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 --- include/uapi/linux/if_packet.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/uapi/linux/if_packet.h') diff --git a/include/uapi/linux/if_packet.h b/include/uapi/linux/if_packet.h index c07caf7b40db..a8516b3594a4 100644 --- a/include/uapi/linux/if_packet.h +++ b/include/uapi/linux/if_packet.h @@ -70,6 +70,7 @@ struct sockaddr_ll { #define PACKET_FANOUT_EBPF 7 #define PACKET_FANOUT_FLAG_ROLLOVER 0x1000 #define PACKET_FANOUT_FLAG_UNIQUEID 0x2000 +#define PACKET_FANOUT_FLAG_IGNORE_OUTGOING 0x4000 #define PACKET_FANOUT_FLAG_DEFRAG 0x8000 struct tpacket_stats { -- cgit v1.2.1