Ethereal-dev: Re: [Ethereal-dev] Creating a new Dissector

Note: This archive is from the project's previous web site, ethereal.com. This list is no longer active.

Date Index Thread Index Other Months All Mailing Lists
Date Prev Date Next Thread Prev Thread Next
From: Richard Sharpe <rsharpe@xxxxxxxxxx>
Date: Mon, 7 Oct 2002 13:06:54 +0930 (CST)
On Mon, 7 Oct 2002, pevee wrote:

> Hi,
> 
>    Here is a segment of code...I did used tvb_get_ntohl();
> 
> =============================================
> static int ac_user_ip = -1;
> 
> guint32         user_ip;        //user ip defined
> 
>  tvb_memcpy(tvb, (guint8 *)&iph, offset, sizeof(e_ip));
>         iph.ip_len = g_ntohs(iph.ip_len);
>         iph.ip_id  = g_ntohs(iph.ip_id);
>         iph.ip_off = g_ntohs(iph.ip_off);
>         iph.ip_sum = g_ntohs(iph.ip_sum);

Hmmm, are you replacing the IP layer, or running atop the IP layer?
 
>  //retrieve the User IP Address from the packet
>         user_ip = tvb_get_ntohl(tvb, offset);
>         proto_tree_add_ipv4 (ac_tree, ac_user_ip, tvb, offset + 4, -4,
> user_ip);

I suspect that ntohl and add_ipv4 are fighting with each other! Change the 
ntohl to one that does not do byte swapping and see what happens.

Anyway, why aren't you using proto_tree_add_item(...) and specifying an 
hf_xyz that refers to an FT_IPv4 item?

Regards
-----
Richard Sharpe, rsharpe@xxxxxxxxxx, rsharpe@xxxxxxxxx, 
sharpe@xxxxxxxxxxxx, http://www.richardsharpe.com