Re: orca and remote apps from ssh session

[Samuel Thibault <sthibault@debian.org>]

Hello,

Theoretically yes it could work, but nothing was made to make it easy so
far. At-spi listens on a dbus bus which is on an abstract unix socket,
and ssh can not forward a unix socket that lives in the abstract space.
Using socat can work to serve as a bridge, e.g. when we have this:

  $ xprop -root | grep AT_SPI
  AT_SPI_BUS(STRING) = "unix:abstract=/tmp/dbus-Q2svnMqMbO,guid=d35a9f6b8e4cb757b71746025e8e4965"

one can create a socket in the non-abstract space with

  $ socat ABSTRACT-CONNECT:'/tmp/dbus-Q2svnMqMbO' UNIX-LISTEN:/tmp/listen,fork

and then run 

  $ ssh myserver -R '/tmp/foobar:/tmp/listen'

which exposses the at-spi bus on /tmp/foobar on the server. And then use 

  $ export AT_SPI_BUS_ADDRESS='unix:path=/tmp/foobar'

and then try to run applications. But one gets

  (process:8353): dbind-WARNING **: 21:30:14.860: Couldn't register with accessibility bus: Did not receive a reply. Possible causes include: the remote application did not send a reply, the message bus security policy blocked the reply, the reply timeout expired, or the network connection was broken.
  (process:8353): dbind-ERROR **: 21:30:14.860: AT-SPI: Couldn't connect to accessibility bus. Is at-spi-bus-launcher running?

while it's working when ssh-ing to localhost. Looking in the exchanged
data it seems authentication is missing. A cookie-based authentication
could be used instead, but that's not implemented in at-spi.

Samuel