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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 "flow_netlink.h"
22#include <linux/uaccess.h>
23#include <linux/netdevice.h>
24#include <linux/etherdevice.h>
25#include <linux/if_ether.h>
26#include <linux/if_vlan.h>
27#include <net/llc_pdu.h>
28#include <linux/kernel.h>
29#include <linux/jhash.h>
30#include <linux/jiffies.h>
31#include <linux/llc.h>
32#include <linux/module.h>
33#include <linux/in.h>
34#include <linux/rcupdate.h>
35#include <linux/cpumask.h>
36#include <linux/if_arp.h>
37#include <linux/ip.h>
38#include <linux/ipv6.h>
39#include <linux/sctp.h>
40#include <linux/tcp.h>
41#include <linux/udp.h>
42#include <linux/icmp.h>
43#include <linux/icmpv6.h>
44#include <linux/rculist.h>
45#include <net/ip.h>
46#include <net/ipv6.h>
47#include <net/ndisc.h>
48
49#define TBL_MIN_BUCKETS 1024
50#define REHASH_INTERVAL (10 * 60 * HZ)
51
52static struct kmem_cache *flow_cache;
53struct kmem_cache *flow_stats_cache __read_mostly;
54
55static u16 range_n_bytes(const struct sw_flow_key_range *range)
56{
57 return range->end - range->start;
58}
59
60void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
61 bool full, const struct sw_flow_mask *mask)
62{
63 int start = full ? 0 : mask->range.start;
64 int len = full ? sizeof *dst : range_n_bytes(&mask->range);
65 const long *m = (const long *)((const u8 *)&mask->key + start);
66 const long *s = (const long *)((const u8 *)src + start);
67 long *d = (long *)((u8 *)dst + start);
68 int i;
69
70 /* If 'full' is true then all of 'dst' is fully initialized. Otherwise,
71 * if 'full' is false the memory outside of the 'mask->range' is left
72 * uninitialized. This can be used as an optimization when further
73 * operations on 'dst' only use contents within 'mask->range'.
74 */
75 for (i = 0; i < len; i += sizeof(long))
76 *d++ = *s++ & *m++;
77}
78
79struct sw_flow *ovs_flow_alloc(void)
80{
81 struct sw_flow *flow;
82 struct flow_stats *stats;
83
84 flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL);
85 if (!flow)
86 return ERR_PTR(-ENOMEM);
87
88 flow->stats_last_writer = -1;
89
90 /* Initialize the default stat node. */
91 stats = kmem_cache_alloc_node(flow_stats_cache,
92 GFP_KERNEL | __GFP_ZERO,
93 node_online(0) ? 0 : NUMA_NO_NODE);
94 if (!stats)
95 goto err;
96
97 spin_lock_init(&stats->lock);
98
99 RCU_INIT_POINTER(flow->stats[0], stats);
100
101 return flow;
102err:
103 kmem_cache_free(flow_cache, flow);
104 return ERR_PTR(-ENOMEM);
105}
106
107int ovs_flow_tbl_count(const struct flow_table *table)
108{
109 return table->count;
110}
111
112static struct flex_array *alloc_buckets(unsigned int n_buckets)
113{
114 struct flex_array *buckets;
115 int i, err;
116
117 buckets = flex_array_alloc(sizeof(struct hlist_head),
118 n_buckets, GFP_KERNEL);
119 if (!buckets)
120 return NULL;
121
122 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
123 if (err) {
124 flex_array_free(buckets);
125 return NULL;
126 }
127
128 for (i = 0; i < n_buckets; i++)
129 INIT_HLIST_HEAD((struct hlist_head *)
130 flex_array_get(buckets, i));
131
132 return buckets;
133}
134
135static void flow_free(struct sw_flow *flow)
136{
137 int cpu;
138
139 if (ovs_identifier_is_key(&flow->id))
140 kfree(flow->id.unmasked_key);
141 if (flow->sf_acts)
142 ovs_nla_free_flow_actions((struct sw_flow_actions __force *)flow->sf_acts);
143 /* We open code this to make sure cpu 0 is always considered */
144 for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, cpu_possible_mask))
145 if (flow->stats[cpu])
146 kmem_cache_free(flow_stats_cache,
147 (struct flow_stats __force *)flow->stats[cpu]);
148 kmem_cache_free(flow_cache, flow);
149}
150
151static void rcu_free_flow_callback(struct rcu_head *rcu)
152{
153 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
154
155 flow_free(flow);
156}
157
158void ovs_flow_free(struct sw_flow *flow, bool deferred)
159{
160 if (!flow)
161 return;
162
163 if (deferred)
164 call_rcu(&flow->rcu, rcu_free_flow_callback);
165 else
166 flow_free(flow);
167}
168
169static void free_buckets(struct flex_array *buckets)
170{
171 flex_array_free(buckets);
172}
173
174
175static void __table_instance_destroy(struct table_instance *ti)
176{
177 free_buckets(ti->buckets);
178 kfree(ti);
179}
180
181static struct table_instance *table_instance_alloc(int new_size)
182{
183 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
184
185 if (!ti)
186 return NULL;
187
188 ti->buckets = alloc_buckets(new_size);
189
190 if (!ti->buckets) {
191 kfree(ti);
192 return NULL;
193 }
194 ti->n_buckets = new_size;
195 ti->node_ver = 0;
196 ti->keep_flows = false;
197 get_random_bytes(&ti->hash_seed, sizeof(u32));
198
199 return ti;
200}
201
202int ovs_flow_tbl_init(struct flow_table *table)
203{
204 struct table_instance *ti, *ufid_ti;
205
206 ti = table_instance_alloc(TBL_MIN_BUCKETS);
207
208 if (!ti)
209 return -ENOMEM;
210
211 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
212 if (!ufid_ti)
213 goto free_ti;
214
215 rcu_assign_pointer(table->ti, ti);
216 rcu_assign_pointer(table->ufid_ti, ufid_ti);
217 INIT_LIST_HEAD(&table->mask_list);
218 table->last_rehash = jiffies;
219 table->count = 0;
220 table->ufid_count = 0;
221 return 0;
222
223free_ti:
224 __table_instance_destroy(ti);
225 return -ENOMEM;
226}
227
228static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
229{
230 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
231
232 __table_instance_destroy(ti);
233}
234
235static void table_instance_destroy(struct table_instance *ti,
236 struct table_instance *ufid_ti,
237 bool deferred)
238{
239 int i;
240
241 if (!ti)
242 return;
243
244 BUG_ON(!ufid_ti);
245 if (ti->keep_flows)
246 goto skip_flows;
247
248 for (i = 0; i < ti->n_buckets; i++) {
249 struct sw_flow *flow;
250 struct hlist_head *head = flex_array_get(ti->buckets, i);
251 struct hlist_node *n;
252 int ver = ti->node_ver;
253 int ufid_ver = ufid_ti->node_ver;
254
255 hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) {
256 hlist_del_rcu(&flow->flow_table.node[ver]);
257 if (ovs_identifier_is_ufid(&flow->id))
258 hlist_del_rcu(&flow->ufid_table.node[ufid_ver]);
259 ovs_flow_free(flow, deferred);
260 }
261 }
262
263skip_flows:
264 if (deferred) {
265 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
266 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
267 } else {
268 __table_instance_destroy(ti);
269 __table_instance_destroy(ufid_ti);
270 }
271}
272
273/* No need for locking this function is called from RCU callback or
274 * error path.
275 */
276void ovs_flow_tbl_destroy(struct flow_table *table)
277{
278 struct table_instance *ti = rcu_dereference_raw(table->ti);
279 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
280
281 table_instance_destroy(ti, ufid_ti, false);
282}
283
284struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
285 u32 *bucket, u32 *last)
286{
287 struct sw_flow *flow;
288 struct hlist_head *head;
289 int ver;
290 int i;
291
292 ver = ti->node_ver;
293 while (*bucket < ti->n_buckets) {
294 i = 0;
295 head = flex_array_get(ti->buckets, *bucket);
296 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
297 if (i < *last) {
298 i++;
299 continue;
300 }
301 *last = i + 1;
302 return flow;
303 }
304 (*bucket)++;
305 *last = 0;
306 }
307
308 return NULL;
309}
310
311static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
312{
313 hash = jhash_1word(hash, ti->hash_seed);
314 return flex_array_get(ti->buckets,
315 (hash & (ti->n_buckets - 1)));
316}
317
318static void table_instance_insert(struct table_instance *ti,
319 struct sw_flow *flow)
320{
321 struct hlist_head *head;
322
323 head = find_bucket(ti, flow->flow_table.hash);
324 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head);
325}
326
327static void ufid_table_instance_insert(struct table_instance *ti,
328 struct sw_flow *flow)
329{
330 struct hlist_head *head;
331
332 head = find_bucket(ti, flow->ufid_table.hash);
333 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head);
334}
335
336static void flow_table_copy_flows(struct table_instance *old,
337 struct table_instance *new, bool ufid)
338{
339 int old_ver;
340 int i;
341
342 old_ver = old->node_ver;
343 new->node_ver = !old_ver;
344
345 /* Insert in new table. */
346 for (i = 0; i < old->n_buckets; i++) {
347 struct sw_flow *flow;
348 struct hlist_head *head;
349
350 head = flex_array_get(old->buckets, i);
351
352 if (ufid)
353 hlist_for_each_entry(flow, head,
354 ufid_table.node[old_ver])
355 ufid_table_instance_insert(new, flow);
356 else
357 hlist_for_each_entry(flow, head,
358 flow_table.node[old_ver])
359 table_instance_insert(new, flow);
360 }
361
362 old->keep_flows = true;
363}
364
365static struct table_instance *table_instance_rehash(struct table_instance *ti,
366 int n_buckets, bool ufid)
367{
368 struct table_instance *new_ti;
369
370 new_ti = table_instance_alloc(n_buckets);
371 if (!new_ti)
372 return NULL;
373
374 flow_table_copy_flows(ti, new_ti, ufid);
375
376 return new_ti;
377}
378
379int ovs_flow_tbl_flush(struct flow_table *flow_table)
380{
381 struct table_instance *old_ti, *new_ti;
382 struct table_instance *old_ufid_ti, *new_ufid_ti;
383
384 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
385 if (!new_ti)
386 return -ENOMEM;
387 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
388 if (!new_ufid_ti)
389 goto err_free_ti;
390
391 old_ti = ovsl_dereference(flow_table->ti);
392 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti);
393
394 rcu_assign_pointer(flow_table->ti, new_ti);
395 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
396 flow_table->last_rehash = jiffies;
397 flow_table->count = 0;
398 flow_table->ufid_count = 0;
399
400 table_instance_destroy(old_ti, old_ufid_ti, true);
401 return 0;
402
403err_free_ti:
404 __table_instance_destroy(new_ti);
405 return -ENOMEM;
406}
407
408static u32 flow_hash(const struct sw_flow_key *key,
409 const struct sw_flow_key_range *range)
410{
411 int key_start = range->start;
412 int key_end = range->end;
413 const u32 *hash_key = (const u32 *)((const u8 *)key + key_start);
414 int hash_u32s = (key_end - key_start) >> 2;
415
416 /* Make sure number of hash bytes are multiple of u32. */
417 BUILD_BUG_ON(sizeof(long) % sizeof(u32));
418
419 return jhash2(hash_key, hash_u32s, 0);
420}
421
422static int flow_key_start(const struct sw_flow_key *key)
423{
424 if (key->tun_proto)
425 return 0;
426 else
427 return rounddown(offsetof(struct sw_flow_key, phy),
428 sizeof(long));
429}
430
431static bool cmp_key(const struct sw_flow_key *key1,
432 const struct sw_flow_key *key2,
433 int key_start, int key_end)
434{
435 const long *cp1 = (const long *)((const u8 *)key1 + key_start);
436 const long *cp2 = (const long *)((const u8 *)key2 + key_start);
437 long diffs = 0;
438 int i;
439
440 for (i = key_start; i < key_end; i += sizeof(long))
441 diffs |= *cp1++ ^ *cp2++;
442
443 return diffs == 0;
444}
445
446static bool flow_cmp_masked_key(const struct sw_flow *flow,
447 const struct sw_flow_key *key,
448 const struct sw_flow_key_range *range)
449{
450 return cmp_key(&flow->key, key, range->start, range->end);
451}
452
453static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
454 const struct sw_flow_match *match)
455{
456 struct sw_flow_key *key = match->key;
457 int key_start = flow_key_start(key);
458 int key_end = match->range.end;
459
460 BUG_ON(ovs_identifier_is_ufid(&flow->id));
461 return cmp_key(flow->id.unmasked_key, key, key_start, key_end);
462}
463
464static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
465 const struct sw_flow_key *unmasked,
466 const struct sw_flow_mask *mask)
467{
468 struct sw_flow *flow;
469 struct hlist_head *head;
470 u32 hash;
471 struct sw_flow_key masked_key;
472
473 ovs_flow_mask_key(&masked_key, unmasked, false, mask);
474 hash = flow_hash(&masked_key, &mask->range);
475 head = find_bucket(ti, hash);
476 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) {
477 if (flow->mask == mask && flow->flow_table.hash == hash &&
478 flow_cmp_masked_key(flow, &masked_key, &mask->range))
479 return flow;
480 }
481 return NULL;
482}
483
484struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
485 const struct sw_flow_key *key,
486 u32 *n_mask_hit)
487{
488 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
489 struct sw_flow_mask *mask;
490 struct sw_flow *flow;
491
492 *n_mask_hit = 0;
493 list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
494 (*n_mask_hit)++;
495 flow = masked_flow_lookup(ti, key, mask);
496 if (flow) /* Found */
497 return flow;
498 }
499 return NULL;
500}
501
502struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
503 const struct sw_flow_key *key)
504{
505 u32 __always_unused n_mask_hit;
506
507 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
508}
509
510struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
511 const struct sw_flow_match *match)
512{
513 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
514 struct sw_flow_mask *mask;
515 struct sw_flow *flow;
516
517 /* Always called under ovs-mutex. */
518 list_for_each_entry(mask, &tbl->mask_list, list) {
519 flow = masked_flow_lookup(ti, match->key, mask);
520 if (flow && ovs_identifier_is_key(&flow->id) &&
521 ovs_flow_cmp_unmasked_key(flow, match))
522 return flow;
523 }
524 return NULL;
525}
526
527static u32 ufid_hash(const struct sw_flow_id *sfid)
528{
529 return jhash(sfid->ufid, sfid->ufid_len, 0);
530}
531
532static bool ovs_flow_cmp_ufid(const struct sw_flow *flow,
533 const struct sw_flow_id *sfid)
534{
535 if (flow->id.ufid_len != sfid->ufid_len)
536 return false;
537
538 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
539}
540
541bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match)
542{
543 if (ovs_identifier_is_ufid(&flow->id))
544 return flow_cmp_masked_key(flow, match->key, &match->range);
545
546 return ovs_flow_cmp_unmasked_key(flow, match);
547}
548
549struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
550 const struct sw_flow_id *ufid)
551{
552 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti);
553 struct sw_flow *flow;
554 struct hlist_head *head;
555 u32 hash;
556
557 hash = ufid_hash(ufid);
558 head = find_bucket(ti, hash);
559 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) {
560 if (flow->ufid_table.hash == hash &&
561 ovs_flow_cmp_ufid(flow, ufid))
562 return flow;
563 }
564 return NULL;
565}
566
567int ovs_flow_tbl_num_masks(const struct flow_table *table)
568{
569 struct sw_flow_mask *mask;
570 int num = 0;
571
572 list_for_each_entry(mask, &table->mask_list, list)
573 num++;
574
575 return num;
576}
577
578static struct table_instance *table_instance_expand(struct table_instance *ti,
579 bool ufid)
580{
581 return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
582}
583
584/* Remove 'mask' from the mask list, if it is not needed any more. */
585static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
586{
587 if (mask) {
588 /* ovs-lock is required to protect mask-refcount and
589 * mask list.
590 */
591 ASSERT_OVSL();
592 BUG_ON(!mask->ref_count);
593 mask->ref_count--;
594
595 if (!mask->ref_count) {
596 list_del_rcu(&mask->list);
597 kfree_rcu(mask, rcu);
598 }
599 }
600}
601
602/* Must be called with OVS mutex held. */
603void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
604{
605 struct table_instance *ti = ovsl_dereference(table->ti);
606 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
607
608 BUG_ON(table->count == 0);
609 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
610 table->count--;
611 if (ovs_identifier_is_ufid(&flow->id)) {
612 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
613 table->ufid_count--;
614 }
615
616 /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be
617 * accessible as long as the RCU read lock is held.
618 */
619 flow_mask_remove(table, flow->mask);
620}
621
622static struct sw_flow_mask *mask_alloc(void)
623{
624 struct sw_flow_mask *mask;
625
626 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
627 if (mask)
628 mask->ref_count = 1;
629
630 return mask;
631}
632
633static bool mask_equal(const struct sw_flow_mask *a,
634 const struct sw_flow_mask *b)
635{
636 const u8 *a_ = (const u8 *)&a->key + a->range.start;
637 const u8 *b_ = (const u8 *)&b->key + b->range.start;
638
639 return (a->range.end == b->range.end)
640 && (a->range.start == b->range.start)
641 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
642}
643
644static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
645 const struct sw_flow_mask *mask)
646{
647 struct list_head *ml;
648
649 list_for_each(ml, &tbl->mask_list) {
650 struct sw_flow_mask *m;
651 m = container_of(ml, struct sw_flow_mask, list);
652 if (mask_equal(mask, m))
653 return m;
654 }
655
656 return NULL;
657}
658
659/* Add 'mask' into the mask list, if it is not already there. */
660static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
661 const struct sw_flow_mask *new)
662{
663 struct sw_flow_mask *mask;
664 mask = flow_mask_find(tbl, new);
665 if (!mask) {
666 /* Allocate a new mask if none exsits. */
667 mask = mask_alloc();
668 if (!mask)
669 return -ENOMEM;
670 mask->key = new->key;
671 mask->range = new->range;
672 list_add_rcu(&mask->list, &tbl->mask_list);
673 } else {
674 BUG_ON(!mask->ref_count);
675 mask->ref_count++;
676 }
677
678 flow->mask = mask;
679 return 0;
680}
681
682/* Must be called with OVS mutex held. */
683static void flow_key_insert(struct flow_table *table, struct sw_flow *flow)
684{
685 struct table_instance *new_ti = NULL;
686 struct table_instance *ti;
687
688 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range);
689 ti = ovsl_dereference(table->ti);
690 table_instance_insert(ti, flow);
691 table->count++;
692
693 /* Expand table, if necessary, to make room. */
694 if (table->count > ti->n_buckets)
695 new_ti = table_instance_expand(ti, false);
696 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
697 new_ti = table_instance_rehash(ti, ti->n_buckets, false);
698
699 if (new_ti) {
700 rcu_assign_pointer(table->ti, new_ti);
701 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
702 table->last_rehash = jiffies;
703 }
704}
705
706/* Must be called with OVS mutex held. */
707static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow)
708{
709 struct table_instance *ti;
710
711 flow->ufid_table.hash = ufid_hash(&flow->id);
712 ti = ovsl_dereference(table->ufid_ti);
713 ufid_table_instance_insert(ti, flow);
714 table->ufid_count++;
715
716 /* Expand table, if necessary, to make room. */
717 if (table->ufid_count > ti->n_buckets) {
718 struct table_instance *new_ti;
719
720 new_ti = table_instance_expand(ti, true);
721 if (new_ti) {
722 rcu_assign_pointer(table->ufid_ti, new_ti);
723 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
724 }
725 }
726}
727
728/* Must be called with OVS mutex held. */
729int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
730 const struct sw_flow_mask *mask)
731{
732 int err;
733
734 err = flow_mask_insert(table, flow, mask);
735 if (err)
736 return err;
737 flow_key_insert(table, flow);
738 if (ovs_identifier_is_ufid(&flow->id))
739 flow_ufid_insert(table, flow);
740
741 return 0;
742}
743
744/* Initializes the flow module.
745 * Returns zero if successful or a negative error code. */
746int ovs_flow_init(void)
747{
748 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
749 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
750
751 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
752 + (nr_cpu_ids
753 * sizeof(struct flow_stats *)),
754 0, 0, NULL);
755 if (flow_cache == NULL)
756 return -ENOMEM;
757
758 flow_stats_cache
759 = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats),
760 0, SLAB_HWCACHE_ALIGN, NULL);
761 if (flow_stats_cache == NULL) {
762 kmem_cache_destroy(flow_cache);
763 flow_cache = NULL;
764 return -ENOMEM;
765 }
766
767 return 0;
768}
769
770/* Uninitializes the flow module. */
771void ovs_flow_exit(void)
772{
773 kmem_cache_destroy(flow_stats_cache);
774 kmem_cache_destroy(flow_cache);
775}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2007-2014 Nicira, Inc.
4 */
5
6#include "flow.h"
7#include "datapath.h"
8#include "flow_netlink.h"
9#include <linux/uaccess.h>
10#include <linux/netdevice.h>
11#include <linux/etherdevice.h>
12#include <linux/if_ether.h>
13#include <linux/if_vlan.h>
14#include <net/llc_pdu.h>
15#include <linux/kernel.h>
16#include <linux/jhash.h>
17#include <linux/jiffies.h>
18#include <linux/llc.h>
19#include <linux/module.h>
20#include <linux/in.h>
21#include <linux/rcupdate.h>
22#include <linux/cpumask.h>
23#include <linux/if_arp.h>
24#include <linux/ip.h>
25#include <linux/ipv6.h>
26#include <linux/sctp.h>
27#include <linux/tcp.h>
28#include <linux/udp.h>
29#include <linux/icmp.h>
30#include <linux/icmpv6.h>
31#include <linux/rculist.h>
32#include <linux/sort.h>
33#include <net/ip.h>
34#include <net/ipv6.h>
35#include <net/ndisc.h>
36
37#define TBL_MIN_BUCKETS 1024
38#define MASK_ARRAY_SIZE_MIN 16
39#define REHASH_INTERVAL (10 * 60 * HZ)
40
41#define MC_DEFAULT_HASH_ENTRIES 256
42#define MC_HASH_SHIFT 8
43#define MC_HASH_SEGS ((sizeof(uint32_t) * 8) / MC_HASH_SHIFT)
44
45static struct kmem_cache *flow_cache;
46struct kmem_cache *flow_stats_cache __read_mostly;
47
48static u16 range_n_bytes(const struct sw_flow_key_range *range)
49{
50 return range->end - range->start;
51}
52
53void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
54 bool full, const struct sw_flow_mask *mask)
55{
56 int start = full ? 0 : mask->range.start;
57 int len = full ? sizeof *dst : range_n_bytes(&mask->range);
58 const long *m = (const long *)((const u8 *)&mask->key + start);
59 const long *s = (const long *)((const u8 *)src + start);
60 long *d = (long *)((u8 *)dst + start);
61 int i;
62
63 /* If 'full' is true then all of 'dst' is fully initialized. Otherwise,
64 * if 'full' is false the memory outside of the 'mask->range' is left
65 * uninitialized. This can be used as an optimization when further
66 * operations on 'dst' only use contents within 'mask->range'.
67 */
68 for (i = 0; i < len; i += sizeof(long))
69 *d++ = *s++ & *m++;
70}
71
72struct sw_flow *ovs_flow_alloc(void)
73{
74 struct sw_flow *flow;
75 struct sw_flow_stats *stats;
76
77 flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL);
78 if (!flow)
79 return ERR_PTR(-ENOMEM);
80
81 flow->stats_last_writer = -1;
82
83 /* Initialize the default stat node. */
84 stats = kmem_cache_alloc_node(flow_stats_cache,
85 GFP_KERNEL | __GFP_ZERO,
86 node_online(0) ? 0 : NUMA_NO_NODE);
87 if (!stats)
88 goto err;
89
90 spin_lock_init(&stats->lock);
91
92 RCU_INIT_POINTER(flow->stats[0], stats);
93
94 cpumask_set_cpu(0, &flow->cpu_used_mask);
95
96 return flow;
97err:
98 kmem_cache_free(flow_cache, flow);
99 return ERR_PTR(-ENOMEM);
100}
101
102int ovs_flow_tbl_count(const struct flow_table *table)
103{
104 return table->count;
105}
106
107static void flow_free(struct sw_flow *flow)
108{
109 int cpu;
110
111 if (ovs_identifier_is_key(&flow->id))
112 kfree(flow->id.unmasked_key);
113 if (flow->sf_acts)
114 ovs_nla_free_flow_actions((struct sw_flow_actions __force *)
115 flow->sf_acts);
116 /* We open code this to make sure cpu 0 is always considered */
117 for (cpu = 0; cpu < nr_cpu_ids;
118 cpu = cpumask_next(cpu, &flow->cpu_used_mask)) {
119 if (flow->stats[cpu])
120 kmem_cache_free(flow_stats_cache,
121 (struct sw_flow_stats __force *)flow->stats[cpu]);
122 }
123
124 kmem_cache_free(flow_cache, flow);
125}
126
127static void rcu_free_flow_callback(struct rcu_head *rcu)
128{
129 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
130
131 flow_free(flow);
132}
133
134void ovs_flow_free(struct sw_flow *flow, bool deferred)
135{
136 if (!flow)
137 return;
138
139 if (deferred)
140 call_rcu(&flow->rcu, rcu_free_flow_callback);
141 else
142 flow_free(flow);
143}
144
145static void __table_instance_destroy(struct table_instance *ti)
146{
147 kvfree(ti->buckets);
148 kfree(ti);
149}
150
151static struct table_instance *table_instance_alloc(int new_size)
152{
153 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
154 int i;
155
156 if (!ti)
157 return NULL;
158
159 ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
160 GFP_KERNEL);
161 if (!ti->buckets) {
162 kfree(ti);
163 return NULL;
164 }
165
166 for (i = 0; i < new_size; i++)
167 INIT_HLIST_HEAD(&ti->buckets[i]);
168
169 ti->n_buckets = new_size;
170 ti->node_ver = 0;
171 get_random_bytes(&ti->hash_seed, sizeof(u32));
172
173 return ti;
174}
175
176static void __mask_array_destroy(struct mask_array *ma)
177{
178 free_percpu(ma->masks_usage_stats);
179 kfree(ma);
180}
181
182static void mask_array_rcu_cb(struct rcu_head *rcu)
183{
184 struct mask_array *ma = container_of(rcu, struct mask_array, rcu);
185
186 __mask_array_destroy(ma);
187}
188
189static void tbl_mask_array_reset_counters(struct mask_array *ma)
190{
191 int i, cpu;
192
193 /* As the per CPU counters are not atomic we can not go ahead and
194 * reset them from another CPU. To be able to still have an approximate
195 * zero based counter we store the value at reset, and subtract it
196 * later when processing.
197 */
198 for (i = 0; i < ma->max; i++) {
199 ma->masks_usage_zero_cntr[i] = 0;
200
201 for_each_possible_cpu(cpu) {
202 struct mask_array_stats *stats;
203 unsigned int start;
204 u64 counter;
205
206 stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
207 do {
208 start = u64_stats_fetch_begin(&stats->syncp);
209 counter = stats->usage_cntrs[i];
210 } while (u64_stats_fetch_retry(&stats->syncp, start));
211
212 ma->masks_usage_zero_cntr[i] += counter;
213 }
214 }
215}
216
217static struct mask_array *tbl_mask_array_alloc(int size)
218{
219 struct mask_array *new;
220
221 size = max(MASK_ARRAY_SIZE_MIN, size);
222 new = kzalloc(sizeof(struct mask_array) +
223 sizeof(struct sw_flow_mask *) * size +
224 sizeof(u64) * size, GFP_KERNEL);
225 if (!new)
226 return NULL;
227
228 new->masks_usage_zero_cntr = (u64 *)((u8 *)new +
229 sizeof(struct mask_array) +
230 sizeof(struct sw_flow_mask *) *
231 size);
232
233 new->masks_usage_stats = __alloc_percpu(sizeof(struct mask_array_stats) +
234 sizeof(u64) * size,
235 __alignof__(u64));
236 if (!new->masks_usage_stats) {
237 kfree(new);
238 return NULL;
239 }
240
241 new->count = 0;
242 new->max = size;
243
244 return new;
245}
246
247static int tbl_mask_array_realloc(struct flow_table *tbl, int size)
248{
249 struct mask_array *old;
250 struct mask_array *new;
251
252 new = tbl_mask_array_alloc(size);
253 if (!new)
254 return -ENOMEM;
255
256 old = ovsl_dereference(tbl->mask_array);
257 if (old) {
258 int i;
259
260 for (i = 0; i < old->max; i++) {
261 if (ovsl_dereference(old->masks[i]))
262 new->masks[new->count++] = old->masks[i];
263 }
264 call_rcu(&old->rcu, mask_array_rcu_cb);
265 }
266
267 rcu_assign_pointer(tbl->mask_array, new);
268
269 return 0;
270}
271
272static int tbl_mask_array_add_mask(struct flow_table *tbl,
273 struct sw_flow_mask *new)
274{
275 struct mask_array *ma = ovsl_dereference(tbl->mask_array);
276 int err, ma_count = READ_ONCE(ma->count);
277
278 if (ma_count >= ma->max) {
279 err = tbl_mask_array_realloc(tbl, ma->max +
280 MASK_ARRAY_SIZE_MIN);
281 if (err)
282 return err;
283
284 ma = ovsl_dereference(tbl->mask_array);
285 } else {
286 /* On every add or delete we need to reset the counters so
287 * every new mask gets a fair chance of being prioritized.
288 */
289 tbl_mask_array_reset_counters(ma);
290 }
291
292 BUG_ON(ovsl_dereference(ma->masks[ma_count]));
293
294 rcu_assign_pointer(ma->masks[ma_count], new);
295 WRITE_ONCE(ma->count, ma_count + 1);
296
297 return 0;
298}
299
300static void tbl_mask_array_del_mask(struct flow_table *tbl,
301 struct sw_flow_mask *mask)
302{
303 struct mask_array *ma = ovsl_dereference(tbl->mask_array);
304 int i, ma_count = READ_ONCE(ma->count);
305
306 /* Remove the deleted mask pointers from the array */
307 for (i = 0; i < ma_count; i++) {
308 if (mask == ovsl_dereference(ma->masks[i]))
309 goto found;
310 }
311
312 BUG();
313 return;
314
315found:
316 WRITE_ONCE(ma->count, ma_count - 1);
317
318 rcu_assign_pointer(ma->masks[i], ma->masks[ma_count - 1]);
319 RCU_INIT_POINTER(ma->masks[ma_count - 1], NULL);
320
321 kfree_rcu(mask, rcu);
322
323 /* Shrink the mask array if necessary. */
324 if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) &&
325 ma_count <= (ma->max / 3))
326 tbl_mask_array_realloc(tbl, ma->max / 2);
327 else
328 tbl_mask_array_reset_counters(ma);
329
330}
331
332/* Remove 'mask' from the mask list, if it is not needed any more. */
333static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
334{
335 if (mask) {
336 /* ovs-lock is required to protect mask-refcount and
337 * mask list.
338 */
339 ASSERT_OVSL();
340 BUG_ON(!mask->ref_count);
341 mask->ref_count--;
342
343 if (!mask->ref_count)
344 tbl_mask_array_del_mask(tbl, mask);
345 }
346}
347
348static void __mask_cache_destroy(struct mask_cache *mc)
349{
350 free_percpu(mc->mask_cache);
351 kfree(mc);
352}
353
354static void mask_cache_rcu_cb(struct rcu_head *rcu)
355{
356 struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu);
357
358 __mask_cache_destroy(mc);
359}
360
361static struct mask_cache *tbl_mask_cache_alloc(u32 size)
362{
363 struct mask_cache_entry __percpu *cache = NULL;
364 struct mask_cache *new;
365
366 /* Only allow size to be 0, or a power of 2, and does not exceed
367 * percpu allocation size.
368 */
369 if ((!is_power_of_2(size) && size != 0) ||
370 (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
371 return NULL;
372
373 new = kzalloc(sizeof(*new), GFP_KERNEL);
374 if (!new)
375 return NULL;
376
377 new->cache_size = size;
378 if (new->cache_size > 0) {
379 cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry),
380 new->cache_size),
381 __alignof__(struct mask_cache_entry));
382 if (!cache) {
383 kfree(new);
384 return NULL;
385 }
386 }
387
388 new->mask_cache = cache;
389 return new;
390}
391int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
392{
393 struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
394 struct mask_cache *new;
395
396 if (size == mc->cache_size)
397 return 0;
398
399 if ((!is_power_of_2(size) && size != 0) ||
400 (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
401 return -EINVAL;
402
403 new = tbl_mask_cache_alloc(size);
404 if (!new)
405 return -ENOMEM;
406
407 rcu_assign_pointer(table->mask_cache, new);
408 call_rcu(&mc->rcu, mask_cache_rcu_cb);
409
410 return 0;
411}
412
413int ovs_flow_tbl_init(struct flow_table *table)
414{
415 struct table_instance *ti, *ufid_ti;
416 struct mask_cache *mc;
417 struct mask_array *ma;
418
419 mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES);
420 if (!mc)
421 return -ENOMEM;
422
423 ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
424 if (!ma)
425 goto free_mask_cache;
426
427 ti = table_instance_alloc(TBL_MIN_BUCKETS);
428 if (!ti)
429 goto free_mask_array;
430
431 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
432 if (!ufid_ti)
433 goto free_ti;
434
435 rcu_assign_pointer(table->ti, ti);
436 rcu_assign_pointer(table->ufid_ti, ufid_ti);
437 rcu_assign_pointer(table->mask_array, ma);
438 rcu_assign_pointer(table->mask_cache, mc);
439 table->last_rehash = jiffies;
440 table->count = 0;
441 table->ufid_count = 0;
442 return 0;
443
444free_ti:
445 __table_instance_destroy(ti);
446free_mask_array:
447 __mask_array_destroy(ma);
448free_mask_cache:
449 __mask_cache_destroy(mc);
450 return -ENOMEM;
451}
452
453static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
454{
455 struct table_instance *ti;
456
457 ti = container_of(rcu, struct table_instance, rcu);
458 __table_instance_destroy(ti);
459}
460
461static void table_instance_flow_free(struct flow_table *table,
462 struct table_instance *ti,
463 struct table_instance *ufid_ti,
464 struct sw_flow *flow)
465{
466 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
467 table->count--;
468
469 if (ovs_identifier_is_ufid(&flow->id)) {
470 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
471 table->ufid_count--;
472 }
473
474 flow_mask_remove(table, flow->mask);
475}
476
477/* Must be called with OVS mutex held. */
478void table_instance_flow_flush(struct flow_table *table,
479 struct table_instance *ti,
480 struct table_instance *ufid_ti)
481{
482 int i;
483
484 for (i = 0; i < ti->n_buckets; i++) {
485 struct hlist_head *head = &ti->buckets[i];
486 struct hlist_node *n;
487 struct sw_flow *flow;
488
489 hlist_for_each_entry_safe(flow, n, head,
490 flow_table.node[ti->node_ver]) {
491
492 table_instance_flow_free(table, ti, ufid_ti,
493 flow);
494 ovs_flow_free(flow, true);
495 }
496 }
497
498 if (WARN_ON(table->count != 0 ||
499 table->ufid_count != 0)) {
500 table->count = 0;
501 table->ufid_count = 0;
502 }
503}
504
505static void table_instance_destroy(struct table_instance *ti,
506 struct table_instance *ufid_ti)
507{
508 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
509 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
510}
511
512/* No need for locking this function is called from RCU callback or
513 * error path.
514 */
515void ovs_flow_tbl_destroy(struct flow_table *table)
516{
517 struct table_instance *ti = rcu_dereference_raw(table->ti);
518 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
519 struct mask_cache *mc = rcu_dereference_raw(table->mask_cache);
520 struct mask_array *ma = rcu_dereference_raw(table->mask_array);
521
522 call_rcu(&mc->rcu, mask_cache_rcu_cb);
523 call_rcu(&ma->rcu, mask_array_rcu_cb);
524 table_instance_destroy(ti, ufid_ti);
525}
526
527struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
528 u32 *bucket, u32 *last)
529{
530 struct sw_flow *flow;
531 struct hlist_head *head;
532 int ver;
533 int i;
534
535 ver = ti->node_ver;
536 while (*bucket < ti->n_buckets) {
537 i = 0;
538 head = &ti->buckets[*bucket];
539 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
540 if (i < *last) {
541 i++;
542 continue;
543 }
544 *last = i + 1;
545 return flow;
546 }
547 (*bucket)++;
548 *last = 0;
549 }
550
551 return NULL;
552}
553
554static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
555{
556 hash = jhash_1word(hash, ti->hash_seed);
557 return &ti->buckets[hash & (ti->n_buckets - 1)];
558}
559
560static void table_instance_insert(struct table_instance *ti,
561 struct sw_flow *flow)
562{
563 struct hlist_head *head;
564
565 head = find_bucket(ti, flow->flow_table.hash);
566 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head);
567}
568
569static void ufid_table_instance_insert(struct table_instance *ti,
570 struct sw_flow *flow)
571{
572 struct hlist_head *head;
573
574 head = find_bucket(ti, flow->ufid_table.hash);
575 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head);
576}
577
578static void flow_table_copy_flows(struct table_instance *old,
579 struct table_instance *new, bool ufid)
580{
581 int old_ver;
582 int i;
583
584 old_ver = old->node_ver;
585 new->node_ver = !old_ver;
586
587 /* Insert in new table. */
588 for (i = 0; i < old->n_buckets; i++) {
589 struct sw_flow *flow;
590 struct hlist_head *head = &old->buckets[i];
591
592 if (ufid)
593 hlist_for_each_entry_rcu(flow, head,
594 ufid_table.node[old_ver],
595 lockdep_ovsl_is_held())
596 ufid_table_instance_insert(new, flow);
597 else
598 hlist_for_each_entry_rcu(flow, head,
599 flow_table.node[old_ver],
600 lockdep_ovsl_is_held())
601 table_instance_insert(new, flow);
602 }
603}
604
605static struct table_instance *table_instance_rehash(struct table_instance *ti,
606 int n_buckets, bool ufid)
607{
608 struct table_instance *new_ti;
609
610 new_ti = table_instance_alloc(n_buckets);
611 if (!new_ti)
612 return NULL;
613
614 flow_table_copy_flows(ti, new_ti, ufid);
615
616 return new_ti;
617}
618
619int ovs_flow_tbl_flush(struct flow_table *flow_table)
620{
621 struct table_instance *old_ti, *new_ti;
622 struct table_instance *old_ufid_ti, *new_ufid_ti;
623
624 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
625 if (!new_ti)
626 return -ENOMEM;
627 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
628 if (!new_ufid_ti)
629 goto err_free_ti;
630
631 old_ti = ovsl_dereference(flow_table->ti);
632 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti);
633
634 rcu_assign_pointer(flow_table->ti, new_ti);
635 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
636 flow_table->last_rehash = jiffies;
637
638 table_instance_flow_flush(flow_table, old_ti, old_ufid_ti);
639 table_instance_destroy(old_ti, old_ufid_ti);
640 return 0;
641
642err_free_ti:
643 __table_instance_destroy(new_ti);
644 return -ENOMEM;
645}
646
647static u32 flow_hash(const struct sw_flow_key *key,
648 const struct sw_flow_key_range *range)
649{
650 const u32 *hash_key = (const u32 *)((const u8 *)key + range->start);
651
652 /* Make sure number of hash bytes are multiple of u32. */
653 int hash_u32s = range_n_bytes(range) >> 2;
654
655 return jhash2(hash_key, hash_u32s, 0);
656}
657
658static int flow_key_start(const struct sw_flow_key *key)
659{
660 if (key->tun_proto)
661 return 0;
662 else
663 return rounddown(offsetof(struct sw_flow_key, phy),
664 sizeof(long));
665}
666
667static bool cmp_key(const struct sw_flow_key *key1,
668 const struct sw_flow_key *key2,
669 int key_start, int key_end)
670{
671 const long *cp1 = (const long *)((const u8 *)key1 + key_start);
672 const long *cp2 = (const long *)((const u8 *)key2 + key_start);
673 int i;
674
675 for (i = key_start; i < key_end; i += sizeof(long))
676 if (*cp1++ ^ *cp2++)
677 return false;
678
679 return true;
680}
681
682static bool flow_cmp_masked_key(const struct sw_flow *flow,
683 const struct sw_flow_key *key,
684 const struct sw_flow_key_range *range)
685{
686 return cmp_key(&flow->key, key, range->start, range->end);
687}
688
689static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
690 const struct sw_flow_match *match)
691{
692 struct sw_flow_key *key = match->key;
693 int key_start = flow_key_start(key);
694 int key_end = match->range.end;
695
696 BUG_ON(ovs_identifier_is_ufid(&flow->id));
697 return cmp_key(flow->id.unmasked_key, key, key_start, key_end);
698}
699
700static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
701 const struct sw_flow_key *unmasked,
702 const struct sw_flow_mask *mask,
703 u32 *n_mask_hit)
704{
705 struct sw_flow *flow;
706 struct hlist_head *head;
707 u32 hash;
708 struct sw_flow_key masked_key;
709
710 ovs_flow_mask_key(&masked_key, unmasked, false, mask);
711 hash = flow_hash(&masked_key, &mask->range);
712 head = find_bucket(ti, hash);
713 (*n_mask_hit)++;
714
715 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver],
716 lockdep_ovsl_is_held()) {
717 if (flow->mask == mask && flow->flow_table.hash == hash &&
718 flow_cmp_masked_key(flow, &masked_key, &mask->range))
719 return flow;
720 }
721 return NULL;
722}
723
724/* Flow lookup does full lookup on flow table. It starts with
725 * mask from index passed in *index.
726 * This function MUST be called with BH disabled due to the use
727 * of CPU specific variables.
728 */
729static struct sw_flow *flow_lookup(struct flow_table *tbl,
730 struct table_instance *ti,
731 struct mask_array *ma,
732 const struct sw_flow_key *key,
733 u32 *n_mask_hit,
734 u32 *n_cache_hit,
735 u32 *index)
736{
737 struct mask_array_stats *stats = this_cpu_ptr(ma->masks_usage_stats);
738 struct sw_flow *flow;
739 struct sw_flow_mask *mask;
740 int i;
741
742 if (likely(*index < ma->max)) {
743 mask = rcu_dereference_ovsl(ma->masks[*index]);
744 if (mask) {
745 flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
746 if (flow) {
747 u64_stats_update_begin(&stats->syncp);
748 stats->usage_cntrs[*index]++;
749 u64_stats_update_end(&stats->syncp);
750 (*n_cache_hit)++;
751 return flow;
752 }
753 }
754 }
755
756 for (i = 0; i < ma->max; i++) {
757
758 if (i == *index)
759 continue;
760
761 mask = rcu_dereference_ovsl(ma->masks[i]);
762 if (unlikely(!mask))
763 break;
764
765 flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
766 if (flow) { /* Found */
767 *index = i;
768 u64_stats_update_begin(&stats->syncp);
769 stats->usage_cntrs[*index]++;
770 u64_stats_update_end(&stats->syncp);
771 return flow;
772 }
773 }
774
775 return NULL;
776}
777
778/*
779 * mask_cache maps flow to probable mask. This cache is not tightly
780 * coupled cache, It means updates to mask list can result in inconsistent
781 * cache entry in mask cache.
782 * This is per cpu cache and is divided in MC_HASH_SEGS segments.
783 * In case of a hash collision the entry is hashed in next segment.
784 * */
785struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
786 const struct sw_flow_key *key,
787 u32 skb_hash,
788 u32 *n_mask_hit,
789 u32 *n_cache_hit)
790{
791 struct mask_cache *mc = rcu_dereference(tbl->mask_cache);
792 struct mask_array *ma = rcu_dereference(tbl->mask_array);
793 struct table_instance *ti = rcu_dereference(tbl->ti);
794 struct mask_cache_entry *entries, *ce;
795 struct sw_flow *flow;
796 u32 hash;
797 int seg;
798
799 *n_mask_hit = 0;
800 *n_cache_hit = 0;
801 if (unlikely(!skb_hash || mc->cache_size == 0)) {
802 u32 mask_index = 0;
803 u32 cache = 0;
804
805 return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache,
806 &mask_index);
807 }
808
809 /* Pre and post recirulation flows usually have the same skb_hash
810 * value. To avoid hash collisions, rehash the 'skb_hash' with
811 * 'recirc_id'. */
812 if (key->recirc_id)
813 skb_hash = jhash_1word(skb_hash, key->recirc_id);
814
815 ce = NULL;
816 hash = skb_hash;
817 entries = this_cpu_ptr(mc->mask_cache);
818
819 /* Find the cache entry 'ce' to operate on. */
820 for (seg = 0; seg < MC_HASH_SEGS; seg++) {
821 int index = hash & (mc->cache_size - 1);
822 struct mask_cache_entry *e;
823
824 e = &entries[index];
825 if (e->skb_hash == skb_hash) {
826 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
827 n_cache_hit, &e->mask_index);
828 if (!flow)
829 e->skb_hash = 0;
830 return flow;
831 }
832
833 if (!ce || e->skb_hash < ce->skb_hash)
834 ce = e; /* A better replacement cache candidate. */
835
836 hash >>= MC_HASH_SHIFT;
837 }
838
839 /* Cache miss, do full lookup. */
840 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit,
841 &ce->mask_index);
842 if (flow)
843 ce->skb_hash = skb_hash;
844
845 *n_cache_hit = 0;
846 return flow;
847}
848
849struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
850 const struct sw_flow_key *key)
851{
852 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
853 struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
854 u32 __always_unused n_mask_hit;
855 u32 __always_unused n_cache_hit;
856 struct sw_flow *flow;
857 u32 index = 0;
858
859 /* This function gets called trough the netlink interface and therefore
860 * is preemptible. However, flow_lookup() function needs to be called
861 * with BH disabled due to CPU specific variables.
862 */
863 local_bh_disable();
864 flow = flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index);
865 local_bh_enable();
866 return flow;
867}
868
869struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
870 const struct sw_flow_match *match)
871{
872 struct mask_array *ma = ovsl_dereference(tbl->mask_array);
873 int i;
874
875 /* Always called under ovs-mutex. */
876 for (i = 0; i < ma->max; i++) {
877 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
878 u32 __always_unused n_mask_hit;
879 struct sw_flow_mask *mask;
880 struct sw_flow *flow;
881
882 mask = ovsl_dereference(ma->masks[i]);
883 if (!mask)
884 continue;
885
886 flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit);
887 if (flow && ovs_identifier_is_key(&flow->id) &&
888 ovs_flow_cmp_unmasked_key(flow, match)) {
889 return flow;
890 }
891 }
892
893 return NULL;
894}
895
896static u32 ufid_hash(const struct sw_flow_id *sfid)
897{
898 return jhash(sfid->ufid, sfid->ufid_len, 0);
899}
900
901static bool ovs_flow_cmp_ufid(const struct sw_flow *flow,
902 const struct sw_flow_id *sfid)
903{
904 if (flow->id.ufid_len != sfid->ufid_len)
905 return false;
906
907 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
908}
909
910bool ovs_flow_cmp(const struct sw_flow *flow,
911 const struct sw_flow_match *match)
912{
913 if (ovs_identifier_is_ufid(&flow->id))
914 return flow_cmp_masked_key(flow, match->key, &match->range);
915
916 return ovs_flow_cmp_unmasked_key(flow, match);
917}
918
919struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
920 const struct sw_flow_id *ufid)
921{
922 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti);
923 struct sw_flow *flow;
924 struct hlist_head *head;
925 u32 hash;
926
927 hash = ufid_hash(ufid);
928 head = find_bucket(ti, hash);
929 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver],
930 lockdep_ovsl_is_held()) {
931 if (flow->ufid_table.hash == hash &&
932 ovs_flow_cmp_ufid(flow, ufid))
933 return flow;
934 }
935 return NULL;
936}
937
938int ovs_flow_tbl_num_masks(const struct flow_table *table)
939{
940 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
941 return READ_ONCE(ma->count);
942}
943
944u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table)
945{
946 struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
947
948 return READ_ONCE(mc->cache_size);
949}
950
951static struct table_instance *table_instance_expand(struct table_instance *ti,
952 bool ufid)
953{
954 return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
955}
956
957/* Must be called with OVS mutex held. */
958void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
959{
960 struct table_instance *ti = ovsl_dereference(table->ti);
961 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
962
963 BUG_ON(table->count == 0);
964 table_instance_flow_free(table, ti, ufid_ti, flow);
965}
966
967static struct sw_flow_mask *mask_alloc(void)
968{
969 struct sw_flow_mask *mask;
970
971 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
972 if (mask)
973 mask->ref_count = 1;
974
975 return mask;
976}
977
978static bool mask_equal(const struct sw_flow_mask *a,
979 const struct sw_flow_mask *b)
980{
981 const u8 *a_ = (const u8 *)&a->key + a->range.start;
982 const u8 *b_ = (const u8 *)&b->key + b->range.start;
983
984 return (a->range.end == b->range.end)
985 && (a->range.start == b->range.start)
986 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
987}
988
989static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
990 const struct sw_flow_mask *mask)
991{
992 struct mask_array *ma;
993 int i;
994
995 ma = ovsl_dereference(tbl->mask_array);
996 for (i = 0; i < ma->max; i++) {
997 struct sw_flow_mask *t;
998 t = ovsl_dereference(ma->masks[i]);
999
1000 if (t && mask_equal(mask, t))
1001 return t;
1002 }
1003
1004 return NULL;
1005}
1006
1007/* Add 'mask' into the mask list, if it is not already there. */
1008static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
1009 const struct sw_flow_mask *new)
1010{
1011 struct sw_flow_mask *mask;
1012
1013 mask = flow_mask_find(tbl, new);
1014 if (!mask) {
1015 /* Allocate a new mask if none exsits. */
1016 mask = mask_alloc();
1017 if (!mask)
1018 return -ENOMEM;
1019 mask->key = new->key;
1020 mask->range = new->range;
1021
1022 /* Add mask to mask-list. */
1023 if (tbl_mask_array_add_mask(tbl, mask)) {
1024 kfree(mask);
1025 return -ENOMEM;
1026 }
1027 } else {
1028 BUG_ON(!mask->ref_count);
1029 mask->ref_count++;
1030 }
1031
1032 flow->mask = mask;
1033 return 0;
1034}
1035
1036/* Must be called with OVS mutex held. */
1037static void flow_key_insert(struct flow_table *table, struct sw_flow *flow)
1038{
1039 struct table_instance *new_ti = NULL;
1040 struct table_instance *ti;
1041
1042 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range);
1043 ti = ovsl_dereference(table->ti);
1044 table_instance_insert(ti, flow);
1045 table->count++;
1046
1047 /* Expand table, if necessary, to make room. */
1048 if (table->count > ti->n_buckets)
1049 new_ti = table_instance_expand(ti, false);
1050 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
1051 new_ti = table_instance_rehash(ti, ti->n_buckets, false);
1052
1053 if (new_ti) {
1054 rcu_assign_pointer(table->ti, new_ti);
1055 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
1056 table->last_rehash = jiffies;
1057 }
1058}
1059
1060/* Must be called with OVS mutex held. */
1061static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow)
1062{
1063 struct table_instance *ti;
1064
1065 flow->ufid_table.hash = ufid_hash(&flow->id);
1066 ti = ovsl_dereference(table->ufid_ti);
1067 ufid_table_instance_insert(ti, flow);
1068 table->ufid_count++;
1069
1070 /* Expand table, if necessary, to make room. */
1071 if (table->ufid_count > ti->n_buckets) {
1072 struct table_instance *new_ti;
1073
1074 new_ti = table_instance_expand(ti, true);
1075 if (new_ti) {
1076 rcu_assign_pointer(table->ufid_ti, new_ti);
1077 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
1078 }
1079 }
1080}
1081
1082/* Must be called with OVS mutex held. */
1083int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
1084 const struct sw_flow_mask *mask)
1085{
1086 int err;
1087
1088 err = flow_mask_insert(table, flow, mask);
1089 if (err)
1090 return err;
1091 flow_key_insert(table, flow);
1092 if (ovs_identifier_is_ufid(&flow->id))
1093 flow_ufid_insert(table, flow);
1094
1095 return 0;
1096}
1097
1098static int compare_mask_and_count(const void *a, const void *b)
1099{
1100 const struct mask_count *mc_a = a;
1101 const struct mask_count *mc_b = b;
1102
1103 return (s64)mc_b->counter - (s64)mc_a->counter;
1104}
1105
1106/* Must be called with OVS mutex held. */
1107void ovs_flow_masks_rebalance(struct flow_table *table)
1108{
1109 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
1110 struct mask_count *masks_and_count;
1111 struct mask_array *new;
1112 int masks_entries = 0;
1113 int i;
1114
1115 /* Build array of all current entries with use counters. */
1116 masks_and_count = kmalloc_array(ma->max, sizeof(*masks_and_count),
1117 GFP_KERNEL);
1118 if (!masks_and_count)
1119 return;
1120
1121 for (i = 0; i < ma->max; i++) {
1122 struct sw_flow_mask *mask;
1123 int cpu;
1124
1125 mask = rcu_dereference_ovsl(ma->masks[i]);
1126 if (unlikely(!mask))
1127 break;
1128
1129 masks_and_count[i].index = i;
1130 masks_and_count[i].counter = 0;
1131
1132 for_each_possible_cpu(cpu) {
1133 struct mask_array_stats *stats;
1134 unsigned int start;
1135 u64 counter;
1136
1137 stats = per_cpu_ptr(ma->masks_usage_stats, cpu);
1138 do {
1139 start = u64_stats_fetch_begin(&stats->syncp);
1140 counter = stats->usage_cntrs[i];
1141 } while (u64_stats_fetch_retry(&stats->syncp, start));
1142
1143 masks_and_count[i].counter += counter;
1144 }
1145
1146 /* Subtract the zero count value. */
1147 masks_and_count[i].counter -= ma->masks_usage_zero_cntr[i];
1148
1149 /* Rather than calling tbl_mask_array_reset_counters()
1150 * below when no change is needed, do it inline here.
1151 */
1152 ma->masks_usage_zero_cntr[i] += masks_and_count[i].counter;
1153 }
1154
1155 if (i == 0)
1156 goto free_mask_entries;
1157
1158 /* Sort the entries */
1159 masks_entries = i;
1160 sort(masks_and_count, masks_entries, sizeof(*masks_and_count),
1161 compare_mask_and_count, NULL);
1162
1163 /* If the order is the same, nothing to do... */
1164 for (i = 0; i < masks_entries; i++) {
1165 if (i != masks_and_count[i].index)
1166 break;
1167 }
1168 if (i == masks_entries)
1169 goto free_mask_entries;
1170
1171 /* Rebuilt the new list in order of usage. */
1172 new = tbl_mask_array_alloc(ma->max);
1173 if (!new)
1174 goto free_mask_entries;
1175
1176 for (i = 0; i < masks_entries; i++) {
1177 int index = masks_and_count[i].index;
1178
1179 if (ovsl_dereference(ma->masks[index]))
1180 new->masks[new->count++] = ma->masks[index];
1181 }
1182
1183 rcu_assign_pointer(table->mask_array, new);
1184 call_rcu(&ma->rcu, mask_array_rcu_cb);
1185
1186free_mask_entries:
1187 kfree(masks_and_count);
1188}
1189
1190/* Initializes the flow module.
1191 * Returns zero if successful or a negative error code. */
1192int ovs_flow_init(void)
1193{
1194 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
1195 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
1196
1197 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
1198 + (nr_cpu_ids
1199 * sizeof(struct sw_flow_stats *)),
1200 0, 0, NULL);
1201 if (flow_cache == NULL)
1202 return -ENOMEM;
1203
1204 flow_stats_cache
1205 = kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats),
1206 0, SLAB_HWCACHE_ALIGN, NULL);
1207 if (flow_stats_cache == NULL) {
1208 kmem_cache_destroy(flow_cache);
1209 flow_cache = NULL;
1210 return -ENOMEM;
1211 }
1212
1213 return 0;
1214}
1215
1216/* Uninitializes the flow module. */
1217void ovs_flow_exit(void)
1218{
1219 kmem_cache_destroy(flow_stats_cache);
1220 kmem_cache_destroy(flow_cache);
1221}