feat(modem): Add iperf test of PPP netif

components/esp_modem/test/target_iperf/CMakeLists.txt

@@ -0,0 +1,10 @@
+# The following five 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)
+
+set(EXTRA_COMPONENT_DIRS    $ENV{IDF_PATH}/examples/system/console/advanced/components
+                            $ENV{IDF_PATH}/examples/common_components/iperf
+                            "../..")
+
+include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+project(pppd_test)

components/esp_modem/test/target_iperf/main/CMakeLists.txt

@@ -0,0 +1,3 @@
+idf_component_register(SRCS "NetworkDCE.cpp"
+                            "cmd_pppclient.c"
+                            "pppd_iperf_main.c")

components/esp_modem/test/target_iperf/main/NetworkDCE.cpp

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+/*
+ * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include "cxx_include/esp_modem_dte.hpp"
+#include "esp_modem_config.h"
+#include "cxx_include/esp_modem_api.hpp"
+#include "cxx_include/esp_modem_dce_factory.hpp"
+#include <memory>
+#include <utility>
+
+using namespace esp_modem;
+using namespace esp_modem::dce_factory;
+
+class NetModule;
+typedef DCE_T<NetModule> NetDCE;
+
+/**
+ * @brief Custom factory which can build and create a DCE using a custom module
+ */
+class NetDCE_Factory: public Factory {
+public:
+    template <typename T, typename ...Args>
+    static DCE_T<T> *create(const config *cfg, Args &&... args)
+    {
+        return build_generic_DCE<T>(cfg, std::forward<Args>(args)...);
+    }
+};
+
+/**
+ * @brief This is a null-module, doesn't define any AT commands, just passes everything to pppd
+ */
+class NetModule: public ModuleIf {
+public:
+    explicit NetModule(std::shared_ptr<DTE> dte, const esp_modem_dce_config *cfg):
+        dte(std::move(dte)) {}
+
+    bool setup_data_mode() override
+    {
+        return true;
+    }
+
+    bool set_mode(modem_mode mode) override
+    {
+        return true;
+    }
+
+    static esp_err_t init(esp_netif_t *netif)
+    {
+        // configure
+        esp_modem_dte_config_t dte_config = ESP_MODEM_DTE_DEFAULT_CONFIG();
+        dte_config.uart_config.baud_rate = 921600;  // check also 460800
+        esp_modem_dce_config dce_config = ESP_MODEM_DCE_DEFAULT_CONFIG("");
+
+        // create DTE and minimal network DCE
+        auto uart_dte = create_uart_dte(&dte_config);
+        dce = NetDCE_Factory::create<NetModule>(&dce_config, uart_dte, netif);
+        return dce == nullptr ? ESP_FAIL : ESP_OK;
+    }
+
+    static void deinit()
+    {
+        delete dce;
+    }
+    static void start()
+    {
+        dce->set_data();
+    }
+    static void stop()
+    {
+        dce->exit_data();
+    }
+
+private:
+    static NetDCE *dce;
+    std::shared_ptr<DTE> dte;
+};
+
+NetDCE *NetModule::dce = nullptr;
+
+extern "C" esp_err_t modem_init_network(esp_netif_t *netif)
+{
+    return NetModule::init(netif);
+}
+
+extern "C" esp_err_t modem_start_network()
+{
+    NetModule::start();
+    return ESP_OK;
+}
+
+extern "C" void modem_stop_network()
+{
+    NetModule::stop();
+}