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 50static struct kmem_cache *flow_cache; 51struct kmem_cache *flow_stats_cache __read_mostly; 52 53static u16 range_n_bytes(const struct sw_flow_key_range *range) 54{ 55 return range->end - range->start; 56} 57 58void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src, 59 bool full, const struct sw_flow_mask *mask) 60{ 61 int start = full ? 0 : mask->range.start; 62 int len = full ? sizeof *dst : range_n_bytes(&mask->range); 63 const long *m = (const long *)((const u8 *)&mask->key + start); 64 const long *s = (const long *)((const u8 *)src + start); 65 long *d = (long *)((u8 *)dst + start); 66 int i; 67 68 /* If 'full' is true then all of 'dst' is fully initialized. Otherwise, 69 * if 'full' is false the memory outside of the 'mask->range' is left 70 * uninitialized. This can be used as an optimization when further 71 * operations on 'dst' only use contents within 'mask->range'. 72 */ 73 for (i = 0; i < len; i += sizeof(long)) 74 *d++ = *s++ & *m++; 75} 76 77struct sw_flow *ovs_flow_alloc(void) 78{ 79 struct sw_flow *flow; 80 struct flow_stats *stats; 81 int node; 82 83 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL); 84 if (!flow) 85 return ERR_PTR(-ENOMEM); 86 87 flow->sf_acts = NULL; 88 flow->mask = NULL; 89 flow->id.unmasked_key = NULL; 90 flow->id.ufid_len = 0; 91 flow->stats_last_writer = NUMA_NO_NODE; 92 93 /* Initialize the default stat node. */ 94 stats = kmem_cache_alloc_node(flow_stats_cache, 95 GFP_KERNEL | __GFP_ZERO, 96 node_online(0) ? 0 : NUMA_NO_NODE); 97 if (!stats) 98 goto err; 99 100 spin_lock_init(&stats->lock); 101 102 RCU_INIT_POINTER(flow->stats[0], stats); 103 104 for_each_node(node) 105 if (node != 0) 106 RCU_INIT_POINTER(flow->stats[node], NULL); 107 108 return flow; 109err: 110 kmem_cache_free(flow_cache, flow); 111 return ERR_PTR(-ENOMEM); 112} 113 114int ovs_flow_tbl_count(const struct flow_table *table) 115{ 116 return table->count; 117} 118 119static struct flex_array *alloc_buckets(unsigned int n_buckets) 120{ 121 struct flex_array *buckets; 122 int i, err; 123 124 buckets = flex_array_alloc(sizeof(struct hlist_head), 125 n_buckets, GFP_KERNEL); 126 if (!buckets) 127 return NULL; 128 129 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL); 130 if (err) { 131 flex_array_free(buckets); 132 return NULL; 133 } 134 135 for (i = 0; i < n_buckets; i++) 136 INIT_HLIST_HEAD((struct hlist_head *) 137 flex_array_get(buckets, i)); 138 139 return buckets; 140} 141 142static void flow_free(struct sw_flow *flow) 143{ 144 int node; 145 146 if (ovs_identifier_is_key(&flow->id)) 147 kfree(flow->id.unmasked_key); 148 kfree((struct sw_flow_actions __force *)flow->sf_acts); 149 for_each_node(node) 150 if (flow->stats[node]) 151 kmem_cache_free(flow_stats_cache, 152 (struct flow_stats __force *)flow->stats[node]); 153 kmem_cache_free(flow_cache, flow); 154} 155 156static void rcu_free_flow_callback(struct rcu_head *rcu) 157{ 158 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu); 159 160 flow_free(flow); 161} 162 163void ovs_flow_free(struct sw_flow *flow, bool deferred) 164{ 165 if (!flow) 166 return; 167 168 if (deferred) 169 call_rcu(&flow->rcu, rcu_free_flow_callback); 170 else 171 flow_free(flow); 172} 173 174static void free_buckets(struct flex_array *buckets) 175{ 176 flex_array_free(buckets); 177} 178 179 180static void __table_instance_destroy(struct table_instance *ti) 181{ 182 free_buckets(ti->buckets); 183 kfree(ti); 184} 185 186static struct table_instance *table_instance_alloc(int new_size) 187{ 188 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL); 189 190 if (!ti) 191 return NULL; 192 193 ti->buckets = alloc_buckets(new_size); 194 195 if (!ti->buckets) { 196 kfree(ti); 197 return NULL; 198 } 199 ti->n_buckets = new_size; 200 ti->node_ver = 0; 201 ti->keep_flows = false; 202 get_random_bytes(&ti->hash_seed, sizeof(u32)); 203 204 return ti; 205} 206 207int ovs_flow_tbl_init(struct flow_table *table) 208{ 209 struct table_instance *ti, *ufid_ti; 210 211 ti = table_instance_alloc(TBL_MIN_BUCKETS); 212 213 if (!ti) 214 return -ENOMEM; 215 216 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 217 if (!ufid_ti) 218 goto free_ti; 219 220 rcu_assign_pointer(table->ti, ti); 221 rcu_assign_pointer(table->ufid_ti, ufid_ti); 222 INIT_LIST_HEAD(&table->mask_list); 223 table->last_rehash = jiffies; 224 table->count = 0; 225 table->ufid_count = 0; 226 return 0; 227 228free_ti: 229 __table_instance_destroy(ti); 230 return -ENOMEM; 231} 232 233static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu) 234{ 235 struct table_instance *ti = container_of(rcu, struct table_instance, rcu); 236 237 __table_instance_destroy(ti); 238} 239 240static void table_instance_destroy(struct table_instance *ti, 241 struct table_instance *ufid_ti, 242 bool deferred) 243{ 244 int i; 245 246 if (!ti) 247 return; 248 249 BUG_ON(!ufid_ti); 250 if (ti->keep_flows) 251 goto skip_flows; 252 253 for (i = 0; i < ti->n_buckets; i++) { 254 struct sw_flow *flow; 255 struct hlist_head *head = flex_array_get(ti->buckets, i); 256 struct hlist_node *n; 257 int ver = ti->node_ver; 258 int ufid_ver = ufid_ti->node_ver; 259 260 hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) { 261 hlist_del_rcu(&flow->flow_table.node[ver]); 262 if (ovs_identifier_is_ufid(&flow->id)) 263 hlist_del_rcu(&flow->ufid_table.node[ufid_ver]); 264 ovs_flow_free(flow, deferred); 265 } 266 } 267 268skip_flows: 269 if (deferred) { 270 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 271 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb); 272 } else { 273 __table_instance_destroy(ti); 274 __table_instance_destroy(ufid_ti); 275 } 276} 277 278/* No need for locking this function is called from RCU callback or 279 * error path. 280 */ 281void ovs_flow_tbl_destroy(struct flow_table *table) 282{ 283 struct table_instance *ti = rcu_dereference_raw(table->ti); 284 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti); 285 286 table_instance_destroy(ti, ufid_ti, false); 287} 288 289struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti, 290 u32 *bucket, u32 *last) 291{ 292 struct sw_flow *flow; 293 struct hlist_head *head; 294 int ver; 295 int i; 296 297 ver = ti->node_ver; 298 while (*bucket < ti->n_buckets) { 299 i = 0; 300 head = flex_array_get(ti->buckets, *bucket); 301 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) { 302 if (i < *last) { 303 i++; 304 continue; 305 } 306 *last = i + 1; 307 return flow; 308 } 309 (*bucket)++; 310 *last = 0; 311 } 312 313 return NULL; 314} 315 316static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash) 317{ 318 hash = jhash_1word(hash, ti->hash_seed); 319 return flex_array_get(ti->buckets, 320 (hash & (ti->n_buckets - 1))); 321} 322 323static void table_instance_insert(struct table_instance *ti, 324 struct sw_flow *flow) 325{ 326 struct hlist_head *head; 327 328 head = find_bucket(ti, flow->flow_table.hash); 329 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head); 330} 331 332static void ufid_table_instance_insert(struct table_instance *ti, 333 struct sw_flow *flow) 334{ 335 struct hlist_head *head; 336 337 head = find_bucket(ti, flow->ufid_table.hash); 338 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head); 339} 340 341static void flow_table_copy_flows(struct table_instance *old, 342 struct table_instance *new, bool ufid) 343{ 344 int old_ver; 345 int i; 346 347 old_ver = old->node_ver; 348 new->node_ver = !old_ver; 349 350 /* Insert in new table. */ 351 for (i = 0; i < old->n_buckets; i++) { 352 struct sw_flow *flow; 353 struct hlist_head *head; 354 355 head = flex_array_get(old->buckets, i); 356 357 if (ufid) 358 hlist_for_each_entry(flow, head, 359 ufid_table.node[old_ver]) 360 ufid_table_instance_insert(new, flow); 361 else 362 hlist_for_each_entry(flow, head, 363 flow_table.node[old_ver]) 364 table_instance_insert(new, flow); 365 } 366 367 old->keep_flows = true; 368} 369 370static struct table_instance *table_instance_rehash(struct table_instance *ti, 371 int n_buckets, bool ufid) 372{ 373 struct table_instance *new_ti; 374 375 new_ti = table_instance_alloc(n_buckets); 376 if (!new_ti) 377 return NULL; 378 379 flow_table_copy_flows(ti, new_ti, ufid); 380 381 return new_ti; 382} 383 384int ovs_flow_tbl_flush(struct flow_table *flow_table) 385{ 386 struct table_instance *old_ti, *new_ti; 387 struct table_instance *old_ufid_ti, *new_ufid_ti; 388 389 new_ti = table_instance_alloc(TBL_MIN_BUCKETS); 390 if (!new_ti) 391 return -ENOMEM; 392 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS); 393 if (!new_ufid_ti) 394 goto err_free_ti; 395 396 old_ti = ovsl_dereference(flow_table->ti); 397 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti); 398 399 rcu_assign_pointer(flow_table->ti, new_ti); 400 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti); 401 flow_table->last_rehash = jiffies; 402 flow_table->count = 0; 403 flow_table->ufid_count = 0; 404 405 table_instance_destroy(old_ti, old_ufid_ti, true); 406 return 0; 407 408err_free_ti: 409 __table_instance_destroy(new_ti); 410 return -ENOMEM; 411} 412 413static u32 flow_hash(const struct sw_flow_key *key, 414 const struct sw_flow_key_range *range) 415{ 416 int key_start = range->start; 417 int key_end = range->end; 418 const u32 *hash_key = (const u32 *)((const u8 *)key + key_start); 419 int hash_u32s = (key_end - key_start) >> 2; 420 421 /* Make sure number of hash bytes are multiple of u32. */ 422 BUILD_BUG_ON(sizeof(long) % sizeof(u32)); 423 424 return jhash2(hash_key, hash_u32s, 0); 425} 426 427static int flow_key_start(const struct sw_flow_key *key) 428{ 429 if (key->tun_key.ipv4_dst) 430 return 0; 431 else 432 return rounddown(offsetof(struct sw_flow_key, phy), 433 sizeof(long)); 434} 435 436static bool cmp_key(const struct sw_flow_key *key1, 437 const struct sw_flow_key *key2, 438 int key_start, int key_end) 439{ 440 const long *cp1 = (const long *)((const u8 *)key1 + key_start); 441 const long *cp2 = (const long *)((const u8 *)key2 + key_start); 442 long diffs = 0; 443 int i; 444 445 for (i = key_start; i < key_end; i += sizeof(long)) 446 diffs |= *cp1++ ^ *cp2++; 447 448 return diffs == 0; 449} 450 451static bool flow_cmp_masked_key(const struct sw_flow *flow, 452 const struct sw_flow_key *key, 453 const struct sw_flow_key_range *range) 454{ 455 return cmp_key(&flow->key, key, range->start, range->end); 456} 457 458static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow, 459 const struct sw_flow_match *match) 460{ 461 struct sw_flow_key *key = match->key; 462 int key_start = flow_key_start(key); 463 int key_end = match->range.end; 464 465 BUG_ON(ovs_identifier_is_ufid(&flow->id)); 466 return cmp_key(flow->id.unmasked_key, key, key_start, key_end); 467} 468 469static struct sw_flow *masked_flow_lookup(struct table_instance *ti, 470 const struct sw_flow_key *unmasked, 471 const struct sw_flow_mask *mask) 472{ 473 struct sw_flow *flow; 474 struct hlist_head *head; 475 u32 hash; 476 struct sw_flow_key masked_key; 477 478 ovs_flow_mask_key(&masked_key, unmasked, false, mask); 479 hash = flow_hash(&masked_key, &mask->range); 480 head = find_bucket(ti, hash); 481 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) { 482 if (flow->mask == mask && flow->flow_table.hash == hash && 483 flow_cmp_masked_key(flow, &masked_key, &mask->range)) 484 return flow; 485 } 486 return NULL; 487} 488 489struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl, 490 const struct sw_flow_key *key, 491 u32 *n_mask_hit) 492{ 493 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 494 struct sw_flow_mask *mask; 495 struct sw_flow *flow; 496 497 *n_mask_hit = 0; 498 list_for_each_entry_rcu(mask, &tbl->mask_list, list) { 499 (*n_mask_hit)++; 500 flow = masked_flow_lookup(ti, key, mask); 501 if (flow) /* Found */ 502 return flow; 503 } 504 return NULL; 505} 506 507struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl, 508 const struct sw_flow_key *key) 509{ 510 u32 __always_unused n_mask_hit; 511 512 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit); 513} 514 515struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl, 516 const struct sw_flow_match *match) 517{ 518 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti); 519 struct sw_flow_mask *mask; 520 struct sw_flow *flow; 521 522 /* Always called under ovs-mutex. */ 523 list_for_each_entry(mask, &tbl->mask_list, list) { 524 flow = masked_flow_lookup(ti, match->key, mask); 525 if (flow && ovs_identifier_is_key(&flow->id) && 526 ovs_flow_cmp_unmasked_key(flow, match)) 527 return flow; 528 } 529 return NULL; 530} 531 532static u32 ufid_hash(const struct sw_flow_id *sfid) 533{ 534 return jhash(sfid->ufid, sfid->ufid_len, 0); 535} 536 537static bool ovs_flow_cmp_ufid(const struct sw_flow *flow, 538 const struct sw_flow_id *sfid) 539{ 540 if (flow->id.ufid_len != sfid->ufid_len) 541 return false; 542 543 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len); 544} 545 546bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match) 547{ 548 if (ovs_identifier_is_ufid(&flow->id)) 549 return flow_cmp_masked_key(flow, match->key, &match->range); 550 551 return ovs_flow_cmp_unmasked_key(flow, match); 552} 553 554struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl, 555 const struct sw_flow_id *ufid) 556{ 557 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti); 558 struct sw_flow *flow; 559 struct hlist_head *head; 560 u32 hash; 561 562 hash = ufid_hash(ufid); 563 head = find_bucket(ti, hash); 564 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) { 565 if (flow->ufid_table.hash == hash && 566 ovs_flow_cmp_ufid(flow, ufid)) 567 return flow; 568 } 569 return NULL; 570} 571 572int ovs_flow_tbl_num_masks(const struct flow_table *table) 573{ 574 struct sw_flow_mask *mask; 575 int num = 0; 576 577 list_for_each_entry(mask, &table->mask_list, list) 578 num++; 579 580 return num; 581} 582 583static struct table_instance *table_instance_expand(struct table_instance *ti, 584 bool ufid) 585{ 586 return table_instance_rehash(ti, ti->n_buckets * 2, ufid); 587} 588 589/* Remove 'mask' from the mask list, if it is not needed any more. */ 590static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask) 591{ 592 if (mask) { 593 /* ovs-lock is required to protect mask-refcount and 594 * mask list. 595 */ 596 ASSERT_OVSL(); 597 BUG_ON(!mask->ref_count); 598 mask->ref_count--; 599 600 if (!mask->ref_count) { 601 list_del_rcu(&mask->list); 602 kfree_rcu(mask, rcu); 603 } 604 } 605} 606 607/* Must be called with OVS mutex held. */ 608void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow) 609{ 610 struct table_instance *ti = ovsl_dereference(table->ti); 611 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti); 612 613 BUG_ON(table->count == 0); 614 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]); 615 table->count--; 616 if (ovs_identifier_is_ufid(&flow->id)) { 617 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]); 618 table->ufid_count--; 619 } 620 621 /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be 622 * accessible as long as the RCU read lock is held. 623 */ 624 flow_mask_remove(table, flow->mask); 625} 626 627static struct sw_flow_mask *mask_alloc(void) 628{ 629 struct sw_flow_mask *mask; 630 631 mask = kmalloc(sizeof(*mask), GFP_KERNEL); 632 if (mask) 633 mask->ref_count = 1; 634 635 return mask; 636} 637 638static bool mask_equal(const struct sw_flow_mask *a, 639 const struct sw_flow_mask *b) 640{ 641 const u8 *a_ = (const u8 *)&a->key + a->range.start; 642 const u8 *b_ = (const u8 *)&b->key + b->range.start; 643 644 return (a->range.end == b->range.end) 645 && (a->range.start == b->range.start) 646 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0); 647} 648 649static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl, 650 const struct sw_flow_mask *mask) 651{ 652 struct list_head *ml; 653 654 list_for_each(ml, &tbl->mask_list) { 655 struct sw_flow_mask *m; 656 m = container_of(ml, struct sw_flow_mask, list); 657 if (mask_equal(mask, m)) 658 return m; 659 } 660 661 return NULL; 662} 663 664/* Add 'mask' into the mask list, if it is not already there. */ 665static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow, 666 const struct sw_flow_mask *new) 667{ 668 struct sw_flow_mask *mask; 669 mask = flow_mask_find(tbl, new); 670 if (!mask) { 671 /* Allocate a new mask if none exsits. */ 672 mask = mask_alloc(); 673 if (!mask) 674 return -ENOMEM; 675 mask->key = new->key; 676 mask->range = new->range; 677 list_add_rcu(&mask->list, &tbl->mask_list); 678 } else { 679 BUG_ON(!mask->ref_count); 680 mask->ref_count++; 681 } 682 683 flow->mask = mask; 684 return 0; 685} 686 687/* Must be called with OVS mutex held. */ 688static void flow_key_insert(struct flow_table *table, struct sw_flow *flow) 689{ 690 struct table_instance *new_ti = NULL; 691 struct table_instance *ti; 692 693 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range); 694 ti = ovsl_dereference(table->ti); 695 table_instance_insert(ti, flow); 696 table->count++; 697 698 /* Expand table, if necessary, to make room. */ 699 if (table->count > ti->n_buckets) 700 new_ti = table_instance_expand(ti, false); 701 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL)) 702 new_ti = table_instance_rehash(ti, ti->n_buckets, false); 703 704 if (new_ti) { 705 rcu_assign_pointer(table->ti, new_ti); 706 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 707 table->last_rehash = jiffies; 708 } 709} 710 711/* Must be called with OVS mutex held. */ 712static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow) 713{ 714 struct table_instance *ti; 715 716 flow->ufid_table.hash = ufid_hash(&flow->id); 717 ti = ovsl_dereference(table->ufid_ti); 718 ufid_table_instance_insert(ti, flow); 719 table->ufid_count++; 720 721 /* Expand table, if necessary, to make room. */ 722 if (table->ufid_count > ti->n_buckets) { 723 struct table_instance *new_ti; 724 725 new_ti = table_instance_expand(ti, true); 726 if (new_ti) { 727 rcu_assign_pointer(table->ufid_ti, new_ti); 728 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb); 729 } 730 } 731} 732 733/* Must be called with OVS mutex held. */ 734int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow, 735 const struct sw_flow_mask *mask) 736{ 737 int err; 738 739 err = flow_mask_insert(table, flow, mask); 740 if (err) 741 return err; 742 flow_key_insert(table, flow); 743 if (ovs_identifier_is_ufid(&flow->id)) 744 flow_ufid_insert(table, flow); 745 746 return 0; 747} 748 749/* Initializes the flow module. 750 * Returns zero if successful or a negative error code. */ 751int ovs_flow_init(void) 752{ 753 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long)); 754 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long)); 755 756 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow) 757 + (num_possible_nodes() 758 * sizeof(struct flow_stats *)), 759 0, 0, NULL); 760 if (flow_cache == NULL) 761 return -ENOMEM; 762 763 flow_stats_cache 764 = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats), 765 0, SLAB_HWCACHE_ALIGN, NULL); 766 if (flow_stats_cache == NULL) { 767 kmem_cache_destroy(flow_cache); 768 flow_cache = NULL; 769 return -ENOMEM; 770 } 771 772 return 0; 773} 774 775/* Uninitializes the flow module. */ 776void ovs_flow_exit(void) 777{ 778 kmem_cache_destroy(flow_stats_cache); 779 kmem_cache_destroy(flow_cache); 780} 781