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1 /* Connection tracking via netlink socket. Allows for user space
2  * protocol helpers and general trouble making from userspace.
3  *
4  * (C) 2001 by Jay Schulist <jschlst@samba.org>
5  * (C) 2002-2006 by Harald Welte <laforge@gnumonks.org>
6  * (C) 2003 by Patrick Mchardy <kaber@trash.net>
7  * (C) 2005-2012 by Pablo Neira Ayuso <pablo@netfilter.org>
8  *
9  * Initial connection tracking via netlink development funded and
10  * generally made possible by Network Robots, Inc. (www.networkrobots.com)
11  *
12  * Further development of this code funded by Astaro AG (http://www.astaro.com)
13  *
14  * This software may be used and distributed according to the terms
15  * of the GNU General Public License, incorporated herein by reference.
16  */
17 
18 #include <linux/init.h>
19 #include <linux/module.h>
20 #include <linux/kernel.h>
21 #include <linux/rculist.h>
22 #include <linux/rculist_nulls.h>
23 #include <linux/types.h>
24 #include <linux/timer.h>
25 #include <linux/security.h>
26 #include <linux/skbuff.h>
27 #include <linux/errno.h>
28 #include <linux/netlink.h>
29 #include <linux/spinlock.h>
30 #include <linux/interrupt.h>
31 #include <linux/slab.h>
32 #include <linux/siphash.h>
33 
34 #include <linux/netfilter.h>
35 #include <net/netlink.h>
36 #include <net/sock.h>
37 #include <net/netfilter/nf_conntrack.h>
38 #include <net/netfilter/nf_conntrack_core.h>
39 #include <net/netfilter/nf_conntrack_expect.h>
40 #include <net/netfilter/nf_conntrack_helper.h>
41 #include <net/netfilter/nf_conntrack_seqadj.h>
42 #include <net/netfilter/nf_conntrack_l4proto.h>
43 #include <net/netfilter/nf_conntrack_tuple.h>
44 #include <net/netfilter/nf_conntrack_acct.h>
45 #include <net/netfilter/nf_conntrack_zones.h>
46 #include <net/netfilter/nf_conntrack_timestamp.h>
47 #include <net/netfilter/nf_conntrack_labels.h>
48 #include <net/netfilter/nf_conntrack_synproxy.h>
49 #if IS_ENABLED(CONFIG_NF_NAT)
50 #include <net/netfilter/nf_nat.h>
51 #include <net/netfilter/nf_nat_helper.h>
52 #endif
53 
54 #include <linux/netfilter/nfnetlink.h>
55 #include <linux/netfilter/nfnetlink_conntrack.h>
56 
57 #include "nf_internals.h"
58 
59 MODULE_LICENSE("GPL");
60 
ctnetlink_dump_tuples_proto(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple,const struct nf_conntrack_l4proto * l4proto)61 static int ctnetlink_dump_tuples_proto(struct sk_buff *skb,
62 				const struct nf_conntrack_tuple *tuple,
63 				const struct nf_conntrack_l4proto *l4proto)
64 {
65 	int ret = 0;
66 	struct nlattr *nest_parms;
67 
68 	nest_parms = nla_nest_start(skb, CTA_TUPLE_PROTO);
69 	if (!nest_parms)
70 		goto nla_put_failure;
71 	if (nla_put_u8(skb, CTA_PROTO_NUM, tuple->dst.protonum))
72 		goto nla_put_failure;
73 
74 	if (likely(l4proto->tuple_to_nlattr))
75 		ret = l4proto->tuple_to_nlattr(skb, tuple);
76 
77 	nla_nest_end(skb, nest_parms);
78 
79 	return ret;
80 
81 nla_put_failure:
82 	return -1;
83 }
84 
ipv4_tuple_to_nlattr(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple)85 static int ipv4_tuple_to_nlattr(struct sk_buff *skb,
86 				const struct nf_conntrack_tuple *tuple)
87 {
88 	if (nla_put_in_addr(skb, CTA_IP_V4_SRC, tuple->src.u3.ip) ||
89 	    nla_put_in_addr(skb, CTA_IP_V4_DST, tuple->dst.u3.ip))
90 		return -EMSGSIZE;
91 	return 0;
92 }
93 
ipv6_tuple_to_nlattr(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple)94 static int ipv6_tuple_to_nlattr(struct sk_buff *skb,
95 				const struct nf_conntrack_tuple *tuple)
96 {
97 	if (nla_put_in6_addr(skb, CTA_IP_V6_SRC, &tuple->src.u3.in6) ||
98 	    nla_put_in6_addr(skb, CTA_IP_V6_DST, &tuple->dst.u3.in6))
99 		return -EMSGSIZE;
100 	return 0;
101 }
102 
ctnetlink_dump_tuples_ip(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple)103 static int ctnetlink_dump_tuples_ip(struct sk_buff *skb,
104 				    const struct nf_conntrack_tuple *tuple)
105 {
106 	int ret = 0;
107 	struct nlattr *nest_parms;
108 
109 	nest_parms = nla_nest_start(skb, CTA_TUPLE_IP);
110 	if (!nest_parms)
111 		goto nla_put_failure;
112 
113 	switch (tuple->src.l3num) {
114 	case NFPROTO_IPV4:
115 		ret = ipv4_tuple_to_nlattr(skb, tuple);
116 		break;
117 	case NFPROTO_IPV6:
118 		ret = ipv6_tuple_to_nlattr(skb, tuple);
119 		break;
120 	}
121 
122 	nla_nest_end(skb, nest_parms);
123 
124 	return ret;
125 
126 nla_put_failure:
127 	return -1;
128 }
129 
ctnetlink_dump_tuples(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple)130 static int ctnetlink_dump_tuples(struct sk_buff *skb,
131 				 const struct nf_conntrack_tuple *tuple)
132 {
133 	const struct nf_conntrack_l4proto *l4proto;
134 	int ret;
135 
136 	rcu_read_lock();
137 	ret = ctnetlink_dump_tuples_ip(skb, tuple);
138 
139 	if (ret >= 0) {
140 		l4proto = nf_ct_l4proto_find(tuple->dst.protonum);
141 		ret = ctnetlink_dump_tuples_proto(skb, tuple, l4proto);
142 	}
143 	rcu_read_unlock();
144 	return ret;
145 }
146 
ctnetlink_dump_zone_id(struct sk_buff * skb,int attrtype,const struct nf_conntrack_zone * zone,int dir)147 static int ctnetlink_dump_zone_id(struct sk_buff *skb, int attrtype,
148 				  const struct nf_conntrack_zone *zone, int dir)
149 {
150 	if (zone->id == NF_CT_DEFAULT_ZONE_ID || zone->dir != dir)
151 		return 0;
152 	if (nla_put_be16(skb, attrtype, htons(zone->id)))
153 		goto nla_put_failure;
154 	return 0;
155 
156 nla_put_failure:
157 	return -1;
158 }
159 
ctnetlink_dump_status(struct sk_buff * skb,const struct nf_conn * ct)160 static int ctnetlink_dump_status(struct sk_buff *skb, const struct nf_conn *ct)
161 {
162 	if (nla_put_be32(skb, CTA_STATUS, htonl(ct->status)))
163 		goto nla_put_failure;
164 	return 0;
165 
166 nla_put_failure:
167 	return -1;
168 }
169 
ctnetlink_dump_timeout(struct sk_buff * skb,const struct nf_conn * ct)170 static int ctnetlink_dump_timeout(struct sk_buff *skb, const struct nf_conn *ct)
171 {
172 	long timeout = nf_ct_expires(ct) / HZ;
173 
174 	if (nla_put_be32(skb, CTA_TIMEOUT, htonl(timeout)))
175 		goto nla_put_failure;
176 	return 0;
177 
178 nla_put_failure:
179 	return -1;
180 }
181 
ctnetlink_dump_protoinfo(struct sk_buff * skb,struct nf_conn * ct)182 static int ctnetlink_dump_protoinfo(struct sk_buff *skb, struct nf_conn *ct)
183 {
184 	const struct nf_conntrack_l4proto *l4proto;
185 	struct nlattr *nest_proto;
186 	int ret;
187 
188 	l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
189 	if (!l4proto->to_nlattr)
190 		return 0;
191 
192 	nest_proto = nla_nest_start(skb, CTA_PROTOINFO);
193 	if (!nest_proto)
194 		goto nla_put_failure;
195 
196 	ret = l4proto->to_nlattr(skb, nest_proto, ct);
197 
198 	nla_nest_end(skb, nest_proto);
199 
200 	return ret;
201 
202 nla_put_failure:
203 	return -1;
204 }
205 
ctnetlink_dump_helpinfo(struct sk_buff * skb,const struct nf_conn * ct)206 static int ctnetlink_dump_helpinfo(struct sk_buff *skb,
207 				   const struct nf_conn *ct)
208 {
209 	struct nlattr *nest_helper;
210 	const struct nf_conn_help *help = nfct_help(ct);
211 	struct nf_conntrack_helper *helper;
212 
213 	if (!help)
214 		return 0;
215 
216 	rcu_read_lock();
217 	helper = rcu_dereference(help->helper);
218 	if (!helper)
219 		goto out;
220 
221 	nest_helper = nla_nest_start(skb, CTA_HELP);
222 	if (!nest_helper)
223 		goto nla_put_failure;
224 	if (nla_put_string(skb, CTA_HELP_NAME, helper->name))
225 		goto nla_put_failure;
226 
227 	if (helper->to_nlattr)
228 		helper->to_nlattr(skb, ct);
229 
230 	nla_nest_end(skb, nest_helper);
231 out:
232 	rcu_read_unlock();
233 	return 0;
234 
235 nla_put_failure:
236 	rcu_read_unlock();
237 	return -1;
238 }
239 
240 static int
dump_counters(struct sk_buff * skb,struct nf_conn_acct * acct,enum ip_conntrack_dir dir,int type)241 dump_counters(struct sk_buff *skb, struct nf_conn_acct *acct,
242 	      enum ip_conntrack_dir dir, int type)
243 {
244 	enum ctattr_type attr = dir ? CTA_COUNTERS_REPLY: CTA_COUNTERS_ORIG;
245 	struct nf_conn_counter *counter = acct->counter;
246 	struct nlattr *nest_count;
247 	u64 pkts, bytes;
248 
249 	if (type == IPCTNL_MSG_CT_GET_CTRZERO) {
250 		pkts = atomic64_xchg(&counter[dir].packets, 0);
251 		bytes = atomic64_xchg(&counter[dir].bytes, 0);
252 	} else {
253 		pkts = atomic64_read(&counter[dir].packets);
254 		bytes = atomic64_read(&counter[dir].bytes);
255 	}
256 
257 	nest_count = nla_nest_start(skb, attr);
258 	if (!nest_count)
259 		goto nla_put_failure;
260 
261 	if (nla_put_be64(skb, CTA_COUNTERS_PACKETS, cpu_to_be64(pkts),
262 			 CTA_COUNTERS_PAD) ||
263 	    nla_put_be64(skb, CTA_COUNTERS_BYTES, cpu_to_be64(bytes),
264 			 CTA_COUNTERS_PAD))
265 		goto nla_put_failure;
266 
267 	nla_nest_end(skb, nest_count);
268 
269 	return 0;
270 
271 nla_put_failure:
272 	return -1;
273 }
274 
275 static int
ctnetlink_dump_acct(struct sk_buff * skb,const struct nf_conn * ct,int type)276 ctnetlink_dump_acct(struct sk_buff *skb, const struct nf_conn *ct, int type)
277 {
278 	struct nf_conn_acct *acct = nf_conn_acct_find(ct);
279 
280 	if (!acct)
281 		return 0;
282 
283 	if (dump_counters(skb, acct, IP_CT_DIR_ORIGINAL, type) < 0)
284 		return -1;
285 	if (dump_counters(skb, acct, IP_CT_DIR_REPLY, type) < 0)
286 		return -1;
287 
288 	return 0;
289 }
290 
291 static int
ctnetlink_dump_timestamp(struct sk_buff * skb,const struct nf_conn * ct)292 ctnetlink_dump_timestamp(struct sk_buff *skb, const struct nf_conn *ct)
293 {
294 	struct nlattr *nest_count;
295 	const struct nf_conn_tstamp *tstamp;
296 
297 	tstamp = nf_conn_tstamp_find(ct);
298 	if (!tstamp)
299 		return 0;
300 
301 	nest_count = nla_nest_start(skb, CTA_TIMESTAMP);
302 	if (!nest_count)
303 		goto nla_put_failure;
304 
305 	if (nla_put_be64(skb, CTA_TIMESTAMP_START, cpu_to_be64(tstamp->start),
306 			 CTA_TIMESTAMP_PAD) ||
307 	    (tstamp->stop != 0 && nla_put_be64(skb, CTA_TIMESTAMP_STOP,
308 					       cpu_to_be64(tstamp->stop),
309 					       CTA_TIMESTAMP_PAD)))
310 		goto nla_put_failure;
311 	nla_nest_end(skb, nest_count);
312 
313 	return 0;
314 
315 nla_put_failure:
316 	return -1;
317 }
318 
319 #ifdef CONFIG_NF_CONNTRACK_MARK
ctnetlink_dump_mark(struct sk_buff * skb,const struct nf_conn * ct,bool dump)320 static int ctnetlink_dump_mark(struct sk_buff *skb, const struct nf_conn *ct,
321 			       bool dump)
322 {
323 	u32 mark = READ_ONCE(ct->mark);
324 
325 	if (!mark && !dump)
326 		return 0;
327 
328 	if (nla_put_be32(skb, CTA_MARK, htonl(mark)))
329 		goto nla_put_failure;
330 	return 0;
331 
332 nla_put_failure:
333 	return -1;
334 }
335 #else
336 #define ctnetlink_dump_mark(a, b, c) (0)
337 #endif
338 
339 #ifdef CONFIG_NF_CONNTRACK_SECMARK
ctnetlink_dump_secctx(struct sk_buff * skb,const struct nf_conn * ct)340 static int ctnetlink_dump_secctx(struct sk_buff *skb, const struct nf_conn *ct)
341 {
342 	struct nlattr *nest_secctx;
343 	int len, ret;
344 	char *secctx;
345 
346 	ret = security_secid_to_secctx(ct->secmark, &secctx, &len);
347 	if (ret)
348 		return 0;
349 
350 	ret = -1;
351 	nest_secctx = nla_nest_start(skb, CTA_SECCTX);
352 	if (!nest_secctx)
353 		goto nla_put_failure;
354 
355 	if (nla_put_string(skb, CTA_SECCTX_NAME, secctx))
356 		goto nla_put_failure;
357 	nla_nest_end(skb, nest_secctx);
358 
359 	ret = 0;
360 nla_put_failure:
361 	security_release_secctx(secctx, len);
362 	return ret;
363 }
364 #else
365 #define ctnetlink_dump_secctx(a, b) (0)
366 #endif
367 
368 #ifdef CONFIG_NF_CONNTRACK_LABELS
ctnetlink_label_size(const struct nf_conn * ct)369 static inline int ctnetlink_label_size(const struct nf_conn *ct)
370 {
371 	struct nf_conn_labels *labels = nf_ct_labels_find(ct);
372 
373 	if (!labels)
374 		return 0;
375 	return nla_total_size(sizeof(labels->bits));
376 }
377 
378 static int
ctnetlink_dump_labels(struct sk_buff * skb,const struct nf_conn * ct)379 ctnetlink_dump_labels(struct sk_buff *skb, const struct nf_conn *ct)
380 {
381 	struct nf_conn_labels *labels = nf_ct_labels_find(ct);
382 	unsigned int i;
383 
384 	if (!labels)
385 		return 0;
386 
387 	i = 0;
388 	do {
389 		if (labels->bits[i] != 0)
390 			return nla_put(skb, CTA_LABELS, sizeof(labels->bits),
391 				       labels->bits);
392 		i++;
393 	} while (i < ARRAY_SIZE(labels->bits));
394 
395 	return 0;
396 }
397 #else
398 #define ctnetlink_dump_labels(a, b) (0)
399 #define ctnetlink_label_size(a)	(0)
400 #endif
401 
402 #define master_tuple(ct) &(ct->master->tuplehash[IP_CT_DIR_ORIGINAL].tuple)
403 
ctnetlink_dump_master(struct sk_buff * skb,const struct nf_conn * ct)404 static int ctnetlink_dump_master(struct sk_buff *skb, const struct nf_conn *ct)
405 {
406 	struct nlattr *nest_parms;
407 
408 	if (!(ct->status & IPS_EXPECTED))
409 		return 0;
410 
411 	nest_parms = nla_nest_start(skb, CTA_TUPLE_MASTER);
412 	if (!nest_parms)
413 		goto nla_put_failure;
414 	if (ctnetlink_dump_tuples(skb, master_tuple(ct)) < 0)
415 		goto nla_put_failure;
416 	nla_nest_end(skb, nest_parms);
417 
418 	return 0;
419 
420 nla_put_failure:
421 	return -1;
422 }
423 
424 static int
dump_ct_seq_adj(struct sk_buff * skb,const struct nf_ct_seqadj * seq,int type)425 dump_ct_seq_adj(struct sk_buff *skb, const struct nf_ct_seqadj *seq, int type)
426 {
427 	struct nlattr *nest_parms;
428 
429 	nest_parms = nla_nest_start(skb, type);
430 	if (!nest_parms)
431 		goto nla_put_failure;
432 
433 	if (nla_put_be32(skb, CTA_SEQADJ_CORRECTION_POS,
434 			 htonl(seq->correction_pos)) ||
435 	    nla_put_be32(skb, CTA_SEQADJ_OFFSET_BEFORE,
436 			 htonl(seq->offset_before)) ||
437 	    nla_put_be32(skb, CTA_SEQADJ_OFFSET_AFTER,
438 			 htonl(seq->offset_after)))
439 		goto nla_put_failure;
440 
441 	nla_nest_end(skb, nest_parms);
442 
443 	return 0;
444 
445 nla_put_failure:
446 	return -1;
447 }
448 
ctnetlink_dump_ct_seq_adj(struct sk_buff * skb,struct nf_conn * ct)449 static int ctnetlink_dump_ct_seq_adj(struct sk_buff *skb, struct nf_conn *ct)
450 {
451 	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
452 	struct nf_ct_seqadj *seq;
453 
454 	if (!(ct->status & IPS_SEQ_ADJUST) || !seqadj)
455 		return 0;
456 
457 	spin_lock_bh(&ct->lock);
458 	seq = &seqadj->seq[IP_CT_DIR_ORIGINAL];
459 	if (dump_ct_seq_adj(skb, seq, CTA_SEQ_ADJ_ORIG) == -1)
460 		goto err;
461 
462 	seq = &seqadj->seq[IP_CT_DIR_REPLY];
463 	if (dump_ct_seq_adj(skb, seq, CTA_SEQ_ADJ_REPLY) == -1)
464 		goto err;
465 
466 	spin_unlock_bh(&ct->lock);
467 	return 0;
468 err:
469 	spin_unlock_bh(&ct->lock);
470 	return -1;
471 }
472 
ctnetlink_dump_ct_synproxy(struct sk_buff * skb,struct nf_conn * ct)473 static int ctnetlink_dump_ct_synproxy(struct sk_buff *skb, struct nf_conn *ct)
474 {
475 	struct nf_conn_synproxy *synproxy = nfct_synproxy(ct);
476 	struct nlattr *nest_parms;
477 
478 	if (!synproxy)
479 		return 0;
480 
481 	nest_parms = nla_nest_start(skb, CTA_SYNPROXY);
482 	if (!nest_parms)
483 		goto nla_put_failure;
484 
485 	if (nla_put_be32(skb, CTA_SYNPROXY_ISN, htonl(synproxy->isn)) ||
486 	    nla_put_be32(skb, CTA_SYNPROXY_ITS, htonl(synproxy->its)) ||
487 	    nla_put_be32(skb, CTA_SYNPROXY_TSOFF, htonl(synproxy->tsoff)))
488 		goto nla_put_failure;
489 
490 	nla_nest_end(skb, nest_parms);
491 
492 	return 0;
493 
494 nla_put_failure:
495 	return -1;
496 }
497 
ctnetlink_dump_id(struct sk_buff * skb,const struct nf_conn * ct)498 static int ctnetlink_dump_id(struct sk_buff *skb, const struct nf_conn *ct)
499 {
500 	__be32 id = (__force __be32)nf_ct_get_id(ct);
501 
502 	if (nla_put_be32(skb, CTA_ID, id))
503 		goto nla_put_failure;
504 	return 0;
505 
506 nla_put_failure:
507 	return -1;
508 }
509 
ctnetlink_dump_use(struct sk_buff * skb,const struct nf_conn * ct)510 static int ctnetlink_dump_use(struct sk_buff *skb, const struct nf_conn *ct)
511 {
512 	if (nla_put_be32(skb, CTA_USE, htonl(atomic_read(&ct->ct_general.use))))
513 		goto nla_put_failure;
514 	return 0;
515 
516 nla_put_failure:
517 	return -1;
518 }
519 
520 /* all these functions access ct->ext. Caller must either hold a reference
521  * on ct or prevent its deletion by holding either the bucket spinlock or
522  * pcpu dying list lock.
523  */
ctnetlink_dump_extinfo(struct sk_buff * skb,struct nf_conn * ct,u32 type)524 static int ctnetlink_dump_extinfo(struct sk_buff *skb,
525 				  struct nf_conn *ct, u32 type)
526 {
527 	if (ctnetlink_dump_acct(skb, ct, type) < 0 ||
528 	    ctnetlink_dump_timestamp(skb, ct) < 0 ||
529 	    ctnetlink_dump_helpinfo(skb, ct) < 0 ||
530 	    ctnetlink_dump_labels(skb, ct) < 0 ||
531 	    ctnetlink_dump_ct_seq_adj(skb, ct) < 0 ||
532 	    ctnetlink_dump_ct_synproxy(skb, ct) < 0)
533 		return -1;
534 
535 	return 0;
536 }
537 
ctnetlink_dump_info(struct sk_buff * skb,struct nf_conn * ct)538 static int ctnetlink_dump_info(struct sk_buff *skb, struct nf_conn *ct)
539 {
540 	if (ctnetlink_dump_status(skb, ct) < 0 ||
541 	    ctnetlink_dump_mark(skb, ct, true) < 0 ||
542 	    ctnetlink_dump_secctx(skb, ct) < 0 ||
543 	    ctnetlink_dump_id(skb, ct) < 0 ||
544 	    ctnetlink_dump_use(skb, ct) < 0 ||
545 	    ctnetlink_dump_master(skb, ct) < 0)
546 		return -1;
547 
548 	if (!test_bit(IPS_OFFLOAD_BIT, &ct->status) &&
549 	    (ctnetlink_dump_timeout(skb, ct) < 0 ||
550 	     ctnetlink_dump_protoinfo(skb, ct) < 0))
551 		return -1;
552 
553 	return 0;
554 }
555 
556 static int
ctnetlink_fill_info(struct sk_buff * skb,u32 portid,u32 seq,u32 type,struct nf_conn * ct,bool extinfo,unsigned int flags)557 ctnetlink_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
558 		    struct nf_conn *ct, bool extinfo, unsigned int flags)
559 {
560 	const struct nf_conntrack_zone *zone;
561 	struct nlmsghdr *nlh;
562 	struct nlattr *nest_parms;
563 	unsigned int event;
564 
565 	if (portid)
566 		flags |= NLM_F_MULTI;
567 	event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK, IPCTNL_MSG_CT_NEW);
568 	nlh = nfnl_msg_put(skb, portid, seq, event, flags, nf_ct_l3num(ct),
569 			   NFNETLINK_V0, 0);
570 	if (!nlh)
571 		goto nlmsg_failure;
572 
573 	zone = nf_ct_zone(ct);
574 
575 	nest_parms = nla_nest_start(skb, CTA_TUPLE_ORIG);
576 	if (!nest_parms)
577 		goto nla_put_failure;
578 	if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
579 		goto nla_put_failure;
580 	if (ctnetlink_dump_zone_id(skb, CTA_TUPLE_ZONE, zone,
581 				   NF_CT_ZONE_DIR_ORIG) < 0)
582 		goto nla_put_failure;
583 	nla_nest_end(skb, nest_parms);
584 
585 	nest_parms = nla_nest_start(skb, CTA_TUPLE_REPLY);
586 	if (!nest_parms)
587 		goto nla_put_failure;
588 	if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_REPLY)) < 0)
589 		goto nla_put_failure;
590 	if (ctnetlink_dump_zone_id(skb, CTA_TUPLE_ZONE, zone,
591 				   NF_CT_ZONE_DIR_REPL) < 0)
592 		goto nla_put_failure;
593 	nla_nest_end(skb, nest_parms);
594 
595 	if (ctnetlink_dump_zone_id(skb, CTA_ZONE, zone,
596 				   NF_CT_DEFAULT_ZONE_DIR) < 0)
597 		goto nla_put_failure;
598 
599 	if (ctnetlink_dump_info(skb, ct) < 0)
600 		goto nla_put_failure;
601 	if (extinfo && ctnetlink_dump_extinfo(skb, ct, type) < 0)
602 		goto nla_put_failure;
603 
604 	nlmsg_end(skb, nlh);
605 	return skb->len;
606 
607 nlmsg_failure:
608 nla_put_failure:
609 	nlmsg_cancel(skb, nlh);
610 	return -1;
611 }
612 
613 static const struct nla_policy cta_ip_nla_policy[CTA_IP_MAX + 1] = {
614 	[CTA_IP_V4_SRC]	= { .type = NLA_U32 },
615 	[CTA_IP_V4_DST]	= { .type = NLA_U32 },
616 	[CTA_IP_V6_SRC]	= { .len = sizeof(__be32) * 4 },
617 	[CTA_IP_V6_DST]	= { .len = sizeof(__be32) * 4 },
618 };
619 
620 #if defined(CONFIG_NETFILTER_NETLINK_GLUE_CT) || defined(CONFIG_NF_CONNTRACK_EVENTS)
ctnetlink_proto_size(const struct nf_conn * ct)621 static size_t ctnetlink_proto_size(const struct nf_conn *ct)
622 {
623 	const struct nf_conntrack_l4proto *l4proto;
624 	size_t len, len4 = 0;
625 
626 	len = nla_policy_len(cta_ip_nla_policy, CTA_IP_MAX + 1);
627 	len *= 3u; /* ORIG, REPLY, MASTER */
628 
629 	l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
630 	len += l4proto->nlattr_size;
631 	if (l4proto->nlattr_tuple_size) {
632 		len4 = l4proto->nlattr_tuple_size();
633 		len4 *= 3u; /* ORIG, REPLY, MASTER */
634 	}
635 
636 	return len + len4;
637 }
638 #endif
639 
ctnetlink_acct_size(const struct nf_conn * ct)640 static inline size_t ctnetlink_acct_size(const struct nf_conn *ct)
641 {
642 	if (!nf_ct_ext_exist(ct, NF_CT_EXT_ACCT))
643 		return 0;
644 	return 2 * nla_total_size(0) /* CTA_COUNTERS_ORIG|REPL */
645 	       + 2 * nla_total_size_64bit(sizeof(uint64_t)) /* CTA_COUNTERS_PACKETS */
646 	       + 2 * nla_total_size_64bit(sizeof(uint64_t)) /* CTA_COUNTERS_BYTES */
647 	       ;
648 }
649 
ctnetlink_secctx_size(const struct nf_conn * ct)650 static inline int ctnetlink_secctx_size(const struct nf_conn *ct)
651 {
652 #ifdef CONFIG_NF_CONNTRACK_SECMARK
653 	int len, ret;
654 
655 	ret = security_secid_to_secctx(ct->secmark, NULL, &len);
656 	if (ret)
657 		return 0;
658 
659 	return nla_total_size(0) /* CTA_SECCTX */
660 	       + nla_total_size(sizeof(char) * len); /* CTA_SECCTX_NAME */
661 #else
662 	return 0;
663 #endif
664 }
665 
ctnetlink_timestamp_size(const struct nf_conn * ct)666 static inline size_t ctnetlink_timestamp_size(const struct nf_conn *ct)
667 {
668 #ifdef CONFIG_NF_CONNTRACK_TIMESTAMP
669 	if (!nf_ct_ext_exist(ct, NF_CT_EXT_TSTAMP))
670 		return 0;
671 	return nla_total_size(0) + 2 * nla_total_size_64bit(sizeof(uint64_t));
672 #else
673 	return 0;
674 #endif
675 }
676 
677 #ifdef CONFIG_NF_CONNTRACK_EVENTS
ctnetlink_nlmsg_size(const struct nf_conn * ct)678 static size_t ctnetlink_nlmsg_size(const struct nf_conn *ct)
679 {
680 	return NLMSG_ALIGN(sizeof(struct nfgenmsg))
681 	       + 3 * nla_total_size(0) /* CTA_TUPLE_ORIG|REPL|MASTER */
682 	       + 3 * nla_total_size(0) /* CTA_TUPLE_IP */
683 	       + 3 * nla_total_size(0) /* CTA_TUPLE_PROTO */
684 	       + 3 * nla_total_size(sizeof(u_int8_t)) /* CTA_PROTO_NUM */
685 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_ID */
686 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_STATUS */
687 	       + ctnetlink_acct_size(ct)
688 	       + ctnetlink_timestamp_size(ct)
689 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_TIMEOUT */
690 	       + nla_total_size(0) /* CTA_PROTOINFO */
691 	       + nla_total_size(0) /* CTA_HELP */
692 	       + nla_total_size(NF_CT_HELPER_NAME_LEN) /* CTA_HELP_NAME */
693 	       + ctnetlink_secctx_size(ct)
694 #if IS_ENABLED(CONFIG_NF_NAT)
695 	       + 2 * nla_total_size(0) /* CTA_NAT_SEQ_ADJ_ORIG|REPL */
696 	       + 6 * nla_total_size(sizeof(u_int32_t)) /* CTA_NAT_SEQ_OFFSET */
697 #endif
698 #ifdef CONFIG_NF_CONNTRACK_MARK
699 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_MARK */
700 #endif
701 #ifdef CONFIG_NF_CONNTRACK_ZONES
702 	       + nla_total_size(sizeof(u_int16_t)) /* CTA_ZONE|CTA_TUPLE_ZONE */
703 #endif
704 	       + ctnetlink_proto_size(ct)
705 	       + ctnetlink_label_size(ct)
706 	       ;
707 }
708 
709 static int
ctnetlink_conntrack_event(unsigned int events,struct nf_ct_event * item)710 ctnetlink_conntrack_event(unsigned int events, struct nf_ct_event *item)
711 {
712 	const struct nf_conntrack_zone *zone;
713 	struct net *net;
714 	struct nlmsghdr *nlh;
715 	struct nlattr *nest_parms;
716 	struct nf_conn *ct = item->ct;
717 	struct sk_buff *skb;
718 	unsigned int type;
719 	unsigned int flags = 0, group;
720 	int err;
721 
722 	if (events & (1 << IPCT_DESTROY)) {
723 		type = IPCTNL_MSG_CT_DELETE;
724 		group = NFNLGRP_CONNTRACK_DESTROY;
725 	} else if (events & ((1 << IPCT_NEW) | (1 << IPCT_RELATED))) {
726 		type = IPCTNL_MSG_CT_NEW;
727 		flags = NLM_F_CREATE|NLM_F_EXCL;
728 		group = NFNLGRP_CONNTRACK_NEW;
729 	} else if (events) {
730 		type = IPCTNL_MSG_CT_NEW;
731 		group = NFNLGRP_CONNTRACK_UPDATE;
732 	} else
733 		return 0;
734 
735 	net = nf_ct_net(ct);
736 	if (!item->report && !nfnetlink_has_listeners(net, group))
737 		return 0;
738 
739 	skb = nlmsg_new(ctnetlink_nlmsg_size(ct), GFP_ATOMIC);
740 	if (skb == NULL)
741 		goto errout;
742 
743 	type = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK, type);
744 	nlh = nfnl_msg_put(skb, item->portid, 0, type, flags, nf_ct_l3num(ct),
745 			   NFNETLINK_V0, 0);
746 	if (!nlh)
747 		goto nlmsg_failure;
748 
749 	zone = nf_ct_zone(ct);
750 
751 	nest_parms = nla_nest_start(skb, CTA_TUPLE_ORIG);
752 	if (!nest_parms)
753 		goto nla_put_failure;
754 	if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
755 		goto nla_put_failure;
756 	if (ctnetlink_dump_zone_id(skb, CTA_TUPLE_ZONE, zone,
757 				   NF_CT_ZONE_DIR_ORIG) < 0)
758 		goto nla_put_failure;
759 	nla_nest_end(skb, nest_parms);
760 
761 	nest_parms = nla_nest_start(skb, CTA_TUPLE_REPLY);
762 	if (!nest_parms)
763 		goto nla_put_failure;
764 	if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_REPLY)) < 0)
765 		goto nla_put_failure;
766 	if (ctnetlink_dump_zone_id(skb, CTA_TUPLE_ZONE, zone,
767 				   NF_CT_ZONE_DIR_REPL) < 0)
768 		goto nla_put_failure;
769 	nla_nest_end(skb, nest_parms);
770 
771 	if (ctnetlink_dump_zone_id(skb, CTA_ZONE, zone,
772 				   NF_CT_DEFAULT_ZONE_DIR) < 0)
773 		goto nla_put_failure;
774 
775 	if (ctnetlink_dump_id(skb, ct) < 0)
776 		goto nla_put_failure;
777 
778 	if (ctnetlink_dump_status(skb, ct) < 0)
779 		goto nla_put_failure;
780 
781 	if (events & (1 << IPCT_DESTROY)) {
782 		if (ctnetlink_dump_acct(skb, ct, type) < 0 ||
783 		    ctnetlink_dump_timestamp(skb, ct) < 0)
784 			goto nla_put_failure;
785 	} else {
786 		if (ctnetlink_dump_timeout(skb, ct) < 0)
787 			goto nla_put_failure;
788 
789 		if (events & (1 << IPCT_PROTOINFO)
790 		    && ctnetlink_dump_protoinfo(skb, ct) < 0)
791 			goto nla_put_failure;
792 
793 		if ((events & (1 << IPCT_HELPER) || nfct_help(ct))
794 		    && ctnetlink_dump_helpinfo(skb, ct) < 0)
795 			goto nla_put_failure;
796 
797 #ifdef CONFIG_NF_CONNTRACK_SECMARK
798 		if ((events & (1 << IPCT_SECMARK) || ct->secmark)
799 		    && ctnetlink_dump_secctx(skb, ct) < 0)
800 			goto nla_put_failure;
801 #endif
802 		if (events & (1 << IPCT_LABEL) &&
803 		     ctnetlink_dump_labels(skb, ct) < 0)
804 			goto nla_put_failure;
805 
806 		if (events & (1 << IPCT_RELATED) &&
807 		    ctnetlink_dump_master(skb, ct) < 0)
808 			goto nla_put_failure;
809 
810 		if (events & (1 << IPCT_SEQADJ) &&
811 		    ctnetlink_dump_ct_seq_adj(skb, ct) < 0)
812 			goto nla_put_failure;
813 
814 		if (events & (1 << IPCT_SYNPROXY) &&
815 		    ctnetlink_dump_ct_synproxy(skb, ct) < 0)
816 			goto nla_put_failure;
817 	}
818 
819 #ifdef CONFIG_NF_CONNTRACK_MARK
820 	if (ctnetlink_dump_mark(skb, ct, events & (1 << IPCT_MARK)))
821 		goto nla_put_failure;
822 #endif
823 	nlmsg_end(skb, nlh);
824 	err = nfnetlink_send(skb, net, item->portid, group, item->report,
825 			     GFP_ATOMIC);
826 	if (err == -ENOBUFS || err == -EAGAIN)
827 		return -ENOBUFS;
828 
829 	return 0;
830 
831 nla_put_failure:
832 	nlmsg_cancel(skb, nlh);
833 nlmsg_failure:
834 	kfree_skb(skb);
835 errout:
836 	if (nfnetlink_set_err(net, 0, group, -ENOBUFS) > 0)
837 		return -ENOBUFS;
838 
839 	return 0;
840 }
841 #endif /* CONFIG_NF_CONNTRACK_EVENTS */
842 
ctnetlink_done(struct netlink_callback * cb)843 static int ctnetlink_done(struct netlink_callback *cb)
844 {
845 	if (cb->args[1])
846 		nf_ct_put((struct nf_conn *)cb->args[1]);
847 	kfree(cb->data);
848 	return 0;
849 }
850 
851 struct ctnetlink_filter {
852 	u8 family;
853 
854 	u_int32_t orig_flags;
855 	u_int32_t reply_flags;
856 
857 	struct nf_conntrack_tuple orig;
858 	struct nf_conntrack_tuple reply;
859 	struct nf_conntrack_zone zone;
860 
861 	struct {
862 		u_int32_t val;
863 		u_int32_t mask;
864 	} mark;
865 };
866 
867 static const struct nla_policy cta_filter_nla_policy[CTA_FILTER_MAX + 1] = {
868 	[CTA_FILTER_ORIG_FLAGS]		= { .type = NLA_U32 },
869 	[CTA_FILTER_REPLY_FLAGS]	= { .type = NLA_U32 },
870 };
871 
ctnetlink_parse_filter(const struct nlattr * attr,struct ctnetlink_filter * filter)872 static int ctnetlink_parse_filter(const struct nlattr *attr,
873 				  struct ctnetlink_filter *filter)
874 {
875 	struct nlattr *tb[CTA_FILTER_MAX + 1];
876 	int ret = 0;
877 
878 	ret = nla_parse_nested(tb, CTA_FILTER_MAX, attr, cta_filter_nla_policy,
879 			       NULL);
880 	if (ret)
881 		return ret;
882 
883 	if (tb[CTA_FILTER_ORIG_FLAGS]) {
884 		filter->orig_flags = nla_get_u32(tb[CTA_FILTER_ORIG_FLAGS]);
885 		if (filter->orig_flags & ~CTA_FILTER_F_ALL)
886 			return -EOPNOTSUPP;
887 	}
888 
889 	if (tb[CTA_FILTER_REPLY_FLAGS]) {
890 		filter->reply_flags = nla_get_u32(tb[CTA_FILTER_REPLY_FLAGS]);
891 		if (filter->reply_flags & ~CTA_FILTER_F_ALL)
892 			return -EOPNOTSUPP;
893 	}
894 
895 	return 0;
896 }
897 
898 static int ctnetlink_parse_zone(const struct nlattr *attr,
899 				struct nf_conntrack_zone *zone);
900 static int ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],
901 					 struct nf_conntrack_tuple *tuple,
902 					 u32 type, u_int8_t l3num,
903 					 struct nf_conntrack_zone *zone,
904 					 u_int32_t flags);
905 
906 static struct ctnetlink_filter *
ctnetlink_alloc_filter(const struct nlattr * const cda[],u8 family)907 ctnetlink_alloc_filter(const struct nlattr * const cda[], u8 family)
908 {
909 	struct ctnetlink_filter *filter;
910 	int err;
911 
912 #ifndef CONFIG_NF_CONNTRACK_MARK
913 	if (cda[CTA_MARK] || cda[CTA_MARK_MASK])
914 		return ERR_PTR(-EOPNOTSUPP);
915 #endif
916 
917 	filter = kzalloc(sizeof(*filter), GFP_KERNEL);
918 	if (filter == NULL)
919 		return ERR_PTR(-ENOMEM);
920 
921 	filter->family = family;
922 
923 #ifdef CONFIG_NF_CONNTRACK_MARK
924 	if (cda[CTA_MARK]) {
925 		filter->mark.val = ntohl(nla_get_be32(cda[CTA_MARK]));
926 		if (cda[CTA_MARK_MASK])
927 			filter->mark.mask = ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
928 		else
929 			filter->mark.mask = 0xffffffff;
930 	} else if (cda[CTA_MARK_MASK]) {
931 		err = -EINVAL;
932 		goto err_filter;
933 	}
934 #endif
935 	if (!cda[CTA_FILTER])
936 		return filter;
937 
938 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &filter->zone);
939 	if (err < 0)
940 		goto err_filter;
941 
942 	err = ctnetlink_parse_filter(cda[CTA_FILTER], filter);
943 	if (err < 0)
944 		goto err_filter;
945 
946 	if (filter->orig_flags) {
947 		if (!cda[CTA_TUPLE_ORIG]) {
948 			err = -EINVAL;
949 			goto err_filter;
950 		}
951 
952 		err = ctnetlink_parse_tuple_filter(cda, &filter->orig,
953 						   CTA_TUPLE_ORIG,
954 						   filter->family,
955 						   &filter->zone,
956 						   filter->orig_flags);
957 		if (err < 0)
958 			goto err_filter;
959 	}
960 
961 	if (filter->reply_flags) {
962 		if (!cda[CTA_TUPLE_REPLY]) {
963 			err = -EINVAL;
964 			goto err_filter;
965 		}
966 
967 		err = ctnetlink_parse_tuple_filter(cda, &filter->reply,
968 						   CTA_TUPLE_REPLY,
969 						   filter->family,
970 						   &filter->zone,
971 						   filter->reply_flags);
972 		if (err < 0)
973 			goto err_filter;
974 	}
975 
976 	return filter;
977 
978 err_filter:
979 	kfree(filter);
980 
981 	return ERR_PTR(err);
982 }
983 
ctnetlink_needs_filter(u8 family,const struct nlattr * const * cda)984 static bool ctnetlink_needs_filter(u8 family, const struct nlattr * const *cda)
985 {
986 	return family || cda[CTA_MARK] || cda[CTA_FILTER];
987 }
988 
ctnetlink_start(struct netlink_callback * cb)989 static int ctnetlink_start(struct netlink_callback *cb)
990 {
991 	const struct nlattr * const *cda = cb->data;
992 	struct ctnetlink_filter *filter = NULL;
993 	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
994 	u8 family = nfmsg->nfgen_family;
995 
996 	if (ctnetlink_needs_filter(family, cda)) {
997 		filter = ctnetlink_alloc_filter(cda, family);
998 		if (IS_ERR(filter))
999 			return PTR_ERR(filter);
1000 	}
1001 
1002 	cb->data = filter;
1003 	return 0;
1004 }
1005 
ctnetlink_filter_match_tuple(struct nf_conntrack_tuple * filter_tuple,struct nf_conntrack_tuple * ct_tuple,u_int32_t flags,int family)1006 static int ctnetlink_filter_match_tuple(struct nf_conntrack_tuple *filter_tuple,
1007 					struct nf_conntrack_tuple *ct_tuple,
1008 					u_int32_t flags, int family)
1009 {
1010 	switch (family) {
1011 	case NFPROTO_IPV4:
1012 		if ((flags & CTA_FILTER_FLAG(CTA_IP_SRC)) &&
1013 		    filter_tuple->src.u3.ip != ct_tuple->src.u3.ip)
1014 			return  0;
1015 
1016 		if ((flags & CTA_FILTER_FLAG(CTA_IP_DST)) &&
1017 		    filter_tuple->dst.u3.ip != ct_tuple->dst.u3.ip)
1018 			return  0;
1019 		break;
1020 	case NFPROTO_IPV6:
1021 		if ((flags & CTA_FILTER_FLAG(CTA_IP_SRC)) &&
1022 		    !ipv6_addr_cmp(&filter_tuple->src.u3.in6,
1023 				   &ct_tuple->src.u3.in6))
1024 			return 0;
1025 
1026 		if ((flags & CTA_FILTER_FLAG(CTA_IP_DST)) &&
1027 		    !ipv6_addr_cmp(&filter_tuple->dst.u3.in6,
1028 				   &ct_tuple->dst.u3.in6))
1029 			return 0;
1030 		break;
1031 	}
1032 
1033 	if ((flags & CTA_FILTER_FLAG(CTA_PROTO_NUM)) &&
1034 	    filter_tuple->dst.protonum != ct_tuple->dst.protonum)
1035 		return 0;
1036 
1037 	switch (ct_tuple->dst.protonum) {
1038 	case IPPROTO_TCP:
1039 	case IPPROTO_UDP:
1040 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_SRC_PORT)) &&
1041 		    filter_tuple->src.u.tcp.port != ct_tuple->src.u.tcp.port)
1042 			return 0;
1043 
1044 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_DST_PORT)) &&
1045 		    filter_tuple->dst.u.tcp.port != ct_tuple->dst.u.tcp.port)
1046 			return 0;
1047 		break;
1048 	case IPPROTO_ICMP:
1049 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_TYPE)) &&
1050 		    filter_tuple->dst.u.icmp.type != ct_tuple->dst.u.icmp.type)
1051 			return 0;
1052 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_CODE)) &&
1053 		    filter_tuple->dst.u.icmp.code != ct_tuple->dst.u.icmp.code)
1054 			return 0;
1055 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_ICMP_ID)) &&
1056 		    filter_tuple->src.u.icmp.id != ct_tuple->src.u.icmp.id)
1057 			return 0;
1058 		break;
1059 	case IPPROTO_ICMPV6:
1060 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_TYPE)) &&
1061 		    filter_tuple->dst.u.icmp.type != ct_tuple->dst.u.icmp.type)
1062 			return 0;
1063 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_CODE)) &&
1064 		    filter_tuple->dst.u.icmp.code != ct_tuple->dst.u.icmp.code)
1065 			return 0;
1066 		if ((flags & CTA_FILTER_FLAG(CTA_PROTO_ICMPV6_ID)) &&
1067 		    filter_tuple->src.u.icmp.id != ct_tuple->src.u.icmp.id)
1068 			return 0;
1069 		break;
1070 	}
1071 
1072 	return 1;
1073 }
1074 
ctnetlink_filter_match(struct nf_conn * ct,void * data)1075 static int ctnetlink_filter_match(struct nf_conn *ct, void *data)
1076 {
1077 	struct ctnetlink_filter *filter = data;
1078 	struct nf_conntrack_tuple *tuple;
1079 
1080 	if (filter == NULL)
1081 		goto out;
1082 
1083 	/* Match entries of a given L3 protocol number.
1084 	 * If it is not specified, ie. l3proto == 0,
1085 	 * then match everything.
1086 	 */
1087 	if (filter->family && nf_ct_l3num(ct) != filter->family)
1088 		goto ignore_entry;
1089 
1090 	if (filter->orig_flags) {
1091 		tuple = nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL);
1092 		if (!ctnetlink_filter_match_tuple(&filter->orig, tuple,
1093 						  filter->orig_flags,
1094 						  filter->family))
1095 			goto ignore_entry;
1096 	}
1097 
1098 	if (filter->reply_flags) {
1099 		tuple = nf_ct_tuple(ct, IP_CT_DIR_REPLY);
1100 		if (!ctnetlink_filter_match_tuple(&filter->reply, tuple,
1101 						  filter->reply_flags,
1102 						  filter->family))
1103 			goto ignore_entry;
1104 	}
1105 
1106 #ifdef CONFIG_NF_CONNTRACK_MARK
1107 	if ((READ_ONCE(ct->mark) & filter->mark.mask) != filter->mark.val)
1108 		goto ignore_entry;
1109 #endif
1110 
1111 out:
1112 	return 1;
1113 
1114 ignore_entry:
1115 	return 0;
1116 }
1117 
1118 static int
ctnetlink_dump_table(struct sk_buff * skb,struct netlink_callback * cb)1119 ctnetlink_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
1120 {
1121 	unsigned int flags = cb->data ? NLM_F_DUMP_FILTERED : 0;
1122 	struct net *net = sock_net(skb->sk);
1123 	struct nf_conn *ct, *last;
1124 	struct nf_conntrack_tuple_hash *h;
1125 	struct hlist_nulls_node *n;
1126 	struct nf_conn *nf_ct_evict[8];
1127 	int res, i;
1128 	spinlock_t *lockp;
1129 
1130 	last = (struct nf_conn *)cb->args[1];
1131 	i = 0;
1132 
1133 	local_bh_disable();
1134 	for (; cb->args[0] < nf_conntrack_htable_size; cb->args[0]++) {
1135 restart:
1136 		while (i) {
1137 			i--;
1138 			if (nf_ct_should_gc(nf_ct_evict[i]))
1139 				nf_ct_kill(nf_ct_evict[i]);
1140 			nf_ct_put(nf_ct_evict[i]);
1141 		}
1142 
1143 		lockp = &nf_conntrack_locks[cb->args[0] % CONNTRACK_LOCKS];
1144 		nf_conntrack_lock(lockp);
1145 		if (cb->args[0] >= nf_conntrack_htable_size) {
1146 			spin_unlock(lockp);
1147 			goto out;
1148 		}
1149 		hlist_nulls_for_each_entry(h, n, &nf_conntrack_hash[cb->args[0]],
1150 					   hnnode) {
1151 			if (NF_CT_DIRECTION(h) != IP_CT_DIR_ORIGINAL)
1152 				continue;
1153 			ct = nf_ct_tuplehash_to_ctrack(h);
1154 			if (nf_ct_is_expired(ct)) {
1155 				if (i < ARRAY_SIZE(nf_ct_evict) &&
1156 				    atomic_inc_not_zero(&ct->ct_general.use))
1157 					nf_ct_evict[i++] = ct;
1158 				continue;
1159 			}
1160 
1161 			if (!net_eq(net, nf_ct_net(ct)))
1162 				continue;
1163 
1164 			if (cb->args[1]) {
1165 				if (ct != last)
1166 					continue;
1167 				cb->args[1] = 0;
1168 			}
1169 			if (!ctnetlink_filter_match(ct, cb->data))
1170 				continue;
1171 
1172 			res =
1173 			ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid,
1174 					    cb->nlh->nlmsg_seq,
1175 					    NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
1176 					    ct, true, flags);
1177 			if (res < 0) {
1178 				nf_conntrack_get(&ct->ct_general);
1179 				cb->args[1] = (unsigned long)ct;
1180 				spin_unlock(lockp);
1181 				goto out;
1182 			}
1183 		}
1184 		spin_unlock(lockp);
1185 		if (cb->args[1]) {
1186 			cb->args[1] = 0;
1187 			goto restart;
1188 		}
1189 	}
1190 out:
1191 	local_bh_enable();
1192 	if (last) {
1193 		/* nf ct hash resize happened, now clear the leftover. */
1194 		if ((struct nf_conn *)cb->args[1] == last)
1195 			cb->args[1] = 0;
1196 
1197 		nf_ct_put(last);
1198 	}
1199 
1200 	while (i) {
1201 		i--;
1202 		if (nf_ct_should_gc(nf_ct_evict[i]))
1203 			nf_ct_kill(nf_ct_evict[i]);
1204 		nf_ct_put(nf_ct_evict[i]);
1205 	}
1206 
1207 	return skb->len;
1208 }
1209 
ipv4_nlattr_to_tuple(struct nlattr * tb[],struct nf_conntrack_tuple * t,u_int32_t flags)1210 static int ipv4_nlattr_to_tuple(struct nlattr *tb[],
1211 				struct nf_conntrack_tuple *t,
1212 				u_int32_t flags)
1213 {
1214 	if (flags & CTA_FILTER_FLAG(CTA_IP_SRC)) {
1215 		if (!tb[CTA_IP_V4_SRC])
1216 			return -EINVAL;
1217 
1218 		t->src.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_SRC]);
1219 	}
1220 
1221 	if (flags & CTA_FILTER_FLAG(CTA_IP_DST)) {
1222 		if (!tb[CTA_IP_V4_DST])
1223 			return -EINVAL;
1224 
1225 		t->dst.u3.ip = nla_get_in_addr(tb[CTA_IP_V4_DST]);
1226 	}
1227 
1228 	return 0;
1229 }
1230 
ipv6_nlattr_to_tuple(struct nlattr * tb[],struct nf_conntrack_tuple * t,u_int32_t flags)1231 static int ipv6_nlattr_to_tuple(struct nlattr *tb[],
1232 				struct nf_conntrack_tuple *t,
1233 				u_int32_t flags)
1234 {
1235 	if (flags & CTA_FILTER_FLAG(CTA_IP_SRC)) {
1236 		if (!tb[CTA_IP_V6_SRC])
1237 			return -EINVAL;
1238 
1239 		t->src.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_SRC]);
1240 	}
1241 
1242 	if (flags & CTA_FILTER_FLAG(CTA_IP_DST)) {
1243 		if (!tb[CTA_IP_V6_DST])
1244 			return -EINVAL;
1245 
1246 		t->dst.u3.in6 = nla_get_in6_addr(tb[CTA_IP_V6_DST]);
1247 	}
1248 
1249 	return 0;
1250 }
1251 
ctnetlink_parse_tuple_ip(struct nlattr * attr,struct nf_conntrack_tuple * tuple,u_int32_t flags)1252 static int ctnetlink_parse_tuple_ip(struct nlattr *attr,
1253 				    struct nf_conntrack_tuple *tuple,
1254 				    u_int32_t flags)
1255 {
1256 	struct nlattr *tb[CTA_IP_MAX+1];
1257 	int ret = 0;
1258 
1259 	ret = nla_parse_nested_deprecated(tb, CTA_IP_MAX, attr, NULL, NULL);
1260 	if (ret < 0)
1261 		return ret;
1262 
1263 	ret = nla_validate_nested_deprecated(attr, CTA_IP_MAX,
1264 					     cta_ip_nla_policy, NULL);
1265 	if (ret)
1266 		return ret;
1267 
1268 	switch (tuple->src.l3num) {
1269 	case NFPROTO_IPV4:
1270 		ret = ipv4_nlattr_to_tuple(tb, tuple, flags);
1271 		break;
1272 	case NFPROTO_IPV6:
1273 		ret = ipv6_nlattr_to_tuple(tb, tuple, flags);
1274 		break;
1275 	}
1276 
1277 	return ret;
1278 }
1279 
1280 static const struct nla_policy proto_nla_policy[CTA_PROTO_MAX+1] = {
1281 	[CTA_PROTO_NUM]	= { .type = NLA_U8 },
1282 };
1283 
ctnetlink_parse_tuple_proto(struct nlattr * attr,struct nf_conntrack_tuple * tuple,u_int32_t flags)1284 static int ctnetlink_parse_tuple_proto(struct nlattr *attr,
1285 				       struct nf_conntrack_tuple *tuple,
1286 				       u_int32_t flags)
1287 {
1288 	const struct nf_conntrack_l4proto *l4proto;
1289 	struct nlattr *tb[CTA_PROTO_MAX+1];
1290 	int ret = 0;
1291 
1292 	ret = nla_parse_nested_deprecated(tb, CTA_PROTO_MAX, attr,
1293 					  proto_nla_policy, NULL);
1294 	if (ret < 0)
1295 		return ret;
1296 
1297 	if (!(flags & CTA_FILTER_FLAG(CTA_PROTO_NUM)))
1298 		return 0;
1299 
1300 	if (!tb[CTA_PROTO_NUM])
1301 		return -EINVAL;
1302 
1303 	tuple->dst.protonum = nla_get_u8(tb[CTA_PROTO_NUM]);
1304 
1305 	rcu_read_lock();
1306 	l4proto = nf_ct_l4proto_find(tuple->dst.protonum);
1307 
1308 	if (likely(l4proto->nlattr_to_tuple)) {
1309 		ret = nla_validate_nested_deprecated(attr, CTA_PROTO_MAX,
1310 						     l4proto->nla_policy,
1311 						     NULL);
1312 		if (ret == 0)
1313 			ret = l4proto->nlattr_to_tuple(tb, tuple, flags);
1314 	}
1315 
1316 	rcu_read_unlock();
1317 
1318 	return ret;
1319 }
1320 
1321 static int
ctnetlink_parse_zone(const struct nlattr * attr,struct nf_conntrack_zone * zone)1322 ctnetlink_parse_zone(const struct nlattr *attr,
1323 		     struct nf_conntrack_zone *zone)
1324 {
1325 	nf_ct_zone_init(zone, NF_CT_DEFAULT_ZONE_ID,
1326 			NF_CT_DEFAULT_ZONE_DIR, 0);
1327 #ifdef CONFIG_NF_CONNTRACK_ZONES
1328 	if (attr)
1329 		zone->id = ntohs(nla_get_be16(attr));
1330 #else
1331 	if (attr)
1332 		return -EOPNOTSUPP;
1333 #endif
1334 	return 0;
1335 }
1336 
1337 static int
ctnetlink_parse_tuple_zone(struct nlattr * attr,enum ctattr_type type,struct nf_conntrack_zone * zone)1338 ctnetlink_parse_tuple_zone(struct nlattr *attr, enum ctattr_type type,
1339 			   struct nf_conntrack_zone *zone)
1340 {
1341 	int ret;
1342 
1343 	if (zone->id != NF_CT_DEFAULT_ZONE_ID)
1344 		return -EINVAL;
1345 
1346 	ret = ctnetlink_parse_zone(attr, zone);
1347 	if (ret < 0)
1348 		return ret;
1349 
1350 	if (type == CTA_TUPLE_REPLY)
1351 		zone->dir = NF_CT_ZONE_DIR_REPL;
1352 	else
1353 		zone->dir = NF_CT_ZONE_DIR_ORIG;
1354 
1355 	return 0;
1356 }
1357 
1358 static const struct nla_policy tuple_nla_policy[CTA_TUPLE_MAX+1] = {
1359 	[CTA_TUPLE_IP]		= { .type = NLA_NESTED },
1360 	[CTA_TUPLE_PROTO]	= { .type = NLA_NESTED },
1361 	[CTA_TUPLE_ZONE]	= { .type = NLA_U16 },
1362 };
1363 
1364 #define CTA_FILTER_F_ALL_CTA_PROTO \
1365   (CTA_FILTER_F_CTA_PROTO_SRC_PORT | \
1366    CTA_FILTER_F_CTA_PROTO_DST_PORT | \
1367    CTA_FILTER_F_CTA_PROTO_ICMP_TYPE | \
1368    CTA_FILTER_F_CTA_PROTO_ICMP_CODE | \
1369    CTA_FILTER_F_CTA_PROTO_ICMP_ID | \
1370    CTA_FILTER_F_CTA_PROTO_ICMPV6_TYPE | \
1371    CTA_FILTER_F_CTA_PROTO_ICMPV6_CODE | \
1372    CTA_FILTER_F_CTA_PROTO_ICMPV6_ID)
1373 
1374 static int
ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],struct nf_conntrack_tuple * tuple,u32 type,u_int8_t l3num,struct nf_conntrack_zone * zone,u_int32_t flags)1375 ctnetlink_parse_tuple_filter(const struct nlattr * const cda[],
1376 			      struct nf_conntrack_tuple *tuple, u32 type,
1377 			      u_int8_t l3num, struct nf_conntrack_zone *zone,
1378 			      u_int32_t flags)
1379 {
1380 	struct nlattr *tb[CTA_TUPLE_MAX+1];
1381 	int err;
1382 
1383 	memset(tuple, 0, sizeof(*tuple));
1384 
1385 	err = nla_parse_nested_deprecated(tb, CTA_TUPLE_MAX, cda[type],
1386 					  tuple_nla_policy, NULL);
1387 	if (err < 0)
1388 		return err;
1389 
1390 	if (l3num != NFPROTO_IPV4 && l3num != NFPROTO_IPV6)
1391 		return -EOPNOTSUPP;
1392 	tuple->src.l3num = l3num;
1393 
1394 	if (flags & CTA_FILTER_FLAG(CTA_IP_DST) ||
1395 	    flags & CTA_FILTER_FLAG(CTA_IP_SRC)) {
1396 		if (!tb[CTA_TUPLE_IP])
1397 			return -EINVAL;
1398 
1399 		err = ctnetlink_parse_tuple_ip(tb[CTA_TUPLE_IP], tuple, flags);
1400 		if (err < 0)
1401 			return err;
1402 	}
1403 
1404 	if (flags & CTA_FILTER_FLAG(CTA_PROTO_NUM)) {
1405 		if (!tb[CTA_TUPLE_PROTO])
1406 			return -EINVAL;
1407 
1408 		err = ctnetlink_parse_tuple_proto(tb[CTA_TUPLE_PROTO], tuple, flags);
1409 		if (err < 0)
1410 			return err;
1411 	} else if (flags & CTA_FILTER_FLAG(ALL_CTA_PROTO)) {
1412 		/* Can't manage proto flags without a protonum  */
1413 		return -EINVAL;
1414 	}
1415 
1416 	if ((flags & CTA_FILTER_FLAG(CTA_TUPLE_ZONE)) && tb[CTA_TUPLE_ZONE]) {
1417 		if (!zone)
1418 			return -EINVAL;
1419 
1420 		err = ctnetlink_parse_tuple_zone(tb[CTA_TUPLE_ZONE],
1421 						 type, zone);
1422 		if (err < 0)
1423 			return err;
1424 	}
1425 
1426 	/* orig and expect tuples get DIR_ORIGINAL */
1427 	if (type == CTA_TUPLE_REPLY)
1428 		tuple->dst.dir = IP_CT_DIR_REPLY;
1429 	else
1430 		tuple->dst.dir = IP_CT_DIR_ORIGINAL;
1431 
1432 	return 0;
1433 }
1434 
1435 static int
ctnetlink_parse_tuple(const struct nlattr * const cda[],struct nf_conntrack_tuple * tuple,u32 type,u_int8_t l3num,struct nf_conntrack_zone * zone)1436 ctnetlink_parse_tuple(const struct nlattr * const cda[],
1437 		      struct nf_conntrack_tuple *tuple, u32 type,
1438 		      u_int8_t l3num, struct nf_conntrack_zone *zone)
1439 {
1440 	return ctnetlink_parse_tuple_filter(cda, tuple, type, l3num, zone,
1441 					    CTA_FILTER_FLAG(ALL));
1442 }
1443 
1444 static const struct nla_policy help_nla_policy[CTA_HELP_MAX+1] = {
1445 	[CTA_HELP_NAME]		= { .type = NLA_NUL_STRING,
1446 				    .len = NF_CT_HELPER_NAME_LEN - 1 },
1447 };
1448 
ctnetlink_parse_help(const struct nlattr * attr,char ** helper_name,struct nlattr ** helpinfo)1449 static int ctnetlink_parse_help(const struct nlattr *attr, char **helper_name,
1450 				struct nlattr **helpinfo)
1451 {
1452 	int err;
1453 	struct nlattr *tb[CTA_HELP_MAX+1];
1454 
1455 	err = nla_parse_nested_deprecated(tb, CTA_HELP_MAX, attr,
1456 					  help_nla_policy, NULL);
1457 	if (err < 0)
1458 		return err;
1459 
1460 	if (!tb[CTA_HELP_NAME])
1461 		return -EINVAL;
1462 
1463 	*helper_name = nla_data(tb[CTA_HELP_NAME]);
1464 
1465 	if (tb[CTA_HELP_INFO])
1466 		*helpinfo = tb[CTA_HELP_INFO];
1467 
1468 	return 0;
1469 }
1470 
1471 static const struct nla_policy ct_nla_policy[CTA_MAX+1] = {
1472 	[CTA_TUPLE_ORIG]	= { .type = NLA_NESTED },
1473 	[CTA_TUPLE_REPLY]	= { .type = NLA_NESTED },
1474 	[CTA_STATUS] 		= { .type = NLA_U32 },
1475 	[CTA_PROTOINFO]		= { .type = NLA_NESTED },
1476 	[CTA_HELP]		= { .type = NLA_NESTED },
1477 	[CTA_NAT_SRC]		= { .type = NLA_NESTED },
1478 	[CTA_TIMEOUT] 		= { .type = NLA_U32 },
1479 	[CTA_MARK]		= { .type = NLA_U32 },
1480 	[CTA_ID]		= { .type = NLA_U32 },
1481 	[CTA_NAT_DST]		= { .type = NLA_NESTED },
1482 	[CTA_TUPLE_MASTER]	= { .type = NLA_NESTED },
1483 	[CTA_NAT_SEQ_ADJ_ORIG]  = { .type = NLA_NESTED },
1484 	[CTA_NAT_SEQ_ADJ_REPLY] = { .type = NLA_NESTED },
1485 	[CTA_ZONE]		= { .type = NLA_U16 },
1486 	[CTA_MARK_MASK]		= { .type = NLA_U32 },
1487 	[CTA_LABELS]		= { .type = NLA_BINARY,
1488 				    .len = NF_CT_LABELS_MAX_SIZE },
1489 	[CTA_LABELS_MASK]	= { .type = NLA_BINARY,
1490 				    .len = NF_CT_LABELS_MAX_SIZE },
1491 	[CTA_FILTER]		= { .type = NLA_NESTED },
1492 };
1493 
ctnetlink_flush_iterate(struct nf_conn * ct,void * data)1494 static int ctnetlink_flush_iterate(struct nf_conn *ct, void *data)
1495 {
1496 	return ctnetlink_filter_match(ct, data);
1497 }
1498 
ctnetlink_flush_conntrack(struct net * net,const struct nlattr * const cda[],u32 portid,int report,u8 family)1499 static int ctnetlink_flush_conntrack(struct net *net,
1500 				     const struct nlattr * const cda[],
1501 				     u32 portid, int report, u8 family)
1502 {
1503 	struct ctnetlink_filter *filter = NULL;
1504 
1505 	if (ctnetlink_needs_filter(family, cda)) {
1506 		if (cda[CTA_FILTER])
1507 			return -EOPNOTSUPP;
1508 
1509 		filter = ctnetlink_alloc_filter(cda, family);
1510 		if (IS_ERR(filter))
1511 			return PTR_ERR(filter);
1512 	}
1513 
1514 	nf_ct_iterate_cleanup_net(net, ctnetlink_flush_iterate, filter,
1515 				  portid, report);
1516 	kfree(filter);
1517 
1518 	return 0;
1519 }
1520 
ctnetlink_del_conntrack(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)1521 static int ctnetlink_del_conntrack(struct net *net, struct sock *ctnl,
1522 				   struct sk_buff *skb,
1523 				   const struct nlmsghdr *nlh,
1524 				   const struct nlattr * const cda[],
1525 				   struct netlink_ext_ack *extack)
1526 {
1527 	struct nf_conntrack_tuple_hash *h;
1528 	struct nf_conntrack_tuple tuple;
1529 	struct nf_conn *ct;
1530 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1531 	struct nf_conntrack_zone zone;
1532 	int err;
1533 
1534 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
1535 	if (err < 0)
1536 		return err;
1537 
1538 	if (cda[CTA_TUPLE_ORIG])
1539 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG,
1540 					    nfmsg->nfgen_family, &zone);
1541 	else if (cda[CTA_TUPLE_REPLY])
1542 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY,
1543 					    nfmsg->nfgen_family, &zone);
1544 	else {
1545 		u_int8_t u3 = nfmsg->version ? nfmsg->nfgen_family : AF_UNSPEC;
1546 
1547 		return ctnetlink_flush_conntrack(net, cda,
1548 						 NETLINK_CB(skb).portid,
1549 						 nlmsg_report(nlh), u3);
1550 	}
1551 
1552 	if (err < 0)
1553 		return err;
1554 
1555 	h = nf_conntrack_find_get(net, &zone, &tuple);
1556 	if (!h)
1557 		return -ENOENT;
1558 
1559 	ct = nf_ct_tuplehash_to_ctrack(h);
1560 
1561 	if (cda[CTA_ID]) {
1562 		__be32 id = nla_get_be32(cda[CTA_ID]);
1563 
1564 		if (id != (__force __be32)nf_ct_get_id(ct)) {
1565 			nf_ct_put(ct);
1566 			return -ENOENT;
1567 		}
1568 	}
1569 
1570 	nf_ct_delete(ct, NETLINK_CB(skb).portid, nlmsg_report(nlh));
1571 	nf_ct_put(ct);
1572 
1573 	return 0;
1574 }
1575 
ctnetlink_get_conntrack(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)1576 static int ctnetlink_get_conntrack(struct net *net, struct sock *ctnl,
1577 				   struct sk_buff *skb,
1578 				   const struct nlmsghdr *nlh,
1579 				   const struct nlattr * const cda[],
1580 				   struct netlink_ext_ack *extack)
1581 {
1582 	struct nf_conntrack_tuple_hash *h;
1583 	struct nf_conntrack_tuple tuple;
1584 	struct nf_conn *ct;
1585 	struct sk_buff *skb2 = NULL;
1586 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
1587 	u_int8_t u3 = nfmsg->nfgen_family;
1588 	struct nf_conntrack_zone zone;
1589 	int err;
1590 
1591 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
1592 		struct netlink_dump_control c = {
1593 			.start = ctnetlink_start,
1594 			.dump = ctnetlink_dump_table,
1595 			.done = ctnetlink_done,
1596 			.data = (void *)cda,
1597 		};
1598 
1599 		return netlink_dump_start(ctnl, skb, nlh, &c);
1600 	}
1601 
1602 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
1603 	if (err < 0)
1604 		return err;
1605 
1606 	if (cda[CTA_TUPLE_ORIG])
1607 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_ORIG,
1608 					    u3, &zone);
1609 	else if (cda[CTA_TUPLE_REPLY])
1610 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_TUPLE_REPLY,
1611 					    u3, &zone);
1612 	else
1613 		return -EINVAL;
1614 
1615 	if (err < 0)
1616 		return err;
1617 
1618 	h = nf_conntrack_find_get(net, &zone, &tuple);
1619 	if (!h)
1620 		return -ENOENT;
1621 
1622 	ct = nf_ct_tuplehash_to_ctrack(h);
1623 
1624 	err = -ENOMEM;
1625 	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1626 	if (skb2 == NULL) {
1627 		nf_ct_put(ct);
1628 		return -ENOMEM;
1629 	}
1630 
1631 	err = ctnetlink_fill_info(skb2, NETLINK_CB(skb).portid, nlh->nlmsg_seq,
1632 				  NFNL_MSG_TYPE(nlh->nlmsg_type), ct, true, 0);
1633 	nf_ct_put(ct);
1634 	if (err <= 0)
1635 		goto free;
1636 
1637 	err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
1638 	if (err < 0)
1639 		goto out;
1640 
1641 	return 0;
1642 
1643 free:
1644 	kfree_skb(skb2);
1645 out:
1646 	/* this avoids a loop in nfnetlink. */
1647 	return err == -EAGAIN ? -ENOBUFS : err;
1648 }
1649 
ctnetlink_done_list(struct netlink_callback * cb)1650 static int ctnetlink_done_list(struct netlink_callback *cb)
1651 {
1652 	if (cb->args[1])
1653 		nf_ct_put((struct nf_conn *)cb->args[1]);
1654 	return 0;
1655 }
1656 
1657 static int
ctnetlink_dump_list(struct sk_buff * skb,struct netlink_callback * cb,bool dying)1658 ctnetlink_dump_list(struct sk_buff *skb, struct netlink_callback *cb, bool dying)
1659 {
1660 	struct nf_conn *ct, *last;
1661 	struct nf_conntrack_tuple_hash *h;
1662 	struct hlist_nulls_node *n;
1663 	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
1664 	u_int8_t l3proto = nfmsg->nfgen_family;
1665 	int res;
1666 	int cpu;
1667 	struct hlist_nulls_head *list;
1668 	struct net *net = sock_net(skb->sk);
1669 
1670 	if (cb->args[2])
1671 		return 0;
1672 
1673 	last = (struct nf_conn *)cb->args[1];
1674 
1675 	for (cpu = cb->args[0]; cpu < nr_cpu_ids; cpu++) {
1676 		struct ct_pcpu *pcpu;
1677 
1678 		if (!cpu_possible(cpu))
1679 			continue;
1680 
1681 		pcpu = per_cpu_ptr(net->ct.pcpu_lists, cpu);
1682 		spin_lock_bh(&pcpu->lock);
1683 		list = dying ? &pcpu->dying : &pcpu->unconfirmed;
1684 restart:
1685 		hlist_nulls_for_each_entry(h, n, list, hnnode) {
1686 			ct = nf_ct_tuplehash_to_ctrack(h);
1687 			if (l3proto && nf_ct_l3num(ct) != l3proto)
1688 				continue;
1689 			if (cb->args[1]) {
1690 				if (ct != last)
1691 					continue;
1692 				cb->args[1] = 0;
1693 			}
1694 
1695 			/* We can't dump extension info for the unconfirmed
1696 			 * list because unconfirmed conntracks can have
1697 			 * ct->ext reallocated (and thus freed).
1698 			 *
1699 			 * In the dying list case ct->ext can't be free'd
1700 			 * until after we drop pcpu->lock.
1701 			 */
1702 			res = ctnetlink_fill_info(skb, NETLINK_CB(cb->skb).portid,
1703 						  cb->nlh->nlmsg_seq,
1704 						  NFNL_MSG_TYPE(cb->nlh->nlmsg_type),
1705 						  ct, dying ? true : false, 0);
1706 			if (res < 0) {
1707 				if (!atomic_inc_not_zero(&ct->ct_general.use))
1708 					continue;
1709 				cb->args[0] = cpu;
1710 				cb->args[1] = (unsigned long)ct;
1711 				spin_unlock_bh(&pcpu->lock);
1712 				goto out;
1713 			}
1714 		}
1715 		if (cb->args[1]) {
1716 			cb->args[1] = 0;
1717 			goto restart;
1718 		}
1719 		spin_unlock_bh(&pcpu->lock);
1720 	}
1721 	cb->args[2] = 1;
1722 out:
1723 	if (last)
1724 		nf_ct_put(last);
1725 
1726 	return skb->len;
1727 }
1728 
1729 static int
ctnetlink_dump_dying(struct sk_buff * skb,struct netlink_callback * cb)1730 ctnetlink_dump_dying(struct sk_buff *skb, struct netlink_callback *cb)
1731 {
1732 	return ctnetlink_dump_list(skb, cb, true);
1733 }
1734 
ctnetlink_get_ct_dying(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)1735 static int ctnetlink_get_ct_dying(struct net *net, struct sock *ctnl,
1736 				  struct sk_buff *skb,
1737 				  const struct nlmsghdr *nlh,
1738 				  const struct nlattr * const cda[],
1739 				  struct netlink_ext_ack *extack)
1740 {
1741 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
1742 		struct netlink_dump_control c = {
1743 			.dump = ctnetlink_dump_dying,
1744 			.done = ctnetlink_done_list,
1745 		};
1746 		return netlink_dump_start(ctnl, skb, nlh, &c);
1747 	}
1748 
1749 	return -EOPNOTSUPP;
1750 }
1751 
1752 static int
ctnetlink_dump_unconfirmed(struct sk_buff * skb,struct netlink_callback * cb)1753 ctnetlink_dump_unconfirmed(struct sk_buff *skb, struct netlink_callback *cb)
1754 {
1755 	return ctnetlink_dump_list(skb, cb, false);
1756 }
1757 
ctnetlink_get_ct_unconfirmed(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)1758 static int ctnetlink_get_ct_unconfirmed(struct net *net, struct sock *ctnl,
1759 					struct sk_buff *skb,
1760 					const struct nlmsghdr *nlh,
1761 					const struct nlattr * const cda[],
1762 					struct netlink_ext_ack *extack)
1763 {
1764 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
1765 		struct netlink_dump_control c = {
1766 			.dump = ctnetlink_dump_unconfirmed,
1767 			.done = ctnetlink_done_list,
1768 		};
1769 		return netlink_dump_start(ctnl, skb, nlh, &c);
1770 	}
1771 
1772 	return -EOPNOTSUPP;
1773 }
1774 
1775 #if IS_ENABLED(CONFIG_NF_NAT)
1776 static int
ctnetlink_parse_nat_setup(struct nf_conn * ct,enum nf_nat_manip_type manip,const struct nlattr * attr)1777 ctnetlink_parse_nat_setup(struct nf_conn *ct,
1778 			  enum nf_nat_manip_type manip,
1779 			  const struct nlattr *attr)
1780 	__must_hold(RCU)
1781 {
1782 	struct nf_nat_hook *nat_hook;
1783 	int err;
1784 
1785 	nat_hook = rcu_dereference(nf_nat_hook);
1786 	if (!nat_hook) {
1787 #ifdef CONFIG_MODULES
1788 		rcu_read_unlock();
1789 		nfnl_unlock(NFNL_SUBSYS_CTNETLINK);
1790 		if (request_module("nf-nat") < 0) {
1791 			nfnl_lock(NFNL_SUBSYS_CTNETLINK);
1792 			rcu_read_lock();
1793 			return -EOPNOTSUPP;
1794 		}
1795 		nfnl_lock(NFNL_SUBSYS_CTNETLINK);
1796 		rcu_read_lock();
1797 		nat_hook = rcu_dereference(nf_nat_hook);
1798 		if (nat_hook)
1799 			return -EAGAIN;
1800 #endif
1801 		return -EOPNOTSUPP;
1802 	}
1803 
1804 	err = nat_hook->parse_nat_setup(ct, manip, attr);
1805 	if (err == -EAGAIN) {
1806 #ifdef CONFIG_MODULES
1807 		rcu_read_unlock();
1808 		nfnl_unlock(NFNL_SUBSYS_CTNETLINK);
1809 		if (request_module("nf-nat-%u", nf_ct_l3num(ct)) < 0) {
1810 			nfnl_lock(NFNL_SUBSYS_CTNETLINK);
1811 			rcu_read_lock();
1812 			return -EOPNOTSUPP;
1813 		}
1814 		nfnl_lock(NFNL_SUBSYS_CTNETLINK);
1815 		rcu_read_lock();
1816 #else
1817 		err = -EOPNOTSUPP;
1818 #endif
1819 	}
1820 	return err;
1821 }
1822 #endif
1823 
1824 static void
__ctnetlink_change_status(struct nf_conn * ct,unsigned long on,unsigned long off)1825 __ctnetlink_change_status(struct nf_conn *ct, unsigned long on,
1826 			  unsigned long off)
1827 {
1828 	unsigned int bit;
1829 
1830 	/* Ignore these unchangable bits */
1831 	on &= ~IPS_UNCHANGEABLE_MASK;
1832 	off &= ~IPS_UNCHANGEABLE_MASK;
1833 
1834 	for (bit = 0; bit < __IPS_MAX_BIT; bit++) {
1835 		if (on & (1 << bit))
1836 			set_bit(bit, &ct->status);
1837 		else if (off & (1 << bit))
1838 			clear_bit(bit, &ct->status);
1839 	}
1840 }
1841 
1842 static int
ctnetlink_change_status(struct nf_conn * ct,const struct nlattr * const cda[])1843 ctnetlink_change_status(struct nf_conn *ct, const struct nlattr * const cda[])
1844 {
1845 	unsigned long d;
1846 	unsigned int status = ntohl(nla_get_be32(cda[CTA_STATUS]));
1847 	d = ct->status ^ status;
1848 
1849 	if (d & (IPS_EXPECTED|IPS_CONFIRMED|IPS_DYING))
1850 		/* unchangeable */
1851 		return -EBUSY;
1852 
1853 	if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY))
1854 		/* SEEN_REPLY bit can only be set */
1855 		return -EBUSY;
1856 
1857 	if (d & IPS_ASSURED && !(status & IPS_ASSURED))
1858 		/* ASSURED bit can only be set */
1859 		return -EBUSY;
1860 
1861 	__ctnetlink_change_status(ct, status, 0);
1862 	return 0;
1863 }
1864 
1865 static int
ctnetlink_setup_nat(struct nf_conn * ct,const struct nlattr * const cda[])1866 ctnetlink_setup_nat(struct nf_conn *ct, const struct nlattr * const cda[])
1867 {
1868 #if IS_ENABLED(CONFIG_NF_NAT)
1869 	int ret;
1870 
1871 	if (!cda[CTA_NAT_DST] && !cda[CTA_NAT_SRC])
1872 		return 0;
1873 
1874 	ret = ctnetlink_parse_nat_setup(ct, NF_NAT_MANIP_DST,
1875 					cda[CTA_NAT_DST]);
1876 	if (ret < 0)
1877 		return ret;
1878 
1879 	return ctnetlink_parse_nat_setup(ct, NF_NAT_MANIP_SRC,
1880 					 cda[CTA_NAT_SRC]);
1881 #else
1882 	if (!cda[CTA_NAT_DST] && !cda[CTA_NAT_SRC])
1883 		return 0;
1884 	return -EOPNOTSUPP;
1885 #endif
1886 }
1887 
ctnetlink_change_helper(struct nf_conn * ct,const struct nlattr * const cda[])1888 static int ctnetlink_change_helper(struct nf_conn *ct,
1889 				   const struct nlattr * const cda[])
1890 {
1891 	struct nf_conntrack_helper *helper;
1892 	struct nf_conn_help *help = nfct_help(ct);
1893 	char *helpname = NULL;
1894 	struct nlattr *helpinfo = NULL;
1895 	int err;
1896 
1897 	err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
1898 	if (err < 0)
1899 		return err;
1900 
1901 	/* don't change helper of sibling connections */
1902 	if (ct->master) {
1903 		/* If we try to change the helper to the same thing twice,
1904 		 * treat the second attempt as a no-op instead of returning
1905 		 * an error.
1906 		 */
1907 		err = -EBUSY;
1908 		if (help) {
1909 			rcu_read_lock();
1910 			helper = rcu_dereference(help->helper);
1911 			if (helper && !strcmp(helper->name, helpname))
1912 				err = 0;
1913 			rcu_read_unlock();
1914 		}
1915 
1916 		return err;
1917 	}
1918 
1919 	if (!strcmp(helpname, "")) {
1920 		if (help && help->helper) {
1921 			/* we had a helper before ... */
1922 			nf_ct_remove_expectations(ct);
1923 			RCU_INIT_POINTER(help->helper, NULL);
1924 		}
1925 
1926 		return 0;
1927 	}
1928 
1929 	rcu_read_lock();
1930 	helper = __nf_conntrack_helper_find(helpname, nf_ct_l3num(ct),
1931 					    nf_ct_protonum(ct));
1932 	if (helper == NULL) {
1933 		rcu_read_unlock();
1934 		return -EOPNOTSUPP;
1935 	}
1936 
1937 	if (help) {
1938 		if (help->helper == helper) {
1939 			/* update private helper data if allowed. */
1940 			if (helper->from_nlattr)
1941 				helper->from_nlattr(helpinfo, ct);
1942 			err = 0;
1943 		} else
1944 			err = -EBUSY;
1945 	} else {
1946 		/* we cannot set a helper for an existing conntrack */
1947 		err = -EOPNOTSUPP;
1948 	}
1949 
1950 	rcu_read_unlock();
1951 	return err;
1952 }
1953 
ctnetlink_change_timeout(struct nf_conn * ct,const struct nlattr * const cda[])1954 static int ctnetlink_change_timeout(struct nf_conn *ct,
1955 				    const struct nlattr * const cda[])
1956 {
1957 	u64 timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
1958 
1959 	if (timeout > INT_MAX)
1960 		timeout = INT_MAX;
1961 	WRITE_ONCE(ct->timeout, nfct_time_stamp + (u32)timeout);
1962 
1963 	if (test_bit(IPS_DYING_BIT, &ct->status))
1964 		return -ETIME;
1965 
1966 	return 0;
1967 }
1968 
1969 #if defined(CONFIG_NF_CONNTRACK_MARK)
ctnetlink_change_mark(struct nf_conn * ct,const struct nlattr * const cda[])1970 static void ctnetlink_change_mark(struct nf_conn *ct,
1971 				    const struct nlattr * const cda[])
1972 {
1973 	u32 mark, newmark, mask = 0;
1974 
1975 	if (cda[CTA_MARK_MASK])
1976 		mask = ~ntohl(nla_get_be32(cda[CTA_MARK_MASK]));
1977 
1978 	mark = ntohl(nla_get_be32(cda[CTA_MARK]));
1979 	newmark = (READ_ONCE(ct->mark) & mask) ^ mark;
1980 	if (newmark != READ_ONCE(ct->mark))
1981 		WRITE_ONCE(ct->mark, newmark);
1982 }
1983 #endif
1984 
1985 static const struct nla_policy protoinfo_policy[CTA_PROTOINFO_MAX+1] = {
1986 	[CTA_PROTOINFO_TCP]	= { .type = NLA_NESTED },
1987 	[CTA_PROTOINFO_DCCP]	= { .type = NLA_NESTED },
1988 	[CTA_PROTOINFO_SCTP]	= { .type = NLA_NESTED },
1989 };
1990 
ctnetlink_change_protoinfo(struct nf_conn * ct,const struct nlattr * const cda[])1991 static int ctnetlink_change_protoinfo(struct nf_conn *ct,
1992 				      const struct nlattr * const cda[])
1993 {
1994 	const struct nlattr *attr = cda[CTA_PROTOINFO];
1995 	const struct nf_conntrack_l4proto *l4proto;
1996 	struct nlattr *tb[CTA_PROTOINFO_MAX+1];
1997 	int err = 0;
1998 
1999 	err = nla_parse_nested_deprecated(tb, CTA_PROTOINFO_MAX, attr,
2000 					  protoinfo_policy, NULL);
2001 	if (err < 0)
2002 		return err;
2003 
2004 	l4proto = nf_ct_l4proto_find(nf_ct_protonum(ct));
2005 	if (l4proto->from_nlattr)
2006 		err = l4proto->from_nlattr(tb, ct);
2007 
2008 	return err;
2009 }
2010 
2011 static const struct nla_policy seqadj_policy[CTA_SEQADJ_MAX+1] = {
2012 	[CTA_SEQADJ_CORRECTION_POS]	= { .type = NLA_U32 },
2013 	[CTA_SEQADJ_OFFSET_BEFORE]	= { .type = NLA_U32 },
2014 	[CTA_SEQADJ_OFFSET_AFTER]	= { .type = NLA_U32 },
2015 };
2016 
change_seq_adj(struct nf_ct_seqadj * seq,const struct nlattr * const attr)2017 static int change_seq_adj(struct nf_ct_seqadj *seq,
2018 			  const struct nlattr * const attr)
2019 {
2020 	int err;
2021 	struct nlattr *cda[CTA_SEQADJ_MAX+1];
2022 
2023 	err = nla_parse_nested_deprecated(cda, CTA_SEQADJ_MAX, attr,
2024 					  seqadj_policy, NULL);
2025 	if (err < 0)
2026 		return err;
2027 
2028 	if (!cda[CTA_SEQADJ_CORRECTION_POS])
2029 		return -EINVAL;
2030 
2031 	seq->correction_pos =
2032 		ntohl(nla_get_be32(cda[CTA_SEQADJ_CORRECTION_POS]));
2033 
2034 	if (!cda[CTA_SEQADJ_OFFSET_BEFORE])
2035 		return -EINVAL;
2036 
2037 	seq->offset_before =
2038 		ntohl(nla_get_be32(cda[CTA_SEQADJ_OFFSET_BEFORE]));
2039 
2040 	if (!cda[CTA_SEQADJ_OFFSET_AFTER])
2041 		return -EINVAL;
2042 
2043 	seq->offset_after =
2044 		ntohl(nla_get_be32(cda[CTA_SEQADJ_OFFSET_AFTER]));
2045 
2046 	return 0;
2047 }
2048 
2049 static int
ctnetlink_change_seq_adj(struct nf_conn * ct,const struct nlattr * const cda[])2050 ctnetlink_change_seq_adj(struct nf_conn *ct,
2051 			 const struct nlattr * const cda[])
2052 {
2053 	struct nf_conn_seqadj *seqadj = nfct_seqadj(ct);
2054 	int ret = 0;
2055 
2056 	if (!seqadj)
2057 		return 0;
2058 
2059 	spin_lock_bh(&ct->lock);
2060 	if (cda[CTA_SEQ_ADJ_ORIG]) {
2061 		ret = change_seq_adj(&seqadj->seq[IP_CT_DIR_ORIGINAL],
2062 				     cda[CTA_SEQ_ADJ_ORIG]);
2063 		if (ret < 0)
2064 			goto err;
2065 
2066 		set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
2067 	}
2068 
2069 	if (cda[CTA_SEQ_ADJ_REPLY]) {
2070 		ret = change_seq_adj(&seqadj->seq[IP_CT_DIR_REPLY],
2071 				     cda[CTA_SEQ_ADJ_REPLY]);
2072 		if (ret < 0)
2073 			goto err;
2074 
2075 		set_bit(IPS_SEQ_ADJUST_BIT, &ct->status);
2076 	}
2077 
2078 	spin_unlock_bh(&ct->lock);
2079 	return 0;
2080 err:
2081 	spin_unlock_bh(&ct->lock);
2082 	return ret;
2083 }
2084 
2085 static const struct nla_policy synproxy_policy[CTA_SYNPROXY_MAX + 1] = {
2086 	[CTA_SYNPROXY_ISN]	= { .type = NLA_U32 },
2087 	[CTA_SYNPROXY_ITS]	= { .type = NLA_U32 },
2088 	[CTA_SYNPROXY_TSOFF]	= { .type = NLA_U32 },
2089 };
2090 
ctnetlink_change_synproxy(struct nf_conn * ct,const struct nlattr * const cda[])2091 static int ctnetlink_change_synproxy(struct nf_conn *ct,
2092 				     const struct nlattr * const cda[])
2093 {
2094 	struct nf_conn_synproxy *synproxy = nfct_synproxy(ct);
2095 	struct nlattr *tb[CTA_SYNPROXY_MAX + 1];
2096 	int err;
2097 
2098 	if (!synproxy)
2099 		return 0;
2100 
2101 	err = nla_parse_nested_deprecated(tb, CTA_SYNPROXY_MAX,
2102 					  cda[CTA_SYNPROXY], synproxy_policy,
2103 					  NULL);
2104 	if (err < 0)
2105 		return err;
2106 
2107 	if (!tb[CTA_SYNPROXY_ISN] ||
2108 	    !tb[CTA_SYNPROXY_ITS] ||
2109 	    !tb[CTA_SYNPROXY_TSOFF])
2110 		return -EINVAL;
2111 
2112 	synproxy->isn = ntohl(nla_get_be32(tb[CTA_SYNPROXY_ISN]));
2113 	synproxy->its = ntohl(nla_get_be32(tb[CTA_SYNPROXY_ITS]));
2114 	synproxy->tsoff = ntohl(nla_get_be32(tb[CTA_SYNPROXY_TSOFF]));
2115 
2116 	return 0;
2117 }
2118 
2119 static int
ctnetlink_attach_labels(struct nf_conn * ct,const struct nlattr * const cda[])2120 ctnetlink_attach_labels(struct nf_conn *ct, const struct nlattr * const cda[])
2121 {
2122 #ifdef CONFIG_NF_CONNTRACK_LABELS
2123 	size_t len = nla_len(cda[CTA_LABELS]);
2124 	const void *mask = cda[CTA_LABELS_MASK];
2125 
2126 	if (len & (sizeof(u32)-1)) /* must be multiple of u32 */
2127 		return -EINVAL;
2128 
2129 	if (mask) {
2130 		if (nla_len(cda[CTA_LABELS_MASK]) == 0 ||
2131 		    nla_len(cda[CTA_LABELS_MASK]) != len)
2132 			return -EINVAL;
2133 		mask = nla_data(cda[CTA_LABELS_MASK]);
2134 	}
2135 
2136 	len /= sizeof(u32);
2137 
2138 	return nf_connlabels_replace(ct, nla_data(cda[CTA_LABELS]), mask, len);
2139 #else
2140 	return -EOPNOTSUPP;
2141 #endif
2142 }
2143 
2144 static int
ctnetlink_change_conntrack(struct nf_conn * ct,const struct nlattr * const cda[])2145 ctnetlink_change_conntrack(struct nf_conn *ct,
2146 			   const struct nlattr * const cda[])
2147 {
2148 	int err;
2149 
2150 	/* only allow NAT changes and master assignation for new conntracks */
2151 	if (cda[CTA_NAT_SRC] || cda[CTA_NAT_DST] || cda[CTA_TUPLE_MASTER])
2152 		return -EOPNOTSUPP;
2153 
2154 	if (cda[CTA_HELP]) {
2155 		err = ctnetlink_change_helper(ct, cda);
2156 		if (err < 0)
2157 			return err;
2158 	}
2159 
2160 	if (cda[CTA_TIMEOUT]) {
2161 		err = ctnetlink_change_timeout(ct, cda);
2162 		if (err < 0)
2163 			return err;
2164 	}
2165 
2166 	if (cda[CTA_STATUS]) {
2167 		err = ctnetlink_change_status(ct, cda);
2168 		if (err < 0)
2169 			return err;
2170 	}
2171 
2172 	if (cda[CTA_PROTOINFO]) {
2173 		err = ctnetlink_change_protoinfo(ct, cda);
2174 		if (err < 0)
2175 			return err;
2176 	}
2177 
2178 #if defined(CONFIG_NF_CONNTRACK_MARK)
2179 	if (cda[CTA_MARK])
2180 		ctnetlink_change_mark(ct, cda);
2181 #endif
2182 
2183 	if (cda[CTA_SEQ_ADJ_ORIG] || cda[CTA_SEQ_ADJ_REPLY]) {
2184 		err = ctnetlink_change_seq_adj(ct, cda);
2185 		if (err < 0)
2186 			return err;
2187 	}
2188 
2189 	if (cda[CTA_SYNPROXY]) {
2190 		err = ctnetlink_change_synproxy(ct, cda);
2191 		if (err < 0)
2192 			return err;
2193 	}
2194 
2195 	if (cda[CTA_LABELS]) {
2196 		err = ctnetlink_attach_labels(ct, cda);
2197 		if (err < 0)
2198 			return err;
2199 	}
2200 
2201 	return 0;
2202 }
2203 
2204 static struct nf_conn *
ctnetlink_create_conntrack(struct net * net,const struct nf_conntrack_zone * zone,const struct nlattr * const cda[],struct nf_conntrack_tuple * otuple,struct nf_conntrack_tuple * rtuple,u8 u3)2205 ctnetlink_create_conntrack(struct net *net,
2206 			   const struct nf_conntrack_zone *zone,
2207 			   const struct nlattr * const cda[],
2208 			   struct nf_conntrack_tuple *otuple,
2209 			   struct nf_conntrack_tuple *rtuple,
2210 			   u8 u3)
2211 {
2212 	struct nf_conn *ct;
2213 	int err = -EINVAL;
2214 	struct nf_conntrack_helper *helper;
2215 	struct nf_conn_tstamp *tstamp;
2216 	u64 timeout;
2217 
2218 	ct = nf_conntrack_alloc(net, zone, otuple, rtuple, GFP_ATOMIC);
2219 	if (IS_ERR(ct))
2220 		return ERR_PTR(-ENOMEM);
2221 
2222 	if (!cda[CTA_TIMEOUT])
2223 		goto err1;
2224 
2225 	timeout = (u64)ntohl(nla_get_be32(cda[CTA_TIMEOUT])) * HZ;
2226 	if (timeout > INT_MAX)
2227 		timeout = INT_MAX;
2228 	ct->timeout = (u32)timeout + nfct_time_stamp;
2229 
2230 	rcu_read_lock();
2231  	if (cda[CTA_HELP]) {
2232 		char *helpname = NULL;
2233 		struct nlattr *helpinfo = NULL;
2234 
2235 		err = ctnetlink_parse_help(cda[CTA_HELP], &helpname, &helpinfo);
2236  		if (err < 0)
2237 			goto err2;
2238 
2239 		helper = __nf_conntrack_helper_find(helpname, nf_ct_l3num(ct),
2240 						    nf_ct_protonum(ct));
2241 		if (helper == NULL) {
2242 			rcu_read_unlock();
2243 #ifdef CONFIG_MODULES
2244 			if (request_module("nfct-helper-%s", helpname) < 0) {
2245 				err = -EOPNOTSUPP;
2246 				goto err1;
2247 			}
2248 
2249 			rcu_read_lock();
2250 			helper = __nf_conntrack_helper_find(helpname,
2251 							    nf_ct_l3num(ct),
2252 							    nf_ct_protonum(ct));
2253 			if (helper) {
2254 				err = -EAGAIN;
2255 				goto err2;
2256 			}
2257 			rcu_read_unlock();
2258 #endif
2259 			err = -EOPNOTSUPP;
2260 			goto err1;
2261 		} else {
2262 			struct nf_conn_help *help;
2263 
2264 			help = nf_ct_helper_ext_add(ct, GFP_ATOMIC);
2265 			if (help == NULL) {
2266 				err = -ENOMEM;
2267 				goto err2;
2268 			}
2269 			/* set private helper data if allowed. */
2270 			if (helper->from_nlattr)
2271 				helper->from_nlattr(helpinfo, ct);
2272 
2273 			/* disable helper auto-assignment for this entry */
2274 			ct->status |= IPS_HELPER;
2275 			RCU_INIT_POINTER(help->helper, helper);
2276 		}
2277 	} else {
2278 		/* try an implicit helper assignation */
2279 		err = __nf_ct_try_assign_helper(ct, NULL, GFP_ATOMIC);
2280 		if (err < 0)
2281 			goto err2;
2282 	}
2283 
2284 	err = ctnetlink_setup_nat(ct, cda);
2285 	if (err < 0)
2286 		goto err2;
2287 
2288 	nf_ct_acct_ext_add(ct, GFP_ATOMIC);
2289 	nf_ct_tstamp_ext_add(ct, GFP_ATOMIC);
2290 	nf_ct_ecache_ext_add(ct, 0, 0, GFP_ATOMIC);
2291 	nf_ct_labels_ext_add(ct);
2292 	nfct_seqadj_ext_add(ct);
2293 	nfct_synproxy_ext_add(ct);
2294 
2295 	/* we must add conntrack extensions before confirmation. */
2296 	ct->status |= IPS_CONFIRMED;
2297 
2298 	if (cda[CTA_STATUS]) {
2299 		err = ctnetlink_change_status(ct, cda);
2300 		if (err < 0)
2301 			goto err2;
2302 	}
2303 
2304 	if (cda[CTA_SEQ_ADJ_ORIG] || cda[CTA_SEQ_ADJ_REPLY]) {
2305 		err = ctnetlink_change_seq_adj(ct, cda);
2306 		if (err < 0)
2307 			goto err2;
2308 	}
2309 
2310 	memset(&ct->proto, 0, sizeof(ct->proto));
2311 	if (cda[CTA_PROTOINFO]) {
2312 		err = ctnetlink_change_protoinfo(ct, cda);
2313 		if (err < 0)
2314 			goto err2;
2315 	}
2316 
2317 	if (cda[CTA_SYNPROXY]) {
2318 		err = ctnetlink_change_synproxy(ct, cda);
2319 		if (err < 0)
2320 			goto err2;
2321 	}
2322 
2323 #if defined(CONFIG_NF_CONNTRACK_MARK)
2324 	if (cda[CTA_MARK])
2325 		ctnetlink_change_mark(ct, cda);
2326 #endif
2327 
2328 	/* setup master conntrack: this is a confirmed expectation */
2329 	if (cda[CTA_TUPLE_MASTER]) {
2330 		struct nf_conntrack_tuple master;
2331 		struct nf_conntrack_tuple_hash *master_h;
2332 		struct nf_conn *master_ct;
2333 
2334 		err = ctnetlink_parse_tuple(cda, &master, CTA_TUPLE_MASTER,
2335 					    u3, NULL);
2336 		if (err < 0)
2337 			goto err2;
2338 
2339 		master_h = nf_conntrack_find_get(net, zone, &master);
2340 		if (master_h == NULL) {
2341 			err = -ENOENT;
2342 			goto err2;
2343 		}
2344 		master_ct = nf_ct_tuplehash_to_ctrack(master_h);
2345 		__set_bit(IPS_EXPECTED_BIT, &ct->status);
2346 		ct->master = master_ct;
2347 	}
2348 	tstamp = nf_conn_tstamp_find(ct);
2349 	if (tstamp)
2350 		tstamp->start = ktime_get_real_ns();
2351 
2352 	err = nf_conntrack_hash_check_insert(ct);
2353 	if (err < 0)
2354 		goto err3;
2355 
2356 	rcu_read_unlock();
2357 
2358 	return ct;
2359 
2360 err3:
2361 	if (ct->master)
2362 		nf_ct_put(ct->master);
2363 err2:
2364 	rcu_read_unlock();
2365 err1:
2366 	nf_conntrack_free(ct);
2367 	return ERR_PTR(err);
2368 }
2369 
ctnetlink_new_conntrack(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)2370 static int ctnetlink_new_conntrack(struct net *net, struct sock *ctnl,
2371 				   struct sk_buff *skb,
2372 				   const struct nlmsghdr *nlh,
2373 				   const struct nlattr * const cda[],
2374 				   struct netlink_ext_ack *extack)
2375 {
2376 	struct nf_conntrack_tuple otuple, rtuple;
2377 	struct nf_conntrack_tuple_hash *h = NULL;
2378 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
2379 	struct nf_conn *ct;
2380 	u_int8_t u3 = nfmsg->nfgen_family;
2381 	struct nf_conntrack_zone zone;
2382 	int err;
2383 
2384 	err = ctnetlink_parse_zone(cda[CTA_ZONE], &zone);
2385 	if (err < 0)
2386 		return err;
2387 
2388 	if (cda[CTA_TUPLE_ORIG]) {
2389 		err = ctnetlink_parse_tuple(cda, &otuple, CTA_TUPLE_ORIG,
2390 					    u3, &zone);
2391 		if (err < 0)
2392 			return err;
2393 	}
2394 
2395 	if (cda[CTA_TUPLE_REPLY]) {
2396 		err = ctnetlink_parse_tuple(cda, &rtuple, CTA_TUPLE_REPLY,
2397 					    u3, &zone);
2398 		if (err < 0)
2399 			return err;
2400 	}
2401 
2402 	if (cda[CTA_TUPLE_ORIG])
2403 		h = nf_conntrack_find_get(net, &zone, &otuple);
2404 	else if (cda[CTA_TUPLE_REPLY])
2405 		h = nf_conntrack_find_get(net, &zone, &rtuple);
2406 
2407 	if (h == NULL) {
2408 		err = -ENOENT;
2409 		if (nlh->nlmsg_flags & NLM_F_CREATE) {
2410 			enum ip_conntrack_events events;
2411 
2412 			if (!cda[CTA_TUPLE_ORIG] || !cda[CTA_TUPLE_REPLY])
2413 				return -EINVAL;
2414 			if (otuple.dst.protonum != rtuple.dst.protonum)
2415 				return -EINVAL;
2416 
2417 			ct = ctnetlink_create_conntrack(net, &zone, cda, &otuple,
2418 							&rtuple, u3);
2419 			if (IS_ERR(ct))
2420 				return PTR_ERR(ct);
2421 
2422 			err = 0;
2423 			if (test_bit(IPS_EXPECTED_BIT, &ct->status))
2424 				events = 1 << IPCT_RELATED;
2425 			else
2426 				events = 1 << IPCT_NEW;
2427 
2428 			if (cda[CTA_LABELS] &&
2429 			    ctnetlink_attach_labels(ct, cda) == 0)
2430 				events |= (1 << IPCT_LABEL);
2431 
2432 			nf_conntrack_eventmask_report((1 << IPCT_REPLY) |
2433 						      (1 << IPCT_ASSURED) |
2434 						      (1 << IPCT_HELPER) |
2435 						      (1 << IPCT_PROTOINFO) |
2436 						      (1 << IPCT_SEQADJ) |
2437 						      (1 << IPCT_MARK) |
2438 						      (1 << IPCT_SYNPROXY) |
2439 						      events,
2440 						      ct, NETLINK_CB(skb).portid,
2441 						      nlmsg_report(nlh));
2442 			nf_ct_put(ct);
2443 		}
2444 
2445 		return err;
2446 	}
2447 	/* implicit 'else' */
2448 
2449 	err = -EEXIST;
2450 	ct = nf_ct_tuplehash_to_ctrack(h);
2451 	if (!(nlh->nlmsg_flags & NLM_F_EXCL)) {
2452 		err = ctnetlink_change_conntrack(ct, cda);
2453 		if (err == 0) {
2454 			nf_conntrack_eventmask_report((1 << IPCT_REPLY) |
2455 						      (1 << IPCT_ASSURED) |
2456 						      (1 << IPCT_HELPER) |
2457 						      (1 << IPCT_LABEL) |
2458 						      (1 << IPCT_PROTOINFO) |
2459 						      (1 << IPCT_SEQADJ) |
2460 						      (1 << IPCT_MARK) |
2461 						      (1 << IPCT_SYNPROXY),
2462 						      ct, NETLINK_CB(skb).portid,
2463 						      nlmsg_report(nlh));
2464 		}
2465 	}
2466 
2467 	nf_ct_put(ct);
2468 	return err;
2469 }
2470 
2471 static int
ctnetlink_ct_stat_cpu_fill_info(struct sk_buff * skb,u32 portid,u32 seq,__u16 cpu,const struct ip_conntrack_stat * st)2472 ctnetlink_ct_stat_cpu_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
2473 				__u16 cpu, const struct ip_conntrack_stat *st)
2474 {
2475 	struct nlmsghdr *nlh;
2476 	unsigned int flags = portid ? NLM_F_MULTI : 0, event;
2477 
2478 	event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK,
2479 			      IPCTNL_MSG_CT_GET_STATS_CPU);
2480 	nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
2481 			   NFNETLINK_V0, htons(cpu));
2482 	if (!nlh)
2483 		goto nlmsg_failure;
2484 
2485 	if (nla_put_be32(skb, CTA_STATS_FOUND, htonl(st->found)) ||
2486 	    nla_put_be32(skb, CTA_STATS_INVALID, htonl(st->invalid)) ||
2487 	    nla_put_be32(skb, CTA_STATS_INSERT, htonl(st->insert)) ||
2488 	    nla_put_be32(skb, CTA_STATS_INSERT_FAILED,
2489 				htonl(st->insert_failed)) ||
2490 	    nla_put_be32(skb, CTA_STATS_DROP, htonl(st->drop)) ||
2491 	    nla_put_be32(skb, CTA_STATS_EARLY_DROP, htonl(st->early_drop)) ||
2492 	    nla_put_be32(skb, CTA_STATS_ERROR, htonl(st->error)) ||
2493 	    nla_put_be32(skb, CTA_STATS_SEARCH_RESTART,
2494 				htonl(st->search_restart)) ||
2495 	    nla_put_be32(skb, CTA_STATS_CLASH_RESOLVE,
2496 				htonl(st->clash_resolve)))
2497 		goto nla_put_failure;
2498 
2499 	nlmsg_end(skb, nlh);
2500 	return skb->len;
2501 
2502 nla_put_failure:
2503 nlmsg_failure:
2504 	nlmsg_cancel(skb, nlh);
2505 	return -1;
2506 }
2507 
2508 static int
ctnetlink_ct_stat_cpu_dump(struct sk_buff * skb,struct netlink_callback * cb)2509 ctnetlink_ct_stat_cpu_dump(struct sk_buff *skb, struct netlink_callback *cb)
2510 {
2511 	int cpu;
2512 	struct net *net = sock_net(skb->sk);
2513 
2514 	if (cb->args[0] == nr_cpu_ids)
2515 		return 0;
2516 
2517 	for (cpu = cb->args[0]; cpu < nr_cpu_ids; cpu++) {
2518 		const struct ip_conntrack_stat *st;
2519 
2520 		if (!cpu_possible(cpu))
2521 			continue;
2522 
2523 		st = per_cpu_ptr(net->ct.stat, cpu);
2524 		if (ctnetlink_ct_stat_cpu_fill_info(skb,
2525 						    NETLINK_CB(cb->skb).portid,
2526 						    cb->nlh->nlmsg_seq,
2527 						    cpu, st) < 0)
2528 				break;
2529 	}
2530 	cb->args[0] = cpu;
2531 
2532 	return skb->len;
2533 }
2534 
ctnetlink_stat_ct_cpu(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)2535 static int ctnetlink_stat_ct_cpu(struct net *net, struct sock *ctnl,
2536 				 struct sk_buff *skb,
2537 				 const struct nlmsghdr *nlh,
2538 				 const struct nlattr * const cda[],
2539 				 struct netlink_ext_ack *extack)
2540 {
2541 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
2542 		struct netlink_dump_control c = {
2543 			.dump = ctnetlink_ct_stat_cpu_dump,
2544 		};
2545 		return netlink_dump_start(ctnl, skb, nlh, &c);
2546 	}
2547 
2548 	return 0;
2549 }
2550 
2551 static int
ctnetlink_stat_ct_fill_info(struct sk_buff * skb,u32 portid,u32 seq,u32 type,struct net * net)2552 ctnetlink_stat_ct_fill_info(struct sk_buff *skb, u32 portid, u32 seq, u32 type,
2553 			    struct net *net)
2554 {
2555 	struct nlmsghdr *nlh;
2556 	unsigned int flags = portid ? NLM_F_MULTI : 0, event;
2557 	unsigned int nr_conntracks = atomic_read(&net->ct.count);
2558 
2559 	event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK, IPCTNL_MSG_CT_GET_STATS);
2560 	nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
2561 			   NFNETLINK_V0, 0);
2562 	if (!nlh)
2563 		goto nlmsg_failure;
2564 
2565 	if (nla_put_be32(skb, CTA_STATS_GLOBAL_ENTRIES, htonl(nr_conntracks)))
2566 		goto nla_put_failure;
2567 
2568 	if (nla_put_be32(skb, CTA_STATS_GLOBAL_MAX_ENTRIES, htonl(nf_conntrack_max)))
2569 		goto nla_put_failure;
2570 
2571 	nlmsg_end(skb, nlh);
2572 	return skb->len;
2573 
2574 nla_put_failure:
2575 nlmsg_failure:
2576 	nlmsg_cancel(skb, nlh);
2577 	return -1;
2578 }
2579 
ctnetlink_stat_ct(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)2580 static int ctnetlink_stat_ct(struct net *net, struct sock *ctnl,
2581 			     struct sk_buff *skb, const struct nlmsghdr *nlh,
2582 			     const struct nlattr * const cda[],
2583 			     struct netlink_ext_ack *extack)
2584 {
2585 	struct sk_buff *skb2;
2586 	int err;
2587 
2588 	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
2589 	if (skb2 == NULL)
2590 		return -ENOMEM;
2591 
2592 	err = ctnetlink_stat_ct_fill_info(skb2, NETLINK_CB(skb).portid,
2593 					  nlh->nlmsg_seq,
2594 					  NFNL_MSG_TYPE(nlh->nlmsg_type),
2595 					  sock_net(skb->sk));
2596 	if (err <= 0)
2597 		goto free;
2598 
2599 	err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
2600 	if (err < 0)
2601 		goto out;
2602 
2603 	return 0;
2604 
2605 free:
2606 	kfree_skb(skb2);
2607 out:
2608 	/* this avoids a loop in nfnetlink. */
2609 	return err == -EAGAIN ? -ENOBUFS : err;
2610 }
2611 
2612 static const struct nla_policy exp_nla_policy[CTA_EXPECT_MAX+1] = {
2613 	[CTA_EXPECT_MASTER]	= { .type = NLA_NESTED },
2614 	[CTA_EXPECT_TUPLE]	= { .type = NLA_NESTED },
2615 	[CTA_EXPECT_MASK]	= { .type = NLA_NESTED },
2616 	[CTA_EXPECT_TIMEOUT]	= { .type = NLA_U32 },
2617 	[CTA_EXPECT_ID]		= { .type = NLA_U32 },
2618 	[CTA_EXPECT_HELP_NAME]	= { .type = NLA_NUL_STRING,
2619 				    .len = NF_CT_HELPER_NAME_LEN - 1 },
2620 	[CTA_EXPECT_ZONE]	= { .type = NLA_U16 },
2621 	[CTA_EXPECT_FLAGS]	= { .type = NLA_U32 },
2622 	[CTA_EXPECT_CLASS]	= { .type = NLA_U32 },
2623 	[CTA_EXPECT_NAT]	= { .type = NLA_NESTED },
2624 	[CTA_EXPECT_FN]		= { .type = NLA_NUL_STRING },
2625 };
2626 
2627 static struct nf_conntrack_expect *
2628 ctnetlink_alloc_expect(const struct nlattr *const cda[], struct nf_conn *ct,
2629 		       struct nf_conntrack_helper *helper,
2630 		       struct nf_conntrack_tuple *tuple,
2631 		       struct nf_conntrack_tuple *mask);
2632 
2633 #ifdef CONFIG_NETFILTER_NETLINK_GLUE_CT
2634 static size_t
ctnetlink_glue_build_size(const struct nf_conn * ct)2635 ctnetlink_glue_build_size(const struct nf_conn *ct)
2636 {
2637 	return 3 * nla_total_size(0) /* CTA_TUPLE_ORIG|REPL|MASTER */
2638 	       + 3 * nla_total_size(0) /* CTA_TUPLE_IP */
2639 	       + 3 * nla_total_size(0) /* CTA_TUPLE_PROTO */
2640 	       + 3 * nla_total_size(sizeof(u_int8_t)) /* CTA_PROTO_NUM */
2641 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_ID */
2642 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_STATUS */
2643 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_TIMEOUT */
2644 	       + nla_total_size(0) /* CTA_PROTOINFO */
2645 	       + nla_total_size(0) /* CTA_HELP */
2646 	       + nla_total_size(NF_CT_HELPER_NAME_LEN) /* CTA_HELP_NAME */
2647 	       + ctnetlink_secctx_size(ct)
2648 #if IS_ENABLED(CONFIG_NF_NAT)
2649 	       + 2 * nla_total_size(0) /* CTA_NAT_SEQ_ADJ_ORIG|REPL */
2650 	       + 6 * nla_total_size(sizeof(u_int32_t)) /* CTA_NAT_SEQ_OFFSET */
2651 #endif
2652 #ifdef CONFIG_NF_CONNTRACK_MARK
2653 	       + nla_total_size(sizeof(u_int32_t)) /* CTA_MARK */
2654 #endif
2655 #ifdef CONFIG_NF_CONNTRACK_ZONES
2656 	       + nla_total_size(sizeof(u_int16_t)) /* CTA_ZONE|CTA_TUPLE_ZONE */
2657 #endif
2658 	       + ctnetlink_proto_size(ct)
2659 	       ;
2660 }
2661 
ctnetlink_glue_get_ct(const struct sk_buff * skb,enum ip_conntrack_info * ctinfo)2662 static struct nf_conn *ctnetlink_glue_get_ct(const struct sk_buff *skb,
2663 					     enum ip_conntrack_info *ctinfo)
2664 {
2665 	return nf_ct_get(skb, ctinfo);
2666 }
2667 
__ctnetlink_glue_build(struct sk_buff * skb,struct nf_conn * ct)2668 static int __ctnetlink_glue_build(struct sk_buff *skb, struct nf_conn *ct)
2669 {
2670 	const struct nf_conntrack_zone *zone;
2671 	struct nlattr *nest_parms;
2672 
2673 	zone = nf_ct_zone(ct);
2674 
2675 	nest_parms = nla_nest_start(skb, CTA_TUPLE_ORIG);
2676 	if (!nest_parms)
2677 		goto nla_put_failure;
2678 	if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_ORIGINAL)) < 0)
2679 		goto nla_put_failure;
2680 	if (ctnetlink_dump_zone_id(skb, CTA_TUPLE_ZONE, zone,
2681 				   NF_CT_ZONE_DIR_ORIG) < 0)
2682 		goto nla_put_failure;
2683 	nla_nest_end(skb, nest_parms);
2684 
2685 	nest_parms = nla_nest_start(skb, CTA_TUPLE_REPLY);
2686 	if (!nest_parms)
2687 		goto nla_put_failure;
2688 	if (ctnetlink_dump_tuples(skb, nf_ct_tuple(ct, IP_CT_DIR_REPLY)) < 0)
2689 		goto nla_put_failure;
2690 	if (ctnetlink_dump_zone_id(skb, CTA_TUPLE_ZONE, zone,
2691 				   NF_CT_ZONE_DIR_REPL) < 0)
2692 		goto nla_put_failure;
2693 	nla_nest_end(skb, nest_parms);
2694 
2695 	if (ctnetlink_dump_zone_id(skb, CTA_ZONE, zone,
2696 				   NF_CT_DEFAULT_ZONE_DIR) < 0)
2697 		goto nla_put_failure;
2698 
2699 	if (ctnetlink_dump_id(skb, ct) < 0)
2700 		goto nla_put_failure;
2701 
2702 	if (ctnetlink_dump_status(skb, ct) < 0)
2703 		goto nla_put_failure;
2704 
2705 	if (ctnetlink_dump_timeout(skb, ct) < 0)
2706 		goto nla_put_failure;
2707 
2708 	if (ctnetlink_dump_protoinfo(skb, ct) < 0)
2709 		goto nla_put_failure;
2710 
2711 	if (ctnetlink_dump_helpinfo(skb, ct) < 0)
2712 		goto nla_put_failure;
2713 
2714 #ifdef CONFIG_NF_CONNTRACK_SECMARK
2715 	if (ct->secmark && ctnetlink_dump_secctx(skb, ct) < 0)
2716 		goto nla_put_failure;
2717 #endif
2718 	if (ct->master && ctnetlink_dump_master(skb, ct) < 0)
2719 		goto nla_put_failure;
2720 
2721 	if ((ct->status & IPS_SEQ_ADJUST) &&
2722 	    ctnetlink_dump_ct_seq_adj(skb, ct) < 0)
2723 		goto nla_put_failure;
2724 
2725 	if (ctnetlink_dump_ct_synproxy(skb, ct) < 0)
2726 		goto nla_put_failure;
2727 
2728 #ifdef CONFIG_NF_CONNTRACK_MARK
2729 	if (ctnetlink_dump_mark(skb, ct, true) < 0)
2730 		goto nla_put_failure;
2731 #endif
2732 	if (ctnetlink_dump_labels(skb, ct) < 0)
2733 		goto nla_put_failure;
2734 	return 0;
2735 
2736 nla_put_failure:
2737 	return -ENOSPC;
2738 }
2739 
2740 static int
ctnetlink_glue_build(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,u_int16_t ct_attr,u_int16_t ct_info_attr)2741 ctnetlink_glue_build(struct sk_buff *skb, struct nf_conn *ct,
2742 		     enum ip_conntrack_info ctinfo,
2743 		     u_int16_t ct_attr, u_int16_t ct_info_attr)
2744 {
2745 	struct nlattr *nest_parms;
2746 
2747 	nest_parms = nla_nest_start(skb, ct_attr);
2748 	if (!nest_parms)
2749 		goto nla_put_failure;
2750 
2751 	if (__ctnetlink_glue_build(skb, ct) < 0)
2752 		goto nla_put_failure;
2753 
2754 	nla_nest_end(skb, nest_parms);
2755 
2756 	if (nla_put_be32(skb, ct_info_attr, htonl(ctinfo)))
2757 		goto nla_put_failure;
2758 
2759 	return 0;
2760 
2761 nla_put_failure:
2762 	return -ENOSPC;
2763 }
2764 
2765 static int
ctnetlink_update_status(struct nf_conn * ct,const struct nlattr * const cda[])2766 ctnetlink_update_status(struct nf_conn *ct, const struct nlattr * const cda[])
2767 {
2768 	unsigned int status = ntohl(nla_get_be32(cda[CTA_STATUS]));
2769 	unsigned long d = ct->status ^ status;
2770 
2771 	if (d & IPS_SEEN_REPLY && !(status & IPS_SEEN_REPLY))
2772 		/* SEEN_REPLY bit can only be set */
2773 		return -EBUSY;
2774 
2775 	if (d & IPS_ASSURED && !(status & IPS_ASSURED))
2776 		/* ASSURED bit can only be set */
2777 		return -EBUSY;
2778 
2779 	/* This check is less strict than ctnetlink_change_status()
2780 	 * because callers often flip IPS_EXPECTED bits when sending
2781 	 * an NFQA_CT attribute to the kernel.  So ignore the
2782 	 * unchangeable bits but do not error out. Also user programs
2783 	 * are allowed to clear the bits that they are allowed to change.
2784 	 */
2785 	__ctnetlink_change_status(ct, status, ~status);
2786 	return 0;
2787 }
2788 
2789 static int
ctnetlink_glue_parse_ct(const struct nlattr * cda[],struct nf_conn * ct)2790 ctnetlink_glue_parse_ct(const struct nlattr *cda[], struct nf_conn *ct)
2791 {
2792 	int err;
2793 
2794 	if (cda[CTA_TIMEOUT]) {
2795 		err = ctnetlink_change_timeout(ct, cda);
2796 		if (err < 0)
2797 			return err;
2798 	}
2799 	if (cda[CTA_STATUS]) {
2800 		err = ctnetlink_update_status(ct, cda);
2801 		if (err < 0)
2802 			return err;
2803 	}
2804 	if (cda[CTA_HELP]) {
2805 		err = ctnetlink_change_helper(ct, cda);
2806 		if (err < 0)
2807 			return err;
2808 	}
2809 	if (cda[CTA_LABELS]) {
2810 		err = ctnetlink_attach_labels(ct, cda);
2811 		if (err < 0)
2812 			return err;
2813 	}
2814 #if defined(CONFIG_NF_CONNTRACK_MARK)
2815 	if (cda[CTA_MARK]) {
2816 		ctnetlink_change_mark(ct, cda);
2817 	}
2818 #endif
2819 	return 0;
2820 }
2821 
2822 static int
ctnetlink_glue_parse(const struct nlattr * attr,struct nf_conn * ct)2823 ctnetlink_glue_parse(const struct nlattr *attr, struct nf_conn *ct)
2824 {
2825 	struct nlattr *cda[CTA_MAX+1];
2826 	int ret;
2827 
2828 	ret = nla_parse_nested_deprecated(cda, CTA_MAX, attr, ct_nla_policy,
2829 					  NULL);
2830 	if (ret < 0)
2831 		return ret;
2832 
2833 	return ctnetlink_glue_parse_ct((const struct nlattr **)cda, ct);
2834 }
2835 
ctnetlink_glue_exp_parse(const struct nlattr * const * cda,const struct nf_conn * ct,struct nf_conntrack_tuple * tuple,struct nf_conntrack_tuple * mask)2836 static int ctnetlink_glue_exp_parse(const struct nlattr * const *cda,
2837 				    const struct nf_conn *ct,
2838 				    struct nf_conntrack_tuple *tuple,
2839 				    struct nf_conntrack_tuple *mask)
2840 {
2841 	int err;
2842 
2843 	err = ctnetlink_parse_tuple(cda, tuple, CTA_EXPECT_TUPLE,
2844 				    nf_ct_l3num(ct), NULL);
2845 	if (err < 0)
2846 		return err;
2847 
2848 	return ctnetlink_parse_tuple(cda, mask, CTA_EXPECT_MASK,
2849 				     nf_ct_l3num(ct), NULL);
2850 }
2851 
2852 static int
ctnetlink_glue_attach_expect(const struct nlattr * attr,struct nf_conn * ct,u32 portid,u32 report)2853 ctnetlink_glue_attach_expect(const struct nlattr *attr, struct nf_conn *ct,
2854 			     u32 portid, u32 report)
2855 {
2856 	struct nlattr *cda[CTA_EXPECT_MAX+1];
2857 	struct nf_conntrack_tuple tuple, mask;
2858 	struct nf_conntrack_helper *helper = NULL;
2859 	struct nf_conntrack_expect *exp;
2860 	int err;
2861 
2862 	err = nla_parse_nested_deprecated(cda, CTA_EXPECT_MAX, attr,
2863 					  exp_nla_policy, NULL);
2864 	if (err < 0)
2865 		return err;
2866 
2867 	err = ctnetlink_glue_exp_parse((const struct nlattr * const *)cda,
2868 				       ct, &tuple, &mask);
2869 	if (err < 0)
2870 		return err;
2871 
2872 	if (cda[CTA_EXPECT_HELP_NAME]) {
2873 		const char *helpname = nla_data(cda[CTA_EXPECT_HELP_NAME]);
2874 
2875 		helper = __nf_conntrack_helper_find(helpname, nf_ct_l3num(ct),
2876 						    nf_ct_protonum(ct));
2877 		if (helper == NULL)
2878 			return -EOPNOTSUPP;
2879 	}
2880 
2881 	exp = ctnetlink_alloc_expect((const struct nlattr * const *)cda, ct,
2882 				     helper, &tuple, &mask);
2883 	if (IS_ERR(exp))
2884 		return PTR_ERR(exp);
2885 
2886 	err = nf_ct_expect_related_report(exp, portid, report, 0);
2887 	nf_ct_expect_put(exp);
2888 	return err;
2889 }
2890 
ctnetlink_glue_seqadj(struct sk_buff * skb,struct nf_conn * ct,enum ip_conntrack_info ctinfo,int diff)2891 static void ctnetlink_glue_seqadj(struct sk_buff *skb, struct nf_conn *ct,
2892 				  enum ip_conntrack_info ctinfo, int diff)
2893 {
2894 	if (!(ct->status & IPS_NAT_MASK))
2895 		return;
2896 
2897 	nf_ct_tcp_seqadj_set(skb, ct, ctinfo, diff);
2898 }
2899 
2900 static struct nfnl_ct_hook ctnetlink_glue_hook = {
2901 	.get_ct		= ctnetlink_glue_get_ct,
2902 	.build_size	= ctnetlink_glue_build_size,
2903 	.build		= ctnetlink_glue_build,
2904 	.parse		= ctnetlink_glue_parse,
2905 	.attach_expect	= ctnetlink_glue_attach_expect,
2906 	.seq_adjust	= ctnetlink_glue_seqadj,
2907 };
2908 #endif /* CONFIG_NETFILTER_NETLINK_GLUE_CT */
2909 
2910 /***********************************************************************
2911  * EXPECT
2912  ***********************************************************************/
2913 
ctnetlink_exp_dump_tuple(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple,u32 type)2914 static int ctnetlink_exp_dump_tuple(struct sk_buff *skb,
2915 				    const struct nf_conntrack_tuple *tuple,
2916 				    u32 type)
2917 {
2918 	struct nlattr *nest_parms;
2919 
2920 	nest_parms = nla_nest_start(skb, type);
2921 	if (!nest_parms)
2922 		goto nla_put_failure;
2923 	if (ctnetlink_dump_tuples(skb, tuple) < 0)
2924 		goto nla_put_failure;
2925 	nla_nest_end(skb, nest_parms);
2926 
2927 	return 0;
2928 
2929 nla_put_failure:
2930 	return -1;
2931 }
2932 
ctnetlink_exp_dump_mask(struct sk_buff * skb,const struct nf_conntrack_tuple * tuple,const struct nf_conntrack_tuple_mask * mask)2933 static int ctnetlink_exp_dump_mask(struct sk_buff *skb,
2934 				   const struct nf_conntrack_tuple *tuple,
2935 				   const struct nf_conntrack_tuple_mask *mask)
2936 {
2937 	const struct nf_conntrack_l4proto *l4proto;
2938 	struct nf_conntrack_tuple m;
2939 	struct nlattr *nest_parms;
2940 	int ret;
2941 
2942 	memset(&m, 0xFF, sizeof(m));
2943 	memcpy(&m.src.u3, &mask->src.u3, sizeof(m.src.u3));
2944 	m.src.u.all = mask->src.u.all;
2945 	m.src.l3num = tuple->src.l3num;
2946 	m.dst.protonum = tuple->dst.protonum;
2947 
2948 	nest_parms = nla_nest_start(skb, CTA_EXPECT_MASK);
2949 	if (!nest_parms)
2950 		goto nla_put_failure;
2951 
2952 	rcu_read_lock();
2953 	ret = ctnetlink_dump_tuples_ip(skb, &m);
2954 	if (ret >= 0) {
2955 		l4proto = nf_ct_l4proto_find(tuple->dst.protonum);
2956 		ret = ctnetlink_dump_tuples_proto(skb, &m, l4proto);
2957 	}
2958 	rcu_read_unlock();
2959 
2960 	if (unlikely(ret < 0))
2961 		goto nla_put_failure;
2962 
2963 	nla_nest_end(skb, nest_parms);
2964 
2965 	return 0;
2966 
2967 nla_put_failure:
2968 	return -1;
2969 }
2970 
2971 #if IS_ENABLED(CONFIG_NF_NAT)
2972 static const union nf_inet_addr any_addr;
2973 #endif
2974 
nf_expect_get_id(const struct nf_conntrack_expect * exp)2975 static __be32 nf_expect_get_id(const struct nf_conntrack_expect *exp)
2976 {
2977 	static __read_mostly siphash_key_t exp_id_seed;
2978 	unsigned long a, b, c, d;
2979 
2980 	net_get_random_once(&exp_id_seed, sizeof(exp_id_seed));
2981 
2982 	a = (unsigned long)exp;
2983 	b = (unsigned long)exp->helper;
2984 	c = (unsigned long)exp->master;
2985 	d = (unsigned long)siphash(&exp->tuple, sizeof(exp->tuple), &exp_id_seed);
2986 
2987 #ifdef CONFIG_64BIT
2988 	return (__force __be32)siphash_4u64((u64)a, (u64)b, (u64)c, (u64)d, &exp_id_seed);
2989 #else
2990 	return (__force __be32)siphash_4u32((u32)a, (u32)b, (u32)c, (u32)d, &exp_id_seed);
2991 #endif
2992 }
2993 
2994 static int
ctnetlink_exp_dump_expect(struct sk_buff * skb,const struct nf_conntrack_expect * exp)2995 ctnetlink_exp_dump_expect(struct sk_buff *skb,
2996 			  const struct nf_conntrack_expect *exp)
2997 {
2998 	struct nf_conn *master = exp->master;
2999 	long timeout = ((long)exp->timeout.expires - (long)jiffies) / HZ;
3000 	struct nf_conn_help *help;
3001 #if IS_ENABLED(CONFIG_NF_NAT)
3002 	struct nlattr *nest_parms;
3003 	struct nf_conntrack_tuple nat_tuple = {};
3004 #endif
3005 	struct nf_ct_helper_expectfn *expfn;
3006 
3007 	if (timeout < 0)
3008 		timeout = 0;
3009 
3010 	if (ctnetlink_exp_dump_tuple(skb, &exp->tuple, CTA_EXPECT_TUPLE) < 0)
3011 		goto nla_put_failure;
3012 	if (ctnetlink_exp_dump_mask(skb, &exp->tuple, &exp->mask) < 0)
3013 		goto nla_put_failure;
3014 	if (ctnetlink_exp_dump_tuple(skb,
3015 				 &master->tuplehash[IP_CT_DIR_ORIGINAL].tuple,
3016 				 CTA_EXPECT_MASTER) < 0)
3017 		goto nla_put_failure;
3018 
3019 #if IS_ENABLED(CONFIG_NF_NAT)
3020 	if (!nf_inet_addr_cmp(&exp->saved_addr, &any_addr) ||
3021 	    exp->saved_proto.all) {
3022 		nest_parms = nla_nest_start(skb, CTA_EXPECT_NAT);
3023 		if (!nest_parms)
3024 			goto nla_put_failure;
3025 
3026 		if (nla_put_be32(skb, CTA_EXPECT_NAT_DIR, htonl(exp->dir)))
3027 			goto nla_put_failure;
3028 
3029 		nat_tuple.src.l3num = nf_ct_l3num(master);
3030 		nat_tuple.src.u3 = exp->saved_addr;
3031 		nat_tuple.dst.protonum = nf_ct_protonum(master);
3032 		nat_tuple.src.u = exp->saved_proto;
3033 
3034 		if (ctnetlink_exp_dump_tuple(skb, &nat_tuple,
3035 						CTA_EXPECT_NAT_TUPLE) < 0)
3036 	                goto nla_put_failure;
3037 	        nla_nest_end(skb, nest_parms);
3038 	}
3039 #endif
3040 	if (nla_put_be32(skb, CTA_EXPECT_TIMEOUT, htonl(timeout)) ||
3041 	    nla_put_be32(skb, CTA_EXPECT_ID, nf_expect_get_id(exp)) ||
3042 	    nla_put_be32(skb, CTA_EXPECT_FLAGS, htonl(exp->flags)) ||
3043 	    nla_put_be32(skb, CTA_EXPECT_CLASS, htonl(exp->class)))
3044 		goto nla_put_failure;
3045 	help = nfct_help(master);
3046 	if (help) {
3047 		struct nf_conntrack_helper *helper;
3048 
3049 		helper = rcu_dereference(help->helper);
3050 		if (helper &&
3051 		    nla_put_string(skb, CTA_EXPECT_HELP_NAME, helper->name))
3052 			goto nla_put_failure;
3053 	}
3054 	expfn = nf_ct_helper_expectfn_find_by_symbol(exp->expectfn);
3055 	if (expfn != NULL &&
3056 	    nla_put_string(skb, CTA_EXPECT_FN, expfn->name))
3057 		goto nla_put_failure;
3058 
3059 	return 0;
3060 
3061 nla_put_failure:
3062 	return -1;
3063 }
3064 
3065 static int
ctnetlink_exp_fill_info(struct sk_buff * skb,u32 portid,u32 seq,int event,const struct nf_conntrack_expect * exp)3066 ctnetlink_exp_fill_info(struct sk_buff *skb, u32 portid, u32 seq,
3067 			int event, const struct nf_conntrack_expect *exp)
3068 {
3069 	struct nlmsghdr *nlh;
3070 	unsigned int flags = portid ? NLM_F_MULTI : 0;
3071 
3072 	event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_EXP, event);
3073 	nlh = nfnl_msg_put(skb, portid, seq, event, flags,
3074 			   exp->tuple.src.l3num, NFNETLINK_V0, 0);
3075 	if (!nlh)
3076 		goto nlmsg_failure;
3077 
3078 	if (ctnetlink_exp_dump_expect(skb, exp) < 0)
3079 		goto nla_put_failure;
3080 
3081 	nlmsg_end(skb, nlh);
3082 	return skb->len;
3083 
3084 nlmsg_failure:
3085 nla_put_failure:
3086 	nlmsg_cancel(skb, nlh);
3087 	return -1;
3088 }
3089 
3090 #ifdef CONFIG_NF_CONNTRACK_EVENTS
3091 static int
ctnetlink_expect_event(unsigned int events,struct nf_exp_event * item)3092 ctnetlink_expect_event(unsigned int events, struct nf_exp_event *item)
3093 {
3094 	struct nf_conntrack_expect *exp = item->exp;
3095 	struct net *net = nf_ct_exp_net(exp);
3096 	struct nlmsghdr *nlh;
3097 	struct sk_buff *skb;
3098 	unsigned int type, group;
3099 	int flags = 0;
3100 
3101 	if (events & (1 << IPEXP_DESTROY)) {
3102 		type = IPCTNL_MSG_EXP_DELETE;
3103 		group = NFNLGRP_CONNTRACK_EXP_DESTROY;
3104 	} else if (events & (1 << IPEXP_NEW)) {
3105 		type = IPCTNL_MSG_EXP_NEW;
3106 		flags = NLM_F_CREATE|NLM_F_EXCL;
3107 		group = NFNLGRP_CONNTRACK_EXP_NEW;
3108 	} else
3109 		return 0;
3110 
3111 	if (!item->report && !nfnetlink_has_listeners(net, group))
3112 		return 0;
3113 
3114 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
3115 	if (skb == NULL)
3116 		goto errout;
3117 
3118 	type = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK_EXP, type);
3119 	nlh = nfnl_msg_put(skb, item->portid, 0, type, flags,
3120 			   exp->tuple.src.l3num, NFNETLINK_V0, 0);
3121 	if (!nlh)
3122 		goto nlmsg_failure;
3123 
3124 	if (ctnetlink_exp_dump_expect(skb, exp) < 0)
3125 		goto nla_put_failure;
3126 
3127 	nlmsg_end(skb, nlh);
3128 	nfnetlink_send(skb, net, item->portid, group, item->report, GFP_ATOMIC);
3129 	return 0;
3130 
3131 nla_put_failure:
3132 	nlmsg_cancel(skb, nlh);
3133 nlmsg_failure:
3134 	kfree_skb(skb);
3135 errout:
3136 	nfnetlink_set_err(net, 0, 0, -ENOBUFS);
3137 	return 0;
3138 }
3139 #endif
ctnetlink_exp_done(struct netlink_callback * cb)3140 static int ctnetlink_exp_done(struct netlink_callback *cb)
3141 {
3142 	if (cb->args[1])
3143 		nf_ct_expect_put((struct nf_conntrack_expect *)cb->args[1]);
3144 	return 0;
3145 }
3146 
3147 static int
ctnetlink_exp_dump_table(struct sk_buff * skb,struct netlink_callback * cb)3148 ctnetlink_exp_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
3149 {
3150 	struct net *net = sock_net(skb->sk);
3151 	struct nf_conntrack_expect *exp, *last;
3152 	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
3153 	u_int8_t l3proto = nfmsg->nfgen_family;
3154 
3155 	rcu_read_lock();
3156 	last = (struct nf_conntrack_expect *)cb->args[1];
3157 	for (; cb->args[0] < nf_ct_expect_hsize; cb->args[0]++) {
3158 restart:
3159 		hlist_for_each_entry_rcu(exp, &nf_ct_expect_hash[cb->args[0]],
3160 					 hnode) {
3161 			if (l3proto && exp->tuple.src.l3num != l3proto)
3162 				continue;
3163 
3164 			if (!net_eq(nf_ct_net(exp->master), net))
3165 				continue;
3166 
3167 			if (cb->args[1]) {
3168 				if (exp != last)
3169 					continue;
3170 				cb->args[1] = 0;
3171 			}
3172 			if (ctnetlink_exp_fill_info(skb,
3173 						    NETLINK_CB(cb->skb).portid,
3174 						    cb->nlh->nlmsg_seq,
3175 						    IPCTNL_MSG_EXP_NEW,
3176 						    exp) < 0) {
3177 				if (!refcount_inc_not_zero(&exp->use))
3178 					continue;
3179 				cb->args[1] = (unsigned long)exp;
3180 				goto out;
3181 			}
3182 		}
3183 		if (cb->args[1]) {
3184 			cb->args[1] = 0;
3185 			goto restart;
3186 		}
3187 	}
3188 out:
3189 	rcu_read_unlock();
3190 	if (last)
3191 		nf_ct_expect_put(last);
3192 
3193 	return skb->len;
3194 }
3195 
3196 static int
ctnetlink_exp_ct_dump_table(struct sk_buff * skb,struct netlink_callback * cb)3197 ctnetlink_exp_ct_dump_table(struct sk_buff *skb, struct netlink_callback *cb)
3198 {
3199 	struct nf_conntrack_expect *exp, *last;
3200 	struct nfgenmsg *nfmsg = nlmsg_data(cb->nlh);
3201 	struct nf_conn *ct = cb->data;
3202 	struct nf_conn_help *help = nfct_help(ct);
3203 	u_int8_t l3proto = nfmsg->nfgen_family;
3204 
3205 	if (cb->args[0])
3206 		return 0;
3207 
3208 	rcu_read_lock();
3209 	last = (struct nf_conntrack_expect *)cb->args[1];
3210 restart:
3211 	hlist_for_each_entry_rcu(exp, &help->expectations, lnode) {
3212 		if (l3proto && exp->tuple.src.l3num != l3proto)
3213 			continue;
3214 		if (cb->args[1]) {
3215 			if (exp != last)
3216 				continue;
3217 			cb->args[1] = 0;
3218 		}
3219 		if (ctnetlink_exp_fill_info(skb, NETLINK_CB(cb->skb).portid,
3220 					    cb->nlh->nlmsg_seq,
3221 					    IPCTNL_MSG_EXP_NEW,
3222 					    exp) < 0) {
3223 			if (!refcount_inc_not_zero(&exp->use))
3224 				continue;
3225 			cb->args[1] = (unsigned long)exp;
3226 			goto out;
3227 		}
3228 	}
3229 	if (cb->args[1]) {
3230 		cb->args[1] = 0;
3231 		goto restart;
3232 	}
3233 	cb->args[0] = 1;
3234 out:
3235 	rcu_read_unlock();
3236 	if (last)
3237 		nf_ct_expect_put(last);
3238 
3239 	return skb->len;
3240 }
3241 
ctnetlink_dump_exp_ct(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)3242 static int ctnetlink_dump_exp_ct(struct net *net, struct sock *ctnl,
3243 				 struct sk_buff *skb,
3244 				 const struct nlmsghdr *nlh,
3245 				 const struct nlattr * const cda[],
3246 				 struct netlink_ext_ack *extack)
3247 {
3248 	int err;
3249 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
3250 	u_int8_t u3 = nfmsg->nfgen_family;
3251 	struct nf_conntrack_tuple tuple;
3252 	struct nf_conntrack_tuple_hash *h;
3253 	struct nf_conn *ct;
3254 	struct nf_conntrack_zone zone;
3255 	struct netlink_dump_control c = {
3256 		.dump = ctnetlink_exp_ct_dump_table,
3257 		.done = ctnetlink_exp_done,
3258 	};
3259 
3260 	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER,
3261 				    u3, NULL);
3262 	if (err < 0)
3263 		return err;
3264 
3265 	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
3266 	if (err < 0)
3267 		return err;
3268 
3269 	h = nf_conntrack_find_get(net, &zone, &tuple);
3270 	if (!h)
3271 		return -ENOENT;
3272 
3273 	ct = nf_ct_tuplehash_to_ctrack(h);
3274 	/* No expectation linked to this connection tracking. */
3275 	if (!nfct_help(ct)) {
3276 		nf_ct_put(ct);
3277 		return 0;
3278 	}
3279 
3280 	c.data = ct;
3281 
3282 	err = netlink_dump_start(ctnl, skb, nlh, &c);
3283 	nf_ct_put(ct);
3284 
3285 	return err;
3286 }
3287 
ctnetlink_get_expect(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)3288 static int ctnetlink_get_expect(struct net *net, struct sock *ctnl,
3289 				struct sk_buff *skb, const struct nlmsghdr *nlh,
3290 				const struct nlattr * const cda[],
3291 				struct netlink_ext_ack *extack)
3292 {
3293 	struct nf_conntrack_tuple tuple;
3294 	struct nf_conntrack_expect *exp;
3295 	struct sk_buff *skb2;
3296 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
3297 	u_int8_t u3 = nfmsg->nfgen_family;
3298 	struct nf_conntrack_zone zone;
3299 	int err;
3300 
3301 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
3302 		if (cda[CTA_EXPECT_MASTER])
3303 			return ctnetlink_dump_exp_ct(net, ctnl, skb, nlh, cda,
3304 						     extack);
3305 		else {
3306 			struct netlink_dump_control c = {
3307 				.dump = ctnetlink_exp_dump_table,
3308 				.done = ctnetlink_exp_done,
3309 			};
3310 			return netlink_dump_start(ctnl, skb, nlh, &c);
3311 		}
3312 	}
3313 
3314 	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
3315 	if (err < 0)
3316 		return err;
3317 
3318 	if (cda[CTA_EXPECT_TUPLE])
3319 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE,
3320 					    u3, NULL);
3321 	else if (cda[CTA_EXPECT_MASTER])
3322 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_MASTER,
3323 					    u3, NULL);
3324 	else
3325 		return -EINVAL;
3326 
3327 	if (err < 0)
3328 		return err;
3329 
3330 	exp = nf_ct_expect_find_get(net, &zone, &tuple);
3331 	if (!exp)
3332 		return -ENOENT;
3333 
3334 	if (cda[CTA_EXPECT_ID]) {
3335 		__be32 id = nla_get_be32(cda[CTA_EXPECT_ID]);
3336 
3337 		if (id != nf_expect_get_id(exp)) {
3338 			nf_ct_expect_put(exp);
3339 			return -ENOENT;
3340 		}
3341 	}
3342 
3343 	err = -ENOMEM;
3344 	skb2 = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
3345 	if (skb2 == NULL) {
3346 		nf_ct_expect_put(exp);
3347 		goto out;
3348 	}
3349 
3350 	rcu_read_lock();
3351 	err = ctnetlink_exp_fill_info(skb2, NETLINK_CB(skb).portid,
3352 				      nlh->nlmsg_seq, IPCTNL_MSG_EXP_NEW, exp);
3353 	rcu_read_unlock();
3354 	nf_ct_expect_put(exp);
3355 	if (err <= 0)
3356 		goto free;
3357 
3358 	err = netlink_unicast(ctnl, skb2, NETLINK_CB(skb).portid, MSG_DONTWAIT);
3359 	if (err < 0)
3360 		goto out;
3361 
3362 	return 0;
3363 
3364 free:
3365 	kfree_skb(skb2);
3366 out:
3367 	/* this avoids a loop in nfnetlink. */
3368 	return err == -EAGAIN ? -ENOBUFS : err;
3369 }
3370 
expect_iter_name(struct nf_conntrack_expect * exp,void * data)3371 static bool expect_iter_name(struct nf_conntrack_expect *exp, void *data)
3372 {
3373 	const struct nf_conn_help *m_help;
3374 	const char *name = data;
3375 
3376 	m_help = nfct_help(exp->master);
3377 
3378 	return strcmp(m_help->helper->name, name) == 0;
3379 }
3380 
expect_iter_all(struct nf_conntrack_expect * exp,void * data)3381 static bool expect_iter_all(struct nf_conntrack_expect *exp, void *data)
3382 {
3383 	return true;
3384 }
3385 
ctnetlink_del_expect(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)3386 static int ctnetlink_del_expect(struct net *net, struct sock *ctnl,
3387 				struct sk_buff *skb, const struct nlmsghdr *nlh,
3388 				const struct nlattr * const cda[],
3389 				struct netlink_ext_ack *extack)
3390 {
3391 	struct nf_conntrack_expect *exp;
3392 	struct nf_conntrack_tuple tuple;
3393 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
3394 	u_int8_t u3 = nfmsg->nfgen_family;
3395 	struct nf_conntrack_zone zone;
3396 	int err;
3397 
3398 	if (cda[CTA_EXPECT_TUPLE]) {
3399 		/* delete a single expect by tuple */
3400 		err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
3401 		if (err < 0)
3402 			return err;
3403 
3404 		err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE,
3405 					    u3, NULL);
3406 		if (err < 0)
3407 			return err;
3408 
3409 		/* bump usage count to 2 */
3410 		exp = nf_ct_expect_find_get(net, &zone, &tuple);
3411 		if (!exp)
3412 			return -ENOENT;
3413 
3414 		if (cda[CTA_EXPECT_ID]) {
3415 			__be32 id = nla_get_be32(cda[CTA_EXPECT_ID]);
3416 			if (ntohl(id) != (u32)(unsigned long)exp) {
3417 				nf_ct_expect_put(exp);
3418 				return -ENOENT;
3419 			}
3420 		}
3421 
3422 		/* after list removal, usage count == 1 */
3423 		spin_lock_bh(&nf_conntrack_expect_lock);
3424 		if (del_timer(&exp->timeout)) {
3425 			nf_ct_unlink_expect_report(exp, NETLINK_CB(skb).portid,
3426 						   nlmsg_report(nlh));
3427 			nf_ct_expect_put(exp);
3428 		}
3429 		spin_unlock_bh(&nf_conntrack_expect_lock);
3430 		/* have to put what we 'get' above.
3431 		 * after this line usage count == 0 */
3432 		nf_ct_expect_put(exp);
3433 	} else if (cda[CTA_EXPECT_HELP_NAME]) {
3434 		char *name = nla_data(cda[CTA_EXPECT_HELP_NAME]);
3435 
3436 		nf_ct_expect_iterate_net(net, expect_iter_name, name,
3437 					 NETLINK_CB(skb).portid,
3438 					 nlmsg_report(nlh));
3439 	} else {
3440 		/* This basically means we have to flush everything*/
3441 		nf_ct_expect_iterate_net(net, expect_iter_all, NULL,
3442 					 NETLINK_CB(skb).portid,
3443 					 nlmsg_report(nlh));
3444 	}
3445 
3446 	return 0;
3447 }
3448 static int
ctnetlink_change_expect(struct nf_conntrack_expect * x,const struct nlattr * const cda[])3449 ctnetlink_change_expect(struct nf_conntrack_expect *x,
3450 			const struct nlattr * const cda[])
3451 {
3452 	if (cda[CTA_EXPECT_TIMEOUT]) {
3453 		if (!del_timer(&x->timeout))
3454 			return -ETIME;
3455 
3456 		x->timeout.expires = jiffies +
3457 			ntohl(nla_get_be32(cda[CTA_EXPECT_TIMEOUT])) * HZ;
3458 		add_timer(&x->timeout);
3459 	}
3460 	return 0;
3461 }
3462 
3463 #if IS_ENABLED(CONFIG_NF_NAT)
3464 static const struct nla_policy exp_nat_nla_policy[CTA_EXPECT_NAT_MAX+1] = {
3465 	[CTA_EXPECT_NAT_DIR]	= { .type = NLA_U32 },
3466 	[CTA_EXPECT_NAT_TUPLE]	= { .type = NLA_NESTED },
3467 };
3468 #endif
3469 
3470 static int
ctnetlink_parse_expect_nat(const struct nlattr * attr,struct nf_conntrack_expect * exp,u_int8_t u3)3471 ctnetlink_parse_expect_nat(const struct nlattr *attr,
3472 			   struct nf_conntrack_expect *exp,
3473 			   u_int8_t u3)
3474 {
3475 #if IS_ENABLED(CONFIG_NF_NAT)
3476 	struct nlattr *tb[CTA_EXPECT_NAT_MAX+1];
3477 	struct nf_conntrack_tuple nat_tuple = {};
3478 	int err;
3479 
3480 	err = nla_parse_nested_deprecated(tb, CTA_EXPECT_NAT_MAX, attr,
3481 					  exp_nat_nla_policy, NULL);
3482 	if (err < 0)
3483 		return err;
3484 
3485 	if (!tb[CTA_EXPECT_NAT_DIR] || !tb[CTA_EXPECT_NAT_TUPLE])
3486 		return -EINVAL;
3487 
3488 	err = ctnetlink_parse_tuple((const struct nlattr * const *)tb,
3489 				    &nat_tuple, CTA_EXPECT_NAT_TUPLE,
3490 				    u3, NULL);
3491 	if (err < 0)
3492 		return err;
3493 
3494 	exp->saved_addr = nat_tuple.src.u3;
3495 	exp->saved_proto = nat_tuple.src.u;
3496 	exp->dir = ntohl(nla_get_be32(tb[CTA_EXPECT_NAT_DIR]));
3497 
3498 	return 0;
3499 #else
3500 	return -EOPNOTSUPP;
3501 #endif
3502 }
3503 
3504 static struct nf_conntrack_expect *
ctnetlink_alloc_expect(const struct nlattr * const cda[],struct nf_conn * ct,struct nf_conntrack_helper * helper,struct nf_conntrack_tuple * tuple,struct nf_conntrack_tuple * mask)3505 ctnetlink_alloc_expect(const struct nlattr * const cda[], struct nf_conn *ct,
3506 		       struct nf_conntrack_helper *helper,
3507 		       struct nf_conntrack_tuple *tuple,
3508 		       struct nf_conntrack_tuple *mask)
3509 {
3510 	u_int32_t class = 0;
3511 	struct nf_conntrack_expect *exp;
3512 	struct nf_conn_help *help;
3513 	int err;
3514 
3515 	help = nfct_help(ct);
3516 	if (!help)
3517 		return ERR_PTR(-EOPNOTSUPP);
3518 
3519 	if (cda[CTA_EXPECT_CLASS] && helper) {
3520 		class = ntohl(nla_get_be32(cda[CTA_EXPECT_CLASS]));
3521 		if (class > helper->expect_class_max)
3522 			return ERR_PTR(-EINVAL);
3523 	}
3524 	exp = nf_ct_expect_alloc(ct);
3525 	if (!exp)
3526 		return ERR_PTR(-ENOMEM);
3527 
3528 	if (cda[CTA_EXPECT_FLAGS]) {
3529 		exp->flags = ntohl(nla_get_be32(cda[CTA_EXPECT_FLAGS]));
3530 		exp->flags &= ~NF_CT_EXPECT_USERSPACE;
3531 	} else {
3532 		exp->flags = 0;
3533 	}
3534 	if (cda[CTA_EXPECT_FN]) {
3535 		const char *name = nla_data(cda[CTA_EXPECT_FN]);
3536 		struct nf_ct_helper_expectfn *expfn;
3537 
3538 		expfn = nf_ct_helper_expectfn_find_by_name(name);
3539 		if (expfn == NULL) {
3540 			err = -EINVAL;
3541 			goto err_out;
3542 		}
3543 		exp->expectfn = expfn->expectfn;
3544 	} else
3545 		exp->expectfn = NULL;
3546 
3547 	exp->class = class;
3548 	exp->master = ct;
3549 	exp->helper = helper;
3550 	exp->tuple = *tuple;
3551 	exp->mask.src.u3 = mask->src.u3;
3552 	exp->mask.src.u.all = mask->src.u.all;
3553 
3554 	if (cda[CTA_EXPECT_NAT]) {
3555 		err = ctnetlink_parse_expect_nat(cda[CTA_EXPECT_NAT],
3556 						 exp, nf_ct_l3num(ct));
3557 		if (err < 0)
3558 			goto err_out;
3559 	}
3560 	return exp;
3561 err_out:
3562 	nf_ct_expect_put(exp);
3563 	return ERR_PTR(err);
3564 }
3565 
3566 static int
ctnetlink_create_expect(struct net * net,const struct nf_conntrack_zone * zone,const struct nlattr * const cda[],u_int8_t u3,u32 portid,int report)3567 ctnetlink_create_expect(struct net *net,
3568 			const struct nf_conntrack_zone *zone,
3569 			const struct nlattr * const cda[],
3570 			u_int8_t u3, u32 portid, int report)
3571 {
3572 	struct nf_conntrack_tuple tuple, mask, master_tuple;
3573 	struct nf_conntrack_tuple_hash *h = NULL;
3574 	struct nf_conntrack_helper *helper = NULL;
3575 	struct nf_conntrack_expect *exp;
3576 	struct nf_conn *ct;
3577 	int err;
3578 
3579 	/* caller guarantees that those three CTA_EXPECT_* exist */
3580 	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE,
3581 				    u3, NULL);
3582 	if (err < 0)
3583 		return err;
3584 	err = ctnetlink_parse_tuple(cda, &mask, CTA_EXPECT_MASK,
3585 				    u3, NULL);
3586 	if (err < 0)
3587 		return err;
3588 	err = ctnetlink_parse_tuple(cda, &master_tuple, CTA_EXPECT_MASTER,
3589 				    u3, NULL);
3590 	if (err < 0)
3591 		return err;
3592 
3593 	/* Look for master conntrack of this expectation */
3594 	h = nf_conntrack_find_get(net, zone, &master_tuple);
3595 	if (!h)
3596 		return -ENOENT;
3597 	ct = nf_ct_tuplehash_to_ctrack(h);
3598 
3599 	rcu_read_lock();
3600 	if (cda[CTA_EXPECT_HELP_NAME]) {
3601 		const char *helpname = nla_data(cda[CTA_EXPECT_HELP_NAME]);
3602 
3603 		helper = __nf_conntrack_helper_find(helpname, u3,
3604 						    nf_ct_protonum(ct));
3605 		if (helper == NULL) {
3606 			rcu_read_unlock();
3607 #ifdef CONFIG_MODULES
3608 			if (request_module("nfct-helper-%s", helpname) < 0) {
3609 				err = -EOPNOTSUPP;
3610 				goto err_ct;
3611 			}
3612 			rcu_read_lock();
3613 			helper = __nf_conntrack_helper_find(helpname, u3,
3614 							    nf_ct_protonum(ct));
3615 			if (helper) {
3616 				err = -EAGAIN;
3617 				goto err_rcu;
3618 			}
3619 			rcu_read_unlock();
3620 #endif
3621 			err = -EOPNOTSUPP;
3622 			goto err_ct;
3623 		}
3624 	}
3625 
3626 	exp = ctnetlink_alloc_expect(cda, ct, helper, &tuple, &mask);
3627 	if (IS_ERR(exp)) {
3628 		err = PTR_ERR(exp);
3629 		goto err_rcu;
3630 	}
3631 
3632 	err = nf_ct_expect_related_report(exp, portid, report, 0);
3633 	nf_ct_expect_put(exp);
3634 err_rcu:
3635 	rcu_read_unlock();
3636 err_ct:
3637 	nf_ct_put(ct);
3638 	return err;
3639 }
3640 
ctnetlink_new_expect(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)3641 static int ctnetlink_new_expect(struct net *net, struct sock *ctnl,
3642 				struct sk_buff *skb, const struct nlmsghdr *nlh,
3643 				const struct nlattr * const cda[],
3644 				struct netlink_ext_ack *extack)
3645 {
3646 	struct nf_conntrack_tuple tuple;
3647 	struct nf_conntrack_expect *exp;
3648 	struct nfgenmsg *nfmsg = nlmsg_data(nlh);
3649 	u_int8_t u3 = nfmsg->nfgen_family;
3650 	struct nf_conntrack_zone zone;
3651 	int err;
3652 
3653 	if (!cda[CTA_EXPECT_TUPLE]
3654 	    || !cda[CTA_EXPECT_MASK]
3655 	    || !cda[CTA_EXPECT_MASTER])
3656 		return -EINVAL;
3657 
3658 	err = ctnetlink_parse_zone(cda[CTA_EXPECT_ZONE], &zone);
3659 	if (err < 0)
3660 		return err;
3661 
3662 	err = ctnetlink_parse_tuple(cda, &tuple, CTA_EXPECT_TUPLE,
3663 				    u3, NULL);
3664 	if (err < 0)
3665 		return err;
3666 
3667 	spin_lock_bh(&nf_conntrack_expect_lock);
3668 	exp = __nf_ct_expect_find(net, &zone, &tuple);
3669 	if (!exp) {
3670 		spin_unlock_bh(&nf_conntrack_expect_lock);
3671 		err = -ENOENT;
3672 		if (nlh->nlmsg_flags & NLM_F_CREATE) {
3673 			err = ctnetlink_create_expect(net, &zone, cda, u3,
3674 						      NETLINK_CB(skb).portid,
3675 						      nlmsg_report(nlh));
3676 		}
3677 		return err;
3678 	}
3679 
3680 	err = -EEXIST;
3681 	if (!(nlh->nlmsg_flags & NLM_F_EXCL))
3682 		err = ctnetlink_change_expect(exp, cda);
3683 	spin_unlock_bh(&nf_conntrack_expect_lock);
3684 
3685 	return err;
3686 }
3687 
3688 static int
ctnetlink_exp_stat_fill_info(struct sk_buff * skb,u32 portid,u32 seq,int cpu,const struct ip_conntrack_stat * st)3689 ctnetlink_exp_stat_fill_info(struct sk_buff *skb, u32 portid, u32 seq, int cpu,
3690 			     const struct ip_conntrack_stat *st)
3691 {
3692 	struct nlmsghdr *nlh;
3693 	unsigned int flags = portid ? NLM_F_MULTI : 0, event;
3694 
3695 	event = nfnl_msg_type(NFNL_SUBSYS_CTNETLINK,
3696 			      IPCTNL_MSG_EXP_GET_STATS_CPU);
3697 	nlh = nfnl_msg_put(skb, portid, seq, event, flags, AF_UNSPEC,
3698 			   NFNETLINK_V0, htons(cpu));
3699 	if (!nlh)
3700 		goto nlmsg_failure;
3701 
3702 	if (nla_put_be32(skb, CTA_STATS_EXP_NEW, htonl(st->expect_new)) ||
3703 	    nla_put_be32(skb, CTA_STATS_EXP_CREATE, htonl(st->expect_create)) ||
3704 	    nla_put_be32(skb, CTA_STATS_EXP_DELETE, htonl(st->expect_delete)))
3705 		goto nla_put_failure;
3706 
3707 	nlmsg_end(skb, nlh);
3708 	return skb->len;
3709 
3710 nla_put_failure:
3711 nlmsg_failure:
3712 	nlmsg_cancel(skb, nlh);
3713 	return -1;
3714 }
3715 
3716 static int
ctnetlink_exp_stat_cpu_dump(struct sk_buff * skb,struct netlink_callback * cb)3717 ctnetlink_exp_stat_cpu_dump(struct sk_buff *skb, struct netlink_callback *cb)
3718 {
3719 	int cpu;
3720 	struct net *net = sock_net(skb->sk);
3721 
3722 	if (cb->args[0] == nr_cpu_ids)
3723 		return 0;
3724 
3725 	for (cpu = cb->args[0]; cpu < nr_cpu_ids; cpu++) {
3726 		const struct ip_conntrack_stat *st;
3727 
3728 		if (!cpu_possible(cpu))
3729 			continue;
3730 
3731 		st = per_cpu_ptr(net->ct.stat, cpu);
3732 		if (ctnetlink_exp_stat_fill_info(skb, NETLINK_CB(cb->skb).portid,
3733 						 cb->nlh->nlmsg_seq,
3734 						 cpu, st) < 0)
3735 			break;
3736 	}
3737 	cb->args[0] = cpu;
3738 
3739 	return skb->len;
3740 }
3741 
ctnetlink_stat_exp_cpu(struct net * net,struct sock * ctnl,struct sk_buff * skb,const struct nlmsghdr * nlh,const struct nlattr * const cda[],struct netlink_ext_ack * extack)3742 static int ctnetlink_stat_exp_cpu(struct net *net, struct sock *ctnl,
3743 				  struct sk_buff *skb,
3744 				  const struct nlmsghdr *nlh,
3745 				  const struct nlattr * const cda[],
3746 				  struct netlink_ext_ack *extack)
3747 {
3748 	if (nlh->nlmsg_flags & NLM_F_DUMP) {
3749 		struct netlink_dump_control c = {
3750 			.dump = ctnetlink_exp_stat_cpu_dump,
3751 		};
3752 		return netlink_dump_start(ctnl, skb, nlh, &c);
3753 	}
3754 
3755 	return 0;
3756 }
3757 
3758 #ifdef CONFIG_NF_CONNTRACK_EVENTS
3759 static struct nf_ct_event_notifier ctnl_notifier = {
3760 	.fcn = ctnetlink_conntrack_event,
3761 };
3762 
3763 static struct nf_exp_event_notifier ctnl_notifier_exp = {
3764 	.fcn = ctnetlink_expect_event,
3765 };
3766 #endif
3767 
3768 static const struct nfnl_callback ctnl_cb[IPCTNL_MSG_MAX] = {
3769 	[IPCTNL_MSG_CT_NEW]		= { .call = ctnetlink_new_conntrack,
3770 					    .attr_count = CTA_MAX,
3771 					    .policy = ct_nla_policy },
3772 	[IPCTNL_MSG_CT_GET] 		= { .call = ctnetlink_get_conntrack,
3773 					    .attr_count = CTA_MAX,
3774 					    .policy = ct_nla_policy },
3775 	[IPCTNL_MSG_CT_DELETE]  	= { .call = ctnetlink_del_conntrack,
3776 					    .attr_count = CTA_MAX,
3777 					    .policy = ct_nla_policy },
3778 	[IPCTNL_MSG_CT_GET_CTRZERO] 	= { .call = ctnetlink_get_conntrack,
3779 					    .attr_count = CTA_MAX,
3780 					    .policy = ct_nla_policy },
3781 	[IPCTNL_MSG_CT_GET_STATS_CPU]	= { .call = ctnetlink_stat_ct_cpu },
3782 	[IPCTNL_MSG_CT_GET_STATS]	= { .call = ctnetlink_stat_ct },
3783 	[IPCTNL_MSG_CT_GET_DYING]	= { .call = ctnetlink_get_ct_dying },
3784 	[IPCTNL_MSG_CT_GET_UNCONFIRMED]	= { .call = ctnetlink_get_ct_unconfirmed },
3785 };
3786 
3787 static const struct nfnl_callback ctnl_exp_cb[IPCTNL_MSG_EXP_MAX] = {
3788 	[IPCTNL_MSG_EXP_GET]		= { .call = ctnetlink_get_expect,
3789 					    .attr_count = CTA_EXPECT_MAX,
3790 					    .policy = exp_nla_policy },
3791 	[IPCTNL_MSG_EXP_NEW]		= { .call = ctnetlink_new_expect,
3792 					    .attr_count = CTA_EXPECT_MAX,
3793 					    .policy = exp_nla_policy },
3794 	[IPCTNL_MSG_EXP_DELETE]		= { .call = ctnetlink_del_expect,
3795 					    .attr_count = CTA_EXPECT_MAX,
3796 					    .policy = exp_nla_policy },
3797 	[IPCTNL_MSG_EXP_GET_STATS_CPU]	= { .call = ctnetlink_stat_exp_cpu },
3798 };
3799 
3800 static const struct nfnetlink_subsystem ctnl_subsys = {
3801 	.name				= "conntrack",
3802 	.subsys_id			= NFNL_SUBSYS_CTNETLINK,
3803 	.cb_count			= IPCTNL_MSG_MAX,
3804 	.cb				= ctnl_cb,
3805 };
3806 
3807 static const struct nfnetlink_subsystem ctnl_exp_subsys = {
3808 	.name				= "conntrack_expect",
3809 	.subsys_id			= NFNL_SUBSYS_CTNETLINK_EXP,
3810 	.cb_count			= IPCTNL_MSG_EXP_MAX,
3811 	.cb				= ctnl_exp_cb,
3812 };
3813 
3814 MODULE_ALIAS("ip_conntrack_netlink");
3815 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK);
3816 MODULE_ALIAS_NFNL_SUBSYS(NFNL_SUBSYS_CTNETLINK_EXP);
3817 
ctnetlink_net_init(struct net * net)3818 static int __net_init ctnetlink_net_init(struct net *net)
3819 {
3820 #ifdef CONFIG_NF_CONNTRACK_EVENTS
3821 	int ret;
3822 
3823 	ret = nf_conntrack_register_notifier(net, &ctnl_notifier);
3824 	if (ret < 0) {
3825 		pr_err("ctnetlink_init: cannot register notifier.\n");
3826 		goto err_out;
3827 	}
3828 
3829 	ret = nf_ct_expect_register_notifier(net, &ctnl_notifier_exp);
3830 	if (ret < 0) {
3831 		pr_err("ctnetlink_init: cannot expect register notifier.\n");
3832 		goto err_unreg_notifier;
3833 	}
3834 #endif
3835 	return 0;
3836 
3837 #ifdef CONFIG_NF_CONNTRACK_EVENTS
3838 err_unreg_notifier:
3839 	nf_conntrack_unregister_notifier(net, &ctnl_notifier);
3840 err_out:
3841 	return ret;
3842 #endif
3843 }
3844 
ctnetlink_net_exit(struct net * net)3845 static void ctnetlink_net_exit(struct net *net)
3846 {
3847 #ifdef CONFIG_NF_CONNTRACK_EVENTS
3848 	nf_ct_expect_unregister_notifier(net, &ctnl_notifier_exp);
3849 	nf_conntrack_unregister_notifier(net, &ctnl_notifier);
3850 #endif
3851 }
3852 
ctnetlink_net_exit_batch(struct list_head * net_exit_list)3853 static void __net_exit ctnetlink_net_exit_batch(struct list_head *net_exit_list)
3854 {
3855 	struct net *net;
3856 
3857 	list_for_each_entry(net, net_exit_list, exit_list)
3858 		ctnetlink_net_exit(net);
3859 
3860 	/* wait for other cpus until they are done with ctnl_notifiers */
3861 	synchronize_rcu();
3862 }
3863 
3864 static struct pernet_operations ctnetlink_net_ops = {
3865 	.init		= ctnetlink_net_init,
3866 	.exit_batch	= ctnetlink_net_exit_batch,
3867 };
3868 
ctnetlink_init(void)3869 static int __init ctnetlink_init(void)
3870 {
3871 	int ret;
3872 
3873 	ret = nfnetlink_subsys_register(&ctnl_subsys);
3874 	if (ret < 0) {
3875 		pr_err("ctnetlink_init: cannot register with nfnetlink.\n");
3876 		goto err_out;
3877 	}
3878 
3879 	ret = nfnetlink_subsys_register(&ctnl_exp_subsys);
3880 	if (ret < 0) {
3881 		pr_err("ctnetlink_init: cannot register exp with nfnetlink.\n");
3882 		goto err_unreg_subsys;
3883 	}
3884 
3885 	ret = register_pernet_subsys(&ctnetlink_net_ops);
3886 	if (ret < 0) {
3887 		pr_err("ctnetlink_init: cannot register pernet operations\n");
3888 		goto err_unreg_exp_subsys;
3889 	}
3890 #ifdef CONFIG_NETFILTER_NETLINK_GLUE_CT
3891 	/* setup interaction between nf_queue and nf_conntrack_netlink. */
3892 	RCU_INIT_POINTER(nfnl_ct_hook, &ctnetlink_glue_hook);
3893 #endif
3894 	return 0;
3895 
3896 err_unreg_exp_subsys:
3897 	nfnetlink_subsys_unregister(&ctnl_exp_subsys);
3898 err_unreg_subsys:
3899 	nfnetlink_subsys_unregister(&ctnl_subsys);
3900 err_out:
3901 	return ret;
3902 }
3903 
ctnetlink_exit(void)3904 static void __exit ctnetlink_exit(void)
3905 {
3906 	unregister_pernet_subsys(&ctnetlink_net_ops);
3907 	nfnetlink_subsys_unregister(&ctnl_exp_subsys);
3908 	nfnetlink_subsys_unregister(&ctnl_subsys);
3909 #ifdef CONFIG_NETFILTER_NETLINK_GLUE_CT
3910 	RCU_INIT_POINTER(nfnl_ct_hook, NULL);
3911 #endif
3912 	synchronize_rcu();
3913 }
3914 
3915 module_init(ctnetlink_init);
3916 module_exit(ctnetlink_exit);
3917