xref: /openbmc/linux/net/mptcp/pm_netlink.c (revision ff5a0b421cb23bf6b2898939ffef5b683045d9d3)
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 socket		*lsk;
31 };
32 
33 struct mptcp_pm_add_entry {
34 	struct list_head	list;
35 	struct mptcp_addr_info	addr;
36 	struct timer_list	add_timer;
37 	struct mptcp_sock	*sock;
38 	u8			retrans_times;
39 };
40 
41 #define MAX_ADDR_ID		255
42 #define BITMAP_SZ DIV_ROUND_UP(MAX_ADDR_ID + 1, BITS_PER_LONG)
43 
44 struct pm_nl_pernet {
45 	/* protects pernet updates */
46 	spinlock_t		lock;
47 	struct list_head	local_addr_list;
48 	unsigned int		addrs;
49 	unsigned int		stale_loss_cnt;
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 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
904 {
905 	struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
906 	struct sock *sk = (struct sock *)msk;
907 	unsigned int active_max_loss_cnt;
908 	struct net *net = sock_net(sk);
909 	unsigned int stale_loss_cnt;
910 	bool slow;
911 
912 	stale_loss_cnt = mptcp_stale_loss_cnt(net);
913 	if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
914 		return;
915 
916 	/* look for another available subflow not in loss state */
917 	active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
918 	mptcp_for_each_subflow(msk, iter) {
919 		if (iter != subflow && mptcp_subflow_active(iter) &&
920 		    iter->stale_count < active_max_loss_cnt) {
921 			/* we have some alternatives, try to mark this subflow as idle ...*/
922 			slow = lock_sock_fast(ssk);
923 			if (!tcp_rtx_and_write_queues_empty(ssk)) {
924 				subflow->stale = 1;
925 				__mptcp_retransmit_pending_data(sk);
926 			}
927 			unlock_sock_fast(ssk, slow);
928 
929 			/* always try to push the pending data regarless of re-injections:
930 			 * we can possibly use backup subflows now, and subflow selection
931 			 * is cheap under the msk socket lock
932 			 */
933 			__mptcp_push_pending(sk, 0);
934 			return;
935 		}
936 	}
937 }
938 
939 static int mptcp_pm_family_to_addr(int family)
940 {
941 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
942 	if (family == AF_INET6)
943 		return MPTCP_PM_ADDR_ATTR_ADDR6;
944 #endif
945 	return MPTCP_PM_ADDR_ATTR_ADDR4;
946 }
947 
948 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
949 			       bool require_family,
950 			       struct mptcp_pm_addr_entry *entry)
951 {
952 	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
953 	int err, addr_addr;
954 
955 	if (!attr) {
956 		GENL_SET_ERR_MSG(info, "missing address info");
957 		return -EINVAL;
958 	}
959 
960 	/* no validation needed - was already done via nested policy */
961 	err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
962 					  mptcp_pm_addr_policy, info->extack);
963 	if (err)
964 		return err;
965 
966 	memset(entry, 0, sizeof(*entry));
967 	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
968 		if (!require_family)
969 			goto skip_family;
970 
971 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
972 				    "missing family");
973 		return -EINVAL;
974 	}
975 
976 	entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
977 	if (entry->addr.family != AF_INET
978 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
979 	    && entry->addr.family != AF_INET6
980 #endif
981 	    ) {
982 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
983 				    "unknown address family");
984 		return -EINVAL;
985 	}
986 	addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
987 	if (!tb[addr_addr]) {
988 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
989 				    "missing address data");
990 		return -EINVAL;
991 	}
992 
993 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
994 	if (entry->addr.family == AF_INET6)
995 		entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
996 	else
997 #endif
998 		entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
999 
1000 skip_family:
1001 	if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1002 		u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1003 
1004 		entry->ifindex = val;
1005 	}
1006 
1007 	if (tb[MPTCP_PM_ADDR_ATTR_ID])
1008 		entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1009 
1010 	if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1011 		entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1012 
1013 	if (tb[MPTCP_PM_ADDR_ATTR_PORT]) {
1014 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1015 			NL_SET_ERR_MSG_ATTR(info->extack, attr,
1016 					    "flags must have signal when using port");
1017 			return -EINVAL;
1018 		}
1019 		entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1020 	}
1021 
1022 	return 0;
1023 }
1024 
1025 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1026 {
1027 	return net_generic(genl_info_net(info), pm_nl_pernet_id);
1028 }
1029 
1030 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
1031 {
1032 	struct mptcp_sock *msk;
1033 	long s_slot = 0, s_num = 0;
1034 
1035 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1036 		struct sock *sk = (struct sock *)msk;
1037 
1038 		if (!READ_ONCE(msk->fully_established))
1039 			goto next;
1040 
1041 		lock_sock(sk);
1042 		spin_lock_bh(&msk->pm.lock);
1043 		mptcp_pm_create_subflow_or_signal_addr(msk);
1044 		spin_unlock_bh(&msk->pm.lock);
1045 		release_sock(sk);
1046 
1047 next:
1048 		sock_put(sk);
1049 		cond_resched();
1050 	}
1051 
1052 	return 0;
1053 }
1054 
1055 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1056 {
1057 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1058 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1059 	struct mptcp_pm_addr_entry addr, *entry;
1060 	int ret;
1061 
1062 	ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1063 	if (ret < 0)
1064 		return ret;
1065 
1066 	entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1067 	if (!entry) {
1068 		GENL_SET_ERR_MSG(info, "can't allocate addr");
1069 		return -ENOMEM;
1070 	}
1071 
1072 	*entry = addr;
1073 	if (entry->addr.port) {
1074 		ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1075 		if (ret) {
1076 			GENL_SET_ERR_MSG(info, "create listen socket error");
1077 			kfree(entry);
1078 			return ret;
1079 		}
1080 	}
1081 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1082 	if (ret < 0) {
1083 		GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
1084 		if (entry->lsk)
1085 			sock_release(entry->lsk);
1086 		kfree(entry);
1087 		return ret;
1088 	}
1089 
1090 	mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1091 
1092 	return 0;
1093 }
1094 
1095 static struct mptcp_pm_addr_entry *
1096 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
1097 {
1098 	struct mptcp_pm_addr_entry *entry;
1099 
1100 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
1101 		if (entry->addr.id == id)
1102 			return entry;
1103 	}
1104 	return NULL;
1105 }
1106 
1107 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1108 				      struct mptcp_addr_info *addr)
1109 {
1110 	struct mptcp_pm_add_entry *entry;
1111 
1112 	entry = mptcp_pm_del_add_timer(msk, addr, false);
1113 	if (entry) {
1114 		list_del(&entry->list);
1115 		kfree(entry);
1116 		return true;
1117 	}
1118 
1119 	return false;
1120 }
1121 
1122 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1123 				      struct mptcp_addr_info *addr,
1124 				      bool force)
1125 {
1126 	struct mptcp_rm_list list = { .nr = 0 };
1127 	bool ret;
1128 
1129 	list.ids[list.nr++] = addr->id;
1130 
1131 	ret = remove_anno_list_by_saddr(msk, addr);
1132 	if (ret || force) {
1133 		spin_lock_bh(&msk->pm.lock);
1134 		mptcp_pm_remove_addr(msk, &list);
1135 		spin_unlock_bh(&msk->pm.lock);
1136 	}
1137 	return ret;
1138 }
1139 
1140 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1141 						   struct mptcp_addr_info *addr)
1142 {
1143 	struct mptcp_sock *msk;
1144 	long s_slot = 0, s_num = 0;
1145 	struct mptcp_rm_list list = { .nr = 0 };
1146 
1147 	pr_debug("remove_id=%d", addr->id);
1148 
1149 	list.ids[list.nr++] = addr->id;
1150 
1151 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1152 		struct sock *sk = (struct sock *)msk;
1153 		bool remove_subflow;
1154 
1155 		if (list_empty(&msk->conn_list)) {
1156 			mptcp_pm_remove_anno_addr(msk, addr, false);
1157 			goto next;
1158 		}
1159 
1160 		lock_sock(sk);
1161 		remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1162 		mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
1163 		if (remove_subflow)
1164 			mptcp_pm_remove_subflow(msk, &list);
1165 		release_sock(sk);
1166 
1167 next:
1168 		sock_put(sk);
1169 		cond_resched();
1170 	}
1171 
1172 	return 0;
1173 }
1174 
1175 struct addr_entry_release_work {
1176 	struct rcu_work	rwork;
1177 	struct mptcp_pm_addr_entry *entry;
1178 };
1179 
1180 static void mptcp_pm_release_addr_entry(struct work_struct *work)
1181 {
1182 	struct addr_entry_release_work *w;
1183 	struct mptcp_pm_addr_entry *entry;
1184 
1185 	w = container_of(to_rcu_work(work), struct addr_entry_release_work, rwork);
1186 	entry = w->entry;
1187 	if (entry) {
1188 		if (entry->lsk)
1189 			sock_release(entry->lsk);
1190 		kfree(entry);
1191 	}
1192 	kfree(w);
1193 }
1194 
1195 static void mptcp_pm_free_addr_entry(struct mptcp_pm_addr_entry *entry)
1196 {
1197 	struct addr_entry_release_work *w;
1198 
1199 	w = kmalloc(sizeof(*w), GFP_ATOMIC);
1200 	if (w) {
1201 		INIT_RCU_WORK(&w->rwork, mptcp_pm_release_addr_entry);
1202 		w->entry = entry;
1203 		queue_rcu_work(system_wq, &w->rwork);
1204 	}
1205 }
1206 
1207 static int mptcp_nl_remove_id_zero_address(struct net *net,
1208 					   struct mptcp_addr_info *addr)
1209 {
1210 	struct mptcp_rm_list list = { .nr = 0 };
1211 	long s_slot = 0, s_num = 0;
1212 	struct mptcp_sock *msk;
1213 
1214 	list.ids[list.nr++] = 0;
1215 
1216 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1217 		struct sock *sk = (struct sock *)msk;
1218 		struct mptcp_addr_info msk_local;
1219 
1220 		if (list_empty(&msk->conn_list))
1221 			goto next;
1222 
1223 		local_address((struct sock_common *)msk, &msk_local);
1224 		if (!addresses_equal(&msk_local, addr, addr->port))
1225 			goto next;
1226 
1227 		lock_sock(sk);
1228 		spin_lock_bh(&msk->pm.lock);
1229 		mptcp_pm_remove_addr(msk, &list);
1230 		mptcp_pm_nl_rm_subflow_received(msk, &list);
1231 		spin_unlock_bh(&msk->pm.lock);
1232 		release_sock(sk);
1233 
1234 next:
1235 		sock_put(sk);
1236 		cond_resched();
1237 	}
1238 
1239 	return 0;
1240 }
1241 
1242 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1243 {
1244 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1245 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1246 	struct mptcp_pm_addr_entry addr, *entry;
1247 	unsigned int addr_max;
1248 	int ret;
1249 
1250 	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1251 	if (ret < 0)
1252 		return ret;
1253 
1254 	/* the zero id address is special: the first address used by the msk
1255 	 * always gets such an id, so different subflows can have different zero
1256 	 * id addresses. Additionally zero id is not accounted for in id_bitmap.
1257 	 * Let's use an 'mptcp_rm_list' instead of the common remove code.
1258 	 */
1259 	if (addr.addr.id == 0)
1260 		return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1261 
1262 	spin_lock_bh(&pernet->lock);
1263 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
1264 	if (!entry) {
1265 		GENL_SET_ERR_MSG(info, "address not found");
1266 		spin_unlock_bh(&pernet->lock);
1267 		return -EINVAL;
1268 	}
1269 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1270 		addr_max = pernet->add_addr_signal_max;
1271 		WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1272 	}
1273 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1274 		addr_max = pernet->local_addr_max;
1275 		WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1276 	}
1277 
1278 	pernet->addrs--;
1279 	list_del_rcu(&entry->list);
1280 	__clear_bit(entry->addr.id, pernet->id_bitmap);
1281 	spin_unlock_bh(&pernet->lock);
1282 
1283 	mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
1284 	mptcp_pm_free_addr_entry(entry);
1285 
1286 	return ret;
1287 }
1288 
1289 static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1290 					       struct list_head *rm_list)
1291 {
1292 	struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1293 	struct mptcp_pm_addr_entry *entry;
1294 
1295 	list_for_each_entry(entry, rm_list, list) {
1296 		if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
1297 		    alist.nr < MPTCP_RM_IDS_MAX &&
1298 		    slist.nr < MPTCP_RM_IDS_MAX) {
1299 			alist.ids[alist.nr++] = entry->addr.id;
1300 			slist.ids[slist.nr++] = entry->addr.id;
1301 		} else if (remove_anno_list_by_saddr(msk, &entry->addr) &&
1302 			 alist.nr < MPTCP_RM_IDS_MAX) {
1303 			alist.ids[alist.nr++] = entry->addr.id;
1304 		}
1305 	}
1306 
1307 	if (alist.nr) {
1308 		spin_lock_bh(&msk->pm.lock);
1309 		mptcp_pm_remove_addr(msk, &alist);
1310 		spin_unlock_bh(&msk->pm.lock);
1311 	}
1312 	if (slist.nr)
1313 		mptcp_pm_remove_subflow(msk, &slist);
1314 }
1315 
1316 static void mptcp_nl_remove_addrs_list(struct net *net,
1317 				       struct list_head *rm_list)
1318 {
1319 	long s_slot = 0, s_num = 0;
1320 	struct mptcp_sock *msk;
1321 
1322 	if (list_empty(rm_list))
1323 		return;
1324 
1325 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1326 		struct sock *sk = (struct sock *)msk;
1327 
1328 		lock_sock(sk);
1329 		mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1330 		release_sock(sk);
1331 
1332 		sock_put(sk);
1333 		cond_resched();
1334 	}
1335 }
1336 
1337 static void __flush_addrs(struct list_head *list)
1338 {
1339 	while (!list_empty(list)) {
1340 		struct mptcp_pm_addr_entry *cur;
1341 
1342 		cur = list_entry(list->next,
1343 				 struct mptcp_pm_addr_entry, list);
1344 		list_del_rcu(&cur->list);
1345 		mptcp_pm_free_addr_entry(cur);
1346 	}
1347 }
1348 
1349 static void __reset_counters(struct pm_nl_pernet *pernet)
1350 {
1351 	WRITE_ONCE(pernet->add_addr_signal_max, 0);
1352 	WRITE_ONCE(pernet->add_addr_accept_max, 0);
1353 	WRITE_ONCE(pernet->local_addr_max, 0);
1354 	pernet->addrs = 0;
1355 }
1356 
1357 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1358 {
1359 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1360 	LIST_HEAD(free_list);
1361 
1362 	spin_lock_bh(&pernet->lock);
1363 	list_splice_init(&pernet->local_addr_list, &free_list);
1364 	__reset_counters(pernet);
1365 	pernet->next_id = 1;
1366 	bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
1367 	spin_unlock_bh(&pernet->lock);
1368 	mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1369 	__flush_addrs(&free_list);
1370 	return 0;
1371 }
1372 
1373 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1374 			      struct mptcp_pm_addr_entry *entry)
1375 {
1376 	struct mptcp_addr_info *addr = &entry->addr;
1377 	struct nlattr *attr;
1378 
1379 	attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1380 	if (!attr)
1381 		return -EMSGSIZE;
1382 
1383 	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1384 		goto nla_put_failure;
1385 	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1386 		goto nla_put_failure;
1387 	if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1388 		goto nla_put_failure;
1389 	if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1390 		goto nla_put_failure;
1391 	if (entry->ifindex &&
1392 	    nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1393 		goto nla_put_failure;
1394 
1395 	if (addr->family == AF_INET &&
1396 	    nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1397 			    addr->addr.s_addr))
1398 		goto nla_put_failure;
1399 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1400 	else if (addr->family == AF_INET6 &&
1401 		 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1402 		goto nla_put_failure;
1403 #endif
1404 	nla_nest_end(skb, attr);
1405 	return 0;
1406 
1407 nla_put_failure:
1408 	nla_nest_cancel(skb, attr);
1409 	return -EMSGSIZE;
1410 }
1411 
1412 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1413 {
1414 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1415 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1416 	struct mptcp_pm_addr_entry addr, *entry;
1417 	struct sk_buff *msg;
1418 	void *reply;
1419 	int ret;
1420 
1421 	ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1422 	if (ret < 0)
1423 		return ret;
1424 
1425 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1426 	if (!msg)
1427 		return -ENOMEM;
1428 
1429 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1430 				  info->genlhdr->cmd);
1431 	if (!reply) {
1432 		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1433 		ret = -EMSGSIZE;
1434 		goto fail;
1435 	}
1436 
1437 	spin_lock_bh(&pernet->lock);
1438 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
1439 	if (!entry) {
1440 		GENL_SET_ERR_MSG(info, "address not found");
1441 		ret = -EINVAL;
1442 		goto unlock_fail;
1443 	}
1444 
1445 	ret = mptcp_nl_fill_addr(msg, entry);
1446 	if (ret)
1447 		goto unlock_fail;
1448 
1449 	genlmsg_end(msg, reply);
1450 	ret = genlmsg_reply(msg, info);
1451 	spin_unlock_bh(&pernet->lock);
1452 	return ret;
1453 
1454 unlock_fail:
1455 	spin_unlock_bh(&pernet->lock);
1456 
1457 fail:
1458 	nlmsg_free(msg);
1459 	return ret;
1460 }
1461 
1462 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1463 				   struct netlink_callback *cb)
1464 {
1465 	struct net *net = sock_net(msg->sk);
1466 	struct mptcp_pm_addr_entry *entry;
1467 	struct pm_nl_pernet *pernet;
1468 	int id = cb->args[0];
1469 	void *hdr;
1470 	int i;
1471 
1472 	pernet = net_generic(net, pm_nl_pernet_id);
1473 
1474 	spin_lock_bh(&pernet->lock);
1475 	for (i = id; i < MAX_ADDR_ID + 1; i++) {
1476 		if (test_bit(i, pernet->id_bitmap)) {
1477 			entry = __lookup_addr_by_id(pernet, i);
1478 			if (!entry)
1479 				break;
1480 
1481 			if (entry->addr.id <= id)
1482 				continue;
1483 
1484 			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1485 					  cb->nlh->nlmsg_seq, &mptcp_genl_family,
1486 					  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1487 			if (!hdr)
1488 				break;
1489 
1490 			if (mptcp_nl_fill_addr(msg, entry) < 0) {
1491 				genlmsg_cancel(msg, hdr);
1492 				break;
1493 			}
1494 
1495 			id = entry->addr.id;
1496 			genlmsg_end(msg, hdr);
1497 		}
1498 	}
1499 	spin_unlock_bh(&pernet->lock);
1500 
1501 	cb->args[0] = id;
1502 	return msg->len;
1503 }
1504 
1505 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1506 {
1507 	struct nlattr *attr = info->attrs[id];
1508 
1509 	if (!attr)
1510 		return 0;
1511 
1512 	*limit = nla_get_u32(attr);
1513 	if (*limit > MPTCP_PM_ADDR_MAX) {
1514 		GENL_SET_ERR_MSG(info, "limit greater than maximum");
1515 		return -EINVAL;
1516 	}
1517 	return 0;
1518 }
1519 
1520 static int
1521 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1522 {
1523 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1524 	unsigned int rcv_addrs, subflows;
1525 	int ret;
1526 
1527 	spin_lock_bh(&pernet->lock);
1528 	rcv_addrs = pernet->add_addr_accept_max;
1529 	ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1530 	if (ret)
1531 		goto unlock;
1532 
1533 	subflows = pernet->subflows_max;
1534 	ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1535 	if (ret)
1536 		goto unlock;
1537 
1538 	WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1539 	WRITE_ONCE(pernet->subflows_max, subflows);
1540 
1541 unlock:
1542 	spin_unlock_bh(&pernet->lock);
1543 	return ret;
1544 }
1545 
1546 static int
1547 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1548 {
1549 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1550 	struct sk_buff *msg;
1551 	void *reply;
1552 
1553 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1554 	if (!msg)
1555 		return -ENOMEM;
1556 
1557 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1558 				  MPTCP_PM_CMD_GET_LIMITS);
1559 	if (!reply)
1560 		goto fail;
1561 
1562 	if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1563 			READ_ONCE(pernet->add_addr_accept_max)))
1564 		goto fail;
1565 
1566 	if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1567 			READ_ONCE(pernet->subflows_max)))
1568 		goto fail;
1569 
1570 	genlmsg_end(msg, reply);
1571 	return genlmsg_reply(msg, info);
1572 
1573 fail:
1574 	GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1575 	nlmsg_free(msg);
1576 	return -EMSGSIZE;
1577 }
1578 
1579 static int mptcp_nl_addr_backup(struct net *net,
1580 				struct mptcp_addr_info *addr,
1581 				u8 bkup)
1582 {
1583 	long s_slot = 0, s_num = 0;
1584 	struct mptcp_sock *msk;
1585 	int ret = -EINVAL;
1586 
1587 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1588 		struct sock *sk = (struct sock *)msk;
1589 
1590 		if (list_empty(&msk->conn_list))
1591 			goto next;
1592 
1593 		lock_sock(sk);
1594 		spin_lock_bh(&msk->pm.lock);
1595 		ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
1596 		spin_unlock_bh(&msk->pm.lock);
1597 		release_sock(sk);
1598 
1599 next:
1600 		sock_put(sk);
1601 		cond_resched();
1602 	}
1603 
1604 	return ret;
1605 }
1606 
1607 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
1608 {
1609 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1610 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1611 	struct mptcp_pm_addr_entry addr, *entry;
1612 	struct net *net = sock_net(skb->sk);
1613 	u8 bkup = 0;
1614 	int ret;
1615 
1616 	ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1617 	if (ret < 0)
1618 		return ret;
1619 
1620 	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1621 		bkup = 1;
1622 
1623 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
1624 		if (addresses_equal(&entry->addr, &addr.addr, true)) {
1625 			ret = mptcp_nl_addr_backup(net, &entry->addr, bkup);
1626 			if (ret)
1627 				return ret;
1628 
1629 			if (bkup)
1630 				entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
1631 			else
1632 				entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
1633 		}
1634 	}
1635 
1636 	return 0;
1637 }
1638 
1639 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1640 {
1641 	genlmsg_multicast_netns(&mptcp_genl_family, net,
1642 				nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1643 }
1644 
1645 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1646 {
1647 	const struct inet_sock *issk = inet_sk(ssk);
1648 	const struct mptcp_subflow_context *sf;
1649 
1650 	if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1651 		return -EMSGSIZE;
1652 
1653 	switch (ssk->sk_family) {
1654 	case AF_INET:
1655 		if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1656 			return -EMSGSIZE;
1657 		if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1658 			return -EMSGSIZE;
1659 		break;
1660 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1661 	case AF_INET6: {
1662 		const struct ipv6_pinfo *np = inet6_sk(ssk);
1663 
1664 		if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1665 			return -EMSGSIZE;
1666 		if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1667 			return -EMSGSIZE;
1668 		break;
1669 	}
1670 #endif
1671 	default:
1672 		WARN_ON_ONCE(1);
1673 		return -EMSGSIZE;
1674 	}
1675 
1676 	if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1677 		return -EMSGSIZE;
1678 	if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
1679 		return -EMSGSIZE;
1680 
1681 	sf = mptcp_subflow_ctx(ssk);
1682 	if (WARN_ON_ONCE(!sf))
1683 		return -EINVAL;
1684 
1685 	if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id))
1686 		return -EMSGSIZE;
1687 
1688 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
1689 		return -EMSGSIZE;
1690 
1691 	return 0;
1692 }
1693 
1694 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
1695 					 const struct mptcp_sock *msk,
1696 					 const struct sock *ssk)
1697 {
1698 	const struct sock *sk = (const struct sock *)msk;
1699 	const struct mptcp_subflow_context *sf;
1700 	u8 sk_err;
1701 
1702 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1703 		return -EMSGSIZE;
1704 
1705 	if (mptcp_event_add_subflow(skb, ssk))
1706 		return -EMSGSIZE;
1707 
1708 	sf = mptcp_subflow_ctx(ssk);
1709 	if (WARN_ON_ONCE(!sf))
1710 		return -EINVAL;
1711 
1712 	if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
1713 		return -EMSGSIZE;
1714 
1715 	if (ssk->sk_bound_dev_if &&
1716 	    nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
1717 		return -EMSGSIZE;
1718 
1719 	sk_err = ssk->sk_err;
1720 	if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
1721 	    nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
1722 		return -EMSGSIZE;
1723 
1724 	return 0;
1725 }
1726 
1727 static int mptcp_event_sub_established(struct sk_buff *skb,
1728 				       const struct mptcp_sock *msk,
1729 				       const struct sock *ssk)
1730 {
1731 	return mptcp_event_put_token_and_ssk(skb, msk, ssk);
1732 }
1733 
1734 static int mptcp_event_sub_closed(struct sk_buff *skb,
1735 				  const struct mptcp_sock *msk,
1736 				  const struct sock *ssk)
1737 {
1738 	const struct mptcp_subflow_context *sf;
1739 
1740 	if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
1741 		return -EMSGSIZE;
1742 
1743 	sf = mptcp_subflow_ctx(ssk);
1744 	if (!sf->reset_seen)
1745 		return 0;
1746 
1747 	if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
1748 		return -EMSGSIZE;
1749 
1750 	if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
1751 		return -EMSGSIZE;
1752 
1753 	return 0;
1754 }
1755 
1756 static int mptcp_event_created(struct sk_buff *skb,
1757 			       const struct mptcp_sock *msk,
1758 			       const struct sock *ssk)
1759 {
1760 	int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
1761 
1762 	if (err)
1763 		return err;
1764 
1765 	return mptcp_event_add_subflow(skb, ssk);
1766 }
1767 
1768 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
1769 {
1770 	struct net *net = sock_net((const struct sock *)msk);
1771 	struct nlmsghdr *nlh;
1772 	struct sk_buff *skb;
1773 
1774 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1775 		return;
1776 
1777 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1778 	if (!skb)
1779 		return;
1780 
1781 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
1782 	if (!nlh)
1783 		goto nla_put_failure;
1784 
1785 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1786 		goto nla_put_failure;
1787 
1788 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
1789 		goto nla_put_failure;
1790 
1791 	genlmsg_end(skb, nlh);
1792 	mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1793 	return;
1794 
1795 nla_put_failure:
1796 	kfree_skb(skb);
1797 }
1798 
1799 void mptcp_event_addr_announced(const struct mptcp_sock *msk,
1800 				const struct mptcp_addr_info *info)
1801 {
1802 	struct net *net = sock_net((const struct sock *)msk);
1803 	struct nlmsghdr *nlh;
1804 	struct sk_buff *skb;
1805 
1806 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1807 		return;
1808 
1809 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1810 	if (!skb)
1811 		return;
1812 
1813 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
1814 			  MPTCP_EVENT_ANNOUNCED);
1815 	if (!nlh)
1816 		goto nla_put_failure;
1817 
1818 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1819 		goto nla_put_failure;
1820 
1821 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
1822 		goto nla_put_failure;
1823 
1824 	if (nla_put_be16(skb, MPTCP_ATTR_DPORT, info->port))
1825 		goto nla_put_failure;
1826 
1827 	switch (info->family) {
1828 	case AF_INET:
1829 		if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
1830 			goto nla_put_failure;
1831 		break;
1832 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1833 	case AF_INET6:
1834 		if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
1835 			goto nla_put_failure;
1836 		break;
1837 #endif
1838 	default:
1839 		WARN_ON_ONCE(1);
1840 		goto nla_put_failure;
1841 	}
1842 
1843 	genlmsg_end(skb, nlh);
1844 	mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1845 	return;
1846 
1847 nla_put_failure:
1848 	kfree_skb(skb);
1849 }
1850 
1851 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
1852 		 const struct sock *ssk, gfp_t gfp)
1853 {
1854 	struct net *net = sock_net((const struct sock *)msk);
1855 	struct nlmsghdr *nlh;
1856 	struct sk_buff *skb;
1857 
1858 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1859 		return;
1860 
1861 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
1862 	if (!skb)
1863 		return;
1864 
1865 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
1866 	if (!nlh)
1867 		goto nla_put_failure;
1868 
1869 	switch (type) {
1870 	case MPTCP_EVENT_UNSPEC:
1871 		WARN_ON_ONCE(1);
1872 		break;
1873 	case MPTCP_EVENT_CREATED:
1874 	case MPTCP_EVENT_ESTABLISHED:
1875 		if (mptcp_event_created(skb, msk, ssk) < 0)
1876 			goto nla_put_failure;
1877 		break;
1878 	case MPTCP_EVENT_CLOSED:
1879 		if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
1880 			goto nla_put_failure;
1881 		break;
1882 	case MPTCP_EVENT_ANNOUNCED:
1883 	case MPTCP_EVENT_REMOVED:
1884 		/* call mptcp_event_addr_announced()/removed instead */
1885 		WARN_ON_ONCE(1);
1886 		break;
1887 	case MPTCP_EVENT_SUB_ESTABLISHED:
1888 	case MPTCP_EVENT_SUB_PRIORITY:
1889 		if (mptcp_event_sub_established(skb, msk, ssk) < 0)
1890 			goto nla_put_failure;
1891 		break;
1892 	case MPTCP_EVENT_SUB_CLOSED:
1893 		if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
1894 			goto nla_put_failure;
1895 		break;
1896 	}
1897 
1898 	genlmsg_end(skb, nlh);
1899 	mptcp_nl_mcast_send(net, skb, gfp);
1900 	return;
1901 
1902 nla_put_failure:
1903 	kfree_skb(skb);
1904 }
1905 
1906 static const struct genl_small_ops mptcp_pm_ops[] = {
1907 	{
1908 		.cmd    = MPTCP_PM_CMD_ADD_ADDR,
1909 		.doit   = mptcp_nl_cmd_add_addr,
1910 		.flags  = GENL_ADMIN_PERM,
1911 	},
1912 	{
1913 		.cmd    = MPTCP_PM_CMD_DEL_ADDR,
1914 		.doit   = mptcp_nl_cmd_del_addr,
1915 		.flags  = GENL_ADMIN_PERM,
1916 	},
1917 	{
1918 		.cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
1919 		.doit   = mptcp_nl_cmd_flush_addrs,
1920 		.flags  = GENL_ADMIN_PERM,
1921 	},
1922 	{
1923 		.cmd    = MPTCP_PM_CMD_GET_ADDR,
1924 		.doit   = mptcp_nl_cmd_get_addr,
1925 		.dumpit   = mptcp_nl_cmd_dump_addrs,
1926 	},
1927 	{
1928 		.cmd    = MPTCP_PM_CMD_SET_LIMITS,
1929 		.doit   = mptcp_nl_cmd_set_limits,
1930 		.flags  = GENL_ADMIN_PERM,
1931 	},
1932 	{
1933 		.cmd    = MPTCP_PM_CMD_GET_LIMITS,
1934 		.doit   = mptcp_nl_cmd_get_limits,
1935 	},
1936 	{
1937 		.cmd    = MPTCP_PM_CMD_SET_FLAGS,
1938 		.doit   = mptcp_nl_cmd_set_flags,
1939 		.flags  = GENL_ADMIN_PERM,
1940 	},
1941 };
1942 
1943 static struct genl_family mptcp_genl_family __ro_after_init = {
1944 	.name		= MPTCP_PM_NAME,
1945 	.version	= MPTCP_PM_VER,
1946 	.maxattr	= MPTCP_PM_ATTR_MAX,
1947 	.policy		= mptcp_pm_policy,
1948 	.netnsok	= true,
1949 	.module		= THIS_MODULE,
1950 	.small_ops	= mptcp_pm_ops,
1951 	.n_small_ops	= ARRAY_SIZE(mptcp_pm_ops),
1952 	.mcgrps		= mptcp_pm_mcgrps,
1953 	.n_mcgrps	= ARRAY_SIZE(mptcp_pm_mcgrps),
1954 };
1955 
1956 static int __net_init pm_nl_init_net(struct net *net)
1957 {
1958 	struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1959 
1960 	INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
1961 	pernet->next_id = 1;
1962 	pernet->stale_loss_cnt = 4;
1963 	spin_lock_init(&pernet->lock);
1964 
1965 	/* No need to initialize other pernet fields, the struct is zeroed at
1966 	 * allocation time.
1967 	 */
1968 
1969 	return 0;
1970 }
1971 
1972 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
1973 {
1974 	struct net *net;
1975 
1976 	list_for_each_entry(net, net_list, exit_list) {
1977 		struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1978 
1979 		/* net is removed from namespace list, can't race with
1980 		 * other modifiers
1981 		 */
1982 		__flush_addrs(&pernet->local_addr_list);
1983 	}
1984 }
1985 
1986 static struct pernet_operations mptcp_pm_pernet_ops = {
1987 	.init = pm_nl_init_net,
1988 	.exit_batch = pm_nl_exit_net,
1989 	.id = &pm_nl_pernet_id,
1990 	.size = sizeof(struct pm_nl_pernet),
1991 };
1992 
1993 void __init mptcp_pm_nl_init(void)
1994 {
1995 	if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
1996 		panic("Failed to register MPTCP PM pernet subsystem.\n");
1997 
1998 	if (genl_register_family(&mptcp_genl_family))
1999 		panic("Failed to register MPTCP PM netlink family\n");
2000 }
2001