Per bzbarsky, add a helper to discard our exchange reference without …

…closing it

src/protocols/secure_channel/CASESession.cpp

@@ -122,6 +122,19 @@ void CASESession::CloseExchange()
     }
 }
 
+void CASESession::DiscardExchange()
+{
+    if (mExchangeCtxt != nullptr)
+    {
+        // Make sure the exchange doesn't try to notify us when it closes,
+        // since we might be dead by then.
+        mExchangeCtxt->SetDelegate(nullptr);
+        // Null out mExchangeCtxt so that Clear() doesn't try closing it.  The
+        // exchange will handle that.
+        mExchangeCtxt = nullptr;
+    }
+}
+
 CHIP_ERROR CASESession::ToCachable(CASESessionCachable & cachableSession)
 {
     const NodeId peerNodeId = GetPeerNodeId();
@@ -252,12 +265,9 @@ void CASESession::OnResponseTimeout(ExchangeContext * ec)
     VerifyOrReturn(mExchangeCtxt == ec, ChipLogError(SecureChannel, "CASESession::OnResponseTimeout exchange doesn't match"));
     ChipLogError(SecureChannel, "CASESession timed out while waiting for a response from the peer. Current state was %" PRIu8,
                  mState);
-    // Make sure the exchange doesn't try to notify us when it closes,
-    // since we might be dead by then.
-    mExchangeCtxt->SetDelegate(nullptr);
-    // Null out mExchangeCtxt so that Clear() doesn't try closing it.  The
+    // Discard the exchange so that Clear() doesn't try closing it.  The
     // exchange will handle that.
-    mExchangeCtxt = nullptr;
+    DiscardExchange();
     Clear();
     // Do this last in case the delegate frees us.
     mDelegate->OnSessionEstablishmentError(CHIP_ERROR_TIMEOUT);
@@ -687,11 +697,9 @@ CHIP_ERROR CASESession::HandleSigma2Resume(System::PacketBufferHandle && msg)
 
     mCASESessionEstablished = true;
 
-    // Make sure the exchange doesn't try to notify us when it closes,
-    // since we might be dead by then.
-    mExchangeCtxt->SetDelegate(nullptr);
-    // Forget our exchange, as no additional messages are expected from the peer
-    mExchangeCtxt = nullptr;
+    // Discard the exchange so that Clear() doesn't try closing it.  The
+    // exchange will handle that.
+    DiscardExchange();
 
     // Call delegate to indicate session establishment is successful
     // Do this last in case the delegate frees us.
@@ -1125,9 +1133,9 @@ CHIP_ERROR CASESession::HandleSigma3(System::PacketBufferHandle && msg)
 
     mCASESessionEstablished = true;
 
-    // Forget our exchange, as no additional messages are expected from the peer
-    mExchangeCtxt->SetDelegate(nullptr);
-    mExchangeCtxt = nullptr;
+    // Discard the exchange so that Clear() doesn't try closing it.  The
+    // exchange will handle that.
+    DiscardExchange();
 
     // Call delegate to indicate session establishment is successful
     // Do this last in case the delegate frees us.
@@ -1311,9 +1319,9 @@ void CASESession::OnSuccessStatusReport()
     ChipLogProgress(SecureChannel, "Success status report received. Session was established");
     mCASESessionEstablished = true;
 
-    // Forget our exchange, as no additional messages are expected from the peer
-    mExchangeCtxt->SetDelegate(nullptr);
-    mExchangeCtxt = nullptr;
+    // Discard the exchange so that Clear() doesn't try closing it.  The
+    // exchange will handle that.
+    DiscardExchange();
 
     mState = kInitialized;
 
@@ -1534,10 +1542,9 @@ CHIP_ERROR CASESession::OnMessageReceived(ExchangeContext * ec, const PayloadHea
     // Call delegate to indicate session establishment failure.
     if (err != CHIP_NO_ERROR)
     {
-        // Null out mExchangeCtxt so that Clear() doesn't try closing it.  The
+        // Discard the exchange so that Clear() doesn't try closing it.  The
         // exchange will handle that.
-        mExchangeCtxt->SetDelegate(nullptr);
-        mExchangeCtxt = nullptr;
+        DiscardExchange();
         Clear();
         // Do this last in case the delegate frees us.
         mDelegate->OnSessionEstablishmentError(err);

src/protocols/secure_channel/CASESession.h

@@ -220,6 +220,12 @@ class DLL_EXPORT CASESession : public Messaging::ExchangeDelegate, public Pairin
 
     void CloseExchange();
 
+    /**
+     * Clear our reference to our exchange context pointer so that it can close
+     * itself at some later time.
+     */
+    void DiscardExchange();
+
     // TODO: Remove this and replace with system method to retrieve current time
     CHIP_ERROR SetEffectiveTime(void);
 

src/protocols/secure_channel/PASESession.cpp

@@ -116,6 +116,19 @@ void PASESession::CloseExchange()
     }
 }
 
+void PASESession::DiscardExchange()
+{
+    if (mExchangeCtxt != nullptr)
+    {
+        // Make sure the exchange doesn't try to notify us when it closes,
+        // since we might be dead by then.
+        mExchangeCtxt->SetDelegate(nullptr);
+        // Null out mExchangeCtxt so that Clear() doesn't try closing it.  The
+        // exchange will handle that.
+        mExchangeCtxt = nullptr;
+    }
+}
+
 CHIP_ERROR PASESession::Serialize(PASESessionSerialized & output)
 {
     PASESessionSerializable serializable;
@@ -343,10 +356,9 @@ void PASESession::OnResponseTimeout(ExchangeContext * ec)
     ChipLogError(SecureChannel,
                  "PASESession timed out while waiting for a response from the peer. Expected message type was %" PRIu8,
                  to_underlying(mNextExpectedMsg));
-    // Null out mExchangeCtxt so that Clear() doesn't try closing it.  The
+    // Discard the exchange so that Clear() doesn't try closing it.  The
     // exchange will handle that.
-    mExchangeCtxt->SetDelegate(nullptr);
-    mExchangeCtxt = nullptr;
+    DiscardExchange();
     Clear();
     // Do this last in case the delegate frees us.
     mDelegate->OnSessionEstablishmentError(CHIP_ERROR_TIMEOUT);
@@ -825,9 +837,9 @@ CHIP_ERROR PASESession::HandleMsg3(System::PacketBufferHandle && msg)
 
     mPairingComplete = true;
 
-    // Forget our exchange, as no additional messages are expected from the peer
-    mExchangeCtxt->SetDelegate(nullptr);
-    mExchangeCtxt = nullptr;
+    // Discard the exchange so that Clear() doesn't try closing it.  The
+    // exchange will handle that.
+    DiscardExchange();
 
     // Call delegate to indicate pairing completion
     // Do this last in case the delegate frees us.
@@ -846,9 +858,9 @@ void PASESession::OnSuccessStatusReport()
 {
     mPairingComplete = true;
 
-    // Forget our exchange, as no additional messages are expected from the peer
-    mExchangeCtxt->SetDelegate(nullptr);
-    mExchangeCtxt = nullptr;
+    // Discard the exchange so that Clear() doesn't try closing it.  The
+    // exchange will handle that.
+    DiscardExchange();
 
     // Call delegate to indicate pairing completion
     // Do this last in case the delegate frees us.
@@ -942,10 +954,9 @@ CHIP_ERROR PASESession::OnMessageReceived(ExchangeContext * exchange, const Payl
     // Call delegate to indicate pairing failure
     if (err != CHIP_NO_ERROR)
     {
-        // Null out mExchangeCtxt so that Clear() doesn't try closing it.  The
+        // Discard the exchange so that Clear() doesn't try closing it.  The
         // exchange will handle that.
-        mExchangeCtxt->SetDelegate(nullptr);
-        mExchangeCtxt = nullptr;
+        DiscardExchange();
         Clear();
         ChipLogError(SecureChannel, "Failed during PASE session setup. %s", ErrorStr(err));
         // Do this last in case the delegate frees us.

src/protocols/secure_channel/PASESession.h

@@ -263,6 +263,12 @@ class DLL_EXPORT PASESession : public Messaging::ExchangeDelegate, public Pairin
 
     void CloseExchange();
 
+    /**
+     * Clear our reference to our exchange context pointer so that it can close
+     * itself at some later time.
+     */
+    void DiscardExchange();
+
     SessionEstablishmentDelegate * mDelegate = nullptr;
 
     Protocols::SecureChannel::MsgType mNextExpectedMsg = Protocols::SecureChannel::MsgType::PASE_PakeError;