// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * net/sched/cls_u32.c  Ugly (or Universal) 32bit key Packet Classifier.
 *
 * Authors:     Alexey Kuznetsov, <kuznet@ms2.inr.ac.ru>
 *
 *      The filters are packed to hash tables of key nodes
 *      with a set of 32bit key/mask pairs at every node.
 *      Nodes reference next level hash tables etc.
 *
 *      This scheme is the best universal classifier I managed to
 *      invent; it is not super-fast, but it is not slow (provided you
 *      program it correctly), and general enough.  And its relative
 *      speed grows as the number of rules becomes larger.
 *
 *      It seems that it represents the best middle point between
 *      speed and manageability both by human and by machine.
 *
 *      It is especially useful for link sharing combined with QoS;
 *      pure RSVP doesn't need such a general approach and can use
 *      much simpler (and faster) schemes, sort of cls_rsvp.c.
 *
 *      nfmark match added by Catalin(ux aka Dino) BOIE <catab at umbrella.ro>
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/percpu.h>
#include <linux/rtnetlink.h>
#include <linux/skbuff.h>
#include <linux/bitmap.h>
#include <linux/netdevice.h>
#include <linux/hash.h>
#include <net/netlink.h>
#include <net/act_api.h>
#include <net/pkt_cls.h>
#include <linux/idr.h>
#include <net/tc_wrapper.h>

struct tc_u_knode {
        struct tc_u_knode __rcu *next;
        u32                     handle;
        struct tc_u_hnode __rcu *ht_up;
        struct tcf_exts         exts;
        int                     ifindex;
        u8                      fshift;
        struct tcf_result       res;
        struct tc_u_hnode __rcu *ht_down;
#ifdef CONFIG_CLS_U32_PERF
        struct tc_u32_pcnt __percpu *pf;
#endif
        u32                     flags;
        unsigned int            in_hw_count;
#ifdef CONFIG_CLS_U32_MARK
        u32                     val;
        u32                     mask;
        u32 __percpu            *pcpu_success;
#endif
        struct rcu_work         rwork;
        /* The 'sel' field MUST be the last field in structure to allow for
         * tc_u32_keys allocated at end of structure.
         */
        struct tc_u32_sel       sel;
};

struct tc_u_hnode {
        struct tc_u_hnode __rcu *next;
        u32                     handle;
        u32                     prio;
        refcount_t              refcnt;
        unsigned int            divisor;
        struct idr              handle_idr;
        bool                    is_root;
        struct rcu_head         rcu;
        u32                     flags;
        /* The 'ht' field MUST be the last field in structure to allow for
         * more entries allocated at end of structure.
         */
        struct tc_u_knode __rcu *ht[];
};

struct tc_u_common {
        struct tc_u_hnode __rcu *hlist;
        void                    *ptr;
        refcount_t              refcnt;
        struct idr              handle_idr;
        struct hlist_node       hnode;
        long                    knodes;
};

static u32 handle2id(u32 h)
{
        return ((h & 0x80000000) ? ((h >> 20) & 0x7FF) : h);
}

static u32 id2handle(u32 id)
{
        return (id | 0x800U) << 20;
}

static inline unsigned int u32_hash_fold(__be32 key,
                                         const struct tc_u32_sel *sel,
                                         u8 fshift)
{
        unsigned int h = ntohl(key & sel->hmask) >> fshift;

        return h;
}

TC_INDIRECT_SCOPE int u32_classify(struct sk_buff *skb,
                                   const struct tcf_proto *tp,
                                   struct tcf_result *res)
{
        struct {
                struct tc_u_knode *knode;
                unsigned int      off;
        } stack[TC_U32_MAXDEPTH];

        struct tc_u_hnode *ht = rcu_dereference_bh(tp->root);
        unsigned int off = skb_network_offset(skb);
        struct tc_u_knode *n;
        int sdepth = 0;
        int off2 = 0;
        int sel = 0;
#ifdef CONFIG_CLS_U32_PERF
        int j;
#endif
        int i, r;

next_ht:
        n = rcu_dereference_bh(ht->ht[sel]);

next_knode:
        if (n) {
                struct tc_u32_key *key = n->sel.keys;

#ifdef CONFIG_CLS_U32_PERF
                __this_cpu_inc(n->pf->rcnt);
                j = 0;
#endif

                if (tc_skip_sw(n->flags)) {
                        n = rcu_dereference_bh(n->next);
                        goto next_knode;
                }

#ifdef CONFIG_CLS_U32_MARK
                if ((skb->mark & n->mask) != n->val) {
                        n = rcu_dereference_bh(n->next);
                        goto next_knode;
                } else {
                        __this_cpu_inc(*n->pcpu_success);
                }
#endif

                for (i = n->sel.nkeys; i > 0; i--, key++) {
                        int toff = off + key->off + (off2 & key->offmask);
                        __be32 *data, hdata;

                        data = skb_header_pointer_careful(skb, toff, 4,
                                                          &hdata);
                        if (!data)
                                goto out;
                        if ((*data ^ key->val) & key->mask) {
                                n = rcu_dereference_bh(n->next);
                                goto next_knode;
                        }
#ifdef CONFIG_CLS_U32_PERF
                        __this_cpu_inc(n->pf->kcnts[j]);
                        j++;
#endif
                }

                ht = rcu_dereference_bh(n->ht_down);
                if (!ht) {
check_terminal:
                        if (n->sel.flags & TC_U32_TERMINAL) {

                                *res = n->res;
                                if (!tcf_match_indev(skb, n->ifindex)) {
                                        n = rcu_dereference_bh(n->next);
                                        goto next_knode;
                                }
#ifdef CONFIG_CLS_U32_PERF
                                __this_cpu_inc(n->pf->rhit);
#endif
                                r = tcf_exts_exec(skb, &n->exts, res);
                                if (r < 0) {
                                        n = rcu_dereference_bh(n->next);
                                        goto next_knode;
                                }

                                return r;
                        }
                        n = rcu_dereference_bh(n->next);
                        goto next_knode;
                }

                /* PUSH */
                if (sdepth >= TC_U32_MAXDEPTH)
                        goto deadloop;
                stack[sdepth].knode = n;
                stack[sdepth].off = off;
                sdepth++;

                ht = rcu_dereference_bh(n->ht_down);
                sel = 0;
                if (ht->divisor) {
                        __be32 *data, hdata;

                        data = skb_header_pointer_careful(skb,
                                                          off + n->sel.hoff,
                                                          4, &hdata);
                        if (!data)
                                goto out;
                        sel = ht->divisor & u32_hash_fold(*data, &n->sel,
                                                          n->fshift);
                }
                if (!(n->sel.flags & (TC_U32_VAROFFSET | TC_U32_OFFSET | TC_U32_EAT)))
                        goto next_ht;

                if (n->sel.flags & (TC_U32_OFFSET | TC_U32_VAROFFSET)) {
                        off2 = n->sel.off + 3;
                        if (n->sel.flags & TC_U32_VAROFFSET) {
                                __be16 *data, hdata;

                                data = skb_header_pointer_careful(skb,
                                                          off + n->sel.offoff,
                                                          2, &hdata);
                                if (!data)
                                        goto out;
                                off2 += ntohs(n->sel.offmask & *data) >>
                                        n->sel.offshift;
                        }
                        off2 &= ~3;
                }
                if (n->sel.flags & TC_U32_EAT) {
                        off += off2;
                        off2 = 0;
                }

                if (off < skb->len)
                        goto next_ht;
        }

        /* POP */
        if (sdepth--) {
                n = stack[sdepth].knode;
                ht = rcu_dereference_bh(n->ht_up);
                off = stack[sdepth].off;
                goto check_terminal;
        }
out:
        return -1;

deadloop:
        net_warn_ratelimited("cls_u32: dead loop\n");
        return -1;
}

static struct tc_u_hnode *u32_lookup_ht(struct tc_u_common *tp_c, u32 handle)
{
        struct tc_u_hnode *ht;

        for (ht = rtnl_dereference(tp_c->hlist);
             ht;
             ht = rtnl_dereference(ht->next))
                if (ht->handle == handle)
                        break;

        return ht;
}

static struct tc_u_knode *u32_lookup_key(struct tc_u_hnode *ht, u32 handle)
{
        unsigned int sel;
        struct tc_u_knode *n = NULL;

        sel = TC_U32_HASH(handle);
        if (sel > ht->divisor)
                goto out;

        for (n = rtnl_dereference(ht->ht[sel]);
             n;
             n = rtnl_dereference(n->next))
                if (n->handle == handle)
                        break;
out:
        return n;
}


static void *u32_get(struct tcf_proto *tp, u32 handle)
{
        struct tc_u_hnode *ht;
        struct tc_u_common *tp_c = tp->data;

        if (TC_U32_HTID(handle) == TC_U32_ROOT)
                ht = rtnl_dereference(tp->root);
        else
                ht = u32_lookup_ht(tp_c, TC_U32_HTID(handle));

        if (!ht)
                return NULL;

        if (TC_U32_KEY(handle) == 0)
                return ht;

        return u32_lookup_key(ht, handle);
}

/* Protected by rtnl lock */
static u32 gen_new_htid(struct tc_u_common *tp_c, struct tc_u_hnode *ptr)
{
        int id = idr_alloc_cyclic(&tp_c->handle_idr, ptr, 1, 0x7FF, GFP_KERNEL);
        if (id < 0)
                return 0;
        return id2handle(id);
}

static struct hlist_head *tc_u_common_hash;

#define U32_HASH_SHIFT 10
#define U32_HASH_SIZE (1 << U32_HASH_SHIFT)

static void *tc_u_common_ptr(const struct tcf_proto *tp)
{
        struct tcf_block *block = tp->chain->block;

        /* The block sharing is currently supported only
         * for classless qdiscs. In that case we use block
         * for tc_u_common identification. In case the
         * block is not shared, block->q is a valid pointer
         * and we can use that. That works for classful qdiscs.
         */
        if (tcf_block_shared(block))
                return block;
        else
                return block->q;
}

static struct hlist_head *tc_u_hash(void *key)
{
        return tc_u_common_hash + hash_ptr(key, U32_HASH_SHIFT);
}

static struct tc_u_common *tc_u_common_find(void *key)
{
        struct tc_u_common *tc;
        hlist_for_each_entry(tc, tc_u_hash(key), hnode) {
                if (tc->ptr == key)
                        return tc;
        }
        return NULL;
}

static int u32_init(struct tcf_proto *tp)
{
        struct tc_u_hnode *root_ht;
        void *key = tc_u_common_ptr(tp);
        struct tc_u_common *tp_c = tc_u_common_find(key);

        root_ht = kzalloc_flex(*root_ht, ht, 1);
        if (root_ht == NULL)
                return -ENOBUFS;

        refcount_set(&root_ht->refcnt, 1);
        root_ht->handle = tp_c ? gen_new_htid(tp_c, root_ht) : id2handle(0);
        root_ht->prio = tp->prio;
        root_ht->is_root = true;
        idr_init(&root_ht->handle_idr);

        if (tp_c == NULL) {
                tp_c = kzalloc_obj(*tp_c);
                if (tp_c == NULL) {
                        kfree(root_ht);
                        return -ENOBUFS;
                }
                refcount_set(&tp_c->refcnt, 1);
                tp_c->ptr = key;
                INIT_HLIST_NODE(&tp_c->hnode);
                idr_init(&tp_c->handle_idr);

                hlist_add_head(&tp_c->hnode, tc_u_hash(key));
        } else {
                refcount_inc(&tp_c->refcnt);
        }

        RCU_INIT_POINTER(root_ht->next, tp_c->hlist);
        rcu_assign_pointer(tp_c->hlist, root_ht);

        /* root_ht must be destroyed when tcf_proto is destroyed */
        rcu_assign_pointer(tp->root, root_ht);
        tp->data = tp_c;
        return 0;
}

static void __u32_destroy_key(struct tc_u_knode *n)
{
        struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);

        tcf_exts_destroy(&n->exts);
        if (ht && refcount_dec_and_test(&ht->refcnt))
                kfree(ht);
        kfree(n);
}

static void u32_destroy_key(struct tc_u_knode *n, bool free_pf)
{
        tcf_exts_put_net(&n->exts);
#ifdef CONFIG_CLS_U32_PERF
        if (free_pf)
                free_percpu(n->pf);
#endif
#ifdef CONFIG_CLS_U32_MARK
        if (free_pf)
                free_percpu(n->pcpu_success);
#endif
        __u32_destroy_key(n);
}

/* u32_delete_key_rcu should be called when free'ing a copied
 * version of a tc_u_knode obtained from u32_init_knode(). When
 * copies are obtained from u32_init_knode() the statistics are
 * shared between the old and new copies to allow readers to
 * continue to update the statistics during the copy. To support
 * this the u32_delete_key_rcu variant does not free the percpu
 * statistics.
 */
static void u32_delete_key_work(struct work_struct *work)
{
        struct tc_u_knode *key = container_of(to_rcu_work(work),
                                              struct tc_u_knode,
                                              rwork);
        rtnl_lock();
        u32_destroy_key(key, false);
        rtnl_unlock();
}

/* u32_delete_key_freepf_rcu is the rcu callback variant
 * that free's the entire structure including the statistics
 * percpu variables. Only use this if the key is not a copy
 * returned by u32_init_knode(). See u32_delete_key_rcu()
 * for the variant that should be used with keys return from
 * u32_init_knode()
 */
static void u32_delete_key_freepf_work(struct work_struct *work)
{
        struct tc_u_knode *key = container_of(to_rcu_work(work),
                                              struct tc_u_knode,
                                              rwork);
        rtnl_lock();
        u32_destroy_key(key, true);
        rtnl_unlock();
}

static int u32_delete_key(struct tcf_proto *tp, struct tc_u_knode *key)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_knode __rcu **kp;
        struct tc_u_knode *pkp;
        struct tc_u_hnode *ht = rtnl_dereference(key->ht_up);

        if (ht) {
                kp = &ht->ht[TC_U32_HASH(key->handle)];
                for (pkp = rtnl_dereference(*kp); pkp;
                     kp = &pkp->next, pkp = rtnl_dereference(*kp)) {
                        if (pkp == key) {
                                RCU_INIT_POINTER(*kp, key->next);
                                tp_c->knodes--;

                                tcf_unbind_filter(tp, &key->res);
                                idr_remove(&ht->handle_idr, key->handle);
                                tcf_exts_get_net(&key->exts);
                                tcf_queue_work(&key->rwork, u32_delete_key_freepf_work);
                                return 0;
                        }
                }
        }
        WARN_ON(1);
        return 0;
}

static void u32_clear_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
                               struct netlink_ext_ack *extack)
{
        struct tcf_block *block = tp->chain->block;
        struct tc_cls_u32_offload cls_u32 = {};

        tc_cls_common_offload_init(&cls_u32.common, tp, h->flags, extack);
        cls_u32.command = TC_CLSU32_DELETE_HNODE;
        cls_u32.hnode.divisor = h->divisor;
        cls_u32.hnode.handle = h->handle;
        cls_u32.hnode.prio = h->prio;

        tc_setup_cb_call(block, TC_SETUP_CLSU32, &cls_u32, false, true);
}

static int u32_replace_hw_hnode(struct tcf_proto *tp, struct tc_u_hnode *h,
                                u32 flags, struct netlink_ext_ack *extack)
{
        struct tcf_block *block = tp->chain->block;
        struct tc_cls_u32_offload cls_u32 = {};
        bool skip_sw = tc_skip_sw(flags);
        bool offloaded = false;
        int err;

        tc_cls_common_offload_init(&cls_u32.common, tp, flags, extack);
        cls_u32.command = TC_CLSU32_NEW_HNODE;
        cls_u32.hnode.divisor = h->divisor;
        cls_u32.hnode.handle = h->handle;
        cls_u32.hnode.prio = h->prio;

        err = tc_setup_cb_call(block, TC_SETUP_CLSU32, &cls_u32, skip_sw, true);
        if (err < 0) {
                u32_clear_hw_hnode(tp, h, NULL);
                return err;
        } else if (err > 0) {
                offloaded = true;
        }

        if (skip_sw && !offloaded)
                return -EINVAL;

        return 0;
}

static void u32_remove_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
                                struct netlink_ext_ack *extack)
{
        struct tcf_block *block = tp->chain->block;
        struct tc_cls_u32_offload cls_u32 = {};

        tc_cls_common_offload_init(&cls_u32.common, tp, n->flags, extack);
        cls_u32.command = TC_CLSU32_DELETE_KNODE;
        cls_u32.knode.handle = n->handle;

        tc_setup_cb_destroy(block, tp, TC_SETUP_CLSU32, &cls_u32, false,
                            &n->flags, &n->in_hw_count, true);
}

static int u32_replace_hw_knode(struct tcf_proto *tp, struct tc_u_knode *n,
                                u32 flags, struct netlink_ext_ack *extack)
{
        struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);
        struct tcf_block *block = tp->chain->block;
        struct tc_cls_u32_offload cls_u32 = {};
        bool skip_sw = tc_skip_sw(flags);
        int err;

        tc_cls_common_offload_init(&cls_u32.common, tp, flags, extack);
        cls_u32.command = TC_CLSU32_REPLACE_KNODE;
        cls_u32.knode.handle = n->handle;
        cls_u32.knode.fshift = n->fshift;
#ifdef CONFIG_CLS_U32_MARK
        cls_u32.knode.val = n->val;
        cls_u32.knode.mask = n->mask;
#else
        cls_u32.knode.val = 0;
        cls_u32.knode.mask = 0;
#endif
        cls_u32.knode.sel = &n->sel;
        cls_u32.knode.res = &n->res;
        cls_u32.knode.exts = &n->exts;
        if (n->ht_down)
                cls_u32.knode.link_handle = ht->handle;

        err = tc_setup_cb_add(block, tp, TC_SETUP_CLSU32, &cls_u32, skip_sw,
                              &n->flags, &n->in_hw_count, true);
        if (err) {
                u32_remove_hw_knode(tp, n, NULL);
                return err;
        }

        if (skip_sw && !(n->flags & TCA_CLS_FLAGS_IN_HW))
                return -EINVAL;

        return 0;
}

static void u32_clear_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
                            struct netlink_ext_ack *extack)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_knode *n;
        unsigned int h;

        for (h = 0; h <= ht->divisor; h++) {
                while ((n = rtnl_dereference(ht->ht[h])) != NULL) {
                        RCU_INIT_POINTER(ht->ht[h],
                                         rtnl_dereference(n->next));
                        tp_c->knodes--;
                        tcf_unbind_filter(tp, &n->res);
                        u32_remove_hw_knode(tp, n, extack);
                        idr_remove(&ht->handle_idr, n->handle);
                        if (tcf_exts_get_net(&n->exts))
                                tcf_queue_work(&n->rwork, u32_delete_key_freepf_work);
                        else
                                u32_destroy_key(n, true);
                }
        }
}

static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
                             struct netlink_ext_ack *extack)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_hnode __rcu **hn;
        struct tc_u_hnode *phn;

        u32_clear_hnode(tp, ht, extack);

        hn = &tp_c->hlist;
        for (phn = rtnl_dereference(*hn);
             phn;
             hn = &phn->next, phn = rtnl_dereference(*hn)) {
                if (phn == ht) {
                        u32_clear_hw_hnode(tp, ht, extack);
                        idr_destroy(&ht->handle_idr);
                        idr_remove(&tp_c->handle_idr, handle2id(ht->handle));
                        RCU_INIT_POINTER(*hn, ht->next);
                        kfree_rcu(ht, rcu);
                        return 0;
                }
        }

        return -ENOENT;
}

static void u32_destroy(struct tcf_proto *tp, bool rtnl_held,
                        struct netlink_ext_ack *extack)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_hnode *root_ht = rtnl_dereference(tp->root);

        WARN_ON(root_ht == NULL);

        if (root_ht && refcount_dec_and_test(&root_ht->refcnt))
                u32_destroy_hnode(tp, root_ht, extack);

        if (refcount_dec_and_test(&tp_c->refcnt)) {
                struct tc_u_hnode *ht;

                hlist_del(&tp_c->hnode);

                while ((ht = rtnl_dereference(tp_c->hlist)) != NULL) {
                        u32_clear_hnode(tp, ht, extack);
                        RCU_INIT_POINTER(tp_c->hlist, ht->next);

                        /* u32_destroy_key() will later free ht for us, if it's
                         * still referenced by some knode
                         */
                        if (refcount_dec_and_test(&ht->refcnt))
                                kfree_rcu(ht, rcu);
                }

                idr_destroy(&tp_c->handle_idr);
                kfree(tp_c);
        }

        tp->data = NULL;
}

static int u32_delete(struct tcf_proto *tp, void *arg, bool *last,
                      bool rtnl_held, struct netlink_ext_ack *extack)
{
        struct tc_u_hnode *ht = arg;
        struct tc_u_common *tp_c = tp->data;
        int ret = 0;

        if (TC_U32_KEY(ht->handle)) {
                u32_remove_hw_knode(tp, (struct tc_u_knode *)ht, extack);
                ret = u32_delete_key(tp, (struct tc_u_knode *)ht);
                goto out;
        }

        if (ht->is_root) {
                NL_SET_ERR_MSG_MOD(extack, "Not allowed to delete root node");
                return -EINVAL;
        }

        if (refcount_dec_if_one(&ht->refcnt)) {
                u32_destroy_hnode(tp, ht, extack);
        } else {
                NL_SET_ERR_MSG_MOD(extack, "Can not delete in-use filter");
                return -EBUSY;
        }

out:
        *last = refcount_read(&tp_c->refcnt) == 1 && tp_c->knodes == 0;
        return ret;
}

static u32 gen_new_kid(struct tc_u_hnode *ht, u32 htid)
{
        u32 index = htid | 0x800;
        u32 max = htid | 0xFFF;

        if (idr_alloc_u32(&ht->handle_idr, NULL, &index, max, GFP_KERNEL)) {
                index = htid + 1;
                if (idr_alloc_u32(&ht->handle_idr, NULL, &index, max,
                                 GFP_KERNEL))
                        index = max;
        }

        return index;
}

static const struct nla_policy u32_policy[TCA_U32_MAX + 1] = {
        [TCA_U32_CLASSID]       = { .type = NLA_U32 },
        [TCA_U32_HASH]          = { .type = NLA_U32 },
        [TCA_U32_LINK]          = { .type = NLA_U32 },
        [TCA_U32_DIVISOR]       = { .type = NLA_U32 },
        [TCA_U32_SEL]           = { .len = sizeof(struct tc_u32_sel) },
        [TCA_U32_INDEV]         = { .type = NLA_STRING, .len = IFNAMSIZ },
        [TCA_U32_MARK]          = { .len = sizeof(struct tc_u32_mark) },
        [TCA_U32_FLAGS]         = { .type = NLA_U32 },
};

static void u32_unbind_filter(struct tcf_proto *tp, struct tc_u_knode *n,
                              struct nlattr **tb)
{
        if (tb[TCA_U32_CLASSID])
                tcf_unbind_filter(tp, &n->res);
}

static void u32_bind_filter(struct tcf_proto *tp, struct tc_u_knode *n,
                            unsigned long base, struct nlattr **tb)
{
        if (tb[TCA_U32_CLASSID]) {
                n->res.classid = nla_get_u32(tb[TCA_U32_CLASSID]);
                tcf_bind_filter(tp, &n->res, base);
        }
}

static int u32_set_parms(struct net *net, struct tcf_proto *tp,
                         struct tc_u_knode *n, struct nlattr **tb,
                         struct nlattr *est, u32 flags, u32 fl_flags,
                         struct netlink_ext_ack *extack)
{
        int err, ifindex = -1;

        err = tcf_exts_validate_ex(net, tp, tb, est, &n->exts, flags,
                                   fl_flags, extack);
        if (err < 0)
                return err;

        if (tb[TCA_U32_INDEV]) {
                ifindex = tcf_change_indev(net, tb[TCA_U32_INDEV], extack);
                if (ifindex < 0)
                        return -EINVAL;
        }

        if (tb[TCA_U32_LINK]) {
                u32 handle = nla_get_u32(tb[TCA_U32_LINK]);
                struct tc_u_hnode *ht_down = NULL, *ht_old;

                if (TC_U32_KEY(handle)) {
                        NL_SET_ERR_MSG_MOD(extack, "u32 Link handle must be a hash table");
                        return -EINVAL;
                }

                if (handle) {
                        ht_down = u32_lookup_ht(tp->data, handle);

                        if (!ht_down) {
                                NL_SET_ERR_MSG_MOD(extack, "Link hash table not found");
                                return -EINVAL;
                        }
                        if (ht_down->is_root) {
                                NL_SET_ERR_MSG_MOD(extack, "Not linking to root node");
                                return -EINVAL;
                        }
                        refcount_inc(&ht_down->refcnt);
                }

                ht_old = rtnl_dereference(n->ht_down);
                rcu_assign_pointer(n->ht_down, ht_down);

                if (ht_old)
                        refcount_dec(&ht_old->refcnt);
        }

        if (ifindex >= 0)
                n->ifindex = ifindex;

        return 0;
}

static void u32_replace_knode(struct tcf_proto *tp, struct tc_u_common *tp_c,
                              struct tc_u_knode *n)
{
        struct tc_u_knode __rcu **ins;
        struct tc_u_knode *pins;
        struct tc_u_hnode *ht;

        if (TC_U32_HTID(n->handle) == TC_U32_ROOT)
                ht = rtnl_dereference(tp->root);
        else
                ht = u32_lookup_ht(tp_c, TC_U32_HTID(n->handle));

        ins = &ht->ht[TC_U32_HASH(n->handle)];

        /* The node must always exist for it to be replaced if this is not the
         * case then something went very wrong elsewhere.
         */
        for (pins = rtnl_dereference(*ins); ;
             ins = &pins->next, pins = rtnl_dereference(*ins))
                if (pins->handle == n->handle)
                        break;

        idr_replace(&ht->handle_idr, n, n->handle);
        RCU_INIT_POINTER(n->next, pins->next);
        rcu_assign_pointer(*ins, n);
}

static struct tc_u_knode *u32_init_knode(struct net *net, struct tcf_proto *tp,
                                         struct tc_u_knode *n)
{
        struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);
        struct tc_u32_sel *s = &n->sel;
        struct tc_u_knode *new;

        new = kzalloc_flex(*new, sel.keys, s->nkeys);
        if (!new)
                return NULL;

        RCU_INIT_POINTER(new->next, n->next);
        new->handle = n->handle;
        RCU_INIT_POINTER(new->ht_up, n->ht_up);

        new->ifindex = n->ifindex;
        new->fshift = n->fshift;
        new->flags = n->flags;
        RCU_INIT_POINTER(new->ht_down, ht);

#ifdef CONFIG_CLS_U32_PERF
        /* Statistics may be incremented by readers during update
         * so we must keep them in tact. When the node is later destroyed
         * a special destroy call must be made to not free the pf memory.
         */
        new->pf = n->pf;
#endif

#ifdef CONFIG_CLS_U32_MARK
        new->val = n->val;
        new->mask = n->mask;
        /* Similarly success statistics must be moved as pointers */
        new->pcpu_success = n->pcpu_success;
#endif
        memcpy(&new->sel, s, struct_size(s, keys, s->nkeys));

        if (tcf_exts_init(&new->exts, net, TCA_U32_ACT, TCA_U32_POLICE)) {
                kfree(new);
                return NULL;
        }

        /* bump reference count as long as we hold pointer to structure */
        if (ht)
                refcount_inc(&ht->refcnt);

        return new;
}

static int u32_change(struct net *net, struct sk_buff *in_skb,
                      struct tcf_proto *tp, unsigned long base, u32 handle,
                      struct nlattr **tca, void **arg, u32 flags,
                      struct netlink_ext_ack *extack)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_hnode *ht;
        struct tc_u_knode *n;
        struct tc_u32_sel *s;
        struct nlattr *opt = tca[TCA_OPTIONS];
        struct nlattr *tb[TCA_U32_MAX + 1];
        u32 htid, userflags = 0;
        size_t sel_size;
        int err;

        if (!opt) {
                if (handle) {
                        NL_SET_ERR_MSG_MOD(extack, "Filter handle requires options");
                        return -EINVAL;
                } else {
                        return 0;
                }
        }

        err = nla_parse_nested_deprecated(tb, TCA_U32_MAX, opt, u32_policy,
                                          extack);
        if (err < 0)
                return err;

        if (tb[TCA_U32_FLAGS]) {
                userflags = nla_get_u32(tb[TCA_U32_FLAGS]);
                if (!tc_flags_valid(userflags)) {
                        NL_SET_ERR_MSG_MOD(extack, "Invalid filter flags");
                        return -EINVAL;
                }
        }

        n = *arg;
        if (n) {
                struct tc_u_knode *new;

                if (TC_U32_KEY(n->handle) == 0) {
                        NL_SET_ERR_MSG_MOD(extack, "Key node id cannot be zero");
                        return -EINVAL;
                }

                if ((n->flags ^ userflags) &
                    ~(TCA_CLS_FLAGS_IN_HW | TCA_CLS_FLAGS_NOT_IN_HW)) {
                        NL_SET_ERR_MSG_MOD(extack, "Key node flags do not match passed flags");
                        return -EINVAL;
                }

                new = u32_init_knode(net, tp, n);
                if (!new)
                        return -ENOMEM;

                err = u32_set_parms(net, tp, new, tb, tca[TCA_RATE],
                                    flags, new->flags, extack);

                if (err) {
                        __u32_destroy_key(new);
                        return err;
                }

                u32_bind_filter(tp, new, base, tb);

                err = u32_replace_hw_knode(tp, new, flags, extack);
                if (err) {
                        u32_unbind_filter(tp, new, tb);

                        if (tb[TCA_U32_LINK]) {
                                struct tc_u_hnode *ht_old;

                                ht_old = rtnl_dereference(n->ht_down);
                                if (ht_old)
                                        refcount_inc(&ht_old->refcnt);
                        }
                        __u32_destroy_key(new);
                        return err;
                }

                if (!tc_in_hw(new->flags))
                        new->flags |= TCA_CLS_FLAGS_NOT_IN_HW;

                tcf_proto_update_usesw(tp, new->flags);

                u32_replace_knode(tp, tp_c, new);
                tcf_unbind_filter(tp, &n->res);
                tcf_exts_get_net(&n->exts);
                tcf_queue_work(&n->rwork, u32_delete_key_work);
                return 0;
        }

        if (tb[TCA_U32_DIVISOR]) {
                unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);

                if (!is_power_of_2(divisor)) {
                        NL_SET_ERR_MSG_MOD(extack, "Divisor is not a power of 2");
                        return -EINVAL;
                }
                if (divisor-- > 0x100) {
                        NL_SET_ERR_MSG_MOD(extack, "Exceeded maximum 256 hash buckets");
                        return -EINVAL;
                }
                if (TC_U32_KEY(handle)) {
                        NL_SET_ERR_MSG_MOD(extack, "Divisor can only be used on a hash table");
                        return -EINVAL;
                }
                ht = kzalloc_flex(*ht, ht, divisor + 1);
                if (ht == NULL)
                        return -ENOBUFS;
                if (handle == 0) {
                        handle = gen_new_htid(tp->data, ht);
                        if (handle == 0) {
                                kfree(ht);
                                return -ENOMEM;
                        }
                } else {
                        err = idr_alloc_u32(&tp_c->handle_idr, ht, &handle,
                                            handle, GFP_KERNEL);
                        if (err) {
                                kfree(ht);
                                return err;
                        }
                }
                refcount_set(&ht->refcnt, 1);
                ht->divisor = divisor;
                ht->handle = handle;
                ht->prio = tp->prio;
                idr_init(&ht->handle_idr);
                ht->flags = userflags;

                err = u32_replace_hw_hnode(tp, ht, userflags, extack);
                if (err) {
                        idr_remove(&tp_c->handle_idr, handle2id(handle));
                        kfree(ht);
                        return err;
                }

                RCU_INIT_POINTER(ht->next, tp_c->hlist);
                rcu_assign_pointer(tp_c->hlist, ht);
                *arg = ht;

                return 0;
        }

        if (tb[TCA_U32_HASH]) {
                htid = nla_get_u32(tb[TCA_U32_HASH]);
                if (TC_U32_HTID(htid) == TC_U32_ROOT) {
                        ht = rtnl_dereference(tp->root);
                        htid = ht->handle;
                } else {
                        ht = u32_lookup_ht(tp->data, TC_U32_HTID(htid));
                        if (!ht) {
                                NL_SET_ERR_MSG_MOD(extack, "Specified hash table not found");
                                return -EINVAL;
                        }
                }
        } else {
                ht = rtnl_dereference(tp->root);
                htid = ht->handle;
        }

        if (ht->divisor < TC_U32_HASH(htid)) {
                NL_SET_ERR_MSG_MOD(extack, "Specified hash table buckets exceed configured value");
                return -EINVAL;
        }

        /* At this point, we need to derive the new handle that will be used to
         * uniquely map the identity of this table match entry. The
         * identity of the entry that we need to construct is 32 bits made of:
         *     htid(12b):bucketid(8b):node/entryid(12b)
         *
         * At this point _we have the table(ht)_ in which we will insert this
         * entry. We carry the table's id in variable "htid".
         * Note that earlier code picked the ht selection either by a) the user
         * providing the htid specified via TCA_U32_HASH attribute or b) when
         * no such attribute is passed then the root ht, is default to at ID
         * 0x[800][00][000]. Rule: the root table has a single bucket with ID 0.
         * If OTOH the user passed us the htid, they may also pass a bucketid of
         * choice. 0 is fine. For example a user htid is 0x[600][01][000] it is
         * indicating hash bucketid of 1. Rule: the entry/node ID _cannot_ be
         * passed via the htid, so even if it was non-zero it will be ignored.
         *
         * We may also have a handle, if the user passed one. The handle also
         * carries the same addressing of htid(12b):bucketid(8b):node/entryid(12b).
         * Rule: the bucketid on the handle is ignored even if one was passed;
         * rather the value on "htid" is always assumed to be the bucketid.
         */
        if (handle) {
                /* Rule: The htid from handle and tableid from htid must match */
                if (TC_U32_HTID(handle) && TC_U32_HTID(handle ^ htid)) {
                        NL_SET_ERR_MSG_MOD(extack, "Handle specified hash table address mismatch");
                        return -EINVAL;
                }
                /* Ok, so far we have a valid htid(12b):bucketid(8b) but we
                 * need to finalize the table entry identification with the last
                 * part - the node/entryid(12b)). Rule: Nodeid _cannot be 0_ for
                 * entries. Rule: nodeid of 0 is reserved only for tables(see
                 * earlier code which processes TC_U32_DIVISOR attribute).
                 * Rule: The nodeid can only be derived from the handle (and not
                 * htid).
                 * Rule: if the handle specified zero for the node id example
                 * 0x60000000, then pick a new nodeid from the pool of IDs
                 * this hash table has been allocating from.
                 * If OTOH it is specified (i.e for example the user passed a
                 * handle such as 0x60000123), then we use it generate our final
                 * handle which is used to uniquely identify the match entry.
                 */
                if (!TC_U32_NODE(handle)) {
                        handle = gen_new_kid(ht, htid);
                } else {
                        handle = htid | TC_U32_NODE(handle);
                        err = idr_alloc_u32(&ht->handle_idr, NULL, &handle,
                                            handle, GFP_KERNEL);
                        if (err)
                                return err;
                }
        } else {
                /* The user did not give us a handle; lets just generate one
                 * from the table's pool of nodeids.
                 */
                handle = gen_new_kid(ht, htid);
        }

        if (tb[TCA_U32_SEL] == NULL) {
                NL_SET_ERR_MSG_MOD(extack, "Selector not specified");
                err = -EINVAL;
                goto erridr;
        }

        s = nla_data(tb[TCA_U32_SEL]);
        sel_size = struct_size(s, keys, s->nkeys);
        if (nla_len(tb[TCA_U32_SEL]) < sel_size) {
                err = -EINVAL;
                goto erridr;
        }

        n = kzalloc_flex(*n, sel.keys, s->nkeys);
        if (n == NULL) {
                err = -ENOBUFS;
                goto erridr;
        }

#ifdef CONFIG_CLS_U32_PERF
        n->pf = __alloc_percpu(struct_size(n->pf, kcnts, s->nkeys),
                               __alignof__(struct tc_u32_pcnt));
        if (!n->pf) {
                err = -ENOBUFS;
                goto errfree;
        }
#endif

        unsafe_memcpy(&n->sel, s, sel_size,
                      /* A composite flex-array structure destination,
                       * which was correctly sized with struct_size(),
                       * bounds-checked against nla_len(), and allocated
                       * above. */);
        RCU_INIT_POINTER(n->ht_up, ht);
        n->handle = handle;
        n->fshift = s->hmask ? ffs(ntohl(s->hmask)) - 1 : 0;
        n->flags = userflags;

        err = tcf_exts_init(&n->exts, net, TCA_U32_ACT, TCA_U32_POLICE);
        if (err < 0)
                goto errout;

#ifdef CONFIG_CLS_U32_MARK
        n->pcpu_success = alloc_percpu(u32);
        if (!n->pcpu_success) {
                err = -ENOMEM;
                goto errout;
        }

        if (tb[TCA_U32_MARK]) {
                struct tc_u32_mark *mark;

                mark = nla_data(tb[TCA_U32_MARK]);
                n->val = mark->val;
                n->mask = mark->mask;
        }
#endif

        err = u32_set_parms(net, tp, n, tb, tca[TCA_RATE],
                            flags, n->flags, extack);

        u32_bind_filter(tp, n, base, tb);

        if (err == 0) {
                struct tc_u_knode __rcu **ins;
                struct tc_u_knode *pins;

                err = u32_replace_hw_knode(tp, n, flags, extack);
                if (err)
                        goto errunbind;

                if (!tc_in_hw(n->flags))
                        n->flags |= TCA_CLS_FLAGS_NOT_IN_HW;

                tcf_proto_update_usesw(tp, n->flags);

                ins = &ht->ht[TC_U32_HASH(handle)];
                for (pins = rtnl_dereference(*ins); pins;
                     ins = &pins->next, pins = rtnl_dereference(*ins))
                        if (TC_U32_NODE(handle) < TC_U32_NODE(pins->handle))
                                break;

                RCU_INIT_POINTER(n->next, pins);
                rcu_assign_pointer(*ins, n);
                tp_c->knodes++;
                *arg = n;
                return 0;
        }

errunbind:
        u32_unbind_filter(tp, n, tb);

#ifdef CONFIG_CLS_U32_MARK
        free_percpu(n->pcpu_success);
#endif

errout:
        tcf_exts_destroy(&n->exts);
#ifdef CONFIG_CLS_U32_PERF
errfree:
        free_percpu(n->pf);
#endif
        kfree(n);
erridr:
        idr_remove(&ht->handle_idr, handle);
        return err;
}

static void u32_walk(struct tcf_proto *tp, struct tcf_walker *arg,
                     bool rtnl_held)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_hnode *ht;
        struct tc_u_knode *n;
        unsigned int h;

        if (arg->stop)
                return;

        for (ht = rtnl_dereference(tp_c->hlist);
             ht;
             ht = rtnl_dereference(ht->next)) {
                if (ht->prio != tp->prio)
                        continue;

                if (!tc_cls_stats_dump(tp, arg, ht))
                        return;

                for (h = 0; h <= ht->divisor; h++) {
                        for (n = rtnl_dereference(ht->ht[h]);
                             n;
                             n = rtnl_dereference(n->next)) {
                                if (!tc_cls_stats_dump(tp, arg, n))
                                        return;
                        }
                }
        }
}

static int u32_reoffload_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht,
                               bool add, flow_setup_cb_t *cb, void *cb_priv,
                               struct netlink_ext_ack *extack)
{
        struct tc_cls_u32_offload cls_u32 = {};
        int err;

        tc_cls_common_offload_init(&cls_u32.common, tp, ht->flags, extack);
        cls_u32.command = add ? TC_CLSU32_NEW_HNODE : TC_CLSU32_DELETE_HNODE;
        cls_u32.hnode.divisor = ht->divisor;
        cls_u32.hnode.handle = ht->handle;
        cls_u32.hnode.prio = ht->prio;

        err = cb(TC_SETUP_CLSU32, &cls_u32, cb_priv);
        if (err && add && tc_skip_sw(ht->flags))
                return err;

        return 0;
}

static int u32_reoffload_knode(struct tcf_proto *tp, struct tc_u_knode *n,
                               bool add, flow_setup_cb_t *cb, void *cb_priv,
                               struct netlink_ext_ack *extack)
{
        struct tc_u_hnode *ht = rtnl_dereference(n->ht_down);
        struct tcf_block *block = tp->chain->block;
        struct tc_cls_u32_offload cls_u32 = {};

        tc_cls_common_offload_init(&cls_u32.common, tp, n->flags, extack);
        cls_u32.command = add ?
                TC_CLSU32_REPLACE_KNODE : TC_CLSU32_DELETE_KNODE;
        cls_u32.knode.handle = n->handle;

        if (add) {
                cls_u32.knode.fshift = n->fshift;
#ifdef CONFIG_CLS_U32_MARK
                cls_u32.knode.val = n->val;
                cls_u32.knode.mask = n->mask;
#else
                cls_u32.knode.val = 0;
                cls_u32.knode.mask = 0;
#endif
                cls_u32.knode.sel = &n->sel;
                cls_u32.knode.res = &n->res;
                cls_u32.knode.exts = &n->exts;
                if (n->ht_down)
                        cls_u32.knode.link_handle = ht->handle;
        }

        return tc_setup_cb_reoffload(block, tp, add, cb, TC_SETUP_CLSU32,
                                     &cls_u32, cb_priv, &n->flags,
                                     &n->in_hw_count);
}

static int u32_reoffload(struct tcf_proto *tp, bool add, flow_setup_cb_t *cb,
                         void *cb_priv, struct netlink_ext_ack *extack)
{
        struct tc_u_common *tp_c = tp->data;
        struct tc_u_hnode *ht;
        struct tc_u_knode *n;
        unsigned int h;
        int err;

        for (ht = rtnl_dereference(tp_c->hlist);
             ht;
             ht = rtnl_dereference(ht->next)) {
                if (ht->prio != tp->prio)
                        continue;

                /* When adding filters to a new dev, try to offload the
                 * hashtable first. When removing, do the filters before the
                 * hashtable.
                 */
                if (add && !tc_skip_hw(ht->flags)) {
                        err = u32_reoffload_hnode(tp, ht, add, cb, cb_priv,
                                                  extack);
                        if (err)
                                return err;
                }

                for (h = 0; h <= ht->divisor; h++) {
                        for (n = rtnl_dereference(ht->ht[h]);
                             n;
                             n = rtnl_dereference(n->next)) {
                                if (tc_skip_hw(n->flags))
                                        continue;

                                err = u32_reoffload_knode(tp, n, add, cb,
                                                          cb_priv, extack);
                                if (err)
                                        return err;
                        }
                }

                if (!add && !tc_skip_hw(ht->flags))
                        u32_reoffload_hnode(tp, ht, add, cb, cb_priv, extack);
        }

        return 0;
}

static void u32_bind_class(void *fh, u32 classid, unsigned long cl, void *q,
                           unsigned long base)
{
        struct tc_u_knode *n = fh;

        tc_cls_bind_class(classid, cl, q, &n->res, base);
}

static int u32_dump(struct net *net, struct tcf_proto *tp, void *fh,
                    struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
{
        struct tc_u_knode *n = fh;
        struct tc_u_hnode *ht_up, *ht_down;
        struct nlattr *nest;

        if (n == NULL)
                return skb->len;

        t->tcm_handle = n->handle;

        nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
        if (nest == NULL)
                goto nla_put_failure;

        if (TC_U32_KEY(n->handle) == 0) {
                struct tc_u_hnode *ht = fh;
                u32 divisor = ht->divisor + 1;

                if (nla_put_u32(skb, TCA_U32_DIVISOR, divisor))
                        goto nla_put_failure;
        } else {
#ifdef CONFIG_CLS_U32_PERF
                struct tc_u32_pcnt *gpf;
                int cpu;
#endif

                if (nla_put(skb, TCA_U32_SEL, struct_size(&n->sel, keys, n->sel.nkeys),
                            &n->sel))
                        goto nla_put_failure;

                ht_up = rtnl_dereference(n->ht_up);
                if (ht_up) {
                        u32 htid = n->handle & 0xFFFFF000;
                        if (nla_put_u32(skb, TCA_U32_HASH, htid))
                                goto nla_put_failure;
                }
                if (n->res.classid &&
                    nla_put_u32(skb, TCA_U32_CLASSID, n->res.classid))
                        goto nla_put_failure;

                ht_down = rtnl_dereference(n->ht_down);
                if (ht_down &&
                    nla_put_u32(skb, TCA_U32_LINK, ht_down->handle))
                        goto nla_put_failure;

                if (n->flags && nla_put_u32(skb, TCA_U32_FLAGS, n->flags))
                        goto nla_put_failure;

#ifdef CONFIG_CLS_U32_MARK
                if ((n->val || n->mask)) {
                        struct tc_u32_mark mark = {.val = n->val,
                                                   .mask = n->mask,
                                                   .success = 0};
                        int cpum;

                        for_each_possible_cpu(cpum) {
                                __u32 cnt = *per_cpu_ptr(n->pcpu_success, cpum);

                                mark.success += cnt;
                        }

                        if (nla_put(skb, TCA_U32_MARK, sizeof(mark), &mark))
                                goto nla_put_failure;
                }
#endif

                if (tcf_exts_dump(skb, &n->exts) < 0)
                        goto nla_put_failure;

                if (n->ifindex) {
                        struct net_device *dev;
                        dev = __dev_get_by_index(net, n->ifindex);
                        if (dev && nla_put_string(skb, TCA_U32_INDEV, dev->name))
                                goto nla_put_failure;
                }
#ifdef CONFIG_CLS_U32_PERF
                gpf = kzalloc_flex(*gpf, kcnts, n->sel.nkeys);
                if (!gpf)
                        goto nla_put_failure;

                for_each_possible_cpu(cpu) {
                        int i;
                        struct tc_u32_pcnt *pf = per_cpu_ptr(n->pf, cpu);

                        gpf->rcnt += pf->rcnt;
                        gpf->rhit += pf->rhit;
                        for (i = 0; i < n->sel.nkeys; i++)
                                gpf->kcnts[i] += pf->kcnts[i];
                }

                if (nla_put_64bit(skb, TCA_U32_PCNT, struct_size(gpf, kcnts, n->sel.nkeys),
                                  gpf, TCA_U32_PAD)) {
                        kfree(gpf);
                        goto nla_put_failure;
                }
                kfree(gpf);
#endif
        }

        nla_nest_end(skb, nest);

        if (TC_U32_KEY(n->handle))
                if (tcf_exts_dump_stats(skb, &n->exts) < 0)
                        goto nla_put_failure;
        return skb->len;

nla_put_failure:
        nla_nest_cancel(skb, nest);
        return -1;
}

static struct tcf_proto_ops cls_u32_ops __read_mostly = {
        .kind           =       "u32",
        .classify       =       u32_classify,
        .init           =       u32_init,
        .destroy        =       u32_destroy,
        .get            =       u32_get,
        .change         =       u32_change,
        .delete         =       u32_delete,
        .walk           =       u32_walk,
        .reoffload      =       u32_reoffload,
        .dump           =       u32_dump,
        .bind_class     =       u32_bind_class,
        .owner          =       THIS_MODULE,
};
MODULE_ALIAS_NET_CLS("u32");

static int __init init_u32(void)
{
        int i, ret;

        pr_info("u32 classifier\n");
#ifdef CONFIG_CLS_U32_PERF
        pr_info("    Performance counters on\n");
#endif
        pr_info("    input device check on\n");
#ifdef CONFIG_NET_CLS_ACT
        pr_info("    Actions configured\n");
#endif
        tc_u_common_hash = kvmalloc_objs(struct hlist_head, U32_HASH_SIZE);
        if (!tc_u_common_hash)
                return -ENOMEM;

        for (i = 0; i < U32_HASH_SIZE; i++)
                INIT_HLIST_HEAD(&tc_u_common_hash[i]);

        ret = register_tcf_proto_ops(&cls_u32_ops);
        if (ret)
                kvfree(tc_u_common_hash);
        return ret;
}

static void __exit exit_u32(void)
{
        unregister_tcf_proto_ops(&cls_u32_ops);
        kvfree(tc_u_common_hash);
}

module_init(init_u32)
module_exit(exit_u32)
MODULE_DESCRIPTION("Universal 32bit based TC Classifier");
MODULE_LICENSE("GPL");