If net.ipv6.icmp.ratelimit is zero we do not have to call inet_getpeer_v6() and inet_peer_xrlim_allow(). Both can be very expensive under DDOS. Signed-off-by: Eric Dumazet --- net/ipv6/icmp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 0f41ca6f3d83e86ce97ce5a30613f58f4dc22dad..813d2e9edb8bed7c1649e279cea9229806af4132 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -220,8 +220,12 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, int tmo = READ_ONCE(net->ipv6.sysctl.icmpv6_time); struct inet_peer *peer; - peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr); - res = inet_peer_xrlim_allow(peer, tmo); + if (!tmo) { + res = true; + } else { + peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr); + res = inet_peer_xrlim_allow(peer, tmo); + } } rcu_read_unlock(); if (!res) -- 2.53.0.310.g728cabbaf7-goog