Verify machine name

Verifying machine name from os-release file vs MANIFEST file in
image. Also supporting backword compatibility for older version
where machine name is not defined.

Tested: tested this with latest image build and manifest file patch

Signed-off-by: Vijay Khemka <vijaykhemka@fb.com>
Change-Id: Icb0ac3f884ea1131e2ffd2bde6b8a37185dc55ea
diff --git a/image_manager.cpp b/image_manager.cpp
index 5b2ff49..422e1bf 100644
--- a/image_manager.cpp
+++ b/image_manager.cpp
@@ -106,6 +106,33 @@
         return -1;
     }
 
+    // Get running machine name
+    std::string currMachine = Version::getBMCMachine(OS_RELEASE_FILE);
+    if (currMachine.empty())
+    {
+        log<level::ERR>("Failed to read machine name from osRelease",
+                        entry("FILENAME=%s", OS_RELEASE_FILE));
+        return -1;
+    }
+
+    // Get machine name for image to be upgraded
+    std::string machineStr =
+        Version::getValue(manifestPath.string(), "MachineName");
+    if (!machineStr.empty())
+    {
+        if (machineStr != currMachine)
+        {
+            log<level::ERR>("BMC upgrade: Machine name doesn't match",
+                            entry("CURR_MACHINE=%s", currMachine.c_str()),
+                            entry("NEW_MACHINE=%s", machineStr.c_str()));
+            return -1;
+        }
+    }
+    else
+    {
+        log<level::WARNING>("No machine name in Manifest file");
+    }
+
     // Get purpose
     auto purposeString = Version::getValue(manifestPath.string(), "purpose");
     if (purposeString.empty())