xref: /linux/net/sched/act_ct.c (revision 2634682fdffd9ba6e74b76be8aa91cf8b2e05c41)
1 // SPDX-License-Identifier: GPL-2.0 OR Linux-OpenIB
2 /* -
3  * net/sched/act_ct.c  Connection Tracking action
4  *
5  * Authors:   Paul Blakey <paulb@mellanox.com>
6  *            Yossi Kuperman <yossiku@mellanox.com>
7  *            Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
8  */
9 
10 #include <linux/module.h>
11 #include <linux/init.h>
12 #include <linux/kernel.h>
13 #include <linux/skbuff.h>
14 #include <linux/rtnetlink.h>
15 #include <linux/pkt_cls.h>
16 #include <linux/ip.h>
17 #include <linux/ipv6.h>
18 #include <linux/rhashtable.h>
19 #include <net/netlink.h>
20 #include <net/pkt_sched.h>
21 #include <net/pkt_cls.h>
22 #include <net/act_api.h>
23 #include <net/ip.h>
24 #include <net/ipv6_frag.h>
25 #include <uapi/linux/tc_act/tc_ct.h>
26 #include <net/tc_act/tc_ct.h>
27 
28 #include <net/netfilter/nf_flow_table.h>
29 #include <net/netfilter/nf_conntrack.h>
30 #include <net/netfilter/nf_conntrack_core.h>
31 #include <net/netfilter/nf_conntrack_zones.h>
32 #include <net/netfilter/nf_conntrack_helper.h>
33 #include <net/netfilter/nf_conntrack_acct.h>
34 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
35 #include <uapi/linux/netfilter/nf_nat.h>
36 
37 static struct workqueue_struct *act_ct_wq;
38 static struct rhashtable zones_ht;
39 static DEFINE_MUTEX(zones_mutex);
40 
41 struct tcf_ct_flow_table {
42 	struct rhash_head node; /* In zones tables */
43 
44 	struct rcu_work rwork;
45 	struct nf_flowtable nf_ft;
46 	refcount_t ref;
47 	u16 zone;
48 
49 	bool dying;
50 };
51 
52 static const struct rhashtable_params zones_params = {
53 	.head_offset = offsetof(struct tcf_ct_flow_table, node),
54 	.key_offset = offsetof(struct tcf_ct_flow_table, zone),
55 	.key_len = sizeof_field(struct tcf_ct_flow_table, zone),
56 	.automatic_shrinking = true,
57 };
58 
59 static struct flow_action_entry *
60 tcf_ct_flow_table_flow_action_get_next(struct flow_action *flow_action)
61 {
62 	int i = flow_action->num_entries++;
63 
64 	return &flow_action->entries[i];
65 }
66 
67 static void tcf_ct_add_mangle_action(struct flow_action *action,
68 				     enum flow_action_mangle_base htype,
69 				     u32 offset,
70 				     u32 mask,
71 				     u32 val)
72 {
73 	struct flow_action_entry *entry;
74 
75 	entry = tcf_ct_flow_table_flow_action_get_next(action);
76 	entry->id = FLOW_ACTION_MANGLE;
77 	entry->mangle.htype = htype;
78 	entry->mangle.mask = ~mask;
79 	entry->mangle.offset = offset;
80 	entry->mangle.val = val;
81 }
82 
83 /* The following nat helper functions check if the inverted reverse tuple
84  * (target) is different then the current dir tuple - meaning nat for ports
85  * and/or ip is needed, and add the relevant mangle actions.
86  */
87 static void
88 tcf_ct_flow_table_add_action_nat_ipv4(const struct nf_conntrack_tuple *tuple,
89 				      struct nf_conntrack_tuple target,
90 				      struct flow_action *action)
91 {
92 	if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
93 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
94 					 offsetof(struct iphdr, saddr),
95 					 0xFFFFFFFF,
96 					 be32_to_cpu(target.src.u3.ip));
97 	if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
98 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP4,
99 					 offsetof(struct iphdr, daddr),
100 					 0xFFFFFFFF,
101 					 be32_to_cpu(target.dst.u3.ip));
102 }
103 
104 static void
105 tcf_ct_add_ipv6_addr_mangle_action(struct flow_action *action,
106 				   union nf_inet_addr *addr,
107 				   u32 offset)
108 {
109 	int i;
110 
111 	for (i = 0; i < sizeof(struct in6_addr) / sizeof(u32); i++)
112 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_IP6,
113 					 i * sizeof(u32) + offset,
114 					 0xFFFFFFFF, be32_to_cpu(addr->ip6[i]));
115 }
116 
117 static void
118 tcf_ct_flow_table_add_action_nat_ipv6(const struct nf_conntrack_tuple *tuple,
119 				      struct nf_conntrack_tuple target,
120 				      struct flow_action *action)
121 {
122 	if (memcmp(&target.src.u3, &tuple->src.u3, sizeof(target.src.u3)))
123 		tcf_ct_add_ipv6_addr_mangle_action(action, &target.src.u3,
124 						   offsetof(struct ipv6hdr,
125 							    saddr));
126 	if (memcmp(&target.dst.u3, &tuple->dst.u3, sizeof(target.dst.u3)))
127 		tcf_ct_add_ipv6_addr_mangle_action(action, &target.dst.u3,
128 						   offsetof(struct ipv6hdr,
129 							    daddr));
130 }
131 
132 static void
133 tcf_ct_flow_table_add_action_nat_tcp(const struct nf_conntrack_tuple *tuple,
134 				     struct nf_conntrack_tuple target,
135 				     struct flow_action *action)
136 {
137 	__be16 target_src = target.src.u.tcp.port;
138 	__be16 target_dst = target.dst.u.tcp.port;
139 
140 	if (target_src != tuple->src.u.tcp.port)
141 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
142 					 offsetof(struct tcphdr, source),
143 					 0xFFFF, be16_to_cpu(target_src));
144 	if (target_dst != tuple->dst.u.tcp.port)
145 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
146 					 offsetof(struct tcphdr, dest),
147 					 0xFFFF, be16_to_cpu(target_dst));
148 }
149 
150 static void
151 tcf_ct_flow_table_add_action_nat_udp(const struct nf_conntrack_tuple *tuple,
152 				     struct nf_conntrack_tuple target,
153 				     struct flow_action *action)
154 {
155 	__be16 target_src = target.src.u.udp.port;
156 	__be16 target_dst = target.dst.u.udp.port;
157 
158 	if (target_src != tuple->src.u.udp.port)
159 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
160 					 offsetof(struct udphdr, source),
161 					 0xFFFF, be16_to_cpu(target_src));
162 	if (target_dst != tuple->dst.u.udp.port)
163 		tcf_ct_add_mangle_action(action, FLOW_ACT_MANGLE_HDR_TYPE_TCP,
164 					 offsetof(struct udphdr, dest),
165 					 0xFFFF, be16_to_cpu(target_dst));
166 }
167 
168 static void tcf_ct_flow_table_add_action_meta(struct nf_conn *ct,
169 					      enum ip_conntrack_dir dir,
170 					      struct flow_action *action)
171 {
172 	struct nf_conn_labels *ct_labels;
173 	struct flow_action_entry *entry;
174 	enum ip_conntrack_info ctinfo;
175 	u32 *act_ct_labels;
176 
177 	entry = tcf_ct_flow_table_flow_action_get_next(action);
178 	entry->id = FLOW_ACTION_CT_METADATA;
179 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
180 	entry->ct_metadata.mark = ct->mark;
181 #endif
182 	ctinfo = dir == IP_CT_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
183 					     IP_CT_ESTABLISHED_REPLY;
184 	/* aligns with the CT reference on the SKB nf_ct_set */
185 	entry->ct_metadata.cookie = (unsigned long)ct | ctinfo;
186 
187 	act_ct_labels = entry->ct_metadata.labels;
188 	ct_labels = nf_ct_labels_find(ct);
189 	if (ct_labels)
190 		memcpy(act_ct_labels, ct_labels->bits, NF_CT_LABELS_MAX_SIZE);
191 	else
192 		memset(act_ct_labels, 0, NF_CT_LABELS_MAX_SIZE);
193 }
194 
195 static int tcf_ct_flow_table_add_action_nat(struct net *net,
196 					    struct nf_conn *ct,
197 					    enum ip_conntrack_dir dir,
198 					    struct flow_action *action)
199 {
200 	const struct nf_conntrack_tuple *tuple = &ct->tuplehash[dir].tuple;
201 	struct nf_conntrack_tuple target;
202 
203 	if (!(ct->status & IPS_NAT_MASK))
204 		return 0;
205 
206 	nf_ct_invert_tuple(&target, &ct->tuplehash[!dir].tuple);
207 
208 	switch (tuple->src.l3num) {
209 	case NFPROTO_IPV4:
210 		tcf_ct_flow_table_add_action_nat_ipv4(tuple, target,
211 						      action);
212 		break;
213 	case NFPROTO_IPV6:
214 		tcf_ct_flow_table_add_action_nat_ipv6(tuple, target,
215 						      action);
216 		break;
217 	default:
218 		return -EOPNOTSUPP;
219 	}
220 
221 	switch (nf_ct_protonum(ct)) {
222 	case IPPROTO_TCP:
223 		tcf_ct_flow_table_add_action_nat_tcp(tuple, target, action);
224 		break;
225 	case IPPROTO_UDP:
226 		tcf_ct_flow_table_add_action_nat_udp(tuple, target, action);
227 		break;
228 	default:
229 		return -EOPNOTSUPP;
230 	}
231 
232 	return 0;
233 }
234 
235 static int tcf_ct_flow_table_fill_actions(struct net *net,
236 					  const struct flow_offload *flow,
237 					  enum flow_offload_tuple_dir tdir,
238 					  struct nf_flow_rule *flow_rule)
239 {
240 	struct flow_action *action = &flow_rule->rule->action;
241 	int num_entries = action->num_entries;
242 	struct nf_conn *ct = flow->ct;
243 	enum ip_conntrack_dir dir;
244 	int i, err;
245 
246 	switch (tdir) {
247 	case FLOW_OFFLOAD_DIR_ORIGINAL:
248 		dir = IP_CT_DIR_ORIGINAL;
249 		break;
250 	case FLOW_OFFLOAD_DIR_REPLY:
251 		dir = IP_CT_DIR_REPLY;
252 		break;
253 	default:
254 		return -EOPNOTSUPP;
255 	}
256 
257 	err = tcf_ct_flow_table_add_action_nat(net, ct, dir, action);
258 	if (err)
259 		goto err_nat;
260 
261 	tcf_ct_flow_table_add_action_meta(ct, dir, action);
262 	return 0;
263 
264 err_nat:
265 	/* Clear filled actions */
266 	for (i = num_entries; i < action->num_entries; i++)
267 		memset(&action->entries[i], 0, sizeof(action->entries[i]));
268 	action->num_entries = num_entries;
269 
270 	return err;
271 }
272 
273 static struct nf_flowtable_type flowtable_ct = {
274 	.action		= tcf_ct_flow_table_fill_actions,
275 	.owner		= THIS_MODULE,
276 };
277 
278 static int tcf_ct_flow_table_get(struct tcf_ct_params *params)
279 {
280 	struct tcf_ct_flow_table *ct_ft;
281 	int err = -ENOMEM;
282 
283 	mutex_lock(&zones_mutex);
284 	ct_ft = rhashtable_lookup_fast(&zones_ht, &params->zone, zones_params);
285 	if (ct_ft && refcount_inc_not_zero(&ct_ft->ref))
286 		goto out_unlock;
287 
288 	ct_ft = kzalloc(sizeof(*ct_ft), GFP_KERNEL);
289 	if (!ct_ft)
290 		goto err_alloc;
291 	refcount_set(&ct_ft->ref, 1);
292 
293 	ct_ft->zone = params->zone;
294 	err = rhashtable_insert_fast(&zones_ht, &ct_ft->node, zones_params);
295 	if (err)
296 		goto err_insert;
297 
298 	ct_ft->nf_ft.type = &flowtable_ct;
299 	ct_ft->nf_ft.flags |= NF_FLOWTABLE_HW_OFFLOAD;
300 	err = nf_flow_table_init(&ct_ft->nf_ft);
301 	if (err)
302 		goto err_init;
303 
304 	__module_get(THIS_MODULE);
305 out_unlock:
306 	params->ct_ft = ct_ft;
307 	params->nf_ft = &ct_ft->nf_ft;
308 	mutex_unlock(&zones_mutex);
309 
310 	return 0;
311 
312 err_init:
313 	rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
314 err_insert:
315 	kfree(ct_ft);
316 err_alloc:
317 	mutex_unlock(&zones_mutex);
318 	return err;
319 }
320 
321 static void tcf_ct_flow_table_cleanup_work(struct work_struct *work)
322 {
323 	struct tcf_ct_flow_table *ct_ft;
324 
325 	ct_ft = container_of(to_rcu_work(work), struct tcf_ct_flow_table,
326 			     rwork);
327 	nf_flow_table_free(&ct_ft->nf_ft);
328 	kfree(ct_ft);
329 
330 	module_put(THIS_MODULE);
331 }
332 
333 static void tcf_ct_flow_table_put(struct tcf_ct_params *params)
334 {
335 	struct tcf_ct_flow_table *ct_ft = params->ct_ft;
336 
337 	if (refcount_dec_and_test(&params->ct_ft->ref)) {
338 		rhashtable_remove_fast(&zones_ht, &ct_ft->node, zones_params);
339 		INIT_RCU_WORK(&ct_ft->rwork, tcf_ct_flow_table_cleanup_work);
340 		queue_rcu_work(act_ct_wq, &ct_ft->rwork);
341 	}
342 }
343 
344 static void tcf_ct_flow_table_add(struct tcf_ct_flow_table *ct_ft,
345 				  struct nf_conn *ct,
346 				  bool tcp)
347 {
348 	struct flow_offload *entry;
349 	int err;
350 
351 	if (test_and_set_bit(IPS_OFFLOAD_BIT, &ct->status))
352 		return;
353 
354 	entry = flow_offload_alloc(ct);
355 	if (!entry) {
356 		WARN_ON_ONCE(1);
357 		goto err_alloc;
358 	}
359 
360 	if (tcp) {
361 		ct->proto.tcp.seen[0].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
362 		ct->proto.tcp.seen[1].flags |= IP_CT_TCP_FLAG_BE_LIBERAL;
363 	}
364 
365 	err = flow_offload_add(&ct_ft->nf_ft, entry);
366 	if (err)
367 		goto err_add;
368 
369 	return;
370 
371 err_add:
372 	flow_offload_free(entry);
373 err_alloc:
374 	clear_bit(IPS_OFFLOAD_BIT, &ct->status);
375 }
376 
377 static void tcf_ct_flow_table_process_conn(struct tcf_ct_flow_table *ct_ft,
378 					   struct nf_conn *ct,
379 					   enum ip_conntrack_info ctinfo)
380 {
381 	bool tcp = false;
382 
383 	if (ctinfo != IP_CT_ESTABLISHED && ctinfo != IP_CT_ESTABLISHED_REPLY)
384 		return;
385 
386 	switch (nf_ct_protonum(ct)) {
387 	case IPPROTO_TCP:
388 		tcp = true;
389 		if (ct->proto.tcp.state != TCP_CONNTRACK_ESTABLISHED)
390 			return;
391 		break;
392 	case IPPROTO_UDP:
393 		break;
394 	default:
395 		return;
396 	}
397 
398 	if (nf_ct_ext_exist(ct, NF_CT_EXT_HELPER) ||
399 	    ct->status & IPS_SEQ_ADJUST)
400 		return;
401 
402 	tcf_ct_flow_table_add(ct_ft, ct, tcp);
403 }
404 
405 static bool
406 tcf_ct_flow_table_fill_tuple_ipv4(struct sk_buff *skb,
407 				  struct flow_offload_tuple *tuple,
408 				  struct tcphdr **tcph)
409 {
410 	struct flow_ports *ports;
411 	unsigned int thoff;
412 	struct iphdr *iph;
413 
414 	if (!pskb_network_may_pull(skb, sizeof(*iph)))
415 		return false;
416 
417 	iph = ip_hdr(skb);
418 	thoff = iph->ihl * 4;
419 
420 	if (ip_is_fragment(iph) ||
421 	    unlikely(thoff != sizeof(struct iphdr)))
422 		return false;
423 
424 	if (iph->protocol != IPPROTO_TCP &&
425 	    iph->protocol != IPPROTO_UDP)
426 		return false;
427 
428 	if (iph->ttl <= 1)
429 		return false;
430 
431 	if (!pskb_network_may_pull(skb, iph->protocol == IPPROTO_TCP ?
432 					thoff + sizeof(struct tcphdr) :
433 					thoff + sizeof(*ports)))
434 		return false;
435 
436 	iph = ip_hdr(skb);
437 	if (iph->protocol == IPPROTO_TCP)
438 		*tcph = (void *)(skb_network_header(skb) + thoff);
439 
440 	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
441 	tuple->src_v4.s_addr = iph->saddr;
442 	tuple->dst_v4.s_addr = iph->daddr;
443 	tuple->src_port = ports->source;
444 	tuple->dst_port = ports->dest;
445 	tuple->l3proto = AF_INET;
446 	tuple->l4proto = iph->protocol;
447 
448 	return true;
449 }
450 
451 static bool
452 tcf_ct_flow_table_fill_tuple_ipv6(struct sk_buff *skb,
453 				  struct flow_offload_tuple *tuple,
454 				  struct tcphdr **tcph)
455 {
456 	struct flow_ports *ports;
457 	struct ipv6hdr *ip6h;
458 	unsigned int thoff;
459 
460 	if (!pskb_network_may_pull(skb, sizeof(*ip6h)))
461 		return false;
462 
463 	ip6h = ipv6_hdr(skb);
464 
465 	if (ip6h->nexthdr != IPPROTO_TCP &&
466 	    ip6h->nexthdr != IPPROTO_UDP)
467 		return false;
468 
469 	if (ip6h->hop_limit <= 1)
470 		return false;
471 
472 	thoff = sizeof(*ip6h);
473 	if (!pskb_network_may_pull(skb, ip6h->nexthdr == IPPROTO_TCP ?
474 					thoff + sizeof(struct tcphdr) :
475 					thoff + sizeof(*ports)))
476 		return false;
477 
478 	ip6h = ipv6_hdr(skb);
479 	if (ip6h->nexthdr == IPPROTO_TCP)
480 		*tcph = (void *)(skb_network_header(skb) + thoff);
481 
482 	ports = (struct flow_ports *)(skb_network_header(skb) + thoff);
483 	tuple->src_v6 = ip6h->saddr;
484 	tuple->dst_v6 = ip6h->daddr;
485 	tuple->src_port = ports->source;
486 	tuple->dst_port = ports->dest;
487 	tuple->l3proto = AF_INET6;
488 	tuple->l4proto = ip6h->nexthdr;
489 
490 	return true;
491 }
492 
493 static bool tcf_ct_flow_table_lookup(struct tcf_ct_params *p,
494 				     struct sk_buff *skb,
495 				     u8 family)
496 {
497 	struct nf_flowtable *nf_ft = &p->ct_ft->nf_ft;
498 	struct flow_offload_tuple_rhash *tuplehash;
499 	struct flow_offload_tuple tuple = {};
500 	enum ip_conntrack_info ctinfo;
501 	struct tcphdr *tcph = NULL;
502 	struct flow_offload *flow;
503 	struct nf_conn *ct;
504 	u8 dir;
505 
506 	/* Previously seen or loopback */
507 	ct = nf_ct_get(skb, &ctinfo);
508 	if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
509 		return false;
510 
511 	switch (family) {
512 	case NFPROTO_IPV4:
513 		if (!tcf_ct_flow_table_fill_tuple_ipv4(skb, &tuple, &tcph))
514 			return false;
515 		break;
516 	case NFPROTO_IPV6:
517 		if (!tcf_ct_flow_table_fill_tuple_ipv6(skb, &tuple, &tcph))
518 			return false;
519 		break;
520 	default:
521 		return false;
522 	}
523 
524 	tuplehash = flow_offload_lookup(nf_ft, &tuple);
525 	if (!tuplehash)
526 		return false;
527 
528 	dir = tuplehash->tuple.dir;
529 	flow = container_of(tuplehash, struct flow_offload, tuplehash[dir]);
530 	ct = flow->ct;
531 
532 	if (tcph && (unlikely(tcph->fin || tcph->rst))) {
533 		flow_offload_teardown(flow);
534 		return false;
535 	}
536 
537 	ctinfo = dir == FLOW_OFFLOAD_DIR_ORIGINAL ? IP_CT_ESTABLISHED :
538 						    IP_CT_ESTABLISHED_REPLY;
539 
540 	flow_offload_refresh(nf_ft, flow);
541 	nf_conntrack_get(&ct->ct_general);
542 	nf_ct_set(skb, ct, ctinfo);
543 	nf_ct_acct_update(ct, dir, skb->len);
544 
545 	return true;
546 }
547 
548 static int tcf_ct_flow_tables_init(void)
549 {
550 	return rhashtable_init(&zones_ht, &zones_params);
551 }
552 
553 static void tcf_ct_flow_tables_uninit(void)
554 {
555 	rhashtable_destroy(&zones_ht);
556 }
557 
558 static struct tc_action_ops act_ct_ops;
559 static unsigned int ct_net_id;
560 
561 struct tc_ct_action_net {
562 	struct tc_action_net tn; /* Must be first */
563 	bool labels;
564 };
565 
566 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
567 static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
568 				   u16 zone_id, bool force)
569 {
570 	enum ip_conntrack_info ctinfo;
571 	struct nf_conn *ct;
572 
573 	ct = nf_ct_get(skb, &ctinfo);
574 	if (!ct)
575 		return false;
576 	if (!net_eq(net, read_pnet(&ct->ct_net)))
577 		return false;
578 	if (nf_ct_zone(ct)->id != zone_id)
579 		return false;
580 
581 	/* Force conntrack entry direction. */
582 	if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
583 		if (nf_ct_is_confirmed(ct))
584 			nf_ct_kill(ct);
585 
586 		nf_conntrack_put(&ct->ct_general);
587 		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
588 
589 		return false;
590 	}
591 
592 	return true;
593 }
594 
595 /* Trim the skb to the length specified by the IP/IPv6 header,
596  * removing any trailing lower-layer padding. This prepares the skb
597  * for higher-layer processing that assumes skb->len excludes padding
598  * (such as nf_ip_checksum). The caller needs to pull the skb to the
599  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
600  */
601 static int tcf_ct_skb_network_trim(struct sk_buff *skb, int family)
602 {
603 	unsigned int len;
604 	int err;
605 
606 	switch (family) {
607 	case NFPROTO_IPV4:
608 		len = ntohs(ip_hdr(skb)->tot_len);
609 		break;
610 	case NFPROTO_IPV6:
611 		len = sizeof(struct ipv6hdr)
612 			+ ntohs(ipv6_hdr(skb)->payload_len);
613 		break;
614 	default:
615 		len = skb->len;
616 	}
617 
618 	err = pskb_trim_rcsum(skb, len);
619 
620 	return err;
621 }
622 
623 static u8 tcf_ct_skb_nf_family(struct sk_buff *skb)
624 {
625 	u8 family = NFPROTO_UNSPEC;
626 
627 	switch (skb_protocol(skb, true)) {
628 	case htons(ETH_P_IP):
629 		family = NFPROTO_IPV4;
630 		break;
631 	case htons(ETH_P_IPV6):
632 		family = NFPROTO_IPV6;
633 		break;
634 	default:
635 		break;
636 	}
637 
638 	return family;
639 }
640 
641 static int tcf_ct_ipv4_is_fragment(struct sk_buff *skb, bool *frag)
642 {
643 	unsigned int len;
644 
645 	len =  skb_network_offset(skb) + sizeof(struct iphdr);
646 	if (unlikely(skb->len < len))
647 		return -EINVAL;
648 	if (unlikely(!pskb_may_pull(skb, len)))
649 		return -ENOMEM;
650 
651 	*frag = ip_is_fragment(ip_hdr(skb));
652 	return 0;
653 }
654 
655 static int tcf_ct_ipv6_is_fragment(struct sk_buff *skb, bool *frag)
656 {
657 	unsigned int flags = 0, len, payload_ofs = 0;
658 	unsigned short frag_off;
659 	int nexthdr;
660 
661 	len =  skb_network_offset(skb) + sizeof(struct ipv6hdr);
662 	if (unlikely(skb->len < len))
663 		return -EINVAL;
664 	if (unlikely(!pskb_may_pull(skb, len)))
665 		return -ENOMEM;
666 
667 	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
668 	if (unlikely(nexthdr < 0))
669 		return -EPROTO;
670 
671 	*frag = flags & IP6_FH_F_FRAG;
672 	return 0;
673 }
674 
675 static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
676 				   u8 family, u16 zone, bool *defrag)
677 {
678 	enum ip_conntrack_info ctinfo;
679 	struct qdisc_skb_cb cb;
680 	struct nf_conn *ct;
681 	int err = 0;
682 	bool frag;
683 
684 	/* Previously seen (loopback)? Ignore. */
685 	ct = nf_ct_get(skb, &ctinfo);
686 	if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
687 		return 0;
688 
689 	if (family == NFPROTO_IPV4)
690 		err = tcf_ct_ipv4_is_fragment(skb, &frag);
691 	else
692 		err = tcf_ct_ipv6_is_fragment(skb, &frag);
693 	if (err || !frag)
694 		return err;
695 
696 	skb_get(skb);
697 	cb = *qdisc_skb_cb(skb);
698 
699 	if (family == NFPROTO_IPV4) {
700 		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
701 
702 		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
703 		local_bh_disable();
704 		err = ip_defrag(net, skb, user);
705 		local_bh_enable();
706 		if (err && err != -EINPROGRESS)
707 			return err;
708 
709 		if (!err) {
710 			*defrag = true;
711 			cb.mru = IPCB(skb)->frag_max_size;
712 		}
713 	} else { /* NFPROTO_IPV6 */
714 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
715 		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
716 
717 		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
718 		err = nf_ct_frag6_gather(net, skb, user);
719 		if (err && err != -EINPROGRESS)
720 			goto out_free;
721 
722 		if (!err) {
723 			*defrag = true;
724 			cb.mru = IP6CB(skb)->frag_max_size;
725 		}
726 #else
727 		err = -EOPNOTSUPP;
728 		goto out_free;
729 #endif
730 	}
731 
732 	*qdisc_skb_cb(skb) = cb;
733 	skb_clear_hash(skb);
734 	skb->ignore_df = 1;
735 	return err;
736 
737 out_free:
738 	kfree_skb(skb);
739 	return err;
740 }
741 
742 static void tcf_ct_params_free(struct rcu_head *head)
743 {
744 	struct tcf_ct_params *params = container_of(head,
745 						    struct tcf_ct_params, rcu);
746 
747 	tcf_ct_flow_table_put(params);
748 
749 	if (params->tmpl)
750 		nf_conntrack_put(&params->tmpl->ct_general);
751 	kfree(params);
752 }
753 
754 #if IS_ENABLED(CONFIG_NF_NAT)
755 /* Modelled after nf_nat_ipv[46]_fn().
756  * range is only used for new, uninitialized NAT state.
757  * Returns either NF_ACCEPT or NF_DROP.
758  */
759 static int ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
760 			  enum ip_conntrack_info ctinfo,
761 			  const struct nf_nat_range2 *range,
762 			  enum nf_nat_manip_type maniptype)
763 {
764 	__be16 proto = skb_protocol(skb, true);
765 	int hooknum, err = NF_ACCEPT;
766 
767 	/* See HOOK2MANIP(). */
768 	if (maniptype == NF_NAT_MANIP_SRC)
769 		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
770 	else
771 		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
772 
773 	switch (ctinfo) {
774 	case IP_CT_RELATED:
775 	case IP_CT_RELATED_REPLY:
776 		if (proto == htons(ETH_P_IP) &&
777 		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
778 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
779 							   hooknum))
780 				err = NF_DROP;
781 			goto out;
782 		} else if (IS_ENABLED(CONFIG_IPV6) && proto == htons(ETH_P_IPV6)) {
783 			__be16 frag_off;
784 			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
785 			int hdrlen = ipv6_skip_exthdr(skb,
786 						      sizeof(struct ipv6hdr),
787 						      &nexthdr, &frag_off);
788 
789 			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
790 				if (!nf_nat_icmpv6_reply_translation(skb, ct,
791 								     ctinfo,
792 								     hooknum,
793 								     hdrlen))
794 					err = NF_DROP;
795 				goto out;
796 			}
797 		}
798 		/* Non-ICMP, fall thru to initialize if needed. */
799 		fallthrough;
800 	case IP_CT_NEW:
801 		/* Seen it before?  This can happen for loopback, retrans,
802 		 * or local packets.
803 		 */
804 		if (!nf_nat_initialized(ct, maniptype)) {
805 			/* Initialize according to the NAT action. */
806 			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
807 				/* Action is set up to establish a new
808 				 * mapping.
809 				 */
810 				? nf_nat_setup_info(ct, range, maniptype)
811 				: nf_nat_alloc_null_binding(ct, hooknum);
812 			if (err != NF_ACCEPT)
813 				goto out;
814 		}
815 		break;
816 
817 	case IP_CT_ESTABLISHED:
818 	case IP_CT_ESTABLISHED_REPLY:
819 		break;
820 
821 	default:
822 		err = NF_DROP;
823 		goto out;
824 	}
825 
826 	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
827 out:
828 	return err;
829 }
830 #endif /* CONFIG_NF_NAT */
831 
832 static void tcf_ct_act_set_mark(struct nf_conn *ct, u32 mark, u32 mask)
833 {
834 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
835 	u32 new_mark;
836 
837 	if (!mask)
838 		return;
839 
840 	new_mark = mark | (ct->mark & ~(mask));
841 	if (ct->mark != new_mark) {
842 		ct->mark = new_mark;
843 		if (nf_ct_is_confirmed(ct))
844 			nf_conntrack_event_cache(IPCT_MARK, ct);
845 	}
846 #endif
847 }
848 
849 static void tcf_ct_act_set_labels(struct nf_conn *ct,
850 				  u32 *labels,
851 				  u32 *labels_m)
852 {
853 #if IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)
854 	size_t labels_sz = sizeof_field(struct tcf_ct_params, labels);
855 
856 	if (!memchr_inv(labels_m, 0, labels_sz))
857 		return;
858 
859 	nf_connlabels_replace(ct, labels, labels_m, 4);
860 #endif
861 }
862 
863 static int tcf_ct_act_nat(struct sk_buff *skb,
864 			  struct nf_conn *ct,
865 			  enum ip_conntrack_info ctinfo,
866 			  int ct_action,
867 			  struct nf_nat_range2 *range,
868 			  bool commit)
869 {
870 #if IS_ENABLED(CONFIG_NF_NAT)
871 	int err;
872 	enum nf_nat_manip_type maniptype;
873 
874 	if (!(ct_action & TCA_CT_ACT_NAT))
875 		return NF_ACCEPT;
876 
877 	/* Add NAT extension if not confirmed yet. */
878 	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
879 		return NF_DROP;   /* Can't NAT. */
880 
881 	if (ctinfo != IP_CT_NEW && (ct->status & IPS_NAT_MASK) &&
882 	    (ctinfo != IP_CT_RELATED || commit)) {
883 		/* NAT an established or related connection like before. */
884 		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
885 			/* This is the REPLY direction for a connection
886 			 * for which NAT was applied in the forward
887 			 * direction.  Do the reverse NAT.
888 			 */
889 			maniptype = ct->status & IPS_SRC_NAT
890 				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
891 		else
892 			maniptype = ct->status & IPS_SRC_NAT
893 				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
894 	} else if (ct_action & TCA_CT_ACT_NAT_SRC) {
895 		maniptype = NF_NAT_MANIP_SRC;
896 	} else if (ct_action & TCA_CT_ACT_NAT_DST) {
897 		maniptype = NF_NAT_MANIP_DST;
898 	} else {
899 		return NF_ACCEPT;
900 	}
901 
902 	err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
903 	if (err == NF_ACCEPT &&
904 	    ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
905 		if (maniptype == NF_NAT_MANIP_SRC)
906 			maniptype = NF_NAT_MANIP_DST;
907 		else
908 			maniptype = NF_NAT_MANIP_SRC;
909 
910 		err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
911 	}
912 	return err;
913 #else
914 	return NF_ACCEPT;
915 #endif
916 }
917 
918 static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
919 		      struct tcf_result *res)
920 {
921 	struct net *net = dev_net(skb->dev);
922 	bool cached, commit, clear, force;
923 	enum ip_conntrack_info ctinfo;
924 	struct tcf_ct *c = to_ct(a);
925 	struct nf_conn *tmpl = NULL;
926 	struct nf_hook_state state;
927 	int nh_ofs, err, retval;
928 	struct tcf_ct_params *p;
929 	bool skip_add = false;
930 	bool defrag = false;
931 	struct nf_conn *ct;
932 	u8 family;
933 
934 	p = rcu_dereference_bh(c->params);
935 
936 	retval = READ_ONCE(c->tcf_action);
937 	commit = p->ct_action & TCA_CT_ACT_COMMIT;
938 	clear = p->ct_action & TCA_CT_ACT_CLEAR;
939 	force = p->ct_action & TCA_CT_ACT_FORCE;
940 	tmpl = p->tmpl;
941 
942 	tcf_lastuse_update(&c->tcf_tm);
943 
944 	if (clear) {
945 		ct = nf_ct_get(skb, &ctinfo);
946 		if (ct) {
947 			nf_conntrack_put(&ct->ct_general);
948 			nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
949 		}
950 
951 		goto out;
952 	}
953 
954 	family = tcf_ct_skb_nf_family(skb);
955 	if (family == NFPROTO_UNSPEC)
956 		goto drop;
957 
958 	/* The conntrack module expects to be working at L3.
959 	 * We also try to pull the IPv4/6 header to linear area
960 	 */
961 	nh_ofs = skb_network_offset(skb);
962 	skb_pull_rcsum(skb, nh_ofs);
963 	err = tcf_ct_handle_fragments(net, skb, family, p->zone, &defrag);
964 	if (err == -EINPROGRESS) {
965 		retval = TC_ACT_STOLEN;
966 		goto out;
967 	}
968 	if (err)
969 		goto drop;
970 
971 	err = tcf_ct_skb_network_trim(skb, family);
972 	if (err)
973 		goto drop;
974 
975 	/* If we are recirculating packets to match on ct fields and
976 	 * committing with a separate ct action, then we don't need to
977 	 * actually run the packet through conntrack twice unless it's for a
978 	 * different zone.
979 	 */
980 	cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force);
981 	if (!cached) {
982 		if (!commit && tcf_ct_flow_table_lookup(p, skb, family)) {
983 			skip_add = true;
984 			goto do_nat;
985 		}
986 
987 		/* Associate skb with specified zone. */
988 		if (tmpl) {
989 			ct = nf_ct_get(skb, &ctinfo);
990 			if (skb_nfct(skb))
991 				nf_conntrack_put(skb_nfct(skb));
992 			nf_conntrack_get(&tmpl->ct_general);
993 			nf_ct_set(skb, tmpl, IP_CT_NEW);
994 		}
995 
996 		state.hook = NF_INET_PRE_ROUTING;
997 		state.net = net;
998 		state.pf = family;
999 		err = nf_conntrack_in(skb, &state);
1000 		if (err != NF_ACCEPT)
1001 			goto out_push;
1002 	}
1003 
1004 do_nat:
1005 	ct = nf_ct_get(skb, &ctinfo);
1006 	if (!ct)
1007 		goto out_push;
1008 	nf_ct_deliver_cached_events(ct);
1009 
1010 	err = tcf_ct_act_nat(skb, ct, ctinfo, p->ct_action, &p->range, commit);
1011 	if (err != NF_ACCEPT)
1012 		goto drop;
1013 
1014 	if (commit) {
1015 		tcf_ct_act_set_mark(ct, p->mark, p->mark_mask);
1016 		tcf_ct_act_set_labels(ct, p->labels, p->labels_mask);
1017 
1018 		/* This will take care of sending queued events
1019 		 * even if the connection is already confirmed.
1020 		 */
1021 		nf_conntrack_confirm(skb);
1022 	} else if (!skip_add) {
1023 		tcf_ct_flow_table_process_conn(p->ct_ft, ct, ctinfo);
1024 	}
1025 
1026 out_push:
1027 	skb_push_rcsum(skb, nh_ofs);
1028 
1029 out:
1030 	tcf_action_update_bstats(&c->common, skb);
1031 	if (defrag)
1032 		qdisc_skb_cb(skb)->pkt_len = skb->len;
1033 	return retval;
1034 
1035 drop:
1036 	tcf_action_inc_drop_qstats(&c->common);
1037 	return TC_ACT_SHOT;
1038 }
1039 
1040 static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
1041 	[TCA_CT_ACTION] = { .type = NLA_U16 },
1042 	[TCA_CT_PARMS] = { .type = NLA_EXACT_LEN, .len = sizeof(struct tc_ct) },
1043 	[TCA_CT_ZONE] = { .type = NLA_U16 },
1044 	[TCA_CT_MARK] = { .type = NLA_U32 },
1045 	[TCA_CT_MARK_MASK] = { .type = NLA_U32 },
1046 	[TCA_CT_LABELS] = { .type = NLA_BINARY,
1047 			    .len = 128 / BITS_PER_BYTE },
1048 	[TCA_CT_LABELS_MASK] = { .type = NLA_BINARY,
1049 				 .len = 128 / BITS_PER_BYTE },
1050 	[TCA_CT_NAT_IPV4_MIN] = { .type = NLA_U32 },
1051 	[TCA_CT_NAT_IPV4_MAX] = { .type = NLA_U32 },
1052 	[TCA_CT_NAT_IPV6_MIN] = { .type = NLA_EXACT_LEN,
1053 				  .len = sizeof(struct in6_addr) },
1054 	[TCA_CT_NAT_IPV6_MAX] = { .type = NLA_EXACT_LEN,
1055 				   .len = sizeof(struct in6_addr) },
1056 	[TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 },
1057 	[TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 },
1058 };
1059 
1060 static int tcf_ct_fill_params_nat(struct tcf_ct_params *p,
1061 				  struct tc_ct *parm,
1062 				  struct nlattr **tb,
1063 				  struct netlink_ext_ack *extack)
1064 {
1065 	struct nf_nat_range2 *range;
1066 
1067 	if (!(p->ct_action & TCA_CT_ACT_NAT))
1068 		return 0;
1069 
1070 	if (!IS_ENABLED(CONFIG_NF_NAT)) {
1071 		NL_SET_ERR_MSG_MOD(extack, "Netfilter nat isn't enabled in kernel");
1072 		return -EOPNOTSUPP;
1073 	}
1074 
1075 	if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
1076 		return 0;
1077 
1078 	if ((p->ct_action & TCA_CT_ACT_NAT_SRC) &&
1079 	    (p->ct_action & TCA_CT_ACT_NAT_DST)) {
1080 		NL_SET_ERR_MSG_MOD(extack, "dnat and snat can't be enabled at the same time");
1081 		return -EOPNOTSUPP;
1082 	}
1083 
1084 	range = &p->range;
1085 	if (tb[TCA_CT_NAT_IPV4_MIN]) {
1086 		struct nlattr *max_attr = tb[TCA_CT_NAT_IPV4_MAX];
1087 
1088 		p->ipv4_range = true;
1089 		range->flags |= NF_NAT_RANGE_MAP_IPS;
1090 		range->min_addr.ip =
1091 			nla_get_in_addr(tb[TCA_CT_NAT_IPV4_MIN]);
1092 
1093 		range->max_addr.ip = max_attr ?
1094 				     nla_get_in_addr(max_attr) :
1095 				     range->min_addr.ip;
1096 	} else if (tb[TCA_CT_NAT_IPV6_MIN]) {
1097 		struct nlattr *max_attr = tb[TCA_CT_NAT_IPV6_MAX];
1098 
1099 		p->ipv4_range = false;
1100 		range->flags |= NF_NAT_RANGE_MAP_IPS;
1101 		range->min_addr.in6 =
1102 			nla_get_in6_addr(tb[TCA_CT_NAT_IPV6_MIN]);
1103 
1104 		range->max_addr.in6 = max_attr ?
1105 				      nla_get_in6_addr(max_attr) :
1106 				      range->min_addr.in6;
1107 	}
1108 
1109 	if (tb[TCA_CT_NAT_PORT_MIN]) {
1110 		range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
1111 		range->min_proto.all = nla_get_be16(tb[TCA_CT_NAT_PORT_MIN]);
1112 
1113 		range->max_proto.all = tb[TCA_CT_NAT_PORT_MAX] ?
1114 				       nla_get_be16(tb[TCA_CT_NAT_PORT_MAX]) :
1115 				       range->min_proto.all;
1116 	}
1117 
1118 	return 0;
1119 }
1120 
1121 static void tcf_ct_set_key_val(struct nlattr **tb,
1122 			       void *val, int val_type,
1123 			       void *mask, int mask_type,
1124 			       int len)
1125 {
1126 	if (!tb[val_type])
1127 		return;
1128 	nla_memcpy(val, tb[val_type], len);
1129 
1130 	if (!mask)
1131 		return;
1132 
1133 	if (mask_type == TCA_CT_UNSPEC || !tb[mask_type])
1134 		memset(mask, 0xff, len);
1135 	else
1136 		nla_memcpy(mask, tb[mask_type], len);
1137 }
1138 
1139 static int tcf_ct_fill_params(struct net *net,
1140 			      struct tcf_ct_params *p,
1141 			      struct tc_ct *parm,
1142 			      struct nlattr **tb,
1143 			      struct netlink_ext_ack *extack)
1144 {
1145 	struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
1146 	struct nf_conntrack_zone zone;
1147 	struct nf_conn *tmpl;
1148 	int err;
1149 
1150 	p->zone = NF_CT_DEFAULT_ZONE_ID;
1151 
1152 	tcf_ct_set_key_val(tb,
1153 			   &p->ct_action, TCA_CT_ACTION,
1154 			   NULL, TCA_CT_UNSPEC,
1155 			   sizeof(p->ct_action));
1156 
1157 	if (p->ct_action & TCA_CT_ACT_CLEAR)
1158 		return 0;
1159 
1160 	err = tcf_ct_fill_params_nat(p, parm, tb, extack);
1161 	if (err)
1162 		return err;
1163 
1164 	if (tb[TCA_CT_MARK]) {
1165 		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)) {
1166 			NL_SET_ERR_MSG_MOD(extack, "Conntrack mark isn't enabled.");
1167 			return -EOPNOTSUPP;
1168 		}
1169 		tcf_ct_set_key_val(tb,
1170 				   &p->mark, TCA_CT_MARK,
1171 				   &p->mark_mask, TCA_CT_MARK_MASK,
1172 				   sizeof(p->mark));
1173 	}
1174 
1175 	if (tb[TCA_CT_LABELS]) {
1176 		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)) {
1177 			NL_SET_ERR_MSG_MOD(extack, "Conntrack labels isn't enabled.");
1178 			return -EOPNOTSUPP;
1179 		}
1180 
1181 		if (!tn->labels) {
1182 			NL_SET_ERR_MSG_MOD(extack, "Failed to set connlabel length");
1183 			return -EOPNOTSUPP;
1184 		}
1185 		tcf_ct_set_key_val(tb,
1186 				   p->labels, TCA_CT_LABELS,
1187 				   p->labels_mask, TCA_CT_LABELS_MASK,
1188 				   sizeof(p->labels));
1189 	}
1190 
1191 	if (tb[TCA_CT_ZONE]) {
1192 		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)) {
1193 			NL_SET_ERR_MSG_MOD(extack, "Conntrack zones isn't enabled.");
1194 			return -EOPNOTSUPP;
1195 		}
1196 
1197 		tcf_ct_set_key_val(tb,
1198 				   &p->zone, TCA_CT_ZONE,
1199 				   NULL, TCA_CT_UNSPEC,
1200 				   sizeof(p->zone));
1201 	}
1202 
1203 	if (p->zone == NF_CT_DEFAULT_ZONE_ID)
1204 		return 0;
1205 
1206 	nf_ct_zone_init(&zone, p->zone, NF_CT_DEFAULT_ZONE_DIR, 0);
1207 	tmpl = nf_ct_tmpl_alloc(net, &zone, GFP_KERNEL);
1208 	if (!tmpl) {
1209 		NL_SET_ERR_MSG_MOD(extack, "Failed to allocate conntrack template");
1210 		return -ENOMEM;
1211 	}
1212 	__set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
1213 	nf_conntrack_get(&tmpl->ct_general);
1214 	p->tmpl = tmpl;
1215 
1216 	return 0;
1217 }
1218 
1219 static int tcf_ct_init(struct net *net, struct nlattr *nla,
1220 		       struct nlattr *est, struct tc_action **a,
1221 		       int replace, int bind, bool rtnl_held,
1222 		       struct tcf_proto *tp, u32 flags,
1223 		       struct netlink_ext_ack *extack)
1224 {
1225 	struct tc_action_net *tn = net_generic(net, ct_net_id);
1226 	struct tcf_ct_params *params = NULL;
1227 	struct nlattr *tb[TCA_CT_MAX + 1];
1228 	struct tcf_chain *goto_ch = NULL;
1229 	struct tc_ct *parm;
1230 	struct tcf_ct *c;
1231 	int err, res = 0;
1232 	u32 index;
1233 
1234 	if (!nla) {
1235 		NL_SET_ERR_MSG_MOD(extack, "Ct requires attributes to be passed");
1236 		return -EINVAL;
1237 	}
1238 
1239 	err = nla_parse_nested(tb, TCA_CT_MAX, nla, ct_policy, extack);
1240 	if (err < 0)
1241 		return err;
1242 
1243 	if (!tb[TCA_CT_PARMS]) {
1244 		NL_SET_ERR_MSG_MOD(extack, "Missing required ct parameters");
1245 		return -EINVAL;
1246 	}
1247 	parm = nla_data(tb[TCA_CT_PARMS]);
1248 	index = parm->index;
1249 	err = tcf_idr_check_alloc(tn, &index, a, bind);
1250 	if (err < 0)
1251 		return err;
1252 
1253 	if (!err) {
1254 		err = tcf_idr_create_from_flags(tn, index, est, a,
1255 						&act_ct_ops, bind, flags);
1256 		if (err) {
1257 			tcf_idr_cleanup(tn, index);
1258 			return err;
1259 		}
1260 		res = ACT_P_CREATED;
1261 	} else {
1262 		if (bind)
1263 			return 0;
1264 
1265 		if (!replace) {
1266 			tcf_idr_release(*a, bind);
1267 			return -EEXIST;
1268 		}
1269 	}
1270 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
1271 	if (err < 0)
1272 		goto cleanup;
1273 
1274 	c = to_ct(*a);
1275 
1276 	params = kzalloc(sizeof(*params), GFP_KERNEL);
1277 	if (unlikely(!params)) {
1278 		err = -ENOMEM;
1279 		goto cleanup;
1280 	}
1281 
1282 	err = tcf_ct_fill_params(net, params, parm, tb, extack);
1283 	if (err)
1284 		goto cleanup;
1285 
1286 	err = tcf_ct_flow_table_get(params);
1287 	if (err)
1288 		goto cleanup;
1289 
1290 	spin_lock_bh(&c->tcf_lock);
1291 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
1292 	params = rcu_replace_pointer(c->params, params,
1293 				     lockdep_is_held(&c->tcf_lock));
1294 	spin_unlock_bh(&c->tcf_lock);
1295 
1296 	if (goto_ch)
1297 		tcf_chain_put_by_act(goto_ch);
1298 	if (params)
1299 		call_rcu(&params->rcu, tcf_ct_params_free);
1300 	if (res == ACT_P_CREATED)
1301 		tcf_idr_insert(tn, *a);
1302 
1303 	return res;
1304 
1305 cleanup:
1306 	if (goto_ch)
1307 		tcf_chain_put_by_act(goto_ch);
1308 	kfree(params);
1309 	tcf_idr_release(*a, bind);
1310 	return err;
1311 }
1312 
1313 static void tcf_ct_cleanup(struct tc_action *a)
1314 {
1315 	struct tcf_ct_params *params;
1316 	struct tcf_ct *c = to_ct(a);
1317 
1318 	params = rcu_dereference_protected(c->params, 1);
1319 	if (params)
1320 		call_rcu(&params->rcu, tcf_ct_params_free);
1321 }
1322 
1323 static int tcf_ct_dump_key_val(struct sk_buff *skb,
1324 			       void *val, int val_type,
1325 			       void *mask, int mask_type,
1326 			       int len)
1327 {
1328 	int err;
1329 
1330 	if (mask && !memchr_inv(mask, 0, len))
1331 		return 0;
1332 
1333 	err = nla_put(skb, val_type, len, val);
1334 	if (err)
1335 		return err;
1336 
1337 	if (mask_type != TCA_CT_UNSPEC) {
1338 		err = nla_put(skb, mask_type, len, mask);
1339 		if (err)
1340 			return err;
1341 	}
1342 
1343 	return 0;
1344 }
1345 
1346 static int tcf_ct_dump_nat(struct sk_buff *skb, struct tcf_ct_params *p)
1347 {
1348 	struct nf_nat_range2 *range = &p->range;
1349 
1350 	if (!(p->ct_action & TCA_CT_ACT_NAT))
1351 		return 0;
1352 
1353 	if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
1354 		return 0;
1355 
1356 	if (range->flags & NF_NAT_RANGE_MAP_IPS) {
1357 		if (p->ipv4_range) {
1358 			if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MIN,
1359 					    range->min_addr.ip))
1360 				return -1;
1361 			if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MAX,
1362 					    range->max_addr.ip))
1363 				return -1;
1364 		} else {
1365 			if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MIN,
1366 					     &range->min_addr.in6))
1367 				return -1;
1368 			if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MAX,
1369 					     &range->max_addr.in6))
1370 				return -1;
1371 		}
1372 	}
1373 
1374 	if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
1375 		if (nla_put_be16(skb, TCA_CT_NAT_PORT_MIN,
1376 				 range->min_proto.all))
1377 			return -1;
1378 		if (nla_put_be16(skb, TCA_CT_NAT_PORT_MAX,
1379 				 range->max_proto.all))
1380 			return -1;
1381 	}
1382 
1383 	return 0;
1384 }
1385 
1386 static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a,
1387 			      int bind, int ref)
1388 {
1389 	unsigned char *b = skb_tail_pointer(skb);
1390 	struct tcf_ct *c = to_ct(a);
1391 	struct tcf_ct_params *p;
1392 
1393 	struct tc_ct opt = {
1394 		.index   = c->tcf_index,
1395 		.refcnt  = refcount_read(&c->tcf_refcnt) - ref,
1396 		.bindcnt = atomic_read(&c->tcf_bindcnt) - bind,
1397 	};
1398 	struct tcf_t t;
1399 
1400 	spin_lock_bh(&c->tcf_lock);
1401 	p = rcu_dereference_protected(c->params,
1402 				      lockdep_is_held(&c->tcf_lock));
1403 	opt.action = c->tcf_action;
1404 
1405 	if (tcf_ct_dump_key_val(skb,
1406 				&p->ct_action, TCA_CT_ACTION,
1407 				NULL, TCA_CT_UNSPEC,
1408 				sizeof(p->ct_action)))
1409 		goto nla_put_failure;
1410 
1411 	if (p->ct_action & TCA_CT_ACT_CLEAR)
1412 		goto skip_dump;
1413 
1414 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
1415 	    tcf_ct_dump_key_val(skb,
1416 				&p->mark, TCA_CT_MARK,
1417 				&p->mark_mask, TCA_CT_MARK_MASK,
1418 				sizeof(p->mark)))
1419 		goto nla_put_failure;
1420 
1421 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
1422 	    tcf_ct_dump_key_val(skb,
1423 				p->labels, TCA_CT_LABELS,
1424 				p->labels_mask, TCA_CT_LABELS_MASK,
1425 				sizeof(p->labels)))
1426 		goto nla_put_failure;
1427 
1428 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
1429 	    tcf_ct_dump_key_val(skb,
1430 				&p->zone, TCA_CT_ZONE,
1431 				NULL, TCA_CT_UNSPEC,
1432 				sizeof(p->zone)))
1433 		goto nla_put_failure;
1434 
1435 	if (tcf_ct_dump_nat(skb, p))
1436 		goto nla_put_failure;
1437 
1438 skip_dump:
1439 	if (nla_put(skb, TCA_CT_PARMS, sizeof(opt), &opt))
1440 		goto nla_put_failure;
1441 
1442 	tcf_tm_dump(&t, &c->tcf_tm);
1443 	if (nla_put_64bit(skb, TCA_CT_TM, sizeof(t), &t, TCA_CT_PAD))
1444 		goto nla_put_failure;
1445 	spin_unlock_bh(&c->tcf_lock);
1446 
1447 	return skb->len;
1448 nla_put_failure:
1449 	spin_unlock_bh(&c->tcf_lock);
1450 	nlmsg_trim(skb, b);
1451 	return -1;
1452 }
1453 
1454 static int tcf_ct_walker(struct net *net, struct sk_buff *skb,
1455 			 struct netlink_callback *cb, int type,
1456 			 const struct tc_action_ops *ops,
1457 			 struct netlink_ext_ack *extack)
1458 {
1459 	struct tc_action_net *tn = net_generic(net, ct_net_id);
1460 
1461 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
1462 }
1463 
1464 static int tcf_ct_search(struct net *net, struct tc_action **a, u32 index)
1465 {
1466 	struct tc_action_net *tn = net_generic(net, ct_net_id);
1467 
1468 	return tcf_idr_search(tn, a, index);
1469 }
1470 
1471 static void tcf_stats_update(struct tc_action *a, u64 bytes, u64 packets,
1472 			     u64 drops, u64 lastuse, bool hw)
1473 {
1474 	struct tcf_ct *c = to_ct(a);
1475 
1476 	tcf_action_update_stats(a, bytes, packets, drops, hw);
1477 	c->tcf_tm.lastuse = max_t(u64, c->tcf_tm.lastuse, lastuse);
1478 }
1479 
1480 static struct tc_action_ops act_ct_ops = {
1481 	.kind		=	"ct",
1482 	.id		=	TCA_ID_CT,
1483 	.owner		=	THIS_MODULE,
1484 	.act		=	tcf_ct_act,
1485 	.dump		=	tcf_ct_dump,
1486 	.init		=	tcf_ct_init,
1487 	.cleanup	=	tcf_ct_cleanup,
1488 	.walk		=	tcf_ct_walker,
1489 	.lookup		=	tcf_ct_search,
1490 	.stats_update	=	tcf_stats_update,
1491 	.size		=	sizeof(struct tcf_ct),
1492 };
1493 
1494 static __net_init int ct_init_net(struct net *net)
1495 {
1496 	unsigned int n_bits = sizeof_field(struct tcf_ct_params, labels) * 8;
1497 	struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
1498 
1499 	if (nf_connlabels_get(net, n_bits - 1)) {
1500 		tn->labels = false;
1501 		pr_err("act_ct: Failed to set connlabels length");
1502 	} else {
1503 		tn->labels = true;
1504 	}
1505 
1506 	return tc_action_net_init(net, &tn->tn, &act_ct_ops);
1507 }
1508 
1509 static void __net_exit ct_exit_net(struct list_head *net_list)
1510 {
1511 	struct net *net;
1512 
1513 	rtnl_lock();
1514 	list_for_each_entry(net, net_list, exit_list) {
1515 		struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
1516 
1517 		if (tn->labels)
1518 			nf_connlabels_put(net);
1519 	}
1520 	rtnl_unlock();
1521 
1522 	tc_action_net_exit(net_list, ct_net_id);
1523 }
1524 
1525 static struct pernet_operations ct_net_ops = {
1526 	.init = ct_init_net,
1527 	.exit_batch = ct_exit_net,
1528 	.id   = &ct_net_id,
1529 	.size = sizeof(struct tc_ct_action_net),
1530 };
1531 
1532 static int __init ct_init_module(void)
1533 {
1534 	int err;
1535 
1536 	act_ct_wq = alloc_ordered_workqueue("act_ct_workqueue", 0);
1537 	if (!act_ct_wq)
1538 		return -ENOMEM;
1539 
1540 	err = tcf_ct_flow_tables_init();
1541 	if (err)
1542 		goto err_tbl_init;
1543 
1544 	err = tcf_register_action(&act_ct_ops, &ct_net_ops);
1545 	if (err)
1546 		goto err_register;
1547 
1548 	return 0;
1549 
1550 err_register:
1551 	tcf_ct_flow_tables_uninit();
1552 err_tbl_init:
1553 	destroy_workqueue(act_ct_wq);
1554 	return err;
1555 }
1556 
1557 static void __exit ct_cleanup_module(void)
1558 {
1559 	tcf_unregister_action(&act_ct_ops, &ct_net_ops);
1560 	tcf_ct_flow_tables_uninit();
1561 	destroy_workqueue(act_ct_wq);
1562 }
1563 
1564 module_init(ct_init_module);
1565 module_exit(ct_cleanup_module);
1566 MODULE_AUTHOR("Paul Blakey <paulb@mellanox.com>");
1567 MODULE_AUTHOR("Yossi Kuperman <yossiku@mellanox.com>");
1568 MODULE_AUTHOR("Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>");
1569 MODULE_DESCRIPTION("Connection tracking action");
1570 MODULE_LICENSE("GPL v2");
1571