xref: /openbmc/linux/net/openvswitch/conntrack.c (revision 029f7f3b8701cc7aca8bdb31f0c7edd6a479e357)
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 <net/ip.h>
17 #include <net/netfilter/nf_conntrack_core.h>
18 #include <net/netfilter/nf_conntrack_helper.h>
19 #include <net/netfilter/nf_conntrack_labels.h>
20 #include <net/netfilter/nf_conntrack_zones.h>
21 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
22 
23 #include "datapath.h"
24 #include "conntrack.h"
25 #include "flow.h"
26 #include "flow_netlink.h"
27 
28 struct ovs_ct_len_tbl {
29 	size_t maxlen;
30 	size_t minlen;
31 };
32 
33 /* Metadata mark for masked write to conntrack mark */
34 struct md_mark {
35 	u32 value;
36 	u32 mask;
37 };
38 
39 /* Metadata label for masked write to conntrack label. */
40 struct md_labels {
41 	struct ovs_key_ct_labels value;
42 	struct ovs_key_ct_labels mask;
43 };
44 
45 /* Conntrack action context for execution. */
46 struct ovs_conntrack_info {
47 	struct nf_conntrack_helper *helper;
48 	struct nf_conntrack_zone zone;
49 	struct nf_conn *ct;
50 	u8 commit : 1;
51 	u16 family;
52 	struct md_mark mark;
53 	struct md_labels labels;
54 };
55 
56 static u16 key_to_nfproto(const struct sw_flow_key *key)
57 {
58 	switch (ntohs(key->eth.type)) {
59 	case ETH_P_IP:
60 		return NFPROTO_IPV4;
61 	case ETH_P_IPV6:
62 		return NFPROTO_IPV6;
63 	default:
64 		return NFPROTO_UNSPEC;
65 	}
66 }
67 
68 /* Map SKB connection state into the values used by flow definition. */
69 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
70 {
71 	u8 ct_state = OVS_CS_F_TRACKED;
72 
73 	switch (ctinfo) {
74 	case IP_CT_ESTABLISHED_REPLY:
75 	case IP_CT_RELATED_REPLY:
76 	case IP_CT_NEW_REPLY:
77 		ct_state |= OVS_CS_F_REPLY_DIR;
78 		break;
79 	default:
80 		break;
81 	}
82 
83 	switch (ctinfo) {
84 	case IP_CT_ESTABLISHED:
85 	case IP_CT_ESTABLISHED_REPLY:
86 		ct_state |= OVS_CS_F_ESTABLISHED;
87 		break;
88 	case IP_CT_RELATED:
89 	case IP_CT_RELATED_REPLY:
90 		ct_state |= OVS_CS_F_RELATED;
91 		break;
92 	case IP_CT_NEW:
93 	case IP_CT_NEW_REPLY:
94 		ct_state |= OVS_CS_F_NEW;
95 		break;
96 	default:
97 		break;
98 	}
99 
100 	return ct_state;
101 }
102 
103 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
104 {
105 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
106 	return ct ? ct->mark : 0;
107 #else
108 	return 0;
109 #endif
110 }
111 
112 static void ovs_ct_get_labels(const struct nf_conn *ct,
113 			      struct ovs_key_ct_labels *labels)
114 {
115 	struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
116 
117 	if (cl) {
118 		size_t len = cl->words * sizeof(long);
119 
120 		if (len > OVS_CT_LABELS_LEN)
121 			len = OVS_CT_LABELS_LEN;
122 		else if (len < OVS_CT_LABELS_LEN)
123 			memset(labels, 0, OVS_CT_LABELS_LEN);
124 		memcpy(labels, cl->bits, len);
125 	} else {
126 		memset(labels, 0, OVS_CT_LABELS_LEN);
127 	}
128 }
129 
130 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
131 				const struct nf_conntrack_zone *zone,
132 				const struct nf_conn *ct)
133 {
134 	key->ct.state = state;
135 	key->ct.zone = zone->id;
136 	key->ct.mark = ovs_ct_get_mark(ct);
137 	ovs_ct_get_labels(ct, &key->ct.labels);
138 }
139 
140 /* Update 'key' based on skb->nfct. If 'post_ct' is true, then OVS has
141  * previously sent the packet to conntrack via the ct action.
142  */
143 static void ovs_ct_update_key(const struct sk_buff *skb,
144 			      struct sw_flow_key *key, bool post_ct)
145 {
146 	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
147 	enum ip_conntrack_info ctinfo;
148 	struct nf_conn *ct;
149 	u8 state = 0;
150 
151 	ct = nf_ct_get(skb, &ctinfo);
152 	if (ct) {
153 		state = ovs_ct_get_state(ctinfo);
154 		if (!nf_ct_is_confirmed(ct))
155 			state |= OVS_CS_F_NEW;
156 		if (ct->master)
157 			state |= OVS_CS_F_RELATED;
158 		zone = nf_ct_zone(ct);
159 	} else if (post_ct) {
160 		state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
161 	}
162 	__ovs_ct_update_key(key, state, zone, ct);
163 }
164 
165 void ovs_ct_fill_key(const struct sk_buff *skb, struct sw_flow_key *key)
166 {
167 	ovs_ct_update_key(skb, key, false);
168 }
169 
170 int ovs_ct_put_key(const struct sw_flow_key *key, struct sk_buff *skb)
171 {
172 	if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, key->ct.state))
173 		return -EMSGSIZE;
174 
175 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
176 	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, key->ct.zone))
177 		return -EMSGSIZE;
178 
179 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
180 	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, key->ct.mark))
181 		return -EMSGSIZE;
182 
183 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
184 	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(key->ct.labels),
185 		    &key->ct.labels))
186 		return -EMSGSIZE;
187 
188 	return 0;
189 }
190 
191 static int ovs_ct_set_mark(struct sk_buff *skb, struct sw_flow_key *key,
192 			   u32 ct_mark, u32 mask)
193 {
194 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
195 	enum ip_conntrack_info ctinfo;
196 	struct nf_conn *ct;
197 	u32 new_mark;
198 
199 
200 	/* The connection could be invalid, in which case set_mark is no-op. */
201 	ct = nf_ct_get(skb, &ctinfo);
202 	if (!ct)
203 		return 0;
204 
205 	new_mark = ct_mark | (ct->mark & ~(mask));
206 	if (ct->mark != new_mark) {
207 		ct->mark = new_mark;
208 		nf_conntrack_event_cache(IPCT_MARK, ct);
209 		key->ct.mark = new_mark;
210 	}
211 
212 	return 0;
213 #else
214 	return -ENOTSUPP;
215 #endif
216 }
217 
218 static int ovs_ct_set_labels(struct sk_buff *skb, struct sw_flow_key *key,
219 			     const struct ovs_key_ct_labels *labels,
220 			     const struct ovs_key_ct_labels *mask)
221 {
222 	enum ip_conntrack_info ctinfo;
223 	struct nf_conn_labels *cl;
224 	struct nf_conn *ct;
225 	int err;
226 
227 	/* The connection could be invalid, in which case set_label is no-op.*/
228 	ct = nf_ct_get(skb, &ctinfo);
229 	if (!ct)
230 		return 0;
231 
232 	cl = nf_ct_labels_find(ct);
233 	if (!cl) {
234 		nf_ct_labels_ext_add(ct);
235 		cl = nf_ct_labels_find(ct);
236 	}
237 	if (!cl || cl->words * sizeof(long) < OVS_CT_LABELS_LEN)
238 		return -ENOSPC;
239 
240 	err = nf_connlabels_replace(ct, (u32 *)labels, (u32 *)mask,
241 				    OVS_CT_LABELS_LEN / sizeof(u32));
242 	if (err)
243 		return err;
244 
245 	ovs_ct_get_labels(ct, &key->ct.labels);
246 	return 0;
247 }
248 
249 /* 'skb' should already be pulled to nh_ofs. */
250 static int ovs_ct_helper(struct sk_buff *skb, u16 proto)
251 {
252 	const struct nf_conntrack_helper *helper;
253 	const struct nf_conn_help *help;
254 	enum ip_conntrack_info ctinfo;
255 	unsigned int protoff;
256 	struct nf_conn *ct;
257 
258 	ct = nf_ct_get(skb, &ctinfo);
259 	if (!ct || ctinfo == IP_CT_RELATED_REPLY)
260 		return NF_ACCEPT;
261 
262 	help = nfct_help(ct);
263 	if (!help)
264 		return NF_ACCEPT;
265 
266 	helper = rcu_dereference(help->helper);
267 	if (!helper)
268 		return NF_ACCEPT;
269 
270 	switch (proto) {
271 	case NFPROTO_IPV4:
272 		protoff = ip_hdrlen(skb);
273 		break;
274 	case NFPROTO_IPV6: {
275 		u8 nexthdr = ipv6_hdr(skb)->nexthdr;
276 		__be16 frag_off;
277 		int ofs;
278 
279 		ofs = ipv6_skip_exthdr(skb, sizeof(struct ipv6hdr), &nexthdr,
280 				       &frag_off);
281 		if (ofs < 0 || (frag_off & htons(~0x7)) != 0) {
282 			pr_debug("proto header not found\n");
283 			return NF_ACCEPT;
284 		}
285 		protoff = ofs;
286 		break;
287 	}
288 	default:
289 		WARN_ONCE(1, "helper invoked on non-IP family!");
290 		return NF_DROP;
291 	}
292 
293 	return helper->help(skb, protoff, ct, ctinfo);
294 }
295 
296 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
297  * value if 'skb' is freed.
298  */
299 static int handle_fragments(struct net *net, struct sw_flow_key *key,
300 			    u16 zone, struct sk_buff *skb)
301 {
302 	struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
303 
304 	if (key->eth.type == htons(ETH_P_IP)) {
305 		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
306 		int err;
307 
308 		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
309 		err = ip_defrag(net, skb, user);
310 		if (err)
311 			return err;
312 
313 		ovs_cb.mru = IPCB(skb)->frag_max_size;
314 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
315 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
316 		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
317 		struct sk_buff *reasm;
318 
319 		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
320 		reasm = nf_ct_frag6_gather(net, skb, user);
321 		if (!reasm)
322 			return -EINPROGRESS;
323 
324 		key->ip.proto = ipv6_hdr(reasm)->nexthdr;
325 		ovs_cb.mru = IP6CB(skb)->frag_max_size;
326 #endif
327 	} else {
328 		kfree_skb(skb);
329 		return -EPFNOSUPPORT;
330 	}
331 
332 	key->ip.frag = OVS_FRAG_TYPE_NONE;
333 	skb_clear_hash(skb);
334 	skb->ignore_df = 1;
335 	*OVS_CB(skb) = ovs_cb;
336 
337 	return 0;
338 }
339 
340 static struct nf_conntrack_expect *
341 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
342 		   u16 proto, const struct sk_buff *skb)
343 {
344 	struct nf_conntrack_tuple tuple;
345 
346 	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
347 		return NULL;
348 	return __nf_ct_expect_find(net, zone, &tuple);
349 }
350 
351 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
352 static bool skb_nfct_cached(const struct net *net, const struct sk_buff *skb,
353 			    const struct ovs_conntrack_info *info)
354 {
355 	enum ip_conntrack_info ctinfo;
356 	struct nf_conn *ct;
357 
358 	ct = nf_ct_get(skb, &ctinfo);
359 	if (!ct)
360 		return false;
361 	if (!net_eq(net, read_pnet(&ct->ct_net)))
362 		return false;
363 	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
364 		return false;
365 	if (info->helper) {
366 		struct nf_conn_help *help;
367 
368 		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
369 		if (help && rcu_access_pointer(help->helper) != info->helper)
370 			return false;
371 	}
372 
373 	return true;
374 }
375 
376 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
377 			   const struct ovs_conntrack_info *info,
378 			   struct sk_buff *skb)
379 {
380 	/* If we are recirculating packets to match on conntrack fields and
381 	 * committing with a separate conntrack action,  then we don't need to
382 	 * actually run the packet through conntrack twice unless it's for a
383 	 * different zone.
384 	 */
385 	if (!skb_nfct_cached(net, skb, info)) {
386 		struct nf_conn *tmpl = info->ct;
387 
388 		/* Associate skb with specified zone. */
389 		if (tmpl) {
390 			if (skb->nfct)
391 				nf_conntrack_put(skb->nfct);
392 			nf_conntrack_get(&tmpl->ct_general);
393 			skb->nfct = &tmpl->ct_general;
394 			skb->nfctinfo = IP_CT_NEW;
395 		}
396 
397 		if (nf_conntrack_in(net, info->family, NF_INET_PRE_ROUTING,
398 				    skb) != NF_ACCEPT)
399 			return -ENOENT;
400 
401 		if (ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
402 			WARN_ONCE(1, "helper rejected packet");
403 			return -EINVAL;
404 		}
405 	}
406 
407 	ovs_ct_update_key(skb, key, true);
408 
409 	return 0;
410 }
411 
412 /* Lookup connection and read fields into key. */
413 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
414 			 const struct ovs_conntrack_info *info,
415 			 struct sk_buff *skb)
416 {
417 	struct nf_conntrack_expect *exp;
418 
419 	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
420 	if (exp) {
421 		u8 state;
422 
423 		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
424 		__ovs_ct_update_key(key, state, &info->zone, exp->master);
425 	} else {
426 		int err;
427 
428 		err = __ovs_ct_lookup(net, key, info, skb);
429 		if (err)
430 			return err;
431 	}
432 
433 	return 0;
434 }
435 
436 /* Lookup connection and confirm if unconfirmed. */
437 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
438 			 const struct ovs_conntrack_info *info,
439 			 struct sk_buff *skb)
440 {
441 	u8 state;
442 	int err;
443 
444 	state = key->ct.state;
445 	if (key->ct.zone == info->zone.id &&
446 	    ((state & OVS_CS_F_TRACKED) && !(state & OVS_CS_F_NEW))) {
447 		/* Previous lookup has shown that this connection is already
448 		 * tracked and committed. Skip committing.
449 		 */
450 		return 0;
451 	}
452 
453 	err = __ovs_ct_lookup(net, key, info, skb);
454 	if (err)
455 		return err;
456 	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
457 		return -EINVAL;
458 
459 	return 0;
460 }
461 
462 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
463 {
464 	size_t i;
465 
466 	for (i = 0; i < sizeof(*labels); i++)
467 		if (labels->ct_labels[i])
468 			return true;
469 
470 	return false;
471 }
472 
473 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
474  * value if 'skb' is freed.
475  */
476 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
477 		   struct sw_flow_key *key,
478 		   const struct ovs_conntrack_info *info)
479 {
480 	int nh_ofs;
481 	int err;
482 
483 	/* The conntrack module expects to be working at L3. */
484 	nh_ofs = skb_network_offset(skb);
485 	skb_pull(skb, nh_ofs);
486 
487 	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
488 		err = handle_fragments(net, key, info->zone.id, skb);
489 		if (err)
490 			return err;
491 	}
492 
493 	if (info->commit)
494 		err = ovs_ct_commit(net, key, info, skb);
495 	else
496 		err = ovs_ct_lookup(net, key, info, skb);
497 	if (err)
498 		goto err;
499 
500 	if (info->mark.mask) {
501 		err = ovs_ct_set_mark(skb, key, info->mark.value,
502 				      info->mark.mask);
503 		if (err)
504 			goto err;
505 	}
506 	if (labels_nonzero(&info->labels.mask))
507 		err = ovs_ct_set_labels(skb, key, &info->labels.value,
508 					&info->labels.mask);
509 err:
510 	skb_push(skb, nh_ofs);
511 	if (err)
512 		kfree_skb(skb);
513 	return err;
514 }
515 
516 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
517 			     const struct sw_flow_key *key, bool log)
518 {
519 	struct nf_conntrack_helper *helper;
520 	struct nf_conn_help *help;
521 
522 	helper = nf_conntrack_helper_try_module_get(name, info->family,
523 						    key->ip.proto);
524 	if (!helper) {
525 		OVS_NLERR(log, "Unknown helper \"%s\"", name);
526 		return -EINVAL;
527 	}
528 
529 	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
530 	if (!help) {
531 		module_put(helper->me);
532 		return -ENOMEM;
533 	}
534 
535 	rcu_assign_pointer(help->helper, helper);
536 	info->helper = helper;
537 	return 0;
538 }
539 
540 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
541 	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
542 	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
543 				    .maxlen = sizeof(u16) },
544 	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
545 				    .maxlen = sizeof(struct md_mark) },
546 	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
547 				    .maxlen = sizeof(struct md_labels) },
548 	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
549 				    .maxlen = NF_CT_HELPER_NAME_LEN }
550 };
551 
552 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
553 		    const char **helper, bool log)
554 {
555 	struct nlattr *a;
556 	int rem;
557 
558 	nla_for_each_nested(a, attr, rem) {
559 		int type = nla_type(a);
560 		int maxlen = ovs_ct_attr_lens[type].maxlen;
561 		int minlen = ovs_ct_attr_lens[type].minlen;
562 
563 		if (type > OVS_CT_ATTR_MAX) {
564 			OVS_NLERR(log,
565 				  "Unknown conntrack attr (type=%d, max=%d)",
566 				  type, OVS_CT_ATTR_MAX);
567 			return -EINVAL;
568 		}
569 		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
570 			OVS_NLERR(log,
571 				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
572 				  type, nla_len(a), maxlen);
573 			return -EINVAL;
574 		}
575 
576 		switch (type) {
577 		case OVS_CT_ATTR_COMMIT:
578 			info->commit = true;
579 			break;
580 #ifdef CONFIG_NF_CONNTRACK_ZONES
581 		case OVS_CT_ATTR_ZONE:
582 			info->zone.id = nla_get_u16(a);
583 			break;
584 #endif
585 #ifdef CONFIG_NF_CONNTRACK_MARK
586 		case OVS_CT_ATTR_MARK: {
587 			struct md_mark *mark = nla_data(a);
588 
589 			if (!mark->mask) {
590 				OVS_NLERR(log, "ct_mark mask cannot be 0");
591 				return -EINVAL;
592 			}
593 			info->mark = *mark;
594 			break;
595 		}
596 #endif
597 #ifdef CONFIG_NF_CONNTRACK_LABELS
598 		case OVS_CT_ATTR_LABELS: {
599 			struct md_labels *labels = nla_data(a);
600 
601 			if (!labels_nonzero(&labels->mask)) {
602 				OVS_NLERR(log, "ct_labels mask cannot be 0");
603 				return -EINVAL;
604 			}
605 			info->labels = *labels;
606 			break;
607 		}
608 #endif
609 		case OVS_CT_ATTR_HELPER:
610 			*helper = nla_data(a);
611 			if (!memchr(*helper, '\0', nla_len(a))) {
612 				OVS_NLERR(log, "Invalid conntrack helper");
613 				return -EINVAL;
614 			}
615 			break;
616 		default:
617 			OVS_NLERR(log, "Unknown conntrack attr (%d)",
618 				  type);
619 			return -EINVAL;
620 		}
621 	}
622 
623 	if (rem > 0) {
624 		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
625 		return -EINVAL;
626 	}
627 
628 	return 0;
629 }
630 
631 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
632 {
633 	if (attr == OVS_KEY_ATTR_CT_STATE)
634 		return true;
635 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
636 	    attr == OVS_KEY_ATTR_CT_ZONE)
637 		return true;
638 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
639 	    attr == OVS_KEY_ATTR_CT_MARK)
640 		return true;
641 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
642 	    attr == OVS_KEY_ATTR_CT_LABELS) {
643 		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
644 
645 		return ovs_net->xt_label;
646 	}
647 
648 	return false;
649 }
650 
651 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
652 		       const struct sw_flow_key *key,
653 		       struct sw_flow_actions **sfa,  bool log)
654 {
655 	struct ovs_conntrack_info ct_info;
656 	const char *helper = NULL;
657 	u16 family;
658 	int err;
659 
660 	family = key_to_nfproto(key);
661 	if (family == NFPROTO_UNSPEC) {
662 		OVS_NLERR(log, "ct family unspecified");
663 		return -EINVAL;
664 	}
665 
666 	memset(&ct_info, 0, sizeof(ct_info));
667 	ct_info.family = family;
668 
669 	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
670 			NF_CT_DEFAULT_ZONE_DIR, 0);
671 
672 	err = parse_ct(attr, &ct_info, &helper, log);
673 	if (err)
674 		return err;
675 
676 	/* Set up template for tracking connections in specific zones. */
677 	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
678 	if (!ct_info.ct) {
679 		OVS_NLERR(log, "Failed to allocate conntrack template");
680 		return -ENOMEM;
681 	}
682 	if (helper) {
683 		err = ovs_ct_add_helper(&ct_info, helper, key, log);
684 		if (err)
685 			goto err_free_ct;
686 	}
687 
688 	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
689 				 sizeof(ct_info), log);
690 	if (err)
691 		goto err_free_ct;
692 
693 	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
694 	nf_conntrack_get(&ct_info.ct->ct_general);
695 	return 0;
696 err_free_ct:
697 	nf_conntrack_free(ct_info.ct);
698 	return err;
699 }
700 
701 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
702 			  struct sk_buff *skb)
703 {
704 	struct nlattr *start;
705 
706 	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
707 	if (!start)
708 		return -EMSGSIZE;
709 
710 	if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
711 		return -EMSGSIZE;
712 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
713 	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
714 		return -EMSGSIZE;
715 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
716 	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
717 		    &ct_info->mark))
718 		return -EMSGSIZE;
719 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
720 	    labels_nonzero(&ct_info->labels.mask) &&
721 	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
722 		    &ct_info->labels))
723 		return -EMSGSIZE;
724 	if (ct_info->helper) {
725 		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
726 				   ct_info->helper->name))
727 			return -EMSGSIZE;
728 	}
729 
730 	nla_nest_end(skb, start);
731 
732 	return 0;
733 }
734 
735 void ovs_ct_free_action(const struct nlattr *a)
736 {
737 	struct ovs_conntrack_info *ct_info = nla_data(a);
738 
739 	if (ct_info->helper)
740 		module_put(ct_info->helper->me);
741 	if (ct_info->ct)
742 		nf_ct_put(ct_info->ct);
743 }
744 
745 void ovs_ct_init(struct net *net)
746 {
747 	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
748 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
749 
750 	if (nf_connlabels_get(net, n_bits)) {
751 		ovs_net->xt_label = false;
752 		OVS_NLERR(true, "Failed to set connlabel length");
753 	} else {
754 		ovs_net->xt_label = true;
755 	}
756 }
757 
758 void ovs_ct_exit(struct net *net)
759 {
760 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
761 
762 	if (ovs_net->xt_label)
763 		nf_connlabels_put(net);
764 }
765