ipv6: Stop sending in-kernel notifications for each nexthop

Both listeners - mlxsw and netdevsim - of IPv6 FIB notifications are now
ready to handle IPv6 multipath notifications.

Therefore, stop ignoring such notifications in both drivers and stop
sending notification for each added / deleted nexthop.

v2:
* Remove 'multipath_rt' from 'struct fib6_entry_notifier_info'
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>

drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c

@@ -6294,8 +6294,6 @@ static int mlxsw_sp_router_fib_event(struct notifier_block *nb,
 				NL_SET_ERR_MSG_MOD(info->extack, "IPv6 route with nexthop objects is not supported");
 				return notifier_from_errno(-EINVAL);
 			}
-			if (fen6_info->multipath_rt)
-				return NOTIFY_DONE;
 		}
 		break;
 	}

drivers/net/netdevsim/fib.c

@@ -190,13 +190,6 @@ static int nsim_fib_event_nb(struct notifier_block *nb, unsigned long event,
 
 	case FIB_EVENT_ENTRY_ADD:  /* fall through */
 	case FIB_EVENT_ENTRY_DEL:
-		if (info->family == AF_INET6) {
-			struct fib6_entry_notifier_info *fen6_info = ptr;
-
-			if (fen6_info->multipath_rt)
-				return NOTIFY_DONE;
-		}
-
 		err = nsim_fib_event(data, info,
 				     event == FIB_EVENT_ENTRY_ADD);
 		break;

include/net/ip6_fib.h

@@ -378,7 +378,6 @@ struct fib6_entry_notifier_info {
 	struct fib_notifier_info info; /* must be first */
 	struct fib6_info *rt;
 	unsigned int nsiblings;
-	bool multipath_rt;
 };
 
 /*

net/ipv6/ip6_fib.c

@@ -391,7 +391,6 @@ int call_fib6_multipath_entry_notifiers(struct net *net,
 		.info.extack = extack,
 		.rt = rt,
 		.nsiblings = nsiblings,
-		.multipath_rt = true,
 	};
 
 	rt->fib6_table->fib_seq++;
@@ -1140,11 +1139,13 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
 add:
 		nlflags |= NLM_F_CREATE;
 
-		err = call_fib6_entry_notifiers(info->nl_net,
-						FIB_EVENT_ENTRY_ADD,
-						rt, extack);
-		if (err)
-			return err;
+		if (!info->skip_notify_kernel) {
+			err = call_fib6_entry_notifiers(info->nl_net,
+							FIB_EVENT_ENTRY_ADD,
+							rt, extack);
+			if (err)
+				return err;
+		}
 
 		rcu_assign_pointer(rt->fib6_next, iter);
 		fib6_info_hold(rt);
@@ -1169,11 +1170,13 @@ static int fib6_add_rt2node(struct fib6_node *fn, struct fib6_info *rt,
 			return -ENOENT;
 		}
 
-		err = call_fib6_entry_notifiers(info->nl_net,
-						FIB_EVENT_ENTRY_REPLACE,
-						rt, extack);
-		if (err)
-			return err;
+		if (!info->skip_notify_kernel) {
+			err = call_fib6_entry_notifiers(info->nl_net,
+							FIB_EVENT_ENTRY_REPLACE,
+							rt, extack);
+			if (err)
+				return err;
+		}
 
 		fib6_info_hold(rt);
 		rcu_assign_pointer(rt->fib6_node, fn);
@@ -1856,9 +1859,11 @@ static void fib6_del_route(struct fib6_table *table, struct fib6_node *fn,
 
 	fib6_purge_rt(rt, fn, net);
 
-	call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
+	if (!info->skip_notify_kernel)
+		call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_DEL, rt, NULL);
 	if (!info->skip_notify)
 		inet6_rt_notify(RTM_DELROUTE, rt, info, 0);
+
 	fib6_info_release(rt);
 }