summaryrefslogtreecommitdiffstats
path: root/net/netfilter/nft_ct.c
blob: c6b8022c0e47d43e11a7f2f351f3f0650c9ba604 (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
/*
 * Copyright (c) 2008-2009 Patrick McHardy <kaber@trash.net>
 * Copyright (c) 2016 Pablo Neira Ayuso <pablo@netfilter.org>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 * Development of this code funded by Astaro AG (http://www.astaro.com/)
 */

#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/netlink.h>
#include <linux/netfilter.h>
#include <linux/netfilter/nf_tables.h>
#include <net/netfilter/nf_tables.h>
#include <net/netfilter/nf_conntrack.h>
#include <net/netfilter/nf_conntrack_acct.h>
#include <net/netfilter/nf_conntrack_tuple.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_ecache.h>
#include <net/netfilter/nf_conntrack_labels.h>

struct nft_ct {
	enum nft_ct_keys	key:8;
	enum ip_conntrack_dir	dir:8;
	union {
		enum nft_registers	dreg:8;
		enum nft_registers	sreg:8;
	};
};

#ifdef CONFIG_NF_CONNTRACK_ZONES
static DEFINE_PER_CPU(struct nf_conn *, nft_ct_pcpu_template);
static unsigned int nft_ct_pcpu_template_refcnt __read_mostly;
#endif

static u64 nft_ct_get_eval_counter(const struct nf_conn_counter *c,
				   enum nft_ct_keys k,
				   enum ip_conntrack_dir d)
{
	if (d < IP_CT_DIR_MAX)
		return k == NFT_CT_BYTES ? atomic64_read(&c[d].bytes) :
					   atomic64_read(&c[d].packets);

	return nft_ct_get_eval_counter(c, k, IP_CT_DIR_ORIGINAL) +
	       nft_ct_get_eval_counter(c, k, IP_CT_DIR_REPLY);
}

static void nft_ct_get_eval(const struct nft_expr *expr,
			    struct nft_regs *regs,
			    const struct nft_pktinfo *pkt)
{
	const struct nft_ct *priv = nft_expr_priv(expr);
	u32 *dest = &regs->data[priv->dreg];
	enum ip_conntrack_info ctinfo;
	const struct nf_conn *ct;
	const struct nf_conn_help *help;
	const struct nf_conntrack_tuple *tuple;
	const struct nf_conntrack_helper *helper;
	unsigned int state;

	ct = nf_ct_get(pkt->skb, &ctinfo);

	switch (priv->key) {
	case NFT_CT_STATE:
		if (ct == NULL)
			state = NF_CT_STATE_INVALID_BIT;
		else if (nf_ct_is_untracked(ct))
			state = NF_CT_STATE_UNTRACKED_BIT;
		else
			state = NF_CT_STATE_BIT(ctinfo);
		*dest = state;
		return;
	default:
		break;
	}

	if (ct == NULL)
		goto err;

	switch (priv->key) {
	case NFT_CT_DIRECTION:
		*dest = CTINFO2DIR(ctinfo);
		return;
	case NFT_CT_STATUS:
		*dest = ct->status;
		return;
#ifdef CONFIG_NF_CONNTRACK_MARK
	case NFT_CT_MARK:
		*dest = ct->mark;
		return;
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
	case NFT_CT_SECMARK:
		*dest = ct->secmark;
		return;
#endif
	case NFT_CT_EXPIRATION:
		*dest = jiffies_to_msecs(nf_ct_expires(ct));
		return;
	case NFT_CT_HELPER:
		if (ct->master == NULL)
			goto err;
		help = nfct_help(ct->master);
		if (help == NULL)
			goto err;
		helper = rcu_dereference(help->helper);
		if (helper == NULL)
			goto err;
		strncpy((char *)dest, helper->name, NF_CT_HELPER_NAME_LEN);
		return;
#ifdef CONFIG_NF_CONNTRACK_LABELS
	case NFT_CT_LABELS: {
		struct nf_conn_labels *labels = nf_ct_labels_find(ct);

		if (labels)
			memcpy(dest, labels->bits, NF_CT_LABELS_MAX_SIZE);
		else
			memset(dest, 0, NF_CT_LABELS_MAX_SIZE);
		return;
	}
#endif
	case NFT_CT_BYTES: /* fallthrough */
	case NFT_CT_PKTS: {
		const struct nf_conn_acct *acct = nf_conn_acct_find(ct);
		u64 count = 0;

		if (acct)
			count = nft_ct_get_eval_counter(acct->counter,
							priv->key, priv->dir);
		memcpy(dest, &count, sizeof(count));
		return;
	}
	case NFT_CT_AVGPKT: {
		const struct nf_conn_acct *acct = nf_conn_acct_find(ct);
		u64 avgcnt = 0, bcnt = 0, pcnt = 0;

		if (acct) {
			pcnt = nft_ct_get_eval_counter(acct->counter,
						       NFT_CT_PKTS, priv->dir);
			bcnt = nft_ct_get_eval_counter(acct->counter,
						       NFT_CT_BYTES, priv->dir);
			if (pcnt != 0)
				avgcnt = div64_u64(bcnt, pcnt);
		}

		memcpy(dest, &avgcnt, sizeof(avgcnt));
		return;
	}
	case NFT_CT_L3PROTOCOL:
		*dest = nf_ct_l3num(ct);
		return;
	case NFT_CT_PROTOCOL:
		*dest = nf_ct_protonum(ct);
		return;
#ifdef CONFIG_NF_CONNTRACK_ZONES
	case NFT_CT_ZONE: {
		const struct nf_conntrack_zone *zone = nf_ct_zone(ct);

		if (priv->dir < IP_CT_DIR_MAX)
			*dest = nf_ct_zone_id(zone, priv->dir);
		else
			*dest = zone->id;

		return;
	}
#endif
	default:
		break;
	}

	tuple = &ct->tuplehash[priv->dir].tuple;
	switch (priv->key) {
	case NFT_CT_SRC:
		memcpy(dest, tuple->src.u3.all,
		       nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
		return;
	case NFT_CT_DST:
		memcpy(dest, tuple->dst.u3.all,
		       nf_ct_l3num(ct) == NFPROTO_IPV4 ? 4 : 16);
		return;
	case NFT_CT_PROTO_SRC:
		*dest = (__force __u16)tuple->src.u.all;
		return;
	case NFT_CT_PROTO_DST:
		*dest = (__force __u16)tuple->dst.u.all;
		return;
	default:
		break;
	}
	return;
err:
	regs->verdict.code = NFT_BREAK;
}

#ifdef CONFIG_NF_CONNTRACK_ZONES
static void nft_ct_set_zone_eval(const struct nft_expr *expr,
				 struct nft_regs *regs,
				 const struct nft_pktinfo *pkt)
{
	struct nf_conntrack_zone zone = { .dir = NF_CT_DEFAULT_ZONE_DIR };
	const struct nft_ct *priv = nft_expr_priv(expr);
	struct sk_buff *skb = pkt->skb;
	enum ip_conntrack_info ctinfo;
	u16 value = regs->data[priv->sreg];
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct) /* already tracked */
		return;

	zone.id = value;

	switch (priv->dir) {
	case IP_CT_DIR_ORIGINAL:
		zone.dir = NF_CT_ZONE_DIR_ORIG;
		break;
	case IP_CT_DIR_REPLY:
		zone.dir = NF_CT_ZONE_DIR_REPL;
		break;
	default:
		break;
	}

	ct = this_cpu_read(nft_ct_pcpu_template);

	if (likely(atomic_read(&ct->ct_general.use) == 1)) {
		nf_ct_zone_add(ct, &zone);
	} else {
		/* previous skb got queued to userspace */
		ct = nf_ct_tmpl_alloc(nft_net(pkt), &zone, GFP_ATOMIC);
		if (!ct) {
			regs->verdict.code = NF_DROP;
			return;
		}
	}

	atomic_inc(&ct->ct_general.use);
	nf_ct_set(skb, ct, IP_CT_NEW);
}
#endif

static void nft_ct_set_eval(const struct nft_expr *expr,
			    struct nft_regs *regs,
			    const struct nft_pktinfo *pkt)
{
	const struct nft_ct *priv = nft_expr_priv(expr);
	struct sk_buff *skb = pkt->skb;
#ifdef CONFIG_NF_CONNTRACK_MARK
	u32 value = regs->data[priv->sreg];
#endif
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct == NULL)
		return;

	switch (priv->key) {
#ifdef CONFIG_NF_CONNTRACK_MARK
	case NFT_CT_MARK:
		if (ct->mark != value) {
			ct->mark = value;
			nf_conntrack_event_cache(IPCT_MARK, ct);
		}
		break;
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
	case NFT_CT_LABELS:
		nf_connlabels_replace(ct,
				      &regs->data[priv->sreg],
				      &regs->data[priv->sreg],
				      NF_CT_LABELS_MAX_SIZE / sizeof(u32));
		break;
#endif
	default:
		break;
	}
}

static const struct nla_policy nft_ct_policy[NFTA_CT_MAX + 1] = {
	[NFTA_CT_DREG]		= { .type = NLA_U32 },
	[NFTA_CT_KEY]		= { .type = NLA_U32 },
	[NFTA_CT_DIRECTION]	= { .type = NLA_U8 },
	[NFTA_CT_SREG]		= { .type = NLA_U32 },
};

static int nft_ct_netns_get(struct net *net, uint8_t family)
{
	int err;

	if (family == NFPROTO_INET) {
		err = nf_ct_netns_get(net, NFPROTO_IPV4);
		if (err < 0)
			goto err1;
		err = nf_ct_netns_get(net, NFPROTO_IPV6);
		if (err < 0)
			goto err2;
	} else {
		err = nf_ct_netns_get(net, family);
		if (err < 0)
			goto err1;
	}
	return 0;

err2:
	nf_ct_netns_put(net, NFPROTO_IPV4);
err1:
	return err;
}

static void nft_ct_netns_put(struct net *net, uint8_t family)
{
	if (family == NFPROTO_INET) {
		nf_ct_netns_put(net, NFPROTO_IPV4);
		nf_ct_netns_put(net, NFPROTO_IPV6);
	} else
		nf_ct_netns_put(net, family);
}

#ifdef CONFIG_NF_CONNTRACK_ZONES
static void nft_ct_tmpl_put_pcpu(void)
{
	struct nf_conn *ct;
	int cpu;

	for_each_possible_cpu(cpu) {
		ct = per_cpu(nft_ct_pcpu_template, cpu);
		if (!ct)
			break;
		nf_ct_put(ct);
		per_cpu(nft_ct_pcpu_template, cpu) = NULL;
	}
}

static bool nft_ct_tmpl_alloc_pcpu(void)
{
	struct nf_conntrack_zone zone = { .id = 0 };
	struct nf_conn *tmp;
	int cpu;

	if (nft_ct_pcpu_template_refcnt)
		return true;

	for_each_possible_cpu(cpu) {
		tmp = nf_ct_tmpl_alloc(&init_net, &zone, GFP_KERNEL);
		if (!tmp) {
			nft_ct_tmpl_put_pcpu();
			return false;
		}

		atomic_set(&tmp->ct_general.use, 1);
		per_cpu(nft_ct_pcpu_template, cpu) = tmp;
	}

	return true;
}
#endif

static int nft_ct_get_init(const struct nft_ctx *ctx,
			   const struct nft_expr *expr,
			   const struct nlattr * const tb[])
{
	struct nft_ct *priv = nft_expr_priv(expr);
	unsigned int len;
	int err;

	priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
	priv->dir = IP_CT_DIR_MAX;
	switch (priv->key) {
	case NFT_CT_DIRECTION:
		if (tb[NFTA_CT_DIRECTION] != NULL)
			return -EINVAL;
		len = sizeof(u8);
		break;
	case NFT_CT_STATE:
	case NFT_CT_STATUS:
#ifdef CONFIG_NF_CONNTRACK_MARK
	case NFT_CT_MARK:
#endif
#ifdef CONFIG_NF_CONNTRACK_SECMARK
	case NFT_CT_SECMARK:
#endif
	case NFT_CT_EXPIRATION:
		if (tb[NFTA_CT_DIRECTION] != NULL)
			return -EINVAL;
		len = sizeof(u32);
		break;
#ifdef CONFIG_NF_CONNTRACK_LABELS
	case NFT_CT_LABELS:
		if (tb[NFTA_CT_DIRECTION] != NULL)
			return -EINVAL;
		len = NF_CT_LABELS_MAX_SIZE;
		break;
#endif
	case NFT_CT_HELPER:
		if (tb[NFTA_CT_DIRECTION] != NULL)
			return -EINVAL;
		len = NF_CT_HELPER_NAME_LEN;
		break;

	case NFT_CT_L3PROTOCOL:
	case NFT_CT_PROTOCOL:
		/* For compatibility, do not report error if NFTA_CT_DIRECTION
		 * attribute is specified.
		 */
		len = sizeof(u8);
		break;
	case NFT_CT_SRC:
	case NFT_CT_DST:
		if (tb[NFTA_CT_DIRECTION] == NULL)
			return -EINVAL;

		switch (ctx->afi->family) {
		case NFPROTO_IPV4:
			len = FIELD_SIZEOF(struct nf_conntrack_tuple,
					   src.u3.ip);
			break;
		case NFPROTO_IPV6:
		case NFPROTO_INET:
			len = FIELD_SIZEOF(struct nf_conntrack_tuple,
					   src.u3.ip6);
			break;
		default:
			return -EAFNOSUPPORT;
		}
		break;
	case NFT_CT_PROTO_SRC:
	case NFT_CT_PROTO_DST:
		if (tb[NFTA_CT_DIRECTION] == NULL)
			return -EINVAL;
		len = FIELD_SIZEOF(struct nf_conntrack_tuple, src.u.all);
		break;
	case NFT_CT_BYTES:
	case NFT_CT_PKTS:
	case NFT_CT_AVGPKT:
		len = sizeof(u64);
		break;
#ifdef CONFIG_NF_CONNTRACK_ZONES
	case NFT_CT_ZONE:
		len = sizeof(u16);
		break;
#endif
	default:
		return -EOPNOTSUPP;
	}

	if (tb[NFTA_CT_DIRECTION] != NULL) {
		priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]);
		switch (priv->dir) {
		case IP_CT_DIR_ORIGINAL:
		case IP_CT_DIR_REPLY:
			break;
		default:
			return -EINVAL;
		}
	}

	priv->dreg = nft_parse_register(tb[NFTA_CT_DREG]);
	err = nft_validate_register_store(ctx, priv->dreg, NULL,
					  NFT_DATA_VALUE, len);
	if (err < 0)
		return err;

	err = nft_ct_netns_get(ctx->net, ctx->afi->family);
	if (err < 0)
		return err;

	if (priv->key == NFT_CT_BYTES ||
	    priv->key == NFT_CT_PKTS  ||
	    priv->key == NFT_CT_AVGPKT)
		nf_ct_set_acct(ctx->net, true);

	return 0;
}

static void __nft_ct_set_destroy(const struct nft_ctx *ctx, struct nft_ct *priv)
{
	switch (priv->key) {
#ifdef CONFIG_NF_CONNTRACK_LABELS
	case NFT_CT_LABELS:
		nf_connlabels_put(ctx->net);
		break;
#endif
#ifdef CONFIG_NF_CONNTRACK_ZONES
	case NFT_CT_ZONE:
		if (--nft_ct_pcpu_template_refcnt == 0)
			nft_ct_tmpl_put_pcpu();
#endif
	default:
		break;
	}
}

static int nft_ct_set_init(const struct nft_ctx *ctx,
			   const struct nft_expr *expr,
			   const struct nlattr * const tb[])
{
	struct nft_ct *priv = nft_expr_priv(expr);
	unsigned int len;
	int err;

	priv->dir = IP_CT_DIR_MAX;
	priv->key = ntohl(nla_get_be32(tb[NFTA_CT_KEY]));
	switch (priv->key) {
#ifdef CONFIG_NF_CONNTRACK_MARK
	case NFT_CT_MARK:
		if (tb[NFTA_CT_DIRECTION])
			return -EINVAL;
		len = FIELD_SIZEOF(struct nf_conn, mark);
		break;
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
	case NFT_CT_LABELS:
		if (tb[NFTA_CT_DIRECTION])
			return -EINVAL;
		len = NF_CT_LABELS_MAX_SIZE;
		err = nf_connlabels_get(ctx->net, (len * BITS_PER_BYTE) - 1);
		if (err)
			return err;
		break;
#endif
#ifdef CONFIG_NF_CONNTRACK_ZONES
	case NFT_CT_ZONE:
		if (!nft_ct_tmpl_alloc_pcpu())
			return -ENOMEM;
		nft_ct_pcpu_template_refcnt++;
		break;
#endif
	default:
		return -EOPNOTSUPP;
	}

	if (tb[NFTA_CT_DIRECTION]) {
		priv->dir = nla_get_u8(tb[NFTA_CT_DIRECTION]);
		switch (priv->dir) {
		case IP_CT_DIR_ORIGINAL:
		case IP_CT_DIR_REPLY:
			break;
		default:
			return -EINVAL;
		}
	}

	priv->sreg = nft_parse_register(tb[NFTA_CT_SREG]);
	err = nft_validate_register_load(priv->sreg, len);
	if (err < 0)
		goto err1;

	err = nft_ct_netns_get(ctx->net, ctx->afi->family);
	if (err < 0)
		goto err1;

	return 0;

err1:
	__nft_ct_set_destroy(ctx, priv);
	return err;
}

static void nft_ct_get_destroy(const struct nft_ctx *ctx,
			       const struct nft_expr *expr)
{
	nf_ct_netns_put(ctx->net, ctx->afi->family);
}

static void nft_ct_set_destroy(const struct nft_ctx *ctx,
			       const struct nft_expr *expr)
{
	struct nft_ct *priv = nft_expr_priv(expr);

	__nft_ct_set_destroy(ctx, priv);
	nft_ct_netns_put(ctx->net, ctx->afi->family);
}

static int nft_ct_get_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_ct *priv = nft_expr_priv(expr);

	if (nft_dump_register(skb, NFTA_CT_DREG, priv->dreg))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key)))
		goto nla_put_failure;

	switch (priv->key) {
	case NFT_CT_SRC:
	case NFT_CT_DST:
	case NFT_CT_PROTO_SRC:
	case NFT_CT_PROTO_DST:
		if (nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir))
			goto nla_put_failure;
		break;
	case NFT_CT_BYTES:
	case NFT_CT_PKTS:
	case NFT_CT_AVGPKT:
	case NFT_CT_ZONE:
		if (priv->dir < IP_CT_DIR_MAX &&
		    nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir))
			goto nla_put_failure;
		break;
	default:
		break;
	}

	return 0;

nla_put_failure:
	return -1;
}

static int nft_ct_set_dump(struct sk_buff *skb, const struct nft_expr *expr)
{
	const struct nft_ct *priv = nft_expr_priv(expr);

	if (nft_dump_register(skb, NFTA_CT_SREG, priv->sreg))
		goto nla_put_failure;
	if (nla_put_be32(skb, NFTA_CT_KEY, htonl(priv->key)))
		goto nla_put_failure;

	switch (priv->key) {
	case NFT_CT_ZONE:
		if (priv->dir < IP_CT_DIR_MAX &&
		    nla_put_u8(skb, NFTA_CT_DIRECTION, priv->dir))
			goto nla_put_failure;
		break;
	default:
		break;
	}

	return 0;

nla_put_failure:
	return -1;
}

static struct nft_expr_type nft_ct_type;
static const struct nft_expr_ops nft_ct_get_ops = {
	.type		= &nft_ct_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_ct)),
	.eval		= nft_ct_get_eval,
	.init		= nft_ct_get_init,
	.destroy	= nft_ct_get_destroy,
	.dump		= nft_ct_get_dump,
};

static const struct nft_expr_ops nft_ct_set_ops = {
	.type		= &nft_ct_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_ct)),
	.eval		= nft_ct_set_eval,
	.init		= nft_ct_set_init,
	.destroy	= nft_ct_set_destroy,
	.dump		= nft_ct_set_dump,
};

#ifdef CONFIG_NF_CONNTRACK_ZONES
static const struct nft_expr_ops nft_ct_set_zone_ops = {
	.type		= &nft_ct_type,
	.size		= NFT_EXPR_SIZE(sizeof(struct nft_ct)),
	.eval		= nft_ct_set_zone_eval,
	.init		= nft_ct_set_init,
	.destroy	= nft_ct_set_destroy,
	.dump		= nft_ct_set_dump,
};
#endif

static const struct nft_expr_ops *
nft_ct_select_ops(const struct nft_ctx *ctx,
		    const struct nlattr * const tb[])
{
	if (tb[NFTA_CT_KEY] == NULL)
		return ERR_PTR(-EINVAL);

	if (tb[NFTA_CT_DREG] && tb[NFTA_CT_SREG])
		return ERR_PTR(-EINVAL);

	if (tb[NFTA_CT_DREG])
		return &nft_ct_get_ops;

	if (tb[NFTA_CT_SREG]) {
#ifdef CONFIG_NF_CONNTRACK_ZONES
		if (nla_get_be32(tb[NFTA_CT_KEY]) == htonl(NFT_CT_ZONE))
			return &nft_ct_set_zone_ops;
#endif
		return &nft_ct_set_ops;
	}

	return ERR_PTR(-EINVAL);
}

static struct nft_expr_type nft_ct_type __read_mostly = {
	.name		= "ct",
	.select_ops	= &nft_ct_select_ops,
	.policy		= nft_ct_policy,
	.maxattr	= NFTA_CT_MAX,
	.owner		= THIS_MODULE,
};

static void nft_notrack_eval(const struct nft_expr *expr,
			     struct nft_regs *regs,
			     const struct nft_pktinfo *pkt)
{
	struct sk_buff *skb = pkt->skb;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(pkt->skb, &ctinfo);
	/* Previously seen (loopback or untracked)?  Ignore. */
	if (ct)
		return;

	ct = nf_ct_untracked_get();
	atomic_inc(&ct->ct_general.use);
	nf_ct_set(skb, ct, IP_CT_NEW);
}

static struct nft_expr_type nft_notrack_type;
static const struct nft_expr_ops nft_notrack_ops = {
	.type		= &nft_notrack_type,
	.size		= NFT_EXPR_SIZE(0),
	.eval		= nft_notrack_eval,
};

static struct nft_expr_type nft_notrack_type __read_mostly = {
	.name		= "notrack",
	.ops		= &nft_notrack_ops,
	.owner		= THIS_MODULE,
};

static int __init nft_ct_module_init(void)
{
	int err;

	BUILD_BUG_ON(NF_CT_LABELS_MAX_SIZE > NFT_REG_SIZE);

	err = nft_register_expr(&nft_ct_type);
	if (err < 0)
		return err;

	err = nft_register_expr(&nft_notrack_type);
	if (err < 0)
		goto err1;

	return 0;
err1:
	nft_unregister_expr(&nft_ct_type);
	return err;
}

static void __exit nft_ct_module_exit(void)
{
	nft_unregister_expr(&nft_notrack_type);
	nft_unregister_expr(&nft_ct_type);
}

module_init(nft_ct_module_init);
module_exit(nft_ct_module_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Patrick McHardy <kaber@trash.net>");
MODULE_ALIAS_NFT_EXPR("ct");
MODULE_ALIAS_NFT_EXPR("notrack");