Adding upstream version 5.10.209.upstream/5.10.209

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

1 files changed, 11348 insertions, 0 deletions

diff --git a/net/core/dev.c b/net/core/dev.c
new file mode 100644
index 000000000..fc881d60a
--- /dev/null
+++ b/net/core/dev.c
@@ -0,0 +1,11348 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *      NET3    Protocol independent device support routines.
+ *
+ *	Derived from the non IP parts of dev.c 1.0.19
+ *              Authors:	Ross Biro
+ *				Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
+ *				Mark Evans, <evansmp@uhura.aston.ac.uk>
+ *
+ *	Additional Authors:
+ *		Florian la Roche <rzsfl@rz.uni-sb.de>
+ *		Alan Cox <gw4pts@gw4pts.ampr.org>
+ *		David Hinds <dahinds@users.sourceforge.net>
+ *		Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
+ *		Adam Sulmicki <adam@cfar.umd.edu>
+ *              Pekka Riikonen <priikone@poesidon.pspt.fi>
+ *
+ *	Changes:
+ *              D.J. Barrow     :       Fixed bug where dev->refcnt gets set
+ *                                      to 2 if register_netdev gets called
+ *                                      before net_dev_init & also removed a
+ *                                      few lines of code in the process.
+ *		Alan Cox	:	device private ioctl copies fields back.
+ *		Alan Cox	:	Transmit queue code does relevant
+ *					stunts to keep the queue safe.
+ *		Alan Cox	:	Fixed double lock.
+ *		Alan Cox	:	Fixed promisc NULL pointer trap
+ *		????????	:	Support the full private ioctl range
+ *		Alan Cox	:	Moved ioctl permission check into
+ *					drivers
+ *		Tim Kordas	:	SIOCADDMULTI/SIOCDELMULTI
+ *		Alan Cox	:	100 backlog just doesn't cut it when
+ *					you start doing multicast video 8)
+ *		Alan Cox	:	Rewrote net_bh and list manager.
+ *              Alan Cox        :       Fix ETH_P_ALL echoback lengths.
+ *		Alan Cox	:	Took out transmit every packet pass
+ *					Saved a few bytes in the ioctl handler
+ *		Alan Cox	:	Network driver sets packet type before
+ *					calling netif_rx. Saves a function
+ *					call a packet.
+ *		Alan Cox	:	Hashed net_bh()
+ *		Richard Kooijman:	Timestamp fixes.
+ *		Alan Cox	:	Wrong field in SIOCGIFDSTADDR
+ *		Alan Cox	:	Device lock protection.
+ *              Alan Cox        :       Fixed nasty side effect of device close
+ *					changes.
+ *		Rudi Cilibrasi	:	Pass the right thing to
+ *					set_mac_address()
+ *		Dave Miller	:	32bit quantity for the device lock to
+ *					make it work out on a Sparc.
+ *		Bjorn Ekwall	:	Added KERNELD hack.
+ *		Alan Cox	:	Cleaned up the backlog initialise.
+ *		Craig Metz	:	SIOCGIFCONF fix if space for under
+ *					1 device.
+ *	    Thomas Bogendoerfer :	Return ENODEV for dev_open, if there
+ *					is no device open function.
+ *		Andi Kleen	:	Fix error reporting for SIOCGIFCONF
+ *	    Michael Chastain	:	Fix signed/unsigned for SIOCGIFCONF
+ *		Cyrus Durgin	:	Cleaned for KMOD
+ *		Adam Sulmicki   :	Bug Fix : Network Device Unload
+ *					A network device unload needs to purge
+ *					the backlog queue.
+ *	Paul Rusty Russell	:	SIOCSIFNAME
+ *              Pekka Riikonen  :	Netdev boot-time settings code
+ *              Andrew Morton   :       Make unregister_netdevice wait
+ *                                      indefinitely on dev->refcnt
+ *              J Hadi Salim    :       - Backlog queue sampling
+ *				        - netif_rx() feedback
+ */
+
+#include <linux/uaccess.h>
+#include <linux/bitops.h>
+#include <linux/capability.h>
+#include <linux/cpu.h>
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/hash.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/sched/mm.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/if_ether.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/ethtool.h>
+#include <linux/skbuff.h>
+#include <linux/bpf.h>
+#include <linux/bpf_trace.h>
+#include <net/net_namespace.h>
+#include <net/sock.h>
+#include <net/busy_poll.h>
+#include <linux/rtnetlink.h>
+#include <linux/stat.h>
+#include <net/dsa.h>
+#include <net/dst.h>
+#include <net/dst_metadata.h>
+#include <net/pkt_sched.h>
+#include <net/pkt_cls.h>
+#include <net/checksum.h>
+#include <net/xfrm.h>
+#include <linux/highmem.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netpoll.h>
+#include <linux/rcupdate.h>
+#include <linux/delay.h>
+#include <net/iw_handler.h>
+#include <asm/current.h>
+#include <linux/audit.h>
+#include <linux/dmaengine.h>
+#include <linux/err.h>
+#include <linux/ctype.h>
+#include <linux/if_arp.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <net/ip.h>
+#include <net/mpls.h>
+#include <linux/ipv6.h>
+#include <linux/in.h>
+#include <linux/jhash.h>
+#include <linux/random.h>
+#include <trace/events/napi.h>
+#include <trace/events/net.h>
+#include <trace/events/skb.h>
+#include <linux/inetdevice.h>
+#include <linux/cpu_rmap.h>
+#include <linux/static_key.h>
+#include <linux/hashtable.h>
+#include <linux/vmalloc.h>
+#include <linux/if_macvlan.h>
+#include <linux/errqueue.h>
+#include <linux/hrtimer.h>
+#include <linux/netfilter_ingress.h>
+#include <linux/crash_dump.h>
+#include <linux/sctp.h>
+#include <net/udp_tunnel.h>
+#include <linux/net_namespace.h>
+#include <linux/indirect_call_wrapper.h>
+#include <net/devlink.h>
+#include <linux/pm_runtime.h>
+#include <linux/prandom.h>
+
+#include "net-sysfs.h"
+
+#define MAX_GRO_SKBS 8
+
+/* This should be increased if a protocol with a bigger head is added. */
+#define GRO_MAX_HEAD (MAX_HEADER + 128)
+
+static DEFINE_SPINLOCK(ptype_lock);
+static DEFINE_SPINLOCK(offload_lock);
+struct list_head ptype_base[PTYPE_HASH_SIZE] __read_mostly;
+struct list_head ptype_all __read_mostly;	/* Taps */
+static struct list_head offload_base __read_mostly;
+
+static int netif_rx_internal(struct sk_buff *skb);
+static int call_netdevice_notifiers_info(unsigned long val,
+					 struct netdev_notifier_info *info);
+static int call_netdevice_notifiers_extack(unsigned long val,
+					   struct net_device *dev,
+					   struct netlink_ext_ack *extack);
+static struct napi_struct *napi_by_id(unsigned int napi_id);
+
+/*
+ * The @dev_base_head list is protected by @dev_base_lock and the rtnl
+ * semaphore.
+ *
+ * Pure readers hold dev_base_lock for reading, or rcu_read_lock()
+ *
+ * Writers must hold the rtnl semaphore while they loop through the
+ * dev_base_head list, and hold dev_base_lock for writing when they do the
+ * actual updates.  This allows pure readers to access the list even
+ * while a writer is preparing to update it.
+ *
+ * To put it another way, dev_base_lock is held for writing only to
+ * protect against pure readers; the rtnl semaphore provides the
+ * protection against other writers.
+ *
+ * See, for example usages, register_netdevice() and
+ * unregister_netdevice(), which must be called with the rtnl
+ * semaphore held.
+ */
+DEFINE_RWLOCK(dev_base_lock);
+EXPORT_SYMBOL(dev_base_lock);
+
+static DEFINE_MUTEX(ifalias_mutex);
+
+/* protects napi_hash addition/deletion and napi_gen_id */
+static DEFINE_SPINLOCK(napi_hash_lock);
+
+static unsigned int napi_gen_id = NR_CPUS;
+static DEFINE_READ_MOSTLY_HASHTABLE(napi_hash, 8);
+
+static DECLARE_RWSEM(devnet_rename_sem);
+
+static inline void dev_base_seq_inc(struct net *net)
+{
+	while (++net->dev_base_seq == 0)
+		;
+}
+
+static inline struct hlist_head *dev_name_hash(struct net *net, const char *name)
+{
+	unsigned int hash = full_name_hash(net, name, strnlen(name, IFNAMSIZ));
+
+	return &net->dev_name_head[hash_32(hash, NETDEV_HASHBITS)];
+}
+
+static inline struct hlist_head *dev_index_hash(struct net *net, int ifindex)
+{
+	return &net->dev_index_head[ifindex & (NETDEV_HASHENTRIES - 1)];
+}
+
+static inline void rps_lock(struct softnet_data *sd)
+{
+#ifdef CONFIG_RPS
+	spin_lock(&sd->input_pkt_queue.lock);
+#endif
+}
+
+static inline void rps_unlock(struct softnet_data *sd)
+{
+#ifdef CONFIG_RPS
+	spin_unlock(&sd->input_pkt_queue.lock);
+#endif
+}
+
+static struct netdev_name_node *netdev_name_node_alloc(struct net_device *dev,
+						       const char *name)
+{
+	struct netdev_name_node *name_node;
+
+	name_node = kmalloc(sizeof(*name_node), GFP_KERNEL);
+	if (!name_node)
+		return NULL;
+	INIT_HLIST_NODE(&name_node->hlist);
+	name_node->dev = dev;
+	name_node->name = name;
+	return name_node;
+}
+
+static struct netdev_name_node *
+netdev_name_node_head_alloc(struct net_device *dev)
+{
+	struct netdev_name_node *name_node;
+
+	name_node = netdev_name_node_alloc(dev, dev->name);
+	if (!name_node)
+		return NULL;
+	INIT_LIST_HEAD(&name_node->list);
+	return name_node;
+}
+
+static void netdev_name_node_free(struct netdev_name_node *name_node)
+{
+	kfree(name_node);
+}
+
+static void netdev_name_node_add(struct net *net,
+				 struct netdev_name_node *name_node)
+{
+	hlist_add_head_rcu(&name_node->hlist,
+			   dev_name_hash(net, name_node->name));
+}
+
+static void netdev_name_node_del(struct netdev_name_node *name_node)
+{
+	hlist_del_rcu(&name_node->hlist);
+}
+
+static struct netdev_name_node *netdev_name_node_lookup(struct net *net,
+							const char *name)
+{
+	struct hlist_head *head = dev_name_hash(net, name);
+	struct netdev_name_node *name_node;
+
+	hlist_for_each_entry(name_node, head, hlist)
+		if (!strcmp(name_node->name, name))
+			return name_node;
+	return NULL;
+}
+
+static struct netdev_name_node *netdev_name_node_lookup_rcu(struct net *net,
+							    const char *name)
+{
+	struct hlist_head *head = dev_name_hash(net, name);
+	struct netdev_name_node *name_node;
+
+	hlist_for_each_entry_rcu(name_node, head, hlist)
+		if (!strcmp(name_node->name, name))
+			return name_node;
+	return NULL;
+}
+
+int netdev_name_node_alt_create(struct net_device *dev, const char *name)
+{
+	struct netdev_name_node *name_node;
+	struct net *net = dev_net(dev);
+
+	name_node = netdev_name_node_lookup(net, name);
+	if (name_node)
+		return -EEXIST;
+	name_node = netdev_name_node_alloc(dev, name);
+	if (!name_node)
+		return -ENOMEM;
+	netdev_name_node_add(net, name_node);
+	/* The node that holds dev->name acts as a head of per-device list. */
+	list_add_tail(&name_node->list, &dev->name_node->list);
+
+	return 0;
+}
+EXPORT_SYMBOL(netdev_name_node_alt_create);
+
+static void __netdev_name_node_alt_destroy(struct netdev_name_node *name_node)
+{
+	list_del(&name_node->list);
+	netdev_name_node_del(name_node);
+	kfree(name_node->name);
+	netdev_name_node_free(name_node);
+}
+
+int netdev_name_node_alt_destroy(struct net_device *dev, const char *name)
+{
+	struct netdev_name_node *name_node;
+	struct net *net = dev_net(dev);
+
+	name_node = netdev_name_node_lookup(net, name);
+	if (!name_node)
+		return -ENOENT;
+	/* lookup might have found our primary name or a name belonging
+	 * to another device.
+	 */
+	if (name_node == dev->name_node || name_node->dev != dev)
+		return -EINVAL;
+
+	__netdev_name_node_alt_destroy(name_node);
+
+	return 0;
+}
+EXPORT_SYMBOL(netdev_name_node_alt_destroy);
+
+static void netdev_name_node_alt_flush(struct net_device *dev)
+{
+	struct netdev_name_node *name_node, *tmp;
+
+	list_for_each_entry_safe(name_node, tmp, &dev->name_node->list, list)
+		__netdev_name_node_alt_destroy(name_node);
+}
+
+/* Device list insertion */
+static void list_netdevice(struct net_device *dev)
+{
+	struct net *net = dev_net(dev);
+
+	ASSERT_RTNL();
+
+	write_lock_bh(&dev_base_lock);
+	list_add_tail_rcu(&dev->dev_list, &net->dev_base_head);
+	netdev_name_node_add(net, dev->name_node);
+	hlist_add_head_rcu(&dev->index_hlist,
+			   dev_index_hash(net, dev->ifindex));
+	write_unlock_bh(&dev_base_lock);
+
+	dev_base_seq_inc(net);
+}
+
+/* Device list removal
+ * caller must respect a RCU grace period before freeing/reusing dev
+ */
+static void unlist_netdevice(struct net_device *dev)
+{
+	ASSERT_RTNL();
+
+	/* Unlink dev from the device chain */
+	write_lock_bh(&dev_base_lock);
+	list_del_rcu(&dev->dev_list);
+	netdev_name_node_del(dev->name_node);
+	hlist_del_rcu(&dev->index_hlist);
+	write_unlock_bh(&dev_base_lock);
+
+	dev_base_seq_inc(dev_net(dev));
+}
+
+/*
+ *	Our notifier list
+ */
+
+static RAW_NOTIFIER_HEAD(netdev_chain);
+
+/*
+ *	Device drivers call our routines to queue packets here. We empty the
+ *	queue in the local softnet handler.
+ */
+
+DEFINE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);
+EXPORT_PER_CPU_SYMBOL(softnet_data);
+
+#ifdef CONFIG_LOCKDEP
+/*
+ * register_netdevice() inits txq->_xmit_lock and sets lockdep class
+ * according to dev->type
+ */
+static const unsigned short netdev_lock_type[] = {
+	 ARPHRD_NETROM, ARPHRD_ETHER, ARPHRD_EETHER, ARPHRD_AX25,
+	 ARPHRD_PRONET, ARPHRD_CHAOS, ARPHRD_IEEE802, ARPHRD_ARCNET,
+	 ARPHRD_APPLETLK, ARPHRD_DLCI, ARPHRD_ATM, ARPHRD_METRICOM,
+	 ARPHRD_IEEE1394, ARPHRD_EUI64, ARPHRD_INFINIBAND, ARPHRD_SLIP,
+	 ARPHRD_CSLIP, ARPHRD_SLIP6, ARPHRD_CSLIP6, ARPHRD_RSRVD,
+	 ARPHRD_ADAPT, ARPHRD_ROSE, ARPHRD_X25, ARPHRD_HWX25,
+	 ARPHRD_PPP, ARPHRD_CISCO, ARPHRD_LAPB, ARPHRD_DDCMP,
+	 ARPHRD_RAWHDLC, ARPHRD_TUNNEL, ARPHRD_TUNNEL6, ARPHRD_FRAD,
+	 ARPHRD_SKIP, ARPHRD_LOOPBACK, ARPHRD_LOCALTLK, ARPHRD_FDDI,
+	 ARPHRD_BIF, ARPHRD_SIT, ARPHRD_IPDDP, ARPHRD_IPGRE,
+	 ARPHRD_PIMREG, ARPHRD_HIPPI, ARPHRD_ASH, ARPHRD_ECONET,
+	 ARPHRD_IRDA, ARPHRD_FCPP, ARPHRD_FCAL, ARPHRD_FCPL,
+	 ARPHRD_FCFABRIC, ARPHRD_IEEE80211, ARPHRD_IEEE80211_PRISM,
+	 ARPHRD_IEEE80211_RADIOTAP, ARPHRD_PHONET, ARPHRD_PHONET_PIPE,
+	 ARPHRD_IEEE802154, ARPHRD_VOID, ARPHRD_NONE};
+
+static const char *const netdev_lock_name[] = {
+	"_xmit_NETROM", "_xmit_ETHER", "_xmit_EETHER", "_xmit_AX25",
+	"_xmit_PRONET", "_xmit_CHAOS", "_xmit_IEEE802", "_xmit_ARCNET",
+	"_xmit_APPLETLK", "_xmit_DLCI", "_xmit_ATM", "_xmit_METRICOM",
+	"_xmit_IEEE1394", "_xmit_EUI64", "_xmit_INFINIBAND", "_xmit_SLIP",
+	"_xmit_CSLIP", "_xmit_SLIP6", "_xmit_CSLIP6", "_xmit_RSRVD",
+	"_xmit_ADAPT", "_xmit_ROSE", "_xmit_X25", "_xmit_HWX25",
+	"_xmit_PPP", "_xmit_CISCO", "_xmit_LAPB", "_xmit_DDCMP",
+	"_xmit_RAWHDLC", "_xmit_TUNNEL", "_xmit_TUNNEL6", "_xmit_FRAD",
+	"_xmit_SKIP", "_xmit_LOOPBACK", "_xmit_LOCALTLK", "_xmit_FDDI",
+	"_xmit_BIF", "_xmit_SIT", "_xmit_IPDDP", "_xmit_IPGRE",
+	"_xmit_PIMREG", "_xmit_HIPPI", "_xmit_ASH", "_xmit_ECONET",
+	"_xmit_IRDA", "_xmit_FCPP", "_xmit_FCAL", "_xmit_FCPL",
+	"_xmit_FCFABRIC", "_xmit_IEEE80211", "_xmit_IEEE80211_PRISM",
+	"_xmit_IEEE80211_RADIOTAP", "_xmit_PHONET", "_xmit_PHONET_PIPE",
+	"_xmit_IEEE802154", "_xmit_VOID", "_xmit_NONE"};
+
+static struct lock_class_key netdev_xmit_lock_key[ARRAY_SIZE(netdev_lock_type)];
+static struct lock_class_key netdev_addr_lock_key[ARRAY_SIZE(netdev_lock_type)];
+
+static inline unsigned short netdev_lock_pos(unsigned short dev_type)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(netdev_lock_type); i++)
+		if (netdev_lock_type[i] == dev_type)
+			return i;
+	/* the last key is used by default */
+	return ARRAY_SIZE(netdev_lock_type) - 1;
+}
+
+static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
+						 unsigned short dev_type)
+{
+	int i;
+
+	i = netdev_lock_pos(dev_type);
+	lockdep_set_class_and_name(lock, &netdev_xmit_lock_key[i],
+				   netdev_lock_name[i]);
+}
+
+static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
+{
+	int i;
+
+	i = netdev_lock_pos(dev->type);
+	lockdep_set_class_and_name(&dev->addr_list_lock,
+				   &netdev_addr_lock_key[i],
+				   netdev_lock_name[i]);
+}
+#else
+static inline void netdev_set_xmit_lockdep_class(spinlock_t *lock,
+						 unsigned short dev_type)
+{
+}
+
+static inline void netdev_set_addr_lockdep_class(struct net_device *dev)
+{
+}
+#endif
+
+/*******************************************************************************
+ *
+ *		Protocol management and registration routines
+ *
+ *******************************************************************************/
+
+
+/*
+ *	Add a protocol ID to the list. Now that the input handler is
+ *	smarter we can dispense with all the messy stuff that used to be
+ *	here.
+ *
+ *	BEWARE!!! Protocol handlers, mangling input packets,
+ *	MUST BE last in hash buckets and checking protocol handlers
+ *	MUST start from promiscuous ptype_all chain in net_bh.
+ *	It is true now, do not change it.
+ *	Explanation follows: if protocol handler, mangling packet, will
+ *	be the first on list, it is not able to sense, that packet
+ *	is cloned and should be copied-on-write, so that it will
+ *	change it and subsequent readers will get broken packet.
+ *							--ANK (980803)
+ */
+
+static inline struct list_head *ptype_head(const struct packet_type *pt)
+{
+	if (pt->type == htons(ETH_P_ALL))
+		return pt->dev ? &pt->dev->ptype_all : &ptype_all;
+	else
+		return pt->dev ? &pt->dev->ptype_specific :
+				 &ptype_base[ntohs(pt->type) & PTYPE_HASH_MASK];
+}
+
+/**
+ *	dev_add_pack - add packet handler
+ *	@pt: packet type declaration
+ *
+ *	Add a protocol handler to the networking stack. The passed &packet_type
+ *	is linked into kernel lists and may not be freed until it has been
+ *	removed from the kernel lists.
+ *
+ *	This call does not sleep therefore it can not
+ *	guarantee all CPU's that are in middle of receiving packets
+ *	will see the new packet type (until the next received packet).
+ */
+
+void dev_add_pack(struct packet_type *pt)
+{
+	struct list_head *head = ptype_head(pt);
+
+	spin_lock(&ptype_lock);
+	list_add_rcu(&pt->list, head);
+	spin_unlock(&ptype_lock);
+}
+EXPORT_SYMBOL(dev_add_pack);
+
+/**
+ *	__dev_remove_pack	 - remove packet handler
+ *	@pt: packet type declaration
+ *
+ *	Remove a protocol handler that was previously added to the kernel
+ *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
+ *	from the kernel lists and can be freed or reused once this function
+ *	returns.
+ *
+ *      The packet type might still be in use by receivers
+ *	and must not be freed until after all the CPU's have gone
+ *	through a quiescent state.
+ */
+void __dev_remove_pack(struct packet_type *pt)
+{
+	struct list_head *head = ptype_head(pt);
+	struct packet_type *pt1;
+
+	spin_lock(&ptype_lock);
+
+	list_for_each_entry(pt1, head, list) {
+		if (pt == pt1) {
+			list_del_rcu(&pt->list);
+			goto out;
+		}
+	}
+
+	pr_warn("dev_remove_pack: %p not found\n", pt);
+out:
+	spin_unlock(&ptype_lock);
+}
+EXPORT_SYMBOL(__dev_remove_pack);
+
+/**
+ *	dev_remove_pack	 - remove packet handler
+ *	@pt: packet type declaration
+ *
+ *	Remove a protocol handler that was previously added to the kernel
+ *	protocol handlers by dev_add_pack(). The passed &packet_type is removed
+ *	from the kernel lists and can be freed or reused once this function
+ *	returns.
+ *
+ *	This call sleeps to guarantee that no CPU is looking at the packet
+ *	type after return.
+ */
+void dev_remove_pack(struct packet_type *pt)
+{
+	__dev_remove_pack(pt);
+
+	synchronize_net();
+}
+EXPORT_SYMBOL(dev_remove_pack);
+
+
+/**
+ *	dev_add_offload - register offload handlers
+ *	@po: protocol offload declaration
+ *
+ *	Add protocol offload handlers to the networking stack. The passed
+ *	&proto_offload is linked into kernel lists and may not be freed until
+ *	it has been removed from the kernel lists.
+ *
+ *	This call does not sleep therefore it can not
+ *	guarantee all CPU's that are in middle of receiving packets
+ *	will see the new offload handlers (until the next received packet).
+ */
+void dev_add_offload(struct packet_offload *po)
+{
+	struct packet_offload *elem;
+
+	spin_lock(&offload_lock);
+	list_for_each_entry(elem, &offload_base, list) {
+		if (po->priority < elem->priority)
+			break;
+	}
+	list_add_rcu(&po->list, elem->list.prev);
+	spin_unlock(&offload_lock);
+}
+EXPORT_SYMBOL(dev_add_offload);
+
+/**
+ *	__dev_remove_offload	 - remove offload handler
+ *	@po: packet offload declaration
+ *
+ *	Remove a protocol offload handler that was previously added to the
+ *	kernel offload handlers by dev_add_offload(). The passed &offload_type
+ *	is removed from the kernel lists and can be freed or reused once this
+ *	function returns.
+ *
+ *      The packet type might still be in use by receivers
+ *	and must not be freed until after all the CPU's have gone
+ *	through a quiescent state.
+ */
+static void __dev_remove_offload(struct packet_offload *po)
+{
+	struct list_head *head = &offload_base;
+	struct packet_offload *po1;
+
+	spin_lock(&offload_lock);
+
+	list_for_each_entry(po1, head, list) {
+		if (po == po1) {
+			list_del_rcu(&po->list);
+			goto out;
+		}
+	}
+
+	pr_warn("dev_remove_offload: %p not found\n", po);
+out:
+	spin_unlock(&offload_lock);
+}
+
+/**
+ *	dev_remove_offload	 - remove packet offload handler
+ *	@po: packet offload declaration
+ *
+ *	Remove a packet offload handler that was previously added to the kernel
+ *	offload handlers by dev_add_offload(). The passed &offload_type is
+ *	removed from the kernel lists and can be freed or reused once this
+ *	function returns.
+ *
+ *	This call sleeps to guarantee that no CPU is looking at the packet
+ *	type after return.
+ */
+void dev_remove_offload(struct packet_offload *po)
+{
+	__dev_remove_offload(po);
+
+	synchronize_net();
+}
+EXPORT_SYMBOL(dev_remove_offload);
+
+/******************************************************************************
+ *
+ *		      Device Boot-time Settings Routines
+ *
+ ******************************************************************************/
+
+/* Boot time configuration table */
+static struct netdev_boot_setup dev_boot_setup[NETDEV_BOOT_SETUP_MAX];
+
+/**
+ *	netdev_boot_setup_add	- add new setup entry
+ *	@name: name of the device
+ *	@map: configured settings for the device
+ *
+ *	Adds new setup entry to the dev_boot_setup list.  The function
+ *	returns 0 on error and 1 on success.  This is a generic routine to
+ *	all netdevices.
+ */
+static int netdev_boot_setup_add(char *name, struct ifmap *map)
+{
+	struct netdev_boot_setup *s;
+	int i;
+
+	s = dev_boot_setup;
+	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
+		if (s[i].name[0] == '\0' || s[i].name[0] == ' ') {
+			memset(s[i].name, 0, sizeof(s[i].name));
+			strlcpy(s[i].name, name, IFNAMSIZ);
+			memcpy(&s[i].map, map, sizeof(s[i].map));
+			break;
+		}
+	}
+
+	return i >= NETDEV_BOOT_SETUP_MAX ? 0 : 1;
+}
+
+/**
+ * netdev_boot_setup_check	- check boot time settings
+ * @dev: the netdevice
+ *
+ * Check boot time settings for the device.
+ * The found settings are set for the device to be used
+ * later in the device probing.
+ * Returns 0 if no settings found, 1 if they are.
+ */
+int netdev_boot_setup_check(struct net_device *dev)
+{
+	struct netdev_boot_setup *s = dev_boot_setup;
+	int i;
+
+	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++) {
+		if (s[i].name[0] != '\0' && s[i].name[0] != ' ' &&
+		    !strcmp(dev->name, s[i].name)) {
+			dev->irq = s[i].map.irq;
+			dev->base_addr = s[i].map.base_addr;
+			dev->mem_start = s[i].map.mem_start;
+			dev->mem_end = s[i].map.mem_end;
+			return 1;
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL(netdev_boot_setup_check);
+
+
+/**
+ * netdev_boot_base	- get address from boot time settings
+ * @prefix: prefix for network device
+ * @unit: id for network device
+ *
+ * Check boot time settings for the base address of device.
+ * The found settings are set for the device to be used
+ * later in the device probing.
+ * Returns 0 if no settings found.
+ */
+unsigned long netdev_boot_base(const char *prefix, int unit)
+{
+	const struct netdev_boot_setup *s = dev_boot_setup;
+	char name[IFNAMSIZ];
+	int i;
+
+	sprintf(name, "%s%d", prefix, unit);
+
+	/*
+	 * If device already registered then return base of 1
+	 * to indicate not to probe for this interface
+	 */
+	if (__dev_get_by_name(&init_net, name))
+		return 1;
+
+	for (i = 0; i < NETDEV_BOOT_SETUP_MAX; i++)
+		if (!strcmp(name, s[i].name))
+			return s[i].map.base_addr;
+	return 0;
+}
+
+/*
+ * Saves at boot time configured settings for any netdevice.
+ */
+int __init netdev_boot_setup(char *str)
+{
+	int ints[5];
+	struct ifmap map;
+
+	str = get_options(str, ARRAY_SIZE(ints), ints);
+	if (!str || !*str)
+		return 0;
+
+	/* Save settings */
+	memset(&map, 0, sizeof(map));
+	if (ints[0] > 0)
+		map.irq = ints[1];
+	if (ints[0] > 1)
+		map.base_addr = ints[2];
+	if (ints[0] > 2)
+		map.mem_start = ints[3];
+	if (ints[0] > 3)
+		map.mem_end = ints[4];
+
+	/* Add new entry to the list */
+	return netdev_boot_setup_add(str, &map);
+}
+
+__setup("netdev=", netdev_boot_setup);
+
+/*******************************************************************************
+ *
+ *			    Device Interface Subroutines
+ *
+ *******************************************************************************/
+
+/**
+ *	dev_get_iflink	- get 'iflink' value of a interface
+ *	@dev: targeted interface
+ *
+ *	Indicates the ifindex the interface is linked to.
+ *	Physical interfaces have the same 'ifindex' and 'iflink' values.
+ */
+
+int dev_get_iflink(const struct net_device *dev)
+{
+	if (dev->netdev_ops && dev->netdev_ops->ndo_get_iflink)
+		return dev->netdev_ops->ndo_get_iflink(dev);
+
+	return dev->ifindex;
+}
+EXPORT_SYMBOL(dev_get_iflink);
+
+/**
+ *	dev_fill_metadata_dst - Retrieve tunnel egress information.
+ *	@dev: targeted interface
+ *	@skb: The packet.
+ *
+ *	For better visibility of tunnel traffic OVS needs to retrieve
+ *	egress tunnel information for a packet. Following API allows
+ *	user to get this info.
+ */
+int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb)
+{
+	struct ip_tunnel_info *info;
+
+	if (!dev->netdev_ops  || !dev->netdev_ops->ndo_fill_metadata_dst)
+		return -EINVAL;
+
+	info = skb_tunnel_info_unclone(skb);
+	if (!info)
+		return -ENOMEM;
+	if (unlikely(!(info->mode & IP_TUNNEL_INFO_TX)))
+		return -EINVAL;
+
+	return dev->netdev_ops->ndo_fill_metadata_dst(dev, skb);
+}
+EXPORT_SYMBOL_GPL(dev_fill_metadata_dst);
+
+/**
+ *	__dev_get_by_name	- find a device by its name
+ *	@net: the applicable net namespace
+ *	@name: name to find
+ *
+ *	Find an interface by name. Must be called under RTNL semaphore
+ *	or @dev_base_lock. If the name is found a pointer to the device
+ *	is returned. If the name is not found then %NULL is returned. The
+ *	reference counters are not incremented so the caller must be
+ *	careful with locks.
+ */
+
+struct net_device *__dev_get_by_name(struct net *net, const char *name)
+{
+	struct netdev_name_node *node_name;
+
+	node_name = netdev_name_node_lookup(net, name);
+	return node_name ? node_name->dev : NULL;
+}
+EXPORT_SYMBOL(__dev_get_by_name);
+
+/**
+ * dev_get_by_name_rcu	- find a device by its name
+ * @net: the applicable net namespace
+ * @name: name to find
+ *
+ * Find an interface by name.
+ * If the name is found a pointer to the device is returned.
+ * If the name is not found then %NULL is returned.
+ * The reference counters are not incremented so the caller must be
+ * careful with locks. The caller must hold RCU lock.
+ */
+
+struct net_device *dev_get_by_name_rcu(struct net *net, const char *name)
+{
+	struct netdev_name_node *node_name;
+
+	node_name = netdev_name_node_lookup_rcu(net, name);
+	return node_name ? node_name->dev : NULL;
+}
+EXPORT_SYMBOL(dev_get_by_name_rcu);
+
+/**
+ *	dev_get_by_name		- find a device by its name
+ *	@net: the applicable net namespace
+ *	@name: name to find
+ *
+ *	Find an interface by name. This can be called from any
+ *	context and does its own locking. The returned handle has
+ *	the usage count incremented and the caller must use dev_put() to
+ *	release it when it is no longer needed. %NULL is returned if no
+ *	matching device is found.
+ */
+
+struct net_device *dev_get_by_name(struct net *net, const char *name)
+{
+	struct net_device *dev;
+
+	rcu_read_lock();
+	dev = dev_get_by_name_rcu(net, name);
+	if (dev)
+		dev_hold(dev);
+	rcu_read_unlock();
+	return dev;
+}
+EXPORT_SYMBOL(dev_get_by_name);
+
+/**
+ *	__dev_get_by_index - find a device by its ifindex
+ *	@net: the applicable net namespace
+ *	@ifindex: index of device
+ *
+ *	Search for an interface by index. Returns %NULL if the device
+ *	is not found or a pointer to the device. The device has not
+ *	had its reference counter increased so the caller must be careful
+ *	about locking. The caller must hold either the RTNL semaphore
+ *	or @dev_base_lock.
+ */
+
+struct net_device *__dev_get_by_index(struct net *net, int ifindex)
+{
+	struct net_device *dev;
+	struct hlist_head *head = dev_index_hash(net, ifindex);
+
+	hlist_for_each_entry(dev, head, index_hlist)
+		if (dev->ifindex == ifindex)
+			return dev;
+
+	return NULL;
+}
+EXPORT_SYMBOL(__dev_get_by_index);
+
+/**
+ *	dev_get_by_index_rcu - find a device by its ifindex
+ *	@net: the applicable net namespace
+ *	@ifindex: index of device
+ *
+ *	Search for an interface by index. Returns %NULL if the device
+ *	is not found or a pointer to the device. The device has not
+ *	had its reference counter increased so the caller must be careful
+ *	about locking. The caller must hold RCU lock.
+ */
+
+struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex)
+{
+	struct net_device *dev;
+	struct hlist_head *head = dev_index_hash(net, ifindex);
+
+	hlist_for_each_entry_rcu(dev, head, index_hlist)
+		if (dev->ifindex == ifindex)
+			return dev;
+
+	return NULL;
+}
+EXPORT_SYMBOL(dev_get_by_index_rcu);
+
+
+/**
+ *	dev_get_by_index - find a device by its ifindex
+ *	@net: the applicable net namespace
+ *	@ifindex: index of device
+ *
+ *	Search for an interface by index. Returns NULL if the device
+ *	is not found or a pointer to the device. The device returned has
+ *	had a reference added and the pointer is safe until the user calls
+ *	dev_put to indicate they have finished with it.
+ */
+
+struct net_device *dev_get_by_index(struct net *net, int ifindex)
+{
+	struct net_device *dev;
+
+	rcu_read_lock();
+	dev = dev_get_by_index_rcu(net, ifindex);
+	if (dev)
+		dev_hold(dev);
+	rcu_read_unlock();
+	return dev;
+}
+EXPORT_SYMBOL(dev_get_by_index);
+
+/**
+ *	dev_get_by_napi_id - find a device by napi_id
+ *	@napi_id: ID of the NAPI struct
+ *
+ *	Search for an interface by NAPI ID. Returns %NULL if the device
+ *	is not found or a pointer to the device. The device has not had
+ *	its reference counter increased so the caller must be careful
+ *	about locking. The caller must hold RCU lock.
+ */
+
+struct net_device *dev_get_by_napi_id(unsigned int napi_id)
+{
+	struct napi_struct *napi;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	if (napi_id < MIN_NAPI_ID)
+		return NULL;
+
+	napi = napi_by_id(napi_id);
+
+	return napi ? napi->dev : NULL;
+}
+EXPORT_SYMBOL(dev_get_by_napi_id);
+
+/**
+ *	netdev_get_name - get a netdevice name, knowing its ifindex.
+ *	@net: network namespace
+ *	@name: a pointer to the buffer where the name will be stored.
+ *	@ifindex: the ifindex of the interface to get the name from.
+ */
+int netdev_get_name(struct net *net, char *name, int ifindex)
+{
+	struct net_device *dev;
+	int ret;
+
+	down_read(&devnet_rename_sem);
+	rcu_read_lock();
+
+	dev = dev_get_by_index_rcu(net, ifindex);
+	if (!dev) {
+		ret = -ENODEV;
+		goto out;
+	}
+
+	strcpy(name, dev->name);
+
+	ret = 0;
+out:
+	rcu_read_unlock();
+	up_read(&devnet_rename_sem);
+	return ret;
+}
+
+/**
+ *	dev_getbyhwaddr_rcu - find a device by its hardware address
+ *	@net: the applicable net namespace
+ *	@type: media type of device
+ *	@ha: hardware address
+ *
+ *	Search for an interface by MAC address. Returns NULL if the device
+ *	is not found or a pointer to the device.
+ *	The caller must hold RCU or RTNL.
+ *	The returned device has not had its ref count increased
+ *	and the caller must therefore be careful about locking
+ *
+ */
+
+struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
+				       const char *ha)
+{
+	struct net_device *dev;
+
+	for_each_netdev_rcu(net, dev)
+		if (dev->type == type &&
+		    !memcmp(dev->dev_addr, ha, dev->addr_len))
+			return dev;
+
+	return NULL;
+}
+EXPORT_SYMBOL(dev_getbyhwaddr_rcu);
+
+struct net_device *__dev_getfirstbyhwtype(struct net *net, unsigned short type)
+{
+	struct net_device *dev;
+
+	ASSERT_RTNL();
+	for_each_netdev(net, dev)
+		if (dev->type == type)
+			return dev;
+
+	return NULL;
+}
+EXPORT_SYMBOL(__dev_getfirstbyhwtype);
+
+struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type)
+{
+	struct net_device *dev, *ret = NULL;
+
+	rcu_read_lock();
+	for_each_netdev_rcu(net, dev)
+		if (dev->type == type) {
+			dev_hold(dev);
+			ret = dev;
+			break;
+		}
+	rcu_read_unlock();
+	return ret;
+}
+EXPORT_SYMBOL(dev_getfirstbyhwtype);
+
+/**
+ *	__dev_get_by_flags - find any device with given flags
+ *	@net: the applicable net namespace
+ *	@if_flags: IFF_* values
+ *	@mask: bitmask of bits in if_flags to check
+ *
+ *	Search for any interface with the given flags. Returns NULL if a device
+ *	is not found or a pointer to the device. Must be called inside
+ *	rtnl_lock(), and result refcount is unchanged.
+ */
+
+struct net_device *__dev_get_by_flags(struct net *net, unsigned short if_flags,
+				      unsigned short mask)
+{
+	struct net_device *dev, *ret;
+
+	ASSERT_RTNL();
+
+	ret = NULL;
+	for_each_netdev(net, dev) {
+		if (((dev->flags ^ if_flags) & mask) == 0) {
+			ret = dev;
+			break;
+		}
+	}
+	return ret;
+}
+EXPORT_SYMBOL(__dev_get_by_flags);
+
+/**
+ *	dev_valid_name - check if name is okay for network device
+ *	@name: name string
+ *
+ *	Network device names need to be valid file names to
+ *	allow sysfs to work.  We also disallow any kind of
+ *	whitespace.
+ */
+bool dev_valid_name(const char *name)
+{
+	if (*name == '\0')
+		return false;
+	if (strnlen(name, IFNAMSIZ) == IFNAMSIZ)
+		return false;
+	if (!strcmp(name, ".") || !strcmp(name, ".."))
+		return false;
+
+	while (*name) {
+		if (*name == '/' || *name == ':' || isspace(*name))
+			return false;
+		name++;
+	}
+	return true;
+}
+EXPORT_SYMBOL(dev_valid_name);
+
+/**
+ *	__dev_alloc_name - allocate a name for a device
+ *	@net: network namespace to allocate the device name in
+ *	@name: name format string
+ *	@buf:  scratch buffer and result name string
+ *
+ *	Passed a format string - eg "lt%d" it will try and find a suitable
+ *	id. It scans list of devices to build up a free map, then chooses
+ *	the first empty slot. The caller must hold the dev_base or rtnl lock
+ *	while allocating the name and adding the device in order to avoid
+ *	duplicates.
+ *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
+ *	Returns the number of the unit assigned or a negative errno code.
+ */
+
+static int __dev_alloc_name(struct net *net, const char *name, char *buf)
+{
+	int i = 0;
+	const char *p;
+	const int max_netdevices = 8*PAGE_SIZE;
+	unsigned long *inuse;
+	struct net_device *d;
+
+	if (!dev_valid_name(name))
+		return -EINVAL;
+
+	p = strchr(name, '%');
+	if (p) {
+		/*
+		 * Verify the string as this thing may have come from
+		 * the user.  There must be either one "%d" and no other "%"
+		 * characters.
+		 */
+		if (p[1] != 'd' || strchr(p + 2, '%'))
+			return -EINVAL;
+
+		/* Use one page as a bit array of possible slots */
+		inuse = (unsigned long *) get_zeroed_page(GFP_ATOMIC);
+		if (!inuse)
+			return -ENOMEM;
+
+		for_each_netdev(net, d) {
+			struct netdev_name_node *name_node;
+			list_for_each_entry(name_node, &d->name_node->list, list) {
+				if (!sscanf(name_node->name, name, &i))
+					continue;
+				if (i < 0 || i >= max_netdevices)
+					continue;
+
+				/*  avoid cases where sscanf is not exact inverse of printf */
+				snprintf(buf, IFNAMSIZ, name, i);
+				if (!strncmp(buf, name_node->name, IFNAMSIZ))
+					set_bit(i, inuse);
+			}
+			if (!sscanf(d->name, name, &i))
+				continue;
+			if (i < 0 || i >= max_netdevices)
+				continue;
+
+			/*  avoid cases where sscanf is not exact inverse of printf */
+			snprintf(buf, IFNAMSIZ, name, i);
+			if (!strncmp(buf, d->name, IFNAMSIZ))
+				set_bit(i, inuse);
+		}
+
+		i = find_first_zero_bit(inuse, max_netdevices);
+		free_page((unsigned long) inuse);
+	}
+
+	snprintf(buf, IFNAMSIZ, name, i);
+	if (!__dev_get_by_name(net, buf))
+		return i;
+
+	/* It is possible to run out of possible slots
+	 * when the name is long and there isn't enough space left
+	 * for the digits, or if all bits are used.
+	 */
+	return -ENFILE;
+}
+
+static int dev_alloc_name_ns(struct net *net,
+			     struct net_device *dev,
+			     const char *name)
+{
+	char buf[IFNAMSIZ];
+	int ret;
+
+	BUG_ON(!net);
+	ret = __dev_alloc_name(net, name, buf);
+	if (ret >= 0)
+		strlcpy(dev->name, buf, IFNAMSIZ);
+	return ret;
+}
+
+/**
+ *	dev_alloc_name - allocate a name for a device
+ *	@dev: device
+ *	@name: name format string
+ *
+ *	Passed a format string - eg "lt%d" it will try and find a suitable
+ *	id. It scans list of devices to build up a free map, then chooses
+ *	the first empty slot. The caller must hold the dev_base or rtnl lock
+ *	while allocating the name and adding the device in order to avoid
+ *	duplicates.
+ *	Limited to bits_per_byte * page size devices (ie 32K on most platforms).
+ *	Returns the number of the unit assigned or a negative errno code.
+ */
+
+int dev_alloc_name(struct net_device *dev, const char *name)
+{
+	return dev_alloc_name_ns(dev_net(dev), dev, name);
+}
+EXPORT_SYMBOL(dev_alloc_name);
+
+static int dev_get_valid_name(struct net *net, struct net_device *dev,
+			      const char *name)
+{
+	BUG_ON(!net);
+
+	if (!dev_valid_name(name))
+		return -EINVAL;
+
+	if (strchr(name, '%'))
+		return dev_alloc_name_ns(net, dev, name);
+	else if (__dev_get_by_name(net, name))
+		return -EEXIST;
+	else if (dev->name != name)
+		strlcpy(dev->name, name, IFNAMSIZ);
+
+	return 0;
+}
+
+/**
+ *	dev_change_name - change name of a device
+ *	@dev: device
+ *	@newname: name (or format string) must be at least IFNAMSIZ
+ *
+ *	Change name of a device, can pass format strings "eth%d".
+ *	for wildcarding.
+ */
+int dev_change_name(struct net_device *dev, const char *newname)
+{
+	unsigned char old_assign_type;
+	char oldname[IFNAMSIZ];
+	int err = 0;
+	int ret;
+	struct net *net;
+
+	ASSERT_RTNL();
+	BUG_ON(!dev_net(dev));
+
+	net = dev_net(dev);
+
+	/* Some auto-enslaved devices e.g. failover slaves are
+	 * special, as userspace might rename the device after
+	 * the interface had been brought up and running since
+	 * the point kernel initiated auto-enslavement. Allow
+	 * live name change even when these slave devices are
+	 * up and running.
+	 *
+	 * Typically, users of these auto-enslaving devices
+	 * don't actually care about slave name change, as
+	 * they are supposed to operate on master interface
+	 * directly.
+	 */
+	if (dev->flags & IFF_UP &&
+	    likely(!(dev->priv_flags & IFF_LIVE_RENAME_OK)))
+		return -EBUSY;
+
+	down_write(&devnet_rename_sem);
+
+	if (strncmp(newname, dev->name, IFNAMSIZ) == 0) {
+		up_write(&devnet_rename_sem);
+		return 0;
+	}
+
+	memcpy(oldname, dev->name, IFNAMSIZ);
+
+	err = dev_get_valid_name(net, dev, newname);
+	if (err < 0) {
+		up_write(&devnet_rename_sem);
+		return err;
+	}
+
+	if (oldname[0] && !strchr(oldname, '%'))
+		netdev_info(dev, "renamed from %s\n", oldname);
+
+	old_assign_type = dev->name_assign_type;
+	dev->name_assign_type = NET_NAME_RENAMED;
+
+rollback:
+	ret = device_rename(&dev->dev, dev->name);
+	if (ret) {
+		memcpy(dev->name, oldname, IFNAMSIZ);
+		dev->name_assign_type = old_assign_type;
+		up_write(&devnet_rename_sem);
+		return ret;
+	}
+
+	up_write(&devnet_rename_sem);
+
+	netdev_adjacent_rename_links(dev, oldname);
+
+	write_lock_bh(&dev_base_lock);
+	netdev_name_node_del(dev->name_node);
+	write_unlock_bh(&dev_base_lock);
+
+	synchronize_rcu();
+
+	write_lock_bh(&dev_base_lock);
+	netdev_name_node_add(net, dev->name_node);
+	write_unlock_bh(&dev_base_lock);
+
+	ret = call_netdevice_notifiers(NETDEV_CHANGENAME, dev);
+	ret = notifier_to_errno(ret);
+
+	if (ret) {
+		/* err >= 0 after dev_alloc_name() or stores the first errno */
+		if (err >= 0) {
+			err = ret;
+			down_write(&devnet_rename_sem);
+			memcpy(dev->name, oldname, IFNAMSIZ);
+			memcpy(oldname, newname, IFNAMSIZ);
+			dev->name_assign_type = old_assign_type;
+			old_assign_type = NET_NAME_RENAMED;
+			goto rollback;
+		} else {
+			pr_err("%s: name change rollback failed: %d\n",
+			       dev->name, ret);
+		}
+	}
+
+	return err;
+}
+
+/**
+ *	dev_set_alias - change ifalias of a device
+ *	@dev: device
+ *	@alias: name up to IFALIASZ
+ *	@len: limit of bytes to copy from info
+ *
+ *	Set ifalias for a device,
+ */
+int dev_set_alias(struct net_device *dev, const char *alias, size_t len)
+{
+	struct dev_ifalias *new_alias = NULL;
+
+	if (len >= IFALIASZ)
+		return -EINVAL;
+
+	if (len) {
+		new_alias = kmalloc(sizeof(*new_alias) + len + 1, GFP_KERNEL);
+		if (!new_alias)
+			return -ENOMEM;
+
+		memcpy(new_alias->ifalias, alias, len);
+		new_alias->ifalias[len] = 0;
+	}
+
+	mutex_lock(&ifalias_mutex);
+	new_alias = rcu_replace_pointer(dev->ifalias, new_alias,
+					mutex_is_locked(&ifalias_mutex));
+	mutex_unlock(&ifalias_mutex);
+
+	if (new_alias)
+		kfree_rcu(new_alias, rcuhead);
+
+	return len;
+}
+EXPORT_SYMBOL(dev_set_alias);
+
+/**
+ *	dev_get_alias - get ifalias of a device
+ *	@dev: device
+ *	@name: buffer to store name of ifalias
+ *	@len: size of buffer
+ *
+ *	get ifalias for a device.  Caller must make sure dev cannot go
+ *	away,  e.g. rcu read lock or own a reference count to device.
+ */
+int dev_get_alias(const struct net_device *dev, char *name, size_t len)
+{
+	const struct dev_ifalias *alias;
+	int ret = 0;
+
+	rcu_read_lock();
+	alias = rcu_dereference(dev->ifalias);
+	if (alias)
+		ret = snprintf(name, len, "%s", alias->ifalias);
+	rcu_read_unlock();
+
+	return ret;
+}
+
+/**
+ *	netdev_features_change - device changes features
+ *	@dev: device to cause notification
+ *
+ *	Called to indicate a device has changed features.
+ */
+void netdev_features_change(struct net_device *dev)
+{
+	call_netdevice_notifiers(NETDEV_FEAT_CHANGE, dev);
+}
+EXPORT_SYMBOL(netdev_features_change);
+
+/**
+ *	netdev_state_change - device changes state
+ *	@dev: device to cause notification
+ *
+ *	Called to indicate a device has changed state. This function calls
+ *	the notifier chains for netdev_chain and sends a NEWLINK message
+ *	to the routing socket.
+ */
+void netdev_state_change(struct net_device *dev)
+{
+	if (dev->flags & IFF_UP) {
+		struct netdev_notifier_change_info change_info = {
+			.info.dev = dev,
+		};
+
+		call_netdevice_notifiers_info(NETDEV_CHANGE,
+					      &change_info.info);
+		rtmsg_ifinfo(RTM_NEWLINK, dev, 0, GFP_KERNEL);
+	}
+}
+EXPORT_SYMBOL(netdev_state_change);
+
+/**
+ * netdev_notify_peers - notify network peers about existence of @dev
+ * @dev: network device
+ *
+ * Generate traffic such that interested network peers are aware of
+ * @dev, such as by generating a gratuitous ARP. This may be used when
+ * a device wants to inform the rest of the network about some sort of
+ * reconfiguration such as a failover event or virtual machine
+ * migration.
+ */
+void netdev_notify_peers(struct net_device *dev)
+{
+	rtnl_lock();
+	call_netdevice_notifiers(NETDEV_NOTIFY_PEERS, dev);
+	call_netdevice_notifiers(NETDEV_RESEND_IGMP, dev);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(netdev_notify_peers);
+
+static int __dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+	int ret;
+
+	ASSERT_RTNL();
+
+	if (!netif_device_present(dev)) {
+		/* may be detached because parent is runtime-suspended */
+		if (dev->dev.parent)
+			pm_runtime_resume(dev->dev.parent);
+		if (!netif_device_present(dev))
+			return -ENODEV;
+	}
+
+	/* Block netpoll from trying to do any rx path servicing.
+	 * If we don't do this there is a chance ndo_poll_controller
+	 * or ndo_poll may be running while we open the device
+	 */
+	netpoll_poll_disable(dev);
+
+	ret = call_netdevice_notifiers_extack(NETDEV_PRE_UP, dev, extack);
+	ret = notifier_to_errno(ret);
+	if (ret)
+		return ret;
+
+	set_bit(__LINK_STATE_START, &dev->state);
+
+	if (ops->ndo_validate_addr)
+		ret = ops->ndo_validate_addr(dev);
+
+	if (!ret && ops->ndo_open)
+		ret = ops->ndo_open(dev);
+
+	netpoll_poll_enable(dev);
+
+	if (ret)
+		clear_bit(__LINK_STATE_START, &dev->state);
+	else {
+		dev->flags |= IFF_UP;
+		dev_set_rx_mode(dev);
+		dev_activate(dev);
+		add_device_randomness(dev->dev_addr, dev->addr_len);
+	}
+
+	return ret;
+}
+
+/**
+ *	dev_open	- prepare an interface for use.
+ *	@dev: device to open
+ *	@extack: netlink extended ack
+ *
+ *	Takes a device from down to up state. The device's private open
+ *	function is invoked and then the multicast lists are loaded. Finally
+ *	the device is moved into the up state and a %NETDEV_UP message is
+ *	sent to the netdev notifier chain.
+ *
+ *	Calling this function on an active interface is a nop. On a failure
+ *	a negative errno code is returned.
+ */
+int dev_open(struct net_device *dev, struct netlink_ext_ack *extack)
+{
+	int ret;
+
+	if (dev->flags & IFF_UP)
+		return 0;
+
+	ret = __dev_open(dev, extack);
+	if (ret < 0)
+		return ret;
+
+	rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
+	call_netdevice_notifiers(NETDEV_UP, dev);
+
+	return ret;
+}
+EXPORT_SYMBOL(dev_open);
+
+static void __dev_close_many(struct list_head *head)
+{
+	struct net_device *dev;
+
+	ASSERT_RTNL();
+	might_sleep();
+
+	list_for_each_entry(dev, head, close_list) {
+		/* Temporarily disable netpoll until the interface is down */
+		netpoll_poll_disable(dev);
+
+		call_netdevice_notifiers(NETDEV_GOING_DOWN, dev);
+
+		clear_bit(__LINK_STATE_START, &dev->state);
+
+		/* Synchronize to scheduled poll. We cannot touch poll list, it
+		 * can be even on different cpu. So just clear netif_running().
+		 *
+		 * dev->stop() will invoke napi_disable() on all of it's
+		 * napi_struct instances on this device.
+		 */
+		smp_mb__after_atomic(); /* Commit netif_running(). */
+	}
+
+	dev_deactivate_many(head);
+
+	list_for_each_entry(dev, head, close_list) {
+		const struct net_device_ops *ops = dev->netdev_ops;
+
+		/*
+		 *	Call the device specific close. This cannot fail.
+		 *	Only if device is UP
+		 *
+		 *	We allow it to be called even after a DETACH hot-plug
+		 *	event.
+		 */
+		if (ops->ndo_stop)
+			ops->ndo_stop(dev);
+
+		dev->flags &= ~IFF_UP;
+		netpoll_poll_enable(dev);
+	}
+}
+
+static void __dev_close(struct net_device *dev)
+{
+	LIST_HEAD(single);
+
+	list_add(&dev->close_list, &single);
+	__dev_close_many(&single);
+	list_del(&single);
+}
+
+void dev_close_many(struct list_head *head, bool unlink)
+{
+	struct net_device *dev, *tmp;
+
+	/* Remove the devices that don't need to be closed */
+	list_for_each_entry_safe(dev, tmp, head, close_list)
+		if (!(dev->flags & IFF_UP))
+			list_del_init(&dev->close_list);
+
+	__dev_close_many(head);
+
+	list_for_each_entry_safe(dev, tmp, head, close_list) {
+		rtmsg_ifinfo(RTM_NEWLINK, dev, IFF_UP|IFF_RUNNING, GFP_KERNEL);
+		call_netdevice_notifiers(NETDEV_DOWN, dev);
+		if (unlink)
+			list_del_init(&dev->close_list);
+	}
+}
+EXPORT_SYMBOL(dev_close_many);
+
+/**
+ *	dev_close - shutdown an interface.
+ *	@dev: device to shutdown
+ *
+ *	This function moves an active device into down state. A
+ *	%NETDEV_GOING_DOWN is sent to the netdev notifier chain. The device
+ *	is then deactivated and finally a %NETDEV_DOWN is sent to the notifier
+ *	chain.
+ */
+void dev_close(struct net_device *dev)
+{
+	if (dev->flags & IFF_UP) {
+		LIST_HEAD(single);
+
+		list_add(&dev->close_list, &single);
+		dev_close_many(&single, true);
+		list_del(&single);
+	}
+}
+EXPORT_SYMBOL(dev_close);
+
+
+/**
+ *	dev_disable_lro - disable Large Receive Offload on a device
+ *	@dev: device
+ *
+ *	Disable Large Receive Offload (LRO) on a net device.  Must be
+ *	called under RTNL.  This is needed if received packets may be
+ *	forwarded to another interface.
+ */
+void dev_disable_lro(struct net_device *dev)
+{
+	struct net_device *lower_dev;
+	struct list_head *iter;
+
+	dev->wanted_features &= ~NETIF_F_LRO;
+	netdev_update_features(dev);
+
+	if (unlikely(dev->features & NETIF_F_LRO))
+		netdev_WARN(dev, "failed to disable LRO!\n");
+
+	netdev_for_each_lower_dev(dev, lower_dev, iter)
+		dev_disable_lro(lower_dev);
+}
+EXPORT_SYMBOL(dev_disable_lro);
+
+/**
+ *	dev_disable_gro_hw - disable HW Generic Receive Offload on a device
+ *	@dev: device
+ *
+ *	Disable HW Generic Receive Offload (GRO_HW) on a net device.  Must be
+ *	called under RTNL.  This is needed if Generic XDP is installed on
+ *	the device.
+ */
+static void dev_disable_gro_hw(struct net_device *dev)
+{
+	dev->wanted_features &= ~NETIF_F_GRO_HW;
+	netdev_update_features(dev);
+
+	if (unlikely(dev->features & NETIF_F_GRO_HW))
+		netdev_WARN(dev, "failed to disable GRO_HW!\n");
+}
+
+const char *netdev_cmd_to_name(enum netdev_cmd cmd)
+{
+#define N(val) 						\
+	case NETDEV_##val:				\
+		return "NETDEV_" __stringify(val);
+	switch (cmd) {
+	N(UP) N(DOWN) N(REBOOT) N(CHANGE) N(REGISTER) N(UNREGISTER)
+	N(CHANGEMTU) N(CHANGEADDR) N(GOING_DOWN) N(CHANGENAME) N(FEAT_CHANGE)
+	N(BONDING_FAILOVER) N(PRE_UP) N(PRE_TYPE_CHANGE) N(POST_TYPE_CHANGE)
+	N(POST_INIT) N(RELEASE) N(NOTIFY_PEERS) N(JOIN) N(CHANGEUPPER)
+	N(RESEND_IGMP) N(PRECHANGEMTU) N(CHANGEINFODATA) N(BONDING_INFO)
+	N(PRECHANGEUPPER) N(CHANGELOWERSTATE) N(UDP_TUNNEL_PUSH_INFO)
+	N(UDP_TUNNEL_DROP_INFO) N(CHANGE_TX_QUEUE_LEN)
+	N(CVLAN_FILTER_PUSH_INFO) N(CVLAN_FILTER_DROP_INFO)
+	N(SVLAN_FILTER_PUSH_INFO) N(SVLAN_FILTER_DROP_INFO)
+	N(PRE_CHANGEADDR)
+	}
+#undef N
+	return "UNKNOWN_NETDEV_EVENT";
+}
+EXPORT_SYMBOL_GPL(netdev_cmd_to_name);
+
+static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val,
+				   struct net_device *dev)
+{
+	struct netdev_notifier_info info = {
+		.dev = dev,
+	};
+
+	return nb->notifier_call(nb, val, &info);
+}
+
+static int call_netdevice_register_notifiers(struct notifier_block *nb,
+					     struct net_device *dev)
+{
+	int err;
+
+	err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev);
+	err = notifier_to_errno(err);
+	if (err)
+		return err;
+
+	if (!(dev->flags & IFF_UP))
+		return 0;
+
+	call_netdevice_notifier(nb, NETDEV_UP, dev);
+	return 0;
+}
+
+static void call_netdevice_unregister_notifiers(struct notifier_block *nb,
+						struct net_device *dev)
+{
+	if (dev->flags & IFF_UP) {
+		call_netdevice_notifier(nb, NETDEV_GOING_DOWN,
+					dev);
+		call_netdevice_notifier(nb, NETDEV_DOWN, dev);
+	}
+	call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev);
+}
+
+static int call_netdevice_register_net_notifiers(struct notifier_block *nb,
+						 struct net *net)
+{
+	struct net_device *dev;
+	int err;
+
+	for_each_netdev(net, dev) {
+		err = call_netdevice_register_notifiers(nb, dev);
+		if (err)
+			goto rollback;
+	}
+	return 0;
+
+rollback:
+	for_each_netdev_continue_reverse(net, dev)
+		call_netdevice_unregister_notifiers(nb, dev);
+	return err;
+}
+
+static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb,
+						    struct net *net)
+{
+	struct net_device *dev;
+
+	for_each_netdev(net, dev)
+		call_netdevice_unregister_notifiers(nb, dev);
+}
+
+static int dev_boot_phase = 1;
+
+/**
+ * register_netdevice_notifier - register a network notifier block
+ * @nb: notifier
+ *
+ * Register a notifier to be called when network device events occur.
+ * The notifier passed is linked into the kernel structures and must
+ * not be reused until it has been unregistered. A negative errno code
+ * is returned on a failure.
+ *
+ * When registered all registration and up events are replayed
+ * to the new notifier to allow device to have a race free
+ * view of the network device list.
+ */
+
+int register_netdevice_notifier(struct notifier_block *nb)
+{
+	struct net *net;
+	int err;
+
+	/* Close race with setup_net() and cleanup_net() */
+	down_write(&pernet_ops_rwsem);
+	rtnl_lock();
+	err = raw_notifier_chain_register(&netdev_chain, nb);
+	if (err)
+		goto unlock;
+	if (dev_boot_phase)
+		goto unlock;
+	for_each_net(net) {
+		err = call_netdevice_register_net_notifiers(nb, net);
+		if (err)
+			goto rollback;
+	}
+
+unlock:
+	rtnl_unlock();
+	up_write(&pernet_ops_rwsem);
+	return err;
+
+rollback:
+	for_each_net_continue_reverse(net)
+		call_netdevice_unregister_net_notifiers(nb, net);
+
+	raw_notifier_chain_unregister(&netdev_chain, nb);
+	goto unlock;
+}
+EXPORT_SYMBOL(register_netdevice_notifier);
+
+/**
+ * unregister_netdevice_notifier - unregister a network notifier block
+ * @nb: notifier
+ *
+ * Unregister a notifier previously registered by
+ * register_netdevice_notifier(). The notifier is unlinked into the
+ * kernel structures and may then be reused. A negative errno code
+ * is returned on a failure.
+ *
+ * After unregistering unregister and down device events are synthesized
+ * for all devices on the device list to the removed notifier to remove
+ * the need for special case cleanup code.
+ */
+
+int unregister_netdevice_notifier(struct notifier_block *nb)
+{
+	struct net *net;
+	int err;
+
+	/* Close race with setup_net() and cleanup_net() */
+	down_write(&pernet_ops_rwsem);
+	rtnl_lock();
+	err = raw_notifier_chain_unregister(&netdev_chain, nb);
+	if (err)
+		goto unlock;
+
+	for_each_net(net)
+		call_netdevice_unregister_net_notifiers(nb, net);
+
+unlock:
+	rtnl_unlock();
+	up_write(&pernet_ops_rwsem);
+	return err;
+}
+EXPORT_SYMBOL(unregister_netdevice_notifier);
+
+static int __register_netdevice_notifier_net(struct net *net,
+					     struct notifier_block *nb,
+					     bool ignore_call_fail)
+{
+	int err;
+
+	err = raw_notifier_chain_register(&net->netdev_chain, nb);
+	if (err)
+		return err;
+	if (dev_boot_phase)
+		return 0;
+
+	err = call_netdevice_register_net_notifiers(nb, net);
+	if (err && !ignore_call_fail)
+		goto chain_unregister;
+
+	return 0;
+
+chain_unregister:
+	raw_notifier_chain_unregister(&net->netdev_chain, nb);
+	return err;
+}
+
+static int __unregister_netdevice_notifier_net(struct net *net,
+					       struct notifier_block *nb)
+{
+	int err;
+
+	err = raw_notifier_chain_unregister(&net->netdev_chain, nb);
+	if (err)
+		return err;
+
+	call_netdevice_unregister_net_notifiers(nb, net);
+	return 0;
+}
+
+/**
+ * register_netdevice_notifier_net - register a per-netns network notifier block
+ * @net: network namespace
+ * @nb: notifier
+ *
+ * Register a notifier to be called when network device events occur.
+ * The notifier passed is linked into the kernel structures and must
+ * not be reused until it has been unregistered. A negative errno code
+ * is returned on a failure.
+ *
+ * When registered all registration and up events are replayed
+ * to the new notifier to allow device to have a race free
+ * view of the network device list.
+ */
+
+int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb)
+{
+	int err;
+
+	rtnl_lock();
+	err = __register_netdevice_notifier_net(net, nb, false);
+	rtnl_unlock();
+	return err;
+}
+EXPORT_SYMBOL(register_netdevice_notifier_net);
+
+/**
+ * unregister_netdevice_notifier_net - unregister a per-netns
+ *                                     network notifier block
+ * @net: network namespace
+ * @nb: notifier
+ *
+ * Unregister a notifier previously registered by
+ * register_netdevice_notifier(). The notifier is unlinked into the
+ * kernel structures and may then be reused. A negative errno code
+ * is returned on a failure.
+ *
+ * After unregistering unregister and down device events are synthesized
+ * for all devices on the device list to the removed notifier to remove
+ * the need for special case cleanup code.
+ */
+
+int unregister_netdevice_notifier_net(struct net *net,
+				      struct notifier_block *nb)
+{
+	int err;
+
+	rtnl_lock();
+	err = __unregister_netdevice_notifier_net(net, nb);
+	rtnl_unlock();
+	return err;
+}
+EXPORT_SYMBOL(unregister_netdevice_notifier_net);
+
+int register_netdevice_notifier_dev_net(struct net_device *dev,
+					struct notifier_block *nb,
+					struct netdev_net_notifier *nn)
+{
+	int err;
+
+	rtnl_lock();
+	err = __register_netdevice_notifier_net(dev_net(dev), nb, false);
+	if (!err) {
+		nn->nb = nb;
+		list_add(&nn->list, &dev->net_notifier_list);
+	}
+	rtnl_unlock();
+	return err;
+}
+EXPORT_SYMBOL(register_netdevice_notifier_dev_net);
+
+int unregister_netdevice_notifier_dev_net(struct net_device *dev,
+					  struct notifier_block *nb,
+					  struct netdev_net_notifier *nn)
+{
+	int err;
+
+	rtnl_lock();
+	list_del(&nn->list);
+	err = __unregister_netdevice_notifier_net(dev_net(dev), nb);
+	rtnl_unlock();
+	return err;
+}
+EXPORT_SYMBOL(unregister_netdevice_notifier_dev_net);
+
+static void move_netdevice_notifiers_dev_net(struct net_device *dev,
+					     struct net *net)
+{
+	struct netdev_net_notifier *nn;
+
+	list_for_each_entry(nn, &dev->net_notifier_list, list) {
+		__unregister_netdevice_notifier_net(dev_net(dev), nn->nb);
+		__register_netdevice_notifier_net(net, nn->nb, true);
+	}
+}
+
+/**
+ *	call_netdevice_notifiers_info - call all network notifier blocks
+ *	@val: value passed unmodified to notifier function
+ *	@info: notifier information data
+ *
+ *	Call all network notifier blocks.  Parameters and return value
+ *	are as for raw_notifier_call_chain().
+ */
+
+static int call_netdevice_notifiers_info(unsigned long val,
+					 struct netdev_notifier_info *info)
+{
+	struct net *net = dev_net(info->dev);
+	int ret;
+
+	ASSERT_RTNL();
+
+	/* Run per-netns notifier block chain first, then run the global one.
+	 * Hopefully, one day, the global one is going to be removed after
+	 * all notifier block registrators get converted to be per-netns.
+	 */
+	ret = raw_notifier_call_chain(&net->netdev_chain, val, info);
+	if (ret & NOTIFY_STOP_MASK)
+		return ret;
+	return raw_notifier_call_chain(&netdev_chain, val, info);
+}
+
+static int call_netdevice_notifiers_extack(unsigned long val,
+					   struct net_device *dev,
+					   struct netlink_ext_ack *extack)
+{
+	struct netdev_notifier_info info = {
+		.dev = dev,
+		.extack = extack,
+	};
+
+	return call_netdevice_notifiers_info(val, &info);
+}
+
+/**
+ *	call_netdevice_notifiers - call all network notifier blocks
+ *      @val: value passed unmodified to notifier function
+ *      @dev: net_device pointer passed unmodified to notifier function
+ *
+ *	Call all network notifier blocks.  Parameters and return value
+ *	are as for raw_notifier_call_chain().
+ */
+
+int call_netdevice_notifiers(unsigned long val, struct net_device *dev)
+{
+	return call_netdevice_notifiers_extack(val, dev, NULL);
+}
+EXPORT_SYMBOL(call_netdevice_notifiers);
+
+/**
+ *	call_netdevice_notifiers_mtu - call all network notifier blocks
+ *	@val: value passed unmodified to notifier function
+ *	@dev: net_device pointer passed unmodified to notifier function
+ *	@arg: additional u32 argument passed to the notifier function
+ *
+ *	Call all network notifier blocks.  Parameters and return value
+ *	are as for raw_notifier_call_chain().
+ */
+static int call_netdevice_notifiers_mtu(unsigned long val,
+					struct net_device *dev, u32 arg)
+{
+	struct netdev_notifier_info_ext info = {
+		.info.dev = dev,
+		.ext.mtu = arg,
+	};
+
+	BUILD_BUG_ON(offsetof(struct netdev_notifier_info_ext, info) != 0);
+
+	return call_netdevice_notifiers_info(val, &info.info);
+}
+
+#ifdef CONFIG_NET_INGRESS
+static DEFINE_STATIC_KEY_FALSE(ingress_needed_key);
+
+void net_inc_ingress_queue(void)
+{
+	static_branch_inc(&ingress_needed_key);
+}
+EXPORT_SYMBOL_GPL(net_inc_ingress_queue);
+
+void net_dec_ingress_queue(void)
+{
+	static_branch_dec(&ingress_needed_key);
+}
+EXPORT_SYMBOL_GPL(net_dec_ingress_queue);
+#endif
+
+#ifdef CONFIG_NET_EGRESS
+static DEFINE_STATIC_KEY_FALSE(egress_needed_key);
+
+void net_inc_egress_queue(void)
+{
+	static_branch_inc(&egress_needed_key);
+}
+EXPORT_SYMBOL_GPL(net_inc_egress_queue);
+
+void net_dec_egress_queue(void)
+{
+	static_branch_dec(&egress_needed_key);
+}
+EXPORT_SYMBOL_GPL(net_dec_egress_queue);
+#endif
+
+static DEFINE_STATIC_KEY_FALSE(netstamp_needed_key);
+#ifdef CONFIG_JUMP_LABEL
+static atomic_t netstamp_needed_deferred;
+static atomic_t netstamp_wanted;
+static void netstamp_clear(struct work_struct *work)
+{
+	int deferred = atomic_xchg(&netstamp_needed_deferred, 0);
+	int wanted;
+
+	wanted = atomic_add_return(deferred, &netstamp_wanted);
+	if (wanted > 0)
+		static_branch_enable(&netstamp_needed_key);
+	else
+		static_branch_disable(&netstamp_needed_key);
+}
+static DECLARE_WORK(netstamp_work, netstamp_clear);
+#endif
+
+void net_enable_timestamp(void)
+{
+#ifdef CONFIG_JUMP_LABEL
+	int wanted;
+
+	while (1) {
+		wanted = atomic_read(&netstamp_wanted);
+		if (wanted <= 0)
+			break;
+		if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted + 1) == wanted)
+			return;
+	}
+	atomic_inc(&netstamp_needed_deferred);
+	schedule_work(&netstamp_work);
+#else
+	static_branch_inc(&netstamp_needed_key);
+#endif
+}
+EXPORT_SYMBOL(net_enable_timestamp);
+
+void net_disable_timestamp(void)
+{
+#ifdef CONFIG_JUMP_LABEL
+	int wanted;
+
+	while (1) {
+		wanted = atomic_read(&netstamp_wanted);
+		if (wanted <= 1)
+			break;
+		if (atomic_cmpxchg(&netstamp_wanted, wanted, wanted - 1) == wanted)
+			return;
+	}
+	atomic_dec(&netstamp_needed_deferred);
+	schedule_work(&netstamp_work);
+#else
+	static_branch_dec(&netstamp_needed_key);
+#endif
+}
+EXPORT_SYMBOL(net_disable_timestamp);
+
+static inline void net_timestamp_set(struct sk_buff *skb)
+{
+	skb->tstamp = 0;
+	if (static_branch_unlikely(&netstamp_needed_key))
+		__net_timestamp(skb);
+}
+
+#define net_timestamp_check(COND, SKB)				\
+	if (static_branch_unlikely(&netstamp_needed_key)) {	\
+		if ((COND) && !(SKB)->tstamp)			\
+			__net_timestamp(SKB);			\
+	}							\
+
+bool is_skb_forwardable(const struct net_device *dev, const struct sk_buff *skb)
+{
+	unsigned int len;
+
+	if (!(dev->flags & IFF_UP))
+		return false;
+
+	len = dev->mtu + dev->hard_header_len + VLAN_HLEN;
+	if (skb->len <= len)
+		return true;
+
+	/* if TSO is enabled, we don't care about the length as the packet
+	 * could be forwarded without being segmented before
+	 */
+	if (skb_is_gso(skb))
+		return true;
+
+	return false;
+}
+EXPORT_SYMBOL_GPL(is_skb_forwardable);
+
+int __dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
+{
+	int ret = ____dev_forward_skb(dev, skb);
+
+	if (likely(!ret)) {
+		skb->protocol = eth_type_trans(skb, dev);
+		skb_postpull_rcsum(skb, eth_hdr(skb), ETH_HLEN);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(__dev_forward_skb);
+
+/**
+ * dev_forward_skb - loopback an skb to another netif
+ *
+ * @dev: destination network device
+ * @skb: buffer to forward
+ *
+ * return values:
+ *	NET_RX_SUCCESS	(no congestion)
+ *	NET_RX_DROP     (packet was dropped, but freed)
+ *
+ * dev_forward_skb can be used for injecting an skb from the
+ * start_xmit function of one device into the receive queue
+ * of another device.
+ *
+ * The receiving device may be in another namespace, so
+ * we have to clear all information in the skb that could
+ * impact namespace isolation.
+ */
+int dev_forward_skb(struct net_device *dev, struct sk_buff *skb)
+{
+	return __dev_forward_skb(dev, skb) ?: netif_rx_internal(skb);
+}
+EXPORT_SYMBOL_GPL(dev_forward_skb);
+
+static inline int deliver_skb(struct sk_buff *skb,
+			      struct packet_type *pt_prev,
+			      struct net_device *orig_dev)
+{
+	if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
+		return -ENOMEM;
+	refcount_inc(&skb->users);
+	return pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+}
+
+static inline void deliver_ptype_list_skb(struct sk_buff *skb,
+					  struct packet_type **pt,
+					  struct net_device *orig_dev,
+					  __be16 type,
+					  struct list_head *ptype_list)
+{
+	struct packet_type *ptype, *pt_prev = *pt;
+
+	list_for_each_entry_rcu(ptype, ptype_list, list) {
+		if (ptype->type != type)
+			continue;
+		if (pt_prev)
+			deliver_skb(skb, pt_prev, orig_dev);
+		pt_prev = ptype;
+	}
+	*pt = pt_prev;
+}
+
+static inline bool skb_loop_sk(struct packet_type *ptype, struct sk_buff *skb)
+{
+	if (!ptype->af_packet_priv || !skb->sk)
+		return false;
+
+	if (ptype->id_match)
+		return ptype->id_match(ptype, skb->sk);
+	else if ((struct sock *)ptype->af_packet_priv == skb->sk)
+		return true;
+
+	return false;
+}
+
+/**
+ * dev_nit_active - return true if any network interface taps are in use
+ *
+ * @dev: network device to check for the presence of taps
+ */
+bool dev_nit_active(struct net_device *dev)
+{
+	return !list_empty(&ptype_all) || !list_empty(&dev->ptype_all);
+}
+EXPORT_SYMBOL_GPL(dev_nit_active);
+
+/*
+ *	Support routine. Sends outgoing frames to any network
+ *	taps currently in use.
+ */
+
+void dev_queue_xmit_nit(struct sk_buff *skb, struct net_device *dev)
+{
+	struct packet_type *ptype;
+	struct sk_buff *skb2 = NULL;
+	struct packet_type *pt_prev = NULL;
+	struct list_head *ptype_list = &ptype_all;
+
+	rcu_read_lock();
+again:
+	list_for_each_entry_rcu(ptype, ptype_list, list) {
+		if (ptype->ignore_outgoing)
+			continue;
+
+		/* Never send packets back to the socket
+		 * they originated from - MvS (miquels@drinkel.ow.org)
+		 */
+		if (skb_loop_sk(ptype, skb))
+			continue;
+
+		if (pt_prev) {
+			deliver_skb(skb2, pt_prev, skb->dev);
+			pt_prev = ptype;
+			continue;
+		}
+
+		/* need to clone skb, done only once */
+		skb2 = skb_clone(skb, GFP_ATOMIC);
+		if (!skb2)
+			goto out_unlock;
+
+		net_timestamp_set(skb2);
+
+		/* skb->nh should be correctly
+		 * set by sender, so that the second statement is
+		 * just protection against buggy protocols.
+		 */
+		skb_reset_mac_header(skb2);
+
+		if (skb_network_header(skb2) < skb2->data ||
+		    skb_network_header(skb2) > skb_tail_pointer(skb2)) {
+			net_crit_ratelimited("protocol %04x is buggy, dev %s\n",
+					     ntohs(skb2->protocol),
+					     dev->name);
+			skb_reset_network_header(skb2);
+		}
+
+		skb2->transport_header = skb2->network_header;
+		skb2->pkt_type = PACKET_OUTGOING;
+		pt_prev = ptype;
+	}
+
+	if (ptype_list == &ptype_all) {
+		ptype_list = &dev->ptype_all;
+		goto again;
+	}
+out_unlock:
+	if (pt_prev) {
+		if (!skb_orphan_frags_rx(skb2, GFP_ATOMIC))
+			pt_prev->func(skb2, skb->dev, pt_prev, skb->dev);
+		else
+			kfree_skb(skb2);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL_GPL(dev_queue_xmit_nit);
+
+/**
+ * netif_setup_tc - Handle tc mappings on real_num_tx_queues change
+ * @dev: Network device
+ * @txq: number of queues available
+ *
+ * If real_num_tx_queues is changed the tc mappings may no longer be
+ * valid. To resolve this verify the tc mapping remains valid and if
+ * not NULL the mapping. With no priorities mapping to this
+ * offset/count pair it will no longer be used. In the worst case TC0
+ * is invalid nothing can be done so disable priority mappings. If is
+ * expected that drivers will fix this mapping if they can before
+ * calling netif_set_real_num_tx_queues.
+ */
+static void netif_setup_tc(struct net_device *dev, unsigned int txq)
+{
+	int i;
+	struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
+
+	/* If TC0 is invalidated disable TC mapping */
+	if (tc->offset + tc->count > txq) {
+		pr_warn("Number of in use tx queues changed invalidating tc mappings. Priority traffic classification disabled!\n");
+		dev->num_tc = 0;
+		return;
+	}
+
+	/* Invalidated prio to tc mappings set to TC0 */
+	for (i = 1; i < TC_BITMASK + 1; i++) {
+		int q = netdev_get_prio_tc_map(dev, i);
+
+		tc = &dev->tc_to_txq[q];
+		if (tc->offset + tc->count > txq) {
+			pr_warn("Number of in use tx queues changed. Priority %i to tc mapping %i is no longer valid. Setting map to 0\n",
+				i, q);
+			netdev_set_prio_tc_map(dev, i, 0);
+		}
+	}
+}
+
+int netdev_txq_to_tc(struct net_device *dev, unsigned int txq)
+{
+	if (dev->num_tc) {
+		struct netdev_tc_txq *tc = &dev->tc_to_txq[0];
+		int i;
+
+		/* walk through the TCs and see if it falls into any of them */
+		for (i = 0; i < TC_MAX_QUEUE; i++, tc++) {
+			if ((txq - tc->offset) < tc->count)
+				return i;
+		}
+
+		/* didn't find it, just return -1 to indicate no match */
+		return -1;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(netdev_txq_to_tc);
+
+#ifdef CONFIG_XPS
+struct static_key xps_needed __read_mostly;
+EXPORT_SYMBOL(xps_needed);
+struct static_key xps_rxqs_needed __read_mostly;
+EXPORT_SYMBOL(xps_rxqs_needed);
+static DEFINE_MUTEX(xps_map_mutex);
+#define xmap_dereference(P)		\
+	rcu_dereference_protected((P), lockdep_is_held(&xps_map_mutex))
+
+static bool remove_xps_queue(struct xps_dev_maps *dev_maps,
+			     int tci, u16 index)
+{
+	struct xps_map *map = NULL;
+	int pos;
+
+	if (dev_maps)
+		map = xmap_dereference(dev_maps->attr_map[tci]);
+	if (!map)
+		return false;
+
+	for (pos = map->len; pos--;) {
+		if (map->queues[pos] != index)
+			continue;
+
+		if (map->len > 1) {
+			map->queues[pos] = map->queues[--map->len];
+			break;
+		}
+
+		RCU_INIT_POINTER(dev_maps->attr_map[tci], NULL);
+		kfree_rcu(map, rcu);
+		return false;
+	}
+
+	return true;
+}
+
+static bool remove_xps_queue_cpu(struct net_device *dev,
+				 struct xps_dev_maps *dev_maps,
+				 int cpu, u16 offset, u16 count)
+{
+	int num_tc = dev->num_tc ? : 1;
+	bool active = false;
+	int tci;
+
+	for (tci = cpu * num_tc; num_tc--; tci++) {
+		int i, j;
+
+		for (i = count, j = offset; i--; j++) {
+			if (!remove_xps_queue(dev_maps, tci, j))
+				break;
+		}
+
+		active |= i < 0;
+	}
+
+	return active;
+}
+
+static void reset_xps_maps(struct net_device *dev,
+			   struct xps_dev_maps *dev_maps,
+			   bool is_rxqs_map)
+{
+	if (is_rxqs_map) {
+		static_key_slow_dec_cpuslocked(&xps_rxqs_needed);
+		RCU_INIT_POINTER(dev->xps_rxqs_map, NULL);
+	} else {
+		RCU_INIT_POINTER(dev->xps_cpus_map, NULL);
+	}
+	static_key_slow_dec_cpuslocked(&xps_needed);
+	kfree_rcu(dev_maps, rcu);
+}
+
+static void clean_xps_maps(struct net_device *dev, const unsigned long *mask,
+			   struct xps_dev_maps *dev_maps, unsigned int nr_ids,
+			   u16 offset, u16 count, bool is_rxqs_map)
+{
+	bool active = false;
+	int i, j;
+
+	for (j = -1; j = netif_attrmask_next(j, mask, nr_ids),
+	     j < nr_ids;)
+		active |= remove_xps_queue_cpu(dev, dev_maps, j, offset,
+					       count);
+	if (!active)
+		reset_xps_maps(dev, dev_maps, is_rxqs_map);
+
+	if (!is_rxqs_map) {
+		for (i = offset + (count - 1); count--; i--) {
+			netdev_queue_numa_node_write(
+				netdev_get_tx_queue(dev, i),
+				NUMA_NO_NODE);
+		}
+	}
+}
+
+static void netif_reset_xps_queues(struct net_device *dev, u16 offset,
+				   u16 count)
+{
+	const unsigned long *possible_mask = NULL;
+	struct xps_dev_maps *dev_maps;
+	unsigned int nr_ids;
+
+	if (!static_key_false(&xps_needed))
+		return;
+
+	cpus_read_lock();
+	mutex_lock(&xps_map_mutex);
+
+	if (static_key_false(&xps_rxqs_needed)) {
+		dev_maps = xmap_dereference(dev->xps_rxqs_map);
+		if (dev_maps) {
+			nr_ids = dev->num_rx_queues;
+			clean_xps_maps(dev, possible_mask, dev_maps, nr_ids,
+				       offset, count, true);
+		}
+	}
+
+	dev_maps = xmap_dereference(dev->xps_cpus_map);
+	if (!dev_maps)
+		goto out_no_maps;
+
+	if (num_possible_cpus() > 1)
+		possible_mask = cpumask_bits(cpu_possible_mask);
+	nr_ids = nr_cpu_ids;
+	clean_xps_maps(dev, possible_mask, dev_maps, nr_ids, offset, count,
+		       false);
+
+out_no_maps:
+	mutex_unlock(&xps_map_mutex);
+	cpus_read_unlock();
+}
+
+static void netif_reset_xps_queues_gt(struct net_device *dev, u16 index)
+{
+	netif_reset_xps_queues(dev, index, dev->num_tx_queues - index);
+}
+
+static struct xps_map *expand_xps_map(struct xps_map *map, int attr_index,
+				      u16 index, bool is_rxqs_map)
+{
+	struct xps_map *new_map;
+	int alloc_len = XPS_MIN_MAP_ALLOC;
+	int i, pos;
+
+	for (pos = 0; map && pos < map->len; pos++) {
+		if (map->queues[pos] != index)
+			continue;
+		return map;
+	}
+
+	/* Need to add tx-queue to this CPU's/rx-queue's existing map */
+	if (map) {
+		if (pos < map->alloc_len)
+			return map;
+
+		alloc_len = map->alloc_len * 2;
+	}
+
+	/* Need to allocate new map to store tx-queue on this CPU's/rx-queue's
+	 *  map
+	 */
+	if (is_rxqs_map)
+		new_map = kzalloc(XPS_MAP_SIZE(alloc_len), GFP_KERNEL);
+	else
+		new_map = kzalloc_node(XPS_MAP_SIZE(alloc_len), GFP_KERNEL,
+				       cpu_to_node(attr_index));
+	if (!new_map)
+		return NULL;
+
+	for (i = 0; i < pos; i++)
+		new_map->queues[i] = map->queues[i];
+	new_map->alloc_len = alloc_len;
+	new_map->len = pos;
+
+	return new_map;
+}
+
+/* Must be called under cpus_read_lock */
+int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
+			  u16 index, bool is_rxqs_map)
+{
+	const unsigned long *online_mask = NULL, *possible_mask = NULL;
+	struct xps_dev_maps *dev_maps, *new_dev_maps = NULL;
+	int i, j, tci, numa_node_id = -2;
+	int maps_sz, num_tc = 1, tc = 0;
+	struct xps_map *map, *new_map;
+	bool active = false;
+	unsigned int nr_ids;
+
+	WARN_ON_ONCE(index >= dev->num_tx_queues);
+
+	if (dev->num_tc) {
+		/* Do not allow XPS on subordinate device directly */
+		num_tc = dev->num_tc;
+		if (num_tc < 0)
+			return -EINVAL;
+
+		/* If queue belongs to subordinate dev use its map */
+		dev = netdev_get_tx_queue(dev, index)->sb_dev ? : dev;
+
+		tc = netdev_txq_to_tc(dev, index);
+		if (tc < 0)
+			return -EINVAL;
+	}
+
+	mutex_lock(&xps_map_mutex);
+	if (is_rxqs_map) {
+		maps_sz = XPS_RXQ_DEV_MAPS_SIZE(num_tc, dev->num_rx_queues);
+		dev_maps = xmap_dereference(dev->xps_rxqs_map);
+		nr_ids = dev->num_rx_queues;
+	} else {
+		maps_sz = XPS_CPU_DEV_MAPS_SIZE(num_tc);
+		if (num_possible_cpus() > 1) {
+			online_mask = cpumask_bits(cpu_online_mask);
+			possible_mask = cpumask_bits(cpu_possible_mask);
+		}
+		dev_maps = xmap_dereference(dev->xps_cpus_map);
+		nr_ids = nr_cpu_ids;
+	}
+
+	if (maps_sz < L1_CACHE_BYTES)
+		maps_sz = L1_CACHE_BYTES;
+
+	/* allocate memory for queue storage */
+	for (j = -1; j = netif_attrmask_next_and(j, online_mask, mask, nr_ids),
+	     j < nr_ids;) {
+		if (!new_dev_maps)
+			new_dev_maps = kzalloc(maps_sz, GFP_KERNEL);
+		if (!new_dev_maps) {
+			mutex_unlock(&xps_map_mutex);
+			return -ENOMEM;
+		}
+
+		tci = j * num_tc + tc;
+		map = dev_maps ? xmap_dereference(dev_maps->attr_map[tci]) :
+				 NULL;
+
+		map = expand_xps_map(map, j, index, is_rxqs_map);
+		if (!map)
+			goto error;
+
+		RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
+	}
+
+	if (!new_dev_maps)
+		goto out_no_new_maps;
+
+	if (!dev_maps) {
+		/* Increment static keys at most once per type */
+		static_key_slow_inc_cpuslocked(&xps_needed);
+		if (is_rxqs_map)
+			static_key_slow_inc_cpuslocked(&xps_rxqs_needed);
+	}
+
+	for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids),
+	     j < nr_ids;) {
+		/* copy maps belonging to foreign traffic classes */
+		for (i = tc, tci = j * num_tc; dev_maps && i--; tci++) {
+			/* fill in the new device map from the old device map */
+			map = xmap_dereference(dev_maps->attr_map[tci]);
+			RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
+		}
+
+		/* We need to explicitly update tci as prevous loop
+		 * could break out early if dev_maps is NULL.
+		 */
+		tci = j * num_tc + tc;
+
+		if (netif_attr_test_mask(j, mask, nr_ids) &&
+		    netif_attr_test_online(j, online_mask, nr_ids)) {
+			/* add tx-queue to CPU/rx-queue maps */
+			int pos = 0;
+
+			map = xmap_dereference(new_dev_maps->attr_map[tci]);
+			while ((pos < map->len) && (map->queues[pos] != index))
+				pos++;
+
+			if (pos == map->len)
+				map->queues[map->len++] = index;
+#ifdef CONFIG_NUMA
+			if (!is_rxqs_map) {
+				if (numa_node_id == -2)
+					numa_node_id = cpu_to_node(j);
+				else if (numa_node_id != cpu_to_node(j))
+					numa_node_id = -1;
+			}
+#endif
+		} else if (dev_maps) {
+			/* fill in the new device map from the old device map */
+			map = xmap_dereference(dev_maps->attr_map[tci]);
+			RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
+		}
+
+		/* copy maps belonging to foreign traffic classes */
+		for (i = num_tc - tc, tci++; dev_maps && --i; tci++) {
+			/* fill in the new device map from the old device map */
+			map = xmap_dereference(dev_maps->attr_map[tci]);
+			RCU_INIT_POINTER(new_dev_maps->attr_map[tci], map);
+		}
+	}
+
+	if (is_rxqs_map)
+		rcu_assign_pointer(dev->xps_rxqs_map, new_dev_maps);
+	else
+		rcu_assign_pointer(dev->xps_cpus_map, new_dev_maps);
+
+	/* Cleanup old maps */
+	if (!dev_maps)
+		goto out_no_old_maps;
+
+	for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids),
+	     j < nr_ids;) {
+		for (i = num_tc, tci = j * num_tc; i--; tci++) {
+			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
+			map = xmap_dereference(dev_maps->attr_map[tci]);
+			if (map && map != new_map)
+				kfree_rcu(map, rcu);
+		}
+	}
+
+	kfree_rcu(dev_maps, rcu);
+
+out_no_old_maps:
+	dev_maps = new_dev_maps;
+	active = true;
+
+out_no_new_maps:
+	if (!is_rxqs_map) {
+		/* update Tx queue numa node */
+		netdev_queue_numa_node_write(netdev_get_tx_queue(dev, index),
+					     (numa_node_id >= 0) ?
+					     numa_node_id : NUMA_NO_NODE);
+	}
+
+	if (!dev_maps)
+		goto out_no_maps;
+
+	/* removes tx-queue from unused CPUs/rx-queues */
+	for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids),
+	     j < nr_ids;) {
+		for (i = tc, tci = j * num_tc; i--; tci++)
+			active |= remove_xps_queue(dev_maps, tci, index);
+		if (!netif_attr_test_mask(j, mask, nr_ids) ||
+		    !netif_attr_test_online(j, online_mask, nr_ids))
+			active |= remove_xps_queue(dev_maps, tci, index);
+		for (i = num_tc - tc, tci++; --i; tci++)
+			active |= remove_xps_queue(dev_maps, tci, index);
+	}
+
+	/* free map if not active */
+	if (!active)
+		reset_xps_maps(dev, dev_maps, is_rxqs_map);
+
+out_no_maps:
+	mutex_unlock(&xps_map_mutex);
+
+	return 0;
+error:
+	/* remove any maps that we added */
+	for (j = -1; j = netif_attrmask_next(j, possible_mask, nr_ids),
+	     j < nr_ids;) {
+		for (i = num_tc, tci = j * num_tc; i--; tci++) {
+			new_map = xmap_dereference(new_dev_maps->attr_map[tci]);
+			map = dev_maps ?
+			      xmap_dereference(dev_maps->attr_map[tci]) :
+			      NULL;
+			if (new_map && new_map != map)
+				kfree(new_map);
+		}
+	}
+
+	mutex_unlock(&xps_map_mutex);
+
+	kfree(new_dev_maps);
+	return -ENOMEM;
+}
+EXPORT_SYMBOL_GPL(__netif_set_xps_queue);
+
+int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
+			u16 index)
+{
+	int ret;
+
+	cpus_read_lock();
+	ret =  __netif_set_xps_queue(dev, cpumask_bits(mask), index, false);
+	cpus_read_unlock();
+
+	return ret;
+}
+EXPORT_SYMBOL(netif_set_xps_queue);
+
+#endif
+static void netdev_unbind_all_sb_channels(struct net_device *dev)
+{
+	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
+
+	/* Unbind any subordinate channels */
+	while (txq-- != &dev->_tx[0]) {
+		if (txq->sb_dev)
+			netdev_unbind_sb_channel(dev, txq->sb_dev);
+	}
+}
+
+void netdev_reset_tc(struct net_device *dev)
+{
+#ifdef CONFIG_XPS
+	netif_reset_xps_queues_gt(dev, 0);
+#endif
+	netdev_unbind_all_sb_channels(dev);
+
+	/* Reset TC configuration of device */
+	dev->num_tc = 0;
+	memset(dev->tc_to_txq, 0, sizeof(dev->tc_to_txq));
+	memset(dev->prio_tc_map, 0, sizeof(dev->prio_tc_map));
+}
+EXPORT_SYMBOL(netdev_reset_tc);
+
+int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset)
+{
+	if (tc >= dev->num_tc)
+		return -EINVAL;
+
+#ifdef CONFIG_XPS
+	netif_reset_xps_queues(dev, offset, count);
+#endif
+	dev->tc_to_txq[tc].count = count;
+	dev->tc_to_txq[tc].offset = offset;
+	return 0;
+}
+EXPORT_SYMBOL(netdev_set_tc_queue);
+
+int netdev_set_num_tc(struct net_device *dev, u8 num_tc)
+{
+	if (num_tc > TC_MAX_QUEUE)
+		return -EINVAL;
+
+#ifdef CONFIG_XPS
+	netif_reset_xps_queues_gt(dev, 0);
+#endif
+	netdev_unbind_all_sb_channels(dev);
+
+	dev->num_tc = num_tc;
+	return 0;
+}
+EXPORT_SYMBOL(netdev_set_num_tc);
+
+void netdev_unbind_sb_channel(struct net_device *dev,
+			      struct net_device *sb_dev)
+{
+	struct netdev_queue *txq = &dev->_tx[dev->num_tx_queues];
+
+#ifdef CONFIG_XPS
+	netif_reset_xps_queues_gt(sb_dev, 0);
+#endif
+	memset(sb_dev->tc_to_txq, 0, sizeof(sb_dev->tc_to_txq));
+	memset(sb_dev->prio_tc_map, 0, sizeof(sb_dev->prio_tc_map));
+
+	while (txq-- != &dev->_tx[0]) {
+		if (txq->sb_dev == sb_dev)
+			txq->sb_dev = NULL;
+	}
+}
+EXPORT_SYMBOL(netdev_unbind_sb_channel);
+
+int netdev_bind_sb_channel_queue(struct net_device *dev,
+				 struct net_device *sb_dev,
+				 u8 tc, u16 count, u16 offset)
+{
+	/* Make certain the sb_dev and dev are already configured */
+	if (sb_dev->num_tc >= 0 || tc >= dev->num_tc)
+		return -EINVAL;
+
+	/* We cannot hand out queues we don't have */
+	if ((offset + count) > dev->real_num_tx_queues)
+		return -EINVAL;
+
+	/* Record the mapping */
+	sb_dev->tc_to_txq[tc].count = count;
+	sb_dev->tc_to_txq[tc].offset = offset;
+
+	/* Provide a way for Tx queue to find the tc_to_txq map or
+	 * XPS map for itself.
+	 */
+	while (count--)
+		netdev_get_tx_queue(dev, count + offset)->sb_dev = sb_dev;
+
+	return 0;
+}
+EXPORT_SYMBOL(netdev_bind_sb_channel_queue);
+
+int netdev_set_sb_channel(struct net_device *dev, u16 channel)
+{
+	/* Do not use a multiqueue device to represent a subordinate channel */
+	if (netif_is_multiqueue(dev))
+		return -ENODEV;
+
+	/* We allow channels 1 - 32767 to be used for subordinate channels.
+	 * Channel 0 is meant to be "native" mode and used only to represent
+	 * the main root device. We allow writing 0 to reset the device back
+	 * to normal mode after being used as a subordinate channel.
+	 */
+	if (channel > S16_MAX)
+		return -EINVAL;
+
+	dev->num_tc = -channel;
+
+	return 0;
+}
+EXPORT_SYMBOL(netdev_set_sb_channel);
+
+/*
+ * Routine to help set real_num_tx_queues. To avoid skbs mapped to queues
+ * greater than real_num_tx_queues stale skbs on the qdisc must be flushed.
+ */
+int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq)
+{
+	bool disabling;
+	int rc;
+
+	disabling = txq < dev->real_num_tx_queues;
+
+	if (txq < 1 || txq > dev->num_tx_queues)
+		return -EINVAL;
+
+	if (dev->reg_state == NETREG_REGISTERED ||
+	    dev->reg_state == NETREG_UNREGISTERING) {
+		ASSERT_RTNL();
+
+		rc = netdev_queue_update_kobjects(dev, dev->real_num_tx_queues,
+						  txq);
+		if (rc)
+			return rc;
+
+		if (dev->num_tc)
+			netif_setup_tc(dev, txq);
+
+		dev_qdisc_change_real_num_tx(dev, txq);
+
+		dev->real_num_tx_queues = txq;
+
+		if (disabling) {
+			synchronize_net();
+			qdisc_reset_all_tx_gt(dev, txq);
+#ifdef CONFIG_XPS
+			netif_reset_xps_queues_gt(dev, txq);
+#endif
+		}
+	} else {
+		dev->real_num_tx_queues = txq;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(netif_set_real_num_tx_queues);
+
+#ifdef CONFIG_SYSFS
+/**
+ *	netif_set_real_num_rx_queues - set actual number of RX queues used
+ *	@dev: Network device
+ *	@rxq: Actual number of RX queues
+ *
+ *	This must be called either with the rtnl_lock held or before
+ *	registration of the net device.  Returns 0 on success, or a
+ *	negative error code.  If called before registration, it always
+ *	succeeds.
+ */
+int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq)
+{
+	int rc;
+
+	if (rxq < 1 || rxq > dev->num_rx_queues)
+		return -EINVAL;
+
+	if (dev->reg_state == NETREG_REGISTERED) {
+		ASSERT_RTNL();
+
+		rc = net_rx_queue_update_kobjects(dev, dev->real_num_rx_queues,
+						  rxq);
+		if (rc)
+			return rc;
+	}
+
+	dev->real_num_rx_queues = rxq;
+	return 0;
+}
+EXPORT_SYMBOL(netif_set_real_num_rx_queues);
+#endif
+
+/**
+ * netif_get_num_default_rss_queues - default number of RSS queues
+ *
+ * This routine should set an upper limit on the number of RSS queues
+ * used by default by multiqueue devices.
+ */
+int netif_get_num_default_rss_queues(void)
+{
+	return is_kdump_kernel() ?
+		1 : min_t(int, DEFAULT_MAX_NUM_RSS_QUEUES, num_online_cpus());
+}
+EXPORT_SYMBOL(netif_get_num_default_rss_queues);
+
+static void __netif_reschedule(struct Qdisc *q)
+{
+	struct softnet_data *sd;
+	unsigned long flags;
+
+	local_irq_save(flags);
+	sd = this_cpu_ptr(&softnet_data);
+	q->next_sched = NULL;
+	*sd->output_queue_tailp = q;
+	sd->output_queue_tailp = &q->next_sched;
+	raise_softirq_irqoff(NET_TX_SOFTIRQ);
+	local_irq_restore(flags);
+}
+
+void __netif_schedule(struct Qdisc *q)
+{
+	if (!test_and_set_bit(__QDISC_STATE_SCHED, &q->state))
+		__netif_reschedule(q);
+}
+EXPORT_SYMBOL(__netif_schedule);
+
+struct dev_kfree_skb_cb {
+	enum skb_free_reason reason;
+};
+
+static struct dev_kfree_skb_cb *get_kfree_skb_cb(const struct sk_buff *skb)
+{
+	return (struct dev_kfree_skb_cb *)skb->cb;
+}
+
+void netif_schedule_queue(struct netdev_queue *txq)
+{
+	rcu_read_lock();
+	if (!netif_xmit_stopped(txq)) {
+		struct Qdisc *q = rcu_dereference(txq->qdisc);
+
+		__netif_schedule(q);
+	}
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(netif_schedule_queue);
+
+void netif_tx_wake_queue(struct netdev_queue *dev_queue)
+{
+	if (test_and_clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state)) {
+		struct Qdisc *q;
+
+		rcu_read_lock();
+		q = rcu_dereference(dev_queue->qdisc);
+		__netif_schedule(q);
+		rcu_read_unlock();
+	}
+}
+EXPORT_SYMBOL(netif_tx_wake_queue);
+
+void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason)
+{
+	unsigned long flags;
+
+	if (unlikely(!skb))
+		return;
+
+	if (likely(refcount_read(&skb->users) == 1)) {
+		smp_rmb();
+		refcount_set(&skb->users, 0);
+	} else if (likely(!refcount_dec_and_test(&skb->users))) {
+		return;
+	}
+	get_kfree_skb_cb(skb)->reason = reason;
+	local_irq_save(flags);
+	skb->next = __this_cpu_read(softnet_data.completion_queue);
+	__this_cpu_write(softnet_data.completion_queue, skb);
+	raise_softirq_irqoff(NET_TX_SOFTIRQ);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(__dev_kfree_skb_irq);
+
+void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason)
+{
+	if (in_irq() || irqs_disabled())
+		__dev_kfree_skb_irq(skb, reason);
+	else if (unlikely(reason == SKB_REASON_DROPPED))
+		kfree_skb(skb);
+	else
+		consume_skb(skb);
+}
+EXPORT_SYMBOL(__dev_kfree_skb_any);
+
+
+/**
+ * netif_device_detach - mark device as removed
+ * @dev: network device
+ *
+ * Mark device as removed from system and therefore no longer available.
+ */
+void netif_device_detach(struct net_device *dev)
+{
+	if (test_and_clear_bit(__LINK_STATE_PRESENT, &dev->state) &&
+	    netif_running(dev)) {
+		netif_tx_stop_all_queues(dev);
+	}
+}
+EXPORT_SYMBOL(netif_device_detach);
+
+/**
+ * netif_device_attach - mark device as attached
+ * @dev: network device
+ *
+ * Mark device as attached from system and restart if needed.
+ */
+void netif_device_attach(struct net_device *dev)
+{
+	if (!test_and_set_bit(__LINK_STATE_PRESENT, &dev->state) &&
+	    netif_running(dev)) {
+		netif_tx_wake_all_queues(dev);
+		__netdev_watchdog_up(dev);
+	}
+}
+EXPORT_SYMBOL(netif_device_attach);
+
+/*
+ * Returns a Tx hash based on the given packet descriptor a Tx queues' number
+ * to be used as a distribution range.
+ */
+static u16 skb_tx_hash(const struct net_device *dev,
+		       const struct net_device *sb_dev,
+		       struct sk_buff *skb)
+{
+	u32 hash;
+	u16 qoffset = 0;
+	u16 qcount = dev->real_num_tx_queues;
+
+	if (dev->num_tc) {
+		u8 tc = netdev_get_prio_tc_map(dev, skb->priority);
+
+		qoffset = sb_dev->tc_to_txq[tc].offset;
+		qcount = sb_dev->tc_to_txq[tc].count;
+		if (unlikely(!qcount)) {
+			net_warn_ratelimited("%s: invalid qcount, qoffset %u for tc %u\n",
+					     sb_dev->name, qoffset, tc);
+			qoffset = 0;
+			qcount = dev->real_num_tx_queues;
+		}
+	}
+
+	if (skb_rx_queue_recorded(skb)) {
+		hash = skb_get_rx_queue(skb);
+		if (hash >= qoffset)
+			hash -= qoffset;
+		while (unlikely(hash >= qcount))
+			hash -= qcount;
+		return hash + qoffset;
+	}
+
+	return (u16) reciprocal_scale(skb_get_hash(skb), qcount) + qoffset;
+}
+
+static void skb_warn_bad_offload(const struct sk_buff *skb)
+{
+	static const netdev_features_t null_features;
+	struct net_device *dev = skb->dev;
+	const char *name = "";
+
+	if (!net_ratelimit())
+		return;
+
+	if (dev) {
+		if (dev->dev.parent)
+			name = dev_driver_string(dev->dev.parent);
+		else
+			name = netdev_name(dev);
+	}
+	skb_dump(KERN_WARNING, skb, false);
+	WARN(1, "%s: caps=(%pNF, %pNF)\n",
+	     name, dev ? &dev->features : &null_features,
+	     skb->sk ? &skb->sk->sk_route_caps : &null_features);
+}
+
+/*
+ * Invalidate hardware checksum when packet is to be mangled, and
+ * complete checksum manually on outgoing path.
+ */
+int skb_checksum_help(struct sk_buff *skb)
+{
+	__wsum csum;
+	int ret = 0, offset;
+
+	if (skb->ip_summed == CHECKSUM_COMPLETE)
+		goto out_set_summed;
+
+	if (unlikely(skb_shinfo(skb)->gso_size)) {
+		skb_warn_bad_offload(skb);
+		return -EINVAL;
+	}
+
+	/* Before computing a checksum, we should make sure no frag could
+	 * be modified by an external entity : checksum could be wrong.
+	 */
+	if (skb_has_shared_frag(skb)) {
+		ret = __skb_linearize(skb);
+		if (ret)
+			goto out;
+	}
+
+	offset = skb_checksum_start_offset(skb);
+	ret = -EINVAL;
+	if (WARN_ON_ONCE(offset >= skb_headlen(skb)))
+		goto out;
+
+	csum = skb_checksum(skb, offset, skb->len - offset, 0);
+
+	offset += skb->csum_offset;
+	if (WARN_ON_ONCE(offset + sizeof(__sum16) > skb_headlen(skb)))
+		goto out;
+
+	ret = skb_ensure_writable(skb, offset + sizeof(__sum16));
+	if (ret)
+		goto out;
+
+	*(__sum16 *)(skb->data + offset) = csum_fold(csum) ?: CSUM_MANGLED_0;
+out_set_summed:
+	skb->ip_summed = CHECKSUM_NONE;
+out:
+	return ret;
+}
+EXPORT_SYMBOL(skb_checksum_help);
+
+int skb_crc32c_csum_help(struct sk_buff *skb)
+{
+	__le32 crc32c_csum;
+	int ret = 0, offset, start;
+
+	if (skb->ip_summed != CHECKSUM_PARTIAL)
+		goto out;
+
+	if (unlikely(skb_is_gso(skb)))
+		goto out;
+
+	/* Before computing a checksum, we should make sure no frag could
+	 * be modified by an external entity : checksum could be wrong.
+	 */
+	if (unlikely(skb_has_shared_frag(skb))) {
+		ret = __skb_linearize(skb);
+		if (ret)
+			goto out;
+	}
+	start = skb_checksum_start_offset(skb);
+	offset = start + offsetof(struct sctphdr, checksum);
+	if (WARN_ON_ONCE(offset >= skb_headlen(skb))) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	ret = skb_ensure_writable(skb, offset + sizeof(__le32));
+	if (ret)
+		goto out;
+
+	crc32c_csum = cpu_to_le32(~__skb_checksum(skb, start,
+						  skb->len - start, ~(__u32)0,
+						  crc32c_csum_stub));
+	*(__le32 *)(skb->data + offset) = crc32c_csum;
+	skb->ip_summed = CHECKSUM_NONE;
+	skb->csum_not_inet = 0;
+out:
+	return ret;
+}
+
+__be16 skb_network_protocol(struct sk_buff *skb, int *depth)
+{
+	__be16 type = skb->protocol;
+
+	/* Tunnel gso handlers can set protocol to ethernet. */
+	if (type == htons(ETH_P_TEB)) {
+		struct ethhdr *eth;
+
+		if (unlikely(!pskb_may_pull(skb, sizeof(struct ethhdr))))
+			return 0;
+
+		eth = (struct ethhdr *)skb->data;
+		type = eth->h_proto;
+	}
+
+	return vlan_get_protocol_and_depth(skb, type, depth);
+}
+
+/**
+ *	skb_mac_gso_segment - mac layer segmentation handler.
+ *	@skb: buffer to segment
+ *	@features: features for the output path (see dev->features)
+ */
+struct sk_buff *skb_mac_gso_segment(struct sk_buff *skb,
+				    netdev_features_t features)
+{
+	struct sk_buff *segs = ERR_PTR(-EPROTONOSUPPORT);
+	struct packet_offload *ptype;
+	int vlan_depth = skb->mac_len;
+	__be16 type = skb_network_protocol(skb, &vlan_depth);
+
+	if (unlikely(!type))
+		return ERR_PTR(-EINVAL);
+
+	__skb_pull(skb, vlan_depth);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ptype, &offload_base, list) {
+		if (ptype->type == type && ptype->callbacks.gso_segment) {
+			segs = ptype->callbacks.gso_segment(skb, features);
+			break;
+		}
+	}
+	rcu_read_unlock();
+
+	__skb_push(skb, skb->data - skb_mac_header(skb));
+
+	return segs;
+}
+EXPORT_SYMBOL(skb_mac_gso_segment);
+
+
+/* openvswitch calls this on rx path, so we need a different check.
+ */
+static inline bool skb_needs_check(struct sk_buff *skb, bool tx_path)
+{
+	if (tx_path)
+		return skb->ip_summed != CHECKSUM_PARTIAL &&
+		       skb->ip_summed != CHECKSUM_UNNECESSARY;
+
+	return skb->ip_summed == CHECKSUM_NONE;
+}
+
+/**
+ *	__skb_gso_segment - Perform segmentation on skb.
+ *	@skb: buffer to segment
+ *	@features: features for the output path (see dev->features)
+ *	@tx_path: whether it is called in TX path
+ *
+ *	This function segments the given skb and returns a list of segments.
+ *
+ *	It may return NULL if the skb requires no segmentation.  This is
+ *	only possible when GSO is used for verifying header integrity.
+ *
+ *	Segmentation preserves SKB_GSO_CB_OFFSET bytes of previous skb cb.
+ */
+struct sk_buff *__skb_gso_segment(struct sk_buff *skb,
+				  netdev_features_t features, bool tx_path)
+{
+	struct sk_buff *segs;
+
+	if (unlikely(skb_needs_check(skb, tx_path))) {
+		int err;
+
+		/* We're going to init ->check field in TCP or UDP header */
+		err = skb_cow_head(skb, 0);
+		if (err < 0)
+			return ERR_PTR(err);
+	}
+
+	/* Only report GSO partial support if it will enable us to
+	 * support segmentation on this frame without needing additional
+	 * work.
+	 */
+	if (features & NETIF_F_GSO_PARTIAL) {
+		netdev_features_t partial_features = NETIF_F_GSO_ROBUST;
+		struct net_device *dev = skb->dev;
+
+		partial_features |= dev->features & dev->gso_partial_features;
+		if (!skb_gso_ok(skb, features | partial_features))
+			features &= ~NETIF_F_GSO_PARTIAL;
+	}
+
+	BUILD_BUG_ON(SKB_GSO_CB_OFFSET +
+		     sizeof(*SKB_GSO_CB(skb)) > sizeof(skb->cb));
+
+	SKB_GSO_CB(skb)->mac_offset = skb_headroom(skb);
+	SKB_GSO_CB(skb)->encap_level = 0;
+
+	skb_reset_mac_header(skb);
+	skb_reset_mac_len(skb);
+
+	segs = skb_mac_gso_segment(skb, features);
+
+	if (segs != skb && unlikely(skb_needs_check(skb, tx_path) && !IS_ERR(segs)))
+		skb_warn_bad_offload(skb);
+
+	return segs;
+}
+EXPORT_SYMBOL(__skb_gso_segment);
+
+/* Take action when hardware reception checksum errors are detected. */
+#ifdef CONFIG_BUG
+void netdev_rx_csum_fault(struct net_device *dev, struct sk_buff *skb)
+{
+	if (net_ratelimit()) {
+		pr_err("%s: hw csum failure\n", dev ? dev->name : "<unknown>");
+		skb_dump(KERN_ERR, skb, true);
+		dump_stack();
+	}
+}
+EXPORT_SYMBOL(netdev_rx_csum_fault);
+#endif
+
+/* XXX: check that highmem exists at all on the given machine. */
+static int illegal_highdma(struct net_device *dev, struct sk_buff *skb)
+{
+#ifdef CONFIG_HIGHMEM
+	int i;
+
+	if (!(dev->features & NETIF_F_HIGHDMA)) {
+		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
+			skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+			if (PageHighMem(skb_frag_page(frag)))
+				return 1;
+		}
+	}
+#endif
+	return 0;
+}
+
+/* If MPLS offload request, verify we are testing hardware MPLS features
+ * instead of standard features for the netdev.
+ */
+#if IS_ENABLED(CONFIG_NET_MPLS_GSO)
+static netdev_features_t net_mpls_features(struct sk_buff *skb,
+					   netdev_features_t features,
+					   __be16 type)
+{
+	if (eth_p_mpls(type))
+		features &= skb->dev->mpls_features;
+
+	return features;
+}
+#else
+static netdev_features_t net_mpls_features(struct sk_buff *skb,
+					   netdev_features_t features,
+					   __be16 type)
+{
+	return features;
+}
+#endif
+
+static netdev_features_t harmonize_features(struct sk_buff *skb,
+	netdev_features_t features)
+{
+	__be16 type;
+
+	type = skb_network_protocol(skb, NULL);
+	features = net_mpls_features(skb, features, type);
+
+	if (skb->ip_summed != CHECKSUM_NONE &&
+	    !can_checksum_protocol(features, type)) {
+		features &= ~(NETIF_F_CSUM_MASK | NETIF_F_GSO_MASK);
+	}
+	if (illegal_highdma(skb->dev, skb))
+		features &= ~NETIF_F_SG;
+
+	return features;
+}
+
+netdev_features_t passthru_features_check(struct sk_buff *skb,
+					  struct net_device *dev,
+					  netdev_features_t features)
+{
+	return features;
+}
+EXPORT_SYMBOL(passthru_features_check);
+
+static netdev_features_t dflt_features_check(struct sk_buff *skb,
+					     struct net_device *dev,
+					     netdev_features_t features)
+{
+	return vlan_features_check(skb, features);
+}
+
+static netdev_features_t gso_features_check(const struct sk_buff *skb,
+					    struct net_device *dev,
+					    netdev_features_t features)
+{
+	u16 gso_segs = skb_shinfo(skb)->gso_segs;
+
+	if (gso_segs > dev->gso_max_segs)
+		return features & ~NETIF_F_GSO_MASK;
+
+	if (unlikely(skb->len >= READ_ONCE(dev->gso_max_size)))
+		return features & ~NETIF_F_GSO_MASK;
+
+	if (!skb_shinfo(skb)->gso_type) {
+		skb_warn_bad_offload(skb);
+		return features & ~NETIF_F_GSO_MASK;
+	}
+
+	/* Support for GSO partial features requires software
+	 * intervention before we can actually process the packets
+	 * so we need to strip support for any partial features now
+	 * and we can pull them back in after we have partially
+	 * segmented the frame.
+	 */
+	if (!(skb_shinfo(skb)->gso_type & SKB_GSO_PARTIAL))
+		features &= ~dev->gso_partial_features;
+
+	/* Make sure to clear the IPv4 ID mangling feature if the
+	 * IPv4 header has the potential to be fragmented.
+	 */
+	if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
+		struct iphdr *iph = skb->encapsulation ?
+				    inner_ip_hdr(skb) : ip_hdr(skb);
+
+		if (!(iph->frag_off & htons(IP_DF)))
+			features &= ~NETIF_F_TSO_MANGLEID;
+	}
+
+	return features;
+}
+
+netdev_features_t netif_skb_features(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	netdev_features_t features = dev->features;
+
+	if (skb_is_gso(skb))
+		features = gso_features_check(skb, dev, features);
+
+	/* If encapsulation offload request, verify we are testing
+	 * hardware encapsulation features instead of standard
+	 * features for the netdev
+	 */
+	if (skb->encapsulation)
+		features &= dev->hw_enc_features;
+
+	if (skb_vlan_tagged(skb))
+		features = netdev_intersect_features(features,
+						     dev->vlan_features |
+						     NETIF_F_HW_VLAN_CTAG_TX |
+						     NETIF_F_HW_VLAN_STAG_TX);
+
+	if (dev->netdev_ops->ndo_features_check)
+		features &= dev->netdev_ops->ndo_features_check(skb, dev,
+								features);
+	else
+		features &= dflt_features_check(skb, dev, features);
+
+	return harmonize_features(skb, features);
+}
+EXPORT_SYMBOL(netif_skb_features);
+
+static int xmit_one(struct sk_buff *skb, struct net_device *dev,
+		    struct netdev_queue *txq, bool more)
+{
+	unsigned int len;
+	int rc;
+
+	if (dev_nit_active(dev))
+		dev_queue_xmit_nit(skb, dev);
+
+	len = skb->len;
+	PRANDOM_ADD_NOISE(skb, dev, txq, len + jiffies);
+	trace_net_dev_start_xmit(skb, dev);
+	rc = netdev_start_xmit(skb, dev, txq, more);
+	trace_net_dev_xmit(skb, rc, dev, len);
+
+	return rc;
+}
+
+struct sk_buff *dev_hard_start_xmit(struct sk_buff *first, struct net_device *dev,
+				    struct netdev_queue *txq, int *ret)
+{
+	struct sk_buff *skb = first;
+	int rc = NETDEV_TX_OK;
+
+	while (skb) {
+		struct sk_buff *next = skb->next;
+
+		skb_mark_not_on_list(skb);
+		rc = xmit_one(skb, dev, txq, next != NULL);
+		if (unlikely(!dev_xmit_complete(rc))) {
+			skb->next = next;
+			goto out;
+		}
+
+		skb = next;
+		if (netif_tx_queue_stopped(txq) && skb) {
+			rc = NETDEV_TX_BUSY;
+			break;
+		}
+	}
+
+out:
+	*ret = rc;
+	return skb;
+}
+
+static struct sk_buff *validate_xmit_vlan(struct sk_buff *skb,
+					  netdev_features_t features)
+{
+	if (skb_vlan_tag_present(skb) &&
+	    !vlan_hw_offload_capable(features, skb->vlan_proto))
+		skb = __vlan_hwaccel_push_inside(skb);
+	return skb;
+}
+
+int skb_csum_hwoffload_help(struct sk_buff *skb,
+			    const netdev_features_t features)
+{
+	if (unlikely(skb_csum_is_sctp(skb)))
+		return !!(features & NETIF_F_SCTP_CRC) ? 0 :
+			skb_crc32c_csum_help(skb);
+
+	return !!(features & NETIF_F_CSUM_MASK) ? 0 : skb_checksum_help(skb);
+}
+EXPORT_SYMBOL(skb_csum_hwoffload_help);
+
+static struct sk_buff *validate_xmit_skb(struct sk_buff *skb, struct net_device *dev, bool *again)
+{
+	netdev_features_t features;
+
+	features = netif_skb_features(skb);
+	skb = validate_xmit_vlan(skb, features);
+	if (unlikely(!skb))
+		goto out_null;
+
+	skb = sk_validate_xmit_skb(skb, dev);
+	if (unlikely(!skb))
+		goto out_null;
+
+	if (netif_needs_gso(skb, features)) {
+		struct sk_buff *segs;
+
+		segs = skb_gso_segment(skb, features);
+		if (IS_ERR(segs)) {
+			goto out_kfree_skb;
+		} else if (segs) {
+			consume_skb(skb);
+			skb = segs;
+		}
+	} else {
+		if (skb_needs_linearize(skb, features) &&
+		    __skb_linearize(skb))
+			goto out_kfree_skb;
+
+		/* If packet is not checksummed and device does not
+		 * support checksumming for this protocol, complete
+		 * checksumming here.
+		 */
+		if (skb->ip_summed == CHECKSUM_PARTIAL) {
+			if (skb->encapsulation)
+				skb_set_inner_transport_header(skb,
+							       skb_checksum_start_offset(skb));
+			else
+				skb_set_transport_header(skb,
+							 skb_checksum_start_offset(skb));
+			if (skb_csum_hwoffload_help(skb, features))
+				goto out_kfree_skb;
+		}
+	}
+
+	skb = validate_xmit_xfrm(skb, features, again);
+
+	return skb;
+
+out_kfree_skb:
+	kfree_skb(skb);
+out_null:
+	atomic_long_inc(&dev->tx_dropped);
+	return NULL;
+}
+
+struct sk_buff *validate_xmit_skb_list(struct sk_buff *skb, struct net_device *dev, bool *again)
+{
+	struct sk_buff *next, *head = NULL, *tail;
+
+	for (; skb != NULL; skb = next) {
+		next = skb->next;
+		skb_mark_not_on_list(skb);
+
+		/* in case skb wont be segmented, point to itself */
+		skb->prev = skb;
+
+		skb = validate_xmit_skb(skb, dev, again);
+		if (!skb)
+			continue;
+
+		if (!head)
+			head = skb;
+		else
+			tail->next = skb;
+		/* If skb was segmented, skb->prev points to
+		 * the last segment. If not, it still contains skb.
+		 */
+		tail = skb->prev;
+	}
+	return head;
+}
+EXPORT_SYMBOL_GPL(validate_xmit_skb_list);
+
+static void qdisc_pkt_len_init(struct sk_buff *skb)
+{
+	const struct skb_shared_info *shinfo = skb_shinfo(skb);
+
+	qdisc_skb_cb(skb)->pkt_len = skb->len;
+
+	/* To get more precise estimation of bytes sent on wire,
+	 * we add to pkt_len the headers size of all segments
+	 */
+	if (shinfo->gso_size && skb_transport_header_was_set(skb)) {
+		unsigned int hdr_len;
+		u16 gso_segs = shinfo->gso_segs;
+
+		/* mac layer + network layer */
+		hdr_len = skb_transport_header(skb) - skb_mac_header(skb);
+
+		/* + transport layer */
+		if (likely(shinfo->gso_type & (SKB_GSO_TCPV4 | SKB_GSO_TCPV6))) {
+			const struct tcphdr *th;
+			struct tcphdr _tcphdr;
+
+			th = skb_header_pointer(skb, skb_transport_offset(skb),
+						sizeof(_tcphdr), &_tcphdr);
+			if (likely(th))
+				hdr_len += __tcp_hdrlen(th);
+		} else {
+			struct udphdr _udphdr;
+
+			if (skb_header_pointer(skb, skb_transport_offset(skb),
+					       sizeof(_udphdr), &_udphdr))
+				hdr_len += sizeof(struct udphdr);
+		}
+
+		if (shinfo->gso_type & SKB_GSO_DODGY)
+			gso_segs = DIV_ROUND_UP(skb->len - hdr_len,
+						shinfo->gso_size);
+
+		qdisc_skb_cb(skb)->pkt_len += (gso_segs - 1) * hdr_len;
+	}
+}
+
+static inline int __dev_xmit_skb(struct sk_buff *skb, struct Qdisc *q,
+				 struct net_device *dev,
+				 struct netdev_queue *txq)
+{
+	spinlock_t *root_lock = qdisc_lock(q);
+	struct sk_buff *to_free = NULL;
+	bool contended;
+	int rc;
+
+	qdisc_calculate_pkt_len(skb, q);
+
+	if (q->flags & TCQ_F_NOLOCK) {
+		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
+		if (likely(!netif_xmit_frozen_or_stopped(txq)))
+			qdisc_run(q);
+
+		if (unlikely(to_free))
+			kfree_skb_list(to_free);
+		return rc;
+	}
+
+	/*
+	 * Heuristic to force contended enqueues to serialize on a
+	 * separate lock before trying to get qdisc main lock.
+	 * This permits qdisc->running owner to get the lock more
+	 * often and dequeue packets faster.
+	 */
+	contended = qdisc_is_running(q);
+	if (unlikely(contended))
+		spin_lock(&q->busylock);
+
+	spin_lock(root_lock);
+	if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED, &q->state))) {
+		__qdisc_drop(skb, &to_free);
+		rc = NET_XMIT_DROP;
+	} else if ((q->flags & TCQ_F_CAN_BYPASS) && !qdisc_qlen(q) &&
+		   qdisc_run_begin(q)) {
+		/*
+		 * This is a work-conserving queue; there are no old skbs
+		 * waiting to be sent out; and the qdisc is not running -
+		 * xmit the skb directly.
+		 */
+
+		qdisc_bstats_update(q, skb);
+
+		if (sch_direct_xmit(skb, q, dev, txq, root_lock, true)) {
+			if (unlikely(contended)) {
+				spin_unlock(&q->busylock);
+				contended = false;
+			}
+			__qdisc_run(q);
+		}
+
+		qdisc_run_end(q);
+		rc = NET_XMIT_SUCCESS;
+	} else {
+		rc = q->enqueue(skb, q, &to_free) & NET_XMIT_MASK;
+		if (qdisc_run_begin(q)) {
+			if (unlikely(contended)) {
+				spin_unlock(&q->busylock);
+				contended = false;
+			}
+			__qdisc_run(q);
+			qdisc_run_end(q);
+		}
+	}
+	spin_unlock(root_lock);
+	if (unlikely(to_free))
+		kfree_skb_list(to_free);
+	if (unlikely(contended))
+		spin_unlock(&q->busylock);
+	return rc;
+}
+
+#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
+static void skb_update_prio(struct sk_buff *skb)
+{
+	const struct netprio_map *map;
+	const struct sock *sk;
+	unsigned int prioidx;
+
+	if (skb->priority)
+		return;
+	map = rcu_dereference_bh(skb->dev->priomap);
+	if (!map)
+		return;
+	sk = skb_to_full_sk(skb);
+	if (!sk)
+		return;
+
+	prioidx = sock_cgroup_prioidx(&sk->sk_cgrp_data);
+
+	if (prioidx < map->priomap_len)
+		skb->priority = map->priomap[prioidx];
+}
+#else
+#define skb_update_prio(skb)
+#endif
+
+/**
+ *	dev_loopback_xmit - loop back @skb
+ *	@net: network namespace this loopback is happening in
+ *	@sk:  sk needed to be a netfilter okfn
+ *	@skb: buffer to transmit
+ */
+int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *skb)
+{
+	skb_reset_mac_header(skb);
+	__skb_pull(skb, skb_network_offset(skb));
+	skb->pkt_type = PACKET_LOOPBACK;
+	if (skb->ip_summed == CHECKSUM_NONE)
+		skb->ip_summed = CHECKSUM_UNNECESSARY;
+	WARN_ON(!skb_dst(skb));
+	skb_dst_force(skb);
+	netif_rx_ni(skb);
+	return 0;
+}
+EXPORT_SYMBOL(dev_loopback_xmit);
+
+#ifdef CONFIG_NET_EGRESS
+static struct sk_buff *
+sch_handle_egress(struct sk_buff *skb, int *ret, struct net_device *dev)
+{
+	struct mini_Qdisc *miniq = rcu_dereference_bh(dev->miniq_egress);
+	struct tcf_result cl_res;
+
+	if (!miniq)
+		return skb;
+
+	/* qdisc_skb_cb(skb)->pkt_len was already set by the caller. */
+	qdisc_skb_cb(skb)->mru = 0;
+	mini_qdisc_bstats_cpu_update(miniq, skb);
+
+	switch (tcf_classify(skb, miniq->filter_list, &cl_res, false)) {
+	case TC_ACT_OK:
+	case TC_ACT_RECLASSIFY:
+		skb->tc_index = TC_H_MIN(cl_res.classid);
+		break;
+	case TC_ACT_SHOT:
+		mini_qdisc_qstats_cpu_drop(miniq);
+		*ret = NET_XMIT_DROP;
+		kfree_skb(skb);
+		return NULL;
+	case TC_ACT_STOLEN:
+	case TC_ACT_QUEUED:
+	case TC_ACT_TRAP:
+		*ret = NET_XMIT_SUCCESS;
+		consume_skb(skb);
+		return NULL;
+	case TC_ACT_REDIRECT:
+		/* No need to push/pop skb's mac_header here on egress! */
+		skb_do_redirect(skb);
+		*ret = NET_XMIT_SUCCESS;
+		return NULL;
+	default:
+		break;
+	}
+
+	return skb;
+}
+#endif /* CONFIG_NET_EGRESS */
+
+#ifdef CONFIG_XPS
+static int __get_xps_queue_idx(struct net_device *dev, struct sk_buff *skb,
+			       struct xps_dev_maps *dev_maps, unsigned int tci)
+{
+	struct xps_map *map;
+	int queue_index = -1;
+
+	if (dev->num_tc) {
+		tci *= dev->num_tc;
+		tci += netdev_get_prio_tc_map(dev, skb->priority);
+	}
+
+	map = rcu_dereference(dev_maps->attr_map[tci]);
+	if (map) {
+		if (map->len == 1)
+			queue_index = map->queues[0];
+		else
+			queue_index = map->queues[reciprocal_scale(
+						skb_get_hash(skb), map->len)];
+		if (unlikely(queue_index >= dev->real_num_tx_queues))
+			queue_index = -1;
+	}
+	return queue_index;
+}
+#endif
+
+static int get_xps_queue(struct net_device *dev, struct net_device *sb_dev,
+			 struct sk_buff *skb)
+{
+#ifdef CONFIG_XPS
+	struct xps_dev_maps *dev_maps;
+	struct sock *sk = skb->sk;
+	int queue_index = -1;
+
+	if (!static_key_false(&xps_needed))
+		return -1;
+
+	rcu_read_lock();
+	if (!static_key_false(&xps_rxqs_needed))
+		goto get_cpus_map;
+
+	dev_maps = rcu_dereference(sb_dev->xps_rxqs_map);
+	if (dev_maps) {
+		int tci = sk_rx_queue_get(sk);
+
+		if (tci >= 0 && tci < dev->num_rx_queues)
+			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
+							  tci);
+	}
+
+get_cpus_map:
+	if (queue_index < 0) {
+		dev_maps = rcu_dereference(sb_dev->xps_cpus_map);
+		if (dev_maps) {
+			unsigned int tci = skb->sender_cpu - 1;
+
+			queue_index = __get_xps_queue_idx(dev, skb, dev_maps,
+							  tci);
+		}
+	}
+	rcu_read_unlock();
+
+	return queue_index;
+#else
+	return -1;
+#endif
+}
+
+u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
+		     struct net_device *sb_dev)
+{
+	return 0;
+}
+EXPORT_SYMBOL(dev_pick_tx_zero);
+
+u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
+		       struct net_device *sb_dev)
+{
+	return (u16)raw_smp_processor_id() % dev->real_num_tx_queues;
+}
+EXPORT_SYMBOL(dev_pick_tx_cpu_id);
+
+u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
+		     struct net_device *sb_dev)
+{
+	struct sock *sk = skb->sk;
+	int queue_index = sk_tx_queue_get(sk);
+
+	sb_dev = sb_dev ? : dev;
+
+	if (queue_index < 0 || skb->ooo_okay ||
+	    queue_index >= dev->real_num_tx_queues) {
+		int new_index = get_xps_queue(dev, sb_dev, skb);
+
+		if (new_index < 0)
+			new_index = skb_tx_hash(dev, sb_dev, skb);
+
+		if (queue_index != new_index && sk &&
+		    sk_fullsock(sk) &&
+		    rcu_access_pointer(sk->sk_dst_cache))
+			sk_tx_queue_set(sk, new_index);
+
+		queue_index = new_index;
+	}
+
+	return queue_index;
+}
+EXPORT_SYMBOL(netdev_pick_tx);
+
+struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
+					 struct sk_buff *skb,
+					 struct net_device *sb_dev)
+{
+	int queue_index = 0;
+
+#ifdef CONFIG_XPS
+	u32 sender_cpu = skb->sender_cpu - 1;
+
+	if (sender_cpu >= (u32)NR_CPUS)
+		skb->sender_cpu = raw_smp_processor_id() + 1;
+#endif
+
+	if (dev->real_num_tx_queues != 1) {
+		const struct net_device_ops *ops = dev->netdev_ops;
+
+		if (ops->ndo_select_queue)
+			queue_index = ops->ndo_select_queue(dev, skb, sb_dev);
+		else
+			queue_index = netdev_pick_tx(dev, skb, sb_dev);
+
+		queue_index = netdev_cap_txqueue(dev, queue_index);
+	}
+
+	skb_set_queue_mapping(skb, queue_index);
+	return netdev_get_tx_queue(dev, queue_index);
+}
+
+/**
+ *	__dev_queue_xmit - transmit a buffer
+ *	@skb: buffer to transmit
+ *	@sb_dev: suboordinate device used for L2 forwarding offload
+ *
+ *	Queue a buffer for transmission to a network device. The caller must
+ *	have set the device and priority and built the buffer before calling
+ *	this function. The function can be called from an interrupt.
+ *
+ *	A negative errno code is returned on a failure. A success does not
+ *	guarantee the frame will be transmitted as it may be dropped due
+ *	to congestion or traffic shaping.
+ *
+ * -----------------------------------------------------------------------------------
+ *      I notice this method can also return errors from the queue disciplines,
+ *      including NET_XMIT_DROP, which is a positive value.  So, errors can also
+ *      be positive.
+ *
+ *      Regardless of the return value, the skb is consumed, so it is currently
+ *      difficult to retry a send to this method.  (You can bump the ref count
+ *      before sending to hold a reference for retry if you are careful.)
+ *
+ *      When calling this method, interrupts MUST be enabled.  This is because
+ *      the BH enable code must have IRQs enabled so that it will not deadlock.
+ *          --BLG
+ */
+static int __dev_queue_xmit(struct sk_buff *skb, struct net_device *sb_dev)
+{
+	struct net_device *dev = skb->dev;
+	struct netdev_queue *txq;
+	struct Qdisc *q;
+	int rc = -ENOMEM;
+	bool again = false;
+
+	skb_reset_mac_header(skb);
+	skb_assert_len(skb);
+
+	if (unlikely(skb_shinfo(skb)->tx_flags & SKBTX_SCHED_TSTAMP))
+		__skb_tstamp_tx(skb, NULL, skb->sk, SCM_TSTAMP_SCHED);
+
+	/* Disable soft irqs for various locks below. Also
+	 * stops preemption for RCU.
+	 */
+	rcu_read_lock_bh();
+
+	skb_update_prio(skb);
+
+	qdisc_pkt_len_init(skb);
+#ifdef CONFIG_NET_CLS_ACT
+	skb->tc_at_ingress = 0;
+# ifdef CONFIG_NET_EGRESS
+	if (static_branch_unlikely(&egress_needed_key)) {
+		skb = sch_handle_egress(skb, &rc, dev);
+		if (!skb)
+			goto out;
+	}
+# endif
+#endif
+	/* If device/qdisc don't need skb->dst, release it right now while
+	 * its hot in this cpu cache.
+	 */
+	if (dev->priv_flags & IFF_XMIT_DST_RELEASE)
+		skb_dst_drop(skb);
+	else
+		skb_dst_force(skb);
+
+	txq = netdev_core_pick_tx(dev, skb, sb_dev);
+	q = rcu_dereference_bh(txq->qdisc);
+
+	trace_net_dev_queue(skb);
+	if (q->enqueue) {
+		rc = __dev_xmit_skb(skb, q, dev, txq);
+		goto out;
+	}
+
+	/* The device has no queue. Common case for software devices:
+	 * loopback, all the sorts of tunnels...
+
+	 * Really, it is unlikely that netif_tx_lock protection is necessary
+	 * here.  (f.e. loopback and IP tunnels are clean ignoring statistics
+	 * counters.)
+	 * However, it is possible, that they rely on protection
+	 * made by us here.
+
+	 * Check this and shot the lock. It is not prone from deadlocks.
+	 *Either shot noqueue qdisc, it is even simpler 8)
+	 */
+	if (dev->flags & IFF_UP) {
+		int cpu = smp_processor_id(); /* ok because BHs are off */
+
+		/* Other cpus might concurrently change txq->xmit_lock_owner
+		 * to -1 or to their cpu id, but not to our id.
+		 */
+		if (READ_ONCE(txq->xmit_lock_owner) != cpu) {
+			if (dev_xmit_recursion())
+				goto recursion_alert;
+
+			skb = validate_xmit_skb(skb, dev, &again);
+			if (!skb)
+				goto out;
+
+			PRANDOM_ADD_NOISE(skb, dev, txq, jiffies);
+			HARD_TX_LOCK(dev, txq, cpu);
+
+			if (!netif_xmit_stopped(txq)) {
+				dev_xmit_recursion_inc();
+				skb = dev_hard_start_xmit(skb, dev, txq, &rc);
+				dev_xmit_recursion_dec();
+				if (dev_xmit_complete(rc)) {
+					HARD_TX_UNLOCK(dev, txq);
+					goto out;
+				}
+			}
+			HARD_TX_UNLOCK(dev, txq);
+			net_crit_ratelimited("Virtual device %s asks to queue packet!\n",
+					     dev->name);
+		} else {
+			/* Recursion is detected! It is possible,
+			 * unfortunately
+			 */
+recursion_alert:
+			net_crit_ratelimited("Dead loop on virtual device %s, fix it urgently!\n",
+					     dev->name);
+		}
+	}
+
+	rc = -ENETDOWN;
+	rcu_read_unlock_bh();
+
+	atomic_long_inc(&dev->tx_dropped);
+	kfree_skb_list(skb);
+	return rc;
+out:
+	rcu_read_unlock_bh();
+	return rc;
+}
+
+int dev_queue_xmit(struct sk_buff *skb)
+{
+	return __dev_queue_xmit(skb, NULL);
+}
+EXPORT_SYMBOL(dev_queue_xmit);
+
+int dev_queue_xmit_accel(struct sk_buff *skb, struct net_device *sb_dev)
+{
+	return __dev_queue_xmit(skb, sb_dev);
+}
+EXPORT_SYMBOL(dev_queue_xmit_accel);
+
+int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
+{
+	struct net_device *dev = skb->dev;
+	struct sk_buff *orig_skb = skb;
+	struct netdev_queue *txq;
+	int ret = NETDEV_TX_BUSY;
+	bool again = false;
+
+	if (unlikely(!netif_running(dev) ||
+		     !netif_carrier_ok(dev)))
+		goto drop;
+
+	skb = validate_xmit_skb_list(skb, dev, &again);
+	if (skb != orig_skb)
+		goto drop;
+
+	skb_set_queue_mapping(skb, queue_id);
+	txq = skb_get_tx_queue(dev, skb);
+	PRANDOM_ADD_NOISE(skb, dev, txq, jiffies);
+
+	local_bh_disable();
+
+	dev_xmit_recursion_inc();
+	HARD_TX_LOCK(dev, txq, smp_processor_id());
+	if (!netif_xmit_frozen_or_drv_stopped(txq))
+		ret = netdev_start_xmit(skb, dev, txq, false);
+	HARD_TX_UNLOCK(dev, txq);
+	dev_xmit_recursion_dec();
+
+	local_bh_enable();
+	return ret;
+drop:
+	atomic_long_inc(&dev->tx_dropped);
+	kfree_skb_list(skb);
+	return NET_XMIT_DROP;
+}
+EXPORT_SYMBOL(__dev_direct_xmit);
+
+/*************************************************************************
+ *			Receiver routines
+ *************************************************************************/
+
+int netdev_max_backlog __read_mostly = 1000;
+EXPORT_SYMBOL(netdev_max_backlog);
+
+int netdev_tstamp_prequeue __read_mostly = 1;
+int netdev_budget __read_mostly = 300;
+/* Must be at least 2 jiffes to guarantee 1 jiffy timeout */
+unsigned int __read_mostly netdev_budget_usecs = 2 * USEC_PER_SEC / HZ;
+int weight_p __read_mostly = 64;           /* old backlog weight */
+int dev_weight_rx_bias __read_mostly = 1;  /* bias for backlog weight */
+int dev_weight_tx_bias __read_mostly = 1;  /* bias for output_queue quota */
+int dev_rx_weight __read_mostly = 64;
+int dev_tx_weight __read_mostly = 64;
+/* Maximum number of GRO_NORMAL skbs to batch up for list-RX */
+int gro_normal_batch __read_mostly = 8;
+
+/* Called with irq disabled */
+static inline void ____napi_schedule(struct softnet_data *sd,
+				     struct napi_struct *napi)
+{
+	list_add_tail(&napi->poll_list, &sd->poll_list);
+	__raise_softirq_irqoff(NET_RX_SOFTIRQ);
+}
+
+#ifdef CONFIG_RPS
+
+/* One global table that all flow-based protocols share. */
+struct rps_sock_flow_table __rcu *rps_sock_flow_table __read_mostly;
+EXPORT_SYMBOL(rps_sock_flow_table);
+u32 rps_cpu_mask __read_mostly;
+EXPORT_SYMBOL(rps_cpu_mask);
+
+struct static_key_false rps_needed __read_mostly;
+EXPORT_SYMBOL(rps_needed);
+struct static_key_false rfs_needed __read_mostly;
+EXPORT_SYMBOL(rfs_needed);
+
+static struct rps_dev_flow *
+set_rps_cpu(struct net_device *dev, struct sk_buff *skb,
+	    struct rps_dev_flow *rflow, u16 next_cpu)
+{
+	if (next_cpu < nr_cpu_ids) {
+#ifdef CONFIG_RFS_ACCEL
+		struct netdev_rx_queue *rxqueue;
+		struct rps_dev_flow_table *flow_table;
+		struct rps_dev_flow *old_rflow;
+		u32 flow_id;
+		u16 rxq_index;
+		int rc;
+
+		/* Should we steer this flow to a different hardware queue? */
+		if (!skb_rx_queue_recorded(skb) || !dev->rx_cpu_rmap ||
+		    !(dev->features & NETIF_F_NTUPLE))
+			goto out;
+		rxq_index = cpu_rmap_lookup_index(dev->rx_cpu_rmap, next_cpu);
+		if (rxq_index == skb_get_rx_queue(skb))
+			goto out;
+
+		rxqueue = dev->_rx + rxq_index;
+		flow_table = rcu_dereference(rxqueue->rps_flow_table);
+		if (!flow_table)
+			goto out;
+		flow_id = skb_get_hash(skb) & flow_table->mask;
+		rc = dev->netdev_ops->ndo_rx_flow_steer(dev, skb,
+							rxq_index, flow_id);
+		if (rc < 0)
+			goto out;
+		old_rflow = rflow;
+		rflow = &flow_table->flows[flow_id];
+		rflow->filter = rc;
+		if (old_rflow->filter == rflow->filter)
+			old_rflow->filter = RPS_NO_FILTER;
+	out:
+#endif
+		rflow->last_qtail =
+			per_cpu(softnet_data, next_cpu).input_queue_head;
+	}
+
+	rflow->cpu = next_cpu;
+	return rflow;
+}
+
+/*
+ * get_rps_cpu is called from netif_receive_skb and returns the target
+ * CPU from the RPS map of the receiving queue for a given skb.
+ * rcu_read_lock must be held on entry.
+ */
+static int get_rps_cpu(struct net_device *dev, struct sk_buff *skb,
+		       struct rps_dev_flow **rflowp)
+{
+	const struct rps_sock_flow_table *sock_flow_table;
+	struct netdev_rx_queue *rxqueue = dev->_rx;
+	struct rps_dev_flow_table *flow_table;
+	struct rps_map *map;
+	int cpu = -1;
+	u32 tcpu;
+	u32 hash;
+
+	if (skb_rx_queue_recorded(skb)) {
+		u16 index = skb_get_rx_queue(skb);
+
+		if (unlikely(index >= dev->real_num_rx_queues)) {
+			WARN_ONCE(dev->real_num_rx_queues > 1,
+				  "%s received packet on queue %u, but number "
+				  "of RX queues is %u\n",
+				  dev->name, index, dev->real_num_rx_queues);
+			goto done;
+		}
+		rxqueue += index;
+	}
+
+	/* Avoid computing hash if RFS/RPS is not active for this rxqueue */
+
+	flow_table = rcu_dereference(rxqueue->rps_flow_table);
+	map = rcu_dereference(rxqueue->rps_map);
+	if (!flow_table && !map)
+		goto done;
+
+	skb_reset_network_header(skb);
+	hash = skb_get_hash(skb);
+	if (!hash)
+		goto done;
+
+	sock_flow_table = rcu_dereference(rps_sock_flow_table);
+	if (flow_table && sock_flow_table) {
+		struct rps_dev_flow *rflow;
+		u32 next_cpu;
+		u32 ident;
+
+		/* First check into global flow table if there is a match.
+		 * This READ_ONCE() pairs with WRITE_ONCE() from rps_record_sock_flow().
+		 */
+		ident = READ_ONCE(sock_flow_table->ents[hash & sock_flow_table->mask]);
+		if ((ident ^ hash) & ~rps_cpu_mask)
+			goto try_rps;
+
+		next_cpu = ident & rps_cpu_mask;
+
+		/* OK, now we know there is a match,
+		 * we can look at the local (per receive queue) flow table
+		 */
+		rflow = &flow_table->flows[hash & flow_table->mask];
+		tcpu = rflow->cpu;
+
+		/*
+		 * If the desired CPU (where last recvmsg was done) is
+		 * different from current CPU (one in the rx-queue flow
+		 * table entry), switch if one of the following holds:
+		 *   - Current CPU is unset (>= nr_cpu_ids).
+		 *   - Current CPU is offline.
+		 *   - The current CPU's queue tail has advanced beyond the
+		 *     last packet that was enqueued using this table entry.
+		 *     This guarantees that all previous packets for the flow
+		 *     have been dequeued, thus preserving in order delivery.
+		 */
+		if (unlikely(tcpu != next_cpu) &&
+		    (tcpu >= nr_cpu_ids || !cpu_online(tcpu) ||
+		     ((int)(per_cpu(softnet_data, tcpu).input_queue_head -
+		      rflow->last_qtail)) >= 0)) {
+			tcpu = next_cpu;
+			rflow = set_rps_cpu(dev, skb, rflow, next_cpu);
+		}
+
+		if (tcpu < nr_cpu_ids && cpu_online(tcpu)) {
+			*rflowp = rflow;
+			cpu = tcpu;
+			goto done;
+		}
+	}
+
+try_rps:
+
+	if (map) {
+		tcpu = map->cpus[reciprocal_scale(hash, map->len)];
+		if (cpu_online(tcpu)) {
+			cpu = tcpu;
+			goto done;
+		}
+	}
+
+done:
+	return cpu;
+}
+
+#ifdef CONFIG_RFS_ACCEL
+
+/**
+ * rps_may_expire_flow - check whether an RFS hardware filter may be removed
+ * @dev: Device on which the filter was set
+ * @rxq_index: RX queue index
+ * @flow_id: Flow ID passed to ndo_rx_flow_steer()
+ * @filter_id: Filter ID returned by ndo_rx_flow_steer()
+ *
+ * Drivers that implement ndo_rx_flow_steer() should periodically call
+ * this function for each installed filter and remove the filters for
+ * which it returns %true.
+ */
+bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index,
+			 u32 flow_id, u16 filter_id)
+{
+	struct netdev_rx_queue *rxqueue = dev->_rx + rxq_index;
+	struct rps_dev_flow_table *flow_table;
+	struct rps_dev_flow *rflow;
+	bool expire = true;
+	unsigned int cpu;
+
+	rcu_read_lock();
+	flow_table = rcu_dereference(rxqueue->rps_flow_table);
+	if (flow_table && flow_id <= flow_table->mask) {
+		rflow = &flow_table->flows[flow_id];
+		cpu = READ_ONCE(rflow->cpu);
+		if (rflow->filter == filter_id && cpu < nr_cpu_ids &&
+		    ((int)(per_cpu(softnet_data, cpu).input_queue_head -
+			   rflow->last_qtail) <
+		     (int)(10 * flow_table->mask)))
+			expire = false;
+	}
+	rcu_read_unlock();
+	return expire;
+}
+EXPORT_SYMBOL(rps_may_expire_flow);
+
+#endif /* CONFIG_RFS_ACCEL */
+
+/* Called from hardirq (IPI) context */
+static void rps_trigger_softirq(void *data)
+{
+	struct softnet_data *sd = data;
+
+	____napi_schedule(sd, &sd->backlog);
+	sd->received_rps++;
+}
+
+#endif /* CONFIG_RPS */
+
+/*
+ * Check if this softnet_data structure is another cpu one
+ * If yes, queue it to our IPI list and return 1
+ * If no, return 0
+ */
+static int rps_ipi_queued(struct softnet_data *sd)
+{
+#ifdef CONFIG_RPS
+	struct softnet_data *mysd = this_cpu_ptr(&softnet_data);
+
+	if (sd != mysd) {
+		sd->rps_ipi_next = mysd->rps_ipi_list;
+		mysd->rps_ipi_list = sd;
+
+		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
+		return 1;
+	}
+#endif /* CONFIG_RPS */
+	return 0;
+}
+
+#ifdef CONFIG_NET_FLOW_LIMIT
+int netdev_flow_limit_table_len __read_mostly = (1 << 12);
+#endif
+
+static bool skb_flow_limit(struct sk_buff *skb, unsigned int qlen)
+{
+#ifdef CONFIG_NET_FLOW_LIMIT
+	struct sd_flow_limit *fl;
+	struct softnet_data *sd;
+	unsigned int old_flow, new_flow;
+
+	if (qlen < (READ_ONCE(netdev_max_backlog) >> 1))
+		return false;
+
+	sd = this_cpu_ptr(&softnet_data);
+
+	rcu_read_lock();
+	fl = rcu_dereference(sd->flow_limit);
+	if (fl) {
+		new_flow = skb_get_hash(skb) & (fl->num_buckets - 1);
+		old_flow = fl->history[fl->history_head];
+		fl->history[fl->history_head] = new_flow;
+
+		fl->history_head++;
+		fl->history_head &= FLOW_LIMIT_HISTORY - 1;
+
+		if (likely(fl->buckets[old_flow]))
+			fl->buckets[old_flow]--;
+
+		if (++fl->buckets[new_flow] > (FLOW_LIMIT_HISTORY >> 1)) {
+			fl->count++;
+			rcu_read_unlock();
+			return true;
+		}
+	}
+	rcu_read_unlock();
+#endif
+	return false;
+}
+
+/*
+ * enqueue_to_backlog is called to queue an skb to a per CPU backlog
+ * queue (may be a remote CPU queue).
+ */
+static int enqueue_to_backlog(struct sk_buff *skb, int cpu,
+			      unsigned int *qtail)
+{
+	struct softnet_data *sd;
+	unsigned long flags;
+	unsigned int qlen;
+
+	sd = &per_cpu(softnet_data, cpu);
+
+	local_irq_save(flags);
+
+	rps_lock(sd);
+	if (!netif_running(skb->dev))
+		goto drop;
+	qlen = skb_queue_len(&sd->input_pkt_queue);
+	if (qlen <= READ_ONCE(netdev_max_backlog) && !skb_flow_limit(skb, qlen)) {
+		if (qlen) {
+enqueue:
+			__skb_queue_tail(&sd->input_pkt_queue, skb);
+			input_queue_tail_incr_save(sd, qtail);
+			rps_unlock(sd);
+			local_irq_restore(flags);
+			return NET_RX_SUCCESS;
+		}
+
+		/* Schedule NAPI for backlog device
+		 * We can use non atomic operation since we own the queue lock
+		 */
+		if (!__test_and_set_bit(NAPI_STATE_SCHED, &sd->backlog.state)) {
+			if (!rps_ipi_queued(sd))
+				____napi_schedule(sd, &sd->backlog);
+		}
+		goto enqueue;
+	}
+
+drop:
+	sd->dropped++;
+	rps_unlock(sd);
+
+	local_irq_restore(flags);
+
+	atomic_long_inc(&skb->dev->rx_dropped);
+	kfree_skb(skb);
+	return NET_RX_DROP;
+}
+
+static struct netdev_rx_queue *netif_get_rxqueue(struct sk_buff *skb)
+{
+	struct net_device *dev = skb->dev;
+	struct netdev_rx_queue *rxqueue;
+
+	rxqueue = dev->_rx;
+
+	if (skb_rx_queue_recorded(skb)) {
+		u16 index = skb_get_rx_queue(skb);
+
+		if (unlikely(index >= dev->real_num_rx_queues)) {
+			WARN_ONCE(dev->real_num_rx_queues > 1,
+				  "%s received packet on queue %u, but number "
+				  "of RX queues is %u\n",
+				  dev->name, index, dev->real_num_rx_queues);
+
+			return rxqueue; /* Return first rxqueue */
+		}
+		rxqueue += index;
+	}
+	return rxqueue;
+}
+
+static u32 netif_receive_generic_xdp(struct sk_buff *skb,
+				     struct xdp_buff *xdp,
+				     struct bpf_prog *xdp_prog)
+{
+	struct netdev_rx_queue *rxqueue;
+	void *orig_data, *orig_data_end;
+	u32 metalen, act = XDP_DROP;
+	__be16 orig_eth_type;
+	struct ethhdr *eth;
+	bool orig_bcast;
+	int hlen, off;
+	u32 mac_len;
+
+	/* Reinjected packets coming from act_mirred or similar should
+	 * not get XDP generic processing.
+	 */
+	if (skb_is_redirected(skb))
+		return XDP_PASS;
+
+	/* XDP packets must be linear and must have sufficient headroom
+	 * of XDP_PACKET_HEADROOM bytes. This is the guarantee that also
+	 * native XDP provides, thus we need to do it here as well.
+	 */
+	if (skb_cloned(skb) || skb_is_nonlinear(skb) ||
+	    skb_headroom(skb) < XDP_PACKET_HEADROOM) {
+		int hroom = XDP_PACKET_HEADROOM - skb_headroom(skb);
+		int troom = skb->tail + skb->data_len - skb->end;
+
+		/* In case we have to go down the path and also linearize,
+		 * then lets do the pskb_expand_head() work just once here.
+		 */
+		if (pskb_expand_head(skb,
+				     hroom > 0 ? ALIGN(hroom, NET_SKB_PAD) : 0,
+				     troom > 0 ? troom + 128 : 0, GFP_ATOMIC))
+			goto do_drop;
+		if (skb_linearize(skb))
+			goto do_drop;
+	}
+
+	/* The XDP program wants to see the packet starting at the MAC
+	 * header.
+	 */
+	mac_len = skb->data - skb_mac_header(skb);
+	hlen = skb_headlen(skb) + mac_len;
+	xdp->data = skb->data - mac_len;
+	xdp->data_meta = xdp->data;
+	xdp->data_end = xdp->data + hlen;
+	xdp->data_hard_start = skb->data - skb_headroom(skb);
+
+	/* SKB "head" area always have tailroom for skb_shared_info */
+	xdp->frame_sz  = (void *)skb_end_pointer(skb) - xdp->data_hard_start;
+	xdp->frame_sz += SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+	orig_data_end = xdp->data_end;
+	orig_data = xdp->data;
+	eth = (struct ethhdr *)xdp->data;
+	orig_bcast = is_multicast_ether_addr_64bits(eth->h_dest);
+	orig_eth_type = eth->h_proto;
+
+	rxqueue = netif_get_rxqueue(skb);
+	xdp->rxq = &rxqueue->xdp_rxq;
+
+	act = bpf_prog_run_xdp(xdp_prog, xdp);
+
+	/* check if bpf_xdp_adjust_head was used */
+	off = xdp->data - orig_data;
+	if (off) {
+		if (off > 0)
+			__skb_pull(skb, off);
+		else if (off < 0)
+			__skb_push(skb, -off);
+
+		skb->mac_header += off;
+		skb_reset_network_header(skb);
+	}
+
+	/* check if bpf_xdp_adjust_tail was used */
+	off = xdp->data_end - orig_data_end;
+	if (off != 0) {
+		skb_set_tail_pointer(skb, xdp->data_end - xdp->data);
+		skb->len += off; /* positive on grow, negative on shrink */
+	}
+
+	/* check if XDP changed eth hdr such SKB needs update */
+	eth = (struct ethhdr *)xdp->data;
+	if ((orig_eth_type != eth->h_proto) ||
+	    (orig_bcast != is_multicast_ether_addr_64bits(eth->h_dest))) {
+		__skb_push(skb, ETH_HLEN);
+		skb->protocol = eth_type_trans(skb, skb->dev);
+	}
+
+	switch (act) {
+	case XDP_REDIRECT:
+	case XDP_TX:
+		__skb_push(skb, mac_len);
+		break;
+	case XDP_PASS:
+		metalen = xdp->data - xdp->data_meta;
+		if (metalen)
+			skb_metadata_set(skb, metalen);
+		break;
+	default:
+		bpf_warn_invalid_xdp_action(act);
+		fallthrough;
+	case XDP_ABORTED:
+		trace_xdp_exception(skb->dev, xdp_prog, act);
+		fallthrough;
+	case XDP_DROP:
+	do_drop:
+		kfree_skb(skb);
+		break;
+	}
+
+	return act;
+}
+
+/* When doing generic XDP we have to bypass the qdisc layer and the
+ * network taps in order to match in-driver-XDP behavior.
+ */
+void generic_xdp_tx(struct sk_buff *skb, struct bpf_prog *xdp_prog)
+{
+	struct net_device *dev = skb->dev;
+	struct netdev_queue *txq;
+	bool free_skb = true;
+	int cpu, rc;
+
+	txq = netdev_core_pick_tx(dev, skb, NULL);
+	cpu = smp_processor_id();
+	HARD_TX_LOCK(dev, txq, cpu);
+	if (!netif_xmit_stopped(txq)) {
+		rc = netdev_start_xmit(skb, dev, txq, 0);
+		if (dev_xmit_complete(rc))
+			free_skb = false;
+	}
+	HARD_TX_UNLOCK(dev, txq);
+	if (free_skb) {
+		trace_xdp_exception(dev, xdp_prog, XDP_TX);
+		kfree_skb(skb);
+	}
+}
+
+static DEFINE_STATIC_KEY_FALSE(generic_xdp_needed_key);
+
+int do_xdp_generic(struct bpf_prog *xdp_prog, struct sk_buff *skb)
+{
+	if (xdp_prog) {
+		struct xdp_buff xdp;
+		u32 act;
+		int err;
+
+		act = netif_receive_generic_xdp(skb, &xdp, xdp_prog);
+		if (act != XDP_PASS) {
+			switch (act) {
+			case XDP_REDIRECT:
+				err = xdp_do_generic_redirect(skb->dev, skb,
+							      &xdp, xdp_prog);
+				if (err)
+					goto out_redir;
+				break;
+			case XDP_TX:
+				generic_xdp_tx(skb, xdp_prog);
+				break;
+			}
+			return XDP_DROP;
+		}
+	}
+	return XDP_PASS;
+out_redir:
+	kfree_skb(skb);
+	return XDP_DROP;
+}
+EXPORT_SYMBOL_GPL(do_xdp_generic);
+
+static int netif_rx_internal(struct sk_buff *skb)
+{
+	int ret;
+
+	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
+
+	trace_netif_rx(skb);
+
+#ifdef CONFIG_RPS
+	if (static_branch_unlikely(&rps_needed)) {
+		struct rps_dev_flow voidflow, *rflow = &voidflow;
+		int cpu;
+
+		preempt_disable();
+		rcu_read_lock();
+
+		cpu = get_rps_cpu(skb->dev, skb, &rflow);
+		if (cpu < 0)
+			cpu = smp_processor_id();
+
+		ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
+
+		rcu_read_unlock();
+		preempt_enable();
+	} else
+#endif
+	{
+		unsigned int qtail;
+
+		ret = enqueue_to_backlog(skb, get_cpu(), &qtail);
+		put_cpu();
+	}
+	return ret;
+}
+
+/**
+ *	netif_rx	-	post buffer to the network code
+ *	@skb: buffer to post
+ *
+ *	This function receives a packet from a device driver and queues it for
+ *	the upper (protocol) levels to process.  It always succeeds. The buffer
+ *	may be dropped during processing for congestion control or by the
+ *	protocol layers.
+ *
+ *	return values:
+ *	NET_RX_SUCCESS	(no congestion)
+ *	NET_RX_DROP     (packet was dropped)
+ *
+ */
+
+int netif_rx(struct sk_buff *skb)
+{
+	int ret;
+
+	trace_netif_rx_entry(skb);
+
+	ret = netif_rx_internal(skb);
+	trace_netif_rx_exit(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(netif_rx);
+
+int netif_rx_ni(struct sk_buff *skb)
+{
+	int err;
+
+	trace_netif_rx_ni_entry(skb);
+
+	preempt_disable();
+	err = netif_rx_internal(skb);
+	if (local_softirq_pending())
+		do_softirq();
+	preempt_enable();
+	trace_netif_rx_ni_exit(err);
+
+	return err;
+}
+EXPORT_SYMBOL(netif_rx_ni);
+
+int netif_rx_any_context(struct sk_buff *skb)
+{
+	/*
+	 * If invoked from contexts which do not invoke bottom half
+	 * processing either at return from interrupt or when softrqs are
+	 * reenabled, use netif_rx_ni() which invokes bottomhalf processing
+	 * directly.
+	 */
+	if (in_interrupt())
+		return netif_rx(skb);
+	else
+		return netif_rx_ni(skb);
+}
+EXPORT_SYMBOL(netif_rx_any_context);
+
+static __latent_entropy void net_tx_action(struct softirq_action *h)
+{
+	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
+
+	if (sd->completion_queue) {
+		struct sk_buff *clist;
+
+		local_irq_disable();
+		clist = sd->completion_queue;
+		sd->completion_queue = NULL;
+		local_irq_enable();
+
+		while (clist) {
+			struct sk_buff *skb = clist;
+
+			clist = clist->next;
+
+			WARN_ON(refcount_read(&skb->users));
+			if (likely(get_kfree_skb_cb(skb)->reason == SKB_REASON_CONSUMED))
+				trace_consume_skb(skb);
+			else
+				trace_kfree_skb(skb, net_tx_action);
+
+			if (skb->fclone != SKB_FCLONE_UNAVAILABLE)
+				__kfree_skb(skb);
+			else
+				__kfree_skb_defer(skb);
+		}
+
+		__kfree_skb_flush();
+	}
+
+	if (sd->output_queue) {
+		struct Qdisc *head;
+
+		local_irq_disable();
+		head = sd->output_queue;
+		sd->output_queue = NULL;
+		sd->output_queue_tailp = &sd->output_queue;
+		local_irq_enable();
+
+		rcu_read_lock();
+
+		while (head) {
+			struct Qdisc *q = head;
+			spinlock_t *root_lock = NULL;
+
+			head = head->next_sched;
+
+			/* We need to make sure head->next_sched is read
+			 * before clearing __QDISC_STATE_SCHED
+			 */
+			smp_mb__before_atomic();
+
+			if (!(q->flags & TCQ_F_NOLOCK)) {
+				root_lock = qdisc_lock(q);
+				spin_lock(root_lock);
+			} else if (unlikely(test_bit(__QDISC_STATE_DEACTIVATED,
+						     &q->state))) {
+				/* There is a synchronize_net() between
+				 * STATE_DEACTIVATED flag being set and
+				 * qdisc_reset()/some_qdisc_is_busy() in
+				 * dev_deactivate(), so we can safely bail out
+				 * early here to avoid data race between
+				 * qdisc_deactivate() and some_qdisc_is_busy()
+				 * for lockless qdisc.
+				 */
+				clear_bit(__QDISC_STATE_SCHED, &q->state);
+				continue;
+			}
+
+			clear_bit(__QDISC_STATE_SCHED, &q->state);
+			qdisc_run(q);
+			if (root_lock)
+				spin_unlock(root_lock);
+		}
+
+		rcu_read_unlock();
+	}
+
+	xfrm_dev_backlog(sd);
+}
+
+#if IS_ENABLED(CONFIG_BRIDGE) && IS_ENABLED(CONFIG_ATM_LANE)
+/* This hook is defined here for ATM LANE */
+int (*br_fdb_test_addr_hook)(struct net_device *dev,
+			     unsigned char *addr) __read_mostly;
+EXPORT_SYMBOL_GPL(br_fdb_test_addr_hook);
+#endif
+
+static inline struct sk_buff *
+sch_handle_ingress(struct sk_buff *skb, struct packet_type **pt_prev, int *ret,
+		   struct net_device *orig_dev, bool *another)
+{
+#ifdef CONFIG_NET_CLS_ACT
+	struct mini_Qdisc *miniq = rcu_dereference_bh(skb->dev->miniq_ingress);
+	struct tcf_result cl_res;
+
+	/* If there's at least one ingress present somewhere (so
+	 * we get here via enabled static key), remaining devices
+	 * that are not configured with an ingress qdisc will bail
+	 * out here.
+	 */
+	if (!miniq)
+		return skb;
+
+	if (*pt_prev) {
+		*ret = deliver_skb(skb, *pt_prev, orig_dev);
+		*pt_prev = NULL;
+	}
+
+	qdisc_skb_cb(skb)->pkt_len = skb->len;
+	qdisc_skb_cb(skb)->mru = 0;
+	skb->tc_at_ingress = 1;
+	mini_qdisc_bstats_cpu_update(miniq, skb);
+
+	switch (tcf_classify_ingress(skb, miniq->block, miniq->filter_list,
+				     &cl_res, false)) {
+	case TC_ACT_OK:
+	case TC_ACT_RECLASSIFY:
+		skb->tc_index = TC_H_MIN(cl_res.classid);
+		break;
+	case TC_ACT_SHOT:
+		mini_qdisc_qstats_cpu_drop(miniq);
+		kfree_skb(skb);
+		return NULL;
+	case TC_ACT_STOLEN:
+	case TC_ACT_QUEUED:
+	case TC_ACT_TRAP:
+		consume_skb(skb);
+		return NULL;
+	case TC_ACT_REDIRECT:
+		/* skb_mac_header check was done by cls/act_bpf, so
+		 * we can safely push the L2 header back before
+		 * redirecting to another netdev
+		 */
+		__skb_push(skb, skb->mac_len);
+		if (skb_do_redirect(skb) == -EAGAIN) {
+			__skb_pull(skb, skb->mac_len);
+			*another = true;
+			break;
+		}
+		return NULL;
+	case TC_ACT_CONSUMED:
+		return NULL;
+	default:
+		break;
+	}
+#endif /* CONFIG_NET_CLS_ACT */
+	return skb;
+}
+
+/**
+ *	netdev_is_rx_handler_busy - check if receive handler is registered
+ *	@dev: device to check
+ *
+ *	Check if a receive handler is already registered for a given device.
+ *	Return true if there one.
+ *
+ *	The caller must hold the rtnl_mutex.
+ */
+bool netdev_is_rx_handler_busy(struct net_device *dev)
+{
+	ASSERT_RTNL();
+	return dev && rtnl_dereference(dev->rx_handler);
+}
+EXPORT_SYMBOL_GPL(netdev_is_rx_handler_busy);
+
+/**
+ *	netdev_rx_handler_register - register receive handler
+ *	@dev: device to register a handler for
+ *	@rx_handler: receive handler to register
+ *	@rx_handler_data: data pointer that is used by rx handler
+ *
+ *	Register a receive handler for a device. This handler will then be
+ *	called from __netif_receive_skb. A negative errno code is returned
+ *	on a failure.
+ *
+ *	The caller must hold the rtnl_mutex.
+ *
+ *	For a general description of rx_handler, see enum rx_handler_result.
+ */
+int netdev_rx_handler_register(struct net_device *dev,
+			       rx_handler_func_t *rx_handler,
+			       void *rx_handler_data)
+{
+	if (netdev_is_rx_handler_busy(dev))
+		return -EBUSY;
+
+	if (dev->priv_flags & IFF_NO_RX_HANDLER)
+		return -EINVAL;
+
+	/* Note: rx_handler_data must be set before rx_handler */
+	rcu_assign_pointer(dev->rx_handler_data, rx_handler_data);
+	rcu_assign_pointer(dev->rx_handler, rx_handler);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(netdev_rx_handler_register);
+
+/**
+ *	netdev_rx_handler_unregister - unregister receive handler
+ *	@dev: device to unregister a handler from
+ *
+ *	Unregister a receive handler from a device.
+ *
+ *	The caller must hold the rtnl_mutex.
+ */
+void netdev_rx_handler_unregister(struct net_device *dev)
+{
+
+	ASSERT_RTNL();
+	RCU_INIT_POINTER(dev->rx_handler, NULL);
+	/* a reader seeing a non NULL rx_handler in a rcu_read_lock()
+	 * section has a guarantee to see a non NULL rx_handler_data
+	 * as well.
+	 */
+	synchronize_net();
+	RCU_INIT_POINTER(dev->rx_handler_data, NULL);
+}
+EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);
+
+/*
+ * Limit the use of PFMEMALLOC reserves to those protocols that implement
+ * the special handling of PFMEMALLOC skbs.
+ */
+static bool skb_pfmemalloc_protocol(struct sk_buff *skb)
+{
+	switch (skb->protocol) {
+	case htons(ETH_P_ARP):
+	case htons(ETH_P_IP):
+	case htons(ETH_P_IPV6):
+	case htons(ETH_P_8021Q):
+	case htons(ETH_P_8021AD):
+		return true;
+	default:
+		return false;
+	}
+}
+
+static inline int nf_ingress(struct sk_buff *skb, struct packet_type **pt_prev,
+			     int *ret, struct net_device *orig_dev)
+{
+	if (nf_hook_ingress_active(skb)) {
+		int ingress_retval;
+
+		if (*pt_prev) {
+			*ret = deliver_skb(skb, *pt_prev, orig_dev);
+			*pt_prev = NULL;
+		}
+
+		rcu_read_lock();
+		ingress_retval = nf_hook_ingress(skb);
+		rcu_read_unlock();
+		return ingress_retval;
+	}
+	return 0;
+}
+
+static int __netif_receive_skb_core(struct sk_buff **pskb, bool pfmemalloc,
+				    struct packet_type **ppt_prev)
+{
+	struct packet_type *ptype, *pt_prev;
+	rx_handler_func_t *rx_handler;
+	struct sk_buff *skb = *pskb;
+	struct net_device *orig_dev;
+	bool deliver_exact = false;
+	int ret = NET_RX_DROP;
+	__be16 type;
+
+	net_timestamp_check(!READ_ONCE(netdev_tstamp_prequeue), skb);
+
+	trace_netif_receive_skb(skb);
+
+	orig_dev = skb->dev;
+
+	skb_reset_network_header(skb);
+	if (!skb_transport_header_was_set(skb))
+		skb_reset_transport_header(skb);
+	skb_reset_mac_len(skb);
+
+	pt_prev = NULL;
+
+another_round:
+	skb->skb_iif = skb->dev->ifindex;
+
+	__this_cpu_inc(softnet_data.processed);
+
+	if (static_branch_unlikely(&generic_xdp_needed_key)) {
+		int ret2;
+
+		preempt_disable();
+		ret2 = do_xdp_generic(rcu_dereference(skb->dev->xdp_prog), skb);
+		preempt_enable();
+
+		if (ret2 != XDP_PASS) {
+			ret = NET_RX_DROP;
+			goto out;
+		}
+		skb_reset_mac_len(skb);
+	}
+
+	if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
+	    skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
+		skb = skb_vlan_untag(skb);
+		if (unlikely(!skb))
+			goto out;
+	}
+
+	if (skb_skip_tc_classify(skb))
+		goto skip_classify;
+
+	if (pfmemalloc)
+		goto skip_taps;
+
+	list_for_each_entry_rcu(ptype, &ptype_all, list) {
+		if (pt_prev)
+			ret = deliver_skb(skb, pt_prev, orig_dev);
+		pt_prev = ptype;
+	}
+
+	list_for_each_entry_rcu(ptype, &skb->dev->ptype_all, list) {
+		if (pt_prev)
+			ret = deliver_skb(skb, pt_prev, orig_dev);
+		pt_prev = ptype;
+	}
+
+skip_taps:
+#ifdef CONFIG_NET_INGRESS
+	if (static_branch_unlikely(&ingress_needed_key)) {
+		bool another = false;
+
+		skb = sch_handle_ingress(skb, &pt_prev, &ret, orig_dev,
+					 &another);
+		if (another)
+			goto another_round;
+		if (!skb)
+			goto out;
+
+		if (nf_ingress(skb, &pt_prev, &ret, orig_dev) < 0)
+			goto out;
+	}
+#endif
+	skb_reset_redirect(skb);
+skip_classify:
+	if (pfmemalloc && !skb_pfmemalloc_protocol(skb))
+		goto drop;
+
+	if (skb_vlan_tag_present(skb)) {
+		if (pt_prev) {
+			ret = deliver_skb(skb, pt_prev, orig_dev);
+			pt_prev = NULL;
+		}
+		if (vlan_do_receive(&skb))
+			goto another_round;
+		else if (unlikely(!skb))
+			goto out;
+	}
+
+	rx_handler = rcu_dereference(skb->dev->rx_handler);
+	if (rx_handler) {
+		if (pt_prev) {
+			ret = deliver_skb(skb, pt_prev, orig_dev);
+			pt_prev = NULL;
+		}
+		switch (rx_handler(&skb)) {
+		case RX_HANDLER_CONSUMED:
+			ret = NET_RX_SUCCESS;
+			goto out;
+		case RX_HANDLER_ANOTHER:
+			goto another_round;
+		case RX_HANDLER_EXACT:
+			deliver_exact = true;
+		case RX_HANDLER_PASS:
+			break;
+		default:
+			BUG();
+		}
+	}
+
+	if (unlikely(skb_vlan_tag_present(skb)) && !netdev_uses_dsa(skb->dev)) {
+check_vlan_id:
+		if (skb_vlan_tag_get_id(skb)) {
+			/* Vlan id is non 0 and vlan_do_receive() above couldn't
+			 * find vlan device.
+			 */
+			skb->pkt_type = PACKET_OTHERHOST;
+		} else if (skb->protocol == cpu_to_be16(ETH_P_8021Q) ||
+			   skb->protocol == cpu_to_be16(ETH_P_8021AD)) {
+			/* Outer header is 802.1P with vlan 0, inner header is
+			 * 802.1Q or 802.1AD and vlan_do_receive() above could
+			 * not find vlan dev for vlan id 0.
+			 */
+			__vlan_hwaccel_clear_tag(skb);
+			skb = skb_vlan_untag(skb);
+			if (unlikely(!skb))
+				goto out;
+			if (vlan_do_receive(&skb))
+				/* After stripping off 802.1P header with vlan 0
+				 * vlan dev is found for inner header.
+				 */
+				goto another_round;
+			else if (unlikely(!skb))
+				goto out;
+			else
+				/* We have stripped outer 802.1P vlan 0 header.
+				 * But could not find vlan dev.
+				 * check again for vlan id to set OTHERHOST.
+				 */
+				goto check_vlan_id;
+		}
+		/* Note: we might in the future use prio bits
+		 * and set skb->priority like in vlan_do_receive()
+		 * For the time being, just ignore Priority Code Point
+		 */
+		__vlan_hwaccel_clear_tag(skb);
+	}
+
+	type = skb->protocol;
+
+	/* deliver only exact match when indicated */
+	if (likely(!deliver_exact)) {
+		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
+				       &ptype_base[ntohs(type) &
+						   PTYPE_HASH_MASK]);
+	}
+
+	deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
+			       &orig_dev->ptype_specific);
+
+	if (unlikely(skb->dev != orig_dev)) {
+		deliver_ptype_list_skb(skb, &pt_prev, orig_dev, type,
+				       &skb->dev->ptype_specific);
+	}
+
+	if (pt_prev) {
+		if (unlikely(skb_orphan_frags_rx(skb, GFP_ATOMIC)))
+			goto drop;
+		*ppt_prev = pt_prev;
+	} else {
+drop:
+		if (!deliver_exact)
+			atomic_long_inc(&skb->dev->rx_dropped);
+		else
+			atomic_long_inc(&skb->dev->rx_nohandler);
+		kfree_skb(skb);
+		/* Jamal, now you will not able to escape explaining
+		 * me how you were going to use this. :-)
+		 */
+		ret = NET_RX_DROP;
+	}
+
+out:
+	/* The invariant here is that if *ppt_prev is not NULL
+	 * then skb should also be non-NULL.
+	 *
+	 * Apparently *ppt_prev assignment above holds this invariant due to
+	 * skb dereferencing near it.
+	 */
+	*pskb = skb;
+	return ret;
+}
+
+static int __netif_receive_skb_one_core(struct sk_buff *skb, bool pfmemalloc)
+{
+	struct net_device *orig_dev = skb->dev;
+	struct packet_type *pt_prev = NULL;
+	int ret;
+
+	ret = __netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
+	if (pt_prev)
+		ret = INDIRECT_CALL_INET(pt_prev->func, ipv6_rcv, ip_rcv, skb,
+					 skb->dev, pt_prev, orig_dev);
+	return ret;
+}
+
+/**
+ *	netif_receive_skb_core - special purpose version of netif_receive_skb
+ *	@skb: buffer to process
+ *
+ *	More direct receive version of netif_receive_skb().  It should
+ *	only be used by callers that have a need to skip RPS and Generic XDP.
+ *	Caller must also take care of handling if ``(page_is_)pfmemalloc``.
+ *
+ *	This function may only be called from softirq context and interrupts
+ *	should be enabled.
+ *
+ *	Return values (usually ignored):
+ *	NET_RX_SUCCESS: no congestion
+ *	NET_RX_DROP: packet was dropped
+ */
+int netif_receive_skb_core(struct sk_buff *skb)
+{
+	int ret;
+
+	rcu_read_lock();
+	ret = __netif_receive_skb_one_core(skb, false);
+	rcu_read_unlock();
+
+	return ret;
+}
+EXPORT_SYMBOL(netif_receive_skb_core);
+
+static inline void __netif_receive_skb_list_ptype(struct list_head *head,
+						  struct packet_type *pt_prev,
+						  struct net_device *orig_dev)
+{
+	struct sk_buff *skb, *next;
+
+	if (!pt_prev)
+		return;
+	if (list_empty(head))
+		return;
+	if (pt_prev->list_func != NULL)
+		INDIRECT_CALL_INET(pt_prev->list_func, ipv6_list_rcv,
+				   ip_list_rcv, head, pt_prev, orig_dev);
+	else
+		list_for_each_entry_safe(skb, next, head, list) {
+			skb_list_del_init(skb);
+			pt_prev->func(skb, skb->dev, pt_prev, orig_dev);
+		}
+}
+
+static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
+{
+	/* Fast-path assumptions:
+	 * - There is no RX handler.
+	 * - Only one packet_type matches.
+	 * If either of these fails, we will end up doing some per-packet
+	 * processing in-line, then handling the 'last ptype' for the whole
+	 * sublist.  This can't cause out-of-order delivery to any single ptype,
+	 * because the 'last ptype' must be constant across the sublist, and all
+	 * other ptypes are handled per-packet.
+	 */
+	/* Current (common) ptype of sublist */
+	struct packet_type *pt_curr = NULL;
+	/* Current (common) orig_dev of sublist */
+	struct net_device *od_curr = NULL;
+	struct list_head sublist;
+	struct sk_buff *skb, *next;
+
+	INIT_LIST_HEAD(&sublist);
+	list_for_each_entry_safe(skb, next, head, list) {
+		struct net_device *orig_dev = skb->dev;
+		struct packet_type *pt_prev = NULL;
+
+		skb_list_del_init(skb);
+		__netif_receive_skb_core(&skb, pfmemalloc, &pt_prev);
+		if (!pt_prev)
+			continue;
+		if (pt_curr != pt_prev || od_curr != orig_dev) {
+			/* dispatch old sublist */
+			__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
+			/* start new sublist */
+			INIT_LIST_HEAD(&sublist);
+			pt_curr = pt_prev;
+			od_curr = orig_dev;
+		}
+		list_add_tail(&skb->list, &sublist);
+	}
+
+	/* dispatch final sublist */
+	__netif_receive_skb_list_ptype(&sublist, pt_curr, od_curr);
+}
+
+static int __netif_receive_skb(struct sk_buff *skb)
+{
+	int ret;
+
+	if (sk_memalloc_socks() && skb_pfmemalloc(skb)) {
+		unsigned int noreclaim_flag;
+
+		/*
+		 * PFMEMALLOC skbs are special, they should
+		 * - be delivered to SOCK_MEMALLOC sockets only
+		 * - stay away from userspace
+		 * - have bounded memory usage
+		 *
+		 * Use PF_MEMALLOC as this saves us from propagating the allocation
+		 * context down to all allocation sites.
+		 */
+		noreclaim_flag = memalloc_noreclaim_save();
+		ret = __netif_receive_skb_one_core(skb, true);
+		memalloc_noreclaim_restore(noreclaim_flag);
+	} else
+		ret = __netif_receive_skb_one_core(skb, false);
+
+	return ret;
+}
+
+static void __netif_receive_skb_list(struct list_head *head)
+{
+	unsigned long noreclaim_flag = 0;
+	struct sk_buff *skb, *next;
+	bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
+
+	list_for_each_entry_safe(skb, next, head, list) {
+		if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
+			struct list_head sublist;
+
+			/* Handle the previous sublist */
+			list_cut_before(&sublist, head, &skb->list);
+			if (!list_empty(&sublist))
+				__netif_receive_skb_list_core(&sublist, pfmemalloc);
+			pfmemalloc = !pfmemalloc;
+			/* See comments in __netif_receive_skb */
+			if (pfmemalloc)
+				noreclaim_flag = memalloc_noreclaim_save();
+			else
+				memalloc_noreclaim_restore(noreclaim_flag);
+		}
+	}
+	/* Handle the remaining sublist */
+	if (!list_empty(head))
+		__netif_receive_skb_list_core(head, pfmemalloc);
+	/* Restore pflags */
+	if (pfmemalloc)
+		memalloc_noreclaim_restore(noreclaim_flag);
+}
+
+static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
+{
+	struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
+	struct bpf_prog *new = xdp->prog;
+	int ret = 0;
+
+	if (new) {
+		u32 i;
+
+		mutex_lock(&new->aux->used_maps_mutex);
+
+		/* generic XDP does not work with DEVMAPs that can
+		 * have a bpf_prog installed on an entry
+		 */
+		for (i = 0; i < new->aux->used_map_cnt; i++) {
+			if (dev_map_can_have_prog(new->aux->used_maps[i]) ||
+			    cpu_map_prog_allowed(new->aux->used_maps[i])) {
+				mutex_unlock(&new->aux->used_maps_mutex);
+				return -EINVAL;
+			}
+		}
+
+		mutex_unlock(&new->aux->used_maps_mutex);
+	}
+
+	switch (xdp->command) {
+	case XDP_SETUP_PROG:
+		rcu_assign_pointer(dev->xdp_prog, new);
+		if (old)
+			bpf_prog_put(old);
+
+		if (old && !new) {
+			static_branch_dec(&generic_xdp_needed_key);
+		} else if (new && !old) {
+			static_branch_inc(&generic_xdp_needed_key);
+			dev_disable_lro(dev);
+			dev_disable_gro_hw(dev);
+		}
+		break;
+
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int netif_receive_skb_internal(struct sk_buff *skb)
+{
+	int ret;
+
+	net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
+
+	if (skb_defer_rx_timestamp(skb))
+		return NET_RX_SUCCESS;
+
+	rcu_read_lock();
+#ifdef CONFIG_RPS
+	if (static_branch_unlikely(&rps_needed)) {
+		struct rps_dev_flow voidflow, *rflow = &voidflow;
+		int cpu = get_rps_cpu(skb->dev, skb, &rflow);
+
+		if (cpu >= 0) {
+			ret = enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
+			rcu_read_unlock();
+			return ret;
+		}
+	}
+#endif
+	ret = __netif_receive_skb(skb);
+	rcu_read_unlock();
+	return ret;
+}
+
+static void netif_receive_skb_list_internal(struct list_head *head)
+{
+	struct sk_buff *skb, *next;
+	struct list_head sublist;
+
+	INIT_LIST_HEAD(&sublist);
+	list_for_each_entry_safe(skb, next, head, list) {
+		net_timestamp_check(READ_ONCE(netdev_tstamp_prequeue), skb);
+		skb_list_del_init(skb);
+		if (!skb_defer_rx_timestamp(skb))
+			list_add_tail(&skb->list, &sublist);
+	}
+	list_splice_init(&sublist, head);
+
+	rcu_read_lock();
+#ifdef CONFIG_RPS
+	if (static_branch_unlikely(&rps_needed)) {
+		list_for_each_entry_safe(skb, next, head, list) {
+			struct rps_dev_flow voidflow, *rflow = &voidflow;
+			int cpu = get_rps_cpu(skb->dev, skb, &rflow);
+
+			if (cpu >= 0) {
+				/* Will be handled, remove from list */
+				skb_list_del_init(skb);
+				enqueue_to_backlog(skb, cpu, &rflow->last_qtail);
+			}
+		}
+	}
+#endif
+	__netif_receive_skb_list(head);
+	rcu_read_unlock();
+}
+
+/**
+ *	netif_receive_skb - process receive buffer from network
+ *	@skb: buffer to process
+ *
+ *	netif_receive_skb() is the main receive data processing function.
+ *	It always succeeds. The buffer may be dropped during processing
+ *	for congestion control or by the protocol layers.
+ *
+ *	This function may only be called from softirq context and interrupts
+ *	should be enabled.
+ *
+ *	Return values (usually ignored):
+ *	NET_RX_SUCCESS: no congestion
+ *	NET_RX_DROP: packet was dropped
+ */
+int netif_receive_skb(struct sk_buff *skb)
+{
+	int ret;
+
+	trace_netif_receive_skb_entry(skb);
+
+	ret = netif_receive_skb_internal(skb);
+	trace_netif_receive_skb_exit(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(netif_receive_skb);
+
+/**
+ *	netif_receive_skb_list - process many receive buffers from network
+ *	@head: list of skbs to process.
+ *
+ *	Since return value of netif_receive_skb() is normally ignored, and
+ *	wouldn't be meaningful for a list, this function returns void.
+ *
+ *	This function may only be called from softirq context and interrupts
+ *	should be enabled.
+ */
+void netif_receive_skb_list(struct list_head *head)
+{
+	struct sk_buff *skb;
+
+	if (list_empty(head))
+		return;
+	if (trace_netif_receive_skb_list_entry_enabled()) {
+		list_for_each_entry(skb, head, list)
+			trace_netif_receive_skb_list_entry(skb);
+	}
+	netif_receive_skb_list_internal(head);
+	trace_netif_receive_skb_list_exit(0);
+}
+EXPORT_SYMBOL(netif_receive_skb_list);
+
+static DEFINE_PER_CPU(struct work_struct, flush_works);
+
+/* Network device is going away, flush any packets still pending */
+static void flush_backlog(struct work_struct *work)
+{
+	struct sk_buff *skb, *tmp;
+	struct softnet_data *sd;
+
+	local_bh_disable();
+	sd = this_cpu_ptr(&softnet_data);
+
+	local_irq_disable();
+	rps_lock(sd);
+	skb_queue_walk_safe(&sd->input_pkt_queue, skb, tmp) {
+		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
+			__skb_unlink(skb, &sd->input_pkt_queue);
+			dev_kfree_skb_irq(skb);
+			input_queue_head_incr(sd);
+		}
+	}
+	rps_unlock(sd);
+	local_irq_enable();
+
+	skb_queue_walk_safe(&sd->process_queue, skb, tmp) {
+		if (skb->dev->reg_state == NETREG_UNREGISTERING) {
+			__skb_unlink(skb, &sd->process_queue);
+			kfree_skb(skb);
+			input_queue_head_incr(sd);
+		}
+	}
+	local_bh_enable();
+}
+
+static bool flush_required(int cpu)
+{
+#if IS_ENABLED(CONFIG_RPS)
+	struct softnet_data *sd = &per_cpu(softnet_data, cpu);
+	bool do_flush;
+
+	local_irq_disable();
+	rps_lock(sd);
+
+	/* as insertion into process_queue happens with the rps lock held,
+	 * process_queue access may race only with dequeue
+	 */
+	do_flush = !skb_queue_empty(&sd->input_pkt_queue) ||
+		   !skb_queue_empty_lockless(&sd->process_queue);
+	rps_unlock(sd);
+	local_irq_enable();
+
+	return do_flush;
+#endif
+	/* without RPS we can't safely check input_pkt_queue: during a
+	 * concurrent remote skb_queue_splice() we can detect as empty both
+	 * input_pkt_queue and process_queue even if the latter could end-up
+	 * containing a lot of packets.
+	 */
+	return true;
+}
+
+static void flush_all_backlogs(void)
+{
+	static cpumask_t flush_cpus;
+	unsigned int cpu;
+
+	/* since we are under rtnl lock protection we can use static data
+	 * for the cpumask and avoid allocating on stack the possibly
+	 * large mask
+	 */
+	ASSERT_RTNL();
+
+	get_online_cpus();
+
+	cpumask_clear(&flush_cpus);
+	for_each_online_cpu(cpu) {
+		if (flush_required(cpu)) {
+			queue_work_on(cpu, system_highpri_wq,
+				      per_cpu_ptr(&flush_works, cpu));
+			cpumask_set_cpu(cpu, &flush_cpus);
+		}
+	}
+
+	/* we can have in flight packet[s] on the cpus we are not flushing,
+	 * synchronize_net() in unregister_netdevice_many() will take care of
+	 * them
+	 */
+	for_each_cpu(cpu, &flush_cpus)
+		flush_work(per_cpu_ptr(&flush_works, cpu));
+
+	put_online_cpus();
+}
+
+/* Pass the currently batched GRO_NORMAL SKBs up to the stack. */
+static void gro_normal_list(struct napi_struct *napi)
+{
+	if (!napi->rx_count)
+		return;
+	netif_receive_skb_list_internal(&napi->rx_list);
+	INIT_LIST_HEAD(&napi->rx_list);
+	napi->rx_count = 0;
+}
+
+/* Queue one GRO_NORMAL SKB up for list processing. If batch size exceeded,
+ * pass the whole batch up to the stack.
+ */
+static void gro_normal_one(struct napi_struct *napi, struct sk_buff *skb, int segs)
+{
+	list_add_tail(&skb->list, &napi->rx_list);
+	napi->rx_count += segs;
+	if (napi->rx_count >= gro_normal_batch)
+		gro_normal_list(napi);
+}
+
+INDIRECT_CALLABLE_DECLARE(int inet_gro_complete(struct sk_buff *, int));
+INDIRECT_CALLABLE_DECLARE(int ipv6_gro_complete(struct sk_buff *, int));
+static int napi_gro_complete(struct napi_struct *napi, struct sk_buff *skb)
+{
+	struct packet_offload *ptype;
+	__be16 type = skb->protocol;
+	struct list_head *head = &offload_base;
+	int err = -ENOENT;
+
+	BUILD_BUG_ON(sizeof(struct napi_gro_cb) > sizeof(skb->cb));
+
+	if (NAPI_GRO_CB(skb)->count == 1) {
+		skb_shinfo(skb)->gso_size = 0;
+		goto out;
+	}
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ptype, head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_complete)
+			continue;
+
+		err = INDIRECT_CALL_INET(ptype->callbacks.gro_complete,
+					 ipv6_gro_complete, inet_gro_complete,
+					 skb, 0);
+		break;
+	}
+	rcu_read_unlock();
+
+	if (err) {
+		WARN_ON(&ptype->list == head);
+		kfree_skb(skb);
+		return NET_RX_SUCCESS;
+	}
+
+out:
+	gro_normal_one(napi, skb, NAPI_GRO_CB(skb)->count);
+	return NET_RX_SUCCESS;
+}
+
+static void __napi_gro_flush_chain(struct napi_struct *napi, u32 index,
+				   bool flush_old)
+{
+	struct list_head *head = &napi->gro_hash[index].list;
+	struct sk_buff *skb, *p;
+
+	list_for_each_entry_safe_reverse(skb, p, head, list) {
+		if (flush_old && NAPI_GRO_CB(skb)->age == jiffies)
+			return;
+		skb_list_del_init(skb);
+		napi_gro_complete(napi, skb);
+		napi->gro_hash[index].count--;
+	}
+
+	if (!napi->gro_hash[index].count)
+		__clear_bit(index, &napi->gro_bitmask);
+}
+
+/* napi->gro_hash[].list contains packets ordered by age.
+ * youngest packets at the head of it.
+ * Complete skbs in reverse order to reduce latencies.
+ */
+void napi_gro_flush(struct napi_struct *napi, bool flush_old)
+{
+	unsigned long bitmask = napi->gro_bitmask;
+	unsigned int i, base = ~0U;
+
+	while ((i = ffs(bitmask)) != 0) {
+		bitmask >>= i;
+		base += i;
+		__napi_gro_flush_chain(napi, base, flush_old);
+	}
+}
+EXPORT_SYMBOL(napi_gro_flush);
+
+static struct list_head *gro_list_prepare(struct napi_struct *napi,
+					  struct sk_buff *skb)
+{
+	unsigned int maclen = skb->dev->hard_header_len;
+	u32 hash = skb_get_hash_raw(skb);
+	struct list_head *head;
+	struct sk_buff *p;
+
+	head = &napi->gro_hash[hash & (GRO_HASH_BUCKETS - 1)].list;
+	list_for_each_entry(p, head, list) {
+		unsigned long diffs;
+
+		NAPI_GRO_CB(p)->flush = 0;
+
+		if (hash != skb_get_hash_raw(p)) {
+			NAPI_GRO_CB(p)->same_flow = 0;
+			continue;
+		}
+
+		diffs = (unsigned long)p->dev ^ (unsigned long)skb->dev;
+		diffs |= skb_vlan_tag_present(p) ^ skb_vlan_tag_present(skb);
+		if (skb_vlan_tag_present(p))
+			diffs |= skb_vlan_tag_get(p) ^ skb_vlan_tag_get(skb);
+		diffs |= skb_metadata_dst_cmp(p, skb);
+		diffs |= skb_metadata_differs(p, skb);
+		if (maclen == ETH_HLEN)
+			diffs |= compare_ether_header(skb_mac_header(p),
+						      skb_mac_header(skb));
+		else if (!diffs)
+			diffs = memcmp(skb_mac_header(p),
+				       skb_mac_header(skb),
+				       maclen);
+
+		diffs |= skb_get_nfct(p) ^ skb_get_nfct(skb);
+#if IS_ENABLED(CONFIG_SKB_EXTENSIONS) && IS_ENABLED(CONFIG_NET_TC_SKB_EXT)
+		if (!diffs) {
+			struct tc_skb_ext *skb_ext = skb_ext_find(skb, TC_SKB_EXT);
+			struct tc_skb_ext *p_ext = skb_ext_find(p, TC_SKB_EXT);
+
+			diffs |= (!!p_ext) ^ (!!skb_ext);
+			if (!diffs && unlikely(skb_ext))
+				diffs |= p_ext->chain ^ skb_ext->chain;
+		}
+#endif
+
+		NAPI_GRO_CB(p)->same_flow = !diffs;
+	}
+
+	return head;
+}
+
+static inline void skb_gro_reset_offset(struct sk_buff *skb, u32 nhoff)
+{
+	const struct skb_shared_info *pinfo = skb_shinfo(skb);
+	const skb_frag_t *frag0 = &pinfo->frags[0];
+
+	NAPI_GRO_CB(skb)->data_offset = 0;
+	NAPI_GRO_CB(skb)->frag0 = NULL;
+	NAPI_GRO_CB(skb)->frag0_len = 0;
+
+	if (!skb_headlen(skb) && pinfo->nr_frags &&
+	    !PageHighMem(skb_frag_page(frag0)) &&
+	    (!NET_IP_ALIGN || !((skb_frag_off(frag0) + nhoff) & 3))) {
+		NAPI_GRO_CB(skb)->frag0 = skb_frag_address(frag0);
+		NAPI_GRO_CB(skb)->frag0_len = min_t(unsigned int,
+						    skb_frag_size(frag0),
+						    skb->end - skb->tail);
+	}
+}
+
+static void gro_pull_from_frag0(struct sk_buff *skb, int grow)
+{
+	struct skb_shared_info *pinfo = skb_shinfo(skb);
+
+	BUG_ON(skb->end - skb->tail < grow);
+
+	memcpy(skb_tail_pointer(skb), NAPI_GRO_CB(skb)->frag0, grow);
+
+	skb->data_len -= grow;
+	skb->tail += grow;
+
+	skb_frag_off_add(&pinfo->frags[0], grow);
+	skb_frag_size_sub(&pinfo->frags[0], grow);
+
+	if (unlikely(!skb_frag_size(&pinfo->frags[0]))) {
+		skb_frag_unref(skb, 0);
+		memmove(pinfo->frags, pinfo->frags + 1,
+			--pinfo->nr_frags * sizeof(pinfo->frags[0]));
+	}
+}
+
+static void gro_flush_oldest(struct napi_struct *napi, struct list_head *head)
+{
+	struct sk_buff *oldest;
+
+	oldest = list_last_entry(head, struct sk_buff, list);
+
+	/* We are called with head length >= MAX_GRO_SKBS, so this is
+	 * impossible.
+	 */
+	if (WARN_ON_ONCE(!oldest))
+		return;
+
+	/* Do not adjust napi->gro_hash[].count, caller is adding a new
+	 * SKB to the chain.
+	 */
+	skb_list_del_init(oldest);
+	napi_gro_complete(napi, oldest);
+}
+
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *inet_gro_receive(struct list_head *,
+							   struct sk_buff *));
+INDIRECT_CALLABLE_DECLARE(struct sk_buff *ipv6_gro_receive(struct list_head *,
+							   struct sk_buff *));
+static enum gro_result dev_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
+{
+	u32 hash = skb_get_hash_raw(skb) & (GRO_HASH_BUCKETS - 1);
+	struct list_head *head = &offload_base;
+	struct packet_offload *ptype;
+	__be16 type = skb->protocol;
+	struct list_head *gro_head;
+	struct sk_buff *pp = NULL;
+	enum gro_result ret;
+	int same_flow;
+	int grow;
+
+	if (netif_elide_gro(skb->dev))
+		goto normal;
+
+	gro_head = gro_list_prepare(napi, skb);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(ptype, head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_receive)
+			continue;
+
+		skb_set_network_header(skb, skb_gro_offset(skb));
+		skb_reset_mac_len(skb);
+		NAPI_GRO_CB(skb)->same_flow = 0;
+		NAPI_GRO_CB(skb)->flush = skb_is_gso(skb) || skb_has_frag_list(skb);
+		NAPI_GRO_CB(skb)->free = 0;
+		NAPI_GRO_CB(skb)->encap_mark = 0;
+		NAPI_GRO_CB(skb)->recursion_counter = 0;
+		NAPI_GRO_CB(skb)->is_fou = 0;
+		NAPI_GRO_CB(skb)->is_atomic = 1;
+		NAPI_GRO_CB(skb)->gro_remcsum_start = 0;
+
+		/* Setup for GRO checksum validation */
+		switch (skb->ip_summed) {
+		case CHECKSUM_COMPLETE:
+			NAPI_GRO_CB(skb)->csum = skb->csum;
+			NAPI_GRO_CB(skb)->csum_valid = 1;
+			NAPI_GRO_CB(skb)->csum_cnt = 0;
+			break;
+		case CHECKSUM_UNNECESSARY:
+			NAPI_GRO_CB(skb)->csum_cnt = skb->csum_level + 1;
+			NAPI_GRO_CB(skb)->csum_valid = 0;
+			break;
+		default:
+			NAPI_GRO_CB(skb)->csum_cnt = 0;
+			NAPI_GRO_CB(skb)->csum_valid = 0;
+		}
+
+		pp = INDIRECT_CALL_INET(ptype->callbacks.gro_receive,
+					ipv6_gro_receive, inet_gro_receive,
+					gro_head, skb);
+		break;
+	}
+	rcu_read_unlock();
+
+	if (&ptype->list == head)
+		goto normal;
+
+	if (PTR_ERR(pp) == -EINPROGRESS) {
+		ret = GRO_CONSUMED;
+		goto ok;
+	}
+
+	same_flow = NAPI_GRO_CB(skb)->same_flow;
+	ret = NAPI_GRO_CB(skb)->free ? GRO_MERGED_FREE : GRO_MERGED;
+
+	if (pp) {
+		skb_list_del_init(pp);
+		napi_gro_complete(napi, pp);
+		napi->gro_hash[hash].count--;
+	}
+
+	if (same_flow)
+		goto ok;
+
+	if (NAPI_GRO_CB(skb)->flush)
+		goto normal;
+
+	if (unlikely(napi->gro_hash[hash].count >= MAX_GRO_SKBS)) {
+		gro_flush_oldest(napi, gro_head);
+	} else {
+		napi->gro_hash[hash].count++;
+	}
+	NAPI_GRO_CB(skb)->count = 1;
+	NAPI_GRO_CB(skb)->age = jiffies;
+	NAPI_GRO_CB(skb)->last = skb;
+	skb_shinfo(skb)->gso_size = skb_gro_len(skb);
+	list_add(&skb->list, gro_head);
+	ret = GRO_HELD;
+
+pull:
+	grow = skb_gro_offset(skb) - skb_headlen(skb);
+	if (grow > 0)
+		gro_pull_from_frag0(skb, grow);
+ok:
+	if (napi->gro_hash[hash].count) {
+		if (!test_bit(hash, &napi->gro_bitmask))
+			__set_bit(hash, &napi->gro_bitmask);
+	} else if (test_bit(hash, &napi->gro_bitmask)) {
+		__clear_bit(hash, &napi->gro_bitmask);
+	}
+
+	return ret;
+
+normal:
+	ret = GRO_NORMAL;
+	goto pull;
+}
+
+struct packet_offload *gro_find_receive_by_type(__be16 type)
+{
+	struct list_head *offload_head = &offload_base;
+	struct packet_offload *ptype;
+
+	list_for_each_entry_rcu(ptype, offload_head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_receive)
+			continue;
+		return ptype;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(gro_find_receive_by_type);
+
+struct packet_offload *gro_find_complete_by_type(__be16 type)
+{
+	struct list_head *offload_head = &offload_base;
+	struct packet_offload *ptype;
+
+	list_for_each_entry_rcu(ptype, offload_head, list) {
+		if (ptype->type != type || !ptype->callbacks.gro_complete)
+			continue;
+		return ptype;
+	}
+	return NULL;
+}
+EXPORT_SYMBOL(gro_find_complete_by_type);
+
+static void napi_skb_free_stolen_head(struct sk_buff *skb)
+{
+	nf_reset_ct(skb);
+	skb_dst_drop(skb);
+	skb_ext_put(skb);
+	kmem_cache_free(skbuff_head_cache, skb);
+}
+
+static gro_result_t napi_skb_finish(struct napi_struct *napi,
+				    struct sk_buff *skb,
+				    gro_result_t ret)
+{
+	switch (ret) {
+	case GRO_NORMAL:
+		gro_normal_one(napi, skb, 1);
+		break;
+
+	case GRO_DROP:
+		kfree_skb(skb);
+		break;
+
+	case GRO_MERGED_FREE:
+		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
+			napi_skb_free_stolen_head(skb);
+		else
+			__kfree_skb(skb);
+		break;
+
+	case GRO_HELD:
+	case GRO_MERGED:
+	case GRO_CONSUMED:
+		break;
+	}
+
+	return ret;
+}
+
+gro_result_t napi_gro_receive(struct napi_struct *napi, struct sk_buff *skb)
+{
+	gro_result_t ret;
+
+	skb_mark_napi_id(skb, napi);
+	trace_napi_gro_receive_entry(skb);
+
+	skb_gro_reset_offset(skb, 0);
+
+	ret = napi_skb_finish(napi, skb, dev_gro_receive(napi, skb));
+	trace_napi_gro_receive_exit(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(napi_gro_receive);
+
+static void napi_reuse_skb(struct napi_struct *napi, struct sk_buff *skb)
+{
+	if (unlikely(skb->pfmemalloc)) {
+		consume_skb(skb);
+		return;
+	}
+	__skb_pull(skb, skb_headlen(skb));
+	/* restore the reserve we had after netdev_alloc_skb_ip_align() */
+	skb_reserve(skb, NET_SKB_PAD + NET_IP_ALIGN - skb_headroom(skb));
+	__vlan_hwaccel_clear_tag(skb);
+	skb->dev = napi->dev;
+	skb->skb_iif = 0;
+
+	/* eth_type_trans() assumes pkt_type is PACKET_HOST */
+	skb->pkt_type = PACKET_HOST;
+
+	skb->encapsulation = 0;
+	skb_shinfo(skb)->gso_type = 0;
+	skb->truesize = SKB_TRUESIZE(skb_end_offset(skb));
+	skb_ext_reset(skb);
+	nf_reset_ct(skb);
+
+	napi->skb = skb;
+}
+
+struct sk_buff *napi_get_frags(struct napi_struct *napi)
+{
+	struct sk_buff *skb = napi->skb;
+
+	if (!skb) {
+		skb = napi_alloc_skb(napi, GRO_MAX_HEAD);
+		if (skb) {
+			napi->skb = skb;
+			skb_mark_napi_id(skb, napi);
+		}
+	}
+	return skb;
+}
+EXPORT_SYMBOL(napi_get_frags);
+
+static gro_result_t napi_frags_finish(struct napi_struct *napi,
+				      struct sk_buff *skb,
+				      gro_result_t ret)
+{
+	switch (ret) {
+	case GRO_NORMAL:
+	case GRO_HELD:
+		__skb_push(skb, ETH_HLEN);
+		skb->protocol = eth_type_trans(skb, skb->dev);
+		if (ret == GRO_NORMAL)
+			gro_normal_one(napi, skb, 1);
+		break;
+
+	case GRO_DROP:
+		napi_reuse_skb(napi, skb);
+		break;
+
+	case GRO_MERGED_FREE:
+		if (NAPI_GRO_CB(skb)->free == NAPI_GRO_FREE_STOLEN_HEAD)
+			napi_skb_free_stolen_head(skb);
+		else
+			napi_reuse_skb(napi, skb);
+		break;
+
+	case GRO_MERGED:
+	case GRO_CONSUMED:
+		break;
+	}
+
+	return ret;
+}
+
+/* Upper GRO stack assumes network header starts at gro_offset=0
+ * Drivers could call both napi_gro_frags() and napi_gro_receive()
+ * We copy ethernet header into skb->data to have a common layout.
+ */
+static struct sk_buff *napi_frags_skb(struct napi_struct *napi)
+{
+	struct sk_buff *skb = napi->skb;
+	const struct ethhdr *eth;
+	unsigned int hlen = sizeof(*eth);
+
+	napi->skb = NULL;
+
+	skb_reset_mac_header(skb);
+	skb_gro_reset_offset(skb, hlen);
+
+	if (unlikely(skb_gro_header_hard(skb, hlen))) {
+		eth = skb_gro_header_slow(skb, hlen, 0);
+		if (unlikely(!eth)) {
+			net_warn_ratelimited("%s: dropping impossible skb from %s\n",
+					     __func__, napi->dev->name);
+			napi_reuse_skb(napi, skb);
+			return NULL;
+		}
+	} else {
+		eth = (const struct ethhdr *)skb->data;
+		gro_pull_from_frag0(skb, hlen);
+		NAPI_GRO_CB(skb)->frag0 += hlen;
+		NAPI_GRO_CB(skb)->frag0_len -= hlen;
+	}
+	__skb_pull(skb, hlen);
+
+	/*
+	 * This works because the only protocols we care about don't require
+	 * special handling.
+	 * We'll fix it up properly in napi_frags_finish()
+	 */
+	skb->protocol = eth->h_proto;
+
+	return skb;
+}
+
+gro_result_t napi_gro_frags(struct napi_struct *napi)
+{
+	gro_result_t ret;
+	struct sk_buff *skb = napi_frags_skb(napi);
+
+	if (!skb)
+		return GRO_DROP;
+
+	trace_napi_gro_frags_entry(skb);
+
+	ret = napi_frags_finish(napi, skb, dev_gro_receive(napi, skb));
+	trace_napi_gro_frags_exit(ret);
+
+	return ret;
+}
+EXPORT_SYMBOL(napi_gro_frags);
+
+/* Compute the checksum from gro_offset and return the folded value
+ * after adding in any pseudo checksum.
+ */
+__sum16 __skb_gro_checksum_complete(struct sk_buff *skb)
+{
+	__wsum wsum;
+	__sum16 sum;
+
+	wsum = skb_checksum(skb, skb_gro_offset(skb), skb_gro_len(skb), 0);
+
+	/* NAPI_GRO_CB(skb)->csum holds pseudo checksum */
+	sum = csum_fold(csum_add(NAPI_GRO_CB(skb)->csum, wsum));
+	/* See comments in __skb_checksum_complete(). */
+	if (likely(!sum)) {
+		if (unlikely(skb->ip_summed == CHECKSUM_COMPLETE) &&
+		    !skb->csum_complete_sw)
+			netdev_rx_csum_fault(skb->dev, skb);
+	}
+
+	NAPI_GRO_CB(skb)->csum = wsum;
+	NAPI_GRO_CB(skb)->csum_valid = 1;
+
+	return sum;
+}
+EXPORT_SYMBOL(__skb_gro_checksum_complete);
+
+static void net_rps_send_ipi(struct softnet_data *remsd)
+{
+#ifdef CONFIG_RPS
+	while (remsd) {
+		struct softnet_data *next = remsd->rps_ipi_next;
+
+		if (cpu_online(remsd->cpu))
+			smp_call_function_single_async(remsd->cpu, &remsd->csd);
+		remsd = next;
+	}
+#endif
+}
+
+/*
+ * net_rps_action_and_irq_enable sends any pending IPI's for rps.
+ * Note: called with local irq disabled, but exits with local irq enabled.
+ */
+static void net_rps_action_and_irq_enable(struct softnet_data *sd)
+{
+#ifdef CONFIG_RPS
+	struct softnet_data *remsd = sd->rps_ipi_list;
+
+	if (remsd) {
+		sd->rps_ipi_list = NULL;
+
+		local_irq_enable();
+
+		/* Send pending IPI's to kick RPS processing on remote cpus. */
+		net_rps_send_ipi(remsd);
+	} else
+#endif
+		local_irq_enable();
+}
+
+static bool sd_has_rps_ipi_waiting(struct softnet_data *sd)
+{
+#ifdef CONFIG_RPS
+	return sd->rps_ipi_list != NULL;
+#else
+	return false;
+#endif
+}
+
+static int process_backlog(struct napi_struct *napi, int quota)
+{
+	struct softnet_data *sd = container_of(napi, struct softnet_data, backlog);
+	bool again = true;
+	int work = 0;
+
+	/* Check if we have pending ipi, its better to send them now,
+	 * not waiting net_rx_action() end.
+	 */
+	if (sd_has_rps_ipi_waiting(sd)) {
+		local_irq_disable();
+		net_rps_action_and_irq_enable(sd);
+	}
+
+	napi->weight = READ_ONCE(dev_rx_weight);
+	while (again) {
+		struct sk_buff *skb;
+
+		while ((skb = __skb_dequeue(&sd->process_queue))) {
+			rcu_read_lock();
+			__netif_receive_skb(skb);
+			rcu_read_unlock();
+			input_queue_head_incr(sd);
+			if (++work >= quota)
+				return work;
+
+		}
+
+		local_irq_disable();
+		rps_lock(sd);
+		if (skb_queue_empty(&sd->input_pkt_queue)) {
+			/*
+			 * Inline a custom version of __napi_complete().
+			 * only current cpu owns and manipulates this napi,
+			 * and NAPI_STATE_SCHED is the only possible flag set
+			 * on backlog.
+			 * We can use a plain write instead of clear_bit(),
+			 * and we dont need an smp_mb() memory barrier.
+			 */
+			napi->state = 0;
+			again = false;
+		} else {
+			skb_queue_splice_tail_init(&sd->input_pkt_queue,
+						   &sd->process_queue);
+		}
+		rps_unlock(sd);
+		local_irq_enable();
+	}
+
+	return work;
+}
+
+/**
+ * __napi_schedule - schedule for receive
+ * @n: entry to schedule
+ *
+ * The entry's receive function will be scheduled to run.
+ * Consider using __napi_schedule_irqoff() if hard irqs are masked.
+ */
+void __napi_schedule(struct napi_struct *n)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	____napi_schedule(this_cpu_ptr(&softnet_data), n);
+	local_irq_restore(flags);
+}
+EXPORT_SYMBOL(__napi_schedule);
+
+/**
+ *	napi_schedule_prep - check if napi can be scheduled
+ *	@n: napi context
+ *
+ * Test if NAPI routine is already running, and if not mark
+ * it as running.  This is used as a condition variable to
+ * insure only one NAPI poll instance runs.  We also make
+ * sure there is no pending NAPI disable.
+ */
+bool napi_schedule_prep(struct napi_struct *n)
+{
+	unsigned long val, new;
+
+	do {
+		val = READ_ONCE(n->state);
+		if (unlikely(val & NAPIF_STATE_DISABLE))
+			return false;
+		new = val | NAPIF_STATE_SCHED;
+
+		/* Sets STATE_MISSED bit if STATE_SCHED was already set
+		 * This was suggested by Alexander Duyck, as compiler
+		 * emits better code than :
+		 * if (val & NAPIF_STATE_SCHED)
+		 *     new |= NAPIF_STATE_MISSED;
+		 */
+		new |= (val & NAPIF_STATE_SCHED) / NAPIF_STATE_SCHED *
+						   NAPIF_STATE_MISSED;
+	} while (cmpxchg(&n->state, val, new) != val);
+
+	return !(val & NAPIF_STATE_SCHED);
+}
+EXPORT_SYMBOL(napi_schedule_prep);
+
+/**
+ * __napi_schedule_irqoff - schedule for receive
+ * @n: entry to schedule
+ *
+ * Variant of __napi_schedule() assuming hard irqs are masked.
+ *
+ * On PREEMPT_RT enabled kernels this maps to __napi_schedule()
+ * because the interrupt disabled assumption might not be true
+ * due to force-threaded interrupts and spinlock substitution.
+ */
+void __napi_schedule_irqoff(struct napi_struct *n)
+{
+	if (!IS_ENABLED(CONFIG_PREEMPT_RT))
+		____napi_schedule(this_cpu_ptr(&softnet_data), n);
+	else
+		__napi_schedule(n);
+}
+EXPORT_SYMBOL(__napi_schedule_irqoff);
+
+bool napi_complete_done(struct napi_struct *n, int work_done)
+{
+	unsigned long flags, val, new, timeout = 0;
+	bool ret = true;
+
+	/*
+	 * 1) Don't let napi dequeue from the cpu poll list
+	 *    just in case its running on a different cpu.
+	 * 2) If we are busy polling, do nothing here, we have
+	 *    the guarantee we will be called later.
+	 */
+	if (unlikely(n->state & (NAPIF_STATE_NPSVC |
+				 NAPIF_STATE_IN_BUSY_POLL)))
+		return false;
+
+	if (work_done) {
+		if (n->gro_bitmask)
+			timeout = READ_ONCE(n->dev->gro_flush_timeout);
+		n->defer_hard_irqs_count = READ_ONCE(n->dev->napi_defer_hard_irqs);
+	}
+	if (n->defer_hard_irqs_count > 0) {
+		n->defer_hard_irqs_count--;
+		timeout = READ_ONCE(n->dev->gro_flush_timeout);
+		if (timeout)
+			ret = false;
+	}
+	if (n->gro_bitmask) {
+		/* When the NAPI instance uses a timeout and keeps postponing
+		 * it, we need to bound somehow the time packets are kept in
+		 * the GRO layer
+		 */
+		napi_gro_flush(n, !!timeout);
+	}
+
+	gro_normal_list(n);
+
+	if (unlikely(!list_empty(&n->poll_list))) {
+		/* If n->poll_list is not empty, we need to mask irqs */
+		local_irq_save(flags);
+		list_del_init(&n->poll_list);
+		local_irq_restore(flags);
+	}
+
+	do {
+		val = READ_ONCE(n->state);
+
+		WARN_ON_ONCE(!(val & NAPIF_STATE_SCHED));
+
+		new = val & ~(NAPIF_STATE_MISSED | NAPIF_STATE_SCHED);
+
+		/* If STATE_MISSED was set, leave STATE_SCHED set,
+		 * because we will call napi->poll() one more time.
+		 * This C code was suggested by Alexander Duyck to help gcc.
+		 */
+		new |= (val & NAPIF_STATE_MISSED) / NAPIF_STATE_MISSED *
+						    NAPIF_STATE_SCHED;
+	} while (cmpxchg(&n->state, val, new) != val);
+
+	if (unlikely(val & NAPIF_STATE_MISSED)) {
+		__napi_schedule(n);
+		return false;
+	}
+
+	if (timeout)
+		hrtimer_start(&n->timer, ns_to_ktime(timeout),
+			      HRTIMER_MODE_REL_PINNED);
+	return ret;
+}
+EXPORT_SYMBOL(napi_complete_done);
+
+/* must be called under rcu_read_lock(), as we dont take a reference */
+static struct napi_struct *napi_by_id(unsigned int napi_id)
+{
+	unsigned int hash = napi_id % HASH_SIZE(napi_hash);
+	struct napi_struct *napi;
+
+	hlist_for_each_entry_rcu(napi, &napi_hash[hash], napi_hash_node)
+		if (napi->napi_id == napi_id)
+			return napi;
+
+	return NULL;
+}
+
+#if defined(CONFIG_NET_RX_BUSY_POLL)
+
+#define BUSY_POLL_BUDGET 8
+
+static void busy_poll_stop(struct napi_struct *napi, void *have_poll_lock)
+{
+	int rc;
+
+	/* Busy polling means there is a high chance device driver hard irq
+	 * could not grab NAPI_STATE_SCHED, and that NAPI_STATE_MISSED was
+	 * set in napi_schedule_prep().
+	 * Since we are about to call napi->poll() once more, we can safely
+	 * clear NAPI_STATE_MISSED.
+	 *
+	 * Note: x86 could use a single "lock and ..." instruction
+	 * to perform these two clear_bit()
+	 */
+	clear_bit(NAPI_STATE_MISSED, &napi->state);
+	clear_bit(NAPI_STATE_IN_BUSY_POLL, &napi->state);
+
+	local_bh_disable();
+
+	/* All we really want here is to re-enable device interrupts.
+	 * Ideally, a new ndo_busy_poll_stop() could avoid another round.
+	 */
+	rc = napi->poll(napi, BUSY_POLL_BUDGET);
+	/* We can't gro_normal_list() here, because napi->poll() might have
+	 * rearmed the napi (napi_complete_done()) in which case it could
+	 * already be running on another CPU.
+	 */
+	trace_napi_poll(napi, rc, BUSY_POLL_BUDGET);
+	netpoll_poll_unlock(have_poll_lock);
+	if (rc == BUSY_POLL_BUDGET) {
+		/* As the whole budget was spent, we still own the napi so can
+		 * safely handle the rx_list.
+		 */
+		gro_normal_list(napi);
+		__napi_schedule(napi);
+	}
+	local_bh_enable();
+}
+
+void napi_busy_loop(unsigned int napi_id,
+		    bool (*loop_end)(void *, unsigned long),
+		    void *loop_end_arg)
+{
+	unsigned long start_time = loop_end ? busy_loop_current_time() : 0;
+	int (*napi_poll)(struct napi_struct *napi, int budget);
+	void *have_poll_lock = NULL;
+	struct napi_struct *napi;
+
+restart:
+	napi_poll = NULL;
+
+	rcu_read_lock();
+
+	napi = napi_by_id(napi_id);
+	if (!napi)
+		goto out;
+
+	preempt_disable();
+	for (;;) {
+		int work = 0;
+
+		local_bh_disable();
+		if (!napi_poll) {
+			unsigned long val = READ_ONCE(napi->state);
+
+			/* If multiple threads are competing for this napi,
+			 * we avoid dirtying napi->state as much as we can.
+			 */
+			if (val & (NAPIF_STATE_DISABLE | NAPIF_STATE_SCHED |
+				   NAPIF_STATE_IN_BUSY_POLL))
+				goto count;
+			if (cmpxchg(&napi->state, val,
+				    val | NAPIF_STATE_IN_BUSY_POLL |
+					  NAPIF_STATE_SCHED) != val)
+				goto count;
+			have_poll_lock = netpoll_poll_lock(napi);
+			napi_poll = napi->poll;
+		}
+		work = napi_poll(napi, BUSY_POLL_BUDGET);
+		trace_napi_poll(napi, work, BUSY_POLL_BUDGET);
+		gro_normal_list(napi);
+count:
+		if (work > 0)
+			__NET_ADD_STATS(dev_net(napi->dev),
+					LINUX_MIB_BUSYPOLLRXPACKETS, work);
+		local_bh_enable();
+
+		if (!loop_end || loop_end(loop_end_arg, start_time))
+			break;
+
+		if (unlikely(need_resched())) {
+			if (napi_poll)
+				busy_poll_stop(napi, have_poll_lock);
+			preempt_enable();
+			rcu_read_unlock();
+			cond_resched();
+			if (loop_end(loop_end_arg, start_time))
+				return;
+			goto restart;
+		}
+		cpu_relax();
+	}
+	if (napi_poll)
+		busy_poll_stop(napi, have_poll_lock);
+	preempt_enable();
+out:
+	rcu_read_unlock();
+}
+EXPORT_SYMBOL(napi_busy_loop);
+
+#endif /* CONFIG_NET_RX_BUSY_POLL */
+
+static void napi_hash_add(struct napi_struct *napi)
+{
+	if (test_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state))
+		return;
+
+	spin_lock(&napi_hash_lock);
+
+	/* 0..NR_CPUS range is reserved for sender_cpu use */
+	do {
+		if (unlikely(++napi_gen_id < MIN_NAPI_ID))
+			napi_gen_id = MIN_NAPI_ID;
+	} while (napi_by_id(napi_gen_id));
+	napi->napi_id = napi_gen_id;
+
+	hlist_add_head_rcu(&napi->napi_hash_node,
+			   &napi_hash[napi->napi_id % HASH_SIZE(napi_hash)]);
+
+	spin_unlock(&napi_hash_lock);
+}
+
+/* Warning : caller is responsible to make sure rcu grace period
+ * is respected before freeing memory containing @napi
+ */
+static void napi_hash_del(struct napi_struct *napi)
+{
+	spin_lock(&napi_hash_lock);
+
+	hlist_del_init_rcu(&napi->napi_hash_node);
+
+	spin_unlock(&napi_hash_lock);
+}
+
+static enum hrtimer_restart napi_watchdog(struct hrtimer *timer)
+{
+	struct napi_struct *napi;
+
+	napi = container_of(timer, struct napi_struct, timer);
+
+	/* Note : we use a relaxed variant of napi_schedule_prep() not setting
+	 * NAPI_STATE_MISSED, since we do not react to a device IRQ.
+	 */
+	if (!napi_disable_pending(napi) &&
+	    !test_and_set_bit(NAPI_STATE_SCHED, &napi->state))
+		__napi_schedule_irqoff(napi);
+
+	return HRTIMER_NORESTART;
+}
+
+static void init_gro_hash(struct napi_struct *napi)
+{
+	int i;
+
+	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
+		INIT_LIST_HEAD(&napi->gro_hash[i].list);
+		napi->gro_hash[i].count = 0;
+	}
+	napi->gro_bitmask = 0;
+}
+
+void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
+		    int (*poll)(struct napi_struct *, int), int weight)
+{
+	if (WARN_ON(test_and_set_bit(NAPI_STATE_LISTED, &napi->state)))
+		return;
+
+	INIT_LIST_HEAD(&napi->poll_list);
+	INIT_HLIST_NODE(&napi->napi_hash_node);
+	hrtimer_init(&napi->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_PINNED);
+	napi->timer.function = napi_watchdog;
+	init_gro_hash(napi);
+	napi->skb = NULL;
+	INIT_LIST_HEAD(&napi->rx_list);
+	napi->rx_count = 0;
+	napi->poll = poll;
+	if (weight > NAPI_POLL_WEIGHT)
+		netdev_err_once(dev, "%s() called with weight %d\n", __func__,
+				weight);
+	napi->weight = weight;
+	napi->dev = dev;
+#ifdef CONFIG_NETPOLL
+	napi->poll_owner = -1;
+#endif
+	set_bit(NAPI_STATE_SCHED, &napi->state);
+	set_bit(NAPI_STATE_NPSVC, &napi->state);
+	list_add_rcu(&napi->dev_list, &dev->napi_list);
+	napi_hash_add(napi);
+}
+EXPORT_SYMBOL(netif_napi_add);
+
+void napi_disable(struct napi_struct *n)
+{
+	might_sleep();
+	set_bit(NAPI_STATE_DISABLE, &n->state);
+
+	while (test_and_set_bit(NAPI_STATE_SCHED, &n->state))
+		msleep(1);
+	while (test_and_set_bit(NAPI_STATE_NPSVC, &n->state))
+		msleep(1);
+
+	hrtimer_cancel(&n->timer);
+
+	clear_bit(NAPI_STATE_DISABLE, &n->state);
+}
+EXPORT_SYMBOL(napi_disable);
+
+static void flush_gro_hash(struct napi_struct *napi)
+{
+	int i;
+
+	for (i = 0; i < GRO_HASH_BUCKETS; i++) {
+		struct sk_buff *skb, *n;
+
+		list_for_each_entry_safe(skb, n, &napi->gro_hash[i].list, list)
+			kfree_skb(skb);
+		napi->gro_hash[i].count = 0;
+	}
+}
+
+/* Must be called in process context */
+void __netif_napi_del(struct napi_struct *napi)
+{
+	if (!test_and_clear_bit(NAPI_STATE_LISTED, &napi->state))
+		return;
+
+	napi_hash_del(napi);
+	list_del_rcu(&napi->dev_list);
+	napi_free_frags(napi);
+
+	flush_gro_hash(napi);
+	napi->gro_bitmask = 0;
+}
+EXPORT_SYMBOL(__netif_napi_del);
+
+static int napi_poll(struct napi_struct *n, struct list_head *repoll)
+{
+	void *have;
+	int work, weight;
+
+	list_del_init(&n->poll_list);
+
+	have = netpoll_poll_lock(n);
+
+	weight = n->weight;
+
+	/* This NAPI_STATE_SCHED test is for avoiding a race
+	 * with netpoll's poll_napi().  Only the entity which
+	 * obtains the lock and sees NAPI_STATE_SCHED set will
+	 * actually make the ->poll() call.  Therefore we avoid
+	 * accidentally calling ->poll() when NAPI is not scheduled.
+	 */
+	work = 0;
+	if (test_bit(NAPI_STATE_SCHED, &n->state)) {
+		work = n->poll(n, weight);
+		trace_napi_poll(n, work, weight);
+	}
+
+	if (unlikely(work > weight))
+		pr_err_once("NAPI poll function %pS returned %d, exceeding its budget of %d.\n",
+			    n->poll, work, weight);
+
+	if (likely(work < weight))
+		goto out_unlock;
+
+	/* Drivers must not modify the NAPI state if they
+	 * consume the entire weight.  In such cases this code
+	 * still "owns" the NAPI instance and therefore can
+	 * move the instance around on the list at-will.
+	 */
+	if (unlikely(napi_disable_pending(n))) {
+		napi_complete(n);
+		goto out_unlock;
+	}
+
+	if (n->gro_bitmask) {
+		/* flush too old packets
+		 * If HZ < 1000, flush all packets.
+		 */
+		napi_gro_flush(n, HZ >= 1000);
+	}
+
+	gro_normal_list(n);
+
+	/* Some drivers may have called napi_schedule
+	 * prior to exhausting their budget.
+	 */
+	if (unlikely(!list_empty(&n->poll_list))) {
+		pr_warn_once("%s: Budget exhausted after napi rescheduled\n",
+			     n->dev ? n->dev->name : "backlog");
+		goto out_unlock;
+	}
+
+	list_add_tail(&n->poll_list, repoll);
+
+out_unlock:
+	netpoll_poll_unlock(have);
+
+	return work;
+}
+
+static __latent_entropy void net_rx_action(struct softirq_action *h)
+{
+	struct softnet_data *sd = this_cpu_ptr(&softnet_data);
+	unsigned long time_limit = jiffies +
+		usecs_to_jiffies(READ_ONCE(netdev_budget_usecs));
+	int budget = READ_ONCE(netdev_budget);
+	LIST_HEAD(list);
+	LIST_HEAD(repoll);
+
+	local_irq_disable();
+	list_splice_init(&sd->poll_list, &list);
+	local_irq_enable();
+
+	for (;;) {
+		struct napi_struct *n;
+
+		if (list_empty(&list)) {
+			if (!sd_has_rps_ipi_waiting(sd) && list_empty(&repoll))
+				goto out;
+			break;
+		}
+
+		n = list_first_entry(&list, struct napi_struct, poll_list);
+		budget -= napi_poll(n, &repoll);
+
+		/* If softirq window is exhausted then punt.
+		 * Allow this to run for 2 jiffies since which will allow
+		 * an average latency of 1.5/HZ.
+		 */
+		if (unlikely(budget <= 0 ||
+			     time_after_eq(jiffies, time_limit))) {
+			sd->time_squeeze++;
+			break;
+		}
+	}
+
+	local_irq_disable();
+
+	list_splice_tail_init(&sd->poll_list, &list);
+	list_splice_tail(&repoll, &list);
+	list_splice(&list, &sd->poll_list);
+	if (!list_empty(&sd->poll_list))
+		__raise_softirq_irqoff(NET_RX_SOFTIRQ);
+
+	net_rps_action_and_irq_enable(sd);
+out:
+	__kfree_skb_flush();
+}
+
+struct netdev_adjacent {
+	struct net_device *dev;
+
+	/* upper master flag, there can only be one master device per list */
+	bool master;
+
+	/* lookup ignore flag */
+	bool ignore;
+
+	/* counter for the number of times this device was added to us */
+	u16 ref_nr;
+
+	/* private field for the users */
+	void *private;
+
+	struct list_head list;
+	struct rcu_head rcu;
+};
+
+static struct netdev_adjacent *__netdev_find_adj(struct net_device *adj_dev,
+						 struct list_head *adj_list)
+{
+	struct netdev_adjacent *adj;
+
+	list_for_each_entry(adj, adj_list, list) {
+		if (adj->dev == adj_dev)
+			return adj;
+	}
+	return NULL;
+}
+
+static int ____netdev_has_upper_dev(struct net_device *upper_dev,
+				    struct netdev_nested_priv *priv)
+{
+	struct net_device *dev = (struct net_device *)priv->data;
+
+	return upper_dev == dev;
+}
+
+/**
+ * netdev_has_upper_dev - Check if device is linked to an upper device
+ * @dev: device
+ * @upper_dev: upper device to check
+ *
+ * Find out if a device is linked to specified upper device and return true
+ * in case it is. Note that this checks only immediate upper device,
+ * not through a complete stack of devices. The caller must hold the RTNL lock.
+ */
+bool netdev_has_upper_dev(struct net_device *dev,
+			  struct net_device *upper_dev)
+{
+	struct netdev_nested_priv priv = {
+		.data = (void *)upper_dev,
+	};
+
+	ASSERT_RTNL();
+
+	return netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
+					     &priv);
+}
+EXPORT_SYMBOL(netdev_has_upper_dev);
+
+/**
+ * netdev_has_upper_dev_all - Check if device is linked to an upper device
+ * @dev: device
+ * @upper_dev: upper device to check
+ *
+ * Find out if a device is linked to specified upper device and return true
+ * in case it is. Note that this checks the entire upper device chain.
+ * The caller must hold rcu lock.
+ */
+
+bool netdev_has_upper_dev_all_rcu(struct net_device *dev,
+				  struct net_device *upper_dev)
+{
+	struct netdev_nested_priv priv = {
+		.data = (void *)upper_dev,
+	};
+
+	return !!netdev_walk_all_upper_dev_rcu(dev, ____netdev_has_upper_dev,
+					       &priv);
+}
+EXPORT_SYMBOL(netdev_has_upper_dev_all_rcu);
+
+/**
+ * netdev_has_any_upper_dev - Check if device is linked to some device
+ * @dev: device
+ *
+ * Find out if a device is linked to an upper device and return true in case
+ * it is. The caller must hold the RTNL lock.
+ */
+bool netdev_has_any_upper_dev(struct net_device *dev)
+{
+	ASSERT_RTNL();
+
+	return !list_empty(&dev->adj_list.upper);
+}
+EXPORT_SYMBOL(netdev_has_any_upper_dev);
+
+/**
+ * netdev_master_upper_dev_get - Get master upper device
+ * @dev: device
+ *
+ * Find a master upper device and return pointer to it or NULL in case
+ * it's not there. The caller must hold the RTNL lock.
+ */
+struct net_device *netdev_master_upper_dev_get(struct net_device *dev)
+{
+	struct netdev_adjacent *upper;
+
+	ASSERT_RTNL();
+
+	if (list_empty(&dev->adj_list.upper))
+		return NULL;
+
+	upper = list_first_entry(&dev->adj_list.upper,
+				 struct netdev_adjacent, list);
+	if (likely(upper->master))
+		return upper->dev;
+	return NULL;
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_get);
+
+static struct net_device *__netdev_master_upper_dev_get(struct net_device *dev)
+{
+	struct netdev_adjacent *upper;
+
+	ASSERT_RTNL();
+
+	if (list_empty(&dev->adj_list.upper))
+		return NULL;
+
+	upper = list_first_entry(&dev->adj_list.upper,
+				 struct netdev_adjacent, list);
+	if (likely(upper->master) && !upper->ignore)
+		return upper->dev;
+	return NULL;
+}
+
+/**
+ * netdev_has_any_lower_dev - Check if device is linked to some device
+ * @dev: device
+ *
+ * Find out if a device is linked to a lower device and return true in case
+ * it is. The caller must hold the RTNL lock.
+ */
+static bool netdev_has_any_lower_dev(struct net_device *dev)
+{
+	ASSERT_RTNL();
+
+	return !list_empty(&dev->adj_list.lower);
+}
+
+void *netdev_adjacent_get_private(struct list_head *adj_list)
+{
+	struct netdev_adjacent *adj;
+
+	adj = list_entry(adj_list, struct netdev_adjacent, list);
+
+	return adj->private;
+}
+EXPORT_SYMBOL(netdev_adjacent_get_private);
+
+/**
+ * netdev_upper_get_next_dev_rcu - Get the next dev from upper list
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next device from the dev's upper list, starting from iter
+ * position. The caller must hold RCU read lock.
+ */
+struct net_device *netdev_upper_get_next_dev_rcu(struct net_device *dev,
+						 struct list_head **iter)
+{
+	struct netdev_adjacent *upper;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
+
+	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+
+	if (&upper->list == &dev->adj_list.upper)
+		return NULL;
+
+	*iter = &upper->list;
+
+	return upper->dev;
+}
+EXPORT_SYMBOL(netdev_upper_get_next_dev_rcu);
+
+static struct net_device *__netdev_next_upper_dev(struct net_device *dev,
+						  struct list_head **iter,
+						  bool *ignore)
+{
+	struct netdev_adjacent *upper;
+
+	upper = list_entry((*iter)->next, struct netdev_adjacent, list);
+
+	if (&upper->list == &dev->adj_list.upper)
+		return NULL;
+
+	*iter = &upper->list;
+	*ignore = upper->ignore;
+
+	return upper->dev;
+}
+
+static struct net_device *netdev_next_upper_dev_rcu(struct net_device *dev,
+						    struct list_head **iter)
+{
+	struct netdev_adjacent *upper;
+
+	WARN_ON_ONCE(!rcu_read_lock_held() && !lockdep_rtnl_is_held());
+
+	upper = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+
+	if (&upper->list == &dev->adj_list.upper)
+		return NULL;
+
+	*iter = &upper->list;
+
+	return upper->dev;
+}
+
+static int __netdev_walk_all_upper_dev(struct net_device *dev,
+				       int (*fn)(struct net_device *dev,
+					 struct netdev_nested_priv *priv),
+				       struct netdev_nested_priv *priv)
+{
+	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+	bool ignore;
+
+	now = dev;
+	iter = &dev->adj_list.upper;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, priv);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			udev = __netdev_next_upper_dev(now, &iter, &ignore);
+			if (!udev)
+				break;
+			if (ignore)
+				continue;
+
+			next = udev;
+			niter = &udev->adj_list.upper;
+			dev_stack[cur] = now;
+			iter_stack[cur++] = iter;
+			break;
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+
+int netdev_walk_all_upper_dev_rcu(struct net_device *dev,
+				  int (*fn)(struct net_device *dev,
+					    struct netdev_nested_priv *priv),
+				  struct netdev_nested_priv *priv)
+{
+	struct net_device *udev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+
+	now = dev;
+	iter = &dev->adj_list.upper;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, priv);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			udev = netdev_next_upper_dev_rcu(now, &iter);
+			if (!udev)
+				break;
+
+			next = udev;
+			niter = &udev->adj_list.upper;
+			dev_stack[cur] = now;
+			iter_stack[cur++] = iter;
+			break;
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(netdev_walk_all_upper_dev_rcu);
+
+static bool __netdev_has_upper_dev(struct net_device *dev,
+				   struct net_device *upper_dev)
+{
+	struct netdev_nested_priv priv = {
+		.flags = 0,
+		.data = (void *)upper_dev,
+	};
+
+	ASSERT_RTNL();
+
+	return __netdev_walk_all_upper_dev(dev, ____netdev_has_upper_dev,
+					   &priv);
+}
+
+/**
+ * netdev_lower_get_next_private - Get the next ->private from the
+ *				   lower neighbour list
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next netdev_adjacent->private from the dev's lower neighbour
+ * list, starting from iter position. The caller must hold either hold the
+ * RTNL lock or its own locking that guarantees that the neighbour lower
+ * list will remain unchanged.
+ */
+void *netdev_lower_get_next_private(struct net_device *dev,
+				    struct list_head **iter)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_entry(*iter, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = lower->list.next;
+
+	return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_get_next_private);
+
+/**
+ * netdev_lower_get_next_private_rcu - Get the next ->private from the
+ *				       lower neighbour list, RCU
+ *				       variant
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next netdev_adjacent->private from the dev's lower neighbour
+ * list, starting from iter position. The caller must hold RCU read lock.
+ */
+void *netdev_lower_get_next_private_rcu(struct net_device *dev,
+					struct list_head **iter)
+{
+	struct netdev_adjacent *lower;
+
+	WARN_ON_ONCE(!rcu_read_lock_held());
+
+	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = &lower->list;
+
+	return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_get_next_private_rcu);
+
+/**
+ * netdev_lower_get_next - Get the next device from the lower neighbour
+ *                         list
+ * @dev: device
+ * @iter: list_head ** of the current position
+ *
+ * Gets the next netdev_adjacent from the dev's lower neighbour
+ * list, starting from iter position. The caller must hold RTNL lock or
+ * its own locking that guarantees that the neighbour lower
+ * list will remain unchanged.
+ */
+void *netdev_lower_get_next(struct net_device *dev, struct list_head **iter)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_entry(*iter, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = lower->list.next;
+
+	return lower->dev;
+}
+EXPORT_SYMBOL(netdev_lower_get_next);
+
+static struct net_device *netdev_next_lower_dev(struct net_device *dev,
+						struct list_head **iter)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = &lower->list;
+
+	return lower->dev;
+}
+
+static struct net_device *__netdev_next_lower_dev(struct net_device *dev,
+						  struct list_head **iter,
+						  bool *ignore)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_entry((*iter)->next, struct netdev_adjacent, list);
+
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = &lower->list;
+	*ignore = lower->ignore;
+
+	return lower->dev;
+}
+
+int netdev_walk_all_lower_dev(struct net_device *dev,
+			      int (*fn)(struct net_device *dev,
+					struct netdev_nested_priv *priv),
+			      struct netdev_nested_priv *priv)
+{
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+
+	now = dev;
+	iter = &dev->adj_list.lower;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, priv);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			ldev = netdev_next_lower_dev(now, &iter);
+			if (!ldev)
+				break;
+
+			next = ldev;
+			niter = &ldev->adj_list.lower;
+			dev_stack[cur] = now;
+			iter_stack[cur++] = iter;
+			break;
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev);
+
+static int __netdev_walk_all_lower_dev(struct net_device *dev,
+				       int (*fn)(struct net_device *dev,
+					 struct netdev_nested_priv *priv),
+				       struct netdev_nested_priv *priv)
+{
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+	bool ignore;
+
+	now = dev;
+	iter = &dev->adj_list.lower;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, priv);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			ldev = __netdev_next_lower_dev(now, &iter, &ignore);
+			if (!ldev)
+				break;
+			if (ignore)
+				continue;
+
+			next = ldev;
+			niter = &ldev->adj_list.lower;
+			dev_stack[cur] = now;
+			iter_stack[cur++] = iter;
+			break;
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+
+struct net_device *netdev_next_lower_dev_rcu(struct net_device *dev,
+					     struct list_head **iter)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_entry_rcu((*iter)->next, struct netdev_adjacent, list);
+	if (&lower->list == &dev->adj_list.lower)
+		return NULL;
+
+	*iter = &lower->list;
+
+	return lower->dev;
+}
+EXPORT_SYMBOL(netdev_next_lower_dev_rcu);
+
+static u8 __netdev_upper_depth(struct net_device *dev)
+{
+	struct net_device *udev;
+	struct list_head *iter;
+	u8 max_depth = 0;
+	bool ignore;
+
+	for (iter = &dev->adj_list.upper,
+	     udev = __netdev_next_upper_dev(dev, &iter, &ignore);
+	     udev;
+	     udev = __netdev_next_upper_dev(dev, &iter, &ignore)) {
+		if (ignore)
+			continue;
+		if (max_depth < udev->upper_level)
+			max_depth = udev->upper_level;
+	}
+
+	return max_depth;
+}
+
+static u8 __netdev_lower_depth(struct net_device *dev)
+{
+	struct net_device *ldev;
+	struct list_head *iter;
+	u8 max_depth = 0;
+	bool ignore;
+
+	for (iter = &dev->adj_list.lower,
+	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore);
+	     ldev;
+	     ldev = __netdev_next_lower_dev(dev, &iter, &ignore)) {
+		if (ignore)
+			continue;
+		if (max_depth < ldev->lower_level)
+			max_depth = ldev->lower_level;
+	}
+
+	return max_depth;
+}
+
+static int __netdev_update_upper_level(struct net_device *dev,
+				       struct netdev_nested_priv *__unused)
+{
+	dev->upper_level = __netdev_upper_depth(dev) + 1;
+	return 0;
+}
+
+static int __netdev_update_lower_level(struct net_device *dev,
+				       struct netdev_nested_priv *priv)
+{
+	dev->lower_level = __netdev_lower_depth(dev) + 1;
+
+#ifdef CONFIG_LOCKDEP
+	if (!priv)
+		return 0;
+
+	if (priv->flags & NESTED_SYNC_IMM)
+		dev->nested_level = dev->lower_level - 1;
+	if (priv->flags & NESTED_SYNC_TODO)
+		net_unlink_todo(dev);
+#endif
+	return 0;
+}
+
+int netdev_walk_all_lower_dev_rcu(struct net_device *dev,
+				  int (*fn)(struct net_device *dev,
+					    struct netdev_nested_priv *priv),
+				  struct netdev_nested_priv *priv)
+{
+	struct net_device *ldev, *next, *now, *dev_stack[MAX_NEST_DEV + 1];
+	struct list_head *niter, *iter, *iter_stack[MAX_NEST_DEV + 1];
+	int ret, cur = 0;
+
+	now = dev;
+	iter = &dev->adj_list.lower;
+
+	while (1) {
+		if (now != dev) {
+			ret = fn(now, priv);
+			if (ret)
+				return ret;
+		}
+
+		next = NULL;
+		while (1) {
+			ldev = netdev_next_lower_dev_rcu(now, &iter);
+			if (!ldev)
+				break;
+
+			next = ldev;
+			niter = &ldev->adj_list.lower;
+			dev_stack[cur] = now;
+			iter_stack[cur++] = iter;
+			break;
+		}
+
+		if (!next) {
+			if (!cur)
+				return 0;
+			next = dev_stack[--cur];
+			niter = iter_stack[cur];
+		}
+
+		now = next;
+		iter = niter;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(netdev_walk_all_lower_dev_rcu);
+
+/**
+ * netdev_lower_get_first_private_rcu - Get the first ->private from the
+ *				       lower neighbour list, RCU
+ *				       variant
+ * @dev: device
+ *
+ * Gets the first netdev_adjacent->private from the dev's lower neighbour
+ * list. The caller must hold RCU read lock.
+ */
+void *netdev_lower_get_first_private_rcu(struct net_device *dev)
+{
+	struct netdev_adjacent *lower;
+
+	lower = list_first_or_null_rcu(&dev->adj_list.lower,
+			struct netdev_adjacent, list);
+	if (lower)
+		return lower->private;
+	return NULL;
+}
+EXPORT_SYMBOL(netdev_lower_get_first_private_rcu);
+
+/**
+ * netdev_master_upper_dev_get_rcu - Get master upper device
+ * @dev: device
+ *
+ * Find a master upper device and return pointer to it or NULL in case
+ * it's not there. The caller must hold the RCU read lock.
+ */
+struct net_device *netdev_master_upper_dev_get_rcu(struct net_device *dev)
+{
+	struct netdev_adjacent *upper;
+
+	upper = list_first_or_null_rcu(&dev->adj_list.upper,
+				       struct netdev_adjacent, list);
+	if (upper && likely(upper->master))
+		return upper->dev;
+	return NULL;
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_get_rcu);
+
+static int netdev_adjacent_sysfs_add(struct net_device *dev,
+			      struct net_device *adj_dev,
+			      struct list_head *dev_list)
+{
+	char linkname[IFNAMSIZ+7];
+
+	sprintf(linkname, dev_list == &dev->adj_list.upper ?
+		"upper_%s" : "lower_%s", adj_dev->name);
+	return sysfs_create_link(&(dev->dev.kobj), &(adj_dev->dev.kobj),
+				 linkname);
+}
+static void netdev_adjacent_sysfs_del(struct net_device *dev,
+			       char *name,
+			       struct list_head *dev_list)
+{
+	char linkname[IFNAMSIZ+7];
+
+	sprintf(linkname, dev_list == &dev->adj_list.upper ?
+		"upper_%s" : "lower_%s", name);
+	sysfs_remove_link(&(dev->dev.kobj), linkname);
+}
+
+static inline bool netdev_adjacent_is_neigh_list(struct net_device *dev,
+						 struct net_device *adj_dev,
+						 struct list_head *dev_list)
+{
+	return (dev_list == &dev->adj_list.upper ||
+		dev_list == &dev->adj_list.lower) &&
+		net_eq(dev_net(dev), dev_net(adj_dev));
+}
+
+static int __netdev_adjacent_dev_insert(struct net_device *dev,
+					struct net_device *adj_dev,
+					struct list_head *dev_list,
+					void *private, bool master)
+{
+	struct netdev_adjacent *adj;
+	int ret;
+
+	adj = __netdev_find_adj(adj_dev, dev_list);
+
+	if (adj) {
+		adj->ref_nr += 1;
+		pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d\n",
+			 dev->name, adj_dev->name, adj->ref_nr);
+
+		return 0;
+	}
+
+	adj = kmalloc(sizeof(*adj), GFP_KERNEL);
+	if (!adj)
+		return -ENOMEM;
+
+	adj->dev = adj_dev;
+	adj->master = master;
+	adj->ref_nr = 1;
+	adj->private = private;
+	adj->ignore = false;
+	dev_hold(adj_dev);
+
+	pr_debug("Insert adjacency: dev %s adj_dev %s adj->ref_nr %d; dev_hold on %s\n",
+		 dev->name, adj_dev->name, adj->ref_nr, adj_dev->name);
+
+	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list)) {
+		ret = netdev_adjacent_sysfs_add(dev, adj_dev, dev_list);
+		if (ret)
+			goto free_adj;
+	}
+
+	/* Ensure that master link is always the first item in list. */
+	if (master) {
+		ret = sysfs_create_link(&(dev->dev.kobj),
+					&(adj_dev->dev.kobj), "master");
+		if (ret)
+			goto remove_symlinks;
+
+		list_add_rcu(&adj->list, dev_list);
+	} else {
+		list_add_tail_rcu(&adj->list, dev_list);
+	}
+
+	return 0;
+
+remove_symlinks:
+	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
+		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
+free_adj:
+	kfree(adj);
+	dev_put(adj_dev);
+
+	return ret;
+}
+
+static void __netdev_adjacent_dev_remove(struct net_device *dev,
+					 struct net_device *adj_dev,
+					 u16 ref_nr,
+					 struct list_head *dev_list)
+{
+	struct netdev_adjacent *adj;
+
+	pr_debug("Remove adjacency: dev %s adj_dev %s ref_nr %d\n",
+		 dev->name, adj_dev->name, ref_nr);
+
+	adj = __netdev_find_adj(adj_dev, dev_list);
+
+	if (!adj) {
+		pr_err("Adjacency does not exist for device %s from %s\n",
+		       dev->name, adj_dev->name);
+		WARN_ON(1);
+		return;
+	}
+
+	if (adj->ref_nr > ref_nr) {
+		pr_debug("adjacency: %s to %s ref_nr - %d = %d\n",
+			 dev->name, adj_dev->name, ref_nr,
+			 adj->ref_nr - ref_nr);
+		adj->ref_nr -= ref_nr;
+		return;
+	}
+
+	if (adj->master)
+		sysfs_remove_link(&(dev->dev.kobj), "master");
+
+	if (netdev_adjacent_is_neigh_list(dev, adj_dev, dev_list))
+		netdev_adjacent_sysfs_del(dev, adj_dev->name, dev_list);
+
+	list_del_rcu(&adj->list);
+	pr_debug("adjacency: dev_put for %s, because link removed from %s to %s\n",
+		 adj_dev->name, dev->name, adj_dev->name);
+	dev_put(adj_dev);
+	kfree_rcu(adj, rcu);
+}
+
+static int __netdev_adjacent_dev_link_lists(struct net_device *dev,
+					    struct net_device *upper_dev,
+					    struct list_head *up_list,
+					    struct list_head *down_list,
+					    void *private, bool master)
+{
+	int ret;
+
+	ret = __netdev_adjacent_dev_insert(dev, upper_dev, up_list,
+					   private, master);
+	if (ret)
+		return ret;
+
+	ret = __netdev_adjacent_dev_insert(upper_dev, dev, down_list,
+					   private, false);
+	if (ret) {
+		__netdev_adjacent_dev_remove(dev, upper_dev, 1, up_list);
+		return ret;
+	}
+
+	return 0;
+}
+
+static void __netdev_adjacent_dev_unlink_lists(struct net_device *dev,
+					       struct net_device *upper_dev,
+					       u16 ref_nr,
+					       struct list_head *up_list,
+					       struct list_head *down_list)
+{
+	__netdev_adjacent_dev_remove(dev, upper_dev, ref_nr, up_list);
+	__netdev_adjacent_dev_remove(upper_dev, dev, ref_nr, down_list);
+}
+
+static int __netdev_adjacent_dev_link_neighbour(struct net_device *dev,
+						struct net_device *upper_dev,
+						void *private, bool master)
+{
+	return __netdev_adjacent_dev_link_lists(dev, upper_dev,
+						&dev->adj_list.upper,
+						&upper_dev->adj_list.lower,
+						private, master);
+}
+
+static void __netdev_adjacent_dev_unlink_neighbour(struct net_device *dev,
+						   struct net_device *upper_dev)
+{
+	__netdev_adjacent_dev_unlink_lists(dev, upper_dev, 1,
+					   &dev->adj_list.upper,
+					   &upper_dev->adj_list.lower);
+}
+
+static int __netdev_upper_dev_link(struct net_device *dev,
+				   struct net_device *upper_dev, bool master,
+				   void *upper_priv, void *upper_info,
+				   struct netdev_nested_priv *priv,
+				   struct netlink_ext_ack *extack)
+{
+	struct netdev_notifier_changeupper_info changeupper_info = {
+		.info = {
+			.dev = dev,
+			.extack = extack,
+		},
+		.upper_dev = upper_dev,
+		.master = master,
+		.linking = true,
+		.upper_info = upper_info,
+	};
+	struct net_device *master_dev;
+	int ret = 0;
+
+	ASSERT_RTNL();
+
+	if (dev == upper_dev)
+		return -EBUSY;
+
+	/* To prevent loops, check if dev is not upper device to upper_dev. */
+	if (__netdev_has_upper_dev(upper_dev, dev))
+		return -EBUSY;
+
+	if ((dev->lower_level + upper_dev->upper_level) > MAX_NEST_DEV)
+		return -EMLINK;
+
+	if (!master) {
+		if (__netdev_has_upper_dev(dev, upper_dev))
+			return -EEXIST;
+	} else {
+		master_dev = __netdev_master_upper_dev_get(dev);
+		if (master_dev)
+			return master_dev == upper_dev ? -EEXIST : -EBUSY;
+	}
+
+	ret = call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
+					    &changeupper_info.info);
+	ret = notifier_to_errno(ret);
+	if (ret)
+		return ret;
+
+	ret = __netdev_adjacent_dev_link_neighbour(dev, upper_dev, upper_priv,
+						   master);
+	if (ret)
+		return ret;
+
+	ret = call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
+					    &changeupper_info.info);
+	ret = notifier_to_errno(ret);
+	if (ret)
+		goto rollback;
+
+	__netdev_update_upper_level(dev, NULL);
+	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
+
+	__netdev_update_lower_level(upper_dev, priv);
+	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
+				    priv);
+
+	return 0;
+
+rollback:
+	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
+
+	return ret;
+}
+
+/**
+ * netdev_upper_dev_link - Add a link to the upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ * @extack: netlink extended ack
+ *
+ * Adds a link to device which is upper to this one. The caller must hold
+ * the RTNL lock. On a failure a negative errno code is returned.
+ * On success the reference counts are adjusted and the function
+ * returns zero.
+ */
+int netdev_upper_dev_link(struct net_device *dev,
+			  struct net_device *upper_dev,
+			  struct netlink_ext_ack *extack)
+{
+	struct netdev_nested_priv priv = {
+		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
+		.data = NULL,
+	};
+
+	return __netdev_upper_dev_link(dev, upper_dev, false,
+				       NULL, NULL, &priv, extack);
+}
+EXPORT_SYMBOL(netdev_upper_dev_link);
+
+/**
+ * netdev_master_upper_dev_link - Add a master link to the upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ * @upper_priv: upper device private
+ * @upper_info: upper info to be passed down via notifier
+ * @extack: netlink extended ack
+ *
+ * Adds a link to device which is upper to this one. In this case, only
+ * one master upper device can be linked, although other non-master devices
+ * might be linked as well. The caller must hold the RTNL lock.
+ * On a failure a negative errno code is returned. On success the reference
+ * counts are adjusted and the function returns zero.
+ */
+int netdev_master_upper_dev_link(struct net_device *dev,
+				 struct net_device *upper_dev,
+				 void *upper_priv, void *upper_info,
+				 struct netlink_ext_ack *extack)
+{
+	struct netdev_nested_priv priv = {
+		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
+		.data = NULL,
+	};
+
+	return __netdev_upper_dev_link(dev, upper_dev, true,
+				       upper_priv, upper_info, &priv, extack);
+}
+EXPORT_SYMBOL(netdev_master_upper_dev_link);
+
+static void __netdev_upper_dev_unlink(struct net_device *dev,
+				      struct net_device *upper_dev,
+				      struct netdev_nested_priv *priv)
+{
+	struct netdev_notifier_changeupper_info changeupper_info = {
+		.info = {
+			.dev = dev,
+		},
+		.upper_dev = upper_dev,
+		.linking = false,
+	};
+
+	ASSERT_RTNL();
+
+	changeupper_info.master = netdev_master_upper_dev_get(dev) == upper_dev;
+
+	call_netdevice_notifiers_info(NETDEV_PRECHANGEUPPER,
+				      &changeupper_info.info);
+
+	__netdev_adjacent_dev_unlink_neighbour(dev, upper_dev);
+
+	call_netdevice_notifiers_info(NETDEV_CHANGEUPPER,
+				      &changeupper_info.info);
+
+	__netdev_update_upper_level(dev, NULL);
+	__netdev_walk_all_lower_dev(dev, __netdev_update_upper_level, NULL);
+
+	__netdev_update_lower_level(upper_dev, priv);
+	__netdev_walk_all_upper_dev(upper_dev, __netdev_update_lower_level,
+				    priv);
+}
+
+/**
+ * netdev_upper_dev_unlink - Removes a link to upper device
+ * @dev: device
+ * @upper_dev: new upper device
+ *
+ * Removes a link to device which is upper to this one. The caller must hold
+ * the RTNL lock.
+ */
+void netdev_upper_dev_unlink(struct net_device *dev,
+			     struct net_device *upper_dev)
+{
+	struct netdev_nested_priv priv = {
+		.flags = NESTED_SYNC_TODO,
+		.data = NULL,
+	};
+
+	__netdev_upper_dev_unlink(dev, upper_dev, &priv);
+}
+EXPORT_SYMBOL(netdev_upper_dev_unlink);
+
+static void __netdev_adjacent_dev_set(struct net_device *upper_dev,
+				      struct net_device *lower_dev,
+				      bool val)
+{
+	struct netdev_adjacent *adj;
+
+	adj = __netdev_find_adj(lower_dev, &upper_dev->adj_list.lower);
+	if (adj)
+		adj->ignore = val;
+
+	adj = __netdev_find_adj(upper_dev, &lower_dev->adj_list.upper);
+	if (adj)
+		adj->ignore = val;
+}
+
+static void netdev_adjacent_dev_disable(struct net_device *upper_dev,
+					struct net_device *lower_dev)
+{
+	__netdev_adjacent_dev_set(upper_dev, lower_dev, true);
+}
+
+static void netdev_adjacent_dev_enable(struct net_device *upper_dev,
+				       struct net_device *lower_dev)
+{
+	__netdev_adjacent_dev_set(upper_dev, lower_dev, false);
+}
+
+int netdev_adjacent_change_prepare(struct net_device *old_dev,
+				   struct net_device *new_dev,
+				   struct net_device *dev,
+				   struct netlink_ext_ack *extack)
+{
+	struct netdev_nested_priv priv = {
+		.flags = 0,
+		.data = NULL,
+	};
+	int err;
+
+	if (!new_dev)
+		return 0;
+
+	if (old_dev && new_dev != old_dev)
+		netdev_adjacent_dev_disable(dev, old_dev);
+	err = __netdev_upper_dev_link(new_dev, dev, false, NULL, NULL, &priv,
+				      extack);
+	if (err) {
+		if (old_dev && new_dev != old_dev)
+			netdev_adjacent_dev_enable(dev, old_dev);
+		return err;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(netdev_adjacent_change_prepare);
+
+void netdev_adjacent_change_commit(struct net_device *old_dev,
+				   struct net_device *new_dev,
+				   struct net_device *dev)
+{
+	struct netdev_nested_priv priv = {
+		.flags = NESTED_SYNC_IMM | NESTED_SYNC_TODO,
+		.data = NULL,
+	};
+
+	if (!new_dev || !old_dev)
+		return;
+
+	if (new_dev == old_dev)
+		return;
+
+	netdev_adjacent_dev_enable(dev, old_dev);
+	__netdev_upper_dev_unlink(old_dev, dev, &priv);
+}
+EXPORT_SYMBOL(netdev_adjacent_change_commit);
+
+void netdev_adjacent_change_abort(struct net_device *old_dev,
+				  struct net_device *new_dev,
+				  struct net_device *dev)
+{
+	struct netdev_nested_priv priv = {
+		.flags = 0,
+		.data = NULL,
+	};
+
+	if (!new_dev)
+		return;
+
+	if (old_dev && new_dev != old_dev)
+		netdev_adjacent_dev_enable(dev, old_dev);
+
+	__netdev_upper_dev_unlink(new_dev, dev, &priv);
+}
+EXPORT_SYMBOL(netdev_adjacent_change_abort);
+
+/**
+ * netdev_bonding_info_change - Dispatch event about slave change
+ * @dev: device
+ * @bonding_info: info to dispatch
+ *
+ * Send NETDEV_BONDING_INFO to netdev notifiers with info.
+ * The caller must hold the RTNL lock.
+ */
+void netdev_bonding_info_change(struct net_device *dev,
+				struct netdev_bonding_info *bonding_info)
+{
+	struct netdev_notifier_bonding_info info = {
+		.info.dev = dev,
+	};
+
+	memcpy(&info.bonding_info, bonding_info,
+	       sizeof(struct netdev_bonding_info));
+	call_netdevice_notifiers_info(NETDEV_BONDING_INFO,
+				      &info.info);
+}
+EXPORT_SYMBOL(netdev_bonding_info_change);
+
+/**
+ * netdev_get_xmit_slave - Get the xmit slave of master device
+ * @dev: device
+ * @skb: The packet
+ * @all_slaves: assume all the slaves are active
+ *
+ * The reference counters are not incremented so the caller must be
+ * careful with locks. The caller must hold RCU lock.
+ * %NULL is returned if no slave is found.
+ */
+
+struct net_device *netdev_get_xmit_slave(struct net_device *dev,
+					 struct sk_buff *skb,
+					 bool all_slaves)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_get_xmit_slave)
+		return NULL;
+	return ops->ndo_get_xmit_slave(dev, skb, all_slaves);
+}
+EXPORT_SYMBOL(netdev_get_xmit_slave);
+
+static void netdev_adjacent_add_links(struct net_device *dev)
+{
+	struct netdev_adjacent *iter;
+
+	struct net *net = dev_net(dev);
+
+	list_for_each_entry(iter, &dev->adj_list.upper, list) {
+		if (!net_eq(net, dev_net(iter->dev)))
+			continue;
+		netdev_adjacent_sysfs_add(iter->dev, dev,
+					  &iter->dev->adj_list.lower);
+		netdev_adjacent_sysfs_add(dev, iter->dev,
+					  &dev->adj_list.upper);
+	}
+
+	list_for_each_entry(iter, &dev->adj_list.lower, list) {
+		if (!net_eq(net, dev_net(iter->dev)))
+			continue;
+		netdev_adjacent_sysfs_add(iter->dev, dev,
+					  &iter->dev->adj_list.upper);
+		netdev_adjacent_sysfs_add(dev, iter->dev,
+					  &dev->adj_list.lower);
+	}
+}
+
+static void netdev_adjacent_del_links(struct net_device *dev)
+{
+	struct netdev_adjacent *iter;
+
+	struct net *net = dev_net(dev);
+
+	list_for_each_entry(iter, &dev->adj_list.upper, list) {
+		if (!net_eq(net, dev_net(iter->dev)))
+			continue;
+		netdev_adjacent_sysfs_del(iter->dev, dev->name,
+					  &iter->dev->adj_list.lower);
+		netdev_adjacent_sysfs_del(dev, iter->dev->name,
+					  &dev->adj_list.upper);
+	}
+
+	list_for_each_entry(iter, &dev->adj_list.lower, list) {
+		if (!net_eq(net, dev_net(iter->dev)))
+			continue;
+		netdev_adjacent_sysfs_del(iter->dev, dev->name,
+					  &iter->dev->adj_list.upper);
+		netdev_adjacent_sysfs_del(dev, iter->dev->name,
+					  &dev->adj_list.lower);
+	}
+}
+
+void netdev_adjacent_rename_links(struct net_device *dev, char *oldname)
+{
+	struct netdev_adjacent *iter;
+
+	struct net *net = dev_net(dev);
+
+	list_for_each_entry(iter, &dev->adj_list.upper, list) {
+		if (!net_eq(net, dev_net(iter->dev)))
+			continue;
+		netdev_adjacent_sysfs_del(iter->dev, oldname,
+					  &iter->dev->adj_list.lower);
+		netdev_adjacent_sysfs_add(iter->dev, dev,
+					  &iter->dev->adj_list.lower);
+	}
+
+	list_for_each_entry(iter, &dev->adj_list.lower, list) {
+		if (!net_eq(net, dev_net(iter->dev)))
+			continue;
+		netdev_adjacent_sysfs_del(iter->dev, oldname,
+					  &iter->dev->adj_list.upper);
+		netdev_adjacent_sysfs_add(iter->dev, dev,
+					  &iter->dev->adj_list.upper);
+	}
+}
+
+void *netdev_lower_dev_get_private(struct net_device *dev,
+				   struct net_device *lower_dev)
+{
+	struct netdev_adjacent *lower;
+
+	if (!lower_dev)
+		return NULL;
+	lower = __netdev_find_adj(lower_dev, &dev->adj_list.lower);
+	if (!lower)
+		return NULL;
+
+	return lower->private;
+}
+EXPORT_SYMBOL(netdev_lower_dev_get_private);
+
+
+/**
+ * netdev_lower_change - Dispatch event about lower device state change
+ * @lower_dev: device
+ * @lower_state_info: state to dispatch
+ *
+ * Send NETDEV_CHANGELOWERSTATE to netdev notifiers with info.
+ * The caller must hold the RTNL lock.
+ */
+void netdev_lower_state_changed(struct net_device *lower_dev,
+				void *lower_state_info)
+{
+	struct netdev_notifier_changelowerstate_info changelowerstate_info = {
+		.info.dev = lower_dev,
+	};
+
+	ASSERT_RTNL();
+	changelowerstate_info.lower_state_info = lower_state_info;
+	call_netdevice_notifiers_info(NETDEV_CHANGELOWERSTATE,
+				      &changelowerstate_info.info);
+}
+EXPORT_SYMBOL(netdev_lower_state_changed);
+
+static void dev_change_rx_flags(struct net_device *dev, int flags)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (ops->ndo_change_rx_flags)
+		ops->ndo_change_rx_flags(dev, flags);
+}
+
+static int __dev_set_promiscuity(struct net_device *dev, int inc, bool notify)
+{
+	unsigned int old_flags = dev->flags;
+	kuid_t uid;
+	kgid_t gid;
+
+	ASSERT_RTNL();
+
+	dev->flags |= IFF_PROMISC;
+	dev->promiscuity += inc;
+	if (dev->promiscuity == 0) {
+		/*
+		 * Avoid overflow.
+		 * If inc causes overflow, untouch promisc and return error.
+		 */
+		if (inc < 0)
+			dev->flags &= ~IFF_PROMISC;
+		else {
+			dev->promiscuity -= inc;
+			pr_warn("%s: promiscuity touches roof, set promiscuity failed. promiscuity feature of device might be broken.\n",
+				dev->name);
+			return -EOVERFLOW;
+		}
+	}
+	if (dev->flags != old_flags) {
+		pr_info("device %s %s promiscuous mode\n",
+			dev->name,
+			dev->flags & IFF_PROMISC ? "entered" : "left");
+		if (audit_enabled) {
+			current_uid_gid(&uid, &gid);
+			audit_log(audit_context(), GFP_ATOMIC,
+				  AUDIT_ANOM_PROMISCUOUS,
+				  "dev=%s prom=%d old_prom=%d auid=%u uid=%u gid=%u ses=%u",
+				  dev->name, (dev->flags & IFF_PROMISC),
+				  (old_flags & IFF_PROMISC),
+				  from_kuid(&init_user_ns, audit_get_loginuid(current)),
+				  from_kuid(&init_user_ns, uid),
+				  from_kgid(&init_user_ns, gid),
+				  audit_get_sessionid(current));
+		}
+
+		dev_change_rx_flags(dev, IFF_PROMISC);
+	}
+	if (notify)
+		__dev_notify_flags(dev, old_flags, IFF_PROMISC);
+	return 0;
+}
+
+/**
+ *	dev_set_promiscuity	- update promiscuity count on a device
+ *	@dev: device
+ *	@inc: modifier
+ *
+ *	Add or remove promiscuity from a device. While the count in the device
+ *	remains above zero the interface remains promiscuous. Once it hits zero
+ *	the device reverts back to normal filtering operation. A negative inc
+ *	value is used to drop promiscuity on the device.
+ *	Return 0 if successful or a negative errno code on error.
+ */
+int dev_set_promiscuity(struct net_device *dev, int inc)
+{
+	unsigned int old_flags = dev->flags;
+	int err;
+
+	err = __dev_set_promiscuity(dev, inc, true);
+	if (err < 0)
+		return err;
+	if (dev->flags != old_flags)
+		dev_set_rx_mode(dev);
+	return err;
+}
+EXPORT_SYMBOL(dev_set_promiscuity);
+
+static int __dev_set_allmulti(struct net_device *dev, int inc, bool notify)
+{
+	unsigned int old_flags = dev->flags, old_gflags = dev->gflags;
+
+	ASSERT_RTNL();
+
+	dev->flags |= IFF_ALLMULTI;
+	dev->allmulti += inc;
+	if (dev->allmulti == 0) {
+		/*
+		 * Avoid overflow.
+		 * If inc causes overflow, untouch allmulti and return error.
+		 */
+		if (inc < 0)
+			dev->flags &= ~IFF_ALLMULTI;
+		else {
+			dev->allmulti -= inc;
+			pr_warn("%s: allmulti touches roof, set allmulti failed. allmulti feature of device might be broken.\n",
+				dev->name);
+			return -EOVERFLOW;
+		}
+	}
+	if (dev->flags ^ old_flags) {
+		dev_change_rx_flags(dev, IFF_ALLMULTI);
+		dev_set_rx_mode(dev);
+		if (notify)
+			__dev_notify_flags(dev, old_flags,
+					   dev->gflags ^ old_gflags);
+	}
+	return 0;
+}
+
+/**
+ *	dev_set_allmulti	- update allmulti count on a device
+ *	@dev: device
+ *	@inc: modifier
+ *
+ *	Add or remove reception of all multicast frames to a device. While the
+ *	count in the device remains above zero the interface remains listening
+ *	to all interfaces. Once it hits zero the device reverts back to normal
+ *	filtering operation. A negative @inc value is used to drop the counter
+ *	when releasing a resource needing all multicasts.
+ *	Return 0 if successful or a negative errno code on error.
+ */
+
+int dev_set_allmulti(struct net_device *dev, int inc)
+{
+	return __dev_set_allmulti(dev, inc, true);
+}
+EXPORT_SYMBOL(dev_set_allmulti);
+
+/*
+ *	Upload unicast and multicast address lists to device and
+ *	configure RX filtering. When the device doesn't support unicast
+ *	filtering it is put in promiscuous mode while unicast addresses
+ *	are present.
+ */
+void __dev_set_rx_mode(struct net_device *dev)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	/* dev_open will call this function so the list will stay sane. */
+	if (!(dev->flags&IFF_UP))
+		return;
+
+	if (!netif_device_present(dev))
+		return;
+
+	if (!(dev->priv_flags & IFF_UNICAST_FLT)) {
+		/* Unicast addresses changes may only happen under the rtnl,
+		 * therefore calling __dev_set_promiscuity here is safe.
+		 */
+		if (!netdev_uc_empty(dev) && !dev->uc_promisc) {
+			__dev_set_promiscuity(dev, 1, false);
+			dev->uc_promisc = true;
+		} else if (netdev_uc_empty(dev) && dev->uc_promisc) {
+			__dev_set_promiscuity(dev, -1, false);
+			dev->uc_promisc = false;
+		}
+	}
+
+	if (ops->ndo_set_rx_mode)
+		ops->ndo_set_rx_mode(dev);
+}
+
+void dev_set_rx_mode(struct net_device *dev)
+{
+	netif_addr_lock_bh(dev);
+	__dev_set_rx_mode(dev);
+	netif_addr_unlock_bh(dev);
+}
+
+/**
+ *	dev_get_flags - get flags reported to userspace
+ *	@dev: device
+ *
+ *	Get the combination of flag bits exported through APIs to userspace.
+ */
+unsigned int dev_get_flags(const struct net_device *dev)
+{
+	unsigned int flags;
+
+	flags = (dev->flags & ~(IFF_PROMISC |
+				IFF_ALLMULTI |
+				IFF_RUNNING |
+				IFF_LOWER_UP |
+				IFF_DORMANT)) |
+		(dev->gflags & (IFF_PROMISC |
+				IFF_ALLMULTI));
+
+	if (netif_running(dev)) {
+		if (netif_oper_up(dev))
+			flags |= IFF_RUNNING;
+		if (netif_carrier_ok(dev))
+			flags |= IFF_LOWER_UP;
+		if (netif_dormant(dev))
+			flags |= IFF_DORMANT;
+	}
+
+	return flags;
+}
+EXPORT_SYMBOL(dev_get_flags);
+
+int __dev_change_flags(struct net_device *dev, unsigned int flags,
+		       struct netlink_ext_ack *extack)
+{
+	unsigned int old_flags = dev->flags;
+	int ret;
+
+	ASSERT_RTNL();
+
+	/*
+	 *	Set the flags on our device.
+	 */
+
+	dev->flags = (flags & (IFF_DEBUG | IFF_NOTRAILERS | IFF_NOARP |
+			       IFF_DYNAMIC | IFF_MULTICAST | IFF_PORTSEL |
+			       IFF_AUTOMEDIA)) |
+		     (dev->flags & (IFF_UP | IFF_VOLATILE | IFF_PROMISC |
+				    IFF_ALLMULTI));
+
+	/*
+	 *	Load in the correct multicast list now the flags have changed.
+	 */
+
+	if ((old_flags ^ flags) & IFF_MULTICAST)
+		dev_change_rx_flags(dev, IFF_MULTICAST);
+
+	dev_set_rx_mode(dev);
+
+	/*
+	 *	Have we downed the interface. We handle IFF_UP ourselves
+	 *	according to user attempts to set it, rather than blindly
+	 *	setting it.
+	 */
+
+	ret = 0;
+	if ((old_flags ^ flags) & IFF_UP) {
+		if (old_flags & IFF_UP)
+			__dev_close(dev);
+		else
+			ret = __dev_open(dev, extack);
+	}
+
+	if ((flags ^ dev->gflags) & IFF_PROMISC) {
+		int inc = (flags & IFF_PROMISC) ? 1 : -1;
+		unsigned int old_flags = dev->flags;
+
+		dev->gflags ^= IFF_PROMISC;
+
+		if (__dev_set_promiscuity(dev, inc, false) >= 0)
+			if (dev->flags != old_flags)
+				dev_set_rx_mode(dev);
+	}
+
+	/* NOTE: order of synchronization of IFF_PROMISC and IFF_ALLMULTI
+	 * is important. Some (broken) drivers set IFF_PROMISC, when
+	 * IFF_ALLMULTI is requested not asking us and not reporting.
+	 */
+	if ((flags ^ dev->gflags) & IFF_ALLMULTI) {
+		int inc = (flags & IFF_ALLMULTI) ? 1 : -1;
+
+		dev->gflags ^= IFF_ALLMULTI;
+		__dev_set_allmulti(dev, inc, false);
+	}
+
+	return ret;
+}
+
+void __dev_notify_flags(struct net_device *dev, unsigned int old_flags,
+			unsigned int gchanges)
+{
+	unsigned int changes = dev->flags ^ old_flags;
+
+	if (gchanges)
+		rtmsg_ifinfo(RTM_NEWLINK, dev, gchanges, GFP_ATOMIC);
+
+	if (changes & IFF_UP) {
+		if (dev->flags & IFF_UP)
+			call_netdevice_notifiers(NETDEV_UP, dev);
+		else
+			call_netdevice_notifiers(NETDEV_DOWN, dev);
+	}
+
+	if (dev->flags & IFF_UP &&
+	    (changes & ~(IFF_UP | IFF_PROMISC | IFF_ALLMULTI | IFF_VOLATILE))) {
+		struct netdev_notifier_change_info change_info = {
+			.info = {
+				.dev = dev,
+			},
+			.flags_changed = changes,
+		};
+
+		call_netdevice_notifiers_info(NETDEV_CHANGE, &change_info.info);
+	}
+}
+
+/**
+ *	dev_change_flags - change device settings
+ *	@dev: device
+ *	@flags: device state flags
+ *	@extack: netlink extended ack
+ *
+ *	Change settings on device based state flags. The flags are
+ *	in the userspace exported format.
+ */
+int dev_change_flags(struct net_device *dev, unsigned int flags,
+		     struct netlink_ext_ack *extack)
+{
+	int ret;
+	unsigned int changes, old_flags = dev->flags, old_gflags = dev->gflags;
+
+	ret = __dev_change_flags(dev, flags, extack);
+	if (ret < 0)
+		return ret;
+
+	changes = (old_flags ^ dev->flags) | (old_gflags ^ dev->gflags);
+	__dev_notify_flags(dev, old_flags, changes);
+	return ret;
+}
+EXPORT_SYMBOL(dev_change_flags);
+
+int __dev_set_mtu(struct net_device *dev, int new_mtu)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (ops->ndo_change_mtu)
+		return ops->ndo_change_mtu(dev, new_mtu);
+
+	/* Pairs with all the lockless reads of dev->mtu in the stack */
+	WRITE_ONCE(dev->mtu, new_mtu);
+	return 0;
+}
+EXPORT_SYMBOL(__dev_set_mtu);
+
+int dev_validate_mtu(struct net_device *dev, int new_mtu,
+		     struct netlink_ext_ack *extack)
+{
+	/* MTU must be positive, and in range */
+	if (new_mtu < 0 || new_mtu < dev->min_mtu) {
+		NL_SET_ERR_MSG(extack, "mtu less than device minimum");
+		return -EINVAL;
+	}
+
+	if (dev->max_mtu > 0 && new_mtu > dev->max_mtu) {
+		NL_SET_ERR_MSG(extack, "mtu greater than device maximum");
+		return -EINVAL;
+	}
+	return 0;
+}
+
+/**
+ *	dev_set_mtu_ext - Change maximum transfer unit
+ *	@dev: device
+ *	@new_mtu: new transfer unit
+ *	@extack: netlink extended ack
+ *
+ *	Change the maximum transfer size of the network device.
+ */
+int dev_set_mtu_ext(struct net_device *dev, int new_mtu,
+		    struct netlink_ext_ack *extack)
+{
+	int err, orig_mtu;
+
+	if (new_mtu == dev->mtu)
+		return 0;
+
+	err = dev_validate_mtu(dev, new_mtu, extack);
+	if (err)
+		return err;
+
+	if (!netif_device_present(dev))
+		return -ENODEV;
+
+	err = call_netdevice_notifiers(NETDEV_PRECHANGEMTU, dev);
+	err = notifier_to_errno(err);
+	if (err)
+		return err;
+
+	orig_mtu = dev->mtu;
+	err = __dev_set_mtu(dev, new_mtu);
+
+	if (!err) {
+		err = call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
+						   orig_mtu);
+		err = notifier_to_errno(err);
+		if (err) {
+			/* setting mtu back and notifying everyone again,
+			 * so that they have a chance to revert changes.
+			 */
+			__dev_set_mtu(dev, orig_mtu);
+			call_netdevice_notifiers_mtu(NETDEV_CHANGEMTU, dev,
+						     new_mtu);
+		}
+	}
+	return err;
+}
+
+int dev_set_mtu(struct net_device *dev, int new_mtu)
+{
+	struct netlink_ext_ack extack;
+	int err;
+
+	memset(&extack, 0, sizeof(extack));
+	err = dev_set_mtu_ext(dev, new_mtu, &extack);
+	if (err && extack._msg)
+		net_err_ratelimited("%s: %s\n", dev->name, extack._msg);
+	return err;
+}
+EXPORT_SYMBOL(dev_set_mtu);
+
+/**
+ *	dev_change_tx_queue_len - Change TX queue length of a netdevice
+ *	@dev: device
+ *	@new_len: new tx queue length
+ */
+int dev_change_tx_queue_len(struct net_device *dev, unsigned long new_len)
+{
+	unsigned int orig_len = dev->tx_queue_len;
+	int res;
+
+	if (new_len != (unsigned int)new_len)
+		return -ERANGE;
+
+	if (new_len != orig_len) {
+		dev->tx_queue_len = new_len;
+		res = call_netdevice_notifiers(NETDEV_CHANGE_TX_QUEUE_LEN, dev);
+		res = notifier_to_errno(res);
+		if (res)
+			goto err_rollback;
+		res = dev_qdisc_change_tx_queue_len(dev);
+		if (res)
+			goto err_rollback;
+	}
+
+	return 0;
+
+err_rollback:
+	netdev_err(dev, "refused to change device tx_queue_len\n");
+	dev->tx_queue_len = orig_len;
+	return res;
+}
+
+/**
+ *	dev_set_group - Change group this device belongs to
+ *	@dev: device
+ *	@new_group: group this device should belong to
+ */
+void dev_set_group(struct net_device *dev, int new_group)
+{
+	dev->group = new_group;
+}
+EXPORT_SYMBOL(dev_set_group);
+
+/**
+ *	dev_pre_changeaddr_notify - Call NETDEV_PRE_CHANGEADDR.
+ *	@dev: device
+ *	@addr: new address
+ *	@extack: netlink extended ack
+ */
+int dev_pre_changeaddr_notify(struct net_device *dev, const char *addr,
+			      struct netlink_ext_ack *extack)
+{
+	struct netdev_notifier_pre_changeaddr_info info = {
+		.info.dev = dev,
+		.info.extack = extack,
+		.dev_addr = addr,
+	};
+	int rc;
+
+	rc = call_netdevice_notifiers_info(NETDEV_PRE_CHANGEADDR, &info.info);
+	return notifier_to_errno(rc);
+}
+EXPORT_SYMBOL(dev_pre_changeaddr_notify);
+
+/**
+ *	dev_set_mac_address - Change Media Access Control Address
+ *	@dev: device
+ *	@sa: new address
+ *	@extack: netlink extended ack
+ *
+ *	Change the hardware (MAC) address of the device
+ */
+int dev_set_mac_address(struct net_device *dev, struct sockaddr *sa,
+			struct netlink_ext_ack *extack)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+	int err;
+
+	if (!ops->ndo_set_mac_address)
+		return -EOPNOTSUPP;
+	if (sa->sa_family != dev->type)
+		return -EINVAL;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	err = dev_pre_changeaddr_notify(dev, sa->sa_data, extack);
+	if (err)
+		return err;
+	err = ops->ndo_set_mac_address(dev, sa);
+	if (err)
+		return err;
+	dev->addr_assign_type = NET_ADDR_SET;
+	call_netdevice_notifiers(NETDEV_CHANGEADDR, dev);
+	add_device_randomness(dev->dev_addr, dev->addr_len);
+	return 0;
+}
+EXPORT_SYMBOL(dev_set_mac_address);
+
+static DECLARE_RWSEM(dev_addr_sem);
+
+int dev_set_mac_address_user(struct net_device *dev, struct sockaddr *sa,
+			     struct netlink_ext_ack *extack)
+{
+	int ret;
+
+	down_write(&dev_addr_sem);
+	ret = dev_set_mac_address(dev, sa, extack);
+	up_write(&dev_addr_sem);
+	return ret;
+}
+EXPORT_SYMBOL(dev_set_mac_address_user);
+
+int dev_get_mac_address(struct sockaddr *sa, struct net *net, char *dev_name)
+{
+	size_t size = sizeof(sa->sa_data);
+	struct net_device *dev;
+	int ret = 0;
+
+	down_read(&dev_addr_sem);
+	rcu_read_lock();
+
+	dev = dev_get_by_name_rcu(net, dev_name);
+	if (!dev) {
+		ret = -ENODEV;
+		goto unlock;
+	}
+	if (!dev->addr_len)
+		memset(sa->sa_data, 0, size);
+	else
+		memcpy(sa->sa_data, dev->dev_addr,
+		       min_t(size_t, size, dev->addr_len));
+	sa->sa_family = dev->type;
+
+unlock:
+	rcu_read_unlock();
+	up_read(&dev_addr_sem);
+	return ret;
+}
+EXPORT_SYMBOL(dev_get_mac_address);
+
+/**
+ *	dev_change_carrier - Change device carrier
+ *	@dev: device
+ *	@new_carrier: new value
+ *
+ *	Change device carrier
+ */
+int dev_change_carrier(struct net_device *dev, bool new_carrier)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_carrier)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_carrier(dev, new_carrier);
+}
+EXPORT_SYMBOL(dev_change_carrier);
+
+/**
+ *	dev_get_phys_port_id - Get device physical port ID
+ *	@dev: device
+ *	@ppid: port ID
+ *
+ *	Get device physical port ID
+ */
+int dev_get_phys_port_id(struct net_device *dev,
+			 struct netdev_phys_item_id *ppid)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_get_phys_port_id)
+		return -EOPNOTSUPP;
+	return ops->ndo_get_phys_port_id(dev, ppid);
+}
+EXPORT_SYMBOL(dev_get_phys_port_id);
+
+/**
+ *	dev_get_phys_port_name - Get device physical port name
+ *	@dev: device
+ *	@name: port name
+ *	@len: limit of bytes to copy to name
+ *
+ *	Get device physical port name
+ */
+int dev_get_phys_port_name(struct net_device *dev,
+			   char *name, size_t len)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+	int err;
+
+	if (ops->ndo_get_phys_port_name) {
+		err = ops->ndo_get_phys_port_name(dev, name, len);
+		if (err != -EOPNOTSUPP)
+			return err;
+	}
+	return devlink_compat_phys_port_name_get(dev, name, len);
+}
+EXPORT_SYMBOL(dev_get_phys_port_name);
+
+/**
+ *	dev_get_port_parent_id - Get the device's port parent identifier
+ *	@dev: network device
+ *	@ppid: pointer to a storage for the port's parent identifier
+ *	@recurse: allow/disallow recursion to lower devices
+ *
+ *	Get the devices's port parent identifier
+ */
+int dev_get_port_parent_id(struct net_device *dev,
+			   struct netdev_phys_item_id *ppid,
+			   bool recurse)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+	struct netdev_phys_item_id first = { };
+	struct net_device *lower_dev;
+	struct list_head *iter;
+	int err;
+
+	if (ops->ndo_get_port_parent_id) {
+		err = ops->ndo_get_port_parent_id(dev, ppid);
+		if (err != -EOPNOTSUPP)
+			return err;
+	}
+
+	err = devlink_compat_switch_id_get(dev, ppid);
+	if (!err || err != -EOPNOTSUPP)
+		return err;
+
+	if (!recurse)
+		return -EOPNOTSUPP;
+
+	netdev_for_each_lower_dev(dev, lower_dev, iter) {
+		err = dev_get_port_parent_id(lower_dev, ppid, recurse);
+		if (err)
+			break;
+		if (!first.id_len)
+			first = *ppid;
+		else if (memcmp(&first, ppid, sizeof(*ppid)))
+			return -EOPNOTSUPP;
+	}
+
+	return err;
+}
+EXPORT_SYMBOL(dev_get_port_parent_id);
+
+/**
+ *	netdev_port_same_parent_id - Indicate if two network devices have
+ *	the same port parent identifier
+ *	@a: first network device
+ *	@b: second network device
+ */
+bool netdev_port_same_parent_id(struct net_device *a, struct net_device *b)
+{
+	struct netdev_phys_item_id a_id = { };
+	struct netdev_phys_item_id b_id = { };
+
+	if (dev_get_port_parent_id(a, &a_id, true) ||
+	    dev_get_port_parent_id(b, &b_id, true))
+		return false;
+
+	return netdev_phys_item_id_same(&a_id, &b_id);
+}
+EXPORT_SYMBOL(netdev_port_same_parent_id);
+
+/**
+ *	dev_change_proto_down - update protocol port state information
+ *	@dev: device
+ *	@proto_down: new value
+ *
+ *	This info can be used by switch drivers to set the phys state of the
+ *	port.
+ */
+int dev_change_proto_down(struct net_device *dev, bool proto_down)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (!ops->ndo_change_proto_down)
+		return -EOPNOTSUPP;
+	if (!netif_device_present(dev))
+		return -ENODEV;
+	return ops->ndo_change_proto_down(dev, proto_down);
+}
+EXPORT_SYMBOL(dev_change_proto_down);
+
+/**
+ *	dev_change_proto_down_generic - generic implementation for
+ * 	ndo_change_proto_down that sets carrier according to
+ * 	proto_down.
+ *
+ *	@dev: device
+ *	@proto_down: new value
+ */
+int dev_change_proto_down_generic(struct net_device *dev, bool proto_down)
+{
+	if (proto_down)
+		netif_carrier_off(dev);
+	else
+		netif_carrier_on(dev);
+	dev->proto_down = proto_down;
+	return 0;
+}
+EXPORT_SYMBOL(dev_change_proto_down_generic);
+
+/**
+ *	dev_change_proto_down_reason - proto down reason
+ *
+ *	@dev: device
+ *	@mask: proto down mask
+ *	@value: proto down value
+ */
+void dev_change_proto_down_reason(struct net_device *dev, unsigned long mask,
+				  u32 value)
+{
+	int b;
+
+	if (!mask) {
+		dev->proto_down_reason = value;
+	} else {
+		for_each_set_bit(b, &mask, 32) {
+			if (value & (1 << b))
+				dev->proto_down_reason |= BIT(b);
+			else
+				dev->proto_down_reason &= ~BIT(b);
+		}
+	}
+}
+EXPORT_SYMBOL(dev_change_proto_down_reason);
+
+struct bpf_xdp_link {
+	struct bpf_link link;
+	struct net_device *dev; /* protected by rtnl_lock, no refcnt held */
+	int flags;
+};
+
+static enum bpf_xdp_mode dev_xdp_mode(struct net_device *dev, u32 flags)
+{
+	if (flags & XDP_FLAGS_HW_MODE)
+		return XDP_MODE_HW;
+	if (flags & XDP_FLAGS_DRV_MODE)
+		return XDP_MODE_DRV;
+	if (flags & XDP_FLAGS_SKB_MODE)
+		return XDP_MODE_SKB;
+	return dev->netdev_ops->ndo_bpf ? XDP_MODE_DRV : XDP_MODE_SKB;
+}
+
+static bpf_op_t dev_xdp_bpf_op(struct net_device *dev, enum bpf_xdp_mode mode)
+{
+	switch (mode) {
+	case XDP_MODE_SKB:
+		return generic_xdp_install;
+	case XDP_MODE_DRV:
+	case XDP_MODE_HW:
+		return dev->netdev_ops->ndo_bpf;
+	default:
+		return NULL;
+	};
+}
+
+static struct bpf_xdp_link *dev_xdp_link(struct net_device *dev,
+					 enum bpf_xdp_mode mode)
+{
+	return dev->xdp_state[mode].link;
+}
+
+static struct bpf_prog *dev_xdp_prog(struct net_device *dev,
+				     enum bpf_xdp_mode mode)
+{
+	struct bpf_xdp_link *link = dev_xdp_link(dev, mode);
+
+	if (link)
+		return link->link.prog;
+	return dev->xdp_state[mode].prog;
+}
+
+static u8 dev_xdp_prog_count(struct net_device *dev)
+{
+	u8 count = 0;
+	int i;
+
+	for (i = 0; i < __MAX_XDP_MODE; i++)
+		if (dev->xdp_state[i].prog || dev->xdp_state[i].link)
+			count++;
+	return count;
+}
+
+u32 dev_xdp_prog_id(struct net_device *dev, enum bpf_xdp_mode mode)
+{
+	struct bpf_prog *prog = dev_xdp_prog(dev, mode);
+
+	return prog ? prog->aux->id : 0;
+}
+
+static void dev_xdp_set_link(struct net_device *dev, enum bpf_xdp_mode mode,
+			     struct bpf_xdp_link *link)
+{
+	dev->xdp_state[mode].link = link;
+	dev->xdp_state[mode].prog = NULL;
+}
+
+static void dev_xdp_set_prog(struct net_device *dev, enum bpf_xdp_mode mode,
+			     struct bpf_prog *prog)
+{
+	dev->xdp_state[mode].link = NULL;
+	dev->xdp_state[mode].prog = prog;
+}
+
+static int dev_xdp_install(struct net_device *dev, enum bpf_xdp_mode mode,
+			   bpf_op_t bpf_op, struct netlink_ext_ack *extack,
+			   u32 flags, struct bpf_prog *prog)
+{
+	struct netdev_bpf xdp;
+	int err;
+
+	memset(&xdp, 0, sizeof(xdp));
+	xdp.command = mode == XDP_MODE_HW ? XDP_SETUP_PROG_HW : XDP_SETUP_PROG;
+	xdp.extack = extack;
+	xdp.flags = flags;
+	xdp.prog = prog;
+
+	/* Drivers assume refcnt is already incremented (i.e, prog pointer is
+	 * "moved" into driver), so they don't increment it on their own, but
+	 * they do decrement refcnt when program is detached or replaced.
+	 * Given net_device also owns link/prog, we need to bump refcnt here
+	 * to prevent drivers from underflowing it.
+	 */
+	if (prog)
+		bpf_prog_inc(prog);
+	err = bpf_op(dev, &xdp);
+	if (err) {
+		if (prog)
+			bpf_prog_put(prog);
+		return err;
+	}
+
+	if (mode != XDP_MODE_HW)
+		bpf_prog_change_xdp(dev_xdp_prog(dev, mode), prog);
+
+	return 0;
+}
+
+static void dev_xdp_uninstall(struct net_device *dev)
+{
+	struct bpf_xdp_link *link;
+	struct bpf_prog *prog;
+	enum bpf_xdp_mode mode;
+	bpf_op_t bpf_op;
+
+	ASSERT_RTNL();
+
+	for (mode = XDP_MODE_SKB; mode < __MAX_XDP_MODE; mode++) {
+		prog = dev_xdp_prog(dev, mode);
+		if (!prog)
+			continue;
+
+		bpf_op = dev_xdp_bpf_op(dev, mode);
+		if (!bpf_op)
+			continue;
+
+		WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
+
+		/* auto-detach link from net device */
+		link = dev_xdp_link(dev, mode);
+		if (link)
+			link->dev = NULL;
+		else
+			bpf_prog_put(prog);
+
+		dev_xdp_set_link(dev, mode, NULL);
+	}
+}
+
+static int dev_xdp_attach(struct net_device *dev, struct netlink_ext_ack *extack,
+			  struct bpf_xdp_link *link, struct bpf_prog *new_prog,
+			  struct bpf_prog *old_prog, u32 flags)
+{
+	unsigned int num_modes = hweight32(flags & XDP_FLAGS_MODES);
+	struct bpf_prog *cur_prog;
+	enum bpf_xdp_mode mode;
+	bpf_op_t bpf_op;
+	int err;
+
+	ASSERT_RTNL();
+
+	/* either link or prog attachment, never both */
+	if (link && (new_prog || old_prog))
+		return -EINVAL;
+	/* link supports only XDP mode flags */
+	if (link && (flags & ~XDP_FLAGS_MODES)) {
+		NL_SET_ERR_MSG(extack, "Invalid XDP flags for BPF link attachment");
+		return -EINVAL;
+	}
+	/* just one XDP mode bit should be set, zero defaults to drv/skb mode */
+	if (num_modes > 1) {
+		NL_SET_ERR_MSG(extack, "Only one XDP mode flag can be set");
+		return -EINVAL;
+	}
+	/* avoid ambiguity if offload + drv/skb mode progs are both loaded */
+	if (!num_modes && dev_xdp_prog_count(dev) > 1) {
+		NL_SET_ERR_MSG(extack,
+			       "More than one program loaded, unset mode is ambiguous");
+		return -EINVAL;
+	}
+	/* old_prog != NULL implies XDP_FLAGS_REPLACE is set */
+	if (old_prog && !(flags & XDP_FLAGS_REPLACE)) {
+		NL_SET_ERR_MSG(extack, "XDP_FLAGS_REPLACE is not specified");
+		return -EINVAL;
+	}
+
+	mode = dev_xdp_mode(dev, flags);
+	/* can't replace attached link */
+	if (dev_xdp_link(dev, mode)) {
+		NL_SET_ERR_MSG(extack, "Can't replace active BPF XDP link");
+		return -EBUSY;
+	}
+
+	cur_prog = dev_xdp_prog(dev, mode);
+	/* can't replace attached prog with link */
+	if (link && cur_prog) {
+		NL_SET_ERR_MSG(extack, "Can't replace active XDP program with BPF link");
+		return -EBUSY;
+	}
+	if ((flags & XDP_FLAGS_REPLACE) && cur_prog != old_prog) {
+		NL_SET_ERR_MSG(extack, "Active program does not match expected");
+		return -EEXIST;
+	}
+
+	/* put effective new program into new_prog */
+	if (link)
+		new_prog = link->link.prog;
+
+	if (new_prog) {
+		bool offload = mode == XDP_MODE_HW;
+		enum bpf_xdp_mode other_mode = mode == XDP_MODE_SKB
+					       ? XDP_MODE_DRV : XDP_MODE_SKB;
+
+		if ((flags & XDP_FLAGS_UPDATE_IF_NOEXIST) && cur_prog) {
+			NL_SET_ERR_MSG(extack, "XDP program already attached");
+			return -EBUSY;
+		}
+		if (!offload && dev_xdp_prog(dev, other_mode)) {
+			NL_SET_ERR_MSG(extack, "Native and generic XDP can't be active at the same time");
+			return -EEXIST;
+		}
+		if (!offload && bpf_prog_is_dev_bound(new_prog->aux)) {
+			NL_SET_ERR_MSG(extack, "Using device-bound program without HW_MODE flag is not supported");
+			return -EINVAL;
+		}
+		if (new_prog->expected_attach_type == BPF_XDP_DEVMAP) {
+			NL_SET_ERR_MSG(extack, "BPF_XDP_DEVMAP programs can not be attached to a device");
+			return -EINVAL;
+		}
+		if (new_prog->expected_attach_type == BPF_XDP_CPUMAP) {
+			NL_SET_ERR_MSG(extack, "BPF_XDP_CPUMAP programs can not be attached to a device");
+			return -EINVAL;
+		}
+	}
+
+	/* don't call drivers if the effective program didn't change */
+	if (new_prog != cur_prog) {
+		bpf_op = dev_xdp_bpf_op(dev, mode);
+		if (!bpf_op) {
+			NL_SET_ERR_MSG(extack, "Underlying driver does not support XDP in native mode");
+			return -EOPNOTSUPP;
+		}
+
+		err = dev_xdp_install(dev, mode, bpf_op, extack, flags, new_prog);
+		if (err)
+			return err;
+	}
+
+	if (link)
+		dev_xdp_set_link(dev, mode, link);
+	else
+		dev_xdp_set_prog(dev, mode, new_prog);
+	if (cur_prog)
+		bpf_prog_put(cur_prog);
+
+	return 0;
+}
+
+static int dev_xdp_attach_link(struct net_device *dev,
+			       struct netlink_ext_ack *extack,
+			       struct bpf_xdp_link *link)
+{
+	return dev_xdp_attach(dev, extack, link, NULL, NULL, link->flags);
+}
+
+static int dev_xdp_detach_link(struct net_device *dev,
+			       struct netlink_ext_ack *extack,
+			       struct bpf_xdp_link *link)
+{
+	enum bpf_xdp_mode mode;
+	bpf_op_t bpf_op;
+
+	ASSERT_RTNL();
+
+	mode = dev_xdp_mode(dev, link->flags);
+	if (dev_xdp_link(dev, mode) != link)
+		return -EINVAL;
+
+	bpf_op = dev_xdp_bpf_op(dev, mode);
+	WARN_ON(dev_xdp_install(dev, mode, bpf_op, NULL, 0, NULL));
+	dev_xdp_set_link(dev, mode, NULL);
+	return 0;
+}
+
+static void bpf_xdp_link_release(struct bpf_link *link)
+{
+	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
+
+	rtnl_lock();
+
+	/* if racing with net_device's tear down, xdp_link->dev might be
+	 * already NULL, in which case link was already auto-detached
+	 */
+	if (xdp_link->dev) {
+		WARN_ON(dev_xdp_detach_link(xdp_link->dev, NULL, xdp_link));
+		xdp_link->dev = NULL;
+	}
+
+	rtnl_unlock();
+}
+
+static int bpf_xdp_link_detach(struct bpf_link *link)
+{
+	bpf_xdp_link_release(link);
+	return 0;
+}
+
+static void bpf_xdp_link_dealloc(struct bpf_link *link)
+{
+	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
+
+	kfree(xdp_link);
+}
+
+static void bpf_xdp_link_show_fdinfo(const struct bpf_link *link,
+				     struct seq_file *seq)
+{
+	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
+	u32 ifindex = 0;
+
+	rtnl_lock();
+	if (xdp_link->dev)
+		ifindex = xdp_link->dev->ifindex;
+	rtnl_unlock();
+
+	seq_printf(seq, "ifindex:\t%u\n", ifindex);
+}
+
+static int bpf_xdp_link_fill_link_info(const struct bpf_link *link,
+				       struct bpf_link_info *info)
+{
+	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
+	u32 ifindex = 0;
+
+	rtnl_lock();
+	if (xdp_link->dev)
+		ifindex = xdp_link->dev->ifindex;
+	rtnl_unlock();
+
+	info->xdp.ifindex = ifindex;
+	return 0;
+}
+
+static int bpf_xdp_link_update(struct bpf_link *link, struct bpf_prog *new_prog,
+			       struct bpf_prog *old_prog)
+{
+	struct bpf_xdp_link *xdp_link = container_of(link, struct bpf_xdp_link, link);
+	enum bpf_xdp_mode mode;
+	bpf_op_t bpf_op;
+	int err = 0;
+
+	rtnl_lock();
+
+	/* link might have been auto-released already, so fail */
+	if (!xdp_link->dev) {
+		err = -ENOLINK;
+		goto out_unlock;
+	}
+
+	if (old_prog && link->prog != old_prog) {
+		err = -EPERM;
+		goto out_unlock;
+	}
+	old_prog = link->prog;
+	if (old_prog->type != new_prog->type ||
+	    old_prog->expected_attach_type != new_prog->expected_attach_type) {
+		err = -EINVAL;
+		goto out_unlock;
+	}
+
+	if (old_prog == new_prog) {
+		/* no-op, don't disturb drivers */
+		bpf_prog_put(new_prog);
+		goto out_unlock;
+	}
+
+	mode = dev_xdp_mode(xdp_link->dev, xdp_link->flags);
+	bpf_op = dev_xdp_bpf_op(xdp_link->dev, mode);
+	err = dev_xdp_install(xdp_link->dev, mode, bpf_op, NULL,
+			      xdp_link->flags, new_prog);
+	if (err)
+		goto out_unlock;
+
+	old_prog = xchg(&link->prog, new_prog);
+	bpf_prog_put(old_prog);
+
+out_unlock:
+	rtnl_unlock();
+	return err;
+}
+
+static const struct bpf_link_ops bpf_xdp_link_lops = {
+	.release = bpf_xdp_link_release,
+	.dealloc = bpf_xdp_link_dealloc,
+	.detach = bpf_xdp_link_detach,
+	.show_fdinfo = bpf_xdp_link_show_fdinfo,
+	.fill_link_info = bpf_xdp_link_fill_link_info,
+	.update_prog = bpf_xdp_link_update,
+};
+
+int bpf_xdp_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
+{
+	struct net *net = current->nsproxy->net_ns;
+	struct bpf_link_primer link_primer;
+	struct bpf_xdp_link *link;
+	struct net_device *dev;
+	int err, fd;
+
+	rtnl_lock();
+	dev = dev_get_by_index(net, attr->link_create.target_ifindex);
+	if (!dev) {
+		rtnl_unlock();
+		return -EINVAL;
+	}
+
+	link = kzalloc(sizeof(*link), GFP_USER);
+	if (!link) {
+		err = -ENOMEM;
+		goto unlock;
+	}
+
+	bpf_link_init(&link->link, BPF_LINK_TYPE_XDP, &bpf_xdp_link_lops, prog);
+	link->dev = dev;
+	link->flags = attr->link_create.flags;
+
+	err = bpf_link_prime(&link->link, &link_primer);
+	if (err) {
+		kfree(link);
+		goto unlock;
+	}
+
+	err = dev_xdp_attach_link(dev, NULL, link);
+	rtnl_unlock();
+
+	if (err) {
+		link->dev = NULL;
+		bpf_link_cleanup(&link_primer);
+		goto out_put_dev;
+	}
+
+	fd = bpf_link_settle(&link_primer);
+	/* link itself doesn't hold dev's refcnt to not complicate shutdown */
+	dev_put(dev);
+	return fd;
+
+unlock:
+	rtnl_unlock();
+
+out_put_dev:
+	dev_put(dev);
+	return err;
+}
+
+/**
+ *	dev_change_xdp_fd - set or clear a bpf program for a device rx path
+ *	@dev: device
+ *	@extack: netlink extended ack
+ *	@fd: new program fd or negative value to clear
+ *	@expected_fd: old program fd that userspace expects to replace or clear
+ *	@flags: xdp-related flags
+ *
+ *	Set or clear a bpf program for a device
+ */
+int dev_change_xdp_fd(struct net_device *dev, struct netlink_ext_ack *extack,
+		      int fd, int expected_fd, u32 flags)
+{
+	enum bpf_xdp_mode mode = dev_xdp_mode(dev, flags);
+	struct bpf_prog *new_prog = NULL, *old_prog = NULL;
+	int err;
+
+	ASSERT_RTNL();
+
+	if (fd >= 0) {
+		new_prog = bpf_prog_get_type_dev(fd, BPF_PROG_TYPE_XDP,
+						 mode != XDP_MODE_SKB);
+		if (IS_ERR(new_prog))
+			return PTR_ERR(new_prog);
+	}
+
+	if (expected_fd >= 0) {
+		old_prog = bpf_prog_get_type_dev(expected_fd, BPF_PROG_TYPE_XDP,
+						 mode != XDP_MODE_SKB);
+		if (IS_ERR(old_prog)) {
+			err = PTR_ERR(old_prog);
+			old_prog = NULL;
+			goto err_out;
+		}
+	}
+
+	err = dev_xdp_attach(dev, extack, NULL, new_prog, old_prog, flags);
+
+err_out:
+	if (err && new_prog)
+		bpf_prog_put(new_prog);
+	if (old_prog)
+		bpf_prog_put(old_prog);
+	return err;
+}
+
+/**
+ *	dev_new_index	-	allocate an ifindex
+ *	@net: the applicable net namespace
+ *
+ *	Returns a suitable unique value for a new device interface
+ *	number.  The caller must hold the rtnl semaphore or the
+ *	dev_base_lock to be sure it remains unique.
+ */
+static int dev_new_index(struct net *net)
+{
+	int ifindex = net->ifindex;
+
+	for (;;) {
+		if (++ifindex <= 0)
+			ifindex = 1;
+		if (!__dev_get_by_index(net, ifindex))
+			return net->ifindex = ifindex;
+	}
+}
+
+/* Delayed registration/unregisteration */
+static LIST_HEAD(net_todo_list);
+DECLARE_WAIT_QUEUE_HEAD(netdev_unregistering_wq);
+
+static void net_set_todo(struct net_device *dev)
+{
+	list_add_tail(&dev->todo_list, &net_todo_list);
+	dev_net(dev)->dev_unreg_count++;
+}
+
+static netdev_features_t netdev_sync_upper_features(struct net_device *lower,
+	struct net_device *upper, netdev_features_t features)
+{
+	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
+	netdev_features_t feature;
+	int feature_bit;
+
+	for_each_netdev_feature(upper_disables, feature_bit) {
+		feature = __NETIF_F_BIT(feature_bit);
+		if (!(upper->wanted_features & feature)
+		    && (features & feature)) {
+			netdev_dbg(lower, "Dropping feature %pNF, upper dev %s has it off.\n",
+				   &feature, upper->name);
+			features &= ~feature;
+		}
+	}
+
+	return features;
+}
+
+static void netdev_sync_lower_features(struct net_device *upper,
+	struct net_device *lower, netdev_features_t features)
+{
+	netdev_features_t upper_disables = NETIF_F_UPPER_DISABLES;
+	netdev_features_t feature;
+	int feature_bit;
+
+	for_each_netdev_feature(upper_disables, feature_bit) {
+		feature = __NETIF_F_BIT(feature_bit);
+		if (!(features & feature) && (lower->features & feature)) {
+			netdev_dbg(upper, "Disabling feature %pNF on lower dev %s.\n",
+				   &feature, lower->name);
+			lower->wanted_features &= ~feature;
+			__netdev_update_features(lower);
+
+			if (unlikely(lower->features & feature))
+				netdev_WARN(upper, "failed to disable %pNF on %s!\n",
+					    &feature, lower->name);
+			else
+				netdev_features_change(lower);
+		}
+	}
+}
+
+static netdev_features_t netdev_fix_features(struct net_device *dev,
+	netdev_features_t features)
+{
+	/* Fix illegal checksum combinations */
+	if ((features & NETIF_F_HW_CSUM) &&
+	    (features & (NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM))) {
+		netdev_warn(dev, "mixed HW and IP checksum settings.\n");
+		features &= ~(NETIF_F_IP_CSUM|NETIF_F_IPV6_CSUM);
+	}
+
+	/* TSO requires that SG is present as well. */
+	if ((features & NETIF_F_ALL_TSO) && !(features & NETIF_F_SG)) {
+		netdev_dbg(dev, "Dropping TSO features since no SG feature.\n");
+		features &= ~NETIF_F_ALL_TSO;
+	}
+
+	if ((features & NETIF_F_TSO) && !(features & NETIF_F_HW_CSUM) &&
+					!(features & NETIF_F_IP_CSUM)) {
+		netdev_dbg(dev, "Dropping TSO features since no CSUM feature.\n");
+		features &= ~NETIF_F_TSO;
+		features &= ~NETIF_F_TSO_ECN;
+	}
+
+	if ((features & NETIF_F_TSO6) && !(features & NETIF_F_HW_CSUM) &&
+					 !(features & NETIF_F_IPV6_CSUM)) {
+		netdev_dbg(dev, "Dropping TSO6 features since no CSUM feature.\n");
+		features &= ~NETIF_F_TSO6;
+	}
+
+	/* TSO with IPv4 ID mangling requires IPv4 TSO be enabled */
+	if ((features & NETIF_F_TSO_MANGLEID) && !(features & NETIF_F_TSO))
+		features &= ~NETIF_F_TSO_MANGLEID;
+
+	/* TSO ECN requires that TSO is present as well. */
+	if ((features & NETIF_F_ALL_TSO) == NETIF_F_TSO_ECN)
+		features &= ~NETIF_F_TSO_ECN;
+
+	/* Software GSO depends on SG. */
+	if ((features & NETIF_F_GSO) && !(features & NETIF_F_SG)) {
+		netdev_dbg(dev, "Dropping NETIF_F_GSO since no SG feature.\n");
+		features &= ~NETIF_F_GSO;
+	}
+
+	/* GSO partial features require GSO partial be set */
+	if ((features & dev->gso_partial_features) &&
+	    !(features & NETIF_F_GSO_PARTIAL)) {
+		netdev_dbg(dev,
+			   "Dropping partially supported GSO features since no GSO partial.\n");
+		features &= ~dev->gso_partial_features;
+	}
+
+	if (!(features & NETIF_F_RXCSUM)) {
+		/* NETIF_F_GRO_HW implies doing RXCSUM since every packet
+		 * successfully merged by hardware must also have the
+		 * checksum verified by hardware.  If the user does not
+		 * want to enable RXCSUM, logically, we should disable GRO_HW.
+		 */
+		if (features & NETIF_F_GRO_HW) {
+			netdev_dbg(dev, "Dropping NETIF_F_GRO_HW since no RXCSUM feature.\n");
+			features &= ~NETIF_F_GRO_HW;
+		}
+	}
+
+	/* LRO/HW-GRO features cannot be combined with RX-FCS */
+	if (features & NETIF_F_RXFCS) {
+		if (features & NETIF_F_LRO) {
+			netdev_dbg(dev, "Dropping LRO feature since RX-FCS is requested.\n");
+			features &= ~NETIF_F_LRO;
+		}
+
+		if (features & NETIF_F_GRO_HW) {
+			netdev_dbg(dev, "Dropping HW-GRO feature since RX-FCS is requested.\n");
+			features &= ~NETIF_F_GRO_HW;
+		}
+	}
+
+	if ((features & NETIF_F_HW_TLS_RX) && !(features & NETIF_F_RXCSUM)) {
+		netdev_dbg(dev, "Dropping TLS RX HW offload feature since no RXCSUM feature.\n");
+		features &= ~NETIF_F_HW_TLS_RX;
+	}
+
+	return features;
+}
+
+int __netdev_update_features(struct net_device *dev)
+{
+	struct net_device *upper, *lower;
+	netdev_features_t features;
+	struct list_head *iter;
+	int err = -1;
+
+	ASSERT_RTNL();
+
+	features = netdev_get_wanted_features(dev);
+
+	if (dev->netdev_ops->ndo_fix_features)
+		features = dev->netdev_ops->ndo_fix_features(dev, features);
+
+	/* driver might be less strict about feature dependencies */
+	features = netdev_fix_features(dev, features);
+
+	/* some features can't be enabled if they're off on an upper device */
+	netdev_for_each_upper_dev_rcu(dev, upper, iter)
+		features = netdev_sync_upper_features(dev, upper, features);
+
+	if (dev->features == features)
+		goto sync_lower;
+
+	netdev_dbg(dev, "Features changed: %pNF -> %pNF\n",
+		&dev->features, &features);
+
+	if (dev->netdev_ops->ndo_set_features)
+		err = dev->netdev_ops->ndo_set_features(dev, features);
+	else
+		err = 0;
+
+	if (unlikely(err < 0)) {
+		netdev_err(dev,
+			"set_features() failed (%d); wanted %pNF, left %pNF\n",
+			err, &features, &dev->features);
+		/* return non-0 since some features might have changed and
+		 * it's better to fire a spurious notification than miss it
+		 */
+		return -1;
+	}
+
+sync_lower:
+	/* some features must be disabled on lower devices when disabled
+	 * on an upper device (think: bonding master or bridge)
+	 */
+	netdev_for_each_lower_dev(dev, lower, iter)
+		netdev_sync_lower_features(dev, lower, features);
+
+	if (!err) {
+		netdev_features_t diff = features ^ dev->features;
+
+		if (diff & NETIF_F_RX_UDP_TUNNEL_PORT) {
+			/* udp_tunnel_{get,drop}_rx_info both need
+			 * NETIF_F_RX_UDP_TUNNEL_PORT enabled on the
+			 * device, or they won't do anything.
+			 * Thus we need to update dev->features
+			 * *before* calling udp_tunnel_get_rx_info,
+			 * but *after* calling udp_tunnel_drop_rx_info.
+			 */
+			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
+				dev->features = features;
+				udp_tunnel_get_rx_info(dev);
+			} else {
+				udp_tunnel_drop_rx_info(dev);
+			}
+		}
+
+		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {
+			if (features & NETIF_F_HW_VLAN_CTAG_FILTER) {
+				dev->features = features;
+				err |= vlan_get_rx_ctag_filter_info(dev);
+			} else {
+				vlan_drop_rx_ctag_filter_info(dev);
+			}
+		}
+
+		if (diff & NETIF_F_HW_VLAN_STAG_FILTER) {
+			if (features & NETIF_F_HW_VLAN_STAG_FILTER) {
+				dev->features = features;
+				err |= vlan_get_rx_stag_filter_info(dev);
+			} else {
+				vlan_drop_rx_stag_filter_info(dev);
+			}
+		}
+
+		dev->features = features;
+	}
+
+	return err < 0 ? 0 : 1;
+}
+
+/**
+ *	netdev_update_features - recalculate device features
+ *	@dev: the device to check
+ *
+ *	Recalculate dev->features set and send notifications if it
+ *	has changed. Should be called after driver or hardware dependent
+ *	conditions might have changed that influence the features.
+ */
+void netdev_update_features(struct net_device *dev)
+{
+	if (__netdev_update_features(dev))
+		netdev_features_change(dev);
+}
+EXPORT_SYMBOL(netdev_update_features);
+
+/**
+ *	netdev_change_features - recalculate device features
+ *	@dev: the device to check
+ *
+ *	Recalculate dev->features set and send notifications even
+ *	if they have not changed. Should be called instead of
+ *	netdev_update_features() if also dev->vlan_features might
+ *	have changed to allow the changes to be propagated to stacked
+ *	VLAN devices.
+ */
+void netdev_change_features(struct net_device *dev)
+{
+	__netdev_update_features(dev);
+	netdev_features_change(dev);
+}
+EXPORT_SYMBOL(netdev_change_features);
+
+/**
+ *	netif_stacked_transfer_operstate -	transfer operstate
+ *	@rootdev: the root or lower level device to transfer state from
+ *	@dev: the device to transfer operstate to
+ *
+ *	Transfer operational state from root to device. This is normally
+ *	called when a stacking relationship exists between the root
+ *	device and the device(a leaf device).
+ */
+void netif_stacked_transfer_operstate(const struct net_device *rootdev,
+					struct net_device *dev)
+{
+	if (rootdev->operstate == IF_OPER_DORMANT)
+		netif_dormant_on(dev);
+	else
+		netif_dormant_off(dev);
+
+	if (rootdev->operstate == IF_OPER_TESTING)
+		netif_testing_on(dev);
+	else
+		netif_testing_off(dev);
+
+	if (netif_carrier_ok(rootdev))
+		netif_carrier_on(dev);
+	else
+		netif_carrier_off(dev);
+}
+EXPORT_SYMBOL(netif_stacked_transfer_operstate);
+
+static int netif_alloc_rx_queues(struct net_device *dev)
+{
+	unsigned int i, count = dev->num_rx_queues;
+	struct netdev_rx_queue *rx;
+	size_t sz = count * sizeof(*rx);
+	int err = 0;
+
+	BUG_ON(count < 1);
+
+	rx = kvzalloc(sz, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+	if (!rx)
+		return -ENOMEM;
+
+	dev->_rx = rx;
+
+	for (i = 0; i < count; i++) {
+		rx[i].dev = dev;
+
+		/* XDP RX-queue setup */
+		err = xdp_rxq_info_reg(&rx[i].xdp_rxq, dev, i);
+		if (err < 0)
+			goto err_rxq_info;
+	}
+	return 0;
+
+err_rxq_info:
+	/* Rollback successful reg's and free other resources */
+	while (i--)
+		xdp_rxq_info_unreg(&rx[i].xdp_rxq);
+	kvfree(dev->_rx);
+	dev->_rx = NULL;
+	return err;
+}
+
+static void netif_free_rx_queues(struct net_device *dev)
+{
+	unsigned int i, count = dev->num_rx_queues;
+
+	/* netif_alloc_rx_queues alloc failed, resources have been unreg'ed */
+	if (!dev->_rx)
+		return;
+
+	for (i = 0; i < count; i++)
+		xdp_rxq_info_unreg(&dev->_rx[i].xdp_rxq);
+
+	kvfree(dev->_rx);
+}
+
+static void netdev_init_one_queue(struct net_device *dev,
+				  struct netdev_queue *queue, void *_unused)
+{
+	/* Initialize queue lock */
+	spin_lock_init(&queue->_xmit_lock);
+	netdev_set_xmit_lockdep_class(&queue->_xmit_lock, dev->type);
+	queue->xmit_lock_owner = -1;
+	netdev_queue_numa_node_write(queue, NUMA_NO_NODE);
+	queue->dev = dev;
+#ifdef CONFIG_BQL
+	dql_init(&queue->dql, HZ);
+#endif
+}
+
+static void netif_free_tx_queues(struct net_device *dev)
+{
+	kvfree(dev->_tx);
+}
+
+static int netif_alloc_netdev_queues(struct net_device *dev)
+{
+	unsigned int count = dev->num_tx_queues;
+	struct netdev_queue *tx;
+	size_t sz = count * sizeof(*tx);
+
+	if (count < 1 || count > 0xffff)
+		return -EINVAL;
+
+	tx = kvzalloc(sz, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+	if (!tx)
+		return -ENOMEM;
+
+	dev->_tx = tx;
+
+	netdev_for_each_tx_queue(dev, netdev_init_one_queue, NULL);
+	spin_lock_init(&dev->tx_global_lock);
+
+	return 0;
+}
+
+void netif_tx_stop_all_queues(struct net_device *dev)
+{
+	unsigned int i;
+
+	for (i = 0; i < dev->num_tx_queues; i++) {
+		struct netdev_queue *txq = netdev_get_tx_queue(dev, i);
+
+		netif_tx_stop_queue(txq);
+	}
+}
+EXPORT_SYMBOL(netif_tx_stop_all_queues);
+
+/**
+ *	register_netdevice	- register a network device
+ *	@dev: device to register
+ *
+ *	Take a completed network device structure and add it to the kernel
+ *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
+ *	chain. 0 is returned on success. A negative errno code is returned
+ *	on a failure to set up the device, or if the name is a duplicate.
+ *
+ *	Callers must hold the rtnl semaphore. You may want
+ *	register_netdev() instead of this.
+ *
+ *	BUGS:
+ *	The locking appears insufficient to guarantee two parallel registers
+ *	will not get the same name.
+ */
+
+int register_netdevice(struct net_device *dev)
+{
+	int ret;
+	struct net *net = dev_net(dev);
+
+	BUILD_BUG_ON(sizeof(netdev_features_t) * BITS_PER_BYTE <
+		     NETDEV_FEATURE_COUNT);
+	BUG_ON(dev_boot_phase);
+	ASSERT_RTNL();
+
+	might_sleep();
+
+	/* When net_device's are persistent, this will be fatal. */
+	BUG_ON(dev->reg_state != NETREG_UNINITIALIZED);
+	BUG_ON(!net);
+
+	ret = ethtool_check_ops(dev->ethtool_ops);
+	if (ret)
+		return ret;
+
+	spin_lock_init(&dev->addr_list_lock);
+	netdev_set_addr_lockdep_class(dev);
+
+	ret = dev_get_valid_name(net, dev, dev->name);
+	if (ret < 0)
+		goto out;
+
+	ret = -ENOMEM;
+	dev->name_node = netdev_name_node_head_alloc(dev);
+	if (!dev->name_node)
+		goto out;
+
+	/* Init, if this function is available */
+	if (dev->netdev_ops->ndo_init) {
+		ret = dev->netdev_ops->ndo_init(dev);
+		if (ret) {
+			if (ret > 0)
+				ret = -EIO;
+			goto err_free_name;
+		}
+	}
+
+	if (((dev->hw_features | dev->features) &
+	     NETIF_F_HW_VLAN_CTAG_FILTER) &&
+	    (!dev->netdev_ops->ndo_vlan_rx_add_vid ||
+	     !dev->netdev_ops->ndo_vlan_rx_kill_vid)) {
+		netdev_WARN(dev, "Buggy VLAN acceleration in driver!\n");
+		ret = -EINVAL;
+		goto err_uninit;
+	}
+
+	ret = -EBUSY;
+	if (!dev->ifindex)
+		dev->ifindex = dev_new_index(net);
+	else if (__dev_get_by_index(net, dev->ifindex))
+		goto err_uninit;
+
+	/* Transfer changeable features to wanted_features and enable
+	 * software offloads (GSO and GRO).
+	 */
+	dev->hw_features |= (NETIF_F_SOFT_FEATURES | NETIF_F_SOFT_FEATURES_OFF);
+	dev->features |= NETIF_F_SOFT_FEATURES;
+
+	if (dev->netdev_ops->ndo_udp_tunnel_add) {
+		dev->features |= NETIF_F_RX_UDP_TUNNEL_PORT;
+		dev->hw_features |= NETIF_F_RX_UDP_TUNNEL_PORT;
+	}
+
+	dev->wanted_features = dev->features & dev->hw_features;
+
+	if (!(dev->flags & IFF_LOOPBACK))
+		dev->hw_features |= NETIF_F_NOCACHE_COPY;
+
+	/* If IPv4 TCP segmentation offload is supported we should also
+	 * allow the device to enable segmenting the frame with the option
+	 * of ignoring a static IP ID value.  This doesn't enable the
+	 * feature itself but allows the user to enable it later.
+	 */
+	if (dev->hw_features & NETIF_F_TSO)
+		dev->hw_features |= NETIF_F_TSO_MANGLEID;
+	if (dev->vlan_features & NETIF_F_TSO)
+		dev->vlan_features |= NETIF_F_TSO_MANGLEID;
+	if (dev->mpls_features & NETIF_F_TSO)
+		dev->mpls_features |= NETIF_F_TSO_MANGLEID;
+	if (dev->hw_enc_features & NETIF_F_TSO)
+		dev->hw_enc_features |= NETIF_F_TSO_MANGLEID;
+
+	/* Make NETIF_F_HIGHDMA inheritable to VLAN devices.
+	 */
+	dev->vlan_features |= NETIF_F_HIGHDMA;
+
+	/* Make NETIF_F_SG inheritable to tunnel devices.
+	 */
+	dev->hw_enc_features |= NETIF_F_SG | NETIF_F_GSO_PARTIAL;
+
+	/* Make NETIF_F_SG inheritable to MPLS.
+	 */
+	dev->mpls_features |= NETIF_F_SG;
+
+	ret = call_netdevice_notifiers(NETDEV_POST_INIT, dev);
+	ret = notifier_to_errno(ret);
+	if (ret)
+		goto err_uninit;
+
+	ret = netdev_register_kobject(dev);
+	if (ret) {
+		dev->reg_state = NETREG_UNREGISTERED;
+		goto err_uninit;
+	}
+	dev->reg_state = NETREG_REGISTERED;
+
+	__netdev_update_features(dev);
+
+	/*
+	 *	Default initial state at registry is that the
+	 *	device is present.
+	 */
+
+	set_bit(__LINK_STATE_PRESENT, &dev->state);
+
+	linkwatch_init_dev(dev);
+
+	dev_init_scheduler(dev);
+	dev_hold(dev);
+	list_netdevice(dev);
+	add_device_randomness(dev->dev_addr, dev->addr_len);
+
+	/* If the device has permanent device address, driver should
+	 * set dev_addr and also addr_assign_type should be set to
+	 * NET_ADDR_PERM (default value).
+	 */
+	if (dev->addr_assign_type == NET_ADDR_PERM)
+		memcpy(dev->perm_addr, dev->dev_addr, dev->addr_len);
+
+	/* Notify protocols, that a new device appeared. */
+	ret = call_netdevice_notifiers(NETDEV_REGISTER, dev);
+	ret = notifier_to_errno(ret);
+	if (ret) {
+		/* Expect explicit free_netdev() on failure */
+		dev->needs_free_netdev = false;
+		unregister_netdevice_queue(dev, NULL);
+		goto out;
+	}
+	/*
+	 *	Prevent userspace races by waiting until the network
+	 *	device is fully setup before sending notifications.
+	 */
+	if (!dev->rtnl_link_ops ||
+	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
+		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
+
+out:
+	return ret;
+
+err_uninit:
+	if (dev->netdev_ops->ndo_uninit)
+		dev->netdev_ops->ndo_uninit(dev);
+	if (dev->priv_destructor)
+		dev->priv_destructor(dev);
+err_free_name:
+	netdev_name_node_free(dev->name_node);
+	goto out;
+}
+EXPORT_SYMBOL(register_netdevice);
+
+/**
+ *	init_dummy_netdev	- init a dummy network device for NAPI
+ *	@dev: device to init
+ *
+ *	This takes a network device structure and initialize the minimum
+ *	amount of fields so it can be used to schedule NAPI polls without
+ *	registering a full blown interface. This is to be used by drivers
+ *	that need to tie several hardware interfaces to a single NAPI
+ *	poll scheduler due to HW limitations.
+ */
+int init_dummy_netdev(struct net_device *dev)
+{
+	/* Clear everything. Note we don't initialize spinlocks
+	 * are they aren't supposed to be taken by any of the
+	 * NAPI code and this dummy netdev is supposed to be
+	 * only ever used for NAPI polls
+	 */
+	memset(dev, 0, sizeof(struct net_device));
+
+	/* make sure we BUG if trying to hit standard
+	 * register/unregister code path
+	 */
+	dev->reg_state = NETREG_DUMMY;
+
+	/* NAPI wants this */
+	INIT_LIST_HEAD(&dev->napi_list);
+
+	/* a dummy interface is started by default */
+	set_bit(__LINK_STATE_PRESENT, &dev->state);
+	set_bit(__LINK_STATE_START, &dev->state);
+
+	/* napi_busy_loop stats accounting wants this */
+	dev_net_set(dev, &init_net);
+
+	/* Note : We dont allocate pcpu_refcnt for dummy devices,
+	 * because users of this 'device' dont need to change
+	 * its refcount.
+	 */
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(init_dummy_netdev);
+
+
+/**
+ *	register_netdev	- register a network device
+ *	@dev: device to register
+ *
+ *	Take a completed network device structure and add it to the kernel
+ *	interfaces. A %NETDEV_REGISTER message is sent to the netdev notifier
+ *	chain. 0 is returned on success. A negative errno code is returned
+ *	on a failure to set up the device, or if the name is a duplicate.
+ *
+ *	This is a wrapper around register_netdevice that takes the rtnl semaphore
+ *	and expands the device name if you passed a format string to
+ *	alloc_netdev.
+ */
+int register_netdev(struct net_device *dev)
+{
+	int err;
+
+	if (rtnl_lock_killable())
+		return -EINTR;
+	err = register_netdevice(dev);
+	rtnl_unlock();
+	return err;
+}
+EXPORT_SYMBOL(register_netdev);
+
+int netdev_refcnt_read(const struct net_device *dev)
+{
+	int i, refcnt = 0;
+
+	for_each_possible_cpu(i)
+		refcnt += *per_cpu_ptr(dev->pcpu_refcnt, i);
+	return refcnt;
+}
+EXPORT_SYMBOL(netdev_refcnt_read);
+
+#define WAIT_REFS_MIN_MSECS 1
+#define WAIT_REFS_MAX_MSECS 250
+/**
+ * netdev_wait_allrefs - wait until all references are gone.
+ * @dev: target net_device
+ *
+ * This is called when unregistering network devices.
+ *
+ * Any protocol or device that holds a reference should register
+ * for netdevice notification, and cleanup and put back the
+ * reference if they receive an UNREGISTER event.
+ * We can get stuck here if buggy protocols don't correctly
+ * call dev_put.
+ */
+static void netdev_wait_allrefs(struct net_device *dev)
+{
+	unsigned long rebroadcast_time, warning_time;
+	int wait = 0, refcnt;
+
+	linkwatch_forget_dev(dev);
+
+	rebroadcast_time = warning_time = jiffies;
+	refcnt = netdev_refcnt_read(dev);
+
+	while (refcnt != 0) {
+		if (time_after(jiffies, rebroadcast_time + 1 * HZ)) {
+			rtnl_lock();
+
+			/* Rebroadcast unregister notification */
+			call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
+
+			__rtnl_unlock();
+			rcu_barrier();
+			rtnl_lock();
+
+			if (test_bit(__LINK_STATE_LINKWATCH_PENDING,
+				     &dev->state)) {
+				/* We must not have linkwatch events
+				 * pending on unregister. If this
+				 * happens, we simply run the queue
+				 * unscheduled, resulting in a noop
+				 * for this device.
+				 */
+				linkwatch_run_queue();
+			}
+
+			__rtnl_unlock();
+
+			rebroadcast_time = jiffies;
+		}
+
+		if (!wait) {
+			rcu_barrier();
+			wait = WAIT_REFS_MIN_MSECS;
+		} else {
+			msleep(wait);
+			wait = min(wait << 1, WAIT_REFS_MAX_MSECS);
+		}
+
+		refcnt = netdev_refcnt_read(dev);
+
+		if (refcnt && time_after(jiffies, warning_time + 10 * HZ)) {
+			pr_emerg("unregister_netdevice: waiting for %s to become free. Usage count = %d\n",
+				 dev->name, refcnt);
+			warning_time = jiffies;
+		}
+	}
+}
+
+/* The sequence is:
+ *
+ *	rtnl_lock();
+ *	...
+ *	register_netdevice(x1);
+ *	register_netdevice(x2);
+ *	...
+ *	unregister_netdevice(y1);
+ *	unregister_netdevice(y2);
+ *      ...
+ *	rtnl_unlock();
+ *	free_netdev(y1);
+ *	free_netdev(y2);
+ *
+ * We are invoked by rtnl_unlock().
+ * This allows us to deal with problems:
+ * 1) We can delete sysfs objects which invoke hotplug
+ *    without deadlocking with linkwatch via keventd.
+ * 2) Since we run with the RTNL semaphore not held, we can sleep
+ *    safely in order to wait for the netdev refcnt to drop to zero.
+ *
+ * We must not return until all unregister events added during
+ * the interval the lock was held have been completed.
+ */
+void netdev_run_todo(void)
+{
+	struct list_head list;
+#ifdef CONFIG_LOCKDEP
+	struct list_head unlink_list;
+
+	list_replace_init(&net_unlink_list, &unlink_list);
+
+	while (!list_empty(&unlink_list)) {
+		struct net_device *dev = list_first_entry(&unlink_list,
+							  struct net_device,
+							  unlink_list);
+		list_del_init(&dev->unlink_list);
+		dev->nested_level = dev->lower_level - 1;
+	}
+#endif
+
+	/* Snapshot list, allow later requests */
+	list_replace_init(&net_todo_list, &list);
+
+	__rtnl_unlock();
+
+
+	/* Wait for rcu callbacks to finish before next phase */
+	if (!list_empty(&list))
+		rcu_barrier();
+
+	while (!list_empty(&list)) {
+		struct net_device *dev
+			= list_first_entry(&list, struct net_device, todo_list);
+		list_del(&dev->todo_list);
+
+		if (unlikely(dev->reg_state != NETREG_UNREGISTERING)) {
+			pr_err("network todo '%s' but state %d\n",
+			       dev->name, dev->reg_state);
+			dump_stack();
+			continue;
+		}
+
+		dev->reg_state = NETREG_UNREGISTERED;
+
+		netdev_wait_allrefs(dev);
+
+		/* paranoia */
+		BUG_ON(netdev_refcnt_read(dev));
+		BUG_ON(!list_empty(&dev->ptype_all));
+		BUG_ON(!list_empty(&dev->ptype_specific));
+		WARN_ON(rcu_access_pointer(dev->ip_ptr));
+		WARN_ON(rcu_access_pointer(dev->ip6_ptr));
+
+		if (dev->priv_destructor)
+			dev->priv_destructor(dev);
+		if (dev->needs_free_netdev)
+			free_netdev(dev);
+
+		/* Report a network device has been unregistered */
+		rtnl_lock();
+		dev_net(dev)->dev_unreg_count--;
+		__rtnl_unlock();
+		wake_up(&netdev_unregistering_wq);
+
+		/* Free network device */
+		kobject_put(&dev->dev.kobj);
+	}
+}
+
+/* Convert net_device_stats to rtnl_link_stats64. rtnl_link_stats64 has
+ * all the same fields in the same order as net_device_stats, with only
+ * the type differing, but rtnl_link_stats64 may have additional fields
+ * at the end for newer counters.
+ */
+void netdev_stats_to_stats64(struct rtnl_link_stats64 *stats64,
+			     const struct net_device_stats *netdev_stats)
+{
+	size_t i, n = sizeof(*netdev_stats) / sizeof(atomic_long_t);
+	const atomic_long_t *src = (atomic_long_t *)netdev_stats;
+	u64 *dst = (u64 *)stats64;
+
+	BUILD_BUG_ON(n > sizeof(*stats64) / sizeof(u64));
+	for (i = 0; i < n; i++)
+		dst[i] = (unsigned long)atomic_long_read(&src[i]);
+	/* zero out counters that only exist in rtnl_link_stats64 */
+	memset((char *)stats64 + n * sizeof(u64), 0,
+	       sizeof(*stats64) - n * sizeof(u64));
+}
+EXPORT_SYMBOL(netdev_stats_to_stats64);
+
+/**
+ *	dev_get_stats	- get network device statistics
+ *	@dev: device to get statistics from
+ *	@storage: place to store stats
+ *
+ *	Get network statistics from device. Return @storage.
+ *	The device driver may provide its own method by setting
+ *	dev->netdev_ops->get_stats64 or dev->netdev_ops->get_stats;
+ *	otherwise the internal statistics structure is used.
+ */
+struct rtnl_link_stats64 *dev_get_stats(struct net_device *dev,
+					struct rtnl_link_stats64 *storage)
+{
+	const struct net_device_ops *ops = dev->netdev_ops;
+
+	if (ops->ndo_get_stats64) {
+		memset(storage, 0, sizeof(*storage));
+		ops->ndo_get_stats64(dev, storage);
+	} else if (ops->ndo_get_stats) {
+		netdev_stats_to_stats64(storage, ops->ndo_get_stats(dev));
+	} else {
+		netdev_stats_to_stats64(storage, &dev->stats);
+	}
+	storage->rx_dropped += (unsigned long)atomic_long_read(&dev->rx_dropped);
+	storage->tx_dropped += (unsigned long)atomic_long_read(&dev->tx_dropped);
+	storage->rx_nohandler += (unsigned long)atomic_long_read(&dev->rx_nohandler);
+	return storage;
+}
+EXPORT_SYMBOL(dev_get_stats);
+
+/**
+ *	dev_fetch_sw_netstats - get per-cpu network device statistics
+ *	@s: place to store stats
+ *	@netstats: per-cpu network stats to read from
+ *
+ *	Read per-cpu network statistics and populate the related fields in @s.
+ */
+void dev_fetch_sw_netstats(struct rtnl_link_stats64 *s,
+			   const struct pcpu_sw_netstats __percpu *netstats)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu) {
+		const struct pcpu_sw_netstats *stats;
+		struct pcpu_sw_netstats tmp;
+		unsigned int start;
+
+		stats = per_cpu_ptr(netstats, cpu);
+		do {
+			start = u64_stats_fetch_begin_irq(&stats->syncp);
+			tmp.rx_packets = stats->rx_packets;
+			tmp.rx_bytes   = stats->rx_bytes;
+			tmp.tx_packets = stats->tx_packets;
+			tmp.tx_bytes   = stats->tx_bytes;
+		} while (u64_stats_fetch_retry_irq(&stats->syncp, start));
+
+		s->rx_packets += tmp.rx_packets;
+		s->rx_bytes   += tmp.rx_bytes;
+		s->tx_packets += tmp.tx_packets;
+		s->tx_bytes   += tmp.tx_bytes;
+	}
+}
+EXPORT_SYMBOL_GPL(dev_fetch_sw_netstats);
+
+struct netdev_queue *dev_ingress_queue_create(struct net_device *dev)
+{
+	struct netdev_queue *queue = dev_ingress_queue(dev);
+
+#ifdef CONFIG_NET_CLS_ACT
+	if (queue)
+		return queue;
+	queue = kzalloc(sizeof(*queue), GFP_KERNEL);
+	if (!queue)
+		return NULL;
+	netdev_init_one_queue(dev, queue, NULL);
+	RCU_INIT_POINTER(queue->qdisc, &noop_qdisc);
+	queue->qdisc_sleeping = &noop_qdisc;
+	rcu_assign_pointer(dev->ingress_queue, queue);
+#endif
+	return queue;
+}
+
+static const struct ethtool_ops default_ethtool_ops;
+
+void netdev_set_default_ethtool_ops(struct net_device *dev,
+				    const struct ethtool_ops *ops)
+{
+	if (dev->ethtool_ops == &default_ethtool_ops)
+		dev->ethtool_ops = ops;
+}
+EXPORT_SYMBOL_GPL(netdev_set_default_ethtool_ops);
+
+void netdev_freemem(struct net_device *dev)
+{
+	char *addr = (char *)dev - dev->padded;
+
+	kvfree(addr);
+}
+
+/**
+ * alloc_netdev_mqs - allocate network device
+ * @sizeof_priv: size of private data to allocate space for
+ * @name: device name format string
+ * @name_assign_type: origin of device name
+ * @setup: callback to initialize device
+ * @txqs: the number of TX subqueues to allocate
+ * @rxqs: the number of RX subqueues to allocate
+ *
+ * Allocates a struct net_device with private data area for driver use
+ * and performs basic initialization.  Also allocates subqueue structs
+ * for each queue on the device.
+ */
+struct net_device *alloc_netdev_mqs(int sizeof_priv, const char *name,
+		unsigned char name_assign_type,
+		void (*setup)(struct net_device *),
+		unsigned int txqs, unsigned int rxqs)
+{
+	struct net_device *dev;
+	unsigned int alloc_size;
+	struct net_device *p;
+
+	BUG_ON(strlen(name) >= sizeof(dev->name));
+
+	if (txqs < 1) {
+		pr_err("alloc_netdev: Unable to allocate device with zero queues\n");
+		return NULL;
+	}
+
+	if (rxqs < 1) {
+		pr_err("alloc_netdev: Unable to allocate device with zero RX queues\n");
+		return NULL;
+	}
+
+	alloc_size = sizeof(struct net_device);
+	if (sizeof_priv) {
+		/* ensure 32-byte alignment of private area */
+		alloc_size = ALIGN(alloc_size, NETDEV_ALIGN);
+		alloc_size += sizeof_priv;
+	}
+	/* ensure 32-byte alignment of whole construct */
+	alloc_size += NETDEV_ALIGN - 1;
+
+	p = kvzalloc(alloc_size, GFP_KERNEL | __GFP_RETRY_MAYFAIL);
+	if (!p)
+		return NULL;
+
+	dev = PTR_ALIGN(p, NETDEV_ALIGN);
+	dev->padded = (char *)dev - (char *)p;
+
+	dev->pcpu_refcnt = alloc_percpu(int);
+	if (!dev->pcpu_refcnt)
+		goto free_dev;
+
+	if (dev_addr_init(dev))
+		goto free_pcpu;
+
+	dev_mc_init(dev);
+	dev_uc_init(dev);
+
+	dev_net_set(dev, &init_net);
+
+	dev->gso_max_size = GSO_MAX_SIZE;
+	dev->gso_max_segs = GSO_MAX_SEGS;
+	dev->upper_level = 1;
+	dev->lower_level = 1;
+#ifdef CONFIG_LOCKDEP
+	dev->nested_level = 0;
+	INIT_LIST_HEAD(&dev->unlink_list);
+#endif
+
+	INIT_LIST_HEAD(&dev->napi_list);
+	INIT_LIST_HEAD(&dev->unreg_list);
+	INIT_LIST_HEAD(&dev->close_list);
+	INIT_LIST_HEAD(&dev->link_watch_list);
+	INIT_LIST_HEAD(&dev->adj_list.upper);
+	INIT_LIST_HEAD(&dev->adj_list.lower);
+	INIT_LIST_HEAD(&dev->ptype_all);
+	INIT_LIST_HEAD(&dev->ptype_specific);
+	INIT_LIST_HEAD(&dev->net_notifier_list);
+#ifdef CONFIG_NET_SCHED
+	hash_init(dev->qdisc_hash);
+#endif
+	dev->priv_flags = IFF_XMIT_DST_RELEASE | IFF_XMIT_DST_RELEASE_PERM;
+	setup(dev);
+
+	if (!dev->tx_queue_len) {
+		dev->priv_flags |= IFF_NO_QUEUE;
+		dev->tx_queue_len = DEFAULT_TX_QUEUE_LEN;
+	}
+
+	dev->num_tx_queues = txqs;
+	dev->real_num_tx_queues = txqs;
+	if (netif_alloc_netdev_queues(dev))
+		goto free_all;
+
+	dev->num_rx_queues = rxqs;
+	dev->real_num_rx_queues = rxqs;
+	if (netif_alloc_rx_queues(dev))
+		goto free_all;
+
+	strcpy(dev->name, name);
+	dev->name_assign_type = name_assign_type;
+	dev->group = INIT_NETDEV_GROUP;
+	if (!dev->ethtool_ops)
+		dev->ethtool_ops = &default_ethtool_ops;
+
+	nf_hook_ingress_init(dev);
+
+	return dev;
+
+free_all:
+	free_netdev(dev);
+	return NULL;
+
+free_pcpu:
+	free_percpu(dev->pcpu_refcnt);
+free_dev:
+	netdev_freemem(dev);
+	return NULL;
+}
+EXPORT_SYMBOL(alloc_netdev_mqs);
+
+/**
+ * free_netdev - free network device
+ * @dev: device
+ *
+ * This function does the last stage of destroying an allocated device
+ * interface. The reference to the device object is released. If this
+ * is the last reference then it will be freed.Must be called in process
+ * context.
+ */
+void free_netdev(struct net_device *dev)
+{
+	struct napi_struct *p, *n;
+
+	might_sleep();
+
+	/* When called immediately after register_netdevice() failed the unwind
+	 * handling may still be dismantling the device. Handle that case by
+	 * deferring the free.
+	 */
+	if (dev->reg_state == NETREG_UNREGISTERING) {
+		ASSERT_RTNL();
+		dev->needs_free_netdev = true;
+		return;
+	}
+
+	netif_free_tx_queues(dev);
+	netif_free_rx_queues(dev);
+
+	kfree(rcu_dereference_protected(dev->ingress_queue, 1));
+
+	/* Flush device addresses */
+	dev_addr_flush(dev);
+
+	list_for_each_entry_safe(p, n, &dev->napi_list, dev_list)
+		netif_napi_del(p);
+
+	free_percpu(dev->pcpu_refcnt);
+	dev->pcpu_refcnt = NULL;
+	free_percpu(dev->xdp_bulkq);
+	dev->xdp_bulkq = NULL;
+
+	/*  Compatibility with error handling in drivers */
+	if (dev->reg_state == NETREG_UNINITIALIZED) {
+		netdev_freemem(dev);
+		return;
+	}
+
+	BUG_ON(dev->reg_state != NETREG_UNREGISTERED);
+	dev->reg_state = NETREG_RELEASED;
+
+	/* will free via device release */
+	put_device(&dev->dev);
+}
+EXPORT_SYMBOL(free_netdev);
+
+/**
+ *	synchronize_net -  Synchronize with packet receive processing
+ *
+ *	Wait for packets currently being received to be done.
+ *	Does not block later packets from starting.
+ */
+void synchronize_net(void)
+{
+	might_sleep();
+	if (rtnl_is_locked())
+		synchronize_rcu_expedited();
+	else
+		synchronize_rcu();
+}
+EXPORT_SYMBOL(synchronize_net);
+
+/**
+ *	unregister_netdevice_queue - remove device from the kernel
+ *	@dev: device
+ *	@head: list
+ *
+ *	This function shuts down a device interface and removes it
+ *	from the kernel tables.
+ *	If head not NULL, device is queued to be unregistered later.
+ *
+ *	Callers must hold the rtnl semaphore.  You may want
+ *	unregister_netdev() instead of this.
+ */
+
+void unregister_netdevice_queue(struct net_device *dev, struct list_head *head)
+{
+	ASSERT_RTNL();
+
+	if (head) {
+		list_move_tail(&dev->unreg_list, head);
+	} else {
+		LIST_HEAD(single);
+
+		list_add(&dev->unreg_list, &single);
+		unregister_netdevice_many(&single);
+	}
+}
+EXPORT_SYMBOL(unregister_netdevice_queue);
+
+/**
+ *	unregister_netdevice_many - unregister many devices
+ *	@head: list of devices
+ *
+ *  Note: As most callers use a stack allocated list_head,
+ *  we force a list_del() to make sure stack wont be corrupted later.
+ */
+void unregister_netdevice_many(struct list_head *head)
+{
+	struct net_device *dev, *tmp;
+	LIST_HEAD(close_head);
+
+	BUG_ON(dev_boot_phase);
+	ASSERT_RTNL();
+
+	if (list_empty(head))
+		return;
+
+	list_for_each_entry_safe(dev, tmp, head, unreg_list) {
+		/* Some devices call without registering
+		 * for initialization unwind. Remove those
+		 * devices and proceed with the remaining.
+		 */
+		if (dev->reg_state == NETREG_UNINITIALIZED) {
+			pr_debug("unregister_netdevice: device %s/%p never was registered\n",
+				 dev->name, dev);
+
+			WARN_ON(1);
+			list_del(&dev->unreg_list);
+			continue;
+		}
+		dev->dismantle = true;
+		BUG_ON(dev->reg_state != NETREG_REGISTERED);
+	}
+
+	/* If device is running, close it first. */
+	list_for_each_entry(dev, head, unreg_list)
+		list_add_tail(&dev->close_list, &close_head);
+	dev_close_many(&close_head, true);
+
+	list_for_each_entry(dev, head, unreg_list) {
+		/* And unlink it from device chain. */
+		unlist_netdevice(dev);
+
+		dev->reg_state = NETREG_UNREGISTERING;
+	}
+	flush_all_backlogs();
+
+	synchronize_net();
+
+	list_for_each_entry(dev, head, unreg_list) {
+		struct sk_buff *skb = NULL;
+
+		/* Shutdown queueing discipline. */
+		dev_shutdown(dev);
+
+		dev_xdp_uninstall(dev);
+
+		/* Notify protocols, that we are about to destroy
+		 * this device. They should clean all the things.
+		 */
+		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
+
+		if (!dev->rtnl_link_ops ||
+		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)
+			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,
+						     GFP_KERNEL, NULL, 0);
+
+		/*
+		 *	Flush the unicast and multicast chains
+		 */
+		dev_uc_flush(dev);
+		dev_mc_flush(dev);
+
+		netdev_name_node_alt_flush(dev);
+		netdev_name_node_free(dev->name_node);
+
+		if (dev->netdev_ops->ndo_uninit)
+			dev->netdev_ops->ndo_uninit(dev);
+
+		if (skb)
+			rtmsg_ifinfo_send(skb, dev, GFP_KERNEL);
+
+		/* Notifier chain MUST detach us all upper devices. */
+		WARN_ON(netdev_has_any_upper_dev(dev));
+		WARN_ON(netdev_has_any_lower_dev(dev));
+
+		/* Remove entries from kobject tree */
+		netdev_unregister_kobject(dev);
+#ifdef CONFIG_XPS
+		/* Remove XPS queueing entries */
+		netif_reset_xps_queues_gt(dev, 0);
+#endif
+	}
+
+	synchronize_net();
+
+	list_for_each_entry(dev, head, unreg_list) {
+		dev_put(dev);
+		net_set_todo(dev);
+	}
+
+	list_del(head);
+}
+EXPORT_SYMBOL(unregister_netdevice_many);
+
+/**
+ *	unregister_netdev - remove device from the kernel
+ *	@dev: device
+ *
+ *	This function shuts down a device interface and removes it
+ *	from the kernel tables.
+ *
+ *	This is just a wrapper for unregister_netdevice that takes
+ *	the rtnl semaphore.  In general you want to use this and not
+ *	unregister_netdevice.
+ */
+void unregister_netdev(struct net_device *dev)
+{
+	rtnl_lock();
+	unregister_netdevice(dev);
+	rtnl_unlock();
+}
+EXPORT_SYMBOL(unregister_netdev);
+
+/**
+ *	dev_change_net_namespace - move device to different nethost namespace
+ *	@dev: device
+ *	@net: network namespace
+ *	@pat: If not NULL name pattern to try if the current device name
+ *	      is already taken in the destination network namespace.
+ *
+ *	This function shuts down a device interface and moves it
+ *	to a new network namespace. On success 0 is returned, on
+ *	a failure a netagive errno code is returned.
+ *
+ *	Callers must hold the rtnl semaphore.
+ */
+
+int dev_change_net_namespace(struct net_device *dev, struct net *net, const char *pat)
+{
+	struct net *net_old = dev_net(dev);
+	int err, new_nsid, new_ifindex;
+
+	ASSERT_RTNL();
+
+	/* Don't allow namespace local devices to be moved. */
+	err = -EINVAL;
+	if (dev->features & NETIF_F_NETNS_LOCAL)
+		goto out;
+
+	/* Ensure the device has been registrered */
+	if (dev->reg_state != NETREG_REGISTERED)
+		goto out;
+
+	/* Get out if there is nothing todo */
+	err = 0;
+	if (net_eq(net_old, net))
+		goto out;
+
+	/* Pick the destination device name, and ensure
+	 * we can use it in the destination network namespace.
+	 */
+	err = -EEXIST;
+	if (__dev_get_by_name(net, dev->name)) {
+		/* We get here if we can't use the current device name */
+		if (!pat)
+			goto out;
+		err = dev_get_valid_name(net, dev, pat);
+		if (err < 0)
+			goto out;
+	}
+
+	/*
+	 * And now a mini version of register_netdevice unregister_netdevice.
+	 */
+
+	/* If device is running close it first. */
+	dev_close(dev);
+
+	/* And unlink it from device chain */
+	unlist_netdevice(dev);
+
+	synchronize_net();
+
+	/* Shutdown queueing discipline. */
+	dev_shutdown(dev);
+
+	/* Notify protocols, that we are about to destroy
+	 * this device. They should clean all the things.
+	 *
+	 * Note that dev->reg_state stays at NETREG_REGISTERED.
+	 * This is wanted because this way 8021q and macvlan know
+	 * the device is just moving and can keep their slaves up.
+	 */
+	call_netdevice_notifiers(NETDEV_UNREGISTER, dev);
+	rcu_barrier();
+
+	new_nsid = peernet2id_alloc(dev_net(dev), net, GFP_KERNEL);
+	/* If there is an ifindex conflict assign a new one */
+	if (__dev_get_by_index(net, dev->ifindex))
+		new_ifindex = dev_new_index(net);
+	else
+		new_ifindex = dev->ifindex;
+
+	rtmsg_ifinfo_newnet(RTM_DELLINK, dev, ~0U, GFP_KERNEL, &new_nsid,
+			    new_ifindex);
+
+	/*
+	 *	Flush the unicast and multicast chains
+	 */
+	dev_uc_flush(dev);
+	dev_mc_flush(dev);
+
+	/* Send a netdev-removed uevent to the old namespace */
+	kobject_uevent(&dev->dev.kobj, KOBJ_REMOVE);
+	netdev_adjacent_del_links(dev);
+
+	/* Move per-net netdevice notifiers that are following the netdevice */
+	move_netdevice_notifiers_dev_net(dev, net);
+
+	/* Actually switch the network namespace */
+	dev_net_set(dev, net);
+	dev->ifindex = new_ifindex;
+
+	/* Send a netdev-add uevent to the new namespace */
+	kobject_uevent(&dev->dev.kobj, KOBJ_ADD);
+	netdev_adjacent_add_links(dev);
+
+	/* Fixup kobjects */
+	err = device_rename(&dev->dev, dev->name);
+	WARN_ON(err);
+
+	/* Adapt owner in case owning user namespace of target network
+	 * namespace is different from the original one.
+	 */
+	err = netdev_change_owner(dev, net_old, net);
+	WARN_ON(err);
+
+	/* Add the device back in the hashes */
+	list_netdevice(dev);
+
+	/* Notify protocols, that a new device appeared. */
+	call_netdevice_notifiers(NETDEV_REGISTER, dev);
+
+	/*
+	 *	Prevent userspace races by waiting until the network
+	 *	device is fully setup before sending notifications.
+	 */
+	rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL);
+
+	synchronize_net();
+	err = 0;
+out:
+	return err;
+}
+EXPORT_SYMBOL_GPL(dev_change_net_namespace);
+
+static int dev_cpu_dead(unsigned int oldcpu)
+{
+	struct sk_buff **list_skb;
+	struct sk_buff *skb;
+	unsigned int cpu;
+	struct softnet_data *sd, *oldsd, *remsd = NULL;
+
+	local_irq_disable();
+	cpu = smp_processor_id();
+	sd = &per_cpu(softnet_data, cpu);
+	oldsd = &per_cpu(softnet_data, oldcpu);
+
+	/* Find end of our completion_queue. */
+	list_skb = &sd->completion_queue;
+	while (*list_skb)
+		list_skb = &(*list_skb)->next;
+	/* Append completion queue from offline CPU. */
+	*list_skb = oldsd->completion_queue;
+	oldsd->completion_queue = NULL;
+
+	/* Append output queue from offline CPU. */
+	if (oldsd->output_queue) {
+		*sd->output_queue_tailp = oldsd->output_queue;
+		sd->output_queue_tailp = oldsd->output_queue_tailp;
+		oldsd->output_queue = NULL;
+		oldsd->output_queue_tailp = &oldsd->output_queue;
+	}
+	/* Append NAPI poll list from offline CPU, with one exception :
+	 * process_backlog() must be called by cpu owning percpu backlog.
+	 * We properly handle process_queue & input_pkt_queue later.
+	 */
+	while (!list_empty(&oldsd->poll_list)) {
+		struct napi_struct *napi = list_first_entry(&oldsd->poll_list,
+							    struct napi_struct,
+							    poll_list);
+
+		list_del_init(&napi->poll_list);
+		if (napi->poll == process_backlog)
+			napi->state = 0;
+		else
+			____napi_schedule(sd, napi);
+	}
+
+	raise_softirq_irqoff(NET_TX_SOFTIRQ);
+	local_irq_enable();
+
+#ifdef CONFIG_RPS
+	remsd = oldsd->rps_ipi_list;
+	oldsd->rps_ipi_list = NULL;
+#endif
+	/* send out pending IPI's on offline CPU */
+	net_rps_send_ipi(remsd);
+
+	/* Process offline CPU's input_pkt_queue */
+	while ((skb = __skb_dequeue(&oldsd->process_queue))) {
+		netif_rx_ni(skb);
+		input_queue_head_incr(oldsd);
+	}
+	while ((skb = skb_dequeue(&oldsd->input_pkt_queue))) {
+		netif_rx_ni(skb);
+		input_queue_head_incr(oldsd);
+	}
+
+	return 0;
+}
+
+/**
+ *	netdev_increment_features - increment feature set by one
+ *	@all: current feature set
+ *	@one: new feature set
+ *	@mask: mask feature set
+ *
+ *	Computes a new feature set after adding a device with feature set
+ *	@one to the master device with current feature set @all.  Will not
+ *	enable anything that is off in @mask. Returns the new feature set.
+ */
+netdev_features_t netdev_increment_features(netdev_features_t all,
+	netdev_features_t one, netdev_features_t mask)
+{
+	if (mask & NETIF_F_HW_CSUM)
+		mask |= NETIF_F_CSUM_MASK;
+	mask |= NETIF_F_VLAN_CHALLENGED;
+
+	all |= one & (NETIF_F_ONE_FOR_ALL | NETIF_F_CSUM_MASK) & mask;
+	all &= one | ~NETIF_F_ALL_FOR_ALL;
+
+	/* If one device supports hw checksumming, set for all. */
+	if (all & NETIF_F_HW_CSUM)
+		all &= ~(NETIF_F_CSUM_MASK & ~NETIF_F_HW_CSUM);
+
+	return all;
+}
+EXPORT_SYMBOL(netdev_increment_features);
+
+static struct hlist_head * __net_init netdev_create_hash(void)
+{
+	int i;
+	struct hlist_head *hash;
+
+	hash = kmalloc_array(NETDEV_HASHENTRIES, sizeof(*hash), GFP_KERNEL);
+	if (hash != NULL)
+		for (i = 0; i < NETDEV_HASHENTRIES; i++)
+			INIT_HLIST_HEAD(&hash[i]);
+
+	return hash;
+}
+
+/* Initialize per network namespace state */
+static int __net_init netdev_init(struct net *net)
+{
+	BUILD_BUG_ON(GRO_HASH_BUCKETS >
+		     8 * sizeof_field(struct napi_struct, gro_bitmask));
+
+	if (net != &init_net)
+		INIT_LIST_HEAD(&net->dev_base_head);
+
+	net->dev_name_head = netdev_create_hash();
+	if (net->dev_name_head == NULL)
+		goto err_name;
+
+	net->dev_index_head = netdev_create_hash();
+	if (net->dev_index_head == NULL)
+		goto err_idx;
+
+	RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain);
+
+	return 0;
+
+err_idx:
+	kfree(net->dev_name_head);
+err_name:
+	return -ENOMEM;
+}
+
+/**
+ *	netdev_drivername - network driver for the device
+ *	@dev: network device
+ *
+ *	Determine network driver for device.
+ */
+const char *netdev_drivername(const struct net_device *dev)
+{
+	const struct device_driver *driver;
+	const struct device *parent;
+	const char *empty = "";
+
+	parent = dev->dev.parent;
+	if (!parent)
+		return empty;
+
+	driver = parent->driver;
+	if (driver && driver->name)
+		return driver->name;
+	return empty;
+}
+
+static void __netdev_printk(const char *level, const struct net_device *dev,
+			    struct va_format *vaf)
+{
+	if (dev && dev->dev.parent) {
+		dev_printk_emit(level[1] - '0',
+				dev->dev.parent,
+				"%s %s %s%s: %pV",
+				dev_driver_string(dev->dev.parent),
+				dev_name(dev->dev.parent),
+				netdev_name(dev), netdev_reg_state(dev),
+				vaf);
+	} else if (dev) {
+		printk("%s%s%s: %pV",
+		       level, netdev_name(dev), netdev_reg_state(dev), vaf);
+	} else {
+		printk("%s(NULL net_device): %pV", level, vaf);
+	}
+}
+
+void netdev_printk(const char *level, const struct net_device *dev,
+		   const char *format, ...)
+{
+	struct va_format vaf;
+	va_list args;
+
+	va_start(args, format);
+
+	vaf.fmt = format;
+	vaf.va = &args;
+
+	__netdev_printk(level, dev, &vaf);
+
+	va_end(args);
+}
+EXPORT_SYMBOL(netdev_printk);
+
+#define define_netdev_printk_level(func, level)			\
+void func(const struct net_device *dev, const char *fmt, ...)	\
+{								\
+	struct va_format vaf;					\
+	va_list args;						\
+								\
+	va_start(args, fmt);					\
+								\
+	vaf.fmt = fmt;						\
+	vaf.va = &args;						\
+								\
+	__netdev_printk(level, dev, &vaf);			\
+								\
+	va_end(args);						\
+}								\
+EXPORT_SYMBOL(func);
+
+define_netdev_printk_level(netdev_emerg, KERN_EMERG);
+define_netdev_printk_level(netdev_alert, KERN_ALERT);
+define_netdev_printk_level(netdev_crit, KERN_CRIT);
+define_netdev_printk_level(netdev_err, KERN_ERR);
+define_netdev_printk_level(netdev_warn, KERN_WARNING);
+define_netdev_printk_level(netdev_notice, KERN_NOTICE);
+define_netdev_printk_level(netdev_info, KERN_INFO);
+
+static void __net_exit netdev_exit(struct net *net)
+{
+	kfree(net->dev_name_head);
+	kfree(net->dev_index_head);
+	if (net != &init_net)
+		WARN_ON_ONCE(!list_empty(&net->dev_base_head));
+}
+
+static struct pernet_operations __net_initdata netdev_net_ops = {
+	.init = netdev_init,
+	.exit = netdev_exit,
+};
+
+static void __net_exit default_device_exit(struct net *net)
+{
+	struct net_device *dev, *aux;
+	/*
+	 * Push all migratable network devices back to the
+	 * initial network namespace
+	 */
+	rtnl_lock();
+	for_each_netdev_safe(net, dev, aux) {
+		int err;
+		char fb_name[IFNAMSIZ];
+
+		/* Ignore unmoveable devices (i.e. loopback) */
+		if (dev->features & NETIF_F_NETNS_LOCAL)
+			continue;
+
+		/* Leave virtual devices for the generic cleanup */
+		if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund)
+			continue;
+
+		/* Push remaining network devices to init_net */
+		snprintf(fb_name, IFNAMSIZ, "dev%d", dev->ifindex);
+		if (__dev_get_by_name(&init_net, fb_name))
+			snprintf(fb_name, IFNAMSIZ, "dev%%d");
+		err = dev_change_net_namespace(dev, &init_net, fb_name);
+		if (err) {
+			pr_emerg("%s: failed to move %s to init_net: %d\n",
+				 __func__, dev->name, err);
+			BUG();
+		}
+	}
+	rtnl_unlock();
+}
+
+static void __net_exit rtnl_lock_unregistering(struct list_head *net_list)
+{
+	/* Return with the rtnl_lock held when there are no network
+	 * devices unregistering in any network namespace in net_list.
+	 */
+	struct net *net;
+	bool unregistering;
+	DEFINE_WAIT_FUNC(wait, woken_wake_function);
+
+	add_wait_queue(&netdev_unregistering_wq, &wait);
+	for (;;) {
+		unregistering = false;
+		rtnl_lock();
+		list_for_each_entry(net, net_list, exit_list) {
+			if (net->dev_unreg_count > 0) {
+				unregistering = true;
+				break;
+			}
+		}
+		if (!unregistering)
+			break;
+		__rtnl_unlock();
+
+		wait_woken(&wait, TASK_UNINTERRUPTIBLE, MAX_SCHEDULE_TIMEOUT);
+	}
+	remove_wait_queue(&netdev_unregistering_wq, &wait);
+}
+
+static void __net_exit default_device_exit_batch(struct list_head *net_list)
+{
+	/* At exit all network devices most be removed from a network
+	 * namespace.  Do this in the reverse order of registration.
+	 * Do this across as many network namespaces as possible to
+	 * improve batching efficiency.
+	 */
+	struct net_device *dev;
+	struct net *net;
+	LIST_HEAD(dev_kill_list);
+
+	/* To prevent network device cleanup code from dereferencing
+	 * loopback devices or network devices that have been freed
+	 * wait here for all pending unregistrations to complete,
+	 * before unregistring the loopback device and allowing the
+	 * network namespace be freed.
+	 *
+	 * The netdev todo list containing all network devices
+	 * unregistrations that happen in default_device_exit_batch
+	 * will run in the rtnl_unlock() at the end of
+	 * default_device_exit_batch.
+	 */
+	rtnl_lock_unregistering(net_list);
+	list_for_each_entry(net, net_list, exit_list) {
+		for_each_netdev_reverse(net, dev) {
+			if (dev->rtnl_link_ops && dev->rtnl_link_ops->dellink)
+				dev->rtnl_link_ops->dellink(dev, &dev_kill_list);
+			else
+				unregister_netdevice_queue(dev, &dev_kill_list);
+		}
+	}
+	unregister_netdevice_many(&dev_kill_list);
+	rtnl_unlock();
+}
+
+static struct pernet_operations __net_initdata default_device_ops = {
+	.exit = default_device_exit,
+	.exit_batch = default_device_exit_batch,
+};
+
+/*
+ *	Initialize the DEV module. At boot time this walks the device list and
+ *	unhooks any devices that fail to initialise (normally hardware not
+ *	present) and leaves us with a valid list of present and active devices.
+ *
+ */
+
+/*
+ *       This is called single threaded during boot, so no need
+ *       to take the rtnl semaphore.
+ */
+static int __init net_dev_init(void)
+{
+	int i, rc = -ENOMEM;
+
+	BUG_ON(!dev_boot_phase);
+
+	if (dev_proc_init())
+		goto out;
+
+	if (netdev_kobject_init())
+		goto out;
+
+	INIT_LIST_HEAD(&ptype_all);
+	for (i = 0; i < PTYPE_HASH_SIZE; i++)
+		INIT_LIST_HEAD(&ptype_base[i]);
+
+	INIT_LIST_HEAD(&offload_base);
+
+	if (register_pernet_subsys(&netdev_net_ops))
+		goto out;
+
+	/*
+	 *	Initialise the packet receive queues.
+	 */
+
+	for_each_possible_cpu(i) {
+		struct work_struct *flush = per_cpu_ptr(&flush_works, i);
+		struct softnet_data *sd = &per_cpu(softnet_data, i);
+
+		INIT_WORK(flush, flush_backlog);
+
+		skb_queue_head_init(&sd->input_pkt_queue);
+		skb_queue_head_init(&sd->process_queue);
+#ifdef CONFIG_XFRM_OFFLOAD
+		skb_queue_head_init(&sd->xfrm_backlog);
+#endif
+		INIT_LIST_HEAD(&sd->poll_list);
+		sd->output_queue_tailp = &sd->output_queue;
+#ifdef CONFIG_RPS
+		sd->csd.func = rps_trigger_softirq;
+		sd->csd.info = sd;
+		sd->cpu = i;
+#endif
+
+		init_gro_hash(&sd->backlog);
+		sd->backlog.poll = process_backlog;
+		sd->backlog.weight = weight_p;
+	}
+
+	dev_boot_phase = 0;
+
+	/* The loopback device is special if any other network devices
+	 * is present in a network namespace the loopback device must
+	 * be present. Since we now dynamically allocate and free the
+	 * loopback device ensure this invariant is maintained by
+	 * keeping the loopback device as the first device on the
+	 * list of network devices.  Ensuring the loopback devices
+	 * is the first device that appears and the last network device
+	 * that disappears.
+	 */
+	if (register_pernet_device(&loopback_net_ops))
+		goto out;
+
+	if (register_pernet_device(&default_device_ops))
+		goto out;
+
+	open_softirq(NET_TX_SOFTIRQ, net_tx_action);
+	open_softirq(NET_RX_SOFTIRQ, net_rx_action);
+
+	rc = cpuhp_setup_state_nocalls(CPUHP_NET_DEV_DEAD, "net/dev:dead",
+				       NULL, dev_cpu_dead);
+	WARN_ON(rc < 0);
+	rc = 0;
+out:
+	return rc;
+}
+
+subsys_initcall(net_dev_init);