xref: /openbmc/linux/net/mptcp/pm_netlink.c (revision aa0dc6a7)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3  *
4  * Copyright (c) 2020, Red Hat, Inc.
5  */
6 
7 #define pr_fmt(fmt) "MPTCP: " fmt
8 
9 #include <linux/inet.h>
10 #include <linux/kernel.h>
11 #include <net/tcp.h>
12 #include <net/netns/generic.h>
13 #include <net/mptcp.h>
14 #include <net/genetlink.h>
15 #include <uapi/linux/mptcp.h>
16 
17 #include "protocol.h"
18 #include "mib.h"
19 
20 /* forward declaration */
21 static struct genl_family mptcp_genl_family;
22 
23 static int pm_nl_pernet_id;
24 
25 struct mptcp_pm_addr_entry {
26 	struct list_head	list;
27 	struct mptcp_addr_info	addr;
28 	u8			flags;
29 	int			ifindex;
30 	struct rcu_head		rcu;
31 	struct socket		*lsk;
32 };
33 
34 struct mptcp_pm_add_entry {
35 	struct list_head	list;
36 	struct mptcp_addr_info	addr;
37 	struct timer_list	add_timer;
38 	struct mptcp_sock	*sock;
39 	u8			retrans_times;
40 };
41 
42 #define MAX_ADDR_ID		255
43 #define BITMAP_SZ DIV_ROUND_UP(MAX_ADDR_ID + 1, BITS_PER_LONG)
44 
45 struct pm_nl_pernet {
46 	/* protects pernet updates */
47 	spinlock_t		lock;
48 	struct list_head	local_addr_list;
49 	unsigned int		addrs;
50 	unsigned int		add_addr_signal_max;
51 	unsigned int		add_addr_accept_max;
52 	unsigned int		local_addr_max;
53 	unsigned int		subflows_max;
54 	unsigned int		next_id;
55 	unsigned long		id_bitmap[BITMAP_SZ];
56 };
57 
58 #define MPTCP_PM_ADDR_MAX	8
59 #define ADD_ADDR_RETRANS_MAX	3
60 
61 static bool addresses_equal(const struct mptcp_addr_info *a,
62 			    struct mptcp_addr_info *b, bool use_port)
63 {
64 	bool addr_equals = false;
65 
66 	if (a->family == b->family) {
67 		if (a->family == AF_INET)
68 			addr_equals = a->addr.s_addr == b->addr.s_addr;
69 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
70 		else
71 			addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
72 	} else if (a->family == AF_INET) {
73 		if (ipv6_addr_v4mapped(&b->addr6))
74 			addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
75 	} else if (b->family == AF_INET) {
76 		if (ipv6_addr_v4mapped(&a->addr6))
77 			addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
78 #endif
79 	}
80 
81 	if (!addr_equals)
82 		return false;
83 	if (!use_port)
84 		return true;
85 
86 	return a->port == b->port;
87 }
88 
89 static bool address_zero(const struct mptcp_addr_info *addr)
90 {
91 	struct mptcp_addr_info zero;
92 
93 	memset(&zero, 0, sizeof(zero));
94 	zero.family = addr->family;
95 
96 	return addresses_equal(addr, &zero, true);
97 }
98 
99 static void local_address(const struct sock_common *skc,
100 			  struct mptcp_addr_info *addr)
101 {
102 	addr->family = skc->skc_family;
103 	addr->port = htons(skc->skc_num);
104 	if (addr->family == AF_INET)
105 		addr->addr.s_addr = skc->skc_rcv_saddr;
106 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
107 	else if (addr->family == AF_INET6)
108 		addr->addr6 = skc->skc_v6_rcv_saddr;
109 #endif
110 }
111 
112 static void remote_address(const struct sock_common *skc,
113 			   struct mptcp_addr_info *addr)
114 {
115 	addr->family = skc->skc_family;
116 	addr->port = skc->skc_dport;
117 	if (addr->family == AF_INET)
118 		addr->addr.s_addr = skc->skc_daddr;
119 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
120 	else if (addr->family == AF_INET6)
121 		addr->addr6 = skc->skc_v6_daddr;
122 #endif
123 }
124 
125 static bool lookup_subflow_by_saddr(const struct list_head *list,
126 				    struct mptcp_addr_info *saddr)
127 {
128 	struct mptcp_subflow_context *subflow;
129 	struct mptcp_addr_info cur;
130 	struct sock_common *skc;
131 
132 	list_for_each_entry(subflow, list, node) {
133 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
134 
135 		local_address(skc, &cur);
136 		if (addresses_equal(&cur, saddr, saddr->port))
137 			return true;
138 	}
139 
140 	return false;
141 }
142 
143 static bool lookup_subflow_by_daddr(const struct list_head *list,
144 				    struct mptcp_addr_info *daddr)
145 {
146 	struct mptcp_subflow_context *subflow;
147 	struct mptcp_addr_info cur;
148 	struct sock_common *skc;
149 
150 	list_for_each_entry(subflow, list, node) {
151 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
152 
153 		remote_address(skc, &cur);
154 		if (addresses_equal(&cur, daddr, daddr->port))
155 			return true;
156 	}
157 
158 	return false;
159 }
160 
161 static struct mptcp_pm_addr_entry *
162 select_local_address(const struct pm_nl_pernet *pernet,
163 		     struct mptcp_sock *msk)
164 {
165 	struct mptcp_pm_addr_entry *entry, *ret = NULL;
166 	struct sock *sk = (struct sock *)msk;
167 
168 	msk_owned_by_me(msk);
169 
170 	rcu_read_lock();
171 	__mptcp_flush_join_list(msk);
172 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
173 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
174 			continue;
175 
176 		if (entry->addr.family != sk->sk_family) {
177 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
178 			if ((entry->addr.family == AF_INET &&
179 			     !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
180 			    (sk->sk_family == AF_INET &&
181 			     !ipv6_addr_v4mapped(&entry->addr.addr6)))
182 #endif
183 				continue;
184 		}
185 
186 		/* avoid any address already in use by subflows and
187 		 * pending join
188 		 */
189 		if (!lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) {
190 			ret = entry;
191 			break;
192 		}
193 	}
194 	rcu_read_unlock();
195 	return ret;
196 }
197 
198 static struct mptcp_pm_addr_entry *
199 select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos)
200 {
201 	struct mptcp_pm_addr_entry *entry, *ret = NULL;
202 	int i = 0;
203 
204 	rcu_read_lock();
205 	/* do not keep any additional per socket state, just signal
206 	 * the address list in order.
207 	 * Note: removal from the local address list during the msk life-cycle
208 	 * can lead to additional addresses not being announced.
209 	 */
210 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
211 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
212 			continue;
213 		if (i++ == pos) {
214 			ret = entry;
215 			break;
216 		}
217 	}
218 	rcu_read_unlock();
219 	return ret;
220 }
221 
222 unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk)
223 {
224 	struct pm_nl_pernet *pernet;
225 
226 	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
227 	return READ_ONCE(pernet->add_addr_signal_max);
228 }
229 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
230 
231 unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk)
232 {
233 	struct pm_nl_pernet *pernet;
234 
235 	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
236 	return READ_ONCE(pernet->add_addr_accept_max);
237 }
238 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
239 
240 unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk)
241 {
242 	struct pm_nl_pernet *pernet;
243 
244 	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
245 	return READ_ONCE(pernet->subflows_max);
246 }
247 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
248 
249 unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk)
250 {
251 	struct pm_nl_pernet *pernet;
252 
253 	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
254 	return READ_ONCE(pernet->local_addr_max);
255 }
256 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
257 
258 static void check_work_pending(struct mptcp_sock *msk)
259 {
260 	if (msk->pm.add_addr_signaled == mptcp_pm_get_add_addr_signal_max(msk) &&
261 	    (msk->pm.local_addr_used == mptcp_pm_get_local_addr_max(msk) ||
262 	     msk->pm.subflows == mptcp_pm_get_subflows_max(msk)))
263 		WRITE_ONCE(msk->pm.work_pending, false);
264 }
265 
266 struct mptcp_pm_add_entry *
267 mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk,
268 				struct mptcp_addr_info *addr)
269 {
270 	struct mptcp_pm_add_entry *entry;
271 
272 	lockdep_assert_held(&msk->pm.lock);
273 
274 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
275 		if (addresses_equal(&entry->addr, addr, true))
276 			return entry;
277 	}
278 
279 	return NULL;
280 }
281 
282 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
283 {
284 	struct mptcp_pm_add_entry *entry;
285 	struct mptcp_addr_info saddr;
286 	bool ret = false;
287 
288 	local_address((struct sock_common *)sk, &saddr);
289 
290 	spin_lock_bh(&msk->pm.lock);
291 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
292 		if (addresses_equal(&entry->addr, &saddr, true)) {
293 			ret = true;
294 			goto out;
295 		}
296 	}
297 
298 out:
299 	spin_unlock_bh(&msk->pm.lock);
300 	return ret;
301 }
302 
303 static void mptcp_pm_add_timer(struct timer_list *timer)
304 {
305 	struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
306 	struct mptcp_sock *msk = entry->sock;
307 	struct sock *sk = (struct sock *)msk;
308 
309 	pr_debug("msk=%p", msk);
310 
311 	if (!msk)
312 		return;
313 
314 	if (inet_sk_state_load(sk) == TCP_CLOSE)
315 		return;
316 
317 	if (!entry->addr.id)
318 		return;
319 
320 	if (mptcp_pm_should_add_signal(msk)) {
321 		sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
322 		goto out;
323 	}
324 
325 	spin_lock_bh(&msk->pm.lock);
326 
327 	if (!mptcp_pm_should_add_signal(msk)) {
328 		pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
329 		mptcp_pm_announce_addr(msk, &entry->addr, false);
330 		mptcp_pm_add_addr_send_ack(msk);
331 		entry->retrans_times++;
332 	}
333 
334 	if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
335 		sk_reset_timer(sk, timer,
336 			       jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
337 
338 	spin_unlock_bh(&msk->pm.lock);
339 
340 	if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
341 		mptcp_pm_subflow_established(msk);
342 
343 out:
344 	__sock_put(sk);
345 }
346 
347 struct mptcp_pm_add_entry *
348 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
349 		       struct mptcp_addr_info *addr, bool check_id)
350 {
351 	struct mptcp_pm_add_entry *entry;
352 	struct sock *sk = (struct sock *)msk;
353 
354 	spin_lock_bh(&msk->pm.lock);
355 	entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
356 	if (entry && (!check_id || entry->addr.id == addr->id))
357 		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
358 	spin_unlock_bh(&msk->pm.lock);
359 
360 	if (entry && (!check_id || entry->addr.id == addr->id))
361 		sk_stop_timer_sync(sk, &entry->add_timer);
362 
363 	return entry;
364 }
365 
366 static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
367 				     struct mptcp_pm_addr_entry *entry)
368 {
369 	struct mptcp_pm_add_entry *add_entry = NULL;
370 	struct sock *sk = (struct sock *)msk;
371 	struct net *net = sock_net(sk);
372 
373 	lockdep_assert_held(&msk->pm.lock);
374 
375 	if (mptcp_lookup_anno_list_by_saddr(msk, &entry->addr))
376 		return false;
377 
378 	add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
379 	if (!add_entry)
380 		return false;
381 
382 	list_add(&add_entry->list, &msk->pm.anno_list);
383 
384 	add_entry->addr = entry->addr;
385 	add_entry->sock = msk;
386 	add_entry->retrans_times = 0;
387 
388 	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
389 	sk_reset_timer(sk, &add_entry->add_timer,
390 		       jiffies + mptcp_get_add_addr_timeout(net));
391 
392 	return true;
393 }
394 
395 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
396 {
397 	struct mptcp_pm_add_entry *entry, *tmp;
398 	struct sock *sk = (struct sock *)msk;
399 	LIST_HEAD(free_list);
400 
401 	pr_debug("msk=%p", msk);
402 
403 	spin_lock_bh(&msk->pm.lock);
404 	list_splice_init(&msk->pm.anno_list, &free_list);
405 	spin_unlock_bh(&msk->pm.lock);
406 
407 	list_for_each_entry_safe(entry, tmp, &free_list, list) {
408 		sk_stop_timer_sync(sk, &entry->add_timer);
409 		kfree(entry);
410 	}
411 }
412 
413 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
414 {
415 	struct sock *sk = (struct sock *)msk;
416 	struct mptcp_pm_addr_entry *local;
417 	unsigned int add_addr_signal_max;
418 	unsigned int local_addr_max;
419 	struct pm_nl_pernet *pernet;
420 	unsigned int subflows_max;
421 
422 	pernet = net_generic(sock_net(sk), pm_nl_pernet_id);
423 
424 	add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
425 	local_addr_max = mptcp_pm_get_local_addr_max(msk);
426 	subflows_max = mptcp_pm_get_subflows_max(msk);
427 
428 	pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
429 		 msk->pm.local_addr_used, local_addr_max,
430 		 msk->pm.add_addr_signaled, add_addr_signal_max,
431 		 msk->pm.subflows, subflows_max);
432 
433 	/* check first for announce */
434 	if (msk->pm.add_addr_signaled < add_addr_signal_max) {
435 		local = select_signal_address(pernet,
436 					      msk->pm.add_addr_signaled);
437 
438 		if (local) {
439 			if (mptcp_pm_alloc_anno_list(msk, local)) {
440 				msk->pm.add_addr_signaled++;
441 				mptcp_pm_announce_addr(msk, &local->addr, false);
442 				mptcp_pm_nl_addr_send_ack(msk);
443 			}
444 		} else {
445 			/* pick failed, avoid fourther attempts later */
446 			msk->pm.local_addr_used = add_addr_signal_max;
447 		}
448 
449 		check_work_pending(msk);
450 	}
451 
452 	/* check if should create a new subflow */
453 	if (msk->pm.local_addr_used < local_addr_max &&
454 	    msk->pm.subflows < subflows_max &&
455 	    !READ_ONCE(msk->pm.remote_deny_join_id0)) {
456 		local = select_local_address(pernet, msk);
457 		if (local) {
458 			struct mptcp_addr_info remote = { 0 };
459 
460 			msk->pm.local_addr_used++;
461 			msk->pm.subflows++;
462 			check_work_pending(msk);
463 			remote_address((struct sock_common *)sk, &remote);
464 			spin_unlock_bh(&msk->pm.lock);
465 			__mptcp_subflow_connect(sk, &local->addr, &remote,
466 						local->flags, local->ifindex);
467 			spin_lock_bh(&msk->pm.lock);
468 			return;
469 		}
470 
471 		/* lookup failed, avoid fourther attempts later */
472 		msk->pm.local_addr_used = local_addr_max;
473 		check_work_pending(msk);
474 	}
475 }
476 
477 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
478 {
479 	mptcp_pm_create_subflow_or_signal_addr(msk);
480 }
481 
482 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
483 {
484 	mptcp_pm_create_subflow_or_signal_addr(msk);
485 }
486 
487 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
488 {
489 	struct sock *sk = (struct sock *)msk;
490 	unsigned int add_addr_accept_max;
491 	struct mptcp_addr_info remote;
492 	struct mptcp_addr_info local;
493 	unsigned int subflows_max;
494 
495 	add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
496 	subflows_max = mptcp_pm_get_subflows_max(msk);
497 
498 	pr_debug("accepted %d:%d remote family %d",
499 		 msk->pm.add_addr_accepted, add_addr_accept_max,
500 		 msk->pm.remote.family);
501 
502 	if (lookup_subflow_by_daddr(&msk->conn_list, &msk->pm.remote))
503 		goto add_addr_echo;
504 
505 	msk->pm.add_addr_accepted++;
506 	msk->pm.subflows++;
507 	if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
508 	    msk->pm.subflows >= subflows_max)
509 		WRITE_ONCE(msk->pm.accept_addr, false);
510 
511 	/* connect to the specified remote address, using whatever
512 	 * local address the routing configuration will pick.
513 	 */
514 	remote = msk->pm.remote;
515 	if (!remote.port)
516 		remote.port = sk->sk_dport;
517 	memset(&local, 0, sizeof(local));
518 	local.family = remote.family;
519 
520 	spin_unlock_bh(&msk->pm.lock);
521 	__mptcp_subflow_connect(sk, &local, &remote, 0, 0);
522 	spin_lock_bh(&msk->pm.lock);
523 
524 add_addr_echo:
525 	mptcp_pm_announce_addr(msk, &msk->pm.remote, true);
526 	mptcp_pm_nl_addr_send_ack(msk);
527 }
528 
529 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
530 {
531 	struct mptcp_subflow_context *subflow;
532 
533 	msk_owned_by_me(msk);
534 	lockdep_assert_held(&msk->pm.lock);
535 
536 	if (!mptcp_pm_should_add_signal(msk) &&
537 	    !mptcp_pm_should_rm_signal(msk))
538 		return;
539 
540 	__mptcp_flush_join_list(msk);
541 	subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
542 	if (subflow) {
543 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
544 		bool slow;
545 
546 		spin_unlock_bh(&msk->pm.lock);
547 		pr_debug("send ack for %s%s%s",
548 			 mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr",
549 			 mptcp_pm_should_add_signal_ipv6(msk) ? " [ipv6]" : "",
550 			 mptcp_pm_should_add_signal_port(msk) ? " [port]" : "");
551 
552 		slow = lock_sock_fast(ssk);
553 		tcp_send_ack(ssk);
554 		unlock_sock_fast(ssk, slow);
555 		spin_lock_bh(&msk->pm.lock);
556 	}
557 }
558 
559 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
560 				 struct mptcp_addr_info *addr,
561 				 u8 bkup)
562 {
563 	struct mptcp_subflow_context *subflow;
564 
565 	pr_debug("bkup=%d", bkup);
566 
567 	mptcp_for_each_subflow(msk, subflow) {
568 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
569 		struct sock *sk = (struct sock *)msk;
570 		struct mptcp_addr_info local;
571 		bool slow;
572 
573 		local_address((struct sock_common *)ssk, &local);
574 		if (!addresses_equal(&local, addr, addr->port))
575 			continue;
576 
577 		subflow->backup = bkup;
578 		subflow->send_mp_prio = 1;
579 		subflow->request_bkup = bkup;
580 		__MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIOTX);
581 
582 		spin_unlock_bh(&msk->pm.lock);
583 		pr_debug("send ack for mp_prio");
584 		slow = lock_sock_fast(ssk);
585 		tcp_send_ack(ssk);
586 		unlock_sock_fast(ssk, slow);
587 		spin_lock_bh(&msk->pm.lock);
588 
589 		return 0;
590 	}
591 
592 	return -EINVAL;
593 }
594 
595 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
596 					   const struct mptcp_rm_list *rm_list,
597 					   enum linux_mptcp_mib_field rm_type)
598 {
599 	struct mptcp_subflow_context *subflow, *tmp;
600 	struct sock *sk = (struct sock *)msk;
601 	u8 i;
602 
603 	pr_debug("%s rm_list_nr %d",
604 		 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
605 
606 	msk_owned_by_me(msk);
607 
608 	if (!rm_list->nr)
609 		return;
610 
611 	if (list_empty(&msk->conn_list))
612 		return;
613 
614 	for (i = 0; i < rm_list->nr; i++) {
615 		list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
616 			struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
617 			int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
618 			u8 id = subflow->local_id;
619 
620 			if (rm_type == MPTCP_MIB_RMADDR)
621 				id = subflow->remote_id;
622 
623 			if (rm_list->ids[i] != id)
624 				continue;
625 
626 			pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u",
627 				 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
628 				 i, rm_list->ids[i], subflow->local_id, subflow->remote_id);
629 			spin_unlock_bh(&msk->pm.lock);
630 			mptcp_subflow_shutdown(sk, ssk, how);
631 			mptcp_close_ssk(sk, ssk, subflow);
632 			spin_lock_bh(&msk->pm.lock);
633 
634 			if (rm_type == MPTCP_MIB_RMADDR) {
635 				msk->pm.add_addr_accepted--;
636 				WRITE_ONCE(msk->pm.accept_addr, true);
637 			} else if (rm_type == MPTCP_MIB_RMSUBFLOW) {
638 				msk->pm.local_addr_used--;
639 			}
640 			msk->pm.subflows--;
641 			__MPTCP_INC_STATS(sock_net(sk), rm_type);
642 		}
643 	}
644 }
645 
646 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
647 {
648 	mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
649 }
650 
651 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
652 				     const struct mptcp_rm_list *rm_list)
653 {
654 	mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
655 }
656 
657 void mptcp_pm_nl_work(struct mptcp_sock *msk)
658 {
659 	struct mptcp_pm_data *pm = &msk->pm;
660 
661 	msk_owned_by_me(msk);
662 
663 	spin_lock_bh(&msk->pm.lock);
664 
665 	pr_debug("msk=%p status=%x", msk, pm->status);
666 	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
667 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
668 		mptcp_pm_nl_add_addr_received(msk);
669 	}
670 	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
671 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
672 		mptcp_pm_nl_addr_send_ack(msk);
673 	}
674 	if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
675 		pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
676 		mptcp_pm_nl_rm_addr_received(msk);
677 	}
678 	if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
679 		pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
680 		mptcp_pm_nl_fully_established(msk);
681 	}
682 	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
683 		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
684 		mptcp_pm_nl_subflow_established(msk);
685 	}
686 
687 	spin_unlock_bh(&msk->pm.lock);
688 }
689 
690 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
691 {
692 	return (entry->flags &
693 		(MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
694 		MPTCP_PM_ADDR_FLAG_SIGNAL;
695 }
696 
697 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
698 					     struct mptcp_pm_addr_entry *entry)
699 {
700 	struct mptcp_pm_addr_entry *cur;
701 	unsigned int addr_max;
702 	int ret = -EINVAL;
703 
704 	spin_lock_bh(&pernet->lock);
705 	/* to keep the code simple, don't do IDR-like allocation for address ID,
706 	 * just bail when we exceed limits
707 	 */
708 	if (pernet->next_id == MAX_ADDR_ID)
709 		pernet->next_id = 1;
710 	if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
711 		goto out;
712 	if (test_bit(entry->addr.id, pernet->id_bitmap))
713 		goto out;
714 
715 	/* do not insert duplicate address, differentiate on port only
716 	 * singled addresses
717 	 */
718 	list_for_each_entry(cur, &pernet->local_addr_list, list) {
719 		if (addresses_equal(&cur->addr, &entry->addr,
720 				    address_use_port(entry) &&
721 				    address_use_port(cur)))
722 			goto out;
723 	}
724 
725 	if (!entry->addr.id) {
726 find_next:
727 		entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
728 						    MAX_ADDR_ID + 1,
729 						    pernet->next_id);
730 		if ((!entry->addr.id || entry->addr.id > MAX_ADDR_ID) &&
731 		    pernet->next_id != 1) {
732 			pernet->next_id = 1;
733 			goto find_next;
734 		}
735 	}
736 
737 	if (!entry->addr.id || entry->addr.id > MAX_ADDR_ID)
738 		goto out;
739 
740 	__set_bit(entry->addr.id, pernet->id_bitmap);
741 	if (entry->addr.id > pernet->next_id)
742 		pernet->next_id = entry->addr.id;
743 
744 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
745 		addr_max = pernet->add_addr_signal_max;
746 		WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
747 	}
748 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
749 		addr_max = pernet->local_addr_max;
750 		WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
751 	}
752 
753 	pernet->addrs++;
754 	list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
755 	ret = entry->addr.id;
756 
757 out:
758 	spin_unlock_bh(&pernet->lock);
759 	return ret;
760 }
761 
762 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
763 					    struct mptcp_pm_addr_entry *entry)
764 {
765 	struct sockaddr_storage addr;
766 	struct mptcp_sock *msk;
767 	struct socket *ssock;
768 	int backlog = 1024;
769 	int err;
770 
771 	err = sock_create_kern(sock_net(sk), entry->addr.family,
772 			       SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
773 	if (err)
774 		return err;
775 
776 	msk = mptcp_sk(entry->lsk->sk);
777 	if (!msk) {
778 		err = -EINVAL;
779 		goto out;
780 	}
781 
782 	ssock = __mptcp_nmpc_socket(msk);
783 	if (!ssock) {
784 		err = -EINVAL;
785 		goto out;
786 	}
787 
788 	mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
789 	err = kernel_bind(ssock, (struct sockaddr *)&addr,
790 			  sizeof(struct sockaddr_in));
791 	if (err) {
792 		pr_warn("kernel_bind error, err=%d", err);
793 		goto out;
794 	}
795 
796 	err = kernel_listen(ssock, backlog);
797 	if (err) {
798 		pr_warn("kernel_listen error, err=%d", err);
799 		goto out;
800 	}
801 
802 	return 0;
803 
804 out:
805 	sock_release(entry->lsk);
806 	return err;
807 }
808 
809 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
810 {
811 	struct mptcp_pm_addr_entry *entry;
812 	struct mptcp_addr_info skc_local;
813 	struct mptcp_addr_info msk_local;
814 	struct pm_nl_pernet *pernet;
815 	int ret = -1;
816 
817 	if (WARN_ON_ONCE(!msk))
818 		return -1;
819 
820 	/* The 0 ID mapping is defined by the first subflow, copied into the msk
821 	 * addr
822 	 */
823 	local_address((struct sock_common *)msk, &msk_local);
824 	local_address((struct sock_common *)skc, &skc_local);
825 	if (addresses_equal(&msk_local, &skc_local, false))
826 		return 0;
827 
828 	if (address_zero(&skc_local))
829 		return 0;
830 
831 	pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
832 
833 	rcu_read_lock();
834 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
835 		if (addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
836 			ret = entry->addr.id;
837 			break;
838 		}
839 	}
840 	rcu_read_unlock();
841 	if (ret >= 0)
842 		return ret;
843 
844 	/* address not found, add to local list */
845 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
846 	if (!entry)
847 		return -ENOMEM;
848 
849 	entry->addr = skc_local;
850 	entry->addr.id = 0;
851 	entry->addr.port = 0;
852 	entry->ifindex = 0;
853 	entry->flags = 0;
854 	entry->lsk = NULL;
855 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
856 	if (ret < 0)
857 		kfree(entry);
858 
859 	return ret;
860 }
861 
862 void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
863 {
864 	struct mptcp_pm_data *pm = &msk->pm;
865 	bool subflows;
866 
867 	subflows = !!mptcp_pm_get_subflows_max(msk);
868 	WRITE_ONCE(pm->work_pending, (!!mptcp_pm_get_local_addr_max(msk) && subflows) ||
869 		   !!mptcp_pm_get_add_addr_signal_max(msk));
870 	WRITE_ONCE(pm->accept_addr, !!mptcp_pm_get_add_addr_accept_max(msk) && subflows);
871 	WRITE_ONCE(pm->accept_subflow, subflows);
872 }
873 
874 #define MPTCP_PM_CMD_GRP_OFFSET       0
875 #define MPTCP_PM_EV_GRP_OFFSET        1
876 
877 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
878 	[MPTCP_PM_CMD_GRP_OFFSET]	= { .name = MPTCP_PM_CMD_GRP_NAME, },
879 	[MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
880 					    .flags = GENL_UNS_ADMIN_PERM,
881 					  },
882 };
883 
884 static const struct nla_policy
885 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
886 	[MPTCP_PM_ADDR_ATTR_FAMILY]	= { .type	= NLA_U16,	},
887 	[MPTCP_PM_ADDR_ATTR_ID]		= { .type	= NLA_U8,	},
888 	[MPTCP_PM_ADDR_ATTR_ADDR4]	= { .type	= NLA_U32,	},
889 	[MPTCP_PM_ADDR_ATTR_ADDR6]	=
890 		NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
891 	[MPTCP_PM_ADDR_ATTR_PORT]	= { .type	= NLA_U16	},
892 	[MPTCP_PM_ADDR_ATTR_FLAGS]	= { .type	= NLA_U32	},
893 	[MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type	= NLA_S32	},
894 };
895 
896 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
897 	[MPTCP_PM_ATTR_ADDR]		=
898 					NLA_POLICY_NESTED(mptcp_pm_addr_policy),
899 	[MPTCP_PM_ATTR_RCV_ADD_ADDRS]	= { .type	= NLA_U32,	},
900 	[MPTCP_PM_ATTR_SUBFLOWS]	= { .type	= NLA_U32,	},
901 };
902 
903 static int mptcp_pm_family_to_addr(int family)
904 {
905 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
906 	if (family == AF_INET6)
907 		return MPTCP_PM_ADDR_ATTR_ADDR6;
908 #endif
909 	return MPTCP_PM_ADDR_ATTR_ADDR4;
910 }
911 
912 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
913 			       bool require_family,
914 			       struct mptcp_pm_addr_entry *entry)
915 {
916 	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
917 	int err, addr_addr;
918 
919 	if (!attr) {
920 		GENL_SET_ERR_MSG(info, "missing address info");
921 		return -EINVAL;
922 	}
923 
924 	/* no validation needed - was already done via nested policy */
925 	err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
926 					  mptcp_pm_addr_policy, info->extack);
927 	if (err)
928 		return err;
929 
930 	memset(entry, 0, sizeof(*entry));
931 	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
932 		if (!require_family)
933 			goto skip_family;
934 
935 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
936 				    "missing family");
937 		return -EINVAL;
938 	}
939 
940 	entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
941 	if (entry->addr.family != AF_INET
942 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
943 	    && entry->addr.family != AF_INET6
944 #endif
945 	    ) {
946 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
947 				    "unknown address family");
948 		return -EINVAL;
949 	}
950 	addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
951 	if (!tb[addr_addr]) {
952 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
953 				    "missing address data");
954 		return -EINVAL;
955 	}
956 
957 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
958 	if (entry->addr.family == AF_INET6)
959 		entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
960 	else
961 #endif
962 		entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
963 
964 skip_family:
965 	if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
966 		u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
967 
968 		entry->ifindex = val;
969 	}
970 
971 	if (tb[MPTCP_PM_ADDR_ATTR_ID])
972 		entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
973 
974 	if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
975 		entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
976 
977 	if (tb[MPTCP_PM_ADDR_ATTR_PORT]) {
978 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
979 			NL_SET_ERR_MSG_ATTR(info->extack, attr,
980 					    "flags must have signal when using port");
981 			return -EINVAL;
982 		}
983 		entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
984 	}
985 
986 	return 0;
987 }
988 
989 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
990 {
991 	return net_generic(genl_info_net(info), pm_nl_pernet_id);
992 }
993 
994 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
995 {
996 	struct mptcp_sock *msk;
997 	long s_slot = 0, s_num = 0;
998 
999 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1000 		struct sock *sk = (struct sock *)msk;
1001 
1002 		if (!READ_ONCE(msk->fully_established))
1003 			goto next;
1004 
1005 		lock_sock(sk);
1006 		spin_lock_bh(&msk->pm.lock);
1007 		mptcp_pm_create_subflow_or_signal_addr(msk);
1008 		spin_unlock_bh(&msk->pm.lock);
1009 		release_sock(sk);
1010 
1011 next:
1012 		sock_put(sk);
1013 		cond_resched();
1014 	}
1015 
1016 	return 0;
1017 }
1018 
1019 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1020 {
1021 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1022 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1023 	struct mptcp_pm_addr_entry addr, *entry;
1024 	int ret;
1025 
1026 	ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1027 	if (ret < 0)
1028 		return ret;
1029 
1030 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1031 	if (!entry) {
1032 		GENL_SET_ERR_MSG(info, "can't allocate addr");
1033 		return -ENOMEM;
1034 	}
1035 
1036 	*entry = addr;
1037 	if (entry->addr.port) {
1038 		ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1039 		if (ret) {
1040 			GENL_SET_ERR_MSG(info, "create listen socket error");
1041 			kfree(entry);
1042 			return ret;
1043 		}
1044 	}
1045 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1046 	if (ret < 0) {
1047 		GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
1048 		if (entry->lsk)
1049 			sock_release(entry->lsk);
1050 		kfree(entry);
1051 		return ret;
1052 	}
1053 
1054 	mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1055 
1056 	return 0;
1057 }
1058 
1059 static struct mptcp_pm_addr_entry *
1060 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
1061 {
1062 	struct mptcp_pm_addr_entry *entry;
1063 
1064 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
1065 		if (entry->addr.id == id)
1066 			return entry;
1067 	}
1068 	return NULL;
1069 }
1070 
1071 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1072 				      struct mptcp_addr_info *addr)
1073 {
1074 	struct mptcp_pm_add_entry *entry;
1075 
1076 	entry = mptcp_pm_del_add_timer(msk, addr, false);
1077 	if (entry) {
1078 		list_del(&entry->list);
1079 		kfree(entry);
1080 		return true;
1081 	}
1082 
1083 	return false;
1084 }
1085 
1086 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1087 				      struct mptcp_addr_info *addr,
1088 				      bool force)
1089 {
1090 	struct mptcp_rm_list list = { .nr = 0 };
1091 	bool ret;
1092 
1093 	list.ids[list.nr++] = addr->id;
1094 
1095 	ret = remove_anno_list_by_saddr(msk, addr);
1096 	if (ret || force) {
1097 		spin_lock_bh(&msk->pm.lock);
1098 		mptcp_pm_remove_addr(msk, &list);
1099 		spin_unlock_bh(&msk->pm.lock);
1100 	}
1101 	return ret;
1102 }
1103 
1104 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1105 						   struct mptcp_addr_info *addr)
1106 {
1107 	struct mptcp_sock *msk;
1108 	long s_slot = 0, s_num = 0;
1109 	struct mptcp_rm_list list = { .nr = 0 };
1110 
1111 	pr_debug("remove_id=%d", addr->id);
1112 
1113 	list.ids[list.nr++] = addr->id;
1114 
1115 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1116 		struct sock *sk = (struct sock *)msk;
1117 		bool remove_subflow;
1118 
1119 		if (list_empty(&msk->conn_list)) {
1120 			mptcp_pm_remove_anno_addr(msk, addr, false);
1121 			goto next;
1122 		}
1123 
1124 		lock_sock(sk);
1125 		remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1126 		mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
1127 		if (remove_subflow)
1128 			mptcp_pm_remove_subflow(msk, &list);
1129 		release_sock(sk);
1130 
1131 next:
1132 		sock_put(sk);
1133 		cond_resched();
1134 	}
1135 
1136 	return 0;
1137 }
1138 
1139 struct addr_entry_release_work {
1140 	struct rcu_work	rwork;
1141 	struct mptcp_pm_addr_entry *entry;
1142 };
1143 
1144 static void mptcp_pm_release_addr_entry(struct work_struct *work)
1145 {
1146 	struct addr_entry_release_work *w;
1147 	struct mptcp_pm_addr_entry *entry;
1148 
1149 	w = container_of(to_rcu_work(work), struct addr_entry_release_work, rwork);
1150 	entry = w->entry;
1151 	if (entry) {
1152 		if (entry->lsk)
1153 			sock_release(entry->lsk);
1154 		kfree(entry);
1155 	}
1156 	kfree(w);
1157 }
1158 
1159 static void mptcp_pm_free_addr_entry(struct mptcp_pm_addr_entry *entry)
1160 {
1161 	struct addr_entry_release_work *w;
1162 
1163 	w = kmalloc(sizeof(*w), GFP_ATOMIC);
1164 	if (w) {
1165 		INIT_RCU_WORK(&w->rwork, mptcp_pm_release_addr_entry);
1166 		w->entry = entry;
1167 		queue_rcu_work(system_wq, &w->rwork);
1168 	}
1169 }
1170 
1171 static int mptcp_nl_remove_id_zero_address(struct net *net,
1172 					   struct mptcp_addr_info *addr)
1173 {
1174 	struct mptcp_rm_list list = { .nr = 0 };
1175 	long s_slot = 0, s_num = 0;
1176 	struct mptcp_sock *msk;
1177 
1178 	list.ids[list.nr++] = 0;
1179 
1180 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1181 		struct sock *sk = (struct sock *)msk;
1182 		struct mptcp_addr_info msk_local;
1183 
1184 		if (list_empty(&msk->conn_list))
1185 			goto next;
1186 
1187 		local_address((struct sock_common *)msk, &msk_local);
1188 		if (!addresses_equal(&msk_local, addr, addr->port))
1189 			goto next;
1190 
1191 		lock_sock(sk);
1192 		spin_lock_bh(&msk->pm.lock);
1193 		mptcp_pm_remove_addr(msk, &list);
1194 		mptcp_pm_nl_rm_subflow_received(msk, &list);
1195 		spin_unlock_bh(&msk->pm.lock);
1196 		release_sock(sk);
1197 
1198 next:
1199 		sock_put(sk);
1200 		cond_resched();
1201 	}
1202 
1203 	return 0;
1204 }
1205 
1206 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1207 {
1208 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1209 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1210 	struct mptcp_pm_addr_entry addr, *entry;
1211 	unsigned int addr_max;
1212 	int ret;
1213 
1214 	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1215 	if (ret < 0)
1216 		return ret;
1217 
1218 	/* the zero id address is special: the first address used by the msk
1219 	 * always gets such an id, so different subflows can have different zero
1220 	 * id addresses. Additionally zero id is not accounted for in id_bitmap.
1221 	 * Let's use an 'mptcp_rm_list' instead of the common remove code.
1222 	 */
1223 	if (addr.addr.id == 0)
1224 		return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1225 
1226 	spin_lock_bh(&pernet->lock);
1227 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
1228 	if (!entry) {
1229 		GENL_SET_ERR_MSG(info, "address not found");
1230 		spin_unlock_bh(&pernet->lock);
1231 		return -EINVAL;
1232 	}
1233 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1234 		addr_max = pernet->add_addr_signal_max;
1235 		WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1236 	}
1237 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1238 		addr_max = pernet->local_addr_max;
1239 		WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1240 	}
1241 
1242 	pernet->addrs--;
1243 	list_del_rcu(&entry->list);
1244 	__clear_bit(entry->addr.id, pernet->id_bitmap);
1245 	spin_unlock_bh(&pernet->lock);
1246 
1247 	mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
1248 	mptcp_pm_free_addr_entry(entry);
1249 
1250 	return ret;
1251 }
1252 
1253 static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1254 					       struct list_head *rm_list)
1255 {
1256 	struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1257 	struct mptcp_pm_addr_entry *entry;
1258 
1259 	list_for_each_entry(entry, rm_list, list) {
1260 		if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
1261 		    alist.nr < MPTCP_RM_IDS_MAX &&
1262 		    slist.nr < MPTCP_RM_IDS_MAX) {
1263 			alist.ids[alist.nr++] = entry->addr.id;
1264 			slist.ids[slist.nr++] = entry->addr.id;
1265 		} else if (remove_anno_list_by_saddr(msk, &entry->addr) &&
1266 			 alist.nr < MPTCP_RM_IDS_MAX) {
1267 			alist.ids[alist.nr++] = entry->addr.id;
1268 		}
1269 	}
1270 
1271 	if (alist.nr) {
1272 		spin_lock_bh(&msk->pm.lock);
1273 		mptcp_pm_remove_addr(msk, &alist);
1274 		spin_unlock_bh(&msk->pm.lock);
1275 	}
1276 	if (slist.nr)
1277 		mptcp_pm_remove_subflow(msk, &slist);
1278 }
1279 
1280 static void mptcp_nl_remove_addrs_list(struct net *net,
1281 				       struct list_head *rm_list)
1282 {
1283 	long s_slot = 0, s_num = 0;
1284 	struct mptcp_sock *msk;
1285 
1286 	if (list_empty(rm_list))
1287 		return;
1288 
1289 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1290 		struct sock *sk = (struct sock *)msk;
1291 
1292 		lock_sock(sk);
1293 		mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1294 		release_sock(sk);
1295 
1296 		sock_put(sk);
1297 		cond_resched();
1298 	}
1299 }
1300 
1301 static void __flush_addrs(struct list_head *list)
1302 {
1303 	while (!list_empty(list)) {
1304 		struct mptcp_pm_addr_entry *cur;
1305 
1306 		cur = list_entry(list->next,
1307 				 struct mptcp_pm_addr_entry, list);
1308 		list_del_rcu(&cur->list);
1309 		mptcp_pm_free_addr_entry(cur);
1310 	}
1311 }
1312 
1313 static void __reset_counters(struct pm_nl_pernet *pernet)
1314 {
1315 	WRITE_ONCE(pernet->add_addr_signal_max, 0);
1316 	WRITE_ONCE(pernet->add_addr_accept_max, 0);
1317 	WRITE_ONCE(pernet->local_addr_max, 0);
1318 	pernet->addrs = 0;
1319 }
1320 
1321 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1322 {
1323 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1324 	LIST_HEAD(free_list);
1325 
1326 	spin_lock_bh(&pernet->lock);
1327 	list_splice_init(&pernet->local_addr_list, &free_list);
1328 	__reset_counters(pernet);
1329 	pernet->next_id = 1;
1330 	bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
1331 	spin_unlock_bh(&pernet->lock);
1332 	mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1333 	__flush_addrs(&free_list);
1334 	return 0;
1335 }
1336 
1337 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1338 			      struct mptcp_pm_addr_entry *entry)
1339 {
1340 	struct mptcp_addr_info *addr = &entry->addr;
1341 	struct nlattr *attr;
1342 
1343 	attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1344 	if (!attr)
1345 		return -EMSGSIZE;
1346 
1347 	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1348 		goto nla_put_failure;
1349 	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1350 		goto nla_put_failure;
1351 	if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1352 		goto nla_put_failure;
1353 	if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1354 		goto nla_put_failure;
1355 	if (entry->ifindex &&
1356 	    nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1357 		goto nla_put_failure;
1358 
1359 	if (addr->family == AF_INET &&
1360 	    nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1361 			    addr->addr.s_addr))
1362 		goto nla_put_failure;
1363 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1364 	else if (addr->family == AF_INET6 &&
1365 		 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1366 		goto nla_put_failure;
1367 #endif
1368 	nla_nest_end(skb, attr);
1369 	return 0;
1370 
1371 nla_put_failure:
1372 	nla_nest_cancel(skb, attr);
1373 	return -EMSGSIZE;
1374 }
1375 
1376 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1377 {
1378 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1379 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1380 	struct mptcp_pm_addr_entry addr, *entry;
1381 	struct sk_buff *msg;
1382 	void *reply;
1383 	int ret;
1384 
1385 	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1386 	if (ret < 0)
1387 		return ret;
1388 
1389 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1390 	if (!msg)
1391 		return -ENOMEM;
1392 
1393 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1394 				  info->genlhdr->cmd);
1395 	if (!reply) {
1396 		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1397 		ret = -EMSGSIZE;
1398 		goto fail;
1399 	}
1400 
1401 	spin_lock_bh(&pernet->lock);
1402 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
1403 	if (!entry) {
1404 		GENL_SET_ERR_MSG(info, "address not found");
1405 		ret = -EINVAL;
1406 		goto unlock_fail;
1407 	}
1408 
1409 	ret = mptcp_nl_fill_addr(msg, entry);
1410 	if (ret)
1411 		goto unlock_fail;
1412 
1413 	genlmsg_end(msg, reply);
1414 	ret = genlmsg_reply(msg, info);
1415 	spin_unlock_bh(&pernet->lock);
1416 	return ret;
1417 
1418 unlock_fail:
1419 	spin_unlock_bh(&pernet->lock);
1420 
1421 fail:
1422 	nlmsg_free(msg);
1423 	return ret;
1424 }
1425 
1426 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1427 				   struct netlink_callback *cb)
1428 {
1429 	struct net *net = sock_net(msg->sk);
1430 	struct mptcp_pm_addr_entry *entry;
1431 	struct pm_nl_pernet *pernet;
1432 	int id = cb->args[0];
1433 	void *hdr;
1434 	int i;
1435 
1436 	pernet = net_generic(net, pm_nl_pernet_id);
1437 
1438 	spin_lock_bh(&pernet->lock);
1439 	for (i = id; i < MAX_ADDR_ID + 1; i++) {
1440 		if (test_bit(i, pernet->id_bitmap)) {
1441 			entry = __lookup_addr_by_id(pernet, i);
1442 			if (!entry)
1443 				break;
1444 
1445 			if (entry->addr.id <= id)
1446 				continue;
1447 
1448 			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1449 					  cb->nlh->nlmsg_seq, &mptcp_genl_family,
1450 					  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1451 			if (!hdr)
1452 				break;
1453 
1454 			if (mptcp_nl_fill_addr(msg, entry) < 0) {
1455 				genlmsg_cancel(msg, hdr);
1456 				break;
1457 			}
1458 
1459 			id = entry->addr.id;
1460 			genlmsg_end(msg, hdr);
1461 		}
1462 	}
1463 	spin_unlock_bh(&pernet->lock);
1464 
1465 	cb->args[0] = id;
1466 	return msg->len;
1467 }
1468 
1469 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1470 {
1471 	struct nlattr *attr = info->attrs[id];
1472 
1473 	if (!attr)
1474 		return 0;
1475 
1476 	*limit = nla_get_u32(attr);
1477 	if (*limit > MPTCP_PM_ADDR_MAX) {
1478 		GENL_SET_ERR_MSG(info, "limit greater than maximum");
1479 		return -EINVAL;
1480 	}
1481 	return 0;
1482 }
1483 
1484 static int
1485 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1486 {
1487 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1488 	unsigned int rcv_addrs, subflows;
1489 	int ret;
1490 
1491 	spin_lock_bh(&pernet->lock);
1492 	rcv_addrs = pernet->add_addr_accept_max;
1493 	ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1494 	if (ret)
1495 		goto unlock;
1496 
1497 	subflows = pernet->subflows_max;
1498 	ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1499 	if (ret)
1500 		goto unlock;
1501 
1502 	WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1503 	WRITE_ONCE(pernet->subflows_max, subflows);
1504 
1505 unlock:
1506 	spin_unlock_bh(&pernet->lock);
1507 	return ret;
1508 }
1509 
1510 static int
1511 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1512 {
1513 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1514 	struct sk_buff *msg;
1515 	void *reply;
1516 
1517 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1518 	if (!msg)
1519 		return -ENOMEM;
1520 
1521 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1522 				  MPTCP_PM_CMD_GET_LIMITS);
1523 	if (!reply)
1524 		goto fail;
1525 
1526 	if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1527 			READ_ONCE(pernet->add_addr_accept_max)))
1528 		goto fail;
1529 
1530 	if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1531 			READ_ONCE(pernet->subflows_max)))
1532 		goto fail;
1533 
1534 	genlmsg_end(msg, reply);
1535 	return genlmsg_reply(msg, info);
1536 
1537 fail:
1538 	GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1539 	nlmsg_free(msg);
1540 	return -EMSGSIZE;
1541 }
1542 
1543 static int mptcp_nl_addr_backup(struct net *net,
1544 				struct mptcp_addr_info *addr,
1545 				u8 bkup)
1546 {
1547 	long s_slot = 0, s_num = 0;
1548 	struct mptcp_sock *msk;
1549 	int ret = -EINVAL;
1550 
1551 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1552 		struct sock *sk = (struct sock *)msk;
1553 
1554 		if (list_empty(&msk->conn_list))
1555 			goto next;
1556 
1557 		lock_sock(sk);
1558 		spin_lock_bh(&msk->pm.lock);
1559 		ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
1560 		spin_unlock_bh(&msk->pm.lock);
1561 		release_sock(sk);
1562 
1563 next:
1564 		sock_put(sk);
1565 		cond_resched();
1566 	}
1567 
1568 	return ret;
1569 }
1570 
1571 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
1572 {
1573 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1574 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1575 	struct mptcp_pm_addr_entry addr, *entry;
1576 	struct net *net = sock_net(skb->sk);
1577 	u8 bkup = 0;
1578 	int ret;
1579 
1580 	ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1581 	if (ret < 0)
1582 		return ret;
1583 
1584 	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1585 		bkup = 1;
1586 
1587 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
1588 		if (addresses_equal(&entry->addr, &addr.addr, true)) {
1589 			ret = mptcp_nl_addr_backup(net, &entry->addr, bkup);
1590 			if (ret)
1591 				return ret;
1592 
1593 			if (bkup)
1594 				entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
1595 			else
1596 				entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
1597 		}
1598 	}
1599 
1600 	return 0;
1601 }
1602 
1603 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1604 {
1605 	genlmsg_multicast_netns(&mptcp_genl_family, net,
1606 				nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1607 }
1608 
1609 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1610 {
1611 	const struct inet_sock *issk = inet_sk(ssk);
1612 	const struct mptcp_subflow_context *sf;
1613 
1614 	if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1615 		return -EMSGSIZE;
1616 
1617 	switch (ssk->sk_family) {
1618 	case AF_INET:
1619 		if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1620 			return -EMSGSIZE;
1621 		if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1622 			return -EMSGSIZE;
1623 		break;
1624 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1625 	case AF_INET6: {
1626 		const struct ipv6_pinfo *np = inet6_sk(ssk);
1627 
1628 		if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1629 			return -EMSGSIZE;
1630 		if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1631 			return -EMSGSIZE;
1632 		break;
1633 	}
1634 #endif
1635 	default:
1636 		WARN_ON_ONCE(1);
1637 		return -EMSGSIZE;
1638 	}
1639 
1640 	if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1641 		return -EMSGSIZE;
1642 	if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
1643 		return -EMSGSIZE;
1644 
1645 	sf = mptcp_subflow_ctx(ssk);
1646 	if (WARN_ON_ONCE(!sf))
1647 		return -EINVAL;
1648 
1649 	if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id))
1650 		return -EMSGSIZE;
1651 
1652 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
1653 		return -EMSGSIZE;
1654 
1655 	return 0;
1656 }
1657 
1658 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
1659 					 const struct mptcp_sock *msk,
1660 					 const struct sock *ssk)
1661 {
1662 	const struct sock *sk = (const struct sock *)msk;
1663 	const struct mptcp_subflow_context *sf;
1664 	u8 sk_err;
1665 
1666 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1667 		return -EMSGSIZE;
1668 
1669 	if (mptcp_event_add_subflow(skb, ssk))
1670 		return -EMSGSIZE;
1671 
1672 	sf = mptcp_subflow_ctx(ssk);
1673 	if (WARN_ON_ONCE(!sf))
1674 		return -EINVAL;
1675 
1676 	if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
1677 		return -EMSGSIZE;
1678 
1679 	if (ssk->sk_bound_dev_if &&
1680 	    nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
1681 		return -EMSGSIZE;
1682 
1683 	sk_err = ssk->sk_err;
1684 	if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
1685 	    nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
1686 		return -EMSGSIZE;
1687 
1688 	return 0;
1689 }
1690 
1691 static int mptcp_event_sub_established(struct sk_buff *skb,
1692 				       const struct mptcp_sock *msk,
1693 				       const struct sock *ssk)
1694 {
1695 	return mptcp_event_put_token_and_ssk(skb, msk, ssk);
1696 }
1697 
1698 static int mptcp_event_sub_closed(struct sk_buff *skb,
1699 				  const struct mptcp_sock *msk,
1700 				  const struct sock *ssk)
1701 {
1702 	const struct mptcp_subflow_context *sf;
1703 
1704 	if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
1705 		return -EMSGSIZE;
1706 
1707 	sf = mptcp_subflow_ctx(ssk);
1708 	if (!sf->reset_seen)
1709 		return 0;
1710 
1711 	if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
1712 		return -EMSGSIZE;
1713 
1714 	if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
1715 		return -EMSGSIZE;
1716 
1717 	return 0;
1718 }
1719 
1720 static int mptcp_event_created(struct sk_buff *skb,
1721 			       const struct mptcp_sock *msk,
1722 			       const struct sock *ssk)
1723 {
1724 	int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
1725 
1726 	if (err)
1727 		return err;
1728 
1729 	return mptcp_event_add_subflow(skb, ssk);
1730 }
1731 
1732 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
1733 {
1734 	struct net *net = sock_net((const struct sock *)msk);
1735 	struct nlmsghdr *nlh;
1736 	struct sk_buff *skb;
1737 
1738 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1739 		return;
1740 
1741 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1742 	if (!skb)
1743 		return;
1744 
1745 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
1746 	if (!nlh)
1747 		goto nla_put_failure;
1748 
1749 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1750 		goto nla_put_failure;
1751 
1752 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
1753 		goto nla_put_failure;
1754 
1755 	genlmsg_end(skb, nlh);
1756 	mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1757 	return;
1758 
1759 nla_put_failure:
1760 	kfree_skb(skb);
1761 }
1762 
1763 void mptcp_event_addr_announced(const struct mptcp_sock *msk,
1764 				const struct mptcp_addr_info *info)
1765 {
1766 	struct net *net = sock_net((const struct sock *)msk);
1767 	struct nlmsghdr *nlh;
1768 	struct sk_buff *skb;
1769 
1770 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1771 		return;
1772 
1773 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1774 	if (!skb)
1775 		return;
1776 
1777 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
1778 			  MPTCP_EVENT_ANNOUNCED);
1779 	if (!nlh)
1780 		goto nla_put_failure;
1781 
1782 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1783 		goto nla_put_failure;
1784 
1785 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
1786 		goto nla_put_failure;
1787 
1788 	if (nla_put_be16(skb, MPTCP_ATTR_DPORT, info->port))
1789 		goto nla_put_failure;
1790 
1791 	switch (info->family) {
1792 	case AF_INET:
1793 		if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
1794 			goto nla_put_failure;
1795 		break;
1796 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1797 	case AF_INET6:
1798 		if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
1799 			goto nla_put_failure;
1800 		break;
1801 #endif
1802 	default:
1803 		WARN_ON_ONCE(1);
1804 		goto nla_put_failure;
1805 	}
1806 
1807 	genlmsg_end(skb, nlh);
1808 	mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1809 	return;
1810 
1811 nla_put_failure:
1812 	kfree_skb(skb);
1813 }
1814 
1815 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
1816 		 const struct sock *ssk, gfp_t gfp)
1817 {
1818 	struct net *net = sock_net((const struct sock *)msk);
1819 	struct nlmsghdr *nlh;
1820 	struct sk_buff *skb;
1821 
1822 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1823 		return;
1824 
1825 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
1826 	if (!skb)
1827 		return;
1828 
1829 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
1830 	if (!nlh)
1831 		goto nla_put_failure;
1832 
1833 	switch (type) {
1834 	case MPTCP_EVENT_UNSPEC:
1835 		WARN_ON_ONCE(1);
1836 		break;
1837 	case MPTCP_EVENT_CREATED:
1838 	case MPTCP_EVENT_ESTABLISHED:
1839 		if (mptcp_event_created(skb, msk, ssk) < 0)
1840 			goto nla_put_failure;
1841 		break;
1842 	case MPTCP_EVENT_CLOSED:
1843 		if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
1844 			goto nla_put_failure;
1845 		break;
1846 	case MPTCP_EVENT_ANNOUNCED:
1847 	case MPTCP_EVENT_REMOVED:
1848 		/* call mptcp_event_addr_announced()/removed instead */
1849 		WARN_ON_ONCE(1);
1850 		break;
1851 	case MPTCP_EVENT_SUB_ESTABLISHED:
1852 	case MPTCP_EVENT_SUB_PRIORITY:
1853 		if (mptcp_event_sub_established(skb, msk, ssk) < 0)
1854 			goto nla_put_failure;
1855 		break;
1856 	case MPTCP_EVENT_SUB_CLOSED:
1857 		if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
1858 			goto nla_put_failure;
1859 		break;
1860 	}
1861 
1862 	genlmsg_end(skb, nlh);
1863 	mptcp_nl_mcast_send(net, skb, gfp);
1864 	return;
1865 
1866 nla_put_failure:
1867 	kfree_skb(skb);
1868 }
1869 
1870 static const struct genl_small_ops mptcp_pm_ops[] = {
1871 	{
1872 		.cmd    = MPTCP_PM_CMD_ADD_ADDR,
1873 		.doit   = mptcp_nl_cmd_add_addr,
1874 		.flags  = GENL_ADMIN_PERM,
1875 	},
1876 	{
1877 		.cmd    = MPTCP_PM_CMD_DEL_ADDR,
1878 		.doit   = mptcp_nl_cmd_del_addr,
1879 		.flags  = GENL_ADMIN_PERM,
1880 	},
1881 	{
1882 		.cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
1883 		.doit   = mptcp_nl_cmd_flush_addrs,
1884 		.flags  = GENL_ADMIN_PERM,
1885 	},
1886 	{
1887 		.cmd    = MPTCP_PM_CMD_GET_ADDR,
1888 		.doit   = mptcp_nl_cmd_get_addr,
1889 		.dumpit   = mptcp_nl_cmd_dump_addrs,
1890 	},
1891 	{
1892 		.cmd    = MPTCP_PM_CMD_SET_LIMITS,
1893 		.doit   = mptcp_nl_cmd_set_limits,
1894 		.flags  = GENL_ADMIN_PERM,
1895 	},
1896 	{
1897 		.cmd    = MPTCP_PM_CMD_GET_LIMITS,
1898 		.doit   = mptcp_nl_cmd_get_limits,
1899 	},
1900 	{
1901 		.cmd    = MPTCP_PM_CMD_SET_FLAGS,
1902 		.doit   = mptcp_nl_cmd_set_flags,
1903 		.flags  = GENL_ADMIN_PERM,
1904 	},
1905 };
1906 
1907 static struct genl_family mptcp_genl_family __ro_after_init = {
1908 	.name		= MPTCP_PM_NAME,
1909 	.version	= MPTCP_PM_VER,
1910 	.maxattr	= MPTCP_PM_ATTR_MAX,
1911 	.policy		= mptcp_pm_policy,
1912 	.netnsok	= true,
1913 	.module		= THIS_MODULE,
1914 	.small_ops	= mptcp_pm_ops,
1915 	.n_small_ops	= ARRAY_SIZE(mptcp_pm_ops),
1916 	.mcgrps		= mptcp_pm_mcgrps,
1917 	.n_mcgrps	= ARRAY_SIZE(mptcp_pm_mcgrps),
1918 };
1919 
1920 static int __net_init pm_nl_init_net(struct net *net)
1921 {
1922 	struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1923 
1924 	INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
1925 	pernet->next_id = 1;
1926 	spin_lock_init(&pernet->lock);
1927 
1928 	/* No need to initialize other pernet fields, the struct is zeroed at
1929 	 * allocation time.
1930 	 */
1931 
1932 	return 0;
1933 }
1934 
1935 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
1936 {
1937 	struct net *net;
1938 
1939 	list_for_each_entry(net, net_list, exit_list) {
1940 		struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1941 
1942 		/* net is removed from namespace list, can't race with
1943 		 * other modifiers
1944 		 */
1945 		__flush_addrs(&pernet->local_addr_list);
1946 	}
1947 }
1948 
1949 static struct pernet_operations mptcp_pm_pernet_ops = {
1950 	.init = pm_nl_init_net,
1951 	.exit_batch = pm_nl_exit_net,
1952 	.id = &pm_nl_pernet_id,
1953 	.size = sizeof(struct pm_nl_pernet),
1954 };
1955 
1956 void __init mptcp_pm_nl_init(void)
1957 {
1958 	if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
1959 		panic("Failed to register MPTCP PM pernet subsystem.\n");
1960 
1961 	if (genl_register_family(&mptcp_genl_family))
1962 		panic("Failed to register MPTCP PM netlink family\n");
1963 }
1964