net/mptcp/pm_netlink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2020, Red Hat, Inc.
   5  */
   6
   7 #define pr_fmt(fmt) "MPTCP: " fmt
   8
   9 #include <linux/inet.h>
  10 #include <linux/kernel.h>
  11 #include <net/tcp.h>
  12 #include <net/netns/generic.h>
  13 #include <net/mptcp.h>
  14 #include <net/genetlink.h>
  15 #include <uapi/linux/mptcp.h>
  16
  17 #include "protocol.h"
  18 #include "mib.h"
  19
  20 /* forward declaration */
  21 static struct genl_family mptcp_genl_family;
  22
  23 static int pm_nl_pernet_id;
  24
  25 struct mptcp_pm_addr_entry {
  26         struct list_head        list;
  27         struct mptcp_addr_info  addr;
  28         struct rcu_head         rcu;
  29 };
  30
  31 struct mptcp_pm_add_entry {
  32         struct list_head        list;
  33         struct mptcp_addr_info  addr;
  34         struct timer_list       add_timer;
  35         struct mptcp_sock       *sock;
  36         u8                      retrans_times;
  37 };
  38
  39 #define MAX_ADDR_ID             255
  40 #define BITMAP_SZ DIV_ROUND_UP(MAX_ADDR_ID + 1, BITS_PER_LONG)
  41
  42 struct pm_nl_pernet {
  43         /* protects pernet updates */
  44         spinlock_t              lock;
  45         struct list_head        local_addr_list;
  46         unsigned int            addrs;
  47         unsigned int            add_addr_signal_max;
  48         unsigned int            add_addr_accept_max;
  49         unsigned int            local_addr_max;
  50         unsigned int            subflows_max;
  51         unsigned int            next_id;
  52         unsigned long           id_bitmap[BITMAP_SZ];
  53 };
  54
  55 #define MPTCP_PM_ADDR_MAX       8
  56 #define ADD_ADDR_RETRANS_MAX    3
  57
  58 static bool addresses_equal(const struct mptcp_addr_info *a,
  59                             struct mptcp_addr_info *b, bool use_port)
  60 {
  61         bool addr_equals = false;
  62
  63         if (a->family != b->family)
  64                 return false;
  65
  66         if (a->family == AF_INET)
  67                 addr_equals = a->addr.s_addr == b->addr.s_addr;
  68 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  69         else
  70                 addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
  71 #endif
  72
  73         if (!addr_equals)
  74                 return false;
  75         if (!use_port)
  76                 return true;
  77
  78         return a->port == b->port;
  79 }
  80
  81 static bool address_zero(const struct mptcp_addr_info *addr)
  82 {
  83         struct mptcp_addr_info zero;
  84
  85         memset(&zero, 0, sizeof(zero));
  86         zero.family = addr->family;
  87
  88         return addresses_equal(addr, &zero, false);
  89 }
  90
  91 static void local_address(const struct sock_common *skc,
  92                           struct mptcp_addr_info *addr)
  93 {
  94         addr->port = 0;
  95         addr->family = skc->skc_family;
  96         if (addr->family == AF_INET)
  97                 addr->addr.s_addr = skc->skc_rcv_saddr;
  98 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  99         else if (addr->family == AF_INET6)
 100                 addr->addr6 = skc->skc_v6_rcv_saddr;
 101 #endif
 102 }
 103
 104 static void remote_address(const struct sock_common *skc,
 105                            struct mptcp_addr_info *addr)
 106 {
 107         addr->family = skc->skc_family;
 108         addr->port = skc->skc_dport;
 109         if (addr->family == AF_INET)
 110                 addr->addr.s_addr = skc->skc_daddr;
 111 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 112         else if (addr->family == AF_INET6)
 113                 addr->addr6 = skc->skc_v6_daddr;
 114 #endif
 115 }
 116
 117 static bool lookup_subflow_by_saddr(const struct list_head *list,
 118                                     struct mptcp_addr_info *saddr)
 119 {
 120         struct mptcp_subflow_context *subflow;
 121         struct mptcp_addr_info cur;
 122         struct sock_common *skc;
 123
 124         list_for_each_entry(subflow, list, node) {
 125                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 126
 127                 local_address(skc, &cur);
 128                 if (addresses_equal(&cur, saddr, false))
 129                         return true;
 130         }
 131
 132         return false;
 133 }
 134
 135 static struct mptcp_pm_addr_entry *
 136 select_local_address(const struct pm_nl_pernet *pernet,
 137                      struct mptcp_sock *msk)
 138 {
 139         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 140
 141         rcu_read_lock();
 142         __mptcp_flush_join_list(msk);
 143         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 144                 if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 145                         continue;
 146
 147                 /* avoid any address already in use by subflows and
 148                  * pending join
 149                  */
 150                 if (entry->addr.family == ((struct sock *)msk)->sk_family &&
 151                     !lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) {
 152                         ret = entry;
 153                         break;
 154                 }
 155         }
 156         rcu_read_unlock();
 157         return ret;
 158 }
 159
 160 static struct mptcp_pm_addr_entry *
 161 select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos)
 162 {
 163         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 164         int i = 0;
 165
 166         rcu_read_lock();
 167         /* do not keep any additional per socket state, just signal
 168          * the address list in order.
 169          * Note: removal from the local address list during the msk life-cycle
 170          * can lead to additional addresses not being announced.
 171          */
 172         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 173                 if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
 174                         continue;
 175                 if (i++ == pos) {
 176                         ret = entry;
 177                         break;
 178                 }
 179         }
 180         rcu_read_unlock();
 181         return ret;
 182 }
 183
 184 static void check_work_pending(struct mptcp_sock *msk)
 185 {
 186         if (msk->pm.add_addr_signaled == msk->pm.add_addr_signal_max &&
 187             (msk->pm.local_addr_used == msk->pm.local_addr_max ||
 188              msk->pm.subflows == msk->pm.subflows_max))
 189                 WRITE_ONCE(msk->pm.work_pending, false);
 190 }
 191
 192 static struct mptcp_pm_add_entry *
 193 lookup_anno_list_by_saddr(struct mptcp_sock *msk,
 194                           struct mptcp_addr_info *addr)
 195 {
 196         struct mptcp_pm_add_entry *entry;
 197
 198         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 199                 if (addresses_equal(&entry->addr, addr, false))
 200                         return entry;
 201         }
 202
 203         return NULL;
 204 }
 205
 206 static void mptcp_pm_add_timer(struct timer_list *timer)
 207 {
 208         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 209         struct mptcp_sock *msk = entry->sock;
 210         struct sock *sk = (struct sock *)msk;
 211
 212         pr_debug("msk=%p", msk);
 213
 214         if (!msk)
 215                 return;
 216
 217         if (inet_sk_state_load(sk) == TCP_CLOSE)
 218                 return;
 219
 220         if (!entry->addr.id)
 221                 return;
 222
 223         if (mptcp_pm_should_add_signal(msk)) {
 224                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 225                 goto out;
 226         }
 227
 228         spin_lock_bh(&msk->pm.lock);
 229
 230         if (!mptcp_pm_should_add_signal(msk)) {
 231                 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
 232                 mptcp_pm_announce_addr(msk, &entry->addr, false, entry->addr.port);
 233                 mptcp_pm_add_addr_send_ack(msk);
 234                 entry->retrans_times++;
 235         }
 236
 237         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 238                 sk_reset_timer(sk, timer,
 239                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
 240
 241         spin_unlock_bh(&msk->pm.lock);
 242
 243 out:
 244         __sock_put(sk);
 245 }
 246
 247 struct mptcp_pm_add_entry *
 248 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 249                        struct mptcp_addr_info *addr)
 250 {
 251         struct mptcp_pm_add_entry *entry;
 252         struct sock *sk = (struct sock *)msk;
 253
 254         spin_lock_bh(&msk->pm.lock);
 255         entry = lookup_anno_list_by_saddr(msk, addr);
 256         if (entry)
 257                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 258         spin_unlock_bh(&msk->pm.lock);
 259
 260         if (entry)
 261                 sk_stop_timer_sync(sk, &entry->add_timer);
 262
 263         return entry;
 264 }
 265
 266 static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 267                                      struct mptcp_pm_addr_entry *entry)
 268 {
 269         struct mptcp_pm_add_entry *add_entry = NULL;
 270         struct sock *sk = (struct sock *)msk;
 271         struct net *net = sock_net(sk);
 272
 273         if (lookup_anno_list_by_saddr(msk, &entry->addr))
 274                 return false;
 275
 276         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
 277         if (!add_entry)
 278                 return false;
 279
 280         list_add(&add_entry->list, &msk->pm.anno_list);
 281
 282         add_entry->addr = entry->addr;
 283         add_entry->sock = msk;
 284         add_entry->retrans_times = 0;
 285
 286         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 287         sk_reset_timer(sk, &add_entry->add_timer,
 288                        jiffies + mptcp_get_add_addr_timeout(net));
 289
 290         return true;
 291 }
 292
 293 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 294 {
 295         struct mptcp_pm_add_entry *entry, *tmp;
 296         struct sock *sk = (struct sock *)msk;
 297         LIST_HEAD(free_list);
 298
 299         pr_debug("msk=%p", msk);
 300
 301         spin_lock_bh(&msk->pm.lock);
 302         list_splice_init(&msk->pm.anno_list, &free_list);
 303         spin_unlock_bh(&msk->pm.lock);
 304
 305         list_for_each_entry_safe(entry, tmp, &free_list, list) {
 306                 sk_stop_timer_sync(sk, &entry->add_timer);
 307                 kfree(entry);
 308         }
 309 }
 310
 311 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 312 {
 313         struct mptcp_addr_info remote = { 0 };
 314         struct sock *sk = (struct sock *)msk;
 315         struct mptcp_pm_addr_entry *local;
 316         struct pm_nl_pernet *pernet;
 317
 318         pernet = net_generic(sock_net(sk), pm_nl_pernet_id);
 319
 320         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
 321                  msk->pm.local_addr_used, msk->pm.local_addr_max,
 322                  msk->pm.add_addr_signaled, msk->pm.add_addr_signal_max,
 323                  msk->pm.subflows, msk->pm.subflows_max);
 324
 325         /* check first for announce */
 326         if (msk->pm.add_addr_signaled < msk->pm.add_addr_signal_max) {
 327                 local = select_signal_address(pernet,
 328                                               msk->pm.add_addr_signaled);
 329
 330                 if (local) {
 331                         if (mptcp_pm_alloc_anno_list(msk, local)) {
 332                                 msk->pm.add_addr_signaled++;
 333                                 mptcp_pm_announce_addr(msk, &local->addr, false, local->addr.port);
 334                                 mptcp_pm_nl_add_addr_send_ack(msk);
 335                         }
 336                 } else {
 337                         /* pick failed, avoid fourther attempts later */
 338                         msk->pm.local_addr_used = msk->pm.add_addr_signal_max;
 339                 }
 340
 341                 check_work_pending(msk);
 342         }
 343
 344         /* check if should create a new subflow */
 345         if (msk->pm.local_addr_used < msk->pm.local_addr_max &&
 346             msk->pm.subflows < msk->pm.subflows_max) {
 347                 remote_address((struct sock_common *)sk, &remote);
 348
 349                 local = select_local_address(pernet, msk);
 350                 if (local) {
 351                         msk->pm.local_addr_used++;
 352                         msk->pm.subflows++;
 353                         check_work_pending(msk);
 354                         spin_unlock_bh(&msk->pm.lock);
 355                         __mptcp_subflow_connect(sk, &local->addr, &remote);
 356                         spin_lock_bh(&msk->pm.lock);
 357                         return;
 358                 }
 359
 360                 /* lookup failed, avoid fourther attempts later */
 361                 msk->pm.local_addr_used = msk->pm.local_addr_max;
 362                 check_work_pending(msk);
 363         }
 364 }
 365
 366 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 367 {
 368         mptcp_pm_create_subflow_or_signal_addr(msk);
 369 }
 370
 371 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 372 {
 373         mptcp_pm_create_subflow_or_signal_addr(msk);
 374 }
 375
 376 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 377 {
 378         struct sock *sk = (struct sock *)msk;
 379         struct mptcp_addr_info remote;
 380         struct mptcp_addr_info local;
 381         bool use_port = false;
 382
 383         pr_debug("accepted %d:%d remote family %d",
 384                  msk->pm.add_addr_accepted, msk->pm.add_addr_accept_max,
 385                  msk->pm.remote.family);
 386         msk->pm.add_addr_accepted++;
 387         msk->pm.subflows++;
 388         if (msk->pm.add_addr_accepted >= msk->pm.add_addr_accept_max ||
 389             msk->pm.subflows >= msk->pm.subflows_max)
 390                 WRITE_ONCE(msk->pm.accept_addr, false);
 391
 392         /* connect to the specified remote address, using whatever
 393          * local address the routing configuration will pick.
 394          */
 395         remote = msk->pm.remote;
 396         if (!remote.port)
 397                 remote.port = sk->sk_dport;
 398         else
 399                 use_port = true;
 400         memset(&local, 0, sizeof(local));
 401         local.family = remote.family;
 402
 403         spin_unlock_bh(&msk->pm.lock);
 404         __mptcp_subflow_connect(sk, &local, &remote);
 405         spin_lock_bh(&msk->pm.lock);
 406
 407         mptcp_pm_announce_addr(msk, &remote, true, use_port);
 408         mptcp_pm_nl_add_addr_send_ack(msk);
 409 }
 410
 411 void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk)
 412 {
 413         struct mptcp_subflow_context *subflow;
 414
 415         if (!mptcp_pm_should_add_signal_ipv6(msk) &&
 416             !mptcp_pm_should_add_signal_port(msk))
 417                 return;
 418
 419         __mptcp_flush_join_list(msk);
 420         subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
 421         if (subflow) {
 422                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 423                 u8 add_addr;
 424
 425                 spin_unlock_bh(&msk->pm.lock);
 426                 if (mptcp_pm_should_add_signal_ipv6(msk))
 427                         pr_debug("send ack for add_addr6");
 428                 if (mptcp_pm_should_add_signal_port(msk))
 429                         pr_debug("send ack for add_addr_port");
 430
 431                 lock_sock(ssk);
 432                 tcp_send_ack(ssk);
 433                 release_sock(ssk);
 434                 spin_lock_bh(&msk->pm.lock);
 435
 436                 add_addr = READ_ONCE(msk->pm.addr_signal);
 437                 if (mptcp_pm_should_add_signal_ipv6(msk))
 438                         add_addr &= ~BIT(MPTCP_ADD_ADDR_IPV6);
 439                 if (mptcp_pm_should_add_signal_port(msk))
 440                         add_addr &= ~BIT(MPTCP_ADD_ADDR_PORT);
 441                 WRITE_ONCE(msk->pm.addr_signal, add_addr);
 442         }
 443 }
 444
 445 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 446                                  struct mptcp_addr_info *addr,
 447                                  u8 bkup)
 448 {
 449         struct mptcp_subflow_context *subflow;
 450
 451         pr_debug("bkup=%d", bkup);
 452
 453         mptcp_for_each_subflow(msk, subflow) {
 454                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 455                 struct mptcp_addr_info local;
 456
 457                 local_address((struct sock_common *)ssk, &local);
 458                 if (!addresses_equal(&local, addr, addr->port))
 459                         continue;
 460
 461                 subflow->backup = bkup;
 462                 subflow->send_mp_prio = 1;
 463                 subflow->request_bkup = bkup;
 464
 465                 spin_unlock_bh(&msk->pm.lock);
 466                 pr_debug("send ack for mp_prio");
 467                 lock_sock(ssk);
 468                 tcp_send_ack(ssk);
 469                 release_sock(ssk);
 470                 spin_lock_bh(&msk->pm.lock);
 471
 472                 return 0;
 473         }
 474
 475         return -EINVAL;
 476 }
 477
 478 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
 479 {
 480         struct mptcp_subflow_context *subflow, *tmp;
 481         struct sock *sk = (struct sock *)msk;
 482
 483         pr_debug("address rm_id %d", msk->pm.rm_id);
 484
 485         if (!msk->pm.rm_id)
 486                 return;
 487
 488         if (list_empty(&msk->conn_list))
 489                 return;
 490
 491         list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
 492                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 493                 int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 494
 495                 if (msk->pm.rm_id != subflow->remote_id)
 496                         continue;
 497
 498                 spin_unlock_bh(&msk->pm.lock);
 499                 mptcp_subflow_shutdown(sk, ssk, how);
 500                 __mptcp_close_ssk(sk, ssk, subflow);
 501                 spin_lock_bh(&msk->pm.lock);
 502
 503                 msk->pm.add_addr_accepted--;
 504                 msk->pm.subflows--;
 505                 WRITE_ONCE(msk->pm.accept_addr, true);
 506
 507                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMADDR);
 508
 509                 break;
 510         }
 511 }
 512
 513 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id)
 514 {
 515         struct mptcp_subflow_context *subflow, *tmp;
 516         struct sock *sk = (struct sock *)msk;
 517
 518         pr_debug("subflow rm_id %d", rm_id);
 519
 520         if (!rm_id)
 521                 return;
 522
 523         if (list_empty(&msk->conn_list))
 524                 return;
 525
 526         list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
 527                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 528                 int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 529
 530                 if (rm_id != subflow->local_id)
 531                         continue;
 532
 533                 spin_unlock_bh(&msk->pm.lock);
 534                 mptcp_subflow_shutdown(sk, ssk, how);
 535                 __mptcp_close_ssk(sk, ssk, subflow);
 536                 spin_lock_bh(&msk->pm.lock);
 537
 538                 msk->pm.local_addr_used--;
 539                 msk->pm.subflows--;
 540
 541                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW);
 542
 543                 break;
 544         }
 545 }
 546
 547 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
 548 {
 549         return (entry->addr.flags &
 550                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
 551                 MPTCP_PM_ADDR_FLAG_SIGNAL;
 552 }
 553
 554 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 555                                              struct mptcp_pm_addr_entry *entry)
 556 {
 557         struct mptcp_pm_addr_entry *cur;
 558         int ret = -EINVAL;
 559
 560         spin_lock_bh(&pernet->lock);
 561         /* to keep the code simple, don't do IDR-like allocation for address ID,
 562          * just bail when we exceed limits
 563          */
 564         if (pernet->next_id == MAX_ADDR_ID)
 565                 pernet->next_id = 1;
 566         if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
 567                 goto out;
 568         if (test_bit(entry->addr.id, pernet->id_bitmap))
 569                 goto out;
 570
 571         /* do not insert duplicate address, differentiate on port only
 572          * singled addresses
 573          */
 574         list_for_each_entry(cur, &pernet->local_addr_list, list) {
 575                 if (addresses_equal(&cur->addr, &entry->addr,
 576                                     address_use_port(entry) &&
 577                                     address_use_port(cur)))
 578                         goto out;
 579         }
 580
 581         if (!entry->addr.id) {
 582 find_next:
 583                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
 584                                                     MAX_ADDR_ID + 1,
 585                                                     pernet->next_id);
 586                 if ((!entry->addr.id || entry->addr.id > MAX_ADDR_ID) &&
 587                     pernet->next_id != 1) {
 588                         pernet->next_id = 1;
 589                         goto find_next;
 590                 }
 591         }
 592
 593         if (!entry->addr.id || entry->addr.id > MAX_ADDR_ID)
 594                 goto out;
 595
 596         __set_bit(entry->addr.id, pernet->id_bitmap);
 597         if (entry->addr.id > pernet->next_id)
 598                 pernet->next_id = entry->addr.id;
 599
 600         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
 601                 pernet->add_addr_signal_max++;
 602         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
 603                 pernet->local_addr_max++;
 604
 605         pernet->addrs++;
 606         list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
 607         ret = entry->addr.id;
 608
 609 out:
 610         spin_unlock_bh(&pernet->lock);
 611         return ret;
 612 }
 613
 614 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 615 {
 616         struct mptcp_pm_addr_entry *entry;
 617         struct mptcp_addr_info skc_local;
 618         struct mptcp_addr_info msk_local;
 619         struct pm_nl_pernet *pernet;
 620         int ret = -1;
 621
 622         if (WARN_ON_ONCE(!msk))
 623                 return -1;
 624
 625         /* The 0 ID mapping is defined by the first subflow, copied into the msk
 626          * addr
 627          */
 628         local_address((struct sock_common *)msk, &msk_local);
 629         local_address((struct sock_common *)skc, &skc_local);
 630         if (addresses_equal(&msk_local, &skc_local, false))
 631                 return 0;
 632
 633         if (address_zero(&skc_local))
 634                 return 0;
 635
 636         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 637
 638         rcu_read_lock();
 639         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 640                 if (addresses_equal(&entry->addr, &skc_local, false)) {
 641                         ret = entry->addr.id;
 642                         break;
 643                 }
 644         }
 645         rcu_read_unlock();
 646         if (ret >= 0)
 647                 return ret;
 648
 649         /* address not found, add to local list */
 650         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
 651         if (!entry)
 652                 return -ENOMEM;
 653
 654         entry->addr = skc_local;
 655         entry->addr.ifindex = 0;
 656         entry->addr.flags = 0;
 657         entry->addr.id = 0;
 658         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
 659         if (ret < 0)
 660                 kfree(entry);
 661
 662         return ret;
 663 }
 664
 665 void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
 666 {
 667         struct mptcp_pm_data *pm = &msk->pm;
 668         struct pm_nl_pernet *pernet;
 669         bool subflows;
 670
 671         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 672
 673         pm->add_addr_signal_max = READ_ONCE(pernet->add_addr_signal_max);
 674         pm->add_addr_accept_max = READ_ONCE(pernet->add_addr_accept_max);
 675         pm->local_addr_max = READ_ONCE(pernet->local_addr_max);
 676         pm->subflows_max = READ_ONCE(pernet->subflows_max);
 677         subflows = !!pm->subflows_max;
 678         WRITE_ONCE(pm->work_pending, (!!pm->local_addr_max && subflows) ||
 679                    !!pm->add_addr_signal_max);
 680         WRITE_ONCE(pm->accept_addr, !!pm->add_addr_accept_max && subflows);
 681         WRITE_ONCE(pm->accept_subflow, subflows);
 682 }
 683
 684 #define MPTCP_PM_CMD_GRP_OFFSET 0
 685
 686 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
 687         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
 688 };
 689
 690 static const struct nla_policy
 691 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
 692         [MPTCP_PM_ADDR_ATTR_FAMILY]     = { .type       = NLA_U16,      },
 693         [MPTCP_PM_ADDR_ATTR_ID]         = { .type       = NLA_U8,       },
 694         [MPTCP_PM_ADDR_ATTR_ADDR4]      = { .type       = NLA_U32,      },
 695         [MPTCP_PM_ADDR_ATTR_ADDR6]      =
 696                 NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
 697         [MPTCP_PM_ADDR_ATTR_PORT]       = { .type       = NLA_U16       },
 698         [MPTCP_PM_ADDR_ATTR_FLAGS]      = { .type       = NLA_U32       },
 699         [MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type       = NLA_S32       },
 700 };
 701
 702 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
 703         [MPTCP_PM_ATTR_ADDR]            =
 704                                         NLA_POLICY_NESTED(mptcp_pm_addr_policy),
 705         [MPTCP_PM_ATTR_RCV_ADD_ADDRS]   = { .type       = NLA_U32,      },
 706         [MPTCP_PM_ATTR_SUBFLOWS]        = { .type       = NLA_U32,      },
 707 };
 708
 709 static int mptcp_pm_family_to_addr(int family)
 710 {
 711 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 712         if (family == AF_INET6)
 713                 return MPTCP_PM_ADDR_ATTR_ADDR6;
 714 #endif
 715         return MPTCP_PM_ADDR_ATTR_ADDR4;
 716 }
 717
 718 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
 719                                bool require_family,
 720                                struct mptcp_pm_addr_entry *entry)
 721 {
 722         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
 723         int err, addr_addr;
 724
 725         if (!attr) {
 726                 GENL_SET_ERR_MSG(info, "missing address info");
 727                 return -EINVAL;
 728         }
 729
 730         /* no validation needed - was already done via nested policy */
 731         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
 732                                           mptcp_pm_addr_policy, info->extack);
 733         if (err)
 734                 return err;
 735
 736         memset(entry, 0, sizeof(*entry));
 737         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
 738                 if (!require_family)
 739                         goto skip_family;
 740
 741                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
 742                                     "missing family");
 743                 return -EINVAL;
 744         }
 745
 746         entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
 747         if (entry->addr.family != AF_INET
 748 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 749             && entry->addr.family != AF_INET6
 750 #endif
 751             ) {
 752                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
 753                                     "unknown address family");
 754                 return -EINVAL;
 755         }
 756         addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
 757         if (!tb[addr_addr]) {
 758                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
 759                                     "missing address data");
 760                 return -EINVAL;
 761         }
 762
 763 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 764         if (entry->addr.family == AF_INET6)
 765                 entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
 766         else
 767 #endif
 768                 entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
 769
 770 skip_family:
 771         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
 772                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
 773
 774                 entry->addr.ifindex = val;
 775         }
 776
 777         if (tb[MPTCP_PM_ADDR_ATTR_ID])
 778                 entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
 779
 780         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
 781                 entry->addr.flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
 782
 783         return 0;
 784 }
 785
 786 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
 787 {
 788         return net_generic(genl_info_net(info), pm_nl_pernet_id);
 789 }
 790
 791 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
 792 {
 793         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
 794         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 795         struct mptcp_pm_addr_entry addr, *entry;
 796         int ret;
 797
 798         ret = mptcp_pm_parse_addr(attr, info, true, &addr);
 799         if (ret < 0)
 800                 return ret;
 801
 802         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
 803         if (!entry) {
 804                 GENL_SET_ERR_MSG(info, "can't allocate addr");
 805                 return -ENOMEM;
 806         }
 807
 808         *entry = addr;
 809         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
 810         if (ret < 0) {
 811                 GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
 812                 kfree(entry);
 813                 return ret;
 814         }
 815
 816         return 0;
 817 }
 818
 819 static struct mptcp_pm_addr_entry *
 820 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 821 {
 822         struct mptcp_pm_addr_entry *entry;
 823
 824         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 825                 if (entry->addr.id == id)
 826                         return entry;
 827         }
 828         return NULL;
 829 }
 830
 831 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
 832                                       struct mptcp_addr_info *addr)
 833 {
 834         struct mptcp_pm_add_entry *entry;
 835
 836         entry = mptcp_pm_del_add_timer(msk, addr);
 837         if (entry) {
 838                 list_del(&entry->list);
 839                 kfree(entry);
 840                 return true;
 841         }
 842
 843         return false;
 844 }
 845
 846 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
 847                                       struct mptcp_addr_info *addr,
 848                                       bool force)
 849 {
 850         bool ret;
 851
 852         ret = remove_anno_list_by_saddr(msk, addr);
 853         if (ret || force) {
 854                 spin_lock_bh(&msk->pm.lock);
 855                 mptcp_pm_remove_addr(msk, addr->id);
 856                 spin_unlock_bh(&msk->pm.lock);
 857         }
 858         return ret;
 859 }
 860
 861 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
 862                                                    struct mptcp_addr_info *addr)
 863 {
 864         struct mptcp_sock *msk;
 865         long s_slot = 0, s_num = 0;
 866
 867         pr_debug("remove_id=%d", addr->id);
 868
 869         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
 870                 struct sock *sk = (struct sock *)msk;
 871                 bool remove_subflow;
 872
 873                 if (list_empty(&msk->conn_list)) {
 874                         mptcp_pm_remove_anno_addr(msk, addr, false);
 875                         goto next;
 876                 }
 877
 878                 lock_sock(sk);
 879                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
 880                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
 881                 if (remove_subflow)
 882                         mptcp_pm_remove_subflow(msk, addr->id);
 883                 release_sock(sk);
 884
 885 next:
 886                 sock_put(sk);
 887                 cond_resched();
 888         }
 889
 890         return 0;
 891 }
 892
 893 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
 894 {
 895         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
 896         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 897         struct mptcp_pm_addr_entry addr, *entry;
 898         int ret;
 899
 900         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
 901         if (ret < 0)
 902                 return ret;
 903
 904         spin_lock_bh(&pernet->lock);
 905         entry = __lookup_addr_by_id(pernet, addr.addr.id);
 906         if (!entry) {
 907                 GENL_SET_ERR_MSG(info, "address not found");
 908                 spin_unlock_bh(&pernet->lock);
 909                 return -EINVAL;
 910         }
 911         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)
 912                 pernet->add_addr_signal_max--;
 913         if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)
 914                 pernet->local_addr_max--;
 915
 916         pernet->addrs--;
 917         list_del_rcu(&entry->list);
 918         __clear_bit(entry->addr.id, pernet->id_bitmap);
 919         spin_unlock_bh(&pernet->lock);
 920
 921         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
 922         kfree_rcu(entry, rcu);
 923
 924         return ret;
 925 }
 926
 927 static void __flush_addrs(struct net *net, struct list_head *list)
 928 {
 929         while (!list_empty(list)) {
 930                 struct mptcp_pm_addr_entry *cur;
 931
 932                 cur = list_entry(list->next,
 933                                  struct mptcp_pm_addr_entry, list);
 934                 mptcp_nl_remove_subflow_and_signal_addr(net, &cur->addr);
 935                 list_del_rcu(&cur->list);
 936                 kfree_rcu(cur, rcu);
 937         }
 938 }
 939
 940 static void __reset_counters(struct pm_nl_pernet *pernet)
 941 {
 942         pernet->add_addr_signal_max = 0;
 943         pernet->add_addr_accept_max = 0;
 944         pernet->local_addr_max = 0;
 945         pernet->addrs = 0;
 946 }
 947
 948 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
 949 {
 950         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
 951         LIST_HEAD(free_list);
 952
 953         spin_lock_bh(&pernet->lock);
 954         list_splice_init(&pernet->local_addr_list, &free_list);
 955         __reset_counters(pernet);
 956         pernet->next_id = 1;
 957         bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
 958         spin_unlock_bh(&pernet->lock);
 959         __flush_addrs(sock_net(skb->sk), &free_list);
 960         return 0;
 961 }
 962
 963 static int mptcp_nl_fill_addr(struct sk_buff *skb,
 964                               struct mptcp_pm_addr_entry *entry)
 965 {
 966         struct mptcp_addr_info *addr = &entry->addr;
 967         struct nlattr *attr;
 968
 969         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
 970         if (!attr)
 971                 return -EMSGSIZE;
 972
 973         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
 974                 goto nla_put_failure;
 975         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
 976                 goto nla_put_failure;
 977         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->addr.flags))
 978                 goto nla_put_failure;
 979         if (entry->addr.ifindex &&
 980             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->addr.ifindex))
 981                 goto nla_put_failure;
 982
 983         if (addr->family == AF_INET &&
 984             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
 985                             addr->addr.s_addr))
 986                 goto nla_put_failure;
 987 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 988         else if (addr->family == AF_INET6 &&
 989                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
 990                 goto nla_put_failure;
 991 #endif
 992         nla_nest_end(skb, attr);
 993         return 0;
 994
 995 nla_put_failure:
 996         nla_nest_cancel(skb, attr);
 997         return -EMSGSIZE;
 998 }
 999
1000 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1001 {
1002         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1003         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1004         struct mptcp_pm_addr_entry addr, *entry;
1005         struct sk_buff *msg;
1006         void *reply;
1007         int ret;
1008
1009         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1010         if (ret < 0)
1011                 return ret;
1012
1013         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1014         if (!msg)
1015                 return -ENOMEM;
1016
1017         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1018                                   info->genlhdr->cmd);
1019         if (!reply) {
1020                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1021                 ret = -EMSGSIZE;
1022                 goto fail;
1023         }
1024
1025         spin_lock_bh(&pernet->lock);
1026         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1027         if (!entry) {
1028                 GENL_SET_ERR_MSG(info, "address not found");
1029                 ret = -EINVAL;
1030                 goto unlock_fail;
1031         }
1032
1033         ret = mptcp_nl_fill_addr(msg, entry);
1034         if (ret)
1035                 goto unlock_fail;
1036
1037         genlmsg_end(msg, reply);
1038         ret = genlmsg_reply(msg, info);
1039         spin_unlock_bh(&pernet->lock);
1040         return ret;
1041
1042 unlock_fail:
1043         spin_unlock_bh(&pernet->lock);
1044
1045 fail:
1046         nlmsg_free(msg);
1047         return ret;
1048 }
1049
1050 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1051                                    struct netlink_callback *cb)
1052 {
1053         struct net *net = sock_net(msg->sk);
1054         struct mptcp_pm_addr_entry *entry;
1055         struct pm_nl_pernet *pernet;
1056         int id = cb->args[0];
1057         void *hdr;
1058         int i;
1059
1060         pernet = net_generic(net, pm_nl_pernet_id);
1061
1062         spin_lock_bh(&pernet->lock);
1063         for (i = id; i < MAX_ADDR_ID + 1; i++) {
1064                 if (test_bit(i, pernet->id_bitmap)) {
1065                         entry = __lookup_addr_by_id(pernet, i);
1066                         if (!entry)
1067                                 break;
1068
1069                         if (entry->addr.id <= id)
1070                                 continue;
1071
1072                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1073                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1074                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1075                         if (!hdr)
1076                                 break;
1077
1078                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1079                                 genlmsg_cancel(msg, hdr);
1080                                 break;
1081                         }
1082
1083                         id = entry->addr.id;
1084                         genlmsg_end(msg, hdr);
1085                 }
1086         }
1087         spin_unlock_bh(&pernet->lock);
1088
1089         cb->args[0] = id;
1090         return msg->len;
1091 }
1092
1093 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1094 {
1095         struct nlattr *attr = info->attrs[id];
1096
1097         if (!attr)
1098                 return 0;
1099
1100         *limit = nla_get_u32(attr);
1101         if (*limit > MPTCP_PM_ADDR_MAX) {
1102                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1103                 return -EINVAL;
1104         }
1105         return 0;
1106 }
1107
1108 static int
1109 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1110 {
1111         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1112         unsigned int rcv_addrs, subflows;
1113         int ret;
1114
1115         spin_lock_bh(&pernet->lock);
1116         rcv_addrs = pernet->add_addr_accept_max;
1117         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1118         if (ret)
1119                 goto unlock;
1120
1121         subflows = pernet->subflows_max;
1122         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1123         if (ret)
1124                 goto unlock;
1125
1126         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1127         WRITE_ONCE(pernet->subflows_max, subflows);
1128
1129 unlock:
1130         spin_unlock_bh(&pernet->lock);
1131         return ret;
1132 }
1133
1134 static int
1135 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1136 {
1137         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1138         struct sk_buff *msg;
1139         void *reply;
1140
1141         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1142         if (!msg)
1143                 return -ENOMEM;
1144
1145         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1146                                   MPTCP_PM_CMD_GET_LIMITS);
1147         if (!reply)
1148                 goto fail;
1149
1150         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1151                         READ_ONCE(pernet->add_addr_accept_max)))
1152                 goto fail;
1153
1154         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1155                         READ_ONCE(pernet->subflows_max)))
1156                 goto fail;
1157
1158         genlmsg_end(msg, reply);
1159         return genlmsg_reply(msg, info);
1160
1161 fail:
1162         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1163         nlmsg_free(msg);
1164         return -EMSGSIZE;
1165 }
1166
1167 static const struct genl_small_ops mptcp_pm_ops[] = {
1168         {
1169                 .cmd    = MPTCP_PM_CMD_ADD_ADDR,
1170                 .doit   = mptcp_nl_cmd_add_addr,
1171                 .flags  = GENL_ADMIN_PERM,
1172         },
1173         {
1174                 .cmd    = MPTCP_PM_CMD_DEL_ADDR,
1175                 .doit   = mptcp_nl_cmd_del_addr,
1176                 .flags  = GENL_ADMIN_PERM,
1177         },
1178         {
1179                 .cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
1180                 .doit   = mptcp_nl_cmd_flush_addrs,
1181                 .flags  = GENL_ADMIN_PERM,
1182         },
1183         {
1184                 .cmd    = MPTCP_PM_CMD_GET_ADDR,
1185                 .doit   = mptcp_nl_cmd_get_addr,
1186                 .dumpit   = mptcp_nl_cmd_dump_addrs,
1187         },
1188         {
1189                 .cmd    = MPTCP_PM_CMD_SET_LIMITS,
1190                 .doit   = mptcp_nl_cmd_set_limits,
1191                 .flags  = GENL_ADMIN_PERM,
1192         },
1193         {
1194                 .cmd    = MPTCP_PM_CMD_GET_LIMITS,
1195                 .doit   = mptcp_nl_cmd_get_limits,
1196         },
1197 };
1198
1199 static struct genl_family mptcp_genl_family __ro_after_init = {
1200         .name           = MPTCP_PM_NAME,
1201         .version        = MPTCP_PM_VER,
1202         .maxattr        = MPTCP_PM_ATTR_MAX,
1203         .policy         = mptcp_pm_policy,
1204         .netnsok        = true,
1205         .module         = THIS_MODULE,
1206         .small_ops      = mptcp_pm_ops,
1207         .n_small_ops    = ARRAY_SIZE(mptcp_pm_ops),
1208         .mcgrps         = mptcp_pm_mcgrps,
1209         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
1210 };
1211
1212 static int __net_init pm_nl_init_net(struct net *net)
1213 {
1214         struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1215
1216         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
1217         __reset_counters(pernet);
1218         pernet->next_id = 1;
1219         bitmap_zero(pernet->id_bitmap, MAX_ADDR_ID + 1);
1220         spin_lock_init(&pernet->lock);
1221         return 0;
1222 }
1223
1224 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
1225 {
1226         struct net *net;
1227
1228         list_for_each_entry(net, net_list, exit_list) {
1229                 struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
1230
1231                 /* net is removed from namespace list, can't race with
1232                  * other modifiers
1233                  */
1234                 __flush_addrs(net, &pernet->local_addr_list);
1235         }
1236 }
1237
1238 static struct pernet_operations mptcp_pm_pernet_ops = {
1239         .init = pm_nl_init_net,
1240         .exit_batch = pm_nl_exit_net,
1241         .id = &pm_nl_pernet_id,
1242         .size = sizeof(struct pm_nl_pernet),
1243 };
1244
1245 void __init mptcp_pm_nl_init(void)
1246 {
1247         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
1248                 panic("Failed to register MPTCP PM pernet subsystem.\n");
1249
1250         if (genl_register_family(&mptcp_genl_family))
1251                 panic("Failed to register MPTCP PM netlink family\n");
1252 }