xref: /linux/net/sched/act_ct.c (revision f8e17c17b81070f38062dce79ca7f4541851dadd)
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 <net/netlink.h>
19 #include <net/pkt_sched.h>
20 #include <net/pkt_cls.h>
21 #include <net/act_api.h>
22 #include <net/ip.h>
23 #include <net/ipv6_frag.h>
24 #include <uapi/linux/tc_act/tc_ct.h>
25 #include <net/tc_act/tc_ct.h>
26 
27 #include <net/netfilter/nf_conntrack.h>
28 #include <net/netfilter/nf_conntrack_core.h>
29 #include <net/netfilter/nf_conntrack_zones.h>
30 #include <net/netfilter/nf_conntrack_helper.h>
31 #include <net/netfilter/ipv6/nf_defrag_ipv6.h>
32 #include <uapi/linux/netfilter/nf_nat.h>
33 
34 static struct tc_action_ops act_ct_ops;
35 static unsigned int ct_net_id;
36 
37 struct tc_ct_action_net {
38 	struct tc_action_net tn; /* Must be first */
39 	bool labels;
40 };
41 
42 /* Determine whether skb->_nfct is equal to the result of conntrack lookup. */
43 static bool tcf_ct_skb_nfct_cached(struct net *net, struct sk_buff *skb,
44 				   u16 zone_id, bool force)
45 {
46 	enum ip_conntrack_info ctinfo;
47 	struct nf_conn *ct;
48 
49 	ct = nf_ct_get(skb, &ctinfo);
50 	if (!ct)
51 		return false;
52 	if (!net_eq(net, read_pnet(&ct->ct_net)))
53 		return false;
54 	if (nf_ct_zone(ct)->id != zone_id)
55 		return false;
56 
57 	/* Force conntrack entry direction. */
58 	if (force && CTINFO2DIR(ctinfo) != IP_CT_DIR_ORIGINAL) {
59 		if (nf_ct_is_confirmed(ct))
60 			nf_ct_kill(ct);
61 
62 		nf_conntrack_put(&ct->ct_general);
63 		nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
64 
65 		return false;
66 	}
67 
68 	return true;
69 }
70 
71 /* Trim the skb to the length specified by the IP/IPv6 header,
72  * removing any trailing lower-layer padding. This prepares the skb
73  * for higher-layer processing that assumes skb->len excludes padding
74  * (such as nf_ip_checksum). The caller needs to pull the skb to the
75  * network header, and ensure ip_hdr/ipv6_hdr points to valid data.
76  */
77 static int tcf_ct_skb_network_trim(struct sk_buff *skb, int family)
78 {
79 	unsigned int len;
80 	int err;
81 
82 	switch (family) {
83 	case NFPROTO_IPV4:
84 		len = ntohs(ip_hdr(skb)->tot_len);
85 		break;
86 	case NFPROTO_IPV6:
87 		len = sizeof(struct ipv6hdr)
88 			+ ntohs(ipv6_hdr(skb)->payload_len);
89 		break;
90 	default:
91 		len = skb->len;
92 	}
93 
94 	err = pskb_trim_rcsum(skb, len);
95 
96 	return err;
97 }
98 
99 static u8 tcf_ct_skb_nf_family(struct sk_buff *skb)
100 {
101 	u8 family = NFPROTO_UNSPEC;
102 
103 	switch (skb->protocol) {
104 	case htons(ETH_P_IP):
105 		family = NFPROTO_IPV4;
106 		break;
107 	case htons(ETH_P_IPV6):
108 		family = NFPROTO_IPV6;
109 		break;
110 	default:
111 		break;
112 	}
113 
114 	return family;
115 }
116 
117 static int tcf_ct_ipv4_is_fragment(struct sk_buff *skb, bool *frag)
118 {
119 	unsigned int len;
120 
121 	len =  skb_network_offset(skb) + sizeof(struct iphdr);
122 	if (unlikely(skb->len < len))
123 		return -EINVAL;
124 	if (unlikely(!pskb_may_pull(skb, len)))
125 		return -ENOMEM;
126 
127 	*frag = ip_is_fragment(ip_hdr(skb));
128 	return 0;
129 }
130 
131 static int tcf_ct_ipv6_is_fragment(struct sk_buff *skb, bool *frag)
132 {
133 	unsigned int flags = 0, len, payload_ofs = 0;
134 	unsigned short frag_off;
135 	int nexthdr;
136 
137 	len =  skb_network_offset(skb) + sizeof(struct ipv6hdr);
138 	if (unlikely(skb->len < len))
139 		return -EINVAL;
140 	if (unlikely(!pskb_may_pull(skb, len)))
141 		return -ENOMEM;
142 
143 	nexthdr = ipv6_find_hdr(skb, &payload_ofs, -1, &frag_off, &flags);
144 	if (unlikely(nexthdr < 0))
145 		return -EPROTO;
146 
147 	*frag = flags & IP6_FH_F_FRAG;
148 	return 0;
149 }
150 
151 static int tcf_ct_handle_fragments(struct net *net, struct sk_buff *skb,
152 				   u8 family, u16 zone)
153 {
154 	enum ip_conntrack_info ctinfo;
155 	struct nf_conn *ct;
156 	int err = 0;
157 	bool frag;
158 
159 	/* Previously seen (loopback)? Ignore. */
160 	ct = nf_ct_get(skb, &ctinfo);
161 	if ((ct && !nf_ct_is_template(ct)) || ctinfo == IP_CT_UNTRACKED)
162 		return 0;
163 
164 	if (family == NFPROTO_IPV4)
165 		err = tcf_ct_ipv4_is_fragment(skb, &frag);
166 	else
167 		err = tcf_ct_ipv6_is_fragment(skb, &frag);
168 	if (err || !frag)
169 		return err;
170 
171 	skb_get(skb);
172 
173 	if (family == NFPROTO_IPV4) {
174 		enum ip_defrag_users user = IP_DEFRAG_CONNTRACK_IN + zone;
175 
176 		memset(IPCB(skb), 0, sizeof(struct inet_skb_parm));
177 		local_bh_disable();
178 		err = ip_defrag(net, skb, user);
179 		local_bh_enable();
180 		if (err && err != -EINPROGRESS)
181 			goto out_free;
182 	} else { /* NFPROTO_IPV6 */
183 #if IS_ENABLED(CONFIG_NF_DEFRAG_IPV6)
184 		enum ip6_defrag_users user = IP6_DEFRAG_CONNTRACK_IN + zone;
185 
186 		memset(IP6CB(skb), 0, sizeof(struct inet6_skb_parm));
187 		err = nf_ct_frag6_gather(net, skb, user);
188 		if (err && err != -EINPROGRESS)
189 			goto out_free;
190 #else
191 		err = -EOPNOTSUPP;
192 		goto out_free;
193 #endif
194 	}
195 
196 	skb_clear_hash(skb);
197 	skb->ignore_df = 1;
198 	return err;
199 
200 out_free:
201 	kfree_skb(skb);
202 	return err;
203 }
204 
205 static void tcf_ct_params_free(struct rcu_head *head)
206 {
207 	struct tcf_ct_params *params = container_of(head,
208 						    struct tcf_ct_params, rcu);
209 
210 	if (params->tmpl)
211 		nf_conntrack_put(&params->tmpl->ct_general);
212 	kfree(params);
213 }
214 
215 #if IS_ENABLED(CONFIG_NF_NAT)
216 /* Modelled after nf_nat_ipv[46]_fn().
217  * range is only used for new, uninitialized NAT state.
218  * Returns either NF_ACCEPT or NF_DROP.
219  */
220 static int ct_nat_execute(struct sk_buff *skb, struct nf_conn *ct,
221 			  enum ip_conntrack_info ctinfo,
222 			  const struct nf_nat_range2 *range,
223 			  enum nf_nat_manip_type maniptype)
224 {
225 	int hooknum, err = NF_ACCEPT;
226 
227 	/* See HOOK2MANIP(). */
228 	if (maniptype == NF_NAT_MANIP_SRC)
229 		hooknum = NF_INET_LOCAL_IN; /* Source NAT */
230 	else
231 		hooknum = NF_INET_LOCAL_OUT; /* Destination NAT */
232 
233 	switch (ctinfo) {
234 	case IP_CT_RELATED:
235 	case IP_CT_RELATED_REPLY:
236 		if (skb->protocol == htons(ETH_P_IP) &&
237 		    ip_hdr(skb)->protocol == IPPROTO_ICMP) {
238 			if (!nf_nat_icmp_reply_translation(skb, ct, ctinfo,
239 							   hooknum))
240 				err = NF_DROP;
241 			goto out;
242 		} else if (IS_ENABLED(CONFIG_IPV6) &&
243 			   skb->protocol == htons(ETH_P_IPV6)) {
244 			__be16 frag_off;
245 			u8 nexthdr = ipv6_hdr(skb)->nexthdr;
246 			int hdrlen = ipv6_skip_exthdr(skb,
247 						      sizeof(struct ipv6hdr),
248 						      &nexthdr, &frag_off);
249 
250 			if (hdrlen >= 0 && nexthdr == IPPROTO_ICMPV6) {
251 				if (!nf_nat_icmpv6_reply_translation(skb, ct,
252 								     ctinfo,
253 								     hooknum,
254 								     hdrlen))
255 					err = NF_DROP;
256 				goto out;
257 			}
258 		}
259 		/* Non-ICMP, fall thru to initialize if needed. */
260 		/* fall through */
261 	case IP_CT_NEW:
262 		/* Seen it before?  This can happen for loopback, retrans,
263 		 * or local packets.
264 		 */
265 		if (!nf_nat_initialized(ct, maniptype)) {
266 			/* Initialize according to the NAT action. */
267 			err = (range && range->flags & NF_NAT_RANGE_MAP_IPS)
268 				/* Action is set up to establish a new
269 				 * mapping.
270 				 */
271 				? nf_nat_setup_info(ct, range, maniptype)
272 				: nf_nat_alloc_null_binding(ct, hooknum);
273 			if (err != NF_ACCEPT)
274 				goto out;
275 		}
276 		break;
277 
278 	case IP_CT_ESTABLISHED:
279 	case IP_CT_ESTABLISHED_REPLY:
280 		break;
281 
282 	default:
283 		err = NF_DROP;
284 		goto out;
285 	}
286 
287 	err = nf_nat_packet(ct, ctinfo, hooknum, skb);
288 out:
289 	return err;
290 }
291 #endif /* CONFIG_NF_NAT */
292 
293 static void tcf_ct_act_set_mark(struct nf_conn *ct, u32 mark, u32 mask)
294 {
295 #if IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)
296 	u32 new_mark;
297 
298 	if (!mask)
299 		return;
300 
301 	new_mark = mark | (ct->mark & ~(mask));
302 	if (ct->mark != new_mark) {
303 		ct->mark = new_mark;
304 		if (nf_ct_is_confirmed(ct))
305 			nf_conntrack_event_cache(IPCT_MARK, ct);
306 	}
307 #endif
308 }
309 
310 static void tcf_ct_act_set_labels(struct nf_conn *ct,
311 				  u32 *labels,
312 				  u32 *labels_m)
313 {
314 #if IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)
315 	size_t labels_sz = sizeof_field(struct tcf_ct_params, labels);
316 
317 	if (!memchr_inv(labels_m, 0, labels_sz))
318 		return;
319 
320 	nf_connlabels_replace(ct, labels, labels_m, 4);
321 #endif
322 }
323 
324 static int tcf_ct_act_nat(struct sk_buff *skb,
325 			  struct nf_conn *ct,
326 			  enum ip_conntrack_info ctinfo,
327 			  int ct_action,
328 			  struct nf_nat_range2 *range,
329 			  bool commit)
330 {
331 #if IS_ENABLED(CONFIG_NF_NAT)
332 	int err;
333 	enum nf_nat_manip_type maniptype;
334 
335 	if (!(ct_action & TCA_CT_ACT_NAT))
336 		return NF_ACCEPT;
337 
338 	/* Add NAT extension if not confirmed yet. */
339 	if (!nf_ct_is_confirmed(ct) && !nf_ct_nat_ext_add(ct))
340 		return NF_DROP;   /* Can't NAT. */
341 
342 	if (ctinfo != IP_CT_NEW && (ct->status & IPS_NAT_MASK) &&
343 	    (ctinfo != IP_CT_RELATED || commit)) {
344 		/* NAT an established or related connection like before. */
345 		if (CTINFO2DIR(ctinfo) == IP_CT_DIR_REPLY)
346 			/* This is the REPLY direction for a connection
347 			 * for which NAT was applied in the forward
348 			 * direction.  Do the reverse NAT.
349 			 */
350 			maniptype = ct->status & IPS_SRC_NAT
351 				? NF_NAT_MANIP_DST : NF_NAT_MANIP_SRC;
352 		else
353 			maniptype = ct->status & IPS_SRC_NAT
354 				? NF_NAT_MANIP_SRC : NF_NAT_MANIP_DST;
355 	} else if (ct_action & TCA_CT_ACT_NAT_SRC) {
356 		maniptype = NF_NAT_MANIP_SRC;
357 	} else if (ct_action & TCA_CT_ACT_NAT_DST) {
358 		maniptype = NF_NAT_MANIP_DST;
359 	} else {
360 		return NF_ACCEPT;
361 	}
362 
363 	err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
364 	if (err == NF_ACCEPT &&
365 	    ct->status & IPS_SRC_NAT && ct->status & IPS_DST_NAT) {
366 		if (maniptype == NF_NAT_MANIP_SRC)
367 			maniptype = NF_NAT_MANIP_DST;
368 		else
369 			maniptype = NF_NAT_MANIP_SRC;
370 
371 		err = ct_nat_execute(skb, ct, ctinfo, range, maniptype);
372 	}
373 	return err;
374 #else
375 	return NF_ACCEPT;
376 #endif
377 }
378 
379 static int tcf_ct_act(struct sk_buff *skb, const struct tc_action *a,
380 		      struct tcf_result *res)
381 {
382 	struct net *net = dev_net(skb->dev);
383 	bool cached, commit, clear, force;
384 	enum ip_conntrack_info ctinfo;
385 	struct tcf_ct *c = to_ct(a);
386 	struct nf_conn *tmpl = NULL;
387 	struct nf_hook_state state;
388 	int nh_ofs, err, retval;
389 	struct tcf_ct_params *p;
390 	struct nf_conn *ct;
391 	u8 family;
392 
393 	p = rcu_dereference_bh(c->params);
394 
395 	retval = READ_ONCE(c->tcf_action);
396 	commit = p->ct_action & TCA_CT_ACT_COMMIT;
397 	clear = p->ct_action & TCA_CT_ACT_CLEAR;
398 	force = p->ct_action & TCA_CT_ACT_FORCE;
399 	tmpl = p->tmpl;
400 
401 	if (clear) {
402 		ct = nf_ct_get(skb, &ctinfo);
403 		if (ct) {
404 			nf_conntrack_put(&ct->ct_general);
405 			nf_ct_set(skb, NULL, IP_CT_UNTRACKED);
406 		}
407 
408 		goto out;
409 	}
410 
411 	family = tcf_ct_skb_nf_family(skb);
412 	if (family == NFPROTO_UNSPEC)
413 		goto drop;
414 
415 	/* The conntrack module expects to be working at L3.
416 	 * We also try to pull the IPv4/6 header to linear area
417 	 */
418 	nh_ofs = skb_network_offset(skb);
419 	skb_pull_rcsum(skb, nh_ofs);
420 	err = tcf_ct_handle_fragments(net, skb, family, p->zone);
421 	if (err == -EINPROGRESS) {
422 		retval = TC_ACT_STOLEN;
423 		goto out;
424 	}
425 	if (err)
426 		goto drop;
427 
428 	err = tcf_ct_skb_network_trim(skb, family);
429 	if (err)
430 		goto drop;
431 
432 	/* If we are recirculating packets to match on ct fields and
433 	 * committing with a separate ct action, then we don't need to
434 	 * actually run the packet through conntrack twice unless it's for a
435 	 * different zone.
436 	 */
437 	cached = tcf_ct_skb_nfct_cached(net, skb, p->zone, force);
438 	if (!cached) {
439 		/* Associate skb with specified zone. */
440 		if (tmpl) {
441 			ct = nf_ct_get(skb, &ctinfo);
442 			if (skb_nfct(skb))
443 				nf_conntrack_put(skb_nfct(skb));
444 			nf_conntrack_get(&tmpl->ct_general);
445 			nf_ct_set(skb, tmpl, IP_CT_NEW);
446 		}
447 
448 		state.hook = NF_INET_PRE_ROUTING;
449 		state.net = net;
450 		state.pf = family;
451 		err = nf_conntrack_in(skb, &state);
452 		if (err != NF_ACCEPT)
453 			goto out_push;
454 	}
455 
456 	ct = nf_ct_get(skb, &ctinfo);
457 	if (!ct)
458 		goto out_push;
459 	nf_ct_deliver_cached_events(ct);
460 
461 	err = tcf_ct_act_nat(skb, ct, ctinfo, p->ct_action, &p->range, commit);
462 	if (err != NF_ACCEPT)
463 		goto drop;
464 
465 	if (commit) {
466 		tcf_ct_act_set_mark(ct, p->mark, p->mark_mask);
467 		tcf_ct_act_set_labels(ct, p->labels, p->labels_mask);
468 
469 		/* This will take care of sending queued events
470 		 * even if the connection is already confirmed.
471 		 */
472 		nf_conntrack_confirm(skb);
473 	}
474 
475 out_push:
476 	skb_push_rcsum(skb, nh_ofs);
477 
478 out:
479 	tcf_action_update_bstats(&c->common, skb);
480 	return retval;
481 
482 drop:
483 	tcf_action_inc_drop_qstats(&c->common);
484 	return TC_ACT_SHOT;
485 }
486 
487 static const struct nla_policy ct_policy[TCA_CT_MAX + 1] = {
488 	[TCA_CT_ACTION] = { .type = NLA_U16 },
489 	[TCA_CT_PARMS] = { .type = NLA_EXACT_LEN, .len = sizeof(struct tc_ct) },
490 	[TCA_CT_ZONE] = { .type = NLA_U16 },
491 	[TCA_CT_MARK] = { .type = NLA_U32 },
492 	[TCA_CT_MARK_MASK] = { .type = NLA_U32 },
493 	[TCA_CT_LABELS] = { .type = NLA_BINARY,
494 			    .len = 128 / BITS_PER_BYTE },
495 	[TCA_CT_LABELS_MASK] = { .type = NLA_BINARY,
496 				 .len = 128 / BITS_PER_BYTE },
497 	[TCA_CT_NAT_IPV4_MIN] = { .type = NLA_U32 },
498 	[TCA_CT_NAT_IPV4_MAX] = { .type = NLA_U32 },
499 	[TCA_CT_NAT_IPV6_MIN] = { .type = NLA_EXACT_LEN,
500 				  .len = sizeof(struct in6_addr) },
501 	[TCA_CT_NAT_IPV6_MAX] = { .type = NLA_EXACT_LEN,
502 				   .len = sizeof(struct in6_addr) },
503 	[TCA_CT_NAT_PORT_MIN] = { .type = NLA_U16 },
504 	[TCA_CT_NAT_PORT_MAX] = { .type = NLA_U16 },
505 };
506 
507 static int tcf_ct_fill_params_nat(struct tcf_ct_params *p,
508 				  struct tc_ct *parm,
509 				  struct nlattr **tb,
510 				  struct netlink_ext_ack *extack)
511 {
512 	struct nf_nat_range2 *range;
513 
514 	if (!(p->ct_action & TCA_CT_ACT_NAT))
515 		return 0;
516 
517 	if (!IS_ENABLED(CONFIG_NF_NAT)) {
518 		NL_SET_ERR_MSG_MOD(extack, "Netfilter nat isn't enabled in kernel");
519 		return -EOPNOTSUPP;
520 	}
521 
522 	if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
523 		return 0;
524 
525 	if ((p->ct_action & TCA_CT_ACT_NAT_SRC) &&
526 	    (p->ct_action & TCA_CT_ACT_NAT_DST)) {
527 		NL_SET_ERR_MSG_MOD(extack, "dnat and snat can't be enabled at the same time");
528 		return -EOPNOTSUPP;
529 	}
530 
531 	range = &p->range;
532 	if (tb[TCA_CT_NAT_IPV4_MIN]) {
533 		struct nlattr *max_attr = tb[TCA_CT_NAT_IPV4_MAX];
534 
535 		p->ipv4_range = true;
536 		range->flags |= NF_NAT_RANGE_MAP_IPS;
537 		range->min_addr.ip =
538 			nla_get_in_addr(tb[TCA_CT_NAT_IPV4_MIN]);
539 
540 		range->max_addr.ip = max_attr ?
541 				     nla_get_in_addr(max_attr) :
542 				     range->min_addr.ip;
543 	} else if (tb[TCA_CT_NAT_IPV6_MIN]) {
544 		struct nlattr *max_attr = tb[TCA_CT_NAT_IPV6_MAX];
545 
546 		p->ipv4_range = false;
547 		range->flags |= NF_NAT_RANGE_MAP_IPS;
548 		range->min_addr.in6 =
549 			nla_get_in6_addr(tb[TCA_CT_NAT_IPV6_MIN]);
550 
551 		range->max_addr.in6 = max_attr ?
552 				      nla_get_in6_addr(max_attr) :
553 				      range->min_addr.in6;
554 	}
555 
556 	if (tb[TCA_CT_NAT_PORT_MIN]) {
557 		range->flags |= NF_NAT_RANGE_PROTO_SPECIFIED;
558 		range->min_proto.all = nla_get_be16(tb[TCA_CT_NAT_PORT_MIN]);
559 
560 		range->max_proto.all = tb[TCA_CT_NAT_PORT_MAX] ?
561 				       nla_get_be16(tb[TCA_CT_NAT_PORT_MAX]) :
562 				       range->min_proto.all;
563 	}
564 
565 	return 0;
566 }
567 
568 static void tcf_ct_set_key_val(struct nlattr **tb,
569 			       void *val, int val_type,
570 			       void *mask, int mask_type,
571 			       int len)
572 {
573 	if (!tb[val_type])
574 		return;
575 	nla_memcpy(val, tb[val_type], len);
576 
577 	if (!mask)
578 		return;
579 
580 	if (mask_type == TCA_CT_UNSPEC || !tb[mask_type])
581 		memset(mask, 0xff, len);
582 	else
583 		nla_memcpy(mask, tb[mask_type], len);
584 }
585 
586 static int tcf_ct_fill_params(struct net *net,
587 			      struct tcf_ct_params *p,
588 			      struct tc_ct *parm,
589 			      struct nlattr **tb,
590 			      struct netlink_ext_ack *extack)
591 {
592 	struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
593 	struct nf_conntrack_zone zone;
594 	struct nf_conn *tmpl;
595 	int err;
596 
597 	p->zone = NF_CT_DEFAULT_ZONE_ID;
598 
599 	tcf_ct_set_key_val(tb,
600 			   &p->ct_action, TCA_CT_ACTION,
601 			   NULL, TCA_CT_UNSPEC,
602 			   sizeof(p->ct_action));
603 
604 	if (p->ct_action & TCA_CT_ACT_CLEAR)
605 		return 0;
606 
607 	err = tcf_ct_fill_params_nat(p, parm, tb, extack);
608 	if (err)
609 		return err;
610 
611 	if (tb[TCA_CT_MARK]) {
612 		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_MARK)) {
613 			NL_SET_ERR_MSG_MOD(extack, "Conntrack mark isn't enabled.");
614 			return -EOPNOTSUPP;
615 		}
616 		tcf_ct_set_key_val(tb,
617 				   &p->mark, TCA_CT_MARK,
618 				   &p->mark_mask, TCA_CT_MARK_MASK,
619 				   sizeof(p->mark));
620 	}
621 
622 	if (tb[TCA_CT_LABELS]) {
623 		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS)) {
624 			NL_SET_ERR_MSG_MOD(extack, "Conntrack labels isn't enabled.");
625 			return -EOPNOTSUPP;
626 		}
627 
628 		if (!tn->labels) {
629 			NL_SET_ERR_MSG_MOD(extack, "Failed to set connlabel length");
630 			return -EOPNOTSUPP;
631 		}
632 		tcf_ct_set_key_val(tb,
633 				   p->labels, TCA_CT_LABELS,
634 				   p->labels_mask, TCA_CT_LABELS_MASK,
635 				   sizeof(p->labels));
636 	}
637 
638 	if (tb[TCA_CT_ZONE]) {
639 		if (!IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES)) {
640 			NL_SET_ERR_MSG_MOD(extack, "Conntrack zones isn't enabled.");
641 			return -EOPNOTSUPP;
642 		}
643 
644 		tcf_ct_set_key_val(tb,
645 				   &p->zone, TCA_CT_ZONE,
646 				   NULL, TCA_CT_UNSPEC,
647 				   sizeof(p->zone));
648 	}
649 
650 	if (p->zone == NF_CT_DEFAULT_ZONE_ID)
651 		return 0;
652 
653 	nf_ct_zone_init(&zone, p->zone, NF_CT_DEFAULT_ZONE_DIR, 0);
654 	tmpl = nf_ct_tmpl_alloc(net, &zone, GFP_KERNEL);
655 	if (!tmpl) {
656 		NL_SET_ERR_MSG_MOD(extack, "Failed to allocate conntrack template");
657 		return -ENOMEM;
658 	}
659 	__set_bit(IPS_CONFIRMED_BIT, &tmpl->status);
660 	nf_conntrack_get(&tmpl->ct_general);
661 	p->tmpl = tmpl;
662 
663 	return 0;
664 }
665 
666 static int tcf_ct_init(struct net *net, struct nlattr *nla,
667 		       struct nlattr *est, struct tc_action **a,
668 		       int replace, int bind, bool rtnl_held,
669 		       struct tcf_proto *tp, u32 flags,
670 		       struct netlink_ext_ack *extack)
671 {
672 	struct tc_action_net *tn = net_generic(net, ct_net_id);
673 	struct tcf_ct_params *params = NULL;
674 	struct nlattr *tb[TCA_CT_MAX + 1];
675 	struct tcf_chain *goto_ch = NULL;
676 	struct tc_ct *parm;
677 	struct tcf_ct *c;
678 	int err, res = 0;
679 	u32 index;
680 
681 	if (!nla) {
682 		NL_SET_ERR_MSG_MOD(extack, "Ct requires attributes to be passed");
683 		return -EINVAL;
684 	}
685 
686 	err = nla_parse_nested(tb, TCA_CT_MAX, nla, ct_policy, extack);
687 	if (err < 0)
688 		return err;
689 
690 	if (!tb[TCA_CT_PARMS]) {
691 		NL_SET_ERR_MSG_MOD(extack, "Missing required ct parameters");
692 		return -EINVAL;
693 	}
694 	parm = nla_data(tb[TCA_CT_PARMS]);
695 	index = parm->index;
696 	err = tcf_idr_check_alloc(tn, &index, a, bind);
697 	if (err < 0)
698 		return err;
699 
700 	if (!err) {
701 		err = tcf_idr_create_from_flags(tn, index, est, a,
702 						&act_ct_ops, bind, flags);
703 		if (err) {
704 			tcf_idr_cleanup(tn, index);
705 			return err;
706 		}
707 		res = ACT_P_CREATED;
708 	} else {
709 		if (bind)
710 			return 0;
711 
712 		if (!replace) {
713 			tcf_idr_release(*a, bind);
714 			return -EEXIST;
715 		}
716 	}
717 	err = tcf_action_check_ctrlact(parm->action, tp, &goto_ch, extack);
718 	if (err < 0)
719 		goto cleanup;
720 
721 	c = to_ct(*a);
722 
723 	params = kzalloc(sizeof(*params), GFP_KERNEL);
724 	if (unlikely(!params)) {
725 		err = -ENOMEM;
726 		goto cleanup;
727 	}
728 
729 	err = tcf_ct_fill_params(net, params, parm, tb, extack);
730 	if (err)
731 		goto cleanup;
732 
733 	spin_lock_bh(&c->tcf_lock);
734 	goto_ch = tcf_action_set_ctrlact(*a, parm->action, goto_ch);
735 	params = rcu_replace_pointer(c->params, params,
736 				     lockdep_is_held(&c->tcf_lock));
737 	spin_unlock_bh(&c->tcf_lock);
738 
739 	if (goto_ch)
740 		tcf_chain_put_by_act(goto_ch);
741 	if (params)
742 		kfree_rcu(params, rcu);
743 	if (res == ACT_P_CREATED)
744 		tcf_idr_insert(tn, *a);
745 
746 	return res;
747 
748 cleanup:
749 	if (goto_ch)
750 		tcf_chain_put_by_act(goto_ch);
751 	kfree(params);
752 	tcf_idr_release(*a, bind);
753 	return err;
754 }
755 
756 static void tcf_ct_cleanup(struct tc_action *a)
757 {
758 	struct tcf_ct_params *params;
759 	struct tcf_ct *c = to_ct(a);
760 
761 	params = rcu_dereference_protected(c->params, 1);
762 	if (params)
763 		call_rcu(&params->rcu, tcf_ct_params_free);
764 }
765 
766 static int tcf_ct_dump_key_val(struct sk_buff *skb,
767 			       void *val, int val_type,
768 			       void *mask, int mask_type,
769 			       int len)
770 {
771 	int err;
772 
773 	if (mask && !memchr_inv(mask, 0, len))
774 		return 0;
775 
776 	err = nla_put(skb, val_type, len, val);
777 	if (err)
778 		return err;
779 
780 	if (mask_type != TCA_CT_UNSPEC) {
781 		err = nla_put(skb, mask_type, len, mask);
782 		if (err)
783 			return err;
784 	}
785 
786 	return 0;
787 }
788 
789 static int tcf_ct_dump_nat(struct sk_buff *skb, struct tcf_ct_params *p)
790 {
791 	struct nf_nat_range2 *range = &p->range;
792 
793 	if (!(p->ct_action & TCA_CT_ACT_NAT))
794 		return 0;
795 
796 	if (!(p->ct_action & (TCA_CT_ACT_NAT_SRC | TCA_CT_ACT_NAT_DST)))
797 		return 0;
798 
799 	if (range->flags & NF_NAT_RANGE_MAP_IPS) {
800 		if (p->ipv4_range) {
801 			if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MIN,
802 					    range->min_addr.ip))
803 				return -1;
804 			if (nla_put_in_addr(skb, TCA_CT_NAT_IPV4_MAX,
805 					    range->max_addr.ip))
806 				return -1;
807 		} else {
808 			if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MIN,
809 					     &range->min_addr.in6))
810 				return -1;
811 			if (nla_put_in6_addr(skb, TCA_CT_NAT_IPV6_MAX,
812 					     &range->max_addr.in6))
813 				return -1;
814 		}
815 	}
816 
817 	if (range->flags & NF_NAT_RANGE_PROTO_SPECIFIED) {
818 		if (nla_put_be16(skb, TCA_CT_NAT_PORT_MIN,
819 				 range->min_proto.all))
820 			return -1;
821 		if (nla_put_be16(skb, TCA_CT_NAT_PORT_MAX,
822 				 range->max_proto.all))
823 			return -1;
824 	}
825 
826 	return 0;
827 }
828 
829 static inline int tcf_ct_dump(struct sk_buff *skb, struct tc_action *a,
830 			      int bind, int ref)
831 {
832 	unsigned char *b = skb_tail_pointer(skb);
833 	struct tcf_ct *c = to_ct(a);
834 	struct tcf_ct_params *p;
835 
836 	struct tc_ct opt = {
837 		.index   = c->tcf_index,
838 		.refcnt  = refcount_read(&c->tcf_refcnt) - ref,
839 		.bindcnt = atomic_read(&c->tcf_bindcnt) - bind,
840 	};
841 	struct tcf_t t;
842 
843 	spin_lock_bh(&c->tcf_lock);
844 	p = rcu_dereference_protected(c->params,
845 				      lockdep_is_held(&c->tcf_lock));
846 	opt.action = c->tcf_action;
847 
848 	if (tcf_ct_dump_key_val(skb,
849 				&p->ct_action, TCA_CT_ACTION,
850 				NULL, TCA_CT_UNSPEC,
851 				sizeof(p->ct_action)))
852 		goto nla_put_failure;
853 
854 	if (p->ct_action & TCA_CT_ACT_CLEAR)
855 		goto skip_dump;
856 
857 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_MARK) &&
858 	    tcf_ct_dump_key_val(skb,
859 				&p->mark, TCA_CT_MARK,
860 				&p->mark_mask, TCA_CT_MARK_MASK,
861 				sizeof(p->mark)))
862 		goto nla_put_failure;
863 
864 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_LABELS) &&
865 	    tcf_ct_dump_key_val(skb,
866 				p->labels, TCA_CT_LABELS,
867 				p->labels_mask, TCA_CT_LABELS_MASK,
868 				sizeof(p->labels)))
869 		goto nla_put_failure;
870 
871 	if (IS_ENABLED(CONFIG_NF_CONNTRACK_ZONES) &&
872 	    tcf_ct_dump_key_val(skb,
873 				&p->zone, TCA_CT_ZONE,
874 				NULL, TCA_CT_UNSPEC,
875 				sizeof(p->zone)))
876 		goto nla_put_failure;
877 
878 	if (tcf_ct_dump_nat(skb, p))
879 		goto nla_put_failure;
880 
881 skip_dump:
882 	if (nla_put(skb, TCA_CT_PARMS, sizeof(opt), &opt))
883 		goto nla_put_failure;
884 
885 	tcf_tm_dump(&t, &c->tcf_tm);
886 	if (nla_put_64bit(skb, TCA_CT_TM, sizeof(t), &t, TCA_CT_PAD))
887 		goto nla_put_failure;
888 	spin_unlock_bh(&c->tcf_lock);
889 
890 	return skb->len;
891 nla_put_failure:
892 	spin_unlock_bh(&c->tcf_lock);
893 	nlmsg_trim(skb, b);
894 	return -1;
895 }
896 
897 static int tcf_ct_walker(struct net *net, struct sk_buff *skb,
898 			 struct netlink_callback *cb, int type,
899 			 const struct tc_action_ops *ops,
900 			 struct netlink_ext_ack *extack)
901 {
902 	struct tc_action_net *tn = net_generic(net, ct_net_id);
903 
904 	return tcf_generic_walker(tn, skb, cb, type, ops, extack);
905 }
906 
907 static int tcf_ct_search(struct net *net, struct tc_action **a, u32 index)
908 {
909 	struct tc_action_net *tn = net_generic(net, ct_net_id);
910 
911 	return tcf_idr_search(tn, a, index);
912 }
913 
914 static void tcf_stats_update(struct tc_action *a, u64 bytes, u32 packets,
915 			     u64 lastuse, bool hw)
916 {
917 	struct tcf_ct *c = to_ct(a);
918 
919 	tcf_action_update_stats(a, bytes, packets, false, hw);
920 	c->tcf_tm.lastuse = max_t(u64, c->tcf_tm.lastuse, lastuse);
921 }
922 
923 static struct tc_action_ops act_ct_ops = {
924 	.kind		=	"ct",
925 	.id		=	TCA_ID_CT,
926 	.owner		=	THIS_MODULE,
927 	.act		=	tcf_ct_act,
928 	.dump		=	tcf_ct_dump,
929 	.init		=	tcf_ct_init,
930 	.cleanup	=	tcf_ct_cleanup,
931 	.walk		=	tcf_ct_walker,
932 	.lookup		=	tcf_ct_search,
933 	.stats_update	=	tcf_stats_update,
934 	.size		=	sizeof(struct tcf_ct),
935 };
936 
937 static __net_init int ct_init_net(struct net *net)
938 {
939 	unsigned int n_bits = sizeof_field(struct tcf_ct_params, labels) * 8;
940 	struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
941 
942 	if (nf_connlabels_get(net, n_bits - 1)) {
943 		tn->labels = false;
944 		pr_err("act_ct: Failed to set connlabels length");
945 	} else {
946 		tn->labels = true;
947 	}
948 
949 	return tc_action_net_init(net, &tn->tn, &act_ct_ops);
950 }
951 
952 static void __net_exit ct_exit_net(struct list_head *net_list)
953 {
954 	struct net *net;
955 
956 	rtnl_lock();
957 	list_for_each_entry(net, net_list, exit_list) {
958 		struct tc_ct_action_net *tn = net_generic(net, ct_net_id);
959 
960 		if (tn->labels)
961 			nf_connlabels_put(net);
962 	}
963 	rtnl_unlock();
964 
965 	tc_action_net_exit(net_list, ct_net_id);
966 }
967 
968 static struct pernet_operations ct_net_ops = {
969 	.init = ct_init_net,
970 	.exit_batch = ct_exit_net,
971 	.id   = &ct_net_id,
972 	.size = sizeof(struct tc_ct_action_net),
973 };
974 
975 static int __init ct_init_module(void)
976 {
977 	return tcf_register_action(&act_ct_ops, &ct_net_ops);
978 }
979 
980 static void __exit ct_cleanup_module(void)
981 {
982 	tcf_unregister_action(&act_ct_ops, &ct_net_ops);
983 }
984 
985 module_init(ct_init_module);
986 module_exit(ct_cleanup_module);
987 MODULE_AUTHOR("Paul Blakey <paulb@mellanox.com>");
988 MODULE_AUTHOR("Yossi Kuperman <yossiku@mellanox.com>");
989 MODULE_AUTHOR("Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>");
990 MODULE_DESCRIPTION("Connection tracking action");
991 MODULE_LICENSE("GPL v2");
992 
993