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