// SPDX-License-Identifier: GPL-2.0-or-later
/* Copyright (c) 2014 Mahesh Bandewar <maheshb@google.com>
 */

#include <linux/ethtool.h>
#include <net/netdev_lock.h>

#include "ipvlan.h"

static int ipvlan_set_port_mode(struct ipvl_port *port, u16 nval,
                                struct netlink_ext_ack *extack)
{
        struct ipvl_dev *ipvlan;
        unsigned int flags;
        int err;

        ASSERT_RTNL();
        if (port->mode != nval) {
                list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
                        flags = ipvlan->dev->flags;
                        if (nval == IPVLAN_MODE_L3 || nval == IPVLAN_MODE_L3S) {
                                err = dev_change_flags(ipvlan->dev,
                                                       flags | IFF_NOARP,
                                                       extack);
                        } else {
                                err = dev_change_flags(ipvlan->dev,
                                                       flags & ~IFF_NOARP,
                                                       extack);
                        }
                        if (unlikely(err))
                                goto fail;
                }
                if (nval == IPVLAN_MODE_L3S) {
                        /* New mode is L3S */
                        err = ipvlan_l3s_register(port);
                        if (err)
                                goto fail;
                } else if (port->mode == IPVLAN_MODE_L3S) {
                        /* Old mode was L3S */
                        ipvlan_l3s_unregister(port);
                }
                port->mode = nval;
        }
        return 0;

fail:
        /* Undo the flags changes that have been done so far. */
        list_for_each_entry_continue_reverse(ipvlan, &port->ipvlans, pnode) {
                flags = ipvlan->dev->flags;
                if (port->mode == IPVLAN_MODE_L3 ||
                    port->mode == IPVLAN_MODE_L3S)
                        dev_change_flags(ipvlan->dev, flags | IFF_NOARP,
                                         NULL);
                else
                        dev_change_flags(ipvlan->dev, flags & ~IFF_NOARP,
                                         NULL);
        }

        return err;
}

static int ipvlan_port_create(struct net_device *dev)
{
        struct ipvl_port *port;
        int err, idx;

        port = kzalloc_obj(struct ipvl_port);
        if (!port)
                return -ENOMEM;

        write_pnet(&port->pnet, dev_net(dev));
        port->dev = dev;
        port->mode = IPVLAN_MODE_L3;
        INIT_LIST_HEAD(&port->ipvlans);
        for (idx = 0; idx < IPVLAN_HASH_SIZE; idx++)
                INIT_HLIST_HEAD(&port->hlhead[idx]);

        spin_lock_init(&port->addrs_lock);
        skb_queue_head_init(&port->backlog);
        INIT_WORK(&port->wq, ipvlan_process_multicast);
        ida_init(&port->ida);
        port->dev_id_start = 1;

        err = netdev_rx_handler_register(dev, ipvlan_handle_frame, port);
        if (err)
                goto err;

        netdev_hold(dev, &port->dev_tracker, GFP_KERNEL);
        return 0;

err:
        kfree(port);
        return err;
}

static void ipvlan_port_destroy(struct net_device *dev)
{
        struct ipvl_port *port = ipvlan_port_get_rtnl(dev);
        struct sk_buff *skb;

        netdev_put(dev, &port->dev_tracker);
        if (port->mode == IPVLAN_MODE_L3S)
                ipvlan_l3s_unregister(port);
        netdev_rx_handler_unregister(dev);
        cancel_work_sync(&port->wq);
        while ((skb = __skb_dequeue(&port->backlog)) != NULL) {
                dev_put(skb->dev);
                kfree_skb(skb);
        }
        ida_destroy(&port->ida);
        kfree(port);
}

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

#define IPVLAN_ALWAYS_ON \
        (IPVLAN_ALWAYS_ON_OFLOADS | NETIF_F_VLAN_CHALLENGED)

#define IPVLAN_FEATURES \
        (NETIF_F_SG | NETIF_F_HW_CSUM | NETIF_F_HIGHDMA | NETIF_F_FRAGLIST | \
         NETIF_F_GSO | NETIF_F_ALL_TSO | NETIF_F_GSO_ROBUST | \
         NETIF_F_GRO | NETIF_F_RXCSUM | \
         NETIF_F_HW_VLAN_CTAG_FILTER | NETIF_F_HW_VLAN_STAG_FILTER)

        /* NETIF_F_GSO_ENCAP_ALL NETIF_F_GSO_SOFTWARE Newly added */

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

static int ipvlan_init(struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;
        struct ipvl_port *port;
        int err;

        dev->state = (dev->state & ~IPVLAN_STATE_MASK) |
                     (phy_dev->state & IPVLAN_STATE_MASK);
        dev->features = phy_dev->features & IPVLAN_FEATURES;
        dev->features |= IPVLAN_ALWAYS_ON;
        dev->vlan_features = phy_dev->vlan_features & IPVLAN_FEATURES;
        dev->vlan_features |= IPVLAN_ALWAYS_ON_OFLOADS;
        dev->hw_enc_features |= dev->features;
        dev->lltx = true;
        netif_inherit_tso_max(dev, phy_dev);
        dev->hard_header_len = phy_dev->hard_header_len;

        netdev_lockdep_set_classes(dev);

        ipvlan->pcpu_stats = netdev_alloc_pcpu_stats(struct ipvl_pcpu_stats);
        if (!ipvlan->pcpu_stats)
                return -ENOMEM;

        if (!netif_is_ipvlan_port(phy_dev)) {
                err = ipvlan_port_create(phy_dev);
                if (err < 0) {
                        free_percpu(ipvlan->pcpu_stats);
                        return err;
                }
        }
        port = ipvlan_port_get_rtnl(phy_dev);
        port->count += 1;
        return 0;
}

static void ipvlan_uninit(struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;
        struct ipvl_port *port;

        free_percpu(ipvlan->pcpu_stats);

        port = ipvlan_port_get_rtnl(phy_dev);
        port->count -= 1;
        if (!port->count)
                ipvlan_port_destroy(port->dev);
}

static int ipvlan_open(struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct ipvl_port *port = ipvlan->port;
        struct ipvl_addr *addr;

        if (ipvlan->port->mode == IPVLAN_MODE_L3 ||
            ipvlan->port->mode == IPVLAN_MODE_L3S)
                dev->flags |= IFF_NOARP;
        else
                dev->flags &= ~IFF_NOARP;

        spin_lock_bh(&port->addrs_lock);
        list_for_each_entry(addr, &ipvlan->addrs, anode)
                ipvlan_ht_addr_add(ipvlan, addr);
        spin_unlock_bh(&port->addrs_lock);

        return 0;
}

static int ipvlan_stop(struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;
        struct ipvl_addr *addr;

        dev_uc_unsync(phy_dev, dev);
        dev_mc_unsync(phy_dev, dev);

        spin_lock_bh(&ipvlan->port->addrs_lock);
        list_for_each_entry(addr, &ipvlan->addrs, anode)
                ipvlan_ht_addr_del(addr);
        spin_unlock_bh(&ipvlan->port->addrs_lock);

        return 0;
}

static netdev_tx_t ipvlan_start_xmit(struct sk_buff *skb,
                                     struct net_device *dev)
{
        const struct ipvl_dev *ipvlan = netdev_priv(dev);
        int skblen = skb->len;
        int ret;

        ret = ipvlan_queue_xmit(skb, dev);
        if (likely(ret == NET_XMIT_SUCCESS || ret == NET_XMIT_CN)) {
                struct ipvl_pcpu_stats *pcptr;

                pcptr = this_cpu_ptr(ipvlan->pcpu_stats);

                u64_stats_update_begin(&pcptr->syncp);
                u64_stats_inc(&pcptr->tx_pkts);
                u64_stats_add(&pcptr->tx_bytes, skblen);
                u64_stats_update_end(&pcptr->syncp);
        } else {
                this_cpu_inc(ipvlan->pcpu_stats->tx_drps);
        }
        return ret;
}

static netdev_features_t ipvlan_fix_features(struct net_device *dev,
                                             netdev_features_t features)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        features |= NETIF_F_ALL_FOR_ALL;
        features &= (ipvlan->sfeatures | ~IPVLAN_FEATURES);
        features = netdev_increment_features(ipvlan->phy_dev->features,
                                             features, features);
        features |= IPVLAN_ALWAYS_ON;
        features &= (IPVLAN_FEATURES | IPVLAN_ALWAYS_ON);

        return features;
}

static void ipvlan_change_rx_flags(struct net_device *dev, int change)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;

        if (change & IFF_ALLMULTI)
                dev_set_allmulti(phy_dev, dev->flags & IFF_ALLMULTI? 1 : -1);
}

static void ipvlan_set_multicast_mac_filter(struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        if (dev->flags & (IFF_PROMISC | IFF_ALLMULTI)) {
                bitmap_fill(ipvlan->mac_filters, IPVLAN_MAC_FILTER_SIZE);
        } else {
                struct netdev_hw_addr *ha;
                DECLARE_BITMAP(mc_filters, IPVLAN_MAC_FILTER_SIZE);

                bitmap_zero(mc_filters, IPVLAN_MAC_FILTER_SIZE);
                netdev_for_each_mc_addr(ha, dev)
                        __set_bit(ipvlan_mac_hash(ha->addr), mc_filters);

                /* Turn-on broadcast bit irrespective of address family,
                 * since broadcast is deferred to a work-queue, hence no
                 * impact on fast-path processing.
                 */
                __set_bit(ipvlan_mac_hash(dev->broadcast), mc_filters);

                bitmap_copy(ipvlan->mac_filters, mc_filters,
                            IPVLAN_MAC_FILTER_SIZE);
        }
        dev_uc_sync(ipvlan->phy_dev, dev);
        dev_mc_sync(ipvlan->phy_dev, dev);
}

static void ipvlan_get_stats64(struct net_device *dev,
                               struct rtnl_link_stats64 *s)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        if (ipvlan->pcpu_stats) {
                struct ipvl_pcpu_stats *pcptr;
                u64 rx_pkts, rx_bytes, rx_mcast, tx_pkts, tx_bytes;
                u32 rx_errs = 0, tx_drps = 0;
                u32 strt;
                int idx;

                for_each_possible_cpu(idx) {
                        pcptr = per_cpu_ptr(ipvlan->pcpu_stats, idx);
                        do {
                                strt = u64_stats_fetch_begin(&pcptr->syncp);
                                rx_pkts = u64_stats_read(&pcptr->rx_pkts);
                                rx_bytes = u64_stats_read(&pcptr->rx_bytes);
                                rx_mcast = u64_stats_read(&pcptr->rx_mcast);
                                tx_pkts = u64_stats_read(&pcptr->tx_pkts);
                                tx_bytes = u64_stats_read(&pcptr->tx_bytes);
                        } while (u64_stats_fetch_retry(&pcptr->syncp,
                                                           strt));

                        s->rx_packets += rx_pkts;
                        s->rx_bytes += rx_bytes;
                        s->multicast += rx_mcast;
                        s->tx_packets += tx_pkts;
                        s->tx_bytes += tx_bytes;

                        /* u32 values are updated without syncp protection. */
                        rx_errs += READ_ONCE(pcptr->rx_errs);
                        tx_drps += READ_ONCE(pcptr->tx_drps);
                }
                s->rx_errors = rx_errs;
                s->rx_dropped = rx_errs;
                s->tx_dropped = tx_drps;
        }
        s->tx_errors = DEV_STATS_READ(dev, tx_errors);
}

static int ipvlan_vlan_rx_add_vid(struct net_device *dev, __be16 proto, u16 vid)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;

        return vlan_vid_add(phy_dev, proto, vid);
}

static int ipvlan_vlan_rx_kill_vid(struct net_device *dev, __be16 proto,
                                   u16 vid)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;

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

static int ipvlan_get_iflink(const struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        return READ_ONCE(ipvlan->phy_dev->ifindex);
}

static const struct net_device_ops ipvlan_netdev_ops = {
        .ndo_init               = ipvlan_init,
        .ndo_uninit             = ipvlan_uninit,
        .ndo_open               = ipvlan_open,
        .ndo_stop               = ipvlan_stop,
        .ndo_start_xmit         = ipvlan_start_xmit,
        .ndo_fix_features       = ipvlan_fix_features,
        .ndo_change_rx_flags    = ipvlan_change_rx_flags,
        .ndo_set_rx_mode        = ipvlan_set_multicast_mac_filter,
        .ndo_get_stats64        = ipvlan_get_stats64,
        .ndo_vlan_rx_add_vid    = ipvlan_vlan_rx_add_vid,
        .ndo_vlan_rx_kill_vid   = ipvlan_vlan_rx_kill_vid,
        .ndo_get_iflink         = ipvlan_get_iflink,
};

static int ipvlan_hard_header(struct sk_buff *skb, struct net_device *dev,
                              unsigned short type, const void *daddr,
                              const void *saddr, unsigned len)
{
        const struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct net_device *phy_dev = ipvlan->phy_dev;

        /* TODO Probably use a different field than dev_addr so that the
         * mac-address on the virtual device is portable and can be carried
         * while the packets use the mac-addr on the physical device.
         */
        return dev_hard_header(skb, phy_dev, type, daddr,
                               saddr ? : phy_dev->dev_addr, len);
}

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

static void ipvlan_adjust_mtu(struct ipvl_dev *ipvlan, struct net_device *dev)
{
        ipvlan->dev->mtu = dev->mtu;
}

static bool netif_is_ipvlan(const struct net_device *dev)
{
        /* both ipvlan and ipvtap devices use the same netdev_ops */
        return dev->netdev_ops == &ipvlan_netdev_ops;
}

static int ipvlan_ethtool_get_link_ksettings(struct net_device *dev,
                                             struct ethtool_link_ksettings *cmd)
{
        const struct ipvl_dev *ipvlan = netdev_priv(dev);

        return __ethtool_get_link_ksettings(ipvlan->phy_dev, cmd);
}

static void ipvlan_ethtool_get_drvinfo(struct net_device *dev,
                                       struct ethtool_drvinfo *drvinfo)
{
        strscpy(drvinfo->driver, IPVLAN_DRV, sizeof(drvinfo->driver));
        strscpy(drvinfo->version, IPV_DRV_VER, sizeof(drvinfo->version));
}

static u32 ipvlan_ethtool_get_msglevel(struct net_device *dev)
{
        const struct ipvl_dev *ipvlan = netdev_priv(dev);

        return ipvlan->msg_enable;
}

static void ipvlan_ethtool_set_msglevel(struct net_device *dev, u32 value)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        ipvlan->msg_enable = value;
}

static const struct ethtool_ops ipvlan_ethtool_ops = {
        .get_link       = ethtool_op_get_link,
        .get_link_ksettings     = ipvlan_ethtool_get_link_ksettings,
        .get_drvinfo    = ipvlan_ethtool_get_drvinfo,
        .get_msglevel   = ipvlan_ethtool_get_msglevel,
        .set_msglevel   = ipvlan_ethtool_set_msglevel,
};

static int ipvlan_nl_changelink(struct net_device *dev,
                                struct nlattr *tb[], struct nlattr *data[],
                                struct netlink_ext_ack *extack)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct ipvl_port *port = ipvlan_port_get_rtnl(ipvlan->phy_dev);
        int err = 0;

        if (!data)
                return 0;
        if (!ns_capable(dev_net(ipvlan->phy_dev)->user_ns, CAP_NET_ADMIN))
                return -EPERM;

        if (data[IFLA_IPVLAN_MODE]) {
                u16 nmode = nla_get_u16(data[IFLA_IPVLAN_MODE]);

                err = ipvlan_set_port_mode(port, nmode, extack);
        }

        if (!err && data[IFLA_IPVLAN_FLAGS]) {
                u16 flags = nla_get_u16(data[IFLA_IPVLAN_FLAGS]);

                if (flags & IPVLAN_F_PRIVATE)
                        ipvlan_mark_private(port);
                else
                        ipvlan_clear_private(port);

                if (flags & IPVLAN_F_VEPA)
                        ipvlan_mark_vepa(port);
                else
                        ipvlan_clear_vepa(port);
        }

        return err;
}

static size_t ipvlan_nl_getsize(const struct net_device *dev)
{
        return (0
                + nla_total_size(2) /* IFLA_IPVLAN_MODE */
                + nla_total_size(2) /* IFLA_IPVLAN_FLAGS */
                );
}

static int ipvlan_nl_validate(struct nlattr *tb[], struct nlattr *data[],
                              struct netlink_ext_ack *extack)
{
        if (!data)
                return 0;

        if (data[IFLA_IPVLAN_MODE]) {
                u16 mode = nla_get_u16(data[IFLA_IPVLAN_MODE]);

                if (mode >= IPVLAN_MODE_MAX)
                        return -EINVAL;
        }
        if (data[IFLA_IPVLAN_FLAGS]) {
                u16 flags = nla_get_u16(data[IFLA_IPVLAN_FLAGS]);

                /* Only two bits are used at this moment. */
                if (flags & ~(IPVLAN_F_PRIVATE | IPVLAN_F_VEPA))
                        return -EINVAL;
                /* Also both flags can't be active at the same time. */
                if ((flags & (IPVLAN_F_PRIVATE | IPVLAN_F_VEPA)) ==
                    (IPVLAN_F_PRIVATE | IPVLAN_F_VEPA))
                        return -EINVAL;
        }

        return 0;
}

static int ipvlan_nl_fillinfo(struct sk_buff *skb,
                              const struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct ipvl_port *port = ipvlan_port_get_rtnl(ipvlan->phy_dev);
        int ret = -EINVAL;

        if (!port)
                goto err;

        ret = -EMSGSIZE;
        if (nla_put_u16(skb, IFLA_IPVLAN_MODE, port->mode))
                goto err;
        if (nla_put_u16(skb, IFLA_IPVLAN_FLAGS, port->flags))
                goto err;

        return 0;

err:
        return ret;
}

int ipvlan_link_new(struct net_device *dev, struct rtnl_newlink_params *params,
                    struct netlink_ext_ack *extack)
{
        struct net *link_net = rtnl_newlink_link_net(params);
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct nlattr **data = params->data;
        struct nlattr **tb = params->tb;
        struct ipvl_port *port;
        struct net_device *phy_dev;
        int err;
        u16 mode = IPVLAN_MODE_L3;

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

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

        if (netif_is_ipvlan(phy_dev)) {
                struct ipvl_dev *tmp = netdev_priv(phy_dev);

                phy_dev = tmp->phy_dev;
                if (!ns_capable(dev_net(phy_dev)->user_ns, CAP_NET_ADMIN))
                        return -EPERM;
        } else if (!netif_is_ipvlan_port(phy_dev)) {
                /* Exit early if the underlying link is invalid or busy */
                if (phy_dev->type != ARPHRD_ETHER ||
                    phy_dev->flags & IFF_LOOPBACK) {
                        netdev_err(phy_dev,
                                   "Master is either lo or non-ether device\n");
                        return -EINVAL;
                }

                if (netdev_is_rx_handler_busy(phy_dev)) {
                        netdev_err(phy_dev, "Device is already in use.\n");
                        return -EBUSY;
                }
        }

        ipvlan->phy_dev = phy_dev;
        ipvlan->dev = dev;
        ipvlan->sfeatures = IPVLAN_FEATURES;
        if (!tb[IFLA_MTU])
                ipvlan_adjust_mtu(ipvlan, phy_dev);
        INIT_LIST_HEAD(&ipvlan->addrs);

        /* TODO Probably put random address here to be presented to the
         * world but keep using the physical-dev address for the outgoing
         * packets.
         */
        eth_hw_addr_set(dev, phy_dev->dev_addr);

        dev->priv_flags |= IFF_NO_RX_HANDLER;

        err = register_netdevice(dev);
        if (err < 0)
                return err;

        /* ipvlan_init() would have created the port, if required */
        port = ipvlan_port_get_rtnl(phy_dev);
        ipvlan->port = port;

        /* If the port-id base is at the MAX value, then wrap it around and
         * begin from 0x1 again. This may be due to a busy system where lots
         * of slaves are getting created and deleted.
         */
        if (port->dev_id_start == 0xFFFE)
                port->dev_id_start = 0x1;

        /* Since L2 address is shared among all IPvlan slaves including
         * master, use unique 16 bit dev-ids to differentiate among them.
         * Assign IDs between 0x1 and 0xFFFE (used by the master) to each
         * slave link [see addrconf_ifid_eui48()].
         */
        err = ida_alloc_range(&port->ida, port->dev_id_start, 0xFFFD,
                              GFP_KERNEL);
        if (err < 0)
                err = ida_alloc_range(&port->ida, 0x1, port->dev_id_start - 1,
                                      GFP_KERNEL);
        if (err < 0)
                goto unregister_netdev;
        dev->dev_id = err;

        /* Increment id-base to the next slot for the future assignment */
        port->dev_id_start = err + 1;

        err = netdev_upper_dev_link(phy_dev, dev, extack);
        if (err)
                goto remove_ida;

        /* Flags are per port and latest update overrides. User has
         * to be consistent in setting it just like the mode attribute.
         */
        if (data && data[IFLA_IPVLAN_FLAGS])
                port->flags = nla_get_u16(data[IFLA_IPVLAN_FLAGS]);

        if (data && data[IFLA_IPVLAN_MODE])
                mode = nla_get_u16(data[IFLA_IPVLAN_MODE]);

        err = ipvlan_set_port_mode(port, mode, extack);
        if (err)
                goto unlink_netdev;

        list_add_tail_rcu(&ipvlan->pnode, &port->ipvlans);
        netif_stacked_transfer_operstate(phy_dev, dev);
        return 0;

unlink_netdev:
        netdev_upper_dev_unlink(phy_dev, dev);
remove_ida:
        ida_free(&port->ida, dev->dev_id);
unregister_netdev:
        unregister_netdevice(dev);
        return err;
}
EXPORT_SYMBOL_GPL(ipvlan_link_new);

void ipvlan_link_delete(struct net_device *dev, struct list_head *head)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct ipvl_addr *addr, *next;

        spin_lock_bh(&ipvlan->port->addrs_lock);
        list_for_each_entry_safe(addr, next, &ipvlan->addrs, anode) {
                ipvlan_ht_addr_del(addr);
                list_del_rcu(&addr->anode);
                kfree_rcu(addr, rcu);
        }
        spin_unlock_bh(&ipvlan->port->addrs_lock);

        ida_free(&ipvlan->port->ida, dev->dev_id);
        list_del_rcu(&ipvlan->pnode);
        unregister_netdevice_queue(dev, head);
        netdev_upper_dev_unlink(ipvlan->phy_dev, dev);
}
EXPORT_SYMBOL_GPL(ipvlan_link_delete);

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

        dev->max_mtu = ETH_MAX_MTU;
        dev->priv_flags &= ~(IFF_XMIT_DST_RELEASE | IFF_TX_SKB_SHARING);
        dev->priv_flags |= IFF_UNICAST_FLT | IFF_NO_QUEUE;
        dev->netdev_ops = &ipvlan_netdev_ops;
        dev->needs_free_netdev = true;
        dev->header_ops = &ipvlan_header_ops;
        dev->ethtool_ops = &ipvlan_ethtool_ops;
}
EXPORT_SYMBOL_GPL(ipvlan_link_setup);

static const struct nla_policy ipvlan_nl_policy[IFLA_IPVLAN_MAX + 1] =
{
        [IFLA_IPVLAN_MODE] = { .type = NLA_U16 },
        [IFLA_IPVLAN_FLAGS] = { .type = NLA_U16 },
};

static struct net *ipvlan_get_link_net(const struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        return dev_net(ipvlan->phy_dev);
}

static struct rtnl_link_ops ipvlan_link_ops = {
        .kind           = "ipvlan",
        .priv_size      = sizeof(struct ipvl_dev),

        .setup          = ipvlan_link_setup,
        .newlink        = ipvlan_link_new,
        .dellink        = ipvlan_link_delete,
        .get_link_net   = ipvlan_get_link_net,
};

int ipvlan_link_register(struct rtnl_link_ops *ops)
{
        ops->get_size   = ipvlan_nl_getsize;
        ops->policy     = ipvlan_nl_policy;
        ops->validate   = ipvlan_nl_validate;
        ops->fill_info  = ipvlan_nl_fillinfo;
        ops->changelink = ipvlan_nl_changelink;
        ops->maxtype    = IFLA_IPVLAN_MAX;
        return rtnl_link_register(ops);
}
EXPORT_SYMBOL_GPL(ipvlan_link_register);

static int ipvlan_device_event(struct notifier_block *unused,
                               unsigned long event, void *ptr)
{
        struct netlink_ext_ack *extack = netdev_notifier_info_to_extack(ptr);
        struct netdev_notifier_pre_changeaddr_info *prechaddr_info;
        struct net_device *dev = netdev_notifier_info_to_dev(ptr);
        struct ipvl_dev *ipvlan, *next;
        struct ipvl_port *port;
        LIST_HEAD(lst_kill);
        int err;

        if (!netif_is_ipvlan_port(dev))
                return NOTIFY_DONE;

        port = ipvlan_port_get_rtnl(dev);

        switch (event) {
        case NETDEV_UP:
        case NETDEV_DOWN:
        case NETDEV_CHANGE:
                list_for_each_entry(ipvlan, &port->ipvlans, pnode)
                        netif_stacked_transfer_operstate(ipvlan->phy_dev,
                                                         ipvlan->dev);
                break;

        case NETDEV_REGISTER: {
                struct net *oldnet, *newnet = dev_net(dev);

                oldnet = read_pnet(&port->pnet);
                if (net_eq(newnet, oldnet))
                        break;

                write_pnet(&port->pnet, newnet);

                if (port->mode == IPVLAN_MODE_L3S)
                        ipvlan_migrate_l3s_hook(oldnet, newnet);
                break;
        }
        case NETDEV_UNREGISTER:
                if (dev->reg_state != NETREG_UNREGISTERING)
                        break;

                list_for_each_entry_safe(ipvlan, next, &port->ipvlans, pnode)
                        ipvlan->dev->rtnl_link_ops->dellink(ipvlan->dev,
                                                            &lst_kill);
                unregister_netdevice_many(&lst_kill);
                break;

        case NETDEV_FEAT_CHANGE:
                list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
                        netif_inherit_tso_max(ipvlan->dev, dev);
                        netdev_update_features(ipvlan->dev);
                }
                break;

        case NETDEV_CHANGEMTU:
                list_for_each_entry(ipvlan, &port->ipvlans, pnode)
                        ipvlan_adjust_mtu(ipvlan, dev);
                break;

        case NETDEV_PRE_CHANGEADDR:
                prechaddr_info = ptr;
                list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
                        err = netif_pre_changeaddr_notify(ipvlan->dev,
                                                          prechaddr_info->dev_addr,
                                                          extack);
                        if (err)
                                return notifier_from_errno(err);
                }
                break;

        case NETDEV_CHANGEADDR:
                list_for_each_entry(ipvlan, &port->ipvlans, pnode) {
                        eth_hw_addr_set(ipvlan->dev, dev->dev_addr);
                        call_netdevice_notifiers(NETDEV_CHANGEADDR, ipvlan->dev);
                }
                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:
                list_for_each_entry(ipvlan, &port->ipvlans, pnode)
                        call_netdevice_notifiers(event, ipvlan->dev);
        }
        return NOTIFY_DONE;
}

/* the caller must held the addrs lock */
static int ipvlan_add_addr(struct ipvl_dev *ipvlan, void *iaddr, bool is_v6)
{
        struct ipvl_addr *addr;

        assert_spin_locked(&ipvlan->port->addrs_lock);

        addr = kzalloc_obj(struct ipvl_addr, GFP_ATOMIC);
        if (!addr)
                return -ENOMEM;

        addr->master = ipvlan;
        if (!is_v6) {
                memcpy(&addr->ip4addr, iaddr, sizeof(struct in_addr));
                addr->atype = IPVL_IPV4;
#if IS_ENABLED(CONFIG_IPV6)
        } else {
                memcpy(&addr->ip6addr, iaddr, sizeof(struct in6_addr));
                addr->atype = IPVL_IPV6;
#endif
        }

        list_add_tail_rcu(&addr->anode, &ipvlan->addrs);

        /* If the interface is not up, the address will be added to the hash
         * list by ipvlan_open.
         */
        if (netif_running(ipvlan->dev))
                ipvlan_ht_addr_add(ipvlan, addr);

        return 0;
}

static void ipvlan_del_addr(struct ipvl_dev *ipvlan, void *iaddr, bool is_v6)
{
        struct ipvl_addr *addr;

        spin_lock_bh(&ipvlan->port->addrs_lock);
        addr = ipvlan_find_addr(ipvlan, iaddr, is_v6);
        if (!addr) {
                spin_unlock_bh(&ipvlan->port->addrs_lock);
                return;
        }

        ipvlan_ht_addr_del(addr);
        list_del_rcu(&addr->anode);
        spin_unlock_bh(&ipvlan->port->addrs_lock);
        kfree_rcu(addr, rcu);
}

static bool ipvlan_is_valid_dev(const struct net_device *dev)
{
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        if (!netif_is_ipvlan(dev))
                return false;

        if (!ipvlan || !ipvlan->port)
                return false;

        return true;
}

#if IS_ENABLED(CONFIG_IPV6)
static int ipvlan_add_addr6(struct ipvl_dev *ipvlan, struct in6_addr *ip6_addr)
{
        int ret = -EINVAL;

        spin_lock_bh(&ipvlan->port->addrs_lock);
        if (ipvlan_addr_busy(ipvlan->port, ip6_addr, true))
                netif_err(ipvlan, ifup, ipvlan->dev,
                          "Failed to add IPv6=%pI6c addr for %s intf\n",
                          ip6_addr, ipvlan->dev->name);
        else
                ret = ipvlan_add_addr(ipvlan, ip6_addr, true);
        spin_unlock_bh(&ipvlan->port->addrs_lock);
        return ret;
}

static void ipvlan_del_addr6(struct ipvl_dev *ipvlan, struct in6_addr *ip6_addr)
{
        return ipvlan_del_addr(ipvlan, ip6_addr, true);
}

static int ipvlan_addr6_event(struct notifier_block *unused,
                              unsigned long event, void *ptr)
{
        struct inet6_ifaddr *if6 = (struct inet6_ifaddr *)ptr;
        struct net_device *dev = (struct net_device *)if6->idev->dev;
        struct ipvl_dev *ipvlan = netdev_priv(dev);

        if (!ipvlan_is_valid_dev(dev))
                return NOTIFY_DONE;

        switch (event) {
        case NETDEV_UP:
                if (ipvlan_add_addr6(ipvlan, &if6->addr))
                        return NOTIFY_BAD;
                break;

        case NETDEV_DOWN:
                ipvlan_del_addr6(ipvlan, &if6->addr);
                break;
        }

        return NOTIFY_OK;
}

static int ipvlan_addr6_validator_event(struct notifier_block *unused,
                                        unsigned long event, void *ptr)
{
        struct in6_validator_info *i6vi = (struct in6_validator_info *)ptr;
        struct net_device *dev = (struct net_device *)i6vi->i6vi_dev->dev;
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        int ret = NOTIFY_OK;

        if (!ipvlan_is_valid_dev(dev))
                return NOTIFY_DONE;

        switch (event) {
        case NETDEV_UP:
                spin_lock_bh(&ipvlan->port->addrs_lock);
                if (ipvlan_addr_busy(ipvlan->port, &i6vi->i6vi_addr, true)) {
                        NL_SET_ERR_MSG(i6vi->extack,
                                       "Address already assigned to an ipvlan device");
                        ret = notifier_from_errno(-EADDRINUSE);
                }
                spin_unlock_bh(&ipvlan->port->addrs_lock);
                break;
        }

        return ret;
}
#endif

static int ipvlan_add_addr4(struct ipvl_dev *ipvlan, struct in_addr *ip4_addr)
{
        int ret = -EINVAL;

        spin_lock_bh(&ipvlan->port->addrs_lock);
        if (ipvlan_addr_busy(ipvlan->port, ip4_addr, false))
                netif_err(ipvlan, ifup, ipvlan->dev,
                          "Failed to add IPv4=%pI4 on %s intf.\n",
                          ip4_addr, ipvlan->dev->name);
        else
                ret = ipvlan_add_addr(ipvlan, ip4_addr, false);
        spin_unlock_bh(&ipvlan->port->addrs_lock);
        return ret;
}

static void ipvlan_del_addr4(struct ipvl_dev *ipvlan, struct in_addr *ip4_addr)
{
        return ipvlan_del_addr(ipvlan, ip4_addr, false);
}

static int ipvlan_addr4_event(struct notifier_block *unused,
                              unsigned long event, void *ptr)
{
        struct in_ifaddr *if4 = (struct in_ifaddr *)ptr;
        struct net_device *dev = (struct net_device *)if4->ifa_dev->dev;
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        struct in_addr ip4_addr;

        if (!ipvlan_is_valid_dev(dev))
                return NOTIFY_DONE;

        switch (event) {
        case NETDEV_UP:
                ip4_addr.s_addr = if4->ifa_address;
                if (ipvlan_add_addr4(ipvlan, &ip4_addr))
                        return NOTIFY_BAD;
                break;

        case NETDEV_DOWN:
                ip4_addr.s_addr = if4->ifa_address;
                ipvlan_del_addr4(ipvlan, &ip4_addr);
                break;
        }

        return NOTIFY_OK;
}

static int ipvlan_addr4_validator_event(struct notifier_block *unused,
                                        unsigned long event, void *ptr)
{
        struct in_validator_info *ivi = (struct in_validator_info *)ptr;
        struct net_device *dev = (struct net_device *)ivi->ivi_dev->dev;
        struct ipvl_dev *ipvlan = netdev_priv(dev);
        int ret = NOTIFY_OK;

        if (!ipvlan_is_valid_dev(dev))
                return NOTIFY_DONE;

        switch (event) {
        case NETDEV_UP:
                spin_lock_bh(&ipvlan->port->addrs_lock);
                if (ipvlan_addr_busy(ipvlan->port, &ivi->ivi_addr, false)) {
                        NL_SET_ERR_MSG(ivi->extack,
                                       "Address already assigned to an ipvlan device");
                        ret = notifier_from_errno(-EADDRINUSE);
                }
                spin_unlock_bh(&ipvlan->port->addrs_lock);
                break;
        }

        return ret;
}

static struct notifier_block ipvlan_addr4_notifier_block __read_mostly = {
        .notifier_call = ipvlan_addr4_event,
};

static struct notifier_block ipvlan_addr4_vtor_notifier_block __read_mostly = {
        .notifier_call = ipvlan_addr4_validator_event,
};

static struct notifier_block ipvlan_notifier_block __read_mostly = {
        .notifier_call = ipvlan_device_event,
};

#if IS_ENABLED(CONFIG_IPV6)
static struct notifier_block ipvlan_addr6_notifier_block __read_mostly = {
        .notifier_call = ipvlan_addr6_event,
};

static struct notifier_block ipvlan_addr6_vtor_notifier_block __read_mostly = {
        .notifier_call = ipvlan_addr6_validator_event,
};
#endif

static int __init ipvlan_init_module(void)
{
        int err;

        ipvlan_init_secret();
        register_netdevice_notifier(&ipvlan_notifier_block);
#if IS_ENABLED(CONFIG_IPV6)
        register_inet6addr_notifier(&ipvlan_addr6_notifier_block);
        register_inet6addr_validator_notifier(
            &ipvlan_addr6_vtor_notifier_block);
#endif
        register_inetaddr_notifier(&ipvlan_addr4_notifier_block);
        register_inetaddr_validator_notifier(&ipvlan_addr4_vtor_notifier_block);

        err = ipvlan_l3s_init();
        if (err < 0)
                goto error;

        err = ipvlan_link_register(&ipvlan_link_ops);
        if (err < 0) {
                ipvlan_l3s_cleanup();
                goto error;
        }

        return 0;
error:
        unregister_inetaddr_notifier(&ipvlan_addr4_notifier_block);
        unregister_inetaddr_validator_notifier(
            &ipvlan_addr4_vtor_notifier_block);
#if IS_ENABLED(CONFIG_IPV6)
        unregister_inet6addr_notifier(&ipvlan_addr6_notifier_block);
        unregister_inet6addr_validator_notifier(
            &ipvlan_addr6_vtor_notifier_block);
#endif
        unregister_netdevice_notifier(&ipvlan_notifier_block);
        return err;
}

static void __exit ipvlan_cleanup_module(void)
{
        rtnl_link_unregister(&ipvlan_link_ops);
        ipvlan_l3s_cleanup();
        unregister_netdevice_notifier(&ipvlan_notifier_block);
        unregister_inetaddr_notifier(&ipvlan_addr4_notifier_block);
        unregister_inetaddr_validator_notifier(
            &ipvlan_addr4_vtor_notifier_block);
#if IS_ENABLED(CONFIG_IPV6)
        unregister_inet6addr_notifier(&ipvlan_addr6_notifier_block);
        unregister_inet6addr_validator_notifier(
            &ipvlan_addr6_vtor_notifier_block);
#endif
}

module_init(ipvlan_init_module);
module_exit(ipvlan_cleanup_module);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Mahesh Bandewar <maheshb@google.com>");
MODULE_DESCRIPTION("Driver for L3 (IPv6/IPv4) based VLANs");
MODULE_ALIAS_RTNL_LINK("ipvlan");
MODULE_IMPORT_NS("NETDEV_INTERNAL");