net/mptcp/pm_netlink.c

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