From 58ba426388d9fe56aa638f555b01d6e63cada88c Mon Sep 17 00:00:00 2001 From: Willem de Bruijn Date: Thu, 27 Oct 2022 17:10:14 -0400 Subject: net/packet: add PACKET_FANOUT_FLAG_IGNORE_OUTGOING Extend packet socket option PACKET_IGNORE_OUTGOING to fanout groups. The socket option sets ptype.ignore_outgoing, which makes dev_queue_xmit_nit skip the socket. When the socket joins a fanout group, the option is not reflected in the struct ptype of the group. dev_queue_xmit_nit only tests the fanout ptype, so the flag is ignored once a socket joins a fanout group. Inheriting the option from a socket would change established behavior. Different sockets in the group can set different flags, and can also change them at runtime. Testing in packet_rcv_fanout defeats the purpose of the original patch, which is to avoid skb_clone in dev_queue_xmit_nit (esp. for MSG_ZEROCOPY packets). Instead, introduce a new fanout group flag with the same behavior. Tested with https://github.com/wdebruij/kerneltools/blob/master/tests/test_psock_fanout_ignore_outgoing.c Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet Link: https://lore.kernel.org/r/20221027211014.3581513-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski --- net/packet/af_packet.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/packet') diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 8c5b3da0c29f..44f20cf8a0c0 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -1777,6 +1777,7 @@ static int fanout_add(struct sock *sk, struct fanout_args *args) match->prot_hook.af_packet_net = read_pnet(&match->net); match->prot_hook.id_match = match_fanout_group; match->max_num_members = args->max_num_members; + match->prot_hook.ignore_outgoing = type_flags & PACKET_FANOUT_FLAG_IGNORE_OUTGOING; list_add(&match->list, &fanout_list); } err = -EINVAL; -- cgit v1.2.3