Tunnel

Author: mathieucarbou

examples/AsyncTunnel/AsyncTunnel.ino

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright 2016-2025 Hristo Gochkov, Mathieu Carbou, Emil Muratov
+
+//
+// Shows how to trigger an async client request from a browser request and send the client response back to the browser through websocket
+//
+
+#include <Arduino.h>
+#ifdef ESP32
+#include <AsyncTCP.h>
+#include <WiFi.h>
+#elif defined(ESP8266)
+#include <ESP8266WiFi.h>
+#include <ESPAsyncTCP.h>
+#elif defined(TARGET_RP2040) || defined(TARGET_RP2350) || defined(PICO_RP2040) || defined(PICO_RP2350)
+#include <RPAsyncTCP.h>
+#include <WiFi.h>
+#endif
+
+#include <ESPAsyncWebServer.h>
+
+#define WIFI_SSID     "IoT"
+#define WIFI_PASSWORD ""
+
+static AsyncWebServer server(80);
+static AsyncWebSocketMessageHandler wsHandler;
+static AsyncWebSocket ws("/ws", wsHandler.eventHandler());
+
+void setup() {
+  Serial.begin(115200);
+
+#ifndef CONFIG_IDF_TARGET_ESP32H2
+  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+  }
+  Serial.println("Connected to WiFi!");
+  Serial.println(WiFi.localIP());
+#endif
+
+  //
+  // HOW TO RUN THIS EXAMPLE:
+  // 1. websocat --binary ws://192.168.125.127/ws
+  // 2. curl -v "http://192.168.125.127?host=www.google.com&port=80"
+  //
+  server.on("/", HTTP_GET, [](AsyncWebServerRequest *request) {
+    if (!request->getParam("host") || !request->getParam("host")->value().length()) {
+      request->send(400, "text/plain", "Missing host parameter");
+      return;
+    }
+
+    if (!request->getParam("port") || !request->getParam("port")->value().length()) {
+      request->send(400, "text/plain", "Missing port parameter");
+      return;
+    }
+
+    const String host = request->getParam("host")->value();
+    const String port = request->getParam("port")->value();
+    AsyncClient *client = new AsyncClient();
+
+    // when client disconnects, we clear the buffer which signals the end of the chunk request
+    // note: onDisconnect also called on error
+    client->onDisconnect([](void *arg, AsyncClient *client) {
+      Serial.printf("Tunnel disconnected!\n");
+      delete client;
+    });
+
+    // register a callback when an error occurs
+    client->onError([](void *arg, AsyncClient *client, int8_t error) {
+      Serial.printf("Tunnel error: %s\n", client->errorToString(error));
+    });
+
+    // register a callback when data arrives, to accumulate it
+    client->onData([](void *arg, AsyncClient *client, void *data, size_t len) {
+      Serial.printf("Tunnel received %u bytes...\n", len);
+      ws.binaryAll(static_cast<const uint8_t *>(data), len);
+    });
+
+    client->onConnect([host, port](void *arg, AsyncClient *client) {
+      Serial.printf("Tunnel connected!\n");
+
+      client->write("GET / HTTP/1.1\r\n");
+      client->write("Host: ");
+      client->write(host.c_str());
+      client->write(":");
+      client->write(port.c_str());
+      client->write("\r\n");
+      client->write("User-Agent: ESP32\r\n");
+      client->write("Accept: */*\r\n");
+      client->write("Connection: close\r\n");
+      client->write("\r\n");
+    });
+
+    Serial.printf("Fetching: http://%s:%s...\n", host.c_str(), port.c_str());
+
+    if (!client->connect(host.c_str(), port.toInt())) {
+      Serial.printf("Failed to open tunnel!\n");
+      delete client;
+      request->send(500, "text/plain", "Failed to open tunnel");
+    } else {
+      request->send(200, "text/plain", "Tunnel opened, data will be sent through websocket\n");
+    }
+  });
+
+  wsHandler.onConnect([](AsyncWebSocket *server, AsyncWebSocketClient *client) {
+    Serial.printf("Client %" PRIu32 " connected\n", client->id());
+    server->textAll("New client: " + String(client->id()));
+  });
+
+  wsHandler.onDisconnect([](AsyncWebSocket *server, uint32_t clientId) {
+    Serial.printf("Client %" PRIu32 " disconnected\n", clientId);
+    server->textAll("Client " + String(clientId) + " disconnected");
+  });
+
+  server.addHandler(&ws);
+  server.begin();
+}
+
+void loop() {
+  delay(100);
+}

platformio.ini

@@ -2,6 +2,7 @@
 default_envs = arduino-2, arduino-3, esp8266, raspberrypi
 lib_dir = .
 ; src_dir = examples/AsyncResponseStream
+; src_dir = examples/AsyncTunnel
 ; src_dir = examples/Auth
 ; src_dir = examples/CaptivePortal
 ; src_dir = examples/CatchAllHandler
@@ -18,7 +19,7 @@ lib_dir = .
 ; src_dir = examples/Middleware
 ; src_dir = examples/Params
 ; src_dir = examples/PartitionDownloader
-src_dir = examples/PerfTests
+; src_dir = examples/PerfTests
 ; src_dir = examples/RateLimit
 ; src_dir = examples/Redirect
 ; src_dir = examples/RequestContinuation