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 /* Current working bitmap index, toggled between field matches */ 346 static DEFINE_PER_CPU(bool, nft_pipapo_scratch_index); 347 348 /** 349 * pipapo_refill() - For each set bit, set bits from selected mapping table item 350 * @map: Bitmap to be scanned for set bits 351 * @len: Length of bitmap in longs 352 * @rules: Number of rules in field 353 * @dst: Destination bitmap 354 * @mt: Mapping table containing bit set specifiers 355 * @match_only: Find a single bit and return, don't fill 356 * 357 * Iteration over set bits with __builtin_ctzl(): Daniel Lemire, public domain. 358 * 359 * For each bit set in map, select the bucket from mapping table with index 360 * corresponding to the position of the bit set. Use start bit and amount of 361 * bits specified in bucket to fill region in dst. 362 * 363 * Return: -1 on no match, bit position on 'match_only', 0 otherwise. 364 */ 365 int pipapo_refill(unsigned long *map, int len, int rules, unsigned long *dst, 366 union nft_pipapo_map_bucket *mt, bool match_only) 367 { 368 unsigned long bitset; 369 int k, ret = -1; 370 371 for (k = 0; k < len; k++) { 372 bitset = map[k]; 373 while (bitset) { 374 unsigned long t = bitset & -bitset; 375 int r = __builtin_ctzl(bitset); 376 int i = k * BITS_PER_LONG + r; 377 378 if (unlikely(i >= rules)) { 379 map[k] = 0; 380 return -1; 381 } 382 383 if (match_only) { 384 bitmap_clear(map, i, 1); 385 return i; 386 } 387 388 ret = 0; 389 390 bitmap_set(dst, mt[i].to, mt[i].n); 391 392 bitset ^= t; 393 } 394 map[k] = 0; 395 } 396 397 return ret; 398 } 399 400 /** 401 * nft_pipapo_lookup() - Lookup function 402 * @net: Network namespace 403 * @set: nftables API set representation 404 * @key: nftables API element representation containing key data 405 * @ext: nftables API extension pointer, filled with matching reference 406 * 407 * For more details, see DOC: Theory of Operation. 408 * 409 * Return: true on match, false otherwise. 410 */ 411 bool nft_pipapo_lookup(const struct net *net, const struct nft_set *set, 412 const u32 *key, const struct nft_set_ext **ext) 413 { 414 struct nft_pipapo *priv = nft_set_priv(set); 415 unsigned long *res_map, *fill_map; 416 u8 genmask = nft_genmask_cur(net); 417 const u8 *rp = (const u8 *)key; 418 struct nft_pipapo_match *m; 419 struct nft_pipapo_field *f; 420 bool map_index; 421 int i; 422 423 local_bh_disable(); 424 425 map_index = raw_cpu_read(nft_pipapo_scratch_index); 426 427 m = rcu_dereference(priv->match); 428 429 if (unlikely(!m || !*raw_cpu_ptr(m->scratch))) 430 goto out; 431 432 res_map = *raw_cpu_ptr(m->scratch) + (map_index ? m->bsize_max : 0); 433 fill_map = *raw_cpu_ptr(m->scratch) + (map_index ? 0 : m->bsize_max); 434 435 memset(res_map, 0xff, m->bsize_max * sizeof(*res_map)); 436 437 nft_pipapo_for_each_field(f, i, m) { 438 bool last = i == m->field_count - 1; 439 int b; 440 441 /* For each bit group: select lookup table bucket depending on 442 * packet bytes value, then AND bucket value 443 */ 444 if (likely(f->bb == 8)) 445 pipapo_and_field_buckets_8bit(f, res_map, rp); 446 else 447 pipapo_and_field_buckets_4bit(f, res_map, rp); 448 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4; 449 450 rp += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f); 451 452 /* Now populate the bitmap for the next field, unless this is 453 * the last field, in which case return the matched 'ext' 454 * pointer if any. 455 * 456 * Now res_map contains the matching bitmap, and fill_map is the 457 * bitmap for the next field. 458 */ 459 next_match: 460 b = pipapo_refill(res_map, f->bsize, f->rules, fill_map, f->mt, 461 last); 462 if (b < 0) { 463 raw_cpu_write(nft_pipapo_scratch_index, map_index); 464 local_bh_enable(); 465 466 return false; 467 } 468 469 if (last) { 470 *ext = &f->mt[b].e->ext; 471 if (unlikely(nft_set_elem_expired(*ext) || 472 !nft_set_elem_active(*ext, genmask))) 473 goto next_match; 474 475 /* Last field: we're just returning the key without 476 * filling the initial bitmap for the next field, so the 477 * current inactive bitmap is clean and can be reused as 478 * *next* bitmap (not initial) for the next packet. 479 */ 480 raw_cpu_write(nft_pipapo_scratch_index, map_index); 481 local_bh_enable(); 482 483 return true; 484 } 485 486 /* Swap bitmap indices: res_map is the initial bitmap for the 487 * next field, and fill_map is guaranteed to be all-zeroes at 488 * this point. 489 */ 490 map_index = !map_index; 491 swap(res_map, fill_map); 492 493 rp += NFT_PIPAPO_GROUPS_PADDING(f); 494 } 495 496 out: 497 local_bh_enable(); 498 return false; 499 } 500 501 /** 502 * pipapo_get() - Get matching element reference given key data 503 * @net: Network namespace 504 * @set: nftables API set representation 505 * @data: Key data to be matched against existing elements 506 * @genmask: If set, check that element is active in given genmask 507 * 508 * This is essentially the same as the lookup function, except that it matches 509 * key data against the uncommitted copy and doesn't use preallocated maps for 510 * bitmap results. 511 * 512 * Return: pointer to &struct nft_pipapo_elem on match, error pointer otherwise. 513 */ 514 static struct nft_pipapo_elem *pipapo_get(const struct net *net, 515 const struct nft_set *set, 516 const u8 *data, u8 genmask) 517 { 518 struct nft_pipapo_elem *ret = ERR_PTR(-ENOENT); 519 struct nft_pipapo *priv = nft_set_priv(set); 520 struct nft_pipapo_match *m = priv->clone; 521 unsigned long *res_map, *fill_map = NULL; 522 struct nft_pipapo_field *f; 523 int i; 524 525 res_map = kmalloc_array(m->bsize_max, sizeof(*res_map), GFP_ATOMIC); 526 if (!res_map) { 527 ret = ERR_PTR(-ENOMEM); 528 goto out; 529 } 530 531 fill_map = kcalloc(m->bsize_max, sizeof(*res_map), GFP_ATOMIC); 532 if (!fill_map) { 533 ret = ERR_PTR(-ENOMEM); 534 goto out; 535 } 536 537 memset(res_map, 0xff, m->bsize_max * sizeof(*res_map)); 538 539 nft_pipapo_for_each_field(f, i, m) { 540 bool last = i == m->field_count - 1; 541 int b; 542 543 /* For each bit group: select lookup table bucket depending on 544 * packet bytes value, then AND bucket value 545 */ 546 if (f->bb == 8) 547 pipapo_and_field_buckets_8bit(f, res_map, data); 548 else if (f->bb == 4) 549 pipapo_and_field_buckets_4bit(f, res_map, data); 550 else 551 BUG(); 552 553 data += f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f); 554 555 /* Now populate the bitmap for the next field, unless this is 556 * the last field, in which case return the matched 'ext' 557 * pointer if any. 558 * 559 * Now res_map contains the matching bitmap, and fill_map is the 560 * bitmap for the next field. 561 */ 562 next_match: 563 b = pipapo_refill(res_map, f->bsize, f->rules, fill_map, f->mt, 564 last); 565 if (b < 0) 566 goto out; 567 568 if (last) { 569 if (nft_set_elem_expired(&f->mt[b].e->ext) || 570 (genmask && 571 !nft_set_elem_active(&f->mt[b].e->ext, genmask))) 572 goto next_match; 573 574 ret = f->mt[b].e; 575 goto out; 576 } 577 578 data += NFT_PIPAPO_GROUPS_PADDING(f); 579 580 /* Swap bitmap indices: fill_map will be the initial bitmap for 581 * the next field (i.e. the new res_map), and res_map is 582 * guaranteed to be all-zeroes at this point, ready to be filled 583 * according to the next mapping table. 584 */ 585 swap(res_map, fill_map); 586 } 587 588 out: 589 kfree(fill_map); 590 kfree(res_map); 591 return ret; 592 } 593 594 /** 595 * nft_pipapo_get() - Get matching element reference given key data 596 * @net: Network namespace 597 * @set: nftables API set representation 598 * @elem: nftables API element representation containing key data 599 * @flags: Unused 600 */ 601 static void *nft_pipapo_get(const struct net *net, const struct nft_set *set, 602 const struct nft_set_elem *elem, unsigned int flags) 603 { 604 return pipapo_get(net, set, (const u8 *)elem->key.val.data, 605 nft_genmask_cur(net)); 606 } 607 608 /** 609 * pipapo_resize() - Resize lookup or mapping table, or both 610 * @f: Field containing lookup and mapping tables 611 * @old_rules: Previous amount of rules in field 612 * @rules: New amount of rules 613 * 614 * Increase, decrease or maintain tables size depending on new amount of rules, 615 * and copy data over. In case the new size is smaller, throw away data for 616 * highest-numbered rules. 617 * 618 * Return: 0 on success, -ENOMEM on allocation failure. 619 */ 620 static int pipapo_resize(struct nft_pipapo_field *f, int old_rules, int rules) 621 { 622 long *new_lt = NULL, *new_p, *old_lt = f->lt, *old_p; 623 union nft_pipapo_map_bucket *new_mt, *old_mt = f->mt; 624 size_t new_bucket_size, copy; 625 int group, bucket; 626 627 new_bucket_size = DIV_ROUND_UP(rules, BITS_PER_LONG); 628 #ifdef NFT_PIPAPO_ALIGN 629 new_bucket_size = roundup(new_bucket_size, 630 NFT_PIPAPO_ALIGN / sizeof(*new_lt)); 631 #endif 632 633 if (new_bucket_size == f->bsize) 634 goto mt; 635 636 if (new_bucket_size > f->bsize) 637 copy = f->bsize; 638 else 639 copy = new_bucket_size; 640 641 new_lt = kvzalloc(f->groups * NFT_PIPAPO_BUCKETS(f->bb) * 642 new_bucket_size * sizeof(*new_lt) + 643 NFT_PIPAPO_ALIGN_HEADROOM, 644 GFP_KERNEL); 645 if (!new_lt) 646 return -ENOMEM; 647 648 new_p = NFT_PIPAPO_LT_ALIGN(new_lt); 649 old_p = NFT_PIPAPO_LT_ALIGN(old_lt); 650 651 for (group = 0; group < f->groups; group++) { 652 for (bucket = 0; bucket < NFT_PIPAPO_BUCKETS(f->bb); bucket++) { 653 memcpy(new_p, old_p, copy * sizeof(*new_p)); 654 new_p += copy; 655 old_p += copy; 656 657 if (new_bucket_size > f->bsize) 658 new_p += new_bucket_size - f->bsize; 659 else 660 old_p += f->bsize - new_bucket_size; 661 } 662 } 663 664 mt: 665 new_mt = kvmalloc(rules * sizeof(*new_mt), GFP_KERNEL); 666 if (!new_mt) { 667 kvfree(new_lt); 668 return -ENOMEM; 669 } 670 671 memcpy(new_mt, f->mt, min(old_rules, rules) * sizeof(*new_mt)); 672 if (rules > old_rules) { 673 memset(new_mt + old_rules, 0, 674 (rules - old_rules) * sizeof(*new_mt)); 675 } 676 677 if (new_lt) { 678 f->bsize = new_bucket_size; 679 NFT_PIPAPO_LT_ASSIGN(f, new_lt); 680 kvfree(old_lt); 681 } 682 683 f->mt = new_mt; 684 kvfree(old_mt); 685 686 return 0; 687 } 688 689 /** 690 * pipapo_bucket_set() - Set rule bit in bucket given group and group value 691 * @f: Field containing lookup table 692 * @rule: Rule index 693 * @group: Group index 694 * @v: Value of bit group 695 */ 696 static void pipapo_bucket_set(struct nft_pipapo_field *f, int rule, int group, 697 int v) 698 { 699 unsigned long *pos; 700 701 pos = NFT_PIPAPO_LT_ALIGN(f->lt); 702 pos += f->bsize * NFT_PIPAPO_BUCKETS(f->bb) * group; 703 pos += f->bsize * v; 704 705 __set_bit(rule, pos); 706 } 707 708 /** 709 * pipapo_lt_4b_to_8b() - Switch lookup table group width from 4 bits to 8 bits 710 * @old_groups: Number of current groups 711 * @bsize: Size of one bucket, in longs 712 * @old_lt: Pointer to the current lookup table 713 * @new_lt: Pointer to the new, pre-allocated lookup table 714 * 715 * Each bucket with index b in the new lookup table, belonging to group g, is 716 * filled with the bit intersection between: 717 * - bucket with index given by the upper 4 bits of b, from group g, and 718 * - bucket with index given by the lower 4 bits of b, from group g + 1 719 * 720 * That is, given buckets from the new lookup table N(x, y) and the old lookup 721 * table O(x, y), with x bucket index, and y group index: 722 * 723 * N(b, g) := O(b / 16, g) & O(b % 16, g + 1) 724 * 725 * This ensures equivalence of the matching results on lookup. Two examples in 726 * pictures: 727 * 728 * bucket 729 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 ... 254 255 730 * 0 ^ 731 * 1 | ^ 732 * ... ( & ) | 733 * / \ | 734 * / \ .-( & )-. 735 * / bucket \ | | 736 * group 0 / 1 2 3 \ 4 5 6 7 8 9 10 11 12 13 |14 15 | 737 * 0 / \ | | 738 * 1 \ | | 739 * 2 | --' 740 * 3 '- 741 * ... 742 */ 743 static void pipapo_lt_4b_to_8b(int old_groups, int bsize, 744 unsigned long *old_lt, unsigned long *new_lt) 745 { 746 int g, b, i; 747 748 for (g = 0; g < old_groups / 2; g++) { 749 int src_g0 = g * 2, src_g1 = g * 2 + 1; 750 751 for (b = 0; b < NFT_PIPAPO_BUCKETS(8); b++) { 752 int src_b0 = b / NFT_PIPAPO_BUCKETS(4); 753 int src_b1 = b % NFT_PIPAPO_BUCKETS(4); 754 int src_i0 = src_g0 * NFT_PIPAPO_BUCKETS(4) + src_b0; 755 int src_i1 = src_g1 * NFT_PIPAPO_BUCKETS(4) + src_b1; 756 757 for (i = 0; i < bsize; i++) { 758 *new_lt = old_lt[src_i0 * bsize + i] & 759 old_lt[src_i1 * bsize + i]; 760 new_lt++; 761 } 762 } 763 } 764 } 765 766 /** 767 * pipapo_lt_8b_to_4b() - Switch lookup table group width from 8 bits to 4 bits 768 * @old_groups: Number of current groups 769 * @bsize: Size of one bucket, in longs 770 * @old_lt: Pointer to the current lookup table 771 * @new_lt: Pointer to the new, pre-allocated lookup table 772 * 773 * Each bucket with index b in the new lookup table, belonging to group g, is 774 * filled with the bit union of: 775 * - all the buckets with index such that the upper four bits of the lower byte 776 * equal b, from group g, with g odd 777 * - all the buckets with index such that the lower four bits equal b, from 778 * group g, with g even 779 * 780 * That is, given buckets from the new lookup table N(x, y) and the old lookup 781 * table O(x, y), with x bucket index, and y group index: 782 * 783 * - with g odd: N(b, g) := U(O(x, g) for each x : x = (b & 0xf0) >> 4) 784 * - with g even: N(b, g) := U(O(x, g) for each x : x = b & 0x0f) 785 * 786 * where U() denotes the arbitrary union operation (binary OR of n terms). This 787 * ensures equivalence of the matching results on lookup. 788 */ 789 static void pipapo_lt_8b_to_4b(int old_groups, int bsize, 790 unsigned long *old_lt, unsigned long *new_lt) 791 { 792 int g, b, bsrc, i; 793 794 memset(new_lt, 0, old_groups * 2 * NFT_PIPAPO_BUCKETS(4) * bsize * 795 sizeof(unsigned long)); 796 797 for (g = 0; g < old_groups * 2; g += 2) { 798 int src_g = g / 2; 799 800 for (b = 0; b < NFT_PIPAPO_BUCKETS(4); b++) { 801 for (bsrc = NFT_PIPAPO_BUCKETS(8) * src_g; 802 bsrc < NFT_PIPAPO_BUCKETS(8) * (src_g + 1); 803 bsrc++) { 804 if (((bsrc & 0xf0) >> 4) != b) 805 continue; 806 807 for (i = 0; i < bsize; i++) 808 new_lt[i] |= old_lt[bsrc * bsize + i]; 809 } 810 811 new_lt += bsize; 812 } 813 814 for (b = 0; b < NFT_PIPAPO_BUCKETS(4); b++) { 815 for (bsrc = NFT_PIPAPO_BUCKETS(8) * src_g; 816 bsrc < NFT_PIPAPO_BUCKETS(8) * (src_g + 1); 817 bsrc++) { 818 if ((bsrc & 0x0f) != b) 819 continue; 820 821 for (i = 0; i < bsize; i++) 822 new_lt[i] |= old_lt[bsrc * bsize + i]; 823 } 824 825 new_lt += bsize; 826 } 827 } 828 } 829 830 /** 831 * pipapo_lt_bits_adjust() - Adjust group size for lookup table if needed 832 * @f: Field containing lookup table 833 */ 834 static void pipapo_lt_bits_adjust(struct nft_pipapo_field *f) 835 { 836 unsigned long *new_lt; 837 int groups, bb; 838 size_t lt_size; 839 840 lt_size = f->groups * NFT_PIPAPO_BUCKETS(f->bb) * f->bsize * 841 sizeof(*f->lt); 842 843 if (f->bb == NFT_PIPAPO_GROUP_BITS_SMALL_SET && 844 lt_size > NFT_PIPAPO_LT_SIZE_HIGH) { 845 groups = f->groups * 2; 846 bb = NFT_PIPAPO_GROUP_BITS_LARGE_SET; 847 848 lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize * 849 sizeof(*f->lt); 850 } else if (f->bb == NFT_PIPAPO_GROUP_BITS_LARGE_SET && 851 lt_size < NFT_PIPAPO_LT_SIZE_LOW) { 852 groups = f->groups / 2; 853 bb = NFT_PIPAPO_GROUP_BITS_SMALL_SET; 854 855 lt_size = groups * NFT_PIPAPO_BUCKETS(bb) * f->bsize * 856 sizeof(*f->lt); 857 858 /* Don't increase group width if the resulting lookup table size 859 * would exceed the upper size threshold for a "small" set. 860 */ 861 if (lt_size > NFT_PIPAPO_LT_SIZE_HIGH) 862 return; 863 } else { 864 return; 865 } 866 867 new_lt = kvzalloc(lt_size + NFT_PIPAPO_ALIGN_HEADROOM, GFP_KERNEL); 868 if (!new_lt) 869 return; 870 871 NFT_PIPAPO_GROUP_BITS_ARE_8_OR_4; 872 if (f->bb == 4 && bb == 8) { 873 pipapo_lt_4b_to_8b(f->groups, f->bsize, 874 NFT_PIPAPO_LT_ALIGN(f->lt), 875 NFT_PIPAPO_LT_ALIGN(new_lt)); 876 } else if (f->bb == 8 && bb == 4) { 877 pipapo_lt_8b_to_4b(f->groups, f->bsize, 878 NFT_PIPAPO_LT_ALIGN(f->lt), 879 NFT_PIPAPO_LT_ALIGN(new_lt)); 880 } else { 881 BUG(); 882 } 883 884 f->groups = groups; 885 f->bb = bb; 886 kvfree(f->lt); 887 NFT_PIPAPO_LT_ASSIGN(f, new_lt); 888 } 889 890 /** 891 * pipapo_insert() - Insert new rule in field given input key and mask length 892 * @f: Field containing lookup table 893 * @k: Input key for classification, without nftables padding 894 * @mask_bits: Length of mask; matches field length for non-ranged entry 895 * 896 * Insert a new rule reference in lookup buckets corresponding to k and 897 * mask_bits. 898 * 899 * Return: 1 on success (one rule inserted), negative error code on failure. 900 */ 901 static int pipapo_insert(struct nft_pipapo_field *f, const uint8_t *k, 902 int mask_bits) 903 { 904 int rule = f->rules++, group, ret, bit_offset = 0; 905 906 ret = pipapo_resize(f, f->rules - 1, f->rules); 907 if (ret) 908 return ret; 909 910 for (group = 0; group < f->groups; group++) { 911 int i, v; 912 u8 mask; 913 914 v = k[group / (BITS_PER_BYTE / f->bb)]; 915 v &= GENMASK(BITS_PER_BYTE - bit_offset - 1, 0); 916 v >>= (BITS_PER_BYTE - bit_offset) - f->bb; 917 918 bit_offset += f->bb; 919 bit_offset %= BITS_PER_BYTE; 920 921 if (mask_bits >= (group + 1) * f->bb) { 922 /* Not masked */ 923 pipapo_bucket_set(f, rule, group, v); 924 } else if (mask_bits <= group * f->bb) { 925 /* Completely masked */ 926 for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++) 927 pipapo_bucket_set(f, rule, group, i); 928 } else { 929 /* The mask limit falls on this group */ 930 mask = GENMASK(f->bb - 1, 0); 931 mask >>= mask_bits - group * f->bb; 932 for (i = 0; i < NFT_PIPAPO_BUCKETS(f->bb); i++) { 933 if ((i & ~mask) == (v & ~mask)) 934 pipapo_bucket_set(f, rule, group, i); 935 } 936 } 937 } 938 939 pipapo_lt_bits_adjust(f); 940 941 return 1; 942 } 943 944 /** 945 * pipapo_step_diff() - Check if setting @step bit in netmask would change it 946 * @base: Mask we are expanding 947 * @step: Step bit for given expansion step 948 * @len: Total length of mask space (set and unset bits), bytes 949 * 950 * Convenience function for mask expansion. 951 * 952 * Return: true if step bit changes mask (i.e. isn't set), false otherwise. 953 */ 954 static bool pipapo_step_diff(u8 *base, int step, int len) 955 { 956 /* Network order, byte-addressed */ 957 #ifdef __BIG_ENDIAN__ 958 return !(BIT(step % BITS_PER_BYTE) & base[step / BITS_PER_BYTE]); 959 #else 960 return !(BIT(step % BITS_PER_BYTE) & 961 base[len - 1 - step / BITS_PER_BYTE]); 962 #endif 963 } 964 965 /** 966 * pipapo_step_after_end() - Check if mask exceeds range end with given step 967 * @base: Mask we are expanding 968 * @end: End of range 969 * @step: Step bit for given expansion step, highest bit to be set 970 * @len: Total length of mask space (set and unset bits), bytes 971 * 972 * Convenience function for mask expansion. 973 * 974 * Return: true if mask exceeds range setting step bits, false otherwise. 975 */ 976 static bool pipapo_step_after_end(const u8 *base, const u8 *end, int step, 977 int len) 978 { 979 u8 tmp[NFT_PIPAPO_MAX_BYTES]; 980 int i; 981 982 memcpy(tmp, base, len); 983 984 /* Network order, byte-addressed */ 985 for (i = 0; i <= step; i++) 986 #ifdef __BIG_ENDIAN__ 987 tmp[i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE); 988 #else 989 tmp[len - 1 - i / BITS_PER_BYTE] |= BIT(i % BITS_PER_BYTE); 990 #endif 991 992 return memcmp(tmp, end, len) > 0; 993 } 994 995 /** 996 * pipapo_base_sum() - Sum step bit to given len-sized netmask base with carry 997 * @base: Netmask base 998 * @step: Step bit to sum 999 * @len: Netmask length, bytes 1000 */ 1001 static void pipapo_base_sum(u8 *base, int step, int len) 1002 { 1003 bool carry = false; 1004 int i; 1005 1006 /* Network order, byte-addressed */ 1007 #ifdef __BIG_ENDIAN__ 1008 for (i = step / BITS_PER_BYTE; i < len; i++) { 1009 #else 1010 for (i = len - 1 - step / BITS_PER_BYTE; i >= 0; i--) { 1011 #endif 1012 if (carry) 1013 base[i]++; 1014 else 1015 base[i] += 1 << (step % BITS_PER_BYTE); 1016 1017 if (base[i]) 1018 break; 1019 1020 carry = true; 1021 } 1022 } 1023 1024 /** 1025 * pipapo_expand() - Expand to composing netmasks, insert into lookup table 1026 * @f: Field containing lookup table 1027 * @start: Start of range 1028 * @end: End of range 1029 * @len: Length of value in bits 1030 * 1031 * Expand range to composing netmasks and insert corresponding rule references 1032 * in lookup buckets. 1033 * 1034 * Return: number of inserted rules on success, negative error code on failure. 1035 */ 1036 static int pipapo_expand(struct nft_pipapo_field *f, 1037 const u8 *start, const u8 *end, int len) 1038 { 1039 int step, masks = 0, bytes = DIV_ROUND_UP(len, BITS_PER_BYTE); 1040 u8 base[NFT_PIPAPO_MAX_BYTES]; 1041 1042 memcpy(base, start, bytes); 1043 while (memcmp(base, end, bytes) <= 0) { 1044 int err; 1045 1046 step = 0; 1047 while (pipapo_step_diff(base, step, bytes)) { 1048 if (pipapo_step_after_end(base, end, step, bytes)) 1049 break; 1050 1051 step++; 1052 if (step >= len) { 1053 if (!masks) { 1054 pipapo_insert(f, base, 0); 1055 masks = 1; 1056 } 1057 goto out; 1058 } 1059 } 1060 1061 err = pipapo_insert(f, base, len - step); 1062 1063 if (err < 0) 1064 return err; 1065 1066 masks++; 1067 pipapo_base_sum(base, step, bytes); 1068 } 1069 out: 1070 return masks; 1071 } 1072 1073 /** 1074 * pipapo_map() - Insert rules in mapping tables, mapping them between fields 1075 * @m: Matching data, including mapping table 1076 * @map: Table of rule maps: array of first rule and amount of rules 1077 * in next field a given rule maps to, for each field 1078 * @e: For last field, nft_set_ext pointer matching rules map to 1079 */ 1080 static void pipapo_map(struct nft_pipapo_match *m, 1081 union nft_pipapo_map_bucket map[NFT_PIPAPO_MAX_FIELDS], 1082 struct nft_pipapo_elem *e) 1083 { 1084 struct nft_pipapo_field *f; 1085 int i, j; 1086 1087 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) { 1088 for (j = 0; j < map[i].n; j++) { 1089 f->mt[map[i].to + j].to = map[i + 1].to; 1090 f->mt[map[i].to + j].n = map[i + 1].n; 1091 } 1092 } 1093 1094 /* Last field: map to ext instead of mapping to next field */ 1095 for (j = 0; j < map[i].n; j++) 1096 f->mt[map[i].to + j].e = e; 1097 } 1098 1099 /** 1100 * pipapo_realloc_scratch() - Reallocate scratch maps for partial match results 1101 * @clone: Copy of matching data with pending insertions and deletions 1102 * @bsize_max: Maximum bucket size, scratch maps cover two buckets 1103 * 1104 * Return: 0 on success, -ENOMEM on failure. 1105 */ 1106 static int pipapo_realloc_scratch(struct nft_pipapo_match *clone, 1107 unsigned long bsize_max) 1108 { 1109 int i; 1110 1111 for_each_possible_cpu(i) { 1112 unsigned long *scratch; 1113 #ifdef NFT_PIPAPO_ALIGN 1114 unsigned long *scratch_aligned; 1115 #endif 1116 1117 scratch = kzalloc_node(bsize_max * sizeof(*scratch) * 2 + 1118 NFT_PIPAPO_ALIGN_HEADROOM, 1119 GFP_KERNEL, cpu_to_node(i)); 1120 if (!scratch) { 1121 /* On failure, there's no need to undo previous 1122 * allocations: this means that some scratch maps have 1123 * a bigger allocated size now (this is only called on 1124 * insertion), but the extra space won't be used by any 1125 * CPU as new elements are not inserted and m->bsize_max 1126 * is not updated. 1127 */ 1128 return -ENOMEM; 1129 } 1130 1131 kfree(*per_cpu_ptr(clone->scratch, i)); 1132 1133 *per_cpu_ptr(clone->scratch, i) = scratch; 1134 1135 #ifdef NFT_PIPAPO_ALIGN 1136 scratch_aligned = NFT_PIPAPO_LT_ALIGN(scratch); 1137 *per_cpu_ptr(clone->scratch_aligned, i) = scratch_aligned; 1138 #endif 1139 } 1140 1141 return 0; 1142 } 1143 1144 /** 1145 * nft_pipapo_insert() - Validate and insert ranged elements 1146 * @net: Network namespace 1147 * @set: nftables API set representation 1148 * @elem: nftables API element representation containing key data 1149 * @ext2: Filled with pointer to &struct nft_set_ext in inserted element 1150 * 1151 * Return: 0 on success, error pointer on failure. 1152 */ 1153 static int nft_pipapo_insert(const struct net *net, const struct nft_set *set, 1154 const struct nft_set_elem *elem, 1155 struct nft_set_ext **ext2) 1156 { 1157 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); 1158 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1159 const u8 *start = (const u8 *)elem->key.val.data, *end; 1160 struct nft_pipapo_elem *e = elem->priv, *dup; 1161 struct nft_pipapo *priv = nft_set_priv(set); 1162 struct nft_pipapo_match *m = priv->clone; 1163 u8 genmask = nft_genmask_next(net); 1164 struct nft_pipapo_field *f; 1165 int i, bsize_max, err = 0; 1166 1167 if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) 1168 end = (const u8 *)nft_set_ext_key_end(ext)->data; 1169 else 1170 end = start; 1171 1172 dup = pipapo_get(net, set, start, genmask); 1173 if (!IS_ERR(dup)) { 1174 /* Check if we already have the same exact entry */ 1175 const struct nft_data *dup_key, *dup_end; 1176 1177 dup_key = nft_set_ext_key(&dup->ext); 1178 if (nft_set_ext_exists(&dup->ext, NFT_SET_EXT_KEY_END)) 1179 dup_end = nft_set_ext_key_end(&dup->ext); 1180 else 1181 dup_end = dup_key; 1182 1183 if (!memcmp(start, dup_key->data, sizeof(*dup_key->data)) && 1184 !memcmp(end, dup_end->data, sizeof(*dup_end->data))) { 1185 *ext2 = &dup->ext; 1186 return -EEXIST; 1187 } 1188 1189 return -ENOTEMPTY; 1190 } 1191 1192 if (PTR_ERR(dup) == -ENOENT) { 1193 /* Look for partially overlapping entries */ 1194 dup = pipapo_get(net, set, end, nft_genmask_next(net)); 1195 } 1196 1197 if (PTR_ERR(dup) != -ENOENT) { 1198 if (IS_ERR(dup)) 1199 return PTR_ERR(dup); 1200 *ext2 = &dup->ext; 1201 return -ENOTEMPTY; 1202 } 1203 1204 /* Validate */ 1205 nft_pipapo_for_each_field(f, i, m) { 1206 const u8 *start_p = start, *end_p = end; 1207 1208 if (f->rules >= (unsigned long)NFT_PIPAPO_RULE0_MAX) 1209 return -ENOSPC; 1210 1211 if (memcmp(start_p, end_p, 1212 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) > 0) 1213 return -EINVAL; 1214 1215 start_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1216 end_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1217 } 1218 1219 /* Insert */ 1220 priv->dirty = true; 1221 1222 bsize_max = m->bsize_max; 1223 1224 nft_pipapo_for_each_field(f, i, m) { 1225 int ret; 1226 1227 rulemap[i].to = f->rules; 1228 1229 ret = memcmp(start, end, 1230 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)); 1231 if (!ret) 1232 ret = pipapo_insert(f, start, f->groups * f->bb); 1233 else 1234 ret = pipapo_expand(f, start, end, f->groups * f->bb); 1235 1236 if (f->bsize > bsize_max) 1237 bsize_max = f->bsize; 1238 1239 rulemap[i].n = ret; 1240 1241 start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1242 end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1243 } 1244 1245 if (!*get_cpu_ptr(m->scratch) || bsize_max > m->bsize_max) { 1246 put_cpu_ptr(m->scratch); 1247 1248 err = pipapo_realloc_scratch(m, bsize_max); 1249 if (err) 1250 return err; 1251 1252 m->bsize_max = bsize_max; 1253 } else { 1254 put_cpu_ptr(m->scratch); 1255 } 1256 1257 *ext2 = &e->ext; 1258 1259 pipapo_map(m, rulemap, e); 1260 1261 return 0; 1262 } 1263 1264 /** 1265 * pipapo_clone() - Clone matching data to create new working copy 1266 * @old: Existing matching data 1267 * 1268 * Return: copy of matching data passed as 'old', error pointer on failure 1269 */ 1270 static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old) 1271 { 1272 struct nft_pipapo_field *dst, *src; 1273 struct nft_pipapo_match *new; 1274 int i; 1275 1276 new = kmalloc(sizeof(*new) + sizeof(*dst) * old->field_count, 1277 GFP_KERNEL); 1278 if (!new) 1279 return ERR_PTR(-ENOMEM); 1280 1281 new->field_count = old->field_count; 1282 new->bsize_max = old->bsize_max; 1283 1284 new->scratch = alloc_percpu(*new->scratch); 1285 if (!new->scratch) 1286 goto out_scratch; 1287 1288 #ifdef NFT_PIPAPO_ALIGN 1289 new->scratch_aligned = alloc_percpu(*new->scratch_aligned); 1290 if (!new->scratch_aligned) 1291 goto out_scratch; 1292 #endif 1293 1294 rcu_head_init(&new->rcu); 1295 1296 src = old->f; 1297 dst = new->f; 1298 1299 for (i = 0; i < old->field_count; i++) { 1300 unsigned long *new_lt; 1301 1302 memcpy(dst, src, offsetof(struct nft_pipapo_field, lt)); 1303 1304 new_lt = kvzalloc(src->groups * NFT_PIPAPO_BUCKETS(src->bb) * 1305 src->bsize * sizeof(*dst->lt) + 1306 NFT_PIPAPO_ALIGN_HEADROOM, 1307 GFP_KERNEL); 1308 if (!new_lt) 1309 goto out_lt; 1310 1311 NFT_PIPAPO_LT_ASSIGN(dst, new_lt); 1312 1313 memcpy(NFT_PIPAPO_LT_ALIGN(new_lt), 1314 NFT_PIPAPO_LT_ALIGN(src->lt), 1315 src->bsize * sizeof(*dst->lt) * 1316 src->groups * NFT_PIPAPO_BUCKETS(src->bb)); 1317 1318 dst->mt = kvmalloc(src->rules * sizeof(*src->mt), GFP_KERNEL); 1319 if (!dst->mt) 1320 goto out_mt; 1321 1322 memcpy(dst->mt, src->mt, src->rules * sizeof(*src->mt)); 1323 src++; 1324 dst++; 1325 } 1326 1327 return new; 1328 1329 out_mt: 1330 kvfree(dst->lt); 1331 out_lt: 1332 for (dst--; i > 0; i--) { 1333 kvfree(dst->mt); 1334 kvfree(dst->lt); 1335 dst--; 1336 } 1337 #ifdef NFT_PIPAPO_ALIGN 1338 free_percpu(new->scratch_aligned); 1339 #endif 1340 out_scratch: 1341 free_percpu(new->scratch); 1342 kfree(new); 1343 1344 return ERR_PTR(-ENOMEM); 1345 } 1346 1347 /** 1348 * pipapo_rules_same_key() - Get number of rules originated from the same entry 1349 * @f: Field containing mapping table 1350 * @first: Index of first rule in set of rules mapping to same entry 1351 * 1352 * Using the fact that all rules in a field that originated from the same entry 1353 * will map to the same set of rules in the next field, or to the same element 1354 * reference, return the cardinality of the set of rules that originated from 1355 * the same entry as the rule with index @first, @first rule included. 1356 * 1357 * In pictures: 1358 * rules 1359 * field #0 0 1 2 3 4 1360 * map to: 0 1 2-4 2-4 5-9 1361 * . . ....... . ... 1362 * | | | | \ \ 1363 * | | | | \ \ 1364 * | | | | \ \ 1365 * ' ' ' ' ' \ 1366 * in field #1 0 1 2 3 4 5 ... 1367 * 1368 * if this is called for rule 2 on field #0, it will return 3, as also rules 2 1369 * and 3 in field 0 map to the same set of rules (2, 3, 4) in the next field. 1370 * 1371 * For the last field in a set, we can rely on associated entries to map to the 1372 * same element references. 1373 * 1374 * Return: Number of rules that originated from the same entry as @first. 1375 */ 1376 static int pipapo_rules_same_key(struct nft_pipapo_field *f, int first) 1377 { 1378 struct nft_pipapo_elem *e = NULL; /* Keep gcc happy */ 1379 int r; 1380 1381 for (r = first; r < f->rules; r++) { 1382 if (r != first && e != f->mt[r].e) 1383 return r - first; 1384 1385 e = f->mt[r].e; 1386 } 1387 1388 if (r != first) 1389 return r - first; 1390 1391 return 0; 1392 } 1393 1394 /** 1395 * pipapo_unmap() - Remove rules from mapping tables, renumber remaining ones 1396 * @mt: Mapping array 1397 * @rules: Original amount of rules in mapping table 1398 * @start: First rule index to be removed 1399 * @n: Amount of rules to be removed 1400 * @to_offset: First rule index, in next field, this group of rules maps to 1401 * @is_last: If this is the last field, delete reference from mapping array 1402 * 1403 * This is used to unmap rules from the mapping table for a single field, 1404 * maintaining consistency and compactness for the existing ones. 1405 * 1406 * In pictures: let's assume that we want to delete rules 2 and 3 from the 1407 * following mapping array: 1408 * 1409 * rules 1410 * 0 1 2 3 4 1411 * map to: 4-10 4-10 11-15 11-15 16-18 1412 * 1413 * the result will be: 1414 * 1415 * rules 1416 * 0 1 2 1417 * map to: 4-10 4-10 11-13 1418 * 1419 * for fields before the last one. In case this is the mapping table for the 1420 * last field in a set, and rules map to pointers to &struct nft_pipapo_elem: 1421 * 1422 * rules 1423 * 0 1 2 3 4 1424 * element pointers: 0x42 0x42 0x33 0x33 0x44 1425 * 1426 * the result will be: 1427 * 1428 * rules 1429 * 0 1 2 1430 * element pointers: 0x42 0x42 0x44 1431 */ 1432 static void pipapo_unmap(union nft_pipapo_map_bucket *mt, int rules, 1433 int start, int n, int to_offset, bool is_last) 1434 { 1435 int i; 1436 1437 memmove(mt + start, mt + start + n, (rules - start - n) * sizeof(*mt)); 1438 memset(mt + rules - n, 0, n * sizeof(*mt)); 1439 1440 if (is_last) 1441 return; 1442 1443 for (i = start; i < rules - n; i++) 1444 mt[i].to -= to_offset; 1445 } 1446 1447 /** 1448 * pipapo_drop() - Delete entry from lookup and mapping tables, given rule map 1449 * @m: Matching data 1450 * @rulemap: Table of rule maps, arrays of first rule and amount of rules 1451 * in next field a given entry maps to, for each field 1452 * 1453 * For each rule in lookup table buckets mapping to this set of rules, drop 1454 * all bits set in lookup table mapping. In pictures, assuming we want to drop 1455 * rules 0 and 1 from this lookup table: 1456 * 1457 * bucket 1458 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1459 * 0 0 1,2 1460 * 1 1,2 0 1461 * 2 0 1,2 1462 * 3 0 1,2 1463 * 4 0,1,2 1464 * 5 0 1 2 1465 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1466 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1 1467 * 1468 * rule 2 becomes rule 0, and the result will be: 1469 * 1470 * bucket 1471 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1472 * 0 0 1473 * 1 0 1474 * 2 0 1475 * 3 0 1476 * 4 0 1477 * 5 0 1478 * 6 0 1479 * 7 0 0 1480 * 1481 * once this is done, call unmap() to drop all the corresponding rule references 1482 * from mapping tables. 1483 */ 1484 static void pipapo_drop(struct nft_pipapo_match *m, 1485 union nft_pipapo_map_bucket rulemap[]) 1486 { 1487 struct nft_pipapo_field *f; 1488 int i; 1489 1490 nft_pipapo_for_each_field(f, i, m) { 1491 int g; 1492 1493 for (g = 0; g < f->groups; g++) { 1494 unsigned long *pos; 1495 int b; 1496 1497 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + g * 1498 NFT_PIPAPO_BUCKETS(f->bb) * f->bsize; 1499 1500 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) { 1501 bitmap_cut(pos, pos, rulemap[i].to, 1502 rulemap[i].n, 1503 f->bsize * BITS_PER_LONG); 1504 1505 pos += f->bsize; 1506 } 1507 } 1508 1509 pipapo_unmap(f->mt, f->rules, rulemap[i].to, rulemap[i].n, 1510 rulemap[i + 1].n, i == m->field_count - 1); 1511 if (pipapo_resize(f, f->rules, f->rules - rulemap[i].n)) { 1512 /* We can ignore this, a failure to shrink tables down 1513 * doesn't make tables invalid. 1514 */ 1515 ; 1516 } 1517 f->rules -= rulemap[i].n; 1518 1519 pipapo_lt_bits_adjust(f); 1520 } 1521 } 1522 1523 /** 1524 * pipapo_gc() - Drop expired entries from set, destroy start and end elements 1525 * @set: nftables API set representation 1526 * @m: Matching data 1527 */ 1528 static void pipapo_gc(const struct nft_set *set, struct nft_pipapo_match *m) 1529 { 1530 struct nft_pipapo *priv = nft_set_priv(set); 1531 int rules_f0, first_rule = 0; 1532 struct nft_pipapo_elem *e; 1533 1534 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { 1535 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1536 struct nft_pipapo_field *f; 1537 int i, start, rules_fx; 1538 1539 start = first_rule; 1540 rules_fx = rules_f0; 1541 1542 nft_pipapo_for_each_field(f, i, m) { 1543 rulemap[i].to = start; 1544 rulemap[i].n = rules_fx; 1545 1546 if (i < m->field_count - 1) { 1547 rules_fx = f->mt[start].n; 1548 start = f->mt[start].to; 1549 } 1550 } 1551 1552 /* Pick the last field, and its last index */ 1553 f--; 1554 i--; 1555 e = f->mt[rulemap[i].to].e; 1556 if (nft_set_elem_expired(&e->ext) && 1557 !nft_set_elem_mark_busy(&e->ext)) { 1558 priv->dirty = true; 1559 pipapo_drop(m, rulemap); 1560 1561 rcu_barrier(); 1562 nft_set_elem_destroy(set, e, true); 1563 1564 /* And check again current first rule, which is now the 1565 * first we haven't checked. 1566 */ 1567 } else { 1568 first_rule += rules_f0; 1569 } 1570 } 1571 1572 e = nft_set_catchall_gc(set); 1573 if (e) 1574 nft_set_elem_destroy(set, e, true); 1575 1576 priv->last_gc = jiffies; 1577 } 1578 1579 /** 1580 * pipapo_free_fields() - Free per-field tables contained in matching data 1581 * @m: Matching data 1582 */ 1583 static void pipapo_free_fields(struct nft_pipapo_match *m) 1584 { 1585 struct nft_pipapo_field *f; 1586 int i; 1587 1588 nft_pipapo_for_each_field(f, i, m) { 1589 kvfree(f->lt); 1590 kvfree(f->mt); 1591 } 1592 } 1593 1594 /** 1595 * pipapo_reclaim_match - RCU callback to free fields from old matching data 1596 * @rcu: RCU head 1597 */ 1598 static void pipapo_reclaim_match(struct rcu_head *rcu) 1599 { 1600 struct nft_pipapo_match *m; 1601 int i; 1602 1603 m = container_of(rcu, struct nft_pipapo_match, rcu); 1604 1605 for_each_possible_cpu(i) 1606 kfree(*per_cpu_ptr(m->scratch, i)); 1607 1608 #ifdef NFT_PIPAPO_ALIGN 1609 free_percpu(m->scratch_aligned); 1610 #endif 1611 free_percpu(m->scratch); 1612 1613 pipapo_free_fields(m); 1614 1615 kfree(m); 1616 } 1617 1618 /** 1619 * pipapo_commit() - Replace lookup data with current working copy 1620 * @set: nftables API set representation 1621 * 1622 * While at it, check if we should perform garbage collection on the working 1623 * copy before committing it for lookup, and don't replace the table if the 1624 * working copy doesn't have pending changes. 1625 * 1626 * We also need to create a new working copy for subsequent insertions and 1627 * deletions. 1628 */ 1629 static void pipapo_commit(const struct nft_set *set) 1630 { 1631 struct nft_pipapo *priv = nft_set_priv(set); 1632 struct nft_pipapo_match *new_clone, *old; 1633 1634 if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set))) 1635 pipapo_gc(set, priv->clone); 1636 1637 if (!priv->dirty) 1638 return; 1639 1640 new_clone = pipapo_clone(priv->clone); 1641 if (IS_ERR(new_clone)) 1642 return; 1643 1644 priv->dirty = false; 1645 1646 old = rcu_access_pointer(priv->match); 1647 rcu_assign_pointer(priv->match, priv->clone); 1648 if (old) 1649 call_rcu(&old->rcu, pipapo_reclaim_match); 1650 1651 priv->clone = new_clone; 1652 } 1653 1654 /** 1655 * nft_pipapo_activate() - Mark element reference as active given key, commit 1656 * @net: Network namespace 1657 * @set: nftables API set representation 1658 * @elem: nftables API element representation containing key data 1659 * 1660 * On insertion, elements are added to a copy of the matching data currently 1661 * in use for lookups, and not directly inserted into current lookup data, so 1662 * we'll take care of that by calling pipapo_commit() here. Both 1663 * nft_pipapo_insert() and nft_pipapo_activate() are called once for each 1664 * element, hence we can't purpose either one as a real commit operation. 1665 */ 1666 static void nft_pipapo_activate(const struct net *net, 1667 const struct nft_set *set, 1668 const struct nft_set_elem *elem) 1669 { 1670 struct nft_pipapo_elem *e; 1671 1672 e = pipapo_get(net, set, (const u8 *)elem->key.val.data, 0); 1673 if (IS_ERR(e)) 1674 return; 1675 1676 nft_set_elem_change_active(net, set, &e->ext); 1677 nft_set_elem_clear_busy(&e->ext); 1678 1679 pipapo_commit(set); 1680 } 1681 1682 /** 1683 * pipapo_deactivate() - Check that element is in set, mark as inactive 1684 * @net: Network namespace 1685 * @set: nftables API set representation 1686 * @data: Input key data 1687 * @ext: nftables API extension pointer, used to check for end element 1688 * 1689 * This is a convenience function that can be called from both 1690 * nft_pipapo_deactivate() and nft_pipapo_flush(), as they are in fact the same 1691 * operation. 1692 * 1693 * Return: deactivated element if found, NULL otherwise. 1694 */ 1695 static void *pipapo_deactivate(const struct net *net, const struct nft_set *set, 1696 const u8 *data, const struct nft_set_ext *ext) 1697 { 1698 struct nft_pipapo_elem *e; 1699 1700 e = pipapo_get(net, set, data, nft_genmask_next(net)); 1701 if (IS_ERR(e)) 1702 return NULL; 1703 1704 nft_set_elem_change_active(net, set, &e->ext); 1705 1706 return e; 1707 } 1708 1709 /** 1710 * nft_pipapo_deactivate() - Call pipapo_deactivate() to make element inactive 1711 * @net: Network namespace 1712 * @set: nftables API set representation 1713 * @elem: nftables API element representation containing key data 1714 * 1715 * Return: deactivated element if found, NULL otherwise. 1716 */ 1717 static void *nft_pipapo_deactivate(const struct net *net, 1718 const struct nft_set *set, 1719 const struct nft_set_elem *elem) 1720 { 1721 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); 1722 1723 return pipapo_deactivate(net, set, (const u8 *)elem->key.val.data, ext); 1724 } 1725 1726 /** 1727 * nft_pipapo_flush() - Call pipapo_deactivate() to make element inactive 1728 * @net: Network namespace 1729 * @set: nftables API set representation 1730 * @elem: nftables API element representation containing key data 1731 * 1732 * This is functionally the same as nft_pipapo_deactivate(), with a slightly 1733 * different interface, and it's also called once for each element in a set 1734 * being flushed, so we can't implement, strictly speaking, a flush operation, 1735 * which would otherwise be as simple as allocating an empty copy of the 1736 * matching data. 1737 * 1738 * Note that we could in theory do that, mark the set as flushed, and ignore 1739 * subsequent calls, but we would leak all the elements after the first one, 1740 * because they wouldn't then be freed as result of API calls. 1741 * 1742 * Return: true if element was found and deactivated. 1743 */ 1744 static bool nft_pipapo_flush(const struct net *net, const struct nft_set *set, 1745 void *elem) 1746 { 1747 struct nft_pipapo_elem *e = elem; 1748 1749 return pipapo_deactivate(net, set, (const u8 *)nft_set_ext_key(&e->ext), 1750 &e->ext); 1751 } 1752 1753 /** 1754 * pipapo_get_boundaries() - Get byte interval for associated rules 1755 * @f: Field including lookup table 1756 * @first_rule: First rule (lowest index) 1757 * @rule_count: Number of associated rules 1758 * @left: Byte expression for left boundary (start of range) 1759 * @right: Byte expression for right boundary (end of range) 1760 * 1761 * Given the first rule and amount of rules that originated from the same entry, 1762 * build the original range associated with the entry, and calculate the length 1763 * of the originating netmask. 1764 * 1765 * In pictures: 1766 * 1767 * bucket 1768 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1769 * 0 1,2 1770 * 1 1,2 1771 * 2 1,2 1772 * 3 1,2 1773 * 4 1,2 1774 * 5 1 2 1775 * 6 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1776 * 7 1,2 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1777 * 1778 * this is the lookup table corresponding to the IPv4 range 1779 * 192.168.1.0-192.168.2.1, which was expanded to the two composing netmasks, 1780 * rule #1: 192.168.1.0/24, and rule #2: 192.168.2.0/31. 1781 * 1782 * This function fills @left and @right with the byte values of the leftmost 1783 * and rightmost bucket indices for the lowest and highest rule indices, 1784 * respectively. If @first_rule is 1 and @rule_count is 2, we obtain, in 1785 * nibbles: 1786 * left: < 12, 0, 10, 8, 0, 1, 0, 0 > 1787 * right: < 12, 0, 10, 8, 0, 2, 2, 1 > 1788 * corresponding to bytes: 1789 * left: < 192, 168, 1, 0 > 1790 * right: < 192, 168, 2, 1 > 1791 * with mask length irrelevant here, unused on return, as the range is already 1792 * defined by its start and end points. The mask length is relevant for a single 1793 * ranged entry instead: if @first_rule is 1 and @rule_count is 1, we ignore 1794 * rule 2 above: @left becomes < 192, 168, 1, 0 >, @right becomes 1795 * < 192, 168, 1, 255 >, and the mask length, calculated from the distances 1796 * between leftmost and rightmost bucket indices for each group, would be 24. 1797 * 1798 * Return: mask length, in bits. 1799 */ 1800 static int pipapo_get_boundaries(struct nft_pipapo_field *f, int first_rule, 1801 int rule_count, u8 *left, u8 *right) 1802 { 1803 int g, mask_len = 0, bit_offset = 0; 1804 u8 *l = left, *r = right; 1805 1806 for (g = 0; g < f->groups; g++) { 1807 int b, x0, x1; 1808 1809 x0 = -1; 1810 x1 = -1; 1811 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) { 1812 unsigned long *pos; 1813 1814 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + 1815 (g * NFT_PIPAPO_BUCKETS(f->bb) + b) * f->bsize; 1816 if (test_bit(first_rule, pos) && x0 == -1) 1817 x0 = b; 1818 if (test_bit(first_rule + rule_count - 1, pos)) 1819 x1 = b; 1820 } 1821 1822 *l |= x0 << (BITS_PER_BYTE - f->bb - bit_offset); 1823 *r |= x1 << (BITS_PER_BYTE - f->bb - bit_offset); 1824 1825 bit_offset += f->bb; 1826 if (bit_offset >= BITS_PER_BYTE) { 1827 bit_offset %= BITS_PER_BYTE; 1828 l++; 1829 r++; 1830 } 1831 1832 if (x1 - x0 == 0) 1833 mask_len += 4; 1834 else if (x1 - x0 == 1) 1835 mask_len += 3; 1836 else if (x1 - x0 == 3) 1837 mask_len += 2; 1838 else if (x1 - x0 == 7) 1839 mask_len += 1; 1840 } 1841 1842 return mask_len; 1843 } 1844 1845 /** 1846 * pipapo_match_field() - Match rules against byte ranges 1847 * @f: Field including the lookup table 1848 * @first_rule: First of associated rules originating from same entry 1849 * @rule_count: Amount of associated rules 1850 * @start: Start of range to be matched 1851 * @end: End of range to be matched 1852 * 1853 * Return: true on match, false otherwise. 1854 */ 1855 static bool pipapo_match_field(struct nft_pipapo_field *f, 1856 int first_rule, int rule_count, 1857 const u8 *start, const u8 *end) 1858 { 1859 u8 right[NFT_PIPAPO_MAX_BYTES] = { 0 }; 1860 u8 left[NFT_PIPAPO_MAX_BYTES] = { 0 }; 1861 1862 pipapo_get_boundaries(f, first_rule, rule_count, left, right); 1863 1864 return !memcmp(start, left, 1865 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) && 1866 !memcmp(end, right, f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)); 1867 } 1868 1869 /** 1870 * nft_pipapo_remove() - Remove element given key, commit 1871 * @net: Network namespace 1872 * @set: nftables API set representation 1873 * @elem: nftables API element representation containing key data 1874 * 1875 * Similarly to nft_pipapo_activate(), this is used as commit operation by the 1876 * API, but it's called once per element in the pending transaction, so we can't 1877 * implement this as a single commit operation. Closest we can get is to remove 1878 * the matched element here, if any, and commit the updated matching data. 1879 */ 1880 static void nft_pipapo_remove(const struct net *net, const struct nft_set *set, 1881 const struct nft_set_elem *elem) 1882 { 1883 struct nft_pipapo *priv = nft_set_priv(set); 1884 struct nft_pipapo_match *m = priv->clone; 1885 struct nft_pipapo_elem *e = elem->priv; 1886 int rules_f0, first_rule = 0; 1887 const u8 *data; 1888 1889 data = (const u8 *)nft_set_ext_key(&e->ext); 1890 1891 e = pipapo_get(net, set, data, 0); 1892 if (IS_ERR(e)) 1893 return; 1894 1895 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { 1896 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1897 const u8 *match_start, *match_end; 1898 struct nft_pipapo_field *f; 1899 int i, start, rules_fx; 1900 1901 match_start = data; 1902 match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; 1903 1904 start = first_rule; 1905 rules_fx = rules_f0; 1906 1907 nft_pipapo_for_each_field(f, i, m) { 1908 if (!pipapo_match_field(f, start, rules_fx, 1909 match_start, match_end)) 1910 break; 1911 1912 rulemap[i].to = start; 1913 rulemap[i].n = rules_fx; 1914 1915 rules_fx = f->mt[start].n; 1916 start = f->mt[start].to; 1917 1918 match_start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1919 match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1920 } 1921 1922 if (i == m->field_count) { 1923 priv->dirty = true; 1924 pipapo_drop(m, rulemap); 1925 pipapo_commit(set); 1926 return; 1927 } 1928 1929 first_rule += rules_f0; 1930 } 1931 } 1932 1933 /** 1934 * nft_pipapo_walk() - Walk over elements 1935 * @ctx: nftables API context 1936 * @set: nftables API set representation 1937 * @iter: Iterator 1938 * 1939 * As elements are referenced in the mapping array for the last field, directly 1940 * scan that array: there's no need to follow rule mappings from the first 1941 * field. 1942 */ 1943 static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, 1944 struct nft_set_iter *iter) 1945 { 1946 struct nft_pipapo *priv = nft_set_priv(set); 1947 struct nft_pipapo_match *m; 1948 struct nft_pipapo_field *f; 1949 int i, r; 1950 1951 rcu_read_lock(); 1952 m = rcu_dereference(priv->match); 1953 1954 if (unlikely(!m)) 1955 goto out; 1956 1957 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) 1958 ; 1959 1960 for (r = 0; r < f->rules; r++) { 1961 struct nft_pipapo_elem *e; 1962 struct nft_set_elem elem; 1963 1964 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e) 1965 continue; 1966 1967 if (iter->count < iter->skip) 1968 goto cont; 1969 1970 e = f->mt[r].e; 1971 if (nft_set_elem_expired(&e->ext)) 1972 goto cont; 1973 1974 elem.priv = e; 1975 1976 iter->err = iter->fn(ctx, set, iter, &elem); 1977 if (iter->err < 0) 1978 goto out; 1979 1980 cont: 1981 iter->count++; 1982 } 1983 1984 out: 1985 rcu_read_unlock(); 1986 } 1987 1988 /** 1989 * nft_pipapo_privsize() - Return the size of private data for the set 1990 * @nla: netlink attributes, ignored as size doesn't depend on them 1991 * @desc: Set description, ignored as size doesn't depend on it 1992 * 1993 * Return: size of private data for this set implementation, in bytes 1994 */ 1995 static u64 nft_pipapo_privsize(const struct nlattr * const nla[], 1996 const struct nft_set_desc *desc) 1997 { 1998 return sizeof(struct nft_pipapo); 1999 } 2000 2001 /** 2002 * nft_pipapo_estimate() - Set size, space and lookup complexity 2003 * @desc: Set description, element count and field description used 2004 * @features: Flags: NFT_SET_INTERVAL needs to be there 2005 * @est: Storage for estimation data 2006 * 2007 * Return: true if set description is compatible, false otherwise 2008 */ 2009 static bool nft_pipapo_estimate(const struct nft_set_desc *desc, u32 features, 2010 struct nft_set_estimate *est) 2011 { 2012 if (!(features & NFT_SET_INTERVAL) || 2013 desc->field_count < NFT_PIPAPO_MIN_FIELDS) 2014 return false; 2015 2016 est->size = pipapo_estimate_size(desc); 2017 if (!est->size) 2018 return false; 2019 2020 est->lookup = NFT_SET_CLASS_O_LOG_N; 2021 2022 est->space = NFT_SET_CLASS_O_N; 2023 2024 return true; 2025 } 2026 2027 /** 2028 * nft_pipapo_init() - Initialise data for a set instance 2029 * @set: nftables API set representation 2030 * @desc: Set description 2031 * @nla: netlink attributes 2032 * 2033 * Validate number and size of fields passed as NFTA_SET_DESC_CONCAT netlink 2034 * attributes, initialise internal set parameters, current instance of matching 2035 * data and a copy for subsequent insertions. 2036 * 2037 * Return: 0 on success, negative error code on failure. 2038 */ 2039 static int nft_pipapo_init(const struct nft_set *set, 2040 const struct nft_set_desc *desc, 2041 const struct nlattr * const nla[]) 2042 { 2043 struct nft_pipapo *priv = nft_set_priv(set); 2044 struct nft_pipapo_match *m; 2045 struct nft_pipapo_field *f; 2046 int err, i, field_count; 2047 2048 field_count = desc->field_count ? : 1; 2049 2050 if (field_count > NFT_PIPAPO_MAX_FIELDS) 2051 return -EINVAL; 2052 2053 m = kmalloc(sizeof(*priv->match) + sizeof(*f) * field_count, 2054 GFP_KERNEL); 2055 if (!m) 2056 return -ENOMEM; 2057 2058 m->field_count = field_count; 2059 m->bsize_max = 0; 2060 2061 m->scratch = alloc_percpu(unsigned long *); 2062 if (!m->scratch) { 2063 err = -ENOMEM; 2064 goto out_scratch; 2065 } 2066 for_each_possible_cpu(i) 2067 *per_cpu_ptr(m->scratch, i) = NULL; 2068 2069 #ifdef NFT_PIPAPO_ALIGN 2070 m->scratch_aligned = alloc_percpu(unsigned long *); 2071 if (!m->scratch_aligned) { 2072 err = -ENOMEM; 2073 goto out_free; 2074 } 2075 for_each_possible_cpu(i) 2076 *per_cpu_ptr(m->scratch_aligned, i) = NULL; 2077 #endif 2078 2079 rcu_head_init(&m->rcu); 2080 2081 nft_pipapo_for_each_field(f, i, m) { 2082 int len = desc->field_len[i] ? : set->klen; 2083 2084 f->bb = NFT_PIPAPO_GROUP_BITS_INIT; 2085 f->groups = len * NFT_PIPAPO_GROUPS_PER_BYTE(f); 2086 2087 priv->width += round_up(len, sizeof(u32)); 2088 2089 f->bsize = 0; 2090 f->rules = 0; 2091 NFT_PIPAPO_LT_ASSIGN(f, NULL); 2092 f->mt = NULL; 2093 } 2094 2095 /* Create an initial clone of matching data for next insertion */ 2096 priv->clone = pipapo_clone(m); 2097 if (IS_ERR(priv->clone)) { 2098 err = PTR_ERR(priv->clone); 2099 goto out_free; 2100 } 2101 2102 priv->dirty = false; 2103 2104 rcu_assign_pointer(priv->match, m); 2105 2106 return 0; 2107 2108 out_free: 2109 #ifdef NFT_PIPAPO_ALIGN 2110 free_percpu(m->scratch_aligned); 2111 #endif 2112 free_percpu(m->scratch); 2113 out_scratch: 2114 kfree(m); 2115 2116 return err; 2117 } 2118 2119 /** 2120 * nft_pipapo_destroy() - Free private data for set and all committed elements 2121 * @set: nftables API set representation 2122 */ 2123 static void nft_pipapo_destroy(const struct nft_set *set) 2124 { 2125 struct nft_pipapo *priv = nft_set_priv(set); 2126 struct nft_pipapo_match *m; 2127 struct nft_pipapo_field *f; 2128 int i, r, cpu; 2129 2130 m = rcu_dereference_protected(priv->match, true); 2131 if (m) { 2132 rcu_barrier(); 2133 2134 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) 2135 ; 2136 2137 for (r = 0; r < f->rules; r++) { 2138 struct nft_pipapo_elem *e; 2139 2140 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e) 2141 continue; 2142 2143 e = f->mt[r].e; 2144 2145 nft_set_elem_destroy(set, e, true); 2146 } 2147 2148 #ifdef NFT_PIPAPO_ALIGN 2149 free_percpu(m->scratch_aligned); 2150 #endif 2151 for_each_possible_cpu(cpu) 2152 kfree(*per_cpu_ptr(m->scratch, cpu)); 2153 free_percpu(m->scratch); 2154 pipapo_free_fields(m); 2155 kfree(m); 2156 priv->match = NULL; 2157 } 2158 2159 if (priv->clone) { 2160 #ifdef NFT_PIPAPO_ALIGN 2161 free_percpu(priv->clone->scratch_aligned); 2162 #endif 2163 for_each_possible_cpu(cpu) 2164 kfree(*per_cpu_ptr(priv->clone->scratch, cpu)); 2165 free_percpu(priv->clone->scratch); 2166 2167 pipapo_free_fields(priv->clone); 2168 kfree(priv->clone); 2169 priv->clone = NULL; 2170 } 2171 } 2172 2173 /** 2174 * nft_pipapo_gc_init() - Initialise garbage collection 2175 * @set: nftables API set representation 2176 * 2177 * Instead of actually setting up a periodic work for garbage collection, as 2178 * this operation requires a swap of matching data with the working copy, we'll 2179 * do that opportunistically with other commit operations if the interval is 2180 * elapsed, so we just need to set the current jiffies timestamp here. 2181 */ 2182 static void nft_pipapo_gc_init(const struct nft_set *set) 2183 { 2184 struct nft_pipapo *priv = nft_set_priv(set); 2185 2186 priv->last_gc = jiffies; 2187 } 2188 2189 const struct nft_set_type nft_set_pipapo_type = { 2190 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | 2191 NFT_SET_TIMEOUT, 2192 .ops = { 2193 .lookup = nft_pipapo_lookup, 2194 .insert = nft_pipapo_insert, 2195 .activate = nft_pipapo_activate, 2196 .deactivate = nft_pipapo_deactivate, 2197 .flush = nft_pipapo_flush, 2198 .remove = nft_pipapo_remove, 2199 .walk = nft_pipapo_walk, 2200 .get = nft_pipapo_get, 2201 .privsize = nft_pipapo_privsize, 2202 .estimate = nft_pipapo_estimate, 2203 .init = nft_pipapo_init, 2204 .destroy = nft_pipapo_destroy, 2205 .gc_init = nft_pipapo_gc_init, 2206 .elemsize = offsetof(struct nft_pipapo_elem, ext), 2207 }, 2208 }; 2209 2210 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML) 2211 const struct nft_set_type nft_set_pipapo_avx2_type = { 2212 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | 2213 NFT_SET_TIMEOUT, 2214 .ops = { 2215 .lookup = nft_pipapo_avx2_lookup, 2216 .insert = nft_pipapo_insert, 2217 .activate = nft_pipapo_activate, 2218 .deactivate = nft_pipapo_deactivate, 2219 .flush = nft_pipapo_flush, 2220 .remove = nft_pipapo_remove, 2221 .walk = nft_pipapo_walk, 2222 .get = nft_pipapo_get, 2223 .privsize = nft_pipapo_privsize, 2224 .estimate = nft_pipapo_avx2_estimate, 2225 .init = nft_pipapo_init, 2226 .destroy = nft_pipapo_destroy, 2227 .gc_init = nft_pipapo_gc_init, 2228 .elemsize = offsetof(struct nft_pipapo_elem, ext), 2229 }, 2230 }; 2231 #endif 2232