xref: /openbmc/linux/net/openvswitch/conntrack.c (revision 497e6b37)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2015 Nicira, Inc.
4  */
5 
6 #include <linux/module.h>
7 #include <linux/openvswitch.h>
8 #include <linux/tcp.h>
9 #include <linux/udp.h>
10 #include <linux/sctp.h>
11 #include <linux/static_key.h>
12 #include <net/ip.h>
13 #include <net/genetlink.h>
14 #include <net/netfilter/nf_conntrack_core.h>
15 #include <net/netfilter/nf_conntrack_count.h>
16 #include <net/netfilter/nf_conntrack_helper.h>
17 #include <net/netfilter/nf_conntrack_labels.h>
18 #include <net/netfilter/nf_conntrack_seqadj.h>
19 #include <net/netfilter/nf_conntrack_timeout.h>
20 #include <net/netfilter/nf_conntrack_zones.h>
21 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
22 #include <net/ipv6_frag.h>
23 
24 #if IS_ENABLED(CONFIG_NF_NAT)
25 #include <net/netfilter/nf_nat.h>
26 #endif
27 
28 #include <net/netfilter/nf_conntrack_act_ct.h>
29 
30 #include "datapath.h"
31 #include "conntrack.h"
32 #include "flow.h"
33 #include "flow_netlink.h"
34 
35 struct ovs_ct_len_tbl {
36 	int maxlen;
37 	int minlen;
38 };
39 
40 /* Metadata mark for masked write to conntrack mark */
41 struct md_mark {
42 	u32 value;
43 	u32 mask;
44 };
45 
46 /* Metadata label for masked write to conntrack label. */
47 struct md_labels {
48 	struct ovs_key_ct_labels value;
49 	struct ovs_key_ct_labels mask;
50 };
51 
52 enum ovs_ct_nat {
53 	OVS_CT_NAT = 1 << 0,     /* NAT for committed connections only. */
54 	OVS_CT_SRC_NAT = 1 << 1, /* Source NAT for NEW connections. */
55 	OVS_CT_DST_NAT = 1 << 2, /* Destination NAT for NEW connections. */
56 };
57 
58 /* Conntrack action context for execution. */
59 struct ovs_conntrack_info {
60 	struct nf_conntrack_helper *helper;
61 	struct nf_conntrack_zone zone;
62 	struct nf_conn *ct;
63 	u8 commit : 1;
64 	u8 nat : 3;                 /* enum ovs_ct_nat */
65 	u8 force : 1;
66 	u8 have_eventmask : 1;
67 	u16 family;
68 	u32 eventmask;              /* Mask of 1 << IPCT_*. */
69 	struct md_mark mark;
70 	struct md_labels labels;
71 	char timeout[CTNL_TIMEOUT_NAME_MAX];
72 	struct nf_ct_timeout *nf_ct_timeout;
73 #if IS_ENABLED(CONFIG_NF_NAT)
74 	struct nf_nat_range2 range;  /* Only present for SRC NAT and DST NAT. */
75 #endif
76 };
77 
78 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
79 #define OVS_CT_LIMIT_UNLIMITED	0
80 #define OVS_CT_LIMIT_DEFAULT OVS_CT_LIMIT_UNLIMITED
81 #define CT_LIMIT_HASH_BUCKETS 512
82 static DEFINE_STATIC_KEY_FALSE(ovs_ct_limit_enabled);
83 
84 struct ovs_ct_limit {
85 	/* Elements in ovs_ct_limit_info->limits hash table */
86 	struct hlist_node hlist_node;
87 	struct rcu_head rcu;
88 	u16 zone;
89 	u32 limit;
90 };
91 
92 struct ovs_ct_limit_info {
93 	u32 default_limit;
94 	struct hlist_head *limits;
95 	struct nf_conncount_data *data;
96 };
97 
98 static const struct nla_policy ct_limit_policy[OVS_CT_LIMIT_ATTR_MAX + 1] = {
99 	[OVS_CT_LIMIT_ATTR_ZONE_LIMIT] = { .type = NLA_NESTED, },
100 };
101 #endif
102 
103 static bool labels_nonzero(const struct ovs_key_ct_labels *labels);
104 
105 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info);
106 
107 static u16 key_to_nfproto(const struct sw_flow_key *key)
108 {
109 	switch (ntohs(key->eth.type)) {
110 	case ETH_P_IP:
111 		return NFPROTO_IPV4;
112 	case ETH_P_IPV6:
113 		return NFPROTO_IPV6;
114 	default:
115 		return NFPROTO_UNSPEC;
116 	}
117 }
118 
119 /* Map SKB connection state into the values used by flow definition. */
120 static u8 ovs_ct_get_state(enum ip_conntrack_info ctinfo)
121 {
122 	u8 ct_state = OVS_CS_F_TRACKED;
123 
124 	switch (ctinfo) {
125 	case IP_CT_ESTABLISHED_REPLY:
126 	case IP_CT_RELATED_REPLY:
127 		ct_state |= OVS_CS_F_REPLY_DIR;
128 		break;
129 	default:
130 		break;
131 	}
132 
133 	switch (ctinfo) {
134 	case IP_CT_ESTABLISHED:
135 	case IP_CT_ESTABLISHED_REPLY:
136 		ct_state |= OVS_CS_F_ESTABLISHED;
137 		break;
138 	case IP_CT_RELATED:
139 	case IP_CT_RELATED_REPLY:
140 		ct_state |= OVS_CS_F_RELATED;
141 		break;
142 	case IP_CT_NEW:
143 		ct_state |= OVS_CS_F_NEW;
144 		break;
145 	default:
146 		break;
147 	}
148 
149 	return ct_state;
150 }
151 
152 static u32 ovs_ct_get_mark(const struct nf_conn *ct)
153 {
154 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
155 	return ct ? READ_ONCE(ct->mark) : 0;
156 #else
157 	return 0;
158 #endif
159 }
160 
161 /* Guard against conntrack labels max size shrinking below 128 bits. */
162 #if NF_CT_LABELS_MAX_SIZE < 16
163 #error NF_CT_LABELS_MAX_SIZE must be at least 16 bytes
164 #endif
165 
166 static void ovs_ct_get_labels(const struct nf_conn *ct,
167 			      struct ovs_key_ct_labels *labels)
168 {
169 	struct nf_conn_labels *cl = ct ? nf_ct_labels_find(ct) : NULL;
170 
171 	if (cl)
172 		memcpy(labels, cl->bits, OVS_CT_LABELS_LEN);
173 	else
174 		memset(labels, 0, OVS_CT_LABELS_LEN);
175 }
176 
177 static void __ovs_ct_update_key_orig_tp(struct sw_flow_key *key,
178 					const struct nf_conntrack_tuple *orig,
179 					u8 icmp_proto)
180 {
181 	key->ct_orig_proto = orig->dst.protonum;
182 	if (orig->dst.protonum == icmp_proto) {
183 		key->ct.orig_tp.src = htons(orig->dst.u.icmp.type);
184 		key->ct.orig_tp.dst = htons(orig->dst.u.icmp.code);
185 	} else {
186 		key->ct.orig_tp.src = orig->src.u.all;
187 		key->ct.orig_tp.dst = orig->dst.u.all;
188 	}
189 }
190 
191 static void __ovs_ct_update_key(struct sw_flow_key *key, u8 state,
192 				const struct nf_conntrack_zone *zone,
193 				const struct nf_conn *ct)
194 {
195 	key->ct_state = state;
196 	key->ct_zone = zone->id;
197 	key->ct.mark = ovs_ct_get_mark(ct);
198 	ovs_ct_get_labels(ct, &key->ct.labels);
199 
200 	if (ct) {
201 		const struct nf_conntrack_tuple *orig;
202 
203 		/* Use the master if we have one. */
204 		if (ct->master)
205 			ct = ct->master;
206 		orig = &ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple;
207 
208 		/* IP version must match with the master connection. */
209 		if (key->eth.type == htons(ETH_P_IP) &&
210 		    nf_ct_l3num(ct) == NFPROTO_IPV4) {
211 			key->ipv4.ct_orig.src = orig->src.u3.ip;
212 			key->ipv4.ct_orig.dst = orig->dst.u3.ip;
213 			__ovs_ct_update_key_orig_tp(key, orig, IPPROTO_ICMP);
214 			return;
215 		} else if (key->eth.type == htons(ETH_P_IPV6) &&
216 			   !sw_flow_key_is_nd(key) &&
217 			   nf_ct_l3num(ct) == NFPROTO_IPV6) {
218 			key->ipv6.ct_orig.src = orig->src.u3.in6;
219 			key->ipv6.ct_orig.dst = orig->dst.u3.in6;
220 			__ovs_ct_update_key_orig_tp(key, orig, NEXTHDR_ICMP);
221 			return;
222 		}
223 	}
224 	/* Clear 'ct_orig_proto' to mark the non-existence of conntrack
225 	 * original direction key fields.
226 	 */
227 	key->ct_orig_proto = 0;
228 }
229 
230 /* Update 'key' based on skb->_nfct.  If 'post_ct' is true, then OVS has
231  * previously sent the packet to conntrack via the ct action.  If
232  * 'keep_nat_flags' is true, the existing NAT flags retained, else they are
233  * initialized from the connection status.
234  */
235 static void ovs_ct_update_key(const struct sk_buff *skb,
236 			      const struct ovs_conntrack_info *info,
237 			      struct sw_flow_key *key, bool post_ct,
238 			      bool keep_nat_flags)
239 {
240 	const struct nf_conntrack_zone *zone = &nf_ct_zone_dflt;
241 	enum ip_conntrack_info ctinfo;
242 	struct nf_conn *ct;
243 	u8 state = 0;
244 
245 	ct = nf_ct_get(skb, &ctinfo);
246 	if (ct) {
247 		state = ovs_ct_get_state(ctinfo);
248 		/* All unconfirmed entries are NEW connections. */
249 		if (!nf_ct_is_confirmed(ct))
250 			state |= OVS_CS_F_NEW;
251 		/* OVS persists the related flag for the duration of the
252 		 * connection.
253 		 */
254 		if (ct->master)
255 			state |= OVS_CS_F_RELATED;
256 		if (keep_nat_flags) {
257 			state |= key->ct_state & OVS_CS_F_NAT_MASK;
258 		} else {
259 			if (ct->status & IPS_SRC_NAT)
260 				state |= OVS_CS_F_SRC_NAT;
261 			if (ct->status & IPS_DST_NAT)
262 				state |= OVS_CS_F_DST_NAT;
263 		}
264 		zone = nf_ct_zone(ct);
265 	} else if (post_ct) {
266 		state = OVS_CS_F_TRACKED | OVS_CS_F_INVALID;
267 		if (info)
268 			zone = &info->zone;
269 	}
270 	__ovs_ct_update_key(key, state, zone, ct);
271 }
272 
273 /* This is called to initialize CT key fields possibly coming in from the local
274  * stack.
275  */
276 void ovs_ct_fill_key(const struct sk_buff *skb,
277 		     struct sw_flow_key *key,
278 		     bool post_ct)
279 {
280 	ovs_ct_update_key(skb, NULL, key, post_ct, false);
281 }
282 
283 int ovs_ct_put_key(const struct sw_flow_key *swkey,
284 		   const struct sw_flow_key *output, struct sk_buff *skb)
285 {
286 	if (nla_put_u32(skb, OVS_KEY_ATTR_CT_STATE, output->ct_state))
287 		return -EMSGSIZE;
288 
289 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
290 	    nla_put_u16(skb, OVS_KEY_ATTR_CT_ZONE, output->ct_zone))
291 		return -EMSGSIZE;
292 
293 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
294 	    nla_put_u32(skb, OVS_KEY_ATTR_CT_MARK, output->ct.mark))
295 		return -EMSGSIZE;
296 
297 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
298 	    nla_put(skb, OVS_KEY_ATTR_CT_LABELS, sizeof(output->ct.labels),
299 		    &output->ct.labels))
300 		return -EMSGSIZE;
301 
302 	if (swkey->ct_orig_proto) {
303 		if (swkey->eth.type == htons(ETH_P_IP)) {
304 			struct ovs_key_ct_tuple_ipv4 orig;
305 
306 			memset(&orig, 0, sizeof(orig));
307 			orig.ipv4_src = output->ipv4.ct_orig.src;
308 			orig.ipv4_dst = output->ipv4.ct_orig.dst;
309 			orig.src_port = output->ct.orig_tp.src;
310 			orig.dst_port = output->ct.orig_tp.dst;
311 			orig.ipv4_proto = output->ct_orig_proto;
312 
313 			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV4,
314 				    sizeof(orig), &orig))
315 				return -EMSGSIZE;
316 		} else if (swkey->eth.type == htons(ETH_P_IPV6)) {
317 			struct ovs_key_ct_tuple_ipv6 orig;
318 
319 			memset(&orig, 0, sizeof(orig));
320 			memcpy(orig.ipv6_src, output->ipv6.ct_orig.src.s6_addr32,
321 			       sizeof(orig.ipv6_src));
322 			memcpy(orig.ipv6_dst, output->ipv6.ct_orig.dst.s6_addr32,
323 			       sizeof(orig.ipv6_dst));
324 			orig.src_port = output->ct.orig_tp.src;
325 			orig.dst_port = output->ct.orig_tp.dst;
326 			orig.ipv6_proto = output->ct_orig_proto;
327 
328 			if (nla_put(skb, OVS_KEY_ATTR_CT_ORIG_TUPLE_IPV6,
329 				    sizeof(orig), &orig))
330 				return -EMSGSIZE;
331 		}
332 	}
333 
334 	return 0;
335 }
336 
337 static int ovs_ct_set_mark(struct nf_conn *ct, struct sw_flow_key *key,
338 			   u32 ct_mark, u32 mask)
339 {
340 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
341 	u32 new_mark;
342 
343 	new_mark = ct_mark | (READ_ONCE(ct->mark) & ~(mask));
344 	if (READ_ONCE(ct->mark) != new_mark) {
345 		WRITE_ONCE(ct->mark, new_mark);
346 		if (nf_ct_is_confirmed(ct))
347 			nf_conntrack_event_cache(IPCT_MARK, ct);
348 		key->ct.mark = new_mark;
349 	}
350 
351 	return 0;
352 #else
353 	return -ENOTSUPP;
354 #endif
355 }
356 
357 static struct nf_conn_labels *ovs_ct_get_conn_labels(struct nf_conn *ct)
358 {
359 	struct nf_conn_labels *cl;
360 
361 	cl = nf_ct_labels_find(ct);
362 	if (!cl) {
363 		nf_ct_labels_ext_add(ct);
364 		cl = nf_ct_labels_find(ct);
365 	}
366 
367 	return cl;
368 }
369 
370 /* Initialize labels for a new, yet to be committed conntrack entry.  Note that
371  * since the new connection is not yet confirmed, and thus no-one else has
372  * access to it's labels, we simply write them over.
373  */
374 static int ovs_ct_init_labels(struct nf_conn *ct, struct sw_flow_key *key,
375 			      const struct ovs_key_ct_labels *labels,
376 			      const struct ovs_key_ct_labels *mask)
377 {
378 	struct nf_conn_labels *cl, *master_cl;
379 	bool have_mask = labels_nonzero(mask);
380 
381 	/* Inherit master's labels to the related connection? */
382 	master_cl = ct->master ? nf_ct_labels_find(ct->master) : NULL;
383 
384 	if (!master_cl && !have_mask)
385 		return 0;   /* Nothing to do. */
386 
387 	cl = ovs_ct_get_conn_labels(ct);
388 	if (!cl)
389 		return -ENOSPC;
390 
391 	/* Inherit the master's labels, if any. */
392 	if (master_cl)
393 		*cl = *master_cl;
394 
395 	if (have_mask) {
396 		u32 *dst = (u32 *)cl->bits;
397 		int i;
398 
399 		for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
400 			dst[i] = (dst[i] & ~mask->ct_labels_32[i]) |
401 				(labels->ct_labels_32[i]
402 				 & mask->ct_labels_32[i]);
403 	}
404 
405 	/* Labels are included in the IPCTNL_MSG_CT_NEW event only if the
406 	 * IPCT_LABEL bit is set in the event cache.
407 	 */
408 	nf_conntrack_event_cache(IPCT_LABEL, ct);
409 
410 	memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
411 
412 	return 0;
413 }
414 
415 static int ovs_ct_set_labels(struct nf_conn *ct, struct sw_flow_key *key,
416 			     const struct ovs_key_ct_labels *labels,
417 			     const struct ovs_key_ct_labels *mask)
418 {
419 	struct nf_conn_labels *cl;
420 	int err;
421 
422 	cl = ovs_ct_get_conn_labels(ct);
423 	if (!cl)
424 		return -ENOSPC;
425 
426 	err = nf_connlabels_replace(ct, labels->ct_labels_32,
427 				    mask->ct_labels_32,
428 				    OVS_CT_LABELS_LEN_32);
429 	if (err)
430 		return err;
431 
432 	memcpy(&key->ct.labels, cl->bits, OVS_CT_LABELS_LEN);
433 
434 	return 0;
435 }
436 
437 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
438  * value if 'skb' is freed.
439  */
440 static int handle_fragments(struct net *net, struct sw_flow_key *key,
441 			    u16 zone, struct sk_buff *skb)
442 {
443 	struct ovs_skb_cb ovs_cb = *OVS_CB(skb);
444 	int err;
445 
446 	if (key->eth.type == htons(ETH_P_IP)) {
447 		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
448 
449 		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
450 		err = ip_defrag(net, skb, user);
451 		if (err)
452 			return err;
453 
454 		ovs_cb.mru = IPCB(skb)->frag_max_size;
455 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
456 	} else if (key->eth.type == htons(ETH_P_IPV6)) {
457 		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
458 
459 		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
460 		err = nf_ct_frag6_gather(net, skb, user);
461 		if (err) {
462 			if (err != -EINPROGRESS)
463 				kfree_skb(skb);
464 			return err;
465 		}
466 
467 		key->ip.proto = ipv6_hdr(skb)->nexthdr;
468 		ovs_cb.mru = IP6CB(skb)->frag_max_size;
469 #endif
470 	} else {
471 		kfree_skb(skb);
472 		return -EPFNOSUPPORT;
473 	}
474 
475 	/* The key extracted from the fragment that completed this datagram
476 	 * likely didn't have an L4 header, so regenerate it.
477 	 */
478 	ovs_flow_key_update_l3l4(skb, key);
479 
480 	key->ip.frag = OVS_FRAG_TYPE_NONE;
481 	skb_clear_hash(skb);
482 	skb->ignore_df = 1;
483 	*OVS_CB(skb) = ovs_cb;
484 
485 	return 0;
486 }
487 
488 static struct nf_conntrack_expect *
489 ovs_ct_expect_find(struct net *net, const struct nf_conntrack_zone *zone,
490 		   u16 proto, const struct sk_buff *skb)
491 {
492 	struct nf_conntrack_tuple tuple;
493 	struct nf_conntrack_expect *exp;
494 
495 	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), proto, net, &tuple))
496 		return NULL;
497 
498 	exp = __nf_ct_expect_find(net, zone, &tuple);
499 	if (exp) {
500 		struct nf_conntrack_tuple_hash *h;
501 
502 		/* Delete existing conntrack entry, if it clashes with the
503 		 * expectation.  This can happen since conntrack ALGs do not
504 		 * check for clashes between (new) expectations and existing
505 		 * conntrack entries.  nf_conntrack_in() will check the
506 		 * expectations only if a conntrack entry can not be found,
507 		 * which can lead to OVS finding the expectation (here) in the
508 		 * init direction, but which will not be removed by the
509 		 * nf_conntrack_in() call, if a matching conntrack entry is
510 		 * found instead.  In this case all init direction packets
511 		 * would be reported as new related packets, while reply
512 		 * direction packets would be reported as un-related
513 		 * established packets.
514 		 */
515 		h = nf_conntrack_find_get(net, zone, &tuple);
516 		if (h) {
517 			struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
518 
519 			nf_ct_delete(ct, 0, 0);
520 			nf_ct_put(ct);
521 		}
522 	}
523 
524 	return exp;
525 }
526 
527 /* This replicates logic from nf_conntrack_core.c that is not exported. */
528 static enum ip_conntrack_info
529 ovs_ct_get_info(const struct nf_conntrack_tuple_hash *h)
530 {
531 	const struct nf_conn *ct = nf_ct_tuplehash_to_ctrack(h);
532 
533 	if (NF_CT_DIRECTION(h) == IP_CT_DIR_REPLY)
534 		return IP_CT_ESTABLISHED_REPLY;
535 	/* Once we've had two way comms, always ESTABLISHED. */
536 	if (test_bit(IPS_SEEN_REPLY_BIT, &ct->status))
537 		return IP_CT_ESTABLISHED;
538 	if (test_bit(IPS_EXPECTED_BIT, &ct->status))
539 		return IP_CT_RELATED;
540 	return IP_CT_NEW;
541 }
542 
543 /* Find an existing connection which this packet belongs to without
544  * re-attributing statistics or modifying the connection state.  This allows an
545  * skb->_nfct lost due to an upcall to be recovered during actions execution.
546  *
547  * Must be called with rcu_read_lock.
548  *
549  * On success, populates skb->_nfct and returns the connection.  Returns NULL
550  * if there is no existing entry.
551  */
552 static struct nf_conn *
553 ovs_ct_find_existing(struct net *net, const struct nf_conntrack_zone *zone,
554 		     u8 l3num, struct sk_buff *skb, bool natted)
555 {
556 	struct nf_conntrack_tuple tuple;
557 	struct nf_conntrack_tuple_hash *h;
558 	struct nf_conn *ct;
559 
560 	if (!nf_ct_get_tuplepr(skb, skb_network_offset(skb), l3num,
561 			       net, &tuple)) {
562 		pr_debug("ovs_ct_find_existing: Can't get tuple\n");
563 		return NULL;
564 	}
565 
566 	/* Must invert the tuple if skb has been transformed by NAT. */
567 	if (natted) {
568 		struct nf_conntrack_tuple inverse;
569 
570 		if (!nf_ct_invert_tuple(&inverse, &tuple)) {
571 			pr_debug("ovs_ct_find_existing: Inversion failed!\n");
572 			return NULL;
573 		}
574 		tuple = inverse;
575 	}
576 
577 	/* look for tuple match */
578 	h = nf_conntrack_find_get(net, zone, &tuple);
579 	if (!h)
580 		return NULL;   /* Not found. */
581 
582 	ct = nf_ct_tuplehash_to_ctrack(h);
583 
584 	/* Inverted packet tuple matches the reverse direction conntrack tuple,
585 	 * select the other tuplehash to get the right 'ctinfo' bits for this
586 	 * packet.
587 	 */
588 	if (natted)
589 		h = &ct->tuplehash[!h->tuple.dst.dir];
590 
591 	nf_ct_set(skb, ct, ovs_ct_get_info(h));
592 	return ct;
593 }
594 
595 static
596 struct nf_conn *ovs_ct_executed(struct net *net,
597 				const struct sw_flow_key *key,
598 				const struct ovs_conntrack_info *info,
599 				struct sk_buff *skb,
600 				bool *ct_executed)
601 {
602 	struct nf_conn *ct = NULL;
603 
604 	/* If no ct, check if we have evidence that an existing conntrack entry
605 	 * might be found for this skb.  This happens when we lose a skb->_nfct
606 	 * due to an upcall, or if the direction is being forced.  If the
607 	 * connection was not confirmed, it is not cached and needs to be run
608 	 * through conntrack again.
609 	 */
610 	*ct_executed = (key->ct_state & OVS_CS_F_TRACKED) &&
611 		       !(key->ct_state & OVS_CS_F_INVALID) &&
612 		       (key->ct_zone == info->zone.id);
613 
614 	if (*ct_executed || (!key->ct_state && info->force)) {
615 		ct = ovs_ct_find_existing(net, &info->zone, info->family, skb,
616 					  !!(key->ct_state &
617 					  OVS_CS_F_NAT_MASK));
618 	}
619 
620 	return ct;
621 }
622 
623 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
624 static bool skb_nfct_cached(struct net *net,
625 			    const struct sw_flow_key *key,
626 			    const struct ovs_conntrack_info *info,
627 			    struct sk_buff *skb)
628 {
629 	enum ip_conntrack_info ctinfo;
630 	struct nf_conn *ct;
631 	bool ct_executed = true;
632 
633 	ct = nf_ct_get(skb, &ctinfo);
634 	if (!ct)
635 		ct = ovs_ct_executed(net, key, info, skb, &ct_executed);
636 
637 	if (ct)
638 		nf_ct_get(skb, &ctinfo);
639 	else
640 		return false;
641 
642 	if (!net_eq(net, read_pnet(&ct->ct_net)))
643 		return false;
644 	if (!nf_ct_zone_equal_any(info->ct, nf_ct_zone(ct)))
645 		return false;
646 	if (info->helper) {
647 		struct nf_conn_help *help;
648 
649 		help = nf_ct_ext_find(ct, NF_CT_EXT_HELPER);
650 		if (help && rcu_access_pointer(help->helper) != info->helper)
651 			return false;
652 	}
653 	if (info->nf_ct_timeout) {
654 		struct nf_conn_timeout *timeout_ext;
655 
656 		timeout_ext = nf_ct_timeout_find(ct);
657 		if (!timeout_ext || info->nf_ct_timeout !=
658 		    rcu_dereference(timeout_ext->timeout))
659 			return false;
660 	}
661 	/* Force conntrack entry direction to the current packet? */
662 	if (info->force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
663 		/* Delete the conntrack entry if confirmed, else just release
664 		 * the reference.
665 		 */
666 		if (nf_ct_is_confirmed(ct))
667 			nf_ct_delete(ct, 0, 0);
668 
669 		nf_ct_put(ct);
670 		nf_ct_set(skb, NULL, 0);
671 		return false;
672 	}
673 
674 	return ct_executed;
675 }
676 
677 #if IS_ENABLED(CONFIG_NF_NAT)
678 static void ovs_nat_update_key(struct sw_flow_key *key,
679 			       const struct sk_buff *skb,
680 			       enum nf_nat_manip_type maniptype)
681 {
682 	if (maniptype == NF_NAT_MANIP_SRC) {
683 		__be16 src;
684 
685 		key->ct_state |= OVS_CS_F_SRC_NAT;
686 		if (key->eth.type == htons(ETH_P_IP))
687 			key->ipv4.addr.src = ip_hdr(skb)->saddr;
688 		else if (key->eth.type == htons(ETH_P_IPV6))
689 			memcpy(&key->ipv6.addr.src, &ipv6_hdr(skb)->saddr,
690 			       sizeof(key->ipv6.addr.src));
691 		else
692 			return;
693 
694 		if (key->ip.proto == IPPROTO_UDP)
695 			src = udp_hdr(skb)->source;
696 		else if (key->ip.proto == IPPROTO_TCP)
697 			src = tcp_hdr(skb)->source;
698 		else if (key->ip.proto == IPPROTO_SCTP)
699 			src = sctp_hdr(skb)->source;
700 		else
701 			return;
702 
703 		key->tp.src = src;
704 	} else {
705 		__be16 dst;
706 
707 		key->ct_state |= OVS_CS_F_DST_NAT;
708 		if (key->eth.type == htons(ETH_P_IP))
709 			key->ipv4.addr.dst = ip_hdr(skb)->daddr;
710 		else if (key->eth.type == htons(ETH_P_IPV6))
711 			memcpy(&key->ipv6.addr.dst, &ipv6_hdr(skb)->daddr,
712 			       sizeof(key->ipv6.addr.dst));
713 		else
714 			return;
715 
716 		if (key->ip.proto == IPPROTO_UDP)
717 			dst = udp_hdr(skb)->dest;
718 		else if (key->ip.proto == IPPROTO_TCP)
719 			dst = tcp_hdr(skb)->dest;
720 		else if (key->ip.proto == IPPROTO_SCTP)
721 			dst = sctp_hdr(skb)->dest;
722 		else
723 			return;
724 
725 		key->tp.dst = dst;
726 	}
727 }
728 
729 /* Returns NF_DROP if the packet should be dropped, NF_ACCEPT otherwise. */
730 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
731 		      const struct ovs_conntrack_info *info,
732 		      struct sk_buff *skb, struct nf_conn *ct,
733 		      enum ip_conntrack_info ctinfo)
734 {
735 	int err, action = 0;
736 
737 	if (!(info->nat & OVS_CT_NAT))
738 		return NF_ACCEPT;
739 	if (info->nat & OVS_CT_SRC_NAT)
740 		action |= BIT(NF_NAT_MANIP_SRC);
741 	if (info->nat & OVS_CT_DST_NAT)
742 		action |= BIT(NF_NAT_MANIP_DST);
743 
744 	err = nf_ct_nat(skb, ct, ctinfo, &action, &info->range, info->commit);
745 
746 	if (action & BIT(NF_NAT_MANIP_SRC))
747 		ovs_nat_update_key(key, skb, NF_NAT_MANIP_SRC);
748 	if (action & BIT(NF_NAT_MANIP_DST))
749 		ovs_nat_update_key(key, skb, NF_NAT_MANIP_DST);
750 
751 	return err;
752 }
753 #else /* !CONFIG_NF_NAT */
754 static int ovs_ct_nat(struct net *net, struct sw_flow_key *key,
755 		      const struct ovs_conntrack_info *info,
756 		      struct sk_buff *skb, struct nf_conn *ct,
757 		      enum ip_conntrack_info ctinfo)
758 {
759 	return NF_ACCEPT;
760 }
761 #endif
762 
763 /* Pass 'skb' through conntrack in 'net', using zone configured in 'info', if
764  * not done already.  Update key with new CT state after passing the packet
765  * through conntrack.
766  * Note that if the packet is deemed invalid by conntrack, skb->_nfct will be
767  * set to NULL and 0 will be returned.
768  */
769 static int __ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
770 			   const struct ovs_conntrack_info *info,
771 			   struct sk_buff *skb)
772 {
773 	/* If we are recirculating packets to match on conntrack fields and
774 	 * committing with a separate conntrack action,  then we don't need to
775 	 * actually run the packet through conntrack twice unless it's for a
776 	 * different zone.
777 	 */
778 	bool cached = skb_nfct_cached(net, key, info, skb);
779 	enum ip_conntrack_info ctinfo;
780 	struct nf_conn *ct;
781 
782 	if (!cached) {
783 		struct nf_hook_state state = {
784 			.hook = NF_INET_PRE_ROUTING,
785 			.pf = info->family,
786 			.net = net,
787 		};
788 		struct nf_conn *tmpl = info->ct;
789 		int err;
790 
791 		/* Associate skb with specified zone. */
792 		if (tmpl) {
793 			ct = nf_ct_get(skb, &ctinfo);
794 			nf_ct_put(ct);
795 			nf_conntrack_get(&tmpl->ct_general);
796 			nf_ct_set(skb, tmpl, IP_CT_NEW);
797 		}
798 
799 		err = nf_conntrack_in(skb, &state);
800 		if (err != NF_ACCEPT)
801 			return -ENOENT;
802 
803 		/* Clear CT state NAT flags to mark that we have not yet done
804 		 * NAT after the nf_conntrack_in() call.  We can actually clear
805 		 * the whole state, as it will be re-initialized below.
806 		 */
807 		key->ct_state = 0;
808 
809 		/* Update the key, but keep the NAT flags. */
810 		ovs_ct_update_key(skb, info, key, true, true);
811 	}
812 
813 	ct = nf_ct_get(skb, &ctinfo);
814 	if (ct) {
815 		bool add_helper = false;
816 
817 		/* Packets starting a new connection must be NATted before the
818 		 * helper, so that the helper knows about the NAT.  We enforce
819 		 * this by delaying both NAT and helper calls for unconfirmed
820 		 * connections until the committing CT action.  For later
821 		 * packets NAT and Helper may be called in either order.
822 		 *
823 		 * NAT will be done only if the CT action has NAT, and only
824 		 * once per packet (per zone), as guarded by the NAT bits in
825 		 * the key->ct_state.
826 		 */
827 		if (info->nat && !(key->ct_state & OVS_CS_F_NAT_MASK) &&
828 		    (nf_ct_is_confirmed(ct) || info->commit) &&
829 		    ovs_ct_nat(net, key, info, skb, ct, ctinfo) != NF_ACCEPT) {
830 			return -EINVAL;
831 		}
832 
833 		/* Userspace may decide to perform a ct lookup without a helper
834 		 * specified followed by a (recirculate and) commit with one,
835 		 * or attach a helper in a later commit.  Therefore, for
836 		 * connections which we will commit, we may need to attach
837 		 * the helper here.
838 		 */
839 		if (!nf_ct_is_confirmed(ct) && info->commit &&
840 		    info->helper && !nfct_help(ct)) {
841 			int err = __nf_ct_try_assign_helper(ct, info->ct,
842 							    GFP_ATOMIC);
843 			if (err)
844 				return err;
845 			add_helper = true;
846 
847 			/* helper installed, add seqadj if NAT is required */
848 			if (info->nat && !nfct_seqadj(ct)) {
849 				if (!nfct_seqadj_ext_add(ct))
850 					return -EINVAL;
851 			}
852 		}
853 
854 		/* Call the helper only if:
855 		 * - nf_conntrack_in() was executed above ("!cached") or a
856 		 *   helper was just attached ("add_helper") for a confirmed
857 		 *   connection, or
858 		 * - When committing an unconfirmed connection.
859 		 */
860 		if ((nf_ct_is_confirmed(ct) ? !cached || add_helper :
861 					      info->commit) &&
862 		    nf_ct_helper(skb, ct, ctinfo, info->family) != NF_ACCEPT) {
863 			return -EINVAL;
864 		}
865 
866 		if (nf_ct_protonum(ct) == IPPROTO_TCP &&
867 		    nf_ct_is_confirmed(ct) && nf_conntrack_tcp_established(ct)) {
868 			/* Be liberal for tcp packets so that out-of-window
869 			 * packets are not marked invalid.
870 			 */
871 			nf_ct_set_tcp_be_liberal(ct);
872 		}
873 
874 		nf_conn_act_ct_ext_fill(skb, ct, ctinfo);
875 	}
876 
877 	return 0;
878 }
879 
880 /* Lookup connection and read fields into key. */
881 static int ovs_ct_lookup(struct net *net, struct sw_flow_key *key,
882 			 const struct ovs_conntrack_info *info,
883 			 struct sk_buff *skb)
884 {
885 	struct nf_conntrack_expect *exp;
886 
887 	/* If we pass an expected packet through nf_conntrack_in() the
888 	 * expectation is typically removed, but the packet could still be
889 	 * lost in upcall processing.  To prevent this from happening we
890 	 * perform an explicit expectation lookup.  Expected connections are
891 	 * always new, and will be passed through conntrack only when they are
892 	 * committed, as it is OK to remove the expectation at that time.
893 	 */
894 	exp = ovs_ct_expect_find(net, &info->zone, info->family, skb);
895 	if (exp) {
896 		u8 state;
897 
898 		/* NOTE: New connections are NATted and Helped only when
899 		 * committed, so we are not calling into NAT here.
900 		 */
901 		state = OVS_CS_F_TRACKED | OVS_CS_F_NEW | OVS_CS_F_RELATED;
902 		__ovs_ct_update_key(key, state, &info->zone, exp->master);
903 	} else {
904 		struct nf_conn *ct;
905 		int err;
906 
907 		err = __ovs_ct_lookup(net, key, info, skb);
908 		if (err)
909 			return err;
910 
911 		ct = (struct nf_conn *)skb_nfct(skb);
912 		if (ct)
913 			nf_ct_deliver_cached_events(ct);
914 	}
915 
916 	return 0;
917 }
918 
919 static bool labels_nonzero(const struct ovs_key_ct_labels *labels)
920 {
921 	size_t i;
922 
923 	for (i = 0; i < OVS_CT_LABELS_LEN_32; i++)
924 		if (labels->ct_labels_32[i])
925 			return true;
926 
927 	return false;
928 }
929 
930 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
931 static struct hlist_head *ct_limit_hash_bucket(
932 	const struct ovs_ct_limit_info *info, u16 zone)
933 {
934 	return &info->limits[zone & (CT_LIMIT_HASH_BUCKETS - 1)];
935 }
936 
937 /* Call with ovs_mutex */
938 static void ct_limit_set(const struct ovs_ct_limit_info *info,
939 			 struct ovs_ct_limit *new_ct_limit)
940 {
941 	struct ovs_ct_limit *ct_limit;
942 	struct hlist_head *head;
943 
944 	head = ct_limit_hash_bucket(info, new_ct_limit->zone);
945 	hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
946 		if (ct_limit->zone == new_ct_limit->zone) {
947 			hlist_replace_rcu(&ct_limit->hlist_node,
948 					  &new_ct_limit->hlist_node);
949 			kfree_rcu(ct_limit, rcu);
950 			return;
951 		}
952 	}
953 
954 	hlist_add_head_rcu(&new_ct_limit->hlist_node, head);
955 }
956 
957 /* Call with ovs_mutex */
958 static void ct_limit_del(const struct ovs_ct_limit_info *info, u16 zone)
959 {
960 	struct ovs_ct_limit *ct_limit;
961 	struct hlist_head *head;
962 	struct hlist_node *n;
963 
964 	head = ct_limit_hash_bucket(info, zone);
965 	hlist_for_each_entry_safe(ct_limit, n, head, hlist_node) {
966 		if (ct_limit->zone == zone) {
967 			hlist_del_rcu(&ct_limit->hlist_node);
968 			kfree_rcu(ct_limit, rcu);
969 			return;
970 		}
971 	}
972 }
973 
974 /* Call with RCU read lock */
975 static u32 ct_limit_get(const struct ovs_ct_limit_info *info, u16 zone)
976 {
977 	struct ovs_ct_limit *ct_limit;
978 	struct hlist_head *head;
979 
980 	head = ct_limit_hash_bucket(info, zone);
981 	hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
982 		if (ct_limit->zone == zone)
983 			return ct_limit->limit;
984 	}
985 
986 	return info->default_limit;
987 }
988 
989 static int ovs_ct_check_limit(struct net *net,
990 			      const struct ovs_conntrack_info *info,
991 			      const struct nf_conntrack_tuple *tuple)
992 {
993 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
994 	const struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
995 	u32 per_zone_limit, connections;
996 	u32 conncount_key;
997 
998 	conncount_key = info->zone.id;
999 
1000 	per_zone_limit = ct_limit_get(ct_limit_info, info->zone.id);
1001 	if (per_zone_limit == OVS_CT_LIMIT_UNLIMITED)
1002 		return 0;
1003 
1004 	connections = nf_conncount_count(net, ct_limit_info->data,
1005 					 &conncount_key, tuple, &info->zone);
1006 	if (connections > per_zone_limit)
1007 		return -ENOMEM;
1008 
1009 	return 0;
1010 }
1011 #endif
1012 
1013 /* Lookup connection and confirm if unconfirmed. */
1014 static int ovs_ct_commit(struct net *net, struct sw_flow_key *key,
1015 			 const struct ovs_conntrack_info *info,
1016 			 struct sk_buff *skb)
1017 {
1018 	enum ip_conntrack_info ctinfo;
1019 	struct nf_conn *ct;
1020 	int err;
1021 
1022 	err = __ovs_ct_lookup(net, key, info, skb);
1023 	if (err)
1024 		return err;
1025 
1026 	/* The connection could be invalid, in which case this is a no-op.*/
1027 	ct = nf_ct_get(skb, &ctinfo);
1028 	if (!ct)
1029 		return 0;
1030 
1031 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1032 	if (static_branch_unlikely(&ovs_ct_limit_enabled)) {
1033 		if (!nf_ct_is_confirmed(ct)) {
1034 			err = ovs_ct_check_limit(net, info,
1035 				&ct->tuplehash[IP_CT_DIR_ORIGINAL].tuple);
1036 			if (err) {
1037 				net_warn_ratelimited("openvswitch: zone: %u "
1038 					"exceeds conntrack limit\n",
1039 					info->zone.id);
1040 				return err;
1041 			}
1042 		}
1043 	}
1044 #endif
1045 
1046 	/* Set the conntrack event mask if given.  NEW and DELETE events have
1047 	 * their own groups, but the NFNLGRP_CONNTRACK_UPDATE group listener
1048 	 * typically would receive many kinds of updates.  Setting the event
1049 	 * mask allows those events to be filtered.  The set event mask will
1050 	 * remain in effect for the lifetime of the connection unless changed
1051 	 * by a further CT action with both the commit flag and the eventmask
1052 	 * option. */
1053 	if (info->have_eventmask) {
1054 		struct nf_conntrack_ecache *cache = nf_ct_ecache_find(ct);
1055 
1056 		if (cache)
1057 			cache->ctmask = info->eventmask;
1058 	}
1059 
1060 	/* Apply changes before confirming the connection so that the initial
1061 	 * conntrack NEW netlink event carries the values given in the CT
1062 	 * action.
1063 	 */
1064 	if (info->mark.mask) {
1065 		err = ovs_ct_set_mark(ct, key, info->mark.value,
1066 				      info->mark.mask);
1067 		if (err)
1068 			return err;
1069 	}
1070 	if (!nf_ct_is_confirmed(ct)) {
1071 		err = ovs_ct_init_labels(ct, key, &info->labels.value,
1072 					 &info->labels.mask);
1073 		if (err)
1074 			return err;
1075 
1076 		nf_conn_act_ct_ext_add(ct);
1077 	} else if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1078 		   labels_nonzero(&info->labels.mask)) {
1079 		err = ovs_ct_set_labels(ct, key, &info->labels.value,
1080 					&info->labels.mask);
1081 		if (err)
1082 			return err;
1083 	}
1084 	/* This will take care of sending queued events even if the connection
1085 	 * is already confirmed.
1086 	 */
1087 	if (nf_conntrack_confirm(skb) != NF_ACCEPT)
1088 		return -EINVAL;
1089 
1090 	return 0;
1091 }
1092 
1093 /* Trim the skb to the length specified by the IP/IPv6 header,
1094  * removing any trailing lower-layer padding. This prepares the skb
1095  * for higher-layer processing that assumes skb->len excludes padding
1096  * (such as nf_ip_checksum). The caller needs to pull the skb to the
1097  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
1098  */
1099 static int ovs_skb_network_trim(struct sk_buff *skb)
1100 {
1101 	unsigned int len;
1102 	int err;
1103 
1104 	switch (skb->protocol) {
1105 	case htons(ETH_P_IP):
1106 		len = ntohs(ip_hdr(skb)->tot_len);
1107 		break;
1108 	case htons(ETH_P_IPV6):
1109 		len = sizeof(struct ipv6hdr)
1110 			+ ntohs(ipv6_hdr(skb)->payload_len);
1111 		break;
1112 	default:
1113 		len = skb->len;
1114 	}
1115 
1116 	err = pskb_trim_rcsum(skb, len);
1117 	if (err)
1118 		kfree_skb(skb);
1119 
1120 	return err;
1121 }
1122 
1123 /* Returns 0 on success, -EINPROGRESS if 'skb' is stolen, or other nonzero
1124  * value if 'skb' is freed.
1125  */
1126 int ovs_ct_execute(struct net *net, struct sk_buff *skb,
1127 		   struct sw_flow_key *key,
1128 		   const struct ovs_conntrack_info *info)
1129 {
1130 	int nh_ofs;
1131 	int err;
1132 
1133 	/* The conntrack module expects to be working at L3. */
1134 	nh_ofs = skb_network_offset(skb);
1135 	skb_pull_rcsum(skb, nh_ofs);
1136 
1137 	err = ovs_skb_network_trim(skb);
1138 	if (err)
1139 		return err;
1140 
1141 	if (key->ip.frag != OVS_FRAG_TYPE_NONE) {
1142 		err = handle_fragments(net, key, info->zone.id, skb);
1143 		if (err)
1144 			return err;
1145 	}
1146 
1147 	if (info->commit)
1148 		err = ovs_ct_commit(net, key, info, skb);
1149 	else
1150 		err = ovs_ct_lookup(net, key, info, skb);
1151 
1152 	skb_push_rcsum(skb, nh_ofs);
1153 	if (err)
1154 		kfree_skb(skb);
1155 	return err;
1156 }
1157 
1158 int ovs_ct_clear(struct sk_buff *skb, struct sw_flow_key *key)
1159 {
1160 	enum ip_conntrack_info ctinfo;
1161 	struct nf_conn *ct;
1162 
1163 	ct = nf_ct_get(skb, &ctinfo);
1164 
1165 	nf_ct_put(ct);
1166 	nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
1167 
1168 	if (key)
1169 		ovs_ct_fill_key(skb, key, false);
1170 
1171 	return 0;
1172 }
1173 
1174 #if IS_ENABLED(CONFIG_NF_NAT)
1175 static int parse_nat(const struct nlattr *attr,
1176 		     struct ovs_conntrack_info *info, bool log)
1177 {
1178 	struct nlattr *a;
1179 	int rem;
1180 	bool have_ip_max = false;
1181 	bool have_proto_max = false;
1182 	bool ip_vers = (info->family == NFPROTO_IPV6);
1183 
1184 	nla_for_each_nested(a, attr, rem) {
1185 		static const int ovs_nat_attr_lens[OVS_NAT_ATTR_MAX + 1][2] = {
1186 			[OVS_NAT_ATTR_SRC] = {0, 0},
1187 			[OVS_NAT_ATTR_DST] = {0, 0},
1188 			[OVS_NAT_ATTR_IP_MIN] = {sizeof(struct in_addr),
1189 						 sizeof(struct in6_addr)},
1190 			[OVS_NAT_ATTR_IP_MAX] = {sizeof(struct in_addr),
1191 						 sizeof(struct in6_addr)},
1192 			[OVS_NAT_ATTR_PROTO_MIN] = {sizeof(u16), sizeof(u16)},
1193 			[OVS_NAT_ATTR_PROTO_MAX] = {sizeof(u16), sizeof(u16)},
1194 			[OVS_NAT_ATTR_PERSISTENT] = {0, 0},
1195 			[OVS_NAT_ATTR_PROTO_HASH] = {0, 0},
1196 			[OVS_NAT_ATTR_PROTO_RANDOM] = {0, 0},
1197 		};
1198 		int type = nla_type(a);
1199 
1200 		if (type > OVS_NAT_ATTR_MAX) {
1201 			OVS_NLERR(log, "Unknown NAT attribute (type=%d, max=%d)",
1202 				  type, OVS_NAT_ATTR_MAX);
1203 			return -EINVAL;
1204 		}
1205 
1206 		if (nla_len(a) != ovs_nat_attr_lens[type][ip_vers]) {
1207 			OVS_NLERR(log, "NAT attribute type %d has unexpected length (%d != %d)",
1208 				  type, nla_len(a),
1209 				  ovs_nat_attr_lens[type][ip_vers]);
1210 			return -EINVAL;
1211 		}
1212 
1213 		switch (type) {
1214 		case OVS_NAT_ATTR_SRC:
1215 		case OVS_NAT_ATTR_DST:
1216 			if (info->nat) {
1217 				OVS_NLERR(log, "Only one type of NAT may be specified");
1218 				return -ERANGE;
1219 			}
1220 			info->nat |= OVS_CT_NAT;
1221 			info->nat |= ((type == OVS_NAT_ATTR_SRC)
1222 					? OVS_CT_SRC_NAT : OVS_CT_DST_NAT);
1223 			break;
1224 
1225 		case OVS_NAT_ATTR_IP_MIN:
1226 			nla_memcpy(&info->range.min_addr, a,
1227 				   sizeof(info->range.min_addr));
1228 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1229 			break;
1230 
1231 		case OVS_NAT_ATTR_IP_MAX:
1232 			have_ip_max = true;
1233 			nla_memcpy(&info->range.max_addr, a,
1234 				   sizeof(info->range.max_addr));
1235 			info->range.flags |= NF_NAT_RANGE_MAP_IPS;
1236 			break;
1237 
1238 		case OVS_NAT_ATTR_PROTO_MIN:
1239 			info->range.min_proto.all = htons(nla_get_u16(a));
1240 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1241 			break;
1242 
1243 		case OVS_NAT_ATTR_PROTO_MAX:
1244 			have_proto_max = true;
1245 			info->range.max_proto.all = htons(nla_get_u16(a));
1246 			info->range.flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1247 			break;
1248 
1249 		case OVS_NAT_ATTR_PERSISTENT:
1250 			info->range.flags |= NF_NAT_RANGE_PERSISTENT;
1251 			break;
1252 
1253 		case OVS_NAT_ATTR_PROTO_HASH:
1254 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM;
1255 			break;
1256 
1257 		case OVS_NAT_ATTR_PROTO_RANDOM:
1258 			info->range.flags |= NF_NAT_RANGE_PROTO_RANDOM_FULLY;
1259 			break;
1260 
1261 		default:
1262 			OVS_NLERR(log, "Unknown nat attribute (%d)", type);
1263 			return -EINVAL;
1264 		}
1265 	}
1266 
1267 	if (rem > 0) {
1268 		OVS_NLERR(log, "NAT attribute has %d unknown bytes", rem);
1269 		return -EINVAL;
1270 	}
1271 	if (!info->nat) {
1272 		/* Do not allow flags if no type is given. */
1273 		if (info->range.flags) {
1274 			OVS_NLERR(log,
1275 				  "NAT flags may be given only when NAT range (SRC or DST) is also specified."
1276 				  );
1277 			return -EINVAL;
1278 		}
1279 		info->nat = OVS_CT_NAT;   /* NAT existing connections. */
1280 	} else if (!info->commit) {
1281 		OVS_NLERR(log,
1282 			  "NAT attributes may be specified only when CT COMMIT flag is also specified."
1283 			  );
1284 		return -EINVAL;
1285 	}
1286 	/* Allow missing IP_MAX. */
1287 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS && !have_ip_max) {
1288 		memcpy(&info->range.max_addr, &info->range.min_addr,
1289 		       sizeof(info->range.max_addr));
1290 	}
1291 	/* Allow missing PROTO_MAX. */
1292 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1293 	    !have_proto_max) {
1294 		info->range.max_proto.all = info->range.min_proto.all;
1295 	}
1296 	return 0;
1297 }
1298 #endif
1299 
1300 static const struct ovs_ct_len_tbl ovs_ct_attr_lens[OVS_CT_ATTR_MAX + 1] = {
1301 	[OVS_CT_ATTR_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1302 	[OVS_CT_ATTR_FORCE_COMMIT]	= { .minlen = 0, .maxlen = 0 },
1303 	[OVS_CT_ATTR_ZONE]	= { .minlen = sizeof(u16),
1304 				    .maxlen = sizeof(u16) },
1305 	[OVS_CT_ATTR_MARK]	= { .minlen = sizeof(struct md_mark),
1306 				    .maxlen = sizeof(struct md_mark) },
1307 	[OVS_CT_ATTR_LABELS]	= { .minlen = sizeof(struct md_labels),
1308 				    .maxlen = sizeof(struct md_labels) },
1309 	[OVS_CT_ATTR_HELPER]	= { .minlen = 1,
1310 				    .maxlen = NF_CT_HELPER_NAME_LEN },
1311 #if IS_ENABLED(CONFIG_NF_NAT)
1312 	/* NAT length is checked when parsing the nested attributes. */
1313 	[OVS_CT_ATTR_NAT]	= { .minlen = 0, .maxlen = INT_MAX },
1314 #endif
1315 	[OVS_CT_ATTR_EVENTMASK]	= { .minlen = sizeof(u32),
1316 				    .maxlen = sizeof(u32) },
1317 	[OVS_CT_ATTR_TIMEOUT] = { .minlen = 1,
1318 				  .maxlen = CTNL_TIMEOUT_NAME_MAX },
1319 };
1320 
1321 static int parse_ct(const struct nlattr *attr, struct ovs_conntrack_info *info,
1322 		    const char **helper, bool log)
1323 {
1324 	struct nlattr *a;
1325 	int rem;
1326 
1327 	nla_for_each_nested(a, attr, rem) {
1328 		int type = nla_type(a);
1329 		int maxlen;
1330 		int minlen;
1331 
1332 		if (type > OVS_CT_ATTR_MAX) {
1333 			OVS_NLERR(log,
1334 				  "Unknown conntrack attr (type=%d, max=%d)",
1335 				  type, OVS_CT_ATTR_MAX);
1336 			return -EINVAL;
1337 		}
1338 
1339 		maxlen = ovs_ct_attr_lens[type].maxlen;
1340 		minlen = ovs_ct_attr_lens[type].minlen;
1341 		if (nla_len(a) < minlen || nla_len(a) > maxlen) {
1342 			OVS_NLERR(log,
1343 				  "Conntrack attr type has unexpected length (type=%d, length=%d, expected=%d)",
1344 				  type, nla_len(a), maxlen);
1345 			return -EINVAL;
1346 		}
1347 
1348 		switch (type) {
1349 		case OVS_CT_ATTR_FORCE_COMMIT:
1350 			info->force = true;
1351 			fallthrough;
1352 		case OVS_CT_ATTR_COMMIT:
1353 			info->commit = true;
1354 			break;
1355 #ifdef CONFIG_NF_CONNTRACK_ZONES
1356 		case OVS_CT_ATTR_ZONE:
1357 			info->zone.id = nla_get_u16(a);
1358 			break;
1359 #endif
1360 #ifdef CONFIG_NF_CONNTRACK_MARK
1361 		case OVS_CT_ATTR_MARK: {
1362 			struct md_mark *mark = nla_data(a);
1363 
1364 			if (!mark->mask) {
1365 				OVS_NLERR(log, "ct_mark mask cannot be 0");
1366 				return -EINVAL;
1367 			}
1368 			info->mark = *mark;
1369 			break;
1370 		}
1371 #endif
1372 #ifdef CONFIG_NF_CONNTRACK_LABELS
1373 		case OVS_CT_ATTR_LABELS: {
1374 			struct md_labels *labels = nla_data(a);
1375 
1376 			if (!labels_nonzero(&labels->mask)) {
1377 				OVS_NLERR(log, "ct_labels mask cannot be 0");
1378 				return -EINVAL;
1379 			}
1380 			info->labels = *labels;
1381 			break;
1382 		}
1383 #endif
1384 		case OVS_CT_ATTR_HELPER:
1385 			*helper = nla_data(a);
1386 			if (!memchr(*helper, '\0', nla_len(a))) {
1387 				OVS_NLERR(log, "Invalid conntrack helper");
1388 				return -EINVAL;
1389 			}
1390 			break;
1391 #if IS_ENABLED(CONFIG_NF_NAT)
1392 		case OVS_CT_ATTR_NAT: {
1393 			int err = parse_nat(a, info, log);
1394 
1395 			if (err)
1396 				return err;
1397 			break;
1398 		}
1399 #endif
1400 		case OVS_CT_ATTR_EVENTMASK:
1401 			info->have_eventmask = true;
1402 			info->eventmask = nla_get_u32(a);
1403 			break;
1404 #ifdef CONFIG_NF_CONNTRACK_TIMEOUT
1405 		case OVS_CT_ATTR_TIMEOUT:
1406 			memcpy(info->timeout, nla_data(a), nla_len(a));
1407 			if (!memchr(info->timeout, '\0', nla_len(a))) {
1408 				OVS_NLERR(log, "Invalid conntrack timeout");
1409 				return -EINVAL;
1410 			}
1411 			break;
1412 #endif
1413 
1414 		default:
1415 			OVS_NLERR(log, "Unknown conntrack attr (%d)",
1416 				  type);
1417 			return -EINVAL;
1418 		}
1419 	}
1420 
1421 #ifdef CONFIG_NF_CONNTRACK_MARK
1422 	if (!info->commit && info->mark.mask) {
1423 		OVS_NLERR(log,
1424 			  "Setting conntrack mark requires 'commit' flag.");
1425 		return -EINVAL;
1426 	}
1427 #endif
1428 #ifdef CONFIG_NF_CONNTRACK_LABELS
1429 	if (!info->commit && labels_nonzero(&info->labels.mask)) {
1430 		OVS_NLERR(log,
1431 			  "Setting conntrack labels requires 'commit' flag.");
1432 		return -EINVAL;
1433 	}
1434 #endif
1435 	if (rem > 0) {
1436 		OVS_NLERR(log, "Conntrack attr has %d unknown bytes", rem);
1437 		return -EINVAL;
1438 	}
1439 
1440 	return 0;
1441 }
1442 
1443 bool ovs_ct_verify(struct net *net, enum ovs_key_attr attr)
1444 {
1445 	if (attr == OVS_KEY_ATTR_CT_STATE)
1446 		return true;
1447 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1448 	    attr == OVS_KEY_ATTR_CT_ZONE)
1449 		return true;
1450 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1451 	    attr == OVS_KEY_ATTR_CT_MARK)
1452 		return true;
1453 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1454 	    attr == OVS_KEY_ATTR_CT_LABELS) {
1455 		struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
1456 
1457 		return ovs_net->xt_label;
1458 	}
1459 
1460 	return false;
1461 }
1462 
1463 int ovs_ct_copy_action(struct net *net, const struct nlattr *attr,
1464 		       const struct sw_flow_key *key,
1465 		       struct sw_flow_actions **sfa,  bool log)
1466 {
1467 	struct ovs_conntrack_info ct_info;
1468 	const char *helper = NULL;
1469 	u16 family;
1470 	int err;
1471 
1472 	family = key_to_nfproto(key);
1473 	if (family == NFPROTO_UNSPEC) {
1474 		OVS_NLERR(log, "ct family unspecified");
1475 		return -EINVAL;
1476 	}
1477 
1478 	memset(&ct_info, 0, sizeof(ct_info));
1479 	ct_info.family = family;
1480 
1481 	nf_ct_zone_init(&ct_info.zone, NF_CT_DEFAULT_ZONE_ID,
1482 			NF_CT_DEFAULT_ZONE_DIR, 0);
1483 
1484 	err = parse_ct(attr, &ct_info, &helper, log);
1485 	if (err)
1486 		return err;
1487 
1488 	/* Set up template for tracking connections in specific zones. */
1489 	ct_info.ct = nf_ct_tmpl_alloc(net, &ct_info.zone, GFP_KERNEL);
1490 	if (!ct_info.ct) {
1491 		OVS_NLERR(log, "Failed to allocate conntrack template");
1492 		return -ENOMEM;
1493 	}
1494 
1495 	if (ct_info.timeout[0]) {
1496 		if (nf_ct_set_timeout(net, ct_info.ct, family, key->ip.proto,
1497 				      ct_info.timeout))
1498 			pr_info_ratelimited("Failed to associated timeout "
1499 					    "policy `%s'\n", ct_info.timeout);
1500 		else
1501 			ct_info.nf_ct_timeout = rcu_dereference(
1502 				nf_ct_timeout_find(ct_info.ct)->timeout);
1503 
1504 	}
1505 
1506 	if (helper) {
1507 		err = nf_ct_add_helper(ct_info.ct, helper, ct_info.family,
1508 				       key->ip.proto, ct_info.nat, &ct_info.helper);
1509 		if (err) {
1510 			OVS_NLERR(log, "Failed to add %s helper %d", helper, err);
1511 			goto err_free_ct;
1512 		}
1513 	}
1514 
1515 	err = ovs_nla_add_action(sfa, OVS_ACTION_ATTR_CT, &ct_info,
1516 				 sizeof(ct_info), log);
1517 	if (err)
1518 		goto err_free_ct;
1519 
1520 	__set_bit(IPS_CONFIRMED_BIT, &ct_info.ct->status);
1521 	return 0;
1522 err_free_ct:
1523 	__ovs_ct_free_action(&ct_info);
1524 	return err;
1525 }
1526 
1527 #if IS_ENABLED(CONFIG_NF_NAT)
1528 static bool ovs_ct_nat_to_attr(const struct ovs_conntrack_info *info,
1529 			       struct sk_buff *skb)
1530 {
1531 	struct nlattr *start;
1532 
1533 	start = nla_nest_start_noflag(skb, OVS_CT_ATTR_NAT);
1534 	if (!start)
1535 		return false;
1536 
1537 	if (info->nat & OVS_CT_SRC_NAT) {
1538 		if (nla_put_flag(skb, OVS_NAT_ATTR_SRC))
1539 			return false;
1540 	} else if (info->nat & OVS_CT_DST_NAT) {
1541 		if (nla_put_flag(skb, OVS_NAT_ATTR_DST))
1542 			return false;
1543 	} else {
1544 		goto out;
1545 	}
1546 
1547 	if (info->range.flags & NF_NAT_RANGE_MAP_IPS) {
1548 		if (IS_ENABLED(CONFIG_NF_NAT) &&
1549 		    info->family == NFPROTO_IPV4) {
1550 			if (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MIN,
1551 					    info->range.min_addr.ip) ||
1552 			    (info->range.max_addr.ip
1553 			     != info->range.min_addr.ip &&
1554 			     (nla_put_in_addr(skb, OVS_NAT_ATTR_IP_MAX,
1555 					      info->range.max_addr.ip))))
1556 				return false;
1557 		} else if (IS_ENABLED(CONFIG_IPV6) &&
1558 			   info->family == NFPROTO_IPV6) {
1559 			if (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MIN,
1560 					     &info->range.min_addr.in6) ||
1561 			    (memcmp(&info->range.max_addr.in6,
1562 				    &info->range.min_addr.in6,
1563 				    sizeof(info->range.max_addr.in6)) &&
1564 			     (nla_put_in6_addr(skb, OVS_NAT_ATTR_IP_MAX,
1565 					       &info->range.max_addr.in6))))
1566 				return false;
1567 		} else {
1568 			return false;
1569 		}
1570 	}
1571 	if (info->range.flags & NF_NAT_RANGE_PROTO_SPECIFIED &&
1572 	    (nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MIN,
1573 			 ntohs(info->range.min_proto.all)) ||
1574 	     (info->range.max_proto.all != info->range.min_proto.all &&
1575 	      nla_put_u16(skb, OVS_NAT_ATTR_PROTO_MAX,
1576 			  ntohs(info->range.max_proto.all)))))
1577 		return false;
1578 
1579 	if (info->range.flags & NF_NAT_RANGE_PERSISTENT &&
1580 	    nla_put_flag(skb, OVS_NAT_ATTR_PERSISTENT))
1581 		return false;
1582 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM &&
1583 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_HASH))
1584 		return false;
1585 	if (info->range.flags & NF_NAT_RANGE_PROTO_RANDOM_FULLY &&
1586 	    nla_put_flag(skb, OVS_NAT_ATTR_PROTO_RANDOM))
1587 		return false;
1588 out:
1589 	nla_nest_end(skb, start);
1590 
1591 	return true;
1592 }
1593 #endif
1594 
1595 int ovs_ct_action_to_attr(const struct ovs_conntrack_info *ct_info,
1596 			  struct sk_buff *skb)
1597 {
1598 	struct nlattr *start;
1599 
1600 	start = nla_nest_start_noflag(skb, OVS_ACTION_ATTR_CT);
1601 	if (!start)
1602 		return -EMSGSIZE;
1603 
1604 	if (ct_info->commit && nla_put_flag(skb, ct_info->force
1605 					    ? OVS_CT_ATTR_FORCE_COMMIT
1606 					    : OVS_CT_ATTR_COMMIT))
1607 		return -EMSGSIZE;
1608 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1609 	    nla_put_u16(skb, OVS_CT_ATTR_ZONE, ct_info->zone.id))
1610 		return -EMSGSIZE;
1611 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) && ct_info->mark.mask &&
1612 	    nla_put(skb, OVS_CT_ATTR_MARK, sizeof(ct_info->mark),
1613 		    &ct_info->mark))
1614 		return -EMSGSIZE;
1615 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1616 	    labels_nonzero(&ct_info->labels.mask) &&
1617 	    nla_put(skb, OVS_CT_ATTR_LABELS, sizeof(ct_info->labels),
1618 		    &ct_info->labels))
1619 		return -EMSGSIZE;
1620 	if (ct_info->helper) {
1621 		if (nla_put_string(skb, OVS_CT_ATTR_HELPER,
1622 				   ct_info->helper->name))
1623 			return -EMSGSIZE;
1624 	}
1625 	if (ct_info->have_eventmask &&
1626 	    nla_put_u32(skb, OVS_CT_ATTR_EVENTMASK, ct_info->eventmask))
1627 		return -EMSGSIZE;
1628 	if (ct_info->timeout[0]) {
1629 		if (nla_put_string(skb, OVS_CT_ATTR_TIMEOUT, ct_info->timeout))
1630 			return -EMSGSIZE;
1631 	}
1632 
1633 #if IS_ENABLED(CONFIG_NF_NAT)
1634 	if (ct_info->nat && !ovs_ct_nat_to_attr(ct_info, skb))
1635 		return -EMSGSIZE;
1636 #endif
1637 	nla_nest_end(skb, start);
1638 
1639 	return 0;
1640 }
1641 
1642 void ovs_ct_free_action(const struct nlattr *a)
1643 {
1644 	struct ovs_conntrack_info *ct_info = nla_data(a);
1645 
1646 	__ovs_ct_free_action(ct_info);
1647 }
1648 
1649 static void __ovs_ct_free_action(struct ovs_conntrack_info *ct_info)
1650 {
1651 	if (ct_info->helper) {
1652 #if IS_ENABLED(CONFIG_NF_NAT)
1653 		if (ct_info->nat)
1654 			nf_nat_helper_put(ct_info->helper);
1655 #endif
1656 		nf_conntrack_helper_put(ct_info->helper);
1657 	}
1658 	if (ct_info->ct) {
1659 		if (ct_info->timeout[0])
1660 			nf_ct_destroy_timeout(ct_info->ct);
1661 		nf_ct_tmpl_free(ct_info->ct);
1662 	}
1663 }
1664 
1665 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
1666 static int ovs_ct_limit_init(struct net *net, struct ovs_net *ovs_net)
1667 {
1668 	int i, err;
1669 
1670 	ovs_net->ct_limit_info = kmalloc(sizeof(*ovs_net->ct_limit_info),
1671 					 GFP_KERNEL);
1672 	if (!ovs_net->ct_limit_info)
1673 		return -ENOMEM;
1674 
1675 	ovs_net->ct_limit_info->default_limit = OVS_CT_LIMIT_DEFAULT;
1676 	ovs_net->ct_limit_info->limits =
1677 		kmalloc_array(CT_LIMIT_HASH_BUCKETS, sizeof(struct hlist_head),
1678 			      GFP_KERNEL);
1679 	if (!ovs_net->ct_limit_info->limits) {
1680 		kfree(ovs_net->ct_limit_info);
1681 		return -ENOMEM;
1682 	}
1683 
1684 	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; i++)
1685 		INIT_HLIST_HEAD(&ovs_net->ct_limit_info->limits[i]);
1686 
1687 	ovs_net->ct_limit_info->data =
1688 		nf_conncount_init(net, NFPROTO_INET, sizeof(u32));
1689 
1690 	if (IS_ERR(ovs_net->ct_limit_info->data)) {
1691 		err = PTR_ERR(ovs_net->ct_limit_info->data);
1692 		kfree(ovs_net->ct_limit_info->limits);
1693 		kfree(ovs_net->ct_limit_info);
1694 		pr_err("openvswitch: failed to init nf_conncount %d\n", err);
1695 		return err;
1696 	}
1697 	return 0;
1698 }
1699 
1700 static void ovs_ct_limit_exit(struct net *net, struct ovs_net *ovs_net)
1701 {
1702 	const struct ovs_ct_limit_info *info = ovs_net->ct_limit_info;
1703 	int i;
1704 
1705 	nf_conncount_destroy(net, NFPROTO_INET, info->data);
1706 	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1707 		struct hlist_head *head = &info->limits[i];
1708 		struct ovs_ct_limit *ct_limit;
1709 
1710 		hlist_for_each_entry_rcu(ct_limit, head, hlist_node,
1711 					 lockdep_ovsl_is_held())
1712 			kfree_rcu(ct_limit, rcu);
1713 	}
1714 	kfree(info->limits);
1715 	kfree(info);
1716 }
1717 
1718 static struct sk_buff *
1719 ovs_ct_limit_cmd_reply_start(struct genl_info *info, u8 cmd,
1720 			     struct ovs_header **ovs_reply_header)
1721 {
1722 	struct ovs_header *ovs_header = info->userhdr;
1723 	struct sk_buff *skb;
1724 
1725 	skb = genlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1726 	if (!skb)
1727 		return ERR_PTR(-ENOMEM);
1728 
1729 	*ovs_reply_header = genlmsg_put(skb, info->snd_portid,
1730 					info->snd_seq,
1731 					&dp_ct_limit_genl_family, 0, cmd);
1732 
1733 	if (!*ovs_reply_header) {
1734 		nlmsg_free(skb);
1735 		return ERR_PTR(-EMSGSIZE);
1736 	}
1737 	(*ovs_reply_header)->dp_ifindex = ovs_header->dp_ifindex;
1738 
1739 	return skb;
1740 }
1741 
1742 static bool check_zone_id(int zone_id, u16 *pzone)
1743 {
1744 	if (zone_id >= 0 && zone_id <= 65535) {
1745 		*pzone = (u16)zone_id;
1746 		return true;
1747 	}
1748 	return false;
1749 }
1750 
1751 static int ovs_ct_limit_set_zone_limit(struct nlattr *nla_zone_limit,
1752 				       struct ovs_ct_limit_info *info)
1753 {
1754 	struct ovs_zone_limit *zone_limit;
1755 	int rem;
1756 	u16 zone;
1757 
1758 	rem = NLA_ALIGN(nla_len(nla_zone_limit));
1759 	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1760 
1761 	while (rem >= sizeof(*zone_limit)) {
1762 		if (unlikely(zone_limit->zone_id ==
1763 				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1764 			ovs_lock();
1765 			info->default_limit = zone_limit->limit;
1766 			ovs_unlock();
1767 		} else if (unlikely(!check_zone_id(
1768 				zone_limit->zone_id, &zone))) {
1769 			OVS_NLERR(true, "zone id is out of range");
1770 		} else {
1771 			struct ovs_ct_limit *ct_limit;
1772 
1773 			ct_limit = kmalloc(sizeof(*ct_limit),
1774 					   GFP_KERNEL_ACCOUNT);
1775 			if (!ct_limit)
1776 				return -ENOMEM;
1777 
1778 			ct_limit->zone = zone;
1779 			ct_limit->limit = zone_limit->limit;
1780 
1781 			ovs_lock();
1782 			ct_limit_set(info, ct_limit);
1783 			ovs_unlock();
1784 		}
1785 		rem -= NLA_ALIGN(sizeof(*zone_limit));
1786 		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1787 				NLA_ALIGN(sizeof(*zone_limit)));
1788 	}
1789 
1790 	if (rem)
1791 		OVS_NLERR(true, "set zone limit has %d unknown bytes", rem);
1792 
1793 	return 0;
1794 }
1795 
1796 static int ovs_ct_limit_del_zone_limit(struct nlattr *nla_zone_limit,
1797 				       struct ovs_ct_limit_info *info)
1798 {
1799 	struct ovs_zone_limit *zone_limit;
1800 	int rem;
1801 	u16 zone;
1802 
1803 	rem = NLA_ALIGN(nla_len(nla_zone_limit));
1804 	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1805 
1806 	while (rem >= sizeof(*zone_limit)) {
1807 		if (unlikely(zone_limit->zone_id ==
1808 				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1809 			ovs_lock();
1810 			info->default_limit = OVS_CT_LIMIT_DEFAULT;
1811 			ovs_unlock();
1812 		} else if (unlikely(!check_zone_id(
1813 				zone_limit->zone_id, &zone))) {
1814 			OVS_NLERR(true, "zone id is out of range");
1815 		} else {
1816 			ovs_lock();
1817 			ct_limit_del(info, zone);
1818 			ovs_unlock();
1819 		}
1820 		rem -= NLA_ALIGN(sizeof(*zone_limit));
1821 		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1822 				NLA_ALIGN(sizeof(*zone_limit)));
1823 	}
1824 
1825 	if (rem)
1826 		OVS_NLERR(true, "del zone limit has %d unknown bytes", rem);
1827 
1828 	return 0;
1829 }
1830 
1831 static int ovs_ct_limit_get_default_limit(struct ovs_ct_limit_info *info,
1832 					  struct sk_buff *reply)
1833 {
1834 	struct ovs_zone_limit zone_limit = {
1835 		.zone_id = OVS_ZONE_LIMIT_DEFAULT_ZONE,
1836 		.limit   = info->default_limit,
1837 	};
1838 
1839 	return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
1840 }
1841 
1842 static int __ovs_ct_limit_get_zone_limit(struct net *net,
1843 					 struct nf_conncount_data *data,
1844 					 u16 zone_id, u32 limit,
1845 					 struct sk_buff *reply)
1846 {
1847 	struct nf_conntrack_zone ct_zone;
1848 	struct ovs_zone_limit zone_limit;
1849 	u32 conncount_key = zone_id;
1850 
1851 	zone_limit.zone_id = zone_id;
1852 	zone_limit.limit = limit;
1853 	nf_ct_zone_init(&ct_zone, zone_id, NF_CT_DEFAULT_ZONE_DIR, 0);
1854 
1855 	zone_limit.count = nf_conncount_count(net, data, &conncount_key, NULL,
1856 					      &ct_zone);
1857 	return nla_put_nohdr(reply, sizeof(zone_limit), &zone_limit);
1858 }
1859 
1860 static int ovs_ct_limit_get_zone_limit(struct net *net,
1861 				       struct nlattr *nla_zone_limit,
1862 				       struct ovs_ct_limit_info *info,
1863 				       struct sk_buff *reply)
1864 {
1865 	struct ovs_zone_limit *zone_limit;
1866 	int rem, err;
1867 	u32 limit;
1868 	u16 zone;
1869 
1870 	rem = NLA_ALIGN(nla_len(nla_zone_limit));
1871 	zone_limit = (struct ovs_zone_limit *)nla_data(nla_zone_limit);
1872 
1873 	while (rem >= sizeof(*zone_limit)) {
1874 		if (unlikely(zone_limit->zone_id ==
1875 				OVS_ZONE_LIMIT_DEFAULT_ZONE)) {
1876 			err = ovs_ct_limit_get_default_limit(info, reply);
1877 			if (err)
1878 				return err;
1879 		} else if (unlikely(!check_zone_id(zone_limit->zone_id,
1880 							&zone))) {
1881 			OVS_NLERR(true, "zone id is out of range");
1882 		} else {
1883 			rcu_read_lock();
1884 			limit = ct_limit_get(info, zone);
1885 			rcu_read_unlock();
1886 
1887 			err = __ovs_ct_limit_get_zone_limit(
1888 				net, info->data, zone, limit, reply);
1889 			if (err)
1890 				return err;
1891 		}
1892 		rem -= NLA_ALIGN(sizeof(*zone_limit));
1893 		zone_limit = (struct ovs_zone_limit *)((u8 *)zone_limit +
1894 				NLA_ALIGN(sizeof(*zone_limit)));
1895 	}
1896 
1897 	if (rem)
1898 		OVS_NLERR(true, "get zone limit has %d unknown bytes", rem);
1899 
1900 	return 0;
1901 }
1902 
1903 static int ovs_ct_limit_get_all_zone_limit(struct net *net,
1904 					   struct ovs_ct_limit_info *info,
1905 					   struct sk_buff *reply)
1906 {
1907 	struct ovs_ct_limit *ct_limit;
1908 	struct hlist_head *head;
1909 	int i, err = 0;
1910 
1911 	err = ovs_ct_limit_get_default_limit(info, reply);
1912 	if (err)
1913 		return err;
1914 
1915 	rcu_read_lock();
1916 	for (i = 0; i < CT_LIMIT_HASH_BUCKETS; ++i) {
1917 		head = &info->limits[i];
1918 		hlist_for_each_entry_rcu(ct_limit, head, hlist_node) {
1919 			err = __ovs_ct_limit_get_zone_limit(net, info->data,
1920 				ct_limit->zone, ct_limit->limit, reply);
1921 			if (err)
1922 				goto exit_err;
1923 		}
1924 	}
1925 
1926 exit_err:
1927 	rcu_read_unlock();
1928 	return err;
1929 }
1930 
1931 static int ovs_ct_limit_cmd_set(struct sk_buff *skb, struct genl_info *info)
1932 {
1933 	struct nlattr **a = info->attrs;
1934 	struct sk_buff *reply;
1935 	struct ovs_header *ovs_reply_header;
1936 	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
1937 	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1938 	int err;
1939 
1940 	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_SET,
1941 					     &ovs_reply_header);
1942 	if (IS_ERR(reply))
1943 		return PTR_ERR(reply);
1944 
1945 	if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
1946 		err = -EINVAL;
1947 		goto exit_err;
1948 	}
1949 
1950 	err = ovs_ct_limit_set_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
1951 					  ct_limit_info);
1952 	if (err)
1953 		goto exit_err;
1954 
1955 	static_branch_enable(&ovs_ct_limit_enabled);
1956 
1957 	genlmsg_end(reply, ovs_reply_header);
1958 	return genlmsg_reply(reply, info);
1959 
1960 exit_err:
1961 	nlmsg_free(reply);
1962 	return err;
1963 }
1964 
1965 static int ovs_ct_limit_cmd_del(struct sk_buff *skb, struct genl_info *info)
1966 {
1967 	struct nlattr **a = info->attrs;
1968 	struct sk_buff *reply;
1969 	struct ovs_header *ovs_reply_header;
1970 	struct ovs_net *ovs_net = net_generic(sock_net(skb->sk), ovs_net_id);
1971 	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
1972 	int err;
1973 
1974 	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_DEL,
1975 					     &ovs_reply_header);
1976 	if (IS_ERR(reply))
1977 		return PTR_ERR(reply);
1978 
1979 	if (!a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
1980 		err = -EINVAL;
1981 		goto exit_err;
1982 	}
1983 
1984 	err = ovs_ct_limit_del_zone_limit(a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT],
1985 					  ct_limit_info);
1986 	if (err)
1987 		goto exit_err;
1988 
1989 	genlmsg_end(reply, ovs_reply_header);
1990 	return genlmsg_reply(reply, info);
1991 
1992 exit_err:
1993 	nlmsg_free(reply);
1994 	return err;
1995 }
1996 
1997 static int ovs_ct_limit_cmd_get(struct sk_buff *skb, struct genl_info *info)
1998 {
1999 	struct nlattr **a = info->attrs;
2000 	struct nlattr *nla_reply;
2001 	struct sk_buff *reply;
2002 	struct ovs_header *ovs_reply_header;
2003 	struct net *net = sock_net(skb->sk);
2004 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2005 	struct ovs_ct_limit_info *ct_limit_info = ovs_net->ct_limit_info;
2006 	int err;
2007 
2008 	reply = ovs_ct_limit_cmd_reply_start(info, OVS_CT_LIMIT_CMD_GET,
2009 					     &ovs_reply_header);
2010 	if (IS_ERR(reply))
2011 		return PTR_ERR(reply);
2012 
2013 	nla_reply = nla_nest_start_noflag(reply, OVS_CT_LIMIT_ATTR_ZONE_LIMIT);
2014 	if (!nla_reply) {
2015 		err = -EMSGSIZE;
2016 		goto exit_err;
2017 	}
2018 
2019 	if (a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT]) {
2020 		err = ovs_ct_limit_get_zone_limit(
2021 			net, a[OVS_CT_LIMIT_ATTR_ZONE_LIMIT], ct_limit_info,
2022 			reply);
2023 		if (err)
2024 			goto exit_err;
2025 	} else {
2026 		err = ovs_ct_limit_get_all_zone_limit(net, ct_limit_info,
2027 						      reply);
2028 		if (err)
2029 			goto exit_err;
2030 	}
2031 
2032 	nla_nest_end(reply, nla_reply);
2033 	genlmsg_end(reply, ovs_reply_header);
2034 	return genlmsg_reply(reply, info);
2035 
2036 exit_err:
2037 	nlmsg_free(reply);
2038 	return err;
2039 }
2040 
2041 static const struct genl_small_ops ct_limit_genl_ops[] = {
2042 	{ .cmd = OVS_CT_LIMIT_CMD_SET,
2043 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2044 		.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2045 					       * privilege.
2046 					       */
2047 		.doit = ovs_ct_limit_cmd_set,
2048 	},
2049 	{ .cmd = OVS_CT_LIMIT_CMD_DEL,
2050 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2051 		.flags = GENL_UNS_ADMIN_PERM, /* Requires CAP_NET_ADMIN
2052 					       * privilege.
2053 					       */
2054 		.doit = ovs_ct_limit_cmd_del,
2055 	},
2056 	{ .cmd = OVS_CT_LIMIT_CMD_GET,
2057 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
2058 		.flags = 0,		  /* OK for unprivileged users. */
2059 		.doit = ovs_ct_limit_cmd_get,
2060 	},
2061 };
2062 
2063 static const struct genl_multicast_group ovs_ct_limit_multicast_group = {
2064 	.name = OVS_CT_LIMIT_MCGROUP,
2065 };
2066 
2067 struct genl_family dp_ct_limit_genl_family __ro_after_init = {
2068 	.hdrsize = sizeof(struct ovs_header),
2069 	.name = OVS_CT_LIMIT_FAMILY,
2070 	.version = OVS_CT_LIMIT_VERSION,
2071 	.maxattr = OVS_CT_LIMIT_ATTR_MAX,
2072 	.policy = ct_limit_policy,
2073 	.netnsok = true,
2074 	.parallel_ops = true,
2075 	.small_ops = ct_limit_genl_ops,
2076 	.n_small_ops = ARRAY_SIZE(ct_limit_genl_ops),
2077 	.resv_start_op = OVS_CT_LIMIT_CMD_GET + 1,
2078 	.mcgrps = &ovs_ct_limit_multicast_group,
2079 	.n_mcgrps = 1,
2080 	.module = THIS_MODULE,
2081 };
2082 #endif
2083 
2084 int ovs_ct_init(struct net *net)
2085 {
2086 	unsigned int n_bits = sizeof(struct ovs_key_ct_labels) * BITS_PER_BYTE;
2087 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2088 
2089 	if (nf_connlabels_get(net, n_bits - 1)) {
2090 		ovs_net->xt_label = false;
2091 		OVS_NLERR(true, "Failed to set connlabel length");
2092 	} else {
2093 		ovs_net->xt_label = true;
2094 	}
2095 
2096 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2097 	return ovs_ct_limit_init(net, ovs_net);
2098 #else
2099 	return 0;
2100 #endif
2101 }
2102 
2103 void ovs_ct_exit(struct net *net)
2104 {
2105 	struct ovs_net *ovs_net = net_generic(net, ovs_net_id);
2106 
2107 #if	IS_ENABLED(CONFIG_NETFILTER_CONNCOUNT)
2108 	ovs_ct_limit_exit(net, ovs_net);
2109 #endif
2110 
2111 	if (ovs_net->xt_label)
2112 		nf_connlabels_put(net);
2113 }
2114