net/mptcp/pm_netlink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2020, Red Hat, Inc.
   5  */
   6
   7 #define pr_fmt(fmt) "MPTCP: " fmt
   8
   9 #include <linux/inet.h>
  10 #include <linux/kernel.h>
  11 #include <net/inet_common.h>
  12 #include <net/netns/generic.h>
  13 #include <net/mptcp.h>
  14
  15 #include "protocol.h"
  16 #include "mib.h"
  17 #include "mptcp_pm_gen.h"
  18
  19 static int pm_nl_pernet_id;
  20
  21 struct mptcp_pm_add_entry {
  22         struct list_head        list;
  23         struct mptcp_addr_info  addr;
  24         u8                      retrans_times;
  25         struct timer_list       add_timer;
  26         struct mptcp_sock       *sock;
  27 };
  28
  29 struct pm_nl_pernet {
  30         /* protects pernet updates */
  31         spinlock_t              lock;
  32         struct list_head        local_addr_list;
  33         unsigned int            addrs;
  34         unsigned int            stale_loss_cnt;
  35         unsigned int            add_addr_signal_max;
  36         unsigned int            add_addr_accept_max;
  37         unsigned int            local_addr_max;
  38         unsigned int            subflows_max;
  39         unsigned int            next_id;
  40         DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  41 };
  42
  43 #define MPTCP_PM_ADDR_MAX       8
  44 #define ADD_ADDR_RETRANS_MAX    3
  45
  46 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
  47 {
  48         return net_generic(net, pm_nl_pernet_id);
  49 }
  50
  51 static struct pm_nl_pernet *
  52 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
  53 {
  54         return pm_nl_get_pernet(sock_net((struct sock *)msk));
  55 }
  56
  57 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
  58                            const struct mptcp_addr_info *b, bool use_port)
  59 {
  60         bool addr_equals = false;
  61
  62         if (a->family == b->family) {
  63                 if (a->family == AF_INET)
  64                         addr_equals = a->addr.s_addr == b->addr.s_addr;
  65 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  66                 else
  67                         addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
  68         } else if (a->family == AF_INET) {
  69                 if (ipv6_addr_v4mapped(&b->addr6))
  70                         addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
  71         } else if (b->family == AF_INET) {
  72                 if (ipv6_addr_v4mapped(&a->addr6))
  73                         addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
  74 #endif
  75         }
  76
  77         if (!addr_equals)
  78                 return false;
  79         if (!use_port)
  80                 return true;
  81
  82         return a->port == b->port;
  83 }
  84
  85 void mptcp_local_address(const struct sock_common *skc, struct mptcp_addr_info *addr)
  86 {
  87         addr->family = skc->skc_family;
  88         addr->port = htons(skc->skc_num);
  89         if (addr->family == AF_INET)
  90                 addr->addr.s_addr = skc->skc_rcv_saddr;
  91 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  92         else if (addr->family == AF_INET6)
  93                 addr->addr6 = skc->skc_v6_rcv_saddr;
  94 #endif
  95 }
  96
  97 static void remote_address(const struct sock_common *skc,
  98                            struct mptcp_addr_info *addr)
  99 {
 100         addr->family = skc->skc_family;
 101         addr->port = skc->skc_dport;
 102         if (addr->family == AF_INET)
 103                 addr->addr.s_addr = skc->skc_daddr;
 104 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 105         else if (addr->family == AF_INET6)
 106                 addr->addr6 = skc->skc_v6_daddr;
 107 #endif
 108 }
 109
 110 static bool lookup_subflow_by_saddr(const struct list_head *list,
 111                                     const struct mptcp_addr_info *saddr)
 112 {
 113         struct mptcp_subflow_context *subflow;
 114         struct mptcp_addr_info cur;
 115         struct sock_common *skc;
 116
 117         list_for_each_entry(subflow, list, node) {
 118                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 119
 120                 mptcp_local_address(skc, &cur);
 121                 if (mptcp_addresses_equal(&cur, saddr, saddr->port))
 122                         return true;
 123         }
 124
 125         return false;
 126 }
 127
 128 static bool lookup_subflow_by_daddr(const struct list_head *list,
 129                                     const struct mptcp_addr_info *daddr)
 130 {
 131         struct mptcp_subflow_context *subflow;
 132         struct mptcp_addr_info cur;
 133         struct sock_common *skc;
 134
 135         list_for_each_entry(subflow, list, node) {
 136                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 137
 138                 remote_address(skc, &cur);
 139                 if (mptcp_addresses_equal(&cur, daddr, daddr->port))
 140                         return true;
 141         }
 142
 143         return false;
 144 }
 145
 146 static struct mptcp_pm_addr_entry *
 147 select_local_address(const struct pm_nl_pernet *pernet,
 148                      const struct mptcp_sock *msk)
 149 {
 150         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 151
 152         msk_owned_by_me(msk);
 153
 154         rcu_read_lock();
 155         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 156                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 157                         continue;
 158
 159                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 160                         continue;
 161
 162                 ret = entry;
 163                 break;
 164         }
 165         rcu_read_unlock();
 166         return ret;
 167 }
 168
 169 static struct mptcp_pm_addr_entry *
 170 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk)
 171 {
 172         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 173
 174         rcu_read_lock();
 175         /* do not keep any additional per socket state, just signal
 176          * the address list in order.
 177          * Note: removal from the local address list during the msk life-cycle
 178          * can lead to additional addresses not being announced.
 179          */
 180         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 181                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 182                         continue;
 183
 184                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
 185                         continue;
 186
 187                 ret = entry;
 188                 break;
 189         }
 190         rcu_read_unlock();
 191         return ret;
 192 }
 193
 194 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk)
 195 {
 196         const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 197
 198         return READ_ONCE(pernet->add_addr_signal_max);
 199 }
 200 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
 201
 202 unsigned int mptcp_pm_get_add_addr_accept_max(const struct mptcp_sock *msk)
 203 {
 204         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 205
 206         return READ_ONCE(pernet->add_addr_accept_max);
 207 }
 208 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
 209
 210 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk)
 211 {
 212         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 213
 214         return READ_ONCE(pernet->subflows_max);
 215 }
 216 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
 217
 218 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk)
 219 {
 220         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 221
 222         return READ_ONCE(pernet->local_addr_max);
 223 }
 224 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
 225
 226 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 227 {
 228         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 229
 230         if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
 231             (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
 232                                MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
 233                 WRITE_ONCE(msk->pm.work_pending, false);
 234                 return false;
 235         }
 236         return true;
 237 }
 238
 239 struct mptcp_pm_add_entry *
 240 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 241                                 const struct mptcp_addr_info *addr)
 242 {
 243         struct mptcp_pm_add_entry *entry;
 244
 245         lockdep_assert_held(&msk->pm.lock);
 246
 247         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 248                 if (mptcp_addresses_equal(&entry->addr, addr, true))
 249                         return entry;
 250         }
 251
 252         return NULL;
 253 }
 254
 255 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 256 {
 257         struct mptcp_pm_add_entry *entry;
 258         struct mptcp_addr_info saddr;
 259         bool ret = false;
 260
 261         mptcp_local_address((struct sock_common *)sk, &saddr);
 262
 263         spin_lock_bh(&msk->pm.lock);
 264         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 265                 if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
 266                         ret = true;
 267                         goto out;
 268                 }
 269         }
 270
 271 out:
 272         spin_unlock_bh(&msk->pm.lock);
 273         return ret;
 274 }
 275
 276 static void mptcp_pm_add_timer(struct timer_list *timer)
 277 {
 278         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 279         struct mptcp_sock *msk = entry->sock;
 280         struct sock *sk = (struct sock *)msk;
 281
 282         pr_debug("msk=%p", msk);
 283
 284         if (!msk)
 285                 return;
 286
 287         if (inet_sk_state_load(sk) == TCP_CLOSE)
 288                 return;
 289
 290         if (!entry->addr.id)
 291                 return;
 292
 293         if (mptcp_pm_should_add_signal_addr(msk)) {
 294                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 295                 goto out;
 296         }
 297
 298         spin_lock_bh(&msk->pm.lock);
 299
 300         if (!mptcp_pm_should_add_signal_addr(msk)) {
 301                 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
 302                 mptcp_pm_announce_addr(msk, &entry->addr, false);
 303                 mptcp_pm_add_addr_send_ack(msk);
 304                 entry->retrans_times++;
 305         }
 306
 307         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 308                 sk_reset_timer(sk, timer,
 309                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
 310
 311         spin_unlock_bh(&msk->pm.lock);
 312
 313         if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
 314                 mptcp_pm_subflow_established(msk);
 315
 316 out:
 317         __sock_put(sk);
 318 }
 319
 320 struct mptcp_pm_add_entry *
 321 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 322                        const struct mptcp_addr_info *addr, bool check_id)
 323 {
 324         struct mptcp_pm_add_entry *entry;
 325         struct sock *sk = (struct sock *)msk;
 326
 327         spin_lock_bh(&msk->pm.lock);
 328         entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 329         if (entry && (!check_id || entry->addr.id == addr->id))
 330                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 331         spin_unlock_bh(&msk->pm.lock);
 332
 333         if (entry && (!check_id || entry->addr.id == addr->id))
 334                 sk_stop_timer_sync(sk, &entry->add_timer);
 335
 336         return entry;
 337 }
 338
 339 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 340                               const struct mptcp_addr_info *addr)
 341 {
 342         struct mptcp_pm_add_entry *add_entry = NULL;
 343         struct sock *sk = (struct sock *)msk;
 344         struct net *net = sock_net(sk);
 345
 346         lockdep_assert_held(&msk->pm.lock);
 347
 348         add_entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 349
 350         if (add_entry) {
 351                 if (mptcp_pm_is_kernel(msk))
 352                         return false;
 353
 354                 sk_reset_timer(sk, &add_entry->add_timer,
 355                                jiffies + mptcp_get_add_addr_timeout(net));
 356                 return true;
 357         }
 358
 359         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
 360         if (!add_entry)
 361                 return false;
 362
 363         list_add(&add_entry->list, &msk->pm.anno_list);
 364
 365         add_entry->addr = *addr;
 366         add_entry->sock = msk;
 367         add_entry->retrans_times = 0;
 368
 369         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 370         sk_reset_timer(sk, &add_entry->add_timer,
 371                        jiffies + mptcp_get_add_addr_timeout(net));
 372
 373         return true;
 374 }
 375
 376 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 377 {
 378         struct mptcp_pm_add_entry *entry, *tmp;
 379         struct sock *sk = (struct sock *)msk;
 380         LIST_HEAD(free_list);
 381
 382         pr_debug("msk=%p", msk);
 383
 384         spin_lock_bh(&msk->pm.lock);
 385         list_splice_init(&msk->pm.anno_list, &free_list);
 386         spin_unlock_bh(&msk->pm.lock);
 387
 388         list_for_each_entry_safe(entry, tmp, &free_list, list) {
 389                 sk_stop_timer_sync(sk, &entry->add_timer);
 390                 kfree(entry);
 391         }
 392 }
 393
 394 /* Fill all the remote addresses into the array addrs[],
 395  * and return the array size.
 396  */
 397 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk,
 398                                               struct mptcp_addr_info *local,
 399                                               bool fullmesh,
 400                                               struct mptcp_addr_info *addrs)
 401 {
 402         bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
 403         struct sock *sk = (struct sock *)msk, *ssk;
 404         struct mptcp_subflow_context *subflow;
 405         struct mptcp_addr_info remote = { 0 };
 406         unsigned int subflows_max;
 407         int i = 0;
 408
 409         subflows_max = mptcp_pm_get_subflows_max(msk);
 410         remote_address((struct sock_common *)sk, &remote);
 411
 412         /* Non-fullmesh endpoint, fill in the single entry
 413          * corresponding to the primary MPC subflow remote address
 414          */
 415         if (!fullmesh) {
 416                 if (deny_id0)
 417                         return 0;
 418
 419                 if (!mptcp_pm_addr_families_match(sk, local, &remote))
 420                         return 0;
 421
 422                 msk->pm.subflows++;
 423                 addrs[i++] = remote;
 424         } else {
 425                 DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
 426
 427                 /* Forbid creation of new subflows matching existing
 428                  * ones, possibly already created by incoming ADD_ADDR
 429                  */
 430                 bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1);
 431                 mptcp_for_each_subflow(msk, subflow)
 432                         if (READ_ONCE(subflow->local_id) == local->id)
 433                                 __set_bit(subflow->remote_id, unavail_id);
 434
 435                 mptcp_for_each_subflow(msk, subflow) {
 436                         ssk = mptcp_subflow_tcp_sock(subflow);
 437                         remote_address((struct sock_common *)ssk, &addrs[i]);
 438                         addrs[i].id = READ_ONCE(subflow->remote_id);
 439                         if (deny_id0 && !addrs[i].id)
 440                                 continue;
 441
 442                         if (test_bit(addrs[i].id, unavail_id))
 443                                 continue;
 444
 445                         if (!mptcp_pm_addr_families_match(sk, local, &addrs[i]))
 446                                 continue;
 447
 448                         if (msk->pm.subflows < subflows_max) {
 449                                 /* forbid creating multiple address towards
 450                                  * this id
 451                                  */
 452                                 __set_bit(addrs[i].id, unavail_id);
 453                                 msk->pm.subflows++;
 454                                 i++;
 455                         }
 456                 }
 457         }
 458
 459         return i;
 460 }
 461
 462 static void __mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
 463                                 bool prio, bool backup)
 464 {
 465         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 466         bool slow;
 467
 468         pr_debug("send ack for %s",
 469                  prio ? "mp_prio" : (mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr"));
 470
 471         slow = lock_sock_fast(ssk);
 472         if (prio) {
 473                 subflow->send_mp_prio = 1;
 474                 subflow->backup = backup;
 475                 subflow->request_bkup = backup;
 476         }
 477
 478         __mptcp_subflow_send_ack(ssk);
 479         unlock_sock_fast(ssk, slow);
 480 }
 481
 482 static void mptcp_pm_send_ack(struct mptcp_sock *msk, struct mptcp_subflow_context *subflow,
 483                               bool prio, bool backup)
 484 {
 485         spin_unlock_bh(&msk->pm.lock);
 486         __mptcp_pm_send_ack(msk, subflow, prio, backup);
 487         spin_lock_bh(&msk->pm.lock);
 488 }
 489
 490 static struct mptcp_pm_addr_entry *
 491 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 492 {
 493         struct mptcp_pm_addr_entry *entry;
 494
 495         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 496                 if (entry->addr.id == id)
 497                         return entry;
 498         }
 499         return NULL;
 500 }
 501
 502 static struct mptcp_pm_addr_entry *
 503 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info)
 504 {
 505         struct mptcp_pm_addr_entry *entry;
 506
 507         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 508                 if (mptcp_addresses_equal(&entry->addr, info, entry->addr.port))
 509                         return entry;
 510         }
 511         return NULL;
 512 }
 513
 514 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 515 {
 516         struct sock *sk = (struct sock *)msk;
 517         struct mptcp_pm_addr_entry *local;
 518         unsigned int add_addr_signal_max;
 519         unsigned int local_addr_max;
 520         struct pm_nl_pernet *pernet;
 521         unsigned int subflows_max;
 522
 523         pernet = pm_nl_get_pernet(sock_net(sk));
 524
 525         add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
 526         local_addr_max = mptcp_pm_get_local_addr_max(msk);
 527         subflows_max = mptcp_pm_get_subflows_max(msk);
 528
 529         /* do lazy endpoint usage accounting for the MPC subflows */
 530         if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
 531                 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(msk->first);
 532                 struct mptcp_pm_addr_entry *entry;
 533                 struct mptcp_addr_info mpc_addr;
 534                 bool backup = false;
 535
 536                 mptcp_local_address((struct sock_common *)msk->first, &mpc_addr);
 537                 rcu_read_lock();
 538                 entry = __lookup_addr(pernet, &mpc_addr);
 539                 if (entry) {
 540                         __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap);
 541                         msk->mpc_endpoint_id = entry->addr.id;
 542                         backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP);
 543                 }
 544                 rcu_read_unlock();
 545
 546                 if (backup)
 547                         mptcp_pm_send_ack(msk, subflow, true, backup);
 548
 549                 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
 550         }
 551
 552         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
 553                  msk->pm.local_addr_used, local_addr_max,
 554                  msk->pm.add_addr_signaled, add_addr_signal_max,
 555                  msk->pm.subflows, subflows_max);
 556
 557         /* check first for announce */
 558         if (msk->pm.add_addr_signaled < add_addr_signal_max) {
 559                 local = select_signal_address(pernet, msk);
 560
 561                 /* due to racing events on both ends we can reach here while
 562                  * previous add address is still running: if we invoke now
 563                  * mptcp_pm_announce_addr(), that will fail and the
 564                  * corresponding id will be marked as used.
 565                  * Instead let the PM machinery reschedule us when the
 566                  * current address announce will be completed.
 567                  */
 568                 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
 569                         return;
 570
 571                 if (local) {
 572                         if (mptcp_pm_alloc_anno_list(msk, &local->addr)) {
 573                                 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 574                                 msk->pm.add_addr_signaled++;
 575                                 mptcp_pm_announce_addr(msk, &local->addr, false);
 576                                 mptcp_pm_nl_addr_send_ack(msk);
 577                         }
 578                 }
 579         }
 580
 581         /* check if should create a new subflow */
 582         while (msk->pm.local_addr_used < local_addr_max &&
 583                msk->pm.subflows < subflows_max) {
 584                 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 585                 bool fullmesh;
 586                 int i, nr;
 587
 588                 local = select_local_address(pernet, msk);
 589                 if (!local)
 590                         break;
 591
 592                 fullmesh = !!(local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
 593
 594                 msk->pm.local_addr_used++;
 595                 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 596                 nr = fill_remote_addresses_vec(msk, &local->addr, fullmesh, addrs);
 597                 if (nr == 0)
 598                         continue;
 599
 600                 spin_unlock_bh(&msk->pm.lock);
 601                 for (i = 0; i < nr; i++)
 602                         __mptcp_subflow_connect(sk, &local->addr, &addrs[i]);
 603                 spin_lock_bh(&msk->pm.lock);
 604         }
 605         mptcp_pm_nl_check_work_pending(msk);
 606 }
 607
 608 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 609 {
 610         mptcp_pm_create_subflow_or_signal_addr(msk);
 611 }
 612
 613 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 614 {
 615         mptcp_pm_create_subflow_or_signal_addr(msk);
 616 }
 617
 618 /* Fill all the local addresses into the array addrs[],
 619  * and return the array size.
 620  */
 621 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
 622                                              struct mptcp_addr_info *remote,
 623                                              struct mptcp_addr_info *addrs)
 624 {
 625         struct sock *sk = (struct sock *)msk;
 626         struct mptcp_pm_addr_entry *entry;
 627         struct pm_nl_pernet *pernet;
 628         unsigned int subflows_max;
 629         int i = 0;
 630
 631         pernet = pm_nl_get_pernet_from_msk(msk);
 632         subflows_max = mptcp_pm_get_subflows_max(msk);
 633
 634         rcu_read_lock();
 635         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 636                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
 637                         continue;
 638
 639                 if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote))
 640                         continue;
 641
 642                 if (msk->pm.subflows < subflows_max) {
 643                         msk->pm.subflows++;
 644                         addrs[i++] = entry->addr;
 645                 }
 646         }
 647         rcu_read_unlock();
 648
 649         /* If the array is empty, fill in the single
 650          * 'IPADDRANY' local address
 651          */
 652         if (!i) {
 653                 struct mptcp_addr_info local;
 654
 655                 memset(&local, 0, sizeof(local));
 656                 local.family =
 657 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 658                                remote->family == AF_INET6 &&
 659                                ipv6_addr_v4mapped(&remote->addr6) ? AF_INET :
 660 #endif
 661                                remote->family;
 662
 663                 if (!mptcp_pm_addr_families_match(sk, &local, remote))
 664                         return 0;
 665
 666                 msk->pm.subflows++;
 667                 addrs[i++] = local;
 668         }
 669
 670         return i;
 671 }
 672
 673 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 674 {
 675         struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 676         struct sock *sk = (struct sock *)msk;
 677         unsigned int add_addr_accept_max;
 678         struct mptcp_addr_info remote;
 679         unsigned int subflows_max;
 680         bool sf_created = false;
 681         int i, nr;
 682
 683         add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
 684         subflows_max = mptcp_pm_get_subflows_max(msk);
 685
 686         pr_debug("accepted %d:%d remote family %d",
 687                  msk->pm.add_addr_accepted, add_addr_accept_max,
 688                  msk->pm.remote.family);
 689
 690         remote = msk->pm.remote;
 691         mptcp_pm_announce_addr(msk, &remote, true);
 692         mptcp_pm_nl_addr_send_ack(msk);
 693
 694         if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
 695                 return;
 696
 697         /* pick id 0 port, if none is provided the remote address */
 698         if (!remote.port)
 699                 remote.port = sk->sk_dport;
 700
 701         /* connect to the specified remote address, using whatever
 702          * local address the routing configuration will pick.
 703          */
 704         nr = fill_local_addresses_vec(msk, &remote, addrs);
 705         if (nr == 0)
 706                 return;
 707
 708         spin_unlock_bh(&msk->pm.lock);
 709         for (i = 0; i < nr; i++)
 710                 if (__mptcp_subflow_connect(sk, &addrs[i], &remote) == 0)
 711                         sf_created = true;
 712         spin_lock_bh(&msk->pm.lock);
 713
 714         if (sf_created) {
 715                 msk->pm.add_addr_accepted++;
 716                 if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
 717                     msk->pm.subflows >= subflows_max)
 718                         WRITE_ONCE(msk->pm.accept_addr, false);
 719         }
 720 }
 721
 722 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
 723 {
 724         struct mptcp_subflow_context *subflow;
 725
 726         msk_owned_by_me(msk);
 727         lockdep_assert_held(&msk->pm.lock);
 728
 729         if (!mptcp_pm_should_add_signal(msk) &&
 730             !mptcp_pm_should_rm_signal(msk))
 731                 return;
 732
 733         subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
 734         if (subflow)
 735                 mptcp_pm_send_ack(msk, subflow, false, false);
 736 }
 737
 738 int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 739                                  struct mptcp_addr_info *addr,
 740                                  struct mptcp_addr_info *rem,
 741                                  u8 bkup)
 742 {
 743         struct mptcp_subflow_context *subflow;
 744
 745         pr_debug("bkup=%d", bkup);
 746
 747         mptcp_for_each_subflow(msk, subflow) {
 748                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 749                 struct mptcp_addr_info local, remote;
 750
 751                 mptcp_local_address((struct sock_common *)ssk, &local);
 752                 if (!mptcp_addresses_equal(&local, addr, addr->port))
 753                         continue;
 754
 755                 if (rem && rem->family != AF_UNSPEC) {
 756                         remote_address((struct sock_common *)ssk, &remote);
 757                         if (!mptcp_addresses_equal(&remote, rem, rem->port))
 758                                 continue;
 759                 }
 760
 761                 __mptcp_pm_send_ack(msk, subflow, true, bkup);
 762                 return 0;
 763         }
 764
 765         return -EINVAL;
 766 }
 767
 768 static bool mptcp_local_id_match(const struct mptcp_sock *msk, u8 local_id, u8 id)
 769 {
 770         return local_id == id || (!local_id && msk->mpc_endpoint_id == id);
 771 }
 772
 773 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 774                                            const struct mptcp_rm_list *rm_list,
 775                                            enum linux_mptcp_mib_field rm_type)
 776 {
 777         struct mptcp_subflow_context *subflow, *tmp;
 778         struct sock *sk = (struct sock *)msk;
 779         u8 i;
 780
 781         pr_debug("%s rm_list_nr %d",
 782                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
 783
 784         msk_owned_by_me(msk);
 785
 786         if (sk->sk_state == TCP_LISTEN)
 787                 return;
 788
 789         if (!rm_list->nr)
 790                 return;
 791
 792         if (list_empty(&msk->conn_list))
 793                 return;
 794
 795         for (i = 0; i < rm_list->nr; i++) {
 796                 u8 rm_id = rm_list->ids[i];
 797                 bool removed = false;
 798
 799                 mptcp_for_each_subflow_safe(msk, subflow, tmp) {
 800                         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 801                         u8 remote_id = READ_ONCE(subflow->remote_id);
 802                         int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 803                         u8 id = subflow_get_local_id(subflow);
 804
 805                         if (rm_type == MPTCP_MIB_RMADDR && remote_id != rm_id)
 806                                 continue;
 807                         if (rm_type == MPTCP_MIB_RMSUBFLOW && !mptcp_local_id_match(msk, id, rm_id))
 808                                 continue;
 809
 810                         pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u mpc_id=%u",
 811                                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
 812                                  i, rm_id, id, remote_id, msk->mpc_endpoint_id);
 813                         spin_unlock_bh(&msk->pm.lock);
 814                         mptcp_subflow_shutdown(sk, ssk, how);
 815
 816                         /* the following takes care of updating the subflows counter */
 817                         mptcp_close_ssk(sk, ssk, subflow);
 818                         spin_lock_bh(&msk->pm.lock);
 819
 820                         removed = true;
 821                         if (rm_type == MPTCP_MIB_RMSUBFLOW)
 822                                 __MPTCP_INC_STATS(sock_net(sk), rm_type);
 823                 }
 824                 if (rm_type == MPTCP_MIB_RMSUBFLOW)
 825                         __set_bit(rm_id ? rm_id : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap);
 826                 else if (rm_type == MPTCP_MIB_RMADDR)
 827                         __MPTCP_INC_STATS(sock_net(sk), rm_type);
 828                 if (!removed)
 829                         continue;
 830
 831                 if (!mptcp_pm_is_kernel(msk))
 832                         continue;
 833
 834                 if (rm_type == MPTCP_MIB_RMADDR) {
 835                         msk->pm.add_addr_accepted--;
 836                         WRITE_ONCE(msk->pm.accept_addr, true);
 837                 } else if (rm_type == MPTCP_MIB_RMSUBFLOW) {
 838                         msk->pm.local_addr_used--;
 839                 }
 840         }
 841 }
 842
 843 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
 844 {
 845         mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
 846 }
 847
 848 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 849                                      const struct mptcp_rm_list *rm_list)
 850 {
 851         mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
 852 }
 853
 854 void mptcp_pm_nl_work(struct mptcp_sock *msk)
 855 {
 856         struct mptcp_pm_data *pm = &msk->pm;
 857
 858         msk_owned_by_me(msk);
 859
 860         if (!(pm->status & MPTCP_PM_WORK_MASK))
 861                 return;
 862
 863         spin_lock_bh(&msk->pm.lock);
 864
 865         pr_debug("msk=%p status=%x", msk, pm->status);
 866         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
 867                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 868                 mptcp_pm_nl_add_addr_received(msk);
 869         }
 870         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 871                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
 872                 mptcp_pm_nl_addr_send_ack(msk);
 873         }
 874         if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
 875                 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
 876                 mptcp_pm_nl_rm_addr_received(msk);
 877         }
 878         if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
 879                 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 880                 mptcp_pm_nl_fully_established(msk);
 881         }
 882         if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
 883                 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
 884                 mptcp_pm_nl_subflow_established(msk);
 885         }
 886
 887         spin_unlock_bh(&msk->pm.lock);
 888 }
 889
 890 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
 891 {
 892         return (entry->flags &
 893                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
 894                 MPTCP_PM_ADDR_FLAG_SIGNAL;
 895 }
 896
 897 /* caller must ensure the RCU grace period is already elapsed */
 898 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
 899 {
 900         if (entry->lsk)
 901                 sock_release(entry->lsk);
 902         kfree(entry);
 903 }
 904
 905 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 906                                              struct mptcp_pm_addr_entry *entry,
 907                                              bool needs_id)
 908 {
 909         struct mptcp_pm_addr_entry *cur, *del_entry = NULL;
 910         unsigned int addr_max;
 911         int ret = -EINVAL;
 912
 913         spin_lock_bh(&pernet->lock);
 914         /* to keep the code simple, don't do IDR-like allocation for address ID,
 915          * just bail when we exceed limits
 916          */
 917         if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
 918                 pernet->next_id = 1;
 919         if (pernet->addrs >= MPTCP_PM_ADDR_MAX) {
 920                 ret = -ERANGE;
 921                 goto out;
 922         }
 923         if (test_bit(entry->addr.id, pernet->id_bitmap)) {
 924                 ret = -EBUSY;
 925                 goto out;
 926         }
 927
 928         /* do not insert duplicate address, differentiate on port only
 929          * singled addresses
 930          */
 931         if (!address_use_port(entry))
 932                 entry->addr.port = 0;
 933         list_for_each_entry(cur, &pernet->local_addr_list, list) {
 934                 if (mptcp_addresses_equal(&cur->addr, &entry->addr,
 935                                           cur->addr.port || entry->addr.port)) {
 936                         /* allow replacing the exiting endpoint only if such
 937                          * endpoint is an implicit one and the user-space
 938                          * did not provide an endpoint id
 939                          */
 940                         if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) {
 941                                 ret = -EEXIST;
 942                                 goto out;
 943                         }
 944                         if (entry->addr.id)
 945                                 goto out;
 946
 947                         pernet->addrs--;
 948                         entry->addr.id = cur->addr.id;
 949                         list_del_rcu(&cur->list);
 950                         del_entry = cur;
 951                         break;
 952                 }
 953         }
 954
 955         if (!entry->addr.id && needs_id) {
 956 find_next:
 957                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
 958                                                     MPTCP_PM_MAX_ADDR_ID + 1,
 959                                                     pernet->next_id);
 960                 if (!entry->addr.id && pernet->next_id != 1) {
 961                         pernet->next_id = 1;
 962                         goto find_next;
 963                 }
 964         }
 965
 966         if (!entry->addr.id && needs_id)
 967                 goto out;
 968
 969         __set_bit(entry->addr.id, pernet->id_bitmap);
 970         if (entry->addr.id > pernet->next_id)
 971                 pernet->next_id = entry->addr.id;
 972
 973         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
 974                 addr_max = pernet->add_addr_signal_max;
 975                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
 976         }
 977         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
 978                 addr_max = pernet->local_addr_max;
 979                 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
 980         }
 981
 982         pernet->addrs++;
 983         if (!entry->addr.port)
 984                 list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
 985         else
 986                 list_add_rcu(&entry->list, &pernet->local_addr_list);
 987         ret = entry->addr.id;
 988
 989 out:
 990         spin_unlock_bh(&pernet->lock);
 991
 992         /* just replaced an existing entry, free it */
 993         if (del_entry) {
 994                 synchronize_rcu();
 995                 __mptcp_pm_release_addr_entry(del_entry);
 996         }
 997         return ret;
 998 }
 999
1000 static struct lock_class_key mptcp_slock_keys[2];
1001 static struct lock_class_key mptcp_keys[2];
1002
1003 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
1004                                             struct mptcp_pm_addr_entry *entry)
1005 {
1006         bool is_ipv6 = sk->sk_family == AF_INET6;
1007         int addrlen = sizeof(struct sockaddr_in);
1008         struct sockaddr_storage addr;
1009         struct sock *newsk, *ssk;
1010         int backlog = 1024;
1011         int err;
1012
1013         err = sock_create_kern(sock_net(sk), entry->addr.family,
1014                                SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
1015         if (err)
1016                 return err;
1017
1018         newsk = entry->lsk->sk;
1019         if (!newsk)
1020                 return -EINVAL;
1021
1022         /* The subflow socket lock is acquired in a nested to the msk one
1023          * in several places, even by the TCP stack, and this msk is a kernel
1024          * socket: lockdep complains. Instead of propagating the _nested
1025          * modifiers in several places, re-init the lock class for the msk
1026          * socket to an mptcp specific one.
1027          */
1028         sock_lock_init_class_and_name(newsk,
1029                                       is_ipv6 ? "mlock-AF_INET6" : "mlock-AF_INET",
1030                                       &mptcp_slock_keys[is_ipv6],
1031                                       is_ipv6 ? "msk_lock-AF_INET6" : "msk_lock-AF_INET",
1032                                       &mptcp_keys[is_ipv6]);
1033
1034         lock_sock(newsk);
1035         ssk = __mptcp_nmpc_sk(mptcp_sk(newsk));
1036         release_sock(newsk);
1037         if (IS_ERR(ssk))
1038                 return PTR_ERR(ssk);
1039
1040         mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
1041 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1042         if (entry->addr.family == AF_INET6)
1043                 addrlen = sizeof(struct sockaddr_in6);
1044 #endif
1045         if (ssk->sk_family == AF_INET)
1046                 err = inet_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1047 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1048         else if (ssk->sk_family == AF_INET6)
1049                 err = inet6_bind_sk(ssk, (struct sockaddr *)&addr, addrlen);
1050 #endif
1051         if (err)
1052                 return err;
1053
1054         /* We don't use mptcp_set_state() here because it needs to be called
1055          * under the msk socket lock. For the moment, that will not bring
1056          * anything more than only calling inet_sk_state_store(), because the
1057          * old status is known (TCP_CLOSE).
1058          */
1059         inet_sk_state_store(newsk, TCP_LISTEN);
1060         lock_sock(ssk);
1061         err = __inet_listen_sk(ssk, backlog);
1062         if (!err)
1063                 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED);
1064         release_sock(ssk);
1065         return err;
1066 }
1067
1068 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct mptcp_addr_info *skc)
1069 {
1070         struct mptcp_pm_addr_entry *entry;
1071         struct pm_nl_pernet *pernet;
1072         int ret = -1;
1073
1074         pernet = pm_nl_get_pernet_from_msk(msk);
1075
1076         rcu_read_lock();
1077         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1078                 if (mptcp_addresses_equal(&entry->addr, skc, entry->addr.port)) {
1079                         ret = entry->addr.id;
1080                         break;
1081                 }
1082         }
1083         rcu_read_unlock();
1084         if (ret >= 0)
1085                 return ret;
1086
1087         /* address not found, add to local list */
1088         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1089         if (!entry)
1090                 return -ENOMEM;
1091
1092         entry->addr = *skc;
1093         entry->addr.id = 0;
1094         entry->addr.port = 0;
1095         entry->ifindex = 0;
1096         entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
1097         entry->lsk = NULL;
1098         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true);
1099         if (ret < 0)
1100                 kfree(entry);
1101
1102         return ret;
1103 }
1104
1105 #define MPTCP_PM_CMD_GRP_OFFSET       0
1106 #define MPTCP_PM_EV_GRP_OFFSET        1
1107
1108 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1109         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
1110         [MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
1111                                             .flags = GENL_MCAST_CAP_NET_ADMIN,
1112                                           },
1113 };
1114
1115 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1116 {
1117         struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1118         struct sock *sk = (struct sock *)msk;
1119         unsigned int active_max_loss_cnt;
1120         struct net *net = sock_net(sk);
1121         unsigned int stale_loss_cnt;
1122         bool slow;
1123
1124         stale_loss_cnt = mptcp_stale_loss_cnt(net);
1125         if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1126                 return;
1127
1128         /* look for another available subflow not in loss state */
1129         active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1130         mptcp_for_each_subflow(msk, iter) {
1131                 if (iter != subflow && mptcp_subflow_active(iter) &&
1132                     iter->stale_count < active_max_loss_cnt) {
1133                         /* we have some alternatives, try to mark this subflow as idle ...*/
1134                         slow = lock_sock_fast(ssk);
1135                         if (!tcp_rtx_and_write_queues_empty(ssk)) {
1136                                 subflow->stale = 1;
1137                                 __mptcp_retransmit_pending_data(sk);
1138                                 MPTCP_INC_STATS(net, MPTCP_MIB_SUBFLOWSTALE);
1139                         }
1140                         unlock_sock_fast(ssk, slow);
1141
1142                         /* always try to push the pending data regardless of re-injections:
1143                          * we can possibly use backup subflows now, and subflow selection
1144                          * is cheap under the msk socket lock
1145                          */
1146                         __mptcp_push_pending(sk, 0);
1147                         return;
1148                 }
1149         }
1150 }
1151
1152 static int mptcp_pm_family_to_addr(int family)
1153 {
1154 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1155         if (family == AF_INET6)
1156                 return MPTCP_PM_ADDR_ATTR_ADDR6;
1157 #endif
1158         return MPTCP_PM_ADDR_ATTR_ADDR4;
1159 }
1160
1161 static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
1162                                        const struct nlattr *attr,
1163                                        struct genl_info *info,
1164                                        struct mptcp_addr_info *addr,
1165                                        bool require_family)
1166 {
1167         int err, addr_addr;
1168
1169         if (!attr) {
1170                 GENL_SET_ERR_MSG(info, "missing address info");
1171                 return -EINVAL;
1172         }
1173
1174         /* no validation needed - was already done via nested policy */
1175         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1176                                           mptcp_pm_address_nl_policy, info->extack);
1177         if (err)
1178                 return err;
1179
1180         if (tb[MPTCP_PM_ADDR_ATTR_ID])
1181                 addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1182
1183         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1184                 if (!require_family)
1185                         return 0;
1186
1187                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1188                                     "missing family");
1189                 return -EINVAL;
1190         }
1191
1192         addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1193         if (addr->family != AF_INET
1194 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1195             && addr->family != AF_INET6
1196 #endif
1197             ) {
1198                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1199                                     "unknown address family");
1200                 return -EINVAL;
1201         }
1202         addr_addr = mptcp_pm_family_to_addr(addr->family);
1203         if (!tb[addr_addr]) {
1204                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1205                                     "missing address data");
1206                 return -EINVAL;
1207         }
1208
1209 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1210         if (addr->family == AF_INET6)
1211                 addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
1212         else
1213 #endif
1214                 addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1215
1216         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1217                 addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1218
1219         return 0;
1220 }
1221
1222 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1223                         struct mptcp_addr_info *addr)
1224 {
1225         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1226
1227         memset(addr, 0, sizeof(*addr));
1228
1229         return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
1230 }
1231
1232 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1233                          bool require_family,
1234                          struct mptcp_pm_addr_entry *entry)
1235 {
1236         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1237         int err;
1238
1239         memset(entry, 0, sizeof(*entry));
1240
1241         err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
1242         if (err)
1243                 return err;
1244
1245         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1246                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1247
1248                 entry->ifindex = val;
1249         }
1250
1251         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1252                 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1253
1254         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1255                 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1256
1257         return 0;
1258 }
1259
1260 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1261 {
1262         return pm_nl_get_pernet(genl_info_net(info));
1263 }
1264
1265 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
1266 {
1267         struct mptcp_sock *msk;
1268         long s_slot = 0, s_num = 0;
1269
1270         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1271                 struct sock *sk = (struct sock *)msk;
1272
1273                 if (!READ_ONCE(msk->fully_established) ||
1274                     mptcp_pm_is_userspace(msk))
1275                         goto next;
1276
1277                 lock_sock(sk);
1278                 spin_lock_bh(&msk->pm.lock);
1279                 mptcp_pm_create_subflow_or_signal_addr(msk);
1280                 spin_unlock_bh(&msk->pm.lock);
1281                 release_sock(sk);
1282
1283 next:
1284                 sock_put(sk);
1285                 cond_resched();
1286         }
1287
1288         return 0;
1289 }
1290
1291 static bool mptcp_pm_has_addr_attr_id(const struct nlattr *attr,
1292                                       struct genl_info *info)
1293 {
1294         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1295
1296         if (!nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1297                                          mptcp_pm_address_nl_policy, info->extack) &&
1298             tb[MPTCP_PM_ADDR_ATTR_ID])
1299                 return true;
1300         return false;
1301 }
1302
1303 int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info)
1304 {
1305         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1306         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1307         struct mptcp_pm_addr_entry addr, *entry;
1308         int ret;
1309
1310         ret = mptcp_pm_parse_entry(attr, info, true, &addr);
1311         if (ret < 0)
1312                 return ret;
1313
1314         if (addr.addr.port && !(addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1315                 GENL_SET_ERR_MSG(info, "flags must have signal when using port");
1316                 return -EINVAL;
1317         }
1318
1319         if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
1320             addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
1321                 GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
1322                 return -EINVAL;
1323         }
1324
1325         if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
1326                 GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
1327                 return -EINVAL;
1328         }
1329
1330         entry = kzalloc(sizeof(*entry), GFP_KERNEL_ACCOUNT);
1331         if (!entry) {
1332                 GENL_SET_ERR_MSG(info, "can't allocate addr");
1333                 return -ENOMEM;
1334         }
1335
1336         *entry = addr;
1337         if (entry->addr.port) {
1338                 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1339                 if (ret) {
1340                         GENL_SET_ERR_MSG_FMT(info, "create listen socket error: %d", ret);
1341                         goto out_free;
1342                 }
1343         }
1344         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry,
1345                                                 !mptcp_pm_has_addr_attr_id(attr, info));
1346         if (ret < 0) {
1347                 GENL_SET_ERR_MSG_FMT(info, "too many addresses or duplicate one: %d", ret);
1348                 goto out_free;
1349         }
1350
1351         mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1352         return 0;
1353
1354 out_free:
1355         __mptcp_pm_release_addr_entry(entry);
1356         return ret;
1357 }
1358
1359 int mptcp_pm_nl_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
1360                                             u8 *flags, int *ifindex)
1361 {
1362         struct mptcp_pm_addr_entry *entry;
1363         struct sock *sk = (struct sock *)msk;
1364         struct net *net = sock_net(sk);
1365
1366         rcu_read_lock();
1367         entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
1368         if (entry) {
1369                 *flags = entry->flags;
1370                 *ifindex = entry->ifindex;
1371         }
1372         rcu_read_unlock();
1373
1374         return 0;
1375 }
1376
1377 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1378                                       const struct mptcp_addr_info *addr)
1379 {
1380         struct mptcp_pm_add_entry *entry;
1381
1382         entry = mptcp_pm_del_add_timer(msk, addr, false);
1383         if (entry) {
1384                 list_del(&entry->list);
1385                 kfree(entry);
1386                 return true;
1387         }
1388
1389         return false;
1390 }
1391
1392 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1393                                       const struct mptcp_addr_info *addr,
1394                                       bool force)
1395 {
1396         struct mptcp_rm_list list = { .nr = 0 };
1397         bool ret;
1398
1399         list.ids[list.nr++] = addr->id;
1400
1401         ret = remove_anno_list_by_saddr(msk, addr);
1402         if (ret || force) {
1403                 spin_lock_bh(&msk->pm.lock);
1404                 mptcp_pm_remove_addr(msk, &list);
1405                 spin_unlock_bh(&msk->pm.lock);
1406         }
1407         return ret;
1408 }
1409
1410 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1411                                                    const struct mptcp_pm_addr_entry *entry)
1412 {
1413         const struct mptcp_addr_info *addr = &entry->addr;
1414         struct mptcp_rm_list list = { .nr = 0 };
1415         long s_slot = 0, s_num = 0;
1416         struct mptcp_sock *msk;
1417
1418         pr_debug("remove_id=%d", addr->id);
1419
1420         list.ids[list.nr++] = addr->id;
1421
1422         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1423                 struct sock *sk = (struct sock *)msk;
1424                 bool remove_subflow;
1425
1426                 if (mptcp_pm_is_userspace(msk))
1427                         goto next;
1428
1429                 if (list_empty(&msk->conn_list)) {
1430                         mptcp_pm_remove_anno_addr(msk, addr, false);
1431                         goto next;
1432                 }
1433
1434                 lock_sock(sk);
1435                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1436                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
1437                                           !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
1438                 if (remove_subflow)
1439                         mptcp_pm_remove_subflow(msk, &list);
1440                 release_sock(sk);
1441
1442 next:
1443                 sock_put(sk);
1444                 cond_resched();
1445         }
1446
1447         return 0;
1448 }
1449
1450 static int mptcp_nl_remove_id_zero_address(struct net *net,
1451                                            struct mptcp_addr_info *addr)
1452 {
1453         struct mptcp_rm_list list = { .nr = 0 };
1454         long s_slot = 0, s_num = 0;
1455         struct mptcp_sock *msk;
1456
1457         list.ids[list.nr++] = 0;
1458
1459         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1460                 struct sock *sk = (struct sock *)msk;
1461                 struct mptcp_addr_info msk_local;
1462
1463                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1464                         goto next;
1465
1466                 mptcp_local_address((struct sock_common *)msk, &msk_local);
1467                 if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
1468                         goto next;
1469
1470                 lock_sock(sk);
1471                 spin_lock_bh(&msk->pm.lock);
1472                 mptcp_pm_remove_addr(msk, &list);
1473                 mptcp_pm_nl_rm_subflow_received(msk, &list);
1474                 spin_unlock_bh(&msk->pm.lock);
1475                 release_sock(sk);
1476
1477 next:
1478                 sock_put(sk);
1479                 cond_resched();
1480         }
1481
1482         return 0;
1483 }
1484
1485 int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info)
1486 {
1487         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1488         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1489         struct mptcp_pm_addr_entry addr, *entry;
1490         unsigned int addr_max;
1491         int ret;
1492
1493         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1494         if (ret < 0)
1495                 return ret;
1496
1497         /* the zero id address is special: the first address used by the msk
1498          * always gets such an id, so different subflows can have different zero
1499          * id addresses. Additionally zero id is not accounted for in id_bitmap.
1500          * Let's use an 'mptcp_rm_list' instead of the common remove code.
1501          */
1502         if (addr.addr.id == 0)
1503                 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1504
1505         spin_lock_bh(&pernet->lock);
1506         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1507         if (!entry) {
1508                 GENL_SET_ERR_MSG(info, "address not found");
1509                 spin_unlock_bh(&pernet->lock);
1510                 return -EINVAL;
1511         }
1512         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1513                 addr_max = pernet->add_addr_signal_max;
1514                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1515         }
1516         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1517                 addr_max = pernet->local_addr_max;
1518                 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1519         }
1520
1521         pernet->addrs--;
1522         list_del_rcu(&entry->list);
1523         __clear_bit(entry->addr.id, pernet->id_bitmap);
1524         spin_unlock_bh(&pernet->lock);
1525
1526         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry);
1527         synchronize_rcu();
1528         __mptcp_pm_release_addr_entry(entry);
1529
1530         return ret;
1531 }
1532
1533 void mptcp_pm_remove_addrs(struct mptcp_sock *msk, struct list_head *rm_list)
1534 {
1535         struct mptcp_rm_list alist = { .nr = 0 };
1536         struct mptcp_pm_addr_entry *entry;
1537
1538         list_for_each_entry(entry, rm_list, list) {
1539                 if ((remove_anno_list_by_saddr(msk, &entry->addr) ||
1540                      lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) &&
1541                     alist.nr < MPTCP_RM_IDS_MAX)
1542                         alist.ids[alist.nr++] = entry->addr.id;
1543         }
1544
1545         if (alist.nr) {
1546                 spin_lock_bh(&msk->pm.lock);
1547                 mptcp_pm_remove_addr(msk, &alist);
1548                 spin_unlock_bh(&msk->pm.lock);
1549         }
1550 }
1551
1552 static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1553                                                struct list_head *rm_list)
1554 {
1555         struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1556         struct mptcp_pm_addr_entry *entry;
1557
1558         list_for_each_entry(entry, rm_list, list) {
1559                 if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
1560                     slist.nr < MPTCP_RM_IDS_MAX)
1561                         slist.ids[slist.nr++] = entry->addr.id;
1562
1563                 if (remove_anno_list_by_saddr(msk, &entry->addr) &&
1564                     alist.nr < MPTCP_RM_IDS_MAX)
1565                         alist.ids[alist.nr++] = entry->addr.id;
1566         }
1567
1568         if (alist.nr) {
1569                 spin_lock_bh(&msk->pm.lock);
1570                 mptcp_pm_remove_addr(msk, &alist);
1571                 spin_unlock_bh(&msk->pm.lock);
1572         }
1573         if (slist.nr)
1574                 mptcp_pm_remove_subflow(msk, &slist);
1575 }
1576
1577 static void mptcp_nl_remove_addrs_list(struct net *net,
1578                                        struct list_head *rm_list)
1579 {
1580         long s_slot = 0, s_num = 0;
1581         struct mptcp_sock *msk;
1582
1583         if (list_empty(rm_list))
1584                 return;
1585
1586         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1587                 struct sock *sk = (struct sock *)msk;
1588
1589                 if (!mptcp_pm_is_userspace(msk)) {
1590                         lock_sock(sk);
1591                         mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1592                         release_sock(sk);
1593                 }
1594
1595                 sock_put(sk);
1596                 cond_resched();
1597         }
1598 }
1599
1600 /* caller must ensure the RCU grace period is already elapsed */
1601 static void __flush_addrs(struct list_head *list)
1602 {
1603         while (!list_empty(list)) {
1604                 struct mptcp_pm_addr_entry *cur;
1605
1606                 cur = list_entry(list->next,
1607                                  struct mptcp_pm_addr_entry, list);
1608                 list_del_rcu(&cur->list);
1609                 __mptcp_pm_release_addr_entry(cur);
1610         }
1611 }
1612
1613 static void __reset_counters(struct pm_nl_pernet *pernet)
1614 {
1615         WRITE_ONCE(pernet->add_addr_signal_max, 0);
1616         WRITE_ONCE(pernet->add_addr_accept_max, 0);
1617         WRITE_ONCE(pernet->local_addr_max, 0);
1618         pernet->addrs = 0;
1619 }
1620
1621 int mptcp_pm_nl_flush_addrs_doit(struct sk_buff *skb, struct genl_info *info)
1622 {
1623         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1624         LIST_HEAD(free_list);
1625
1626         spin_lock_bh(&pernet->lock);
1627         list_splice_init(&pernet->local_addr_list, &free_list);
1628         __reset_counters(pernet);
1629         pernet->next_id = 1;
1630         bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1631         spin_unlock_bh(&pernet->lock);
1632         mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1633         synchronize_rcu();
1634         __flush_addrs(&free_list);
1635         return 0;
1636 }
1637
1638 int mptcp_nl_fill_addr(struct sk_buff *skb,
1639                        struct mptcp_pm_addr_entry *entry)
1640 {
1641         struct mptcp_addr_info *addr = &entry->addr;
1642         struct nlattr *attr;
1643
1644         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1645         if (!attr)
1646                 return -EMSGSIZE;
1647
1648         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1649                 goto nla_put_failure;
1650         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1651                 goto nla_put_failure;
1652         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1653                 goto nla_put_failure;
1654         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1655                 goto nla_put_failure;
1656         if (entry->ifindex &&
1657             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1658                 goto nla_put_failure;
1659
1660         if (addr->family == AF_INET &&
1661             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1662                             addr->addr.s_addr))
1663                 goto nla_put_failure;
1664 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1665         else if (addr->family == AF_INET6 &&
1666                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1667                 goto nla_put_failure;
1668 #endif
1669         nla_nest_end(skb, attr);
1670         return 0;
1671
1672 nla_put_failure:
1673         nla_nest_cancel(skb, attr);
1674         return -EMSGSIZE;
1675 }
1676
1677 int mptcp_pm_nl_get_addr(struct sk_buff *skb, struct genl_info *info)
1678 {
1679         struct nlattr *attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR];
1680         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1681         struct mptcp_pm_addr_entry addr, *entry;
1682         struct sk_buff *msg;
1683         void *reply;
1684         int ret;
1685
1686         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1687         if (ret < 0)
1688                 return ret;
1689
1690         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1691         if (!msg)
1692                 return -ENOMEM;
1693
1694         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1695                                   info->genlhdr->cmd);
1696         if (!reply) {
1697                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1698                 ret = -EMSGSIZE;
1699                 goto fail;
1700         }
1701
1702         spin_lock_bh(&pernet->lock);
1703         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1704         if (!entry) {
1705                 GENL_SET_ERR_MSG(info, "address not found");
1706                 ret = -EINVAL;
1707                 goto unlock_fail;
1708         }
1709
1710         ret = mptcp_nl_fill_addr(msg, entry);
1711         if (ret)
1712                 goto unlock_fail;
1713
1714         genlmsg_end(msg, reply);
1715         ret = genlmsg_reply(msg, info);
1716         spin_unlock_bh(&pernet->lock);
1717         return ret;
1718
1719 unlock_fail:
1720         spin_unlock_bh(&pernet->lock);
1721
1722 fail:
1723         nlmsg_free(msg);
1724         return ret;
1725 }
1726
1727 int mptcp_pm_nl_get_addr_doit(struct sk_buff *skb, struct genl_info *info)
1728 {
1729         return mptcp_pm_get_addr(skb, info);
1730 }
1731
1732 int mptcp_pm_nl_dump_addr(struct sk_buff *msg,
1733                           struct netlink_callback *cb)
1734 {
1735         struct net *net = sock_net(msg->sk);
1736         struct mptcp_pm_addr_entry *entry;
1737         struct pm_nl_pernet *pernet;
1738         int id = cb->args[0];
1739         void *hdr;
1740         int i;
1741
1742         pernet = pm_nl_get_pernet(net);
1743
1744         spin_lock_bh(&pernet->lock);
1745         for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1746                 if (test_bit(i, pernet->id_bitmap)) {
1747                         entry = __lookup_addr_by_id(pernet, i);
1748                         if (!entry)
1749                                 break;
1750
1751                         if (entry->addr.id <= id)
1752                                 continue;
1753
1754                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1755                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1756                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1757                         if (!hdr)
1758                                 break;
1759
1760                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1761                                 genlmsg_cancel(msg, hdr);
1762                                 break;
1763                         }
1764
1765                         id = entry->addr.id;
1766                         genlmsg_end(msg, hdr);
1767                 }
1768         }
1769         spin_unlock_bh(&pernet->lock);
1770
1771         cb->args[0] = id;
1772         return msg->len;
1773 }
1774
1775 int mptcp_pm_nl_get_addr_dumpit(struct sk_buff *msg,
1776                                 struct netlink_callback *cb)
1777 {
1778         return mptcp_pm_dump_addr(msg, cb);
1779 }
1780
1781 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1782 {
1783         struct nlattr *attr = info->attrs[id];
1784
1785         if (!attr)
1786                 return 0;
1787
1788         *limit = nla_get_u32(attr);
1789         if (*limit > MPTCP_PM_ADDR_MAX) {
1790                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1791                 return -EINVAL;
1792         }
1793         return 0;
1794 }
1795
1796 int mptcp_pm_nl_set_limits_doit(struct sk_buff *skb, struct genl_info *info)
1797 {
1798         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1799         unsigned int rcv_addrs, subflows;
1800         int ret;
1801
1802         spin_lock_bh(&pernet->lock);
1803         rcv_addrs = pernet->add_addr_accept_max;
1804         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1805         if (ret)
1806                 goto unlock;
1807
1808         subflows = pernet->subflows_max;
1809         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1810         if (ret)
1811                 goto unlock;
1812
1813         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1814         WRITE_ONCE(pernet->subflows_max, subflows);
1815
1816 unlock:
1817         spin_unlock_bh(&pernet->lock);
1818         return ret;
1819 }
1820
1821 int mptcp_pm_nl_get_limits_doit(struct sk_buff *skb, struct genl_info *info)
1822 {
1823         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1824         struct sk_buff *msg;
1825         void *reply;
1826
1827         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1828         if (!msg)
1829                 return -ENOMEM;
1830
1831         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1832                                   MPTCP_PM_CMD_GET_LIMITS);
1833         if (!reply)
1834                 goto fail;
1835
1836         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1837                         READ_ONCE(pernet->add_addr_accept_max)))
1838                 goto fail;
1839
1840         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1841                         READ_ONCE(pernet->subflows_max)))
1842                 goto fail;
1843
1844         genlmsg_end(msg, reply);
1845         return genlmsg_reply(msg, info);
1846
1847 fail:
1848         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1849         nlmsg_free(msg);
1850         return -EMSGSIZE;
1851 }
1852
1853 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
1854                                  struct mptcp_addr_info *addr)
1855 {
1856         struct mptcp_rm_list list = { .nr = 0 };
1857
1858         list.ids[list.nr++] = addr->id;
1859
1860         spin_lock_bh(&msk->pm.lock);
1861         mptcp_pm_nl_rm_subflow_received(msk, &list);
1862         mptcp_pm_create_subflow_or_signal_addr(msk);
1863         spin_unlock_bh(&msk->pm.lock);
1864 }
1865
1866 static int mptcp_nl_set_flags(struct net *net,
1867                               struct mptcp_addr_info *addr,
1868                               u8 bkup, u8 changed)
1869 {
1870         long s_slot = 0, s_num = 0;
1871         struct mptcp_sock *msk;
1872         int ret = -EINVAL;
1873
1874         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1875                 struct sock *sk = (struct sock *)msk;
1876
1877                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1878                         goto next;
1879
1880                 lock_sock(sk);
1881                 if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
1882                         ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, NULL, bkup);
1883                 if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
1884                         mptcp_pm_nl_fullmesh(msk, addr);
1885                 release_sock(sk);
1886
1887 next:
1888                 sock_put(sk);
1889                 cond_resched();
1890         }
1891
1892         return ret;
1893 }
1894
1895 int mptcp_pm_nl_set_flags(struct sk_buff *skb, struct genl_info *info)
1896 {
1897         struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, };
1898         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1899         u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
1900                            MPTCP_PM_ADDR_FLAG_FULLMESH;
1901         struct net *net = sock_net(skb->sk);
1902         struct mptcp_pm_addr_entry *entry;
1903         struct pm_nl_pernet *pernet;
1904         u8 lookup_by_id = 0;
1905         u8 bkup = 0;
1906         int ret;
1907
1908         pernet = pm_nl_get_pernet(net);
1909
1910         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1911         if (ret < 0)
1912                 return ret;
1913
1914         if (addr.addr.family == AF_UNSPEC) {
1915                 lookup_by_id = 1;
1916                 if (!addr.addr.id) {
1917                         GENL_SET_ERR_MSG(info, "missing required inputs");
1918                         return -EOPNOTSUPP;
1919                 }
1920         }
1921
1922         if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1923                 bkup = 1;
1924
1925         spin_lock_bh(&pernet->lock);
1926         entry = lookup_by_id ? __lookup_addr_by_id(pernet, addr.addr.id) :
1927                                __lookup_addr(pernet, &addr.addr);
1928         if (!entry) {
1929                 spin_unlock_bh(&pernet->lock);
1930                 GENL_SET_ERR_MSG(info, "address not found");
1931                 return -EINVAL;
1932         }
1933         if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
1934             (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1935                 spin_unlock_bh(&pernet->lock);
1936                 GENL_SET_ERR_MSG(info, "invalid addr flags");
1937                 return -EINVAL;
1938         }
1939
1940         changed = (addr.flags ^ entry->flags) & mask;
1941         entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
1942         addr = *entry;
1943         spin_unlock_bh(&pernet->lock);
1944
1945         mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
1946         return 0;
1947 }
1948
1949 int mptcp_pm_nl_set_flags_doit(struct sk_buff *skb, struct genl_info *info)
1950 {
1951         return mptcp_pm_set_flags(skb, info);
1952 }
1953
1954 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1955 {
1956         genlmsg_multicast_netns(&mptcp_genl_family, net,
1957                                 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1958 }
1959
1960 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)
1961 {
1962         return genl_has_listeners(&mptcp_genl_family,
1963                                   sock_net((const struct sock *)msk),
1964                                   MPTCP_PM_EV_GRP_OFFSET);
1965 }
1966
1967 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1968 {
1969         const struct inet_sock *issk = inet_sk(ssk);
1970         const struct mptcp_subflow_context *sf;
1971
1972         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1973                 return -EMSGSIZE;
1974
1975         switch (ssk->sk_family) {
1976         case AF_INET:
1977                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1978                         return -EMSGSIZE;
1979                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1980                         return -EMSGSIZE;
1981                 break;
1982 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1983         case AF_INET6: {
1984                 const struct ipv6_pinfo *np = inet6_sk(ssk);
1985
1986                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1987                         return -EMSGSIZE;
1988                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1989                         return -EMSGSIZE;
1990                 break;
1991         }
1992 #endif
1993         default:
1994                 WARN_ON_ONCE(1);
1995                 return -EMSGSIZE;
1996         }
1997
1998         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1999                 return -EMSGSIZE;
2000         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
2001                 return -EMSGSIZE;
2002
2003         sf = mptcp_subflow_ctx(ssk);
2004         if (WARN_ON_ONCE(!sf))
2005                 return -EINVAL;
2006
2007         if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, subflow_get_local_id(sf)))
2008                 return -EMSGSIZE;
2009
2010         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
2011                 return -EMSGSIZE;
2012
2013         return 0;
2014 }
2015
2016 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
2017                                          const struct mptcp_sock *msk,
2018                                          const struct sock *ssk)
2019 {
2020         const struct sock *sk = (const struct sock *)msk;
2021         const struct mptcp_subflow_context *sf;
2022         u8 sk_err;
2023
2024         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2025                 return -EMSGSIZE;
2026
2027         if (mptcp_event_add_subflow(skb, ssk))
2028                 return -EMSGSIZE;
2029
2030         sf = mptcp_subflow_ctx(ssk);
2031         if (WARN_ON_ONCE(!sf))
2032                 return -EINVAL;
2033
2034         if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
2035                 return -EMSGSIZE;
2036
2037         if (ssk->sk_bound_dev_if &&
2038             nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
2039                 return -EMSGSIZE;
2040
2041         sk_err = READ_ONCE(ssk->sk_err);
2042         if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
2043             nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
2044                 return -EMSGSIZE;
2045
2046         return 0;
2047 }
2048
2049 static int mptcp_event_sub_established(struct sk_buff *skb,
2050                                        const struct mptcp_sock *msk,
2051                                        const struct sock *ssk)
2052 {
2053         return mptcp_event_put_token_and_ssk(skb, msk, ssk);
2054 }
2055
2056 static int mptcp_event_sub_closed(struct sk_buff *skb,
2057                                   const struct mptcp_sock *msk,
2058                                   const struct sock *ssk)
2059 {
2060         const struct mptcp_subflow_context *sf;
2061
2062         if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
2063                 return -EMSGSIZE;
2064
2065         sf = mptcp_subflow_ctx(ssk);
2066         if (!sf->reset_seen)
2067                 return 0;
2068
2069         if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
2070                 return -EMSGSIZE;
2071
2072         if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
2073                 return -EMSGSIZE;
2074
2075         return 0;
2076 }
2077
2078 static int mptcp_event_created(struct sk_buff *skb,
2079                                const struct mptcp_sock *msk,
2080                                const struct sock *ssk)
2081 {
2082         int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token));
2083
2084         if (err)
2085                 return err;
2086
2087         if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
2088                 return -EMSGSIZE;
2089
2090         return mptcp_event_add_subflow(skb, ssk);
2091 }
2092
2093 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
2094 {
2095         struct net *net = sock_net((const struct sock *)msk);
2096         struct nlmsghdr *nlh;
2097         struct sk_buff *skb;
2098
2099         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2100                 return;
2101
2102         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2103         if (!skb)
2104                 return;
2105
2106         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
2107         if (!nlh)
2108                 goto nla_put_failure;
2109
2110         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2111                 goto nla_put_failure;
2112
2113         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
2114                 goto nla_put_failure;
2115
2116         genlmsg_end(skb, nlh);
2117         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2118         return;
2119
2120 nla_put_failure:
2121         nlmsg_free(skb);
2122 }
2123
2124 void mptcp_event_addr_announced(const struct sock *ssk,
2125                                 const struct mptcp_addr_info *info)
2126 {
2127         struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
2128         struct mptcp_sock *msk = mptcp_sk(subflow->conn);
2129         struct net *net = sock_net(ssk);
2130         struct nlmsghdr *nlh;
2131         struct sk_buff *skb;
2132
2133         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2134                 return;
2135
2136         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2137         if (!skb)
2138                 return;
2139
2140         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
2141                           MPTCP_EVENT_ANNOUNCED);
2142         if (!nlh)
2143                 goto nla_put_failure;
2144
2145         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)))
2146                 goto nla_put_failure;
2147
2148         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2149                 goto nla_put_failure;
2150
2151         if (nla_put_be16(skb, MPTCP_ATTR_DPORT,
2152                          info->port == 0 ?
2153                          inet_sk(ssk)->inet_dport :
2154                          info->port))
2155                 goto nla_put_failure;
2156
2157         switch (info->family) {
2158         case AF_INET:
2159                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2160                         goto nla_put_failure;
2161                 break;
2162 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2163         case AF_INET6:
2164                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2165                         goto nla_put_failure;
2166                 break;
2167 #endif
2168         default:
2169                 WARN_ON_ONCE(1);
2170                 goto nla_put_failure;
2171         }
2172
2173         genlmsg_end(skb, nlh);
2174         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2175         return;
2176
2177 nla_put_failure:
2178         nlmsg_free(skb);
2179 }
2180
2181 void mptcp_event_pm_listener(const struct sock *ssk,
2182                              enum mptcp_event_type event)
2183 {
2184         const struct inet_sock *issk = inet_sk(ssk);
2185         struct net *net = sock_net(ssk);
2186         struct nlmsghdr *nlh;
2187         struct sk_buff *skb;
2188
2189         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2190                 return;
2191
2192         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
2193         if (!skb)
2194                 return;
2195
2196         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, event);
2197         if (!nlh)
2198                 goto nla_put_failure;
2199
2200         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
2201                 goto nla_put_failure;
2202
2203         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
2204                 goto nla_put_failure;
2205
2206         switch (ssk->sk_family) {
2207         case AF_INET:
2208                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
2209                         goto nla_put_failure;
2210                 break;
2211 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2212         case AF_INET6: {
2213                 const struct ipv6_pinfo *np = inet6_sk(ssk);
2214
2215                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
2216                         goto nla_put_failure;
2217                 break;
2218         }
2219 #endif
2220         default:
2221                 WARN_ON_ONCE(1);
2222                 goto nla_put_failure;
2223         }
2224
2225         genlmsg_end(skb, nlh);
2226         mptcp_nl_mcast_send(net, skb, GFP_KERNEL);
2227         return;
2228
2229 nla_put_failure:
2230         nlmsg_free(skb);
2231 }
2232
2233 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2234                  const struct sock *ssk, gfp_t gfp)
2235 {
2236         struct net *net = sock_net((const struct sock *)msk);
2237         struct nlmsghdr *nlh;
2238         struct sk_buff *skb;
2239
2240         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2241                 return;
2242
2243         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2244         if (!skb)
2245                 return;
2246
2247         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2248         if (!nlh)
2249                 goto nla_put_failure;
2250
2251         switch (type) {
2252         case MPTCP_EVENT_UNSPEC:
2253                 WARN_ON_ONCE(1);
2254                 break;
2255         case MPTCP_EVENT_CREATED:
2256         case MPTCP_EVENT_ESTABLISHED:
2257                 if (mptcp_event_created(skb, msk, ssk) < 0)
2258                         goto nla_put_failure;
2259                 break;
2260         case MPTCP_EVENT_CLOSED:
2261                 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, READ_ONCE(msk->token)) < 0)
2262                         goto nla_put_failure;
2263                 break;
2264         case MPTCP_EVENT_ANNOUNCED:
2265         case MPTCP_EVENT_REMOVED:
2266                 /* call mptcp_event_addr_announced()/removed instead */
2267                 WARN_ON_ONCE(1);
2268                 break;
2269         case MPTCP_EVENT_SUB_ESTABLISHED:
2270         case MPTCP_EVENT_SUB_PRIORITY:
2271                 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2272                         goto nla_put_failure;
2273                 break;
2274         case MPTCP_EVENT_SUB_CLOSED:
2275                 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2276                         goto nla_put_failure;
2277                 break;
2278         case MPTCP_EVENT_LISTENER_CREATED:
2279         case MPTCP_EVENT_LISTENER_CLOSED:
2280                 break;
2281         }
2282
2283         genlmsg_end(skb, nlh);
2284         mptcp_nl_mcast_send(net, skb, gfp);
2285         return;
2286
2287 nla_put_failure:
2288         nlmsg_free(skb);
2289 }
2290
2291 struct genl_family mptcp_genl_family __ro_after_init = {
2292         .name           = MPTCP_PM_NAME,
2293         .version        = MPTCP_PM_VER,
2294         .netnsok        = true,
2295         .module         = THIS_MODULE,
2296         .ops            = mptcp_pm_nl_ops,
2297         .n_ops          = ARRAY_SIZE(mptcp_pm_nl_ops),
2298         .resv_start_op  = MPTCP_PM_CMD_SUBFLOW_DESTROY + 1,
2299         .mcgrps         = mptcp_pm_mcgrps,
2300         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
2301 };
2302
2303 static int __net_init pm_nl_init_net(struct net *net)
2304 {
2305         struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2306
2307         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2308
2309         /* Cit. 2 subflows ought to be enough for anybody. */
2310         pernet->subflows_max = 2;
2311         pernet->next_id = 1;
2312         pernet->stale_loss_cnt = 4;
2313         spin_lock_init(&pernet->lock);
2314
2315         /* No need to initialize other pernet fields, the struct is zeroed at
2316          * allocation time.
2317          */
2318
2319         return 0;
2320 }
2321
2322 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2323 {
2324         struct net *net;
2325
2326         list_for_each_entry(net, net_list, exit_list) {
2327                 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2328
2329                 /* net is removed from namespace list, can't race with
2330                  * other modifiers, also netns core already waited for a
2331                  * RCU grace period.
2332                  */
2333                 __flush_addrs(&pernet->local_addr_list);
2334         }
2335 }
2336
2337 static struct pernet_operations mptcp_pm_pernet_ops = {
2338         .init = pm_nl_init_net,
2339         .exit_batch = pm_nl_exit_net,
2340         .id = &pm_nl_pernet_id,
2341         .size = sizeof(struct pm_nl_pernet),
2342 };
2343
2344 void __init mptcp_pm_nl_init(void)
2345 {
2346         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2347                 panic("Failed to register MPTCP PM pernet subsystem.\n");
2348
2349         if (genl_register_family(&mptcp_genl_family))
2350                 panic("Failed to register MPTCP PM netlink family\n");
2351 }