diff options
| author | Willem de Bruijn <willemb@google.com> | 2022-10-27 17:10:14 -0400 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-10-28 22:00:49 -0700 |
| commit | 58ba426388d9fe56aa638f555b01d6e63cada88c (patch) | |
| tree | 3709aa38f3e61c645912c7f0d765c9c04fb4e84a | |
| parent | 637639cbfebb747406b9a57befc0b347057a3a24 (diff) | |
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 <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221027211014.3581513-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | include/uapi/linux/if_packet.h | 1 | ||||
| -rw-r--r-- | net/packet/af_packet.c | 1 |
2 files changed, 2 insertions, 0 deletions
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 { 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; |