2 * Copyright (c) 2007-2013 Nicira, Inc.
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.
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.
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
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/hash.h>
29 #include <linux/jiffies.h>
30 #include <linux/llc.h>
31 #include <linux/module.h>
33 #include <linux/rcupdate.h>
34 #include <linux/if_arp.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>
45 #include <net/ndisc.h>
49 #define TBL_MIN_BUCKETS 1024
50 #define REHASH_INTERVAL (10 * 60 * HZ)
52 static struct kmem_cache *flow_cache;
53 struct kmem_cache *flow_stats_cache __read_mostly;
55 static u16 range_n_bytes(const struct sw_flow_key_range *range)
57 return range->end - range->start;
60 void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
61 const struct sw_flow_mask *mask)
63 const long *m = (const long *)((const u8 *)&mask->key +
65 const long *s = (const long *)((const u8 *)src +
67 long *d = (long *)((u8 *)dst + mask->range.start);
70 /* The memory outside of the 'mask->range' are not set since
71 * further operations on 'dst' only uses contents within
74 for (i = 0; i < range_n_bytes(&mask->range); i += sizeof(long))
78 struct sw_flow *ovs_flow_alloc(void)
81 struct flow_stats *stats;
84 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
86 return ERR_PTR(-ENOMEM);
90 flow->stats_last_writer = NUMA_NO_NODE;
92 /* Initialize the default stat node. */
93 stats = kmem_cache_alloc_node(flow_stats_cache,
94 GFP_KERNEL | __GFP_ZERO, 0);
98 spin_lock_init(&stats->lock);
100 RCU_INIT_POINTER(flow->stats[0], stats);
104 RCU_INIT_POINTER(flow->stats[node], NULL);
108 kmem_cache_free(flow_cache, flow);
109 return ERR_PTR(-ENOMEM);
112 int ovs_flow_tbl_count(struct flow_table *table)
117 static struct flex_array *alloc_buckets(unsigned int n_buckets)
119 struct flex_array *buckets;
122 buckets = flex_array_alloc(sizeof(struct hlist_head),
123 n_buckets, GFP_KERNEL);
127 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
129 flex_array_free(buckets);
133 for (i = 0; i < n_buckets; i++)
134 INIT_HLIST_HEAD((struct hlist_head *)
135 flex_array_get(buckets, i));
140 static void flow_free(struct sw_flow *flow)
144 kfree((struct sf_flow_acts __force *)flow->sf_acts);
146 if (flow->stats[node])
147 kmem_cache_free(flow_stats_cache,
148 (struct flow_stats __force *)flow->stats[node]);
149 kmem_cache_free(flow_cache, flow);
152 static void rcu_free_flow_callback(struct rcu_head *rcu)
154 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
159 static void rcu_free_sw_flow_mask_cb(struct rcu_head *rcu)
161 struct sw_flow_mask *mask = container_of(rcu, struct sw_flow_mask, rcu);
166 void ovs_flow_free(struct sw_flow *flow, bool deferred)
172 struct sw_flow_mask *mask = flow->mask;
174 /* ovs-lock is required to protect mask-refcount and
178 BUG_ON(!mask->ref_count);
181 if (!mask->ref_count) {
182 list_del_rcu(&mask->list);
184 call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
191 call_rcu(&flow->rcu, rcu_free_flow_callback);
196 static void free_buckets(struct flex_array *buckets)
198 flex_array_free(buckets);
202 static void __table_instance_destroy(struct table_instance *ti)
204 free_buckets(ti->buckets);
208 static struct table_instance *table_instance_alloc(int new_size)
210 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
215 ti->buckets = alloc_buckets(new_size);
221 ti->n_buckets = new_size;
223 ti->keep_flows = false;
224 get_random_bytes(&ti->hash_seed, sizeof(u32));
229 int ovs_flow_tbl_init(struct flow_table *table)
231 struct table_instance *ti;
233 ti = table_instance_alloc(TBL_MIN_BUCKETS);
238 rcu_assign_pointer(table->ti, ti);
239 INIT_LIST_HEAD(&table->mask_list);
240 table->last_rehash = jiffies;
245 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
247 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
249 __table_instance_destroy(ti);
252 static void table_instance_destroy(struct table_instance *ti, bool deferred)
262 for (i = 0; i < ti->n_buckets; i++) {
263 struct sw_flow *flow;
264 struct hlist_head *head = flex_array_get(ti->buckets, i);
265 struct hlist_node *n;
266 int ver = ti->node_ver;
268 hlist_for_each_entry_safe(flow, n, head, hash_node[ver]) {
269 hlist_del_rcu(&flow->hash_node[ver]);
270 ovs_flow_free(flow, deferred);
276 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
278 __table_instance_destroy(ti);
281 void ovs_flow_tbl_destroy(struct flow_table *table, bool deferred)
283 struct table_instance *ti = ovsl_dereference(table->ti);
285 table_instance_destroy(ti, deferred);
288 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
289 u32 *bucket, u32 *last)
291 struct sw_flow *flow;
292 struct hlist_head *head;
297 while (*bucket < ti->n_buckets) {
299 head = flex_array_get(ti->buckets, *bucket);
300 hlist_for_each_entry_rcu(flow, head, hash_node[ver]) {
315 static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
317 hash = jhash_1word(hash, ti->hash_seed);
318 return flex_array_get(ti->buckets,
319 (hash & (ti->n_buckets - 1)));
322 static void table_instance_insert(struct table_instance *ti, struct sw_flow *flow)
324 struct hlist_head *head;
326 head = find_bucket(ti, flow->hash);
327 hlist_add_head_rcu(&flow->hash_node[ti->node_ver], head);
330 static void flow_table_copy_flows(struct table_instance *old,
331 struct table_instance *new)
336 old_ver = old->node_ver;
337 new->node_ver = !old_ver;
339 /* Insert in new table. */
340 for (i = 0; i < old->n_buckets; i++) {
341 struct sw_flow *flow;
342 struct hlist_head *head;
344 head = flex_array_get(old->buckets, i);
346 hlist_for_each_entry(flow, head, hash_node[old_ver])
347 table_instance_insert(new, flow);
350 old->keep_flows = true;
353 static struct table_instance *table_instance_rehash(struct table_instance *ti,
356 struct table_instance *new_ti;
358 new_ti = table_instance_alloc(n_buckets);
362 flow_table_copy_flows(ti, new_ti);
367 int ovs_flow_tbl_flush(struct flow_table *flow_table)
369 struct table_instance *old_ti;
370 struct table_instance *new_ti;
372 old_ti = ovsl_dereference(flow_table->ti);
373 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
377 rcu_assign_pointer(flow_table->ti, new_ti);
378 flow_table->last_rehash = jiffies;
379 flow_table->count = 0;
381 table_instance_destroy(old_ti, true);
385 static u32 flow_hash(const struct sw_flow_key *key, int key_start,
388 const u32 *hash_key = (const u32 *)((const u8 *)key + key_start);
389 int hash_u32s = (key_end - key_start) >> 2;
391 /* Make sure number of hash bytes are multiple of u32. */
392 BUILD_BUG_ON(sizeof(long) % sizeof(u32));
394 return arch_fast_hash2(hash_key, hash_u32s, 0);
397 static int flow_key_start(const struct sw_flow_key *key)
399 if (key->tun_key.ipv4_dst)
402 return rounddown(offsetof(struct sw_flow_key, phy),
406 static bool cmp_key(const struct sw_flow_key *key1,
407 const struct sw_flow_key *key2,
408 int key_start, int key_end)
410 const long *cp1 = (const long *)((const u8 *)key1 + key_start);
411 const long *cp2 = (const long *)((const u8 *)key2 + key_start);
415 for (i = key_start; i < key_end; i += sizeof(long))
416 diffs |= *cp1++ ^ *cp2++;
421 static bool flow_cmp_masked_key(const struct sw_flow *flow,
422 const struct sw_flow_key *key,
423 int key_start, int key_end)
425 return cmp_key(&flow->key, key, key_start, key_end);
428 bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
429 struct sw_flow_match *match)
431 struct sw_flow_key *key = match->key;
432 int key_start = flow_key_start(key);
433 int key_end = match->range.end;
435 return cmp_key(&flow->unmasked_key, key, key_start, key_end);
438 static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
439 const struct sw_flow_key *unmasked,
440 struct sw_flow_mask *mask)
442 struct sw_flow *flow;
443 struct hlist_head *head;
444 int key_start = mask->range.start;
445 int key_end = mask->range.end;
447 struct sw_flow_key masked_key;
449 ovs_flow_mask_key(&masked_key, unmasked, mask);
450 hash = flow_hash(&masked_key, key_start, key_end);
451 head = find_bucket(ti, hash);
452 hlist_for_each_entry_rcu(flow, head, hash_node[ti->node_ver]) {
453 if (flow->mask == mask && flow->hash == hash &&
454 flow_cmp_masked_key(flow, &masked_key,
461 struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
462 const struct sw_flow_key *key,
465 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
466 struct sw_flow_mask *mask;
467 struct sw_flow *flow;
470 list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
472 flow = masked_flow_lookup(ti, key, mask);
473 if (flow) /* Found */
479 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
480 const struct sw_flow_key *key)
482 u32 __always_unused n_mask_hit;
484 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
487 int ovs_flow_tbl_num_masks(const struct flow_table *table)
489 struct sw_flow_mask *mask;
492 list_for_each_entry(mask, &table->mask_list, list)
498 static struct table_instance *table_instance_expand(struct table_instance *ti)
500 return table_instance_rehash(ti, ti->n_buckets * 2);
503 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
505 struct table_instance *ti = ovsl_dereference(table->ti);
507 BUG_ON(table->count == 0);
508 hlist_del_rcu(&flow->hash_node[ti->node_ver]);
512 static struct sw_flow_mask *mask_alloc(void)
514 struct sw_flow_mask *mask;
516 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
523 static bool mask_equal(const struct sw_flow_mask *a,
524 const struct sw_flow_mask *b)
526 const u8 *a_ = (const u8 *)&a->key + a->range.start;
527 const u8 *b_ = (const u8 *)&b->key + b->range.start;
529 return (a->range.end == b->range.end)
530 && (a->range.start == b->range.start)
531 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
534 static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
535 const struct sw_flow_mask *mask)
537 struct list_head *ml;
539 list_for_each(ml, &tbl->mask_list) {
540 struct sw_flow_mask *m;
541 m = container_of(ml, struct sw_flow_mask, list);
542 if (mask_equal(mask, m))
549 /* Add 'mask' into the mask list, if it is not already there. */
550 static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
551 struct sw_flow_mask *new)
553 struct sw_flow_mask *mask;
554 mask = flow_mask_find(tbl, new);
556 /* Allocate a new mask if none exsits. */
560 mask->key = new->key;
561 mask->range = new->range;
562 list_add_rcu(&mask->list, &tbl->mask_list);
564 BUG_ON(!mask->ref_count);
572 int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
573 struct sw_flow_mask *mask)
575 struct table_instance *new_ti = NULL;
576 struct table_instance *ti;
579 err = flow_mask_insert(table, flow, mask);
583 flow->hash = flow_hash(&flow->key, flow->mask->range.start,
584 flow->mask->range.end);
585 ti = ovsl_dereference(table->ti);
586 table_instance_insert(ti, flow);
589 /* Expand table, if necessary, to make room. */
590 if (table->count > ti->n_buckets)
591 new_ti = table_instance_expand(ti);
592 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
593 new_ti = table_instance_rehash(ti, ti->n_buckets);
596 rcu_assign_pointer(table->ti, new_ti);
597 table_instance_destroy(ti, true);
598 table->last_rehash = jiffies;
603 /* Initializes the flow module.
604 * Returns zero if successful or a negative error code. */
605 int ovs_flow_init(void)
607 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
608 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
610 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
611 + (num_possible_nodes()
612 * sizeof(struct flow_stats *)),
614 if (flow_cache == NULL)
618 = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats),
619 0, SLAB_HWCACHE_ALIGN, NULL);
620 if (flow_stats_cache == NULL) {
621 kmem_cache_destroy(flow_cache);
629 /* Uninitializes the flow module. */
630 void ovs_flow_exit(void)
632 kmem_cache_destroy(flow_stats_cache);
633 kmem_cache_destroy(flow_cache);