ipv6: split duplicate address detection and router solicitation timer

This patch splits the timers for duplicate address detection and router
solicitations apart. The router solicitations timer goes into inet6_dev
and the dad timer stays in inet6_ifaddr.

The reason behind this patch is to reduce the number of unneeded router
solicitations send out by the host if additional link-local addresses
are created. Currently we send out RS for every link-local address on
an interface.

If the RS timer fires we pick a source address with ipv6_get_lladdr. This
change could hurt people adding additional link-local addresses and
specifying these addresses in the radvd clients section because we
no longer guarantee that we use every ll address as source address in
router solicitations.

Cc: Flavio Leitner <fleitner@redhat.com>
Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Cc: David Stevens <dlstevens@us.ibm.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Reviewed-by: Flavio Leitner <fbl@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/if_inet6.h b/include/net/if_inet6.h
index e07feb4..e4c5a2d 100644
--- a/include/net/if_inet6.h
+++ b/include/net/if_inet6.h
@@ -50,7 +50,7 @@
 
 	int			state;
 
-	__u8			probes;
+	__u8			dad_probes;
 	__u8			flags;
 
 	__u16			scope;
@@ -58,7 +58,7 @@
 	unsigned long		cstamp;	/* created timestamp */
 	unsigned long		tstamp; /* updated timestamp */
 
-	struct timer_list	timer;
+	struct timer_list	dad_timer;
 
 	struct inet6_dev	*idev;
 	struct rt6_info		*rt;
@@ -195,6 +195,10 @@
 	struct neigh_parms	*nd_parms;
 	struct ipv6_devconf	cnf;
 	struct ipv6_devstat	stats;
+
+	struct timer_list	rs_timer;
+	__u8			rs_probes;
+
 	unsigned long		tstamp; /* ipv6InterfaceTable update timestamp */
 	struct rcu_head		rcu;
 };