On Tuesday 2010-08-31 20:26, Nicola Padovano wrote: >Hi guys! i know the skb_transport_header to grab the tcp header of a >packet...so i can write: >struct tcphdr *tcp_header1 = (struct >tcphdr*)skb_transport_header(skb), where skb is a certain packet. > >now, studying some source code that i've found some days ago, i've seen this: > >struct tcphdr *tcp_header2 = (void*)ip_hdr(skb) + ip_hdrlen(skb); > >I immediately thought that the two lines were identical, but but I was >mistaken...in fact if i write this: > >printk(KERN_INFO "diff: %d\n",(int)((void*)tcp_header2 - (void*)tcp_header1)); > >i see, "diff: 20" > >so my question is: what's the difference between the two code lines? skb_transport_header is also explained in the PDF, especially when it can not be used. -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
