net/bridge/br_fdb.c

root/net/bridge/br_fdb.c
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *      Forwarding database
 *      Linux ethernet bridge
 *
 *      Authors:
 *      Lennert Buytenhek               <buytenh@gnu.org>
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/rculist.h>
#include <linux/spinlock.h>
#include <linux/times.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/jhash.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/atomic.h>
#include <linux/unaligned.h>
#include <linux/if_vlan.h>
#include <net/switchdev.h>
#include <trace/events/bridge.h>
#include "br_private.h"

static const struct rhashtable_params br_fdb_rht_params = {
        .head_offset = offsetof(struct net_bridge_fdb_entry, rhnode),
        .key_offset = offsetof(struct net_bridge_fdb_entry, key),
        .key_len = sizeof(struct net_bridge_fdb_key),
        .automatic_shrinking = true,
};

static struct kmem_cache *br_fdb_cache __read_mostly;

int __init br_fdb_init(void)
{
        br_fdb_cache = KMEM_CACHE(net_bridge_fdb_entry, SLAB_HWCACHE_ALIGN);
        if (!br_fdb_cache)
                return -ENOMEM;

        return 0;
}

void br_fdb_fini(void)
{
        kmem_cache_destroy(br_fdb_cache);
}

int br_fdb_hash_init(struct net_bridge *br)
{
        return rhashtable_init(&br->fdb_hash_tbl, &br_fdb_rht_params);
}

void br_fdb_hash_fini(struct net_bridge *br)
{
        rhashtable_destroy(&br->fdb_hash_tbl);
}

/* if topology_changing then use forward_delay (default 15 sec)
 * otherwise keep longer (default 5 minutes)
 */
static inline unsigned long hold_time(const struct net_bridge *br)
{
        return br->topology_change ? br->forward_delay : br->ageing_time;
}

static inline int has_expired(const struct net_bridge *br,
                                  const struct net_bridge_fdb_entry *fdb)
{
        return !test_bit(BR_FDB_STATIC, &fdb->flags) &&
               !test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags) &&
               time_before_eq(READ_ONCE(fdb->updated) + hold_time(br), jiffies);
}

static int fdb_to_nud(const struct net_bridge *br,
                      const struct net_bridge_fdb_entry *fdb)
{
        if (test_bit(BR_FDB_LOCAL, &fdb->flags))
                return NUD_PERMANENT;
        else if (test_bit(BR_FDB_STATIC, &fdb->flags))
                return NUD_NOARP;
        else if (has_expired(br, fdb))
                return NUD_STALE;
        else
                return NUD_REACHABLE;
}

static int fdb_fill_info(struct sk_buff *skb, const struct net_bridge *br,
                         const struct net_bridge_fdb_entry *fdb,
                         u32 portid, u32 seq, int type, unsigned int flags)
{
        const struct net_bridge_port *dst = READ_ONCE(fdb->dst);
        unsigned long now = jiffies;
        struct nda_cacheinfo ci;
        struct nlmsghdr *nlh;
        struct ndmsg *ndm;
        u32 ext_flags = 0;

        nlh = nlmsg_put(skb, portid, seq, type, sizeof(*ndm), flags);
        if (nlh == NULL)
                return -EMSGSIZE;

        ndm = nlmsg_data(nlh);
        ndm->ndm_family  = AF_BRIDGE;
        ndm->ndm_pad1    = 0;
        ndm->ndm_pad2    = 0;
        ndm->ndm_flags   = 0;
        ndm->ndm_type    = 0;
        ndm->ndm_ifindex = dst ? dst->dev->ifindex : br->dev->ifindex;
        ndm->ndm_state   = fdb_to_nud(br, fdb);

        if (test_bit(BR_FDB_OFFLOADED, &fdb->flags))
                ndm->ndm_flags |= NTF_OFFLOADED;
        if (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
                ndm->ndm_flags |= NTF_EXT_LEARNED;
        if (test_bit(BR_FDB_STICKY, &fdb->flags))
                ndm->ndm_flags |= NTF_STICKY;
        if (test_bit(BR_FDB_LOCKED, &fdb->flags))
                ext_flags |= NTF_EXT_LOCKED;

        if (nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->key.addr))
                goto nla_put_failure;
        if (nla_put_u32(skb, NDA_MASTER, br->dev->ifindex))
                goto nla_put_failure;
        if (nla_put_u32(skb, NDA_FLAGS_EXT, ext_flags))
                goto nla_put_failure;

        ci.ndm_used      = jiffies_to_clock_t(now - READ_ONCE(fdb->used));
        ci.ndm_confirmed = 0;
        ci.ndm_updated   = jiffies_to_clock_t(now - READ_ONCE(fdb->updated));
        ci.ndm_refcnt    = 0;
        if (nla_put(skb, NDA_CACHEINFO, sizeof(ci), &ci))
                goto nla_put_failure;

        if (fdb->key.vlan_id && nla_put(skb, NDA_VLAN, sizeof(u16),
                                        &fdb->key.vlan_id))
                goto nla_put_failure;

        if (test_bit(BR_FDB_NOTIFY, &fdb->flags)) {
                struct nlattr *nest = nla_nest_start(skb, NDA_FDB_EXT_ATTRS);
                u8 notify_bits = FDB_NOTIFY_BIT;

                if (!nest)
                        goto nla_put_failure;
                if (test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags))
                        notify_bits |= FDB_NOTIFY_INACTIVE_BIT;

                if (nla_put_u8(skb, NFEA_ACTIVITY_NOTIFY, notify_bits)) {
                        nla_nest_cancel(skb, nest);
                        goto nla_put_failure;
                }

                nla_nest_end(skb, nest);
        }

        nlmsg_end(skb, nlh);
        return 0;

nla_put_failure:
        nlmsg_cancel(skb, nlh);
        return -EMSGSIZE;
}

static inline size_t fdb_nlmsg_size(void)
{
        return NLMSG_ALIGN(sizeof(struct ndmsg))
                + nla_total_size(ETH_ALEN) /* NDA_LLADDR */
                + nla_total_size(sizeof(u32)) /* NDA_MASTER */
                + nla_total_size(sizeof(u32)) /* NDA_FLAGS_EXT */
                + nla_total_size(sizeof(u16)) /* NDA_VLAN */
                + nla_total_size(sizeof(struct nda_cacheinfo))
                + nla_total_size(0) /* NDA_FDB_EXT_ATTRS */
                + nla_total_size(sizeof(u8)); /* NFEA_ACTIVITY_NOTIFY */
}

static void fdb_notify(struct net_bridge *br,
                       const struct net_bridge_fdb_entry *fdb, int type,
                       bool swdev_notify)
{
        struct net *net = dev_net(br->dev);
        struct sk_buff *skb;
        int err = -ENOBUFS;

        if (swdev_notify)
                br_switchdev_fdb_notify(br, fdb, type);

        skb = nlmsg_new(fdb_nlmsg_size(), GFP_ATOMIC);
        if (skb == NULL)
                goto errout;

        err = fdb_fill_info(skb, br, fdb, 0, 0, type, 0);
        if (err < 0) {
                /* -EMSGSIZE implies BUG in fdb_nlmsg_size() */
                WARN_ON(err == -EMSGSIZE);
                kfree_skb(skb);
                goto errout;
        }
        rtnl_notify(skb, net, 0, RTNLGRP_NEIGH, NULL, GFP_ATOMIC);
        return;
errout:
        rtnl_set_sk_err(net, RTNLGRP_NEIGH, err);
}

static struct net_bridge_fdb_entry *fdb_find_rcu(struct rhashtable *tbl,
                                                 const unsigned char *addr,
                                                 __u16 vid)
{
        struct net_bridge_fdb_key key;

        WARN_ON_ONCE(!rcu_read_lock_held());

        key.vlan_id = vid;
        memcpy(key.addr.addr, addr, sizeof(key.addr.addr));

        return rhashtable_lookup(tbl, &key, br_fdb_rht_params);
}

/* requires bridge hash_lock */
static struct net_bridge_fdb_entry *br_fdb_find(struct net_bridge *br,
                                                const unsigned char *addr,
                                                __u16 vid)
{
        struct net_bridge_fdb_entry *fdb;

        lockdep_assert_held_once(&br->hash_lock);

        rcu_read_lock();
        fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
        rcu_read_unlock();

        return fdb;
}

struct net_device *br_fdb_find_port(const struct net_device *br_dev,
                                    const unsigned char *addr,
                                    __u16 vid)
{
        struct net_bridge_fdb_entry *f;
        struct net_device *dev = NULL;
        struct net_bridge *br;

        ASSERT_RTNL();

        if (!netif_is_bridge_master(br_dev))
                return NULL;

        br = netdev_priv(br_dev);
        rcu_read_lock();
        f = br_fdb_find_rcu(br, addr, vid);
        if (f && f->dst)
                dev = f->dst->dev;
        rcu_read_unlock();

        return dev;
}
EXPORT_SYMBOL_GPL(br_fdb_find_port);

struct net_bridge_fdb_entry *br_fdb_find_rcu(struct net_bridge *br,
                                             const unsigned char *addr,
                                             __u16 vid)
{
        return fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
}

/* When a static FDB entry is added, the mac address from the entry is
 * added to the bridge private HW address list and all required ports
 * are then updated with the new information.
 * Called under RTNL.
 */
static void fdb_add_hw_addr(struct net_bridge *br, const unsigned char *addr)
{
        int err;
        struct net_bridge_port *p;

        ASSERT_RTNL();

        list_for_each_entry(p, &br->port_list, list) {
                if (!br_promisc_port(p)) {
                        err = dev_uc_add(p->dev, addr);
                        if (err)
                                goto undo;
                }
        }

        return;
undo:
        list_for_each_entry_continue_reverse(p, &br->port_list, list) {
                if (!br_promisc_port(p))
                        dev_uc_del(p->dev, addr);
        }
}

/* When a static FDB entry is deleted, the HW address from that entry is
 * also removed from the bridge private HW address list and updates all
 * the ports with needed information.
 * Called under RTNL.
 */
static void fdb_del_hw_addr(struct net_bridge *br, const unsigned char *addr)
{
        struct net_bridge_port *p;

        ASSERT_RTNL();

        list_for_each_entry(p, &br->port_list, list) {
                if (!br_promisc_port(p))
                        dev_uc_del(p->dev, addr);
        }
}

static void fdb_delete(struct net_bridge *br, struct net_bridge_fdb_entry *f,
                       bool swdev_notify)
{
        trace_fdb_delete(br, f);

        if (test_bit(BR_FDB_STATIC, &f->flags))
                fdb_del_hw_addr(br, f->key.addr.addr);

        hlist_del_init_rcu(&f->fdb_node);
        rhashtable_remove_fast(&br->fdb_hash_tbl, &f->rhnode,
                               br_fdb_rht_params);
        if (test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, &f->flags))
                atomic_dec(&br->fdb_n_learned);
        fdb_notify(br, f, RTM_DELNEIGH, swdev_notify);
        kfree_rcu(f, rcu);
}

/* Delete a local entry if no other port had the same address.
 *
 * This function should only be called on entries with BR_FDB_LOCAL set,
 * so even with BR_FDB_ADDED_BY_USER cleared we never need to increase
 * the accounting for dynamically learned entries again.
 */
static void fdb_delete_local(struct net_bridge *br,
                             const struct net_bridge_port *p,
                             struct net_bridge_fdb_entry *f)
{
        const unsigned char *addr = f->key.addr.addr;
        struct net_bridge_vlan_group *vg;
        const struct net_bridge_vlan *v;
        struct net_bridge_port *op;
        u16 vid = f->key.vlan_id;

        /* Maybe another port has same hw addr? */
        list_for_each_entry(op, &br->port_list, list) {
                vg = nbp_vlan_group(op);
                if (op != p && ether_addr_equal(op->dev->dev_addr, addr) &&
                    (!vid || br_vlan_find(vg, vid))) {
                        f->dst = op;
                        clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
                        return;
                }
        }

        vg = br_vlan_group(br);
        v = br_vlan_find(vg, vid);
        /* Maybe bridge device has same hw addr? */
        if (p && ether_addr_equal(br->dev->dev_addr, addr) &&
            (!vid || (v && br_vlan_should_use(v)))) {
                f->dst = NULL;
                clear_bit(BR_FDB_ADDED_BY_USER, &f->flags);
                return;
        }

        fdb_delete(br, f, true);
}

void br_fdb_find_delete_local(struct net_bridge *br,
                              const struct net_bridge_port *p,
                              const unsigned char *addr, u16 vid)
{
        struct net_bridge_fdb_entry *f;

        spin_lock_bh(&br->hash_lock);
        f = br_fdb_find(br, addr, vid);
        if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
            !test_bit(BR_FDB_ADDED_BY_USER, &f->flags) && f->dst == p)
                fdb_delete_local(br, p, f);
        spin_unlock_bh(&br->hash_lock);
}

static struct net_bridge_fdb_entry *fdb_create(struct net_bridge *br,
                                               struct net_bridge_port *source,
                                               const unsigned char *addr,
                                               __u16 vid,
                                               unsigned long flags)
{
        bool learned = !test_bit(BR_FDB_ADDED_BY_USER, &flags) &&
                       !test_bit(BR_FDB_LOCAL, &flags);
        u32 max_learned = READ_ONCE(br->fdb_max_learned);
        struct net_bridge_fdb_entry *fdb;
        int err;

        if (likely(learned)) {
                int n_learned = atomic_read(&br->fdb_n_learned);

                if (unlikely(max_learned && n_learned >= max_learned))
                        return NULL;
                __set_bit(BR_FDB_DYNAMIC_LEARNED, &flags);
        }

        fdb = kmem_cache_alloc(br_fdb_cache, GFP_ATOMIC);
        if (!fdb)
                return NULL;

        memcpy(fdb->key.addr.addr, addr, ETH_ALEN);
        WRITE_ONCE(fdb->dst, source);
        fdb->key.vlan_id = vid;
        fdb->flags = flags;
        fdb->updated = fdb->used = jiffies;
        err = rhashtable_lookup_insert_fast(&br->fdb_hash_tbl, &fdb->rhnode,
                                            br_fdb_rht_params);
        if (err) {
                kmem_cache_free(br_fdb_cache, fdb);
                return NULL;
        }

        if (likely(learned))
                atomic_inc(&br->fdb_n_learned);

        hlist_add_head_rcu(&fdb->fdb_node, &br->fdb_list);

        return fdb;
}

static int fdb_add_local(struct net_bridge *br, struct net_bridge_port *source,
                         const unsigned char *addr, u16 vid)
{
        struct net_bridge_fdb_entry *fdb;

        if (!is_valid_ether_addr(addr))
                return -EINVAL;

        fdb = br_fdb_find(br, addr, vid);
        if (fdb) {
                /* it is okay to have multiple ports with same
                 * address, just use the first one.
                 */
                if (test_bit(BR_FDB_LOCAL, &fdb->flags))
                        return 0;
                br_warn(br, "adding interface %s with same address as a received packet (addr:%pM, vlan:%u)\n",
                        source ? source->dev->name : br->dev->name, addr, vid);
                fdb_delete(br, fdb, true);
        }

        fdb = fdb_create(br, source, addr, vid,
                         BIT(BR_FDB_LOCAL) | BIT(BR_FDB_STATIC));
        if (!fdb)
                return -ENOMEM;

        fdb_add_hw_addr(br, addr);
        fdb_notify(br, fdb, RTM_NEWNEIGH, true);
        return 0;
}

void br_fdb_changeaddr(struct net_bridge_port *p, const unsigned char *newaddr)
{
        struct net_bridge_vlan_group *vg;
        struct net_bridge_fdb_entry *f;
        struct net_bridge *br = p->br;
        struct net_bridge_vlan *v;
        bool local_vlan_0;

        local_vlan_0 = br_opt_get(br, BROPT_FDB_LOCAL_VLAN_0);

        spin_lock_bh(&br->hash_lock);
        vg = nbp_vlan_group(p);
        hlist_for_each_entry(f, &br->fdb_list, fdb_node) {
                if (f->dst == p && test_bit(BR_FDB_LOCAL, &f->flags) &&
                    !test_bit(BR_FDB_ADDED_BY_USER, &f->flags)) {
                        /* delete old one */
                        fdb_delete_local(br, p, f);

                        /* if this port has no vlan information configured, or
                         * local entries are only kept on VLAN 0, we can safely
                         * be done at this point.
                         */
                        if (!vg || !vg->num_vlans || local_vlan_0)
                                goto insert;
                }
        }

insert:
        /* insert new address,  may fail if invalid address or dup. */
        fdb_add_local(br, p, newaddr, 0);

        if (!vg || !vg->num_vlans || local_vlan_0)
                goto done;

        /* Now add entries for every VLAN configured on the port.
         * This function runs under RTNL so the bitmap will not change
         * from under us.
         */
        list_for_each_entry(v, &vg->vlan_list, vlist)
                fdb_add_local(br, p, newaddr, v->vid);

done:
        spin_unlock_bh(&br->hash_lock);
}

void br_fdb_change_mac_address(struct net_bridge *br, const u8 *newaddr)
{
        struct net_bridge_vlan_group *vg;
        struct net_bridge_fdb_entry *f;
        struct net_bridge_vlan *v;
        bool local_vlan_0;

        local_vlan_0 = br_opt_get(br, BROPT_FDB_LOCAL_VLAN_0);

        spin_lock_bh(&br->hash_lock);

        /* If old entry was unassociated with any port, then delete it. */
        f = br_fdb_find(br, br->dev->dev_addr, 0);
        if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
            !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
                fdb_delete_local(br, NULL, f);

        fdb_add_local(br, NULL, newaddr, 0);
        vg = br_vlan_group(br);
        if (!vg || !vg->num_vlans || local_vlan_0)
                goto out;
        /* Now remove and add entries for every VLAN configured on the
         * bridge.  This function runs under RTNL so the bitmap will not
         * change from under us.
         */
        list_for_each_entry(v, &vg->vlan_list, vlist) {
                if (!br_vlan_should_use(v))
                        continue;
                f = br_fdb_find(br, br->dev->dev_addr, v->vid);
                if (f && test_bit(BR_FDB_LOCAL, &f->flags) &&
                    !f->dst && !test_bit(BR_FDB_ADDED_BY_USER, &f->flags))
                        fdb_delete_local(br, NULL, f);
                fdb_add_local(br, NULL, newaddr, v->vid);
        }
out:
        spin_unlock_bh(&br->hash_lock);
}

void br_fdb_cleanup(struct work_struct *work)
{
        struct net_bridge *br = container_of(work, struct net_bridge,
                                             gc_work.work);
        struct net_bridge_fdb_entry *f = NULL;
        unsigned long delay = hold_time(br);
        unsigned long work_delay = delay;
        unsigned long now = jiffies;

        /* this part is tricky, in order to avoid blocking learning and
         * consequently forwarding, we rely on rcu to delete objects with
         * delayed freeing allowing us to continue traversing
         */
        rcu_read_lock();
        hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
                unsigned long this_timer = READ_ONCE(f->updated) + delay;

                if (test_bit(BR_FDB_STATIC, &f->flags) ||
                    test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags)) {
                        if (test_bit(BR_FDB_NOTIFY, &f->flags)) {
                                if (time_after(this_timer, now))
                                        work_delay = min(work_delay,
                                                         this_timer - now);
                                else if (!test_and_set_bit(BR_FDB_NOTIFY_INACTIVE,
                                                           &f->flags))
                                        fdb_notify(br, f, RTM_NEWNEIGH, false);
                        }
                        continue;
                }

                if (time_after(this_timer, now)) {
                        work_delay = min(work_delay, this_timer - now);
                } else {
                        spin_lock_bh(&br->hash_lock);
                        if (!hlist_unhashed(&f->fdb_node))
                                fdb_delete(br, f, true);
                        spin_unlock_bh(&br->hash_lock);
                }
        }
        rcu_read_unlock();

        /* Cleanup minimum 10 milliseconds apart */
        work_delay = max_t(unsigned long, work_delay, msecs_to_jiffies(10));
        mod_delayed_work(system_long_wq, &br->gc_work, work_delay);
}

static void br_fdb_delete_locals_per_vlan_port(struct net_bridge *br,
                                               struct net_bridge_port *p)
{
        struct net_bridge_vlan_group *vg;
        struct net_bridge_vlan *v;
        struct net_device *dev;

        if (p) {
                vg = nbp_vlan_group(p);
                dev = p->dev;
        } else {
                vg = br_vlan_group(br);
                dev = br->dev;
        }

        list_for_each_entry(v, &vg->vlan_list, vlist)
                br_fdb_find_delete_local(br, p, dev->dev_addr, v->vid);
}

static void br_fdb_delete_locals_per_vlan(struct net_bridge *br)
{
        struct net_bridge_port *p;

        ASSERT_RTNL();

        list_for_each_entry(p, &br->port_list, list)
                br_fdb_delete_locals_per_vlan_port(br, p);

        br_fdb_delete_locals_per_vlan_port(br, NULL);
}

static int br_fdb_insert_locals_per_vlan_port(struct net_bridge *br,
                                              struct net_bridge_port *p,
                                              struct netlink_ext_ack *extack)
{
        struct net_bridge_vlan_group *vg;
        struct net_bridge_vlan *v;
        struct net_device *dev;
        int err;

        if (p) {
                vg = nbp_vlan_group(p);
                dev = p->dev;
        } else {
                vg = br_vlan_group(br);
                dev = br->dev;
        }

        list_for_each_entry(v, &vg->vlan_list, vlist) {
                if (!br_vlan_should_use(v))
                        continue;

                err = br_fdb_add_local(br, p, dev->dev_addr, v->vid);
                if (err)
                        return err;
        }

        return 0;
}

static int br_fdb_insert_locals_per_vlan(struct net_bridge *br,
                                         struct netlink_ext_ack *extack)
{
        struct net_bridge_port *p;
        int err;

        ASSERT_RTNL();

        list_for_each_entry(p, &br->port_list, list) {
                err = br_fdb_insert_locals_per_vlan_port(br, p, extack);
                if (err)
                        goto rollback;
        }

        err = br_fdb_insert_locals_per_vlan_port(br, NULL, extack);
        if (err)
                goto rollback;

        return 0;

rollback:
        NL_SET_ERR_MSG_MOD(extack, "fdb_local_vlan_0 toggle: FDB entry insertion failed");
        br_fdb_delete_locals_per_vlan(br);
        return err;
}

int br_fdb_toggle_local_vlan_0(struct net_bridge *br, bool on,
                               struct netlink_ext_ack *extack)
{
        if (!on)
                return br_fdb_insert_locals_per_vlan(br, extack);

        br_fdb_delete_locals_per_vlan(br);
        return 0;
}

static bool __fdb_flush_matches(const struct net_bridge *br,
                                const struct net_bridge_fdb_entry *f,
                                const struct net_bridge_fdb_flush_desc *desc)
{
        const struct net_bridge_port *dst = READ_ONCE(f->dst);
        int port_ifidx = dst ? dst->dev->ifindex : br->dev->ifindex;

        if (desc->vlan_id && desc->vlan_id != f->key.vlan_id)
                return false;
        if (desc->port_ifindex && desc->port_ifindex != port_ifidx)
                return false;
        if (desc->flags_mask && (f->flags & desc->flags_mask) != desc->flags)
                return false;

        return true;
}

/* Flush forwarding database entries matching the description */
void br_fdb_flush(struct net_bridge *br,
                  const struct net_bridge_fdb_flush_desc *desc)
{
        struct net_bridge_fdb_entry *f;

        rcu_read_lock();
        hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
                if (!__fdb_flush_matches(br, f, desc))
                        continue;

                spin_lock_bh(&br->hash_lock);
                if (!hlist_unhashed(&f->fdb_node))
                        fdb_delete(br, f, true);
                spin_unlock_bh(&br->hash_lock);
        }
        rcu_read_unlock();
}

static unsigned long __ndm_state_to_fdb_flags(u16 ndm_state)
{
        unsigned long flags = 0;

        if (ndm_state & NUD_PERMANENT)
                __set_bit(BR_FDB_LOCAL, &flags);
        if (ndm_state & NUD_NOARP)
                __set_bit(BR_FDB_STATIC, &flags);

        return flags;
}

static unsigned long __ndm_flags_to_fdb_flags(u8 ndm_flags)
{
        unsigned long flags = 0;

        if (ndm_flags & NTF_USE)
                __set_bit(BR_FDB_ADDED_BY_USER, &flags);
        if (ndm_flags & NTF_EXT_LEARNED)
                __set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &flags);
        if (ndm_flags & NTF_OFFLOADED)
                __set_bit(BR_FDB_OFFLOADED, &flags);
        if (ndm_flags & NTF_STICKY)
                __set_bit(BR_FDB_STICKY, &flags);

        return flags;
}

static int __fdb_flush_validate_ifindex(const struct net_bridge *br,
                                        int ifindex,
                                        struct netlink_ext_ack *extack)
{
        const struct net_device *dev;

        dev = __dev_get_by_index(dev_net(br->dev), ifindex);
        if (!dev) {
                NL_SET_ERR_MSG_MOD(extack, "Unknown flush device ifindex");
                return -ENODEV;
        }
        if (!netif_is_bridge_master(dev) && !netif_is_bridge_port(dev)) {
                NL_SET_ERR_MSG_MOD(extack, "Flush device is not a bridge or bridge port");
                return -EINVAL;
        }
        if (netif_is_bridge_master(dev) && dev != br->dev) {
                NL_SET_ERR_MSG_MOD(extack,
                                   "Flush bridge device does not match target bridge device");
                return -EINVAL;
        }
        if (netif_is_bridge_port(dev)) {
                struct net_bridge_port *p = br_port_get_rtnl(dev);

                if (p->br != br) {
                        NL_SET_ERR_MSG_MOD(extack, "Port belongs to a different bridge device");
                        return -EINVAL;
                }
        }

        return 0;
}

static const struct nla_policy br_fdb_del_bulk_policy[NDA_MAX + 1] = {
        [NDA_VLAN]      = NLA_POLICY_RANGE(NLA_U16, 1, VLAN_N_VID - 2),
        [NDA_IFINDEX]   = NLA_POLICY_MIN(NLA_S32, 1),
        [NDA_NDM_STATE_MASK]    = { .type = NLA_U16 },
        [NDA_NDM_FLAGS_MASK]    = { .type = NLA_U8 },
};

int br_fdb_delete_bulk(struct nlmsghdr *nlh, struct net_device *dev,
                       struct netlink_ext_ack *extack)
{
        struct net_bridge_fdb_flush_desc desc = {};
        struct ndmsg *ndm = nlmsg_data(nlh);
        struct net_bridge_port *p = NULL;
        struct nlattr *tb[NDA_MAX + 1];
        struct net_bridge *br;
        u8 ndm_flags;
        int err;

        ndm_flags = ndm->ndm_flags & ~FDB_FLUSH_IGNORED_NDM_FLAGS;

        err = nlmsg_parse(nlh, sizeof(*ndm), tb, NDA_MAX,
                          br_fdb_del_bulk_policy, extack);
        if (err)
                return err;

        if (netif_is_bridge_master(dev)) {
                br = netdev_priv(dev);
        } else {
                p = br_port_get_rtnl(dev);
                if (!p) {
                        NL_SET_ERR_MSG_MOD(extack, "Device is not a bridge port");
                        return -EINVAL;
                }
                br = p->br;
        }

        if (tb[NDA_VLAN])
                desc.vlan_id = nla_get_u16(tb[NDA_VLAN]);

        if (ndm_flags & ~FDB_FLUSH_ALLOWED_NDM_FLAGS) {
                NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm flag bits set");
                return -EINVAL;
        }
        if (ndm->ndm_state & ~FDB_FLUSH_ALLOWED_NDM_STATES) {
                NL_SET_ERR_MSG(extack, "Unsupported fdb flush ndm state bits set");
                return -EINVAL;
        }

        desc.flags |= __ndm_state_to_fdb_flags(ndm->ndm_state);
        desc.flags |= __ndm_flags_to_fdb_flags(ndm_flags);
        if (tb[NDA_NDM_STATE_MASK]) {
                u16 ndm_state_mask = nla_get_u16(tb[NDA_NDM_STATE_MASK]);

                desc.flags_mask |= __ndm_state_to_fdb_flags(ndm_state_mask);
        }
        if (tb[NDA_NDM_FLAGS_MASK]) {
                u8 ndm_flags_mask = nla_get_u8(tb[NDA_NDM_FLAGS_MASK]);

                desc.flags_mask |= __ndm_flags_to_fdb_flags(ndm_flags_mask);
        }
        if (tb[NDA_IFINDEX]) {
                int ifidx = nla_get_s32(tb[NDA_IFINDEX]);

                err = __fdb_flush_validate_ifindex(br, ifidx, extack);
                if (err)
                        return err;
                desc.port_ifindex = ifidx;
        } else if (p) {
                /* flush was invoked with port device and NTF_MASTER */
                desc.port_ifindex = p->dev->ifindex;
        }

        br_debug(br, "flushing port ifindex: %d vlan id: %u flags: 0x%lx flags mask: 0x%lx\n",
                 desc.port_ifindex, desc.vlan_id, desc.flags, desc.flags_mask);

        br_fdb_flush(br, &desc);

        return 0;
}

/* Flush all entries referring to a specific port.
 * if do_all is set also flush static entries
 * if vid is set delete all entries that match the vlan_id
 */
void br_fdb_delete_by_port(struct net_bridge *br,
                           const struct net_bridge_port *p,
                           u16 vid,
                           int do_all)
{
        struct net_bridge_fdb_entry *f;
        struct hlist_node *tmp;

        spin_lock_bh(&br->hash_lock);
        hlist_for_each_entry_safe(f, tmp, &br->fdb_list, fdb_node) {
                if (f->dst != p)
                        continue;

                if (!do_all)
                        if (test_bit(BR_FDB_STATIC, &f->flags) ||
                            (test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &f->flags) &&
                             !test_bit(BR_FDB_OFFLOADED, &f->flags)) ||
                            (vid && f->key.vlan_id != vid))
                                continue;

                if (test_bit(BR_FDB_LOCAL, &f->flags))
                        fdb_delete_local(br, p, f);
                else
                        fdb_delete(br, f, true);
        }
        spin_unlock_bh(&br->hash_lock);
}

#if IS_ENABLED(CONFIG_ATM_LANE)
/* Interface used by ATM LANE hook to test
 * if an addr is on some other bridge port */
int br_fdb_test_addr(struct net_device *dev, unsigned char *addr)
{
        struct net_bridge_fdb_entry *fdb;
        struct net_bridge_port *port;
        int ret;

        rcu_read_lock();
        port = br_port_get_rcu(dev);
        if (!port)
                ret = 0;
        else {
                const struct net_bridge_port *dst = NULL;

                fdb = br_fdb_find_rcu(port->br, addr, 0);
                if (fdb)
                        dst = READ_ONCE(fdb->dst);

                ret = dst && dst->dev != dev &&
                      dst->state == BR_STATE_FORWARDING;
        }
        rcu_read_unlock();

        return ret;
}
#endif /* CONFIG_ATM_LANE */

/*
 * Fill buffer with forwarding table records in
 * the API format.
 */
int br_fdb_fillbuf(struct net_bridge *br, void *buf,
                   unsigned long maxnum, unsigned long skip)
{
        struct net_bridge_fdb_entry *f;
        struct __fdb_entry *fe = buf;
        unsigned long delta;
        int num = 0;

        memset(buf, 0, maxnum*sizeof(struct __fdb_entry));

        rcu_read_lock();
        hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
                if (num >= maxnum)
                        break;

                if (has_expired(br, f))
                        continue;

                /* ignore pseudo entry for local MAC address */
                if (!f->dst)
                        continue;

                if (skip) {
                        --skip;
                        continue;
                }

                /* convert from internal format to API */
                memcpy(fe->mac_addr, f->key.addr.addr, ETH_ALEN);

                /* due to ABI compat need to split into hi/lo */
                fe->port_no = f->dst->port_no;
                fe->port_hi = f->dst->port_no >> 8;

                fe->is_local = test_bit(BR_FDB_LOCAL, &f->flags);
                if (!test_bit(BR_FDB_STATIC, &f->flags)) {
                        delta = jiffies - READ_ONCE(f->updated);
                        fe->ageing_timer_value =
                                jiffies_delta_to_clock_t(delta);
                }
                ++fe;
                ++num;
        }
        rcu_read_unlock();

        return num;
}

/* Add entry for local address of interface */
int br_fdb_add_local(struct net_bridge *br, struct net_bridge_port *source,
                     const unsigned char *addr, u16 vid)
{
        int ret;

        spin_lock_bh(&br->hash_lock);
        ret = fdb_add_local(br, source, addr, vid);
        spin_unlock_bh(&br->hash_lock);
        return ret;
}

/* returns true if the fdb was modified */
static bool __fdb_mark_active(struct net_bridge_fdb_entry *fdb)
{
        return !!(test_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags) &&
                  test_and_clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags));
}

void br_fdb_update(struct net_bridge *br, struct net_bridge_port *source,
                   const unsigned char *addr, u16 vid, unsigned long flags)
{
        struct net_bridge_fdb_entry *fdb;

        /* some users want to always flood. */
        if (hold_time(br) == 0)
                return;

        fdb = fdb_find_rcu(&br->fdb_hash_tbl, addr, vid);
        if (likely(fdb)) {
                /* attempt to update an entry for a local interface */
                if (unlikely(test_bit(BR_FDB_LOCAL, &fdb->flags))) {
                        if (net_ratelimit())
                                br_warn(br, "received packet on %s with own address as source address (addr:%pM, vlan:%u)\n",
                                        source->dev->name, addr, vid);
                } else {
                        unsigned long now = jiffies;
                        bool fdb_modified = false;

                        if (now != READ_ONCE(fdb->updated)) {
                                WRITE_ONCE(fdb->updated, now);
                                fdb_modified = __fdb_mark_active(fdb);
                        }

                        /* fastpath: update of existing entry */
                        if (unlikely(source != READ_ONCE(fdb->dst) &&
                                     !test_bit(BR_FDB_STICKY, &fdb->flags))) {
                                br_switchdev_fdb_notify(br, fdb, RTM_DELNEIGH);
                                WRITE_ONCE(fdb->dst, source);
                                fdb_modified = true;
                                /* Take over HW learned entry */
                                if (unlikely(test_bit(BR_FDB_ADDED_BY_EXT_LEARN,
                                                      &fdb->flags)))
                                        clear_bit(BR_FDB_ADDED_BY_EXT_LEARN,
                                                  &fdb->flags);
                                /* Clear locked flag when roaming to an
                                 * unlocked port.
                                 */
                                if (unlikely(test_bit(BR_FDB_LOCKED, &fdb->flags)))
                                        clear_bit(BR_FDB_LOCKED, &fdb->flags);
                        }

                        if (unlikely(test_bit(BR_FDB_ADDED_BY_USER, &flags))) {
                                set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
                                if (test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED,
                                                       &fdb->flags))
                                        atomic_dec(&br->fdb_n_learned);
                        }
                        if (unlikely(fdb_modified)) {
                                trace_br_fdb_update(br, source, addr, vid, flags);
                                fdb_notify(br, fdb, RTM_NEWNEIGH, true);
                        }
                }
        } else {
                spin_lock(&br->hash_lock);
                fdb = fdb_create(br, source, addr, vid, flags);
                if (fdb) {
                        trace_br_fdb_update(br, source, addr, vid, flags);
                        fdb_notify(br, fdb, RTM_NEWNEIGH, true);
                }
                /* else  we lose race and someone else inserts
                 * it first, don't bother updating
                 */
                spin_unlock(&br->hash_lock);
        }
}

/* Dump information about entries, in response to GETNEIGH */
int br_fdb_dump(struct sk_buff *skb,
                struct netlink_callback *cb,
                struct net_device *dev,
                struct net_device *filter_dev,
                int *idx)
{
        struct ndo_fdb_dump_context *ctx = (void *)cb->ctx;
        struct net_bridge *br = netdev_priv(dev);
        struct net_bridge_fdb_entry *f;
        int err = 0;

        if (!netif_is_bridge_master(dev))
                return err;

        if (!filter_dev) {
                err = ndo_dflt_fdb_dump(skb, cb, dev, NULL, idx);
                if (err < 0)
                        return err;
        }

        rcu_read_lock();
        hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
                if (*idx < ctx->fdb_idx)
                        goto skip;
                if (filter_dev && (!f->dst || f->dst->dev != filter_dev)) {
                        if (filter_dev != dev)
                                goto skip;
                        /* !f->dst is a special case for bridge
                         * It means the MAC belongs to the bridge
                         * Therefore need a little more filtering
                         * we only want to dump the !f->dst case
                         */
                        if (f->dst)
                                goto skip;
                }
                if (!filter_dev && f->dst)
                        goto skip;

                err = fdb_fill_info(skb, br, f,
                                    NETLINK_CB(cb->skb).portid,
                                    cb->nlh->nlmsg_seq,
                                    RTM_NEWNEIGH,
                                    NLM_F_MULTI);
                if (err < 0)
                        break;
skip:
                *idx += 1;
        }
        rcu_read_unlock();

        return err;
}

int br_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)
{
        struct net_bridge *br = netdev_priv(dev);
        struct net_bridge_fdb_entry *f;
        int err = 0;

        rcu_read_lock();
        f = br_fdb_find_rcu(br, addr, vid);
        if (!f) {
                NL_SET_ERR_MSG(extack, "Fdb entry not found");
                err = -ENOENT;
                goto errout;
        }

        err = fdb_fill_info(skb, br, f, portid, seq,
                            RTM_NEWNEIGH, 0);
errout:
        rcu_read_unlock();
        return err;
}

/* returns true if the fdb is modified */
static bool fdb_handle_notify(struct net_bridge_fdb_entry *fdb, u8 notify)
{
        bool modified = false;

        /* allow to mark an entry as inactive, usually done on creation */
        if ((notify & FDB_NOTIFY_INACTIVE_BIT) &&
            !test_and_set_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags))
                modified = true;

        if ((notify & FDB_NOTIFY_BIT) &&
            !test_and_set_bit(BR_FDB_NOTIFY, &fdb->flags)) {
                /* enabled activity tracking */
                modified = true;
        } else if (!(notify & FDB_NOTIFY_BIT) &&
                   test_and_clear_bit(BR_FDB_NOTIFY, &fdb->flags)) {
                /* disabled activity tracking, clear notify state */
                clear_bit(BR_FDB_NOTIFY_INACTIVE, &fdb->flags);
                modified = true;
        }

        return modified;
}

/* Update (create or replace) forwarding database entry */
static int fdb_add_entry(struct net_bridge *br, struct net_bridge_port *source,
                         const u8 *addr, struct ndmsg *ndm, u16 flags, u16 vid,
                         struct nlattr *nfea_tb[])
{
        bool is_sticky = !!(ndm->ndm_flags & NTF_STICKY);
        bool refresh = !nfea_tb[NFEA_DONT_REFRESH];
        struct net_bridge_fdb_entry *fdb;
        u16 state = ndm->ndm_state;
        bool modified = false;
        u8 notify = 0;

        /* If the port cannot learn allow only local and static entries */
        if (source && !(state & NUD_PERMANENT) && !(state & NUD_NOARP) &&
            !(source->state == BR_STATE_LEARNING ||
              source->state == BR_STATE_FORWARDING))
                return -EPERM;

        if (!source && !(state & NUD_PERMANENT)) {
                pr_info("bridge: RTM_NEWNEIGH %s without NUD_PERMANENT\n",
                        br->dev->name);
                return -EINVAL;
        }

        if (is_sticky && (state & NUD_PERMANENT))
                return -EINVAL;

        if (nfea_tb[NFEA_ACTIVITY_NOTIFY]) {
                notify = nla_get_u8(nfea_tb[NFEA_ACTIVITY_NOTIFY]);
                if ((notify & ~BR_FDB_NOTIFY_SETTABLE_BITS) ||
                    (notify & BR_FDB_NOTIFY_SETTABLE_BITS) == FDB_NOTIFY_INACTIVE_BIT)
                        return -EINVAL;
        }

        fdb = br_fdb_find(br, addr, vid);
        if (fdb == NULL) {
                if (!(flags & NLM_F_CREATE))
                        return -ENOENT;

                fdb = fdb_create(br, source, addr, vid,
                                 BIT(BR_FDB_ADDED_BY_USER));
                if (!fdb)
                        return -ENOMEM;

                modified = true;
        } else {
                if (flags & NLM_F_EXCL)
                        return -EEXIST;

                if (READ_ONCE(fdb->dst) != source) {
                        WRITE_ONCE(fdb->dst, source);
                        modified = true;
                }

                set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);
                if (test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, &fdb->flags))
                        atomic_dec(&br->fdb_n_learned);
        }

        if (fdb_to_nud(br, fdb) != state) {
                if (state & NUD_PERMANENT) {
                        set_bit(BR_FDB_LOCAL, &fdb->flags);
                        if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
                                fdb_add_hw_addr(br, addr);
                } else if (state & NUD_NOARP) {
                        clear_bit(BR_FDB_LOCAL, &fdb->flags);
                        if (!test_and_set_bit(BR_FDB_STATIC, &fdb->flags))
                                fdb_add_hw_addr(br, addr);
                } else {
                        clear_bit(BR_FDB_LOCAL, &fdb->flags);
                        if (test_and_clear_bit(BR_FDB_STATIC, &fdb->flags))
                                fdb_del_hw_addr(br, addr);
                }

                modified = true;
        }

        if (is_sticky != test_bit(BR_FDB_STICKY, &fdb->flags)) {
                change_bit(BR_FDB_STICKY, &fdb->flags);
                modified = true;
        }

        if (test_and_clear_bit(BR_FDB_LOCKED, &fdb->flags))
                modified = true;

        if (fdb_handle_notify(fdb, notify))
                modified = true;

        WRITE_ONCE(fdb->used, jiffies);
        if (modified) {
                if (refresh)
                        WRITE_ONCE(fdb->updated, jiffies);
                fdb_notify(br, fdb, RTM_NEWNEIGH, true);
        }

        return 0;
}

static int __br_fdb_add(struct ndmsg *ndm, struct net_bridge *br,
                        struct net_bridge_port *p, const unsigned char *addr,
                        u16 nlh_flags, u16 vid, struct nlattr *nfea_tb[],
                        bool *notified, struct netlink_ext_ack *extack)
{
        int err = 0;

        if (ndm->ndm_flags & NTF_USE) {
                if (!p) {
                        pr_info("bridge: RTM_NEWNEIGH %s with NTF_USE is not supported\n",
                                br->dev->name);
                        return -EINVAL;
                }
                if (!nbp_state_should_learn(p))
                        return 0;

                local_bh_disable();
                rcu_read_lock();
                br_fdb_update(br, p, addr, vid, BIT(BR_FDB_ADDED_BY_USER));
                rcu_read_unlock();
                local_bh_enable();
        } else if (ndm->ndm_flags & NTF_EXT_LEARNED) {
                if (!p && !(ndm->ndm_state & NUD_PERMANENT)) {
                        NL_SET_ERR_MSG_MOD(extack,
                                           "FDB entry towards bridge must be permanent");
                        return -EINVAL;
                }
                err = br_fdb_external_learn_add(br, p, addr, vid, false, true);
        } else {
                spin_lock_bh(&br->hash_lock);
                err = fdb_add_entry(br, p, addr, ndm, nlh_flags, vid, nfea_tb);
                spin_unlock_bh(&br->hash_lock);
        }

        if (!err)
                *notified = true;
        return err;
}

static const struct nla_policy br_nda_fdb_pol[NFEA_MAX + 1] = {
        [NFEA_ACTIVITY_NOTIFY]  = { .type = NLA_U8 },
        [NFEA_DONT_REFRESH]     = { .type = NLA_FLAG },
};

/* Add new permanent fdb entry with RTM_NEWNEIGH */
int br_fdb_add(struct ndmsg *ndm, struct nlattr *tb[],
               struct net_device *dev,
               const unsigned char *addr, u16 vid, u16 nlh_flags,
               bool *notified, struct netlink_ext_ack *extack)
{
        struct nlattr *nfea_tb[NFEA_MAX + 1], *attr;
        struct net_bridge_vlan_group *vg;
        struct net_bridge_port *p = NULL;
        struct net_bridge_vlan *v;
        struct net_bridge *br = NULL;
        u32 ext_flags = 0;
        int err = 0;

        trace_br_fdb_add(ndm, dev, addr, vid, nlh_flags);

        if (!(ndm->ndm_state & (NUD_PERMANENT|NUD_NOARP|NUD_REACHABLE))) {
                pr_info("bridge: RTM_NEWNEIGH with invalid state %#x\n", ndm->ndm_state);
                return -EINVAL;
        }

        if (is_zero_ether_addr(addr)) {
                pr_info("bridge: RTM_NEWNEIGH with invalid ether address\n");
                return -EINVAL;
        }

        if (netif_is_bridge_master(dev)) {
                br = netdev_priv(dev);
                vg = br_vlan_group(br);
        } else {
                p = br_port_get_rtnl(dev);
                if (!p) {
                        pr_info("bridge: RTM_NEWNEIGH %s not a bridge port\n",
                                dev->name);
                        return -EINVAL;
                }
                br = p->br;
                vg = nbp_vlan_group(p);
        }

        if (tb[NDA_FLAGS_EXT])
                ext_flags = nla_get_u32(tb[NDA_FLAGS_EXT]);

        if (ext_flags & NTF_EXT_LOCKED) {
                NL_SET_ERR_MSG_MOD(extack, "Cannot add FDB entry with \"locked\" flag set");
                return -EINVAL;
        }

        if (tb[NDA_FDB_EXT_ATTRS]) {
                attr = tb[NDA_FDB_EXT_ATTRS];
                err = nla_parse_nested(nfea_tb, NFEA_MAX, attr,
                                       br_nda_fdb_pol, extack);
                if (err)
                        return err;
        } else {
                memset(nfea_tb, 0, sizeof(struct nlattr *) * (NFEA_MAX + 1));
        }

        if (vid) {
                v = br_vlan_find(vg, vid);
                if (!v || !br_vlan_should_use(v)) {
                        pr_info("bridge: RTM_NEWNEIGH with unconfigured vlan %d on %s\n", vid, dev->name);
                        return -EINVAL;
                }

                /* VID was specified, so use it. */
                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, vid, nfea_tb,
                                   notified, extack);
        } else {
                err = __br_fdb_add(ndm, br, p, addr, nlh_flags, 0, nfea_tb,
                                   notified, extack);
                if (err || !vg || !vg->num_vlans)
                        goto out;

                /* We have vlans configured on this port and user didn't
                 * specify a VLAN.  To be nice, add/update entry for every
                 * vlan on this port.
                 */
                list_for_each_entry(v, &vg->vlan_list, vlist) {
                        if (!br_vlan_should_use(v))
                                continue;
                        err = __br_fdb_add(ndm, br, p, addr, nlh_flags, v->vid,
                                           nfea_tb, notified, extack);
                        if (err)
                                goto out;
                }
        }

out:
        return err;
}

static int fdb_delete_by_addr_and_port(struct net_bridge *br,
                                       const struct net_bridge_port *p,
                                       const u8 *addr, u16 vlan, bool *notified)
{
        struct net_bridge_fdb_entry *fdb;

        fdb = br_fdb_find(br, addr, vlan);
        if (!fdb || READ_ONCE(fdb->dst) != p)
                return -ENOENT;

        fdb_delete(br, fdb, true);
        *notified = true;

        return 0;
}

static int __br_fdb_delete(struct net_bridge *br,
                           const struct net_bridge_port *p,
                           const unsigned char *addr, u16 vid, bool *notified)
{
        int err;

        spin_lock_bh(&br->hash_lock);
        err = fdb_delete_by_addr_and_port(br, p, addr, vid, notified);
        spin_unlock_bh(&br->hash_lock);

        return err;
}

/* Remove neighbor entry with RTM_DELNEIGH */
int br_fdb_delete(struct ndmsg *ndm, struct nlattr *tb[],
                  struct net_device *dev,
                  const unsigned char *addr, u16 vid, bool *notified,
                  struct netlink_ext_ack *extack)
{
        struct net_bridge_vlan_group *vg;
        struct net_bridge_port *p = NULL;
        struct net_bridge *br;
        int err;

        if (netif_is_bridge_master(dev)) {
                br = netdev_priv(dev);
                vg = br_vlan_group(br);
        } else {
                p = br_port_get_rtnl(dev);
                if (!p) {
                        pr_info("bridge: RTM_DELNEIGH %s not a bridge port\n",
                                dev->name);
                        return -EINVAL;
                }
                vg = nbp_vlan_group(p);
                br = p->br;
        }

        if (vid) {
                err = __br_fdb_delete(br, p, addr, vid, notified);
        } else {
                struct net_bridge_vlan *v;

                err = -ENOENT;
                err &= __br_fdb_delete(br, p, addr, 0, notified);
                if (!vg || !vg->num_vlans)
                        return err;

                list_for_each_entry(v, &vg->vlan_list, vlist) {
                        if (!br_vlan_should_use(v))
                                continue;
                        err &= __br_fdb_delete(br, p, addr, v->vid, notified);
                }
        }

        return err;
}

int br_fdb_sync_static(struct net_bridge *br, struct net_bridge_port *p)
{
        struct net_bridge_fdb_entry *f, *tmp;
        int err = 0;

        ASSERT_RTNL();

        /* the key here is that static entries change only under rtnl */
        rcu_read_lock();
        hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
                /* We only care for static entries */
                if (!test_bit(BR_FDB_STATIC, &f->flags))
                        continue;
                err = dev_uc_add(p->dev, f->key.addr.addr);
                if (err)
                        goto rollback;
        }
done:
        rcu_read_unlock();

        return err;

rollback:
        hlist_for_each_entry_rcu(tmp, &br->fdb_list, fdb_node) {
                /* We only care for static entries */
                if (!test_bit(BR_FDB_STATIC, &tmp->flags))
                        continue;
                if (tmp == f)
                        break;
                dev_uc_del(p->dev, tmp->key.addr.addr);
        }

        goto done;
}

void br_fdb_unsync_static(struct net_bridge *br, struct net_bridge_port *p)
{
        struct net_bridge_fdb_entry *f;

        ASSERT_RTNL();

        rcu_read_lock();
        hlist_for_each_entry_rcu(f, &br->fdb_list, fdb_node) {
                /* We only care for static entries */
                if (!test_bit(BR_FDB_STATIC, &f->flags))
                        continue;

                dev_uc_del(p->dev, f->key.addr.addr);
        }
        rcu_read_unlock();
}

int br_fdb_external_learn_add(struct net_bridge *br, struct net_bridge_port *p,
                              const unsigned char *addr, u16 vid, bool locked,
                              bool swdev_notify)
{
        struct net_bridge_fdb_entry *fdb;
        bool modified = false;
        int err = 0;

        trace_br_fdb_external_learn_add(br, p, addr, vid);

        if (locked && (!p || !(p->flags & BR_PORT_MAB)))
                return -EINVAL;

        spin_lock_bh(&br->hash_lock);

        fdb = br_fdb_find(br, addr, vid);
        if (!fdb) {
                unsigned long flags = BIT(BR_FDB_ADDED_BY_EXT_LEARN);

                if (swdev_notify)
                        flags |= BIT(BR_FDB_ADDED_BY_USER);

                if (!p)
                        flags |= BIT(BR_FDB_LOCAL);

                if (locked)
                        flags |= BIT(BR_FDB_LOCKED);

                fdb = fdb_create(br, p, addr, vid, flags);
                if (!fdb) {
                        err = -ENOMEM;
                        goto err_unlock;
                }
                fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
        } else {
                if (locked &&
                    (!test_bit(BR_FDB_LOCKED, &fdb->flags) ||
                     READ_ONCE(fdb->dst) != p)) {
                        err = -EINVAL;
                        goto err_unlock;
                }

                WRITE_ONCE(fdb->updated, jiffies);

                if (READ_ONCE(fdb->dst) != p) {
                        WRITE_ONCE(fdb->dst, p);
                        modified = true;
                }

                if (test_and_set_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags)) {
                        /* Refresh entry */
                        WRITE_ONCE(fdb->used, jiffies);
                } else {
                        modified = true;
                }

                if (locked != test_bit(BR_FDB_LOCKED, &fdb->flags)) {
                        change_bit(BR_FDB_LOCKED, &fdb->flags);
                        modified = true;
                }

                if (swdev_notify)
                        set_bit(BR_FDB_ADDED_BY_USER, &fdb->flags);

                if (!p)
                        set_bit(BR_FDB_LOCAL, &fdb->flags);

                if ((swdev_notify || !p) &&
                    test_and_clear_bit(BR_FDB_DYNAMIC_LEARNED, &fdb->flags))
                        atomic_dec(&br->fdb_n_learned);

                if (modified)
                        fdb_notify(br, fdb, RTM_NEWNEIGH, swdev_notify);
        }

err_unlock:
        spin_unlock_bh(&br->hash_lock);

        return err;
}

int br_fdb_external_learn_del(struct net_bridge *br, struct net_bridge_port *p,
                              const unsigned char *addr, u16 vid,
                              bool swdev_notify)
{
        struct net_bridge_fdb_entry *fdb;
        int err = 0;

        spin_lock_bh(&br->hash_lock);

        fdb = br_fdb_find(br, addr, vid);
        if (fdb && test_bit(BR_FDB_ADDED_BY_EXT_LEARN, &fdb->flags))
                fdb_delete(br, fdb, swdev_notify);
        else
                err = -ENOENT;

        spin_unlock_bh(&br->hash_lock);

        return err;
}

void br_fdb_offloaded_set(struct net_bridge *br, struct net_bridge_port *p,
                          const unsigned char *addr, u16 vid, bool offloaded)
{
        struct net_bridge_fdb_entry *fdb;

        spin_lock_bh(&br->hash_lock);

        fdb = br_fdb_find(br, addr, vid);
        if (fdb && offloaded != test_bit(BR_FDB_OFFLOADED, &fdb->flags))
                change_bit(BR_FDB_OFFLOADED, &fdb->flags);

        spin_unlock_bh(&br->hash_lock);
}

void br_fdb_clear_offload(const struct net_device *dev, u16 vid)
{
        struct net_bridge_fdb_entry *f;
        struct net_bridge_port *p;

        ASSERT_RTNL();

        p = br_port_get_rtnl(dev);
        if (!p)
                return;

        spin_lock_bh(&p->br->hash_lock);
        hlist_for_each_entry(f, &p->br->fdb_list, fdb_node) {
                if (f->dst == p && f->key.vlan_id == vid)
                        clear_bit(BR_FDB_OFFLOADED, &f->flags);
        }
        spin_unlock_bh(&p->br->hash_lock);
}
EXPORT_SYMBOL_GPL(br_fdb_clear_offload);