Hi all,

I'm adding a decoder for the gtp protocol. My query is :

1 ) So gtp_handle will do the dissection. It refers to the file packet_gtp.c .

Finds the hex value for example in the following statement :

#define      GTP_EXT_XXX      0x8f

 and then if its value in the header matches 0x8f, refers to the (val, decode_fun)  pair and then calls decode_fun to handle the decoding.

Now my question is : will the pointer tvb ( which is tvb_buff * tvb) be incremented automatically when it enters the function decode_fun ? Or we have to explicitly increment the pointer tvb in the decoder functin to account for the byte containing 0x8f value in the tvb?

 

 

My other questions are :

2) I'm trying to locate the file containing the definition for the function gtp_handle. But I'm not able to find it. Kindly can one please tell me where its definition is?

 

3) Before actually starting the decoding in our decode function what is the code that we have to write and what that is for?

 

regards,

Prashanth