xref: /linux/net/openvswitch/conntrack.c (revision 9125f19bbb97e7444b5ea01f8262fa09679e1376)
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 		skb_orphan(skb);
371 		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
372 		err = nf_ct_frag6_gather(net, skb, user);
373 		if (err)
374 			return err;
375 
376 		key->ip.proto = ipv6_hdr(skb)->nexthdr;
377 		ovs_cb.mru = IP6CB(skb)->frag_max_size;
378 #endif
379 	} else {
380 		kfree_skb(skb);
381 		return -EPFNOSUPPORT;
382 	}
383 
384 	key->ip.frag = OVS_FRAG_TYPE_NONE;
385 	skb_clear_hash(skb);
386 	skb->ignore_df = 1;
387 	*OVS_CB(skb) = ovs_cb;
388 
389 	return 0;
390 }
391 
392 static struct nf_conntrack_expect *
393 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
394 		   u16 proto, const struct sk_buff *skb)
395 {
396 	struct nf_conntrack_tuple tuple;
397 
398 	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
399 		return NULL;
400 	return __nf_ct_expect_find(net, zone, &tuple);
401 }
402 
403 /* This replicates logic from nf_conntrack_core.c that is not exported. */
404 static enum ip_conntrack_info
405 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
406 {
407 	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
408 
409 	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
410 		return IP_CT_ESTABLISHED_REPLY;
411 	/* Once we've had two way comms, always ESTABLISHED. */
412 	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
413 		return IP_CT_ESTABLISHED;
414 	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
415 		return IP_CT_RELATED;
416 	return IP_CT_NEW;
417 }
418 
419 /* Find an existing connection which this packet belongs to without
420  * re-attributing statistics or modifying the connection state.  This allows an
421  * skb->nfct lost due to an upcall to be recovered during actions execution.
422  *
423  * Must be called with rcu_read_lock.
424  *
425  * On success, populates skb->nfct and skb->nfctinfo, and returns the
426  * connection.  Returns NULL if there is no existing entry.
427  */
428 static struct nf_conn *
429 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
430 		     u8 l3num, struct sk_buff *skb)
431 {
432 	struct nf_conntrack_l3proto *l3proto;
433 	struct nf_conntrack_l4proto *l4proto;
434 	struct nf_conntrack_tuple tuple;
435 	struct nf_conntrack_tuple_hash *h;
436 	enum ip_conntrack_info ctinfo;
437 	struct nf_conn *ct;
438 	unsigned int dataoff;
439 	u8 protonum;
440 
441 	l3proto = __nf_ct_l3proto_find(l3num);
442 	if (!l3proto) {
443 		pr_debug("ovs_ct_find_existing: Can't get l3proto\n");
444 		return NULL;
445 	}
446 	if (l3proto->get_l4proto(skb, skb_network_offset(skb), &dataoff,
447 				 &protonum) <= 0) {
448 		pr_debug("ovs_ct_find_existing: Can't get protonum\n");
449 		return NULL;
450 	}
451 	l4proto = __nf_ct_l4proto_find(l3num, protonum);
452 	if (!l4proto) {
453 		pr_debug("ovs_ct_find_existing: Can't get l4proto\n");
454 		return NULL;
455 	}
456 	if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
457 			     protonum, net, &tuple, l3proto, l4proto)) {
458 		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
459 		return NULL;
460 	}
461 
462 	/* look for tuple match */
463 	h = nf_conntrack_find_get(net, zone, &tuple);
464 	if (!h)
465 		return NULL;   /* Not found. */
466 
467 	ct = nf_ct_tuplehash_to_ctrack(h);
468 
469 	ctinfo = ovs_ct_get_info(h);
470 	if (ctinfo == IP_CT_NEW) {
471 		/* This should not happen. */
472 		WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
473 	}
474 	skb->nfct = &ct->ct_general;
475 	skb->nfctinfo = ctinfo;
476 	return ct;
477 }
478 
479 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
480 static bool skb_nfct_cached(struct net *net,
481 			    const struct sw_flow_key *key,
482 			    const struct ovs_conntrack_info *info,
483 			    struct sk_buff *skb)
484 {
485 	enum ip_conntrack_info ctinfo;
486 	struct nf_conn *ct;
487 
488 	ct = nf_ct_get(skb, &ctinfo);
489 	/* If no ct, check if we have evidence that an existing conntrack entry
490 	 * might be found for this skb.  This happens when we lose a skb->nfct
491 	 * due to an upcall.  If the connection was not confirmed, it is not
492 	 * cached and needs to be run through conntrack again.
493 	 */
494 	if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
495 	    !(key->ct.state & OVS_CS_F_INVALID) &&
496 	    key->ct.zone == info->zone.id)
497 		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
498 	if (!ct)
499 		return false;
500 	if (!net_eq(net, read_pnet(&ct->ct_net)))
501 		return false;
502 	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
503 		return false;
504 	if (info->helper) {
505 		struct nf_conn_help *help;
506 
507 		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
508 		if (help && rcu_access_pointer(help->helper) != info->helper)
509 			return false;
510 	}
511 
512 	return true;
513 }
514 
515 #ifdef CONFIG_NF_NAT_NEEDED
516 /* Modelled after nf_nat_ipv[46]_fn().
517  * range is only used for new, uninitialized NAT state.
518  * Returns either NF_ACCEPT or NF_DROP.
519  */
520 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
521 			      enum ip_conntrack_info ctinfo,
522 			      const struct nf_nat_range *range,
523 			      enum nf_nat_manip_type maniptype)
524 {
525 	int hooknum, nh_off, err = NF_ACCEPT;
526 
527 	nh_off = skb_network_offset(skb);
528 	skb_pull(skb, nh_off);
529 
530 	/* See HOOK2MANIP(). */
531 	if (maniptype == NF_NAT_MANIP_SRC)
532 		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
533 	else
534 		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
535 
536 	switch (ctinfo) {
537 	case IP_CT_RELATED:
538 	case IP_CT_RELATED_REPLY:
539 		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
540 		    skb->protocol == htons(ETH_P_IP) &&
541 		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
542 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
543 							   hooknum))
544 				err = NF_DROP;
545 			goto push;
546 		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
547 			   skb->protocol == htons(ETH_P_IPV6)) {
548 			__be16 frag_off;
549 			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
550 			int hdrlen = ipv6_skip_exthdr(skb,
551 						      sizeof(struct ipv6hdr),
552 						      &nexthdr, &frag_off);
553 
554 			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
555 				if (!nf_nat_icmpv6_reply_translation(skb, ct,
556 								     ctinfo,
557 								     hooknum,
558 								     hdrlen))
559 					err = NF_DROP;
560 				goto push;
561 			}
562 		}
563 		/* Non-ICMP, fall thru to initialize if needed. */
564 	case IP_CT_NEW:
565 		/* Seen it before?  This can happen for loopback, retrans,
566 		 * or local packets.
567 		 */
568 		if (!nf_nat_initialized(ct, maniptype)) {
569 			/* Initialize according to the NAT action. */
570 			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
571 				/* Action is set up to establish a new
572 				 * mapping.
573 				 */
574 				? nf_nat_setup_info(ct, range, maniptype)
575 				: nf_nat_alloc_null_binding(ct, hooknum);
576 			if (err != NF_ACCEPT)
577 				goto push;
578 		}
579 		break;
580 
581 	case IP_CT_ESTABLISHED:
582 	case IP_CT_ESTABLISHED_REPLY:
583 		break;
584 
585 	default:
586 		err = NF_DROP;
587 		goto push;
588 	}
589 
590 	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
591 push:
592 	skb_push(skb, nh_off);
593 
594 	return err;
595 }
596 
597 static void ovs_nat_update_key(struct sw_flow_key *key,
598 			       const struct sk_buff *skb,
599 			       enum nf_nat_manip_type maniptype)
600 {
601 	if (maniptype == NF_NAT_MANIP_SRC) {
602 		__be16 src;
603 
604 		key->ct.state |= OVS_CS_F_SRC_NAT;
605 		if (key->eth.type == htons(ETH_P_IP))
606 			key->ipv4.addr.src = ip_hdr(skb)->saddr;
607 		else if (key->eth.type == htons(ETH_P_IPV6))
608 			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
609 			       sizeof(key->ipv6.addr.src));
610 		else
611 			return;
612 
613 		if (key->ip.proto == IPPROTO_UDP)
614 			src = udp_hdr(skb)->source;
615 		else if (key->ip.proto == IPPROTO_TCP)
616 			src = tcp_hdr(skb)->source;
617 		else if (key->ip.proto == IPPROTO_SCTP)
618 			src = sctp_hdr(skb)->source;
619 		else
620 			return;
621 
622 		key->tp.src = src;
623 	} else {
624 		__be16 dst;
625 
626 		key->ct.state |= OVS_CS_F_DST_NAT;
627 		if (key->eth.type == htons(ETH_P_IP))
628 			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
629 		else if (key->eth.type == htons(ETH_P_IPV6))
630 			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
631 			       sizeof(key->ipv6.addr.dst));
632 		else
633 			return;
634 
635 		if (key->ip.proto == IPPROTO_UDP)
636 			dst = udp_hdr(skb)->dest;
637 		else if (key->ip.proto == IPPROTO_TCP)
638 			dst = tcp_hdr(skb)->dest;
639 		else if (key->ip.proto == IPPROTO_SCTP)
640 			dst = sctp_hdr(skb)->dest;
641 		else
642 			return;
643 
644 		key->tp.dst = dst;
645 	}
646 }
647 
648 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
649 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
650 		      const struct ovs_conntrack_info *info,
651 		      struct sk_buff *skb, struct nf_conn *ct,
652 		      enum ip_conntrack_info ctinfo)
653 {
654 	enum nf_nat_manip_type maniptype;
655 	int err;
656 
657 	if (nf_ct_is_untracked(ct)) {
658 		/* A NAT action may only be performed on tracked packets. */
659 		return NF_ACCEPT;
660 	}
661 
662 	/* Add NAT extension if not confirmed yet. */
663 	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
664 		return NF_ACCEPT;   /* Can't NAT. */
665 
666 	/* Determine NAT type.
667 	 * Check if the NAT type can be deduced from the tracked connection.
668 	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
669 	 * when committing.
670 	 */
671 	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
672 	    ct->status & IPS_NAT_MASK &&
673 	    (ctinfo != IP_CT_RELATED || info->commit)) {
674 		/* NAT an established or related connection like before. */
675 		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
676 			/* This is the REPLY direction for a connection
677 			 * for which NAT was applied in the forward
678 			 * direction.  Do the reverse NAT.
679 			 */
680 			maniptype = ct->status & IPS_SRC_NAT
681 				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
682 		else
683 			maniptype = ct->status & IPS_SRC_NAT
684 				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
685 	} else if (info->nat & OVS_CT_SRC_NAT) {
686 		maniptype = NF_NAT_MANIP_SRC;
687 	} else if (info->nat & OVS_CT_DST_NAT) {
688 		maniptype = NF_NAT_MANIP_DST;
689 	} else {
690 		return NF_ACCEPT; /* Connection is not NATed. */
691 	}
692 	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
693 
694 	/* Mark NAT done if successful and update the flow key. */
695 	if (err == NF_ACCEPT)
696 		ovs_nat_update_key(key, skb, maniptype);
697 
698 	return err;
699 }
700 #else /* !CONFIG_NF_NAT_NEEDED */
701 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
702 		      const struct ovs_conntrack_info *info,
703 		      struct sk_buff *skb, struct nf_conn *ct,
704 		      enum ip_conntrack_info ctinfo)
705 {
706 	return NF_ACCEPT;
707 }
708 #endif
709 
710 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
711  * not done already.  Update key with new CT state after passing the packet
712  * through conntrack.
713  * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
714  * set to NULL and 0 will be returned.
715  */
716 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
717 			   const struct ovs_conntrack_info *info,
718 			   struct sk_buff *skb)
719 {
720 	/* If we are recirculating packets to match on conntrack fields and
721 	 * committing with a separate conntrack action,  then we don't need to
722 	 * actually run the packet through conntrack twice unless it's for a
723 	 * different zone.
724 	 */
725 	bool cached = skb_nfct_cached(net, key, info, skb);
726 	enum ip_conntrack_info ctinfo;
727 	struct nf_conn *ct;
728 
729 	if (!cached) {
730 		struct nf_conn *tmpl = info->ct;
731 		int err;
732 
733 		/* Associate skb with specified zone. */
734 		if (tmpl) {
735 			if (skb->nfct)
736 				nf_conntrack_put(skb->nfct);
737 			nf_conntrack_get(&tmpl->ct_general);
738 			skb->nfct = &tmpl->ct_general;
739 			skb->nfctinfo = IP_CT_NEW;
740 		}
741 
742 		/* Repeat if requested, see nf_iterate(). */
743 		do {
744 			err = nf_conntrack_in(net, info->family,
745 					      NF_INET_PRE_ROUTING, skb);
746 		} while (err == NF_REPEAT);
747 
748 		if (err != NF_ACCEPT)
749 			return -ENOENT;
750 
751 		/* Clear CT state NAT flags to mark that we have not yet done
752 		 * NAT after the nf_conntrack_in() call.  We can actually clear
753 		 * the whole state, as it will be re-initialized below.
754 		 */
755 		key->ct.state = 0;
756 
757 		/* Update the key, but keep the NAT flags. */
758 		ovs_ct_update_key(skb, info, key, true, true);
759 	}
760 
761 	ct = nf_ct_get(skb, &ctinfo);
762 	if (ct) {
763 		/* Packets starting a new connection must be NATted before the
764 		 * helper, so that the helper knows about the NAT.  We enforce
765 		 * this by delaying both NAT and helper calls for unconfirmed
766 		 * connections until the committing CT action.  For later
767 		 * packets NAT and Helper may be called in either order.
768 		 *
769 		 * NAT will be done only if the CT action has NAT, and only
770 		 * once per packet (per zone), as guarded by the NAT bits in
771 		 * the key->ct.state.
772 		 */
773 		if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
774 		    (nf_ct_is_confirmed(ct) || info->commit) &&
775 		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
776 			return -EINVAL;
777 		}
778 
779 		/* Call the helper only if:
780 		 * - nf_conntrack_in() was executed above ("!cached") for a
781 		 *   confirmed connection, or
782 		 * - When committing an unconfirmed connection.
783 		 */
784 		if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
785 		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
786 			return -EINVAL;
787 		}
788 	}
789 
790 	return 0;
791 }
792 
793 /* Lookup connection and read fields into key. */
794 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
795 			 const struct ovs_conntrack_info *info,
796 			 struct sk_buff *skb)
797 {
798 	struct nf_conntrack_expect *exp;
799 
800 	/* If we pass an expected packet through nf_conntrack_in() the
801 	 * expectation is typically removed, but the packet could still be
802 	 * lost in upcall processing.  To prevent this from happening we
803 	 * perform an explicit expectation lookup.  Expected connections are
804 	 * always new, and will be passed through conntrack only when they are
805 	 * committed, as it is OK to remove the expectation at that time.
806 	 */
807 	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
808 	if (exp) {
809 		u8 state;
810 
811 		/* NOTE: New connections are NATted and Helped only when
812 		 * committed, so we are not calling into NAT here.
813 		 */
814 		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
815 		__ovs_ct_update_key(key, state, &info->zone, exp->master);
816 	} else
817 		return __ovs_ct_lookup(net, key, info, skb);
818 
819 	return 0;
820 }
821 
822 /* Lookup connection and confirm if unconfirmed. */
823 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
824 			 const struct ovs_conntrack_info *info,
825 			 struct sk_buff *skb)
826 {
827 	int err;
828 
829 	err = __ovs_ct_lookup(net, key, info, skb);
830 	if (err)
831 		return err;
832 	/* This is a no-op if the connection has already been confirmed. */
833 	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
834 		return -EINVAL;
835 
836 	return 0;
837 }
838 
839 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
840 {
841 	size_t i;
842 
843 	for (i = 0; i < sizeof(*labels); i++)
844 		if (labels->ct_labels[i])
845 			return true;
846 
847 	return false;
848 }
849 
850 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
851  * value if 'skb' is freed.
852  */
853 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
854 		   struct sw_flow_key *key,
855 		   const struct ovs_conntrack_info *info)
856 {
857 	int nh_ofs;
858 	int err;
859 
860 	/* The conntrack module expects to be working at L3. */
861 	nh_ofs = skb_network_offset(skb);
862 	skb_pull(skb, nh_ofs);
863 
864 	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
865 		err = handle_fragments(net, key, info->zone.id, skb);
866 		if (err)
867 			return err;
868 	}
869 
870 	if (info->commit)
871 		err = ovs_ct_commit(net, key, info, skb);
872 	else
873 		err = ovs_ct_lookup(net, key, info, skb);
874 	if (err)
875 		goto err;
876 
877 	if (info->mark.mask) {
878 		err = ovs_ct_set_mark(skb, key, info->mark.value,
879 				      info->mark.mask);
880 		if (err)
881 			goto err;
882 	}
883 	if (labels_nonzero(&info->labels.mask))
884 		err = ovs_ct_set_labels(skb, key, &info->labels.value,
885 					&info->labels.mask);
886 err:
887 	skb_push(skb, nh_ofs);
888 	if (err)
889 		kfree_skb(skb);
890 	return err;
891 }
892 
893 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
894 			     const struct sw_flow_key *key, bool log)
895 {
896 	struct nf_conntrack_helper *helper;
897 	struct nf_conn_help *help;
898 
899 	helper = nf_conntrack_helper_try_module_get(name, info->family,
900 						    key->ip.proto);
901 	if (!helper) {
902 		OVS_NLERR(log, "Unknown helper \"%s\"", name);
903 		return -EINVAL;
904 	}
905 
906 	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
907 	if (!help) {
908 		module_put(helper->me);
909 		return -ENOMEM;
910 	}
911 
912 	rcu_assign_pointer(help->helper, helper);
913 	info->helper = helper;
914 	return 0;
915 }
916 
917 #ifdef CONFIG_NF_NAT_NEEDED
918 static int parse_nat(const struct nlattr *attr,
919 		     struct ovs_conntrack_info *info, bool log)
920 {
921 	struct nlattr *a;
922 	int rem;
923 	bool have_ip_max = false;
924 	bool have_proto_max = false;
925 	bool ip_vers = (info->family == NFPROTO_IPV6);
926 
927 	nla_for_each_nested(a, attr, rem) {
928 		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
929 			[OVS_NAT_ATTR_SRC] = {0, 0},
930 			[OVS_NAT_ATTR_DST] = {0, 0},
931 			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
932 						 sizeof(struct in6_addr)},
933 			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
934 						 sizeof(struct in6_addr)},
935 			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
936 			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
937 			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
938 			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
939 			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
940 		};
941 		int type = nla_type(a);
942 
943 		if (type > OVS_NAT_ATTR_MAX) {
944 			OVS_NLERR(log,
945 				  "Unknown NAT attribute (type=%d, max=%d).\n",
946 				  type, OVS_NAT_ATTR_MAX);
947 			return -EINVAL;
948 		}
949 
950 		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
951 			OVS_NLERR(log,
952 				  "NAT attribute type %d has unexpected length (%d != %d).\n",
953 				  type, nla_len(a),
954 				  ovs_nat_attr_lens[type][ip_vers]);
955 			return -EINVAL;
956 		}
957 
958 		switch (type) {
959 		case OVS_NAT_ATTR_SRC:
960 		case OVS_NAT_ATTR_DST:
961 			if (info->nat) {
962 				OVS_NLERR(log,
963 					  "Only one type of NAT may be specified.\n"
964 					  );
965 				return -ERANGE;
966 			}
967 			info->nat |= OVS_CT_NAT;
968 			info->nat |= ((type == OVS_NAT_ATTR_SRC)
969 					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
970 			break;
971 
972 		case OVS_NAT_ATTR_IP_MIN:
973 			nla_memcpy(&info->range.min_addr, a,
974 				   sizeof(info->range.min_addr));
975 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
976 			break;
977 
978 		case OVS_NAT_ATTR_IP_MAX:
979 			have_ip_max = true;
980 			nla_memcpy(&info->range.max_addr, a,
981 				   sizeof(info->range.max_addr));
982 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
983 			break;
984 
985 		case OVS_NAT_ATTR_PROTO_MIN:
986 			info->range.min_proto.all = htons(nla_get_u16(a));
987 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
988 			break;
989 
990 		case OVS_NAT_ATTR_PROTO_MAX:
991 			have_proto_max = true;
992 			info->range.max_proto.all = htons(nla_get_u16(a));
993 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
994 			break;
995 
996 		case OVS_NAT_ATTR_PERSISTENT:
997 			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
998 			break;
999 
1000 		case OVS_NAT_ATTR_PROTO_HASH:
1001 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1002 			break;
1003 
1004 		case OVS_NAT_ATTR_PROTO_RANDOM:
1005 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1006 			break;
1007 
1008 		default:
1009 			OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
1010 			return -EINVAL;
1011 		}
1012 	}
1013 
1014 	if (rem > 0) {
1015 		OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
1016 		return -EINVAL;
1017 	}
1018 	if (!info->nat) {
1019 		/* Do not allow flags if no type is given. */
1020 		if (info->range.flags) {
1021 			OVS_NLERR(log,
1022 				  "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
1023 				  );
1024 			return -EINVAL;
1025 		}
1026 		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1027 	} else if (!info->commit) {
1028 		OVS_NLERR(log,
1029 			  "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
1030 			  );
1031 		return -EINVAL;
1032 	}
1033 	/* Allow missing IP_MAX. */
1034 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1035 		memcpy(&info->range.max_addr, &info->range.min_addr,
1036 		       sizeof(info->range.max_addr));
1037 	}
1038 	/* Allow missing PROTO_MAX. */
1039 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1040 	    !have_proto_max) {
1041 		info->range.max_proto.all = info->range.min_proto.all;
1042 	}
1043 	return 0;
1044 }
1045 #endif
1046 
1047 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1048 	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1049 	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
1050 				    .maxlen = sizeof(u16) },
1051 	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
1052 				    .maxlen = sizeof(struct md_mark) },
1053 	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
1054 				    .maxlen = sizeof(struct md_labels) },
1055 	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
1056 				    .maxlen = NF_CT_HELPER_NAME_LEN },
1057 #ifdef CONFIG_NF_NAT_NEEDED
1058 	/* NAT length is checked when parsing the nested attributes. */
1059 	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
1060 #endif
1061 };
1062 
1063 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1064 		    const char **helper, bool log)
1065 {
1066 	struct nlattr *a;
1067 	int rem;
1068 
1069 	nla_for_each_nested(a, attr, rem) {
1070 		int type = nla_type(a);
1071 		int maxlen = ovs_ct_attr_lens[type].maxlen;
1072 		int minlen = ovs_ct_attr_lens[type].minlen;
1073 
1074 		if (type > OVS_CT_ATTR_MAX) {
1075 			OVS_NLERR(log,
1076 				  "Unknown conntrack attr (type=%d, max=%d)",
1077 				  type, OVS_CT_ATTR_MAX);
1078 			return -EINVAL;
1079 		}
1080 		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1081 			OVS_NLERR(log,
1082 				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1083 				  type, nla_len(a), maxlen);
1084 			return -EINVAL;
1085 		}
1086 
1087 		switch (type) {
1088 		case OVS_CT_ATTR_COMMIT:
1089 			info->commit = true;
1090 			break;
1091 #ifdef CONFIG_NF_CONNTRACK_ZONES
1092 		case OVS_CT_ATTR_ZONE:
1093 			info->zone.id = nla_get_u16(a);
1094 			break;
1095 #endif
1096 #ifdef CONFIG_NF_CONNTRACK_MARK
1097 		case OVS_CT_ATTR_MARK: {
1098 			struct md_mark *mark = nla_data(a);
1099 
1100 			if (!mark->mask) {
1101 				OVS_NLERR(log, "ct_mark mask cannot be 0");
1102 				return -EINVAL;
1103 			}
1104 			info->mark = *mark;
1105 			break;
1106 		}
1107 #endif
1108 #ifdef CONFIG_NF_CONNTRACK_LABELS
1109 		case OVS_CT_ATTR_LABELS: {
1110 			struct md_labels *labels = nla_data(a);
1111 
1112 			if (!labels_nonzero(&labels->mask)) {
1113 				OVS_NLERR(log, "ct_labels mask cannot be 0");
1114 				return -EINVAL;
1115 			}
1116 			info->labels = *labels;
1117 			break;
1118 		}
1119 #endif
1120 		case OVS_CT_ATTR_HELPER:
1121 			*helper = nla_data(a);
1122 			if (!memchr(*helper, '\0', nla_len(a))) {
1123 				OVS_NLERR(log, "Invalid conntrack helper");
1124 				return -EINVAL;
1125 			}
1126 			break;
1127 #ifdef CONFIG_NF_NAT_NEEDED
1128 		case OVS_CT_ATTR_NAT: {
1129 			int err = parse_nat(a, info, log);
1130 
1131 			if (err)
1132 				return err;
1133 			break;
1134 		}
1135 #endif
1136 		default:
1137 			OVS_NLERR(log, "Unknown conntrack attr (%d)",
1138 				  type);
1139 			return -EINVAL;
1140 		}
1141 	}
1142 
1143 	if (rem > 0) {
1144 		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1145 		return -EINVAL;
1146 	}
1147 
1148 	return 0;
1149 }
1150 
1151 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1152 {
1153 	if (attr == OVS_KEY_ATTR_CT_STATE)
1154 		return true;
1155 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1156 	    attr == OVS_KEY_ATTR_CT_ZONE)
1157 		return true;
1158 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1159 	    attr == OVS_KEY_ATTR_CT_MARK)
1160 		return true;
1161 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1162 	    attr == OVS_KEY_ATTR_CT_LABELS) {
1163 		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1164 
1165 		return ovs_net->xt_label;
1166 	}
1167 
1168 	return false;
1169 }
1170 
1171 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1172 		       const struct sw_flow_key *key,
1173 		       struct sw_flow_actions **sfa,  bool log)
1174 {
1175 	struct ovs_conntrack_info ct_info;
1176 	const char *helper = NULL;
1177 	u16 family;
1178 	int err;
1179 
1180 	family = key_to_nfproto(key);
1181 	if (family == NFPROTO_UNSPEC) {
1182 		OVS_NLERR(log, "ct family unspecified");
1183 		return -EINVAL;
1184 	}
1185 
1186 	memset(&ct_info, 0, sizeof(ct_info));
1187 	ct_info.family = family;
1188 
1189 	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1190 			NF_CT_DEFAULT_ZONE_DIR, 0);
1191 
1192 	err = parse_ct(attr, &ct_info, &helper, log);
1193 	if (err)
1194 		return err;
1195 
1196 	/* Set up template for tracking connections in specific zones. */
1197 	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1198 	if (!ct_info.ct) {
1199 		OVS_NLERR(log, "Failed to allocate conntrack template");
1200 		return -ENOMEM;
1201 	}
1202 
1203 	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1204 	nf_conntrack_get(&ct_info.ct->ct_general);
1205 
1206 	if (helper) {
1207 		err = ovs_ct_add_helper(&ct_info, helper, key, log);
1208 		if (err)
1209 			goto err_free_ct;
1210 	}
1211 
1212 	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1213 				 sizeof(ct_info), log);
1214 	if (err)
1215 		goto err_free_ct;
1216 
1217 	return 0;
1218 err_free_ct:
1219 	__ovs_ct_free_action(&ct_info);
1220 	return err;
1221 }
1222 
1223 #ifdef CONFIG_NF_NAT_NEEDED
1224 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1225 			       struct sk_buff *skb)
1226 {
1227 	struct nlattr *start;
1228 
1229 	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1230 	if (!start)
1231 		return false;
1232 
1233 	if (info->nat & OVS_CT_SRC_NAT) {
1234 		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1235 			return false;
1236 	} else if (info->nat & OVS_CT_DST_NAT) {
1237 		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1238 			return false;
1239 	} else {
1240 		goto out;
1241 	}
1242 
1243 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1244 		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1245 		    info->family == NFPROTO_IPV4) {
1246 			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1247 					    info->range.min_addr.ip) ||
1248 			    (info->range.max_addr.ip
1249 			     != info->range.min_addr.ip &&
1250 			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1251 					      info->range.max_addr.ip))))
1252 				return false;
1253 		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1254 			   info->family == NFPROTO_IPV6) {
1255 			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1256 					     &info->range.min_addr.in6) ||
1257 			    (memcmp(&info->range.max_addr.in6,
1258 				    &info->range.min_addr.in6,
1259 				    sizeof(info->range.max_addr.in6)) &&
1260 			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1261 					       &info->range.max_addr.in6))))
1262 				return false;
1263 		} else {
1264 			return false;
1265 		}
1266 	}
1267 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1268 	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1269 			 ntohs(info->range.min_proto.all)) ||
1270 	     (info->range.max_proto.all != info->range.min_proto.all &&
1271 	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1272 			  ntohs(info->range.max_proto.all)))))
1273 		return false;
1274 
1275 	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1276 	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1277 		return false;
1278 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1279 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1280 		return false;
1281 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1282 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1283 		return false;
1284 out:
1285 	nla_nest_end(skb, start);
1286 
1287 	return true;
1288 }
1289 #endif
1290 
1291 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1292 			  struct sk_buff *skb)
1293 {
1294 	struct nlattr *start;
1295 
1296 	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1297 	if (!start)
1298 		return -EMSGSIZE;
1299 
1300 	if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
1301 		return -EMSGSIZE;
1302 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1303 	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1304 		return -EMSGSIZE;
1305 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1306 	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1307 		    &ct_info->mark))
1308 		return -EMSGSIZE;
1309 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1310 	    labels_nonzero(&ct_info->labels.mask) &&
1311 	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1312 		    &ct_info->labels))
1313 		return -EMSGSIZE;
1314 	if (ct_info->helper) {
1315 		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1316 				   ct_info->helper->name))
1317 			return -EMSGSIZE;
1318 	}
1319 #ifdef CONFIG_NF_NAT_NEEDED
1320 	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1321 		return -EMSGSIZE;
1322 #endif
1323 	nla_nest_end(skb, start);
1324 
1325 	return 0;
1326 }
1327 
1328 void ovs_ct_free_action(const struct nlattr *a)
1329 {
1330 	struct ovs_conntrack_info *ct_info = nla_data(a);
1331 
1332 	__ovs_ct_free_action(ct_info);
1333 }
1334 
1335 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1336 {
1337 	if (ct_info->helper)
1338 		module_put(ct_info->helper->me);
1339 	if (ct_info->ct)
1340 		nf_ct_put(ct_info->ct);
1341 }
1342 
1343 void ovs_ct_init(struct net *net)
1344 {
1345 	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1346 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1347 
1348 	if (nf_connlabels_get(net, n_bits)) {
1349 		ovs_net->xt_label = false;
1350 		OVS_NLERR(true, "Failed to set connlabel length");
1351 	} else {
1352 		ovs_net->xt_label = true;
1353 	}
1354 }
1355 
1356 void ovs_ct_exit(struct net *net)
1357 {
1358 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1359 
1360 	if (ovs_net->xt_label)
1361 		nf_connlabels_put(net);
1362 }
1363