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

Mikhail Gusarov dottedmag at dottedmag.net
Sun Jul 21 16:14:33 EDT 2019


Hello Guy,

On 21 Jul 2019, at 20:28, Guy Harris wrote:

>> The link-level protocol is described in section 5 of
>> https://www.silabs.com/documents/login/user-guides/INS12350-Serial-API-Host-Appl.-Prg.-Guide.pdf
>
> So the packets would either be:
>
> 	an ACK frame, with the packet data being 1 byte of 0x06;
>
> 	a NAK frame, with the packet data being 1 byte of 0x15;
>
> 	a CAN frame, with the packet data being 1 byte of 0x18;
>
> 	a data frame, with the packet data beginning with 1 byte of 0x01, 
> followed by the other fields in Figure 5?

That's right. Also there might be some garbage frames at the beginning 
of capture
(basically, the contents of the current packet up to ACK/NAK/CAN/data).

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,
skipped and then another SOF might be encountered...

Best,
Mikhail.


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