Wireshark · Wireshark-dev: [Wireshark-dev] Proposed change to packet-tcp (tcp_dissect_pdus)

[Peter Johansson <Peter.xc.Johansson@xxxxxxxxxxxx>]

Hi!

I have come a across a really old protocol on top of TCP that I want to 
be able to decode using wireshark. Unfortunately the protocol's header 
is "polymorphic" and mean different things depending on from which 
source port the message is being sent. Hence the length of the PDU 
cannot be computed looking at the protocol header alone.
To make it easier to implement desegmentation of this protocol on top of 
TCP I would like to use the tcp_dissect_pdus(...) function in 
packet-tcp, however the with the information supplied in the callback to 
packet-my_own_decoder_with_some_obscude_header I cannot determine the 
PDU length. To do this properly I would require the packet_info 
structure also being passed along in the call from packet-tcp's 
tcp_dissect_pdus.
Would you approve of changing the interface to the function pointer 
"guint (*get_pdu_len)(tvbuff_t *, int)" into "guint 
(*get_pdu_len)(tvbuff_t *, int, packet_info*)" instead?

Please let me know and I will get on with the changes, supplying a list 
of patches asap. Taking the current set of dissectors into account, I 
would have to make changes to 66 dissectors in the current version.

/ Regards, Peter