On Wed, Aug 07, 2013 at 10:47:13AM -0700, David Miller wrote: > From: Eric Dumazet <eric.dumazet@xxxxxxxxx> > Date: Wed, 07 Aug 2013 09:40:09 -0700 > > > On Wed, 2013-08-07 at 18:22 +0200, Johannes Berg wrote: > > > >> Maybe. I haven't tested it, but I'm thinking that skb->data doesn't > >> point to the start of the data frame in this case, since we now call > >> eth_type_trans() which pulls the ethernet header. So if the device just > >> transmits skb->len starting from skb->data, it'll be wrong, no? That > >> seems a basic assumption though. > > > > Yes, it seems calling eth_type_trans() is not right here, and even could > > crash. > > > > Sorry, for being vague, I am a bit busy this morning. > > Yes, this is absolutely the core problem, you absolute cannot > call eth_type_trans() on the output path, it pulls off the > ethernet header from the packet. That can't possibly work. > > I want a real fix submitted formally for this problem immediately, > or else I'm reverting all of these changes this afternoon. One could simply call skb_push(skb, ETH_HLEN) right after calling eth_type_trans(skb, dev) in order to undo the 'data' and 'len' adjustment. Not sure if this kind of hack is the right way to go here, or if the whole af_packet parses ethernet header discussion should be opened again instead. Best wishes, Phil -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
