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| author | Vincent Whitchurch <vincent.whitchurch@axis.com> | 2018-09-03 16:23:36 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-09-06 07:09:37 +0200 |
| commit | fa788d986a3aac5069378ed04697bd06f83d3488 (patch) | |
| tree | e335abac12b88e196f4c7c9e1012a66e93f53830 /net/netlink | |
| parent | net: lan743x_ptp: make function lan743x_ptp_set_sync_ts_insert() static (diff) | |
| download | linux-fa788d986a3aac5069378ed04697bd06f83d3488.tar.xz linux-fa788d986a3aac5069378ed04697bd06f83d3488.zip | |
packet: add sockopt to ignore outgoing packets
Currently, the only way to ignore outgoing packets on a packet socket is
via the BPF filter. With MSG_ZEROCOPY, packets that are looped into
AF_PACKET are copied in dev_queue_xmit_nit(), and this copy happens even
if the filter run from packet_rcv() would reject them. So the presence
of a packet socket on the interface takes away the benefits of
MSG_ZEROCOPY, even if the packet socket is not interested in outgoing
packets. (Even when MSG_ZEROCOPY is not used, the skb is unnecessarily
cloned, but the cost for that is much lower.)
Add a socket option to allow AF_PACKET sockets to ignore outgoing
packets to solve this. Note that the *BSDs already have something
similar: BIOCSSEESENT/BIOCSDIRECTION and BIOCSDIRFILT.
The first intended user is lldpd.
Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/netlink')
0 files changed, 0 insertions, 0 deletions