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19#include "flow.h"
20#include "datapath.h"
21#include <linux/uaccess.h>
22#include <linux/netdevice.h>
23#include <linux/etherdevice.h>
24#include <linux/if_ether.h>
25#include <linux/if_vlan.h>
26#include <net/llc_pdu.h>
27#include <linux/kernel.h>
28#include <linux/jhash.h>
29#include <linux/jiffies.h>
30#include <linux/llc.h>
31#include <linux/module.h>
32#include <linux/in.h>
33#include <linux/rcupdate.h>
34#include <linux/if_arp.h>
35#include <linux/ip.h>
36#include <linux/ipv6.h>
37#include <linux/sctp.h>
38#include <linux/tcp.h>
39#include <linux/udp.h>
40#include <linux/icmp.h>
41#include <linux/icmpv6.h>
42#include <linux/rculist.h>
43#include <net/ip.h>
44#include <net/ipv6.h>
45#include <net/ndisc.h>
46
47#define TBL_MIN_BUCKETS 1024
48#define REHASH_INTERVAL (10 * 60 * HZ)
49
50static struct kmem_cache *flow_cache;
51struct kmem_cache *flow_stats_cache __read_mostly;
52
53static u16 range_n_bytes(const struct sw_flow_key_range *range)
54{
55 return range->end - range->start;
56}
57
58void ovs_flow_mask_key(struct sw_flow_key *dst, const struct sw_flow_key *src,
59 const struct sw_flow_mask *mask)
60{
61 const long *m = (const long *)((const u8 *)&mask->key +
62 mask->range.start);
63 const long *s = (const long *)((const u8 *)src +
64 mask->range.start);
65 long *d = (long *)((u8 *)dst + mask->range.start);
66 int i;
67
68
69
70
71
72 for (i = 0; i < range_n_bytes(&mask->range); i += sizeof(long))
73 *d++ = *s++ & *m++;
74}
75
76struct sw_flow *ovs_flow_alloc(void)
77{
78 struct sw_flow *flow;
79 struct flow_stats *stats;
80 int node;
81
82 flow = kmem_cache_alloc(flow_cache, GFP_KERNEL);
83 if (!flow)
84 return ERR_PTR(-ENOMEM);
85
86 flow->sf_acts = NULL;
87 flow->mask = NULL;
88 flow->id.unmasked_key = NULL;
89 flow->id.ufid_len = 0;
90 flow->stats_last_writer = NUMA_NO_NODE;
91
92
93 stats = kmem_cache_alloc_node(flow_stats_cache,
94 GFP_KERNEL | __GFP_ZERO, 0);
95 if (!stats)
96 goto err;
97
98 spin_lock_init(&stats->lock);
99
100 RCU_INIT_POINTER(flow->stats[0], stats);
101
102 for_each_node(node)
103 if (node != 0)
104 RCU_INIT_POINTER(flow->stats[node], NULL);
105
106 return flow;
107err:
108 kmem_cache_free(flow_cache, flow);
109 return ERR_PTR(-ENOMEM);
110}
111
112int ovs_flow_tbl_count(const struct flow_table *table)
113{
114 return table->count;
115}
116
117static struct flex_array *alloc_buckets(unsigned int n_buckets)
118{
119 struct flex_array *buckets;
120 int i, err;
121
122 buckets = flex_array_alloc(sizeof(struct hlist_head),
123 n_buckets, GFP_KERNEL);
124 if (!buckets)
125 return NULL;
126
127 err = flex_array_prealloc(buckets, 0, n_buckets, GFP_KERNEL);
128 if (err) {
129 flex_array_free(buckets);
130 return NULL;
131 }
132
133 for (i = 0; i < n_buckets; i++)
134 INIT_HLIST_HEAD((struct hlist_head *)
135 flex_array_get(buckets, i));
136
137 return buckets;
138}
139
140static void flow_free(struct sw_flow *flow)
141{
142 int node;
143
144 if (ovs_identifier_is_key(&flow->id))
145 kfree(flow->id.unmasked_key);
146 kfree((struct sw_flow_actions __force *)flow->sf_acts);
147 for_each_node(node)
148 if (flow->stats[node])
149 kmem_cache_free(flow_stats_cache,
150 (struct flow_stats __force *)flow->stats[node]);
151 kmem_cache_free(flow_cache, flow);
152}
153
154static void rcu_free_flow_callback(struct rcu_head *rcu)
155{
156 struct sw_flow *flow = container_of(rcu, struct sw_flow, rcu);
157
158 flow_free(flow);
159}
160
161void ovs_flow_free(struct sw_flow *flow, bool deferred)
162{
163 if (!flow)
164 return;
165
166 if (deferred)
167 call_rcu(&flow->rcu, rcu_free_flow_callback);
168 else
169 flow_free(flow);
170}
171
172static void free_buckets(struct flex_array *buckets)
173{
174 flex_array_free(buckets);
175}
176
177
178static void __table_instance_destroy(struct table_instance *ti)
179{
180 free_buckets(ti->buckets);
181 kfree(ti);
182}
183
184static struct table_instance *table_instance_alloc(int new_size)
185{
186 struct table_instance *ti = kmalloc(sizeof(*ti), GFP_KERNEL);
187
188 if (!ti)
189 return NULL;
190
191 ti->buckets = alloc_buckets(new_size);
192
193 if (!ti->buckets) {
194 kfree(ti);
195 return NULL;
196 }
197 ti->n_buckets = new_size;
198 ti->node_ver = 0;
199 ti->keep_flows = false;
200 get_random_bytes(&ti->hash_seed, sizeof(u32));
201
202 return ti;
203}
204
205int ovs_flow_tbl_init(struct flow_table *table)
206{
207 struct table_instance *ti, *ufid_ti;
208
209 ti = table_instance_alloc(TBL_MIN_BUCKETS);
210
211 if (!ti)
212 return -ENOMEM;
213
214 ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
215 if (!ufid_ti)
216 goto free_ti;
217
218 rcu_assign_pointer(table->ti, ti);
219 rcu_assign_pointer(table->ufid_ti, ufid_ti);
220 INIT_LIST_HEAD(&table->mask_list);
221 table->last_rehash = jiffies;
222 table->count = 0;
223 table->ufid_count = 0;
224 return 0;
225
226free_ti:
227 __table_instance_destroy(ti);
228 return -ENOMEM;
229}
230
231static void flow_tbl_destroy_rcu_cb(struct rcu_head *rcu)
232{
233 struct table_instance *ti = container_of(rcu, struct table_instance, rcu);
234
235 __table_instance_destroy(ti);
236}
237
238static void table_instance_destroy(struct table_instance *ti,
239 struct table_instance *ufid_ti,
240 bool deferred)
241{
242 int i;
243
244 if (!ti)
245 return;
246
247 BUG_ON(!ufid_ti);
248 if (ti->keep_flows)
249 goto skip_flows;
250
251 for (i = 0; i < ti->n_buckets; i++) {
252 struct sw_flow *flow;
253 struct hlist_head *head = flex_array_get(ti->buckets, i);
254 struct hlist_node *n;
255 int ver = ti->node_ver;
256 int ufid_ver = ufid_ti->node_ver;
257
258 hlist_for_each_entry_safe(flow, n, head, flow_table.node[ver]) {
259 hlist_del_rcu(&flow->flow_table.node[ver]);
260 if (ovs_identifier_is_ufid(&flow->id))
261 hlist_del_rcu(&flow->ufid_table.node[ufid_ver]);
262 ovs_flow_free(flow, deferred);
263 }
264 }
265
266skip_flows:
267 if (deferred) {
268 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
269 call_rcu(&ufid_ti->rcu, flow_tbl_destroy_rcu_cb);
270 } else {
271 __table_instance_destroy(ti);
272 __table_instance_destroy(ufid_ti);
273 }
274}
275
276
277
278
279void ovs_flow_tbl_destroy(struct flow_table *table)
280{
281 struct table_instance *ti = rcu_dereference_raw(table->ti);
282 struct table_instance *ufid_ti = rcu_dereference_raw(table->ufid_ti);
283
284 table_instance_destroy(ti, ufid_ti, false);
285}
286
287struct sw_flow *ovs_flow_tbl_dump_next(struct table_instance *ti,
288 u32 *bucket, u32 *last)
289{
290 struct sw_flow *flow;
291 struct hlist_head *head;
292 int ver;
293 int i;
294
295 ver = ti->node_ver;
296 while (*bucket < ti->n_buckets) {
297 i = 0;
298 head = flex_array_get(ti->buckets, *bucket);
299 hlist_for_each_entry_rcu(flow, head, flow_table.node[ver]) {
300 if (i < *last) {
301 i++;
302 continue;
303 }
304 *last = i + 1;
305 return flow;
306 }
307 (*bucket)++;
308 *last = 0;
309 }
310
311 return NULL;
312}
313
314static struct hlist_head *find_bucket(struct table_instance *ti, u32 hash)
315{
316 hash = jhash_1word(hash, ti->hash_seed);
317 return flex_array_get(ti->buckets,
318 (hash & (ti->n_buckets - 1)));
319}
320
321static void table_instance_insert(struct table_instance *ti,
322 struct sw_flow *flow)
323{
324 struct hlist_head *head;
325
326 head = find_bucket(ti, flow->flow_table.hash);
327 hlist_add_head_rcu(&flow->flow_table.node[ti->node_ver], head);
328}
329
330static void ufid_table_instance_insert(struct table_instance *ti,
331 struct sw_flow *flow)
332{
333 struct hlist_head *head;
334
335 head = find_bucket(ti, flow->ufid_table.hash);
336 hlist_add_head_rcu(&flow->ufid_table.node[ti->node_ver], head);
337}
338
339static void flow_table_copy_flows(struct table_instance *old,
340 struct table_instance *new, bool ufid)
341{
342 int old_ver;
343 int i;
344
345 old_ver = old->node_ver;
346 new->node_ver = !old_ver;
347
348
349 for (i = 0; i < old->n_buckets; i++) {
350 struct sw_flow *flow;
351 struct hlist_head *head;
352
353 head = flex_array_get(old->buckets, i);
354
355 if (ufid)
356 hlist_for_each_entry(flow, head,
357 ufid_table.node[old_ver])
358 ufid_table_instance_insert(new, flow);
359 else
360 hlist_for_each_entry(flow, head,
361 flow_table.node[old_ver])
362 table_instance_insert(new, flow);
363 }
364
365 old->keep_flows = true;
366}
367
368static struct table_instance *table_instance_rehash(struct table_instance *ti,
369 int n_buckets, bool ufid)
370{
371 struct table_instance *new_ti;
372
373 new_ti = table_instance_alloc(n_buckets);
374 if (!new_ti)
375 return NULL;
376
377 flow_table_copy_flows(ti, new_ti, ufid);
378
379 return new_ti;
380}
381
382int ovs_flow_tbl_flush(struct flow_table *flow_table)
383{
384 struct table_instance *old_ti, *new_ti;
385 struct table_instance *old_ufid_ti, *new_ufid_ti;
386
387 new_ti = table_instance_alloc(TBL_MIN_BUCKETS);
388 if (!new_ti)
389 return -ENOMEM;
390 new_ufid_ti = table_instance_alloc(TBL_MIN_BUCKETS);
391 if (!new_ufid_ti)
392 goto err_free_ti;
393
394 old_ti = ovsl_dereference(flow_table->ti);
395 old_ufid_ti = ovsl_dereference(flow_table->ufid_ti);
396
397 rcu_assign_pointer(flow_table->ti, new_ti);
398 rcu_assign_pointer(flow_table->ufid_ti, new_ufid_ti);
399 flow_table->last_rehash = jiffies;
400 flow_table->count = 0;
401 flow_table->ufid_count = 0;
402
403 table_instance_destroy(old_ti, old_ufid_ti, true);
404 return 0;
405
406err_free_ti:
407 __table_instance_destroy(new_ti);
408 return -ENOMEM;
409}
410
411static u32 flow_hash(const struct sw_flow_key *key,
412 const struct sw_flow_key_range *range)
413{
414 int key_start = range->start;
415 int key_end = range->end;
416 const u32 *hash_key = (const u32 *)((const u8 *)key + key_start);
417 int hash_u32s = (key_end - key_start) >> 2;
418
419
420 BUILD_BUG_ON(sizeof(long) % sizeof(u32));
421
422 return jhash2(hash_key, hash_u32s, 0);
423}
424
425static int flow_key_start(const struct sw_flow_key *key)
426{
427 if (key->tun_key.ipv4_dst)
428 return 0;
429 else
430 return rounddown(offsetof(struct sw_flow_key, phy),
431 sizeof(long));
432}
433
434static bool cmp_key(const struct sw_flow_key *key1,
435 const struct sw_flow_key *key2,
436 int key_start, int key_end)
437{
438 const long *cp1 = (const long *)((const u8 *)key1 + key_start);
439 const long *cp2 = (const long *)((const u8 *)key2 + key_start);
440 long diffs = 0;
441 int i;
442
443 for (i = key_start; i < key_end; i += sizeof(long))
444 diffs |= *cp1++ ^ *cp2++;
445
446 return diffs == 0;
447}
448
449static bool flow_cmp_masked_key(const struct sw_flow *flow,
450 const struct sw_flow_key *key,
451 const struct sw_flow_key_range *range)
452{
453 return cmp_key(&flow->key, key, range->start, range->end);
454}
455
456static bool ovs_flow_cmp_unmasked_key(const struct sw_flow *flow,
457 const struct sw_flow_match *match)
458{
459 struct sw_flow_key *key = match->key;
460 int key_start = flow_key_start(key);
461 int key_end = match->range.end;
462
463 BUG_ON(ovs_identifier_is_ufid(&flow->id));
464 return cmp_key(flow->id.unmasked_key, key, key_start, key_end);
465}
466
467static struct sw_flow *masked_flow_lookup(struct table_instance *ti,
468 const struct sw_flow_key *unmasked,
469 const struct sw_flow_mask *mask)
470{
471 struct sw_flow *flow;
472 struct hlist_head *head;
473 u32 hash;
474 struct sw_flow_key masked_key;
475
476 ovs_flow_mask_key(&masked_key, unmasked, mask);
477 hash = flow_hash(&masked_key, &mask->range);
478 head = find_bucket(ti, hash);
479 hlist_for_each_entry_rcu(flow, head, flow_table.node[ti->node_ver]) {
480 if (flow->mask == mask && flow->flow_table.hash == hash &&
481 flow_cmp_masked_key(flow, &masked_key, &mask->range))
482 return flow;
483 }
484 return NULL;
485}
486
487struct sw_flow *ovs_flow_tbl_lookup_stats(struct flow_table *tbl,
488 const struct sw_flow_key *key,
489 u32 *n_mask_hit)
490{
491 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
492 struct sw_flow_mask *mask;
493 struct sw_flow *flow;
494
495 *n_mask_hit = 0;
496 list_for_each_entry_rcu(mask, &tbl->mask_list, list) {
497 (*n_mask_hit)++;
498 flow = masked_flow_lookup(ti, key, mask);
499 if (flow)
500 return flow;
501 }
502 return NULL;
503}
504
505struct sw_flow *ovs_flow_tbl_lookup(struct flow_table *tbl,
506 const struct sw_flow_key *key)
507{
508 u32 __always_unused n_mask_hit;
509
510 return ovs_flow_tbl_lookup_stats(tbl, key, &n_mask_hit);
511}
512
513struct sw_flow *ovs_flow_tbl_lookup_exact(struct flow_table *tbl,
514 const struct sw_flow_match *match)
515{
516 struct table_instance *ti = rcu_dereference_ovsl(tbl->ti);
517 struct sw_flow_mask *mask;
518 struct sw_flow *flow;
519
520
521 list_for_each_entry(mask, &tbl->mask_list, list) {
522 flow = masked_flow_lookup(ti, match->key, mask);
523 if (flow && ovs_identifier_is_key(&flow->id) &&
524 ovs_flow_cmp_unmasked_key(flow, match))
525 return flow;
526 }
527 return NULL;
528}
529
530static u32 ufid_hash(const struct sw_flow_id *sfid)
531{
532 return jhash(sfid->ufid, sfid->ufid_len, 0);
533}
534
535static bool ovs_flow_cmp_ufid(const struct sw_flow *flow,
536 const struct sw_flow_id *sfid)
537{
538 if (flow->id.ufid_len != sfid->ufid_len)
539 return false;
540
541 return !memcmp(flow->id.ufid, sfid->ufid, sfid->ufid_len);
542}
543
544bool ovs_flow_cmp(const struct sw_flow *flow, const struct sw_flow_match *match)
545{
546 if (ovs_identifier_is_ufid(&flow->id))
547 return flow_cmp_masked_key(flow, match->key, &match->range);
548
549 return ovs_flow_cmp_unmasked_key(flow, match);
550}
551
552struct sw_flow *ovs_flow_tbl_lookup_ufid(struct flow_table *tbl,
553 const struct sw_flow_id *ufid)
554{
555 struct table_instance *ti = rcu_dereference_ovsl(tbl->ufid_ti);
556 struct sw_flow *flow;
557 struct hlist_head *head;
558 u32 hash;
559
560 hash = ufid_hash(ufid);
561 head = find_bucket(ti, hash);
562 hlist_for_each_entry_rcu(flow, head, ufid_table.node[ti->node_ver]) {
563 if (flow->ufid_table.hash == hash &&
564 ovs_flow_cmp_ufid(flow, ufid))
565 return flow;
566 }
567 return NULL;
568}
569
570int ovs_flow_tbl_num_masks(const struct flow_table *table)
571{
572 struct sw_flow_mask *mask;
573 int num = 0;
574
575 list_for_each_entry(mask, &table->mask_list, list)
576 num++;
577
578 return num;
579}
580
581static struct table_instance *table_instance_expand(struct table_instance *ti,
582 bool ufid)
583{
584 return table_instance_rehash(ti, ti->n_buckets * 2, ufid);
585}
586
587
588static void flow_mask_remove(struct flow_table *tbl, struct sw_flow_mask *mask)
589{
590 if (mask) {
591
592
593
594 ASSERT_OVSL();
595 BUG_ON(!mask->ref_count);
596 mask->ref_count--;
597
598 if (!mask->ref_count) {
599 list_del_rcu(&mask->list);
600 kfree_rcu(mask, rcu);
601 }
602 }
603}
604
605
606void ovs_flow_tbl_remove(struct flow_table *table, struct sw_flow *flow)
607{
608 struct table_instance *ti = ovsl_dereference(table->ti);
609 struct table_instance *ufid_ti = ovsl_dereference(table->ufid_ti);
610
611 BUG_ON(table->count == 0);
612 hlist_del_rcu(&flow->flow_table.node[ti->node_ver]);
613 table->count--;
614 if (ovs_identifier_is_ufid(&flow->id)) {
615 hlist_del_rcu(&flow->ufid_table.node[ufid_ti->node_ver]);
616 table->ufid_count--;
617 }
618
619
620
621
622 flow_mask_remove(table, flow->mask);
623}
624
625static struct sw_flow_mask *mask_alloc(void)
626{
627 struct sw_flow_mask *mask;
628
629 mask = kmalloc(sizeof(*mask), GFP_KERNEL);
630 if (mask)
631 mask->ref_count = 1;
632
633 return mask;
634}
635
636static bool mask_equal(const struct sw_flow_mask *a,
637 const struct sw_flow_mask *b)
638{
639 const u8 *a_ = (const u8 *)&a->key + a->range.start;
640 const u8 *b_ = (const u8 *)&b->key + b->range.start;
641
642 return (a->range.end == b->range.end)
643 && (a->range.start == b->range.start)
644 && (memcmp(a_, b_, range_n_bytes(&a->range)) == 0);
645}
646
647static struct sw_flow_mask *flow_mask_find(const struct flow_table *tbl,
648 const struct sw_flow_mask *mask)
649{
650 struct list_head *ml;
651
652 list_for_each(ml, &tbl->mask_list) {
653 struct sw_flow_mask *m;
654 m = container_of(ml, struct sw_flow_mask, list);
655 if (mask_equal(mask, m))
656 return m;
657 }
658
659 return NULL;
660}
661
662
663static int flow_mask_insert(struct flow_table *tbl, struct sw_flow *flow,
664 const struct sw_flow_mask *new)
665{
666 struct sw_flow_mask *mask;
667 mask = flow_mask_find(tbl, new);
668 if (!mask) {
669
670 mask = mask_alloc();
671 if (!mask)
672 return -ENOMEM;
673 mask->key = new->key;
674 mask->range = new->range;
675 list_add_rcu(&mask->list, &tbl->mask_list);
676 } else {
677 BUG_ON(!mask->ref_count);
678 mask->ref_count++;
679 }
680
681 flow->mask = mask;
682 return 0;
683}
684
685
686static void flow_key_insert(struct flow_table *table, struct sw_flow *flow)
687{
688 struct table_instance *new_ti = NULL;
689 struct table_instance *ti;
690
691 flow->flow_table.hash = flow_hash(&flow->key, &flow->mask->range);
692 ti = ovsl_dereference(table->ti);
693 table_instance_insert(ti, flow);
694 table->count++;
695
696
697 if (table->count > ti->n_buckets)
698 new_ti = table_instance_expand(ti, false);
699 else if (time_after(jiffies, table->last_rehash + REHASH_INTERVAL))
700 new_ti = table_instance_rehash(ti, ti->n_buckets, false);
701
702 if (new_ti) {
703 rcu_assign_pointer(table->ti, new_ti);
704 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
705 table->last_rehash = jiffies;
706 }
707}
708
709
710static void flow_ufid_insert(struct flow_table *table, struct sw_flow *flow)
711{
712 struct table_instance *ti;
713
714 flow->ufid_table.hash = ufid_hash(&flow->id);
715 ti = ovsl_dereference(table->ufid_ti);
716 ufid_table_instance_insert(ti, flow);
717 table->ufid_count++;
718
719
720 if (table->ufid_count > ti->n_buckets) {
721 struct table_instance *new_ti;
722
723 new_ti = table_instance_expand(ti, true);
724 if (new_ti) {
725 rcu_assign_pointer(table->ufid_ti, new_ti);
726 call_rcu(&ti->rcu, flow_tbl_destroy_rcu_cb);
727 }
728 }
729}
730
731
732int ovs_flow_tbl_insert(struct flow_table *table, struct sw_flow *flow,
733 const struct sw_flow_mask *mask)
734{
735 int err;
736
737 err = flow_mask_insert(table, flow, mask);
738 if (err)
739 return err;
740 flow_key_insert(table, flow);
741 if (ovs_identifier_is_ufid(&flow->id))
742 flow_ufid_insert(table, flow);
743
744 return 0;
745}
746
747
748
749int ovs_flow_init(void)
750{
751 BUILD_BUG_ON(__alignof__(struct sw_flow_key) % __alignof__(long));
752 BUILD_BUG_ON(sizeof(struct sw_flow_key) % sizeof(long));
753
754 flow_cache = kmem_cache_create("sw_flow", sizeof(struct sw_flow)
755 + (num_possible_nodes()
756 * sizeof(struct flow_stats *)),
757 0, 0, NULL);
758 if (flow_cache == NULL)
759 return -ENOMEM;
760
761 flow_stats_cache
762 = kmem_cache_create("sw_flow_stats", sizeof(struct flow_stats),
763 0, SLAB_HWCACHE_ALIGN, NULL);
764 if (flow_stats_cache == NULL) {
765 kmem_cache_destroy(flow_cache);
766 flow_cache = NULL;
767 return -ENOMEM;
768 }
769
770 return 0;
771}
772
773
774void ovs_flow_exit(void)
775{
776 kmem_cache_destroy(flow_stats_cache);
777 kmem_cache_destroy(flow_cache);
778}
779