ipv6: Extend notifier info for multipath routes

Extend the IPv6 FIB notifier info with number of sibling routes being
notified.

This will later allow listeners to process one notification for a
multipath routes instead of N, where N is the number of nexthops.
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/ip6_fib.h

@@ -377,6 +377,8 @@ typedef struct rt6_info *(*pol_lookup_t)(struct net *,
 struct fib6_entry_notifier_info {
 	struct fib_notifier_info info; /* must be first */
 	struct fib6_info *rt;
+	unsigned int nsiblings;
+	bool multipath_rt;
 };
 
 /*
@@ -450,6 +452,11 @@ int call_fib6_entry_notifiers(struct net *net,
 			      enum fib_event_type event_type,
 			      struct fib6_info *rt,
 			      struct netlink_ext_ack *extack);
+int call_fib6_multipath_entry_notifiers(struct net *net,
+					enum fib_event_type event_type,
+					struct fib6_info *rt,
+					unsigned int nsiblings,
+					struct netlink_ext_ack *extack);
 void fib6_rt_update(struct net *net, struct fib6_info *rt,
 		    struct nl_info *info);
 void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,

net/ipv6/ip6_fib.c

@@ -381,6 +381,23 @@ int call_fib6_entry_notifiers(struct net *net,
 	return call_fib6_notifiers(net, event_type, &info.info);
 }
 
+int call_fib6_multipath_entry_notifiers(struct net *net,
+					enum fib_event_type event_type,
+					struct fib6_info *rt,
+					unsigned int nsiblings,
+					struct netlink_ext_ack *extack)
+{
+	struct fib6_entry_notifier_info info = {
+		.info.extack = extack,
+		.rt = rt,
+		.nsiblings = nsiblings,
+		.multipath_rt = true,
+	};
+
+	rt->fib6_table->fib_seq++;
+	return call_fib6_notifiers(net, event_type, &info.info);
+}
+
 struct fib6_dump_arg {
 	struct net *net;
 	struct notifier_block *nb;