SQL Server

Get the Type of an Active SSH Channel

Demonstrates the Chilkat Ssh.GetChannelType method, which returns the type of the channel at a zero-based enumeration index. The only argument is the index — an enumeration position, not a channel number. Values include session, x11, forwarded-tcpip, and direct-tcpip.

Background: Paired with GetChannelNumber, this turns the channel collection into a readable inventory of what a connection is currently doing — which channels are running commands (session) versus tunneling TCP traffic (direct-tcpip). That is valuable for diagnostics and for application code that manages several channel kinds at once. An out-of-range index causes the string-returning method to report failure.

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SQL Server

-- 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
    DECLARE @sTmp0 nvarchar(4000)
    DECLARE @success int
    SELECT @success = 0

    --  Demonstrates the Ssh.GetChannelType method, which returns the type of the channel at a
    --  zero-based enumeration index.  The only argument is the index, which is an enumeration
    --  position and not a channel number.  Values include "session" and "direct-tcpip".

    DECLARE @ssh int
    EXEC @hr = sp_OACreate 'Chilkat.Ssh', @ssh OUT
    IF @hr <> 0
    BEGIN
        PRINT 'Failed to create ActiveX component'
        RETURN
    END

    DECLARE @sshPort int
    SELECT @sshPort = 22
    EXEC sp_OAMethod @ssh, 'Connect', @success OUT, 'ssh.example.com', @sshPort
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @ssh
        RETURN
      END

    --  Normally you would not hard-code the password in source.  You should instead obtain it
    --  from an interactive prompt, environment variable, or a secrets vault.
    DECLARE @password nvarchar(4000)
    SELECT @password = 'mySshPassword'

    EXEC sp_OAMethod @ssh, 'AuthenticatePw', @success OUT, 'mySshLogin', @password
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @ssh
        RETURN
      END

    DECLARE @channelNum int
    EXEC sp_OAMethod @ssh, 'OpenSessionChannel', @channelNum OUT
    IF @channelNum < 0
      BEGIN
        EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @ssh
        RETURN
      END

    --  Enumerate the active channels and report each one's number and type.
    DECLARE @n int
    EXEC sp_OAGetProperty @ssh, 'NumOpenChannels', @n OUT
    DECLARE @i int

    SELECT @i = 0
    WHILE @i <= @n - 1
      BEGIN
        DECLARE @chNum int
        EXEC sp_OAMethod @ssh, 'GetChannelNumber', @chNum OUT, @i
        DECLARE @chType nvarchar(4000)
        EXEC sp_OAMethod @ssh, 'GetChannelType', @chType OUT, @i
        EXEC sp_OAGetProperty @ssh, 'LastMethodSuccess', @iTmp0 OUT
        IF @iTmp0 = 0
          BEGIN
            EXEC sp_OAGetProperty @ssh, 'LastErrorText', @sTmp0 OUT
            PRINT @sTmp0
            EXEC @hr = sp_OADestroy @ssh
            RETURN
          END


        PRINT 'Channel ' + @chNum + ' is of type ' + @chType
        SELECT @i = @i + 1
      END

    EXEC sp_OAMethod @ssh, 'Disconnect', NULL

    EXEC @hr = sp_OADestroy @ssh


END
GO