server: Reject caching command if tracking is not enabled (#5786)

Signed-off-by: Abhijat Malviya <[email protected]>

Author: abhijat

src/server/server_family.cc

@@ -476,17 +476,23 @@ void ClientCaching(CmdArgList args, SinkReplyBuilder* builder, Transaction* tx,
     return builder->SendError(kSyntaxErr);
   }
 
+  if (!cntx->conn_state.tracking_info_.IsTrackingOn()) {
+    return builder->SendError(
+        "CLIENT CACHING can be called only when the client is in tracking mode with OPTIN or "
+        "OPTOUT mode enabled");
+  }
+
   using Tracking = ConnectionState::ClientTracking;
   CmdArgParser parser{args};
   if (parser.Check("YES")) {
     if (!cntx->conn_state.tracking_info_.HasOption(Tracking::OPTIN)) {
       return builder->SendError(
-          "ERR CLIENT CACHING YES is only valid when tracking is enabled in OPTIN mode");
+          "CLIENT CACHING YES is only valid when tracking is enabled in OPTIN mode");
     }
   } else if (parser.Check("NO")) {
     if (!cntx->conn_state.tracking_info_.HasOption(Tracking::OPTOUT)) {
       return builder->SendError(
-          "ERR CLIENT CACHING NO is only valid when tracking is enabled in OPTOUT mode");
+          "CLIENT CACHING NO is only valid when tracking is enabled in OPTOUT mode");
     }
     cntx->conn_state.tracking_info_.ResetCachingSequenceNumber();
   } else {

src/server/server_family_test.cc

@@ -303,6 +303,12 @@ TEST_F(ServerFamilyTest, ClientTrackingOnAndOff) {
   // case 3. turn off client tracking
   resp = Run({"CLIENT", "TRACKING", "OFF"});
   EXPECT_THAT(resp.GetString(), "OK");
+
+  resp = Run({"CLIENT", "CACHING", "YES"});
+  EXPECT_THAT(
+      resp,
+      ErrArg("CLIENT CACHING can be called only when the client is in tracking mode with OPTIN or "
+             "OPTOUT mode enabled"));
 }
 
 TEST_F(ServerFamilyTest, ClientTrackingReadKey) {