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SQL Server

SSH Tunnel Timeouts and IP Preference

See more SSH Tunnel Examples

Demonstrates the ConnectTimeoutMs, IdleTimeoutMs, and PreferIpv6 properties, which govern how long the tunnel waits to connect and to transfer data, and which IP version it prefers.

Background: ConnectTimeoutMs bounds how long a connection attempt blocks — important so an unreachable server fails promptly instead of hanging — while IdleTimeoutMs guards against a stalled transfer holding a connection open indefinitely. PreferIpv6 only matters when a hostname resolves to both address families, choosing which to try first; the default prefers IPv4.

Chilkat SQL Server Downloads

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

    --  Demonstrates the SshTunnel connection-behavior properties ConnectTimeoutMs, IdleTimeoutMs, and
    --  PreferIpv6.

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

    --  Maximum time to establish the SSH connection (default 30000 ms).
    EXEC sp_OASetProperty @tunnel, 'ConnectTimeoutMs', 10000

    --  Stall timeout for tunnel data-transfer operations (default 30000 ms).
    EXEC sp_OASetProperty @tunnel, 'IdleTimeoutMs', 15000

    --  When a hostname resolves to both IPv4 and IPv6, prefer IPv6.  The default (0) prefers IPv4.
    EXEC sp_OASetProperty @tunnel, 'PreferIpv6', 1

    EXEC sp_OASetProperty @tunnel, 'DestHostname', 'db.internal.example.com'
    EXEC sp_OASetProperty @tunnel, 'DestPort', 5432

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

    DECLARE @listenPort int
    SELECT @listenPort = 1080
    EXEC sp_OAMethod @tunnel, 'BeginAccepting', @success OUT, @listenPort
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @tunnel, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @tunnel
        RETURN
      END

    PRINT 'Tunnel established.'

    DECLARE @waitForThreadExit int
    SELECT @waitForThreadExit = 1
    EXEC sp_OAMethod @tunnel, 'CloseTunnel', @success OUT, @waitForThreadExit
    IF @success = 0
      BEGIN
        EXEC sp_OAGetProperty @tunnel, 'LastErrorText', @sTmp0 OUT
        PRINT @sTmp0
        EXEC @hr = sp_OADestroy @tunnel
        RETURN
      END

    EXEC @hr = sp_OADestroy @tunnel


END
GO