On 1/14/25 8:06 AM, viktor_krumm wrote:
I would have suggested this in Jira as a feature request, but I do not seem to
have access.
When using Guacamole Telnet client to access a remote host, it was duplicating
echo. This was a simple fix in src/protocols/telnet/client.c line 78. I changed
echo_enabled from 1 to 0. This required recompiling the C code. I rebuilt the
docker image for guacamole-server, and deployed the custom image instead of the
Apache image.
This feature request is to possibly expose that option in the Guacamole client
itself, like many of the VNC and SSH options. Is it possible to rewrite the C
code to accept those parameters as runtime variables? Or dockerfile build
parameters? Or is that too complicated for a simple and likely rarely used
feature?
Can you share what telnet server you're using?
This aspect of telnet is negotiated by the server and client when the
connection starts. If you're seeing duplicated echo, that suggests that
your telnet server may just not be negotiating this:
https://github.com/apache/guacamole-server/blob/32dbdfae14fb3d41d113d37f87a61d3719fa8b21/src/protocols/telnet/telnet.c#L293-L303
That, or we're sending the wrong thing in our own side of the negotiation:
https://github.com/apache/guacamole-server/blob/32dbdfae14fb3d41d113d37f87a61d3719fa8b21/src/protocols/telnet/telnet.c#L48-L60
- Mike
