PowerBuilder

Stop an SSH Tunnel Listener (StopAccepting)

Demonstrates the Chilkat SshTunnel.StopAccepting method, which stops the local listener so no new client connections are accepted. The only argument (waitForThread) selects whether to wait for the listener thread to exit. Existing forwarded clients remain connected.

Background: The distinction from CloseTunnel is the point: StopAccepting closes only the front door, leaving already-connected clients to finish their transfers undisturbed. That makes it the graceful way to drain a tunnel — stop taking new work, let existing work complete, then close — rather than cutting everyone off at once.

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integer li_rc
integer li_Success
oleobject loo_Tunnel
integer li_SshPort
string ls_Password
integer li_ListenPort
integer li_WaitForThread
integer li_WaitForThreadExit

li_Success = 0

//  Demonstrates the SshTunnel.StopAccepting method, which stops the local listener so that no new
//  client connections are accepted.  The only argument (waitForThread) selects whether to wait for
//  the listener thread to exit.  Existing forwarded clients remain connected.

loo_Tunnel = create oleobject
li_rc = loo_Tunnel.ConnectToNewObject("Chilkat.SshTunnel")
if li_rc < 0 then
    destroy loo_Tunnel
    MessageBox("Error","Connecting to COM object failed")
    return
end if

loo_Tunnel.DestHostname = "db.internal.example.com"
loo_Tunnel.DestPort = 5432

li_SshPort = 22
li_Success = loo_Tunnel.Connect("ssh.example.com",li_SshPort)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

//  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.
ls_Password = "mySshPassword"

li_Success = loo_Tunnel.AuthenticatePw("mySshLogin",ls_Password)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

li_ListenPort = 1080
li_Success = loo_Tunnel.BeginAccepting(li_ListenPort)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

//  ... the tunnel runs for a while ...

//  Stop accepting NEW connections, but leave already-connected clients running.
li_WaitForThread = 1
li_Success = loo_Tunnel.StopAccepting(li_WaitForThread)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if

Write-Debug "The listener has stopped; existing clients continue."

li_WaitForThreadExit = 1
li_Success = loo_Tunnel.CloseTunnel(li_WaitForThreadExit)
if li_Success = 0 then
    Write-Debug loo_Tunnel.LastErrorText
    destroy loo_Tunnel
    return
end if



destroy loo_Tunnel