oemcommands: Fix for set security mode to mfg mode

Issue: Set security mode fails to enter manufacturing mode even though
       command got executed successfully.
Fix: As manufacturing mode is reserved, can't enable using set security
     mode command. So returning 0xCC as completion code.

Tested:
Verified using ipmitool raw commands.
Before fix:
Command: ipmitool raw 0x30 0xb4 0x03 0x01 //set security mode to mfg
Response:                       //Success

After fix:
Command:  ipmitool raw 0x30 0xb4 0x03 0x01  //set security mode to mfg
Response: Unable to send RAW command (channel=0x0 netfn=0x30 lun=0x0
          cmd=0xb4 rsp=0xcc): Invalid data field in request

Signed-off-by: Jayaprakash Mutyala <mutyalax.jayaprakash@intel.com>
Change-Id: Ib166bb7d4a5248a7f6f5b04615a9d80e8a78b3fe
diff --git a/src/oemcommands.cpp b/src/oemcommands.cpp
index d2a1811..107a1fe 100644
--- a/src/oemcommands.cpp
+++ b/src/oemcommands.cpp
@@ -2838,6 +2838,15 @@
 #ifdef BMC_VALIDATION_UNSECURE_FEATURE
     if (specialMode)
     {
+        constexpr uint8_t mfgMode = 0x01;
+        // Manufacturing mode is reserved. So can't enable this mode.
+        if (specialMode.value() == mfgMode)
+        {
+            phosphor::logging::log<phosphor::logging::level::INFO>(
+                "ipmiSetSecurityMode: Can't enable Manufacturing mode");
+            return ipmi::responseInvalidFieldRequest();
+        }
+
         ec.clear();
         ctx->bus->yield_method_call<>(
             ctx->yield, ec, specialModeService, specialModeBasePath,