Started the state machine implementation.

src/smtpclient.cpp

@@ -25,6 +25,7 @@
 /* [1] Constructors and destructors */
 
 SmtpClient::SmtpClient(const QString & host, int port, ConnectionType connectionType) :
+    state(UnconnectedState),
     name("localhost"),
     authMethod(AuthPlain),
     connectionTimeout(5000),
@@ -377,7 +378,6 @@ void SmtpClient::quit()
 
 
 /* [4] Protected methods */
-
 void SmtpClient::waitForResponse() throw (ResponseTimeoutException)
 {
     if (!socket->waitForReadyRead(responseTimeout))
@@ -386,17 +386,70 @@ void SmtpClient::waitForResponse() throw (ResponseTimeoutException)
         throw ResponseTimeoutException();
     }
 
+    processResponse();
+}
+
+void SmtpClient::changeState(ClientState state) {
+    this->state = state;
+
+    switch (state)
+    {
+    case _ELHO_State:
+        // Service ready. Send ELHO message and chage the state
+        sendMessage("ELHO " + name);
+        break;
+
+    case _TLS_State:
+        // send a request to start TLS handshake
+        sendMessage("STARTTLS");
+        break;
+
+    default:
+        ;
+    }
+
+    if (state <= DisconnectingState) {  // don't emit for internal signals
+        emit stateChanged(state);
+    }
+}
+
+void SmtpClient::processResponse() {
     // Save the server's response
     responseText = socket->readAll();
 
     // Extract the respose code from the server's responce (first 3 digits)
     responseCode = responseText.left(3).toInt();
 
-    if (responseCode / 100 == 4)
-        emit smtpError(ServerError);
+    if (responseCode / 100 == 4) {
+        emit smtpError(ServerError); return;
+    }
 
-    if (responseCode / 100 == 5)
-        emit smtpError(ClientError);
+    if (responseCode / 100 == 5) {
+        emit smtpError(ClientError); return;
+    }
+
+    switch (state)
+    {
+    case ConnectedState:
+        // Just connected to the server. Wait for 220 (Service ready)
+        if (responseCode != 220) {
+            emit smtpError(ServerError); return;
+        }
+        changeState(_ELHO_State);
+        break;
+
+    case _ELHO_State:
+        // The response code needs to be 250.
+        if (responseCode != 250) {
+            emit smtpError(ServerError); return;
+        }
+
+        changeState((connectionType != TlsConnection) ? ReadyState : _TLS_State);
+        break;
+
+    default:
+        ;
+    }
 }
 
 void SmtpClient::sendMessage(const QString &text)
@@ -409,16 +462,28 @@ void SmtpClient::sendMessage(const QString &text)
 
 /* [5] Slots for the socket's signals */
 
-void SmtpClient::socketStateChanged(QAbstractSocket::SocketState state)
-{
+void SmtpClient::socketStateChanged(QAbstractSocket::SocketState state) {
+    switch (state)
+    {
+    case QAbstractSocket::ConnectedState:
+        changeState(ConnectedState);
+
+        break;
+    case QAbstractSocket::UnconnectedState:
+        changeState(UnconnectedState);
+        break;
+    default:
+        ;
+    }
 }
 
-void SmtpClient::socketError(QAbstractSocket::SocketError socketError)
-{
+void SmtpClient::socketError(QAbstractSocket::SocketError socketError) {
+    emit smtpError(SocketError);
 }
 
 void SmtpClient::socketReadyRead()
 {
+
 }
 
 /* [5] --- */

src/smtpclient.h

@@ -44,7 +44,8 @@ public:
         ResponseTimeoutError,
         AuthenticationFailedError,
         ServerError,    // 4xx smtp error
-        ClientError     // 5xx smtp error
+        ClientError,    // 5xx smtp error
+        SocketError
     };
 
     enum ConnectionType
@@ -54,13 +55,24 @@ public:
         TlsConnection       // STARTTLS
     };
 
-    enum State {
-        UnconnectedState,
-        ConnectingState,
-        ConnectedState,
-        AuthenticatingState,
-        MailSendingState,
-        DisconnectingState
+    enum ClientState {
+        UnconnectedState = 0,
+        ConnectingState = 1,
+        ConnectedState = 2,
+        ReadyState = 3,
+        AuthenticatingState = 4,
+        MailSendingState = 5,
+        DisconnectingState = 6,
+
+        /* Internal States */
+        _ELHO_State = 50,
+        _TLS_State = 51,
+
+        /* Internal Substates */
+        _TLS_0_START = 60,
+        _TLS_1_ENCRYPT = 61,
+        _TLS_2_ELHO = 62
+
     };
 
     /* [0] --- */
@@ -126,6 +138,8 @@ protected:
     /* [4] Protected members */
 
     QTcpSocket *socket;
+    ClientState state;
+    bool syncMode;
 
     QString host;
     int port;
@@ -149,6 +163,9 @@ protected:
 
 
     /* [5] Protected methods */
+    void changeState(ClientState state);
+
+    void processResponse();
 
     void waitForResponse() throw (ResponseTimeoutException);
 
@@ -172,6 +189,7 @@ signals:
     /* [7] Signals */
 
     void smtpError(SmtpError e);
+    void stateChanged(ClientState s);
 
     /* [7] --- */