summaryrefslogtreecommitdiff
path: root/net/netfilter/nf_flow_table_offload.c
blob: d06969af1085e571fadd5940c028b64685b9f6c9 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netfilter.h>
#include <linux/rhashtable.h>
#include <linux/netdevice.h>
#include <linux/tc_act/tc_csum.h>
#include <net/flow_offload.h>
#include <net/netfilter/nf_flow_table.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_tuple.h>

static struct work_struct nf_flow_offload_work;
static DEFINE_SPINLOCK(flow_offload_pending_list_lock);
static LIST_HEAD(flow_offload_pending_list);

struct flow_offload_work {
	struct list_head	list;
	enum flow_cls_command	cmd;
	int			priority;
	struct nf_flowtable	*flowtable;
	struct flow_offload	*flow;
};

struct nf_flow_key {
	struct flow_dissector_key_control		control;
	struct flow_dissector_key_basic			basic;
	union {
		struct flow_dissector_key_ipv4_addrs	ipv4;
		struct flow_dissector_key_ipv6_addrs	ipv6;
	};
	struct flow_dissector_key_tcp			tcp;
	struct flow_dissector_key_ports			tp;
} __aligned(BITS_PER_LONG / 8); /* Ensure that we can do comparisons as longs. */

struct nf_flow_match {
	struct flow_dissector	dissector;
	struct nf_flow_key	key;
	struct nf_flow_key	mask;
};

struct nf_flow_rule {
	struct nf_flow_match	match;
	struct flow_rule	*rule;
};

#define NF_FLOW_DISSECTOR(__match, __type, __field)	\
	(__match)->dissector.offset[__type] =		\
		offsetof(struct nf_flow_key, __field)

static int nf_flow_rule_match(struct nf_flow_match *match,
			      const struct flow_offload_tuple *tuple)
{
	struct nf_flow_key *mask = &match->mask;
	struct nf_flow_key *key = &match->key;

	NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_CONTROL, control);
	NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_BASIC, basic);
	NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_IPV4_ADDRS, ipv4);
	NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_IPV6_ADDRS, ipv6);
	NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_TCP, tcp);
	NF_FLOW_DISSECTOR(match, FLOW_DISSECTOR_KEY_PORTS, tp);

	switch (tuple->l3proto) {
	case AF_INET:
		key->control.addr_type = FLOW_DISSECTOR_KEY_IPV4_ADDRS;
		key->basic.n_proto = htons(ETH_P_IP);
		key->ipv4.src = tuple->src_v4.s_addr;
		mask->ipv4.src = 0xffffffff;
		key->ipv4.dst = tuple->dst_v4.s_addr;
		mask->ipv4.dst = 0xffffffff;
		break;
       case AF_INET6:
		key->control.addr_type = FLOW_DISSECTOR_KEY_IPV6_ADDRS;
		key->basic.n_proto = htons(ETH_P_IPV6);
		key->ipv6.src = tuple->src_v6;
		memset(&mask->ipv6.src, 0xff, sizeof(mask->ipv6.src));
		key->ipv6.dst = tuple->dst_v6;
		memset(&mask->ipv6.dst, 0xff, sizeof(mask->ipv6.dst));
		break;
	default:
		return -EOPNOTSUPP;
	}
	match->dissector.used_keys |= BIT(key->control.addr_type);
	mask->basic.n_proto = 0xffff;

	switch (tuple->l4proto) {
	case IPPROTO_TCP:
		key->tcp.flags = 0;
		mask->tcp.flags = cpu_to_be16(be32_to_cpu(TCP_FLAG_RST | TCP_FLAG_FIN) >> 16);
		match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_TCP);
		break;
	case IPPROTO_UDP:
		break;
	default:
		return -EOPNOTSUPP;
	}

	key->basic.ip_proto = tuple->l4proto;
	mask->basic.ip_proto = 0xff;

	key->tp.src = tuple->src_port;
	mask->tp.src = 0xffff;
	key->tp.dst = tuple->dst_port;
	mask->tp.dst = 0xffff;

	match->dissector.used_keys |= BIT(FLOW_DISSECTOR_KEY_CONTROL) |
				      BIT(FLOW_DISSECTOR_KEY_BASIC) |
				      BIT(FLOW_DISSECTOR_KEY_PORTS);
	return 0;
}

static void flow_offload_mangle(struct flow_action_entry *entry,
				enum flow_action_mangle_base htype, u32 offset,
				const __be32 *value, const __be32 *mask)
{
	entry->id = FLOW_ACTION_MANGLE;
	entry->mangle.htype = htype;
	entry->mangle.offset = offset;
	memcpy(&entry->mangle.mask, mask, sizeof(u32));
	memcpy(&entry->mangle.val, value, sizeof(u32));
}

static inline struct flow_action_entry *
flow_action_entry_next(struct nf_flow_rule *flow_rule)
{
	int i = flow_rule->rule->action.num_entries++;

	return &flow_rule->rule->action.entries[i];
}

static int flow_offload_eth_src(struct net *net,
				const struct flow_offload *flow,
				enum flow_offload_tuple_dir dir,
				struct nf_flow_rule *flow_rule)
{
	const struct flow_offload_tuple *tuple = &flow->tuplehash[!dir].tuple;
	struct flow_action_entry *entry0 = flow_action_entry_next(flow_rule);
	struct flow_action_entry *entry1 = flow_action_entry_next(flow_rule);
	struct net_device *dev;
	u32 mask, val;
	u16 val16;

	dev = dev_get_by_index(net, tuple->iifidx);
	if (!dev)
		return -ENOENT;

	mask = ~0xffff0000;
	memcpy(&val16, dev->dev_addr, 2);
	val = val16 << 16;
	flow_offload_mangle(entry0, FLOW_ACT_MANGLE_HDR_TYPE_ETH, 4,
			    &val, &mask);

	mask = ~0xffffffff;
	memcpy(&val, dev->dev_addr + 2, 4);
	flow_offload_mangle(entry1, FLOW_ACT_MANGLE_HDR_TYPE_ETH, 8,
			    &val, &mask);
	dev_put(dev);

	return 0;
}

static int flow_offload_eth_dst(struct net *net,
				const struct flow_offload *flow,
				enum flow_offload_tuple_dir dir,
				struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry0 = flow_action_entry_next(flow_rule);
	struct flow_action_entry *entry1 = flow_action_entry_next(flow_rule);
	const void *daddr = &flow->tuplehash[!dir].tuple.src_v4;
	const struct dst_entry *dst_cache;
	unsigned char ha[ETH_ALEN];
	struct neighbour *n;
	u32 mask, val;
	u8 nud_state;
	u16 val16;

	dst_cache = flow->tuplehash[dir].tuple.dst_cache;
	n = dst_neigh_lookup(dst_cache, daddr);
	if (!n)
		return -ENOENT;

	read_lock_bh(&n->lock);
	nud_state = n->nud_state;
	ether_addr_copy(ha, n->ha);
	read_unlock_bh(&n->lock);

	if (!(nud_state & NUD_VALID)) {
		neigh_release(n);
		return -ENOENT;
	}

	mask = ~0xffffffff;
	memcpy(&val, ha, 4);
	flow_offload_mangle(entry0, FLOW_ACT_MANGLE_HDR_TYPE_ETH, 0,
			    &val, &mask);

	mask = ~0x0000ffff;
	memcpy(&val16, ha + 4, 2);
	val = val16;
	flow_offload_mangle(entry1, FLOW_ACT_MANGLE_HDR_TYPE_ETH, 4,
			    &val, &mask);
	neigh_release(n);

	return 0;
}

static void flow_offload_ipv4_snat(struct net *net,
				   const struct flow_offload *flow,
				   enum flow_offload_tuple_dir dir,
				   struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry = flow_action_entry_next(flow_rule);
	u32 mask = ~htonl(0xffffffff);
	__be32 addr;
	u32 offset;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v4.s_addr;
		offset = offsetof(struct iphdr, saddr);
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v4.s_addr;
		offset = offsetof(struct iphdr, daddr);
		break;
	default:
		return;
	}

	flow_offload_mangle(entry, FLOW_ACT_MANGLE_HDR_TYPE_IP4, offset,
			    &addr, &mask);
}

static void flow_offload_ipv4_dnat(struct net *net,
				   const struct flow_offload *flow,
				   enum flow_offload_tuple_dir dir,
				   struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry = flow_action_entry_next(flow_rule);
	u32 mask = ~htonl(0xffffffff);
	__be32 addr;
	u32 offset;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v4.s_addr;
		offset = offsetof(struct iphdr, daddr);
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v4.s_addr;
		offset = offsetof(struct iphdr, saddr);
		break;
	default:
		return;
	}

	flow_offload_mangle(entry, FLOW_ACT_MANGLE_HDR_TYPE_IP4, offset,
			    &addr, &mask);
}

static void flow_offload_ipv6_mangle(struct nf_flow_rule *flow_rule,
				     unsigned int offset,
				     const __be32 *addr, const __be32 *mask)
{
	struct flow_action_entry *entry;
	int i;

	for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i += sizeof(u32)) {
		entry = flow_action_entry_next(flow_rule);
		flow_offload_mangle(entry, FLOW_ACT_MANGLE_HDR_TYPE_IP6,
				    offset + i, &addr[i], mask);
	}
}

static void flow_offload_ipv6_snat(struct net *net,
				   const struct flow_offload *flow,
				   enum flow_offload_tuple_dir dir,
				   struct nf_flow_rule *flow_rule)
{
	u32 mask = ~htonl(0xffffffff);
	const __be32 *addr;
	u32 offset;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_v6.s6_addr32;
		offset = offsetof(struct ipv6hdr, saddr);
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_v6.s6_addr32;
		offset = offsetof(struct ipv6hdr, daddr);
		break;
	default:
		return;
	}

	flow_offload_ipv6_mangle(flow_rule, offset, addr, &mask);
}

static void flow_offload_ipv6_dnat(struct net *net,
				   const struct flow_offload *flow,
				   enum flow_offload_tuple_dir dir,
				   struct nf_flow_rule *flow_rule)
{
	u32 mask = ~htonl(0xffffffff);
	const __be32 *addr;
	u32 offset;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_v6.s6_addr32;
		offset = offsetof(struct ipv6hdr, daddr);
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		addr = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_v6.s6_addr32;
		offset = offsetof(struct ipv6hdr, saddr);
		break;
	default:
		return;
	}

	flow_offload_ipv6_mangle(flow_rule, offset, addr, &mask);
}

static int flow_offload_l4proto(const struct flow_offload *flow)
{
	u8 protonum = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l4proto;
	u8 type = 0;

	switch (protonum) {
	case IPPROTO_TCP:
		type = FLOW_ACT_MANGLE_HDR_TYPE_TCP;
		break;
	case IPPROTO_UDP:
		type = FLOW_ACT_MANGLE_HDR_TYPE_UDP;
		break;
	default:
		break;
	}

	return type;
}

static void flow_offload_port_snat(struct net *net,
				   const struct flow_offload *flow,
				   enum flow_offload_tuple_dir dir,
				   struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry = flow_action_entry_next(flow_rule);
	u32 mask, port;
	u32 offset;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		port = ntohs(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.dst_port);
		offset = 0; /* offsetof(struct tcphdr, source); */
		port = htonl(port << 16);
		mask = ~htonl(0xffff0000);
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		port = ntohs(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.src_port);
		offset = 0; /* offsetof(struct tcphdr, dest); */
		port = htonl(port);
		mask = ~htonl(0xffff);
		break;
	default:
		return;
	}

	flow_offload_mangle(entry, flow_offload_l4proto(flow), offset,
			    &port, &mask);
}

static void flow_offload_port_dnat(struct net *net,
				   const struct flow_offload *flow,
				   enum flow_offload_tuple_dir dir,
				   struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry = flow_action_entry_next(flow_rule);
	u32 mask, port;
	u32 offset;

	switch (dir) {
	case FLOW_OFFLOAD_DIR_ORIGINAL:
		port = ntohs(flow->tuplehash[FLOW_OFFLOAD_DIR_REPLY].tuple.src_port);
		offset = 0; /* offsetof(struct tcphdr, dest); */
		port = htonl(port);
		mask = ~htonl(0xffff);
		break;
	case FLOW_OFFLOAD_DIR_REPLY:
		port = ntohs(flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.dst_port);
		offset = 0; /* offsetof(struct tcphdr, source); */
		port = htonl(port << 16);
		mask = ~htonl(0xffff0000);
		break;
	default:
		return;
	}

	flow_offload_mangle(entry, flow_offload_l4proto(flow), offset,
			    &port, &mask);
}

static void flow_offload_ipv4_checksum(struct net *net,
				       const struct flow_offload *flow,
				       struct nf_flow_rule *flow_rule)
{
	u8 protonum = flow->tuplehash[FLOW_OFFLOAD_DIR_ORIGINAL].tuple.l4proto;
	struct flow_action_entry *entry = flow_action_entry_next(flow_rule);

	entry->id = FLOW_ACTION_CSUM;
	entry->csum_flags = TCA_CSUM_UPDATE_FLAG_IPV4HDR;

	switch (protonum) {
	case IPPROTO_TCP:
		entry->csum_flags |= TCA_CSUM_UPDATE_FLAG_TCP;
		break;
	case IPPROTO_UDP:
		entry->csum_flags |= TCA_CSUM_UPDATE_FLAG_UDP;
		break;
	}
}

static void flow_offload_redirect(const struct flow_offload *flow,
				  enum flow_offload_tuple_dir dir,
				  struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry = flow_action_entry_next(flow_rule);
	struct rtable *rt;

	rt = (struct rtable *)flow->tuplehash[dir].tuple.dst_cache;
	entry->id = FLOW_ACTION_REDIRECT;
	entry->dev = rt->dst.dev;
	dev_hold(rt->dst.dev);
}

int nf_flow_rule_route_ipv4(struct net *net, const struct flow_offload *flow,
			    enum flow_offload_tuple_dir dir,
			    struct nf_flow_rule *flow_rule)
{
	if (flow_offload_eth_src(net, flow, dir, flow_rule) < 0 ||
	    flow_offload_eth_dst(net, flow, dir, flow_rule) < 0)
		return -1;

	if (flow->flags & FLOW_OFFLOAD_SNAT) {
		flow_offload_ipv4_snat(net, flow, dir, flow_rule);
		flow_offload_port_snat(net, flow, dir, flow_rule);
	}
	if (flow->flags & FLOW_OFFLOAD_DNAT) {
		flow_offload_ipv4_dnat(net, flow, dir, flow_rule);
		flow_offload_port_dnat(net, flow, dir, flow_rule);
	}
	if (flow->flags & FLOW_OFFLOAD_SNAT ||
	    flow->flags & FLOW_OFFLOAD_DNAT)
		flow_offload_ipv4_checksum(net, flow, flow_rule);

	flow_offload_redirect(flow, dir, flow_rule);

	return 0;
}
EXPORT_SYMBOL_GPL(nf_flow_rule_route_ipv4);

int nf_flow_rule_route_ipv6(struct net *net, const struct flow_offload *flow,
			    enum flow_offload_tuple_dir dir,
			    struct nf_flow_rule *flow_rule)
{
	if (flow_offload_eth_src(net, flow, dir, flow_rule) < 0 ||
	    flow_offload_eth_dst(net, flow, dir, flow_rule) < 0)
		return -1;

	if (flow->flags & FLOW_OFFLOAD_SNAT) {
		flow_offload_ipv6_snat(net, flow, dir, flow_rule);
		flow_offload_port_snat(net, flow, dir, flow_rule);
	}
	if (flow->flags & FLOW_OFFLOAD_DNAT) {
		flow_offload_ipv6_dnat(net, flow, dir, flow_rule);
		flow_offload_port_dnat(net, flow, dir, flow_rule);
	}

	flow_offload_redirect(flow, dir, flow_rule);

	return 0;
}
EXPORT_SYMBOL_GPL(nf_flow_rule_route_ipv6);

#define NF_FLOW_RULE_ACTION_MAX	16

static struct nf_flow_rule *
nf_flow_offload_rule_alloc(struct net *net,
			   const struct flow_offload_work *offload,
			   enum flow_offload_tuple_dir dir)
{
	const struct nf_flowtable *flowtable = offload->flowtable;
	const struct flow_offload *flow = offload->flow;
	const struct flow_offload_tuple *tuple;
	struct nf_flow_rule *flow_rule;
	int err = -ENOMEM;

	flow_rule = kzalloc(sizeof(*flow_rule), GFP_KERNEL);
	if (!flow_rule)
		goto err_flow;

	flow_rule->rule = flow_rule_alloc(NF_FLOW_RULE_ACTION_MAX);
	if (!flow_rule->rule)
		goto err_flow_rule;

	flow_rule->rule->match.dissector = &flow_rule->match.dissector;
	flow_rule->rule->match.mask = &flow_rule->match.mask;
	flow_rule->rule->match.key = &flow_rule->match.key;

	tuple = &flow->tuplehash[dir].tuple;
	err = nf_flow_rule_match(&flow_rule->match, tuple);
	if (err < 0)
		goto err_flow_match;

	flow_rule->rule->action.num_entries = 0;
	if (flowtable->type->action(net, flow, dir, flow_rule) < 0)
		goto err_flow_match;

	return flow_rule;

err_flow_match:
	kfree(flow_rule->rule);
err_flow_rule:
	kfree(flow_rule);
err_flow:
	return NULL;
}

static void __nf_flow_offload_destroy(struct nf_flow_rule *flow_rule)
{
	struct flow_action_entry *entry;
	int i;

	for (i = 0; i < flow_rule->rule->action.num_entries; i++) {
		entry = &flow_rule->rule->action.entries[i];
		if (entry->id != FLOW_ACTION_REDIRECT)
			continue;

		dev_put(entry->dev);
	}
	kfree(flow_rule->rule);
	kfree(flow_rule);
}

static void nf_flow_offload_destroy(struct nf_flow_rule *flow_rule[])
{
	int i;

	for (i = 0; i < FLOW_OFFLOAD_DIR_MAX; i++)
		__nf_flow_offload_destroy(flow_rule[i]);
}

static int nf_flow_offload_alloc(const struct flow_offload_work *offload,
				 struct nf_flow_rule *flow_rule[])
{
	struct net *net = read_pnet(&offload->flowtable->net);

	flow_rule[0] = nf_flow_offload_rule_alloc(net, offload,
						  FLOW_OFFLOAD_DIR_ORIGINAL);
	if (!flow_rule[0])
		return -ENOMEM;

	flow_rule[1] = nf_flow_offload_rule_alloc(net, offload,
						  FLOW_OFFLOAD_DIR_REPLY);
	if (!flow_rule[1]) {
		__nf_flow_offload_destroy(flow_rule[0]);
		return -ENOMEM;
	}

	return 0;
}

static void nf_flow_offload_init(struct flow_cls_offload *cls_flow,
				 __be16 proto, int priority,
				 enum flow_cls_command cmd,
				 const struct flow_offload_tuple *tuple,
				 struct netlink_ext_ack *extack)
{
	cls_flow->common.protocol = proto;
	cls_flow->common.prio = priority;
	cls_flow->common.extack = extack;
	cls_flow->command = cmd;
	cls_flow->cookie = (unsigned long)tuple;
}

static int flow_offload_tuple_add(struct flow_offload_work *offload,
				  struct nf_flow_rule *flow_rule,
				  enum flow_offload_tuple_dir dir)
{
	struct nf_flowtable *flowtable = offload->flowtable;
	struct flow_cls_offload cls_flow = {};
	struct flow_block_cb *block_cb;
	struct netlink_ext_ack extack;
	__be16 proto = ETH_P_ALL;
	int err, i = 0;

	nf_flow_offload_init(&cls_flow, proto, offload->priority,
			     FLOW_CLS_REPLACE,
			     &offload->flow->tuplehash[dir].tuple, &extack);
	cls_flow.rule = flow_rule->rule;

	list_for_each_entry(block_cb, &flowtable->flow_block.cb_list, list) {
		err = block_cb->cb(TC_SETUP_CLSFLOWER, &cls_flow,
				   block_cb->cb_priv);
		if (err < 0)
			continue;

		i++;
	}

	return i;
}

static void flow_offload_tuple_del(struct flow_offload_work *offload,
				   enum flow_offload_tuple_dir dir)
{
	struct nf_flowtable *flowtable = offload->flowtable;
	struct flow_cls_offload cls_flow = {};
	struct flow_block_cb *block_cb;
	struct netlink_ext_ack extack;
	__be16 proto = ETH_P_ALL;

	nf_flow_offload_init(&cls_flow, proto, offload->priority,
			     FLOW_CLS_DESTROY,
			     &offload->flow->tuplehash[dir].tuple, &extack);

	list_for_each_entry(block_cb, &flowtable->flow_block.cb_list, list)
		block_cb->cb(TC_SETUP_CLSFLOWER, &cls_flow, block_cb->cb_priv);

	offload->flow->flags |= FLOW_OFFLOAD_HW_DEAD;
}

static int flow_offload_rule_add(struct flow_offload_work *offload,
				 struct nf_flow_rule *flow_rule[])
{
	int ok_count = 0;

	ok_count += flow_offload_tuple_add(offload, flow_rule[0],
					   FLOW_OFFLOAD_DIR_ORIGINAL);
	ok_count += flow_offload_tuple_add(offload, flow_rule[1],
					   FLOW_OFFLOAD_DIR_REPLY);
	if (ok_count == 0)
		return -ENOENT;

	return 0;
}

static int flow_offload_work_add(struct flow_offload_work *offload)
{
	struct nf_flow_rule *flow_rule[FLOW_OFFLOAD_DIR_MAX];
	int err;

	err = nf_flow_offload_alloc(offload, flow_rule);
	if (err < 0)
		return -ENOMEM;

	err = flow_offload_rule_add(offload, flow_rule);

	nf_flow_offload_destroy(flow_rule);

	return err;
}

static void flow_offload_work_del(struct flow_offload_work *offload)
{
	flow_offload_tuple_del(offload, FLOW_OFFLOAD_DIR_ORIGINAL);
	flow_offload_tuple_del(offload, FLOW_OFFLOAD_DIR_REPLY);
}

static void flow_offload_tuple_stats(struct flow_offload_work *offload,
				     enum flow_offload_tuple_dir dir,
				     struct flow_stats *stats)
{
	struct nf_flowtable *flowtable = offload->flowtable;
	struct flow_cls_offload cls_flow = {};
	struct flow_block_cb *block_cb;
	struct netlink_ext_ack extack;
	__be16 proto = ETH_P_ALL;

	nf_flow_offload_init(&cls_flow, proto, offload->priority,
			     FLOW_CLS_STATS,
			     &offload->flow->tuplehash[dir].tuple, &extack);

	list_for_each_entry(block_cb, &flowtable->flow_block.cb_list, list)
		block_cb->cb(TC_SETUP_CLSFLOWER, &cls_flow, block_cb->cb_priv);
	memcpy(stats, &cls_flow.stats, sizeof(*stats));
}

static void flow_offload_work_stats(struct flow_offload_work *offload)
{
	struct flow_stats stats[FLOW_OFFLOAD_DIR_MAX] = {};
	u64 lastused;

	flow_offload_tuple_stats(offload, FLOW_OFFLOAD_DIR_ORIGINAL, &stats[0]);
	flow_offload_tuple_stats(offload, FLOW_OFFLOAD_DIR_REPLY, &stats[1]);

	lastused = max_t(u64, stats[0].lastused, stats[1].lastused);
	offload->flow->timeout = max_t(u64, offload->flow->timeout,
				       lastused + NF_FLOW_TIMEOUT);
}

static void flow_offload_work_handler(struct work_struct *work)
{
	struct flow_offload_work *offload, *next;
	LIST_HEAD(offload_pending_list);
	int ret;

	spin_lock_bh(&flow_offload_pending_list_lock);
	list_replace_init(&flow_offload_pending_list, &offload_pending_list);
	spin_unlock_bh(&flow_offload_pending_list_lock);

	list_for_each_entry_safe(offload, next, &offload_pending_list, list) {
		switch (offload->cmd) {
		case FLOW_CLS_REPLACE:
			ret = flow_offload_work_add(offload);
			if (ret < 0)
				offload->flow->flags &= ~FLOW_OFFLOAD_HW;
			break;
		case FLOW_CLS_DESTROY:
			flow_offload_work_del(offload);
			break;
		case FLOW_CLS_STATS:
			flow_offload_work_stats(offload);
			break;
		default:
			WARN_ON_ONCE(1);
		}
		list_del(&offload->list);
		kfree(offload);
	}
}

static void flow_offload_queue_work(struct flow_offload_work *offload)
{
	spin_lock_bh(&flow_offload_pending_list_lock);
	list_add_tail(&offload->list, &flow_offload_pending_list);
	spin_unlock_bh(&flow_offload_pending_list_lock);

	schedule_work(&nf_flow_offload_work);
}

void nf_flow_offload_add(struct nf_flowtable *flowtable,
			 struct flow_offload *flow)
{
	struct flow_offload_work *offload;

	offload = kmalloc(sizeof(struct flow_offload_work), GFP_ATOMIC);
	if (!offload)
		return;

	offload->cmd = FLOW_CLS_REPLACE;
	offload->flow = flow;
	offload->priority = flowtable->priority;
	offload->flowtable = flowtable;
	flow->flags |= FLOW_OFFLOAD_HW;

	flow_offload_queue_work(offload);
}

void nf_flow_offload_del(struct nf_flowtable *flowtable,
			 struct flow_offload *flow)
{
	struct flow_offload_work *offload;

	offload = kzalloc(sizeof(struct flow_offload_work), GFP_ATOMIC);
	if (!offload)
		return;

	offload->cmd = FLOW_CLS_DESTROY;
	offload->flow = flow;
	offload->flow->flags |= FLOW_OFFLOAD_HW_DYING;
	offload->flowtable = flowtable;

	flow_offload_queue_work(offload);
}

void nf_flow_offload_stats(struct nf_flowtable *flowtable,
			   struct flow_offload *flow)
{
	struct flow_offload_work *offload;
	__s32 delta;

	delta = nf_flow_timeout_delta(flow->timeout);
	if ((delta >= (9 * NF_FLOW_TIMEOUT) / 10) ||
	    flow->flags & FLOW_OFFLOAD_HW_DYING)
		return;

	offload = kzalloc(sizeof(struct flow_offload_work), GFP_ATOMIC);
	if (!offload)
		return;

	offload->cmd = FLOW_CLS_STATS;
	offload->flow = flow;
	offload->flowtable = flowtable;

	flow_offload_queue_work(offload);
}

void nf_flow_table_offload_flush(struct nf_flowtable *flowtable)
{
	if (flowtable->flags & NF_FLOWTABLE_HW_OFFLOAD)
		flush_work(&nf_flow_offload_work);
}

static int nf_flow_table_block_setup(struct nf_flowtable *flowtable,
				     struct flow_block_offload *bo,
				     enum flow_block_command cmd)
{
	struct flow_block_cb *block_cb, *next;
	int err = 0;

	switch (cmd) {
	case FLOW_BLOCK_BIND:
		list_splice(&bo->cb_list, &flowtable->flow_block.cb_list);
		break;
	case FLOW_BLOCK_UNBIND:
		list_for_each_entry_safe(block_cb, next, &bo->cb_list, list) {
			list_del(&block_cb->list);
			flow_block_cb_free(block_cb);
		}
		break;
	default:
		WARN_ON_ONCE(1);
		err = -EOPNOTSUPP;
	}

	return err;
}

int nf_flow_table_offload_setup(struct nf_flowtable *flowtable,
				struct net_device *dev,
				enum flow_block_command cmd)
{
	struct netlink_ext_ack extack = {};
	struct flow_block_offload bo = {};
	int err;

	if (!(flowtable->flags & NF_FLOWTABLE_HW_OFFLOAD))
		return 0;

	if (!dev->netdev_ops->ndo_setup_tc)
		return -EOPNOTSUPP;

	bo.net		= dev_net(dev);
	bo.block	= &flowtable->flow_block;
	bo.command	= cmd;
	bo.binder_type	= FLOW_BLOCK_BINDER_TYPE_CLSACT_INGRESS;
	bo.extack	= &extack;
	INIT_LIST_HEAD(&bo.cb_list);

	err = dev->netdev_ops->ndo_setup_tc(dev, TC_SETUP_FT, &bo);
	if (err < 0)
		return err;

	return nf_flow_table_block_setup(flowtable, &bo, cmd);
}
EXPORT_SYMBOL_GPL(nf_flow_table_offload_setup);

int nf_flow_table_offload_init(void)
{
	INIT_WORK(&nf_flow_offload_work, flow_offload_work_handler);

	return 0;
}

void nf_flow_table_offload_exit(void)
{
	struct flow_offload_work *offload, *next;
	LIST_HEAD(offload_pending_list);

	cancel_work_sync(&nf_flow_offload_work);

	list_for_each_entry_safe(offload, next, &offload_pending_list, list) {
		list_del(&offload->list);
		kfree(offload);
	}
}