Ethereal-dev: Re: [ethereal-dev] WCCP 1.0 Decoder

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 This list is no longer active.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: Guy Harris <gharris@xxxxxxxxxxxx>
Date: Sat, 11 Dec 1999 15:16:36 -0800
> +    	guint8 ip_offset;
> +	
> +	proto_tree_add_item_hidden(gre_tree, hf_gre_wccp, offset, sizeof(type), TRUE);
> +    	offset += sizeof(type);    
> +	
> +	ip_offset = pd[offset]; 
> +	if ((ip_offset & 0x45)) {
> +		/* we can assume that all wccp packets are streaming ip */
> +	} else {
> +		/* WCCP 1 and 2 both use the same type, but v2 has an extra 4 octet header */
> +		offset += sizeof(guint32);
> +	}

That should perhaps be done by

	if ((pd[offset] & 0xF0) == 0x40) {
		/* it's WCCPv1 */
	} else {
		/* it's presumably WCCPv2 */
	}

so that IP options don't cause it to misinterpret the packet as WCCP
encapsulation for v2.

Note also that "calc_len()" would have to be changed as well, to include
the extra 4 octets - or perhaps the "calc_len()" code should be pulled
up into "dissect_gre()" itself, above the first
"proto_tree_add_item_format()" call.