From 19469a873bafd4e65daef3597db2bd724c1b03c9 Mon Sep 17 00:00:00 2001 From: Tom Herbert Date: Tue, 1 Jul 2014 21:33:01 -0700 Subject: [PATCH] flow_dissector: Use IPv6 flow label in flow_dissector This patch implements the receive side to support RFC 6438 which is to use the flow label as an ECMP hash. If an IPv6 flow label is set in a packet we can use this as input for computing an L4-hash. There should be no need to parse any transport headers in this case. Signed-off-by: Tom Herbert Signed-off-by: David S. Miller --- net/core/flow_dissector.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/net/core/flow_dissector.c b/net/core/flow_dissector.c index 62d1cb624f53..c5f3912dad4c 100644 --- a/net/core/flow_dissector.c +++ b/net/core/flow_dissector.c @@ -80,6 +80,8 @@ ip: case htons(ETH_P_IPV6): { const struct ipv6hdr *iph; struct ipv6hdr _iph; + __be32 flow_label; + ipv6: iph = skb_header_pointer(skb, nhoff, sizeof(_iph), &_iph); if (!iph) @@ -89,6 +91,21 @@ ipv6: flow->src = (__force __be32)ipv6_addr_hash(&iph->saddr); flow->dst = (__force __be32)ipv6_addr_hash(&iph->daddr); nhoff += sizeof(struct ipv6hdr); + + flow_label = ip6_flowlabel(iph); + if (flow_label) { + /* Awesome, IPv6 packet has a flow label so we can + * use that to represent the ports without any + * further dissection. + */ + flow->n_proto = proto; + flow->ip_proto = ip_proto; + flow->ports = flow_label; + flow->thoff = (u16)nhoff; + + return true; + } + break; } case htons(ETH_P_8021AD): -- 2.20.1