Added error report callback to the gateway session.

gateway/app/gateway/GatewaySession.cpp

@@ -287,6 +287,12 @@ bool GatewaySession::startSession()
                 });
         }); 
 
+    m_session->setErrorReportCb(
+        [this](const char* msg)
+        {
+            m_logger.error() << msg << std::endl;
+        });
+
     if (!m_sessionPtr) {
         // Forwarder encapsulated session
         return true;

gateway/lib/doc/session.dox

@@ -680,3 +680,28 @@
 /// broker and report the @ref cc_mqttsn_gw_session_page_broker_conn "connectivity"
 /// later on. The @b important part is that broker connectivity must be reported
 /// @b after the callback function returns.
+///
+/// @section cc_mqttsn_gw_session_page_error_report Errors Report
+/// The gateway library can detect and report some unexpected behavior from the
+/// application, client, and/or broker. The @b Session object reports such
+/// errors via callback:
+///
+/// @b C++ interface
+/// @code
+/// session->setErrorReportCb(
+///     [](const char* msg)
+///     {
+///         std::cerr << "ERROR: " << msg << std::endl;
+///     });
+/// @endcode
+///
+/// @b C interface
+/// @code
+/// void my_error_report(void* userData, CC_MqttsnSessionHandle session, const char* msg)
+/// {
+///     printf("ERROR: %s\n", msg);
+/// }
+///
+/// cc_mqttsn_gw_session_set_error_report_cb(handle, &my_error_report, someUserData);
+/// @endcode
+///

gateway/lib/include/cc_mqttsn_gateway/Session.h

@@ -88,6 +88,10 @@ class Session
     /// @return Authentication information
     using AuthInfoReqCb = std::function<AuthInfo (const std::string& clientId)>;
 
+    /// @brief Type of the callback used to report detected errors.
+    /// @param[in] msg Error message
+    using ErrorReportCb = std::function<void (const char* msg)>;
+
     /// @brief Type of callback used to notify the application about forwarding encapsulation session being created.
     /// @details The application is responsible to perform the necessary session configuration
     ///     as well as set all the callbacks except the one set by the @ref setSendDataClientReqCb()
@@ -168,6 +172,10 @@ class Session
     /// @param[in] func R-value reference to the callback object
     void setAuthInfoReqCb(AuthInfoReqCb&& func);
 
+    /// @brief Set the callback to be used to report detected errors
+    /// @param[in] func R-value reference to the callback object
+    void setErrorReportCb(ErrorReportCb&& func);
+
     /// @brief Set the callback to be invoked when the forwarding encapsulation session 
     ///     is detected and to notify application about such session creation.
     /// @details When not set, the forwarding enapsulation messages will be ignored

gateway/lib/include/cc_mqttsn_gateway/gateway_all.h

@@ -181,6 +181,28 @@ typedef void (*CC_MqttsnSessionBrokerReconnectReqCb)(void* userData, CC_MqttsnSe
 /// @param[in] clientId Client ID
 typedef void (*CC_MqttsnSessionClientConnectReportCb)(void* userData, CC_MqttsnSessionHandle session, const char* clientId);
 
+/// @brief Type of callback used to request authentication information of
+///     the client that is trying to connect.
+/// @param[in] userData User data passed as the last parameter to the setting function.
+/// @param[in] session Handle of session performing the request
+/// @param[in] clientId Client ID
+/// @param[out] username Username string
+/// @param[out] password Binary password buffer
+/// @param[out] passwordLen Length of the binary password
+typedef void (*CC_MqttsnSessionAuthInfoReqCb)(
+    void* userData,
+    CC_MqttsnSessionHandle session,
+    const char* clientId,
+    const char** username,
+    const unsigned char** password,
+    unsigned* passwordLen);
+
+/// @brief Type of callback used to report error messages detected by the session.
+/// @param[in] userData User data passed as the last parameter to the setting function.
+/// @param[in] session Handle of session performing the request
+/// @param[in] msg Error message
+typedef void (*CC_MqttsnSessionErrorReportCb)(void* userData, CC_MqttsnSessionHandle session, const char* msg);    
+
 /// @brief Type of callback used to report forwarding encapsulated session creation.
 /// @details The application is responsible to perform the necessary session configuration
 ///     as well as set all the callbacks except the one set by the @ref cc_mqttsn_gw_session_set_send_data_to_client_cb()
@@ -198,22 +220,6 @@ typedef bool (*CC_MqttsnSessionFwdEncSessionCreatedCb)(void* userData, CC_Mqttsn
 /// @param[in] session Handle of session object about to be deleted
 typedef void (*CC_MqttsnSessionFwdEncSessionDeletedCb)(void* userData, CC_MqttsnSessionHandle session);
 
-/// @brief Type of callback used to request authentication information of
-///     the client that is trying to connect.
-/// @param[in] userData User data passed as the last parameter to the setting function.
-/// @param[in] session Handle of session performing the request
-/// @param[in] clientId Client ID
-/// @param[out] username Username string
-/// @param[out] password Binary password buffer
-/// @param[out] passwordLen Length of the binary password
-typedef void (*CC_MqttsnSessionAuthInfoReqCb)(
-    void* userData,
-    CC_MqttsnSessionHandle session,
-    const char* clientId,
-    const char** username,
-    const unsigned char** password,
-    unsigned* passwordLen);
-
 /// @brief Allocate @b Session object.
 /// @details The returned handle need to be passed as first parameter
 ///     to all relevant functions. Note that the @b Session object is
@@ -331,6 +337,17 @@ void cc_mqttsn_gw_session_set_auth_info_req_cb(
     CC_MqttsnSessionAuthInfoReqCb cb,
     void* data);
 
+/// @brief Set the callback to be used to report error messages detected by the session.
+/// @details This is an optional callback. 
+/// @param[in] session Handle returned by cc_mqttsn_gw_session_alloc() function.
+/// @param[in] cb Pointer to callback function
+/// @param[in] data Pointer to any user data, will be passed back as first
+///     parameter to the callback.
+void cc_mqttsn_gw_session_set_error_report_cb(
+    CC_MqttsnSessionHandle session,
+    CC_MqttsnSessionErrorReportCb cb,
+    void* data);    
+
 /// @brief Set the callback to be invoked when the forwarding encapsulation session 
 ///     is detected and to notify application about such session creation.
 /// @details When not set, the forwarding enapsulation messages will be ignored

gateway/lib/src/Session.cpp

@@ -58,6 +58,11 @@ void Session::setAuthInfoReqCb(AuthInfoReqCb&& func)
     m_pImpl->setAuthInfoReqCb(std::move(func));
 }
 
+void Session::setErrorReportCb(ErrorReportCb&& func)
+{
+    m_pImpl->setErrorReportCb(std::move(func));
+}
+
 void Session::setFwdEncSessionCreatedReportCb(FwdEncSessionCreatedReportCb&& func)
 {
     m_pImpl->setFwdEncSessionCreatedReportCb(std::move(func));

gateway/lib/src/SessionImpl.cpp

@@ -69,10 +69,12 @@ bool SessionImpl::start()
         (!m_sendToBrokerCb) ||
         (!m_termReqCb) ||
         (!m_brokerReconnectReqCb)) {
+        reportError("Not all \"must have\" callbacks have been set");
         return false;
     }
 
     if (static_cast<bool>(m_fwdEncSessionCreatedReportCb) != static_cast<bool>(m_fwdEncSessionDeletedReportCb)) {
+        reportError("Not all forward encapsulated session management callbacks have been set");
         return false;
     }
 
@@ -127,8 +129,8 @@ std::size_t SessionImpl::dataFromClient(const std::uint8_t* buf, std::size_t len
         }
 
         if (es == comms::ErrorStatus::ProtocolError) {
-            ++bufTmp;
-            continue;
+            reportError("Protocol error from the client side is detected");
+            return len;
         }
 
         if (es == comms::ErrorStatus::Success) {
@@ -273,6 +275,15 @@ SessionImpl::AuthInfo SessionImpl::authInfoRequest(const std::string& clientId)
     return m_authInfoReqCb(clientId);
 }
 
+void SessionImpl::reportError(const char* str)
+{
+    if (!m_errorReportCb) {
+        return;
+    }
+
+    m_errorReportCb(str);
+}
+
 void SessionImpl::handle(SearchgwMsg_SN& msg)
 {
     GwinfoMsg_SN respMsg;

gateway/lib/src/SessionImpl.h

@@ -36,6 +36,7 @@ class SessionImpl : public MsgHandler
     using BrokerReconnectReqCb = Session::BrokerReconnectReqCb;
     using ClientConnectedReportCb = Session::ClientConnectedReportCb;
     using AuthInfoReqCb = Session::AuthInfoReqCb;
+    using ErrorReportCb = Session::ErrorReportCb;
     using FwdEncSessionCreatedReportCb = Session::FwdEncSessionCreatedReportCb;
     using FwdEncSessionDeletedReportCb = Session::FwdEncSessionDeletedReportCb;
 
@@ -91,6 +92,12 @@ class SessionImpl : public MsgHandler
         m_authInfoReqCb = std::forward<TFunc>(func);
     }
 
+    template <typename TFunc>
+    void setErrorReportCb(TFunc&& func)
+    {
+        m_errorReportCb = std::forward<TFunc>(func);
+    }
+
     template <typename TFunc>
     void setFwdEncSessionCreatedReportCb(TFunc&& func)
     {
@@ -210,6 +217,7 @@ class SessionImpl : public MsgHandler
     void brokerReconnectRequest();
     void clientConnectedReport(const std::string& clientId);
     AuthInfo authInfoRequest(const std::string& clientId);
+    void reportError(const char* str);
 
 private:
 
@@ -248,6 +256,7 @@ class SessionImpl : public MsgHandler
     BrokerReconnectReqCb m_brokerReconnectReqCb;
     ClientConnectedReportCb m_clientConnectedCb;
     AuthInfoReqCb m_authInfoReqCb;
+    ErrorReportCb m_errorReportCb;
     FwdEncSessionCreatedReportCb m_fwdEncSessionCreatedReportCb;
     FwdEncSessionDeletedReportCb m_fwdEncSessionDeletedReportCb;
 

gateway/lib/src/gateway_all.cpp

@@ -299,6 +299,22 @@ void cc_mqttsn_gw_session_set_auth_info_req_cb(
         });
 }
 
+void cc_mqttsn_gw_session_set_error_report_cb(
+    CC_MqttsnSessionHandle session,
+    CC_MqttsnSessionErrorReportCb cb,
+    void* data)
+{
+    if (session.obj == nullptr) {
+        return;
+    }    
+
+    reinterpret_cast<Session*>(session.obj)->setErrorReportCb(
+        [cb, data, session](const char* msg)
+        {
+            cb(data, session, msg);
+        });    
+}
+
 void cc_mqttsn_gw_session_set_fwd_enc_session_created_cb(
     CC_MqttsnSessionHandle session,
     CC_MqttsnSessionFwdEncSessionCreatedCb cb,

gateway/lib/src/session_op/Connect.cpp

@@ -55,6 +55,7 @@ void Connect::handle(ConnectMsg_SN& msg)
 
     if ((st.m_connStatus != ConnectionStatus::Disconnected) &&
         (reqClientId != st.m_clientId)) {
+        session().reportError("Different client id reconnection in the same session");
         sendDisconnectToClient();
         state().m_connStatus = ConnectionStatus::Disconnected;
         termRequest();

gateway/lib/src/session_op/Forward.cpp

@@ -7,10 +7,14 @@
 
 #include "Forward.h"
 
+#include "SessionImpl.h"
+
+#include "comms/util/ScopeGuard.h"
+#include "comms/util/assign.h"
+
 #include <cassert>
 #include <algorithm>
 
-#include "comms/util/ScopeGuard.h"
 
 namespace cc_mqttsn_gateway
 {
@@ -49,6 +53,7 @@ void Forward::handle(PublishMsg_SN& msg)
     } while (false);
 
     if (st.m_connStatus != ConnectionStatus::Connected) {
+        session().reportError("PUBLISH from client when not connected");
         sendPubackToClient(
             msg.field_topicId().value(),
             msg.field_msgId().value(),
@@ -66,6 +71,7 @@ void Forward::handle(PublishMsg_SN& msg)
 
     auto& topic = st.m_regMgr.mapTopicId(msg.field_topicId().value());
     if (topic.empty()) {
+        session().reportError("Invalid topic ID in PUBLISH");
         sendPubackToClient(
             msg.field_topicId().value(),
             msg.field_msgId().value(),
@@ -87,7 +93,7 @@ void Forward::handle(PublishMsg_SN& msg)
     fwdMsg.field_topic().value() = topic;
     fwdMsg.field_packetId().field().value() = msg.field_msgId().value();
     auto& data = msg.field_data().value();
-    fwdMsg.field_payload().value().assign(data.begin(), data.end());
+    comms::util::assign(fwdMsg.field_payload().value(), data.begin(), data.end());
     fwdMsg.doRefresh();
     sendToBroker(fwdMsg);
 }
@@ -128,6 +134,7 @@ void Forward::handle(SubscribeMsg_SN& msg)
         };
 
     if (state().m_connStatus != ConnectionStatus::Connected) {
+        session().reportError("SUBSCRIBE from client when not connected");
         sendSubackFunc(ReturnCodeVal::NotSupported);
         return;
     }
@@ -140,9 +147,10 @@ void Forward::handle(SubscribeMsg_SN& msg)
             assert(msg.field_topicId().isMissing());
             assert(msg.field_flags().field_topicIdType().value() == TopicIdTypeVal::Normal);
             auto& topicStorage = msg.field_topicName().field().value();
-            topic.assign(topicStorage.begin(), topicStorage.end());
+            comms::util::assign(topic, topicStorage.begin(), topicStorage.end());
 
             if (topic.empty()) {
+                session().reportError("Empty topic in the SUBSCRIBE message from the client");
                 sendSubackFunc(ReturnCodeVal::NotSupported);
                 sendToBroker(PingreqMsg());
                 return;
@@ -174,6 +182,7 @@ void Forward::handle(SubscribeMsg_SN& msg)
         }
 
         if (msg.field_flags().field_topicIdType().value() != TopicIdTypeVal::PredefinedTopicId) {
+            session().reportError("Unknown topic type in SUBSCRIBE message from the client");
             sendSubackFunc(ReturnCodeVal::NotSupported);
             sendToBroker(PingreqMsg());
             return;
@@ -189,6 +198,7 @@ void Forward::handle(SubscribeMsg_SN& msg)
             break;
         }
 
+        session().reportError("Invalid topic topic ID in SUBSCRIBE message from the client");
         sendSubackFunc(ReturnCodeVal::InvalidTopicId);
         sendToBroker(PingreqMsg());
         return;

gateway/lib/src/session_op/PubSend.cpp

@@ -7,6 +7,8 @@
 
 #include "PubSend.h"
 
+#include "comms/util/assign.h"
+
 #include <cassert>
 #include <algorithm>
 
@@ -241,11 +243,8 @@ void PubSend::doSend()
     }
 
     if (!m_currPub->m_msg.empty()) {
-        auto& dataStorage = msg.field_data().value();
-        using DataStorageType = typename std::decay<decltype(dataStorage)>::type;
-        dataStorage = DataStorageType(&(*m_currPub->m_msg.begin()), m_currPub->m_msg.size());
+        comms::util::assign(msg.field_data().value(), m_currPub->m_msg.begin(), m_currPub->m_msg.end());
     }
-    //msg.field_data().value().assign(m_currPub->m_msg.begin(), m_currPub->m_msg.end());
     sendToClient(msg);
 
     if (m_currPub->m_qos == QoS_AtMostOnceDelivery) {

gateway/lib/src/session_op/WillUpdate.cpp

@@ -7,6 +7,8 @@
 
 #include "WillUpdate.h"
 
+#include "SessionImpl.h"
+
 #include <cassert>
 #include <algorithm>
 
@@ -65,6 +67,7 @@ void WillUpdate::handle([[maybe_unused]] DisconnectMsg_SN& msg)
 void WillUpdate::handle(WilltopicupdMsg_SN& msg)
 {
     if (state().m_connStatus != ConnectionStatus::Connected) {
+        session().reportError("WILLTOPICUPD message from the client when not connected");
         sendTopicResp(ReturnCodeVal::NotSupported);
         return;
     }
@@ -103,6 +106,7 @@ void WillUpdate::handle(WilltopicupdMsg_SN& msg)
 void WillUpdate::handle(WillmsgupdMsg_SN& msg)
 {
     if (state().m_connStatus != ConnectionStatus::Connected) {
+        session().reportError("WILLMSGUPD message from the client when not connected");
         sendMsgResp(ReturnCodeVal::NotSupported);
         return;
     }