Validate Logon message before acting upon ResetMsgSeqNum flag (#549)

* [Issue-474] - ResetMsgSeqNum flag in Logon message is processed prior to application level logon message validation fix
* [Issue-474] - testcase
* Corrected usage of `resetSeqNumFlag` in `logonTo`

Co-authored-by: harinda <harinda@yaalalabs.com>
Co-authored-by: Christoph John <christoph.john@macd.com>

Author: 3 people

quickfixj-core/src/main/java/quickfix/Session.java

@@ -1815,12 +1815,14 @@ private boolean verify(Message msg, boolean checkTooHigh, boolean checkTooLow)
                 return false;
             }
 
-            if (checkTooHigh && isTargetTooHigh(msgSeqNum)) {
-                doTargetTooHigh(msg);
-                return false;
-            } else if (checkTooLow && isTargetTooLow(msgSeqNum)) {
-                doTargetTooLow(msg);
-                return false;
+            if(!state.isResetReceived()){
+                if (checkTooHigh && isTargetTooHigh(msgSeqNum)) {
+                    doTargetTooHigh(msg);
+                    return false;
+                } else if (checkTooLow && isTargetTooLow(msgSeqNum)) {
+                    doTargetTooLow(msg);
+                    return false;
+                }
             }
 
             // Handle poss dup where msgSeq is as expected
@@ -2174,6 +2176,10 @@ private void nextLogon(Message logon) throws FieldNotFound, RejectLogon, Incorre
             state.setResetReceived(true);
         }
 
+        if (!verify(logon, false, validateSequenceNumbers)) {
+            return;
+        }
+
         if (state.isResetReceived()) {
             getLog().onEvent("Logon contains ResetSeqNumFlag=Y, resetting sequence numbers to 1");
             if (!state.isResetSent()) {
@@ -2190,9 +2196,6 @@ private void nextLogon(Message logon) throws FieldNotFound, RejectLogon, Incorre
             resetState();
         }
 
-        if (!verify(logon, false, validateSequenceNumbers)) {
-            return;
-        }
 
         // reset logout messages
         state.setLogoutReceived(false);

quickfixj-core/src/test/java/quickfix/SessionTest.java

@@ -27,6 +27,7 @@
 import quickfix.field.Text;
 import quickfix.field.converter.UtcTimeOnlyConverter;
 import quickfix.field.converter.UtcTimestampConverter;
+import quickfix.field.ResetSeqNumFlag;
 import quickfix.fix44.Heartbeat;
 import quickfix.fix44.Logon;
 import quickfix.fix44.Logout;
@@ -2761,6 +2762,83 @@ public void initiatorSession_ShouldWaitForLogoutTimeoutBeforeDisconnecting_WhenS
         assertFor244(application, responder, 1, 0, 1, true);
     }
 
+    /**
+     * https://github.com/quickfix-j/quickfixj/issues/474
+     * */
+    @Test
+    public void msgseqnum_getting_reset_in_rejected_logon_scenario_fix() throws Exception {
+
+        final UnitTestApplication application = new UnitTestApplication(){
+            int logonCount = 0;
+            @Override
+            public void fromAdmin(Message message, SessionID sessionId) throws FieldNotFound,
+                    IncorrectDataFormat, IncorrectTagValue, RejectLogon {
+                super.fromAdmin(message, sessionId);
+                if (message.getHeader().getString(MsgType.FIELD).equals(Logon.MSGTYPE)) {
+                    logonCount += 1;
+                }
+                if (logonCount == 2) {
+                    logonCount += 1;
+                    throw new RejectLogon("RejectLogon");
+                }
+            }
+        };
+
+        final SessionID sessionID = new SessionID(
+                FixVersions.BEGINSTRING_FIX44, "SENDER", "TARGET");
+
+        Session initSession = createSession(sessionID, application, true,
+                true, true);
+        final SessionState state = getSessionState(initSession);
+
+        final UnitTestResponder responder = new UnitTestResponder();
+
+        try{
+            initSession.setResponder(responder);
+            initSession.next();
+            logonTo(initSession);
+
+            Message logon = application.toAdminMessages.get(0);
+            assertEquals(MsgType.LOGON, logon.getHeader().getString(MsgType.FIELD));
+
+
+            assertEquals(2, state.getNextSenderMsgSeqNum());
+            assertTrue(initSession.isLoggedOn());
+
+            initSession.generateHeartbeat();
+            initSession.next(createHeartbeatMessage(2));
+            assertEquals(3, state.getNextSenderMsgSeqNum());
+
+            initSession.generateHeartbeat();
+            initSession.next(createHeartbeatMessage(3));
+            assertEquals(4, state.getNextSenderMsgSeqNum());
+
+            initSession.logout();
+            initSession.next();
+
+            assertEquals(5, state.getNextSenderMsgSeqNum());
+            assertEquals(4, state.getNextTargetMsgSeqNum());
+
+
+        } catch (Exception e) {
+            throw new Exception(e);}
+
+        try {
+            initSession.logon();
+
+            // logon message which will get rejected
+            initSession.next();
+            logonTo(initSession,1,true);
+
+        } catch (Exception e){
+            throw e;
+        }
+
+        assertEquals(6, state.getNextSenderMsgSeqNum());
+        assertEquals(4, state.getNextTargetMsgSeqNum());
+
+    }
+
     /**
      * https://github.com/quickfix-j/quickfixj/issues/244
      * */
@@ -2945,6 +3023,18 @@ private void logonTo(Session session, int sequence) throws FieldNotFound,
         session.next(receivedLogon);
     }
 
+    private void logonTo(Session session, int sequence, boolean resetSeqNumFlag) throws FieldNotFound,
+            RejectLogon, IncorrectDataFormat, IncorrectTagValue,
+            UnsupportedMessageType, IOException, InvalidMessage {
+        final Logon receivedLogon = new Logon();
+        setUpHeader(session.getSessionID(), receivedLogon, true, sequence);
+        receivedLogon.setInt(HeartBtInt.FIELD, 30);
+        receivedLogon.setInt(EncryptMethod.FIELD, 0);
+        receivedLogon.setBoolean(ResetSeqNumFlag.FIELD, resetSeqNumFlag);
+        receivedLogon.toString();   // calculate length and checksum
+        session.next(receivedLogon);
+    }
+
     private void logoutFrom(Session session, int sequence)
             throws FieldNotFound, RejectLogon, IncorrectDataFormat,
             IncorrectTagValue, UnsupportedMessageType, IOException,