The presence of the LENGTH field adds an additional offset which
breaks the related M_SERIALIZE in gsm_rlcmac.cpp. In that case,
the Desc in EGPRS_AckNack_t is being cast to EGPRS_AckNack_w_len_t
and then ((EGPRS_AckNack_w_len_t *)Desc)->Desc is filled with the
parsed data, which is a platform dependant number of bytes apart the
real Desc struct.
Remove LENGTH field from EGPRS_AckNack_w_len_t so that the Desc field
is the first field.
Note that this is not a real fix. The rlcmac wireshark dissector
still has the same declaration but doesn't seem to suffer from this
problem.
Sponsored-by: On-Waves ehf
Generic improvements to the csn.1 dissector include:
• Added a flag to the type descriptor structure so that any type can (potentially) flagged as xxx_OR_NULL. This was specifically needed for UINT_OR_NULL for the ms capabilities struct.
• Changed the CSN_SERIALIZE so that the length of the length field can be specified.
• For CSN_NEXT_EXIST removed the requirement that the next type be CSN_END, to allow truncation of multiple IEs.
• For CSN_LEFT_ALIGNED_VAR_BITMAP corrected the handling of bit_offset.
• Added a new type CSN_PADDING_BITS to make inspection of padding bits more convenient.
• Improved the CSN_RECURSIVE_TARRAY_1 to show the array index.
Improvements to the gsm_rlcmac dissector include:
• Rework the definition of EGPRS Ack/Nack Description so that the length IE (and absence thereof) is handled correctly.
• Added Padding Bits definitions to all PDUs
• Change the Multislot_capability_t and Content_t definitions to allow truncation at any IE
Jacob Erlbeck
Harald Welte