/*
 * Copyright (C) 2017 Netronome Systems, Inc.
 *
 * This software is dual licensed under the GNU General License Version 2,
 * June 1991 as shown in the file COPYING in the top-level directory of this
 * source tree or the BSD 2-Clause License provided below.  You have the
 * option to license this software under the complete terms of either license.
 *
 * The BSD 2-Clause License:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      1. Redistributions of source code must retain the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer.
 *
 *      2. Redistributions in binary form must reproduce the above
 *         copyright notice, this list of conditions and the following
 *         disclaimer in the documentation and/or other materials
 *         provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/etherdevice.h>
#include <linux/inetdevice.h>
#include <net/netevent.h>
#include <linux/idr.h>
#include <net/dst_metadata.h>
#include <net/arp.h>

#include "cmsg.h"
#include "main.h"
#include "../nfp_net_repr.h"
#include "../nfp_net.h"

#define NFP_FL_MAX_ROUTES               32

/**
 * struct nfp_tun_active_tuns - periodic message of active tunnels
 * @seq:                sequence number of the message
 * @count:              number of tunnels report in message
 * @flags:              options part of the request
 * @tun_info.ipv4:              dest IPv4 address of active route
 * @tun_info.egress_port:       port the encapsulated packet egressed
 * @tun_info.extra:             reserved for future use
 * @tun_info:           tunnels that have sent traffic in reported period
 */
struct nfp_tun_active_tuns {
        __be32 seq;
        __be32 count;
        __be32 flags;
        struct route_ip_info {
                __be32 ipv4;
                __be32 egress_port;
                __be32 extra[2];
        } tun_info[];
};

/**
 * struct nfp_tun_neigh - neighbour/route entry on the NFP
 * @dst_ipv4:   destination IPv4 address
 * @src_ipv4:   source IPv4 address
 * @dst_addr:   destination MAC address
 * @src_addr:   source MAC address
 * @port_id:    NFP port to output packet on - associated with source IPv4
 */
struct nfp_tun_neigh {
        __be32 dst_ipv4;
        __be32 src_ipv4;
        u8 dst_addr[ETH_ALEN];
        u8 src_addr[ETH_ALEN];
        __be32 port_id;
};

/**
 * struct nfp_tun_req_route_ipv4 - NFP requests a route/neighbour lookup
 * @ingress_port:       ingress port of packet that signalled request
 * @ipv4_addr:          destination ipv4 address for route
 * @reserved:           reserved for future use
 */
struct nfp_tun_req_route_ipv4 {
        __be32 ingress_port;
        __be32 ipv4_addr;
        __be32 reserved[2];
};

/**
 * struct nfp_ipv4_route_entry - routes that are offloaded to the NFP
 * @ipv4_addr:  destination of route
 * @list:       list pointer
 */
struct nfp_ipv4_route_entry {
        __be32 ipv4_addr;
        struct list_head list;
};

#define NFP_FL_IPV4_ADDRS_MAX        32

/**
 * struct nfp_tun_ipv4_addr - set the IP address list on the NFP
 * @count:      number of IPs populated in the array
 * @ipv4_addr:  array of IPV4_ADDRS_MAX 32 bit IPv4 addresses
 */
struct nfp_tun_ipv4_addr {
        __be32 count;
        __be32 ipv4_addr[NFP_FL_IPV4_ADDRS_MAX];
};

/**
 * struct nfp_ipv4_addr_entry - cached IPv4 addresses
 * @ipv4_addr:  IP address
 * @ref_count:  number of rules currently using this IP
 * @list:       list pointer
 */
struct nfp_ipv4_addr_entry {
        __be32 ipv4_addr;
        int ref_count;
        struct list_head list;
};

/**
 * struct nfp_tun_mac_addr - configure MAC address of tunnel EP on NFP
 * @reserved:   reserved for future use
 * @count:      number of MAC addresses in the message
 * @addresses.index:    index of MAC address in the lookup table
 * @addresses.addr:     interface MAC address
 * @addresses:  series of MACs to offload
 */
struct nfp_tun_mac_addr {
        __be16 reserved;
        __be16 count;
        struct index_mac_addr {
                __be16 index;
                u8 addr[ETH_ALEN];
        } addresses[];
};

/**
 * struct nfp_tun_mac_offload_entry - list of MACs to offload
 * @index:      index of MAC address for offloading
 * @addr:       interface MAC address
 * @list:       list pointer
 */
struct nfp_tun_mac_offload_entry {
        __be16 index;
        u8 addr[ETH_ALEN];
        struct list_head list;
};

#define NFP_MAX_MAC_INDEX       0xff

/**
 * struct nfp_tun_mac_non_nfp_idx - converts non NFP netdev ifindex to 8-bit id
 * @ifindex:    netdev ifindex of the device
 * @index:      index of netdevs mac on NFP
 * @list:       list pointer
 */
struct nfp_tun_mac_non_nfp_idx {
        int ifindex;
        u8 index;
        struct list_head list;
};

void nfp_tunnel_keep_alive(struct nfp_app *app, struct sk_buff *skb)
{
        struct nfp_tun_active_tuns *payload;
        struct net_device *netdev;
        int count, i, pay_len;
        struct neighbour *n;
        __be32 ipv4_addr;
        u32 port;

        payload = nfp_flower_cmsg_get_data(skb);
        count = be32_to_cpu(payload->count);
        if (count > NFP_FL_MAX_ROUTES) {
                nfp_flower_cmsg_warn(app, "Tunnel keep-alive request exceeds max routes.\n");
                return;
        }

        pay_len = nfp_flower_cmsg_get_data_len(skb);
        if (pay_len != sizeof(struct nfp_tun_active_tuns) +
            sizeof(struct route_ip_info) * count) {
                nfp_flower_cmsg_warn(app, "Corruption in tunnel keep-alive message.\n");
                return;
        }

        for (i = 0; i < count; i++) {
                ipv4_addr = payload->tun_info[i].ipv4;
                port = be32_to_cpu(payload->tun_info[i].egress_port);
                netdev = nfp_app_repr_get(app, port);
                if (!netdev)
                        continue;

                n = neigh_lookup(&arp_tbl, &ipv4_addr, netdev);
                if (!n)
                        continue;

                /* Update the used timestamp of neighbour */
                neigh_event_send(n, NULL);
                neigh_release(n);
        }
}

static bool nfp_tun_is_netdev_to_offload(struct net_device *netdev)
{
        if (!netdev->rtnl_link_ops)
                return false;
        if (!strcmp(netdev->rtnl_link_ops->kind, "openvswitch"))
                return true;
        if (!strcmp(netdev->rtnl_link_ops->kind, "vxlan"))
                return true;

        return false;
}

static int
nfp_flower_xmit_tun_conf(struct nfp_app *app, u8 mtype, u16 plen, void *pdata,
                         gfp_t flag)
{
        struct sk_buff *skb;
        unsigned char *msg;

        skb = nfp_flower_cmsg_alloc(app, plen, mtype, flag);
        if (!skb)
                return -ENOMEM;

        msg = nfp_flower_cmsg_get_data(skb);
        memcpy(msg, pdata, nfp_flower_cmsg_get_data_len(skb));

        nfp_ctrl_tx(app->ctrl, skb);
        return 0;
}

static bool nfp_tun_has_route(struct nfp_app *app, __be32 ipv4_addr)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_route_entry *entry;
        struct list_head *ptr, *storage;

        spin_lock_bh(&priv->nfp_neigh_off_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_neigh_off_list) {
                entry = list_entry(ptr, struct nfp_ipv4_route_entry, list);
                if (entry->ipv4_addr == ipv4_addr) {
                        spin_unlock_bh(&priv->nfp_neigh_off_lock);
                        return true;
                }
        }
        spin_unlock_bh(&priv->nfp_neigh_off_lock);
        return false;
}

static void nfp_tun_add_route_to_cache(struct nfp_app *app, __be32 ipv4_addr)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_route_entry *entry;
        struct list_head *ptr, *storage;

        spin_lock_bh(&priv->nfp_neigh_off_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_neigh_off_list) {
                entry = list_entry(ptr, struct nfp_ipv4_route_entry, list);
                if (entry->ipv4_addr == ipv4_addr) {
                        spin_unlock_bh(&priv->nfp_neigh_off_lock);
                        return;
                }
        }
        entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
        if (!entry) {
                spin_unlock_bh(&priv->nfp_neigh_off_lock);
                nfp_flower_cmsg_warn(app, "Mem error when storing new route.\n");
                return;
        }

        entry->ipv4_addr = ipv4_addr;
        list_add_tail(&entry->list, &priv->nfp_neigh_off_list);
        spin_unlock_bh(&priv->nfp_neigh_off_lock);
}

static void nfp_tun_del_route_from_cache(struct nfp_app *app, __be32 ipv4_addr)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_route_entry *entry;
        struct list_head *ptr, *storage;

        spin_lock_bh(&priv->nfp_neigh_off_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_neigh_off_list) {
                entry = list_entry(ptr, struct nfp_ipv4_route_entry, list);
                if (entry->ipv4_addr == ipv4_addr) {
                        list_del(&entry->list);
                        kfree(entry);
                        break;
                }
        }
        spin_unlock_bh(&priv->nfp_neigh_off_lock);
}

static void
nfp_tun_write_neigh(struct net_device *netdev, struct nfp_app *app,
                    struct flowi4 *flow, struct neighbour *neigh, gfp_t flag)
{
        struct nfp_tun_neigh payload;

        /* Only offload representor IPv4s for now. */
        if (!nfp_netdev_is_nfp_repr(netdev))
                return;

        memset(&payload, 0, sizeof(struct nfp_tun_neigh));
        payload.dst_ipv4 = flow->daddr;

        /* If entry has expired send dst IP with all other fields 0. */
        if (!(neigh->nud_state & NUD_VALID)) {
                nfp_tun_del_route_from_cache(app, payload.dst_ipv4);
                /* Trigger ARP to verify invalid neighbour state. */
                neigh_event_send(neigh, NULL);
                goto send_msg;
        }

        /* Have a valid neighbour so populate rest of entry. */
        payload.src_ipv4 = flow->saddr;
        ether_addr_copy(payload.src_addr, netdev->dev_addr);
        neigh_ha_snapshot(payload.dst_addr, neigh, netdev);
        payload.port_id = cpu_to_be32(nfp_repr_get_port_id(netdev));
        /* Add destination of new route to NFP cache. */
        nfp_tun_add_route_to_cache(app, payload.dst_ipv4);

send_msg:
        nfp_flower_xmit_tun_conf(app, NFP_FLOWER_CMSG_TYPE_TUN_NEIGH,
                                 sizeof(struct nfp_tun_neigh),
                                 (unsigned char *)&payload, flag);
}

static int
nfp_tun_neigh_event_handler(struct notifier_block *nb, unsigned long event,
                            void *ptr)
{
        struct nfp_flower_priv *app_priv;
        struct netevent_redirect *redir;
        struct flowi4 flow = {};
        struct neighbour *n;
        struct nfp_app *app;
        struct rtable *rt;
        int err;

        switch (event) {
        case NETEVENT_REDIRECT:
                redir = (struct netevent_redirect *)ptr;
                n = redir->neigh;
                break;
        case NETEVENT_NEIGH_UPDATE:
                n = (struct neighbour *)ptr;
                break;
        default:
                return NOTIFY_DONE;
        }

        flow.daddr = *(__be32 *)n->primary_key;

        /* Only concerned with route changes for representors. */
        if (!nfp_netdev_is_nfp_repr(n->dev))
                return NOTIFY_DONE;

        app_priv = container_of(nb, struct nfp_flower_priv, nfp_tun_neigh_nb);
        app = app_priv->app;

        /* Only concerned with changes to routes already added to NFP. */
        if (!nfp_tun_has_route(app, flow.daddr))
                return NOTIFY_DONE;

#if IS_ENABLED(CONFIG_INET)
        /* Do a route lookup to populate flow data. */
        rt = ip_route_output_key(dev_net(n->dev), &flow);
        err = PTR_ERR_OR_ZERO(rt);
        if (err)
                return NOTIFY_DONE;
#else
        return NOTIFY_DONE;
#endif

        flow.flowi4_proto = IPPROTO_UDP;
        nfp_tun_write_neigh(n->dev, app, &flow, n, GFP_ATOMIC);

        return NOTIFY_OK;
}

void nfp_tunnel_request_route(struct nfp_app *app, struct sk_buff *skb)
{
        struct nfp_tun_req_route_ipv4 *payload;
        struct net_device *netdev;
        struct flowi4 flow = {};
        struct neighbour *n;
        struct rtable *rt;
        int err;

        payload = nfp_flower_cmsg_get_data(skb);

        netdev = nfp_app_repr_get(app, be32_to_cpu(payload->ingress_port));
        if (!netdev)
                goto route_fail_warning;

        flow.daddr = payload->ipv4_addr;
        flow.flowi4_proto = IPPROTO_UDP;

#if IS_ENABLED(CONFIG_INET)
        /* Do a route lookup on same namespace as ingress port. */
        rt = ip_route_output_key(dev_net(netdev), &flow);
        err = PTR_ERR_OR_ZERO(rt);
        if (err)
                goto route_fail_warning;
#else
        goto route_fail_warning;
#endif

        /* Get the neighbour entry for the lookup */
        n = dst_neigh_lookup(&rt->dst, &flow.daddr);
        ip_rt_put(rt);
        if (!n)
                goto route_fail_warning;
        nfp_tun_write_neigh(n->dev, app, &flow, n, GFP_KERNEL);
        neigh_release(n);
        return;

route_fail_warning:
        nfp_flower_cmsg_warn(app, "Requested route not found.\n");
}

static void nfp_tun_write_ipv4_list(struct nfp_app *app)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_addr_entry *entry;
        struct nfp_tun_ipv4_addr payload;
        struct list_head *ptr, *storage;
        int count;

        memset(&payload, 0, sizeof(struct nfp_tun_ipv4_addr));
        mutex_lock(&priv->nfp_ipv4_off_lock);
        count = 0;
        list_for_each_safe(ptr, storage, &priv->nfp_ipv4_off_list) {
                if (count >= NFP_FL_IPV4_ADDRS_MAX) {
                        mutex_unlock(&priv->nfp_ipv4_off_lock);
                        nfp_flower_cmsg_warn(app, "IPv4 offload exceeds limit.\n");
                        return;
                }
                entry = list_entry(ptr, struct nfp_ipv4_addr_entry, list);
                payload.ipv4_addr[count++] = entry->ipv4_addr;
        }
        payload.count = cpu_to_be32(count);
        mutex_unlock(&priv->nfp_ipv4_off_lock);

        nfp_flower_xmit_tun_conf(app, NFP_FLOWER_CMSG_TYPE_TUN_IPS,
                                 sizeof(struct nfp_tun_ipv4_addr),
                                 &payload, GFP_KERNEL);
}

void nfp_tunnel_add_ipv4_off(struct nfp_app *app, __be32 ipv4)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_addr_entry *entry;
        struct list_head *ptr, *storage;

        mutex_lock(&priv->nfp_ipv4_off_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_ipv4_off_list) {
                entry = list_entry(ptr, struct nfp_ipv4_addr_entry, list);
                if (entry->ipv4_addr == ipv4) {
                        entry->ref_count++;
                        mutex_unlock(&priv->nfp_ipv4_off_lock);
                        return;
                }
        }

        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry) {
                mutex_unlock(&priv->nfp_ipv4_off_lock);
                nfp_flower_cmsg_warn(app, "Mem error when offloading IP address.\n");
                return;
        }
        entry->ipv4_addr = ipv4;
        entry->ref_count = 1;
        list_add_tail(&entry->list, &priv->nfp_ipv4_off_list);
        mutex_unlock(&priv->nfp_ipv4_off_lock);

        nfp_tun_write_ipv4_list(app);
}

void nfp_tunnel_del_ipv4_off(struct nfp_app *app, __be32 ipv4)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_addr_entry *entry;
        struct list_head *ptr, *storage;

        mutex_lock(&priv->nfp_ipv4_off_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_ipv4_off_list) {
                entry = list_entry(ptr, struct nfp_ipv4_addr_entry, list);
                if (entry->ipv4_addr == ipv4) {
                        entry->ref_count--;
                        if (!entry->ref_count) {
                                list_del(&entry->list);
                                kfree(entry);
                        }
                        break;
                }
        }
        mutex_unlock(&priv->nfp_ipv4_off_lock);

        nfp_tun_write_ipv4_list(app);
}

void nfp_tunnel_write_macs(struct nfp_app *app)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_tun_mac_offload_entry *entry;
        struct nfp_tun_mac_addr *payload;
        struct list_head *ptr, *storage;
        int mac_count, err, pay_size;

        mutex_lock(&priv->nfp_mac_off_lock);
        if (!priv->nfp_mac_off_count) {
                mutex_unlock(&priv->nfp_mac_off_lock);
                return;
        }

        pay_size = sizeof(struct nfp_tun_mac_addr) +
                   sizeof(struct index_mac_addr) * priv->nfp_mac_off_count;

        payload = kzalloc(pay_size, GFP_KERNEL);
        if (!payload) {
                mutex_unlock(&priv->nfp_mac_off_lock);
                return;
        }

        payload->count = cpu_to_be16(priv->nfp_mac_off_count);

        mac_count = 0;
        list_for_each_safe(ptr, storage, &priv->nfp_mac_off_list) {
                entry = list_entry(ptr, struct nfp_tun_mac_offload_entry,
                                   list);
                payload->addresses[mac_count].index = entry->index;
                ether_addr_copy(payload->addresses[mac_count].addr,
                                entry->addr);
                mac_count++;
        }

        err = nfp_flower_xmit_tun_conf(app, NFP_FLOWER_CMSG_TYPE_TUN_MAC,
                                       pay_size, payload, GFP_KERNEL);

        kfree(payload);

        if (err) {
                mutex_unlock(&priv->nfp_mac_off_lock);
                /* Write failed so retain list for future retry. */
                return;
        }

        /* If list was successfully offloaded, flush it. */
        list_for_each_safe(ptr, storage, &priv->nfp_mac_off_list) {
                entry = list_entry(ptr, struct nfp_tun_mac_offload_entry,
                                   list);
                list_del(&entry->list);
                kfree(entry);
        }

        priv->nfp_mac_off_count = 0;
        mutex_unlock(&priv->nfp_mac_off_lock);
}

static int nfp_tun_get_mac_idx(struct nfp_app *app, int ifindex)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_tun_mac_non_nfp_idx *entry;
        struct list_head *ptr, *storage;
        int idx;

        mutex_lock(&priv->nfp_mac_index_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_mac_index_list) {
                entry = list_entry(ptr, struct nfp_tun_mac_non_nfp_idx, list);
                if (entry->ifindex == ifindex) {
                        idx = entry->index;
                        mutex_unlock(&priv->nfp_mac_index_lock);
                        return idx;
                }
        }

        idx = ida_simple_get(&priv->nfp_mac_off_ids, 0,
                             NFP_MAX_MAC_INDEX, GFP_KERNEL);
        if (idx < 0) {
                mutex_unlock(&priv->nfp_mac_index_lock);
                return idx;
        }

        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry) {
                mutex_unlock(&priv->nfp_mac_index_lock);
                return -ENOMEM;
        }
        entry->ifindex = ifindex;
        entry->index = idx;
        list_add_tail(&entry->list, &priv->nfp_mac_index_list);
        mutex_unlock(&priv->nfp_mac_index_lock);

        return idx;
}

static void nfp_tun_del_mac_idx(struct nfp_app *app, int ifindex)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_tun_mac_non_nfp_idx *entry;
        struct list_head *ptr, *storage;

        mutex_lock(&priv->nfp_mac_index_lock);
        list_for_each_safe(ptr, storage, &priv->nfp_mac_index_list) {
                entry = list_entry(ptr, struct nfp_tun_mac_non_nfp_idx, list);
                if (entry->ifindex == ifindex) {
                        ida_simple_remove(&priv->nfp_mac_off_ids,
                                          entry->index);
                        list_del(&entry->list);
                        kfree(entry);
                        break;
                }
        }
        mutex_unlock(&priv->nfp_mac_index_lock);
}

static void nfp_tun_add_to_mac_offload_list(struct net_device *netdev,
                                            struct nfp_app *app)
{
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_tun_mac_offload_entry *entry;
        u16 nfp_mac_idx;
        int port = 0;

        /* Check if MAC should be offloaded. */
        if (!is_valid_ether_addr(netdev->dev_addr))
                return;

        if (nfp_netdev_is_nfp_repr(netdev))
                port = nfp_repr_get_port_id(netdev);
        else if (!nfp_tun_is_netdev_to_offload(netdev))
                return;

        entry = kmalloc(sizeof(*entry), GFP_KERNEL);
        if (!entry) {
                nfp_flower_cmsg_warn(app, "Mem fail when offloading MAC.\n");
                return;
        }

        if (FIELD_GET(NFP_FLOWER_CMSG_PORT_TYPE, port) ==
            NFP_FLOWER_CMSG_PORT_TYPE_PHYS_PORT) {
                nfp_mac_idx = port << 8 | NFP_FLOWER_CMSG_PORT_TYPE_PHYS_PORT;
        } else if (FIELD_GET(NFP_FLOWER_CMSG_PORT_TYPE, port) ==
                   NFP_FLOWER_CMSG_PORT_TYPE_PCIE_PORT) {
                port = FIELD_GET(NFP_FLOWER_CMSG_PORT_VNIC, port);
                nfp_mac_idx = port << 8 | NFP_FLOWER_CMSG_PORT_TYPE_PCIE_PORT;
        } else {
                /* Must assign our own unique 8-bit index. */
                int idx = nfp_tun_get_mac_idx(app, netdev->ifindex);

                if (idx < 0) {
                        nfp_flower_cmsg_warn(app, "Can't assign non-repr MAC index.\n");
                        kfree(entry);
                        return;
                }
                nfp_mac_idx = idx << 8 | NFP_FLOWER_CMSG_PORT_TYPE_OTHER_PORT;
        }

        entry->index = cpu_to_be16(nfp_mac_idx);
        ether_addr_copy(entry->addr, netdev->dev_addr);

        mutex_lock(&priv->nfp_mac_off_lock);
        priv->nfp_mac_off_count++;
        list_add_tail(&entry->list, &priv->nfp_mac_off_list);
        mutex_unlock(&priv->nfp_mac_off_lock);
}

static int nfp_tun_mac_event_handler(struct notifier_block *nb,
                                     unsigned long event, void *ptr)
{
        struct nfp_flower_priv *app_priv;
        struct net_device *netdev;
        struct nfp_app *app;

        if (event == NETDEV_DOWN || event == NETDEV_UNREGISTER) {
                app_priv = container_of(nb, struct nfp_flower_priv,
                                        nfp_tun_mac_nb);
                app = app_priv->app;
                netdev = netdev_notifier_info_to_dev(ptr);

                /* If non-nfp netdev then free its offload index. */
                if (nfp_tun_is_netdev_to_offload(netdev))
                        nfp_tun_del_mac_idx(app, netdev->ifindex);
        } else if (event == NETDEV_UP || event == NETDEV_CHANGEADDR ||
                   event == NETDEV_REGISTER) {
                app_priv = container_of(nb, struct nfp_flower_priv,
                                        nfp_tun_mac_nb);
                app = app_priv->app;
                netdev = netdev_notifier_info_to_dev(ptr);

                nfp_tun_add_to_mac_offload_list(netdev, app);

                /* Force a list write to keep NFP up to date. */
                nfp_tunnel_write_macs(app);
        }
        return NOTIFY_OK;
}

int nfp_tunnel_config_start(struct nfp_app *app)
{
        struct nfp_flower_priv *priv = app->priv;
        struct net_device *netdev;
        int err;

        /* Initialise priv data for MAC offloading. */
        priv->nfp_mac_off_count = 0;
        mutex_init(&priv->nfp_mac_off_lock);
        INIT_LIST_HEAD(&priv->nfp_mac_off_list);
        priv->nfp_tun_mac_nb.notifier_call = nfp_tun_mac_event_handler;
        mutex_init(&priv->nfp_mac_index_lock);
        INIT_LIST_HEAD(&priv->nfp_mac_index_list);
        ida_init(&priv->nfp_mac_off_ids);

        /* Initialise priv data for IPv4 offloading. */
        mutex_init(&priv->nfp_ipv4_off_lock);
        INIT_LIST_HEAD(&priv->nfp_ipv4_off_list);

        /* Initialise priv data for neighbour offloading. */
        spin_lock_init(&priv->nfp_neigh_off_lock);
        INIT_LIST_HEAD(&priv->nfp_neigh_off_list);
        priv->nfp_tun_neigh_nb.notifier_call = nfp_tun_neigh_event_handler;

        err = register_netdevice_notifier(&priv->nfp_tun_mac_nb);
        if (err)
                goto err_free_mac_ida;

        err = register_netevent_notifier(&priv->nfp_tun_neigh_nb);
        if (err)
                goto err_unreg_mac_nb;

        /* Parse netdevs already registered for MACs that need offloaded. */
        rtnl_lock();
        for_each_netdev(&init_net, netdev)
                nfp_tun_add_to_mac_offload_list(netdev, app);
        rtnl_unlock();

        return 0;

err_unreg_mac_nb:
        unregister_netdevice_notifier(&priv->nfp_tun_mac_nb);
err_free_mac_ida:
        ida_destroy(&priv->nfp_mac_off_ids);
        return err;
}

void nfp_tunnel_config_stop(struct nfp_app *app)
{
        struct nfp_tun_mac_offload_entry *mac_entry;
        struct nfp_flower_priv *priv = app->priv;
        struct nfp_ipv4_route_entry *route_entry;
        struct nfp_tun_mac_non_nfp_idx *mac_idx;
        struct nfp_ipv4_addr_entry *ip_entry;
        struct list_head *ptr, *storage;

        unregister_netdevice_notifier(&priv->nfp_tun_mac_nb);
        unregister_netevent_notifier(&priv->nfp_tun_neigh_nb);

        /* Free any memory that may be occupied by MAC list. */
        list_for_each_safe(ptr, storage, &priv->nfp_mac_off_list) {
                mac_entry = list_entry(ptr, struct nfp_tun_mac_offload_entry,
                                       list);
                list_del(&mac_entry->list);
                kfree(mac_entry);
        }

        /* Free any memory that may be occupied by MAC index list. */
        list_for_each_safe(ptr, storage, &priv->nfp_mac_index_list) {
                mac_idx = list_entry(ptr, struct nfp_tun_mac_non_nfp_idx,
                                     list);
                list_del(&mac_idx->list);
                kfree(mac_idx);
        }

        ida_destroy(&priv->nfp_mac_off_ids);

        /* Free any memory that may be occupied by ipv4 list. */
        list_for_each_safe(ptr, storage, &priv->nfp_ipv4_off_list) {
                ip_entry = list_entry(ptr, struct nfp_ipv4_addr_entry, list);
                list_del(&ip_entry->list);
                kfree(ip_entry);
        }

        /* Free any memory that may be occupied by the route list. */
        list_for_each_safe(ptr, storage, &priv->nfp_neigh_off_list) {
                route_entry = list_entry(ptr, struct nfp_ipv4_route_entry,
                                         list);
                list_del(&route_entry->list);
                kfree(route_entry);
        }
}