net/mptcp/pm_netlink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2020, Red Hat, Inc.
   5  */
   6
   7 #define pr_fmt(fmt) "MPTCP: " fmt
   8
   9 #include <linux/inet.h>
  10 #include <linux/kernel.h>
  11 #include <net/tcp.h>
  12 #include <net/netns/generic.h>
  13 #include <net/mptcp.h>
  14 #include <net/genetlink.h>
  15 #include <uapi/linux/mptcp.h>
  16
  17 #include "protocol.h"
  18 #include "mib.h"
  19
  20 /* forward declaration */
  21 static struct genl_family mptcp_genl_family;
  22
  23 static int pm_nl_pernet_id;
  24
  25 struct mptcp_pm_add_entry {
  26         struct list_head        list;
  27         struct mptcp_addr_info  addr;
  28         struct timer_list       add_timer;
  29         struct mptcp_sock       *sock;
  30         u8                      retrans_times;
  31 };
  32
  33 struct pm_nl_pernet {
  34         /* protects pernet updates */
  35         spinlock_t              lock;
  36         struct list_head        local_addr_list;
  37         unsigned int            addrs;
  38         unsigned int            stale_loss_cnt;
  39         unsigned int            add_addr_signal_max;
  40         unsigned int            add_addr_accept_max;
  41         unsigned int            local_addr_max;
  42         unsigned int            subflows_max;
  43         unsigned int            next_id;
  44         DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  45 };
  46
  47 #define MPTCP_PM_ADDR_MAX       8
  48 #define ADD_ADDR_RETRANS_MAX    3
  49
  50 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net)
  51 {
  52         return net_generic(net, pm_nl_pernet_id);
  53 }
  54
  55 static struct pm_nl_pernet *
  56 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk)
  57 {
  58         return pm_nl_get_pernet(sock_net((struct sock *)msk));
  59 }
  60
  61 bool mptcp_addresses_equal(const struct mptcp_addr_info *a,
  62                            const struct mptcp_addr_info *b, bool use_port)
  63 {
  64         bool addr_equals = false;
  65
  66         if (a->family == b->family) {
  67                 if (a->family == AF_INET)
  68                         addr_equals = a->addr.s_addr == b->addr.s_addr;
  69 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  70                 else
  71                         addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
  72         } else if (a->family == AF_INET) {
  73                 if (ipv6_addr_v4mapped(&b->addr6))
  74                         addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
  75         } else if (b->family == AF_INET) {
  76                 if (ipv6_addr_v4mapped(&a->addr6))
  77                         addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
  78 #endif
  79         }
  80
  81         if (!addr_equals)
  82                 return false;
  83         if (!use_port)
  84                 return true;
  85
  86         return a->port == b->port;
  87 }
  88
  89 static void local_address(const struct sock_common *skc,
  90                           struct mptcp_addr_info *addr)
  91 {
  92         addr->family = skc->skc_family;
  93         addr->port = htons(skc->skc_num);
  94         if (addr->family == AF_INET)
  95                 addr->addr.s_addr = skc->skc_rcv_saddr;
  96 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  97         else if (addr->family == AF_INET6)
  98                 addr->addr6 = skc->skc_v6_rcv_saddr;
  99 #endif
 100 }
 101
 102 static void remote_address(const struct sock_common *skc,
 103                            struct mptcp_addr_info *addr)
 104 {
 105         addr->family = skc->skc_family;
 106         addr->port = skc->skc_dport;
 107         if (addr->family == AF_INET)
 108                 addr->addr.s_addr = skc->skc_daddr;
 109 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 110         else if (addr->family == AF_INET6)
 111                 addr->addr6 = skc->skc_v6_daddr;
 112 #endif
 113 }
 114
 115 static bool lookup_subflow_by_saddr(const struct list_head *list,
 116                                     const struct mptcp_addr_info *saddr)
 117 {
 118         struct mptcp_subflow_context *subflow;
 119         struct mptcp_addr_info cur;
 120         struct sock_common *skc;
 121
 122         list_for_each_entry(subflow, list, node) {
 123                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 124
 125                 local_address(skc, &cur);
 126                 if (mptcp_addresses_equal(&cur, saddr, saddr->port))
 127                         return true;
 128         }
 129
 130         return false;
 131 }
 132
 133 static bool lookup_subflow_by_daddr(const struct list_head *list,
 134                                     const struct mptcp_addr_info *daddr)
 135 {
 136         struct mptcp_subflow_context *subflow;
 137         struct mptcp_addr_info cur;
 138         struct sock_common *skc;
 139
 140         list_for_each_entry(subflow, list, node) {
 141                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 142
 143                 remote_address(skc, &cur);
 144                 if (mptcp_addresses_equal(&cur, daddr, daddr->port))
 145                         return true;
 146         }
 147
 148         return false;
 149 }
 150
 151 static struct mptcp_pm_addr_entry *
 152 select_local_address(const struct pm_nl_pernet *pernet,
 153                      const struct mptcp_sock *msk)
 154 {
 155         const struct sock *sk = (const struct sock *)msk;
 156         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 157
 158         msk_owned_by_me(msk);
 159
 160         rcu_read_lock();
 161         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 162                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 163                         continue;
 164
 165                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 166                         continue;
 167
 168                 if (entry->addr.family != sk->sk_family) {
 169 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 170                         if ((entry->addr.family == AF_INET &&
 171                              !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
 172                             (sk->sk_family == AF_INET &&
 173                              !ipv6_addr_v4mapped(&entry->addr.addr6)))
 174 #endif
 175                                 continue;
 176                 }
 177
 178                 ret = entry;
 179                 break;
 180         }
 181         rcu_read_unlock();
 182         return ret;
 183 }
 184
 185 static struct mptcp_pm_addr_entry *
 186 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk)
 187 {
 188         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 189
 190         rcu_read_lock();
 191         /* do not keep any additional per socket state, just signal
 192          * the address list in order.
 193          * Note: removal from the local address list during the msk life-cycle
 194          * can lead to additional addresses not being announced.
 195          */
 196         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 197                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 198                         continue;
 199
 200                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
 201                         continue;
 202
 203                 ret = entry;
 204                 break;
 205         }
 206         rcu_read_unlock();
 207         return ret;
 208 }
 209
 210 unsigned int mptcp_pm_get_add_addr_signal_max(const struct mptcp_sock *msk)
 211 {
 212         const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 213
 214         return READ_ONCE(pernet->add_addr_signal_max);
 215 }
 216 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
 217
 218 unsigned int mptcp_pm_get_add_addr_accept_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->add_addr_accept_max);
 223 }
 224 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
 225
 226 unsigned int mptcp_pm_get_subflows_max(const struct mptcp_sock *msk)
 227 {
 228         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 229
 230         return READ_ONCE(pernet->subflows_max);
 231 }
 232 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
 233
 234 unsigned int mptcp_pm_get_local_addr_max(const struct mptcp_sock *msk)
 235 {
 236         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 237
 238         return READ_ONCE(pernet->local_addr_max);
 239 }
 240 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
 241
 242 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 243 {
 244         struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk);
 245
 246         if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
 247             (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
 248                                MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
 249                 WRITE_ONCE(msk->pm.work_pending, false);
 250                 return false;
 251         }
 252         return true;
 253 }
 254
 255 struct mptcp_pm_add_entry *
 256 mptcp_lookup_anno_list_by_saddr(const struct mptcp_sock *msk,
 257                                 const struct mptcp_addr_info *addr)
 258 {
 259         struct mptcp_pm_add_entry *entry;
 260
 261         lockdep_assert_held(&msk->pm.lock);
 262
 263         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 264                 if (mptcp_addresses_equal(&entry->addr, addr, true))
 265                         return entry;
 266         }
 267
 268         return NULL;
 269 }
 270
 271 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 272 {
 273         struct mptcp_pm_add_entry *entry;
 274         struct mptcp_addr_info saddr;
 275         bool ret = false;
 276
 277         local_address((struct sock_common *)sk, &saddr);
 278
 279         spin_lock_bh(&msk->pm.lock);
 280         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 281                 if (mptcp_addresses_equal(&entry->addr, &saddr, true)) {
 282                         ret = true;
 283                         goto out;
 284                 }
 285         }
 286
 287 out:
 288         spin_unlock_bh(&msk->pm.lock);
 289         return ret;
 290 }
 291
 292 static void mptcp_pm_add_timer(struct timer_list *timer)
 293 {
 294         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 295         struct mptcp_sock *msk = entry->sock;
 296         struct sock *sk = (struct sock *)msk;
 297
 298         pr_debug("msk=%p", msk);
 299
 300         if (!msk)
 301                 return;
 302
 303         if (inet_sk_state_load(sk) == TCP_CLOSE)
 304                 return;
 305
 306         if (!entry->addr.id)
 307                 return;
 308
 309         if (mptcp_pm_should_add_signal_addr(msk)) {
 310                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 311                 goto out;
 312         }
 313
 314         spin_lock_bh(&msk->pm.lock);
 315
 316         if (!mptcp_pm_should_add_signal_addr(msk)) {
 317                 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
 318                 mptcp_pm_announce_addr(msk, &entry->addr, false);
 319                 mptcp_pm_add_addr_send_ack(msk);
 320                 entry->retrans_times++;
 321         }
 322
 323         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 324                 sk_reset_timer(sk, timer,
 325                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
 326
 327         spin_unlock_bh(&msk->pm.lock);
 328
 329         if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
 330                 mptcp_pm_subflow_established(msk);
 331
 332 out:
 333         __sock_put(sk);
 334 }
 335
 336 struct mptcp_pm_add_entry *
 337 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 338                        const struct mptcp_addr_info *addr, bool check_id)
 339 {
 340         struct mptcp_pm_add_entry *entry;
 341         struct sock *sk = (struct sock *)msk;
 342
 343         spin_lock_bh(&msk->pm.lock);
 344         entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 345         if (entry && (!check_id || entry->addr.id == addr->id))
 346                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 347         spin_unlock_bh(&msk->pm.lock);
 348
 349         if (entry && (!check_id || entry->addr.id == addr->id))
 350                 sk_stop_timer_sync(sk, &entry->add_timer);
 351
 352         return entry;
 353 }
 354
 355 bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 356                               const struct mptcp_pm_addr_entry *entry)
 357 {
 358         struct mptcp_pm_add_entry *add_entry = NULL;
 359         struct sock *sk = (struct sock *)msk;
 360         struct net *net = sock_net(sk);
 361
 362         lockdep_assert_held(&msk->pm.lock);
 363
 364         add_entry = mptcp_lookup_anno_list_by_saddr(msk, &entry->addr);
 365
 366         if (add_entry) {
 367                 if (mptcp_pm_is_kernel(msk))
 368                         return false;
 369
 370                 sk_reset_timer(sk, &add_entry->add_timer,
 371                                jiffies + mptcp_get_add_addr_timeout(net));
 372                 return true;
 373         }
 374
 375         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
 376         if (!add_entry)
 377                 return false;
 378
 379         list_add(&add_entry->list, &msk->pm.anno_list);
 380
 381         add_entry->addr = entry->addr;
 382         add_entry->sock = msk;
 383         add_entry->retrans_times = 0;
 384
 385         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 386         sk_reset_timer(sk, &add_entry->add_timer,
 387                        jiffies + mptcp_get_add_addr_timeout(net));
 388
 389         return true;
 390 }
 391
 392 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 393 {
 394         struct mptcp_pm_add_entry *entry, *tmp;
 395         struct sock *sk = (struct sock *)msk;
 396         LIST_HEAD(free_list);
 397
 398         pr_debug("msk=%p", msk);
 399
 400         spin_lock_bh(&msk->pm.lock);
 401         list_splice_init(&msk->pm.anno_list, &free_list);
 402         spin_unlock_bh(&msk->pm.lock);
 403
 404         list_for_each_entry_safe(entry, tmp, &free_list, list) {
 405                 sk_stop_timer_sync(sk, &entry->add_timer);
 406                 kfree(entry);
 407         }
 408 }
 409
 410 static bool lookup_address_in_vec(const struct mptcp_addr_info *addrs, unsigned int nr,
 411                                   const struct mptcp_addr_info *addr)
 412 {
 413         int i;
 414
 415         for (i = 0; i < nr; i++) {
 416                 if (mptcp_addresses_equal(&addrs[i], addr, addr->port))
 417                         return true;
 418         }
 419
 420         return false;
 421 }
 422
 423 /* Fill all the remote addresses into the array addrs[],
 424  * and return the array size.
 425  */
 426 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk, bool fullmesh,
 427                                               struct mptcp_addr_info *addrs)
 428 {
 429         bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
 430         struct sock *sk = (struct sock *)msk, *ssk;
 431         struct mptcp_subflow_context *subflow;
 432         struct mptcp_addr_info remote = { 0 };
 433         unsigned int subflows_max;
 434         int i = 0;
 435
 436         subflows_max = mptcp_pm_get_subflows_max(msk);
 437         remote_address((struct sock_common *)sk, &remote);
 438
 439         /* Non-fullmesh endpoint, fill in the single entry
 440          * corresponding to the primary MPC subflow remote address
 441          */
 442         if (!fullmesh) {
 443                 if (deny_id0)
 444                         return 0;
 445
 446                 msk->pm.subflows++;
 447                 addrs[i++] = remote;
 448         } else {
 449                 mptcp_for_each_subflow(msk, subflow) {
 450                         ssk = mptcp_subflow_tcp_sock(subflow);
 451                         remote_address((struct sock_common *)ssk, &addrs[i]);
 452                         if (deny_id0 && mptcp_addresses_equal(&addrs[i], &remote, false))
 453                                 continue;
 454
 455                         if (!lookup_address_in_vec(addrs, i, &addrs[i]) &&
 456                             msk->pm.subflows < subflows_max) {
 457                                 msk->pm.subflows++;
 458                                 i++;
 459                         }
 460                 }
 461         }
 462
 463         return i;
 464 }
 465
 466 static struct mptcp_pm_addr_entry *
 467 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 468 {
 469         struct mptcp_pm_addr_entry *entry;
 470
 471         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 472                 if (entry->addr.id == id)
 473                         return entry;
 474         }
 475         return NULL;
 476 }
 477
 478 static struct mptcp_pm_addr_entry *
 479 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
 480               bool lookup_by_id)
 481 {
 482         struct mptcp_pm_addr_entry *entry;
 483
 484         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 485                 if ((!lookup_by_id && mptcp_addresses_equal(&entry->addr, info, true)) ||
 486                     (lookup_by_id && entry->addr.id == info->id))
 487                         return entry;
 488         }
 489         return NULL;
 490 }
 491
 492 static int
 493 lookup_id_by_addr(const struct pm_nl_pernet *pernet, const struct mptcp_addr_info *addr)
 494 {
 495         const struct mptcp_pm_addr_entry *entry;
 496         int ret = -1;
 497
 498         rcu_read_lock();
 499         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 500                 if (mptcp_addresses_equal(&entry->addr, addr, entry->addr.port)) {
 501                         ret = entry->addr.id;
 502                         break;
 503                 }
 504         }
 505         rcu_read_unlock();
 506         return ret;
 507 }
 508
 509 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 510 {
 511         struct sock *sk = (struct sock *)msk;
 512         struct mptcp_pm_addr_entry *local;
 513         unsigned int add_addr_signal_max;
 514         unsigned int local_addr_max;
 515         struct pm_nl_pernet *pernet;
 516         unsigned int subflows_max;
 517
 518         pernet = pm_nl_get_pernet(sock_net(sk));
 519
 520         add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
 521         local_addr_max = mptcp_pm_get_local_addr_max(msk);
 522         subflows_max = mptcp_pm_get_subflows_max(msk);
 523
 524         /* do lazy endpoint usage accounting for the MPC subflows */
 525         if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
 526                 struct mptcp_addr_info mpc_addr;
 527                 int mpc_id;
 528
 529                 local_address((struct sock_common *)msk->first, &mpc_addr);
 530                 mpc_id = lookup_id_by_addr(pernet, &mpc_addr);
 531                 if (mpc_id >= 0)
 532                         __clear_bit(mpc_id, msk->pm.id_avail_bitmap);
 533
 534                 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
 535         }
 536
 537         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
 538                  msk->pm.local_addr_used, local_addr_max,
 539                  msk->pm.add_addr_signaled, add_addr_signal_max,
 540                  msk->pm.subflows, subflows_max);
 541
 542         /* check first for announce */
 543         if (msk->pm.add_addr_signaled < add_addr_signal_max) {
 544                 local = select_signal_address(pernet, msk);
 545
 546                 /* due to racing events on both ends we can reach here while
 547                  * previous add address is still running: if we invoke now
 548                  * mptcp_pm_announce_addr(), that will fail and the
 549                  * corresponding id will be marked as used.
 550                  * Instead let the PM machinery reschedule us when the
 551                  * current address announce will be completed.
 552                  */
 553                 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
 554                         return;
 555
 556                 if (local) {
 557                         if (mptcp_pm_alloc_anno_list(msk, local)) {
 558                                 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 559                                 msk->pm.add_addr_signaled++;
 560                                 mptcp_pm_announce_addr(msk, &local->addr, false);
 561                                 mptcp_pm_nl_addr_send_ack(msk);
 562                         }
 563                 }
 564         }
 565
 566         /* check if should create a new subflow */
 567         while (msk->pm.local_addr_used < local_addr_max &&
 568                msk->pm.subflows < subflows_max) {
 569                 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 570                 bool fullmesh;
 571                 int i, nr;
 572
 573                 local = select_local_address(pernet, msk);
 574                 if (!local)
 575                         break;
 576
 577                 fullmesh = !!(local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
 578
 579                 msk->pm.local_addr_used++;
 580                 nr = fill_remote_addresses_vec(msk, fullmesh, addrs);
 581                 if (nr)
 582                         __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 583                 spin_unlock_bh(&msk->pm.lock);
 584                 for (i = 0; i < nr; i++)
 585                         __mptcp_subflow_connect(sk, &local->addr, &addrs[i]);
 586                 spin_lock_bh(&msk->pm.lock);
 587         }
 588         mptcp_pm_nl_check_work_pending(msk);
 589 }
 590
 591 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 592 {
 593         mptcp_pm_create_subflow_or_signal_addr(msk);
 594 }
 595
 596 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 597 {
 598         mptcp_pm_create_subflow_or_signal_addr(msk);
 599 }
 600
 601 /* Fill all the local addresses into the array addrs[],
 602  * and return the array size.
 603  */
 604 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
 605                                              struct mptcp_addr_info *addrs)
 606 {
 607         struct sock *sk = (struct sock *)msk;
 608         struct mptcp_pm_addr_entry *entry;
 609         struct mptcp_addr_info local;
 610         struct pm_nl_pernet *pernet;
 611         unsigned int subflows_max;
 612         int i = 0;
 613
 614         pernet = pm_nl_get_pernet_from_msk(msk);
 615         subflows_max = mptcp_pm_get_subflows_max(msk);
 616
 617         rcu_read_lock();
 618         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 619                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
 620                         continue;
 621
 622                 if (entry->addr.family != sk->sk_family) {
 623 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 624                         if ((entry->addr.family == AF_INET &&
 625                              !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
 626                             (sk->sk_family == AF_INET &&
 627                              !ipv6_addr_v4mapped(&entry->addr.addr6)))
 628 #endif
 629                                 continue;
 630                 }
 631
 632                 if (msk->pm.subflows < subflows_max) {
 633                         msk->pm.subflows++;
 634                         addrs[i++] = entry->addr;
 635                 }
 636         }
 637         rcu_read_unlock();
 638
 639         /* If the array is empty, fill in the single
 640          * 'IPADDRANY' local address
 641          */
 642         if (!i) {
 643                 memset(&local, 0, sizeof(local));
 644                 local.family = msk->pm.remote.family;
 645
 646                 msk->pm.subflows++;
 647                 addrs[i++] = local;
 648         }
 649
 650         return i;
 651 }
 652
 653 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 654 {
 655         struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 656         struct sock *sk = (struct sock *)msk;
 657         unsigned int add_addr_accept_max;
 658         struct mptcp_addr_info remote;
 659         unsigned int subflows_max;
 660         int i, nr;
 661
 662         add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
 663         subflows_max = mptcp_pm_get_subflows_max(msk);
 664
 665         pr_debug("accepted %d:%d remote family %d",
 666                  msk->pm.add_addr_accepted, add_addr_accept_max,
 667                  msk->pm.remote.family);
 668
 669         remote = msk->pm.remote;
 670         mptcp_pm_announce_addr(msk, &remote, true);
 671         mptcp_pm_nl_addr_send_ack(msk);
 672
 673         if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
 674                 return;
 675
 676         /* pick id 0 port, if none is provided the remote address */
 677         if (!remote.port)
 678                 remote.port = sk->sk_dport;
 679
 680         /* connect to the specified remote address, using whatever
 681          * local address the routing configuration will pick.
 682          */
 683         nr = fill_local_addresses_vec(msk, addrs);
 684
 685         msk->pm.add_addr_accepted++;
 686         if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
 687             msk->pm.subflows >= subflows_max)
 688                 WRITE_ONCE(msk->pm.accept_addr, false);
 689
 690         spin_unlock_bh(&msk->pm.lock);
 691         for (i = 0; i < nr; i++)
 692                 __mptcp_subflow_connect(sk, &addrs[i], &remote);
 693         spin_lock_bh(&msk->pm.lock);
 694 }
 695
 696 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
 697 {
 698         struct mptcp_subflow_context *subflow;
 699
 700         msk_owned_by_me(msk);
 701         lockdep_assert_held(&msk->pm.lock);
 702
 703         if (!mptcp_pm_should_add_signal(msk) &&
 704             !mptcp_pm_should_rm_signal(msk))
 705                 return;
 706
 707         subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
 708         if (subflow) {
 709                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 710
 711                 spin_unlock_bh(&msk->pm.lock);
 712                 pr_debug("send ack for %s",
 713                          mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr");
 714
 715                 mptcp_subflow_send_ack(ssk);
 716                 spin_lock_bh(&msk->pm.lock);
 717         }
 718 }
 719
 720 static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 721                                         struct mptcp_addr_info *addr,
 722                                         u8 bkup)
 723 {
 724         struct mptcp_subflow_context *subflow;
 725
 726         pr_debug("bkup=%d", bkup);
 727
 728         mptcp_for_each_subflow(msk, subflow) {
 729                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 730                 struct sock *sk = (struct sock *)msk;
 731                 struct mptcp_addr_info local;
 732
 733                 local_address((struct sock_common *)ssk, &local);
 734                 if (!mptcp_addresses_equal(&local, addr, addr->port))
 735                         continue;
 736
 737                 if (subflow->backup != bkup)
 738                         msk->last_snd = NULL;
 739                 subflow->backup = bkup;
 740                 subflow->send_mp_prio = 1;
 741                 subflow->request_bkup = bkup;
 742                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIOTX);
 743
 744                 spin_unlock_bh(&msk->pm.lock);
 745                 pr_debug("send ack for mp_prio");
 746                 mptcp_subflow_send_ack(ssk);
 747                 spin_lock_bh(&msk->pm.lock);
 748
 749                 return 0;
 750         }
 751
 752         return -EINVAL;
 753 }
 754
 755 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 756                                            const struct mptcp_rm_list *rm_list,
 757                                            enum linux_mptcp_mib_field rm_type)
 758 {
 759         struct mptcp_subflow_context *subflow, *tmp;
 760         struct sock *sk = (struct sock *)msk;
 761         u8 i;
 762
 763         pr_debug("%s rm_list_nr %d",
 764                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
 765
 766         msk_owned_by_me(msk);
 767
 768         if (sk->sk_state == TCP_LISTEN)
 769                 return;
 770
 771         if (!rm_list->nr)
 772                 return;
 773
 774         if (list_empty(&msk->conn_list))
 775                 return;
 776
 777         for (i = 0; i < rm_list->nr; i++) {
 778                 bool removed = false;
 779
 780                 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
 781                         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 782                         int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 783                         u8 id = subflow->local_id;
 784
 785                         if (rm_type == MPTCP_MIB_RMADDR)
 786                                 id = subflow->remote_id;
 787
 788                         if (rm_list->ids[i] != id)
 789                                 continue;
 790
 791                         pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u",
 792                                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
 793                                  i, rm_list->ids[i], subflow->local_id, subflow->remote_id);
 794                         spin_unlock_bh(&msk->pm.lock);
 795                         mptcp_subflow_shutdown(sk, ssk, how);
 796
 797                         /* the following takes care of updating the subflows counter */
 798                         mptcp_close_ssk(sk, ssk, subflow);
 799                         spin_lock_bh(&msk->pm.lock);
 800
 801                         removed = true;
 802                         __MPTCP_INC_STATS(sock_net(sk), rm_type);
 803                 }
 804                 __set_bit(rm_list->ids[i], msk->pm.id_avail_bitmap);
 805                 if (!removed)
 806                         continue;
 807
 808                 if (!mptcp_pm_is_kernel(msk))
 809                         continue;
 810
 811                 if (rm_type == MPTCP_MIB_RMADDR) {
 812                         msk->pm.add_addr_accepted--;
 813                         WRITE_ONCE(msk->pm.accept_addr, true);
 814                 } else if (rm_type == MPTCP_MIB_RMSUBFLOW) {
 815                         msk->pm.local_addr_used--;
 816                 }
 817         }
 818 }
 819
 820 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
 821 {
 822         mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
 823 }
 824
 825 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 826                                      const struct mptcp_rm_list *rm_list)
 827 {
 828         mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
 829 }
 830
 831 void mptcp_pm_nl_work(struct mptcp_sock *msk)
 832 {
 833         struct mptcp_pm_data *pm = &msk->pm;
 834
 835         msk_owned_by_me(msk);
 836
 837         if (!(pm->status & MPTCP_PM_WORK_MASK))
 838                 return;
 839
 840         spin_lock_bh(&msk->pm.lock);
 841
 842         pr_debug("msk=%p status=%x", msk, pm->status);
 843         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
 844                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 845                 mptcp_pm_nl_add_addr_received(msk);
 846         }
 847         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 848                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
 849                 mptcp_pm_nl_addr_send_ack(msk);
 850         }
 851         if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
 852                 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
 853                 mptcp_pm_nl_rm_addr_received(msk);
 854         }
 855         if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
 856                 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 857                 mptcp_pm_nl_fully_established(msk);
 858         }
 859         if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
 860                 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
 861                 mptcp_pm_nl_subflow_established(msk);
 862         }
 863
 864         spin_unlock_bh(&msk->pm.lock);
 865 }
 866
 867 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
 868 {
 869         return (entry->flags &
 870                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
 871                 MPTCP_PM_ADDR_FLAG_SIGNAL;
 872 }
 873
 874 /* caller must ensure the RCU grace period is already elapsed */
 875 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
 876 {
 877         if (entry->lsk)
 878                 sock_release(entry->lsk);
 879         kfree(entry);
 880 }
 881
 882 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 883                                              struct mptcp_pm_addr_entry *entry)
 884 {
 885         struct mptcp_pm_addr_entry *cur, *del_entry = NULL;
 886         unsigned int addr_max;
 887         int ret = -EINVAL;
 888
 889         spin_lock_bh(&pernet->lock);
 890         /* to keep the code simple, don't do IDR-like allocation for address ID,
 891          * just bail when we exceed limits
 892          */
 893         if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
 894                 pernet->next_id = 1;
 895         if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
 896                 goto out;
 897         if (test_bit(entry->addr.id, pernet->id_bitmap))
 898                 goto out;
 899
 900         /* do not insert duplicate address, differentiate on port only
 901          * singled addresses
 902          */
 903         list_for_each_entry(cur, &pernet->local_addr_list, list) {
 904                 if (mptcp_addresses_equal(&cur->addr, &entry->addr,
 905                                           address_use_port(entry) &&
 906                                           address_use_port(cur))) {
 907                         /* allow replacing the exiting endpoint only if such
 908                          * endpoint is an implicit one and the user-space
 909                          * did not provide an endpoint id
 910                          */
 911                         if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT))
 912                                 goto out;
 913                         if (entry->addr.id)
 914                                 goto out;
 915
 916                         pernet->addrs--;
 917                         entry->addr.id = cur->addr.id;
 918                         list_del_rcu(&cur->list);
 919                         del_entry = cur;
 920                         break;
 921                 }
 922         }
 923
 924         if (!entry->addr.id) {
 925 find_next:
 926                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
 927                                                     MPTCP_PM_MAX_ADDR_ID + 1,
 928                                                     pernet->next_id);
 929                 if (!entry->addr.id && pernet->next_id != 1) {
 930                         pernet->next_id = 1;
 931                         goto find_next;
 932                 }
 933         }
 934
 935         if (!entry->addr.id)
 936                 goto out;
 937
 938         __set_bit(entry->addr.id, pernet->id_bitmap);
 939         if (entry->addr.id > pernet->next_id)
 940                 pernet->next_id = entry->addr.id;
 941
 942         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
 943                 addr_max = pernet->add_addr_signal_max;
 944                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
 945         }
 946         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
 947                 addr_max = pernet->local_addr_max;
 948                 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
 949         }
 950
 951         pernet->addrs++;
 952         list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
 953         ret = entry->addr.id;
 954
 955 out:
 956         spin_unlock_bh(&pernet->lock);
 957
 958         /* just replaced an existing entry, free it */
 959         if (del_entry) {
 960                 synchronize_rcu();
 961                 __mptcp_pm_release_addr_entry(del_entry);
 962         }
 963         return ret;
 964 }
 965
 966 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 967                                             struct mptcp_pm_addr_entry *entry)
 968 {
 969         int addrlen = sizeof(struct sockaddr_in);
 970         struct sockaddr_storage addr;
 971         struct mptcp_sock *msk;
 972         struct socket *ssock;
 973         int backlog = 1024;
 974         int err;
 975
 976         err = sock_create_kern(sock_net(sk), entry->addr.family,
 977                                SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
 978         if (err)
 979                 return err;
 980
 981         msk = mptcp_sk(entry->lsk->sk);
 982         if (!msk) {
 983                 err = -EINVAL;
 984                 goto out;
 985         }
 986
 987         ssock = __mptcp_nmpc_socket(msk);
 988         if (!ssock) {
 989                 err = -EINVAL;
 990                 goto out;
 991         }
 992
 993         mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
 994 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 995         if (entry->addr.family == AF_INET6)
 996                 addrlen = sizeof(struct sockaddr_in6);
 997 #endif
 998         err = kernel_bind(ssock, (struct sockaddr *)&addr, addrlen);
 999         if (err) {
1000                 pr_warn("kernel_bind error, err=%d", err);
1001                 goto out;
1002         }
1003
1004         err = kernel_listen(ssock, backlog);
1005         if (err) {
1006                 pr_warn("kernel_listen error, err=%d", err);
1007                 goto out;
1008         }
1009
1010         return 0;
1011
1012 out:
1013         sock_release(entry->lsk);
1014         return err;
1015 }
1016
1017 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
1018 {
1019         struct mptcp_pm_addr_entry *entry;
1020         struct mptcp_addr_info skc_local;
1021         struct mptcp_addr_info msk_local;
1022         struct pm_nl_pernet *pernet;
1023         int ret = -1;
1024
1025         if (WARN_ON_ONCE(!msk))
1026                 return -1;
1027
1028         /* The 0 ID mapping is defined by the first subflow, copied into the msk
1029          * addr
1030          */
1031         local_address((struct sock_common *)msk, &msk_local);
1032         local_address((struct sock_common *)skc, &skc_local);
1033         if (mptcp_addresses_equal(&msk_local, &skc_local, false))
1034                 return 0;
1035
1036         if (mptcp_pm_is_userspace(msk))
1037                 return mptcp_userspace_pm_get_local_id(msk, &skc_local);
1038
1039         pernet = pm_nl_get_pernet_from_msk(msk);
1040
1041         rcu_read_lock();
1042         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1043                 if (mptcp_addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
1044                         ret = entry->addr.id;
1045                         break;
1046                 }
1047         }
1048         rcu_read_unlock();
1049         if (ret >= 0)
1050                 return ret;
1051
1052         /* address not found, add to local list */
1053         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1054         if (!entry)
1055                 return -ENOMEM;
1056
1057         entry->addr = skc_local;
1058         entry->addr.id = 0;
1059         entry->addr.port = 0;
1060         entry->ifindex = 0;
1061         entry->flags = MPTCP_PM_ADDR_FLAG_IMPLICIT;
1062         entry->lsk = NULL;
1063         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1064         if (ret < 0)
1065                 kfree(entry);
1066
1067         return ret;
1068 }
1069
1070 #define MPTCP_PM_CMD_GRP_OFFSET       0
1071 #define MPTCP_PM_EV_GRP_OFFSET        1
1072
1073 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1074         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
1075         [MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
1076                                             .flags = GENL_UNS_ADMIN_PERM,
1077                                           },
1078 };
1079
1080 static const struct nla_policy
1081 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
1082         [MPTCP_PM_ADDR_ATTR_FAMILY]     = { .type       = NLA_U16,      },
1083         [MPTCP_PM_ADDR_ATTR_ID]         = { .type       = NLA_U8,       },
1084         [MPTCP_PM_ADDR_ATTR_ADDR4]      = { .type       = NLA_U32,      },
1085         [MPTCP_PM_ADDR_ATTR_ADDR6]      =
1086                 NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
1087         [MPTCP_PM_ADDR_ATTR_PORT]       = { .type       = NLA_U16       },
1088         [MPTCP_PM_ADDR_ATTR_FLAGS]      = { .type       = NLA_U32       },
1089         [MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type       = NLA_S32       },
1090 };
1091
1092 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
1093         [MPTCP_PM_ATTR_ADDR]            =
1094                                         NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1095         [MPTCP_PM_ATTR_RCV_ADD_ADDRS]   = { .type       = NLA_U32,      },
1096         [MPTCP_PM_ATTR_SUBFLOWS]        = { .type       = NLA_U32,      },
1097         [MPTCP_PM_ATTR_TOKEN]           = { .type       = NLA_U32,      },
1098         [MPTCP_PM_ATTR_LOC_ID]          = { .type       = NLA_U8,       },
1099         [MPTCP_PM_ATTR_ADDR_REMOTE]     =
1100                                         NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1101 };
1102
1103 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1104 {
1105         struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1106         struct sock *sk = (struct sock *)msk;
1107         unsigned int active_max_loss_cnt;
1108         struct net *net = sock_net(sk);
1109         unsigned int stale_loss_cnt;
1110         bool slow;
1111
1112         stale_loss_cnt = mptcp_stale_loss_cnt(net);
1113         if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1114                 return;
1115
1116         /* look for another available subflow not in loss state */
1117         active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1118         mptcp_for_each_subflow(msk, iter) {
1119                 if (iter != subflow && mptcp_subflow_active(iter) &&
1120                     iter->stale_count < active_max_loss_cnt) {
1121                         /* we have some alternatives, try to mark this subflow as idle ...*/
1122                         slow = lock_sock_fast(ssk);
1123                         if (!tcp_rtx_and_write_queues_empty(ssk)) {
1124                                 subflow->stale = 1;
1125                                 __mptcp_retransmit_pending_data(sk);
1126                                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_SUBFLOWSTALE);
1127                         }
1128                         unlock_sock_fast(ssk, slow);
1129
1130                         /* always try to push the pending data regarless of re-injections:
1131                          * we can possibly use backup subflows now, and subflow selection
1132                          * is cheap under the msk socket lock
1133                          */
1134                         __mptcp_push_pending(sk, 0);
1135                         return;
1136                 }
1137         }
1138 }
1139
1140 static int mptcp_pm_family_to_addr(int family)
1141 {
1142 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1143         if (family == AF_INET6)
1144                 return MPTCP_PM_ADDR_ATTR_ADDR6;
1145 #endif
1146         return MPTCP_PM_ADDR_ATTR_ADDR4;
1147 }
1148
1149 static int mptcp_pm_parse_pm_addr_attr(struct nlattr *tb[],
1150                                        const struct nlattr *attr,
1151                                        struct genl_info *info,
1152                                        struct mptcp_addr_info *addr,
1153                                        bool require_family)
1154 {
1155         int err, addr_addr;
1156
1157         if (!attr) {
1158                 GENL_SET_ERR_MSG(info, "missing address info");
1159                 return -EINVAL;
1160         }
1161
1162         /* no validation needed - was already done via nested policy */
1163         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1164                                           mptcp_pm_addr_policy, info->extack);
1165         if (err)
1166                 return err;
1167
1168         if (tb[MPTCP_PM_ADDR_ATTR_ID])
1169                 addr->id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1170
1171         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1172                 if (!require_family)
1173                         return err;
1174
1175                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1176                                     "missing family");
1177                 return -EINVAL;
1178         }
1179
1180         addr->family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1181         if (addr->family != AF_INET
1182 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1183             && addr->family != AF_INET6
1184 #endif
1185             ) {
1186                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1187                                     "unknown address family");
1188                 return -EINVAL;
1189         }
1190         addr_addr = mptcp_pm_family_to_addr(addr->family);
1191         if (!tb[addr_addr]) {
1192                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1193                                     "missing address data");
1194                 return -EINVAL;
1195         }
1196
1197 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1198         if (addr->family == AF_INET6)
1199                 addr->addr6 = nla_get_in6_addr(tb[addr_addr]);
1200         else
1201 #endif
1202                 addr->addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1203
1204         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1205                 addr->port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1206
1207         return err;
1208 }
1209
1210 int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1211                         struct mptcp_addr_info *addr)
1212 {
1213         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1214
1215         memset(addr, 0, sizeof(*addr));
1216
1217         return mptcp_pm_parse_pm_addr_attr(tb, attr, info, addr, true);
1218 }
1219
1220 int mptcp_pm_parse_entry(struct nlattr *attr, struct genl_info *info,
1221                          bool require_family,
1222                          struct mptcp_pm_addr_entry *entry)
1223 {
1224         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1225         int err;
1226
1227         memset(entry, 0, sizeof(*entry));
1228
1229         err = mptcp_pm_parse_pm_addr_attr(tb, attr, info, &entry->addr, require_family);
1230         if (err)
1231                 return err;
1232
1233         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1234                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1235
1236                 entry->ifindex = val;
1237         }
1238
1239         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1240                 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1241
1242         if (tb[MPTCP_PM_ADDR_ATTR_PORT])
1243                 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1244
1245         return 0;
1246 }
1247
1248 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1249 {
1250         return pm_nl_get_pernet(genl_info_net(info));
1251 }
1252
1253 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
1254 {
1255         struct mptcp_sock *msk;
1256         long s_slot = 0, s_num = 0;
1257
1258         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1259                 struct sock *sk = (struct sock *)msk;
1260
1261                 if (!READ_ONCE(msk->fully_established) ||
1262                     mptcp_pm_is_userspace(msk))
1263                         goto next;
1264
1265                 lock_sock(sk);
1266                 spin_lock_bh(&msk->pm.lock);
1267                 mptcp_pm_create_subflow_or_signal_addr(msk);
1268                 spin_unlock_bh(&msk->pm.lock);
1269                 release_sock(sk);
1270
1271 next:
1272                 sock_put(sk);
1273                 cond_resched();
1274         }
1275
1276         return 0;
1277 }
1278
1279 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1280 {
1281         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1282         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1283         struct mptcp_pm_addr_entry addr, *entry;
1284         int ret;
1285
1286         ret = mptcp_pm_parse_entry(attr, info, true, &addr);
1287         if (ret < 0)
1288                 return ret;
1289
1290         if (addr.addr.port && !(addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1291                 GENL_SET_ERR_MSG(info, "flags must have signal when using port");
1292                 return -EINVAL;
1293         }
1294
1295         if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL &&
1296             addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) {
1297                 GENL_SET_ERR_MSG(info, "flags mustn't have both signal and fullmesh");
1298                 return -EINVAL;
1299         }
1300
1301         if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) {
1302                 GENL_SET_ERR_MSG(info, "can't create IMPLICIT endpoint");
1303                 return -EINVAL;
1304         }
1305
1306         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1307         if (!entry) {
1308                 GENL_SET_ERR_MSG(info, "can't allocate addr");
1309                 return -ENOMEM;
1310         }
1311
1312         *entry = addr;
1313         if (entry->addr.port) {
1314                 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1315                 if (ret) {
1316                         GENL_SET_ERR_MSG(info, "create listen socket error");
1317                         kfree(entry);
1318                         return ret;
1319                 }
1320         }
1321         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1322         if (ret < 0) {
1323                 GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
1324                 if (entry->lsk)
1325                         sock_release(entry->lsk);
1326                 kfree(entry);
1327                 return ret;
1328         }
1329
1330         mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1331
1332         return 0;
1333 }
1334
1335 int mptcp_pm_get_flags_and_ifindex_by_id(struct mptcp_sock *msk, unsigned int id,
1336                                          u8 *flags, int *ifindex)
1337 {
1338         struct mptcp_pm_addr_entry *entry;
1339         struct sock *sk = (struct sock *)msk;
1340         struct net *net = sock_net(sk);
1341
1342         *flags = 0;
1343         *ifindex = 0;
1344
1345         if (id) {
1346                 if (mptcp_pm_is_userspace(msk))
1347                         return mptcp_userspace_pm_get_flags_and_ifindex_by_id(msk,
1348                                                                               id,
1349                                                                               flags,
1350                                                                               ifindex);
1351
1352                 rcu_read_lock();
1353                 entry = __lookup_addr_by_id(pm_nl_get_pernet(net), id);
1354                 if (entry) {
1355                         *flags = entry->flags;
1356                         *ifindex = entry->ifindex;
1357                 }
1358                 rcu_read_unlock();
1359         }
1360
1361         return 0;
1362 }
1363
1364 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1365                                       const struct mptcp_addr_info *addr)
1366 {
1367         struct mptcp_pm_add_entry *entry;
1368
1369         entry = mptcp_pm_del_add_timer(msk, addr, false);
1370         if (entry) {
1371                 list_del(&entry->list);
1372                 kfree(entry);
1373                 return true;
1374         }
1375
1376         return false;
1377 }
1378
1379 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1380                                       const struct mptcp_addr_info *addr,
1381                                       bool force)
1382 {
1383         struct mptcp_rm_list list = { .nr = 0 };
1384         bool ret;
1385
1386         list.ids[list.nr++] = addr->id;
1387
1388         ret = remove_anno_list_by_saddr(msk, addr);
1389         if (ret || force) {
1390                 spin_lock_bh(&msk->pm.lock);
1391                 mptcp_pm_remove_addr(msk, &list);
1392                 spin_unlock_bh(&msk->pm.lock);
1393         }
1394         return ret;
1395 }
1396
1397 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1398                                                    const struct mptcp_pm_addr_entry *entry)
1399 {
1400         const struct mptcp_addr_info *addr = &entry->addr;
1401         struct mptcp_rm_list list = { .nr = 0 };
1402         long s_slot = 0, s_num = 0;
1403         struct mptcp_sock *msk;
1404
1405         pr_debug("remove_id=%d", addr->id);
1406
1407         list.ids[list.nr++] = addr->id;
1408
1409         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1410                 struct sock *sk = (struct sock *)msk;
1411                 bool remove_subflow;
1412
1413                 if (mptcp_pm_is_userspace(msk))
1414                         goto next;
1415
1416                 if (list_empty(&msk->conn_list)) {
1417                         mptcp_pm_remove_anno_addr(msk, addr, false);
1418                         goto next;
1419                 }
1420
1421                 lock_sock(sk);
1422                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1423                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow &&
1424                                           !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT));
1425                 if (remove_subflow)
1426                         mptcp_pm_remove_subflow(msk, &list);
1427                 release_sock(sk);
1428
1429 next:
1430                 sock_put(sk);
1431                 cond_resched();
1432         }
1433
1434         return 0;
1435 }
1436
1437 static int mptcp_nl_remove_id_zero_address(struct net *net,
1438                                            struct mptcp_addr_info *addr)
1439 {
1440         struct mptcp_rm_list list = { .nr = 0 };
1441         long s_slot = 0, s_num = 0;
1442         struct mptcp_sock *msk;
1443
1444         list.ids[list.nr++] = 0;
1445
1446         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1447                 struct sock *sk = (struct sock *)msk;
1448                 struct mptcp_addr_info msk_local;
1449
1450                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1451                         goto next;
1452
1453                 local_address((struct sock_common *)msk, &msk_local);
1454                 if (!mptcp_addresses_equal(&msk_local, addr, addr->port))
1455                         goto next;
1456
1457                 lock_sock(sk);
1458                 spin_lock_bh(&msk->pm.lock);
1459                 mptcp_pm_remove_addr(msk, &list);
1460                 mptcp_pm_nl_rm_subflow_received(msk, &list);
1461                 spin_unlock_bh(&msk->pm.lock);
1462                 release_sock(sk);
1463
1464 next:
1465                 sock_put(sk);
1466                 cond_resched();
1467         }
1468
1469         return 0;
1470 }
1471
1472 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1473 {
1474         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1475         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1476         struct mptcp_pm_addr_entry addr, *entry;
1477         unsigned int addr_max;
1478         int ret;
1479
1480         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1481         if (ret < 0)
1482                 return ret;
1483
1484         /* the zero id address is special: the first address used by the msk
1485          * always gets such an id, so different subflows can have different zero
1486          * id addresses. Additionally zero id is not accounted for in id_bitmap.
1487          * Let's use an 'mptcp_rm_list' instead of the common remove code.
1488          */
1489         if (addr.addr.id == 0)
1490                 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1491
1492         spin_lock_bh(&pernet->lock);
1493         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1494         if (!entry) {
1495                 GENL_SET_ERR_MSG(info, "address not found");
1496                 spin_unlock_bh(&pernet->lock);
1497                 return -EINVAL;
1498         }
1499         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1500                 addr_max = pernet->add_addr_signal_max;
1501                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1502         }
1503         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1504                 addr_max = pernet->local_addr_max;
1505                 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1506         }
1507
1508         pernet->addrs--;
1509         list_del_rcu(&entry->list);
1510         __clear_bit(entry->addr.id, pernet->id_bitmap);
1511         spin_unlock_bh(&pernet->lock);
1512
1513         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry);
1514         synchronize_rcu();
1515         __mptcp_pm_release_addr_entry(entry);
1516
1517         return ret;
1518 }
1519
1520 void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1521                                         struct list_head *rm_list)
1522 {
1523         struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1524         struct mptcp_pm_addr_entry *entry;
1525
1526         list_for_each_entry(entry, rm_list, list) {
1527                 if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
1528                     slist.nr < MPTCP_RM_IDS_MAX)
1529                         slist.ids[slist.nr++] = entry->addr.id;
1530
1531                 if (remove_anno_list_by_saddr(msk, &entry->addr) &&
1532                     alist.nr < MPTCP_RM_IDS_MAX)
1533                         alist.ids[alist.nr++] = entry->addr.id;
1534         }
1535
1536         if (alist.nr) {
1537                 spin_lock_bh(&msk->pm.lock);
1538                 mptcp_pm_remove_addr(msk, &alist);
1539                 spin_unlock_bh(&msk->pm.lock);
1540         }
1541         if (slist.nr)
1542                 mptcp_pm_remove_subflow(msk, &slist);
1543 }
1544
1545 static void mptcp_nl_remove_addrs_list(struct net *net,
1546                                        struct list_head *rm_list)
1547 {
1548         long s_slot = 0, s_num = 0;
1549         struct mptcp_sock *msk;
1550
1551         if (list_empty(rm_list))
1552                 return;
1553
1554         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1555                 struct sock *sk = (struct sock *)msk;
1556
1557                 if (!mptcp_pm_is_userspace(msk)) {
1558                         lock_sock(sk);
1559                         mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1560                         release_sock(sk);
1561                 }
1562
1563                 sock_put(sk);
1564                 cond_resched();
1565         }
1566 }
1567
1568 /* caller must ensure the RCU grace period is already elapsed */
1569 static void __flush_addrs(struct list_head *list)
1570 {
1571         while (!list_empty(list)) {
1572                 struct mptcp_pm_addr_entry *cur;
1573
1574                 cur = list_entry(list->next,
1575                                  struct mptcp_pm_addr_entry, list);
1576                 list_del_rcu(&cur->list);
1577                 __mptcp_pm_release_addr_entry(cur);
1578         }
1579 }
1580
1581 static void __reset_counters(struct pm_nl_pernet *pernet)
1582 {
1583         WRITE_ONCE(pernet->add_addr_signal_max, 0);
1584         WRITE_ONCE(pernet->add_addr_accept_max, 0);
1585         WRITE_ONCE(pernet->local_addr_max, 0);
1586         pernet->addrs = 0;
1587 }
1588
1589 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1590 {
1591         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1592         LIST_HEAD(free_list);
1593
1594         spin_lock_bh(&pernet->lock);
1595         list_splice_init(&pernet->local_addr_list, &free_list);
1596         __reset_counters(pernet);
1597         pernet->next_id = 1;
1598         bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1599         spin_unlock_bh(&pernet->lock);
1600         mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1601         synchronize_rcu();
1602         __flush_addrs(&free_list);
1603         return 0;
1604 }
1605
1606 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1607                               struct mptcp_pm_addr_entry *entry)
1608 {
1609         struct mptcp_addr_info *addr = &entry->addr;
1610         struct nlattr *attr;
1611
1612         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1613         if (!attr)
1614                 return -EMSGSIZE;
1615
1616         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1617                 goto nla_put_failure;
1618         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1619                 goto nla_put_failure;
1620         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1621                 goto nla_put_failure;
1622         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1623                 goto nla_put_failure;
1624         if (entry->ifindex &&
1625             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1626                 goto nla_put_failure;
1627
1628         if (addr->family == AF_INET &&
1629             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1630                             addr->addr.s_addr))
1631                 goto nla_put_failure;
1632 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1633         else if (addr->family == AF_INET6 &&
1634                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1635                 goto nla_put_failure;
1636 #endif
1637         nla_nest_end(skb, attr);
1638         return 0;
1639
1640 nla_put_failure:
1641         nla_nest_cancel(skb, attr);
1642         return -EMSGSIZE;
1643 }
1644
1645 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1646 {
1647         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1648         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1649         struct mptcp_pm_addr_entry addr, *entry;
1650         struct sk_buff *msg;
1651         void *reply;
1652         int ret;
1653
1654         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1655         if (ret < 0)
1656                 return ret;
1657
1658         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1659         if (!msg)
1660                 return -ENOMEM;
1661
1662         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1663                                   info->genlhdr->cmd);
1664         if (!reply) {
1665                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1666                 ret = -EMSGSIZE;
1667                 goto fail;
1668         }
1669
1670         spin_lock_bh(&pernet->lock);
1671         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1672         if (!entry) {
1673                 GENL_SET_ERR_MSG(info, "address not found");
1674                 ret = -EINVAL;
1675                 goto unlock_fail;
1676         }
1677
1678         ret = mptcp_nl_fill_addr(msg, entry);
1679         if (ret)
1680                 goto unlock_fail;
1681
1682         genlmsg_end(msg, reply);
1683         ret = genlmsg_reply(msg, info);
1684         spin_unlock_bh(&pernet->lock);
1685         return ret;
1686
1687 unlock_fail:
1688         spin_unlock_bh(&pernet->lock);
1689
1690 fail:
1691         nlmsg_free(msg);
1692         return ret;
1693 }
1694
1695 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1696                                    struct netlink_callback *cb)
1697 {
1698         struct net *net = sock_net(msg->sk);
1699         struct mptcp_pm_addr_entry *entry;
1700         struct pm_nl_pernet *pernet;
1701         int id = cb->args[0];
1702         void *hdr;
1703         int i;
1704
1705         pernet = pm_nl_get_pernet(net);
1706
1707         spin_lock_bh(&pernet->lock);
1708         for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1709                 if (test_bit(i, pernet->id_bitmap)) {
1710                         entry = __lookup_addr_by_id(pernet, i);
1711                         if (!entry)
1712                                 break;
1713
1714                         if (entry->addr.id <= id)
1715                                 continue;
1716
1717                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1718                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1719                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1720                         if (!hdr)
1721                                 break;
1722
1723                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1724                                 genlmsg_cancel(msg, hdr);
1725                                 break;
1726                         }
1727
1728                         id = entry->addr.id;
1729                         genlmsg_end(msg, hdr);
1730                 }
1731         }
1732         spin_unlock_bh(&pernet->lock);
1733
1734         cb->args[0] = id;
1735         return msg->len;
1736 }
1737
1738 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1739 {
1740         struct nlattr *attr = info->attrs[id];
1741
1742         if (!attr)
1743                 return 0;
1744
1745         *limit = nla_get_u32(attr);
1746         if (*limit > MPTCP_PM_ADDR_MAX) {
1747                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1748                 return -EINVAL;
1749         }
1750         return 0;
1751 }
1752
1753 static int
1754 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1755 {
1756         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1757         unsigned int rcv_addrs, subflows;
1758         int ret;
1759
1760         spin_lock_bh(&pernet->lock);
1761         rcv_addrs = pernet->add_addr_accept_max;
1762         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1763         if (ret)
1764                 goto unlock;
1765
1766         subflows = pernet->subflows_max;
1767         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1768         if (ret)
1769                 goto unlock;
1770
1771         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1772         WRITE_ONCE(pernet->subflows_max, subflows);
1773
1774 unlock:
1775         spin_unlock_bh(&pernet->lock);
1776         return ret;
1777 }
1778
1779 static int
1780 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1781 {
1782         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1783         struct sk_buff *msg;
1784         void *reply;
1785
1786         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1787         if (!msg)
1788                 return -ENOMEM;
1789
1790         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1791                                   MPTCP_PM_CMD_GET_LIMITS);
1792         if (!reply)
1793                 goto fail;
1794
1795         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1796                         READ_ONCE(pernet->add_addr_accept_max)))
1797                 goto fail;
1798
1799         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1800                         READ_ONCE(pernet->subflows_max)))
1801                 goto fail;
1802
1803         genlmsg_end(msg, reply);
1804         return genlmsg_reply(msg, info);
1805
1806 fail:
1807         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1808         nlmsg_free(msg);
1809         return -EMSGSIZE;
1810 }
1811
1812 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk,
1813                                  struct mptcp_addr_info *addr)
1814 {
1815         struct mptcp_rm_list list = { .nr = 0 };
1816
1817         list.ids[list.nr++] = addr->id;
1818
1819         mptcp_pm_nl_rm_subflow_received(msk, &list);
1820         mptcp_pm_create_subflow_or_signal_addr(msk);
1821 }
1822
1823 static int mptcp_nl_set_flags(struct net *net,
1824                               struct mptcp_addr_info *addr,
1825                               u8 bkup, u8 changed)
1826 {
1827         long s_slot = 0, s_num = 0;
1828         struct mptcp_sock *msk;
1829         int ret = -EINVAL;
1830
1831         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1832                 struct sock *sk = (struct sock *)msk;
1833
1834                 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk))
1835                         goto next;
1836
1837                 lock_sock(sk);
1838                 spin_lock_bh(&msk->pm.lock);
1839                 if (changed & MPTCP_PM_ADDR_FLAG_BACKUP)
1840                         ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
1841                 if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)
1842                         mptcp_pm_nl_fullmesh(msk, addr);
1843                 spin_unlock_bh(&msk->pm.lock);
1844                 release_sock(sk);
1845
1846 next:
1847                 sock_put(sk);
1848                 cond_resched();
1849         }
1850
1851         return ret;
1852 }
1853
1854 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
1855 {
1856         struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry;
1857         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1858         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1859         u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP |
1860                            MPTCP_PM_ADDR_FLAG_FULLMESH;
1861         struct net *net = sock_net(skb->sk);
1862         u8 bkup = 0, lookup_by_id = 0;
1863         int ret;
1864
1865         ret = mptcp_pm_parse_entry(attr, info, false, &addr);
1866         if (ret < 0)
1867                 return ret;
1868
1869         if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1870                 bkup = 1;
1871         if (addr.addr.family == AF_UNSPEC) {
1872                 lookup_by_id = 1;
1873                 if (!addr.addr.id)
1874                         return -EOPNOTSUPP;
1875         }
1876
1877         spin_lock_bh(&pernet->lock);
1878         entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);
1879         if (!entry) {
1880                 spin_unlock_bh(&pernet->lock);
1881                 return -EINVAL;
1882         }
1883         if ((addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) &&
1884             (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1885                 spin_unlock_bh(&pernet->lock);
1886                 return -EINVAL;
1887         }
1888
1889         changed = (addr.flags ^ entry->flags) & mask;
1890         entry->flags = (entry->flags & ~mask) | (addr.flags & mask);
1891         addr = *entry;
1892         spin_unlock_bh(&pernet->lock);
1893
1894         mptcp_nl_set_flags(net, &addr.addr, bkup, changed);
1895         return 0;
1896 }
1897
1898 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1899 {
1900         genlmsg_multicast_netns(&mptcp_genl_family, net,
1901                                 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1902 }
1903
1904 bool mptcp_userspace_pm_active(const struct mptcp_sock *msk)
1905 {
1906         return genl_has_listeners(&mptcp_genl_family,
1907                                   sock_net((const struct sock *)msk),
1908                                   MPTCP_PM_EV_GRP_OFFSET);
1909 }
1910
1911 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1912 {
1913         const struct inet_sock *issk = inet_sk(ssk);
1914         const struct mptcp_subflow_context *sf;
1915
1916         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1917                 return -EMSGSIZE;
1918
1919         switch (ssk->sk_family) {
1920         case AF_INET:
1921                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1922                         return -EMSGSIZE;
1923                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1924                         return -EMSGSIZE;
1925                 break;
1926 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1927         case AF_INET6: {
1928                 const struct ipv6_pinfo *np = inet6_sk(ssk);
1929
1930                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1931                         return -EMSGSIZE;
1932                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1933                         return -EMSGSIZE;
1934                 break;
1935         }
1936 #endif
1937         default:
1938                 WARN_ON_ONCE(1);
1939                 return -EMSGSIZE;
1940         }
1941
1942         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1943                 return -EMSGSIZE;
1944         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
1945                 return -EMSGSIZE;
1946
1947         sf = mptcp_subflow_ctx(ssk);
1948         if (WARN_ON_ONCE(!sf))
1949                 return -EINVAL;
1950
1951         if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id))
1952                 return -EMSGSIZE;
1953
1954         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
1955                 return -EMSGSIZE;
1956
1957         return 0;
1958 }
1959
1960 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
1961                                          const struct mptcp_sock *msk,
1962                                          const struct sock *ssk)
1963 {
1964         const struct sock *sk = (const struct sock *)msk;
1965         const struct mptcp_subflow_context *sf;
1966         u8 sk_err;
1967
1968         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1969                 return -EMSGSIZE;
1970
1971         if (mptcp_event_add_subflow(skb, ssk))
1972                 return -EMSGSIZE;
1973
1974         sf = mptcp_subflow_ctx(ssk);
1975         if (WARN_ON_ONCE(!sf))
1976                 return -EINVAL;
1977
1978         if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
1979                 return -EMSGSIZE;
1980
1981         if (ssk->sk_bound_dev_if &&
1982             nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
1983                 return -EMSGSIZE;
1984
1985         sk_err = ssk->sk_err;
1986         if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
1987             nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
1988                 return -EMSGSIZE;
1989
1990         return 0;
1991 }
1992
1993 static int mptcp_event_sub_established(struct sk_buff *skb,
1994                                        const struct mptcp_sock *msk,
1995                                        const struct sock *ssk)
1996 {
1997         return mptcp_event_put_token_and_ssk(skb, msk, ssk);
1998 }
1999
2000 static int mptcp_event_sub_closed(struct sk_buff *skb,
2001                                   const struct mptcp_sock *msk,
2002                                   const struct sock *ssk)
2003 {
2004         const struct mptcp_subflow_context *sf;
2005
2006         if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
2007                 return -EMSGSIZE;
2008
2009         sf = mptcp_subflow_ctx(ssk);
2010         if (!sf->reset_seen)
2011                 return 0;
2012
2013         if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
2014                 return -EMSGSIZE;
2015
2016         if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
2017                 return -EMSGSIZE;
2018
2019         return 0;
2020 }
2021
2022 static int mptcp_event_created(struct sk_buff *skb,
2023                                const struct mptcp_sock *msk,
2024                                const struct sock *ssk)
2025 {
2026         int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
2027
2028         if (err)
2029                 return err;
2030
2031         if (nla_put_u8(skb, MPTCP_ATTR_SERVER_SIDE, READ_ONCE(msk->pm.server_side)))
2032                 return -EMSGSIZE;
2033
2034         return mptcp_event_add_subflow(skb, ssk);
2035 }
2036
2037 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
2038 {
2039         struct net *net = sock_net((const struct sock *)msk);
2040         struct nlmsghdr *nlh;
2041         struct sk_buff *skb;
2042
2043         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2044                 return;
2045
2046         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2047         if (!skb)
2048                 return;
2049
2050         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
2051         if (!nlh)
2052                 goto nla_put_failure;
2053
2054         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2055                 goto nla_put_failure;
2056
2057         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
2058                 goto nla_put_failure;
2059
2060         genlmsg_end(skb, nlh);
2061         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2062         return;
2063
2064 nla_put_failure:
2065         kfree_skb(skb);
2066 }
2067
2068 void mptcp_event_addr_announced(const struct sock *ssk,
2069                                 const struct mptcp_addr_info *info)
2070 {
2071         struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk);
2072         struct mptcp_sock *msk = mptcp_sk(subflow->conn);
2073         struct net *net = sock_net(ssk);
2074         struct nlmsghdr *nlh;
2075         struct sk_buff *skb;
2076
2077         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2078                 return;
2079
2080         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
2081         if (!skb)
2082                 return;
2083
2084         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
2085                           MPTCP_EVENT_ANNOUNCED);
2086         if (!nlh)
2087                 goto nla_put_failure;
2088
2089         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2090                 goto nla_put_failure;
2091
2092         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2093                 goto nla_put_failure;
2094
2095         if (nla_put_be16(skb, MPTCP_ATTR_DPORT,
2096                          info->port == 0 ?
2097                          inet_sk(ssk)->inet_dport :
2098                          info->port))
2099                 goto nla_put_failure;
2100
2101         switch (info->family) {
2102         case AF_INET:
2103                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2104                         goto nla_put_failure;
2105                 break;
2106 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2107         case AF_INET6:
2108                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2109                         goto nla_put_failure;
2110                 break;
2111 #endif
2112         default:
2113                 WARN_ON_ONCE(1);
2114                 goto nla_put_failure;
2115         }
2116
2117         genlmsg_end(skb, nlh);
2118         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2119         return;
2120
2121 nla_put_failure:
2122         kfree_skb(skb);
2123 }
2124
2125 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2126                  const struct sock *ssk, gfp_t gfp)
2127 {
2128         struct net *net = sock_net((const struct sock *)msk);
2129         struct nlmsghdr *nlh;
2130         struct sk_buff *skb;
2131
2132         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2133                 return;
2134
2135         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2136         if (!skb)
2137                 return;
2138
2139         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2140         if (!nlh)
2141                 goto nla_put_failure;
2142
2143         switch (type) {
2144         case MPTCP_EVENT_UNSPEC:
2145                 WARN_ON_ONCE(1);
2146                 break;
2147         case MPTCP_EVENT_CREATED:
2148         case MPTCP_EVENT_ESTABLISHED:
2149                 if (mptcp_event_created(skb, msk, ssk) < 0)
2150                         goto nla_put_failure;
2151                 break;
2152         case MPTCP_EVENT_CLOSED:
2153                 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
2154                         goto nla_put_failure;
2155                 break;
2156         case MPTCP_EVENT_ANNOUNCED:
2157         case MPTCP_EVENT_REMOVED:
2158                 /* call mptcp_event_addr_announced()/removed instead */
2159                 WARN_ON_ONCE(1);
2160                 break;
2161         case MPTCP_EVENT_SUB_ESTABLISHED:
2162         case MPTCP_EVENT_SUB_PRIORITY:
2163                 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2164                         goto nla_put_failure;
2165                 break;
2166         case MPTCP_EVENT_SUB_CLOSED:
2167                 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2168                         goto nla_put_failure;
2169                 break;
2170         }
2171
2172         genlmsg_end(skb, nlh);
2173         mptcp_nl_mcast_send(net, skb, gfp);
2174         return;
2175
2176 nla_put_failure:
2177         kfree_skb(skb);
2178 }
2179
2180 static const struct genl_small_ops mptcp_pm_ops[] = {
2181         {
2182                 .cmd    = MPTCP_PM_CMD_ADD_ADDR,
2183                 .doit   = mptcp_nl_cmd_add_addr,
2184                 .flags  = GENL_ADMIN_PERM,
2185         },
2186         {
2187                 .cmd    = MPTCP_PM_CMD_DEL_ADDR,
2188                 .doit   = mptcp_nl_cmd_del_addr,
2189                 .flags  = GENL_ADMIN_PERM,
2190         },
2191         {
2192                 .cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
2193                 .doit   = mptcp_nl_cmd_flush_addrs,
2194                 .flags  = GENL_ADMIN_PERM,
2195         },
2196         {
2197                 .cmd    = MPTCP_PM_CMD_GET_ADDR,
2198                 .doit   = mptcp_nl_cmd_get_addr,
2199                 .dumpit   = mptcp_nl_cmd_dump_addrs,
2200         },
2201         {
2202                 .cmd    = MPTCP_PM_CMD_SET_LIMITS,
2203                 .doit   = mptcp_nl_cmd_set_limits,
2204                 .flags  = GENL_ADMIN_PERM,
2205         },
2206         {
2207                 .cmd    = MPTCP_PM_CMD_GET_LIMITS,
2208                 .doit   = mptcp_nl_cmd_get_limits,
2209         },
2210         {
2211                 .cmd    = MPTCP_PM_CMD_SET_FLAGS,
2212                 .doit   = mptcp_nl_cmd_set_flags,
2213                 .flags  = GENL_ADMIN_PERM,
2214         },
2215         {
2216                 .cmd    = MPTCP_PM_CMD_ANNOUNCE,
2217                 .doit   = mptcp_nl_cmd_announce,
2218                 .flags  = GENL_ADMIN_PERM,
2219         },
2220         {
2221                 .cmd    = MPTCP_PM_CMD_REMOVE,
2222                 .doit   = mptcp_nl_cmd_remove,
2223                 .flags  = GENL_ADMIN_PERM,
2224         },
2225         {
2226                 .cmd    = MPTCP_PM_CMD_SUBFLOW_CREATE,
2227                 .doit   = mptcp_nl_cmd_sf_create,
2228                 .flags  = GENL_ADMIN_PERM,
2229         },
2230         {
2231                 .cmd    = MPTCP_PM_CMD_SUBFLOW_DESTROY,
2232                 .doit   = mptcp_nl_cmd_sf_destroy,
2233                 .flags  = GENL_ADMIN_PERM,
2234         },
2235 };
2236
2237 static struct genl_family mptcp_genl_family __ro_after_init = {
2238         .name           = MPTCP_PM_NAME,
2239         .version        = MPTCP_PM_VER,
2240         .maxattr        = MPTCP_PM_ATTR_MAX,
2241         .policy         = mptcp_pm_policy,
2242         .netnsok        = true,
2243         .module         = THIS_MODULE,
2244         .small_ops      = mptcp_pm_ops,
2245         .n_small_ops    = ARRAY_SIZE(mptcp_pm_ops),
2246         .mcgrps         = mptcp_pm_mcgrps,
2247         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
2248 };
2249
2250 static int __net_init pm_nl_init_net(struct net *net)
2251 {
2252         struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2253
2254         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2255
2256         /* Cit. 2 subflows ought to be enough for anybody. */
2257         pernet->subflows_max = 2;
2258         pernet->next_id = 1;
2259         pernet->stale_loss_cnt = 4;
2260         spin_lock_init(&pernet->lock);
2261
2262         /* No need to initialize other pernet fields, the struct is zeroed at
2263          * allocation time.
2264          */
2265
2266         return 0;
2267 }
2268
2269 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2270 {
2271         struct net *net;
2272
2273         list_for_each_entry(net, net_list, exit_list) {
2274                 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net);
2275
2276                 /* net is removed from namespace list, can't race with
2277                  * other modifiers, also netns core already waited for a
2278                  * RCU grace period.
2279                  */
2280                 __flush_addrs(&pernet->local_addr_list);
2281         }
2282 }
2283
2284 static struct pernet_operations mptcp_pm_pernet_ops = {
2285         .init = pm_nl_init_net,
2286         .exit_batch = pm_nl_exit_net,
2287         .id = &pm_nl_pernet_id,
2288         .size = sizeof(struct pm_nl_pernet),
2289 };
2290
2291 void __init mptcp_pm_nl_init(void)
2292 {
2293         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2294                 panic("Failed to register MPTCP PM pernet subsystem.\n");
2295
2296         if (genl_register_family(&mptcp_genl_family))
2297                 panic("Failed to register MPTCP PM netlink family\n");
2298 }