ipv6: Enable auto flow labels by default

Initialize auto_flowlabels to one. This enables automatic flow labels,
individual socket may disable them using the IPV6_AUTOFLOWLABEL socket
option.
Signed-off-by: NTom Herbert <tom@herbertland.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Documentation/networking/ip-sysctl.txt

@@ -1228,7 +1228,7 @@ auto_flowlabels - INTEGER
 	   per socket basis using the IPV6_AUTOFLOWLABEL socket option
 	3: automatic flow labels are enabled and enforced, they cannot
 	   be disabled by the socket option
-	Default: 0
+	Default: 1
 
 flowlabel_state_ranges - BOOLEAN
 	Split the flow label number space into two ranges. 0-0x7FFFF is

include/net/ipv6.h

@@ -716,7 +716,7 @@ static inline void iph_to_flow_copy_v6addrs(struct flow_keys *flow,
 
 #define IP6_AUTO_FLOW_LABEL_MAX		IP6_AUTO_FLOW_LABEL_FORCED
 
-#define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OFF
+#define IP6_DEFAULT_AUTO_FLOW_LABELS	IP6_AUTO_FLOW_LABEL_OPTOUT
 
 static inline __be32 ip6_make_flowlabel(struct net *net, struct sk_buff *skb,
 					__be32 flowlabel, bool autolabel,