libmsc/gsm_04_08.c: refactor CM Service Request parsing
In gsm48_rx_mm_serv_req() we need to make sure that a given message
buffer is large enough to contain both 'gsm48_hdr' and
'gsm48_service_request' structures.
Comparing msg->data_len with size of pointer if wrong because:
- we actually need to compare with size of struct(s),
- we need msgb_l3len(), not length of the whole buffer.
Moreover, since we have to use the pointer arithmetics in order
to keep backwards compatibility with Phase1 phones, we also
need to check the length of both Classmark2 and MI IEs.
Change-Id: I6e7454d7a6f63fd5a0e12fb90d8c58688da0951e
1 file changed