Re: usb snooper
On Wednesday 27 November 2019 07:11:26 Reco wrote:
> On Wed, Nov 27, 2019 at 07:03:13AM -0500, Gene Heskett wrote:
> > 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>
> >
> > 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)
>
> tcpdump(8) says:
>
> -i interface
> --interface=interface
> Listen on interface ...
> If the -D flag is supported, an interface number as printed by
> that flag can be used as the interface argument, if no interface on
> the system has that number as a name.
>
> So,
>
> sudo /usr/sbin/tcpdump -i 8
>
> Reco
Doesn't look as if it will work with this preempt-rt kernel :(
pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo /usr/sbin/tcpdump -i 7
tcpdump: Can't open USB bus file /sys/kernel/debug/usbmon/1t: No such
file or directory
pi@rpi4:~/linuxcnc/configs/sheldon-lathe $ sudo ls /sys/kernel/debug
asoc cleancache devices_deferred f2fs hid
memblock pm_genpd regmap sleep_time vc-mem
bdi clear_warn_once dma_buf fault_around_bytes
ieee80211 mmc0 pm_qos regulator tracing vcsm-cma
block clk dri frontswap irq
mmc1 pwm sched_debug usb vc-smem
bluetooth device_component extfrag gpio
kprobes pinctrl ras sched_features vchiq
Thanks anyway, Reco.
Cheers, Gene Heskett
--
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Genes Web page <http://geneslinuxbox.net:6309/gene>
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