net: Align ip_multipath_l3_keys and ip6_multipath_l3_keys

Symmetry is good and allows easy comparison that ipv4 and ipv6 are
doing the same thing. To that end, change ip_multipath_l3_keys to
set addresses at the end after the icmp compares, and move the
initialization of ipv6 flow keys to rt6_multipath_hash.

Signed-off-by: David Ahern <dsahern@gmail.com>
Reviewed-by: Ido Schimmel <idosch@mellanox.com>
Reviewed-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/ipv4/route.c

@@ -1748,37 +1748,39 @@ static void ip_multipath_l3_keys(const struct sk_buff *skb,
 				 struct flow_keys *hash_keys)
 {
 	const struct iphdr *outer_iph = ip_hdr(skb);
+	const struct iphdr *key_iph = outer_iph;
 	const struct iphdr *inner_iph;
 	const struct icmphdr *icmph;
 	struct iphdr _inner_iph;
 	struct icmphdr _icmph;
 
-	hash_keys->addrs.v4addrs.src = outer_iph->saddr;
-	hash_keys->addrs.v4addrs.dst = outer_iph->daddr;
 	if (likely(outer_iph->protocol != IPPROTO_ICMP))
-		return;
+		goto out;
 
 	if (unlikely((outer_iph->frag_off & htons(IP_OFFSET)) != 0))
-		return;
+		goto out;
 
 	icmph = skb_header_pointer(skb, outer_iph->ihl * 4, sizeof(_icmph),
 				   &_icmph);
 	if (!icmph)
-		return;
+		goto out;
 
 	if (icmph->type != ICMP_DEST_UNREACH &&
 	    icmph->type != ICMP_REDIRECT &&
 	    icmph->type != ICMP_TIME_EXCEEDED &&
 	    icmph->type != ICMP_PARAMETERPROB)
-		return;
+		goto out;
 
 	inner_iph = skb_header_pointer(skb,
 				       outer_iph->ihl * 4 + sizeof(_icmph),
 				       sizeof(_inner_iph), &_inner_iph);
 	if (!inner_iph)
-		return;
-	hash_keys->addrs.v4addrs.src = inner_iph->saddr;
-	hash_keys->addrs.v4addrs.dst = inner_iph->daddr;
+		goto out;
+
+	key_iph = inner_iph;
+out:
+	hash_keys->addrs.v4addrs.src = key_iph->saddr;
+	hash_keys->addrs.v4addrs.dst = key_iph->daddr;
 }
 
 /* if skb is set it will be used and fl4 can be NULL */

net/ipv6/route.c

@@ -1815,8 +1815,6 @@ static void ip6_multipath_l3_keys(const struct sk_buff *skb,
 	key_iph = inner_iph;
 	_flkeys = NULL;
 out:
-	memset(keys, 0, sizeof(*keys));
-	keys->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 	if (_flkeys) {
 		keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
 		keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
@@ -1837,6 +1835,8 @@ u32 rt6_multipath_hash(const struct flowi6 *fl6, const struct sk_buff *skb,
 	struct flow_keys hash_keys;
 
 	if (skb) {
+		memset(&hash_keys, 0, sizeof(hash_keys));
+		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
 		ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
 		return flow_hash_from_keys(&hash_keys) >> 1;
 	}