usb: Add utility for D-Bus

Putting all D-Bus related operation to the utils file.

Tested: Call the set/getProperty functions locally and successfully
set/get the corresponding attribute value.

Signed-off-by: George Liu <liuxiwei@inspur.com>
Change-Id: I0e0c33fd6ec5db3a47babaf417b0c708709e580b
diff --git a/utils.cpp b/utils.cpp
index 38de0e4..410ddc8 100644
--- a/utils.cpp
+++ b/utils.cpp
@@ -41,6 +41,45 @@
     return response[0].first;
 }
 
+const PropertyValue getProperty(sdbusplus::bus::bus& bus,
+                                const std::string& objectPath,
+                                const std::string& interface,
+                                const std::string& propertyName)
+{
+    PropertyValue value{};
+    auto service = getService(bus, objectPath, interface);
+    if (service.empty())
+    {
+        return value;
+    }
+
+    auto method = bus.new_method_call(service.c_str(), objectPath.c_str(),
+                                      "org.freedesktop.DBus.Properties", "Get");
+    method.append(interface, propertyName);
+
+    auto reply = bus.call(method);
+    reply.read(value);
+
+    return value;
+}
+
+void setProperty(sdbusplus::bus::bus& bus, const std::string& objectPath,
+                 const std::string& interface, const std::string& propertyName,
+                 const PropertyValue& value)
+{
+    auto service = getService(bus, objectPath, interface);
+    if (service.empty())
+    {
+        return;
+    }
+
+    auto method = bus.new_method_call(service.c_str(), objectPath.c_str(),
+                                      "org.freedesktop.DBus.Properties", "Set");
+    method.append(interface.c_str(), propertyName.c_str(), value);
+
+    bus.call_noreply(method);
+}
+
 void mergeFiles(std::vector<std::string>& srcFiles, std::string& dstFile)
 {
     std::ofstream outFile(dstFile, std::ios::out);