C

WebSocket Connect through HTTP Proxy

See more WebSocket Examples

This example shows how to establish a WebSocket connection through an HTTP proxy server. C

#include <C_CkRest.h>
#include <C_CkSocket.h>
#include <C_CkWebSocket.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkRest rest;
    HCkSocket socket;
    BOOL bTls;
    int port;
    int maxWaitMs;
    HCkWebSocket ws;
    const char *responseBody;
    int statusCode;

    success = FALSE;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    // --------------------------------------------------
    // This example borrows the code from the REST using HTTP Proxy example.
    // We first use the Chilkat Socket object to establish a connection to the WebSocket server through an HTTP proxy.
    // Next, the Rest object uses the Socket object for its connection.
    // Finally, the WebSocket object uses the Rest object for its connection.  
    // 

    rest = CkRest_Create();
    socket = CkSocket_Create();

    // Set the HTTP proxy domain or IP address, and port.
    CkSocket_putHttpProxyHostname(socket,"192.168.1.79");
    CkSocket_putHttpProxyPort(socket,808);

    // Provide authentication to the HTTP proxy, if needed.
    CkSocket_putHttpProxyUsername(socket,"HTTP_PROXY_LOGIN");
    CkSocket_putHttpProxyPassword(socket,"HTTP_PROXY_PASSWORD");
    CkSocket_putHttpProxyAuthMethod(socket,"Basic");

    // Indicate that HTTP requests (i.e. the WebSocket opening handshake) will be sent over the socket.
    // This is important for how the HTTP proxy connection is established.
    CkSocket_putHttpProxyForHttp(socket,TRUE);

    // Connect to the websocket server through the HTTP proxy.
    bTls = FALSE;
    port = 80;
    maxWaitMs = 5000;
    success = CkSocket_Connect(socket,"some-websocket-server.com",port,bTls,maxWaitMs);
    if (success != TRUE) {
        printf("Connect Failure Error Code: %d\n",CkSocket_getConnectFailReason(socket));
        printf("%s\n",CkSocket_lastErrorText(socket));
        CkRest_Dispose(rest);
        CkSocket_Dispose(socket);
        return;
    }

    // Tell the Rest object to use the connected socket.
    success = CkRest_UseConnection(rest,socket,TRUE);
    if (success != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkSocket_Dispose(socket);
        return;
    }

    ws = CkWebSocket_Create();

    // Tell the WebSocket to use this connection.
    success = CkWebSocket_UseConnection(ws,rest);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkRest_Dispose(rest);
        CkSocket_Dispose(socket);
        CkWebSocket_Dispose(ws);
        return;
    }

    // Add the standard WebSocket open handshake headers that will be needed.
    // (This adds the required HTTP request headers to the rest object.)
    CkWebSocket_AddClientHeaders(ws);

    // Add any additional headers that might be desired.
    // Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    CkRest_AddHeader(rest,"Sec-WebSocket-Protocol","x-some-websocket-subprotocol");
    CkRest_AddHeader(rest,"Origin","http://some-websocket-server.com");

    // Do the open handshake.
    responseBody = CkRest_fullRequestNoBody(rest,"GET","/something");
    if (CkRest_getLastMethodSuccess(rest) != TRUE) {
        printf("%s\n",CkRest_lastErrorText(rest));
        CkRest_Dispose(rest);
        CkSocket_Dispose(socket);
        CkWebSocket_Dispose(ws);
        return;
    }

    // If successful, the HTTP response status code should be 101,
    // and the response body will be empty. (If it failed, we'll have a look
    // at the response body..)
    statusCode = CkRest_getResponseStatusCode(rest);
    printf("Response status code: %d\n",statusCode);

    if (statusCode != 101) {
        printf("%s\n",responseBody);
        printf("-- Failed because of unexpected response status code.\n");
        CkRest_Dispose(rest);
        CkSocket_Dispose(socket);
        CkWebSocket_Dispose(ws);
        return;
    }

    // We have the expected 101 response, so let's now validate the 
    // contents of the response, such as the value sent by the server in the
    // Sec-WebSocket-Accept header. 
    success = CkWebSocket_ValidateServerHandshake(ws);
    if (success != TRUE) {
        printf("%s\n",CkWebSocket_lastErrorText(ws));
        CkRest_Dispose(rest);
        CkSocket_Dispose(socket);
        CkWebSocket_Dispose(ws);
        return;
    }

    printf("WebSocket connection successful.\n");

    // The application may now begin sending and receiving frames on the WebSocket connection.
    // (At this point, we're done with the rest and socket objects...)

    printf("Success.\n");


    CkRest_Dispose(rest);
    CkSocket_Dispose(socket);
    CkWebSocket_Dispose(ws);

    }