webserver hook: allow to handle external http protocol (#7459)

d-a-v · web-flow · commit 33083861c80b · 2020-07-28T23:34:26.000+02:00
* webhook api * simplify webserver debug printouts, move text to flash * Hook examples in HelloServer example * print executable code address in example * simplify example per @mcspr suggestion
diff --git a/cores/esp8266/core_esp8266_features.h b/cores/esp8266/core_esp8266_features.h
@@ -92,7 +92,19 @@ inline uint32_t esp_get_cycle_count() {
   __asm__ __volatile__("rsr %0,ccount":"=a"(ccount));
   return ccount;
 }
-#endif // not CORE_MOCK
+
+inline uint32_t esp_get_program_counter() __attribute__((always_inline));
+inline uint32_t esp_get_program_counter() {
+  uint32_t pc;
+  __asm__ __volatile__("movi %0, ." : "=r" (pc) : : ); // ©earlephilhower
+  return pc;
+}
+
+#else // CORE_MOCK
+
+inline uint32_t esp_get_program_counter() { return 0; }
+
+#endif // CORE_MOCK
 
 
 // Tools for preloading code into the flash cache
diff --git a/libraries/ESP8266WebServer/examples/HelloServer/HelloServer.ino b/libraries/ESP8266WebServer/examples/HelloServer/HelloServer.ino
@@ -17,7 +17,7 @@ const int led = 13;
 
 void handleRoot() {
   digitalWrite(led, 1);
-  server.send(200, "text/plain", "hello from esp8266!");
+  server.send(200, "text/plain", "hello from esp8266!\r\n");
   digitalWrite(led, 0);
 }
 
@@ -86,6 +86,66 @@ void setup(void) {
 
   server.onNotFound(handleNotFound);
 
+  /////////////////////////////////////////////////////////
+  // Hook examples
+
+  server.addHook([](const String & method, const String & url, WiFiClient * client, ESP8266WebServer::ContentTypeFunction contentType) {
+    (void)method;      // GET, PUT, ...
+    (void)url;         // example: /root/myfile.html
+    (void)client;      // the webserver tcp client connection
+    (void)contentType; // contentType(".html") => "text/html"
+    Serial.printf("A useless web hook has passed\n");
+    Serial.printf("(this hook is in 0x%08x area (401x=IRAM 402x=FLASH))\n", esp_get_program_counter());
+    return ESP8266WebServer::CLIENT_REQUEST_CAN_CONTINUE;
+  });
+
+  server.addHook([](const String&, const String & url, WiFiClient*, ESP8266WebServer::ContentTypeFunction) {
+    if (url.startsWith("/fail")) {
+      Serial.printf("An always failing web hook has been triggered\n");
+      return ESP8266WebServer::CLIENT_MUST_STOP;
+    }
+    return ESP8266WebServer::CLIENT_REQUEST_CAN_CONTINUE;
+  });
+
+  server.addHook([](const String&, const String & url, WiFiClient * client, ESP8266WebServer::ContentTypeFunction) {
+    if (url.startsWith("/dump")) {
+      Serial.printf("The dumper web hook is on the run\n");
+
+      // Here the request is not interpreted, so we cannot for sure
+      // swallow the exact amount matching the full request+content,
+      // hence the tcp connection cannot be handled anymore by the
+      // webserver.
+#ifdef STREAMTO_API
+      // we are lucky
+      client->toWithTimeout(Serial, 500);
+#else
+      auto last = millis();
+      while ((millis() - last) < 500) {
+        char buf[32];
+        size_t len = client->read((uint8_t*)buf, sizeof(buf));
+        if (len > 0) {
+          Serial.printf("(<%d> chars)", (int)len);
+          Serial.write(buf, len);
+          last = millis();
+        }
+      }
+#endif
+      // Two choices: return MUST STOP and webserver will close it
+      //                       (we already have the example with '/fail' hook)
+      // or                  IS GIVEN and webserver will forget it
+      // trying with IS GIVEN and storing it on a dumb WiFiClient.
+      // check the client connection: it should not immediately be closed
+      // (make another '/dump' one to close the first)
+      Serial.printf("\nTelling server to forget this connection\n");
+      static WiFiClient forgetme = *client; // stop previous one if present and transfer client refcounter
+      return ESP8266WebServer::CLIENT_IS_GIVEN;
+    }
+    return ESP8266WebServer::CLIENT_REQUEST_CAN_CONTINUE;
+  });
+
+  // Hook examples
+  /////////////////////////////////////////////////////////
+
   server.begin();
   Serial.println("HTTP server started");
 }
diff --git a/libraries/ESP8266WebServer/src/ESP8266WebServer-impl.h b/libraries/ESP8266WebServer/src/ESP8266WebServer-impl.h
@@ -28,20 +28,12 @@
 #include "FS.h"
 #include "detail/RequestHandlersImpl.h"
 
-//#define DEBUG_ESP_HTTP_SERVER
-#ifdef DEBUG_ESP_PORT
-#define DEBUG_OUTPUT DEBUG_ESP_PORT
-#else
-#define DEBUG_OUTPUT Serial
-#endif
-
 static const char AUTHORIZATION_HEADER[] PROGMEM = "Authorization";
 static const char qop_auth[] PROGMEM = "qop=auth";
 static const char qop_auth_quoted[] PROGMEM = "qop=\"auth\"";
 static const char WWW_Authenticate[] PROGMEM = "WWW-Authenticate";
 static const char Content_Length[] PROGMEM = "Content-Length";
 
-
 template <typename ServerType>
 ESP8266WebServerTemplate<ServerType>::ESP8266WebServerTemplate(IPAddress addr, int port)
 : _server(addr, port)
@@ -171,9 +163,7 @@ bool ESP8266WebServerTemplate<ServerType>::authenticateDigest(const String& user
     String authReq = header(FPSTR(AUTHORIZATION_HEADER));
     if(authReq.startsWith(F("Digest"))) {
       authReq = authReq.substring(7);
-      #ifdef DEBUG_ESP_HTTP_SERVER
-      DEBUG_OUTPUT.println(authReq);
-      #endif
+      DBGWS("%s\n", authReq.c_str());
       String _username = _extractParam(authReq,F("username=\""));
       if(!_username.length() || _username != String(username)) {
         authReq = "";
@@ -200,9 +190,7 @@ bool ESP8266WebServerTemplate<ServerType>::authenticateDigest(const String& user
         _nc = _extractParam(authReq, F("nc="), ',');
         _cnonce = _extractParam(authReq, F("cnonce=\""));
       }
-      #ifdef DEBUG_ESP_HTTP_SERVER
-      DEBUG_OUTPUT.println("Hash of user:realm:pass=" + H1);
-      #endif
+      DBGWS("Hash of user:realm:pass=%s\n", H1.c_str());
       MD5Builder md5;
       md5.begin();
       if(_currentMethod == HTTP_GET){
@@ -218,9 +206,7 @@ bool ESP8266WebServerTemplate<ServerType>::authenticateDigest(const String& user
       }
       md5.calculate();
       String _H2 = md5.toString();
-      #ifdef DEBUG_ESP_HTTP_SERVER
-      DEBUG_OUTPUT.println("Hash of GET:uri=" + _H2);
-      #endif
+      DBGWS("Hash of GET:uri=%s\n", _H2.c_str());
       md5.begin();
       if(authReq.indexOf(FPSTR(qop_auth)) != -1 || authReq.indexOf(FPSTR(qop_auth_quoted)) != -1) {
         md5.add(H1 + ':' + _nonce + ':' + _nc + ':' + _cnonce + F(":auth:") + _H2);
@@ -229,9 +215,7 @@ bool ESP8266WebServerTemplate<ServerType>::authenticateDigest(const String& user
       }
       md5.calculate();
       String _responsecheck = md5.toString();
-      #ifdef DEBUG_ESP_HTTP_SERVER
-      DEBUG_OUTPUT.println("The Proper response=" +_responsecheck);
-      #endif
+      DBGWS("The Proper response=%s\n", _responsecheck.c_str());
       if(_response == _responsecheck){
         authReq = "";
         return true;
@@ -315,9 +299,7 @@ void ESP8266WebServerTemplate<ServerType>::handleClient() {
       return;
     }
 
-#ifdef DEBUG_ESP_HTTP_SERVER
-    DEBUG_OUTPUT.println("New client");
-#endif
+    DBGWS("New client\n");
 
     _currentClient = client;
     _currentStatus = HC_WAIT_READ;
@@ -327,6 +309,13 @@ void ESP8266WebServerTemplate<ServerType>::handleClient() {
   bool keepCurrentClient = false;
   bool callYield = false;
 
+  DBGWS("http-server loop: conn=%d avail=%d status=%s\n",
+    _currentClient.connected(), _currentClient.available(),
+    _currentStatus==HC_NONE?"none":
+    _currentStatus==HC_WAIT_READ?"wait-read":
+    _currentStatus==HC_WAIT_CLOSE?"wait-close":
+    "??");
+
   if (_currentClient.connected() || _currentClient.available()) {
     if (_currentClient.available() && _keepAlive) {
       _currentStatus = HC_WAIT_READ;
@@ -339,34 +328,57 @@ void ESP8266WebServerTemplate<ServerType>::handleClient() {
     case HC_WAIT_READ:
       // Wait for data from client to become available
       if (_currentClient.available()) {
-        if (_parseRequest(_currentClient)) {
+        switch (_parseRequest(_currentClient))
+        {
+        case CLIENT_REQUEST_CAN_CONTINUE:
           _currentClient.setTimeout(HTTP_MAX_SEND_WAIT);
           _contentLength = CONTENT_LENGTH_NOT_SET;
           _handleRequest();
-
-          if (_currentClient.connected()) {
+          /* fallthrough */
+        case CLIENT_REQUEST_IS_HANDLED:
+          if (_currentClient.connected() || _currentClient.available()) {
             _currentStatus = HC_WAIT_CLOSE;
             _statusChange = millis();
             keepCurrentClient = true;
           }
-        }
-      } else { // !_currentClient.available()
+          else
+            DBGWS("webserver: peer has closed after served\n");
+          break;
+        case CLIENT_MUST_STOP:
+          DBGWS("Close client\n");
+          _currentClient.stop();
+          break;
+        case CLIENT_IS_GIVEN:
+          // client must not be stopped but must not be handled here anymore
+          // (example: tcp connection given to websocket)
+          DBGWS("Give client\n");
+          break;
+        } // switch _parseRequest()
+      } else {
+        // !_currentClient.available(): waiting for more data
         if (millis() - _statusChange <= HTTP_MAX_DATA_WAIT) {
           keepCurrentClient = true;
         }
+        else
+          DBGWS("webserver: closing after read timeout\n");
         callYield = true;
       }
       break;
     case HC_WAIT_CLOSE:
       // Wait for client to close the connection
-      if (millis() - _statusChange <= HTTP_MAX_CLOSE_WAIT) {
+      if (!_server.available() && (millis() - _statusChange <= HTTP_MAX_CLOSE_WAIT)) {
         keepCurrentClient = true;
         callYield = true;
+        if (_currentClient.available())
+            // continue serving current client
+            _currentStatus = HC_WAIT_READ;
       }
-    }
+      break;
+    } // switch _currentStatus
   }
 
   if (!keepCurrentClient) {
+    DBGWS("Drop client\n");
     _currentClient = ClientType();
     _currentStatus = HC_NONE;
     _currentUpload.reset();
@@ -687,17 +699,13 @@ template <typename ServerType>
 void ESP8266WebServerTemplate<ServerType>::_handleRequest() {
   bool handled = false;
   if (!_currentHandler){
-#ifdef DEBUG_ESP_HTTP_SERVER
-    DEBUG_OUTPUT.println("request handler not found");
-#endif
+    DBGWS("request handler not found\n");
   }
   else {
     handled = _currentHandler->handle(*this, _currentMethod, _currentUri);
-#ifdef DEBUG_ESP_HTTP_SERVER
     if (!handled) {
-      DEBUG_OUTPUT.println("request handler failed to handle request");
+      DBGWS("request handler failed to handle request\n");
     }
-#endif
   }
   if (!handled && _notFoundHandler) {
     _notFoundHandler();
diff --git a/libraries/ESP8266WebServer/src/ESP8266WebServer.h b/libraries/ESP8266WebServer/src/ESP8266WebServer.h
@@ -26,11 +26,24 @@
 
 #include <functional>
 #include <memory>
+#include <functional>
 #include <ESP8266WiFi.h>
 #include <FS.h>
 #include "detail/mimetable.h"
 #include "Uri.h"
 
+//#define DEBUG_ESP_HTTP_SERVER
+
+#ifdef DEBUG_ESP_HTTP_SERVER
+#ifdef DEBUG_ESP_PORT
+#define DBGWS(f,...) do { DEBUG_ESP_PORT.printf(PSTR(f), ##__VA_ARGS__); } while (0)
+#else
+#define DBGWS(f,...) do { Serial.printf(PSTR(f), ##__VA_ARGS__); } while (0)
+#endif
+#else
+#define DBGWS(x...) do { (void)0; } while (0)
+#endif
+
 enum HTTPMethod { HTTP_ANY, HTTP_GET, HTTP_HEAD, HTTP_POST, HTTP_PUT, HTTP_PATCH, HTTP_DELETE, HTTP_OPTIONS };
 enum HTTPUploadStatus { UPLOAD_FILE_START, UPLOAD_FILE_WRITE, UPLOAD_FILE_END,
                         UPLOAD_FILE_ABORTED };
@@ -80,6 +93,9 @@ class ESP8266WebServerTemplate
   using ClientType = typename ServerType::ClientType;
   using RequestHandlerType = RequestHandler<ServerType>;
   using WebServerType = ESP8266WebServerTemplate<ServerType>;
+  enum ClientFuture { CLIENT_REQUEST_CAN_CONTINUE, CLIENT_REQUEST_IS_HANDLED, CLIENT_MUST_STOP, CLIENT_IS_GIVEN };
+  typedef String (*ContentTypeFunction) (const String&);
+  using HookFunction = std::function<ClientFuture(const String& method, const String& url, WiFiClient* client, ContentTypeFunction contentType)>;
 
   void begin();
   void begin(uint16_t port);
@@ -200,11 +216,25 @@ class ESP8266WebServerTemplate
 
   static String responseCodeToString(const int code);
 
+  void addHook (HookFunction hook) {
+    if (_hook) {
+      auto previousHook = _hook;
+      _hook = [previousHook, hook](const String& method, const String& url, WiFiClient* client, ContentTypeFunction contentType) {
+          auto whatNow = previousHook(method, url, client, contentType);
+          if (whatNow == CLIENT_REQUEST_CAN_CONTINUE)
+            return hook(method, url, client, contentType);
+          return whatNow;
+        };
+    } else {
+      _hook = hook;
+    }
+  }
+
 protected:
   void _addRequestHandler(RequestHandlerType* handler);
   void _handleRequest();
   void _finalizeResponse();
-  bool _parseRequest(ClientType& client);
+  ClientFuture _parseRequest(ClientType& client);
   void _parseArguments(const String& data);
   int _parseArgumentsPrivate(const String& data, std::function<void(String&,String&,const String&,int,int,int,int)> handler);
   bool _parseForm(ClientType& client, const String& boundary, uint32_t len);
@@ -261,8 +291,7 @@ class ESP8266WebServerTemplate
   String           _sopaque;
   String           _srealm;  // Store the Auth realm between Calls
 
-  
-
+  HookFunction     _hook;
 };
 
 
diff --git a/libraries/ESP8266WebServer/src/Parsing-impl.h b/libraries/ESP8266WebServer/src/Parsing-impl.h
