From 79a131592dbb81a2dba208622a2ffbfc53f28bc0 Mon Sep 17 00:00:00 2001 From: Peter Nørlund Date: Wed, 30 Sep 2015 10:12:22 +0200 Subject: ipv4: ICMP packet inspection for multipath MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit ICMP packets are inspected to let them route together with the flow they belong to, minimizing the chance that a problematic path will affect flows on other paths, and so that anycast environments can work with ECMP. Signed-off-by: Peter Nørlund Signed-off-by: David S. Miller --- net/ipv4/icmp.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) (limited to 'net/ipv4/icmp.c') diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c index 6b96dee2800b..36e26977c908 100644 --- a/net/ipv4/icmp.c +++ b/net/ipv4/icmp.c @@ -440,6 +440,22 @@ out_unlock: icmp_xmit_unlock(sk); } +#ifdef CONFIG_IP_ROUTE_MULTIPATH + +/* Source and destination is swapped. See ip_multipath_icmp_hash */ +static int icmp_multipath_hash_skb(const struct sk_buff *skb) +{ + const struct iphdr *iph = ip_hdr(skb); + + return fib_multipath_hash(iph->daddr, iph->saddr); +} + +#else + +#define icmp_multipath_hash_skb(skb) (-1) + +#endif + static struct rtable *icmp_route_lookup(struct net *net, struct flowi4 *fl4, struct sk_buff *skb_in, @@ -464,7 +480,8 @@ static struct rtable *icmp_route_lookup(struct net *net, fl4->flowi4_oif = l3mdev_master_ifindex(skb_in->dev); security_skb_classify_flow(skb_in, flowi4_to_flowi(fl4)); - rt = __ip_route_output_key(net, fl4); + rt = __ip_route_output_key_hash(net, fl4, + icmp_multipath_hash_skb(skb_in)); if (IS_ERR(rt)) return rt; -- cgit v1.2.3