Check client before dispatching a request from the node

A node object can outlive the client object it was created by.
If the client pointer is not checked first, a method call from
such a node would result in a segmentation fault.

Change-Id: I6b0581435b4e5460195a83c8afa307f2158282d9
Reviewed-by: Rainer Keller <Rainer.Keller@qt.io>

2 files changed, 48 insertions, 0 deletions

diff --git a/src/plugins/opcua/open62541/qopen62541node.cpp b/src/plugins/opcua/open62541/qopen62541node.cpp
index 9285eba..868c36a 100644
--- a/src/plugins/opcua/open62541/qopen62541node.cpp
+++ b/src/plugins/opcua/open62541/qopen62541node.cpp
@@ -64,6 +64,9 @@ QOpen62541Node::~QOpen62541Node()
 
 bool QOpen62541Node::readAttributes(QOpcUa::NodeAttributes attr, const QString &indexRange)
 {
+    if (!m_client)
+        return false;
+
     UA_NodeId tempId;
     UA_NodeId_copy(&m_nodeId, &tempId);
     return QMetaObject::invokeMethod(m_client->m_backend, "readAttributes",
@@ -76,6 +79,9 @@ bool QOpen62541Node::readAttributes(QOpcUa::NodeAttributes attr, const QString &
 
 bool QOpen62541Node::enableMonitoring(QOpcUa::NodeAttributes attr, const QOpcUaMonitoringParameters &settings)
 {
+    if (!m_client)
+        return false;
+
     UA_NodeId tempId;
     UA_NodeId_copy(&m_nodeId, &tempId);
     return QMetaObject::invokeMethod(m_client->m_backend, "enableMonitoring",
@@ -88,6 +94,9 @@ bool QOpen62541Node::enableMonitoring(QOpcUa::NodeAttributes attr, const QOpcUaM
 
 bool QOpen62541Node::disableMonitoring(QOpcUa::NodeAttributes attr)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "disableMonitoring",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -96,6 +105,9 @@ bool QOpen62541Node::disableMonitoring(QOpcUa::NodeAttributes attr)
 
 bool QOpen62541Node::modifyMonitoring(QOpcUa::NodeAttribute attr, QOpcUaMonitoringParameters::Parameter item, const QVariant &value)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "modifyMonitoring",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -111,6 +123,9 @@ QString QOpen62541Node::nodeId() const
 
 bool QOpen62541Node::browseChildren(QOpcUa::ReferenceTypeId referenceType, QOpcUa::NodeClasses nodeClassMask)
 {
+    if (!m_client)
+        return false;
+
     UA_NodeId tempId;
     UA_NodeId_copy(&m_nodeId, &tempId);
     return QMetaObject::invokeMethod(m_client->m_backend, "browseChildren",
@@ -123,6 +138,9 @@ bool QOpen62541Node::browseChildren(QOpcUa::ReferenceTypeId referenceType, QOpcU
 
 bool QOpen62541Node::writeAttribute(QOpcUa::NodeAttribute attribute, const QVariant &value, QOpcUa::Types type, const QString &indexRange)
 {
+    if (!m_client)
+        return false;
+
     UA_NodeId tempId;
     UA_NodeId_copy(&m_nodeId, &tempId);
     return QMetaObject::invokeMethod(m_client->m_backend, "writeAttribute",
@@ -137,6 +155,9 @@ bool QOpen62541Node::writeAttribute(QOpcUa::NodeAttribute attribute, const QVari
 
 bool QOpen62541Node::writeAttributes(const QOpcUaNode::AttributeMap &toWrite, QOpcUa::Types valueAttributeType)
 {
+    if (!m_client)
+        return false;
+
     UA_NodeId tempId;
     UA_NodeId_copy(&m_nodeId, &tempId);
     return QMetaObject::invokeMethod(m_client->m_backend, "writeAttributes",
@@ -149,6 +170,9 @@ bool QOpen62541Node::writeAttributes(const QOpcUaNode::AttributeMap &toWrite, QO
 
 bool QOpen62541Node::callMethod(const QString &methodNodeId, const QVector<QOpcUa::TypedVariant> &args)
 {
+    if (!m_client)
+        return false;
+
     UA_NodeId obj;
     UA_NodeId_copy(&m_nodeId, &obj);
     return QMetaObject::invokeMethod(m_client->m_backend, "callMethod",
diff --git a/src/plugins/opcua/uacpp/quacppnode.cpp b/src/plugins/opcua/uacpp/quacppnode.cpp
index 920b966..dec71a4 100644
--- a/src/plugins/opcua/uacpp/quacppnode.cpp
+++ b/src/plugins/opcua/uacpp/quacppnode.cpp
@@ -46,6 +46,9 @@ QUACppNode::~QUACppNode()
 
 bool QUACppNode::readAttributes(QOpcUa::NodeAttributes attr, const QString &indexRange)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "readAttributes",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -56,6 +59,9 @@ bool QUACppNode::readAttributes(QOpcUa::NodeAttributes attr, const QString &inde
 
 bool QUACppNode::enableMonitoring(QOpcUa::NodeAttributes attr, const QOpcUaMonitoringParameters &settings)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "enableMonitoring",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -66,6 +72,9 @@ bool QUACppNode::enableMonitoring(QOpcUa::NodeAttributes attr, const QOpcUaMonit
 
 bool QUACppNode::disableMonitoring(QOpcUa::NodeAttributes attr)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "disableMonitoring",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -74,6 +83,9 @@ bool QUACppNode::disableMonitoring(QOpcUa::NodeAttributes attr)
 
 bool QUACppNode::modifyMonitoring(QOpcUa::NodeAttribute attr, QOpcUaMonitoringParameters::Parameter item, const QVariant &value)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "modifyMonitoring",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -84,6 +96,9 @@ bool QUACppNode::modifyMonitoring(QOpcUa::NodeAttribute attr, QOpcUaMonitoringPa
 
 bool QUACppNode::browseChildren(QOpcUa::ReferenceTypeId referenceType, QOpcUa::NodeClasses nodeClassMask)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "browseChildren",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -100,6 +115,9 @@ QString QUACppNode::nodeId() const
 
 bool QUACppNode::writeAttribute(QOpcUa::NodeAttribute attribute, const QVariant &value, QOpcUa::Types type, const QString &indexRange)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "writeAttribute",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -112,6 +130,9 @@ bool QUACppNode::writeAttribute(QOpcUa::NodeAttribute attribute, const QVariant
 
 bool QUACppNode::writeAttributes(const QOpcUaNode::AttributeMap &toWrite, QOpcUa::Types valueAttributeType)
 {
+    if (!m_client)
+        return false;
+
     return QMetaObject::invokeMethod(m_client->m_backend, "writeAttributes",
                                      Qt::QueuedConnection,
                                      Q_ARG(uintptr_t, reinterpret_cast<uintptr_t>(this)),
@@ -123,6 +144,9 @@ bool QUACppNode::writeAttributes(const QOpcUaNode::AttributeMap &toWrite, QOpcUa
 
 bool QUACppNode::callMethod(const QString &methodNodeId, const QVector<QOpcUa::TypedVariant> &args)
 {
+    if (!m_client)
+        return false;
+
     const UaNodeId methodId = UACppUtils::nodeIdFromQString(methodNodeId);
 
     return QMetaObject::invokeMethod(m_client->m_backend, "callMethod",