ipv6: Call skb_get_hash_flowi6 to get skb->hash in ip6_make_flowlabel

We can't call skb_get_hash here since the packet is not complete to do
flow_dissector. Create hash based on flowi6 instead.

Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ipv6.h

@@ -708,12 +708,13 @@ static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 
 #if IS_ENABLED(CONFIG_IPV6)
 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
-					__be32 flowlabel, bool autolabel)
+					__be32 flowlabel, bool autolabel,
+					struct flowi6 *fl6)
 {
 	if (!flowlabel && (autolabel || net->ipv6.sysctl.auto_flowlabels)) {
 		u32 hash;
 
-		hash = skb_get_hash(skb);
+		hash = skb_get_hash_flowi6(skb, fl6);
 
 		/* Since this is being sent on the wire obfuscate hash a bit
 		 * to minimize possbility that any useful information to an

net/ipv6/ip6_gre.c

@@ -728,7 +728,7 @@ static netdev_tx_t ip6gre_xmit2(struct sk_buff *skb,
 	 */
 	ipv6h = ipv6_hdr(skb);
 	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
-		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
+		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false, fl6));
 	ipv6h->hop_limit = tunnel->parms.hop_limit;
 	ipv6h->nexthdr = proto;
 	ipv6h->saddr = fl6->saddr;
@@ -1182,7 +1182,8 @@ static int ip6gre_header(struct sk_buff *skb, struct net_device *dev,
 
 	ip6_flow_hdr(ipv6h, 0,
 		     ip6_make_flowlabel(dev_net(dev), skb,
-					t->fl.u.ip6.flowlabel, false));
+					t->fl.u.ip6.flowlabel, false,
+					&t->fl.u.ip6));
 	ipv6h->hop_limit = t->parms.hop_limit;
 	ipv6h->nexthdr = NEXTHDR_GRE;
 	ipv6h->saddr = t->parms.laddr;

net/ipv6/ip6_output.c

@@ -207,7 +207,7 @@ int ip6_xmit(struct sock *sk, struct sk_buff *skb, struct flowi6 *fl6,
 		hlimit = ip6_dst_hoplimit(dst);
 
 	ip6_flow_hdr(hdr, tclass, ip6_make_flowlabel(net, skb, fl6->flowlabel,
-						     np->autoflowlabel));
+						     np->autoflowlabel, fl6));
 
 	hdr->payload_len = htons(seg_len);
 	hdr->nexthdr = proto;
@@ -1649,7 +1649,7 @@ struct sk_buff *__ip6_make_skb(struct sock *sk,
 
 	ip6_flow_hdr(hdr, v6_cork->tclass,
 		     ip6_make_flowlabel(net, skb, fl6->flowlabel,
-					np->autoflowlabel));
+					np->autoflowlabel, fl6));
 	hdr->hop_limit = v6_cork->hop_limit;
 	hdr->nexthdr = proto;
 	hdr->saddr = fl6->saddr;

net/ipv6/ip6_tunnel.c

@@ -1095,7 +1095,7 @@ static int ip6_tnl_xmit2(struct sk_buff *skb,
 	skb_reset_network_header(skb);
 	ipv6h = ipv6_hdr(skb);
 	ip6_flow_hdr(ipv6h, INET_ECN_encapsulate(0, dsfield),
-		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false));
+		     ip6_make_flowlabel(net, skb, fl6->flowlabel, false, fl6));
 	ipv6h->hop_limit = t->parms.hop_limit;
 	ipv6h->nexthdr = proto;
 	ipv6h->saddr = fl6->saddr;