1 /* 2 * Copyright (c) 2007-2014 Nicira, Inc. 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of version 2 of the GNU General Public 6 * License as published by the Free Software Foundation. 7 * 8 * This program is distributed in the hope that it will be useful, but 9 * WITHOUT ANY WARRANTY; without even the implied warranty of 10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 11 * General Public License for more details. 12 * 13 * You should have received a copy of the GNU General Public License 14 * along with this program; if not, write to the Free Software 15 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 16 * 02110-1301, USA 17 */ 18 19 #include "flow.h" 20 #include "datapath.h" 21 #include <linux/uaccess.h> 22 #include <linux/netdevice.h> 23 #include <linux/etherdevice.h> 24 #include <linux/if_ether.h> 25 #include <linux/if_vlan.h> 26 #include <net/llc_pdu.h> 27 #include <linux/kernel.h> 28 #include <linux/jhash.h> 29 #include <linux/jiffies.h> 30 #include <linux/llc.h> 31 #include <linux/module.h> 32 #include <linux/in.h> 33 #include <linux/rcupdate.h> 34 #include <linux/if_arp.h> 35 #include <linux/ip.h> 36 #include <linux/ipv6.h> 37 #include <linux/sctp.h> 38 #include <linux/tcp.h> 39 #include <linux/udp.h> 40 #include <linux/icmp.h> 41 #include <linux/icmpv6.h> 42 #include <linux/rculist.h> 43 #include <net/ip.h> 44 #include <net/ipv6.h> 45 #include <net/ndisc.h> 46 47 #define TBL_MIN_BUCKETS 1024 48 #define REHASH_INTERVAL (10 * 60 * HZ) 49 50 static struct kmem_cache *flow_cache; 51 struct kmem_cache *flow_stats_cache __read_mostly; 52 53 static u16 range_n_bytes(const struct sw_flow_key_range *range) 54 { 55 return range->end - range->start; 56 } 57 58 void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src, 59 const struct sw_flow_mask *mask) 60 { 61 const long *m = (const long *)((const u8 *)&mask->key + 62 mask->range.start); 63 const long *s = (const long *)((const u8 *)src + 64 mask->range.start); 65 long *d = (long *)((u8 *)dst + mask->range.start); 66 int i; 67 68 /* The memory outside of the 'mask->range' are not set since 69 * further operations on 'dst' only uses contents within 70 * 'mask->range'. 71 */ 72 for (i = 0; i < range_n_bytes(&mask->range); i += sizeof(long)) 73 *d++ = *s++ & *m++; 74 } 75 76 struct sw_flow *ovs_flow_alloc(void) 77 { 78 struct sw_flow *flow; 79 struct flow_stats *stats; 80 int node; 81 82 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL); 83 if (!flow) 84 return ERR_PTR(-ENOMEM); 85 86 flow->sf_acts = NULL; 87 flow->mask = NULL; 88 flow->id.unmasked_key = NULL; 89 flow->id.ufid_len = 0; 90 flow->stats_last_writer = NUMA_NO_NODE; 91 92 /* Initialize the default stat node. */ 93 stats = kmem_cache_alloc_node(flow_stats_cache, 94 GFP_KERNEL | __GFP_ZERO, 0); 95 if (!stats) 96 goto err; 97 98 spin_lock_init(&stats->lock); 99 100 RCU_INIT_POINTER(flow->stats[0], stats); 101 102 for_each_node(node) 103 if (node != 0) 104 RCU_INIT_POINTER(flow->stats[node], NULL); 105 106 return flow; 107 err: 108 kmem_cache_free(flow_cache, flow); 109 return ERR_PTR(-ENOMEM); 110 } 111 112 int ovs_flow_tbl_count(const struct flow_table *table) 113 { 114 return table->count; 115 } 116 117 static struct flex_array *alloc_buckets(unsigned int n_buckets) 118 { 119 struct flex_array *buckets; 120 int i, err; 121 122 buckets = flex_array_alloc(sizeof(struct hlist_head), 123 n_buckets, GFP_KERNEL); 124 if (!buckets) 125 return NULL; 126 127 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL); 128 if (err) { 129 flex_array_free(buckets); 130 return NULL; 131 } 132 133 for (i = 0; i < n_buckets; i++) 134 INIT_HLIST_HEAD((struct hlist_head *) 135 flex_array_get(buckets, i)); 136 137 return buckets; 138 } 139 140 static void flow_free(struct sw_flow *flow) 141 { 142 int node; 143 144 if (ovs_identifier_is_key(&flow->id)) 145 kfree(flow->id.unmasked_key); 146 kfree((struct sw_flow_actions __force *)flow->sf_acts); 147 for_each_node(node) 148 if (flow->stats[node]) 149 kmem_cache_free(flow_stats_cache, 150 (struct flow_stats __force *)flow->stats[node]); 151 kmem_cache_free(flow_cache, flow); 152 } 153 154 static void rcu_free_flow_callback(struct rcu_head *rcu) 155 { 156 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu); 157 158 flow_free(flow); 159 } 160 161 void ovs_flow_free(struct sw_flow *flow, bool deferred) 162 { 163 if (!flow) 164 return; 165 166 if (deferred) 167 call_rcu(&flow->rcu, rcu_free_flow_callback); 168 else 169 flow_free(flow); 170 } 171 172 static void free_buckets(struct flex_array *buckets) 173 { 174 flex_array_free(buckets); 175 } 176 177 178 static void __table_instance_destroy(struct table_instance *ti) 179 { 180 free_buckets(ti->buckets); 181 kfree(ti); 182 } 183 184 static struct table_instance *table_instance_alloc(int new_size) 185 { 186 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL); 187 188 if (!ti) 189 return NULL; 190 191 ti->buckets = alloc_buckets(new_size); 192 193 if (!ti->buckets) { 194 kfree(ti); 195 return NULL; 196 } 197 ti->n_buckets = new_size; 198 ti->node_ver = 0; 199 ti->keep_flows = false; 200 get_random_bytes(&ti->hash_seed, sizeof(u32)); 201 202 return ti; 203 } 204 205 int ovs_flow_tbl_init(struct flow_table *table) 206 { 207 struct table_instance *ti, *ufid_ti; 208 209 ti = table_instance_alloc(TBL_MIN_BUCKETS); 210 211 if (!ti) 212 return -ENOMEM; 213 214 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 215 if (!ufid_ti) 216 goto free_ti; 217 218 rcu_assign_pointer(table->ti, ti); 219 rcu_assign_pointer(table->ufid_ti, ufid_ti); 220 INIT_LIST_HEAD(&table->mask_list); 221 table->last_rehash = jiffies; 222 table->count = 0; 223 table->ufid_count = 0; 224 return 0; 225 226 free_ti: 227 __table_instance_destroy(ti); 228 return -ENOMEM; 229 } 230 231 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu) 232 { 233 struct table_instance *ti = container_of(rcu, struct table_instance, rcu); 234 235 __table_instance_destroy(ti); 236 } 237 238 static void table_instance_destroy(struct table_instance *ti, 239 struct table_instance *ufid_ti, 240 bool deferred) 241 { 242 int i; 243 244 if (!ti) 245 return; 246 247 BUG_ON(!ufid_ti); 248 if (ti->keep_flows) 249 goto skip_flows; 250 251 for (i = 0; i < ti->n_buckets; i++) { 252 struct sw_flow *flow; 253 struct hlist_head *head = flex_array_get(ti->buckets, i); 254 struct hlist_node *n; 255 int ver = ti->node_ver; 256 int ufid_ver = ufid_ti->node_ver; 257 258 hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) { 259 hlist_del_rcu(&flow->flow_table.node[ver]); 260 if (ovs_identifier_is_ufid(&flow->id)) 261 hlist_del_rcu(&flow->ufid_table.node[ufid_ver]); 262 ovs_flow_free(flow, deferred); 263 } 264 } 265 266 skip_flows: 267 if (deferred) { 268 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 269 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); 270 } else { 271 __table_instance_destroy(ti); 272 __table_instance_destroy(ufid_ti); 273 } 274 } 275 276 /* No need for locking this function is called from RCU callback or 277 * error path. 278 */ 279 void ovs_flow_tbl_destroy(struct flow_table *table) 280 { 281 struct table_instance *ti = rcu_dereference_raw(table->ti); 282 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti); 283 284 table_instance_destroy(ti, ufid_ti, false); 285 } 286 287 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti, 288 u32 *bucket, u32 *last) 289 { 290 struct sw_flow *flow; 291 struct hlist_head *head; 292 int ver; 293 int i; 294 295 ver = ti->node_ver; 296 while (*bucket < ti->n_buckets) { 297 i = 0; 298 head = flex_array_get(ti->buckets, *bucket); 299 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) { 300 if (i < *last) { 301 i++; 302 continue; 303 } 304 *last = i + 1; 305 return flow; 306 } 307 (*bucket)++; 308 *last = 0; 309 } 310 311 return NULL; 312 } 313 314 static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash) 315 { 316 hash = jhash_1word(hash, ti->hash_seed); 317 return flex_array_get(ti->buckets, 318 (hash & (ti->n_buckets - 1))); 319 } 320 321 static void table_instance_insert(struct table_instance *ti, 322 struct sw_flow *flow) 323 { 324 struct hlist_head *head; 325 326 head = find_bucket(ti, flow->flow_table.hash); 327 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head); 328 } 329 330 static void ufid_table_instance_insert(struct table_instance *ti, 331 struct sw_flow *flow) 332 { 333 struct hlist_head *head; 334 335 head = find_bucket(ti, flow->ufid_table.hash); 336 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head); 337 } 338 339 static void flow_table_copy_flows(struct table_instance *old, 340 struct table_instance *new, bool ufid) 341 { 342 int old_ver; 343 int i; 344 345 old_ver = old->node_ver; 346 new->node_ver = !old_ver; 347 348 /* Insert in new table. */ 349 for (i = 0; i < old->n_buckets; i++) { 350 struct sw_flow *flow; 351 struct hlist_head *head; 352 353 head = flex_array_get(old->buckets, i); 354 355 if (ufid) 356 hlist_for_each_entry(flow, head, 357 ufid_table.node[old_ver]) 358 ufid_table_instance_insert(new, flow); 359 else 360 hlist_for_each_entry(flow, head, 361 flow_table.node[old_ver]) 362 table_instance_insert(new, flow); 363 } 364 365 old->keep_flows = true; 366 } 367 368 static struct table_instance *table_instance_rehash(struct table_instance *ti, 369 int n_buckets, bool ufid) 370 { 371 struct table_instance *new_ti; 372 373 new_ti = table_instance_alloc(n_buckets); 374 if (!new_ti) 375 return NULL; 376 377 flow_table_copy_flows(ti, new_ti, ufid); 378 379 return new_ti; 380 } 381 382 int ovs_flow_tbl_flush(struct flow_table *flow_table) 383 { 384 struct table_instance *old_ti, *new_ti; 385 struct table_instance *old_ufid_ti, *new_ufid_ti; 386 387 new_ti = table_instance_alloc(TBL_MIN_BUCKETS); 388 if (!new_ti) 389 return -ENOMEM; 390 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 391 if (!new_ufid_ti) 392 goto err_free_ti; 393 394 old_ti = ovsl_dereference(flow_table->ti); 395 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti); 396 397 rcu_assign_pointer(flow_table->ti, new_ti); 398 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti); 399 flow_table->last_rehash = jiffies; 400 flow_table->count = 0; 401 flow_table->ufid_count = 0; 402 403 table_instance_destroy(old_ti, old_ufid_ti, true); 404 return 0; 405 406 err_free_ti: 407 __table_instance_destroy(new_ti); 408 return -ENOMEM; 409 } 410 411 static u32 flow_hash(const struct sw_flow_key *key, 412 const struct sw_flow_key_range *range) 413 { 414 int key_start = range->start; 415 int key_end = range->end; 416 const u32 *hash_key = (const u32 *)((const u8 *)key + key_start); 417 int hash_u32s = (key_end - key_start) >> 2; 418 419 /* Make sure number of hash bytes are multiple of u32. */ 420 BUILD_BUG_ON(sizeof(long) % sizeof(u32)); 421 422 return jhash2(hash_key, hash_u32s, 0); 423 } 424 425 static int flow_key_start(const struct sw_flow_key *key) 426 { 427 if (key->tun_key.ipv4_dst) 428 return 0; 429 else 430 return rounddown(offsetof(struct sw_flow_key, phy), 431 sizeof(long)); 432 } 433 434 static bool cmp_key(const struct sw_flow_key *key1, 435 const struct sw_flow_key *key2, 436 int key_start, int key_end) 437 { 438 const long *cp1 = (const long *)((const u8 *)key1 + key_start); 439 const long *cp2 = (const long *)((const u8 *)key2 + key_start); 440 long diffs = 0; 441 int i; 442 443 for (i = key_start; i < key_end; i += sizeof(long)) 444 diffs |= *cp1++ ^ *cp2++; 445 446 return diffs == 0; 447 } 448 449 static bool flow_cmp_masked_key(const struct sw_flow *flow, 450 const struct sw_flow_key *key, 451 const struct sw_flow_key_range *range) 452 { 453 return cmp_key(&flow->key, key, range->start, range->end); 454 } 455 456 static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow, 457 const struct sw_flow_match *match) 458 { 459 struct sw_flow_key *key = match->key; 460 int key_start = flow_key_start(key); 461 int key_end = match->range.end; 462 463 BUG_ON(ovs_identifier_is_ufid(&flow->id)); 464 return cmp_key(flow->id.unmasked_key, key, key_start, key_end); 465 } 466 467 static struct sw_flow *masked_flow_lookup(struct table_instance *ti, 468 const struct sw_flow_key *unmasked, 469 const struct sw_flow_mask *mask) 470 { 471 struct sw_flow *flow; 472 struct hlist_head *head; 473 u32 hash; 474 struct sw_flow_key masked_key; 475 476 ovs_flow_mask_key(&masked_key, unmasked, mask); 477 hash = flow_hash(&masked_key, &mask->range); 478 head = find_bucket(ti, hash); 479 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) { 480 if (flow->mask == mask && flow->flow_table.hash == hash && 481 flow_cmp_masked_key(flow, &masked_key, &mask->range)) 482 return flow; 483 } 484 return NULL; 485 } 486 487 struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl, 488 const struct sw_flow_key *key, 489 u32 *n_mask_hit) 490 { 491 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 492 struct sw_flow_mask *mask; 493 struct sw_flow *flow; 494 495 *n_mask_hit = 0; 496 list_for_each_entry_rcu(mask, &tbl->mask_list, list) { 497 (*n_mask_hit)++; 498 flow = masked_flow_lookup(ti, key, mask); 499 if (flow) /* Found */ 500 return flow; 501 } 502 return NULL; 503 } 504 505 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl, 506 const struct sw_flow_key *key) 507 { 508 u32 __always_unused n_mask_hit; 509 510 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit); 511 } 512 513 struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl, 514 const struct sw_flow_match *match) 515 { 516 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 517 struct sw_flow_mask *mask; 518 struct sw_flow *flow; 519 520 /* Always called under ovs-mutex. */ 521 list_for_each_entry(mask, &tbl->mask_list, list) { 522 flow = masked_flow_lookup(ti, match->key, mask); 523 if (flow && ovs_identifier_is_key(&flow->id) && 524 ovs_flow_cmp_unmasked_key(flow, match)) 525 return flow; 526 } 527 return NULL; 528 } 529 530 static u32 ufid_hash(const struct sw_flow_id *sfid) 531 { 532 return jhash(sfid->ufid, sfid->ufid_len, 0); 533 } 534 535 static bool ovs_flow_cmp_ufid(const struct sw_flow *flow, 536 const struct sw_flow_id *sfid) 537 { 538 if (flow->id.ufid_len != sfid->ufid_len) 539 return false; 540 541 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len); 542 } 543 544 bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match) 545 { 546 if (ovs_identifier_is_ufid(&flow->id)) 547 return flow_cmp_masked_key(flow, match->key, &match->range); 548 549 return ovs_flow_cmp_unmasked_key(flow, match); 550 } 551 552 struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl, 553 const struct sw_flow_id *ufid) 554 { 555 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti); 556 struct sw_flow *flow; 557 struct hlist_head *head; 558 u32 hash; 559 560 hash = ufid_hash(ufid); 561 head = find_bucket(ti, hash); 562 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) { 563 if (flow->ufid_table.hash == hash && 564 ovs_flow_cmp_ufid(flow, ufid)) 565 return flow; 566 } 567 return NULL; 568 } 569 570 int ovs_flow_tbl_num_masks(const struct flow_table *table) 571 { 572 struct sw_flow_mask *mask; 573 int num = 0; 574 575 list_for_each_entry(mask, &table->mask_list, list) 576 num++; 577 578 return num; 579 } 580 581 static struct table_instance *table_instance_expand(struct table_instance *ti, 582 bool ufid) 583 { 584 return table_instance_rehash(ti, ti->n_buckets * 2, ufid); 585 } 586 587 /* Remove 'mask' from the mask list, if it is not needed any more. */ 588 static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask) 589 { 590 if (mask) { 591 /* ovs-lock is required to protect mask-refcount and 592 * mask list. 593 */ 594 ASSERT_OVSL(); 595 BUG_ON(!mask->ref_count); 596 mask->ref_count--; 597 598 if (!mask->ref_count) { 599 list_del_rcu(&mask->list); 600 kfree_rcu(mask, rcu); 601 } 602 } 603 } 604 605 /* Must be called with OVS mutex held. */ 606 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow) 607 { 608 struct table_instance *ti = ovsl_dereference(table->ti); 609 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti); 610 611 BUG_ON(table->count == 0); 612 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]); 613 table->count--; 614 if (ovs_identifier_is_ufid(&flow->id)) { 615 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]); 616 table->ufid_count--; 617 } 618 619 /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be 620 * accessible as long as the RCU read lock is held. 621 */ 622 flow_mask_remove(table, flow->mask); 623 } 624 625 static struct sw_flow_mask *mask_alloc(void) 626 { 627 struct sw_flow_mask *mask; 628 629 mask = kmalloc(sizeof(*mask), GFP_KERNEL); 630 if (mask) 631 mask->ref_count = 1; 632 633 return mask; 634 } 635 636 static bool mask_equal(const struct sw_flow_mask *a, 637 const struct sw_flow_mask *b) 638 { 639 const u8 *a_ = (const u8 *)&a->key + a->range.start; 640 const u8 *b_ = (const u8 *)&b->key + b->range.start; 641 642 return (a->range.end == b->range.end) 643 && (a->range.start == b->range.start) 644 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0); 645 } 646 647 static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl, 648 const struct sw_flow_mask *mask) 649 { 650 struct list_head *ml; 651 652 list_for_each(ml, &tbl->mask_list) { 653 struct sw_flow_mask *m; 654 m = container_of(ml, struct sw_flow_mask, list); 655 if (mask_equal(mask, m)) 656 return m; 657 } 658 659 return NULL; 660 } 661 662 /* Add 'mask' into the mask list, if it is not already there. */ 663 static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, 664 const struct sw_flow_mask *new) 665 { 666 struct sw_flow_mask *mask; 667 mask = flow_mask_find(tbl, new); 668 if (!mask) { 669 /* Allocate a new mask if none exsits. */ 670 mask = mask_alloc(); 671 if (!mask) 672 return -ENOMEM; 673 mask->key = new->key; 674 mask->range = new->range; 675 list_add_rcu(&mask->list, &tbl->mask_list); 676 } else { 677 BUG_ON(!mask->ref_count); 678 mask->ref_count++; 679 } 680 681 flow->mask = mask; 682 return 0; 683 } 684 685 /* Must be called with OVS mutex held. */ 686 static void flow_key_insert(struct flow_table *table, struct sw_flow *flow) 687 { 688 struct table_instance *new_ti = NULL; 689 struct table_instance *ti; 690 691 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range); 692 ti = ovsl_dereference(table->ti); 693 table_instance_insert(ti, flow); 694 table->count++; 695 696 /* Expand table, if necessary, to make room. */ 697 if (table->count > ti->n_buckets) 698 new_ti = table_instance_expand(ti, false); 699 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL)) 700 new_ti = table_instance_rehash(ti, ti->n_buckets, false); 701 702 if (new_ti) { 703 rcu_assign_pointer(table->ti, new_ti); 704 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 705 table->last_rehash = jiffies; 706 } 707 } 708 709 /* Must be called with OVS mutex held. */ 710 static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow) 711 { 712 struct table_instance *ti; 713 714 flow->ufid_table.hash = ufid_hash(&flow->id); 715 ti = ovsl_dereference(table->ufid_ti); 716 ufid_table_instance_insert(ti, flow); 717 table->ufid_count++; 718 719 /* Expand table, if necessary, to make room. */ 720 if (table->ufid_count > ti->n_buckets) { 721 struct table_instance *new_ti; 722 723 new_ti = table_instance_expand(ti, true); 724 if (new_ti) { 725 rcu_assign_pointer(table->ufid_ti, new_ti); 726 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 727 } 728 } 729 } 730 731 /* Must be called with OVS mutex held. */ 732 int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow, 733 const struct sw_flow_mask *mask) 734 { 735 int err; 736 737 err = flow_mask_insert(table, flow, mask); 738 if (err) 739 return err; 740 flow_key_insert(table, flow); 741 if (ovs_identifier_is_ufid(&flow->id)) 742 flow_ufid_insert(table, flow); 743 744 return 0; 745 } 746 747 /* Initializes the flow module. 748 * Returns zero if successful or a negative error code. */ 749 int ovs_flow_init(void) 750 { 751 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long)); 752 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long)); 753 754 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow) 755 + (num_possible_nodes() 756 * sizeof(struct flow_stats *)), 757 0, 0, NULL); 758 if (flow_cache == NULL) 759 return -ENOMEM; 760 761 flow_stats_cache 762 = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats), 763 0, SLAB_HWCACHE_ALIGN, NULL); 764 if (flow_stats_cache == NULL) { 765 kmem_cache_destroy(flow_cache); 766 flow_cache = NULL; 767 return -ENOMEM; 768 } 769 770 return 0; 771 } 772 773 /* Uninitializes the flow module. */ 774 void ovs_flow_exit(void) 775 { 776 kmem_cache_destroy(flow_stats_cache); 777 kmem_cache_destroy(flow_cache); 778 } 779