/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * INET         An implementation of the TCP/IP protocol suite for the LINUX
 *              operating system.  INET is implemented using the  BSD Socket
 *              interface as the means of communication with the user level.
 *
 *              Definitions for the Interfaces handler.
 *
 * Version:     @(#)dev.h       1.0.10  08/12/93
 *
 * Authors:     Ross Biro
 *              Fred N. van Kempen, <waltje@uWalt.NL.Mugnet.ORG>
 *              Corey Minyard <wf-rch!minyard@relay.EU.net>
 *              Donald J. Becker, <becker@cesdis.gsfc.nasa.gov>
 *              Alan Cox, <alan@lxorguk.ukuu.org.uk>
 *              Bjorn Ekwall. <bj0rn@blox.se>
 *              Pekka Riikonen <priikone@poseidon.pspt.fi>
 *
 *              Moved to /usr/include/linux for NET3
 */
#ifndef _LINUX_NETDEVICE_H
#define _LINUX_NETDEVICE_H

#include <linux/timer.h>
#include <linux/bug.h>
#include <linux/delay.h>
#include <linux/atomic.h>
#include <linux/prefetch.h>
#include <asm/cache.h>
#include <asm/byteorder.h>

#include <linux/percpu.h>
#include <linux/rculist.h>
#include <linux/workqueue.h>
#include <linux/dynamic_queue_limits.h>

#include <net/net_namespace.h>
#ifdef CONFIG_DCB
#include <net/dcbnl.h>
#endif
#include <net/netprio_cgroup.h>
#include <net/xdp.h>

#include <linux/netdev_features.h>
#include <linux/neighbour.h>
#include <uapi/linux/netdevice.h>
#include <uapi/linux/if_bonding.h>
#include <uapi/linux/pkt_cls.h>
#include <linux/hashtable.h>
#include <linux/rbtree.h>

struct netpoll_info;
struct device;
struct ethtool_ops;
struct phy_device;
struct dsa_port;
struct ip_tunnel_parm;
struct macsec_context;
struct macsec_ops;

struct sfp_bus;
/* 802.11 specific */
struct wireless_dev;
/* 802.15.4 specific */
struct wpan_dev;
struct mpls_dev;
/* UDP Tunnel offloads */
struct udp_tunnel_info;
struct udp_tunnel_nic_info;
struct udp_tunnel_nic;
struct bpf_prog;
struct xdp_buff;

void synchronize_net(void);
void netdev_set_default_ethtool_ops(struct net_device *dev,
                                    const struct ethtool_ops *ops);

/* Backlog congestion levels */
#define NET_RX_SUCCESS          0       /* keep 'em coming, baby */
#define NET_RX_DROP             1       /* packet dropped */

#define MAX_NEST_DEV 8

/*
 * Transmit return codes: transmit return codes originate from three different
 * namespaces:
 *
 * - qdisc return codes
 * - driver transmit return codes
 * - errno values
 *
 * Drivers are allowed to return any one of those in their hard_start_xmit()
 * function. Real network devices commonly used with qdiscs should only return
 * the driver transmit return codes though - when qdiscs are used, the actual
 * transmission happens asynchronously, so the value is not propagated to
 * higher layers. Virtual network devices transmit synchronously; in this case
 * the driver transmit return codes are consumed by dev_queue_xmit(), and all
 * others are propagated to higher layers.
 */

/* qdisc ->enqueue() return codes. */
#define NET_XMIT_SUCCESS        0x00
#define NET_XMIT_DROP           0x01    /* skb dropped                  */
#define NET_XMIT_CN             0x02    /* congestion notification      */
#define NET_XMIT_MASK           0x0f    /* qdisc flags in net/sch_generic.h */

/* NET_XMIT_CN is special. It does not guarantee that this packet is lost. It
 * indicates that the device will soon be dropping packets, or already drops
 * some packets of the same priority; prompting us to send less aggressively. */
#define net_xmit_eval(e)        ((e) == NET_XMIT_CN ? 0 : (e))
#define net_xmit_errno(e)       ((e) != NET_XMIT_CN ? -ENOBUFS : 0)

/* Driver transmit return codes */
#define NETDEV_TX_MASK          0xf0

enum netdev_tx {
        __NETDEV_TX_MIN  = INT_MIN,     /* make sure enum is signed */
        NETDEV_TX_OK     = 0x00,        /* driver took care of packet */
        NETDEV_TX_BUSY   = 0x10,        /* driver tx path was busy*/
};
typedef enum netdev_tx netdev_tx_t;

/*
 * Current order: NETDEV_TX_MASK > NET_XMIT_MASK >= 0 is significant;
 * hard_start_xmit() return < NET_XMIT_MASK means skb was consumed.
 */
static inline bool dev_xmit_complete(int rc)
{
        /*
         * Positive cases with an skb consumed by a driver:
         * - successful transmission (rc == NETDEV_TX_OK)
         * - error while transmitting (rc < 0)
         * - error while queueing to a different device (rc & NET_XMIT_MASK)
         */
        if (likely(rc < NET_XMIT_MASK))
                return true;

        return false;
}

/*
 *      Compute the worst-case header length according to the protocols
 *      used.
 */

#if defined(CONFIG_HYPERV_NET)
# define LL_MAX_HEADER 128
#elif defined(CONFIG_WLAN) || IS_ENABLED(CONFIG_AX25)
# if defined(CONFIG_MAC80211_MESH)
#  define LL_MAX_HEADER 128
# else
#  define LL_MAX_HEADER 96
# endif
#else
# define LL_MAX_HEADER 32
#endif

#if !IS_ENABLED(CONFIG_NET_IPIP) && !IS_ENABLED(CONFIG_NET_IPGRE) && \
    !IS_ENABLED(CONFIG_IPV6_SIT) && !IS_ENABLED(CONFIG_IPV6_TUNNEL)
#define MAX_HEADER LL_MAX_HEADER
#else
#define MAX_HEADER (LL_MAX_HEADER + 48)
#endif

/*
 *      Old network device statistics. Fields are native words
 *      (unsigned long) so they can be read and written atomically.
 */

struct net_device_stats {
        unsigned long   rx_packets;
        unsigned long   tx_packets;
        unsigned long   rx_bytes;
        unsigned long   tx_bytes;
        unsigned long   rx_errors;
        unsigned long   tx_errors;
        unsigned long   rx_dropped;
        unsigned long   tx_dropped;
        unsigned long   multicast;
        unsigned long   collisions;
        unsigned long   rx_length_errors;
        unsigned long   rx_over_errors;
        unsigned long   rx_crc_errors;
        unsigned long   rx_frame_errors;
        unsigned long   rx_fifo_errors;
        unsigned long   rx_missed_errors;
        unsigned long   tx_aborted_errors;
        unsigned long   tx_carrier_errors;
        unsigned long   tx_fifo_errors;
        unsigned long   tx_heartbeat_errors;
        unsigned long   tx_window_errors;
        unsigned long   rx_compressed;
        unsigned long   tx_compressed;
};


#include <linux/cache.h>
#include <linux/skbuff.h>

#ifdef CONFIG_RPS
#include <linux/static_key.h>
extern struct static_key_false rps_needed;
extern struct static_key_false rfs_needed;
#endif

struct neighbour;
struct neigh_parms;
struct sk_buff;

struct netdev_hw_addr {
        struct list_head        list;
        struct rb_node          node;
        unsigned char           addr[MAX_ADDR_LEN];
        unsigned char           type;
#define NETDEV_HW_ADDR_T_LAN            1
#define NETDEV_HW_ADDR_T_SAN            2
#define NETDEV_HW_ADDR_T_UNICAST        3
#define NETDEV_HW_ADDR_T_MULTICAST      4
        bool                    global_use;
        int                     sync_cnt;
        int                     refcount;
        int                     synced;
        struct rcu_head         rcu_head;
};

struct netdev_hw_addr_list {
        struct list_head        list;
        int                     count;

        /* Auxiliary tree for faster lookup on addition and deletion */
        struct rb_root          tree;
};

#define netdev_hw_addr_list_count(l) ((l)->count)
#define netdev_hw_addr_list_empty(l) (netdev_hw_addr_list_count(l) == 0)
#define netdev_hw_addr_list_for_each(ha, l) \
        list_for_each_entry(ha, &(l)->list, list)

#define netdev_uc_count(dev) netdev_hw_addr_list_count(&(dev)->uc)
#define netdev_uc_empty(dev) netdev_hw_addr_list_empty(&(dev)->uc)
#define netdev_for_each_uc_addr(ha, dev) \
        netdev_hw_addr_list_for_each(ha, &(dev)->uc)

#define netdev_mc_count(dev) netdev_hw_addr_list_count(&(dev)->mc)
#define netdev_mc_empty(dev) netdev_hw_addr_list_empty(&(dev)->mc)
#define netdev_for_each_mc_addr(ha, dev) \
        netdev_hw_addr_list_for_each(ha, &(dev)->mc)

struct hh_cache {
        unsigned int    hh_len;
        seqlock_t       hh_lock;

        /* cached hardware header; allow for machine alignment needs.        */
#define HH_DATA_MOD     16
#define HH_DATA_OFF(__len) \
        (HH_DATA_MOD - (((__len - 1) & (HH_DATA_MOD - 1)) + 1))
#define HH_DATA_ALIGN(__len) \
        (((__len)+(HH_DATA_MOD-1))&~(HH_DATA_MOD - 1))
        unsigned long   hh_data[HH_DATA_ALIGN(LL_MAX_HEADER) / sizeof(long)];
};

/* Reserve HH_DATA_MOD byte-aligned hard_header_len, but at least that much.
 * Alternative is:
 *   dev->hard_header_len ? (dev->hard_header_len +
 *                           (HH_DATA_MOD - 1)) & ~(HH_DATA_MOD - 1) : 0
 *
 * We could use other alignment values, but we must maintain the
 * relationship HH alignment <= LL alignment.
 */
#define LL_RESERVED_SPACE(dev) \
        ((((dev)->hard_header_len+(dev)->needed_headroom)&~(HH_DATA_MOD - 1)) + HH_DATA_MOD)
#define LL_RESERVED_SPACE_EXTRA(dev,extra) \
        ((((dev)->hard_header_len+(dev)->needed_headroom+(extra))&~(HH_DATA_MOD - 1)) + HH_DATA_MOD)

struct header_ops {
        int     (*create) (struct sk_buff *skb, struct net_device *dev,
                           unsigned short type, const void *daddr,
                           const void *saddr, unsigned int len);
        int     (*parse)(const struct sk_buff *skb, unsigned char *haddr);
        int     (*cache)(const struct neighbour *neigh, struct hh_cache *hh, __be16 type);
        void    (*cache_update)(struct hh_cache *hh,
                                const struct net_device *dev,
                                const unsigned char *haddr);
        bool    (*validate)(const char *ll_header, unsigned int len);
        __be16  (*parse_protocol)(const struct sk_buff *skb);
};

/* These flag bits are private to the generic network queueing
 * layer; they may not be explicitly referenced by any other
 * code.
 */

enum netdev_state_t {
        __LINK_STATE_START,
        __LINK_STATE_PRESENT,
        __LINK_STATE_NOCARRIER,
        __LINK_STATE_LINKWATCH_PENDING,
        __LINK_STATE_DORMANT,
        __LINK_STATE_TESTING,
};


struct gro_list {
        struct list_head        list;
        int                     count;
};

/*
 * size of gro hash buckets, must less than bit number of
 * napi_struct::gro_bitmask
 */
#define GRO_HASH_BUCKETS        8

/*
 * Structure for NAPI scheduling similar to tasklet but with weighting
 */
struct napi_struct {
        /* The poll_list must only be managed by the entity which
         * changes the state of the NAPI_STATE_SCHED bit.  This means
         * whoever atomically sets that bit can add this napi_struct
         * to the per-CPU poll_list, and whoever clears that bit
         * can remove from the list right before clearing the bit.
         */
        struct list_head        poll_list;

        unsigned long           state;
        int                     weight;
        int                     defer_hard_irqs_count;
        unsigned long           gro_bitmask;
        int                     (*poll)(struct napi_struct *, int);
#ifdef CONFIG_NETPOLL
        int                     poll_owner;
#endif
        struct net_device       *dev;
        struct gro_list         gro_hash[GRO_HASH_BUCKETS];
        struct sk_buff          *skb;
        struct list_head        rx_list; /* Pending GRO_NORMAL skbs */
        int                     rx_count; /* length of rx_list */
        struct hrtimer          timer;
        struct list_head        dev_list;
        struct hlist_node       napi_hash_node;
        unsigned int            napi_id;
        struct task_struct      *thread;
};

enum {
        NAPI_STATE_SCHED,               /* Poll is scheduled */
        NAPI_STATE_MISSED,              /* reschedule a napi */
        NAPI_STATE_DISABLE,             /* Disable pending */
        NAPI_STATE_NPSVC,               /* Netpoll - don't dequeue from poll_list */
        NAPI_STATE_LISTED,              /* NAPI added to system lists */
        NAPI_STATE_NO_BUSY_POLL,        /* Do not add in napi_hash, no busy polling */
        NAPI_STATE_IN_BUSY_POLL,        /* sk_busy_loop() owns this NAPI */
        NAPI_STATE_PREFER_BUSY_POLL,    /* prefer busy-polling over softirq processing*/
        NAPI_STATE_THREADED,            /* The poll is performed inside its own thread*/
        NAPI_STATE_SCHED_THREADED,      /* Napi is currently scheduled in threaded mode */
};

enum {
        NAPIF_STATE_SCHED               = BIT(NAPI_STATE_SCHED),
        NAPIF_STATE_MISSED              = BIT(NAPI_STATE_MISSED),
        NAPIF_STATE_DISABLE             = BIT(NAPI_STATE_DISABLE),
        NAPIF_STATE_NPSVC               = BIT(NAPI_STATE_NPSVC),
        NAPIF_STATE_LISTED              = BIT(NAPI_STATE_LISTED),
        NAPIF_STATE_NO_BUSY_POLL        = BIT(NAPI_STATE_NO_BUSY_POLL),
        NAPIF_STATE_IN_BUSY_POLL        = BIT(NAPI_STATE_IN_BUSY_POLL),
        NAPIF_STATE_PREFER_BUSY_POLL    = BIT(NAPI_STATE_PREFER_BUSY_POLL),
        NAPIF_STATE_THREADED            = BIT(NAPI_STATE_THREADED),
        NAPIF_STATE_SCHED_THREADED      = BIT(NAPI_STATE_SCHED_THREADED),
};

enum gro_result {
        GRO_MERGED,
        GRO_MERGED_FREE,
        GRO_HELD,
        GRO_NORMAL,
        GRO_CONSUMED,
};
typedef enum gro_result gro_result_t;

/*
 * enum rx_handler_result - Possible return values for rx_handlers.
 * @RX_HANDLER_CONSUMED: skb was consumed by rx_handler, do not process it
 * further.
 * @RX_HANDLER_ANOTHER: Do another round in receive path. This is indicated in
 * case skb->dev was changed by rx_handler.
 * @RX_HANDLER_EXACT: Force exact delivery, no wildcard.
 * @RX_HANDLER_PASS: Do nothing, pass the skb as if no rx_handler was called.
 *
 * rx_handlers are functions called from inside __netif_receive_skb(), to do
 * special processing of the skb, prior to delivery to protocol handlers.
 *
 * Currently, a net_device can only have a single rx_handler registered. Trying
 * to register a second rx_handler will return -EBUSY.
 *
 * To register a rx_handler on a net_device, use netdev_rx_handler_register().
 * To unregister a rx_handler on a net_device, use
 * netdev_rx_handler_unregister().
 *
 * Upon return, rx_handler is expected to tell __netif_receive_skb() what to
 * do with the skb.
 *
 * If the rx_handler consumed the skb in some way, it should return
 * RX_HANDLER_CONSUMED. This is appropriate when the rx_handler arranged for
 * the skb to be delivered in some other way.
 *
 * If the rx_handler changed skb->dev, to divert the skb to another
 * net_device, it should return RX_HANDLER_ANOTHER. The rx_handler for the
 * new device will be called if it exists.
 *
 * If the rx_handler decides the skb should be ignored, it should return
 * RX_HANDLER_EXACT. The skb will only be delivered to protocol handlers that
 * are registered on exact device (ptype->dev == skb->dev).
 *
 * If the rx_handler didn't change skb->dev, but wants the skb to be normally
 * delivered, it should return RX_HANDLER_PASS.
 *
 * A device without a registered rx_handler will behave as if rx_handler
 * returned RX_HANDLER_PASS.
 */

enum rx_handler_result {
        RX_HANDLER_CONSUMED,
        RX_HANDLER_ANOTHER,
        RX_HANDLER_EXACT,
        RX_HANDLER_PASS,
};
typedef enum rx_handler_result rx_handler_result_t;
typedef rx_handler_result_t rx_handler_func_t(struct sk_buff **pskb);

void __napi_schedule(struct napi_struct *n);
void __napi_schedule_irqoff(struct napi_struct *n);

static inline bool napi_disable_pending(struct napi_struct *n)
{
        return test_bit(NAPI_STATE_DISABLE, &n->state);
}

static inline bool napi_prefer_busy_poll(struct napi_struct *n)
{
        return test_bit(NAPI_STATE_PREFER_BUSY_POLL, &n->state);
}

bool napi_schedule_prep(struct napi_struct *n);

/**
 *      napi_schedule - schedule NAPI poll
 *      @n: NAPI context
 *
 * Schedule NAPI poll routine to be called if it is not already
 * running.
 */
static inline void napi_schedule(struct napi_struct *n)
{
        if (napi_schedule_prep(n))
                __napi_schedule(n);
}

/**
 *      napi_schedule_irqoff - schedule NAPI poll
 *      @n: NAPI context
 *
 * Variant of napi_schedule(), assuming hard irqs are masked.
 */
static inline void napi_schedule_irqoff(struct napi_struct *n)
{
        if (napi_schedule_prep(n))
                __napi_schedule_irqoff(n);
}

/* Try to reschedule poll. Called by dev->poll() after napi_complete().  */
static inline bool napi_reschedule(struct napi_struct *napi)
{
        if (napi_schedule_prep(napi)) {
                __napi_schedule(napi);
                return true;
        }
        return false;
}

bool napi_complete_done(struct napi_struct *n, int work_done);
/**
 *      napi_complete - NAPI processing complete
 *      @n: NAPI context
 *
 * Mark NAPI processing as complete.
 * Consider using napi_complete_done() instead.
 * Return false if device should avoid rearming interrupts.
 */
static inline bool napi_complete(struct napi_struct *n)
{
        return napi_complete_done(n, 0);
}

int dev_set_threaded(struct net_device *dev, bool threaded);

/**
 *      napi_disable - prevent NAPI from scheduling
 *      @n: NAPI context
 *
 * Stop NAPI from being scheduled on this context.
 * Waits till any outstanding processing completes.
 */
void napi_disable(struct napi_struct *n);

void napi_enable(struct napi_struct *n);

/**
 *      napi_synchronize - wait until NAPI is not running
 *      @n: NAPI context
 *
 * Wait until NAPI is done being scheduled on this context.
 * Waits till any outstanding processing completes but
 * does not disable future activations.
 */
static inline void napi_synchronize(const struct napi_struct *n)
{
        if (IS_ENABLED(CONFIG_SMP))
                while (test_bit(NAPI_STATE_SCHED, &n->state))
                        msleep(1);
        else
                barrier();
}

/**
 *      napi_if_scheduled_mark_missed - if napi is running, set the
 *      NAPIF_STATE_MISSED
 *      @n: NAPI context
 *
 * If napi is running, set the NAPIF_STATE_MISSED, and return true if
 * NAPI is scheduled.
 **/
static inline bool napi_if_scheduled_mark_missed(struct napi_struct *n)
{
        unsigned long val, new;

        do {
                val = READ_ONCE(n->state);
                if (val & NAPIF_STATE_DISABLE)
                        return true;

                if (!(val & NAPIF_STATE_SCHED))
                        return false;

                new = val | NAPIF_STATE_MISSED;
        } while (cmpxchg(&n->state, val, new) != val);

        return true;
}

enum netdev_queue_state_t {
        __QUEUE_STATE_DRV_XOFF,
        __QUEUE_STATE_STACK_XOFF,
        __QUEUE_STATE_FROZEN,
};

#define QUEUE_STATE_DRV_XOFF    (1 << __QUEUE_STATE_DRV_XOFF)
#define QUEUE_STATE_STACK_XOFF  (1 << __QUEUE_STATE_STACK_XOFF)
#define QUEUE_STATE_FROZEN      (1 << __QUEUE_STATE_FROZEN)

#define QUEUE_STATE_ANY_XOFF    (QUEUE_STATE_DRV_XOFF | QUEUE_STATE_STACK_XOFF)
#define QUEUE_STATE_ANY_XOFF_OR_FROZEN (QUEUE_STATE_ANY_XOFF | \
                                        QUEUE_STATE_FROZEN)
#define QUEUE_STATE_DRV_XOFF_OR_FROZEN (QUEUE_STATE_DRV_XOFF | \
                                        QUEUE_STATE_FROZEN)

/*
 * __QUEUE_STATE_DRV_XOFF is used by drivers to stop the transmit queue.  The
 * netif_tx_* functions below are used to manipulate this flag.  The
 * __QUEUE_STATE_STACK_XOFF flag is used by the stack to stop the transmit
 * queue independently.  The netif_xmit_*stopped functions below are called
 * to check if the queue has been stopped by the driver or stack (either
 * of the XOFF bits are set in the state).  Drivers should not need to call
 * netif_xmit*stopped functions, they should only be using netif_tx_*.
 */

struct netdev_queue {
/*
 * read-mostly part
 */
        struct net_device       *dev;
        struct Qdisc __rcu      *qdisc;
        struct Qdisc            *qdisc_sleeping;
#ifdef CONFIG_SYSFS
        struct kobject          kobj;
#endif
#if defined(CONFIG_XPS) && defined(CONFIG_NUMA)
        int                     numa_node;
#endif
        unsigned long           tx_maxrate;
        /*
         * Number of TX timeouts for this queue
         * (/sys/class/net/DEV/Q/trans_timeout)
         */
        unsigned long           trans_timeout;

        /* Subordinate device that the queue has been assigned to */
        struct net_device       *sb_dev;
#ifdef CONFIG_XDP_SOCKETS
        struct xsk_buff_pool    *pool;
#endif
/*
 * write-mostly part
 */
        spinlock_t              _xmit_lock ____cacheline_aligned_in_smp;
        int                     xmit_lock_owner;
        /*
         * Time (in jiffies) of last Tx
         */
        unsigned long           trans_start;

        unsigned long           state;

#ifdef CONFIG_BQL
        struct dql              dql;
#endif
} ____cacheline_aligned_in_smp;

extern int sysctl_fb_tunnels_only_for_init_net;
extern int sysctl_devconf_inherit_init_net;

/*
 * sysctl_fb_tunnels_only_for_init_net == 0 : For all netns
 *                                     == 1 : For initns only
 *                                     == 2 : For none.
 */
static inline bool net_has_fallback_tunnels(const struct net *net)
{
        return !IS_ENABLED(CONFIG_SYSCTL) ||
               !sysctl_fb_tunnels_only_for_init_net ||
               (net == &init_net && sysctl_fb_tunnels_only_for_init_net == 1);
}

static inline int netdev_queue_numa_node_read(const struct netdev_queue *q)
{
#if defined(CONFIG_XPS) && defined(CONFIG_NUMA)
        return q->numa_node;
#else
        return NUMA_NO_NODE;
#endif
}

static inline void netdev_queue_numa_node_write(struct netdev_queue *q, int node)
{
#if defined(CONFIG_XPS) && defined(CONFIG_NUMA)
        q->numa_node = node;
#endif
}

#ifdef CONFIG_RPS
/*
 * This structure holds an RPS map which can be of variable length.  The
 * map is an array of CPUs.
 */
struct rps_map {
        unsigned int len;
        struct rcu_head rcu;
        u16 cpus[];
};
#define RPS_MAP_SIZE(_num) (sizeof(struct rps_map) + ((_num) * sizeof(u16)))

/*
 * The rps_dev_flow structure contains the mapping of a flow to a CPU, the
 * tail pointer for that CPU's input queue at the time of last enqueue, and
 * a hardware filter index.
 */
struct rps_dev_flow {
        u16 cpu;
        u16 filter;
        unsigned int last_qtail;
};
#define RPS_NO_FILTER 0xffff

/*
 * The rps_dev_flow_table structure contains a table of flow mappings.
 */
struct rps_dev_flow_table {
        unsigned int mask;
        struct rcu_head rcu;
        struct rps_dev_flow flows[];
};
#define RPS_DEV_FLOW_TABLE_SIZE(_num) (sizeof(struct rps_dev_flow_table) + \
    ((_num) * sizeof(struct rps_dev_flow)))

/*
 * The rps_sock_flow_table contains mappings of flows to the last CPU
 * on which they were processed by the application (set in recvmsg).
 * Each entry is a 32bit value. Upper part is the high-order bits
 * of flow hash, lower part is CPU number.
 * rps_cpu_mask is used to partition the space, depending on number of
 * possible CPUs : rps_cpu_mask = roundup_pow_of_two(nr_cpu_ids) - 1
 * For example, if 64 CPUs are possible, rps_cpu_mask = 0x3f,
 * meaning we use 32-6=26 bits for the hash.
 */
struct rps_sock_flow_table {
        u32     mask;

        u32     ents[] ____cacheline_aligned_in_smp;
};
#define RPS_SOCK_FLOW_TABLE_SIZE(_num) (offsetof(struct rps_sock_flow_table, ents[_num]))

#define RPS_NO_CPU 0xffff

extern u32 rps_cpu_mask;
extern struct rps_sock_flow_table __rcu *rps_sock_flow_table;

static inline void rps_record_sock_flow(struct rps_sock_flow_table *table,
                                        u32 hash)
{
        if (table && hash) {
                unsigned int index = hash & table->mask;
                u32 val = hash & ~rps_cpu_mask;

                /* We only give a hint, preemption can change CPU under us */
                val |= raw_smp_processor_id();

                if (table->ents[index] != val)
                        table->ents[index] = val;
        }
}

#ifdef CONFIG_RFS_ACCEL
bool rps_may_expire_flow(struct net_device *dev, u16 rxq_index, u32 flow_id,
                         u16 filter_id);
#endif
#endif /* CONFIG_RPS */

/* This structure contains an instance of an RX queue. */
struct netdev_rx_queue {
        struct xdp_rxq_info             xdp_rxq;
#ifdef CONFIG_RPS
        struct rps_map __rcu            *rps_map;
        struct rps_dev_flow_table __rcu *rps_flow_table;
#endif
        struct kobject                  kobj;
        struct net_device               *dev;
#ifdef CONFIG_XDP_SOCKETS
        struct xsk_buff_pool            *pool;
#endif
} ____cacheline_aligned_in_smp;

/*
 * RX queue sysfs structures and functions.
 */
struct rx_queue_attribute {
        struct attribute attr;
        ssize_t (*show)(struct netdev_rx_queue *queue, char *buf);
        ssize_t (*store)(struct netdev_rx_queue *queue,
                         const char *buf, size_t len);
};

/* XPS map type and offset of the xps map within net_device->xps_maps[]. */
enum xps_map_type {
        XPS_CPUS = 0,
        XPS_RXQS,
        XPS_MAPS_MAX,
};

#ifdef CONFIG_XPS
/*
 * This structure holds an XPS map which can be of variable length.  The
 * map is an array of queues.
 */
struct xps_map {
        unsigned int len;
        unsigned int alloc_len;
        struct rcu_head rcu;
        u16 queues[];
};
#define XPS_MAP_SIZE(_num) (sizeof(struct xps_map) + ((_num) * sizeof(u16)))
#define XPS_MIN_MAP_ALLOC ((L1_CACHE_ALIGN(offsetof(struct xps_map, queues[1])) \
       - sizeof(struct xps_map)) / sizeof(u16))

/*
 * This structure holds all XPS maps for device.  Maps are indexed by CPU.
 *
 * We keep track of the number of cpus/rxqs used when the struct is allocated,
 * in nr_ids. This will help not accessing out-of-bound memory.
 *
 * We keep track of the number of traffic classes used when the struct is
 * allocated, in num_tc. This will be used to navigate the maps, to ensure we're
 * not crossing its upper bound, as the original dev->num_tc can be updated in
 * the meantime.
 */
struct xps_dev_maps {
        struct rcu_head rcu;
        unsigned int nr_ids;
        s16 num_tc;
        struct xps_map __rcu *attr_map[]; /* Either CPUs map or RXQs map */
};

#define XPS_CPU_DEV_MAPS_SIZE(_tcs) (sizeof(struct xps_dev_maps) +      \
        (nr_cpu_ids * (_tcs) * sizeof(struct xps_map *)))

#define XPS_RXQ_DEV_MAPS_SIZE(_tcs, _rxqs) (sizeof(struct xps_dev_maps) +\
        (_rxqs * (_tcs) * sizeof(struct xps_map *)))

#endif /* CONFIG_XPS */

#define TC_MAX_QUEUE    16
#define TC_BITMASK      15
/* HW offloaded queuing disciplines txq count and offset maps */
struct netdev_tc_txq {
        u16 count;
        u16 offset;
};

#if defined(CONFIG_FCOE) || defined(CONFIG_FCOE_MODULE)
/*
 * This structure is to hold information about the device
 * configured to run FCoE protocol stack.
 */
struct netdev_fcoe_hbainfo {
        char    manufacturer[64];
        char    serial_number[64];
        char    hardware_version[64];
        char    driver_version[64];
        char    optionrom_version[64];
        char    firmware_version[64];
        char    model[256];
        char    model_description[256];
};
#endif

#define MAX_PHYS_ITEM_ID_LEN 32

/* This structure holds a unique identifier to identify some
 * physical item (port for example) used by a netdevice.
 */
struct netdev_phys_item_id {
        unsigned char id[MAX_PHYS_ITEM_ID_LEN];
        unsigned char id_len;
};

static inline bool netdev_phys_item_id_same(struct netdev_phys_item_id *a,
                                            struct netdev_phys_item_id *b)
{
        return a->id_len == b->id_len &&
               memcmp(a->id, b->id, a->id_len) == 0;
}

typedef u16 (*select_queue_fallback_t)(struct net_device *dev,
                                       struct sk_buff *skb,
                                       struct net_device *sb_dev);

enum net_device_path_type {
        DEV_PATH_ETHERNET = 0,
        DEV_PATH_VLAN,
        DEV_PATH_BRIDGE,
        DEV_PATH_PPPOE,
        DEV_PATH_DSA,
};

struct net_device_path {
        enum net_device_path_type       type;
        const struct net_device         *dev;
        union {
                struct {
                        u16             id;
                        __be16          proto;
                        u8              h_dest[ETH_ALEN];
                } encap;
                struct {
                        enum {
                                DEV_PATH_BR_VLAN_KEEP,
                                DEV_PATH_BR_VLAN_TAG,
                                DEV_PATH_BR_VLAN_UNTAG,
                                DEV_PATH_BR_VLAN_UNTAG_HW,
                        }               vlan_mode;
                        u16             vlan_id;
                        __be16          vlan_proto;
                } bridge;
                struct {
                        int port;
                        u16 proto;
                } dsa;
        };
};

#define NET_DEVICE_PATH_STACK_MAX       5
#define NET_DEVICE_PATH_VLAN_MAX        2

struct net_device_path_stack {
        int                     num_paths;
        struct net_device_path  path[NET_DEVICE_PATH_STACK_MAX];
};

struct net_device_path_ctx {
        const struct net_device *dev;
        const u8                *daddr;

        int                     num_vlans;
        struct {
                u16             id;
                __be16          proto;
        } vlan[NET_DEVICE_PATH_VLAN_MAX];
};

enum tc_setup_type {
        TC_SETUP_QDISC_MQPRIO,
        TC_SETUP_CLSU32,
        TC_SETUP_CLSFLOWER,
        TC_SETUP_CLSMATCHALL,
        TC_SETUP_CLSBPF,
        TC_SETUP_BLOCK,
        TC_SETUP_QDISC_CBS,
        TC_SETUP_QDISC_RED,
        TC_SETUP_QDISC_PRIO,
        TC_SETUP_QDISC_MQ,
        TC_SETUP_QDISC_ETF,
        TC_SETUP_ROOT_QDISC,
        TC_SETUP_QDISC_GRED,
        TC_SETUP_QDISC_TAPRIO,
        TC_SETUP_FT,
        TC_SETUP_QDISC_ETS,
        TC_SETUP_QDISC_TBF,
        TC_SETUP_QDISC_FIFO,
        TC_SETUP_QDISC_HTB,
};

/* These structures hold the attributes of bpf state that are being passed
 * to the netdevice through the bpf op.
 */
enum bpf_netdev_command {
        /* Set or clear a bpf program used in the earliest stages of packet
         * rx. The prog will have been loaded as BPF_PROG_TYPE_XDP. The callee
         * is responsible for calling bpf_prog_put on any old progs that are
         * stored. In case of error, the callee need not release the new prog
         * reference, but on success it takes ownership and must bpf_prog_put
         * when it is no longer used.
         */
        XDP_SETUP_PROG,
        XDP_SETUP_PROG_HW,
        /* BPF program for offload callbacks, invoked at program load time. */
        BPF_OFFLOAD_MAP_ALLOC,
        BPF_OFFLOAD_MAP_FREE,
        XDP_SETUP_XSK_POOL,
};

struct bpf_prog_offload_ops;
struct netlink_ext_ack;
struct xdp_umem;
struct xdp_dev_bulk_queue;
struct bpf_xdp_link;

enum bpf_xdp_mode {
        XDP_MODE_SKB = 0,
        XDP_MODE_DRV = 1,
        XDP_MODE_HW = 2,
        __MAX_XDP_MODE
};

struct bpf_xdp_entity {
        struct bpf_prog *prog;
        struct bpf_xdp_link *link;
};

struct netdev_bpf {
        enum bpf_netdev_command command;
        union {
                /* XDP_SETUP_PROG */
                struct {
                        u32 flags;
                        struct bpf_prog *prog;
                        struct netlink_ext_ack *extack;
                };
                /* BPF_OFFLOAD_MAP_ALLOC, BPF_OFFLOAD_MAP_FREE */
                struct {
                        struct bpf_offloaded_map *offmap;
                };
                /* XDP_SETUP_XSK_POOL */
                struct {
                        struct xsk_buff_pool *pool;
                        u16 queue_id;
                } xsk;
        };
};

/* Flags for ndo_xsk_wakeup. */
#define XDP_WAKEUP_RX (1 << 0)
#define XDP_WAKEUP_TX (1 << 1)

#ifdef CONFIG_XFRM_OFFLOAD
struct xfrmdev_ops {
        int     (*xdo_dev_state_add) (struct xfrm_state *x);
        void    (*xdo_dev_state_delete) (struct xfrm_state *x);
        void    (*xdo_dev_state_free) (struct xfrm_state *x);
        bool    (*xdo_dev_offload_ok) (struct sk_buff *skb,
                                       struct xfrm_state *x);
        void    (*xdo_dev_state_advance_esn) (struct xfrm_state *x);
};
#endif

struct dev_ifalias {
        struct rcu_head rcuhead;
        char ifalias[];
};

struct devlink;
struct tlsdev_ops;

struct netdev_name_node {
        struct hlist_node hlist;
        struct list_head list;
        struct net_device *dev;
        const char *name;
};

int netdev_name_node_alt_create(struct net_device *dev, const char *name);
int netdev_name_node_alt_destroy(struct net_device *dev, const char *name);

struct netdev_net_notifier {
        struct list_head list;
        struct notifier_block *nb;
};

/*
 * This structure defines the management hooks for network devices.
 * The following hooks can be defined; unless noted otherwise, they are
 * optional and can be filled with a null pointer.
 *
 * int (*ndo_init)(struct net_device *dev);
 *     This function is called once when a network device is registered.
 *     The network device can use this for any late stage initialization
 *     or semantic validation. It can fail with an error code which will
 *     be propagated back to register_netdev.
 *
 * void (*ndo_uninit)(struct net_device *dev);
 *     This function is called when device is unregistered or when registration
 *     fails. It is not called if init fails.
 *
 * int (*ndo_open)(struct net_device *dev);
 *     This function is called when a network device transitions to the up
 *     state.
 *
 * int (*ndo_stop)(struct net_device *dev);
 *     This function is called when a network device transitions to the down
 *     state.
 *
 * netdev_tx_t (*ndo_start_xmit)(struct sk_buff *skb,
 *                               struct net_device *dev);
 *      Called when a packet needs to be transmitted.
 *      Returns NETDEV_TX_OK.  Can return NETDEV_TX_BUSY, but you should stop
 *      the queue before that can happen; it's for obsolete devices and weird
 *      corner cases, but the stack really does a non-trivial amount
 *      of useless work if you return NETDEV_TX_BUSY.
 *      Required; cannot be NULL.
 *
 * netdev_features_t (*ndo_features_check)(struct sk_buff *skb,
 *                                         struct net_device *dev
 *                                         netdev_features_t features);
 *      Called by core transmit path to determine if device is capable of
 *      performing offload operations on a given packet. This is to give
 *      the device an opportunity to implement any restrictions that cannot
 *      be otherwise expressed by feature flags. The check is called with
 *      the set of features that the stack has calculated and it returns
 *      those the driver believes to be appropriate.
 *
 * u16 (*ndo_select_queue)(struct net_device *dev, struct sk_buff *skb,
 *                         struct net_device *sb_dev);
 *      Called to decide which queue to use when device supports multiple
 *      transmit queues.
 *
 * void (*ndo_change_rx_flags)(struct net_device *dev, int flags);
 *      This function is called to allow device receiver to make
 *      changes to configuration when multicast or promiscuous is enabled.
 *
 * void (*ndo_set_rx_mode)(struct net_device *dev);
 *      This function is called device changes address list filtering.
 *      If driver handles unicast address filtering, it should set
 *      IFF_UNICAST_FLT in its priv_flags.
 *
 * int (*ndo_set_mac_address)(struct net_device *dev, void *addr);
 *      This function  is called when the Media Access Control address
 *      needs to be changed. If this interface is not defined, the
 *      MAC address can not be changed.
 *
 * int (*ndo_validate_addr)(struct net_device *dev);
 *      Test if Media Access Control address is valid for the device.
 *
 * int (*ndo_do_ioctl)(struct net_device *dev, struct ifreq *ifr, int cmd);
 *      Old-style ioctl entry point. This is used internally by the
 *      appletalk and ieee802154 subsystems but is no longer called by
 *      the device ioctl handler.
 *
 * int (*ndo_siocbond)(struct net_device *dev, struct ifreq *ifr, int cmd);
 *      Used by the bonding driver for its device specific ioctls:
 *      SIOCBONDENSLAVE, SIOCBONDRELEASE, SIOCBONDSETHWADDR, SIOCBONDCHANGEACTIVE,
 *      SIOCBONDSLAVEINFOQUERY, and SIOCBONDINFOQUERY
 *
 * * int (*ndo_eth_ioctl)(struct net_device *dev, struct ifreq *ifr, int cmd);
 *      Called for ethernet specific ioctls: SIOCGMIIPHY, SIOCGMIIREG,
 *      SIOCSMIIREG, SIOCSHWTSTAMP and SIOCGHWTSTAMP.
 *
 * int (*ndo_set_config)(struct net_device *dev, struct ifmap *map);
 *      Used to set network devices bus interface parameters. This interface
 *      is retained for legacy reasons; new devices should use the bus
 *      interface (PCI) for low level management.
 *
 * int (*ndo_change_mtu)(struct net_device *dev, int new_mtu);
 *      Called when a user wants to change the Maximum Transfer Unit
 *      of a device.
 *
 * void (*ndo_tx_timeout)(struct net_device *dev, unsigned int txqueue);
 *      Callback used when the transmitter has not made any progress
 *      for dev->watchdog ticks.
 *
 * void (*ndo_get_stats64)(struct net_device *dev,
 *                         struct rtnl_link_stats64 *storage);
 * struct net_device_stats* (*ndo_get_stats)(struct net_device *dev);
 *      Called when a user wants to get the network device usage
 *      statistics. Drivers must do one of the following:
 *      1. Define @ndo_get_stats64 to fill in a zero-initialised
 *         rtnl_link_stats64 structure passed by the caller.
 *      2. Define @ndo_get_stats to update a net_device_stats structure
 *         (which should normally be dev->stats) and return a pointer to
 *         it. The structure may be changed asynchronously only if each
 *         field is written atomically.
 *      3. Update dev->stats asynchronously and atomically, and define
 *         neither operation.
 *
 * bool (*ndo_has_offload_stats)(const struct net_device *dev, int attr_id)
 *      Return true if this device supports offload stats of this attr_id.
 *
 * int (*ndo_get_offload_stats)(int attr_id, const struct net_device *dev,
 *      void *attr_data)
 *      Get statistics for offload operations by attr_id. Write it into the
 *      attr_data pointer.
 *
 * int (*ndo_vlan_rx_add_vid)(struct net_device *dev, __be16 proto, u16 vid);
 *      If device supports VLAN filtering this function is called when a
 *      VLAN id is registered.
 *
 * int (*ndo_vlan_rx_kill_vid)(struct net_device *dev, __be16 proto, u16 vid);
 *      If device supports VLAN filtering this function is called when a
 *      VLAN id is unregistered.
 *
 * void (*ndo_poll_controller)(struct net_device *dev);
 *
 *      SR-IOV management functions.
 * int (*ndo_set_vf_mac)(struct net_device *dev, int vf, u8* mac);
 * int (*ndo_set_vf_vlan)(struct net_device *dev, int vf, u16 vlan,
 *                        u8 qos, __be16 proto);
 * int (*ndo_set_vf_rate)(struct net_device *dev, int vf, int min_tx_rate,
 *                        int max_tx_rate);
 * int (*ndo_set_vf_spoofchk)(struct net_device *dev, int vf, bool setting);
 * int (*ndo_set_vf_trust)(struct net_device *dev, int vf, bool setting);
 * int (*ndo_get_vf_config)(struct net_device *dev,
 *                          int vf, struct ifla_vf_info *ivf);
 * int (*ndo_set_vf_link_state)(struct net_device *dev, int vf, int link_state);
 * int (*ndo_set_vf_port)(struct net_device *dev, int vf,
 *                        struct nlattr *port[]);
 *
 *      Enable or disable the VF ability to query its RSS Redirection Table and
 *      Hash Key. This is needed since on some devices VF share this information
 *      with PF and querying it may introduce a theoretical security risk.
 * int (*ndo_set_vf_rss_query_en)(struct net_device *dev, int vf, bool setting);
 * int (*ndo_get_vf_port)(struct net_device *dev, int vf, struct sk_buff *skb);
 * int (*ndo_setup_tc)(struct net_device *dev, enum tc_setup_type type,
 *                     void *type_data);
 *      Called to setup any 'tc' scheduler, classifier or action on @dev.
 *      This is always called from the stack with the rtnl lock held and netif
 *      tx queues stopped. This allows the netdevice to perform queue
 *      management safely.
 *
 *      Fiber Channel over Ethernet (FCoE) offload functions.
 * int (*ndo_fcoe_enable)(struct net_device *dev);
 *      Called when the FCoE protocol stack wants to start using LLD for FCoE
 *      so the underlying device can perform whatever needed configuration or
 *      initialization to support acceleration of FCoE traffic.
 *
 * int (*ndo_fcoe_disable)(struct net_device *dev);
 *      Called when the FCoE protocol stack wants to stop using LLD for FCoE
 *      so the underlying device can perform whatever needed clean-ups to
 *      stop supporting acceleration of FCoE traffic.
 *
 * int (*ndo_fcoe_ddp_setup)(struct net_device *dev, u16 xid,
 *                           struct scatterlist *sgl, unsigned int sgc);
 *      Called when the FCoE Initiator wants to initialize an I/O that
 *      is a possible candidate for Direct Data Placement (DDP). The LLD can
 *      perform necessary setup and returns 1 to indicate the device is set up
 *      successfully to perform DDP on this I/O, otherwise this returns 0.
 *
 * int (*ndo_fcoe_ddp_done)(struct net_device *dev,  u16 xid);
 *      Called when the FCoE Initiator/Target is done with the DDPed I/O as
 *      indicated by the FC exchange id 'xid', so the underlying device can
 *      clean up and reuse resources for later DDP requests.
 *
 * int (*ndo_fcoe_ddp_target)(struct net_device *dev, u16 xid,
 *                            struct scatterlist *sgl, unsigned int sgc);
 *      Called when the FCoE Target wants to initialize an I/O that
 *      is a possible candidate for Direct Data Placement (DDP). The LLD can
 *      perform necessary setup and returns 1 to indicate the device is set up
 *      successfully to perform DDP on this I/O, otherwise this returns 0.
 *
 * int (*ndo_fcoe_get_hbainfo)(struct net_device *dev,
 *                             struct netdev_fcoe_hbainfo *hbainfo);
 *      Called when the FCoE Protocol stack wants information on the underlying
 *      device. This information is utilized by the FCoE protocol stack to
 *      register attributes with Fiber Channel management service as per the
 *      FC-GS Fabric Device Management Information(FDMI) specification.
 *
 * int (*ndo_fcoe_get_wwn)(struct net_device *dev, u64 *wwn, int type);
 *      Called when the underlying device wants to override default World Wide
 *      Name (WWN) generation mechanism in FCoE protocol stack to pass its own
 *      World Wide Port Name (WWPN) or World Wide Node Name (WWNN) to the FCoE
 *      protocol stack to use.
 *
 *      RFS acceleration.
 * int (*ndo_rx_flow_steer)(struct net_device *dev, const struct sk_buff *skb,
 *                          u16 rxq_index, u32 flow_id);
 *      Set hardware filter for RFS.  rxq_index is the target queue index;
 *      flow_id is a flow ID to be passed to rps_may_expire_flow() later.
 *      Return the filter ID on success, or a negative error code.
 *
 *      Slave management functions (for bridge, bonding, etc).
 * int (*ndo_add_slave)(struct net_device *dev, struct net_device *slave_dev);
 *      Called to make another netdev an underling.
 *
 * int (*ndo_del_slave)(struct net_device *dev, struct net_device *slave_dev);
 *      Called to release previously enslaved netdev.
 *
 * struct net_device *(*ndo_get_xmit_slave)(struct net_device *dev,
 *                                          struct sk_buff *skb,
 *                                          bool all_slaves);
 *      Get the xmit slave of master device. If all_slaves is true, function
 *      assume all the slaves can transmit.
 *
 *      Feature/offload setting functions.
 * netdev_features_t (*ndo_fix_features)(struct net_device *dev,
 *              netdev_features_t features);
 *      Adjusts the requested feature flags according to device-specific
 *      constraints, and returns the resulting flags. Must not modify
 *      the device state.
 *
 * int (*ndo_set_features)(struct net_device *dev, netdev_features_t features);
 *      Called to update device configuration to new features. Passed
 *      feature set might be less than what was returned by ndo_fix_features()).
 *      Must return >0 or -errno if it changed dev->features itself.
 *
 * int (*ndo_fdb_add)(struct ndmsg *ndm, struct nlattr *tb[],
 *                    struct net_device *dev,
 *                    const unsigned char *addr, u16 vid, u16 flags,
 *                    struct netlink_ext_ack *extack);
 *      Adds an FDB entry to dev for addr.
 * int (*ndo_fdb_del)(struct ndmsg *ndm, struct nlattr *tb[],
 *                    struct net_device *dev,
 *                    const unsigned char *addr, u16 vid)
 *      Deletes the FDB entry from dev coresponding to addr.
 * int (*ndo_fdb_dump)(struct sk_buff *skb, struct netlink_callback *cb,
 *                     struct net_device *dev, struct net_device *filter_dev,
 *                     int *idx)
 *      Used to add FDB entries to dump requests. Implementers should add
 *      entries to skb and update idx with the number of entries.
 *
 * int (*ndo_bridge_setlink)(struct net_device *dev, struct nlmsghdr *nlh,
 *                           u16 flags, struct netlink_ext_ack *extack)
 * int (*ndo_bridge_getlink)(struct sk_buff *skb, u32 pid, u32 seq,
 *                           struct net_device *dev, u32 filter_mask,
 *                           int nlflags)
 * int (*ndo_bridge_dellink)(struct net_device *dev, struct nlmsghdr *nlh,
 *                           u16 flags);
 *
 * int (*ndo_change_carrier)(struct net_device *dev, bool new_carrier);
 *      Called to change device carrier. Soft-devices (like dummy, team, etc)
 *      which do not represent real hardware may define this to allow their
 *      userspace components to manage their virtual carrier state. Devices
 *      that determine carrier state from physical hardware properties (eg
 *      network cables) or protocol-dependent mechanisms (eg
 *      USB_CDC_NOTIFY_NETWORK_CONNECTION) should NOT implement this function.
 *
 * int (*ndo_get_phys_port_id)(struct net_device *dev,
 *                             struct netdev_phys_item_id *ppid);
 *      Called to get ID of physical port of this device. If driver does
 *      not implement this, it is assumed that the hw is not able to have
 *      multiple net devices on single physical port.
 *
 * int (*ndo_get_port_parent_id)(struct net_device *dev,
 *                               struct netdev_phys_item_id *ppid)
 *      Called to get the parent ID of the physical port of this device.
 *
 * void* (*ndo_dfwd_add_station)(struct net_device *pdev,
 *                               struct net_device *dev)
 *      Called by upper layer devices to accelerate switching or other
 *      station functionality into hardware. 'pdev is the lowerdev
 *      to use for the offload and 'dev' is the net device that will
 *      back the offload. Returns a pointer to the private structure
 *      the upper layer will maintain.
 * void (*ndo_dfwd_del_station)(struct net_device *pdev, void *priv)
 *      Called by upper layer device to delete the station created
 *      by 'ndo_dfwd_add_station'. 'pdev' is the net device backing
 *      the station and priv is the structure returned by the add
 *      operation.
 * int (*ndo_set_tx_maxrate)(struct net_device *dev,
 *                           int queue_index, u32 maxrate);
 *      Called when a user wants to set a max-rate limitation of specific
 *      TX queue.
 * int (*ndo_get_iflink)(const struct net_device *dev);
 *      Called to get the iflink value of this device.
 * void (*ndo_change_proto_down)(struct net_device *dev,
 *                               bool proto_down);
 *      This function is used to pass protocol port error state information
 *      to the switch driver. The switch driver can react to the proto_down
 *      by doing a phys down on the associated switch port.
 * int (*ndo_fill_metadata_dst)(struct net_device *dev, struct sk_buff *skb);
 *      This function is used to get egress tunnel information for given skb.
 *      This is useful for retrieving outer tunnel header parameters while
 *      sampling packet.
 * void (*ndo_set_rx_headroom)(struct net_device *dev, int needed_headroom);
 *      This function is used to specify the headroom that the skb must
 *      consider when allocation skb during packet reception. Setting
 *      appropriate rx headroom value allows avoiding skb head copy on
 *      forward. Setting a negative value resets the rx headroom to the
 *      default value.
 * int (*ndo_bpf)(struct net_device *dev, struct netdev_bpf *bpf);
 *      This function is used to set or query state related to XDP on the
 *      netdevice and manage BPF offload. See definition of
 *      enum bpf_netdev_command for details.
 * int (*ndo_xdp_xmit)(struct net_device *dev, int n, struct xdp_frame **xdp,
 *                      u32 flags);
 *      This function is used to submit @n XDP packets for transmit on a
 *      netdevice. Returns number of frames successfully transmitted, frames
 *      that got dropped are freed/returned via xdp_return_frame().
 *      Returns negative number, means general error invoking ndo, meaning
 *      no frames were xmit'ed and core-caller will free all frames.
 * struct net_device *(*ndo_xdp_get_xmit_slave)(struct net_device *dev,
 *                                              struct xdp_buff *xdp);
 *      Get the xmit slave of master device based on the xdp_buff.
 * int (*ndo_xsk_wakeup)(struct net_device *dev, u32 queue_id, u32 flags);
 *      This function is used to wake up the softirq, ksoftirqd or kthread
 *      responsible for sending and/or receiving packets on a specific
 *      queue id bound to an AF_XDP socket. The flags field specifies if
 *      only RX, only Tx, or both should be woken up using the flags
 *      XDP_WAKEUP_RX and XDP_WAKEUP_TX.
 * struct devlink_port *(*ndo_get_devlink_port)(struct net_device *dev);
 *      Get devlink port instance associated with a given netdev.
 *      Called with a reference on the netdevice and devlink locks only,
 *      rtnl_lock is not held.
 * int (*ndo_tunnel_ctl)(struct net_device *dev, struct ip_tunnel_parm *p,
 *                       int cmd);
 *      Add, change, delete or get information on an IPv4 tunnel.
 * struct net_device *(*ndo_get_peer_dev)(struct net_device *dev);
 *      If a device is paired with a peer device, return the peer instance.
 *      The caller must be under RCU read context.
 * int (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx, struct net_device_path *path);
 *     Get the forwarding path to reach the real device from the HW destination address
 */
struct net_device_ops {
        int                     (*ndo_init)(struct net_device *dev);
        void                    (*ndo_uninit)(struct net_device *dev);
        int                     (*ndo_open)(struct net_device *dev);
        int                     (*ndo_stop)(struct net_device *dev);
        netdev_tx_t             (*ndo_start_xmit)(struct sk_buff *skb,
                                                  struct net_device *dev);
        netdev_features_t       (*ndo_features_check)(struct sk_buff *skb,
                                                      struct net_device *dev,
                                                      netdev_features_t features);
        u16                     (*ndo_select_queue)(struct net_device *dev,
                                                    struct sk_buff *skb,
                                                    struct net_device *sb_dev);
        void                    (*ndo_change_rx_flags)(struct net_device *dev,
                                                       int flags);
        void                    (*ndo_set_rx_mode)(struct net_device *dev);
        int                     (*ndo_set_mac_address)(struct net_device *dev,
                                                       void *addr);
        int                     (*ndo_validate_addr)(struct net_device *dev);
        int                     (*ndo_do_ioctl)(struct net_device *dev,
                                                struct ifreq *ifr, int cmd);
        int                     (*ndo_eth_ioctl)(struct net_device *dev,
                                                 struct ifreq *ifr, int cmd);
        int                     (*ndo_siocbond)(struct net_device *dev,
                                                struct ifreq *ifr, int cmd);
        int                     (*ndo_siocwandev)(struct net_device *dev,
                                                  struct if_settings *ifs);
        int                     (*ndo_siocdevprivate)(struct net_device *dev,
                                                      struct ifreq *ifr,
                                                      void __user *data, int cmd);
        int                     (*ndo_set_config)(struct net_device *dev,
                                                  struct ifmap *map);
        int                     (*ndo_change_mtu)(struct net_device *dev,
                                                  int new_mtu);
        int                     (*ndo_neigh_setup)(struct net_device *dev,
                                                   struct neigh_parms *);
        void                    (*ndo_tx_timeout) (struct net_device *dev,
                                                   unsigned int txqueue);

        void                    (*ndo_get_stats64)(struct net_device *dev,
                                                   struct rtnl_link_stats64 *storage);
        bool                    (*ndo_has_offload_stats)(const struct net_device *dev, int attr_id);
        int                     (*ndo_get_offload_stats)(int attr_id,
                                                         const struct net_device *dev,
                                                         void *attr_data);
        struct net_device_stats* (*ndo_get_stats)(struct net_device *dev);

        int                     (*ndo_vlan_rx_add_vid)(struct net_device *dev,
                                                       __be16 proto, u16 vid);
        int                     (*ndo_vlan_rx_kill_vid)(struct net_device *dev,
                                                        __be16 proto, u16 vid);
#ifdef CONFIG_NET_POLL_CONTROLLER
        void                    (*ndo_poll_controller)(struct net_device *dev);
        int                     (*ndo_netpoll_setup)(struct net_device *dev,
                                                     struct netpoll_info *info);
        void                    (*ndo_netpoll_cleanup)(struct net_device *dev);
#endif
        int                     (*ndo_set_vf_mac)(struct net_device *dev,
                                                  int queue, u8 *mac);
        int                     (*ndo_set_vf_vlan)(struct net_device *dev,
                                                   int queue, u16 vlan,
                                                   u8 qos, __be16 proto);
        int                     (*ndo_set_vf_rate)(struct net_device *dev,
                                                   int vf, int min_tx_rate,
                                                   int max_tx_rate);
        int                     (*ndo_set_vf_spoofchk)(struct net_device *dev,
                                                       int vf, bool setting);
        int                     (*ndo_set_vf_trust)(struct net_device *dev,
                                                    int vf, bool setting);
        int                     (*ndo_get_vf_config)(struct net_device *dev,
                                                     int vf,
                                                     struct ifla_vf_info *ivf);
        int                     (*ndo_set_vf_link_state)(struct net_device *dev,
                                                         int vf, int link_state);
        int                     (*ndo_get_vf_stats)(struct net_device *dev,
                                                    int vf,
                                                    struct ifla_vf_stats
                                                    *vf_stats);
        int                     (*ndo_set_vf_port)(struct net_device *dev,
                                                   int vf,
                                                   struct nlattr *port[]);
        int                     (*ndo_get_vf_port)(struct net_device *dev,
                                                   int vf, struct sk_buff *skb);
        int                     (*ndo_get_vf_guid)(struct net_device *dev,
                                                   int vf,
                                                   struct ifla_vf_guid *node_guid,
                                                   struct ifla_vf_guid *port_guid);
        int                     (*ndo_set_vf_guid)(struct net_device *dev,
                                                   int vf, u64 guid,
                                                   int guid_type);
        int                     (*ndo_set_vf_rss_query_en)(
                                                   struct net_device *dev,
                                                   int vf, bool setting);
        int                     (*ndo_setup_tc)(struct net_device *dev,
                                                enum tc_setup_type type,
                                                void *type_data);
#if IS_ENABLED(CONFIG_FCOE)
        int                     (*ndo_fcoe_enable)(struct net_device *dev);
        int                     (*ndo_fcoe_disable)(struct net_device *dev);
        int                     (*ndo_fcoe_ddp_setup)(struct net_device *dev,
                                                      u16 xid,
                                                      struct scatterlist *sgl,
                                                      unsigned int sgc);
        int                     (*ndo_fcoe_ddp_done)(struct net_device *dev,
                                                     u16 xid);
        int                     (*ndo_fcoe_ddp_target)(struct net_device *dev,
                                                       u16 xid,
                                                       struct scatterlist *sgl,
                                                       unsigned int sgc);
        int                     (*ndo_fcoe_get_hbainfo)(struct net_device *dev,
                                                        struct netdev_fcoe_hbainfo *hbainfo);
#endif

#if IS_ENABLED(CONFIG_LIBFCOE)
#define NETDEV_FCOE_WWNN 0
#define NETDEV_FCOE_WWPN 1
        int                     (*ndo_fcoe_get_wwn)(struct net_device *dev,
                                                    u64 *wwn, int type);
#endif

#ifdef CONFIG_RFS_ACCEL
        int                     (*ndo_rx_flow_steer)(struct net_device *dev,
                                                     const struct sk_buff *skb,
                                                     u16 rxq_index,
                                                     u32 flow_id);
#endif
        int                     (*ndo_add_slave)(struct net_device *dev,
                                                 struct net_device *slave_dev,
                                                 struct netlink_ext_ack *extack);
        int                     (*ndo_del_slave)(struct net_device *dev,
                                                 struct net_device *slave_dev);
        struct net_device*      (*ndo_get_xmit_slave)(struct net_device *dev,
                                                      struct sk_buff *skb,
                                                      bool all_slaves);
        struct net_device*      (*ndo_sk_get_lower_dev)(struct net_device *dev,
                                                        struct sock *sk);
        netdev_features_t       (*ndo_fix_features)(struct net_device *dev,
                                                    netdev_features_t features);
        int                     (*ndo_set_features)(struct net_device *dev,
                                                    netdev_features_t features);
        int                     (*ndo_neigh_construct)(struct net_device *dev,
                                                       struct neighbour *n);
        void                    (*ndo_neigh_destroy)(struct net_device *dev,
                                                     struct neighbour *n);

        int                     (*ndo_fdb_add)(struct ndmsg *ndm,
                                               struct nlattr *tb[],
                                               struct net_device *dev,
                                               const unsigned char *addr,
                                               u16 vid,
                                               u16 flags,
                                               struct netlink_ext_ack *extack);
        int                     (*ndo_fdb_del)(struct ndmsg *ndm,
                                               struct nlattr *tb[],
                                               struct net_device *dev,
                                               const unsigned char *addr,
                                               u16 vid);
        int                     (*ndo_fdb_dump)(struct sk_buff *skb,
                                                struct netlink_callback *cb,
                                                struct net_device *dev,
                                                struct net_device *filter_dev,
                                                int *idx);
        int                     (*ndo_fdb_get)(struct sk_buff *skb,
                                               struct nlattr *tb[],
                                               struct net_device *dev,
                                               const unsigned char *addr,
                                               u16 vid, u32 portid, u32 seq,
                                               struct netlink_ext_ack *extack);
        int                     (*ndo_bridge_setlink)(struct net_device *dev,
                                                      struct nlmsghdr *nlh,
                                                      u16 flags,
                                                      struct netlink_ext_ack *extack);
        int                     (*ndo_bridge_getlink)(struct sk_buff *skb,
                                                      u32 pid, u32 seq,
                                                      struct net_device *dev,
                                                      u32 filter_mask,
                                                      int nlflags);
        int                     (*ndo_bridge_dellink)(struct net_device *dev,
                                                      struct nlmsghdr *nlh,
                                                      u16 flags);
        int                     (*ndo_change_carrier)(struct net_device *dev,
                                                      bool new_carrier);
        int                     (*ndo_get_phys_port_id)(struct net_device *dev,
                                                        struct netdev_phys_item_id *ppid);
        int                     (*ndo_get_port_parent_id)(struct net_device *dev,
                                                          struct netdev_phys_item_id *ppid);
        int                     (*ndo_get_phys_port_name)(struct net_device *dev,
                                                          char *name, size_t len);
        void*                   (*ndo_dfwd_add_station)(struct net_device *pdev,
                                                        struct net_device *dev);
        void                    (*ndo_dfwd_del_station)(struct net_device *pdev,
                                                        void *priv);

        int                     (*ndo_set_tx_maxrate)(struct net_device *dev,
                                                      int queue_index,
                                                      u32 maxrate);
        int                     (*ndo_get_iflink)(const struct net_device *dev);
        int                     (*ndo_change_proto_down)(struct net_device *dev,
                                                         bool proto_down);
        int                     (*ndo_fill_metadata_dst)(struct net_device *dev,
                                                       struct sk_buff *skb);
        void                    (*ndo_set_rx_headroom)(struct net_device *dev,
                                                       int needed_headroom);
        int                     (*ndo_bpf)(struct net_device *dev,
                                           struct netdev_bpf *bpf);
        int                     (*ndo_xdp_xmit)(struct net_device *dev, int n,
                                                struct xdp_frame **xdp,
                                                u32 flags);
        struct net_device *     (*ndo_xdp_get_xmit_slave)(struct net_device *dev,
                                                          struct xdp_buff *xdp);
        int                     (*ndo_xsk_wakeup)(struct net_device *dev,
                                                  u32 queue_id, u32 flags);
        struct devlink_port *   (*ndo_get_devlink_port)(struct net_device *dev);
        int                     (*ndo_tunnel_ctl)(struct net_device *dev,
                                                  struct ip_tunnel_parm *p, int cmd);
        struct net_device *     (*ndo_get_peer_dev)(struct net_device *dev);
        int                     (*ndo_fill_forward_path)(struct net_device_path_ctx *ctx,
                                                         struct net_device_path *path);
};

/**
 * enum netdev_priv_flags - &struct net_device priv_flags
 *
 * These are the &struct net_device, they are only set internally
 * by drivers and used in the kernel. These flags are invisible to
 * userspace; this means that the order of these flags can change
 * during any kernel release.
 *
 * You should have a pretty good reason to be extending these flags.
 *
 * @IFF_802_1Q_VLAN: 802.1Q VLAN device
 * @IFF_EBRIDGE: Ethernet bridging device
 * @IFF_BONDING: bonding master or slave
 * @IFF_ISATAP: ISATAP interface (RFC4214)
 * @IFF_WAN_HDLC: WAN HDLC device
 * @IFF_XMIT_DST_RELEASE: dev_hard_start_xmit() is allowed to
 *      release skb->dst
 * @IFF_DONT_BRIDGE: disallow bridging this ether dev
 * @IFF_DISABLE_NETPOLL: disable netpoll at run-time
 * @IFF_MACVLAN_PORT: device used as macvlan port
 * @IFF_BRIDGE_PORT: device used as bridge port
 * @IFF_OVS_DATAPATH: device used as Open vSwitch datapath port
 * @IFF_TX_SKB_SHARING: The interface supports sharing skbs on transmit
 * @IFF_UNICAST_FLT: Supports unicast filtering
 * @IFF_TEAM_PORT: device used as team port
 * @IFF_SUPP_NOFCS: device supports sending custom FCS
 * @IFF_LIVE_ADDR_CHANGE: device supports hardware address
 *      change when it's running
 * @IFF_MACVLAN: Macvlan device
 * @IFF_XMIT_DST_RELEASE_PERM: IFF_XMIT_DST_RELEASE not taking into account
 *      underlying stacked devices
 * @IFF_L3MDEV_MASTER: device is an L3 master device
 * @IFF_NO_QUEUE: device can run without qdisc attached
 * @IFF_OPENVSWITCH: device is a Open vSwitch master
 * @IFF_L3MDEV_SLAVE: device is enslaved to an L3 master device
 * @IFF_TEAM: device is a team device
 * @IFF_RXFH_CONFIGURED: device has had Rx Flow indirection table configured
 * @IFF_PHONY_HEADROOM: the headroom value is controlled by an external
 *      entity (i.e. the master device for bridged veth)
 * @IFF_MACSEC: device is a MACsec device
 * @IFF_NO_RX_HANDLER: device doesn't support the rx_handler hook
 * @IFF_FAILOVER: device is a failover master device
 * @IFF_FAILOVER_SLAVE: device is lower dev of a failover master device
 * @IFF_L3MDEV_RX_HANDLER: only invoke the rx handler of L3 master device
 * @IFF_LIVE_RENAME_OK: rename is allowed while device is up and running
 * @IFF_TX_SKB_NO_LINEAR: device/driver is capable of xmitting frames with
 *      skb_headlen(skb) == 0 (data starts from frag0)
 */
enum netdev_priv_flags {
        IFF_802_1Q_VLAN                 = 1<<0,
        IFF_EBRIDGE                     = 1<<1,
        IFF_BONDING                     = 1<<2,
        IFF_ISATAP                      = 1<<3,
        IFF_WAN_HDLC                    = 1<<4,
        IFF_XMIT_DST_RELEASE            = 1<<5,
        IFF_DONT_BRIDGE                 = 1<<6,
        IFF_DISABLE_NETPOLL             = 1<<7,
        IFF_MACVLAN_PORT                = 1<<8,
        IFF_BRIDGE_PORT                 = 1<<9,
        IFF_OVS_DATAPATH                = 1<<10,
        IFF_TX_SKB_SHARING              = 1<<11,
        IFF_UNICAST_FLT                 = 1<<12,
        IFF_TEAM_PORT                   = 1<<13,
        IFF_SUPP_NOFCS                  = 1<<14,
        IFF_LIVE_ADDR_CHANGE            = 1<<15,
        IFF_MACVLAN                     = 1<<16,
        IFF_XMIT_DST_RELEASE_PERM       = 1<<17,
        IFF_L3MDEV_MASTER               = 1<<18,
        IFF_NO_QUEUE                    = 1<<19,
        IFF_OPENVSWITCH                 = 1<<20,
        IFF_L3MDEV_SLAVE                = 1<<21,
        IFF_TEAM                        = 1<<22,
        IFF_RXFH_CONFIGURED             = 1<<23,
        IFF_PHONY_HEADROOM              = 1<<24,
        IFF_MACSEC                      = 1<<25,
        IFF_NO_RX_HANDLER               = 1<<26,
        IFF_FAILOVER                    = 1<<27,
        IFF_FAILOVER_SLAVE              = 1<<28,
        IFF_L3MDEV_RX_HANDLER           = 1<<29,
        IFF_LIVE_RENAME_OK              = 1<<30,
        IFF_TX_SKB_NO_LINEAR            = 1<<31,
};

#define IFF_802_1Q_VLAN                 IFF_802_1Q_VLAN
#define IFF_EBRIDGE                     IFF_EBRIDGE
#define IFF_BONDING                     IFF_BONDING
#define IFF_ISATAP                      IFF_ISATAP
#define IFF_WAN_HDLC                    IFF_WAN_HDLC
#define IFF_XMIT_DST_RELEASE            IFF_XMIT_DST_RELEASE
#define IFF_DONT_BRIDGE                 IFF_DONT_BRIDGE
#define IFF_DISABLE_NETPOLL             IFF_DISABLE_NETPOLL
#define IFF_MACVLAN_PORT                IFF_MACVLAN_PORT
#define IFF_BRIDGE_PORT                 IFF_BRIDGE_PORT
#define IFF_OVS_DATAPATH                IFF_OVS_DATAPATH
#define IFF_TX_SKB_SHARING              IFF_TX_SKB_SHARING
#define IFF_UNICAST_FLT                 IFF_UNICAST_FLT
#define IFF_TEAM_PORT                   IFF_TEAM_PORT
#define IFF_SUPP_NOFCS                  IFF_SUPP_NOFCS
#define IFF_LIVE_ADDR_CHANGE            IFF_LIVE_ADDR_CHANGE
#define IFF_MACVLAN                     IFF_MACVLAN
#define IFF_XMIT_DST_RELEASE_PERM       IFF_XMIT_DST_RELEASE_PERM
#define IFF_L3MDEV_MASTER               IFF_L3MDEV_MASTER
#define IFF_NO_QUEUE                    IFF_NO_QUEUE
#define IFF_OPENVSWITCH                 IFF_OPENVSWITCH
#define IFF_L3MDEV_SLAVE                IFF_L3MDEV_SLAVE
#define IFF_TEAM                        IFF_TEAM
#define IFF_RXFH_CONFIGURED             IFF_RXFH_CONFIGURED
#define IFF_PHONY_HEADROOM              IFF_PHONY_HEADROOM
#define IFF_MACSEC                      IFF_MACSEC
#define IFF_NO_RX_HANDLER               IFF_NO_RX_HANDLER
#define IFF_FAILOVER                    IFF_FAILOVER
#define IFF_FAILOVER_SLAVE              IFF_FAILOVER_SLAVE
#define IFF_L3MDEV_RX_HANDLER           IFF_L3MDEV_RX_HANDLER
#define IFF_LIVE_RENAME_OK              IFF_LIVE_RENAME_OK
#define IFF_TX_SKB_NO_LINEAR            IFF_TX_SKB_NO_LINEAR

/* Specifies the type of the struct net_device::ml_priv pointer */
enum netdev_ml_priv_type {
        ML_PRIV_NONE,
        ML_PRIV_CAN,
};

/**
 *      struct net_device - The DEVICE structure.
 *
 *      Actually, this whole structure is a big mistake.  It mixes I/O
 *      data with strictly "high-level" data, and it has to know about
 *      almost every data structure used in the INET module.
 *
 *      @name:  This is the first field of the "visible" part of this structure
 *              (i.e. as seen by users in the "Space.c" file).  It is the name
 *              of the interface.
 *
 *      @name_node:     Name hashlist node
 *      @ifalias:       SNMP alias
 *      @mem_end:       Shared memory end
 *      @mem_start:     Shared memory start
 *      @base_addr:     Device I/O address
 *      @irq:           Device IRQ number
 *
 *      @state:         Generic network queuing layer state, see netdev_state_t
 *      @dev_list:      The global list of network devices
 *      @napi_list:     List entry used for polling NAPI devices
 *      @unreg_list:    List entry  when we are unregistering the
 *                      device; see the function unregister_netdev
 *      @close_list:    List entry used when we are closing the device
 *      @ptype_all:     Device-specific packet handlers for all protocols
 *      @ptype_specific: Device-specific, protocol-specific packet handlers
 *
 *      @adj_list:      Directly linked devices, like slaves for bonding
 *      @features:      Currently active device features
 *      @hw_features:   User-changeable features
 *
 *      @wanted_features:       User-requested features
 *      @vlan_features:         Mask of features inheritable by VLAN devices
 *
 *      @hw_enc_features:       Mask of features inherited by encapsulating devices
 *                              This field indicates what encapsulation
 *                              offloads the hardware is capable of doing,
 *                              and drivers will need to set them appropriately.
 *
 *      @mpls_features: Mask of features inheritable by MPLS
 *      @gso_partial_features: value(s) from NETIF_F_GSO\*
 *
 *      @ifindex:       interface index
 *      @group:         The group the device belongs to
 *
 *      @stats:         Statistics struct, which was left as a legacy, use
 *                      rtnl_link_stats64 instead
 *
 *      @rx_dropped:    Dropped packets by core network,
 *                      do not use this in drivers
 *      @tx_dropped:    Dropped packets by core network,
 *                      do not use this in drivers
 *      @rx_nohandler:  nohandler dropped packets by core network on
 *                      inactive devices, do not use this in drivers
 *      @carrier_up_count:      Number of times the carrier has been up
 *      @carrier_down_count:    Number of times the carrier has been down
 *
 *      @wireless_handlers:     List of functions to handle Wireless Extensions,
 *                              instead of ioctl,
 *                              see <net/iw_handler.h> for details.
 *      @wireless_data: Instance data managed by the core of wireless extensions
 *
 *      @netdev_ops:    Includes several pointers to callbacks,
 *                      if one wants to override the ndo_*() functions
 *      @ethtool_ops:   Management operations
 *      @l3mdev_ops:    Layer 3 master device operations
 *      @ndisc_ops:     Includes callbacks for different IPv6 neighbour
 *                      discovery handling. Necessary for e.g. 6LoWPAN.
 *      @xfrmdev_ops:   Transformation offload operations
 *      @tlsdev_ops:    Transport Layer Security offload operations
 *      @header_ops:    Includes callbacks for creating,parsing,caching,etc
 *                      of Layer 2 headers.
 *
 *      @flags:         Interface flags (a la BSD)
 *      @priv_flags:    Like 'flags' but invisible to userspace,
 *                      see if.h for the definitions
 *      @gflags:        Global flags ( kept as legacy )
 *      @padded:        How much padding added by alloc_netdev()
 *      @operstate:     RFC2863 operstate
 *      @link_mode:     Mapping policy to operstate
 *      @if_port:       Selectable AUI, TP, ...
 *      @dma:           DMA channel
 *      @mtu:           Interface MTU value
 *      @min_mtu:       Interface Minimum MTU value
 *      @max_mtu:       Interface Maximum MTU value
 *      @type:          Interface hardware type
 *      @hard_header_len: Maximum hardware header length.
 *      @min_header_len:  Minimum hardware header length
 *
 *      @needed_headroom: Extra headroom the hardware may need, but not in all
 *                        cases can this be guaranteed
 *      @needed_tailroom: Extra tailroom the hardware may need, but not in all
 *                        cases can this be guaranteed. Some cases also use
 *                        LL_MAX_HEADER instead to allocate the skb
 *
 *      interface address info:
 *
 *      @perm_addr:             Permanent hw address
 *      @addr_assign_type:      Hw address assignment type
 *      @addr_len:              Hardware address length
 *      @upper_level:           Maximum depth level of upper devices.
 *      @lower_level:           Maximum depth level of lower devices.
 *      @neigh_priv_len:        Used in neigh_alloc()
 *      @dev_id:                Used to differentiate devices that share
 *                              the same link layer address
 *      @dev_port:              Used to differentiate devices that share
 *                              the same function
 *      @addr_list_lock:        XXX: need comments on this one
 *      @name_assign_type:      network interface name assignment type
 *      @uc_promisc:            Counter that indicates promiscuous mode
 *                              has been enabled due to the need to listen to
 *                              additional unicast addresses in a device that
 *                              does not implement ndo_set_rx_mode()
 *      @uc:                    unicast mac addresses
 *      @mc:                    multicast mac addresses
 *      @dev_addrs:             list of device hw addresses
 *      @queues_kset:           Group of all Kobjects in the Tx and RX queues
 *      @promiscuity:           Number of times the NIC is told to work in
 *                              promiscuous mode; if it becomes 0 the NIC will
 *                              exit promiscuous mode
 *      @allmulti:              Counter, enables or disables allmulticast mode
 *
 *      @vlan_info:     VLAN info
 *      @dsa_ptr:       dsa specific data
 *      @tipc_ptr:      TIPC specific data
 *      @atalk_ptr:     AppleTalk link
 *      @ip_ptr:        IPv4 specific data
 *      @dn_ptr:        DECnet specific data
 *      @ip6_ptr:       IPv6 specific data
 *      @ax25_ptr:      AX.25 specific data
 *      @ieee80211_ptr: IEEE 802.11 specific data, assign before registering
 *      @ieee802154_ptr: IEEE 802.15.4 low-rate Wireless Personal Area Network
 *                       device struct
 *      @mpls_ptr:      mpls_dev struct pointer
 *      @mctp_ptr:      MCTP specific data
 *
 *      @dev_addr:      Hw address (before bcast,
 *                      because most packets are unicast)
 *
 *      @_rx:                   Array of RX queues
 *      @num_rx_queues:         Number of RX queues
 *                              allocated at register_netdev() time
 *      @real_num_rx_queues:    Number of RX queues currently active in device
 *      @xdp_prog:              XDP sockets filter program pointer
 *      @gro_flush_timeout:     timeout for GRO layer in NAPI
 *      @napi_defer_hard_irqs:  If not zero, provides a counter that would
 *                              allow to avoid NIC hard IRQ, on busy queues.
 *
 *      @rx_handler:            handler for received packets
 *      @rx_handler_data:       XXX: need comments on this one
 *      @miniq_ingress:         ingress/clsact qdisc specific data for
 *                              ingress processing
 *      @ingress_queue:         XXX: need comments on this one
 *      @nf_hooks_ingress:      netfilter hooks executed for ingress packets
 *      @broadcast:             hw bcast address
 *
 *      @rx_cpu_rmap:   CPU reverse-mapping for RX completion interrupts,
 *                      indexed by RX queue number. Assigned by driver.
 *                      This must only be set if the ndo_rx_flow_steer
 *                      operation is defined
 *      @index_hlist:           Device index hash chain
 *
 *      @_tx:                   Array of TX queues
 *      @num_tx_queues:         Number of TX queues allocated at alloc_netdev_mq() time
 *      @real_num_tx_queues:    Number of TX queues currently active in device
 *      @qdisc:                 Root qdisc from userspace point of view
 *      @tx_queue_len:          Max frames per queue allowed
 *      @tx_global_lock:        XXX: need comments on this one
 *      @xdp_bulkq:             XDP device bulk queue
 *      @xps_maps:              all CPUs/RXQs maps for XPS device
 *
 *      @xps_maps:      XXX: need comments on this one
 *      @miniq_egress:          clsact qdisc specific data for
 *                              egress processing
 *      @nf_hooks_egress:       netfilter hooks executed for egress packets
 *      @qdisc_hash:            qdisc hash table
 *      @watchdog_timeo:        Represents the timeout that is used by
 *                              the watchdog (see dev_watchdog())
 *      @watchdog_timer:        List of timers
 *
 *      @proto_down_reason:     reason a netdev interface is held down
 *      @pcpu_refcnt:           Number of references to this device
 *      @dev_refcnt:            Number of references to this device
 *      @todo_list:             Delayed register/unregister
 *      @link_watch_list:       XXX: need comments on this one
 *
 *      @reg_state:             Register/unregister state machine
 *      @dismantle:             Device is going to be freed
 *      @rtnl_link_state:       This enum represents the phases of creating
 *                              a new link
 *
 *      @needs_free_netdev:     Should unregister perform free_netdev?
 *      @priv_destructor:       Called from unregister
 *      @npinfo:                XXX: need comments on this one
 *      @nd_net:                Network namespace this network device is inside
 *
 *      @ml_priv:       Mid-layer private
 *      @ml_priv_type:  Mid-layer private type
 *      @lstats:        Loopback statistics
 *      @tstats:        Tunnel statistics
 *      @dstats:        Dummy statistics
 *      @vstats:        Virtual ethernet statistics
 *
 *      @garp_port:     GARP
 *      @mrp_port:      MRP
 *
 *      @dev:           Class/net/name entry
 *      @sysfs_groups:  Space for optional device, statistics and wireless
 *                      sysfs groups
 *
 *      @sysfs_rx_queue_group:  Space for optional per-rx queue attributes
 *      @rtnl_link_ops: Rtnl_link_ops
 *
 *      @gso_max_size:  Maximum size of generic segmentation offload
 *      @gso_max_segs:  Maximum number of segments that can be passed to the
 *                      NIC for GSO
 *
 *      @dcbnl_ops:     Data Center Bridging netlink ops
 *      @num_tc:        Number of traffic classes in the net device
 *      @tc_to_txq:     XXX: need comments on this one
 *      @prio_tc_map:   XXX: need comments on this one
 *
 *      @fcoe_ddp_xid:  Max exchange id for FCoE LRO by ddp
 *
 *      @priomap:       XXX: need comments on this one
 *      @phydev:        Physical device may attach itself
 *                      for hardware timestamping
 *      @sfp_bus:       attached &struct sfp_bus structure.
 *
 *      @qdisc_tx_busylock: lockdep class annotating Qdisc->busylock spinlock
 *
 *      @proto_down:    protocol port state information can be sent to the
 *                      switch driver and used to set the phys state of the
 *                      switch port.
 *
 *      @wol_enabled:   Wake-on-LAN is enabled
 *
 *      @threaded:      napi threaded mode is enabled
 *
 *      @net_notifier_list:     List of per-net netdev notifier block
 *                              that follow this device when it is moved
 *                              to another network namespace.
 *
 *      @macsec_ops:    MACsec offloading ops
 *
 *      @udp_tunnel_nic_info:   static structure describing the UDP tunnel
 *                              offload capabilities of the device
 *      @udp_tunnel_nic:        UDP tunnel offload state
 *      @xdp_state:             stores info on attached XDP BPF programs
 *
 *      @nested_level:  Used as a parameter of spin_lock_nested() of
 *                      dev->addr_list_lock.
 *      @unlink_list:   As netif_addr_lock() can be called recursively,
 *                      keep a list of interfaces to be deleted.
 *
 *      FIXME: cleanup struct net_device such that network protocol info
 *      moves out.
 */

struct net_device {
        char                    name[IFNAMSIZ];
        struct netdev_name_node *name_node;
        struct dev_ifalias      __rcu *ifalias;
        /*
         *      I/O specific fields
         *      FIXME: Merge these and struct ifmap into one
         */
        unsigned long           mem_end;
        unsigned long           mem_start;
        unsigned long           base_addr;

        /*
         *      Some hardware also needs these fields (state,dev_list,
         *      napi_list,unreg_list,close_list) but they are not
         *      part of the usual set specified in Space.c.
         */

        unsigned long           state;

        struct list_head        dev_list;
        struct list_head        napi_list;
        struct list_head        unreg_list;
        struct list_head        close_list;
        struct list_head        ptype_all;
        struct list_head        ptype_specific;

        struct {
                struct list_head upper;
                struct list_head lower;
        } adj_list;

        /* Read-mostly cache-line for fast-path access */
        unsigned int            flags;
        unsigned int            priv_flags;
        const struct net_device_ops *netdev_ops;
        int                     ifindex;
        unsigned short          gflags;
        unsigned short          hard_header_len;

        /* Note : dev->mtu is often read without holding a lock.
         * Writers usually hold RTNL.
         * It is recommended to use READ_ONCE() to annotate the reads,
         * and to use WRITE_ONCE() to annotate the writes.
         */
        unsigned int            mtu;
        unsigned short          needed_headroom;
        unsigned short          needed_tailroom;

        netdev_features_t       features;
        netdev_features_t       hw_features;
        netdev_features_t       wanted_features;

        netdev_features_t       vlan_features;
        netdev_features_t       hw_enc_features;
        netdev_features_t       mpls_features;
        netdev_features_t       gso_partial_features;

        unsigned int            min_mtu;
        unsigned int            max_mtu;
        unsigned short          type;
        unsigned char           min_header_len;
        unsigned char           name_assign_type;

        int                     group;

        struct net_device_stats stats; /* not used by modern drivers */

        atomic_long_t           rx_dropped;
        atomic_long_t           tx_dropped;
        atomic_long_t           rx_nohandler;

        /* Stats to monitor link on/off, flapping */
        atomic_t                carrier_up_count;
        atomic_t                carrier_down_count;

#ifdef CONFIG_WIRELESS_EXT
        const struct iw_handler_def *wireless_handlers;
        struct iw_public_data   *wireless_data;
#endif
        const struct ethtool_ops *ethtool_ops;
#ifdef CONFIG_NET_L3_MASTER_DEV
        const struct l3mdev_ops *l3mdev_ops;
#endif
#if IS_ENABLED(CONFIG_IPV6)
        const struct ndisc_ops *ndisc_ops;
#endif

#ifdef CONFIG_XFRM_OFFLOAD
        const struct xfrmdev_ops *xfrmdev_ops;
#endif

#if IS_ENABLED(CONFIG_TLS_DEVICE)
        const struct tlsdev_ops *tlsdev_ops;
#endif

        const struct header_ops *header_ops;

        unsigned char           operstate;
        unsigned char           link_mode;

        unsigned char           if_port;
        unsigned char           dma;

        /* Interface address info. */
        unsigned char           perm_addr[MAX_ADDR_LEN];
        unsigned char           addr_assign_type;
        unsigned char           addr_len;
        unsigned char           upper_level;
        unsigned char           lower_level;

        unsigned short          neigh_priv_len;
        unsigned short          dev_id;
        unsigned short          dev_port;
        unsigned short          padded;

        spinlock_t              addr_list_lock;
        int                     irq;

        struct netdev_hw_addr_list      uc;
        struct netdev_hw_addr_list      mc;
        struct netdev_hw_addr_list      dev_addrs;

#ifdef CONFIG_SYSFS
        struct kset             *queues_kset;
#endif
#ifdef CONFIG_LOCKDEP
        struct list_head        unlink_list;
#endif
        unsigned int            promiscuity;
        unsigned int            allmulti;
        bool                    uc_promisc;
#ifdef CONFIG_LOCKDEP
        unsigned char           nested_level;
#endif


        /* Protocol-specific pointers */

#if IS_ENABLED(CONFIG_VLAN_8021Q)
        struct vlan_info __rcu  *vlan_info;
#endif
#if IS_ENABLED(CONFIG_NET_DSA)
        struct dsa_port         *dsa_ptr;
#endif
#if IS_ENABLED(CONFIG_TIPC)
        struct tipc_bearer __rcu *tipc_ptr;
#endif
#if IS_ENABLED(CONFIG_IRDA) || IS_ENABLED(CONFIG_ATALK)
        void                    *atalk_ptr;
#endif
        struct in_device __rcu  *ip_ptr;
#if IS_ENABLED(CONFIG_DECNET)
        struct dn_dev __rcu     *dn_ptr;
#endif
        struct inet6_dev __rcu  *ip6_ptr;
#if IS_ENABLED(CONFIG_AX25)
        void                    *ax25_ptr;
#endif
        struct wireless_dev     *ieee80211_ptr;
        struct wpan_dev         *ieee802154_ptr;
#if IS_ENABLED(CONFIG_MPLS_ROUTING)
        struct mpls_dev __rcu   *mpls_ptr;
#endif
#if IS_ENABLED(CONFIG_MCTP)
        struct mctp_dev __rcu   *mctp_ptr;
#endif

/*
 * Cache lines mostly used on receive path (including eth_type_trans())
 */
        /* Interface address info used in eth_type_trans() */
        unsigned char           *dev_addr;

        struct netdev_rx_queue  *_rx;
        unsigned int            num_rx_queues;
        unsigned int            real_num_rx_queues;

        struct bpf_prog __rcu   *xdp_prog;
        unsigned long           gro_flush_timeout;
        int                     napi_defer_hard_irqs;
        rx_handler_func_t __rcu *rx_handler;
        void __rcu              *rx_handler_data;

#ifdef CONFIG_NET_CLS_ACT
        struct mini_Qdisc __rcu *miniq_ingress;
#endif
        struct netdev_queue __rcu *ingress_queue;
#ifdef CONFIG_NETFILTER_INGRESS
        struct nf_hook_entries __rcu *nf_hooks_ingress;
#endif

        unsigned char           broadcast[MAX_ADDR_LEN];
#ifdef CONFIG_RFS_ACCEL
        struct cpu_rmap         *rx_cpu_rmap;
#endif
        struct hlist_node       index_hlist;

/*
 * Cache lines mostly used on transmit path
 */
        struct netdev_queue     *_tx ____cacheline_aligned_in_smp;
        unsigned int            num_tx_queues;
        unsigned int            real_num_tx_queues;
        struct Qdisc            *qdisc;
        unsigned int            tx_queue_len;
        spinlock_t              tx_global_lock;

        struct xdp_dev_bulk_queue __percpu *xdp_bulkq;

#ifdef CONFIG_XPS
        struct xps_dev_maps __rcu *xps_maps[XPS_MAPS_MAX];
#endif
#ifdef CONFIG_NET_CLS_ACT
        struct mini_Qdisc __rcu *miniq_egress;
#endif
#ifdef CONFIG_NETFILTER_EGRESS
        struct nf_hook_entries __rcu *nf_hooks_egress;
#endif

#ifdef CONFIG_NET_SCHED
        DECLARE_HASHTABLE       (qdisc_hash, 4);
#endif
        /* These may be needed for future network-power-down code. */
        struct timer_list       watchdog_timer;
        int                     watchdog_timeo;

        u32                     proto_down_reason;

        struct list_head        todo_list;

#ifdef CONFIG_PCPU_DEV_REFCNT
        int __percpu            *pcpu_refcnt;
#else
        refcount_t              dev_refcnt;
#endif

        struct list_head        link_watch_list;

        enum { NETREG_UNINITIALIZED=0,
               NETREG_REGISTERED,       /* completed register_netdevice */
               NETREG_UNREGISTERING,    /* called unregister_netdevice */
               NETREG_UNREGISTERED,     /* completed unregister todo */
               NETREG_RELEASED,         /* called free_netdev */
               NETREG_DUMMY,            /* dummy device for NAPI poll */
        } reg_state:8;

        bool dismantle;

        enum {
                RTNL_LINK_INITIALIZED,
                RTNL_LINK_INITIALIZING,
        } rtnl_link_state:16;

        bool needs_free_netdev;
        void (*priv_destructor)(struct net_device *dev);

#ifdef CONFIG_NETPOLL
        struct netpoll_info __rcu       *npinfo;
#endif

        possible_net_t                  nd_net;

        /* mid-layer private */
        void                            *ml_priv;
        enum netdev_ml_priv_type        ml_priv_type;

        union {
                struct pcpu_lstats __percpu             *lstats;
                struct pcpu_sw_netstats __percpu        *tstats;
                struct pcpu_dstats __percpu             *dstats;
        };

#if IS_ENABLED(CONFIG_GARP)
        struct garp_port __rcu  *garp_port;
#endif
#if IS_ENABLED(CONFIG_MRP)
        struct mrp_port __rcu   *mrp_port;
#endif

        struct device           dev;
        const struct attribute_group *sysfs_groups[4];
        const struct attribute_group *sysfs_rx_queue_group;

        const struct rtnl_link_ops *rtnl_link_ops;

        /* for setting kernel sock attribute on TCP connection setup */
#define GSO_MAX_SIZE            65536
        unsigned int            gso_max_size;
#define GSO_MAX_SEGS            65535
        u16                     gso_max_segs;

#ifdef CONFIG_DCB
        const struct dcbnl_rtnl_ops *dcbnl_ops;
#endif
        s16                     num_tc;
        struct netdev_tc_txq    tc_to_txq[TC_MAX_QUEUE];
        u8                      prio_tc_map[TC_BITMASK + 1];

#if IS_ENABLED(CONFIG_FCOE)
        unsigned int            fcoe_ddp_xid;
#endif
#if IS_ENABLED(CONFIG_CGROUP_NET_PRIO)
        struct netprio_map __rcu *priomap;
#endif
        struct phy_device       *phydev;
        struct sfp_bus          *sfp_bus;
        struct lock_class_key   *qdisc_tx_busylock;
        bool                    proto_down;
        unsigned                wol_enabled:1;
        unsigned                threaded:1;

        struct list_head        net_notifier_list;

#if IS_ENABLED(CONFIG_MACSEC)
        /* MACsec management functions */
        const struct macsec_ops *macsec_ops;
#endif
        const struct udp_tunnel_nic_info        *udp_tunnel_nic_info;
        struct udp_tunnel_nic   *udp_tunnel_nic;

        /* protected by rtnl_lock */
        struct bpf_xdp_entity   xdp_state[__MAX_XDP_MODE];
};
#define to_net_dev(d) container_of(d, struct net_device, dev)

static inline bool netif_elide_gro(const struct net_device *dev)
{
        if (!(dev->features & NETIF_F_GRO) || dev->xdp_prog)
                return true;
        return false;
}

#define NETDEV_ALIGN            32

static inline
int netdev_get_prio_tc_map(const struct net_device *dev, u32 prio)
{
        return dev->prio_tc_map[prio & TC_BITMASK];
}

static inline
int netdev_set_prio_tc_map(struct net_device *dev, u8 prio, u8 tc)
{
        if (tc >= dev->num_tc)
                return -EINVAL;

        dev->prio_tc_map[prio & TC_BITMASK] = tc & TC_BITMASK;
        return 0;
}

int netdev_txq_to_tc(struct net_device *dev, unsigned int txq);
void netdev_reset_tc(struct net_device *dev);
int netdev_set_tc_queue(struct net_device *dev, u8 tc, u16 count, u16 offset);
int netdev_set_num_tc(struct net_device *dev, u8 num_tc);

static inline
int netdev_get_num_tc(struct net_device *dev)
{
        return dev->num_tc;
}

static inline void net_prefetch(void *p)
{
        prefetch(p);
#if L1_CACHE_BYTES < 128
        prefetch((u8 *)p + L1_CACHE_BYTES);
#endif
}

static inline void net_prefetchw(void *p)
{
        prefetchw(p);
#if L1_CACHE_BYTES < 128
        prefetchw((u8 *)p + L1_CACHE_BYTES);
#endif
}

void netdev_unbind_sb_channel(struct net_device *dev,
                              struct net_device *sb_dev);
int netdev_bind_sb_channel_queue(struct net_device *dev,
                                 struct net_device *sb_dev,
                                 u8 tc, u16 count, u16 offset);
int netdev_set_sb_channel(struct net_device *dev, u16 channel);
static inline int netdev_get_sb_channel(struct net_device *dev)
{
        return max_t(int, -dev->num_tc, 0);
}

static inline
struct netdev_queue *netdev_get_tx_queue(const struct net_device *dev,
                                         unsigned int index)
{
        return &dev->_tx[index];
}

static inline struct netdev_queue *skb_get_tx_queue(const struct net_device *dev,
                                                    const struct sk_buff *skb)
{
        return netdev_get_tx_queue(dev, skb_get_queue_mapping(skb));
}

static inline void netdev_for_each_tx_queue(struct net_device *dev,
                                            void (*f)(struct net_device *,
                                                      struct netdev_queue *,
                                                      void *),
                                            void *arg)
{
        unsigned int i;

        for (i = 0; i < dev->num_tx_queues; i++)
                f(dev, &dev->_tx[i], arg);
}

#define netdev_lockdep_set_classes(dev)                         \
{                                                               \
        static struct lock_class_key qdisc_tx_busylock_key;     \
        static struct lock_class_key qdisc_xmit_lock_key;       \
        static struct lock_class_key dev_addr_list_lock_key;    \
        unsigned int i;                                         \
                                                                \
        (dev)->qdisc_tx_busylock = &qdisc_tx_busylock_key;      \
        lockdep_set_class(&(dev)->addr_list_lock,               \
                          &dev_addr_list_lock_key);             \
        for (i = 0; i < (dev)->num_tx_queues; i++)              \
                lockdep_set_class(&(dev)->_tx[i]._xmit_lock,    \
                                  &qdisc_xmit_lock_key);        \
}

u16 netdev_pick_tx(struct net_device *dev, struct sk_buff *skb,
                     struct net_device *sb_dev);
struct netdev_queue *netdev_core_pick_tx(struct net_device *dev,
                                         struct sk_buff *skb,
                                         struct net_device *sb_dev);

/* returns the headroom that the master device needs to take in account
 * when forwarding to this dev
 */
static inline unsigned netdev_get_fwd_headroom(struct net_device *dev)
{
        return dev->priv_flags & IFF_PHONY_HEADROOM ? 0 : dev->needed_headroom;
}

static inline void netdev_set_rx_headroom(struct net_device *dev, int new_hr)
{
        if (dev->netdev_ops->ndo_set_rx_headroom)
                dev->netdev_ops->ndo_set_rx_headroom(dev, new_hr);
}

/* set the device rx headroom to the dev's default */
static inline void netdev_reset_rx_headroom(struct net_device *dev)
{
        netdev_set_rx_headroom(dev, -1);
}

static inline void *netdev_get_ml_priv(struct net_device *dev,
                                       enum netdev_ml_priv_type type)
{
        if (dev->ml_priv_type != type)
                return NULL;

        return dev->ml_priv;
}

static inline void netdev_set_ml_priv(struct net_device *dev,
                                      void *ml_priv,
                                      enum netdev_ml_priv_type type)
{
        WARN(dev->ml_priv_type && dev->ml_priv_type != type,
             "Overwriting already set ml_priv_type (%u) with different ml_priv_type (%u)!\n",
             dev->ml_priv_type, type);
        WARN(!dev->ml_priv_type && dev->ml_priv,
             "Overwriting already set ml_priv and ml_priv_type is ML_PRIV_NONE!\n");

        dev->ml_priv = ml_priv;
        dev->ml_priv_type = type;
}

/*
 * Net namespace inlines
 */
static inline
struct net *dev_net(const struct net_device *dev)
{
        return read_pnet(&dev->nd_net);
}

static inline
void dev_net_set(struct net_device *dev, struct net *net)
{
        write_pnet(&dev->nd_net, net);
}

/**
 *      netdev_priv - access network device private data
 *      @dev: network device
 *
 * Get network device private data
 */
static inline void *netdev_priv(const struct net_device *dev)
{
        return (char *)dev + ALIGN(sizeof(struct net_device), NETDEV_ALIGN);
}

/* Set the sysfs physical device reference for the network logical device
 * if set prior to registration will cause a symlink during initialization.
 */
#define SET_NETDEV_DEV(net, pdev)       ((net)->dev.parent = (pdev))

/* Set the sysfs device type for the network logical device to allow
 * fine-grained identification of different network device types. For
 * example Ethernet, Wireless LAN, Bluetooth, WiMAX etc.
 */
#define SET_NETDEV_DEVTYPE(net, devtype)        ((net)->dev.type = (devtype))

/* Default NAPI poll() weight
 * Device drivers are strongly advised to not use bigger value
 */
#define NAPI_POLL_WEIGHT 64

/**
 *      netif_napi_add - initialize a NAPI context
 *      @dev:  network device
 *      @napi: NAPI context
 *      @poll: polling function
 *      @weight: default weight
 *
 * netif_napi_add() must be used to initialize a NAPI context prior to calling
 * *any* of the other NAPI-related functions.
 */
void netif_napi_add(struct net_device *dev, struct napi_struct *napi,
                    int (*poll)(struct napi_struct *, int), int weight);

/**
 *      netif_tx_napi_add - initialize a NAPI context
 *      @dev:  network device
 *      @napi: NAPI context
 *      @poll: polling function
 *      @weight: default weight
 *
 * This variant of netif_napi_add() should be used from drivers using NAPI
 * to exclusively poll a TX queue.
 * This will avoid we add it into napi_hash[], thus polluting this hash table.
 */
static inline void netif_tx_napi_add(struct net_device *dev,
                                     struct napi_struct *napi,
                                     int (*poll)(struct napi_struct *, int),
                                     int weight)
{
        set_bit(NAPI_STATE_NO_BUSY_POLL, &napi->state);
        netif_napi_add(dev, napi, poll, weight);
}

/**
 *  __netif_napi_del - remove a NAPI context
 *  @napi: NAPI context
 *
 * Warning: caller must observe RCU grace period before freeing memory
 * containing @napi. Drivers might want to call this helper to combine
 * all the needed RCU grace periods into a single one.
 */
void __netif_napi_del(struct napi_struct *napi);

/**
 *  netif_napi_del - remove a NAPI context
 *  @napi: NAPI context
 *
 *  netif_napi_del() removes a NAPI context from the network device NAPI list
 */
static inline void netif_napi_del(struct napi_struct *napi)
{
        __netif_napi_del(napi);
        synchronize_net();
}

struct napi_gro_cb {
        /* Virtual address of skb_shinfo(skb)->frags[0].page + offset. */
        void    *frag0;

        /* Length of frag0. */
        unsigned int frag0_len;

        /* This indicates where we are processing relative to skb->data. */
        int     data_offset;

        /* This is non-zero if the packet cannot be merged with the new skb. */
        u16     flush;

        /* Save the IP ID here and check when we get to the transport layer */
        u16     flush_id;

        /* Number of segments aggregated. */
        u16     count;

        /* Start offset for remote checksum offload */
        u16     gro_remcsum_start;

        /* jiffies when first packet was created/queued */
        unsigned long age;

        /* Used in ipv6_gro_receive() and foo-over-udp */
        u16     proto;

        /* This is non-zero if the packet may be of the same flow. */
        u8      same_flow:1;

        /* Used in tunnel GRO receive */
        u8      encap_mark:1;

        /* GRO checksum is valid */
        u8      csum_valid:1;

        /* Number of checksums via CHECKSUM_UNNECESSARY */
        u8      csum_cnt:3;

        /* Free the skb? */
        u8      free:2;
#define NAPI_GRO_FREE             1
#define NAPI_GRO_FREE_STOLEN_HEAD 2

        /* Used in foo-over-udp, set in udp[46]_gro_receive */
        u8      is_ipv6:1;

        /* Used in GRE, set in fou/gue_gro_receive */
        u8      is_fou:1;

        /* Used to determine if flush_id can be ignored */
        u8      is_atomic:1;

        /* Number of gro_receive callbacks this packet already went through */
        u8 recursion_counter:4;

        /* GRO is done by frag_list pointer chaining. */
        u8      is_flist:1;

        /* used to support CHECKSUM_COMPLETE for tunneling protocols */
        __wsum  csum;

        /* used in skb_gro_receive() slow path */
        struct sk_buff *last;
};

#define NAPI_GRO_CB(skb) ((struct napi_gro_cb *)(skb)->cb)

#define GRO_RECURSION_LIMIT 15
static inline int gro_recursion_inc_test(struct sk_buff *skb)
{
        return ++NAPI_GRO_CB(skb)->recursion_counter == GRO_RECURSION_LIMIT;
}

typedef struct sk_buff *(*gro_receive_t)(struct list_head *, struct sk_buff *);
static inline struct sk_buff *call_gro_receive(gro_receive_t cb,
                                               struct list_head *head,
                                               struct sk_buff *skb)
{
        if (unlikely(gro_recursion_inc_test(skb))) {
                NAPI_GRO_CB(skb)->flush |= 1;
                return NULL;
        }

        return cb(head, skb);
}

typedef struct sk_buff *(*gro_receive_sk_t)(struct sock *, struct list_head *,
                                            struct sk_buff *);
static inline struct sk_buff *call_gro_receive_sk(gro_receive_sk_t cb,
                                                  struct sock *sk,
                                                  struct list_head *head,
                                                  struct sk_buff *skb)
{
        if (unlikely(gro_recursion_inc_test(skb))) {
                NAPI_GRO_CB(skb)->flush |= 1;
                return NULL;
        }

        return cb(sk, head, skb);
}

struct packet_type {
        __be16                  type;   /* This is really htons(ether_type). */
        bool                    ignore_outgoing;
        struct net_device       *dev;   /* NULL is wildcarded here           */
        int                     (*func) (struct sk_buff *,
                                         struct net_device *,
                                         struct packet_type *,
                                         struct net_device *);
        void                    (*list_func) (struct list_head *,
                                              struct packet_type *,
                                              struct net_device *);
        bool                    (*id_match)(struct packet_type *ptype,
                                            struct sock *sk);
        void                    *af_packet_priv;
        struct list_head        list;
};

struct offload_callbacks {
        struct sk_buff          *(*gso_segment)(struct sk_buff *skb,
                                                netdev_features_t features);
        struct sk_buff          *(*gro_receive)(struct list_head *head,
                                                struct sk_buff *skb);
        int                     (*gro_complete)(struct sk_buff *skb, int nhoff);
};

struct packet_offload {
        __be16                   type;  /* This is really htons(ether_type). */
        u16                      priority;
        struct offload_callbacks callbacks;
        struct list_head         list;
};

/* often modified stats are per-CPU, other are shared (netdev->stats) */
struct pcpu_sw_netstats {
        u64     rx_packets;
        u64     rx_bytes;
        u64     tx_packets;
        u64     tx_bytes;
        struct u64_stats_sync   syncp;
} __aligned(4 * sizeof(u64));

struct pcpu_lstats {
        u64_stats_t packets;
        u64_stats_t bytes;
        struct u64_stats_sync syncp;
} __aligned(2 * sizeof(u64));

void dev_lstats_read(struct net_device *dev, u64 *packets, u64 *bytes);

static inline void dev_sw_netstats_rx_add(struct net_device *dev, unsigned int len)
{
        struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

        u64_stats_update_begin(&tstats->syncp);
        tstats->rx_bytes += len;
        tstats->rx_packets++;
        u64_stats_update_end(&tstats->syncp);
}

static inline void dev_sw_netstats_tx_add(struct net_device *dev,
                                          unsigned int packets,
                                          unsigned int len)
{
        struct pcpu_sw_netstats *tstats = this_cpu_ptr(dev->tstats);

        u64_stats_update_begin(&tstats->syncp);
        tstats->tx_bytes += len;
        tstats->tx_packets += packets;
        u64_stats_update_end(&tstats->syncp);
}

static inline void dev_lstats_add(struct net_device *dev, unsigned int len)
{
        struct pcpu_lstats *lstats = this_cpu_ptr(dev->lstats);

        u64_stats_update_begin(&lstats->syncp);
        u64_stats_add(&lstats->bytes, len);
        u64_stats_inc(&lstats->packets);
        u64_stats_update_end(&lstats->syncp);
}

#define __netdev_alloc_pcpu_stats(type, gfp)                            \
({                                                                      \
        typeof(type) __percpu *pcpu_stats = alloc_percpu_gfp(type, gfp);\
        if (pcpu_stats) {                                               \
                int __cpu;                                              \
                for_each_possible_cpu(__cpu) {                          \
                        typeof(type) *stat;                             \
                        stat = per_cpu_ptr(pcpu_stats, __cpu);          \
                        u64_stats_init(&stat->syncp);                   \
                }                                                       \
        }                                                               \
        pcpu_stats;                                                     \
})

#define netdev_alloc_pcpu_stats(type)                                   \
        __netdev_alloc_pcpu_stats(type, GFP_KERNEL)

#define devm_netdev_alloc_pcpu_stats(dev, type)                         \
({                                                                      \
        typeof(type) __percpu *pcpu_stats = devm_alloc_percpu(dev, type);\
        if (pcpu_stats) {                                               \
                int __cpu;                                              \
                for_each_possible_cpu(__cpu) {                          \
                        typeof(type) *stat;                             \
                        stat = per_cpu_ptr(pcpu_stats, __cpu);          \
                        u64_stats_init(&stat->syncp);                   \
                }                                                       \
        }                                                               \
        pcpu_stats;                                                     \
})

enum netdev_lag_tx_type {
        NETDEV_LAG_TX_TYPE_UNKNOWN,
        NETDEV_LAG_TX_TYPE_RANDOM,
        NETDEV_LAG_TX_TYPE_BROADCAST,
        NETDEV_LAG_TX_TYPE_ROUNDROBIN,
        NETDEV_LAG_TX_TYPE_ACTIVEBACKUP,
        NETDEV_LAG_TX_TYPE_HASH,
};

enum netdev_lag_hash {
        NETDEV_LAG_HASH_NONE,
        NETDEV_LAG_HASH_L2,
        NETDEV_LAG_HASH_L34,
        NETDEV_LAG_HASH_L23,
        NETDEV_LAG_HASH_E23,
        NETDEV_LAG_HASH_E34,
        NETDEV_LAG_HASH_VLAN_SRCMAC,
        NETDEV_LAG_HASH_UNKNOWN,
};

struct netdev_lag_upper_info {
        enum netdev_lag_tx_type tx_type;
        enum netdev_lag_hash hash_type;
};

struct netdev_lag_lower_state_info {
        u8 link_up : 1,
           tx_enabled : 1;
};

#include <linux/notifier.h>

/* netdevice notifier chain. Please remember to update netdev_cmd_to_name()
 * and the rtnetlink notification exclusion list in rtnetlink_event() when
 * adding new types.
 */
enum netdev_cmd {
        NETDEV_UP       = 1,    /* For now you can't veto a device up/down */
        NETDEV_DOWN,
        NETDEV_REBOOT,          /* Tell a protocol stack a network interface
                                   detected a hardware crash and restarted
                                   - we can use this eg to kick tcp sessions
                                   once done */
        NETDEV_CHANGE,          /* Notify device state change */
        NETDEV_REGISTER,
        NETDEV_UNREGISTER,
        NETDEV_CHANGEMTU,       /* notify after mtu change happened */
        NETDEV_CHANGEADDR,      /* notify after the address change */
        NETDEV_PRE_CHANGEADDR,  /* notify before the address change */
        NETDEV_GOING_DOWN,
        NETDEV_CHANGENAME,
        NETDEV_FEAT_CHANGE,
        NETDEV_BONDING_FAILOVER,
        NETDEV_PRE_UP,
        NETDEV_PRE_TYPE_CHANGE,
        NETDEV_POST_TYPE_CHANGE,
        NETDEV_POST_INIT,
        NETDEV_RELEASE,
        NETDEV_NOTIFY_PEERS,
        NETDEV_JOIN,
        NETDEV_CHANGEUPPER,
        NETDEV_RESEND_IGMP,
        NETDEV_PRECHANGEMTU,    /* notify before mtu change happened */
        NETDEV_CHANGEINFODATA,
        NETDEV_BONDING_INFO,
        NETDEV_PRECHANGEUPPER,
        NETDEV_CHANGELOWERSTATE,
        NETDEV_UDP_TUNNEL_PUSH_INFO,
        NETDEV_UDP_TUNNEL_DROP_INFO,
        NETDEV_CHANGE_TX_QUEUE_LEN,
        NETDEV_CVLAN_FILTER_PUSH_INFO,
        NETDEV_CVLAN_FILTER_DROP_INFO,
        NETDEV_SVLAN_FILTER_PUSH_INFO,
        NETDEV_SVLAN_FILTER_DROP_INFO,
};
const char *netdev_cmd_to_name(enum netdev_cmd cmd);

int register_netdevice_notifier(struct notifier_block *nb);
int unregister_netdevice_notifier(struct notifier_block *nb);
int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb);
int unregister_netdevice_notifier_net(struct net *net,
                                      struct notifier_block *nb);
int register_netdevice_notifier_dev_net(struct net_device *dev,
                                        struct notifier_block *nb,
                                        struct netdev_net_notifier *nn);
int unregister_netdevice_notifier_dev_net(struct net_device *dev,
                                          struct notifier_block *nb,
                                          struct netdev_net_notifier *nn);

struct netdev_notifier_info {
        struct net_device       *dev;
        struct netlink_ext_ack  *extack;
};

struct netdev_notifier_info_ext {
        struct netdev_notifier_info info; /* must be first */
        union {
                u32 mtu;
        } ext;
};

struct netdev_notifier_change_info {
        struct netdev_notifier_info info; /* must be first */
        unsigned int flags_changed;
};

struct netdev_notifier_changeupper_info {
        struct netdev_notifier_info info; /* must be first */
        struct net_device *upper_dev; /* new upper dev */
        bool master; /* is upper dev master */
        bool linking; /* is the notification for link or unlink */
        void *upper_info; /* upper dev info */
};

struct netdev_notifier_changelowerstate_info {
        struct netdev_notifier_info info; /* must be first */
        void *lower_state_info; /* is lower dev state */
};

struct netdev_notifier_pre_changeaddr_info {
        struct netdev_notifier_info info; /* must be first */
        const unsigned char *dev_addr;
};

static inline void netdev_notifier_info_init(struct netdev_notifier_info *info,
                                             struct net_device *dev)
{
        info->dev = dev;
        info->extack = NULL;
}

static inline struct net_device *
netdev_notifier_info_to_dev(const struct netdev_notifier_info *info)
{
        return info->dev;
}

static inline struct netlink_ext_ack *
netdev_notifier_info_to_extack(const struct netdev_notifier_info *info)
{
        return info->extack;
}

int call_netdevice_notifiers(unsigned long val, struct net_device *dev);


extern rwlock_t                         dev_base_lock;          /* Device list lock */

#define for_each_netdev(net, d)         \
                list_for_each_entry(d, &(net)->dev_base_head, dev_list)
#define for_each_netdev_reverse(net, d) \
                list_for_each_entry_reverse(d, &(net)->dev_base_head, dev_list)
#define for_each_netdev_rcu(net, d)             \
                list_for_each_entry_rcu(d, &(net)->dev_base_head, dev_list)
#define for_each_netdev_safe(net, d, n) \
                list_for_each_entry_safe(d, n, &(net)->dev_base_head, dev_list)
#define for_each_netdev_continue(net, d)                \
                list_for_each_entry_continue(d, &(net)->dev_base_head, dev_list)
#define for_each_netdev_continue_reverse(net, d)                \
                list_for_each_entry_continue_reverse(d, &(net)->dev_base_head, \
                                                     dev_list)
#define for_each_netdev_continue_rcu(net, d)            \
        list_for_each_entry_continue_rcu(d, &(net)->dev_base_head, dev_list)
#define for_each_netdev_in_bond_rcu(bond, slave)        \
                for_each_netdev_rcu(&init_net, slave)   \
                        if (netdev_master_upper_dev_get_rcu(slave) == (bond))
#define net_device_entry(lh)    list_entry(lh, struct net_device, dev_list)

static inline struct net_device *next_net_device(struct net_device *dev)
{
        struct list_head *lh;
        struct net *net;

        net = dev_net(dev);
        lh = dev->dev_list.next;
        return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
}

static inline struct net_device *next_net_device_rcu(struct net_device *dev)
{
        struct list_head *lh;
        struct net *net;

        net = dev_net(dev);
        lh = rcu_dereference(list_next_rcu(&dev->dev_list));
        return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
}

static inline struct net_device *first_net_device(struct net *net)
{
        return list_empty(&net->dev_base_head) ? NULL :
                net_device_entry(net->dev_base_head.next);
}

static inline struct net_device *first_net_device_rcu(struct net *net)
{
        struct list_head *lh = rcu_dereference(list_next_rcu(&net->dev_base_head));

        return lh == &net->dev_base_head ? NULL : net_device_entry(lh);
}

int netdev_boot_setup_check(struct net_device *dev);
struct net_device *dev_getbyhwaddr_rcu(struct net *net, unsigned short type,
                                       const char *hwaddr);
struct net_device *dev_getfirstbyhwtype(struct net *net, unsigned short type);
void dev_add_pack(struct packet_type *pt);
void dev_remove_pack(struct packet_type *pt);
void __dev_remove_pack(struct packet_type *pt);
void dev_add_offload(struct packet_offload *po);
void dev_remove_offload(struct packet_offload *po);

int dev_get_iflink(const struct net_device *dev);
int dev_fill_metadata_dst(struct net_device *dev, struct sk_buff *skb);
int dev_fill_forward_path(const struct net_device *dev, const u8 *daddr,
                          struct net_device_path_stack *stack);
struct net_device *__dev_get_by_flags(struct net *net, unsigned short flags,
                                      unsigned short mask);
struct net_device *dev_get_by_name(struct net *net, const char *name);
struct net_device *dev_get_by_name_rcu(struct net *net, const char *name);
struct net_device *__dev_get_by_name(struct net *net, const char *name);
bool netdev_name_in_use(struct net *net, const char *name);
int dev_alloc_name(struct net_device *dev, const char *name);
int dev_open(struct net_device *dev, struct netlink_ext_ack *extack);
void dev_close(struct net_device *dev);
void dev_close_many(struct list_head *head, bool unlink);
void dev_disable_lro(struct net_device *dev);
int dev_loopback_xmit(struct net *net, struct sock *sk, struct sk_buff *newskb);
u16 dev_pick_tx_zero(struct net_device *dev, struct sk_buff *skb,
                     struct net_device *sb_dev);
u16 dev_pick_tx_cpu_id(struct net_device *dev, struct sk_buff *skb,
                       struct net_device *sb_dev);

int dev_queue_xmit(struct sk_buff *skb);
int dev_queue_xmit_accel(struct sk_buff *skb, struct net_device *sb_dev);
int __dev_direct_xmit(struct sk_buff *skb, u16 queue_id);

static inline int dev_direct_xmit(struct sk_buff *skb, u16 queue_id)
{
        int ret;

        ret = __dev_direct_xmit(skb, queue_id);
        if (!dev_xmit_complete(ret))
                kfree_skb(skb);
        return ret;
}

int register_netdevice(struct net_device *dev);
void unregister_netdevice_queue(struct net_device *dev, struct list_head *head);
void unregister_netdevice_many(struct list_head *head);
static inline void unregister_netdevice(struct net_device *dev)
{
        unregister_netdevice_queue(dev, NULL);
}

int netdev_refcnt_read(const struct net_device *dev);
void free_netdev(struct net_device *dev);
void netdev_freemem(struct net_device *dev);
int init_dummy_netdev(struct net_device *dev);

struct net_device *netdev_get_xmit_slave(struct net_device *dev,
                                         struct sk_buff *skb,
                                         bool all_slaves);
struct net_device *netdev_sk_get_lowest_dev(struct net_device *dev,

                                            struct sock *sk);
struct net_device *dev_get_by_index(struct net *net, int ifindex);
struct net_device *__dev_get_by_index(struct net *net, int ifindex);
struct net_device *dev_get_by_index_rcu(struct net *net, int ifindex);
struct net_device *dev_get_by_napi_id(unsigned int napi_id);
int netdev_get_name(struct net *net, char *name, int ifindex);
int dev_restart(struct net_device *dev);
int skb_gro_receive(struct sk_buff *p, struct sk_buff *skb);
int skb_gro_receive_list(struct sk_buff *p, struct sk_buff *skb);

static inline unsigned int skb_gro_offset(const struct sk_buff *skb)
{
        return NAPI_GRO_CB(skb)->data_offset;
}

static inline unsigned int skb_gro_len(const struct sk_buff *skb)
{
        return skb->len - NAPI_GRO_CB(skb)->data_offset;
}

static inline void skb_gro_pull(struct sk_buff *skb, unsigned int len)
{
        NAPI_GRO_CB(skb)->data_offset += len;
}

static inline void *skb_gro_header_fast(struct sk_buff *skb,
                                        unsigned int offset)
{
        return NAPI_GRO_CB(skb)->frag0 + offset;
}

static inline int skb_gro_header_hard(struct sk_buff *skb, unsigned int hlen)
{
        return NAPI_GRO_CB(skb)->frag0_len < hlen;
}

static inline void skb_gro_frag0_invalidate(struct sk_buff *skb)
{
        NAPI_GRO_CB(skb)->frag0 = NULL;
        NAPI_GRO_CB(skb)->frag0_len = 0;
}

static inline void *skb_gro_header_slow(struct sk_buff *skb, unsigned int hlen,
                                        unsigned int offset)
{
        if (!pskb_may_pull(skb, hlen))
                return NULL;

        skb_gro_frag0_invalidate(skb);
        return skb->data + offset;
}

static inline void *skb_gro_network_header(struct sk_buff *skb)
{
        return (NAPI_GRO_CB(skb)->frag0 ?: skb->data) +
               skb_network_offset(skb);
}

static inline void skb_gro_postpull_rcsum(struct sk_buff *skb,
                                        const void *start, unsigned int len)
{
        if (NAPI_GRO_CB(skb)->csum_valid)
                NAPI_GRO_CB(skb)->csum = csum_sub(NAPI_GRO_CB(skb)->csum,
                                                  csum_partial(start, len, 0));
}

/* GRO checksum functions. These are logical equivalents of the normal
 * checksum functions (in skbuff.h) except that they operate on the GRO
 * offsets and fields in sk_buff.
 */

__sum16 __skb_gro_checksum_complete(struct sk_buff *skb);

static inline bool skb_at_gro_remcsum_start(struct sk_buff *skb)
{
        return (NAPI_GRO_CB(skb)->gro_remcsum_start == skb_gro_offset(skb));
}

static inline bool __skb_gro_checksum_validate_needed(struct sk_buff *skb,
                                                      bool zero_okay,
                                                      __sum16 check)
{
        return ((skb->ip_summed != CHECKSUM_PARTIAL ||
                skb_checksum_start_offset(skb) <
                 skb_gro_offset(skb)) &&
                !skb_at_gro_remcsum_start(skb) &&
                NAPI_GRO_CB(skb)->csum_cnt == 0 &&
                (!zero_okay || check));
}

static inline __sum16 __skb_gro_checksum_validate_complete(struct sk_buff *skb,
                                                           __wsum psum)
{
        if (NAPI_GRO_CB(skb)->csum_valid &&
            !csum_fold(csum_add(psum, NAPI_GRO_CB(skb)->csum)))
                return 0;

        NAPI_GRO_CB(skb)->csum = psum;

        return __skb_gro_checksum_complete(skb);
}

static inline void skb_gro_incr_csum_unnecessary(struct sk_buff *skb)
{
        if (NAPI_GRO_CB(skb)->csum_cnt > 0) {
                /* Consume a checksum from CHECKSUM_UNNECESSARY */
                NAPI_GRO_CB(skb)->csum_cnt--;
        } else {
                /* Update skb for CHECKSUM_UNNECESSARY and csum_level when we
                 * verified a new top level checksum or an encapsulated one
                 * during GRO. This saves work if we fallback to normal path.
                 */
                __skb_incr_checksum_unnecessary(skb);
        }
}

#define __skb_gro_checksum_validate(skb, proto, zero_okay, check,       \
                                    compute_pseudo)                     \
({                                                                      \
        __sum16 __ret = 0;                                              \
        if (__skb_gro_checksum_validate_needed(skb, zero_okay, check))  \
                __ret = __skb_gro_checksum_validate_complete(skb,       \
                                compute_pseudo(skb, proto));            \
        if (!__ret)                                                     \
                skb_gro_incr_csum_unnecessary(skb);                     \
        __ret;                                                          \
})

#define skb_gro_checksum_validate(skb, proto, compute_pseudo)           \
        __skb_gro_checksum_validate(skb, proto, false, 0, compute_pseudo)

#define skb_gro_checksum_validate_zero_check(skb, proto, check,         \
                                             compute_pseudo)            \
        __skb_gro_checksum_validate(skb, proto, true, check, compute_pseudo)

#define skb_gro_checksum_simple_validate(skb)                           \
        __skb_gro_checksum_validate(skb, 0, false, 0, null_compute_pseudo)

static inline bool __skb_gro_checksum_convert_check(struct sk_buff *skb)
{
        return (NAPI_GRO_CB(skb)->csum_cnt == 0 &&
                !NAPI_GRO_CB(skb)->csum_valid);
}

static inline void __skb_gro_checksum_convert(struct sk_buff *skb,
                                              __wsum pseudo)
{
        NAPI_GRO_CB(skb)->csum = ~pseudo;
        NAPI_GRO_CB(skb)->csum_valid = 1;
}

#define skb_gro_checksum_try_convert(skb, proto, compute_pseudo)        \
do {                                                                    \
        if (__skb_gro_checksum_convert_check(skb))                      \
                __skb_gro_checksum_convert(skb,                         \
                                           compute_pseudo(skb, proto)); \
} while (0)

struct gro_remcsum {
        int offset;
        __wsum delta;
};

static inline void skb_gro_remcsum_init(struct gro_remcsum *grc)
{
        grc->offset = 0;
        grc->delta = 0;
}

static inline void *skb_gro_remcsum_process(struct sk_buff *skb, void *ptr,
                                            unsigned int off, size_t hdrlen,
                                            int start, int offset,
                                            struct gro_remcsum *grc,
                                            bool nopartial)
{
        __wsum delta;
        size_t plen = hdrlen + max_t(size_t, offset + sizeof(u16), start);

        BUG_ON(!NAPI_GRO_CB(skb)->csum_valid);

        if (!nopartial) {
                NAPI_GRO_CB(skb)->gro_remcsum_start = off + hdrlen + start;
                return ptr;
        }

        ptr = skb_gro_header_fast(skb, off);
        if (skb_gro_header_hard(skb, off + plen)) {
                ptr = skb_gro_header_slow(skb, off + plen, off);
                if (!ptr)
                        return NULL;
        }

        delta = remcsum_adjust(ptr + hdrlen, NAPI_GRO_CB(skb)->csum,
                               start, offset);

        /* Adjust skb->csum since we changed the packet */
        NAPI_GRO_CB(skb)->csum = csum_add(NAPI_GRO_CB(skb)->csum, delta);

        grc->offset = off + hdrlen + offset;
        grc->delta = delta;

        return ptr;
}

static inline void skb_gro_remcsum_cleanup(struct sk_buff *skb,
                                           struct gro_remcsum *grc)
{
        void *ptr;
        size_t plen = grc->offset + sizeof(u16);

        if (!grc->delta)
                return;

        ptr = skb_gro_header_fast(skb, grc->offset);
        if (skb_gro_header_hard(skb, grc->offset + sizeof(u16))) {
                ptr = skb_gro_header_slow(skb, plen, grc->offset);
                if (!ptr)
                        return;
        }

        remcsum_unadjust((__sum16 *)ptr, grc->delta);
}

#ifdef CONFIG_XFRM_OFFLOAD
static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
{
        if (PTR_ERR(pp) != -EINPROGRESS)
                NAPI_GRO_CB(skb)->flush |= flush;
}
static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
                                               struct sk_buff *pp,
                                               int flush,
                                               struct gro_remcsum *grc)
{
        if (PTR_ERR(pp) != -EINPROGRESS) {
                NAPI_GRO_CB(skb)->flush |= flush;
                skb_gro_remcsum_cleanup(skb, grc);
                skb->remcsum_offload = 0;
        }
}
#else
static inline void skb_gro_flush_final(struct sk_buff *skb, struct sk_buff *pp, int flush)
{
        NAPI_GRO_CB(skb)->flush |= flush;
}
static inline void skb_gro_flush_final_remcsum(struct sk_buff *skb,
                                               struct sk_buff *pp,
                                               int flush,
                                               struct gro_remcsum *grc)
{
        NAPI_GRO_CB(skb)->flush |= flush;
        skb_gro_remcsum_cleanup(skb, grc);
        skb->remcsum_offload = 0;
}
#endif

static inline int dev_hard_header(struct sk_buff *skb, struct net_device *dev,
                                  unsigned short type,
                                  const void *daddr, const void *saddr,
                                  unsigned int len)
{
        if (!dev->header_ops || !dev->header_ops->create)
                return 0;

        return dev->header_ops->create(skb, dev, type, daddr, saddr, len);
}

static inline int dev_parse_header(const struct sk_buff *skb,
                                   unsigned char *haddr)
{
        const struct net_device *dev = skb->dev;

        if (!dev->header_ops || !dev->header_ops->parse)
                return 0;
        return dev->header_ops->parse(skb, haddr);
}

static inline __be16 dev_parse_header_protocol(const struct sk_buff *skb)
{
        const struct net_device *dev = skb->dev;

        if (!dev->header_ops || !dev->header_ops->parse_protocol)
                return 0;
        return dev->header_ops->parse_protocol(skb);
}

/* ll_header must have at least hard_header_len allocated */
static inline bool dev_validate_header(const struct net_device *dev,
                                       char *ll_header, int len)
{
        if (likely(len >= dev->hard_header_len))
                return true;
        if (len < dev->min_header_len)
                return false;

        if (capable(CAP_SYS_RAWIO)) {
                memset(ll_header + len, 0, dev->hard_header_len - len);
                return true;
        }

        if (dev->header_ops && dev->header_ops->validate)
                return dev->header_ops->validate(ll_header, len);

        return false;
}

static inline bool dev_has_header(const struct net_device *dev)
{
        return dev->header_ops && dev->header_ops->create;
}

#ifdef CONFIG_NET_FLOW_LIMIT
#define FLOW_LIMIT_HISTORY      (1 << 7)  /* must be ^2 and !overflow buckets */
struct sd_flow_limit {
        u64                     count;
        unsigned int            num_buckets;
        unsigned int            history_head;
        u16                     history[FLOW_LIMIT_HISTORY];
        u8                      buckets[];
};

extern int netdev_flow_limit_table_len;
#endif /* CONFIG_NET_FLOW_LIMIT */

/*
 * Incoming packets are placed on per-CPU queues
 */
struct softnet_data {
        struct list_head        poll_list;
        struct sk_buff_head     process_queue;

        /* stats */
        unsigned int            processed;
        unsigned int            time_squeeze;
        unsigned int            received_rps;
#ifdef CONFIG_RPS
        struct softnet_data     *rps_ipi_list;
#endif
#ifdef CONFIG_NET_FLOW_LIMIT
        struct sd_flow_limit __rcu *flow_limit;
#endif
        struct Qdisc            *output_queue;
        struct Qdisc            **output_queue_tailp;
        struct sk_buff          *completion_queue;
#ifdef CONFIG_XFRM_OFFLOAD
        struct sk_buff_head     xfrm_backlog;
#endif
        /* written and read only by owning cpu: */
        struct {
                u16 recursion;
                u8  more;
        } xmit;
#ifdef CONFIG_RPS
        /* input_queue_head should be written by cpu owning this struct,
         * and only read by other cpus. Worth using a cache line.
         */
        unsigned int            input_queue_head ____cacheline_aligned_in_smp;

        /* Elements below can be accessed between CPUs for RPS/RFS */
        call_single_data_t      csd ____cacheline_aligned_in_smp;
        struct softnet_data     *rps_ipi_next;
        unsigned int            cpu;
        unsigned int            input_queue_tail;
#endif
        unsigned int            dropped;
        struct sk_buff_head     input_pkt_queue;
        struct napi_struct      backlog;

};

static inline void input_queue_head_incr(struct softnet_data *sd)
{
#ifdef CONFIG_RPS
        sd->input_queue_head++;
#endif
}

static inline void input_queue_tail_incr_save(struct softnet_data *sd,
                                              unsigned int *qtail)
{
#ifdef CONFIG_RPS
        *qtail = ++sd->input_queue_tail;
#endif
}

DECLARE_PER_CPU_ALIGNED(struct softnet_data, softnet_data);

static inline int dev_recursion_level(void)
{
        return this_cpu_read(softnet_data.xmit.recursion);
}

#define XMIT_RECURSION_LIMIT    8
static inline bool dev_xmit_recursion(void)
{
        return unlikely(__this_cpu_read(softnet_data.xmit.recursion) >
                        XMIT_RECURSION_LIMIT);
}

static inline void dev_xmit_recursion_inc(void)
{
        __this_cpu_inc(softnet_data.xmit.recursion);
}

static inline void dev_xmit_recursion_dec(void)
{
        __this_cpu_dec(softnet_data.xmit.recursion);
}

void __netif_schedule(struct Qdisc *q);
void netif_schedule_queue(struct netdev_queue *txq);

static inline void netif_tx_schedule_all(struct net_device *dev)
{
        unsigned int i;

        for (i = 0; i < dev->num_tx_queues; i++)
                netif_schedule_queue(netdev_get_tx_queue(dev, i));
}

static __always_inline void netif_tx_start_queue(struct netdev_queue *dev_queue)
{
        clear_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}

/**
 *      netif_start_queue - allow transmit
 *      @dev: network device
 *
 *      Allow upper layers to call the device hard_start_xmit routine.
 */
static inline void netif_start_queue(struct net_device *dev)
{
        netif_tx_start_queue(netdev_get_tx_queue(dev, 0));
}

static inline void netif_tx_start_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_start_queue(txq);
        }
}

void netif_tx_wake_queue(struct netdev_queue *dev_queue);

/**
 *      netif_wake_queue - restart transmit
 *      @dev: network device
 *
 *      Allow upper layers to call the device hard_start_xmit routine.
 *      Used for flow control when transmit resources are available.
 */
static inline void netif_wake_queue(struct net_device *dev)
{
        netif_tx_wake_queue(netdev_get_tx_queue(dev, 0));
}

static inline void netif_tx_wake_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_wake_queue(txq);
        }
}

static __always_inline void netif_tx_stop_queue(struct netdev_queue *dev_queue)
{
        set_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}

/**
 *      netif_stop_queue - stop transmitted packets
 *      @dev: network device
 *
 *      Stop upper layers calling the device hard_start_xmit routine.
 *      Used for flow control when transmit resources are unavailable.
 */
static inline void netif_stop_queue(struct net_device *dev)
{
        netif_tx_stop_queue(netdev_get_tx_queue(dev, 0));
}

void netif_tx_stop_all_queues(struct net_device *dev);

static inline bool netif_tx_queue_stopped(const struct netdev_queue *dev_queue)
{
        return test_bit(__QUEUE_STATE_DRV_XOFF, &dev_queue->state);
}

/**
 *      netif_queue_stopped - test if transmit queue is flowblocked
 *      @dev: network device
 *
 *      Test if transmit queue on device is currently unable to send.
 */
static inline bool netif_queue_stopped(const struct net_device *dev)
{
        return netif_tx_queue_stopped(netdev_get_tx_queue(dev, 0));
}

static inline bool netif_xmit_stopped(const struct netdev_queue *dev_queue)
{
        return dev_queue->state & QUEUE_STATE_ANY_XOFF;
}

static inline bool
netif_xmit_frozen_or_stopped(const struct netdev_queue *dev_queue)
{
        return dev_queue->state & QUEUE_STATE_ANY_XOFF_OR_FROZEN;
}

static inline bool
netif_xmit_frozen_or_drv_stopped(const struct netdev_queue *dev_queue)
{
        return dev_queue->state & QUEUE_STATE_DRV_XOFF_OR_FROZEN;
}

/**
 *      netdev_queue_set_dql_min_limit - set dql minimum limit
 *      @dev_queue: pointer to transmit queue
 *      @min_limit: dql minimum limit
 *
 * Forces xmit_more() to return true until the minimum threshold
 * defined by @min_limit is reached (or until the tx queue is
 * empty). Warning: to be use with care, misuse will impact the
 * latency.
 */
static inline void netdev_queue_set_dql_min_limit(struct netdev_queue *dev_queue,
                                                  unsigned int min_limit)
{
#ifdef CONFIG_BQL
        dev_queue->dql.min_limit = min_limit;
#endif
}

/**
 *      netdev_txq_bql_enqueue_prefetchw - prefetch bql data for write
 *      @dev_queue: pointer to transmit queue
 *
 * BQL enabled drivers might use this helper in their ndo_start_xmit(),
 * to give appropriate hint to the CPU.
 */
static inline void netdev_txq_bql_enqueue_prefetchw(struct netdev_queue *dev_queue)
{
#ifdef CONFIG_BQL
        prefetchw(&dev_queue->dql.num_queued);
#endif
}

/**
 *      netdev_txq_bql_complete_prefetchw - prefetch bql data for write
 *      @dev_queue: pointer to transmit queue
 *
 * BQL enabled drivers might use this helper in their TX completion path,
 * to give appropriate hint to the CPU.
 */
static inline void netdev_txq_bql_complete_prefetchw(struct netdev_queue *dev_queue)
{
#ifdef CONFIG_BQL
        prefetchw(&dev_queue->dql.limit);
#endif
}

static inline void netdev_tx_sent_queue(struct netdev_queue *dev_queue,
                                        unsigned int bytes)
{
#ifdef CONFIG_BQL
        dql_queued(&dev_queue->dql, bytes);

        if (likely(dql_avail(&dev_queue->dql) >= 0))
                return;

        set_bit(__QUEUE_STATE_STACK_XOFF, &dev_queue->state);

        /*
         * The XOFF flag must be set before checking the dql_avail below,
         * because in netdev_tx_completed_queue we update the dql_completed
         * before checking the XOFF flag.
         */
        smp_mb();

        /* check again in case another CPU has just made room avail */
        if (unlikely(dql_avail(&dev_queue->dql) >= 0))
                clear_bit(__QUEUE_STATE_STACK_XOFF, &dev_queue->state);
#endif
}

/* Variant of netdev_tx_sent_queue() for drivers that are aware
 * that they should not test BQL status themselves.
 * We do want to change __QUEUE_STATE_STACK_XOFF only for the last
 * skb of a batch.
 * Returns true if the doorbell must be used to kick the NIC.
 */
static inline bool __netdev_tx_sent_queue(struct netdev_queue *dev_queue,
                                          unsigned int bytes,
                                          bool xmit_more)
{
        if (xmit_more) {
#ifdef CONFIG_BQL
                dql_queued(&dev_queue->dql, bytes);
#endif
                return netif_tx_queue_stopped(dev_queue);
        }
        netdev_tx_sent_queue(dev_queue, bytes);
        return true;
}

/**
 *      netdev_sent_queue - report the number of bytes queued to hardware
 *      @dev: network device
 *      @bytes: number of bytes queued to the hardware device queue
 *
 *      Report the number of bytes queued for sending/completion to the network
 *      device hardware queue. @bytes should be a good approximation and should
 *      exactly match netdev_completed_queue() @bytes
 */
static inline void netdev_sent_queue(struct net_device *dev, unsigned int bytes)
{
        netdev_tx_sent_queue(netdev_get_tx_queue(dev, 0), bytes);
}

static inline bool __netdev_sent_queue(struct net_device *dev,
                                       unsigned int bytes,
                                       bool xmit_more)
{
        return __netdev_tx_sent_queue(netdev_get_tx_queue(dev, 0), bytes,
                                      xmit_more);
}

static inline void netdev_tx_completed_queue(struct netdev_queue *dev_queue,
                                             unsigned int pkts, unsigned int bytes)
{
#ifdef CONFIG_BQL
        if (unlikely(!bytes))
                return;

        dql_completed(&dev_queue->dql, bytes);

        /*
         * Without the memory barrier there is a small possiblity that
         * netdev_tx_sent_queue will miss the update and cause the queue to
         * be stopped forever
         */
        smp_mb();

        if (unlikely(dql_avail(&dev_queue->dql) < 0))
                return;

        if (test_and_clear_bit(__QUEUE_STATE_STACK_XOFF, &dev_queue->state))
                netif_schedule_queue(dev_queue);
#endif
}

/**
 *      netdev_completed_queue - report bytes and packets completed by device
 *      @dev: network device
 *      @pkts: actual number of packets sent over the medium
 *      @bytes: actual number of bytes sent over the medium
 *
 *      Report the number of bytes and packets transmitted by the network device
 *      hardware queue over the physical medium, @bytes must exactly match the
 *      @bytes amount passed to netdev_sent_queue()
 */
static inline void netdev_completed_queue(struct net_device *dev,
                                          unsigned int pkts, unsigned int bytes)
{
        netdev_tx_completed_queue(netdev_get_tx_queue(dev, 0), pkts, bytes);
}

static inline void netdev_tx_reset_queue(struct netdev_queue *q)
{
#ifdef CONFIG_BQL
        clear_bit(__QUEUE_STATE_STACK_XOFF, &q->state);
        dql_reset(&q->dql);
#endif
}

/**
 *      netdev_reset_queue - reset the packets and bytes count of a network device
 *      @dev_queue: network device
 *
 *      Reset the bytes and packet count of a network device and clear the
 *      software flow control OFF bit for this network device
 */
static inline void netdev_reset_queue(struct net_device *dev_queue)
{
        netdev_tx_reset_queue(netdev_get_tx_queue(dev_queue, 0));
}

/**
 *      netdev_cap_txqueue - check if selected tx queue exceeds device queues
 *      @dev: network device
 *      @queue_index: given tx queue index
 *
 *      Returns 0 if given tx queue index >= number of device tx queues,
 *      otherwise returns the originally passed tx queue index.
 */
static inline u16 netdev_cap_txqueue(struct net_device *dev, u16 queue_index)
{
        if (unlikely(queue_index >= dev->real_num_tx_queues)) {
                net_warn_ratelimited("%s selects TX queue %d, but real number of TX queues is %d\n",
                                     dev->name, queue_index,
                                     dev->real_num_tx_queues);
                return 0;
        }

        return queue_index;
}

/**
 *      netif_running - test if up
 *      @dev: network device
 *
 *      Test if the device has been brought up.
 */
static inline bool netif_running(const struct net_device *dev)
{
        return test_bit(__LINK_STATE_START, &dev->state);
}

/*
 * Routines to manage the subqueues on a device.  We only need start,
 * stop, and a check if it's stopped.  All other device management is
 * done at the overall netdevice level.
 * Also test the device if we're multiqueue.
 */

/**
 *      netif_start_subqueue - allow sending packets on subqueue
 *      @dev: network device
 *      @queue_index: sub queue index
 *
 * Start individual transmit queue of a device with multiple transmit queues.
 */
static inline void netif_start_subqueue(struct net_device *dev, u16 queue_index)
{
        struct netdev_queue *txq = netdev_get_tx_queue(dev, queue_index);

        netif_tx_start_queue(txq);
}

/**
 *      netif_stop_subqueue - stop sending packets on subqueue
 *      @dev: network device
 *      @queue_index: sub queue index
 *
 * Stop individual transmit queue of a device with multiple transmit queues.
 */
static inline void netif_stop_subqueue(struct net_device *dev, u16 queue_index)
{
        struct netdev_queue *txq = netdev_get_tx_queue(dev, queue_index);
        netif_tx_stop_queue(txq);
}

/**
 *      __netif_subqueue_stopped - test status of subqueue
 *      @dev: network device
 *      @queue_index: sub queue index
 *
 * Check individual transmit queue of a device with multiple transmit queues.
 */
static inline bool __netif_subqueue_stopped(const struct net_device *dev,
                                            u16 queue_index)
{
        struct netdev_queue *txq = netdev_get_tx_queue(dev, queue_index);

        return netif_tx_queue_stopped(txq);
}

/**
 *      netif_subqueue_stopped - test status of subqueue
 *      @dev: network device
 *      @skb: sub queue buffer pointer
 *
 * Check individual transmit queue of a device with multiple transmit queues.
 */
static inline bool netif_subqueue_stopped(const struct net_device *dev,
                                          struct sk_buff *skb)
{
        return __netif_subqueue_stopped(dev, skb_get_queue_mapping(skb));
}

/**
 *      netif_wake_subqueue - allow sending packets on subqueue
 *      @dev: network device
 *      @queue_index: sub queue index
 *
 * Resume individual transmit queue of a device with multiple transmit queues.
 */
static inline void netif_wake_subqueue(struct net_device *dev, u16 queue_index)
{
        struct netdev_queue *txq = netdev_get_tx_queue(dev, queue_index);

        netif_tx_wake_queue(txq);
}

#ifdef CONFIG_XPS
int netif_set_xps_queue(struct net_device *dev, const struct cpumask *mask,
                        u16 index);
int __netif_set_xps_queue(struct net_device *dev, const unsigned long *mask,
                          u16 index, enum xps_map_type type);

/**
 *      netif_attr_test_mask - Test a CPU or Rx queue set in a mask
 *      @j: CPU/Rx queue index
 *      @mask: bitmask of all cpus/rx queues
 *      @nr_bits: number of bits in the bitmask
 *
 * Test if a CPU or Rx queue index is set in a mask of all CPU/Rx queues.
 */
static inline bool netif_attr_test_mask(unsigned long j,
                                        const unsigned long *mask,
                                        unsigned int nr_bits)
{
        cpu_max_bits_warn(j, nr_bits);
        return test_bit(j, mask);
}

/**
 *      netif_attr_test_online - Test for online CPU/Rx queue
 *      @j: CPU/Rx queue index
 *      @online_mask: bitmask for CPUs/Rx queues that are online
 *      @nr_bits: number of bits in the bitmask
 *
 * Returns true if a CPU/Rx queue is online.
 */
static inline bool netif_attr_test_online(unsigned long j,
                                          const unsigned long *online_mask,
                                          unsigned int nr_bits)
{
        cpu_max_bits_warn(j, nr_bits);

        if (online_mask)
                return test_bit(j, online_mask);

        return (j < nr_bits);
}

/**
 *      netif_attrmask_next - get the next CPU/Rx queue in a cpu/Rx queues mask
 *      @n: CPU/Rx queue index
 *      @srcp: the cpumask/Rx queue mask pointer
 *      @nr_bits: number of bits in the bitmask
 *
 * Returns >= nr_bits if no further CPUs/Rx queues set.
 */
static inline unsigned int netif_attrmask_next(int n, const unsigned long *srcp,
                                               unsigned int nr_bits)
{
        /* -1 is a legal arg here. */
        if (n != -1)
                cpu_max_bits_warn(n, nr_bits);

        if (srcp)
                return find_next_bit(srcp, nr_bits, n + 1);

        return n + 1;
}

/**
 *      netif_attrmask_next_and - get the next CPU/Rx queue in \*src1p & \*src2p
 *      @n: CPU/Rx queue index
 *      @src1p: the first CPUs/Rx queues mask pointer
 *      @src2p: the second CPUs/Rx queues mask pointer
 *      @nr_bits: number of bits in the bitmask
 *
 * Returns >= nr_bits if no further CPUs/Rx queues set in both.
 */
static inline int netif_attrmask_next_and(int n, const unsigned long *src1p,
                                          const unsigned long *src2p,
                                          unsigned int nr_bits)
{
        /* -1 is a legal arg here. */
        if (n != -1)
                cpu_max_bits_warn(n, nr_bits);

        if (src1p && src2p)
                return find_next_and_bit(src1p, src2p, nr_bits, n + 1);
        else if (src1p)
                return find_next_bit(src1p, nr_bits, n + 1);
        else if (src2p)
                return find_next_bit(src2p, nr_bits, n + 1);

        return n + 1;
}
#else
static inline int netif_set_xps_queue(struct net_device *dev,
                                      const struct cpumask *mask,
                                      u16 index)
{
        return 0;
}

static inline int __netif_set_xps_queue(struct net_device *dev,
                                        const unsigned long *mask,
                                        u16 index, enum xps_map_type type)
{
        return 0;
}
#endif

/**
 *      netif_is_multiqueue - test if device has multiple transmit queues
 *      @dev: network device
 *
 * Check if device has multiple transmit queues
 */
static inline bool netif_is_multiqueue(const struct net_device *dev)
{
        return dev->num_tx_queues > 1;
}

int netif_set_real_num_tx_queues(struct net_device *dev, unsigned int txq);

#ifdef CONFIG_SYSFS
int netif_set_real_num_rx_queues(struct net_device *dev, unsigned int rxq);
#else
static inline int netif_set_real_num_rx_queues(struct net_device *dev,
                                                unsigned int rxqs)
{
        dev->real_num_rx_queues = rxqs;
        return 0;
}
#endif
int netif_set_real_num_queues(struct net_device *dev,
                              unsigned int txq, unsigned int rxq);

static inline struct netdev_rx_queue *
__netif_get_rx_queue(struct net_device *dev, unsigned int rxq)
{
        return dev->_rx + rxq;
}

#ifdef CONFIG_SYSFS
static inline unsigned int get_netdev_rx_queue_index(
                struct netdev_rx_queue *queue)
{
        struct net_device *dev = queue->dev;
        int index = queue - dev->_rx;

        BUG_ON(index >= dev->num_rx_queues);
        return index;
}
#endif

#define DEFAULT_MAX_NUM_RSS_QUEUES      (8)
int netif_get_num_default_rss_queues(void);

enum skb_free_reason {
        SKB_REASON_CONSUMED,
        SKB_REASON_DROPPED,
};

void __dev_kfree_skb_irq(struct sk_buff *skb, enum skb_free_reason reason);
void __dev_kfree_skb_any(struct sk_buff *skb, enum skb_free_reason reason);

/*
 * It is not allowed to call kfree_skb() or consume_skb() from hardware
 * interrupt context or with hardware interrupts being disabled.
 * (in_hardirq() || irqs_disabled())
 *
 * We provide four helpers that can be used in following contexts :
 *
 * dev_kfree_skb_irq(skb) when caller drops a packet from irq context,
 *  replacing kfree_skb(skb)
 *
 * dev_consume_skb_irq(skb) when caller consumes a packet from irq context.
 *  Typically used in place of consume_skb(skb) in TX completion path
 *
 * dev_kfree_skb_any(skb) when caller doesn't know its current irq context,
 *  replacing kfree_skb(skb)
 *
 * dev_consume_skb_any(skb) when caller doesn't know its current irq context,
 *  and consumed a packet. Used in place of consume_skb(skb)
 */
static inline void dev_kfree_skb_irq(struct sk_buff *skb)
{
        __dev_kfree_skb_irq(skb, SKB_REASON_DROPPED);
}

static inline void dev_consume_skb_irq(struct sk_buff *skb)
{
        __dev_kfree_skb_irq(skb, SKB_REASON_CONSUMED);
}

static inline void dev_kfree_skb_any(struct sk_buff *skb)
{
        __dev_kfree_skb_any(skb, SKB_REASON_DROPPED);
}

static inline void dev_consume_skb_any(struct sk_buff *skb)
{
        __dev_kfree_skb_any(skb, SKB_REASON_CONSUMED);
}