include/linux/netfilter/ipset/ip_set_ahash.h

   1 #ifndef _IP_SET_AHASH_H
   2 #define _IP_SET_AHASH_H
   3
   4 #include <linux/rcupdate.h>
   5 #include <linux/jhash.h>
   6 #include <linux/netfilter/ipset/ip_set_timeout.h>
   7
   8 /* Hashing which uses arrays to resolve clashing. The hash table is resized
   9  * (doubled) when searching becomes too long.
  10  * Internally jhash is used with the assumption that the size of the
  11  * stored data is a multiple of sizeof(u32). If storage supports timeout,
  12  * the timeout field must be the last one in the data structure - that field
  13  * is ignored when computing the hash key.
  14  *
  15  * Readers and resizing
  16  *
  17  * Resizing can be triggered by userspace command only, and those
  18  * are serialized by the nfnl mutex. During resizing the set is
  19  * read-locked, so the only possible concurrent operations are
  20  * the kernel side readers. Those must be protected by proper RCU locking.
  21  */
  22
  23 /* Number of elements to store in an initial array block */
  24 #define AHASH_INIT_SIZE                 4
  25 /* Max number of elements to store in an array block */
  26 #define AHASH_MAX_SIZE                  (3*4)
  27
  28 /* A hash bucket */
  29 struct hbucket {
  30         void *value;            /* the array of the values */
  31         u8 size;                /* size of the array */
  32         u8 pos;                 /* position of the first free entry */
  33 };
  34
  35 /* The hash table: the table size stored here in order to make resizing easy */
  36 struct htable {
  37         u8 htable_bits;         /* size of hash table == 2^htable_bits */
  38         struct hbucket bucket[0]; /* hashtable buckets */
  39 };
  40
  41 #define hbucket(h, i)           &((h)->bucket[i])
  42
  43 /* Book-keeping of the prefixes added to the set */
  44 struct ip_set_hash_nets {
  45         u8 cidr;                /* the different cidr values in the set */
  46         u32 nets;               /* number of elements per cidr */
  47 };
  48
  49 /* The generic ip_set hash structure */
  50 struct ip_set_hash {
  51         struct htable *table;   /* the hash table */
  52         u32 maxelem;            /* max elements in the hash */
  53         u32 elements;           /* current element (vs timeout) */
  54         u32 initval;            /* random jhash init value */
  55         u32 timeout;            /* timeout value, if enabled */
  56         struct timer_list gc;   /* garbage collection when timeout enabled */
  57 #ifdef IP_SET_HASH_WITH_NETMASK
  58         u8 netmask;             /* netmask value for subnets to store */
  59 #endif
  60 #ifdef IP_SET_HASH_WITH_NETS
  61         struct ip_set_hash_nets nets[0]; /* book-keeping of prefixes */
  62 #endif
  63 };
  64
  65 /* Compute htable_bits from the user input parameter hashsize */
  66 static u8
  67 htable_bits(u32 hashsize)
  68 {
  69         /* Assume that hashsize == 2^htable_bits */
  70         u8 bits = fls(hashsize - 1);
  71         if (jhash_size(bits) != hashsize)
  72                 /* Round up to the first 2^n value */
  73                 bits = fls(hashsize);
  74
  75         return bits;
  76 }
  77
  78 #ifdef IP_SET_HASH_WITH_NETS
  79
  80 #define SET_HOST_MASK(family)   (family == AF_INET ? 32 : 128)
  81
  82 /* Network cidr size book keeping when the hash stores different
  83  * sized networks */
  84 static void
  85 add_cidr(struct ip_set_hash *h, u8 cidr, u8 host_mask)
  86 {
  87         u8 i;
  88
  89         ++h->nets[cidr-1].nets;
  90
  91         pr_debug("add_cidr added %u: %u\n", cidr, h->nets[cidr-1].nets);
  92
  93         if (h->nets[cidr-1].nets > 1)
  94                 return;
  95
  96         /* New cidr size */
  97         for (i = 0; i < host_mask && h->nets[i].cidr; i++) {
  98                 /* Add in increasing prefix order, so larger cidr first */
  99                 if (h->nets[i].cidr < cidr)
 100                         swap(h->nets[i].cidr, cidr);
 101         }
 102         if (i < host_mask)
 103                 h->nets[i].cidr = cidr;
 104 }
 105
 106 static void
 107 del_cidr(struct ip_set_hash *h, u8 cidr, u8 host_mask)
 108 {
 109         u8 i;
 110
 111         --h->nets[cidr-1].nets;
 112
 113         pr_debug("del_cidr deleted %u: %u\n", cidr, h->nets[cidr-1].nets);
 114
 115         if (h->nets[cidr-1].nets != 0)
 116                 return;
 117
 118         /* All entries with this cidr size deleted, so cleanup h->cidr[] */
 119         for (i = 0; i < host_mask - 1 && h->nets[i].cidr; i++) {
 120                 if (h->nets[i].cidr == cidr)
 121                         h->nets[i].cidr = cidr = h->nets[i+1].cidr;
 122         }
 123         h->nets[i - 1].cidr = 0;
 124 }
 125 #endif
 126
 127 /* Destroy the hashtable part of the set */
 128 static void
 129 ahash_destroy(struct htable *t)
 130 {
 131         struct hbucket *n;
 132         u32 i;
 133
 134         for (i = 0; i < jhash_size(t->htable_bits); i++) {
 135                 n = hbucket(t, i);
 136                 if (n->size)
 137                         /* FIXME: use slab cache */
 138                         kfree(n->value);
 139         }
 140
 141         ip_set_free(t);
 142 }
 143
 144 /* Calculate the actual memory size of the set data */
 145 static size_t
 146 ahash_memsize(const struct ip_set_hash *h, size_t dsize, u8 host_mask)
 147 {
 148         u32 i;
 149         struct htable *t = h->table;
 150         size_t memsize = sizeof(*h)
 151                          + sizeof(*t)
 152 #ifdef IP_SET_HASH_WITH_NETS
 153                          + sizeof(struct ip_set_hash_nets) * host_mask
 154 #endif
 155                          + jhash_size(t->htable_bits) * sizeof(struct hbucket);
 156
 157         for (i = 0; i < jhash_size(t->htable_bits); i++)
 158                         memsize += t->bucket[i].size * dsize;
 159
 160         return memsize;
 161 }
 162
 163 /* Flush a hash type of set: destroy all elements */
 164 static void
 165 ip_set_hash_flush(struct ip_set *set)
 166 {
 167         struct ip_set_hash *h = set->data;
 168         struct htable *t = h->table;
 169         struct hbucket *n;
 170         u32 i;
 171
 172         for (i = 0; i < jhash_size(t->htable_bits); i++) {
 173                 n = hbucket(t, i);
 174                 if (n->size) {
 175                         n->size = n->pos = 0;
 176                         /* FIXME: use slab cache */
 177                         kfree(n->value);
 178                 }
 179         }
 180 #ifdef IP_SET_HASH_WITH_NETS
 181         memset(h->nets, 0, sizeof(struct ip_set_hash_nets)
 182                            * SET_HOST_MASK(set->family));
 183 #endif
 184         h->elements = 0;
 185 }
 186
 187 /* Destroy a hash type of set */
 188 static void
 189 ip_set_hash_destroy(struct ip_set *set)
 190 {
 191         struct ip_set_hash *h = set->data;
 192
 193         if (with_timeout(h->timeout))
 194                 del_timer_sync(&h->gc);
 195
 196         ahash_destroy(h->table);
 197         kfree(h);
 198
 199         set->data = NULL;
 200 }
 201
 202 #define HKEY(data, initval, htable_bits)                                 \
 203 (jhash2((u32 *)(data), sizeof(struct type_pf_elem)/sizeof(u32), initval) \
 204         & jhash_mask(htable_bits))
 205
 206 #endif /* _IP_SET_AHASH_H */
 207
 208 #define CONCAT(a, b, c)         a##b##c
 209 #define TOKEN(a, b, c)          CONCAT(a, b, c)
 210
 211 /* Type/family dependent function prototypes */
 212
 213 #define type_pf_data_equal      TOKEN(TYPE, PF, _data_equal)
 214 #define type_pf_data_isnull     TOKEN(TYPE, PF, _data_isnull)
 215 #define type_pf_data_copy       TOKEN(TYPE, PF, _data_copy)
 216 #define type_pf_data_zero_out   TOKEN(TYPE, PF, _data_zero_out)
 217 #define type_pf_data_netmask    TOKEN(TYPE, PF, _data_netmask)
 218 #define type_pf_data_list       TOKEN(TYPE, PF, _data_list)
 219 #define type_pf_data_tlist      TOKEN(TYPE, PF, _data_tlist)
 220
 221 #define type_pf_elem            TOKEN(TYPE, PF, _elem)
 222 #define type_pf_telem           TOKEN(TYPE, PF, _telem)
 223 #define type_pf_data_timeout    TOKEN(TYPE, PF, _data_timeout)
 224 #define type_pf_data_expired    TOKEN(TYPE, PF, _data_expired)
 225 #define type_pf_data_timeout_set TOKEN(TYPE, PF, _data_timeout_set)
 226
 227 #define type_pf_elem_add        TOKEN(TYPE, PF, _elem_add)
 228 #define type_pf_add             TOKEN(TYPE, PF, _add)
 229 #define type_pf_del             TOKEN(TYPE, PF, _del)
 230 #define type_pf_test_cidrs      TOKEN(TYPE, PF, _test_cidrs)
 231 #define type_pf_test            TOKEN(TYPE, PF, _test)
 232
 233 #define type_pf_elem_tadd       TOKEN(TYPE, PF, _elem_tadd)
 234 #define type_pf_del_telem       TOKEN(TYPE, PF, _ahash_del_telem)
 235 #define type_pf_expire          TOKEN(TYPE, PF, _expire)
 236 #define type_pf_tadd            TOKEN(TYPE, PF, _tadd)
 237 #define type_pf_tdel            TOKEN(TYPE, PF, _tdel)
 238 #define type_pf_ttest_cidrs     TOKEN(TYPE, PF, _ahash_ttest_cidrs)
 239 #define type_pf_ttest           TOKEN(TYPE, PF, _ahash_ttest)
 240
 241 #define type_pf_resize          TOKEN(TYPE, PF, _resize)
 242 #define type_pf_tresize         TOKEN(TYPE, PF, _tresize)
 243 #define type_pf_flush           ip_set_hash_flush
 244 #define type_pf_destroy         ip_set_hash_destroy
 245 #define type_pf_head            TOKEN(TYPE, PF, _head)
 246 #define type_pf_list            TOKEN(TYPE, PF, _list)
 247 #define type_pf_tlist           TOKEN(TYPE, PF, _tlist)
 248 #define type_pf_same_set        TOKEN(TYPE, PF, _same_set)
 249 #define type_pf_kadt            TOKEN(TYPE, PF, _kadt)
 250 #define type_pf_uadt            TOKEN(TYPE, PF, _uadt)
 251 #define type_pf_gc              TOKEN(TYPE, PF, _gc)
 252 #define type_pf_gc_init         TOKEN(TYPE, PF, _gc_init)
 253 #define type_pf_variant         TOKEN(TYPE, PF, _variant)
 254 #define type_pf_tvariant        TOKEN(TYPE, PF, _tvariant)
 255
 256 /* Flavour without timeout */
 257
 258 /* Get the ith element from the array block n */
 259 #define ahash_data(n, i)        \
 260         ((struct type_pf_elem *)((n)->value) + (i))
 261
 262 /* Add an element to the hash table when resizing the set:
 263  * we spare the maintenance of the internal counters. */
 264 static int
 265 type_pf_elem_add(struct hbucket *n, const struct type_pf_elem *value)
 266 {
 267         if (n->pos >= n->size) {
 268                 void *tmp;
 269
 270                 if (n->size >= AHASH_MAX_SIZE)
 271                         /* Trigger rehashing */
 272                         return -EAGAIN;
 273
 274                 tmp = kzalloc((n->size + AHASH_INIT_SIZE)
 275                               * sizeof(struct type_pf_elem),
 276                               GFP_ATOMIC);
 277                 if (!tmp)
 278                         return -ENOMEM;
 279                 if (n->size) {
 280                         memcpy(tmp, n->value,
 281                                sizeof(struct type_pf_elem) * n->size);
 282                         kfree(n->value);
 283                 }
 284                 n->value = tmp;
 285                 n->size += AHASH_INIT_SIZE;
 286         }
 287         type_pf_data_copy(ahash_data(n, n->pos++), value);
 288         return 0;
 289 }
 290
 291 /* Resize a hash: create a new hash table with doubling the hashsize
 292  * and inserting the elements to it. Repeat until we succeed or
 293  * fail due to memory pressures. */
 294 static int
 295 type_pf_resize(struct ip_set *set, bool retried)
 296 {
 297         struct ip_set_hash *h = set->data;
 298         struct htable *t, *orig = h->table;
 299         u8 htable_bits = orig->htable_bits;
 300         const struct type_pf_elem *data;
 301         struct hbucket *n, *m;
 302         u32 i, j;
 303         int ret;
 304
 305 retry:
 306         ret = 0;
 307         htable_bits++;
 308         pr_debug("attempt to resize set %s from %u to %u, t %p\n",
 309                  set->name, orig->htable_bits, htable_bits, orig);
 310         if (!htable_bits)
 311                 /* In case we have plenty of memory :-) */
 312                 return -IPSET_ERR_HASH_FULL;
 313         t = ip_set_alloc(sizeof(*t)
 314                          + jhash_size(htable_bits) * sizeof(struct hbucket));
 315         if (!t)
 316                 return -ENOMEM;
 317         t->htable_bits = htable_bits;
 318
 319         read_lock_bh(&set->lock);
 320         for (i = 0; i < jhash_size(orig->htable_bits); i++) {
 321                 n = hbucket(orig, i);
 322                 for (j = 0; j < n->pos; j++) {
 323                         data = ahash_data(n, j);
 324                         m = hbucket(t, HKEY(data, h->initval, htable_bits));
 325                         ret = type_pf_elem_add(m, data);
 326                         if (ret < 0) {
 327                                 read_unlock_bh(&set->lock);
 328                                 ahash_destroy(t);
 329                                 if (ret == -EAGAIN)
 330                                         goto retry;
 331                                 return ret;
 332                         }
 333                 }
 334         }
 335
 336         rcu_assign_pointer(h->table, t);
 337         read_unlock_bh(&set->lock);
 338
 339         /* Give time to other readers of the set */
 340         synchronize_rcu_bh();
 341
 342         pr_debug("set %s resized from %u (%p) to %u (%p)\n", set->name,
 343                  orig->htable_bits, orig, t->htable_bits, t);
 344         ahash_destroy(orig);
 345
 346         return 0;
 347 }
 348
 349 /* Add an element to a hash and update the internal counters when succeeded,
 350  * otherwise report the proper error code. */
 351 static int
 352 type_pf_add(struct ip_set *set, void *value, u32 timeout)
 353 {
 354         struct ip_set_hash *h = set->data;
 355         struct htable *t;
 356         const struct type_pf_elem *d = value;
 357         struct hbucket *n;
 358         int i, ret = 0;
 359         u32 key;
 360
 361         if (h->elements >= h->maxelem)
 362                 return -IPSET_ERR_HASH_FULL;
 363
 364         rcu_read_lock_bh();
 365         t = rcu_dereference_bh(h->table);
 366         key = HKEY(value, h->initval, t->htable_bits);
 367         n = hbucket(t, key);
 368         for (i = 0; i < n->pos; i++)
 369                 if (type_pf_data_equal(ahash_data(n, i), d)) {
 370                         ret = -IPSET_ERR_EXIST;
 371                         goto out;
 372                 }
 373
 374         ret = type_pf_elem_add(n, value);
 375         if (ret != 0)
 376                 goto out;
 377
 378 #ifdef IP_SET_HASH_WITH_NETS
 379         add_cidr(h, d->cidr, HOST_MASK);
 380 #endif
 381         h->elements++;
 382 out:
 383         rcu_read_unlock_bh();
 384         return ret;
 385 }
 386
 387 /* Delete an element from the hash: swap it with the last element
 388  * and free up space if possible.
 389  */
 390 static int
 391 type_pf_del(struct ip_set *set, void *value, u32 timeout)
 392 {
 393         struct ip_set_hash *h = set->data;
 394         struct htable *t = h->table;
 395         const struct type_pf_elem *d = value;
 396         struct hbucket *n;
 397         int i;
 398         struct type_pf_elem *data;
 399         u32 key;
 400
 401         key = HKEY(value, h->initval, t->htable_bits);
 402         n = hbucket(t, key);
 403         for (i = 0; i < n->pos; i++) {
 404                 data = ahash_data(n, i);
 405                 if (!type_pf_data_equal(data, d))
 406                         continue;
 407                 if (i != n->pos - 1)
 408                         /* Not last one */
 409                         type_pf_data_copy(data, ahash_data(n, n->pos - 1));
 410
 411                 n->pos--;
 412                 h->elements--;
 413 #ifdef IP_SET_HASH_WITH_NETS
 414                 del_cidr(h, d->cidr, HOST_MASK);
 415 #endif
 416                 if (n->pos + AHASH_INIT_SIZE < n->size) {
 417                         void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
 418                                             * sizeof(struct type_pf_elem),
 419                                             GFP_ATOMIC);
 420                         if (!tmp)
 421                                 return 0;
 422                         n->size -= AHASH_INIT_SIZE;
 423                         memcpy(tmp, n->value,
 424                                n->size * sizeof(struct type_pf_elem));
 425                         kfree(n->value);
 426                         n->value = tmp;
 427                 }
 428                 return 0;
 429         }
 430
 431         return -IPSET_ERR_EXIST;
 432 }
 433
 434 #ifdef IP_SET_HASH_WITH_NETS
 435
 436 /* Special test function which takes into account the different network
 437  * sizes added to the set */
 438 static int
 439 type_pf_test_cidrs(struct ip_set *set, struct type_pf_elem *d, u32 timeout)
 440 {
 441         struct ip_set_hash *h = set->data;
 442         struct htable *t = h->table;
 443         struct hbucket *n;
 444         const struct type_pf_elem *data;
 445         int i, j = 0;
 446         u32 key;
 447         u8 host_mask = SET_HOST_MASK(set->family);
 448
 449         pr_debug("test by nets\n");
 450         for (; j < host_mask && h->nets[j].cidr; j++) {
 451                 type_pf_data_netmask(d, h->nets[j].cidr);
 452                 key = HKEY(d, h->initval, t->htable_bits);
 453                 n = hbucket(t, key);
 454                 for (i = 0; i < n->pos; i++) {
 455                         data = ahash_data(n, i);
 456                         if (type_pf_data_equal(data, d))
 457                                 return 1;
 458                 }
 459         }
 460         return 0;
 461 }
 462 #endif
 463
 464 /* Test whether the element is added to the set */
 465 static int
 466 type_pf_test(struct ip_set *set, void *value, u32 timeout)
 467 {
 468         struct ip_set_hash *h = set->data;
 469         struct htable *t = h->table;
 470         struct type_pf_elem *d = value;
 471         struct hbucket *n;
 472         const struct type_pf_elem *data;
 473         int i;
 474         u32 key;
 475
 476 #ifdef IP_SET_HASH_WITH_NETS
 477         /* If we test an IP address and not a network address,
 478          * try all possible network sizes */
 479         if (d->cidr == SET_HOST_MASK(set->family))
 480                 return type_pf_test_cidrs(set, d, timeout);
 481 #endif
 482
 483         key = HKEY(d, h->initval, t->htable_bits);
 484         n = hbucket(t, key);
 485         for (i = 0; i < n->pos; i++) {
 486                 data = ahash_data(n, i);
 487                 if (type_pf_data_equal(data, d))
 488                         return 1;
 489         }
 490         return 0;
 491 }
 492
 493 /* Reply a HEADER request: fill out the header part of the set */
 494 static int
 495 type_pf_head(struct ip_set *set, struct sk_buff *skb)
 496 {
 497         const struct ip_set_hash *h = set->data;
 498         struct nlattr *nested;
 499         size_t memsize;
 500
 501         read_lock_bh(&set->lock);
 502         memsize = ahash_memsize(h, with_timeout(h->timeout)
 503                                         ? sizeof(struct type_pf_telem)
 504                                         : sizeof(struct type_pf_elem),
 505                                 set->family == AF_INET ? 32 : 128);
 506         read_unlock_bh(&set->lock);
 507
 508         nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
 509         if (!nested)
 510                 goto nla_put_failure;
 511         NLA_PUT_NET32(skb, IPSET_ATTR_HASHSIZE,
 512                       htonl(jhash_size(h->table->htable_bits)));
 513         NLA_PUT_NET32(skb, IPSET_ATTR_MAXELEM, htonl(h->maxelem));
 514 #ifdef IP_SET_HASH_WITH_NETMASK
 515         if (h->netmask != HOST_MASK)
 516                 NLA_PUT_U8(skb, IPSET_ATTR_NETMASK, h->netmask);
 517 #endif
 518         NLA_PUT_NET32(skb, IPSET_ATTR_REFERENCES, htonl(set->ref - 1));
 519         NLA_PUT_NET32(skb, IPSET_ATTR_MEMSIZE, htonl(memsize));
 520         if (with_timeout(h->timeout))
 521                 NLA_PUT_NET32(skb, IPSET_ATTR_TIMEOUT, htonl(h->timeout));
 522         ipset_nest_end(skb, nested);
 523
 524         return 0;
 525 nla_put_failure:
 526         return -EMSGSIZE;
 527 }
 528
 529 /* Reply a LIST/SAVE request: dump the elements of the specified set */
 530 static int
 531 type_pf_list(const struct ip_set *set,
 532              struct sk_buff *skb, struct netlink_callback *cb)
 533 {
 534         const struct ip_set_hash *h = set->data;
 535         const struct htable *t = h->table;
 536         struct nlattr *atd, *nested;
 537         const struct hbucket *n;
 538         const struct type_pf_elem *data;
 539         u32 first = cb->args[2];
 540         /* We assume that one hash bucket fills into one page */
 541         void *incomplete;
 542         int i;
 543
 544         atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
 545         if (!atd)
 546                 return -EMSGSIZE;
 547         pr_debug("list hash set %s\n", set->name);
 548         for (; cb->args[2] < jhash_size(t->htable_bits); cb->args[2]++) {
 549                 incomplete = skb_tail_pointer(skb);
 550                 n = hbucket(t, cb->args[2]);
 551                 pr_debug("cb->args[2]: %lu, t %p n %p\n", cb->args[2], t, n);
 552                 for (i = 0; i < n->pos; i++) {
 553                         data = ahash_data(n, i);
 554                         pr_debug("list hash %lu hbucket %p i %u, data %p\n",
 555                                  cb->args[2], n, i, data);
 556                         nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
 557                         if (!nested) {
 558                                 if (cb->args[2] == first) {
 559                                         nla_nest_cancel(skb, atd);
 560                                         return -EMSGSIZE;
 561                                 } else
 562                                         goto nla_put_failure;
 563                         }
 564                         if (type_pf_data_list(skb, data))
 565                                 goto nla_put_failure;
 566                         ipset_nest_end(skb, nested);
 567                 }
 568         }
 569         ipset_nest_end(skb, atd);
 570         /* Set listing finished */
 571         cb->args[2] = 0;
 572
 573         return 0;
 574
 575 nla_put_failure:
 576         nlmsg_trim(skb, incomplete);
 577         ipset_nest_end(skb, atd);
 578         if (unlikely(first == cb->args[2])) {
 579                 pr_warning("Can't list set %s: one bucket does not fit into "
 580                            "a message. Please report it!\n", set->name);
 581                 cb->args[2] = 0;
 582                 return -EMSGSIZE;
 583         }
 584         return 0;
 585 }
 586
 587 static int
 588 type_pf_kadt(struct ip_set *set, const struct sk_buff * skb,
 589              enum ipset_adt adt, u8 pf, u8 dim, u8 flags);
 590 static int
 591 type_pf_uadt(struct ip_set *set, struct nlattr *tb[],
 592              enum ipset_adt adt, u32 *lineno, u32 flags);
 593
 594 static const struct ip_set_type_variant type_pf_variant = {
 595         .kadt   = type_pf_kadt,
 596         .uadt   = type_pf_uadt,
 597         .adt    = {
 598                 [IPSET_ADD] = type_pf_add,
 599                 [IPSET_DEL] = type_pf_del,
 600                 [IPSET_TEST] = type_pf_test,
 601         },
 602         .destroy = type_pf_destroy,
 603         .flush  = type_pf_flush,
 604         .head   = type_pf_head,
 605         .list   = type_pf_list,
 606         .resize = type_pf_resize,
 607         .same_set = type_pf_same_set,
 608 };
 609
 610 /* Flavour with timeout support */
 611
 612 #define ahash_tdata(n, i) \
 613         (struct type_pf_elem *)((struct type_pf_telem *)((n)->value) + (i))
 614
 615 static inline u32
 616 type_pf_data_timeout(const struct type_pf_elem *data)
 617 {
 618         const struct type_pf_telem *tdata =
 619                 (const struct type_pf_telem *) data;
 620
 621         return tdata->timeout;
 622 }
 623
 624 static inline bool
 625 type_pf_data_expired(const struct type_pf_elem *data)
 626 {
 627         const struct type_pf_telem *tdata =
 628                 (const struct type_pf_telem *) data;
 629
 630         return ip_set_timeout_expired(tdata->timeout);
 631 }
 632
 633 static inline void
 634 type_pf_data_timeout_set(struct type_pf_elem *data, u32 timeout)
 635 {
 636         struct type_pf_telem *tdata = (struct type_pf_telem *) data;
 637
 638         tdata->timeout = ip_set_timeout_set(timeout);
 639 }
 640
 641 static int
 642 type_pf_elem_tadd(struct hbucket *n, const struct type_pf_elem *value,
 643                   u32 timeout)
 644 {
 645         struct type_pf_elem *data;
 646
 647         if (n->pos >= n->size) {
 648                 void *tmp;
 649
 650                 if (n->size >= AHASH_MAX_SIZE)
 651                         /* Trigger rehashing */
 652                         return -EAGAIN;
 653
 654                 tmp = kzalloc((n->size + AHASH_INIT_SIZE)
 655                               * sizeof(struct type_pf_telem),
 656                               GFP_ATOMIC);
 657                 if (!tmp)
 658                         return -ENOMEM;
 659                 if (n->size) {
 660                         memcpy(tmp, n->value,
 661                                sizeof(struct type_pf_telem) * n->size);
 662                         kfree(n->value);
 663                 }
 664                 n->value = tmp;
 665                 n->size += AHASH_INIT_SIZE;
 666         }
 667         data = ahash_tdata(n, n->pos++);
 668         type_pf_data_copy(data, value);
 669         type_pf_data_timeout_set(data, timeout);
 670         return 0;
 671 }
 672
 673 /* Delete expired elements from the hashtable */
 674 static void
 675 type_pf_expire(struct ip_set_hash *h)
 676 {
 677         struct htable *t = h->table;
 678         struct hbucket *n;
 679         struct type_pf_elem *data;
 680         u32 i;
 681         int j;
 682
 683         for (i = 0; i < jhash_size(t->htable_bits); i++) {
 684                 n = hbucket(t, i);
 685                 for (j = 0; j < n->pos; j++) {
 686                         data = ahash_tdata(n, j);
 687                         if (type_pf_data_expired(data)) {
 688                                 pr_debug("expired %u/%u\n", i, j);
 689 #ifdef IP_SET_HASH_WITH_NETS
 690                                 del_cidr(h, data->cidr, HOST_MASK);
 691 #endif
 692                                 if (j != n->pos - 1)
 693                                         /* Not last one */
 694                                         type_pf_data_copy(data,
 695                                                 ahash_tdata(n, n->pos - 1));
 696                                 n->pos--;
 697                                 h->elements--;
 698                         }
 699                 }
 700                 if (n->pos + AHASH_INIT_SIZE < n->size) {
 701                         void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
 702                                             * sizeof(struct type_pf_telem),
 703                                             GFP_ATOMIC);
 704                         if (!tmp)
 705                                 /* Still try to delete expired elements */
 706                                 continue;
 707                         n->size -= AHASH_INIT_SIZE;
 708                         memcpy(tmp, n->value,
 709                                n->size * sizeof(struct type_pf_telem));
 710                         kfree(n->value);
 711                         n->value = tmp;
 712                 }
 713         }
 714 }
 715
 716 static int
 717 type_pf_tresize(struct ip_set *set, bool retried)
 718 {
 719         struct ip_set_hash *h = set->data;
 720         struct htable *t, *orig = h->table;
 721         u8 htable_bits = orig->htable_bits;
 722         const struct type_pf_elem *data;
 723         struct hbucket *n, *m;
 724         u32 i, j;
 725         int ret;
 726
 727         /* Try to cleanup once */
 728         if (!retried) {
 729                 i = h->elements;
 730                 write_lock_bh(&set->lock);
 731                 type_pf_expire(set->data);
 732                 write_unlock_bh(&set->lock);
 733                 if (h->elements <  i)
 734                         return 0;
 735         }
 736
 737 retry:
 738         ret = 0;
 739         htable_bits++;
 740         if (!htable_bits)
 741                 /* In case we have plenty of memory :-) */
 742                 return -IPSET_ERR_HASH_FULL;
 743         t = ip_set_alloc(sizeof(*t)
 744                          + jhash_size(htable_bits) * sizeof(struct hbucket));
 745         if (!t)
 746                 return -ENOMEM;
 747         t->htable_bits = htable_bits;
 748
 749         read_lock_bh(&set->lock);
 750         for (i = 0; i < jhash_size(orig->htable_bits); i++) {
 751                 n = hbucket(orig, i);
 752                 for (j = 0; j < n->pos; j++) {
 753                         data = ahash_tdata(n, j);
 754                         m = hbucket(t, HKEY(data, h->initval, htable_bits));
 755                         ret = type_pf_elem_tadd(m, data,
 756                                                 type_pf_data_timeout(data));
 757                         if (ret < 0) {
 758                                 read_unlock_bh(&set->lock);
 759                                 ahash_destroy(t);
 760                                 if (ret == -EAGAIN)
 761                                         goto retry;
 762                                 return ret;
 763                         }
 764                 }
 765         }
 766
 767         rcu_assign_pointer(h->table, t);
 768         read_unlock_bh(&set->lock);
 769
 770         /* Give time to other readers of the set */
 771         synchronize_rcu_bh();
 772
 773         ahash_destroy(orig);
 774
 775         return 0;
 776 }
 777
 778 static int
 779 type_pf_tadd(struct ip_set *set, void *value, u32 timeout)
 780 {
 781         struct ip_set_hash *h = set->data;
 782         struct htable *t = h->table;
 783         const struct type_pf_elem *d = value;
 784         struct hbucket *n;
 785         struct type_pf_elem *data;
 786         int ret = 0, i, j = AHASH_MAX_SIZE + 1;
 787         u32 key;
 788
 789         if (h->elements >= h->maxelem)
 790                 /* FIXME: when set is full, we slow down here */
 791                 type_pf_expire(h);
 792         if (h->elements >= h->maxelem)
 793                 return -IPSET_ERR_HASH_FULL;
 794
 795         rcu_read_lock_bh();
 796         t = rcu_dereference_bh(h->table);
 797         key = HKEY(d, h->initval, t->htable_bits);
 798         n = hbucket(t, key);
 799         for (i = 0; i < n->pos; i++) {
 800                 data = ahash_tdata(n, i);
 801                 if (type_pf_data_equal(data, d)) {
 802                         if (type_pf_data_expired(data))
 803                                 j = i;
 804                         else {
 805                                 ret = -IPSET_ERR_EXIST;
 806                                 goto out;
 807                         }
 808                 } else if (j == AHASH_MAX_SIZE + 1 &&
 809                            type_pf_data_expired(data))
 810                         j = i;
 811         }
 812         if (j != AHASH_MAX_SIZE + 1) {
 813                 data = ahash_tdata(n, j);
 814 #ifdef IP_SET_HASH_WITH_NETS
 815                 del_cidr(h, data->cidr, HOST_MASK);
 816                 add_cidr(h, d->cidr, HOST_MASK);
 817 #endif
 818                 type_pf_data_copy(data, d);
 819                 type_pf_data_timeout_set(data, timeout);
 820                 goto out;
 821         }
 822         ret = type_pf_elem_tadd(n, d, timeout);
 823         if (ret != 0)
 824                 goto out;
 825
 826 #ifdef IP_SET_HASH_WITH_NETS
 827         add_cidr(h, d->cidr, HOST_MASK);
 828 #endif
 829         h->elements++;
 830 out:
 831         rcu_read_unlock_bh();
 832         return ret;
 833 }
 834
 835 static int
 836 type_pf_tdel(struct ip_set *set, void *value, u32 timeout)
 837 {
 838         struct ip_set_hash *h = set->data;
 839         struct htable *t = h->table;
 840         const struct type_pf_elem *d = value;
 841         struct hbucket *n;
 842         int i, ret = 0;
 843         struct type_pf_elem *data;
 844         u32 key;
 845
 846         key = HKEY(value, h->initval, t->htable_bits);
 847         n = hbucket(t, key);
 848         for (i = 0; i < n->pos; i++) {
 849                 data = ahash_tdata(n, i);
 850                 if (!type_pf_data_equal(data, d))
 851                         continue;
 852                 if (type_pf_data_expired(data))
 853                         ret = -IPSET_ERR_EXIST;
 854                 if (i != n->pos - 1)
 855                         /* Not last one */
 856                         type_pf_data_copy(data, ahash_tdata(n, n->pos - 1));
 857
 858                 n->pos--;
 859                 h->elements--;
 860 #ifdef IP_SET_HASH_WITH_NETS
 861                 del_cidr(h, d->cidr, HOST_MASK);
 862 #endif
 863                 if (n->pos + AHASH_INIT_SIZE < n->size) {
 864                         void *tmp = kzalloc((n->size - AHASH_INIT_SIZE)
 865                                             * sizeof(struct type_pf_telem),
 866                                             GFP_ATOMIC);
 867                         if (!tmp)
 868                                 return 0;
 869                         n->size -= AHASH_INIT_SIZE;
 870                         memcpy(tmp, n->value,
 871                                n->size * sizeof(struct type_pf_telem));
 872                         kfree(n->value);
 873                         n->value = tmp;
 874                 }
 875                 return 0;
 876         }
 877
 878         return -IPSET_ERR_EXIST;
 879 }
 880
 881 #ifdef IP_SET_HASH_WITH_NETS
 882 static int
 883 type_pf_ttest_cidrs(struct ip_set *set, struct type_pf_elem *d, u32 timeout)
 884 {
 885         struct ip_set_hash *h = set->data;
 886         struct htable *t = h->table;
 887         struct type_pf_elem *data;
 888         struct hbucket *n;
 889         int i, j = 0;
 890         u32 key;
 891         u8 host_mask = SET_HOST_MASK(set->family);
 892
 893         for (; j < host_mask && h->nets[j].cidr; j++) {
 894                 type_pf_data_netmask(d, h->nets[j].cidr);
 895                 key = HKEY(d, h->initval, t->htable_bits);
 896                 n = hbucket(t, key);
 897                 for (i = 0; i < n->pos; i++) {
 898                         data = ahash_tdata(n, i);
 899                         if (type_pf_data_equal(data, d))
 900                                 return !type_pf_data_expired(data);
 901                 }
 902         }
 903         return 0;
 904 }
 905 #endif
 906
 907 static int
 908 type_pf_ttest(struct ip_set *set, void *value, u32 timeout)
 909 {
 910         struct ip_set_hash *h = set->data;
 911         struct htable *t = h->table;
 912         struct type_pf_elem *data, *d = value;
 913         struct hbucket *n;
 914         int i;
 915         u32 key;
 916
 917 #ifdef IP_SET_HASH_WITH_NETS
 918         if (d->cidr == SET_HOST_MASK(set->family))
 919                 return type_pf_ttest_cidrs(set, d, timeout);
 920 #endif
 921         key = HKEY(d, h->initval, t->htable_bits);
 922         n = hbucket(t, key);
 923         for (i = 0; i < n->pos; i++) {
 924                 data = ahash_tdata(n, i);
 925                 if (type_pf_data_equal(data, d))
 926                         return !type_pf_data_expired(data);
 927         }
 928         return 0;
 929 }
 930
 931 static int
 932 type_pf_tlist(const struct ip_set *set,
 933               struct sk_buff *skb, struct netlink_callback *cb)
 934 {
 935         const struct ip_set_hash *h = set->data;
 936         const struct htable *t = h->table;
 937         struct nlattr *atd, *nested;
 938         const struct hbucket *n;
 939         const struct type_pf_elem *data;
 940         u32 first = cb->args[2];
 941         /* We assume that one hash bucket fills into one page */
 942         void *incomplete;
 943         int i;
 944
 945         atd = ipset_nest_start(skb, IPSET_ATTR_ADT);
 946         if (!atd)
 947                 return -EMSGSIZE;
 948         for (; cb->args[2] < jhash_size(t->htable_bits); cb->args[2]++) {
 949                 incomplete = skb_tail_pointer(skb);
 950                 n = hbucket(t, cb->args[2]);
 951                 for (i = 0; i < n->pos; i++) {
 952                         data = ahash_tdata(n, i);
 953                         pr_debug("list %p %u\n", n, i);
 954                         if (type_pf_data_expired(data))
 955                                 continue;
 956                         pr_debug("do list %p %u\n", n, i);
 957                         nested = ipset_nest_start(skb, IPSET_ATTR_DATA);
 958                         if (!nested) {
 959                                 if (cb->args[2] == first) {
 960                                         nla_nest_cancel(skb, atd);
 961                                         return -EMSGSIZE;
 962                                 } else
 963                                         goto nla_put_failure;
 964                         }
 965                         if (type_pf_data_tlist(skb, data))
 966                                 goto nla_put_failure;
 967                         ipset_nest_end(skb, nested);
 968                 }
 969         }
 970         ipset_nest_end(skb, atd);
 971         /* Set listing finished */
 972         cb->args[2] = 0;
 973
 974         return 0;
 975
 976 nla_put_failure:
 977         nlmsg_trim(skb, incomplete);
 978         ipset_nest_end(skb, atd);
 979         if (unlikely(first == cb->args[2])) {
 980                 pr_warning("Can't list set %s: one bucket does not fit into "
 981                            "a message. Please report it!\n", set->name);
 982                 cb->args[2] = 0;
 983                 return -EMSGSIZE;
 984         }
 985         return 0;
 986 }
 987
 988 static const struct ip_set_type_variant type_pf_tvariant = {
 989         .kadt   = type_pf_kadt,
 990         .uadt   = type_pf_uadt,
 991         .adt    = {
 992                 [IPSET_ADD] = type_pf_tadd,
 993                 [IPSET_DEL] = type_pf_tdel,
 994                 [IPSET_TEST] = type_pf_ttest,
 995         },
 996         .destroy = type_pf_destroy,
 997         .flush  = type_pf_flush,
 998         .head   = type_pf_head,
 999         .list   = type_pf_tlist,
1000         .resize = type_pf_tresize,
1001         .same_set = type_pf_same_set,
1002 };
1003
1004 static void
1005 type_pf_gc(unsigned long ul_set)
1006 {
1007         struct ip_set *set = (struct ip_set *) ul_set;
1008         struct ip_set_hash *h = set->data;
1009
1010         pr_debug("called\n");
1011         write_lock_bh(&set->lock);
1012         type_pf_expire(h);
1013         write_unlock_bh(&set->lock);
1014
1015         h->gc.expires = jiffies + IPSET_GC_PERIOD(h->timeout) * HZ;
1016         add_timer(&h->gc);
1017 }
1018
1019 static void
1020 type_pf_gc_init(struct ip_set *set)
1021 {
1022         struct ip_set_hash *h = set->data;
1023
1024         init_timer(&h->gc);
1025         h->gc.data = (unsigned long) set;
1026         h->gc.function = type_pf_gc;
1027         h->gc.expires = jiffies + IPSET_GC_PERIOD(h->timeout) * HZ;
1028         add_timer(&h->gc);
1029         pr_debug("gc initialized, run in every %u\n",
1030                  IPSET_GC_PERIOD(h->timeout));
1031 }
1032
1033 #undef type_pf_data_equal
1034 #undef type_pf_data_isnull
1035 #undef type_pf_data_copy
1036 #undef type_pf_data_zero_out
1037 #undef type_pf_data_list
1038 #undef type_pf_data_tlist
1039
1040 #undef type_pf_elem
1041 #undef type_pf_telem
1042 #undef type_pf_data_timeout
1043 #undef type_pf_data_expired
1044 #undef type_pf_data_netmask
1045 #undef type_pf_data_timeout_set
1046
1047 #undef type_pf_elem_add
1048 #undef type_pf_add
1049 #undef type_pf_del
1050 #undef type_pf_test_cidrs
1051 #undef type_pf_test
1052
1053 #undef type_pf_elem_tadd
1054 #undef type_pf_expire
1055 #undef type_pf_tadd
1056 #undef type_pf_tdel
1057 #undef type_pf_ttest_cidrs
1058 #undef type_pf_ttest
1059
1060 #undef type_pf_resize
1061 #undef type_pf_tresize
1062 #undef type_pf_flush
1063 #undef type_pf_destroy
1064 #undef type_pf_head
1065 #undef type_pf_list
1066 #undef type_pf_tlist
1067 #undef type_pf_same_set
1068 #undef type_pf_kadt
1069 #undef type_pf_uadt
1070 #undef type_pf_gc
1071 #undef type_pf_gc_init
1072 #undef type_pf_variant
1073 #undef type_pf_tvariant