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/jhash.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(void)
79 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
81 return ERR_PTR(-ENOMEM);
83 spin_lock_init(&flow->lock);
90 int ovs_flow_tbl_count(struct flow_table *table)
95 static struct flex_array *alloc_buckets(unsigned int n_buckets)
97 struct flex_array *buckets;
100 buckets = flex_array_alloc(sizeof(struct hlist_head),
101 n_buckets, GFP_KERNEL);
105 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
107 flex_array_free(buckets);
111 for (i = 0; i < n_buckets; i++)
112 INIT_HLIST_HEAD((struct hlist_head *)
113 flex_array_get(buckets, i));
118 static void flow_free(struct sw_flow *flow)
120 kfree((struct sf_flow_acts __force *)flow->sf_acts);
121 kmem_cache_free(flow_cache, flow);
124 static void rcu_free_flow_callback(struct rcu_head *rcu)
126 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
131 void ovs_flow_free(struct sw_flow *flow, bool deferred)
136 ovs_sw_flow_mask_del_ref(flow->mask, deferred);
139 call_rcu(&flow->rcu, rcu_free_flow_callback);
144 static void free_buckets(struct flex_array *buckets)
146 flex_array_free(buckets);
149 static void __table_instance_destroy(struct table_instance *ti)
156 for (i = 0; i < ti->n_buckets; i++) {
157 struct sw_flow *flow;
158 struct hlist_head *head = flex_array_get(ti->buckets, i);
159 struct hlist_node *n;
160 int ver = ti->node_ver;
162 hlist_for_each_entry_safe(flow, n, head, hash_node[ver]) {
163 hlist_del(&flow->hash_node[ver]);
164 ovs_flow_free(flow, false);
169 free_buckets(ti->buckets);
173 static struct table_instance *table_instance_alloc(int new_size)
175 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
180 ti->buckets = alloc_buckets(new_size);
186 ti->n_buckets = new_size;
188 ti->keep_flows = false;
189 get_random_bytes(&ti->hash_seed, sizeof(u32));
194 int ovs_flow_tbl_init(struct flow_table *table)
196 struct table_instance *ti;
198 ti = table_instance_alloc(TBL_MIN_BUCKETS);
203 rcu_assign_pointer(table->ti, ti);
204 INIT_LIST_HEAD(&table->mask_list);
205 table->last_rehash = jiffies;
210 static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
212 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
214 __table_instance_destroy(ti);
217 static void table_instance_destroy(struct table_instance *ti, bool deferred)
223 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
225 __table_instance_destroy(ti);
228 void ovs_flow_tbl_destroy(struct flow_table *table, bool deferred)
230 struct table_instance *ti = ovsl_dereference(table->ti);
232 table_instance_destroy(ti, deferred);
235 struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
236 u32 *bucket, u32 *last)
238 struct sw_flow *flow;
239 struct hlist_head *head;
244 while (*bucket < ti->n_buckets) {
246 head = flex_array_get(ti->buckets, *bucket);
247 hlist_for_each_entry_rcu(flow, head, hash_node[ver]) {
262 static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
264 hash = jhash_1word(hash, ti->hash_seed);
265 return flex_array_get(ti->buckets,
266 (hash & (ti->n_buckets - 1)));
269 static void table_instance_insert(struct table_instance *ti, struct sw_flow *flow)
271 struct hlist_head *head;
273 head = find_bucket(ti, flow->hash);
274 hlist_add_head_rcu(&flow->hash_node[ti->node_ver], head);
277 static void flow_table_copy_flows(struct table_instance *old,
278 struct table_instance *new)
283 old_ver = old->node_ver;
284 new->node_ver = !old_ver;
286 /* Insert in new table. */
287 for (i = 0; i < old->n_buckets; i++) {
288 struct sw_flow *flow;
289 struct hlist_head *head;
291 head = flex_array_get(old->buckets, i);
293 hlist_for_each_entry(flow, head, hash_node[old_ver])
294 table_instance_insert(new, flow);
297 old->keep_flows = true;
300 static struct table_instance *table_instance_rehash(struct table_instance *ti,
303 struct table_instance *new_ti;
305 new_ti = table_instance_alloc(n_buckets);
307 return ERR_PTR(-ENOMEM);
309 flow_table_copy_flows(ti, new_ti);
314 int ovs_flow_tbl_flush(struct flow_table *flow_table)
316 struct table_instance *old_ti;
317 struct table_instance *new_ti;
319 old_ti = ovsl_dereference(flow_table->ti);
320 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
324 rcu_assign_pointer(flow_table->ti, new_ti);
325 flow_table->last_rehash = jiffies;
326 flow_table->count = 0;
328 table_instance_destroy(old_ti, true);
332 static u32 flow_hash(const struct sw_flow_key *key, int key_start,
335 u32 *hash_key = (u32 *)((u8 *)key + key_start);
336 int hash_u32s = (key_end - key_start) >> 2;
338 /* Make sure number of hash bytes are multiple of u32. */
339 BUILD_BUG_ON(sizeof(long) % sizeof(u32));
341 return jhash2(hash_key, hash_u32s, 0);
344 static int flow_key_start(const struct sw_flow_key *key)
346 if (key->tun_key.ipv4_dst)
349 return rounddown(offsetof(struct sw_flow_key, phy),
353 static bool cmp_key(const struct sw_flow_key *key1,
354 const struct sw_flow_key *key2,
355 int key_start, int key_end)
357 const long *cp1 = (long *)((u8 *)key1 + key_start);
358 const long *cp2 = (long *)((u8 *)key2 + key_start);
362 for (i = key_start; i < key_end; i += sizeof(long))
363 diffs |= *cp1++ ^ *cp2++;
368 static bool flow_cmp_masked_key(const struct sw_flow *flow,
369 const struct sw_flow_key *key,
370 int key_start, int key_end)
372 return cmp_key(&flow->key, key, key_start, key_end);
375 bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
376 struct sw_flow_match *match)
378 struct sw_flow_key *key = match->key;
379 int key_start = flow_key_start(key);
380 int key_end = match->range.end;
382 return cmp_key(&flow->unmasked_key, key, key_start, key_end);
385 static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
386 const struct sw_flow_key *unmasked,
387 struct sw_flow_mask *mask)
389 struct sw_flow *flow;
390 struct hlist_head *head;
391 int key_start = mask->range.start;
392 int key_end = mask->range.end;
394 struct sw_flow_key masked_key;
396 ovs_flow_mask_key(&masked_key, unmasked, mask);
397 hash = flow_hash(&masked_key, key_start, key_end);
398 head = find_bucket(ti, hash);
399 hlist_for_each_entry_rcu(flow, head, hash_node[ti->node_ver]) {
400 if (flow->mask == mask &&
401 flow_cmp_masked_key(flow, &masked_key,
408 struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
409 const struct sw_flow_key *key)
411 struct table_instance *ti = rcu_dereference(tbl->ti);
412 struct sw_flow_mask *mask;
413 struct sw_flow *flow;
415 list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
416 flow = masked_flow_lookup(ti, key, mask);
417 if (flow) /* Found */
423 static struct table_instance *table_instance_expand(struct table_instance *ti)
425 return table_instance_rehash(ti, ti->n_buckets * 2);
428 void ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow)
430 struct table_instance *ti = NULL;
431 struct table_instance *new_ti = NULL;
433 ti = ovsl_dereference(table->ti);
435 /* Expand table, if necessary, to make room. */
436 if (table->count > ti->n_buckets)
437 new_ti = table_instance_expand(ti);
438 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
439 new_ti = table_instance_rehash(ti, ti->n_buckets);
441 if (new_ti && !IS_ERR(new_ti)) {
442 rcu_assign_pointer(table->ti, new_ti);
443 ovs_flow_tbl_destroy(table, true);
444 ti = ovsl_dereference(table->ti);
445 table->last_rehash = jiffies;
448 flow->hash = flow_hash(&flow->key, flow->mask->range.start,
449 flow->mask->range.end);
450 table_instance_insert(ti, flow);
454 void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
456 struct table_instance *ti = ovsl_dereference(table->ti);
458 BUG_ON(table->count == 0);
459 hlist_del_rcu(&flow->hash_node[ti->node_ver]);
463 struct sw_flow_mask *ovs_sw_flow_mask_alloc(void)
465 struct sw_flow_mask *mask;
467 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
474 void ovs_sw_flow_mask_add_ref(struct sw_flow_mask *mask)
479 static void rcu_free_sw_flow_mask_cb(struct rcu_head *rcu)
481 struct sw_flow_mask *mask = container_of(rcu, struct sw_flow_mask, rcu);
486 void ovs_sw_flow_mask_del_ref(struct sw_flow_mask *mask, bool deferred)
491 BUG_ON(!mask->ref_count);
494 if (!mask->ref_count) {
495 list_del_rcu(&mask->list);
497 call_rcu(&mask->rcu, rcu_free_sw_flow_mask_cb);
503 static bool mask_equal(const struct sw_flow_mask *a,
504 const struct sw_flow_mask *b)
506 u8 *a_ = (u8 *)&a->key + a->range.start;
507 u8 *b_ = (u8 *)&b->key + b->range.start;
509 return (a->range.end == b->range.end)
510 && (a->range.start == b->range.start)
511 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
514 struct sw_flow_mask *ovs_sw_flow_mask_find(const struct flow_table *tbl,
515 const struct sw_flow_mask *mask)
517 struct list_head *ml;
519 list_for_each(ml, &tbl->mask_list) {
520 struct sw_flow_mask *m;
521 m = container_of(ml, struct sw_flow_mask, list);
522 if (mask_equal(mask, m))
530 * add a new mask into the mask list.
531 * The caller needs to make sure that 'mask' is not the same
532 * as any masks that are already on the list.
534 void ovs_sw_flow_mask_insert(struct flow_table *tbl, struct sw_flow_mask *mask)
536 list_add_rcu(&mask->list, &tbl->mask_list);
539 /* Initializes the flow module.
540 * Returns zero if successful or a negative error code. */
541 int ovs_flow_init(void)
543 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
544 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
546 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow), 0,
548 if (flow_cache == NULL)
554 /* Uninitializes the flow module. */
555 void ovs_flow_exit(void)
557 kmem_cache_destroy(flow_cache);