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