1 // SPDX-License-Identifier: GPL-2.0-only 2 3 /* PIPAPO: PIle PAcket POlicies: set for arbitrary concatenations of ranges 4 * 5 * Copyright (c) 2019-2020 Red Hat GmbH 6 * 7 * Author: Stefano Brivio <sbrivio@redhat.com> 8 */ 9 10 /** 11 * DOC: Theory of Operation 12 * 13 * 14 * Problem 15 * ------- 16 * 17 * Match packet bytes against entries composed of ranged or non-ranged packet 18 * field specifiers, mapping them to arbitrary references. For example: 19 * 20 * :: 21 * 22 * --- fields ---> 23 * | [net],[port],[net]... => [reference] 24 * entries [net],[port],[net]... => [reference] 25 * | [net],[port],[net]... => [reference] 26 * V ... 27 * 28 * where [net] fields can be IP ranges or netmasks, and [port] fields are port 29 * ranges. Arbitrary packet fields can be matched. 30 * 31 * 32 * Algorithm Overview 33 * ------------------ 34 * 35 * This algorithm is loosely inspired by [Ligatti 2010], and fundamentally 36 * relies on the consideration that every contiguous range in a space of b bits 37 * can be converted into b * 2 netmasks, from Theorem 3 in [Rottenstreich 2010], 38 * as also illustrated in Section 9 of [Kogan 2014]. 39 * 40 * Classification against a number of entries, that require matching given bits 41 * of a packet field, is performed by grouping those bits in sets of arbitrary 42 * size, and classifying packet bits one group at a time. 43 * 44 * Example: 45 * to match the source port (16 bits) of a packet, we can divide those 16 bits 46 * in 4 groups of 4 bits each. Given the entry: 47 * 0000 0001 0101 1001 48 * and a packet with source port: 49 * 0000 0001 1010 1001 50 * first and second groups match, but the third doesn't. We conclude that the 51 * packet doesn't match the given entry. 52 * 53 * Translate the set to a sequence of lookup tables, one per field. Each table 54 * has two dimensions: bit groups to be matched for a single packet field, and 55 * all the possible values of said groups (buckets). Input entries are 56 * represented as one or more rules, depending on the number of composing 57 * netmasks for the given field specifier, and a group match is indicated as a 58 * set bit, with number corresponding to the rule index, in all the buckets 59 * whose value matches the entry for a given group. 60 * 61 * Rules are mapped between fields through an array of x, n pairs, with each 62 * item mapping a matched rule to one or more rules. The position of the pair in 63 * the array indicates the matched rule to be mapped to the next field, x 64 * indicates the first rule index in the next field, and n the amount of 65 * next-field rules the current rule maps to. 66 * 67 * The mapping array for the last field maps to the desired references. 68 * 69 * To match, we perform table lookups using the values of grouped packet bits, 70 * and use a sequence of bitwise operations to progressively evaluate rule 71 * matching. 72 * 73 * A stand-alone, reference implementation, also including notes about possible 74 * future optimisations, is available at: 75 * https://pipapo.lameexcu.se/ 76 * 77 * Insertion 78 * --------- 79 * 80 * - For each packet field: 81 * 82 * - divide the b packet bits we want to classify into groups of size t, 83 * obtaining ceil(b / t) groups 84 * 85 * Example: match on destination IP address, with t = 4: 32 bits, 8 groups 86 * of 4 bits each 87 * 88 * - allocate a lookup table with one column ("bucket") for each possible 89 * value of a group, and with one row for each group 90 * 91 * Example: 8 groups, 2^4 buckets: 92 * 93 * :: 94 * 95 * bucket 96 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 97 * 0 98 * 1 99 * 2 100 * 3 101 * 4 102 * 5 103 * 6 104 * 7 105 * 106 * - map the bits we want to classify for the current field, for a given 107 * entry, to a single rule for non-ranged and netmask set items, and to one 108 * or multiple rules for ranges. Ranges are expanded to composing netmasks 109 * by pipapo_expand(). 110 * 111 * Example: 2 entries, 10.0.0.5:1024 and 192.168.1.0-192.168.2.1:2048 112 * - rule #0: 10.0.0.5 113 * - rule #1: 192.168.1.0/24 114 * - rule #2: 192.168.2.0/31 115 * 116 * - insert references to the rules in the lookup table, selecting buckets 117 * according to bit values of a rule in the given group. This is done by 118 * pipapo_insert(). 119 * 120 * Example: given: 121 * - rule #0: 10.0.0.5 mapping to buckets 122 * < 0 10 0 0 0 0 0 5 > 123 * - rule #1: 192.168.1.0/24 mapping to buckets 124 * < 12 0 10 8 0 1 < 0..15 > < 0..15 > > 125 * - rule #2: 192.168.2.0/31 mapping to buckets 126 * < 12 0 10 8 0 2 0 < 0..1 > > 127 * 128 * these bits are set in the lookup table: 129 * 130 * :: 131 * 132 * bucket 133 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 134 * 0 0 1,2 135 * 1 1,2 0 136 * 2 0 1,2 137 * 3 0 1,2 138 * 4 0,1,2 139 * 5 0 1 2 140 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 141 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1 142 * 143 * - if this is not the last field in the set, fill a mapping array that maps 144 * rules from the lookup table to rules belonging to the same entry in 145 * the next lookup table, done by pipapo_map(). 146 * 147 * Note that as rules map to contiguous ranges of rules, given how netmask 148 * expansion and insertion is performed, &union nft_pipapo_map_bucket stores 149 * this information as pairs of first rule index, rule count. 150 * 151 * Example: 2 entries, 10.0.0.5:1024 and 192.168.1.0-192.168.2.1:2048, 152 * given lookup table #0 for field 0 (see example above): 153 * 154 * :: 155 * 156 * bucket 157 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 158 * 0 0 1,2 159 * 1 1,2 0 160 * 2 0 1,2 161 * 3 0 1,2 162 * 4 0,1,2 163 * 5 0 1 2 164 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 165 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1 166 * 167 * and lookup table #1 for field 1 with: 168 * - rule #0: 1024 mapping to buckets 169 * < 0 0 4 0 > 170 * - rule #1: 2048 mapping to buckets 171 * < 0 0 5 0 > 172 * 173 * :: 174 * 175 * bucket 176 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 177 * 0 0,1 178 * 1 0,1 179 * 2 0 1 180 * 3 0,1 181 * 182 * we need to map rules for 10.0.0.5 in lookup table #0 (rule #0) to 1024 183 * in lookup table #1 (rule #0) and rules for 192.168.1.0-192.168.2.1 184 * (rules #1, #2) to 2048 in lookup table #2 (rule #1): 185 * 186 * :: 187 * 188 * rule indices in current field: 0 1 2 189 * map to rules in next field: 0 1 1 190 * 191 * - if this is the last field in the set, fill a mapping array that maps 192 * rules from the last lookup table to element pointers, also done by 193 * pipapo_map(). 194 * 195 * Note that, in this implementation, we have two elements (start, end) for 196 * each entry. The pointer to the end element is stored in this array, and 197 * the pointer to the start element is linked from it. 198 * 199 * Example: entry 10.0.0.5:1024 has a corresponding &struct nft_pipapo_elem 200 * pointer, 0x66, and element for 192.168.1.0-192.168.2.1:2048 is at 0x42. 201 * From the rules of lookup table #1 as mapped above: 202 * 203 * :: 204 * 205 * rule indices in last field: 0 1 206 * map to elements: 0x66 0x42 207 * 208 * 209 * Matching 210 * -------- 211 * 212 * We use a result bitmap, with the size of a single lookup table bucket, to 213 * represent the matching state that applies at every algorithm step. This is 214 * done by pipapo_lookup(). 215 * 216 * - For each packet field: 217 * 218 * - start with an all-ones result bitmap (res_map in pipapo_lookup()) 219 * 220 * - perform a lookup into the table corresponding to the current field, 221 * for each group, and at every group, AND the current result bitmap with 222 * the value from the lookup table bucket 223 * 224 * :: 225 * 226 * Example: 192.168.1.5 < 12 0 10 8 0 1 0 5 >, with lookup table from 227 * insertion examples. 228 * Lookup table buckets are at least 3 bits wide, we'll assume 8 bits for 229 * convenience in this example. Initial result bitmap is 0xff, the steps 230 * below show the value of the result bitmap after each group is processed: 231 * 232 * bucket 233 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 234 * 0 0 1,2 235 * result bitmap is now: 0xff & 0x6 [bucket 12] = 0x6 236 * 237 * 1 1,2 0 238 * result bitmap is now: 0x6 & 0x6 [bucket 0] = 0x6 239 * 240 * 2 0 1,2 241 * result bitmap is now: 0x6 & 0x6 [bucket 10] = 0x6 242 * 243 * 3 0 1,2 244 * result bitmap is now: 0x6 & 0x6 [bucket 8] = 0x6 245 * 246 * 4 0,1,2 247 * result bitmap is now: 0x6 & 0x7 [bucket 0] = 0x6 248 * 249 * 5 0 1 2 250 * result bitmap is now: 0x6 & 0x2 [bucket 1] = 0x2 251 * 252 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 253 * result bitmap is now: 0x2 & 0x7 [bucket 0] = 0x2 254 * 255 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1 256 * final result bitmap for this field is: 0x2 & 0x3 [bucket 5] = 0x2 257 * 258 * - at the next field, start with a new, all-zeroes result bitmap. For each 259 * bit set in the previous result bitmap, fill the new result bitmap 260 * (fill_map in pipapo_lookup()) with the rule indices from the 261 * corresponding buckets of the mapping field for this field, done by 262 * pipapo_refill() 263 * 264 * Example: with mapping table from insertion examples, with the current 265 * result bitmap from the previous example, 0x02: 266 * 267 * :: 268 * 269 * rule indices in current field: 0 1 2 270 * map to rules in next field: 0 1 1 271 * 272 * the new result bitmap will be 0x02: rule 1 was set, and rule 1 will be 273 * set. 274 * 275 * We can now extend this example to cover the second iteration of the step 276 * above (lookup and AND bitmap): assuming the port field is 277 * 2048 < 0 0 5 0 >, with starting result bitmap 0x2, and lookup table 278 * for "port" field from pre-computation example: 279 * 280 * :: 281 * 282 * bucket 283 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 284 * 0 0,1 285 * 1 0,1 286 * 2 0 1 287 * 3 0,1 288 * 289 * operations are: 0x2 & 0x3 [bucket 0] & 0x3 [bucket 0] & 0x2 [bucket 5] 290 * & 0x3 [bucket 0], resulting bitmap is 0x2. 291 * 292 * - if this is the last field in the set, look up the value from the mapping 293 * array corresponding to the final result bitmap 294 * 295 * Example: 0x2 resulting bitmap from 192.168.1.5:2048, mapping array for 296 * last field from insertion example: 297 * 298 * :: 299 * 300 * rule indices in last field: 0 1 301 * map to elements: 0x66 0x42 302 * 303 * the matching element is at 0x42. 304 * 305 * 306 * References 307 * ---------- 308 * 309 * [Ligatti 2010] 310 * A Packet-classification Algorithm for Arbitrary Bitmask Rules, with 311 * Automatic Time-space Tradeoffs 312 * Jay Ligatti, Josh Kuhn, and Chris Gage. 313 * Proceedings of the IEEE International Conference on Computer 314 * Communication Networks (ICCCN), August 2010. 315 * https://www.cse.usf.edu/~ligatti/papers/grouper-conf.pdf 316 * 317 * [Rottenstreich 2010] 318 * Worst-Case TCAM Rule Expansion 319 * Ori Rottenstreich and Isaac Keslassy. 320 * 2010 Proceedings IEEE INFOCOM, San Diego, CA, 2010. 321 * http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.212.4592&rep=rep1&type=pdf 322 * 323 * [Kogan 2014] 324 * SAX-PAC (Scalable And eXpressive PAcket Classification) 325 * Kirill Kogan, Sergey Nikolenko, Ori Rottenstreich, William Culhane, 326 * and Patrick Eugster. 327 * Proceedings of the 2014 ACM conference on SIGCOMM, August 2014. 328 * https://www.sigcomm.org/sites/default/files/ccr/papers/2014/August/2619239-2626294.pdf 329 */ 330 331 #include <linux/kernel.h> 332 #include <linux/init.h> 333 #include <linux/module.h> 334 #include <linux/netlink.h> 335 #include <linux/netfilter.h> 336 #include <linux/netfilter/nf_tables.h> 337 #include <net/netfilter/nf_tables_core.h> 338 #include <uapi/linux/netfilter/nf_tables.h> 339 #include <linux/bitmap.h> 340 #include <linux/bitops.h> 341 342 #include "nft_set_pipapo_avx2.h" 343 #include "nft_set_pipapo.h" 344 345 /** 346 * pipapo_refill() - For each set bit, set bits from selected mapping table item 347 * @map: Bitmap to be scanned for set bits 348 * @len: Length of bitmap in longs 349 * @rules: Number of rules in field 350 * @dst: Destination bitmap 351 * @mt: Mapping table containing bit set specifiers 352 * @match_only: Find a single bit and return, don't fill 353 * 354 * Iteration over set bits with __builtin_ctzl(): Daniel Lemire, public domain. 355 * 356 * For each bit set in map, select the bucket from mapping table with index 357 * corresponding to the position of the bit set. Use start bit and amount of 358 * bits specified in bucket to fill region in dst. 359 * 360 * Return: -1 on no match, bit position on 'match_only', 0 otherwise. 361 */ 362 int pipapo_refill(unsigned long *map, unsigned int len, unsigned int rules, 363 unsigned long *dst, 364 const union nft_pipapo_map_bucket *mt, bool match_only) 365 { 366 unsigned long bitset; 367 unsigned int k; 368 int ret = -1; 369 370 for (k = 0; k < len; k++) { 371 bitset = map[k]; 372 while (bitset) { 373 unsigned long t = bitset & -bitset; 374 int r = __builtin_ctzl(bitset); 375 int i = k * BITS_PER_LONG + r; 376 377 if (unlikely(i >= rules)) { 378 map[k] = 0; 379 return -1; 380 } 381 382 if (match_only) { 383 bitmap_clear(map, i, 1); 384 return i; 385 } 386 387 ret = 0; 388 389 bitmap_set(dst, mt[i].to, mt[i].n); 390 391 bitset ^= t; 392 } 393 map[k] = 0; 394 } 395 396 return ret; 397 } 398 399 /** 400 * nft_pipapo_lookup() - Lookup function 401 * @net: Network namespace 402 * @set: nftables API set representation 403 * @key: nftables API element representation containing key data 404 * @ext: nftables API extension pointer, filled with matching reference 405 * 406 * For more details, see DOC: Theory of Operation. 407 * 408 * Return: true on match, false otherwise. 409 */ 410 bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set, 411 const u32 *key, const struct nft_set_ext **ext) 412 { 413 struct nft_pipapo *priv = nft_set_priv(set); 414 struct nft_pipapo_scratch *scratch; 415 unsigned long *res_map, *fill_map; 416 u8 genmask = nft_genmask_cur(net); 417 const struct nft_pipapo_match *m; 418 const struct nft_pipapo_field *f; 419 const u8 *rp = (const u8 *)key; 420 bool map_index; 421 int i; 422 423 local_bh_disable(); 424 425 m = rcu_dereference(priv->match); 426 427 if (unlikely(!m || !*raw_cpu_ptr(m->scratch))) 428 goto out; 429 430 scratch = *raw_cpu_ptr(m->scratch); 431 432 map_index = scratch->map_index; 433 434 res_map = scratch->map + (map_index ? m->bsize_max : 0); 435 fill_map = scratch->map + (map_index ? 0 : m->bsize_max); 436 437 pipapo_resmap_init(m, res_map); 438 439 nft_pipapo_for_each_field(f, i, m) { 440 bool last = i == m->field_count - 1; 441 int b; 442 443 /* For each bit group: select lookup table bucket depending on 444 * packet bytes value, then AND bucket value 445 */ 446 if (likely(f->bb == 8)) 447 pipapo_and_field_buckets_8bit(f, res_map, rp); 448 else 449 pipapo_and_field_buckets_4bit(f, res_map, rp); 450 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4; 451 452 rp += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f); 453 454 /* Now populate the bitmap for the next field, unless this is 455 * the last field, in which case return the matched 'ext' 456 * pointer if any. 457 * 458 * Now res_map contains the matching bitmap, and fill_map is the 459 * bitmap for the next field. 460 */ 461 next_match: 462 b = pipapo_refill(res_map, f->bsize, f->rules, fill_map, f->mt, 463 last); 464 if (b < 0) { 465 scratch->map_index = map_index; 466 local_bh_enable(); 467 468 return false; 469 } 470 471 if (last) { 472 *ext = &f->mt[b].e->ext; 473 if (unlikely(nft_set_elem_expired(*ext) || 474 !nft_set_elem_active(*ext, genmask))) 475 goto next_match; 476 477 /* Last field: we're just returning the key without 478 * filling the initial bitmap for the next field, so the 479 * current inactive bitmap is clean and can be reused as 480 * *next* bitmap (not initial) for the next packet. 481 */ 482 scratch->map_index = map_index; 483 local_bh_enable(); 484 485 return true; 486 } 487 488 /* Swap bitmap indices: res_map is the initial bitmap for the 489 * next field, and fill_map is guaranteed to be all-zeroes at 490 * this point. 491 */ 492 map_index = !map_index; 493 swap(res_map, fill_map); 494 495 rp += NFT_PIPAPO_GROUPS_PADDING(f); 496 } 497 498 out: 499 local_bh_enable(); 500 return false; 501 } 502 503 /** 504 * pipapo_get() - Get matching element reference given key data 505 * @net: Network namespace 506 * @set: nftables API set representation 507 * @m: storage containing active/existing elements 508 * @data: Key data to be matched against existing elements 509 * @genmask: If set, check that element is active in given genmask 510 * @tstamp: timestamp to check for expired elements 511 * @gfp: the type of memory to allocate (see kmalloc). 512 * 513 * This is essentially the same as the lookup function, except that it matches 514 * key data against the uncommitted copy and doesn't use preallocated maps for 515 * bitmap results. 516 * 517 * Return: pointer to &struct nft_pipapo_elem on match, error pointer otherwise. 518 */ 519 static struct nft_pipapo_elem *pipapo_get(const struct net *net, 520 const struct nft_set *set, 521 const struct nft_pipapo_match *m, 522 const u8 *data, u8 genmask, 523 u64 tstamp, gfp_t gfp) 524 { 525 struct nft_pipapo_elem *ret = ERR_PTR(-ENOENT); 526 unsigned long *res_map, *fill_map = NULL; 527 const struct nft_pipapo_field *f; 528 int i; 529 530 if (m->bsize_max == 0) 531 return ret; 532 533 res_map = kmalloc_array(m->bsize_max, sizeof(*res_map), gfp); 534 if (!res_map) { 535 ret = ERR_PTR(-ENOMEM); 536 goto out; 537 } 538 539 fill_map = kcalloc(m->bsize_max, sizeof(*res_map), gfp); 540 if (!fill_map) { 541 ret = ERR_PTR(-ENOMEM); 542 goto out; 543 } 544 545 pipapo_resmap_init(m, res_map); 546 547 nft_pipapo_for_each_field(f, i, m) { 548 bool last = i == m->field_count - 1; 549 int b; 550 551 /* For each bit group: select lookup table bucket depending on 552 * packet bytes value, then AND bucket value 553 */ 554 if (f->bb == 8) 555 pipapo_and_field_buckets_8bit(f, res_map, data); 556 else if (f->bb == 4) 557 pipapo_and_field_buckets_4bit(f, res_map, data); 558 else 559 BUG(); 560 561 data += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f); 562 563 /* Now populate the bitmap for the next field, unless this is 564 * the last field, in which case return the matched 'ext' 565 * pointer if any. 566 * 567 * Now res_map contains the matching bitmap, and fill_map is the 568 * bitmap for the next field. 569 */ 570 next_match: 571 b = pipapo_refill(res_map, f->bsize, f->rules, fill_map, f->mt, 572 last); 573 if (b < 0) 574 goto out; 575 576 if (last) { 577 if (__nft_set_elem_expired(&f->mt[b].e->ext, tstamp)) 578 goto next_match; 579 if ((genmask && 580 !nft_set_elem_active(&f->mt[b].e->ext, genmask))) 581 goto next_match; 582 583 ret = f->mt[b].e; 584 goto out; 585 } 586 587 data += NFT_PIPAPO_GROUPS_PADDING(f); 588 589 /* Swap bitmap indices: fill_map will be the initial bitmap for 590 * the next field (i.e. the new res_map), and res_map is 591 * guaranteed to be all-zeroes at this point, ready to be filled 592 * according to the next mapping table. 593 */ 594 swap(res_map, fill_map); 595 } 596 597 out: 598 kfree(fill_map); 599 kfree(res_map); 600 return ret; 601 } 602 603 /** 604 * nft_pipapo_get() - Get matching element reference given key data 605 * @net: Network namespace 606 * @set: nftables API set representation 607 * @elem: nftables API element representation containing key data 608 * @flags: Unused 609 */ 610 static struct nft_elem_priv * 611 nft_pipapo_get(const struct net *net, const struct nft_set *set, 612 const struct nft_set_elem *elem, unsigned int flags) 613 { 614 struct nft_pipapo *priv = nft_set_priv(set); 615 struct nft_pipapo_match *m = rcu_dereference(priv->match); 616 struct nft_pipapo_elem *e; 617 618 e = pipapo_get(net, set, m, (const u8 *)elem->key.val.data, 619 nft_genmask_cur(net), get_jiffies_64(), 620 GFP_ATOMIC); 621 if (IS_ERR(e)) 622 return ERR_CAST(e); 623 624 return &e->priv; 625 } 626 627 /** 628 * pipapo_realloc_mt() - Reallocate mapping table if needed upon resize 629 * @f: Field containing mapping table 630 * @old_rules: Amount of existing mapped rules 631 * @rules: Amount of new rules to map 632 * 633 * Return: 0 on success, negative error code on failure. 634 */ 635 static int pipapo_realloc_mt(struct nft_pipapo_field *f, 636 unsigned int old_rules, unsigned int rules) 637 { 638 union nft_pipapo_map_bucket *new_mt = NULL, *old_mt = f->mt; 639 const unsigned int extra = PAGE_SIZE / sizeof(*new_mt); 640 unsigned int rules_alloc = rules; 641 642 might_sleep(); 643 644 if (unlikely(rules == 0)) 645 goto out_free; 646 647 /* growing and enough space left, no action needed */ 648 if (rules > old_rules && f->rules_alloc > rules) 649 return 0; 650 651 /* downsize and extra slack has not grown too large */ 652 if (rules < old_rules) { 653 unsigned int remove = f->rules_alloc - rules; 654 655 if (remove < (2u * extra)) 656 return 0; 657 } 658 659 /* If set needs more than one page of memory for rules then 660 * allocate another extra page to avoid frequent reallocation. 661 */ 662 if (rules > extra && 663 check_add_overflow(rules, extra, &rules_alloc)) 664 return -EOVERFLOW; 665 666 new_mt = kvmalloc_array(rules_alloc, sizeof(*new_mt), GFP_KERNEL); 667 if (!new_mt) 668 return -ENOMEM; 669 670 if (old_mt) 671 memcpy(new_mt, old_mt, min(old_rules, rules) * sizeof(*new_mt)); 672 673 if (rules > old_rules) { 674 memset(new_mt + old_rules, 0, 675 (rules - old_rules) * sizeof(*new_mt)); 676 } 677 out_free: 678 f->rules_alloc = rules_alloc; 679 f->mt = new_mt; 680 681 kvfree(old_mt); 682 683 return 0; 684 } 685 686 /** 687 * pipapo_resize() - Resize lookup or mapping table, or both 688 * @f: Field containing lookup and mapping tables 689 * @old_rules: Previous amount of rules in field 690 * @rules: New amount of rules 691 * 692 * Increase, decrease or maintain tables size depending on new amount of rules, 693 * and copy data over. In case the new size is smaller, throw away data for 694 * highest-numbered rules. 695 * 696 * Return: 0 on success, -ENOMEM on allocation failure. 697 */ 698 static int pipapo_resize(struct nft_pipapo_field *f, 699 unsigned int old_rules, unsigned int rules) 700 { 701 long *new_lt = NULL, *new_p, *old_lt = f->lt, *old_p; 702 unsigned int new_bucket_size, copy; 703 int group, bucket, err; 704 705 if (rules >= NFT_PIPAPO_RULE0_MAX) 706 return -ENOSPC; 707 708 new_bucket_size = DIV_ROUND_UP(rules, BITS_PER_LONG); 709 #ifdef NFT_PIPAPO_ALIGN 710 new_bucket_size = roundup(new_bucket_size, 711 NFT_PIPAPO_ALIGN / sizeof(*new_lt)); 712 #endif 713 714 if (new_bucket_size == f->bsize) 715 goto mt; 716 717 if (new_bucket_size > f->bsize) 718 copy = f->bsize; 719 else 720 copy = new_bucket_size; 721 722 new_lt = kvzalloc(f->groups * NFT_PIPAPO_BUCKETS(f->bb) * 723 new_bucket_size * sizeof(*new_lt) + 724 NFT_PIPAPO_ALIGN_HEADROOM, 725 GFP_KERNEL); 726 if (!new_lt) 727 return -ENOMEM; 728 729 new_p = NFT_PIPAPO_LT_ALIGN(new_lt); 730 old_p = NFT_PIPAPO_LT_ALIGN(old_lt); 731 732 for (group = 0; group < f->groups; group++) { 733 for (bucket = 0; bucket < NFT_PIPAPO_BUCKETS(f->bb); bucket++) { 734 memcpy(new_p, old_p, copy * sizeof(*new_p)); 735 new_p += copy; 736 old_p += copy; 737 738 if (new_bucket_size > f->bsize) 739 new_p += new_bucket_size - f->bsize; 740 else 741 old_p += f->bsize - new_bucket_size; 742 } 743 } 744 745 mt: 746 err = pipapo_realloc_mt(f, old_rules, rules); 747 if (err) { 748 kvfree(new_lt); 749 return err; 750 } 751 752 if (new_lt) { 753 f->bsize = new_bucket_size; 754 f->lt = new_lt; 755 kvfree(old_lt); 756 } 757 758 return 0; 759 } 760 761 /** 762 * pipapo_bucket_set() - Set rule bit in bucket given group and group value 763 * @f: Field containing lookup table 764 * @rule: Rule index 765 * @group: Group index 766 * @v: Value of bit group 767 */ 768 static void pipapo_bucket_set(struct nft_pipapo_field *f, int rule, int group, 769 int v) 770 { 771 unsigned long *pos; 772 773 pos = NFT_PIPAPO_LT_ALIGN(f->lt); 774 pos += f->bsize * NFT_PIPAPO_BUCKETS(f->bb) * group; 775 pos += f->bsize * v; 776 777 __set_bit(rule, pos); 778 } 779 780 /** 781 * pipapo_lt_4b_to_8b() - Switch lookup table group width from 4 bits to 8 bits 782 * @old_groups: Number of current groups 783 * @bsize: Size of one bucket, in longs 784 * @old_lt: Pointer to the current lookup table 785 * @new_lt: Pointer to the new, pre-allocated lookup table 786 * 787 * Each bucket with index b in the new lookup table, belonging to group g, is 788 * filled with the bit intersection between: 789 * - bucket with index given by the upper 4 bits of b, from group g, and 790 * - bucket with index given by the lower 4 bits of b, from group g + 1 791 * 792 * That is, given buckets from the new lookup table N(x, y) and the old lookup 793 * table O(x, y), with x bucket index, and y group index: 794 * 795 * N(b, g) := O(b / 16, g) & O(b % 16, g + 1) 796 * 797 * This ensures equivalence of the matching results on lookup. Two examples in 798 * pictures: 799 * 800 * bucket 801 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ... 254 255 802 * 0 ^ 803 * 1 | ^ 804 * ... ( & ) | 805 * / \ | 806 * / \ .-( & )-. 807 * / bucket \ | | 808 * group 0 / 1 2 3 \ 4 5 6 7 8 9 10 11 12 13 |14 15 | 809 * 0 / \ | | 810 * 1 \ | | 811 * 2 | --' 812 * 3 '- 813 * ... 814 */ 815 static void pipapo_lt_4b_to_8b(int old_groups, int bsize, 816 unsigned long *old_lt, unsigned long *new_lt) 817 { 818 int g, b, i; 819 820 for (g = 0; g < old_groups / 2; g++) { 821 int src_g0 = g * 2, src_g1 = g * 2 + 1; 822 823 for (b = 0; b < NFT_PIPAPO_BUCKETS(8); b++) { 824 int src_b0 = b / NFT_PIPAPO_BUCKETS(4); 825 int src_b1 = b % NFT_PIPAPO_BUCKETS(4); 826 int src_i0 = src_g0 * NFT_PIPAPO_BUCKETS(4) + src_b0; 827 int src_i1 = src_g1 * NFT_PIPAPO_BUCKETS(4) + src_b1; 828 829 for (i = 0; i < bsize; i++) { 830 *new_lt = old_lt[src_i0 * bsize + i] & 831 old_lt[src_i1 * bsize + i]; 832 new_lt++; 833 } 834 } 835 } 836 } 837 838 /** 839 * pipapo_lt_8b_to_4b() - Switch lookup table group width from 8 bits to 4 bits 840 * @old_groups: Number of current groups 841 * @bsize: Size of one bucket, in longs 842 * @old_lt: Pointer to the current lookup table 843 * @new_lt: Pointer to the new, pre-allocated lookup table 844 * 845 * Each bucket with index b in the new lookup table, belonging to group g, is 846 * filled with the bit union of: 847 * - all the buckets with index such that the upper four bits of the lower byte 848 * equal b, from group g, with g odd 849 * - all the buckets with index such that the lower four bits equal b, from 850 * group g, with g even 851 * 852 * That is, given buckets from the new lookup table N(x, y) and the old lookup 853 * table O(x, y), with x bucket index, and y group index: 854 * 855 * - with g odd: N(b, g) := U(O(x, g) for each x : x = (b & 0xf0) >> 4) 856 * - with g even: N(b, g) := U(O(x, g) for each x : x = b & 0x0f) 857 * 858 * where U() denotes the arbitrary union operation (binary OR of n terms). This 859 * ensures equivalence of the matching results on lookup. 860 */ 861 static void pipapo_lt_8b_to_4b(int old_groups, int bsize, 862 unsigned long *old_lt, unsigned long *new_lt) 863 { 864 int g, b, bsrc, i; 865 866 memset(new_lt, 0, old_groups * 2 * NFT_PIPAPO_BUCKETS(4) * bsize * 867 sizeof(unsigned long)); 868 869 for (g = 0; g < old_groups * 2; g += 2) { 870 int src_g = g / 2; 871 872 for (b = 0; b < NFT_PIPAPO_BUCKETS(4); b++) { 873 for (bsrc = NFT_PIPAPO_BUCKETS(8) * src_g; 874 bsrc < NFT_PIPAPO_BUCKETS(8) * (src_g + 1); 875 bsrc++) { 876 if (((bsrc & 0xf0) >> 4) != b) 877 continue; 878 879 for (i = 0; i < bsize; i++) 880 new_lt[i] |= old_lt[bsrc * bsize + i]; 881 } 882 883 new_lt += bsize; 884 } 885 886 for (b = 0; b < NFT_PIPAPO_BUCKETS(4); b++) { 887 for (bsrc = NFT_PIPAPO_BUCKETS(8) * src_g; 888 bsrc < NFT_PIPAPO_BUCKETS(8) * (src_g + 1); 889 bsrc++) { 890 if ((bsrc & 0x0f) != b) 891 continue; 892 893 for (i = 0; i < bsize; i++) 894 new_lt[i] |= old_lt[bsrc * bsize + i]; 895 } 896 897 new_lt += bsize; 898 } 899 } 900 } 901 902 /** 903 * pipapo_lt_bits_adjust() - Adjust group size for lookup table if needed 904 * @f: Field containing lookup table 905 */ 906 static void pipapo_lt_bits_adjust(struct nft_pipapo_field *f) 907 { 908 unsigned int groups, bb; 909 unsigned long *new_lt; 910 size_t lt_size; 911 912 lt_size = f->groups * NFT_PIPAPO_BUCKETS(f->bb) * f->bsize * 913 sizeof(*f->lt); 914 915 if (f->bb == NFT_PIPAPO_GROUP_BITS_SMALL_SET && 916 lt_size > NFT_PIPAPO_LT_SIZE_HIGH) { 917 groups = f->groups * 2; 918 bb = NFT_PIPAPO_GROUP_BITS_LARGE_SET; 919 920 lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize * 921 sizeof(*f->lt); 922 } else if (f->bb == NFT_PIPAPO_GROUP_BITS_LARGE_SET && 923 lt_size < NFT_PIPAPO_LT_SIZE_LOW) { 924 groups = f->groups / 2; 925 bb = NFT_PIPAPO_GROUP_BITS_SMALL_SET; 926 927 lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize * 928 sizeof(*f->lt); 929 930 /* Don't increase group width if the resulting lookup table size 931 * would exceed the upper size threshold for a "small" set. 932 */ 933 if (lt_size > NFT_PIPAPO_LT_SIZE_HIGH) 934 return; 935 } else { 936 return; 937 } 938 939 new_lt = kvzalloc(lt_size + NFT_PIPAPO_ALIGN_HEADROOM, GFP_KERNEL); 940 if (!new_lt) 941 return; 942 943 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4; 944 if (f->bb == 4 && bb == 8) { 945 pipapo_lt_4b_to_8b(f->groups, f->bsize, 946 NFT_PIPAPO_LT_ALIGN(f->lt), 947 NFT_PIPAPO_LT_ALIGN(new_lt)); 948 } else if (f->bb == 8 && bb == 4) { 949 pipapo_lt_8b_to_4b(f->groups, f->bsize, 950 NFT_PIPAPO_LT_ALIGN(f->lt), 951 NFT_PIPAPO_LT_ALIGN(new_lt)); 952 } else { 953 BUG(); 954 } 955 956 f->groups = groups; 957 f->bb = bb; 958 kvfree(f->lt); 959 f->lt = new_lt; 960 } 961 962 /** 963 * pipapo_insert() - Insert new rule in field given input key and mask length 964 * @f: Field containing lookup table 965 * @k: Input key for classification, without nftables padding 966 * @mask_bits: Length of mask; matches field length for non-ranged entry 967 * 968 * Insert a new rule reference in lookup buckets corresponding to k and 969 * mask_bits. 970 * 971 * Return: 1 on success (one rule inserted), negative error code on failure. 972 */ 973 static int pipapo_insert(struct nft_pipapo_field *f, const uint8_t *k, 974 int mask_bits) 975 { 976 unsigned int rule = f->rules, group, ret, bit_offset = 0; 977 978 ret = pipapo_resize(f, f->rules, f->rules + 1); 979 if (ret) 980 return ret; 981 982 f->rules++; 983 984 for (group = 0; group < f->groups; group++) { 985 int i, v; 986 u8 mask; 987 988 v = k[group / (BITS_PER_BYTE / f->bb)]; 989 v &= GENMASK(BITS_PER_BYTE - bit_offset - 1, 0); 990 v >>= (BITS_PER_BYTE - bit_offset) - f->bb; 991 992 bit_offset += f->bb; 993 bit_offset %= BITS_PER_BYTE; 994 995 if (mask_bits >= (group + 1) * f->bb) { 996 /* Not masked */ 997 pipapo_bucket_set(f, rule, group, v); 998 } else if (mask_bits <= group * f->bb) { 999 /* Completely masked */ 1000 for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++) 1001 pipapo_bucket_set(f, rule, group, i); 1002 } else { 1003 /* The mask limit falls on this group */ 1004 mask = GENMASK(f->bb - 1, 0); 1005 mask >>= mask_bits - group * f->bb; 1006 for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++) { 1007 if ((i & ~mask) == (v & ~mask)) 1008 pipapo_bucket_set(f, rule, group, i); 1009 } 1010 } 1011 } 1012 1013 pipapo_lt_bits_adjust(f); 1014 1015 return 1; 1016 } 1017 1018 /** 1019 * pipapo_step_diff() - Check if setting @step bit in netmask would change it 1020 * @base: Mask we are expanding 1021 * @step: Step bit for given expansion step 1022 * @len: Total length of mask space (set and unset bits), bytes 1023 * 1024 * Convenience function for mask expansion. 1025 * 1026 * Return: true if step bit changes mask (i.e. isn't set), false otherwise. 1027 */ 1028 static bool pipapo_step_diff(u8 *base, int step, int len) 1029 { 1030 /* Network order, byte-addressed */ 1031 #ifdef __BIG_ENDIAN__ 1032 return !(BIT(step % BITS_PER_BYTE) & base[step / BITS_PER_BYTE]); 1033 #else 1034 return !(BIT(step % BITS_PER_BYTE) & 1035 base[len - 1 - step / BITS_PER_BYTE]); 1036 #endif 1037 } 1038 1039 /** 1040 * pipapo_step_after_end() - Check if mask exceeds range end with given step 1041 * @base: Mask we are expanding 1042 * @end: End of range 1043 * @step: Step bit for given expansion step, highest bit to be set 1044 * @len: Total length of mask space (set and unset bits), bytes 1045 * 1046 * Convenience function for mask expansion. 1047 * 1048 * Return: true if mask exceeds range setting step bits, false otherwise. 1049 */ 1050 static bool pipapo_step_after_end(const u8 *base, const u8 *end, int step, 1051 int len) 1052 { 1053 u8 tmp[NFT_PIPAPO_MAX_BYTES]; 1054 int i; 1055 1056 memcpy(tmp, base, len); 1057 1058 /* Network order, byte-addressed */ 1059 for (i = 0; i <= step; i++) 1060 #ifdef __BIG_ENDIAN__ 1061 tmp[i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE); 1062 #else 1063 tmp[len - 1 - i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE); 1064 #endif 1065 1066 return memcmp(tmp, end, len) > 0; 1067 } 1068 1069 /** 1070 * pipapo_base_sum() - Sum step bit to given len-sized netmask base with carry 1071 * @base: Netmask base 1072 * @step: Step bit to sum 1073 * @len: Netmask length, bytes 1074 */ 1075 static void pipapo_base_sum(u8 *base, int step, int len) 1076 { 1077 bool carry = false; 1078 int i; 1079 1080 /* Network order, byte-addressed */ 1081 #ifdef __BIG_ENDIAN__ 1082 for (i = step / BITS_PER_BYTE; i < len; i++) { 1083 #else 1084 for (i = len - 1 - step / BITS_PER_BYTE; i >= 0; i--) { 1085 #endif 1086 if (carry) 1087 base[i]++; 1088 else 1089 base[i] += 1 << (step % BITS_PER_BYTE); 1090 1091 if (base[i]) 1092 break; 1093 1094 carry = true; 1095 } 1096 } 1097 1098 /** 1099 * pipapo_expand() - Expand to composing netmasks, insert into lookup table 1100 * @f: Field containing lookup table 1101 * @start: Start of range 1102 * @end: End of range 1103 * @len: Length of value in bits 1104 * 1105 * Expand range to composing netmasks and insert corresponding rule references 1106 * in lookup buckets. 1107 * 1108 * Return: number of inserted rules on success, negative error code on failure. 1109 */ 1110 static int pipapo_expand(struct nft_pipapo_field *f, 1111 const u8 *start, const u8 *end, int len) 1112 { 1113 int step, masks = 0, bytes = DIV_ROUND_UP(len, BITS_PER_BYTE); 1114 u8 base[NFT_PIPAPO_MAX_BYTES]; 1115 1116 memcpy(base, start, bytes); 1117 while (memcmp(base, end, bytes) <= 0) { 1118 int err; 1119 1120 step = 0; 1121 while (pipapo_step_diff(base, step, bytes)) { 1122 if (pipapo_step_after_end(base, end, step, bytes)) 1123 break; 1124 1125 step++; 1126 if (step >= len) { 1127 if (!masks) { 1128 err = pipapo_insert(f, base, 0); 1129 if (err < 0) 1130 return err; 1131 masks = 1; 1132 } 1133 goto out; 1134 } 1135 } 1136 1137 err = pipapo_insert(f, base, len - step); 1138 1139 if (err < 0) 1140 return err; 1141 1142 masks++; 1143 pipapo_base_sum(base, step, bytes); 1144 } 1145 out: 1146 return masks; 1147 } 1148 1149 /** 1150 * pipapo_map() - Insert rules in mapping tables, mapping them between fields 1151 * @m: Matching data, including mapping table 1152 * @map: Table of rule maps: array of first rule and amount of rules 1153 * in next field a given rule maps to, for each field 1154 * @e: For last field, nft_set_ext pointer matching rules map to 1155 */ 1156 static void pipapo_map(struct nft_pipapo_match *m, 1157 union nft_pipapo_map_bucket map[NFT_PIPAPO_MAX_FIELDS], 1158 struct nft_pipapo_elem *e) 1159 { 1160 struct nft_pipapo_field *f; 1161 int i, j; 1162 1163 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) { 1164 for (j = 0; j < map[i].n; j++) { 1165 f->mt[map[i].to + j].to = map[i + 1].to; 1166 f->mt[map[i].to + j].n = map[i + 1].n; 1167 } 1168 } 1169 1170 /* Last field: map to ext instead of mapping to next field */ 1171 for (j = 0; j < map[i].n; j++) 1172 f->mt[map[i].to + j].e = e; 1173 } 1174 1175 /** 1176 * pipapo_free_scratch() - Free per-CPU map at original (not aligned) address 1177 * @m: Matching data 1178 * @cpu: CPU number 1179 */ 1180 static void pipapo_free_scratch(const struct nft_pipapo_match *m, unsigned int cpu) 1181 { 1182 struct nft_pipapo_scratch *s; 1183 void *mem; 1184 1185 s = *per_cpu_ptr(m->scratch, cpu); 1186 if (!s) 1187 return; 1188 1189 mem = s; 1190 mem -= s->align_off; 1191 kfree(mem); 1192 } 1193 1194 /** 1195 * pipapo_realloc_scratch() - Reallocate scratch maps for partial match results 1196 * @clone: Copy of matching data with pending insertions and deletions 1197 * @bsize_max: Maximum bucket size, scratch maps cover two buckets 1198 * 1199 * Return: 0 on success, -ENOMEM on failure. 1200 */ 1201 static int pipapo_realloc_scratch(struct nft_pipapo_match *clone, 1202 unsigned long bsize_max) 1203 { 1204 int i; 1205 1206 for_each_possible_cpu(i) { 1207 struct nft_pipapo_scratch *scratch; 1208 #ifdef NFT_PIPAPO_ALIGN 1209 void *scratch_aligned; 1210 u32 align_off; 1211 #endif 1212 scratch = kzalloc_node(struct_size(scratch, map, 1213 bsize_max * 2) + 1214 NFT_PIPAPO_ALIGN_HEADROOM, 1215 GFP_KERNEL, cpu_to_node(i)); 1216 if (!scratch) { 1217 /* On failure, there's no need to undo previous 1218 * allocations: this means that some scratch maps have 1219 * a bigger allocated size now (this is only called on 1220 * insertion), but the extra space won't be used by any 1221 * CPU as new elements are not inserted and m->bsize_max 1222 * is not updated. 1223 */ 1224 return -ENOMEM; 1225 } 1226 1227 pipapo_free_scratch(clone, i); 1228 1229 #ifdef NFT_PIPAPO_ALIGN 1230 /* Align &scratch->map (not the struct itself): the extra 1231 * %NFT_PIPAPO_ALIGN_HEADROOM bytes passed to kzalloc_node() 1232 * above guarantee we can waste up to those bytes in order 1233 * to align the map field regardless of its offset within 1234 * the struct. 1235 */ 1236 BUILD_BUG_ON(offsetof(struct nft_pipapo_scratch, map) > NFT_PIPAPO_ALIGN_HEADROOM); 1237 1238 scratch_aligned = NFT_PIPAPO_LT_ALIGN(&scratch->map); 1239 scratch_aligned -= offsetof(struct nft_pipapo_scratch, map); 1240 align_off = scratch_aligned - (void *)scratch; 1241 1242 scratch = scratch_aligned; 1243 scratch->align_off = align_off; 1244 #endif 1245 *per_cpu_ptr(clone->scratch, i) = scratch; 1246 } 1247 1248 return 0; 1249 } 1250 1251 static bool nft_pipapo_transaction_mutex_held(const struct nft_set *set) 1252 { 1253 #ifdef CONFIG_PROVE_LOCKING 1254 const struct net *net = read_pnet(&set->net); 1255 1256 return lockdep_is_held(&nft_pernet(net)->commit_mutex); 1257 #else 1258 return true; 1259 #endif 1260 } 1261 1262 static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old); 1263 1264 /** 1265 * pipapo_maybe_clone() - Build clone for pending data changes, if not existing 1266 * @set: nftables API set representation 1267 * 1268 * Return: newly created or existing clone, if any. NULL on allocation failure 1269 */ 1270 static struct nft_pipapo_match *pipapo_maybe_clone(const struct nft_set *set) 1271 { 1272 struct nft_pipapo *priv = nft_set_priv(set); 1273 struct nft_pipapo_match *m; 1274 1275 if (priv->clone) 1276 return priv->clone; 1277 1278 m = rcu_dereference_protected(priv->match, 1279 nft_pipapo_transaction_mutex_held(set)); 1280 priv->clone = pipapo_clone(m); 1281 1282 return priv->clone; 1283 } 1284 1285 /** 1286 * nft_pipapo_insert() - Validate and insert ranged elements 1287 * @net: Network namespace 1288 * @set: nftables API set representation 1289 * @elem: nftables API element representation containing key data 1290 * @elem_priv: Filled with pointer to &struct nft_set_ext in inserted element 1291 * 1292 * Return: 0 on success, error pointer on failure. 1293 */ 1294 static int nft_pipapo_insert(const struct net *net, const struct nft_set *set, 1295 const struct nft_set_elem *elem, 1296 struct nft_elem_priv **elem_priv) 1297 { 1298 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); 1299 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1300 const u8 *start = (const u8 *)elem->key.val.data, *end; 1301 struct nft_pipapo_match *m = pipapo_maybe_clone(set); 1302 u8 genmask = nft_genmask_next(net); 1303 struct nft_pipapo_elem *e, *dup; 1304 u64 tstamp = nft_net_tstamp(net); 1305 struct nft_pipapo_field *f; 1306 const u8 *start_p, *end_p; 1307 int i, bsize_max, err = 0; 1308 1309 if (!m) 1310 return -ENOMEM; 1311 1312 if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) 1313 end = (const u8 *)nft_set_ext_key_end(ext)->data; 1314 else 1315 end = start; 1316 1317 dup = pipapo_get(net, set, m, start, genmask, tstamp, GFP_KERNEL); 1318 if (!IS_ERR(dup)) { 1319 /* Check if we already have the same exact entry */ 1320 const struct nft_data *dup_key, *dup_end; 1321 1322 dup_key = nft_set_ext_key(&dup->ext); 1323 if (nft_set_ext_exists(&dup->ext, NFT_SET_EXT_KEY_END)) 1324 dup_end = nft_set_ext_key_end(&dup->ext); 1325 else 1326 dup_end = dup_key; 1327 1328 if (!memcmp(start, dup_key->data, sizeof(*dup_key->data)) && 1329 !memcmp(end, dup_end->data, sizeof(*dup_end->data))) { 1330 *elem_priv = &dup->priv; 1331 return -EEXIST; 1332 } 1333 1334 return -ENOTEMPTY; 1335 } 1336 1337 if (PTR_ERR(dup) == -ENOENT) { 1338 /* Look for partially overlapping entries */ 1339 dup = pipapo_get(net, set, m, end, nft_genmask_next(net), tstamp, 1340 GFP_KERNEL); 1341 } 1342 1343 if (PTR_ERR(dup) != -ENOENT) { 1344 if (IS_ERR(dup)) 1345 return PTR_ERR(dup); 1346 *elem_priv = &dup->priv; 1347 return -ENOTEMPTY; 1348 } 1349 1350 /* Validate */ 1351 start_p = start; 1352 end_p = end; 1353 1354 /* some helpers return -1, or 0 >= for valid rule pos, 1355 * so we cannot support more than INT_MAX rules at this time. 1356 */ 1357 BUILD_BUG_ON(NFT_PIPAPO_RULE0_MAX > INT_MAX); 1358 1359 nft_pipapo_for_each_field(f, i, m) { 1360 if (f->rules >= NFT_PIPAPO_RULE0_MAX) 1361 return -ENOSPC; 1362 1363 if (memcmp(start_p, end_p, 1364 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) > 0) 1365 return -EINVAL; 1366 1367 start_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1368 end_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1369 } 1370 1371 /* Insert */ 1372 bsize_max = m->bsize_max; 1373 1374 nft_pipapo_for_each_field(f, i, m) { 1375 int ret; 1376 1377 rulemap[i].to = f->rules; 1378 1379 ret = memcmp(start, end, 1380 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)); 1381 if (!ret) 1382 ret = pipapo_insert(f, start, f->groups * f->bb); 1383 else 1384 ret = pipapo_expand(f, start, end, f->groups * f->bb); 1385 1386 if (ret < 0) 1387 return ret; 1388 1389 if (f->bsize > bsize_max) 1390 bsize_max = f->bsize; 1391 1392 rulemap[i].n = ret; 1393 1394 start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1395 end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1396 } 1397 1398 if (!*get_cpu_ptr(m->scratch) || bsize_max > m->bsize_max) { 1399 put_cpu_ptr(m->scratch); 1400 1401 err = pipapo_realloc_scratch(m, bsize_max); 1402 if (err) 1403 return err; 1404 1405 m->bsize_max = bsize_max; 1406 } else { 1407 put_cpu_ptr(m->scratch); 1408 } 1409 1410 e = nft_elem_priv_cast(elem->priv); 1411 *elem_priv = &e->priv; 1412 1413 pipapo_map(m, rulemap, e); 1414 1415 return 0; 1416 } 1417 1418 /** 1419 * pipapo_clone() - Clone matching data to create new working copy 1420 * @old: Existing matching data 1421 * 1422 * Return: copy of matching data passed as 'old' or NULL. 1423 */ 1424 static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old) 1425 { 1426 struct nft_pipapo_field *dst, *src; 1427 struct nft_pipapo_match *new; 1428 int i; 1429 1430 new = kmalloc(struct_size(new, f, old->field_count), GFP_KERNEL); 1431 if (!new) 1432 return NULL; 1433 1434 new->field_count = old->field_count; 1435 new->bsize_max = old->bsize_max; 1436 1437 new->scratch = alloc_percpu(*new->scratch); 1438 if (!new->scratch) 1439 goto out_scratch; 1440 1441 for_each_possible_cpu(i) 1442 *per_cpu_ptr(new->scratch, i) = NULL; 1443 1444 if (pipapo_realloc_scratch(new, old->bsize_max)) 1445 goto out_scratch_realloc; 1446 1447 rcu_head_init(&new->rcu); 1448 1449 src = old->f; 1450 dst = new->f; 1451 1452 for (i = 0; i < old->field_count; i++) { 1453 unsigned long *new_lt; 1454 1455 memcpy(dst, src, offsetof(struct nft_pipapo_field, lt)); 1456 1457 new_lt = kvzalloc(src->groups * NFT_PIPAPO_BUCKETS(src->bb) * 1458 src->bsize * sizeof(*dst->lt) + 1459 NFT_PIPAPO_ALIGN_HEADROOM, 1460 GFP_KERNEL); 1461 if (!new_lt) 1462 goto out_lt; 1463 1464 dst->lt = new_lt; 1465 1466 memcpy(NFT_PIPAPO_LT_ALIGN(new_lt), 1467 NFT_PIPAPO_LT_ALIGN(src->lt), 1468 src->bsize * sizeof(*dst->lt) * 1469 src->groups * NFT_PIPAPO_BUCKETS(src->bb)); 1470 1471 if (src->rules > 0) { 1472 dst->mt = kvmalloc_array(src->rules_alloc, 1473 sizeof(*src->mt), GFP_KERNEL); 1474 if (!dst->mt) 1475 goto out_mt; 1476 1477 memcpy(dst->mt, src->mt, src->rules * sizeof(*src->mt)); 1478 } else { 1479 dst->mt = NULL; 1480 dst->rules_alloc = 0; 1481 } 1482 1483 src++; 1484 dst++; 1485 } 1486 1487 return new; 1488 1489 out_mt: 1490 kvfree(dst->lt); 1491 out_lt: 1492 for (dst--; i > 0; i--) { 1493 kvfree(dst->mt); 1494 kvfree(dst->lt); 1495 dst--; 1496 } 1497 out_scratch_realloc: 1498 for_each_possible_cpu(i) 1499 pipapo_free_scratch(new, i); 1500 out_scratch: 1501 free_percpu(new->scratch); 1502 kfree(new); 1503 1504 return NULL; 1505 } 1506 1507 /** 1508 * pipapo_rules_same_key() - Get number of rules originated from the same entry 1509 * @f: Field containing mapping table 1510 * @first: Index of first rule in set of rules mapping to same entry 1511 * 1512 * Using the fact that all rules in a field that originated from the same entry 1513 * will map to the same set of rules in the next field, or to the same element 1514 * reference, return the cardinality of the set of rules that originated from 1515 * the same entry as the rule with index @first, @first rule included. 1516 * 1517 * In pictures: 1518 * rules 1519 * field #0 0 1 2 3 4 1520 * map to: 0 1 2-4 2-4 5-9 1521 * . . ....... . ... 1522 * | | | | \ \ 1523 * | | | | \ \ 1524 * | | | | \ \ 1525 * ' ' ' ' ' \ 1526 * in field #1 0 1 2 3 4 5 ... 1527 * 1528 * if this is called for rule 2 on field #0, it will return 3, as also rules 2 1529 * and 3 in field 0 map to the same set of rules (2, 3, 4) in the next field. 1530 * 1531 * For the last field in a set, we can rely on associated entries to map to the 1532 * same element references. 1533 * 1534 * Return: Number of rules that originated from the same entry as @first. 1535 */ 1536 static unsigned int pipapo_rules_same_key(struct nft_pipapo_field *f, unsigned int first) 1537 { 1538 struct nft_pipapo_elem *e = NULL; /* Keep gcc happy */ 1539 unsigned int r; 1540 1541 for (r = first; r < f->rules; r++) { 1542 if (r != first && e != f->mt[r].e) 1543 return r - first; 1544 1545 e = f->mt[r].e; 1546 } 1547 1548 if (r != first) 1549 return r - first; 1550 1551 return 0; 1552 } 1553 1554 /** 1555 * pipapo_unmap() - Remove rules from mapping tables, renumber remaining ones 1556 * @mt: Mapping array 1557 * @rules: Original amount of rules in mapping table 1558 * @start: First rule index to be removed 1559 * @n: Amount of rules to be removed 1560 * @to_offset: First rule index, in next field, this group of rules maps to 1561 * @is_last: If this is the last field, delete reference from mapping array 1562 * 1563 * This is used to unmap rules from the mapping table for a single field, 1564 * maintaining consistency and compactness for the existing ones. 1565 * 1566 * In pictures: let's assume that we want to delete rules 2 and 3 from the 1567 * following mapping array: 1568 * 1569 * rules 1570 * 0 1 2 3 4 1571 * map to: 4-10 4-10 11-15 11-15 16-18 1572 * 1573 * the result will be: 1574 * 1575 * rules 1576 * 0 1 2 1577 * map to: 4-10 4-10 11-13 1578 * 1579 * for fields before the last one. In case this is the mapping table for the 1580 * last field in a set, and rules map to pointers to &struct nft_pipapo_elem: 1581 * 1582 * rules 1583 * 0 1 2 3 4 1584 * element pointers: 0x42 0x42 0x33 0x33 0x44 1585 * 1586 * the result will be: 1587 * 1588 * rules 1589 * 0 1 2 1590 * element pointers: 0x42 0x42 0x44 1591 */ 1592 static void pipapo_unmap(union nft_pipapo_map_bucket *mt, unsigned int rules, 1593 unsigned int start, unsigned int n, 1594 unsigned int to_offset, bool is_last) 1595 { 1596 int i; 1597 1598 memmove(mt + start, mt + start + n, (rules - start - n) * sizeof(*mt)); 1599 memset(mt + rules - n, 0, n * sizeof(*mt)); 1600 1601 if (is_last) 1602 return; 1603 1604 for (i = start; i < rules - n; i++) 1605 mt[i].to -= to_offset; 1606 } 1607 1608 /** 1609 * pipapo_drop() - Delete entry from lookup and mapping tables, given rule map 1610 * @m: Matching data 1611 * @rulemap: Table of rule maps, arrays of first rule and amount of rules 1612 * in next field a given entry maps to, for each field 1613 * 1614 * For each rule in lookup table buckets mapping to this set of rules, drop 1615 * all bits set in lookup table mapping. In pictures, assuming we want to drop 1616 * rules 0 and 1 from this lookup table: 1617 * 1618 * bucket 1619 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1620 * 0 0 1,2 1621 * 1 1,2 0 1622 * 2 0 1,2 1623 * 3 0 1,2 1624 * 4 0,1,2 1625 * 5 0 1 2 1626 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1627 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1 1628 * 1629 * rule 2 becomes rule 0, and the result will be: 1630 * 1631 * bucket 1632 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1633 * 0 0 1634 * 1 0 1635 * 2 0 1636 * 3 0 1637 * 4 0 1638 * 5 0 1639 * 6 0 1640 * 7 0 0 1641 * 1642 * once this is done, call unmap() to drop all the corresponding rule references 1643 * from mapping tables. 1644 */ 1645 static void pipapo_drop(struct nft_pipapo_match *m, 1646 union nft_pipapo_map_bucket rulemap[]) 1647 { 1648 struct nft_pipapo_field *f; 1649 int i; 1650 1651 nft_pipapo_for_each_field(f, i, m) { 1652 int g; 1653 1654 for (g = 0; g < f->groups; g++) { 1655 unsigned long *pos; 1656 int b; 1657 1658 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + g * 1659 NFT_PIPAPO_BUCKETS(f->bb) * f->bsize; 1660 1661 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) { 1662 bitmap_cut(pos, pos, rulemap[i].to, 1663 rulemap[i].n, 1664 f->bsize * BITS_PER_LONG); 1665 1666 pos += f->bsize; 1667 } 1668 } 1669 1670 pipapo_unmap(f->mt, f->rules, rulemap[i].to, rulemap[i].n, 1671 rulemap[i + 1].n, i == m->field_count - 1); 1672 if (pipapo_resize(f, f->rules, f->rules - rulemap[i].n)) { 1673 /* We can ignore this, a failure to shrink tables down 1674 * doesn't make tables invalid. 1675 */ 1676 ; 1677 } 1678 f->rules -= rulemap[i].n; 1679 1680 pipapo_lt_bits_adjust(f); 1681 } 1682 } 1683 1684 static void nft_pipapo_gc_deactivate(struct net *net, struct nft_set *set, 1685 struct nft_pipapo_elem *e) 1686 1687 { 1688 nft_setelem_data_deactivate(net, set, &e->priv); 1689 } 1690 1691 /** 1692 * pipapo_gc() - Drop expired entries from set, destroy start and end elements 1693 * @set: nftables API set representation 1694 * @m: Matching data 1695 */ 1696 static void pipapo_gc(struct nft_set *set, struct nft_pipapo_match *m) 1697 { 1698 struct nft_pipapo *priv = nft_set_priv(set); 1699 struct net *net = read_pnet(&set->net); 1700 unsigned int rules_f0, first_rule = 0; 1701 u64 tstamp = nft_net_tstamp(net); 1702 struct nft_pipapo_elem *e; 1703 struct nft_trans_gc *gc; 1704 1705 gc = nft_trans_gc_alloc(set, 0, GFP_KERNEL); 1706 if (!gc) 1707 return; 1708 1709 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { 1710 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1711 const struct nft_pipapo_field *f; 1712 unsigned int i, start, rules_fx; 1713 1714 start = first_rule; 1715 rules_fx = rules_f0; 1716 1717 nft_pipapo_for_each_field(f, i, m) { 1718 rulemap[i].to = start; 1719 rulemap[i].n = rules_fx; 1720 1721 if (i < m->field_count - 1) { 1722 rules_fx = f->mt[start].n; 1723 start = f->mt[start].to; 1724 } 1725 } 1726 1727 /* Pick the last field, and its last index */ 1728 f--; 1729 i--; 1730 e = f->mt[rulemap[i].to].e; 1731 1732 /* synchronous gc never fails, there is no need to set on 1733 * NFT_SET_ELEM_DEAD_BIT. 1734 */ 1735 if (__nft_set_elem_expired(&e->ext, tstamp)) { 1736 gc = nft_trans_gc_queue_sync(gc, GFP_KERNEL); 1737 if (!gc) 1738 return; 1739 1740 nft_pipapo_gc_deactivate(net, set, e); 1741 pipapo_drop(m, rulemap); 1742 nft_trans_gc_elem_add(gc, e); 1743 1744 /* And check again current first rule, which is now the 1745 * first we haven't checked. 1746 */ 1747 } else { 1748 first_rule += rules_f0; 1749 } 1750 } 1751 1752 gc = nft_trans_gc_catchall_sync(gc); 1753 if (gc) { 1754 nft_trans_gc_queue_sync_done(gc); 1755 priv->last_gc = jiffies; 1756 } 1757 } 1758 1759 /** 1760 * pipapo_free_fields() - Free per-field tables contained in matching data 1761 * @m: Matching data 1762 */ 1763 static void pipapo_free_fields(struct nft_pipapo_match *m) 1764 { 1765 struct nft_pipapo_field *f; 1766 int i; 1767 1768 nft_pipapo_for_each_field(f, i, m) { 1769 kvfree(f->lt); 1770 kvfree(f->mt); 1771 } 1772 } 1773 1774 static void pipapo_free_match(struct nft_pipapo_match *m) 1775 { 1776 int i; 1777 1778 for_each_possible_cpu(i) 1779 pipapo_free_scratch(m, i); 1780 1781 free_percpu(m->scratch); 1782 pipapo_free_fields(m); 1783 1784 kfree(m); 1785 } 1786 1787 /** 1788 * pipapo_reclaim_match - RCU callback to free fields from old matching data 1789 * @rcu: RCU head 1790 */ 1791 static void pipapo_reclaim_match(struct rcu_head *rcu) 1792 { 1793 struct nft_pipapo_match *m; 1794 1795 m = container_of(rcu, struct nft_pipapo_match, rcu); 1796 pipapo_free_match(m); 1797 } 1798 1799 /** 1800 * nft_pipapo_commit() - Replace lookup data with current working copy 1801 * @set: nftables API set representation 1802 * 1803 * While at it, check if we should perform garbage collection on the working 1804 * copy before committing it for lookup, and don't replace the table if the 1805 * working copy doesn't have pending changes. 1806 * 1807 * We also need to create a new working copy for subsequent insertions and 1808 * deletions. 1809 */ 1810 static void nft_pipapo_commit(struct nft_set *set) 1811 { 1812 struct nft_pipapo *priv = nft_set_priv(set); 1813 struct nft_pipapo_match *old; 1814 1815 if (!priv->clone) 1816 return; 1817 1818 if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set))) 1819 pipapo_gc(set, priv->clone); 1820 1821 old = rcu_replace_pointer(priv->match, priv->clone, 1822 nft_pipapo_transaction_mutex_held(set)); 1823 priv->clone = NULL; 1824 1825 if (old) 1826 call_rcu(&old->rcu, pipapo_reclaim_match); 1827 } 1828 1829 static void nft_pipapo_abort(const struct nft_set *set) 1830 { 1831 struct nft_pipapo *priv = nft_set_priv(set); 1832 1833 if (!priv->clone) 1834 return; 1835 pipapo_free_match(priv->clone); 1836 priv->clone = NULL; 1837 } 1838 1839 /** 1840 * nft_pipapo_activate() - Mark element reference as active given key, commit 1841 * @net: Network namespace 1842 * @set: nftables API set representation 1843 * @elem_priv: nftables API element representation containing key data 1844 * 1845 * On insertion, elements are added to a copy of the matching data currently 1846 * in use for lookups, and not directly inserted into current lookup data. Both 1847 * nft_pipapo_insert() and nft_pipapo_activate() are called once for each 1848 * element, hence we can't purpose either one as a real commit operation. 1849 */ 1850 static void nft_pipapo_activate(const struct net *net, 1851 const struct nft_set *set, 1852 struct nft_elem_priv *elem_priv) 1853 { 1854 struct nft_pipapo_elem *e = nft_elem_priv_cast(elem_priv); 1855 1856 nft_clear(net, &e->ext); 1857 } 1858 1859 /** 1860 * nft_pipapo_deactivate() - Search for element and make it inactive 1861 * @net: Network namespace 1862 * @set: nftables API set representation 1863 * @elem: nftables API element representation containing key data 1864 * 1865 * Return: deactivated element if found, NULL otherwise. 1866 */ 1867 static struct nft_elem_priv * 1868 nft_pipapo_deactivate(const struct net *net, const struct nft_set *set, 1869 const struct nft_set_elem *elem) 1870 { 1871 struct nft_pipapo_match *m = pipapo_maybe_clone(set); 1872 struct nft_pipapo_elem *e; 1873 1874 /* removal must occur on priv->clone, if we are low on memory 1875 * we have no choice and must fail the removal request. 1876 */ 1877 if (!m) 1878 return NULL; 1879 1880 e = pipapo_get(net, set, m, (const u8 *)elem->key.val.data, 1881 nft_genmask_next(net), nft_net_tstamp(net), GFP_KERNEL); 1882 if (IS_ERR(e)) 1883 return NULL; 1884 1885 nft_set_elem_change_active(net, set, &e->ext); 1886 1887 return &e->priv; 1888 } 1889 1890 /** 1891 * nft_pipapo_flush() - make element inactive 1892 * @net: Network namespace 1893 * @set: nftables API set representation 1894 * @elem_priv: nftables API element representation containing key data 1895 * 1896 * This is functionally the same as nft_pipapo_deactivate(), with a slightly 1897 * different interface, and it's also called once for each element in a set 1898 * being flushed, so we can't implement, strictly speaking, a flush operation, 1899 * which would otherwise be as simple as allocating an empty copy of the 1900 * matching data. 1901 * 1902 * Note that we could in theory do that, mark the set as flushed, and ignore 1903 * subsequent calls, but we would leak all the elements after the first one, 1904 * because they wouldn't then be freed as result of API calls. 1905 * 1906 * Return: true if element was found and deactivated. 1907 */ 1908 static void nft_pipapo_flush(const struct net *net, const struct nft_set *set, 1909 struct nft_elem_priv *elem_priv) 1910 { 1911 struct nft_pipapo_elem *e = nft_elem_priv_cast(elem_priv); 1912 1913 nft_set_elem_change_active(net, set, &e->ext); 1914 } 1915 1916 /** 1917 * pipapo_get_boundaries() - Get byte interval for associated rules 1918 * @f: Field including lookup table 1919 * @first_rule: First rule (lowest index) 1920 * @rule_count: Number of associated rules 1921 * @left: Byte expression for left boundary (start of range) 1922 * @right: Byte expression for right boundary (end of range) 1923 * 1924 * Given the first rule and amount of rules that originated from the same entry, 1925 * build the original range associated with the entry, and calculate the length 1926 * of the originating netmask. 1927 * 1928 * In pictures: 1929 * 1930 * bucket 1931 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1932 * 0 1,2 1933 * 1 1,2 1934 * 2 1,2 1935 * 3 1,2 1936 * 4 1,2 1937 * 5 1 2 1938 * 6 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1939 * 7 1,2 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1940 * 1941 * this is the lookup table corresponding to the IPv4 range 1942 * 192.168.1.0-192.168.2.1, which was expanded to the two composing netmasks, 1943 * rule #1: 192.168.1.0/24, and rule #2: 192.168.2.0/31. 1944 * 1945 * This function fills @left and @right with the byte values of the leftmost 1946 * and rightmost bucket indices for the lowest and highest rule indices, 1947 * respectively. If @first_rule is 1 and @rule_count is 2, we obtain, in 1948 * nibbles: 1949 * left: < 12, 0, 10, 8, 0, 1, 0, 0 > 1950 * right: < 12, 0, 10, 8, 0, 2, 2, 1 > 1951 * corresponding to bytes: 1952 * left: < 192, 168, 1, 0 > 1953 * right: < 192, 168, 2, 1 > 1954 * with mask length irrelevant here, unused on return, as the range is already 1955 * defined by its start and end points. The mask length is relevant for a single 1956 * ranged entry instead: if @first_rule is 1 and @rule_count is 1, we ignore 1957 * rule 2 above: @left becomes < 192, 168, 1, 0 >, @right becomes 1958 * < 192, 168, 1, 255 >, and the mask length, calculated from the distances 1959 * between leftmost and rightmost bucket indices for each group, would be 24. 1960 * 1961 * Return: mask length, in bits. 1962 */ 1963 static int pipapo_get_boundaries(struct nft_pipapo_field *f, int first_rule, 1964 int rule_count, u8 *left, u8 *right) 1965 { 1966 int g, mask_len = 0, bit_offset = 0; 1967 u8 *l = left, *r = right; 1968 1969 for (g = 0; g < f->groups; g++) { 1970 int b, x0, x1; 1971 1972 x0 = -1; 1973 x1 = -1; 1974 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) { 1975 unsigned long *pos; 1976 1977 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + 1978 (g * NFT_PIPAPO_BUCKETS(f->bb) + b) * f->bsize; 1979 if (test_bit(first_rule, pos) && x0 == -1) 1980 x0 = b; 1981 if (test_bit(first_rule + rule_count - 1, pos)) 1982 x1 = b; 1983 } 1984 1985 *l |= x0 << (BITS_PER_BYTE - f->bb - bit_offset); 1986 *r |= x1 << (BITS_PER_BYTE - f->bb - bit_offset); 1987 1988 bit_offset += f->bb; 1989 if (bit_offset >= BITS_PER_BYTE) { 1990 bit_offset %= BITS_PER_BYTE; 1991 l++; 1992 r++; 1993 } 1994 1995 if (x1 - x0 == 0) 1996 mask_len += 4; 1997 else if (x1 - x0 == 1) 1998 mask_len += 3; 1999 else if (x1 - x0 == 3) 2000 mask_len += 2; 2001 else if (x1 - x0 == 7) 2002 mask_len += 1; 2003 } 2004 2005 return mask_len; 2006 } 2007 2008 /** 2009 * pipapo_match_field() - Match rules against byte ranges 2010 * @f: Field including the lookup table 2011 * @first_rule: First of associated rules originating from same entry 2012 * @rule_count: Amount of associated rules 2013 * @start: Start of range to be matched 2014 * @end: End of range to be matched 2015 * 2016 * Return: true on match, false otherwise. 2017 */ 2018 static bool pipapo_match_field(struct nft_pipapo_field *f, 2019 int first_rule, int rule_count, 2020 const u8 *start, const u8 *end) 2021 { 2022 u8 right[NFT_PIPAPO_MAX_BYTES] = { 0 }; 2023 u8 left[NFT_PIPAPO_MAX_BYTES] = { 0 }; 2024 2025 pipapo_get_boundaries(f, first_rule, rule_count, left, right); 2026 2027 return !memcmp(start, left, 2028 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) && 2029 !memcmp(end, right, f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)); 2030 } 2031 2032 /** 2033 * nft_pipapo_remove() - Remove element given key, commit 2034 * @net: Network namespace 2035 * @set: nftables API set representation 2036 * @elem_priv: nftables API element representation containing key data 2037 * 2038 * Similarly to nft_pipapo_activate(), this is used as commit operation by the 2039 * API, but it's called once per element in the pending transaction, so we can't 2040 * implement this as a single commit operation. Closest we can get is to remove 2041 * the matched element here, if any, and commit the updated matching data. 2042 */ 2043 static void nft_pipapo_remove(const struct net *net, const struct nft_set *set, 2044 struct nft_elem_priv *elem_priv) 2045 { 2046 struct nft_pipapo *priv = nft_set_priv(set); 2047 struct nft_pipapo_match *m = priv->clone; 2048 unsigned int rules_f0, first_rule = 0; 2049 struct nft_pipapo_elem *e; 2050 const u8 *data; 2051 2052 e = nft_elem_priv_cast(elem_priv); 2053 data = (const u8 *)nft_set_ext_key(&e->ext); 2054 2055 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { 2056 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 2057 const u8 *match_start, *match_end; 2058 struct nft_pipapo_field *f; 2059 int i, start, rules_fx; 2060 2061 match_start = data; 2062 2063 if (nft_set_ext_exists(&e->ext, NFT_SET_EXT_KEY_END)) 2064 match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; 2065 else 2066 match_end = data; 2067 2068 start = first_rule; 2069 rules_fx = rules_f0; 2070 2071 nft_pipapo_for_each_field(f, i, m) { 2072 bool last = i == m->field_count - 1; 2073 2074 if (!pipapo_match_field(f, start, rules_fx, 2075 match_start, match_end)) 2076 break; 2077 2078 rulemap[i].to = start; 2079 rulemap[i].n = rules_fx; 2080 2081 rules_fx = f->mt[start].n; 2082 start = f->mt[start].to; 2083 2084 match_start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 2085 match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 2086 2087 if (last && f->mt[rulemap[i].to].e == e) { 2088 pipapo_drop(m, rulemap); 2089 return; 2090 } 2091 } 2092 2093 first_rule += rules_f0; 2094 } 2095 2096 WARN_ON_ONCE(1); /* elem_priv not found */ 2097 } 2098 2099 /** 2100 * nft_pipapo_do_walk() - Walk over elements in m 2101 * @ctx: nftables API context 2102 * @set: nftables API set representation 2103 * @m: matching data pointing to key mapping array 2104 * @iter: Iterator 2105 * 2106 * As elements are referenced in the mapping array for the last field, directly 2107 * scan that array: there's no need to follow rule mappings from the first 2108 * field. @m is protected either by RCU read lock or by transaction mutex. 2109 */ 2110 static void nft_pipapo_do_walk(const struct nft_ctx *ctx, struct nft_set *set, 2111 const struct nft_pipapo_match *m, 2112 struct nft_set_iter *iter) 2113 { 2114 const struct nft_pipapo_field *f; 2115 unsigned int i, r; 2116 2117 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) 2118 ; 2119 2120 for (r = 0; r < f->rules; r++) { 2121 struct nft_pipapo_elem *e; 2122 2123 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e) 2124 continue; 2125 2126 if (iter->count < iter->skip) 2127 goto cont; 2128 2129 e = f->mt[r].e; 2130 2131 iter->err = iter->fn(ctx, set, iter, &e->priv); 2132 if (iter->err < 0) 2133 return; 2134 2135 cont: 2136 iter->count++; 2137 } 2138 } 2139 2140 /** 2141 * nft_pipapo_walk() - Walk over elements 2142 * @ctx: nftables API context 2143 * @set: nftables API set representation 2144 * @iter: Iterator 2145 * 2146 * Test if destructive action is needed or not, clone active backend if needed 2147 * and call the real function to work on the data. 2148 */ 2149 static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, 2150 struct nft_set_iter *iter) 2151 { 2152 struct nft_pipapo *priv = nft_set_priv(set); 2153 const struct nft_pipapo_match *m; 2154 2155 switch (iter->type) { 2156 case NFT_ITER_UPDATE: 2157 m = pipapo_maybe_clone(set); 2158 if (!m) { 2159 iter->err = -ENOMEM; 2160 return; 2161 } 2162 2163 nft_pipapo_do_walk(ctx, set, m, iter); 2164 break; 2165 case NFT_ITER_READ: 2166 rcu_read_lock(); 2167 m = rcu_dereference(priv->match); 2168 nft_pipapo_do_walk(ctx, set, m, iter); 2169 rcu_read_unlock(); 2170 break; 2171 default: 2172 iter->err = -EINVAL; 2173 WARN_ON_ONCE(1); 2174 break; 2175 } 2176 } 2177 2178 /** 2179 * nft_pipapo_privsize() - Return the size of private data for the set 2180 * @nla: netlink attributes, ignored as size doesn't depend on them 2181 * @desc: Set description, ignored as size doesn't depend on it 2182 * 2183 * Return: size of private data for this set implementation, in bytes 2184 */ 2185 static u64 nft_pipapo_privsize(const struct nlattr * const nla[], 2186 const struct nft_set_desc *desc) 2187 { 2188 return sizeof(struct nft_pipapo); 2189 } 2190 2191 /** 2192 * nft_pipapo_estimate() - Set size, space and lookup complexity 2193 * @desc: Set description, element count and field description used 2194 * @features: Flags: NFT_SET_INTERVAL needs to be there 2195 * @est: Storage for estimation data 2196 * 2197 * Return: true if set description is compatible, false otherwise 2198 */ 2199 static bool nft_pipapo_estimate(const struct nft_set_desc *desc, u32 features, 2200 struct nft_set_estimate *est) 2201 { 2202 if (!(features & NFT_SET_INTERVAL) || 2203 desc->field_count < NFT_PIPAPO_MIN_FIELDS) 2204 return false; 2205 2206 est->size = pipapo_estimate_size(desc); 2207 if (!est->size) 2208 return false; 2209 2210 est->lookup = NFT_SET_CLASS_O_LOG_N; 2211 2212 est->space = NFT_SET_CLASS_O_N; 2213 2214 return true; 2215 } 2216 2217 /** 2218 * nft_pipapo_init() - Initialise data for a set instance 2219 * @set: nftables API set representation 2220 * @desc: Set description 2221 * @nla: netlink attributes 2222 * 2223 * Validate number and size of fields passed as NFTA_SET_DESC_CONCAT netlink 2224 * attributes, initialise internal set parameters, current instance of matching 2225 * data and a copy for subsequent insertions. 2226 * 2227 * Return: 0 on success, negative error code on failure. 2228 */ 2229 static int nft_pipapo_init(const struct nft_set *set, 2230 const struct nft_set_desc *desc, 2231 const struct nlattr * const nla[]) 2232 { 2233 struct nft_pipapo *priv = nft_set_priv(set); 2234 struct nft_pipapo_match *m; 2235 struct nft_pipapo_field *f; 2236 int err, i, field_count; 2237 2238 BUILD_BUG_ON(offsetof(struct nft_pipapo_elem, priv) != 0); 2239 2240 field_count = desc->field_count ? : 1; 2241 2242 BUILD_BUG_ON(NFT_PIPAPO_MAX_FIELDS > 255); 2243 BUILD_BUG_ON(NFT_PIPAPO_MAX_FIELDS != NFT_REG32_COUNT); 2244 2245 if (field_count > NFT_PIPAPO_MAX_FIELDS) 2246 return -EINVAL; 2247 2248 m = kmalloc(struct_size(m, f, field_count), GFP_KERNEL); 2249 if (!m) 2250 return -ENOMEM; 2251 2252 m->field_count = field_count; 2253 m->bsize_max = 0; 2254 2255 m->scratch = alloc_percpu(struct nft_pipapo_scratch *); 2256 if (!m->scratch) { 2257 err = -ENOMEM; 2258 goto out_scratch; 2259 } 2260 for_each_possible_cpu(i) 2261 *per_cpu_ptr(m->scratch, i) = NULL; 2262 2263 rcu_head_init(&m->rcu); 2264 2265 nft_pipapo_for_each_field(f, i, m) { 2266 unsigned int len = desc->field_len[i] ? : set->klen; 2267 2268 /* f->groups is u8 */ 2269 BUILD_BUG_ON((NFT_PIPAPO_MAX_BYTES * 2270 BITS_PER_BYTE / NFT_PIPAPO_GROUP_BITS_LARGE_SET) >= 256); 2271 2272 f->bb = NFT_PIPAPO_GROUP_BITS_INIT; 2273 f->groups = len * NFT_PIPAPO_GROUPS_PER_BYTE(f); 2274 2275 priv->width += round_up(len, sizeof(u32)); 2276 2277 f->bsize = 0; 2278 f->rules = 0; 2279 f->rules_alloc = 0; 2280 f->lt = NULL; 2281 f->mt = NULL; 2282 } 2283 2284 rcu_assign_pointer(priv->match, m); 2285 2286 return 0; 2287 2288 out_scratch: 2289 kfree(m); 2290 2291 return err; 2292 } 2293 2294 /** 2295 * nft_set_pipapo_match_destroy() - Destroy elements from key mapping array 2296 * @ctx: context 2297 * @set: nftables API set representation 2298 * @m: matching data pointing to key mapping array 2299 */ 2300 static void nft_set_pipapo_match_destroy(const struct nft_ctx *ctx, 2301 const struct nft_set *set, 2302 struct nft_pipapo_match *m) 2303 { 2304 struct nft_pipapo_field *f; 2305 unsigned int i, r; 2306 2307 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) 2308 ; 2309 2310 for (r = 0; r < f->rules; r++) { 2311 struct nft_pipapo_elem *e; 2312 2313 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e) 2314 continue; 2315 2316 e = f->mt[r].e; 2317 2318 nf_tables_set_elem_destroy(ctx, set, &e->priv); 2319 } 2320 } 2321 2322 /** 2323 * nft_pipapo_destroy() - Free private data for set and all committed elements 2324 * @ctx: context 2325 * @set: nftables API set representation 2326 */ 2327 static void nft_pipapo_destroy(const struct nft_ctx *ctx, 2328 const struct nft_set *set) 2329 { 2330 struct nft_pipapo *priv = nft_set_priv(set); 2331 struct nft_pipapo_match *m; 2332 2333 m = rcu_dereference_protected(priv->match, true); 2334 2335 if (priv->clone) { 2336 nft_set_pipapo_match_destroy(ctx, set, priv->clone); 2337 pipapo_free_match(priv->clone); 2338 priv->clone = NULL; 2339 } else { 2340 nft_set_pipapo_match_destroy(ctx, set, m); 2341 } 2342 2343 pipapo_free_match(m); 2344 } 2345 2346 /** 2347 * nft_pipapo_gc_init() - Initialise garbage collection 2348 * @set: nftables API set representation 2349 * 2350 * Instead of actually setting up a periodic work for garbage collection, as 2351 * this operation requires a swap of matching data with the working copy, we'll 2352 * do that opportunistically with other commit operations if the interval is 2353 * elapsed, so we just need to set the current jiffies timestamp here. 2354 */ 2355 static void nft_pipapo_gc_init(const struct nft_set *set) 2356 { 2357 struct nft_pipapo *priv = nft_set_priv(set); 2358 2359 priv->last_gc = jiffies; 2360 } 2361 2362 const struct nft_set_type nft_set_pipapo_type = { 2363 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | 2364 NFT_SET_TIMEOUT, 2365 .ops = { 2366 .lookup = nft_pipapo_lookup, 2367 .insert = nft_pipapo_insert, 2368 .activate = nft_pipapo_activate, 2369 .deactivate = nft_pipapo_deactivate, 2370 .flush = nft_pipapo_flush, 2371 .remove = nft_pipapo_remove, 2372 .walk = nft_pipapo_walk, 2373 .get = nft_pipapo_get, 2374 .privsize = nft_pipapo_privsize, 2375 .estimate = nft_pipapo_estimate, 2376 .init = nft_pipapo_init, 2377 .destroy = nft_pipapo_destroy, 2378 .gc_init = nft_pipapo_gc_init, 2379 .commit = nft_pipapo_commit, 2380 .abort = nft_pipapo_abort, 2381 .elemsize = offsetof(struct nft_pipapo_elem, ext), 2382 }, 2383 }; 2384 2385 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML) 2386 const struct nft_set_type nft_set_pipapo_avx2_type = { 2387 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | 2388 NFT_SET_TIMEOUT, 2389 .ops = { 2390 .lookup = nft_pipapo_avx2_lookup, 2391 .insert = nft_pipapo_insert, 2392 .activate = nft_pipapo_activate, 2393 .deactivate = nft_pipapo_deactivate, 2394 .flush = nft_pipapo_flush, 2395 .remove = nft_pipapo_remove, 2396 .walk = nft_pipapo_walk, 2397 .get = nft_pipapo_get, 2398 .privsize = nft_pipapo_privsize, 2399 .estimate = nft_pipapo_avx2_estimate, 2400 .init = nft_pipapo_init, 2401 .destroy = nft_pipapo_destroy, 2402 .gc_init = nft_pipapo_gc_init, 2403 .commit = nft_pipapo_commit, 2404 .abort = nft_pipapo_abort, 2405 .elemsize = offsetof(struct nft_pipapo_elem, ext), 2406 }, 2407 }; 2408 #endif 2409
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.