Re: usb snooper
On Wednesday 27 November 2019 01:55:50 Reco wrote:
> Hi.
>
> On Tue, Nov 26, 2019 at 05:05:13PM -0500, Gene Heskett wrote:
> > Greetings all;
> >
> > I have what I believe to be noise or crosstalk causing interference
> > between a wireless keyboard mouse and the machine they are
> > controlling, which is an rpi4. The app itself doesn't expose any
> > usb traffic to the user. The effect is as if the finger was lifted
> > from the key for a hundred ms or so at random intervals.
> >
> > So what, on an armhf raspi, do we have for a usbsnoop?
>
> /usr/sbin/tcpdump -D
>
> </thread>
>
> Reco
Thanks Reco, I had to install it, but then reread the man page a couple
times, but I don't get it yet: (screen snip)
pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ /usr/sbin/tcpdump -D 8
1.eth0 [Up, Running]
2.any (Pseudo-device that captures on all interfaces) [Up, Running]
3.lo [Up, Running, Loopback]
4.wlan0
5.bluetooth0 (Bluetooth adapter number 0)
6.nflog (Linux netfilter log (NFLOG) interface)
7.nfqueue (Linux netfilter queue (NFQUEUE) interface)
8.usbmon1 (USB bus number 1)
9.usbmon2 (USB bus number 2)
10.usbmon3 (USB bus number 3)
Then to get perms:
i@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump 8
tcpdump: syntax error in filter expression: syntax error
pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump 9
tcpdump: syntax error in filter expression: syntax error
pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump 10
tcpdump: syntax error in filter expression: syntax error
Each such syntax error takes a couple secs to be reported. and I get a
repeat for 2.
Obviously I'm not doing something right yet. ??
Thanks
Cheers, Gene Heskett
--
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Genes Web page <http://geneslinuxbox.net:6309/gene>
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