Hi Sylvain,

On Mon, Apr 18, 2011 at 02:19:18PM +0200, Sylvain Munaut wrote:

To add support for traffic extraction, it's necessary to introduce some nothing of "state" in the MAC layer (since the DL_USAGE must be 'remembered' to know how to interpret further data) ...

Any suggestion how to achieve that as cleanly as possible ?

Having a global doesn't sound that nice, but passing a struct around either. Maybe introduce a pointer to a 'tetra_state' in the primitive struct ?

I have been thinking about the same issue while working on the LLC reassembly, which obviously also needs state.

I guess in the end we will have something like a global 'tetra_carrier_state' struct, which then has sub-structs for the logical channels that we see.

And as I've now extended the primitive to use a msgb for storing the actual unpacked type-1 bits, I guess we could simply use something out of msgb->cb to point to the 'lchan' (in OpenBSC terminology).

Cheers, Harald