On Thu, Oct 12, 2017 at 12:30 PM, Willem de Bruijn <willemdebruijn.ker...@gmail.com> wrote: > On Thu, Oct 12, 2017 at 11:44 AM, Anton Ivanov > <anton.iva...@cambridgegreys.com> wrote: >> Found it. >> >> Two bugs canceling each other. >> The bind sequence in: psock_txring_vnet.c is wrong. >> >> It does the following addr.sll_protocol = htons(ETH_P_IP); >> before calling bind. >> >> If you set addr.sll_protocol to ETH_P_ALL where it should have been in the >> first place the test program blows up with -ENOBUFS > > There is no such requirement that the socket should bind to ETH_P_ALL. > >> I think what is happening is that this value is taken into account when >> looking at "what should I use to segment it with" in skb_mac_gso_segment >> which is invoked at the end of the verification chain which starts in >> packet_direct_xmit in af_packet.c > > packet_snd sets skb->protocol based on the protocol that the packet > socket is bound to. Binding to ETH_P_IP is the right choice here.
To avoid having to open multiple sockets for different protocols, sockaddr_ll can also be passed in the msg_name argument on each call.
