// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (c) 2007 Patrick McHardy <kaber@trash.net>
 *
 * The code this is based on carried the following copyright notice:
 * ---
 * (C) Copyright 2001-2006
 * Alex Zeffertt, Cambridge Broadband Ltd, ajz@cambridgebroadband.com
 * Re-worked by Ben Greear <greearb@candelatech.com>
 * ---
 */
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/rculist.h>
#include <linux/notifier.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/net_tstamp.h>
#include <linux/ethtool.h>
#include <linux/if_arp.h>
#include <linux/if_vlan.h>
#include <linux/if_link.h>
#include <linux/if_macvlan.h>
#include <linux/hash.h>
#include <linux/workqueue.h>
#include <net/netdev_lock.h>
#include <net/rtnetlink.h>
#include <net/xfrm.h>
#include <linux/netpoll.h>
#include <linux/phy.h>

#define MACVLAN_HASH_BITS       8
#define MACVLAN_HASH_SIZE       (1<<MACVLAN_HASH_BITS)
#define MACVLAN_DEFAULT_BC_QUEUE_LEN    1000

#define MACVLAN_F_PASSTHRU      1
#define MACVLAN_F_ADDRCHANGE    2

struct macvlan_port {
        struct net_device       *dev;
        struct hlist_head       vlan_hash[MACVLAN_HASH_SIZE];
        struct list_head        vlans;
        struct sk_buff_head     bc_queue;
        struct work_struct      bc_work;
        u32                     bc_queue_len_used;
        int                     bc_cutoff;
        u32                     flags;
        int                     count;
        struct hlist_head       vlan_source_hash[MACVLAN_HASH_SIZE];
        DECLARE_BITMAP(bc_filter, MACVLAN_MC_FILTER_SZ);
        DECLARE_BITMAP(mc_filter, MACVLAN_MC_FILTER_SZ);
        unsigned char           perm_addr[ETH_ALEN];
};

struct macvlan_source_entry {
        struct hlist_node       hlist;
        struct macvlan_dev __rcu *vlan;
        unsigned char           addr[6+2] __aligned(sizeof(u16));
        struct rcu_head         rcu;
};

struct macvlan_skb_cb {
        const struct macvlan_dev *src;
};

#define MACVLAN_SKB_CB(__skb) ((struct macvlan_skb_cb *)&((__skb)->cb[0]))

static void macvlan_port_destroy(struct net_device *dev);
static void update_port_bc_queue_len(struct macvlan_port *port);

static inline bool macvlan_passthru(const struct macvlan_port *port)
{
        return port->flags & MACVLAN_F_PASSTHRU;
}

static inline void macvlan_set_passthru(struct macvlan_port *port)
{
        port->flags |= MACVLAN_F_PASSTHRU;
}

static inline bool macvlan_addr_change(const struct macvlan_port *port)
{
        return port->flags & MACVLAN_F_ADDRCHANGE;
}

static inline void macvlan_set_addr_change(struct macvlan_port *port)
{
        port->flags |= MACVLAN_F_ADDRCHANGE;
}

static inline void macvlan_clear_addr_change(struct macvlan_port *port)
{
        port->flags &= ~MACVLAN_F_ADDRCHANGE;
}

/* Hash Ethernet address */
static u32 macvlan_eth_hash(const unsigned char *addr)
{
        u64 value = get_unaligned((u64 *)addr);

        /* only want 6 bytes */
#ifdef __BIG_ENDIAN
        value >>= 16;
#else
        value <<= 16;
#endif
        return hash_64(value, MACVLAN_HASH_BITS);
}

static struct macvlan_port *macvlan_port_get_rcu(const struct net_device *dev)
{
        return rcu_dereference(dev->rx_handler_data);
}

static struct macvlan_port *macvlan_port_get_rtnl(const struct net_device *dev)
{
        return rtnl_dereference(dev->rx_handler_data);
}

static struct macvlan_dev *macvlan_hash_lookup(const struct macvlan_port *port,
                                               const unsigned char *addr)
{
        struct macvlan_dev *vlan;
        u32 idx = macvlan_eth_hash(addr);

        hlist_for_each_entry_rcu(vlan, &port->vlan_hash[idx], hlist,
                                 lockdep_rtnl_is_held()) {
                if (ether_addr_equal_64bits(vlan->dev->dev_addr, addr))
                        return vlan;
        }
        return NULL;
}

static struct macvlan_source_entry *macvlan_hash_lookup_source(
        const struct macvlan_dev *vlan,
        const unsigned char *addr)
{
        struct macvlan_source_entry *entry;
        u32 idx = macvlan_eth_hash(addr);
        struct hlist_head *h = &vlan->port->vlan_source_hash[idx];

        hlist_for_each_entry_rcu(entry, h, hlist, lockdep_rtnl_is_held()) {
                if (ether_addr_equal_64bits(entry->addr, addr) &&
                    rcu_access_pointer(entry->vlan) == vlan)
                        return entry;
        }
        return NULL;
}

static int macvlan_hash_add_source(struct macvlan_dev *vlan,
                                   const unsigned char *addr)
{
        struct macvlan_port *port = vlan->port;
        struct macvlan_source_entry *entry;
        struct hlist_head *h;

        entry = macvlan_hash_lookup_source(vlan, addr);
        if (entry)
                return 0;

        entry = kmalloc_obj(*entry);
        if (!entry)
                return -ENOMEM;

        ether_addr_copy(entry->addr, addr);
        RCU_INIT_POINTER(entry->vlan, vlan);
        h = &port->vlan_source_hash[macvlan_eth_hash(addr)];
        hlist_add_head_rcu(&entry->hlist, h);
        vlan->macaddr_count++;

        return 0;
}

static void macvlan_hash_add(struct macvlan_dev *vlan)
{
        struct macvlan_port *port = vlan->port;
        const unsigned char *addr = vlan->dev->dev_addr;
        u32 idx = macvlan_eth_hash(addr);

        hlist_add_head_rcu(&vlan->hlist, &port->vlan_hash[idx]);
}

static void macvlan_hash_del_source(struct macvlan_source_entry *entry)
{
        RCU_INIT_POINTER(entry->vlan, NULL);
        hlist_del_rcu(&entry->hlist);
        kfree_rcu(entry, rcu);
}

static void macvlan_hash_del(struct macvlan_dev *vlan, bool sync)
{
        hlist_del_rcu(&vlan->hlist);
        if (sync)
                synchronize_rcu();
}

static void macvlan_hash_change_addr(struct macvlan_dev *vlan,
                                        const unsigned char *addr)
{
        macvlan_hash_del(vlan, true);
        /* Now that we are unhashed it is safe to change the device
         * address without confusing packet delivery.
         */
        eth_hw_addr_set(vlan->dev, addr);
        macvlan_hash_add(vlan);
}

static bool macvlan_addr_busy(const struct macvlan_port *port,
                              const unsigned char *addr)
{
        /* Test to see if the specified address is
         * currently in use by the underlying device or
         * another macvlan.
         */
        if (!macvlan_passthru(port) && !macvlan_addr_change(port) &&
            ether_addr_equal_64bits(port->dev->dev_addr, addr))
                return true;

        if (macvlan_hash_lookup(port, addr))
                return true;

        return false;
}


static int macvlan_broadcast_one(struct sk_buff *skb,
                                 const struct macvlan_dev *vlan,
                                 const struct ethhdr *eth, bool local)
{
        struct net_device *dev = vlan->dev;

        if (local)
                return __dev_forward_skb(dev, skb);

        skb->dev = dev;
        if (ether_addr_equal_64bits(eth->h_dest, dev->broadcast))
                skb->pkt_type = PACKET_BROADCAST;
        else
                skb->pkt_type = PACKET_MULTICAST;

        return 0;
}

static u32 macvlan_hash_mix(const struct macvlan_dev *vlan)
{
        return (u32)(((unsigned long)vlan) >> L1_CACHE_SHIFT);
}


static unsigned int mc_hash(const struct macvlan_dev *vlan,
                            const unsigned char *addr)
{
        u32 val = get_unaligned((u32 *)(addr + 2));

        val ^= macvlan_hash_mix(vlan);
        return hash_32(val, MACVLAN_MC_FILTER_BITS);
}

static void macvlan_broadcast(struct sk_buff *skb,
                              const struct macvlan_port *port,
                              struct net_device *src,
                              enum macvlan_mode mode)
{
        const struct ethhdr *eth = eth_hdr(skb);
        const struct macvlan_dev *vlan;
        struct sk_buff *nskb;
        unsigned int i;
        int err;
        unsigned int hash;

        if (skb->protocol == htons(ETH_P_PAUSE))
                return;

        hash_for_each_rcu(port->vlan_hash, i, vlan, hlist) {
                if (vlan->dev == src || !(vlan->mode & mode))
                        continue;

                hash = mc_hash(vlan, eth->h_dest);
                if (!test_bit(hash, vlan->mc_filter))
                        continue;

                err = NET_RX_DROP;
                nskb = skb_clone(skb, GFP_ATOMIC);
                if (likely(nskb))
                        err = macvlan_broadcast_one(nskb, vlan, eth,
                                        mode == MACVLAN_MODE_BRIDGE) ?:
                              netif_rx(nskb);
                macvlan_count_rx(vlan, skb->len + ETH_HLEN,
                                 err == NET_RX_SUCCESS, true);
        }
}

static void macvlan_multicast_rx(const struct macvlan_port *port,
                                 const struct macvlan_dev *src,
                                 struct sk_buff *skb)
{
        if (!src)
                /* frame comes from an external address */
                macvlan_broadcast(skb, port, NULL,
                                  MACVLAN_MODE_PRIVATE |
                                  MACVLAN_MODE_VEPA    |
                                  MACVLAN_MODE_PASSTHRU|
                                  MACVLAN_MODE_BRIDGE);
        else if (src->mode == MACVLAN_MODE_VEPA)
                /* flood to everyone except source */
                macvlan_broadcast(skb, port, src->dev,
                                  MACVLAN_MODE_VEPA |
                                  MACVLAN_MODE_BRIDGE);
        else
                /*
                 * flood only to VEPA ports, bridge ports
                 * already saw the frame on the way out.
                 */
                macvlan_broadcast(skb, port, src->dev,
                                  MACVLAN_MODE_VEPA);
}

static void macvlan_process_broadcast(struct work_struct *w)
{
        struct macvlan_port *port = container_of(w, struct macvlan_port,
                                                 bc_work);
        struct sk_buff *skb;
        struct sk_buff_head list;

        __skb_queue_head_init(&list);

        spin_lock_bh(&port->bc_queue.lock);
        skb_queue_splice_tail_init(&port->bc_queue, &list);
        spin_unlock_bh(&port->bc_queue.lock);

        while ((skb = __skb_dequeue(&list))) {
                const struct macvlan_dev *src = MACVLAN_SKB_CB(skb)->src;

                rcu_read_lock();
                macvlan_multicast_rx(port, src, skb);
                rcu_read_unlock();

                if (src)
                        dev_put(src->dev);
                consume_skb(skb);

                cond_resched();
        }
}

static void macvlan_broadcast_enqueue(struct macvlan_port *port,
                                      const struct macvlan_dev *src,
                                      struct sk_buff *skb)
{
        struct sk_buff *nskb;
        int err = -ENOMEM;

        nskb = skb_clone(skb, GFP_ATOMIC);
        if (!nskb)
                goto err;

        MACVLAN_SKB_CB(nskb)->src = src;

        spin_lock(&port->bc_queue.lock);
        if (skb_queue_len(&port->bc_queue) < port->bc_queue_len_used) {
                if (src)
                        dev_hold(src->dev);
                __skb_queue_tail(&port->bc_queue, nskb);
                err = 0;
        }
        spin_unlock(&port->bc_queue.lock);

        queue_work(system_dfl_wq, &port->bc_work);

        if (err)
                goto free_nskb;

        return;

free_nskb:
        kfree_skb(nskb);
err:
        dev_core_stats_rx_dropped_inc(skb->dev);
}

static void macvlan_flush_sources(struct macvlan_port *port,
                                  struct macvlan_dev *vlan)
{
        struct macvlan_source_entry *entry;
        struct hlist_node *next;
        int i;

        hash_for_each_safe(port->vlan_source_hash, i, next, entry, hlist)
                if (rcu_access_pointer(entry->vlan) == vlan)
                        macvlan_hash_del_source(entry);

        vlan->macaddr_count = 0;
}

static void macvlan_forward_source_one(struct sk_buff *skb,
                                       struct macvlan_dev *vlan)
{
        struct sk_buff *nskb;
        struct net_device *dev;
        int len;
        int ret;

        dev = vlan->dev;
        if (unlikely(!(dev->flags & IFF_UP)))
                return;

        nskb = skb_clone(skb, GFP_ATOMIC);
        if (!nskb)
                return;

        len = nskb->len + ETH_HLEN;
        nskb->dev = dev;

        if (ether_addr_equal_64bits(eth_hdr(skb)->h_dest, dev->dev_addr))
                nskb->pkt_type = PACKET_HOST;

        ret = __netif_rx(nskb);
        macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, false);
}

static bool macvlan_forward_source(struct sk_buff *skb,
                                   struct macvlan_port *port,
                                   const unsigned char *addr)
{
        struct macvlan_source_entry *entry;
        u32 idx = macvlan_eth_hash(addr);
        struct hlist_head *h = &port->vlan_source_hash[idx];
        bool consume = false;

        hlist_for_each_entry_rcu(entry, h, hlist) {
                if (ether_addr_equal_64bits(entry->addr, addr)) {
                        struct macvlan_dev *vlan = rcu_dereference(entry->vlan);

                        if (!vlan)
                                continue;

                        if (vlan->flags & MACVLAN_FLAG_NODST)
                                consume = true;
                        macvlan_forward_source_one(skb, vlan);
                }
        }

        return consume;
}

/* called under rcu_read_lock() from netif_receive_skb */
static rx_handler_result_t macvlan_handle_frame(struct sk_buff **pskb)
{
        struct macvlan_port *port;
        struct sk_buff *skb = *pskb;
        const struct ethhdr *eth = eth_hdr(skb);
        const struct macvlan_dev *vlan;
        const struct macvlan_dev *src;
        struct net_device *dev;
        unsigned int len = 0;
        int ret;
        rx_handler_result_t handle_res;

        /* Packets from dev_loopback_xmit() do not have L2 header, bail out */
        if (unlikely(skb->pkt_type == PACKET_LOOPBACK))
                return RX_HANDLER_PASS;

        port = macvlan_port_get_rcu(skb->dev);
        if (is_multicast_ether_addr(eth->h_dest)) {
                unsigned int hash;

                skb = ip_check_defrag(dev_net(skb->dev), skb, IP_DEFRAG_MACVLAN);
                if (!skb)
                        return RX_HANDLER_CONSUMED;
                *pskb = skb;
                eth = eth_hdr(skb);
                if (macvlan_forward_source(skb, port, eth->h_source)) {
                        kfree_skb(skb);
                        return RX_HANDLER_CONSUMED;
                }
                src = macvlan_hash_lookup(port, eth->h_source);
                if (src && src->mode != MACVLAN_MODE_VEPA &&
                    src->mode != MACVLAN_MODE_BRIDGE) {
                        /* forward to original port. */
                        vlan = src;
                        ret = macvlan_broadcast_one(skb, vlan, eth, 0) ?:
                              __netif_rx(skb);
                        handle_res = RX_HANDLER_CONSUMED;
                        goto out;
                }

                hash = mc_hash(NULL, eth->h_dest);
                if (test_bit(hash, port->bc_filter))
                        macvlan_broadcast_enqueue(port, src, skb);
                else if (test_bit(hash, port->mc_filter))
                        macvlan_multicast_rx(port, src, skb);

                return RX_HANDLER_PASS;
        }

        if (macvlan_forward_source(skb, port, eth->h_source)) {
                kfree_skb(skb);
                return RX_HANDLER_CONSUMED;
        }
        if (macvlan_passthru(port))
                vlan = list_first_or_null_rcu(&port->vlans,
                                              struct macvlan_dev, list);
        else
                vlan = macvlan_hash_lookup(port, eth->h_dest);
        if (!vlan || vlan->mode == MACVLAN_MODE_SOURCE)
                return RX_HANDLER_PASS;

        dev = vlan->dev;
        if (unlikely(!(dev->flags & IFF_UP))) {
                kfree_skb(skb);
                return RX_HANDLER_CONSUMED;
        }
        len = skb->len + ETH_HLEN;
        skb = skb_share_check(skb, GFP_ATOMIC);
        if (!skb) {
                ret = NET_RX_DROP;
                handle_res = RX_HANDLER_CONSUMED;
                goto out;
        }

        *pskb = skb;
        skb->dev = dev;
        skb->pkt_type = PACKET_HOST;

        ret = NET_RX_SUCCESS;
        handle_res = RX_HANDLER_ANOTHER;
out:
        macvlan_count_rx(vlan, len, ret == NET_RX_SUCCESS, false);
        return handle_res;
}

static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
{
        const struct macvlan_dev *vlan = netdev_priv(dev);
        const struct macvlan_port *port = vlan->port;
        const struct macvlan_dev *dest;

        if (vlan->mode == MACVLAN_MODE_BRIDGE) {
                const struct ethhdr *eth = skb_eth_hdr(skb);

                /* send to other bridge ports directly */
                if (is_multicast_ether_addr(eth->h_dest)) {
                        skb_reset_mac_header(skb);
                        macvlan_broadcast(skb, port, dev, MACVLAN_MODE_BRIDGE);
                        goto xmit_world;
                }

                dest = macvlan_hash_lookup(port, eth->h_dest);
                if (dest && dest->mode == MACVLAN_MODE_BRIDGE) {
                        /* send to lowerdev first for its network taps */
                        dev_forward_skb(vlan->lowerdev, skb);

                        return NET_XMIT_SUCCESS;
                }
        }
xmit_world:
        skb->dev = vlan->lowerdev;
        return dev_queue_xmit_accel(skb,
                                    netdev_get_sb_channel(dev) ? dev : NULL);
}

static inline netdev_tx_t macvlan_netpoll_send_skb(struct macvlan_dev *vlan, struct sk_buff *skb)
{
#ifdef CONFIG_NET_POLL_CONTROLLER
        return netpoll_send_skb(vlan->netpoll, skb);
#else
        BUG();
        return NETDEV_TX_OK;
#endif
}

static netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
                                      struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        unsigned int len = skb->len;
        int ret;

        if (unlikely(netpoll_tx_running(dev)))
                return macvlan_netpoll_send_skb(vlan, skb);

        ret = macvlan_queue_xmit(skb, dev);

        if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
                struct vlan_pcpu_stats *pcpu_stats;

                pcpu_stats = this_cpu_ptr(vlan->pcpu_stats);
                u64_stats_update_begin(&pcpu_stats->syncp);
                u64_stats_inc(&pcpu_stats->tx_packets);
                u64_stats_add(&pcpu_stats->tx_bytes, len);
                u64_stats_update_end(&pcpu_stats->syncp);
        } else {
                this_cpu_inc(vlan->pcpu_stats->tx_dropped);
        }
        return ret;
}

static int macvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
                               unsigned short type, const void *daddr,
                               const void *saddr, unsigned len)
{
        const struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;

        return dev_hard_header(skb, lowerdev, type, daddr,
                               saddr ? : dev->dev_addr, len);
}

static const struct header_ops macvlan_hard_header_ops = {
        .create         = macvlan_hard_header,
        .parse          = eth_header_parse,
        .cache          = eth_header_cache,
        .cache_update   = eth_header_cache_update,
        .parse_protocol = eth_header_parse_protocol,
};

static int macvlan_open(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;
        int err;

        if (macvlan_passthru(vlan->port)) {
                if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC)) {
                        err = dev_set_promiscuity(lowerdev, 1);
                        if (err < 0)
                                goto out;
                }
                goto hash_add;
        }

        err = -EADDRINUSE;
        if (macvlan_addr_busy(vlan->port, dev->dev_addr))
                goto out;

        /* Attempt to populate accel_priv which is used to offload the L2
         * forwarding requests for unicast packets.
         */
        if (lowerdev->features & NETIF_F_HW_L2FW_DOFFLOAD)
                vlan->accel_priv =
                      lowerdev->netdev_ops->ndo_dfwd_add_station(lowerdev, dev);

        /* If earlier attempt to offload failed, or accel_priv is not
         * populated we must add the unicast address to the lower device.
         */
        if (IS_ERR_OR_NULL(vlan->accel_priv)) {
                vlan->accel_priv = NULL;
                err = dev_uc_add(lowerdev, dev->dev_addr);
                if (err < 0)
                        goto out;
        }

        if (dev->flags & IFF_ALLMULTI) {
                err = dev_set_allmulti(lowerdev, 1);
                if (err < 0)
                        goto del_unicast;
        }

        if (dev->flags & IFF_PROMISC) {
                err = dev_set_promiscuity(lowerdev, 1);
                if (err < 0)
                        goto clear_multi;
        }

hash_add:
        macvlan_hash_add(vlan);
        return 0;

clear_multi:
        if (dev->flags & IFF_ALLMULTI)
                dev_set_allmulti(lowerdev, -1);
del_unicast:
        if (vlan->accel_priv) {
                lowerdev->netdev_ops->ndo_dfwd_del_station(lowerdev,
                                                           vlan->accel_priv);
                vlan->accel_priv = NULL;
        } else {
                dev_uc_del(lowerdev, dev->dev_addr);
        }
out:
        return err;
}

static int macvlan_stop(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;

        if (vlan->accel_priv) {
                lowerdev->netdev_ops->ndo_dfwd_del_station(lowerdev,
                                                           vlan->accel_priv);
                vlan->accel_priv = NULL;
        }

        dev_uc_unsync(lowerdev, dev);
        dev_mc_unsync(lowerdev, dev);

        if (macvlan_passthru(vlan->port)) {
                if (!(vlan->flags & MACVLAN_FLAG_NOPROMISC))
                        dev_set_promiscuity(lowerdev, -1);
                goto hash_del;
        }

        if (dev->flags & IFF_ALLMULTI)
                dev_set_allmulti(lowerdev, -1);

        if (dev->flags & IFF_PROMISC)
                dev_set_promiscuity(lowerdev, -1);

        dev_uc_del(lowerdev, dev->dev_addr);

hash_del:
        macvlan_hash_del(vlan, !dev->dismantle);
        return 0;
}

static int macvlan_sync_address(struct net_device *dev,
                                const unsigned char *addr)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;
        struct macvlan_port *port = vlan->port;
        int err;

        if (!(dev->flags & IFF_UP)) {
                /* Just copy in the new address */
                eth_hw_addr_set(dev, addr);
        } else {
                /* Rehash and update the device filters */
                if (macvlan_addr_busy(vlan->port, addr))
                        return -EADDRINUSE;

                if (!macvlan_passthru(port)) {
                        err = dev_uc_add(lowerdev, addr);
                        if (err)
                                return err;

                        dev_uc_del(lowerdev, dev->dev_addr);
                }

                macvlan_hash_change_addr(vlan, addr);
        }
        if (macvlan_passthru(port) && !macvlan_addr_change(port)) {
                /* Since addr_change isn't set, we are here due to lower
                 * device change.  Save the lower-dev address so we can
                 * restore it later.
                 */
                ether_addr_copy(vlan->port->perm_addr,
                                lowerdev->dev_addr);
        }
        macvlan_clear_addr_change(port);
        return 0;
}

static int macvlan_set_mac_address(struct net_device *dev, void *p)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct sockaddr_storage *addr = p;

        if (!is_valid_ether_addr(addr->__data))
                return -EADDRNOTAVAIL;

        /* If the addresses are the same, this is a no-op */
        if (ether_addr_equal(dev->dev_addr, addr->__data))
                return 0;

        if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
                macvlan_set_addr_change(vlan->port);
                return dev_set_mac_address(vlan->lowerdev, addr, NULL);
        }

        if (macvlan_addr_busy(vlan->port, addr->__data))
                return -EADDRINUSE;

        return macvlan_sync_address(dev, addr->__data);
}

static void macvlan_change_rx_flags(struct net_device *dev, int change)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;

        if (dev->flags & IFF_UP) {
                if (change & IFF_ALLMULTI)
                        dev_set_allmulti(lowerdev, dev->flags & IFF_ALLMULTI ? 1 : -1);
                if (!macvlan_passthru(vlan->port) && change & IFF_PROMISC)
                        dev_set_promiscuity(lowerdev,
                                            dev->flags & IFF_PROMISC ? 1 : -1);

        }
}

static void macvlan_compute_filter(unsigned long *mc_filter,
                                   struct net_device *dev,
                                   struct macvlan_dev *vlan, int cutoff)
{
        if (dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) {
                bitmap_fill(mc_filter, MACVLAN_MC_FILTER_SZ);
        } else {
                DECLARE_BITMAP(filter, MACVLAN_MC_FILTER_SZ);
                struct netdev_hw_addr *ha;

                bitmap_zero(filter, MACVLAN_MC_FILTER_SZ);
                netdev_for_each_mc_addr(ha, dev) {
                        if (!vlan && ha->synced <= cutoff)
                                continue;

                        __set_bit(mc_hash(vlan, ha->addr), filter);
                }

                __set_bit(mc_hash(vlan, dev->broadcast), filter);

                bitmap_copy(mc_filter, filter, MACVLAN_MC_FILTER_SZ);
        }
}

static void macvlan_recompute_bc_filter(struct macvlan_dev *vlan)
{
        if (vlan->port->bc_cutoff < 0) {
                bitmap_zero(vlan->port->bc_filter, MACVLAN_MC_FILTER_SZ);
                return;
        }

        macvlan_compute_filter(vlan->port->bc_filter, vlan->lowerdev, NULL,
                               vlan->port->bc_cutoff);
}

static void macvlan_set_mac_lists(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        macvlan_compute_filter(vlan->mc_filter, dev, vlan, 0);

        dev_uc_sync(vlan->lowerdev, dev);
        dev_mc_sync(vlan->lowerdev, dev);

        /* This is slightly inaccurate as we're including the subscription
         * list of vlan->lowerdev too.
         *
         * Bug alert: This only works if everyone has the same broadcast
         * address as lowerdev.  As soon as someone changes theirs this
         * will break.
         *
         * However, this is already broken as when you change your broadcast
         * address we don't get called.
         *
         * The solution is to maintain a list of broadcast addresses like
         * we do for uc/mc, if you care.
         */
        macvlan_compute_filter(vlan->port->mc_filter, vlan->lowerdev, NULL,
                               0);
        macvlan_recompute_bc_filter(vlan);
}

static void update_port_bc_cutoff(struct macvlan_dev *vlan, int cutoff)
{
        if (vlan->port->bc_cutoff == cutoff)
                return;

        vlan->port->bc_cutoff = cutoff;
        macvlan_recompute_bc_filter(vlan);
}

static int macvlan_change_mtu(struct net_device *dev, int new_mtu)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        if (vlan->lowerdev->mtu < new_mtu)
                return -EINVAL;
        WRITE_ONCE(dev->mtu, new_mtu);
        return 0;
}

static int macvlan_hwtstamp_get(struct net_device *dev,
                                struct kernel_hwtstamp_config *cfg)
{
        struct net_device *real_dev = macvlan_dev_real_dev(dev);

        return generic_hwtstamp_get_lower(real_dev, cfg);
}

static int macvlan_hwtstamp_set(struct net_device *dev,
                                struct kernel_hwtstamp_config *cfg,
                                struct netlink_ext_ack *extack)
{
        struct net_device *real_dev = macvlan_dev_real_dev(dev);

        if (!net_eq(dev_net(dev), &init_net))
                return -EOPNOTSUPP;

        return generic_hwtstamp_set_lower(real_dev, cfg, extack);
}

/*
 * macvlan network devices have devices nesting below it and are a special
 * "super class" of normal network devices; split their locks off into a
 * separate class since they always nest.
 */
static struct lock_class_key macvlan_netdev_addr_lock_key;

#define ALWAYS_ON_OFFLOADS \
        (NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_GSO_SOFTWARE | \
         NETIF_F_GSO_ROBUST | NETIF_F_GSO_ENCAP_ALL)

#define ALWAYS_ON_FEATURES ALWAYS_ON_OFFLOADS

#define MACVLAN_FEATURES \
        (NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
         NETIF_F_GSO | NETIF_F_TSO | NETIF_F_LRO | \
         NETIF_F_TSO_ECN | NETIF_F_TSO6 | NETIF_F_GRO | NETIF_F_RXCSUM | \
         NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_VLAN_STAG_FILTER)

#define MACVLAN_STATE_MASK \
        ((1<<__LINK_STATE_NOCARRIER) | (1<<__LINK_STATE_DORMANT))

static void macvlan_set_lockdep_class(struct net_device *dev)
{
        netdev_lockdep_set_classes(dev);
        lockdep_set_class(&dev->addr_list_lock,
                          &macvlan_netdev_addr_lock_key);
}

static int macvlan_init(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;
        struct macvlan_port *port = vlan->port;

        dev->state              = (dev->state & ~MACVLAN_STATE_MASK) |
                                  (lowerdev->state & MACVLAN_STATE_MASK);
        dev->features           = lowerdev->features & MACVLAN_FEATURES;
        dev->features           |= ALWAYS_ON_FEATURES;
        dev->hw_features        |= NETIF_F_LRO;
        dev->vlan_features      = lowerdev->vlan_features & MACVLAN_FEATURES;
        dev->vlan_features      |= ALWAYS_ON_OFFLOADS;
        dev->hw_enc_features    |= dev->features;
        dev->lltx               = true;
        netif_inherit_tso_max(dev, lowerdev);
        dev->hard_header_len    = lowerdev->hard_header_len;
        macvlan_set_lockdep_class(dev);

        vlan->pcpu_stats = netdev_alloc_pcpu_stats(struct vlan_pcpu_stats);
        if (!vlan->pcpu_stats)
                return -ENOMEM;

        port->count += 1;

        /* Get macvlan's reference to lowerdev */
        netdev_hold(lowerdev, &vlan->dev_tracker, GFP_KERNEL);

        return 0;
}

static void macvlan_uninit(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct macvlan_port *port = vlan->port;

        free_percpu(vlan->pcpu_stats);

        macvlan_flush_sources(port, vlan);
        port->count -= 1;
        if (!port->count)
                macvlan_port_destroy(port->dev);
}

static void macvlan_dev_get_stats64(struct net_device *dev,
                                    struct rtnl_link_stats64 *stats)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        if (vlan->pcpu_stats) {
                struct vlan_pcpu_stats *p;
                u64 rx_packets, rx_bytes, rx_multicast, tx_packets, tx_bytes;
                u32 rx_errors = 0, tx_dropped = 0;
                unsigned int start;
                int i;

                for_each_possible_cpu(i) {
                        p = per_cpu_ptr(vlan->pcpu_stats, i);
                        do {
                                start = u64_stats_fetch_begin(&p->syncp);
                                rx_packets      = u64_stats_read(&p->rx_packets);
                                rx_bytes        = u64_stats_read(&p->rx_bytes);
                                rx_multicast    = u64_stats_read(&p->rx_multicast);
                                tx_packets      = u64_stats_read(&p->tx_packets);
                                tx_bytes        = u64_stats_read(&p->tx_bytes);
                        } while (u64_stats_fetch_retry(&p->syncp, start));

                        stats->rx_packets       += rx_packets;
                        stats->rx_bytes         += rx_bytes;
                        stats->multicast        += rx_multicast;
                        stats->tx_packets       += tx_packets;
                        stats->tx_bytes         += tx_bytes;
                        /* rx_errors & tx_dropped are u32, updated
                         * without syncp protection.
                         */
                        rx_errors       += READ_ONCE(p->rx_errors);
                        tx_dropped      += READ_ONCE(p->tx_dropped);
                }
                stats->rx_errors        = rx_errors;
                stats->rx_dropped       = rx_errors;
                stats->tx_dropped       = tx_dropped;
        }
}

static int macvlan_vlan_rx_add_vid(struct net_device *dev,
                                   __be16 proto, u16 vid)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;

        return vlan_vid_add(lowerdev, proto, vid);
}

static int macvlan_vlan_rx_kill_vid(struct net_device *dev,
                                    __be16 proto, u16 vid)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *lowerdev = vlan->lowerdev;

        vlan_vid_del(lowerdev, proto, vid);
        return 0;
}

static int macvlan_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
                           struct net_device *dev,
                           const unsigned char *addr, u16 vid,
                           u16 flags, bool *notified,
                           struct netlink_ext_ack *extack)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        int err = -EINVAL;

        /* Support unicast filter only on passthru devices.
         * Multicast filter should be allowed on all devices.
         */
        if (!macvlan_passthru(vlan->port) && is_unicast_ether_addr(addr))
                return -EOPNOTSUPP;

        if (flags & NLM_F_REPLACE)
                return -EOPNOTSUPP;

        if (is_unicast_ether_addr(addr))
                err = dev_uc_add_excl(dev, addr);
        else if (is_multicast_ether_addr(addr))
                err = dev_mc_add_excl(dev, addr);

        return err;
}

static int macvlan_fdb_del(struct ndmsg *ndm, struct nlattr *tb[],
                           struct net_device *dev,
                           const unsigned char *addr, u16 vid, bool *notified,
                           struct netlink_ext_ack *extack)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        int err = -EINVAL;

        /* Support unicast filter only on passthru devices.
         * Multicast filter should be allowed on all devices.
         */
        if (!macvlan_passthru(vlan->port) && is_unicast_ether_addr(addr))
                return -EOPNOTSUPP;

        if (is_unicast_ether_addr(addr))
                err = dev_uc_del(dev, addr);
        else if (is_multicast_ether_addr(addr))
                err = dev_mc_del(dev, addr);

        return err;
}

static void macvlan_ethtool_get_drvinfo(struct net_device *dev,
                                        struct ethtool_drvinfo *drvinfo)
{
        strscpy(drvinfo->driver, "macvlan", sizeof(drvinfo->driver));
        strscpy(drvinfo->version, "0.1", sizeof(drvinfo->version));
}

static int macvlan_ethtool_get_link_ksettings(struct net_device *dev,
                                              struct ethtool_link_ksettings *cmd)
{
        const struct macvlan_dev *vlan = netdev_priv(dev);

        return __ethtool_get_link_ksettings(vlan->lowerdev, cmd);
}

static int macvlan_ethtool_get_ts_info(struct net_device *dev,
                                       struct kernel_ethtool_ts_info *info)
{
        struct net_device *real_dev = macvlan_dev_real_dev(dev);

        return ethtool_get_ts_info_by_layer(real_dev, info);
}

static netdev_features_t macvlan_fix_features(struct net_device *dev,
                                              netdev_features_t features)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        netdev_features_t lowerdev_features = vlan->lowerdev->features;
        netdev_features_t mask;

        features |= NETIF_F_ALL_FOR_ALL;
        features &= (vlan->set_features | ~MACVLAN_FEATURES);
        mask = features;

        lowerdev_features &= (features | ~NETIF_F_LRO);
        features = netdev_increment_features(lowerdev_features, features, mask);
        features |= ALWAYS_ON_FEATURES;
        features &= (ALWAYS_ON_FEATURES | MACVLAN_FEATURES);

        return features;
}

#ifdef CONFIG_NET_POLL_CONTROLLER
static void macvlan_dev_poll_controller(struct net_device *dev)
{
        return;
}

static int macvlan_dev_netpoll_setup(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct net_device *real_dev = vlan->lowerdev;
        struct netpoll *netpoll;
        int err;

        netpoll = kzalloc_obj(*netpoll);
        err = -ENOMEM;
        if (!netpoll)
                goto out;

        err = __netpoll_setup(netpoll, real_dev);
        if (err) {
                kfree(netpoll);
                goto out;
        }

        vlan->netpoll = netpoll;

out:
        return err;
}

static void macvlan_dev_netpoll_cleanup(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct netpoll *netpoll = vlan->netpoll;

        if (!netpoll)
                return;

        vlan->netpoll = NULL;

        __netpoll_free(netpoll);
}
#endif  /* CONFIG_NET_POLL_CONTROLLER */

static int macvlan_dev_get_iflink(const struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        return READ_ONCE(vlan->lowerdev->ifindex);
}

static const struct ethtool_ops macvlan_ethtool_ops = {
        .get_link               = ethtool_op_get_link,
        .get_link_ksettings     = macvlan_ethtool_get_link_ksettings,
        .get_drvinfo            = macvlan_ethtool_get_drvinfo,
        .get_ts_info            = macvlan_ethtool_get_ts_info,
};

static const struct net_device_ops macvlan_netdev_ops = {
        .ndo_init               = macvlan_init,
        .ndo_uninit             = macvlan_uninit,
        .ndo_open               = macvlan_open,
        .ndo_stop               = macvlan_stop,
        .ndo_start_xmit         = macvlan_start_xmit,
        .ndo_change_mtu         = macvlan_change_mtu,
        .ndo_fix_features       = macvlan_fix_features,
        .ndo_change_rx_flags    = macvlan_change_rx_flags,
        .ndo_set_mac_address    = macvlan_set_mac_address,
        .ndo_set_rx_mode        = macvlan_set_mac_lists,
        .ndo_get_stats64        = macvlan_dev_get_stats64,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_vlan_rx_add_vid    = macvlan_vlan_rx_add_vid,
        .ndo_vlan_rx_kill_vid   = macvlan_vlan_rx_kill_vid,
        .ndo_fdb_add            = macvlan_fdb_add,
        .ndo_fdb_del            = macvlan_fdb_del,
        .ndo_fdb_dump           = ndo_dflt_fdb_dump,
#ifdef CONFIG_NET_POLL_CONTROLLER
        .ndo_poll_controller    = macvlan_dev_poll_controller,
        .ndo_netpoll_setup      = macvlan_dev_netpoll_setup,
        .ndo_netpoll_cleanup    = macvlan_dev_netpoll_cleanup,
#endif
        .ndo_get_iflink         = macvlan_dev_get_iflink,
        .ndo_features_check     = passthru_features_check,
        .ndo_hwtstamp_get       = macvlan_hwtstamp_get,
        .ndo_hwtstamp_set       = macvlan_hwtstamp_set,
};

static void macvlan_dev_free(struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        /* Get rid of the macvlan's reference to lowerdev */
        netdev_put(vlan->lowerdev, &vlan->dev_tracker);
}

void macvlan_common_setup(struct net_device *dev)
{
        ether_setup(dev);

        /* ether_setup() has set dev->min_mtu to ETH_MIN_MTU. */
        dev->max_mtu            = ETH_MAX_MTU;
        dev->priv_flags        &= ~IFF_TX_SKB_SHARING;
        netif_keep_dst(dev);
        dev->priv_flags        |= IFF_UNICAST_FLT;
        dev->change_proto_down  = true;
        dev->netdev_ops         = &macvlan_netdev_ops;
        dev->needs_free_netdev  = true;
        dev->priv_destructor    = macvlan_dev_free;
        dev->header_ops         = &macvlan_hard_header_ops;
        dev->ethtool_ops        = &macvlan_ethtool_ops;
}
EXPORT_SYMBOL_GPL(macvlan_common_setup);

static void macvlan_setup(struct net_device *dev)
{
        macvlan_common_setup(dev);
        dev->priv_flags |= IFF_NO_QUEUE;
}

static int macvlan_port_create(struct net_device *dev)
{
        struct macvlan_port *port;
        unsigned int i;
        int err;

        if (dev->type != ARPHRD_ETHER || dev->flags & IFF_LOOPBACK)
                return -EINVAL;

        if (netdev_is_rx_handler_busy(dev))
                return -EBUSY;

        port = kzalloc_obj(*port);
        if (port == NULL)
                return -ENOMEM;

        port->dev = dev;
        ether_addr_copy(port->perm_addr, dev->dev_addr);
        INIT_LIST_HEAD(&port->vlans);
        for (i = 0; i < MACVLAN_HASH_SIZE; i++)
                INIT_HLIST_HEAD(&port->vlan_hash[i]);
        for (i = 0; i < MACVLAN_HASH_SIZE; i++)
                INIT_HLIST_HEAD(&port->vlan_source_hash[i]);

        port->bc_queue_len_used = 0;
        port->bc_cutoff = 1;
        skb_queue_head_init(&port->bc_queue);
        INIT_WORK(&port->bc_work, macvlan_process_broadcast);

        err = netdev_rx_handler_register(dev, macvlan_handle_frame, port);
        if (err)
                kfree(port);
        else
                dev->priv_flags |= IFF_MACVLAN_PORT;
        return err;
}

static void macvlan_port_destroy(struct net_device *dev)
{
        struct macvlan_port *port = macvlan_port_get_rtnl(dev);
        struct sk_buff *skb;

        dev->priv_flags &= ~IFF_MACVLAN_PORT;
        netdev_rx_handler_unregister(dev);

        /* After this point, no packet can schedule bc_work anymore,
         * but we need to cancel it and purge left skbs if any.
         */
        cancel_work_sync(&port->bc_work);

        while ((skb = __skb_dequeue(&port->bc_queue))) {
                const struct macvlan_dev *src = MACVLAN_SKB_CB(skb)->src;

                if (src)
                        dev_put(src->dev);

                kfree_skb(skb);
        }

        /* If the lower device address has been changed by passthru
         * macvlan, put it back.
         */
        if (macvlan_passthru(port) &&
            !ether_addr_equal(port->dev->dev_addr, port->perm_addr)) {
                struct sockaddr_storage ss;

                ss.ss_family = port->dev->type;
                memcpy(&ss.__data, port->perm_addr, port->dev->addr_len);
                dev_set_mac_address(port->dev, &ss, NULL);
        }

        kfree(port);
}

static int macvlan_validate(struct nlattr *tb[], struct nlattr *data[],
                            struct netlink_ext_ack *extack)
{
        struct nlattr *nla, *head;
        int rem, len;

        if (tb[IFLA_ADDRESS]) {
                if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
                        return -EINVAL;
                if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
                        return -EADDRNOTAVAIL;
        }

        if (!data)
                return 0;

        if (data[IFLA_MACVLAN_FLAGS] &&
            nla_get_u16(data[IFLA_MACVLAN_FLAGS]) & ~(MACVLAN_FLAG_NOPROMISC |
                                                      MACVLAN_FLAG_NODST))
                return -EINVAL;

        if (data[IFLA_MACVLAN_MODE]) {
                switch (nla_get_u32(data[IFLA_MACVLAN_MODE])) {
                case MACVLAN_MODE_PRIVATE:
                case MACVLAN_MODE_VEPA:
                case MACVLAN_MODE_BRIDGE:
                case MACVLAN_MODE_PASSTHRU:
                case MACVLAN_MODE_SOURCE:
                        break;
                default:
                        return -EINVAL;
                }
        }

        if (data[IFLA_MACVLAN_MACADDR_MODE]) {
                switch (nla_get_u32(data[IFLA_MACVLAN_MACADDR_MODE])) {
                case MACVLAN_MACADDR_ADD:
                case MACVLAN_MACADDR_DEL:
                case MACVLAN_MACADDR_FLUSH:
                case MACVLAN_MACADDR_SET:
                        break;
                default:
                        return -EINVAL;
                }
        }

        if (data[IFLA_MACVLAN_MACADDR]) {
                if (nla_len(data[IFLA_MACVLAN_MACADDR]) != ETH_ALEN)
                        return -EINVAL;

                if (!is_valid_ether_addr(nla_data(data[IFLA_MACVLAN_MACADDR])))
                        return -EADDRNOTAVAIL;
        }

        if (data[IFLA_MACVLAN_MACADDR_DATA]) {
                head = nla_data(data[IFLA_MACVLAN_MACADDR_DATA]);
                len = nla_len(data[IFLA_MACVLAN_MACADDR_DATA]);

                nla_for_each_attr(nla, head, len, rem) {
                        if (nla_type(nla) != IFLA_MACVLAN_MACADDR ||
                            nla_len(nla) != ETH_ALEN)
                                return -EINVAL;

                        if (!is_valid_ether_addr(nla_data(nla)))
                                return -EADDRNOTAVAIL;
                }
        }

        if (data[IFLA_MACVLAN_MACADDR_COUNT])
                return -EINVAL;

        return 0;
}

/*
 * reconfigure list of remote source mac address
 * (only for macvlan devices in source mode)
 * Note regarding alignment: all netlink data is aligned to 4 Byte, which
 * suffices for both ether_addr_copy and ether_addr_equal_64bits usage.
 */
static int macvlan_changelink_sources(struct macvlan_dev *vlan, u32 mode,
                                      struct nlattr *data[])
{
        char *addr = NULL;
        int ret, rem, len;
        struct nlattr *nla, *head;
        struct macvlan_source_entry *entry;

        if (data[IFLA_MACVLAN_MACADDR])
                addr = nla_data(data[IFLA_MACVLAN_MACADDR]);

        if (mode == MACVLAN_MACADDR_ADD) {
                if (!addr)
                        return -EINVAL;

                return macvlan_hash_add_source(vlan, addr);

        } else if (mode == MACVLAN_MACADDR_DEL) {
                if (!addr)
                        return -EINVAL;

                entry = macvlan_hash_lookup_source(vlan, addr);
                if (entry) {
                        macvlan_hash_del_source(entry);
                        vlan->macaddr_count--;
                }
        } else if (mode == MACVLAN_MACADDR_FLUSH) {
                macvlan_flush_sources(vlan->port, vlan);
        } else if (mode == MACVLAN_MACADDR_SET) {
                macvlan_flush_sources(vlan->port, vlan);

                if (addr) {
                        ret = macvlan_hash_add_source(vlan, addr);
                        if (ret)
                                return ret;
                }

                if (!data[IFLA_MACVLAN_MACADDR_DATA])
                        return 0;

                head = nla_data(data[IFLA_MACVLAN_MACADDR_DATA]);
                len = nla_len(data[IFLA_MACVLAN_MACADDR_DATA]);

                nla_for_each_attr(nla, head, len, rem) {
                        addr = nla_data(nla);
                        ret = macvlan_hash_add_source(vlan, addr);
                        if (ret)
                                return ret;
                }
        } else {
                return -EINVAL;
        }

        return 0;
}

int macvlan_common_newlink(struct net_device *dev,
                           struct rtnl_newlink_params *params,
                           struct netlink_ext_ack *extack)
{
        struct net *link_net = rtnl_newlink_link_net(params);
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct nlattr **data = params->data;
        struct nlattr **tb = params->tb;
        struct net_device *lowerdev;
        struct macvlan_port *port;
        bool create = false;
        int macmode;
        int err;

        if (!tb[IFLA_LINK])
                return -EINVAL;

        lowerdev = __dev_get_by_index(link_net, nla_get_u32(tb[IFLA_LINK]));
        if (lowerdev == NULL)
                return -ENODEV;

        /* When creating macvlans or macvtaps on top of other macvlans - use
         * the real device as the lowerdev.
         */
        if (netif_is_macvlan(lowerdev))
                lowerdev = macvlan_dev_real_dev(lowerdev);

        if (!tb[IFLA_MTU])
                dev->mtu = lowerdev->mtu;
        else if (dev->mtu > lowerdev->mtu)
                return -EINVAL;

        /* MTU range: 68 - lowerdev->max_mtu */
        dev->min_mtu = ETH_MIN_MTU;
        dev->max_mtu = lowerdev->max_mtu;

        if (!tb[IFLA_ADDRESS])
                eth_hw_addr_random(dev);

        if (!netif_is_macvlan_port(lowerdev)) {
                err = macvlan_port_create(lowerdev);
                if (err < 0)
                        return err;
                create = true;
        }
        port = macvlan_port_get_rtnl(lowerdev);

        /* Only 1 macvlan device can be created in passthru mode */
        if (macvlan_passthru(port)) {
                /* The macvlan port must be not created this time,
                 * still goto destroy_macvlan_port for readability.
                 */
                err = -EINVAL;
                goto destroy_macvlan_port;
        }

        vlan->lowerdev = lowerdev;
        vlan->dev      = dev;
        vlan->port     = port;
        vlan->set_features = MACVLAN_FEATURES;

        vlan->mode     = MACVLAN_MODE_VEPA;
        if (data && data[IFLA_MACVLAN_MODE])
                vlan->mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);

        if (data && data[IFLA_MACVLAN_FLAGS])
                vlan->flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]);

        if (vlan->mode == MACVLAN_MODE_PASSTHRU) {
                if (port->count) {
                        err = -EINVAL;
                        goto destroy_macvlan_port;
                }
                macvlan_set_passthru(port);
                eth_hw_addr_inherit(dev, lowerdev);
        }

        if (data && data[IFLA_MACVLAN_MACADDR_MODE]) {
                if (vlan->mode != MACVLAN_MODE_SOURCE) {
                        err = -EINVAL;
                        goto destroy_macvlan_port;
                }
                macmode = nla_get_u32(data[IFLA_MACVLAN_MACADDR_MODE]);
                err = macvlan_changelink_sources(vlan, macmode, data);
                if (err)
                        goto destroy_macvlan_port;
        }

        vlan->bc_queue_len_req = MACVLAN_DEFAULT_BC_QUEUE_LEN;
        if (data && data[IFLA_MACVLAN_BC_QUEUE_LEN])
                vlan->bc_queue_len_req = nla_get_u32(data[IFLA_MACVLAN_BC_QUEUE_LEN]);

        if (data && data[IFLA_MACVLAN_BC_CUTOFF])
                update_port_bc_cutoff(
                        vlan, nla_get_s32(data[IFLA_MACVLAN_BC_CUTOFF]));

        err = register_netdevice(dev);
        if (err < 0)
                goto destroy_macvlan_port;

        dev->priv_flags |= IFF_MACVLAN;
        err = netdev_upper_dev_link(lowerdev, dev, extack);
        if (err)
                goto unregister_netdev;

        list_add_tail_rcu(&vlan->list, &port->vlans);
        update_port_bc_queue_len(vlan->port);
        netif_stacked_transfer_operstate(lowerdev, dev);
        linkwatch_fire_event(dev);

        return 0;

unregister_netdev:
        /* macvlan_uninit would free the macvlan port */
        unregister_netdevice(dev);
        return err;
destroy_macvlan_port:
        /* the macvlan port may be freed by macvlan_uninit when fail to register.
         * so we destroy the macvlan port only when it's valid.
         */
        if (macvlan_port_get_rtnl(lowerdev)) {
                macvlan_flush_sources(port, vlan);
                if (create)
                        macvlan_port_destroy(port->dev);
        }
        /* @dev might have been made visible before an error was detected.
         * Make sure to observe an RCU grace period before our caller
         * (rtnl_newlink()) frees it.
         */
        synchronize_net();
        return err;
}
EXPORT_SYMBOL_GPL(macvlan_common_newlink);

static int macvlan_newlink(struct net_device *dev,
                           struct rtnl_newlink_params *params,
                           struct netlink_ext_ack *extack)
{
        return macvlan_common_newlink(dev, params, extack);
}

void macvlan_dellink(struct net_device *dev, struct list_head *head)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        if (vlan->mode == MACVLAN_MODE_SOURCE)
                macvlan_flush_sources(vlan->port, vlan);
        list_del_rcu(&vlan->list);
        update_port_bc_queue_len(vlan->port);
        unregister_netdevice_queue(dev, head);
        netdev_upper_dev_unlink(vlan->lowerdev, dev);
}
EXPORT_SYMBOL_GPL(macvlan_dellink);

static int macvlan_changelink(struct net_device *dev,
                              struct nlattr *tb[], struct nlattr *data[],
                              struct netlink_ext_ack *extack)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        enum macvlan_mode mode;
        bool set_mode = false;
        enum macvlan_macaddr_mode macmode;
        int ret;

        /* Validate mode, but don't set yet: setting flags may fail. */
        if (data && data[IFLA_MACVLAN_MODE]) {
                set_mode = true;
                mode = nla_get_u32(data[IFLA_MACVLAN_MODE]);
                /* Passthrough mode can't be set or cleared dynamically */
                if ((mode == MACVLAN_MODE_PASSTHRU) !=
                    (vlan->mode == MACVLAN_MODE_PASSTHRU))
                        return -EINVAL;
                if (vlan->mode == MACVLAN_MODE_SOURCE &&
                    vlan->mode != mode)
                        macvlan_flush_sources(vlan->port, vlan);
        }

        if (data && data[IFLA_MACVLAN_FLAGS]) {
                __u16 flags = nla_get_u16(data[IFLA_MACVLAN_FLAGS]);
                bool promisc = (flags ^ vlan->flags) & MACVLAN_FLAG_NOPROMISC;
                if (macvlan_passthru(vlan->port) && promisc) {
                        int err;

                        if (flags & MACVLAN_FLAG_NOPROMISC)
                                err = dev_set_promiscuity(vlan->lowerdev, -1);
                        else
                                err = dev_set_promiscuity(vlan->lowerdev, 1);
                        if (err < 0)
                                return err;
                }
                vlan->flags = flags;
        }

        if (data && data[IFLA_MACVLAN_BC_QUEUE_LEN]) {
                vlan->bc_queue_len_req = nla_get_u32(data[IFLA_MACVLAN_BC_QUEUE_LEN]);
                update_port_bc_queue_len(vlan->port);
        }

        if (data && data[IFLA_MACVLAN_BC_CUTOFF])
                update_port_bc_cutoff(
                        vlan, nla_get_s32(data[IFLA_MACVLAN_BC_CUTOFF]));

        if (set_mode)
                vlan->mode = mode;
        if (data && data[IFLA_MACVLAN_MACADDR_MODE]) {
                if (vlan->mode != MACVLAN_MODE_SOURCE)
                        return -EINVAL;
                macmode = nla_get_u32(data[IFLA_MACVLAN_MACADDR_MODE]);
                ret = macvlan_changelink_sources(vlan, macmode, data);
                if (ret)
                        return ret;
        }
        return 0;
}

static size_t macvlan_get_size_mac(const struct macvlan_dev *vlan)
{
        if (vlan->macaddr_count == 0)
                return 0;
        return nla_total_size(0) /* IFLA_MACVLAN_MACADDR_DATA */
                + vlan->macaddr_count * nla_total_size(sizeof(u8) * ETH_ALEN);
}

static size_t macvlan_get_size(const struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);

        return (0
                + nla_total_size(4) /* IFLA_MACVLAN_MODE */
                + nla_total_size(2) /* IFLA_MACVLAN_FLAGS */
                + nla_total_size(4) /* IFLA_MACVLAN_MACADDR_COUNT */
                + macvlan_get_size_mac(vlan) /* IFLA_MACVLAN_MACADDR */
                + nla_total_size(4) /* IFLA_MACVLAN_BC_QUEUE_LEN */
                + nla_total_size(4) /* IFLA_MACVLAN_BC_QUEUE_LEN_USED */
                );
}

static int macvlan_fill_info_macaddr(struct sk_buff *skb,
                                     const struct macvlan_dev *vlan,
                                     const int i)
{
        struct hlist_head *h = &vlan->port->vlan_source_hash[i];
        struct macvlan_source_entry *entry;

        hlist_for_each_entry_rcu(entry, h, hlist, lockdep_rtnl_is_held()) {
                if (rcu_access_pointer(entry->vlan) != vlan)
                        continue;
                if (nla_put(skb, IFLA_MACVLAN_MACADDR, ETH_ALEN, entry->addr))
                        return 1;
        }
        return 0;
}

static int macvlan_fill_info(struct sk_buff *skb,
                                const struct net_device *dev)
{
        struct macvlan_dev *vlan = netdev_priv(dev);
        struct macvlan_port *port = vlan->port;
        int i;
        struct nlattr *nest;

        if (nla_put_u32(skb, IFLA_MACVLAN_MODE, vlan->mode))
                goto nla_put_failure;
        if (nla_put_u16(skb, IFLA_MACVLAN_FLAGS, vlan->flags))
                goto nla_put_failure;
        if (nla_put_u32(skb, IFLA_MACVLAN_MACADDR_COUNT, vlan->macaddr_count))
                goto nla_put_failure;
        if (vlan->macaddr_count > 0) {
                nest = nla_nest_start_noflag(skb, IFLA_MACVLAN_MACADDR_DATA);
                if (nest == NULL)
                        goto nla_put_failure;

                for (i = 0; i < MACVLAN_HASH_SIZE; i++) {
                        if (macvlan_fill_info_macaddr(skb, vlan, i))
                                goto nla_put_failure;
                }
                nla_nest_end(skb, nest);
        }
        if (nla_put_u32(skb, IFLA_MACVLAN_BC_QUEUE_LEN, vlan->bc_queue_len_req))
                goto nla_put_failure;
        if (nla_put_u32(skb, IFLA_MACVLAN_BC_QUEUE_LEN_USED, port->bc_queue_len_used))
                goto nla_put_failure;
        if (port->bc_cutoff != 1 &&
            nla_put_s32(skb, IFLA_MACVLAN_BC_CUTOFF, port->bc_cutoff))
                goto nla_put_failure;
        return 0;

nla_put_failure:
        return -EMSGSIZE;
}

static const struct nla_policy macvlan_policy[IFLA_MACVLAN_MAX + 1] = {
        [IFLA_MACVLAN_MODE]  = { .type = NLA_U32 },
        [IFLA_MACVLAN_FLAGS] = { .type = NLA_U16 },
        [IFLA_MACVLAN_MACADDR_MODE] = { .type = NLA_U32 },
        [IFLA_MACVLAN_MACADDR] = { .type = NLA_BINARY, .len = MAX_ADDR_LEN },
        [IFLA_MACVLAN_MACADDR_DATA] = { .type = NLA_NESTED },
        [IFLA_MACVLAN_MACADDR_COUNT] = { .type = NLA_U32 },
        [IFLA_MACVLAN_BC_QUEUE_LEN] = { .type = NLA_U32 },
        [IFLA_MACVLAN_BC_QUEUE_LEN_USED] = { .type = NLA_REJECT },
        [IFLA_MACVLAN_BC_CUTOFF] = { .type = NLA_S32 },
};

int macvlan_link_register(struct rtnl_link_ops *ops)
{
        /* common fields */
        ops->validate           = macvlan_validate;
        ops->maxtype            = IFLA_MACVLAN_MAX;
        ops->policy             = macvlan_policy;
        ops->changelink         = macvlan_changelink;
        ops->get_size           = macvlan_get_size;
        ops->fill_info          = macvlan_fill_info;

        return rtnl_link_register(ops);
};
EXPORT_SYMBOL_GPL(macvlan_link_register);

static struct net *macvlan_get_link_net(const struct net_device *dev)
{
        return dev_net(macvlan_dev_real_dev(dev));
}

static struct rtnl_link_ops macvlan_link_ops = {
        .kind           = "macvlan",
        .setup          = macvlan_setup,
        .newlink        = macvlan_newlink,
        .dellink        = macvlan_dellink,
        .get_link_net   = macvlan_get_link_net,
        .priv_size      = sizeof(struct macvlan_dev),
};

static void update_port_bc_queue_len(struct macvlan_port *port)
{
        u32 max_bc_queue_len_req = 0;
        struct macvlan_dev *vlan;

        list_for_each_entry(vlan, &port->vlans, list) {
                if (vlan->bc_queue_len_req > max_bc_queue_len_req)
                        max_bc_queue_len_req = vlan->bc_queue_len_req;
        }
        port->bc_queue_len_used = max_bc_queue_len_req;
}

static int macvlan_device_event(struct notifier_block *unused,
                                unsigned long event, void *ptr)
{
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
        struct macvlan_dev *vlan, *next;
        struct macvlan_port *port;
        LIST_HEAD(list_kill);

        if (!netif_is_macvlan_port(dev))
                return NOTIFY_DONE;

        port = macvlan_port_get_rtnl(dev);

        switch (event) {
        case NETDEV_UP:
        case NETDEV_DOWN:
        case NETDEV_CHANGE:
                list_for_each_entry(vlan, &port->vlans, list)
                        netif_stacked_transfer_operstate(vlan->lowerdev,
                                                         vlan->dev);
                break;
        case NETDEV_FEAT_CHANGE:
                list_for_each_entry(vlan, &port->vlans, list) {
                        netif_inherit_tso_max(vlan->dev, dev);
                        netdev_update_features(vlan->dev);
                }
                break;
        case NETDEV_CHANGEMTU:
                list_for_each_entry(vlan, &port->vlans, list) {
                        if (vlan->dev->mtu <= dev->mtu)
                                continue;
                        dev_set_mtu(vlan->dev, dev->mtu);
                }
                break;
        case NETDEV_CHANGEADDR:
                if (!macvlan_passthru(port))
                        return NOTIFY_DONE;

                vlan = list_first_entry_or_null(&port->vlans,
                                                struct macvlan_dev,
                                                list);

                if (vlan && macvlan_sync_address(vlan->dev, dev->dev_addr))
                        return NOTIFY_BAD;

                break;
        case NETDEV_UNREGISTER:
                /* twiddle thumbs on netns device moves */
                if (dev->reg_state != NETREG_UNREGISTERING)
                        break;

                list_for_each_entry_safe(vlan, next, &port->vlans, list)
                        vlan->dev->rtnl_link_ops->dellink(vlan->dev, &list_kill);
                unregister_netdevice_many(&list_kill);
                break;
        case NETDEV_PRE_TYPE_CHANGE:
                /* Forbid underlying device to change its type. */
                return NOTIFY_BAD;

        case NETDEV_NOTIFY_PEERS:
        case NETDEV_BONDING_FAILOVER:
        case NETDEV_RESEND_IGMP:
                /* Propagate to all vlans */
                list_for_each_entry(vlan, &port->vlans, list)
                        call_netdevice_notifiers(event, vlan->dev);
        }
        return NOTIFY_DONE;
}

static struct notifier_block macvlan_notifier_block __read_mostly = {
        .notifier_call  = macvlan_device_event,
};

static int __init macvlan_init_module(void)
{
        int err;

        register_netdevice_notifier(&macvlan_notifier_block);

        err = macvlan_link_register(&macvlan_link_ops);
        if (err < 0)
                goto err1;
        return 0;
err1:
        unregister_netdevice_notifier(&macvlan_notifier_block);
        return err;
}

static void __exit macvlan_cleanup_module(void)
{
        rtnl_link_unregister(&macvlan_link_ops);
        unregister_netdevice_notifier(&macvlan_notifier_block);
}

module_init(macvlan_init_module);
module_exit(macvlan_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_DESCRIPTION("Driver for MAC address based VLANs");
MODULE_ALIAS_RTNL_LINK("macvlan");