Implement the fallthrough rule to support split tunnel VPNs.

Change-Id: Ibc48caedb5954c6b12bfa553d978bab56c4b09aa
diff --git a/server/Network.cpp b/server/Network.cpp
index 5104de2..0ca6247 100644
--- a/server/Network.cpp
+++ b/server/Network.cpp
@@ -33,6 +33,10 @@
     return mInterfaces.find(interface) != mInterfaces.end();
 }
 
+const std::set<std::string>& Network::getInterfaces() const {
+    return mInterfaces;
+}
+
 int Network::clearInterfaces() {
     while (!mInterfaces.empty()) {
         // Make a copy of the string, so removeInterface() doesn't lose its parameter when it