Merge tag 'x86_build_for_v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-microblaze.git] / net / mptcp / pm_netlink.c
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/netns/generic.h>
13 #include <net/mptcp.h>
14 #include <net/genetlink.h>
15 #include <uapi/linux/mptcp.h>
16
17 #include "protocol.h"
18 #include "mib.h"
19
20 /* forward declaration */
21 static struct genl_family mptcp_genl_family;
22
23 static int pm_nl_pernet_id;
24
25 struct mptcp_pm_addr_entry {
26         struct list_head        list;
27         struct mptcp_addr_info  addr;
28         struct rcu_head         rcu;
29         struct socket           *lsk;
30 };
31
32 struct mptcp_pm_add_entry {
33         struct list_head        list;
34         struct mptcp_addr_info  addr;
35         struct timer_list       add_timer;
36         struct mptcp_sock       *sock;
37         u8                      retrans_times;
38 };
39
40 #define MAX_ADDR_ID             255
41 #define BITMAP_SZ DIV_ROUND_UP(MAX_ADDR_ID + 1, BITS_PER_LONG)
42
43 struct pm_nl_pernet {
44         /* protects pernet updates */
45         spinlock_t              lock;
46         struct list_head        local_addr_list;
47         unsigned int            addrs;
48         unsigned int            add_addr_signal_max;
49         unsigned int            add_addr_accept_max;
50         unsigned int            local_addr_max;
51         unsigned int            subflows_max;
52         unsigned int            next_id;
53         unsigned long           id_bitmap[BITMAP_SZ];
54 };
55
56 #define MPTCP_PM_ADDR_MAX       8
57 #define ADD_ADDR_RETRANS_MAX    3
58
59 static void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk);
60
61 static bool addresses_equal(const struct mptcp_addr_info *a,
62                             struct mptcp_addr_info *b, bool use_port)
63 {
64         bool addr_equals = false;
65
66         if (a->family == b->family) {
67                 if (a->family == AF_INET)
68                         addr_equals = a->addr.s_addr == b->addr.s_addr;
69 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
70                 else
71                         addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
72         } else if (a->family == AF_INET) {
73                 if (ipv6_addr_v4mapped(&b->addr6))
74                         addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
75         } else if (b->family == AF_INET) {
76                 if (ipv6_addr_v4mapped(&a->addr6))
77                         addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
78 #endif
79         }
80
81         if (!addr_equals)
82                 return false;
83         if (!use_port)
84                 return true;
85
86         return a->port == b->port;
87 }
88
89 static bool address_zero(const struct mptcp_addr_info *addr)
90 {
91         struct mptcp_addr_info zero;
92
93         memset(&zero, 0, sizeof(zero));
94         zero.family = addr->family;
95
96         return addresses_equal(addr, &zero, true);
97 }
98
99 static void local_address(const struct sock_common *skc,
100                           struct mptcp_addr_info *addr)
101 {
102         addr->family = skc->skc_family;
103         addr->port = htons(skc->skc_num);
104         if (addr->family == AF_INET)
105                 addr->addr.s_addr = skc->skc_rcv_saddr;
106 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
107         else if (addr->family == AF_INET6)
108                 addr->addr6 = skc->skc_v6_rcv_saddr;
109 #endif
110 }
111
112 static void remote_address(const struct sock_common *skc,
113                            struct mptcp_addr_info *addr)
114 {
115         addr->family = skc->skc_family;
116         addr->port = skc->skc_dport;
117         if (addr->family == AF_INET)
118                 addr->addr.s_addr = skc->skc_daddr;
119 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
120         else if (addr->family == AF_INET6)
121                 addr->addr6 = skc->skc_v6_daddr;
122 #endif
123 }
124
125 static bool lookup_subflow_by_saddr(const struct list_head *list,
126                                     struct mptcp_addr_info *saddr)
127 {
128         struct mptcp_subflow_context *subflow;
129         struct mptcp_addr_info cur;
130         struct sock_common *skc;
131
132         list_for_each_entry(subflow, list, node) {
133                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
134
135                 local_address(skc, &cur);
136                 if (addresses_equal(&cur, saddr, saddr->port))
137                         return true;
138         }
139
140         return false;
141 }
142
143 static struct mptcp_pm_addr_entry *
144 select_local_address(const struct pm_nl_pernet *pernet,
145                      struct mptcp_sock *msk)
146 {
147         struct mptcp_pm_addr_entry *entry, *ret = NULL;
148         struct sock *sk = (struct sock *)msk;
149
150         msk_owned_by_me(msk);
151
152         rcu_read_lock();
153         __mptcp_flush_join_list(msk);
154         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
155                 if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
156                         continue;
157
158                 if (entry->addr.family != sk->sk_family) {
159 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
160                         if ((entry->addr.family == AF_INET &&
161                              !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
162                             (sk->sk_family == AF_INET &&
163                              !ipv6_addr_v4mapped(&entry->addr.addr6)))
164 #endif
165                                 continue;
166                 }
167
168                 /* avoid any address already in use by subflows and
169                  * pending join
170                  */
171                 if (!lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) {
172                         ret = entry;
173                         break;
174                 }
175         }
176         rcu_read_unlock();
177         return ret;
178 }
179
180 static struct mptcp_pm_addr_entry *
181 select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos)
182 {
183         struct mptcp_pm_addr_entry *entry, *ret = NULL;
184         int i = 0;
185
186         rcu_read_lock();
187         /* do not keep any additional per socket state, just signal
188          * the address list in order.
189          * Note: removal from the local address list during the msk life-cycle
190          * can lead to additional addresses not being announced.
191          */
192         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
193                 if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
194                         continue;
195                 if (i++ == pos) {
196                         ret = entry;
197                         break;
198                 }
199         }
200         rcu_read_unlock();
201         return ret;
202 }
203
204 unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk)
205 {
206         struct pm_nl_pernet *pernet;
207
208         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
209         return READ_ONCE(pernet->add_addr_signal_max);
210 }
211 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
212
213 unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk)
214 {
215         struct pm_nl_pernet *pernet;
216
217         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
218         return READ_ONCE(pernet->add_addr_accept_max);
219 }
220 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
221
222 unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk)
223 {
224         struct pm_nl_pernet *pernet;
225
226         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
227         return READ_ONCE(pernet->subflows_max);
228 }
229 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
230
231 unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk)
232 {
233         struct pm_nl_pernet *pernet;
234
235         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
236         return READ_ONCE(pernet->local_addr_max);
237 }
238 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
239
240 static void check_work_pending(struct mptcp_sock *msk)
241 {
242         if (msk->pm.add_addr_signaled == mptcp_pm_get_add_addr_signal_max(msk) &&
243             (msk->pm.local_addr_used == mptcp_pm_get_local_addr_max(msk) ||
244              msk->pm.subflows == mptcp_pm_get_subflows_max(msk)))
245                 WRITE_ONCE(msk->pm.work_pending, false);
246 }
247
248 static struct mptcp_pm_add_entry *
249 lookup_anno_list_by_saddr(struct mptcp_sock *msk,
250                           struct mptcp_addr_info *addr)
251 {
252         struct mptcp_pm_add_entry *entry;
253
254         lockdep_assert_held(&msk->pm.lock);
255
256         list_for_each_entry(entry, &msk->pm.anno_list, list) {
257                 if (addresses_equal(&entry->addr, addr, true))
258                         return entry;
259         }
260
261         return NULL;
262 }
263
264 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
265 {
266         struct mptcp_pm_add_entry *entry;
267         struct mptcp_addr_info saddr;
268         bool ret = false;
269
270         local_address((struct sock_common *)sk, &saddr);
271
272         spin_lock_bh(&msk->pm.lock);
273         list_for_each_entry(entry, &msk->pm.anno_list, list) {
274                 if (addresses_equal(&entry->addr, &saddr, true)) {
275                         ret = true;
276                         goto out;
277                 }
278         }
279
280 out:
281         spin_unlock_bh(&msk->pm.lock);
282         return ret;
283 }
284
285 static void mptcp_pm_add_timer(struct timer_list *timer)
286 {
287         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
288         struct mptcp_sock *msk = entry->sock;
289         struct sock *sk = (struct sock *)msk;
290
291         pr_debug("msk=%p", msk);
292
293         if (!msk)
294                 return;
295
296         if (inet_sk_state_load(sk) == TCP_CLOSE)
297                 return;
298
299         if (!entry->addr.id)
300                 return;
301
302         if (mptcp_pm_should_add_signal(msk)) {
303                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
304                 goto out;
305         }
306
307         spin_lock_bh(&msk->pm.lock);
308
309         if (!mptcp_pm_should_add_signal(msk)) {
310                 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
311                 mptcp_pm_announce_addr(msk, &entry->addr, false, entry->addr.port);
312                 mptcp_pm_add_addr_send_ack(msk);
313                 entry->retrans_times++;
314         }
315
316         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
317                 sk_reset_timer(sk, timer,
318                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
319
320         spin_unlock_bh(&msk->pm.lock);
321
322 out:
323         __sock_put(sk);
324 }
325
326 struct mptcp_pm_add_entry *
327 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
328                        struct mptcp_addr_info *addr)
329 {
330         struct mptcp_pm_add_entry *entry;
331         struct sock *sk = (struct sock *)msk;
332
333         spin_lock_bh(&msk->pm.lock);
334         entry = lookup_anno_list_by_saddr(msk, addr);
335         if (entry)
336                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
337         spin_unlock_bh(&msk->pm.lock);
338
339         if (entry)
340                 sk_stop_timer_sync(sk, &entry->add_timer);
341
342         return entry;
343 }
344
345 static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
346                                      struct mptcp_pm_addr_entry *entry)
347 {
348         struct mptcp_pm_add_entry *add_entry = NULL;
349         struct sock *sk = (struct sock *)msk;
350         struct net *net = sock_net(sk);
351
352         lockdep_assert_held(&msk->pm.lock);
353
354         if (lookup_anno_list_by_saddr(msk, &entry->addr))
355                 return false;
356
357         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
358         if (!add_entry)
359                 return false;
360
361         list_add(&add_entry->list, &msk->pm.anno_list);
362
363         add_entry->addr = entry->addr;
364         add_entry->sock = msk;
365         add_entry->retrans_times = 0;
366
367         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
368         sk_reset_timer(sk, &add_entry->add_timer,
369                        jiffies + mptcp_get_add_addr_timeout(net));
370
371         return true;
372 }
373
374 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
375 {
376         struct mptcp_pm_add_entry *entry, *tmp;
377         struct sock *sk = (struct sock *)msk;
378         LIST_HEAD(free_list);
379
380         pr_debug("msk=%p", msk);
381
382         spin_lock_bh(&msk->pm.lock);
383         list_splice_init(&msk->pm.anno_list, &free_list);
384         spin_unlock_bh(&msk->pm.lock);
385
386         list_for_each_entry_safe(entry, tmp, &free_list, list) {
387                 sk_stop_timer_sync(sk, &entry->add_timer);
388                 kfree(entry);
389         }
390 }
391
392 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
393 {
394         struct sock *sk = (struct sock *)msk;
395         struct mptcp_pm_addr_entry *local;
396         unsigned int add_addr_signal_max;
397         unsigned int local_addr_max;
398         struct pm_nl_pernet *pernet;
399         unsigned int subflows_max;
400
401         pernet = net_generic(sock_net(sk), pm_nl_pernet_id);
402
403         add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
404         local_addr_max = mptcp_pm_get_local_addr_max(msk);
405         subflows_max = mptcp_pm_get_subflows_max(msk);
406
407         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
408                  msk->pm.local_addr_used, local_addr_max,
409                  msk->pm.add_addr_signaled, add_addr_signal_max,
410                  msk->pm.subflows, subflows_max);
411
412         /* check first for announce */
413         if (msk->pm.add_addr_signaled < add_addr_signal_max) {
414                 local = select_signal_address(pernet,
415                                               msk->pm.add_addr_signaled);
416
417                 if (local) {
418                         if (mptcp_pm_alloc_anno_list(msk, local)) {
419                                 msk->pm.add_addr_signaled++;
420                                 mptcp_pm_announce_addr(msk, &local->addr, false, local->addr.port);
421                                 mptcp_pm_nl_add_addr_send_ack(msk);
422                         }
423                 } else {
424                         /* pick failed, avoid fourther attempts later */
425                         msk->pm.local_addr_used = add_addr_signal_max;
426                 }
427
428                 check_work_pending(msk);
429         }
430
431         /* check if should create a new subflow */
432         if (msk->pm.local_addr_used < local_addr_max &&
433             msk->pm.subflows < subflows_max) {
434                 local = select_local_address(pernet, msk);
435                 if (local) {
436                         struct mptcp_addr_info remote = { 0 };
437
438                         msk->pm.local_addr_used++;
439                         msk->pm.subflows++;
440                         check_work_pending(msk);
441                         remote_address((struct sock_common *)sk, &remote);
442                         spin_unlock_bh(&msk->pm.lock);
443                         __mptcp_subflow_connect(sk, &local->addr, &remote);
444                         spin_lock_bh(&msk->pm.lock);
445                         return;
446                 }
447
448                 /* lookup failed, avoid fourther attempts later */
449                 msk->pm.local_addr_used = local_addr_max;
450                 check_work_pending(msk);
451         }
452 }
453
454 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
455 {
456         mptcp_pm_create_subflow_or_signal_addr(msk);
457 }
458
459 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
460 {
461         mptcp_pm_create_subflow_or_signal_addr(msk);
462 }
463
464 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
465 {
466         struct sock *sk = (struct sock *)msk;
467         unsigned int add_addr_accept_max;
468         struct mptcp_addr_info remote;
469         struct mptcp_addr_info local;
470         unsigned int subflows_max;
471         bool use_port = false;
472
473         add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
474         subflows_max = mptcp_pm_get_subflows_max(msk);
475
476         pr_debug("accepted %d:%d remote family %d",
477                  msk->pm.add_addr_accepted, add_addr_accept_max,
478                  msk->pm.remote.family);
479         msk->pm.add_addr_accepted++;
480         msk->pm.subflows++;
481         if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
482             msk->pm.subflows >= subflows_max)
483                 WRITE_ONCE(msk->pm.accept_addr, false);
484
485         /* connect to the specified remote address, using whatever
486          * local address the routing configuration will pick.
487          */
488         remote = msk->pm.remote;
489         if (!remote.port)
490                 remote.port = sk->sk_dport;
491         else
492                 use_port = true;
493         memset(&local, 0, sizeof(local));
494         local.family = remote.family;
495
496         spin_unlock_bh(&msk->pm.lock);
497         __mptcp_subflow_connect(sk, &local, &remote);
498         spin_lock_bh(&msk->pm.lock);
499
500         mptcp_pm_announce_addr(msk, &remote, true, use_port);
501         mptcp_pm_nl_add_addr_send_ack(msk);
502 }
503
504 static void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
505 {
506         struct mptcp_subflow_context *subflow;
507
508         msk_owned_by_me(msk);
509         lockdep_assert_held(&msk->pm.lock);
510
511         if (!mptcp_pm_should_add_signal(msk))
512                 return;
513
514         __mptcp_flush_join_list(msk);
515         subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
516         if (subflow) {
517                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
518                 u8 add_addr;
519
520                 spin_unlock_bh(&msk->pm.lock);
521                 pr_debug("send ack for add_addr%s%s",
522                          mptcp_pm_should_add_signal_ipv6(msk) ? " [ipv6]" : "",
523                          mptcp_pm_should_add_signal_port(msk) ? " [port]" : "");
524
525                 lock_sock(ssk);
526                 tcp_send_ack(ssk);
527                 release_sock(ssk);
528                 spin_lock_bh(&msk->pm.lock);
529
530                 add_addr = READ_ONCE(msk->pm.addr_signal);
531                 if (mptcp_pm_should_add_signal_ipv6(msk))
532                         add_addr &= ~BIT(MPTCP_ADD_ADDR_IPV6);
533                 if (mptcp_pm_should_add_signal_port(msk))
534                         add_addr &= ~BIT(MPTCP_ADD_ADDR_PORT);
535                 WRITE_ONCE(msk->pm.addr_signal, add_addr);
536         }
537 }
538
539 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
540                                  struct mptcp_addr_info *addr,
541                                  u8 bkup)
542 {
543         struct mptcp_subflow_context *subflow;
544
545         pr_debug("bkup=%d", bkup);
546
547         mptcp_for_each_subflow(msk, subflow) {
548                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
549                 struct sock *sk = (struct sock *)msk;
550                 struct mptcp_addr_info local;
551
552                 local_address((struct sock_common *)ssk, &local);
553                 if (!addresses_equal(&local, addr, addr->port))
554                         continue;
555
556                 subflow->backup = bkup;
557                 subflow->send_mp_prio = 1;
558                 subflow->request_bkup = bkup;
559                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIOTX);
560
561                 spin_unlock_bh(&msk->pm.lock);
562                 pr_debug("send ack for mp_prio");
563                 lock_sock(ssk);
564                 tcp_send_ack(ssk);
565                 release_sock(ssk);
566                 spin_lock_bh(&msk->pm.lock);
567
568                 return 0;
569         }
570
571         return -EINVAL;
572 }
573
574 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
575 {
576         struct mptcp_subflow_context *subflow, *tmp;
577         struct sock *sk = (struct sock *)msk;
578
579         pr_debug("address rm_id %d", msk->pm.rm_id);
580
581         msk_owned_by_me(msk);
582
583         if (!msk->pm.rm_id)
584                 return;
585
586         if (list_empty(&msk->conn_list))
587                 return;
588
589         list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
590                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
591                 int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
592
593                 if (msk->pm.rm_id != subflow->remote_id)
594                         continue;
595
596                 spin_unlock_bh(&msk->pm.lock);
597                 mptcp_subflow_shutdown(sk, ssk, how);
598                 mptcp_close_ssk(sk, ssk, subflow);
599                 spin_lock_bh(&msk->pm.lock);
600
601                 msk->pm.add_addr_accepted--;
602                 msk->pm.subflows--;
603                 WRITE_ONCE(msk->pm.accept_addr, true);
604
605                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMADDR);
606
607                 break;
608         }
609 }
610
611 void mptcp_pm_nl_work(struct mptcp_sock *msk)
612 {
613         struct mptcp_pm_data *pm = &msk->pm;
614
615         msk_owned_by_me(msk);
616
617         spin_lock_bh(&msk->pm.lock);
618
619         pr_debug("msk=%p status=%x", msk, pm->status);
620         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
621                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
622                 mptcp_pm_nl_add_addr_received(msk);
623         }
624         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
625                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
626                 mptcp_pm_nl_add_addr_send_ack(msk);
627         }
628         if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
629                 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
630                 mptcp_pm_nl_rm_addr_received(msk);
631         }
632         if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
633                 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
634                 mptcp_pm_nl_fully_established(msk);
635         }
636         if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
637                 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
638                 mptcp_pm_nl_subflow_established(msk);
639         }
640
641         spin_unlock_bh(&msk->pm.lock);
642 }
643
644 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id)
645 {
646         struct mptcp_subflow_context *subflow, *tmp;
647         struct sock *sk = (struct sock *)msk;
648
649         pr_debug("subflow rm_id %d", rm_id);
650
651         msk_owned_by_me(msk);
652
653         if (!rm_id)
654                 return;
655
656         if (list_empty(&msk->conn_list))
657                 return;
658
659         list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
660                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
661                 int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
662
663                 if (rm_id != subflow->local_id)
664                         continue;
665
666                 spin_unlock_bh(&msk->pm.lock);
667                 mptcp_subflow_shutdown(sk, ssk, how);
668                 mptcp_close_ssk(sk, ssk, subflow);
669                 spin_lock_bh(&msk->pm.lock);
670
671                 msk->pm.local_addr_used--;
672                 msk->pm.subflows--;
673
674                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
675
676                 break;
677         }
678 }
679
680 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
681 {
682         return (entry->addr.flags &
683                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
684                 MPTCP_PM_ADDR_FLAG_SIGNAL;
685 }
686
687 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
688                                              struct mptcp_pm_addr_entry *entry)
689 {
690         struct mptcp_pm_addr_entry *cur;
691         unsigned int addr_max;
692         int ret = -EINVAL;
693
694         spin_lock_bh(&pernet->lock);
695         /* to keep the code simple, don't do IDR-like allocation for address ID,
696          * just bail when we exceed limits
697          */
698         if (pernet->next_id == MAX_ADDR_ID)
699                 pernet->next_id = 1;
700         if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
701                 goto out;
702         if (test_bit(entry->addr.id, pernet->id_bitmap))
703                 goto out;
704
705         /* do not insert duplicate address, differentiate on port only
706          * singled addresses
707          */
708         list_for_each_entry(cur, &pernet->local_addr_list, list) {
709                 if (addresses_equal(&cur->addr, &entry->addr,
710                                     address_use_port(entry) &&
711                                     address_use_port(cur)))
712                         goto out;
713         }
714
715         if (!entry->addr.id) {
716 find_next:
717                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
718                                                     MAX_ADDR_ID + 1,
719                                                     pernet->next_id);
720                 if ((!entry->addr.id || entry->addr.id > MAX_ADDR_ID) &&
721                     pernet->next_id != 1) {
722                         pernet->next_id = 1;
723                         goto find_next;
724                 }
725         }
726
727         if (!entry->addr.id || entry->addr.id > MAX_ADDR_ID)
728                 goto out;
729
730         __set_bit(entry->addr.id, pernet->id_bitmap);
731         if (entry->addr.id > pernet->next_id)
732                 pernet->next_id = entry->addr.id;
733
734         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
735                 addr_max = pernet->add_addr_signal_max;
736                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
737         }
738         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
739                 addr_max = pernet->local_addr_max;
740                 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
741         }
742
743         pernet->addrs++;
744         list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
745         ret = entry->addr.id;
746
747 out:
748         spin_unlock_bh(&pernet->lock);
749         return ret;
750 }
751
752 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
753                                             struct mptcp_pm_addr_entry *entry)
754 {
755         struct sockaddr_storage addr;
756         struct mptcp_sock *msk;
757         struct socket *ssock;
758         int backlog = 1024;
759         int err;
760
761         err = sock_create_kern(sock_net(sk), entry->addr.family,
762                                SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
763         if (err)
764                 return err;
765
766         msk = mptcp_sk(entry->lsk->sk);
767         if (!msk) {
768                 err = -EINVAL;
769                 goto out;
770         }
771
772         ssock = __mptcp_nmpc_socket(msk);
773         if (!ssock) {
774                 err = -EINVAL;
775                 goto out;
776         }
777
778         mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
779         err = kernel_bind(ssock, (struct sockaddr *)&addr,
780                           sizeof(struct sockaddr_in));
781         if (err) {
782                 pr_warn("kernel_bind error, err=%d", err);
783                 goto out;
784         }
785
786         err = kernel_listen(ssock, backlog);
787         if (err) {
788                 pr_warn("kernel_listen error, err=%d", err);
789                 goto out;
790         }
791
792         return 0;
793
794 out:
795         sock_release(entry->lsk);
796         return err;
797 }
798
799 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
800 {
801         struct mptcp_pm_addr_entry *entry;
802         struct mptcp_addr_info skc_local;
803         struct mptcp_addr_info msk_local;
804         struct pm_nl_pernet *pernet;
805         int ret = -1;
806
807         if (WARN_ON_ONCE(!msk))
808                 return -1;
809
810         /* The 0 ID mapping is defined by the first subflow, copied into the msk
811          * addr
812          */
813         local_address((struct sock_common *)msk, &msk_local);
814         local_address((struct sock_common *)skc, &skc_local);
815         if (addresses_equal(&msk_local, &skc_local, false))
816                 return 0;
817
818         if (address_zero(&skc_local))
819                 return 0;
820
821         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
822
823         rcu_read_lock();
824         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
825                 if (addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
826                         ret = entry->addr.id;
827                         break;
828                 }
829         }
830         rcu_read_unlock();
831         if (ret >= 0)
832                 return ret;
833
834         /* address not found, add to local list */
835         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
836         if (!entry)
837                 return -ENOMEM;
838
839         entry->addr = skc_local;
840         entry->addr.ifindex = 0;
841         entry->addr.flags = 0;
842         entry->addr.id = 0;
843         entry->addr.port = 0;
844         entry->lsk = NULL;
845         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
846         if (ret < 0)
847                 kfree(entry);
848
849         return ret;
850 }
851
852 void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
853 {
854         struct mptcp_pm_data *pm = &msk->pm;
855         bool subflows;
856
857         subflows = !!mptcp_pm_get_subflows_max(msk);
858         WRITE_ONCE(pm->work_pending, (!!mptcp_pm_get_local_addr_max(msk) && subflows) ||
859                    !!mptcp_pm_get_add_addr_signal_max(msk));
860         WRITE_ONCE(pm->accept_addr, !!mptcp_pm_get_add_addr_accept_max(msk) && subflows);
861         WRITE_ONCE(pm->accept_subflow, subflows);
862 }
863
864 #define MPTCP_PM_CMD_GRP_OFFSET       0
865 #define MPTCP_PM_EV_GRP_OFFSET        1
866
867 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
868         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
869         [MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
870                                             .flags = GENL_UNS_ADMIN_PERM,
871                                           },
872 };
873
874 static const struct nla_policy
875 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
876         [MPTCP_PM_ADDR_ATTR_FAMILY]     = { .type       = NLA_U16,      },
877         [MPTCP_PM_ADDR_ATTR_ID]         = { .type       = NLA_U8,       },
878         [MPTCP_PM_ADDR_ATTR_ADDR4]      = { .type       = NLA_U32,      },
879         [MPTCP_PM_ADDR_ATTR_ADDR6]      =
880                 NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
881         [MPTCP_PM_ADDR_ATTR_PORT]       = { .type       = NLA_U16       },
882         [MPTCP_PM_ADDR_ATTR_FLAGS]      = { .type       = NLA_U32       },
883         [MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type       = NLA_S32       },
884 };
885
886 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
887         [MPTCP_PM_ATTR_ADDR]            =
888                                         NLA_POLICY_NESTED(mptcp_pm_addr_policy),
889         [MPTCP_PM_ATTR_RCV_ADD_ADDRS]   = { .type       = NLA_U32,      },
890         [MPTCP_PM_ATTR_SUBFLOWS]        = { .type       = NLA_U32,      },
891 };
892
893 static int mptcp_pm_family_to_addr(int family)
894 {
895 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
896         if (family == AF_INET6)
897                 return MPTCP_PM_ADDR_ATTR_ADDR6;
898 #endif
899         return MPTCP_PM_ADDR_ATTR_ADDR4;
900 }
901
902 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
903                                bool require_family,
904                                struct mptcp_pm_addr_entry *entry)
905 {
906         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
907         int err, addr_addr;
908
909         if (!attr) {
910                 GENL_SET_ERR_MSG(info, "missing address info");
911                 return -EINVAL;
912         }
913
914         /* no validation needed - was already done via nested policy */
915         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
916                                           mptcp_pm_addr_policy, info->extack);
917         if (err)
918                 return err;
919
920         memset(entry, 0, sizeof(*entry));
921         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
922                 if (!require_family)
923                         goto skip_family;
924
925                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
926                                     "missing family");
927                 return -EINVAL;
928         }
929
930         entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
931         if (entry->addr.family != AF_INET
932 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
933             && entry->addr.family != AF_INET6
934 #endif
935             ) {
936                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
937                                     "unknown address family");
938                 return -EINVAL;
939         }
940         addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
941         if (!tb[addr_addr]) {
942                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
943                                     "missing address data");
944                 return -EINVAL;
945         }
946
947 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
948         if (entry->addr.family == AF_INET6)
949                 entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
950         else
951 #endif
952                 entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
953
954 skip_family:
955         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
956                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
957
958                 entry->addr.ifindex = val;
959         }
960
961         if (tb[MPTCP_PM_ADDR_ATTR_ID])
962                 entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
963
964         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
965                 entry->addr.flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
966
967         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
968                 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
969
970         return 0;
971 }
972
973 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
974 {
975         return net_generic(genl_info_net(info), pm_nl_pernet_id);
976 }
977
978 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
979 {
980         struct mptcp_sock *msk;
981         long s_slot = 0, s_num = 0;
982
983         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
984                 struct sock *sk = (struct sock *)msk;
985
986                 if (!READ_ONCE(msk->fully_established))
987                         goto next;
988
989                 lock_sock(sk);
990                 spin_lock_bh(&msk->pm.lock);
991                 mptcp_pm_create_subflow_or_signal_addr(msk);
992                 spin_unlock_bh(&msk->pm.lock);
993                 release_sock(sk);
994
995 next:
996                 sock_put(sk);
997                 cond_resched();
998         }
999
1000         return 0;
1001 }
1002
1003 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1004 {
1005         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1006         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1007         struct mptcp_pm_addr_entry addr, *entry;
1008         int ret;
1009
1010         ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1011         if (ret < 0)
1012                 return ret;
1013
1014         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1015         if (!entry) {
1016                 GENL_SET_ERR_MSG(info, "can't allocate addr");
1017                 return -ENOMEM;
1018         }
1019
1020         *entry = addr;
1021         if (entry->addr.port) {
1022                 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1023                 if (ret) {
1024                         GENL_SET_ERR_MSG(info, "create listen socket error");
1025                         kfree(entry);
1026                         return ret;
1027                 }
1028         }
1029         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1030         if (ret < 0) {
1031                 GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
1032                 if (entry->lsk)
1033                         sock_release(entry->lsk);
1034                 kfree(entry);
1035                 return ret;
1036         }
1037
1038         mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1039
1040         return 0;
1041 }
1042
1043 static struct mptcp_pm_addr_entry *
1044 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
1045 {
1046         struct mptcp_pm_addr_entry *entry;
1047
1048         list_for_each_entry(entry, &pernet->local_addr_list, list) {
1049                 if (entry->addr.id == id)
1050                         return entry;
1051         }
1052         return NULL;
1053 }
1054
1055 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1056                                       struct mptcp_addr_info *addr)
1057 {
1058         struct mptcp_pm_add_entry *entry;
1059
1060         entry = mptcp_pm_del_add_timer(msk, addr);
1061         if (entry) {
1062                 list_del(&entry->list);
1063                 kfree(entry);
1064                 return true;
1065         }
1066
1067         return false;
1068 }
1069
1070 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1071                                       struct mptcp_addr_info *addr,
1072                                       bool force)
1073 {
1074         bool ret;
1075
1076         ret = remove_anno_list_by_saddr(msk, addr);
1077         if (ret || force) {
1078                 spin_lock_bh(&msk->pm.lock);
1079                 mptcp_pm_remove_addr(msk, addr->id);
1080                 spin_unlock_bh(&msk->pm.lock);
1081         }
1082         return ret;
1083 }
1084
1085 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1086                                                    struct mptcp_addr_info *addr)
1087 {
1088         struct mptcp_sock *msk;
1089         long s_slot = 0, s_num = 0;
1090
1091         pr_debug("remove_id=%d", addr->id);
1092
1093         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1094                 struct sock *sk = (struct sock *)msk;
1095                 bool remove_subflow;
1096
1097                 if (list_empty(&msk->conn_list)) {
1098                         mptcp_pm_remove_anno_addr(msk, addr, false);
1099                         goto next;
1100                 }
1101
1102                 lock_sock(sk);
1103                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1104                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
1105                 if (remove_subflow)
1106                         mptcp_pm_remove_subflow(msk, addr->id);
1107                 release_sock(sk);
1108
1109 next:
1110                 sock_put(sk);
1111                 cond_resched();
1112         }
1113
1114         return 0;
1115 }
1116
1117 struct addr_entry_release_work {
1118         struct rcu_work rwork;
1119         struct mptcp_pm_addr_entry *entry;
1120 };
1121
1122 static void mptcp_pm_release_addr_entry(struct work_struct *work)
1123 {
1124         struct addr_entry_release_work *w;
1125         struct mptcp_pm_addr_entry *entry;
1126
1127         w = container_of(to_rcu_work(work), struct addr_entry_release_work, rwork);
1128         entry = w->entry;
1129         if (entry) {
1130                 if (entry->lsk)
1131                         sock_release(entry->lsk);
1132                 kfree(entry);
1133         }
1134         kfree(w);
1135 }
1136
1137 static void mptcp_pm_free_addr_entry(struct mptcp_pm_addr_entry *entry)
1138 {
1139         struct addr_entry_release_work *w;
1140
1141         w = kmalloc(sizeof(*w), GFP_ATOMIC);
1142         if (w) {
1143                 INIT_RCU_WORK(&w->rwork, mptcp_pm_release_addr_entry);
1144                 w->entry = entry;
1145                 queue_rcu_work(system_wq, &w->rwork);
1146         }
1147 }
1148
1149 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1150 {
1151         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1152         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1153         struct mptcp_pm_addr_entry addr, *entry;
1154         unsigned int addr_max;
1155         int ret;
1156
1157         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1158         if (ret < 0)
1159                 return ret;
1160
1161         spin_lock_bh(&pernet->lock);
1162         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1163         if (!entry) {
1164                 GENL_SET_ERR_MSG(info, "address not found");
1165                 spin_unlock_bh(&pernet->lock);
1166                 return -EINVAL;
1167         }
1168         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1169                 addr_max = pernet->add_addr_signal_max;
1170                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1171         }
1172         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1173                 addr_max = pernet->local_addr_max;
1174                 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1175         }
1176
1177         pernet->addrs--;
1178         list_del_rcu(&entry->list);
1179         __clear_bit(entry->addr.id, pernet->id_bitmap);
1180         spin_unlock_bh(&pernet->lock);
1181
1182         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
1183         mptcp_pm_free_addr_entry(entry);
1184
1185         return ret;
1186 }
1187
1188 static void __flush_addrs(struct net *net, struct list_head *list)
1189 {
1190         while (!list_empty(list)) {
1191                 struct mptcp_pm_addr_entry *cur;
1192
1193                 cur = list_entry(list->next,
1194                                  struct mptcp_pm_addr_entry, list);
1195                 mptcp_nl_remove_subflow_and_signal_addr(net, &cur->addr);
1196                 list_del_rcu(&cur->list);
1197                 mptcp_pm_free_addr_entry(cur);
1198         }
1199 }
1200
1201 static void __reset_counters(struct pm_nl_pernet *pernet)
1202 {
1203         WRITE_ONCE(pernet->add_addr_signal_max, 0);
1204         WRITE_ONCE(pernet->add_addr_accept_max, 0);
1205         WRITE_ONCE(pernet->local_addr_max, 0);
1206         pernet->addrs = 0;
1207 }
1208
1209 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1210 {
1211         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1212         LIST_HEAD(free_list);
1213
1214         spin_lock_bh(&pernet->lock);
1215         list_splice_init(&pernet->local_addr_list, &free_list);
1216         __reset_counters(pernet);
1217         pernet->next_id = 1;
1218         bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
1219         spin_unlock_bh(&pernet->lock);
1220         __flush_addrs(sock_net(skb->sk), &free_list);
1221         return 0;
1222 }
1223
1224 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1225                               struct mptcp_pm_addr_entry *entry)
1226 {
1227         struct mptcp_addr_info *addr = &entry->addr;
1228         struct nlattr *attr;
1229
1230         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1231         if (!attr)
1232                 return -EMSGSIZE;
1233
1234         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1235                 goto nla_put_failure;
1236         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1237                 goto nla_put_failure;
1238         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1239                 goto nla_put_failure;
1240         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->addr.flags))
1241                 goto nla_put_failure;
1242         if (entry->addr.ifindex &&
1243             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->addr.ifindex))
1244                 goto nla_put_failure;
1245
1246         if (addr->family == AF_INET &&
1247             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1248                             addr->addr.s_addr))
1249                 goto nla_put_failure;
1250 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1251         else if (addr->family == AF_INET6 &&
1252                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1253                 goto nla_put_failure;
1254 #endif
1255         nla_nest_end(skb, attr);
1256         return 0;
1257
1258 nla_put_failure:
1259         nla_nest_cancel(skb, attr);
1260         return -EMSGSIZE;
1261 }
1262
1263 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1264 {
1265         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1266         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1267         struct mptcp_pm_addr_entry addr, *entry;
1268         struct sk_buff *msg;
1269         void *reply;
1270         int ret;
1271
1272         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1273         if (ret < 0)
1274                 return ret;
1275
1276         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1277         if (!msg)
1278                 return -ENOMEM;
1279
1280         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1281                                   info->genlhdr->cmd);
1282         if (!reply) {
1283                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1284                 ret = -EMSGSIZE;
1285                 goto fail;
1286         }
1287
1288         spin_lock_bh(&pernet->lock);
1289         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1290         if (!entry) {
1291                 GENL_SET_ERR_MSG(info, "address not found");
1292                 ret = -EINVAL;
1293                 goto unlock_fail;
1294         }
1295
1296         ret = mptcp_nl_fill_addr(msg, entry);
1297         if (ret)
1298                 goto unlock_fail;
1299
1300         genlmsg_end(msg, reply);
1301         ret = genlmsg_reply(msg, info);
1302         spin_unlock_bh(&pernet->lock);
1303         return ret;
1304
1305 unlock_fail:
1306         spin_unlock_bh(&pernet->lock);
1307
1308 fail:
1309         nlmsg_free(msg);
1310         return ret;
1311 }
1312
1313 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1314                                    struct netlink_callback *cb)
1315 {
1316         struct net *net = sock_net(msg->sk);
1317         struct mptcp_pm_addr_entry *entry;
1318         struct pm_nl_pernet *pernet;
1319         int id = cb->args[0];
1320         void *hdr;
1321         int i;
1322
1323         pernet = net_generic(net, pm_nl_pernet_id);
1324
1325         spin_lock_bh(&pernet->lock);
1326         for (i = id; i < MAX_ADDR_ID + 1; i++) {
1327                 if (test_bit(i, pernet->id_bitmap)) {
1328                         entry = __lookup_addr_by_id(pernet, i);
1329                         if (!entry)
1330                                 break;
1331
1332                         if (entry->addr.id <= id)
1333                                 continue;
1334
1335                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1336                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1337                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1338                         if (!hdr)
1339                                 break;
1340
1341                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1342                                 genlmsg_cancel(msg, hdr);
1343                                 break;
1344                         }
1345
1346                         id = entry->addr.id;
1347                         genlmsg_end(msg, hdr);
1348                 }
1349         }
1350         spin_unlock_bh(&pernet->lock);
1351
1352         cb->args[0] = id;
1353         return msg->len;
1354 }
1355
1356 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1357 {
1358         struct nlattr *attr = info->attrs[id];
1359
1360         if (!attr)
1361                 return 0;
1362
1363         *limit = nla_get_u32(attr);
1364         if (*limit > MPTCP_PM_ADDR_MAX) {
1365                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1366                 return -EINVAL;
1367         }
1368         return 0;
1369 }
1370
1371 static int
1372 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1373 {
1374         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1375         unsigned int rcv_addrs, subflows;
1376         int ret;
1377
1378         spin_lock_bh(&pernet->lock);
1379         rcv_addrs = pernet->add_addr_accept_max;
1380         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1381         if (ret)
1382                 goto unlock;
1383
1384         subflows = pernet->subflows_max;
1385         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1386         if (ret)
1387                 goto unlock;
1388
1389         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1390         WRITE_ONCE(pernet->subflows_max, subflows);
1391
1392 unlock:
1393         spin_unlock_bh(&pernet->lock);
1394         return ret;
1395 }
1396
1397 static int
1398 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1399 {
1400         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1401         struct sk_buff *msg;
1402         void *reply;
1403
1404         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1405         if (!msg)
1406                 return -ENOMEM;
1407
1408         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1409                                   MPTCP_PM_CMD_GET_LIMITS);
1410         if (!reply)
1411                 goto fail;
1412
1413         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1414                         READ_ONCE(pernet->add_addr_accept_max)))
1415                 goto fail;
1416
1417         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1418                         READ_ONCE(pernet->subflows_max)))
1419                 goto fail;
1420
1421         genlmsg_end(msg, reply);
1422         return genlmsg_reply(msg, info);
1423
1424 fail:
1425         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1426         nlmsg_free(msg);
1427         return -EMSGSIZE;
1428 }
1429
1430 static int mptcp_nl_addr_backup(struct net *net,
1431                                 struct mptcp_addr_info *addr,
1432                                 u8 bkup)
1433 {
1434         long s_slot = 0, s_num = 0;
1435         struct mptcp_sock *msk;
1436         int ret = -EINVAL;
1437
1438         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1439                 struct sock *sk = (struct sock *)msk;
1440
1441                 if (list_empty(&msk->conn_list))
1442                         goto next;
1443
1444                 lock_sock(sk);
1445                 spin_lock_bh(&msk->pm.lock);
1446                 ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
1447                 spin_unlock_bh(&msk->pm.lock);
1448                 release_sock(sk);
1449
1450 next:
1451                 sock_put(sk);
1452                 cond_resched();
1453         }
1454
1455         return ret;
1456 }
1457
1458 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
1459 {
1460         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1461         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1462         struct mptcp_pm_addr_entry addr, *entry;
1463         struct net *net = sock_net(skb->sk);
1464         u8 bkup = 0;
1465         int ret;
1466
1467         ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1468         if (ret < 0)
1469                 return ret;
1470
1471         if (addr.addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1472                 bkup = 1;
1473
1474         list_for_each_entry(entry, &pernet->local_addr_list, list) {
1475                 if (addresses_equal(&entry->addr, &addr.addr, true)) {
1476                         ret = mptcp_nl_addr_backup(net, &entry->addr, bkup);
1477                         if (ret)
1478                                 return ret;
1479
1480                         if (bkup)
1481                                 entry->addr.flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
1482                         else
1483                                 entry->addr.flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
1484                 }
1485         }
1486
1487         return 0;
1488 }
1489
1490 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1491 {
1492         genlmsg_multicast_netns(&mptcp_genl_family, net,
1493                                 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1494 }
1495
1496 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1497 {
1498         const struct inet_sock *issk = inet_sk(ssk);
1499         const struct mptcp_subflow_context *sf;
1500
1501         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1502                 return -EMSGSIZE;
1503
1504         switch (ssk->sk_family) {
1505         case AF_INET:
1506                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1507                         return -EMSGSIZE;
1508                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1509                         return -EMSGSIZE;
1510                 break;
1511 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1512         case AF_INET6: {
1513                 const struct ipv6_pinfo *np = inet6_sk(ssk);
1514
1515                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1516                         return -EMSGSIZE;
1517                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1518                         return -EMSGSIZE;
1519                 break;
1520         }
1521 #endif
1522         default:
1523                 WARN_ON_ONCE(1);
1524                 return -EMSGSIZE;
1525         }
1526
1527         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1528                 return -EMSGSIZE;
1529         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
1530                 return -EMSGSIZE;
1531
1532         sf = mptcp_subflow_ctx(ssk);
1533         if (WARN_ON_ONCE(!sf))
1534                 return -EINVAL;
1535
1536         if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id))
1537                 return -EMSGSIZE;
1538
1539         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
1540                 return -EMSGSIZE;
1541
1542         return 0;
1543 }
1544
1545 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
1546                                          const struct mptcp_sock *msk,
1547                                          const struct sock *ssk)
1548 {
1549         const struct sock *sk = (const struct sock *)msk;
1550         const struct mptcp_subflow_context *sf;
1551         u8 sk_err;
1552
1553         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1554                 return -EMSGSIZE;
1555
1556         if (mptcp_event_add_subflow(skb, ssk))
1557                 return -EMSGSIZE;
1558
1559         sf = mptcp_subflow_ctx(ssk);
1560         if (WARN_ON_ONCE(!sf))
1561                 return -EINVAL;
1562
1563         if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
1564                 return -EMSGSIZE;
1565
1566         if (ssk->sk_bound_dev_if &&
1567             nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
1568                 return -EMSGSIZE;
1569
1570         sk_err = ssk->sk_err;
1571         if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
1572             nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
1573                 return -EMSGSIZE;
1574
1575         return 0;
1576 }
1577
1578 static int mptcp_event_sub_established(struct sk_buff *skb,
1579                                        const struct mptcp_sock *msk,
1580                                        const struct sock *ssk)
1581 {
1582         return mptcp_event_put_token_and_ssk(skb, msk, ssk);
1583 }
1584
1585 static int mptcp_event_sub_closed(struct sk_buff *skb,
1586                                   const struct mptcp_sock *msk,
1587                                   const struct sock *ssk)
1588 {
1589         if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
1590                 return -EMSGSIZE;
1591
1592         return 0;
1593 }
1594
1595 static int mptcp_event_created(struct sk_buff *skb,
1596                                const struct mptcp_sock *msk,
1597                                const struct sock *ssk)
1598 {
1599         int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
1600
1601         if (err)
1602                 return err;
1603
1604         return mptcp_event_add_subflow(skb, ssk);
1605 }
1606
1607 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
1608 {
1609         struct net *net = sock_net((const struct sock *)msk);
1610         struct nlmsghdr *nlh;
1611         struct sk_buff *skb;
1612
1613         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1614                 return;
1615
1616         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1617         if (!skb)
1618                 return;
1619
1620         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
1621         if (!nlh)
1622                 goto nla_put_failure;
1623
1624         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1625                 goto nla_put_failure;
1626
1627         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
1628                 goto nla_put_failure;
1629
1630         genlmsg_end(skb, nlh);
1631         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1632         return;
1633
1634 nla_put_failure:
1635         kfree_skb(skb);
1636 }
1637
1638 void mptcp_event_addr_announced(const struct mptcp_sock *msk,
1639                                 const struct mptcp_addr_info *info)
1640 {
1641         struct net *net = sock_net((const struct sock *)msk);
1642         struct nlmsghdr *nlh;
1643         struct sk_buff *skb;
1644
1645         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1646                 return;
1647
1648         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1649         if (!skb)
1650                 return;
1651
1652         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
1653                           MPTCP_EVENT_ANNOUNCED);
1654         if (!nlh)
1655                 goto nla_put_failure;
1656
1657         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1658                 goto nla_put_failure;
1659
1660         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
1661                 goto nla_put_failure;
1662
1663         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, info->port))
1664                 goto nla_put_failure;
1665
1666         switch (info->family) {
1667         case AF_INET:
1668                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
1669                         goto nla_put_failure;
1670                 break;
1671 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1672         case AF_INET6:
1673                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
1674                         goto nla_put_failure;
1675                 break;
1676 #endif
1677         default:
1678                 WARN_ON_ONCE(1);
1679                 goto nla_put_failure;
1680         }
1681
1682         genlmsg_end(skb, nlh);
1683         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1684         return;
1685
1686 nla_put_failure:
1687         kfree_skb(skb);
1688 }
1689
1690 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
1691                  const struct sock *ssk, gfp_t gfp)
1692 {
1693         struct net *net = sock_net((const struct sock *)msk);
1694         struct nlmsghdr *nlh;
1695         struct sk_buff *skb;
1696
1697         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1698                 return;
1699
1700         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
1701         if (!skb)
1702                 return;
1703
1704         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
1705         if (!nlh)
1706                 goto nla_put_failure;
1707
1708         switch (type) {
1709         case MPTCP_EVENT_UNSPEC:
1710                 WARN_ON_ONCE(1);
1711                 break;
1712         case MPTCP_EVENT_CREATED:
1713         case MPTCP_EVENT_ESTABLISHED:
1714                 if (mptcp_event_created(skb, msk, ssk) < 0)
1715                         goto nla_put_failure;
1716                 break;
1717         case MPTCP_EVENT_CLOSED:
1718                 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
1719                         goto nla_put_failure;
1720                 break;
1721         case MPTCP_EVENT_ANNOUNCED:
1722         case MPTCP_EVENT_REMOVED:
1723                 /* call mptcp_event_addr_announced()/removed instead */
1724                 WARN_ON_ONCE(1);
1725                 break;
1726         case MPTCP_EVENT_SUB_ESTABLISHED:
1727         case MPTCP_EVENT_SUB_PRIORITY:
1728                 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
1729                         goto nla_put_failure;
1730                 break;
1731         case MPTCP_EVENT_SUB_CLOSED:
1732                 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
1733                         goto nla_put_failure;
1734                 break;
1735         }
1736
1737         genlmsg_end(skb, nlh);
1738         mptcp_nl_mcast_send(net, skb, gfp);
1739         return;
1740
1741 nla_put_failure:
1742         kfree_skb(skb);
1743 }
1744
1745 static const struct genl_small_ops mptcp_pm_ops[] = {
1746         {
1747                 .cmd    = MPTCP_PM_CMD_ADD_ADDR,
1748                 .doit   = mptcp_nl_cmd_add_addr,
1749                 .flags  = GENL_ADMIN_PERM,
1750         },
1751         {
1752                 .cmd    = MPTCP_PM_CMD_DEL_ADDR,
1753                 .doit   = mptcp_nl_cmd_del_addr,
1754                 .flags  = GENL_ADMIN_PERM,
1755         },
1756         {
1757                 .cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
1758                 .doit   = mptcp_nl_cmd_flush_addrs,
1759                 .flags  = GENL_ADMIN_PERM,
1760         },
1761         {
1762                 .cmd    = MPTCP_PM_CMD_GET_ADDR,
1763                 .doit   = mptcp_nl_cmd_get_addr,
1764                 .dumpit   = mptcp_nl_cmd_dump_addrs,
1765         },
1766         {
1767                 .cmd    = MPTCP_PM_CMD_SET_LIMITS,
1768                 .doit   = mptcp_nl_cmd_set_limits,
1769                 .flags  = GENL_ADMIN_PERM,
1770         },
1771         {
1772                 .cmd    = MPTCP_PM_CMD_GET_LIMITS,
1773                 .doit   = mptcp_nl_cmd_get_limits,
1774         },
1775         {
1776                 .cmd    = MPTCP_PM_CMD_SET_FLAGS,
1777                 .doit   = mptcp_nl_cmd_set_flags,
1778                 .flags  = GENL_ADMIN_PERM,
1779         },
1780 };
1781
1782 static struct genl_family mptcp_genl_family __ro_after_init = {
1783         .name           = MPTCP_PM_NAME,
1784         .version        = MPTCP_PM_VER,
1785         .maxattr        = MPTCP_PM_ATTR_MAX,
1786         .policy         = mptcp_pm_policy,
1787         .netnsok        = true,
1788         .module         = THIS_MODULE,
1789         .small_ops      = mptcp_pm_ops,
1790         .n_small_ops    = ARRAY_SIZE(mptcp_pm_ops),
1791         .mcgrps         = mptcp_pm_mcgrps,
1792         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
1793 };
1794
1795 static int __net_init pm_nl_init_net(struct net *net)
1796 {
1797         struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1798
1799         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
1800         __reset_counters(pernet);
1801         pernet->next_id = 1;
1802         bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
1803         spin_lock_init(&pernet->lock);
1804         return 0;
1805 }
1806
1807 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
1808 {
1809         struct net *net;
1810
1811         list_for_each_entry(net, net_list, exit_list) {
1812                 struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1813
1814                 /* net is removed from namespace list, can't race with
1815                  * other modifiers
1816                  */
1817                 __flush_addrs(net, &pernet->local_addr_list);
1818         }
1819 }
1820
1821 static struct pernet_operations mptcp_pm_pernet_ops = {
1822         .init = pm_nl_init_net,
1823         .exit_batch = pm_nl_exit_net,
1824         .id = &pm_nl_pernet_id,
1825         .size = sizeof(struct pm_nl_pernet),
1826 };
1827
1828 void __init mptcp_pm_nl_init(void)
1829 {
1830         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
1831                 panic("Failed to register MPTCP PM pernet subsystem.\n");
1832
1833         if (genl_register_family(&mptcp_genl_family))
1834                 panic("Failed to register MPTCP PM netlink family\n");
1835 }