Merge pull request #905 from david-cermak/fix/eppp_netif_rx_err

[eppp]: Fix tun netif to (optionally) return errors

.github/workflows/esp_dns__build.yml

@@ -33,6 +33,9 @@ jobs:
         shell: bash
         working-directory: ${{matrix.test.path}}
         run: |
+          if [[ "${{ matrix.idf_ver }}" == "release-v5.3" || "${{ matrix.idf_ver }}" == "release-v5.4" ]]; then
+            export EXPECTED_WARNING="unknown kconfig symbol 'LWIP_USE_ESP_GETADDRINFO'"
+          fi
           . ${IDF_PATH}/export.sh
           pip install idf-component-manager idf-build-apps --upgrade
           python ../../../ci/build_apps.py ./${{ matrix.test.app }} --target ${{ matrix.idf_target }} -vv --preserve-all --pytest-app

.github/workflows/examples_build-host-test.yml

@@ -59,10 +59,11 @@ jobs:
       - name: Build with IDF-${{ matrix.idf_ver }}
         shell: bash
         run: |
+          . ${GITHUB_WORKSPACE}/ci/config_env.sh
           . ${IDF_PATH}/export.sh
           python -m pip install idf-build-apps
-          python ./ci/build_apps.py examples/mqtt -l -t linux
-          timeout 5 ./examples/mqtt/build_linux_default/esp_mqtt_demo.elf | tee test.log  || true
+          python ./ci/build_apps.py examples/mqtt -l -t linux -r 'sdkconfig.ci'
+          timeout 5 ./examples/mqtt/build_linux/esp_mqtt_demo.elf | tee test.log  || true
           grep 'MQTT_EVENT_DATA' test.log
 
   run_on_target:

.github/workflows/mdns__host-tests.yml

@@ -24,7 +24,7 @@ jobs:
         shell: bash
         run: |
           . ${IDF_PATH}/export.sh
-          python -m pip install idf-build-apps dnspython pytest pytest-embedded pytest-embedded-serial-esp pytest-embedded-idf
+          python -m pip install idf-build-apps==2.10.0 dnspython pytest pytest-embedded pytest-embedded-serial-esp pytest-embedded-idf
           cd $GITHUB_WORKSPACE/protocols
           # Build host tests app (with all configs and targets supported)
           python ./ci/build_apps.py components/mdns/tests/host_test/

.github/workflows/modem__build-host-tests.yml

@@ -45,7 +45,7 @@ jobs:
     strategy:
       matrix:
         idf_ver: ["release-v5.0", "release-v5.1", "release-v5.2", "release-v5.3", "release-v5.4", "latest"]
-        test: ["target", "target_ota", "target_iperf"]
+        test: ["target", "target_ota", "target_iperf", "target_urc"]
 
     runs-on: ubuntu-22.04
     container: espressif/idf:${{ matrix.idf_ver }}

.github/workflows/modem__target-test.yml

@@ -34,18 +34,16 @@ jobs:
           IDF_TARGET: ${{ matrix.idf_target }}
           SDKCONFIG: sdkconfig.ci.${{ matrix.test.app }}
         shell: bash
-        working-directory: ${{ env.TEST_DIR }}
         run: |
+          . ${GITHUB_WORKSPACE}/ci/config_env.sh
           . ${IDF_PATH}/export.sh
-          rm -rf sdkconfig build
-          [ -f ${SDKCONFIG} ] && cp ${SDKCONFIG} sdkconfig.defaults
-          idf.py set-target ${{ matrix.idf_target }}
-          idf.py build
-          $GITHUB_WORKSPACE/ci/clean_build_artifacts.sh ${GITHUB_WORKSPACE}/${TEST_DIR}/build
+          python -m pip install idf-build-apps
+          python ./ci/build_apps.py ${{ env.TEST_DIR }} -t ${{ matrix.idf_target }} -r 'sdkconfig.ci.${{ matrix.test.app }}'
+          $GITHUB_WORKSPACE/ci/clean_build_artifacts.sh ${GITHUB_WORKSPACE}/${TEST_DIR}/build_${{ matrix.idf_target }}
       - uses: actions/upload-artifact@v4
         with:
           name: modem_target_bin_${{ matrix.idf_target }}_${{ matrix.idf_ver }}_${{ matrix.test.app }}
-          path: ${{ env.TEST_DIR }}/build
+          path: ${{ env.TEST_DIR }}/build_${{ matrix.idf_target }}
           if-no-files-found: error
 
   target_tests_esp_modem:

.github/workflows/modem_sim__build.yml

@@ -0,0 +1,32 @@
+name: "modem_sim: build-tests"
+
+on:
+  push:
+    branches:
+      - master
+  pull_request:
+    types: [opened, synchronize, reopened, labeled]
+
+jobs:
+  build_modem_sim:
+    if: contains(github.event.pull_request.labels.*.name, 'modem_sim') || github.event_name == 'push'
+    name: Build
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout esp-protocols
+        uses: actions/checkout@v3
+      - name: Checkout idf
+        uses: actions/checkout@v3
+        with:
+          repository: espressif/esp-idf
+          ref: 8ad0d3d8f2faab752635bee36070313c47c07a13
+          path: idf
+      - name: Build ESP-AT with IDF-${{ matrix.idf_ver }}
+        shell: bash
+        run: |
+          export IDF_PATH=$GITHUB_WORKSPACE/idf
+          ${IDF_PATH}/install.sh
+          cd common_components/modem_sim
+          ./install.sh
+          source export.sh
+          idf.py build

.github/workflows/mosq__build.yml

@@ -13,11 +13,19 @@ jobs:
     name: Mosquitto build
     strategy:
       matrix:
-        idf_ver: ["latest", "release-v5.3"]
+        idf_ver: ["latest", "release-v5.5", "release-v5.4", "release-v5.3", "release-v5.2", "release-v5.1"]
+        example: ["broker", "serverless_mqtt"]
+        exclude:
+          # serverless_mqtt is not supported on v5.1 and master (esp-peer dependency)
+          - idf_ver: "release-v5.1"
+            example: "serverless_mqtt"
+          - idf_ver: "latest"
+            example: "serverless_mqtt"
+
     runs-on: ubuntu-22.04
     container: espressif/idf:${{ matrix.idf_ver }}
     env:
-      TEST_DIR: components/mosquitto/examples
+      TEST_DIR: components/mosquitto/examples/${{ matrix.example }}
       TARGET_TEST: broker
       TARGET_TEST_DIR: build_esp32_default
     steps:
@@ -31,14 +39,17 @@ jobs:
           . ${IDF_PATH}/export.sh
           pip install idf-component-manager idf-build-apps --upgrade
           python ci/build_apps.py -c ${TEST_DIR} -m components/mosquitto/.build-test-rules.yml
-          # upload only the target test artifacts
-          cd ${TEST_DIR}/${TARGET_TEST}
-          ${GITHUB_WORKSPACE}/ci/clean_build_artifacts.sh `pwd`/${TARGET_TEST_DIR}
-          zip -qur artifacts.zip ${TARGET_TEST_DIR}
+          if [ "${{ matrix.example }}" == "${TARGET_TEST}" ]; then
+            # upload only the target test artifacts
+            cd ${TEST_DIR}
+            ${GITHUB_WORKSPACE}/ci/clean_build_artifacts.sh `pwd`/${TARGET_TEST_DIR}
+            zip -qur artifacts.zip ${TARGET_TEST_DIR}
+          fi
       - uses: actions/upload-artifact@v4
+        if: ${{ matrix.example == 'broker' }}
         with:
           name: mosq_target_esp32_${{ matrix.idf_ver }}
-          path: ${{ env.TEST_DIR }}/${{ env.TARGET_TEST }}/artifacts.zip
+          path: ${{ env.TEST_DIR }}/artifacts.zip
           if-no-files-found: error
 
   test_mosq:

.github/workflows/pre_commit_check.yml

@@ -39,7 +39,7 @@ jobs:
           if ! pre-commit run --from-ref origin/HEAD --to-ref HEAD --hook-stage manual --show-diff-on-failure ; then
             echo ""
             echo "::notice::It looks like the commits in this PR have been made without having pre-commit hooks installed."
-            echo "::notice::Please see https://github.com/espressif/esp-protocols/CONTRIBUTING.md for instructions."
+            echo "::notice::Please see https://github.com/espressif/esp-protocols/blob/master/CONTRIBUTING.md for instructions."
             echo ""
             exit 1
           fi

.gitignore

@@ -94,3 +94,9 @@ docs/html
 
 # esp-idf managed components
 **/managed_components/**
+
+# modem simulator uses esp-at clone
+common_components/modem_sim/modem_sim_esp32/
+
+# repository release tools
+release_notes.txt

.pre-commit-config.yaml

@@ -25,12 +25,8 @@ repos:
            (?x)^(
                .*.py
            )$
-  - repo: https://github.com/myint/unify
-    rev: v0.5
-    hooks:
-      - id: unify
-  - repo: https://github.com/pre-commit/mirrors-yapf
-    rev: "v0.32.0"
+  - repo: https://github.com/google/yapf
+    rev: "v0.43.0"
     hooks:
       - id: yapf
         args: ['style={based_on_style: google, column_limit: 160, indent_width: 4}']
@@ -39,7 +35,7 @@ repos:
     hooks:
       - id: isort
   - repo: https://github.com/myint/eradicate/
-    rev: v2.1.0
+    rev: 3.0.0
     hooks:
       - id: eradicate
   - repo: https://github.com/espressif/check-copyright/
@@ -61,8 +57,8 @@ repos:
   - repo: local
     hooks:
       - id: commit message scopes
-        name: "commit message must be scoped with: mdns, dns, modem, websocket, asio, mqtt_cxx, console, common, eppp, tls_cxx, mosq, sockutls, lws"
-        entry: '\A(?!(feat|fix|ci|bump|test|docs|chore)\((mdns|dns|modem|common|console|websocket|asio|mqtt_cxx|examples|eppp|tls_cxx|mosq|sockutls|lws)\)\:)'
+        name: "commit message must be scoped with: mdns, dns, modem, websocket, asio, mqtt_cxx, console, common, eppp, tls_cxx, mosq, sockutls, lws, modem_sim"
+        entry: '\A(?!(feat|fix|ci|bump|test|docs|chore)\((mdns|dns|modem|common|console|websocket|asio|mqtt_cxx|examples|eppp|tls_cxx|mosq|sockutls|lws|modem_sim)\)\:)'
         language: pygrep
         args: [--multiline]
         stages: [commit-msg]

ci/build_apps.py

@@ -65,6 +65,7 @@ if __name__ == '__main__':
 
     sys.exit(
         build_apps(apps,
+                   verbose=2,
                    dry_run=False,
                    keep_going=False,
                    no_preserve=args.delete,

ci/config_env.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+# This script is used to set some common variables for the CI pipeline.
+
+set -e
+
+# MQTT public broker URI
+export CI_MQTT_BROKER_URI="test.mosquitto.org"

ci/ignore_build_warnings.txt

@@ -1 +1,6 @@
 DeprecationWarning: pkg_resources is deprecated as an API
+Warning: Deprecated: Option '--flash_size' is deprecated. Use '--flash-size' instead.
+Warning: Deprecated: Option '--flash_mode' is deprecated. Use '--flash-mode' instead.
+Warning: Deprecated: Option '--flash_freq' is deprecated. Use '--flash-freq' instead.
+Warning: Deprecated: Command 'sign_data' is deprecated. Use 'sign-data' instead.
+Warning: Deprecated: Command 'extract_public_key' is deprecated. Use 'extract-public-key' instead.

common_components/modem_sim/README.md

@@ -0,0 +1,51 @@
+# Modem Simulator Component
+
+A Wi-Fi modem simulator that extends ESP-AT with PPP server capabilities, turning ESP32 into a fully functional Wi-Fi modem. Perfect for testing AT commands and PPP connections without real hardware dependencies.
+
+## What it does
+
+- Extends ESP-AT firmware with PPP server functionality
+- Provides DATA mode for raw IP communication
+- Enables existing communication stacks (MQTT, HTTP, custom protocols) to work over Wi-Fi
+- Ideal for testing ESP-Modem library and CI reliability
+
+## Quick Start
+
+```bash
+cd common_components/modem_sim
+./install.sh
+source export.sh
+idf.py build
+```
+
+## Custom Platform/Module
+
+```bash
+./install.sh PLATFORM_ESP32S3 WROOM-32
+```
+
+## Configuration
+
+The `sdkconfig.defaults` includes:
+- Wi-Fi and Bluetooth enabled
+- PPP server support
+- AT commands for HTTP/MQTT
+- 4MB flash configuration
+
+## Project Structure
+
+```
+modem_sim/
+├── install.sh              # Installation script
+├── export.sh               # Environment setup
+├── sdkconfig.defaults      # Default configuration
+├── pppd_cmd/               # Custom PPP commands
+└── modem_sim_esp32/        # Generated ESP-AT build
+```
+
+## Use Cases
+
+- Testing ESP-Modem library without real hardware
+- Quick Wi-Fi connectivity for existing communication stacks
+- CI/CD testing with reliable modem simulation
+- Development and debugging of AT command implementations

common_components/modem_sim/export.sh

@@ -0,0 +1,11 @@
+#!/bin/bash
+
+source $IDF_PATH/export.sh
+
+export AT_CUSTOM_COMPONENTS="`pwd`/pppd_cmd"
+
+cd modem_sim_esp32/esp-at
+
+python -m pip install -r requirements.txt
+
+python build.py reconfigure

common_components/modem_sim/install.sh

@@ -0,0 +1,64 @@
+#!/bin/bash
+set -e
+
+# Create directory "modem_sim_esp32", go inside it
+# Usage: ./install.sh [platform] [module]
+
+SCRIPT_DIR=$(pwd)
+mkdir -p modem_sim_esp32
+cd modem_sim_esp32
+
+if [ -z "$IDF_PATH" ]; then
+    echo "Error: IDF_PATH environment variable is not set"
+    exit 1
+fi
+
+# Default ESP_AT_VERSION uses this specific commit from master to support new chips and features
+ESP_AT_VERSION="aa9d7e0e9b741744f7bf5bec3bbf887cff033d5f"
+
+# Shallow clone of esp-at.git at $ESP_AT_VERSION
+if [ ! -d "esp-at" ]; then
+    # cannot shallow clone from a specific commit, so we init, shallow fetch, and checkout
+    mkdir -p esp-at && cd esp-at && git init && git remote add origin https://github.com/espressif/esp-at.git
+    git fetch --depth 1 origin $ESP_AT_VERSION && git checkout $ESP_AT_VERSION
+else
+    echo "esp-at directory already exists, skipping clone."
+    cd esp-at
+fi
+
+# Add esp-idf directory which is a symlink to the $IDF_PATH
+if [ ! -L "esp-idf" ]; then
+    ln -sf "$IDF_PATH" esp-idf
+else
+    echo "esp-idf symlink already exists, skipping."
+fi
+
+# Create "build" directory
+mkdir -p build
+
+# Default values for platform and module
+platform="PLATFORM_ESP32"
+module="WROOM-32"
+
+# Override defaults if parameters are provided
+if [ ! -z "$1" ]; then
+    platform="$1"
+fi
+if [ ! -z "$2" ]; then
+    module="$2"
+fi
+
+# Create file "build/module_info.json" with content
+cat > build/module_info.json << EOF
+{
+    "platform": "$platform",
+    "module": "$module",
+    "description": "4MB, Wi-Fi + BLE, OTA, TX:17 RX:16",
+    "silence": 0
+}
+EOF
+
+cp "$SCRIPT_DIR/sdkconfig.defaults" "module_config/module_esp32_default/sdkconfig.defaults"
+
+echo "Installation completed successfully!"
+echo "Created modem_sim_esp32 directory with esp-at repository and configuration"

common_components/modem_sim/pppd_cmd/CMakeLists.txt

@@ -0,0 +1,6 @@
+idf_component_register(
+    SRCS additional_commands.c
+    INCLUDE_DIRS include
+    REQUIRES at freertos nvs_flash)
+
+idf_component_set_property(${COMPONENT_NAME} WHOLE_ARCHIVE TRUE)

common_components/modem_sim/pppd_cmd/additional_commands.c

@@ -0,0 +1,411 @@
+/*
+ * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#include <stdio.h>
+#include <string.h>
+#include <stdbool.h>
+#include "esp_at.h"
+#include "driver/gpio.h"
+#include "driver/uart.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "freertos/semphr.h"
+#include "freertos/queue.h"
+#include "esp_netif.h"
+#include "esp_netif_ppp.h"
+#include "esp_check.h"
+#include "esp_http_server.h"
+#include "esp_timer.h"
+
+static uint8_t at_test_cmd_test(uint8_t *cmd_name)
+{
+    uint8_t buffer[64] = {0};
+    snprintf((char *)buffer, 64, "test command: <AT%s=?> is executed\r\n", cmd_name);
+    esp_at_port_write_data(buffer, strlen((char *)buffer));
+
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_query_cmd_test(uint8_t *cmd_name)
+{
+    uint8_t buffer[64] = {0};
+    snprintf((char *)buffer, 64, "query command: <AT%s?> is executed\r\n", cmd_name);
+    esp_at_port_write_data(buffer, strlen((char *)buffer));
+
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_setup_cmd_test(uint8_t para_num)
+{
+    uint8_t index = 0;
+    printf("setup command: <AT%s=%d> is executed\r\n", esp_at_get_current_cmd_name(), para_num);
+
+    // get first parameter, and parse it into a digit
+    int32_t digit = 0;
+    if (esp_at_get_para_as_digit(index++, &digit) != ESP_AT_PARA_PARSE_RESULT_OK) {
+        return ESP_AT_RESULT_CODE_ERROR;
+    }
+    printf("digit: %d\r\n", digit);
+
+    // get second parameter, and parse it into a string
+    uint8_t *str = NULL;
+    if (esp_at_get_para_as_str(index++, &str) != ESP_AT_PARA_PARSE_RESULT_OK) {
+        return ESP_AT_RESULT_CODE_ERROR;
+    }
+    printf("string: %s\r\n", str);
+
+    // allocate a buffer and construct the data, then send the data to mcu via interface (uart/spi/sdio/socket)
+    uint8_t *buffer = (uint8_t *)malloc(512);
+    if (!buffer) {
+        return ESP_AT_RESULT_CODE_ERROR;
+    }
+    int len = snprintf((char *)buffer, 512, "setup command: <AT%s=%d,\"%s\"> is executed\r\n",
+                       esp_at_get_current_cmd_name(), digit, str);
+    esp_at_port_write_data(buffer, len);
+
+    // remember to free the buffer
+    free(buffer);
+
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+#define TAG "at_custom_cmd"
+static esp_netif_t *s_netif = NULL;
+static httpd_handle_t http_server = NULL;
+
+static void on_ppp_event(void *arg, esp_event_base_t base, int32_t event_id, void *data)
+{
+    esp_netif_t **netif = data;
+    if (base == NETIF_PPP_STATUS && event_id == NETIF_PPP_ERRORUSER) {
+        printf("Disconnected!");
+    }
+}
+
+static void on_ip_event(void *arg, esp_event_base_t base, int32_t event_id, void *data)
+{
+    ip_event_got_ip_t *event = (ip_event_got_ip_t *)data;
+    esp_netif_t *netif = event->esp_netif;
+    if (event_id == IP_EVENT_PPP_GOT_IP) {
+        printf("Got IPv4 event: Interface \"%s(%s)\" address: " IPSTR, esp_netif_get_desc(netif),
+               esp_netif_get_ifkey(netif), IP2STR(&event->ip_info.ip));
+        ESP_ERROR_CHECK(esp_netif_napt_enable(s_netif));
+
+    } else if (event_id == IP_EVENT_PPP_LOST_IP) {
+        ESP_LOGI(TAG, "Disconnected");
+    }
+}
+
+static SemaphoreHandle_t at_sync_sema = NULL;
+static void wait_data_callback(void)
+{
+    static uint8_t buffer[1500] = {0};
+    int len = esp_at_port_read_data(buffer, sizeof(buffer) - 1);
+
+    // Check for the escape sequence "+++" in the received data
+    const uint8_t escape_seq[] = "+++";
+    uint8_t *escape_ptr = memmem(buffer, len, escape_seq, 3);
+
+    if (escape_ptr != NULL) {
+        printf("Found +++ sequence, signal to the command processing thread\n");
+
+        int data_before_escape = escape_ptr - buffer;
+        if (data_before_escape > 0) {
+            esp_netif_receive(s_netif, buffer, data_before_escape, NULL);
+        }
+
+        if (at_sync_sema) {
+            xSemaphoreGive(at_sync_sema);
+        }
+        return;
+    }
+    esp_netif_receive(s_netif, buffer, len, NULL);
+}
+
+static esp_err_t transmit(void *h, void *buffer, size_t len)
+{
+    printf("transmit: %d bytes\n", len);
+    esp_at_port_write_data(buffer, len);
+    return ESP_OK;
+}
+
+static uint8_t at_exe_cmd_test(uint8_t *cmd_name)
+{
+    uint8_t buffer[64] = {0};
+    snprintf((char *)buffer, 64, "execute command: <AT%s> is executed\r\n", cmd_name);
+    esp_at_port_write_data(buffer, strlen((char *)buffer));
+    printf("Command <AT%s> executed successfully\r\n", cmd_name);
+    if (!at_sync_sema) {
+        at_sync_sema = xSemaphoreCreateBinary();
+        assert(at_sync_sema != NULL);
+        esp_netif_driver_ifconfig_t driver_cfg = {
+            .handle = (void *)1,
+            .transmit = transmit,
+        };
+        const esp_netif_driver_ifconfig_t *ppp_driver_cfg = &driver_cfg;
+
+        esp_netif_inherent_config_t base_netif_cfg = ESP_NETIF_INHERENT_DEFAULT_PPP();
+        esp_netif_config_t netif_ppp_config = { .base = &base_netif_cfg,
+                                                .driver = ppp_driver_cfg,
+                                                .stack = ESP_NETIF_NETSTACK_DEFAULT_PPP
+                                              };
+
+        s_netif = esp_netif_new(&netif_ppp_config);
+        esp_netif_ppp_config_t netif_params;
+        ESP_ERROR_CHECK(esp_netif_ppp_get_params(s_netif, &netif_params));
+        netif_params.ppp_our_ip4_addr.addr = ESP_IP4TOADDR(192, 168, 11, 1);
+        netif_params.ppp_their_ip4_addr.addr = ESP_IP4TOADDR(192, 168, 11, 2);
+        netif_params.ppp_error_event_enabled = true;
+        ESP_ERROR_CHECK(esp_netif_ppp_set_params(s_netif, &netif_params));
+        if (esp_event_handler_register(IP_EVENT, ESP_EVENT_ANY_ID, on_ip_event, NULL) != ESP_OK) {
+            printf("Failed to register IP event handler");
+        }
+        if (esp_event_handler_register(NETIF_PPP_STATUS, ESP_EVENT_ANY_ID, on_ppp_event, NULL) !=  ESP_OK) {
+            printf("Failed to register NETIF_PPP_STATUS event handler");
+        }
+
+
+    }
+    esp_at_port_write_data((uint8_t *)"CONNECT\r\n", strlen("CONNECT\r\n"));
+
+    // set the callback function which will be called by AT port after receiving the input data
+    esp_at_port_enter_specific(wait_data_callback);
+    esp_netif_action_start(s_netif, 0, 0, 0);
+    esp_netif_action_connected(s_netif, 0, 0, 0);
+
+    while (xSemaphoreTake(at_sync_sema, pdMS_TO_TICKS(1000)) == pdFALSE) {
+        printf(".");
+    }
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_test_cereg(uint8_t *cmd_name)
+{
+    printf("%s: AT command <AT%s> is executed\r\n", __func__, cmd_name);
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_query_cereg(uint8_t *cmd_name)
+{
+    printf("%s: AT command <AT%s> is executed\r\n", __func__, cmd_name);
+    static uint8_t buffer[] = "+CEREG: 7,8\r\n";
+    esp_at_port_write_data(buffer, sizeof(buffer));
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_setup_cereg(uint8_t num)
+{
+    printf("%s: AT command <AT%d> is executed\r\n", __func__, num);
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_exe_cereg(uint8_t *cmd_name)
+{
+    printf("%s: AT command <AT%s> is executed\r\n", __func__, cmd_name);
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static esp_err_t hello_get_handler(httpd_req_t *req)
+{
+    const char* resp_str = "Hello from ESP-AT HTTP Server!";
+    httpd_resp_send(req, resp_str, HTTPD_RESP_USE_STRLEN);
+    return ESP_OK;
+}
+
+static esp_err_t root_get_handler(httpd_req_t *req)
+{
+    const char* resp_str = "ESP-AT HTTP Server is running";
+    httpd_resp_send(req, resp_str, HTTPD_RESP_USE_STRLEN);
+    return ESP_OK;
+}
+
+static esp_err_t test_get_handler(httpd_req_t *req)
+{
+    const char* resp_str = "{\"status\":\"success\",\"message\":\"Test endpoint working\",\"timestamp\":12345}";
+    httpd_resp_set_type(req, "application/json");
+    httpd_resp_send(req, resp_str, HTTPD_RESP_USE_STRLEN);
+    return ESP_OK;
+}
+
+static esp_err_t async_get_handler(httpd_req_t *req)
+{
+    printf("Starting async chunked response handler\r\n");
+
+    // Set content type for plain text response
+    httpd_resp_set_type(req, "text/plain");
+
+    // Static counter to track requests
+    static uint8_t req_count = 0;
+    req_count++;
+
+    // Send initial response with request count
+    char buffer[256];
+    snprintf(buffer, sizeof(buffer), "=== Async Response #%d ===\r\n", req_count);
+    httpd_resp_sendstr_chunk(req, buffer);
+
+    // Long message broken into chunks
+    const char* chunks[] = {
+        "This is a simulated slow server response.\r\n",
+        "Chunk 1: The ESP-AT HTTP server is demonstrating...\r\n",
+        "Chunk 2: ...asynchronous chunked transfer encoding...\r\n",
+        "Chunk 3: ...with artificial delays between chunks...\r\n",
+        "Chunk 4: ...to simulate real-world network conditions.\r\n",
+        "Chunk 5: Processing data... please wait...\r\n",
+        "Chunk 6: Still processing... almost done...\r\n",
+        "Chunk 7: Final chunk - transfer complete!\r\n",
+        "=== END OF RESPONSE ===\r\n"
+    };
+
+    int num_chunks = sizeof(chunks) / sizeof(chunks[0]);
+
+    // Send each chunk with delays
+    for (int i = 0; i < num_chunks; i++) {
+        // Add a delay to simulate slow processing
+        vTaskDelay(pdMS_TO_TICKS(1500)); // 1.5 second delay between chunks
+
+        // Add chunk number and timestamp
+        snprintf(buffer, sizeof(buffer), "[%d/%d] [%d ms] %s",
+                 i + 1, num_chunks, (int)(esp_timer_get_time() / 1000), chunks[i]);
+
+        printf("Sending chunk %d: %s", i + 1, chunks[i]);
+        httpd_resp_sendstr_chunk(req, buffer);
+    }
+
+    // Add final summary
+    vTaskDelay(pdMS_TO_TICKS(500));
+    snprintf(buffer, sizeof(buffer), "\r\nTransfer completed in %d chunks with delays.\r\n", num_chunks);
+    httpd_resp_sendstr_chunk(req, buffer);
+
+    // Send NULL to signal end of chunked transfer
+    httpd_resp_sendstr_chunk(req, NULL);
+
+    printf("Async chunked response completed\r\n");
+    return ESP_OK;
+}
+
+static const httpd_uri_t hello = {
+    .uri       = "/hello",
+    .method    = HTTP_GET,
+    .handler   = hello_get_handler,
+    .user_ctx  = NULL
+};
+
+static const httpd_uri_t root = {
+    .uri       = "/",
+    .method    = HTTP_GET,
+    .handler   = root_get_handler,
+    .user_ctx  = NULL
+};
+
+static const httpd_uri_t test = {
+    .uri       = "/test",
+    .method    = HTTP_GET,
+    .handler   = test_get_handler,
+    .user_ctx  = NULL
+};
+
+static const httpd_uri_t async_uri = {
+    .uri       = "/async",
+    .method    = HTTP_GET,
+    .handler   = async_get_handler,
+    .user_ctx  = NULL
+};
+
+static esp_err_t start_http_server(void)
+{
+    if (http_server != NULL) {
+        printf("HTTP server already running\r\n");
+        return ESP_OK;
+    }
+
+    httpd_config_t config = HTTPD_DEFAULT_CONFIG();
+    config.server_port = 8080;
+    config.lru_purge_enable = true;
+
+    printf("Starting HTTP server on port: %d\r\n", config.server_port);
+    if (httpd_start(&http_server, &config) == ESP_OK) {
+        printf("Registering URI handlers\r\n");
+        httpd_register_uri_handler(http_server, &hello);
+        httpd_register_uri_handler(http_server, &root);
+        httpd_register_uri_handler(http_server, &test);
+        httpd_register_uri_handler(http_server, &async_uri);
+        return ESP_OK;
+    }
+
+    printf("Error starting HTTP server!\r\n");
+    return ESP_FAIL;
+}
+
+static esp_err_t stop_http_server(void)
+{
+    if (http_server != NULL) {
+        httpd_stop(http_server);
+        http_server = NULL;
+        printf("HTTP server stopped\r\n");
+        return ESP_OK;
+    }
+    return ESP_OK;
+}
+
+/* HTTP Server AT Commands */
+static uint8_t at_test_httpd(uint8_t *cmd_name)
+{
+    uint8_t buffer[64] = {0};
+    snprintf((char *)buffer, 64, "AT%s=<0/1> - Start/Stop HTTP server\r\n", cmd_name);
+    esp_at_port_write_data(buffer, strlen((char *)buffer));
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_query_httpd(uint8_t *cmd_name)
+{
+    uint8_t buffer[64] = {0};
+    snprintf((char *)buffer, 64, "+HTTPD:%d\r\n", http_server != NULL ? 1 : 0);
+    esp_at_port_write_data(buffer, strlen((char *)buffer));
+    return ESP_AT_RESULT_CODE_OK;
+}
+
+static uint8_t at_setup_httpd(uint8_t para_num)
+{
+    int32_t action = 0;
+    if (esp_at_get_para_as_digit(0, &action) != ESP_AT_PARA_PARSE_RESULT_OK) {
+        return ESP_AT_RESULT_CODE_ERROR;
+    }
+
+    if (action == 1) {
+        if (start_http_server() == ESP_OK) {
+            printf("HTTP server started successfully\r\n");
+            return ESP_AT_RESULT_CODE_OK;
+        }
+    } else if (action == 0) {
+        if (stop_http_server() == ESP_OK) {
+            return ESP_AT_RESULT_CODE_OK;
+        }
+    }
+
+    return ESP_AT_RESULT_CODE_ERROR;
+}
+
+static uint8_t at_exe_httpd(uint8_t *cmd_name)
+{
+    // Default action: start server
+    if (start_http_server() == ESP_OK) {
+        printf("HTTP server started via execute command\r\n");
+        return ESP_AT_RESULT_CODE_OK;
+    }
+    return ESP_AT_RESULT_CODE_ERROR;
+}
+
+
+static const esp_at_cmd_struct at_custom_cmd[] = {
+    {"+PPPD", at_test_cmd_test, at_query_cmd_test, at_setup_cmd_test, at_exe_cmd_test},
+    {"+CEREG", at_test_cereg, at_query_cereg, at_setup_cereg, at_exe_cereg},
+    {"+HTTPD", at_test_httpd, at_query_httpd, at_setup_httpd, at_exe_httpd},
+};
+
+bool esp_at_custom_cmd_register(void)
+{
+    return esp_at_custom_cmd_array_regist(at_custom_cmd, sizeof(at_custom_cmd) / sizeof(esp_at_cmd_struct));
+}
+
+ESP_AT_CMD_SET_INIT_FN(esp_at_custom_cmd_register, 1);

common_components/modem_sim/pppd_cmd/include/at_custom_cmd.h

@@ -0,0 +1,12 @@
+/*
+ * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+#pragma once
+#include "esp_at_core.h"
+#include "esp_at.h"
+
+/**
+ * @brief You can include more header files here for your own AT commands.
+ */

common_components/modem_sim/sdkconfig.defaults

@@ -0,0 +1,79 @@
+# This file was generated using idf.py save-defconfig. It can be edited manually.
+# Espressif IoT Development Framework (ESP-IDF) 5.4.1 Project Minimal Configuration
+#
+CONFIG_BOOTLOADER_APP_ROLLBACK_ENABLE=y
+CONFIG_APP_PROJECT_VER_FROM_CONFIG=y
+CONFIG_APP_PROJECT_VER="v4.1.0.0-dev"
+CONFIG_ESPTOOLPY_FLASHSIZE_4MB=y
+CONFIG_PARTITION_TABLE_CUSTOM=y
+CONFIG_PARTITION_TABLE_CUSTOM_FILENAME="module_config/module_esp32_default/partitions_at.csv"
+CONFIG_PARTITION_TABLE_MD5=n
+CONFIG_AT_CUSTOMIZED_PARTITION_TABLE_FILE="module_config/module_esp32_default/at_customize.csv"
+CONFIG_BT_ENABLED=y
+CONFIG_BT_BTU_TASK_STACK_SIZE=5120
+CONFIG_BT_BLE_BLUFI_ENABLE=y
+CONFIG_BT_STACK_NO_LOG=y
+CONFIG_BT_BLE_DYNAMIC_ENV_MEMORY=y
+CONFIG_BTDM_CTRL_MODE_BTDM=y
+CONFIG_BTDM_CTRL_LPCLK_SEL_EXT_32K_XTAL=y
+CONFIG_BTDM_SCAN_DUPL_CACHE_SIZE=200
+CONFIG_ESP_TLS_PSK_VERIFICATION=y
+CONFIG_ESP_TLS_INSECURE=y
+CONFIG_ESP_TLS_SKIP_SERVER_CERT_VERIFY=y
+CONFIG_ESP_ERR_TO_NAME_LOOKUP=n
+CONFIG_GPIO_ESP32_SUPPORT_SWITCH_SLP_PULL=y
+CONFIG_ETH_DMA_RX_BUFFER_NUM=3
+CONFIG_ETH_DMA_TX_BUFFER_NUM=3
+CONFIG_HTTPD_MAX_REQ_HDR_LEN=1024
+CONFIG_HTTPD_MAX_URI_LEN=1024
+CONFIG_ESP_HTTPS_OTA_ALLOW_HTTP=y
+CONFIG_RTC_CLK_SRC_EXT_CRYS=y
+CONFIG_RTC_EXT_CRYST_ADDIT_CURRENT=y
+CONFIG_RTC_CLK_CAL_CYCLES=1024
+CONFIG_PM_ENABLE=y
+CONFIG_PM_SLP_DISABLE_GPIO=y
+CONFIG_ESP_DEFAULT_CPU_FREQ_MHZ_80=y
+CONFIG_ESP_TASK_WDT_PANIC=y
+CONFIG_ESP_TASK_WDT_TIMEOUT_S=60
+CONFIG_ESP_DEBUG_OCDAWARE=n
+CONFIG_ESP_WIFI_IRAM_OPT=n
+CONFIG_ESP_WIFI_RX_IRAM_OPT=n
+CONFIG_ESP_WIFI_SLP_IRAM_OPT=y
+CONFIG_ESP_WIFI_SLP_BEACON_LOST_OPT=y
+CONFIG_ESP_WIFI_ESPNOW_MAX_ENCRYPT_NUM=0
+CONFIG_FATFS_LFN_HEAP=y
+CONFIG_FREERTOS_UNICORE=y
+CONFIG_FREERTOS_HZ=1000
+CONFIG_FREERTOS_USE_TICKLESS_IDLE=y
+CONFIG_FREERTOS_CHECK_MUTEX_GIVEN_BY_OWNER=n
+CONFIG_FREERTOS_PLACE_FUNCTIONS_INTO_FLASH=y
+CONFIG_HEAP_PLACE_FUNCTION_INTO_FLASH=y
+CONFIG_LOG_DEFAULT_LEVEL_ERROR=y
+CONFIG_LWIP_MAX_SOCKETS=16
+CONFIG_LWIP_SO_LINGER=y
+CONFIG_LWIP_SO_RCVBUF=y
+CONFIG_LWIP_IP4_REASSEMBLY=y
+CONFIG_LWIP_IP6_REASSEMBLY=y
+CONFIG_LWIP_IPV6_AUTOCONFIG=y
+CONFIG_LWIP_TCP_MAXRTX=6
+CONFIG_LWIP_TCP_SYNMAXRTX=3
+CONFIG_LWIP_PPP_SUPPORT=y
+CONFIG_LWIP_PPP_SERVER_SUPPORT=y
+CONFIG_LWIP_SNTP_MAX_SERVERS=3
+CONFIG_LWIP_SNTP_STARTUP_DELAY=n
+CONFIG_MBEDTLS_DYNAMIC_BUFFER=y
+CONFIG_MBEDTLS_DYNAMIC_FREE_CONFIG_DATA=y
+CONFIG_MBEDTLS_SSL_KEEP_PEER_CERTIFICATE=n
+CONFIG_MBEDTLS_HAVE_TIME_DATE=y
+CONFIG_MBEDTLS_DHM_C=y
+CONFIG_NEWLIB_NANO_FORMAT=y
+CONFIG_VFS_SUPPORT_TERMIOS=n
+CONFIG_WL_SECTOR_SIZE_512=y
+CONFIG_AT_PROCESS_TASK_STACK_SIZE=6144
+CONFIG_AT_MQTT_COMMAND_SUPPORT=y
+CONFIG_AT_HTTP_COMMAND_SUPPORT=y
+CONFIG_AT_BLE_COMMAND_SUPPORT=n
+CONFIG_AT_BLE_HID_COMMAND_SUPPORT=n
+CONFIG_AT_BLUFI_COMMAND_SUPPORT=n
+CONFIG_LWIP_IP_FORWARD=y
+CONFIG_LWIP_IPV4_NAPT=y

components/asio/port/src/asio_stub.cpp

@@ -28,7 +28,7 @@ posix_event::posix_event()
 }
 } // namespace asio::detail
 
-extern "C" int pause (void)
+extern "C" int pause(void)
 {
     while (true) {
         ::sleep(UINT_MAX);

components/eppp_link/.cz.yaml

@@ -3,6 +3,6 @@ commitizen:
   bump_message: 'bump(eppp): $current_version -> $new_version'
   pre_bump_hooks: python ../../ci/changelog.py eppp_link
   tag_format: eppp-v$version
-  version: 0.3.0
+  version: 1.1.3
   version_files:
   - idf_component.yml

components/eppp_link/CHANGELOG.md

@@ -1,5 +1,58 @@
 # Changelog
 
+## [1.1.3](https://github.com/espressif/esp-protocols/commits/eppp-v1.1.3)
+
+### Bug Fixes
+
+- Fix test dependency issue on driver ([1ace92c2](https://github.com/espressif/esp-protocols/commit/1ace92c2))
+- Fix tun netif to (optionally) return errors ([7a6cf0f9](https://github.com/espressif/esp-protocols/commit/7a6cf0f9))
+
+## [1.1.2](https://github.com/espressif/esp-protocols/commits/eppp-v1.1.2)
+
+### Bug Fixes
+
+- Update uart driver deps per IDF > v5.3 ([92e14607](https://github.com/espressif/esp-protocols/commit/92e14607))
+
+## [1.1.1](https://github.com/espressif/esp-protocols/commits/eppp-v1.1.1)
+
+### Bug Fixes
+
+- Fix getting context for channel API ([94563cdc](https://github.com/espressif/esp-protocols/commit/94563cdc))
+- Cover more combinations in build tests ([e0b8de8f](https://github.com/espressif/esp-protocols/commit/e0b8de8f))
+
+## [1.1.0](https://github.com/espressif/esp-protocols/commits/eppp-v1.1.0)
+
+### Features
+
+- Add support for UART flow control ([cd57f1bb](https://github.com/espressif/esp-protocols/commit/cd57f1bb), [#870](https://github.com/espressif/esp-protocols/issues/870))
+
+### Bug Fixes
+
+- Fix SPI transport to allow already init GPIO ISR ([497ee2d6](https://github.com/espressif/esp-protocols/commit/497ee2d6), [#868](https://github.com/espressif/esp-protocols/issues/868))
+- Fix stack-overflow in ping task for TUN netif ([b2568a3d](https://github.com/espressif/esp-protocols/commit/b2568a3d), [#867](https://github.com/espressif/esp-protocols/issues/867))
+
+### Updated
+
+- ci(common): Update test component dir for IDFv6.0 ([18418c83](https://github.com/espressif/esp-protocols/commit/18418c83))
+
+## [1.0.1](https://github.com/espressif/esp-protocols/commits/eppp-v1.0.1)
+
+### Bug Fixes
+
+- Support for IPv4-only mode ([653328ba](https://github.com/espressif/esp-protocols/commit/653328ba), [#864](https://github.com/espressif/esp-protocols/issues/864))
+
+## [1.0.0](https://github.com/espressif/esp-protocols/commits/eppp-v1.0.0)
+
+### Features
+
+- Add support for custom channels ([4ee9360f](https://github.com/espressif/esp-protocols/commit/4ee9360f))
+
+## [0.3.1](https://github.com/espressif/esp-protocols/commits/eppp-v0.3.1)
+
+### Bug Fixes
+
+- Fix NETIF_PPP_STATUS link issue if PPP disabled in lwip ([077ea0bb](https://github.com/espressif/esp-protocols/commit/077ea0bb))
+
 ## [0.3.0](https://github.com/espressif/esp-protocols/commits/eppp-v0.3.0)
 
 ### Features

components/eppp_link/CMakeLists.txt

@@ -1,5 +1,5 @@
 if("${IDF_VERSION_MAJOR}.${IDF_VERSION_MINOR}" VERSION_GREATER "5.3")
-    set(driver_deps esp_driver_gpio esp_driver_spi)
+    set(driver_deps esp_driver_gpio esp_driver_spi esp_driver_uart esp_driver_sdio)
 else()
     set(driver_deps driver)
 endif()

components/eppp_link/Kconfig

@@ -93,4 +93,21 @@ menu "eppp_link"
         default "06:00:00:00:00:02"
         depends on EPPP_LINK_DEVICE_ETH
 
+    config EPPP_LINK_CHANNELS_SUPPORT
+        bool "Enable channel support (multiple logical channels)"
+        default n
+        depends on !EPPP_LINK_DEVICE_ETH
+        help
+            Enable support for multiple logical channels in the EPPP link layer.
+            When enabled, you can configure the number of channels used for communication.
+
+    config EPPP_LINK_NR_OF_CHANNELS
+        int "Number of logical channels"
+        depends on EPPP_LINK_CHANNELS_SUPPORT && !EPPP_LINK_DEVICE_ETH
+        range 1 8
+        default 2
+        help
+            Set the number of logical channels for EPPP link communication.
+            Each channel can be used for independent data streams.
+
 endmenu

components/eppp_link/README.md

@@ -1,7 +1,7 @@
 # ESP PPP Link component (eppp_link)
 
 The component provides a general purpose connectivity engine between two microcontrollers, one acting as PPP server, the other one as PPP client.
-This component could be used for extending network using physical serial connection. Applications could vary from providing PRC engine for multiprocessor solutions to serial connection to POSIX machine. This uses a standard PPP protocol (if enabled) to negotiate IP addresses and networking, so standard PPP toolset could be used, e.g. a `pppd` service on linux. Typical application is a WiFi connectivity provider for chips that do not have WiFi.
+This component could be used for extending network using physical serial connection. Applications could vary from providing RPC engine for multiprocessor solutions to serial connection to POSIX machine. This uses a standard PPP protocol (if enabled) to negotiate IP addresses and networking, so standard PPP toolset could be used, e.g. a `pppd` service on linux. Typical application is a WiFi connectivity provider for chips that do not have WiFi.
 Uses simplified TUN network interface by default to enable faster data transfer on non-UART transports.
 
 ## Typical application
@@ -21,6 +21,27 @@ brings in the WiFi connectivity from the communication coprocessor.
          +----------------+                               +----------------+
 ```
 
+## Features
+
+### Network Interface Modes
+
+Standard PPP Mode (where PPP protocols is preferred) or simple tunnel using TUN Mode.
+
+### Transport layer
+
+UART, SPI, SDIO, Ethernet
+
+### Support for logical channels
+
+Allows channeling custom data (e.g. 802.11 frames)
+
+## (Other) usecases
+
+Besides the communication coprocessor example mentioned above, this component could be used to:
+* Bring Wi-Fi connectivity to a computer using ESP32 chip.
+* Connect your microcontroller to the internet via a pppd server (running on a raspberry)
+* Bridging two networks with two microcontrollers
+
 ## Configuration
 
 ### Choose the transport layer
@@ -39,6 +60,14 @@ Use `idf.py menuconfig` to select the transport layer:
 
 Use PPP netif for UART; Keep the default (TUN) for others
 
+### Channel support (multiple logical channels)
+
+* `CONFIG_EPPP_LINK_CHANNELS_SUPPORT` -- Enable support for multiple logical channels (default: disabled)
+* `CONFIG_EPPP_LINK_NR_OF_CHANNELS` -- Number of logical channels (default: 2, range: 1-8, only visible if channel support is enabled)
+
+When channel support is enabled, the EPPP link can multiplex multiple logical data streams over the same transport. The number of channels is configurable. Channel support is not available for Ethernet transport.
+
+To use channels in your application, use the `eppp_add_channels()` API and provide your own channel transmit/receive callbacks. These APIs and related types are only available when channel support is enabled in Kconfig.
 
 ## API
 
@@ -57,6 +86,9 @@ Use PPP netif for UART; Keep the default (TUN) for others
 * `eppp_netif_start()` -- Starts the network, could be called after startup or whenever a connection is lost
 * `eppp_netif_stop()` --  Stops the network
 * `eppp_perform()` -- Perform one iteration of the PPP task (need to be called regularly in task-less configuration)
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+* `eppp_add_channels()` -- Register channel transmit/receive callbacks (only available if channel support is enabled)
+#endif
 
 ## Throughput
 

components/eppp_link/detailed_description.md

@@ -0,0 +1,370 @@
+# ESP PPP Link Component (eppp_link) - Detailed Documentation
+
+## Overview
+
+The ESP PPP Link component provides a versatile communication bridge between two ESP32 microcontrollers, enabling network connectivity over various physical transport layers. One device acts as a server (typically providing connectivity), while the other acts as a client (consuming connectivity).
+
+## Network Interface Modes
+
+### PPP Mode vs TUN Mode
+
+The component supports two distinct network interface modes:
+
+#### PPP Mode (`CONFIG_EPPP_LINK_USES_PPP=y`)
+- **Standard PPP Protocol**: Uses the Point-to-Point Protocol (RFC 1661) with full LCP negotiation
+- **Compatibility**: Compatible with standard PPP implementations like Linux `pppd`
+- **Features**:
+  - Automatic IP address negotiation
+  - Link Control Protocol (LCP) for connection establishment
+  - Authentication support (if configured)
+  - Standard PPP framing with escape sequences
+- **Use Case**: When interfacing with standard PPP-capable systems or when full PPP compatibility is required
+- **Transport Limitation**: Primarily designed for UART transport due to PPP's serial nature
+
+#### TUN Mode (`CONFIG_EPPP_LINK_USES_PPP=n`, default)
+- **Simplified Packet Interface**: Uses a custom packet-based protocol without PPP negotiation
+- **Performance**: Faster data transfer due to reduced protocol overhead
+- **Features**:
+  - Direct IP packet transmission
+  - Custom framing for packet boundaries
+  - No negotiation overhead
+  - Static IP address configuration
+- **Use Case**: Default mode for ESP-to-ESP communication, optimal for non-UART transports
+- **Transport Support**: Works efficiently with all transport types (UART, SPI, SDIO, Ethernet)
+
+**Mode Selection**: Configure via `idf.py menuconfig` → `Component config` → `eppp_link` → `Use PPP network interface`
+
+## Transport Layer Options
+
+### UART Transport
+- **Configuration**: `CONFIG_EPPP_LINK_DEVICE_UART=y`
+- **Features**:
+  - Simple serial communication
+  - Configurable baud rate (up to 3Mbps tested)
+  - Hardware flow control support
+  - Custom framing for packet boundaries in TUN mode
+- **Performance**: ~2 Mbps (TCP/UDP) @ 3 Mbaud
+- **Use Case**: Basic connectivity, long-distance communication, debugging
+- **Pins**: TX, RX configurable
+
+```c
+eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+config.transport = EPPP_TRANSPORT_UART;
+config.uart.tx_io = 25;
+config.uart.rx_io = 26;
+config.uart.baud = 921600;
+```
+
+### SPI Transport
+- **Configuration**: `CONFIG_EPPP_LINK_DEVICE_SPI=y`
+- **Features**:
+  - Master/slave configuration
+  - GPIO interrupt signaling for flow control
+  - Configurable clock frequency
+  - Full-duplex communication
+  - Packet queue for transmission
+- **Performance**: ~5 Mbps (TCP), ~8 Mbps (UDP) @ 16MHz
+- **Use Case**: High-speed local communication, PCB-level connections
+- **Pins**: MOSI, MISO, SCLK, CS, interrupt GPIO
+
+```c
+eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+config.transport = EPPP_TRANSPORT_SPI;
+config.spi.is_master = true;
+config.spi.freq = 16000000;
+config.spi.mosi = 11;
+config.spi.miso = 13;
+config.spi.sclk = 12;
+config.spi.cs = 10;
+config.spi.intr = 2;
+```
+
+### SDIO Transport
+- **Configuration**: `CONFIG_EPPP_LINK_DEVICE_SDIO=y`
+- **Features**:
+  - Host/slave configuration
+  - High-speed data transfer
+  - 1-bit or 4-bit bus width
+  - Hardware flow control
+- **Performance**: ~9 Mbps (TCP), ~11 Mbps (UDP)
+- **Use Case**: Highest throughput applications, module-to-module communication
+- **Pins**: CLK, CMD, D0-D3 (configurable width)
+
+```c
+eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+config.transport = EPPP_TRANSPORT_SDIO;
+config.sdio.is_host = true;
+config.sdio.width = 4;
+config.sdio.clk = 18;
+config.sdio.cmd = 19;
+config.sdio.d0 = 14;
+// ... additional data pins
+```
+
+### Ethernet Transport
+- **Configuration**: `CONFIG_EPPP_LINK_DEVICE_ETH=y`
+- **Features**:
+  - Direct MAC-to-MAC communication
+  - Can work with or without PHY chips
+  - Standard Ethernet framing
+  - Automatic task management (no `eppp_perform()` needed)
+- **Performance**: ~5 Mbps (TCP), ~8 Mbps (UDP) with internal EMAC
+- **Use Case**: Board-to-board communication, integration with existing Ethernet infrastructure
+- **Pins**: MDC, MDIO, plus PHY-specific pins
+
+```c
+eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+config.transport = EPPP_TRANSPORT_ETHERNET;
+config.ethernet.mdc_io = 23;
+config.ethernet.mdio_io = 18;
+config.ethernet.phy_addr = 1;
+config.ethernet.rst_io = 5;
+```
+
+## Channel Support (Multiple Logical Channels)
+
+### Overview
+Channel support allows multiplexing multiple independent data streams over a single transport connection. This enables applications to separate different types of data (e.g., network traffic, control commands, sensor data) into distinct logical channels.
+
+### Configuration
+- **Enable**: `CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y`
+- **Count**: `CONFIG_EPPP_LINK_NR_OF_CHANNELS` (1-8 channels, default 2)
+- **Limitation**: Not available for Ethernet transport
+
+### Channel Usage
+```c
+// Channel callback function type
+typedef esp_err_t (*eppp_channel_fn_t)(esp_netif_t *netif, int nr, void *buffer, size_t len);
+
+// Register channel callbacks
+esp_err_t eppp_add_channels(esp_netif_t *netif,
+                           eppp_channel_fn_t *tx,     // Transmit function pointer (output)
+                           const eppp_channel_fn_t rx, // Receive callback (input)
+                           void* context);             // User context
+
+// Get user context
+void* eppp_get_context(esp_netif_t *netif);
+```
+
+### Channel Example
+```c
+// Channel 0: Default network traffic (handled automatically)
+// Channel 1: Control/chat messages
+// Channel 2: WiFi data forwarding
+
+static esp_err_t channel_receive(esp_netif_t *netif, int channel, void *buffer, size_t len)
+{
+    switch(channel) {
+        case 1: // Control channel
+            process_control_message(buffer, len);
+            break;
+        case 2: // WiFi channel
+            forward_to_wifi(buffer, len);
+            break;
+        default:
+            ESP_LOGE(TAG, "Unknown channel %d", channel);
+            return ESP_FAIL;
+    }
+    return ESP_OK;
+}
+
+// Register channels
+eppp_channel_fn_t tx_func;
+eppp_add_channels(netif, &tx_func, channel_receive, user_context);
+
+// Transmit on specific channel
+tx_func(netif, 1, "Hello", 5);  // Send to channel 1
+```
+
+## API Reference
+
+### Simple API (Recommended for most use cases)
+
+#### Client Side
+```c
+esp_netif_t *eppp_connect(eppp_config_t *config);
+```
+- **Purpose**: Simplified client connection
+- **Behavior**: Blocks until connection is established
+- **Returns**: Configured network interface or NULL on failure
+- **Use Case**: Simple applications that don't need fine-grained control
+
+#### Server Side
+```c
+esp_netif_t *eppp_listen(eppp_config_t *config);
+```
+- **Purpose**: Simplified server listening
+- **Behavior**: Blocks until client connects
+- **Returns**: Configured network interface or NULL on failure
+- **Use Case**: Simple applications that don't need fine-grained control
+
+#### Connection Management
+```c
+void eppp_close(esp_netif_t *netif);
+```
+- **Purpose**: Close connection and cleanup resources
+- **Behavior**: Stops tasks, closes transport, destroys network interface
+
+### Advanced API (Manual Control)
+
+#### Initialization
+```c
+esp_netif_t *eppp_init(eppp_type_t role, eppp_config_t *config);
+```
+- **Purpose**: Initialize endpoint without starting communication
+- **Parameters**:
+  - `role`: `EPPP_SERVER` or `EPPP_CLIENT`
+  - `config`: Transport and network configuration
+- **Returns**: Network interface handle
+- **Use Case**: Applications needing manual control over connection lifecycle
+
+#### Connection Control
+```c
+esp_err_t eppp_netif_start(esp_netif_t *netif);
+esp_err_t eppp_netif_stop(esp_netif_t *netif, int stop_timeout_ms);
+```
+- **Purpose**: Manual network interface start/stop
+- **Use Case**: Dynamic connection management, error recovery
+
+#### Task Management
+```c
+esp_err_t eppp_perform(esp_netif_t *netif);
+```
+- **Purpose**: Single iteration of communication task
+- **Returns**:
+  - `ESP_OK`: Continue operation
+  - `ESP_FAIL`: Operation failed but should continue
+  - `ESP_ERR_TIMEOUT`: Stop operation requested
+- **Use Case**: Task-less operation, integration with custom task schedulers
+- **Note**: Not needed for Ethernet transport (has its own task)
+
+#### Resource Management
+```c
+void eppp_deinit(esp_netif_t *netif);
+```
+- **Purpose**: Clean up resources without stopping tasks
+- **Use Case**: Manual resource management
+
+## Configuration Examples
+
+### Basic Client-Server Setup
+
+**Client (Host) Configuration:**
+```c
+void app_main(void)
+{
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+    config.transport = EPPP_TRANSPORT_UART;
+    config.uart.tx_io = 25;
+    config.uart.rx_io = 26;
+    config.uart.baud = 921600;
+
+    esp_netif_t *netif = eppp_connect(&config);
+    if (netif == NULL) {
+        ESP_LOGE(TAG, "Failed to connect");
+        return;
+    }
+
+    ESP_LOGI(TAG, "Connected successfully");
+    // Use network interface for communication
+}
+```
+
+**Server (Slave) Configuration:**
+```c
+void app_main(void)
+{
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    // Initialize WiFi or other network interface
+    init_wifi();
+
+    eppp_config_t config = EPPP_DEFAULT_SERVER_CONFIG();
+    config.transport = EPPP_TRANSPORT_UART;
+    config.uart.tx_io = 26;  // Crossed with client
+    config.uart.rx_io = 25;  // Crossed with client
+    config.uart.baud = 921600;
+
+    esp_netif_t *netif = eppp_listen(&config);
+    if (netif == NULL) {
+        ESP_LOGE(TAG, "Failed to setup server");
+        return;
+    }
+
+    // Enable NAT to share WiFi connection
+    ESP_ERROR_CHECK(esp_netif_napt_enable(netif));
+    ESP_LOGI(TAG, "Server ready");
+}
+```
+
+### Advanced Manual Control
+```c
+void app_main(void)
+{
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+
+    eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+    config.task.run_task = false;  // Disable automatic task
+
+    esp_netif_t *netif = eppp_init(EPPP_CLIENT, &config);
+    if (netif == NULL) {
+        ESP_LOGE(TAG, "Failed to initialize");
+        return;
+    }
+
+    // Start network interface
+    ESP_ERROR_CHECK(eppp_netif_start(netif));
+
+    // Custom task loop
+    while (true) {
+        esp_err_t ret = eppp_perform(netif);
+        if (ret == ESP_ERR_TIMEOUT) {
+            ESP_LOGI(TAG, "Operation stopped");
+            break;
+        } else if (ret != ESP_OK) {
+            ESP_LOGE(TAG, "Operation failed: %s", esp_err_to_name(ret));
+        }
+
+        // Add custom processing here
+        vTaskDelay(pdMS_TO_TICKS(1));
+    }
+
+    eppp_deinit(netif);
+}
+```
+
+### Multi-Channel Configuration
+```c
+typedef struct {
+    eppp_channel_fn_t tx_func;
+    esp_netif_t *netif;
+} channel_context_t;
+
+static esp_err_t channel_rx(esp_netif_t *netif, int channel, void *buffer, size_t len)
+{
+    ESP_LOGI(TAG, "Channel %d received %d bytes", channel, len);
+    // Process channel data based on channel number
+    return ESP_OK;
+}
+
+void setup_channels(void)
+{
+    eppp_config_t config = EPPP_DEFAULT_CLIENT_CONFIG();
+    esp_netif_t *netif = eppp_connect(&config);
+
+    channel_context_t *ctx = calloc(1, sizeof(channel_context_t));
+    ctx->netif = netif;
+
+    // Register channel callbacks
+    ESP_ERROR_CHECK(eppp_add_channels(netif, &ctx->tx_func, channel_rx, ctx));
+
+    // Send data on channel 1
+    const char *msg = "Hello on channel 1";
+    ctx->tx_func(netif, 1, (void*)msg, strlen(msg));
+}
+```

components/eppp_link/eppp_link.c

@@ -163,6 +163,7 @@ static int get_netif_num(esp_netif_t *netif)
     return  netif_cnt;
 }
 
+#ifdef CONFIG_EPPP_LINK_USES_PPP
 static void on_ppp_event(void *arg, esp_event_base_t base, int32_t event_id, void *data)
 {
     esp_netif_t **netif = data;
@@ -172,6 +173,7 @@ static void on_ppp_event(void *arg, esp_event_base_t base, int32_t event_id, voi
         h->netif_stop = true;
     }
 }
+#endif // CONFIG_EPPP_LINK_USES_PPP
 
 static void on_ip_event(void *arg, esp_event_base_t base, int32_t event_id, void *data)
 {
@@ -222,7 +224,9 @@ static void remove_handlers(void)
         vEventGroupDelete(s_event_group);
         s_event_group = NULL;
         esp_event_handler_unregister(IP_EVENT, ESP_EVENT_ANY_ID, on_ip_event);
+#ifdef CONFIG_EPPP_LINK_USES_PPP
         esp_event_handler_unregister(NETIF_PPP_STATUS, ESP_EVENT_ANY_ID, on_ppp_event);
+#endif
     }
 }
 
@@ -296,11 +300,13 @@ esp_netif_t *eppp_open(eppp_type_t role, eppp_config_t *config, int connect_time
             remove_handlers();
             return NULL;
         }
+#ifdef CONFIG_EPPP_LINK_USES_PPP
         if (esp_event_handler_register(NETIF_PPP_STATUS, ESP_EVENT_ANY_ID, on_ppp_event, NULL) !=  ESP_OK) {
             ESP_LOGE(TAG, "Failed to register PPP status handler");
             remove_handlers();
             return NULL;
         }
+#endif // CONFIG_EPPP_LINK_USES_PPP
     }
     esp_netif_t *netif = eppp_init(role, config);
     if (!netif) {
@@ -361,3 +367,24 @@ void eppp_close(esp_netif_t *netif)
     eppp_deinit(netif);
     remove_handlers();
 }
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+esp_err_t eppp_add_channels(esp_netif_t *netif, eppp_channel_fn_t *tx, const eppp_channel_fn_t rx, void* context)
+{
+    ESP_RETURN_ON_FALSE(netif != NULL && tx != NULL && rx != NULL, ESP_ERR_INVALID_ARG, TAG, "Invalid arguments");
+    struct eppp_handle *h = esp_netif_get_io_driver(netif);
+    ESP_RETURN_ON_FALSE(h != NULL && h->channel_tx != NULL, ESP_ERR_INVALID_STATE, TAG, "Transport not initialized");
+    *tx = h->channel_tx;
+    h->channel_rx = rx;
+    h->context = context;
+    return ESP_OK;
+}
+
+void* eppp_get_context(esp_netif_t *netif)
+{
+    ESP_RETURN_ON_FALSE(netif != NULL, NULL, TAG, "Invalid netif");
+    struct eppp_handle *h = esp_netif_get_io_driver(netif);
+    ESP_RETURN_ON_FALSE(h != NULL, NULL, TAG, "EPPP Not initialized");
+    return h->context;
+}
+#endif

components/eppp_link/eppp_netif_tun.c

@@ -17,9 +17,17 @@
 #include "esp_check.h"
 #include "esp_idf_version.h"
 
+#if defined(CONFIG_ESP_NETIF_RECEIVE_REPORT_ERRORS)
+typedef esp_err_t esp_netif_recv_ret_t;
+#define ESP_NETIF_OPTIONAL_RETURN_CODE(expr) expr
+#else
+typedef void esp_netif_recv_ret_t;
+#define ESP_NETIF_OPTIONAL_RETURN_CODE(expr)
+#endif // CONFIG_ESP_NETIF_RECEIVE_REPORT_ERRORS
+
 static const char *TAG = "eppp_tun_netif";
 
-static void tun_input(void *h, void *buffer, unsigned int len, void *eb)
+static esp_netif_recv_ret_t tun_input(void *h, void *buffer, unsigned int len, void *eb)
 {
     __attribute__((unused)) esp_err_t ret = ESP_OK;
     struct netif *netif = h;
@@ -31,11 +39,12 @@ static void tun_input(void *h, void *buffer, unsigned int len, void *eb)
     ESP_GOTO_ON_FALSE(pbuf_remove_header(p, SIZEOF_ETH_HDR) == 0, ESP_FAIL, err, TAG, "pbuf_remove_header failed");
     memcpy(p->payload, buffer, len);
     ESP_GOTO_ON_FALSE(netif->input(p, netif) == ERR_OK, ESP_FAIL, err, TAG, "failed to input packet to lwip");
-    return;
+    return ESP_NETIF_OPTIONAL_RETURN_CODE(ESP_OK);
 err:
     if (p) {
         pbuf_free(p);
     }
+    return ESP_NETIF_OPTIONAL_RETURN_CODE(ret);
 }
 
 static err_t tun_output(struct netif *netif, struct pbuf *p)
@@ -65,12 +74,13 @@ static err_t tun_output_v4(struct netif *netif, struct pbuf *p, const ip4_addr_t
     LWIP_UNUSED_ARG(ipaddr);
     return tun_output(netif, p);
 }
+#if LWIP_IPV6
 static err_t tun_output_v6(struct netif *netif, struct pbuf *p, const ip6_addr_t *ipaddr)
 {
     LWIP_UNUSED_ARG(ipaddr);
     return tun_output(netif, p);
 }
-
+#endif
 static err_t tun_init(struct netif *netif)
 {
     if (netif == NULL) {
@@ -151,9 +161,12 @@ static void cmd_ping_on_ping_end(esp_ping_handle_t hdl, void *args)
     }
     if (IP_IS_V4(&target_addr)) {
         ESP_LOGD(TAG, "\n--- %s ping statistics ---\n", inet_ntoa(*ip_2_ip4(&target_addr)));
-    } else {
+    }
+#if LWIP_IPV6
+    else {
         ESP_LOGD(TAG, "\n--- %s ping statistics ---\n", inet6_ntoa(*ip_2_ip6(&target_addr)));
     }
+#endif
     ESP_LOGI(TAG, "%" PRIu32 " packets transmitted, %" PRIu32 " received, %" PRIu32 "%% packet loss, time %" PRIu32 "ms\n",
              transmitted, received, loss, total_time_ms);
     esp_ping_delete_session(hdl);
@@ -163,12 +176,19 @@ esp_err_t eppp_check_connection(esp_netif_t *netif)
 {
     esp_err_t ret = ESP_OK;
     esp_ping_config_t config = ESP_PING_DEFAULT_CONFIG();
+#if CONFIG_LOG_MAXIMUM_LEVEL > 3
+    config.task_stack_size += 1024;  // Some additional stack needed for verbose logs
+#endif
     config.count = 100;
     ESP_LOGI(TAG, "Checking connection on EPPP interface #%" PRIu32, config.interface);
     ip_addr_t target_addr = {0};
     esp_netif_ip_info_t ip;
     esp_netif_get_ip_info(netif, &ip);
+#if LWIP_IPV6
     target_addr.u_addr.ip4.addr =  ip.gw.addr;
+#else
+    target_addr.addr =  ip.gw.addr;
+#endif
     config.target_addr = target_addr;
     esp_ping_callbacks_t cbs = {
         .cb_args = netif,

components/eppp_link/eppp_sdio.c

@@ -13,6 +13,7 @@
 #include "eppp_link.h"
 #include "eppp_transport.h"
 #include "eppp_transport_sdio.h"
+#include "eppp_sdio.h"
 
 #define TAG "eppp_sdio"
 
@@ -67,6 +68,9 @@ eppp_transport_handle_t eppp_sdio_init(struct eppp_config_sdio_s *config)
     ESP_RETURN_ON_FALSE(config, NULL, TAG, "Config cannot be null");
     struct eppp_sdio *h = calloc(1, sizeof(struct eppp_sdio));
     ESP_RETURN_ON_FALSE(h, NULL, TAG, "Failed to allocate eppp_handle");
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+    h->parent.channel_tx = eppp_sdio_transmit_channel;
+#endif
     h->parent.base.post_attach = post_attach;
     h->is_host = config->is_host;
     esp_err_t (*init_fn)(struct eppp_config_sdio_s * eppp_config) = h->is_host ? eppp_sdio_host_init : eppp_sdio_slave_init;

components/eppp_link/eppp_sdio.h

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -8,8 +8,10 @@
 #define MAX_SDIO_PAYLOAD 1500
 #define SDIO_ALIGN(size) (((size) + 3U) & ~(3U))
 #define SDIO_PAYLOAD SDIO_ALIGN(MAX_SDIO_PAYLOAD)
+#define SDIO_PACKET_SIZE SDIO_ALIGN(MAX_SDIO_PAYLOAD + 4)
 #define PPP_SOF 0x7E
 
+
 // Interrupts and registers
 #define SLAVE_INTR      0
 #define SLAVE_REG_REQ   0
@@ -17,3 +19,11 @@
 // Requests from host to slave
 #define REQ_RESET 1
 #define REQ_INIT  2
+
+struct header {
+    uint8_t magic;
+    uint8_t channel;
+    uint16_t size;
+} __attribute__((packed));
+
+esp_err_t eppp_sdio_transmit_channel(esp_netif_t *netif, int channel, void *buffer, size_t len);

components/eppp_link/eppp_sdio_host.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -15,6 +15,7 @@
 #include "sdmmc_cmd.h"
 #include "esp_check.h"
 #include "eppp_link.h"
+#include "eppp_transport.h"
 
 #if CONFIG_EPPP_LINK_DEVICE_SDIO_HOST
 
@@ -28,22 +29,23 @@ static SemaphoreHandle_t s_essl_mutex = NULL;
 static essl_handle_t s_essl = NULL;
 static sdmmc_card_t *s_card = NULL;
 
-static DRAM_DMA_ALIGNED_ATTR uint8_t send_buffer[SDIO_PAYLOAD];
-static DMA_ATTR uint8_t rcv_buffer[SDIO_PAYLOAD];
+static DRAM_DMA_ALIGNED_ATTR uint8_t send_buffer[SDIO_PACKET_SIZE];
+static DMA_ATTR uint8_t rcv_buffer[SDIO_PACKET_SIZE];
 
-esp_err_t eppp_sdio_host_tx(void *h, void *buffer, size_t len)
+static esp_err_t eppp_sdio_host_tx_generic(int channel, void *buffer, size_t len)
 {
     if (s_essl == NULL || s_essl_mutex == NULL) {
         // silently skip the Tx if the SDIO not fully initialized
         return ESP_OK;
     }
 
-    memcpy(send_buffer, buffer, len);
-    size_t send_len = SDIO_ALIGN(len);
-    if (send_len > len) {
-        // pad with SOF's
-        memset(&send_buffer[len], PPP_SOF, send_len - len);
-    }
+
+    struct header *head = (void *)send_buffer;
+    head->magic = PPP_SOF;
+    head->channel = channel;
+    head->size = len;
+    memcpy(send_buffer + sizeof(struct header), buffer, len);
+    size_t send_len = SDIO_ALIGN(len + sizeof(struct header));
     xSemaphoreTake(s_essl_mutex, portMAX_DELAY);
     esp_err_t ret = essl_send_packet(s_essl, send_buffer, send_len, PACKET_TIMEOUT_MS);
     if (ret != ESP_OK) {
@@ -56,6 +58,19 @@ esp_err_t eppp_sdio_host_tx(void *h, void *buffer, size_t len)
     return ret;
 }
 
+esp_err_t eppp_sdio_host_tx(void *h, void *buffer, size_t len)
+{
+    return eppp_sdio_host_tx_generic(0, buffer, len);
+}
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+esp_err_t eppp_sdio_transmit_channel(esp_netif_t *netif, int channel, void *buffer, size_t len)
+{
+    return eppp_sdio_host_tx_generic(channel, buffer, len);
+}
+#endif
+
+
 static esp_err_t request_slave_reset(void)
 {
     esp_err_t ret = ESP_OK;
@@ -145,15 +160,37 @@ esp_err_t eppp_sdio_host_rx(esp_netif_t *netif)
     if (intr & ESSL_SDIO_DEF_ESP32.new_packet_intr_mask) {
         esp_err_t ret;
         do {
-            size_t size_read = SDIO_PAYLOAD;
-            ret = essl_get_packet(s_essl, rcv_buffer, SDIO_PAYLOAD, &size_read, PACKET_TIMEOUT_MS);
+            size_t size_read = SDIO_PACKET_SIZE;
+            ret = essl_get_packet(s_essl, rcv_buffer, SDIO_PACKET_SIZE, &size_read, PACKET_TIMEOUT_MS);
             if (ret == ESP_ERR_NOT_FOUND) {
                 ESP_LOGE(TAG, "interrupt but no data can be read");
                 break;
             } else if (ret == ESP_OK) {
                 ESP_LOGD(TAG, "receive data, size: %d", size_read);
+                struct header *head = (void *)rcv_buffer;
+                if (head->magic != PPP_SOF) {
+                    ESP_LOGE(TAG, "invalid magic %x", head->magic);
+                    break;
+                }
+                if (head->channel > NR_OF_CHANNELS) {
+                    ESP_LOGE(TAG, "invalid channel %x", head->channel);
+                    break;
+                }
+                if (head->size > SDIO_PAYLOAD || head->size > size_read) {
+                    ESP_LOGE(TAG, "invalid size %x", head->size);
+                    break;
+                }
                 ESP_LOG_BUFFER_HEXDUMP(TAG, rcv_buffer, size_read, ESP_LOG_VERBOSE);
-                esp_netif_receive(netif, rcv_buffer, size_read, NULL);
+                if (head->channel == 0) {
+                    esp_netif_receive(netif, rcv_buffer + sizeof(struct header), head->size, NULL);
+                } else {
+#if defined(CONFIG_EPPP_LINK_CHANNELS_SUPPORT)
+                    struct eppp_handle *h = esp_netif_get_io_driver(netif);
+                    if (h->channel_rx) {
+                        h->channel_rx(netif, head->channel, rcv_buffer + sizeof(struct header), head->size);
+                    }
+#endif
+                }
                 break;
             } else {
                 ESP_LOGE(TAG, "rx packet error: %08X", ret);

components/eppp_link/eppp_sdio_slave.c

@@ -10,9 +10,9 @@
 #include "esp_netif.h"
 #include "driver/sdio_slave.h"
 #include "eppp_link.h"
+#include "eppp_transport.h"
 #include "eppp_sdio.h"
 #include "esp_check.h"
-
 #if CONFIG_EPPP_LINK_DEVICE_SDIO_SLAVE
 #define BUFFER_NUM 4
 #define BUFFER_SIZE SDIO_PAYLOAD
@@ -21,19 +21,18 @@ static DMA_ATTR uint8_t sdio_slave_rx_buffer[BUFFER_NUM][BUFFER_SIZE];
 static DMA_ATTR uint8_t sdio_slave_tx_buffer[SDIO_PAYLOAD];
 static int s_slave_request = 0;
 
-esp_err_t eppp_sdio_slave_tx(void *h, void *buffer, size_t len)
+static esp_err_t eppp_sdio_host_tx_generic(int channel, void *buffer, size_t len)
 {
     if (s_slave_request != REQ_INIT) {
         // silently skip the Tx if the SDIO not fully initialized
         return ESP_OK;
     }
-    memcpy(sdio_slave_tx_buffer, buffer, len);
-    size_t send_len = SDIO_ALIGN(len);
-    if (send_len > len) {
-        // pad with SOF's if the size is not 4 bytes aligned
-        memset(&sdio_slave_tx_buffer[len], PPP_SOF, send_len - len);
-    }
-
+    struct header *head = (void *)sdio_slave_tx_buffer;
+    head->magic = PPP_SOF;
+    head->channel = channel;
+    head->size = len;
+    memcpy(sdio_slave_tx_buffer + sizeof(struct header), buffer, len);
+    size_t send_len = SDIO_ALIGN(len + sizeof(struct header));
     ESP_LOG_BUFFER_HEXDUMP(TAG, sdio_slave_tx_buffer, send_len, ESP_LOG_VERBOSE);
     esp_err_t ret = sdio_slave_transmit(sdio_slave_tx_buffer, send_len);
     if (ret != ESP_OK) {
@@ -44,6 +43,18 @@ esp_err_t eppp_sdio_slave_tx(void *h, void *buffer, size_t len)
     return ESP_OK;
 }
 
+esp_err_t eppp_sdio_slave_tx(void *h, void *buffer, size_t len)
+{
+    return eppp_sdio_host_tx_generic(0, buffer, len);
+}
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+esp_err_t eppp_sdio_transmit_channel(esp_netif_t *netif, int channel, void *buffer, size_t len)
+{
+    return eppp_sdio_host_tx_generic(channel, buffer, len);
+}
+#endif
+
 static esp_err_t slave_reset(void)
 {
     esp_err_t ret = ESP_OK;
@@ -82,7 +93,29 @@ esp_err_t eppp_sdio_slave_rx(esp_netif_t *netif)
     if (ret == ESP_ERR_NOT_FINISHED || ret == ESP_OK) {
 again:
         ptr = sdio_slave_recv_get_buf(handle, &length);
-        esp_netif_receive(netif, ptr, length, NULL);
+        struct header *head = (void *)ptr;
+        if (head->magic != PPP_SOF) {
+            ESP_LOGE(TAG, "invalid magic %x", head->magic);
+            return ESP_FAIL;
+        }
+        if (head->channel > NR_OF_CHANNELS) {
+            ESP_LOGE(TAG, "invalid channel %x", head->channel);
+            return ESP_FAIL;
+        }
+        if (head->size > SDIO_PAYLOAD || head->size > length) {
+            ESP_LOGE(TAG, "invalid size %x", head->size);
+            return ESP_FAIL;
+        }
+        if (head->channel == 0) {
+            esp_netif_receive(netif, ptr + sizeof(struct header), head->size, NULL);
+        } else {
+#if defined(CONFIG_EPPP_LINK_CHANNELS_SUPPORT)
+            struct eppp_handle *h = esp_netif_get_io_driver(netif);
+            if (h->channel_rx) {
+                h->channel_rx(netif, head->channel, ptr + sizeof(struct header), head->size);
+            }
+#endif
+        }
         if (sdio_slave_recv_load_buf(handle) != ESP_OK) {
             ESP_LOGE(TAG, "Failed to recycle packet buffer");
             return ESP_FAIL;

components/eppp_link/eppp_spi.c

@@ -6,6 +6,7 @@
 #include <string.h>
 #include <stdint.h>
 #include <inttypes.h>
+#include "sdkconfig.h"
 #include "esp_log.h"
 #include "esp_netif.h"
 #include "esp_check.h"
@@ -24,7 +25,8 @@
 
 #define MAX_PAYLOAD 1500
 #define MIN_TRIGGER_US 20
-#define SPI_HEADER_MAGIC 0x1234
+#define PPP_SOF 0x7E
+#define SPI_HEADER_MAGIC PPP_SOF
 #define SPI_ALIGN(size) (((size) + 3U) & ~(3U))
 #define TRANSFER_SIZE SPI_ALIGN((MAX_PAYLOAD + 6))
 #define NEXT_TRANSACTION_SIZE(a,b) (((a)>(b))?(a):(b)) /* next transaction: whichever is bigger */
@@ -32,10 +34,12 @@
 struct packet {
     size_t len;
     uint8_t *data;
+    int channel;
 };
 
 struct header {
-    uint16_t magic;
+    uint8_t magic;
+    uint8_t channel;
     uint16_t size;
     uint16_t next_size;
     uint16_t check;
@@ -65,12 +69,10 @@ struct eppp_spi {
     esp_timer_handle_t timer;
 };
 
-static esp_err_t transmit(void *h, void *buffer, size_t len)
+static esp_err_t transmit_generic(struct eppp_spi *handle, int channel, void *buffer, size_t len)
 {
-    struct eppp_handle *common = h;
-    struct eppp_spi *handle = __containerof(common, struct eppp_spi, parent);;
-#if CONFIG_EPPP_LINK_DEVICE_SPI
-    struct packet buf = { };
+
+    struct packet buf = { .channel = channel };
     uint8_t *current_buffer = buffer;
     size_t remaining = len;
     do {    // TODO(IDF-9194): Refactor this loop to allocate only once and perform
@@ -100,14 +102,25 @@ static esp_err_t transmit(void *h, void *buffer, size_t len)
         }
         gpio_set_level(handle->gpio_intr, 0);
     }
-
-#elif CONFIG_EPPP_LINK_DEVICE_UART
-    ESP_LOG_BUFFER_HEXDUMP("ppp_uart_send", buffer, len, ESP_LOG_WARN);
-    uart_write_bytes(handle->uart_port, buffer, len);
-#endif // DEVICE UART or SPI
     return ESP_OK;
 }
 
+static esp_err_t transmit(void *h, void *buffer, size_t len)
+{
+    struct eppp_handle *handle = h;
+    struct eppp_spi *spi_handle = __containerof(handle, struct eppp_spi, parent);;
+    return transmit_generic(spi_handle, 0, buffer, len);
+}
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+static esp_err_t transmit_channel(esp_netif_t *netif, int channel, void *buffer, size_t len)
+{
+    struct eppp_handle *handle = esp_netif_get_io_driver(netif);
+    struct eppp_spi *spi_handle = __containerof(handle, struct eppp_spi, parent);;
+    return transmit_generic(spi_handle, channel, buffer, len);
+}
+#endif
+
 static void IRAM_ATTR timer_callback(void *arg)
 {
     struct eppp_spi *h = arg;
@@ -195,7 +208,9 @@ static esp_err_t init_master(struct eppp_config_spi_s *config, struct eppp_spi *
     };
 
     ESP_GOTO_ON_ERROR(gpio_config(&io_conf), err_dev, TAG, "Failed to config interrupt GPIO");
-    ESP_GOTO_ON_ERROR(gpio_install_isr_service(0), err_dev, TAG, "Failed to install GPIO ISR");
+    ret = gpio_install_isr_service(0);
+    ESP_GOTO_ON_FALSE(ret == ESP_OK || ret == ESP_ERR_INVALID_STATE /* In case the GPIO ISR already installed */,
+                      ret, err_dev, TAG, "Failed to install GPIO ISR");
     ESP_GOTO_ON_ERROR(gpio_set_intr_type(config->intr, GPIO_INTR_ANYEDGE), err_dev, TAG, "Failed to set ISR type");
     ESP_GOTO_ON_ERROR(gpio_isr_handler_add(config->intr, gpio_isr_handler, h), err_dev, TAG, "Failed to add ISR handler");
     return ESP_OK;
@@ -339,6 +354,7 @@ esp_err_t eppp_perform(esp_netif_t *netif)
     if (h->outbound.len <= h->transaction_size && allow_test_tx == false) {
         // sending outbound
         head->size = h->outbound.len;
+        head->channel = h->outbound.channel;
         if (h->outbound.len > 0) {
             memcpy(out_buf + sizeof(struct header), h->outbound.data, h->outbound.len);
             free(h->outbound.data);
@@ -355,6 +371,7 @@ esp_err_t eppp_perform(esp_netif_t *netif)
     } else {
         // outbound is bigger, need to transmit in another transaction (keep this empty)
         head->size = 0;
+        head->channel = 0;
     }
     next_tx_size = head->next_size = h->outbound.len;
     head->magic = SPI_HEADER_MAGIC;
@@ -367,17 +384,25 @@ esp_err_t eppp_perform(esp_netif_t *netif)
     }
     head = (void *)in_buf;
     uint16_t check = esp_rom_crc16_le(0, in_buf, sizeof(struct header) - sizeof(uint16_t));
-    if (check != head->check || head->magic != SPI_HEADER_MAGIC) {
+    if (check != head->check || head->magic != SPI_HEADER_MAGIC || head->channel > NR_OF_CHANNELS) {
         h->transaction_size = 0; // need to start with HEADER only transaction
         if (allow_test_tx) {
             return ESP_OK;
         }
-        ESP_LOGE(TAG, "Wrong checksum or magic");
+        ESP_LOGE(TAG, "Wrong checksum, magic, or channel: %x %x %x", check, head->magic, head->channel);
         return ESP_FAIL;
     }
     if (head->size > 0) {
         ESP_LOG_BUFFER_HEXDUMP(TAG, in_buf + sizeof(struct header), head->size, ESP_LOG_VERBOSE);
-        esp_netif_receive(netif, in_buf + sizeof(struct header), head->size, NULL);
+        if (head->channel == 0) {
+            esp_netif_receive(netif, in_buf + sizeof(struct header), head->size, NULL);
+        } else {
+#if defined(CONFIG_EPPP_LINK_CHANNELS_SUPPORT)
+            if (h->parent.channel_rx) {
+                h->parent.channel_rx(netif, head->channel, in_buf + sizeof(struct header), head->size);
+            }
+#endif
+        }
     }
     h->transaction_size = NEXT_TRANSACTION_SIZE(next_tx_size, head->next_size);
     return ESP_OK;
@@ -415,6 +440,9 @@ eppp_transport_handle_t eppp_spi_init(struct eppp_config_spi_s *config)
     ESP_RETURN_ON_FALSE(config, NULL, TAG, "Config cannot be null");
     struct eppp_spi *h = calloc(1, sizeof(struct eppp_spi));
     ESP_RETURN_ON_FALSE(h, NULL, TAG, "Failed to allocate eppp_handle");
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+    h->parent.channel_tx = transmit_channel;
+#endif
     h->is_master = config->is_master;
     h->parent.base.post_attach = post_attach;
     h->out_queue = xQueueCreate(CONFIG_EPPP_LINK_PACKET_QUEUE_SIZE, sizeof(struct packet));
@@ -442,9 +470,6 @@ err:
     if (h->ready_semaphore) {
         vSemaphoreDelete(h->ready_semaphore);
     }
-    if (h->out_queue) {
-        vQueueDelete(h->out_queue);
-    }
     free(h);
     return NULL;
 }

components/eppp_link/eppp_transport.h

@@ -5,6 +5,13 @@
  */
 #pragma once
 #include "esp_netif_types.h"
+#include "sdkconfig.h"
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+#define NR_OF_CHANNELS CONFIG_EPPP_LINK_NR_OF_CHANNELS
+#else
+#define NR_OF_CHANNELS 1
+#endif
 
 struct eppp_handle {
     esp_netif_driver_base_t base;
@@ -12,6 +19,11 @@ struct eppp_handle {
     bool stop;
     bool exited;
     bool netif_stop;
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+    eppp_channel_fn_t channel_tx;
+    eppp_channel_fn_t channel_rx;
+    void* context;
+#endif
 };
 
 esp_err_t eppp_check_connection(esp_netif_t *netif);

components/eppp_link/eppp_uart.c

@@ -31,19 +31,19 @@ struct eppp_uart {
 
 struct header {
     uint8_t magic;
+    uint8_t channel;
     uint8_t check;
     uint16_t size;
 } __attribute__((packed));
 
-static esp_err_t transmit(void *h, void *buffer, size_t len)
+static esp_err_t transmit_generic(struct eppp_uart *handle, int channel, void *buffer, size_t len)
 {
-    struct eppp_handle *common = h;
-    struct eppp_uart *handle = __containerof(common, struct eppp_uart, parent);
 #ifndef CONFIG_EPPP_LINK_USES_PPP
     static uint8_t out_buf[MAX_PACKET_SIZE] = {};
     struct header *head = (void *)out_buf;
     head->magic = HEADER_MAGIC;
     head->check = 0;
+    head->channel = channel;
     head->size = len;
     head->check = (0xFF & len) ^ (len >> 8);
     memcpy(out_buf + sizeof(struct header), buffer, len);
@@ -56,6 +56,22 @@ static esp_err_t transmit(void *h, void *buffer, size_t len)
     return ESP_OK;
 }
 
+static esp_err_t transmit(void *h, void *buffer, size_t len)
+{
+    struct eppp_handle *handle = h;
+    struct eppp_uart *uart_handle = __containerof(handle, struct eppp_uart, parent);
+    return transmit_generic(uart_handle, 0, buffer, len);
+}
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+static esp_err_t transmit_channel(esp_netif_t *netif, int channel, void *buffer, size_t len)
+{
+    struct eppp_handle *handle = esp_netif_get_io_driver(netif);
+    struct eppp_uart *uart_handle = __containerof(handle, struct eppp_uart, parent);
+    return transmit_generic(uart_handle, channel, buffer, len);
+}
+#endif
+
 static esp_err_t init_uart(struct eppp_uart *h, struct eppp_config_uart_s *config)
 {
     h->uart_port = config->port;
@@ -64,12 +80,12 @@ static esp_err_t init_uart(struct eppp_uart *h, struct eppp_config_uart_s *confi
     uart_config.data_bits = UART_DATA_8_BITS;
     uart_config.parity    = UART_PARITY_DISABLE;
     uart_config.stop_bits = UART_STOP_BITS_1;
-    uart_config.flow_ctrl = UART_HW_FLOWCTRL_DISABLE;
+    uart_config.flow_ctrl = config->flow_control;
     uart_config.source_clk = UART_SCLK_DEFAULT;
 
     ESP_RETURN_ON_ERROR(uart_driver_install(h->uart_port, config->rx_buffer_size, 0, config->queue_size, &h->uart_event_queue, 0), TAG, "Failed to install UART");
     ESP_RETURN_ON_ERROR(uart_param_config(h->uart_port, &uart_config), TAG, "Failed to set params");
-    ESP_RETURN_ON_ERROR(uart_set_pin(h->uart_port, config->tx_io, config->rx_io, UART_PIN_NO_CHANGE, UART_PIN_NO_CHANGE), TAG, "Failed to set UART pins");
+    ESP_RETURN_ON_ERROR(uart_set_pin(h->uart_port, config->tx_io, config->rx_io, config->rts_io, config->cts_io), TAG, "Failed to set UART pins");
     ESP_RETURN_ON_ERROR(uart_set_rx_timeout(h->uart_port, 1), TAG, "Failed to set UART Rx timeout");
     return ESP_OK;
 }
@@ -122,6 +138,7 @@ static void process_packet(esp_netif_t *netif, uart_port_t uart_port, size_t ava
 
         // Check if we have the complete packet
         uint16_t payload_size = head->size;
+        int channel = head->channel;
         size_t total_packet_size = sizeof(struct header) + payload_size;
 
         if (payload_size > MAX_PAYLOAD) {
@@ -136,7 +153,17 @@ static void process_packet(esp_netif_t *netif, uart_port_t uart_port, size_t ava
         }
 
         // Got a complete packet, pass it to network
-        esp_netif_receive(netif, in_buf + buf_start + sizeof(struct header), payload_size, NULL);
+        if (channel == 0) {
+            esp_netif_receive(netif, in_buf + buf_start + sizeof(struct header), payload_size, NULL);
+        } else {
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+            struct eppp_handle *handle = esp_netif_get_io_driver(netif);
+            struct eppp_uart *h = __containerof(handle, struct eppp_uart, parent);
+            if (h->parent.channel_rx) {
+                h->parent.channel_rx(netif, channel, in_buf + buf_start + sizeof(struct header), payload_size);
+            }
+#endif
+        }
 
         // Advance start pointer past this packet
         buf_start += total_packet_size;
@@ -237,10 +264,14 @@ eppp_transport_handle_t eppp_uart_init(struct eppp_config_uart_s *config)
     ESP_RETURN_ON_FALSE(config, NULL, TAG, "Config cannot be null");
     struct eppp_uart *h = calloc(1, sizeof(struct eppp_uart));
     ESP_RETURN_ON_FALSE(h, NULL, TAG, "Failed to allocate eppp_handle");
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+    h->parent.channel_tx = transmit_channel;
+#endif
     h->parent.base.post_attach = post_attach;
     ESP_GOTO_ON_ERROR(init_uart(h, config), err, TAG, "Failed to init UART");
     return &h->parent;
 err:
+    free(h);
     return NULL;
 }
 

components/eppp_link/examples/host/main/CMakeLists.txt

@@ -1,2 +1,6 @@
+if(CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL)
+    set(wifi_over_channels channel_wifi_station.c)
+endif()
 idf_component_register(SRCS app_main.c register_iperf.c
-                    INCLUDE_DIRS ".")
+                            ${wifi_over_channels}
+                       INCLUDE_DIRS ".")

components/eppp_link/examples/host/main/Kconfig.projbuild

@@ -106,4 +106,14 @@ menu "Example Configuration"
         help
             Baudrate used by the PPP over UART
 
+    config EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+        bool "Use WiFi over EPPP channel"
+        default n
+        depends on EPPP_LINK_CHANNELS_SUPPORT && ESP_WIFI_REMOTE_ENABLED
+        help
+            Enable this option to use WiFi over EPPP channel.
+            If this option is enabled, the example will only start the Wi-Fi driver,
+            but the Wi-Fi netif will reside on client's end and will channel
+            the Rx and Tx data via EPPP channels.
+
 endmenu

components/eppp_link/examples/host/main/app_main.c

@@ -14,6 +14,7 @@
 #include "esp_netif.h"
 #include "eppp_link.h"
 #include "esp_log.h"
+#include "esp_check.h"
 #include "mqtt_client.h"
 #include "console_ping.h"
 
@@ -88,6 +89,7 @@ static void mqtt_app_start(void)
 }
 #endif // MQTT
 
+void station_over_eppp_channel(void *arg);
 
 void app_main(void)
 {
@@ -156,6 +158,9 @@ void app_main(void)
     // start console REPL
     ESP_ERROR_CHECK(console_cmd_start());
 
+#ifdef CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+    station_over_eppp_channel(eppp_netif);
+#endif
 #if CONFIG_EXAMPLE_MQTT
     mqtt_app_start();
 #endif

components/eppp_link/examples/host/main/channel_wifi_station.c

@@ -0,0 +1,185 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_system.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "eppp_link.h"
+#include "esp_log.h"
+#include "esp_check.h"
+#include "esp_wifi_remote.h"
+
+#define CHAT_CHANNEL 1
+#define WIFI_CHANNEL 2
+
+typedef enum {
+    UNKNOWN,
+    HELLO,
+    START,
+    ERROR,
+} state_t;
+
+typedef struct context {
+    eppp_channel_fn_t transmit;
+    EventGroupHandle_t flags;
+    state_t state;
+    esp_netif_t *eppp;
+} context_t;
+
+#define HELLO_BIT BIT0
+#define START_BIT BIT1
+#define CONNECT_BIT BIT2
+#define SERVER_UP_BIT BIT3
+
+#define ALL_BITS (HELLO_BIT | START_BIT | CONNECT_BIT | SERVER_UP_BIT)
+
+static uint8_t s_wifi_mac_addr[6] = { 0 };
+static const char *TAG = "eppp_host_example_with_channels";
+
+esp_netif_t* esp_wifi_remote_create_default_sta(void);
+
+static void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
+{
+    ESP_LOGI(TAG, "IP event_handler: event_base=%s event_id=%d", event_base, event_id);
+    if (event_base == IP_EVENT && event_id == IP_EVENT_STA_GOT_IP) {
+        ip_event_got_ip_t *event = (ip_event_got_ip_t *) event_data;
+        ESP_LOGI(TAG, "Got IP:" IPSTR, IP2STR(&event->ip_info.ip));
+    }
+}
+
+esp_err_t esp_wifi_remote_get_mac(wifi_interface_t ifx, uint8_t mac[6])
+{
+    if (ifx != WIFI_IF_STA) {
+        return ESP_ERR_INVALID_STATE;
+
+    }
+    for (int i = 0; i < sizeof(s_wifi_mac_addr); i++) {
+        if (s_wifi_mac_addr[i] == 0) {
+            return ESP_ERR_INVALID_STATE;
+        }
+    }
+    memcpy(mac, s_wifi_mac_addr, sizeof(s_wifi_mac_addr));
+    return ESP_OK;
+}
+
+static esp_err_t eppp_receive(esp_netif_t *netif, int nr, void *buffer, size_t len)
+{
+    context_t *ctx = eppp_get_context(netif);
+    if (nr == CHAT_CHANNEL) {
+        ESP_LOGI(TAG, "Received channel=%d len=%d %.*s", nr, (int)len, (int)len, (char *)buffer);
+        const char hello[] = "Hello client";
+        const char mac[] = "MAC: ";
+        const char connected[] = "Connected";
+        const char server_up[] = "Server up";
+        size_t mac_len = 5 /* MAC: */ + 6 * 2 /* 6 bytes per char */ + 5 /* : */ + 1 /* \0 */;
+        if (len == sizeof(server_up) && memcmp(buffer, server_up, len) == 0) {
+            if (ctx->state == UNKNOWN) {
+                ESP_LOGI(TAG, "Server is up");
+                ctx->state = HELLO;
+            } else {
+                ESP_LOGE(TAG, "Received server up in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+            xEventGroupSetBits(ctx->flags, SERVER_UP_BIT);
+        } else if (len == sizeof(hello) && memcmp(buffer, hello, len) == 0) {
+            if (ctx->state == HELLO) {
+                xEventGroupSetBits(ctx->flags, HELLO_BIT);
+            } else {
+                ESP_LOGE(TAG, "Received hello in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+        } else if (len == mac_len && memcmp(buffer, mac, 5) == 0) {
+            if (ctx->state == HELLO) {
+                uint8_t mac_addr[6];
+                sscanf((char *)buffer + 5, "%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8 ":%2" PRIx8,
+                       &mac_addr[0], &mac_addr[1], &mac_addr[2], &mac_addr[3], &mac_addr[4], &mac_addr[5]);
+                ESP_LOGI(TAG, "Parsed MAC: %02x:%02x:%02x:%02x:%02x:%02x\n", mac_addr[0], mac_addr[1], mac_addr[2], mac_addr[3], mac_addr[4], mac_addr[5]);
+                memcpy(s_wifi_mac_addr, mac_addr, sizeof(s_wifi_mac_addr));
+                xEventGroupSetBits(ctx->flags, START_BIT);
+            } else {
+                ESP_LOGE(TAG, "Received MAC in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+        } else if (len == sizeof(connected) && memcmp(buffer, connected, len) == 0) {
+            if (ctx->state == START) {
+                xEventGroupSetBits(ctx->flags, CONNECT_BIT);
+            } else {
+                ESP_LOGE(TAG, "Received connected in unexpected state %d", ctx->state);
+                ctx->state = ERROR;
+            }
+        }
+    } else if (nr == WIFI_CHANNEL) {
+        ESP_LOGD(TAG, "Received WIFI channel=%d len=%d", nr, (int)len);
+        ESP_LOG_BUFFER_HEXDUMP("wifi-receive", buffer, len, ESP_LOG_VERBOSE);
+        return esp_wifi_remote_channel_rx(ctx->eppp, buffer, NULL, len);
+    } else {
+        ESP_LOGE(TAG, "Incorrect channel number %d", nr);
+        return ESP_FAIL;
+    }
+    return ESP_OK;
+}
+
+static esp_err_t wifi_transmit(void *h, void *buffer, size_t len)
+{
+    esp_netif_t *eppp = (esp_netif_t *)h;
+    context_t *ctx = eppp_get_context(eppp);
+    ESP_LOG_BUFFER_HEXDUMP("wifi-transmit", buffer, len, ESP_LOG_VERBOSE);
+    return ctx->transmit(eppp, WIFI_CHANNEL, buffer, len);
+}
+
+void esp_netif_destroy_wifi_remote(void *esp_netif);
+
+void station_over_eppp_channel(void *arg)
+{
+    __attribute__((unused)) esp_err_t ret;
+    esp_netif_t *wifi = NULL;
+    context_t ctx = {
+        .transmit = NULL,
+        .flags = NULL,
+        .state = UNKNOWN,
+        .eppp = (esp_netif_t *)arg
+    };
+    ESP_GOTO_ON_FALSE(ctx.eppp != NULL, ESP_FAIL, err, TAG, "Incorrect EPPP netif");
+    ESP_GOTO_ON_FALSE(ctx.flags = xEventGroupCreate(), ESP_FAIL, err, TAG, "Failed to create event group");
+    ESP_GOTO_ON_ERROR(eppp_add_channels(ctx.eppp, &ctx.transmit, eppp_receive, &ctx), err, TAG, "Failed to add channels");
+    ESP_GOTO_ON_FALSE(ctx.transmit, ESP_FAIL, err, TAG, "Channel tx function is not set");
+    ESP_GOTO_ON_ERROR(esp_wifi_remote_channel_set(WIFI_IF_STA, ctx.eppp, wifi_transmit), err, TAG, "Failed to set wifi channel tx function");
+    esp_event_handler_register(IP_EVENT, IP_EVENT_STA_GOT_IP, event_handler, &ctx);
+
+    while (1) {
+        EventBits_t bits = xEventGroupWaitBits(ctx.flags, ALL_BITS, pdTRUE, pdFALSE, pdMS_TO_TICKS(1000));
+        if (bits & HELLO_BIT) {
+            ESP_LOGI(TAG, "Hello done");
+            if (wifi == NULL) {
+                wifi = esp_wifi_remote_create_default_sta();
+            }
+            const char command[] = "Get MAC";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)command, sizeof(command));
+        } else if (bits & START_BIT) {
+            ctx.state = START;
+            ESP_LOGI(TAG, "Starting WIFI");
+            esp_event_post(WIFI_REMOTE_EVENT, WIFI_EVENT_STA_START, NULL, 0, 0);
+        } else if (bits & CONNECT_BIT) {
+            ESP_LOGI(TAG, "WIFI connected");
+            esp_event_post(WIFI_REMOTE_EVENT, WIFI_EVENT_STA_CONNECTED, NULL, 0, 0);
+        } else if ((bits & SERVER_UP_BIT) == SERVER_UP_BIT || ctx.state != START)  {
+            if (ctx.state == ERROR) {
+                esp_netif_destroy_wifi_remote(wifi);
+                wifi = NULL;
+                ESP_LOGI(TAG, "WiFi netif has been destroyed");
+            }
+            const char hello[] = "Hello server";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)hello, sizeof(hello));
+            ctx.state = HELLO;
+        }
+    }
+
+err:
+    vTaskDelete(NULL);
+}

components/eppp_link/examples/host/main/idf_component.yml

@@ -1,7 +1,7 @@
 dependencies:
-  espressif/iperf-cmd: "^0.1.1"
+  espressif/iperf-cmd: ^0.1.1
   espressif/eppp_link:
-    version: "*"
-    override_path: "../../.."
+    version: '*'
+    override_path: ../../..
   console_cmd_ping:
-    version: "*"
+    version: '*'

components/eppp_link/examples/host/sdkconfig.ci.1

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32s3"
+CONFIG_EPPP_LINK_DEVICE_SPI=y
+CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y
+CONFIG_EPPP_LINK_USES_PPP=y

components/eppp_link/examples/host/sdkconfig.ci.2

@@ -0,0 +1,3 @@
+CONFIG_IDF_TARGET="esp32c3"
+CONFIG_EPPP_LINK_DEVICE_UART=y
+CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y

components/eppp_link/examples/host/sdkconfig.defaults

@@ -1,4 +1 @@
-CONFIG_LWIP_PPP_SUPPORT=y
-CONFIG_LWIP_PPP_SERVER_SUPPORT=y
 CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n
-CONFIG_LWIP_PPP_DEBUG_ON=y

components/eppp_link/examples/slave/main/CMakeLists.txt

@@ -1,2 +1,6 @@
-idf_component_register(SRCS "eppp_slave.c"
-                    INCLUDE_DIRS ".")
+if(CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL)
+    set(wifi_over_channels channel_wifi_station.c)
+endif()
+idf_component_register(SRCS eppp_slave.c
+                            ${wifi_over_channels}
+                       INCLUDE_DIRS ".")

components/eppp_link/examples/slave/main/Kconfig.projbuild

@@ -98,4 +98,14 @@ menu "Example Configuration"
         help
             Baudrate used by the PPP over UART
 
+    config EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+        bool "Use WiFi over EPPP channel"
+        default n
+        depends on EPPP_LINK_CHANNELS_SUPPORT
+        help
+            Enable this option to use WiFi over EPPP channel.
+            If this option is enabled, the example will only start the Wi-Fi driver,
+            but the Wi-Fi netif will reside on client's end and will channel
+            the Rx and Tx data via EPPP channels.
+
 endmenu

components/eppp_link/examples/slave/main/channel_wifi_station.c

@@ -0,0 +1,169 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <stdio.h>
+#include <stdint.h>
+#include <stddef.h>
+#include <string.h>
+#include "esp_system.h"
+#include "esp_event.h"
+#include "esp_netif.h"
+#include "eppp_link.h"
+#include "esp_log.h"
+#include "esp_check.h"
+#include "esp_private/wifi.h"
+
+#define CHAT_CHANNEL 1
+#define WIFI_CHANNEL 2
+
+typedef enum {
+    UNKNOWN,
+    HELLO,
+    START,
+    ERROR,
+} state_t;
+
+typedef struct context {
+    eppp_channel_fn_t transmit;
+    EventGroupHandle_t flags;
+    state_t state;
+    esp_netif_t *eppp;
+} context_t;
+
+#define HELLO_BIT BIT0
+#define START_BIT BIT1
+#define CONNECT_BIT BIT2
+#define DISCONNECT_BIT BIT3
+
+#define ALL_BITS (HELLO_BIT | START_BIT | CONNECT_BIT | DISCONNECT_BIT)
+
+static const char *TAG = "eppp_host_example_with_channels";
+static context_t *s_eppp_channel_ctx = NULL;
+
+static esp_err_t eppp_receive(esp_netif_t *netif, int nr, void *buffer, size_t len)
+{
+    context_t *ctx = eppp_get_context(netif);
+    if (nr == CHAT_CHANNEL) {
+        ESP_LOGI(TAG, "Received channel=%d len=%d %.*s", nr, (int)len, (int)len, (char *)buffer);
+        const char hello[] = "Hello server";
+        const char mac[] = "Get MAC";
+        if (len == sizeof(hello) && memcmp(buffer, hello, len) == 0) {
+            if (ctx->state == HELLO) {
+                xEventGroupSetBits(ctx->flags, HELLO_BIT);
+            } else {
+                ctx->state = ERROR;
+            }
+        } else if (len == sizeof(mac) && memcmp(buffer, mac, 5) == 0) {
+            if (ctx->state == HELLO) {
+                xEventGroupSetBits(ctx->flags, START_BIT);
+            } else {
+                ctx->state = ERROR;
+            }
+        }
+    } else if (nr == WIFI_CHANNEL) {
+        ESP_LOGD(TAG, "Received WIFI channel=%d len=%d", nr, (int)len);
+        ESP_LOG_BUFFER_HEXDUMP("wifi-receive", buffer, len, ESP_LOG_VERBOSE);
+        return esp_wifi_internal_tx(WIFI_IF_STA, buffer, len);
+    } else {
+        ESP_LOGE(TAG, "Incorrect channel number %d", nr);
+        return ESP_FAIL;
+    }
+    return ESP_OK;
+}
+
+static esp_err_t wifi_receive(void *buffer, uint16_t len, void *eb)
+{
+    s_eppp_channel_ctx->transmit(s_eppp_channel_ctx->eppp, WIFI_CHANNEL, buffer, len);
+    esp_wifi_internal_free_rx_buffer(eb);
+    return ESP_OK;
+}
+
+static void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
+{
+    context_t *ctx = arg;
+    ESP_LOGI(TAG, "event_handler: event_base=%s event_id=%d", event_base, event_id);
+    if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        ESP_LOGI(TAG, "WIFI start event");
+        esp_wifi_connect();
+        xEventGroupSetBits(ctx->flags, CONNECT_BIT);
+    } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
+        ESP_LOGI(TAG, "connect to the AP fail");
+        xEventGroupSetBits(ctx->flags, DISCONNECT_BIT);
+    }
+}
+
+
+static void init_wifi_driver(context_t *ctx)
+{
+    wifi_init_config_t cfg = WIFI_INIT_CONFIG_DEFAULT();
+    ESP_ERROR_CHECK(esp_wifi_init(&cfg));
+    ESP_ERROR_CHECK(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID,
+                                               event_handler, ctx));
+    wifi_config_t wifi_config = {
+        .sta = {
+            .ssid = CONFIG_ESP_WIFI_SSID,
+            .password = CONFIG_ESP_WIFI_PASSWORD,
+        },
+    };
+    ESP_ERROR_CHECK(esp_wifi_set_mode(WIFI_MODE_STA));
+    ESP_ERROR_CHECK(esp_wifi_set_config(WIFI_IF_STA, &wifi_config));
+}
+
+void station_over_eppp_channel(void *arg)
+{
+    __attribute__((unused)) esp_err_t ret;
+    context_t ctx = {
+        .transmit = NULL,
+        .flags = NULL,
+        .state = UNKNOWN,
+        .eppp = (esp_netif_t *)arg
+    };
+    ESP_GOTO_ON_FALSE(ctx.flags = xEventGroupCreate(), ESP_FAIL, err, TAG, "Failed to create event group");
+    ESP_GOTO_ON_ERROR(eppp_add_channels(ctx.eppp, &ctx.transmit, eppp_receive, &ctx), err, TAG, "Failed to add channels");
+    ESP_GOTO_ON_FALSE(ctx.transmit, ESP_FAIL, err, TAG, "Channel tx function is not set");
+    init_wifi_driver(&ctx);
+
+    while (1) {
+        EventBits_t bits = xEventGroupWaitBits(ctx.flags, ALL_BITS, pdTRUE, pdFALSE, pdMS_TO_TICKS(1000));
+        if (bits & HELLO_BIT) {
+            ESP_LOGI(TAG, "Hello from client received");
+            const char hello[] = "Hello client";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)hello, sizeof(hello));
+        } else if (bits & START_BIT) {
+            ctx.state = START;
+            ESP_LOGI(TAG, "Starting WIFI");
+            uint8_t mac[6];
+            if (esp_wifi_get_mac(WIFI_IF_STA, mac) != ESP_OK) {
+                ESP_LOGE(TAG, "esp_wifi_get_mac failed");
+                ctx.state = ERROR;
+                continue;
+            }
+            char mac_data[5 /* MAC: */ + 6 * 2 /* 6 bytes per char */ + 5 /* : */ + 1 /* \0 */];
+            sprintf(mac_data, "MAC: %02x:%02x:%02x:%02x:%02x:%02x", mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+            ESP_LOGI(TAG, "Sending MAC: %.*s", (int)sizeof(mac_data), mac_data);
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)mac_data, sizeof(mac_data));
+            ret = esp_wifi_start();
+            ESP_LOGI(TAG, "WIFI start result: %d", ret);
+            s_eppp_channel_ctx = &ctx;
+            esp_wifi_internal_reg_rxcb(WIFI_IF_STA, wifi_receive);
+        } else if (bits & CONNECT_BIT) {
+            ESP_LOGI(TAG, "WIFI connected");
+            const char connected[] = "Connected";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)connected, sizeof(connected));
+        } else if (bits & DISCONNECT_BIT) {
+            const char disconnected[] = "Disconnected";
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)disconnected, sizeof(disconnected));
+        } else if (ctx.state != START) {
+            ctx.state = HELLO;
+            const char up[] = "Server up";
+            esp_wifi_disconnect();
+            esp_wifi_stop();
+            ctx.transmit(ctx.eppp, CHAT_CHANNEL, (void*)up, sizeof(up));
+        }
+    }
+
+err:
+    vTaskDelete(NULL);
+}

components/eppp_link/examples/slave/main/eppp_slave.c

@@ -11,12 +11,14 @@
 #include "esp_wifi.h"
 #include "esp_event.h"
 #include "esp_log.h"
+#include "esp_check.h"
 #include "nvs_flash.h"
 #include "eppp_link.h"
+#include "inttypes.h"
 
 static const char *TAG = "eppp_slave";
 
-#if CONFIG_SOC_WIFI_SUPPORTED
+#if defined(CONFIG_SOC_WIFI_SUPPORTED) && !defined(CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL)
 
 /* FreeRTOS event group to signal when we are connected*/
 static EventGroupHandle_t s_wifi_event_group;
@@ -27,12 +29,13 @@ static EventGroupHandle_t s_wifi_event_group;
 #define WIFI_CONNECTED_BIT BIT0
 #define WIFI_FAIL_BIT      BIT1
 
-
 static int s_retry_num = 0;
 
 static void event_handler(void *arg, esp_event_base_t event_base, int32_t event_id, void *event_data)
 {
+    ESP_LOGI(TAG, "event_handler: event_base=%s event_id=%" PRIi32, event_base, event_id);
     if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_START) {
+        ESP_LOGI(TAG, "WIFI start event");
         esp_wifi_connect();
     } else if (event_base == WIFI_EVENT && event_id == WIFI_EVENT_STA_DISCONNECTED) {
         if (s_retry_num < CONFIG_ESP_MAXIMUM_RETRY) {
@@ -107,12 +110,15 @@ void init_network_interface(void)
 }
 #else
 
+// If the SoC does not have WiFi capabilities, we can initialize a different network interface, this function is a placeholder for that purpose.
+// This function is also a no-op if EXAMPLE_WIFI_OVER_EPPP_CHANNEL==1, since the Wi-Fi network interface will live on the other peer (on the host side).
 void init_network_interface(void)
 {
-    // placeholder to initialize any other network interface if WiFi is not available
 }
 
-#endif // SoC WiFi capable chip
+#endif // SoC WiFi capable chip || WiFi over EPPP channel
+
+void station_over_eppp_channel(void *arg);
 
 void app_main(void)
 {
@@ -153,5 +159,9 @@ void app_main(void)
         ESP_LOGE(TAG, "Failed to setup connection");
         return ;
     }
+#ifdef CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL
+    station_over_eppp_channel(eppp_netif);
+#else
     ESP_ERROR_CHECK(esp_netif_napt_enable(eppp_netif));
+#endif // CONFIG_EXAMPLE_WIFI_OVER_EPPP_CHANNEL
 }

components/eppp_link/examples/slave/sdkconfig.ci.1

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32s2"
+CONFIG_EPPP_LINK_DEVICE_SPI=y
+CONFIG_EPPP_LINK_CHANNELS_SUPPORT=y
+CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n

components/eppp_link/examples/slave/sdkconfig.ci.2

@@ -0,0 +1,4 @@
+CONFIG_IDF_TARGET="esp32c2"
+CONFIG_EPPP_LINK_DEVICE_UART=y
+CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n
+CONFIG_EPPP_LINK_USES_PPP=y

components/eppp_link/examples/slave/sdkconfig.ci.ipv4_only

@@ -0,0 +1 @@
+CONFIG_LWIP_IPV6=n

components/eppp_link/examples/slave/sdkconfig.defaults

@@ -1,6 +1,3 @@
 CONFIG_LWIP_IP_FORWARD=y
 CONFIG_LWIP_IPV4_NAPT=y
 CONFIG_LWIP_TCPIP_TASK_STACK_SIZE=4096
-CONFIG_LWIP_PPP_SUPPORT=y
-CONFIG_LWIP_PPP_SERVER_SUPPORT=y
-CONFIG_LWIP_PPP_VJ_HEADER_COMPRESSION=n

components/eppp_link/idf_component.yml

@@ -1,4 +1,4 @@
-version: 0.3.0
+version: 1.1.3
 url: https://github.com/espressif/esp-protocols/tree/master/components/eppp_link
 description: The component provides a general purpose PPP connectivity, typically used as WiFi-PPP router
 dependencies:

components/eppp_link/include/eppp_link.h

@@ -5,6 +5,10 @@
  */
 #pragma once
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #define EPPP_DEFAULT_SERVER_IP() ESP_IP4TOADDR(192, 168, 11, 1)
 #define EPPP_DEFAULT_CLIENT_IP() ESP_IP4TOADDR(192, 168, 11, 2)
 
@@ -30,6 +34,9 @@
             .rx_io = 26,        \
             .queue_size = 16,   \
             .rx_buffer_size = 1024, \
+            .rts_io = -1,       \
+            .cts_io = -1,       \
+            .flow_control = 0,  \
     },                          \
 
 #define EPPP_DEFAULT_SDIO_CONFIG() \
@@ -110,7 +117,6 @@ typedef enum eppp_transport {
 
 typedef struct eppp_config_t {
     eppp_transport_t transport;
-
     struct eppp_config_spi_s {
         int host;
         bool is_master;
@@ -132,6 +138,9 @@ typedef struct eppp_config_t {
         int rx_io;
         int queue_size;
         int rx_buffer_size;
+        int rts_io;
+        int cts_io;
+        int flow_control;
     } uart;
 
     struct eppp_config_sdio_s {
@@ -203,3 +212,15 @@ void eppp_netif_deinit(esp_netif_t *netif);
  *  - ESP_ERR_TIMEOUT indicates that the operation was requested to stop
  */
 esp_err_t eppp_perform(esp_netif_t *netif);
+
+#ifdef CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+typedef esp_err_t (*eppp_channel_fn_t)(esp_netif_t *netif, int nr, void *buffer, size_t len);
+
+esp_err_t eppp_add_channels(esp_netif_t *netif, eppp_channel_fn_t *tx, const eppp_channel_fn_t rx, void* context);
+
+void* eppp_get_context(esp_netif_t *netif);
+#endif // CONFIG_EPPP_LINK_CHANNELS_SUPPORT
+
+#ifdef __cplusplus
+}
+#endif

components/eppp_link/test/test_app/CMakeLists.txt

@@ -1,7 +1,15 @@
 # The following four lines of boilerplate have to be in your project's CMakeLists
 # in this exact order for cmake to work correctly
 cmake_minimum_required(VERSION 3.16)
-set(EXTRA_COMPONENT_DIRS $ENV{IDF_PATH}/tools/unit-test-app/components)
 
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
+
+if("${IDF_VERSION_MAJOR}.${IDF_VERSION_MINOR}" VERSION_GREATER_EQUAL "6.0")
+    set(test_component_dir $ENV{IDF_PATH}/tools/test_apps/components)
+else()
+    set(test_component_dir $ENV{IDF_PATH}/tools/unit-test-app/components)
+endif()
+
+set(EXTRA_COMPONENT_DIRS ${test_component_dir})
+
 project(test_app)

components/eppp_link/test/test_app/main/CMakeLists.txt

@@ -1,4 +1,10 @@
+if("${IDF_VERSION_MAJOR}.${IDF_VERSION_MINOR}" VERSION_GREATER "5.3")
+    set(driver_deps esp_driver_gpio esp_driver_spi esp_driver_uart esp_driver_sdio)
+else()
+    set(driver_deps driver)
+endif()
+
 idf_component_register(SRCS app_main.c
                     INCLUDE_DIRS "."
                     REQUIRES test_utils
-                    PRIV_REQUIRES unity nvs_flash esp_netif driver esp_event)
+                    PRIV_REQUIRES unity nvs_flash esp_netif esp_event ${driver_deps})

components/esp_dns/esp_dns_doh.c

@@ -177,6 +177,9 @@ esp_err_t esp_dns_http_event_handler(esp_http_client_event_t *evt)
     case HTTP_EVENT_REDIRECT:
         ESP_LOGE(TAG, "HTTP_EVENT_REDIRECT: Not supported(%d)", esp_http_client_get_status_code(evt->client));
         break;
+    default:
+        ESP_LOGD(TAG, "Other HTTP event: %d", evt->event_id);
+        break;
     }
     return ESP_OK;
 }

components/esp_modem/Kconfig

@@ -103,4 +103,14 @@ menu "esp-modem"
             Set this to 'y' if you're making changes to the actual sources of
             the AT command definitions (typically in esp_modem_command_declare.inc)
 
+    config ESP_MODEM_USE_PPP_MODE
+        bool "Use PPP mode"
+        default y
+        select LWIP_PPP_SUPPORT
+        help
+            If enabled, the library can use PPP netif from lwip.
+            This is the default and most common setting.
+            But it's possible to disable it and use only AT commands,
+            in this case it's not required to enable LWIP_PPP_SUPPORT.
+
 endmenu

components/esp_modem/examples/modem_console/main/console_helper.cpp

@@ -63,13 +63,12 @@ void ConsoleCommand::RegisterCommand(const char *command, const char *help, cons
 
     arg_type end = { .end = arg_end(1) };
     arg_table.emplace_back(end);
-    const esp_console_cmd_t command_def = {
-        .command = command,
-        .help = help,
-        .hint = nullptr,
-        .func = command_func_pts[last_command],
-        .argtable = &arg_table[0]
-    };
+    esp_console_cmd_t command_def = { };
+    command_def.command = command;
+    command_def.help = help;
+    command_def.hint = nullptr;
+    command_def.func = command_func_pts[last_command];
+    command_def.argtable = &arg_table[0];
     ESP_ERROR_CHECK(esp_console_cmd_register(&command_def));
     last_command++;
     console_commands.emplace_back(this);

components/esp_modem/examples/modem_console/main/modem_console_main.cpp

@@ -21,6 +21,7 @@
 #include "cxx_include/esp_modem_dte.hpp"
 #include "esp_modem_config.h"
 #include "cxx_include/esp_modem_api.hpp"
+#include "esp_idf_version.h"
 #if defined(CONFIG_EXAMPLE_SERIAL_CONFIG_USB)
 #include "esp_modem_usb_config.h"
 #include "cxx_include/esp_modem_usb_api.hpp"
@@ -29,6 +30,12 @@
 #include "console_helper.hpp"
 #include "my_module_dce.hpp"
 
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(6, 0, 0)
+#define GET_WAKEUP_CAUSE() esp_sleep_get_wakeup_causes()
+#else
+#define GET_WAKEUP_CAUSE() esp_sleep_get_wakeup_cause()
+#endif
+
 #if defined(CONFIG_EXAMPLE_FLOW_CONTROL_NONE)
 #define EXAMPLE_FLOW_CONTROL ESP_MODEM_FLOW_CONTROL_NONE
 #elif defined(CONFIG_EXAMPLE_FLOW_CONTROL_SW)
@@ -208,7 +215,7 @@ extern "C" void app_main(void)
     esp_console_dev_uart_config_t uart_config = ESP_CONSOLE_DEV_UART_CONFIG_DEFAULT();
     ESP_ERROR_CHECK(esp_console_new_repl_uart(&uart_config, &repl_config, &s_repl));
 
-    switch (esp_sleep_get_wakeup_cause()) {
+    switch (GET_WAKEUP_CAUSE()) {
     case ESP_SLEEP_WAKEUP_TIMER:
         if (esp_modem::modem_mode::CMUX_MODE == mode_rtc) {
             ESP_LOGI(TAG, "Deep sleep reset\n");
@@ -428,7 +435,7 @@ extern "C" void app_main(void)
     const ConsoleCommand SetDeepSleep("set_deep_sleep", "Put esp32 to deep sleep", &deep_sleep_args, sizeof(deep_sleep_args), [&](ConsoleCommand * c) {
         int tout = c->get_int_of(&DeepSleepArgs::timeout);
         ESP_LOGI(TAG, "Entering deep sleep for %d sec", tout);
-        ESP_LOGI(TAG, "Wakeup Cause: %d ", esp_sleep_get_wakeup_cause());
+        ESP_LOGI(TAG, "Wakeup Cause: %d ", GET_WAKEUP_CAUSE());
         esp_deep_sleep(tout * 1000000);
         return 0;
     });

components/esp_modem/examples/modem_tcp_client/main/CMakeLists.txt

@@ -1,7 +1,11 @@
+set(module_dir "generic_module")
 if (CONFIG_EXAMPLE_MODEM_DEVICE_BG96)
     set(device_srcs sock_commands_bg96.cpp)
 elseif(CONFIG_EXAMPLE_MODEM_DEVICE_SIM7600)
     set(device_srcs sock_commands_sim7600.cpp)
+elseif(CONFIG_EXAMPLE_MODEM_DEVICE_ESPAT)
+    set(device_srcs sock_commands_espat.cpp)
+    set(module_dir "espat_module")
 endif()
 
 if(CONFIG_ESP_MODEM_ENABLE_DEVELOPMENT_MODE)
@@ -14,4 +18,4 @@ idf_component_register(SRCS "modem_client.cpp"
                             "${command_dir}/sock_dce.cpp"
                             "tcp_transport_at.cpp"
                             "${device_srcs}"
-                       INCLUDE_DIRS "." "${command_dir}")
+                       INCLUDE_DIRS "." "${command_dir}" "${module_dir}")

components/esp_modem/examples/modem_tcp_client/main/Kconfig.projbuild

@@ -18,8 +18,26 @@ menu "Example Configuration"
             bool "SIM7600"
             help
                 SIM7600 is Multi-Band LTE-TDD/LTE-FDD/HSPA+ and GSM/GPRS/EDGE module
+        config EXAMPLE_MODEM_DEVICE_ESPAT
+            bool "ESP-AT"
+            help
+                ESP-AT firmware for ESP32 modules with WiFi connectivity
     endchoice
 
+    if EXAMPLE_MODEM_DEVICE_ESPAT
+        config EXAMPLE_WIFI_SSID
+            string "WiFi SSID"
+            default "myssid"
+            help
+                SSID (network name) to connect to.
+
+        config EXAMPLE_WIFI_PASSWORD
+            string "WiFi Password"
+            default "mypassword"
+            help
+                WiFi password (WPA or WPA2).
+    endif
+
     config EXAMPLE_MODEM_APN
         string "Set MODEM APN"
         default "internet"

components/esp_modem/examples/modem_tcp_client/main/command/sock_dce.hpp

@@ -8,6 +8,7 @@
 #include "cxx_include/esp_modem_api.hpp"
 #include <cxx_include/esp_modem_dce_factory.hpp>
 #include "sock_commands.hpp"
+#include "sock_module.hpp"
 #include <sys/socket.h>
 
 #pragma  once
@@ -97,8 +98,8 @@ private:
     std::shared_ptr<esp_modem::DTE> &dte;
 };
 
-class DCE : public ::esp_modem::GenericModule {
-    using esp_modem::GenericModule::GenericModule;
+class DCE : public Module {
+    using Module::Module;
 public:
 
     /**

components/esp_modem/examples/modem_tcp_client/main/espat_module/sock_module.hpp

@@ -0,0 +1,24 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "esp_modem_config.h"
+#include "cxx_include/esp_modem_api.hpp"
+
+#pragma  once
+
+namespace sock_dce {
+
+class Module: public esp_modem::GenericModule {
+    using esp_modem::GenericModule::GenericModule;
+public:
+
+    esp_modem::command_result sync() override;
+    esp_modem::command_result set_echo(bool on) override;
+    esp_modem::command_result set_pdp_context(esp_modem::PdpContext &pdp) override;
+
+};
+
+}

components/esp_modem/examples/modem_tcp_client/main/generate/sock_dce.hpp

@@ -8,6 +8,7 @@
 #include "cxx_include/esp_modem_api.hpp"
 #include <cxx_include/esp_modem_dce_factory.hpp>
 #include "sock_commands.hpp"
+#include "sock_module.hpp"
 #include <sys/socket.h>
 
 #pragma  once
@@ -97,8 +98,8 @@ private:
     std::shared_ptr<esp_modem::DTE> &dte;
 };
 
-class DCE : public ::esp_modem::GenericModule {
-    using esp_modem::GenericModule::GenericModule;
+class DCE : public Module {
+    using Module::Module;
 public:
 
 //  --- ESP-MODEM command module starts here ---

components/esp_modem/examples/modem_tcp_client/main/generic_module/sock_module.hpp

@@ -0,0 +1,16 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include "esp_modem_config.h"
+#include "cxx_include/esp_modem_api.hpp"
+
+#pragma  once
+
+namespace sock_dce {
+
+using Module = esp_modem::GenericModule;
+
+}

components/esp_modem/examples/modem_tcp_client/main/modem_client.cpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2023-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Unlicense OR CC0-1.0
  */
@@ -23,8 +23,8 @@
 #include "tcp_transport_mbedtls.h"
 #include "tcp_transport_at.h"
 
-#define BROKER_URL "mqtt.eclipseprojects.io"
-#define BROKER_PORT 8883
+#define BROKER_URL "test.mosquitto.org"
+#define BROKER_PORT 1883
 
 
 static const char *TAG = "modem_client";
@@ -114,7 +114,7 @@ extern "C" void app_main(void)
     mqtt_config.broker.address.port = BROKER_PORT;
     mqtt_config.session.message_retransmit_timeout = 10000;
 #ifndef CONFIG_EXAMPLE_CUSTOM_TCP_TRANSPORT
-    mqtt_config.broker.address.uri = "mqtts://127.0.0.1";
+    mqtt_config.broker.address.uri = "mqtt://127.0.0.1";
     dce->start_listening(BROKER_PORT);
 #else
     mqtt_config.broker.address.uri = "mqtt://" BROKER_URL;
@@ -124,14 +124,14 @@ extern "C" void app_main(void)
     mqtt_config.network.transport = ssl;
 #endif
     esp_mqtt_client_handle_t mqtt_client = esp_mqtt_client_init(&mqtt_config);
-    esp_mqtt_client_register_event(mqtt_client, static_cast<esp_mqtt_event_id_t>(ESP_EVENT_ANY_ID), mqtt_event_handler, NULL);
+    esp_mqtt_client_register_event(mqtt_client, static_cast<esp_mqtt_event_id_t>(ESP_EVENT_ANY_ID), mqtt_event_handler, nullptr);
     esp_mqtt_client_start(mqtt_client);
 #ifndef CONFIG_EXAMPLE_CUSTOM_TCP_TRANSPORT
     if (!dce->connect(BROKER_URL, BROKER_PORT)) {
         ESP_LOGE(TAG, "Failed to start DCE");
         return;
     }
-    while (1) {
+    while (true) {
         while (dce->perform_sock()) {
             ESP_LOGV(TAG, "...performing");
         }

components/esp_modem/examples/modem_tcp_client/main/sock_commands_bg96.cpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2022-2023 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2022-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -18,14 +18,14 @@ using namespace esp_modem;
 
 command_result net_open(CommandableIf *t)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     std::string out;
     auto ret = dce_commands::generic_get_string(t, "AT+QISTATE?\r", out, 1000);
     if (ret != command_result::OK) {
         return ret;
     }
     if (out.find("+QISTATE: 0") != std::string::npos) {
-        ESP_LOGV(TAG, "%s", out.data() );
+        ESP_LOGV(TAG, "%s", out.data());
         ESP_LOGD(TAG, "Already there");
         return command_result::FAIL;
     } else if (out.empty()) {
@@ -36,7 +36,7 @@ command_result net_open(CommandableIf *t)
 
 command_result net_close(CommandableIf *t)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     dce_commands::generic_command(t, "AT+QICLOSE=0\r", "OK", "ERROR", 10000);
     esp_modem::Task::Delay(1000);
     return dce_commands::generic_command(t, "AT+QIDEACT=1\r", "OK", "ERROR", 40000);
@@ -44,11 +44,11 @@ command_result net_close(CommandableIf *t)
 
 command_result tcp_open(CommandableIf *t, const std::string &host, int port, int timeout)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     std::string ip_open = R"(AT+QIOPEN=1,0,"TCP",")" + host + "\"," + std::to_string(port) + "\r";
     auto ret = dce_commands::generic_command(t, ip_open, "+QIOPEN: 0,0", "ERROR", timeout);
     if (ret != command_result::OK) {
-        ESP_LOGE(TAG, "%s Failed", __func__ );
+        ESP_LOGE(TAG, "%s Failed", __func__);
         return ret;
     }
     return command_result::OK;
@@ -56,27 +56,27 @@ command_result tcp_open(CommandableIf *t, const std::string &host, int port, int
 
 command_result tcp_close(CommandableIf *t)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     return dce_commands::generic_command(t, "AT+QICLOSE=0\r", "OK", "ERROR", 10000);
 }
 
 command_result tcp_send(CommandableIf *t, uint8_t *data, size_t len)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     assert(0);      // Remove when fix done
     return command_result::FAIL;
 }
 
 command_result tcp_recv(CommandableIf *t, uint8_t *data, size_t len, size_t &out_len)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     assert(0);      // Remove when fix done
     return command_result::FAIL;
 }
 
 command_result get_ip(CommandableIf *t, std::string &ip)
 {
-    ESP_LOGV(TAG, "%s", __func__ );
+    ESP_LOGV(TAG, "%s", __func__);
     std::string out;
     auto ret = dce_commands::generic_get_string(t, "AT+QIACT?\r", out, 5000);
     if (ret != command_result::OK) {
@@ -130,12 +130,15 @@ Responder::ret Responder::recv(uint8_t *data, size_t len)
     auto *recv_data = (char *)data;
     if (data_to_recv == 0) {
         const std::string_view head = "+QIRD: ";
-        auto head_pos = std::search(recv_data, recv_data + len, head.begin(), head.end());
-        if (head_pos == recv_data + len) {
+        const std::string_view recv_data_view = std::string_view(recv_data, len);
+        auto head_pos_found = recv_data_view.find(head);
+        if (head_pos_found == std::string_view::npos) {
             return ret::FAIL;
         }
 
+        auto *head_pos = recv_data + head_pos_found;
         auto next_nl = (char *)memchr(head_pos + head.size(), '\n', MIN_MESSAGE);
+
         if (next_nl == nullptr) {
             return ret::FAIL;
         }

components/esp_modem/examples/modem_tcp_client/main/sock_commands_espat.cpp

@@ -0,0 +1,366 @@
+/*
+ * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#include <charconv>
+#include <cstring>
+#include "sock_commands.hpp"
+#include "cxx_include/esp_modem_command_library_utils.hpp"
+#include "sock_dce.hpp"
+#include "sock_module.hpp"
+
+static const char *TAG = "sock_commands_espat";
+
+namespace sock_dce {
+
+using namespace esp_modem;
+
+command_result Module::sync()
+{
+    return dce_commands::generic_command_common(dte.get(), "AT\r\n");
+}
+
+command_result Module::set_echo(bool on)
+{
+    return dce_commands::generic_command_common(dte.get(), "ATE0\r\n");
+}
+
+command_result Module::set_pdp_context(PdpContext &pdp)
+{
+    return command_result::OK;
+}
+
+}
+
+namespace sock_commands {
+
+using namespace esp_modem;
+
+command_result net_open(CommandableIf *t)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+
+    // Set WiFi mode to station
+    auto ret = dce_commands::generic_command(t, "AT+CWMODE=1\r\n", "OK", "ERROR", 5000);
+    if (ret != command_result::OK) {
+        ESP_LOGE(TAG, "Failed to set WiFi mode");
+        return ret;
+    }
+
+    // Connect to WiFi network
+    std::string wifi_cmd = "AT+CWJAP=\"" CONFIG_EXAMPLE_WIFI_SSID "\",\"" CONFIG_EXAMPLE_WIFI_PASSWORD "\"\r\n";
+    ret = dce_commands::generic_command(t, wifi_cmd, "OK", "ERROR", 15000);
+    if (ret != command_result::OK) {
+        ESP_LOGE(TAG, "Failed to connect to WiFi");
+        return ret;
+    }
+    ESP_LOGI(TAG, "WiFi connected successfully");
+
+    // Set passive receive mode (1) for better control
+    ret = set_rx_mode(t, 1);
+    if (ret != command_result::OK) {
+        ESP_LOGE(TAG, "Failed to set preferred Rx mode");
+        return ret;
+    }
+    return command_result::OK;
+}
+
+command_result net_close(CommandableIf *t)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+    // Disconnect from WiFi
+    auto ret = dce_commands::generic_command(t, "AT+CWQAP\r\n", "OK", "ERROR", 5000);
+    if (ret != command_result::OK) {
+        ESP_LOGW(TAG, "Failed to disconnect WiFi (may already be disconnected)");
+    }
+    return command_result::OK;
+}
+
+command_result tcp_open(CommandableIf *t, const std::string &host, int port, int timeout)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+
+    // Set single connection mode (just in case)
+    auto ret = dce_commands::generic_command(t, "AT+CIPMUX=0\r\n", "OK", "ERROR", 1000);
+    if (ret != command_result::OK) {
+        ESP_LOGW(TAG, "Failed to set single connection mode");
+    }
+
+    // Establish TCP connection
+    std::string tcp_cmd = "AT+CIPSTART=\"TCP\",\"" + host + "\"," + std::to_string(port) + "\r\n";
+    ret = dce_commands::generic_command(t, tcp_cmd, "CONNECT", "ERROR", timeout);
+    if (ret != command_result::OK) {
+        ESP_LOGE(TAG, "Failed to establish TCP connection to %s:%d", host.c_str(), port);
+        return ret;
+    }
+
+    ESP_LOGI(TAG, "TCP connection established to %s:%d", host.c_str(), port);
+    return command_result::OK;
+}
+
+command_result tcp_close(CommandableIf *t)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+    return dce_commands::generic_command(t, "AT+CIPCLOSE\r\n", "CLOSED", "ERROR", 5000);
+}
+
+command_result tcp_send(CommandableIf *t, uint8_t *data, size_t len)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+    // This function is not used in the current implementation
+    // Data sending is handled by the DCE responder
+    return command_result::FAIL;
+}
+
+command_result tcp_recv(CommandableIf *t, uint8_t *data, size_t len, size_t &out_len)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+    // This function is not used in the current implementation
+    // Data receiving is handled by the DCE responder
+    return command_result::FAIL;
+}
+
+command_result get_ip(CommandableIf *t, std::string &ip)
+{
+    ESP_LOGV(TAG, "%s", __func__);
+    std::string out;
+    auto ret = dce_commands::at_raw(t, "AT+CIFSR\r\n", out, "OK", "ERROR", 5000);
+    if (ret != command_result::OK) {
+        return ret;
+    }
+
+    // Parse station IP from response
+    // Expected format: +CIFSR:STAIP,"192.168.1.100"
+    auto pos = out.find("+CIFSR:STAIP,\"");
+    if (pos != std::string::npos) {
+        pos += 14; // Move past "+CIFSR:STAIP,\""
+        auto end_pos = out.find("\"", pos);
+        if (end_pos != std::string::npos) {
+            ip = out.substr(pos, end_pos - pos);
+            ESP_LOGI(TAG, "Got IP address: %s", ip.c_str());
+            return command_result::OK;
+        }
+    }
+
+    ESP_LOGE(TAG, "Failed to parse IP address from response");
+    return command_result::FAIL;
+}
+
+command_result set_rx_mode(CommandableIf *t, int mode)
+{
+    ESP_LOGE(TAG, "%s", __func__);
+    // Active mode (0) sends data automatically, Passive mode (1) notifies about data for reading
+    std::string cmd = "AT+CIPRECVTYPE=" + std::to_string(mode) + "\r\n";
+    return dce_commands::generic_command(t, cmd, "OK", "ERROR", 1000);
+}
+
+} // sock_commands
+
+namespace sock_dce {
+
+void Responder::start_sending(size_t len)
+{
+    data_to_send = len;
+    send_stat = 0;
+    send_cmd("AT+CIPSEND=" + std::to_string(len) + "\r\n");
+}
+
+void Responder::start_receiving(size_t len)
+{
+    send_cmd("AT+CIPRECVDATA=" + std::to_string(len) + "\r\n");
+}
+
+bool Responder::start_connecting(std::string host, int port)
+{
+    std::string cmd = "AT+CIPSTART=\"TCP\",\"" + host + "\"," + std::to_string(port) + "\r\n";
+    send_cmd(cmd);
+    return true;
+}
+
+Responder::ret Responder::recv(uint8_t *data, size_t len)
+{
+    const int MIN_MESSAGE = 6;
+    size_t actual_len = 0;
+    auto *recv_data = (char *)data;
+
+    if (data_to_recv == 0) {
+        const std::string_view head = "+CIPRECVDATA:";
+
+        // Find the response header
+        auto head_pos = std::search(recv_data, recv_data + len, head.data(), head.data() + head.size(), [](char a, char b) {
+            return a == b;
+        });
+
+        if (head_pos == recv_data + len) {
+            return ret::FAIL;
+        }
+
+        // Find the end of the length field
+        auto next_comma = (char *)memchr(head_pos + head.size(), ',', MIN_MESSAGE);
+        if (next_comma == nullptr) {
+            return ret::FAIL;
+        }
+
+        // Parse the actual length
+        if (std::from_chars(head_pos + head.size(), next_comma, actual_len).ec == std::errc::invalid_argument) {
+            ESP_LOGE(TAG, "Cannot convert length");
+            return ret::FAIL;
+        }
+
+        ESP_LOGD(TAG, "Received: actual len=%zu", actual_len);
+        if (actual_len == 0) {
+            ESP_LOGD(TAG, "No data received");
+            return ret::FAIL;
+        }
+
+        if (actual_len > buffer_size) {
+            ESP_LOGE(TAG, "Data too large: %zu > %zu", actual_len, buffer_size);
+            return ret::FAIL;
+        }
+
+        // Move to the actual data after the comma
+        recv_data = next_comma + 1;
+        auto first_data_len = len - (recv_data - (char *)data);
+
+        if (actual_len > first_data_len) {
+            on_read(recv_data, first_data_len);
+            data_to_recv = actual_len - first_data_len;
+            return ret::NEED_MORE_DATA;
+        }
+        on_read(recv_data, actual_len);
+
+    } else if (data_to_recv > len) {    // Continue receiving
+        on_read(recv_data, len);
+        data_to_recv -= len;
+        return ret::NEED_MORE_DATA;
+
+    } else if (data_to_recv <= len) {    // Last chunk
+        on_read(recv_data, data_to_recv);
+        actual_len = data_to_recv;
+    }
+
+    // Look for "OK" marker after the data
+    char *ok_pos = nullptr;
+    if (actual_len + 1 + 2 /* OK */ <= len) {
+        ok_pos = (char *)memchr(recv_data + actual_len + 1, 'O', MIN_MESSAGE);
+        if (ok_pos == nullptr || ok_pos[1] != 'K') {
+            data_to_recv = 0;
+            return ret::FAIL;
+        }
+    }
+
+    // Reset and prepare for next receive
+    data_to_recv = 0;
+    return ret::OK;
+}
+
+Responder::ret Responder::send(uint8_t *data, size_t len)
+{
+    if (send_stat < 3) {
+        // Look for the '>' prompt
+        if (memchr(data, '>', len) == NULL) {
+            if (send_stat++ < 2) {
+                return ret::NEED_MORE_DATA;
+            }
+            ESP_LOGE(TAG, "Missed '>' prompt");
+            return ret::FAIL;
+        }
+
+        // Send the actual data
+        auto written = dte->write(&buffer[0], data_to_send);
+        if (written != data_to_send) {
+            ESP_LOGE(TAG, "Failed to write data: %d/%zu", written, data_to_send);
+            return ret::FAIL;
+        }
+        data_to_send = 0;
+        send_stat = 3;
+    }
+    return ret::IN_PROGRESS;
+}
+
+Responder::ret Responder::send(std::string_view response)
+{
+    if (send_stat == 3) {
+        if (response.find("SEND OK") != std::string::npos) {
+            send_stat = 0;
+            return ret::OK;
+        } else if (response.find("SEND FAIL") != std::string::npos) {
+            ESP_LOGE(TAG, "Send failed");
+            return ret::FAIL;
+        } else if (response.find("ERROR") != std::string::npos) {
+            ESP_LOGE(TAG, "Send error");
+            return ret::FAIL;
+        }
+    }
+    return ret::IN_PROGRESS;
+}
+
+Responder::ret Responder::connect(std::string_view response)
+{
+    if (response.find("CONNECT") != std::string::npos) {
+        ESP_LOGI(TAG, "TCP connected!");
+        return ret::OK;
+    }
+    if (response.find("ERROR") != std::string::npos) {
+        ESP_LOGE(TAG, "Failed to connect");
+        return ret::FAIL;
+    }
+    return ret::IN_PROGRESS;
+}
+
+Responder::ret Responder::check_async_replies(status state, std::string_view &response)
+{
+    ESP_LOGD(TAG, "Response: %.*s", static_cast<int>(response.size()), response.data());
+
+    // Handle WiFi status messages
+    if (response.find("WIFI CONNECTED") != std::string::npos) {
+        ESP_LOGI(TAG, "WiFi connected");
+    } else if (response.find("WIFI DISCONNECTED") != std::string::npos) {
+        ESP_LOGW(TAG, "WiFi disconnected");
+    }
+
+    // Handle TCP status messages
+    if (response.find("CONNECT") != std::string::npos && state == status::CONNECTING) {
+        return connect(response);
+    } else if (response.find("CLOSED") != std::string::npos) {
+        ESP_LOGW(TAG, "TCP connection closed");
+        return ret::FAIL;
+    }
+
+    // Handle data notifications in active mode (if we switch to it later)
+    if (response.find("+IPD,") != std::string::npos) {
+        uint64_t data_ready = 1;
+        write(data_ready_fd, &data_ready, sizeof(data_ready));
+        ESP_LOGD(TAG, "Data available notification");
+    }
+
+    if (state == status::SENDING) {
+        return send(response);
+    } else if (state == status::CONNECTING) {
+        return connect(response);
+    }
+
+    return ret::IN_PROGRESS;
+}
+
+Responder::ret Responder::process_data(status state, uint8_t *data, size_t len)
+{
+    if (state == status::SENDING) {
+        return send(data, len);
+    }
+    if (state == status::RECEIVING) {
+        return recv(data, len);
+    }
+    return ret::IN_PROGRESS;
+}
+
+status Responder::pending()
+{
+    // For ESP-AT, we don't need a pending check like BG96
+    // Just return current status
+    return status::SENDING;
+}
+
+} // sock_dce

components/esp_modem/examples/modem_tcp_client/sdkconfig.ci.espat

@@ -0,0 +1,2 @@
+CONFIG_IDF_TARGET="esp32"
+CONFIG_EXAMPLE_MODEM_DEVICE_ESPAT=y

components/esp_modem/examples/pppos_client/main/Kconfig.projbuild

@@ -185,7 +185,7 @@ menu "Example Configuration"
 
     config EXAMPLE_MQTT_BROKER_URI
         string "MQTT Broker URL"
-        default "mqtt://mqtt.eclipseprojects.io"
+        default "mqtt://test.mosquitto.org"
         help
             URL of the mqtt broker which this example connects to.
 

components/esp_modem/examples/pppos_client/sdkconfig.ci.sim800_c3

@@ -13,5 +13,5 @@ CONFIG_EXAMPLE_MODEM_PPP_APN="lpwa.vodafone.com"
 CONFIG_EXAMPLE_MQTT_TEST_TOPIC="/ci/esp-modem/pppos-client"
 CONFIG_EXAMPLE_PAUSE_NETIF_TO_CHECK_SIGNAL=y
 CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT=y
-CONFIG_ESP32_PANIC_PRINT_HALT=y
 CONFIG_EXAMPLE_DETECT_MODE_BEFORE_CONNECT=y
+CONFIG_EXAMPLE_MQTT_BROKER_URI="mqtt://${CI_MQTT_BROKER_URI}"

components/esp_modem/examples/pppos_client/sdkconfig.ci.usb_a7670_s2

@@ -8,7 +8,6 @@ CONFIG_LWIP_PPP_ENABLE_IPV6=n
 CONFIG_EXAMPLE_SERIAL_CONFIG_USB=y
 CONFIG_EXAMPLE_MODEM_DEVICE_A7670=y
 CONFIG_EXAMPLE_MODEM_PPP_APN="lpwa.vodafone.com"
-CONFIG_EXAMPLE_MODEM_PPP_AUTH_NONE=y
 CONFIG_EXAMPLE_MQTT_TEST_TOPIC="/ci/esp-modem/pppos-client"
 CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT=y
-CONFIG_ESP32_PANIC_PRINT_HALT=y
+CONFIG_EXAMPLE_MQTT_BROKER_URI="mqtt://${CI_MQTT_BROKER_URI}"

components/esp_modem/examples/simple_cmux_client/sdkconfig.ci.sim800_cmux

@@ -11,9 +11,8 @@ CONFIG_EXAMPLE_MODEM_DEVICE_SIM800=y
 CONFIG_EXAMPLE_MODEM_DEVICE_BG96=n
 CONFIG_EXAMPLE_MODEM_PPP_APN="lpwa.vodafone.com"
 CONFIG_ESP_SYSTEM_PANIC_PRINT_HALT=y
-CONFIG_ESP32_PANIC_PRINT_HALT=y
 CONFIG_COMPILER_CXX_EXCEPTIONS=y
 CONFIG_ESP_MAIN_TASK_STACK_SIZE=8192
 CONFIG_EXAMPLE_CLOSE_CMUX_AT_END=y
 CONFIG_EXAMPLE_MQTT_TEST_TOPIC="/ci/esp-modem/pppos-client"
-CONFIG_BROKER_URI="mqtt://mqtt.eclipseprojects.io"
+CONFIG_BROKER_URI="mqtt://${CI_MQTT_BROKER_URI}"

components/esp_modem/include/cxx_include/esp_modem_dce_factory.hpp

@@ -62,12 +62,16 @@ class Creator {
 public:
     Creator(std::shared_ptr<DTE> dte, esp_netif_t *esp_netif): dte(std::move(dte)), device(nullptr), netif(esp_netif)
     {
+#ifdef CONFIG_ESP_MODEM_USE_PPP_MODE
         ESP_MODEM_THROW_IF_FALSE(netif != nullptr, "Null netif");
+#endif
     }
 
     Creator(std::shared_ptr<DTE> dte, esp_netif_t *esp_netif, std::shared_ptr<T_Module> dev): dte(std::move(dte)), device(std::move(dev)), netif(esp_netif)
     {
+#ifdef CONFIG_ESP_MODEM_USE_PPP_MODE
         ESP_MODEM_THROW_IF_FALSE(netif != nullptr, "Null netif");
+#endif
     }
 
     explicit Creator(std::shared_ptr<DTE> dte): dte(std::move(dte)), device(nullptr), netif(nullptr)

components/esp_modem/src/esp_modem_command_library.cpp

@@ -635,17 +635,40 @@ command_result get_network_registration_state(CommandableIf *t, int &state)
     }
 
     constexpr std::string_view pattern = "+CEREG: ";
-    int state_pos_start;
-    int state_pos_end;
-    if (out.find(pattern) == std::string::npos || (state_pos_start = out.find(',')) == std::string::npos) {
+
+    // Check if pattern exists and find its position
+    size_t pattern_pos = out.find(pattern);
+    if (pattern_pos == std::string::npos) {
         return command_result::FAIL;
     }
 
-    if (out.find(pattern) == std::string::npos || (state_pos_end = out.find(',', state_pos_start)) == std::string::npos) {
-        if (std::from_chars(out.data() + state_pos_start, out.data() + out.size(), state).ec == std::errc::invalid_argument) {
-            return command_result::FAIL;
+    // Find the first comma after the pattern
+    size_t state_pos_start = out.find(',', pattern_pos);
+    if (state_pos_start == std::string::npos) {
+        return command_result::FAIL;
+    }
+
+    // Find the end of the state value - either a second comma or end of line
+    size_t state_pos_end = out.find(',', state_pos_start + 1);
+    if (state_pos_end == std::string::npos) {
+        // No second comma found, look for end of line characters
+        state_pos_end = out.find('\r', state_pos_start);
+        if (state_pos_end == std::string::npos) {
+            state_pos_end = out.find('\n', state_pos_start);
         }
-    } else if (std::from_chars(out.data() + state_pos_start, out.data() + state_pos_end, state).ec == std::errc::invalid_argument) {
+        if (state_pos_end == std::string::npos) {
+            // No end delimiter found, use end of string
+            state_pos_end = out.size();
+        }
+    }
+
+    // Validate that we have a valid range to parse
+    if (state_pos_start + 1 >= state_pos_end) {
+        return command_result::FAIL;
+    }
+
+    // Extract state value (skip the comma)
+    if (std::from_chars(out.data() + state_pos_start + 1, out.data() + state_pos_end, state).ec == std::errc::invalid_argument) {
         return command_result::FAIL;
     }
 

components/esp_modem/src/esp_modem_dce.cpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -283,6 +283,10 @@ namespace ppp {
 // Test that we're in the PPP mode by sending an LCP protocol echo request and expecting LCP echo reply
 constexpr std::array<uint8_t, 16> lcp_echo_request = {0x7e, 0xff, 0x03, 0xc0, 0x21, 0x09, 0x01, 0x00, 0x08, 0x99, 0xd1, 0x35, 0xc1, 0x8e, 0x2c, 0x7e };
 constexpr std::array<uint8_t, 5> lcp_echo_reply_head = {0x7e, 0xff, 0x7d, 0x23, 0xc0};
+// PPP frame delimiter
+constexpr uint8_t ppp_delimiter = 0x7e;
+// LCP protocol ID
+constexpr std::array<uint8_t, 2> lcp_protocol_id = {0xc0, 0x21};
 const size_t mode = 1 << 0;
 const int timeout = 200;
 }
@@ -325,27 +329,48 @@ modem_mode DCE_Mode::guess_unsafe(DTE *dte, bool with_cmux)
         ESP_LOG_BUFFER_HEXDUMP("esp-modem: guess mode data:", reply, reply_pos, ESP_LOG_DEBUG);
 
         // Check whether the response resembles the "golden" reply (for these 3 protocols)
-        if (reply_pos >= sizeof(probe::ppp::lcp_echo_reply_head)) {
-            // check for initial 2 bytes
-            auto *ptr = static_cast<uint8_t *>(memmem(reply, reply_pos, probe::ppp::lcp_echo_reply_head.data(), 2));
-            // and check the other two bytes for protocol ID:
-            // * either LCP reply
-            if (ptr && ptr[3] == probe::ppp::lcp_echo_reply_head[3] && ptr[4] == probe::ppp::lcp_echo_reply_head[4]) {
-                if (auto signal = weak_signal.lock()) {
-                    signal->set(probe::ppp::mode);
-                }
-            }
-            // * or LCP conf request
-            if (ptr && ptr[3] == probe::ppp::lcp_echo_request[3] && ptr[4] == probe::ppp::lcp_echo_request[4]) {
-                if (auto signal = weak_signal.lock()) {
-                    signal->set(probe::ppp::mode);
+        if (reply_pos >= 3) { // Minimum size needed for basic PPP detection
+            // Check for PPP detection - look for both traditional format and alternative formats
+
+            // Look for PPP frame delimiter (0x7E)
+            auto *ppp_start = static_cast<uint8_t *>(memchr(reply, probe::ppp::ppp_delimiter, reply_pos));
+            if (ppp_start) {
+                size_t remaining = reply_pos - (ppp_start - reply);
+
+                // Look for LCP protocol ID anywhere within reasonable distance after delimiter
+                if (remaining >= 5) { // Reasonable minimum for finding protocol ID
+                    // Check for original expected pattern
+                    if (memmem(ppp_start, remaining, probe::ppp::lcp_echo_reply_head.data(), 2)) {
+                        // Check for protocol ID in original format position
+                        uint8_t *protocol_pos = ppp_start + 3;
+                        if ((protocol_pos + 1) < (reply + reply_pos) &&
+                                (protocol_pos[0] == probe::ppp::lcp_echo_reply_head[3] &&
+                                 protocol_pos[1] == probe::ppp::lcp_echo_reply_head[4])) {
+                            if (auto signal = weak_signal.lock()) {
+                                signal->set(probe::ppp::mode);
+                                return command_result::OK;
+                            }
+                        }
+                    }
+
+                    // Also check for direct LCP protocol ID after delimiter (alternative format)
+                    if (remaining >= 3 && memmem(ppp_start + 1, remaining - 1,
+                                                 probe::ppp::lcp_protocol_id.data(),
+                                                 probe::ppp::lcp_protocol_id.size())) {
+                        if (auto signal = weak_signal.lock()) {
+                            signal->set(probe::ppp::mode);
+                            return command_result::OK;
+                        }
+                    }
                 }
             }
         }
+
         if (reply_pos >= 4 && memmem(reply, reply_pos, probe::cmd::reply, sizeof(probe::cmd::reply))) {
             if (reply[0] != 0xf9) {   // double check that the reply is not wrapped in CMUX headers
                 if (auto signal = weak_signal.lock()) {
                     signal->set(probe::cmd::mode);
+                    return command_result::OK;
                 }
             }
         }
@@ -356,6 +381,7 @@ modem_mode DCE_Mode::guess_unsafe(DTE *dte, bool with_cmux)
             if (ptr && (ptr[3] >> 2) == 0) {
                 if (auto signal = weak_signal.lock()) {
                     signal->set(probe::cmux::mode);
+                    return command_result::OK;
                 }
             }
         }

components/esp_modem/src/esp_modem_dte.cpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -359,7 +359,6 @@ void DTE::on_read(got_line_cb on_read_cb)
         auto res = on_read_cb(data, len);
         if (res == command_result::OK || res == command_result::FAIL) {
             primary_term->set_read_cb(nullptr);
-            internal_lock.unlock();
             return true;
         }
         return false;
@@ -368,12 +367,14 @@ void DTE::on_read(got_line_cb on_read_cb)
 
 bool DTE::command_cb::process_line(uint8_t *data, size_t consumed, size_t len)
 {
+    // returning true indicates that the processing finished and lower layers can destroy the accumulated buffer
 #ifdef CONFIG_ESP_MODEM_URC_HANDLER
+    bool consume_buffer = false;
     if (urc_handler) {
-        urc_handler(data, consumed + len);
+        consume_buffer = urc_handler(data, consumed + len) != command_result::TIMEOUT;
     }
     if (result != command_result::TIMEOUT || got_line == nullptr) {
-        return false;   // this line has been processed already (got OK or FAIL previously)
+        return consume_buffer;   // this line has been processed already (got OK or FAIL previously)
     }
 #endif
     if (memchr(data + consumed, separator, len)) {

components/esp_modem/src/esp_modem_netif.cpp

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2021-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2021-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -14,7 +14,6 @@
 #include "cxx_include/esp_modem_dte.hpp"
 #include "esp_netif_ppp.h"
 
-
 namespace esp_modem {
 
 void Netif::on_ppp_changed(void *arg, esp_event_base_t event_base,
@@ -39,6 +38,7 @@ esp_err_t Netif::esp_modem_dte_transmit(void *h, void *buffer, size_t len)
     return ESP_FAIL;
 }
 
+#ifdef CONFIG_ESP_MODEM_USE_PPP_MODE
 esp_err_t Netif::esp_modem_post_attach(esp_netif_t *esp_netif, void *args)
 {
     auto d = (ppp_netif_driver *) args;
@@ -62,6 +62,7 @@ esp_err_t Netif::esp_modem_post_attach(esp_netif_t *esp_netif, void *args)
 
     return ESP_OK;
 }
+#endif // CONFIG_ESP_MODEM_USE_PPP_MODE
 
 void Netif::receive(uint8_t *data, size_t len)
 {
@@ -73,12 +74,16 @@ Netif::Netif(std::shared_ptr<DTE> e, esp_netif_t *ppp_netif) :
 {
     driver.base.netif = ppp_netif;
     driver.ppp = this;
+#ifdef CONFIG_ESP_MODEM_USE_PPP_MODE
     driver.base.post_attach = esp_modem_post_attach;
     ESP_MODEM_THROW_IF_ERROR(esp_event_handler_register(NETIF_PPP_STATUS, ESP_EVENT_ANY_ID, &on_ppp_changed, (void *) this));
+#endif
     ESP_MODEM_THROW_IF_ERROR(esp_event_handler_register(IP_EVENT, IP_EVENT_PPP_GOT_IP, esp_netif_action_connected, ppp_netif));
     ESP_MODEM_THROW_IF_ERROR(
         esp_event_handler_register(IP_EVENT, IP_EVENT_PPP_LOST_IP, esp_netif_action_disconnected, ppp_netif));
+#ifdef CONFIG_ESP_MODEM_USE_PPP_MODE
     ESP_MODEM_THROW_IF_ERROR(esp_netif_attach(ppp_netif, &driver));
+#endif
 }
 
 void Netif::start()
@@ -120,7 +125,9 @@ Netif::~Netif()
         signal.clear(PPP_STARTED);
         signal.wait(PPP_EXIT, 30000);
     }
+#ifdef CONFIG_ESP_MODEM_USE_PPP_MODE
     esp_event_handler_unregister(NETIF_PPP_STATUS, ESP_EVENT_ANY_ID, &on_ppp_changed);
+#endif
     esp_event_handler_unregister(IP_EVENT, IP_EVENT_PPP_GOT_IP, esp_netif_action_connected);
     esp_event_handler_unregister(IP_EVENT, IP_EVENT_PPP_LOST_IP, esp_netif_action_disconnected);
 }

components/esp_modem/test/target_ota/main/ota_test.cpp

@@ -14,11 +14,17 @@
 #include "cxx_include/esp_modem_dte.hpp"
 #include "esp_modem_config.h"
 #include "cxx_include/esp_modem_api.hpp"
-#include "esp_vfs_dev.h"        // For optional VFS support
-#include "vfs_resource/vfs_create.hpp"
+#include "esp_idf_version.h"
 #include "network_dce.hpp"
 #include "manual_ota.hpp"
 #include "mqtt_client.h"
+// For optional VFS support
+#include "vfs_resource/vfs_create.hpp"
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 3, 0)
+#include "driver/uart_vfs.h"
+#else
+#include "esp_vfs_dev.h"
+#endif
 
 using namespace esp_modem;
 
@@ -189,7 +195,12 @@ extern "C" void app_main(void)
     assert(vfs_create_uart(&uart_config, &dte_config.vfs_config) == true);
 
     auto dte = create_vfs_dte(&dte_config);
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 3, 0)
+    uart_vfs_dev_use_driver(uart_config.uart.port_num);
+#else
     esp_vfs_dev_uart_use_driver(uart_config.uart.port_num);
+#endif
+
 #else
     auto dte = create_uart_dte(&dte_config);
 #endif // CONFIG_TEST_USE_VFS_TERM

components/esp_modem/test/target_urc/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(COMPONENTS main)
+project(urc_test)

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

@@ -0,0 +1,2 @@
+idf_component_register(SRCS "urc_test.cpp"
+                       INCLUDE_DIRS ".")

components/esp_modem/test/target_urc/main/idf_component.yml

@@ -0,0 +1,7 @@
+## IDF Component Manager Manifest File
+dependencies:
+  ## Required IDF version
+  idf: ">=4.1.0"
+  espressif/esp_modem:
+    version: "^1.0.0"
+    override_path: "../../../"

components/esp_modem/test/target_urc/main/urc_test.cpp

@@ -0,0 +1,158 @@
+/*
+ * SPDX-FileCopyrightText: 2025 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Unlicense OR CC0-1.0
+ */
+#include <cstring>
+#include "freertos/FreeRTOS.h"
+#include "freertos/event_groups.h"
+#include "esp_netif.h"
+#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 "cxx_include/esp_modem_command_library_utils.hpp"
+#include "esp_log.h"
+#include "sdkconfig.h"
+
+static const char *TAG = "urc_test";
+static EventGroupHandle_t s_event_group = nullptr;
+
+class ESP_AT_Module: public ::esp_modem::ModuleIf {
+public:
+    explicit ESP_AT_Module(std::shared_ptr<::esp_modem::DTE> dte, const esp_modem_dce_config *config):
+        dte(std::move(dte)) {}
+
+    bool setup_data_mode() override
+    {
+        // not using network here
+        return true;
+    }
+
+    bool set_mode(::esp_modem::modem_mode mode) override
+    {
+        // we never allow mode change
+        return false;
+    }
+
+protected:
+    std::shared_ptr<::esp_modem::DTE> dte;
+};
+
+class DCE : public esp_modem::DCE_T<ESP_AT_Module> {
+    using DCE_T<ESP_AT_Module>::DCE_T;
+public:
+
+
+    bool init()
+    {
+        for (int i = 0; i < 5; ++i) {
+            if (sync() == esp_modem::command_result::OK) {
+                ESP_LOGI(TAG, "Modem in sync");
+                return true;
+            }
+            vTaskDelay(pdMS_TO_TICKS(500 * (i + 1)));
+        }
+        ESP_LOGE(TAG, "Failed to sync with esp-at");
+        return false;
+    }
+
+    esp_modem::command_result sync()
+    {
+        auto ret = esp_modem::dce_commands::generic_command_common(dte.get(), "AT\r\n");
+        ESP_LOGI(TAG, "Syncing with esp-at...(%d)", static_cast<int>(ret));
+        return ret;
+    }
+
+    bool http_get(const std::string &url)
+    {
+        std::string command = "AT+HTTPCGET=\"" + url + "\"\r\n";
+        set_urc(handle_urc);
+        auto ret = dte->write(esp_modem::DTE_Command(command));
+        ESP_LOGI(TAG, "HTTP GET...(%d)", static_cast<int>(ret));
+        return ret > 0;
+    }
+
+    bool start_http_server() const
+    {
+        auto ret = esp_modem::dce_commands::generic_command_common(dte.get(), "AT+HTTPD\r\n");
+        ESP_LOGI(TAG, "Start HTTP server...(%d)", static_cast<int>(ret));
+        return ret == esp_modem::command_result::OK;
+    }
+
+    static constexpr int transfer_completed = 1;
+private:
+    static esp_modem::command_result handle_urc(uint8_t *data, size_t len)
+    {
+        static int start_chunk = 0;
+        static int end_chunk = 0;
+        std::string_view chunk((const char*)data + start_chunk, len - start_chunk);
+        int newline = chunk.find('\n');
+        if (newline == std::string_view::npos) {
+            end_chunk = len;    // careful, this grows buffer usage
+            printf(".");
+            return esp_modem::command_result::TIMEOUT;
+        }
+        printf("%.*s\n", newline, (char*)data + start_chunk);
+        start_chunk = end_chunk;
+        // check for the last one
+        constexpr char last_chunk[] = "Transfer completed";
+        if (memmem(data, len, last_chunk, sizeof(last_chunk) - 1) != nullptr) {
+            xEventGroupSetBits(s_event_group, transfer_completed);
+        }
+        return esp_modem::command_result::OK;
+    }
+};
+
+class Factory: public ::esp_modem::dce_factory::Factory {
+public:
+    static std::unique_ptr<DCE> create(const esp_modem::dce_config *config, std::shared_ptr<esp_modem::DTE> dte, esp_netif_t *netif)
+    {
+        return build_generic_DCE<ESP_AT_Module, DCE, std::unique_ptr<DCE>>(config, std::move(dte), netif);
+    }
+};
+
+std::unique_ptr<DCE> create(std::shared_ptr<esp_modem::DTE> dte)
+{
+    esp_netif_config_t netif_ppp_config = ESP_NETIF_DEFAULT_PPP();
+    static esp_netif_t *netif = esp_netif_new(&netif_ppp_config);
+    assert(netif);
+
+    esp_modem_dce_config_t dce_config = ESP_MODEM_DCE_DEFAULT_CONFIG("APN"); // dummy config (not used with esp-at)
+    return Factory::create(&dce_config, std::move(dte), netif);
+}
+
+extern "C" void app_main(void)
+{
+    /* Init and register system/core components */
+    ESP_ERROR_CHECK(esp_netif_init());
+    ESP_ERROR_CHECK(esp_event_loop_create_default());
+    s_event_group = xEventGroupCreate();
+
+    esp_modem_dte_config_t dte_config = ESP_MODEM_DTE_DEFAULT_CONFIG();
+    dte_config.dte_buffer_size = 1024;
+    dte_config.uart_config.tx_io_num = 18;
+    dte_config.uart_config.rx_io_num = 17;
+    auto uart_dte = esp_modem::create_uart_dte(&dte_config);
+    if (uart_dte == nullptr) {
+        ESP_LOGE(TAG, "Failed to create UART DTE");
+        return;
+    }
+    auto dce = create(std::move(uart_dte));
+    if (!dce->init()) {
+        ESP_LOGE(TAG,  "Failed to setup network");
+        return;
+    }
+
+    dce->start_http_server();
+
+    dce->http_get("http://127.0.0.1:8080/async");
+
+    EventBits_t bits = xEventGroupWaitBits(s_event_group, 1, pdTRUE, pdFALSE, pdMS_TO_TICKS(15000));
+    if (bits & DCE::transfer_completed) {
+        ESP_LOGI(TAG, "Request finished!");
+    }
+    dce->sync();
+    vEventGroupDelete(s_event_group);
+    ESP_LOGI(TAG, "Done");
+}

components/esp_modem/test/target_urc/sdkconfig.defaults

@@ -0,0 +1,3 @@
+CONFIG_COMPILER_CXX_EXCEPTIONS=y
+CONFIG_LWIP_PPP_SUPPORT=y
+CONFIG_ESP_MODEM_URC_HANDLER=y

components/esp_websocket_client/.cz.yaml

@@ -3,6 +3,6 @@ commitizen:
   bump_message: 'bump(websocket): $current_version -> $new_version'
   pre_bump_hooks: python ../../ci/changelog.py esp_websocket_client
   tag_format: websocket-v$version
-  version: 1.4.0
+  version: 1.5.0
   version_files:
   - idf_component.yml

components/esp_websocket_client/CHANGELOG.md

@@ -1,5 +1,17 @@
 # Changelog
 
+## [1.5.0](https://github.com/espressif/esp-protocols/commits/websocket-v1.5.0)
+
+### Features
+
+- add separate tx lock for send and receive ([250eebf](https://github.com/espressif/esp-protocols/commit/250eebf))
+- add unregister event to websocket client ([ce16050](https://github.com/espressif/esp-protocols/commit/ce16050))
+- add ability to reconnect after close ([19891d8](https://github.com/espressif/esp-protocols/commit/19891d8))
+
+### Bug Fixes
+
+- release client-lock during WEBSOCKET_EVENT_DATA ([030cb75](https://github.com/espressif/esp-protocols/commit/030cb75))
+
 ## [1.4.0](https://github.com/espressif/esp-protocols/commits/websocket-v1.4.0)
 
 ### Features

components/esp_websocket_client/Kconfig

@@ -7,4 +7,17 @@ menu "ESP WebSocket client"
             Enable this option will reallocated buffer when send or receive data and free them when end of use.
             This can save about 2 KB memory when no websocket data send and receive.
 
+    config ESP_WS_CLIENT_SEPARATE_TX_LOCK
+        bool "Enable separate tx lock for send and receive data"
+        default n
+        help
+            Enable this option will use separate lock for send and receive data.
+            This can avoid the lock contention when send and receive data at the same time.
+
+    config ESP_WS_CLIENT_TX_LOCK_TIMEOUT_MS
+        int "TX lock timeout in milliseconds"
+        depends on ESP_WS_CLIENT_SEPARATE_TX_LOCK
+        default 2000
+        help
+            Timeout for acquiring the TX lock when using separate TX lock.
 endmenu

components/esp_websocket_client/esp_websocket_client.c

@@ -1,5 +1,5 @@
 /*
- * SPDX-FileCopyrightText: 2015-2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2015-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
@@ -39,6 +39,10 @@ static const char *TAG = "websocket_client";
 #define WEBSOCKET_KEEP_ALIVE_INTERVAL   (5)
 #define WEBSOCKET_KEEP_ALIVE_COUNT      (3)
 
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+#define WEBSOCKET_TX_LOCK_TIMEOUT_MS    (CONFIG_ESP_WS_CLIENT_TX_LOCK_TIMEOUT_MS)
+#endif
+
 #define ESP_WS_CLIENT_MEM_CHECK(TAG, a, action) if (!(a)) {                                         \
         ESP_LOGE(TAG,"%s(%d): %s", __FUNCTION__, __LINE__, "Memory exhausted");                     \
         action;                                                                                     \
@@ -60,10 +64,17 @@ static const char *TAG = "websocket_client";
 #define WS_OVER_TCP_SCHEME  "ws"
 #define WS_OVER_TLS_SCHEME  "wss"
 #define WS_HTTP_BASIC_AUTH  "Basic "
+#define WS_HTTP_REDIRECT(code) ((code >= 300) && (code < 400))
+
+#if ESP_IDF_VERSION >= ESP_IDF_VERSION_VAL(5, 5, 0)
+// Features supported in 5.5.0
+#define WS_TRANSPORT_REDIRECT_HEADER_SUPPORT    1
+#endif
 
 const static int STOPPED_BIT = BIT0;
 const static int CLOSE_FRAME_SENT_BIT = BIT1;   // Indicates that a close frame was sent by the client
 // and we are waiting for the server to continue with clean close
+const static int REQUESTED_STOP_BIT = BIT2;     // Indicates that a client stop has been requested
 
 ESP_EVENT_DEFINE_BASE(WEBSOCKET_EVENTS);
 
@@ -80,6 +91,7 @@ typedef struct {
     char                        *auth;
     int                         port;
     bool                        auto_reconnect;
+    bool                        close_reconnect;
     void                        *user_context;
     int                         network_timeout_ms;
     char                        *subprotocol;
@@ -130,6 +142,9 @@ struct esp_websocket_client {
     bool                        selected_for_destroying;
     EventGroupHandle_t          status_bits;
     SemaphoreHandle_t           lock;
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+    SemaphoreHandle_t           tx_lock;
+#endif
     size_t                      errormsg_size;
     char                        *errormsg_buffer;
     char                        *rx_buffer;
@@ -376,6 +391,7 @@ static esp_err_t esp_websocket_client_set_config(esp_websocket_client_handle_t c
     if (config->disable_auto_reconnect) {
         cfg->auto_reconnect = false;
     }
+    cfg->close_reconnect = config->enable_close_reconnect;
 
     if (config->disable_pingpong_discon) {
         cfg->pingpong_timeout_sec = 0;
@@ -439,6 +455,9 @@ static void destroy_and_free_resources(esp_websocket_client_handle_t client)
         esp_transport_list_destroy(client->transport_list);
     }
     vSemaphoreDelete(client->lock);
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+    vSemaphoreDelete(client->tx_lock);
+#endif
     free(client->tx_buffer);
     free(client->rx_buffer);
     free(client->errormsg_buffer);
@@ -459,6 +478,7 @@ static esp_err_t stop_wait_task(esp_websocket_client_handle_t client)
     }
 
     client->run = false;
+    xEventGroupSetBits(client->status_bits, REQUESTED_STOP_BIT);
     xEventGroupWaitBits(client->status_bits, STOPPED_BIT, false, true, portMAX_DELAY);
     client->state = WEBSOCKET_STATE_UNKNOW;
     return ESP_OK;
@@ -608,10 +628,17 @@ static int esp_websocket_client_send_with_exact_opcode(esp_websocket_client_hand
         return -1;
     }
 
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+    if (xSemaphoreTakeRecursive(client->tx_lock, timeout) != pdPASS) {
+        ESP_LOGE(TAG, "Could not lock ws-client within %" PRIu32 " timeout", timeout);
+        return -1;
+    }
+#else
     if (xSemaphoreTakeRecursive(client->lock, timeout) != pdPASS) {
         ESP_LOGE(TAG, "Could not lock ws-client within %" PRIu32 " timeout", timeout);
         return -1;
     }
+#endif
 
     if (esp_websocket_new_buf(client, true) != ESP_OK) {
         ESP_LOGE(TAG, "Failed to setup tx buffer");
@@ -651,7 +678,11 @@ static int esp_websocket_client_send_with_exact_opcode(esp_websocket_client_hand
     ret = widx;
 
 unlock_and_return:
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+    xSemaphoreGiveRecursive(client->tx_lock);
+#else
     xSemaphoreGiveRecursive(client->lock);
+#endif
     return ret;
 }
 
@@ -687,6 +718,11 @@ esp_websocket_client_handle_t esp_websocket_client_init(const esp_websocket_clie
     client->lock = xSemaphoreCreateRecursiveMutex();
     ESP_WS_CLIENT_MEM_CHECK(TAG, client->lock, goto _websocket_init_fail);
 
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+    client->tx_lock = xSemaphoreCreateRecursiveMutex();
+    ESP_WS_CLIENT_MEM_CHECK(TAG, client->tx_lock, goto _websocket_init_fail);
+#endif
+
     client->config = calloc(1, sizeof(websocket_config_storage_t));
     ESP_WS_CLIENT_MEM_CHECK(TAG, client->config, goto _websocket_init_fail);
 
@@ -965,8 +1001,17 @@ static esp_err_t esp_websocket_client_recv(esp_websocket_client_handle_t client)
     if (client->last_opcode == WS_TRANSPORT_OPCODES_PING) {
         const char *data = (client->payload_len == 0) ? NULL : client->rx_buffer;
         ESP_LOGD(TAG, "Sending PONG with payload len=%d", client->payload_len);
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+        if (xSemaphoreTakeRecursive(client->tx_lock, WEBSOCKET_TX_LOCK_TIMEOUT_MS) != pdPASS) {
+            ESP_LOGE(TAG, "Could not lock ws-client within %d timeout", WEBSOCKET_TX_LOCK_TIMEOUT_MS);
+            return ESP_FAIL;
+        }
+#endif
         esp_transport_ws_send_raw(client->transport, WS_TRANSPORT_OPCODES_PONG | WS_TRANSPORT_OPCODES_FIN, data, client->payload_len,
                                   client->config->network_timeout_ms);
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+        xSemaphoreGiveRecursive(client->tx_lock);
+#endif
     } else if (client->last_opcode == WS_TRANSPORT_OPCODES_PONG) {
         client->wait_for_pong_resp = false;
     } else if (client->last_opcode == WS_TRANSPORT_OPCODES_CLOSE) {
@@ -1035,6 +1080,29 @@ static void esp_websocket_client_task(void *pv)
                 esp_websocket_client_abort_connection(client, WEBSOCKET_ERROR_TYPE_TCP_TRANSPORT);
                 break;
             }
+#if WS_TRANSPORT_REDIRECT_HEADER_SUPPORT
+            else if (WS_HTTP_REDIRECT(result)) {
+                const char *redir = esp_transport_ws_get_redir_uri(client->transport);
+                if (redir) {
+                    // Redirecting to a new URI
+                    free(client->config->uri);
+
+                    client->config->uri = strdup(redir);
+                    client->config->port = 0;
+
+                    esp_websocket_client_set_uri(client, client->config->uri);
+
+                    if (client->config->port == 0) {
+                        client->config->port = esp_transport_get_default_port(client->transport);
+                    }
+
+                    // Rerun the connection with the redir uri.
+                    client->state = WEBSOCKET_STATE_INIT;
+                    ESP_LOGI(TAG, "Redirecting to %s", client->config->uri);
+                    break;
+                }
+            }
+#endif
             ESP_LOGD(TAG, "Transport connected to %s://%s:%d", client->config->scheme, client->config->host, client->config->port);
 
             client->state = WEBSOCKET_STATE_CONNECTED;
@@ -1048,8 +1116,16 @@ static void esp_websocket_client_task(void *pv)
                 if (_tick_get_ms() - client->ping_tick_ms > client->config->ping_interval_sec * 1000) {
                     client->ping_tick_ms = _tick_get_ms();
                     ESP_LOGD(TAG, "Sending PING...");
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+                    if (xSemaphoreTakeRecursive(client->tx_lock, WEBSOCKET_TX_LOCK_TIMEOUT_MS) != pdPASS) {
+                        ESP_LOGE(TAG, "Could not lock ws-client within %d timeout", WEBSOCKET_TX_LOCK_TIMEOUT_MS);
+                        break;
+                    }
+#endif
                     esp_transport_ws_send_raw(client->transport, WS_TRANSPORT_OPCODES_PING | WS_TRANSPORT_OPCODES_FIN, NULL, 0, client->config->network_timeout_ms);
-
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+                    xSemaphoreGiveRecursive(client->tx_lock);
+#endif
                     if (!client->wait_for_pong_resp && client->config->pingpong_timeout_sec) {
                         client->pingpong_tick_ms = _tick_get_ms();
                         client->wait_for_pong_resp = true;
@@ -1084,7 +1160,16 @@ static void esp_websocket_client_task(void *pv)
             // if closing not initiated by the client echo the close message back
             if ((CLOSE_FRAME_SENT_BIT & xEventGroupGetBits(client->status_bits)) == 0) {
                 ESP_LOGD(TAG, "Closing initiated by the server, sending close frame");
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+                if (xSemaphoreTakeRecursive(client->tx_lock, WEBSOCKET_TX_LOCK_TIMEOUT_MS) != pdPASS) {
+                    ESP_LOGE(TAG, "Could not lock ws-client within %d timeout", WEBSOCKET_TX_LOCK_TIMEOUT_MS);
+                    break;
+                }
+#endif
                 esp_transport_ws_send_raw(client->transport, WS_TRANSPORT_OPCODES_CLOSE | WS_TRANSPORT_OPCODES_FIN, NULL, 0, client->config->network_timeout_ms);
+#ifdef CONFIG_ESP_WS_CLIENT_SEPARATE_TX_LOCK
+                xSemaphoreGiveRecursive(client->tx_lock);
+#endif
                 xEventGroupSetBits(client->status_bits, CLOSE_FRAME_SENT_BIT);
             }
             break;
@@ -1116,8 +1201,8 @@ static void esp_websocket_client_task(void *pv)
                 }
             }
         } else if (WEBSOCKET_STATE_WAIT_TIMEOUT == client->state) {
-            // waiting for reconnecting...
-            vTaskDelay(client->wait_timeout_ms / 2 / portTICK_PERIOD_MS);
+            // waiting for reconnection or a request to stop the client...
+            xEventGroupWaitBits(client->status_bits, REQUESTED_STOP_BIT, false, true, client->wait_timeout_ms / 2 / portTICK_PERIOD_MS);
         } else if (WEBSOCKET_STATE_CLOSING == client->state &&
                    (CLOSE_FRAME_SENT_BIT & xEventGroupGetBits(client->status_bits))) {
             ESP_LOGD(TAG, " Waiting for TCP connection to be closed by the server");
@@ -1128,10 +1213,21 @@ static void esp_websocket_client_task(void *pv)
             } else if (ret < 0) {
                 ESP_LOGW(TAG, "Connection terminated while waiting for clean TCP close");
             }
-            client->run = false;
-            client->state = WEBSOCKET_STATE_UNKNOW;
-            esp_websocket_client_dispatch_event(client, WEBSOCKET_EVENT_CLOSED, NULL, 0);
-            break;
+            if (client->config->close_reconnect && xSemaphoreTakeRecursive(client->lock, lock_timeout) == pdPASS) {
+                client->state = WEBSOCKET_STATE_WAIT_TIMEOUT;
+                client->error_handle.error_type = WEBSOCKET_ERROR_TYPE_SERVER_CLOSE;
+                esp_transport_close(client->transport);
+                esp_websocket_client_dispatch_event(client, WEBSOCKET_EVENT_CLOSED, NULL, 0);
+                client->reconnect_tick_ms = _tick_get_ms();
+                ESP_LOGI(TAG, "Reconnect after %d ms", client->wait_timeout_ms);
+                xEventGroupClearBits(client->status_bits, STOPPED_BIT | CLOSE_FRAME_SENT_BIT);
+                xSemaphoreGiveRecursive(client->lock);
+            } else {
+                client->run = false;
+                client->state = WEBSOCKET_STATE_UNKNOW;
+                esp_websocket_client_dispatch_event(client, WEBSOCKET_EVENT_CLOSED, NULL, 0);
+                break;
+            }
         }
     }
 
@@ -1168,7 +1264,7 @@ esp_err_t esp_websocket_client_start(esp_websocket_client_handle_t client)
         ESP_LOGE(TAG, "Error create websocket task");
         return ESP_FAIL;
     }
-    xEventGroupClearBits(client->status_bits, STOPPED_BIT | CLOSE_FRAME_SENT_BIT);
+    xEventGroupClearBits(client->status_bits, STOPPED_BIT | CLOSE_FRAME_SENT_BIT | REQUESTED_STOP_BIT);
     ESP_LOGI(TAG, "Started");
     return ESP_OK;
 }
@@ -1237,6 +1333,7 @@ static esp_err_t esp_websocket_client_close_with_optional_body(esp_websocket_cli
 
     // If could not close gracefully within timeout, stop the client and disconnect
     client->run = false;
+    xEventGroupSetBits(client->status_bits, REQUESTED_STOP_BIT);
     xEventGroupWaitBits(client->status_bits, STOPPED_BIT, false, true, portMAX_DELAY);
     client->state = WEBSOCKET_STATE_UNKNOW;
     return ESP_OK;

components/esp_websocket_client/examples/linux/README.md

@@ -15,20 +15,28 @@ idf.py build
 ## Example Output
 
 ```
-I (164532) websocket: [APP] Startup..
-I (164532) websocket: [APP] Free memory: 4294967295 bytes
-I (164532) websocket: [APP] IDF version: v5.3-dev-1353-gb3f7e2c8a4
-I (164538) websocket: Connecting to ws://echo.websocket.events...
-W (164538) websocket_client: `reconnect_timeout_ms` is not set, or it is less than or equal to zero, using default time out 10000 (milliseconds)
-W (164538) websocket_client: `network_timeout_ms` is not set, or it is less than or equal to zero, using default time out 10000 (milliseconds)
-I (165103) websocket: WEBSOCKET_EVENT_CONNECTED
-I (165539) websocket: Sending hello 0000
-I (165627) websocket: WEBSOCKET_EVENT_DATA
-I (165627) websocket: Received opcode=1
-W (165627) websocket: Received=hello 0000
-W (165627) websocket: Total payload length=10, data_len=10, current payload offset=0
+I (76826192) websocket: [APP] Startup..
+I (76826193) websocket: [APP] Free memory: 4294967295 bytes
+I (76826193) websocket: [APP] IDF version: v6.0-dev-2414-gab3feab1d13
+I (76826195) websocket: Connecting to wss://echo.websocket.org...
+W (76826195) websocket_client: `reconnect_timeout_ms` is not set, or it is less than or equal to zero, using default time out 10000 (milliseconds)
+W (76826195) websocket_client: `network_timeout_ms` is not set, or it is less than or equal to zero, using default time out 10000 (milliseconds)
+I (76826195) websocket: WEBSOCKET_EVENT_BEGIN
+I (76826196) websocket_client: Started
+I (76826294) esp-x509-crt-bundle: Certificate validated
+I (76827230) websocket: WEBSOCKET_EVENT_CONNECTED
+I (76827239) websocket: WEBSOCKET_EVENT_DATA
+I (76827239) websocket: Received opcode=1
+W (76827239) websocket: Received=Request served by 4d896d95b55478
+W (76827239) websocket: Total payload length=32, data_len=32, current payload offset=0
 
-I (166539) websocket: Sending fragmented message
+I (76828198) websocket: Sending hello 0000
+I (76828827) websocket: WEBSOCKET_EVENT_DATA
+I (76828827) websocket: Received opcode=1
+W (76828827) websocket: Received=hello 0000
+W (76828827) websocket: Total payload length=10, data_len=10, current payload offset=0
+
+I (76829207) websocket: Sending fragmented text message
 ```
 
 ## Coverage Reporting

components/esp_websocket_client/examples/linux/main/Kconfig.projbuild

@@ -8,8 +8,27 @@ menu "Host-test config"
 
     config WEBSOCKET_URI
           string "Websocket endpoint URI"
-          default "ws://echo.websocket.events"
+          default "wss://echo.websocket.org"
           help
               URL of websocket endpoint this example connects to and sends echo
 
+    config WS_OVER_TLS_SERVER_AUTH
+        bool "Enable WebSocket over TLS with Server Certificate Verification Only"
+        default y
+        help
+            Enables WebSocket connections over TLS (WSS) with server certificate verification.
+            The client verifies the server certificate; the server does not require a client certificate.
+
+    config WS_OVER_TLS_MUTUAL_AUTH
+        bool "Enable WebSocket over TLS with Server Client Mutual Authentification"
+        default n
+        help
+            Enables WebSocket connections over TLS (WSS) with server and client mutual certificate verification.
+
+    config WS_OVER_TLS_SKIP_COMMON_NAME_CHECK
+        bool "Skip common name(CN) check during TLS authentification"
+        default n
+        help
+            Skip Common Name (CN) check during TLS (WSS) authentication. Use only for testing.
+
 endmenu

components/esp_websocket_client/examples/linux/main/websocket_linux.c

@@ -11,6 +11,7 @@
 #include "esp_system.h"
 #include "esp_event.h"
 #include "esp_netif.h"
+#include "esp_crt_bundle.h"
 
 static const char *TAG = "websocket";
 
@@ -75,6 +76,33 @@ static void websocket_app_start(void)
 
     websocket_cfg.uri = CONFIG_WEBSOCKET_URI;
 
+#if CONFIG_WS_OVER_TLS_MUTUAL_AUTH
+    /* Configuring client certificates for mutual authentification */
+    extern const char cacert_start[] asm("_binary_ca_cert_pem_start");
+    extern const char cert_start[] asm("_binary_client_cert_pem_start");
+    extern const char cert_end[]   asm("_binary_client_cert_pem_end");
+    extern const char key_start[] asm("_binary_client_key_pem_start");
+    extern const char key_end[]   asm("_binary_client_key_pem_end");
+
+    websocket_cfg.cert_pem = cacert_start;
+    websocket_cfg.client_cert = cert_start;
+    websocket_cfg.client_cert_len = cert_end - cert_start;
+    websocket_cfg.client_key = key_start;
+    websocket_cfg.client_key_len = key_end - key_start;
+#elif CONFIG_WS_OVER_TLS_SERVER_AUTH
+    // Using certificate bundle as default server certificate source
+    websocket_cfg.crt_bundle_attach = esp_crt_bundle_attach;
+    // If using a custom certificate it could be added to certificate bundle,
+    // added to the build similar to client certificates in this examples,
+    // or read from NVS.
+    /* extern const char cacert_start[] asm("ADDED_CERTIFICATE"); */
+    /* websocket_cfg.cert_pem = cacert_start; */
+#endif
+
+#if CONFIG_WS_OVER_TLS_SKIP_COMMON_NAME_CHECK
+    websocket_cfg.skip_cert_common_name_check = true;
+#endif
+
     ESP_LOGI(TAG, "Connecting to %s...", websocket_cfg.uri);
 
     esp_websocket_client_handle_t client = esp_websocket_client_init(&websocket_cfg);

components/esp_websocket_client/examples/linux/sdkconfig.ci.coverage

@@ -3,4 +3,4 @@ CONFIG_IDF_TARGET="linux"
 CONFIG_IDF_TARGET_LINUX=y
 CONFIG_ESP_EVENT_POST_FROM_ISR=n
 CONFIG_ESP_EVENT_POST_FROM_IRAM_ISR=n
-CONFIG_WEBSOCKET_URI="ws://echo.websocket.events"
+CONFIG_WEBSOCKET_URI="wss://echo.websocket.org"

components/esp_websocket_client/examples/linux/sdkconfig.ci.linux

@@ -2,4 +2,4 @@ CONFIG_IDF_TARGET="linux"
 CONFIG_IDF_TARGET_LINUX=y
 CONFIG_ESP_EVENT_POST_FROM_ISR=n
 CONFIG_ESP_EVENT_POST_FROM_IRAM_ISR=n
-CONFIG_WEBSOCKET_URI="ws://echo.websocket.events"
+CONFIG_WEBSOCKET_URI="wss://echo.websocket.org"

components/esp_websocket_client/examples/linux/sdkconfig.defaults

@@ -2,4 +2,4 @@ CONFIG_IDF_TARGET="linux"
 CONFIG_IDF_TARGET_LINUX=y
 CONFIG_ESP_EVENT_POST_FROM_ISR=n
 CONFIG_ESP_EVENT_POST_FROM_IRAM_ISR=n
-CONFIG_WEBSOCKET_URI="ws://echo.websocket.events"
+CONFIG_WEBSOCKET_URI="wss://echo.websocket.org"

components/esp_websocket_client/examples/target/README.md

@@ -84,7 +84,7 @@ I (4472) tcpip_adapter: eth ip: 192.168.2.137, mask: 255.255.255.0, gw: 192.168.
 I (4472) example_connect: Connected to Ethernet
 I (4472) example_connect: IPv4 address: 192.168.2.137
 I (4472) example_connect: IPv6 address: fe80:0000:0000:0000:bedd:c2ff:fed4:a92b
-I (4482) WEBSOCKET: Connecting to ws://echo.websocket.events...
+I (4482) WEBSOCKET: Connecting to wss://echo.websocket.org...
 I (5012) WEBSOCKET: WEBSOCKET_EVENT_CONNECTED
 I (5492) WEBSOCKET: Sending hello 0000
 I (6052) WEBSOCKET: WEBSOCKET_EVENT_DATA
@@ -107,7 +107,7 @@ W (9162) WEBSOCKET: Received=hello 0003
 
 ## Python Flask echo server
 
-By default, the `ws://echo.websocket.events` endpoint is used. You can setup a Python websocket echo server locally and try the `ws://<your-ip>:5000` endpoint. To do this, install Flask-sock Python package
+By default, the `wss://echo.websocket.org` endpoint is used. You can setup a Python websocket echo server locally and try the `ws://<your-ip>:5000` endpoint. To do this, install Flask-sock Python package
 
 ```
 pip install flask-sock

components/esp_websocket_client/examples/target/main/Kconfig.projbuild

@@ -16,7 +16,7 @@ menu "Example Configuration"
     config WEBSOCKET_URI
         string "Websocket endpoint URI"
         depends on WEBSOCKET_URI_FROM_STRING
-        default "wss://echo.websocket.events"
+        default "wss://echo.websocket.org"
         help
             URL of websocket endpoint this example connects to and sends echo
 

components/esp_websocket_client/idf_component.yml

@@ -1,4 +1,4 @@
-version: "1.4.0"
+version: "1.5.0"
 description: WebSocket protocol client for ESP-IDF
 url: https://github.com/espressif/esp-protocols/tree/master/components/esp_websocket_client
 dependencies:

components/esp_websocket_client/include/esp_websocket_client.h

@@ -48,7 +48,8 @@ typedef enum {
     WEBSOCKET_ERROR_TYPE_NONE = 0,
     WEBSOCKET_ERROR_TYPE_TCP_TRANSPORT,
     WEBSOCKET_ERROR_TYPE_PONG_TIMEOUT,
-    WEBSOCKET_ERROR_TYPE_HANDSHAKE
+    WEBSOCKET_ERROR_TYPE_HANDSHAKE,
+    WEBSOCKET_ERROR_TYPE_SERVER_CLOSE
 } esp_websocket_error_type_t;
 
 /**
@@ -101,6 +102,7 @@ typedef struct {
     const char                  *password;                  /*!< Using for Http authentication */
     const char                  *path;                      /*!< HTTP Path, if not set, default is `/` */
     bool                        disable_auto_reconnect;     /*!< Disable the automatic reconnect function when disconnected */
+    bool                        enable_close_reconnect;     /*!< Enable reconnect after server close */
     void                        *user_context;              /*!< HTTP user data context */
     int                         task_prio;                  /*!< Websocket task priority */
     const char                 *task_name;                  /*!< Websocket task name */