Wireshark · Ethereal-dev: [Ethereal-dev] Buffers and pointers in a dissector

["Paul Smith" <pihebbr@xxxxxxxxxxx>]

I am attempting to write my first dissector for Ethereal. The most efficient way that I can work out to do this particular dissector isto define a structure that is the right shape for the elements of the protocol. Then simply assign a pointer of this type to the start of the buffer. Can I do this in Ethereal?

 

Example:

 

struct udp

{

    unsigned short source_port;

    unsigned short destination_port

    unsigned short length;

    unsigned short checksum;

}

 

struct udp_header *udp_hdr;

 

udp_hdr=(struct udp_header*)data_buffer

 

I cannot work out if I can do this (with tvb_get_ptr??). Everything I tried didn't work.

 

By using this method, if I want to read the UDP source port, I can simply access "udp_hdr->source_port".

 

For complex protocols, this saves me LOADS of effort using the tvb_get type access mechanisms.

 

Thanks in advance for any help/advice you can give