1// SPDX-License-Identifier: GPL-2.0-only 2/* 3 * Copyright (c) 2007-2014 Nicira, Inc. 4 */ 5 6#include "flow.h" 7#include "datapath.h" 8#include "flow_netlink.h" 9#include <linux/uaccess.h> 10#include <linux/netdevice.h> 11#include <linux/etherdevice.h> 12#include <linux/if_ether.h> 13#include <linux/if_vlan.h> 14#include <net/llc_pdu.h> 15#include <linux/kernel.h> 16#include <linux/jhash.h> 17#include <linux/jiffies.h> 18#include <linux/llc.h> 19#include <linux/module.h> 20#include <linux/in.h> 21#include <linux/rcupdate.h> 22#include <linux/cpumask.h> 23#include <linux/if_arp.h> 24#include <linux/ip.h> 25#include <linux/ipv6.h> 26#include <linux/sctp.h> 27#include <linux/tcp.h> 28#include <linux/udp.h> 29#include <linux/icmp.h> 30#include <linux/icmpv6.h> 31#include <linux/rculist.h> 32#include <linux/sort.h> 33#include <net/ip.h> 34#include <net/ipv6.h> 35#include <net/ndisc.h> 36 37#define TBL_MIN_BUCKETS 1024 38#define MASK_ARRAY_SIZE_MIN 16 39#define REHASH_INTERVAL (10 * 60 * HZ) 40 41#define MC_DEFAULT_HASH_ENTRIES 256 42#define MC_HASH_SHIFT 8 43#define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT) 44 45static struct kmem_cache *flow_cache; 46struct kmem_cache *flow_stats_cache __read_mostly; 47 48static u16 range_n_bytes(const struct sw_flow_key_range *range) 49{ 50 return range->end - range->start; 51} 52 53void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src, 54 bool full, const struct sw_flow_mask *mask) 55{ 56 int start = full ? 0 : mask->range.start; 57 int len = full ? sizeof *dst : range_n_bytes(&mask->range); 58 const long *m = (const long *)((const u8 *)&mask->key + start); 59 const long *s = (const long *)((const u8 *)src + start); 60 long *d = (long *)((u8 *)dst + start); 61 int i; 62 63 /* If 'full' is true then all of 'dst' is fully initialized. Otherwise, 64 * if 'full' is false the memory outside of the 'mask->range' is left 65 * uninitialized. This can be used as an optimization when further 66 * operations on 'dst' only use contents within 'mask->range'. 67 */ 68 for (i = 0; i < len; i += sizeof(long)) 69 *d++ = *s++ & *m++; 70} 71 72struct sw_flow *ovs_flow_alloc(void) 73{ 74 struct sw_flow *flow; 75 struct sw_flow_stats *stats; 76 77 flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL); 78 if (!flow) 79 return ERR_PTR(-ENOMEM); 80 81 flow->stats_last_writer = -1; 82 83 /* Initialize the default stat node. */ 84 stats = kmem_cache_alloc_node(flow_stats_cache, 85 GFP_KERNEL | __GFP_ZERO, 86 node_online(0) ? 0 : NUMA_NO_NODE); 87 if (!stats) 88 goto err; 89 90 spin_lock_init(&stats->lock); 91 92 RCU_INIT_POINTER(flow->stats[0], stats); 93 94 cpumask_set_cpu(0, &flow->cpu_used_mask); 95 96 return flow; 97err: 98 kmem_cache_free(flow_cache, flow); 99 return ERR_PTR(-ENOMEM); 100} 101 102int ovs_flow_tbl_count(const struct flow_table *table) 103{ 104 return table->count; 105} 106 107static void flow_free(struct sw_flow *flow) 108{ 109 int cpu; 110 111 if (ovs_identifier_is_key(&flow->id)) 112 kfree(flow->id.unmasked_key); 113 if (flow->sf_acts) 114 ovs_nla_free_flow_actions((struct sw_flow_actions __force *) 115 flow->sf_acts); 116 /* We open code this to make sure cpu 0 is always considered */ 117 for (cpu = 0; cpu < nr_cpu_ids; 118 cpu = cpumask_next(cpu, &flow->cpu_used_mask)) { 119 if (flow->stats[cpu]) 120 kmem_cache_free(flow_stats_cache, 121 (struct sw_flow_stats __force *)flow->stats[cpu]); 122 } 123 124 kmem_cache_free(flow_cache, flow); 125} 126 127static void rcu_free_flow_callback(struct rcu_head *rcu) 128{ 129 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu); 130 131 flow_free(flow); 132} 133 134void ovs_flow_free(struct sw_flow *flow, bool deferred) 135{ 136 if (!flow) 137 return; 138 139 if (deferred) 140 call_rcu(&flow->rcu, rcu_free_flow_callback); 141 else 142 flow_free(flow); 143} 144 145static void __table_instance_destroy(struct table_instance *ti) 146{ 147 kvfree(ti->buckets); 148 kfree(ti); 149} 150 151static struct table_instance *table_instance_alloc(int new_size) 152{ 153 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL); 154 int i; 155 156 if (!ti) 157 return NULL; 158 159 ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head), 160 GFP_KERNEL); 161 if (!ti->buckets) { 162 kfree(ti); 163 return NULL; 164 } 165 166 for (i = 0; i < new_size; i++) 167 INIT_HLIST_HEAD(&ti->buckets[i]); 168 169 ti->n_buckets = new_size; 170 ti->node_ver = 0; 171 get_random_bytes(&ti->hash_seed, sizeof(u32)); 172 173 return ti; 174} 175 176static void __mask_array_destroy(struct mask_array *ma) 177{ 178 free_percpu(ma->masks_usage_stats); 179 kfree(ma); 180} 181 182static void mask_array_rcu_cb(struct rcu_head *rcu) 183{ 184 struct mask_array *ma = container_of(rcu, struct mask_array, rcu); 185 186 __mask_array_destroy(ma); 187} 188 189static void tbl_mask_array_reset_counters(struct mask_array *ma) 190{ 191 int i, cpu; 192 193 /* As the per CPU counters are not atomic we can not go ahead and 194 * reset them from another CPU. To be able to still have an approximate 195 * zero based counter we store the value at reset, and subtract it 196 * later when processing. 197 */ 198 for (i = 0; i < ma->max; i++) { 199 ma->masks_usage_zero_cntr[i] = 0; 200 201 for_each_possible_cpu(cpu) { 202 struct mask_array_stats *stats; 203 unsigned int start; 204 u64 counter; 205 206 stats = per_cpu_ptr(ma->masks_usage_stats, cpu); 207 do { 208 start = u64_stats_fetch_begin_irq(&stats->syncp); 209 counter = stats->usage_cntrs[i]; 210 } while (u64_stats_fetch_retry_irq(&stats->syncp, start)); 211 212 ma->masks_usage_zero_cntr[i] += counter; 213 } 214 } 215} 216 217static struct mask_array *tbl_mask_array_alloc(int size) 218{ 219 struct mask_array *new; 220 221 size = max(MASK_ARRAY_SIZE_MIN, size); 222 new = kzalloc(sizeof(struct mask_array) + 223 sizeof(struct sw_flow_mask *) * size + 224 sizeof(u64) * size, GFP_KERNEL); 225 if (!new) 226 return NULL; 227 228 new->masks_usage_zero_cntr = (u64 *)((u8 *)new + 229 sizeof(struct mask_array) + 230 sizeof(struct sw_flow_mask *) * 231 size); 232 233 new->masks_usage_stats = __alloc_percpu(sizeof(struct mask_array_stats) + 234 sizeof(u64) * size, 235 __alignof__(u64)); 236 if (!new->masks_usage_stats) { 237 kfree(new); 238 return NULL; 239 } 240 241 new->count = 0; 242 new->max = size; 243 244 return new; 245} 246 247static int tbl_mask_array_realloc(struct flow_table *tbl, int size) 248{ 249 struct mask_array *old; 250 struct mask_array *new; 251 252 new = tbl_mask_array_alloc(size); 253 if (!new) 254 return -ENOMEM; 255 256 old = ovsl_dereference(tbl->mask_array); 257 if (old) { 258 int i; 259 260 for (i = 0; i < old->max; i++) { 261 if (ovsl_dereference(old->masks[i])) 262 new->masks[new->count++] = old->masks[i]; 263 } 264 call_rcu(&old->rcu, mask_array_rcu_cb); 265 } 266 267 rcu_assign_pointer(tbl->mask_array, new); 268 269 return 0; 270} 271 272static int tbl_mask_array_add_mask(struct flow_table *tbl, 273 struct sw_flow_mask *new) 274{ 275 struct mask_array *ma = ovsl_dereference(tbl->mask_array); 276 int err, ma_count = READ_ONCE(ma->count); 277 278 if (ma_count >= ma->max) { 279 err = tbl_mask_array_realloc(tbl, ma->max + 280 MASK_ARRAY_SIZE_MIN); 281 if (err) 282 return err; 283 284 ma = ovsl_dereference(tbl->mask_array); 285 } else { 286 /* On every add or delete we need to reset the counters so 287 * every new mask gets a fair chance of being prioritized. 288 */ 289 tbl_mask_array_reset_counters(ma); 290 } 291 292 BUG_ON(ovsl_dereference(ma->masks[ma_count])); 293 294 rcu_assign_pointer(ma->masks[ma_count], new); 295 WRITE_ONCE(ma->count, ma_count + 1); 296 297 return 0; 298} 299 300static void tbl_mask_array_del_mask(struct flow_table *tbl, 301 struct sw_flow_mask *mask) 302{ 303 struct mask_array *ma = ovsl_dereference(tbl->mask_array); 304 int i, ma_count = READ_ONCE(ma->count); 305 306 /* Remove the deleted mask pointers from the array */ 307 for (i = 0; i < ma_count; i++) { 308 if (mask == ovsl_dereference(ma->masks[i])) 309 goto found; 310 } 311 312 BUG(); 313 return; 314 315found: 316 WRITE_ONCE(ma->count, ma_count - 1); 317 318 rcu_assign_pointer(ma->masks[i], ma->masks[ma_count - 1]); 319 RCU_INIT_POINTER(ma->masks[ma_count - 1], NULL); 320 321 kfree_rcu(mask, rcu); 322 323 /* Shrink the mask array if necessary. */ 324 if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) && 325 ma_count <= (ma->max / 3)) 326 tbl_mask_array_realloc(tbl, ma->max / 2); 327 else 328 tbl_mask_array_reset_counters(ma); 329 330} 331 332/* Remove 'mask' from the mask list, if it is not needed any more. */ 333static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask) 334{ 335 if (mask) { 336 /* ovs-lock is required to protect mask-refcount and 337 * mask list. 338 */ 339 ASSERT_OVSL(); 340 BUG_ON(!mask->ref_count); 341 mask->ref_count--; 342 343 if (!mask->ref_count) 344 tbl_mask_array_del_mask(tbl, mask); 345 } 346} 347 348static void __mask_cache_destroy(struct mask_cache *mc) 349{ 350 free_percpu(mc->mask_cache); 351 kfree(mc); 352} 353 354static void mask_cache_rcu_cb(struct rcu_head *rcu) 355{ 356 struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu); 357 358 __mask_cache_destroy(mc); 359} 360 361static struct mask_cache *tbl_mask_cache_alloc(u32 size) 362{ 363 struct mask_cache_entry __percpu *cache = NULL; 364 struct mask_cache *new; 365 366 /* Only allow size to be 0, or a power of 2, and does not exceed 367 * percpu allocation size. 368 */ 369 if ((!is_power_of_2(size) && size != 0) || 370 (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE) 371 return NULL; 372 373 new = kzalloc(sizeof(*new), GFP_KERNEL); 374 if (!new) 375 return NULL; 376 377 new->cache_size = size; 378 if (new->cache_size > 0) { 379 cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry), 380 new->cache_size), 381 __alignof__(struct mask_cache_entry)); 382 if (!cache) { 383 kfree(new); 384 return NULL; 385 } 386 } 387 388 new->mask_cache = cache; 389 return new; 390} 391int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size) 392{ 393 struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache); 394 struct mask_cache *new; 395 396 if (size == mc->cache_size) 397 return 0; 398 399 if ((!is_power_of_2(size) && size != 0) || 400 (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE) 401 return -EINVAL; 402 403 new = tbl_mask_cache_alloc(size); 404 if (!new) 405 return -ENOMEM; 406 407 rcu_assign_pointer(table->mask_cache, new); 408 call_rcu(&mc->rcu, mask_cache_rcu_cb); 409 410 return 0; 411} 412 413int ovs_flow_tbl_init(struct flow_table *table) 414{ 415 struct table_instance *ti, *ufid_ti; 416 struct mask_cache *mc; 417 struct mask_array *ma; 418 419 mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES); 420 if (!mc) 421 return -ENOMEM; 422 423 ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN); 424 if (!ma) 425 goto free_mask_cache; 426 427 ti = table_instance_alloc(TBL_MIN_BUCKETS); 428 if (!ti) 429 goto free_mask_array; 430 431 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 432 if (!ufid_ti) 433 goto free_ti; 434 435 rcu_assign_pointer(table->ti, ti); 436 rcu_assign_pointer(table->ufid_ti, ufid_ti); 437 rcu_assign_pointer(table->mask_array, ma); 438 rcu_assign_pointer(table->mask_cache, mc); 439 table->last_rehash = jiffies; 440 table->count = 0; 441 table->ufid_count = 0; 442 return 0; 443 444free_ti: 445 __table_instance_destroy(ti); 446free_mask_array: 447 __mask_array_destroy(ma); 448free_mask_cache: 449 __mask_cache_destroy(mc); 450 return -ENOMEM; 451} 452 453static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu) 454{ 455 struct table_instance *ti; 456 457 ti = container_of(rcu, struct table_instance, rcu); 458 __table_instance_destroy(ti); 459} 460 461static void table_instance_flow_free(struct flow_table *table, 462 struct table_instance *ti, 463 struct table_instance *ufid_ti, 464 struct sw_flow *flow) 465{ 466 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]); 467 table->count--; 468 469 if (ovs_identifier_is_ufid(&flow->id)) { 470 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]); 471 table->ufid_count--; 472 } 473 474 flow_mask_remove(table, flow->mask); 475} 476 477/* Must be called with OVS mutex held. */ 478void table_instance_flow_flush(struct flow_table *table, 479 struct table_instance *ti, 480 struct table_instance *ufid_ti) 481{ 482 int i; 483 484 for (i = 0; i < ti->n_buckets; i++) { 485 struct hlist_head *head = &ti->buckets[i]; 486 struct hlist_node *n; 487 struct sw_flow *flow; 488 489 hlist_for_each_entry_safe(flow, n, head, 490 flow_table.node[ti->node_ver]) { 491 492 table_instance_flow_free(table, ti, ufid_ti, 493 flow); 494 ovs_flow_free(flow, true); 495 } 496 } 497 498 if (WARN_ON(table->count != 0 || 499 table->ufid_count != 0)) { 500 table->count = 0; 501 table->ufid_count = 0; 502 } 503} 504 505static void table_instance_destroy(struct table_instance *ti, 506 struct table_instance *ufid_ti) 507{ 508 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 509 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); 510} 511 512/* No need for locking this function is called from RCU callback or 513 * error path. 514 */ 515void ovs_flow_tbl_destroy(struct flow_table *table) 516{ 517 struct table_instance *ti = rcu_dereference_raw(table->ti); 518 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti); 519 struct mask_cache *mc = rcu_dereference_raw(table->mask_cache); 520 struct mask_array *ma = rcu_dereference_raw(table->mask_array); 521 522 call_rcu(&mc->rcu, mask_cache_rcu_cb); 523 call_rcu(&ma->rcu, mask_array_rcu_cb); 524 table_instance_destroy(ti, ufid_ti); 525} 526 527struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti, 528 u32 *bucket, u32 *last) 529{ 530 struct sw_flow *flow; 531 struct hlist_head *head; 532 int ver; 533 int i; 534 535 ver = ti->node_ver; 536 while (*bucket < ti->n_buckets) { 537 i = 0; 538 head = &ti->buckets[*bucket]; 539 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) { 540 if (i < *last) { 541 i++; 542 continue; 543 } 544 *last = i + 1; 545 return flow; 546 } 547 (*bucket)++; 548 *last = 0; 549 } 550 551 return NULL; 552} 553 554static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash) 555{ 556 hash = jhash_1word(hash, ti->hash_seed); 557 return &ti->buckets[hash & (ti->n_buckets - 1)]; 558} 559 560static void table_instance_insert(struct table_instance *ti, 561 struct sw_flow *flow) 562{ 563 struct hlist_head *head; 564 565 head = find_bucket(ti, flow->flow_table.hash); 566 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head); 567} 568 569static void ufid_table_instance_insert(struct table_instance *ti, 570 struct sw_flow *flow) 571{ 572 struct hlist_head *head; 573 574 head = find_bucket(ti, flow->ufid_table.hash); 575 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head); 576} 577 578static void flow_table_copy_flows(struct table_instance *old, 579 struct table_instance *new, bool ufid) 580{ 581 int old_ver; 582 int i; 583 584 old_ver = old->node_ver; 585 new->node_ver = !old_ver; 586 587 /* Insert in new table. */ 588 for (i = 0; i < old->n_buckets; i++) { 589 struct sw_flow *flow; 590 struct hlist_head *head = &old->buckets[i]; 591 592 if (ufid) 593 hlist_for_each_entry_rcu(flow, head, 594 ufid_table.node[old_ver], 595 lockdep_ovsl_is_held()) 596 ufid_table_instance_insert(new, flow); 597 else 598 hlist_for_each_entry_rcu(flow, head, 599 flow_table.node[old_ver], 600 lockdep_ovsl_is_held()) 601 table_instance_insert(new, flow); 602 } 603} 604 605static struct table_instance *table_instance_rehash(struct table_instance *ti, 606 int n_buckets, bool ufid) 607{ 608 struct table_instance *new_ti; 609 610 new_ti = table_instance_alloc(n_buckets); 611 if (!new_ti) 612 return NULL; 613 614 flow_table_copy_flows(ti, new_ti, ufid); 615 616 return new_ti; 617} 618 619int ovs_flow_tbl_flush(struct flow_table *flow_table) 620{ 621 struct table_instance *old_ti, *new_ti; 622 struct table_instance *old_ufid_ti, *new_ufid_ti; 623 624 new_ti = table_instance_alloc(TBL_MIN_BUCKETS); 625 if (!new_ti) 626 return -ENOMEM; 627 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 628 if (!new_ufid_ti) 629 goto err_free_ti; 630 631 old_ti = ovsl_dereference(flow_table->ti); 632 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti); 633 634 rcu_assign_pointer(flow_table->ti, new_ti); 635 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti); 636 flow_table->last_rehash = jiffies; 637 638 table_instance_flow_flush(flow_table, old_ti, old_ufid_ti); 639 table_instance_destroy(old_ti, old_ufid_ti); 640 return 0; 641 642err_free_ti: 643 __table_instance_destroy(new_ti); 644 return -ENOMEM; 645} 646 647static u32 flow_hash(const struct sw_flow_key *key, 648 const struct sw_flow_key_range *range) 649{ 650 const u32 *hash_key = (const u32 *)((const u8 *)key + range->start); 651 652 /* Make sure number of hash bytes are multiple of u32. */ 653 int hash_u32s = range_n_bytes(range) >> 2; 654 655 return jhash2(hash_key, hash_u32s, 0); 656} 657 658static int flow_key_start(const struct sw_flow_key *key) 659{ 660 if (key->tun_proto) 661 return 0; 662 else 663 return rounddown(offsetof(struct sw_flow_key, phy), 664 sizeof(long)); 665} 666 667static bool cmp_key(const struct sw_flow_key *key1, 668 const struct sw_flow_key *key2, 669 int key_start, int key_end) 670{ 671 const long *cp1 = (const long *)((const u8 *)key1 + key_start); 672 const long *cp2 = (const long *)((const u8 *)key2 + key_start); 673 long diffs = 0; 674 int i; 675 676 for (i = key_start; i < key_end; i += sizeof(long)) 677 diffs |= *cp1++ ^ *cp2++; 678 679 return diffs == 0; 680} 681 682static bool flow_cmp_masked_key(const struct sw_flow *flow, 683 const struct sw_flow_key *key, 684 const struct sw_flow_key_range *range) 685{ 686 return cmp_key(&flow->key, key, range->start, range->end); 687} 688 689static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow, 690 const struct sw_flow_match *match) 691{ 692 struct sw_flow_key *key = match->key; 693 int key_start = flow_key_start(key); 694 int key_end = match->range.end; 695 696 BUG_ON(ovs_identifier_is_ufid(&flow->id)); 697 return cmp_key(flow->id.unmasked_key, key, key_start, key_end); 698} 699 700static struct sw_flow *masked_flow_lookup(struct table_instance *ti, 701 const struct sw_flow_key *unmasked, 702 const struct sw_flow_mask *mask, 703 u32 *n_mask_hit) 704{ 705 struct sw_flow *flow; 706 struct hlist_head *head; 707 u32 hash; 708 struct sw_flow_key masked_key; 709 710 ovs_flow_mask_key(&masked_key, unmasked, false, mask); 711 hash = flow_hash(&masked_key, &mask->range); 712 head = find_bucket(ti, hash); 713 (*n_mask_hit)++; 714 715 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver], 716 lockdep_ovsl_is_held()) { 717 if (flow->mask == mask && flow->flow_table.hash == hash && 718 flow_cmp_masked_key(flow, &masked_key, &mask->range)) 719 return flow; 720 } 721 return NULL; 722} 723 724/* Flow lookup does full lookup on flow table. It starts with 725 * mask from index passed in *index. 726 * This function MUST be called with BH disabled due to the use 727 * of CPU specific variables. 728 */ 729static struct sw_flow *flow_lookup(struct flow_table *tbl, 730 struct table_instance *ti, 731 struct mask_array *ma, 732 const struct sw_flow_key *key, 733 u32 *n_mask_hit, 734 u32 *n_cache_hit, 735 u32 *index) 736{ 737 struct mask_array_stats *stats = this_cpu_ptr(ma->masks_usage_stats); 738 struct sw_flow *flow; 739 struct sw_flow_mask *mask; 740 int i; 741 742 if (likely(*index < ma->max)) { 743 mask = rcu_dereference_ovsl(ma->masks[*index]); 744 if (mask) { 745 flow = masked_flow_lookup(ti, key, mask, n_mask_hit); 746 if (flow) { 747 u64_stats_update_begin(&stats->syncp); 748 stats->usage_cntrs[*index]++; 749 u64_stats_update_end(&stats->syncp); 750 (*n_cache_hit)++; 751 return flow; 752 } 753 } 754 } 755 756 for (i = 0; i < ma->max; i++) { 757 758 if (i == *index) 759 continue; 760 761 mask = rcu_dereference_ovsl(ma->masks[i]); 762 if (unlikely(!mask)) 763 break; 764 765 flow = masked_flow_lookup(ti, key, mask, n_mask_hit); 766 if (flow) { /* Found */ 767 *index = i; 768 u64_stats_update_begin(&stats->syncp); 769 stats->usage_cntrs[*index]++; 770 u64_stats_update_end(&stats->syncp); 771 return flow; 772 } 773 } 774 775 return NULL; 776} 777 778/* 779 * mask_cache maps flow to probable mask. This cache is not tightly 780 * coupled cache, It means updates to mask list can result in inconsistent 781 * cache entry in mask cache. 782 * This is per cpu cache and is divided in MC_HASH_SEGS segments. 783 * In case of a hash collision the entry is hashed in next segment. 784 * */ 785struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl, 786 const struct sw_flow_key *key, 787 u32 skb_hash, 788 u32 *n_mask_hit, 789 u32 *n_cache_hit) 790{ 791 struct mask_cache *mc = rcu_dereference(tbl->mask_cache); 792 struct mask_array *ma = rcu_dereference(tbl->mask_array); 793 struct table_instance *ti = rcu_dereference(tbl->ti); 794 struct mask_cache_entry *entries, *ce; 795 struct sw_flow *flow; 796 u32 hash; 797 int seg; 798 799 *n_mask_hit = 0; 800 *n_cache_hit = 0; 801 if (unlikely(!skb_hash || mc->cache_size == 0)) { 802 u32 mask_index = 0; 803 u32 cache = 0; 804 805 return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache, 806 &mask_index); 807 } 808 809 /* Pre and post recirulation flows usually have the same skb_hash 810 * value. To avoid hash collisions, rehash the 'skb_hash' with 811 * 'recirc_id'. */ 812 if (key->recirc_id) 813 skb_hash = jhash_1word(skb_hash, key->recirc_id); 814 815 ce = NULL; 816 hash = skb_hash; 817 entries = this_cpu_ptr(mc->mask_cache); 818 819 /* Find the cache entry 'ce' to operate on. */ 820 for (seg = 0; seg < MC_HASH_SEGS; seg++) { 821 int index = hash & (mc->cache_size - 1); 822 struct mask_cache_entry *e; 823 824 e = &entries[index]; 825 if (e->skb_hash == skb_hash) { 826 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, 827 n_cache_hit, &e->mask_index); 828 if (!flow) 829 e->skb_hash = 0; 830 return flow; 831 } 832 833 if (!ce || e->skb_hash < ce->skb_hash) 834 ce = e; /* A better replacement cache candidate. */ 835 836 hash >>= MC_HASH_SHIFT; 837 } 838 839 /* Cache miss, do full lookup. */ 840 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit, 841 &ce->mask_index); 842 if (flow) 843 ce->skb_hash = skb_hash; 844 845 *n_cache_hit = 0; 846 return flow; 847} 848 849struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl, 850 const struct sw_flow_key *key) 851{ 852 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 853 struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array); 854 u32 __always_unused n_mask_hit; 855 u32 __always_unused n_cache_hit; 856 struct sw_flow *flow; 857 u32 index = 0; 858 859 /* This function gets called trough the netlink interface and therefore 860 * is preemptible. However, flow_lookup() function needs to be called 861 * with BH disabled due to CPU specific variables. 862 */ 863 local_bh_disable(); 864 flow = flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index); 865 local_bh_enable(); 866 return flow; 867} 868 869struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl, 870 const struct sw_flow_match *match) 871{ 872 struct mask_array *ma = ovsl_dereference(tbl->mask_array); 873 int i; 874 875 /* Always called under ovs-mutex. */ 876 for (i = 0; i < ma->max; i++) { 877 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 878 u32 __always_unused n_mask_hit; 879 struct sw_flow_mask *mask; 880 struct sw_flow *flow; 881 882 mask = ovsl_dereference(ma->masks[i]); 883 if (!mask) 884 continue; 885 886 flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit); 887 if (flow && ovs_identifier_is_key(&flow->id) && 888 ovs_flow_cmp_unmasked_key(flow, match)) { 889 return flow; 890 } 891 } 892 893 return NULL; 894} 895 896static u32 ufid_hash(const struct sw_flow_id *sfid) 897{ 898 return jhash(sfid->ufid, sfid->ufid_len, 0); 899} 900 901static bool ovs_flow_cmp_ufid(const struct sw_flow *flow, 902 const struct sw_flow_id *sfid) 903{ 904 if (flow->id.ufid_len != sfid->ufid_len) 905 return false; 906 907 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len); 908} 909 910bool ovs_flow_cmp(const struct sw_flow *flow, 911 const struct sw_flow_match *match) 912{ 913 if (ovs_identifier_is_ufid(&flow->id)) 914 return flow_cmp_masked_key(flow, match->key, &match->range); 915 916 return ovs_flow_cmp_unmasked_key(flow, match); 917} 918 919struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl, 920 const struct sw_flow_id *ufid) 921{ 922 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti); 923 struct sw_flow *flow; 924 struct hlist_head *head; 925 u32 hash; 926 927 hash = ufid_hash(ufid); 928 head = find_bucket(ti, hash); 929 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver], 930 lockdep_ovsl_is_held()) { 931 if (flow->ufid_table.hash == hash && 932 ovs_flow_cmp_ufid(flow, ufid)) 933 return flow; 934 } 935 return NULL; 936} 937 938int ovs_flow_tbl_num_masks(const struct flow_table *table) 939{ 940 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array); 941 return READ_ONCE(ma->count); 942} 943 944u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table) 945{ 946 struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache); 947 948 return READ_ONCE(mc->cache_size); 949} 950 951static struct table_instance *table_instance_expand(struct table_instance *ti, 952 bool ufid) 953{ 954 return table_instance_rehash(ti, ti->n_buckets * 2, ufid); 955} 956 957/* Must be called with OVS mutex held. */ 958void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow) 959{ 960 struct table_instance *ti = ovsl_dereference(table->ti); 961 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti); 962 963 BUG_ON(table->count == 0); 964 table_instance_flow_free(table, ti, ufid_ti, flow); 965} 966 967static struct sw_flow_mask *mask_alloc(void) 968{ 969 struct sw_flow_mask *mask; 970 971 mask = kmalloc(sizeof(*mask), GFP_KERNEL); 972 if (mask) 973 mask->ref_count = 1; 974 975 return mask; 976} 977 978static bool mask_equal(const struct sw_flow_mask *a, 979 const struct sw_flow_mask *b) 980{ 981 const u8 *a_ = (const u8 *)&a->key + a->range.start; 982 const u8 *b_ = (const u8 *)&b->key + b->range.start; 983 984 return (a->range.end == b->range.end) 985 && (a->range.start == b->range.start) 986 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0); 987} 988 989static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl, 990 const struct sw_flow_mask *mask) 991{ 992 struct mask_array *ma; 993 int i; 994 995 ma = ovsl_dereference(tbl->mask_array); 996 for (i = 0; i < ma->max; i++) { 997 struct sw_flow_mask *t; 998 t = ovsl_dereference(ma->masks[i]); 999 1000 if (t && mask_equal(mask, t)) 1001 return t; 1002 } 1003 1004 return NULL; 1005} 1006 1007/* Add 'mask' into the mask list, if it is not already there. */ 1008static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, 1009 const struct sw_flow_mask *new) 1010{ 1011 struct sw_flow_mask *mask; 1012 1013 mask = flow_mask_find(tbl, new); 1014 if (!mask) { 1015 /* Allocate a new mask if none exsits. */ 1016 mask = mask_alloc(); 1017 if (!mask) 1018 return -ENOMEM; 1019 mask->key = new->key; 1020 mask->range = new->range; 1021 1022 /* Add mask to mask-list. */ 1023 if (tbl_mask_array_add_mask(tbl, mask)) { 1024 kfree(mask); 1025 return -ENOMEM; 1026 } 1027 } else { 1028 BUG_ON(!mask->ref_count); 1029 mask->ref_count++; 1030 } 1031 1032 flow->mask = mask; 1033 return 0; 1034} 1035 1036/* Must be called with OVS mutex held. */ 1037static void flow_key_insert(struct flow_table *table, struct sw_flow *flow) 1038{ 1039 struct table_instance *new_ti = NULL; 1040 struct table_instance *ti; 1041 1042 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range); 1043 ti = ovsl_dereference(table->ti); 1044 table_instance_insert(ti, flow); 1045 table->count++; 1046 1047 /* Expand table, if necessary, to make room. */ 1048 if (table->count > ti->n_buckets) 1049 new_ti = table_instance_expand(ti, false); 1050 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL)) 1051 new_ti = table_instance_rehash(ti, ti->n_buckets, false); 1052 1053 if (new_ti) { 1054 rcu_assign_pointer(table->ti, new_ti); 1055 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 1056 table->last_rehash = jiffies; 1057 } 1058} 1059 1060/* Must be called with OVS mutex held. */ 1061static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow) 1062{ 1063 struct table_instance *ti; 1064 1065 flow->ufid_table.hash = ufid_hash(&flow->id); 1066 ti = ovsl_dereference(table->ufid_ti); 1067 ufid_table_instance_insert(ti, flow); 1068 table->ufid_count++; 1069 1070 /* Expand table, if necessary, to make room. */ 1071 if (table->ufid_count > ti->n_buckets) { 1072 struct table_instance *new_ti; 1073 1074 new_ti = table_instance_expand(ti, true); 1075 if (new_ti) { 1076 rcu_assign_pointer(table->ufid_ti, new_ti); 1077 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 1078 } 1079 } 1080} 1081 1082/* Must be called with OVS mutex held. */ 1083int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow, 1084 const struct sw_flow_mask *mask) 1085{ 1086 int err; 1087 1088 err = flow_mask_insert(table, flow, mask); 1089 if (err) 1090 return err; 1091 flow_key_insert(table, flow); 1092 if (ovs_identifier_is_ufid(&flow->id)) 1093 flow_ufid_insert(table, flow); 1094 1095 return 0; 1096} 1097 1098static int compare_mask_and_count(const void *a, const void *b) 1099{ 1100 const struct mask_count *mc_a = a; 1101 const struct mask_count *mc_b = b; 1102 1103 return (s64)mc_b->counter - (s64)mc_a->counter; 1104} 1105 1106/* Must be called with OVS mutex held. */ 1107void ovs_flow_masks_rebalance(struct flow_table *table) 1108{ 1109 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array); 1110 struct mask_count *masks_and_count; 1111 struct mask_array *new; 1112 int masks_entries = 0; 1113 int i; 1114 1115 /* Build array of all current entries with use counters. */ 1116 masks_and_count = kmalloc_array(ma->max, sizeof(*masks_and_count), 1117 GFP_KERNEL); 1118 if (!masks_and_count) 1119 return; 1120 1121 for (i = 0; i < ma->max; i++) { 1122 struct sw_flow_mask *mask; 1123 int cpu; 1124 1125 mask = rcu_dereference_ovsl(ma->masks[i]); 1126 if (unlikely(!mask)) 1127 break; 1128 1129 masks_and_count[i].index = i; 1130 masks_and_count[i].counter = 0; 1131 1132 for_each_possible_cpu(cpu) { 1133 struct mask_array_stats *stats; 1134 unsigned int start; 1135 u64 counter; 1136 1137 stats = per_cpu_ptr(ma->masks_usage_stats, cpu); 1138 do { 1139 start = u64_stats_fetch_begin_irq(&stats->syncp); 1140 counter = stats->usage_cntrs[i]; 1141 } while (u64_stats_fetch_retry_irq(&stats->syncp, 1142 start)); 1143 1144 masks_and_count[i].counter += counter; 1145 } 1146 1147 /* Subtract the zero count value. */ 1148 masks_and_count[i].counter -= ma->masks_usage_zero_cntr[i]; 1149 1150 /* Rather than calling tbl_mask_array_reset_counters() 1151 * below when no change is needed, do it inline here. 1152 */ 1153 ma->masks_usage_zero_cntr[i] += masks_and_count[i].counter; 1154 } 1155 1156 if (i == 0) 1157 goto free_mask_entries; 1158 1159 /* Sort the entries */ 1160 masks_entries = i; 1161 sort(masks_and_count, masks_entries, sizeof(*masks_and_count), 1162 compare_mask_and_count, NULL); 1163 1164 /* If the order is the same, nothing to do... */ 1165 for (i = 0; i < masks_entries; i++) { 1166 if (i != masks_and_count[i].index) 1167 break; 1168 } 1169 if (i == masks_entries) 1170 goto free_mask_entries; 1171 1172 /* Rebuilt the new list in order of usage. */ 1173 new = tbl_mask_array_alloc(ma->max); 1174 if (!new) 1175 goto free_mask_entries; 1176 1177 for (i = 0; i < masks_entries; i++) { 1178 int index = masks_and_count[i].index; 1179 1180 if (ovsl_dereference(ma->masks[index])) 1181 new->masks[new->count++] = ma->masks[index]; 1182 } 1183 1184 rcu_assign_pointer(table->mask_array, new); 1185 call_rcu(&ma->rcu, mask_array_rcu_cb); 1186 1187free_mask_entries: 1188 kfree(masks_and_count); 1189} 1190 1191/* Initializes the flow module. 1192 * Returns zero if successful or a negative error code. */ 1193int ovs_flow_init(void) 1194{ 1195 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long)); 1196 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long)); 1197 1198 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow) 1199 + (nr_cpu_ids 1200 * sizeof(struct sw_flow_stats *)), 1201 0, 0, NULL); 1202 if (flow_cache == NULL) 1203 return -ENOMEM; 1204 1205 flow_stats_cache 1206 = kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats), 1207 0, SLAB_HWCACHE_ALIGN, NULL); 1208 if (flow_stats_cache == NULL) { 1209 kmem_cache_destroy(flow_cache); 1210 flow_cache = NULL; 1211 return -ENOMEM; 1212 } 1213 1214 return 0; 1215} 1216 1217/* Uninitializes the flow module. */ 1218void ovs_flow_exit(void) 1219{ 1220 kmem_cache_destroy(flow_stats_cache); 1221 kmem_cache_destroy(flow_cache); 1222} 1223