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;
54 static u16 range_n_bytes(const struct sw_flow_key_range *range)
56 return range->end - range->start;
59 void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
60 const struct sw_flow_mask *mask)
62 const long *m = (long *)((u8 *)&mask->key + mask->range.start);
63 const long *s = (long *)((u8 *)src + mask->range.start);
64 long *d = (long *)((u8 *)dst + mask->range.start);
67 /* The memory outside of the 'mask->range' are not set since
68 * further operations on 'dst' only uses contents within
71 for (i = 0; i < range_n_bytes(&mask->range); i += sizeof(long))
75 struct sw_flow *ovs_flow_alloc(bool percpu_stats)
80 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
82 return ERR_PTR(-ENOMEM);
87 flow->stats.is_percpu = percpu_stats;
90 flow->stats.stat = kzalloc(sizeof(*flow->stats.stat), GFP_KERNEL);
91 if (!flow->stats.stat)
94 spin_lock_init(&flow->stats.stat->lock);
96 flow->stats.cpu_stats = alloc_percpu(struct flow_stats);
97 if (!flow->stats.cpu_stats)
100 for_each_possible_cpu(cpu) {
101 struct flow_stats *cpu_stats;
103 cpu_stats = per_cpu_ptr(flow->stats.cpu_stats, cpu);
104 spin_lock_init(&cpu_stats->lock);
110 return ERR_PTR(-ENOMEM);
113 int ovs_flow_tbl_count(struct flow_table *table)
118 static struct flex_array *alloc_buckets(unsigned int n_buckets)
120 struct flex_array *buckets;
123 buckets = flex_array_alloc(sizeof(struct hlist_head),
124 n_buckets, GFP_KERNEL);
128 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
130 flex_array_free(buckets);
134 for (i = 0; i < n_buckets; i++)
135 INIT_HLIST_HEAD((struct hlist_head *)
136 flex_array_get(buckets, i));
141 static void flow_free(struct sw_flow *flow)
143 kfree((struct sf_flow_acts __force *)flow->sf_acts);
144 if (flow->stats.is_percpu)
145 free_percpu(flow->stats.cpu_stats);
147 kfree(flow->stats.stat);
148 kmem_cache_free(flow_cache, flow);
151 static void rcu_free_flow_callback(struct rcu_head *rcu)
153 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
158 static void rcu_free_sw_flow_mask_cb(struct rcu_head *rcu)
160 struct sw_flow_mask *mask = container_of(rcu, struct sw_flow_mask, rcu);
165 static void flow_mask_del_ref(struct sw_flow_mask *mask, bool deferred)
170 BUG_ON(!mask->ref_count);
173 if (!mask->ref_count) {
174 list_del_rcu(&mask->list);
176 call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
182 void ovs_flow_free(struct sw_flow *flow, bool deferred)
187 flow_mask_del_ref(flow->mask, deferred);
190 call_rcu(&flow->rcu, rcu_free_flow_callback);
195 static void free_buckets(struct flex_array *buckets)
197 flex_array_free(buckets);
200 static void __table_instance_destroy(struct table_instance *ti)
207 for (i = 0; i < ti->n_buckets; i++) {
208 struct sw_flow *flow;
209 struct hlist_head *head = flex_array_get(ti->buckets, i);
210 struct hlist_node *n;
211 int ver = ti->node_ver;
213 hlist_for_each_entry_safe(flow, n, head, hash_node[ver]) {
214 hlist_del(&flow->hash_node[ver]);
215 ovs_flow_free(flow, false);
220 free_buckets(ti->buckets);
224 static struct table_instance *table_instance_alloc(int new_size)
226 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
231 ti->buckets = alloc_buckets(new_size);
237 ti->n_buckets = new_size;
239 ti->keep_flows = false;
240 get_random_bytes(&ti->hash_seed, sizeof(u32));
245 int ovs_flow_tbl_init(struct flow_table *table)
247 struct table_instance *ti;
249 ti = table_instance_alloc(TBL_MIN_BUCKETS);
254 rcu_assign_pointer(table->ti, ti);
255 INIT_LIST_HEAD(&table->mask_list);
256 table->last_rehash = jiffies;
261 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
263 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
265 __table_instance_destroy(ti);
268 static void table_instance_destroy(struct table_instance *ti, bool deferred)
274 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
276 __table_instance_destroy(ti);
279 void ovs_flow_tbl_destroy(struct flow_table *table)
281 struct table_instance *ti = ovsl_dereference(table->ti);
283 table_instance_destroy(ti, false);
286 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
287 u32 *bucket, u32 *last)
289 struct sw_flow *flow;
290 struct hlist_head *head;
295 while (*bucket < ti->n_buckets) {
297 head = flex_array_get(ti->buckets, *bucket);
298 hlist_for_each_entry_rcu(flow, head, hash_node[ver]) {
313 static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
315 hash = jhash_1word(hash, ti->hash_seed);
316 return flex_array_get(ti->buckets,
317 (hash & (ti->n_buckets - 1)));
320 static void table_instance_insert(struct table_instance *ti, struct sw_flow *flow)
322 struct hlist_head *head;
324 head = find_bucket(ti, flow->hash);
325 hlist_add_head_rcu(&flow->hash_node[ti->node_ver], head);
328 static void flow_table_copy_flows(struct table_instance *old,
329 struct table_instance *new)
334 old_ver = old->node_ver;
335 new->node_ver = !old_ver;
337 /* Insert in new table. */
338 for (i = 0; i < old->n_buckets; i++) {
339 struct sw_flow *flow;
340 struct hlist_head *head;
342 head = flex_array_get(old->buckets, i);
344 hlist_for_each_entry(flow, head, hash_node[old_ver])
345 table_instance_insert(new, flow);
348 old->keep_flows = true;
351 static struct table_instance *table_instance_rehash(struct table_instance *ti,
354 struct table_instance *new_ti;
356 new_ti = table_instance_alloc(n_buckets);
360 flow_table_copy_flows(ti, new_ti);
365 int ovs_flow_tbl_flush(struct flow_table *flow_table)
367 struct table_instance *old_ti;
368 struct table_instance *new_ti;
370 old_ti = ovsl_dereference(flow_table->ti);
371 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
375 rcu_assign_pointer(flow_table->ti, new_ti);
376 flow_table->last_rehash = jiffies;
377 flow_table->count = 0;
379 table_instance_destroy(old_ti, true);
383 static u32 flow_hash(const struct sw_flow_key *key, int key_start,
386 u32 *hash_key = (u32 *)((u8 *)key + key_start);
387 int hash_u32s = (key_end - key_start) >> 2;
389 /* Make sure number of hash bytes are multiple of u32. */
390 BUILD_BUG_ON(sizeof(long) % sizeof(u32));
392 return arch_fast_hash2(hash_key, hash_u32s, 0);
395 static int flow_key_start(const struct sw_flow_key *key)
397 if (key->tun_key.ipv4_dst)
400 return rounddown(offsetof(struct sw_flow_key, phy),
404 static bool cmp_key(const struct sw_flow_key *key1,
405 const struct sw_flow_key *key2,
406 int key_start, int key_end)
408 const long *cp1 = (long *)((u8 *)key1 + key_start);
409 const long *cp2 = (long *)((u8 *)key2 + key_start);
413 for (i = key_start; i < key_end; i += sizeof(long))
414 diffs |= *cp1++ ^ *cp2++;
419 static bool flow_cmp_masked_key(const struct sw_flow *flow,
420 const struct sw_flow_key *key,
421 int key_start, int key_end)
423 return cmp_key(&flow->key, key, key_start, key_end);
426 bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
427 struct sw_flow_match *match)
429 struct sw_flow_key *key = match->key;
430 int key_start = flow_key_start(key);
431 int key_end = match->range.end;
433 return cmp_key(&flow->unmasked_key, key, key_start, key_end);
436 static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
437 const struct sw_flow_key *unmasked,
438 struct sw_flow_mask *mask)
440 struct sw_flow *flow;
441 struct hlist_head *head;
442 int key_start = mask->range.start;
443 int key_end = mask->range.end;
445 struct sw_flow_key masked_key;
447 ovs_flow_mask_key(&masked_key, unmasked, mask);
448 hash = flow_hash(&masked_key, key_start, key_end);
449 head = find_bucket(ti, hash);
450 hlist_for_each_entry_rcu(flow, head, hash_node[ti->node_ver]) {
451 if (flow->mask == mask && flow->hash == hash &&
452 flow_cmp_masked_key(flow, &masked_key,
459 struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
460 const struct sw_flow_key *key,
463 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
464 struct sw_flow_mask *mask;
465 struct sw_flow *flow;
468 list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
470 flow = masked_flow_lookup(ti, key, mask);
471 if (flow) /* Found */
477 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
478 const struct sw_flow_key *key)
480 u32 __always_unused n_mask_hit;
482 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
485 int ovs_flow_tbl_num_masks(const struct flow_table *table)
487 struct sw_flow_mask *mask;
490 list_for_each_entry(mask, &table->mask_list, list)
496 static struct table_instance *table_instance_expand(struct table_instance *ti)
498 return table_instance_rehash(ti, ti->n_buckets * 2);
501 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
503 struct table_instance *ti = ovsl_dereference(table->ti);
505 BUG_ON(table->count == 0);
506 hlist_del_rcu(&flow->hash_node[ti->node_ver]);
510 static struct sw_flow_mask *mask_alloc(void)
512 struct sw_flow_mask *mask;
514 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
521 static void mask_add_ref(struct sw_flow_mask *mask)
526 static bool mask_equal(const struct sw_flow_mask *a,
527 const struct sw_flow_mask *b)
529 u8 *a_ = (u8 *)&a->key + a->range.start;
530 u8 *b_ = (u8 *)&b->key + b->range.start;
532 return (a->range.end == b->range.end)
533 && (a->range.start == b->range.start)
534 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
537 static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
538 const struct sw_flow_mask *mask)
540 struct list_head *ml;
542 list_for_each(ml, &tbl->mask_list) {
543 struct sw_flow_mask *m;
544 m = container_of(ml, struct sw_flow_mask, list);
545 if (mask_equal(mask, m))
552 /* Add 'mask' into the mask list, if it is not already there. */
553 static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
554 struct sw_flow_mask *new)
556 struct sw_flow_mask *mask;
557 mask = flow_mask_find(tbl, new);
559 /* Allocate a new mask if none exsits. */
563 mask->key = new->key;
564 mask->range = new->range;
565 list_add_rcu(&mask->list, &tbl->mask_list);
573 int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
574 struct sw_flow_mask *mask)
576 struct table_instance *new_ti = NULL;
577 struct table_instance *ti;
580 err = flow_mask_insert(table, flow, mask);
584 flow->hash = flow_hash(&flow->key, flow->mask->range.start,
585 flow->mask->range.end);
586 ti = ovsl_dereference(table->ti);
587 table_instance_insert(ti, flow);
590 /* Expand table, if necessary, to make room. */
591 if (table->count > ti->n_buckets)
592 new_ti = table_instance_expand(ti);
593 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
594 new_ti = table_instance_rehash(ti, ti->n_buckets);
597 rcu_assign_pointer(table->ti, new_ti);
598 table_instance_destroy(ti, true);
599 table->last_rehash = jiffies;
604 /* Initializes the flow module.
605 * Returns zero if successful or a negative error code. */
606 int ovs_flow_init(void)
608 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
609 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
611 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
613 if (flow_cache == NULL)
619 /* Uninitializes the flow module. */
620 void ovs_flow_exit(void)
622 kmem_cache_destroy(flow_cache);