Introduce L2CAP infrastructure.

CMakeLists.txt

@@ -55,6 +55,8 @@ idf_component_register(
     "src/NimBLEEddystoneTLM.cpp"
     "src/NimBLEExtAdvertising.cpp"
     "src/NimBLEHIDDevice.cpp"
+    "src/NimBLEL2CAPChannel.cpp"
+    "src/NimBLEL2CAPServer.cpp"
     "src/NimBLERemoteCharacteristic.cpp"
     "src/NimBLERemoteDescriptor.cpp"
     "src/NimBLERemoteService.cpp"

examples/L2CAP/.gitignore

@@ -0,0 +1,5 @@
+.vscode
+build
+sdkconfig
+sdkconfig.old
+dependencies.lock

examples/L2CAP/L2CAP_Client/CMakeLists.txt

@@ -0,0 +1,7 @@
+# The following lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+set(SUPPORTED_TARGETS esp32 esp32s3 esp32c3 esp32c6)
+project(L2CAP_client)

examples/L2CAP/L2CAP_Client/Makefile

@@ -0,0 +1,3 @@
+PROJECT_NAME := L2CAP_client
+
+include $(IDF_PATH)/make/project.mk

examples/L2CAP/L2CAP_Client/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+set(COMPONENT_SRCS "main.cpp")
+set(COMPONENT_ADD_INCLUDEDIRS ".")
+
+register_component()

examples/L2CAP/L2CAP_Client/main/component.mk

@@ -0,0 +1,4 @@
+#
+# "main" pseudo-component makefile.
+#
+# (Uses default behaviour of compiling all source files in directory, adding 'include' to include path.)

examples/L2CAP/L2CAP_Client/main/idf_component.yml

@@ -0,0 +1,3 @@
+dependencies:
+  local/esp-nimble-cpp:
+    path: ../../../../../esp-nimble-cpp/

examples/L2CAP/L2CAP_Client/main/main.cpp

@@ -0,0 +1,165 @@
+#include <NimBLEDevice.h>
+
+// See the following for generating UUIDs:
+// https://www.uuidgenerator.net/
+
+// The remote service we wish to connect to.
+static BLEUUID serviceUUID("dcbc7255-1e9e-49a0-a360-b0430b6c6905");
+// The characteristic of the remote service we are interested in.
+static BLEUUID    charUUID("371a55c8-f251-4ad2-90b3-c7c195b049be");
+
+#define L2CAP_CHANNEL        150
+#define L2CAP_MTU            5000
+
+const BLEAdvertisedDevice* theDevice = NULL;
+BLEClient* theClient = NULL;
+BLEL2CAPChannel* theChannel = NULL;
+
+size_t bytesSent = 0;
+size_t bytesReceived = 0;
+
+class L2CAPChannelCallbacks: public BLEL2CAPChannelCallbacks {
+
+public:
+    void onConnect(NimBLEL2CAPChannel* channel) {
+        printf("L2CAP connection established\n");
+    }
+
+    void onMTUChange(NimBLEL2CAPChannel* channel, uint16_t mtu) {
+        printf("L2CAP MTU changed to %d\n", mtu);
+    }
+
+    void onRead(NimBLEL2CAPChannel* channel, std::vector<uint8_t>& data) {
+        printf("L2CAP read %d bytes\n", data.size());
+    }
+    void onDisconnect(NimBLEL2CAPChannel* channel) {
+        printf("L2CAP disconnected\n");
+    }
+};
+
+class MyClientCallbacks: public BLEClientCallbacks {
+
+    void onConnect(BLEClient* pClient) {
+        printf("GAP connected\n");
+        pClient->setDataLen(251);
+
+        theChannel = BLEL2CAPChannel::connect(pClient, L2CAP_CHANNEL, L2CAP_MTU, new L2CAPChannelCallbacks());
+    }
+
+    void onDisconnect(BLEClient* pClient, int reason) {
+        printf("GAP disconnected (reason: %d)\n", reason);
+        theDevice = NULL;
+        theChannel = NULL;
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+        BLEDevice::getScan()->start(5 * 1000, true);
+    }
+};
+
+class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
+
+    void onResult(const BLEAdvertisedDevice* advertisedDevice) {
+        if (theDevice) { return; }
+        printf("BLE Advertised Device found: %s\n", advertisedDevice->toString().c_str());
+
+        if (!advertisedDevice->haveServiceUUID()) { return; }
+        if (!advertisedDevice->isAdvertisingService(serviceUUID)) { return; }
+
+        printf("Found the device we're interested in!\n");
+        BLEDevice::getScan()->stop();
+
+        // Hand over the device to the other task
+        theDevice = advertisedDevice;
+    }
+};
+
+void connectTask(void *pvParameters) {
+
+    uint8_t sequenceNumber = 0;
+
+    while (true) {
+
+        if (!theDevice) {
+            vTaskDelay(1000 / portTICK_PERIOD_MS);
+            continue;
+        }
+
+        if (!theClient) {
+            theClient = BLEDevice::createClient();
+            theClient->setConnectionParams(6, 6, 0, 42);
+
+            auto callbacks = new MyClientCallbacks();
+            theClient->setClientCallbacks(callbacks);
+
+            auto success = theClient->connect(theDevice);
+            if (!success) {
+                printf("Error: Could not connect to device\n");
+                break;
+            }
+            vTaskDelay(2000 / portTICK_PERIOD_MS);
+            continue;            
+        }
+
+        if (!theChannel) {
+            printf("l2cap channel not initialized\n");
+            vTaskDelay(2000 / portTICK_PERIOD_MS);
+            continue;
+        }
+
+        if (!theChannel->isConnected()) {
+            printf("l2cap channel not connected\n");
+            vTaskDelay(2000 / portTICK_PERIOD_MS);
+            continue;
+        }
+
+        while (theChannel->isConnected()) {
+
+        /*
+            static auto initialDelay = true;
+            if (initialDelay) {
+                printf("Waiting gracefully 3 seconds before sending data\n");
+                vTaskDelay(3000 / portTICK_PERIOD_MS);
+                initialDelay = false;
+            };
+*/
+            std::vector<uint8_t> data(5000, sequenceNumber++);
+            if (theChannel->write(data)) {
+                bytesSent += data.size();
+            } else {
+                printf("failed to send!\n");
+                abort();                
+            }
+        }
+
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+    }
+}
+
+extern "C"
+void app_main(void) {
+    printf("Starting L2CAP client example\n");
+
+    xTaskCreate(connectTask, "connectTask", 5000, NULL, 1, NULL);
+
+    BLEDevice::init("L2CAP-Client");
+    BLEDevice::setMTU(BLE_ATT_MTU_MAX);
+
+    auto scan = BLEDevice::getScan();
+    auto callbacks = new MyAdvertisedDeviceCallbacks();
+    scan->setScanCallbacks(callbacks);
+    scan->setInterval(1349);
+    scan->setWindow(449);
+    scan->setActiveScan(true);
+    scan->start(25 * 1000, false);
+
+    int numberOfSeconds = 0;
+
+    while (bytesSent == 0) {
+        vTaskDelay(10 / portTICK_PERIOD_MS);
+    }
+
+    while (true) {
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+        int bytesSentPerSeconds = bytesSent / ++numberOfSeconds;
+        printf("Bandwidth: %d b/sec = %d KB/sec\n", bytesSentPerSeconds, bytesSentPerSeconds / 1024);
+    }
+}

examples/L2CAP/L2CAP_Client/sdkconfig.defaults

@@ -0,0 +1,13 @@
+# Override some defaults so BT stack is enabled
+# in this example
+
+#
+# BT config
+#
+CONFIG_BT_ENABLED=y
+CONFIG_BTDM_CTRL_MODE_BLE_ONLY=y
+CONFIG_BTDM_CTRL_MODE_BR_EDR_ONLY=n
+CONFIG_BTDM_CTRL_MODE_BTDM=n
+CONFIG_BT_BLUEDROID_ENABLED=n
+CONFIG_BT_NIMBLE_ENABLED=y
+CONFIG_BT_NIMBLE_L2CAP_COC_MAX_NUM=1

examples/L2CAP/L2CAP_Server/CMakeLists.txt

@@ -0,0 +1,7 @@
+# The following lines of boilerplate have to be in your project's
+# CMakeLists in this exact order for cmake to work correctly
+cmake_minimum_required(VERSION 3.5)
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+set(SUPPORTED_TARGETS esp32 esp32s3 esp32c3 esp32c6)
+project(L2CAP_server)

examples/L2CAP/L2CAP_Server/Makefile

@@ -0,0 +1,3 @@
+PROJECT_NAME := L2CAP_server
+
+include $(IDF_PATH)/make/project.mk

examples/L2CAP/L2CAP_Server/main/CMakeLists.txt

@@ -0,0 +1,4 @@
+set(COMPONENT_SRCS "main.cpp")
+set(COMPONENT_ADD_INCLUDEDIRS ".")
+
+register_component()

examples/L2CAP/L2CAP_Server/main/component.mk

@@ -0,0 +1,4 @@
+#
+# "main" pseudo-component makefile.
+#
+# (Uses default behaviour of compiling all source files in directory, adding 'include' to include path.)

examples/L2CAP/L2CAP_Server/main/idf_component.yml

@@ -0,0 +1,3 @@
+dependencies:
+  local/esp-nimble-cpp:
+    path: ../../../../../esp-nimble-cpp/

examples/L2CAP/L2CAP_Server/main/main.cpp

@@ -0,0 +1,90 @@
+#include <NimBLEDevice.h>
+
+// See the following for generating UUIDs:
+// https://www.uuidgenerator.net/
+
+#define SERVICE_UUID        "dcbc7255-1e9e-49a0-a360-b0430b6c6905"
+#define CHARACTERISTIC_UUID "371a55c8-f251-4ad2-90b3-c7c195b049be"
+#define L2CAP_CHANNEL        150
+#define L2CAP_MTU            5000
+
+class GATTCallbacks: public BLEServerCallbacks {
+
+public:
+    void onConnect(BLEServer* pServer, BLEConnInfo& info) {
+        /// Booster #1
+        pServer->setDataLen(info.getConnHandle(), 251);
+        /// Booster #2 (especially for Apple devices)
+        BLEDevice::getServer()->updateConnParams(info.getConnHandle(), 12, 12, 0, 200);
+    }
+};
+
+class L2CAPChannelCallbacks: public BLEL2CAPChannelCallbacks {
+
+public:
+    bool connected = false;
+    size_t numberOfReceivedBytes;
+    uint8_t nextSequenceNumber;
+
+public:
+    void onConnect(NimBLEL2CAPChannel* channel) {
+        printf("L2CAP connection established\n");
+        connected = true;
+        numberOfReceivedBytes = nextSequenceNumber = 0;
+    }
+
+    void onRead(NimBLEL2CAPChannel* channel, std::vector<uint8_t>& data) {
+        numberOfReceivedBytes += data.size();
+        size_t sequenceNumber = data[0];
+        printf("L2CAP read %d bytes w/ sequence number %d", data.size(), sequenceNumber);
+        if (sequenceNumber != nextSequenceNumber) {
+            printf("(wrong sequence number %d, expected %d)\n", sequenceNumber, nextSequenceNumber);
+        } else {
+            printf("\n");
+            nextSequenceNumber++;
+        }
+    }
+    void onDisconnect(NimBLEL2CAPChannel* channel) {
+        printf("L2CAP disconnected\n");
+        connected = false;
+    }
+};
+
+extern "C"
+void app_main(void) {
+    printf("Starting L2CAP server example [%lu free] [%lu min]\n", esp_get_free_heap_size(), esp_get_minimum_free_heap_size());
+
+    BLEDevice::init("L2CAP-Server");
+    BLEDevice::setMTU(BLE_ATT_MTU_MAX);
+
+    auto cocServer = BLEDevice::createL2CAPServer();
+    auto l2capChannelCallbacks = new L2CAPChannelCallbacks();
+    auto channel = cocServer->createService(L2CAP_CHANNEL, L2CAP_MTU, l2capChannelCallbacks);
+
+    auto server = BLEDevice::createServer();
+    server->setCallbacks(new GATTCallbacks());
+    auto service = server->createService(SERVICE_UUID);
+    auto characteristic = service->createCharacteristic(CHARACTERISTIC_UUID, NIMBLE_PROPERTY::READ);
+    characteristic->setValue(L2CAP_CHANNEL);
+    service->start();
+    auto advertising = BLEDevice::getAdvertising();
+    advertising->addServiceUUID(SERVICE_UUID);
+    advertising->enableScanResponse(true);
+
+    BLEDevice::startAdvertising();
+    printf("Server waiting for connection requests [%lu free] [%lu min]\n", esp_get_free_heap_size(), esp_get_minimum_free_heap_size());
+
+    // Wait until transfer actually starts...
+    while (!l2capChannelCallbacks->numberOfReceivedBytes) {
+        vTaskDelay(10 / portTICK_PERIOD_MS);
+    }
+    printf("\n\n\n");
+    int numberOfSeconds = 0;
+
+    while (true) {
+        vTaskDelay(1000 / portTICK_PERIOD_MS);
+        if (!l2capChannelCallbacks->connected) { continue; }
+        int bps = l2capChannelCallbacks->numberOfReceivedBytes / ++numberOfSeconds;
+        printf("Bandwidth: %d b/sec = %d KB/sec [%lu free] [%lu min]\n", bps, bps / 1024, esp_get_free_heap_size(), esp_get_minimum_free_heap_size());
+    }
+}

examples/L2CAP/L2CAP_Server/sdkconfig.defaults

@@ -0,0 +1,13 @@
+# Override some defaults so BT stack is enabled
+# in this example
+
+#
+# BT config
+#
+CONFIG_BT_ENABLED=y
+CONFIG_BTDM_CTRL_MODE_BLE_ONLY=y
+CONFIG_BTDM_CTRL_MODE_BR_EDR_ONLY=n
+CONFIG_BTDM_CTRL_MODE_BTDM=n
+CONFIG_BT_BLUEDROID_ENABLED=n
+CONFIG_BT_NIMBLE_ENABLED=y
+CONFIG_BT_NIMBLE_L2CAP_COC_MAX_NUM=1