arduinoWebSockets/src/WebSocketsClient.cpp

/**
 * @file WebSocketsClient.cpp
 * @date 20.05.2015
 * @author Markus Sattler
 *
 * Copyright (c) 2015 Markus Sattler. All rights reserved.
 * This file is part of the WebSockets for Arduino.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "WebSockets.h"
#include "WebSocketsClient.h"

WebSocketsClient::WebSocketsClient() {
    _cbEvent = NULL;
    _client.num = 0;
}

WebSocketsClient::~WebSocketsClient() {
    disconnect();
}

/**
 * calles to init the Websockets server
 */
void WebSocketsClient::begin(const char *host, uint16_t port, const char * url) {
    _host = host;
    _port = port;
    _fingerprint = "";

    _client.num = 0;
    _client.status = WSC_NOT_CONNECTED;
    _client.tcp = NULL;
#if (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266)
    _client.isSSL = false;
    _client.ssl = NULL;
#endif
    _client.cUrl = url;
    _client.cCode = 0;
    _client.cIsUpgrade = false;
    _client.cIsWebsocket = true;
    _client.cKey = "";
    _client.cAccept = "";
    _client.cProtocol = "";
    _client.cExtensions = "";
    _client.cVersion = 0;

#ifdef ESP8266
    randomSeed(RANDOM_REG32);
#else
    // todo find better seed
    randomSeed(millis());
#endif
}

void WebSocketsClient::begin(String host, uint16_t port, String url) {
    begin(host.c_str(), port, url.c_str());
}

#if (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266)
void WebSocketsClient::beginSSL(const char *host, uint16_t port, const char * url, const char * fingerprint) {
    begin(host, port, url);
    _client.isSSL = true;
    _fingerprint = fingerprint;
}

void WebSocketsClient::beginSSL(String host, uint16_t port, String url, String fingerprint) {
    beginSSL(host.c_str(), port, url.c_str(), fingerprint.c_str());
}
#endif

/**
 * called in arduino loop
 */
void WebSocketsClient::loop(void) {
    if(!clientIsConnected(&_client)) {

#if (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266)
        if(_client.isSSL) {
            DEBUG_WEBSOCKETS("[WS-Client] connect wss...\n");
            if(_client.ssl) {
                delete _client.ssl;
                _client.ssl = NULL;
                _client.tcp = NULL;
            }
            _client.ssl = new WiFiClientSecure();
            _client.tcp = _client.ssl;
        } else {
            DEBUG_WEBSOCKETS("[WS-Client] connect ws...\n");
            if(_client.tcp) {
                delete _client.tcp;
                _client.tcp = NULL;
            }
            _client.tcp = new WiFiClient();
        }
#else
        _client.tcp = new WEBSOCKETS_NETWORK_CLASS();
#endif

        if(!_client.tcp) {
            DEBUG_WEBSOCKETS("[WS-Client] creating Network class failed!");
            return;
        }

        if(_client.tcp->connect(_host.c_str(), _port)) {
            DEBUG_WEBSOCKETS("[WS-Client] connected to %s:%u.\n", _host.c_str(), _port);

            _client.status = WSC_HEADER;

            // set Timeout for readBytesUntil and readStringUntil
            _client.tcp->setTimeout(WEBSOCKETS_TCP_TIMEOUT);

#if (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266)
            _client.tcp->setNoDelay(true);

            if(_client.isSSL && _fingerprint.length()) {
                if(!_client.ssl->verify(_fingerprint.c_str(), _host.c_str())) {
                    DEBUG_WEBSOCKETS("[WS-Client] certificate mismatch\n");
                    WebSockets::clientDisconnect(&_client, 1000);
                    return;
                }
            }
#endif

            // send Header to Server
            sendHeader(&_client);

        } else {
            DEBUG_WEBSOCKETS("[WS-Client] connection to %s:%u Faild\n", _host.c_str(), _port);
            delay(10); //some litle delay to not flood the server
        }
    } else {
        handleClientData();
    }
}

/**
 * set callback function
 * @param cbEvent WebSocketServerEvent
 */
void WebSocketsClient::onEvent(WebSocketClientEvent cbEvent) {
    _cbEvent = cbEvent;
}

/**
 * send text data to client
 * @param num uint8_t client id
 * @param payload uint8_t *
 * @param length size_t
 * @param headerToPayload bool  (see sendFrame for more details)
 */
void WebSocketsClient::sendTXT(uint8_t * payload, size_t length, bool headerToPayload) {
    if(length == 0) {
        length = strlen((const char *) payload);
    }
    if(clientIsConnected(&_client)) {
        sendFrame(&_client, WSop_text, payload, length, true, true, headerToPayload);
    }
}

void WebSocketsClient::sendTXT(const uint8_t * payload, size_t length) {
    sendTXT((uint8_t *) payload, length);
}

void WebSocketsClient::sendTXT(char * payload, size_t length, bool headerToPayload) {
    sendTXT((uint8_t *) payload, length, headerToPayload);
}

void WebSocketsClient::sendTXT(const char * payload, size_t length) {
    sendTXT((uint8_t *) payload, length);
}

void WebSocketsClient::sendTXT(String payload) {
    sendTXT((uint8_t *) payload.c_str(), payload.length());
}

/**
 * send binary data to client
 * @param num uint8_t client id
 * @param payload uint8_t *
 * @param length size_t
 * @param headerToPayload bool  (see sendFrame for more details)
 */
void WebSocketsClient::sendBIN(uint8_t * payload, size_t length, bool headerToPayload) {
    if(clientIsConnected(&_client)) {
        sendFrame(&_client, WSop_binary, payload, length, true, true, headerToPayload);
    }
}

void WebSocketsClient::sendBIN(const uint8_t * payload, size_t length) {
    sendBIN((uint8_t *) payload, length);
}

/**
 * disconnect one client
 * @param num uint8_t client id
 */
void WebSocketsClient::disconnect(void) {
    if(clientIsConnected(&_client)) {
        WebSockets::clientDisconnect(&_client, 1000);
    }
}

//#################################################################################
//#################################################################################
//#################################################################################

/**
 *
 * @param client WSclient_t *  ptr to the client struct
 * @param opcode WSopcode_t
 * @param payload  uint8_t *
 * @param lenght size_t
 */
void WebSocketsClient::messageRecived(WSclient_t * client, WSopcode_t opcode, uint8_t * payload, size_t lenght) {
    WStype_t type = WStype_ERROR;

    switch(opcode) {
        case WSop_text:
            type = WStype_TEXT;
            break;
        case WSop_binary:
            type = WStype_BIN;
            break;
    }

    runCbEvent(type, payload, lenght);

}

/**
 * Disconnect an client
 * @param client WSclient_t *  ptr to the client struct
 */
void WebSocketsClient::clientDisconnect(WSclient_t * client) {

#if (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266)
    if(client->isSSL && client->ssl) {
        if(client->ssl->connected()) {
            client->ssl->flush();
            client->ssl->stop();
        }
        delete client->ssl;
        client->ssl = NULL;
        client->tcp = NULL;
    }
#endif

    if(client->tcp) {
        if(client->tcp->connected()) {
            client->tcp->flush();
            client->tcp->stop();
        }
        delete client->tcp;
        client->tcp = NULL;
    }

    client->cCode = 0;
    client->cKey = "";
    client->cAccept = "";
    client->cProtocol = "";
    client->cVersion = 0;
    client->cIsUpgrade = false;
    client->cIsWebsocket = false;

    client->status = WSC_NOT_CONNECTED;

    DEBUG_WEBSOCKETS("[WS-Client] client disconnected.\n");

    runCbEvent(WStype_DISCONNECTED, NULL, 0);

}

/**
 * get client state
 * @param client WSclient_t *  ptr to the client struct
 * @return true = conneted
 */
bool WebSocketsClient::clientIsConnected(WSclient_t * client) {

    if(!client->tcp) {
        return false;
    }

    if(client->tcp->connected()) {
        if(client->status != WSC_NOT_CONNECTED) {
            return true;
        }
    } else {
        // client lost
        if(client->status != WSC_NOT_CONNECTED) {
            DEBUG_WEBSOCKETS("[WS-Client] connection lost.\n");
            // do cleanup
            clientDisconnect(client);
        }
    }

    if(client->tcp) {
        // do cleanup
        clientDisconnect(client);
    }

    return false;
}

/**
 * Handel incomming data from Client
 */
void WebSocketsClient::handleClientData(void) {
    int len = _client.tcp->available();
    if(len > 0) {
        switch(_client.status) {
            case WSC_HEADER:
                handleHeader(&_client);
                break;
            case WSC_CONNECTED:
                WebSockets::handleWebsocket(&_client);
                break;
            default:
                WebSockets::clientDisconnect(&_client, 1002);
                break;
        }
    }
#ifdef ESP8266
    delay(0);
#endif
}

/**
 * send the WebSocket header to Server
 * @param client WSclient_t *  ptr to the client struct
 */
void WebSocketsClient::sendHeader(WSclient_t * client) {

    DEBUG_WEBSOCKETS("[WS-Client][sendHeader] sending header...\n");

    uint8_t randomKey[16] = { 0 };

    for(uint8_t i = 0; i < sizeof(randomKey); i++) {
        randomKey[i] = random(0xFF);
    }

    client->cKey = base64_encode(&randomKey[0], 16);

    unsigned long start = micros();

    String handshake =  "GET " + client->cUrl + " HTTP/1.1\r\n"
                        "Host: " + _host + "\r\n"
                        "Upgrade: websocket\r\n"
                        "Connection: Upgrade\r\n"
                        "User-Agent: arduino-WebSocket-Client\r\n"
                        "Sec-WebSocket-Version: 13\r\n"
                        "Sec-WebSocket-Protocol: arduino\r\n"
                        "Sec-WebSocket-Key: " + client->cKey + "\r\n";

    if(client->cExtensions.length() > 0) {
        handshake += "Sec-WebSocket-Extensions: " + client->cExtensions + "\r\n";
    }

    handshake += "\r\n";

    client->tcp->write(handshake.c_str(), handshake.length());

    DEBUG_WEBSOCKETS("[WS-Client][sendHeader] sending header... Done (%uus).\n", (micros() - start));

}

/**
 * handle the WebSocket header reading
 * @param client WSclient_t *  ptr to the client struct
 */
void WebSocketsClient::handleHeader(WSclient_t * client) {

    String headerLine = client->tcp->readStringUntil('\n');
    headerLine.trim(); // remove \r

    if(headerLine.length() > 0) {
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader] RX: %s\n", headerLine.c_str());

        if(headerLine.startsWith("HTTP/1.")) {
            // "HTTP/1.1 101 Switching Protocols"
            client->cCode = headerLine.substring(9, headerLine.indexOf(' ', 9)).toInt();
        } else if(headerLine.indexOf(':')) {
            String headerName = headerLine.substring(0, headerLine.indexOf(':'));
            String headerValue = headerLine.substring(headerLine.indexOf(':') + 2);

            if(headerName.equalsIgnoreCase("Connection")) {
                if(headerValue.indexOf("Upgrade") >= 0) {
                    client->cIsUpgrade = true;
                }
            } else if(headerName.equalsIgnoreCase("Upgrade")) {
                if(headerValue.equalsIgnoreCase("websocket")) {
                    client->cIsWebsocket = true;
                }
            } else if(headerName.equalsIgnoreCase("Sec-WebSocket-Accept")) {
                client->cAccept = headerValue;
                client->cAccept.trim(); // see rfc6455
            } else if(headerName.equalsIgnoreCase("Sec-WebSocket-Protocol")) {
                client->cProtocol = headerValue;
            } else if(headerName.equalsIgnoreCase("Sec-WebSocket-Extensions")) {
                client->cExtensions = headerValue;
            } else if(headerName.equalsIgnoreCase("Sec-WebSocket-Version")) {
                client->cVersion = headerValue.toInt();
            }
        } else {
            DEBUG_WEBSOCKETS("[WS-Client][handleHeader] Header error (%s)\n", headerLine.c_str());
        }

    } else {
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader] Header read fin.\n");
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader] Client settings:\n");

        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cURL: %s\n", client->cUrl.c_str());
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cKey: %s\n", client->cKey.c_str());

        DEBUG_WEBSOCKETS("[WS-Client][handleHeader] Server header:\n");
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cCode: %d\n", client->cCode);
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cIsUpgrade: %d\n", client->cIsUpgrade);
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cIsWebsocket: %d\n", client->cIsWebsocket);
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cAccept: %s\n", client->cAccept.c_str());
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cProtocol: %s\n", client->cProtocol.c_str());
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cExtensions: %s\n", client->cExtensions.c_str());
        DEBUG_WEBSOCKETS("[WS-Client][handleHeader]  - cVersion: %d\n", client->cVersion);

        bool ok = (client->cIsUpgrade && client->cIsWebsocket);

        if(ok) {
            switch(client->cCode) {
                case 101:  ///< Switching Protocols

                    break;
                case 403: ///< Forbidden
                    // todo handle login
                default:   ///< Server dont unterstand requrst
                    ok = false;
                    DEBUG_WEBSOCKETS("[WS-Client][handleHeader] serverCode is not 101 (%d)\n", client->cCode);
                    clientDisconnect(&_client);
                    break;
            }
        }

        if(ok) {
            if(client->cAccept.length() == 0) {
                ok = false;
            } else {
                // generate Sec-WebSocket-Accept key for check
                String sKey = acceptKey(client->cKey);
                if(sKey != client->cAccept) {
                    DEBUG_WEBSOCKETS("[WS-Client][handleHeader] Sec-WebSocket-Accept is wrong\n");
                    ok = false;
                }
            }
        }

        if(ok) {

            DEBUG_WEBSOCKETS("[WS-Client][handleHeader] Websocket connection init done.\n");

            client->status = WSC_CONNECTED;

            runCbEvent(WStype_CONNECTED, (uint8_t *) client->cUrl.c_str(), client->cUrl.length());

        } else {
            DEBUG_WEBSOCKETS("[WS-Client][handleHeader] no Websocket connection close.\n");
            client->tcp->write("This is a webSocket client!");
            clientDisconnect(client);
        }
    }
}