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authorVincent Whitchurch <vincent.whitchurch@axis.com>2018-09-03 16:23:36 +0200
committerDavid S. Miller <davem@davemloft.net>2018-09-05 22:09:37 -0700
commitfa788d986a3aac5069378ed04697bd06f83d3488 (patch)
treee335abac12b88e196f4c7c9e1012a66e93f53830 /net/packet
parent05dcc71298643256948a2e17db7dbecc748719d2 (diff)
downloadlinux-stericsson-fa788d986a3aac5069378ed04697bd06f83d3488.tar.gz
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/packet')
-rw-r--r--net/packet/af_packet.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 75c92a87e7b2..f85f67b5c1f4 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3805,6 +3805,20 @@ packet_setsockopt(struct socket *sock, int level, int optname, char __user *optv
return fanout_set_data(po, optval, optlen);
}
+ case PACKET_IGNORE_OUTGOING:
+ {
+ int val;
+
+ if (optlen != sizeof(val))
+ return -EINVAL;
+ if (copy_from_user(&val, optval, sizeof(val)))
+ return -EFAULT;
+ if (val < 0 || val > 1)
+ return -EINVAL;
+
+ po->prot_hook.ignore_outgoing = !!val;
+ return 0;
+ }
case PACKET_TX_HAS_OFF:
{
unsigned int val;
@@ -3928,6 +3942,9 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
((u32)po->fanout->flags << 24)) :
0);
break;
+ case PACKET_IGNORE_OUTGOING:
+ val = po->prot_hook.ignore_outgoing;
+ break;
case PACKET_ROLLOVER_STATS:
if (!po->rollover)
return -EINVAL;