymous section requires special handling.
-	grep ']=' "/tmp/wireless-current-$$" | tr ".@=" " " | \
-		awk '{
-			if(system("uci -q get "$1".@"$2" >/dev/null") != 0 &&				# Does it already exit?
-					system("uci add "$1" "$3" >/dev/null") != 0) {				# If not, then create it.
-				exit 1;
-			}
-		}'
-
-	# Import the diff into the next UCI database. The eval
-	# is for string parsing of quotation marks. The sort for
-	# section "headers" to come first.
-	sort -Vr "/tmp/wireless-diff-$$" | \
-		while read -t 5 -s line; do
-			uci set "$(eval echo $line)"
-		done
-fi
 
 # Report success.
 logger -s -p daemon.info -t post-hooks -- "UCI wireless migrated."