[tcpdump-workers] New link-type for Z-Wave serial interface

Guy Harris gharris at sonic.net
Sun Jul 21 17:07:27 EDT 2019


On Jul 21, 2019, at 1:27 PM, Guy Harris <gharris at sonic.net> wrote:
> 
> On Jul 21, 2019, at 1:14 PM, Mikhail Gusarov <dottedmag at dottedmag.net> wrote:
> 
>> Now that I think about it, in a very rare case it is possible to not be able to synchronize at all:
>> if a SOF byte is encountered inside the data frame, then the next byte will be interpreted as a length,
> 
> If by "SOF byte" you mean "byte with the value 0x01", then an SOF byte will be encountered inside every frame of type Response, so it seems pretty clear that a data-frame-reading algorithm of "read and accumulate bytes until you see an 0x01" won't work.

Or do you mean that if the receiver has already determined that it's out of sync (for example, due to losing bytes), and it waits for an 0x01 (or possibly an ACK/NAK/CAN), it might see a 0x01 that's part of frame data, and think that's the beginning of a frame?



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