xref: /linux/net/mptcp/pm.c (revision 1cc3462159babb69c84c39cb1b4e262aef3ea325)
1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3  *
4  * Copyright (c) 2019, Intel Corporation.
5  */
6 #define pr_fmt(fmt) "MPTCP: " fmt
7 
8 #include <linux/kernel.h>
9 #include <net/mptcp.h>
10 #include "protocol.h"
11 
12 #include "mib.h"
13 #include "mptcp_pm_gen.h"
14 
15 /* path manager command handlers */
16 
17 int mptcp_pm_announce_addr(struct mptcp_sock *msk,
18 			   const struct mptcp_addr_info *addr,
19 			   bool echo)
20 {
21 	u8 add_addr = READ_ONCE(msk->pm.addr_signal);
22 
23 	pr_debug("msk=%p, local_id=%d, echo=%d\n", msk, addr->id, echo);
24 
25 	lockdep_assert_held(&msk->pm.lock);
26 
27 	if (add_addr &
28 	    (echo ? BIT(MPTCP_ADD_ADDR_ECHO) : BIT(MPTCP_ADD_ADDR_SIGNAL))) {
29 		MPTCP_INC_STATS(sock_net((struct sock *)msk),
30 				echo ? MPTCP_MIB_ECHOADDTXDROP : MPTCP_MIB_ADDADDRTXDROP);
31 		return -EINVAL;
32 	}
33 
34 	if (echo) {
35 		msk->pm.remote = *addr;
36 		add_addr |= BIT(MPTCP_ADD_ADDR_ECHO);
37 	} else {
38 		msk->pm.local = *addr;
39 		add_addr |= BIT(MPTCP_ADD_ADDR_SIGNAL);
40 	}
41 	WRITE_ONCE(msk->pm.addr_signal, add_addr);
42 	return 0;
43 }
44 
45 int mptcp_pm_remove_addr(struct mptcp_sock *msk, const struct mptcp_rm_list *rm_list)
46 {
47 	u8 rm_addr = READ_ONCE(msk->pm.addr_signal);
48 
49 	pr_debug("msk=%p, rm_list_nr=%d\n", msk, rm_list->nr);
50 
51 	if (rm_addr) {
52 		MPTCP_ADD_STATS(sock_net((struct sock *)msk),
53 				MPTCP_MIB_RMADDRTXDROP, rm_list->nr);
54 		return -EINVAL;
55 	}
56 
57 	msk->pm.rm_list_tx = *rm_list;
58 	rm_addr |= BIT(MPTCP_RM_ADDR_SIGNAL);
59 	WRITE_ONCE(msk->pm.addr_signal, rm_addr);
60 	mptcp_pm_nl_addr_send_ack(msk);
61 	return 0;
62 }
63 
64 /* path manager event handlers */
65 
66 void mptcp_pm_new_connection(struct mptcp_sock *msk, const struct sock *ssk, int server_side)
67 {
68 	struct mptcp_pm_data *pm = &msk->pm;
69 
70 	pr_debug("msk=%p, token=%u side=%d\n", msk, READ_ONCE(msk->token), server_side);
71 
72 	WRITE_ONCE(pm->server_side, server_side);
73 	mptcp_event(MPTCP_EVENT_CREATED, msk, ssk, GFP_ATOMIC);
74 }
75 
76 bool mptcp_pm_allow_new_subflow(struct mptcp_sock *msk)
77 {
78 	struct mptcp_pm_data *pm = &msk->pm;
79 	unsigned int subflows_max;
80 	int ret = 0;
81 
82 	if (mptcp_pm_is_userspace(msk)) {
83 		if (mptcp_userspace_pm_active(msk)) {
84 			spin_lock_bh(&pm->lock);
85 			pm->subflows++;
86 			spin_unlock_bh(&pm->lock);
87 			return true;
88 		}
89 		return false;
90 	}
91 
92 	subflows_max = mptcp_pm_get_subflows_max(msk);
93 
94 	pr_debug("msk=%p subflows=%d max=%d allow=%d\n", msk, pm->subflows,
95 		 subflows_max, READ_ONCE(pm->accept_subflow));
96 
97 	/* try to avoid acquiring the lock below */
98 	if (!READ_ONCE(pm->accept_subflow))
99 		return false;
100 
101 	spin_lock_bh(&pm->lock);
102 	if (READ_ONCE(pm->accept_subflow)) {
103 		ret = pm->subflows < subflows_max;
104 		if (ret && ++pm->subflows == subflows_max)
105 			WRITE_ONCE(pm->accept_subflow, false);
106 	}
107 	spin_unlock_bh(&pm->lock);
108 
109 	return ret;
110 }
111 
112 /* return true if the new status bit is currently cleared, that is, this event
113  * can be server, eventually by an already scheduled work
114  */
115 static bool mptcp_pm_schedule_work(struct mptcp_sock *msk,
116 				   enum mptcp_pm_status new_status)
117 {
118 	pr_debug("msk=%p status=%x new=%lx\n", msk, msk->pm.status,
119 		 BIT(new_status));
120 	if (msk->pm.status & BIT(new_status))
121 		return false;
122 
123 	msk->pm.status |= BIT(new_status);
124 	mptcp_schedule_work((struct sock *)msk);
125 	return true;
126 }
127 
128 void mptcp_pm_fully_established(struct mptcp_sock *msk, const struct sock *ssk)
129 {
130 	struct mptcp_pm_data *pm = &msk->pm;
131 	bool announce = false;
132 
133 	pr_debug("msk=%p\n", msk);
134 
135 	spin_lock_bh(&pm->lock);
136 
137 	/* mptcp_pm_fully_established() can be invoked by multiple
138 	 * racing paths - accept() and check_fully_established()
139 	 * be sure to serve this event only once.
140 	 */
141 	if (READ_ONCE(pm->work_pending) &&
142 	    !(msk->pm.status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)))
143 		mptcp_pm_schedule_work(msk, MPTCP_PM_ESTABLISHED);
144 
145 	if ((msk->pm.status & BIT(MPTCP_PM_ALREADY_ESTABLISHED)) == 0)
146 		announce = true;
147 
148 	msk->pm.status |= BIT(MPTCP_PM_ALREADY_ESTABLISHED);
149 	spin_unlock_bh(&pm->lock);
150 
151 	if (announce)
152 		mptcp_event(MPTCP_EVENT_ESTABLISHED, msk, ssk, GFP_ATOMIC);
153 }
154 
155 void mptcp_pm_connection_closed(struct mptcp_sock *msk)
156 {
157 	pr_debug("msk=%p\n", msk);
158 
159 	if (msk->token)
160 		mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL);
161 }
162 
163 void mptcp_pm_subflow_established(struct mptcp_sock *msk)
164 {
165 	struct mptcp_pm_data *pm = &msk->pm;
166 
167 	pr_debug("msk=%p\n", msk);
168 
169 	if (!READ_ONCE(pm->work_pending))
170 		return;
171 
172 	spin_lock_bh(&pm->lock);
173 
174 	if (READ_ONCE(pm->work_pending))
175 		mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
176 
177 	spin_unlock_bh(&pm->lock);
178 }
179 
180 void mptcp_pm_subflow_check_next(struct mptcp_sock *msk,
181 				 const struct mptcp_subflow_context *subflow)
182 {
183 	struct mptcp_pm_data *pm = &msk->pm;
184 	bool update_subflows;
185 
186 	update_subflows = subflow->request_join || subflow->mp_join;
187 	if (mptcp_pm_is_userspace(msk)) {
188 		if (update_subflows) {
189 			spin_lock_bh(&pm->lock);
190 			pm->subflows--;
191 			spin_unlock_bh(&pm->lock);
192 		}
193 		return;
194 	}
195 
196 	if (!READ_ONCE(pm->work_pending) && !update_subflows)
197 		return;
198 
199 	spin_lock_bh(&pm->lock);
200 	if (update_subflows)
201 		__mptcp_pm_close_subflow(msk);
202 
203 	/* Even if this subflow is not really established, tell the PM to try
204 	 * to pick the next ones, if possible.
205 	 */
206 	if (mptcp_pm_nl_check_work_pending(msk))
207 		mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
208 
209 	spin_unlock_bh(&pm->lock);
210 }
211 
212 void mptcp_pm_add_addr_received(const struct sock *ssk,
213 				const struct mptcp_addr_info *addr)
214 {
215 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
216 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
217 	struct mptcp_pm_data *pm = &msk->pm;
218 
219 	pr_debug("msk=%p remote_id=%d accept=%d\n", msk, addr->id,
220 		 READ_ONCE(pm->accept_addr));
221 
222 	mptcp_event_addr_announced(ssk, addr);
223 
224 	spin_lock_bh(&pm->lock);
225 
226 	if (mptcp_pm_is_userspace(msk)) {
227 		if (mptcp_userspace_pm_active(msk)) {
228 			mptcp_pm_announce_addr(msk, addr, true);
229 			mptcp_pm_add_addr_send_ack(msk);
230 		} else {
231 			__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
232 		}
233 	/* id0 should not have a different address */
234 	} else if ((addr->id == 0 && !mptcp_pm_nl_is_init_remote_addr(msk, addr)) ||
235 		   (addr->id > 0 && !READ_ONCE(pm->accept_addr))) {
236 		mptcp_pm_announce_addr(msk, addr, true);
237 		mptcp_pm_add_addr_send_ack(msk);
238 	} else if (mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_RECEIVED)) {
239 		pm->remote = *addr;
240 	} else {
241 		__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_ADDADDRDROP);
242 	}
243 
244 	spin_unlock_bh(&pm->lock);
245 }
246 
247 void mptcp_pm_add_addr_echoed(struct mptcp_sock *msk,
248 			      const struct mptcp_addr_info *addr)
249 {
250 	struct mptcp_pm_data *pm = &msk->pm;
251 
252 	pr_debug("msk=%p\n", msk);
253 
254 	if (!READ_ONCE(pm->work_pending))
255 		return;
256 
257 	spin_lock_bh(&pm->lock);
258 
259 	if (mptcp_lookup_anno_list_by_saddr(msk, addr) && READ_ONCE(pm->work_pending))
260 		mptcp_pm_schedule_work(msk, MPTCP_PM_SUBFLOW_ESTABLISHED);
261 
262 	spin_unlock_bh(&pm->lock);
263 }
264 
265 void mptcp_pm_add_addr_send_ack(struct mptcp_sock *msk)
266 {
267 	if (!mptcp_pm_should_add_signal(msk))
268 		return;
269 
270 	mptcp_pm_schedule_work(msk, MPTCP_PM_ADD_ADDR_SEND_ACK);
271 }
272 
273 void mptcp_pm_rm_addr_received(struct mptcp_sock *msk,
274 			       const struct mptcp_rm_list *rm_list)
275 {
276 	struct mptcp_pm_data *pm = &msk->pm;
277 	u8 i;
278 
279 	pr_debug("msk=%p remote_ids_nr=%d\n", msk, rm_list->nr);
280 
281 	for (i = 0; i < rm_list->nr; i++)
282 		mptcp_event_addr_removed(msk, rm_list->ids[i]);
283 
284 	spin_lock_bh(&pm->lock);
285 	if (mptcp_pm_schedule_work(msk, MPTCP_PM_RM_ADDR_RECEIVED))
286 		pm->rm_list_rx = *rm_list;
287 	else
288 		__MPTCP_INC_STATS(sock_net((struct sock *)msk), MPTCP_MIB_RMADDRDROP);
289 	spin_unlock_bh(&pm->lock);
290 }
291 
292 void mptcp_pm_mp_prio_received(struct sock *ssk, u8 bkup)
293 {
294 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
295 	struct sock *sk = subflow->conn;
296 	struct mptcp_sock *msk;
297 
298 	pr_debug("subflow->backup=%d, bkup=%d\n", subflow->backup, bkup);
299 	msk = mptcp_sk(sk);
300 	if (subflow->backup != bkup)
301 		subflow->backup = bkup;
302 
303 	mptcp_event(MPTCP_EVENT_SUB_PRIORITY, msk, ssk, GFP_ATOMIC);
304 }
305 
306 void mptcp_pm_mp_fail_received(struct sock *sk, u64 fail_seq)
307 {
308 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(sk);
309 	struct mptcp_sock *msk = mptcp_sk(subflow->conn);
310 
311 	pr_debug("fail_seq=%llu\n", fail_seq);
312 
313 	if (!READ_ONCE(msk->allow_infinite_fallback))
314 		return;
315 
316 	if (!subflow->fail_tout) {
317 		pr_debug("send MP_FAIL response and infinite map\n");
318 
319 		subflow->send_mp_fail = 1;
320 		subflow->send_infinite_map = 1;
321 		tcp_send_ack(sk);
322 	} else {
323 		pr_debug("MP_FAIL response received\n");
324 		WRITE_ONCE(subflow->fail_tout, 0);
325 	}
326 }
327 
328 /* path manager helpers */
329 
330 bool mptcp_pm_add_addr_signal(struct mptcp_sock *msk, const struct sk_buff *skb,
331 			      unsigned int opt_size, unsigned int remaining,
332 			      struct mptcp_addr_info *addr, bool *echo,
333 			      bool *drop_other_suboptions)
334 {
335 	int ret = false;
336 	u8 add_addr;
337 	u8 family;
338 	bool port;
339 
340 	spin_lock_bh(&msk->pm.lock);
341 
342 	/* double check after the lock is acquired */
343 	if (!mptcp_pm_should_add_signal(msk))
344 		goto out_unlock;
345 
346 	/* always drop every other options for pure ack ADD_ADDR; this is a
347 	 * plain dup-ack from TCP perspective. The other MPTCP-relevant info,
348 	 * if any, will be carried by the 'original' TCP ack
349 	 */
350 	if (skb && skb_is_tcp_pure_ack(skb)) {
351 		remaining += opt_size;
352 		*drop_other_suboptions = true;
353 	}
354 
355 	*echo = mptcp_pm_should_add_signal_echo(msk);
356 	port = !!(*echo ? msk->pm.remote.port : msk->pm.local.port);
357 
358 	family = *echo ? msk->pm.remote.family : msk->pm.local.family;
359 	if (remaining < mptcp_add_addr_len(family, *echo, port))
360 		goto out_unlock;
361 
362 	if (*echo) {
363 		*addr = msk->pm.remote;
364 		add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_ECHO);
365 	} else {
366 		*addr = msk->pm.local;
367 		add_addr = msk->pm.addr_signal & ~BIT(MPTCP_ADD_ADDR_SIGNAL);
368 	}
369 	WRITE_ONCE(msk->pm.addr_signal, add_addr);
370 	ret = true;
371 
372 out_unlock:
373 	spin_unlock_bh(&msk->pm.lock);
374 	return ret;
375 }
376 
377 bool mptcp_pm_rm_addr_signal(struct mptcp_sock *msk, unsigned int remaining,
378 			     struct mptcp_rm_list *rm_list)
379 {
380 	int ret = false, len;
381 	u8 rm_addr;
382 
383 	spin_lock_bh(&msk->pm.lock);
384 
385 	/* double check after the lock is acquired */
386 	if (!mptcp_pm_should_rm_signal(msk))
387 		goto out_unlock;
388 
389 	rm_addr = msk->pm.addr_signal & ~BIT(MPTCP_RM_ADDR_SIGNAL);
390 	len = mptcp_rm_addr_len(&msk->pm.rm_list_tx);
391 	if (len < 0) {
392 		WRITE_ONCE(msk->pm.addr_signal, rm_addr);
393 		goto out_unlock;
394 	}
395 	if (remaining < len)
396 		goto out_unlock;
397 
398 	*rm_list = msk->pm.rm_list_tx;
399 	WRITE_ONCE(msk->pm.addr_signal, rm_addr);
400 	ret = true;
401 
402 out_unlock:
403 	spin_unlock_bh(&msk->pm.lock);
404 	return ret;
405 }
406 
407 int mptcp_pm_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
408 {
409 	struct mptcp_addr_info skc_local;
410 	struct mptcp_addr_info msk_local;
411 
412 	if (WARN_ON_ONCE(!msk))
413 		return -1;
414 
415 	/* The 0 ID mapping is defined by the first subflow, copied into the msk
416 	 * addr
417 	 */
418 	mptcp_local_address((struct sock_common *)msk, &msk_local);
419 	mptcp_local_address((struct sock_common *)skc, &skc_local);
420 	if (mptcp_addresses_equal(&msk_local, &skc_local, false))
421 		return 0;
422 
423 	if (mptcp_pm_is_userspace(msk))
424 		return mptcp_userspace_pm_get_local_id(msk, &skc_local);
425 	return mptcp_pm_nl_get_local_id(msk, &skc_local);
426 }
427 
428 bool mptcp_pm_is_backup(struct mptcp_sock *msk, struct sock_common *skc)
429 {
430 	struct mptcp_addr_info skc_local;
431 
432 	mptcp_local_address((struct sock_common *)skc, &skc_local);
433 
434 	if (mptcp_pm_is_userspace(msk))
435 		return mptcp_userspace_pm_is_backup(msk, &skc_local);
436 
437 	return mptcp_pm_nl_is_backup(msk, &skc_local);
438 }
439 
440 static int mptcp_pm_get_addr(u8 id, struct mptcp_pm_addr_entry *addr,
441 			     struct genl_info *info)
442 {
443 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
444 		return mptcp_userspace_pm_get_addr(id, addr, info);
445 	return mptcp_pm_nl_get_addr(id, addr, info);
446 }
447 
448 int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
449 {
450 	struct mptcp_pm_addr_entry addr;
451 	struct nlattr *attr;
452 	struct sk_buff *msg;
453 	void *reply;
454 	int ret;
455 
456 	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR))
457 		return -EINVAL;
458 
459 	attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
460 	ret = mptcp_pm_parse_entry(attr, info, false, &addr);
461 	if (ret < 0)
462 		return ret;
463 
464 	msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
465 	if (!msg)
466 		return -ENOMEM;
467 
468 	reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
469 				  info->genlhdr->cmd);
470 	if (!reply) {
471 		GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
472 		ret = -EMSGSIZE;
473 		goto fail;
474 	}
475 
476 	ret = mptcp_pm_get_addr(addr.addr.id, &addr, info);
477 	if (ret) {
478 		NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found");
479 		goto fail;
480 	}
481 
482 	ret = mptcp_nl_fill_addr(msg, &addr);
483 	if (ret)
484 		goto fail;
485 
486 	genlmsg_end(msg, reply);
487 	ret = genlmsg_reply(msg, info);
488 	return ret;
489 
490 fail:
491 	nlmsg_free(msg);
492 	return ret;
493 }
494 
495 int mptcp_pm_genl_fill_addr(struct sk_buff *msg,
496 			    struct netlink_callback *cb,
497 			    struct mptcp_pm_addr_entry *entry)
498 {
499 	void *hdr;
500 
501 	hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
502 			  cb->nlh->nlmsg_seq, &mptcp_genl_family,
503 			  NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
504 	if (!hdr)
505 		return -EINVAL;
506 
507 	if (mptcp_nl_fill_addr(msg, entry) < 0) {
508 		genlmsg_cancel(msg, hdr);
509 		return -EINVAL;
510 	}
511 
512 	genlmsg_end(msg, hdr);
513 	return 0;
514 }
515 
516 static int mptcp_pm_dump_addr(struct sk_buff *msg, struct netlink_callback *cb)
517 {
518 	const struct genl_info *info = genl_info_dump(cb);
519 
520 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
521 		return mptcp_userspace_pm_dump_addr(msg, cb);
522 	return mptcp_pm_nl_dump_addr(msg, cb);
523 }
524 
525 int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
526 				struct netlink_callback *cb)
527 {
528 	return mptcp_pm_dump_addr(msg, cb);
529 }
530 
531 static int mptcp_pm_set_flags(struct genl_info *info)
532 {
533 	struct mptcp_pm_addr_entry loc = { .addr = { .family = AF_UNSPEC }, };
534 	struct nlattr *attr_loc;
535 	int ret = -EINVAL;
536 
537 	if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ATTR_ADDR))
538 		return ret;
539 
540 	attr_loc = info->attrs[MPTCP_PM_ATTR_ADDR];
541 	ret = mptcp_pm_parse_entry(attr_loc, info, false, &loc);
542 	if (ret < 0)
543 		return ret;
544 
545 	if (info->attrs[MPTCP_PM_ATTR_TOKEN])
546 		return mptcp_userspace_pm_set_flags(&loc, info);
547 	return mptcp_pm_nl_set_flags(&loc, info);
548 }
549 
550 int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
551 {
552 	return mptcp_pm_set_flags(info);
553 }
554 
555 void mptcp_pm_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
556 {
557 	struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
558 	u32 rcv_tstamp = READ_ONCE(tcp_sk(ssk)->rcv_tstamp);
559 
560 	/* keep track of rtx periods with no progress */
561 	if (!subflow->stale_count) {
562 		subflow->stale_rcv_tstamp = rcv_tstamp;
563 		subflow->stale_count++;
564 	} else if (subflow->stale_rcv_tstamp == rcv_tstamp) {
565 		if (subflow->stale_count < U8_MAX)
566 			subflow->stale_count++;
567 		mptcp_pm_nl_subflow_chk_stale(msk, ssk);
568 	} else {
569 		subflow->stale_count = 0;
570 		mptcp_subflow_set_active(subflow);
571 	}
572 }
573 
574 /* if sk is ipv4 or ipv6_only allows only same-family local and remote addresses,
575  * otherwise allow any matching local/remote pair
576  */
577 bool mptcp_pm_addr_families_match(const struct sock *sk,
578 				  const struct mptcp_addr_info *loc,
579 				  const struct mptcp_addr_info *rem)
580 {
581 	bool mptcp_is_v4 = sk->sk_family == AF_INET;
582 
583 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
584 	bool loc_is_v4 = loc->family == AF_INET || ipv6_addr_v4mapped(&loc->addr6);
585 	bool rem_is_v4 = rem->family == AF_INET || ipv6_addr_v4mapped(&rem->addr6);
586 
587 	if (mptcp_is_v4)
588 		return loc_is_v4 && rem_is_v4;
589 
590 	if (ipv6_only_sock(sk))
591 		return !loc_is_v4 && !rem_is_v4;
592 
593 	return loc_is_v4 == rem_is_v4;
594 #else
595 	return mptcp_is_v4 && loc->family == AF_INET && rem->family == AF_INET;
596 #endif
597 }
598 
599 void mptcp_pm_data_reset(struct mptcp_sock *msk)
600 {
601 	u8 pm_type = mptcp_get_pm_type(sock_net((struct sock *)msk));
602 	struct mptcp_pm_data *pm = &msk->pm;
603 
604 	pm->add_addr_signaled = 0;
605 	pm->add_addr_accepted = 0;
606 	pm->local_addr_used = 0;
607 	pm->subflows = 0;
608 	pm->rm_list_tx.nr = 0;
609 	pm->rm_list_rx.nr = 0;
610 	WRITE_ONCE(pm->pm_type, pm_type);
611 
612 	if (pm_type == MPTCP_PM_TYPE_KERNEL) {
613 		bool subflows_allowed = !!mptcp_pm_get_subflows_max(msk);
614 
615 		/* pm->work_pending must be only be set to 'true' when
616 		 * pm->pm_type is set to MPTCP_PM_TYPE_KERNEL
617 		 */
618 		WRITE_ONCE(pm->work_pending,
619 			   (!!mptcp_pm_get_local_addr_max(msk) &&
620 			    subflows_allowed) ||
621 			   !!mptcp_pm_get_add_addr_signal_max(msk));
622 		WRITE_ONCE(pm->accept_addr,
623 			   !!mptcp_pm_get_add_addr_accept_max(msk) &&
624 			   subflows_allowed);
625 		WRITE_ONCE(pm->accept_subflow, subflows_allowed);
626 	} else {
627 		WRITE_ONCE(pm->work_pending, 0);
628 		WRITE_ONCE(pm->accept_addr, 0);
629 		WRITE_ONCE(pm->accept_subflow, 0);
630 	}
631 
632 	WRITE_ONCE(pm->addr_signal, 0);
633 	WRITE_ONCE(pm->remote_deny_join_id0, false);
634 	pm->status = 0;
635 	bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
636 }
637 
638 void mptcp_pm_data_init(struct mptcp_sock *msk)
639 {
640 	spin_lock_init(&msk->pm.lock);
641 	INIT_LIST_HEAD(&msk->pm.anno_list);
642 	INIT_LIST_HEAD(&msk->pm.userspace_pm_local_addr_list);
643 	mptcp_pm_data_reset(msk);
644 }
645 
646 void __init mptcp_pm_init(void)
647 {
648 	mptcp_pm_nl_init();
649 }
650