xref: /linux/net/openvswitch/conntrack.c (revision 2bc46b3ad3c15165f91459b07ff8682478683194)
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->get_l4proto(skb, skb_network_offset(skb), &dataoff,
443 				 &protonum) <= 0) {
444 		pr_debug("ovs_ct_find_existing: Can't get protonum\n");
445 		return NULL;
446 	}
447 	l4proto = __nf_ct_l4proto_find(l3num, protonum);
448 	if (!nf_ct_get_tuple(skb, skb_network_offset(skb), dataoff, l3num,
449 			     protonum, net, &tuple, l3proto, l4proto)) {
450 		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
451 		return NULL;
452 	}
453 
454 	/* look for tuple match */
455 	h = nf_conntrack_find_get(net, zone, &tuple);
456 	if (!h)
457 		return NULL;   /* Not found. */
458 
459 	ct = nf_ct_tuplehash_to_ctrack(h);
460 
461 	ctinfo = ovs_ct_get_info(h);
462 	if (ctinfo == IP_CT_NEW) {
463 		/* This should not happen. */
464 		WARN_ONCE(1, "ovs_ct_find_existing: new packet for %p\n", ct);
465 	}
466 	skb->nfct = &ct->ct_general;
467 	skb->nfctinfo = ctinfo;
468 	return ct;
469 }
470 
471 /* Determine whether skb->nfct is equal to the result of conntrack lookup. */
472 static bool skb_nfct_cached(struct net *net,
473 			    const struct sw_flow_key *key,
474 			    const struct ovs_conntrack_info *info,
475 			    struct sk_buff *skb)
476 {
477 	enum ip_conntrack_info ctinfo;
478 	struct nf_conn *ct;
479 
480 	ct = nf_ct_get(skb, &ctinfo);
481 	/* If no ct, check if we have evidence that an existing conntrack entry
482 	 * might be found for this skb.  This happens when we lose a skb->nfct
483 	 * due to an upcall.  If the connection was not confirmed, it is not
484 	 * cached and needs to be run through conntrack again.
485 	 */
486 	if (!ct && key->ct.state & OVS_CS_F_TRACKED &&
487 	    !(key->ct.state & OVS_CS_F_INVALID) &&
488 	    key->ct.zone == info->zone.id)
489 		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb);
490 	if (!ct)
491 		return false;
492 	if (!net_eq(net, read_pnet(&ct->ct_net)))
493 		return false;
494 	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
495 		return false;
496 	if (info->helper) {
497 		struct nf_conn_help *help;
498 
499 		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
500 		if (help && rcu_access_pointer(help->helper) != info->helper)
501 			return false;
502 	}
503 
504 	return true;
505 }
506 
507 #ifdef CONFIG_NF_NAT_NEEDED
508 /* Modelled after nf_nat_ipv[46]_fn().
509  * range is only used for new, uninitialized NAT state.
510  * Returns either NF_ACCEPT or NF_DROP.
511  */
512 static int ovs_ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
513 			      enum ip_conntrack_info ctinfo,
514 			      const struct nf_nat_range *range,
515 			      enum nf_nat_manip_type maniptype)
516 {
517 	int hooknum, nh_off, err = NF_ACCEPT;
518 
519 	nh_off = skb_network_offset(skb);
520 	skb_pull(skb, nh_off);
521 
522 	/* See HOOK2MANIP(). */
523 	if (maniptype == NF_NAT_MANIP_SRC)
524 		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
525 	else
526 		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
527 
528 	switch (ctinfo) {
529 	case IP_CT_RELATED:
530 	case IP_CT_RELATED_REPLY:
531 		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
532 		    skb->protocol == htons(ETH_P_IP) &&
533 		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
534 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
535 							   hooknum))
536 				err = NF_DROP;
537 			goto push;
538 		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
539 			   skb->protocol == htons(ETH_P_IPV6)) {
540 			__be16 frag_off;
541 			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
542 			int hdrlen = ipv6_skip_exthdr(skb,
543 						      sizeof(struct ipv6hdr),
544 						      &nexthdr, &frag_off);
545 
546 			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
547 				if (!nf_nat_icmpv6_reply_translation(skb, ct,
548 								     ctinfo,
549 								     hooknum,
550 								     hdrlen))
551 					err = NF_DROP;
552 				goto push;
553 			}
554 		}
555 		/* Non-ICMP, fall thru to initialize if needed. */
556 	case IP_CT_NEW:
557 		/* Seen it before?  This can happen for loopback, retrans,
558 		 * or local packets.
559 		 */
560 		if (!nf_nat_initialized(ct, maniptype)) {
561 			/* Initialize according to the NAT action. */
562 			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
563 				/* Action is set up to establish a new
564 				 * mapping.
565 				 */
566 				? nf_nat_setup_info(ct, range, maniptype)
567 				: nf_nat_alloc_null_binding(ct, hooknum);
568 			if (err != NF_ACCEPT)
569 				goto push;
570 		}
571 		break;
572 
573 	case IP_CT_ESTABLISHED:
574 	case IP_CT_ESTABLISHED_REPLY:
575 		break;
576 
577 	default:
578 		err = NF_DROP;
579 		goto push;
580 	}
581 
582 	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
583 push:
584 	skb_push(skb, nh_off);
585 
586 	return err;
587 }
588 
589 static void ovs_nat_update_key(struct sw_flow_key *key,
590 			       const struct sk_buff *skb,
591 			       enum nf_nat_manip_type maniptype)
592 {
593 	if (maniptype == NF_NAT_MANIP_SRC) {
594 		__be16 src;
595 
596 		key->ct.state |= OVS_CS_F_SRC_NAT;
597 		if (key->eth.type == htons(ETH_P_IP))
598 			key->ipv4.addr.src = ip_hdr(skb)->saddr;
599 		else if (key->eth.type == htons(ETH_P_IPV6))
600 			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
601 			       sizeof(key->ipv6.addr.src));
602 		else
603 			return;
604 
605 		if (key->ip.proto == IPPROTO_UDP)
606 			src = udp_hdr(skb)->source;
607 		else if (key->ip.proto == IPPROTO_TCP)
608 			src = tcp_hdr(skb)->source;
609 		else if (key->ip.proto == IPPROTO_SCTP)
610 			src = sctp_hdr(skb)->source;
611 		else
612 			return;
613 
614 		key->tp.src = src;
615 	} else {
616 		__be16 dst;
617 
618 		key->ct.state |= OVS_CS_F_DST_NAT;
619 		if (key->eth.type == htons(ETH_P_IP))
620 			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
621 		else if (key->eth.type == htons(ETH_P_IPV6))
622 			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
623 			       sizeof(key->ipv6.addr.dst));
624 		else
625 			return;
626 
627 		if (key->ip.proto == IPPROTO_UDP)
628 			dst = udp_hdr(skb)->dest;
629 		else if (key->ip.proto == IPPROTO_TCP)
630 			dst = tcp_hdr(skb)->dest;
631 		else if (key->ip.proto == IPPROTO_SCTP)
632 			dst = sctp_hdr(skb)->dest;
633 		else
634 			return;
635 
636 		key->tp.dst = dst;
637 	}
638 }
639 
640 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
641 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
642 		      const struct ovs_conntrack_info *info,
643 		      struct sk_buff *skb, struct nf_conn *ct,
644 		      enum ip_conntrack_info ctinfo)
645 {
646 	enum nf_nat_manip_type maniptype;
647 	int err;
648 
649 	if (nf_ct_is_untracked(ct)) {
650 		/* A NAT action may only be performed on tracked packets. */
651 		return NF_ACCEPT;
652 	}
653 
654 	/* Add NAT extension if not confirmed yet. */
655 	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
656 		return NF_ACCEPT;   /* Can't NAT. */
657 
658 	/* Determine NAT type.
659 	 * Check if the NAT type can be deduced from the tracked connection.
660 	 * Make sure new expected connections (IP_CT_RELATED) are NATted only
661 	 * when committing.
662 	 */
663 	if (info->nat & OVS_CT_NAT && ctinfo != IP_CT_NEW &&
664 	    ct->status & IPS_NAT_MASK &&
665 	    (ctinfo != IP_CT_RELATED || info->commit)) {
666 		/* NAT an established or related connection like before. */
667 		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
668 			/* This is the REPLY direction for a connection
669 			 * for which NAT was applied in the forward
670 			 * direction.  Do the reverse NAT.
671 			 */
672 			maniptype = ct->status & IPS_SRC_NAT
673 				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
674 		else
675 			maniptype = ct->status & IPS_SRC_NAT
676 				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
677 	} else if (info->nat & OVS_CT_SRC_NAT) {
678 		maniptype = NF_NAT_MANIP_SRC;
679 	} else if (info->nat & OVS_CT_DST_NAT) {
680 		maniptype = NF_NAT_MANIP_DST;
681 	} else {
682 		return NF_ACCEPT; /* Connection is not NATed. */
683 	}
684 	err = ovs_ct_nat_execute(skb, ct, ctinfo, &info->range, maniptype);
685 
686 	/* Mark NAT done if successful and update the flow key. */
687 	if (err == NF_ACCEPT)
688 		ovs_nat_update_key(key, skb, maniptype);
689 
690 	return err;
691 }
692 #else /* !CONFIG_NF_NAT_NEEDED */
693 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
694 		      const struct ovs_conntrack_info *info,
695 		      struct sk_buff *skb, struct nf_conn *ct,
696 		      enum ip_conntrack_info ctinfo)
697 {
698 	return NF_ACCEPT;
699 }
700 #endif
701 
702 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
703  * not done already.  Update key with new CT state after passing the packet
704  * through conntrack.
705  * Note that if the packet is deemed invalid by conntrack, skb->nfct will be
706  * set to NULL and 0 will be returned.
707  */
708 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
709 			   const struct ovs_conntrack_info *info,
710 			   struct sk_buff *skb)
711 {
712 	/* If we are recirculating packets to match on conntrack fields and
713 	 * committing with a separate conntrack action,  then we don't need to
714 	 * actually run the packet through conntrack twice unless it's for a
715 	 * different zone.
716 	 */
717 	bool cached = skb_nfct_cached(net, key, info, skb);
718 	enum ip_conntrack_info ctinfo;
719 	struct nf_conn *ct;
720 
721 	if (!cached) {
722 		struct nf_conn *tmpl = info->ct;
723 		int err;
724 
725 		/* Associate skb with specified zone. */
726 		if (tmpl) {
727 			if (skb->nfct)
728 				nf_conntrack_put(skb->nfct);
729 			nf_conntrack_get(&tmpl->ct_general);
730 			skb->nfct = &tmpl->ct_general;
731 			skb->nfctinfo = IP_CT_NEW;
732 		}
733 
734 		/* Repeat if requested, see nf_iterate(). */
735 		do {
736 			err = nf_conntrack_in(net, info->family,
737 					      NF_INET_PRE_ROUTING, skb);
738 		} while (err == NF_REPEAT);
739 
740 		if (err != NF_ACCEPT)
741 			return -ENOENT;
742 
743 		/* Clear CT state NAT flags to mark that we have not yet done
744 		 * NAT after the nf_conntrack_in() call.  We can actually clear
745 		 * the whole state, as it will be re-initialized below.
746 		 */
747 		key->ct.state = 0;
748 
749 		/* Update the key, but keep the NAT flags. */
750 		ovs_ct_update_key(skb, info, key, true, true);
751 	}
752 
753 	ct = nf_ct_get(skb, &ctinfo);
754 	if (ct) {
755 		/* Packets starting a new connection must be NATted before the
756 		 * helper, so that the helper knows about the NAT.  We enforce
757 		 * this by delaying both NAT and helper calls for unconfirmed
758 		 * connections until the committing CT action.  For later
759 		 * packets NAT and Helper may be called in either order.
760 		 *
761 		 * NAT will be done only if the CT action has NAT, and only
762 		 * once per packet (per zone), as guarded by the NAT bits in
763 		 * the key->ct.state.
764 		 */
765 		if (info->nat && !(key->ct.state & OVS_CS_F_NAT_MASK) &&
766 		    (nf_ct_is_confirmed(ct) || info->commit) &&
767 		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
768 			return -EINVAL;
769 		}
770 
771 		/* Userspace may decide to perform a ct lookup without a helper
772 		 * specified followed by a (recirculate and) commit with one.
773 		 * Therefore, for unconfirmed connections which we will commit,
774 		 * we need to attach the helper here.
775 		 */
776 		if (!nf_ct_is_confirmed(ct) && info->commit &&
777 		    info->helper && !nfct_help(ct)) {
778 			int err = __nf_ct_try_assign_helper(ct, info->ct,
779 							    GFP_ATOMIC);
780 			if (err)
781 				return err;
782 		}
783 
784 		/* Call the helper only if:
785 		 * - nf_conntrack_in() was executed above ("!cached") for a
786 		 *   confirmed connection, or
787 		 * - When committing an unconfirmed connection.
788 		 */
789 		if ((nf_ct_is_confirmed(ct) ? !cached : info->commit) &&
790 		    ovs_ct_helper(skb, info->family) != NF_ACCEPT) {
791 			return -EINVAL;
792 		}
793 	}
794 
795 	return 0;
796 }
797 
798 /* Lookup connection and read fields into key. */
799 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
800 			 const struct ovs_conntrack_info *info,
801 			 struct sk_buff *skb)
802 {
803 	struct nf_conntrack_expect *exp;
804 
805 	/* If we pass an expected packet through nf_conntrack_in() the
806 	 * expectation is typically removed, but the packet could still be
807 	 * lost in upcall processing.  To prevent this from happening we
808 	 * perform an explicit expectation lookup.  Expected connections are
809 	 * always new, and will be passed through conntrack only when they are
810 	 * committed, as it is OK to remove the expectation at that time.
811 	 */
812 	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
813 	if (exp) {
814 		u8 state;
815 
816 		/* NOTE: New connections are NATted and Helped only when
817 		 * committed, so we are not calling into NAT here.
818 		 */
819 		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
820 		__ovs_ct_update_key(key, state, &info->zone, exp->master);
821 	} else
822 		return __ovs_ct_lookup(net, key, info, skb);
823 
824 	return 0;
825 }
826 
827 /* Lookup connection and confirm if unconfirmed. */
828 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
829 			 const struct ovs_conntrack_info *info,
830 			 struct sk_buff *skb)
831 {
832 	int err;
833 
834 	err = __ovs_ct_lookup(net, key, info, skb);
835 	if (err)
836 		return err;
837 	/* This is a no-op if the connection has already been confirmed. */
838 	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
839 		return -EINVAL;
840 
841 	return 0;
842 }
843 
844 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
845 {
846 	size_t i;
847 
848 	for (i = 0; i < sizeof(*labels); i++)
849 		if (labels->ct_labels[i])
850 			return true;
851 
852 	return false;
853 }
854 
855 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
856  * value if 'skb' is freed.
857  */
858 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
859 		   struct sw_flow_key *key,
860 		   const struct ovs_conntrack_info *info)
861 {
862 	int nh_ofs;
863 	int err;
864 
865 	/* The conntrack module expects to be working at L3. */
866 	nh_ofs = skb_network_offset(skb);
867 	skb_pull(skb, nh_ofs);
868 
869 	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
870 		err = handle_fragments(net, key, info->zone.id, skb);
871 		if (err)
872 			return err;
873 	}
874 
875 	if (info->commit)
876 		err = ovs_ct_commit(net, key, info, skb);
877 	else
878 		err = ovs_ct_lookup(net, key, info, skb);
879 	if (err)
880 		goto err;
881 
882 	if (info->mark.mask) {
883 		err = ovs_ct_set_mark(skb, key, info->mark.value,
884 				      info->mark.mask);
885 		if (err)
886 			goto err;
887 	}
888 	if (labels_nonzero(&info->labels.mask))
889 		err = ovs_ct_set_labels(skb, key, &info->labels.value,
890 					&info->labels.mask);
891 err:
892 	skb_push(skb, nh_ofs);
893 	if (err)
894 		kfree_skb(skb);
895 	return err;
896 }
897 
898 static int ovs_ct_add_helper(struct ovs_conntrack_info *info, const char *name,
899 			     const struct sw_flow_key *key, bool log)
900 {
901 	struct nf_conntrack_helper *helper;
902 	struct nf_conn_help *help;
903 
904 	helper = nf_conntrack_helper_try_module_get(name, info->family,
905 						    key->ip.proto);
906 	if (!helper) {
907 		OVS_NLERR(log, "Unknown helper \"%s\"", name);
908 		return -EINVAL;
909 	}
910 
911 	help = nf_ct_helper_ext_add(info->ct, helper, GFP_KERNEL);
912 	if (!help) {
913 		module_put(helper->me);
914 		return -ENOMEM;
915 	}
916 
917 	rcu_assign_pointer(help->helper, helper);
918 	info->helper = helper;
919 	return 0;
920 }
921 
922 #ifdef CONFIG_NF_NAT_NEEDED
923 static int parse_nat(const struct nlattr *attr,
924 		     struct ovs_conntrack_info *info, bool log)
925 {
926 	struct nlattr *a;
927 	int rem;
928 	bool have_ip_max = false;
929 	bool have_proto_max = false;
930 	bool ip_vers = (info->family == NFPROTO_IPV6);
931 
932 	nla_for_each_nested(a, attr, rem) {
933 		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
934 			[OVS_NAT_ATTR_SRC] = {0, 0},
935 			[OVS_NAT_ATTR_DST] = {0, 0},
936 			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
937 						 sizeof(struct in6_addr)},
938 			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
939 						 sizeof(struct in6_addr)},
940 			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
941 			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
942 			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
943 			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
944 			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
945 		};
946 		int type = nla_type(a);
947 
948 		if (type > OVS_NAT_ATTR_MAX) {
949 			OVS_NLERR(log,
950 				  "Unknown NAT attribute (type=%d, max=%d).\n",
951 				  type, OVS_NAT_ATTR_MAX);
952 			return -EINVAL;
953 		}
954 
955 		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
956 			OVS_NLERR(log,
957 				  "NAT attribute type %d has unexpected length (%d != %d).\n",
958 				  type, nla_len(a),
959 				  ovs_nat_attr_lens[type][ip_vers]);
960 			return -EINVAL;
961 		}
962 
963 		switch (type) {
964 		case OVS_NAT_ATTR_SRC:
965 		case OVS_NAT_ATTR_DST:
966 			if (info->nat) {
967 				OVS_NLERR(log,
968 					  "Only one type of NAT may be specified.\n"
969 					  );
970 				return -ERANGE;
971 			}
972 			info->nat |= OVS_CT_NAT;
973 			info->nat |= ((type == OVS_NAT_ATTR_SRC)
974 					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
975 			break;
976 
977 		case OVS_NAT_ATTR_IP_MIN:
978 			nla_memcpy(&info->range.min_addr, a,
979 				   sizeof(info->range.min_addr));
980 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
981 			break;
982 
983 		case OVS_NAT_ATTR_IP_MAX:
984 			have_ip_max = true;
985 			nla_memcpy(&info->range.max_addr, a,
986 				   sizeof(info->range.max_addr));
987 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
988 			break;
989 
990 		case OVS_NAT_ATTR_PROTO_MIN:
991 			info->range.min_proto.all = htons(nla_get_u16(a));
992 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
993 			break;
994 
995 		case OVS_NAT_ATTR_PROTO_MAX:
996 			have_proto_max = true;
997 			info->range.max_proto.all = htons(nla_get_u16(a));
998 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
999 			break;
1000 
1001 		case OVS_NAT_ATTR_PERSISTENT:
1002 			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1003 			break;
1004 
1005 		case OVS_NAT_ATTR_PROTO_HASH:
1006 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1007 			break;
1008 
1009 		case OVS_NAT_ATTR_PROTO_RANDOM:
1010 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1011 			break;
1012 
1013 		default:
1014 			OVS_NLERR(log, "Unknown nat attribute (%d).\n", type);
1015 			return -EINVAL;
1016 		}
1017 	}
1018 
1019 	if (rem > 0) {
1020 		OVS_NLERR(log, "NAT attribute has %d unknown bytes.\n", rem);
1021 		return -EINVAL;
1022 	}
1023 	if (!info->nat) {
1024 		/* Do not allow flags if no type is given. */
1025 		if (info->range.flags) {
1026 			OVS_NLERR(log,
1027 				  "NAT flags may be given only when NAT range (SRC or DST) is also specified.\n"
1028 				  );
1029 			return -EINVAL;
1030 		}
1031 		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1032 	} else if (!info->commit) {
1033 		OVS_NLERR(log,
1034 			  "NAT attributes may be specified only when CT COMMIT flag is also specified.\n"
1035 			  );
1036 		return -EINVAL;
1037 	}
1038 	/* Allow missing IP_MAX. */
1039 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1040 		memcpy(&info->range.max_addr, &info->range.min_addr,
1041 		       sizeof(info->range.max_addr));
1042 	}
1043 	/* Allow missing PROTO_MAX. */
1044 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1045 	    !have_proto_max) {
1046 		info->range.max_proto.all = info->range.min_proto.all;
1047 	}
1048 	return 0;
1049 }
1050 #endif
1051 
1052 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1053 	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1054 	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
1055 				    .maxlen = sizeof(u16) },
1056 	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
1057 				    .maxlen = sizeof(struct md_mark) },
1058 	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
1059 				    .maxlen = sizeof(struct md_labels) },
1060 	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
1061 				    .maxlen = NF_CT_HELPER_NAME_LEN },
1062 #ifdef CONFIG_NF_NAT_NEEDED
1063 	/* NAT length is checked when parsing the nested attributes. */
1064 	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
1065 #endif
1066 };
1067 
1068 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1069 		    const char **helper, bool log)
1070 {
1071 	struct nlattr *a;
1072 	int rem;
1073 
1074 	nla_for_each_nested(a, attr, rem) {
1075 		int type = nla_type(a);
1076 		int maxlen = ovs_ct_attr_lens[type].maxlen;
1077 		int minlen = ovs_ct_attr_lens[type].minlen;
1078 
1079 		if (type > OVS_CT_ATTR_MAX) {
1080 			OVS_NLERR(log,
1081 				  "Unknown conntrack attr (type=%d, max=%d)",
1082 				  type, OVS_CT_ATTR_MAX);
1083 			return -EINVAL;
1084 		}
1085 		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1086 			OVS_NLERR(log,
1087 				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1088 				  type, nla_len(a), maxlen);
1089 			return -EINVAL;
1090 		}
1091 
1092 		switch (type) {
1093 		case OVS_CT_ATTR_COMMIT:
1094 			info->commit = true;
1095 			break;
1096 #ifdef CONFIG_NF_CONNTRACK_ZONES
1097 		case OVS_CT_ATTR_ZONE:
1098 			info->zone.id = nla_get_u16(a);
1099 			break;
1100 #endif
1101 #ifdef CONFIG_NF_CONNTRACK_MARK
1102 		case OVS_CT_ATTR_MARK: {
1103 			struct md_mark *mark = nla_data(a);
1104 
1105 			if (!mark->mask) {
1106 				OVS_NLERR(log, "ct_mark mask cannot be 0");
1107 				return -EINVAL;
1108 			}
1109 			info->mark = *mark;
1110 			break;
1111 		}
1112 #endif
1113 #ifdef CONFIG_NF_CONNTRACK_LABELS
1114 		case OVS_CT_ATTR_LABELS: {
1115 			struct md_labels *labels = nla_data(a);
1116 
1117 			if (!labels_nonzero(&labels->mask)) {
1118 				OVS_NLERR(log, "ct_labels mask cannot be 0");
1119 				return -EINVAL;
1120 			}
1121 			info->labels = *labels;
1122 			break;
1123 		}
1124 #endif
1125 		case OVS_CT_ATTR_HELPER:
1126 			*helper = nla_data(a);
1127 			if (!memchr(*helper, '\0', nla_len(a))) {
1128 				OVS_NLERR(log, "Invalid conntrack helper");
1129 				return -EINVAL;
1130 			}
1131 			break;
1132 #ifdef CONFIG_NF_NAT_NEEDED
1133 		case OVS_CT_ATTR_NAT: {
1134 			int err = parse_nat(a, info, log);
1135 
1136 			if (err)
1137 				return err;
1138 			break;
1139 		}
1140 #endif
1141 		default:
1142 			OVS_NLERR(log, "Unknown conntrack attr (%d)",
1143 				  type);
1144 			return -EINVAL;
1145 		}
1146 	}
1147 
1148 	if (rem > 0) {
1149 		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1150 		return -EINVAL;
1151 	}
1152 
1153 	return 0;
1154 }
1155 
1156 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1157 {
1158 	if (attr == OVS_KEY_ATTR_CT_STATE)
1159 		return true;
1160 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1161 	    attr == OVS_KEY_ATTR_CT_ZONE)
1162 		return true;
1163 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1164 	    attr == OVS_KEY_ATTR_CT_MARK)
1165 		return true;
1166 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1167 	    attr == OVS_KEY_ATTR_CT_LABELS) {
1168 		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1169 
1170 		return ovs_net->xt_label;
1171 	}
1172 
1173 	return false;
1174 }
1175 
1176 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1177 		       const struct sw_flow_key *key,
1178 		       struct sw_flow_actions **sfa,  bool log)
1179 {
1180 	struct ovs_conntrack_info ct_info;
1181 	const char *helper = NULL;
1182 	u16 family;
1183 	int err;
1184 
1185 	family = key_to_nfproto(key);
1186 	if (family == NFPROTO_UNSPEC) {
1187 		OVS_NLERR(log, "ct family unspecified");
1188 		return -EINVAL;
1189 	}
1190 
1191 	memset(&ct_info, 0, sizeof(ct_info));
1192 	ct_info.family = family;
1193 
1194 	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1195 			NF_CT_DEFAULT_ZONE_DIR, 0);
1196 
1197 	err = parse_ct(attr, &ct_info, &helper, log);
1198 	if (err)
1199 		return err;
1200 
1201 	/* Set up template for tracking connections in specific zones. */
1202 	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1203 	if (!ct_info.ct) {
1204 		OVS_NLERR(log, "Failed to allocate conntrack template");
1205 		return -ENOMEM;
1206 	}
1207 
1208 	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1209 	nf_conntrack_get(&ct_info.ct->ct_general);
1210 
1211 	if (helper) {
1212 		err = ovs_ct_add_helper(&ct_info, helper, key, log);
1213 		if (err)
1214 			goto err_free_ct;
1215 	}
1216 
1217 	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1218 				 sizeof(ct_info), log);
1219 	if (err)
1220 		goto err_free_ct;
1221 
1222 	return 0;
1223 err_free_ct:
1224 	__ovs_ct_free_action(&ct_info);
1225 	return err;
1226 }
1227 
1228 #ifdef CONFIG_NF_NAT_NEEDED
1229 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1230 			       struct sk_buff *skb)
1231 {
1232 	struct nlattr *start;
1233 
1234 	start = nla_nest_start(skb, OVS_CT_ATTR_NAT);
1235 	if (!start)
1236 		return false;
1237 
1238 	if (info->nat & OVS_CT_SRC_NAT) {
1239 		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1240 			return false;
1241 	} else if (info->nat & OVS_CT_DST_NAT) {
1242 		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1243 			return false;
1244 	} else {
1245 		goto out;
1246 	}
1247 
1248 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1249 		if (IS_ENABLED(CONFIG_NF_NAT_IPV4) &&
1250 		    info->family == NFPROTO_IPV4) {
1251 			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1252 					    info->range.min_addr.ip) ||
1253 			    (info->range.max_addr.ip
1254 			     != info->range.min_addr.ip &&
1255 			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1256 					      info->range.max_addr.ip))))
1257 				return false;
1258 		} else if (IS_ENABLED(CONFIG_NF_NAT_IPV6) &&
1259 			   info->family == NFPROTO_IPV6) {
1260 			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1261 					     &info->range.min_addr.in6) ||
1262 			    (memcmp(&info->range.max_addr.in6,
1263 				    &info->range.min_addr.in6,
1264 				    sizeof(info->range.max_addr.in6)) &&
1265 			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1266 					       &info->range.max_addr.in6))))
1267 				return false;
1268 		} else {
1269 			return false;
1270 		}
1271 	}
1272 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1273 	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1274 			 ntohs(info->range.min_proto.all)) ||
1275 	     (info->range.max_proto.all != info->range.min_proto.all &&
1276 	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1277 			  ntohs(info->range.max_proto.all)))))
1278 		return false;
1279 
1280 	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1281 	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1282 		return false;
1283 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1284 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1285 		return false;
1286 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1287 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1288 		return false;
1289 out:
1290 	nla_nest_end(skb, start);
1291 
1292 	return true;
1293 }
1294 #endif
1295 
1296 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1297 			  struct sk_buff *skb)
1298 {
1299 	struct nlattr *start;
1300 
1301 	start = nla_nest_start(skb, OVS_ACTION_ATTR_CT);
1302 	if (!start)
1303 		return -EMSGSIZE;
1304 
1305 	if (ct_info->commit && nla_put_flag(skb, OVS_CT_ATTR_COMMIT))
1306 		return -EMSGSIZE;
1307 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1308 	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1309 		return -EMSGSIZE;
1310 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1311 	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1312 		    &ct_info->mark))
1313 		return -EMSGSIZE;
1314 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1315 	    labels_nonzero(&ct_info->labels.mask) &&
1316 	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1317 		    &ct_info->labels))
1318 		return -EMSGSIZE;
1319 	if (ct_info->helper) {
1320 		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1321 				   ct_info->helper->name))
1322 			return -EMSGSIZE;
1323 	}
1324 #ifdef CONFIG_NF_NAT_NEEDED
1325 	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1326 		return -EMSGSIZE;
1327 #endif
1328 	nla_nest_end(skb, start);
1329 
1330 	return 0;
1331 }
1332 
1333 void ovs_ct_free_action(const struct nlattr *a)
1334 {
1335 	struct ovs_conntrack_info *ct_info = nla_data(a);
1336 
1337 	__ovs_ct_free_action(ct_info);
1338 }
1339 
1340 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1341 {
1342 	if (ct_info->helper)
1343 		module_put(ct_info->helper->me);
1344 	if (ct_info->ct)
1345 		nf_ct_put(ct_info->ct);
1346 }
1347 
1348 void ovs_ct_init(struct net *net)
1349 {
1350 	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
1351 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1352 
1353 	if (nf_connlabels_get(net, n_bits - 1)) {
1354 		ovs_net->xt_label = false;
1355 		OVS_NLERR(true, "Failed to set connlabel length");
1356 	} else {
1357 		ovs_net->xt_label = true;
1358 	}
1359 }
1360 
1361 void ovs_ct_exit(struct net *net)
1362 {
1363 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1364 
1365 	if (ovs_net->xt_label)
1366 		nf_connlabels_put(net);
1367 }
1368