net/mptcp/pm_netlink.c

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