Hi ,

I want to include some RANAP ( asn.1 format) messages in my dissector.

I have seen the way H245 messages are included in MEGACO. On similar lines, I have written the following code:

dissect_xxx_reset(tvbuff_t *tvb,int offset ,proto_tree *xxx_tree,packet_info *pinfo)

{

guint8 *buf = ep_alloc(10240);

tvbuff_t *ranap_tvb;

int i = 0;

asn1_ctx_t actx;

offset = add_IE_indicator(tvb, offset, xxx_tree); /* To add IE Indicator */

offset = add_IE_length(tvb, offset, xxx_tree);    /* To add IE length    */

ranap_tvb = tvb_new_real_data(buf,i,i);

tvb_set_child_real_data_tvbuff(tvb,ranap_tvb);

add_new_data_source(pinfo, ranap_tvb, "RANAP OVER XXX");

asn1_ctx_init(&actx, ASN1_ENC_PER, TRUE, pinfo);

offset = dissect_ranap_Reset(tvb, offset, &actx, xxx_tree, hf_xxx_ranap_reset);

…………

………

}

But I am not getting any display of RANAP messages.

On the contrary, if I do not use the functions tvb_set_child_real_data_tvbuff,  add_new_data_source, I am getting partial display of the RANAP message.

I could not completely understand the way it is implemented inn MEGACO.

1. The purpose of the functions tvb_set_child_real_data_tvbuff and add_new_data_source.

2. The values to be passed to the function tvb_new_real_data. I have initialised with zero, but its not working out.

So can somebody help me on the above mentioned functions and how should I go about implementation.

Regards,

Tarani