From: Eric Dumazet Date: Mon, 16 Feb 2026 14:28:30 +0000 (+0000) Subject: ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow() X-Git-Tag: v7.0-rc1~44^2~10^2~2 X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=0201eedb69b24a6be9b7c1716287a89c4dde2320;p=thirdparty%2Fkernel%2Flinux.git ipv6: icmp: remove obsolete code in icmpv6_xrlim_allow() Following part was needed before the blamed commit, because inet_getpeer_v6() second argument was the prefix. /* Give more bandwidth to wider prefixes. */ if (rt->rt6i_dst.plen < 128) tmo >>= ((128 - rt->rt6i_dst.plen)>>5); Now inet_getpeer_v6() retrieves hosts, we need to remove @tmo adjustement or wider prefixes likes /24 allow 8x more ICMP to be sent for a given ratelimit. As we had this issue for a while, this patch changes net.ipv6.icmp.ratelimit default value from 1000ms to 100ms to avoid potential regressions. Also add a READ_ONCE() when reading net->ipv6.sysctl.icmpv6_time. Fixes: fd0273d7939f ("ipv6: Remove external dependency on rt6i_dst and rt6i_src") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Cc: Martin KaFai Lau Link: https://patch.msgid.link/20260216142832.3834174-4-edumazet@google.com Signed-off-by: Jakub Kicinski --- diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst index 28c7e4f5ecf9..6921d8594b84 100644 --- a/Documentation/networking/ip-sysctl.rst +++ b/Documentation/networking/ip-sysctl.rst @@ -3234,12 +3234,13 @@ enhanced_dad - BOOLEAN =========== ratelimit - INTEGER - Limit the maximal rates for sending ICMPv6 messages. + Limit the maximal rates for sending ICMPv6 messages to a particular + peer. 0 to disable any limiting, - otherwise the minimal space between responses in milliseconds. + otherwise the space between responses in milliseconds. - Default: 1000 + Default: 100 ratemask - list of comma separated ranges For ICMPv6 message types matching the ranges in the ratemask, limit diff --git a/net/ipv6/af_inet6.c b/net/ipv6/af_inet6.c index 31ba677d0442..69be0a67a140 100644 --- a/net/ipv6/af_inet6.c +++ b/net/ipv6/af_inet6.c @@ -952,7 +952,7 @@ static int __net_init inet6_net_init(struct net *net) int err = 0; net->ipv6.sysctl.bindv6only = 0; - net->ipv6.sysctl.icmpv6_time = 1*HZ; + net->ipv6.sysctl.icmpv6_time = HZ / 10; net->ipv6.sysctl.icmpv6_echo_ignore_all = 0; net->ipv6.sysctl.icmpv6_echo_ignore_multicast = 0; net->ipv6.sysctl.icmpv6_echo_ignore_anycast = 0; diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 375ecd779fda..0f41ca6f3d83 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -217,14 +217,9 @@ static bool icmpv6_xrlim_allow(struct sock *sk, u8 type, } else if (dev && (dev->flags & IFF_LOOPBACK)) { res = true; } else { - struct rt6_info *rt = dst_rt6_info(dst); - int tmo = net->ipv6.sysctl.icmpv6_time; + int tmo = READ_ONCE(net->ipv6.sysctl.icmpv6_time); struct inet_peer *peer; - /* Give more bandwidth to wider prefixes. */ - if (rt->rt6i_dst.plen < 128) - tmo >>= ((128 - rt->rt6i_dst.plen)>>5); - peer = inet_getpeer_v6(net->ipv6.peers, &fl6->daddr); res = inet_peer_xrlim_allow(peer, tmo); }