Adding upstream version 5.10.209.upstream/5.10.209

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 6637 insertions, 0 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
new file mode 100644
index 000000000..b23e42efb
--- /dev/null
+++ b/net/ipv6/route.c
@@ -0,0 +1,6637 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *	Linux INET6 implementation
+ *	FIB front-end.
+ *
+ *	Authors:
+ *	Pedro Roque		<roque@di.fc.ul.pt>
+ */
+
+/*	Changes:
+ *
+ *	YOSHIFUJI Hideaki @USAGI
+ *		reworked default router selection.
+ *		- respect outgoing interface
+ *		- select from (probably) reachable routers (i.e.
+ *		routers in REACHABLE, STALE, DELAY or PROBE states).
+ *		- always select the same router if it is (probably)
+ *		reachable.  otherwise, round-robin the list.
+ *	Ville Nuorvala
+ *		Fixed routing subtrees.
+ */
+
+#define pr_fmt(fmt) "IPv6: " fmt
+
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/times.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/route.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/mroute6.h>
+#include <linux/init.h>
+#include <linux/if_arp.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/nsproxy.h>
+#include <linux/slab.h>
+#include <linux/jhash.h>
+#include <linux/siphash.h>
+#include <net/net_namespace.h>
+#include <net/snmp.h>
+#include <net/ipv6.h>
+#include <net/ip6_fib.h>
+#include <net/ip6_route.h>
+#include <net/ndisc.h>
+#include <net/addrconf.h>
+#include <net/tcp.h>
+#include <linux/rtnetlink.h>
+#include <net/dst.h>
+#include <net/dst_metadata.h>
+#include <net/xfrm.h>
+#include <net/netevent.h>
+#include <net/netlink.h>
+#include <net/rtnh.h>
+#include <net/lwtunnel.h>
+#include <net/ip_tunnels.h>
+#include <net/l3mdev.h>
+#include <net/ip.h>
+#include <linux/uaccess.h>
+#include <linux/btf_ids.h>
+
+#ifdef CONFIG_SYSCTL
+#include <linux/sysctl.h>
+#endif
+
+static int ip6_rt_type_to_error(u8 fib6_type);
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/fib6.h>
+EXPORT_TRACEPOINT_SYMBOL_GPL(fib6_table_lookup);
+#undef CREATE_TRACE_POINTS
+
+enum rt6_nud_state {
+	RT6_NUD_FAIL_HARD = -3,
+	RT6_NUD_FAIL_PROBE = -2,
+	RT6_NUD_FAIL_DO_RR = -1,
+	RT6_NUD_SUCCEED = 1
+};
+
+static struct dst_entry	*ip6_dst_check(struct dst_entry *dst, u32 cookie);
+static unsigned int	 ip6_default_advmss(const struct dst_entry *dst);
+static unsigned int	 ip6_mtu(const struct dst_entry *dst);
+static struct dst_entry *ip6_negative_advice(struct dst_entry *);
+static void		ip6_dst_destroy(struct dst_entry *);
+static void		ip6_dst_ifdown(struct dst_entry *,
+				       struct net_device *dev, int how);
+static void		 ip6_dst_gc(struct dst_ops *ops);
+
+static int		ip6_pkt_discard(struct sk_buff *skb);
+static int		ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb);
+static int		ip6_pkt_prohibit(struct sk_buff *skb);
+static int		ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb);
+static void		ip6_link_failure(struct sk_buff *skb);
+static void		ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
+					   struct sk_buff *skb, u32 mtu,
+					   bool confirm_neigh);
+static void		rt6_do_redirect(struct dst_entry *dst, struct sock *sk,
+					struct sk_buff *skb);
+static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
+			   int strict);
+static size_t rt6_nlmsg_size(struct fib6_info *f6i);
+static int rt6_fill_node(struct net *net, struct sk_buff *skb,
+			 struct fib6_info *rt, struct dst_entry *dst,
+			 struct in6_addr *dest, struct in6_addr *src,
+			 int iif, int type, u32 portid, u32 seq,
+			 unsigned int flags);
+static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
+					   const struct in6_addr *daddr,
+					   const struct in6_addr *saddr);
+
+#ifdef CONFIG_IPV6_ROUTE_INFO
+static struct fib6_info *rt6_add_route_info(struct net *net,
+					   const struct in6_addr *prefix, int prefixlen,
+					   const struct in6_addr *gwaddr,
+					   struct net_device *dev,
+					   unsigned int pref);
+static struct fib6_info *rt6_get_route_info(struct net *net,
+					   const struct in6_addr *prefix, int prefixlen,
+					   const struct in6_addr *gwaddr,
+					   struct net_device *dev);
+#endif
+
+struct uncached_list {
+	spinlock_t		lock;
+	struct list_head	head;
+};
+
+static DEFINE_PER_CPU_ALIGNED(struct uncached_list, rt6_uncached_list);
+
+void rt6_uncached_list_add(struct rt6_info *rt)
+{
+	struct uncached_list *ul = raw_cpu_ptr(&rt6_uncached_list);
+
+	rt->rt6i_uncached_list = ul;
+
+	spin_lock_bh(&ul->lock);
+	list_add_tail(&rt->rt6i_uncached, &ul->head);
+	spin_unlock_bh(&ul->lock);
+}
+
+void rt6_uncached_list_del(struct rt6_info *rt)
+{
+	if (!list_empty(&rt->rt6i_uncached)) {
+		struct uncached_list *ul = rt->rt6i_uncached_list;
+		struct net *net = dev_net(rt->dst.dev);
+
+		spin_lock_bh(&ul->lock);
+		list_del(&rt->rt6i_uncached);
+		atomic_dec(&net->ipv6.rt6_stats->fib_rt_uncache);
+		spin_unlock_bh(&ul->lock);
+	}
+}
+
+static void rt6_uncached_list_flush_dev(struct net *net, struct net_device *dev)
+{
+	struct net_device *loopback_dev = net->loopback_dev;
+	int cpu;
+
+	if (dev == loopback_dev)
+		return;
+
+	for_each_possible_cpu(cpu) {
+		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
+		struct rt6_info *rt;
+
+		spin_lock_bh(&ul->lock);
+		list_for_each_entry(rt, &ul->head, rt6i_uncached) {
+			struct inet6_dev *rt_idev = rt->rt6i_idev;
+			struct net_device *rt_dev = rt->dst.dev;
+
+			if (rt_idev->dev == dev) {
+				rt->rt6i_idev = in6_dev_get(loopback_dev);
+				in6_dev_put(rt_idev);
+			}
+
+			if (rt_dev == dev) {
+				rt->dst.dev = blackhole_netdev;
+				dev_hold(rt->dst.dev);
+				dev_put(rt_dev);
+			}
+		}
+		spin_unlock_bh(&ul->lock);
+	}
+}
+
+static inline const void *choose_neigh_daddr(const struct in6_addr *p,
+					     struct sk_buff *skb,
+					     const void *daddr)
+{
+	if (!ipv6_addr_any(p))
+		return (const void *) p;
+	else if (skb)
+		return &ipv6_hdr(skb)->daddr;
+	return daddr;
+}
+
+struct neighbour *ip6_neigh_lookup(const struct in6_addr *gw,
+				   struct net_device *dev,
+				   struct sk_buff *skb,
+				   const void *daddr)
+{
+	struct neighbour *n;
+
+	daddr = choose_neigh_daddr(gw, skb, daddr);
+	n = __ipv6_neigh_lookup(dev, daddr);
+	if (n)
+		return n;
+
+	n = neigh_create(&nd_tbl, daddr, dev);
+	return IS_ERR(n) ? NULL : n;
+}
+
+static struct neighbour *ip6_dst_neigh_lookup(const struct dst_entry *dst,
+					      struct sk_buff *skb,
+					      const void *daddr)
+{
+	const struct rt6_info *rt = container_of(dst, struct rt6_info, dst);
+
+	return ip6_neigh_lookup(rt6_nexthop(rt, &in6addr_any),
+				dst->dev, skb, daddr);
+}
+
+static void ip6_confirm_neigh(const struct dst_entry *dst, const void *daddr)
+{
+	struct net_device *dev = dst->dev;
+	struct rt6_info *rt = (struct rt6_info *)dst;
+
+	daddr = choose_neigh_daddr(rt6_nexthop(rt, &in6addr_any), NULL, daddr);
+	if (!daddr)
+		return;
+	if (dev->flags & (IFF_NOARP | IFF_LOOPBACK))
+		return;
+	if (ipv6_addr_is_multicast((const struct in6_addr *)daddr))
+		return;
+	__ipv6_confirm_neigh(dev, daddr);
+}
+
+static struct dst_ops ip6_dst_ops_template = {
+	.family			=	AF_INET6,
+	.gc			=	ip6_dst_gc,
+	.gc_thresh		=	1024,
+	.check			=	ip6_dst_check,
+	.default_advmss		=	ip6_default_advmss,
+	.mtu			=	ip6_mtu,
+	.cow_metrics		=	dst_cow_metrics_generic,
+	.destroy		=	ip6_dst_destroy,
+	.ifdown			=	ip6_dst_ifdown,
+	.negative_advice	=	ip6_negative_advice,
+	.link_failure		=	ip6_link_failure,
+	.update_pmtu		=	ip6_rt_update_pmtu,
+	.redirect		=	rt6_do_redirect,
+	.local_out		=	__ip6_local_out,
+	.neigh_lookup		=	ip6_dst_neigh_lookup,
+	.confirm_neigh		=	ip6_confirm_neigh,
+};
+
+static struct dst_ops ip6_dst_blackhole_ops = {
+	.family			= AF_INET6,
+	.default_advmss		= ip6_default_advmss,
+	.neigh_lookup		= ip6_dst_neigh_lookup,
+	.check			= ip6_dst_check,
+	.destroy		= ip6_dst_destroy,
+	.cow_metrics		= dst_cow_metrics_generic,
+	.update_pmtu		= dst_blackhole_update_pmtu,
+	.redirect		= dst_blackhole_redirect,
+	.mtu			= dst_blackhole_mtu,
+};
+
+static const u32 ip6_template_metrics[RTAX_MAX] = {
+	[RTAX_HOPLIMIT - 1] = 0,
+};
+
+static const struct fib6_info fib6_null_entry_template = {
+	.fib6_flags	= (RTF_REJECT | RTF_NONEXTHOP),
+	.fib6_protocol  = RTPROT_KERNEL,
+	.fib6_metric	= ~(u32)0,
+	.fib6_ref	= REFCOUNT_INIT(1),
+	.fib6_type	= RTN_UNREACHABLE,
+	.fib6_metrics	= (struct dst_metrics *)&dst_default_metrics,
+};
+
+static const struct rt6_info ip6_null_entry_template = {
+	.dst = {
+		.__refcnt	= ATOMIC_INIT(1),
+		.__use		= 1,
+		.obsolete	= DST_OBSOLETE_FORCE_CHK,
+		.error		= -ENETUNREACH,
+		.input		= ip6_pkt_discard,
+		.output		= ip6_pkt_discard_out,
+	},
+	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
+};
+
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+
+static const struct rt6_info ip6_prohibit_entry_template = {
+	.dst = {
+		.__refcnt	= ATOMIC_INIT(1),
+		.__use		= 1,
+		.obsolete	= DST_OBSOLETE_FORCE_CHK,
+		.error		= -EACCES,
+		.input		= ip6_pkt_prohibit,
+		.output		= ip6_pkt_prohibit_out,
+	},
+	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
+};
+
+static const struct rt6_info ip6_blk_hole_entry_template = {
+	.dst = {
+		.__refcnt	= ATOMIC_INIT(1),
+		.__use		= 1,
+		.obsolete	= DST_OBSOLETE_FORCE_CHK,
+		.error		= -EINVAL,
+		.input		= dst_discard,
+		.output		= dst_discard_out,
+	},
+	.rt6i_flags	= (RTF_REJECT | RTF_NONEXTHOP),
+};
+
+#endif
+
+static void rt6_info_init(struct rt6_info *rt)
+{
+	struct dst_entry *dst = &rt->dst;
+
+	memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
+	INIT_LIST_HEAD(&rt->rt6i_uncached);
+}
+
+/* allocate dst with ip6_dst_ops */
+struct rt6_info *ip6_dst_alloc(struct net *net, struct net_device *dev,
+			       int flags)
+{
+	struct rt6_info *rt = dst_alloc(&net->ipv6.ip6_dst_ops, dev,
+					1, DST_OBSOLETE_FORCE_CHK, flags);
+
+	if (rt) {
+		rt6_info_init(rt);
+		atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
+	}
+
+	return rt;
+}
+EXPORT_SYMBOL(ip6_dst_alloc);
+
+static void ip6_dst_destroy(struct dst_entry *dst)
+{
+	struct rt6_info *rt = (struct rt6_info *)dst;
+	struct fib6_info *from;
+	struct inet6_dev *idev;
+
+	ip_dst_metrics_put(dst);
+	rt6_uncached_list_del(rt);
+
+	idev = rt->rt6i_idev;
+	if (idev) {
+		rt->rt6i_idev = NULL;
+		in6_dev_put(idev);
+	}
+
+	from = xchg((__force struct fib6_info **)&rt->from, NULL);
+	fib6_info_release(from);
+}
+
+static void ip6_dst_ifdown(struct dst_entry *dst, struct net_device *dev,
+			   int how)
+{
+	struct rt6_info *rt = (struct rt6_info *)dst;
+	struct inet6_dev *idev = rt->rt6i_idev;
+	struct net_device *loopback_dev =
+		dev_net(dev)->loopback_dev;
+
+	if (idev && idev->dev != loopback_dev) {
+		struct inet6_dev *loopback_idev = in6_dev_get(loopback_dev);
+		if (loopback_idev) {
+			rt->rt6i_idev = loopback_idev;
+			in6_dev_put(idev);
+		}
+	}
+}
+
+static bool __rt6_check_expired(const struct rt6_info *rt)
+{
+	if (rt->rt6i_flags & RTF_EXPIRES)
+		return time_after(jiffies, rt->dst.expires);
+	else
+		return false;
+}
+
+static bool rt6_check_expired(const struct rt6_info *rt)
+{
+	struct fib6_info *from;
+
+	from = rcu_dereference(rt->from);
+
+	if (rt->rt6i_flags & RTF_EXPIRES) {
+		if (time_after(jiffies, rt->dst.expires))
+			return true;
+	} else if (from) {
+		return rt->dst.obsolete != DST_OBSOLETE_FORCE_CHK ||
+			fib6_check_expired(from);
+	}
+	return false;
+}
+
+void fib6_select_path(const struct net *net, struct fib6_result *res,
+		      struct flowi6 *fl6, int oif, bool have_oif_match,
+		      const struct sk_buff *skb, int strict)
+{
+	struct fib6_info *sibling, *next_sibling;
+	struct fib6_info *match = res->f6i;
+
+	if (!match->nh && (!match->fib6_nsiblings || have_oif_match))
+		goto out;
+
+	if (match->nh && have_oif_match && res->nh)
+		return;
+
+	/* We might have already computed the hash for ICMPv6 errors. In such
+	 * case it will always be non-zero. Otherwise now is the time to do it.
+	 */
+	if (!fl6->mp_hash &&
+	    (!match->nh || nexthop_is_multipath(match->nh)))
+		fl6->mp_hash = rt6_multipath_hash(net, fl6, skb, NULL);
+
+	if (unlikely(match->nh)) {
+		nexthop_path_fib6_result(res, fl6->mp_hash);
+		return;
+	}
+
+	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;
+		int nh_upper_bound;
+
+		nh_upper_bound = atomic_read(&nh->fib_nh_upper_bound);
+		if (fl6->mp_hash > nh_upper_bound)
+			continue;
+		if (rt6_score_route(nh, sibling->fib6_flags, oif, strict) < 0)
+			break;
+		match = sibling;
+		break;
+	}
+
+out:
+	res->f6i = match;
+	res->nh = match->fib6_nh;
+}
+
+/*
+ *	Route lookup. rcu_read_lock() should be held.
+ */
+
+static bool __rt6_device_match(struct net *net, const struct fib6_nh *nh,
+			       const struct in6_addr *saddr, int oif, int flags)
+{
+	const struct net_device *dev;
+
+	if (nh->fib_nh_flags & RTNH_F_DEAD)
+		return false;
+
+	dev = nh->fib_nh_dev;
+	if (oif) {
+		if (dev->ifindex == oif)
+			return true;
+	} else {
+		if (ipv6_chk_addr(net, saddr, dev,
+				  flags & RT6_LOOKUP_F_IFACE))
+			return true;
+	}
+
+	return false;
+}
+
+struct fib6_nh_dm_arg {
+	struct net		*net;
+	const struct in6_addr	*saddr;
+	int			oif;
+	int			flags;
+	struct fib6_nh		*nh;
+};
+
+static int __rt6_nh_dev_match(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_dm_arg *arg = _arg;
+
+	arg->nh = nh;
+	return __rt6_device_match(arg->net, nh, arg->saddr, arg->oif,
+				  arg->flags);
+}
+
+/* returns fib6_nh from nexthop or NULL */
+static struct fib6_nh *rt6_nh_dev_match(struct net *net, struct nexthop *nh,
+					struct fib6_result *res,
+					const struct in6_addr *saddr,
+					int oif, int flags)
+{
+	struct fib6_nh_dm_arg arg = {
+		.net   = net,
+		.saddr = saddr,
+		.oif   = oif,
+		.flags = flags,
+	};
+
+	if (nexthop_is_blackhole(nh))
+		return NULL;
+
+	if (nexthop_for_each_fib6_nh(nh, __rt6_nh_dev_match, &arg))
+		return arg.nh;
+
+	return NULL;
+}
+
+static void rt6_device_match(struct net *net, struct fib6_result *res,
+			     const struct in6_addr *saddr, int oif, int flags)
+{
+	struct fib6_info *f6i = res->f6i;
+	struct fib6_info *spf6i;
+	struct fib6_nh *nh;
+
+	if (!oif && ipv6_addr_any(saddr)) {
+		if (unlikely(f6i->nh)) {
+			nh = nexthop_fib6_nh(f6i->nh);
+			if (nexthop_is_blackhole(f6i->nh))
+				goto out_blackhole;
+		} else {
+			nh = f6i->fib6_nh;
+		}
+		if (!(nh->fib_nh_flags & RTNH_F_DEAD))
+			goto out;
+	}
+
+	for (spf6i = f6i; spf6i; spf6i = rcu_dereference(spf6i->fib6_next)) {
+		bool matched = false;
+
+		if (unlikely(spf6i->nh)) {
+			nh = rt6_nh_dev_match(net, spf6i->nh, res, saddr,
+					      oif, flags);
+			if (nh)
+				matched = true;
+		} else {
+			nh = spf6i->fib6_nh;
+			if (__rt6_device_match(net, nh, saddr, oif, flags))
+				matched = true;
+		}
+		if (matched) {
+			res->f6i = spf6i;
+			goto out;
+		}
+	}
+
+	if (oif && flags & RT6_LOOKUP_F_IFACE) {
+		res->f6i = net->ipv6.fib6_null_entry;
+		nh = res->f6i->fib6_nh;
+		goto out;
+	}
+
+	if (unlikely(f6i->nh)) {
+		nh = nexthop_fib6_nh(f6i->nh);
+		if (nexthop_is_blackhole(f6i->nh))
+			goto out_blackhole;
+	} else {
+		nh = f6i->fib6_nh;
+	}
+
+	if (nh->fib_nh_flags & RTNH_F_DEAD) {
+		res->f6i = net->ipv6.fib6_null_entry;
+		nh = res->f6i->fib6_nh;
+	}
+out:
+	res->nh = nh;
+	res->fib6_type = res->f6i->fib6_type;
+	res->fib6_flags = res->f6i->fib6_flags;
+	return;
+
+out_blackhole:
+	res->fib6_flags |= RTF_REJECT;
+	res->fib6_type = RTN_BLACKHOLE;
+	res->nh = nh;
+}
+
+#ifdef CONFIG_IPV6_ROUTER_PREF
+struct __rt6_probe_work {
+	struct work_struct work;
+	struct in6_addr target;
+	struct net_device *dev;
+};
+
+static void rt6_probe_deferred(struct work_struct *w)
+{
+	struct in6_addr mcaddr;
+	struct __rt6_probe_work *work =
+		container_of(w, struct __rt6_probe_work, work);
+
+	addrconf_addr_solict_mult(&work->target, &mcaddr);
+	ndisc_send_ns(work->dev, &work->target, &mcaddr, NULL, 0);
+	dev_put(work->dev);
+	kfree(work);
+}
+
+static void rt6_probe(struct fib6_nh *fib6_nh)
+{
+	struct __rt6_probe_work *work = NULL;
+	const struct in6_addr *nh_gw;
+	unsigned long last_probe;
+	struct neighbour *neigh;
+	struct net_device *dev;
+	struct inet6_dev *idev;
+
+	/*
+	 * Okay, this does not seem to be appropriate
+	 * for now, however, we need to check if it
+	 * is really so; aka Router Reachability Probing.
+	 *
+	 * Router Reachability Probe MUST be rate-limited
+	 * to no more than one per minute.
+	 */
+	if (!fib6_nh->fib_nh_gw_family)
+		return;
+
+	nh_gw = &fib6_nh->fib_nh_gw6;
+	dev = fib6_nh->fib_nh_dev;
+	rcu_read_lock_bh();
+	last_probe = READ_ONCE(fib6_nh->last_probe);
+	idev = __in6_dev_get(dev);
+	neigh = __ipv6_neigh_lookup_noref(dev, nh_gw);
+	if (neigh) {
+		if (neigh->nud_state & NUD_VALID)
+			goto out;
+
+		write_lock(&neigh->lock);
+		if (!(neigh->nud_state & NUD_VALID) &&
+		    time_after(jiffies,
+			       neigh->updated + idev->cnf.rtr_probe_interval)) {
+			work = kmalloc(sizeof(*work), GFP_ATOMIC);
+			if (work)
+				__neigh_set_probe_once(neigh);
+		}
+		write_unlock(&neigh->lock);
+	} else if (time_after(jiffies, last_probe +
+				       idev->cnf.rtr_probe_interval)) {
+		work = kmalloc(sizeof(*work), GFP_ATOMIC);
+	}
+
+	if (!work || cmpxchg(&fib6_nh->last_probe,
+			     last_probe, jiffies) != last_probe) {
+		kfree(work);
+	} else {
+		INIT_WORK(&work->work, rt6_probe_deferred);
+		work->target = *nh_gw;
+		dev_hold(dev);
+		work->dev = dev;
+		schedule_work(&work->work);
+	}
+
+out:
+	rcu_read_unlock_bh();
+}
+#else
+static inline void rt6_probe(struct fib6_nh *fib6_nh)
+{
+}
+#endif
+
+/*
+ * Default Router Selection (RFC 2461 6.3.6)
+ */
+static enum rt6_nud_state rt6_check_neigh(const struct fib6_nh *fib6_nh)
+{
+	enum rt6_nud_state ret = RT6_NUD_FAIL_HARD;
+	struct neighbour *neigh;
+
+	rcu_read_lock_bh();
+	neigh = __ipv6_neigh_lookup_noref(fib6_nh->fib_nh_dev,
+					  &fib6_nh->fib_nh_gw6);
+	if (neigh) {
+		read_lock(&neigh->lock);
+		if (neigh->nud_state & NUD_VALID)
+			ret = RT6_NUD_SUCCEED;
+#ifdef CONFIG_IPV6_ROUTER_PREF
+		else if (!(neigh->nud_state & NUD_FAILED))
+			ret = RT6_NUD_SUCCEED;
+		else
+			ret = RT6_NUD_FAIL_PROBE;
+#endif
+		read_unlock(&neigh->lock);
+	} else {
+		ret = IS_ENABLED(CONFIG_IPV6_ROUTER_PREF) ?
+		      RT6_NUD_SUCCEED : RT6_NUD_FAIL_DO_RR;
+	}
+	rcu_read_unlock_bh();
+
+	return ret;
+}
+
+static int rt6_score_route(const struct fib6_nh *nh, u32 fib6_flags, int oif,
+			   int strict)
+{
+	int m = 0;
+
+	if (!oif || nh->fib_nh_dev->ifindex == oif)
+		m = 2;
+
+	if (!m && (strict & RT6_LOOKUP_F_IFACE))
+		return RT6_NUD_FAIL_HARD;
+#ifdef CONFIG_IPV6_ROUTER_PREF
+	m |= IPV6_DECODE_PREF(IPV6_EXTRACT_PREF(fib6_flags)) << 2;
+#endif
+	if ((strict & RT6_LOOKUP_F_REACHABLE) &&
+	    !(fib6_flags & RTF_NONEXTHOP) && nh->fib_nh_gw_family) {
+		int n = rt6_check_neigh(nh);
+		if (n < 0)
+			return n;
+	}
+	return m;
+}
+
+static bool find_match(struct fib6_nh *nh, u32 fib6_flags,
+		       int oif, int strict, int *mpri, bool *do_rr)
+{
+	bool match_do_rr = false;
+	bool rc = false;
+	int m;
+
+	if (nh->fib_nh_flags & RTNH_F_DEAD)
+		goto out;
+
+	if (ip6_ignore_linkdown(nh->fib_nh_dev) &&
+	    nh->fib_nh_flags & RTNH_F_LINKDOWN &&
+	    !(strict & RT6_LOOKUP_F_IGNORE_LINKSTATE))
+		goto out;
+
+	m = rt6_score_route(nh, fib6_flags, oif, strict);
+	if (m == RT6_NUD_FAIL_DO_RR) {
+		match_do_rr = true;
+		m = 0; /* lowest valid score */
+	} else if (m == RT6_NUD_FAIL_HARD) {
+		goto out;
+	}
+
+	if (strict & RT6_LOOKUP_F_REACHABLE)
+		rt6_probe(nh);
+
+	/* note that m can be RT6_NUD_FAIL_PROBE at this point */
+	if (m > *mpri) {
+		*do_rr = match_do_rr;
+		*mpri = m;
+		rc = true;
+	}
+out:
+	return rc;
+}
+
+struct fib6_nh_frl_arg {
+	u32		flags;
+	int		oif;
+	int		strict;
+	int		*mpri;
+	bool		*do_rr;
+	struct fib6_nh	*nh;
+};
+
+static int rt6_nh_find_match(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_frl_arg *arg = _arg;
+
+	arg->nh = nh;
+	return find_match(nh, arg->flags, arg->oif, arg->strict,
+			  arg->mpri, arg->do_rr);
+}
+
+static void __find_rr_leaf(struct fib6_info *f6i_start,
+			   struct fib6_info *nomatch, u32 metric,
+			   struct fib6_result *res, struct fib6_info **cont,
+			   int oif, int strict, bool *do_rr, int *mpri)
+{
+	struct fib6_info *f6i;
+
+	for (f6i = f6i_start;
+	     f6i && f6i != nomatch;
+	     f6i = rcu_dereference(f6i->fib6_next)) {
+		bool matched = false;
+		struct fib6_nh *nh;
+
+		if (cont && f6i->fib6_metric != metric) {
+			*cont = f6i;
+			return;
+		}
+
+		if (fib6_check_expired(f6i))
+			continue;
+
+		if (unlikely(f6i->nh)) {
+			struct fib6_nh_frl_arg arg = {
+				.flags  = f6i->fib6_flags,
+				.oif    = oif,
+				.strict = strict,
+				.mpri   = mpri,
+				.do_rr  = do_rr
+			};
+
+			if (nexthop_is_blackhole(f6i->nh)) {
+				res->fib6_flags = RTF_REJECT;
+				res->fib6_type = RTN_BLACKHOLE;
+				res->f6i = f6i;
+				res->nh = nexthop_fib6_nh(f6i->nh);
+				return;
+			}
+			if (nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_find_match,
+						     &arg)) {
+				matched = true;
+				nh = arg.nh;
+			}
+		} else {
+			nh = f6i->fib6_nh;
+			if (find_match(nh, f6i->fib6_flags, oif, strict,
+				       mpri, do_rr))
+				matched = true;
+		}
+		if (matched) {
+			res->f6i = f6i;
+			res->nh = nh;
+			res->fib6_flags = f6i->fib6_flags;
+			res->fib6_type = f6i->fib6_type;
+		}
+	}
+}
+
+static void find_rr_leaf(struct fib6_node *fn, struct fib6_info *leaf,
+			 struct fib6_info *rr_head, int oif, int strict,
+			 bool *do_rr, struct fib6_result *res)
+{
+	u32 metric = rr_head->fib6_metric;
+	struct fib6_info *cont = NULL;
+	int mpri = -1;
+
+	__find_rr_leaf(rr_head, NULL, metric, res, &cont,
+		       oif, strict, do_rr, &mpri);
+
+	__find_rr_leaf(leaf, rr_head, metric, res, &cont,
+		       oif, strict, do_rr, &mpri);
+
+	if (res->f6i || !cont)
+		return;
+
+	__find_rr_leaf(cont, NULL, metric, res, NULL,
+		       oif, strict, do_rr, &mpri);
+}
+
+static void rt6_select(struct net *net, struct fib6_node *fn, int oif,
+		       struct fib6_result *res, int strict)
+{
+	struct fib6_info *leaf = rcu_dereference(fn->leaf);
+	struct fib6_info *rt0;
+	bool do_rr = false;
+	int key_plen;
+
+	/* make sure this function or its helpers sets f6i */
+	res->f6i = NULL;
+
+	if (!leaf || leaf == net->ipv6.fib6_null_entry)
+		goto out;
+
+	rt0 = rcu_dereference(fn->rr_ptr);
+	if (!rt0)
+		rt0 = leaf;
+
+	/* Double check to make sure fn is not an intermediate node
+	 * and fn->leaf does not points to its child's leaf
+	 * (This might happen if all routes under fn are deleted from
+	 * the tree and fib6_repair_tree() is called on the node.)
+	 */
+	key_plen = rt0->fib6_dst.plen;
+#ifdef CONFIG_IPV6_SUBTREES
+	if (rt0->fib6_src.plen)
+		key_plen = rt0->fib6_src.plen;
+#endif
+	if (fn->fn_bit != key_plen)
+		goto out;
+
+	find_rr_leaf(fn, leaf, rt0, oif, strict, &do_rr, res);
+	if (do_rr) {
+		struct fib6_info *next = rcu_dereference(rt0->fib6_next);
+
+		/* no entries matched; do round-robin */
+		if (!next || next->fib6_metric != rt0->fib6_metric)
+			next = leaf;
+
+		if (next != rt0) {
+			spin_lock_bh(&leaf->fib6_table->tb6_lock);
+			/* make sure next is not being deleted from the tree */
+			if (next->fib6_node)
+				rcu_assign_pointer(fn->rr_ptr, next);
+			spin_unlock_bh(&leaf->fib6_table->tb6_lock);
+		}
+	}
+
+out:
+	if (!res->f6i) {
+		res->f6i = net->ipv6.fib6_null_entry;
+		res->nh = res->f6i->fib6_nh;
+		res->fib6_flags = res->f6i->fib6_flags;
+		res->fib6_type = res->f6i->fib6_type;
+	}
+}
+
+static bool rt6_is_gw_or_nonexthop(const struct fib6_result *res)
+{
+	return (res->f6i->fib6_flags & RTF_NONEXTHOP) ||
+	       res->nh->fib_nh_gw_family;
+}
+
+#ifdef CONFIG_IPV6_ROUTE_INFO
+int rt6_route_rcv(struct net_device *dev, u8 *opt, int len,
+		  const struct in6_addr *gwaddr)
+{
+	struct net *net = dev_net(dev);
+	struct route_info *rinfo = (struct route_info *) opt;
+	struct in6_addr prefix_buf, *prefix;
+	unsigned int pref;
+	unsigned long lifetime;
+	struct fib6_info *rt;
+
+	if (len < sizeof(struct route_info)) {
+		return -EINVAL;
+	}
+
+	/* Sanity check for prefix_len and length */
+	if (rinfo->length > 3) {
+		return -EINVAL;
+	} else if (rinfo->prefix_len > 128) {
+		return -EINVAL;
+	} else if (rinfo->prefix_len > 64) {
+		if (rinfo->length < 2) {
+			return -EINVAL;
+		}
+	} else if (rinfo->prefix_len > 0) {
+		if (rinfo->length < 1) {
+			return -EINVAL;
+		}
+	}
+
+	pref = rinfo->route_pref;
+	if (pref == ICMPV6_ROUTER_PREF_INVALID)
+		return -EINVAL;
+
+	lifetime = addrconf_timeout_fixup(ntohl(rinfo->lifetime), HZ);
+
+	if (rinfo->length == 3)
+		prefix = (struct in6_addr *)rinfo->prefix;
+	else {
+		/* this function is safe */
+		ipv6_addr_prefix(&prefix_buf,
+				 (struct in6_addr *)rinfo->prefix,
+				 rinfo->prefix_len);
+		prefix = &prefix_buf;
+	}
+
+	if (rinfo->prefix_len == 0)
+		rt = rt6_get_dflt_router(net, gwaddr, dev);
+	else
+		rt = rt6_get_route_info(net, prefix, rinfo->prefix_len,
+					gwaddr, dev);
+
+	if (rt && !lifetime) {
+		ip6_del_rt(net, rt, false);
+		rt = NULL;
+	}
+
+	if (!rt && lifetime)
+		rt = rt6_add_route_info(net, prefix, rinfo->prefix_len, gwaddr,
+					dev, pref);
+	else if (rt)
+		rt->fib6_flags = RTF_ROUTEINFO |
+				 (rt->fib6_flags & ~RTF_PREF_MASK) | RTF_PREF(pref);
+
+	if (rt) {
+		if (!addrconf_finite_timeout(lifetime))
+			fib6_clean_expires(rt);
+		else
+			fib6_set_expires(rt, jiffies + HZ * lifetime);
+
+		fib6_info_release(rt);
+	}
+	return 0;
+}
+#endif
+
+/*
+ *	Misc support functions
+ */
+
+/* called with rcu_lock held */
+static struct net_device *ip6_rt_get_dev_rcu(const struct fib6_result *res)
+{
+	struct net_device *dev = res->nh->fib_nh_dev;
+
+	if (res->fib6_flags & (RTF_LOCAL | RTF_ANYCAST)) {
+		/* for copies of local routes, dst->dev needs to be the
+		 * device if it is a master device, the master device if
+		 * device is enslaved, and the loopback as the default
+		 */
+		if (netif_is_l3_slave(dev) &&
+		    !rt6_need_strict(&res->f6i->fib6_dst.addr))
+			dev = l3mdev_master_dev_rcu(dev);
+		else if (!netif_is_l3_master(dev))
+			dev = dev_net(dev)->loopback_dev;
+		/* last case is netif_is_l3_master(dev) is true in which
+		 * case we want dev returned to be dev
+		 */
+	}
+
+	return dev;
+}
+
+static const int fib6_prop[RTN_MAX + 1] = {
+	[RTN_UNSPEC]	= 0,
+	[RTN_UNICAST]	= 0,
+	[RTN_LOCAL]	= 0,
+	[RTN_BROADCAST]	= 0,
+	[RTN_ANYCAST]	= 0,
+	[RTN_MULTICAST]	= 0,
+	[RTN_BLACKHOLE]	= -EINVAL,
+	[RTN_UNREACHABLE] = -EHOSTUNREACH,
+	[RTN_PROHIBIT]	= -EACCES,
+	[RTN_THROW]	= -EAGAIN,
+	[RTN_NAT]	= -EINVAL,
+	[RTN_XRESOLVE]	= -EINVAL,
+};
+
+static int ip6_rt_type_to_error(u8 fib6_type)
+{
+	return fib6_prop[fib6_type];
+}
+
+static unsigned short fib6_info_dst_flags(struct fib6_info *rt)
+{
+	unsigned short flags = 0;
+
+	if (rt->dst_nocount)
+		flags |= DST_NOCOUNT;
+	if (rt->dst_nopolicy)
+		flags |= DST_NOPOLICY;
+
+	return flags;
+}
+
+static void ip6_rt_init_dst_reject(struct rt6_info *rt, u8 fib6_type)
+{
+	rt->dst.error = ip6_rt_type_to_error(fib6_type);
+
+	switch (fib6_type) {
+	case RTN_BLACKHOLE:
+		rt->dst.output = dst_discard_out;
+		rt->dst.input = dst_discard;
+		break;
+	case RTN_PROHIBIT:
+		rt->dst.output = ip6_pkt_prohibit_out;
+		rt->dst.input = ip6_pkt_prohibit;
+		break;
+	case RTN_THROW:
+	case RTN_UNREACHABLE:
+	default:
+		rt->dst.output = ip6_pkt_discard_out;
+		rt->dst.input = ip6_pkt_discard;
+		break;
+	}
+}
+
+static void ip6_rt_init_dst(struct rt6_info *rt, const struct fib6_result *res)
+{
+	struct fib6_info *f6i = res->f6i;
+
+	if (res->fib6_flags & RTF_REJECT) {
+		ip6_rt_init_dst_reject(rt, res->fib6_type);
+		return;
+	}
+
+	rt->dst.error = 0;
+	rt->dst.output = ip6_output;
+
+	if (res->fib6_type == RTN_LOCAL || res->fib6_type == RTN_ANYCAST) {
+		rt->dst.input = ip6_input;
+	} else if (ipv6_addr_type(&f6i->fib6_dst.addr) & IPV6_ADDR_MULTICAST) {
+		rt->dst.input = ip6_mc_input;
+	} else {
+		rt->dst.input = ip6_forward;
+	}
+
+	if (res->nh->fib_nh_lws) {
+		rt->dst.lwtstate = lwtstate_get(res->nh->fib_nh_lws);
+		lwtunnel_set_redirect(&rt->dst);
+	}
+
+	rt->dst.lastuse = jiffies;
+}
+
+/* Caller must already hold reference to @from */
+static void rt6_set_from(struct rt6_info *rt, struct fib6_info *from)
+{
+	rt->rt6i_flags &= ~RTF_EXPIRES;
+	rcu_assign_pointer(rt->from, from);
+	ip_dst_init_metrics(&rt->dst, from->fib6_metrics);
+}
+
+/* Caller must already hold reference to f6i in result */
+static void ip6_rt_copy_init(struct rt6_info *rt, const struct fib6_result *res)
+{
+	const struct fib6_nh *nh = res->nh;
+	const struct net_device *dev = nh->fib_nh_dev;
+	struct fib6_info *f6i = res->f6i;
+
+	ip6_rt_init_dst(rt, res);
+
+	rt->rt6i_dst = f6i->fib6_dst;
+	rt->rt6i_idev = dev ? in6_dev_get(dev) : NULL;
+	rt->rt6i_flags = res->fib6_flags;
+	if (nh->fib_nh_gw_family) {
+		rt->rt6i_gateway = nh->fib_nh_gw6;
+		rt->rt6i_flags |= RTF_GATEWAY;
+	}
+	rt6_set_from(rt, f6i);
+#ifdef CONFIG_IPV6_SUBTREES
+	rt->rt6i_src = f6i->fib6_src;
+#endif
+}
+
+static struct fib6_node* fib6_backtrack(struct fib6_node *fn,
+					struct in6_addr *saddr)
+{
+	struct fib6_node *pn, *sn;
+	while (1) {
+		if (fn->fn_flags & RTN_TL_ROOT)
+			return NULL;
+		pn = rcu_dereference(fn->parent);
+		sn = FIB6_SUBTREE(pn);
+		if (sn && sn != fn)
+			fn = fib6_node_lookup(sn, NULL, saddr);
+		else
+			fn = pn;
+		if (fn->fn_flags & RTN_RTINFO)
+			return fn;
+	}
+}
+
+static bool ip6_hold_safe(struct net *net, struct rt6_info **prt)
+{
+	struct rt6_info *rt = *prt;
+
+	if (dst_hold_safe(&rt->dst))
+		return true;
+	if (net) {
+		rt = net->ipv6.ip6_null_entry;
+		dst_hold(&rt->dst);
+	} else {
+		rt = NULL;
+	}
+	*prt = rt;
+	return false;
+}
+
+/* called with rcu_lock held */
+static struct rt6_info *ip6_create_rt_rcu(const struct fib6_result *res)
+{
+	struct net_device *dev = res->nh->fib_nh_dev;
+	struct fib6_info *f6i = res->f6i;
+	unsigned short flags;
+	struct rt6_info *nrt;
+
+	if (!fib6_info_hold_safe(f6i))
+		goto fallback;
+
+	flags = fib6_info_dst_flags(f6i);
+	nrt = ip6_dst_alloc(dev_net(dev), dev, flags);
+	if (!nrt) {
+		fib6_info_release(f6i);
+		goto fallback;
+	}
+
+	ip6_rt_copy_init(nrt, res);
+	return nrt;
+
+fallback:
+	nrt = dev_net(dev)->ipv6.ip6_null_entry;
+	dst_hold(&nrt->dst);
+	return nrt;
+}
+
+INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_lookup(struct net *net,
+					     struct fib6_table *table,
+					     struct flowi6 *fl6,
+					     const struct sk_buff *skb,
+					     int flags)
+{
+	struct fib6_result res = {};
+	struct fib6_node *fn;
+	struct rt6_info *rt;
+
+	if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
+		flags &= ~RT6_LOOKUP_F_IFACE;
+
+	rcu_read_lock();
+	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
+restart:
+	res.f6i = rcu_dereference(fn->leaf);
+	if (!res.f6i)
+		res.f6i = net->ipv6.fib6_null_entry;
+	else
+		rt6_device_match(net, &res, &fl6->saddr, fl6->flowi6_oif,
+				 flags);
+
+	if (res.f6i == net->ipv6.fib6_null_entry) {
+		fn = fib6_backtrack(fn, &fl6->saddr);
+		if (fn)
+			goto restart;
+
+		rt = net->ipv6.ip6_null_entry;
+		dst_hold(&rt->dst);
+		goto out;
+	} else if (res.fib6_flags & RTF_REJECT) {
+		goto do_create;
+	}
+
+	fib6_select_path(net, &res, fl6, fl6->flowi6_oif,
+			 fl6->flowi6_oif != 0, skb, flags);
+
+	/* Search through exception table */
+	rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
+	if (rt) {
+		if (ip6_hold_safe(net, &rt))
+			dst_use_noref(&rt->dst, jiffies);
+	} else {
+do_create:
+		rt = ip6_create_rt_rcu(&res);
+	}
+
+out:
+	trace_fib6_table_lookup(net, &res, table, fl6);
+
+	rcu_read_unlock();
+
+	return rt;
+}
+
+struct dst_entry *ip6_route_lookup(struct net *net, struct flowi6 *fl6,
+				   const struct sk_buff *skb, int flags)
+{
+	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_lookup);
+}
+EXPORT_SYMBOL_GPL(ip6_route_lookup);
+
+struct rt6_info *rt6_lookup(struct net *net, const struct in6_addr *daddr,
+			    const struct in6_addr *saddr, int oif,
+			    const struct sk_buff *skb, int strict)
+{
+	struct flowi6 fl6 = {
+		.flowi6_oif = oif,
+		.daddr = *daddr,
+	};
+	struct dst_entry *dst;
+	int flags = strict ? RT6_LOOKUP_F_IFACE : 0;
+
+	if (saddr) {
+		memcpy(&fl6.saddr, saddr, sizeof(*saddr));
+		flags |= RT6_LOOKUP_F_HAS_SADDR;
+	}
+
+	dst = fib6_rule_lookup(net, &fl6, skb, flags, ip6_pol_route_lookup);
+	if (dst->error == 0)
+		return (struct rt6_info *) dst;
+
+	dst_release(dst);
+
+	return NULL;
+}
+EXPORT_SYMBOL(rt6_lookup);
+
+/* ip6_ins_rt is called with FREE table->tb6_lock.
+ * It takes new route entry, the addition fails by any reason the
+ * route is released.
+ * Caller must hold dst before calling it.
+ */
+
+static int __ip6_ins_rt(struct fib6_info *rt, struct nl_info *info,
+			struct netlink_ext_ack *extack)
+{
+	int err;
+	struct fib6_table *table;
+
+	table = rt->fib6_table;
+	spin_lock_bh(&table->tb6_lock);
+	err = fib6_add(&table->tb6_root, rt, info, extack);
+	spin_unlock_bh(&table->tb6_lock);
+
+	return err;
+}
+
+int ip6_ins_rt(struct net *net, struct fib6_info *rt)
+{
+	struct nl_info info = {	.nl_net = net, };
+
+	return __ip6_ins_rt(rt, &info, NULL);
+}
+
+static struct rt6_info *ip6_rt_cache_alloc(const struct fib6_result *res,
+					   const struct in6_addr *daddr,
+					   const struct in6_addr *saddr)
+{
+	struct fib6_info *f6i = res->f6i;
+	struct net_device *dev;
+	struct rt6_info *rt;
+
+	/*
+	 *	Clone the route.
+	 */
+
+	if (!fib6_info_hold_safe(f6i))
+		return NULL;
+
+	dev = ip6_rt_get_dev_rcu(res);
+	rt = ip6_dst_alloc(dev_net(dev), dev, 0);
+	if (!rt) {
+		fib6_info_release(f6i);
+		return NULL;
+	}
+
+	ip6_rt_copy_init(rt, res);
+	rt->rt6i_flags |= RTF_CACHE;
+	rt->rt6i_dst.addr = *daddr;
+	rt->rt6i_dst.plen = 128;
+
+	if (!rt6_is_gw_or_nonexthop(res)) {
+		if (f6i->fib6_dst.plen != 128 &&
+		    ipv6_addr_equal(&f6i->fib6_dst.addr, daddr))
+			rt->rt6i_flags |= RTF_ANYCAST;
+#ifdef CONFIG_IPV6_SUBTREES
+		if (rt->rt6i_src.plen && saddr) {
+			rt->rt6i_src.addr = *saddr;
+			rt->rt6i_src.plen = 128;
+		}
+#endif
+	}
+
+	return rt;
+}
+
+static struct rt6_info *ip6_rt_pcpu_alloc(const struct fib6_result *res)
+{
+	struct fib6_info *f6i = res->f6i;
+	unsigned short flags = fib6_info_dst_flags(f6i);
+	struct net_device *dev;
+	struct rt6_info *pcpu_rt;
+
+	if (!fib6_info_hold_safe(f6i))
+		return NULL;
+
+	rcu_read_lock();
+	dev = ip6_rt_get_dev_rcu(res);
+	pcpu_rt = ip6_dst_alloc(dev_net(dev), dev, flags | DST_NOCOUNT);
+	rcu_read_unlock();
+	if (!pcpu_rt) {
+		fib6_info_release(f6i);
+		return NULL;
+	}
+	ip6_rt_copy_init(pcpu_rt, res);
+	pcpu_rt->rt6i_flags |= RTF_PCPU;
+
+	if (f6i->nh)
+		pcpu_rt->sernum = rt_genid_ipv6(dev_net(dev));
+
+	return pcpu_rt;
+}
+
+static bool rt6_is_valid(const struct rt6_info *rt6)
+{
+	return rt6->sernum == rt_genid_ipv6(dev_net(rt6->dst.dev));
+}
+
+/* It should be called with rcu_read_lock() acquired */
+static struct rt6_info *rt6_get_pcpu_route(const struct fib6_result *res)
+{
+	struct rt6_info *pcpu_rt;
+
+	pcpu_rt = this_cpu_read(*res->nh->rt6i_pcpu);
+
+	if (pcpu_rt && pcpu_rt->sernum && !rt6_is_valid(pcpu_rt)) {
+		struct rt6_info *prev, **p;
+
+		p = this_cpu_ptr(res->nh->rt6i_pcpu);
+		prev = xchg(p, NULL);
+		if (prev) {
+			dst_dev_put(&prev->dst);
+			dst_release(&prev->dst);
+		}
+
+		pcpu_rt = NULL;
+	}
+
+	return pcpu_rt;
+}
+
+static struct rt6_info *rt6_make_pcpu_route(struct net *net,
+					    const struct fib6_result *res)
+{
+	struct rt6_info *pcpu_rt, *prev, **p;
+
+	pcpu_rt = ip6_rt_pcpu_alloc(res);
+	if (!pcpu_rt)
+		return NULL;
+
+	p = this_cpu_ptr(res->nh->rt6i_pcpu);
+	prev = cmpxchg(p, NULL, pcpu_rt);
+	BUG_ON(prev);
+
+	if (res->f6i->fib6_destroying) {
+		struct fib6_info *from;
+
+		from = xchg((__force struct fib6_info **)&pcpu_rt->from, NULL);
+		fib6_info_release(from);
+	}
+
+	return pcpu_rt;
+}
+
+/* exception hash table implementation
+ */
+static DEFINE_SPINLOCK(rt6_exception_lock);
+
+/* Remove rt6_ex from hash table and free the memory
+ * Caller must hold rt6_exception_lock
+ */
+static void rt6_remove_exception(struct rt6_exception_bucket *bucket,
+				 struct rt6_exception *rt6_ex)
+{
+	struct fib6_info *from;
+	struct net *net;
+
+	if (!bucket || !rt6_ex)
+		return;
+
+	net = dev_net(rt6_ex->rt6i->dst.dev);
+	net->ipv6.rt6_stats->fib_rt_cache--;
+
+	/* purge completely the exception to allow releasing the held resources:
+	 * some [sk] cache may keep the dst around for unlimited time
+	 */
+	from = xchg((__force struct fib6_info **)&rt6_ex->rt6i->from, NULL);
+	fib6_info_release(from);
+	dst_dev_put(&rt6_ex->rt6i->dst);
+
+	hlist_del_rcu(&rt6_ex->hlist);
+	dst_release(&rt6_ex->rt6i->dst);
+	kfree_rcu(rt6_ex, rcu);
+	WARN_ON_ONCE(!bucket->depth);
+	bucket->depth--;
+}
+
+/* Remove oldest rt6_ex in bucket and free the memory
+ * Caller must hold rt6_exception_lock
+ */
+static void rt6_exception_remove_oldest(struct rt6_exception_bucket *bucket)
+{
+	struct rt6_exception *rt6_ex, *oldest = NULL;
+
+	if (!bucket)
+		return;
+
+	hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
+		if (!oldest || time_before(rt6_ex->stamp, oldest->stamp))
+			oldest = rt6_ex;
+	}
+	rt6_remove_exception(bucket, oldest);
+}
+
+static u32 rt6_exception_hash(const struct in6_addr *dst,
+			      const struct in6_addr *src)
+{
+	static siphash_key_t rt6_exception_key __read_mostly;
+	struct {
+		struct in6_addr dst;
+		struct in6_addr src;
+	} __aligned(SIPHASH_ALIGNMENT) combined = {
+		.dst = *dst,
+	};
+	u64 val;
+
+	net_get_random_once(&rt6_exception_key, sizeof(rt6_exception_key));
+
+#ifdef CONFIG_IPV6_SUBTREES
+	if (src)
+		combined.src = *src;
+#endif
+	val = siphash(&combined, sizeof(combined), &rt6_exception_key);
+
+	return hash_64(val, FIB6_EXCEPTION_BUCKET_SIZE_SHIFT);
+}
+
+/* Helper function to find the cached rt in the hash table
+ * and update bucket pointer to point to the bucket for this
+ * (daddr, saddr) pair
+ * Caller must hold rt6_exception_lock
+ */
+static struct rt6_exception *
+__rt6_find_exception_spinlock(struct rt6_exception_bucket **bucket,
+			      const struct in6_addr *daddr,
+			      const struct in6_addr *saddr)
+{
+	struct rt6_exception *rt6_ex;
+	u32 hval;
+
+	if (!(*bucket) || !daddr)
+		return NULL;
+
+	hval = rt6_exception_hash(daddr, saddr);
+	*bucket += hval;
+
+	hlist_for_each_entry(rt6_ex, &(*bucket)->chain, hlist) {
+		struct rt6_info *rt6 = rt6_ex->rt6i;
+		bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
+
+#ifdef CONFIG_IPV6_SUBTREES
+		if (matched && saddr)
+			matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
+#endif
+		if (matched)
+			return rt6_ex;
+	}
+	return NULL;
+}
+
+/* Helper function to find the cached rt in the hash table
+ * and update bucket pointer to point to the bucket for this
+ * (daddr, saddr) pair
+ * Caller must hold rcu_read_lock()
+ */
+static struct rt6_exception *
+__rt6_find_exception_rcu(struct rt6_exception_bucket **bucket,
+			 const struct in6_addr *daddr,
+			 const struct in6_addr *saddr)
+{
+	struct rt6_exception *rt6_ex;
+	u32 hval;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	if (!(*bucket) || !daddr)
+		return NULL;
+
+	hval = rt6_exception_hash(daddr, saddr);
+	*bucket += hval;
+
+	hlist_for_each_entry_rcu(rt6_ex, &(*bucket)->chain, hlist) {
+		struct rt6_info *rt6 = rt6_ex->rt6i;
+		bool matched = ipv6_addr_equal(daddr, &rt6->rt6i_dst.addr);
+
+#ifdef CONFIG_IPV6_SUBTREES
+		if (matched && saddr)
+			matched = ipv6_addr_equal(saddr, &rt6->rt6i_src.addr);
+#endif
+		if (matched)
+			return rt6_ex;
+	}
+	return NULL;
+}
+
+static unsigned int fib6_mtu(const struct fib6_result *res)
+{
+	const struct fib6_nh *nh = res->nh;
+	unsigned int mtu;
+
+	if (res->f6i->fib6_pmtu) {
+		mtu = res->f6i->fib6_pmtu;
+	} else {
+		struct net_device *dev = nh->fib_nh_dev;
+		struct inet6_dev *idev;
+
+		rcu_read_lock();
+		idev = __in6_dev_get(dev);
+		mtu = idev->cnf.mtu6;
+		rcu_read_unlock();
+	}
+
+	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
+
+	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_nh *nh = res->nh;
+	int max_depth;
+	int err = 0;
+
+	spin_lock_bh(&rt6_exception_lock);
+
+	bucket = rcu_dereference_protected(nh->rt6i_exception_bucket,
+					  lockdep_is_held(&rt6_exception_lock));
+	if (!bucket) {
+		bucket = kcalloc(FIB6_EXCEPTION_BUCKET_SIZE, sizeof(*bucket),
+				 GFP_ATOMIC);
+		if (!bucket) {
+			err = -ENOMEM;
+			goto out;
+		}
+		rcu_assign_pointer(nh->rt6i_exception_bucket, bucket);
+	} else if (fib6_nh_excptn_bucket_flushed(bucket)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+#ifdef CONFIG_IPV6_SUBTREES
+	/* fib6_src.plen != 0 indicates f6i is in subtree
+	 * and exception table is indexed by a hash of
+	 * both fib6_dst and fib6_src.
+	 * Otherwise, the exception table is indexed by
+	 * a hash of only fib6_dst.
+	 */
+	if (f6i->fib6_src.plen)
+		src_key = &nrt->rt6i_src.addr;
+#endif
+	/* rt6_mtu_change() might lower mtu on f6i.
+	 * Only insert this exception route if its mtu
+	 * is less than f6i's mtu value.
+	 */
+	if (dst_metric_raw(&nrt->dst, RTAX_MTU) >= fib6_mtu(res)) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	rt6_ex = __rt6_find_exception_spinlock(&bucket, &nrt->rt6i_dst.addr,
+					       src_key);
+	if (rt6_ex)
+		rt6_remove_exception(bucket, rt6_ex);
+
+	rt6_ex = kzalloc(sizeof(*rt6_ex), GFP_ATOMIC);
+	if (!rt6_ex) {
+		err = -ENOMEM;
+		goto out;
+	}
+	rt6_ex->rt6i = nrt;
+	rt6_ex->stamp = jiffies;
+	hlist_add_head_rcu(&rt6_ex->hlist, &bucket->chain);
+	bucket->depth++;
+	net->ipv6.rt6_stats->fib_rt_cache++;
+
+	/* Randomize max depth to avoid some side channels attacks. */
+	max_depth = FIB6_MAX_DEPTH + prandom_u32_max(FIB6_MAX_DEPTH);
+	while (bucket->depth > max_depth)
+		rt6_exception_remove_oldest(bucket);
+
+out:
+	spin_unlock_bh(&rt6_exception_lock);
+
+	/* Update fn->fn_sernum to invalidate all cached dst */
+	if (!err) {
+		spin_lock_bh(&f6i->fib6_table->tb6_lock);
+		fib6_update_sernum(net, f6i);
+		spin_unlock_bh(&f6i->fib6_table->tb6_lock);
+		fib6_force_start_gc(net);
+	}
+
+	return err;
+}
+
+static void fib6_nh_flush_exceptions(struct fib6_nh *nh, struct fib6_info *from)
+{
+	struct rt6_exception_bucket *bucket;
+	struct rt6_exception *rt6_ex;
+	struct hlist_node *tmp;
+	int i;
+
+	spin_lock_bh(&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) {
+			if (!from ||
+			    rcu_access_pointer(rt6_ex->rt6i->from) == from)
+				rt6_remove_exception(bucket, rt6_ex);
+		}
+		WARN_ON_ONCE(!from && bucket->depth);
+		bucket++;
+	}
+out:
+	spin_unlock_bh(&rt6_exception_lock);
+}
+
+static int rt6_nh_flush_exceptions(struct fib6_nh *nh, void *arg)
+{
+	struct fib6_info *f6i = arg;
+
+	fib6_nh_flush_exceptions(nh, f6i);
+
+	return 0;
+}
+
+void rt6_flush_exceptions(struct fib6_info *f6i)
+{
+	if (f6i->nh)
+		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_flush_exceptions,
+					 f6i);
+	else
+		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()
+ */
+static struct rt6_info *rt6_find_cached_rt(const struct fib6_result *res,
+					   const struct in6_addr *daddr,
+					   const struct in6_addr *saddr)
+{
+	const struct in6_addr *src_key = NULL;
+	struct rt6_exception_bucket *bucket;
+	struct rt6_exception *rt6_ex;
+	struct rt6_info *ret = NULL;
+
+#ifdef CONFIG_IPV6_SUBTREES
+	/* fib6i_src.plen != 0 indicates f6i is in subtree
+	 * and exception table is indexed by a hash of
+	 * both fib6_dst and fib6_src.
+	 * However, the src addr used to create the hash
+	 * might not be exactly the passed in saddr which
+	 * is a /128 addr from the flow.
+	 * So we need to use f6i->fib6_src to redo lookup
+	 * if the passed in saddr does not find anything.
+	 * (See the logic in ip6_rt_cache_alloc() on how
+	 * rt->rt6i_src is updated.)
+	 */
+	if (res->f6i->fib6_src.plen)
+		src_key = saddr;
+find_ex:
+#endif
+	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))
+		ret = rt6_ex->rt6i;
+
+#ifdef CONFIG_IPV6_SUBTREES
+	/* Use fib6_src as src_key and redo lookup */
+	if (!ret && src_key && src_key != &res->f6i->fib6_src.addr) {
+		src_key = &res->f6i->fib6_src.addr;
+		goto find_ex;
+	}
+#endif
+
+	return ret;
+}
+
+/* Remove the passed in cached rt from the hash table that contains it */
+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 rt6_exception *rt6_ex;
+	int err;
+
+	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
+		return -ENOENT;
+
+	spin_lock_bh(&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
+	 * both rt6i_dst and rt6i_src.
+	 * Otherwise, the exception table is indexed by
+	 * a hash of only rt6i_dst.
+	 */
+	if (plen)
+		src_key = &rt->rt6i_src.addr;
+#endif
+	rt6_ex = __rt6_find_exception_spinlock(&bucket,
+					       &rt->rt6i_dst.addr,
+					       src_key);
+	if (rt6_ex) {
+		rt6_remove_exception(bucket, rt6_ex);
+		err = 0;
+	} else {
+		err = -ENOENT;
+	}
+
+	spin_unlock_bh(&rt6_exception_lock);
+	return err;
+}
+
+struct fib6_nh_excptn_arg {
+	struct rt6_info	*rt;
+	int		plen;
+};
+
+static int rt6_nh_remove_exception_rt(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_excptn_arg *arg = _arg;
+	int err;
+
+	err = fib6_nh_remove_exception(nh, arg->plen, arg->rt);
+	if (err == 0)
+		return 1;
+
+	return 0;
+}
+
+static int rt6_remove_exception_rt(struct rt6_info *rt)
+{
+	struct fib6_info *from;
+
+	from = rcu_dereference(rt->from);
+	if (!from || !(rt->rt6i_flags & RTF_CACHE))
+		return -EINVAL;
+
+	if (from->nh) {
+		struct fib6_nh_excptn_arg arg = {
+			.rt = rt,
+			.plen = from->fib6_src.plen
+		};
+		int rc;
+
+		/* rc = 1 means an entry was found */
+		rc = nexthop_for_each_fib6_nh(from->nh,
+					      rt6_nh_remove_exception_rt,
+					      &arg);
+		return rc ? 0 : -ENOENT;
+	}
+
+	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
+	 * both rt6i_dst and rt6i_src.
+	 * Otherwise, the exception table is indexed by
+	 * a hash of only rt6i_dst.
+	 */
+	if (plen)
+		src_key = &rt->rt6i_src.addr;
+#endif
+	rt6_ex = __rt6_find_exception_rcu(&bucket, &rt->rt6i_dst.addr, src_key);
+	if (rt6_ex)
+		rt6_ex->stamp = jiffies;
+}
+
+struct fib6_nh_match_arg {
+	const struct net_device *dev;
+	const struct in6_addr	*gw;
+	struct fib6_nh		*match;
+};
+
+/* determine if fib6_nh has given device and gateway */
+static int fib6_nh_find_match(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_match_arg *arg = _arg;
+
+	if (arg->dev != nh->fib_nh_dev ||
+	    (arg->gw && !nh->fib_nh_gw_family) ||
+	    (!arg->gw && nh->fib_nh_gw_family) ||
+	    (arg->gw && !ipv6_addr_equal(arg->gw, &nh->fib_nh_gw6)))
+		return 0;
+
+	arg->match = nh;
+
+	/* found a match, break the loop */
+	return 1;
+}
+
+static void rt6_update_exception_stamp_rt(struct rt6_info *rt)
+{
+	struct fib6_info *from;
+	struct fib6_nh *fib6_nh;
+
+	rcu_read_lock();
+
+	from = rcu_dereference(rt->from);
+	if (!from || !(rt->rt6i_flags & RTF_CACHE))
+		goto unlock;
+
+	if (from->nh) {
+		struct fib6_nh_match_arg arg = {
+			.dev = rt->dst.dev,
+			.gw = &rt->rt6i_gateway,
+		};
+
+		nexthop_for_each_fib6_nh(from->nh, fib6_nh_find_match, &arg);
+
+		if (!arg.match)
+			goto unlock;
+		fib6_nh = arg.match;
+	} else {
+		fib6_nh = from->fib6_nh;
+	}
+	fib6_nh_update_exception(fib6_nh, from->fib6_src.plen, rt);
+unlock:
+	rcu_read_unlock();
+}
+
+static bool rt6_mtu_change_route_allowed(struct inet6_dev *idev,
+					 struct rt6_info *rt, int mtu)
+{
+	/* If the new MTU is lower than the route PMTU, this new MTU will be the
+	 * lowest MTU in the path: always allow updating the route PMTU to
+	 * reflect PMTU decreases.
+	 *
+	 * If the new MTU is higher, and the route PMTU is equal to the local
+	 * MTU, this means the old MTU is the lowest in the path, so allow
+	 * updating it: if other nodes now have lower MTUs, PMTU discovery will
+	 * handle this.
+	 */
+
+	if (dst_mtu(&rt->dst) >= mtu)
+		return true;
+
+	if (dst_mtu(&rt->dst) == idev->cnf.mtu6)
+		return true;
+
+	return false;
+}
+
+static void rt6_exceptions_update_pmtu(struct inet6_dev *idev,
+				       const struct fib6_nh *nh, int mtu)
+{
+	struct rt6_exception_bucket *bucket;
+	struct rt6_exception *rt6_ex;
+	int i;
+
+	bucket = fib6_nh_get_excptn_bucket(nh, &rt6_exception_lock);
+	if (!bucket)
+		return;
+
+	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
+		hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
+			struct rt6_info *entry = rt6_ex->rt6i;
+
+			/* For RTF_CACHE with rt6i_pmtu == 0 (i.e. a redirected
+			 * route), the metrics of its rt->from have already
+			 * been updated.
+			 */
+			if (dst_metric_raw(&entry->dst, RTAX_MTU) &&
+			    rt6_mtu_change_route_allowed(idev, entry, mtu))
+				dst_metric_set(&entry->dst, RTAX_MTU, mtu);
+		}
+		bucket++;
+	}
+}
+
+#define RTF_CACHE_GATEWAY	(RTF_GATEWAY | RTF_CACHE)
+
+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(nh->rt6i_exception_bucket))
+		return;
+
+	spin_lock_bh(&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,
+						  &bucket->chain, hlist) {
+				struct rt6_info *entry = rt6_ex->rt6i;
+
+				if ((entry->rt6i_flags & RTF_CACHE_GATEWAY) ==
+				    RTF_CACHE_GATEWAY &&
+				    ipv6_addr_equal(gateway,
+						    &entry->rt6i_gateway)) {
+					rt6_remove_exception(bucket, rt6_ex);
+				}
+			}
+			bucket++;
+		}
+	}
+
+	spin_unlock_bh(&rt6_exception_lock);
+}
+
+static void rt6_age_examine_exception(struct rt6_exception_bucket *bucket,
+				      struct rt6_exception *rt6_ex,
+				      struct fib6_gc_args *gc_args,
+				      unsigned long now)
+{
+	struct rt6_info *rt = rt6_ex->rt6i;
+
+	/* we are pruning and obsoleting aged-out and non gateway exceptions
+	 * even if others have still references to them, so that on next
+	 * dst_check() such references can be dropped.
+	 * EXPIRES exceptions - e.g. pmtu-generated ones are pruned when
+	 * expired, independently from their aging, as per RFC 8201 section 4
+	 */
+	if (!(rt->rt6i_flags & RTF_EXPIRES)) {
+		if (time_after_eq(now, rt->dst.lastuse + gc_args->timeout)) {
+			RT6_TRACE("aging clone %p\n", rt);
+			rt6_remove_exception(bucket, rt6_ex);
+			return;
+		}
+	} else if (time_after(jiffies, rt->dst.expires)) {
+		RT6_TRACE("purging expired route %p\n", rt);
+		rt6_remove_exception(bucket, rt6_ex);
+		return;
+	}
+
+	if (rt->rt6i_flags & RTF_GATEWAY) {
+		struct neighbour *neigh;
+		__u8 neigh_flags = 0;
+
+		neigh = __ipv6_neigh_lookup_noref(rt->dst.dev, &rt->rt6i_gateway);
+		if (neigh)
+			neigh_flags = neigh->flags;
+
+		if (!(neigh_flags & NTF_ROUTER)) {
+			RT6_TRACE("purging route %p via non-router but gateway\n",
+				  rt);
+			rt6_remove_exception(bucket, rt6_ex);
+			return;
+		}
+	}
+
+	gc_args->more++;
+}
+
+static void fib6_nh_age_exceptions(const struct fib6_nh *nh,
+				   struct fib6_gc_args *gc_args,
+				   unsigned long now)
+{
+	struct rt6_exception_bucket *bucket;
+	struct rt6_exception *rt6_ex;
+	struct hlist_node *tmp;
+	int i;
+
+	if (!rcu_access_pointer(nh->rt6i_exception_bucket))
+		return;
+
+	rcu_read_lock_bh();
+	spin_lock(&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,
+						  &bucket->chain, hlist) {
+				rt6_age_examine_exception(bucket, rt6_ex,
+							  gc_args, now);
+			}
+			bucket++;
+		}
+	}
+	spin_unlock(&rt6_exception_lock);
+	rcu_read_unlock_bh();
+}
+
+struct fib6_nh_age_excptn_arg {
+	struct fib6_gc_args	*gc_args;
+	unsigned long		now;
+};
+
+static int rt6_nh_age_exceptions(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_age_excptn_arg *arg = _arg;
+
+	fib6_nh_age_exceptions(nh, arg->gc_args, arg->now);
+	return 0;
+}
+
+void rt6_age_exceptions(struct fib6_info *f6i,
+			struct fib6_gc_args *gc_args,
+			unsigned long now)
+{
+	if (f6i->nh) {
+		struct fib6_nh_age_excptn_arg arg = {
+			.gc_args = gc_args,
+			.now = now
+		};
+
+		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_age_exceptions,
+					 &arg);
+	} else {
+		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)
+{
+	struct fib6_node *fn, *saved_fn;
+
+	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
+	saved_fn = fn;
+
+	if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
+		oif = 0;
+
+redo_rt6_select:
+	rt6_select(net, fn, oif, res, strict);
+	if (res->f6i == net->ipv6.fib6_null_entry) {
+		fn = fib6_backtrack(fn, &fl6->saddr);
+		if (fn)
+			goto redo_rt6_select;
+		else if (strict & RT6_LOOKUP_F_REACHABLE) {
+			/* also consider unreachable route */
+			strict &= ~RT6_LOOKUP_F_REACHABLE;
+			fn = saved_fn;
+			goto redo_rt6_select;
+		}
+	}
+
+	trace_fib6_table_lookup(net, res, table, fl6);
+
+	return 0;
+}
+
+struct rt6_info *ip6_pol_route(struct net *net, struct fib6_table *table,
+			       int oif, struct flowi6 *fl6,
+			       const struct sk_buff *skb, int flags)
+{
+	struct fib6_result res = {};
+	struct rt6_info *rt = NULL;
+	int strict = 0;
+
+	WARN_ON_ONCE((flags & RT6_LOOKUP_F_DST_NOREF) &&
+		     !rcu_read_lock_held());
+
+	strict |= flags & RT6_LOOKUP_F_IFACE;
+	strict |= flags & RT6_LOOKUP_F_IGNORE_LINKSTATE;
+	if (net->ipv6.devconf_all->forwarding == 0)
+		strict |= RT6_LOOKUP_F_REACHABLE;
+
+	rcu_read_lock();
+
+	fib6_table_lookup(net, table, oif, fl6, &res, strict);
+	if (res.f6i == net->ipv6.fib6_null_entry)
+		goto out;
+
+	fib6_select_path(net, &res, fl6, oif, false, skb, strict);
+
+	/*Search through exception table */
+	rt = rt6_find_cached_rt(&res, &fl6->daddr, &fl6->saddr);
+	if (rt) {
+		goto out;
+	} else if (unlikely((fl6->flowi6_flags & FLOWI_FLAG_KNOWN_NH) &&
+			    !res.nh->fib_nh_gw_family)) {
+		/* Create a RTF_CACHE clone which will not be
+		 * owned by the fib6 tree.  It is for the special case where
+		 * the daddr in the skb during the neighbor look-up is different
+		 * from the fl6->daddr used to look-up route here.
+		 */
+		rt = ip6_rt_cache_alloc(&res, &fl6->daddr, NULL);
+
+		if (rt) {
+			/* 1 refcnt is taken during ip6_rt_cache_alloc().
+			 * As rt6_uncached_list_add() does not consume refcnt,
+			 * this refcnt is always returned to the caller even
+			 * if caller sets RT6_LOOKUP_F_DST_NOREF flag.
+			 */
+			rt6_uncached_list_add(rt);
+			atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
+			rcu_read_unlock();
+
+			return rt;
+		}
+	} else {
+		/* Get a percpu copy */
+		local_bh_disable();
+		rt = rt6_get_pcpu_route(&res);
+
+		if (!rt)
+			rt = rt6_make_pcpu_route(net, &res);
+
+		local_bh_enable();
+	}
+out:
+	if (!rt)
+		rt = net->ipv6.ip6_null_entry;
+	if (!(flags & RT6_LOOKUP_F_DST_NOREF))
+		ip6_hold_safe(net, &rt);
+	rcu_read_unlock();
+
+	return rt;
+}
+EXPORT_SYMBOL_GPL(ip6_pol_route);
+
+INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_input(struct net *net,
+					    struct fib6_table *table,
+					    struct flowi6 *fl6,
+					    const struct sk_buff *skb,
+					    int flags)
+{
+	return ip6_pol_route(net, table, fl6->flowi6_iif, fl6, skb, flags);
+}
+
+struct dst_entry *ip6_route_input_lookup(struct net *net,
+					 struct net_device *dev,
+					 struct flowi6 *fl6,
+					 const struct sk_buff *skb,
+					 int flags)
+{
+	if (rt6_need_strict(&fl6->daddr) && dev->type != ARPHRD_PIMREG)
+		flags |= RT6_LOOKUP_F_IFACE;
+
+	return fib6_rule_lookup(net, fl6, skb, flags, ip6_pol_route_input);
+}
+EXPORT_SYMBOL_GPL(ip6_route_input_lookup);
+
+static void ip6_multipath_l3_keys(const struct sk_buff *skb,
+				  struct flow_keys *keys,
+				  struct flow_keys *flkeys)
+{
+	const struct ipv6hdr *outer_iph = ipv6_hdr(skb);
+	const struct ipv6hdr *key_iph = outer_iph;
+	struct flow_keys *_flkeys = flkeys;
+	const struct ipv6hdr *inner_iph;
+	const struct icmp6hdr *icmph;
+	struct ipv6hdr _inner_iph;
+	struct icmp6hdr _icmph;
+
+	if (likely(outer_iph->nexthdr != IPPROTO_ICMPV6))
+		goto out;
+
+	icmph = skb_header_pointer(skb, skb_transport_offset(skb),
+				   sizeof(_icmph), &_icmph);
+	if (!icmph)
+		goto out;
+
+	if (!icmpv6_is_err(icmph->icmp6_type))
+		goto out;
+
+	inner_iph = skb_header_pointer(skb,
+				       skb_transport_offset(skb) + sizeof(*icmph),
+				       sizeof(_inner_iph), &_inner_iph);
+	if (!inner_iph)
+		goto out;
+
+	key_iph = inner_iph;
+	_flkeys = NULL;
+out:
+	if (_flkeys) {
+		keys->addrs.v6addrs.src = _flkeys->addrs.v6addrs.src;
+		keys->addrs.v6addrs.dst = _flkeys->addrs.v6addrs.dst;
+		keys->tags.flow_label = _flkeys->tags.flow_label;
+		keys->basic.ip_proto = _flkeys->basic.ip_proto;
+	} else {
+		keys->addrs.v6addrs.src = key_iph->saddr;
+		keys->addrs.v6addrs.dst = key_iph->daddr;
+		keys->tags.flow_label = ip6_flowlabel(key_iph);
+		keys->basic.ip_proto = key_iph->nexthdr;
+	}
+}
+
+/* if skb is set it will be used and fl6 can be NULL */
+u32 rt6_multipath_hash(const struct net *net, const struct flowi6 *fl6,
+		       const struct sk_buff *skb, struct flow_keys *flkeys)
+{
+	struct flow_keys hash_keys;
+	u32 mhash;
+
+	switch (ip6_multipath_hash_policy(net)) {
+	case 0:
+		memset(&hash_keys, 0, sizeof(hash_keys));
+		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+		if (skb) {
+			ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
+		} else {
+			hash_keys.addrs.v6addrs.src = fl6->saddr;
+			hash_keys.addrs.v6addrs.dst = fl6->daddr;
+			hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
+			hash_keys.basic.ip_proto = fl6->flowi6_proto;
+		}
+		break;
+	case 1:
+		if (skb) {
+			unsigned int flag = FLOW_DISSECTOR_F_STOP_AT_ENCAP;
+			struct flow_keys keys;
+
+			/* short-circuit if we already have L4 hash present */
+			if (skb->l4_hash)
+				return skb_get_hash_raw(skb) >> 1;
+
+			memset(&hash_keys, 0, sizeof(hash_keys));
+
+                        if (!flkeys) {
+				skb_flow_dissect_flow_keys(skb, &keys, flag);
+				flkeys = &keys;
+			}
+			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+			hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
+			hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
+			hash_keys.ports.src = flkeys->ports.src;
+			hash_keys.ports.dst = flkeys->ports.dst;
+			hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
+		} else {
+			memset(&hash_keys, 0, sizeof(hash_keys));
+			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+			hash_keys.addrs.v6addrs.src = fl6->saddr;
+			hash_keys.addrs.v6addrs.dst = fl6->daddr;
+			hash_keys.ports.src = fl6->fl6_sport;
+			hash_keys.ports.dst = fl6->fl6_dport;
+			hash_keys.basic.ip_proto = fl6->flowi6_proto;
+		}
+		break;
+	case 2:
+		memset(&hash_keys, 0, sizeof(hash_keys));
+		hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+		if (skb) {
+			struct flow_keys keys;
+
+			if (!flkeys) {
+				skb_flow_dissect_flow_keys(skb, &keys, 0);
+				flkeys = &keys;
+			}
+
+			/* Inner can be v4 or v6 */
+			if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV4_ADDRS) {
+				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
+				hash_keys.addrs.v4addrs.src = flkeys->addrs.v4addrs.src;
+				hash_keys.addrs.v4addrs.dst = flkeys->addrs.v4addrs.dst;
+			} else if (flkeys->control.addr_type == FLOW_DISSECTOR_KEY_IPV6_ADDRS) {
+				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+				hash_keys.addrs.v6addrs.src = flkeys->addrs.v6addrs.src;
+				hash_keys.addrs.v6addrs.dst = flkeys->addrs.v6addrs.dst;
+				hash_keys.tags.flow_label = flkeys->tags.flow_label;
+				hash_keys.basic.ip_proto = flkeys->basic.ip_proto;
+			} else {
+				/* Same as case 0 */
+				hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+				ip6_multipath_l3_keys(skb, &hash_keys, flkeys);
+			}
+		} else {
+			/* Same as case 0 */
+			hash_keys.control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
+			hash_keys.addrs.v6addrs.src = fl6->saddr;
+			hash_keys.addrs.v6addrs.dst = fl6->daddr;
+			hash_keys.tags.flow_label = (__force u32)flowi6_get_flowlabel(fl6);
+			hash_keys.basic.ip_proto = fl6->flowi6_proto;
+		}
+		break;
+	}
+	mhash = flow_hash_from_keys(&hash_keys);
+
+	return mhash >> 1;
+}
+
+/* Called with rcu held */
+void ip6_route_input(struct sk_buff *skb)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	struct net *net = dev_net(skb->dev);
+	int flags = RT6_LOOKUP_F_HAS_SADDR | RT6_LOOKUP_F_DST_NOREF;
+	struct ip_tunnel_info *tun_info;
+	struct flowi6 fl6 = {
+		.flowi6_iif = skb->dev->ifindex,
+		.daddr = iph->daddr,
+		.saddr = iph->saddr,
+		.flowlabel = ip6_flowinfo(iph),
+		.flowi6_mark = skb->mark,
+		.flowi6_proto = iph->nexthdr,
+	};
+	struct flow_keys *flkeys = NULL, _flkeys;
+
+	tun_info = skb_tunnel_info(skb);
+	if (tun_info && !(tun_info->mode & IP_TUNNEL_INFO_TX))
+		fl6.flowi6_tun_key.tun_id = tun_info->key.tun_id;
+
+	if (fib6_rules_early_flow_dissect(net, skb, &fl6, &_flkeys))
+		flkeys = &_flkeys;
+
+	if (unlikely(fl6.flowi6_proto == IPPROTO_ICMPV6))
+		fl6.mp_hash = rt6_multipath_hash(net, &fl6, skb, flkeys);
+	skb_dst_drop(skb);
+	skb_dst_set_noref(skb, ip6_route_input_lookup(net, skb->dev,
+						      &fl6, skb, flags));
+}
+
+INDIRECT_CALLABLE_SCOPE struct rt6_info *ip6_pol_route_output(struct net *net,
+					     struct fib6_table *table,
+					     struct flowi6 *fl6,
+					     const struct sk_buff *skb,
+					     int flags)
+{
+	return ip6_pol_route(net, table, fl6->flowi6_oif, fl6, skb, flags);
+}
+
+struct dst_entry *ip6_route_output_flags_noref(struct net *net,
+					       const struct sock *sk,
+					       struct flowi6 *fl6, int flags)
+{
+	bool any_src;
+
+	if (ipv6_addr_type(&fl6->daddr) &
+	    (IPV6_ADDR_MULTICAST | IPV6_ADDR_LINKLOCAL)) {
+		struct dst_entry *dst;
+
+		/* This function does not take refcnt on the dst */
+		dst = l3mdev_link_scope_lookup(net, fl6);
+		if (dst)
+			return dst;
+	}
+
+	fl6->flowi6_iif = LOOPBACK_IFINDEX;
+
+	flags |= RT6_LOOKUP_F_DST_NOREF;
+	any_src = ipv6_addr_any(&fl6->saddr);
+	if ((sk && sk->sk_bound_dev_if) || rt6_need_strict(&fl6->daddr) ||
+	    (fl6->flowi6_oif && any_src))
+		flags |= RT6_LOOKUP_F_IFACE;
+
+	if (!any_src)
+		flags |= RT6_LOOKUP_F_HAS_SADDR;
+	else if (sk)
+		flags |= rt6_srcprefs2flags(inet6_sk(sk)->srcprefs);
+
+	return fib6_rule_lookup(net, fl6, NULL, flags, ip6_pol_route_output);
+}
+EXPORT_SYMBOL_GPL(ip6_route_output_flags_noref);
+
+struct dst_entry *ip6_route_output_flags(struct net *net,
+					 const struct sock *sk,
+					 struct flowi6 *fl6,
+					 int flags)
+{
+        struct dst_entry *dst;
+        struct rt6_info *rt6;
+
+        rcu_read_lock();
+        dst = ip6_route_output_flags_noref(net, sk, fl6, flags);
+        rt6 = (struct rt6_info *)dst;
+        /* For dst cached in uncached_list, refcnt is already taken. */
+        if (list_empty(&rt6->rt6i_uncached) && !dst_hold_safe(dst)) {
+                dst = &net->ipv6.ip6_null_entry->dst;
+                dst_hold(dst);
+        }
+        rcu_read_unlock();
+
+        return dst;
+}
+EXPORT_SYMBOL_GPL(ip6_route_output_flags);
+
+struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_orig)
+{
+	struct rt6_info *rt, *ort = (struct rt6_info *) dst_orig;
+	struct net_device *loopback_dev = net->loopback_dev;
+	struct dst_entry *new = NULL;
+
+	rt = dst_alloc(&ip6_dst_blackhole_ops, loopback_dev, 1,
+		       DST_OBSOLETE_DEAD, 0);
+	if (rt) {
+		rt6_info_init(rt);
+		atomic_inc(&net->ipv6.rt6_stats->fib_rt_alloc);
+
+		new = &rt->dst;
+		new->__use = 1;
+		new->input = dst_discard;
+		new->output = dst_discard_out;
+
+		dst_copy_metrics(new, &ort->dst);
+
+		rt->rt6i_idev = in6_dev_get(loopback_dev);
+		rt->rt6i_gateway = ort->rt6i_gateway;
+		rt->rt6i_flags = ort->rt6i_flags & ~RTF_PCPU;
+
+		memcpy(&rt->rt6i_dst, &ort->rt6i_dst, sizeof(struct rt6key));
+#ifdef CONFIG_IPV6_SUBTREES
+		memcpy(&rt->rt6i_src, &ort->rt6i_src, sizeof(struct rt6key));
+#endif
+	}
+
+	dst_release(dst_orig);
+	return new ? new : ERR_PTR(-ENOMEM);
+}
+
+/*
+ *	Destination cache support functions
+ */
+
+static bool fib6_check(struct fib6_info *f6i, u32 cookie)
+{
+	u32 rt_cookie = 0;
+
+	if (!fib6_get_cookie_safe(f6i, &rt_cookie) || rt_cookie != cookie)
+		return false;
+
+	if (fib6_check_expired(f6i))
+		return false;
+
+	return true;
+}
+
+static struct dst_entry *rt6_check(struct rt6_info *rt,
+				   struct fib6_info *from,
+				   u32 cookie)
+{
+	u32 rt_cookie = 0;
+
+	if (!from || !fib6_get_cookie_safe(from, &rt_cookie) ||
+	    rt_cookie != cookie)
+		return NULL;
+
+	if (rt6_check_expired(rt))
+		return NULL;
+
+	return &rt->dst;
+}
+
+static struct dst_entry *rt6_dst_from_check(struct rt6_info *rt,
+					    struct fib6_info *from,
+					    u32 cookie)
+{
+	if (!__rt6_check_expired(rt) &&
+	    rt->dst.obsolete == DST_OBSOLETE_FORCE_CHK &&
+	    fib6_check(from, cookie))
+		return &rt->dst;
+	else
+		return NULL;
+}
+
+static struct dst_entry *ip6_dst_check(struct dst_entry *dst, u32 cookie)
+{
+	struct dst_entry *dst_ret;
+	struct fib6_info *from;
+	struct rt6_info *rt;
+
+	rt = container_of(dst, struct rt6_info, dst);
+
+	if (rt->sernum)
+		return rt6_is_valid(rt) ? dst : NULL;
+
+	rcu_read_lock();
+
+	/* All IPV6 dsts are created with ->obsolete set to the value
+	 * DST_OBSOLETE_FORCE_CHK which forces validation calls down
+	 * into this function always.
+	 */
+
+	from = rcu_dereference(rt->from);
+
+	if (from && (rt->rt6i_flags & RTF_PCPU ||
+	    unlikely(!list_empty(&rt->rt6i_uncached))))
+		dst_ret = rt6_dst_from_check(rt, from, cookie);
+	else
+		dst_ret = rt6_check(rt, from, cookie);
+
+	rcu_read_unlock();
+
+	return dst_ret;
+}
+
+static struct dst_entry *ip6_negative_advice(struct dst_entry *dst)
+{
+	struct rt6_info *rt = (struct rt6_info *) dst;
+
+	if (rt) {
+		if (rt->rt6i_flags & RTF_CACHE) {
+			rcu_read_lock();
+			if (rt6_check_expired(rt)) {
+				rt6_remove_exception_rt(rt);
+				dst = NULL;
+			}
+			rcu_read_unlock();
+		} else {
+			dst_release(dst);
+			dst = NULL;
+		}
+	}
+	return dst;
+}
+
+static void ip6_link_failure(struct sk_buff *skb)
+{
+	struct rt6_info *rt;
+
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, ICMPV6_ADDR_UNREACH, 0);
+
+	rt = (struct rt6_info *) skb_dst(skb);
+	if (rt) {
+		rcu_read_lock();
+		if (rt->rt6i_flags & RTF_CACHE) {
+			rt6_remove_exception_rt(rt);
+		} else {
+			struct fib6_info *from;
+			struct fib6_node *fn;
+
+			from = rcu_dereference(rt->from);
+			if (from) {
+				fn = rcu_dereference(from->fib6_node);
+				if (fn && (rt->rt6i_flags & RTF_DEFAULT))
+					WRITE_ONCE(fn->fn_sernum, -1);
+			}
+		}
+		rcu_read_unlock();
+	}
+}
+
+static void rt6_update_expires(struct rt6_info *rt0, int timeout)
+{
+	if (!(rt0->rt6i_flags & RTF_EXPIRES)) {
+		struct fib6_info *from;
+
+		rcu_read_lock();
+		from = rcu_dereference(rt0->from);
+		if (from)
+			rt0->dst.expires = from->expires;
+		rcu_read_unlock();
+	}
+
+	dst_set_expires(&rt0->dst, timeout);
+	rt0->rt6i_flags |= RTF_EXPIRES;
+}
+
+static void rt6_do_update_pmtu(struct rt6_info *rt, u32 mtu)
+{
+	struct net *net = dev_net(rt->dst.dev);
+
+	dst_metric_set(&rt->dst, RTAX_MTU, mtu);
+	rt->rt6i_flags |= RTF_MODIFIED;
+	rt6_update_expires(rt, net->ipv6.sysctl.ip6_rt_mtu_expires);
+}
+
+static bool rt6_cache_allowed_for_pmtu(const struct rt6_info *rt)
+{
+	return !(rt->rt6i_flags & RTF_CACHE) &&
+		(rt->rt6i_flags & RTF_PCPU || rcu_access_pointer(rt->from));
+}
+
+static void __ip6_rt_update_pmtu(struct dst_entry *dst, const struct sock *sk,
+				 const struct ipv6hdr *iph, u32 mtu,
+				 bool confirm_neigh)
+{
+	const struct in6_addr *daddr, *saddr;
+	struct rt6_info *rt6 = (struct rt6_info *)dst;
+
+	/* Note: do *NOT* check dst_metric_locked(dst, RTAX_MTU)
+	 * IPv6 pmtu discovery isn't optional, so 'mtu lock' cannot disable it.
+	 * [see also comment in rt6_mtu_change_route()]
+	 */
+
+	if (iph) {
+		daddr = &iph->daddr;
+		saddr = &iph->saddr;
+	} else if (sk) {
+		daddr = &sk->sk_v6_daddr;
+		saddr = &inet6_sk(sk)->saddr;
+	} else {
+		daddr = NULL;
+		saddr = NULL;
+	}
+
+	if (confirm_neigh)
+		dst_confirm_neigh(dst, daddr);
+
+	if (mtu < IPV6_MIN_MTU)
+		return;
+	if (mtu >= dst_mtu(dst))
+		return;
+
+	if (!rt6_cache_allowed_for_pmtu(rt6)) {
+		rt6_do_update_pmtu(rt6, mtu);
+		/* update rt6_ex->stamp for cache */
+		if (rt6->rt6i_flags & RTF_CACHE)
+			rt6_update_exception_stamp_rt(rt6);
+	} else if (daddr) {
+		struct fib6_result res = {};
+		struct rt6_info *nrt6;
+
+		rcu_read_lock();
+		res.f6i = rcu_dereference(rt6->from);
+		if (!res.f6i)
+			goto out_unlock;
+
+		res.fib6_flags = res.f6i->fib6_flags;
+		res.fib6_type = res.f6i->fib6_type;
+
+		if (res.f6i->nh) {
+			struct fib6_nh_match_arg arg = {
+				.dev = dst->dev,
+				.gw = &rt6->rt6i_gateway,
+			};
+
+			nexthop_for_each_fib6_nh(res.f6i->nh,
+						 fib6_nh_find_match, &arg);
+
+			/* fib6_info uses a nexthop that does not have fib6_nh
+			 * using the dst->dev + gw. Should be impossible.
+			 */
+			if (!arg.match)
+				goto out_unlock;
+
+			res.nh = arg.match;
+		} else {
+			res.nh = res.f6i->fib6_nh;
+		}
+
+		nrt6 = ip6_rt_cache_alloc(&res, daddr, saddr);
+		if (nrt6) {
+			rt6_do_update_pmtu(nrt6, mtu);
+			if (rt6_insert_exception(nrt6, &res))
+				dst_release_immediate(&nrt6->dst);
+		}
+out_unlock:
+		rcu_read_unlock();
+	}
+}
+
+static void ip6_rt_update_pmtu(struct dst_entry *dst, struct sock *sk,
+			       struct sk_buff *skb, u32 mtu,
+			       bool confirm_neigh)
+{
+	__ip6_rt_update_pmtu(dst, sk, skb ? ipv6_hdr(skb) : NULL, mtu,
+			     confirm_neigh);
+}
+
+void ip6_update_pmtu(struct sk_buff *skb, struct net *net, __be32 mtu,
+		     int oif, u32 mark, kuid_t uid)
+{
+	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
+	struct dst_entry *dst;
+	struct flowi6 fl6 = {
+		.flowi6_oif = oif,
+		.flowi6_mark = mark ? mark : IP6_REPLY_MARK(net, skb->mark),
+		.daddr = iph->daddr,
+		.saddr = iph->saddr,
+		.flowlabel = ip6_flowinfo(iph),
+		.flowi6_uid = uid,
+	};
+
+	dst = ip6_route_output(net, NULL, &fl6);
+	if (!dst->error)
+		__ip6_rt_update_pmtu(dst, NULL, iph, ntohl(mtu), true);
+	dst_release(dst);
+}
+EXPORT_SYMBOL_GPL(ip6_update_pmtu);
+
+void ip6_sk_update_pmtu(struct sk_buff *skb, struct sock *sk, __be32 mtu)
+{
+	int oif = sk->sk_bound_dev_if;
+	struct dst_entry *dst;
+
+	if (!oif && skb->dev)
+		oif = l3mdev_master_ifindex(skb->dev);
+
+	ip6_update_pmtu(skb, sock_net(sk), mtu, oif, sk->sk_mark, sk->sk_uid);
+
+	dst = __sk_dst_get(sk);
+	if (!dst || !dst->obsolete ||
+	    dst->ops->check(dst, inet6_sk(sk)->dst_cookie))
+		return;
+
+	bh_lock_sock(sk);
+	if (!sock_owned_by_user(sk) && !ipv6_addr_v4mapped(&sk->sk_v6_daddr))
+		ip6_datagram_dst_update(sk, false);
+	bh_unlock_sock(sk);
+}
+EXPORT_SYMBOL_GPL(ip6_sk_update_pmtu);
+
+void ip6_sk_dst_store_flow(struct sock *sk, struct dst_entry *dst,
+			   const struct flowi6 *fl6)
+{
+#ifdef CONFIG_IPV6_SUBTREES
+	struct ipv6_pinfo *np = inet6_sk(sk);
+#endif
+
+	ip6_dst_store(sk, dst,
+		      ipv6_addr_equal(&fl6->daddr, &sk->sk_v6_daddr) ?
+		      &sk->sk_v6_daddr : NULL,
+#ifdef CONFIG_IPV6_SUBTREES
+		      ipv6_addr_equal(&fl6->saddr, &np->saddr) ?
+		      &np->saddr :
+#endif
+		      NULL);
+}
+
+static bool ip6_redirect_nh_match(const struct fib6_result *res,
+				  struct flowi6 *fl6,
+				  const struct in6_addr *gw,
+				  struct rt6_info **ret)
+{
+	const struct fib6_nh *nh = res->nh;
+
+	if (nh->fib_nh_flags & RTNH_F_DEAD || !nh->fib_nh_gw_family ||
+	    fl6->flowi6_oif != nh->fib_nh_dev->ifindex)
+		return false;
+
+	/* rt_cache's gateway might be different from its 'parent'
+	 * in the case of an ip redirect.
+	 * So we keep searching in the exception table if the gateway
+	 * is different.
+	 */
+	if (!ipv6_addr_equal(gw, &nh->fib_nh_gw6)) {
+		struct rt6_info *rt_cache;
+
+		rt_cache = rt6_find_cached_rt(res, &fl6->daddr, &fl6->saddr);
+		if (rt_cache &&
+		    ipv6_addr_equal(gw, &rt_cache->rt6i_gateway)) {
+			*ret = rt_cache;
+			return true;
+		}
+		return false;
+	}
+	return true;
+}
+
+struct fib6_nh_rd_arg {
+	struct fib6_result	*res;
+	struct flowi6		*fl6;
+	const struct in6_addr	*gw;
+	struct rt6_info		**ret;
+};
+
+static int fib6_nh_redirect_match(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_rd_arg *arg = _arg;
+
+	arg->res->nh = nh;
+	return ip6_redirect_nh_match(arg->res, arg->fl6, arg->gw, arg->ret);
+}
+
+/* Handle redirects */
+struct ip6rd_flowi {
+	struct flowi6 fl6;
+	struct in6_addr gateway;
+};
+
+INDIRECT_CALLABLE_SCOPE struct rt6_info *__ip6_route_redirect(struct net *net,
+					     struct fib6_table *table,
+					     struct flowi6 *fl6,
+					     const struct sk_buff *skb,
+					     int flags)
+{
+	struct ip6rd_flowi *rdfl = (struct ip6rd_flowi *)fl6;
+	struct rt6_info *ret = NULL;
+	struct fib6_result res = {};
+	struct fib6_nh_rd_arg arg = {
+		.res = &res,
+		.fl6 = fl6,
+		.gw  = &rdfl->gateway,
+		.ret = &ret
+	};
+	struct fib6_info *rt;
+	struct fib6_node *fn;
+
+	/* l3mdev_update_flow overrides oif if the device is enslaved; in
+	 * this case we must match on the real ingress device, so reset it
+	 */
+	if (fl6->flowi6_flags & FLOWI_FLAG_SKIP_NH_OIF)
+		fl6->flowi6_oif = skb->dev->ifindex;
+
+	/* Get the "current" route for this destination and
+	 * check if the redirect has come from appropriate router.
+	 *
+	 * RFC 4861 specifies that redirects should only be
+	 * accepted if they come from the nexthop to the target.
+	 * Due to the way the routes are chosen, this notion
+	 * is a bit fuzzy and one might need to check all possible
+	 * routes.
+	 */
+
+	rcu_read_lock();
+	fn = fib6_node_lookup(&table->tb6_root, &fl6->daddr, &fl6->saddr);
+restart:
+	for_each_fib6_node_rt_rcu(fn) {
+		res.f6i = rt;
+		if (fib6_check_expired(rt))
+			continue;
+		if (rt->fib6_flags & RTF_REJECT)
+			break;
+		if (unlikely(rt->nh)) {
+			if (nexthop_is_blackhole(rt->nh))
+				continue;
+			/* on match, res->nh is filled in and potentially ret */
+			if (nexthop_for_each_fib6_nh(rt->nh,
+						     fib6_nh_redirect_match,
+						     &arg))
+				goto out;
+		} else {
+			res.nh = rt->fib6_nh;
+			if (ip6_redirect_nh_match(&res, fl6, &rdfl->gateway,
+						  &ret))
+				goto out;
+		}
+	}
+
+	if (!rt)
+		rt = net->ipv6.fib6_null_entry;
+	else if (rt->fib6_flags & RTF_REJECT) {
+		ret = net->ipv6.ip6_null_entry;
+		goto out;
+	}
+
+	if (rt == net->ipv6.fib6_null_entry) {
+		fn = fib6_backtrack(fn, &fl6->saddr);
+		if (fn)
+			goto restart;
+	}
+
+	res.f6i = rt;
+	res.nh = rt->fib6_nh;
+out:
+	if (ret) {
+		ip6_hold_safe(net, &ret);
+	} else {
+		res.fib6_flags = res.f6i->fib6_flags;
+		res.fib6_type = res.f6i->fib6_type;
+		ret = ip6_create_rt_rcu(&res);
+	}
+
+	rcu_read_unlock();
+
+	trace_fib6_table_lookup(net, &res, table, fl6);
+	return ret;
+};
+
+static struct dst_entry *ip6_route_redirect(struct net *net,
+					    const struct flowi6 *fl6,
+					    const struct sk_buff *skb,
+					    const struct in6_addr *gateway)
+{
+	int flags = RT6_LOOKUP_F_HAS_SADDR;
+	struct ip6rd_flowi rdfl;
+
+	rdfl.fl6 = *fl6;
+	rdfl.gateway = *gateway;
+
+	return fib6_rule_lookup(net, &rdfl.fl6, skb,
+				flags, __ip6_route_redirect);
+}
+
+void ip6_redirect(struct sk_buff *skb, struct net *net, int oif, u32 mark,
+		  kuid_t uid)
+{
+	const struct ipv6hdr *iph = (struct ipv6hdr *) skb->data;
+	struct dst_entry *dst;
+	struct flowi6 fl6 = {
+		.flowi6_iif = LOOPBACK_IFINDEX,
+		.flowi6_oif = oif,
+		.flowi6_mark = mark,
+		.daddr = iph->daddr,
+		.saddr = iph->saddr,
+		.flowlabel = ip6_flowinfo(iph),
+		.flowi6_uid = uid,
+	};
+
+	dst = ip6_route_redirect(net, &fl6, skb, &ipv6_hdr(skb)->saddr);
+	rt6_do_redirect(dst, NULL, skb);
+	dst_release(dst);
+}
+EXPORT_SYMBOL_GPL(ip6_redirect);
+
+void ip6_redirect_no_header(struct sk_buff *skb, struct net *net, int oif)
+{
+	const struct ipv6hdr *iph = ipv6_hdr(skb);
+	const struct rd_msg *msg = (struct rd_msg *)icmp6_hdr(skb);
+	struct dst_entry *dst;
+	struct flowi6 fl6 = {
+		.flowi6_iif = LOOPBACK_IFINDEX,
+		.flowi6_oif = oif,
+		.daddr = msg->dest,
+		.saddr = iph->daddr,
+		.flowi6_uid = sock_net_uid(net, NULL),
+	};
+
+	dst = ip6_route_redirect(net, &fl6, skb, &iph->saddr);
+	rt6_do_redirect(dst, NULL, skb);
+	dst_release(dst);
+}
+
+void ip6_sk_redirect(struct sk_buff *skb, struct sock *sk)
+{
+	ip6_redirect(skb, sock_net(sk), sk->sk_bound_dev_if, sk->sk_mark,
+		     sk->sk_uid);
+}
+EXPORT_SYMBOL_GPL(ip6_sk_redirect);
+
+static unsigned int ip6_default_advmss(const struct dst_entry *dst)
+{
+	struct net_device *dev = dst->dev;
+	unsigned int mtu = dst_mtu(dst);
+	struct net *net = dev_net(dev);
+
+	mtu -= sizeof(struct ipv6hdr) + sizeof(struct tcphdr);
+
+	if (mtu < net->ipv6.sysctl.ip6_rt_min_advmss)
+		mtu = net->ipv6.sysctl.ip6_rt_min_advmss;
+
+	/*
+	 * Maximal non-jumbo IPv6 payload is IPV6_MAXPLEN and
+	 * corresponding MSS is IPV6_MAXPLEN - tcp_header_size.
+	 * IPV6_MAXPLEN is also valid and means: "any MSS,
+	 * rely only on pmtu discovery"
+	 */
+	if (mtu > IPV6_MAXPLEN - sizeof(struct tcphdr))
+		mtu = IPV6_MAXPLEN;
+	return mtu;
+}
+
+static unsigned int ip6_mtu(const struct dst_entry *dst)
+{
+	struct inet6_dev *idev;
+	unsigned int mtu;
+
+	mtu = dst_metric_raw(dst, RTAX_MTU);
+	if (mtu)
+		goto out;
+
+	mtu = IPV6_MIN_MTU;
+
+	rcu_read_lock();
+	idev = __in6_dev_get(dst->dev);
+	if (idev)
+		mtu = idev->cnf.mtu6;
+	rcu_read_unlock();
+
+out:
+	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
+
+	return mtu - lwtunnel_headroom(dst->lwtstate, mtu);
+}
+
+/* MTU selection:
+ * 1. mtu on route is locked - use it
+ * 2. mtu from nexthop exception
+ * 3. mtu from egress device
+ *
+ * based on ip6_dst_mtu_forward and exception logic of
+ * rt6_find_cached_rt; called with rcu_read_lock
+ */
+u32 ip6_mtu_from_fib6(const struct fib6_result *res,
+		      const struct in6_addr *daddr,
+		      const struct in6_addr *saddr)
+{
+	const struct fib6_nh *nh = res->nh;
+	struct fib6_info *f6i = res->f6i;
+	struct inet6_dev *idev;
+	struct rt6_info *rt;
+	u32 mtu = 0;
+
+	if (unlikely(fib6_metric_locked(f6i, RTAX_MTU))) {
+		mtu = f6i->fib6_pmtu;
+		if (mtu)
+			goto out;
+	}
+
+	rt = rt6_find_cached_rt(res, daddr, saddr);
+	if (unlikely(rt)) {
+		mtu = dst_metric_raw(&rt->dst, RTAX_MTU);
+	} else {
+		struct net_device *dev = nh->fib_nh_dev;
+
+		mtu = IPV6_MIN_MTU;
+		idev = __in6_dev_get(dev);
+		if (idev && idev->cnf.mtu6 > mtu)
+			mtu = idev->cnf.mtu6;
+	}
+
+	mtu = min_t(unsigned int, mtu, IP6_MAX_MTU);
+out:
+	return mtu - lwtunnel_headroom(nh->fib_nh_lws, mtu);
+}
+
+struct dst_entry *icmp6_dst_alloc(struct net_device *dev,
+				  struct flowi6 *fl6)
+{
+	struct dst_entry *dst;
+	struct rt6_info *rt;
+	struct inet6_dev *idev = in6_dev_get(dev);
+	struct net *net = dev_net(dev);
+
+	if (unlikely(!idev))
+		return ERR_PTR(-ENODEV);
+
+	rt = ip6_dst_alloc(net, dev, 0);
+	if (unlikely(!rt)) {
+		in6_dev_put(idev);
+		dst = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	rt->dst.input = ip6_input;
+	rt->dst.output  = ip6_output;
+	rt->rt6i_gateway  = fl6->daddr;
+	rt->rt6i_dst.addr = fl6->daddr;
+	rt->rt6i_dst.plen = 128;
+	rt->rt6i_idev     = idev;
+	dst_metric_set(&rt->dst, RTAX_HOPLIMIT, 0);
+
+	/* Add this dst into uncached_list so that rt6_disable_ip() can
+	 * do proper release of the net_device
+	 */
+	rt6_uncached_list_add(rt);
+	atomic_inc(&net->ipv6.rt6_stats->fib_rt_uncache);
+
+	dst = xfrm_lookup(net, &rt->dst, flowi6_to_flowi(fl6), NULL, 0);
+
+out:
+	return dst;
+}
+
+static void ip6_dst_gc(struct dst_ops *ops)
+{
+	struct net *net = container_of(ops, struct net, ipv6.ip6_dst_ops);
+	int rt_min_interval = net->ipv6.sysctl.ip6_rt_gc_min_interval;
+	int rt_elasticity = net->ipv6.sysctl.ip6_rt_gc_elasticity;
+	int rt_gc_timeout = net->ipv6.sysctl.ip6_rt_gc_timeout;
+	unsigned long rt_last_gc = net->ipv6.ip6_rt_last_gc;
+	unsigned int val;
+	int entries;
+
+	entries = dst_entries_get_fast(ops);
+	if (entries > ops->gc_thresh)
+		entries = dst_entries_get_slow(ops);
+
+	if (time_after(rt_last_gc + rt_min_interval, jiffies))
+		goto out;
+
+	fib6_run_gc(atomic_inc_return(&net->ipv6.ip6_rt_gc_expire), net, true);
+	entries = dst_entries_get_slow(ops);
+	if (entries < ops->gc_thresh)
+		atomic_set(&net->ipv6.ip6_rt_gc_expire, rt_gc_timeout >> 1);
+out:
+	val = atomic_read(&net->ipv6.ip6_rt_gc_expire);
+	atomic_set(&net->ipv6.ip6_rt_gc_expire, val - (val >> rt_elasticity));
+}
+
+static int ip6_nh_lookup_table(struct net *net, struct fib6_config *cfg,
+			       const struct in6_addr *gw_addr, u32 tbid,
+			       int flags, struct fib6_result *res)
+{
+	struct flowi6 fl6 = {
+		.flowi6_oif = cfg->fc_ifindex,
+		.daddr = *gw_addr,
+		.saddr = cfg->fc_prefsrc,
+	};
+	struct fib6_table *table;
+	int err;
+
+	table = fib6_get_table(net, tbid);
+	if (!table)
+		return -EINVAL;
+
+	if (!ipv6_addr_any(&cfg->fc_prefsrc))
+		flags |= RT6_LOOKUP_F_HAS_SADDR;
+
+	flags |= RT6_LOOKUP_F_IGNORE_LINKSTATE;
+
+	err = fib6_table_lookup(net, table, cfg->fc_ifindex, &fl6, res, flags);
+	if (!err && res->f6i != net->ipv6.fib6_null_entry)
+		fib6_select_path(net, res, &fl6, cfg->fc_ifindex,
+				 cfg->fc_ifindex != 0, NULL, flags);
+
+	return err;
+}
+
+static int ip6_route_check_nh_onlink(struct net *net,
+				     struct fib6_config *cfg,
+				     const struct net_device *dev,
+				     struct netlink_ext_ack *extack)
+{
+	u32 tbid = l3mdev_fib_table_rcu(dev) ? : RT_TABLE_MAIN;
+	const struct in6_addr *gw_addr = &cfg->fc_gateway;
+	struct fib6_result res = {};
+	int err;
+
+	err = ip6_nh_lookup_table(net, cfg, gw_addr, tbid, 0, &res);
+	if (!err && !(res.fib6_flags & RTF_REJECT) &&
+	    /* ignore match if it is the default route */
+	    !ipv6_addr_any(&res.f6i->fib6_dst.addr) &&
+	    (res.fib6_type != RTN_UNICAST || dev != res.nh->fib_nh_dev)) {
+		NL_SET_ERR_MSG(extack,
+			       "Nexthop has invalid gateway or device mismatch");
+		err = -EINVAL;
+	}
+
+	return err;
+}
+
+static int ip6_route_check_nh(struct net *net,
+			      struct fib6_config *cfg,
+			      struct net_device **_dev,
+			      struct inet6_dev **idev)
+{
+	const struct in6_addr *gw_addr = &cfg->fc_gateway;
+	struct net_device *dev = _dev ? *_dev : NULL;
+	int flags = RT6_LOOKUP_F_IFACE;
+	struct fib6_result res = {};
+	int err = -EHOSTUNREACH;
+
+	if (cfg->fc_table) {
+		err = ip6_nh_lookup_table(net, cfg, gw_addr,
+					  cfg->fc_table, flags, &res);
+		/* gw_addr can not require a gateway or resolve to a reject
+		 * route. If a device is given, it must match the result.
+		 */
+		if (err || res.fib6_flags & RTF_REJECT ||
+		    res.nh->fib_nh_gw_family ||
+		    (dev && dev != res.nh->fib_nh_dev))
+			err = -EHOSTUNREACH;
+	}
+
+	if (err < 0) {
+		struct flowi6 fl6 = {
+			.flowi6_oif = cfg->fc_ifindex,
+			.daddr = *gw_addr,
+		};
+
+		err = fib6_lookup(net, cfg->fc_ifindex, &fl6, &res, flags);
+		if (err || res.fib6_flags & RTF_REJECT ||
+		    res.nh->fib_nh_gw_family)
+			err = -EHOSTUNREACH;
+
+		if (err)
+			return err;
+
+		fib6_select_path(net, &res, &fl6, cfg->fc_ifindex,
+				 cfg->fc_ifindex != 0, NULL, flags);
+	}
+
+	err = 0;
+	if (dev) {
+		if (dev != res.nh->fib_nh_dev)
+			err = -EHOSTUNREACH;
+	} else {
+		*_dev = dev = res.nh->fib_nh_dev;
+		dev_hold(dev);
+		*idev = in6_dev_get(dev);
+	}
+
+	return err;
+}
+
+static int ip6_validate_gw(struct net *net, struct fib6_config *cfg,
+			   struct net_device **_dev, struct inet6_dev **idev,
+			   struct netlink_ext_ack *extack)
+{
+	const struct in6_addr *gw_addr = &cfg->fc_gateway;
+	int gwa_type = ipv6_addr_type(gw_addr);
+	bool skip_dev = gwa_type & IPV6_ADDR_LINKLOCAL ? false : true;
+	const struct net_device *dev = *_dev;
+	bool need_addr_check = !dev;
+	int err = -EINVAL;
+
+	/* if gw_addr is local we will fail to detect this in case
+	 * address is still TENTATIVE (DAD in progress). rt6_lookup()
+	 * will return already-added prefix route via interface that
+	 * prefix route was assigned to, which might be non-loopback.
+	 */
+	if (dev &&
+	    ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
+		NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
+		goto out;
+	}
+
+	if (gwa_type != (IPV6_ADDR_LINKLOCAL | IPV6_ADDR_UNICAST)) {
+		/* IPv6 strictly inhibits using not link-local
+		 * addresses as nexthop address.
+		 * Otherwise, router will not able to send redirects.
+		 * It is very good, but in some (rare!) circumstances
+		 * (SIT, PtP, NBMA NOARP links) it is handy to allow
+		 * some exceptions. --ANK
+		 * We allow IPv4-mapped nexthops to support RFC4798-type
+		 * addressing
+		 */
+		if (!(gwa_type & (IPV6_ADDR_UNICAST | IPV6_ADDR_MAPPED))) {
+			NL_SET_ERR_MSG(extack, "Invalid gateway address");
+			goto out;
+		}
+
+		rcu_read_lock();
+
+		if (cfg->fc_flags & RTNH_F_ONLINK)
+			err = ip6_route_check_nh_onlink(net, cfg, dev, extack);
+		else
+			err = ip6_route_check_nh(net, cfg, _dev, idev);
+
+		rcu_read_unlock();
+
+		if (err)
+			goto out;
+	}
+
+	/* reload in case device was changed */
+	dev = *_dev;
+
+	err = -EINVAL;
+	if (!dev) {
+		NL_SET_ERR_MSG(extack, "Egress device not specified");
+		goto out;
+	} else if (dev->flags & IFF_LOOPBACK) {
+		NL_SET_ERR_MSG(extack,
+			       "Egress device can not be loopback device for this route");
+		goto out;
+	}
+
+	/* if we did not check gw_addr above, do so now that the
+	 * egress device has been resolved.
+	 */
+	if (need_addr_check &&
+	    ipv6_chk_addr_and_flags(net, gw_addr, dev, skip_dev, 0, 0)) {
+		NL_SET_ERR_MSG(extack, "Gateway can not be a local address");
+		goto out;
+	}
+
+	err = 0;
+out:
+	return err;
+}
+
+static bool fib6_is_reject(u32 flags, struct net_device *dev, int addr_type)
+{
+	if ((flags & RTF_REJECT) ||
+	    (dev && (dev->flags & IFF_LOOPBACK) &&
+	     !(addr_type & IPV6_ADDR_LOOPBACK) &&
+	     !(flags & (RTF_ANYCAST | RTF_LOCAL))))
+		return true;
+
+	return false;
+}
+
+int fib6_nh_init(struct net *net, struct fib6_nh *fib6_nh,
+		 struct fib6_config *cfg, gfp_t gfp_flags,
+		 struct netlink_ext_ack *extack)
+{
+	struct net_device *dev = NULL;
+	struct inet6_dev *idev = NULL;
+	int addr_type;
+	int err;
+
+	fib6_nh->fib_nh_family = AF_INET6;
+#ifdef CONFIG_IPV6_ROUTER_PREF
+	fib6_nh->last_probe = jiffies;
+#endif
+	if (cfg->fc_is_fdb) {
+		fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
+		fib6_nh->fib_nh_gw_family = AF_INET6;
+		return 0;
+	}
+
+	err = -ENODEV;
+	if (cfg->fc_ifindex) {
+		dev = dev_get_by_index(net, cfg->fc_ifindex);
+		if (!dev)
+			goto out;
+		idev = in6_dev_get(dev);
+		if (!idev)
+			goto out;
+	}
+
+	if (cfg->fc_flags & RTNH_F_ONLINK) {
+		if (!dev) {
+			NL_SET_ERR_MSG(extack,
+				       "Nexthop device required for onlink");
+			goto out;
+		}
+
+		if (!(dev->flags & IFF_UP)) {
+			NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+			err = -ENETDOWN;
+			goto out;
+		}
+
+		fib6_nh->fib_nh_flags |= RTNH_F_ONLINK;
+	}
+
+	fib6_nh->fib_nh_weight = 1;
+
+	/* We cannot add true routes via loopback here,
+	 * 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, dev, addr_type)) {
+		/* hold loopback dev/idev if we haven't done so. */
+		if (dev != net->loopback_dev) {
+			if (dev) {
+				dev_put(dev);
+				in6_dev_put(idev);
+			}
+			dev = net->loopback_dev;
+			dev_hold(dev);
+			idev = in6_dev_get(dev);
+			if (!idev) {
+				err = -ENODEV;
+				goto out;
+			}
+		}
+		goto pcpu_alloc;
+	}
+
+	if (cfg->fc_flags & RTF_GATEWAY) {
+		err = ip6_validate_gw(net, cfg, &dev, &idev, extack);
+		if (err)
+			goto out;
+
+		fib6_nh->fib_nh_gw6 = cfg->fc_gateway;
+		fib6_nh->fib_nh_gw_family = AF_INET6;
+	}
+
+	err = -ENODEV;
+	if (!dev)
+		goto out;
+
+	if (idev->cnf.disable_ipv6) {
+		NL_SET_ERR_MSG(extack, "IPv6 is disabled on nexthop device");
+		err = -EACCES;
+		goto out;
+	}
+
+	if (!(dev->flags & IFF_UP) && !cfg->fc_ignore_dev_down) {
+		NL_SET_ERR_MSG(extack, "Nexthop device is not up");
+		err = -ENETDOWN;
+		goto out;
+	}
+
+	if (!(cfg->fc_flags & (RTF_LOCAL | RTF_ANYCAST)) &&
+	    !netif_carrier_ok(dev))
+		fib6_nh->fib_nh_flags |= RTNH_F_LINKDOWN;
+
+	err = fib_nh_common_init(net, &fib6_nh->nh_common, cfg->fc_encap,
+				 cfg->fc_encap_type, cfg, gfp_flags, extack);
+	if (err)
+		goto out;
+
+pcpu_alloc:
+	fib6_nh->rt6i_pcpu = alloc_percpu_gfp(struct rt6_info *, gfp_flags);
+	if (!fib6_nh->rt6i_pcpu) {
+		err = -ENOMEM;
+		goto out;
+	}
+
+	fib6_nh->fib_nh_dev = dev;
+	fib6_nh->fib_nh_oif = dev->ifindex;
+	err = 0;
+out:
+	if (idev)
+		in6_dev_put(idev);
+
+	if (err) {
+		lwtstate_put(fib6_nh->fib_nh_lws);
+		fib6_nh->fib_nh_lws = NULL;
+		if (dev)
+			dev_put(dev);
+	}
+
+	return err;
+}
+
+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);
+}
+
+void fib6_nh_release_dsts(struct fib6_nh *fib6_nh)
+{
+	int cpu;
+
+	if (!fib6_nh->rt6i_pcpu)
+		return;
+
+	for_each_possible_cpu(cpu) {
+		struct rt6_info *pcpu_rt, **ppcpu_rt;
+
+		ppcpu_rt = per_cpu_ptr(fib6_nh->rt6i_pcpu, cpu);
+		pcpu_rt = xchg(ppcpu_rt, NULL);
+		if (pcpu_rt) {
+			dst_dev_put(&pcpu_rt->dst);
+			dst_release(&pcpu_rt->dst);
+		}
+	}
+}
+
+static struct fib6_info *ip6_route_info_create(struct fib6_config *cfg,
+					      gfp_t gfp_flags,
+					      struct netlink_ext_ack *extack)
+{
+	struct net *net = cfg->fc_nlinfo.nl_net;
+	struct fib6_info *rt = NULL;
+	struct nexthop *nh = NULL;
+	struct fib6_table *table;
+	struct fib6_nh *fib6_nh;
+	int err = -EINVAL;
+	int addr_type;
+
+	/* RTF_PCPU is an internal flag; can not be set by userspace */
+	if (cfg->fc_flags & RTF_PCPU) {
+		NL_SET_ERR_MSG(extack, "Userspace can not set RTF_PCPU");
+		goto out;
+	}
+
+	/* RTF_CACHE is an internal flag; can not be set by userspace */
+	if (cfg->fc_flags & RTF_CACHE) {
+		NL_SET_ERR_MSG(extack, "Userspace can not set RTF_CACHE");
+		goto out;
+	}
+
+	if (cfg->fc_type > RTN_MAX) {
+		NL_SET_ERR_MSG(extack, "Invalid route type");
+		goto out;
+	}
+
+	if (cfg->fc_dst_len > 128) {
+		NL_SET_ERR_MSG(extack, "Invalid prefix length");
+		goto out;
+	}
+	if (cfg->fc_src_len > 128) {
+		NL_SET_ERR_MSG(extack, "Invalid source address length");
+		goto out;
+	}
+#ifndef CONFIG_IPV6_SUBTREES
+	if (cfg->fc_src_len) {
+		NL_SET_ERR_MSG(extack,
+			       "Specifying source address requires IPV6_SUBTREES to be enabled");
+		goto out;
+	}
+#endif
+	if (cfg->fc_nh_id) {
+		nh = nexthop_find_by_id(net, cfg->fc_nh_id);
+		if (!nh) {
+			NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
+			goto out;
+		}
+		err = fib6_check_nexthop(nh, cfg, extack);
+		if (err)
+			goto out;
+	}
+
+	err = -ENOBUFS;
+	if (cfg->fc_nlinfo.nlh &&
+	    !(cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_CREATE)) {
+		table = fib6_get_table(net, cfg->fc_table);
+		if (!table) {
+			pr_warn("NLM_F_CREATE should be specified when creating new route\n");
+			table = fib6_new_table(net, cfg->fc_table);
+		}
+	} else {
+		table = fib6_new_table(net, cfg->fc_table);
+	}
+
+	if (!table)
+		goto out;
+
+	err = -ENOMEM;
+	rt = fib6_info_alloc(gfp_flags, !nh);
+	if (!rt)
+		goto out;
+
+	rt->fib6_metrics = ip_fib_metrics_init(net, cfg->fc_mx, cfg->fc_mx_len,
+					       extack);
+	if (IS_ERR(rt->fib6_metrics)) {
+		err = PTR_ERR(rt->fib6_metrics);
+		/* Do not leave garbage there. */
+		rt->fib6_metrics = (struct dst_metrics *)&dst_default_metrics;
+		goto out_free;
+	}
+
+	if (cfg->fc_flags & RTF_ADDRCONF)
+		rt->dst_nocount = true;
+
+	if (cfg->fc_flags & RTF_EXPIRES)
+		fib6_set_expires(rt, jiffies +
+				clock_t_to_jiffies(cfg->fc_expires));
+	else
+		fib6_clean_expires(rt);
+
+	if (cfg->fc_protocol == RTPROT_UNSPEC)
+		cfg->fc_protocol = RTPROT_BOOT;
+	rt->fib6_protocol = cfg->fc_protocol;
+
+	rt->fib6_table = table;
+	rt->fib6_metric = cfg->fc_metric;
+	rt->fib6_type = cfg->fc_type ? : RTN_UNICAST;
+	rt->fib6_flags = cfg->fc_flags & ~RTF_GATEWAY;
+
+	ipv6_addr_prefix(&rt->fib6_dst.addr, &cfg->fc_dst, cfg->fc_dst_len);
+	rt->fib6_dst.plen = cfg->fc_dst_len;
+
+#ifdef CONFIG_IPV6_SUBTREES
+	ipv6_addr_prefix(&rt->fib6_src.addr, &cfg->fc_src, cfg->fc_src_len);
+	rt->fib6_src.plen = cfg->fc_src_len;
+#endif
+	if (nh) {
+		if (rt->fib6_src.plen) {
+			NL_SET_ERR_MSG(extack, "Nexthops can not be used with source routing");
+			goto out_free;
+		}
+		if (!nexthop_get(nh)) {
+			NL_SET_ERR_MSG(extack, "Nexthop has been deleted");
+			goto out_free;
+		}
+		rt->nh = nh;
+		fib6_nh = nexthop_fib6_nh(rt->nh);
+	} else {
+		err = fib6_nh_init(net, rt->fib6_nh, cfg, gfp_flags, extack);
+		if (err)
+			goto out;
+
+		fib6_nh = rt->fib6_nh;
+
+		/* We cannot add true routes via loopback here, 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))
+			rt->fib6_flags = RTF_REJECT | RTF_NONEXTHOP;
+	}
+
+	if (!ipv6_addr_any(&cfg->fc_prefsrc)) {
+		struct net_device *dev = fib6_nh->fib_nh_dev;
+
+		if (!ipv6_chk_addr(net, &cfg->fc_prefsrc, dev, 0)) {
+			NL_SET_ERR_MSG(extack, "Invalid source address");
+			err = -EINVAL;
+			goto out;
+		}
+		rt->fib6_prefsrc.addr = cfg->fc_prefsrc;
+		rt->fib6_prefsrc.plen = 128;
+	} else
+		rt->fib6_prefsrc.plen = 0;
+
+	return rt;
+out:
+	fib6_info_release(rt);
+	return ERR_PTR(err);
+out_free:
+	ip_fib_metrics_put(rt->fib6_metrics);
+	kfree(rt);
+	return ERR_PTR(err);
+}
+
+int ip6_route_add(struct fib6_config *cfg, gfp_t gfp_flags,
+		  struct netlink_ext_ack *extack)
+{
+	struct fib6_info *rt;
+	int err;
+
+	rt = ip6_route_info_create(cfg, gfp_flags, extack);
+	if (IS_ERR(rt))
+		return PTR_ERR(rt);
+
+	err = __ip6_ins_rt(rt, &cfg->fc_nlinfo, extack);
+	fib6_info_release(rt);
+
+	return err;
+}
+
+static int __ip6_del_rt(struct fib6_info *rt, struct nl_info *info)
+{
+	struct net *net = info->nl_net;
+	struct fib6_table *table;
+	int err;
+
+	if (rt == net->ipv6.fib6_null_entry) {
+		err = -ENOENT;
+		goto out;
+	}
+
+	table = rt->fib6_table;
+	spin_lock_bh(&table->tb6_lock);
+	err = fib6_del(rt, info);
+	spin_unlock_bh(&table->tb6_lock);
+
+out:
+	fib6_info_release(rt);
+	return err;
+}
+
+int ip6_del_rt(struct net *net, struct fib6_info *rt, bool skip_notify)
+{
+	struct nl_info info = {
+		.nl_net = net,
+		.skip_notify = skip_notify
+	};
+
+	return __ip6_del_rt(rt, &info);
+}
+
+static int __ip6_del_rt_siblings(struct fib6_info *rt, struct fib6_config *cfg)
+{
+	struct nl_info *info = &cfg->fc_nlinfo;
+	struct net *net = info->nl_net;
+	struct sk_buff *skb = NULL;
+	struct fib6_table *table;
+	int err = -ENOENT;
+
+	if (rt == net->ipv6.fib6_null_entry)
+		goto out_put;
+	table = rt->fib6_table;
+	spin_lock_bh(&table->tb6_lock);
+
+	if (rt->fib6_nsiblings && cfg->fc_delete_all_nh) {
+		struct fib6_info *sibling, *next_sibling;
+		struct fib6_node *fn;
+
+		/* prefer to send a single notification with all hops */
+		skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
+		if (skb) {
+			u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+
+			if (rt6_fill_node(net, skb, rt, NULL,
+					  NULL, NULL, 0, RTM_DELROUTE,
+					  info->portid, seq, 0) < 0) {
+				kfree_skb(skb);
+				skb = NULL;
+			} else
+				info->skip_notify = 1;
+		}
+
+		/* 'rt' points to the first sibling route. If it is not the
+		 * leaf, then we do not need to send a notification. Otherwise,
+		 * we need to check if the last sibling has a next route or not
+		 * and emit a replace or delete notification, respectively.
+		 */
+		info->skip_notify_kernel = 1;
+		fn = rcu_dereference_protected(rt->fib6_node,
+					    lockdep_is_held(&table->tb6_lock));
+		if (rcu_access_pointer(fn->leaf) == rt) {
+			struct fib6_info *last_sibling, *replace_rt;
+
+			last_sibling = list_last_entry(&rt->fib6_siblings,
+						       struct fib6_info,
+						       fib6_siblings);
+			replace_rt = rcu_dereference_protected(
+					    last_sibling->fib6_next,
+					    lockdep_is_held(&table->tb6_lock));
+			if (replace_rt)
+				call_fib6_entry_notifiers_replace(net,
+								  replace_rt);
+			else
+				call_fib6_multipath_entry_notifiers(net,
+						       FIB_EVENT_ENTRY_DEL,
+						       rt, rt->fib6_nsiblings,
+						       NULL);
+		}
+		list_for_each_entry_safe(sibling, next_sibling,
+					 &rt->fib6_siblings,
+					 fib6_siblings) {
+			err = fib6_del(sibling, info);
+			if (err)
+				goto out_unlock;
+		}
+	}
+
+	err = fib6_del(rt, info);
+out_unlock:
+	spin_unlock_bh(&table->tb6_lock);
+out_put:
+	fib6_info_release(rt);
+
+	if (skb) {
+		rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
+			    info->nlh, gfp_any());
+	}
+	return err;
+}
+
+static int __ip6_del_cached_rt(struct rt6_info *rt, struct fib6_config *cfg)
+{
+	int rc = -ESRCH;
+
+	if (cfg->fc_ifindex && rt->dst.dev->ifindex != cfg->fc_ifindex)
+		goto out;
+
+	if (cfg->fc_flags & RTF_GATEWAY &&
+	    !ipv6_addr_equal(&cfg->fc_gateway, &rt->rt6i_gateway))
+		goto out;
+
+	rc = rt6_remove_exception_rt(rt);
+out:
+	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;
+}
+
+struct fib6_nh_del_cached_rt_arg {
+	struct fib6_config *cfg;
+	struct fib6_info *f6i;
+};
+
+static int fib6_nh_del_cached_rt(struct fib6_nh *nh, void *_arg)
+{
+	struct fib6_nh_del_cached_rt_arg *arg = _arg;
+	int rc;
+
+	rc = ip6_del_cached_rt(arg->cfg, arg->f6i, nh);
+	return rc != -ESRCH ? rc : 0;
+}
+
+static int ip6_del_cached_rt_nh(struct fib6_config *cfg, struct fib6_info *f6i)
+{
+	struct fib6_nh_del_cached_rt_arg arg = {
+		.cfg = cfg,
+		.f6i = f6i
+	};
+
+	return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_del_cached_rt, &arg);
+}
+
+static int ip6_route_del(struct fib6_config *cfg,
+			 struct netlink_ext_ack *extack)
+{
+	struct fib6_table *table;
+	struct fib6_info *rt;
+	struct fib6_node *fn;
+	int err = -ESRCH;
+
+	table = fib6_get_table(cfg->fc_nlinfo.nl_net, cfg->fc_table);
+	if (!table) {
+		NL_SET_ERR_MSG(extack, "FIB table does not exist");
+		return err;
+	}
+
+	rcu_read_lock();
+
+	fn = fib6_locate(&table->tb6_root,
+			 &cfg->fc_dst, cfg->fc_dst_len,
+			 &cfg->fc_src, cfg->fc_src_len,
+			 !(cfg->fc_flags & RTF_CACHE));
+
+	if (fn) {
+		for_each_fib6_node_rt_rcu(fn) {
+			struct fib6_nh *nh;
+
+			if (rt->nh && cfg->fc_nh_id &&
+			    rt->nh->id != cfg->fc_nh_id)
+				continue;
+
+			if (cfg->fc_flags & RTF_CACHE) {
+				int rc = 0;
+
+				if (rt->nh) {
+					rc = ip6_del_cached_rt_nh(cfg, rt);
+				} else if (cfg->fc_nh_id) {
+					continue;
+				} else {
+					nh = rt->fib6_nh;
+					rc = ip6_del_cached_rt(cfg, rt, nh);
+				}
+				if (rc != -ESRCH) {
+					rcu_read_unlock();
+					return rc;
+				}
+				continue;
+			}
+
+			if (cfg->fc_metric && cfg->fc_metric != rt->fib6_metric)
+				continue;
+			if (cfg->fc_protocol &&
+			    cfg->fc_protocol != rt->fib6_protocol)
+				continue;
+
+			if (rt->nh) {
+				if (!fib6_info_hold_safe(rt))
+					continue;
+				rcu_read_unlock();
+
+				return __ip6_del_rt(rt, &cfg->fc_nlinfo);
+			}
+			if (cfg->fc_nh_id)
+				continue;
+
+			nh = rt->fib6_nh;
+			if (cfg->fc_ifindex &&
+			    (!nh->fib_nh_dev ||
+			     nh->fib_nh_dev->ifindex != cfg->fc_ifindex))
+				continue;
+			if (cfg->fc_flags & RTF_GATEWAY &&
+			    !ipv6_addr_equal(&cfg->fc_gateway, &nh->fib_nh_gw6))
+				continue;
+			if (!fib6_info_hold_safe(rt))
+				continue;
+			rcu_read_unlock();
+
+			/* if gateway was specified only delete the one hop */
+			if (cfg->fc_flags & RTF_GATEWAY)
+				return __ip6_del_rt(rt, &cfg->fc_nlinfo);
+
+			return __ip6_del_rt_siblings(rt, cfg);
+		}
+	}
+	rcu_read_unlock();
+
+	return err;
+}
+
+static void rt6_do_redirect(struct dst_entry *dst, struct sock *sk, struct sk_buff *skb)
+{
+	struct netevent_redirect netevent;
+	struct rt6_info *rt, *nrt = NULL;
+	struct fib6_result res = {};
+	struct ndisc_options ndopts;
+	struct inet6_dev *in6_dev;
+	struct neighbour *neigh;
+	struct rd_msg *msg;
+	int optlen, on_link;
+	u8 *lladdr;
+
+	optlen = skb_tail_pointer(skb) - skb_transport_header(skb);
+	optlen -= sizeof(*msg);
+
+	if (optlen < 0) {
+		net_dbg_ratelimited("rt6_do_redirect: packet too short\n");
+		return;
+	}
+
+	msg = (struct rd_msg *)icmp6_hdr(skb);
+
+	if (ipv6_addr_is_multicast(&msg->dest)) {
+		net_dbg_ratelimited("rt6_do_redirect: destination address is multicast\n");
+		return;
+	}
+
+	on_link = 0;
+	if (ipv6_addr_equal(&msg->dest, &msg->target)) {
+		on_link = 1;
+	} else if (ipv6_addr_type(&msg->target) !=
+		   (IPV6_ADDR_UNICAST|IPV6_ADDR_LINKLOCAL)) {
+		net_dbg_ratelimited("rt6_do_redirect: target address is not link-local unicast\n");
+		return;
+	}
+
+	in6_dev = __in6_dev_get(skb->dev);
+	if (!in6_dev)
+		return;
+	if (in6_dev->cnf.forwarding || !in6_dev->cnf.accept_redirects)
+		return;
+
+	/* RFC2461 8.1:
+	 *	The IP source address of the Redirect MUST be the same as the current
+	 *	first-hop router for the specified ICMP Destination Address.
+	 */
+
+	if (!ndisc_parse_options(skb->dev, msg->opt, optlen, &ndopts)) {
+		net_dbg_ratelimited("rt6_redirect: invalid ND options\n");
+		return;
+	}
+
+	lladdr = NULL;
+	if (ndopts.nd_opts_tgt_lladdr) {
+		lladdr = ndisc_opt_addr_data(ndopts.nd_opts_tgt_lladdr,
+					     skb->dev);
+		if (!lladdr) {
+			net_dbg_ratelimited("rt6_redirect: invalid link-layer address length\n");
+			return;
+		}
+	}
+
+	rt = (struct rt6_info *) dst;
+	if (rt->rt6i_flags & RTF_REJECT) {
+		net_dbg_ratelimited("rt6_redirect: source isn't a valid nexthop for redirect target\n");
+		return;
+	}
+
+	/* Redirect received -> path was valid.
+	 * Look, redirects are sent only in response to data packets,
+	 * so that this nexthop apparently is reachable. --ANK
+	 */
+	dst_confirm_neigh(&rt->dst, &ipv6_hdr(skb)->saddr);
+
+	neigh = __neigh_lookup(&nd_tbl, &msg->target, skb->dev, 1);
+	if (!neigh)
+		return;
+
+	/*
+	 *	We have finally decided to accept it.
+	 */
+
+	ndisc_update(skb->dev, neigh, lladdr, NUD_STALE,
+		     NEIGH_UPDATE_F_WEAK_OVERRIDE|
+		     NEIGH_UPDATE_F_OVERRIDE|
+		     (on_link ? 0 : (NEIGH_UPDATE_F_OVERRIDE_ISROUTER|
+				     NEIGH_UPDATE_F_ISROUTER)),
+		     NDISC_REDIRECT, &ndopts);
+
+	rcu_read_lock();
+	res.f6i = rcu_dereference(rt->from);
+	if (!res.f6i)
+		goto out;
+
+	if (res.f6i->nh) {
+		struct fib6_nh_match_arg arg = {
+			.dev = dst->dev,
+			.gw = &rt->rt6i_gateway,
+		};
+
+		nexthop_for_each_fib6_nh(res.f6i->nh,
+					 fib6_nh_find_match, &arg);
+
+		/* fib6_info uses a nexthop that does not have fib6_nh
+		 * using the dst->dev. Should be impossible
+		 */
+		if (!arg.match)
+			goto out;
+		res.nh = arg.match;
+	} else {
+		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);
+	if (!nrt)
+		goto out;
+
+	nrt->rt6i_flags = RTF_GATEWAY|RTF_UP|RTF_DYNAMIC|RTF_CACHE;
+	if (on_link)
+		nrt->rt6i_flags &= ~RTF_GATEWAY;
+
+	nrt->rt6i_gateway = *(struct in6_addr *)neigh->primary_key;
+
+	/* rt6_insert_exception() will take care of duplicated exceptions */
+	if (rt6_insert_exception(nrt, &res)) {
+		dst_release_immediate(&nrt->dst);
+		goto out;
+	}
+
+	netevent.old = &rt->dst;
+	netevent.new = &nrt->dst;
+	netevent.daddr = &msg->dest;
+	netevent.neigh = neigh;
+	call_netevent_notifiers(NETEVENT_REDIRECT, &netevent);
+
+out:
+	rcu_read_unlock();
+	neigh_release(neigh);
+}
+
+#ifdef CONFIG_IPV6_ROUTE_INFO
+static struct fib6_info *rt6_get_route_info(struct net *net,
+					   const struct in6_addr *prefix, int prefixlen,
+					   const struct in6_addr *gwaddr,
+					   struct net_device *dev)
+{
+	u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
+	int ifindex = dev->ifindex;
+	struct fib6_node *fn;
+	struct fib6_info *rt = NULL;
+	struct fib6_table *table;
+
+	table = fib6_get_table(net, tb_id);
+	if (!table)
+		return NULL;
+
+	rcu_read_lock();
+	fn = fib6_locate(&table->tb6_root, prefix, prefixlen, NULL, 0, true);
+	if (!fn)
+		goto out;
+
+	for_each_fib6_node_rt_rcu(fn) {
+		/* these routes do not use nexthops */
+		if (rt->nh)
+			continue;
+		if (rt->fib6_nh->fib_nh_dev->ifindex != ifindex)
+			continue;
+		if (!(rt->fib6_flags & RTF_ROUTEINFO) ||
+		    !rt->fib6_nh->fib_nh_gw_family)
+			continue;
+		if (!ipv6_addr_equal(&rt->fib6_nh->fib_nh_gw6, gwaddr))
+			continue;
+		if (!fib6_info_hold_safe(rt))
+			continue;
+		break;
+	}
+out:
+	rcu_read_unlock();
+	return rt;
+}
+
+static struct fib6_info *rt6_add_route_info(struct net *net,
+					   const struct in6_addr *prefix, int prefixlen,
+					   const struct in6_addr *gwaddr,
+					   struct net_device *dev,
+					   unsigned int pref)
+{
+	struct fib6_config cfg = {
+		.fc_metric	= IP6_RT_PRIO_USER,
+		.fc_ifindex	= dev->ifindex,
+		.fc_dst_len	= prefixlen,
+		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_ROUTEINFO |
+				  RTF_UP | RTF_PREF(pref),
+		.fc_protocol = RTPROT_RA,
+		.fc_type = RTN_UNICAST,
+		.fc_nlinfo.portid = 0,
+		.fc_nlinfo.nlh = NULL,
+		.fc_nlinfo.nl_net = net,
+	};
+
+	cfg.fc_table = l3mdev_fib_table(dev) ? : RT6_TABLE_INFO;
+	cfg.fc_dst = *prefix;
+	cfg.fc_gateway = *gwaddr;
+
+	/* We should treat it as a default route if prefix length is 0. */
+	if (!prefixlen)
+		cfg.fc_flags |= RTF_DEFAULT;
+
+	ip6_route_add(&cfg, GFP_ATOMIC, NULL);
+
+	return rt6_get_route_info(net, prefix, prefixlen, gwaddr, dev);
+}
+#endif
+
+struct fib6_info *rt6_get_dflt_router(struct net *net,
+				     const struct in6_addr *addr,
+				     struct net_device *dev)
+{
+	u32 tb_id = l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT;
+	struct fib6_info *rt;
+	struct fib6_table *table;
+
+	table = fib6_get_table(net, tb_id);
+	if (!table)
+		return NULL;
+
+	rcu_read_lock();
+	for_each_fib6_node_rt_rcu(&table->tb6_root) {
+		struct fib6_nh *nh;
+
+		/* RA routes do not use nexthops */
+		if (rt->nh)
+			continue;
+
+		nh = rt->fib6_nh;
+		if (dev == nh->fib_nh_dev &&
+		    ((rt->fib6_flags & (RTF_ADDRCONF | RTF_DEFAULT)) == (RTF_ADDRCONF | RTF_DEFAULT)) &&
+		    ipv6_addr_equal(&nh->fib_nh_gw6, addr))
+			break;
+	}
+	if (rt && !fib6_info_hold_safe(rt))
+		rt = NULL;
+	rcu_read_unlock();
+	return rt;
+}
+
+struct fib6_info *rt6_add_dflt_router(struct net *net,
+				     const struct in6_addr *gwaddr,
+				     struct net_device *dev,
+				     unsigned int pref)
+{
+	struct fib6_config cfg = {
+		.fc_table	= l3mdev_fib_table(dev) ? : RT6_TABLE_DFLT,
+		.fc_metric	= IP6_RT_PRIO_USER,
+		.fc_ifindex	= dev->ifindex,
+		.fc_flags	= RTF_GATEWAY | RTF_ADDRCONF | RTF_DEFAULT |
+				  RTF_UP | RTF_EXPIRES | RTF_PREF(pref),
+		.fc_protocol = RTPROT_RA,
+		.fc_type = RTN_UNICAST,
+		.fc_nlinfo.portid = 0,
+		.fc_nlinfo.nlh = NULL,
+		.fc_nlinfo.nl_net = net,
+	};
+
+	cfg.fc_gateway = *gwaddr;
+
+	if (!ip6_route_add(&cfg, GFP_ATOMIC, NULL)) {
+		struct fib6_table *table;
+
+		table = fib6_get_table(dev_net(dev), cfg.fc_table);
+		if (table)
+			table->flags |= RT6_TABLE_HAS_DFLT_ROUTER;
+	}
+
+	return rt6_get_dflt_router(net, gwaddr, dev);
+}
+
+static void __rt6_purge_dflt_routers(struct net *net,
+				     struct fib6_table *table)
+{
+	struct fib6_info *rt;
+
+restart:
+	rcu_read_lock();
+	for_each_fib6_node_rt_rcu(&table->tb6_root) {
+		struct net_device *dev = fib6_info_nh_dev(rt);
+		struct inet6_dev *idev = dev ? __in6_dev_get(dev) : NULL;
+
+		if (rt->fib6_flags & (RTF_DEFAULT | RTF_ADDRCONF) &&
+		    (!idev || idev->cnf.accept_ra != 2) &&
+		    fib6_info_hold_safe(rt)) {
+			rcu_read_unlock();
+			ip6_del_rt(net, rt, false);
+			goto restart;
+		}
+	}
+	rcu_read_unlock();
+
+	table->flags &= ~RT6_TABLE_HAS_DFLT_ROUTER;
+}
+
+void rt6_purge_dflt_routers(struct net *net)
+{
+	struct fib6_table *table;
+	struct hlist_head *head;
+	unsigned int h;
+
+	rcu_read_lock();
+
+	for (h = 0; h < FIB6_TABLE_HASHSZ; h++) {
+		head = &net->ipv6.fib_table_hash[h];
+		hlist_for_each_entry_rcu(table, head, tb6_hlist) {
+			if (table->flags & RT6_TABLE_HAS_DFLT_ROUTER)
+				__rt6_purge_dflt_routers(net, table);
+		}
+	}
+
+	rcu_read_unlock();
+}
+
+static void rtmsg_to_fib6_config(struct net *net,
+				 struct in6_rtmsg *rtmsg,
+				 struct fib6_config *cfg)
+{
+	*cfg = (struct fib6_config){
+		.fc_table = l3mdev_fib_table_by_index(net, rtmsg->rtmsg_ifindex) ?
+			 : RT6_TABLE_MAIN,
+		.fc_ifindex = rtmsg->rtmsg_ifindex,
+		.fc_metric = rtmsg->rtmsg_metric ? : IP6_RT_PRIO_USER,
+		.fc_expires = rtmsg->rtmsg_info,
+		.fc_dst_len = rtmsg->rtmsg_dst_len,
+		.fc_src_len = rtmsg->rtmsg_src_len,
+		.fc_flags = rtmsg->rtmsg_flags,
+		.fc_type = rtmsg->rtmsg_type,
+
+		.fc_nlinfo.nl_net = net,
+
+		.fc_dst = rtmsg->rtmsg_dst,
+		.fc_src = rtmsg->rtmsg_src,
+		.fc_gateway = rtmsg->rtmsg_gateway,
+	};
+}
+
+int ipv6_route_ioctl(struct net *net, unsigned int cmd, struct in6_rtmsg *rtmsg)
+{
+	struct fib6_config cfg;
+	int err;
+
+	if (cmd != SIOCADDRT && cmd != SIOCDELRT)
+		return -EINVAL;
+	if (!ns_capable(net->user_ns, CAP_NET_ADMIN))
+		return -EPERM;
+
+	rtmsg_to_fib6_config(net, rtmsg, &cfg);
+
+	rtnl_lock();
+	switch (cmd) {
+	case SIOCADDRT:
+		err = ip6_route_add(&cfg, GFP_KERNEL, NULL);
+		break;
+	case SIOCDELRT:
+		err = ip6_route_del(&cfg, NULL);
+		break;
+	}
+	rtnl_unlock();
+	return err;
+}
+
+/*
+ *	Drop the packet on the floor
+ */
+
+static int ip6_pkt_drop(struct sk_buff *skb, u8 code, int ipstats_mib_noroutes)
+{
+	struct dst_entry *dst = skb_dst(skb);
+	struct net *net = dev_net(dst->dev);
+	struct inet6_dev *idev;
+	int type;
+
+	if (netif_is_l3_master(skb->dev) ||
+	    dst->dev == net->loopback_dev)
+		idev = __in6_dev_get_safely(dev_get_by_index_rcu(net, IP6CB(skb)->iif));
+	else
+		idev = ip6_dst_idev(dst);
+
+	switch (ipstats_mib_noroutes) {
+	case IPSTATS_MIB_INNOROUTES:
+		type = ipv6_addr_type(&ipv6_hdr(skb)->daddr);
+		if (type == IPV6_ADDR_ANY) {
+			IP6_INC_STATS(net, idev, IPSTATS_MIB_INADDRERRORS);
+			break;
+		}
+		fallthrough;
+	case IPSTATS_MIB_OUTNOROUTES:
+		IP6_INC_STATS(net, idev, ipstats_mib_noroutes);
+		break;
+	}
+
+	/* Start over by dropping the dst for l3mdev case */
+	if (netif_is_l3_master(skb->dev))
+		skb_dst_drop(skb);
+
+	icmpv6_send(skb, ICMPV6_DEST_UNREACH, code, 0);
+	kfree_skb(skb);
+	return 0;
+}
+
+static int ip6_pkt_discard(struct sk_buff *skb)
+{
+	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_INNOROUTES);
+}
+
+static int ip6_pkt_discard_out(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	skb->dev = skb_dst(skb)->dev;
+	return ip6_pkt_drop(skb, ICMPV6_NOROUTE, IPSTATS_MIB_OUTNOROUTES);
+}
+
+static int ip6_pkt_prohibit(struct sk_buff *skb)
+{
+	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_INNOROUTES);
+}
+
+static int ip6_pkt_prohibit_out(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	skb->dev = skb_dst(skb)->dev;
+	return ip6_pkt_drop(skb, ICMPV6_ADM_PROHIBITED, IPSTATS_MIB_OUTNOROUTES);
+}
+
+/*
+ *	Allocate a dst for local (unicast / anycast) address.
+ */
+
+struct fib6_info *addrconf_f6i_alloc(struct net *net,
+				     struct inet6_dev *idev,
+				     const struct in6_addr *addr,
+				     bool anycast, gfp_t gfp_flags)
+{
+	struct fib6_config cfg = {
+		.fc_table = l3mdev_fib_table(idev->dev) ? : RT6_TABLE_LOCAL,
+		.fc_ifindex = idev->dev->ifindex,
+		.fc_flags = RTF_UP | RTF_NONEXTHOP,
+		.fc_dst = *addr,
+		.fc_dst_len = 128,
+		.fc_protocol = RTPROT_KERNEL,
+		.fc_nlinfo.nl_net = net,
+		.fc_ignore_dev_down = true,
+	};
+	struct fib6_info *f6i;
+
+	if (anycast) {
+		cfg.fc_type = RTN_ANYCAST;
+		cfg.fc_flags |= RTF_ANYCAST;
+	} else {
+		cfg.fc_type = RTN_LOCAL;
+		cfg.fc_flags |= RTF_LOCAL;
+	}
+
+	f6i = ip6_route_info_create(&cfg, gfp_flags, NULL);
+	if (!IS_ERR(f6i)) {
+		f6i->dst_nocount = true;
+
+		if (!anycast &&
+		    (net->ipv6.devconf_all->disable_policy ||
+		     idev->cnf.disable_policy))
+			f6i->dst_nopolicy = true;
+	}
+
+	return f6i;
+}
+
+/* remove deleted ip from prefsrc entries */
+struct arg_dev_net_ip {
+	struct net_device *dev;
+	struct net *net;
+	struct in6_addr *addr;
+};
+
+static int fib6_remove_prefsrc(struct fib6_info *rt, void *arg)
+{
+	struct net_device *dev = ((struct arg_dev_net_ip *)arg)->dev;
+	struct net *net = ((struct arg_dev_net_ip *)arg)->net;
+	struct in6_addr *addr = ((struct arg_dev_net_ip *)arg)->addr;
+
+	if (!rt->nh &&
+	    ((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);
+		/* remove prefsrc entry */
+		rt->fib6_prefsrc.plen = 0;
+		spin_unlock_bh(&rt6_exception_lock);
+	}
+	return 0;
+}
+
+void rt6_remove_prefsrc(struct inet6_ifaddr *ifp)
+{
+	struct net *net = dev_net(ifp->idev->dev);
+	struct arg_dev_net_ip adni = {
+		.dev = ifp->idev->dev,
+		.net = net,
+		.addr = &ifp->addr,
+	};
+	fib6_clean_all(net, fib6_remove_prefsrc, &adni);
+}
+
+#define RTF_RA_ROUTER		(RTF_ADDRCONF | RTF_DEFAULT)
+
+/* Remove routers and update dst entries when gateway turn into host. */
+static int fib6_clean_tohost(struct fib6_info *rt, void *arg)
+{
+	struct in6_addr *gateway = (struct in6_addr *)arg;
+	struct fib6_nh *nh;
+
+	/* RA routes do not use nexthops */
+	if (rt->nh)
+		return 0;
+
+	nh = rt->fib6_nh;
+	if (((rt->fib6_flags & RTF_RA_ROUTER) == RTF_RA_ROUTER) &&
+	    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.
+	 */
+	fib6_nh_exceptions_clean_tohost(nh, gateway);
+
+	return 0;
+}
+
+void rt6_clean_tohost(struct net *net, struct in6_addr *gateway)
+{
+	fib6_clean_all(net, fib6_clean_tohost, gateway);
+}
+
+struct arg_netdev_event {
+	const struct net_device *dev;
+	union {
+		unsigned char nh_flags;
+		unsigned long event;
+	};
+};
+
+static struct fib6_info *rt6_multipath_first_sibling(const struct fib6_info *rt)
+{
+	struct fib6_info *iter;
+	struct fib6_node *fn;
+
+	fn = rcu_dereference_protected(rt->fib6_node,
+			lockdep_is_held(&rt->fib6_table->tb6_lock));
+	iter = rcu_dereference_protected(fn->leaf,
+			lockdep_is_held(&rt->fib6_table->tb6_lock));
+	while (iter) {
+		if (iter->fib6_metric == rt->fib6_metric &&
+		    rt6_qualify_for_ecmp(iter))
+			return iter;
+		iter = rcu_dereference_protected(iter->fib6_next,
+				lockdep_is_held(&rt->fib6_table->tb6_lock));
+	}
+
+	return NULL;
+}
+
+/* only called for fib entries with builtin fib6_nh */
+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)))
+		return true;
+
+	return false;
+}
+
+static int rt6_multipath_total_weight(const struct fib6_info *rt)
+{
+	struct fib6_info *iter;
+	int total = 0;
+
+	if (!rt6_is_dead(rt))
+		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;
+	}
+
+	return total;
+}
+
+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;
+		upper_bound = DIV_ROUND_CLOSEST_ULL((u64) (*weight) << 31,
+						    total) - 1;
+	}
+	atomic_set(&rt->fib6_nh->fib_nh_upper_bound, upper_bound);
+}
+
+static void rt6_multipath_upper_bound_set(struct fib6_info *rt, int total)
+{
+	struct fib6_info *iter;
+	int weight = 0;
+
+	rt6_upper_bound_set(rt, &weight, total);
+
+	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
+		rt6_upper_bound_set(iter, &weight, total);
+}
+
+void rt6_multipath_rebalance(struct fib6_info *rt)
+{
+	struct fib6_info *first;
+	int total;
+
+	/* In case the entire multipath route was marked for flushing,
+	 * then there is no need to rebalance upon the removal of every
+	 * sibling route.
+	 */
+	if (!rt->fib6_nsiblings || rt->should_flush)
+		return;
+
+	/* During lookup routes are evaluated in order, so we need to
+	 * make sure upper bounds are assigned from the first sibling
+	 * onwards.
+	 */
+	first = rt6_multipath_first_sibling(rt);
+	if (WARN_ON_ONCE(!first))
+		return;
+
+	total = rt6_multipath_total_weight(first);
+	rt6_multipath_upper_bound_set(first, total);
+}
+
+static int fib6_ifup(struct fib6_info *rt, void *p_arg)
+{
+	const struct arg_netdev_event *arg = p_arg;
+	struct net *net = dev_net(arg->dev);
+
+	if (rt != net->ipv6.fib6_null_entry && !rt->nh &&
+	    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);
+	}
+
+	return 0;
+}
+
+void rt6_sync_up(struct net_device *dev, unsigned char nh_flags)
+{
+	struct arg_netdev_event arg = {
+		.dev = dev,
+		{
+			.nh_flags = nh_flags,
+		},
+	};
+
+	if (nh_flags & RTNH_F_DEAD && netif_carrier_ok(dev))
+		arg.nh_flags |= RTNH_F_LINKDOWN;
+
+	fib6_clean_all(dev_net(dev), fib6_ifup, &arg);
+}
+
+/* only called for fib entries with inline fib6_nh */
+static bool rt6_multipath_uses_dev(const struct fib6_info *rt,
+				   const struct net_device *dev)
+{
+	struct fib6_info *iter;
+
+	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)
+			return true;
+
+	return false;
+}
+
+static void rt6_multipath_flush(struct fib6_info *rt)
+{
+	struct fib6_info *iter;
+
+	rt->should_flush = 1;
+	list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings)
+		iter->should_flush = 1;
+}
+
+static unsigned int rt6_multipath_dead_count(const struct fib6_info *rt,
+					     const struct net_device *down_dev)
+{
+	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)
+		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)
+			dead++;
+
+	return dead;
+}
+
+static void rt6_multipath_nh_flags_set(struct fib6_info *rt,
+				       const struct net_device *dev,
+				       unsigned char nh_flags)
+{
+	struct fib6_info *iter;
+
+	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;
+}
+
+/* called with write lock held for table with rt */
+static int fib6_ifdown(struct fib6_info *rt, void *p_arg)
+{
+	const struct arg_netdev_event *arg = p_arg;
+	const struct net_device *dev = arg->dev;
+	struct net *net = dev_net(dev);
+
+	if (rt == net->ipv6.fib6_null_entry || rt->nh)
+		return 0;
+
+	switch (arg->event) {
+	case NETDEV_UNREGISTER:
+		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;
+		if (rt6_multipath_uses_dev(rt, dev)) {
+			unsigned int count;
+
+			count = rt6_multipath_dead_count(rt, dev);
+			if (rt->fib6_nsiblings + 1 == count) {
+				rt6_multipath_flush(rt);
+				return -1;
+			}
+			rt6_multipath_nh_flags_set(rt, dev, RTNH_F_DEAD |
+						   RTNH_F_LINKDOWN);
+			fib6_update_sernum(net, rt);
+			rt6_multipath_rebalance(rt);
+		}
+		return -2;
+	case NETDEV_CHANGE:
+		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;
+		rt6_multipath_rebalance(rt);
+		break;
+	}
+
+	return 0;
+}
+
+void rt6_sync_down_dev(struct net_device *dev, unsigned long event)
+{
+	struct arg_netdev_event arg = {
+		.dev = dev,
+		{
+			.event = event,
+		},
+	};
+	struct net *net = dev_net(dev);
+
+	if (net->ipv6.sysctl.skip_notify_on_dev_down)
+		fib6_clean_all_skip_notify(net, fib6_ifdown, &arg);
+	else
+		fib6_clean_all(net, fib6_ifdown, &arg);
+}
+
+void rt6_disable_ip(struct net_device *dev, unsigned long event)
+{
+	rt6_sync_down_dev(dev, event);
+	rt6_uncached_list_flush_dev(dev_net(dev), dev);
+	neigh_ifdown(&nd_tbl, dev);
+}
+
+struct rt6_mtu_change_arg {
+	struct net_device *dev;
+	unsigned int mtu;
+	struct fib6_info *f6i;
+};
+
+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;
+
+	/* In IPv6 pmtu discovery is not optional,
+	   so that RTAX_MTU lock cannot disable it.
+	   We still use this lock to block changes
+	   caused by addrconf/ndisc.
+	*/
+
+	idev = __in6_dev_get(arg->dev);
+	if (!idev)
+		return 0;
+
+	if (fib6_metric_locked(f6i, RTAX_MTU))
+		return 0;
+
+	arg->f6i = f6i;
+	if (f6i->nh) {
+		/* fib6_nh_mtu_change only returns 0, so this is safe */
+		return nexthop_for_each_fib6_nh(f6i->nh, fib6_nh_mtu_change,
+						arg);
+	}
+
+	return fib6_nh_mtu_change(f6i->fib6_nh, arg);
+}
+
+void rt6_mtu_change(struct net_device *dev, unsigned int mtu)
+{
+	struct rt6_mtu_change_arg arg = {
+		.dev = dev,
+		.mtu = mtu,
+	};
+
+	fib6_clean_all(dev_net(dev), rt6_mtu_change_route, &arg);
+}
+
+static const struct nla_policy rtm_ipv6_policy[RTA_MAX+1] = {
+	[RTA_UNSPEC]		= { .strict_start_type = RTA_DPORT + 1 },
+	[RTA_GATEWAY]           = { .len = sizeof(struct in6_addr) },
+	[RTA_PREFSRC]		= { .len = sizeof(struct in6_addr) },
+	[RTA_OIF]               = { .type = NLA_U32 },
+	[RTA_IIF]		= { .type = NLA_U32 },
+	[RTA_PRIORITY]          = { .type = NLA_U32 },
+	[RTA_METRICS]           = { .type = NLA_NESTED },
+	[RTA_MULTIPATH]		= { .len = sizeof(struct rtnexthop) },
+	[RTA_PREF]              = { .type = NLA_U8 },
+	[RTA_ENCAP_TYPE]	= { .type = NLA_U16 },
+	[RTA_ENCAP]		= { .type = NLA_NESTED },
+	[RTA_EXPIRES]		= { .type = NLA_U32 },
+	[RTA_UID]		= { .type = NLA_U32 },
+	[RTA_MARK]		= { .type = NLA_U32 },
+	[RTA_TABLE]		= { .type = NLA_U32 },
+	[RTA_IP_PROTO]		= { .type = NLA_U8 },
+	[RTA_SPORT]		= { .type = NLA_U16 },
+	[RTA_DPORT]		= { .type = NLA_U16 },
+	[RTA_NH_ID]		= { .type = NLA_U32 },
+};
+
+static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
+			      struct fib6_config *cfg,
+			      struct netlink_ext_ack *extack)
+{
+	struct rtmsg *rtm;
+	struct nlattr *tb[RTA_MAX+1];
+	unsigned int pref;
+	int err;
+
+	err = nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
+				     rtm_ipv6_policy, extack);
+	if (err < 0)
+		goto errout;
+
+	err = -EINVAL;
+	rtm = nlmsg_data(nlh);
+
+	*cfg = (struct fib6_config){
+		.fc_table = rtm->rtm_table,
+		.fc_dst_len = rtm->rtm_dst_len,
+		.fc_src_len = rtm->rtm_src_len,
+		.fc_flags = RTF_UP,
+		.fc_protocol = rtm->rtm_protocol,
+		.fc_type = rtm->rtm_type,
+
+		.fc_nlinfo.portid = NETLINK_CB(skb).portid,
+		.fc_nlinfo.nlh = nlh,
+		.fc_nlinfo.nl_net = sock_net(skb->sk),
+	};
+
+	if (rtm->rtm_type == RTN_UNREACHABLE ||
+	    rtm->rtm_type == RTN_BLACKHOLE ||
+	    rtm->rtm_type == RTN_PROHIBIT ||
+	    rtm->rtm_type == RTN_THROW)
+		cfg->fc_flags |= RTF_REJECT;
+
+	if (rtm->rtm_type == RTN_LOCAL)
+		cfg->fc_flags |= RTF_LOCAL;
+
+	if (rtm->rtm_flags & RTM_F_CLONED)
+		cfg->fc_flags |= RTF_CACHE;
+
+	cfg->fc_flags |= (rtm->rtm_flags & RTNH_F_ONLINK);
+
+	if (tb[RTA_NH_ID]) {
+		if (tb[RTA_GATEWAY]   || tb[RTA_OIF] ||
+		    tb[RTA_MULTIPATH] || tb[RTA_ENCAP]) {
+			NL_SET_ERR_MSG(extack,
+				       "Nexthop specification and nexthop id are mutually exclusive");
+			goto errout;
+		}
+		cfg->fc_nh_id = nla_get_u32(tb[RTA_NH_ID]);
+	}
+
+	if (tb[RTA_GATEWAY]) {
+		cfg->fc_gateway = nla_get_in6_addr(tb[RTA_GATEWAY]);
+		cfg->fc_flags |= RTF_GATEWAY;
+	}
+	if (tb[RTA_VIA]) {
+		NL_SET_ERR_MSG(extack, "IPv6 does not support RTA_VIA attribute");
+		goto errout;
+	}
+
+	if (tb[RTA_DST]) {
+		int plen = (rtm->rtm_dst_len + 7) >> 3;
+
+		if (nla_len(tb[RTA_DST]) < plen)
+			goto errout;
+
+		nla_memcpy(&cfg->fc_dst, tb[RTA_DST], plen);
+	}
+
+	if (tb[RTA_SRC]) {
+		int plen = (rtm->rtm_src_len + 7) >> 3;
+
+		if (nla_len(tb[RTA_SRC]) < plen)
+			goto errout;
+
+		nla_memcpy(&cfg->fc_src, tb[RTA_SRC], plen);
+	}
+
+	if (tb[RTA_PREFSRC])
+		cfg->fc_prefsrc = nla_get_in6_addr(tb[RTA_PREFSRC]);
+
+	if (tb[RTA_OIF])
+		cfg->fc_ifindex = nla_get_u32(tb[RTA_OIF]);
+
+	if (tb[RTA_PRIORITY])
+		cfg->fc_metric = nla_get_u32(tb[RTA_PRIORITY]);
+
+	if (tb[RTA_METRICS]) {
+		cfg->fc_mx = nla_data(tb[RTA_METRICS]);
+		cfg->fc_mx_len = nla_len(tb[RTA_METRICS]);
+	}
+
+	if (tb[RTA_TABLE])
+		cfg->fc_table = nla_get_u32(tb[RTA_TABLE]);
+
+	if (tb[RTA_MULTIPATH]) {
+		cfg->fc_mp = nla_data(tb[RTA_MULTIPATH]);
+		cfg->fc_mp_len = nla_len(tb[RTA_MULTIPATH]);
+
+		err = lwtunnel_valid_encap_type_attr(cfg->fc_mp,
+						     cfg->fc_mp_len, extack);
+		if (err < 0)
+			goto errout;
+	}
+
+	if (tb[RTA_PREF]) {
+		pref = nla_get_u8(tb[RTA_PREF]);
+		if (pref != ICMPV6_ROUTER_PREF_LOW &&
+		    pref != ICMPV6_ROUTER_PREF_HIGH)
+			pref = ICMPV6_ROUTER_PREF_MEDIUM;
+		cfg->fc_flags |= RTF_PREF(pref);
+	}
+
+	if (tb[RTA_ENCAP])
+		cfg->fc_encap = tb[RTA_ENCAP];
+
+	if (tb[RTA_ENCAP_TYPE]) {
+		cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
+
+		err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
+		if (err < 0)
+			goto errout;
+	}
+
+	if (tb[RTA_EXPIRES]) {
+		unsigned long timeout = addrconf_timeout_fixup(nla_get_u32(tb[RTA_EXPIRES]), HZ);
+
+		if (addrconf_finite_timeout(timeout)) {
+			cfg->fc_expires = jiffies_to_clock_t(timeout * HZ);
+			cfg->fc_flags |= RTF_EXPIRES;
+		}
+	}
+
+	err = 0;
+errout:
+	return err;
+}
+
+struct rt6_nh {
+	struct fib6_info *fib6_info;
+	struct fib6_config r_cfg;
+	struct list_head next;
+};
+
+static int ip6_route_info_append(struct net *net,
+				 struct list_head *rt6_nh_list,
+				 struct fib6_info *rt,
+				 struct fib6_config *r_cfg)
+{
+	struct rt6_nh *nh;
+	int err = -EEXIST;
+
+	list_for_each_entry(nh, rt6_nh_list, next) {
+		/* check if fib6_info already exists */
+		if (rt6_duplicate_nexthop(nh->fib6_info, rt))
+			return err;
+	}
+
+	nh = kzalloc(sizeof(*nh), GFP_KERNEL);
+	if (!nh)
+		return -ENOMEM;
+	nh->fib6_info = rt;
+	memcpy(&nh->r_cfg, r_cfg, sizeof(*r_cfg));
+	list_add_tail(&nh->next, rt6_nh_list);
+
+	return 0;
+}
+
+static void ip6_route_mpath_notify(struct fib6_info *rt,
+				   struct fib6_info *rt_last,
+				   struct nl_info *info,
+				   __u16 nlflags)
+{
+	/* if this is an APPEND route, then rt points to the first route
+	 * inserted and rt_last points to last route inserted. Userspace
+	 * wants a consistent dump of the route which starts at the first
+	 * nexthop. Since sibling routes are always added at the end of
+	 * the list, find the first sibling of the last route appended
+	 */
+	if ((nlflags & NLM_F_APPEND) && rt_last && rt_last->fib6_nsiblings) {
+		rt = list_first_entry(&rt_last->fib6_siblings,
+				      struct fib6_info,
+				      fib6_siblings);
+	}
+
+	if (rt)
+		inet6_rt_notify(RTM_NEWROUTE, rt, info, nlflags);
+}
+
+static bool ip6_route_mpath_should_notify(const struct fib6_info *rt)
+{
+	bool rt_can_ecmp = rt6_qualify_for_ecmp(rt);
+	bool should_notify = false;
+	struct fib6_info *leaf;
+	struct fib6_node *fn;
+
+	rcu_read_lock();
+	fn = rcu_dereference(rt->fib6_node);
+	if (!fn)
+		goto out;
+
+	leaf = rcu_dereference(fn->leaf);
+	if (!leaf)
+		goto out;
+
+	if (rt == leaf ||
+	    (rt_can_ecmp && rt->fib6_metric == leaf->fib6_metric &&
+	     rt6_qualify_for_ecmp(leaf)))
+		should_notify = true;
+out:
+	rcu_read_unlock();
+
+	return should_notify;
+}
+
+static int fib6_gw_from_attr(struct in6_addr *gw, struct nlattr *nla,
+			     struct netlink_ext_ack *extack)
+{
+	if (nla_len(nla) < sizeof(*gw)) {
+		NL_SET_ERR_MSG(extack, "Invalid IPv6 address in RTA_GATEWAY");
+		return -EINVAL;
+	}
+
+	*gw = nla_get_in6_addr(nla);
+
+	return 0;
+}
+
+static int ip6_route_multipath_add(struct fib6_config *cfg,
+				   struct netlink_ext_ack *extack)
+{
+	struct fib6_info *rt_notif = NULL, *rt_last = NULL;
+	struct nl_info *info = &cfg->fc_nlinfo;
+	struct fib6_config r_cfg;
+	struct rtnexthop *rtnh;
+	struct fib6_info *rt;
+	struct rt6_nh *err_nh;
+	struct rt6_nh *nh, *nh_safe;
+	__u16 nlflags;
+	int remaining;
+	int attrlen;
+	int err = 1;
+	int nhn = 0;
+	int replace = (cfg->fc_nlinfo.nlh &&
+		       (cfg->fc_nlinfo.nlh->nlmsg_flags & NLM_F_REPLACE));
+	LIST_HEAD(rt6_nh_list);
+
+	nlflags = replace ? NLM_F_REPLACE : NLM_F_CREATE;
+	if (info->nlh && info->nlh->nlmsg_flags & NLM_F_APPEND)
+		nlflags |= NLM_F_APPEND;
+
+	remaining = cfg->fc_mp_len;
+	rtnh = (struct rtnexthop *)cfg->fc_mp;
+
+	/* Parse a Multipath Entry and build a list (rt6_nh_list) of
+	 * fib6_info structs per nexthop
+	 */
+	while (rtnh_ok(rtnh, remaining)) {
+		memcpy(&r_cfg, cfg, sizeof(*cfg));
+		if (rtnh->rtnh_ifindex)
+			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
+
+		attrlen = rtnh_attrlen(rtnh);
+		if (attrlen > 0) {
+			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
+
+			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
+			if (nla) {
+				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
+							extack);
+				if (err)
+					goto cleanup;
+
+				r_cfg.fc_flags |= RTF_GATEWAY;
+			}
+			r_cfg.fc_encap = nla_find(attrs, attrlen, RTA_ENCAP);
+
+			/* RTA_ENCAP_TYPE length checked in
+			 * lwtunnel_valid_encap_type_attr
+			 */
+			nla = nla_find(attrs, attrlen, RTA_ENCAP_TYPE);
+			if (nla)
+				r_cfg.fc_encap_type = nla_get_u16(nla);
+		}
+
+		r_cfg.fc_flags |= (rtnh->rtnh_flags & RTNH_F_ONLINK);
+		rt = ip6_route_info_create(&r_cfg, GFP_KERNEL, extack);
+		if (IS_ERR(rt)) {
+			err = PTR_ERR(rt);
+			rt = NULL;
+			goto cleanup;
+		}
+		if (!rt6_qualify_for_ecmp(rt)) {
+			err = -EINVAL;
+			NL_SET_ERR_MSG(extack,
+				       "Device only routes can not be added for IPv6 using the multipath API.");
+			fib6_info_release(rt);
+			goto cleanup;
+		}
+
+		rt->fib6_nh->fib_nh_weight = rtnh->rtnh_hops + 1;
+
+		err = ip6_route_info_append(info->nl_net, &rt6_nh_list,
+					    rt, &r_cfg);
+		if (err) {
+			fib6_info_release(rt);
+			goto cleanup;
+		}
+
+		rtnh = rtnh_next(rtnh, &remaining);
+	}
+
+	if (list_empty(&rt6_nh_list)) {
+		NL_SET_ERR_MSG(extack,
+			       "Invalid nexthop configuration - no valid nexthops");
+		return -EINVAL;
+	}
+
+	/* for add and replace send one notification with all nexthops.
+	 * Skip the notification in fib6_add_rt2node and send one with
+	 * the full route when done
+	 */
+	info->skip_notify = 1;
+
+	/* For add and replace, send one notification with all nexthops. For
+	 * append, send one notification with all appended nexthops.
+	 */
+	info->skip_notify_kernel = 1;
+
+	err_nh = NULL;
+	list_for_each_entry(nh, &rt6_nh_list, next) {
+		err = __ip6_ins_rt(nh->fib6_info, info, extack);
+		fib6_info_release(nh->fib6_info);
+
+		if (!err) {
+			/* save reference to last route successfully inserted */
+			rt_last = nh->fib6_info;
+
+			/* save reference to first route for notification */
+			if (!rt_notif)
+				rt_notif = nh->fib6_info;
+		}
+
+		/* nh->fib6_info is used or freed at this point, reset to NULL*/
+		nh->fib6_info = NULL;
+		if (err) {
+			if (replace && nhn)
+				NL_SET_ERR_MSG_MOD(extack,
+						   "multipath route replace failed (check consistency of installed routes)");
+			err_nh = nh;
+			goto add_errout;
+		}
+
+		/* Because each route is added like a single route we remove
+		 * these flags after the first nexthop: if there is a collision,
+		 * we have already failed to add the first nexthop:
+		 * fib6_add_rt2node() has rejected it; when replacing, old
+		 * nexthops have been replaced by first new, the rest should
+		 * be added to it.
+		 */
+		if (cfg->fc_nlinfo.nlh) {
+			cfg->fc_nlinfo.nlh->nlmsg_flags &= ~(NLM_F_EXCL |
+							     NLM_F_REPLACE);
+			cfg->fc_nlinfo.nlh->nlmsg_flags |= NLM_F_CREATE;
+		}
+		nhn++;
+	}
+
+	/* An in-kernel notification should only be sent in case the new
+	 * multipath route is added as the first route in the node, or if
+	 * it was appended to it. We pass 'rt_notif' since it is the first
+	 * sibling and might allow us to skip some checks in the replace case.
+	 */
+	if (ip6_route_mpath_should_notify(rt_notif)) {
+		enum fib_event_type fib_event;
+
+		if (rt_notif->fib6_nsiblings != nhn - 1)
+			fib_event = FIB_EVENT_ENTRY_APPEND;
+		else
+			fib_event = FIB_EVENT_ENTRY_REPLACE;
+
+		err = call_fib6_multipath_entry_notifiers(info->nl_net,
+							  fib_event, rt_notif,
+							  nhn - 1, extack);
+		if (err) {
+			/* Delete all the siblings that were just added */
+			err_nh = NULL;
+			goto add_errout;
+		}
+	}
+
+	/* success ... tell user about new route */
+	ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
+	goto cleanup;
+
+add_errout:
+	/* send notification for routes that were added so that
+	 * the delete notifications sent by ip6_route_del are
+	 * coherent
+	 */
+	if (rt_notif)
+		ip6_route_mpath_notify(rt_notif, rt_last, info, nlflags);
+
+	/* Delete routes that were already added */
+	list_for_each_entry(nh, &rt6_nh_list, next) {
+		if (err_nh == nh)
+			break;
+		ip6_route_del(&nh->r_cfg, extack);
+	}
+
+cleanup:
+	list_for_each_entry_safe(nh, nh_safe, &rt6_nh_list, next) {
+		if (nh->fib6_info)
+			fib6_info_release(nh->fib6_info);
+		list_del(&nh->next);
+		kfree(nh);
+	}
+
+	return err;
+}
+
+static int ip6_route_multipath_del(struct fib6_config *cfg,
+				   struct netlink_ext_ack *extack)
+{
+	struct fib6_config r_cfg;
+	struct rtnexthop *rtnh;
+	int last_err = 0;
+	int remaining;
+	int attrlen;
+	int err;
+
+	remaining = cfg->fc_mp_len;
+	rtnh = (struct rtnexthop *)cfg->fc_mp;
+
+	/* Parse a Multipath Entry */
+	while (rtnh_ok(rtnh, remaining)) {
+		memcpy(&r_cfg, cfg, sizeof(*cfg));
+		if (rtnh->rtnh_ifindex)
+			r_cfg.fc_ifindex = rtnh->rtnh_ifindex;
+
+		attrlen = rtnh_attrlen(rtnh);
+		if (attrlen > 0) {
+			struct nlattr *nla, *attrs = rtnh_attrs(rtnh);
+
+			nla = nla_find(attrs, attrlen, RTA_GATEWAY);
+			if (nla) {
+				err = fib6_gw_from_attr(&r_cfg.fc_gateway, nla,
+							extack);
+				if (err) {
+					last_err = err;
+					goto next_rtnh;
+				}
+
+				r_cfg.fc_flags |= RTF_GATEWAY;
+			}
+		}
+		err = ip6_route_del(&r_cfg, extack);
+		if (err)
+			last_err = err;
+
+next_rtnh:
+		rtnh = rtnh_next(rtnh, &remaining);
+	}
+
+	return last_err;
+}
+
+static int inet6_rtm_delroute(struct sk_buff *skb, struct nlmsghdr *nlh,
+			      struct netlink_ext_ack *extack)
+{
+	struct fib6_config cfg;
+	int err;
+
+	err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
+	if (err < 0)
+		return err;
+
+	if (cfg.fc_nh_id &&
+	    !nexthop_find_by_id(sock_net(skb->sk), cfg.fc_nh_id)) {
+		NL_SET_ERR_MSG(extack, "Nexthop id does not exist");
+		return -EINVAL;
+	}
+
+	if (cfg.fc_mp)
+		return ip6_route_multipath_del(&cfg, extack);
+	else {
+		cfg.fc_delete_all_nh = 1;
+		return ip6_route_del(&cfg, extack);
+	}
+}
+
+static int inet6_rtm_newroute(struct sk_buff *skb, struct nlmsghdr *nlh,
+			      struct netlink_ext_ack *extack)
+{
+	struct fib6_config cfg;
+	int err;
+
+	err = rtm_to_fib6_config(skb, nlh, &cfg, extack);
+	if (err < 0)
+		return err;
+
+	if (cfg.fc_metric == 0)
+		cfg.fc_metric = IP6_RT_PRIO_USER;
+
+	if (cfg.fc_mp)
+		return ip6_route_multipath_add(&cfg, extack);
+	else
+		return ip6_route_add(&cfg, GFP_KERNEL, extack);
+}
+
+/* add the overhead of this fib6_nh to nexthop_len */
+static int rt6_nh_nlmsg_size(struct fib6_nh *nh, void *arg)
+{
+	int *nexthop_len = arg;
+
+	*nexthop_len += nla_total_size(0)	 /* RTA_MULTIPATH */
+		     + NLA_ALIGN(sizeof(struct rtnexthop))
+		     + nla_total_size(16); /* RTA_GATEWAY */
+
+	if (nh->fib_nh_lws) {
+		/* RTA_ENCAP_TYPE */
+		*nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
+		/* RTA_ENCAP */
+		*nexthop_len += nla_total_size(2);
+	}
+
+	return 0;
+}
+
+static size_t rt6_nlmsg_size(struct fib6_info *f6i)
+{
+	int nexthop_len;
+
+	if (f6i->nh) {
+		nexthop_len = nla_total_size(4); /* RTA_NH_ID */
+		nexthop_for_each_fib6_nh(f6i->nh, rt6_nh_nlmsg_size,
+					 &nexthop_len);
+	} else {
+		struct fib6_info *sibling, *next_sibling;
+		struct fib6_nh *nh = f6i->fib6_nh;
+
+		nexthop_len = 0;
+		if (f6i->fib6_nsiblings) {
+			rt6_nh_nlmsg_size(nh, &nexthop_len);
+
+			list_for_each_entry_safe(sibling, next_sibling,
+						 &f6i->fib6_siblings, fib6_siblings) {
+				rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
+			}
+		}
+		nexthop_len += lwtunnel_get_encap_size(nh->fib_nh_lws);
+	}
+
+	return NLMSG_ALIGN(sizeof(struct rtmsg))
+	       + nla_total_size(16) /* RTA_SRC */
+	       + nla_total_size(16) /* RTA_DST */
+	       + nla_total_size(16) /* RTA_GATEWAY */
+	       + nla_total_size(16) /* RTA_PREFSRC */
+	       + nla_total_size(4) /* RTA_TABLE */
+	       + nla_total_size(4) /* RTA_IIF */
+	       + nla_total_size(4) /* RTA_OIF */
+	       + nla_total_size(4) /* RTA_PRIORITY */
+	       + RTAX_MAX * nla_total_size(4) /* RTA_METRICS */
+	       + nla_total_size(sizeof(struct rta_cacheinfo))
+	       + nla_total_size(TCP_CA_NAME_MAX) /* RTAX_CC_ALGO */
+	       + nla_total_size(1) /* RTA_PREF */
+	       + nexthop_len;
+}
+
+static int rt6_fill_node_nexthop(struct sk_buff *skb, struct nexthop *nh,
+				 unsigned char *flags)
+{
+	if (nexthop_is_multipath(nh)) {
+		struct nlattr *mp;
+
+		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
+		if (!mp)
+			goto nla_put_failure;
+
+		if (nexthop_mpath_fill_node(skb, nh, AF_INET6))
+			goto nla_put_failure;
+
+		nla_nest_end(skb, mp);
+	} else {
+		struct fib6_nh *fib6_nh;
+
+		fib6_nh = nexthop_fib6_nh(nh);
+		if (fib_nexthop_info(skb, &fib6_nh->nh_common, AF_INET6,
+				     flags, false) < 0)
+			goto nla_put_failure;
+	}
+
+	return 0;
+
+nla_put_failure:
+	return -EMSGSIZE;
+}
+
+static int rt6_fill_node(struct net *net, struct sk_buff *skb,
+			 struct fib6_info *rt, struct dst_entry *dst,
+			 struct in6_addr *dest, struct in6_addr *src,
+			 int iif, int type, u32 portid, u32 seq,
+			 unsigned int flags)
+{
+	struct rt6_info *rt6 = (struct rt6_info *)dst;
+	struct rt6key *rt6_dst, *rt6_src;
+	u32 *pmetrics, table, rt6_flags;
+	unsigned char nh_flags = 0;
+	struct nlmsghdr *nlh;
+	struct rtmsg *rtm;
+	long expires = 0;
+
+	nlh = nlmsg_put(skb, portid, seq, type, sizeof(*rtm), flags);
+	if (!nlh)
+		return -EMSGSIZE;
+
+	if (rt6) {
+		rt6_dst = &rt6->rt6i_dst;
+		rt6_src = &rt6->rt6i_src;
+		rt6_flags = rt6->rt6i_flags;
+	} else {
+		rt6_dst = &rt->fib6_dst;
+		rt6_src = &rt->fib6_src;
+		rt6_flags = rt->fib6_flags;
+	}
+
+	rtm = nlmsg_data(nlh);
+	rtm->rtm_family = AF_INET6;
+	rtm->rtm_dst_len = rt6_dst->plen;
+	rtm->rtm_src_len = rt6_src->plen;
+	rtm->rtm_tos = 0;
+	if (rt->fib6_table)
+		table = rt->fib6_table->tb6_id;
+	else
+		table = RT6_TABLE_UNSPEC;
+	rtm->rtm_table = table < 256 ? table : RT_TABLE_COMPAT;
+	if (nla_put_u32(skb, RTA_TABLE, table))
+		goto nla_put_failure;
+
+	rtm->rtm_type = rt->fib6_type;
+	rtm->rtm_flags = 0;
+	rtm->rtm_scope = RT_SCOPE_UNIVERSE;
+	rtm->rtm_protocol = rt->fib6_protocol;
+
+	if (rt6_flags & RTF_CACHE)
+		rtm->rtm_flags |= RTM_F_CLONED;
+
+	if (dest) {
+		if (nla_put_in6_addr(skb, RTA_DST, dest))
+			goto nla_put_failure;
+		rtm->rtm_dst_len = 128;
+	} else if (rtm->rtm_dst_len)
+		if (nla_put_in6_addr(skb, RTA_DST, &rt6_dst->addr))
+			goto nla_put_failure;
+#ifdef CONFIG_IPV6_SUBTREES
+	if (src) {
+		if (nla_put_in6_addr(skb, RTA_SRC, src))
+			goto nla_put_failure;
+		rtm->rtm_src_len = 128;
+	} else if (rtm->rtm_src_len &&
+		   nla_put_in6_addr(skb, RTA_SRC, &rt6_src->addr))
+		goto nla_put_failure;
+#endif
+	if (iif) {
+#ifdef CONFIG_IPV6_MROUTE
+		if (ipv6_addr_is_multicast(&rt6_dst->addr)) {
+			int err = ip6mr_get_route(net, skb, rtm, portid);
+
+			if (err == 0)
+				return 0;
+			if (err < 0)
+				goto nla_put_failure;
+		} else
+#endif
+			if (nla_put_u32(skb, RTA_IIF, iif))
+				goto nla_put_failure;
+	} else if (dest) {
+		struct in6_addr saddr_buf;
+		if (ip6_route_get_saddr(net, rt, dest, 0, &saddr_buf) == 0 &&
+		    nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
+			goto nla_put_failure;
+	}
+
+	if (rt->fib6_prefsrc.plen) {
+		struct in6_addr saddr_buf;
+		saddr_buf = rt->fib6_prefsrc.addr;
+		if (nla_put_in6_addr(skb, RTA_PREFSRC, &saddr_buf))
+			goto nla_put_failure;
+	}
+
+	pmetrics = dst ? dst_metrics_ptr(dst) : rt->fib6_metrics->metrics;
+	if (rtnetlink_put_metrics(skb, pmetrics) < 0)
+		goto nla_put_failure;
+
+	if (nla_put_u32(skb, RTA_PRIORITY, rt->fib6_metric))
+		goto nla_put_failure;
+
+	/* For multipath routes, walk the siblings list and add
+	 * each as a nexthop within RTA_MULTIPATH.
+	 */
+	if (rt6) {
+		if (rt6_flags & RTF_GATEWAY &&
+		    nla_put_in6_addr(skb, RTA_GATEWAY, &rt6->rt6i_gateway))
+			goto nla_put_failure;
+
+		if (dst->dev && nla_put_u32(skb, RTA_OIF, dst->dev->ifindex))
+			goto nla_put_failure;
+	} else if (rt->fib6_nsiblings) {
+		struct fib6_info *sibling, *next_sibling;
+		struct nlattr *mp;
+
+		mp = nla_nest_start_noflag(skb, RTA_MULTIPATH);
+		if (!mp)
+			goto nla_put_failure;
+
+		if (fib_add_nexthop(skb, &rt->fib6_nh->nh_common,
+				    rt->fib6_nh->fib_nh_weight, AF_INET6,
+				    0) < 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,
+					    AF_INET6, 0) < 0)
+				goto nla_put_failure;
+		}
+
+		nla_nest_end(skb, mp);
+	} else if (rt->nh) {
+		if (nla_put_u32(skb, RTA_NH_ID, rt->nh->id))
+			goto nla_put_failure;
+
+		if (nexthop_is_blackhole(rt->nh))
+			rtm->rtm_type = RTN_BLACKHOLE;
+
+		if (READ_ONCE(net->ipv4.sysctl_nexthop_compat_mode) &&
+		    rt6_fill_node_nexthop(skb, rt->nh, &nh_flags) < 0)
+			goto nla_put_failure;
+
+		rtm->rtm_flags |= nh_flags;
+	} else {
+		if (fib_nexthop_info(skb, &rt->fib6_nh->nh_common, AF_INET6,
+				     &nh_flags, false) < 0)
+			goto nla_put_failure;
+
+		rtm->rtm_flags |= nh_flags;
+	}
+
+	if (rt6_flags & RTF_EXPIRES) {
+		expires = dst ? dst->expires : rt->expires;
+		expires -= jiffies;
+	}
+
+	if (!dst) {
+		if (rt->offload)
+			rtm->rtm_flags |= RTM_F_OFFLOAD;
+		if (rt->trap)
+			rtm->rtm_flags |= RTM_F_TRAP;
+	}
+
+	if (rtnl_put_cacheinfo(skb, dst, 0, expires, dst ? dst->error : 0) < 0)
+		goto nla_put_failure;
+
+	if (nla_put_u8(skb, RTA_PREF, IPV6_EXTRACT_PREF(rt6_flags)))
+		goto nla_put_failure;
+
+
+	nlmsg_end(skb, nlh);
+	return 0;
+
+nla_put_failure:
+	nlmsg_cancel(skb, nlh);
+	return -EMSGSIZE;
+}
+
+static int fib6_info_nh_uses_dev(struct fib6_nh *nh, void *arg)
+{
+	const struct net_device *dev = arg;
+
+	if (nh->fib_nh_dev == dev)
+		return 1;
+
+	return 0;
+}
+
+static bool fib6_info_uses_dev(const struct fib6_info *f6i,
+			       const struct net_device *dev)
+{
+	if (f6i->nh) {
+		struct net_device *_dev = (struct net_device *)dev;
+
+		return !!nexthop_for_each_fib6_nh(f6i->nh,
+						  fib6_info_nh_uses_dev,
+						  _dev);
+	}
+
+	if (f6i->fib6_nh->fib_nh_dev == dev)
+		return true;
+
+	if (f6i->fib6_nsiblings) {
+		struct fib6_info *sibling, *next_sibling;
+
+		list_for_each_entry_safe(sibling, next_sibling,
+					 &f6i->fib6_siblings, fib6_siblings) {
+			if (sibling->fib6_nh->fib_nh_dev == dev)
+				return true;
+		}
+	}
+
+	return false;
+}
+
+struct fib6_nh_exception_dump_walker {
+	struct rt6_rtnl_dump_arg *dump;
+	struct fib6_info *rt;
+	unsigned int flags;
+	unsigned int skip;
+	unsigned int count;
+};
+
+static int rt6_nh_dump_exceptions(struct fib6_nh *nh, void *arg)
+{
+	struct fib6_nh_exception_dump_walker *w = arg;
+	struct rt6_rtnl_dump_arg *dump = w->dump;
+	struct rt6_exception_bucket *bucket;
+	struct rt6_exception *rt6_ex;
+	int i, err;
+
+	bucket = fib6_nh_get_excptn_bucket(nh, NULL);
+	if (!bucket)
+		return 0;
+
+	for (i = 0; i < FIB6_EXCEPTION_BUCKET_SIZE; i++) {
+		hlist_for_each_entry(rt6_ex, &bucket->chain, hlist) {
+			if (w->skip) {
+				w->skip--;
+				continue;
+			}
+
+			/* Expiration of entries doesn't bump sernum, insertion
+			 * does. Removal is triggered by insertion, so we can
+			 * rely on the fact that if entries change between two
+			 * partial dumps, this node is scanned again completely,
+			 * see rt6_insert_exception() and fib6_dump_table().
+			 *
+			 * Count expired entries we go through as handled
+			 * entries that we'll skip next time, in case of partial
+			 * node dump. Otherwise, if entries expire meanwhile,
+			 * we'll skip the wrong amount.
+			 */
+			if (rt6_check_expired(rt6_ex->rt6i)) {
+				w->count++;
+				continue;
+			}
+
+			err = rt6_fill_node(dump->net, dump->skb, w->rt,
+					    &rt6_ex->rt6i->dst, NULL, NULL, 0,
+					    RTM_NEWROUTE,
+					    NETLINK_CB(dump->cb->skb).portid,
+					    dump->cb->nlh->nlmsg_seq, w->flags);
+			if (err)
+				return err;
+
+			w->count++;
+		}
+		bucket++;
+	}
+
+	return 0;
+}
+
+/* Return -1 if done with node, number of handled routes on partial dump */
+int rt6_dump_route(struct fib6_info *rt, void *p_arg, unsigned int skip)
+{
+	struct rt6_rtnl_dump_arg *arg = (struct rt6_rtnl_dump_arg *) p_arg;
+	struct fib_dump_filter *filter = &arg->filter;
+	unsigned int flags = NLM_F_MULTI;
+	struct net *net = arg->net;
+	int count = 0;
+
+	if (rt == net->ipv6.fib6_null_entry)
+		return -1;
+
+	if ((filter->flags & RTM_F_PREFIX) &&
+	    !(rt->fib6_flags & RTF_PREFIX_RT)) {
+		/* success since this is not a prefix route */
+		return -1;
+	}
+	if (filter->filter_set &&
+	    ((filter->rt_type  && rt->fib6_type != filter->rt_type) ||
+	     (filter->dev      && !fib6_info_uses_dev(rt, filter->dev)) ||
+	     (filter->protocol && rt->fib6_protocol != filter->protocol))) {
+		return -1;
+	}
+
+	if (filter->filter_set ||
+	    !filter->dump_routes || !filter->dump_exceptions) {
+		flags |= NLM_F_DUMP_FILTERED;
+	}
+
+	if (filter->dump_routes) {
+		if (skip) {
+			skip--;
+		} else {
+			if (rt6_fill_node(net, arg->skb, rt, NULL, NULL, NULL,
+					  0, RTM_NEWROUTE,
+					  NETLINK_CB(arg->cb->skb).portid,
+					  arg->cb->nlh->nlmsg_seq, flags)) {
+				return 0;
+			}
+			count++;
+		}
+	}
+
+	if (filter->dump_exceptions) {
+		struct fib6_nh_exception_dump_walker w = { .dump = arg,
+							   .rt = rt,
+							   .flags = flags,
+							   .skip = skip,
+							   .count = 0 };
+		int err;
+
+		rcu_read_lock();
+		if (rt->nh) {
+			err = nexthop_for_each_fib6_nh(rt->nh,
+						       rt6_nh_dump_exceptions,
+						       &w);
+		} else {
+			err = rt6_nh_dump_exceptions(rt->fib6_nh, &w);
+		}
+		rcu_read_unlock();
+
+		if (err)
+			return count += w.count;
+	}
+
+	return -1;
+}
+
+static int inet6_rtm_valid_getroute_req(struct sk_buff *skb,
+					const struct nlmsghdr *nlh,
+					struct nlattr **tb,
+					struct netlink_ext_ack *extack)
+{
+	struct rtmsg *rtm;
+	int i, err;
+
+	if (nlh->nlmsg_len < nlmsg_msg_size(sizeof(*rtm))) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid header for get route request");
+		return -EINVAL;
+	}
+
+	if (!netlink_strict_get_check(skb))
+		return nlmsg_parse_deprecated(nlh, sizeof(*rtm), tb, RTA_MAX,
+					      rtm_ipv6_policy, extack);
+
+	rtm = nlmsg_data(nlh);
+	if ((rtm->rtm_src_len && rtm->rtm_src_len != 128) ||
+	    (rtm->rtm_dst_len && rtm->rtm_dst_len != 128) ||
+	    rtm->rtm_table || rtm->rtm_protocol || rtm->rtm_scope ||
+	    rtm->rtm_type) {
+		NL_SET_ERR_MSG_MOD(extack, "Invalid values in header for get route request");
+		return -EINVAL;
+	}
+	if (rtm->rtm_flags & ~RTM_F_FIB_MATCH) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "Invalid flags for get route request");
+		return -EINVAL;
+	}
+
+	err = nlmsg_parse_deprecated_strict(nlh, sizeof(*rtm), tb, RTA_MAX,
+					    rtm_ipv6_policy, extack);
+	if (err)
+		return err;
+
+	if ((tb[RTA_SRC] && !rtm->rtm_src_len) ||
+	    (tb[RTA_DST] && !rtm->rtm_dst_len)) {
+		NL_SET_ERR_MSG_MOD(extack, "rtm_src_len and rtm_dst_len must be 128 for IPv6");
+		return -EINVAL;
+	}
+
+	for (i = 0; i <= RTA_MAX; i++) {
+		if (!tb[i])
+			continue;
+
+		switch (i) {
+		case RTA_SRC:
+		case RTA_DST:
+		case RTA_IIF:
+		case RTA_OIF:
+		case RTA_MARK:
+		case RTA_UID:
+		case RTA_SPORT:
+		case RTA_DPORT:
+		case RTA_IP_PROTO:
+			break;
+		default:
+			NL_SET_ERR_MSG_MOD(extack, "Unsupported attribute in get route request");
+			return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
+static int inet6_rtm_getroute(struct sk_buff *in_skb, struct nlmsghdr *nlh,
+			      struct netlink_ext_ack *extack)
+{
+	struct net *net = sock_net(in_skb->sk);
+	struct nlattr *tb[RTA_MAX+1];
+	int err, iif = 0, oif = 0;
+	struct fib6_info *from;
+	struct dst_entry *dst;
+	struct rt6_info *rt;
+	struct sk_buff *skb;
+	struct rtmsg *rtm;
+	struct flowi6 fl6 = {};
+	bool fibmatch;
+
+	err = inet6_rtm_valid_getroute_req(in_skb, nlh, tb, extack);
+	if (err < 0)
+		goto errout;
+
+	err = -EINVAL;
+	rtm = nlmsg_data(nlh);
+	fl6.flowlabel = ip6_make_flowinfo(rtm->rtm_tos, 0);
+	fibmatch = !!(rtm->rtm_flags & RTM_F_FIB_MATCH);
+
+	if (tb[RTA_SRC]) {
+		if (nla_len(tb[RTA_SRC]) < sizeof(struct in6_addr))
+			goto errout;
+
+		fl6.saddr = *(struct in6_addr *)nla_data(tb[RTA_SRC]);
+	}
+
+	if (tb[RTA_DST]) {
+		if (nla_len(tb[RTA_DST]) < sizeof(struct in6_addr))
+			goto errout;
+
+		fl6.daddr = *(struct in6_addr *)nla_data(tb[RTA_DST]);
+	}
+
+	if (tb[RTA_IIF])
+		iif = nla_get_u32(tb[RTA_IIF]);
+
+	if (tb[RTA_OIF])
+		oif = nla_get_u32(tb[RTA_OIF]);
+
+	if (tb[RTA_MARK])
+		fl6.flowi6_mark = nla_get_u32(tb[RTA_MARK]);
+
+	if (tb[RTA_UID])
+		fl6.flowi6_uid = make_kuid(current_user_ns(),
+					   nla_get_u32(tb[RTA_UID]));
+	else
+		fl6.flowi6_uid = iif ? INVALID_UID : current_uid();
+
+	if (tb[RTA_SPORT])
+		fl6.fl6_sport = nla_get_be16(tb[RTA_SPORT]);
+
+	if (tb[RTA_DPORT])
+		fl6.fl6_dport = nla_get_be16(tb[RTA_DPORT]);
+
+	if (tb[RTA_IP_PROTO]) {
+		err = rtm_getroute_parse_ip_proto(tb[RTA_IP_PROTO],
+						  &fl6.flowi6_proto, AF_INET6,
+						  extack);
+		if (err)
+			goto errout;
+	}
+
+	if (iif) {
+		struct net_device *dev;
+		int flags = 0;
+
+		rcu_read_lock();
+
+		dev = dev_get_by_index_rcu(net, iif);
+		if (!dev) {
+			rcu_read_unlock();
+			err = -ENODEV;
+			goto errout;
+		}
+
+		fl6.flowi6_iif = iif;
+
+		if (!ipv6_addr_any(&fl6.saddr))
+			flags |= RT6_LOOKUP_F_HAS_SADDR;
+
+		dst = ip6_route_input_lookup(net, dev, &fl6, NULL, flags);
+
+		rcu_read_unlock();
+	} else {
+		fl6.flowi6_oif = oif;
+
+		dst = ip6_route_output(net, NULL, &fl6);
+	}
+
+
+	rt = container_of(dst, struct rt6_info, dst);
+	if (rt->dst.error) {
+		err = rt->dst.error;
+		ip6_rt_put(rt);
+		goto errout;
+	}
+
+	if (rt == net->ipv6.ip6_null_entry) {
+		err = rt->dst.error;
+		ip6_rt_put(rt);
+		goto errout;
+	}
+
+	skb = alloc_skb(NLMSG_GOODSIZE, GFP_KERNEL);
+	if (!skb) {
+		ip6_rt_put(rt);
+		err = -ENOBUFS;
+		goto errout;
+	}
+
+	skb_dst_set(skb, &rt->dst);
+
+	rcu_read_lock();
+	from = rcu_dereference(rt->from);
+	if (from) {
+		if (fibmatch)
+			err = rt6_fill_node(net, skb, from, NULL, NULL, NULL,
+					    iif, RTM_NEWROUTE,
+					    NETLINK_CB(in_skb).portid,
+					    nlh->nlmsg_seq, 0);
+		else
+			err = rt6_fill_node(net, skb, from, dst, &fl6.daddr,
+					    &fl6.saddr, iif, RTM_NEWROUTE,
+					    NETLINK_CB(in_skb).portid,
+					    nlh->nlmsg_seq, 0);
+	} else {
+		err = -ENETUNREACH;
+	}
+	rcu_read_unlock();
+
+	if (err < 0) {
+		kfree_skb(skb);
+		goto errout;
+	}
+
+	err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
+errout:
+	return err;
+}
+
+void inet6_rt_notify(int event, struct fib6_info *rt, struct nl_info *info,
+		     unsigned int nlm_flags)
+{
+	struct sk_buff *skb;
+	struct net *net = info->nl_net;
+	u32 seq;
+	int err;
+
+	err = -ENOBUFS;
+	seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+
+	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
+	if (!skb)
+		goto errout;
+
+	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
+			    event, info->portid, seq, nlm_flags);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
+		    info->nlh, gfp_any());
+	return;
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
+}
+
+void fib6_rt_update(struct net *net, struct fib6_info *rt,
+		    struct nl_info *info)
+{
+	u32 seq = info->nlh ? info->nlh->nlmsg_seq : 0;
+	struct sk_buff *skb;
+	int err = -ENOBUFS;
+
+	/* call_fib6_entry_notifiers will be removed when in-kernel notifier
+	 * is implemented and supported for nexthop objects
+	 */
+	call_fib6_entry_notifiers(net, FIB_EVENT_ENTRY_REPLACE, rt, NULL);
+
+	skb = nlmsg_new(rt6_nlmsg_size(rt), gfp_any());
+	if (!skb)
+		goto errout;
+
+	err = rt6_fill_node(net, skb, rt, NULL, NULL, NULL, 0,
+			    RTM_NEWROUTE, info->portid, seq, NLM_F_REPLACE);
+	if (err < 0) {
+		/* -EMSGSIZE implies BUG in rt6_nlmsg_size() */
+		WARN_ON(err == -EMSGSIZE);
+		kfree_skb(skb);
+		goto errout;
+	}
+	rtnl_notify(skb, net, info->portid, RTNLGRP_IPV6_ROUTE,
+		    info->nlh, gfp_any());
+	return;
+errout:
+	if (err < 0)
+		rtnl_set_sk_err(net, RTNLGRP_IPV6_ROUTE, err);
+}
+
+static int ip6_route_dev_notify(struct notifier_block *this,
+				unsigned long event, void *ptr)
+{
+	struct net_device *dev = netdev_notifier_info_to_dev(ptr);
+	struct net *net = dev_net(dev);
+
+	if (!(dev->flags & IFF_LOOPBACK))
+		return NOTIFY_OK;
+
+	if (event == NETDEV_REGISTER) {
+		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
+		net->ipv6.ip6_prohibit_entry->dst.dev = dev;
+		net->ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(dev);
+		net->ipv6.ip6_blk_hole_entry->dst.dev = dev;
+		net->ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(dev);
+#endif
+	 } else if (event == NETDEV_UNREGISTER &&
+		    dev->reg_state != NETREG_UNREGISTERED) {
+		/* NETDEV_UNREGISTER could be fired for multiple times by
+		 * netdev_wait_allrefs(). Make sure we only call this once.
+		 */
+		in6_dev_put_clear(&net->ipv6.ip6_null_entry->rt6i_idev);
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+		in6_dev_put_clear(&net->ipv6.ip6_prohibit_entry->rt6i_idev);
+		in6_dev_put_clear(&net->ipv6.ip6_blk_hole_entry->rt6i_idev);
+#endif
+	}
+
+	return NOTIFY_OK;
+}
+
+/*
+ *	/proc
+ */
+
+#ifdef CONFIG_PROC_FS
+static int rt6_stats_seq_show(struct seq_file *seq, void *v)
+{
+	struct net *net = (struct net *)seq->private;
+	seq_printf(seq, "%04x %04x %04x %04x %04x %04x %04x\n",
+		   net->ipv6.rt6_stats->fib_nodes,
+		   net->ipv6.rt6_stats->fib_route_nodes,
+		   atomic_read(&net->ipv6.rt6_stats->fib_rt_alloc),
+		   net->ipv6.rt6_stats->fib_rt_entries,
+		   net->ipv6.rt6_stats->fib_rt_cache,
+		   dst_entries_get_slow(&net->ipv6.ip6_dst_ops),
+		   net->ipv6.rt6_stats->fib_discarded_routes);
+
+	return 0;
+}
+#endif	/* CONFIG_PROC_FS */
+
+#ifdef CONFIG_SYSCTL
+
+static int ipv6_sysctl_rtcache_flush(struct ctl_table *ctl, int write,
+			      void *buffer, size_t *lenp, loff_t *ppos)
+{
+	struct net *net;
+	int delay;
+	int ret;
+	if (!write)
+		return -EINVAL;
+
+	net = (struct net *)ctl->extra1;
+	delay = net->ipv6.sysctl.flush_delay;
+	ret = proc_dointvec(ctl, write, buffer, lenp, ppos);
+	if (ret)
+		return ret;
+
+	fib6_run_gc(delay <= 0 ? 0 : (unsigned long)delay, net, delay > 0);
+	return 0;
+}
+
+static struct ctl_table ipv6_route_table_template[] = {
+	{
+		.procname	=	"flush",
+		.data		=	&init_net.ipv6.sysctl.flush_delay,
+		.maxlen		=	sizeof(int),
+		.mode		=	0200,
+		.proc_handler	=	ipv6_sysctl_rtcache_flush
+	},
+	{
+		.procname	=	"gc_thresh",
+		.data		=	&ip6_dst_ops_template.gc_thresh,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec,
+	},
+	{
+		.procname	=	"max_size",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_max_size,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec,
+	},
+	{
+		.procname	=	"gc_min_interval",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec_jiffies,
+	},
+	{
+		.procname	=	"gc_timeout",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_timeout,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec_jiffies,
+	},
+	{
+		.procname	=	"gc_interval",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_interval,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec_jiffies,
+	},
+	{
+		.procname	=	"gc_elasticity",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_elasticity,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec,
+	},
+	{
+		.procname	=	"mtu_expires",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_mtu_expires,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec_jiffies,
+	},
+	{
+		.procname	=	"min_adv_mss",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_min_advmss,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec,
+	},
+	{
+		.procname	=	"gc_min_interval_ms",
+		.data		=	&init_net.ipv6.sysctl.ip6_rt_gc_min_interval,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec_ms_jiffies,
+	},
+	{
+		.procname	=	"skip_notify_on_dev_down",
+		.data		=	&init_net.ipv6.sysctl.skip_notify_on_dev_down,
+		.maxlen		=	sizeof(int),
+		.mode		=	0644,
+		.proc_handler	=	proc_dointvec_minmax,
+		.extra1		=	SYSCTL_ZERO,
+		.extra2		=	SYSCTL_ONE,
+	},
+	{ }
+};
+
+struct ctl_table * __net_init ipv6_route_sysctl_init(struct net *net)
+{
+	struct ctl_table *table;
+
+	table = kmemdup(ipv6_route_table_template,
+			sizeof(ipv6_route_table_template),
+			GFP_KERNEL);
+
+	if (table) {
+		table[0].data = &net->ipv6.sysctl.flush_delay;
+		table[0].extra1 = net;
+		table[1].data = &net->ipv6.ip6_dst_ops.gc_thresh;
+		table[2].data = &net->ipv6.sysctl.ip6_rt_max_size;
+		table[3].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
+		table[4].data = &net->ipv6.sysctl.ip6_rt_gc_timeout;
+		table[5].data = &net->ipv6.sysctl.ip6_rt_gc_interval;
+		table[6].data = &net->ipv6.sysctl.ip6_rt_gc_elasticity;
+		table[7].data = &net->ipv6.sysctl.ip6_rt_mtu_expires;
+		table[8].data = &net->ipv6.sysctl.ip6_rt_min_advmss;
+		table[9].data = &net->ipv6.sysctl.ip6_rt_gc_min_interval;
+		table[10].data = &net->ipv6.sysctl.skip_notify_on_dev_down;
+
+		/* Don't export sysctls to unprivileged users */
+		if (net->user_ns != &init_user_ns)
+			table[0].procname = NULL;
+	}
+
+	return table;
+}
+#endif
+
+static int __net_init ip6_route_net_init(struct net *net)
+{
+	int ret = -ENOMEM;
+
+	memcpy(&net->ipv6.ip6_dst_ops, &ip6_dst_ops_template,
+	       sizeof(net->ipv6.ip6_dst_ops));
+
+	if (dst_entries_init(&net->ipv6.ip6_dst_ops) < 0)
+		goto out_ip6_dst_ops;
+
+	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),
+					   GFP_KERNEL);
+	if (!net->ipv6.ip6_null_entry)
+		goto out_fib6_null_entry;
+	net->ipv6.ip6_null_entry->dst.ops = &net->ipv6.ip6_dst_ops;
+	dst_init_metrics(&net->ipv6.ip6_null_entry->dst,
+			 ip6_template_metrics, true);
+	INIT_LIST_HEAD(&net->ipv6.ip6_null_entry->rt6i_uncached);
+
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+	net->ipv6.fib6_has_custom_rules = false;
+	net->ipv6.ip6_prohibit_entry = kmemdup(&ip6_prohibit_entry_template,
+					       sizeof(*net->ipv6.ip6_prohibit_entry),
+					       GFP_KERNEL);
+	if (!net->ipv6.ip6_prohibit_entry)
+		goto out_ip6_null_entry;
+	net->ipv6.ip6_prohibit_entry->dst.ops = &net->ipv6.ip6_dst_ops;
+	dst_init_metrics(&net->ipv6.ip6_prohibit_entry->dst,
+			 ip6_template_metrics, true);
+	INIT_LIST_HEAD(&net->ipv6.ip6_prohibit_entry->rt6i_uncached);
+
+	net->ipv6.ip6_blk_hole_entry = kmemdup(&ip6_blk_hole_entry_template,
+					       sizeof(*net->ipv6.ip6_blk_hole_entry),
+					       GFP_KERNEL);
+	if (!net->ipv6.ip6_blk_hole_entry)
+		goto out_ip6_prohibit_entry;
+	net->ipv6.ip6_blk_hole_entry->dst.ops = &net->ipv6.ip6_dst_ops;
+	dst_init_metrics(&net->ipv6.ip6_blk_hole_entry->dst,
+			 ip6_template_metrics, true);
+	INIT_LIST_HEAD(&net->ipv6.ip6_blk_hole_entry->rt6i_uncached);
+#ifdef CONFIG_IPV6_SUBTREES
+	net->ipv6.fib6_routes_require_src = 0;
+#endif
+#endif
+
+	net->ipv6.sysctl.flush_delay = 0;
+	net->ipv6.sysctl.ip6_rt_max_size = INT_MAX;
+	net->ipv6.sysctl.ip6_rt_gc_min_interval = HZ / 2;
+	net->ipv6.sysctl.ip6_rt_gc_timeout = 60*HZ;
+	net->ipv6.sysctl.ip6_rt_gc_interval = 30*HZ;
+	net->ipv6.sysctl.ip6_rt_gc_elasticity = 9;
+	net->ipv6.sysctl.ip6_rt_mtu_expires = 10*60*HZ;
+	net->ipv6.sysctl.ip6_rt_min_advmss = IPV6_MIN_MTU - 20 - 40;
+	net->ipv6.sysctl.skip_notify_on_dev_down = 0;
+
+	atomic_set(&net->ipv6.ip6_rt_gc_expire, 30*HZ);
+
+	ret = 0;
+out:
+	return ret;
+
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+out_ip6_prohibit_entry:
+	kfree(net->ipv6.ip6_prohibit_entry);
+out_ip6_null_entry:
+	kfree(net->ipv6.ip6_null_entry);
+#endif
+out_fib6_null_entry:
+	kfree(net->ipv6.fib6_null_entry);
+out_ip6_dst_entries:
+	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
+out_ip6_dst_ops:
+	goto out;
+}
+
+static void __net_exit ip6_route_net_exit(struct net *net)
+{
+	kfree(net->ipv6.fib6_null_entry);
+	kfree(net->ipv6.ip6_null_entry);
+#ifdef CONFIG_IPV6_MULTIPLE_TABLES
+	kfree(net->ipv6.ip6_prohibit_entry);
+	kfree(net->ipv6.ip6_blk_hole_entry);
+#endif
+	dst_entries_destroy(&net->ipv6.ip6_dst_ops);
+}
+
+static int __net_init ip6_route_net_init_late(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+	if (!proc_create_net("ipv6_route", 0, net->proc_net,
+			     &ipv6_route_seq_ops,
+			     sizeof(struct ipv6_route_iter)))
+		return -ENOMEM;
+
+	if (!proc_create_net_single("rt6_stats", 0444, net->proc_net,
+				    rt6_stats_seq_show, NULL)) {
+		remove_proc_entry("ipv6_route", net->proc_net);
+		return -ENOMEM;
+	}
+#endif
+	return 0;
+}
+
+static void __net_exit ip6_route_net_exit_late(struct net *net)
+{
+#ifdef CONFIG_PROC_FS
+	remove_proc_entry("ipv6_route", net->proc_net);
+	remove_proc_entry("rt6_stats", net->proc_net);
+#endif
+}
+
+static struct pernet_operations ip6_route_net_ops = {
+	.init = ip6_route_net_init,
+	.exit = ip6_route_net_exit,
+};
+
+static int __net_init ipv6_inetpeer_init(struct net *net)
+{
+	struct inet_peer_base *bp = kmalloc(sizeof(*bp), GFP_KERNEL);
+
+	if (!bp)
+		return -ENOMEM;
+	inet_peer_base_init(bp);
+	net->ipv6.peers = bp;
+	return 0;
+}
+
+static void __net_exit ipv6_inetpeer_exit(struct net *net)
+{
+	struct inet_peer_base *bp = net->ipv6.peers;
+
+	net->ipv6.peers = NULL;
+	inetpeer_invalidate_tree(bp);
+	kfree(bp);
+}
+
+static struct pernet_operations ipv6_inetpeer_ops = {
+	.init	=	ipv6_inetpeer_init,
+	.exit	=	ipv6_inetpeer_exit,
+};
+
+static struct pernet_operations ip6_route_net_late_ops = {
+	.init = ip6_route_net_init_late,
+	.exit = ip6_route_net_exit_late,
+};
+
+static struct notifier_block ip6_route_dev_notifier = {
+	.notifier_call = ip6_route_dev_notify,
+	.priority = ADDRCONF_NOTIFY_PRIORITY - 10,
+};
+
+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.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
+	init_net.ipv6.ip6_prohibit_entry->dst.dev = init_net.loopback_dev;
+	init_net.ipv6.ip6_prohibit_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
+	init_net.ipv6.ip6_blk_hole_entry->dst.dev = init_net.loopback_dev;
+	init_net.ipv6.ip6_blk_hole_entry->rt6i_idev = in6_dev_get(init_net.loopback_dev);
+  #endif
+}
+
+#if IS_BUILTIN(CONFIG_IPV6)
+#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+DEFINE_BPF_ITER_FUNC(ipv6_route, struct bpf_iter_meta *meta, struct fib6_info *rt)
+
+BTF_ID_LIST(btf_fib6_info_id)
+BTF_ID(struct, fib6_info)
+
+static const struct bpf_iter_seq_info ipv6_route_seq_info = {
+	.seq_ops		= &ipv6_route_seq_ops,
+	.init_seq_private	= bpf_iter_init_seq_net,
+	.fini_seq_private	= bpf_iter_fini_seq_net,
+	.seq_priv_size		= sizeof(struct ipv6_route_iter),
+};
+
+static struct bpf_iter_reg ipv6_route_reg_info = {
+	.target			= "ipv6_route",
+	.ctx_arg_info_size	= 1,
+	.ctx_arg_info		= {
+		{ offsetof(struct bpf_iter__ipv6_route, rt),
+		  PTR_TO_BTF_ID_OR_NULL },
+	},
+	.seq_info		= &ipv6_route_seq_info,
+};
+
+static int __init bpf_iter_register(void)
+{
+	ipv6_route_reg_info.ctx_arg_info[0].btf_id = *btf_fib6_info_id;
+	return bpf_iter_reg_target(&ipv6_route_reg_info);
+}
+
+static void bpf_iter_unregister(void)
+{
+	bpf_iter_unreg_target(&ipv6_route_reg_info);
+}
+#endif
+#endif
+
+int __init ip6_route_init(void)
+{
+	int ret;
+	int cpu;
+
+	ret = -ENOMEM;
+	ip6_dst_ops_template.kmem_cachep =
+		kmem_cache_create("ip6_dst_cache", sizeof(struct rt6_info), 0,
+				  SLAB_HWCACHE_ALIGN, NULL);
+	if (!ip6_dst_ops_template.kmem_cachep)
+		goto out;
+
+	ret = dst_entries_init(&ip6_dst_blackhole_ops);
+	if (ret)
+		goto out_kmem_cache;
+
+	ret = register_pernet_subsys(&ipv6_inetpeer_ops);
+	if (ret)
+		goto out_dst_entries;
+
+	ret = register_pernet_subsys(&ip6_route_net_ops);
+	if (ret)
+		goto out_register_inetpeer;
+
+	ip6_dst_blackhole_ops.kmem_cachep = ip6_dst_ops_template.kmem_cachep;
+
+	ret = fib6_init();
+	if (ret)
+		goto out_register_subsys;
+
+	ret = xfrm6_init();
+	if (ret)
+		goto out_fib6_init;
+
+	ret = fib6_rules_init();
+	if (ret)
+		goto xfrm6_init;
+
+	ret = register_pernet_subsys(&ip6_route_net_late_ops);
+	if (ret)
+		goto fib6_rules_init;
+
+	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_NEWROUTE,
+				   inet6_rtm_newroute, NULL, 0);
+	if (ret < 0)
+		goto out_register_late_subsys;
+
+	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_DELROUTE,
+				   inet6_rtm_delroute, NULL, 0);
+	if (ret < 0)
+		goto out_register_late_subsys;
+
+	ret = rtnl_register_module(THIS_MODULE, PF_INET6, RTM_GETROUTE,
+				   inet6_rtm_getroute, NULL,
+				   RTNL_FLAG_DOIT_UNLOCKED);
+	if (ret < 0)
+		goto out_register_late_subsys;
+
+	ret = register_netdevice_notifier(&ip6_route_dev_notifier);
+	if (ret)
+		goto out_register_late_subsys;
+
+#if IS_BUILTIN(CONFIG_IPV6)
+#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+	ret = bpf_iter_register();
+	if (ret)
+		goto out_register_late_subsys;
+#endif
+#endif
+
+	for_each_possible_cpu(cpu) {
+		struct uncached_list *ul = per_cpu_ptr(&rt6_uncached_list, cpu);
+
+		INIT_LIST_HEAD(&ul->head);
+		spin_lock_init(&ul->lock);
+	}
+
+out:
+	return ret;
+
+out_register_late_subsys:
+	rtnl_unregister_all(PF_INET6);
+	unregister_pernet_subsys(&ip6_route_net_late_ops);
+fib6_rules_init:
+	fib6_rules_cleanup();
+xfrm6_init:
+	xfrm6_fini();
+out_fib6_init:
+	fib6_gc_cleanup();
+out_register_subsys:
+	unregister_pernet_subsys(&ip6_route_net_ops);
+out_register_inetpeer:
+	unregister_pernet_subsys(&ipv6_inetpeer_ops);
+out_dst_entries:
+	dst_entries_destroy(&ip6_dst_blackhole_ops);
+out_kmem_cache:
+	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
+	goto out;
+}
+
+void ip6_route_cleanup(void)
+{
+#if IS_BUILTIN(CONFIG_IPV6)
+#if defined(CONFIG_BPF_SYSCALL) && defined(CONFIG_PROC_FS)
+	bpf_iter_unregister();
+#endif
+#endif
+	unregister_netdevice_notifier(&ip6_route_dev_notifier);
+	unregister_pernet_subsys(&ip6_route_net_late_ops);
+	fib6_rules_cleanup();
+	xfrm6_fini();
+	fib6_gc_cleanup();
+	unregister_pernet_subsys(&ipv6_inetpeer_ops);
+	unregister_pernet_subsys(&ip6_route_net_ops);
+	dst_entries_destroy(&ip6_dst_blackhole_ops);
+	kmem_cache_destroy(ip6_dst_ops_template.kmem_cachep);
+}