On Sat, 21 Dec 2019 17:30:14 +0100 Adam Mizerski wrote:

W dniu 21.12.2019 o 16:10, Dave Howorth pisze:

...

I have a Raspberry Pi with a display and I'd like to run a program on my openSUSE PC but display the results on the pi's display. At the moment I'm running everything from the keyboard on my openSUSE box (i.e. the pi is just a display, no input).

So I have opened an ssh session to the pi and disabled access control:

$ ssh -X pi@RpiBplus pi@rpibplus's password: Linux RpiBplus 4.19.57-v7+ #1244 SMP Thu Jul 4 18:45:25 BST 2019 armv7l [etc] pi@RpiBplus:~ $ DISPLAY=:0 xhost + access control disabled, clients can connect from any host pi@RpiBplus:~ $

but if I then use another session on the openSUSE box to try to use the remote display, it fails:

$ DISPLAY=192.168.1.22:0.0 xeyes Error: Can't open display: 192.168.1.22:0.0

and just to confirm the address:

pi@RpiBplus:~ $ ip address list ... inet 192.168.1.22/24 brd 192.168.1.255 scope global noprefixroute eth0 valid_lft forever preferred_lft forever ...

Does anybody have any idea what might be preventing this connection?

FWIW I don't have a firewall on the openSUSE box, and AFAIK there isn't one on the pi (standard buster image).

Xorg usually has disabled listening on tcp, for security reasons.

Aargh! I was going to complain about Debian but I see openSUSE does it too :( I guess I can't complain too much since it's clear I haven't tried to use a remote display since whenever the change was made.

There are two ways of resolving this:

1) Make sure Xorg is listening on tcp port on public ip. Beware that this has serious security implications, especially if you disable access control completely with "xhost +".

If somebody gets onto my network, I expect I'm dead already. So I've added a new file /usr/share/lightdm/lightdm.conf.d/100-custom.conf that contains: [SeatDefaults] xserver-allow-tcp=true Then I restarted lightdm. That seems to have done the trick.

2) use ssh ability to forward unix domain sockets. On one terminal run "ssh -L /tmp/.X11-unix/X7:/tmp/.X11-unix/X0 pi@RpiBplus". On second run "DISPLAY=:7 xeyes".

Ah OK. I may have a play with that. I just read there's also an equivalent using socat. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On Sat, 21 Dec 2019 at 18:06:19 +0100, Dave Howorth wrote:

On Sat, 21 Dec 2019 17:30:14 +0100 Adam Mizerski wrote:

...

W dniu 21.12.2019 o 16:10, Dave Howorth pisze:

...

[...]

$ DISPLAY=192.168.1.22:0.0 xeyes Error: Can't open display: 192.168.1.22:0.0

I observe the same errors, not only with remote, but also with local use. X works only if DISPLAY is ":0" or ":0.0". As soon as a host address is added, the error you have described above happens.

[...] If somebody gets onto my network, I expect I'm dead already. So I've added a new file /usr/share/lightdm/lightdm.conf.d/100-custom.conf that contains:

[SeatDefaults] xserver-allow-tcp=true

So following your suggestion, I added this file, too. Does it override all occurrences of "-nolisten tcp" in the different configuration files?

Then I restarted lightdm. That seems to have done the trick.

But lightdm is not running in my system, and I don't know how to use it. Can you please explain me how to use lightdm? Can it be run together with KDE? Thanks in advance, Wolfgang -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On Sat, 21 Dec 2019 at 20:35:16 +0100, Dave Howorth wrote:

On Sat, 21 Dec 2019 20:06:02 +0100 Wolfgang Mueller wrote:

...

[...] But lightdm is not running in my system, and I don't know how to use it.

Can you please explain me how to use lightdm? Can it be run together with KDE?

lightdm is the display manager used by Raspbian. It's also running on my openSUSE box but I use LXDE. I have no idea which display manager KDE uses but whatever it is, you would need to restart that after altering its configuration file(s) in whatever way is appropriate.

I have put the same question to the KDE Linux mailing list a couple of days ago, but so far not received a reply. When they answer, telling me something appropriate, I will give you a note. Thanks again and bye, Wolfgang -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

* Patrick Shanahan [12-21-19 15:56]:

* Wolfgang Mueller [12-21-19 15:07]:

...

On Sat, 21 Dec 2019 at 20:35:16 +0100, Dave Howorth wrote:

...

On Sat, 21 Dec 2019 20:06:02 +0100 Wolfgang Mueller wrote:

...

[...] But lightdm is not running in my system, and I don't know how to use it.

Can you please explain me how to use lightdm? Can it be run together with KDE?

lightdm is the display manager used by Raspbian. It's also running on my openSUSE box but I use LXDE. I have no idea which display manager KDE uses but whatever it is, you would need to restart that after altering its configuration file(s) in whatever way is appropriate.

I have put the same question to the KDE Linux mailing list a couple of days ago, but so far not received a reply. When they answer, telling me something appropriate, I will give you a note.

kde defaults to sddm, but we have no idea what *you* installed on your box. you are the admin.

you also have google available. what do you get when you google for "which display manager am I using" ? -- (paka)Patrick Shanahan Plainfield, Indiana, USA @ptilopteri http://en.opensuse.org openSUSE Community Member facebook/ptilopteri Photos: http://wahoo.no-ip.org/piwigo paka @ IRCnet freenode -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On Sat, 21 Dec 2019 19:36:36 +0300 Andrei Borzenkov wrote:

21.12.2019 18:10, Dave Howorth пишет:

...

I have a Raspberry Pi with a display and I'd like to run a program on my openSUSE PC but display the results on the pi's display. At the moment I'm running everything from the keyboard on my openSUSE box (i.e. the pi is just a display, no input).

So I have opened an ssh session to the pi and disabled access control:

$ ssh -X pi@RpiBplus pi@rpibplus's password: Linux RpiBplus 4.19.57-v7+ #1244 SMP Thu Jul 4 18:45:25 BST 2019 armv7l [etc] pi@RpiBplus:~ $ DISPLAY=:0 xhost + access control disabled, clients can connect from any host pi@RpiBplus:~ $

but if I then use another session on the openSUSE box to try to use the remote display, it fails:

$ DISPLAY=192.168.1.22:0.0 xeyes

It is not the same as DISPLAY=:0

No, but it's just a more precise expression: Screen 0 of display 0 rather than the more generic display 0. Both ways work. I just happened to be using that form because I was testing to see if variations affected the results. Oh, and obviously it's on a remote machine instead of the local machine but that's the whole point of what I'm trying to do. Cast to a remote display. What X was designed for, among many other things. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 12/24/2019 04:26 AM, Dave Howorth wrote:

Thanks, but why should I install another unfamiliar package to get functionality that's built in to the basic display on all systems?

Anyway, it was solved a couple of days ago. Thanks anyway.

Glad you got it solved. The benefit is that the machines on the LAN do not have X-running. vncserver will start the xsession and authenticate the user. The port forwarding allows you to treat the remote port as a local port and all communication is over ssh, and on and on... In your case, if X is already running and you just need to connect (and want to do it that way) then there is no reason you can't. In the past a simple xdmcp was quite simple, but wasn't the most secure way to go. -- David C. Rankin, J.D.,P.E. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On Sun, 29 Dec 2019 14:23:14 -0500 David T-G wrote:

Dave & David, et al --

...and then David C. Rankin said... % % On 12/24/2019 04:26 AM, Dave Howorth wrote: % > % > Anyway, it was solved a couple of days ago. Thanks anyway. % % Glad you got it solved.

Indeed! And that brings me back to a question I had but didn't get a chance to ask at the time.

Are you logged in with an X session running on the Pi, Dave?

Yes there's an X server running on the pi. There's an ssh sesssion from the openSUSE PC to the pi that has run xhost +

Your original request read to me as though you weren't, which then leaves me wondering how you could throw xeyes or anything over there with nothing to catch it. Conversely, though, if you do have a session running, you could just ssh over and run whatever, right?

Well, not as far as I know, because I want to throw the results of a program that has access to a filesystem on the openSUSE PC and I don't want to remote-mount the filesystem.

% % The benefit is that the machines on the LAN do not have X-running. vncserver % will start the xsession and authenticate the user. The port forwarding allows % you to treat the remote port as a local port and all communication is over % ssh, and on and on... [snip]

Here's my other question, David. I thought that vncviewer lets me view what's going on on a system from where I'm sitting and that vncserver will throw that local display out to wherever I am. He wants to display something on that head, though, so it's almost as though the Pi should run the viewer, which would mean he's logged in. If I poke a machine running the server, can I then throw something on its display, even though that seems backwards to me?

I suspect you're right, but I didn't read it too carefully.

Thanks to you both & Happy New Year to all

:-D

-- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 2019/12/24 02:26, Dave Howorth wrote:

Anyway, it was solved a couple of days ago. Thanks anyway.

https://wiki.archlinux.org/index.php/TigerVNC

It's a workaround, not really a solution. I was going to ask are you sure your remote device is accepting traffic (is listening) for X11? I.e. is there a firewall in place? Same on the machine running xeyes -- is there a firewall in place that might be blocking outgoing X11 traffic? Seem like you missed trying basic network connectivity stuff, like DISPLAY=192.168.1.22:0.0 xeyes can the remote system ping your remote system? if you look at netstat (linux args -tln), bsdish cygwin args : -an I piped output into |grep ':60..' to find the X11 port. when something is listening, you'd see: TCP 0.0.0.0:6000 0.0.0.0:0 LISTENING or connected: TCP 192.168.3.12:6000 192.168.3.1:33722 ESTABLISHED TCP 192.168.3.12:6000 192.168.3.1:35116 ESTABLISHED Main thing -- is something 'LISTENING' on port 6000. Anyway, a bit late now, but X is generally a good thing to have running apart from a VNC/VPN. Glad you got it working for you. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org

On 2019/12/29 11:05, Dave Howorth wrote:

On Sun, 29 Dec 2019 02:27:12 -0800 L A Walsh wrote:

...

It's a workaround, not really a solution.

I was going to ask are you sure your remote device is accepting traffic (is listening) for X11? I.e. is there a firewall in place? Same on the machine running xeyes -- is there a firewall in place that might be blocking outgoing X11 traffic?

I think I answered that upthread.

...

Seem like you missed trying basic network connectivity stuff, like DISPLAY=192.168.1.22:0.0 xeyes

You mean my original message? where I said:

---- The above was meant to be a location -- where you tried the above, did you also look at ping and netstat? Sorry for unclarity, but face it I'd have to have gotten that example from your posting with the same addr and program. I was wondering about pings and netstats.

$ DISPLAY=192.168.1.22:0.0 xeyes Error: Can't open display: 192.168.1.22:0.0

...

can the remote system ping your remote system?

if you look at netstat (linux args -tln), bsdish cygwin args : -an I piped output into |grep ':60..' to find the X11 port.

when something is listening, you'd see: TCP 0.0.0.0:6000 0.0.0.0:0 LISTENING or connected: TCP 192.168.3.12:6000 192.168.3.1:33722 ESTABLISHED TCP 192.168.3.12:6000 192.168.3.1:35116 ESTABLISHED

Main thing -- is something 'LISTENING' on port 6000.

Anyway, a bit late now, but X is generally a good thing to have running apart from a VNC/VPN.

Glad you got it working for you.

Yeah, me too. There does seem to be a problem with that video driver though, whereby it works for a couple of days and then apparently (to the client) appears to continue working but nothing appears on the display. I haven't investigated yet. It's Xmas/NY :)

I've seen something like that with GL/X where some clients seem to lose syncronization sometimes. But I haven't figured out the cause. -- To unsubscribe, e-mail: opensuse+unsubscribe@opensuse.org To contact the owner, e-mail: opensuse+owner@opensuse.org