net/mptcp/pm_netlink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2020, Red Hat, Inc.
   5  */
   6
   7 #define pr_fmt(fmt) "MPTCP: " fmt
   8
   9 #include <linux/inet.h>
  10 #include <linux/kernel.h>
  11 #include <net/inet_common.h>
  12 #include <net/netns/generic.h>
  13 #include <net/mptcp.h>
  14
  15 #include "protocol.h"
  16 #include "mib.h"
  17
  18 static int pm_nl_pernet_id;
  19
  20 struct mptcp_pm_add_entry {
  21         struct list_head        list;
  22         struct mptcp_addr_info  addr;
  23         u8                      retrans_times;
  24         struct timer_list       add_timer;
  25         struct mptcp_sock       *sock;
  26 };
  27
  28 struct pm_nl_pernet {
  29         /* protects pernet updates */
  30         spinlock_t              lock;
  31         struct list_head        local_addr_list;
  32         unsigned int            addrs;
  33         unsigned int            stale_loss_cnt;
  34         unsigned int            add_addr_signal_max;
  35         unsigned int            add_addr_accept_max;
  36         unsigned int            local_addr_max;
  37         unsigned int            subflows_max;
  38         unsigned int            next_id;
  39         DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  40 };
  41
  42 #define MPTCP_PM_ADDR_MAX       8
  43 #define ADD_ADDR_RETRANS_MAX    3
  44
  45 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
  46 {
  47         return net_generic(net, pm_nl_pernet_id);
  48 }
  49
  50 static struct pm_nl_pernet *
  51 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
  52 {
  53         return pm_nl_get_pernet(sock_net((struct sock *)msk));
  54 }
  55
  56 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
  57                            const struct mptcp_addr_info *b, bool use_port)
  58 {
  59         bool addr_equals = false;
  60
  61         if (a->family == b->family) {
  62                 if (a->family == AF_INET)
  63                         addr_equals = a->addr.s_addr == b->addr.s_addr;
  64 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  65                 else
  66                         addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
  67         } else if (a->family == AF_INET) {
  68                 if (ipv6_addr_v4mapped(&b->addr6))
  69                         addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
  70         } else if (b->family == AF_INET) {
  71                 if (ipv6_addr_v4mapped(&a->addr6))
  72                         addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
  73 #endif
  74         }
  75
  76         if (!addr_equals)
  77                 return false;
  78         if (!use_port)
  79                 return true;
  80
  81         return a->port == b->port;
  82 }
  83
  84 void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr)
  85 {
  86         addr->family = skc->skc_family;
  87         addr->port = htons(skc->skc_num);
  88         if (addr->family == AF_INET)
  89                 addr->addr.s_addr = skc->skc_rcv_saddr;
  90 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  91         else if (addr->family == AF_INET6)
  92                 addr->addr6 = skc->skc_v6_rcv_saddr;
  93 #endif
  94 }
  95
  96 static void remote_address(const struct sock_common *skc,
  97                            struct mptcp_addr_info *addr)
  98 {
  99         addr->family = skc->skc_family;
 100         addr->port = skc->skc_dport;
 101         if (addr->family == AF_INET)
 102                 addr->addr.s_addr = skc->skc_daddr;
 103 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 104         else if (addr->family == AF_INET6)
 105                 addr->addr6 = skc->skc_v6_daddr;
 106 #endif
 107 }
 108
 109 static bool lookup_subflow_by_saddr(const struct list_head *list,
 110                                     const struct mptcp_addr_info *saddr)
 111 {
 112         struct mptcp_subflow_context *subflow;
 113         struct mptcp_addr_info cur;
 114         struct sock_common *skc;
 115
 116         list_for_each_entry(subflow, list, node) {
 117                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 118
 119                 mptcp_local_address(skc, &cur);
 120                 if (mptcp_addresses_equal(&cur, saddr, saddr->port))
 121                         return true;
 122         }
 123
 124         return false;
 125 }
 126
 127 static bool lookup_subflow_by_daddr(const struct list_head *list,
 128                                     const struct mptcp_addr_info *daddr)
 129 {
 130         struct mptcp_subflow_context *subflow;
 131         struct mptcp_addr_info cur;
 132         struct sock_common *skc;
 133
 134         list_for_each_entry(subflow, list, node) {
 135                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 136
 137                 remote_address(skc, &cur);
 138                 if (mptcp_addresses_equal(&cur, daddr, daddr->port))
 139                         return true;
 140         }
 141
 142         return false;
 143 }
 144
 145 static struct mptcp_pm_addr_entry *
 146 select_local_address(const struct pm_nl_pernet *pernet,
 147                      const struct mptcp_sock *msk)
 148 {
 149         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 150
 151         msk_owned_by_me(msk);
 152
 153         rcu_read_lock();
 154         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 155                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 156                         continue;
 157
 158                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 159                         continue;
 160
 161                 ret = entry;
 162                 break;
 163         }
 164         rcu_read_unlock();
 165         return ret;
 166 }
 167
 168 static struct mptcp_pm_addr_entry *
 169 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk)
 170 {
 171         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 172
 173         rcu_read_lock();
 174         /* do not keep any additional per socket state, just signal
 175          * the address list in order.
 176          * Note: removal from the local address list during the msk life-cycle
 177          * can lead to additional addresses not being announced.
 178          */
 179         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 180                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 181                         continue;
 182
 183                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
 184                         continue;
 185
 186                 ret = entry;
 187                 break;
 188         }
 189         rcu_read_unlock();
 190         return ret;
 191 }
 192
 193 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk)
 194 {
 195         const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 196
 197         return READ_ONCE(pernet->add_addr_signal_max);
 198 }
 199 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
 200
 201 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk)
 202 {
 203         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 204
 205         return READ_ONCE(pernet->add_addr_accept_max);
 206 }
 207 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
 208
 209 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk)
 210 {
 211         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 212
 213         return READ_ONCE(pernet->subflows_max);
 214 }
 215 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
 216
 217 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk)
 218 {
 219         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 220
 221         return READ_ONCE(pernet->local_addr_max);
 222 }
 223 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
 224
 225 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 226 {
 227         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 228
 229         if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
 230             (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
 231                                MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
 232                 WRITE_ONCE(msk->pm.work_pending, false);
 233                 return false;
 234         }
 235         return true;
 236 }
 237
 238 struct mptcp_pm_add_entry *
 239 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 240                                 const struct mptcp_addr_info *addr)
 241 {
 242         struct mptcp_pm_add_entry *entry;
 243
 244         lockdep_assert_held(&msk->pm.lock);
 245
 246         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 247                 if (mptcp_addresses_equal(&entry->addr, addr, true))
 248                         return entry;
 249         }
 250
 251         return NULL;
 252 }
 253
 254 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 255 {
 256         struct mptcp_pm_add_entry *entry;
 257         struct mptcp_addr_info saddr;
 258         bool ret = false;
 259
 260         mptcp_local_address((struct sock_common *)sk, &saddr);
 261
 262         spin_lock_bh(&msk->pm.lock);
 263         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 264                 if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
 265                         ret = true;
 266                         goto out;
 267                 }
 268         }
 269
 270 out:
 271         spin_unlock_bh(&msk->pm.lock);
 272         return ret;
 273 }
 274
 275 static void mptcp_pm_add_timer(struct timer_list *timer)
 276 {
 277         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 278         struct mptcp_sock *msk = entry->sock;
 279         struct sock *sk = (struct sock *)msk;
 280
 281         pr_debug("msk=%p", msk);
 282
 283         if (!msk)
 284                 return;
 285
 286         if (inet_sk_state_load(sk) == TCP_CLOSE)
 287                 return;
 288
 289         if (!entry->addr.id)
 290                 return;
 291
 292         if (mptcp_pm_should_add_signal_addr(msk)) {
 293                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 294                 goto out;
 295         }
 296
 297         spin_lock_bh(&msk->pm.lock);
 298
 299         if (!mptcp_pm_should_add_signal_addr(msk)) {
 300                 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
 301                 mptcp_pm_announce_addr(msk, &entry->addr, false);
 302                 mptcp_pm_add_addr_send_ack(msk);
 303                 entry->retrans_times++;
 304         }
 305
 306         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 307                 sk_reset_timer(sk, timer,
 308                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
 309
 310         spin_unlock_bh(&msk->pm.lock);
 311
 312         if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
 313                 mptcp_pm_subflow_established(msk);
 314
 315 out:
 316         __sock_put(sk);
 317 }
 318
 319 struct mptcp_pm_add_entry *
 320 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 321                        const struct mptcp_addr_info *addr, bool check_id)
 322 {
 323         struct mptcp_pm_add_entry *entry;
 324         struct sock *sk = (struct sock *)msk;
 325
 326         spin_lock_bh(&msk->pm.lock);
 327         entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 328         if (entry && (!check_id || entry->addr.id == addr->id))
 329                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 330         spin_unlock_bh(&msk->pm.lock);
 331
 332         if (entry && (!check_id || entry->addr.id == addr->id))
 333                 sk_stop_timer_sync(sk, &entry->add_timer);
 334
 335         return entry;
 336 }
 337
 338 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 339                               const struct mptcp_addr_info *addr)
 340 {
 341         struct mptcp_pm_add_entry *add_entry = NULL;
 342         struct sock *sk = (struct sock *)msk;
 343         struct net *net = sock_net(sk);
 344
 345         lockdep_assert_held(&msk->pm.lock);
 346
 347         add_entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 348
 349         if (add_entry) {
 350                 if (mptcp_pm_is_kernel(msk))
 351                         return false;
 352
 353                 sk_reset_timer(sk, &add_entry->add_timer,
 354                                jiffies + mptcp_get_add_addr_timeout(net));
 355                 return true;
 356         }
 357
 358         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
 359         if (!add_entry)
 360                 return false;
 361
 362         list_add(&add_entry->list, &msk->pm.anno_list);
 363
 364         add_entry->addr = *addr;
 365         add_entry->sock = msk;
 366         add_entry->retrans_times = 0;
 367
 368         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 369         sk_reset_timer(sk, &add_entry->add_timer,
 370                        jiffies + mptcp_get_add_addr_timeout(net));
 371
 372         return true;
 373 }
 374
 375 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 376 {
 377         struct mptcp_pm_add_entry *entry, *tmp;
 378         struct sock *sk = (struct sock *)msk;
 379         LIST_HEAD(free_list);
 380
 381         pr_debug("msk=%p", msk);
 382
 383         spin_lock_bh(&msk->pm.lock);
 384         list_splice_init(&msk->pm.anno_list, &free_list);
 385         spin_unlock_bh(&msk->pm.lock);
 386
 387         list_for_each_entry_safe(entry, tmp, &free_list, list) {
 388                 sk_stop_timer_sync(sk, &entry->add_timer);
 389                 kfree(entry);
 390         }
 391 }
 392
 393 /* Fill all the remote addresses into the array addrs[],
 394  * and return the array size.
 395  */
 396 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk,
 397                                               struct mptcp_addr_info *local,
 398                                               bool fullmesh,
 399                                               struct mptcp_addr_info *addrs)
 400 {
 401         bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
 402         struct sock *sk = (struct sock *)msk, *ssk;
 403         struct mptcp_subflow_context *subflow;
 404         struct mptcp_addr_info remote = { 0 };
 405         unsigned int subflows_max;
 406         int i = 0;
 407
 408         subflows_max = mptcp_pm_get_subflows_max(msk);
 409         remote_address((struct sock_common *)sk, &remote);
 410
 411         /* Non-fullmesh endpoint, fill in the single entry
 412          * corresponding to the primary MPC subflow remote address
 413          */
 414         if (!fullmesh) {
 415                 if (deny_id0)
 416                         return 0;
 417
 418                 if (!mptcp_pm_addr_families_match(sk, local, &remote))
 419                         return 0;
 420
 421                 msk->pm.subflows++;
 422                 addrs[i++] = remote;
 423         } else {
 424                 DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
 425
 426                 /* Forbid creation of new subflows matching existing
 427                  * ones, possibly already created by incoming ADD_ADDR
 428                  */
 429                 bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
 430                 mptcp_for_each_subflow(msk, subflow)
 431                         if (READ_ONCE(subflow->local_id) == local->id)
 432                                 __set_bit(subflow->remote_id, unavail_id);
 433
 434                 mptcp_for_each_subflow(msk, subflow) {
 435                         ssk = mptcp_subflow_tcp_sock(subflow);
 436                         remote_address((struct sock_common *)ssk, &addrs[i]);
 437                         addrs[i].id = READ_ONCE(subflow->remote_id);
 438                         if (deny_id0 && !addrs[i].id)
 439                                 continue;
 440
 441                         if (test_bit(addrs[i].id, unavail_id))
 442                                 continue;
 443
 444                         if (!mptcp_pm_addr_families_match(sk, local, &addrs[i]))
 445                                 continue;
 446
 447                         if (msk->pm.subflows < subflows_max) {
 448                                 /* forbid creating multiple address towards
 449                                  * this id
 450                                  */
 451                                 __set_bit(addrs[i].id, unavail_id);
 452                                 msk->pm.subflows++;
 453                                 i++;
 454                         }
 455                 }
 456         }
 457
 458         return i;
 459 }
 460
 461 static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
 462                                 bool prio, bool backup)
 463 {
 464         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 465         bool slow;
 466
 467         pr_debug("send ack for %s",
 468                  prio ? "mp_prio" : (mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr"));
 469
 470         slow = lock_sock_fast(ssk);
 471         if (prio) {
 472                 subflow->send_mp_prio = 1;
 473                 subflow->backup = backup;
 474                 subflow->request_bkup = backup;
 475         }
 476
 477         __mptcp_subflow_send_ack(ssk);
 478         unlock_sock_fast(ssk, slow);
 479 }
 480
 481 static void mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
 482                               bool prio, bool backup)
 483 {
 484         spin_unlock_bh(&msk->pm.lock);
 485         __mptcp_pm_send_ack(msk, subflow, prio, backup);
 486         spin_lock_bh(&msk->pm.lock);
 487 }
 488
 489 static struct mptcp_pm_addr_entry *
 490 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 491 {
 492         struct mptcp_pm_addr_entry *entry;
 493
 494         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 495                 if (entry->addr.id == id)
 496                         return entry;
 497         }
 498         return NULL;
 499 }
 500
 501 static struct mptcp_pm_addr_entry *
 502 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info)
 503 {
 504         struct mptcp_pm_addr_entry *entry;
 505
 506         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 507                 if (mptcp_addresses_equal(&entry->addr, info, entry->addr.port))
 508                         return entry;
 509         }
 510         return NULL;
 511 }
 512
 513 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 514 {
 515         struct sock *sk = (struct sock *)msk;
 516         struct mptcp_pm_addr_entry *local;
 517         unsigned int add_addr_signal_max;
 518         unsigned int local_addr_max;
 519         struct pm_nl_pernet *pernet;
 520         unsigned int subflows_max;
 521
 522         pernet = pm_nl_get_pernet(sock_net(sk));
 523
 524         add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
 525         local_addr_max = mptcp_pm_get_local_addr_max(msk);
 526         subflows_max = mptcp_pm_get_subflows_max(msk);
 527
 528         /* do lazy endpoint usage accounting for the MPC subflows */
 529         if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
 530                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
 531                 struct mptcp_pm_addr_entry *entry;
 532                 struct mptcp_addr_info mpc_addr;
 533                 bool backup = false;
 534
 535                 mptcp_local_address((struct sock_common *)msk->first, &mpc_addr);
 536                 rcu_read_lock();
 537                 entry = __lookup_addr(pernet, &mpc_addr);
 538                 if (entry) {
 539                         __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap);
 540                         msk->mpc_endpoint_id = entry->addr.id;
 541                         backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 542                 }
 543                 rcu_read_unlock();
 544
 545                 if (backup)
 546                         mptcp_pm_send_ack(msk, subflow, true, backup);
 547
 548                 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
 549         }
 550
 551         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
 552                  msk->pm.local_addr_used, local_addr_max,
 553                  msk->pm.add_addr_signaled, add_addr_signal_max,
 554                  msk->pm.subflows, subflows_max);
 555
 556         /* check first for announce */
 557         if (msk->pm.add_addr_signaled < add_addr_signal_max) {
 558                 local = select_signal_address(pernet, msk);
 559
 560                 /* due to racing events on both ends we can reach here while
 561                  * previous add address is still running: if we invoke now
 562                  * mptcp_pm_announce_addr(), that will fail and the
 563                  * corresponding id will be marked as used.
 564                  * Instead let the PM machinery reschedule us when the
 565                  * current address announce will be completed.
 566                  */
 567                 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
 568                         return;
 569
 570                 if (local) {
 571                         if (mptcp_pm_alloc_anno_list(msk, &local->addr)) {
 572                                 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 573                                 msk->pm.add_addr_signaled++;
 574                                 mptcp_pm_announce_addr(msk, &local->addr, false);
 575                                 mptcp_pm_nl_addr_send_ack(msk);
 576                         }
 577                 }
 578         }
 579
 580         /* check if should create a new subflow */
 581         while (msk->pm.local_addr_used < local_addr_max &&
 582                msk->pm.subflows < subflows_max) {
 583                 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 584                 bool fullmesh;
 585                 int i, nr;
 586
 587                 local = select_local_address(pernet, msk);
 588                 if (!local)
 589                         break;
 590
 591                 fullmesh = !!(local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
 592
 593                 msk->pm.local_addr_used++;
 594                 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 595                 nr = fill_remote_addresses_vec(msk, &local->addr, fullmesh, addrs);
 596                 if (nr == 0)
 597                         continue;
 598
 599                 spin_unlock_bh(&msk->pm.lock);
 600                 for (i = 0; i < nr; i++)
 601                         __mptcp_subflow_connect(sk, &local->addr, &addrs[i]);
 602                 spin_lock_bh(&msk->pm.lock);
 603         }
 604         mptcp_pm_nl_check_work_pending(msk);
 605 }
 606
 607 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 608 {
 609         mptcp_pm_create_subflow_or_signal_addr(msk);
 610 }
 611
 612 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 613 {
 614         mptcp_pm_create_subflow_or_signal_addr(msk);
 615 }
 616
 617 /* Fill all the local addresses into the array addrs[],
 618  * and return the array size.
 619  */
 620 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
 621                                              struct mptcp_addr_info *remote,
 622                                              struct mptcp_addr_info *addrs)
 623 {
 624         struct sock *sk = (struct sock *)msk;
 625         struct mptcp_pm_addr_entry *entry;
 626         struct pm_nl_pernet *pernet;
 627         unsigned int subflows_max;
 628         int i = 0;
 629
 630         pernet = pm_nl_get_pernet_from_msk(msk);
 631         subflows_max = mptcp_pm_get_subflows_max(msk);
 632
 633         rcu_read_lock();
 634         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 635                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
 636                         continue;
 637
 638                 if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote))
 639                         continue;
 640
 641                 if (msk->pm.subflows < subflows_max) {
 642                         msk->pm.subflows++;
 643                         addrs[i++] = entry->addr;
 644                 }
 645         }
 646         rcu_read_unlock();
 647
 648         /* If the array is empty, fill in the single
 649          * 'IPADDRANY' local address
 650          */
 651         if (!i) {
 652                 struct mptcp_addr_info local;
 653
 654                 memset(&local, 0, sizeof(local));
 655                 local.family =
 656 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 657                                remote->family == AF_INET6 &&
 658                                ipv6_addr_v4mapped(&remote->addr6) ? AF_INET :
 659 #endif
 660                                remote->family;
 661
 662                 if (!mptcp_pm_addr_families_match(sk, &local, remote))
 663                         return 0;
 664
 665                 msk->pm.subflows++;
 666                 addrs[i++] = local;
 667         }
 668
 669         return i;
 670 }
 671
 672 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 673 {
 674         struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 675         struct sock *sk = (struct sock *)msk;
 676         unsigned int add_addr_accept_max;
 677         struct mptcp_addr_info remote;
 678         unsigned int subflows_max;
 679         int i, nr;
 680
 681         add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
 682         subflows_max = mptcp_pm_get_subflows_max(msk);
 683
 684         pr_debug("accepted %d:%d remote family %d",
 685                  msk->pm.add_addr_accepted, add_addr_accept_max,
 686                  msk->pm.remote.family);
 687
 688         remote = msk->pm.remote;
 689         mptcp_pm_announce_addr(msk, &remote, true);
 690         mptcp_pm_nl_addr_send_ack(msk);
 691
 692         if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
 693                 return;
 694
 695         /* pick id 0 port, if none is provided the remote address */
 696         if (!remote.port)
 697                 remote.port = sk->sk_dport;
 698
 699         /* connect to the specified remote address, using whatever
 700          * local address the routing configuration will pick.
 701          */
 702         nr = fill_local_addresses_vec(msk, &remote, addrs);
 703         if (nr == 0)
 704                 return;
 705
 706         msk->pm.add_addr_accepted++;
 707         if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
 708             msk->pm.subflows >= subflows_max)
 709                 WRITE_ONCE(msk->pm.accept_addr, false);
 710
 711         spin_unlock_bh(&msk->pm.lock);
 712         for (i = 0; i < nr; i++)
 713                 __mptcp_subflow_connect(sk, &addrs[i], &remote);
 714         spin_lock_bh(&msk->pm.lock);
 715 }
 716
 717 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
 718 {
 719         struct mptcp_subflow_context *subflow;
 720
 721         msk_owned_by_me(msk);
 722         lockdep_assert_held(&msk->pm.lock);
 723
 724         if (!mptcp_pm_should_add_signal(msk) &&
 725             !mptcp_pm_should_rm_signal(msk))
 726                 return;
 727
 728         subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
 729         if (subflow)
 730                 mptcp_pm_send_ack(msk, subflow, false, false);
 731 }
 732
 733 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 734                                  struct mptcp_addr_info *addr,
 735                                  struct mptcp_addr_info *rem,
 736                                  u8 bkup)
 737 {
 738         struct mptcp_subflow_context *subflow;
 739
 740         pr_debug("bkup=%d", bkup);
 741
 742         mptcp_for_each_subflow(msk, subflow) {
 743                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 744                 struct mptcp_addr_info local, remote;
 745
 746                 mptcp_local_address((struct sock_common *)ssk, &local);
 747                 if (!mptcp_addresses_equal(&local, addr, addr->port))
 748                         continue;
 749
 750                 if (rem && rem->family != AF_UNSPEC) {
 751                         remote_address((struct sock_common *)ssk, &remote);
 752                         if (!mptcp_addresses_equal(&remote, rem, rem->port))
 753                                 continue;
 754                 }
 755
 756                 __mptcp_pm_send_ack(msk, subflow, true, bkup);
 757                 return 0;
 758         }
 759
 760         return -EINVAL;
 761 }
 762
 763 static bool mptcp_local_id_match(const struct mptcp_sock *msk, u8 local_id, u8 id)
 764 {
 765         return local_id == id || (!local_id && msk->mpc_endpoint_id == id);
 766 }
 767
 768 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 769                                            const struct mptcp_rm_list *rm_list,
 770                                            enum linux_mptcp_mib_field rm_type)
 771 {
 772         struct mptcp_subflow_context *subflow, *tmp;
 773         struct sock *sk = (struct sock *)msk;
 774         u8 i;
 775
 776         pr_debug("%s rm_list_nr %d",
 777                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
 778
 779         msk_owned_by_me(msk);
 780
 781         if (sk->sk_state == TCP_LISTEN)
 782                 return;
 783
 784         if (!rm_list->nr)
 785                 return;
 786
 787         if (list_empty(&msk->conn_list))
 788                 return;
 789
 790         for (i = 0; i < rm_list->nr; i++) {
 791                 u8 rm_id = rm_list->ids[i];
 792                 bool removed = false;
 793
 794                 mptcp_for_each_subflow_safe(msk, subflow, tmp) {
 795                         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 796                         u8 remote_id = READ_ONCE(subflow->remote_id);
 797                         int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 798                         u8 id = subflow_get_local_id(subflow);
 799
 800                         if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
 801                                 continue;
 802                         if (rm_type == MPTCP_MIB_RMSUBFLOW && !mptcp_local_id_match(msk, id, rm_id))
 803                                 continue;
 804
 805                         pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u",
 806                                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
 807                                  i, rm_id, id, remote_id, msk->mpc_endpoint_id);
 808                         spin_unlock_bh(&msk->pm.lock);
 809                         mptcp_subflow_shutdown(sk, ssk, how);
 810
 811                         /* the following takes care of updating the subflows counter */
 812                         mptcp_close_ssk(sk, ssk, subflow);
 813                         spin_lock_bh(&msk->pm.lock);
 814
 815                         removed = true;
 816                         __MPTCP_INC_STATS(sock_net(sk), rm_type);
 817                 }
 818                 if (rm_type == MPTCP_MIB_RMSUBFLOW)
 819                         __set_bit(rm_id ? rm_id : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap);
 820                 if (!removed)
 821                         continue;
 822
 823                 if (!mptcp_pm_is_kernel(msk))
 824                         continue;
 825
 826                 if (rm_type == MPTCP_MIB_RMADDR) {
 827                         msk->pm.add_addr_accepted--;
 828                         WRITE_ONCE(msk->pm.accept_addr, true);
 829                 } else if (rm_type == MPTCP_MIB_RMSUBFLOW) {
 830                         msk->pm.local_addr_used--;
 831                 }
 832         }
 833 }
 834
 835 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
 836 {
 837         mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
 838 }
 839
 840 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 841                                      const struct mptcp_rm_list *rm_list)
 842 {
 843         mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
 844 }
 845
 846 void mptcp_pm_nl_work(struct mptcp_sock *msk)
 847 {
 848         struct mptcp_pm_data *pm = &msk->pm;
 849
 850         msk_owned_by_me(msk);
 851
 852         if (!(pm->status & MPTCP_PM_WORK_MASK))
 853                 return;
 854
 855         spin_lock_bh(&msk->pm.lock);
 856
 857         pr_debug("msk=%p status=%x", msk, pm->status);
 858         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
 859                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 860                 mptcp_pm_nl_add_addr_received(msk);
 861         }
 862         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 863                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
 864                 mptcp_pm_nl_addr_send_ack(msk);
 865         }
 866         if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
 867                 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
 868                 mptcp_pm_nl_rm_addr_received(msk);
 869         }
 870         if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
 871                 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 872                 mptcp_pm_nl_fully_established(msk);
 873         }
 874         if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
 875                 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
 876                 mptcp_pm_nl_subflow_established(msk);
 877         }
 878
 879         spin_unlock_bh(&msk->pm.lock);
 880 }
 881
 882 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
 883 {
 884         return (entry->flags &
 885                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
 886                 MPTCP_PM_ADDR_FLAG_SIGNAL;
 887 }
 888
 889 /* caller must ensure the RCU grace period is already elapsed */
 890 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
 891 {
 892         if (entry->lsk)
 893                 sock_release(entry->lsk);
 894         kfree(entry);
 895 }
 896
 897 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 898                                              struct mptcp_pm_addr_entry *entry,
 899                                              bool needs_id)
 900 {
 901         struct mptcp_pm_addr_entry *cur, *del_entry = NULL;
 902         unsigned int addr_max;
 903         int ret = -EINVAL;
 904
 905         spin_lock_bh(&pernet->lock);
 906         /* to keep the code simple, don't do IDR-like allocation for address ID,
 907          * just bail when we exceed limits
 908          */
 909         if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
 910                 pernet->next_id = 1;
 911         if (pernet->addrs >= MPTCP_PM_ADDR_MAX) {
 912                 ret = -ERANGE;
 913                 goto out;
 914         }
 915         if (test_bit(entry->addr.id, pernet->id_bitmap)) {
 916                 ret = -EBUSY;
 917                 goto out;
 918         }
 919
 920         /* do not insert duplicate address, differentiate on port only
 921          * singled addresses
 922          */
 923         if (!address_use_port(entry))
 924                 entry->addr.port = 0;
 925         list_for_each_entry(cur, &pernet->local_addr_list, list) {
 926                 if (mptcp_addresses_equal(&cur->addr, &entry->addr,
 927                                           cur->addr.port || entry->addr.port)) {
 928                         /* allow replacing the exiting endpoint only if such
 929                          * endpoint is an implicit one and the user-space
 930                          * did not provide an endpoint id
 931                          */
 932                         if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) {
 933                                 ret = -EEXIST;
 934                                 goto out;
 935                         }
 936                         if (entry->addr.id)
 937                                 goto out;
 938
 939                         pernet->addrs--;
 940                         entry->addr.id = cur->addr.id;
 941                         list_del_rcu(&cur->list);
 942                         del_entry = cur;
 943                         break;
 944                 }
 945         }
 946
 947         if (!entry->addr.id && needs_id) {
 948 find_next:
 949                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
 950                                                     MPTCP_PM_MAX_ADDR_ID + 1,
 951                                                     pernet->next_id);
 952                 if (!entry->addr.id && pernet->next_id != 1) {
 953                         pernet->next_id = 1;
 954                         goto find_next;
 955                 }
 956         }
 957
 958         if (!entry->addr.id && needs_id)
 959                 goto out;
 960
 961         __set_bit(entry->addr.id, pernet->id_bitmap);
 962         if (entry->addr.id > pernet->next_id)
 963                 pernet->next_id = entry->addr.id;
 964
 965         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
 966                 addr_max = pernet->add_addr_signal_max;
 967                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
 968         }
 969         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
 970                 addr_max = pernet->local_addr_max;
 971                 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
 972         }
 973
 974         pernet->addrs++;
 975         if (!entry->addr.port)
 976                 list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
 977         else
 978                 list_add_rcu(&entry->list, &pernet->local_addr_list);
 979         ret = entry->addr.id;
 980
 981 out:
 982         spin_unlock_bh(&pernet->lock);
 983
 984         /* just replaced an existing entry, free it */
 985         if (del_entry) {
 986                 synchronize_rcu();
 987                 __mptcp_pm_release_addr_entry(del_entry);
 988         }
 989         return ret;
 990 }
 991
 992 static struct lock_class_key mptcp_slock_keys[2];
 993 static struct lock_class_key mptcp_keys[2];
 994
 995 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 996                                             struct mptcp_pm_addr_entry *entry)
 997 {
 998         bool is_ipv6 = sk->sk_family == AF_INET6;
 999         int addrlen = sizeof(struct sockaddr_in);
1000         struct sockaddr_storage addr;
1001         struct sock *newsk, *ssk;
1002         int backlog = 1024;
1003         int err;
1004
1005         err = sock_create_kern(sock_net(sk), entry->addr.family,
1006                                SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
1007         if (err)
1008                 return err;
1009
1010         newsk = entry->lsk->sk;
1011         if (!newsk)
1012                 return -EINVAL;
1013
1014         /* The subflow socket lock is acquired in a nested to the msk one
1015          * in several places, even by the TCP stack, and this msk is a kernel
1016          * socket: lockdep complains. Instead of propagating the _nested
1017          * modifiers in several places, re-init the lock class for the msk
1018          * socket to an mptcp specific one.
1019          */
1020         sock_lock_init_class_and_name(newsk,
1021                                       is_ipv6 ? "mlock-AF_INET6" : "mlock-AF_INET",
1022                                       &mptcp_slock_keys[is_ipv6],
1023                                       is_ipv6 ? "msk_lock-AF_INET6" : "msk_lock-AF_INET",
1024                                       &mptcp_keys[is_ipv6]);
1025
1026         lock_sock(newsk);
1027         ssk = __mptcp_nmpc_sk(mptcp_sk(newsk));
1028         release_sock(newsk);
1029         if (IS_ERR(ssk))
1030                 return PTR_ERR(ssk);
1031
1032         mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
1033 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1034         if (entry->addr.family == AF_INET6)
1035                 addrlen = sizeof(struct sockaddr_in6);
1036 #endif
1037         if (ssk->sk_family == AF_INET)
1038                 err = inet_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1039 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1040         else if (ssk->sk_family == AF_INET6)
1041                 err = inet6_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1042 #endif
1043         if (err)
1044                 return err;
1045
1046         /* We don't use mptcp_set_state() here because it needs to be called
1047          * under the msk socket lock. For the moment, that will not bring
1048          * anything more than only calling inet_sk_state_store(), because the
1049          * old status is known (TCP_CLOSE).
1050          */
1051         inet_sk_state_store(newsk, TCP_LISTEN);
1052         lock_sock(ssk);
1053         err = __inet_listen_sk(ssk, backlog);
1054         if (!err)
1055                 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED);
1056         release_sock(ssk);
1057         return err;
1058 }
1059
1060 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1061 {
1062         struct mptcp_pm_addr_entry *entry;
1063         struct pm_nl_pernet *pernet;
1064         int ret = -1;
1065
1066         pernet = pm_nl_get_pernet_from_msk(msk);
1067
1068         rcu_read_lock();
1069         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1070                 if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
1071                         ret = entry->addr.id;
1072                         break;
1073                 }
1074         }
1075         rcu_read_unlock();
1076         if (ret >= 0)
1077                 return ret;
1078
1079         /* address not found, add to local list */
1080         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1081         if (!entry)
1082                 return -ENOMEM;
1083
1084         entry->addr = *skc;
1085         entry->addr.id = 0;
1086         entry->addr.port = 0;
1087         entry->ifindex = 0;
1088         entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
1089         entry->lsk = NULL;
1090         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
1091         if (ret < 0)
1092                 kfree(entry);
1093
1094         return ret;
1095 }
1096
1097 #define MPTCP_PM_CMD_GRP_OFFSET       0
1098 #define MPTCP_PM_EV_GRP_OFFSET        1
1099
1100 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1101         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
1102         [MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
1103                                             .flags = GENL_MCAST_CAP_NET_ADMIN,
1104                                           },
1105 };
1106
1107 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1108 {
1109         struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1110         struct sock *sk = (struct sock *)msk;
1111         unsigned int active_max_loss_cnt;
1112         struct net *net = sock_net(sk);
1113         unsigned int stale_loss_cnt;
1114         bool slow;
1115
1116         stale_loss_cnt = mptcp_stale_loss_cnt(net);
1117         if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1118                 return;
1119
1120         /* look for another available subflow not in loss state */
1121         active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1122         mptcp_for_each_subflow(msk, iter) {
1123                 if (iter != subflow && mptcp_subflow_active(iter) &&
1124                     iter->stale_count < active_max_loss_cnt) {
1125                         /* we have some alternatives, try to mark this subflow as idle ...*/
1126                         slow = lock_sock_fast(ssk);
1127                         if (!tcp_rtx_and_write_queues_empty(ssk)) {
1128                                 subflow->stale = 1;
1129                                 __mptcp_retransmit_pending_data(sk);
1130                                 MPTCP_INC_STATS(net, MPTCP_MIB_SUBFLOWSTALE);
1131                         }
1132                         unlock_sock_fast(ssk, slow);
1133
1134                         /* always try to push the pending data regardless of re-injections:
1135                          * we can possibly use backup subflows now, and subflow selection
1136                          * is cheap under the msk socket lock
1137                          */
1138                         __mptcp_push_pending(sk, 0);
1139                         return;
1140                 }
1141         }
1142 }
1143
1144 static int mptcp_pm_family_to_addr(int family)
1145 {
1146 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1147         if (family == AF_INET6)
1148                 return MPTCP_PM_ADDR_ATTR_ADDR6;
1149 #endif
1150         return MPTCP_PM_ADDR_ATTR_ADDR4;
1151 }
1152
1153 static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
1154                                        const struct nlattr *attr,
1155                                        struct genl_info *info,
1156                                        struct mptcp_addr_info *addr,
1157                                        bool require_family)
1158 {
1159         int err, addr_addr;
1160
1161         if (!attr) {
1162                 GENL_SET_ERR_MSG(info, "missing address info");
1163                 return -EINVAL;
1164         }
1165
1166         /* no validation needed - was already done via nested policy */
1167         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1168                                           mptcp_pm_address_nl_policy, info->extack);
1169         if (err)
1170                 return err;
1171
1172         if (tb[MPTCP_PM_ADDR_ATTR_ID])
1173                 addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1174
1175         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1176                 if (!require_family)
1177                         return 0;
1178
1179                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1180                                     "missing family");
1181                 return -EINVAL;
1182         }
1183
1184         addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1185         if (addr->family != AF_INET
1186 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1187             && addr->family != AF_INET6
1188 #endif
1189             ) {
1190                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1191                                     "unknown address family");
1192                 return -EINVAL;
1193         }
1194         addr_addr = mptcp_pm_family_to_addr(addr->family);
1195         if (!tb[addr_addr]) {
1196                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1197                                     "missing address data");
1198                 return -EINVAL;
1199         }
1200
1201 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1202         if (addr->family == AF_INET6)
1203                 addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
1204         else
1205 #endif
1206                 addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1207
1208         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1209                 addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1210
1211         return 0;
1212 }
1213
1214 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1215                         struct mptcp_addr_info *addr)
1216 {
1217         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1218
1219         memset(addr, 0, sizeof(*addr));
1220
1221         return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
1222 }
1223
1224 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1225                          bool require_family,
1226                          struct mptcp_pm_addr_entry *entry)
1227 {
1228         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1229         int err;
1230
1231         memset(entry, 0, sizeof(*entry));
1232
1233         err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
1234         if (err)
1235                 return err;
1236
1237         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1238                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1239
1240                 entry->ifindex = val;
1241         }
1242
1243         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1244                 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1245
1246         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1247                 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1248
1249         return 0;
1250 }
1251
1252 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1253 {
1254         return pm_nl_get_pernet(genl_info_net(info));
1255 }
1256
1257 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
1258 {
1259         struct mptcp_sock *msk;
1260         long s_slot = 0, s_num = 0;
1261
1262         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1263                 struct sock *sk = (struct sock *)msk;
1264
1265                 if (!READ_ONCE(msk->fully_established) ||
1266                     mptcp_pm_is_userspace(msk))
1267                         goto next;
1268
1269                 lock_sock(sk);
1270                 spin_lock_bh(&msk->pm.lock);
1271                 mptcp_pm_create_subflow_or_signal_addr(msk);
1272                 spin_unlock_bh(&msk->pm.lock);
1273                 release_sock(sk);
1274
1275 next:
1276                 sock_put(sk);
1277                 cond_resched();
1278         }
1279
1280         return 0;
1281 }
1282
1283 static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr,
1284                                       struct genl_info *info)
1285 {
1286         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1287
1288         if (!nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1289                                          mptcp_pm_address_nl_policy, info->extack) &&
1290             tb[MPTCP_PM_ADDR_ATTR_ID])
1291                 return true;
1292         return false;
1293 }
1294
1295 int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
1296 {
1297         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1298         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1299         struct mptcp_pm_addr_entry addr, *entry;
1300         int ret;
1301
1302         ret = mptcp_pm_parse_entry(attr, info, true, &addr);
1303         if (ret < 0)
1304                 return ret;
1305
1306         if (addr.addr.port && !(addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1307                 GENL_SET_ERR_MSG(info, "flags must have signal when using port");
1308                 return -EINVAL;
1309         }
1310
1311         if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
1312             addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
1313                 GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
1314                 return -EINVAL;
1315         }
1316
1317         if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
1318                 GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
1319                 return -EINVAL;
1320         }
1321
1322         entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
1323         if (!entry) {
1324                 GENL_SET_ERR_MSG(info, "can't allocate addr");
1325                 return -ENOMEM;
1326         }
1327
1328         *entry = addr;
1329         if (entry->addr.port) {
1330                 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1331                 if (ret) {
1332                         GENL_SET_ERR_MSG_FMT(info, "create listen socket error: %d", ret);
1333                         goto out_free;
1334                 }
1335         }
1336         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry,
1337                                                 !mptcp_pm_has_addr_attr_id(attr, info));
1338         if (ret < 0) {
1339                 GENL_SET_ERR_MSG_FMT(info, "too many addresses or duplicate one: %d", ret);
1340                 goto out_free;
1341         }
1342
1343         mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1344         return 0;
1345
1346 out_free:
1347         __mptcp_pm_release_addr_entry(entry);
1348         return ret;
1349 }
1350
1351 int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
1352                                             u8 *flags, int *ifindex)
1353 {
1354         struct mptcp_pm_addr_entry *entry;
1355         struct sock *sk = (struct sock *)msk;
1356         struct net *net = sock_net(sk);
1357
1358         rcu_read_lock();
1359         entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
1360         if (entry) {
1361                 *flags = entry->flags;
1362                 *ifindex = entry->ifindex;
1363         }
1364         rcu_read_unlock();
1365
1366         return 0;
1367 }
1368
1369 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1370                                       const struct mptcp_addr_info *addr)
1371 {
1372         struct mptcp_pm_add_entry *entry;
1373
1374         entry = mptcp_pm_del_add_timer(msk, addr, false);
1375         if (entry) {
1376                 list_del(&entry->list);
1377                 kfree(entry);
1378                 return true;
1379         }
1380
1381         return false;
1382 }
1383
1384 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1385                                       const struct mptcp_addr_info *addr,
1386                                       bool force)
1387 {
1388         struct mptcp_rm_list list = { .nr = 0 };
1389         bool ret;
1390
1391         list.ids[list.nr++] = addr->id;
1392
1393         ret = remove_anno_list_by_saddr(msk, addr);
1394         if (ret || force) {
1395                 spin_lock_bh(&msk->pm.lock);
1396                 mptcp_pm_remove_addr(msk, &list);
1397                 spin_unlock_bh(&msk->pm.lock);
1398         }
1399         return ret;
1400 }
1401
1402 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1403                                                    const struct mptcp_pm_addr_entry *entry)
1404 {
1405         const struct mptcp_addr_info *addr = &entry->addr;
1406         struct mptcp_rm_list list = { .nr = 0 };
1407         long s_slot = 0, s_num = 0;
1408         struct mptcp_sock *msk;
1409
1410         pr_debug("remove_id=%d", addr->id);
1411
1412         list.ids[list.nr++] = addr->id;
1413
1414         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1415                 struct sock *sk = (struct sock *)msk;
1416                 bool remove_subflow;
1417
1418                 if (mptcp_pm_is_userspace(msk))
1419                         goto next;
1420
1421                 if (list_empty(&msk->conn_list)) {
1422                         mptcp_pm_remove_anno_addr(msk, addr, false);
1423                         goto next;
1424                 }
1425
1426                 lock_sock(sk);
1427                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1428                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
1429                                           !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
1430                 if (remove_subflow)
1431                         mptcp_pm_remove_subflow(msk, &list);
1432                 release_sock(sk);
1433
1434 next:
1435                 sock_put(sk);
1436                 cond_resched();
1437         }
1438
1439         return 0;
1440 }
1441
1442 static int mptcp_nl_remove_id_zero_address(struct net *net,
1443                                            struct mptcp_addr_info *addr)
1444 {
1445         struct mptcp_rm_list list = { .nr = 0 };
1446         long s_slot = 0, s_num = 0;
1447         struct mptcp_sock *msk;
1448
1449         list.ids[list.nr++] = 0;
1450
1451         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1452                 struct sock *sk = (struct sock *)msk;
1453                 struct mptcp_addr_info msk_local;
1454
1455                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1456                         goto next;
1457
1458                 mptcp_local_address((struct sock_common *)msk, &msk_local);
1459                 if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
1460                         goto next;
1461
1462                 lock_sock(sk);
1463                 spin_lock_bh(&msk->pm.lock);
1464                 mptcp_pm_remove_addr(msk, &list);
1465                 mptcp_pm_nl_rm_subflow_received(msk, &list);
1466                 spin_unlock_bh(&msk->pm.lock);
1467                 release_sock(sk);
1468
1469 next:
1470                 sock_put(sk);
1471                 cond_resched();
1472         }
1473
1474         return 0;
1475 }
1476
1477 int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info)
1478 {
1479         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1480         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1481         struct mptcp_pm_addr_entry addr, *entry;
1482         unsigned int addr_max;
1483         int ret;
1484
1485         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1486         if (ret < 0)
1487                 return ret;
1488
1489         /* the zero id address is special: the first address used by the msk
1490          * always gets such an id, so different subflows can have different zero
1491          * id addresses. Additionally zero id is not accounted for in id_bitmap.
1492          * Let's use an 'mptcp_rm_list' instead of the common remove code.
1493          */
1494         if (addr.addr.id == 0)
1495                 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1496
1497         spin_lock_bh(&pernet->lock);
1498         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1499         if (!entry) {
1500                 GENL_SET_ERR_MSG(info, "address not found");
1501                 spin_unlock_bh(&pernet->lock);
1502                 return -EINVAL;
1503         }
1504         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1505                 addr_max = pernet->add_addr_signal_max;
1506                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1507         }
1508         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1509                 addr_max = pernet->local_addr_max;
1510                 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1511         }
1512
1513         pernet->addrs--;
1514         list_del_rcu(&entry->list);
1515         __clear_bit(entry->addr.id, pernet->id_bitmap);
1516         spin_unlock_bh(&pernet->lock);
1517
1518         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry);
1519         synchronize_rcu();
1520         __mptcp_pm_release_addr_entry(entry);
1521
1522         return ret;
1523 }
1524
1525 void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
1526 {
1527         struct mptcp_rm_list alist = { .nr = 0 };
1528         struct mptcp_pm_addr_entry *entry;
1529
1530         list_for_each_entry(entry, rm_list, list) {
1531                 if ((remove_anno_list_by_saddr(msk, &entry->addr) ||
1532                      lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) &&
1533                     alist.nr < MPTCP_RM_IDS_MAX)
1534                         alist.ids[alist.nr++] = entry->addr.id;
1535         }
1536
1537         if (alist.nr) {
1538                 spin_lock_bh(&msk->pm.lock);
1539                 mptcp_pm_remove_addr(msk, &alist);
1540                 spin_unlock_bh(&msk->pm.lock);
1541         }
1542 }
1543
1544 static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1545                                                struct list_head *rm_list)
1546 {
1547         struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1548         struct mptcp_pm_addr_entry *entry;
1549
1550         list_for_each_entry(entry, rm_list, list) {
1551                 if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
1552                     slist.nr < MPTCP_RM_IDS_MAX)
1553                         slist.ids[slist.nr++] = entry->addr.id;
1554
1555                 if (remove_anno_list_by_saddr(msk, &entry->addr) &&
1556                     alist.nr < MPTCP_RM_IDS_MAX)
1557                         alist.ids[alist.nr++] = entry->addr.id;
1558         }
1559
1560         if (alist.nr) {
1561                 spin_lock_bh(&msk->pm.lock);
1562                 mptcp_pm_remove_addr(msk, &alist);
1563                 spin_unlock_bh(&msk->pm.lock);
1564         }
1565         if (slist.nr)
1566                 mptcp_pm_remove_subflow(msk, &slist);
1567 }
1568
1569 static void mptcp_nl_remove_addrs_list(struct net *net,
1570                                        struct list_head *rm_list)
1571 {
1572         long s_slot = 0, s_num = 0;
1573         struct mptcp_sock *msk;
1574
1575         if (list_empty(rm_list))
1576                 return;
1577
1578         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1579                 struct sock *sk = (struct sock *)msk;
1580
1581                 if (!mptcp_pm_is_userspace(msk)) {
1582                         lock_sock(sk);
1583                         mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1584                         release_sock(sk);
1585                 }
1586
1587                 sock_put(sk);
1588                 cond_resched();
1589         }
1590 }
1591
1592 /* caller must ensure the RCU grace period is already elapsed */
1593 static void __flush_addrs(struct list_head *list)
1594 {
1595         while (!list_empty(list)) {
1596                 struct mptcp_pm_addr_entry *cur;
1597
1598                 cur = list_entry(list->next,
1599                                  struct mptcp_pm_addr_entry, list);
1600                 list_del_rcu(&cur->list);
1601                 __mptcp_pm_release_addr_entry(cur);
1602         }
1603 }
1604
1605 static void __reset_counters(struct pm_nl_pernet *pernet)
1606 {
1607         WRITE_ONCE(pernet->add_addr_signal_max, 0);
1608         WRITE_ONCE(pernet->add_addr_accept_max, 0);
1609         WRITE_ONCE(pernet->local_addr_max, 0);
1610         pernet->addrs = 0;
1611 }
1612
1613 int mptcp_pm_nl_flush_addrs_doit(struct sk_buff *skb, struct genl_info *info)
1614 {
1615         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1616         LIST_HEAD(free_list);
1617
1618         spin_lock_bh(&pernet->lock);
1619         list_splice_init(&pernet->local_addr_list, &free_list);
1620         __reset_counters(pernet);
1621         pernet->next_id = 1;
1622         bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1623         spin_unlock_bh(&pernet->lock);
1624         mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1625         synchronize_rcu();
1626         __flush_addrs(&free_list);
1627         return 0;
1628 }
1629
1630 int mptcp_nl_fill_addr(struct sk_buff *skb,
1631                        struct mptcp_pm_addr_entry *entry)
1632 {
1633         struct mptcp_addr_info *addr = &entry->addr;
1634         struct nlattr *attr;
1635
1636         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1637         if (!attr)
1638                 return -EMSGSIZE;
1639
1640         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1641                 goto nla_put_failure;
1642         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1643                 goto nla_put_failure;
1644         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1645                 goto nla_put_failure;
1646         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1647                 goto nla_put_failure;
1648         if (entry->ifindex &&
1649             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1650                 goto nla_put_failure;
1651
1652         if (addr->family == AF_INET &&
1653             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1654                             addr->addr.s_addr))
1655                 goto nla_put_failure;
1656 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1657         else if (addr->family == AF_INET6 &&
1658                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1659                 goto nla_put_failure;
1660 #endif
1661         nla_nest_end(skb, attr);
1662         return 0;
1663
1664 nla_put_failure:
1665         nla_nest_cancel(skb, attr);
1666         return -EMSGSIZE;
1667 }
1668
1669 int mptcp_pm_nl_get_addr(struct sk_buff *skb, struct genl_info *info)
1670 {
1671         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1672         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1673         struct mptcp_pm_addr_entry addr, *entry;
1674         struct sk_buff *msg;
1675         void *reply;
1676         int ret;
1677
1678         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1679         if (ret < 0)
1680                 return ret;
1681
1682         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1683         if (!msg)
1684                 return -ENOMEM;
1685
1686         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1687                                   info->genlhdr->cmd);
1688         if (!reply) {
1689                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1690                 ret = -EMSGSIZE;
1691                 goto fail;
1692         }
1693
1694         spin_lock_bh(&pernet->lock);
1695         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1696         if (!entry) {
1697                 GENL_SET_ERR_MSG(info, "address not found");
1698                 ret = -EINVAL;
1699                 goto unlock_fail;
1700         }
1701
1702         ret = mptcp_nl_fill_addr(msg, entry);
1703         if (ret)
1704                 goto unlock_fail;
1705
1706         genlmsg_end(msg, reply);
1707         ret = genlmsg_reply(msg, info);
1708         spin_unlock_bh(&pernet->lock);
1709         return ret;
1710
1711 unlock_fail:
1712         spin_unlock_bh(&pernet->lock);
1713
1714 fail:
1715         nlmsg_free(msg);
1716         return ret;
1717 }
1718
1719 int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
1720 {
1721         return mptcp_pm_get_addr(skb, info);
1722 }
1723
1724 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
1725                           struct netlink_callback *cb)
1726 {
1727         struct net *net = sock_net(msg->sk);
1728         struct mptcp_pm_addr_entry *entry;
1729         struct pm_nl_pernet *pernet;
1730         int id = cb->args[0];
1731         void *hdr;
1732         int i;
1733
1734         pernet = pm_nl_get_pernet(net);
1735
1736         spin_lock_bh(&pernet->lock);
1737         for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1738                 if (test_bit(i, pernet->id_bitmap)) {
1739                         entry = __lookup_addr_by_id(pernet, i);
1740                         if (!entry)
1741                                 break;
1742
1743                         if (entry->addr.id <= id)
1744                                 continue;
1745
1746                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1747                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1748                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1749                         if (!hdr)
1750                                 break;
1751
1752                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1753                                 genlmsg_cancel(msg, hdr);
1754                                 break;
1755                         }
1756
1757                         id = entry->addr.id;
1758                         genlmsg_end(msg, hdr);
1759                 }
1760         }
1761         spin_unlock_bh(&pernet->lock);
1762
1763         cb->args[0] = id;
1764         return msg->len;
1765 }
1766
1767 int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
1768                                 struct netlink_callback *cb)
1769 {
1770         return mptcp_pm_dump_addr(msg, cb);
1771 }
1772
1773 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1774 {
1775         struct nlattr *attr = info->attrs[id];
1776
1777         if (!attr)
1778                 return 0;
1779
1780         *limit = nla_get_u32(attr);
1781         if (*limit > MPTCP_PM_ADDR_MAX) {
1782                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1783                 return -EINVAL;
1784         }
1785         return 0;
1786 }
1787
1788 int mptcp_pm_nl_set_limits_doit(struct sk_buff *skb, struct genl_info *info)
1789 {
1790         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1791         unsigned int rcv_addrs, subflows;
1792         int ret;
1793
1794         spin_lock_bh(&pernet->lock);
1795         rcv_addrs = pernet->add_addr_accept_max;
1796         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1797         if (ret)
1798                 goto unlock;
1799
1800         subflows = pernet->subflows_max;
1801         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1802         if (ret)
1803                 goto unlock;
1804
1805         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1806         WRITE_ONCE(pernet->subflows_max, subflows);
1807
1808 unlock:
1809         spin_unlock_bh(&pernet->lock);
1810         return ret;
1811 }
1812
1813 int mptcp_pm_nl_get_limits_doit(struct sk_buff *skb, struct genl_info *info)
1814 {
1815         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1816         struct sk_buff *msg;
1817         void *reply;
1818
1819         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1820         if (!msg)
1821                 return -ENOMEM;
1822
1823         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1824                                   MPTCP_PM_CMD_GET_LIMITS);
1825         if (!reply)
1826                 goto fail;
1827
1828         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1829                         READ_ONCE(pernet->add_addr_accept_max)))
1830                 goto fail;
1831
1832         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1833                         READ_ONCE(pernet->subflows_max)))
1834                 goto fail;
1835
1836         genlmsg_end(msg, reply);
1837         return genlmsg_reply(msg, info);
1838
1839 fail:
1840         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1841         nlmsg_free(msg);
1842         return -EMSGSIZE;
1843 }
1844
1845 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
1846                                  struct mptcp_addr_info *addr)
1847 {
1848         struct mptcp_rm_list list = { .nr = 0 };
1849
1850         list.ids[list.nr++] = addr->id;
1851
1852         spin_lock_bh(&msk->pm.lock);
1853         mptcp_pm_nl_rm_subflow_received(msk, &list);
1854         mptcp_pm_create_subflow_or_signal_addr(msk);
1855         spin_unlock_bh(&msk->pm.lock);
1856 }
1857
1858 static int mptcp_nl_set_flags(struct net *net,
1859                               struct mptcp_addr_info *addr,
1860                               u8 bkup, u8 changed)
1861 {
1862         long s_slot = 0, s_num = 0;
1863         struct mptcp_sock *msk;
1864         int ret = -EINVAL;
1865
1866         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1867                 struct sock *sk = (struct sock *)msk;
1868
1869                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1870                         goto next;
1871
1872                 lock_sock(sk);
1873                 if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
1874                         ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
1875                 if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
1876                         mptcp_pm_nl_fullmesh(msk, addr);
1877                 release_sock(sk);
1878
1879 next:
1880                 sock_put(sk);
1881                 cond_resched();
1882         }
1883
1884         return ret;
1885 }
1886
1887 int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
1888 {
1889         struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
1890         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1891         u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
1892                            MPTCP_PM_ADDR_FLAG_FULLMESH;
1893         struct net *net = sock_net(skb->sk);
1894         struct mptcp_pm_addr_entry *entry;
1895         struct pm_nl_pernet *pernet;
1896         u8 lookup_by_id = 0;
1897         u8 bkup = 0;
1898         int ret;
1899
1900         pernet = pm_nl_get_pernet(net);
1901
1902         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1903         if (ret < 0)
1904                 return ret;
1905
1906         if (addr.addr.family == AF_UNSPEC) {
1907                 lookup_by_id = 1;
1908                 if (!addr.addr.id) {
1909                         GENL_SET_ERR_MSG(info, "missing required inputs");
1910                         return -EOPNOTSUPP;
1911                 }
1912         }
1913
1914         if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1915                 bkup = 1;
1916
1917         spin_lock_bh(&pernet->lock);
1918         entry = lookup_by_id ? __lookup_addr_by_id(pernet, addr.addr.id) :
1919                                __lookup_addr(pernet, &addr.addr);
1920         if (!entry) {
1921                 spin_unlock_bh(&pernet->lock);
1922                 GENL_SET_ERR_MSG(info, "address not found");
1923                 return -EINVAL;
1924         }
1925         if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
1926             (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1927                 spin_unlock_bh(&pernet->lock);
1928                 GENL_SET_ERR_MSG(info, "invalid addr flags");
1929                 return -EINVAL;
1930         }
1931
1932         changed = (addr.flags ^ entry->flags) & mask;
1933         entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
1934         addr = *entry;
1935         spin_unlock_bh(&pernet->lock);
1936
1937         mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
1938         return 0;
1939 }
1940
1941 int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
1942 {
1943         return mptcp_pm_set_flags(skb, info);
1944 }
1945
1946 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1947 {
1948         genlmsg_multicast_netns(&mptcp_genl_family, net,
1949                                 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1950 }
1951
1952 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)
1953 {
1954         return genl_has_listeners(&mptcp_genl_family,
1955                                   sock_net((const struct sock *)msk),
1956                                   MPTCP_PM_EV_GRP_OFFSET);
1957 }
1958
1959 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1960 {
1961         const struct inet_sock *issk = inet_sk(ssk);
1962         const struct mptcp_subflow_context *sf;
1963
1964         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1965                 return -EMSGSIZE;
1966
1967         switch (ssk->sk_family) {
1968         case AF_INET:
1969                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1970                         return -EMSGSIZE;
1971                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1972                         return -EMSGSIZE;
1973                 break;
1974 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1975         case AF_INET6: {
1976                 const struct ipv6_pinfo *np = inet6_sk(ssk);
1977
1978                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1979                         return -EMSGSIZE;
1980                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1981                         return -EMSGSIZE;
1982                 break;
1983         }
1984 #endif
1985         default:
1986                 WARN_ON_ONCE(1);
1987                 return -EMSGSIZE;
1988         }
1989
1990         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1991                 return -EMSGSIZE;
1992         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
1993                 return -EMSGSIZE;
1994
1995         sf = mptcp_subflow_ctx(ssk);
1996         if (WARN_ON_ONCE(!sf))
1997                 return -EINVAL;
1998
1999         if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf)))
2000                 return -EMSGSIZE;
2001
2002         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
2003                 return -EMSGSIZE;
2004
2005         return 0;
2006 }
2007
2008 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
2009                                          const struct mptcp_sock *msk,
2010                                          const struct sock *ssk)
2011 {
2012         const struct sock *sk = (const struct sock *)msk;
2013         const struct mptcp_subflow_context *sf;
2014         u8 sk_err;
2015
2016         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2017                 return -EMSGSIZE;
2018
2019         if (mptcp_event_add_subflow(skb, ssk))
2020                 return -EMSGSIZE;
2021
2022         sf = mptcp_subflow_ctx(ssk);
2023         if (WARN_ON_ONCE(!sf))
2024                 return -EINVAL;
2025
2026         if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
2027                 return -EMSGSIZE;
2028
2029         if (ssk->sk_bound_dev_if &&
2030             nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
2031                 return -EMSGSIZE;
2032
2033         sk_err = READ_ONCE(ssk->sk_err);
2034         if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
2035             nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
2036                 return -EMSGSIZE;
2037
2038         return 0;
2039 }
2040
2041 static int mptcp_event_sub_established(struct sk_buff *skb,
2042                                        const struct mptcp_sock *msk,
2043                                        const struct sock *ssk)
2044 {
2045         return mptcp_event_put_token_and_ssk(skb, msk, ssk);
2046 }
2047
2048 static int mptcp_event_sub_closed(struct sk_buff *skb,
2049                                   const struct mptcp_sock *msk,
2050                                   const struct sock *ssk)
2051 {
2052         const struct mptcp_subflow_context *sf;
2053
2054         if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
2055                 return -EMSGSIZE;
2056
2057         sf = mptcp_subflow_ctx(ssk);
2058         if (!sf->reset_seen)
2059                 return 0;
2060
2061         if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
2062                 return -EMSGSIZE;
2063
2064         if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
2065                 return -EMSGSIZE;
2066
2067         return 0;
2068 }
2069
2070 static int mptcp_event_created(struct sk_buff *skb,
2071                                const struct mptcp_sock *msk,
2072                                const struct sock *ssk)
2073 {
2074         int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token));
2075
2076         if (err)
2077                 return err;
2078
2079         if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
2080                 return -EMSGSIZE;
2081
2082         return mptcp_event_add_subflow(skb, ssk);
2083 }
2084
2085 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
2086 {
2087         struct net *net = sock_net((const struct sock *)msk);
2088         struct nlmsghdr *nlh;
2089         struct sk_buff *skb;
2090
2091         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2092                 return;
2093
2094         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2095         if (!skb)
2096                 return;
2097
2098         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
2099         if (!nlh)
2100                 goto nla_put_failure;
2101
2102         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2103                 goto nla_put_failure;
2104
2105         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
2106                 goto nla_put_failure;
2107
2108         genlmsg_end(skb, nlh);
2109         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2110         return;
2111
2112 nla_put_failure:
2113         nlmsg_free(skb);
2114 }
2115
2116 void mptcp_event_addr_announced(const struct sock *ssk,
2117                                 const struct mptcp_addr_info *info)
2118 {
2119         struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
2120         struct mptcp_sock *msk = mptcp_sk(subflow->conn);
2121         struct net *net = sock_net(ssk);
2122         struct nlmsghdr *nlh;
2123         struct sk_buff *skb;
2124
2125         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2126                 return;
2127
2128         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2129         if (!skb)
2130                 return;
2131
2132         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
2133                           MPTCP_EVENT_ANNOUNCED);
2134         if (!nlh)
2135                 goto nla_put_failure;
2136
2137         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2138                 goto nla_put_failure;
2139
2140         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2141                 goto nla_put_failure;
2142
2143         if (nla_put_be16(skb, MPTCP_ATTR_DPORT,
2144                          info->port == 0 ?
2145                          inet_sk(ssk)->inet_dport :
2146                          info->port))
2147                 goto nla_put_failure;
2148
2149         switch (info->family) {
2150         case AF_INET:
2151                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2152                         goto nla_put_failure;
2153                 break;
2154 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2155         case AF_INET6:
2156                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2157                         goto nla_put_failure;
2158                 break;
2159 #endif
2160         default:
2161                 WARN_ON_ONCE(1);
2162                 goto nla_put_failure;
2163         }
2164
2165         genlmsg_end(skb, nlh);
2166         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2167         return;
2168
2169 nla_put_failure:
2170         nlmsg_free(skb);
2171 }
2172
2173 void mptcp_event_pm_listener(const struct sock *ssk,
2174                              enum mptcp_event_type event)
2175 {
2176         const struct inet_sock *issk = inet_sk(ssk);
2177         struct net *net = sock_net(ssk);
2178         struct nlmsghdr *nlh;
2179         struct sk_buff *skb;
2180
2181         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2182                 return;
2183
2184         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
2185         if (!skb)
2186                 return;
2187
2188         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event);
2189         if (!nlh)
2190                 goto nla_put_failure;
2191
2192         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2193                 goto nla_put_failure;
2194
2195         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2196                 goto nla_put_failure;
2197
2198         switch (ssk->sk_family) {
2199         case AF_INET:
2200                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2201                         goto nla_put_failure;
2202                 break;
2203 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2204         case AF_INET6: {
2205                 const struct ipv6_pinfo *np = inet6_sk(ssk);
2206
2207                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2208                         goto nla_put_failure;
2209                 break;
2210         }
2211 #endif
2212         default:
2213                 WARN_ON_ONCE(1);
2214                 goto nla_put_failure;
2215         }
2216
2217         genlmsg_end(skb, nlh);
2218         mptcp_nl_mcast_send(net, skb, GFP_KERNEL);
2219         return;
2220
2221 nla_put_failure:
2222         nlmsg_free(skb);
2223 }
2224
2225 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2226                  const struct sock *ssk, gfp_t gfp)
2227 {
2228         struct net *net = sock_net((const struct sock *)msk);
2229         struct nlmsghdr *nlh;
2230         struct sk_buff *skb;
2231
2232         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2233                 return;
2234
2235         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2236         if (!skb)
2237                 return;
2238
2239         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2240         if (!nlh)
2241                 goto nla_put_failure;
2242
2243         switch (type) {
2244         case MPTCP_EVENT_UNSPEC:
2245                 WARN_ON_ONCE(1);
2246                 break;
2247         case MPTCP_EVENT_CREATED:
2248         case MPTCP_EVENT_ESTABLISHED:
2249                 if (mptcp_event_created(skb, msk, ssk) < 0)
2250                         goto nla_put_failure;
2251                 break;
2252         case MPTCP_EVENT_CLOSED:
2253                 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)) < 0)
2254                         goto nla_put_failure;
2255                 break;
2256         case MPTCP_EVENT_ANNOUNCED:
2257         case MPTCP_EVENT_REMOVED:
2258                 /* call mptcp_event_addr_announced()/removed instead */
2259                 WARN_ON_ONCE(1);
2260                 break;
2261         case MPTCP_EVENT_SUB_ESTABLISHED:
2262         case MPTCP_EVENT_SUB_PRIORITY:
2263                 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2264                         goto nla_put_failure;
2265                 break;
2266         case MPTCP_EVENT_SUB_CLOSED:
2267                 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2268                         goto nla_put_failure;
2269                 break;
2270         case MPTCP_EVENT_LISTENER_CREATED:
2271         case MPTCP_EVENT_LISTENER_CLOSED:
2272                 break;
2273         }
2274
2275         genlmsg_end(skb, nlh);
2276         mptcp_nl_mcast_send(net, skb, gfp);
2277         return;
2278
2279 nla_put_failure:
2280         nlmsg_free(skb);
2281 }
2282
2283 struct genl_family mptcp_genl_family __ro_after_init = {
2284         .name           = MPTCP_PM_NAME,
2285         .version        = MPTCP_PM_VER,
2286         .netnsok        = true,
2287         .module         = THIS_MODULE,
2288         .ops            = mptcp_pm_nl_ops,
2289         .n_ops          = ARRAY_SIZE(mptcp_pm_nl_ops),
2290         .resv_start_op  = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1,
2291         .mcgrps         = mptcp_pm_mcgrps,
2292         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
2293 };
2294
2295 static int __net_init pm_nl_init_net(struct net *net)
2296 {
2297         struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2298
2299         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2300
2301         /* Cit. 2 subflows ought to be enough for anybody. */
2302         pernet->subflows_max = 2;
2303         pernet->next_id = 1;
2304         pernet->stale_loss_cnt = 4;
2305         spin_lock_init(&pernet->lock);
2306
2307         /* No need to initialize other pernet fields, the struct is zeroed at
2308          * allocation time.
2309          */
2310
2311         return 0;
2312 }
2313
2314 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2315 {
2316         struct net *net;
2317
2318         list_for_each_entry(net, net_list, exit_list) {
2319                 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2320
2321                 /* net is removed from namespace list, can't race with
2322                  * other modifiers, also netns core already waited for a
2323                  * RCU grace period.
2324                  */
2325                 __flush_addrs(&pernet->local_addr_list);
2326         }
2327 }
2328
2329 static struct pernet_operations mptcp_pm_pernet_ops = {
2330         .init = pm_nl_init_net,
2331         .exit_batch = pm_nl_exit_net,
2332         .id = &pm_nl_pernet_id,
2333         .size = sizeof(struct pm_nl_pernet),
2334 };
2335
2336 void __init mptcp_pm_nl_init(void)
2337 {
2338         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2339                 panic("Failed to register MPTCP PM pernet subsystem.\n");
2340
2341         if (genl_register_family(&mptcp_genl_family))
2342                 panic("Failed to register MPTCP PM netlink family\n");
2343 }