Persist the snmp manager configuration

This commit persist the manager configuration D-Bus objects
and restores it once service starts.

This commit also deletes the associated persistent file whenever
snmp client D-Bus object gets deleted.

Change-Id: I1526b52870ee5dfea30e6527bad3fd12d1191a13
Signed-off-by: Ratan Gupta <ratagupt@in.ibm.com>
diff --git a/configure.ac b/configure.ac
index a0cdbe2..f73d576 100644
--- a/configure.ac
+++ b/configure.ac
@@ -48,6 +48,16 @@
 AS_IF([test "x$OBJ_NETWORK_SNMP" == "x"], [OBJ_NETWORK_SNMP="/xyz/openbmc_project/network/snmp/manager"])
 AC_DEFINE_UNQUOTED([OBJ_NETWORK_SNMP], ["$OBJ_NETWORK_SNMP"], [The network snmp root DBus object path])
 
+AC_ARG_VAR(CLASS_VERSION, [Class version to register with Cereal])
+AS_IF([test "x$CLASS_VERSION" == "x"], [CLASS_VERSION=1])
+AC_DEFINE_UNQUOTED([CLASS_VERSION], [$CLASS_VERSION], [Class version to register with Cereal])
+
+AC_ARG_VAR(SNMP_CONF_PERSIST_PATH, [path of directory having persisted snmp managers.])
+AS_IF([test "x$SNMP_CONF_PERSIST_PATH" == "x"], \
+    [SNMP_CONF_PERSIST_PATH="/var/lib/phosphor-snmp/managers/"])
+AC_DEFINE_UNQUOTED([SNMP_CONF_PERSIST_PATH], ["$SNMP_CONF_PERSIST_PATH"], \
+    [Path of directory having persisted snmp managers.])
+
 
 # Checks for library functions
 LT_INIT # Required for systemd linking