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| author | Rick Jones <rick.jones2@hp.com> | 2014-11-06 10:37:54 -0800 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2014-11-07 15:45:50 -0500 |
| commit | 36cbb2452cbafca64dcdd3578047433787900cf0 (patch) | |
| tree | 3e50381574c3850fc2a6c76a14777daa821f85a0 /net/ipv4/udp.c | |
| parent | f46ad73ac6965f71d1a2ba217c4eb5b644e62949 (diff) | |
| download | lwn-36cbb2452cbafca64dcdd3578047433787900cf0.tar.gz lwn-36cbb2452cbafca64dcdd3578047433787900cf0.zip | |
udp: Increment UDP_MIB_IGNOREDMULTI for arriving unmatched multicasts
As NIC multicast filtering isn't perfect, and some platforms are
quite content to spew broadcasts, we should not trigger an event
for skb:kfree_skb when we do not have a match for such an incoming
datagram. We do though want to avoid sweeping the matter under the
rug entirely, so increment a suitable statistic.
This incorporates feedback from David L. Stevens, Karl Neiss and Eric
Dumazet.
V3 - use bool per David Miller
Signed-off-by: Rick Jones <rick.jones2@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 12 |
1 files changed, 9 insertions, 3 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index df19027f44f3..5d0fdca8e965 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1647,7 +1647,8 @@ static void udp_sk_rx_dst_set(struct sock *sk, struct dst_entry *dst) static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, struct udphdr *uh, __be32 saddr, __be32 daddr, - struct udp_table *udptable) + struct udp_table *udptable, + int proto) { struct sock *sk, *stack[256 / sizeof(struct sock *)]; struct hlist_nulls_node *node; @@ -1656,6 +1657,7 @@ static int __udp4_lib_mcast_deliver(struct net *net, struct sk_buff *skb, int dif = skb->dev->ifindex; unsigned int count = 0, offset = offsetof(typeof(*sk), sk_nulls_node); unsigned int hash2 = 0, hash2_any = 0, use_hash2 = (hslot->count > 10); + bool inner_flushed = false; if (use_hash2) { hash2_any = udp4_portaddr_hash(net, htonl(INADDR_ANY), hnum) & @@ -1674,6 +1676,7 @@ start_lookup: dif, hnum)) { if (unlikely(count == ARRAY_SIZE(stack))) { flush_stack(stack, count, skb, ~0); + inner_flushed = true; count = 0; } stack[count++] = sk; @@ -1695,7 +1698,10 @@ start_lookup: if (count) { flush_stack(stack, count, skb, count - 1); } else { - kfree_skb(skb); + if (!inner_flushed) + UDP_INC_STATS_BH(net, UDP_MIB_IGNOREDMULTI, + proto == IPPROTO_UDPLITE); + consume_skb(skb); } return 0; } @@ -1781,7 +1787,7 @@ int __udp4_lib_rcv(struct sk_buff *skb, struct udp_table *udptable, if (rt->rt_flags & (RTCF_BROADCAST|RTCF_MULTICAST)) return __udp4_lib_mcast_deliver(net, skb, uh, - saddr, daddr, udptable); + saddr, daddr, udptable, proto); sk = __udp4_lib_lookup_skb(skb, uh->source, uh->dest, udptable); if (sk != NULL) { |