Bug#606338: ax25ipd transmission bug
Am Donnerstag, den 09. Dezember 2010 um 01:47:01 Uhr, schrieb John Goerzen <jgoerzen@complete.org> in <[🔎] 4D002705.2020507@complete.org>:
> On 12/08/2010 06:35 PM, Thomas Osterried wrote:
> > Which kernel version do you use?
>
> 2.6.32
>
> > If your way is
> > kernel-ax25 -> kissattach -> pty -> ax25ipd -> inet
> > then kiss packets from kernel-ax25 -> pty never have the kiss byte != \0,
> > except kiss param commands (i.e. setting txdeleay).
>
> I'm not sure if that's exactly it or not.
>
> I wrote this script:
>
> #!/bin/bash
>
> tmpfile="/tmp/$$.startipd.pts"
>
> kissnetd -p2 > "$tmpfile" &
>
> sleep 2
>
> attachthem () {
> read PTS1 PTS2
> echo "Starting ipd on $PTS1 and $PTS2"
> kissattach -l $PTS1 ipct 44.254.254.20
> sleep 1
> sed -i "s,device /dev/.*$,device $PTS2," /etc/ax25/ax25ipd.conf
> ax25ipd
> }
>
> tail -n 1 $tmpfile | attachthem
> rm $tmpfile
>
> Is this not the proper way to go?
Yes. It's the way I described.
> > "if ((*iframe& 0xf) == 0)"
> > is not the correct way. Because:
> > 1. it will discard all kiss frames with kiss byte == 0 (!!!) - these are all ax25 packets. This will break every system except yours.
>
> I think you have your logic reversed.
Ooops. Yes, you're right.
> If it passes this test, it is
> processed. ((0 & 0xf) == 0) is true, after all. But Ralf probably
> ought to chime in here.
Yep. Sorry for the confusion. It was me :-S
> > Could you send us a dump what's really coming from the pty?
>
> I would love to, but I can't seem to reproduce the problem any more. I
> tried to reproduce it when I made it log the value of the bytes it was
> rejecting, but that didn't work. I can try to recreate my exact steps
> here and see if I can make it happen again. I am unsure why it changed.
> Does kissnetd or kissattach ever set the port bits?
No. They only tell the kernel to make a device and send data to the given serial port.
Every data frame the kernel leaves has the kiss byte set to 0, regardless how many ports you have attached.
73,
- Thomas dl9sau
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