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/inet_common.h>
  12 #include <net/netns/generic.h>
  13 #include <net/mptcp.h>
  14
  15 #include "protocol.h"
  16 #include "mib.h"
  17 #include "mptcp_pm_gen.h"
  18
  19 static int pm_nl_pernet_id;
  20
  21 struct mptcp_pm_add_entry {
  22         struct list_head        list;
  23         struct mptcp_addr_info  addr;
  24         u8                      retrans_times;
  25         struct timer_list       add_timer;
  26         struct mptcp_sock       *sock;
  27 };
  28
  29 struct pm_nl_pernet {
  30         /* protects pernet updates */
  31         spinlock_t              lock;
  32         struct list_head        local_addr_list;
  33         unsigned int            addrs;
  34         unsigned int            stale_loss_cnt;
  35         unsigned int            add_addr_signal_max;
  36         unsigned int            add_addr_accept_max;
  37         unsigned int            local_addr_max;
  38         unsigned int            subflows_max;
  39         unsigned int            next_id;
  40         DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  41 };
  42
  43 #define MPTCP_PM_ADDR_MAX       8
  44 #define ADD_ADDR_RETRANS_MAX    3
  45
  46 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
  47 {
  48         return net_generic(net, pm_nl_pernet_id);
  49 }
  50
  51 static struct pm_nl_pernet *
  52 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
  53 {
  54         return pm_nl_get_pernet(sock_net((struct sock *)msk));
  55 }
  56
  57 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
  58                            const struct mptcp_addr_info *b, bool use_port)
  59 {
  60         bool addr_equals = false;
  61
  62         if (a->family == b->family) {
  63                 if (a->family == AF_INET)
  64                         addr_equals = a->addr.s_addr == b->addr.s_addr;
  65 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  66                 else
  67                         addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
  68         } else if (a->family == AF_INET) {
  69                 if (ipv6_addr_v4mapped(&b->addr6))
  70                         addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
  71         } else if (b->family == AF_INET) {
  72                 if (ipv6_addr_v4mapped(&a->addr6))
  73                         addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
  74 #endif
  75         }
  76
  77         if (!addr_equals)
  78                 return false;
  79         if (!use_port)
  80                 return true;
  81
  82         return a->port == b->port;
  83 }
  84
  85 void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr)
  86 {
  87         addr->family = skc->skc_family;
  88         addr->port = htons(skc->skc_num);
  89         if (addr->family == AF_INET)
  90                 addr->addr.s_addr = skc->skc_rcv_saddr;
  91 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  92         else if (addr->family == AF_INET6)
  93                 addr->addr6 = skc->skc_v6_rcv_saddr;
  94 #endif
  95 }
  96
  97 static void remote_address(const struct sock_common *skc,
  98                            struct mptcp_addr_info *addr)
  99 {
 100         addr->family = skc->skc_family;
 101         addr->port = skc->skc_dport;
 102         if (addr->family == AF_INET)
 103                 addr->addr.s_addr = skc->skc_daddr;
 104 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 105         else if (addr->family == AF_INET6)
 106                 addr->addr6 = skc->skc_v6_daddr;
 107 #endif
 108 }
 109
 110 static bool lookup_subflow_by_saddr(const struct list_head *list,
 111                                     const struct mptcp_addr_info *saddr)
 112 {
 113         struct mptcp_subflow_context *subflow;
 114         struct mptcp_addr_info cur;
 115         struct sock_common *skc;
 116
 117         list_for_each_entry(subflow, list, node) {
 118                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 119
 120                 mptcp_local_address(skc, &cur);
 121                 if (mptcp_addresses_equal(&cur, saddr, saddr->port))
 122                         return true;
 123         }
 124
 125         return false;
 126 }
 127
 128 static bool lookup_subflow_by_daddr(const struct list_head *list,
 129                                     const struct mptcp_addr_info *daddr)
 130 {
 131         struct mptcp_subflow_context *subflow;
 132         struct mptcp_addr_info cur;
 133
 134         list_for_each_entry(subflow, list, node) {
 135                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 136
 137                 if (!((1 << inet_sk_state_load(ssk)) &
 138                       (TCPF_ESTABLISHED | TCPF_SYN_SENT | TCPF_SYN_RECV)))
 139                         continue;
 140
 141                 remote_address((struct sock_common *)ssk, &cur);
 142                 if (mptcp_addresses_equal(&cur, daddr, daddr->port))
 143                         return true;
 144         }
 145
 146         return false;
 147 }
 148
 149 static bool
 150 select_local_address(const struct pm_nl_pernet *pernet,
 151                      const struct mptcp_sock *msk,
 152                      struct mptcp_pm_local *new_local)
 153 {
 154         struct mptcp_pm_addr_entry *entry;
 155         bool found = false;
 156
 157         msk_owned_by_me(msk);
 158
 159         rcu_read_lock();
 160         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 161                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 162                         continue;
 163
 164                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 165                         continue;
 166
 167                 new_local->addr = entry->addr;
 168                 new_local->flags = entry->flags;
 169                 new_local->ifindex = entry->ifindex;
 170                 found = true;
 171                 break;
 172         }
 173         rcu_read_unlock();
 174
 175         return found;
 176 }
 177
 178 static bool
 179 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk,
 180                      struct mptcp_pm_local *new_local)
 181 {
 182         struct mptcp_pm_addr_entry *entry;
 183         bool found = false;
 184
 185         rcu_read_lock();
 186         /* do not keep any additional per socket state, just signal
 187          * the address list in order.
 188          * Note: removal from the local address list during the msk life-cycle
 189          * can lead to additional addresses not being announced.
 190          */
 191         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 192                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 193                         continue;
 194
 195                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
 196                         continue;
 197
 198                 new_local->addr = entry->addr;
 199                 new_local->flags = entry->flags;
 200                 new_local->ifindex = entry->ifindex;
 201                 found = true;
 202                 break;
 203         }
 204         rcu_read_unlock();
 205
 206         return found;
 207 }
 208
 209 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk)
 210 {
 211         const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 212
 213         return READ_ONCE(pernet->add_addr_signal_max);
 214 }
 215 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
 216
 217 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk)
 218 {
 219         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 220
 221         return READ_ONCE(pernet->add_addr_accept_max);
 222 }
 223 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
 224
 225 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk)
 226 {
 227         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 228
 229         return READ_ONCE(pernet->subflows_max);
 230 }
 231 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
 232
 233 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk)
 234 {
 235         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 236
 237         return READ_ONCE(pernet->local_addr_max);
 238 }
 239 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
 240
 241 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 242 {
 243         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 244
 245         if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
 246             (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
 247                                MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
 248                 WRITE_ONCE(msk->pm.work_pending, false);
 249                 return false;
 250         }
 251         return true;
 252 }
 253
 254 struct mptcp_pm_add_entry *
 255 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 256                                 const struct mptcp_addr_info *addr)
 257 {
 258         struct mptcp_pm_add_entry *entry;
 259
 260         lockdep_assert_held(&msk->pm.lock);
 261
 262         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 263                 if (mptcp_addresses_equal(&entry->addr, addr, true))
 264                         return entry;
 265         }
 266
 267         return NULL;
 268 }
 269
 270 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 271 {
 272         struct mptcp_pm_add_entry *entry;
 273         struct mptcp_addr_info saddr;
 274         bool ret = false;
 275
 276         mptcp_local_address((struct sock_common *)sk, &saddr);
 277
 278         spin_lock_bh(&msk->pm.lock);
 279         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 280                 if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
 281                         ret = true;
 282                         goto out;
 283                 }
 284         }
 285
 286 out:
 287         spin_unlock_bh(&msk->pm.lock);
 288         return ret;
 289 }
 290
 291 static void mptcp_pm_add_timer(struct timer_list *timer)
 292 {
 293         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 294         struct mptcp_sock *msk = entry->sock;
 295         struct sock *sk = (struct sock *)msk;
 296
 297         pr_debug("msk=%p\n", msk);
 298
 299         if (!msk)
 300                 return;
 301
 302         if (inet_sk_state_load(sk) == TCP_CLOSE)
 303                 return;
 304
 305         if (!entry->addr.id)
 306                 return;
 307
 308         if (mptcp_pm_should_add_signal_addr(msk)) {
 309                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 310                 goto out;
 311         }
 312
 313         spin_lock_bh(&msk->pm.lock);
 314
 315         if (!mptcp_pm_should_add_signal_addr(msk)) {
 316                 pr_debug("retransmit ADD_ADDR id=%d\n", entry->addr.id);
 317                 mptcp_pm_announce_addr(msk, &entry->addr, false);
 318                 mptcp_pm_add_addr_send_ack(msk);
 319                 entry->retrans_times++;
 320         }
 321
 322         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 323                 sk_reset_timer(sk, timer,
 324                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
 325
 326         spin_unlock_bh(&msk->pm.lock);
 327
 328         if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
 329                 mptcp_pm_subflow_established(msk);
 330
 331 out:
 332         __sock_put(sk);
 333 }
 334
 335 struct mptcp_pm_add_entry *
 336 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 337                        const struct mptcp_addr_info *addr, bool check_id)
 338 {
 339         struct mptcp_pm_add_entry *entry;
 340         struct sock *sk = (struct sock *)msk;
 341         struct timer_list *add_timer = NULL;
 342
 343         spin_lock_bh(&msk->pm.lock);
 344         entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 345         if (entry && (!check_id || entry->addr.id == addr->id)) {
 346                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 347                 add_timer = &entry->add_timer;
 348         }
 349         if (!check_id && entry)
 350                 list_del(&entry->list);
 351         spin_unlock_bh(&msk->pm.lock);
 352
 353         /* no lock, because sk_stop_timer_sync() is calling del_timer_sync() */
 354         if (add_timer)
 355                 sk_stop_timer_sync(sk, add_timer);
 356
 357         return entry;
 358 }
 359
 360 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 361                               const struct mptcp_addr_info *addr)
 362 {
 363         struct mptcp_pm_add_entry *add_entry = NULL;
 364         struct sock *sk = (struct sock *)msk;
 365         struct net *net = sock_net(sk);
 366
 367         lockdep_assert_held(&msk->pm.lock);
 368
 369         add_entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 370
 371         if (add_entry) {
 372                 if (WARN_ON_ONCE(mptcp_pm_is_kernel(msk)))
 373                         return false;
 374
 375                 sk_reset_timer(sk, &add_entry->add_timer,
 376                                jiffies + mptcp_get_add_addr_timeout(net));
 377                 return true;
 378         }
 379
 380         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
 381         if (!add_entry)
 382                 return false;
 383
 384         list_add(&add_entry->list, &msk->pm.anno_list);
 385
 386         add_entry->addr = *addr;
 387         add_entry->sock = msk;
 388         add_entry->retrans_times = 0;
 389
 390         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 391         sk_reset_timer(sk, &add_entry->add_timer,
 392                        jiffies + mptcp_get_add_addr_timeout(net));
 393
 394         return true;
 395 }
 396
 397 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 398 {
 399         struct mptcp_pm_add_entry *entry, *tmp;
 400         struct sock *sk = (struct sock *)msk;
 401         LIST_HEAD(free_list);
 402
 403         pr_debug("msk=%p\n", msk);
 404
 405         spin_lock_bh(&msk->pm.lock);
 406         list_splice_init(&msk->pm.anno_list, &free_list);
 407         spin_unlock_bh(&msk->pm.lock);
 408
 409         list_for_each_entry_safe(entry, tmp, &free_list, list) {
 410                 sk_stop_timer_sync(sk, &entry->add_timer);
 411                 kfree(entry);
 412         }
 413 }
 414
 415 /* Fill all the remote addresses into the array addrs[],
 416  * and return the array size.
 417  */
 418 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk,
 419                                               struct mptcp_addr_info *local,
 420                                               bool fullmesh,
 421                                               struct mptcp_addr_info *addrs)
 422 {
 423         bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
 424         struct sock *sk = (struct sock *)msk, *ssk;
 425         struct mptcp_subflow_context *subflow;
 426         struct mptcp_addr_info remote = { 0 };
 427         unsigned int subflows_max;
 428         int i = 0;
 429
 430         subflows_max = mptcp_pm_get_subflows_max(msk);
 431         remote_address((struct sock_common *)sk, &remote);
 432
 433         /* Non-fullmesh endpoint, fill in the single entry
 434          * corresponding to the primary MPC subflow remote address
 435          */
 436         if (!fullmesh) {
 437                 if (deny_id0)
 438                         return 0;
 439
 440                 if (!mptcp_pm_addr_families_match(sk, local, &remote))
 441                         return 0;
 442
 443                 msk->pm.subflows++;
 444                 addrs[i++] = remote;
 445         } else {
 446                 DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
 447
 448                 /* Forbid creation of new subflows matching existing
 449                  * ones, possibly already created by incoming ADD_ADDR
 450                  */
 451                 bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
 452                 mptcp_for_each_subflow(msk, subflow)
 453                         if (READ_ONCE(subflow->local_id) == local->id)
 454                                 __set_bit(subflow->remote_id, unavail_id);
 455
 456                 mptcp_for_each_subflow(msk, subflow) {
 457                         ssk = mptcp_subflow_tcp_sock(subflow);
 458                         remote_address((struct sock_common *)ssk, &addrs[i]);
 459                         addrs[i].id = READ_ONCE(subflow->remote_id);
 460                         if (deny_id0 && !addrs[i].id)
 461                                 continue;
 462
 463                         if (test_bit(addrs[i].id, unavail_id))
 464                                 continue;
 465
 466                         if (!mptcp_pm_addr_families_match(sk, local, &addrs[i]))
 467                                 continue;
 468
 469                         if (msk->pm.subflows < subflows_max) {
 470                                 /* forbid creating multiple address towards
 471                                  * this id
 472                                  */
 473                                 __set_bit(addrs[i].id, unavail_id);
 474                                 msk->pm.subflows++;
 475                                 i++;
 476                         }
 477                 }
 478         }
 479
 480         return i;
 481 }
 482
 483 static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
 484                                 bool prio, bool backup)
 485 {
 486         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 487         bool slow;
 488
 489         pr_debug("send ack for %s\n",
 490                  prio ? "mp_prio" : (mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr"));
 491
 492         slow = lock_sock_fast(ssk);
 493         if (prio) {
 494                 subflow->send_mp_prio = 1;
 495                 subflow->request_bkup = backup;
 496         }
 497
 498         __mptcp_subflow_send_ack(ssk);
 499         unlock_sock_fast(ssk, slow);
 500 }
 501
 502 static void mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
 503                               bool prio, bool backup)
 504 {
 505         spin_unlock_bh(&msk->pm.lock);
 506         __mptcp_pm_send_ack(msk, subflow, prio, backup);
 507         spin_lock_bh(&msk->pm.lock);
 508 }
 509
 510 static struct mptcp_pm_addr_entry *
 511 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 512 {
 513         struct mptcp_pm_addr_entry *entry;
 514
 515         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list,
 516                                 lockdep_is_held(&pernet->lock)) {
 517                 if (entry->addr.id == id)
 518                         return entry;
 519         }
 520         return NULL;
 521 }
 522
 523 static struct mptcp_pm_addr_entry *
 524 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info)
 525 {
 526         struct mptcp_pm_addr_entry *entry;
 527
 528         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list,
 529                                 lockdep_is_held(&pernet->lock)) {
 530                 if (mptcp_addresses_equal(&entry->addr, info, entry->addr.port))
 531                         return entry;
 532         }
 533         return NULL;
 534 }
 535
 536 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 537 {
 538         struct sock *sk = (struct sock *)msk;
 539         unsigned int add_addr_signal_max;
 540         bool signal_and_subflow = false;
 541         unsigned int local_addr_max;
 542         struct pm_nl_pernet *pernet;
 543         struct mptcp_pm_local local;
 544         unsigned int subflows_max;
 545
 546         pernet = pm_nl_get_pernet(sock_net(sk));
 547
 548         add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
 549         local_addr_max = mptcp_pm_get_local_addr_max(msk);
 550         subflows_max = mptcp_pm_get_subflows_max(msk);
 551
 552         /* do lazy endpoint usage accounting for the MPC subflows */
 553         if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
 554                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
 555                 struct mptcp_pm_addr_entry *entry;
 556                 struct mptcp_addr_info mpc_addr;
 557                 bool backup = false;
 558
 559                 mptcp_local_address((struct sock_common *)msk->first, &mpc_addr);
 560                 rcu_read_lock();
 561                 entry = __lookup_addr(pernet, &mpc_addr);
 562                 if (entry) {
 563                         __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap);
 564                         msk->mpc_endpoint_id = entry->addr.id;
 565                         backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 566                 }
 567                 rcu_read_unlock();
 568
 569                 if (backup)
 570                         mptcp_pm_send_ack(msk, subflow, true, backup);
 571
 572                 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
 573         }
 574
 575         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
 576                  msk->pm.local_addr_used, local_addr_max,
 577                  msk->pm.add_addr_signaled, add_addr_signal_max,
 578                  msk->pm.subflows, subflows_max);
 579
 580         /* check first for announce */
 581         if (msk->pm.add_addr_signaled < add_addr_signal_max) {
 582                 /* due to racing events on both ends we can reach here while
 583                  * previous add address is still running: if we invoke now
 584                  * mptcp_pm_announce_addr(), that will fail and the
 585                  * corresponding id will be marked as used.
 586                  * Instead let the PM machinery reschedule us when the
 587                  * current address announce will be completed.
 588                  */
 589                 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
 590                         return;
 591
 592                 if (!select_signal_address(pernet, msk, &local))
 593                         goto subflow;
 594
 595                 /* If the alloc fails, we are on memory pressure, not worth
 596                  * continuing, and trying to create subflows.
 597                  */
 598                 if (!mptcp_pm_alloc_anno_list(msk, &local.addr))
 599                         return;
 600
 601                 __clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
 602                 msk->pm.add_addr_signaled++;
 603
 604                 /* Special case for ID0: set the correct ID */
 605                 if (local.addr.id == msk->mpc_endpoint_id)
 606                         local.addr.id = 0;
 607
 608                 mptcp_pm_announce_addr(msk, &local.addr, false);
 609                 mptcp_pm_nl_addr_send_ack(msk);
 610
 611                 if (local.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
 612                         signal_and_subflow = true;
 613         }
 614
 615 subflow:
 616         /* check if should create a new subflow */
 617         while (msk->pm.local_addr_used < local_addr_max &&
 618                msk->pm.subflows < subflows_max) {
 619                 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 620                 bool fullmesh;
 621                 int i, nr;
 622
 623                 if (signal_and_subflow)
 624                         signal_and_subflow = false;
 625                 else if (!select_local_address(pernet, msk, &local))
 626                         break;
 627
 628                 fullmesh = !!(local.flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
 629
 630                 __clear_bit(local.addr.id, msk->pm.id_avail_bitmap);
 631
 632                 /* Special case for ID0: set the correct ID */
 633                 if (local.addr.id == msk->mpc_endpoint_id)
 634                         local.addr.id = 0;
 635                 else /* local_addr_used is not decr for ID 0 */
 636                         msk->pm.local_addr_used++;
 637
 638                 nr = fill_remote_addresses_vec(msk, &local.addr, fullmesh, addrs);
 639                 if (nr == 0)
 640                         continue;
 641
 642                 spin_unlock_bh(&msk->pm.lock);
 643                 for (i = 0; i < nr; i++)
 644                         __mptcp_subflow_connect(sk, &local, &addrs[i]);
 645                 spin_lock_bh(&msk->pm.lock);
 646         }
 647         mptcp_pm_nl_check_work_pending(msk);
 648 }
 649
 650 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 651 {
 652         mptcp_pm_create_subflow_or_signal_addr(msk);
 653 }
 654
 655 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 656 {
 657         mptcp_pm_create_subflow_or_signal_addr(msk);
 658 }
 659
 660 /* Fill all the local addresses into the array addrs[],
 661  * and return the array size.
 662  */
 663 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
 664                                              struct mptcp_addr_info *remote,
 665                                              struct mptcp_pm_local *locals)
 666 {
 667         struct sock *sk = (struct sock *)msk;
 668         struct mptcp_pm_addr_entry *entry;
 669         struct mptcp_addr_info mpc_addr;
 670         struct pm_nl_pernet *pernet;
 671         unsigned int subflows_max;
 672         int i = 0;
 673
 674         pernet = pm_nl_get_pernet_from_msk(msk);
 675         subflows_max = mptcp_pm_get_subflows_max(msk);
 676
 677         mptcp_local_address((struct sock_common *)msk, &mpc_addr);
 678
 679         rcu_read_lock();
 680         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 681                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
 682                         continue;
 683
 684                 if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote))
 685                         continue;
 686
 687                 if (msk->pm.subflows < subflows_max) {
 688                         locals[i].addr = entry->addr;
 689                         locals[i].flags = entry->flags;
 690                         locals[i].ifindex = entry->ifindex;
 691
 692                         /* Special case for ID0: set the correct ID */
 693                         if (mptcp_addresses_equal(&locals[i].addr, &mpc_addr, locals[i].addr.port))
 694                                 locals[i].addr.id = 0;
 695
 696                         msk->pm.subflows++;
 697                         i++;
 698                 }
 699         }
 700         rcu_read_unlock();
 701
 702         /* If the array is empty, fill in the single
 703          * 'IPADDRANY' local address
 704          */
 705         if (!i) {
 706                 memset(&locals[i], 0, sizeof(locals[i]));
 707                 locals[i].addr.family =
 708 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 709                                remote->family == AF_INET6 &&
 710                                ipv6_addr_v4mapped(&remote->addr6) ? AF_INET :
 711 #endif
 712                                remote->family;
 713
 714                 if (!mptcp_pm_addr_families_match(sk, &locals[i].addr, remote))
 715                         return 0;
 716
 717                 msk->pm.subflows++;
 718                 i++;
 719         }
 720
 721         return i;
 722 }
 723
 724 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 725 {
 726         struct mptcp_pm_local locals[MPTCP_PM_ADDR_MAX];
 727         struct sock *sk = (struct sock *)msk;
 728         unsigned int add_addr_accept_max;
 729         struct mptcp_addr_info remote;
 730         unsigned int subflows_max;
 731         bool sf_created = false;
 732         int i, nr;
 733
 734         add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
 735         subflows_max = mptcp_pm_get_subflows_max(msk);
 736
 737         pr_debug("accepted %d:%d remote family %d\n",
 738                  msk->pm.add_addr_accepted, add_addr_accept_max,
 739                  msk->pm.remote.family);
 740
 741         remote = msk->pm.remote;
 742         mptcp_pm_announce_addr(msk, &remote, true);
 743         mptcp_pm_nl_addr_send_ack(msk);
 744
 745         if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
 746                 return;
 747
 748         /* pick id 0 port, if none is provided the remote address */
 749         if (!remote.port)
 750                 remote.port = sk->sk_dport;
 751
 752         /* connect to the specified remote address, using whatever
 753          * local address the routing configuration will pick.
 754          */
 755         nr = fill_local_addresses_vec(msk, &remote, locals);
 756         if (nr == 0)
 757                 return;
 758
 759         spin_unlock_bh(&msk->pm.lock);
 760         for (i = 0; i < nr; i++)
 761                 if (__mptcp_subflow_connect(sk, &locals[i], &remote) == 0)
 762                         sf_created = true;
 763         spin_lock_bh(&msk->pm.lock);
 764
 765         if (sf_created) {
 766                 /* add_addr_accepted is not decr for ID 0 */
 767                 if (remote.id)
 768                         msk->pm.add_addr_accepted++;
 769                 if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
 770                     msk->pm.subflows >= subflows_max)
 771                         WRITE_ONCE(msk->pm.accept_addr, false);
 772         }
 773 }
 774
 775 bool mptcp_pm_nl_is_init_remote_addr(struct mptcp_sock *msk,
 776                                      const struct mptcp_addr_info *remote)
 777 {
 778         struct mptcp_addr_info mpc_remote;
 779
 780         remote_address((struct sock_common *)msk, &mpc_remote);
 781         return mptcp_addresses_equal(&mpc_remote, remote, remote->port);
 782 }
 783
 784 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
 785 {
 786         struct mptcp_subflow_context *subflow, *alt = NULL;
 787
 788         msk_owned_by_me(msk);
 789         lockdep_assert_held(&msk->pm.lock);
 790
 791         if (!mptcp_pm_should_add_signal(msk) &&
 792             !mptcp_pm_should_rm_signal(msk))
 793                 return;
 794
 795         mptcp_for_each_subflow(msk, subflow) {
 796                 if (__mptcp_subflow_active(subflow)) {
 797                         if (!subflow->stale) {
 798                                 mptcp_pm_send_ack(msk, subflow, false, false);
 799                                 return;
 800                         }
 801
 802                         if (!alt)
 803                                 alt = subflow;
 804                 }
 805         }
 806
 807         if (alt)
 808                 mptcp_pm_send_ack(msk, alt, false, false);
 809 }
 810
 811 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 812                                  struct mptcp_addr_info *addr,
 813                                  struct mptcp_addr_info *rem,
 814                                  u8 bkup)
 815 {
 816         struct mptcp_subflow_context *subflow;
 817
 818         pr_debug("bkup=%d\n", bkup);
 819
 820         mptcp_for_each_subflow(msk, subflow) {
 821                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 822                 struct mptcp_addr_info local, remote;
 823
 824                 mptcp_local_address((struct sock_common *)ssk, &local);
 825                 if (!mptcp_addresses_equal(&local, addr, addr->port))
 826                         continue;
 827
 828                 if (rem && rem->family != AF_UNSPEC) {
 829                         remote_address((struct sock_common *)ssk, &remote);
 830                         if (!mptcp_addresses_equal(&remote, rem, rem->port))
 831                                 continue;
 832                 }
 833
 834                 __mptcp_pm_send_ack(msk, subflow, true, bkup);
 835                 return 0;
 836         }
 837
 838         return -EINVAL;
 839 }
 840
 841 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 842                                            const struct mptcp_rm_list *rm_list,
 843                                            enum linux_mptcp_mib_field rm_type)
 844 {
 845         struct mptcp_subflow_context *subflow, *tmp;
 846         struct sock *sk = (struct sock *)msk;
 847         u8 i;
 848
 849         pr_debug("%s rm_list_nr %d\n",
 850                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
 851
 852         msk_owned_by_me(msk);
 853
 854         if (sk->sk_state == TCP_LISTEN)
 855                 return;
 856
 857         if (!rm_list->nr)
 858                 return;
 859
 860         if (list_empty(&msk->conn_list))
 861                 return;
 862
 863         for (i = 0; i < rm_list->nr; i++) {
 864                 u8 rm_id = rm_list->ids[i];
 865                 bool removed = false;
 866
 867                 mptcp_for_each_subflow_safe(msk, subflow, tmp) {
 868                         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 869                         u8 remote_id = READ_ONCE(subflow->remote_id);
 870                         int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 871                         u8 id = subflow_get_local_id(subflow);
 872
 873                         if ((1 << inet_sk_state_load(ssk)) &
 874                             (TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSING | TCPF_CLOSE))
 875                                 continue;
 876                         if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
 877                                 continue;
 878                         if (rm_type == MPTCP_MIB_RMSUBFLOW && id != rm_id)
 879                                 continue;
 880
 881                         pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u\n",
 882                                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
 883                                  i, rm_id, id, remote_id, msk->mpc_endpoint_id);
 884                         spin_unlock_bh(&msk->pm.lock);
 885                         mptcp_subflow_shutdown(sk, ssk, how);
 886                         removed |= subflow->request_join;
 887
 888                         /* the following takes care of updating the subflows counter */
 889                         mptcp_close_ssk(sk, ssk, subflow);
 890                         spin_lock_bh(&msk->pm.lock);
 891
 892                         if (rm_type == MPTCP_MIB_RMSUBFLOW)
 893                                 __MPTCP_INC_STATS(sock_net(sk), rm_type);
 894                 }
 895
 896                 if (rm_type == MPTCP_MIB_RMADDR)
 897                         __MPTCP_INC_STATS(sock_net(sk), rm_type);
 898
 899                 if (!removed)
 900                         continue;
 901
 902                 if (!mptcp_pm_is_kernel(msk))
 903                         continue;
 904
 905                 if (rm_type == MPTCP_MIB_RMADDR && rm_id &&
 906                     !WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)) {
 907                         /* Note: if the subflow has been closed before, this
 908                          * add_addr_accepted counter will not be decremented.
 909                          */
 910                         if (--msk->pm.add_addr_accepted < mptcp_pm_get_add_addr_accept_max(msk))
 911                                 WRITE_ONCE(msk->pm.accept_addr, true);
 912                 }
 913         }
 914 }
 915
 916 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
 917 {
 918         mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
 919 }
 920
 921 static void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 922                                             const struct mptcp_rm_list *rm_list)
 923 {
 924         mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
 925 }
 926
 927 void mptcp_pm_nl_work(struct mptcp_sock *msk)
 928 {
 929         struct mptcp_pm_data *pm = &msk->pm;
 930
 931         msk_owned_by_me(msk);
 932
 933         if (!(pm->status & MPTCP_PM_WORK_MASK))
 934                 return;
 935
 936         spin_lock_bh(&msk->pm.lock);
 937
 938         pr_debug("msk=%p status=%x\n", msk, pm->status);
 939         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
 940                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 941                 mptcp_pm_nl_add_addr_received(msk);
 942         }
 943         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 944                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
 945                 mptcp_pm_nl_addr_send_ack(msk);
 946         }
 947         if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
 948                 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
 949                 mptcp_pm_nl_rm_addr_received(msk);
 950         }
 951         if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
 952                 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 953                 mptcp_pm_nl_fully_established(msk);
 954         }
 955         if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
 956                 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
 957                 mptcp_pm_nl_subflow_established(msk);
 958         }
 959
 960         spin_unlock_bh(&msk->pm.lock);
 961 }
 962
 963 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
 964 {
 965         return (entry->flags &
 966                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
 967                 MPTCP_PM_ADDR_FLAG_SIGNAL;
 968 }
 969
 970 /* caller must ensure the RCU grace period is already elapsed */
 971 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
 972 {
 973         if (entry->lsk)
 974                 sock_release(entry->lsk);
 975         kfree(entry);
 976 }
 977
 978 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 979                                              struct mptcp_pm_addr_entry *entry,
 980                                              bool needs_id)
 981 {
 982         struct mptcp_pm_addr_entry *cur, *del_entry = NULL;
 983         unsigned int addr_max;
 984         int ret = -EINVAL;
 985
 986         spin_lock_bh(&pernet->lock);
 987         /* to keep the code simple, don't do IDR-like allocation for address ID,
 988          * just bail when we exceed limits
 989          */
 990         if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
 991                 pernet->next_id = 1;
 992         if (pernet->addrs >= MPTCP_PM_ADDR_MAX) {
 993                 ret = -ERANGE;
 994                 goto out;
 995         }
 996         if (test_bit(entry->addr.id, pernet->id_bitmap)) {
 997                 ret = -EBUSY;
 998                 goto out;
 999         }
1000
1001         /* do not insert duplicate address, differentiate on port only
1002          * singled addresses
1003          */
1004         if (!address_use_port(entry))
1005                 entry->addr.port = 0;
1006         list_for_each_entry(cur, &pernet->local_addr_list, list) {
1007                 if (mptcp_addresses_equal(&cur->addr, &entry->addr,
1008                                           cur->addr.port || entry->addr.port)) {
1009                         /* allow replacing the exiting endpoint only if such
1010                          * endpoint is an implicit one and the user-space
1011                          * did not provide an endpoint id
1012                          */
1013                         if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) {
1014                                 ret = -EEXIST;
1015                                 goto out;
1016                         }
1017                         if (entry->addr.id)
1018                                 goto out;
1019
1020                         pernet->addrs--;
1021                         entry->addr.id = cur->addr.id;
1022                         list_del_rcu(&cur->list);
1023                         del_entry = cur;
1024                         break;
1025                 }
1026         }
1027
1028         if (!entry->addr.id && needs_id) {
1029 find_next:
1030                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
1031                                                     MPTCP_PM_MAX_ADDR_ID + 1,
1032                                                     pernet->next_id);
1033                 if (!entry->addr.id && pernet->next_id != 1) {
1034                         pernet->next_id = 1;
1035                         goto find_next;
1036                 }
1037         }
1038
1039         if (!entry->addr.id && needs_id)
1040                 goto out;
1041
1042         __set_bit(entry->addr.id, pernet->id_bitmap);
1043         if (entry->addr.id > pernet->next_id)
1044                 pernet->next_id = entry->addr.id;
1045
1046         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1047                 addr_max = pernet->add_addr_signal_max;
1048                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
1049         }
1050         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1051                 addr_max = pernet->local_addr_max;
1052                 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
1053         }
1054
1055         pernet->addrs++;
1056         if (!entry->addr.port)
1057                 list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
1058         else
1059                 list_add_rcu(&entry->list, &pernet->local_addr_list);
1060         ret = entry->addr.id;
1061
1062 out:
1063         spin_unlock_bh(&pernet->lock);
1064
1065         /* just replaced an existing entry, free it */
1066         if (del_entry) {
1067                 synchronize_rcu();
1068                 __mptcp_pm_release_addr_entry(del_entry);
1069         }
1070         return ret;
1071 }
1072
1073 static struct lock_class_key mptcp_slock_keys[2];
1074 static struct lock_class_key mptcp_keys[2];
1075
1076 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
1077                                             struct mptcp_pm_addr_entry *entry)
1078 {
1079         bool is_ipv6 = sk->sk_family == AF_INET6;
1080         int addrlen = sizeof(struct sockaddr_in);
1081         struct sockaddr_storage addr;
1082         struct sock *newsk, *ssk;
1083         int backlog = 1024;
1084         int err;
1085
1086         err = sock_create_kern(sock_net(sk), entry->addr.family,
1087                                SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
1088         if (err)
1089                 return err;
1090
1091         newsk = entry->lsk->sk;
1092         if (!newsk)
1093                 return -EINVAL;
1094
1095         /* The subflow socket lock is acquired in a nested to the msk one
1096          * in several places, even by the TCP stack, and this msk is a kernel
1097          * socket: lockdep complains. Instead of propagating the _nested
1098          * modifiers in several places, re-init the lock class for the msk
1099          * socket to an mptcp specific one.
1100          */
1101         sock_lock_init_class_and_name(newsk,
1102                                       is_ipv6 ? "mlock-AF_INET6" : "mlock-AF_INET",
1103                                       &mptcp_slock_keys[is_ipv6],
1104                                       is_ipv6 ? "msk_lock-AF_INET6" : "msk_lock-AF_INET",
1105                                       &mptcp_keys[is_ipv6]);
1106
1107         lock_sock(newsk);
1108         ssk = __mptcp_nmpc_sk(mptcp_sk(newsk));
1109         release_sock(newsk);
1110         if (IS_ERR(ssk))
1111                 return PTR_ERR(ssk);
1112
1113         mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
1114 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1115         if (entry->addr.family == AF_INET6)
1116                 addrlen = sizeof(struct sockaddr_in6);
1117 #endif
1118         if (ssk->sk_family == AF_INET)
1119                 err = inet_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1120 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1121         else if (ssk->sk_family == AF_INET6)
1122                 err = inet6_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1123 #endif
1124         if (err)
1125                 return err;
1126
1127         /* We don't use mptcp_set_state() here because it needs to be called
1128          * under the msk socket lock. For the moment, that will not bring
1129          * anything more than only calling inet_sk_state_store(), because the
1130          * old status is known (TCP_CLOSE).
1131          */
1132         inet_sk_state_store(newsk, TCP_LISTEN);
1133         lock_sock(ssk);
1134         WRITE_ONCE(mptcp_subflow_ctx(ssk)->pm_listener, true);
1135         err = __inet_listen_sk(ssk, backlog);
1136         if (!err)
1137                 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED);
1138         release_sock(ssk);
1139         return err;
1140 }
1141
1142 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1143 {
1144         struct mptcp_pm_addr_entry *entry;
1145         struct pm_nl_pernet *pernet;
1146         int ret;
1147
1148         pernet = pm_nl_get_pernet_from_msk(msk);
1149
1150         rcu_read_lock();
1151         entry = __lookup_addr(pernet, skc);
1152         ret = entry ? entry->addr.id : -1;
1153         rcu_read_unlock();
1154         if (ret >= 0)
1155                 return ret;
1156
1157         /* address not found, add to local list */
1158         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1159         if (!entry)
1160                 return -ENOMEM;
1161
1162         entry->addr = *skc;
1163         entry->addr.id = 0;
1164         entry->addr.port = 0;
1165         entry->ifindex = 0;
1166         entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
1167         entry->lsk = NULL;
1168         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
1169         if (ret < 0)
1170                 kfree(entry);
1171
1172         return ret;
1173 }
1174
1175 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1176 {
1177         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
1178         struct mptcp_pm_addr_entry *entry;
1179         bool backup;
1180
1181         rcu_read_lock();
1182         entry = __lookup_addr(pernet, skc);
1183         backup = entry && !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
1184         rcu_read_unlock();
1185
1186         return backup;
1187 }
1188
1189 #define MPTCP_PM_CMD_GRP_OFFSET       0
1190 #define MPTCP_PM_EV_GRP_OFFSET        1
1191
1192 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1193         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
1194         [MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
1195                                             .flags = GENL_MCAST_CAP_NET_ADMIN,
1196                                           },
1197 };
1198
1199 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1200 {
1201         struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1202         struct sock *sk = (struct sock *)msk;
1203         unsigned int active_max_loss_cnt;
1204         struct net *net = sock_net(sk);
1205         unsigned int stale_loss_cnt;
1206         bool slow;
1207
1208         stale_loss_cnt = mptcp_stale_loss_cnt(net);
1209         if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1210                 return;
1211
1212         /* look for another available subflow not in loss state */
1213         active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1214         mptcp_for_each_subflow(msk, iter) {
1215                 if (iter != subflow && mptcp_subflow_active(iter) &&
1216                     iter->stale_count < active_max_loss_cnt) {
1217                         /* we have some alternatives, try to mark this subflow as idle ...*/
1218                         slow = lock_sock_fast(ssk);
1219                         if (!tcp_rtx_and_write_queues_empty(ssk)) {
1220                                 subflow->stale = 1;
1221                                 __mptcp_retransmit_pending_data(sk);
1222                                 MPTCP_INC_STATS(net, MPTCP_MIB_SUBFLOWSTALE);
1223                         }
1224                         unlock_sock_fast(ssk, slow);
1225
1226                         /* always try to push the pending data regardless of re-injections:
1227                          * we can possibly use backup subflows now, and subflow selection
1228                          * is cheap under the msk socket lock
1229                          */
1230                         __mptcp_push_pending(sk, 0);
1231                         return;
1232                 }
1233         }
1234 }
1235
1236 static int mptcp_pm_family_to_addr(int family)
1237 {
1238 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1239         if (family == AF_INET6)
1240                 return MPTCP_PM_ADDR_ATTR_ADDR6;
1241 #endif
1242         return MPTCP_PM_ADDR_ATTR_ADDR4;
1243 }
1244
1245 static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
1246                                        const struct nlattr *attr,
1247                                        struct genl_info *info,
1248                                        struct mptcp_addr_info *addr,
1249                                        bool require_family)
1250 {
1251         int err, addr_addr;
1252
1253         if (!attr) {
1254                 GENL_SET_ERR_MSG(info, "missing address info");
1255                 return -EINVAL;
1256         }
1257
1258         /* no validation needed - was already done via nested policy */
1259         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1260                                           mptcp_pm_address_nl_policy, info->extack);
1261         if (err)
1262                 return err;
1263
1264         if (tb[MPTCP_PM_ADDR_ATTR_ID])
1265                 addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1266
1267         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1268                 if (!require_family)
1269                         return 0;
1270
1271                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1272                                     "missing family");
1273                 return -EINVAL;
1274         }
1275
1276         addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1277         if (addr->family != AF_INET
1278 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1279             && addr->family != AF_INET6
1280 #endif
1281             ) {
1282                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1283                                     "unknown address family");
1284                 return -EINVAL;
1285         }
1286         addr_addr = mptcp_pm_family_to_addr(addr->family);
1287         if (!tb[addr_addr]) {
1288                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1289                                     "missing address data");
1290                 return -EINVAL;
1291         }
1292
1293 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1294         if (addr->family == AF_INET6)
1295                 addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
1296         else
1297 #endif
1298                 addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1299
1300         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1301                 addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1302
1303         return 0;
1304 }
1305
1306 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1307                         struct mptcp_addr_info *addr)
1308 {
1309         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1310
1311         memset(addr, 0, sizeof(*addr));
1312
1313         return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
1314 }
1315
1316 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1317                          bool require_family,
1318                          struct mptcp_pm_addr_entry *entry)
1319 {
1320         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1321         int err;
1322
1323         memset(entry, 0, sizeof(*entry));
1324
1325         err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
1326         if (err)
1327                 return err;
1328
1329         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1330                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1331
1332                 entry->ifindex = val;
1333         }
1334
1335         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1336                 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1337
1338         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1339                 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1340
1341         return 0;
1342 }
1343
1344 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1345 {
1346         return pm_nl_get_pernet(genl_info_net(info));
1347 }
1348
1349 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net,
1350                                                struct mptcp_addr_info *addr)
1351 {
1352         struct mptcp_sock *msk;
1353         long s_slot = 0, s_num = 0;
1354
1355         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1356                 struct sock *sk = (struct sock *)msk;
1357                 struct mptcp_addr_info mpc_addr;
1358
1359                 if (!READ_ONCE(msk->fully_established) ||
1360                     mptcp_pm_is_userspace(msk))
1361                         goto next;
1362
1363                 /* if the endp linked to the init sf is re-added with a != ID */
1364                 mptcp_local_address((struct sock_common *)msk, &mpc_addr);
1365
1366                 lock_sock(sk);
1367                 spin_lock_bh(&msk->pm.lock);
1368                 if (mptcp_addresses_equal(addr, &mpc_addr, addr->port))
1369                         msk->mpc_endpoint_id = addr->id;
1370                 mptcp_pm_create_subflow_or_signal_addr(msk);
1371                 spin_unlock_bh(&msk->pm.lock);
1372                 release_sock(sk);
1373
1374 next:
1375                 sock_put(sk);
1376                 cond_resched();
1377         }
1378
1379         return 0;
1380 }
1381
1382 static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr,
1383                                       struct genl_info *info)
1384 {
1385         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1386
1387         if (!nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1388                                          mptcp_pm_address_nl_policy, info->extack) &&
1389             tb[MPTCP_PM_ADDR_ATTR_ID])
1390                 return true;
1391         return false;
1392 }
1393
1394 int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
1395 {
1396         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1397         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1398         struct mptcp_pm_addr_entry addr, *entry;
1399         int ret;
1400
1401         ret = mptcp_pm_parse_entry(attr, info, true, &addr);
1402         if (ret < 0)
1403                 return ret;
1404
1405         if (addr.addr.port && !address_use_port(&addr)) {
1406                 GENL_SET_ERR_MSG(info, "flags must have signal and not subflow when using port");
1407                 return -EINVAL;
1408         }
1409
1410         if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
1411             addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
1412                 GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
1413                 return -EINVAL;
1414         }
1415
1416         if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
1417                 GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
1418                 return -EINVAL;
1419         }
1420
1421         entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
1422         if (!entry) {
1423                 GENL_SET_ERR_MSG(info, "can't allocate addr");
1424                 return -ENOMEM;
1425         }
1426
1427         *entry = addr;
1428         if (entry->addr.port) {
1429                 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1430                 if (ret) {
1431                         GENL_SET_ERR_MSG_FMT(info, "create listen socket error: %d", ret);
1432                         goto out_free;
1433                 }
1434         }
1435         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry,
1436                                                 !mptcp_pm_has_addr_attr_id(attr, info));
1437         if (ret < 0) {
1438                 GENL_SET_ERR_MSG_FMT(info, "too many addresses or duplicate one: %d", ret);
1439                 goto out_free;
1440         }
1441
1442         mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk), &entry->addr);
1443         return 0;
1444
1445 out_free:
1446         __mptcp_pm_release_addr_entry(entry);
1447         return ret;
1448 }
1449
1450 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1451                                       const struct mptcp_addr_info *addr)
1452 {
1453         struct mptcp_pm_add_entry *entry;
1454
1455         entry = mptcp_pm_del_add_timer(msk, addr, false);
1456         if (entry) {
1457                 kfree(entry);
1458                 return true;
1459         }
1460
1461         return false;
1462 }
1463
1464 static u8 mptcp_endp_get_local_id(struct mptcp_sock *msk,
1465                                   const struct mptcp_addr_info *addr)
1466 {
1467         return msk->mpc_endpoint_id == addr->id ? 0 : addr->id;
1468 }
1469
1470 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1471                                       const struct mptcp_addr_info *addr,
1472                                       bool force)
1473 {
1474         struct mptcp_rm_list list = { .nr = 0 };
1475         bool ret;
1476
1477         list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr);
1478
1479         ret = remove_anno_list_by_saddr(msk, addr);
1480         if (ret || force) {
1481                 spin_lock_bh(&msk->pm.lock);
1482                 if (ret) {
1483                         __set_bit(addr->id, msk->pm.id_avail_bitmap);
1484                         msk->pm.add_addr_signaled--;
1485                 }
1486                 mptcp_pm_remove_addr(msk, &list);
1487                 spin_unlock_bh(&msk->pm.lock);
1488         }
1489         return ret;
1490 }
1491
1492 static void __mark_subflow_endp_available(struct mptcp_sock *msk, u8 id)
1493 {
1494         /* If it was marked as used, and not ID 0, decrement local_addr_used */
1495         if (!__test_and_set_bit(id ? : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap) &&
1496             id && !WARN_ON_ONCE(msk->pm.local_addr_used == 0))
1497                 msk->pm.local_addr_used--;
1498 }
1499
1500 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1501                                                    const struct mptcp_pm_addr_entry *entry)
1502 {
1503         const struct mptcp_addr_info *addr = &entry->addr;
1504         struct mptcp_rm_list list = { .nr = 1 };
1505         long s_slot = 0, s_num = 0;
1506         struct mptcp_sock *msk;
1507
1508         pr_debug("remove_id=%d\n", addr->id);
1509
1510         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1511                 struct sock *sk = (struct sock *)msk;
1512                 bool remove_subflow;
1513
1514                 if (mptcp_pm_is_userspace(msk))
1515                         goto next;
1516
1517                 if (list_empty(&msk->conn_list)) {
1518                         mptcp_pm_remove_anno_addr(msk, addr, false);
1519                         goto next;
1520                 }
1521
1522                 lock_sock(sk);
1523                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1524                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
1525                                           !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
1526
1527                 list.ids[0] = mptcp_endp_get_local_id(msk, addr);
1528                 if (remove_subflow) {
1529                         spin_lock_bh(&msk->pm.lock);
1530                         mptcp_pm_nl_rm_subflow_received(msk, &list);
1531                         spin_unlock_bh(&msk->pm.lock);
1532                 }
1533
1534                 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1535                         spin_lock_bh(&msk->pm.lock);
1536                         __mark_subflow_endp_available(msk, list.ids[0]);
1537                         spin_unlock_bh(&msk->pm.lock);
1538                 }
1539
1540                 if (msk->mpc_endpoint_id == entry->addr.id)
1541                         msk->mpc_endpoint_id = 0;
1542                 release_sock(sk);
1543
1544 next:
1545                 sock_put(sk);
1546                 cond_resched();
1547         }
1548
1549         return 0;
1550 }
1551
1552 static int mptcp_nl_remove_id_zero_address(struct net *net,
1553                                            struct mptcp_addr_info *addr)
1554 {
1555         struct mptcp_rm_list list = { .nr = 0 };
1556         long s_slot = 0, s_num = 0;
1557         struct mptcp_sock *msk;
1558
1559         list.ids[list.nr++] = 0;
1560
1561         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1562                 struct sock *sk = (struct sock *)msk;
1563                 struct mptcp_addr_info msk_local;
1564
1565                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1566                         goto next;
1567
1568                 mptcp_local_address((struct sock_common *)msk, &msk_local);
1569                 if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
1570                         goto next;
1571
1572                 lock_sock(sk);
1573                 spin_lock_bh(&msk->pm.lock);
1574                 mptcp_pm_remove_addr(msk, &list);
1575                 mptcp_pm_nl_rm_subflow_received(msk, &list);
1576                 __mark_subflow_endp_available(msk, 0);
1577                 spin_unlock_bh(&msk->pm.lock);
1578                 release_sock(sk);
1579
1580 next:
1581                 sock_put(sk);
1582                 cond_resched();
1583         }
1584
1585         return 0;
1586 }
1587
1588 int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info)
1589 {
1590         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1591         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1592         struct mptcp_pm_addr_entry addr, *entry;
1593         unsigned int addr_max;
1594         int ret;
1595
1596         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1597         if (ret < 0)
1598                 return ret;
1599
1600         /* the zero id address is special: the first address used by the msk
1601          * always gets such an id, so different subflows can have different zero
1602          * id addresses. Additionally zero id is not accounted for in id_bitmap.
1603          * Let's use an 'mptcp_rm_list' instead of the common remove code.
1604          */
1605         if (addr.addr.id == 0)
1606                 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1607
1608         spin_lock_bh(&pernet->lock);
1609         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1610         if (!entry) {
1611                 GENL_SET_ERR_MSG(info, "address not found");
1612                 spin_unlock_bh(&pernet->lock);
1613                 return -EINVAL;
1614         }
1615         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1616                 addr_max = pernet->add_addr_signal_max;
1617                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1618         }
1619         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1620                 addr_max = pernet->local_addr_max;
1621                 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1622         }
1623
1624         pernet->addrs--;
1625         list_del_rcu(&entry->list);
1626         __clear_bit(entry->addr.id, pernet->id_bitmap);
1627         spin_unlock_bh(&pernet->lock);
1628
1629         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry);
1630         synchronize_rcu();
1631         __mptcp_pm_release_addr_entry(entry);
1632
1633         return ret;
1634 }
1635
1636 /* Called from the userspace PM only */
1637 void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
1638 {
1639         struct mptcp_rm_list alist = { .nr = 0 };
1640         struct mptcp_pm_addr_entry *entry;
1641         int anno_nr = 0;
1642
1643         list_for_each_entry(entry, rm_list, list) {
1644                 if (alist.nr >= MPTCP_RM_IDS_MAX)
1645                         break;
1646
1647                 /* only delete if either announced or matching a subflow */
1648                 if (remove_anno_list_by_saddr(msk, &entry->addr))
1649                         anno_nr++;
1650                 else if (!lookup_subflow_by_saddr(&msk->conn_list,
1651                                                   &entry->addr))
1652                         continue;
1653
1654                 alist.ids[alist.nr++] = entry->addr.id;
1655         }
1656
1657         if (alist.nr) {
1658                 spin_lock_bh(&msk->pm.lock);
1659                 msk->pm.add_addr_signaled -= anno_nr;
1660                 mptcp_pm_remove_addr(msk, &alist);
1661                 spin_unlock_bh(&msk->pm.lock);
1662         }
1663 }
1664
1665 /* Called from the in-kernel PM only */
1666 static void mptcp_pm_flush_addrs_and_subflows(struct mptcp_sock *msk,
1667                                               struct list_head *rm_list)
1668 {
1669         struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1670         struct mptcp_pm_addr_entry *entry;
1671
1672         list_for_each_entry(entry, rm_list, list) {
1673                 if (slist.nr < MPTCP_RM_IDS_MAX &&
1674                     lookup_subflow_by_saddr(&msk->conn_list, &entry->addr))
1675                         slist.ids[slist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
1676
1677                 if (alist.nr < MPTCP_RM_IDS_MAX &&
1678                     remove_anno_list_by_saddr(msk, &entry->addr))
1679                         alist.ids[alist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr);
1680         }
1681
1682         spin_lock_bh(&msk->pm.lock);
1683         if (alist.nr) {
1684                 msk->pm.add_addr_signaled -= alist.nr;
1685                 mptcp_pm_remove_addr(msk, &alist);
1686         }
1687         if (slist.nr)
1688                 mptcp_pm_nl_rm_subflow_received(msk, &slist);
1689         /* Reset counters: maybe some subflows have been removed before */
1690         bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1691         msk->pm.local_addr_used = 0;
1692         spin_unlock_bh(&msk->pm.lock);
1693 }
1694
1695 static void mptcp_nl_flush_addrs_list(struct net *net,
1696                                       struct list_head *rm_list)
1697 {
1698         long s_slot = 0, s_num = 0;
1699         struct mptcp_sock *msk;
1700
1701         if (list_empty(rm_list))
1702                 return;
1703
1704         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1705                 struct sock *sk = (struct sock *)msk;
1706
1707                 if (!mptcp_pm_is_userspace(msk)) {
1708                         lock_sock(sk);
1709                         mptcp_pm_flush_addrs_and_subflows(msk, rm_list);
1710                         release_sock(sk);
1711                 }
1712
1713                 sock_put(sk);
1714                 cond_resched();
1715         }
1716 }
1717
1718 /* caller must ensure the RCU grace period is already elapsed */
1719 static void __flush_addrs(struct list_head *list)
1720 {
1721         while (!list_empty(list)) {
1722                 struct mptcp_pm_addr_entry *cur;
1723
1724                 cur = list_entry(list->next,
1725                                  struct mptcp_pm_addr_entry, list);
1726                 list_del_rcu(&cur->list);
1727                 __mptcp_pm_release_addr_entry(cur);
1728         }
1729 }
1730
1731 static void __reset_counters(struct pm_nl_pernet *pernet)
1732 {
1733         WRITE_ONCE(pernet->add_addr_signal_max, 0);
1734         WRITE_ONCE(pernet->add_addr_accept_max, 0);
1735         WRITE_ONCE(pernet->local_addr_max, 0);
1736         pernet->addrs = 0;
1737 }
1738
1739 int mptcp_pm_nl_flush_addrs_doit(struct sk_buff *skb, struct genl_info *info)
1740 {
1741         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1742         LIST_HEAD(free_list);
1743
1744         spin_lock_bh(&pernet->lock);
1745         list_splice_init(&pernet->local_addr_list, &free_list);
1746         __reset_counters(pernet);
1747         pernet->next_id = 1;
1748         bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1749         spin_unlock_bh(&pernet->lock);
1750         mptcp_nl_flush_addrs_list(sock_net(skb->sk), &free_list);
1751         synchronize_rcu();
1752         __flush_addrs(&free_list);
1753         return 0;
1754 }
1755
1756 int mptcp_nl_fill_addr(struct sk_buff *skb,
1757                        struct mptcp_pm_addr_entry *entry)
1758 {
1759         struct mptcp_addr_info *addr = &entry->addr;
1760         struct nlattr *attr;
1761
1762         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1763         if (!attr)
1764                 return -EMSGSIZE;
1765
1766         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1767                 goto nla_put_failure;
1768         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1769                 goto nla_put_failure;
1770         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1771                 goto nla_put_failure;
1772         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1773                 goto nla_put_failure;
1774         if (entry->ifindex &&
1775             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1776                 goto nla_put_failure;
1777
1778         if (addr->family == AF_INET &&
1779             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1780                             addr->addr.s_addr))
1781                 goto nla_put_failure;
1782 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1783         else if (addr->family == AF_INET6 &&
1784                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1785                 goto nla_put_failure;
1786 #endif
1787         nla_nest_end(skb, attr);
1788         return 0;
1789
1790 nla_put_failure:
1791         nla_nest_cancel(skb, attr);
1792         return -EMSGSIZE;
1793 }
1794
1795 int mptcp_pm_nl_get_addr(struct sk_buff *skb, struct genl_info *info)
1796 {
1797         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1798         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1799         struct mptcp_pm_addr_entry addr, *entry;
1800         struct sk_buff *msg;
1801         void *reply;
1802         int ret;
1803
1804         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1805         if (ret < 0)
1806                 return ret;
1807
1808         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1809         if (!msg)
1810                 return -ENOMEM;
1811
1812         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1813                                   info->genlhdr->cmd);
1814         if (!reply) {
1815                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1816                 ret = -EMSGSIZE;
1817                 goto fail;
1818         }
1819
1820         rcu_read_lock();
1821         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1822         if (!entry) {
1823                 GENL_SET_ERR_MSG(info, "address not found");
1824                 ret = -EINVAL;
1825                 goto unlock_fail;
1826         }
1827
1828         ret = mptcp_nl_fill_addr(msg, entry);
1829         if (ret)
1830                 goto unlock_fail;
1831
1832         genlmsg_end(msg, reply);
1833         ret = genlmsg_reply(msg, info);
1834         rcu_read_unlock();
1835         return ret;
1836
1837 unlock_fail:
1838         rcu_read_unlock();
1839
1840 fail:
1841         nlmsg_free(msg);
1842         return ret;
1843 }
1844
1845 int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
1846 {
1847         return mptcp_pm_get_addr(skb, info);
1848 }
1849
1850 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
1851                           struct netlink_callback *cb)
1852 {
1853         struct net *net = sock_net(msg->sk);
1854         struct mptcp_pm_addr_entry *entry;
1855         struct pm_nl_pernet *pernet;
1856         int id = cb->args[0];
1857         void *hdr;
1858         int i;
1859
1860         pernet = pm_nl_get_pernet(net);
1861
1862         rcu_read_lock();
1863         for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1864                 if (test_bit(i, pernet->id_bitmap)) {
1865                         entry = __lookup_addr_by_id(pernet, i);
1866                         if (!entry)
1867                                 break;
1868
1869                         if (entry->addr.id <= id)
1870                                 continue;
1871
1872                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1873                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1874                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1875                         if (!hdr)
1876                                 break;
1877
1878                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1879                                 genlmsg_cancel(msg, hdr);
1880                                 break;
1881                         }
1882
1883                         id = entry->addr.id;
1884                         genlmsg_end(msg, hdr);
1885                 }
1886         }
1887         rcu_read_unlock();
1888
1889         cb->args[0] = id;
1890         return msg->len;
1891 }
1892
1893 int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
1894                                 struct netlink_callback *cb)
1895 {
1896         return mptcp_pm_dump_addr(msg, cb);
1897 }
1898
1899 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1900 {
1901         struct nlattr *attr = info->attrs[id];
1902
1903         if (!attr)
1904                 return 0;
1905
1906         *limit = nla_get_u32(attr);
1907         if (*limit > MPTCP_PM_ADDR_MAX) {
1908                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1909                 return -EINVAL;
1910         }
1911         return 0;
1912 }
1913
1914 int mptcp_pm_nl_set_limits_doit(struct sk_buff *skb, struct genl_info *info)
1915 {
1916         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1917         unsigned int rcv_addrs, subflows;
1918         int ret;
1919
1920         spin_lock_bh(&pernet->lock);
1921         rcv_addrs = pernet->add_addr_accept_max;
1922         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1923         if (ret)
1924                 goto unlock;
1925
1926         subflows = pernet->subflows_max;
1927         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1928         if (ret)
1929                 goto unlock;
1930
1931         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1932         WRITE_ONCE(pernet->subflows_max, subflows);
1933
1934 unlock:
1935         spin_unlock_bh(&pernet->lock);
1936         return ret;
1937 }
1938
1939 int mptcp_pm_nl_get_limits_doit(struct sk_buff *skb, struct genl_info *info)
1940 {
1941         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1942         struct sk_buff *msg;
1943         void *reply;
1944
1945         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1946         if (!msg)
1947                 return -ENOMEM;
1948
1949         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1950                                   MPTCP_PM_CMD_GET_LIMITS);
1951         if (!reply)
1952                 goto fail;
1953
1954         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1955                         READ_ONCE(pernet->add_addr_accept_max)))
1956                 goto fail;
1957
1958         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1959                         READ_ONCE(pernet->subflows_max)))
1960                 goto fail;
1961
1962         genlmsg_end(msg, reply);
1963         return genlmsg_reply(msg, info);
1964
1965 fail:
1966         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1967         nlmsg_free(msg);
1968         return -EMSGSIZE;
1969 }
1970
1971 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
1972                                  struct mptcp_addr_info *addr)
1973 {
1974         struct mptcp_rm_list list = { .nr = 0 };
1975
1976         list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr);
1977
1978         spin_lock_bh(&msk->pm.lock);
1979         mptcp_pm_nl_rm_subflow_received(msk, &list);
1980         __mark_subflow_endp_available(msk, list.ids[0]);
1981         mptcp_pm_create_subflow_or_signal_addr(msk);
1982         spin_unlock_bh(&msk->pm.lock);
1983 }
1984
1985 static int mptcp_nl_set_flags(struct net *net,
1986                               struct mptcp_addr_info *addr,
1987                               u8 bkup, u8 changed)
1988 {
1989         long s_slot = 0, s_num = 0;
1990         struct mptcp_sock *msk;
1991         int ret = -EINVAL;
1992
1993         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1994                 struct sock *sk = (struct sock *)msk;
1995
1996                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1997                         goto next;
1998
1999                 lock_sock(sk);
2000                 if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
2001                         ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
2002                 if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
2003                         mptcp_pm_nl_fullmesh(msk, addr);
2004                 release_sock(sk);
2005
2006 next:
2007                 sock_put(sk);
2008                 cond_resched();
2009         }
2010
2011         return ret;
2012 }
2013
2014 int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
2015 {
2016         struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
2017         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
2018         u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
2019                            MPTCP_PM_ADDR_FLAG_FULLMESH;
2020         struct net *net = sock_net(skb->sk);
2021         struct mptcp_pm_addr_entry *entry;
2022         struct pm_nl_pernet *pernet;
2023         u8 lookup_by_id = 0;
2024         u8 bkup = 0;
2025         int ret;
2026
2027         pernet = pm_nl_get_pernet(net);
2028
2029         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
2030         if (ret < 0)
2031                 return ret;
2032
2033         if (addr.addr.family == AF_UNSPEC) {
2034                 lookup_by_id = 1;
2035                 if (!addr.addr.id) {
2036                         GENL_SET_ERR_MSG(info, "missing required inputs");
2037                         return -EOPNOTSUPP;
2038                 }
2039         }
2040
2041         if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
2042                 bkup = 1;
2043
2044         spin_lock_bh(&pernet->lock);
2045         entry = lookup_by_id ? __lookup_addr_by_id(pernet, addr.addr.id) :
2046                                __lookup_addr(pernet, &addr.addr);
2047         if (!entry) {
2048                 spin_unlock_bh(&pernet->lock);
2049                 GENL_SET_ERR_MSG(info, "address not found");
2050                 return -EINVAL;
2051         }
2052         if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
2053             (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
2054                 spin_unlock_bh(&pernet->lock);
2055                 GENL_SET_ERR_MSG(info, "invalid addr flags");
2056                 return -EINVAL;
2057         }
2058
2059         changed = (addr.flags ^ entry->flags) & mask;
2060         entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
2061         addr = *entry;
2062         spin_unlock_bh(&pernet->lock);
2063
2064         mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
2065         return 0;
2066 }
2067
2068 int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
2069 {
2070         return mptcp_pm_set_flags(skb, info);
2071 }
2072
2073 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
2074 {
2075         genlmsg_multicast_netns(&mptcp_genl_family, net,
2076                                 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
2077 }
2078
2079 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)
2080 {
2081         return genl_has_listeners(&mptcp_genl_family,
2082                                   sock_net((const struct sock *)msk),
2083                                   MPTCP_PM_EV_GRP_OFFSET);
2084 }
2085
2086 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
2087 {
2088         const struct inet_sock *issk = inet_sk(ssk);
2089         const struct mptcp_subflow_context *sf;
2090
2091         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2092                 return -EMSGSIZE;
2093
2094         switch (ssk->sk_family) {
2095         case AF_INET:
2096                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2097                         return -EMSGSIZE;
2098                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
2099                         return -EMSGSIZE;
2100                 break;
2101 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2102         case AF_INET6: {
2103                 const struct ipv6_pinfo *np = inet6_sk(ssk);
2104
2105                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2106                         return -EMSGSIZE;
2107                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
2108                         return -EMSGSIZE;
2109                 break;
2110         }
2111 #endif
2112         default:
2113                 WARN_ON_ONCE(1);
2114                 return -EMSGSIZE;
2115         }
2116
2117         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2118                 return -EMSGSIZE;
2119         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
2120                 return -EMSGSIZE;
2121
2122         sf = mptcp_subflow_ctx(ssk);
2123         if (WARN_ON_ONCE(!sf))
2124                 return -EINVAL;
2125
2126         if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf)))
2127                 return -EMSGSIZE;
2128
2129         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
2130                 return -EMSGSIZE;
2131
2132         return 0;
2133 }
2134
2135 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
2136                                          const struct mptcp_sock *msk,
2137                                          const struct sock *ssk)
2138 {
2139         const struct sock *sk = (const struct sock *)msk;
2140         const struct mptcp_subflow_context *sf;
2141         u8 sk_err;
2142
2143         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2144                 return -EMSGSIZE;
2145
2146         if (mptcp_event_add_subflow(skb, ssk))
2147                 return -EMSGSIZE;
2148
2149         sf = mptcp_subflow_ctx(ssk);
2150         if (WARN_ON_ONCE(!sf))
2151                 return -EINVAL;
2152
2153         if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
2154                 return -EMSGSIZE;
2155
2156         if (ssk->sk_bound_dev_if &&
2157             nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
2158                 return -EMSGSIZE;
2159
2160         sk_err = READ_ONCE(ssk->sk_err);
2161         if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
2162             nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
2163                 return -EMSGSIZE;
2164
2165         return 0;
2166 }
2167
2168 static int mptcp_event_sub_established(struct sk_buff *skb,
2169                                        const struct mptcp_sock *msk,
2170                                        const struct sock *ssk)
2171 {
2172         return mptcp_event_put_token_and_ssk(skb, msk, ssk);
2173 }
2174
2175 static int mptcp_event_sub_closed(struct sk_buff *skb,
2176                                   const struct mptcp_sock *msk,
2177                                   const struct sock *ssk)
2178 {
2179         const struct mptcp_subflow_context *sf;
2180
2181         if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
2182                 return -EMSGSIZE;
2183
2184         sf = mptcp_subflow_ctx(ssk);
2185         if (!sf->reset_seen)
2186                 return 0;
2187
2188         if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
2189                 return -EMSGSIZE;
2190
2191         if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
2192                 return -EMSGSIZE;
2193
2194         return 0;
2195 }
2196
2197 static int mptcp_event_created(struct sk_buff *skb,
2198                                const struct mptcp_sock *msk,
2199                                const struct sock *ssk)
2200 {
2201         int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token));
2202
2203         if (err)
2204                 return err;
2205
2206         if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
2207                 return -EMSGSIZE;
2208
2209         return mptcp_event_add_subflow(skb, ssk);
2210 }
2211
2212 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
2213 {
2214         struct net *net = sock_net((const struct sock *)msk);
2215         struct nlmsghdr *nlh;
2216         struct sk_buff *skb;
2217
2218         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2219                 return;
2220
2221         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2222         if (!skb)
2223                 return;
2224
2225         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
2226         if (!nlh)
2227                 goto nla_put_failure;
2228
2229         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2230                 goto nla_put_failure;
2231
2232         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
2233                 goto nla_put_failure;
2234
2235         genlmsg_end(skb, nlh);
2236         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2237         return;
2238
2239 nla_put_failure:
2240         nlmsg_free(skb);
2241 }
2242
2243 void mptcp_event_addr_announced(const struct sock *ssk,
2244                                 const struct mptcp_addr_info *info)
2245 {
2246         struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
2247         struct mptcp_sock *msk = mptcp_sk(subflow->conn);
2248         struct net *net = sock_net(ssk);
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,
2260                           MPTCP_EVENT_ANNOUNCED);
2261         if (!nlh)
2262                 goto nla_put_failure;
2263
2264         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2265                 goto nla_put_failure;
2266
2267         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2268                 goto nla_put_failure;
2269
2270         if (nla_put_be16(skb, MPTCP_ATTR_DPORT,
2271                          info->port == 0 ?
2272                          inet_sk(ssk)->inet_dport :
2273                          info->port))
2274                 goto nla_put_failure;
2275
2276         switch (info->family) {
2277         case AF_INET:
2278                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2279                         goto nla_put_failure;
2280                 break;
2281 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2282         case AF_INET6:
2283                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2284                         goto nla_put_failure;
2285                 break;
2286 #endif
2287         default:
2288                 WARN_ON_ONCE(1);
2289                 goto nla_put_failure;
2290         }
2291
2292         genlmsg_end(skb, nlh);
2293         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2294         return;
2295
2296 nla_put_failure:
2297         nlmsg_free(skb);
2298 }
2299
2300 void mptcp_event_pm_listener(const struct sock *ssk,
2301                              enum mptcp_event_type event)
2302 {
2303         const struct inet_sock *issk = inet_sk(ssk);
2304         struct net *net = sock_net(ssk);
2305         struct nlmsghdr *nlh;
2306         struct sk_buff *skb;
2307
2308         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2309                 return;
2310
2311         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
2312         if (!skb)
2313                 return;
2314
2315         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event);
2316         if (!nlh)
2317                 goto nla_put_failure;
2318
2319         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2320                 goto nla_put_failure;
2321
2322         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2323                 goto nla_put_failure;
2324
2325         switch (ssk->sk_family) {
2326         case AF_INET:
2327                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2328                         goto nla_put_failure;
2329                 break;
2330 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2331         case AF_INET6: {
2332                 const struct ipv6_pinfo *np = inet6_sk(ssk);
2333
2334                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2335                         goto nla_put_failure;
2336                 break;
2337         }
2338 #endif
2339         default:
2340                 WARN_ON_ONCE(1);
2341                 goto nla_put_failure;
2342         }
2343
2344         genlmsg_end(skb, nlh);
2345         mptcp_nl_mcast_send(net, skb, GFP_KERNEL);
2346         return;
2347
2348 nla_put_failure:
2349         nlmsg_free(skb);
2350 }
2351
2352 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2353                  const struct sock *ssk, gfp_t gfp)
2354 {
2355         struct net *net = sock_net((const struct sock *)msk);
2356         struct nlmsghdr *nlh;
2357         struct sk_buff *skb;
2358
2359         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2360                 return;
2361
2362         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2363         if (!skb)
2364                 return;
2365
2366         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2367         if (!nlh)
2368                 goto nla_put_failure;
2369
2370         switch (type) {
2371         case MPTCP_EVENT_UNSPEC:
2372                 WARN_ON_ONCE(1);
2373                 break;
2374         case MPTCP_EVENT_CREATED:
2375         case MPTCP_EVENT_ESTABLISHED:
2376                 if (mptcp_event_created(skb, msk, ssk) < 0)
2377                         goto nla_put_failure;
2378                 break;
2379         case MPTCP_EVENT_CLOSED:
2380                 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)) < 0)
2381                         goto nla_put_failure;
2382                 break;
2383         case MPTCP_EVENT_ANNOUNCED:
2384         case MPTCP_EVENT_REMOVED:
2385                 /* call mptcp_event_addr_announced()/removed instead */
2386                 WARN_ON_ONCE(1);
2387                 break;
2388         case MPTCP_EVENT_SUB_ESTABLISHED:
2389         case MPTCP_EVENT_SUB_PRIORITY:
2390                 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2391                         goto nla_put_failure;
2392                 break;
2393         case MPTCP_EVENT_SUB_CLOSED:
2394                 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2395                         goto nla_put_failure;
2396                 break;
2397         case MPTCP_EVENT_LISTENER_CREATED:
2398         case MPTCP_EVENT_LISTENER_CLOSED:
2399                 break;
2400         }
2401
2402         genlmsg_end(skb, nlh);
2403         mptcp_nl_mcast_send(net, skb, gfp);
2404         return;
2405
2406 nla_put_failure:
2407         nlmsg_free(skb);
2408 }
2409
2410 struct genl_family mptcp_genl_family __ro_after_init = {
2411         .name           = MPTCP_PM_NAME,
2412         .version        = MPTCP_PM_VER,
2413         .netnsok        = true,
2414         .module         = THIS_MODULE,
2415         .ops            = mptcp_pm_nl_ops,
2416         .n_ops          = ARRAY_SIZE(mptcp_pm_nl_ops),
2417         .resv_start_op  = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1,
2418         .mcgrps         = mptcp_pm_mcgrps,
2419         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
2420 };
2421
2422 static int __net_init pm_nl_init_net(struct net *net)
2423 {
2424         struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2425
2426         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2427
2428         /* Cit. 2 subflows ought to be enough for anybody. */
2429         pernet->subflows_max = 2;
2430         pernet->next_id = 1;
2431         pernet->stale_loss_cnt = 4;
2432         spin_lock_init(&pernet->lock);
2433
2434         /* No need to initialize other pernet fields, the struct is zeroed at
2435          * allocation time.
2436          */
2437
2438         return 0;
2439 }
2440
2441 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2442 {
2443         struct net *net;
2444
2445         list_for_each_entry(net, net_list, exit_list) {
2446                 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2447
2448                 /* net is removed from namespace list, can't race with
2449                  * other modifiers, also netns core already waited for a
2450                  * RCU grace period.
2451                  */
2452                 __flush_addrs(&pernet->local_addr_list);
2453         }
2454 }
2455
2456 static struct pernet_operations mptcp_pm_pernet_ops = {
2457         .init = pm_nl_init_net,
2458         .exit_batch = pm_nl_exit_net,
2459         .id = &pm_nl_pernet_id,
2460         .size = sizeof(struct pm_nl_pernet),
2461 };
2462
2463 void __init mptcp_pm_nl_init(void)
2464 {
2465         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2466                 panic("Failed to register MPTCP PM pernet subsystem.\n");
2467
2468         if (genl_register_family(&mptcp_genl_family))
2469                 panic("Failed to register MPTCP PM netlink family\n");
2470 }