[OTA] Serve the file specified by the file designator (#15662)

examples/ota-provider-app/esp32/main/include/ota-provider-common/BdxOtaSender.h

@@ -89,9 +89,6 @@ class BdxOtaSender : public chip::bdx::Responder
      */
     uint64_t GetTransferLength(void);
 
-    /* ota-provider-common/OTAProviderExample.cpp requires this */
-    void SetFilepath(const char * path) {}
-
 private:
     // Inherited from bdx::TransferFacilitator
     void HandleTransferSessionOutput(chip::bdx::TransferSession::OutputEvent & event) override;

examples/ota-provider-app/ota-provider-common/BdxOtaSender.cpp

@@ -32,19 +32,7 @@ using chip::bdx::TransferSession;
 
 BdxOtaSender::BdxOtaSender()
 {
-    memset(mFilepath, 0, kFilepathMaxLength);
-}
-
-void BdxOtaSender::SetFilepath(const char * path)
-{
-    if (path != nullptr)
-    {
-        chip::Platform::CopyString(mFilepath, path);
-    }
-    else
-    {
-        memset(mFilepath, 0, kFilepathMaxLength);
-    }
+    memset(mFileDesignator, 0, chip::bdx::kMaxFileDesignatorLen);
 }
 
 void BdxOtaSender::HandleTransferSessionOutput(TransferSession::OutputEvent & event)
@@ -88,6 +76,15 @@ void BdxOtaSender::HandleTransferSessionOutput(TransferSession::OutputEvent & ev
         acceptData.Length       = mTransfer.GetTransferLength();
         VerifyOrReturn(mTransfer.AcceptTransfer(acceptData) == CHIP_NO_ERROR,
                        ChipLogError(BDX, "%s: %s", __FUNCTION__, chip::ErrorStr(err)));
+
+        // Store the file designator used during block query
+        uint16_t fdl       = 0;
+        const uint8_t * fd = mTransfer.GetFileDesignator(fdl);
+        VerifyOrReturn(fdl < chip::bdx::kMaxFileDesignatorLen,
+                       ChipLogError(BDX, "Cannot store file designator with length = %d", fdl));
+        memcpy(mFileDesignator, fd, fdl);
+        mFileDesignator[fdl] = 0;
+
         break;
     }
     case TransferSession::OutputEventType::kQueryReceived: {
@@ -110,7 +107,7 @@ void BdxOtaSender::HandleTransferSessionOutput(TransferSession::OutputEvent & ev
             return;
         }
 
-        std::ifstream otaFile(mFilepath, std::ifstream::in);
+        std::ifstream otaFile(mFileDesignator, std::ifstream::in);
         VerifyOrReturn(otaFile.good(), ChipLogError(BDX, "%s: file read failed", __FUNCTION__));
         otaFile.seekg(mNumBytesSent);
         otaFile.read(reinterpret_cast<char *>(blockBuf->Start()), bytesToRead);
@@ -162,5 +159,5 @@ void BdxOtaSender::Reset()
     }
 
     mNumBytesSent = 0;
-    memset(mFilepath, 0, kFilepathMaxLength);
+    memset(mFileDesignator, 0, chip::bdx::kMaxFileDesignatorLen);
 }

examples/ota-provider-app/ota-provider-common/BdxOtaSender.h

@@ -25,16 +25,14 @@ class BdxOtaSender : public chip::bdx::Responder
 public:
     BdxOtaSender();
 
-    void SetFilepath(const char * path);
-
 private:
     // Inherited from bdx::TransferFacilitator
     void HandleTransferSessionOutput(chip::bdx::TransferSession::OutputEvent & event) override;
 
     void Reset();
 
-    static constexpr size_t kFilepathMaxLength = 256;
-    char mFilepath[kFilepathMaxLength];
+    // Null-terminated string representing file designator
+    char mFileDesignator[chip::bdx::kMaxFileDesignatorLen];
 
     uint32_t mNumBytesSent = 0;
 };

examples/ota-provider-app/ota-provider-common/OTAProviderExample.cpp

@@ -261,7 +261,6 @@ EmberAfStatus OTAProviderExample::HandleQueryImage(chip::app::CommandHandler * c
         ChipLogDetail(SoftwareUpdate, "Generated URI: %.*s", static_cast<int>(uri.size()), uri.data());
 
         // Initialize the transfer session in prepartion for a BDX transfer
-        mBdxOtaSender.SetFilepath(otaFilePath);
         BitFlags<TransferControlFlags> bdxFlags;
         bdxFlags.Set(TransferControlFlags::kReceiverDrive);
         CHIP_ERROR err = mBdxOtaSender.PrepareForTransfer(&chip::DeviceLayer::SystemLayer(), chip::bdx::TransferRole::kSender,

src/app/clusters/ota-requestor/OTARequestor.cpp

@@ -141,6 +141,18 @@ void OTARequestor::OnQueryImageResponse(void * context, const QueryImageResponse
             requestorCore->mTargetVersion = update.softwareVersion;
             requestorCore->mUpdateToken   = updateToken;
 
+            // Store file designator needed for BDX transfers
+            MutableCharSpan fileDesignator(requestorCore->mFileDesignatorBuffer);
+            if (update.fileDesignator.size() > fileDesignator.size())
+            {
+                ChipLogError(SoftwareUpdate, "File designator size %zu is too large to store", update.fileDesignator.size());
+                requestorCore->RecordErrorUpdateState(UpdateFailureState::kQuerying, err);
+                return;
+            }
+            memcpy(fileDesignator.data(), update.fileDesignator.data(), update.fileDesignator.size());
+            fileDesignator.reduce_size(update.fileDesignator.size());
+            requestorCore->mFileDesignator = fileDesignator;
+
             requestorCore->mOtaRequestorDriver->UpdateAvailable(update,
                                                                 System::Clock::Seconds32(response.delayedActionTime.ValueOr(0)));
         }
@@ -656,7 +668,9 @@ CHIP_ERROR OTARequestor::ExtractUpdateDescription(const QueryImageResponseDecoda
 
     VerifyOrReturnError(response.imageURI.HasValue(), CHIP_ERROR_INVALID_ARGUMENT);
     ReturnErrorOnFailure(bdx::ParseURI(response.imageURI.Value(), nodeId, fileDesignator));
-    update.imageURI = response.imageURI.Value();
+    VerifyOrReturnError(IsSpanUsable(fileDesignator), CHIP_ERROR_INVALID_ARGUMENT);
+    update.nodeId         = nodeId;
+    update.fileDesignator = fileDesignator;
 
     VerifyOrReturnError(response.softwareVersion.HasValue(), CHIP_ERROR_INVALID_ARGUMENT);
     VerifyOrReturnError(response.softwareVersionString.HasValue(), CHIP_ERROR_INVALID_ARGUMENT);
@@ -681,9 +695,8 @@ CHIP_ERROR OTARequestor::StartDownload(OperationalDeviceProxy & deviceProxy)
     TransferSession::TransferInitData initOptions;
     initOptions.TransferCtlFlags = bdx::TransferControlFlags::kReceiverDrive;
     initOptions.MaxBlockSize     = mOtaRequestorDriver->GetMaxDownloadBlockSize();
-    char testFileDes[9]          = { "test.txt" };
-    initOptions.FileDesLength    = static_cast<uint16_t>(strlen(testFileDes));
-    initOptions.FileDesignator   = reinterpret_cast<uint8_t *>(testFileDes);
+    initOptions.FileDesLength    = static_cast<uint16_t>(mFileDesignator.size());
+    initOptions.FileDesignator   = reinterpret_cast<const uint8_t *>(mFileDesignator.data());
 
     chip::Messaging::ExchangeManager * exchangeMgr = deviceProxy.GetExchangeManager();
     VerifyOrReturnError(exchangeMgr != nullptr, CHIP_ERROR_INCORRECT_STATE);

src/app/clusters/ota-requestor/OTARequestor.h

@@ -287,8 +287,10 @@ class OTARequestor : public OTARequestorInterface, public BDXDownloader::StateDe
     BDXMessenger mBdxMessenger;                          // TODO: ideally this is held by the application
     uint8_t mUpdateTokenBuffer[kMaxUpdateTokenLen];
     ByteSpan mUpdateToken;
-    uint32_t mCurrentVersion               = 0;
-    uint32_t mTargetVersion                = 0;
+    uint32_t mCurrentVersion = 0;
+    uint32_t mTargetVersion  = 0;
+    char mFileDesignatorBuffer[bdx::kMaxFileDesignatorLen];
+    CharSpan mFileDesignator;
     OTAUpdateStateEnum mCurrentUpdateState = OTAUpdateStateEnum::kIdle;
     Server * mServer                       = nullptr;
     chip::Optional<bool> mRequestorCanConsent;

src/include/platform/OTARequestorDriver.h

@@ -33,7 +33,8 @@ namespace chip {
 // The set of parameters needed for starting a BDX download.
 struct UpdateDescription
 {
-    CharSpan imageURI;
+    NodeId nodeId;
+    CharSpan fileDesignator;
     uint32_t softwareVersion;
     CharSpan softwareVersionStr;
     ByteSpan updateToken;

src/protocols/bdx/BdxMessages.cpp

@@ -31,8 +31,7 @@
 #include <utility>
 
 namespace {
-constexpr uint8_t kVersionMask          = 0x0F;
-constexpr uint8_t kMaxFileDesignatorLen = 32;
+constexpr uint8_t kVersionMask = 0x0F;
 } // namespace
 
 using namespace chip;

src/protocols/bdx/BdxMessages.h

@@ -32,6 +32,8 @@
 namespace chip {
 namespace bdx {
 
+constexpr uint16_t kMaxFileDesignatorLen = 0xFF;
+
 enum class MessageType : uint8_t
 {
     SendInit           = 0x01,

src/protocols/bdx/BdxTransferSession.h

@@ -298,6 +298,11 @@ class DLL_EXPORT TransferSession
     uint64_t GetTransferLength() const { return mTransferLength; }
     uint16_t GetTransferBlockSize() const { return mTransferMaxBlockSize; }
     size_t GetNumBytesProcessed() const { return mNumBytesProcessed; }
+    const uint8_t * GetFileDesignator(uint16_t & fileDesignatorLen) const
+    {
+        fileDesignatorLen = mTransferRequestData.FileDesLength;
+        return mTransferRequestData.FileDesignator;
+    }
 
     TransferSession();