On Mon, 03 Jan 2011 09:22:14 -0800 (PST) David Miller <davem@xxxxxxxxxxxxx> wrote: > From: Changli Gao <xiaosuo@xxxxxxxxx> > Date: Mon, 3 Jan 2011 18:44:59 +0800 > > > On Sat, Jan 1, 2011 at 3:10 AM, David Miller <davem@xxxxxxxxxxxxx> wrote: > >> From: Changli Gao <xiaosuo@xxxxxxxxx> > >> Date: Sat, 25 Dec 2010 21:41:30 +0800 > >> > >>> Since nf_bridge_maybe_copy_header() may change the length of skb, > >>> we should check the length of skb after it to handle the ppoe skbs. > >>> > >>> Signed-off-by: Changli Gao <xiaosuo@xxxxxxxxx> > >> > >> This is really strange. > >> > >> packet_length() subtracts VLAN_HLEN from the value it returns, so the > >> correct fix seems to be to make this function handle the PPPOE case > >> too. > >> > > > > It is correct. The actual MTU of 802.1q frame is 4 bytes larger. For > > example, the MTU of ethernet is normally 1500, however the actual MTU > > of the 802.1Q is 1504. > > Yes, I understand this, but I don't see why packet_length() cannot > simply account for PPPOE's encapsulation overhead just as it does for > VLAN's special MTU considerations. Because PPPOE happens afterwards and is not part the calculation. The check should be moved until after skb has reached final form. -- _______________________________________________ Bridge mailing list Bridge@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/bridge
