Validate the IE order for some of the cases. For other cases, as with
the Disassociation, Deauthentication and Action frame types in section
9.3 it's not even clear from the spec the fields are expected to be IEs
(in fact for Action frame we know they aren't). For the Shared Key
authentication type drop the union with the contents as they can be
easier parsed as an IE sequence. For SAE we are not expecting an IE
sequence apparently so this is where the union could come useful but
let's leave that until we want to support SAE.
Check the IE order for each frame type where we'd just do the body
minimum length check until now (and not always correctly). We do not
try to validate the contents of any IEs (may be doable for some) or the
minimum mandatory IEs presence. This is because which IEs are required
depend on the contents of other fields in the frame, on the
authentication state and STA config and even contents of a request frame
which we're validating the response to. Frame handlers have to do this
work anyway.
Declare the two missing frame subtype enum values for Action frames,
assume Action frames are valid. Once we have specific validation code
for any Action frames elsewhere, we can move it to mpdu_validate, but
right don't try to validate the frame body as there are many subtypes
and we don't use any of them except Neighbor Reports which are actually
really simple.
src/mpdu.c: In function ‘mpdu_validate’:
src/mpdu.c:180:9: error: ‘mmpdu’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
mmpdu = (const struct mmpdu_header *) mmpdu;
^
Refactor management frame structures to take into account optional
presence of some parts of the header:
* drop the single structure for management header and body since
the body offset is variable.
* add mmpdu_get_body to locate the start of frame body.
* drop the union of different management frame type bodies.
* prefix names specific to management frames with "mmpdu" instead
of "mpdu" including any enums based on 802.11-2012 section 8.4.
* move the FC field to the mmpdu_header structure.
What comes in is a frame, and let's set it to uint8_t pointer, which is
semantically better than unsigned char.
Also, returning the cast pointer instead of a boolean is easier to
use as there won't be any need to perform the cast ourselves afterward
