Merge branch 'ipv6-Move-exceptions-to-fib6_nh-and-make-it-optional-in-a-fib6_info'

David Ahern says:

====================
ipv6: Move exceptions to fib6_nh and make it optional in a fib6_info

Patches 1 and 4 move pcpu and exception caches from fib6_info to fib6_nh.
With respect to the current FIB entries this is only a movement from one
struct to another contained within the first.

Patch 2 refactors the core logic of fib6_drop_pcpu_from into a helper
that is invoked per fib6_nh.

Patch 3 refactors exception handling in a similar way - creating a bunch
of helpers that can be invoked per fib6_nh with the goal of making patch
4 easier to review as well as creating the code needed for nexthop
objects.

Patch 5 makes a fib6_nh at the end of a fib6_info an array similar to
IPv4 and its fib_info. For the current fib entry model, all fib6_info
will have a fib6_nh allocated for it.

Patch 6 refactors ip6_route_del moving the code for deleting an
exception entry into a new function.

Patch 7 adds tests for redirect route exceptions. The new test was
written against 5.1 (before any of the nexthop refactoring). It and the
pmtu.sh selftest exercise the exception code paths - from creating
exceptions to cleaning them up on device delete. All tests pass without
any rcu locking or memleak warnings.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

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

@@ -2886,7 +2886,7 @@ mlxsw_sp_nexthop6_group_cmp(const struct mlxsw_sp_nexthop_group *nh_grp,
 		return false;
 
 	list_for_each_entry(mlxsw_sp_rt6, &fib6_entry->rt6_list, list) {
-		struct fib6_nh *fib6_nh = &mlxsw_sp_rt6->rt->fib6_nh;
+		struct fib6_nh *fib6_nh = mlxsw_sp_rt6->rt->fib6_nh;
 		struct in6_addr *gw;
 		int ifindex, weight;
 
@@ -2958,7 +2958,7 @@ mlxsw_sp_nexthop6_group_hash(struct mlxsw_sp_fib6_entry *fib6_entry, u32 seed)
 	struct net_device *dev;
 
 	list_for_each_entry(mlxsw_sp_rt6, &fib6_entry->rt6_list, list) {
-		dev = mlxsw_sp_rt6->rt->fib6_nh.fib_nh_dev;
+		dev = mlxsw_sp_rt6->rt->fib6_nh->fib_nh_dev;
 		val ^= dev->ifindex;
 	}
 
@@ -3960,9 +3960,9 @@ mlxsw_sp_rt6_nexthop(struct mlxsw_sp_nexthop_group *nh_grp,
 		struct mlxsw_sp_nexthop *nh = &nh_grp->nexthops[i];
 		struct fib6_info *rt = mlxsw_sp_rt6->rt;
 
-		if (nh->rif && nh->rif->dev == rt->fib6_nh.fib_nh_dev &&
+		if (nh->rif && nh->rif->dev == rt->fib6_nh->fib_nh_dev &&
 		    ipv6_addr_equal((const struct in6_addr *) &nh->gw_addr,
-				    &rt->fib6_nh.fib_nh_gw6))
+				    &rt->fib6_nh->fib_nh_gw6))
 			return nh;
 		continue;
 	}
@@ -4022,13 +4022,13 @@ mlxsw_sp_fib6_entry_offload_set(struct mlxsw_sp_fib_entry *fib_entry)
 	if (fib_entry->type == MLXSW_SP_FIB_ENTRY_TYPE_LOCAL ||
 	    fib_entry->type == MLXSW_SP_FIB_ENTRY_TYPE_BLACKHOLE) {
 		list_first_entry(&fib6_entry->rt6_list, struct mlxsw_sp_rt6,
-				 list)->rt->fib6_nh.fib_nh_flags |= RTNH_F_OFFLOAD;
+				 list)->rt->fib6_nh->fib_nh_flags |= RTNH_F_OFFLOAD;
 		return;
 	}
 
 	list_for_each_entry(mlxsw_sp_rt6, &fib6_entry->rt6_list, list) {
 		struct mlxsw_sp_nexthop_group *nh_grp = fib_entry->nh_group;
-		struct fib6_nh *fib6_nh = &mlxsw_sp_rt6->rt->fib6_nh;
+		struct fib6_nh *fib6_nh = mlxsw_sp_rt6->rt->fib6_nh;
 		struct mlxsw_sp_nexthop *nh;
 
 		nh = mlxsw_sp_rt6_nexthop(nh_grp, mlxsw_sp_rt6);
@@ -4050,7 +4050,7 @@ mlxsw_sp_fib6_entry_offload_unset(struct mlxsw_sp_fib_entry *fib_entry)
 	list_for_each_entry(mlxsw_sp_rt6, &fib6_entry->rt6_list, list) {
 		struct fib6_info *rt = mlxsw_sp_rt6->rt;
 
-		rt->fib6_nh.fib_nh_flags &= ~RTNH_F_OFFLOAD;
+		rt->fib6_nh->fib_nh_flags &= ~RTNH_F_OFFLOAD;
 	}
 }
 
@@ -4928,7 +4928,8 @@ static void mlxsw_sp_rt6_destroy(struct mlxsw_sp_rt6 *mlxsw_sp_rt6)
 static bool mlxsw_sp_fib6_rt_can_mp(const struct fib6_info *rt)
 {
 	/* RTF_CACHE routes are ignored */
-	return !(rt->fib6_flags & RTF_ADDRCONF) && rt->fib6_nh.fib_nh_gw_family;
+	return !(rt->fib6_flags & RTF_ADDRCONF) &&
+		rt->fib6_nh->fib_nh_gw_family;
 }
 
 static struct fib6_info *
@@ -4987,8 +4988,8 @@ static bool mlxsw_sp_nexthop6_ipip_type(const struct mlxsw_sp *mlxsw_sp,
 					const struct fib6_info *rt,
 					enum mlxsw_sp_ipip_type *ret)
 {
-	return rt->fib6_nh.fib_nh_dev &&
-	       mlxsw_sp_netdev_ipip_type(mlxsw_sp, rt->fib6_nh.fib_nh_dev, ret);
+	return rt->fib6_nh->fib_nh_dev &&
+	       mlxsw_sp_netdev_ipip_type(mlxsw_sp, rt->fib6_nh->fib_nh_dev, ret);
 }
 
 static int mlxsw_sp_nexthop6_type_init(struct mlxsw_sp *mlxsw_sp,
@@ -4998,7 +4999,7 @@ static int mlxsw_sp_nexthop6_type_init(struct mlxsw_sp *mlxsw_sp,
 {
 	const struct mlxsw_sp_ipip_ops *ipip_ops;
 	struct mlxsw_sp_ipip_entry *ipip_entry;
-	struct net_device *dev = rt->fib6_nh.fib_nh_dev;
+	struct net_device *dev = rt->fib6_nh->fib_nh_dev;
 	struct mlxsw_sp_rif *rif;
 	int err;
 
@@ -5041,11 +5042,11 @@ static int mlxsw_sp_nexthop6_init(struct mlxsw_sp *mlxsw_sp,
 				  struct mlxsw_sp_nexthop *nh,
 				  const struct fib6_info *rt)
 {
-	struct net_device *dev = rt->fib6_nh.fib_nh_dev;
+	struct net_device *dev = rt->fib6_nh->fib_nh_dev;
 
 	nh->nh_grp = nh_grp;
-	nh->nh_weight = rt->fib6_nh.fib_nh_weight;
-	memcpy(&nh->gw_addr, &rt->fib6_nh.fib_nh_gw6, sizeof(nh->gw_addr));
+	nh->nh_weight = rt->fib6_nh->fib_nh_weight;
+	memcpy(&nh->gw_addr, &rt->fib6_nh->fib_nh_gw6, sizeof(nh->gw_addr));
 	mlxsw_sp_nexthop_counter_alloc(mlxsw_sp, nh);
 
 	list_add_tail(&nh->router_list_node, &mlxsw_sp->router->nexthop_list);
@@ -5068,7 +5069,7 @@ static void mlxsw_sp_nexthop6_fini(struct mlxsw_sp *mlxsw_sp,
 static bool mlxsw_sp_rt6_is_gateway(const struct mlxsw_sp *mlxsw_sp,
 				    const struct fib6_info *rt)
 {
-	return rt->fib6_nh.fib_nh_gw_family ||
+	return rt->fib6_nh->fib_nh_gw_family ||
 	       mlxsw_sp_nexthop6_ipip_type(mlxsw_sp, rt, NULL);
 }
 

include/net/ip6_fib.h

@@ -131,6 +131,9 @@ struct fib6_nh {
 #ifdef CONFIG_IPV6_ROUTER_PREF
 	unsigned long		last_probe;
 #endif
+
+	struct rt6_info * __percpu *rt6i_pcpu;
+	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
 };
 
 struct fib6_info {
@@ -156,22 +159,18 @@ struct fib6_info {
 	struct rt6key			fib6_src;
 	struct rt6key			fib6_prefsrc;
 
-	struct rt6_info * __percpu	*rt6i_pcpu;
-	struct rt6_exception_bucket __rcu *rt6i_exception_bucket;
-
 	u32				fib6_metric;
 	u8				fib6_protocol;
 	u8				fib6_type;
-	u8				exception_bucket_flushed:1,
-					should_flush:1,
+	u8				should_flush:1,
 					dst_nocount:1,
 					dst_nopolicy:1,
 					dst_host:1,
 					fib6_destroying:1,
-					unused:2;
+					unused:3;
 
-	struct fib6_nh			fib6_nh;
 	struct rcu_head			rcu;
+	struct fib6_nh			fib6_nh[0];
 };
 
 struct rt6_info {
@@ -281,7 +280,7 @@ static inline void ip6_rt_put(struct rt6_info *rt)
 	dst_release(&rt->dst);
 }
 
-struct fib6_info *fib6_info_alloc(gfp_t gfp_flags);
+struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh);
 void fib6_info_destroy_rcu(struct rcu_head *head);
 
 static inline void fib6_info_hold(struct fib6_info *f6i)
@@ -444,7 +443,7 @@ void rt6_get_prefsrc(const struct rt6_info *rt, struct in6_addr *addr)
 
 static inline struct net_device *fib6_info_nh_dev(const struct fib6_info *f6i)
 {
-	return f6i->fib6_nh.fib_nh_dev;
+	return f6i->fib6_nh->fib_nh_dev;
 }
 
 int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,

include/net/ip6_route.h

@@ -70,7 +70,7 @@ static inline bool rt6_qualify_for_ecmp(const struct fib6_info *f6i)
 {
 	/* the RTF_ADDRCONF flag filters out RA's */
 	return !(f6i->fib6_flags & RTF_ADDRCONF) &&
-		f6i->fib6_nh.fib_nh_gw_family;
+		f6i->fib6_nh->fib_nh_gw_family;
 }
 
 void ip6_route_input(struct sk_buff *skb);
@@ -275,7 +275,7 @@ static inline struct in6_addr *rt6_nexthop(struct rt6_info *rt,
 
 static inline bool rt6_duplicate_nexthop(struct fib6_info *a, struct fib6_info *b)
 {
-	struct fib6_nh *nha = &a->fib6_nh, *nhb = &b->fib6_nh;
+	struct fib6_nh *nha = a->fib6_nh, *nhb = b->fib6_nh;
 
 	return nha->fib_nh_dev == nhb->fib_nh_dev &&
 	       ipv6_addr_equal(&nha->fib_nh_gw6, &nhb->fib_nh_gw6) &&

net/ipv6/addrconf.c

@@ -2421,9 +2421,9 @@ static struct fib6_info *addrconf_get_prefix_route(const struct in6_addr *pfx,
 		goto out;
 
 	for_each_fib6_node_rt_rcu(fn) {
-		if (rt->fib6_nh.fib_nh_dev->ifindex != dev->ifindex)
+		if (rt->fib6_nh->fib_nh_dev->ifindex != dev->ifindex)
 			continue;
-		if (no_gw && rt->fib6_nh.fib_nh_gw_family)
+		if (no_gw && rt->fib6_nh->fib_nh_gw_family)
 			continue;
 		if ((rt->fib6_flags & flags) != flags)
 			continue;
@@ -6341,16 +6341,16 @@ void addrconf_disable_policy_idev(struct inet6_dev *idev, int val)
 	list_for_each_entry(ifa, &idev->addr_list, if_list) {
 		spin_lock(&ifa->lock);
 		if (ifa->rt) {
-			struct fib6_info *rt = ifa->rt;
+			struct fib6_nh *nh = ifa->rt->fib6_nh;
 			int cpu;
 
 			rcu_read_lock();
 			ifa->rt->dst_nopolicy = val ? true : false;
-			if (rt->rt6i_pcpu) {
+			if (nh->rt6i_pcpu) {
 				for_each_possible_cpu(cpu) {
 					struct rt6_info **rtp;
 
-					rtp = per_cpu_ptr(rt->rt6i_pcpu, cpu);
+					rtp = per_cpu_ptr(nh->rt6i_pcpu, cpu);
 					addrconf_set_nopolicy(*rtp, val);
 				}
 			}

net/ipv6/ip6_fib.c

@@ -147,19 +147,17 @@ static __be32 addr_bit_set(const void *token, int fn_bit)
 	       addr[fn_bit >> 5];
 }
 
-struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
+struct fib6_info *fib6_info_alloc(gfp_t gfp_flags, bool with_fib6_nh)
 {
 	struct fib6_info *f6i;
+	size_t sz = sizeof(*f6i);
 
-	f6i = kzalloc(sizeof(*f6i), gfp_flags);
-	if (!f6i)
-		return NULL;
+	if (with_fib6_nh)
+		sz += sizeof(struct fib6_nh);
 
-	f6i->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
-	if (!f6i->rt6i_pcpu) {
-		kfree(f6i);
+	f6i = kzalloc(sz, gfp_flags);
+	if (!f6i)
 		return NULL;
-	}
 
 	INIT_LIST_HEAD(&f6i->fib6_siblings);
 	refcount_set(&f6i->fib6_ref, 1);
@@ -170,36 +168,11 @@ struct fib6_info *fib6_info_alloc(gfp_t gfp_flags)
 void fib6_info_destroy_rcu(struct rcu_head *head)
 {
 	struct fib6_info *f6i = container_of(head, struct fib6_info, rcu);
-	struct rt6_exception_bucket *bucket;
 
 	WARN_ON(f6i->fib6_node);
 
-	bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket, 1);
-	kfree(bucket);
-
-	if (f6i->rt6i_pcpu) {
-		int cpu;
-
-		for_each_possible_cpu(cpu) {
-			struct rt6_info **ppcpu_rt;
-			struct rt6_info *pcpu_rt;
-
-			ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu);
-			pcpu_rt = *ppcpu_rt;
-			if (pcpu_rt) {
-				dst_dev_put(&pcpu_rt->dst);
-				dst_release(&pcpu_rt->dst);
-				*ppcpu_rt = NULL;
-			}
-		}
-
-		free_percpu(f6i->rt6i_pcpu);
-	}
-
-	fib6_nh_release(&f6i->fib6_nh);
-
+	fib6_nh_release(f6i->fib6_nh);
 	ip_fib_metrics_put(f6i->fib6_metrics);
-
 	kfree(f6i);
 }
 EXPORT_SYMBOL_GPL(fib6_info_destroy_rcu);
@@ -899,16 +872,14 @@ static struct fib6_node *fib6_add_1(struct net *net,
 	return ln;
 }
 
-static void fib6_drop_pcpu_from(struct fib6_info *f6i,
+static void __fib6_drop_pcpu_from(struct fib6_nh *fib6_nh,
+				  const struct fib6_info *match,
 				  const struct fib6_table *table)
 {
 	int cpu;
 
-	/* Make sure rt6_make_pcpu_route() wont add other percpu routes
-	 * while we are cleaning them here.
-	 */
-	f6i->fib6_destroying = 1;
-	mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
+	if (!fib6_nh->rt6i_pcpu)
+		return;
 
 	/* release the reference to this fib entry from
 	 * all of its cached pcpu routes
@@ -917,9 +888,15 @@ static void fib6_drop_pcpu_from(struct fib6_info *f6i,
 		struct rt6_info **ppcpu_rt;
 		struct rt6_info *pcpu_rt;
 
-		ppcpu_rt = per_cpu_ptr(f6i->rt6i_pcpu, cpu);
+		ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
 		pcpu_rt = *ppcpu_rt;
-		if (pcpu_rt) {
+
+		/* only dropping the 'from' reference if the cached route
+		 * is using 'match'. The cached pcpu_rt->from only changes
+		 * from a fib6_info to NULL (ip6_dst_destroy); it can never
+		 * change from one fib6_info reference to another
+		 */
+		if (pcpu_rt && rcu_access_pointer(pcpu_rt->from) == match) {
 			struct fib6_info *from;
 
 			from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
@@ -928,12 +905,26 @@ static void fib6_drop_pcpu_from(struct fib6_info *f6i,
 	}
 }
 
+static void fib6_drop_pcpu_from(struct fib6_info *f6i,
+				const struct fib6_table *table)
+{
+	struct fib6_nh *fib6_nh;
+
+	/* Make sure rt6_make_pcpu_route() wont add other percpu routes
+	 * while we are cleaning them here.
+	 */
+	f6i->fib6_destroying = 1;
+	mb(); /* paired with the cmpxchg() in rt6_make_pcpu_route() */
+
+	fib6_nh = f6i->fib6_nh;
+	__fib6_drop_pcpu_from(fib6_nh, f6i, table);
+}
+
 static void fib6_purge_rt(struct fib6_info *rt, struct fib6_node *fn,
 			  struct net *net)
 {
 	struct fib6_table *table = rt->fib6_table;
 
-	if (rt->rt6i_pcpu)
 	fib6_drop_pcpu_from(rt, table);
 
 	if (refcount_read(&rt->fib6_ref) != 1) {
@@ -2314,14 +2305,14 @@ static int ipv6_route_seq_show(struct seq_file *seq, void *v)
 #else
 	seq_puts(seq, "00000000000000000000000000000000 00 ");
 #endif
-	if (rt->fib6_nh.fib_nh_gw_family) {
+	if (rt->fib6_nh->fib_nh_gw_family) {
 		flags |= RTF_GATEWAY;
-		seq_printf(seq, "%pi6", &rt->fib6_nh.fib_nh_gw6);
+		seq_printf(seq, "%pi6", &rt->fib6_nh->fib_nh_gw6);
 	} else {
 		seq_puts(seq, "00000000000000000000000000000000");
 	}
 
-	dev = rt->fib6_nh.fib_nh_dev;
+	dev = rt->fib6_nh->fib_nh_dev;
 	seq_printf(seq, " %08x %08x %08x %08x %8s\n",
 		   rt->fib6_metric, refcount_read(&rt->fib6_ref), 0,
 		   flags, dev ? dev->name : "");

net/ipv6/ndisc.c

@@ -1293,8 +1293,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 	rt = rt6_get_dflt_router(net, &ipv6_hdr(skb)->saddr, skb->dev);
 
 	if (rt) {
-		neigh = ip6_neigh_lookup(&rt->fib6_nh.fib_nh_gw6,
-					 rt->fib6_nh.fib_nh_dev, NULL,
+		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
+					 rt->fib6_nh->fib_nh_dev, NULL,
 					  &ipv6_hdr(skb)->saddr);
 		if (!neigh) {
 			ND_PRINTK(0, err,
@@ -1323,8 +1323,8 @@ static void ndisc_router_discovery(struct sk_buff *skb)
 			return;
 		}
 
-		neigh = ip6_neigh_lookup(&rt->fib6_nh.fib_nh_gw6,
-					 rt->fib6_nh.fib_nh_dev, NULL,
+		neigh = ip6_neigh_lookup(&rt->fib6_nh->fib_nh_gw6,
+					 rt->fib6_nh->fib_nh_dev, NULL,
 					  &ipv6_hdr(skb)->saddr);
 		if (!neigh) {
 			ND_PRINTK(0, err,

net/ipv6/route.c

@@ -441,12 +441,12 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
 	if (!fl6->mp_hash)
 		fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
 
-	if (fl6->mp_hash <= atomic_read(&match->fib6_nh.fib_nh_upper_bound))
+	if (fl6->mp_hash <= atomic_read(&match->fib6_nh->fib_nh_upper_bound))
 		goto out;
 
 	list_for_each_entry_safe(sibling, next_sibling, &match->fib6_siblings,
 				 fib6_siblings) {
-		const struct fib6_nh *nh = &sibling->fib6_nh;
+		const struct fib6_nh *nh = sibling->fib6_nh;
 		int nh_upper_bound;
 
 		nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
@@ -460,7 +460,7 @@ void fib6_select_path(const struct net *net, struct fib6_result *res,
 
 out:
 	res->f6i = match;
-	res->nh = &match->fib6_nh;
+	res->nh = match->fib6_nh;
 }
 
 /*
@@ -496,13 +496,13 @@ static void rt6_device_match(struct net *net, struct fib6_result *res,
 	struct fib6_nh *nh;
 
 	if (!oif && ipv6_addr_any(saddr)) {
-		nh = &f6i->fib6_nh;
+		nh = f6i->fib6_nh;
 		if (!(nh->fib_nh_flags & RTNH_F_DEAD))
 			goto out;
 	}
 
 	for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
-		nh = &spf6i->fib6_nh;
+		nh = spf6i->fib6_nh;
 		if (__rt6_device_match(net, nh, saddr, oif, flags)) {
 			res->f6i = spf6i;
 			goto out;
@@ -511,14 +511,14 @@ static void rt6_device_match(struct net *net, struct fib6_result *res,
 
 	if (oif && flags & RT6_LOOKUP_F_IFACE) {
 		res->f6i = net->ipv6.fib6_null_entry;
-		nh = &res->f6i->fib6_nh;
+		nh = res->f6i->fib6_nh;
 		goto out;
 	}
 
-	nh = &f6i->fib6_nh;
+	nh = f6i->fib6_nh;
 	if (nh->fib_nh_flags & RTNH_F_DEAD) {
 		res->f6i = net->ipv6.fib6_null_entry;
-		nh = &res->f6i->fib6_nh;
+		nh = res->f6i->fib6_nh;
 	}
 out:
 	res->nh = nh;
@@ -714,7 +714,7 @@ static void __find_rr_leaf(struct fib6_info *f6i_start,
 		if (fib6_check_expired(f6i))
 			continue;
 
-		nh = &f6i->fib6_nh;
+		nh = f6i->fib6_nh;
 		if (find_match(nh, f6i->fib6_flags, oif, strict, mpri, do_rr)) {
 			res->f6i = f6i;
 			res->nh = nh;
@@ -796,7 +796,7 @@ static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
 out:
 	if (!res->f6i) {
 		res->f6i = net->ipv6.fib6_null_entry;
-		res->nh = &res->f6i->fib6_nh;
+		res->nh = res->f6i->fib6_nh;
 		res->fib6_flags = res->f6i->fib6_flags;
 		res->fib6_type = res->f6i->fib6_type;
 	}
@@ -1270,7 +1270,7 @@ static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
 {
 	struct rt6_info *pcpu_rt, **p;
 
-	p = this_cpu_ptr(res->f6i->rt6i_pcpu);
+	p = this_cpu_ptr(res->nh->rt6i_pcpu);
 	pcpu_rt = *p;
 
 	if (pcpu_rt)
@@ -1291,7 +1291,7 @@ static struct rt6_info *rt6_make_pcpu_route(struct net *net,
 	}
 
 	dst_hold(&pcpu_rt->dst);
-	p = this_cpu_ptr(res->f6i->rt6i_pcpu);
+	p = this_cpu_ptr(res->nh->rt6i_pcpu);
 	prev = cmpxchg(p, NULL, pcpu_rt);
 	BUG_ON(prev);
 
@@ -1461,24 +1461,73 @@ static unsigned int fib6_mtu(const struct fib6_result *res)
 	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
 }
 
+#define FIB6_EXCEPTION_BUCKET_FLUSHED  0x1UL
+
+/* used when the flushed bit is not relevant, only access to the bucket
+ * (ie., all bucket users except rt6_insert_exception);
+ *
+ * called under rcu lock; sometimes called with rt6_exception_lock held
+ */
+static
+struct rt6_exception_bucket *fib6_nh_get_excptn_bucket(const struct fib6_nh *nh,
+						       spinlock_t *lock)
+{
+	struct rt6_exception_bucket *bucket;
+
+	if (lock)
+		bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
+						   lockdep_is_held(lock));
+	else
+		bucket = rcu_dereference(nh->rt6i_exception_bucket);
+
+	/* remove bucket flushed bit if set */
+	if (bucket) {
+		unsigned long p = (unsigned long)bucket;
+
+		p &= ~FIB6_EXCEPTION_BUCKET_FLUSHED;
+		bucket = (struct rt6_exception_bucket *)p;
+	}
+
+	return bucket;
+}
+
+static bool fib6_nh_excptn_bucket_flushed(struct rt6_exception_bucket *bucket)
+{
+	unsigned long p = (unsigned long)bucket;
+
+	return !!(p & FIB6_EXCEPTION_BUCKET_FLUSHED);
+}
+
+/* called with rt6_exception_lock held */
+static void fib6_nh_excptn_bucket_set_flushed(struct fib6_nh *nh,
+					      spinlock_t *lock)
+{
+	struct rt6_exception_bucket *bucket;
+	unsigned long p;
+
+	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
+					   lockdep_is_held(lock));
+
+	p = (unsigned long)bucket;
+	p |= FIB6_EXCEPTION_BUCKET_FLUSHED;
+	bucket = (struct rt6_exception_bucket *)p;
+	rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
+}
+
 static int rt6_insert_exception(struct rt6_info *nrt,
 				const struct fib6_result *res)
 {
 	struct net *net = dev_net(nrt->dst.dev);
 	struct rt6_exception_bucket *bucket;
+	struct fib6_info *f6i = res->f6i;
 	struct in6_addr *src_key = NULL;
 	struct rt6_exception *rt6_ex;
-	struct fib6_info *f6i = res->f6i;
+	struct fib6_nh *nh = res->nh;
 	int err = 0;
 
 	spin_lock_bh(&rt6_exception_lock);
 
-	if (f6i->exception_bucket_flushed) {
-		err = -EINVAL;
-		goto out;
-	}
-
-	bucket = rcu_dereference_protected(f6i->rt6i_exception_bucket,
+	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
 					  lockdep_is_held(&rt6_exception_lock));
 	if (!bucket) {
 		bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
@@ -1487,7 +1536,10 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 			err = -ENOMEM;
 			goto out;
 		}
-		rcu_assign_pointer(f6i->rt6i_exception_bucket, bucket);
+		rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
+	} else if (fib6_nh_excptn_bucket_flushed(bucket)) {
+		err = -EINVAL;
+		goto out;
 	}
 
 #ifdef CONFIG_IPV6_SUBTREES
@@ -1542,7 +1594,7 @@ static int rt6_insert_exception(struct rt6_info *nrt,
 	return err;
 }
 
-void rt6_flush_exceptions(struct fib6_info *rt)
+static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
 {
 	struct rt6_exception_bucket *bucket;
 	struct rt6_exception *rt6_ex;
@@ -1550,25 +1602,33 @@ void rt6_flush_exceptions(struct fib6_info *rt)
 	int i;
 
 	spin_lock_bh(&rt6_exception_lock);
-	/* Prevent rt6_insert_exception() to recreate the bucket list */
-	rt->exception_bucket_flushed = 1;
 
-	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
-				    lockdep_is_held(&rt6_exception_lock));
+	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
 	if (!bucket)
 		goto out;
 
+	/* Prevent rt6_insert_exception() to recreate the bucket list */
+	if (!from)
+		fib6_nh_excptn_bucket_set_flushed(nh, &rt6_exception_lock);
+
 	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
-		hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist)
+		hlist_for_each_entry_safe(rt6_ex, tmp, &bucket->chain, hlist) {
+			if (!from ||
+			    rcu_access_pointer(rt6_ex->rt6i->from) == from)
 				rt6_remove_exception(bucket, rt6_ex);
-		WARN_ON_ONCE(bucket->depth);
+		}
+		WARN_ON_ONCE(!from && bucket->depth);
 		bucket++;
 	}
-
 out:
 	spin_unlock_bh(&rt6_exception_lock);
 }
 
+void rt6_flush_exceptions(struct fib6_info *f6i)
+{
+	fib6_nh_flush_exceptions(f6i->fib6_nh, f6i);
+}
+
 /* Find cached rt in the hash table inside passed in rt
  * Caller has to hold rcu_read_lock()
  */
@@ -1597,7 +1657,7 @@ static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 		src_key = saddr;
 find_ex:
 #endif
-	bucket = rcu_dereference(res->f6i->rt6i_exception_bucket);
+	bucket = fib6_nh_get_excptn_bucket(res->nh, NULL);
 	rt6_ex = __rt6_find_exception_rcu(&bucket, daddr, src_key);
 
 	if (rt6_ex && !rt6_check_expired(rt6_ex->rt6i))
@@ -1615,25 +1675,20 @@ static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
 }
 
 /* Remove the passed in cached rt from the hash table that contains it */
-static int rt6_remove_exception_rt(struct rt6_info *rt)
+static int fib6_nh_remove_exception(const struct fib6_nh *nh, int plen,
+				    const struct rt6_info *rt)
 {
+	const struct in6_addr *src_key = NULL;
 	struct rt6_exception_bucket *bucket;
-	struct in6_addr *src_key = NULL;
 	struct rt6_exception *rt6_ex;
-	struct fib6_info *from;
 	int err;
 
-	from = rcu_dereference(rt->from);
-	if (!from ||
-	    !(rt->rt6i_flags & RTF_CACHE))
-		return -EINVAL;
-
-	if (!rcu_access_pointer(from->rt6i_exception_bucket))
+	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
 		return -ENOENT;
 
 	spin_lock_bh(&rt6_exception_lock);
-	bucket = rcu_dereference_protected(from->rt6i_exception_bucket,
-				    lockdep_is_held(&rt6_exception_lock));
+	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
+
 #ifdef CONFIG_IPV6_SUBTREES
 	/* rt6i_src.plen != 0 indicates 'from' is in subtree
 	 * and exception table is indexed by a hash of
@@ -1641,7 +1696,7 @@ static int rt6_remove_exception_rt(struct rt6_info *rt)
 	 * Otherwise, the exception table is indexed by
 	 * a hash of only rt6i_dst.
 	 */
-	if (from->fib6_src.plen)
+	if (plen)
 		src_key = &rt->rt6i_src.addr;
 #endif
 	rt6_ex = __rt6_find_exception_spinlock(&bucket,
@@ -1658,23 +1713,29 @@ static int rt6_remove_exception_rt(struct rt6_info *rt)
 	return err;
 }
 
-/* Find rt6_ex which contains the passed in rt cache and
- * refresh its stamp
- */
-static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
+static int rt6_remove_exception_rt(struct rt6_info *rt)
 {
-	struct rt6_exception_bucket *bucket;
-	struct in6_addr *src_key = NULL;
-	struct rt6_exception *rt6_ex;
 	struct fib6_info *from;
 
-	rcu_read_lock();
 	from = rcu_dereference(rt->from);
 	if (!from || !(rt->rt6i_flags & RTF_CACHE))
-		goto unlock;
+		return -EINVAL;
 
-	bucket = rcu_dereference(from->rt6i_exception_bucket);
+	return fib6_nh_remove_exception(from->fib6_nh,
+					from->fib6_src.plen, rt);
+}
+
+/* Find rt6_ex which contains the passed in rt cache and
+ * refresh its stamp
+ */
+static void fib6_nh_update_exception(const struct fib6_nh *nh, int plen,
+				     const struct rt6_info *rt)
+{
+	const struct in6_addr *src_key = NULL;
+	struct rt6_exception_bucket *bucket;
+	struct rt6_exception *rt6_ex;
 
+	bucket = fib6_nh_get_excptn_bucket(nh, NULL);
 #ifdef CONFIG_IPV6_SUBTREES
 	/* rt6i_src.plen != 0 indicates 'from' is in subtree
 	 * and exception table is indexed by a hash of
@@ -1682,15 +1743,25 @@ static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
 	 * Otherwise, the exception table is indexed by
 	 * a hash of only rt6i_dst.
 	 */
-	if (from->fib6_src.plen)
+	if (plen)
 		src_key = &rt->rt6i_src.addr;
 #endif
-	rt6_ex = __rt6_find_exception_rcu(&bucket,
-					  &rt->rt6i_dst.addr,
-					  src_key);
+	rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
 	if (rt6_ex)
 		rt6_ex->stamp = jiffies;
+}
+
+static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
+{
+	struct fib6_info *from;
+
+	rcu_read_lock();
 
+	from = rcu_dereference(rt->from);
+	if (!from || !(rt->rt6i_flags & RTF_CACHE))
+		goto unlock;
+
+	fib6_nh_update_exception(from->fib6_nh, from->fib6_src.plen, rt);
 unlock:
 	rcu_read_unlock();
 }
@@ -1718,15 +1789,13 @@ static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
 }
 
 static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
-				       struct fib6_info *rt, int mtu)
+				       const struct fib6_nh *nh, int mtu)
 {
 	struct rt6_exception_bucket *bucket;
 	struct rt6_exception *rt6_ex;
 	int i;
 
-	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
-					lockdep_is_held(&rt6_exception_lock));
-
+	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
 	if (!bucket)
 		return;
 
@@ -1748,21 +1817,19 @@ static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
 
 #define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)
 
-static void rt6_exceptions_clean_tohost(struct fib6_info *rt,
-					struct in6_addr *gateway)
+static void fib6_nh_exceptions_clean_tohost(const struct fib6_nh *nh,
+					    const struct in6_addr *gateway)
 {
 	struct rt6_exception_bucket *bucket;
 	struct rt6_exception *rt6_ex;
 	struct hlist_node *tmp;
 	int i;
 
-	if (!rcu_access_pointer(rt->rt6i_exception_bucket))
+	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
 		return;
 
 	spin_lock_bh(&rt6_exception_lock);
-	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
-				     lockdep_is_held(&rt6_exception_lock));
-
+	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
 	if (bucket) {
 		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
 			hlist_for_each_entry_safe(rt6_ex, tmp,
@@ -1827,7 +1894,7 @@ static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
 	gc_args->more++;
 }
 
-void rt6_age_exceptions(struct fib6_info *rt,
+static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
 				   struct fib6_gc_args *gc_args,
 				   unsigned long now)
 {
@@ -1836,14 +1903,12 @@ void rt6_age_exceptions(struct fib6_info *rt,
 	struct hlist_node *tmp;
 	int i;
 
-	if (!rcu_access_pointer(rt->rt6i_exception_bucket))
+	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
 		return;
 
 	rcu_read_lock_bh();
 	spin_lock(&rt6_exception_lock);
-	bucket = rcu_dereference_protected(rt->rt6i_exception_bucket,
-				    lockdep_is_held(&rt6_exception_lock));
-
+	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
 	if (bucket) {
 		for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
 			hlist_for_each_entry_safe(rt6_ex, tmp,
@@ -1858,6 +1923,13 @@ void rt6_age_exceptions(struct fib6_info *rt,
 	rcu_read_unlock_bh();
 }
 
+void rt6_age_exceptions(struct fib6_info *f6i,
+			struct fib6_gc_args *gc_args,
+			unsigned long now)
+{
+	fib6_nh_age_exceptions(f6i->fib6_nh, gc_args, now);
+}
+
 /* must be called with rcu lock held */
 int fib6_table_lookup(struct net *net, struct fib6_table *table, int oif,
 		      struct flowi6 *fl6, struct fib6_result *res, int strict)
@@ -2384,7 +2456,7 @@ static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
 			rcu_read_unlock();
 			return;
 		}
-		res.nh = &res.f6i->fib6_nh;
+		res.nh = res.f6i->fib6_nh;
 		res.fib6_flags = res.f6i->fib6_flags;
 		res.fib6_type = res.f6i->fib6_type;
 
@@ -2527,7 +2599,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
 restart:
 	for_each_fib6_node_rt_rcu(fn) {
 		res.f6i = rt;
-		res.nh = &rt->fib6_nh;
+		res.nh = rt->fib6_nh;
 
 		if (fib6_check_expired(rt))
 			continue;
@@ -2551,7 +2623,7 @@ static struct rt6_info *__ip6_route_redirect(struct net *net,
 	}
 
 	res.f6i = rt;
-	res.nh = &rt->fib6_nh;
+	res.nh = rt->fib6_nh;
 out:
 	if (ret) {
 		ip6_hold_safe(net, &ret);
@@ -3068,6 +3140,12 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 	    !netif_carrier_ok(dev))
 		fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
 
+	fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
+	if (!fib6_nh->rt6i_pcpu) {
+		err = -ENOMEM;
+		goto out;
+	}
+
 	err = fib_nh_common_init(&fib6_nh->nh_common, cfg->fc_encap,
 				 cfg->fc_encap_type, cfg, gfp_flags, extack);
 	if (err)
@@ -3092,6 +3170,38 @@ int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
 
 void fib6_nh_release(struct fib6_nh *fib6_nh)
 {
+	struct rt6_exception_bucket *bucket;
+
+	rcu_read_lock();
+
+	fib6_nh_flush_exceptions(fib6_nh, NULL);
+	bucket = fib6_nh_get_excptn_bucket(fib6_nh, NULL);
+	if (bucket) {
+		rcu_assign_pointer(fib6_nh->rt6i_exception_bucket, NULL);
+		kfree(bucket);
+	}
+
+	rcu_read_unlock();
+
+	if (fib6_nh->rt6i_pcpu) {
+		int cpu;
+
+		for_each_possible_cpu(cpu) {
+			struct rt6_info **ppcpu_rt;
+			struct rt6_info *pcpu_rt;
+
+			ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
+			pcpu_rt = *ppcpu_rt;
+			if (pcpu_rt) {
+				dst_dev_put(&pcpu_rt->dst);
+				dst_release(&pcpu_rt->dst);
+				*ppcpu_rt = NULL;
+			}
+		}
+
+		free_percpu(fib6_nh->rt6i_pcpu);
+	}
+
 	fib_nh_common_release(&fib6_nh->nh_common);
 }
 
@@ -3154,7 +3264,7 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
 		goto out;
 
 	err = -ENOMEM;
-	rt = fib6_info_alloc(gfp_flags);
+	rt = fib6_info_alloc(gfp_flags, true);
 	if (!rt)
 		goto out;
 
@@ -3194,7 +3304,7 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
 	ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
 	rt->fib6_src.plen = cfg->fc_src_len;
 #endif
-	err = fib6_nh_init(net, &rt->fib6_nh, cfg, gfp_flags, extack);
+	err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
 	if (err)
 		goto out;
 
@@ -3202,7 +3312,7 @@ static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
 	 * they would result in kernel looping; promote them to reject routes
 	 */
 	addr_type = ipv6_addr_type(&cfg->fc_dst);
-	if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh.fib_nh_dev, addr_type))
+	if (fib6_is_reject(cfg->fc_flags, rt->fib6_nh->fib_nh_dev, addr_type))
 		rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
 
 	if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
@@ -3320,7 +3430,7 @@ static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
 	return err;
 }
 
-static int ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
+static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
 {
 	int rc = -ESRCH;
 
@@ -3336,10 +3446,25 @@ static int ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
 	return rc;
 }
 
+static int ip6_del_cached_rt(struct fib6_config *cfg, struct fib6_info *rt,
+			     struct fib6_nh *nh)
+{
+	struct fib6_result res = {
+		.f6i = rt,
+		.nh = nh,
+	};
+	struct rt6_info *rt_cache;
+
+	rt_cache = rt6_find_cached_rt(&res, &cfg->fc_dst, &cfg->fc_src);
+	if (rt_cache)
+		return __ip6_del_cached_rt(rt_cache, cfg);
+
+	return 0;
+}
+
 static int ip6_route_del(struct fib6_config *cfg,
 			 struct netlink_ext_ack *extack)
 {
-	struct rt6_info *rt_cache;
 	struct fib6_table *table;
 	struct fib6_info *rt;
 	struct fib6_node *fn;
@@ -3362,26 +3487,18 @@ static int ip6_route_del(struct fib6_config *cfg,
 		for_each_fib6_node_rt_rcu(fn) {
 			struct fib6_nh *nh;
 
+			nh = rt->fib6_nh;
 			if (cfg->fc_flags & RTF_CACHE) {
-				struct fib6_result res = {
-					.f6i = rt,
-				};
 				int rc;
 
-				rt_cache = rt6_find_cached_rt(&res,
-							      &cfg->fc_dst,
-							      &cfg->fc_src);
-				if (rt_cache) {
-					rc = ip6_del_cached_rt(rt_cache, cfg);
+				rc = ip6_del_cached_rt(cfg, rt, nh);
 				if (rc != -ESRCH) {
 					rcu_read_unlock();
 					return rc;
 				}
-				}
 				continue;
 			}
 
-			nh = &rt->fib6_nh;
 			if (cfg->fc_ifindex &&
 			    (!nh->fib_nh_dev ||
 			     nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
@@ -3503,7 +3620,7 @@ static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_bu
 	if (!res.f6i)
 		goto out;
 
-	res.nh = &res.f6i->fib6_nh;
+	res.nh = res.f6i->fib6_nh;
 	res.fib6_flags = res.f6i->fib6_flags;
 	res.fib6_type = res.f6i->fib6_type;
 	nrt = ip6_rt_cache_alloc(&res, &msg->dest, NULL);
@@ -3555,12 +3672,12 @@ static struct fib6_info *rt6_get_route_info(struct net *net,
 		goto out;
 
 	for_each_fib6_node_rt_rcu(fn) {
-		if (rt->fib6_nh.fib_nh_dev->ifindex != ifindex)
+		if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
 			continue;
 		if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
-		    !rt->fib6_nh.fib_nh_gw_family)
+		    !rt->fib6_nh->fib_nh_gw_family)
 			continue;
-		if (!ipv6_addr_equal(&rt->fib6_nh.fib_nh_gw6, gwaddr))
+		if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
 			continue;
 		if (!fib6_info_hold_safe(rt))
 			continue;
@@ -3618,7 +3735,7 @@ struct fib6_info *rt6_get_dflt_router(struct net *net,
 
 	rcu_read_lock();
 	for_each_fib6_node_rt_rcu(&table->tb6_root) {
-		struct fib6_nh *nh = &rt->fib6_nh;
+		struct fib6_nh *nh = rt->fib6_nh;
 
 		if (dev == nh->fib_nh_dev &&
 		    ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
@@ -3870,7 +3987,7 @@ static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
 	struct net *net = ((struct arg_dev_net_ip *)arg)->net;
 	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
 
-	if (((void *)rt->fib6_nh.fib_nh_dev == dev || !dev) &&
+	if (((void *)rt->fib6_nh->fib_nh_dev == dev || !dev) &&
 	    rt != net->ipv6.fib6_null_entry &&
 	    ipv6_addr_equal(addr, &rt->fib6_prefsrc.addr)) {
 		spin_lock_bh(&rt6_exception_lock);
@@ -3898,18 +4015,17 @@ void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
 static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
 {
 	struct in6_addr *gateway = (struct in6_addr *)arg;
+	struct fib6_nh *nh = rt->fib6_nh;
 
 	if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
-	    rt->fib6_nh.fib_nh_gw_family &&
-	    ipv6_addr_equal(gateway, &rt->fib6_nh.fib_nh_gw6)) {
+	    nh->fib_nh_gw_family && ipv6_addr_equal(gateway, &nh->fib_nh_gw6))
 		return -1;
-	}
 
 	/* Further clean up cached routes in exception table.
 	 * This is needed because cached route may have a different
 	 * gateway than its 'parent' in the case of an ip redirect.
 	 */
-	rt6_exceptions_clean_tohost(rt, gateway);
+	fib6_nh_exceptions_clean_tohost(nh, gateway);
 
 	return 0;
 }
@@ -3949,9 +4065,9 @@ static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
 
 static bool rt6_is_dead(const struct fib6_info *rt)
 {
-	if (rt->fib6_nh.fib_nh_flags & RTNH_F_DEAD ||
-	    (rt->fib6_nh.fib_nh_flags & RTNH_F_LINKDOWN &&
-	     ip6_ignore_linkdown(rt->fib6_nh.fib_nh_dev)))
+	if (rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD ||
+	    (rt->fib6_nh->fib_nh_flags & RTNH_F_LINKDOWN &&
+	     ip6_ignore_linkdown(rt->fib6_nh->fib_nh_dev)))
 		return true;
 
 	return false;
@@ -3963,11 +4079,11 @@ static int rt6_multipath_total_weight(const struct fib6_info *rt)
 	int total = 0;
 
 	if (!rt6_is_dead(rt))
-		total += rt->fib6_nh.fib_nh_weight;
+		total += rt->fib6_nh->fib_nh_weight;
 
 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
 		if (!rt6_is_dead(iter))
-			total += iter->fib6_nh.fib_nh_weight;
+			total += iter->fib6_nh->fib_nh_weight;
 	}
 
 	return total;
@@ -3978,11 +4094,11 @@ static void rt6_upper_bound_set(struct fib6_info *rt, int *weight, int total)
 	int upper_bound = -1;
 
 	if (!rt6_is_dead(rt)) {
-		*weight += rt->fib6_nh.fib_nh_weight;
+		*weight += rt->fib6_nh->fib_nh_weight;
 		upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
 						    total) - 1;
 	}
-	atomic_set(&rt->fib6_nh.fib_nh_upper_bound, upper_bound);
+	atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
 }
 
 static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
@@ -4026,8 +4142,8 @@ static int fib6_ifup(struct fib6_info *rt, void *p_arg)
 	struct net *net = dev_net(arg->dev);
 
 	if (rt != net->ipv6.fib6_null_entry &&
-	    rt->fib6_nh.fib_nh_dev == arg->dev) {
-		rt->fib6_nh.fib_nh_flags &= ~arg->nh_flags;
+	    rt->fib6_nh->fib_nh_dev == arg->dev) {
+		rt->fib6_nh->fib_nh_flags &= ~arg->nh_flags;
 		fib6_update_sernum_upto_root(net, rt);
 		rt6_multipath_rebalance(rt);
 	}
@@ -4055,10 +4171,10 @@ static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
 {
 	struct fib6_info *iter;
 
-	if (rt->fib6_nh.fib_nh_dev == dev)
+	if (rt->fib6_nh->fib_nh_dev == dev)
 		return true;
 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
-		if (iter->fib6_nh.fib_nh_dev == dev)
+		if (iter->fib6_nh->fib_nh_dev == dev)
 			return true;
 
 	return false;
@@ -4079,12 +4195,12 @@ static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
 	struct fib6_info *iter;
 	unsigned int dead = 0;
 
-	if (rt->fib6_nh.fib_nh_dev == down_dev ||
-	    rt->fib6_nh.fib_nh_flags & RTNH_F_DEAD)
+	if (rt->fib6_nh->fib_nh_dev == down_dev ||
+	    rt->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
 		dead++;
 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
-		if (iter->fib6_nh.fib_nh_dev == down_dev ||
-		    iter->fib6_nh.fib_nh_flags & RTNH_F_DEAD)
+		if (iter->fib6_nh->fib_nh_dev == down_dev ||
+		    iter->fib6_nh->fib_nh_flags & RTNH_F_DEAD)
 			dead++;
 
 	return dead;
@@ -4096,11 +4212,11 @@ static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
 {
 	struct fib6_info *iter;
 
-	if (rt->fib6_nh.fib_nh_dev == dev)
-		rt->fib6_nh.fib_nh_flags |= nh_flags;
+	if (rt->fib6_nh->fib_nh_dev == dev)
+		rt->fib6_nh->fib_nh_flags |= nh_flags;
 	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
-		if (iter->fib6_nh.fib_nh_dev == dev)
-			iter->fib6_nh.fib_nh_flags |= nh_flags;
+		if (iter->fib6_nh->fib_nh_dev == dev)
+			iter->fib6_nh->fib_nh_flags |= nh_flags;
 }
 
 /* called with write lock held for table with rt */
@@ -4115,12 +4231,12 @@ static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
 
 	switch (arg->event) {
 	case NETDEV_UNREGISTER:
-		return rt->fib6_nh.fib_nh_dev == dev ? -1 : 0;
+		return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
 	case NETDEV_DOWN:
 		if (rt->should_flush)
 			return -1;
 		if (!rt->fib6_nsiblings)
-			return rt->fib6_nh.fib_nh_dev == dev ? -1 : 0;
+			return rt->fib6_nh->fib_nh_dev == dev ? -1 : 0;
 		if (rt6_multipath_uses_dev(rt, dev)) {
 			unsigned int count;
 
@@ -4136,10 +4252,10 @@ static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
 		}
 		return -2;
 	case NETDEV_CHANGE:
-		if (rt->fib6_nh.fib_nh_dev != dev ||
+		if (rt->fib6_nh->fib_nh_dev != dev ||
 		    rt->fib6_flags & (RTF_LOCAL | RTF_ANYCAST))
 			break;
-		rt->fib6_nh.fib_nh_flags |= RTNH_F_LINKDOWN;
+		rt->fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
 		rt6_multipath_rebalance(rt);
 		break;
 	}
@@ -4173,9 +4289,36 @@ void rt6_disable_ip(struct net_device *dev, unsigned long event)
 struct rt6_mtu_change_arg {
 	struct net_device *dev;
 	unsigned int mtu;
+	struct fib6_info *f6i;
 };
 
-static int rt6_mtu_change_route(struct fib6_info *rt, void *p_arg)
+static int fib6_nh_mtu_change(struct fib6_nh *nh, void *_arg)
+{
+	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *)_arg;
+	struct fib6_info *f6i = arg->f6i;
+
+	/* For administrative MTU increase, there is no way to discover
+	 * IPv6 PMTU increase, so PMTU increase should be updated here.
+	 * Since RFC 1981 doesn't include administrative MTU increase
+	 * update PMTU increase is a MUST. (i.e. jumbo frame)
+	 */
+	if (nh->fib_nh_dev == arg->dev) {
+		struct inet6_dev *idev = __in6_dev_get(arg->dev);
+		u32 mtu = f6i->fib6_pmtu;
+
+		if (mtu >= arg->mtu ||
+		    (mtu < arg->mtu && mtu == idev->cnf.mtu6))
+			fib6_metric_set(f6i, RTAX_MTU, arg->mtu);
+
+		spin_lock_bh(&rt6_exception_lock);
+		rt6_exceptions_update_pmtu(idev, nh, arg->mtu);
+		spin_unlock_bh(&rt6_exception_lock);
+	}
+
+	return 0;
+}
+
+static int rt6_mtu_change_route(struct fib6_info *f6i, void *p_arg)
 {
 	struct rt6_mtu_change_arg *arg = (struct rt6_mtu_change_arg *) p_arg;
 	struct inet6_dev *idev;
@@ -4190,24 +4333,11 @@ static int rt6_mtu_change_route(struct fib6_info *rt, void *p_arg)
 	if (!idev)
 		return 0;
 
-	/* For administrative MTU increase, there is no way to discover
-	   IPv6 PMTU increase, so PMTU increase should be updated here.
-	   Since RFC 1981 doesn't include administrative MTU increase
-	   update PMTU increase is a MUST. (i.e. jumbo frame)
-	 */
-	if (rt->fib6_nh.fib_nh_dev == arg->dev &&
-	    !fib6_metric_locked(rt, RTAX_MTU)) {
-		u32 mtu = rt->fib6_pmtu;
-
-		if (mtu >= arg->mtu ||
-		    (mtu < arg->mtu && mtu == idev->cnf.mtu6))
-			fib6_metric_set(rt, RTAX_MTU, arg->mtu);
-
-		spin_lock_bh(&rt6_exception_lock);
-		rt6_exceptions_update_pmtu(idev, rt, arg->mtu);
-		spin_unlock_bh(&rt6_exception_lock);
-	}
+	if (fib6_metric_locked(f6i, RTAX_MTU))
 		return 0;
+
+	arg->f6i = f6i;
+	return fib6_nh_mtu_change(f6i->fib6_nh, arg);
 }
 
 void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
@@ -4487,7 +4617,7 @@ static int ip6_route_multipath_add(struct fib6_config *cfg,
 			goto cleanup;
 		}
 
-		rt->fib6_nh.fib_nh_weight = rtnh->rtnh_hops + 1;
+		rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
 
 		err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
 					    rt, &r_cfg);
@@ -4654,7 +4784,7 @@ static size_t rt6_nlmsg_size(struct fib6_info *rt)
 		nexthop_len = nla_total_size(0)	 /* RTA_MULTIPATH */
 			    + NLA_ALIGN(sizeof(struct rtnexthop))
 			    + nla_total_size(16) /* RTA_GATEWAY */
-			    + lwtunnel_get_encap_size(rt->fib6_nh.fib_nh_lws);
+			    + lwtunnel_get_encap_size(rt->fib6_nh->fib_nh_lws);
 
 		nexthop_len *= rt->fib6_nsiblings;
 	}
@@ -4672,7 +4802,7 @@ static size_t rt6_nlmsg_size(struct fib6_info *rt)
 	       + nla_total_size(sizeof(struct rta_cacheinfo))
 	       + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
 	       + nla_total_size(1) /* RTA_PREF */
-	       + lwtunnel_get_encap_size(rt->fib6_nh.fib_nh_lws)
+	       + lwtunnel_get_encap_size(rt->fib6_nh->fib_nh_lws)
 	       + nexthop_len;
 }
 
@@ -4792,14 +4922,14 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 		if (!mp)
 			goto nla_put_failure;
 
-		if (fib_add_nexthop(skb, &rt->fib6_nh.nh_common,
-				    rt->fib6_nh.fib_nh_weight) < 0)
+		if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
+				    rt->fib6_nh->fib_nh_weight) < 0)
 			goto nla_put_failure;
 
 		list_for_each_entry_safe(sibling, next_sibling,
 					 &rt->fib6_siblings, fib6_siblings) {
-			if (fib_add_nexthop(skb, &sibling->fib6_nh.nh_common,
-					    sibling->fib6_nh.fib_nh_weight) < 0)
+			if (fib_add_nexthop(skb, &sibling->fib6_nh->nh_common,
+					    sibling->fib6_nh->fib_nh_weight) < 0)
 				goto nla_put_failure;
 		}
 
@@ -4807,7 +4937,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 	} else {
 		unsigned char nh_flags = 0;
 
-		if (fib_nexthop_info(skb, &rt->fib6_nh.nh_common,
+		if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common,
 				     &nh_flags, false) < 0)
 			goto nla_put_failure;
 
@@ -4837,7 +4967,7 @@ static int rt6_fill_node(struct net *net, struct sk_buff *skb,
 static bool fib6_info_uses_dev(const struct fib6_info *f6i,
 			       const struct net_device *dev)
 {
-	if (f6i->fib6_nh.fib_nh_dev == dev)
+	if (f6i->fib6_nh->fib_nh_dev == dev)
 		return true;
 
 	if (f6i->fib6_nsiblings) {
@@ -4845,7 +4975,7 @@ static bool fib6_info_uses_dev(const struct fib6_info *f6i,
 
 		list_for_each_entry_safe(sibling, next_sibling,
 					 &f6i->fib6_siblings, fib6_siblings) {
-			if (sibling->fib6_nh.fib_nh_dev == dev)
+			if (sibling->fib6_nh->fib_nh_dev == dev)
 				return true;
 		}
 	}
@@ -5166,7 +5296,7 @@ static int ip6_route_dev_notify(struct notifier_block *this,
 		return NOTIFY_OK;
 
 	if (event == NETDEV_REGISTER) {
-		net->ipv6.fib6_null_entry->fib6_nh.fib_nh_dev = dev;
+		net->ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = dev;
 		net->ipv6.ip6_null_entry->dst.dev = dev;
 		net->ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(dev);
 #ifdef CONFIG_IPV6_MULTIPLE_TABLES
@@ -5360,11 +5490,11 @@ static int __net_init ip6_route_net_init(struct net *net)
 	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
 		goto out_ip6_dst_ops;
 
-	net->ipv6.fib6_null_entry = kmemdup(&fib6_null_entry_template,
-					    sizeof(*net->ipv6.fib6_null_entry),
-					    GFP_KERNEL);
+	net->ipv6.fib6_null_entry = fib6_info_alloc(GFP_KERNEL, true);
 	if (!net->ipv6.fib6_null_entry)
 		goto out_ip6_dst_entries;
+	memcpy(net->ipv6.fib6_null_entry, &fib6_null_entry_template,
+	       sizeof(*net->ipv6.fib6_null_entry));
 
 	net->ipv6.ip6_null_entry = kmemdup(&ip6_null_entry_template,
 					   sizeof(*net->ipv6.ip6_null_entry),
@@ -5501,7 +5631,7 @@ void __init ip6_route_init_special_entries(void)
 	/* Registering of the loopback is done before this portion of code,
 	 * the loopback reference in rt6_info will not be taken, do it
 	 * manually for init_net */
-	init_net.ipv6.fib6_null_entry->fib6_nh.fib_nh_dev = init_net.loopback_dev;
+	init_net.ipv6.fib6_null_entry->fib6_nh->fib_nh_dev = init_net.loopback_dev;
 	init_net.ipv6.ip6_null_entry->dst.dev = init_net.loopback_dev;
 	init_net.ipv6.ip6_null_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
   #ifdef CONFIG_IPV6_MULTIPLE_TABLES

tools/testing/selftests/net/icmp_redirect.sh

+#!/bin/bash
+# SPDX-License-Identifier: GPL-2.0
+#
+# redirect test
+#
+#                     .253 +----+
+#                     +----| r1 |
+#                     |    +----+
+# +----+              |       |.1
+# | h1 |--------------+       |   10.1.1.0/30 2001:db8:1::0/126
+# +----+ .1           |       |.2
+#         172.16.1/24 |    +----+                   +----+
+#    2001:db8:16:1/64 +----| r2 |-------------------| h2 |
+#                     .254 +----+ .254           .2 +----+
+#                                    172.16.2/24
+#                                  2001:db8:16:2/64
+#
+# Route from h1 to h2 goes through r1, eth1 - connection between r1 and r2.
+# Route on r1 changed to go to r2 via eth0. This causes a redirect to be sent
+# from r1 to h1 telling h1 to use r2 when talking to h2.
+
+VERBOSE=0
+PAUSE_ON_FAIL=no
+
+H1_N1_IP=172.16.1.1
+R1_N1_IP=172.16.1.253
+R2_N1_IP=172.16.1.254
+
+H1_N1_IP6=2001:db8:16:1::1
+R1_N1_IP6=2001:db8:16:1::253
+R2_N1_IP6=2001:db8:16:1::254
+
+R1_R2_N1_IP=10.1.1.1
+R2_R1_N1_IP=10.1.1.2
+
+R1_R2_N1_IP6=2001:db8:1::1
+R2_R1_N1_IP6=2001:db8:1::2
+
+H2_N2=172.16.2.0/24
+H2_N2_6=2001:db8:16:2::/64
+H2_N2_IP=172.16.2.2
+R2_N2_IP=172.16.2.254
+H2_N2_IP6=2001:db8:16:2::2
+R2_N2_IP6=2001:db8:16:2::254
+
+VRF=red
+VRF_TABLE=1111
+
+################################################################################
+# helpers
+
+log_section()
+{
+	echo
+	echo "###########################################################################"
+	echo "$*"
+	echo "###########################################################################"
+	echo
+}
+
+log_test()
+{
+	local rc=$1
+	local expected=$2
+	local msg="$3"
+
+	if [ ${rc} -eq ${expected} ]; then
+		printf "TEST: %-60s  [ OK ]\n" "${msg}"
+		nsuccess=$((nsuccess+1))
+	else
+		ret=1
+		nfail=$((nfail+1))
+		printf "TEST: %-60s  [FAIL]\n" "${msg}"
+		if [ "${PAUSE_ON_FAIL}" = "yes" ]; then
+			echo
+			echo "hit enter to continue, 'q' to quit"
+			read a
+			[ "$a" = "q" ] && exit 1
+		fi
+	fi
+}
+
+run_cmd()
+{
+	local cmd="$*"
+	local out
+	local rc
+
+	if [ "$VERBOSE" = "1" ]; then
+		echo "COMMAND: $cmd"
+	fi
+
+	out=$(eval $cmd 2>&1)
+	rc=$?
+	if [ "$VERBOSE" = "1" -a -n "$out" ]; then
+		echo "$out"
+	fi
+
+	[ "$VERBOSE" = "1" ] && echo
+
+	return $rc
+}
+
+get_linklocal()
+{
+	local ns=$1
+	local dev=$2
+	local addr
+
+	addr=$(ip -netns $ns -6 -br addr show dev ${dev} | \
+	awk '{
+		for (i = 3; i <= NF; ++i) {
+			if ($i ~ /^fe80/)
+				print $i
+		}
+	}'
+	)
+	addr=${addr/\/*}
+
+	[ -z "$addr" ] && return 1
+
+	echo $addr
+
+	return 0
+}
+
+################################################################################
+# setup and teardown
+
+cleanup()
+{
+	local ns
+
+	for ns in h1 h2 r1 r2; do
+		ip netns del $ns 2>/dev/null
+	done
+}
+
+create_vrf()
+{
+	local ns=$1
+
+	ip -netns ${ns} link add ${VRF} type vrf table ${VRF_TABLE}
+	ip -netns ${ns} link set ${VRF} up
+	ip -netns ${ns} route add vrf ${VRF} unreachable default metric 8192
+	ip -netns ${ns} -6 route add vrf ${VRF} unreachable default metric 8192
+
+	ip -netns ${ns} addr add 127.0.0.1/8 dev ${VRF}
+	ip -netns ${ns} -6 addr add ::1 dev ${VRF} nodad
+
+	ip -netns ${ns} ru del pref 0
+	ip -netns ${ns} ru add pref 32765 from all lookup local
+	ip -netns ${ns} -6 ru del pref 0
+	ip -netns ${ns} -6 ru add pref 32765 from all lookup local
+}
+
+setup()
+{
+	local ns
+
+	#
+	# create nodes as namespaces
+	#
+	for ns in h1 h2 r1 r2; do
+		ip netns add $ns
+		ip -netns $ns li set lo up
+
+		case "${ns}" in
+		h[12]) ip netns exec $ns sysctl -q -w net.ipv4.conf.all.accept_redirects=1
+		       ip netns exec $ns sysctl -q -w net.ipv6.conf.all.accept_redirects=1
+		       ip netns exec $ns sysctl -q -w net.ipv6.conf.all.keep_addr_on_down=1
+			;;
+		r[12]) ip netns exec $ns sysctl -q -w net.ipv4.ip_forward=1
+		       ip netns exec $ns sysctl -q -w net.ipv4.conf.all.send_redirects=1
+
+		       ip netns exec $ns sysctl -q -w net.ipv6.conf.all.forwarding=1
+		       ip netns exec $ns sysctl -q -w net.ipv6.route.mtu_expires=10
+		esac
+	done
+
+	#
+	# create interconnects
+	#
+	ip -netns h1 li add eth0 type veth peer name r1h1
+	ip -netns h1 li set r1h1 netns r1 name eth0 up
+
+	ip -netns h1 li add eth1 type veth peer name r2h1
+	ip -netns h1 li set r2h1 netns r2 name eth0 up
+
+	ip -netns h2 li add eth0 type veth peer name r2h2
+	ip -netns h2 li set eth0 up
+	ip -netns h2 li set r2h2 netns r2 name eth2 up
+
+	ip -netns r1 li add eth1 type veth peer name r2r1
+	ip -netns r1 li set eth1 up
+	ip -netns r1 li set r2r1 netns r2 name eth1 up
+
+	#
+	# h1
+	#
+	if [ "${WITH_VRF}" = "yes" ]; then
+		create_vrf "h1"
+		H1_VRF_ARG="vrf ${VRF}"
+		H1_PING_ARG="-I ${VRF}"
+	else
+		H1_VRF_ARG=
+		H1_PING_ARG=
+	fi
+	ip -netns h1 li add br0 type bridge
+	if [ "${WITH_VRF}" = "yes" ]; then
+		ip -netns h1 li set br0 vrf ${VRF} up
+	else
+		ip -netns h1 li set br0 up
+	fi
+	ip -netns h1 addr add dev br0 ${H1_N1_IP}/24
+	ip -netns h1 -6 addr add dev br0 ${H1_N1_IP6}/64 nodad
+	ip -netns h1 li set eth0 master br0 up
+	ip -netns h1 li set eth1 master br0 up
+
+	#
+	# h2
+	#
+	ip -netns h2 addr add dev eth0 ${H2_N2_IP}/24
+	ip -netns h2 ro add default via ${R2_N2_IP} dev eth0
+	ip -netns h2 -6 addr add dev eth0 ${H2_N2_IP6}/64 nodad
+	ip -netns h2 -6 ro add default via ${R2_N2_IP6} dev eth0
+
+	#
+	# r1
+	#
+	ip -netns r1 addr add dev eth0 ${R1_N1_IP}/24
+	ip -netns r1 -6 addr add dev eth0 ${R1_N1_IP6}/64 nodad
+	ip -netns r1 addr add dev eth1 ${R1_R2_N1_IP}/30
+	ip -netns r1 -6 addr add dev eth1 ${R1_R2_N1_IP6}/126 nodad
+
+	#
+	# r2
+	#
+	ip -netns r2 addr add dev eth0 ${R2_N1_IP}/24
+	ip -netns r2 -6 addr add dev eth0 ${R2_N1_IP6}/64 nodad
+	ip -netns r2 addr add dev eth1 ${R2_R1_N1_IP}/30
+	ip -netns r2 -6 addr add dev eth1 ${R2_R1_N1_IP6}/126 nodad
+	ip -netns r2 addr add dev eth2 ${R2_N2_IP}/24
+	ip -netns r2 -6 addr add dev eth2 ${R2_N2_IP6}/64 nodad
+
+	sleep 2
+
+	R1_LLADDR=$(get_linklocal r1 eth0)
+	if [ $? -ne 0 ]; then
+		echo "Error: Failed to get link-local address of r1's eth0"
+		exit 1
+	fi
+
+	R2_LLADDR=$(get_linklocal r2 eth0)
+	if [ $? -ne 0 ]; then
+		echo "Error: Failed to get link-local address of r2's eth0"
+		exit 1
+	fi
+}
+
+change_h2_mtu()
+{
+	local mtu=$1
+
+	run_cmd ip -netns h2 li set eth0 mtu ${mtu}
+	run_cmd ip -netns r2 li set eth2 mtu ${mtu}
+}
+
+check_exception()
+{
+	local mtu="$1"
+	local with_redirect="$2"
+	local desc="$3"
+
+	# From 172.16.1.101: icmp_seq=1 Redirect Host(New nexthop: 172.16.1.102)
+	if [ "$VERBOSE" = "1" ]; then
+		echo "Commands to check for exception:"
+		run_cmd ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP}
+		run_cmd ip -netns h1 -6 ro get ${H1_VRF_ARG} ${H2_N2_IP6}
+	fi
+
+	if [ -n "${mtu}" ]; then
+		mtu=" mtu ${mtu}"
+	fi
+	if [ "$with_redirect" = "yes" ]; then
+		ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP} | \
+		grep -q "cache <redirected> expires [0-9]*sec${mtu}"
+	elif [ -n "${mtu}" ]; then
+		ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP} | \
+		grep -q "cache expires [0-9]*sec${mtu}"
+	else
+		ip -netns h1 ro get ${H1_VRF_ARG} ${H2_N2_IP} | \
+		grep -q "cache"
+	fi
+	log_test $? 0 "IPv4: ${desc}"
+
+	if [ "$with_redirect" = "yes" ]; then
+		ip -netns h1 -6 ro get ${H1_VRF_ARG} ${H2_N2_IP6} | grep -q "${H2_N2_IP6} from :: via ${R2_LLADDR} dev br0.*${mtu}"
+	else
+		ip -netns h1 -6 ro get ${H1_VRF_ARG} ${H2_N2_IP6} | grep -q "${mtu}"
+	fi
+	log_test $? 0 "IPv6: ${desc}"
+}
+
+run_ping()
+{
+	local sz=$1
+
+	run_cmd ip netns exec h1 ping -q -M want -i 0.2 -c 10 -w 2 -s ${sz} ${H1_PING_ARG} ${H2_N2_IP}
+	run_cmd ip netns exec h1 ${ping6} -q -M want -i 0.2 -c 10 -w 2 -s ${sz} ${H1_PING_ARG} ${H2_N2_IP6}
+}
+
+replace_route_legacy()
+{
+	# r1 to h2 via r2 and eth0
+	run_cmd ip -netns r1    ro replace ${H2_N2}   via ${R2_N1_IP}  dev eth0
+	run_cmd ip -netns r1 -6 ro replace ${H2_N2_6} via ${R2_LLADDR} dev eth0
+}
+
+initial_route_legacy()
+{
+	# r1 to h2 via r2 and eth1
+	run_cmd ip -netns r1    ro add ${H2_N2}   via ${R2_R1_N1_IP}  dev eth1
+	run_cmd ip -netns r1 -6 ro add ${H2_N2_6} via ${R2_R1_N1_IP6} dev eth1
+
+	# h1 to h2 via r1
+	# - IPv6 redirect only works if gateway is the LLA
+	run_cmd ip -netns h1    ro add ${H1_VRF_ARG} ${H2_N2} via ${R1_N1_IP} dev br0
+	run_cmd ip -netns h1 -6 ro add ${H1_VRF_ARG} ${H2_N2_6} via ${R1_LLADDR} dev br0
+}
+
+check_connectivity()
+{
+	local rc
+
+	run_cmd ip netns exec h1 ping -c1 -w1 ${H1_PING_ARG} ${H2_N2_IP}
+	rc=$?
+	run_cmd ip netns exec h1 ${ping6} -c1 -w1 ${H1_PING_ARG} ${H2_N2_IP6}
+	[ $? -ne 0 ] && rc=$?
+
+	return $rc
+}
+
+do_test()
+{
+	local ttype="$1"
+
+	eval initial_route_${ttype}
+
+	# verify connectivity
+	check_connectivity
+	if [ $? -ne 0 ]; then
+		echo "Error: Basic connectivity is broken"
+		ret=1
+		return
+	fi
+
+	# redirect exception followed by mtu
+	eval replace_route_${ttype}
+	run_ping 64
+	check_exception "" "yes" "redirect exception"
+
+	check_connectivity
+	if [ $? -ne 0 ]; then
+		echo "Error: Basic connectivity is broken after redirect"
+		ret=1
+		return
+	fi
+
+	change_h2_mtu 1300
+	run_ping 1350
+	check_exception "1300" "yes" "redirect exception plus mtu"
+
+	# remove exceptions and restore routing
+	change_h2_mtu 1500
+	ip -netns h1 li set br0 down
+	ip -netns h1 li set br0 up
+	eval initial_route_${ttype}
+
+	check_connectivity
+	if [ $? -ne 0 ]; then
+		echo "Error: Basic connectivity is broken after reset"
+		ret=1
+		return
+	fi
+	check_exception "" "no" "routing reset"
+
+	# MTU exception followed by redirect
+	change_h2_mtu 1300
+	run_ping 1350
+	check_exception "1300" "no" "mtu exception"
+
+	eval replace_route_${ttype}
+	run_ping 64
+	check_exception "1300" "yes" "mtu exception plus redirect"
+
+	check_connectivity
+	if [ $? -ne 0 ]; then
+		echo "Error: Basic connectivity is broken after redirect"
+		ret=1
+		return
+	fi
+}
+
+################################################################################
+# usage
+
+usage()
+{
+        cat <<EOF
+usage: ${0##*/} OPTS
+
+	-p          Pause on fail
+	-v          verbose mode (show commands and output)
+EOF
+}
+
+################################################################################
+# main
+
+# Some systems don't have a ping6 binary anymore
+which ping6 > /dev/null 2>&1 && ping6=$(which ping6) || ping6=$(which ping)
+
+ret=0
+nsuccess=0
+nfail=0
+
+while getopts :pv o
+do
+	case $o in
+                p) PAUSE_ON_FAIL=yes;;
+                v) VERBOSE=$(($VERBOSE + 1));;
+                *) usage; exit 1;;
+	esac
+done
+
+trap cleanup EXIT
+
+cleanup
+WITH_VRF=no
+setup
+
+log_section "Legacy routing"
+do_test "legacy"
+
+cleanup
+log_section "Legacy routing with VRF"
+WITH_VRF=yes
+setup
+do_test "legacy"
+
+printf "\nTests passed: %3d\n" ${nsuccess}
+printf "Tests failed: %3d\n"   ${nfail}
+
+exit $ret