/* SPDX-License-Identifier: GPL-2.0 */
#include <linux/kernel.h>
#include <linux/slab.h>
#include <net/act_api.h>
#include <net/flow_offload.h>
#include <linux/rtnetlink.h>
#include <linux/mutex.h>
#include <linux/rhashtable.h>

struct flow_rule *flow_rule_alloc(unsigned int num_actions)
{
        struct flow_rule *rule;
        int i;

        rule = kzalloc_flex(*rule, action.entries, num_actions);
        if (!rule)
                return NULL;

        rule->action.num_entries = num_actions;
        /* Pre-fill each action hw_stats with DONT_CARE.
         * Caller can override this if it wants stats for a given action.
         */
        for (i = 0; i < num_actions; i++)
                rule->action.entries[i].hw_stats = FLOW_ACTION_HW_STATS_DONT_CARE;

        return rule;
}
EXPORT_SYMBOL(flow_rule_alloc);

struct flow_offload_action *offload_action_alloc(unsigned int num_actions)
{
        struct flow_offload_action *fl_action;
        int i;

        fl_action = kzalloc_flex(*fl_action, action.entries, num_actions);
        if (!fl_action)
                return NULL;

        fl_action->action.num_entries = num_actions;
        /* Pre-fill each action hw_stats with DONT_CARE.
         * Caller can override this if it wants stats for a given action.
         */
        for (i = 0; i < num_actions; i++)
                fl_action->action.entries[i].hw_stats = FLOW_ACTION_HW_STATS_DONT_CARE;

        return fl_action;
}

#define FLOW_DISSECTOR_MATCH(__rule, __type, __out)                             \
        const struct flow_match *__m = &(__rule)->match;                        \
        struct flow_dissector *__d = (__m)->dissector;                          \
                                                                                \
        (__out)->key = skb_flow_dissector_target(__d, __type, (__m)->key);      \
        (__out)->mask = skb_flow_dissector_target(__d, __type, (__m)->mask);    \

void flow_rule_match_meta(const struct flow_rule *rule,
                          struct flow_match_meta *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_META, out);
}
EXPORT_SYMBOL(flow_rule_match_meta);

void flow_rule_match_basic(const struct flow_rule *rule,
                           struct flow_match_basic *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_BASIC, out);
}
EXPORT_SYMBOL(flow_rule_match_basic);

void flow_rule_match_control(const struct flow_rule *rule,
                             struct flow_match_control *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_CONTROL, out);
}
EXPORT_SYMBOL(flow_rule_match_control);

void flow_rule_match_eth_addrs(const struct flow_rule *rule,
                               struct flow_match_eth_addrs *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ETH_ADDRS, out);
}
EXPORT_SYMBOL(flow_rule_match_eth_addrs);

void flow_rule_match_vlan(const struct flow_rule *rule,
                          struct flow_match_vlan *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_VLAN, out);
}
EXPORT_SYMBOL(flow_rule_match_vlan);

void flow_rule_match_cvlan(const struct flow_rule *rule,
                           struct flow_match_vlan *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_CVLAN, out);
}
EXPORT_SYMBOL(flow_rule_match_cvlan);

void flow_rule_match_arp(const struct flow_rule *rule,
                         struct flow_match_arp *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ARP, out);
}
EXPORT_SYMBOL(flow_rule_match_arp);

void flow_rule_match_ipv4_addrs(const struct flow_rule *rule,
                                struct flow_match_ipv4_addrs *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IPV4_ADDRS, out);
}
EXPORT_SYMBOL(flow_rule_match_ipv4_addrs);

void flow_rule_match_ipv6_addrs(const struct flow_rule *rule,
                                struct flow_match_ipv6_addrs *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IPV6_ADDRS, out);
}
EXPORT_SYMBOL(flow_rule_match_ipv6_addrs);

void flow_rule_match_ip(const struct flow_rule *rule,
                        struct flow_match_ip *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IP, out);
}
EXPORT_SYMBOL(flow_rule_match_ip);

void flow_rule_match_ports(const struct flow_rule *rule,
                           struct flow_match_ports *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_PORTS, out);
}
EXPORT_SYMBOL(flow_rule_match_ports);

void flow_rule_match_ports_range(const struct flow_rule *rule,
                                 struct flow_match_ports_range *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_PORTS_RANGE, out);
}
EXPORT_SYMBOL(flow_rule_match_ports_range);

void flow_rule_match_tcp(const struct flow_rule *rule,
                         struct flow_match_tcp *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_TCP, out);
}
EXPORT_SYMBOL(flow_rule_match_tcp);

void flow_rule_match_ipsec(const struct flow_rule *rule,
                           struct flow_match_ipsec *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_IPSEC, out);
}
EXPORT_SYMBOL(flow_rule_match_ipsec);

void flow_rule_match_icmp(const struct flow_rule *rule,
                          struct flow_match_icmp *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ICMP, out);
}
EXPORT_SYMBOL(flow_rule_match_icmp);

void flow_rule_match_mpls(const struct flow_rule *rule,
                          struct flow_match_mpls *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_MPLS, out);
}
EXPORT_SYMBOL(flow_rule_match_mpls);

void flow_rule_match_enc_control(const struct flow_rule *rule,
                                 struct flow_match_control *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_CONTROL, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_control);

void flow_rule_match_enc_ipv4_addrs(const struct flow_rule *rule,
                                    struct flow_match_ipv4_addrs *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_IPV4_ADDRS, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_ipv4_addrs);

void flow_rule_match_enc_ipv6_addrs(const struct flow_rule *rule,
                                    struct flow_match_ipv6_addrs *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_IPV6_ADDRS, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_ipv6_addrs);

void flow_rule_match_enc_ip(const struct flow_rule *rule,
                            struct flow_match_ip *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_IP, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_ip);

void flow_rule_match_enc_ports(const struct flow_rule *rule,
                               struct flow_match_ports *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_PORTS, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_ports);

void flow_rule_match_enc_keyid(const struct flow_rule *rule,
                               struct flow_match_enc_keyid *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_KEYID, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_keyid);

void flow_rule_match_enc_opts(const struct flow_rule *rule,
                              struct flow_match_enc_opts *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_ENC_OPTS, out);
}
EXPORT_SYMBOL(flow_rule_match_enc_opts);

struct flow_action_cookie *flow_action_cookie_create(void *data,
                                                     unsigned int len,
                                                     gfp_t gfp)
{
        struct flow_action_cookie *cookie;

        cookie = kmalloc(sizeof(*cookie) + len, gfp);
        if (!cookie)
                return NULL;
        cookie->cookie_len = len;
        memcpy(cookie->cookie, data, len);
        return cookie;
}
EXPORT_SYMBOL(flow_action_cookie_create);

void flow_action_cookie_destroy(struct flow_action_cookie *cookie)
{
        kfree(cookie);
}
EXPORT_SYMBOL(flow_action_cookie_destroy);

void flow_rule_match_ct(const struct flow_rule *rule,
                        struct flow_match_ct *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_CT, out);
}
EXPORT_SYMBOL(flow_rule_match_ct);

void flow_rule_match_pppoe(const struct flow_rule *rule,
                           struct flow_match_pppoe *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_PPPOE, out);
}
EXPORT_SYMBOL(flow_rule_match_pppoe);

void flow_rule_match_l2tpv3(const struct flow_rule *rule,
                            struct flow_match_l2tpv3 *out)
{
        FLOW_DISSECTOR_MATCH(rule, FLOW_DISSECTOR_KEY_L2TPV3, out);
}
EXPORT_SYMBOL(flow_rule_match_l2tpv3);

struct flow_block_cb *flow_block_cb_alloc(flow_setup_cb_t *cb,
                                          void *cb_ident, void *cb_priv,
                                          void (*release)(void *cb_priv))
{
        struct flow_block_cb *block_cb;

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

        block_cb->cb = cb;
        block_cb->cb_ident = cb_ident;
        block_cb->cb_priv = cb_priv;
        block_cb->release = release;

        return block_cb;
}
EXPORT_SYMBOL(flow_block_cb_alloc);

void flow_block_cb_free(struct flow_block_cb *block_cb)
{
        if (block_cb->release)
                block_cb->release(block_cb->cb_priv);

        kfree(block_cb);
}
EXPORT_SYMBOL(flow_block_cb_free);

struct flow_block_cb *flow_block_cb_lookup(struct flow_block *block,
                                           flow_setup_cb_t *cb, void *cb_ident)
{
        struct flow_block_cb *block_cb;

        list_for_each_entry(block_cb, &block->cb_list, list) {
                if (block_cb->cb == cb &&
                    block_cb->cb_ident == cb_ident)
                        return block_cb;
        }

        return NULL;
}
EXPORT_SYMBOL(flow_block_cb_lookup);

void *flow_block_cb_priv(struct flow_block_cb *block_cb)
{
        return block_cb->cb_priv;
}
EXPORT_SYMBOL(flow_block_cb_priv);

void flow_block_cb_incref(struct flow_block_cb *block_cb)
{
        block_cb->refcnt++;
}
EXPORT_SYMBOL(flow_block_cb_incref);

unsigned int flow_block_cb_decref(struct flow_block_cb *block_cb)
{
        return --block_cb->refcnt;
}
EXPORT_SYMBOL(flow_block_cb_decref);

bool flow_block_cb_is_busy(flow_setup_cb_t *cb, void *cb_ident,
                           struct list_head *driver_block_list)
{
        struct flow_block_cb *block_cb;

        list_for_each_entry(block_cb, driver_block_list, driver_list) {
                if (block_cb->cb == cb &&
                    block_cb->cb_ident == cb_ident)
                        return true;
        }

        return false;
}
EXPORT_SYMBOL(flow_block_cb_is_busy);

int flow_block_cb_setup_simple(struct flow_block_offload *f,
                               struct list_head *driver_block_list,
                               flow_setup_cb_t *cb,
                               void *cb_ident, void *cb_priv,
                               bool ingress_only)
{
        struct flow_block_cb *block_cb;

        if (ingress_only &&
            f->binder_type != FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS)
                return -EOPNOTSUPP;

        f->driver_block_list = driver_block_list;

        switch (f->command) {
        case FLOW_BLOCK_BIND:
                if (flow_block_cb_is_busy(cb, cb_ident, driver_block_list))
                        return -EBUSY;

                block_cb = flow_block_cb_alloc(cb, cb_ident, cb_priv, NULL);
                if (IS_ERR(block_cb))
                        return PTR_ERR(block_cb);

                flow_block_cb_add(block_cb, f);
                list_add_tail(&block_cb->driver_list, driver_block_list);
                return 0;
        case FLOW_BLOCK_UNBIND:
                block_cb = flow_block_cb_lookup(f->block, cb, cb_ident);
                if (!block_cb)
                        return -ENOENT;

                flow_block_cb_remove(block_cb, f);
                list_del(&block_cb->driver_list);
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}
EXPORT_SYMBOL(flow_block_cb_setup_simple);

static DEFINE_MUTEX(flow_indr_block_lock);
static LIST_HEAD(flow_block_indr_list);
static LIST_HEAD(flow_block_indr_dev_list);
static LIST_HEAD(flow_indir_dev_list);

struct flow_indr_dev {
        struct list_head                list;
        flow_indr_block_bind_cb_t       *cb;
        void                            *cb_priv;
        refcount_t                      refcnt;
};

static struct flow_indr_dev *flow_indr_dev_alloc(flow_indr_block_bind_cb_t *cb,
                                                 void *cb_priv)
{
        struct flow_indr_dev *indr_dev;

        indr_dev = kmalloc_obj(*indr_dev);
        if (!indr_dev)
                return NULL;

        indr_dev->cb            = cb;
        indr_dev->cb_priv       = cb_priv;
        refcount_set(&indr_dev->refcnt, 1);

        return indr_dev;
}

struct flow_indir_dev_info {
        void *data;
        struct net_device *dev;
        struct Qdisc *sch;
        enum tc_setup_type type;
        void (*cleanup)(struct flow_block_cb *block_cb);
        struct list_head list;
        enum flow_block_command command;
        enum flow_block_binder_type binder_type;
        struct list_head *cb_list;
};

static void existing_qdiscs_register(flow_indr_block_bind_cb_t *cb, void *cb_priv)
{
        struct flow_block_offload bo;
        struct flow_indir_dev_info *cur;

        list_for_each_entry(cur, &flow_indir_dev_list, list) {
                memset(&bo, 0, sizeof(bo));
                bo.command = cur->command;
                bo.binder_type = cur->binder_type;
                INIT_LIST_HEAD(&bo.cb_list);
                cb(cur->dev, cur->sch, cb_priv, cur->type, &bo, cur->data, cur->cleanup);
                list_splice(&bo.cb_list, cur->cb_list);
        }
}

int flow_indr_dev_register(flow_indr_block_bind_cb_t *cb, void *cb_priv)
{
        struct flow_indr_dev *indr_dev;

        mutex_lock(&flow_indr_block_lock);
        list_for_each_entry(indr_dev, &flow_block_indr_dev_list, list) {
                if (indr_dev->cb == cb &&
                    indr_dev->cb_priv == cb_priv) {
                        refcount_inc(&indr_dev->refcnt);
                        mutex_unlock(&flow_indr_block_lock);
                        return 0;
                }
        }

        indr_dev = flow_indr_dev_alloc(cb, cb_priv);
        if (!indr_dev) {
                mutex_unlock(&flow_indr_block_lock);
                return -ENOMEM;
        }

        list_add(&indr_dev->list, &flow_block_indr_dev_list);
        existing_qdiscs_register(cb, cb_priv);
        mutex_unlock(&flow_indr_block_lock);

        tcf_action_reoffload_cb(cb, cb_priv, true);

        return 0;
}
EXPORT_SYMBOL(flow_indr_dev_register);

static void __flow_block_indr_cleanup(void (*release)(void *cb_priv),
                                      void *cb_priv,
                                      struct list_head *cleanup_list)
{
        struct flow_block_cb *this, *next;

        list_for_each_entry_safe(this, next, &flow_block_indr_list, indr.list) {
                if (this->release == release &&
                    this->indr.cb_priv == cb_priv)
                        list_move(&this->indr.list, cleanup_list);
        }
}

static void flow_block_indr_notify(struct list_head *cleanup_list)
{
        struct flow_block_cb *this, *next;

        list_for_each_entry_safe(this, next, cleanup_list, indr.list) {
                list_del(&this->indr.list);
                this->indr.cleanup(this);
        }
}

void flow_indr_dev_unregister(flow_indr_block_bind_cb_t *cb, void *cb_priv,
                              void (*release)(void *cb_priv))
{
        struct flow_indr_dev *this, *next, *indr_dev = NULL;
        LIST_HEAD(cleanup_list);

        mutex_lock(&flow_indr_block_lock);
        list_for_each_entry_safe(this, next, &flow_block_indr_dev_list, list) {
                if (this->cb == cb &&
                    this->cb_priv == cb_priv &&
                    refcount_dec_and_test(&this->refcnt)) {
                        indr_dev = this;
                        list_del(&indr_dev->list);
                        break;
                }
        }

        if (!indr_dev) {
                mutex_unlock(&flow_indr_block_lock);
                return;
        }

        __flow_block_indr_cleanup(release, cb_priv, &cleanup_list);
        mutex_unlock(&flow_indr_block_lock);

        tcf_action_reoffload_cb(cb, cb_priv, false);
        flow_block_indr_notify(&cleanup_list);
        kfree(indr_dev);
}
EXPORT_SYMBOL(flow_indr_dev_unregister);

static void flow_block_indr_init(struct flow_block_cb *flow_block,
                                 struct flow_block_offload *bo,
                                 struct net_device *dev, struct Qdisc *sch, void *data,
                                 void *cb_priv,
                                 void (*cleanup)(struct flow_block_cb *block_cb))
{
        flow_block->indr.binder_type = bo->binder_type;
        flow_block->indr.data = data;
        flow_block->indr.cb_priv = cb_priv;
        flow_block->indr.dev = dev;
        flow_block->indr.sch = sch;
        flow_block->indr.cleanup = cleanup;
}

struct flow_block_cb *flow_indr_block_cb_alloc(flow_setup_cb_t *cb,
                                               void *cb_ident, void *cb_priv,
                                               void (*release)(void *cb_priv),
                                               struct flow_block_offload *bo,
                                               struct net_device *dev,
                                               struct Qdisc *sch, void *data,
                                               void *indr_cb_priv,
                                               void (*cleanup)(struct flow_block_cb *block_cb))
{
        struct flow_block_cb *block_cb;

        block_cb = flow_block_cb_alloc(cb, cb_ident, cb_priv, release);
        if (IS_ERR(block_cb))
                goto out;

        flow_block_indr_init(block_cb, bo, dev, sch, data, indr_cb_priv, cleanup);
        list_add(&block_cb->indr.list, &flow_block_indr_list);

out:
        return block_cb;
}
EXPORT_SYMBOL(flow_indr_block_cb_alloc);

static struct flow_indir_dev_info *find_indir_dev(void *data)
{
        struct flow_indir_dev_info *cur;

        list_for_each_entry(cur, &flow_indir_dev_list, list) {
                if (cur->data == data)
                        return cur;
        }
        return NULL;
}

static int indir_dev_add(void *data, struct net_device *dev, struct Qdisc *sch,
                         enum tc_setup_type type, void (*cleanup)(struct flow_block_cb *block_cb),
                         struct flow_block_offload *bo)
{
        struct flow_indir_dev_info *info;

        info = find_indir_dev(data);
        if (info)
                return -EEXIST;

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

        info->data = data;
        info->dev = dev;
        info->sch = sch;
        info->type = type;
        info->cleanup = cleanup;
        info->command = bo->command;
        info->binder_type = bo->binder_type;
        info->cb_list = bo->cb_list_head;

        list_add(&info->list, &flow_indir_dev_list);
        return 0;
}

static int indir_dev_remove(void *data)
{
        struct flow_indir_dev_info *info;

        info = find_indir_dev(data);
        if (!info)
                return -ENOENT;

        list_del(&info->list);

        kfree(info);
        return 0;
}

int flow_indr_dev_setup_offload(struct net_device *dev, struct Qdisc *sch,
                                enum tc_setup_type type, void *data,
                                struct flow_block_offload *bo,
                                void (*cleanup)(struct flow_block_cb *block_cb))
{
        struct flow_indr_dev *this;
        u32 count = 0;
        int err;

        mutex_lock(&flow_indr_block_lock);
        if (bo) {
                if (bo->command == FLOW_BLOCK_BIND)
                        indir_dev_add(data, dev, sch, type, cleanup, bo);
                else if (bo->command == FLOW_BLOCK_UNBIND)
                        indir_dev_remove(data);
        }

        list_for_each_entry(this, &flow_block_indr_dev_list, list) {
                err = this->cb(dev, sch, this->cb_priv, type, bo, data, cleanup);
                if (!err)
                        count++;
        }

        mutex_unlock(&flow_indr_block_lock);

        return (bo && list_empty(&bo->cb_list)) ? -EOPNOTSUPP : count;
}
EXPORT_SYMBOL(flow_indr_dev_setup_offload);

bool flow_indr_dev_exists(void)
{
        return !list_empty(&flow_block_indr_dev_list);
}
EXPORT_SYMBOL(flow_indr_dev_exists);