xref: /openbmc/linux/net/mptcp/pm_netlink.c (revision 8d1af5c6af5c665cfa35b8e6dcb1a729989a3669)
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/inet_common.h>
13 #include <net/netns/generic.h>
14 #include <net/mptcp.h>
15 #include <net/genetlink.h>
16 #include <uapi/linux/mptcp.h>
17 
18 #include "protocol.h"
19 #include "mib.h"
20 
21 /* forward declaration */
22 static struct genl_family mptcp_genl_family;
23 
24 static int pm_nl_pernet_id;
25 
26 struct mptcp_pm_add_entry {
27 	struct list_head	list;
28 	struct mptcp_addr_info	addr;
29 	u8			retrans_times;
30 	struct timer_list	add_timer;
31 	struct mptcp_sock	*sock;
32 };
33 
34 struct pm_nl_pernet {
35 	/* protects pernet updates */
36 	spinlock_t		lock;
37 	struct list_head	local_addr_list;
38 	unsigned int		addrs;
39 	unsigned int		stale_loss_cnt;
40 	unsigned int		add_addr_signal_max;
41 	unsigned int		add_addr_accept_max;
42 	unsigned int		local_addr_max;
43 	unsigned int		subflows_max;
44 	unsigned int		next_id;
45 	DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
46 };
47 
48 #define MPTCP_PM_ADDR_MAX	8
49 #define ADD_ADDR_RETRANS_MAX	3
50 
51 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
52 {
53 	return net_generic(net, pm_nl_pernet_id);
54 }
55 
56 static struct pm_nl_pernet *
57 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
58 {
59 	return pm_nl_get_pernet(sock_net((struct sock *)msk));
60 }
61 
62 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
63 			   const struct mptcp_addr_info *b, bool use_port)
64 {
65 	bool addr_equals = false;
66 
67 	if (a->family == b->family) {
68 		if (a->family == AF_INET)
69 			addr_equals = a->addr.s_addr == b->addr.s_addr;
70 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
71 		else
72 			addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
73 	} else if (a->family == AF_INET) {
74 		if (ipv6_addr_v4mapped(&b->addr6))
75 			addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
76 	} else if (b->family == AF_INET) {
77 		if (ipv6_addr_v4mapped(&a->addr6))
78 			addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
79 #endif
80 	}
81 
82 	if (!addr_equals)
83 		return false;
84 	if (!use_port)
85 		return true;
86 
87 	return a->port == b->port;
88 }
89 
90 void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr)
91 {
92 	addr->family = skc->skc_family;
93 	addr->port = htons(skc->skc_num);
94 	if (addr->family == AF_INET)
95 		addr->addr.s_addr = skc->skc_rcv_saddr;
96 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
97 	else if (addr->family == AF_INET6)
98 		addr->addr6 = skc->skc_v6_rcv_saddr;
99 #endif
100 }
101 
102 static void remote_address(const struct sock_common *skc,
103 			   struct mptcp_addr_info *addr)
104 {
105 	addr->family = skc->skc_family;
106 	addr->port = skc->skc_dport;
107 	if (addr->family == AF_INET)
108 		addr->addr.s_addr = skc->skc_daddr;
109 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
110 	else if (addr->family == AF_INET6)
111 		addr->addr6 = skc->skc_v6_daddr;
112 #endif
113 }
114 
115 static bool lookup_subflow_by_saddr(const struct list_head *list,
116 				    const struct mptcp_addr_info *saddr)
117 {
118 	struct mptcp_subflow_context *subflow;
119 	struct mptcp_addr_info cur;
120 	struct sock_common *skc;
121 
122 	list_for_each_entry(subflow, list, node) {
123 		skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
124 
125 		mptcp_local_address(skc, &cur);
126 		if (mptcp_addresses_equal(&cur, saddr, saddr->port))
127 			return true;
128 	}
129 
130 	return false;
131 }
132 
133 static bool lookup_subflow_by_daddr(const struct list_head *list,
134 				    const struct mptcp_addr_info *daddr)
135 {
136 	struct mptcp_subflow_context *subflow;
137 	struct mptcp_addr_info cur;
138 
139 	list_for_each_entry(subflow, list, node) {
140 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
141 
142 		if (!((1 << inet_sk_state_load(ssk)) &
143 		      (TCPF_ESTABLISHED | TCPF_SYN_SENT | TCPF_SYN_RECV)))
144 			continue;
145 
146 		remote_address((struct sock_common *)ssk, &cur);
147 		if (mptcp_addresses_equal(&cur, daddr, daddr->port))
148 			return true;
149 	}
150 
151 	return false;
152 }
153 
154 static bool
155 select_local_address(const struct pm_nl_pernet *pernet,
156 		     const struct mptcp_sock *msk,
157 		     struct mptcp_pm_addr_entry *new_entry)
158 {
159 	struct mptcp_pm_addr_entry *entry;
160 	bool found = false;
161 
162 	msk_owned_by_me(msk);
163 
164 	rcu_read_lock();
165 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
166 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
167 			continue;
168 
169 		if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
170 			continue;
171 
172 		*new_entry = *entry;
173 		found = true;
174 		break;
175 	}
176 	rcu_read_unlock();
177 
178 	return found;
179 }
180 
181 static bool
182 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk,
183 		      struct mptcp_pm_addr_entry *new_entry)
184 {
185 	struct mptcp_pm_addr_entry *entry;
186 	bool found = false;
187 
188 	rcu_read_lock();
189 	/* do not keep any additional per socket state, just signal
190 	 * the address list in order.
191 	 * Note: removal from the local address list during the msk life-cycle
192 	 * can lead to additional addresses not being announced.
193 	 */
194 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
195 		if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
196 			continue;
197 
198 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
199 			continue;
200 
201 		*new_entry = *entry;
202 		found = true;
203 		break;
204 	}
205 	rcu_read_unlock();
206 
207 	return found;
208 }
209 
210 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk)
211 {
212 	const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
213 
214 	return READ_ONCE(pernet->add_addr_signal_max);
215 }
216 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
217 
218 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk)
219 {
220 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
221 
222 	return READ_ONCE(pernet->add_addr_accept_max);
223 }
224 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
225 
226 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk)
227 {
228 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
229 
230 	return READ_ONCE(pernet->subflows_max);
231 }
232 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
233 
234 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk)
235 {
236 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
237 
238 	return READ_ONCE(pernet->local_addr_max);
239 }
240 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
241 
242 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
243 {
244 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
245 
246 	if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
247 	    (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
248 			       MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
249 		WRITE_ONCE(msk->pm.work_pending, false);
250 		return false;
251 	}
252 	return true;
253 }
254 
255 struct mptcp_pm_add_entry *
256 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
257 				const struct mptcp_addr_info *addr)
258 {
259 	struct mptcp_pm_add_entry *entry;
260 
261 	lockdep_assert_held(&msk->pm.lock);
262 
263 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
264 		if (mptcp_addresses_equal(&entry->addr, addr, true))
265 			return entry;
266 	}
267 
268 	return NULL;
269 }
270 
271 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
272 {
273 	struct mptcp_pm_add_entry *entry;
274 	struct mptcp_addr_info saddr;
275 	bool ret = false;
276 
277 	mptcp_local_address((struct sock_common *)sk, &saddr);
278 
279 	spin_lock_bh(&msk->pm.lock);
280 	list_for_each_entry(entry, &msk->pm.anno_list, list) {
281 		if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
282 			ret = true;
283 			goto out;
284 		}
285 	}
286 
287 out:
288 	spin_unlock_bh(&msk->pm.lock);
289 	return ret;
290 }
291 
292 static void mptcp_pm_add_timer(struct timer_list *timer)
293 {
294 	struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
295 	struct mptcp_sock *msk = entry->sock;
296 	struct sock *sk = (struct sock *)msk;
297 
298 	pr_debug("msk=%p", msk);
299 
300 	if (!msk)
301 		return;
302 
303 	if (inet_sk_state_load(sk) == TCP_CLOSE)
304 		return;
305 
306 	if (!entry->addr.id)
307 		return;
308 
309 	if (mptcp_pm_should_add_signal_addr(msk)) {
310 		sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
311 		goto out;
312 	}
313 
314 	spin_lock_bh(&msk->pm.lock);
315 
316 	if (!mptcp_pm_should_add_signal_addr(msk)) {
317 		pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
318 		mptcp_pm_announce_addr(msk, &entry->addr, false);
319 		mptcp_pm_add_addr_send_ack(msk);
320 		entry->retrans_times++;
321 	}
322 
323 	if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
324 		sk_reset_timer(sk, timer,
325 			       jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
326 
327 	spin_unlock_bh(&msk->pm.lock);
328 
329 	if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
330 		mptcp_pm_subflow_established(msk);
331 
332 out:
333 	__sock_put(sk);
334 }
335 
336 struct mptcp_pm_add_entry *
337 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
338 		       const struct mptcp_addr_info *addr, bool check_id)
339 {
340 	struct mptcp_pm_add_entry *entry;
341 	struct sock *sk = (struct sock *)msk;
342 
343 	spin_lock_bh(&msk->pm.lock);
344 	entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
345 	if (entry && (!check_id || entry->addr.id == addr->id))
346 		entry->retrans_times = ADD_ADDR_RETRANS_MAX;
347 	spin_unlock_bh(&msk->pm.lock);
348 
349 	if (entry && (!check_id || entry->addr.id == addr->id))
350 		sk_stop_timer_sync(sk, &entry->add_timer);
351 
352 	return entry;
353 }
354 
355 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
356 			      const struct mptcp_addr_info *addr)
357 {
358 	struct mptcp_pm_add_entry *add_entry = NULL;
359 	struct sock *sk = (struct sock *)msk;
360 	struct net *net = sock_net(sk);
361 
362 	lockdep_assert_held(&msk->pm.lock);
363 
364 	add_entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
365 
366 	if (add_entry) {
367 		if (WARN_ON_ONCE(mptcp_pm_is_kernel(msk)))
368 			return false;
369 
370 		sk_reset_timer(sk, &add_entry->add_timer,
371 			       jiffies + mptcp_get_add_addr_timeout(net));
372 		return true;
373 	}
374 
375 	add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
376 	if (!add_entry)
377 		return false;
378 
379 	list_add(&add_entry->list, &msk->pm.anno_list);
380 
381 	add_entry->addr = *addr;
382 	add_entry->sock = msk;
383 	add_entry->retrans_times = 0;
384 
385 	timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
386 	sk_reset_timer(sk, &add_entry->add_timer,
387 		       jiffies + mptcp_get_add_addr_timeout(net));
388 
389 	return true;
390 }
391 
392 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
393 {
394 	struct mptcp_pm_add_entry *entry, *tmp;
395 	struct sock *sk = (struct sock *)msk;
396 	LIST_HEAD(free_list);
397 
398 	pr_debug("msk=%p", msk);
399 
400 	spin_lock_bh(&msk->pm.lock);
401 	list_splice_init(&msk->pm.anno_list, &free_list);
402 	spin_unlock_bh(&msk->pm.lock);
403 
404 	list_for_each_entry_safe(entry, tmp, &free_list, list) {
405 		sk_stop_timer_sync(sk, &entry->add_timer);
406 		kfree(entry);
407 	}
408 }
409 
410 /* Fill all the remote addresses into the array addrs[],
411  * and return the array size.
412  */
413 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk,
414 					      struct mptcp_addr_info *local,
415 					      bool fullmesh,
416 					      struct mptcp_addr_info *addrs)
417 {
418 	bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
419 	struct sock *sk = (struct sock *)msk, *ssk;
420 	struct mptcp_subflow_context *subflow;
421 	struct mptcp_addr_info remote = { 0 };
422 	unsigned int subflows_max;
423 	int i = 0;
424 
425 	subflows_max = mptcp_pm_get_subflows_max(msk);
426 	remote_address((struct sock_common *)sk, &remote);
427 
428 	/* Non-fullmesh endpoint, fill in the single entry
429 	 * corresponding to the primary MPC subflow remote address
430 	 */
431 	if (!fullmesh) {
432 		if (deny_id0)
433 			return 0;
434 
435 		if (!mptcp_pm_addr_families_match(sk, local, &remote))
436 			return 0;
437 
438 		msk->pm.subflows++;
439 		addrs[i++] = remote;
440 	} else {
441 		DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
442 
443 		/* Forbid creation of new subflows matching existing
444 		 * ones, possibly already created by incoming ADD_ADDR
445 		 */
446 		bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
447 		mptcp_for_each_subflow(msk, subflow)
448 			if (READ_ONCE(subflow->local_id) == local->id)
449 				__set_bit(subflow->remote_id, unavail_id);
450 
451 		mptcp_for_each_subflow(msk, subflow) {
452 			ssk = mptcp_subflow_tcp_sock(subflow);
453 			remote_address((struct sock_common *)ssk, &addrs[i]);
454 			addrs[i].id = READ_ONCE(subflow->remote_id);
455 			if (deny_id0 && !addrs[i].id)
456 				continue;
457 
458 			if (test_bit(addrs[i].id, unavail_id))
459 				continue;
460 
461 			if (!mptcp_pm_addr_families_match(sk, local, &addrs[i]))
462 				continue;
463 
464 			if (msk->pm.subflows < subflows_max) {
465 				/* forbid creating multiple address towards
466 				 * this id
467 				 */
468 				__set_bit(addrs[i].id, unavail_id);
469 				msk->pm.subflows++;
470 				i++;
471 			}
472 		}
473 	}
474 
475 	return i;
476 }
477 
478 static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
479 				bool prio, bool backup)
480 {
481 	struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
482 	bool slow;
483 
484 	pr_debug("send ack for %s",
485 		 prio ? "mp_prio" : (mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr"));
486 
487 	slow = lock_sock_fast(ssk);
488 	if (prio) {
489 		subflow->send_mp_prio = 1;
490 		subflow->request_bkup = backup;
491 	}
492 
493 	__mptcp_subflow_send_ack(ssk);
494 	unlock_sock_fast(ssk, slow);
495 }
496 
497 static void mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
498 			      bool prio, bool backup)
499 {
500 	spin_unlock_bh(&msk->pm.lock);
501 	__mptcp_pm_send_ack(msk, subflow, prio, backup);
502 	spin_lock_bh(&msk->pm.lock);
503 }
504 
505 static struct mptcp_pm_addr_entry *
506 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
507 {
508 	struct mptcp_pm_addr_entry *entry;
509 
510 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
511 		if (entry->addr.id == id)
512 			return entry;
513 	}
514 	return NULL;
515 }
516 
517 static struct mptcp_pm_addr_entry *
518 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
519 	      bool lookup_by_id)
520 {
521 	struct mptcp_pm_addr_entry *entry;
522 
523 	list_for_each_entry(entry, &pernet->local_addr_list, list) {
524 		if ((!lookup_by_id &&
525 		     mptcp_addresses_equal(&entry->addr, info, entry->addr.port)) ||
526 		    (lookup_by_id && entry->addr.id == info->id))
527 			return entry;
528 	}
529 	return NULL;
530 }
531 
532 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
533 {
534 	struct sock *sk = (struct sock *)msk;
535 	struct mptcp_pm_addr_entry local;
536 	unsigned int add_addr_signal_max;
537 	bool signal_and_subflow = false;
538 	unsigned int local_addr_max;
539 	struct pm_nl_pernet *pernet;
540 	unsigned int subflows_max;
541 
542 	pernet = pm_nl_get_pernet(sock_net(sk));
543 
544 	add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
545 	local_addr_max = mptcp_pm_get_local_addr_max(msk);
546 	subflows_max = mptcp_pm_get_subflows_max(msk);
547 
548 	/* do lazy endpoint usage accounting for the MPC subflows */
549 	if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
550 		struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
551 		struct mptcp_pm_addr_entry *entry;
552 		struct mptcp_addr_info mpc_addr;
553 		bool backup = false;
554 
555 		mptcp_local_address((struct sock_common *)msk->first, &mpc_addr);
556 		rcu_read_lock();
557 		entry = __lookup_addr(pernet, &mpc_addr, false);
558 		if (entry) {
559 			__clear_bit(entry->addr.id, msk->pm.id_avail_bitmap);
560 			msk->mpc_endpoint_id = entry->addr.id;
561 			backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
562 		}
563 		rcu_read_unlock();
564 
565 		if (backup)
566 			mptcp_pm_send_ack(msk, subflow, true, backup);
567 
568 		msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
569 	}
570 
571 	pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
572 		 msk->pm.local_addr_used, local_addr_max,
573 		 msk->pm.add_addr_signaled, add_addr_signal_max,
574 		 msk->pm.subflows, subflows_max);
575 
576 	/* check first for announce */
577 	if (msk->pm.add_addr_signaled < add_addr_signal_max) {
578 		/* due to racing events on both ends we can reach here while
579 		 * previous add address is still running: if we invoke now
580 		 * mptcp_pm_announce_addr(), that will fail and the
581 		 * corresponding id will be marked as used.
582 		 * Instead let the PM machinery reschedule us when the
583 		 * current address announce will be completed.
584 		 */
585 		if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
586 			return;
587 
588 		if (!select_signal_address(pernet, msk, &local))
589 			goto subflow;
590 
591 		/* If the alloc fails, we are on memory pressure, not worth
592 		 * continuing, and trying to create subflows.
593 		 */
594 		if (!mptcp_pm_alloc_anno_list(msk, &local.addr))
595 			return;
596 
597 		__clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
598 		msk->pm.add_addr_signaled++;
599 
600 		/* Special case for ID0: set the correct ID */
601 		if (local.addr.id == msk->mpc_endpoint_id)
602 			local.addr.id = 0;
603 
604 		mptcp_pm_announce_addr(msk, &local.addr, false);
605 		mptcp_pm_nl_addr_send_ack(msk);
606 
607 		if (local.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
608 			signal_and_subflow = true;
609 	}
610 
611 subflow:
612 	/* check if should create a new subflow */
613 	while (msk->pm.local_addr_used < local_addr_max &&
614 	       msk->pm.subflows < subflows_max) {
615 		struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
616 		bool fullmesh;
617 		int i, nr;
618 
619 		if (signal_and_subflow)
620 			signal_and_subflow = false;
621 		else if (!select_local_address(pernet, msk, &local))
622 			break;
623 
624 		fullmesh = !!(local.flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
625 
626 		__clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
627 
628 		/* Special case for ID0: set the correct ID */
629 		if (local.addr.id == msk->mpc_endpoint_id)
630 			local.addr.id = 0;
631 		else /* local_addr_used is not decr for ID 0 */
632 			msk->pm.local_addr_used++;
633 
634 		nr = fill_remote_addresses_vec(msk, &local.addr, fullmesh, addrs);
635 		if (nr == 0)
636 			continue;
637 
638 		spin_unlock_bh(&msk->pm.lock);
639 		for (i = 0; i < nr; i++)
640 			__mptcp_subflow_connect(sk, &local.addr, &addrs[i]);
641 		spin_lock_bh(&msk->pm.lock);
642 	}
643 	mptcp_pm_nl_check_work_pending(msk);
644 }
645 
646 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
647 {
648 	mptcp_pm_create_subflow_or_signal_addr(msk);
649 }
650 
651 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
652 {
653 	mptcp_pm_create_subflow_or_signal_addr(msk);
654 }
655 
656 /* Fill all the local addresses into the array addrs[],
657  * and return the array size.
658  */
659 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
660 					     struct mptcp_addr_info *remote,
661 					     struct mptcp_addr_info *addrs)
662 {
663 	struct sock *sk = (struct sock *)msk;
664 	struct mptcp_pm_addr_entry *entry;
665 	struct mptcp_addr_info mpc_addr;
666 	struct pm_nl_pernet *pernet;
667 	unsigned int subflows_max;
668 	int i = 0;
669 
670 	pernet = pm_nl_get_pernet_from_msk(msk);
671 	subflows_max = mptcp_pm_get_subflows_max(msk);
672 
673 	mptcp_local_address((struct sock_common *)msk, &mpc_addr);
674 
675 	rcu_read_lock();
676 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
677 		if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
678 			continue;
679 
680 		if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote))
681 			continue;
682 
683 		if (msk->pm.subflows < subflows_max) {
684 			msk->pm.subflows++;
685 			addrs[i] = entry->addr;
686 
687 			/* Special case for ID0: set the correct ID */
688 			if (mptcp_addresses_equal(&entry->addr, &mpc_addr, entry->addr.port))
689 				addrs[i].id = 0;
690 
691 			i++;
692 		}
693 	}
694 	rcu_read_unlock();
695 
696 	/* If the array is empty, fill in the single
697 	 * 'IPADDRANY' local address
698 	 */
699 	if (!i) {
700 		struct mptcp_addr_info local;
701 
702 		memset(&local, 0, sizeof(local));
703 		local.family =
704 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
705 			       remote->family == AF_INET6 &&
706 			       ipv6_addr_v4mapped(&remote->addr6) ? AF_INET :
707 #endif
708 			       remote->family;
709 
710 		if (!mptcp_pm_addr_families_match(sk, &local, remote))
711 			return 0;
712 
713 		msk->pm.subflows++;
714 		addrs[i++] = local;
715 	}
716 
717 	return i;
718 }
719 
720 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
721 {
722 	struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
723 	struct sock *sk = (struct sock *)msk;
724 	unsigned int add_addr_accept_max;
725 	struct mptcp_addr_info remote;
726 	unsigned int subflows_max;
727 	bool sf_created = false;
728 	int i, nr;
729 
730 	add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
731 	subflows_max = mptcp_pm_get_subflows_max(msk);
732 
733 	pr_debug("accepted %d:%d remote family %d",
734 		 msk->pm.add_addr_accepted, add_addr_accept_max,
735 		 msk->pm.remote.family);
736 
737 	remote = msk->pm.remote;
738 	mptcp_pm_announce_addr(msk, &remote, true);
739 	mptcp_pm_nl_addr_send_ack(msk);
740 
741 	if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
742 		return;
743 
744 	/* pick id 0 port, if none is provided the remote address */
745 	if (!remote.port)
746 		remote.port = sk->sk_dport;
747 
748 	/* connect to the specified remote address, using whatever
749 	 * local address the routing configuration will pick.
750 	 */
751 	nr = fill_local_addresses_vec(msk, &remote, addrs);
752 	if (nr == 0)
753 		return;
754 
755 	spin_unlock_bh(&msk->pm.lock);
756 	for (i = 0; i < nr; i++)
757 		if (__mptcp_subflow_connect(sk, &addrs[i], &remote) == 0)
758 			sf_created = true;
759 	spin_lock_bh(&msk->pm.lock);
760 
761 	if (sf_created) {
762 		/* add_addr_accepted is not decr for ID 0 */
763 		if (remote.id)
764 			msk->pm.add_addr_accepted++;
765 		if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
766 		    msk->pm.subflows >= subflows_max)
767 			WRITE_ONCE(msk->pm.accept_addr, false);
768 	}
769 }
770 
771 bool mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock *msk,
772 				     const struct mptcp_addr_info *remote)
773 {
774 	struct mptcp_addr_info mpc_remote;
775 
776 	remote_address((struct sock_common *)msk, &mpc_remote);
777 	return mptcp_addresses_equal(&mpc_remote, remote, remote->port);
778 }
779 
780 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
781 {
782 	struct mptcp_subflow_context *subflow;
783 
784 	msk_owned_by_me(msk);
785 	lockdep_assert_held(&msk->pm.lock);
786 
787 	if (!mptcp_pm_should_add_signal(msk) &&
788 	    !mptcp_pm_should_rm_signal(msk))
789 		return;
790 
791 	mptcp_for_each_subflow(msk, subflow) {
792 		if (__mptcp_subflow_active(subflow)) {
793 			mptcp_pm_send_ack(msk, subflow, false, false);
794 			break;
795 		}
796 	}
797 }
798 
799 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
800 				 struct mptcp_addr_info *addr,
801 				 struct mptcp_addr_info *rem,
802 				 u8 bkup)
803 {
804 	struct mptcp_subflow_context *subflow;
805 
806 	pr_debug("bkup=%d", bkup);
807 
808 	mptcp_for_each_subflow(msk, subflow) {
809 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
810 		struct mptcp_addr_info local, remote;
811 
812 		mptcp_local_address((struct sock_common *)ssk, &local);
813 		if (!mptcp_addresses_equal(&local, addr, addr->port))
814 			continue;
815 
816 		if (rem && rem->family != AF_UNSPEC) {
817 			remote_address((struct sock_common *)ssk, &remote);
818 			if (!mptcp_addresses_equal(&remote, rem, rem->port))
819 				continue;
820 		}
821 
822 		__mptcp_pm_send_ack(msk, subflow, true, bkup);
823 		return 0;
824 	}
825 
826 	return -EINVAL;
827 }
828 
829 static bool mptcp_local_id_match(const struct mptcp_sock *msk, u8 local_id, u8 id)
830 {
831 	return local_id == id || (!local_id && msk->mpc_endpoint_id == id);
832 }
833 
834 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
835 					   const struct mptcp_rm_list *rm_list,
836 					   enum linux_mptcp_mib_field rm_type)
837 {
838 	struct mptcp_subflow_context *subflow, *tmp;
839 	struct sock *sk = (struct sock *)msk;
840 	u8 i;
841 
842 	pr_debug("%s rm_list_nr %d",
843 		 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
844 
845 	msk_owned_by_me(msk);
846 
847 	if (sk->sk_state == TCP_LISTEN)
848 		return;
849 
850 	if (!rm_list->nr)
851 		return;
852 
853 	if (list_empty(&msk->conn_list))
854 		return;
855 
856 	for (i = 0; i < rm_list->nr; i++) {
857 		u8 rm_id = rm_list->ids[i];
858 		bool removed = false;
859 
860 		mptcp_for_each_subflow_safe(msk, subflow, tmp) {
861 			struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
862 			u8 remote_id = READ_ONCE(subflow->remote_id);
863 			int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
864 			u8 id = subflow_get_local_id(subflow);
865 
866 			if (inet_sk_state_load(ssk) == TCP_CLOSE)
867 				continue;
868 			if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
869 				continue;
870 			if (rm_type == MPTCP_MIB_RMSUBFLOW && !mptcp_local_id_match(msk, id, rm_id))
871 				continue;
872 
873 			pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u",
874 				 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
875 				 i, rm_id, id, remote_id, msk->mpc_endpoint_id);
876 			spin_unlock_bh(&msk->pm.lock);
877 			mptcp_subflow_shutdown(sk, ssk, how);
878 
879 			/* the following takes care of updating the subflows counter */
880 			mptcp_close_ssk(sk, ssk, subflow);
881 			spin_lock_bh(&msk->pm.lock);
882 
883 			removed |= subflow->request_join;
884 			if (rm_type == MPTCP_MIB_RMSUBFLOW)
885 				__MPTCP_INC_STATS(sock_net(sk), rm_type);
886 		}
887 
888 		if (rm_type == MPTCP_MIB_RMADDR)
889 			__MPTCP_INC_STATS(sock_net(sk), rm_type);
890 
891 		if (!removed)
892 			continue;
893 
894 		if (!mptcp_pm_is_kernel(msk))
895 			continue;
896 
897 		if (rm_type == MPTCP_MIB_RMADDR && rm_id &&
898 		    !WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)) {
899 			/* Note: if the subflow has been closed before, this
900 			 * add_addr_accepted counter will not be decremented.
901 			 */
902 			if (--msk->pm.add_addr_accepted < mptcp_pm_get_add_addr_accept_max(msk))
903 				WRITE_ONCE(msk->pm.accept_addr, true);
904 		}
905 	}
906 }
907 
908 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
909 {
910 	mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
911 }
912 
913 static void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
914 					    const struct mptcp_rm_list *rm_list)
915 {
916 	mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
917 }
918 
919 void mptcp_pm_nl_work(struct mptcp_sock *msk)
920 {
921 	struct mptcp_pm_data *pm = &msk->pm;
922 
923 	msk_owned_by_me(msk);
924 
925 	if (!(pm->status & MPTCP_PM_WORK_MASK))
926 		return;
927 
928 	spin_lock_bh(&msk->pm.lock);
929 
930 	pr_debug("msk=%p status=%x", msk, pm->status);
931 	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
932 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
933 		mptcp_pm_nl_add_addr_received(msk);
934 	}
935 	if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
936 		pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
937 		mptcp_pm_nl_addr_send_ack(msk);
938 	}
939 	if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
940 		pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
941 		mptcp_pm_nl_rm_addr_received(msk);
942 	}
943 	if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
944 		pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
945 		mptcp_pm_nl_fully_established(msk);
946 	}
947 	if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
948 		pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
949 		mptcp_pm_nl_subflow_established(msk);
950 	}
951 
952 	spin_unlock_bh(&msk->pm.lock);
953 }
954 
955 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
956 {
957 	return (entry->flags &
958 		(MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
959 		MPTCP_PM_ADDR_FLAG_SIGNAL;
960 }
961 
962 /* caller must ensure the RCU grace period is already elapsed */
963 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
964 {
965 	if (entry->lsk)
966 		sock_release(entry->lsk);
967 	kfree(entry);
968 }
969 
970 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
971 					     struct mptcp_pm_addr_entry *entry,
972 					     bool needs_id)
973 {
974 	struct mptcp_pm_addr_entry *cur, *del_entry = NULL;
975 	unsigned int addr_max;
976 	int ret = -EINVAL;
977 
978 	spin_lock_bh(&pernet->lock);
979 	/* to keep the code simple, don't do IDR-like allocation for address ID,
980 	 * just bail when we exceed limits
981 	 */
982 	if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
983 		pernet->next_id = 1;
984 	if (pernet->addrs >= MPTCP_PM_ADDR_MAX) {
985 		ret = -ERANGE;
986 		goto out;
987 	}
988 	if (test_bit(entry->addr.id, pernet->id_bitmap)) {
989 		ret = -EBUSY;
990 		goto out;
991 	}
992 
993 	/* do not insert duplicate address, differentiate on port only
994 	 * singled addresses
995 	 */
996 	if (!address_use_port(entry))
997 		entry->addr.port = 0;
998 	list_for_each_entry(cur, &pernet->local_addr_list, list) {
999 		if (mptcp_addresses_equal(&cur->addr, &entry->addr,
1000 					  cur->addr.port || entry->addr.port)) {
1001 			/* allow replacing the exiting endpoint only if such
1002 			 * endpoint is an implicit one and the user-space
1003 			 * did not provide an endpoint id
1004 			 */
1005 			if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) {
1006 				ret = -EEXIST;
1007 				goto out;
1008 			}
1009 			if (entry->addr.id)
1010 				goto out;
1011 
1012 			pernet->addrs--;
1013 			entry->addr.id = cur->addr.id;
1014 			list_del_rcu(&cur->list);
1015 			del_entry = cur;
1016 			break;
1017 		}
1018 	}
1019 
1020 	if (!entry->addr.id && needs_id) {
1021 find_next:
1022 		entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
1023 						    MPTCP_PM_MAX_ADDR_ID + 1,
1024 						    pernet->next_id);
1025 		if (!entry->addr.id && pernet->next_id != 1) {
1026 			pernet->next_id = 1;
1027 			goto find_next;
1028 		}
1029 	}
1030 
1031 	if (!entry->addr.id && needs_id)
1032 		goto out;
1033 
1034 	__set_bit(entry->addr.id, pernet->id_bitmap);
1035 	if (entry->addr.id > pernet->next_id)
1036 		pernet->next_id = entry->addr.id;
1037 
1038 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1039 		addr_max = pernet->add_addr_signal_max;
1040 		WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
1041 	}
1042 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1043 		addr_max = pernet->local_addr_max;
1044 		WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
1045 	}
1046 
1047 	pernet->addrs++;
1048 	if (!entry->addr.port)
1049 		list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
1050 	else
1051 		list_add_rcu(&entry->list, &pernet->local_addr_list);
1052 	ret = entry->addr.id;
1053 
1054 out:
1055 	spin_unlock_bh(&pernet->lock);
1056 
1057 	/* just replaced an existing entry, free it */
1058 	if (del_entry) {
1059 		synchronize_rcu();
1060 		__mptcp_pm_release_addr_entry(del_entry);
1061 	}
1062 	return ret;
1063 }
1064 
1065 static struct lock_class_key mptcp_slock_keys[2];
1066 static struct lock_class_key mptcp_keys[2];
1067 
1068 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
1069 					    struct mptcp_pm_addr_entry *entry)
1070 {
1071 	bool is_ipv6 = sk->sk_family == AF_INET6;
1072 	int addrlen = sizeof(struct sockaddr_in);
1073 	struct sockaddr_storage addr;
1074 	struct sock *newsk, *ssk;
1075 	int backlog = 1024;
1076 	int err;
1077 
1078 	err = sock_create_kern(sock_net(sk), entry->addr.family,
1079 			       SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
1080 	if (err)
1081 		return err;
1082 
1083 	newsk = entry->lsk->sk;
1084 	if (!newsk)
1085 		return -EINVAL;
1086 
1087 	/* The subflow socket lock is acquired in a nested to the msk one
1088 	 * in several places, even by the TCP stack, and this msk is a kernel
1089 	 * socket: lockdep complains. Instead of propagating the _nested
1090 	 * modifiers in several places, re-init the lock class for the msk
1091 	 * socket to an mptcp specific one.
1092 	 */
1093 	sock_lock_init_class_and_name(newsk,
1094 				      is_ipv6 ? "mlock-AF_INET6" : "mlock-AF_INET",
1095 				      &mptcp_slock_keys[is_ipv6],
1096 				      is_ipv6 ? "msk_lock-AF_INET6" : "msk_lock-AF_INET",
1097 				      &mptcp_keys[is_ipv6]);
1098 
1099 	lock_sock(newsk);
1100 	ssk = __mptcp_nmpc_sk(mptcp_sk(newsk));
1101 	release_sock(newsk);
1102 	if (IS_ERR(ssk))
1103 		return PTR_ERR(ssk);
1104 
1105 	mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
1106 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1107 	if (entry->addr.family == AF_INET6)
1108 		addrlen = sizeof(struct sockaddr_in6);
1109 #endif
1110 	if (ssk->sk_family == AF_INET)
1111 		err = inet_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1112 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1113 	else if (ssk->sk_family == AF_INET6)
1114 		err = inet6_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1115 #endif
1116 	if (err)
1117 		return err;
1118 
1119 	/* We don't use mptcp_set_state() here because it needs to be called
1120 	 * under the msk socket lock. For the moment, that will not bring
1121 	 * anything more than only calling inet_sk_state_store(), because the
1122 	 * old status is known (TCP_CLOSE).
1123 	 */
1124 	inet_sk_state_store(newsk, TCP_LISTEN);
1125 	lock_sock(ssk);
1126 	err = __inet_listen_sk(ssk, backlog);
1127 	if (!err)
1128 		mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED);
1129 	release_sock(ssk);
1130 	return err;
1131 }
1132 
1133 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1134 {
1135 	struct mptcp_pm_addr_entry *entry;
1136 	struct pm_nl_pernet *pernet;
1137 	int ret = -1;
1138 
1139 	pernet = pm_nl_get_pernet_from_msk(msk);
1140 
1141 	rcu_read_lock();
1142 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1143 		if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
1144 			ret = entry->addr.id;
1145 			break;
1146 		}
1147 	}
1148 	rcu_read_unlock();
1149 	if (ret >= 0)
1150 		return ret;
1151 
1152 	/* address not found, add to local list */
1153 	entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1154 	if (!entry)
1155 		return -ENOMEM;
1156 
1157 	entry->addr = *skc;
1158 	entry->addr.id = 0;
1159 	entry->addr.port = 0;
1160 	entry->ifindex = 0;
1161 	entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
1162 	entry->lsk = NULL;
1163 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
1164 	if (ret < 0)
1165 		kfree(entry);
1166 
1167 	return ret;
1168 }
1169 
1170 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1171 {
1172 	struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
1173 	struct mptcp_pm_addr_entry *entry;
1174 	bool backup = false;
1175 
1176 	rcu_read_lock();
1177 	list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1178 		if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
1179 			backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
1180 			break;
1181 		}
1182 	}
1183 	rcu_read_unlock();
1184 
1185 	return backup;
1186 }
1187 
1188 #define MPTCP_PM_CMD_GRP_OFFSET       0
1189 #define MPTCP_PM_EV_GRP_OFFSET        1
1190 
1191 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1192 	[MPTCP_PM_CMD_GRP_OFFSET]	= { .name = MPTCP_PM_CMD_GRP_NAME, },
1193 	[MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
1194 					    .flags = GENL_UNS_ADMIN_PERM,
1195 					  },
1196 };
1197 
1198 static const struct nla_policy
1199 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
1200 	[MPTCP_PM_ADDR_ATTR_FAMILY]	= { .type	= NLA_U16,	},
1201 	[MPTCP_PM_ADDR_ATTR_ID]		= { .type	= NLA_U8,	},
1202 	[MPTCP_PM_ADDR_ATTR_ADDR4]	= { .type	= NLA_U32,	},
1203 	[MPTCP_PM_ADDR_ATTR_ADDR6]	=
1204 		NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
1205 	[MPTCP_PM_ADDR_ATTR_PORT]	= { .type	= NLA_U16	},
1206 	[MPTCP_PM_ADDR_ATTR_FLAGS]	= { .type	= NLA_U32	},
1207 	[MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type	= NLA_S32	},
1208 };
1209 
1210 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
1211 	[MPTCP_PM_ATTR_ADDR]		=
1212 					NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1213 	[MPTCP_PM_ATTR_RCV_ADD_ADDRS]	= { .type	= NLA_U32,	},
1214 	[MPTCP_PM_ATTR_SUBFLOWS]	= { .type	= NLA_U32,	},
1215 	[MPTCP_PM_ATTR_TOKEN]		= { .type	= NLA_U32,	},
1216 	[MPTCP_PM_ATTR_LOC_ID]		= { .type	= NLA_U8,	},
1217 	[MPTCP_PM_ATTR_ADDR_REMOTE]	=
1218 					NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1219 };
1220 
1221 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1222 {
1223 	struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1224 	struct sock *sk = (struct sock *)msk;
1225 	unsigned int active_max_loss_cnt;
1226 	struct net *net = sock_net(sk);
1227 	unsigned int stale_loss_cnt;
1228 	bool slow;
1229 
1230 	stale_loss_cnt = mptcp_stale_loss_cnt(net);
1231 	if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1232 		return;
1233 
1234 	/* look for another available subflow not in loss state */
1235 	active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1236 	mptcp_for_each_subflow(msk, iter) {
1237 		if (iter != subflow && mptcp_subflow_active(iter) &&
1238 		    iter->stale_count < active_max_loss_cnt) {
1239 			/* we have some alternatives, try to mark this subflow as idle ...*/
1240 			slow = lock_sock_fast(ssk);
1241 			if (!tcp_rtx_and_write_queues_empty(ssk)) {
1242 				subflow->stale = 1;
1243 				__mptcp_retransmit_pending_data(sk);
1244 				MPTCP_INC_STATS(net, MPTCP_MIB_SUBFLOWSTALE);
1245 			}
1246 			unlock_sock_fast(ssk, slow);
1247 
1248 			/* always try to push the pending data regardless of re-injections:
1249 			 * we can possibly use backup subflows now, and subflow selection
1250 			 * is cheap under the msk socket lock
1251 			 */
1252 			__mptcp_push_pending(sk, 0);
1253 			return;
1254 		}
1255 	}
1256 }
1257 
1258 static int mptcp_pm_family_to_addr(int family)
1259 {
1260 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1261 	if (family == AF_INET6)
1262 		return MPTCP_PM_ADDR_ATTR_ADDR6;
1263 #endif
1264 	return MPTCP_PM_ADDR_ATTR_ADDR4;
1265 }
1266 
1267 static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
1268 				       const struct nlattr *attr,
1269 				       struct genl_info *info,
1270 				       struct mptcp_addr_info *addr,
1271 				       bool require_family)
1272 {
1273 	int err, addr_addr;
1274 
1275 	if (!attr) {
1276 		GENL_SET_ERR_MSG(info, "missing address info");
1277 		return -EINVAL;
1278 	}
1279 
1280 	/* no validation needed - was already done via nested policy */
1281 	err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1282 					  mptcp_pm_addr_policy, info->extack);
1283 	if (err)
1284 		return err;
1285 
1286 	if (tb[MPTCP_PM_ADDR_ATTR_ID])
1287 		addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1288 
1289 	if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1290 		if (!require_family)
1291 			return 0;
1292 
1293 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
1294 				    "missing family");
1295 		return -EINVAL;
1296 	}
1297 
1298 	addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1299 	if (addr->family != AF_INET
1300 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1301 	    && addr->family != AF_INET6
1302 #endif
1303 	    ) {
1304 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
1305 				    "unknown address family");
1306 		return -EINVAL;
1307 	}
1308 	addr_addr = mptcp_pm_family_to_addr(addr->family);
1309 	if (!tb[addr_addr]) {
1310 		NL_SET_ERR_MSG_ATTR(info->extack, attr,
1311 				    "missing address data");
1312 		return -EINVAL;
1313 	}
1314 
1315 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1316 	if (addr->family == AF_INET6)
1317 		addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
1318 	else
1319 #endif
1320 		addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1321 
1322 	if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1323 		addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1324 
1325 	return 0;
1326 }
1327 
1328 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1329 			struct mptcp_addr_info *addr)
1330 {
1331 	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1332 
1333 	memset(addr, 0, sizeof(*addr));
1334 
1335 	return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
1336 }
1337 
1338 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1339 			 bool require_family,
1340 			 struct mptcp_pm_addr_entry *entry)
1341 {
1342 	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1343 	int err;
1344 
1345 	memset(entry, 0, sizeof(*entry));
1346 
1347 	err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
1348 	if (err)
1349 		return err;
1350 
1351 	if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1352 		u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1353 
1354 		entry->ifindex = val;
1355 	}
1356 
1357 	if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1358 		entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1359 
1360 	if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1361 		entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1362 
1363 	return 0;
1364 }
1365 
1366 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1367 {
1368 	return pm_nl_get_pernet(genl_info_net(info));
1369 }
1370 
1371 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net,
1372 					       struct mptcp_addr_info *addr)
1373 {
1374 	struct mptcp_sock *msk;
1375 	long s_slot = 0, s_num = 0;
1376 
1377 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1378 		struct sock *sk = (struct sock *)msk;
1379 		struct mptcp_addr_info mpc_addr;
1380 
1381 		if (!READ_ONCE(msk->fully_established) ||
1382 		    mptcp_pm_is_userspace(msk))
1383 			goto next;
1384 
1385 		/* if the endp linked to the init sf is re-added with a != ID */
1386 		mptcp_local_address((struct sock_common *)msk, &mpc_addr);
1387 
1388 		lock_sock(sk);
1389 		spin_lock_bh(&msk->pm.lock);
1390 		if (mptcp_addresses_equal(addr, &mpc_addr, addr->port))
1391 			msk->mpc_endpoint_id = addr->id;
1392 		mptcp_pm_create_subflow_or_signal_addr(msk);
1393 		spin_unlock_bh(&msk->pm.lock);
1394 		release_sock(sk);
1395 
1396 next:
1397 		sock_put(sk);
1398 		cond_resched();
1399 	}
1400 
1401 	return 0;
1402 }
1403 
1404 static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr,
1405 				      struct genl_info *info)
1406 {
1407 	struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1408 
1409 	if (!nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1410 					 mptcp_pm_addr_policy, info->extack) &&
1411 	    tb[MPTCP_PM_ADDR_ATTR_ID])
1412 		return true;
1413 	return false;
1414 }
1415 
1416 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1417 {
1418 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1419 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1420 	struct mptcp_pm_addr_entry addr, *entry;
1421 	int ret;
1422 
1423 	ret = mptcp_pm_parse_entry(attr, info, true, &addr);
1424 	if (ret < 0)
1425 		return ret;
1426 
1427 	if (addr.addr.port && !address_use_port(&addr)) {
1428 		GENL_SET_ERR_MSG(info, "flags must have signal and not subflow when using port");
1429 		return -EINVAL;
1430 	}
1431 
1432 	if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
1433 	    addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
1434 		GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
1435 		return -EINVAL;
1436 	}
1437 
1438 	if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
1439 		GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
1440 		return -EINVAL;
1441 	}
1442 
1443 	entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
1444 	if (!entry) {
1445 		GENL_SET_ERR_MSG(info, "can't allocate addr");
1446 		return -ENOMEM;
1447 	}
1448 
1449 	*entry = addr;
1450 	if (entry->addr.port) {
1451 		ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1452 		if (ret) {
1453 			GENL_SET_ERR_MSG_FMT(info, "create listen socket error: %d", ret);
1454 			goto out_free;
1455 		}
1456 	}
1457 	ret = mptcp_pm_nl_append_new_local_addr(pernet, entry,
1458 						!mptcp_pm_has_addr_attr_id(attr, info));
1459 	if (ret < 0) {
1460 		GENL_SET_ERR_MSG_FMT(info, "too many addresses or duplicate one: %d", ret);
1461 		goto out_free;
1462 	}
1463 
1464 	mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk), &entry->addr);
1465 	return 0;
1466 
1467 out_free:
1468 	__mptcp_pm_release_addr_entry(entry);
1469 	return ret;
1470 }
1471 
1472 int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
1473 					    u8 *flags, int *ifindex)
1474 {
1475 	struct mptcp_pm_addr_entry *entry;
1476 	struct sock *sk = (struct sock *)msk;
1477 	struct net *net = sock_net(sk);
1478 
1479 	/* No entries with ID 0 */
1480 	if (id == 0)
1481 		return 0;
1482 
1483 	rcu_read_lock();
1484 	entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
1485 	if (entry) {
1486 		*flags = entry->flags;
1487 		*ifindex = entry->ifindex;
1488 	}
1489 	rcu_read_unlock();
1490 
1491 	return 0;
1492 }
1493 
1494 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1495 				      const struct mptcp_addr_info *addr)
1496 {
1497 	struct mptcp_pm_add_entry *entry;
1498 
1499 	entry = mptcp_pm_del_add_timer(msk, addr, false);
1500 	if (entry) {
1501 		list_del(&entry->list);
1502 		kfree(entry);
1503 		return true;
1504 	}
1505 
1506 	return false;
1507 }
1508 
1509 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1510 				      const struct mptcp_addr_info *addr,
1511 				      bool force)
1512 {
1513 	struct mptcp_rm_list list = { .nr = 0 };
1514 	bool ret;
1515 
1516 	list.ids[list.nr++] = addr->id;
1517 
1518 	ret = remove_anno_list_by_saddr(msk, addr);
1519 	if (ret || force) {
1520 		spin_lock_bh(&msk->pm.lock);
1521 		if (ret) {
1522 			__set_bit(addr->id, msk->pm.id_avail_bitmap);
1523 			msk->pm.add_addr_signaled--;
1524 		}
1525 		mptcp_pm_remove_addr(msk, &list);
1526 		spin_unlock_bh(&msk->pm.lock);
1527 	}
1528 	return ret;
1529 }
1530 
1531 static void __mark_subflow_endp_available(struct mptcp_sock *msk, u8 id)
1532 {
1533 	/* If it was marked as used, and not ID 0, decrement local_addr_used */
1534 	if (!__test_and_set_bit(id ? : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap) &&
1535 	    id && !WARN_ON_ONCE(msk->pm.local_addr_used == 0))
1536 		msk->pm.local_addr_used--;
1537 }
1538 
1539 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1540 						   const struct mptcp_pm_addr_entry *entry)
1541 {
1542 	const struct mptcp_addr_info *addr = &entry->addr;
1543 	struct mptcp_rm_list list = { .nr = 0 };
1544 	long s_slot = 0, s_num = 0;
1545 	struct mptcp_sock *msk;
1546 
1547 	pr_debug("remove_id=%d", addr->id);
1548 
1549 	list.ids[list.nr++] = addr->id;
1550 
1551 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1552 		struct sock *sk = (struct sock *)msk;
1553 		bool remove_subflow;
1554 
1555 		if (mptcp_pm_is_userspace(msk))
1556 			goto next;
1557 
1558 		if (list_empty(&msk->conn_list)) {
1559 			mptcp_pm_remove_anno_addr(msk, addr, false);
1560 			goto next;
1561 		}
1562 
1563 		lock_sock(sk);
1564 		remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1565 		mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
1566 					  !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
1567 
1568 		if (remove_subflow) {
1569 			spin_lock_bh(&msk->pm.lock);
1570 			mptcp_pm_nl_rm_subflow_received(msk, &list);
1571 			spin_unlock_bh(&msk->pm.lock);
1572 		}
1573 
1574 		if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1575 			spin_lock_bh(&msk->pm.lock);
1576 			__mark_subflow_endp_available(msk, list.ids[0]);
1577 			spin_unlock_bh(&msk->pm.lock);
1578 		}
1579 
1580 		if (msk->mpc_endpoint_id == entry->addr.id)
1581 			msk->mpc_endpoint_id = 0;
1582 		release_sock(sk);
1583 
1584 next:
1585 		sock_put(sk);
1586 		cond_resched();
1587 	}
1588 
1589 	return 0;
1590 }
1591 
1592 static int mptcp_nl_remove_id_zero_address(struct net *net,
1593 					   struct mptcp_addr_info *addr)
1594 {
1595 	struct mptcp_rm_list list = { .nr = 0 };
1596 	long s_slot = 0, s_num = 0;
1597 	struct mptcp_sock *msk;
1598 
1599 	list.ids[list.nr++] = 0;
1600 
1601 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1602 		struct sock *sk = (struct sock *)msk;
1603 		struct mptcp_addr_info msk_local;
1604 
1605 		if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1606 			goto next;
1607 
1608 		mptcp_local_address((struct sock_common *)msk, &msk_local);
1609 		if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
1610 			goto next;
1611 
1612 		lock_sock(sk);
1613 		spin_lock_bh(&msk->pm.lock);
1614 		mptcp_pm_remove_addr(msk, &list);
1615 		mptcp_pm_nl_rm_subflow_received(msk, &list);
1616 		__mark_subflow_endp_available(msk, 0);
1617 		spin_unlock_bh(&msk->pm.lock);
1618 		release_sock(sk);
1619 
1620 next:
1621 		sock_put(sk);
1622 		cond_resched();
1623 	}
1624 
1625 	return 0;
1626 }
1627 
1628 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1629 {
1630 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1631 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1632 	struct mptcp_pm_addr_entry addr, *entry;
1633 	unsigned int addr_max;
1634 	int ret;
1635 
1636 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1637 	if (ret < 0)
1638 		return ret;
1639 
1640 	/* the zero id address is special: the first address used by the msk
1641 	 * always gets such an id, so different subflows can have different zero
1642 	 * id addresses. Additionally zero id is not accounted for in id_bitmap.
1643 	 * Let's use an 'mptcp_rm_list' instead of the common remove code.
1644 	 */
1645 	if (addr.addr.id == 0)
1646 		return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1647 
1648 	spin_lock_bh(&pernet->lock);
1649 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
1650 	if (!entry) {
1651 		GENL_SET_ERR_MSG(info, "address not found");
1652 		spin_unlock_bh(&pernet->lock);
1653 		return -EINVAL;
1654 	}
1655 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1656 		addr_max = pernet->add_addr_signal_max;
1657 		WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1658 	}
1659 	if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1660 		addr_max = pernet->local_addr_max;
1661 		WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1662 	}
1663 
1664 	pernet->addrs--;
1665 	list_del_rcu(&entry->list);
1666 	__clear_bit(entry->addr.id, pernet->id_bitmap);
1667 	spin_unlock_bh(&pernet->lock);
1668 
1669 	mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry);
1670 	synchronize_rcu();
1671 	__mptcp_pm_release_addr_entry(entry);
1672 
1673 	return ret;
1674 }
1675 
1676 void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
1677 {
1678 	struct mptcp_rm_list alist = { .nr = 0 };
1679 	struct mptcp_pm_addr_entry *entry;
1680 	int anno_nr = 0;
1681 
1682 	list_for_each_entry(entry, rm_list, list) {
1683 		if (alist.nr >= MPTCP_RM_IDS_MAX)
1684 			break;
1685 
1686 		/* only delete if either announced or matching a subflow */
1687 		if (remove_anno_list_by_saddr(msk, &entry->addr))
1688 			anno_nr++;
1689 		else if (!lookup_subflow_by_saddr(&msk->conn_list,
1690 						  &entry->addr))
1691 			continue;
1692 
1693 		alist.ids[alist.nr++] = entry->addr.id;
1694 	}
1695 
1696 	if (alist.nr) {
1697 		spin_lock_bh(&msk->pm.lock);
1698 		msk->pm.add_addr_signaled -= anno_nr;
1699 		mptcp_pm_remove_addr(msk, &alist);
1700 		spin_unlock_bh(&msk->pm.lock);
1701 	}
1702 }
1703 
1704 void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1705 					struct list_head *rm_list)
1706 {
1707 	struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1708 	struct mptcp_pm_addr_entry *entry;
1709 
1710 	list_for_each_entry(entry, rm_list, list) {
1711 		if (slist.nr < MPTCP_RM_IDS_MAX &&
1712 		    lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
1713 			slist.ids[slist.nr++] = entry->addr.id;
1714 
1715 		if (alist.nr < MPTCP_RM_IDS_MAX &&
1716 		    remove_anno_list_by_saddr(msk, &entry->addr))
1717 			alist.ids[alist.nr++] = entry->addr.id;
1718 	}
1719 
1720 	spin_lock_bh(&msk->pm.lock);
1721 	if (alist.nr) {
1722 		msk->pm.add_addr_signaled -= alist.nr;
1723 		mptcp_pm_remove_addr(msk, &alist);
1724 	}
1725 	if (slist.nr)
1726 		mptcp_pm_nl_rm_subflow_received(msk, &slist);
1727 	/* Reset counters: maybe some subflows have been removed before */
1728 	bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1729 	msk->pm.local_addr_used = 0;
1730 	spin_unlock_bh(&msk->pm.lock);
1731 }
1732 
1733 static void mptcp_nl_remove_addrs_list(struct net *net,
1734 				       struct list_head *rm_list)
1735 {
1736 	long s_slot = 0, s_num = 0;
1737 	struct mptcp_sock *msk;
1738 
1739 	if (list_empty(rm_list))
1740 		return;
1741 
1742 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1743 		struct sock *sk = (struct sock *)msk;
1744 
1745 		if (!mptcp_pm_is_userspace(msk)) {
1746 			lock_sock(sk);
1747 			mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1748 			release_sock(sk);
1749 		}
1750 
1751 		sock_put(sk);
1752 		cond_resched();
1753 	}
1754 }
1755 
1756 /* caller must ensure the RCU grace period is already elapsed */
1757 static void __flush_addrs(struct list_head *list)
1758 {
1759 	while (!list_empty(list)) {
1760 		struct mptcp_pm_addr_entry *cur;
1761 
1762 		cur = list_entry(list->next,
1763 				 struct mptcp_pm_addr_entry, list);
1764 		list_del_rcu(&cur->list);
1765 		__mptcp_pm_release_addr_entry(cur);
1766 	}
1767 }
1768 
1769 static void __reset_counters(struct pm_nl_pernet *pernet)
1770 {
1771 	WRITE_ONCE(pernet->add_addr_signal_max, 0);
1772 	WRITE_ONCE(pernet->add_addr_accept_max, 0);
1773 	WRITE_ONCE(pernet->local_addr_max, 0);
1774 	pernet->addrs = 0;
1775 }
1776 
1777 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1778 {
1779 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1780 	LIST_HEAD(free_list);
1781 
1782 	spin_lock_bh(&pernet->lock);
1783 	list_splice_init(&pernet->local_addr_list, &free_list);
1784 	__reset_counters(pernet);
1785 	pernet->next_id = 1;
1786 	bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1787 	spin_unlock_bh(&pernet->lock);
1788 	mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1789 	synchronize_rcu();
1790 	__flush_addrs(&free_list);
1791 	return 0;
1792 }
1793 
1794 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1795 			      struct mptcp_pm_addr_entry *entry)
1796 {
1797 	struct mptcp_addr_info *addr = &entry->addr;
1798 	struct nlattr *attr;
1799 
1800 	attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1801 	if (!attr)
1802 		return -EMSGSIZE;
1803 
1804 	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1805 		goto nla_put_failure;
1806 	if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1807 		goto nla_put_failure;
1808 	if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1809 		goto nla_put_failure;
1810 	if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1811 		goto nla_put_failure;
1812 	if (entry->ifindex &&
1813 	    nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1814 		goto nla_put_failure;
1815 
1816 	if (addr->family == AF_INET &&
1817 	    nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1818 			    addr->addr.s_addr))
1819 		goto nla_put_failure;
1820 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1821 	else if (addr->family == AF_INET6 &&
1822 		 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1823 		goto nla_put_failure;
1824 #endif
1825 	nla_nest_end(skb, attr);
1826 	return 0;
1827 
1828 nla_put_failure:
1829 	nla_nest_cancel(skb, attr);
1830 	return -EMSGSIZE;
1831 }
1832 
1833 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1834 {
1835 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1836 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1837 	struct mptcp_pm_addr_entry addr, *entry;
1838 	struct sk_buff *msg;
1839 	void *reply;
1840 	int ret;
1841 
1842 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1843 	if (ret < 0)
1844 		return ret;
1845 
1846 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1847 	if (!msg)
1848 		return -ENOMEM;
1849 
1850 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1851 				  info->genlhdr->cmd);
1852 	if (!reply) {
1853 		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1854 		ret = -EMSGSIZE;
1855 		goto fail;
1856 	}
1857 
1858 	spin_lock_bh(&pernet->lock);
1859 	entry = __lookup_addr_by_id(pernet, addr.addr.id);
1860 	if (!entry) {
1861 		GENL_SET_ERR_MSG(info, "address not found");
1862 		ret = -EINVAL;
1863 		goto unlock_fail;
1864 	}
1865 
1866 	ret = mptcp_nl_fill_addr(msg, entry);
1867 	if (ret)
1868 		goto unlock_fail;
1869 
1870 	genlmsg_end(msg, reply);
1871 	ret = genlmsg_reply(msg, info);
1872 	spin_unlock_bh(&pernet->lock);
1873 	return ret;
1874 
1875 unlock_fail:
1876 	spin_unlock_bh(&pernet->lock);
1877 
1878 fail:
1879 	nlmsg_free(msg);
1880 	return ret;
1881 }
1882 
1883 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1884 				   struct netlink_callback *cb)
1885 {
1886 	struct net *net = sock_net(msg->sk);
1887 	struct mptcp_pm_addr_entry *entry;
1888 	struct pm_nl_pernet *pernet;
1889 	int id = cb->args[0];
1890 	void *hdr;
1891 	int i;
1892 
1893 	pernet = pm_nl_get_pernet(net);
1894 
1895 	spin_lock_bh(&pernet->lock);
1896 	for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1897 		if (test_bit(i, pernet->id_bitmap)) {
1898 			entry = __lookup_addr_by_id(pernet, i);
1899 			if (!entry)
1900 				break;
1901 
1902 			if (entry->addr.id <= id)
1903 				continue;
1904 
1905 			hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1906 					  cb->nlh->nlmsg_seq, &mptcp_genl_family,
1907 					  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1908 			if (!hdr)
1909 				break;
1910 
1911 			if (mptcp_nl_fill_addr(msg, entry) < 0) {
1912 				genlmsg_cancel(msg, hdr);
1913 				break;
1914 			}
1915 
1916 			id = entry->addr.id;
1917 			genlmsg_end(msg, hdr);
1918 		}
1919 	}
1920 	spin_unlock_bh(&pernet->lock);
1921 
1922 	cb->args[0] = id;
1923 	return msg->len;
1924 }
1925 
1926 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1927 {
1928 	struct nlattr *attr = info->attrs[id];
1929 
1930 	if (!attr)
1931 		return 0;
1932 
1933 	*limit = nla_get_u32(attr);
1934 	if (*limit > MPTCP_PM_ADDR_MAX) {
1935 		GENL_SET_ERR_MSG(info, "limit greater than maximum");
1936 		return -EINVAL;
1937 	}
1938 	return 0;
1939 }
1940 
1941 static int
1942 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1943 {
1944 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1945 	unsigned int rcv_addrs, subflows;
1946 	int ret;
1947 
1948 	spin_lock_bh(&pernet->lock);
1949 	rcv_addrs = pernet->add_addr_accept_max;
1950 	ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1951 	if (ret)
1952 		goto unlock;
1953 
1954 	subflows = pernet->subflows_max;
1955 	ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1956 	if (ret)
1957 		goto unlock;
1958 
1959 	WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1960 	WRITE_ONCE(pernet->subflows_max, subflows);
1961 
1962 unlock:
1963 	spin_unlock_bh(&pernet->lock);
1964 	return ret;
1965 }
1966 
1967 static int
1968 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1969 {
1970 	struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1971 	struct sk_buff *msg;
1972 	void *reply;
1973 
1974 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1975 	if (!msg)
1976 		return -ENOMEM;
1977 
1978 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1979 				  MPTCP_PM_CMD_GET_LIMITS);
1980 	if (!reply)
1981 		goto fail;
1982 
1983 	if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1984 			READ_ONCE(pernet->add_addr_accept_max)))
1985 		goto fail;
1986 
1987 	if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1988 			READ_ONCE(pernet->subflows_max)))
1989 		goto fail;
1990 
1991 	genlmsg_end(msg, reply);
1992 	return genlmsg_reply(msg, info);
1993 
1994 fail:
1995 	GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1996 	nlmsg_free(msg);
1997 	return -EMSGSIZE;
1998 }
1999 
2000 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
2001 				 struct mptcp_addr_info *addr)
2002 {
2003 	struct mptcp_rm_list list = { .nr = 0 };
2004 
2005 	list.ids[list.nr++] = addr->id;
2006 
2007 	spin_lock_bh(&msk->pm.lock);
2008 	mptcp_pm_nl_rm_subflow_received(msk, &list);
2009 	__mark_subflow_endp_available(msk, list.ids[0]);
2010 	mptcp_pm_create_subflow_or_signal_addr(msk);
2011 	spin_unlock_bh(&msk->pm.lock);
2012 }
2013 
2014 static int mptcp_nl_set_flags(struct net *net,
2015 			      struct mptcp_addr_info *addr,
2016 			      u8 bkup, u8 changed)
2017 {
2018 	long s_slot = 0, s_num = 0;
2019 	struct mptcp_sock *msk;
2020 	int ret = -EINVAL;
2021 
2022 	while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
2023 		struct sock *sk = (struct sock *)msk;
2024 
2025 		if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
2026 			goto next;
2027 
2028 		lock_sock(sk);
2029 		if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
2030 			ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
2031 		if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
2032 			mptcp_pm_nl_fullmesh(msk, addr);
2033 		release_sock(sk);
2034 
2035 next:
2036 		sock_put(sk);
2037 		cond_resched();
2038 	}
2039 
2040 	return ret;
2041 }
2042 
2043 int mptcp_pm_nl_set_flags(struct net *net, struct mptcp_pm_addr_entry *addr, u8 bkup)
2044 {
2045 	struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2046 	u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
2047 			   MPTCP_PM_ADDR_FLAG_FULLMESH;
2048 	struct mptcp_pm_addr_entry *entry;
2049 	u8 lookup_by_id = 0;
2050 
2051 	if (addr->addr.family == AF_UNSPEC) {
2052 		lookup_by_id = 1;
2053 		if (!addr->addr.id)
2054 			return -EOPNOTSUPP;
2055 	}
2056 
2057 	spin_lock_bh(&pernet->lock);
2058 	entry = __lookup_addr(pernet, &addr->addr, lookup_by_id);
2059 	if (!entry) {
2060 		spin_unlock_bh(&pernet->lock);
2061 		return -EINVAL;
2062 	}
2063 	if ((addr->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
2064 	    (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
2065 		spin_unlock_bh(&pernet->lock);
2066 		return -EINVAL;
2067 	}
2068 
2069 	changed = (addr->flags ^ entry->flags) & mask;
2070 	entry->flags = (entry->flags & ~mask) | (addr->flags & mask);
2071 	*addr = *entry;
2072 	spin_unlock_bh(&pernet->lock);
2073 
2074 	mptcp_nl_set_flags(net, &addr->addr, bkup, changed);
2075 	return 0;
2076 }
2077 
2078 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
2079 {
2080 	struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, };
2081 	struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
2082 	struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
2083 	struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
2084 	struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
2085 	struct net *net = sock_net(skb->sk);
2086 	u8 bkup = 0;
2087 	int ret;
2088 
2089 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
2090 	if (ret < 0)
2091 		return ret;
2092 
2093 	if (attr_rem) {
2094 		ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote);
2095 		if (ret < 0)
2096 			return ret;
2097 	}
2098 
2099 	if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
2100 		bkup = 1;
2101 
2102 	return mptcp_pm_set_flags(net, token, &addr, &remote, bkup);
2103 }
2104 
2105 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
2106 {
2107 	genlmsg_multicast_netns(&mptcp_genl_family, net,
2108 				nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
2109 }
2110 
2111 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)
2112 {
2113 	return genl_has_listeners(&mptcp_genl_family,
2114 				  sock_net((const struct sock *)msk),
2115 				  MPTCP_PM_EV_GRP_OFFSET);
2116 }
2117 
2118 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
2119 {
2120 	const struct inet_sock *issk = inet_sk(ssk);
2121 	const struct mptcp_subflow_context *sf;
2122 
2123 	if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2124 		return -EMSGSIZE;
2125 
2126 	switch (ssk->sk_family) {
2127 	case AF_INET:
2128 		if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2129 			return -EMSGSIZE;
2130 		if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
2131 			return -EMSGSIZE;
2132 		break;
2133 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2134 	case AF_INET6: {
2135 		const struct ipv6_pinfo *np = inet6_sk(ssk);
2136 
2137 		if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2138 			return -EMSGSIZE;
2139 		if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
2140 			return -EMSGSIZE;
2141 		break;
2142 	}
2143 #endif
2144 	default:
2145 		WARN_ON_ONCE(1);
2146 		return -EMSGSIZE;
2147 	}
2148 
2149 	if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2150 		return -EMSGSIZE;
2151 	if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
2152 		return -EMSGSIZE;
2153 
2154 	sf = mptcp_subflow_ctx(ssk);
2155 	if (WARN_ON_ONCE(!sf))
2156 		return -EINVAL;
2157 
2158 	if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf)))
2159 		return -EMSGSIZE;
2160 
2161 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
2162 		return -EMSGSIZE;
2163 
2164 	return 0;
2165 }
2166 
2167 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
2168 					 const struct mptcp_sock *msk,
2169 					 const struct sock *ssk)
2170 {
2171 	const struct sock *sk = (const struct sock *)msk;
2172 	const struct mptcp_subflow_context *sf;
2173 	u8 sk_err;
2174 
2175 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2176 		return -EMSGSIZE;
2177 
2178 	if (mptcp_event_add_subflow(skb, ssk))
2179 		return -EMSGSIZE;
2180 
2181 	sf = mptcp_subflow_ctx(ssk);
2182 	if (WARN_ON_ONCE(!sf))
2183 		return -EINVAL;
2184 
2185 	if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
2186 		return -EMSGSIZE;
2187 
2188 	if (ssk->sk_bound_dev_if &&
2189 	    nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
2190 		return -EMSGSIZE;
2191 
2192 	sk_err = READ_ONCE(ssk->sk_err);
2193 	if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
2194 	    nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
2195 		return -EMSGSIZE;
2196 
2197 	return 0;
2198 }
2199 
2200 static int mptcp_event_sub_established(struct sk_buff *skb,
2201 				       const struct mptcp_sock *msk,
2202 				       const struct sock *ssk)
2203 {
2204 	return mptcp_event_put_token_and_ssk(skb, msk, ssk);
2205 }
2206 
2207 static int mptcp_event_sub_closed(struct sk_buff *skb,
2208 				  const struct mptcp_sock *msk,
2209 				  const struct sock *ssk)
2210 {
2211 	const struct mptcp_subflow_context *sf;
2212 
2213 	if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
2214 		return -EMSGSIZE;
2215 
2216 	sf = mptcp_subflow_ctx(ssk);
2217 	if (!sf->reset_seen)
2218 		return 0;
2219 
2220 	if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
2221 		return -EMSGSIZE;
2222 
2223 	if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
2224 		return -EMSGSIZE;
2225 
2226 	return 0;
2227 }
2228 
2229 static int mptcp_event_created(struct sk_buff *skb,
2230 			       const struct mptcp_sock *msk,
2231 			       const struct sock *ssk)
2232 {
2233 	int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
2234 
2235 	if (err)
2236 		return err;
2237 
2238 	if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
2239 		return -EMSGSIZE;
2240 
2241 	return mptcp_event_add_subflow(skb, ssk);
2242 }
2243 
2244 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
2245 {
2246 	struct net *net = sock_net((const struct sock *)msk);
2247 	struct nlmsghdr *nlh;
2248 	struct sk_buff *skb;
2249 
2250 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2251 		return;
2252 
2253 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2254 	if (!skb)
2255 		return;
2256 
2257 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
2258 	if (!nlh)
2259 		goto nla_put_failure;
2260 
2261 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2262 		goto nla_put_failure;
2263 
2264 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
2265 		goto nla_put_failure;
2266 
2267 	genlmsg_end(skb, nlh);
2268 	mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2269 	return;
2270 
2271 nla_put_failure:
2272 	nlmsg_free(skb);
2273 }
2274 
2275 void mptcp_event_addr_announced(const struct sock *ssk,
2276 				const struct mptcp_addr_info *info)
2277 {
2278 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
2279 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
2280 	struct net *net = sock_net(ssk);
2281 	struct nlmsghdr *nlh;
2282 	struct sk_buff *skb;
2283 
2284 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2285 		return;
2286 
2287 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2288 	if (!skb)
2289 		return;
2290 
2291 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
2292 			  MPTCP_EVENT_ANNOUNCED);
2293 	if (!nlh)
2294 		goto nla_put_failure;
2295 
2296 	if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2297 		goto nla_put_failure;
2298 
2299 	if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2300 		goto nla_put_failure;
2301 
2302 	if (nla_put_be16(skb, MPTCP_ATTR_DPORT,
2303 			 info->port == 0 ?
2304 			 inet_sk(ssk)->inet_dport :
2305 			 info->port))
2306 		goto nla_put_failure;
2307 
2308 	switch (info->family) {
2309 	case AF_INET:
2310 		if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2311 			goto nla_put_failure;
2312 		break;
2313 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2314 	case AF_INET6:
2315 		if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2316 			goto nla_put_failure;
2317 		break;
2318 #endif
2319 	default:
2320 		WARN_ON_ONCE(1);
2321 		goto nla_put_failure;
2322 	}
2323 
2324 	genlmsg_end(skb, nlh);
2325 	mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2326 	return;
2327 
2328 nla_put_failure:
2329 	nlmsg_free(skb);
2330 }
2331 
2332 void mptcp_event_pm_listener(const struct sock *ssk,
2333 			     enum mptcp_event_type event)
2334 {
2335 	const struct inet_sock *issk = inet_sk(ssk);
2336 	struct net *net = sock_net(ssk);
2337 	struct nlmsghdr *nlh;
2338 	struct sk_buff *skb;
2339 
2340 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2341 		return;
2342 
2343 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
2344 	if (!skb)
2345 		return;
2346 
2347 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event);
2348 	if (!nlh)
2349 		goto nla_put_failure;
2350 
2351 	if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2352 		goto nla_put_failure;
2353 
2354 	if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2355 		goto nla_put_failure;
2356 
2357 	switch (ssk->sk_family) {
2358 	case AF_INET:
2359 		if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2360 			goto nla_put_failure;
2361 		break;
2362 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2363 	case AF_INET6: {
2364 		const struct ipv6_pinfo *np = inet6_sk(ssk);
2365 
2366 		if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2367 			goto nla_put_failure;
2368 		break;
2369 	}
2370 #endif
2371 	default:
2372 		WARN_ON_ONCE(1);
2373 		goto nla_put_failure;
2374 	}
2375 
2376 	genlmsg_end(skb, nlh);
2377 	mptcp_nl_mcast_send(net, skb, GFP_KERNEL);
2378 	return;
2379 
2380 nla_put_failure:
2381 	nlmsg_free(skb);
2382 }
2383 
2384 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2385 		 const struct sock *ssk, gfp_t gfp)
2386 {
2387 	struct net *net = sock_net((const struct sock *)msk);
2388 	struct nlmsghdr *nlh;
2389 	struct sk_buff *skb;
2390 
2391 	if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2392 		return;
2393 
2394 	skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2395 	if (!skb)
2396 		return;
2397 
2398 	nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2399 	if (!nlh)
2400 		goto nla_put_failure;
2401 
2402 	switch (type) {
2403 	case MPTCP_EVENT_UNSPEC:
2404 		WARN_ON_ONCE(1);
2405 		break;
2406 	case MPTCP_EVENT_CREATED:
2407 	case MPTCP_EVENT_ESTABLISHED:
2408 		if (mptcp_event_created(skb, msk, ssk) < 0)
2409 			goto nla_put_failure;
2410 		break;
2411 	case MPTCP_EVENT_CLOSED:
2412 		if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
2413 			goto nla_put_failure;
2414 		break;
2415 	case MPTCP_EVENT_ANNOUNCED:
2416 	case MPTCP_EVENT_REMOVED:
2417 		/* call mptcp_event_addr_announced()/removed instead */
2418 		WARN_ON_ONCE(1);
2419 		break;
2420 	case MPTCP_EVENT_SUB_ESTABLISHED:
2421 	case MPTCP_EVENT_SUB_PRIORITY:
2422 		if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2423 			goto nla_put_failure;
2424 		break;
2425 	case MPTCP_EVENT_SUB_CLOSED:
2426 		if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2427 			goto nla_put_failure;
2428 		break;
2429 	case MPTCP_EVENT_LISTENER_CREATED:
2430 	case MPTCP_EVENT_LISTENER_CLOSED:
2431 		break;
2432 	}
2433 
2434 	genlmsg_end(skb, nlh);
2435 	mptcp_nl_mcast_send(net, skb, gfp);
2436 	return;
2437 
2438 nla_put_failure:
2439 	nlmsg_free(skb);
2440 }
2441 
2442 static const struct genl_small_ops mptcp_pm_ops[] = {
2443 	{
2444 		.cmd    = MPTCP_PM_CMD_ADD_ADDR,
2445 		.doit   = mptcp_nl_cmd_add_addr,
2446 		.flags  = GENL_UNS_ADMIN_PERM,
2447 	},
2448 	{
2449 		.cmd    = MPTCP_PM_CMD_DEL_ADDR,
2450 		.doit   = mptcp_nl_cmd_del_addr,
2451 		.flags  = GENL_UNS_ADMIN_PERM,
2452 	},
2453 	{
2454 		.cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
2455 		.doit   = mptcp_nl_cmd_flush_addrs,
2456 		.flags  = GENL_UNS_ADMIN_PERM,
2457 	},
2458 	{
2459 		.cmd    = MPTCP_PM_CMD_GET_ADDR,
2460 		.doit   = mptcp_nl_cmd_get_addr,
2461 		.dumpit   = mptcp_nl_cmd_dump_addrs,
2462 	},
2463 	{
2464 		.cmd    = MPTCP_PM_CMD_SET_LIMITS,
2465 		.doit   = mptcp_nl_cmd_set_limits,
2466 		.flags  = GENL_UNS_ADMIN_PERM,
2467 	},
2468 	{
2469 		.cmd    = MPTCP_PM_CMD_GET_LIMITS,
2470 		.doit   = mptcp_nl_cmd_get_limits,
2471 	},
2472 	{
2473 		.cmd    = MPTCP_PM_CMD_SET_FLAGS,
2474 		.doit   = mptcp_nl_cmd_set_flags,
2475 		.flags  = GENL_UNS_ADMIN_PERM,
2476 	},
2477 	{
2478 		.cmd    = MPTCP_PM_CMD_ANNOUNCE,
2479 		.doit   = mptcp_nl_cmd_announce,
2480 		.flags  = GENL_UNS_ADMIN_PERM,
2481 	},
2482 	{
2483 		.cmd    = MPTCP_PM_CMD_REMOVE,
2484 		.doit   = mptcp_nl_cmd_remove,
2485 		.flags  = GENL_UNS_ADMIN_PERM,
2486 	},
2487 	{
2488 		.cmd    = MPTCP_PM_CMD_SUBFLOW_CREATE,
2489 		.doit   = mptcp_nl_cmd_sf_create,
2490 		.flags  = GENL_UNS_ADMIN_PERM,
2491 	},
2492 	{
2493 		.cmd    = MPTCP_PM_CMD_SUBFLOW_DESTROY,
2494 		.doit   = mptcp_nl_cmd_sf_destroy,
2495 		.flags  = GENL_UNS_ADMIN_PERM,
2496 	},
2497 };
2498 
2499 static struct genl_family mptcp_genl_family __ro_after_init = {
2500 	.name		= MPTCP_PM_NAME,
2501 	.version	= MPTCP_PM_VER,
2502 	.maxattr	= MPTCP_PM_ATTR_MAX,
2503 	.policy		= mptcp_pm_policy,
2504 	.netnsok	= true,
2505 	.module		= THIS_MODULE,
2506 	.small_ops	= mptcp_pm_ops,
2507 	.n_small_ops	= ARRAY_SIZE(mptcp_pm_ops),
2508 	.resv_start_op	= MPTCP_PM_CMD_SUBFLOW_DESTROY + 1,
2509 	.mcgrps		= mptcp_pm_mcgrps,
2510 	.n_mcgrps	= ARRAY_SIZE(mptcp_pm_mcgrps),
2511 };
2512 
2513 static int __net_init pm_nl_init_net(struct net *net)
2514 {
2515 	struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2516 
2517 	INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2518 
2519 	/* Cit. 2 subflows ought to be enough for anybody. */
2520 	pernet->subflows_max = 2;
2521 	pernet->next_id = 1;
2522 	pernet->stale_loss_cnt = 4;
2523 	spin_lock_init(&pernet->lock);
2524 
2525 	/* No need to initialize other pernet fields, the struct is zeroed at
2526 	 * allocation time.
2527 	 */
2528 
2529 	return 0;
2530 }
2531 
2532 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2533 {
2534 	struct net *net;
2535 
2536 	list_for_each_entry(net, net_list, exit_list) {
2537 		struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2538 
2539 		/* net is removed from namespace list, can't race with
2540 		 * other modifiers, also netns core already waited for a
2541 		 * RCU grace period.
2542 		 */
2543 		__flush_addrs(&pernet->local_addr_list);
2544 	}
2545 }
2546 
2547 static struct pernet_operations mptcp_pm_pernet_ops = {
2548 	.init = pm_nl_init_net,
2549 	.exit_batch = pm_nl_exit_net,
2550 	.id = &pm_nl_pernet_id,
2551 	.size = sizeof(struct pm_nl_pernet),
2552 };
2553 
2554 void __init mptcp_pm_nl_init(void)
2555 {
2556 	if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2557 		panic("Failed to register MPTCP PM pernet subsystem.\n");
2558 
2559 	if (genl_register_family(&mptcp_genl_family))
2560 		panic("Failed to register MPTCP PM netlink family\n");
2561 }
2562