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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 <net/ip.h>
33#include <net/ipv6.h>
34#include <net/ndisc.h>
35
36#define TBL_MIN_BUCKETS 1024
37#define REHASH_INTERVAL (10 * 60 * HZ)
38
39static struct kmem_cache *flow_cache;
40struct kmem_cache *flow_stats_cache __read_mostly;
41
42static u16 range_n_bytes(const struct sw_flow_key_range *range)
43{
44 return range->end - range->start;
45}
46
47void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
48 bool full, const struct sw_flow_mask *mask)
49{
50 int start = full ? 0 : mask->range.start;
51 int len = full ? sizeof *dst : range_n_bytes(&mask->range);
52 const long *m = (const long *)((const u8 *)&mask->key + start);
53 const long *s = (const long *)((const u8 *)src + start);
54 long *d = (long *)((u8 *)dst + start);
55 int i;
56
57 /* If 'full' is true then all of 'dst' is fully initialized. Otherwise,
58 * if 'full' is false the memory outside of the 'mask->range' is left
59 * uninitialized. This can be used as an optimization when further
60 * operations on 'dst' only use contents within 'mask->range'.
61 */
62 for (i = 0; i < len; i += sizeof(long))
63 *d++ = *s++ & *m++;
64}
65
66struct sw_flow *ovs_flow_alloc(void)
67{
68 struct sw_flow *flow;
69 struct sw_flow_stats *stats;
70
71 flow = kmem_cache_zalloc(flow_cache, GFP_KERNEL);
72 if (!flow)
73 return ERR_PTR(-ENOMEM);
74
75 flow->stats_last_writer = -1;
76
77 /* Initialize the default stat node. */
78 stats = kmem_cache_alloc_node(flow_stats_cache,
79 GFP_KERNEL | __GFP_ZERO,
80 node_online(0) ? 0 : NUMA_NO_NODE);
81 if (!stats)
82 goto err;
83
84 spin_lock_init(&stats->lock);
85
86 RCU_INIT_POINTER(flow->stats[0], stats);
87
88 cpumask_set_cpu(0, &flow->cpu_used_mask);
89
90 return flow;
91err:
92 kmem_cache_free(flow_cache, flow);
93 return ERR_PTR(-ENOMEM);
94}
95
96int ovs_flow_tbl_count(const struct flow_table *table)
97{
98 return table->count;
99}
100
101static void flow_free(struct sw_flow *flow)
102{
103 int cpu;
104
105 if (ovs_identifier_is_key(&flow->id))
106 kfree(flow->id.unmasked_key);
107 if (flow->sf_acts)
108 ovs_nla_free_flow_actions((struct sw_flow_actions __force *)flow->sf_acts);
109 /* We open code this to make sure cpu 0 is always considered */
110 for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask))
111 if (flow->stats[cpu])
112 kmem_cache_free(flow_stats_cache,
113 (struct sw_flow_stats __force *)flow->stats[cpu]);
114 kmem_cache_free(flow_cache, flow);
115}
116
117static void rcu_free_flow_callback(struct rcu_head *rcu)
118{
119 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
120
121 flow_free(flow);
122}
123
124void ovs_flow_free(struct sw_flow *flow, bool deferred)
125{
126 if (!flow)
127 return;
128
129 if (deferred)
130 call_rcu(&flow->rcu, rcu_free_flow_callback);
131 else
132 flow_free(flow);
133}
134
135static void __table_instance_destroy(struct table_instance *ti)
136{
137 kvfree(ti->buckets);
138 kfree(ti);
139}
140
141static struct table_instance *table_instance_alloc(int new_size)
142{
143 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
144 int i;
145
146 if (!ti)
147 return NULL;
148
149 ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
150 GFP_KERNEL);
151 if (!ti->buckets) {
152 kfree(ti);
153 return NULL;
154 }
155
156 for (i = 0; i < new_size; i++)
157 INIT_HLIST_HEAD(&ti->buckets[i]);
158
159 ti->n_buckets = new_size;
160 ti->node_ver = 0;
161 ti->keep_flows = false;
162 get_random_bytes(&ti->hash_seed, sizeof(u32));
163
164 return ti;
165}
166
167int ovs_flow_tbl_init(struct flow_table *table)
168{
169 struct table_instance *ti, *ufid_ti;
170
171 ti = table_instance_alloc(TBL_MIN_BUCKETS);
172
173 if (!ti)
174 return -ENOMEM;
175
176 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
177 if (!ufid_ti)
178 goto free_ti;
179
180 rcu_assign_pointer(table->ti, ti);
181 rcu_assign_pointer(table->ufid_ti, ufid_ti);
182 INIT_LIST_HEAD(&table->mask_list);
183 table->last_rehash = jiffies;
184 table->count = 0;
185 table->ufid_count = 0;
186 return 0;
187
188free_ti:
189 __table_instance_destroy(ti);
190 return -ENOMEM;
191}
192
193static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
194{
195 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
196
197 __table_instance_destroy(ti);
198}
199
200static void table_instance_destroy(struct table_instance *ti,
201 struct table_instance *ufid_ti,
202 bool deferred)
203{
204 int i;
205
206 if (!ti)
207 return;
208
209 BUG_ON(!ufid_ti);
210 if (ti->keep_flows)
211 goto skip_flows;
212
213 for (i = 0; i < ti->n_buckets; i++) {
214 struct sw_flow *flow;
215 struct hlist_head *head = &ti->buckets[i];
216 struct hlist_node *n;
217 int ver = ti->node_ver;
218 int ufid_ver = ufid_ti->node_ver;
219
220 hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) {
221 hlist_del_rcu(&flow->flow_table.node[ver]);
222 if (ovs_identifier_is_ufid(&flow->id))
223 hlist_del_rcu(&flow->ufid_table.node[ufid_ver]);
224 ovs_flow_free(flow, deferred);
225 }
226 }
227
228skip_flows:
229 if (deferred) {
230 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
231 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
232 } else {
233 __table_instance_destroy(ti);
234 __table_instance_destroy(ufid_ti);
235 }
236}
237
238/* No need for locking this function is called from RCU callback or
239 * error path.
240 */
241void ovs_flow_tbl_destroy(struct flow_table *table)
242{
243 struct table_instance *ti = rcu_dereference_raw(table->ti);
244 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
245
246 table_instance_destroy(ti, ufid_ti, false);
247}
248
249struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
250 u32 *bucket, u32 *last)
251{
252 struct sw_flow *flow;
253 struct hlist_head *head;
254 int ver;
255 int i;
256
257 ver = ti->node_ver;
258 while (*bucket < ti->n_buckets) {
259 i = 0;
260 head = &ti->buckets[*bucket];
261 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
262 if (i < *last) {
263 i++;
264 continue;
265 }
266 *last = i + 1;
267 return flow;
268 }
269 (*bucket)++;
270 *last = 0;
271 }
272
273 return NULL;
274}
275
276static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
277{
278 hash = jhash_1word(hash, ti->hash_seed);
279 return &ti->buckets[hash & (ti->n_buckets - 1)];
280}
281
282static void table_instance_insert(struct table_instance *ti,
283 struct sw_flow *flow)
284{
285 struct hlist_head *head;
286
287 head = find_bucket(ti, flow->flow_table.hash);
288 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head);
289}
290
291static void ufid_table_instance_insert(struct table_instance *ti,
292 struct sw_flow *flow)
293{
294 struct hlist_head *head;
295
296 head = find_bucket(ti, flow->ufid_table.hash);
297 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head);
298}
299
300static void flow_table_copy_flows(struct table_instance *old,
301 struct table_instance *new, bool ufid)
302{
303 int old_ver;
304 int i;
305
306 old_ver = old->node_ver;
307 new->node_ver = !old_ver;
308
309 /* Insert in new table. */
310 for (i = 0; i < old->n_buckets; i++) {
311 struct sw_flow *flow;
312 struct hlist_head *head = &old->buckets[i];
313
314 if (ufid)
315 hlist_for_each_entry(flow, head,
316 ufid_table.node[old_ver])
317 ufid_table_instance_insert(new, flow);
318 else
319 hlist_for_each_entry(flow, head,
320 flow_table.node[old_ver])
321 table_instance_insert(new, flow);
322 }
323
324 old->keep_flows = true;
325}
326
327static struct table_instance *table_instance_rehash(struct table_instance *ti,
328 int n_buckets, bool ufid)
329{
330 struct table_instance *new_ti;
331
332 new_ti = table_instance_alloc(n_buckets);
333 if (!new_ti)
334 return NULL;
335
336 flow_table_copy_flows(ti, new_ti, ufid);
337
338 return new_ti;
339}
340
341int ovs_flow_tbl_flush(struct flow_table *flow_table)
342{
343 struct table_instance *old_ti, *new_ti;
344 struct table_instance *old_ufid_ti, *new_ufid_ti;
345
346 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
347 if (!new_ti)
348 return -ENOMEM;
349 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
350 if (!new_ufid_ti)
351 goto err_free_ti;
352
353 old_ti = ovsl_dereference(flow_table->ti);
354 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti);
355
356 rcu_assign_pointer(flow_table->ti, new_ti);
357 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
358 flow_table->last_rehash = jiffies;
359 flow_table->count = 0;
360 flow_table->ufid_count = 0;
361
362 table_instance_destroy(old_ti, old_ufid_ti, true);
363 return 0;
364
365err_free_ti:
366 __table_instance_destroy(new_ti);
367 return -ENOMEM;
368}
369
370static u32 flow_hash(const struct sw_flow_key *key,
371 const struct sw_flow_key_range *range)
372{
373 int key_start = range->start;
374 int key_end = range->end;
375 const u32 *hash_key = (const u32 *)((const u8 *)key + key_start);
376 int hash_u32s = (key_end - key_start) >> 2;
377
378 /* Make sure number of hash bytes are multiple of u32. */
379 BUILD_BUG_ON(sizeof(long) % sizeof(u32));
380
381 return jhash2(hash_key, hash_u32s, 0);
382}
383
384static int flow_key_start(const struct sw_flow_key *key)
385{
386 if (key->tun_proto)
387 return 0;
388 else
389 return rounddown(offsetof(struct sw_flow_key, phy),
390 sizeof(long));
391}
392
393static bool cmp_key(const struct sw_flow_key *key1,
394 const struct sw_flow_key *key2,
395 int key_start, int key_end)
396{
397 const long *cp1 = (const long *)((const u8 *)key1 + key_start);
398 const long *cp2 = (const long *)((const u8 *)key2 + key_start);
399 long diffs = 0;
400 int i;
401
402 for (i = key_start; i < key_end; i += sizeof(long))
403 diffs |= *cp1++ ^ *cp2++;
404
405 return diffs == 0;
406}
407
408static bool flow_cmp_masked_key(const struct sw_flow *flow,
409 const struct sw_flow_key *key,
410 const struct sw_flow_key_range *range)
411{
412 return cmp_key(&flow->key, key, range->start, range->end);
413}
414
415static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
416 const struct sw_flow_match *match)
417{
418 struct sw_flow_key *key = match->key;
419 int key_start = flow_key_start(key);
420 int key_end = match->range.end;
421
422 BUG_ON(ovs_identifier_is_ufid(&flow->id));
423 return cmp_key(flow->id.unmasked_key, key, key_start, key_end);
424}
425
426static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
427 const struct sw_flow_key *unmasked,
428 const struct sw_flow_mask *mask)
429{
430 struct sw_flow *flow;
431 struct hlist_head *head;
432 u32 hash;
433 struct sw_flow_key masked_key;
434
435 ovs_flow_mask_key(&masked_key, unmasked, false, mask);
436 hash = flow_hash(&masked_key, &mask->range);
437 head = find_bucket(ti, hash);
438 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) {
439 if (flow->mask == mask && flow->flow_table.hash == hash &&
440 flow_cmp_masked_key(flow, &masked_key, &mask->range))
441 return flow;
442 }
443 return NULL;
444}
445
446struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
447 const struct sw_flow_key *key,
448 u32 *n_mask_hit)
449{
450 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
451 struct sw_flow_mask *mask;
452 struct sw_flow *flow;
453
454 *n_mask_hit = 0;
455 list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
456 (*n_mask_hit)++;
457 flow = masked_flow_lookup(ti, key, mask);
458 if (flow) /* Found */
459 return flow;
460 }
461 return NULL;
462}
463
464struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
465 const struct sw_flow_key *key)
466{
467 u32 __always_unused n_mask_hit;
468
469 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
470}
471
472struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
473 const struct sw_flow_match *match)
474{
475 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
476 struct sw_flow_mask *mask;
477 struct sw_flow *flow;
478
479 /* Always called under ovs-mutex. */
480 list_for_each_entry(mask, &tbl->mask_list, list) {
481 flow = masked_flow_lookup(ti, match->key, mask);
482 if (flow && ovs_identifier_is_key(&flow->id) &&
483 ovs_flow_cmp_unmasked_key(flow, match))
484 return flow;
485 }
486 return NULL;
487}
488
489static u32 ufid_hash(const struct sw_flow_id *sfid)
490{
491 return jhash(sfid->ufid, sfid->ufid_len, 0);
492}
493
494static bool ovs_flow_cmp_ufid(const struct sw_flow *flow,
495 const struct sw_flow_id *sfid)
496{
497 if (flow->id.ufid_len != sfid->ufid_len)
498 return false;
499
500 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
501}
502
503bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match)
504{
505 if (ovs_identifier_is_ufid(&flow->id))
506 return flow_cmp_masked_key(flow, match->key, &match->range);
507
508 return ovs_flow_cmp_unmasked_key(flow, match);
509}
510
511struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
512 const struct sw_flow_id *ufid)
513{
514 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti);
515 struct sw_flow *flow;
516 struct hlist_head *head;
517 u32 hash;
518
519 hash = ufid_hash(ufid);
520 head = find_bucket(ti, hash);
521 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) {
522 if (flow->ufid_table.hash == hash &&
523 ovs_flow_cmp_ufid(flow, ufid))
524 return flow;
525 }
526 return NULL;
527}
528
529int ovs_flow_tbl_num_masks(const struct flow_table *table)
530{
531 struct sw_flow_mask *mask;
532 int num = 0;
533
534 list_for_each_entry(mask, &table->mask_list, list)
535 num++;
536
537 return num;
538}
539
540static struct table_instance *table_instance_expand(struct table_instance *ti,
541 bool ufid)
542{
543 return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
544}
545
546/* Remove 'mask' from the mask list, if it is not needed any more. */
547static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
548{
549 if (mask) {
550 /* ovs-lock is required to protect mask-refcount and
551 * mask list.
552 */
553 ASSERT_OVSL();
554 BUG_ON(!mask->ref_count);
555 mask->ref_count--;
556
557 if (!mask->ref_count) {
558 list_del_rcu(&mask->list);
559 kfree_rcu(mask, rcu);
560 }
561 }
562}
563
564/* Must be called with OVS mutex held. */
565void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
566{
567 struct table_instance *ti = ovsl_dereference(table->ti);
568 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
569
570 BUG_ON(table->count == 0);
571 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
572 table->count--;
573 if (ovs_identifier_is_ufid(&flow->id)) {
574 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
575 table->ufid_count--;
576 }
577
578 /* RCU delete the mask. 'flow->mask' is not NULLed, as it should be
579 * accessible as long as the RCU read lock is held.
580 */
581 flow_mask_remove(table, flow->mask);
582}
583
584static struct sw_flow_mask *mask_alloc(void)
585{
586 struct sw_flow_mask *mask;
587
588 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
589 if (mask)
590 mask->ref_count = 1;
591
592 return mask;
593}
594
595static bool mask_equal(const struct sw_flow_mask *a,
596 const struct sw_flow_mask *b)
597{
598 const u8 *a_ = (const u8 *)&a->key + a->range.start;
599 const u8 *b_ = (const u8 *)&b->key + b->range.start;
600
601 return (a->range.end == b->range.end)
602 && (a->range.start == b->range.start)
603 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
604}
605
606static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
607 const struct sw_flow_mask *mask)
608{
609 struct list_head *ml;
610
611 list_for_each(ml, &tbl->mask_list) {
612 struct sw_flow_mask *m;
613 m = container_of(ml, struct sw_flow_mask, list);
614 if (mask_equal(mask, m))
615 return m;
616 }
617
618 return NULL;
619}
620
621/* Add 'mask' into the mask list, if it is not already there. */
622static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
623 const struct sw_flow_mask *new)
624{
625 struct sw_flow_mask *mask;
626 mask = flow_mask_find(tbl, new);
627 if (!mask) {
628 /* Allocate a new mask if none exsits. */
629 mask = mask_alloc();
630 if (!mask)
631 return -ENOMEM;
632 mask->key = new->key;
633 mask->range = new->range;
634 list_add_rcu(&mask->list, &tbl->mask_list);
635 } else {
636 BUG_ON(!mask->ref_count);
637 mask->ref_count++;
638 }
639
640 flow->mask = mask;
641 return 0;
642}
643
644/* Must be called with OVS mutex held. */
645static void flow_key_insert(struct flow_table *table, struct sw_flow *flow)
646{
647 struct table_instance *new_ti = NULL;
648 struct table_instance *ti;
649
650 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range);
651 ti = ovsl_dereference(table->ti);
652 table_instance_insert(ti, flow);
653 table->count++;
654
655 /* Expand table, if necessary, to make room. */
656 if (table->count > ti->n_buckets)
657 new_ti = table_instance_expand(ti, false);
658 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
659 new_ti = table_instance_rehash(ti, ti->n_buckets, false);
660
661 if (new_ti) {
662 rcu_assign_pointer(table->ti, new_ti);
663 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
664 table->last_rehash = jiffies;
665 }
666}
667
668/* Must be called with OVS mutex held. */
669static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow)
670{
671 struct table_instance *ti;
672
673 flow->ufid_table.hash = ufid_hash(&flow->id);
674 ti = ovsl_dereference(table->ufid_ti);
675 ufid_table_instance_insert(ti, flow);
676 table->ufid_count++;
677
678 /* Expand table, if necessary, to make room. */
679 if (table->ufid_count > ti->n_buckets) {
680 struct table_instance *new_ti;
681
682 new_ti = table_instance_expand(ti, true);
683 if (new_ti) {
684 rcu_assign_pointer(table->ufid_ti, new_ti);
685 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
686 }
687 }
688}
689
690/* Must be called with OVS mutex held. */
691int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
692 const struct sw_flow_mask *mask)
693{
694 int err;
695
696 err = flow_mask_insert(table, flow, mask);
697 if (err)
698 return err;
699 flow_key_insert(table, flow);
700 if (ovs_identifier_is_ufid(&flow->id))
701 flow_ufid_insert(table, flow);
702
703 return 0;
704}
705
706/* Initializes the flow module.
707 * Returns zero if successful or a negative error code. */
708int ovs_flow_init(void)
709{
710 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
711 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
712
713 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
714 + (nr_cpu_ids
715 * sizeof(struct sw_flow_stats *)),
716 0, 0, NULL);
717 if (flow_cache == NULL)
718 return -ENOMEM;
719
720 flow_stats_cache
721 = kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats),
722 0, SLAB_HWCACHE_ALIGN, NULL);
723 if (flow_stats_cache == NULL) {
724 kmem_cache_destroy(flow_cache);
725 flow_cache = NULL;
726 return -ENOMEM;
727 }
728
729 return 0;
730}
731
732/* Uninitializes the flow module. */
733void ovs_flow_exit(void)
734{
735 kmem_cache_destroy(flow_stats_cache);
736 kmem_cache_destroy(flow_cache);
737}
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 *)flow->sf_acts);
115 /* We open code this to make sure cpu 0 is always considered */
116 for (cpu = 0; cpu < nr_cpu_ids; cpu = cpumask_next(cpu, &flow->cpu_used_mask))
117 if (flow->stats[cpu])
118 kmem_cache_free(flow_stats_cache,
119 (struct sw_flow_stats __force *)flow->stats[cpu]);
120 kmem_cache_free(flow_cache, flow);
121}
122
123static void rcu_free_flow_callback(struct rcu_head *rcu)
124{
125 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
126
127 flow_free(flow);
128}
129
130void ovs_flow_free(struct sw_flow *flow, bool deferred)
131{
132 if (!flow)
133 return;
134
135 if (deferred)
136 call_rcu(&flow->rcu, rcu_free_flow_callback);
137 else
138 flow_free(flow);
139}
140
141static void __table_instance_destroy(struct table_instance *ti)
142{
143 kvfree(ti->buckets);
144 kfree(ti);
145}
146
147static struct table_instance *table_instance_alloc(int new_size)
148{
149 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
150 int i;
151
152 if (!ti)
153 return NULL;
154
155 ti->buckets = kvmalloc_array(new_size, sizeof(struct hlist_head),
156 GFP_KERNEL);
157 if (!ti->buckets) {
158 kfree(ti);
159 return NULL;
160 }
161
162 for (i = 0; i < new_size; i++)
163 INIT_HLIST_HEAD(&ti->buckets[i]);
164
165 ti->n_buckets = new_size;
166 ti->node_ver = 0;
167 ti->keep_flows = false;
168 get_random_bytes(&ti->hash_seed, sizeof(u32));
169
170 return ti;
171}
172
173static void __mask_array_destroy(struct mask_array *ma)
174{
175 free_percpu(ma->masks_usage_cntr);
176 kfree(ma);
177}
178
179static void mask_array_rcu_cb(struct rcu_head *rcu)
180{
181 struct mask_array *ma = container_of(rcu, struct mask_array, rcu);
182
183 __mask_array_destroy(ma);
184}
185
186static void tbl_mask_array_reset_counters(struct mask_array *ma)
187{
188 int i, cpu;
189
190 /* As the per CPU counters are not atomic we can not go ahead and
191 * reset them from another CPU. To be able to still have an approximate
192 * zero based counter we store the value at reset, and subtract it
193 * later when processing.
194 */
195 for (i = 0; i < ma->max; i++) {
196 ma->masks_usage_zero_cntr[i] = 0;
197
198 for_each_possible_cpu(cpu) {
199 u64 *usage_counters = per_cpu_ptr(ma->masks_usage_cntr,
200 cpu);
201 unsigned int start;
202 u64 counter;
203
204 do {
205 start = u64_stats_fetch_begin_irq(&ma->syncp);
206 counter = usage_counters[i];
207 } while (u64_stats_fetch_retry_irq(&ma->syncp, start));
208
209 ma->masks_usage_zero_cntr[i] += counter;
210 }
211 }
212}
213
214static struct mask_array *tbl_mask_array_alloc(int size)
215{
216 struct mask_array *new;
217
218 size = max(MASK_ARRAY_SIZE_MIN, size);
219 new = kzalloc(sizeof(struct mask_array) +
220 sizeof(struct sw_flow_mask *) * size +
221 sizeof(u64) * size, GFP_KERNEL);
222 if (!new)
223 return NULL;
224
225 new->masks_usage_zero_cntr = (u64 *)((u8 *)new +
226 sizeof(struct mask_array) +
227 sizeof(struct sw_flow_mask *) *
228 size);
229
230 new->masks_usage_cntr = __alloc_percpu(sizeof(u64) * size,
231 __alignof__(u64));
232 if (!new->masks_usage_cntr) {
233 kfree(new);
234 return NULL;
235 }
236
237 new->count = 0;
238 new->max = size;
239
240 return new;
241}
242
243static int tbl_mask_array_realloc(struct flow_table *tbl, int size)
244{
245 struct mask_array *old;
246 struct mask_array *new;
247
248 new = tbl_mask_array_alloc(size);
249 if (!new)
250 return -ENOMEM;
251
252 old = ovsl_dereference(tbl->mask_array);
253 if (old) {
254 int i;
255
256 for (i = 0; i < old->max; i++) {
257 if (ovsl_dereference(old->masks[i]))
258 new->masks[new->count++] = old->masks[i];
259 }
260 call_rcu(&old->rcu, mask_array_rcu_cb);
261 }
262
263 rcu_assign_pointer(tbl->mask_array, new);
264
265 return 0;
266}
267
268static int tbl_mask_array_add_mask(struct flow_table *tbl,
269 struct sw_flow_mask *new)
270{
271 struct mask_array *ma = ovsl_dereference(tbl->mask_array);
272 int err, ma_count = READ_ONCE(ma->count);
273
274 if (ma_count >= ma->max) {
275 err = tbl_mask_array_realloc(tbl, ma->max +
276 MASK_ARRAY_SIZE_MIN);
277 if (err)
278 return err;
279
280 ma = ovsl_dereference(tbl->mask_array);
281 } else {
282 /* On every add or delete we need to reset the counters so
283 * every new mask gets a fair chance of being prioritized.
284 */
285 tbl_mask_array_reset_counters(ma);
286 }
287
288 BUG_ON(ovsl_dereference(ma->masks[ma_count]));
289
290 rcu_assign_pointer(ma->masks[ma_count], new);
291 WRITE_ONCE(ma->count, ma_count +1);
292
293 return 0;
294}
295
296static void tbl_mask_array_del_mask(struct flow_table *tbl,
297 struct sw_flow_mask *mask)
298{
299 struct mask_array *ma = ovsl_dereference(tbl->mask_array);
300 int i, ma_count = READ_ONCE(ma->count);
301
302 /* Remove the deleted mask pointers from the array */
303 for (i = 0; i < ma_count; i++) {
304 if (mask == ovsl_dereference(ma->masks[i]))
305 goto found;
306 }
307
308 BUG();
309 return;
310
311found:
312 WRITE_ONCE(ma->count, ma_count -1);
313
314 rcu_assign_pointer(ma->masks[i], ma->masks[ma_count -1]);
315 RCU_INIT_POINTER(ma->masks[ma_count -1], NULL);
316
317 kfree_rcu(mask, rcu);
318
319 /* Shrink the mask array if necessary. */
320 if (ma->max >= (MASK_ARRAY_SIZE_MIN * 2) &&
321 ma_count <= (ma->max / 3))
322 tbl_mask_array_realloc(tbl, ma->max / 2);
323 else
324 tbl_mask_array_reset_counters(ma);
325
326}
327
328/* Remove 'mask' from the mask list, if it is not needed any more. */
329static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
330{
331 if (mask) {
332 /* ovs-lock is required to protect mask-refcount and
333 * mask list.
334 */
335 ASSERT_OVSL();
336 BUG_ON(!mask->ref_count);
337 mask->ref_count--;
338
339 if (!mask->ref_count)
340 tbl_mask_array_del_mask(tbl, mask);
341 }
342}
343
344static void __mask_cache_destroy(struct mask_cache *mc)
345{
346 free_percpu(mc->mask_cache);
347 kfree(mc);
348}
349
350static void mask_cache_rcu_cb(struct rcu_head *rcu)
351{
352 struct mask_cache *mc = container_of(rcu, struct mask_cache, rcu);
353
354 __mask_cache_destroy(mc);
355}
356
357static struct mask_cache *tbl_mask_cache_alloc(u32 size)
358{
359 struct mask_cache_entry __percpu *cache = NULL;
360 struct mask_cache *new;
361
362 /* Only allow size to be 0, or a power of 2, and does not exceed
363 * percpu allocation size.
364 */
365 if ((!is_power_of_2(size) && size != 0) ||
366 (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
367 return NULL;
368
369 new = kzalloc(sizeof(*new), GFP_KERNEL);
370 if (!new)
371 return NULL;
372
373 new->cache_size = size;
374 if (new->cache_size > 0) {
375 cache = __alloc_percpu(array_size(sizeof(struct mask_cache_entry),
376 new->cache_size),
377 __alignof__(struct mask_cache_entry));
378 if (!cache) {
379 kfree(new);
380 return NULL;
381 }
382 }
383
384 new->mask_cache = cache;
385 return new;
386}
387int ovs_flow_tbl_masks_cache_resize(struct flow_table *table, u32 size)
388{
389 struct mask_cache *mc = rcu_dereference(table->mask_cache);
390 struct mask_cache *new;
391
392 if (size == mc->cache_size)
393 return 0;
394
395 if ((!is_power_of_2(size) && size != 0) ||
396 (size * sizeof(struct mask_cache_entry)) > PCPU_MIN_UNIT_SIZE)
397 return -EINVAL;
398
399 new = tbl_mask_cache_alloc(size);
400 if (!new)
401 return -ENOMEM;
402
403 rcu_assign_pointer(table->mask_cache, new);
404 call_rcu(&mc->rcu, mask_cache_rcu_cb);
405
406 return 0;
407}
408
409int ovs_flow_tbl_init(struct flow_table *table)
410{
411 struct table_instance *ti, *ufid_ti;
412 struct mask_cache *mc;
413 struct mask_array *ma;
414
415 mc = tbl_mask_cache_alloc(MC_DEFAULT_HASH_ENTRIES);
416 if (!mc)
417 return -ENOMEM;
418
419 ma = tbl_mask_array_alloc(MASK_ARRAY_SIZE_MIN);
420 if (!ma)
421 goto free_mask_cache;
422
423 ti = table_instance_alloc(TBL_MIN_BUCKETS);
424 if (!ti)
425 goto free_mask_array;
426
427 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
428 if (!ufid_ti)
429 goto free_ti;
430
431 rcu_assign_pointer(table->ti, ti);
432 rcu_assign_pointer(table->ufid_ti, ufid_ti);
433 rcu_assign_pointer(table->mask_array, ma);
434 rcu_assign_pointer(table->mask_cache, mc);
435 table->last_rehash = jiffies;
436 table->count = 0;
437 table->ufid_count = 0;
438 return 0;
439
440free_ti:
441 __table_instance_destroy(ti);
442free_mask_array:
443 __mask_array_destroy(ma);
444free_mask_cache:
445 __mask_cache_destroy(mc);
446 return -ENOMEM;
447}
448
449static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
450{
451 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
452
453 __table_instance_destroy(ti);
454}
455
456static void table_instance_flow_free(struct flow_table *table,
457 struct table_instance *ti,
458 struct table_instance *ufid_ti,
459 struct sw_flow *flow,
460 bool count)
461{
462 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
463 if (count)
464 table->count--;
465
466 if (ovs_identifier_is_ufid(&flow->id)) {
467 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
468
469 if (count)
470 table->ufid_count--;
471 }
472
473 flow_mask_remove(table, flow->mask);
474}
475
476/* Must be called with OVS mutex held. */
477void table_instance_flow_flush(struct flow_table *table,
478 struct table_instance *ti,
479 struct table_instance *ufid_ti)
480{
481 int i;
482
483 if (ti->keep_flows)
484 return;
485
486 for (i = 0; i < ti->n_buckets; i++) {
487 struct sw_flow *flow;
488 struct hlist_head *head = &ti->buckets[i];
489 struct hlist_node *n;
490
491 hlist_for_each_entry_safe(flow, n, head,
492 flow_table.node[ti->node_ver]) {
493
494 table_instance_flow_free(table, ti, ufid_ti,
495 flow, false);
496 ovs_flow_free(flow, true);
497 }
498 }
499}
500
501static void table_instance_destroy(struct table_instance *ti,
502 struct table_instance *ufid_ti)
503{
504 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
505 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
506}
507
508/* No need for locking this function is called from RCU callback or
509 * error path.
510 */
511void ovs_flow_tbl_destroy(struct flow_table *table)
512{
513 struct table_instance *ti = rcu_dereference_raw(table->ti);
514 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
515 struct mask_cache *mc = rcu_dereference_raw(table->mask_cache);
516 struct mask_array *ma = rcu_dereference_raw(table->mask_array);
517
518 call_rcu(&mc->rcu, mask_cache_rcu_cb);
519 call_rcu(&ma->rcu, mask_array_rcu_cb);
520 table_instance_destroy(ti, ufid_ti);
521}
522
523struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
524 u32 *bucket, u32 *last)
525{
526 struct sw_flow *flow;
527 struct hlist_head *head;
528 int ver;
529 int i;
530
531 ver = ti->node_ver;
532 while (*bucket < ti->n_buckets) {
533 i = 0;
534 head = &ti->buckets[*bucket];
535 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
536 if (i < *last) {
537 i++;
538 continue;
539 }
540 *last = i + 1;
541 return flow;
542 }
543 (*bucket)++;
544 *last = 0;
545 }
546
547 return NULL;
548}
549
550static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
551{
552 hash = jhash_1word(hash, ti->hash_seed);
553 return &ti->buckets[hash & (ti->n_buckets - 1)];
554}
555
556static void table_instance_insert(struct table_instance *ti,
557 struct sw_flow *flow)
558{
559 struct hlist_head *head;
560
561 head = find_bucket(ti, flow->flow_table.hash);
562 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head);
563}
564
565static void ufid_table_instance_insert(struct table_instance *ti,
566 struct sw_flow *flow)
567{
568 struct hlist_head *head;
569
570 head = find_bucket(ti, flow->ufid_table.hash);
571 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head);
572}
573
574static void flow_table_copy_flows(struct table_instance *old,
575 struct table_instance *new, bool ufid)
576{
577 int old_ver;
578 int i;
579
580 old_ver = old->node_ver;
581 new->node_ver = !old_ver;
582
583 /* Insert in new table. */
584 for (i = 0; i < old->n_buckets; i++) {
585 struct sw_flow *flow;
586 struct hlist_head *head = &old->buckets[i];
587
588 if (ufid)
589 hlist_for_each_entry_rcu(flow, head,
590 ufid_table.node[old_ver],
591 lockdep_ovsl_is_held())
592 ufid_table_instance_insert(new, flow);
593 else
594 hlist_for_each_entry_rcu(flow, head,
595 flow_table.node[old_ver],
596 lockdep_ovsl_is_held())
597 table_instance_insert(new, flow);
598 }
599
600 old->keep_flows = true;
601}
602
603static struct table_instance *table_instance_rehash(struct table_instance *ti,
604 int n_buckets, bool ufid)
605{
606 struct table_instance *new_ti;
607
608 new_ti = table_instance_alloc(n_buckets);
609 if (!new_ti)
610 return NULL;
611
612 flow_table_copy_flows(ti, new_ti, ufid);
613
614 return new_ti;
615}
616
617int ovs_flow_tbl_flush(struct flow_table *flow_table)
618{
619 struct table_instance *old_ti, *new_ti;
620 struct table_instance *old_ufid_ti, *new_ufid_ti;
621
622 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
623 if (!new_ti)
624 return -ENOMEM;
625 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
626 if (!new_ufid_ti)
627 goto err_free_ti;
628
629 old_ti = ovsl_dereference(flow_table->ti);
630 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti);
631
632 rcu_assign_pointer(flow_table->ti, new_ti);
633 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
634 flow_table->last_rehash = jiffies;
635 flow_table->count = 0;
636 flow_table->ufid_count = 0;
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 long diffs = 0;
674 int i;
675
676 for (i = key_start; i < key_end; i += sizeof(long))
677 diffs |= *cp1++ ^ *cp2++;
678
679 return diffs == 0;
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 */
727static struct sw_flow *flow_lookup(struct flow_table *tbl,
728 struct table_instance *ti,
729 struct mask_array *ma,
730 const struct sw_flow_key *key,
731 u32 *n_mask_hit,
732 u32 *n_cache_hit,
733 u32 *index)
734{
735 u64 *usage_counters = this_cpu_ptr(ma->masks_usage_cntr);
736 struct sw_flow *flow;
737 struct sw_flow_mask *mask;
738 int i;
739
740 if (likely(*index < ma->max)) {
741 mask = rcu_dereference_ovsl(ma->masks[*index]);
742 if (mask) {
743 flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
744 if (flow) {
745 u64_stats_update_begin(&ma->syncp);
746 usage_counters[*index]++;
747 u64_stats_update_end(&ma->syncp);
748 (*n_cache_hit)++;
749 return flow;
750 }
751 }
752 }
753
754 for (i = 0; i < ma->max; i++) {
755
756 if (i == *index)
757 continue;
758
759 mask = rcu_dereference_ovsl(ma->masks[i]);
760 if (unlikely(!mask))
761 break;
762
763 flow = masked_flow_lookup(ti, key, mask, n_mask_hit);
764 if (flow) { /* Found */
765 *index = i;
766 u64_stats_update_begin(&ma->syncp);
767 usage_counters[*index]++;
768 u64_stats_update_end(&ma->syncp);
769 return flow;
770 }
771 }
772
773 return NULL;
774}
775
776/*
777 * mask_cache maps flow to probable mask. This cache is not tightly
778 * coupled cache, It means updates to mask list can result in inconsistent
779 * cache entry in mask cache.
780 * This is per cpu cache and is divided in MC_HASH_SEGS segments.
781 * In case of a hash collision the entry is hashed in next segment.
782 * */
783struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
784 const struct sw_flow_key *key,
785 u32 skb_hash,
786 u32 *n_mask_hit,
787 u32 *n_cache_hit)
788{
789 struct mask_cache *mc = rcu_dereference(tbl->mask_cache);
790 struct mask_array *ma = rcu_dereference(tbl->mask_array);
791 struct table_instance *ti = rcu_dereference(tbl->ti);
792 struct mask_cache_entry *entries, *ce;
793 struct sw_flow *flow;
794 u32 hash;
795 int seg;
796
797 *n_mask_hit = 0;
798 *n_cache_hit = 0;
799 if (unlikely(!skb_hash || mc->cache_size == 0)) {
800 u32 mask_index = 0;
801 u32 cache = 0;
802
803 return flow_lookup(tbl, ti, ma, key, n_mask_hit, &cache,
804 &mask_index);
805 }
806
807 /* Pre and post recirulation flows usually have the same skb_hash
808 * value. To avoid hash collisions, rehash the 'skb_hash' with
809 * 'recirc_id'. */
810 if (key->recirc_id)
811 skb_hash = jhash_1word(skb_hash, key->recirc_id);
812
813 ce = NULL;
814 hash = skb_hash;
815 entries = this_cpu_ptr(mc->mask_cache);
816
817 /* Find the cache entry 'ce' to operate on. */
818 for (seg = 0; seg < MC_HASH_SEGS; seg++) {
819 int index = hash & (mc->cache_size - 1);
820 struct mask_cache_entry *e;
821
822 e = &entries[index];
823 if (e->skb_hash == skb_hash) {
824 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit,
825 n_cache_hit, &e->mask_index);
826 if (!flow)
827 e->skb_hash = 0;
828 return flow;
829 }
830
831 if (!ce || e->skb_hash < ce->skb_hash)
832 ce = e; /* A better replacement cache candidate. */
833
834 hash >>= MC_HASH_SHIFT;
835 }
836
837 /* Cache miss, do full lookup. */
838 flow = flow_lookup(tbl, ti, ma, key, n_mask_hit, n_cache_hit,
839 &ce->mask_index);
840 if (flow)
841 ce->skb_hash = skb_hash;
842
843 *n_cache_hit = 0;
844 return flow;
845}
846
847struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
848 const struct sw_flow_key *key)
849{
850 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
851 struct mask_array *ma = rcu_dereference_ovsl(tbl->mask_array);
852 u32 __always_unused n_mask_hit;
853 u32 __always_unused n_cache_hit;
854 u32 index = 0;
855
856 return flow_lookup(tbl, ti, ma, key, &n_mask_hit, &n_cache_hit, &index);
857}
858
859struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
860 const struct sw_flow_match *match)
861{
862 struct mask_array *ma = ovsl_dereference(tbl->mask_array);
863 int i;
864
865 /* Always called under ovs-mutex. */
866 for (i = 0; i < ma->max; i++) {
867 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
868 u32 __always_unused n_mask_hit;
869 struct sw_flow_mask *mask;
870 struct sw_flow *flow;
871
872 mask = ovsl_dereference(ma->masks[i]);
873 if (!mask)
874 continue;
875
876 flow = masked_flow_lookup(ti, match->key, mask, &n_mask_hit);
877 if (flow && ovs_identifier_is_key(&flow->id) &&
878 ovs_flow_cmp_unmasked_key(flow, match)) {
879 return flow;
880 }
881 }
882
883 return NULL;
884}
885
886static u32 ufid_hash(const struct sw_flow_id *sfid)
887{
888 return jhash(sfid->ufid, sfid->ufid_len, 0);
889}
890
891static bool ovs_flow_cmp_ufid(const struct sw_flow *flow,
892 const struct sw_flow_id *sfid)
893{
894 if (flow->id.ufid_len != sfid->ufid_len)
895 return false;
896
897 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
898}
899
900bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match)
901{
902 if (ovs_identifier_is_ufid(&flow->id))
903 return flow_cmp_masked_key(flow, match->key, &match->range);
904
905 return ovs_flow_cmp_unmasked_key(flow, match);
906}
907
908struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
909 const struct sw_flow_id *ufid)
910{
911 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti);
912 struct sw_flow *flow;
913 struct hlist_head *head;
914 u32 hash;
915
916 hash = ufid_hash(ufid);
917 head = find_bucket(ti, hash);
918 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver],
919 lockdep_ovsl_is_held()) {
920 if (flow->ufid_table.hash == hash &&
921 ovs_flow_cmp_ufid(flow, ufid))
922 return flow;
923 }
924 return NULL;
925}
926
927int ovs_flow_tbl_num_masks(const struct flow_table *table)
928{
929 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
930 return READ_ONCE(ma->count);
931}
932
933u32 ovs_flow_tbl_masks_cache_size(const struct flow_table *table)
934{
935 struct mask_cache *mc = rcu_dereference_ovsl(table->mask_cache);
936
937 return READ_ONCE(mc->cache_size);
938}
939
940static struct table_instance *table_instance_expand(struct table_instance *ti,
941 bool ufid)
942{
943 return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
944}
945
946/* Must be called with OVS mutex held. */
947void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
948{
949 struct table_instance *ti = ovsl_dereference(table->ti);
950 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
951
952 BUG_ON(table->count == 0);
953 table_instance_flow_free(table, ti, ufid_ti, flow, true);
954}
955
956static struct sw_flow_mask *mask_alloc(void)
957{
958 struct sw_flow_mask *mask;
959
960 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
961 if (mask)
962 mask->ref_count = 1;
963
964 return mask;
965}
966
967static bool mask_equal(const struct sw_flow_mask *a,
968 const struct sw_flow_mask *b)
969{
970 const u8 *a_ = (const u8 *)&a->key + a->range.start;
971 const u8 *b_ = (const u8 *)&b->key + b->range.start;
972
973 return (a->range.end == b->range.end)
974 && (a->range.start == b->range.start)
975 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
976}
977
978static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
979 const struct sw_flow_mask *mask)
980{
981 struct mask_array *ma;
982 int i;
983
984 ma = ovsl_dereference(tbl->mask_array);
985 for (i = 0; i < ma->max; i++) {
986 struct sw_flow_mask *t;
987 t = ovsl_dereference(ma->masks[i]);
988
989 if (t && mask_equal(mask, t))
990 return t;
991 }
992
993 return NULL;
994}
995
996/* Add 'mask' into the mask list, if it is not already there. */
997static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
998 const struct sw_flow_mask *new)
999{
1000 struct sw_flow_mask *mask;
1001
1002 mask = flow_mask_find(tbl, new);
1003 if (!mask) {
1004 /* Allocate a new mask if none exsits. */
1005 mask = mask_alloc();
1006 if (!mask)
1007 return -ENOMEM;
1008 mask->key = new->key;
1009 mask->range = new->range;
1010
1011 /* Add mask to mask-list. */
1012 if (tbl_mask_array_add_mask(tbl, mask)) {
1013 kfree(mask);
1014 return -ENOMEM;
1015 }
1016 } else {
1017 BUG_ON(!mask->ref_count);
1018 mask->ref_count++;
1019 }
1020
1021 flow->mask = mask;
1022 return 0;
1023}
1024
1025/* Must be called with OVS mutex held. */
1026static void flow_key_insert(struct flow_table *table, struct sw_flow *flow)
1027{
1028 struct table_instance *new_ti = NULL;
1029 struct table_instance *ti;
1030
1031 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range);
1032 ti = ovsl_dereference(table->ti);
1033 table_instance_insert(ti, flow);
1034 table->count++;
1035
1036 /* Expand table, if necessary, to make room. */
1037 if (table->count > ti->n_buckets)
1038 new_ti = table_instance_expand(ti, false);
1039 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
1040 new_ti = table_instance_rehash(ti, ti->n_buckets, false);
1041
1042 if (new_ti) {
1043 rcu_assign_pointer(table->ti, new_ti);
1044 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
1045 table->last_rehash = jiffies;
1046 }
1047}
1048
1049/* Must be called with OVS mutex held. */
1050static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow)
1051{
1052 struct table_instance *ti;
1053
1054 flow->ufid_table.hash = ufid_hash(&flow->id);
1055 ti = ovsl_dereference(table->ufid_ti);
1056 ufid_table_instance_insert(ti, flow);
1057 table->ufid_count++;
1058
1059 /* Expand table, if necessary, to make room. */
1060 if (table->ufid_count > ti->n_buckets) {
1061 struct table_instance *new_ti;
1062
1063 new_ti = table_instance_expand(ti, true);
1064 if (new_ti) {
1065 rcu_assign_pointer(table->ufid_ti, new_ti);
1066 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
1067 }
1068 }
1069}
1070
1071/* Must be called with OVS mutex held. */
1072int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
1073 const struct sw_flow_mask *mask)
1074{
1075 int err;
1076
1077 err = flow_mask_insert(table, flow, mask);
1078 if (err)
1079 return err;
1080 flow_key_insert(table, flow);
1081 if (ovs_identifier_is_ufid(&flow->id))
1082 flow_ufid_insert(table, flow);
1083
1084 return 0;
1085}
1086
1087static int compare_mask_and_count(const void *a, const void *b)
1088{
1089 const struct mask_count *mc_a = a;
1090 const struct mask_count *mc_b = b;
1091
1092 return (s64)mc_b->counter - (s64)mc_a->counter;
1093}
1094
1095/* Must be called with OVS mutex held. */
1096void ovs_flow_masks_rebalance(struct flow_table *table)
1097{
1098 struct mask_array *ma = rcu_dereference_ovsl(table->mask_array);
1099 struct mask_count *masks_and_count;
1100 struct mask_array *new;
1101 int masks_entries = 0;
1102 int i;
1103
1104 /* Build array of all current entries with use counters. */
1105 masks_and_count = kmalloc_array(ma->max, sizeof(*masks_and_count),
1106 GFP_KERNEL);
1107 if (!masks_and_count)
1108 return;
1109
1110 for (i = 0; i < ma->max; i++) {
1111 struct sw_flow_mask *mask;
1112 unsigned int start;
1113 int cpu;
1114
1115 mask = rcu_dereference_ovsl(ma->masks[i]);
1116 if (unlikely(!mask))
1117 break;
1118
1119 masks_and_count[i].index = i;
1120 masks_and_count[i].counter = 0;
1121
1122 for_each_possible_cpu(cpu) {
1123 u64 *usage_counters = per_cpu_ptr(ma->masks_usage_cntr,
1124 cpu);
1125 u64 counter;
1126
1127 do {
1128 start = u64_stats_fetch_begin_irq(&ma->syncp);
1129 counter = usage_counters[i];
1130 } while (u64_stats_fetch_retry_irq(&ma->syncp, start));
1131
1132 masks_and_count[i].counter += counter;
1133 }
1134
1135 /* Subtract the zero count value. */
1136 masks_and_count[i].counter -= ma->masks_usage_zero_cntr[i];
1137
1138 /* Rather than calling tbl_mask_array_reset_counters()
1139 * below when no change is needed, do it inline here.
1140 */
1141 ma->masks_usage_zero_cntr[i] += masks_and_count[i].counter;
1142 }
1143
1144 if (i == 0)
1145 goto free_mask_entries;
1146
1147 /* Sort the entries */
1148 masks_entries = i;
1149 sort(masks_and_count, masks_entries, sizeof(*masks_and_count),
1150 compare_mask_and_count, NULL);
1151
1152 /* If the order is the same, nothing to do... */
1153 for (i = 0; i < masks_entries; i++) {
1154 if (i != masks_and_count[i].index)
1155 break;
1156 }
1157 if (i == masks_entries)
1158 goto free_mask_entries;
1159
1160 /* Rebuilt the new list in order of usage. */
1161 new = tbl_mask_array_alloc(ma->max);
1162 if (!new)
1163 goto free_mask_entries;
1164
1165 for (i = 0; i < masks_entries; i++) {
1166 int index = masks_and_count[i].index;
1167
1168 if (ovsl_dereference(ma->masks[index]))
1169 new->masks[new->count++] = ma->masks[index];
1170 }
1171
1172 rcu_assign_pointer(table->mask_array, new);
1173 call_rcu(&ma->rcu, mask_array_rcu_cb);
1174
1175free_mask_entries:
1176 kfree(masks_and_count);
1177}
1178
1179/* Initializes the flow module.
1180 * Returns zero if successful or a negative error code. */
1181int ovs_flow_init(void)
1182{
1183 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
1184 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
1185
1186 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
1187 + (nr_cpu_ids
1188 * sizeof(struct sw_flow_stats *)),
1189 0, 0, NULL);
1190 if (flow_cache == NULL)
1191 return -ENOMEM;
1192
1193 flow_stats_cache
1194 = kmem_cache_create("sw_flow_stats", sizeof(struct sw_flow_stats),
1195 0, SLAB_HWCACHE_ALIGN, NULL);
1196 if (flow_stats_cache == NULL) {
1197 kmem_cache_destroy(flow_cache);
1198 flow_cache = NULL;
1199 return -ENOMEM;
1200 }
1201
1202 return 0;
1203}
1204
1205/* Uninitializes the flow module. */
1206void ovs_flow_exit(void)
1207{
1208 kmem_cache_destroy(flow_stats_cache);
1209 kmem_cache_destroy(flow_cache);
1210}