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 <net/ip.h> 33 #include <net/ipv6.h> 34 #include <net/ndisc.h> 35 36 #define TBL_MIN_BUCKETS 1024 37 #define MASK_ARRAY_SIZE_MIN 16 38 #define REHASH_INTERVAL (10 * 60 * HZ) 39 40 #define MC_HASH_SHIFT 8 41 #define MC_HASH_ENTRIES (1u << MC_HASH_SHIFT) 42 #define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT) 43 44 static struct kmem_cache *flow_cache; 45 struct kmem_cache *flow_stats_cache __read_mostly; 46 47 static u16 range_n_bytes(const struct sw_flow_key_range *range) 48 { 49 return range->end - range->start; 50 } 51 52 void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src, 53 bool full, const struct sw_flow_mask *mask) 54 { 55 int start = full ? 0 : mask->range.start; 56 int len = full ? sizeof *dst : range_n_bytes(&mask->range); 57 const long *m = (const long *)((const u8 *)&mask->key + start); 58 const long *s = (const long *)((const u8 *)src + start); 59 long *d = (long *)((u8 *)dst + start); 60 int i; 61 62 /* If 'full' is true then all of 'dst' is fully initialized. Otherwise, 63 * if 'full' is false the memory outside of the 'mask->range' is left 64 * uninitialized. This can be used as an optimization when further 65 * operations on 'dst' only use contents within 'mask->range'. 66 */ 67 for (i = 0; i < len; i += sizeof(long)) 68 *d++ = *s++ & *m++; 69 } 70 71 struct sw_flow *ovs_flow_alloc(void) 72 { 73 struct sw_flow *flow; 74 struct sw_flow_stats *stats; 75 76 flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL); 77 if (!flow) 78 return ERR_PTR(-ENOMEM); 79 80 flow->stats_last_writer = -1; 81 82 /* Initialize the default stat node. */ 83 stats = kmem_cache_alloc_node(flow_stats_cache, 84 GFP_KERNEL | __GFP_ZERO, 85 node_online(0) ? 0 : NUMA_NO_NODE); 86 if (!stats) 87 goto err; 88 89 spin_lock_init(&stats->lock); 90 91 RCU_INIT_POINTER(flow->stats[0], stats); 92 93 cpumask_set_cpu(0, &flow->cpu_used_mask); 94 95 return flow; 96 err: 97 kmem_cache_free(flow_cache, flow); 98 return ERR_PTR(-ENOMEM); 99 } 100 101 int ovs_flow_tbl_count(const struct flow_table *table) 102 { 103 return table->count; 104 } 105 106 static void flow_free(struct sw_flow *flow) 107 { 108 int cpu; 109 110 if (ovs_identifier_is_key(&flow->id)) 111 kfree(flow->id.unmasked_key); 112 if (flow->sf_acts) 113 ovs_nla_free_flow_actions((struct sw_flow_actions __force *)flow->sf_acts); 114 /* We open code this to make sure cpu 0 is always considered */ 115 for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask)) 116 if (flow->stats[cpu]) 117 kmem_cache_free(flow_stats_cache, 118 (struct sw_flow_stats __force *)flow->stats[cpu]); 119 kmem_cache_free(flow_cache, flow); 120 } 121 122 static void rcu_free_flow_callback(struct rcu_head *rcu) 123 { 124 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu); 125 126 flow_free(flow); 127 } 128 129 void ovs_flow_free(struct sw_flow *flow, bool deferred) 130 { 131 if (!flow) 132 return; 133 134 if (deferred) 135 call_rcu(&flow->rcu, rcu_free_flow_callback); 136 else 137 flow_free(flow); 138 } 139 140 static void __table_instance_destroy(struct table_instance *ti) 141 { 142 kvfree(ti->buckets); 143 kfree(ti); 144 } 145 146 static struct table_instance *table_instance_alloc(int new_size) 147 { 148 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL); 149 int i; 150 151 if (!ti) 152 return NULL; 153 154 ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head), 155 GFP_KERNEL); 156 if (!ti->buckets) { 157 kfree(ti); 158 return NULL; 159 } 160 161 for (i = 0; i < new_size; i++) 162 INIT_HLIST_HEAD(&ti->buckets[i]); 163 164 ti->n_buckets = new_size; 165 ti->node_ver = 0; 166 ti->keep_flows = false; 167 get_random_bytes(&ti->hash_seed, sizeof(u32)); 168 169 return ti; 170 } 171 172 static struct mask_array *tbl_mask_array_alloc(int size) 173 { 174 struct mask_array *new; 175 176 size = max(MASK_ARRAY_SIZE_MIN, size); 177 new = kzalloc(sizeof(struct mask_array) + 178 sizeof(struct sw_flow_mask *) * size, GFP_KERNEL); 179 if (!new) 180 return NULL; 181 182 new->count = 0; 183 new->max = size; 184 185 return new; 186 } 187 188 static int tbl_mask_array_realloc(struct flow_table *tbl, int size) 189 { 190 struct mask_array *old; 191 struct mask_array *new; 192 193 new = tbl_mask_array_alloc(size); 194 if (!new) 195 return -ENOMEM; 196 197 old = ovsl_dereference(tbl->mask_array); 198 if (old) { 199 int i; 200 201 for (i = 0; i < old->max; i++) { 202 if (ovsl_dereference(old->masks[i])) 203 new->masks[new->count++] = old->masks[i]; 204 } 205 } 206 207 rcu_assign_pointer(tbl->mask_array, new); 208 kfree_rcu(old, rcu); 209 210 return 0; 211 } 212 213 static int tbl_mask_array_add_mask(struct flow_table *tbl, 214 struct sw_flow_mask *new) 215 { 216 struct mask_array *ma = ovsl_dereference(tbl->mask_array); 217 int err, ma_count = READ_ONCE(ma->count); 218 219 if (ma_count >= ma->max) { 220 err = tbl_mask_array_realloc(tbl, ma->max + 221 MASK_ARRAY_SIZE_MIN); 222 if (err) 223 return err; 224 225 ma = ovsl_dereference(tbl->mask_array); 226 } 227 228 BUG_ON(ovsl_dereference(ma->masks[ma_count])); 229 230 rcu_assign_pointer(ma->masks[ma_count], new); 231 WRITE_ONCE(ma->count, ma_count +1); 232 233 return 0; 234 } 235 236 static void tbl_mask_array_del_mask(struct flow_table *tbl, 237 struct sw_flow_mask *mask) 238 { 239 struct mask_array *ma = ovsl_dereference(tbl->mask_array); 240 int i, ma_count = READ_ONCE(ma->count); 241 242 /* Remove the deleted mask pointers from the array */ 243 for (i = 0; i < ma_count; i++) { 244 if (mask == ovsl_dereference(ma->masks[i])) 245 goto found; 246 } 247 248 BUG(); 249 return; 250 251 found: 252 WRITE_ONCE(ma->count, ma_count -1); 253 254 rcu_assign_pointer(ma->masks[i], ma->masks[ma_count -1]); 255 RCU_INIT_POINTER(ma->masks[ma_count -1], NULL); 256 257 kfree_rcu(mask, rcu); 258 259 /* Shrink the mask array if necessary. */ 260 if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) && 261 ma_count <= (ma->max / 3)) 262 tbl_mask_array_realloc(tbl, ma->max / 2); 263 } 264 265 /* Remove 'mask' from the mask list, if it is not needed any more. */ 266 static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask) 267 { 268 if (mask) { 269 /* ovs-lock is required to protect mask-refcount and 270 * mask list. 271 */ 272 ASSERT_OVSL(); 273 BUG_ON(!mask->ref_count); 274 mask->ref_count--; 275 276 if (!mask->ref_count) 277 tbl_mask_array_del_mask(tbl, mask); 278 } 279 } 280 281 int ovs_flow_tbl_init(struct flow_table *table) 282 { 283 struct table_instance *ti, *ufid_ti; 284 struct mask_array *ma; 285 286 table->mask_cache = __alloc_percpu(sizeof(struct mask_cache_entry) * 287 MC_HASH_ENTRIES, 288 __alignof__(struct mask_cache_entry)); 289 if (!table->mask_cache) 290 return -ENOMEM; 291 292 ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN); 293 if (!ma) 294 goto free_mask_cache; 295 296 ti = table_instance_alloc(TBL_MIN_BUCKETS); 297 if (!ti) 298 goto free_mask_array; 299 300 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 301 if (!ufid_ti) 302 goto free_ti; 303 304 rcu_assign_pointer(table->ti, ti); 305 rcu_assign_pointer(table->ufid_ti, ufid_ti); 306 rcu_assign_pointer(table->mask_array, ma); 307 table->last_rehash = jiffies; 308 table->count = 0; 309 table->ufid_count = 0; 310 return 0; 311 312 free_ti: 313 __table_instance_destroy(ti); 314 free_mask_array: 315 kfree(ma); 316 free_mask_cache: 317 free_percpu(table->mask_cache); 318 return -ENOMEM; 319 } 320 321 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu) 322 { 323 struct table_instance *ti = container_of(rcu, struct table_instance, rcu); 324 325 __table_instance_destroy(ti); 326 } 327 328 static void table_instance_flow_free(struct flow_table *table, 329 struct table_instance *ti, 330 struct table_instance *ufid_ti, 331 struct sw_flow *flow, 332 bool count) 333 { 334 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]); 335 if (count) 336 table->count--; 337 338 if (ovs_identifier_is_ufid(&flow->id)) { 339 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]); 340 341 if (count) 342 table->ufid_count--; 343 } 344 345 flow_mask_remove(table, flow->mask); 346 } 347 348 static void table_instance_destroy(struct flow_table *table, 349 struct table_instance *ti, 350 struct table_instance *ufid_ti, 351 bool deferred) 352 { 353 int i; 354 355 if (!ti) 356 return; 357 358 BUG_ON(!ufid_ti); 359 if (ti->keep_flows) 360 goto skip_flows; 361 362 for (i = 0; i < ti->n_buckets; i++) { 363 struct sw_flow *flow; 364 struct hlist_head *head = &ti->buckets[i]; 365 struct hlist_node *n; 366 367 hlist_for_each_entry_safe(flow, n, head, 368 flow_table.node[ti->node_ver]) { 369 370 table_instance_flow_free(table, ti, ufid_ti, 371 flow, false); 372 ovs_flow_free(flow, deferred); 373 } 374 } 375 376 skip_flows: 377 if (deferred) { 378 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 379 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); 380 } else { 381 __table_instance_destroy(ti); 382 __table_instance_destroy(ufid_ti); 383 } 384 } 385 386 /* No need for locking this function is called from RCU callback or 387 * error path. 388 */ 389 void ovs_flow_tbl_destroy(struct flow_table *table) 390 { 391 struct table_instance *ti = rcu_dereference_raw(table->ti); 392 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti); 393 394 free_percpu(table->mask_cache); 395 kfree_rcu(rcu_dereference_raw(table->mask_array), rcu); 396 table_instance_destroy(table, ti, ufid_ti, false); 397 } 398 399 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti, 400 u32 *bucket, u32 *last) 401 { 402 struct sw_flow *flow; 403 struct hlist_head *head; 404 int ver; 405 int i; 406 407 ver = ti->node_ver; 408 while (*bucket < ti->n_buckets) { 409 i = 0; 410 head = &ti->buckets[*bucket]; 411 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) { 412 if (i < *last) { 413 i++; 414 continue; 415 } 416 *last = i + 1; 417 return flow; 418 } 419 (*bucket)++; 420 *last = 0; 421 } 422 423 return NULL; 424 } 425 426 static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash) 427 { 428 hash = jhash_1word(hash, ti->hash_seed); 429 return &ti->buckets[hash & (ti->n_buckets - 1)]; 430 } 431 432 static void table_instance_insert(struct table_instance *ti, 433 struct sw_flow *flow) 434 { 435 struct hlist_head *head; 436 437 head = find_bucket(ti, flow->flow_table.hash); 438 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head); 439 } 440 441 static void ufid_table_instance_insert(struct table_instance *ti, 442 struct sw_flow *flow) 443 { 444 struct hlist_head *head; 445 446 head = find_bucket(ti, flow->ufid_table.hash); 447 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head); 448 } 449 450 static void flow_table_copy_flows(struct table_instance *old, 451 struct table_instance *new, bool ufid) 452 { 453 int old_ver; 454 int i; 455 456 old_ver = old->node_ver; 457 new->node_ver = !old_ver; 458 459 /* Insert in new table. */ 460 for (i = 0; i < old->n_buckets; i++) { 461 struct sw_flow *flow; 462 struct hlist_head *head = &old->buckets[i]; 463 464 if (ufid) 465 hlist_for_each_entry_rcu(flow, head, 466 ufid_table.node[old_ver], 467 lockdep_ovsl_is_held()) 468 ufid_table_instance_insert(new, flow); 469 else 470 hlist_for_each_entry_rcu(flow, head, 471 flow_table.node[old_ver], 472 lockdep_ovsl_is_held()) 473 table_instance_insert(new, flow); 474 } 475 476 old->keep_flows = true; 477 } 478 479 static struct table_instance *table_instance_rehash(struct table_instance *ti, 480 int n_buckets, bool ufid) 481 { 482 struct table_instance *new_ti; 483 484 new_ti = table_instance_alloc(n_buckets); 485 if (!new_ti) 486 return NULL; 487 488 flow_table_copy_flows(ti, new_ti, ufid); 489 490 return new_ti; 491 } 492 493 int ovs_flow_tbl_flush(struct flow_table *flow_table) 494 { 495 struct table_instance *old_ti, *new_ti; 496 struct table_instance *old_ufid_ti, *new_ufid_ti; 497 498 new_ti = table_instance_alloc(TBL_MIN_BUCKETS); 499 if (!new_ti) 500 return -ENOMEM; 501 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 502 if (!new_ufid_ti) 503 goto err_free_ti; 504 505 old_ti = ovsl_dereference(flow_table->ti); 506 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti); 507 508 rcu_assign_pointer(flow_table->ti, new_ti); 509 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti); 510 flow_table->last_rehash = jiffies; 511 flow_table->count = 0; 512 flow_table->ufid_count = 0; 513 514 table_instance_destroy(flow_table, old_ti, old_ufid_ti, true); 515 return 0; 516 517 err_free_ti: 518 __table_instance_destroy(new_ti); 519 return -ENOMEM; 520 } 521 522 static u32 flow_hash(const struct sw_flow_key *key, 523 const struct sw_flow_key_range *range) 524 { 525 const u32 *hash_key = (const u32 *)((const u8 *)key + range->start); 526 527 /* Make sure number of hash bytes are multiple of u32. */ 528 int hash_u32s = range_n_bytes(range) >> 2; 529 530 return jhash2(hash_key, hash_u32s, 0); 531 } 532 533 static int flow_key_start(const struct sw_flow_key *key) 534 { 535 if (key->tun_proto) 536 return 0; 537 else 538 return rounddown(offsetof(struct sw_flow_key, phy), 539 sizeof(long)); 540 } 541 542 static bool cmp_key(const struct sw_flow_key *key1, 543 const struct sw_flow_key *key2, 544 int key_start, int key_end) 545 { 546 const long *cp1 = (const long *)((const u8 *)key1 + key_start); 547 const long *cp2 = (const long *)((const u8 *)key2 + key_start); 548 long diffs = 0; 549 int i; 550 551 for (i = key_start; i < key_end; i += sizeof(long)) 552 diffs |= *cp1++ ^ *cp2++; 553 554 return diffs == 0; 555 } 556 557 static bool flow_cmp_masked_key(const struct sw_flow *flow, 558 const struct sw_flow_key *key, 559 const struct sw_flow_key_range *range) 560 { 561 return cmp_key(&flow->key, key, range->start, range->end); 562 } 563 564 static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow, 565 const struct sw_flow_match *match) 566 { 567 struct sw_flow_key *key = match->key; 568 int key_start = flow_key_start(key); 569 int key_end = match->range.end; 570 571 BUG_ON(ovs_identifier_is_ufid(&flow->id)); 572 return cmp_key(flow->id.unmasked_key, key, key_start, key_end); 573 } 574 575 static struct sw_flow *masked_flow_lookup(struct table_instance *ti, 576 const struct sw_flow_key *unmasked, 577 const struct sw_flow_mask *mask, 578 u32 *n_mask_hit) 579 { 580 struct sw_flow *flow; 581 struct hlist_head *head; 582 u32 hash; 583 struct sw_flow_key masked_key; 584 585 ovs_flow_mask_key(&masked_key, unmasked, false, mask); 586 hash = flow_hash(&masked_key, &mask->range); 587 head = find_bucket(ti, hash); 588 (*n_mask_hit)++; 589 590 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver], 591 lockdep_ovsl_is_held()) { 592 if (flow->mask == mask && flow->flow_table.hash == hash && 593 flow_cmp_masked_key(flow, &masked_key, &mask->range)) 594 return flow; 595 } 596 return NULL; 597 } 598 599 /* Flow lookup does full lookup on flow table. It starts with 600 * mask from index passed in *index. 601 */ 602 static struct sw_flow *flow_lookup(struct flow_table *tbl, 603 struct table_instance *ti, 604 struct mask_array *ma, 605 const struct sw_flow_key *key, 606 u32 *n_mask_hit, 607 u32 *index) 608 { 609 struct sw_flow *flow; 610 struct sw_flow_mask *mask; 611 int i; 612 613 if (likely(*index < ma->max)) { 614 mask = rcu_dereference_ovsl(ma->masks[*index]); 615 if (mask) { 616 flow = masked_flow_lookup(ti, key, mask, n_mask_hit); 617 if (flow) 618 return flow; 619 } 620 } 621 622 for (i = 0; i < ma->max; i++) { 623 624 if (i == *index) 625 continue; 626 627 mask = rcu_dereference_ovsl(ma->masks[i]); 628 if (unlikely(!mask)) 629 break; 630 631 flow = masked_flow_lookup(ti, key, mask, n_mask_hit); 632 if (flow) { /* Found */ 633 *index = i; 634 return flow; 635 } 636 } 637 638 return NULL; 639 } 640 641 /* 642 * mask_cache maps flow to probable mask. This cache is not tightly 643 * coupled cache, It means updates to mask list can result in inconsistent 644 * cache entry in mask cache. 645 * This is per cpu cache and is divided in MC_HASH_SEGS segments. 646 * In case of a hash collision the entry is hashed in next segment. 647 * */ 648 struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl, 649 const struct sw_flow_key *key, 650 u32 skb_hash, 651 u32 *n_mask_hit) 652 { 653 struct mask_array *ma = rcu_dereference(tbl->mask_array); 654 struct table_instance *ti = rcu_dereference(tbl->ti); 655 struct mask_cache_entry *entries, *ce; 656 struct sw_flow *flow; 657 u32 hash; 658 int seg; 659 660 *n_mask_hit = 0; 661 if (unlikely(!skb_hash)) { 662 u32 mask_index = 0; 663 664 return flow_lookup(tbl, ti, ma, key, n_mask_hit, &mask_index); 665 } 666 667 /* Pre and post recirulation flows usually have the same skb_hash 668 * value. To avoid hash collisions, rehash the 'skb_hash' with 669 * 'recirc_id'. */ 670 if (key->recirc_id) 671 skb_hash = jhash_1word(skb_hash, key->recirc_id); 672 673 ce = NULL; 674 hash = skb_hash; 675 entries = this_cpu_ptr(tbl->mask_cache); 676 677 /* Find the cache entry 'ce' to operate on. */ 678 for (seg = 0; seg < MC_HASH_SEGS; seg++) { 679 int index = hash & (MC_HASH_ENTRIES - 1); 680 struct mask_cache_entry *e; 681 682 e = &entries[index]; 683 if (e->skb_hash == skb_hash) { 684 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, 685 &e->mask_index); 686 if (!flow) 687 e->skb_hash = 0; 688 return flow; 689 } 690 691 if (!ce || e->skb_hash < ce->skb_hash) 692 ce = e; /* A better replacement cache candidate. */ 693 694 hash >>= MC_HASH_SHIFT; 695 } 696 697 /* Cache miss, do full lookup. */ 698 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, &ce->mask_index); 699 if (flow) 700 ce->skb_hash = skb_hash; 701 702 return flow; 703 } 704 705 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl, 706 const struct sw_flow_key *key) 707 { 708 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 709 struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array); 710 u32 __always_unused n_mask_hit; 711 u32 index = 0; 712 713 return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &index); 714 } 715 716 struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl, 717 const struct sw_flow_match *match) 718 { 719 struct mask_array *ma = ovsl_dereference(tbl->mask_array); 720 int i; 721 722 /* Always called under ovs-mutex. */ 723 for (i = 0; i < ma->max; i++) { 724 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 725 u32 __always_unused n_mask_hit; 726 struct sw_flow_mask *mask; 727 struct sw_flow *flow; 728 729 mask = ovsl_dereference(ma->masks[i]); 730 if (!mask) 731 continue; 732 733 flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit); 734 if (flow && ovs_identifier_is_key(&flow->id) && 735 ovs_flow_cmp_unmasked_key(flow, match)) { 736 return flow; 737 } 738 } 739 740 return NULL; 741 } 742 743 static u32 ufid_hash(const struct sw_flow_id *sfid) 744 { 745 return jhash(sfid->ufid, sfid->ufid_len, 0); 746 } 747 748 static bool ovs_flow_cmp_ufid(const struct sw_flow *flow, 749 const struct sw_flow_id *sfid) 750 { 751 if (flow->id.ufid_len != sfid->ufid_len) 752 return false; 753 754 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len); 755 } 756 757 bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match) 758 { 759 if (ovs_identifier_is_ufid(&flow->id)) 760 return flow_cmp_masked_key(flow, match->key, &match->range); 761 762 return ovs_flow_cmp_unmasked_key(flow, match); 763 } 764 765 struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl, 766 const struct sw_flow_id *ufid) 767 { 768 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti); 769 struct sw_flow *flow; 770 struct hlist_head *head; 771 u32 hash; 772 773 hash = ufid_hash(ufid); 774 head = find_bucket(ti, hash); 775 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver], 776 lockdep_ovsl_is_held()) { 777 if (flow->ufid_table.hash == hash && 778 ovs_flow_cmp_ufid(flow, ufid)) 779 return flow; 780 } 781 return NULL; 782 } 783 784 int ovs_flow_tbl_num_masks(const struct flow_table *table) 785 { 786 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array); 787 return READ_ONCE(ma->count); 788 } 789 790 static struct table_instance *table_instance_expand(struct table_instance *ti, 791 bool ufid) 792 { 793 return table_instance_rehash(ti, ti->n_buckets * 2, ufid); 794 } 795 796 /* Must be called with OVS mutex held. */ 797 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow) 798 { 799 struct table_instance *ti = ovsl_dereference(table->ti); 800 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti); 801 802 BUG_ON(table->count == 0); 803 table_instance_flow_free(table, ti, ufid_ti, flow, true); 804 } 805 806 static struct sw_flow_mask *mask_alloc(void) 807 { 808 struct sw_flow_mask *mask; 809 810 mask = kmalloc(sizeof(*mask), GFP_KERNEL); 811 if (mask) 812 mask->ref_count = 1; 813 814 return mask; 815 } 816 817 static bool mask_equal(const struct sw_flow_mask *a, 818 const struct sw_flow_mask *b) 819 { 820 const u8 *a_ = (const u8 *)&a->key + a->range.start; 821 const u8 *b_ = (const u8 *)&b->key + b->range.start; 822 823 return (a->range.end == b->range.end) 824 && (a->range.start == b->range.start) 825 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0); 826 } 827 828 static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl, 829 const struct sw_flow_mask *mask) 830 { 831 struct mask_array *ma; 832 int i; 833 834 ma = ovsl_dereference(tbl->mask_array); 835 for (i = 0; i < ma->max; i++) { 836 struct sw_flow_mask *t; 837 t = ovsl_dereference(ma->masks[i]); 838 839 if (t && mask_equal(mask, t)) 840 return t; 841 } 842 843 return NULL; 844 } 845 846 /* Add 'mask' into the mask list, if it is not already there. */ 847 static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, 848 const struct sw_flow_mask *new) 849 { 850 struct sw_flow_mask *mask; 851 852 mask = flow_mask_find(tbl, new); 853 if (!mask) { 854 /* Allocate a new mask if none exsits. */ 855 mask = mask_alloc(); 856 if (!mask) 857 return -ENOMEM; 858 mask->key = new->key; 859 mask->range = new->range; 860 861 /* Add mask to mask-list. */ 862 if (tbl_mask_array_add_mask(tbl, mask)) { 863 kfree(mask); 864 return -ENOMEM; 865 } 866 } else { 867 BUG_ON(!mask->ref_count); 868 mask->ref_count++; 869 } 870 871 flow->mask = mask; 872 return 0; 873 } 874 875 /* Must be called with OVS mutex held. */ 876 static void flow_key_insert(struct flow_table *table, struct sw_flow *flow) 877 { 878 struct table_instance *new_ti = NULL; 879 struct table_instance *ti; 880 881 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range); 882 ti = ovsl_dereference(table->ti); 883 table_instance_insert(ti, flow); 884 table->count++; 885 886 /* Expand table, if necessary, to make room. */ 887 if (table->count > ti->n_buckets) 888 new_ti = table_instance_expand(ti, false); 889 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL)) 890 new_ti = table_instance_rehash(ti, ti->n_buckets, false); 891 892 if (new_ti) { 893 rcu_assign_pointer(table->ti, new_ti); 894 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 895 table->last_rehash = jiffies; 896 } 897 } 898 899 /* Must be called with OVS mutex held. */ 900 static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow) 901 { 902 struct table_instance *ti; 903 904 flow->ufid_table.hash = ufid_hash(&flow->id); 905 ti = ovsl_dereference(table->ufid_ti); 906 ufid_table_instance_insert(ti, flow); 907 table->ufid_count++; 908 909 /* Expand table, if necessary, to make room. */ 910 if (table->ufid_count > ti->n_buckets) { 911 struct table_instance *new_ti; 912 913 new_ti = table_instance_expand(ti, true); 914 if (new_ti) { 915 rcu_assign_pointer(table->ufid_ti, new_ti); 916 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 917 } 918 } 919 } 920 921 /* Must be called with OVS mutex held. */ 922 int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow, 923 const struct sw_flow_mask *mask) 924 { 925 int err; 926 927 err = flow_mask_insert(table, flow, mask); 928 if (err) 929 return err; 930 flow_key_insert(table, flow); 931 if (ovs_identifier_is_ufid(&flow->id)) 932 flow_ufid_insert(table, flow); 933 934 return 0; 935 } 936 937 /* Initializes the flow module. 938 * Returns zero if successful or a negative error code. */ 939 int ovs_flow_init(void) 940 { 941 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long)); 942 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long)); 943 944 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow) 945 + (nr_cpu_ids 946 * sizeof(struct sw_flow_stats *)), 947 0, 0, NULL); 948 if (flow_cache == NULL) 949 return -ENOMEM; 950 951 flow_stats_cache 952 = kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats), 953 0, SLAB_HWCACHE_ALIGN, NULL); 954 if (flow_stats_cache == NULL) { 955 kmem_cache_destroy(flow_cache); 956 flow_cache = NULL; 957 return -ENOMEM; 958 } 959 960 return 0; 961 } 962 963 /* Uninitializes the flow module. */ 964 void ovs_flow_exit(void) 965 { 966 kmem_cache_destroy(flow_stats_cache); 967 kmem_cache_destroy(flow_cache); 968 } 969