add handler logic to handle SysGetEthDevice

Add a handler to handle code logic outside of the actual IPMI
processing.

Tested: Only ran unit-tests (added new ones).
Change-Id: Iadd8c4f2d9b3e2cfba24ae32cda2ef66177b1177
Signed-off-by: Patrick Venture <venture@google.com>
diff --git a/test/handler_unittest.cpp b/test/handler_unittest.cpp
new file mode 100644
index 0000000..05edc0a
--- /dev/null
+++ b/test/handler_unittest.cpp
@@ -0,0 +1,26 @@
+#include "handler.hpp"
+
+#include <string>
+#include <tuple>
+
+#include <gtest/gtest.h>
+
+namespace google
+{
+namespace ipmi
+{
+
+TEST(HandlerTest, EthCheckValidHappy)
+{
+    // The code returns compiled-in information, and therefore cannot really
+    // fail.
+    Handler h;
+    std::tuple<std::uint8_t, std::string> result = h.getEthDetails();
+    EXPECT_EQ(1, std::get<0>(result));
+    EXPECT_STREQ("eth0", std::get<1>(result).c_str());
+}
+
+// TODO: Add checks for other functions of handler.
+
+} // namespace ipmi
+} // namespace google