!3519 refactored the SDAP to use the QFI from the header rather
than pass it to the rx function and got rid of the initialization
of QFI to -1.
However, entity roles are stored into the drb2qfi table, and the
indexing implies that the QFI is known. While in TX it is not an
issue since packets are forwarded based on the QFI, in RX the QFI
can only be parsed from the heaedr, therefore if headers are
disabled (--enable_sdap) the QFI is not there and it is wrong to
access the header (`buf[0]`) and looking for it.
This commit adds `enable_sdap` to `nr_sdap_entity_t` and initialize
it in `nr_sdap_add_entity()` from `sdap->role`
(disabled when `NO_SDAP_HEADER`). In `nr_sdap_rx_entity()`, only
parse `buf[0]` for QFI and derive `sdap_ul_rx`/`sdap_dl_rx` when
`enable_sdap` is true; otherwise, keep `offset=0` and forward
payload unchanged.
Guido Casati
7274e7c434