From 23aebdacb05dab9efdf22b9e0413491cbd5f128f Mon Sep 17 00:00:00 2001 From: Jakub Sitnicki Date: Wed, 23 Aug 2017 09:58:29 +0200 Subject: ipv6: Compute multipath hash for ICMP errors from offending packet When forwarding or sending out an ICMPv6 error, look at the embedded packet that triggered the error and compute a flow hash over its headers. This let's us route the ICMP error together with the flow it belongs to when multipath (ECMP) routing is in use, which in turn makes Path MTU Discovery work in ECMP load-balanced or anycast setups (RFC 7690). Granted, end-hosts behind the ECMP router (aka servers) need to reflect the IPv6 Flow Label for PMTUD to work. The code is organized to be in parallel with ipv4 stack: ip_multipath_l3_keys -> ip6_multipath_l3_keys fib_multipath_hash -> rt6_multipath_hash Signed-off-by: Jakub Sitnicki Signed-off-by: David S. Miller --- net/ipv6/icmp.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/ipv6/icmp.c') diff --git a/net/ipv6/icmp.c b/net/ipv6/icmp.c index 4f82830fc068..dd7608cf1d72 100644 --- a/net/ipv6/icmp.c +++ b/net/ipv6/icmp.c @@ -519,6 +519,7 @@ static void icmp6_send(struct sk_buff *skb, u8 type, u8 code, __u32 info, fl6.fl6_icmp_type = type; fl6.fl6_icmp_code = code; fl6.flowi6_uid = sock_net_uid(net, NULL); + fl6.mp_hash = rt6_multipath_hash(&fl6, skb); security_skb_classify_flow(skb, flowi6_to_flowi(&fl6)); sk = icmpv6_xmit_lock(net); -- cgit 1.4.1