xref: /linux/net/openvswitch/conntrack.c (revision cc622420798c4bcf093785d872525087a7798db9)
1 /*
2  * Copyright (c) 2015 Nicira, Inc.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of version 2 of the GNU General Public
6  * License as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11  * General Public License for more details.
12  */
13 
14 #include <linux/module.h>
15 #include <linux/openvswitch.h>
16 #include <linux/tcp.h>
17 #include <linux/udp.h>
18 #include <linux/sctp.h>
19 #include <net/ip.h>
20 #include <net/netfilter/nf_conntrack_core.h>
21 #include <net/netfilter/nf_conntrack_helper.h>
22 #include <net/netfilter/nf_conntrack_labels.h>
23 #include <net/netfilter/nf_conntrack_seqadj.h>
24 #include <net/netfilter/nf_conntrack_zones.h>
25 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
26 
27 #ifdef CONFIG_NF_NAT_NEEDED
28 #include <linux/netfilter/nf_nat.h>
29 #include <net/netfilter/nf_nat_core.h>
30 #include <net/netfilter/nf_nat_l3proto.h>
31 #endif
32 
33 #include "datapath.h"
34 #include "conntrack.h"
35 #include "flow.h"
36 #include "flow_netlink.h"
37 
38 struct ovs_ct_len_tbl {
39 	int maxlen;
40 	int minlen;
41 };
42 
43 /* Metadata mark for masked write to conntrack mark */
44 struct md_mark {
45 	u32 value;
46 	u32 mask;
47 };
48 
49 /* Metadata label for masked write to conntrack label. */
50 struct md_labels {
51 	struct ovs_key_ct_labels value;
52 	struct ovs_key_ct_labels mask;
53 };
54 
55 enum ovs_ct_nat {
56 	OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
57 	OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
58 	OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
59 };
60 
61 /* Conntrack action context for execution. */
62 struct ovs_conntrack_info {
63 	struct nf_conntrack_helper *helper;
64 	struct nf_conntrack_zone zone;
65 	struct nf_conn *ct;
66 	u8 commit : 1;
67 	u8 nat : 3;                 /* enum ovs_ct_nat */
68 	u16 family;
69 	struct md_mark mark;
70 	struct md_labels labels;
71 #ifdef CONFIG_NF_NAT_NEEDED
72 	struct nf_nat_range range;  /* Only present for SRC NAT and DST NAT. */
73 #endif
74 };
75 
76 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
77 
78 static u16 key_to_nfproto(const struct sw_flow_key *key)
79 {
80 	switch (ntohs(key->eth.type)) {
81 	case ETH_P_IP:
82 		return NFPROTO_IPV4;
83 	case ETH_P_IPV6:
84 		return NFPROTO_IPV6;
85 	default:
86 		return NFPROTO_UNSPEC;
87 	}
88 }
89 
90 /* Map SKB connection state into the values used by flow definition. */
91 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
92 {
93 	u8 ct_state = OVS_CS_F_TRACKED;
94 
95 	switch (ctinfo) {
96 	case IP_CT_ESTABLISHED_REPLY:
97 	case IP_CT_RELATED_REPLY:
98 		ct_state |= OVS_CS_F_REPLY_DIR;
99 		break;
100 	default:
101 		break;
102 	}
103 
104 	switch (ctinfo) {
105 	case IP_CT_ESTABLISHED:
106 	case IP_CT_ESTABLISHED_REPLY:
107 		ct_state |= OVS_CS_F_ESTABLISHED;
108 		break;
109 	case IP_CT_RELATED:
110 	case IP_CT_RELATED_REPLY:
111 		ct_state |= OVS_CS_F_RELATED;
112 		break;
113 	case IP_CT_NEW:
114 		ct_state |= OVS_CS_F_NEW;
115 		break;
116 	default:
117 		break;
118 	}
119 
120 	return ct_state;
121 }
122 
123 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
124 {
125 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
126 	return ct ? ct->mark : 0;
127 #else
128 	return 0;
129 #endif
130 }
131 
132 static void ovs_ct_get_labels(const struct nf_conn *ct,
133 			      struct ovs_key_ct_labels *labels)
134 {
135 	struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
136 
137 	if (cl) {
138 		size_t len = cl->words * sizeof(long);
139 
140 		if (len > OVS_CT_LABELS_LEN)
141 			len = OVS_CT_LABELS_LEN;
142 		else if (len < OVS_CT_LABELS_LEN)
143 			memset(labels, 0, OVS_CT_LABELS_LEN);
144 		memcpy(labels, cl->bits, len);
145 	} else {
146 		memset(labels, 0, OVS_CT_LABELS_LEN);
147 	}
148 }
149 
150 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
151 				const struct nf_conntrack_zone *zone,
152 				const struct nf_conn *ct)
153 {
154 	key->ct.state = state;
155 	key->ct.zone = zone->id;
156 	key->ct.mark = ovs_ct_get_mark(ct);
157 	ovs_ct_get_labels(ct, &key->ct.labels);
158 }
159 
160 /* Update 'key' based on skb->nfct.  If 'post_ct' is true, then OVS has
161  * previously sent the packet to conntrack via the ct action.  If
162  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
163  * initialized from the connection status.
164  */
165 static void ovs_ct_update_key(const struct sk_buff *skb,
166 			      const struct ovs_conntrack_info *info,
167 			      struct sw_flow_key *key, bool post_ct,
168 			      bool keep_nat_flags)
169 {
170 	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
171 	enum ip_conntrack_info ctinfo;
172 	struct nf_conn *ct;
173 	u8 state = 0;
174 
175 	ct = nf_ct_get(skb, &ctinfo);
176 	if (ct) {
177 		state = ovs_ct_get_state(ctinfo);
178 		/* All unconfirmed entries are NEW connections. */
179 		if (!nf_ct_is_confirmed(ct))
180 			state |= OVS_CS_F_NEW;
181 		/* OVS persists the related flag for the duration of the
182 		 * connection.
183 		 */
184 		if (ct->master)
185 			state |= OVS_CS_F_RELATED;
186 		if (keep_nat_flags) {
187 			state |= key->ct.state & OVS_CS_F_NAT_MASK;
188 		} else {
189 			if (ct->status & IPS_SRC_NAT)
190 				state |= OVS_CS_F_SRC_NAT;
191 			if (ct->status & IPS_DST_NAT)
192 				state |= OVS_CS_F_DST_NAT;
193 		}
194 		zone = nf_ct_zone(ct);
195 	} else if (post_ct) {
196 		state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
197 		if (info)
198 			zone = &info->zone;
199 	}
200 	__ovs_ct_update_key(key, state, zone, ct);
201 }
202 
203 /* This is called to initialize CT key fields possibly coming in from the local
204  * stack.
205  */
206 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
207 {
208 	ovs_ct_update_key(skb, NULL, key, false, false);
209 }
210 
211 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
212 {
213 	if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
214 		return -EMSGSIZE;
215 
216 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
217 	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
218 		return -EMSGSIZE;
219 
220 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
221 	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
222 		return -EMSGSIZE;
223 
224 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
225 	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
226 		    &key->ct.labels))
227 		return -EMSGSIZE;
228 
229 	return 0;
230 }
231 
232 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
233 			   u32 ct_mark, u32 mask)
234 {
235 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
236 	enum ip_conntrack_info ctinfo;
237 	struct nf_conn *ct;
238 	u32 new_mark;
239 
240 	/* The connection could be invalid, in which case set_mark is no-op. */
241 	ct = nf_ct_get(skb, &ctinfo);
242 	if (!ct)
243 		return 0;
244 
245 	new_mark = ct_mark | (ct->mark & ~(mask));
246 	if (ct->mark != new_mark) {
247 		ct->mark = new_mark;
248 		nf_conntrack_event_cache(IPCT_MARK, ct);
249 		key->ct.mark = new_mark;
250 	}
251 
252 	return 0;
253 #else
254 	return -ENOTSUPP;
255 #endif
256 }
257 
258 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
259 			     const struct ovs_key_ct_labels *labels,
260 			     const struct ovs_key_ct_labels *mask)
261 {
262 	enum ip_conntrack_info ctinfo;
263 	struct nf_conn_labels *cl;
264 	struct nf_conn *ct;
265 	int err;
266 
267 	/* The connection could be invalid, in which case set_label is no-op.*/
268 	ct = nf_ct_get(skb, &ctinfo);
269 	if (!ct)
270 		return 0;
271 
272 	cl = nf_ct_labels_find(ct);
273 	if (!cl) {
274 		nf_ct_labels_ext_add(ct);
275 		cl = nf_ct_labels_find(ct);
276 	}
277 	if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
278 		return -ENOSPC;
279 
280 	err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
281 				    OVS_CT_LABELS_LEN / sizeof(u32));
282 	if (err)
283 		return err;
284 
285 	ovs_ct_get_labels(ct, &key->ct.labels);
286 	return 0;
287 }
288 
289 /* 'skb' should already be pulled to nh_ofs. */
290 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
291 {
292 	const struct nf_conntrack_helper *helper;
293 	const struct nf_conn_help *help;
294 	enum ip_conntrack_info ctinfo;
295 	unsigned int protoff;
296 	struct nf_conn *ct;
297 	int err;
298 
299 	ct = nf_ct_get(skb, &ctinfo);
300 	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
301 		return NF_ACCEPT;
302 
303 	help = nfct_help(ct);
304 	if (!help)
305 		return NF_ACCEPT;
306 
307 	helper = rcu_dereference(help->helper);
308 	if (!helper)
309 		return NF_ACCEPT;
310 
311 	switch (proto) {
312 	case NFPROTO_IPV4:
313 		protoff = ip_hdrlen(skb);
314 		break;
315 	case NFPROTO_IPV6: {
316 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
317 		__be16 frag_off;
318 		int ofs;
319 
320 		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
321 				       &frag_off);
322 		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
323 			pr_debug("proto header not found\n");
324 			return NF_ACCEPT;
325 		}
326 		protoff = ofs;
327 		break;
328 	}
329 	default:
330 		WARN_ONCE(1, "helper invoked on non-IP family!");
331 		return NF_DROP;
332 	}
333 
334 	err = helper->help(skb, protoff, ct, ctinfo);
335 	if (err != NF_ACCEPT)
336 		return err;
337 
338 	/* Adjust seqs after helper.  This is needed due to some helpers (e.g.,
339 	 * FTP with NAT) adusting the TCP payload size when mangling IP
340 	 * addresses and/or port numbers in the text-based control connection.
341 	 */
342 	if (test_bit(IPS_SEQ_ADJUST_BIT, &ct->status) &&
343 	    !nf_ct_seq_adjust(skb, ct, ctinfo, protoff))
344 		return NF_DROP;
345 	return NF_ACCEPT;
346 }
347 
348 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
349  * value if 'skb' is freed.
350  */
351 static int handle_fragments(struct net *net, struct sw_flow_key *key,
352 			    u16 zone, struct sk_buff *skb)
353 {
354 	struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
355 	int err;
356 
357 	if (key->eth.type == htons(ETH_P_IP)) {
358 		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
359 
360 		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
361 		err = ip_defrag(net, skb, user);
362 		if (err)
363 			return err;
364 
365 		ovs_cb.mru = IPCB(skb)->frag_max_size;
366 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
367 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
368 		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
369 
370 		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
371 		err = nf_ct_frag6_gather(net, skb, user);
372 		if (err)
373 			return err;
374 
375 		key->ip.proto = ipv6_hdr(skb)->nexthdr;
376 		ovs_cb.mru = IP6CB(skb)->frag_max_size;
377 #endif
378 	} else {
379 		kfree_skb(skb);
380 		return -EPFNOSUPPORT;
381 	}
382 
383 	key->ip.frag = OVS_FRAG_TYPE_NONE;
384 	skb_clear_hash(skb);
385 	skb->ignore_df = 1;
386 	*OVS_CB(skb) = ovs_cb;
387 
388 	return 0;
389 }
390 
391 static struct nf_conntrack_expect *
392 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
393 		   u16 proto, const struct sk_buff *skb)
394 {
395 	struct nf_conntrack_tuple tuple;
396 
397 	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
398 		return NULL;
399 	return __nf_ct_expect_find(net, zone, &tuple);
400 }
401 
402 /* This replicates logic from nf_conntrack_core.c that is not exported. */
403 static enum ip_conntrack_info
404 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
405 {
406 	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
407 
408 	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
409 		return IP_CT_ESTABLISHED_REPLY;
410 	/* Once we've had two way comms, always ESTABLISHED. */
411 	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
412 		return IP_CT_ESTABLISHED;
413 	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
414 		return IP_CT_RELATED;
415 	return IP_CT_NEW;
416 }
417 
418 /* Find an existing connection which this packet belongs to without
419  * re-attributing statistics or modifying the connection state.  This allows an
420  * skb->nfct lost due to an upcall to be recovered during actions execution.
421  *
422  * Must be called with rcu_read_lock.
423  *
424  * On success, populates skb->nfct and skb->nfctinfo, and returns the
425  * connection.  Returns NULL if there is no existing entry.
426  */
427 static struct nf_conn *
428 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
429 		     u8 l3num, struct sk_buff *skb)
430 {
431 	struct nf_conntrack_l3proto *l3proto;
432 	struct nf_conntrack_l4proto *l4proto;
433 	struct nf_conntrack_tuple tuple;
434 	struct nf_conntrack_tuple_hash *h;
435 	enum ip_conntrack_info ctinfo;
436 	struct nf_conn *ct;
437 	unsigned int dataoff;
438 	u8 protonum;
439 
440 	l3proto = __nf_ct_l3proto_find(l3num);
441 	if (!l3proto) {
442 		pr_debug("ovs_ct_find_existing: Can't get l3proto\n");
443 		return NULL;
444 	}
445 	if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
446 				 &protonum) <= 0) {
447 		pr_debug("ovs_ct_find_existing: Can't get protonum\n");
448 		return NULL;
449 	}
450 	l4proto = __nf_ct_l4proto_find(l3num, protonum);
451 	if (!l4proto) {
452 		pr_debug("ovs_ct_find_existing: Can't get l4proto\n");
453 		return NULL;
454 	}
455 	if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
456 			     protonum, net, &tuple, l3proto, l4proto)) {
457 		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
458 		return NULL;
459 	}
460 
461 	/* look for tuple match */
462 	h = nf_conntrack_find_get(net, zone, &tuple);
463 	if (!h)
464 		return NULL;   /* Not found. */
465 
466 	ct = nf_ct_tuplehash_to_ctrack(h);
467 
468 	ctinfo = ovs_ct_get_info(h);
469 	if (ctinfo == IP_CT_NEW) {
470 		/* This should not happen. */
471 		WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
472 	}
473 	skb->nfct = &ct->ct_general;
474 	skb->nfctinfo = ctinfo;
475 	return ct;
476 }
477 
478 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
479 static bool skb_nfct_cached(struct net *net,
480 			    const struct sw_flow_key *key,
481 			    const struct ovs_conntrack_info *info,
482 			    struct sk_buff *skb)
483 {
484 	enum ip_conntrack_info ctinfo;
485 	struct nf_conn *ct;
486 
487 	ct = nf_ct_get(skb, &ctinfo);
488 	/* If no ct, check if we have evidence that an existing conntrack entry
489 	 * might be found for this skb.  This happens when we lose a skb->nfct
490 	 * due to an upcall.  If the connection was not confirmed, it is not
491 	 * cached and needs to be run through conntrack again.
492 	 */
493 	if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
494 	    !(key->ct.state & OVS_CS_F_INVALID) &&
495 	    key->ct.zone == info->zone.id)
496 		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
497 	if (!ct)
498 		return false;
499 	if (!net_eq(net, read_pnet(&ct->ct_net)))
500 		return false;
501 	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
502 		return false;
503 	if (info->helper) {
504 		struct nf_conn_help *help;
505 
506 		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
507 		if (help && rcu_access_pointer(help->helper) != info->helper)
508 			return false;
509 	}
510 
511 	return true;
512 }
513 
514 #ifdef CONFIG_NF_NAT_NEEDED
515 /* Modelled after nf_nat_ipv[46]_fn().
516  * range is only used for new, uninitialized NAT state.
517  * Returns either NF_ACCEPT or NF_DROP.
518  */
519 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
520 			      enum ip_conntrack_info ctinfo,
521 			      const struct nf_nat_range *range,
522 			      enum nf_nat_manip_type maniptype)
523 {
524 	int hooknum, nh_off, err = NF_ACCEPT;
525 
526 	nh_off = skb_network_offset(skb);
527 	skb_pull(skb, nh_off);
528 
529 	/* See HOOK2MANIP(). */
530 	if (maniptype == NF_NAT_MANIP_SRC)
531 		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
532 	else
533 		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
534 
535 	switch (ctinfo) {
536 	case IP_CT_RELATED:
537 	case IP_CT_RELATED_REPLY:
538 		if (skb->protocol == htons(ETH_P_IP) &&
539 		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
540 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
541 							   hooknum))
542 				err = NF_DROP;
543 			goto push;
544 #if IS_ENABLED(CONFIG_NF_NAT_IPV6)
545 		} else if (skb->protocol == htons(ETH_P_IPV6)) {
546 			__be16 frag_off;
547 			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
548 			int hdrlen = ipv6_skip_exthdr(skb,
549 						      sizeof(struct ipv6hdr),
550 						      &nexthdr, &frag_off);
551 
552 			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
553 				if (!nf_nat_icmpv6_reply_translation(skb, ct,
554 								     ctinfo,
555 								     hooknum,
556 								     hdrlen))
557 					err = NF_DROP;
558 				goto push;
559 			}
560 #endif
561 		}
562 		/* Non-ICMP, fall thru to initialize if needed. */
563 	case IP_CT_NEW:
564 		/* Seen it before?  This can happen for loopback, retrans,
565 		 * or local packets.
566 		 */
567 		if (!nf_nat_initialized(ct, maniptype)) {
568 			/* Initialize according to the NAT action. */
569 			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
570 				/* Action is set up to establish a new
571 				 * mapping.
572 				 */
573 				? nf_nat_setup_info(ct, range, maniptype)
574 				: nf_nat_alloc_null_binding(ct, hooknum);
575 			if (err != NF_ACCEPT)
576 				goto push;
577 		}
578 		break;
579 
580 	case IP_CT_ESTABLISHED:
581 	case IP_CT_ESTABLISHED_REPLY:
582 		break;
583 
584 	default:
585 		err = NF_DROP;
586 		goto push;
587 	}
588 
589 	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
590 push:
591 	skb_push(skb, nh_off);
592 
593 	return err;
594 }
595 
596 static void ovs_nat_update_key(struct sw_flow_key *key,
597 			       const struct sk_buff *skb,
598 			       enum nf_nat_manip_type maniptype)
599 {
600 	if (maniptype == NF_NAT_MANIP_SRC) {
601 		__be16 src;
602 
603 		key->ct.state |= OVS_CS_F_SRC_NAT;
604 		if (key->eth.type == htons(ETH_P_IP))
605 			key->ipv4.addr.src = ip_hdr(skb)->saddr;
606 		else if (key->eth.type == htons(ETH_P_IPV6))
607 			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
608 			       sizeof(key->ipv6.addr.src));
609 		else
610 			return;
611 
612 		if (key->ip.proto == IPPROTO_UDP)
613 			src = udp_hdr(skb)->source;
614 		else if (key->ip.proto == IPPROTO_TCP)
615 			src = tcp_hdr(skb)->source;
616 		else if (key->ip.proto == IPPROTO_SCTP)
617 			src = sctp_hdr(skb)->source;
618 		else
619 			return;
620 
621 		key->tp.src = src;
622 	} else {
623 		__be16 dst;
624 
625 		key->ct.state |= OVS_CS_F_DST_NAT;
626 		if (key->eth.type == htons(ETH_P_IP))
627 			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
628 		else if (key->eth.type == htons(ETH_P_IPV6))
629 			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
630 			       sizeof(key->ipv6.addr.dst));
631 		else
632 			return;
633 
634 		if (key->ip.proto == IPPROTO_UDP)
635 			dst = udp_hdr(skb)->dest;
636 		else if (key->ip.proto == IPPROTO_TCP)
637 			dst = tcp_hdr(skb)->dest;
638 		else if (key->ip.proto == IPPROTO_SCTP)
639 			dst = sctp_hdr(skb)->dest;
640 		else
641 			return;
642 
643 		key->tp.dst = dst;
644 	}
645 }
646 
647 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
648 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
649 		      const struct ovs_conntrack_info *info,
650 		      struct sk_buff *skb, struct nf_conn *ct,
651 		      enum ip_conntrack_info ctinfo)
652 {
653 	enum nf_nat_manip_type maniptype;
654 	int err;
655 
656 	if (nf_ct_is_untracked(ct)) {
657 		/* A NAT action may only be performed on tracked packets. */
658 		return NF_ACCEPT;
659 	}
660 
661 	/* Add NAT extension if not confirmed yet. */
662 	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
663 		return NF_ACCEPT;   /* Can't NAT. */
664 
665 	/* Determine NAT type.
666 	 * Check if the NAT type can be deduced from the tracked connection.
667 	 * Make sure expected traffic is NATted only when committing.
668 	 */
669 	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
670 	    ct->status & IPS_NAT_MASK &&
671 	    (!(ct->status & IPS_EXPECTED_BIT) || info->commit)) {
672 		/* NAT an established or related connection like before. */
673 		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
674 			/* This is the REPLY direction for a connection
675 			 * for which NAT was applied in the forward
676 			 * direction.  Do the reverse NAT.
677 			 */
678 			maniptype = ct->status & IPS_SRC_NAT
679 				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
680 		else
681 			maniptype = ct->status & IPS_SRC_NAT
682 				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
683 	} else if (info->nat & OVS_CT_SRC_NAT) {
684 		maniptype = NF_NAT_MANIP_SRC;
685 	} else if (info->nat & OVS_CT_DST_NAT) {
686 		maniptype = NF_NAT_MANIP_DST;
687 	} else {
688 		return NF_ACCEPT; /* Connection is not NATed. */
689 	}
690 	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
691 
692 	/* Mark NAT done if successful and update the flow key. */
693 	if (err == NF_ACCEPT)
694 		ovs_nat_update_key(key, skb, maniptype);
695 
696 	return err;
697 }
698 #else /* !CONFIG_NF_NAT_NEEDED */
699 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
700 		      const struct ovs_conntrack_info *info,
701 		      struct sk_buff *skb, struct nf_conn *ct,
702 		      enum ip_conntrack_info ctinfo)
703 {
704 	return NF_ACCEPT;
705 }
706 #endif
707 
708 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
709  * not done already.  Update key with new CT state after passing the packet
710  * through conntrack.
711  * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
712  * set to NULL and 0 will be returned.
713  */
714 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
715 			   const struct ovs_conntrack_info *info,
716 			   struct sk_buff *skb)
717 {
718 	/* If we are recirculating packets to match on conntrack fields and
719 	 * committing with a separate conntrack action,  then we don't need to
720 	 * actually run the packet through conntrack twice unless it's for a
721 	 * different zone.
722 	 */
723 	bool cached = skb_nfct_cached(net, key, info, skb);
724 	enum ip_conntrack_info ctinfo;
725 	struct nf_conn *ct;
726 
727 	if (!cached) {
728 		struct nf_conn *tmpl = info->ct;
729 		int err;
730 
731 		/* Associate skb with specified zone. */
732 		if (tmpl) {
733 			if (skb->nfct)
734 				nf_conntrack_put(skb->nfct);
735 			nf_conntrack_get(&tmpl->ct_general);
736 			skb->nfct = &tmpl->ct_general;
737 			skb->nfctinfo = IP_CT_NEW;
738 		}
739 
740 		/* Repeat if requested, see nf_iterate(). */
741 		do {
742 			err = nf_conntrack_in(net, info->family,
743 					      NF_INET_PRE_ROUTING, skb);
744 		} while (err == NF_REPEAT);
745 
746 		if (err != NF_ACCEPT)
747 			return -ENOENT;
748 
749 		/* Clear CT state NAT flags to mark that we have not yet done
750 		 * NAT after the nf_conntrack_in() call.  We can actually clear
751 		 * the whole state, as it will be re-initialized below.
752 		 */
753 		key->ct.state = 0;
754 
755 		/* Update the key, but keep the NAT flags. */
756 		ovs_ct_update_key(skb, info, key, true, true);
757 	}
758 
759 	ct = nf_ct_get(skb, &ctinfo);
760 	if (ct) {
761 		/* Packets starting a new connection must be NATted before the
762 		 * helper, so that the helper knows about the NAT.  We enforce
763 		 * this by delaying both NAT and helper calls for unconfirmed
764 		 * connections until the committing CT action.  For later
765 		 * packets NAT and Helper may be called in either order.
766 		 *
767 		 * NAT will be done only if the CT action has NAT, and only
768 		 * once per packet (per zone), as guarded by the NAT bits in
769 		 * the key->ct.state.
770 		 */
771 		if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
772 		    (nf_ct_is_confirmed(ct) || info->commit) &&
773 		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
774 			return -EINVAL;
775 		}
776 
777 		/* Call the helper only if:
778 		 * - nf_conntrack_in() was executed above ("!cached") for a
779 		 *   confirmed connection, or
780 		 * - When committing an unconfirmed connection.
781 		 */
782 		if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
783 		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
784 			return -EINVAL;
785 		}
786 	}
787 
788 	return 0;
789 }
790 
791 /* Lookup connection and read fields into key. */
792 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
793 			 const struct ovs_conntrack_info *info,
794 			 struct sk_buff *skb)
795 {
796 	struct nf_conntrack_expect *exp;
797 
798 	/* If we pass an expected packet through nf_conntrack_in() the
799 	 * expectation is typically removed, but the packet could still be
800 	 * lost in upcall processing.  To prevent this from happening we
801 	 * perform an explicit expectation lookup.  Expected connections are
802 	 * always new, and will be passed through conntrack only when they are
803 	 * committed, as it is OK to remove the expectation at that time.
804 	 */
805 	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
806 	if (exp) {
807 		u8 state;
808 
809 		/* NOTE: New connections are NATted and Helped only when
810 		 * committed, so we are not calling into NAT here.
811 		 */
812 		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
813 		__ovs_ct_update_key(key, state, &info->zone, exp->master);
814 	} else
815 		return __ovs_ct_lookup(net, key, info, skb);
816 
817 	return 0;
818 }
819 
820 /* Lookup connection and confirm if unconfirmed. */
821 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
822 			 const struct ovs_conntrack_info *info,
823 			 struct sk_buff *skb)
824 {
825 	int err;
826 
827 	err = __ovs_ct_lookup(net, key, info, skb);
828 	if (err)
829 		return err;
830 	/* This is a no-op if the connection has already been confirmed. */
831 	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
832 		return -EINVAL;
833 
834 	return 0;
835 }
836 
837 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
838 {
839 	size_t i;
840 
841 	for (i = 0; i < sizeof(*labels); i++)
842 		if (labels->ct_labels[i])
843 			return true;
844 
845 	return false;
846 }
847 
848 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
849  * value if 'skb' is freed.
850  */
851 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
852 		   struct sw_flow_key *key,
853 		   const struct ovs_conntrack_info *info)
854 {
855 	int nh_ofs;
856 	int err;
857 
858 	/* The conntrack module expects to be working at L3. */
859 	nh_ofs = skb_network_offset(skb);
860 	skb_pull(skb, nh_ofs);
861 
862 	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
863 		err = handle_fragments(net, key, info->zone.id, skb);
864 		if (err)
865 			return err;
866 	}
867 
868 	if (info->commit)
869 		err = ovs_ct_commit(net, key, info, skb);
870 	else
871 		err = ovs_ct_lookup(net, key, info, skb);
872 	if (err)
873 		goto err;
874 
875 	if (info->mark.mask) {
876 		err = ovs_ct_set_mark(skb, key, info->mark.value,
877 				      info->mark.mask);
878 		if (err)
879 			goto err;
880 	}
881 	if (labels_nonzero(&info->labels.mask))
882 		err = ovs_ct_set_labels(skb, key, &info->labels.value,
883 					&info->labels.mask);
884 err:
885 	skb_push(skb, nh_ofs);
886 	if (err)
887 		kfree_skb(skb);
888 	return err;
889 }
890 
891 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
892 			     const struct sw_flow_key *key, bool log)
893 {
894 	struct nf_conntrack_helper *helper;
895 	struct nf_conn_help *help;
896 
897 	helper = nf_conntrack_helper_try_module_get(name, info->family,
898 						    key->ip.proto);
899 	if (!helper) {
900 		OVS_NLERR(log, "Unknown helper \"%s\"", name);
901 		return -EINVAL;
902 	}
903 
904 	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
905 	if (!help) {
906 		module_put(helper->me);
907 		return -ENOMEM;
908 	}
909 
910 	rcu_assign_pointer(help->helper, helper);
911 	info->helper = helper;
912 	return 0;
913 }
914 
915 #ifdef CONFIG_NF_NAT_NEEDED
916 static int parse_nat(const struct nlattr *attr,
917 		     struct ovs_conntrack_info *info, bool log)
918 {
919 	struct nlattr *a;
920 	int rem;
921 	bool have_ip_max = false;
922 	bool have_proto_max = false;
923 	bool ip_vers = (info->family == NFPROTO_IPV6);
924 
925 	nla_for_each_nested(a, attr, rem) {
926 		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
927 			[OVS_NAT_ATTR_SRC] = {0, 0},
928 			[OVS_NAT_ATTR_DST] = {0, 0},
929 			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
930 						 sizeof(struct in6_addr)},
931 			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
932 						 sizeof(struct in6_addr)},
933 			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
934 			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
935 			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
936 			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
937 			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
938 		};
939 		int type = nla_type(a);
940 
941 		if (type > OVS_NAT_ATTR_MAX) {
942 			OVS_NLERR(log,
943 				  "Unknown NAT attribute (type=%d, max=%d).\n",
944 				  type, OVS_NAT_ATTR_MAX);
945 			return -EINVAL;
946 		}
947 
948 		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
949 			OVS_NLERR(log,
950 				  "NAT attribute type %d has unexpected length (%d != %d).\n",
951 				  type, nla_len(a),
952 				  ovs_nat_attr_lens[type][ip_vers]);
953 			return -EINVAL;
954 		}
955 
956 		switch (type) {
957 		case OVS_NAT_ATTR_SRC:
958 		case OVS_NAT_ATTR_DST:
959 			if (info->nat) {
960 				OVS_NLERR(log,
961 					  "Only one type of NAT may be specified.\n"
962 					  );
963 				return -ERANGE;
964 			}
965 			info->nat |= OVS_CT_NAT;
966 			info->nat |= ((type == OVS_NAT_ATTR_SRC)
967 					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
968 			break;
969 
970 		case OVS_NAT_ATTR_IP_MIN:
971 			nla_memcpy(&info->range.min_addr, a, nla_len(a));
972 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
973 			break;
974 
975 		case OVS_NAT_ATTR_IP_MAX:
976 			have_ip_max = true;
977 			nla_memcpy(&info->range.max_addr, a,
978 				   sizeof(info->range.max_addr));
979 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
980 			break;
981 
982 		case OVS_NAT_ATTR_PROTO_MIN:
983 			info->range.min_proto.all = htons(nla_get_u16(a));
984 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
985 			break;
986 
987 		case OVS_NAT_ATTR_PROTO_MAX:
988 			have_proto_max = true;
989 			info->range.max_proto.all = htons(nla_get_u16(a));
990 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
991 			break;
992 
993 		case OVS_NAT_ATTR_PERSISTENT:
994 			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
995 			break;
996 
997 		case OVS_NAT_ATTR_PROTO_HASH:
998 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
999 			break;
1000 
1001 		case OVS_NAT_ATTR_PROTO_RANDOM:
1002 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1003 			break;
1004 
1005 		default:
1006 			OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
1007 			return -EINVAL;
1008 		}
1009 	}
1010 
1011 	if (rem > 0) {
1012 		OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
1013 		return -EINVAL;
1014 	}
1015 	if (!info->nat) {
1016 		/* Do not allow flags if no type is given. */
1017 		if (info->range.flags) {
1018 			OVS_NLERR(log,
1019 				  "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
1020 				  );
1021 			return -EINVAL;
1022 		}
1023 		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1024 	} else if (!info->commit) {
1025 		OVS_NLERR(log,
1026 			  "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
1027 			  );
1028 		return -EINVAL;
1029 	}
1030 	/* Allow missing IP_MAX. */
1031 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1032 		memcpy(&info->range.max_addr, &info->range.min_addr,
1033 		       sizeof(info->range.max_addr));
1034 	}
1035 	/* Allow missing PROTO_MAX. */
1036 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1037 	    !have_proto_max) {
1038 		info->range.max_proto.all = info->range.min_proto.all;
1039 	}
1040 	return 0;
1041 }
1042 #endif
1043 
1044 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1045 	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1046 	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
1047 				    .maxlen = sizeof(u16) },
1048 	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
1049 				    .maxlen = sizeof(struct md_mark) },
1050 	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
1051 				    .maxlen = sizeof(struct md_labels) },
1052 	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
1053 				    .maxlen = NF_CT_HELPER_NAME_LEN },
1054 #ifdef CONFIG_NF_NAT_NEEDED
1055 	/* NAT length is checked when parsing the nested attributes. */
1056 	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
1057 #endif
1058 };
1059 
1060 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1061 		    const char **helper, bool log)
1062 {
1063 	struct nlattr *a;
1064 	int rem;
1065 
1066 	nla_for_each_nested(a, attr, rem) {
1067 		int type = nla_type(a);
1068 		int maxlen = ovs_ct_attr_lens[type].maxlen;
1069 		int minlen = ovs_ct_attr_lens[type].minlen;
1070 
1071 		if (type > OVS_CT_ATTR_MAX) {
1072 			OVS_NLERR(log,
1073 				  "Unknown conntrack attr (type=%d, max=%d)",
1074 				  type, OVS_CT_ATTR_MAX);
1075 			return -EINVAL;
1076 		}
1077 		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1078 			OVS_NLERR(log,
1079 				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1080 				  type, nla_len(a), maxlen);
1081 			return -EINVAL;
1082 		}
1083 
1084 		switch (type) {
1085 		case OVS_CT_ATTR_COMMIT:
1086 			info->commit = true;
1087 			break;
1088 #ifdef CONFIG_NF_CONNTRACK_ZONES
1089 		case OVS_CT_ATTR_ZONE:
1090 			info->zone.id = nla_get_u16(a);
1091 			break;
1092 #endif
1093 #ifdef CONFIG_NF_CONNTRACK_MARK
1094 		case OVS_CT_ATTR_MARK: {
1095 			struct md_mark *mark = nla_data(a);
1096 
1097 			if (!mark->mask) {
1098 				OVS_NLERR(log, "ct_mark mask cannot be 0");
1099 				return -EINVAL;
1100 			}
1101 			info->mark = *mark;
1102 			break;
1103 		}
1104 #endif
1105 #ifdef CONFIG_NF_CONNTRACK_LABELS
1106 		case OVS_CT_ATTR_LABELS: {
1107 			struct md_labels *labels = nla_data(a);
1108 
1109 			if (!labels_nonzero(&labels->mask)) {
1110 				OVS_NLERR(log, "ct_labels mask cannot be 0");
1111 				return -EINVAL;
1112 			}
1113 			info->labels = *labels;
1114 			break;
1115 		}
1116 #endif
1117 		case OVS_CT_ATTR_HELPER:
1118 			*helper = nla_data(a);
1119 			if (!memchr(*helper, '\0', nla_len(a))) {
1120 				OVS_NLERR(log, "Invalid conntrack helper");
1121 				return -EINVAL;
1122 			}
1123 			break;
1124 #ifdef CONFIG_NF_NAT_NEEDED
1125 		case OVS_CT_ATTR_NAT: {
1126 			int err = parse_nat(a, info, log);
1127 
1128 			if (err)
1129 				return err;
1130 			break;
1131 		}
1132 #endif
1133 		default:
1134 			OVS_NLERR(log, "Unknown conntrack attr (%d)",
1135 				  type);
1136 			return -EINVAL;
1137 		}
1138 	}
1139 
1140 	if (rem > 0) {
1141 		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1142 		return -EINVAL;
1143 	}
1144 
1145 	return 0;
1146 }
1147 
1148 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1149 {
1150 	if (attr == OVS_KEY_ATTR_CT_STATE)
1151 		return true;
1152 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1153 	    attr == OVS_KEY_ATTR_CT_ZONE)
1154 		return true;
1155 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1156 	    attr == OVS_KEY_ATTR_CT_MARK)
1157 		return true;
1158 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1159 	    attr == OVS_KEY_ATTR_CT_LABELS) {
1160 		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1161 
1162 		return ovs_net->xt_label;
1163 	}
1164 
1165 	return false;
1166 }
1167 
1168 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1169 		       const struct sw_flow_key *key,
1170 		       struct sw_flow_actions **sfa,  bool log)
1171 {
1172 	struct ovs_conntrack_info ct_info;
1173 	const char *helper = NULL;
1174 	u16 family;
1175 	int err;
1176 
1177 	family = key_to_nfproto(key);
1178 	if (family == NFPROTO_UNSPEC) {
1179 		OVS_NLERR(log, "ct family unspecified");
1180 		return -EINVAL;
1181 	}
1182 
1183 	memset(&ct_info, 0, sizeof(ct_info));
1184 	ct_info.family = family;
1185 
1186 	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1187 			NF_CT_DEFAULT_ZONE_DIR, 0);
1188 
1189 	err = parse_ct(attr, &ct_info, &helper, log);
1190 	if (err)
1191 		return err;
1192 
1193 	/* Set up template for tracking connections in specific zones. */
1194 	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1195 	if (!ct_info.ct) {
1196 		OVS_NLERR(log, "Failed to allocate conntrack template");
1197 		return -ENOMEM;
1198 	}
1199 
1200 	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1201 	nf_conntrack_get(&ct_info.ct->ct_general);
1202 
1203 	if (helper) {
1204 		err = ovs_ct_add_helper(&ct_info, helper, key, log);
1205 		if (err)
1206 			goto err_free_ct;
1207 	}
1208 
1209 	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1210 				 sizeof(ct_info), log);
1211 	if (err)
1212 		goto err_free_ct;
1213 
1214 	return 0;
1215 err_free_ct:
1216 	__ovs_ct_free_action(&ct_info);
1217 	return err;
1218 }
1219 
1220 #ifdef CONFIG_NF_NAT_NEEDED
1221 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1222 			       struct sk_buff *skb)
1223 {
1224 	struct nlattr *start;
1225 
1226 	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1227 	if (!start)
1228 		return false;
1229 
1230 	if (info->nat & OVS_CT_SRC_NAT) {
1231 		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1232 			return false;
1233 	} else if (info->nat & OVS_CT_DST_NAT) {
1234 		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1235 			return false;
1236 	} else {
1237 		goto out;
1238 	}
1239 
1240 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1241 		if (info->family == NFPROTO_IPV4) {
1242 			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1243 					    info->range.min_addr.ip) ||
1244 			    (info->range.max_addr.ip
1245 			     != info->range.min_addr.ip &&
1246 			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1247 					      info->range.max_addr.ip))))
1248 				return false;
1249 #if IS_ENABLED(CONFIG_NF_NAT_IPV6)
1250 		} else if (info->family == NFPROTO_IPV6) {
1251 			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1252 					     &info->range.min_addr.in6) ||
1253 			    (memcmp(&info->range.max_addr.in6,
1254 				    &info->range.min_addr.in6,
1255 				    sizeof(info->range.max_addr.in6)) &&
1256 			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1257 					       &info->range.max_addr.in6))))
1258 				return false;
1259 #endif
1260 		} else {
1261 			return false;
1262 		}
1263 	}
1264 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1265 	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1266 			 ntohs(info->range.min_proto.all)) ||
1267 	     (info->range.max_proto.all != info->range.min_proto.all &&
1268 	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1269 			  ntohs(info->range.max_proto.all)))))
1270 		return false;
1271 
1272 	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1273 	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1274 		return false;
1275 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1276 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1277 		return false;
1278 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1279 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1280 		return false;
1281 out:
1282 	nla_nest_end(skb, start);
1283 
1284 	return true;
1285 }
1286 #endif
1287 
1288 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1289 			  struct sk_buff *skb)
1290 {
1291 	struct nlattr *start;
1292 
1293 	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1294 	if (!start)
1295 		return -EMSGSIZE;
1296 
1297 	if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
1298 		return -EMSGSIZE;
1299 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1300 	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1301 		return -EMSGSIZE;
1302 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1303 	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1304 		    &ct_info->mark))
1305 		return -EMSGSIZE;
1306 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1307 	    labels_nonzero(&ct_info->labels.mask) &&
1308 	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1309 		    &ct_info->labels))
1310 		return -EMSGSIZE;
1311 	if (ct_info->helper) {
1312 		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1313 				   ct_info->helper->name))
1314 			return -EMSGSIZE;
1315 	}
1316 #ifdef CONFIG_NF_NAT_NEEDED
1317 	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1318 		return -EMSGSIZE;
1319 #endif
1320 	nla_nest_end(skb, start);
1321 
1322 	return 0;
1323 }
1324 
1325 void ovs_ct_free_action(const struct nlattr *a)
1326 {
1327 	struct ovs_conntrack_info *ct_info = nla_data(a);
1328 
1329 	__ovs_ct_free_action(ct_info);
1330 }
1331 
1332 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1333 {
1334 	if (ct_info->helper)
1335 		module_put(ct_info->helper->me);
1336 	if (ct_info->ct)
1337 		nf_ct_put(ct_info->ct);
1338 }
1339 
1340 void ovs_ct_init(struct net *net)
1341 {
1342 	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1343 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1344 
1345 	if (nf_connlabels_get(net, n_bits)) {
1346 		ovs_net->xt_label = false;
1347 		OVS_NLERR(true, "Failed to set connlabel length");
1348 	} else {
1349 		ovs_net->xt_label = true;
1350 	}
1351 }
1352 
1353 void ovs_ct_exit(struct net *net)
1354 {
1355 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1356 
1357 	if (ovs_net->xt_label)
1358 		nf_connlabels_put(net);
1359 }
1360