From 3654861946a1cf9abc96071907d882d25d41dfaf Mon Sep 17 00:00:00 2001
From: Boris Zbarsky <bzbarsky@apple.com>
Date: Mon, 22 Nov 2021 09:43:16 -0500
Subject: [PATCH] Add a way to ask a CommandHandler for a fabric index.
 (#12005)

This returns the accessing fabric index.
---
 src/app/CommandHandler.cpp                        |  5 +++++
 src/app/CommandHandler.h                          |  1 +
 .../operational-credentials-server.cpp            | 15 +++++----------
 3 files changed, 11 insertions(+), 10 deletions(-)

diff --git a/src/app/CommandHandler.cpp b/src/app/CommandHandler.cpp
index cc0b19bc3f7adc..e21a1462d2feee 100644
--- a/src/app/CommandHandler.cpp
+++ b/src/app/CommandHandler.cpp
@@ -370,6 +370,11 @@ TLV::TLVWriter * CommandHandler::GetCommandDataIBTLVWriter()
     }
 }
 
+FabricIndex CommandHandler::GetAccessingFabricIndex() const
+{
+    return mpExchangeCtx->GetSessionHandle().GetFabricIndex();
+}
+
 CommandHandler * CommandHandler::Handle::Get()
 {
     return (mMagic == InteractionModelEngine::GetInstance()->GetMagicNumber()) ? mpHandler : nullptr;
diff --git a/src/app/CommandHandler.h b/src/app/CommandHandler.h
index 544d4e46710521..85a5573cae452a 100644
--- a/src/app/CommandHandler.h
+++ b/src/app/CommandHandler.h
@@ -143,6 +143,7 @@ class CommandHandler : public Command
     CHIP_ERROR PrepareStatus(const CommandPathParams & aCommandPathParams);
     CHIP_ERROR FinishStatus();
     TLV::TLVWriter * GetCommandDataIBTLVWriter();
+    FabricIndex GetAccessingFabricIndex() const;
 
     /**
      * API for adding a data response.  The template parameter T is generally
diff --git a/src/app/clusters/operational-credentials-server/operational-credentials-server.cpp b/src/app/clusters/operational-credentials-server/operational-credentials-server.cpp
index a4818ab0791cf4..f96a3893cf4e49 100644
--- a/src/app/clusters/operational-credentials-server/operational-credentials-server.cpp
+++ b/src/app/clusters/operational-credentials-server/operational-credentials-server.cpp
@@ -175,14 +175,9 @@ void fabricListChanged()
                                            OperationalCredentials::Attributes::CommissionedFabrics::Id);
 }
 
-static FabricInfo * retrieveCurrentFabric()
+static FabricInfo * retrieveCurrentFabric(CommandHandler * aCommandHandler)
 {
-    if (emberAfCurrentCommand()->source == nullptr)
-    {
-        return nullptr;
-    }
-
-    FabricIndex index = emberAfCurrentCommand()->source->GetSessionHandle().GetFabricIndex();
+    FabricIndex index = aCommandHandler->GetAccessingFabricIndex();
     emberAfPrintln(EMBER_AF_PRINT_DEBUG, "OpCreds: Finding fabric with fabricIndex %d", index);
     return Server::GetInstance().GetFabricTable().FindFabricWithIndex(index);
 }
@@ -278,7 +273,7 @@ bool emberAfOperationalCredentialsClusterRemoveFabricCallback(app::CommandHandle
     if (err == CHIP_NO_ERROR)
     {
         chip::Messaging::ExchangeContext * ec = commandObj->GetExchangeContext();
-        FabricIndex currentFabricIndex        = ec->GetSessionHandle().GetFabricIndex();
+        FabricIndex currentFabricIndex        = commandObj->GetAccessingFabricIndex();
         if (currentFabricIndex == fabricBeingRemoved)
         {
             // If the current fabric is being removed, expiring all the secure sessions causes crashes as
@@ -309,7 +304,7 @@ bool emberAfOperationalCredentialsClusterUpdateFabricLabelCallback(app::CommandH
     CHIP_ERROR err;
 
     // Fetch current fabric
-    FabricInfo * fabric = retrieveCurrentFabric();
+    FabricInfo * fabric = retrieveCurrentFabric(commandObj);
     VerifyOrExit(fabric != nullptr, status = EMBER_ZCL_STATUS_FAILURE);
 
     // Set Label on fabric
@@ -442,7 +437,7 @@ bool emberAfOperationalCredentialsClusterUpdateNOCCallback(app::CommandHandler *
     emberAfPrintln(EMBER_AF_PRINT_DEBUG, "OpCreds: an administrator has updated the Op Cert");
 
     // Fetch current fabric
-    FabricInfo * fabric = retrieveCurrentFabric();
+    FabricInfo * fabric = retrieveCurrentFabric(commandObj);
     VerifyOrExit(fabric != nullptr, nocResponse = ConvertToNOCResponseStatus(CHIP_ERROR_INVALID_FABRIC_ID));
 
     err = fabric->SetNOCCert(NOCValue);