/*
 * Copyright (c) 2018 Cumulus Networks. All rights reserved.
 * Copyright (c) 2018 David Ahern <dsa@cumulusnetworks.com>
 *
 * This software is 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.
 *
 * THE COPYRIGHT HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS"
 * WITHOUT WARRANTY OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING,
 * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE
 * OF THE PROGRAM IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME
 * THE COST OF ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
 */

#include <linux/bitmap.h>
#include <linux/in6.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/rhashtable.h>
#include <linux/spinlock_types.h>
#include <linux/types.h>
#include <net/fib_notifier.h>
#include <net/inet_dscp.h>
#include <net/ip_fib.h>
#include <net/ip6_fib.h>
#include <net/fib_rules.h>
#include <net/net_namespace.h>
#include <net/nexthop.h>
#include <linux/debugfs.h>

#include "netdevsim.h"

struct nsim_fib_entry {
        u64 max;
        atomic64_t num;
};

struct nsim_per_fib_data {
        struct nsim_fib_entry fib;
        struct nsim_fib_entry rules;
};

struct nsim_fib_data {
        struct notifier_block fib_nb;
        struct nsim_per_fib_data ipv4;
        struct nsim_per_fib_data ipv6;
        struct nsim_fib_entry nexthops;
        struct rhashtable fib_rt_ht;
        struct list_head fib_rt_list;
        struct mutex fib_lock; /* Protects FIB HT and list */
        struct notifier_block nexthop_nb;
        struct rhashtable nexthop_ht;
        struct devlink *devlink;
        struct work_struct fib_event_work;
        struct work_struct fib_flush_work;
        struct list_head fib_event_queue;
        spinlock_t fib_event_queue_lock; /* Protects fib event queue list */
        struct mutex nh_lock; /* Protects NH HT */
        struct dentry *ddir;
        bool fail_route_offload;
        bool fail_res_nexthop_group_replace;
        bool fail_nexthop_bucket_replace;
        bool fail_route_delete;
};

struct nsim_fib_rt_key {
        unsigned char addr[sizeof(struct in6_addr)];
        unsigned char prefix_len;
        int family;
        u32 tb_id;
};

struct nsim_fib_rt {
        struct nsim_fib_rt_key key;
        struct rhash_head ht_node;
        struct list_head list;  /* Member of fib_rt_list */
};

struct nsim_fib4_rt {
        struct nsim_fib_rt common;
        struct fib_info *fi;
        dscp_t dscp;
        u8 type;
};

struct nsim_fib6_rt {
        struct nsim_fib_rt common;
        struct list_head nh_list;
        unsigned int nhs;
};

struct nsim_fib6_rt_nh {
        struct list_head list;  /* Member of nh_list */
        struct fib6_info *rt;
};

struct nsim_fib6_event {
        struct fib6_info **rt_arr;
        unsigned int nrt6;
};

struct nsim_fib_event {
        struct list_head list; /* node in fib queue */
        union {
                struct fib_entry_notifier_info fen_info;
                struct nsim_fib6_event fib6_event;
        };
        struct nsim_fib_data *data;
        unsigned long event;
        int family;
};

static const struct rhashtable_params nsim_fib_rt_ht_params = {
        .key_offset = offsetof(struct nsim_fib_rt, key),
        .head_offset = offsetof(struct nsim_fib_rt, ht_node),
        .key_len = sizeof(struct nsim_fib_rt_key),
        .automatic_shrinking = true,
};

struct nsim_nexthop {
        struct rhash_head ht_node;
        u64 occ;
        u32 id;
        bool is_resilient;
};

static const struct rhashtable_params nsim_nexthop_ht_params = {
        .key_offset = offsetof(struct nsim_nexthop, id),
        .head_offset = offsetof(struct nsim_nexthop, ht_node),
        .key_len = sizeof(u32),
        .automatic_shrinking = true,
};

u64 nsim_fib_get_val(struct nsim_fib_data *fib_data,
                     enum nsim_resource_id res_id, bool max)
{
        struct nsim_fib_entry *entry;

        switch (res_id) {
        case NSIM_RESOURCE_IPV4_FIB:
                entry = &fib_data->ipv4.fib;
                break;
        case NSIM_RESOURCE_IPV4_FIB_RULES:
                entry = &fib_data->ipv4.rules;
                break;
        case NSIM_RESOURCE_IPV6_FIB:
                entry = &fib_data->ipv6.fib;
                break;
        case NSIM_RESOURCE_IPV6_FIB_RULES:
                entry = &fib_data->ipv6.rules;
                break;
        case NSIM_RESOURCE_NEXTHOPS:
                entry = &fib_data->nexthops;
                break;
        default:
                return 0;
        }

        return max ? entry->max : atomic64_read(&entry->num);
}

static void nsim_fib_set_max(struct nsim_fib_data *fib_data,
                             enum nsim_resource_id res_id, u64 val)
{
        struct nsim_fib_entry *entry;

        switch (res_id) {
        case NSIM_RESOURCE_IPV4_FIB:
                entry = &fib_data->ipv4.fib;
                break;
        case NSIM_RESOURCE_IPV4_FIB_RULES:
                entry = &fib_data->ipv4.rules;
                break;
        case NSIM_RESOURCE_IPV6_FIB:
                entry = &fib_data->ipv6.fib;
                break;
        case NSIM_RESOURCE_IPV6_FIB_RULES:
                entry = &fib_data->ipv6.rules;
                break;
        case NSIM_RESOURCE_NEXTHOPS:
                entry = &fib_data->nexthops;
                break;
        default:
                WARN_ON(1);
                return;
        }
        entry->max = val;
}

static int nsim_fib_rule_account(struct nsim_fib_entry *entry, bool add,
                                 struct netlink_ext_ack *extack)
{
        int err = 0;

        if (add) {
                if (!atomic64_add_unless(&entry->num, 1, entry->max)) {
                        err = -ENOSPC;
                        NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib rule entries");
                }
        } else {
                atomic64_dec_if_positive(&entry->num);
        }

        return err;
}

static int nsim_fib_rule_event(struct nsim_fib_data *data,
                               struct fib_notifier_info *info, bool add)
{
        struct netlink_ext_ack *extack = info->extack;
        int err = 0;

        switch (info->family) {
        case AF_INET:
                err = nsim_fib_rule_account(&data->ipv4.rules, add, extack);
                break;
        case AF_INET6:
                err = nsim_fib_rule_account(&data->ipv6.rules, add, extack);
                break;
        }

        return err;
}

static int nsim_fib_account(struct nsim_fib_entry *entry, bool add)
{
        int err = 0;

        if (add) {
                if (!atomic64_add_unless(&entry->num, 1, entry->max))
                        err = -ENOSPC;
        } else {
                atomic64_dec_if_positive(&entry->num);
        }

        return err;
}

static void nsim_fib_rt_init(struct nsim_fib_data *data,
                             struct nsim_fib_rt *fib_rt, const void *addr,
                             size_t addr_len, unsigned int prefix_len,
                             int family, u32 tb_id)
{
        memcpy(fib_rt->key.addr, addr, addr_len);
        fib_rt->key.prefix_len = prefix_len;
        fib_rt->key.family = family;
        fib_rt->key.tb_id = tb_id;
        list_add(&fib_rt->list, &data->fib_rt_list);
}

static void nsim_fib_rt_fini(struct nsim_fib_rt *fib_rt)
{
        list_del(&fib_rt->list);
}

static struct nsim_fib_rt *nsim_fib_rt_lookup(struct rhashtable *fib_rt_ht,
                                              const void *addr, size_t addr_len,
                                              unsigned int prefix_len,
                                              int family, u32 tb_id)
{
        struct nsim_fib_rt_key key;

        memset(&key, 0, sizeof(key));
        memcpy(key.addr, addr, addr_len);
        key.prefix_len = prefix_len;
        key.family = family;
        key.tb_id = tb_id;

        return rhashtable_lookup_fast(fib_rt_ht, &key, nsim_fib_rt_ht_params);
}

static struct nsim_fib4_rt *
nsim_fib4_rt_create(struct nsim_fib_data *data,
                    struct fib_entry_notifier_info *fen_info)
{
        struct nsim_fib4_rt *fib4_rt;

        fib4_rt = kzalloc_obj(*fib4_rt);
        if (!fib4_rt)
                return NULL;

        nsim_fib_rt_init(data, &fib4_rt->common, &fen_info->dst, sizeof(u32),
                         fen_info->dst_len, AF_INET, fen_info->tb_id);

        fib4_rt->fi = fen_info->fi;
        fib_info_hold(fib4_rt->fi);
        fib4_rt->dscp = fen_info->dscp;
        fib4_rt->type = fen_info->type;

        return fib4_rt;
}

static void nsim_fib4_rt_destroy(struct nsim_fib4_rt *fib4_rt)
{
        fib_info_put(fib4_rt->fi);
        nsim_fib_rt_fini(&fib4_rt->common);
        kfree(fib4_rt);
}

static struct nsim_fib4_rt *
nsim_fib4_rt_lookup(struct rhashtable *fib_rt_ht,
                    const struct fib_entry_notifier_info *fen_info)
{
        struct nsim_fib_rt *fib_rt;

        fib_rt = nsim_fib_rt_lookup(fib_rt_ht, &fen_info->dst, sizeof(u32),
                                    fen_info->dst_len, AF_INET,
                                    fen_info->tb_id);
        if (!fib_rt)
                return NULL;

        return container_of(fib_rt, struct nsim_fib4_rt, common);
}

static void
nsim_fib4_rt_offload_failed_flag_set(struct net *net,
                                     struct fib_entry_notifier_info *fen_info)
{
        u32 *p_dst = (u32 *)&fen_info->dst;
        struct fib_rt_info fri;

        fri.fi = fen_info->fi;
        fri.tb_id = fen_info->tb_id;
        fri.dst = cpu_to_be32(*p_dst);
        fri.dst_len = fen_info->dst_len;
        fri.dscp = fen_info->dscp;
        fri.type = fen_info->type;
        fri.offload = false;
        fri.trap = false;
        fri.offload_failed = true;
        fib_alias_hw_flags_set(net, &fri);
}

static void nsim_fib4_rt_hw_flags_set(struct net *net,
                                      const struct nsim_fib4_rt *fib4_rt,
                                      bool trap)
{
        u32 *p_dst = (u32 *) fib4_rt->common.key.addr;
        int dst_len = fib4_rt->common.key.prefix_len;
        struct fib_rt_info fri;

        fri.fi = fib4_rt->fi;
        fri.tb_id = fib4_rt->common.key.tb_id;
        fri.dst = cpu_to_be32(*p_dst);
        fri.dst_len = dst_len;
        fri.dscp = fib4_rt->dscp;
        fri.type = fib4_rt->type;
        fri.offload = false;
        fri.trap = trap;
        fri.offload_failed = false;
        fib_alias_hw_flags_set(net, &fri);
}

static int nsim_fib4_rt_add(struct nsim_fib_data *data,
                            struct nsim_fib4_rt *fib4_rt)
{
        struct net *net = devlink_net(data->devlink);
        int err;

        err = rhashtable_insert_fast(&data->fib_rt_ht,
                                     &fib4_rt->common.ht_node,
                                     nsim_fib_rt_ht_params);
        if (err)
                goto err_fib_dismiss;

        /* Simulate hardware programming latency. */
        msleep(1);
        nsim_fib4_rt_hw_flags_set(net, fib4_rt, true);

        return 0;

err_fib_dismiss:
        /* Drop the accounting that was increased from the notification
         * context when FIB_EVENT_ENTRY_REPLACE was triggered.
         */
        nsim_fib_account(&data->ipv4.fib, false);
        return err;
}

static int nsim_fib4_rt_replace(struct nsim_fib_data *data,
                                struct nsim_fib4_rt *fib4_rt,
                                struct nsim_fib4_rt *fib4_rt_old)
{
        struct net *net = devlink_net(data->devlink);
        int err;

        /* We are replacing a route, so need to remove the accounting which
         * was increased when FIB_EVENT_ENTRY_REPLACE was triggered.
         */
        err = nsim_fib_account(&data->ipv4.fib, false);
        if (err)
                return err;
        err = rhashtable_replace_fast(&data->fib_rt_ht,
                                      &fib4_rt_old->common.ht_node,
                                      &fib4_rt->common.ht_node,
                                      nsim_fib_rt_ht_params);
        if (err)
                return err;

        msleep(1);
        nsim_fib4_rt_hw_flags_set(net, fib4_rt, true);

        nsim_fib4_rt_hw_flags_set(net, fib4_rt_old, false);
        nsim_fib4_rt_destroy(fib4_rt_old);

        return 0;
}

static int nsim_fib4_rt_insert(struct nsim_fib_data *data,
                               struct fib_entry_notifier_info *fen_info)
{
        struct nsim_fib4_rt *fib4_rt, *fib4_rt_old;
        int err;

        if (data->fail_route_offload) {
                /* For testing purposes, user set debugfs fail_route_offload
                 * value to true. Simulate hardware programming latency and then
                 * fail.
                 */
                msleep(1);
                return -EINVAL;
        }

        fib4_rt = nsim_fib4_rt_create(data, fen_info);
        if (!fib4_rt)
                return -ENOMEM;

        fib4_rt_old = nsim_fib4_rt_lookup(&data->fib_rt_ht, fen_info);
        if (!fib4_rt_old)
                err = nsim_fib4_rt_add(data, fib4_rt);
        else
                err = nsim_fib4_rt_replace(data, fib4_rt, fib4_rt_old);

        if (err)
                nsim_fib4_rt_destroy(fib4_rt);

        return err;
}

static void nsim_fib4_rt_remove(struct nsim_fib_data *data,
                                const struct fib_entry_notifier_info *fen_info)
{
        struct nsim_fib4_rt *fib4_rt;

        fib4_rt = nsim_fib4_rt_lookup(&data->fib_rt_ht, fen_info);
        if (!fib4_rt)
                return;

        rhashtable_remove_fast(&data->fib_rt_ht, &fib4_rt->common.ht_node,
                               nsim_fib_rt_ht_params);
        nsim_fib4_rt_destroy(fib4_rt);
}

static int nsim_fib4_event(struct nsim_fib_data *data,
                           struct fib_entry_notifier_info *fen_info,
                           unsigned long event)
{
        int err = 0;

        switch (event) {
        case FIB_EVENT_ENTRY_REPLACE:
                err = nsim_fib4_rt_insert(data, fen_info);
                if (err) {
                        struct net *net = devlink_net(data->devlink);

                        nsim_fib4_rt_offload_failed_flag_set(net, fen_info);
                }
                break;
        case FIB_EVENT_ENTRY_DEL:
                nsim_fib4_rt_remove(data, fen_info);
                break;
        default:
                break;
        }

        return err;
}

static struct nsim_fib6_rt_nh *
nsim_fib6_rt_nh_find(const struct nsim_fib6_rt *fib6_rt,
                     const struct fib6_info *rt)
{
        struct nsim_fib6_rt_nh *fib6_rt_nh;

        list_for_each_entry(fib6_rt_nh, &fib6_rt->nh_list, list) {
                if (fib6_rt_nh->rt == rt)
                        return fib6_rt_nh;
        }

        return NULL;
}

static int nsim_fib6_rt_nh_add(struct nsim_fib6_rt *fib6_rt,
                               struct fib6_info *rt)
{
        struct nsim_fib6_rt_nh *fib6_rt_nh;

        fib6_rt_nh = kzalloc_obj(*fib6_rt_nh);
        if (!fib6_rt_nh)
                return -ENOMEM;

        fib6_info_hold(rt);
        fib6_rt_nh->rt = rt;
        list_add_tail(&fib6_rt_nh->list, &fib6_rt->nh_list);
        fib6_rt->nhs++;

        return 0;
}

#if IS_ENABLED(CONFIG_IPV6)
static void nsim_rt6_release(struct fib6_info *rt)
{
        fib6_info_release(rt);
}
#else
static void nsim_rt6_release(struct fib6_info *rt)
{
}
#endif

static void nsim_fib6_rt_nh_del(struct nsim_fib6_rt *fib6_rt,
                                const struct fib6_info *rt)
{
        struct nsim_fib6_rt_nh *fib6_rt_nh;

        fib6_rt_nh = nsim_fib6_rt_nh_find(fib6_rt, rt);
        if (!fib6_rt_nh)
                return;

        fib6_rt->nhs--;
        list_del(&fib6_rt_nh->list);
        nsim_rt6_release(fib6_rt_nh->rt);
        kfree(fib6_rt_nh);
}

static struct nsim_fib6_rt *
nsim_fib6_rt_create(struct nsim_fib_data *data,
                    struct fib6_info **rt_arr, unsigned int nrt6)
{
        struct fib6_info *rt = rt_arr[0];
        struct nsim_fib6_rt *fib6_rt;
        int i = 0;
        int err;

        fib6_rt = kzalloc_obj(*fib6_rt);
        if (!fib6_rt)
                return ERR_PTR(-ENOMEM);

        nsim_fib_rt_init(data, &fib6_rt->common, &rt->fib6_dst.addr,
                         sizeof(rt->fib6_dst.addr), rt->fib6_dst.plen, AF_INET6,
                         rt->fib6_table->tb6_id);

        /* We consider a multipath IPv6 route as one entry, but it can be made
         * up from several fib6_info structs (one for each nexthop), so we
         * add them all to the same list under the entry.
         */
        INIT_LIST_HEAD(&fib6_rt->nh_list);

        for (i = 0; i < nrt6; i++) {
                err = nsim_fib6_rt_nh_add(fib6_rt, rt_arr[i]);
                if (err)
                        goto err_fib6_rt_nh_del;
        }

        return fib6_rt;

err_fib6_rt_nh_del:
        for (i--; i >= 0; i--) {
                nsim_fib6_rt_nh_del(fib6_rt, rt_arr[i]);
        }
        nsim_fib_rt_fini(&fib6_rt->common);
        kfree(fib6_rt);
        return ERR_PTR(err);
}

static void nsim_fib6_rt_destroy(struct nsim_fib6_rt *fib6_rt)
{
        struct nsim_fib6_rt_nh *iter, *tmp;

        list_for_each_entry_safe(iter, tmp, &fib6_rt->nh_list, list)
                nsim_fib6_rt_nh_del(fib6_rt, iter->rt);
        WARN_ON_ONCE(!list_empty(&fib6_rt->nh_list));
        nsim_fib_rt_fini(&fib6_rt->common);
        kfree(fib6_rt);
}

static struct nsim_fib6_rt *
nsim_fib6_rt_lookup(struct rhashtable *fib_rt_ht, const struct fib6_info *rt)
{
        struct nsim_fib_rt *fib_rt;

        fib_rt = nsim_fib_rt_lookup(fib_rt_ht, &rt->fib6_dst.addr,
                                    sizeof(rt->fib6_dst.addr),
                                    rt->fib6_dst.plen, AF_INET6,
                                    rt->fib6_table->tb6_id);
        if (!fib_rt)
                return NULL;

        return container_of(fib_rt, struct nsim_fib6_rt, common);
}

static int nsim_fib6_rt_append(struct nsim_fib_data *data,
                               struct nsim_fib6_event *fib6_event)
{
        struct fib6_info *rt = fib6_event->rt_arr[0];
        struct nsim_fib6_rt *fib6_rt;
        int i, err;

        if (data->fail_route_offload) {
                /* For testing purposes, user set debugfs fail_route_offload
                 * value to true. Simulate hardware programming latency and then
                 * fail.
                 */
                msleep(1);
                return -EINVAL;
        }

        fib6_rt = nsim_fib6_rt_lookup(&data->fib_rt_ht, rt);
        if (!fib6_rt)
                return -EINVAL;

        for (i = 0; i < fib6_event->nrt6; i++) {
                err = nsim_fib6_rt_nh_add(fib6_rt, fib6_event->rt_arr[i]);
                if (err)
                        goto err_fib6_rt_nh_del;

                WRITE_ONCE(fib6_event->rt_arr[i]->trap, true);
        }

        return 0;

err_fib6_rt_nh_del:
        for (i--; i >= 0; i--) {
                WRITE_ONCE(fib6_event->rt_arr[i]->trap, false);
                nsim_fib6_rt_nh_del(fib6_rt, fib6_event->rt_arr[i]);
        }
        return err;
}

#if IS_ENABLED(CONFIG_IPV6)
static void nsim_fib6_rt_offload_failed_flag_set(struct nsim_fib_data *data,
                                                 struct fib6_info **rt_arr,
                                                 unsigned int nrt6)

{
        struct net *net = devlink_net(data->devlink);
        int i;

        for (i = 0; i < nrt6; i++)
                fib6_info_hw_flags_set(net, rt_arr[i], false, false, true);
}
#else
static void nsim_fib6_rt_offload_failed_flag_set(struct nsim_fib_data *data,
                                                 struct fib6_info **rt_arr,
                                                 unsigned int nrt6)
{
}
#endif

#if IS_ENABLED(CONFIG_IPV6)
static void nsim_fib6_rt_hw_flags_set(struct nsim_fib_data *data,
                                      const struct nsim_fib6_rt *fib6_rt,
                                      bool trap)
{
        struct net *net = devlink_net(data->devlink);
        struct nsim_fib6_rt_nh *fib6_rt_nh;

        list_for_each_entry(fib6_rt_nh, &fib6_rt->nh_list, list)
                fib6_info_hw_flags_set(net, fib6_rt_nh->rt, false, trap, false);
}
#else
static void nsim_fib6_rt_hw_flags_set(struct nsim_fib_data *data,
                                      const struct nsim_fib6_rt *fib6_rt,
                                      bool trap)
{
}
#endif

static int nsim_fib6_rt_add(struct nsim_fib_data *data,
                            struct nsim_fib6_rt *fib6_rt)
{
        int err;

        err = rhashtable_insert_fast(&data->fib_rt_ht,
                                     &fib6_rt->common.ht_node,
                                     nsim_fib_rt_ht_params);

        if (err)
                goto err_fib_dismiss;

        msleep(1);
        nsim_fib6_rt_hw_flags_set(data, fib6_rt, true);

        return 0;

err_fib_dismiss:
        /* Drop the accounting that was increased from the notification
         * context when FIB_EVENT_ENTRY_REPLACE was triggered.
         */
        nsim_fib_account(&data->ipv6.fib, false);
        return err;
}

static int nsim_fib6_rt_replace(struct nsim_fib_data *data,
                                struct nsim_fib6_rt *fib6_rt,
                                struct nsim_fib6_rt *fib6_rt_old)
{
        int err;

        /* We are replacing a route, so need to remove the accounting which
         * was increased when FIB_EVENT_ENTRY_REPLACE was triggered.
         */
        err = nsim_fib_account(&data->ipv6.fib, false);
        if (err)
                return err;

        err = rhashtable_replace_fast(&data->fib_rt_ht,
                                      &fib6_rt_old->common.ht_node,
                                      &fib6_rt->common.ht_node,
                                      nsim_fib_rt_ht_params);

        if (err)
                return err;

        msleep(1);
        nsim_fib6_rt_hw_flags_set(data, fib6_rt, true);

        nsim_fib6_rt_hw_flags_set(data, fib6_rt_old, false);
        nsim_fib6_rt_destroy(fib6_rt_old);

        return 0;
}

static int nsim_fib6_rt_insert(struct nsim_fib_data *data,
                               struct nsim_fib6_event *fib6_event)
{
        struct fib6_info *rt = fib6_event->rt_arr[0];
        struct nsim_fib6_rt *fib6_rt, *fib6_rt_old;
        int err;

        if (data->fail_route_offload) {
                /* For testing purposes, user set debugfs fail_route_offload
                 * value to true. Simulate hardware programming latency and then
                 * fail.
                 */
                msleep(1);
                return -EINVAL;
        }

        fib6_rt = nsim_fib6_rt_create(data, fib6_event->rt_arr,
                                      fib6_event->nrt6);
        if (IS_ERR(fib6_rt))
                return PTR_ERR(fib6_rt);

        fib6_rt_old = nsim_fib6_rt_lookup(&data->fib_rt_ht, rt);
        if (!fib6_rt_old)
                err = nsim_fib6_rt_add(data, fib6_rt);
        else
                err = nsim_fib6_rt_replace(data, fib6_rt, fib6_rt_old);

        if (err)
                nsim_fib6_rt_destroy(fib6_rt);

        return err;
}

static void nsim_fib6_rt_remove(struct nsim_fib_data *data,
                                struct nsim_fib6_event *fib6_event)
{
        struct fib6_info *rt = fib6_event->rt_arr[0];
        struct nsim_fib6_rt *fib6_rt;
        int i;

        /* Multipath routes are first added to the FIB trie and only then
         * notified. If we vetoed the addition, we will get a delete
         * notification for a route we do not have. Therefore, do not warn if
         * route was not found.
         */
        fib6_rt = nsim_fib6_rt_lookup(&data->fib_rt_ht, rt);
        if (!fib6_rt)
                return;

        /* If not all the nexthops are deleted, then only reduce the nexthop
         * group.
         */
        if (fib6_event->nrt6 != fib6_rt->nhs) {
                for (i = 0; i < fib6_event->nrt6; i++)
                        nsim_fib6_rt_nh_del(fib6_rt, fib6_event->rt_arr[i]);
                return;
        }

        rhashtable_remove_fast(&data->fib_rt_ht, &fib6_rt->common.ht_node,
                               nsim_fib_rt_ht_params);
        nsim_fib6_rt_destroy(fib6_rt);
}

static int nsim_fib6_event_init(struct nsim_fib6_event *fib6_event,
                                struct fib6_entry_notifier_info *fen6_info)
{
        struct fib6_info *rt = fen6_info->rt;
        struct fib6_info **rt_arr;
        struct fib6_info *iter;
        unsigned int nrt6;
        int i = 0;

        nrt6 = fen6_info->nsiblings + 1;

        rt_arr = kzalloc_objs(struct fib6_info *, nrt6, GFP_ATOMIC);
        if (!rt_arr)
                return -ENOMEM;

        fib6_event->rt_arr = rt_arr;
        fib6_event->nrt6 = nrt6;

        rt_arr[0] = rt;
        fib6_info_hold(rt);

        if (!fen6_info->nsiblings)
                return 0;

        list_for_each_entry(iter, &rt->fib6_siblings, fib6_siblings) {
                if (i == fen6_info->nsiblings)
                        break;

                rt_arr[i + 1] = iter;
                fib6_info_hold(iter);
                i++;
        }
        WARN_ON_ONCE(i != fen6_info->nsiblings);

        return 0;
}

static void nsim_fib6_event_fini(struct nsim_fib6_event *fib6_event)
{
        int i;

        for (i = 0; i < fib6_event->nrt6; i++)
                nsim_rt6_release(fib6_event->rt_arr[i]);
        kfree(fib6_event->rt_arr);
}

static int nsim_fib6_event(struct nsim_fib_data *data,
                           struct nsim_fib6_event *fib6_event,
                           unsigned long event)
{
        int err;

        if (fib6_event->rt_arr[0]->fib6_src.plen)
                return 0;

        switch (event) {
        case FIB_EVENT_ENTRY_REPLACE:
                err = nsim_fib6_rt_insert(data, fib6_event);
                if (err)
                        goto err_rt_offload_failed_flag_set;
                break;
        case FIB_EVENT_ENTRY_APPEND:
                err = nsim_fib6_rt_append(data, fib6_event);
                if (err)
                        goto err_rt_offload_failed_flag_set;
                break;
        case FIB_EVENT_ENTRY_DEL:
                nsim_fib6_rt_remove(data, fib6_event);
                break;
        default:
                break;
        }

        return 0;

err_rt_offload_failed_flag_set:
        nsim_fib6_rt_offload_failed_flag_set(data, fib6_event->rt_arr,
                                             fib6_event->nrt6);
        return err;
}

static void nsim_fib_event(struct nsim_fib_event *fib_event)
{
        switch (fib_event->family) {
        case AF_INET:
                nsim_fib4_event(fib_event->data, &fib_event->fen_info,
                                fib_event->event);
                fib_info_put(fib_event->fen_info.fi);
                break;
        case AF_INET6:
                nsim_fib6_event(fib_event->data, &fib_event->fib6_event,
                                fib_event->event);
                nsim_fib6_event_fini(&fib_event->fib6_event);
                break;
        }
}

static int nsim_fib4_prepare_event(struct fib_notifier_info *info,
                                   struct nsim_fib_event *fib_event,
                                   unsigned long event)
{
        struct nsim_fib_data *data = fib_event->data;
        struct fib_entry_notifier_info *fen_info;
        struct netlink_ext_ack *extack;
        int err = 0;

        fen_info = container_of(info, struct fib_entry_notifier_info,
                                info);
        fib_event->fen_info = *fen_info;
        extack = info->extack;

        switch (event) {
        case FIB_EVENT_ENTRY_REPLACE:
                err = nsim_fib_account(&data->ipv4.fib, true);
                if (err) {
                        NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib entries");
                        return err;
                }
                break;
        case FIB_EVENT_ENTRY_DEL:
                if (data->fail_route_delete) {
                        NL_SET_ERR_MSG_MOD(extack, "Failed to process route deletion");
                        return -EINVAL;
                }
                nsim_fib_account(&data->ipv4.fib, false);
                break;
        }

        /* Take reference on fib_info to prevent it from being
         * freed while event is queued. Release it afterwards.
         */
        fib_info_hold(fib_event->fen_info.fi);

        return 0;
}

static int nsim_fib6_prepare_event(struct fib_notifier_info *info,
                                   struct nsim_fib_event *fib_event,
                                   unsigned long event)
{
        struct nsim_fib_data *data = fib_event->data;
        struct fib6_entry_notifier_info *fen6_info;
        struct netlink_ext_ack *extack;
        int err = 0;

        fen6_info = container_of(info, struct fib6_entry_notifier_info,
                                 info);

        err = nsim_fib6_event_init(&fib_event->fib6_event, fen6_info);
        if (err)
                return err;

        extack = info->extack;
        switch (event) {
        case FIB_EVENT_ENTRY_REPLACE:
                err = nsim_fib_account(&data->ipv6.fib, true);
                if (err) {
                        NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported fib entries");
                        goto err_fib6_event_fini;
                }
                break;
        case FIB_EVENT_ENTRY_DEL:
                if (data->fail_route_delete) {
                        err = -EINVAL;
                        NL_SET_ERR_MSG_MOD(extack, "Failed to process route deletion");
                        goto err_fib6_event_fini;
                }
                nsim_fib_account(&data->ipv6.fib, false);
                break;
        }

        return 0;

err_fib6_event_fini:
        nsim_fib6_event_fini(&fib_event->fib6_event);
        return err;
}

static int nsim_fib_event_schedule_work(struct nsim_fib_data *data,
                                        struct fib_notifier_info *info,
                                        unsigned long event)
{
        struct nsim_fib_event *fib_event;
        int err;

        if (info->family != AF_INET && info->family != AF_INET6)
                /* netdevsim does not support 'RTNL_FAMILY_IP6MR' and
                 * 'RTNL_FAMILY_IPMR' and should ignore them.
                 */
                return NOTIFY_DONE;

        fib_event = kzalloc_obj(*fib_event, GFP_ATOMIC);
        if (!fib_event)
                goto err_fib_event_alloc;

        fib_event->data = data;
        fib_event->event = event;
        fib_event->family = info->family;

        switch (info->family) {
        case AF_INET:
                err = nsim_fib4_prepare_event(info, fib_event, event);
                break;
        case AF_INET6:
                err = nsim_fib6_prepare_event(info, fib_event, event);
                break;
        }

        if (err)
                goto err_fib_prepare_event;

        /* Enqueue the event and trigger the work */
        spin_lock_bh(&data->fib_event_queue_lock);
        list_add_tail(&fib_event->list, &data->fib_event_queue);
        spin_unlock_bh(&data->fib_event_queue_lock);
        schedule_work(&data->fib_event_work);

        return NOTIFY_DONE;

err_fib_prepare_event:
        kfree(fib_event);
err_fib_event_alloc:
        if (event == FIB_EVENT_ENTRY_DEL)
                schedule_work(&data->fib_flush_work);
        return NOTIFY_BAD;
}

static int nsim_fib_event_nb(struct notifier_block *nb, unsigned long event,
                             void *ptr)
{
        struct nsim_fib_data *data = container_of(nb, struct nsim_fib_data,
                                                  fib_nb);
        struct fib_notifier_info *info = ptr;
        int err;

        switch (event) {
        case FIB_EVENT_RULE_ADD:
        case FIB_EVENT_RULE_DEL:
                err = nsim_fib_rule_event(data, info,
                                          event == FIB_EVENT_RULE_ADD);
                return notifier_from_errno(err);
        case FIB_EVENT_ENTRY_REPLACE:
        case FIB_EVENT_ENTRY_APPEND:
        case FIB_EVENT_ENTRY_DEL:
                return nsim_fib_event_schedule_work(data, info, event);
        }

        return NOTIFY_DONE;
}

static void nsim_fib4_rt_free(struct nsim_fib_rt *fib_rt,
                              struct nsim_fib_data *data)
{
        struct devlink *devlink = data->devlink;
        struct nsim_fib4_rt *fib4_rt;

        fib4_rt = container_of(fib_rt, struct nsim_fib4_rt, common);
        nsim_fib4_rt_hw_flags_set(devlink_net(devlink), fib4_rt, false);
        nsim_fib_account(&data->ipv4.fib, false);
        nsim_fib4_rt_destroy(fib4_rt);
}

static void nsim_fib6_rt_free(struct nsim_fib_rt *fib_rt,
                              struct nsim_fib_data *data)
{
        struct nsim_fib6_rt *fib6_rt;

        fib6_rt = container_of(fib_rt, struct nsim_fib6_rt, common);
        nsim_fib6_rt_hw_flags_set(data, fib6_rt, false);
        nsim_fib_account(&data->ipv6.fib, false);
        nsim_fib6_rt_destroy(fib6_rt);
}

static void nsim_fib_rt_free(void *ptr, void *arg)
{
        struct nsim_fib_rt *fib_rt = ptr;
        struct nsim_fib_data *data = arg;

        switch (fib_rt->key.family) {
        case AF_INET:
                nsim_fib4_rt_free(fib_rt, data);
                break;
        case AF_INET6:
                nsim_fib6_rt_free(fib_rt, data);
                break;
        default:
                WARN_ON_ONCE(1);
        }
}

/* inconsistent dump, trying again */
static void nsim_fib_dump_inconsistent(struct notifier_block *nb)
{
        struct nsim_fib_data *data = container_of(nb, struct nsim_fib_data,
                                                  fib_nb);
        struct nsim_fib_rt *fib_rt, *fib_rt_tmp;

        /* Flush the work to make sure there is no race with notifications. */
        flush_work(&data->fib_event_work);

        /* The notifier block is still not registered, so we do not need to
         * take any locks here.
         */
        list_for_each_entry_safe(fib_rt, fib_rt_tmp, &data->fib_rt_list, list) {
                rhashtable_remove_fast(&data->fib_rt_ht, &fib_rt->ht_node,
                                       nsim_fib_rt_ht_params);
                nsim_fib_rt_free(fib_rt, data);
        }

        atomic64_set(&data->ipv4.rules.num, 0ULL);
        atomic64_set(&data->ipv6.rules.num, 0ULL);
}

static struct nsim_nexthop *nsim_nexthop_create(struct nsim_fib_data *data,
                                                struct nh_notifier_info *info)
{
        struct nsim_nexthop *nexthop;
        u64 occ = 0;
        int i;

        nexthop = kzalloc_obj(*nexthop);
        if (!nexthop)
                return ERR_PTR(-ENOMEM);

        nexthop->id = info->id;

        /* Determine the number of nexthop entries the new nexthop will
         * occupy.
         */

        switch (info->type) {
        case NH_NOTIFIER_INFO_TYPE_SINGLE:
                occ = 1;
                break;
        case NH_NOTIFIER_INFO_TYPE_GRP:
                for (i = 0; i < info->nh_grp->num_nh; i++)
                        occ += info->nh_grp->nh_entries[i].weight;
                break;
        case NH_NOTIFIER_INFO_TYPE_RES_TABLE:
                occ = info->nh_res_table->num_nh_buckets;
                nexthop->is_resilient = true;
                break;
        default:
                NL_SET_ERR_MSG_MOD(info->extack, "Unsupported nexthop type");
                kfree(nexthop);
                return ERR_PTR(-EOPNOTSUPP);
        }

        nexthop->occ = occ;
        return nexthop;
}

static void nsim_nexthop_destroy(struct nsim_nexthop *nexthop)
{
        kfree(nexthop);
}

static int nsim_nexthop_account(struct nsim_fib_data *data, u64 occ,
                                bool add, struct netlink_ext_ack *extack)
{
        int i, err = 0;

        if (add) {
                for (i = 0; i < occ; i++)
                        if (!atomic64_add_unless(&data->nexthops.num, 1,
                                                 data->nexthops.max)) {
                                err = -ENOSPC;
                                NL_SET_ERR_MSG_MOD(extack, "Exceeded number of supported nexthops");
                                goto err_num_decrease;
                        }
        } else {
                if (WARN_ON(occ > atomic64_read(&data->nexthops.num)))
                        return -EINVAL;
                atomic64_sub(occ, &data->nexthops.num);
        }

        return err;

err_num_decrease:
        atomic64_sub(i, &data->nexthops.num);
        return err;

}

static void nsim_nexthop_hw_flags_set(struct net *net,
                                      const struct nsim_nexthop *nexthop,
                                      bool trap)
{
        int i;

        nexthop_set_hw_flags(net, nexthop->id, false, trap);

        if (!nexthop->is_resilient)
                return;

        for (i = 0; i < nexthop->occ; i++)
                nexthop_bucket_set_hw_flags(net, nexthop->id, i, false, trap);
}

static int nsim_nexthop_add(struct nsim_fib_data *data,
                            struct nsim_nexthop *nexthop,
                            struct netlink_ext_ack *extack)
{
        struct net *net = devlink_net(data->devlink);
        int err;

        err = nsim_nexthop_account(data, nexthop->occ, true, extack);
        if (err)
                return err;

        err = rhashtable_insert_fast(&data->nexthop_ht, &nexthop->ht_node,
                                     nsim_nexthop_ht_params);
        if (err) {
                NL_SET_ERR_MSG_MOD(extack, "Failed to insert nexthop");
                goto err_nexthop_dismiss;
        }

        nsim_nexthop_hw_flags_set(net, nexthop, true);

        return 0;

err_nexthop_dismiss:
        nsim_nexthop_account(data, nexthop->occ, false, extack);
        return err;
}

static int nsim_nexthop_replace(struct nsim_fib_data *data,
                                struct nsim_nexthop *nexthop,
                                struct nsim_nexthop *nexthop_old,
                                struct netlink_ext_ack *extack)
{
        struct net *net = devlink_net(data->devlink);
        int err;

        err = nsim_nexthop_account(data, nexthop->occ, true, extack);
        if (err)
                return err;

        err = rhashtable_replace_fast(&data->nexthop_ht,
                                      &nexthop_old->ht_node, &nexthop->ht_node,
                                      nsim_nexthop_ht_params);
        if (err) {
                NL_SET_ERR_MSG_MOD(extack, "Failed to replace nexthop");
                goto err_nexthop_dismiss;
        }

        nsim_nexthop_hw_flags_set(net, nexthop, true);
        nsim_nexthop_account(data, nexthop_old->occ, false, extack);
        nsim_nexthop_destroy(nexthop_old);

        return 0;

err_nexthop_dismiss:
        nsim_nexthop_account(data, nexthop->occ, false, extack);
        return err;
}

static int nsim_nexthop_insert(struct nsim_fib_data *data,
                               struct nh_notifier_info *info)
{
        struct nsim_nexthop *nexthop, *nexthop_old;
        int err;

        nexthop = nsim_nexthop_create(data, info);
        if (IS_ERR(nexthop))
                return PTR_ERR(nexthop);

        nexthop_old = rhashtable_lookup_fast(&data->nexthop_ht, &info->id,
                                             nsim_nexthop_ht_params);
        if (!nexthop_old)
                err = nsim_nexthop_add(data, nexthop, info->extack);
        else
                err = nsim_nexthop_replace(data, nexthop, nexthop_old,
                                           info->extack);

        if (err)
                nsim_nexthop_destroy(nexthop);

        return err;
}

static void nsim_nexthop_remove(struct nsim_fib_data *data,
                                struct nh_notifier_info *info)
{
        struct nsim_nexthop *nexthop;

        nexthop = rhashtable_lookup_fast(&data->nexthop_ht, &info->id,
                                         nsim_nexthop_ht_params);
        if (!nexthop)
                return;

        rhashtable_remove_fast(&data->nexthop_ht, &nexthop->ht_node,
                               nsim_nexthop_ht_params);
        nsim_nexthop_account(data, nexthop->occ, false, info->extack);
        nsim_nexthop_destroy(nexthop);
}

static int nsim_nexthop_res_table_pre_replace(struct nsim_fib_data *data,
                                              struct nh_notifier_info *info)
{
        if (data->fail_res_nexthop_group_replace) {
                NL_SET_ERR_MSG_MOD(info->extack, "Failed to replace a resilient nexthop group");
                return -EINVAL;
        }

        return 0;
}

static int nsim_nexthop_bucket_replace(struct nsim_fib_data *data,
                                       struct nh_notifier_info *info)
{
        if (data->fail_nexthop_bucket_replace) {
                NL_SET_ERR_MSG_MOD(info->extack, "Failed to replace nexthop bucket");
                return -EINVAL;
        }

        nexthop_bucket_set_hw_flags(info->net, info->id,
                                    info->nh_res_bucket->bucket_index,
                                    false, true);

        return 0;
}

static int nsim_nexthop_event_nb(struct notifier_block *nb, unsigned long event,
                                 void *ptr)
{
        struct nsim_fib_data *data = container_of(nb, struct nsim_fib_data,
                                                  nexthop_nb);
        struct nh_notifier_info *info = ptr;
        int err = 0;

        mutex_lock(&data->nh_lock);
        switch (event) {
        case NEXTHOP_EVENT_REPLACE:
                err = nsim_nexthop_insert(data, info);
                break;
        case NEXTHOP_EVENT_DEL:
                nsim_nexthop_remove(data, info);
                break;
        case NEXTHOP_EVENT_RES_TABLE_PRE_REPLACE:
                err = nsim_nexthop_res_table_pre_replace(data, info);
                break;
        case NEXTHOP_EVENT_BUCKET_REPLACE:
                err = nsim_nexthop_bucket_replace(data, info);
                break;
        default:
                break;
        }

        mutex_unlock(&data->nh_lock);
        return notifier_from_errno(err);
}

static void nsim_nexthop_free(void *ptr, void *arg)
{
        struct nsim_nexthop *nexthop = ptr;
        struct nsim_fib_data *data = arg;
        struct net *net;

        net = devlink_net(data->devlink);
        nsim_nexthop_hw_flags_set(net, nexthop, false);
        nsim_nexthop_account(data, nexthop->occ, false, NULL);
        nsim_nexthop_destroy(nexthop);
}

static ssize_t nsim_nexthop_bucket_activity_write(struct file *file,
                                                  const char __user *user_buf,
                                                  size_t size, loff_t *ppos)
{
        struct nsim_fib_data *data = file->private_data;
        struct net *net = devlink_net(data->devlink);
        struct nsim_nexthop *nexthop;
        unsigned long *activity;
        loff_t pos = *ppos;
        u16 bucket_index;
        char buf[128];
        int err = 0;
        u32 nhid;

        if (pos != 0)
                return -EINVAL;
        if (size > sizeof(buf) - 1)
                return -EINVAL;
        if (copy_from_user(buf, user_buf, size))
                return -EFAULT;
        buf[size] = 0;

        if (sscanf(buf, "%u %hu", &nhid, &bucket_index) != 2)
                return -EINVAL;

        rtnl_lock();

        nexthop = rhashtable_lookup_fast(&data->nexthop_ht, &nhid,
                                         nsim_nexthop_ht_params);
        if (!nexthop || !nexthop->is_resilient ||
            bucket_index >= nexthop->occ) {
                err = -EINVAL;
                goto out;
        }

        activity = bitmap_zalloc(nexthop->occ, GFP_KERNEL);
        if (!activity) {
                err = -ENOMEM;
                goto out;
        }

        bitmap_set(activity, bucket_index, 1);
        nexthop_res_grp_activity_update(net, nhid, nexthop->occ, activity);
        bitmap_free(activity);

out:
        rtnl_unlock();

        *ppos = size;
        return err ?: size;
}

static const struct file_operations nsim_nexthop_bucket_activity_fops = {
        .open = simple_open,
        .write = nsim_nexthop_bucket_activity_write,
        .owner = THIS_MODULE,
};

static u64 nsim_fib_ipv4_resource_occ_get(void *priv)
{
        struct nsim_fib_data *data = priv;

        return nsim_fib_get_val(data, NSIM_RESOURCE_IPV4_FIB, false);
}

static u64 nsim_fib_ipv4_rules_res_occ_get(void *priv)
{
        struct nsim_fib_data *data = priv;

        return nsim_fib_get_val(data, NSIM_RESOURCE_IPV4_FIB_RULES, false);
}

static u64 nsim_fib_ipv6_resource_occ_get(void *priv)
{
        struct nsim_fib_data *data = priv;

        return nsim_fib_get_val(data, NSIM_RESOURCE_IPV6_FIB, false);
}

static u64 nsim_fib_ipv6_rules_res_occ_get(void *priv)
{
        struct nsim_fib_data *data = priv;

        return nsim_fib_get_val(data, NSIM_RESOURCE_IPV6_FIB_RULES, false);
}

static u64 nsim_fib_nexthops_res_occ_get(void *priv)
{
        struct nsim_fib_data *data = priv;

        return nsim_fib_get_val(data, NSIM_RESOURCE_NEXTHOPS, false);
}

static void nsim_fib_set_max_all(struct nsim_fib_data *data,
                                 struct devlink *devlink)
{
        static const enum nsim_resource_id res_ids[] = {
                NSIM_RESOURCE_IPV4_FIB, NSIM_RESOURCE_IPV4_FIB_RULES,
                NSIM_RESOURCE_IPV6_FIB, NSIM_RESOURCE_IPV6_FIB_RULES,
                NSIM_RESOURCE_NEXTHOPS,
        };
        int i;

        for (i = 0; i < ARRAY_SIZE(res_ids); i++) {
                int err;
                u64 val;

                err = devl_resource_size_get(devlink, res_ids[i], &val);
                if (err)
                        val = (u64) -1;
                nsim_fib_set_max(data, res_ids[i], val);
        }
}

static void nsim_fib_event_work(struct work_struct *work)
{
        struct nsim_fib_data *data = container_of(work, struct nsim_fib_data,
                                                  fib_event_work);
        struct nsim_fib_event *fib_event, *next_fib_event;

        LIST_HEAD(fib_event_queue);

        spin_lock_bh(&data->fib_event_queue_lock);
        list_splice_init(&data->fib_event_queue, &fib_event_queue);
        spin_unlock_bh(&data->fib_event_queue_lock);

        mutex_lock(&data->fib_lock);
        list_for_each_entry_safe(fib_event, next_fib_event, &fib_event_queue,
                                 list) {
                nsim_fib_event(fib_event);
                list_del(&fib_event->list);
                kfree(fib_event);
                cond_resched();
        }
        mutex_unlock(&data->fib_lock);
}

static void nsim_fib_flush_work(struct work_struct *work)
{
        struct nsim_fib_data *data = container_of(work, struct nsim_fib_data,
                                                  fib_flush_work);
        struct nsim_fib_rt *fib_rt, *fib_rt_tmp;

        /* Process pending work. */
        flush_work(&data->fib_event_work);

        mutex_lock(&data->fib_lock);
        list_for_each_entry_safe(fib_rt, fib_rt_tmp, &data->fib_rt_list, list) {
                rhashtable_remove_fast(&data->fib_rt_ht, &fib_rt->ht_node,
                                       nsim_fib_rt_ht_params);
                nsim_fib_rt_free(fib_rt, data);
        }
        mutex_unlock(&data->fib_lock);
}

static int
nsim_fib_debugfs_init(struct nsim_fib_data *data, struct nsim_dev *nsim_dev)
{
        data->ddir = debugfs_create_dir("fib", nsim_dev->ddir);
        if (IS_ERR(data->ddir))
                return PTR_ERR(data->ddir);

        data->fail_route_offload = false;
        debugfs_create_bool("fail_route_offload", 0600, data->ddir,
                            &data->fail_route_offload);

        data->fail_res_nexthop_group_replace = false;
        debugfs_create_bool("fail_res_nexthop_group_replace", 0600, data->ddir,
                            &data->fail_res_nexthop_group_replace);

        data->fail_nexthop_bucket_replace = false;
        debugfs_create_bool("fail_nexthop_bucket_replace", 0600, data->ddir,
                            &data->fail_nexthop_bucket_replace);

        debugfs_create_file("nexthop_bucket_activity", 0200, data->ddir,
                            data, &nsim_nexthop_bucket_activity_fops);

        data->fail_route_delete = false;
        debugfs_create_bool("fail_route_delete", 0600, data->ddir,
                            &data->fail_route_delete);
        return 0;
}

static void nsim_fib_debugfs_exit(struct nsim_fib_data *data)
{
        debugfs_remove_recursive(data->ddir);
}

struct nsim_fib_data *nsim_fib_create(struct devlink *devlink,
                                      struct netlink_ext_ack *extack)
{
        struct nsim_fib_data *data;
        struct nsim_dev *nsim_dev;
        int err;

        data = kzalloc_obj(*data);
        if (!data)
                return ERR_PTR(-ENOMEM);
        data->devlink = devlink;

        nsim_dev = devlink_priv(devlink);
        err = nsim_fib_debugfs_init(data, nsim_dev);
        if (err)
                goto err_data_free;

        mutex_init(&data->nh_lock);
        err = rhashtable_init(&data->nexthop_ht, &nsim_nexthop_ht_params);
        if (err)
                goto err_debugfs_exit;

        mutex_init(&data->fib_lock);
        INIT_LIST_HEAD(&data->fib_rt_list);
        err = rhashtable_init(&data->fib_rt_ht, &nsim_fib_rt_ht_params);
        if (err)
                goto err_rhashtable_nexthop_destroy;

        INIT_WORK(&data->fib_event_work, nsim_fib_event_work);
        INIT_WORK(&data->fib_flush_work, nsim_fib_flush_work);
        INIT_LIST_HEAD(&data->fib_event_queue);
        spin_lock_init(&data->fib_event_queue_lock);

        nsim_fib_set_max_all(data, devlink);

        data->nexthop_nb.notifier_call = nsim_nexthop_event_nb;
        err = register_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb,
                                        extack);
        if (err) {
                pr_err("Failed to register nexthop notifier\n");
                goto err_rhashtable_fib_destroy;
        }

        data->fib_nb.notifier_call = nsim_fib_event_nb;
        err = register_fib_notifier(devlink_net(devlink), &data->fib_nb,
                                    nsim_fib_dump_inconsistent, extack);
        if (err) {
                pr_err("Failed to register fib notifier\n");
                goto err_nexthop_nb_unregister;
        }

        devl_resource_occ_get_register(devlink,
                                       NSIM_RESOURCE_IPV4_FIB,
                                       nsim_fib_ipv4_resource_occ_get,
                                       data);
        devl_resource_occ_get_register(devlink,
                                       NSIM_RESOURCE_IPV4_FIB_RULES,
                                       nsim_fib_ipv4_rules_res_occ_get,
                                       data);
        devl_resource_occ_get_register(devlink,
                                       NSIM_RESOURCE_IPV6_FIB,
                                       nsim_fib_ipv6_resource_occ_get,
                                       data);
        devl_resource_occ_get_register(devlink,
                                       NSIM_RESOURCE_IPV6_FIB_RULES,
                                       nsim_fib_ipv6_rules_res_occ_get,
                                       data);
        devl_resource_occ_get_register(devlink,
                                       NSIM_RESOURCE_NEXTHOPS,
                                       nsim_fib_nexthops_res_occ_get,
                                       data);
        return data;

err_nexthop_nb_unregister:
        unregister_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb);
err_rhashtable_fib_destroy:
        cancel_work_sync(&data->fib_flush_work);
        flush_work(&data->fib_event_work);
        rhashtable_free_and_destroy(&data->fib_rt_ht, nsim_fib_rt_free,
                                    data);
err_rhashtable_nexthop_destroy:
        rhashtable_free_and_destroy(&data->nexthop_ht, nsim_nexthop_free,
                                    data);
        mutex_destroy(&data->fib_lock);
err_debugfs_exit:
        mutex_destroy(&data->nh_lock);
        nsim_fib_debugfs_exit(data);
err_data_free:
        kfree(data);
        return ERR_PTR(err);
}

void nsim_fib_destroy(struct devlink *devlink, struct nsim_fib_data *data)
{
        devl_resource_occ_get_unregister(devlink,
                                         NSIM_RESOURCE_NEXTHOPS);
        devl_resource_occ_get_unregister(devlink,
                                         NSIM_RESOURCE_IPV6_FIB_RULES);
        devl_resource_occ_get_unregister(devlink,
                                         NSIM_RESOURCE_IPV6_FIB);
        devl_resource_occ_get_unregister(devlink,
                                         NSIM_RESOURCE_IPV4_FIB_RULES);
        devl_resource_occ_get_unregister(devlink,
                                         NSIM_RESOURCE_IPV4_FIB);
        unregister_fib_notifier(devlink_net(devlink), &data->fib_nb);
        unregister_nexthop_notifier(devlink_net(devlink), &data->nexthop_nb);
        cancel_work_sync(&data->fib_flush_work);
        flush_work(&data->fib_event_work);
        rhashtable_free_and_destroy(&data->fib_rt_ht, nsim_fib_rt_free,
                                    data);
        rhashtable_free_and_destroy(&data->nexthop_ht, nsim_nexthop_free,
                                    data);
        WARN_ON_ONCE(!list_empty(&data->fib_event_queue));
        WARN_ON_ONCE(!list_empty(&data->fib_rt_list));
        mutex_destroy(&data->fib_lock);
        mutex_destroy(&data->nh_lock);
        nsim_fib_debugfs_exit(data);
        kfree(data);
}