net/mptcp/pm_netlink.c

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