Visual FoxPro

SSH Tunnel (Port Forwarding via direct-tcpip channel)

See more SSH Examples

Demonstrates how to create an SSH tunnel to a remote hostname:port via a direct-tcpip channel. Visual FoxPro

LOCAL lnSuccess
LOCAL loSsh
LOCAL lcHostname
LOCAL lnPort
LOCAL lnChannelNum
LOCAL lcHttpReq
LOCAL lnCaseSensitive
LOCAL lcMatchStr
LOCAL lcResponseHeader
LOCAL lnNumBytesRead
LOCAL lnPollTimeoutMs
LOCAL lcHtmlBody

lnSuccess = 0

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

loSsh = CreateObject('Chilkat.Ssh')

* Connect to an SSH server:

* Hostname may be an IP address or hostname:
lcHostname = "192.168.1.117"
lnPort = 22

lnSuccess = loSsh.Connect(lcHostname,lnPort)
IF (lnSuccess <> 1) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

* Wait a max of 5 seconds when reading responses..
loSsh.IdleTimeoutMs = 5000

* Authenticate using login/password:
lnSuccess = loSsh.AuthenticatePw("chilkat","myPassword")
IF (lnSuccess <> 1) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

* Open a direct-tcpip channel.  We want the SSH server to connect
* to www.chilkatsoft.com, port 80 (i.e. the web server).
* Data sent through the SSH tunnel is forwarded to the remote
* host:port.  (Note: The remote host:port does not need to be 
* a web server.  It can be anything.  It can be your own
* customer application server that listens on a port, or any
* other type of server.)
* When we read from the SSH channel, we'll be reading data
* sent from the remote host:port (i.e. the web server in this
* example).

lnChannelNum = loSsh.OpenDirectTcpIpChannel("www.chilkatsoft.com",80)
IF (lnChannelNum < 0) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

* Build a simple HTTP GET request for http://www.chilkatsoft.com/xyz.html
lcHttpReq = "GET /xyz123.html HTTP/1.1" + CHR(13) + CHR(10) + "Host: www.chilkatsoft.com" + CHR(13) + CHR(10) + CHR(13) + CHR(10)

* Send the HTTP request:
lnSuccess = loSsh.ChannelSendString(lnChannelNum,lcHttpReq,"ansi")
IF (lnSuccess <> 1) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

* Get the HTTP response.
* First read the HTTP response header which ends with a double CRLF.
* Calling ChannelReceiveUntilMatch will receive until match string is seen,
* or until a timeout occurs (IdleTimeoutMs property).  ChannelReceiveUntilMatch
* may read beyond the match string, but it will stop reading as soon as the match
* string is seen.
lnCaseSensitive = 0
lcMatchStr = CHR(13) + CHR(10) + CHR(13) + CHR(10)
lnSuccess = loSsh.ChannelReceiveUntilMatch(lnChannelNum,lcMatchStr,"ansi",lnCaseSensitive)
IF (lnSuccess <> 1) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

* Extract the HTTP header from the receive buffer.
* (GetReceiveTextS extracts up to and including the match string from the receive buffer)

lcResponseHeader = loSsh.GetReceivedTextS(lnChannelNum,lcMatchStr,"ansi")
? "---- HTTP Response Header ----"
? lcResponseHeader

* Now get the body of the HTTP response (this is the HTML content
* of http://www.chilkatsoft.com/xyz.html
* It's possible we've already received the entire HTTP response in the
* call to ChannelReceiveUntilMatch.  Therefore, we'll poll for any remaining data
* and wait a max of .2 seconds.

lnPollTimeoutMs = 200
lnNumBytesRead = loSsh.ChannelPoll(lnChannelNum,lnPollTimeoutMs)
* We're not checking for an error here.
* A return value of -2 means that no data was available and the poll simply timed out (not an error)
* A return value of -1 indicates an error.
* A return value greater than 0 indicates that additional data was received.

? "---- HTML BODY ----"

* Extract the remainder of the accumulated data in the internal receive buffer.
* This should be our HTML body:

lcHtmlBody = loSsh.GetReceivedText(lnChannelNum,"ansi")
? lcHtmlBody

* Close the channel:
lnSuccess = loSsh.ChannelSendClose(lnChannelNum)
IF (lnSuccess <> 1) THEN
    ? loSsh.LastErrorText
    RELEASE loSsh
    CANCEL
ENDIF

* Disconnect
loSsh.Disconnect()

RELEASE loSsh