Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S938779AbcJXJ3X (ORCPT ); Mon, 24 Oct 2016 05:29:23 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:35772 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757230AbcJXJ3I (ORCPT ); Mon, 24 Oct 2016 05:29:08 -0400 From: Jakub Sitnicki To: netdev@vger.kernel.org Cc: linux-kernel@vger.kernel.org, "David S. Miller" , Alexey Kuznetsov , James Morris , Hideaki YOSHIFUJI , Patrick McHardy Subject: [PATCH net-next 5/5] ipv6: Compute multipath hash for forwarded ICMP errors from offending packet Date: Mon, 24 Oct 2016 11:28:52 +0200 Message-Id: <1477301332-23954-6-git-send-email-jkbs@redhat.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1477301332-23954-1-git-send-email-jkbs@redhat.com> References: <1477301332-23954-1-git-send-email-jkbs@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1799 Lines: 56 Same as for the transmit path, let's do our best to ensure that received ICMP errors that may be subject to forwarding will be routed the same path as flow that triggered the error, if it was going in the opposite direction. Signed-off-by: Jakub Sitnicki --- net/ipv6/route.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+) diff --git a/net/ipv6/route.c b/net/ipv6/route.c index 1184c2b..c0f38ea 100644 --- a/net/ipv6/route.c +++ b/net/ipv6/route.c @@ -1150,6 +1150,30 @@ struct dst_entry *ip6_route_input_lookup(struct net *net, } EXPORT_SYMBOL_GPL(ip6_route_input_lookup); +static u32 ip6_multipath_icmp_hash(const struct sk_buff *skb) +{ + const struct icmp6hdr *icmph = icmp6_hdr(skb); + const struct ipv6hdr *inner_iph; + struct ipv6hdr _inner_iph; + + if (icmph->icmp6_type != ICMPV6_DEST_UNREACH && + icmph->icmp6_type != ICMPV6_PKT_TOOBIG && + icmph->icmp6_type != ICMPV6_TIME_EXCEED && + icmph->icmp6_type != ICMPV6_PARAMPROB) + goto standard_hash; + + inner_iph = skb_header_pointer( + skb, skb_transport_offset(skb) + sizeof(*icmph), + sizeof(_inner_iph), &_inner_iph); + if (!inner_iph) + goto standard_hash; + + return icmpv6_multipath_hash(inner_iph); + +standard_hash: + return 0; /* compute it later, if needed */ +} + void ip6_route_input(struct sk_buff *skb) { const struct ipv6hdr *iph = ipv6_hdr(skb); @@ -1168,6 +1192,8 @@ void ip6_route_input(struct sk_buff *skb) tun_info = skb_tunnel_info(skb); if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX)) fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id; + if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6)) + fl6.mp_hash = ip6_multipath_icmp_hash(skb); skb_dst_drop(skb); skb_dst_set(skb, ip6_route_input_lookup(net, skb->dev, &fl6, flags)); } -- 2.7.4