(SQL Server) WebSocket Connect through HTTP Proxy

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

Chilkat ActiveX Downloads ActiveX for 32-bit and 64-bit Windows

-- Important: See this note about string length limitations for strings returned by sp_OAMethod calls.
--
CREATE PROCEDURE ChilkatSample
AS
BEGIN
    DECLARE @hr int
    DECLARE @iTmp0 int
    -- Important: Do not use nvarchar(max).  See the warning about using nvarchar(max).
    DECLARE @sTmp0 nvarchar(4000)
    -- 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.  
    -- 

    DECLARE @rest int
    -- Use "Chilkat_9_5_0.Rest" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Rest', @rest OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @socket int
    -- Use "Chilkat_9_5_0.Socket" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.Socket', @socket OUT

    -- Set the HTTP proxy domain or IP address, and port.
    EXEC sp_OASetProperty @socket, 'HttpProxyHostname', '192.168.1.79'
    EXEC sp_OASetProperty @socket, 'HttpProxyPort', 808

    -- Provide authentication to the HTTP proxy, if needed.
    EXEC sp_OASetProperty @socket, 'HttpProxyUsername', 'HTTP_PROXY_LOGIN'
    EXEC sp_OASetProperty @socket, 'HttpProxyPassword', 'HTTP_PROXY_PASSWORD'
    EXEC sp_OASetProperty @socket, 'HttpProxyAuthMethod', '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.
    EXEC sp_OASetProperty @socket, 'HttpProxyForHttp', 1

    -- Connect to the websocket server through the HTTP proxy.
    DECLARE @bTls int
    SELECT @bTls = 0
    DECLARE @port int
    SELECT @port = 80
    DECLARE @maxWaitMs int
    SELECT @maxWaitMs = 5000
    DECLARE @success int
    EXEC sp_OAMethod @socket, 'Connect', @success OUT, 'some-websocket-server.com', @port, @bTls, @maxWaitMs
    IF @success <> 1
      BEGIN

        EXEC sp_OAGetProperty @socket, 'ConnectFailReason', @iTmp0 OUT
        PRINT 'Connect Failure Error Code: ' + @iTmp0
        EXEC sp_OAGetProperty @socket, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @socket
        RETURN
      END

    -- Tell the Rest object to use the connected socket.
    EXEC sp_OAMethod @rest, 'UseConnection', @success OUT, @socket, 1
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @socket
        RETURN
      END

    DECLARE @ws int
    -- Use "Chilkat_9_5_0.WebSocket" for versions of Chilkat < 10.0.0
    EXEC @hr = sp_OACreate 'Chilkat.WebSocket', @ws OUT

    -- Tell the WebSocket to use this connection.
    EXEC sp_OAMethod @ws, 'UseConnection', @success OUT, @rest
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @socket
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END

    -- Add the standard WebSocket open handshake headers that will be needed.
    -- (This adds the required HTTP request headers to the rest object.)
    EXEC sp_OAMethod @ws, 'AddClientHeaders', @success OUT

    -- Add any additional headers that might be desired.
    -- Two common WebSocketSpecific headers are "Sec-WebSocket-Protocol" and "Origin".
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Sec-WebSocket-Protocol', 'x-some-websocket-subprotocol'
    EXEC sp_OAMethod @rest, 'AddHeader', @success OUT, 'Origin', 'http://some-websocket-server.com'

    -- Do the open handshake.
    DECLARE @responseBody nvarchar(4000)
    EXEC sp_OAMethod @rest, 'FullRequestNoBody', @responseBody OUT, 'GET', '/something'
    EXEC sp_OAGetProperty @rest, 'LastMethodSuccess', @iTmp0 OUT
    IF @iTmp0 <> 1
      BEGIN
        EXEC sp_OAGetProperty @rest, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @socket
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END

    -- 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..)
    DECLARE @statusCode int
    EXEC sp_OAGetProperty @rest, 'ResponseStatusCode', @statusCode OUT

    PRINT 'Response status code: ' + @statusCode

    IF @statusCode <> 101
      BEGIN

        PRINT @responseBody

        PRINT '-- Failed because of unexpected response status code.'
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @socket
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END

    -- 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. 
    EXEC sp_OAMethod @ws, 'ValidateServerHandshake', @success OUT
    IF @success <> 1
      BEGIN
        EXEC sp_OAGetProperty @ws, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @rest
        EXEC @hr = sp_OADestroy @socket
        EXEC @hr = sp_OADestroy @ws
        RETURN
      END


    PRINT 'WebSocket connection successful.'

    -- 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...)


    PRINT 'Success.'

    EXEC @hr = sp_OADestroy @rest
    EXEC @hr = sp_OADestroy @socket
    EXEC @hr = sp_OADestroy @ws


END
GO