ok, Jan! Perfect. But there is a last question: i've seen a source code that get a packet just received from the Net: so -if I understand correctly- it can't use skb_network_header (IP header) because when i get a packet just received from the net i should have only the mac_header set. isn't it? But, i've seen the usage of skb_network_header... On Wed, Sep 1, 2010 at 12:53 PM, Jan Engelhardt <jengelh@xxxxxxxxxx> wrote: > On Wednesday 2010-09-01 11:57, Nicola Padovano wrote: > >>"If a packet is handled by a bridge, that is, a component that does not >>deal with layer 3 or 4, there is no point in spending time to find the >>start of the layer 3/4 header." >> >>Ok, well: great. but in this case (bridge) also the skb_network_header >>function is senseless because we don't have to find layer3 header. >>isn't it? > > Correct. > >>in general: when i can use the skb_transport_header function? > > When a transport header pointer has been set. Which is when the > appropriate layer-X function has processed it. (After ip_rcv for > example) > On the output path, since it goes in the reverse direction, it will > always be set. > > -- Nicola Padovano e-mail: nicola.padovano@xxxxxxxxx web: http://npadovano.altervista.org -- 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
