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 const u8 *start_p, *end_p; 1166 int i, bsize_max, err = 0; 1167 1168 if (nft_set_ext_exists(ext, NFT_SET_EXT_KEY_END)) 1169 end = (const u8 *)nft_set_ext_key_end(ext)->data; 1170 else 1171 end = start; 1172 1173 dup = pipapo_get(net, set, start, genmask); 1174 if (!IS_ERR(dup)) { 1175 /* Check if we already have the same exact entry */ 1176 const struct nft_data *dup_key, *dup_end; 1177 1178 dup_key = nft_set_ext_key(&dup->ext); 1179 if (nft_set_ext_exists(&dup->ext, NFT_SET_EXT_KEY_END)) 1180 dup_end = nft_set_ext_key_end(&dup->ext); 1181 else 1182 dup_end = dup_key; 1183 1184 if (!memcmp(start, dup_key->data, sizeof(*dup_key->data)) && 1185 !memcmp(end, dup_end->data, sizeof(*dup_end->data))) { 1186 *ext2 = &dup->ext; 1187 return -EEXIST; 1188 } 1189 1190 return -ENOTEMPTY; 1191 } 1192 1193 if (PTR_ERR(dup) == -ENOENT) { 1194 /* Look for partially overlapping entries */ 1195 dup = pipapo_get(net, set, end, nft_genmask_next(net)); 1196 } 1197 1198 if (PTR_ERR(dup) != -ENOENT) { 1199 if (IS_ERR(dup)) 1200 return PTR_ERR(dup); 1201 *ext2 = &dup->ext; 1202 return -ENOTEMPTY; 1203 } 1204 1205 /* Validate */ 1206 start_p = start; 1207 end_p = end; 1208 nft_pipapo_for_each_field(f, i, m) { 1209 if (f->rules >= (unsigned long)NFT_PIPAPO_RULE0_MAX) 1210 return -ENOSPC; 1211 1212 if (memcmp(start_p, end_p, 1213 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) > 0) 1214 return -EINVAL; 1215 1216 start_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1217 end_p += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1218 } 1219 1220 /* Insert */ 1221 priv->dirty = true; 1222 1223 bsize_max = m->bsize_max; 1224 1225 nft_pipapo_for_each_field(f, i, m) { 1226 int ret; 1227 1228 rulemap[i].to = f->rules; 1229 1230 ret = memcmp(start, end, 1231 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)); 1232 if (!ret) 1233 ret = pipapo_insert(f, start, f->groups * f->bb); 1234 else 1235 ret = pipapo_expand(f, start, end, f->groups * f->bb); 1236 1237 if (f->bsize > bsize_max) 1238 bsize_max = f->bsize; 1239 1240 rulemap[i].n = ret; 1241 1242 start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1243 end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1244 } 1245 1246 if (!*get_cpu_ptr(m->scratch) || bsize_max > m->bsize_max) { 1247 put_cpu_ptr(m->scratch); 1248 1249 err = pipapo_realloc_scratch(m, bsize_max); 1250 if (err) 1251 return err; 1252 1253 m->bsize_max = bsize_max; 1254 } else { 1255 put_cpu_ptr(m->scratch); 1256 } 1257 1258 *ext2 = &e->ext; 1259 1260 pipapo_map(m, rulemap, e); 1261 1262 return 0; 1263 } 1264 1265 /** 1266 * pipapo_clone() - Clone matching data to create new working copy 1267 * @old: Existing matching data 1268 * 1269 * Return: copy of matching data passed as 'old', error pointer on failure 1270 */ 1271 static struct nft_pipapo_match *pipapo_clone(struct nft_pipapo_match *old) 1272 { 1273 struct nft_pipapo_field *dst, *src; 1274 struct nft_pipapo_match *new; 1275 int i; 1276 1277 new = kmalloc(sizeof(*new) + sizeof(*dst) * old->field_count, 1278 GFP_KERNEL); 1279 if (!new) 1280 return ERR_PTR(-ENOMEM); 1281 1282 new->field_count = old->field_count; 1283 new->bsize_max = old->bsize_max; 1284 1285 new->scratch = alloc_percpu(*new->scratch); 1286 if (!new->scratch) 1287 goto out_scratch; 1288 1289 #ifdef NFT_PIPAPO_ALIGN 1290 new->scratch_aligned = alloc_percpu(*new->scratch_aligned); 1291 if (!new->scratch_aligned) 1292 goto out_scratch; 1293 #endif 1294 for_each_possible_cpu(i) 1295 *per_cpu_ptr(new->scratch, i) = NULL; 1296 1297 if (pipapo_realloc_scratch(new, old->bsize_max)) 1298 goto out_scratch_realloc; 1299 1300 rcu_head_init(&new->rcu); 1301 1302 src = old->f; 1303 dst = new->f; 1304 1305 for (i = 0; i < old->field_count; i++) { 1306 unsigned long *new_lt; 1307 1308 memcpy(dst, src, offsetof(struct nft_pipapo_field, lt)); 1309 1310 new_lt = kvzalloc(src->groups * NFT_PIPAPO_BUCKETS(src->bb) * 1311 src->bsize * sizeof(*dst->lt) + 1312 NFT_PIPAPO_ALIGN_HEADROOM, 1313 GFP_KERNEL); 1314 if (!new_lt) 1315 goto out_lt; 1316 1317 NFT_PIPAPO_LT_ASSIGN(dst, new_lt); 1318 1319 memcpy(NFT_PIPAPO_LT_ALIGN(new_lt), 1320 NFT_PIPAPO_LT_ALIGN(src->lt), 1321 src->bsize * sizeof(*dst->lt) * 1322 src->groups * NFT_PIPAPO_BUCKETS(src->bb)); 1323 1324 dst->mt = kvmalloc(src->rules * sizeof(*src->mt), GFP_KERNEL); 1325 if (!dst->mt) 1326 goto out_mt; 1327 1328 memcpy(dst->mt, src->mt, src->rules * sizeof(*src->mt)); 1329 src++; 1330 dst++; 1331 } 1332 1333 return new; 1334 1335 out_mt: 1336 kvfree(dst->lt); 1337 out_lt: 1338 for (dst--; i > 0; i--) { 1339 kvfree(dst->mt); 1340 kvfree(dst->lt); 1341 dst--; 1342 } 1343 out_scratch_realloc: 1344 for_each_possible_cpu(i) 1345 kfree(*per_cpu_ptr(new->scratch, i)); 1346 #ifdef NFT_PIPAPO_ALIGN 1347 free_percpu(new->scratch_aligned); 1348 #endif 1349 out_scratch: 1350 free_percpu(new->scratch); 1351 kfree(new); 1352 1353 return ERR_PTR(-ENOMEM); 1354 } 1355 1356 /** 1357 * pipapo_rules_same_key() - Get number of rules originated from the same entry 1358 * @f: Field containing mapping table 1359 * @first: Index of first rule in set of rules mapping to same entry 1360 * 1361 * Using the fact that all rules in a field that originated from the same entry 1362 * will map to the same set of rules in the next field, or to the same element 1363 * reference, return the cardinality of the set of rules that originated from 1364 * the same entry as the rule with index @first, @first rule included. 1365 * 1366 * In pictures: 1367 * rules 1368 * field #0 0 1 2 3 4 1369 * map to: 0 1 2-4 2-4 5-9 1370 * . . ....... . ... 1371 * | | | | \ \ 1372 * | | | | \ \ 1373 * | | | | \ \ 1374 * ' ' ' ' ' \ 1375 * in field #1 0 1 2 3 4 5 ... 1376 * 1377 * if this is called for rule 2 on field #0, it will return 3, as also rules 2 1378 * and 3 in field 0 map to the same set of rules (2, 3, 4) in the next field. 1379 * 1380 * For the last field in a set, we can rely on associated entries to map to the 1381 * same element references. 1382 * 1383 * Return: Number of rules that originated from the same entry as @first. 1384 */ 1385 static int pipapo_rules_same_key(struct nft_pipapo_field *f, int first) 1386 { 1387 struct nft_pipapo_elem *e = NULL; /* Keep gcc happy */ 1388 int r; 1389 1390 for (r = first; r < f->rules; r++) { 1391 if (r != first && e != f->mt[r].e) 1392 return r - first; 1393 1394 e = f->mt[r].e; 1395 } 1396 1397 if (r != first) 1398 return r - first; 1399 1400 return 0; 1401 } 1402 1403 /** 1404 * pipapo_unmap() - Remove rules from mapping tables, renumber remaining ones 1405 * @mt: Mapping array 1406 * @rules: Original amount of rules in mapping table 1407 * @start: First rule index to be removed 1408 * @n: Amount of rules to be removed 1409 * @to_offset: First rule index, in next field, this group of rules maps to 1410 * @is_last: If this is the last field, delete reference from mapping array 1411 * 1412 * This is used to unmap rules from the mapping table for a single field, 1413 * maintaining consistency and compactness for the existing ones. 1414 * 1415 * In pictures: let's assume that we want to delete rules 2 and 3 from the 1416 * following mapping array: 1417 * 1418 * rules 1419 * 0 1 2 3 4 1420 * map to: 4-10 4-10 11-15 11-15 16-18 1421 * 1422 * the result will be: 1423 * 1424 * rules 1425 * 0 1 2 1426 * map to: 4-10 4-10 11-13 1427 * 1428 * for fields before the last one. In case this is the mapping table for the 1429 * last field in a set, and rules map to pointers to &struct nft_pipapo_elem: 1430 * 1431 * rules 1432 * 0 1 2 3 4 1433 * element pointers: 0x42 0x42 0x33 0x33 0x44 1434 * 1435 * the result will be: 1436 * 1437 * rules 1438 * 0 1 2 1439 * element pointers: 0x42 0x42 0x44 1440 */ 1441 static void pipapo_unmap(union nft_pipapo_map_bucket *mt, int rules, 1442 int start, int n, int to_offset, bool is_last) 1443 { 1444 int i; 1445 1446 memmove(mt + start, mt + start + n, (rules - start - n) * sizeof(*mt)); 1447 memset(mt + rules - n, 0, n * sizeof(*mt)); 1448 1449 if (is_last) 1450 return; 1451 1452 for (i = start; i < rules - n; i++) 1453 mt[i].to -= to_offset; 1454 } 1455 1456 /** 1457 * pipapo_drop() - Delete entry from lookup and mapping tables, given rule map 1458 * @m: Matching data 1459 * @rulemap: Table of rule maps, arrays of first rule and amount of rules 1460 * in next field a given entry maps to, for each field 1461 * 1462 * For each rule in lookup table buckets mapping to this set of rules, drop 1463 * all bits set in lookup table mapping. In pictures, assuming we want to drop 1464 * rules 0 and 1 from this lookup table: 1465 * 1466 * bucket 1467 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1468 * 0 0 1,2 1469 * 1 1,2 0 1470 * 2 0 1,2 1471 * 3 0 1,2 1472 * 4 0,1,2 1473 * 5 0 1 2 1474 * 6 0,1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1475 * 7 1,2 1,2 1 1 1 0,1 1 1 1 1 1 1 1 1 1 1 1476 * 1477 * rule 2 becomes rule 0, and the result will be: 1478 * 1479 * bucket 1480 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1481 * 0 0 1482 * 1 0 1483 * 2 0 1484 * 3 0 1485 * 4 0 1486 * 5 0 1487 * 6 0 1488 * 7 0 0 1489 * 1490 * once this is done, call unmap() to drop all the corresponding rule references 1491 * from mapping tables. 1492 */ 1493 static void pipapo_drop(struct nft_pipapo_match *m, 1494 union nft_pipapo_map_bucket rulemap[]) 1495 { 1496 struct nft_pipapo_field *f; 1497 int i; 1498 1499 nft_pipapo_for_each_field(f, i, m) { 1500 int g; 1501 1502 for (g = 0; g < f->groups; g++) { 1503 unsigned long *pos; 1504 int b; 1505 1506 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + g * 1507 NFT_PIPAPO_BUCKETS(f->bb) * f->bsize; 1508 1509 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) { 1510 bitmap_cut(pos, pos, rulemap[i].to, 1511 rulemap[i].n, 1512 f->bsize * BITS_PER_LONG); 1513 1514 pos += f->bsize; 1515 } 1516 } 1517 1518 pipapo_unmap(f->mt, f->rules, rulemap[i].to, rulemap[i].n, 1519 rulemap[i + 1].n, i == m->field_count - 1); 1520 if (pipapo_resize(f, f->rules, f->rules - rulemap[i].n)) { 1521 /* We can ignore this, a failure to shrink tables down 1522 * doesn't make tables invalid. 1523 */ 1524 ; 1525 } 1526 f->rules -= rulemap[i].n; 1527 1528 pipapo_lt_bits_adjust(f); 1529 } 1530 } 1531 1532 /** 1533 * pipapo_gc() - Drop expired entries from set, destroy start and end elements 1534 * @set: nftables API set representation 1535 * @m: Matching data 1536 */ 1537 static void pipapo_gc(const struct nft_set *set, struct nft_pipapo_match *m) 1538 { 1539 struct nft_pipapo *priv = nft_set_priv(set); 1540 int rules_f0, first_rule = 0; 1541 struct nft_pipapo_elem *e; 1542 1543 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { 1544 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1545 struct nft_pipapo_field *f; 1546 int i, start, rules_fx; 1547 1548 start = first_rule; 1549 rules_fx = rules_f0; 1550 1551 nft_pipapo_for_each_field(f, i, m) { 1552 rulemap[i].to = start; 1553 rulemap[i].n = rules_fx; 1554 1555 if (i < m->field_count - 1) { 1556 rules_fx = f->mt[start].n; 1557 start = f->mt[start].to; 1558 } 1559 } 1560 1561 /* Pick the last field, and its last index */ 1562 f--; 1563 i--; 1564 e = f->mt[rulemap[i].to].e; 1565 if (nft_set_elem_expired(&e->ext) && 1566 !nft_set_elem_mark_busy(&e->ext)) { 1567 priv->dirty = true; 1568 pipapo_drop(m, rulemap); 1569 1570 rcu_barrier(); 1571 nft_set_elem_destroy(set, e, true); 1572 1573 /* And check again current first rule, which is now the 1574 * first we haven't checked. 1575 */ 1576 } else { 1577 first_rule += rules_f0; 1578 } 1579 } 1580 1581 e = nft_set_catchall_gc(set); 1582 if (e) 1583 nft_set_elem_destroy(set, e, true); 1584 1585 priv->last_gc = jiffies; 1586 } 1587 1588 /** 1589 * pipapo_free_fields() - Free per-field tables contained in matching data 1590 * @m: Matching data 1591 */ 1592 static void pipapo_free_fields(struct nft_pipapo_match *m) 1593 { 1594 struct nft_pipapo_field *f; 1595 int i; 1596 1597 nft_pipapo_for_each_field(f, i, m) { 1598 kvfree(f->lt); 1599 kvfree(f->mt); 1600 } 1601 } 1602 1603 /** 1604 * pipapo_reclaim_match - RCU callback to free fields from old matching data 1605 * @rcu: RCU head 1606 */ 1607 static void pipapo_reclaim_match(struct rcu_head *rcu) 1608 { 1609 struct nft_pipapo_match *m; 1610 int i; 1611 1612 m = container_of(rcu, struct nft_pipapo_match, rcu); 1613 1614 for_each_possible_cpu(i) 1615 kfree(*per_cpu_ptr(m->scratch, i)); 1616 1617 #ifdef NFT_PIPAPO_ALIGN 1618 free_percpu(m->scratch_aligned); 1619 #endif 1620 free_percpu(m->scratch); 1621 1622 pipapo_free_fields(m); 1623 1624 kfree(m); 1625 } 1626 1627 /** 1628 * pipapo_commit() - Replace lookup data with current working copy 1629 * @set: nftables API set representation 1630 * 1631 * While at it, check if we should perform garbage collection on the working 1632 * copy before committing it for lookup, and don't replace the table if the 1633 * working copy doesn't have pending changes. 1634 * 1635 * We also need to create a new working copy for subsequent insertions and 1636 * deletions. 1637 */ 1638 static void pipapo_commit(const struct nft_set *set) 1639 { 1640 struct nft_pipapo *priv = nft_set_priv(set); 1641 struct nft_pipapo_match *new_clone, *old; 1642 1643 if (time_after_eq(jiffies, priv->last_gc + nft_set_gc_interval(set))) 1644 pipapo_gc(set, priv->clone); 1645 1646 if (!priv->dirty) 1647 return; 1648 1649 new_clone = pipapo_clone(priv->clone); 1650 if (IS_ERR(new_clone)) 1651 return; 1652 1653 priv->dirty = false; 1654 1655 old = rcu_access_pointer(priv->match); 1656 rcu_assign_pointer(priv->match, priv->clone); 1657 if (old) 1658 call_rcu(&old->rcu, pipapo_reclaim_match); 1659 1660 priv->clone = new_clone; 1661 } 1662 1663 /** 1664 * nft_pipapo_activate() - Mark element reference as active given key, commit 1665 * @net: Network namespace 1666 * @set: nftables API set representation 1667 * @elem: nftables API element representation containing key data 1668 * 1669 * On insertion, elements are added to a copy of the matching data currently 1670 * in use for lookups, and not directly inserted into current lookup data, so 1671 * we'll take care of that by calling pipapo_commit() here. Both 1672 * nft_pipapo_insert() and nft_pipapo_activate() are called once for each 1673 * element, hence we can't purpose either one as a real commit operation. 1674 */ 1675 static void nft_pipapo_activate(const struct net *net, 1676 const struct nft_set *set, 1677 const struct nft_set_elem *elem) 1678 { 1679 struct nft_pipapo_elem *e; 1680 1681 e = pipapo_get(net, set, (const u8 *)elem->key.val.data, 0); 1682 if (IS_ERR(e)) 1683 return; 1684 1685 nft_set_elem_change_active(net, set, &e->ext); 1686 nft_set_elem_clear_busy(&e->ext); 1687 1688 pipapo_commit(set); 1689 } 1690 1691 /** 1692 * pipapo_deactivate() - Check that element is in set, mark as inactive 1693 * @net: Network namespace 1694 * @set: nftables API set representation 1695 * @data: Input key data 1696 * @ext: nftables API extension pointer, used to check for end element 1697 * 1698 * This is a convenience function that can be called from both 1699 * nft_pipapo_deactivate() and nft_pipapo_flush(), as they are in fact the same 1700 * operation. 1701 * 1702 * Return: deactivated element if found, NULL otherwise. 1703 */ 1704 static void *pipapo_deactivate(const struct net *net, const struct nft_set *set, 1705 const u8 *data, const struct nft_set_ext *ext) 1706 { 1707 struct nft_pipapo_elem *e; 1708 1709 e = pipapo_get(net, set, data, nft_genmask_next(net)); 1710 if (IS_ERR(e)) 1711 return NULL; 1712 1713 nft_set_elem_change_active(net, set, &e->ext); 1714 1715 return e; 1716 } 1717 1718 /** 1719 * nft_pipapo_deactivate() - Call pipapo_deactivate() to make element inactive 1720 * @net: Network namespace 1721 * @set: nftables API set representation 1722 * @elem: nftables API element representation containing key data 1723 * 1724 * Return: deactivated element if found, NULL otherwise. 1725 */ 1726 static void *nft_pipapo_deactivate(const struct net *net, 1727 const struct nft_set *set, 1728 const struct nft_set_elem *elem) 1729 { 1730 const struct nft_set_ext *ext = nft_set_elem_ext(set, elem->priv); 1731 1732 return pipapo_deactivate(net, set, (const u8 *)elem->key.val.data, ext); 1733 } 1734 1735 /** 1736 * nft_pipapo_flush() - Call pipapo_deactivate() to make element inactive 1737 * @net: Network namespace 1738 * @set: nftables API set representation 1739 * @elem: nftables API element representation containing key data 1740 * 1741 * This is functionally the same as nft_pipapo_deactivate(), with a slightly 1742 * different interface, and it's also called once for each element in a set 1743 * being flushed, so we can't implement, strictly speaking, a flush operation, 1744 * which would otherwise be as simple as allocating an empty copy of the 1745 * matching data. 1746 * 1747 * Note that we could in theory do that, mark the set as flushed, and ignore 1748 * subsequent calls, but we would leak all the elements after the first one, 1749 * because they wouldn't then be freed as result of API calls. 1750 * 1751 * Return: true if element was found and deactivated. 1752 */ 1753 static bool nft_pipapo_flush(const struct net *net, const struct nft_set *set, 1754 void *elem) 1755 { 1756 struct nft_pipapo_elem *e = elem; 1757 1758 return pipapo_deactivate(net, set, (const u8 *)nft_set_ext_key(&e->ext), 1759 &e->ext); 1760 } 1761 1762 /** 1763 * pipapo_get_boundaries() - Get byte interval for associated rules 1764 * @f: Field including lookup table 1765 * @first_rule: First rule (lowest index) 1766 * @rule_count: Number of associated rules 1767 * @left: Byte expression for left boundary (start of range) 1768 * @right: Byte expression for right boundary (end of range) 1769 * 1770 * Given the first rule and amount of rules that originated from the same entry, 1771 * build the original range associated with the entry, and calculate the length 1772 * of the originating netmask. 1773 * 1774 * In pictures: 1775 * 1776 * bucket 1777 * group 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1778 * 0 1,2 1779 * 1 1,2 1780 * 2 1,2 1781 * 3 1,2 1782 * 4 1,2 1783 * 5 1 2 1784 * 6 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1785 * 7 1,2 1,2 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1786 * 1787 * this is the lookup table corresponding to the IPv4 range 1788 * 192.168.1.0-192.168.2.1, which was expanded to the two composing netmasks, 1789 * rule #1: 192.168.1.0/24, and rule #2: 192.168.2.0/31. 1790 * 1791 * This function fills @left and @right with the byte values of the leftmost 1792 * and rightmost bucket indices for the lowest and highest rule indices, 1793 * respectively. If @first_rule is 1 and @rule_count is 2, we obtain, in 1794 * nibbles: 1795 * left: < 12, 0, 10, 8, 0, 1, 0, 0 > 1796 * right: < 12, 0, 10, 8, 0, 2, 2, 1 > 1797 * corresponding to bytes: 1798 * left: < 192, 168, 1, 0 > 1799 * right: < 192, 168, 2, 1 > 1800 * with mask length irrelevant here, unused on return, as the range is already 1801 * defined by its start and end points. The mask length is relevant for a single 1802 * ranged entry instead: if @first_rule is 1 and @rule_count is 1, we ignore 1803 * rule 2 above: @left becomes < 192, 168, 1, 0 >, @right becomes 1804 * < 192, 168, 1, 255 >, and the mask length, calculated from the distances 1805 * between leftmost and rightmost bucket indices for each group, would be 24. 1806 * 1807 * Return: mask length, in bits. 1808 */ 1809 static int pipapo_get_boundaries(struct nft_pipapo_field *f, int first_rule, 1810 int rule_count, u8 *left, u8 *right) 1811 { 1812 int g, mask_len = 0, bit_offset = 0; 1813 u8 *l = left, *r = right; 1814 1815 for (g = 0; g < f->groups; g++) { 1816 int b, x0, x1; 1817 1818 x0 = -1; 1819 x1 = -1; 1820 for (b = 0; b < NFT_PIPAPO_BUCKETS(f->bb); b++) { 1821 unsigned long *pos; 1822 1823 pos = NFT_PIPAPO_LT_ALIGN(f->lt) + 1824 (g * NFT_PIPAPO_BUCKETS(f->bb) + b) * f->bsize; 1825 if (test_bit(first_rule, pos) && x0 == -1) 1826 x0 = b; 1827 if (test_bit(first_rule + rule_count - 1, pos)) 1828 x1 = b; 1829 } 1830 1831 *l |= x0 << (BITS_PER_BYTE - f->bb - bit_offset); 1832 *r |= x1 << (BITS_PER_BYTE - f->bb - bit_offset); 1833 1834 bit_offset += f->bb; 1835 if (bit_offset >= BITS_PER_BYTE) { 1836 bit_offset %= BITS_PER_BYTE; 1837 l++; 1838 r++; 1839 } 1840 1841 if (x1 - x0 == 0) 1842 mask_len += 4; 1843 else if (x1 - x0 == 1) 1844 mask_len += 3; 1845 else if (x1 - x0 == 3) 1846 mask_len += 2; 1847 else if (x1 - x0 == 7) 1848 mask_len += 1; 1849 } 1850 1851 return mask_len; 1852 } 1853 1854 /** 1855 * pipapo_match_field() - Match rules against byte ranges 1856 * @f: Field including the lookup table 1857 * @first_rule: First of associated rules originating from same entry 1858 * @rule_count: Amount of associated rules 1859 * @start: Start of range to be matched 1860 * @end: End of range to be matched 1861 * 1862 * Return: true on match, false otherwise. 1863 */ 1864 static bool pipapo_match_field(struct nft_pipapo_field *f, 1865 int first_rule, int rule_count, 1866 const u8 *start, const u8 *end) 1867 { 1868 u8 right[NFT_PIPAPO_MAX_BYTES] = { 0 }; 1869 u8 left[NFT_PIPAPO_MAX_BYTES] = { 0 }; 1870 1871 pipapo_get_boundaries(f, first_rule, rule_count, left, right); 1872 1873 return !memcmp(start, left, 1874 f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)) && 1875 !memcmp(end, right, f->groups / NFT_PIPAPO_GROUPS_PER_BYTE(f)); 1876 } 1877 1878 /** 1879 * nft_pipapo_remove() - Remove element given key, commit 1880 * @net: Network namespace 1881 * @set: nftables API set representation 1882 * @elem: nftables API element representation containing key data 1883 * 1884 * Similarly to nft_pipapo_activate(), this is used as commit operation by the 1885 * API, but it's called once per element in the pending transaction, so we can't 1886 * implement this as a single commit operation. Closest we can get is to remove 1887 * the matched element here, if any, and commit the updated matching data. 1888 */ 1889 static void nft_pipapo_remove(const struct net *net, const struct nft_set *set, 1890 const struct nft_set_elem *elem) 1891 { 1892 struct nft_pipapo *priv = nft_set_priv(set); 1893 struct nft_pipapo_match *m = priv->clone; 1894 struct nft_pipapo_elem *e = elem->priv; 1895 int rules_f0, first_rule = 0; 1896 const u8 *data; 1897 1898 data = (const u8 *)nft_set_ext_key(&e->ext); 1899 1900 e = pipapo_get(net, set, data, 0); 1901 if (IS_ERR(e)) 1902 return; 1903 1904 while ((rules_f0 = pipapo_rules_same_key(m->f, first_rule))) { 1905 union nft_pipapo_map_bucket rulemap[NFT_PIPAPO_MAX_FIELDS]; 1906 const u8 *match_start, *match_end; 1907 struct nft_pipapo_field *f; 1908 int i, start, rules_fx; 1909 1910 match_start = data; 1911 match_end = (const u8 *)nft_set_ext_key_end(&e->ext)->data; 1912 1913 start = first_rule; 1914 rules_fx = rules_f0; 1915 1916 nft_pipapo_for_each_field(f, i, m) { 1917 if (!pipapo_match_field(f, start, rules_fx, 1918 match_start, match_end)) 1919 break; 1920 1921 rulemap[i].to = start; 1922 rulemap[i].n = rules_fx; 1923 1924 rules_fx = f->mt[start].n; 1925 start = f->mt[start].to; 1926 1927 match_start += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1928 match_end += NFT_PIPAPO_GROUPS_PADDED_SIZE(f); 1929 } 1930 1931 if (i == m->field_count) { 1932 priv->dirty = true; 1933 pipapo_drop(m, rulemap); 1934 pipapo_commit(set); 1935 return; 1936 } 1937 1938 first_rule += rules_f0; 1939 } 1940 } 1941 1942 /** 1943 * nft_pipapo_walk() - Walk over elements 1944 * @ctx: nftables API context 1945 * @set: nftables API set representation 1946 * @iter: Iterator 1947 * 1948 * As elements are referenced in the mapping array for the last field, directly 1949 * scan that array: there's no need to follow rule mappings from the first 1950 * field. 1951 */ 1952 static void nft_pipapo_walk(const struct nft_ctx *ctx, struct nft_set *set, 1953 struct nft_set_iter *iter) 1954 { 1955 struct nft_pipapo *priv = nft_set_priv(set); 1956 struct nft_pipapo_match *m; 1957 struct nft_pipapo_field *f; 1958 int i, r; 1959 1960 rcu_read_lock(); 1961 m = rcu_dereference(priv->match); 1962 1963 if (unlikely(!m)) 1964 goto out; 1965 1966 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) 1967 ; 1968 1969 for (r = 0; r < f->rules; r++) { 1970 struct nft_pipapo_elem *e; 1971 struct nft_set_elem elem; 1972 1973 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e) 1974 continue; 1975 1976 if (iter->count < iter->skip) 1977 goto cont; 1978 1979 e = f->mt[r].e; 1980 if (nft_set_elem_expired(&e->ext)) 1981 goto cont; 1982 1983 elem.priv = e; 1984 1985 iter->err = iter->fn(ctx, set, iter, &elem); 1986 if (iter->err < 0) 1987 goto out; 1988 1989 cont: 1990 iter->count++; 1991 } 1992 1993 out: 1994 rcu_read_unlock(); 1995 } 1996 1997 /** 1998 * nft_pipapo_privsize() - Return the size of private data for the set 1999 * @nla: netlink attributes, ignored as size doesn't depend on them 2000 * @desc: Set description, ignored as size doesn't depend on it 2001 * 2002 * Return: size of private data for this set implementation, in bytes 2003 */ 2004 static u64 nft_pipapo_privsize(const struct nlattr * const nla[], 2005 const struct nft_set_desc *desc) 2006 { 2007 return sizeof(struct nft_pipapo); 2008 } 2009 2010 /** 2011 * nft_pipapo_estimate() - Set size, space and lookup complexity 2012 * @desc: Set description, element count and field description used 2013 * @features: Flags: NFT_SET_INTERVAL needs to be there 2014 * @est: Storage for estimation data 2015 * 2016 * Return: true if set description is compatible, false otherwise 2017 */ 2018 static bool nft_pipapo_estimate(const struct nft_set_desc *desc, u32 features, 2019 struct nft_set_estimate *est) 2020 { 2021 if (!(features & NFT_SET_INTERVAL) || 2022 desc->field_count < NFT_PIPAPO_MIN_FIELDS) 2023 return false; 2024 2025 est->size = pipapo_estimate_size(desc); 2026 if (!est->size) 2027 return false; 2028 2029 est->lookup = NFT_SET_CLASS_O_LOG_N; 2030 2031 est->space = NFT_SET_CLASS_O_N; 2032 2033 return true; 2034 } 2035 2036 /** 2037 * nft_pipapo_init() - Initialise data for a set instance 2038 * @set: nftables API set representation 2039 * @desc: Set description 2040 * @nla: netlink attributes 2041 * 2042 * Validate number and size of fields passed as NFTA_SET_DESC_CONCAT netlink 2043 * attributes, initialise internal set parameters, current instance of matching 2044 * data and a copy for subsequent insertions. 2045 * 2046 * Return: 0 on success, negative error code on failure. 2047 */ 2048 static int nft_pipapo_init(const struct nft_set *set, 2049 const struct nft_set_desc *desc, 2050 const struct nlattr * const nla[]) 2051 { 2052 struct nft_pipapo *priv = nft_set_priv(set); 2053 struct nft_pipapo_match *m; 2054 struct nft_pipapo_field *f; 2055 int err, i, field_count; 2056 2057 field_count = desc->field_count ? : 1; 2058 2059 if (field_count > NFT_PIPAPO_MAX_FIELDS) 2060 return -EINVAL; 2061 2062 m = kmalloc(sizeof(*priv->match) + sizeof(*f) * field_count, 2063 GFP_KERNEL); 2064 if (!m) 2065 return -ENOMEM; 2066 2067 m->field_count = field_count; 2068 m->bsize_max = 0; 2069 2070 m->scratch = alloc_percpu(unsigned long *); 2071 if (!m->scratch) { 2072 err = -ENOMEM; 2073 goto out_scratch; 2074 } 2075 for_each_possible_cpu(i) 2076 *per_cpu_ptr(m->scratch, i) = NULL; 2077 2078 #ifdef NFT_PIPAPO_ALIGN 2079 m->scratch_aligned = alloc_percpu(unsigned long *); 2080 if (!m->scratch_aligned) { 2081 err = -ENOMEM; 2082 goto out_free; 2083 } 2084 for_each_possible_cpu(i) 2085 *per_cpu_ptr(m->scratch_aligned, i) = NULL; 2086 #endif 2087 2088 rcu_head_init(&m->rcu); 2089 2090 nft_pipapo_for_each_field(f, i, m) { 2091 int len = desc->field_len[i] ? : set->klen; 2092 2093 f->bb = NFT_PIPAPO_GROUP_BITS_INIT; 2094 f->groups = len * NFT_PIPAPO_GROUPS_PER_BYTE(f); 2095 2096 priv->width += round_up(len, sizeof(u32)); 2097 2098 f->bsize = 0; 2099 f->rules = 0; 2100 NFT_PIPAPO_LT_ASSIGN(f, NULL); 2101 f->mt = NULL; 2102 } 2103 2104 /* Create an initial clone of matching data for next insertion */ 2105 priv->clone = pipapo_clone(m); 2106 if (IS_ERR(priv->clone)) { 2107 err = PTR_ERR(priv->clone); 2108 goto out_free; 2109 } 2110 2111 priv->dirty = false; 2112 2113 rcu_assign_pointer(priv->match, m); 2114 2115 return 0; 2116 2117 out_free: 2118 #ifdef NFT_PIPAPO_ALIGN 2119 free_percpu(m->scratch_aligned); 2120 #endif 2121 free_percpu(m->scratch); 2122 out_scratch: 2123 kfree(m); 2124 2125 return err; 2126 } 2127 2128 /** 2129 * nft_set_pipapo_match_destroy() - Destroy elements from key mapping array 2130 * @set: nftables API set representation 2131 * @m: matching data pointing to key mapping array 2132 */ 2133 static void nft_set_pipapo_match_destroy(const struct nft_set *set, 2134 struct nft_pipapo_match *m) 2135 { 2136 struct nft_pipapo_field *f; 2137 int i, r; 2138 2139 for (i = 0, f = m->f; i < m->field_count - 1; i++, f++) 2140 ; 2141 2142 for (r = 0; r < f->rules; r++) { 2143 struct nft_pipapo_elem *e; 2144 2145 if (r < f->rules - 1 && f->mt[r + 1].e == f->mt[r].e) 2146 continue; 2147 2148 e = f->mt[r].e; 2149 2150 nft_set_elem_destroy(set, e, true); 2151 } 2152 } 2153 2154 /** 2155 * nft_pipapo_destroy() - Free private data for set and all committed elements 2156 * @set: nftables API set representation 2157 */ 2158 static void nft_pipapo_destroy(const struct nft_set *set) 2159 { 2160 struct nft_pipapo *priv = nft_set_priv(set); 2161 struct nft_pipapo_match *m; 2162 int cpu; 2163 2164 m = rcu_dereference_protected(priv->match, true); 2165 if (m) { 2166 rcu_barrier(); 2167 2168 nft_set_pipapo_match_destroy(set, m); 2169 2170 #ifdef NFT_PIPAPO_ALIGN 2171 free_percpu(m->scratch_aligned); 2172 #endif 2173 for_each_possible_cpu(cpu) 2174 kfree(*per_cpu_ptr(m->scratch, cpu)); 2175 free_percpu(m->scratch); 2176 pipapo_free_fields(m); 2177 kfree(m); 2178 priv->match = NULL; 2179 } 2180 2181 if (priv->clone) { 2182 m = priv->clone; 2183 2184 if (priv->dirty) 2185 nft_set_pipapo_match_destroy(set, m); 2186 2187 #ifdef NFT_PIPAPO_ALIGN 2188 free_percpu(priv->clone->scratch_aligned); 2189 #endif 2190 for_each_possible_cpu(cpu) 2191 kfree(*per_cpu_ptr(priv->clone->scratch, cpu)); 2192 free_percpu(priv->clone->scratch); 2193 2194 pipapo_free_fields(priv->clone); 2195 kfree(priv->clone); 2196 priv->clone = NULL; 2197 } 2198 } 2199 2200 /** 2201 * nft_pipapo_gc_init() - Initialise garbage collection 2202 * @set: nftables API set representation 2203 * 2204 * Instead of actually setting up a periodic work for garbage collection, as 2205 * this operation requires a swap of matching data with the working copy, we'll 2206 * do that opportunistically with other commit operations if the interval is 2207 * elapsed, so we just need to set the current jiffies timestamp here. 2208 */ 2209 static void nft_pipapo_gc_init(const struct nft_set *set) 2210 { 2211 struct nft_pipapo *priv = nft_set_priv(set); 2212 2213 priv->last_gc = jiffies; 2214 } 2215 2216 const struct nft_set_type nft_set_pipapo_type = { 2217 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | 2218 NFT_SET_TIMEOUT, 2219 .ops = { 2220 .lookup = nft_pipapo_lookup, 2221 .insert = nft_pipapo_insert, 2222 .activate = nft_pipapo_activate, 2223 .deactivate = nft_pipapo_deactivate, 2224 .flush = nft_pipapo_flush, 2225 .remove = nft_pipapo_remove, 2226 .walk = nft_pipapo_walk, 2227 .get = nft_pipapo_get, 2228 .privsize = nft_pipapo_privsize, 2229 .estimate = nft_pipapo_estimate, 2230 .init = nft_pipapo_init, 2231 .destroy = nft_pipapo_destroy, 2232 .gc_init = nft_pipapo_gc_init, 2233 .elemsize = offsetof(struct nft_pipapo_elem, ext), 2234 }, 2235 }; 2236 2237 #if defined(CONFIG_X86_64) && !defined(CONFIG_UML) 2238 const struct nft_set_type nft_set_pipapo_avx2_type = { 2239 .features = NFT_SET_INTERVAL | NFT_SET_MAP | NFT_SET_OBJECT | 2240 NFT_SET_TIMEOUT, 2241 .ops = { 2242 .lookup = nft_pipapo_avx2_lookup, 2243 .insert = nft_pipapo_insert, 2244 .activate = nft_pipapo_activate, 2245 .deactivate = nft_pipapo_deactivate, 2246 .flush = nft_pipapo_flush, 2247 .remove = nft_pipapo_remove, 2248 .walk = nft_pipapo_walk, 2249 .get = nft_pipapo_get, 2250 .privsize = nft_pipapo_privsize, 2251 .estimate = nft_pipapo_avx2_estimate, 2252 .init = nft_pipapo_init, 2253 .destroy = nft_pipapo_destroy, 2254 .gc_init = nft_pipapo_gc_init, 2255 .elemsize = offsetof(struct nft_pipapo_elem, ext), 2256 }, 2257 }; 2258 #endif 2259