Merge remote-tracking branch 'regulator/topic/palmas' into v3.9-rc8

[mirror_ubuntu-hirsute-kernel.git] / include / linux / netfilter / ipset / ip_set_ahash.h

#ifndef _IP_SET_AHASH_H
#define _IP_SET_AHASH_H

#include <linux/rcupdate.h>
#include <linux/jhash.h>
#include <linux/netfilter/ipset/ip_set_timeout.h>

#define CONCAT(a, b, c)         a##b##c
#define TOKEN(a, b, c)          CONCAT(a, b, c)

#define type_pf_next            TOKEN(TYPE, PF, _elem)

/* Hashing which uses arrays to resolve clashing. The hash table is resized
 * (doubled) when searching becomes too long.
 * Internally jhash is used with the assumption that the size of the
 * stored data is a multiple of sizeof(u32). If storage supports timeout,
 * the timeout field must be the last one in the data structure - that field
 * is ignored when computing the hash key.
 *
 * Readers and resizing
 *
 * Resizing can be triggered by userspace command only, and those
 * are serialized by the nfnl mutex. During resizing the set is
 * read-locked, so the only possible concurrent operations are
 * the kernel side readers. Those must be protected by proper RCU locking.
 */

/* Number of elements to store in an initial array block */
#define AHASH_INIT_SIZE                 4
/* Max number of elements to store in an array block */
#define AHASH_MAX_SIZE                  (3*AHASH_INIT_SIZE)

/* Max number of elements can be tuned */
#ifdef IP_SET_HASH_WITH_MULTI
#define AHASH_MAX(h)                    ((h)->ahash_max)

static inline u8
tune_ahash_max(u8 curr, u32 multi)
{
        u32 n;

        if (multi < curr)
                return curr;

        n = curr + AHASH_INIT_SIZE;
        /* Currently, at listing one hash bucket must fit into a message.
         * Therefore we have a hard limit here.
         */
        return n > curr && n <= 64 ? n : curr;
}
#define TUNE_AHASH_MAX(h, multi)        \
        ((h)->ahash_max = tune_ahash_max((h)->ahash_max, multi))
#else
#define AHASH_MAX(h)                    AHASH_MAX_SIZE
#define TUNE_AHASH_MAX(h, multi)
#endif

/* A hash bucket */
struct hbucket {
        void *value;            /* the array of the values */
        u8 size;                /* size of the array */
        u8 pos;                 /* position of the first free entry */
};

/* The hash table: the table size stored here in order to make resizing easy */
struct htable {
        u8 htable_bits;         /* size of hash table == 2^htable_bits */
        struct hbucket bucket[0]; /* hashtable buckets */
};

#define hbucket(h, i)           (&((h)->bucket[i]))

/* Book-keeping of the prefixes added to the set */
struct ip_set_hash_nets {
        u8 cidr;                /* the different cidr values in the set */
        u32 nets;               /* number of elements per cidr */
};

/* The generic ip_set hash structure */
struct ip_set_hash {
        struct htable *table;   /* the hash table */
        u32 maxelem;            /* max elements in the hash */
        u32 elements;           /* current element (vs timeout) */
        u32 initval;            /* random jhash init value */
        u32 timeout;            /* timeout value, if enabled */
        struct timer_list gc;   /* garbage collection when timeout enabled */
        struct type_pf_next next; /* temporary storage for uadd */
#ifdef IP_SET_HASH_WITH_MULTI
        u8 ahash_max;           /* max elements in an array block */
#endif
#ifdef IP_SET_HASH_WITH_NETMASK
        u8 netmask;             /* netmask value for subnets to store */
#endif
#ifdef IP_SET_HASH_WITH_RBTREE
        struct rb_root rbtree;
#endif
#ifdef IP_SET_HASH_WITH_NETS
        struct ip_set_hash_nets nets[0]; /* book-keeping of prefixes */
#endif
};

static size_t
htable_size(u8 hbits)
{
        size_t hsize;

        /* We must fit both into u32 in jhash and size_t */
        if (hbits > 31)
                return 0;
        hsize = jhash_size(hbits);
        if ((((size_t)-1) - sizeof(struct htable))/sizeof(struct hbucket)
            < hsize)
                return 0;

        return hsize * sizeof(struct hbucket) + sizeof(struct htable);
}

/* Compute htable_bits from the user input parameter hashsize */
static u8
htable_bits(u32 hashsize)
{
        /* Assume that hashsize == 2^htable_bits */
        u8 bits = fls(hashsize - 1);
        if (jhash_size(bits) != hashsize)
                /* Round up to the first 2^n value */
                bits = fls(hashsize);

        return bits;
}

#ifdef IP_SET_HASH_WITH_NETS
#ifdef IP_SET_HASH_WITH_NETS_PACKED
/* When cidr is packed with nomatch, cidr - 1 is stored in the entry */
#define CIDR(cidr)      (cidr + 1)
#else
#define CIDR(cidr)      (cidr)
#endif

#define SET_HOST_MASK(family)   (family == AF_INET ? 32 : 128)
#ifdef IP_SET_HASH_WITH_MULTI
#define NETS_LENGTH(family)     (SET_HOST_MASK(family) + 1)
#else
#define NETS_LENGTH(family)     SET_HOST_MASK(family)
#endif

/* Network cidr size book keeping when the hash stores different
 * sized networks */
static void
add_cidr(struct ip_set_hash *h, u8 cidr, u8 nets_length)
{
        int i, j;

        /* Add in increasing prefix order, so larger cidr first */
        for (i = 0, j = -1; i < nets_length && h->nets[i].nets; i++) {
                if (j != -1)
                        continue;
                else if (h->nets[i].cidr < cidr)
                        j = i;
                else if (h->nets[i].cidr == cidr) {
                        h->nets[i].nets++;
                        return;
                }
        }
        if (j != -1) {
                for (; i > j; i--) {
                        h->nets[i].cidr = h->nets[i - 1].cidr;
                        h->nets[i].nets = h->nets[i - 1].nets;
                }
        }
        h->nets[i].cidr = cidr;
        h->nets[i].nets = 1;
}

static void
del_cidr(struct ip_set_hash *h, u8 cidr, u8 nets_length)
{
        u8 i, j;

        for (i = 0; i < nets_length - 1 && h->nets[i].cidr != cidr; i++)
                ;
        h->nets[i].nets--;

        if (h->nets[i].nets != 0)
                return;

        for (j = i; j < nets_length - 1 && h->nets[j].nets; j++) {
                h->nets[j].cidr = h->nets[j + 1].cidr;
                h->nets[j].nets = h->nets[j + 1].nets;
        }
}
#else
#define NETS_LENGTH(family)             0
#endif

/* Destroy the hashtable part of the set */
static void
ahash_destroy(struct htable *t)
{
        struct hbucket *n;
        u32 i;

        for (i = 0; i < jhash_size(t->htable_bits); i++) {
                n = hbucket(t, i);
                if (n->size)
                        /* FIXME: use slab cache */
                        kfree(n->value);
        }

        ip_set_free(t);
}

/* Calculate the actual memory size of the set data */
static size_t
ahash_memsize(const struct ip_set_hash *h, size_t dsize, u8 nets_length)
{
        u32 i;
        struct htable *t = h->table;
        size_t memsize = sizeof(*h)
                         + sizeof(*t)
#ifdef IP_SET_HASH_WITH_NETS
                         + sizeof(struct ip_set_hash_nets) * nets_length
#endif
                         + jhash_size(t->htable_bits) * sizeof(struct hbucket);

        for (i = 0; i < jhash_size(t->htable_bits); i++)
                        memsize += t->bucket[i].size * dsize;

        return memsize;
}

/* Flush a hash type of set: destroy all elements */
static void
ip_set_hash_flush(struct ip_set *set)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        struct hbucket *n;
        u32 i;

        for (i = 0; i < jhash_size(t->htable_bits); i++) {
                n = hbucket(t, i);
                if (n->size) {
                        n->size = n->pos = 0;
                        /* FIXME: use slab cache */
                        kfree(n->value);
                }
        }
#ifdef IP_SET_HASH_WITH_NETS
        memset(h->nets, 0, sizeof(struct ip_set_hash_nets)
                           * NETS_LENGTH(set->family));
#endif
        h->elements = 0;
}

/* Destroy a hash type of set */
static void
ip_set_hash_destroy(struct ip_set *set)
{
        struct ip_set_hash *h = set->data;

        if (with_timeout(h->timeout))
                del_timer_sync(&h->gc);

        ahash_destroy(h->table);
#ifdef IP_SET_HASH_WITH_RBTREE
        rbtree_destroy(&h->rbtree);
#endif
        kfree(h);

        set->data = NULL;
}

#endif /* _IP_SET_AHASH_H */

#ifndef HKEY_DATALEN
#define HKEY_DATALEN    sizeof(struct type_pf_elem)
#endif

#define HKEY(data, initval, htable_bits)                        \
(jhash2((u32 *)(data), HKEY_DATALEN/sizeof(u32), initval)       \
        & jhash_mask(htable_bits))

/* Type/family dependent function prototypes */

#define type_pf_data_equal      TOKEN(TYPE, PF, _data_equal)
#define type_pf_data_isnull     TOKEN(TYPE, PF, _data_isnull)
#define type_pf_data_copy       TOKEN(TYPE, PF, _data_copy)
#define type_pf_data_zero_out   TOKEN(TYPE, PF, _data_zero_out)
#define type_pf_data_netmask    TOKEN(TYPE, PF, _data_netmask)
#define type_pf_data_list       TOKEN(TYPE, PF, _data_list)
#define type_pf_data_tlist      TOKEN(TYPE, PF, _data_tlist)
#define type_pf_data_next       TOKEN(TYPE, PF, _data_next)
#define type_pf_data_flags      TOKEN(TYPE, PF, _data_flags)
#define type_pf_data_reset_flags TOKEN(TYPE, PF, _data_reset_flags)
#ifdef IP_SET_HASH_WITH_NETS
#define type_pf_data_match      TOKEN(TYPE, PF, _data_match)
#else
#define type_pf_data_match(d)   1
#endif

#define type_pf_elem            TOKEN(TYPE, PF, _elem)
#define type_pf_telem           TOKEN(TYPE, PF, _telem)
#define type_pf_data_timeout    TOKEN(TYPE, PF, _data_timeout)
#define type_pf_data_expired    TOKEN(TYPE, PF, _data_expired)
#define type_pf_data_timeout_set TOKEN(TYPE, PF, _data_timeout_set)

#define type_pf_elem_add        TOKEN(TYPE, PF, _elem_add)
#define type_pf_add             TOKEN(TYPE, PF, _add)
#define type_pf_del             TOKEN(TYPE, PF, _del)
#define type_pf_test_cidrs      TOKEN(TYPE, PF, _test_cidrs)
#define type_pf_test            TOKEN(TYPE, PF, _test)

#define type_pf_elem_tadd       TOKEN(TYPE, PF, _elem_tadd)
#define type_pf_del_telem       TOKEN(TYPE, PF, _ahash_del_telem)
#define type_pf_expire          TOKEN(TYPE, PF, _expire)
#define type_pf_tadd            TOKEN(TYPE, PF, _tadd)
#define type_pf_tdel            TOKEN(TYPE, PF, _tdel)
#define type_pf_ttest_cidrs     TOKEN(TYPE, PF, _ahash_ttest_cidrs)
#define type_pf_ttest           TOKEN(TYPE, PF, _ahash_ttest)

#define type_pf_resize          TOKEN(TYPE, PF, _resize)
#define type_pf_tresize         TOKEN(TYPE, PF, _tresize)
#define type_pf_flush           ip_set_hash_flush
#define type_pf_destroy         ip_set_hash_destroy
#define type_pf_head            TOKEN(TYPE, PF, _head)
#define type_pf_list            TOKEN(TYPE, PF, _list)
#define type_pf_tlist           TOKEN(TYPE, PF, _tlist)
#define type_pf_same_set        TOKEN(TYPE, PF, _same_set)
#define type_pf_kadt            TOKEN(TYPE, PF, _kadt)
#define type_pf_uadt            TOKEN(TYPE, PF, _uadt)
#define type_pf_gc              TOKEN(TYPE, PF, _gc)
#define type_pf_gc_init         TOKEN(TYPE, PF, _gc_init)
#define type_pf_variant         TOKEN(TYPE, PF, _variant)
#define type_pf_tvariant        TOKEN(TYPE, PF, _tvariant)

/* Flavour without timeout */

/* Get the ith element from the array block n */
#define ahash_data(n, i)        \
        ((struct type_pf_elem *)((n)->value) + (i))

/* Add an element to the hash table when resizing the set:
 * we spare the maintenance of the internal counters. */
static int
type_pf_elem_add(struct hbucket *n, const struct type_pf_elem *value,
                 u8 ahash_max, u32 cadt_flags)
{
        struct type_pf_elem *data;

        if (n->pos >= n->size) {
                void *tmp;

                if (n->size >= ahash_max)
                        /* Trigger rehashing */
                        return -EAGAIN;

                tmp = kzalloc((n->size + AHASH_INIT_SIZE)
                              * sizeof(struct type_pf_elem),
                              GFP_ATOMIC);
                if (!tmp)
                        return -ENOMEM;
                if (n->size) {
                        memcpy(tmp, n->value,
                               sizeof(struct type_pf_elem) * n->size);
                        kfree(n->value);
                }
                n->value = tmp;
                n->size += AHASH_INIT_SIZE;
        }
        data = ahash_data(n, n->pos++);
        type_pf_data_copy(data, value);
#ifdef IP_SET_HASH_WITH_NETS
        /* Resizing won't overwrite stored flags */
        if (cadt_flags)
                type_pf_data_flags(data, cadt_flags);
#endif
        return 0;
}

/* Resize a hash: create a new hash table with doubling the hashsize
 * and inserting the elements to it. Repeat until we succeed or
 * fail due to memory pressures. */
static int
type_pf_resize(struct ip_set *set, bool retried)
{
        struct ip_set_hash *h = set->data;
        struct htable *t, *orig = h->table;
        u8 htable_bits = orig->htable_bits;
        struct type_pf_elem *data;
        struct hbucket *n, *m;
        u32 i, j, flags = 0;
        int ret;

retry:
        ret = 0;
        htable_bits++;
        pr_debug("attempt to resize set %s from %u to %u, t %p\n",
                 set->name, orig->htable_bits, htable_bits, orig);
        if (!htable_bits) {
                /* In case we have plenty of memory :-) */
                pr_warning("Cannot increase the hashsize of set %s further\n",
                           set->name);
                return -IPSET_ERR_HASH_FULL;
        }
        t = ip_set_alloc(sizeof(*t)
                         + jhash_size(htable_bits) * sizeof(struct hbucket));
        if (!t)
                return -ENOMEM;
        t->htable_bits = htable_bits;

        read_lock_bh(&set->lock);
        for (i = 0; i < jhash_size(orig->htable_bits); i++) {
                n = hbucket(orig, i);
                for (j = 0; j < n->pos; j++) {
                        data = ahash_data(n, j);
#ifdef IP_SET_HASH_WITH_NETS
                        flags = 0;
                        type_pf_data_reset_flags(data, &flags);
#endif
                        m = hbucket(t, HKEY(data, h->initval, htable_bits));
                        ret = type_pf_elem_add(m, data, AHASH_MAX(h), flags);
                        if (ret < 0) {
#ifdef IP_SET_HASH_WITH_NETS
                                type_pf_data_flags(data, flags);
#endif
                                read_unlock_bh(&set->lock);
                                ahash_destroy(t);
                                if (ret == -EAGAIN)
                                        goto retry;
                                return ret;
                        }
                }
        }

        rcu_assign_pointer(h->table, t);
        read_unlock_bh(&set->lock);

        /* Give time to other readers of the set */
        synchronize_rcu_bh();

        pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name,
                 orig->htable_bits, orig, t->htable_bits, t);
        ahash_destroy(orig);

        return 0;
}

static inline void
type_pf_data_next(struct ip_set_hash *h, const struct type_pf_elem *d);

/* Add an element to a hash and update the internal counters when succeeded,
 * otherwise report the proper error code. */
static int
type_pf_add(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
        struct ip_set_hash *h = set->data;
        struct htable *t;
        const struct type_pf_elem *d = value;
        struct hbucket *n;
        int i, ret = 0;
        u32 key, multi = 0;
        u32 cadt_flags = flags >> 16;

        if (h->elements >= h->maxelem) {
                if (net_ratelimit())
                        pr_warning("Set %s is full, maxelem %u reached\n",
                                   set->name, h->maxelem);
                return -IPSET_ERR_HASH_FULL;
        }

        rcu_read_lock_bh();
        t = rcu_dereference_bh(h->table);
        key = HKEY(value, h->initval, t->htable_bits);
        n = hbucket(t, key);
        for (i = 0; i < n->pos; i++)
                if (type_pf_data_equal(ahash_data(n, i), d, &multi)) {
#ifdef IP_SET_HASH_WITH_NETS
                        if (flags & IPSET_FLAG_EXIST)
                                /* Support overwriting just the flags */
                                type_pf_data_flags(ahash_data(n, i),
                                                   cadt_flags);
#endif
                        ret = -IPSET_ERR_EXIST;
                        goto out;
                }
        TUNE_AHASH_MAX(h, multi);
        ret = type_pf_elem_add(n, value, AHASH_MAX(h), cadt_flags);
        if (ret != 0) {
                if (ret == -EAGAIN)
                        type_pf_data_next(h, d);
                goto out;
        }

#ifdef IP_SET_HASH_WITH_NETS
        add_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
#endif
        h->elements++;
out:
        rcu_read_unlock_bh();
        return ret;
}

/* Delete an element from the hash: swap it with the last element
 * and free up space if possible.
 */
static int
type_pf_del(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        const struct type_pf_elem *d = value;
        struct hbucket *n;
        int i;
        struct type_pf_elem *data;
        u32 key, multi = 0;

        key = HKEY(value, h->initval, t->htable_bits);
        n = hbucket(t, key);
        for (i = 0; i < n->pos; i++) {
                data = ahash_data(n, i);
                if (!type_pf_data_equal(data, d, &multi))
                        continue;
                if (i != n->pos - 1)
                        /* Not last one */
                        type_pf_data_copy(data, ahash_data(n, n->pos - 1));

                n->pos--;
                h->elements--;
#ifdef IP_SET_HASH_WITH_NETS
                del_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
#endif
                if (n->pos + AHASH_INIT_SIZE < n->size) {
                        void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
                                            * sizeof(struct type_pf_elem),
                                            GFP_ATOMIC);
                        if (!tmp)
                                return 0;
                        n->size -= AHASH_INIT_SIZE;
                        memcpy(tmp, n->value,
                               n->size * sizeof(struct type_pf_elem));
                        kfree(n->value);
                        n->value = tmp;
                }
                return 0;
        }

        return -IPSET_ERR_EXIST;
}

#ifdef IP_SET_HASH_WITH_NETS

/* Special test function which takes into account the different network
 * sizes added to the set */
static int
type_pf_test_cidrs(struct ip_set *set, struct type_pf_elem *d, u32 timeout)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        struct hbucket *n;
        const struct type_pf_elem *data;
        int i, j = 0;
        u32 key, multi = 0;
        u8 nets_length = NETS_LENGTH(set->family);

        pr_debug("test by nets\n");
        for (; j < nets_length && h->nets[j].nets && !multi; j++) {
                type_pf_data_netmask(d, h->nets[j].cidr);
                key = HKEY(d, h->initval, t->htable_bits);
                n = hbucket(t, key);
                for (i = 0; i < n->pos; i++) {
                        data = ahash_data(n, i);
                        if (type_pf_data_equal(data, d, &multi))
                                return type_pf_data_match(data);
                }
        }
        return 0;
}
#endif

/* Test whether the element is added to the set */
static int
type_pf_test(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        struct type_pf_elem *d = value;
        struct hbucket *n;
        const struct type_pf_elem *data;
        int i;
        u32 key, multi = 0;

#ifdef IP_SET_HASH_WITH_NETS
        /* If we test an IP address and not a network address,
         * try all possible network sizes */
        if (CIDR(d->cidr) == SET_HOST_MASK(set->family))
                return type_pf_test_cidrs(set, d, timeout);
#endif

        key = HKEY(d, h->initval, t->htable_bits);
        n = hbucket(t, key);
        for (i = 0; i < n->pos; i++) {
                data = ahash_data(n, i);
                if (type_pf_data_equal(data, d, &multi))
                        return type_pf_data_match(data);
        }
        return 0;
}

/* Reply a HEADER request: fill out the header part of the set */
static int
type_pf_head(struct ip_set *set, struct sk_buff *skb)
{
        const struct ip_set_hash *h = set->data;
        struct nlattr *nested;
        size_t memsize;

        read_lock_bh(&set->lock);
        memsize = ahash_memsize(h, with_timeout(h->timeout)
                                        ? sizeof(struct type_pf_telem)
                                        : sizeof(struct type_pf_elem),
                                NETS_LENGTH(set->family));
        read_unlock_bh(&set->lock);

        nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
        if (!nested)
                goto nla_put_failure;
        if (nla_put_net32(skb, IPSET_ATTR_HASHSIZE,
                          htonl(jhash_size(h->table->htable_bits))) ||
            nla_put_net32(skb, IPSET_ATTR_MAXELEM, htonl(h->maxelem)))
                goto nla_put_failure;
#ifdef IP_SET_HASH_WITH_NETMASK
        if (h->netmask != HOST_MASK &&
            nla_put_u8(skb, IPSET_ATTR_NETMASK, h->netmask))
                goto nla_put_failure;
#endif
        if (nla_put_net32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1)) ||
            nla_put_net32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize)) ||
            (with_timeout(h->timeout) &&
             nla_put_net32(skb, IPSET_ATTR_TIMEOUT, htonl(h->timeout))))
                goto nla_put_failure;
        ipset_nest_end(skb, nested);

        return 0;
nla_put_failure:
        return -EMSGSIZE;
}

/* Reply a LIST/SAVE request: dump the elements of the specified set */
static int
type_pf_list(const struct ip_set *set,
             struct sk_buff *skb, struct netlink_callback *cb)
{
        const struct ip_set_hash *h = set->data;
        const struct htable *t = h->table;
        struct nlattr *atd, *nested;
        const struct hbucket *n;
        const struct type_pf_elem *data;
        u32 first = cb->args[2];
        /* We assume that one hash bucket fills into one page */
        void *incomplete;
        int i;

        atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
        if (!atd)
                return -EMSGSIZE;
        pr_debug("list hash set %s\n", set->name);
        for (; cb->args[2] < jhash_size(t->htable_bits); cb->args[2]++) {
                incomplete = skb_tail_pointer(skb);
                n = hbucket(t, cb->args[2]);
                pr_debug("cb->args[2]: %lu, t %p n %p\n", cb->args[2], t, n);
                for (i = 0; i < n->pos; i++) {
                        data = ahash_data(n, i);
                        pr_debug("list hash %lu hbucket %p i %u, data %p\n",
                                 cb->args[2], n, i, data);
                        nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
                        if (!nested) {
                                if (cb->args[2] == first) {
                                        nla_nest_cancel(skb, atd);
                                        return -EMSGSIZE;
                                } else
                                        goto nla_put_failure;
                        }
                        if (type_pf_data_list(skb, data))
                                goto nla_put_failure;
                        ipset_nest_end(skb, nested);
                }
        }
        ipset_nest_end(skb, atd);
        /* Set listing finished */
        cb->args[2] = 0;

        return 0;

nla_put_failure:
        nlmsg_trim(skb, incomplete);
        ipset_nest_end(skb, atd);
        if (unlikely(first == cb->args[2])) {
                pr_warning("Can't list set %s: one bucket does not fit into "
                           "a message. Please report it!\n", set->name);
                cb->args[2] = 0;
                return -EMSGSIZE;
        }
        return 0;
}

static int
type_pf_kadt(struct ip_set *set, const struct sk_buff *skb,
             const struct xt_action_param *par,
             enum ipset_adt adt, const struct ip_set_adt_opt *opt);
static int
type_pf_uadt(struct ip_set *set, struct nlattr *tb[],
             enum ipset_adt adt, u32 *lineno, u32 flags, bool retried);

static const struct ip_set_type_variant type_pf_variant = {
        .kadt   = type_pf_kadt,
        .uadt   = type_pf_uadt,
        .adt    = {
                [IPSET_ADD] = type_pf_add,
                [IPSET_DEL] = type_pf_del,
                [IPSET_TEST] = type_pf_test,
        },
        .destroy = type_pf_destroy,
        .flush  = type_pf_flush,
        .head   = type_pf_head,
        .list   = type_pf_list,
        .resize = type_pf_resize,
        .same_set = type_pf_same_set,
};

/* Flavour with timeout support */

#define ahash_tdata(n, i) \
        (struct type_pf_elem *)((struct type_pf_telem *)((n)->value) + (i))

static inline u32
type_pf_data_timeout(const struct type_pf_elem *data)
{
        const struct type_pf_telem *tdata =
                (const struct type_pf_telem *) data;

        return tdata->timeout;
}

static inline bool
type_pf_data_expired(const struct type_pf_elem *data)
{
        const struct type_pf_telem *tdata =
                (const struct type_pf_telem *) data;

        return ip_set_timeout_expired(tdata->timeout);
}

static inline void
type_pf_data_timeout_set(struct type_pf_elem *data, u32 timeout)
{
        struct type_pf_telem *tdata = (struct type_pf_telem *) data;

        tdata->timeout = ip_set_timeout_set(timeout);
}

static int
type_pf_elem_tadd(struct hbucket *n, const struct type_pf_elem *value,
                  u8 ahash_max, u32 cadt_flags, u32 timeout)
{
        struct type_pf_elem *data;

        if (n->pos >= n->size) {
                void *tmp;

                if (n->size >= ahash_max)
                        /* Trigger rehashing */
                        return -EAGAIN;

                tmp = kzalloc((n->size + AHASH_INIT_SIZE)
                              * sizeof(struct type_pf_telem),
                              GFP_ATOMIC);
                if (!tmp)
                        return -ENOMEM;
                if (n->size) {
                        memcpy(tmp, n->value,
                               sizeof(struct type_pf_telem) * n->size);
                        kfree(n->value);
                }
                n->value = tmp;
                n->size += AHASH_INIT_SIZE;
        }
        data = ahash_tdata(n, n->pos++);
        type_pf_data_copy(data, value);
        type_pf_data_timeout_set(data, timeout);
#ifdef IP_SET_HASH_WITH_NETS
        /* Resizing won't overwrite stored flags */
        if (cadt_flags)
                type_pf_data_flags(data, cadt_flags);
#endif
        return 0;
}

/* Delete expired elements from the hashtable */
static void
type_pf_expire(struct ip_set_hash *h, u8 nets_length)
{
        struct htable *t = h->table;
        struct hbucket *n;
        struct type_pf_elem *data;
        u32 i;
        int j;

        for (i = 0; i < jhash_size(t->htable_bits); i++) {
                n = hbucket(t, i);
                for (j = 0; j < n->pos; j++) {
                        data = ahash_tdata(n, j);
                        if (type_pf_data_expired(data)) {
                                pr_debug("expired %u/%u\n", i, j);
#ifdef IP_SET_HASH_WITH_NETS
                                del_cidr(h, CIDR(data->cidr), nets_length);
#endif
                                if (j != n->pos - 1)
                                        /* Not last one */
                                        type_pf_data_copy(data,
                                                ahash_tdata(n, n->pos - 1));
                                n->pos--;
                                h->elements--;
                        }
                }
                if (n->pos + AHASH_INIT_SIZE < n->size) {
                        void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
                                            * sizeof(struct type_pf_telem),
                                            GFP_ATOMIC);
                        if (!tmp)
                                /* Still try to delete expired elements */
                                continue;
                        n->size -= AHASH_INIT_SIZE;
                        memcpy(tmp, n->value,
                               n->size * sizeof(struct type_pf_telem));
                        kfree(n->value);
                        n->value = tmp;
                }
        }
}

static int
type_pf_tresize(struct ip_set *set, bool retried)
{
        struct ip_set_hash *h = set->data;
        struct htable *t, *orig = h->table;
        u8 htable_bits = orig->htable_bits;
        struct type_pf_elem *data;
        struct hbucket *n, *m;
        u32 i, j, flags = 0;
        int ret;

        /* Try to cleanup once */
        if (!retried) {
                i = h->elements;
                write_lock_bh(&set->lock);
                type_pf_expire(set->data, NETS_LENGTH(set->family));
                write_unlock_bh(&set->lock);
                if (h->elements <  i)
                        return 0;
        }

retry:
        ret = 0;
        htable_bits++;
        pr_debug("attempt to resize set %s from %u to %u, t %p\n",
                 set->name, orig->htable_bits, htable_bits, orig);
        if (!htable_bits) {
                /* In case we have plenty of memory :-) */
                pr_warning("Cannot increase the hashsize of set %s further\n",
                           set->name);
                return -IPSET_ERR_HASH_FULL;
        }
        t = ip_set_alloc(sizeof(*t)
                         + jhash_size(htable_bits) * sizeof(struct hbucket));
        if (!t)
                return -ENOMEM;
        t->htable_bits = htable_bits;

        read_lock_bh(&set->lock);
        for (i = 0; i < jhash_size(orig->htable_bits); i++) {
                n = hbucket(orig, i);
                for (j = 0; j < n->pos; j++) {
                        data = ahash_tdata(n, j);
#ifdef IP_SET_HASH_WITH_NETS
                        flags = 0;
                        type_pf_data_reset_flags(data, &flags);
#endif
                        m = hbucket(t, HKEY(data, h->initval, htable_bits));
                        ret = type_pf_elem_tadd(m, data, AHASH_MAX(h), flags,
                                ip_set_timeout_get(type_pf_data_timeout(data)));
                        if (ret < 0) {
#ifdef IP_SET_HASH_WITH_NETS
                                type_pf_data_flags(data, flags);
#endif
                                read_unlock_bh(&set->lock);
                                ahash_destroy(t);
                                if (ret == -EAGAIN)
                                        goto retry;
                                return ret;
                        }
                }
        }

        rcu_assign_pointer(h->table, t);
        read_unlock_bh(&set->lock);

        /* Give time to other readers of the set */
        synchronize_rcu_bh();

        ahash_destroy(orig);

        return 0;
}

static int
type_pf_tadd(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        const struct type_pf_elem *d = value;
        struct hbucket *n;
        struct type_pf_elem *data;
        int ret = 0, i, j = AHASH_MAX(h) + 1;
        bool flag_exist = flags & IPSET_FLAG_EXIST;
        u32 key, multi = 0;
        u32 cadt_flags = flags >> 16;

        if (h->elements >= h->maxelem)
                /* FIXME: when set is full, we slow down here */
                type_pf_expire(h, NETS_LENGTH(set->family));
        if (h->elements >= h->maxelem) {
                if (net_ratelimit())
                        pr_warning("Set %s is full, maxelem %u reached\n",
                                   set->name, h->maxelem);
                return -IPSET_ERR_HASH_FULL;
        }

        rcu_read_lock_bh();
        t = rcu_dereference_bh(h->table);
        key = HKEY(d, h->initval, t->htable_bits);
        n = hbucket(t, key);
        for (i = 0; i < n->pos; i++) {
                data = ahash_tdata(n, i);
                if (type_pf_data_equal(data, d, &multi)) {
                        if (type_pf_data_expired(data) || flag_exist)
                                /* Just timeout value may be updated */
                                j = i;
                        else {
                                ret = -IPSET_ERR_EXIST;
                                goto out;
                        }
                } else if (j == AHASH_MAX(h) + 1 &&
                           type_pf_data_expired(data))
                        j = i;
        }
        if (j != AHASH_MAX(h) + 1) {
                data = ahash_tdata(n, j);
#ifdef IP_SET_HASH_WITH_NETS
                del_cidr(h, CIDR(data->cidr), NETS_LENGTH(set->family));
                add_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
#endif
                type_pf_data_copy(data, d);
                type_pf_data_timeout_set(data, timeout);
#ifdef IP_SET_HASH_WITH_NETS
                type_pf_data_flags(data, cadt_flags);
#endif
                goto out;
        }
        TUNE_AHASH_MAX(h, multi);
        ret = type_pf_elem_tadd(n, d, AHASH_MAX(h), cadt_flags, timeout);
        if (ret != 0) {
                if (ret == -EAGAIN)
                        type_pf_data_next(h, d);
                goto out;
        }

#ifdef IP_SET_HASH_WITH_NETS
        add_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
#endif
        h->elements++;
out:
        rcu_read_unlock_bh();
        return ret;
}

static int
type_pf_tdel(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        const struct type_pf_elem *d = value;
        struct hbucket *n;
        int i;
        struct type_pf_elem *data;
        u32 key, multi = 0;

        key = HKEY(value, h->initval, t->htable_bits);
        n = hbucket(t, key);
        for (i = 0; i < n->pos; i++) {
                data = ahash_tdata(n, i);
                if (!type_pf_data_equal(data, d, &multi))
                        continue;
                if (type_pf_data_expired(data))
                        return -IPSET_ERR_EXIST;
                if (i != n->pos - 1)
                        /* Not last one */
                        type_pf_data_copy(data, ahash_tdata(n, n->pos - 1));

                n->pos--;
                h->elements--;
#ifdef IP_SET_HASH_WITH_NETS
                del_cidr(h, CIDR(d->cidr), NETS_LENGTH(set->family));
#endif
                if (n->pos + AHASH_INIT_SIZE < n->size) {
                        void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
                                            * sizeof(struct type_pf_telem),
                                            GFP_ATOMIC);
                        if (!tmp)
                                return 0;
                        n->size -= AHASH_INIT_SIZE;
                        memcpy(tmp, n->value,
                               n->size * sizeof(struct type_pf_telem));
                        kfree(n->value);
                        n->value = tmp;
                }
                return 0;
        }

        return -IPSET_ERR_EXIST;
}

#ifdef IP_SET_HASH_WITH_NETS
static int
type_pf_ttest_cidrs(struct ip_set *set, struct type_pf_elem *d, u32 timeout)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        struct type_pf_elem *data;
        struct hbucket *n;
        int i, j = 0;
        u32 key, multi = 0;
        u8 nets_length = NETS_LENGTH(set->family);

        for (; j < nets_length && h->nets[j].nets && !multi; j++) {
                type_pf_data_netmask(d, h->nets[j].cidr);
                key = HKEY(d, h->initval, t->htable_bits);
                n = hbucket(t, key);
                for (i = 0; i < n->pos; i++) {
                        data = ahash_tdata(n, i);
#ifdef IP_SET_HASH_WITH_MULTI
                        if (type_pf_data_equal(data, d, &multi)) {
                                if (!type_pf_data_expired(data))
                                        return type_pf_data_match(data);
                                multi = 0;
                        }
#else
                        if (type_pf_data_equal(data, d, &multi) &&
                            !type_pf_data_expired(data))
                                return type_pf_data_match(data);
#endif
                }
        }
        return 0;
}
#endif

static int
type_pf_ttest(struct ip_set *set, void *value, u32 timeout, u32 flags)
{
        struct ip_set_hash *h = set->data;
        struct htable *t = h->table;
        struct type_pf_elem *data, *d = value;
        struct hbucket *n;
        int i;
        u32 key, multi = 0;

#ifdef IP_SET_HASH_WITH_NETS
        if (CIDR(d->cidr) == SET_HOST_MASK(set->family))
                return type_pf_ttest_cidrs(set, d, timeout);
#endif
        key = HKEY(d, h->initval, t->htable_bits);
        n = hbucket(t, key);
        for (i = 0; i < n->pos; i++) {
                data = ahash_tdata(n, i);
                if (type_pf_data_equal(data, d, &multi) &&
                    !type_pf_data_expired(data))
                        return type_pf_data_match(data);
        }
        return 0;
}

static int
type_pf_tlist(const struct ip_set *set,
              struct sk_buff *skb, struct netlink_callback *cb)
{
        const struct ip_set_hash *h = set->data;
        const struct htable *t = h->table;
        struct nlattr *atd, *nested;
        const struct hbucket *n;
        const struct type_pf_elem *data;
        u32 first = cb->args[2];
        /* We assume that one hash bucket fills into one page */
        void *incomplete;
        int i;

        atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
        if (!atd)
                return -EMSGSIZE;
        for (; cb->args[2] < jhash_size(t->htable_bits); cb->args[2]++) {
                incomplete = skb_tail_pointer(skb);
                n = hbucket(t, cb->args[2]);
                for (i = 0; i < n->pos; i++) {
                        data = ahash_tdata(n, i);
                        pr_debug("list %p %u\n", n, i);
                        if (type_pf_data_expired(data))
                                continue;
                        pr_debug("do list %p %u\n", n, i);
                        nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
                        if (!nested) {
                                if (cb->args[2] == first) {
                                        nla_nest_cancel(skb, atd);
                                        return -EMSGSIZE;
                                } else
                                        goto nla_put_failure;
                        }
                        if (type_pf_data_tlist(skb, data))
                                goto nla_put_failure;
                        ipset_nest_end(skb, nested);
                }
        }
        ipset_nest_end(skb, atd);
        /* Set listing finished */
        cb->args[2] = 0;

        return 0;

nla_put_failure:
        nlmsg_trim(skb, incomplete);
        ipset_nest_end(skb, atd);
        if (unlikely(first == cb->args[2])) {
                pr_warning("Can't list set %s: one bucket does not fit into "
                           "a message. Please report it!\n", set->name);
                cb->args[2] = 0;
                return -EMSGSIZE;
        }
        return 0;
}

static const struct ip_set_type_variant type_pf_tvariant = {
        .kadt   = type_pf_kadt,
        .uadt   = type_pf_uadt,
        .adt    = {
                [IPSET_ADD] = type_pf_tadd,
                [IPSET_DEL] = type_pf_tdel,
                [IPSET_TEST] = type_pf_ttest,
        },
        .destroy = type_pf_destroy,
        .flush  = type_pf_flush,
        .head   = type_pf_head,
        .list   = type_pf_tlist,
        .resize = type_pf_tresize,
        .same_set = type_pf_same_set,
};

static void
type_pf_gc(unsigned long ul_set)
{
        struct ip_set *set = (struct ip_set *) ul_set;
        struct ip_set_hash *h = set->data;

        pr_debug("called\n");
        write_lock_bh(&set->lock);
        type_pf_expire(h, NETS_LENGTH(set->family));
        write_unlock_bh(&set->lock);

        h->gc.expires = jiffies + IPSET_GC_PERIOD(h->timeout) * HZ;
        add_timer(&h->gc);
}

static void
type_pf_gc_init(struct ip_set *set)
{
        struct ip_set_hash *h = set->data;

        init_timer(&h->gc);
        h->gc.data = (unsigned long) set;
        h->gc.function = type_pf_gc;
        h->gc.expires = jiffies + IPSET_GC_PERIOD(h->timeout) * HZ;
        add_timer(&h->gc);
        pr_debug("gc initialized, run in every %u\n",
                 IPSET_GC_PERIOD(h->timeout));
}

#undef HKEY_DATALEN
#undef HKEY
#undef type_pf_data_equal
#undef type_pf_data_isnull
#undef type_pf_data_copy
#undef type_pf_data_zero_out
#undef type_pf_data_netmask
#undef type_pf_data_list
#undef type_pf_data_tlist
#undef type_pf_data_next
#undef type_pf_data_flags
#undef type_pf_data_reset_flags
#undef type_pf_data_match

#undef type_pf_elem
#undef type_pf_telem
#undef type_pf_data_timeout
#undef type_pf_data_expired
#undef type_pf_data_timeout_set

#undef type_pf_elem_add
#undef type_pf_add
#undef type_pf_del
#undef type_pf_test_cidrs
#undef type_pf_test

#undef type_pf_elem_tadd
#undef type_pf_del_telem
#undef type_pf_expire
#undef type_pf_tadd
#undef type_pf_tdel
#undef type_pf_ttest_cidrs
#undef type_pf_ttest

#undef type_pf_resize
#undef type_pf_tresize
#undef type_pf_flush
#undef type_pf_destroy
#undef type_pf_head
#undef type_pf_list
#undef type_pf_tlist
#undef type_pf_same_set
#undef type_pf_kadt
#undef type_pf_uadt
#undef type_pf_gc
#undef type_pf_gc_init
#undef type_pf_variant
#undef type_pf_tvariant