rpcd-mod-packagelist: add package

Provides a way to acquire the list of installed packages without the
need to have opkg available. It is being used for the GSoC 17 project
implementing easy sysupgrade functionality.

Signed-off-by: Paul Spooren <paul@spooren.de>

utils/rpcd-mod-packagelist/files/packagelist.acl

@@ -0,0 +1,12 @@
+{
+	"packagelist": {
+		"description": "get list of installed software packages",
+		"read": {
+			"ubus": {
+				"packagelist": [
+					"list"
+				]
+			}
+		}
+	}
+}

utils/rpcd-mod-packagelist/files/packagelist.rpcd

@@ -0,0 +1,40 @@
+#!/bin/sh
+
+. /usr/share/libubox/jshn.sh
+
+case "$1" in
+list)
+	json_init
+	json_add_object "list"
+	json_dump
+	;;
+call)
+	case "$2" in
+	list)
+		json_init;
+		json_add_object "packagelist"
+
+		if [ -f /usr/lib/opkg/status ]; then
+			while read var p1 p2 p3; do
+				if [ "$var" = "Package:" ]; then
+					pkg="$p1"
+				fi
+				if [ "$var" = "Version:" ]; then
+					version="$p1"
+				fi
+
+				if [ "$var" = "Status:" \
+					-a "$p1" = "install" \
+					-a "$p2" = "user" \
+					-a "$p3" = "installed" ]; then
+						json_add_string "$pkg" "$version";
+				fi
+			done < /usr/lib/opkg/status
+		fi
+
+		json_close_object
+		json_dump
+		;;
+	esac
+	;;
+esac