summaryrefslogtreecommitdiff
path: root/net/openvswitch/conntrack.c
blob: 9741a76c740504c677a81505a6204f10ed0d8902 (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
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
/*
 * Copyright (c) 2015 Nicira, Inc.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * General Public License for more details.
 */

#include <linux/module.h>
#include <linux/openvswitch.h>
#include <linux/tcp.h>
#include <linux/udp.h>
#include <linux/sctp.h>
#include <net/ip.h>
#include <net/netfilter/nf_conntrack_core.h>
#include <net/netfilter/nf_conntrack_helper.h>
#include <net/netfilter/nf_conntrack_labels.h>
#include <net/netfilter/nf_conntrack_seqadj.h>
#include <net/netfilter/nf_conntrack_zones.h>
#include <net/netfilter/ipv6/nf_defrag_ipv6.h>

#ifdef CONFIG_NF_NAT_NEEDED
#include <linux/netfilter/nf_nat.h>
#include <net/netfilter/nf_nat_core.h>
#include <net/netfilter/nf_nat_l3proto.h>
#endif

#include "datapath.h"
#include "conntrack.h"
#include "flow.h"
#include "flow_netlink.h"

struct ovs_ct_len_tbl {
	int maxlen;
	int minlen;
};

/* Metadata mark for masked write to conntrack mark */
struct md_mark {
	u32 value;
	u32 mask;
};

/* Metadata label for masked write to conntrack label. */
struct md_labels {
	struct ovs_key_ct_labels value;
	struct ovs_key_ct_labels mask;
};

enum ovs_ct_nat {
	OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
	OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
	OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
};

/* Conntrack action context for execution. */
struct ovs_conntrack_info {
	struct nf_conntrack_helper *helper;
	struct nf_conntrack_zone zone;
	struct nf_conn *ct;
	u8 commit : 1;
	u8 nat : 3;                 /* enum ovs_ct_nat */
	u16 family;
	struct md_mark mark;
	struct md_labels labels;
#ifdef CONFIG_NF_NAT_NEEDED
	struct nf_nat_range range;  /* Only present for SRC NAT and DST NAT. */
#endif
};

static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);

static u16 key_to_nfproto(const struct sw_flow_key *key)
{
	switch (ntohs(key->eth.type)) {
	case ETH_P_IP:
		return NFPROTO_IPV4;
	case ETH_P_IPV6:
		return NFPROTO_IPV6;
	default:
		return NFPROTO_UNSPEC;
	}
}

/* Map SKB connection state into the values used by flow definition. */
static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
{
	u8 ct_state = OVS_CS_F_TRACKED;

	switch (ctinfo) {
	case IP_CT_ESTABLISHED_REPLY:
	case IP_CT_RELATED_REPLY:
		ct_state |= OVS_CS_F_REPLY_DIR;
		break;
	default:
		break;
	}

	switch (ctinfo) {
	case IP_CT_ESTABLISHED:
	case IP_CT_ESTABLISHED_REPLY:
		ct_state |= OVS_CS_F_ESTABLISHED;
		break;
	case IP_CT_RELATED:
	case IP_CT_RELATED_REPLY:
		ct_state |= OVS_CS_F_RELATED;
		break;
	case IP_CT_NEW:
		ct_state |= OVS_CS_F_NEW;
		break;
	default:
		break;
	}

	return ct_state;
}

static u32 ovs_ct_get_mark(const struct nf_conn *ct)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
	return ct ? ct->mark : 0;
#else
	return 0;
#endif
}

static void ovs_ct_get_labels(const struct nf_conn *ct,
			      struct ovs_key_ct_labels *labels)
{
	struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;

	if (cl) {
		size_t len = cl->words * sizeof(long);

		if (len > OVS_CT_LABELS_LEN)
			len = OVS_CT_LABELS_LEN;
		else if (len < OVS_CT_LABELS_LEN)
			memset(labels, 0, OVS_CT_LABELS_LEN);
		memcpy(labels, cl->bits, len);
	} else {
		memset(labels, 0, OVS_CT_LABELS_LEN);
	}
}

static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
				const struct nf_conntrack_zone *zone,
				const struct nf_conn *ct)
{
	key->ct.state = state;
	key->ct.zone = zone->id;
	key->ct.mark = ovs_ct_get_mark(ct);
	ovs_ct_get_labels(ct, &key->ct.labels);
}

/* Update 'key' based on skb->nfct.  If 'post_ct' is true, then OVS has
 * previously sent the packet to conntrack via the ct action.  If
 * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
 * initialized from the connection status.
 */
static void ovs_ct_update_key(const struct sk_buff *skb,
			      const struct ovs_conntrack_info *info,
			      struct sw_flow_key *key, bool post_ct,
			      bool keep_nat_flags)
{
	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	u8 state = 0;

	ct = nf_ct_get(skb, &ctinfo);
	if (ct) {
		state = ovs_ct_get_state(ctinfo);
		/* All unconfirmed entries are NEW connections. */
		if (!nf_ct_is_confirmed(ct))
			state |= OVS_CS_F_NEW;
		/* OVS persists the related flag for the duration of the
		 * connection.
		 */
		if (ct->master)
			state |= OVS_CS_F_RELATED;
		if (keep_nat_flags) {
			state |= key->ct.state & OVS_CS_F_NAT_MASK;
		} else {
			if (ct->status & IPS_SRC_NAT)
				state |= OVS_CS_F_SRC_NAT;
			if (ct->status & IPS_DST_NAT)
				state |= OVS_CS_F_DST_NAT;
		}
		zone = nf_ct_zone(ct);
	} else if (post_ct) {
		state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
		if (info)
			zone = &info->zone;
	}
	__ovs_ct_update_key(key, state, zone, ct);
}

/* This is called to initialize CT key fields possibly coming in from the local
 * stack.
 */
void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
{
	ovs_ct_update_key(skb, NULL, key, false, false);
}

int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
{
	if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
		return -EMSGSIZE;

	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
		return -EMSGSIZE;

	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
		return -EMSGSIZE;

	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
		    &key->ct.labels))
		return -EMSGSIZE;

	return 0;
}

static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
			   u32 ct_mark, u32 mask)
{
#if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	u32 new_mark;

	/* The connection could be invalid, in which case set_mark is no-op. */
	ct = nf_ct_get(skb, &ctinfo);
	if (!ct)
		return 0;

	new_mark = ct_mark | (ct->mark & ~(mask));
	if (ct->mark != new_mark) {
		ct->mark = new_mark;
		nf_conntrack_event_cache(IPCT_MARK, ct);
		key->ct.mark = new_mark;
	}

	return 0;
#else
	return -ENOTSUPP;
#endif
}

static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
			     const struct ovs_key_ct_labels *labels,
			     const struct ovs_key_ct_labels *mask)
{
	enum ip_conntrack_info ctinfo;
	struct nf_conn_labels *cl;
	struct nf_conn *ct;
	int err;

	/* The connection could be invalid, in which case set_label is no-op.*/
	ct = nf_ct_get(skb, &ctinfo);
	if (!ct)
		return 0;

	cl = nf_ct_labels_find(ct);
	if (!cl) {
		nf_ct_labels_ext_add(ct);
		cl = nf_ct_labels_find(ct);
	}
	if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
		return -ENOSPC;

	err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
				    OVS_CT_LABELS_LEN / sizeof(u32));
	if (err)
		return err;

	ovs_ct_get_labels(ct, &key->ct.labels);
	return 0;
}

/* 'skb' should already be pulled to nh_ofs. */
static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
{
	const struct nf_conntrack_helper *helper;
	const struct nf_conn_help *help;
	enum ip_conntrack_info ctinfo;
	unsigned int protoff;
	struct nf_conn *ct;
	int err;

	ct = nf_ct_get(skb, &ctinfo);
	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
		return NF_ACCEPT;

	help = nfct_help(ct);
	if (!help)
		return NF_ACCEPT;

	helper = rcu_dereference(help->helper);
	if (!helper)
		return NF_ACCEPT;

	switch (proto) {
	case NFPROTO_IPV4:
		protoff = ip_hdrlen(skb);
		break;
	case NFPROTO_IPV6: {
		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
		__be16 frag_off;
		int ofs;

		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
				       &frag_off);
		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
			pr_debug("proto header not found\n");
			return NF_ACCEPT;
		}
		protoff = ofs;
		break;
	}
	default:
		WARN_ONCE(1, "helper invoked on non-IP family!");
		return NF_DROP;
	}

	err = helper->help(skb, protoff, ct, ctinfo);
	if (err != NF_ACCEPT)
		return err;

	/* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
	 * FTP with NAT) adusting the TCP payload size when mangling IP
	 * addresses and/or port numbers in the text-based control connection.
	 */
	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
	    !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
		return NF_DROP;
	return NF_ACCEPT;
}

/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 * value if 'skb' is freed.
 */
static int handle_fragments(struct net *net, struct sw_flow_key *key,
			    u16 zone, struct sk_buff *skb)
{
	struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
	int err;

	if (key->eth.type == htons(ETH_P_IP)) {
		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;

		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
		err = ip_defrag(net, skb, user);
		if (err)
			return err;

		ovs_cb.mru = IPCB(skb)->frag_max_size;
#if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
	} else if (key->eth.type == htons(ETH_P_IPV6)) {
		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;

		skb_orphan(skb);
		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
		err = nf_ct_frag6_gather(net, skb, user);
		if (err)
			return err;

		key->ip.proto = ipv6_hdr(skb)->nexthdr;
		ovs_cb.mru = IP6CB(skb)->frag_max_size;
#endif
	} else {
		kfree_skb(skb);
		return -EPFNOSUPPORT;
	}

	key->ip.frag = OVS_FRAG_TYPE_NONE;
	skb_clear_hash(skb);
	skb->ignore_df = 1;
	*OVS_CB(skb) = ovs_cb;

	return 0;
}

static struct nf_conntrack_expect *
ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
		   u16 proto, const struct sk_buff *skb)
{
	struct nf_conntrack_tuple tuple;

	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
		return NULL;
	return __nf_ct_expect_find(net, zone, &tuple);
}

/* This replicates logic from nf_conntrack_core.c that is not exported. */
static enum ip_conntrack_info
ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
{
	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);

	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
		return IP_CT_ESTABLISHED_REPLY;
	/* Once we've had two way comms, always ESTABLISHED. */
	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
		return IP_CT_ESTABLISHED;
	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
		return IP_CT_RELATED;
	return IP_CT_NEW;
}

/* Find an existing connection which this packet belongs to without
 * re-attributing statistics or modifying the connection state.  This allows an
 * skb->nfct lost due to an upcall to be recovered during actions execution.
 *
 * Must be called with rcu_read_lock.
 *
 * On success, populates skb->nfct and skb->nfctinfo, and returns the
 * connection.  Returns NULL if there is no existing entry.
 */
static struct nf_conn *
ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
		     u8 l3num, struct sk_buff *skb)
{
	struct nf_conntrack_l3proto *l3proto;
	struct nf_conntrack_l4proto *l4proto;
	struct nf_conntrack_tuple tuple;
	struct nf_conntrack_tuple_hash *h;
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;
	unsigned int dataoff;
	u8 protonum;

	l3proto = __nf_ct_l3proto_find(l3num);
	if (!l3proto) {
		pr_debug("ovs_ct_find_existing: Can't get l3proto\n");
		return NULL;
	}
	if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
				 &protonum) <= 0) {
		pr_debug("ovs_ct_find_existing: Can't get protonum\n");
		return NULL;
	}
	l4proto = __nf_ct_l4proto_find(l3num, protonum);
	if (!l4proto) {
		pr_debug("ovs_ct_find_existing: Can't get l4proto\n");
		return NULL;
	}
	if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
			     protonum, net, &tuple, l3proto, l4proto)) {
		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
		return NULL;
	}

	/* look for tuple match */
	h = nf_conntrack_find_get(net, zone, &tuple);
	if (!h)
		return NULL;   /* Not found. */

	ct = nf_ct_tuplehash_to_ctrack(h);

	ctinfo = ovs_ct_get_info(h);
	if (ctinfo == IP_CT_NEW) {
		/* This should not happen. */
		WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
	}
	skb->nfct = &ct->ct_general;
	skb->nfctinfo = ctinfo;
	return ct;
}

/* Determine whether skb->nfct is equal to the result of conntrack lookup. */
static bool skb_nfct_cached(struct net *net,
			    const struct sw_flow_key *key,
			    const struct ovs_conntrack_info *info,
			    struct sk_buff *skb)
{
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	ct = nf_ct_get(skb, &ctinfo);
	/* If no ct, check if we have evidence that an existing conntrack entry
	 * might be found for this skb.  This happens when we lose a skb->nfct
	 * due to an upcall.  If the connection was not confirmed, it is not
	 * cached and needs to be run through conntrack again.
	 */
	if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
	    !(key->ct.state & OVS_CS_F_INVALID) &&
	    key->ct.zone == info->zone.id)
		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
	if (!ct)
		return false;
	if (!net_eq(net, read_pnet(&ct->ct_net)))
		return false;
	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
		return false;
	if (info->helper) {
		struct nf_conn_help *help;

		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
		if (help && rcu_access_pointer(help->helper) != info->helper)
			return false;
	}

	return true;
}

#ifdef CONFIG_NF_NAT_NEEDED
/* Modelled after nf_nat_ipv[46]_fn().
 * range is only used for new, uninitialized NAT state.
 * Returns either NF_ACCEPT or NF_DROP.
 */
static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
			      enum ip_conntrack_info ctinfo,
			      const struct nf_nat_range *range,
			      enum nf_nat_manip_type maniptype)
{
	int hooknum, nh_off, err = NF_ACCEPT;

	nh_off = skb_network_offset(skb);
	skb_pull(skb, nh_off);

	/* See HOOK2MANIP(). */
	if (maniptype == NF_NAT_MANIP_SRC)
		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
	else
		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */

	switch (ctinfo) {
	case IP_CT_RELATED:
	case IP_CT_RELATED_REPLY:
		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
		    skb->protocol == htons(ETH_P_IP) &&
		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
							   hooknum))
				err = NF_DROP;
			goto push;
		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
			   skb->protocol == htons(ETH_P_IPV6)) {
			__be16 frag_off;
			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
			int hdrlen = ipv6_skip_exthdr(skb,
						      sizeof(struct ipv6hdr),
						      &nexthdr, &frag_off);

			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
				if (!nf_nat_icmpv6_reply_translation(skb, ct,
								     ctinfo,
								     hooknum,
								     hdrlen))
					err = NF_DROP;
				goto push;
			}
		}
		/* Non-ICMP, fall thru to initialize if needed. */
	case IP_CT_NEW:
		/* Seen it before?  This can happen for loopback, retrans,
		 * or local packets.
		 */
		if (!nf_nat_initialized(ct, maniptype)) {
			/* Initialize according to the NAT action. */
			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
				/* Action is set up to establish a new
				 * mapping.
				 */
				? nf_nat_setup_info(ct, range, maniptype)
				: nf_nat_alloc_null_binding(ct, hooknum);
			if (err != NF_ACCEPT)
				goto push;
		}
		break;

	case IP_CT_ESTABLISHED:
	case IP_CT_ESTABLISHED_REPLY:
		break;

	default:
		err = NF_DROP;
		goto push;
	}

	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
push:
	skb_push(skb, nh_off);

	return err;
}

static void ovs_nat_update_key(struct sw_flow_key *key,
			       const struct sk_buff *skb,
			       enum nf_nat_manip_type maniptype)
{
	if (maniptype == NF_NAT_MANIP_SRC) {
		__be16 src;

		key->ct.state |= OVS_CS_F_SRC_NAT;
		if (key->eth.type == htons(ETH_P_IP))
			key->ipv4.addr.src = ip_hdr(skb)->saddr;
		else if (key->eth.type == htons(ETH_P_IPV6))
			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
			       sizeof(key->ipv6.addr.src));
		else
			return;

		if (key->ip.proto == IPPROTO_UDP)
			src = udp_hdr(skb)->source;
		else if (key->ip.proto == IPPROTO_TCP)
			src = tcp_hdr(skb)->source;
		else if (key->ip.proto == IPPROTO_SCTP)
			src = sctp_hdr(skb)->source;
		else
			return;

		key->tp.src = src;
	} else {
		__be16 dst;

		key->ct.state |= OVS_CS_F_DST_NAT;
		if (key->eth.type == htons(ETH_P_IP))
			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
		else if (key->eth.type == htons(ETH_P_IPV6))
			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
			       sizeof(key->ipv6.addr.dst));
		else
			return;

		if (key->ip.proto == IPPROTO_UDP)
			dst = udp_hdr(skb)->dest;
		else if (key->ip.proto == IPPROTO_TCP)
			dst = tcp_hdr(skb)->dest;
		else if (key->ip.proto == IPPROTO_SCTP)
			dst = sctp_hdr(skb)->dest;
		else
			return;

		key->tp.dst = dst;
	}
}

/* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
		      const struct ovs_conntrack_info *info,
		      struct sk_buff *skb, struct nf_conn *ct,
		      enum ip_conntrack_info ctinfo)
{
	enum nf_nat_manip_type maniptype;
	int err;

	if (nf_ct_is_untracked(ct)) {
		/* A NAT action may only be performed on tracked packets. */
		return NF_ACCEPT;
	}

	/* Add NAT extension if not confirmed yet. */
	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
		return NF_ACCEPT;   /* Can't NAT. */

	/* Determine NAT type.
	 * Check if the NAT type can be deduced from the tracked connection.
	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
	 * when committing.
	 */
	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
	    ct->status & IPS_NAT_MASK &&
	    (ctinfo != IP_CT_RELATED || info->commit)) {
		/* NAT an established or related connection like before. */
		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
			/* This is the REPLY direction for a connection
			 * for which NAT was applied in the forward
			 * direction.  Do the reverse NAT.
			 */
			maniptype = ct->status & IPS_SRC_NAT
				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
		else
			maniptype = ct->status & IPS_SRC_NAT
				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
	} else if (info->nat & OVS_CT_SRC_NAT) {
		maniptype = NF_NAT_MANIP_SRC;
	} else if (info->nat & OVS_CT_DST_NAT) {
		maniptype = NF_NAT_MANIP_DST;
	} else {
		return NF_ACCEPT; /* Connection is not NATed. */
	}
	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);

	/* Mark NAT done if successful and update the flow key. */
	if (err == NF_ACCEPT)
		ovs_nat_update_key(key, skb, maniptype);

	return err;
}
#else /* !CONFIG_NF_NAT_NEEDED */
static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
		      const struct ovs_conntrack_info *info,
		      struct sk_buff *skb, struct nf_conn *ct,
		      enum ip_conntrack_info ctinfo)
{
	return NF_ACCEPT;
}
#endif

/* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
 * not done already.  Update key with new CT state after passing the packet
 * through conntrack.
 * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
 * set to NULL and 0 will be returned.
 */
static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
			   const struct ovs_conntrack_info *info,
			   struct sk_buff *skb)
{
	/* If we are recirculating packets to match on conntrack fields and
	 * committing with a separate conntrack action,  then we don't need to
	 * actually run the packet through conntrack twice unless it's for a
	 * different zone.
	 */
	bool cached = skb_nfct_cached(net, key, info, skb);
	enum ip_conntrack_info ctinfo;
	struct nf_conn *ct;

	if (!cached) {
		struct nf_conn *tmpl = info->ct;
		int err;

		/* Associate skb with specified zone. */
		if (tmpl) {
			if (skb->nfct)
				nf_conntrack_put(skb->nfct);
			nf_conntrack_get(&tmpl->ct_general);
			skb->nfct = &tmpl->ct_general;
			skb->nfctinfo = IP_CT_NEW;
		}

		/* Repeat if requested, see nf_iterate(). */
		do {
			err = nf_conntrack_in(net, info->family,
					      NF_INET_PRE_ROUTING, skb);
		} while (err == NF_REPEAT);

		if (err != NF_ACCEPT)
			return -ENOENT;

		/* Clear CT state NAT flags to mark that we have not yet done
		 * NAT after the nf_conntrack_in() call.  We can actually clear
		 * the whole state, as it will be re-initialized below.
		 */
		key->ct.state = 0;

		/* Update the key, but keep the NAT flags. */
		ovs_ct_update_key(skb, info, key, true, true);
	}

	ct = nf_ct_get(skb, &ctinfo);
	if (ct) {
		/* Packets starting a new connection must be NATted before the
		 * helper, so that the helper knows about the NAT.  We enforce
		 * this by delaying both NAT and helper calls for unconfirmed
		 * connections until the committing CT action.  For later
		 * packets NAT and Helper may be called in either order.
		 *
		 * NAT will be done only if the CT action has NAT, and only
		 * once per packet (per zone), as guarded by the NAT bits in
		 * the key->ct.state.
		 */
		if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
		    (nf_ct_is_confirmed(ct) || info->commit) &&
		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
			return -EINVAL;
		}

		/* Call the helper only if:
		 * - nf_conntrack_in() was executed above ("!cached") for a
		 *   confirmed connection, or
		 * - When committing an unconfirmed connection.
		 */
		if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
			return -EINVAL;
		}
	}

	return 0;
}

/* Lookup connection and read fields into key. */
static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
			 const struct ovs_conntrack_info *info,
			 struct sk_buff *skb)
{
	struct nf_conntrack_expect *exp;

	/* If we pass an expected packet through nf_conntrack_in() the
	 * expectation is typically removed, but the packet could still be
	 * lost in upcall processing.  To prevent this from happening we
	 * perform an explicit expectation lookup.  Expected connections are
	 * always new, and will be passed through conntrack only when they are
	 * committed, as it is OK to remove the expectation at that time.
	 */
	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
	if (exp) {
		u8 state;

		/* NOTE: New connections are NATted and Helped only when
		 * committed, so we are not calling into NAT here.
		 */
		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
		__ovs_ct_update_key(key, state, &info->zone, exp->master);
	} else
		return __ovs_ct_lookup(net, key, info, skb);

	return 0;
}

/* Lookup connection and confirm if unconfirmed. */
static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
			 const struct ovs_conntrack_info *info,
			 struct sk_buff *skb)
{
	int err;

	err = __ovs_ct_lookup(net, key, info, skb);
	if (err)
		return err;
	/* This is a no-op if the connection has already been confirmed. */
	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
		return -EINVAL;

	return 0;
}

static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
{
	size_t i;

	for (i = 0; i < sizeof(*labels); i++)
		if (labels->ct_labels[i])
			return true;

	return false;
}

/* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
 * value if 'skb' is freed.
 */
int ovs_ct_execute(struct net *net, struct sk_buff *skb,
		   struct sw_flow_key *key,
		   const struct ovs_conntrack_info *info)
{
	int nh_ofs;
	int err;

	/* The conntrack module expects to be working at L3. */
	nh_ofs = skb_network_offset(skb);
	skb_pull(skb, nh_ofs);

	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
		err = handle_fragments(net, key, info->zone.id, skb);
		if (err)
			return err;
	}

	if (info->commit)
		err = ovs_ct_commit(net, key, info, skb);
	else
		err = ovs_ct_lookup(net, key, info, skb);
	if (err)
		goto err;

	if (info->mark.mask) {
		err = ovs_ct_set_mark(skb, key, info->mark.value,
				      info->mark.mask);
		if (err)
			goto err;
	}
	if (labels_nonzero(&info->labels.mask))
		err = ovs_ct_set_labels(skb, key, &info->labels.value,
					&info->labels.mask);
err:
	skb_push(skb, nh_ofs);
	if (err)
		kfree_skb(skb);
	return err;
}

static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
			     const struct sw_flow_key *key, bool log)
{
	struct nf_conntrack_helper *helper;
	struct nf_conn_help *help;

	helper = nf_conntrack_helper_try_module_get(name, info->family,
						    key->ip.proto);
	if (!helper) {
		OVS_NLERR(log, "Unknown helper \"%s\"", name);
		return -EINVAL;
	}

	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
	if (!help) {
		module_put(helper->me);
		return -ENOMEM;
	}

	rcu_assign_pointer(help->helper, helper);
	info->helper = helper;
	return 0;
}

#ifdef CONFIG_NF_NAT_NEEDED
static int parse_nat(const struct nlattr *attr,
		     struct ovs_conntrack_info *info, bool log)
{
	struct nlattr *a;
	int rem;
	bool have_ip_max = false;
	bool have_proto_max = false;
	bool ip_vers = (info->family == NFPROTO_IPV6);

	nla_for_each_nested(a, attr, rem) {
		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
			[OVS_NAT_ATTR_SRC] = {0, 0},
			[OVS_NAT_ATTR_DST] = {0, 0},
			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
						 sizeof(struct in6_addr)},
			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
						 sizeof(struct in6_addr)},
			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
		};
		int type = nla_type(a);

		if (type > OVS_NAT_ATTR_MAX) {
			OVS_NLERR(log,
				  "Unknown NAT attribute (type=%d, max=%d).\n",
				  type, OVS_NAT_ATTR_MAX);
			return -EINVAL;
		}

		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
			OVS_NLERR(log,
				  "NAT attribute type %d has unexpected length (%d != %d).\n",
				  type, nla_len(a),
				  ovs_nat_attr_lens[type][ip_vers]);
			return -EINVAL;
		}

		switch (type) {
		case OVS_NAT_ATTR_SRC:
		case OVS_NAT_ATTR_DST:
			if (info->nat) {
				OVS_NLERR(log,
					  "Only one type of NAT may be specified.\n"
					  );
				return -ERANGE;
			}
			info->nat |= OVS_CT_NAT;
			info->nat |= ((type == OVS_NAT_ATTR_SRC)
					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
			break;

		case OVS_NAT_ATTR_IP_MIN:
			nla_memcpy(&info->range.min_addr, a,
				   sizeof(info->range.min_addr));
			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
			break;

		case OVS_NAT_ATTR_IP_MAX:
			have_ip_max = true;
			nla_memcpy(&info->range.max_addr, a,
				   sizeof(info->range.max_addr));
			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
			break;

		case OVS_NAT_ATTR_PROTO_MIN:
			info->range.min_proto.all = htons(nla_get_u16(a));
			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
			break;

		case OVS_NAT_ATTR_PROTO_MAX:
			have_proto_max = true;
			info->range.max_proto.all = htons(nla_get_u16(a));
			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
			break;

		case OVS_NAT_ATTR_PERSISTENT:
			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
			break;

		case OVS_NAT_ATTR_PROTO_HASH:
			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
			break;

		case OVS_NAT_ATTR_PROTO_RANDOM:
			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
			break;

		default:
			OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
			return -EINVAL;
		}
	}

	if (rem > 0) {
		OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
		return -EINVAL;
	}
	if (!info->nat) {
		/* Do not allow flags if no type is given. */
		if (info->range.flags) {
			OVS_NLERR(log,
				  "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
				  );
			return -EINVAL;
		}
		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
	} else if (!info->commit) {
		OVS_NLERR(log,
			  "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
			  );
		return -EINVAL;
	}
	/* Allow missing IP_MAX. */
	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
		memcpy(&info->range.max_addr, &info->range.min_addr,
		       sizeof(info->range.max_addr));
	}
	/* Allow missing PROTO_MAX. */
	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
	    !have_proto_max) {
		info->range.max_proto.all = info->range.min_proto.all;
	}
	return 0;
}
#endif

static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
				    .maxlen = sizeof(u16) },
	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
				    .maxlen = sizeof(struct md_mark) },
	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
				    .maxlen = sizeof(struct md_labels) },
	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
				    .maxlen = NF_CT_HELPER_NAME_LEN },
#ifdef CONFIG_NF_NAT_NEEDED
	/* NAT length is checked when parsing the nested attributes. */
	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
#endif
};

static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
		    const char **helper, bool log)
{
	struct nlattr *a;
	int rem;

	nla_for_each_nested(a, attr, rem) {
		int type = nla_type(a);
		int maxlen = ovs_ct_attr_lens[type].maxlen;
		int minlen = ovs_ct_attr_lens[type].minlen;

		if (type > OVS_CT_ATTR_MAX) {
			OVS_NLERR(log,
				  "Unknown conntrack attr (type=%d, max=%d)",
				  type, OVS_CT_ATTR_MAX);
			return -EINVAL;
		}
		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
			OVS_NLERR(log,
				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
				  type, nla_len(a), maxlen);
			return -EINVAL;
		}

		switch (type) {
		case OVS_CT_ATTR_COMMIT:
			info->commit = true;
			break;
#ifdef CONFIG_NF_CONNTRACK_ZONES
		case OVS_CT_ATTR_ZONE:
			info->zone.id = nla_get_u16(a);
			break;
#endif
#ifdef CONFIG_NF_CONNTRACK_MARK
		case OVS_CT_ATTR_MARK: {
			struct md_mark *mark = nla_data(a);

			if (!mark->mask) {
				OVS_NLERR(log, "ct_mark mask cannot be 0");
				return -EINVAL;
			}
			info->mark = *mark;
			break;
		}
#endif
#ifdef CONFIG_NF_CONNTRACK_LABELS
		case OVS_CT_ATTR_LABELS: {
			struct md_labels *labels = nla_data(a);

			if (!labels_nonzero(&labels->mask)) {
				OVS_NLERR(log, "ct_labels mask cannot be 0");
				return -EINVAL;
			}
			info->labels = *labels;
			break;
		}
#endif
		case OVS_CT_ATTR_HELPER:
			*helper = nla_data(a);
			if (!memchr(*helper, '\0', nla_len(a))) {
				OVS_NLERR(log, "Invalid conntrack helper");
				return -EINVAL;
			}
			break;
#ifdef CONFIG_NF_NAT_NEEDED
		case OVS_CT_ATTR_NAT: {
			int err = parse_nat(a, info, log);

			if (err)
				return err;
			break;
		}
#endif
		default:
			OVS_NLERR(log, "Unknown conntrack attr (%d)",
				  type);
			return -EINVAL;
		}
	}

	if (rem > 0) {
		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
		return -EINVAL;
	}

	return 0;
}

bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
{
	if (attr == OVS_KEY_ATTR_CT_STATE)
		return true;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
	    attr == OVS_KEY_ATTR_CT_ZONE)
		return true;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
	    attr == OVS_KEY_ATTR_CT_MARK)
		return true;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
	    attr == OVS_KEY_ATTR_CT_LABELS) {
		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

		return ovs_net->xt_label;
	}

	return false;
}

int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
		       const struct sw_flow_key *key,
		       struct sw_flow_actions **sfa,  bool log)
{
	struct ovs_conntrack_info ct_info;
	const char *helper = NULL;
	u16 family;
	int err;

	family = key_to_nfproto(key);
	if (family == NFPROTO_UNSPEC) {
		OVS_NLERR(log, "ct family unspecified");
		return -EINVAL;
	}

	memset(&ct_info, 0, sizeof(ct_info));
	ct_info.family = family;

	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
			NF_CT_DEFAULT_ZONE_DIR, 0);

	err = parse_ct(attr, &ct_info, &helper, log);
	if (err)
		return err;

	/* Set up template for tracking connections in specific zones. */
	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
	if (!ct_info.ct) {
		OVS_NLERR(log, "Failed to allocate conntrack template");
		return -ENOMEM;
	}

	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
	nf_conntrack_get(&ct_info.ct->ct_general);

	if (helper) {
		err = ovs_ct_add_helper(&ct_info, helper, key, log);
		if (err)
			goto err_free_ct;
	}

	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
				 sizeof(ct_info), log);
	if (err)
		goto err_free_ct;

	return 0;
err_free_ct:
	__ovs_ct_free_action(&ct_info);
	return err;
}

#ifdef CONFIG_NF_NAT_NEEDED
static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
			       struct sk_buff *skb)
{
	struct nlattr *start;

	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
	if (!start)
		return false;

	if (info->nat & OVS_CT_SRC_NAT) {
		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
			return false;
	} else if (info->nat & OVS_CT_DST_NAT) {
		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
			return false;
	} else {
		goto out;
	}

	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
		    info->family == NFPROTO_IPV4) {
			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
					    info->range.min_addr.ip) ||
			    (info->range.max_addr.ip
			     != info->range.min_addr.ip &&
			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
					      info->range.max_addr.ip))))
				return false;
		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
			   info->family == NFPROTO_IPV6) {
			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
					     &info->range.min_addr.in6) ||
			    (memcmp(&info->range.max_addr.in6,
				    &info->range.min_addr.in6,
				    sizeof(info->range.max_addr.in6)) &&
			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
					       &info->range.max_addr.in6))))
				return false;
		} else {
			return false;
		}
	}
	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
			 ntohs(info->range.min_proto.all)) ||
	     (info->range.max_proto.all != info->range.min_proto.all &&
	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
			  ntohs(info->range.max_proto.all)))))
		return false;

	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
		return false;
	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
		return false;
	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
		return false;
out:
	nla_nest_end(skb, start);

	return true;
}
#endif

int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
			  struct sk_buff *skb)
{
	struct nlattr *start;

	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
	if (!start)
		return -EMSGSIZE;

	if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
		return -EMSGSIZE;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
		return -EMSGSIZE;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
		    &ct_info->mark))
		return -EMSGSIZE;
	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
	    labels_nonzero(&ct_info->labels.mask) &&
	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
		    &ct_info->labels))
		return -EMSGSIZE;
	if (ct_info->helper) {
		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
				   ct_info->helper->name))
			return -EMSGSIZE;
	}
#ifdef CONFIG_NF_NAT_NEEDED
	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
		return -EMSGSIZE;
#endif
	nla_nest_end(skb, start);

	return 0;
}

void ovs_ct_free_action(const struct nlattr *a)
{
	struct ovs_conntrack_info *ct_info = nla_data(a);

	__ovs_ct_free_action(ct_info);
}

static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
{
	if (ct_info->helper)
		module_put(ct_info->helper->me);
	if (ct_info->ct)
		nf_ct_put(ct_info->ct);
}

void ovs_ct_init(struct net *net)
{
	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

	if (nf_connlabels_get(net, n_bits - 1)) {
		ovs_net->xt_label = false;
		OVS_NLERR(true, "Failed to set connlabel length");
	} else {
		ovs_net->xt_label = true;
	}
}

void ovs_ct_exit(struct net *net)
{
	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);

	if (ovs_net->xt_label)
		nf_connlabels_put(net);
}