Merge pull request #72 from david-cermak/feat/eppp_host_networking

[eppp]: Add support for host side networking

Author: david-cermak

components/wifi_remote_over_eppp/.cz.yaml

@@ -3,6 +3,6 @@ commitizen:
   bump_message: 'bump(eppp): $current_version -> $new_version'
   pre_bump_hooks: python ../../ci/changelog.py wifi_remote_over_eppp
   tag_format: wifi_rmt_eppp-v$version
-  version: 0.1.4
+  version: 0.2.0
   version_files:
   - idf_component.yml

components/wifi_remote_over_eppp/CHANGELOG.md

@@ -1,5 +1,16 @@
 # Changelog
 
+## [0.2.0](https://github.com/espressif/esp-wifi-remote/commits/wifi_rmt_eppp-v0.2.0)
+
+### Features
+
+- Support host networking with EPPP channels ([f62ca01](https://github.com/espressif/esp-wifi-remote/commit/f62ca01))
+
+### Bug Fixes
+
+- Make server CN configurable ([e5d3fb2](https://github.com/espressif/esp-wifi-remote/commit/e5d3fb2))
+- Update READMEs with latest description ([798e6f0](https://github.com/espressif/esp-wifi-remote/commit/798e6f0))
+
 ## [0.1.4](https://github.com/espressif/esp-wifi-remote/commits/wifi_rmt_eppp-v0.1.4)
 
 ### Bug Fixes

components/wifi_remote_over_eppp/Kconfig

@@ -76,9 +76,20 @@ if ESP_WIFI_REMOTE_LIBRARY_EPPP
                 SPI frequency in Hz.
     endif
 
+    config WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+        bool "Enable host side netif"
+        default n
+        select EPPP_LINK_CHANNELS_SUPPORT
+        help
+            Enable host side netifwork interface (Remote WiFi station) that uses EPPP channels
+            for sending and receiving 802.3 frames over EPPP.
+            Enable this if host behind NAT would cause issues.
+            Downside is that the slave side does not have a direct access to the internet.
+
     config WIFI_RMT_OVER_EPPP_NETIF_PRIORITY
         int "Routing priority of eppp netif"
         default 100
+        default 50 if WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
         range 0 256
         help
             Set the priority of the wifi-remote netif.

components/wifi_remote_over_eppp/idf_component.yml

@@ -1,4 +1,4 @@
-version: 0.1.4
+version: 0.2.0
 url: https://github.com/espressif/esp-wifi-remote/components/wifi_remote_over_eppp
 description: EPPP based implementation of wifi_remote APIs
 license: Apache-2.0

components/wifi_remote_over_eppp/src/wifi_remote_rpc_client.cpp

@@ -15,6 +15,9 @@
 #include "freertos/FreeRTOS.h"
 #include "freertos/event_groups.h"
 #include "wifi_remote_rpc_params.h"
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+#include "esp_wifi_remote.h"
+#endif
 
 extern "C" esp_netif_t *wifi_remote_eppp_init(eppp_type_t role);
 
@@ -118,6 +121,12 @@ class RpcInstance {
     esp_err_t init()
     {
         ESP_RETURN_ON_FALSE(netif = wifi_remote_eppp_init(EPPP_CLIENT), ESP_FAIL, TAG, "Failed to connect to EPPP server");
+
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+        ESP_RETURN_ON_ERROR(eppp_add_channels(netif, &channel_tx, channel_rx, this), TAG, "Failed to add EPPP channel");
+        ESP_RETURN_ON_ERROR(esp_wifi_remote_channel_set(WIFI_IF_STA, (void*)this, wifi_remote_tx), TAG, "Failed to configure WiFi remote channel");
+#endif
+
         ESP_RETURN_ON_ERROR(esp_event_handler_register(IP_EVENT, IP_EVENT_PPP_GOT_IP, got_ip, this), TAG, "Failed to register event");
         ESP_RETURN_ON_ERROR(sync.init(), TAG, "Failed to init sync primitives");
         ESP_RETURN_ON_ERROR(rpc.init(), TAG, "Failed to init RPC engine");
@@ -151,6 +160,7 @@ class RpcInstance {
     esp_err_t process_wifi_event(RpcHeader &header)
     {
         auto event_id = rpc.get_payload<int32_t>(api_id::WIFI_EVENT, header);
+        ESP_LOGI(TAG, "Processing WiFi event with id %" PRIi32, event_id);
         ESP_RETURN_ON_ERROR(esp_event_post(WIFI_REMOTE_EVENT, event_id, nullptr, 0, 0), TAG, "Failed to post WiFi event");
         return ESP_OK;
     }
@@ -200,6 +210,22 @@ class RpcInstance {
         auto instance = static_cast<RpcInstance *>(ctx);
         instance->sync.notify(instance->sync.restart);
     }
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+    static esp_err_t channel_rx(esp_netif_t *netif, int nr, void *buffer, size_t len)
+    {
+        auto instance = static_cast<RpcInstance *>(eppp_get_context(netif));
+        return esp_wifi_remote_channel_rx(instance, buffer, nullptr, len);
+    }
+    static esp_err_t wifi_remote_tx(void *h, void *buffer, size_t len)
+    {
+        auto instance = static_cast<RpcInstance *>(h);
+        if (instance->channel_tx) {
+            return instance->channel_tx(instance->netif, 1, buffer, len);
+        }
+        return ESP_FAIL;
+    }
+    eppp_channel_fn_t channel_tx{nullptr};
+#endif // CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
     esp_netif_t *netif{nullptr};
 };
 

components/wifi_remote_over_eppp/src/wifi_remote_rpc_server.cpp

@@ -1,11 +1,10 @@
 /*
- * SPDX-FileCopyrightText: 2024 Espressif Systems (Shanghai) CO LTD
+ * SPDX-FileCopyrightText: 2024-2025 Espressif Systems (Shanghai) CO LTD
  *
  * SPDX-License-Identifier: Apache-2.0
  */
 #include <netdb.h>
 #include <memory>
-#include <cerrno>
 #include <sys/socket.h>
 #include "esp_log.h"
 #include "esp_check.h"
@@ -17,6 +16,9 @@
 #include "lwip/apps/snmp.h"
 #include "esp_vfs.h"
 #include "esp_vfs_eventfd.h"
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+#include "esp_private/wifi.h"
+#endif
 
 extern "C" esp_netif_t *wifi_remote_eppp_init(eppp_type_t role);
 
@@ -30,6 +32,10 @@ const unsigned char crt[] = "-----BEGIN CERTIFICATE-----\n" CONFIG_WIFI_RMT_OVER
 const unsigned char key[] = "-----BEGIN PRIVATE KEY-----\n" CONFIG_WIFI_RMT_OVER_EPPP_SERVER_KEY "\n-----END PRIVATE KEY-----";
 // TODO: Add option to supply keys and certs via a global symbol (file)
 
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+RpcInstance* get_instance();
+#endif
+
 }
 
 using namespace server;
@@ -109,9 +115,16 @@ class RpcInstance {
     esp_err_t init()
     {
         ESP_RETURN_ON_FALSE(netif = wifi_remote_eppp_init(EPPP_SERVER), ESP_FAIL, TAG, "Failed to init EPPP connection");
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+        ESP_RETURN_ON_ERROR(eppp_add_channels(netif, &channel_tx, channel_rx, this), TAG, "Failed to add EPPP channel");
+#endif
+
         ESP_RETURN_ON_ERROR(start_server(), TAG, "Failed to start RPC server");
         ESP_RETURN_ON_ERROR(rpc.init(), TAG, "Failed to init RPC engine");
+#ifndef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+        // No need to NAPT for client (host) side networking
         ESP_RETURN_ON_ERROR(esp_netif_napt_enable(netif), TAG, "Failed to enable NAPT");
+#endif
         ESP_RETURN_ON_ERROR(sync.init(), TAG, "Failed to init event queue");
         ESP_RETURN_ON_ERROR(esp_event_handler_register(WIFI_EVENT, ESP_EVENT_ANY_ID, handler, this), TAG, "Failed to register event");
         ESP_RETURN_ON_ERROR(esp_event_handler_register(IP_EVENT, ESP_EVENT_ANY_ID, handler, this), TAG, "Failed to register event");
@@ -120,6 +133,26 @@ class RpcInstance {
     Sync sync;
 private:
     esp_netif_t *netif{nullptr};
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+    bool started{false};
+    eppp_channel_fn_t channel_tx{nullptr};
+    static esp_err_t channel_rx(esp_netif_t *netif, int nr, void *buffer, size_t len)
+    {
+        if (get_instance()->started) {
+            return esp_wifi_internal_tx(WIFI_IF_STA, buffer, len);
+        }
+        return ESP_OK;
+    }
+    static esp_err_t wifi_receive(void *buffer, uint16_t len, void *eb)
+    {
+        if (get_instance()->channel_tx) {
+            auto ret = get_instance()->channel_tx(get_instance()->netif, 1, buffer, len);
+            esp_wifi_internal_free_rx_buffer(eb);
+            return ret;
+        }
+        return ESP_OK;
+    }
+#endif
     static void task(void *ctx)
     {
         auto instance = static_cast<RpcInstance *>(ctx);
@@ -289,7 +322,11 @@ class RpcInstance {
             if (header.size != 0) {
                 return ESP_FAIL;
             }
-
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+            esp_wifi_internal_reg_rxcb(WIFI_IF_STA, wifi_receive);
+            esp_wifi_internal_reg_netstack_buf_cb(esp_netif_netstack_buf_ref, esp_netif_netstack_buf_free);
+            started = true;
+#endif
             auto ret = esp_wifi_start();
             if (rpc.send(api_id::START, &ret) != ESP_OK) {
                 return ESP_FAIL;
@@ -356,6 +393,14 @@ class RpcInstance {
 
 namespace server {
 constinit RpcInstance instance;
+
+#ifdef CONFIG_WIFI_RMT_OVER_EPPP_HOST_SIDE_NETIF
+// This is needed in wifi-callbacks which lack context param
+RpcInstance* get_instance()
+{
+    return &server::instance;
+}
+#endif
 }
 
 RpcInstance *RpcEngine::init_server()