1 // SPDX-License-Identifier: GPL-2.0
2 /* Multipath TCP
3 *
4 * Copyright (c) 2020, Red Hat, Inc.
5 */
6
7 #define pr_fmt(fmt) "MPTCP: " fmt
8
9 #include <linux/inet.h>
10 #include <linux/kernel.h>
11 #include <net/tcp.h>
12 #include <net/inet_common.h>
13 #include <net/netns/generic.h>
14 #include <net/mptcp.h>
15 #include <net/genetlink.h>
16 #include <uapi/linux/mptcp.h>
17
18 #include "protocol.h"
19 #include "mib.h"
20
21 /* forward declaration */
22 static struct genl_family mptcp_genl_family;
23
24 static int pm_nl_pernet_id;
25
26 struct mptcp_pm_add_entry {
27 struct list_head list;
28 struct mptcp_addr_info addr;
29 u8 retrans_times;
30 struct timer_list add_timer;
31 struct mptcp_sock *sock;
32 };
33
34 struct pm_nl_pernet {
35 /* protects pernet updates */
36 spinlock_t lock;
37 struct list_head local_addr_list;
38 unsigned int addrs;
39 unsigned int stale_loss_cnt;
40 unsigned int add_addr_signal_max;
41 unsigned int add_addr_accept_max;
42 unsigned int local_addr_max;
43 unsigned int subflows_max;
44 unsigned int next_id;
45 DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
46 };
47
48 #define MPTCP_PM_ADDR_MAX 8
49 #define ADD_ADDR_RETRANS_MAX 3
50
pm_nl_get_pernet(const struct net * net)51 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
52 {
53 return net_generic(net, pm_nl_pernet_id);
54 }
55
56 static struct pm_nl_pernet *
pm_nl_get_pernet_from_msk(const struct mptcp_sock * msk)57 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
58 {
59 return pm_nl_get_pernet(sock_net((struct sock *)msk));
60 }
61
mptcp_addresses_equal(const struct mptcp_addr_info * a,const struct mptcp_addr_info * b,bool use_port)62 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
63 const struct mptcp_addr_info *b, bool use_port)
64 {
65 bool addr_equals = false;
66
67 if (a->family == b->family) {
68 if (a->family == AF_INET)
69 addr_equals = a->addr.s_addr == b->addr.s_addr;
70 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
71 else
72 addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
73 } else if (a->family == AF_INET) {
74 if (ipv6_addr_v4mapped(&b->addr6))
75 addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
76 } else if (b->family == AF_INET) {
77 if (ipv6_addr_v4mapped(&a->addr6))
78 addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
79 #endif
80 }
81
82 if (!addr_equals)
83 return false;
84 if (!use_port)
85 return true;
86
87 return a->port == b->port;
88 }
89
mptcp_local_address(const struct sock_common * skc,struct mptcp_addr_info * addr)90 void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr)
91 {
92 addr->family = skc->skc_family;
93 addr->port = htons(skc->skc_num);
94 if (addr->family == AF_INET)
95 addr->addr.s_addr = skc->skc_rcv_saddr;
96 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
97 else if (addr->family == AF_INET6)
98 addr->addr6 = skc->skc_v6_rcv_saddr;
99 #endif
100 }
101
remote_address(const struct sock_common * skc,struct mptcp_addr_info * addr)102 static void remote_address(const struct sock_common *skc,
103 struct mptcp_addr_info *addr)
104 {
105 addr->family = skc->skc_family;
106 addr->port = skc->skc_dport;
107 if (addr->family == AF_INET)
108 addr->addr.s_addr = skc->skc_daddr;
109 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
110 else if (addr->family == AF_INET6)
111 addr->addr6 = skc->skc_v6_daddr;
112 #endif
113 }
114
lookup_subflow_by_saddr(const struct list_head * list,const struct mptcp_addr_info * saddr)115 static bool lookup_subflow_by_saddr(const struct list_head *list,
116 const struct mptcp_addr_info *saddr)
117 {
118 struct mptcp_subflow_context *subflow;
119 struct mptcp_addr_info cur;
120 struct sock_common *skc;
121
122 list_for_each_entry(subflow, list, node) {
123 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
124
125 mptcp_local_address(skc, &cur);
126 if (mptcp_addresses_equal(&cur, saddr, saddr->port))
127 return true;
128 }
129
130 return false;
131 }
132
lookup_subflow_by_daddr(const struct list_head * list,const struct mptcp_addr_info * daddr)133 static bool lookup_subflow_by_daddr(const struct list_head *list,
134 const struct mptcp_addr_info *daddr)
135 {
136 struct mptcp_subflow_context *subflow;
137 struct mptcp_addr_info cur;
138
139 list_for_each_entry(subflow, list, node) {
140 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
141
142 if (!((1 << inet_sk_state_load(ssk)) &
143 (TCPF_ESTABLISHED | TCPF_SYN_SENT | TCPF_SYN_RECV)))
144 continue;
145
146 remote_address((struct sock_common *)ssk, &cur);
147 if (mptcp_addresses_equal(&cur, daddr, daddr->port))
148 return true;
149 }
150
151 return false;
152 }
153
154 static bool
select_local_address(const struct pm_nl_pernet * pernet,const struct mptcp_sock * msk,struct mptcp_pm_addr_entry * new_entry)155 select_local_address(const struct pm_nl_pernet *pernet,
156 const struct mptcp_sock *msk,
157 struct mptcp_pm_addr_entry *new_entry)
158 {
159 struct mptcp_pm_addr_entry *entry;
160 bool found = false;
161
162 msk_owned_by_me(msk);
163
164 rcu_read_lock();
165 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
166 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
167 continue;
168
169 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
170 continue;
171
172 *new_entry = *entry;
173 found = true;
174 break;
175 }
176 rcu_read_unlock();
177
178 return found;
179 }
180
181 static bool
select_signal_address(struct pm_nl_pernet * pernet,const struct mptcp_sock * msk,struct mptcp_pm_addr_entry * new_entry)182 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk,
183 struct mptcp_pm_addr_entry *new_entry)
184 {
185 struct mptcp_pm_addr_entry *entry;
186 bool found = false;
187
188 rcu_read_lock();
189 /* do not keep any additional per socket state, just signal
190 * the address list in order.
191 * Note: removal from the local address list during the msk life-cycle
192 * can lead to additional addresses not being announced.
193 */
194 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
195 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
196 continue;
197
198 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
199 continue;
200
201 *new_entry = *entry;
202 found = true;
203 break;
204 }
205 rcu_read_unlock();
206
207 return found;
208 }
209
mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock * msk)210 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk)
211 {
212 const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
213
214 return READ_ONCE(pernet->add_addr_signal_max);
215 }
216 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
217
mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock * msk)218 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk)
219 {
220 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
221
222 return READ_ONCE(pernet->add_addr_accept_max);
223 }
224 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
225
mptcp_pm_get_subflows_max(const struct mptcp_sock * msk)226 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk)
227 {
228 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
229
230 return READ_ONCE(pernet->subflows_max);
231 }
232 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
233
mptcp_pm_get_local_addr_max(const struct mptcp_sock * msk)234 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk)
235 {
236 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
237
238 return READ_ONCE(pernet->local_addr_max);
239 }
240 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
241
mptcp_pm_nl_check_work_pending(struct mptcp_sock * msk)242 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
243 {
244 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
245
246 if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
247 (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
248 MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
249 WRITE_ONCE(msk->pm.work_pending, false);
250 return false;
251 }
252 return true;
253 }
254
255 struct mptcp_pm_add_entry *
mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock * msk,const struct mptcp_addr_info * addr)256 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
257 const struct mptcp_addr_info *addr)
258 {
259 struct mptcp_pm_add_entry *entry;
260
261 lockdep_assert_held(&msk->pm.lock);
262
263 list_for_each_entry(entry, &msk->pm.anno_list, list) {
264 if (mptcp_addresses_equal(&entry->addr, addr, true))
265 return entry;
266 }
267
268 return NULL;
269 }
270
mptcp_pm_sport_in_anno_list(struct mptcp_sock * msk,const struct sock * sk)271 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
272 {
273 struct mptcp_pm_add_entry *entry;
274 struct mptcp_addr_info saddr;
275 bool ret = false;
276
277 mptcp_local_address((struct sock_common *)sk, &saddr);
278
279 spin_lock_bh(&msk->pm.lock);
280 list_for_each_entry(entry, &msk->pm.anno_list, list) {
281 if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
282 ret = true;
283 goto out;
284 }
285 }
286
287 out:
288 spin_unlock_bh(&msk->pm.lock);
289 return ret;
290 }
291
mptcp_pm_add_timer(struct timer_list * timer)292 static void mptcp_pm_add_timer(struct timer_list *timer)
293 {
294 struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
295 struct mptcp_sock *msk = entry->sock;
296 struct sock *sk = (struct sock *)msk;
297
298 pr_debug("msk=%p\n", msk);
299
300 if (!msk)
301 return;
302
303 if (inet_sk_state_load(sk) == TCP_CLOSE)
304 return;
305
306 if (!entry->addr.id)
307 return;
308
309 if (mptcp_pm_should_add_signal_addr(msk)) {
310 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
311 goto out;
312 }
313
314 spin_lock_bh(&msk->pm.lock);
315
316 if (!mptcp_pm_should_add_signal_addr(msk)) {
317 pr_debug("retransmit ADD_ADDR id=%d\n", entry->addr.id);
318 mptcp_pm_announce_addr(msk, &entry->addr, false);
319 mptcp_pm_add_addr_send_ack(msk);
320 entry->retrans_times++;
321 }
322
323 if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
324 sk_reset_timer(sk, timer,
325 jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
326
327 spin_unlock_bh(&msk->pm.lock);
328
329 if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
330 mptcp_pm_subflow_established(msk);
331
332 out:
333 __sock_put(sk);
334 }
335
336 struct mptcp_pm_add_entry *
mptcp_pm_del_add_timer(struct mptcp_sock * msk,const struct mptcp_addr_info * addr,bool check_id)337 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
338 const struct mptcp_addr_info *addr, bool check_id)
339 {
340 struct mptcp_pm_add_entry *entry;
341 struct sock *sk = (struct sock *)msk;
342
343 spin_lock_bh(&msk->pm.lock);
344 entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
345 if (entry && (!check_id || entry->addr.id == addr->id))
346 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
347 spin_unlock_bh(&msk->pm.lock);
348
349 if (entry && (!check_id || entry->addr.id == addr->id))
350 sk_stop_timer_sync(sk, &entry->add_timer);
351
352 return entry;
353 }
354
mptcp_pm_alloc_anno_list(struct mptcp_sock * msk,const struct mptcp_addr_info * addr)355 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
356 const struct mptcp_addr_info *addr)
357 {
358 struct mptcp_pm_add_entry *add_entry = NULL;
359 struct sock *sk = (struct sock *)msk;
360 struct net *net = sock_net(sk);
361
362 lockdep_assert_held(&msk->pm.lock);
363
364 add_entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
365
366 if (add_entry) {
367 if (WARN_ON_ONCE(mptcp_pm_is_kernel(msk)))
368 return false;
369
370 sk_reset_timer(sk, &add_entry->add_timer,
371 jiffies + mptcp_get_add_addr_timeout(net));
372 return true;
373 }
374
375 add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
376 if (!add_entry)
377 return false;
378
379 list_add(&add_entry->list, &msk->pm.anno_list);
380
381 add_entry->addr = *addr;
382 add_entry->sock = msk;
383 add_entry->retrans_times = 0;
384
385 timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
386 sk_reset_timer(sk, &add_entry->add_timer,
387 jiffies + mptcp_get_add_addr_timeout(net));
388
389 return true;
390 }
391
mptcp_pm_free_anno_list(struct mptcp_sock * msk)392 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
393 {
394 struct mptcp_pm_add_entry *entry, *tmp;
395 struct sock *sk = (struct sock *)msk;
396 LIST_HEAD(free_list);
397
398 pr_debug("msk=%p\n", msk);
399
400 spin_lock_bh(&msk->pm.lock);
401 list_splice_init(&msk->pm.anno_list, &free_list);
402 spin_unlock_bh(&msk->pm.lock);
403
404 list_for_each_entry_safe(entry, tmp, &free_list, list) {
405 sk_stop_timer_sync(sk, &entry->add_timer);
406 kfree(entry);
407 }
408 }
409
410 /* Fill all the remote addresses into the array addrs[],
411 * and return the array size.
412 */
fill_remote_addresses_vec(struct mptcp_sock * msk,struct mptcp_addr_info * local,bool fullmesh,struct mptcp_addr_info * addrs)413 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk,
414 struct mptcp_addr_info *local,
415 bool fullmesh,
416 struct mptcp_addr_info *addrs)
417 {
418 bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
419 struct sock *sk = (struct sock *)msk, *ssk;
420 struct mptcp_subflow_context *subflow;
421 struct mptcp_addr_info remote = { 0 };
422 unsigned int subflows_max;
423 int i = 0;
424
425 subflows_max = mptcp_pm_get_subflows_max(msk);
426 remote_address((struct sock_common *)sk, &remote);
427
428 /* Non-fullmesh endpoint, fill in the single entry
429 * corresponding to the primary MPC subflow remote address
430 */
431 if (!fullmesh) {
432 if (deny_id0)
433 return 0;
434
435 if (!mptcp_pm_addr_families_match(sk, local, &remote))
436 return 0;
437
438 msk->pm.subflows++;
439 addrs[i++] = remote;
440 } else {
441 DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
442
443 /* Forbid creation of new subflows matching existing
444 * ones, possibly already created by incoming ADD_ADDR
445 */
446 bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
447 mptcp_for_each_subflow(msk, subflow)
448 if (READ_ONCE(subflow->local_id) == local->id)
449 __set_bit(subflow->remote_id, unavail_id);
450
451 mptcp_for_each_subflow(msk, subflow) {
452 ssk = mptcp_subflow_tcp_sock(subflow);
453 remote_address((struct sock_common *)ssk, &addrs[i]);
454 addrs[i].id = READ_ONCE(subflow->remote_id);
455 if (deny_id0 && !addrs[i].id)
456 continue;
457
458 if (test_bit(addrs[i].id, unavail_id))
459 continue;
460
461 if (!mptcp_pm_addr_families_match(sk, local, &addrs[i]))
462 continue;
463
464 if (msk->pm.subflows < subflows_max) {
465 /* forbid creating multiple address towards
466 * this id
467 */
468 __set_bit(addrs[i].id, unavail_id);
469 msk->pm.subflows++;
470 i++;
471 }
472 }
473 }
474
475 return i;
476 }
477
__mptcp_pm_send_ack(struct mptcp_sock * msk,struct mptcp_subflow_context * subflow,bool prio,bool backup)478 static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
479 bool prio, bool backup)
480 {
481 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
482 bool slow;
483
484 pr_debug("send ack for %s\n",
485 prio ? "mp_prio" : (mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr"));
486
487 slow = lock_sock_fast(ssk);
488 if (prio) {
489 subflow->send_mp_prio = 1;
490 subflow->request_bkup = backup;
491 }
492
493 __mptcp_subflow_send_ack(ssk);
494 unlock_sock_fast(ssk, slow);
495 }
496
mptcp_pm_send_ack(struct mptcp_sock * msk,struct mptcp_subflow_context * subflow,bool prio,bool backup)497 static void mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
498 bool prio, bool backup)
499 {
500 spin_unlock_bh(&msk->pm.lock);
501 __mptcp_pm_send_ack(msk, subflow, prio, backup);
502 spin_lock_bh(&msk->pm.lock);
503 }
504
505 static struct mptcp_pm_addr_entry *
__lookup_addr_by_id(struct pm_nl_pernet * pernet,unsigned int id)506 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
507 {
508 struct mptcp_pm_addr_entry *entry;
509
510 list_for_each_entry(entry, &pernet->local_addr_list, list) {
511 if (entry->addr.id == id)
512 return entry;
513 }
514 return NULL;
515 }
516
517 static struct mptcp_pm_addr_entry *
__lookup_addr(struct pm_nl_pernet * pernet,const struct mptcp_addr_info * info,bool lookup_by_id)518 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
519 bool lookup_by_id)
520 {
521 struct mptcp_pm_addr_entry *entry;
522
523 list_for_each_entry(entry, &pernet->local_addr_list, list) {
524 if ((!lookup_by_id &&
525 mptcp_addresses_equal(&entry->addr, info, entry->addr.port)) ||
526 (lookup_by_id && entry->addr.id == info->id))
527 return entry;
528 }
529 return NULL;
530 }
531
mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock * msk)532 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
533 {
534 struct sock *sk = (struct sock *)msk;
535 struct mptcp_pm_addr_entry local;
536 unsigned int add_addr_signal_max;
537 bool signal_and_subflow = false;
538 unsigned int local_addr_max;
539 struct pm_nl_pernet *pernet;
540 unsigned int subflows_max;
541
542 pernet = pm_nl_get_pernet(sock_net(sk));
543
544 add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
545 local_addr_max = mptcp_pm_get_local_addr_max(msk);
546 subflows_max = mptcp_pm_get_subflows_max(msk);
547
548 /* do lazy endpoint usage accounting for the MPC subflows */
549 if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
550 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
551 struct mptcp_pm_addr_entry *entry;
552 struct mptcp_addr_info mpc_addr;
553 bool backup = false;
554
555 mptcp_local_address((struct sock_common *)msk->first, &mpc_addr);
556 rcu_read_lock();
557 entry = __lookup_addr(pernet, &mpc_addr, false);
558 if (entry) {
559 __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap);
560 msk->mpc_endpoint_id = entry->addr.id;
561 backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
562 }
563 rcu_read_unlock();
564
565 if (backup)
566 mptcp_pm_send_ack(msk, subflow, true, backup);
567
568 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
569 }
570
571 pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
572 msk->pm.local_addr_used, local_addr_max,
573 msk->pm.add_addr_signaled, add_addr_signal_max,
574 msk->pm.subflows, subflows_max);
575
576 /* check first for announce */
577 if (msk->pm.add_addr_signaled < add_addr_signal_max) {
578 /* due to racing events on both ends we can reach here while
579 * previous add address is still running: if we invoke now
580 * mptcp_pm_announce_addr(), that will fail and the
581 * corresponding id will be marked as used.
582 * Instead let the PM machinery reschedule us when the
583 * current address announce will be completed.
584 */
585 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
586 return;
587
588 if (!select_signal_address(pernet, msk, &local))
589 goto subflow;
590
591 /* If the alloc fails, we are on memory pressure, not worth
592 * continuing, and trying to create subflows.
593 */
594 if (!mptcp_pm_alloc_anno_list(msk, &local.addr))
595 return;
596
597 __clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
598 msk->pm.add_addr_signaled++;
599
600 /* Special case for ID0: set the correct ID */
601 if (local.addr.id == msk->mpc_endpoint_id)
602 local.addr.id = 0;
603
604 mptcp_pm_announce_addr(msk, &local.addr, false);
605 mptcp_pm_nl_addr_send_ack(msk);
606
607 if (local.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
608 signal_and_subflow = true;
609 }
610
611 subflow:
612 /* check if should create a new subflow */
613 while (msk->pm.local_addr_used < local_addr_max &&
614 msk->pm.subflows < subflows_max) {
615 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
616 bool fullmesh;
617 int i, nr;
618
619 if (signal_and_subflow)
620 signal_and_subflow = false;
621 else if (!select_local_address(pernet, msk, &local))
622 break;
623
624 fullmesh = !!(local.flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
625
626 __clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
627
628 /* Special case for ID0: set the correct ID */
629 if (local.addr.id == msk->mpc_endpoint_id)
630 local.addr.id = 0;
631 else /* local_addr_used is not decr for ID 0 */
632 msk->pm.local_addr_used++;
633
634 nr = fill_remote_addresses_vec(msk, &local.addr, fullmesh, addrs);
635 if (nr == 0)
636 continue;
637
638 spin_unlock_bh(&msk->pm.lock);
639 for (i = 0; i < nr; i++)
640 __mptcp_subflow_connect(sk, &local.addr, &addrs[i]);
641 spin_lock_bh(&msk->pm.lock);
642 }
643 mptcp_pm_nl_check_work_pending(msk);
644 }
645
mptcp_pm_nl_fully_established(struct mptcp_sock * msk)646 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
647 {
648 mptcp_pm_create_subflow_or_signal_addr(msk);
649 }
650
mptcp_pm_nl_subflow_established(struct mptcp_sock * msk)651 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
652 {
653 mptcp_pm_create_subflow_or_signal_addr(msk);
654 }
655
656 /* Fill all the local addresses into the array addrs[],
657 * and return the array size.
658 */
fill_local_addresses_vec(struct mptcp_sock * msk,struct mptcp_addr_info * remote,struct mptcp_addr_info * addrs)659 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
660 struct mptcp_addr_info *remote,
661 struct mptcp_addr_info *addrs)
662 {
663 struct sock *sk = (struct sock *)msk;
664 struct mptcp_pm_addr_entry *entry;
665 struct mptcp_addr_info mpc_addr;
666 struct pm_nl_pernet *pernet;
667 unsigned int subflows_max;
668 int i = 0;
669
670 pernet = pm_nl_get_pernet_from_msk(msk);
671 subflows_max = mptcp_pm_get_subflows_max(msk);
672
673 mptcp_local_address((struct sock_common *)msk, &mpc_addr);
674
675 rcu_read_lock();
676 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
677 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
678 continue;
679
680 if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote))
681 continue;
682
683 if (msk->pm.subflows < subflows_max) {
684 msk->pm.subflows++;
685 addrs[i] = entry->addr;
686
687 /* Special case for ID0: set the correct ID */
688 if (mptcp_addresses_equal(&entry->addr, &mpc_addr, entry->addr.port))
689 addrs[i].id = 0;
690
691 i++;
692 }
693 }
694 rcu_read_unlock();
695
696 /* If the array is empty, fill in the single
697 * 'IPADDRANY' local address
698 */
699 if (!i) {
700 struct mptcp_addr_info local;
701
702 memset(&local, 0, sizeof(local));
703 local.family =
704 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
705 remote->family == AF_INET6 &&
706 ipv6_addr_v4mapped(&remote->addr6) ? AF_INET :
707 #endif
708 remote->family;
709
710 if (!mptcp_pm_addr_families_match(sk, &local, remote))
711 return 0;
712
713 msk->pm.subflows++;
714 addrs[i++] = local;
715 }
716
717 return i;
718 }
719
mptcp_pm_nl_add_addr_received(struct mptcp_sock * msk)720 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
721 {
722 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
723 struct sock *sk = (struct sock *)msk;
724 unsigned int add_addr_accept_max;
725 struct mptcp_addr_info remote;
726 unsigned int subflows_max;
727 bool sf_created = false;
728 int i, nr;
729
730 add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
731 subflows_max = mptcp_pm_get_subflows_max(msk);
732
733 pr_debug("accepted %d:%d remote family %d\n",
734 msk->pm.add_addr_accepted, add_addr_accept_max,
735 msk->pm.remote.family);
736
737 remote = msk->pm.remote;
738 mptcp_pm_announce_addr(msk, &remote, true);
739 mptcp_pm_nl_addr_send_ack(msk);
740
741 if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
742 return;
743
744 /* pick id 0 port, if none is provided the remote address */
745 if (!remote.port)
746 remote.port = sk->sk_dport;
747
748 /* connect to the specified remote address, using whatever
749 * local address the routing configuration will pick.
750 */
751 nr = fill_local_addresses_vec(msk, &remote, addrs);
752 if (nr == 0)
753 return;
754
755 spin_unlock_bh(&msk->pm.lock);
756 for (i = 0; i < nr; i++)
757 if (__mptcp_subflow_connect(sk, &addrs[i], &remote) == 0)
758 sf_created = true;
759 spin_lock_bh(&msk->pm.lock);
760
761 if (sf_created) {
762 /* add_addr_accepted is not decr for ID 0 */
763 if (remote.id)
764 msk->pm.add_addr_accepted++;
765 if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
766 msk->pm.subflows >= subflows_max)
767 WRITE_ONCE(msk->pm.accept_addr, false);
768 }
769 }
770
mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock * msk,const struct mptcp_addr_info * remote)771 bool mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock *msk,
772 const struct mptcp_addr_info *remote)
773 {
774 struct mptcp_addr_info mpc_remote;
775
776 remote_address((struct sock_common *)msk, &mpc_remote);
777 return mptcp_addresses_equal(&mpc_remote, remote, remote->port);
778 }
779
mptcp_pm_nl_addr_send_ack(struct mptcp_sock * msk)780 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
781 {
782 struct mptcp_subflow_context *subflow;
783
784 msk_owned_by_me(msk);
785 lockdep_assert_held(&msk->pm.lock);
786
787 if (!mptcp_pm_should_add_signal(msk) &&
788 !mptcp_pm_should_rm_signal(msk))
789 return;
790
791 mptcp_for_each_subflow(msk, subflow) {
792 if (__mptcp_subflow_active(subflow)) {
793 mptcp_pm_send_ack(msk, subflow, false, false);
794 break;
795 }
796 }
797 }
798
mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock * msk,struct mptcp_addr_info * addr,struct mptcp_addr_info * rem,u8 bkup)799 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
800 struct mptcp_addr_info *addr,
801 struct mptcp_addr_info *rem,
802 u8 bkup)
803 {
804 struct mptcp_subflow_context *subflow;
805
806 pr_debug("bkup=%d\n", bkup);
807
808 mptcp_for_each_subflow(msk, subflow) {
809 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
810 struct mptcp_addr_info local, remote;
811
812 mptcp_local_address((struct sock_common *)ssk, &local);
813 if (!mptcp_addresses_equal(&local, addr, addr->port))
814 continue;
815
816 if (rem && rem->family != AF_UNSPEC) {
817 remote_address((struct sock_common *)ssk, &remote);
818 if (!mptcp_addresses_equal(&remote, rem, rem->port))
819 continue;
820 }
821
822 __mptcp_pm_send_ack(msk, subflow, true, bkup);
823 return 0;
824 }
825
826 return -EINVAL;
827 }
828
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)829 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
830 const struct mptcp_rm_list *rm_list,
831 enum linux_mptcp_mib_field rm_type)
832 {
833 struct mptcp_subflow_context *subflow, *tmp;
834 struct sock *sk = (struct sock *)msk;
835 u8 i;
836
837 pr_debug("%s rm_list_nr %d\n",
838 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
839
840 msk_owned_by_me(msk);
841
842 if (sk->sk_state == TCP_LISTEN)
843 return;
844
845 if (!rm_list->nr)
846 return;
847
848 if (list_empty(&msk->conn_list))
849 return;
850
851 for (i = 0; i < rm_list->nr; i++) {
852 u8 rm_id = rm_list->ids[i];
853 bool removed = false;
854
855 mptcp_for_each_subflow_safe(msk, subflow, tmp) {
856 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
857 u8 remote_id = READ_ONCE(subflow->remote_id);
858 int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
859 u8 id = subflow_get_local_id(subflow);
860
861 if (inet_sk_state_load(ssk) == TCP_CLOSE)
862 continue;
863 if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
864 continue;
865 if (rm_type == MPTCP_MIB_RMSUBFLOW && id != rm_id)
866 continue;
867
868 pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u\n",
869 rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
870 i, rm_id, id, remote_id, msk->mpc_endpoint_id);
871 spin_unlock_bh(&msk->pm.lock);
872 mptcp_subflow_shutdown(sk, ssk, how);
873
874 /* the following takes care of updating the subflows counter */
875 mptcp_close_ssk(sk, ssk, subflow);
876 spin_lock_bh(&msk->pm.lock);
877
878 removed |= subflow->request_join;
879 if (rm_type == MPTCP_MIB_RMSUBFLOW)
880 __MPTCP_INC_STATS(sock_net(sk), rm_type);
881 }
882
883 if (rm_type == MPTCP_MIB_RMADDR)
884 __MPTCP_INC_STATS(sock_net(sk), rm_type);
885
886 if (!removed)
887 continue;
888
889 if (!mptcp_pm_is_kernel(msk))
890 continue;
891
892 if (rm_type == MPTCP_MIB_RMADDR && rm_id &&
893 !WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)) {
894 /* Note: if the subflow has been closed before, this
895 * add_addr_accepted counter will not be decremented.
896 */
897 if (--msk->pm.add_addr_accepted < mptcp_pm_get_add_addr_accept_max(msk))
898 WRITE_ONCE(msk->pm.accept_addr, true);
899 }
900 }
901 }
902
mptcp_pm_nl_rm_addr_received(struct mptcp_sock * msk)903 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
904 {
905 mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
906 }
907
mptcp_pm_nl_rm_subflow_received(struct mptcp_sock * msk,const struct mptcp_rm_list * rm_list)908 static void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
909 const struct mptcp_rm_list *rm_list)
910 {
911 mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
912 }
913
mptcp_pm_nl_work(struct mptcp_sock * msk)914 void mptcp_pm_nl_work(struct mptcp_sock *msk)
915 {
916 struct mptcp_pm_data *pm = &msk->pm;
917
918 msk_owned_by_me(msk);
919
920 if (!(pm->status & MPTCP_PM_WORK_MASK))
921 return;
922
923 spin_lock_bh(&msk->pm.lock);
924
925 pr_debug("msk=%p status=%x\n", msk, pm->status);
926 if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
927 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
928 mptcp_pm_nl_add_addr_received(msk);
929 }
930 if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
931 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
932 mptcp_pm_nl_addr_send_ack(msk);
933 }
934 if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
935 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
936 mptcp_pm_nl_rm_addr_received(msk);
937 }
938 if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
939 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
940 mptcp_pm_nl_fully_established(msk);
941 }
942 if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
943 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
944 mptcp_pm_nl_subflow_established(msk);
945 }
946
947 spin_unlock_bh(&msk->pm.lock);
948 }
949
address_use_port(struct mptcp_pm_addr_entry * entry)950 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
951 {
952 return (entry->flags &
953 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
954 MPTCP_PM_ADDR_FLAG_SIGNAL;
955 }
956
957 /* caller must ensure the RCU grace period is already elapsed */
__mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry * entry)958 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
959 {
960 if (entry->lsk)
961 sock_release(entry->lsk);
962 kfree(entry);
963 }
964
mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet * pernet,struct mptcp_pm_addr_entry * entry,bool needs_id)965 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
966 struct mptcp_pm_addr_entry *entry,
967 bool needs_id)
968 {
969 struct mptcp_pm_addr_entry *cur, *del_entry = NULL;
970 unsigned int addr_max;
971 int ret = -EINVAL;
972
973 spin_lock_bh(&pernet->lock);
974 /* to keep the code simple, don't do IDR-like allocation for address ID,
975 * just bail when we exceed limits
976 */
977 if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
978 pernet->next_id = 1;
979 if (pernet->addrs >= MPTCP_PM_ADDR_MAX) {
980 ret = -ERANGE;
981 goto out;
982 }
983 if (test_bit(entry->addr.id, pernet->id_bitmap)) {
984 ret = -EBUSY;
985 goto out;
986 }
987
988 /* do not insert duplicate address, differentiate on port only
989 * singled addresses
990 */
991 if (!address_use_port(entry))
992 entry->addr.port = 0;
993 list_for_each_entry(cur, &pernet->local_addr_list, list) {
994 if (mptcp_addresses_equal(&cur->addr, &entry->addr,
995 cur->addr.port || entry->addr.port)) {
996 /* allow replacing the exiting endpoint only if such
997 * endpoint is an implicit one and the user-space
998 * did not provide an endpoint id
999 */
1000 if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) {
1001 ret = -EEXIST;
1002 goto out;
1003 }
1004 if (entry->addr.id)
1005 goto out;
1006
1007 pernet->addrs--;
1008 entry->addr.id = cur->addr.id;
1009 list_del_rcu(&cur->list);
1010 del_entry = cur;
1011 break;
1012 }
1013 }
1014
1015 if (!entry->addr.id && needs_id) {
1016 find_next:
1017 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
1018 MPTCP_PM_MAX_ADDR_ID + 1,
1019 pernet->next_id);
1020 if (!entry->addr.id && pernet->next_id != 1) {
1021 pernet->next_id = 1;
1022 goto find_next;
1023 }
1024 }
1025
1026 if (!entry->addr.id && needs_id)
1027 goto out;
1028
1029 __set_bit(entry->addr.id, pernet->id_bitmap);
1030 if (entry->addr.id > pernet->next_id)
1031 pernet->next_id = entry->addr.id;
1032
1033 if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1034 addr_max = pernet->add_addr_signal_max;
1035 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
1036 }
1037 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1038 addr_max = pernet->local_addr_max;
1039 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
1040 }
1041
1042 pernet->addrs++;
1043 if (!entry->addr.port)
1044 list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
1045 else
1046 list_add_rcu(&entry->list, &pernet->local_addr_list);
1047 ret = entry->addr.id;
1048
1049 out:
1050 spin_unlock_bh(&pernet->lock);
1051
1052 /* just replaced an existing entry, free it */
1053 if (del_entry) {
1054 synchronize_rcu();
1055 __mptcp_pm_release_addr_entry(del_entry);
1056 }
1057 return ret;
1058 }
1059
1060 static struct lock_class_key mptcp_slock_keys[2];
1061 static struct lock_class_key mptcp_keys[2];
1062
mptcp_pm_nl_create_listen_socket(struct sock * sk,struct mptcp_pm_addr_entry * entry)1063 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
1064 struct mptcp_pm_addr_entry *entry)
1065 {
1066 bool is_ipv6 = sk->sk_family == AF_INET6;
1067 int addrlen = sizeof(struct sockaddr_in);
1068 struct sockaddr_storage addr;
1069 struct sock *newsk, *ssk;
1070 int backlog = 1024;
1071 int err;
1072
1073 err = sock_create_kern(sock_net(sk), entry->addr.family,
1074 SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
1075 if (err)
1076 return err;
1077
1078 newsk = entry->lsk->sk;
1079 if (!newsk)
1080 return -EINVAL;
1081
1082 /* The subflow socket lock is acquired in a nested to the msk one
1083 * in several places, even by the TCP stack, and this msk is a kernel
1084 * socket: lockdep complains. Instead of propagating the _nested
1085 * modifiers in several places, re-init the lock class for the msk
1086 * socket to an mptcp specific one.
1087 */
1088 sock_lock_init_class_and_name(newsk,
1089 is_ipv6 ? "mlock-AF_INET6" : "mlock-AF_INET",
1090 &mptcp_slock_keys[is_ipv6],
1091 is_ipv6 ? "msk_lock-AF_INET6" : "msk_lock-AF_INET",
1092 &mptcp_keys[is_ipv6]);
1093
1094 lock_sock(newsk);
1095 ssk = __mptcp_nmpc_sk(mptcp_sk(newsk));
1096 release_sock(newsk);
1097 if (IS_ERR(ssk))
1098 return PTR_ERR(ssk);
1099
1100 mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
1101 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1102 if (entry->addr.family == AF_INET6)
1103 addrlen = sizeof(struct sockaddr_in6);
1104 #endif
1105 if (ssk->sk_family == AF_INET)
1106 err = inet_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1107 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1108 else if (ssk->sk_family == AF_INET6)
1109 err = inet6_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1110 #endif
1111 if (err)
1112 return err;
1113
1114 /* We don't use mptcp_set_state() here because it needs to be called
1115 * under the msk socket lock. For the moment, that will not bring
1116 * anything more than only calling inet_sk_state_store(), because the
1117 * old status is known (TCP_CLOSE).
1118 */
1119 inet_sk_state_store(newsk, TCP_LISTEN);
1120 lock_sock(ssk);
1121 err = __inet_listen_sk(ssk, backlog);
1122 if (!err)
1123 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED);
1124 release_sock(ssk);
1125 return err;
1126 }
1127
mptcp_pm_nl_get_local_id(struct mptcp_sock * msk,struct mptcp_addr_info * skc)1128 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1129 {
1130 struct mptcp_pm_addr_entry *entry;
1131 struct pm_nl_pernet *pernet;
1132 int ret = -1;
1133
1134 pernet = pm_nl_get_pernet_from_msk(msk);
1135
1136 rcu_read_lock();
1137 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1138 if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
1139 ret = entry->addr.id;
1140 break;
1141 }
1142 }
1143 rcu_read_unlock();
1144 if (ret >= 0)
1145 return ret;
1146
1147 /* address not found, add to local list */
1148 entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1149 if (!entry)
1150 return -ENOMEM;
1151
1152 entry->addr = *skc;
1153 entry->addr.id = 0;
1154 entry->addr.port = 0;
1155 entry->ifindex = 0;
1156 entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
1157 entry->lsk = NULL;
1158 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
1159 if (ret < 0)
1160 kfree(entry);
1161
1162 return ret;
1163 }
1164
mptcp_pm_nl_is_backup(struct mptcp_sock * msk,struct mptcp_addr_info * skc)1165 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1166 {
1167 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
1168 struct mptcp_pm_addr_entry *entry;
1169 bool backup = false;
1170
1171 rcu_read_lock();
1172 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1173 if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
1174 backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
1175 break;
1176 }
1177 }
1178 rcu_read_unlock();
1179
1180 return backup;
1181 }
1182
1183 #define MPTCP_PM_CMD_GRP_OFFSET 0
1184 #define MPTCP_PM_EV_GRP_OFFSET 1
1185
1186 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1187 [MPTCP_PM_CMD_GRP_OFFSET] = { .name = MPTCP_PM_CMD_GRP_NAME, },
1188 [MPTCP_PM_EV_GRP_OFFSET] = { .name = MPTCP_PM_EV_GRP_NAME,
1189 .flags = GENL_UNS_ADMIN_PERM,
1190 },
1191 };
1192
1193 static const struct nla_policy
1194 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
1195 [MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, },
1196 [MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, },
1197 [MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, },
1198 [MPTCP_PM_ADDR_ATTR_ADDR6] =
1199 NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
1200 [MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16 },
1201 [MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32 },
1202 [MPTCP_PM_ADDR_ATTR_IF_IDX] = { .type = NLA_S32 },
1203 };
1204
1205 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
1206 [MPTCP_PM_ATTR_ADDR] =
1207 NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1208 [MPTCP_PM_ATTR_RCV_ADD_ADDRS] = { .type = NLA_U32, },
1209 [MPTCP_PM_ATTR_SUBFLOWS] = { .type = NLA_U32, },
1210 [MPTCP_PM_ATTR_TOKEN] = { .type = NLA_U32, },
1211 [MPTCP_PM_ATTR_LOC_ID] = { .type = NLA_U8, },
1212 [MPTCP_PM_ATTR_ADDR_REMOTE] =
1213 NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1214 };
1215
mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock * msk,struct sock * ssk)1216 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1217 {
1218 struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1219 struct sock *sk = (struct sock *)msk;
1220 unsigned int active_max_loss_cnt;
1221 struct net *net = sock_net(sk);
1222 unsigned int stale_loss_cnt;
1223 bool slow;
1224
1225 stale_loss_cnt = mptcp_stale_loss_cnt(net);
1226 if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1227 return;
1228
1229 /* look for another available subflow not in loss state */
1230 active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1231 mptcp_for_each_subflow(msk, iter) {
1232 if (iter != subflow && mptcp_subflow_active(iter) &&
1233 iter->stale_count < active_max_loss_cnt) {
1234 /* we have some alternatives, try to mark this subflow as idle ...*/
1235 slow = lock_sock_fast(ssk);
1236 if (!tcp_rtx_and_write_queues_empty(ssk)) {
1237 subflow->stale = 1;
1238 __mptcp_retransmit_pending_data(sk);
1239 MPTCP_INC_STATS(net, MPTCP_MIB_SUBFLOWSTALE);
1240 }
1241 unlock_sock_fast(ssk, slow);
1242
1243 /* always try to push the pending data regardless of re-injections:
1244 * we can possibly use backup subflows now, and subflow selection
1245 * is cheap under the msk socket lock
1246 */
1247 __mptcp_push_pending(sk, 0);
1248 return;
1249 }
1250 }
1251 }
1252
mptcp_pm_family_to_addr(int family)1253 static int mptcp_pm_family_to_addr(int family)
1254 {
1255 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1256 if (family == AF_INET6)
1257 return MPTCP_PM_ADDR_ATTR_ADDR6;
1258 #endif
1259 return MPTCP_PM_ADDR_ATTR_ADDR4;
1260 }
1261
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)1262 static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
1263 const struct nlattr *attr,
1264 struct genl_info *info,
1265 struct mptcp_addr_info *addr,
1266 bool require_family)
1267 {
1268 int err, addr_addr;
1269
1270 if (!attr) {
1271 GENL_SET_ERR_MSG(info, "missing address info");
1272 return -EINVAL;
1273 }
1274
1275 /* no validation needed - was already done via nested policy */
1276 err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1277 mptcp_pm_addr_policy, info->extack);
1278 if (err)
1279 return err;
1280
1281 if (tb[MPTCP_PM_ADDR_ATTR_ID])
1282 addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1283
1284 if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1285 if (!require_family)
1286 return 0;
1287
1288 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1289 "missing family");
1290 return -EINVAL;
1291 }
1292
1293 addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1294 if (addr->family != AF_INET
1295 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1296 && addr->family != AF_INET6
1297 #endif
1298 ) {
1299 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1300 "unknown address family");
1301 return -EINVAL;
1302 }
1303 addr_addr = mptcp_pm_family_to_addr(addr->family);
1304 if (!tb[addr_addr]) {
1305 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1306 "missing address data");
1307 return -EINVAL;
1308 }
1309
1310 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1311 if (addr->family == AF_INET6)
1312 addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
1313 else
1314 #endif
1315 addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1316
1317 if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1318 addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1319
1320 return 0;
1321 }
1322
mptcp_pm_parse_addr(struct nlattr * attr,struct genl_info * info,struct mptcp_addr_info * addr)1323 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1324 struct mptcp_addr_info *addr)
1325 {
1326 struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1327
1328 memset(addr, 0, sizeof(*addr));
1329
1330 return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
1331 }
1332
mptcp_pm_parse_entry(struct nlattr * attr,struct genl_info * info,bool require_family,struct mptcp_pm_addr_entry * entry)1333 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1334 bool require_family,
1335 struct mptcp_pm_addr_entry *entry)
1336 {
1337 struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1338 int err;
1339
1340 memset(entry, 0, sizeof(*entry));
1341
1342 err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
1343 if (err)
1344 return err;
1345
1346 if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1347 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1348
1349 entry->ifindex = val;
1350 }
1351
1352 if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1353 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1354
1355 if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1356 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1357
1358 return 0;
1359 }
1360
genl_info_pm_nl(struct genl_info * info)1361 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1362 {
1363 return pm_nl_get_pernet(genl_info_net(info));
1364 }
1365
mptcp_nl_add_subflow_or_signal_addr(struct net * net,struct mptcp_addr_info * addr)1366 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net,
1367 struct mptcp_addr_info *addr)
1368 {
1369 struct mptcp_sock *msk;
1370 long s_slot = 0, s_num = 0;
1371
1372 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1373 struct sock *sk = (struct sock *)msk;
1374 struct mptcp_addr_info mpc_addr;
1375
1376 if (!READ_ONCE(msk->fully_established) ||
1377 mptcp_pm_is_userspace(msk))
1378 goto next;
1379
1380 /* if the endp linked to the init sf is re-added with a != ID */
1381 mptcp_local_address((struct sock_common *)msk, &mpc_addr);
1382
1383 lock_sock(sk);
1384 spin_lock_bh(&msk->pm.lock);
1385 if (mptcp_addresses_equal(addr, &mpc_addr, addr->port))
1386 msk->mpc_endpoint_id = addr->id;
1387 mptcp_pm_create_subflow_or_signal_addr(msk);
1388 spin_unlock_bh(&msk->pm.lock);
1389 release_sock(sk);
1390
1391 next:
1392 sock_put(sk);
1393 cond_resched();
1394 }
1395
1396 return 0;
1397 }
1398
mptcp_pm_has_addr_attr_id(const struct nlattr * attr,struct genl_info * info)1399 static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr,
1400 struct genl_info *info)
1401 {
1402 struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1403
1404 if (!nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1405 mptcp_pm_addr_policy, info->extack) &&
1406 tb[MPTCP_PM_ADDR_ATTR_ID])
1407 return true;
1408 return false;
1409 }
1410
mptcp_nl_cmd_add_addr(struct sk_buff * skb,struct genl_info * info)1411 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1412 {
1413 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1414 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1415 struct mptcp_pm_addr_entry addr, *entry;
1416 int ret;
1417
1418 ret = mptcp_pm_parse_entry(attr, info, true, &addr);
1419 if (ret < 0)
1420 return ret;
1421
1422 if (addr.addr.port && !address_use_port(&addr)) {
1423 GENL_SET_ERR_MSG(info, "flags must have signal and not subflow when using port");
1424 return -EINVAL;
1425 }
1426
1427 if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
1428 addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
1429 GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
1430 return -EINVAL;
1431 }
1432
1433 if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
1434 GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
1435 return -EINVAL;
1436 }
1437
1438 entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
1439 if (!entry) {
1440 GENL_SET_ERR_MSG(info, "can't allocate addr");
1441 return -ENOMEM;
1442 }
1443
1444 *entry = addr;
1445 if (entry->addr.port) {
1446 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1447 if (ret) {
1448 GENL_SET_ERR_MSG_FMT(info, "create listen socket error: %d", ret);
1449 goto out_free;
1450 }
1451 }
1452 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry,
1453 !mptcp_pm_has_addr_attr_id(attr, info));
1454 if (ret < 0) {
1455 GENL_SET_ERR_MSG_FMT(info, "too many addresses or duplicate one: %d", ret);
1456 goto out_free;
1457 }
1458
1459 mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk), &entry->addr);
1460 return 0;
1461
1462 out_free:
1463 __mptcp_pm_release_addr_entry(entry);
1464 return ret;
1465 }
1466
mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock * msk,unsigned int id,u8 * flags,int * ifindex)1467 int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
1468 u8 *flags, int *ifindex)
1469 {
1470 struct mptcp_pm_addr_entry *entry;
1471 struct sock *sk = (struct sock *)msk;
1472 struct net *net = sock_net(sk);
1473
1474 /* No entries with ID 0 */
1475 if (id == 0)
1476 return 0;
1477
1478 rcu_read_lock();
1479 entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
1480 if (entry) {
1481 *flags = entry->flags;
1482 *ifindex = entry->ifindex;
1483 }
1484 rcu_read_unlock();
1485
1486 return 0;
1487 }
1488
remove_anno_list_by_saddr(struct mptcp_sock * msk,const struct mptcp_addr_info * addr)1489 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1490 const struct mptcp_addr_info *addr)
1491 {
1492 struct mptcp_pm_add_entry *entry;
1493
1494 entry = mptcp_pm_del_add_timer(msk, addr, false);
1495 if (entry) {
1496 list_del(&entry->list);
1497 kfree(entry);
1498 return true;
1499 }
1500
1501 return false;
1502 }
1503
mptcp_endp_get_local_id(struct mptcp_sock * msk,const struct mptcp_addr_info * addr)1504 static u8 mptcp_endp_get_local_id(struct mptcp_sock *msk,
1505 const struct mptcp_addr_info *addr)
1506 {
1507 return msk->mpc_endpoint_id == addr->id ? 0 : addr->id;
1508 }
1509
mptcp_pm_remove_anno_addr(struct mptcp_sock * msk,const struct mptcp_addr_info * addr,bool force)1510 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1511 const struct mptcp_addr_info *addr,
1512 bool force)
1513 {
1514 struct mptcp_rm_list list = { .nr = 0 };
1515 bool ret;
1516
1517 list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr);
1518
1519 ret = remove_anno_list_by_saddr(msk, addr);
1520 if (ret || force) {
1521 spin_lock_bh(&msk->pm.lock);
1522 if (ret) {
1523 __set_bit(addr->id, msk->pm.id_avail_bitmap);
1524 msk->pm.add_addr_signaled--;
1525 }
1526 mptcp_pm_remove_addr(msk, &list);
1527 spin_unlock_bh(&msk->pm.lock);
1528 }
1529 return ret;
1530 }
1531
__mark_subflow_endp_available(struct mptcp_sock * msk,u8 id)1532 static void __mark_subflow_endp_available(struct mptcp_sock *msk, u8 id)
1533 {
1534 /* If it was marked as used, and not ID 0, decrement local_addr_used */
1535 if (!__test_and_set_bit(id ? : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap) &&
1536 id && !WARN_ON_ONCE(msk->pm.local_addr_used == 0))
1537 msk->pm.local_addr_used--;
1538 }
1539
mptcp_nl_remove_subflow_and_signal_addr(struct net * net,const struct mptcp_pm_addr_entry * entry)1540 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1541 const struct mptcp_pm_addr_entry *entry)
1542 {
1543 const struct mptcp_addr_info *addr = &entry->addr;
1544 struct mptcp_rm_list list = { .nr = 1 };
1545 long s_slot = 0, s_num = 0;
1546 struct mptcp_sock *msk;
1547
1548 pr_debug("remove_id=%d\n", addr->id);
1549
1550 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1551 struct sock *sk = (struct sock *)msk;
1552 bool remove_subflow;
1553
1554 if (mptcp_pm_is_userspace(msk))
1555 goto next;
1556
1557 if (list_empty(&msk->conn_list)) {
1558 mptcp_pm_remove_anno_addr(msk, addr, false);
1559 goto next;
1560 }
1561
1562 lock_sock(sk);
1563 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1564 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
1565 !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
1566
1567 list.ids[0] = mptcp_endp_get_local_id(msk, addr);
1568 if (remove_subflow) {
1569 spin_lock_bh(&msk->pm.lock);
1570 mptcp_pm_nl_rm_subflow_received(msk, &list);
1571 spin_unlock_bh(&msk->pm.lock);
1572 }
1573
1574 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1575 spin_lock_bh(&msk->pm.lock);
1576 __mark_subflow_endp_available(msk, list.ids[0]);
1577 spin_unlock_bh(&msk->pm.lock);
1578 }
1579
1580 if (msk->mpc_endpoint_id == entry->addr.id)
1581 msk->mpc_endpoint_id = 0;
1582 release_sock(sk);
1583
1584 next:
1585 sock_put(sk);
1586 cond_resched();
1587 }
1588
1589 return 0;
1590 }
1591
mptcp_nl_remove_id_zero_address(struct net * net,struct mptcp_addr_info * addr)1592 static int mptcp_nl_remove_id_zero_address(struct net *net,
1593 struct mptcp_addr_info *addr)
1594 {
1595 struct mptcp_rm_list list = { .nr = 0 };
1596 long s_slot = 0, s_num = 0;
1597 struct mptcp_sock *msk;
1598
1599 list.ids[list.nr++] = 0;
1600
1601 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1602 struct sock *sk = (struct sock *)msk;
1603 struct mptcp_addr_info msk_local;
1604
1605 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1606 goto next;
1607
1608 mptcp_local_address((struct sock_common *)msk, &msk_local);
1609 if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
1610 goto next;
1611
1612 lock_sock(sk);
1613 spin_lock_bh(&msk->pm.lock);
1614 mptcp_pm_remove_addr(msk, &list);
1615 mptcp_pm_nl_rm_subflow_received(msk, &list);
1616 __mark_subflow_endp_available(msk, 0);
1617 spin_unlock_bh(&msk->pm.lock);
1618 release_sock(sk);
1619
1620 next:
1621 sock_put(sk);
1622 cond_resched();
1623 }
1624
1625 return 0;
1626 }
1627
mptcp_nl_cmd_del_addr(struct sk_buff * skb,struct genl_info * info)1628 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1629 {
1630 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1631 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1632 struct mptcp_pm_addr_entry addr, *entry;
1633 unsigned int addr_max;
1634 int ret;
1635
1636 ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1637 if (ret < 0)
1638 return ret;
1639
1640 /* the zero id address is special: the first address used by the msk
1641 * always gets such an id, so different subflows can have different zero
1642 * id addresses. Additionally zero id is not accounted for in id_bitmap.
1643 * Let's use an 'mptcp_rm_list' instead of the common remove code.
1644 */
1645 if (addr.addr.id == 0)
1646 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1647
1648 spin_lock_bh(&pernet->lock);
1649 entry = __lookup_addr_by_id(pernet, addr.addr.id);
1650 if (!entry) {
1651 GENL_SET_ERR_MSG(info, "address not found");
1652 spin_unlock_bh(&pernet->lock);
1653 return -EINVAL;
1654 }
1655 if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1656 addr_max = pernet->add_addr_signal_max;
1657 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1658 }
1659 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1660 addr_max = pernet->local_addr_max;
1661 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1662 }
1663
1664 pernet->addrs--;
1665 list_del_rcu(&entry->list);
1666 __clear_bit(entry->addr.id, pernet->id_bitmap);
1667 spin_unlock_bh(&pernet->lock);
1668
1669 mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry);
1670 synchronize_rcu();
1671 __mptcp_pm_release_addr_entry(entry);
1672
1673 return ret;
1674 }
1675
1676 /* Called from the userspace PM only */
mptcp_pm_remove_addrs(struct mptcp_sock * msk,struct list_head * rm_list)1677 void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
1678 {
1679 struct mptcp_rm_list alist = { .nr = 0 };
1680 struct mptcp_pm_addr_entry *entry;
1681 int anno_nr = 0;
1682
1683 list_for_each_entry(entry, rm_list, list) {
1684 if (alist.nr >= MPTCP_RM_IDS_MAX)
1685 break;
1686
1687 /* only delete if either announced or matching a subflow */
1688 if (remove_anno_list_by_saddr(msk, &entry->addr))
1689 anno_nr++;
1690 else if (!lookup_subflow_by_saddr(&msk->conn_list,
1691 &entry->addr))
1692 continue;
1693
1694 alist.ids[alist.nr++] = entry->addr.id;
1695 }
1696
1697 if (alist.nr) {
1698 spin_lock_bh(&msk->pm.lock);
1699 msk->pm.add_addr_signaled -= anno_nr;
1700 mptcp_pm_remove_addr(msk, &alist);
1701 spin_unlock_bh(&msk->pm.lock);
1702 }
1703 }
1704
1705 /* Called from the in-kernel PM only */
mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock * msk,struct list_head * rm_list)1706 static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1707 struct list_head *rm_list)
1708 {
1709 struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1710 struct mptcp_pm_addr_entry *entry;
1711
1712 list_for_each_entry(entry, rm_list, list) {
1713 if (slist.nr < MPTCP_RM_IDS_MAX &&
1714 lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
1715 slist.ids[slist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
1716
1717 if (alist.nr < MPTCP_RM_IDS_MAX &&
1718 remove_anno_list_by_saddr(msk, &entry->addr))
1719 alist.ids[alist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
1720 }
1721
1722 spin_lock_bh(&msk->pm.lock);
1723 if (alist.nr) {
1724 msk->pm.add_addr_signaled -= alist.nr;
1725 mptcp_pm_remove_addr(msk, &alist);
1726 }
1727 if (slist.nr)
1728 mptcp_pm_nl_rm_subflow_received(msk, &slist);
1729 /* Reset counters: maybe some subflows have been removed before */
1730 bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1731 msk->pm.local_addr_used = 0;
1732 spin_unlock_bh(&msk->pm.lock);
1733 }
1734
mptcp_nl_remove_addrs_list(struct net * net,struct list_head * rm_list)1735 static void mptcp_nl_remove_addrs_list(struct net *net,
1736 struct list_head *rm_list)
1737 {
1738 long s_slot = 0, s_num = 0;
1739 struct mptcp_sock *msk;
1740
1741 if (list_empty(rm_list))
1742 return;
1743
1744 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1745 struct sock *sk = (struct sock *)msk;
1746
1747 if (!mptcp_pm_is_userspace(msk)) {
1748 lock_sock(sk);
1749 mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1750 release_sock(sk);
1751 }
1752
1753 sock_put(sk);
1754 cond_resched();
1755 }
1756 }
1757
1758 /* caller must ensure the RCU grace period is already elapsed */
__flush_addrs(struct list_head * list)1759 static void __flush_addrs(struct list_head *list)
1760 {
1761 while (!list_empty(list)) {
1762 struct mptcp_pm_addr_entry *cur;
1763
1764 cur = list_entry(list->next,
1765 struct mptcp_pm_addr_entry, list);
1766 list_del_rcu(&cur->list);
1767 __mptcp_pm_release_addr_entry(cur);
1768 }
1769 }
1770
__reset_counters(struct pm_nl_pernet * pernet)1771 static void __reset_counters(struct pm_nl_pernet *pernet)
1772 {
1773 WRITE_ONCE(pernet->add_addr_signal_max, 0);
1774 WRITE_ONCE(pernet->add_addr_accept_max, 0);
1775 WRITE_ONCE(pernet->local_addr_max, 0);
1776 pernet->addrs = 0;
1777 }
1778
mptcp_nl_cmd_flush_addrs(struct sk_buff * skb,struct genl_info * info)1779 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1780 {
1781 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1782 LIST_HEAD(free_list);
1783
1784 spin_lock_bh(&pernet->lock);
1785 list_splice_init(&pernet->local_addr_list, &free_list);
1786 __reset_counters(pernet);
1787 pernet->next_id = 1;
1788 bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1789 spin_unlock_bh(&pernet->lock);
1790 mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1791 synchronize_rcu();
1792 __flush_addrs(&free_list);
1793 return 0;
1794 }
1795
mptcp_nl_fill_addr(struct sk_buff * skb,struct mptcp_pm_addr_entry * entry)1796 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1797 struct mptcp_pm_addr_entry *entry)
1798 {
1799 struct mptcp_addr_info *addr = &entry->addr;
1800 struct nlattr *attr;
1801
1802 attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1803 if (!attr)
1804 return -EMSGSIZE;
1805
1806 if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1807 goto nla_put_failure;
1808 if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1809 goto nla_put_failure;
1810 if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1811 goto nla_put_failure;
1812 if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1813 goto nla_put_failure;
1814 if (entry->ifindex &&
1815 nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1816 goto nla_put_failure;
1817
1818 if (addr->family == AF_INET &&
1819 nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1820 addr->addr.s_addr))
1821 goto nla_put_failure;
1822 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1823 else if (addr->family == AF_INET6 &&
1824 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1825 goto nla_put_failure;
1826 #endif
1827 nla_nest_end(skb, attr);
1828 return 0;
1829
1830 nla_put_failure:
1831 nla_nest_cancel(skb, attr);
1832 return -EMSGSIZE;
1833 }
1834
mptcp_nl_cmd_get_addr(struct sk_buff * skb,struct genl_info * info)1835 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1836 {
1837 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1838 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1839 struct mptcp_pm_addr_entry addr, *entry;
1840 struct sk_buff *msg;
1841 void *reply;
1842 int ret;
1843
1844 ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1845 if (ret < 0)
1846 return ret;
1847
1848 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1849 if (!msg)
1850 return -ENOMEM;
1851
1852 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1853 info->genlhdr->cmd);
1854 if (!reply) {
1855 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1856 ret = -EMSGSIZE;
1857 goto fail;
1858 }
1859
1860 spin_lock_bh(&pernet->lock);
1861 entry = __lookup_addr_by_id(pernet, addr.addr.id);
1862 if (!entry) {
1863 GENL_SET_ERR_MSG(info, "address not found");
1864 ret = -EINVAL;
1865 goto unlock_fail;
1866 }
1867
1868 ret = mptcp_nl_fill_addr(msg, entry);
1869 if (ret)
1870 goto unlock_fail;
1871
1872 genlmsg_end(msg, reply);
1873 ret = genlmsg_reply(msg, info);
1874 spin_unlock_bh(&pernet->lock);
1875 return ret;
1876
1877 unlock_fail:
1878 spin_unlock_bh(&pernet->lock);
1879
1880 fail:
1881 nlmsg_free(msg);
1882 return ret;
1883 }
1884
mptcp_nl_cmd_dump_addrs(struct sk_buff * msg,struct netlink_callback * cb)1885 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1886 struct netlink_callback *cb)
1887 {
1888 struct net *net = sock_net(msg->sk);
1889 struct mptcp_pm_addr_entry *entry;
1890 struct pm_nl_pernet *pernet;
1891 int id = cb->args[0];
1892 void *hdr;
1893 int i;
1894
1895 pernet = pm_nl_get_pernet(net);
1896
1897 spin_lock_bh(&pernet->lock);
1898 for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1899 if (test_bit(i, pernet->id_bitmap)) {
1900 entry = __lookup_addr_by_id(pernet, i);
1901 if (!entry)
1902 break;
1903
1904 if (entry->addr.id <= id)
1905 continue;
1906
1907 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1908 cb->nlh->nlmsg_seq, &mptcp_genl_family,
1909 NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1910 if (!hdr)
1911 break;
1912
1913 if (mptcp_nl_fill_addr(msg, entry) < 0) {
1914 genlmsg_cancel(msg, hdr);
1915 break;
1916 }
1917
1918 id = entry->addr.id;
1919 genlmsg_end(msg, hdr);
1920 }
1921 }
1922 spin_unlock_bh(&pernet->lock);
1923
1924 cb->args[0] = id;
1925 return msg->len;
1926 }
1927
parse_limit(struct genl_info * info,int id,unsigned int * limit)1928 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1929 {
1930 struct nlattr *attr = info->attrs[id];
1931
1932 if (!attr)
1933 return 0;
1934
1935 *limit = nla_get_u32(attr);
1936 if (*limit > MPTCP_PM_ADDR_MAX) {
1937 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1938 return -EINVAL;
1939 }
1940 return 0;
1941 }
1942
1943 static int
mptcp_nl_cmd_set_limits(struct sk_buff * skb,struct genl_info * info)1944 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1945 {
1946 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1947 unsigned int rcv_addrs, subflows;
1948 int ret;
1949
1950 spin_lock_bh(&pernet->lock);
1951 rcv_addrs = pernet->add_addr_accept_max;
1952 ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1953 if (ret)
1954 goto unlock;
1955
1956 subflows = pernet->subflows_max;
1957 ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1958 if (ret)
1959 goto unlock;
1960
1961 WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1962 WRITE_ONCE(pernet->subflows_max, subflows);
1963
1964 unlock:
1965 spin_unlock_bh(&pernet->lock);
1966 return ret;
1967 }
1968
1969 static int
mptcp_nl_cmd_get_limits(struct sk_buff * skb,struct genl_info * info)1970 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1971 {
1972 struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1973 struct sk_buff *msg;
1974 void *reply;
1975
1976 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1977 if (!msg)
1978 return -ENOMEM;
1979
1980 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1981 MPTCP_PM_CMD_GET_LIMITS);
1982 if (!reply)
1983 goto fail;
1984
1985 if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1986 READ_ONCE(pernet->add_addr_accept_max)))
1987 goto fail;
1988
1989 if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1990 READ_ONCE(pernet->subflows_max)))
1991 goto fail;
1992
1993 genlmsg_end(msg, reply);
1994 return genlmsg_reply(msg, info);
1995
1996 fail:
1997 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1998 nlmsg_free(msg);
1999 return -EMSGSIZE;
2000 }
2001
mptcp_pm_nl_fullmesh(struct mptcp_sock * msk,struct mptcp_addr_info * addr)2002 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
2003 struct mptcp_addr_info *addr)
2004 {
2005 struct mptcp_rm_list list = { .nr = 0 };
2006
2007 list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr);
2008
2009 spin_lock_bh(&msk->pm.lock);
2010 mptcp_pm_nl_rm_subflow_received(msk, &list);
2011 __mark_subflow_endp_available(msk, list.ids[0]);
2012 mptcp_pm_create_subflow_or_signal_addr(msk);
2013 spin_unlock_bh(&msk->pm.lock);
2014 }
2015
mptcp_nl_set_flags(struct net * net,struct mptcp_addr_info * addr,u8 bkup,u8 changed)2016 static int mptcp_nl_set_flags(struct net *net,
2017 struct mptcp_addr_info *addr,
2018 u8 bkup, u8 changed)
2019 {
2020 long s_slot = 0, s_num = 0;
2021 struct mptcp_sock *msk;
2022 int ret = -EINVAL;
2023
2024 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
2025 struct sock *sk = (struct sock *)msk;
2026
2027 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
2028 goto next;
2029
2030 lock_sock(sk);
2031 if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
2032 ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
2033 if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
2034 mptcp_pm_nl_fullmesh(msk, addr);
2035 release_sock(sk);
2036
2037 next:
2038 sock_put(sk);
2039 cond_resched();
2040 }
2041
2042 return ret;
2043 }
2044
mptcp_pm_nl_set_flags(struct net * net,struct mptcp_pm_addr_entry * addr,u8 bkup)2045 int mptcp_pm_nl_set_flags(struct net *net, struct mptcp_pm_addr_entry *addr, u8 bkup)
2046 {
2047 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2048 u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
2049 MPTCP_PM_ADDR_FLAG_FULLMESH;
2050 struct mptcp_pm_addr_entry *entry;
2051 u8 lookup_by_id = 0;
2052
2053 if (addr->addr.family == AF_UNSPEC) {
2054 lookup_by_id = 1;
2055 if (!addr->addr.id)
2056 return -EOPNOTSUPP;
2057 }
2058
2059 spin_lock_bh(&pernet->lock);
2060 entry = __lookup_addr(pernet, &addr->addr, lookup_by_id);
2061 if (!entry) {
2062 spin_unlock_bh(&pernet->lock);
2063 return -EINVAL;
2064 }
2065 if ((addr->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
2066 (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
2067 spin_unlock_bh(&pernet->lock);
2068 return -EINVAL;
2069 }
2070
2071 changed = (addr->flags ^ entry->flags) & mask;
2072 entry->flags = (entry->flags & ~mask) | (addr->flags & mask);
2073 *addr = *entry;
2074 spin_unlock_bh(&pernet->lock);
2075
2076 mptcp_nl_set_flags(net, &addr->addr, bkup, changed);
2077 return 0;
2078 }
2079
mptcp_nl_cmd_set_flags(struct sk_buff * skb,struct genl_info * info)2080 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
2081 {
2082 struct mptcp_pm_addr_entry remote = { .addr = { .family = AF_UNSPEC }, };
2083 struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
2084 struct nlattr *attr_rem = info->attrs[MPTCP_PM_ATTR_ADDR_REMOTE];
2085 struct nlattr *token = info->attrs[MPTCP_PM_ATTR_TOKEN];
2086 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
2087 struct net *net = sock_net(skb->sk);
2088 u8 bkup = 0;
2089 int ret;
2090
2091 ret = mptcp_pm_parse_entry(attr, info, false, &addr);
2092 if (ret < 0)
2093 return ret;
2094
2095 if (attr_rem) {
2096 ret = mptcp_pm_parse_entry(attr_rem, info, false, &remote);
2097 if (ret < 0)
2098 return ret;
2099 }
2100
2101 if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
2102 bkup = 1;
2103
2104 return mptcp_pm_set_flags(net, token, &addr, &remote, bkup);
2105 }
2106
mptcp_nl_mcast_send(struct net * net,struct sk_buff * nlskb,gfp_t gfp)2107 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
2108 {
2109 genlmsg_multicast_netns(&mptcp_genl_family, net,
2110 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
2111 }
2112
mptcp_userspace_pm_active(const struct mptcp_sock * msk)2113 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)
2114 {
2115 return genl_has_listeners(&mptcp_genl_family,
2116 sock_net((const struct sock *)msk),
2117 MPTCP_PM_EV_GRP_OFFSET);
2118 }
2119
mptcp_event_add_subflow(struct sk_buff * skb,const struct sock * ssk)2120 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
2121 {
2122 const struct inet_sock *issk = inet_sk(ssk);
2123 const struct mptcp_subflow_context *sf;
2124
2125 if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2126 return -EMSGSIZE;
2127
2128 switch (ssk->sk_family) {
2129 case AF_INET:
2130 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2131 return -EMSGSIZE;
2132 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
2133 return -EMSGSIZE;
2134 break;
2135 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2136 case AF_INET6: {
2137 const struct ipv6_pinfo *np = inet6_sk(ssk);
2138
2139 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2140 return -EMSGSIZE;
2141 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
2142 return -EMSGSIZE;
2143 break;
2144 }
2145 #endif
2146 default:
2147 WARN_ON_ONCE(1);
2148 return -EMSGSIZE;
2149 }
2150
2151 if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2152 return -EMSGSIZE;
2153 if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
2154 return -EMSGSIZE;
2155
2156 sf = mptcp_subflow_ctx(ssk);
2157 if (WARN_ON_ONCE(!sf))
2158 return -EINVAL;
2159
2160 if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf)))
2161 return -EMSGSIZE;
2162
2163 if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
2164 return -EMSGSIZE;
2165
2166 return 0;
2167 }
2168
mptcp_event_put_token_and_ssk(struct sk_buff * skb,const struct mptcp_sock * msk,const struct sock * ssk)2169 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
2170 const struct mptcp_sock *msk,
2171 const struct sock *ssk)
2172 {
2173 const struct sock *sk = (const struct sock *)msk;
2174 const struct mptcp_subflow_context *sf;
2175 u8 sk_err;
2176
2177 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2178 return -EMSGSIZE;
2179
2180 if (mptcp_event_add_subflow(skb, ssk))
2181 return -EMSGSIZE;
2182
2183 sf = mptcp_subflow_ctx(ssk);
2184 if (WARN_ON_ONCE(!sf))
2185 return -EINVAL;
2186
2187 if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
2188 return -EMSGSIZE;
2189
2190 if (ssk->sk_bound_dev_if &&
2191 nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
2192 return -EMSGSIZE;
2193
2194 sk_err = READ_ONCE(ssk->sk_err);
2195 if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
2196 nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
2197 return -EMSGSIZE;
2198
2199 return 0;
2200 }
2201
mptcp_event_sub_established(struct sk_buff * skb,const struct mptcp_sock * msk,const struct sock * ssk)2202 static int mptcp_event_sub_established(struct sk_buff *skb,
2203 const struct mptcp_sock *msk,
2204 const struct sock *ssk)
2205 {
2206 return mptcp_event_put_token_and_ssk(skb, msk, ssk);
2207 }
2208
mptcp_event_sub_closed(struct sk_buff * skb,const struct mptcp_sock * msk,const struct sock * ssk)2209 static int mptcp_event_sub_closed(struct sk_buff *skb,
2210 const struct mptcp_sock *msk,
2211 const struct sock *ssk)
2212 {
2213 const struct mptcp_subflow_context *sf;
2214
2215 if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
2216 return -EMSGSIZE;
2217
2218 sf = mptcp_subflow_ctx(ssk);
2219 if (!sf->reset_seen)
2220 return 0;
2221
2222 if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
2223 return -EMSGSIZE;
2224
2225 if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
2226 return -EMSGSIZE;
2227
2228 return 0;
2229 }
2230
mptcp_event_created(struct sk_buff * skb,const struct mptcp_sock * msk,const struct sock * ssk)2231 static int mptcp_event_created(struct sk_buff *skb,
2232 const struct mptcp_sock *msk,
2233 const struct sock *ssk)
2234 {
2235 int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
2236
2237 if (err)
2238 return err;
2239
2240 if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
2241 return -EMSGSIZE;
2242
2243 return mptcp_event_add_subflow(skb, ssk);
2244 }
2245
mptcp_event_addr_removed(const struct mptcp_sock * msk,uint8_t id)2246 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
2247 {
2248 struct net *net = sock_net((const struct sock *)msk);
2249 struct nlmsghdr *nlh;
2250 struct sk_buff *skb;
2251
2252 if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2253 return;
2254
2255 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2256 if (!skb)
2257 return;
2258
2259 nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
2260 if (!nlh)
2261 goto nla_put_failure;
2262
2263 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2264 goto nla_put_failure;
2265
2266 if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
2267 goto nla_put_failure;
2268
2269 genlmsg_end(skb, nlh);
2270 mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2271 return;
2272
2273 nla_put_failure:
2274 nlmsg_free(skb);
2275 }
2276
mptcp_event_addr_announced(const struct sock * ssk,const struct mptcp_addr_info * info)2277 void mptcp_event_addr_announced(const struct sock *ssk,
2278 const struct mptcp_addr_info *info)
2279 {
2280 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
2281 struct mptcp_sock *msk = mptcp_sk(subflow->conn);
2282 struct net *net = sock_net(ssk);
2283 struct nlmsghdr *nlh;
2284 struct sk_buff *skb;
2285
2286 if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2287 return;
2288
2289 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2290 if (!skb)
2291 return;
2292
2293 nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
2294 MPTCP_EVENT_ANNOUNCED);
2295 if (!nlh)
2296 goto nla_put_failure;
2297
2298 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2299 goto nla_put_failure;
2300
2301 if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2302 goto nla_put_failure;
2303
2304 if (nla_put_be16(skb, MPTCP_ATTR_DPORT,
2305 info->port == 0 ?
2306 inet_sk(ssk)->inet_dport :
2307 info->port))
2308 goto nla_put_failure;
2309
2310 switch (info->family) {
2311 case AF_INET:
2312 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2313 goto nla_put_failure;
2314 break;
2315 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2316 case AF_INET6:
2317 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2318 goto nla_put_failure;
2319 break;
2320 #endif
2321 default:
2322 WARN_ON_ONCE(1);
2323 goto nla_put_failure;
2324 }
2325
2326 genlmsg_end(skb, nlh);
2327 mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2328 return;
2329
2330 nla_put_failure:
2331 nlmsg_free(skb);
2332 }
2333
mptcp_event_pm_listener(const struct sock * ssk,enum mptcp_event_type event)2334 void mptcp_event_pm_listener(const struct sock *ssk,
2335 enum mptcp_event_type event)
2336 {
2337 const struct inet_sock *issk = inet_sk(ssk);
2338 struct net *net = sock_net(ssk);
2339 struct nlmsghdr *nlh;
2340 struct sk_buff *skb;
2341
2342 if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2343 return;
2344
2345 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
2346 if (!skb)
2347 return;
2348
2349 nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event);
2350 if (!nlh)
2351 goto nla_put_failure;
2352
2353 if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2354 goto nla_put_failure;
2355
2356 if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2357 goto nla_put_failure;
2358
2359 switch (ssk->sk_family) {
2360 case AF_INET:
2361 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2362 goto nla_put_failure;
2363 break;
2364 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2365 case AF_INET6: {
2366 const struct ipv6_pinfo *np = inet6_sk(ssk);
2367
2368 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2369 goto nla_put_failure;
2370 break;
2371 }
2372 #endif
2373 default:
2374 WARN_ON_ONCE(1);
2375 goto nla_put_failure;
2376 }
2377
2378 genlmsg_end(skb, nlh);
2379 mptcp_nl_mcast_send(net, skb, GFP_KERNEL);
2380 return;
2381
2382 nla_put_failure:
2383 nlmsg_free(skb);
2384 }
2385
mptcp_event(enum mptcp_event_type type,const struct mptcp_sock * msk,const struct sock * ssk,gfp_t gfp)2386 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2387 const struct sock *ssk, gfp_t gfp)
2388 {
2389 struct net *net = sock_net((const struct sock *)msk);
2390 struct nlmsghdr *nlh;
2391 struct sk_buff *skb;
2392
2393 if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2394 return;
2395
2396 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2397 if (!skb)
2398 return;
2399
2400 nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2401 if (!nlh)
2402 goto nla_put_failure;
2403
2404 switch (type) {
2405 case MPTCP_EVENT_UNSPEC:
2406 WARN_ON_ONCE(1);
2407 break;
2408 case MPTCP_EVENT_CREATED:
2409 case MPTCP_EVENT_ESTABLISHED:
2410 if (mptcp_event_created(skb, msk, ssk) < 0)
2411 goto nla_put_failure;
2412 break;
2413 case MPTCP_EVENT_CLOSED:
2414 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
2415 goto nla_put_failure;
2416 break;
2417 case MPTCP_EVENT_ANNOUNCED:
2418 case MPTCP_EVENT_REMOVED:
2419 /* call mptcp_event_addr_announced()/removed instead */
2420 WARN_ON_ONCE(1);
2421 break;
2422 case MPTCP_EVENT_SUB_ESTABLISHED:
2423 case MPTCP_EVENT_SUB_PRIORITY:
2424 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2425 goto nla_put_failure;
2426 break;
2427 case MPTCP_EVENT_SUB_CLOSED:
2428 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2429 goto nla_put_failure;
2430 break;
2431 case MPTCP_EVENT_LISTENER_CREATED:
2432 case MPTCP_EVENT_LISTENER_CLOSED:
2433 break;
2434 }
2435
2436 genlmsg_end(skb, nlh);
2437 mptcp_nl_mcast_send(net, skb, gfp);
2438 return;
2439
2440 nla_put_failure:
2441 nlmsg_free(skb);
2442 }
2443
2444 static const struct genl_small_ops mptcp_pm_ops[] = {
2445 {
2446 .cmd = MPTCP_PM_CMD_ADD_ADDR,
2447 .doit = mptcp_nl_cmd_add_addr,
2448 .flags = GENL_UNS_ADMIN_PERM,
2449 },
2450 {
2451 .cmd = MPTCP_PM_CMD_DEL_ADDR,
2452 .doit = mptcp_nl_cmd_del_addr,
2453 .flags = GENL_UNS_ADMIN_PERM,
2454 },
2455 {
2456 .cmd = MPTCP_PM_CMD_FLUSH_ADDRS,
2457 .doit = mptcp_nl_cmd_flush_addrs,
2458 .flags = GENL_UNS_ADMIN_PERM,
2459 },
2460 {
2461 .cmd = MPTCP_PM_CMD_GET_ADDR,
2462 .doit = mptcp_nl_cmd_get_addr,
2463 .dumpit = mptcp_nl_cmd_dump_addrs,
2464 },
2465 {
2466 .cmd = MPTCP_PM_CMD_SET_LIMITS,
2467 .doit = mptcp_nl_cmd_set_limits,
2468 .flags = GENL_UNS_ADMIN_PERM,
2469 },
2470 {
2471 .cmd = MPTCP_PM_CMD_GET_LIMITS,
2472 .doit = mptcp_nl_cmd_get_limits,
2473 },
2474 {
2475 .cmd = MPTCP_PM_CMD_SET_FLAGS,
2476 .doit = mptcp_nl_cmd_set_flags,
2477 .flags = GENL_UNS_ADMIN_PERM,
2478 },
2479 {
2480 .cmd = MPTCP_PM_CMD_ANNOUNCE,
2481 .doit = mptcp_nl_cmd_announce,
2482 .flags = GENL_UNS_ADMIN_PERM,
2483 },
2484 {
2485 .cmd = MPTCP_PM_CMD_REMOVE,
2486 .doit = mptcp_nl_cmd_remove,
2487 .flags = GENL_UNS_ADMIN_PERM,
2488 },
2489 {
2490 .cmd = MPTCP_PM_CMD_SUBFLOW_CREATE,
2491 .doit = mptcp_nl_cmd_sf_create,
2492 .flags = GENL_UNS_ADMIN_PERM,
2493 },
2494 {
2495 .cmd = MPTCP_PM_CMD_SUBFLOW_DESTROY,
2496 .doit = mptcp_nl_cmd_sf_destroy,
2497 .flags = GENL_UNS_ADMIN_PERM,
2498 },
2499 };
2500
2501 static struct genl_family mptcp_genl_family __ro_after_init = {
2502 .name = MPTCP_PM_NAME,
2503 .version = MPTCP_PM_VER,
2504 .maxattr = MPTCP_PM_ATTR_MAX,
2505 .policy = mptcp_pm_policy,
2506 .netnsok = true,
2507 .module = THIS_MODULE,
2508 .small_ops = mptcp_pm_ops,
2509 .n_small_ops = ARRAY_SIZE(mptcp_pm_ops),
2510 .resv_start_op = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1,
2511 .mcgrps = mptcp_pm_mcgrps,
2512 .n_mcgrps = ARRAY_SIZE(mptcp_pm_mcgrps),
2513 };
2514
pm_nl_init_net(struct net * net)2515 static int __net_init pm_nl_init_net(struct net *net)
2516 {
2517 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2518
2519 INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2520
2521 /* Cit. 2 subflows ought to be enough for anybody. */
2522 pernet->subflows_max = 2;
2523 pernet->next_id = 1;
2524 pernet->stale_loss_cnt = 4;
2525 spin_lock_init(&pernet->lock);
2526
2527 /* No need to initialize other pernet fields, the struct is zeroed at
2528 * allocation time.
2529 */
2530
2531 return 0;
2532 }
2533
pm_nl_exit_net(struct list_head * net_list)2534 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2535 {
2536 struct net *net;
2537
2538 list_for_each_entry(net, net_list, exit_list) {
2539 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2540
2541 /* net is removed from namespace list, can't race with
2542 * other modifiers, also netns core already waited for a
2543 * RCU grace period.
2544 */
2545 __flush_addrs(&pernet->local_addr_list);
2546 }
2547 }
2548
2549 static struct pernet_operations mptcp_pm_pernet_ops = {
2550 .init = pm_nl_init_net,
2551 .exit_batch = pm_nl_exit_net,
2552 .id = &pm_nl_pernet_id,
2553 .size = sizeof(struct pm_nl_pernet),
2554 };
2555
mptcp_pm_nl_init(void)2556 void __init mptcp_pm_nl_init(void)
2557 {
2558 if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2559 panic("Failed to register MPTCP PM pernet subsystem.\n");
2560
2561 if (genl_register_family(&mptcp_genl_family))
2562 panic("Failed to register MPTCP PM netlink family\n");
2563 }
2564