Wireshark · Wireshark-dev: Re: [Wireshark-dev] was: Adding Files to Wireshark (new developer)

[Stephen Fisher <steve@xxxxxxxxxxxxxxxxxx>]

On Fri, Apr 01, 2011 at 02:36:50PM -0400, Bill Meier wrote:

> Take at look at the data struct passed to register_tap() (or whatever 
> it's called) when the tap is created by the dissector.
> 
> I'm not a 'tap' expert, but I think a ptr to that struct is passed to 
> the tap callback fcn called for each frame.

The tap_queue_packet() function takes three parameters:

void tap_queue_packet(int tap_id, packet_info *pinfo, const void 
*tap_specific_data)

The third value, tap_specific_data can be used to pass any data you 
would like from a dissector to the tap functions.

For an example, look at the dissect_http_message function in 
epan/dissectors/packet-http.c which passes the eo_info struct to the 
http_eo_tap (which is read by the tap code in gtk/export_object_http.c 
function eo_http_packet).