net/mptcp/pm_netlink.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /* Multipath TCP
   3  *
   4  * Copyright (c) 2020, Red Hat, Inc.
   5  */
   6
   7 #define pr_fmt(fmt) "MPTCP: " fmt
   8
   9 #include <linux/inet.h>
  10 #include <linux/kernel.h>
  11 #include <net/tcp.h>
  12 #include <net/netns/generic.h>
  13 #include <net/mptcp.h>
  14 #include <net/genetlink.h>
  15 #include <uapi/linux/mptcp.h>
  16
  17 #include "protocol.h"
  18 #include "mib.h"
  19
  20 /* forward declaration */
  21 static struct genl_family mptcp_genl_family;
  22
  23 static int pm_nl_pernet_id;
  24
  25 struct mptcp_pm_addr_entry {
  26         struct list_head        list;
  27         struct mptcp_addr_info  addr;
  28         u8                      flags;
  29         int                     ifindex;
  30         struct socket           *lsk;
  31 };
  32
  33 struct mptcp_pm_add_entry {
  34         struct list_head        list;
  35         struct mptcp_addr_info  addr;
  36         struct timer_list       add_timer;
  37         struct mptcp_sock       *sock;
  38         u8                      retrans_times;
  39 };
  40
  41 struct pm_nl_pernet {
  42         /* protects pernet updates */
  43         spinlock_t              lock;
  44         struct list_head        local_addr_list;
  45         unsigned int            addrs;
  46         unsigned int            stale_loss_cnt;
  47         unsigned int            add_addr_signal_max;
  48         unsigned int            add_addr_accept_max;
  49         unsigned int            local_addr_max;
  50         unsigned int            subflows_max;
  51         unsigned int            next_id;
  52         DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
  53 };
  54
  55 #define MPTCP_PM_ADDR_MAX       8
  56 #define ADD_ADDR_RETRANS_MAX    3
  57
  58 static bool addresses_equal(const struct mptcp_addr_info *a,
  59                             const struct mptcp_addr_info *b, bool use_port)
  60 {
  61         bool addr_equals = false;
  62
  63         if (a->family == b->family) {
  64                 if (a->family == AF_INET)
  65                         addr_equals = a->addr.s_addr == b->addr.s_addr;
  66 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
  67                 else
  68                         addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6);
  69         } else if (a->family == AF_INET) {
  70                 if (ipv6_addr_v4mapped(&b->addr6))
  71                         addr_equals = a->addr.s_addr == b->addr6.s6_addr32[3];
  72         } else if (b->family == AF_INET) {
  73                 if (ipv6_addr_v4mapped(&a->addr6))
  74                         addr_equals = a->addr6.s6_addr32[3] == b->addr.s_addr;
  75 #endif
  76         }
  77
  78         if (!addr_equals)
  79                 return false;
  80         if (!use_port)
  81                 return true;
  82
  83         return a->port == b->port;
  84 }
  85
  86 static bool address_zero(const struct mptcp_addr_info *addr)
  87 {
  88         struct mptcp_addr_info zero;
  89
  90         memset(&zero, 0, sizeof(zero));
  91         zero.family = addr->family;
  92
  93         return addresses_equal(addr, &zero, true);
  94 }
  95
  96 static void local_address(const struct sock_common *skc,
  97                           struct mptcp_addr_info *addr)
  98 {
  99         addr->family = skc->skc_family;
 100         addr->port = htons(skc->skc_num);
 101         if (addr->family == AF_INET)
 102                 addr->addr.s_addr = skc->skc_rcv_saddr;
 103 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 104         else if (addr->family == AF_INET6)
 105                 addr->addr6 = skc->skc_v6_rcv_saddr;
 106 #endif
 107 }
 108
 109 static void remote_address(const struct sock_common *skc,
 110                            struct mptcp_addr_info *addr)
 111 {
 112         addr->family = skc->skc_family;
 113         addr->port = skc->skc_dport;
 114         if (addr->family == AF_INET)
 115                 addr->addr.s_addr = skc->skc_daddr;
 116 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 117         else if (addr->family == AF_INET6)
 118                 addr->addr6 = skc->skc_v6_daddr;
 119 #endif
 120 }
 121
 122 static bool lookup_subflow_by_saddr(const struct list_head *list,
 123                                     struct mptcp_addr_info *saddr)
 124 {
 125         struct mptcp_subflow_context *subflow;
 126         struct mptcp_addr_info cur;
 127         struct sock_common *skc;
 128
 129         list_for_each_entry(subflow, list, node) {
 130                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 131
 132                 local_address(skc, &cur);
 133                 if (addresses_equal(&cur, saddr, saddr->port))
 134                         return true;
 135         }
 136
 137         return false;
 138 }
 139
 140 static bool lookup_subflow_by_daddr(const struct list_head *list,
 141                                     struct mptcp_addr_info *daddr)
 142 {
 143         struct mptcp_subflow_context *subflow;
 144         struct mptcp_addr_info cur;
 145         struct sock_common *skc;
 146
 147         list_for_each_entry(subflow, list, node) {
 148                 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow);
 149
 150                 remote_address(skc, &cur);
 151                 if (addresses_equal(&cur, daddr, daddr->port))
 152                         return true;
 153         }
 154
 155         return false;
 156 }
 157
 158 static struct mptcp_pm_addr_entry *
 159 select_local_address(const struct pm_nl_pernet *pernet,
 160                      struct mptcp_sock *msk)
 161 {
 162         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 163         struct sock *sk = (struct sock *)msk;
 164
 165         msk_owned_by_me(msk);
 166
 167         rcu_read_lock();
 168         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 169                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW))
 170                         continue;
 171
 172                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 173                         continue;
 174
 175                 if (entry->addr.family != sk->sk_family) {
 176 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 177                         if ((entry->addr.family == AF_INET &&
 178                              !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
 179                             (sk->sk_family == AF_INET &&
 180                              !ipv6_addr_v4mapped(&entry->addr.addr6)))
 181 #endif
 182                                 continue;
 183                 }
 184
 185                 ret = entry;
 186                 break;
 187         }
 188         rcu_read_unlock();
 189         return ret;
 190 }
 191
 192 static struct mptcp_pm_addr_entry *
 193 select_signal_address(struct pm_nl_pernet *pernet, struct mptcp_sock *msk)
 194 {
 195         struct mptcp_pm_addr_entry *entry, *ret = NULL;
 196
 197         rcu_read_lock();
 198         /* do not keep any additional per socket state, just signal
 199          * the address list in order.
 200          * Note: removal from the local address list during the msk life-cycle
 201          * can lead to additional addresses not being announced.
 202          */
 203         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 204                 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap))
 205                         continue;
 206
 207                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL))
 208                         continue;
 209
 210                 ret = entry;
 211                 break;
 212         }
 213         rcu_read_unlock();
 214         return ret;
 215 }
 216
 217 unsigned int mptcp_pm_get_add_addr_signal_max(struct mptcp_sock *msk)
 218 {
 219         struct pm_nl_pernet *pernet;
 220
 221         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 222         return READ_ONCE(pernet->add_addr_signal_max);
 223 }
 224 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_signal_max);
 225
 226 unsigned int mptcp_pm_get_add_addr_accept_max(struct mptcp_sock *msk)
 227 {
 228         struct pm_nl_pernet *pernet;
 229
 230         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 231         return READ_ONCE(pernet->add_addr_accept_max);
 232 }
 233 EXPORT_SYMBOL_GPL(mptcp_pm_get_add_addr_accept_max);
 234
 235 unsigned int mptcp_pm_get_subflows_max(struct mptcp_sock *msk)
 236 {
 237         struct pm_nl_pernet *pernet;
 238
 239         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 240         return READ_ONCE(pernet->subflows_max);
 241 }
 242 EXPORT_SYMBOL_GPL(mptcp_pm_get_subflows_max);
 243
 244 unsigned int mptcp_pm_get_local_addr_max(struct mptcp_sock *msk)
 245 {
 246         struct pm_nl_pernet *pernet;
 247
 248         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 249         return READ_ONCE(pernet->local_addr_max);
 250 }
 251 EXPORT_SYMBOL_GPL(mptcp_pm_get_local_addr_max);
 252
 253 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk)
 254 {
 255         struct pm_nl_pernet *pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
 256
 257         if (msk->pm.subflows == mptcp_pm_get_subflows_max(msk) ||
 258             (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap,
 259                                MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) {
 260                 WRITE_ONCE(msk->pm.work_pending, false);
 261                 return false;
 262         }
 263         return true;
 264 }
 265
 266 struct mptcp_pm_add_entry *
 267 mptcp_lookup_anno_list_by_saddr(struct mptcp_sock *msk,
 268                                 struct mptcp_addr_info *addr)
 269 {
 270         struct mptcp_pm_add_entry *entry;
 271
 272         lockdep_assert_held(&msk->pm.lock);
 273
 274         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 275                 if (addresses_equal(&entry->addr, addr, true))
 276                         return entry;
 277         }
 278
 279         return NULL;
 280 }
 281
 282 bool mptcp_pm_sport_in_anno_list(struct mptcp_sock *msk, const struct sock *sk)
 283 {
 284         struct mptcp_pm_add_entry *entry;
 285         struct mptcp_addr_info saddr;
 286         bool ret = false;
 287
 288         local_address((struct sock_common *)sk, &saddr);
 289
 290         spin_lock_bh(&msk->pm.lock);
 291         list_for_each_entry(entry, &msk->pm.anno_list, list) {
 292                 if (addresses_equal(&entry->addr, &saddr, true)) {
 293                         ret = true;
 294                         goto out;
 295                 }
 296         }
 297
 298 out:
 299         spin_unlock_bh(&msk->pm.lock);
 300         return ret;
 301 }
 302
 303 static void mptcp_pm_add_timer(struct timer_list *timer)
 304 {
 305         struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer);
 306         struct mptcp_sock *msk = entry->sock;
 307         struct sock *sk = (struct sock *)msk;
 308
 309         pr_debug("msk=%p", msk);
 310
 311         if (!msk)
 312                 return;
 313
 314         if (inet_sk_state_load(sk) == TCP_CLOSE)
 315                 return;
 316
 317         if (!entry->addr.id)
 318                 return;
 319
 320         if (mptcp_pm_should_add_signal_addr(msk)) {
 321                 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8);
 322                 goto out;
 323         }
 324
 325         spin_lock_bh(&msk->pm.lock);
 326
 327         if (!mptcp_pm_should_add_signal_addr(msk)) {
 328                 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id);
 329                 mptcp_pm_announce_addr(msk, &entry->addr, false);
 330                 mptcp_pm_add_addr_send_ack(msk);
 331                 entry->retrans_times++;
 332         }
 333
 334         if (entry->retrans_times < ADD_ADDR_RETRANS_MAX)
 335                 sk_reset_timer(sk, timer,
 336                                jiffies + mptcp_get_add_addr_timeout(sock_net(sk)));
 337
 338         spin_unlock_bh(&msk->pm.lock);
 339
 340         if (entry->retrans_times == ADD_ADDR_RETRANS_MAX)
 341                 mptcp_pm_subflow_established(msk);
 342
 343 out:
 344         __sock_put(sk);
 345 }
 346
 347 struct mptcp_pm_add_entry *
 348 mptcp_pm_del_add_timer(struct mptcp_sock *msk,
 349                        struct mptcp_addr_info *addr, bool check_id)
 350 {
 351         struct mptcp_pm_add_entry *entry;
 352         struct sock *sk = (struct sock *)msk;
 353
 354         spin_lock_bh(&msk->pm.lock);
 355         entry = mptcp_lookup_anno_list_by_saddr(msk, addr);
 356         if (entry && (!check_id || entry->addr.id == addr->id))
 357                 entry->retrans_times = ADD_ADDR_RETRANS_MAX;
 358         spin_unlock_bh(&msk->pm.lock);
 359
 360         if (entry && (!check_id || entry->addr.id == addr->id))
 361                 sk_stop_timer_sync(sk, &entry->add_timer);
 362
 363         return entry;
 364 }
 365
 366 static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk,
 367                                      struct mptcp_pm_addr_entry *entry)
 368 {
 369         struct mptcp_pm_add_entry *add_entry = NULL;
 370         struct sock *sk = (struct sock *)msk;
 371         struct net *net = sock_net(sk);
 372
 373         lockdep_assert_held(&msk->pm.lock);
 374
 375         if (mptcp_lookup_anno_list_by_saddr(msk, &entry->addr))
 376                 return false;
 377
 378         add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC);
 379         if (!add_entry)
 380                 return false;
 381
 382         list_add(&add_entry->list, &msk->pm.anno_list);
 383
 384         add_entry->addr = entry->addr;
 385         add_entry->sock = msk;
 386         add_entry->retrans_times = 0;
 387
 388         timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0);
 389         sk_reset_timer(sk, &add_entry->add_timer,
 390                        jiffies + mptcp_get_add_addr_timeout(net));
 391
 392         return true;
 393 }
 394
 395 void mptcp_pm_free_anno_list(struct mptcp_sock *msk)
 396 {
 397         struct mptcp_pm_add_entry *entry, *tmp;
 398         struct sock *sk = (struct sock *)msk;
 399         LIST_HEAD(free_list);
 400
 401         pr_debug("msk=%p", msk);
 402
 403         spin_lock_bh(&msk->pm.lock);
 404         list_splice_init(&msk->pm.anno_list, &free_list);
 405         spin_unlock_bh(&msk->pm.lock);
 406
 407         list_for_each_entry_safe(entry, tmp, &free_list, list) {
 408                 sk_stop_timer_sync(sk, &entry->add_timer);
 409                 kfree(entry);
 410         }
 411 }
 412
 413 static bool lookup_address_in_vec(struct mptcp_addr_info *addrs, unsigned int nr,
 414                                   struct mptcp_addr_info *addr)
 415 {
 416         int i;
 417
 418         for (i = 0; i < nr; i++) {
 419                 if (addresses_equal(&addrs[i], addr, addr->port))
 420                         return true;
 421         }
 422
 423         return false;
 424 }
 425
 426 /* Fill all the remote addresses into the array addrs[],
 427  * and return the array size.
 428  */
 429 static unsigned int fill_remote_addresses_vec(struct mptcp_sock *msk, bool fullmesh,
 430                                               struct mptcp_addr_info *addrs)
 431 {
 432         bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0);
 433         struct sock *sk = (struct sock *)msk, *ssk;
 434         struct mptcp_subflow_context *subflow;
 435         struct mptcp_addr_info remote = { 0 };
 436         unsigned int subflows_max;
 437         int i = 0;
 438
 439         subflows_max = mptcp_pm_get_subflows_max(msk);
 440         remote_address((struct sock_common *)sk, &remote);
 441
 442         /* Non-fullmesh endpoint, fill in the single entry
 443          * corresponding to the primary MPC subflow remote address
 444          */
 445         if (!fullmesh) {
 446                 if (deny_id0)
 447                         return 0;
 448
 449                 msk->pm.subflows++;
 450                 addrs[i++] = remote;
 451         } else {
 452                 mptcp_for_each_subflow(msk, subflow) {
 453                         ssk = mptcp_subflow_tcp_sock(subflow);
 454                         remote_address((struct sock_common *)ssk, &addrs[i]);
 455                         if (deny_id0 && addresses_equal(&addrs[i], &remote, false))
 456                                 continue;
 457
 458                         if (!lookup_address_in_vec(addrs, i, &addrs[i]) &&
 459                             msk->pm.subflows < subflows_max) {
 460                                 msk->pm.subflows++;
 461                                 i++;
 462                         }
 463                 }
 464         }
 465
 466         return i;
 467 }
 468
 469 static struct mptcp_pm_addr_entry *
 470 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id)
 471 {
 472         struct mptcp_pm_addr_entry *entry;
 473
 474         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 475                 if (entry->addr.id == id)
 476                         return entry;
 477         }
 478         return NULL;
 479 }
 480
 481 static struct mptcp_pm_addr_entry *
 482 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info,
 483               bool lookup_by_id)
 484 {
 485         struct mptcp_pm_addr_entry *entry;
 486
 487         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 488                 if ((!lookup_by_id && addresses_equal(&entry->addr, info, true)) ||
 489                     (lookup_by_id && entry->addr.id == info->id))
 490                         return entry;
 491         }
 492         return NULL;
 493 }
 494
 495 static int
 496 lookup_id_by_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *addr)
 497 {
 498         struct mptcp_pm_addr_entry *entry;
 499         int ret = -1;
 500
 501         rcu_read_lock();
 502         list_for_each_entry(entry, &pernet->local_addr_list, list) {
 503                 if (addresses_equal(&entry->addr, addr, entry->addr.port)) {
 504                         ret = entry->addr.id;
 505                         break;
 506                 }
 507         }
 508         rcu_read_unlock();
 509         return ret;
 510 }
 511
 512 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk)
 513 {
 514         struct sock *sk = (struct sock *)msk;
 515         struct mptcp_pm_addr_entry *local;
 516         unsigned int add_addr_signal_max;
 517         unsigned int local_addr_max;
 518         struct pm_nl_pernet *pernet;
 519         unsigned int subflows_max;
 520
 521         pernet = net_generic(sock_net(sk), pm_nl_pernet_id);
 522
 523         add_addr_signal_max = mptcp_pm_get_add_addr_signal_max(msk);
 524         local_addr_max = mptcp_pm_get_local_addr_max(msk);
 525         subflows_max = mptcp_pm_get_subflows_max(msk);
 526
 527         /* do lazy endpoint usage accounting for the MPC subflows */
 528         if (unlikely(!(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED))) && msk->first) {
 529                 struct mptcp_addr_info mpc_addr;
 530                 int mpc_id;
 531
 532                 local_address((struct sock_common *)msk->first, &mpc_addr);
 533                 mpc_id = lookup_id_by_addr(pernet, &mpc_addr);
 534                 if (mpc_id >= 0)
 535                         __clear_bit(mpc_id, msk->pm.id_avail_bitmap);
 536
 537                 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED);
 538         }
 539
 540         pr_debug("local %d:%d signal %d:%d subflows %d:%d\n",
 541                  msk->pm.local_addr_used, local_addr_max,
 542                  msk->pm.add_addr_signaled, add_addr_signal_max,
 543                  msk->pm.subflows, subflows_max);
 544
 545         /* check first for announce */
 546         if (msk->pm.add_addr_signaled < add_addr_signal_max) {
 547                 local = select_signal_address(pernet, msk);
 548
 549                 /* due to racing events on both ends we can reach here while
 550                  * previous add address is still running: if we invoke now
 551                  * mptcp_pm_announce_addr(), that will fail and the
 552                  * corresponding id will be marked as used.
 553                  * Instead let the PM machinery reschedule us when the
 554                  * current address announce will be completed.
 555                  */
 556                 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL))
 557                         return;
 558
 559                 if (local) {
 560                         if (mptcp_pm_alloc_anno_list(msk, local)) {
 561                                 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 562                                 msk->pm.add_addr_signaled++;
 563                                 mptcp_pm_announce_addr(msk, &local->addr, false);
 564                                 mptcp_pm_nl_addr_send_ack(msk);
 565                         }
 566                 }
 567         }
 568
 569         /* check if should create a new subflow */
 570         while (msk->pm.local_addr_used < local_addr_max &&
 571                msk->pm.subflows < subflows_max) {
 572                 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 573                 bool fullmesh;
 574                 int i, nr;
 575
 576                 local = select_local_address(pernet, msk);
 577                 if (!local)
 578                         break;
 579
 580                 fullmesh = !!(local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH);
 581
 582                 msk->pm.local_addr_used++;
 583                 nr = fill_remote_addresses_vec(msk, fullmesh, addrs);
 584                 if (nr)
 585                         __clear_bit(local->addr.id, msk->pm.id_avail_bitmap);
 586                 spin_unlock_bh(&msk->pm.lock);
 587                 for (i = 0; i < nr; i++)
 588                         __mptcp_subflow_connect(sk, &local->addr, &addrs[i]);
 589                 spin_lock_bh(&msk->pm.lock);
 590         }
 591         mptcp_pm_nl_check_work_pending(msk);
 592 }
 593
 594 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk)
 595 {
 596         mptcp_pm_create_subflow_or_signal_addr(msk);
 597 }
 598
 599 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk)
 600 {
 601         mptcp_pm_create_subflow_or_signal_addr(msk);
 602 }
 603
 604 /* Fill all the local addresses into the array addrs[],
 605  * and return the array size.
 606  */
 607 static unsigned int fill_local_addresses_vec(struct mptcp_sock *msk,
 608                                              struct mptcp_addr_info *addrs)
 609 {
 610         struct sock *sk = (struct sock *)msk;
 611         struct mptcp_pm_addr_entry *entry;
 612         struct mptcp_addr_info local;
 613         struct pm_nl_pernet *pernet;
 614         unsigned int subflows_max;
 615         int i = 0;
 616
 617         pernet = net_generic(sock_net(sk), pm_nl_pernet_id);
 618         subflows_max = mptcp_pm_get_subflows_max(msk);
 619
 620         rcu_read_lock();
 621         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
 622                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH))
 623                         continue;
 624
 625                 if (entry->addr.family != sk->sk_family) {
 626 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 627                         if ((entry->addr.family == AF_INET &&
 628                              !ipv6_addr_v4mapped(&sk->sk_v6_daddr)) ||
 629                             (sk->sk_family == AF_INET &&
 630                              !ipv6_addr_v4mapped(&entry->addr.addr6)))
 631 #endif
 632                                 continue;
 633                 }
 634
 635                 if (msk->pm.subflows < subflows_max) {
 636                         msk->pm.subflows++;
 637                         addrs[i++] = entry->addr;
 638                 }
 639         }
 640         rcu_read_unlock();
 641
 642         /* If the array is empty, fill in the single
 643          * 'IPADDRANY' local address
 644          */
 645         if (!i) {
 646                 memset(&local, 0, sizeof(local));
 647                 local.family = msk->pm.remote.family;
 648
 649                 msk->pm.subflows++;
 650                 addrs[i++] = local;
 651         }
 652
 653         return i;
 654 }
 655
 656 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk)
 657 {
 658         struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX];
 659         struct sock *sk = (struct sock *)msk;
 660         unsigned int add_addr_accept_max;
 661         struct mptcp_addr_info remote;
 662         unsigned int subflows_max;
 663         bool reset_port = false;
 664         int i, nr;
 665
 666         add_addr_accept_max = mptcp_pm_get_add_addr_accept_max(msk);
 667         subflows_max = mptcp_pm_get_subflows_max(msk);
 668
 669         pr_debug("accepted %d:%d remote family %d",
 670                  msk->pm.add_addr_accepted, add_addr_accept_max,
 671                  msk->pm.remote.family);
 672
 673         remote = msk->pm.remote;
 674         if (lookup_subflow_by_daddr(&msk->conn_list, &remote))
 675                 goto add_addr_echo;
 676
 677         /* pick id 0 port, if none is provided the remote address */
 678         if (!remote.port) {
 679                 reset_port = true;
 680                 remote.port = sk->sk_dport;
 681         }
 682
 683         /* connect to the specified remote address, using whatever
 684          * local address the routing configuration will pick.
 685          */
 686         nr = fill_local_addresses_vec(msk, addrs);
 687
 688         msk->pm.add_addr_accepted++;
 689         if (msk->pm.add_addr_accepted >= add_addr_accept_max ||
 690             msk->pm.subflows >= subflows_max)
 691                 WRITE_ONCE(msk->pm.accept_addr, false);
 692
 693         spin_unlock_bh(&msk->pm.lock);
 694         for (i = 0; i < nr; i++)
 695                 __mptcp_subflow_connect(sk, &addrs[i], &remote);
 696         spin_lock_bh(&msk->pm.lock);
 697
 698         /* be sure to echo exactly the received address */
 699         if (reset_port)
 700                 remote.port = 0;
 701
 702 add_addr_echo:
 703         mptcp_pm_announce_addr(msk, &remote, true);
 704         mptcp_pm_nl_addr_send_ack(msk);
 705 }
 706
 707 void mptcp_pm_nl_addr_send_ack(struct mptcp_sock *msk)
 708 {
 709         struct mptcp_subflow_context *subflow;
 710
 711         msk_owned_by_me(msk);
 712         lockdep_assert_held(&msk->pm.lock);
 713
 714         if (!mptcp_pm_should_add_signal(msk) &&
 715             !mptcp_pm_should_rm_signal(msk))
 716                 return;
 717
 718         subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node);
 719         if (subflow) {
 720                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 721
 722                 spin_unlock_bh(&msk->pm.lock);
 723                 pr_debug("send ack for %s",
 724                          mptcp_pm_should_add_signal(msk) ? "add_addr" : "rm_addr");
 725
 726                 mptcp_subflow_send_ack(ssk);
 727                 spin_lock_bh(&msk->pm.lock);
 728         }
 729 }
 730
 731 static int mptcp_pm_nl_mp_prio_send_ack(struct mptcp_sock *msk,
 732                                         struct mptcp_addr_info *addr,
 733                                         u8 bkup)
 734 {
 735         struct mptcp_subflow_context *subflow;
 736
 737         pr_debug("bkup=%d", bkup);
 738
 739         mptcp_for_each_subflow(msk, subflow) {
 740                 struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 741                 struct sock *sk = (struct sock *)msk;
 742                 struct mptcp_addr_info local;
 743
 744                 local_address((struct sock_common *)ssk, &local);
 745                 if (!addresses_equal(&local, addr, addr->port))
 746                         continue;
 747
 748                 subflow->backup = bkup;
 749                 subflow->send_mp_prio = 1;
 750                 subflow->request_bkup = bkup;
 751                 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPPRIOTX);
 752
 753                 spin_unlock_bh(&msk->pm.lock);
 754                 pr_debug("send ack for mp_prio");
 755                 mptcp_subflow_send_ack(ssk);
 756                 spin_lock_bh(&msk->pm.lock);
 757
 758                 return 0;
 759         }
 760
 761         return -EINVAL;
 762 }
 763
 764 static void mptcp_pm_nl_rm_addr_or_subflow(struct mptcp_sock *msk,
 765                                            const struct mptcp_rm_list *rm_list,
 766                                            enum linux_mptcp_mib_field rm_type)
 767 {
 768         struct mptcp_subflow_context *subflow, *tmp;
 769         struct sock *sk = (struct sock *)msk;
 770         u8 i;
 771
 772         pr_debug("%s rm_list_nr %d",
 773                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow", rm_list->nr);
 774
 775         msk_owned_by_me(msk);
 776
 777         if (sk->sk_state == TCP_LISTEN)
 778                 return;
 779
 780         if (!rm_list->nr)
 781                 return;
 782
 783         if (list_empty(&msk->conn_list))
 784                 return;
 785
 786         for (i = 0; i < rm_list->nr; i++) {
 787                 bool removed = false;
 788
 789                 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) {
 790                         struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 791                         int how = RCV_SHUTDOWN | SEND_SHUTDOWN;
 792                         u8 id = subflow->local_id;
 793
 794                         if (rm_type == MPTCP_MIB_RMADDR)
 795                                 id = subflow->remote_id;
 796
 797                         if (rm_list->ids[i] != id)
 798                                 continue;
 799
 800                         pr_debug(" -> %s rm_list_ids[%d]=%u local_id=%u remote_id=%u",
 801                                  rm_type == MPTCP_MIB_RMADDR ? "address" : "subflow",
 802                                  i, rm_list->ids[i], subflow->local_id, subflow->remote_id);
 803                         spin_unlock_bh(&msk->pm.lock);
 804                         mptcp_subflow_shutdown(sk, ssk, how);
 805
 806                         /* the following takes care of updating the subflows counter */
 807                         mptcp_close_ssk(sk, ssk, subflow);
 808                         spin_lock_bh(&msk->pm.lock);
 809
 810                         removed = true;
 811                         __MPTCP_INC_STATS(sock_net(sk), rm_type);
 812                 }
 813                 __set_bit(rm_list->ids[i], msk->pm.id_avail_bitmap);
 814                 if (!removed)
 815                         continue;
 816
 817                 if (rm_type == MPTCP_MIB_RMADDR) {
 818                         msk->pm.add_addr_accepted--;
 819                         WRITE_ONCE(msk->pm.accept_addr, true);
 820                 } else if (rm_type == MPTCP_MIB_RMSUBFLOW) {
 821                         msk->pm.local_addr_used--;
 822                 }
 823         }
 824 }
 825
 826 static void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk)
 827 {
 828         mptcp_pm_nl_rm_addr_or_subflow(msk, &msk->pm.rm_list_rx, MPTCP_MIB_RMADDR);
 829 }
 830
 831 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk,
 832                                      const struct mptcp_rm_list *rm_list)
 833 {
 834         mptcp_pm_nl_rm_addr_or_subflow(msk, rm_list, MPTCP_MIB_RMSUBFLOW);
 835 }
 836
 837 void mptcp_pm_nl_work(struct mptcp_sock *msk)
 838 {
 839         struct mptcp_pm_data *pm = &msk->pm;
 840
 841         msk_owned_by_me(msk);
 842
 843         if (!(pm->status & MPTCP_PM_WORK_MASK))
 844                 return;
 845
 846         spin_lock_bh(&msk->pm.lock);
 847
 848         pr_debug("msk=%p status=%x", msk, pm->status);
 849         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) {
 850                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED);
 851                 mptcp_pm_nl_add_addr_received(msk);
 852         }
 853         if (pm->status & BIT(MPTCP_PM_ADD_ADDR_SEND_ACK)) {
 854                 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_SEND_ACK);
 855                 mptcp_pm_nl_addr_send_ack(msk);
 856         }
 857         if (pm->status & BIT(MPTCP_PM_RM_ADDR_RECEIVED)) {
 858                 pm->status &= ~BIT(MPTCP_PM_RM_ADDR_RECEIVED);
 859                 mptcp_pm_nl_rm_addr_received(msk);
 860         }
 861         if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) {
 862                 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED);
 863                 mptcp_pm_nl_fully_established(msk);
 864         }
 865         if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) {
 866                 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED);
 867                 mptcp_pm_nl_subflow_established(msk);
 868         }
 869
 870         spin_unlock_bh(&msk->pm.lock);
 871 }
 872
 873 static bool address_use_port(struct mptcp_pm_addr_entry *entry)
 874 {
 875         return (entry->flags &
 876                 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) ==
 877                 MPTCP_PM_ADDR_FLAG_SIGNAL;
 878 }
 879
 880 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet,
 881                                              struct mptcp_pm_addr_entry *entry)
 882 {
 883         struct mptcp_pm_addr_entry *cur;
 884         unsigned int addr_max;
 885         int ret = -EINVAL;
 886
 887         spin_lock_bh(&pernet->lock);
 888         /* to keep the code simple, don't do IDR-like allocation for address ID,
 889          * just bail when we exceed limits
 890          */
 891         if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID)
 892                 pernet->next_id = 1;
 893         if (pernet->addrs >= MPTCP_PM_ADDR_MAX)
 894                 goto out;
 895         if (test_bit(entry->addr.id, pernet->id_bitmap))
 896                 goto out;
 897
 898         /* do not insert duplicate address, differentiate on port only
 899          * singled addresses
 900          */
 901         list_for_each_entry(cur, &pernet->local_addr_list, list) {
 902                 if (addresses_equal(&cur->addr, &entry->addr,
 903                                     address_use_port(entry) &&
 904                                     address_use_port(cur)))
 905                         goto out;
 906         }
 907
 908         if (!entry->addr.id) {
 909 find_next:
 910                 entry->addr.id = find_next_zero_bit(pernet->id_bitmap,
 911                                                     MPTCP_PM_MAX_ADDR_ID + 1,
 912                                                     pernet->next_id);
 913                 if (!entry->addr.id && pernet->next_id != 1) {
 914                         pernet->next_id = 1;
 915                         goto find_next;
 916                 }
 917         }
 918
 919         if (!entry->addr.id)
 920                 goto out;
 921
 922         __set_bit(entry->addr.id, pernet->id_bitmap);
 923         if (entry->addr.id > pernet->next_id)
 924                 pernet->next_id = entry->addr.id;
 925
 926         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
 927                 addr_max = pernet->add_addr_signal_max;
 928                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max + 1);
 929         }
 930         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
 931                 addr_max = pernet->local_addr_max;
 932                 WRITE_ONCE(pernet->local_addr_max, addr_max + 1);
 933         }
 934
 935         pernet->addrs++;
 936         list_add_tail_rcu(&entry->list, &pernet->local_addr_list);
 937         ret = entry->addr.id;
 938
 939 out:
 940         spin_unlock_bh(&pernet->lock);
 941         return ret;
 942 }
 943
 944 static int mptcp_pm_nl_create_listen_socket(struct sock *sk,
 945                                             struct mptcp_pm_addr_entry *entry)
 946 {
 947         int addrlen = sizeof(struct sockaddr_in);
 948         struct sockaddr_storage addr;
 949         struct mptcp_sock *msk;
 950         struct socket *ssock;
 951         int backlog = 1024;
 952         int err;
 953
 954         err = sock_create_kern(sock_net(sk), entry->addr.family,
 955                                SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk);
 956         if (err)
 957                 return err;
 958
 959         msk = mptcp_sk(entry->lsk->sk);
 960         if (!msk) {
 961                 err = -EINVAL;
 962                 goto out;
 963         }
 964
 965         ssock = __mptcp_nmpc_socket(msk);
 966         if (!ssock) {
 967                 err = -EINVAL;
 968                 goto out;
 969         }
 970
 971         mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family);
 972 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
 973         if (entry->addr.family == AF_INET6)
 974                 addrlen = sizeof(struct sockaddr_in6);
 975 #endif
 976         err = kernel_bind(ssock, (struct sockaddr *)&addr, addrlen);
 977         if (err) {
 978                 pr_warn("kernel_bind error, err=%d", err);
 979                 goto out;
 980         }
 981
 982         err = kernel_listen(ssock, backlog);
 983         if (err) {
 984                 pr_warn("kernel_listen error, err=%d", err);
 985                 goto out;
 986         }
 987
 988         return 0;
 989
 990 out:
 991         sock_release(entry->lsk);
 992         return err;
 993 }
 994
 995 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc)
 996 {
 997         struct mptcp_pm_addr_entry *entry;
 998         struct mptcp_addr_info skc_local;
 999         struct mptcp_addr_info msk_local;
1000         struct pm_nl_pernet *pernet;
1001         int ret = -1;
1002
1003         if (WARN_ON_ONCE(!msk))
1004                 return -1;
1005
1006         /* The 0 ID mapping is defined by the first subflow, copied into the msk
1007          * addr
1008          */
1009         local_address((struct sock_common *)msk, &msk_local);
1010         local_address((struct sock_common *)skc, &skc_local);
1011         if (addresses_equal(&msk_local, &skc_local, false))
1012                 return 0;
1013
1014         if (address_zero(&skc_local))
1015                 return 0;
1016
1017         pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id);
1018
1019         rcu_read_lock();
1020         list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) {
1021                 if (addresses_equal(&entry->addr, &skc_local, entry->addr.port)) {
1022                         ret = entry->addr.id;
1023                         break;
1024                 }
1025         }
1026         rcu_read_unlock();
1027         if (ret >= 0)
1028                 return ret;
1029
1030         /* address not found, add to local list */
1031         entry = kmalloc(sizeof(*entry), GFP_ATOMIC);
1032         if (!entry)
1033                 return -ENOMEM;
1034
1035         entry->addr = skc_local;
1036         entry->addr.id = 0;
1037         entry->addr.port = 0;
1038         entry->ifindex = 0;
1039         entry->flags = 0;
1040         entry->lsk = NULL;
1041         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1042         if (ret < 0)
1043                 kfree(entry);
1044
1045         return ret;
1046 }
1047
1048 void mptcp_pm_nl_data_init(struct mptcp_sock *msk)
1049 {
1050         struct mptcp_pm_data *pm = &msk->pm;
1051         bool subflows;
1052
1053         subflows = !!mptcp_pm_get_subflows_max(msk);
1054         WRITE_ONCE(pm->work_pending, (!!mptcp_pm_get_local_addr_max(msk) && subflows) ||
1055                    !!mptcp_pm_get_add_addr_signal_max(msk));
1056         WRITE_ONCE(pm->accept_addr, !!mptcp_pm_get_add_addr_accept_max(msk) && subflows);
1057         WRITE_ONCE(pm->accept_subflow, subflows);
1058 }
1059
1060 #define MPTCP_PM_CMD_GRP_OFFSET       0
1061 #define MPTCP_PM_EV_GRP_OFFSET        1
1062
1063 static const struct genl_multicast_group mptcp_pm_mcgrps[] = {
1064         [MPTCP_PM_CMD_GRP_OFFSET]       = { .name = MPTCP_PM_CMD_GRP_NAME, },
1065         [MPTCP_PM_EV_GRP_OFFSET]        = { .name = MPTCP_PM_EV_GRP_NAME,
1066                                             .flags = GENL_UNS_ADMIN_PERM,
1067                                           },
1068 };
1069
1070 static const struct nla_policy
1071 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = {
1072         [MPTCP_PM_ADDR_ATTR_FAMILY]     = { .type       = NLA_U16,      },
1073         [MPTCP_PM_ADDR_ATTR_ID]         = { .type       = NLA_U8,       },
1074         [MPTCP_PM_ADDR_ATTR_ADDR4]      = { .type       = NLA_U32,      },
1075         [MPTCP_PM_ADDR_ATTR_ADDR6]      =
1076                 NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)),
1077         [MPTCP_PM_ADDR_ATTR_PORT]       = { .type       = NLA_U16       },
1078         [MPTCP_PM_ADDR_ATTR_FLAGS]      = { .type       = NLA_U32       },
1079         [MPTCP_PM_ADDR_ATTR_IF_IDX]     = { .type       = NLA_S32       },
1080 };
1081
1082 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = {
1083         [MPTCP_PM_ATTR_ADDR]            =
1084                                         NLA_POLICY_NESTED(mptcp_pm_addr_policy),
1085         [MPTCP_PM_ATTR_RCV_ADD_ADDRS]   = { .type       = NLA_U32,      },
1086         [MPTCP_PM_ATTR_SUBFLOWS]        = { .type       = NLA_U32,      },
1087 };
1088
1089 void mptcp_pm_nl_subflow_chk_stale(const struct mptcp_sock *msk, struct sock *ssk)
1090 {
1091         struct mptcp_subflow_context *iter, *subflow = mptcp_subflow_ctx(ssk);
1092         struct sock *sk = (struct sock *)msk;
1093         unsigned int active_max_loss_cnt;
1094         struct net *net = sock_net(sk);
1095         unsigned int stale_loss_cnt;
1096         bool slow;
1097
1098         stale_loss_cnt = mptcp_stale_loss_cnt(net);
1099         if (subflow->stale || !stale_loss_cnt || subflow->stale_count <= stale_loss_cnt)
1100                 return;
1101
1102         /* look for another available subflow not in loss state */
1103         active_max_loss_cnt = max_t(int, stale_loss_cnt - 1, 1);
1104         mptcp_for_each_subflow(msk, iter) {
1105                 if (iter != subflow && mptcp_subflow_active(iter) &&
1106                     iter->stale_count < active_max_loss_cnt) {
1107                         /* we have some alternatives, try to mark this subflow as idle ...*/
1108                         slow = lock_sock_fast(ssk);
1109                         if (!tcp_rtx_and_write_queues_empty(ssk)) {
1110                                 subflow->stale = 1;
1111                                 __mptcp_retransmit_pending_data(sk);
1112                                 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_SUBFLOWSTALE);
1113                         }
1114                         unlock_sock_fast(ssk, slow);
1115
1116                         /* always try to push the pending data regarless of re-injections:
1117                          * we can possibly use backup subflows now, and subflow selection
1118                          * is cheap under the msk socket lock
1119                          */
1120                         __mptcp_push_pending(sk, 0);
1121                         return;
1122                 }
1123         }
1124 }
1125
1126 static int mptcp_pm_family_to_addr(int family)
1127 {
1128 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1129         if (family == AF_INET6)
1130                 return MPTCP_PM_ADDR_ATTR_ADDR6;
1131 #endif
1132         return MPTCP_PM_ADDR_ATTR_ADDR4;
1133 }
1134
1135 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info,
1136                                bool require_family,
1137                                struct mptcp_pm_addr_entry *entry)
1138 {
1139         struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1];
1140         int err, addr_addr;
1141
1142         if (!attr) {
1143                 GENL_SET_ERR_MSG(info, "missing address info");
1144                 return -EINVAL;
1145         }
1146
1147         /* no validation needed - was already done via nested policy */
1148         err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr,
1149                                           mptcp_pm_addr_policy, info->extack);
1150         if (err)
1151                 return err;
1152
1153         memset(entry, 0, sizeof(*entry));
1154         if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) {
1155                 if (!require_family)
1156                         goto skip_family;
1157
1158                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1159                                     "missing family");
1160                 return -EINVAL;
1161         }
1162
1163         entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]);
1164         if (entry->addr.family != AF_INET
1165 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1166             && entry->addr.family != AF_INET6
1167 #endif
1168             ) {
1169                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1170                                     "unknown address family");
1171                 return -EINVAL;
1172         }
1173         addr_addr = mptcp_pm_family_to_addr(entry->addr.family);
1174         if (!tb[addr_addr]) {
1175                 NL_SET_ERR_MSG_ATTR(info->extack, attr,
1176                                     "missing address data");
1177                 return -EINVAL;
1178         }
1179
1180 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1181         if (entry->addr.family == AF_INET6)
1182                 entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]);
1183         else
1184 #endif
1185                 entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]);
1186
1187 skip_family:
1188         if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) {
1189                 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]);
1190
1191                 entry->ifindex = val;
1192         }
1193
1194         if (tb[MPTCP_PM_ADDR_ATTR_ID])
1195                 entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]);
1196
1197         if (tb[MPTCP_PM_ADDR_ATTR_FLAGS])
1198                 entry->flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]);
1199
1200         if (tb[MPTCP_PM_ADDR_ATTR_PORT]) {
1201                 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) {
1202                         NL_SET_ERR_MSG_ATTR(info->extack, attr,
1203                                             "flags must have signal when using port");
1204                         return -EINVAL;
1205                 }
1206                 entry->addr.port = htons(nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_PORT]));
1207         }
1208
1209         return 0;
1210 }
1211
1212 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info)
1213 {
1214         return net_generic(genl_info_net(info), pm_nl_pernet_id);
1215 }
1216
1217 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net)
1218 {
1219         struct mptcp_sock *msk;
1220         long s_slot = 0, s_num = 0;
1221
1222         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1223                 struct sock *sk = (struct sock *)msk;
1224
1225                 if (!READ_ONCE(msk->fully_established))
1226                         goto next;
1227
1228                 lock_sock(sk);
1229                 spin_lock_bh(&msk->pm.lock);
1230                 mptcp_pm_create_subflow_or_signal_addr(msk);
1231                 spin_unlock_bh(&msk->pm.lock);
1232                 release_sock(sk);
1233
1234 next:
1235                 sock_put(sk);
1236                 cond_resched();
1237         }
1238
1239         return 0;
1240 }
1241
1242 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info)
1243 {
1244         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1245         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1246         struct mptcp_pm_addr_entry addr, *entry;
1247         int ret;
1248
1249         ret = mptcp_pm_parse_addr(attr, info, true, &addr);
1250         if (ret < 0)
1251                 return ret;
1252
1253         entry = kmalloc(sizeof(*entry), GFP_KERNEL);
1254         if (!entry) {
1255                 GENL_SET_ERR_MSG(info, "can't allocate addr");
1256                 return -ENOMEM;
1257         }
1258
1259         *entry = addr;
1260         if (entry->addr.port) {
1261                 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry);
1262                 if (ret) {
1263                         GENL_SET_ERR_MSG(info, "create listen socket error");
1264                         kfree(entry);
1265                         return ret;
1266                 }
1267         }
1268         ret = mptcp_pm_nl_append_new_local_addr(pernet, entry);
1269         if (ret < 0) {
1270                 GENL_SET_ERR_MSG(info, "too many addresses or duplicate one");
1271                 if (entry->lsk)
1272                         sock_release(entry->lsk);
1273                 kfree(entry);
1274                 return ret;
1275         }
1276
1277         mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk));
1278
1279         return 0;
1280 }
1281
1282 int mptcp_pm_get_flags_and_ifindex_by_id(struct net *net, unsigned int id,
1283                                          u8 *flags, int *ifindex)
1284 {
1285         struct mptcp_pm_addr_entry *entry;
1286
1287         *flags = 0;
1288         *ifindex = 0;
1289
1290         if (id) {
1291                 rcu_read_lock();
1292                 entry = __lookup_addr_by_id(net_generic(net, pm_nl_pernet_id), id);
1293                 if (entry) {
1294                         *flags = entry->flags;
1295                         *ifindex = entry->ifindex;
1296                 }
1297                 rcu_read_unlock();
1298         }
1299
1300         return 0;
1301 }
1302
1303 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk,
1304                                       struct mptcp_addr_info *addr)
1305 {
1306         struct mptcp_pm_add_entry *entry;
1307
1308         entry = mptcp_pm_del_add_timer(msk, addr, false);
1309         if (entry) {
1310                 list_del(&entry->list);
1311                 kfree(entry);
1312                 return true;
1313         }
1314
1315         return false;
1316 }
1317
1318 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk,
1319                                       struct mptcp_addr_info *addr,
1320                                       bool force)
1321 {
1322         struct mptcp_rm_list list = { .nr = 0 };
1323         bool ret;
1324
1325         list.ids[list.nr++] = addr->id;
1326
1327         ret = remove_anno_list_by_saddr(msk, addr);
1328         if (ret || force) {
1329                 spin_lock_bh(&msk->pm.lock);
1330                 mptcp_pm_remove_addr(msk, &list);
1331                 spin_unlock_bh(&msk->pm.lock);
1332         }
1333         return ret;
1334 }
1335
1336 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net,
1337                                                    struct mptcp_addr_info *addr)
1338 {
1339         struct mptcp_sock *msk;
1340         long s_slot = 0, s_num = 0;
1341         struct mptcp_rm_list list = { .nr = 0 };
1342
1343         pr_debug("remove_id=%d", addr->id);
1344
1345         list.ids[list.nr++] = addr->id;
1346
1347         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1348                 struct sock *sk = (struct sock *)msk;
1349                 bool remove_subflow;
1350
1351                 if (list_empty(&msk->conn_list)) {
1352                         mptcp_pm_remove_anno_addr(msk, addr, false);
1353                         goto next;
1354                 }
1355
1356                 lock_sock(sk);
1357                 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr);
1358                 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow);
1359                 if (remove_subflow)
1360                         mptcp_pm_remove_subflow(msk, &list);
1361                 release_sock(sk);
1362
1363 next:
1364                 sock_put(sk);
1365                 cond_resched();
1366         }
1367
1368         return 0;
1369 }
1370
1371 /* caller must ensure the RCU grace period is already elapsed */
1372 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry)
1373 {
1374         if (entry->lsk)
1375                 sock_release(entry->lsk);
1376         kfree(entry);
1377 }
1378
1379 static int mptcp_nl_remove_id_zero_address(struct net *net,
1380                                            struct mptcp_addr_info *addr)
1381 {
1382         struct mptcp_rm_list list = { .nr = 0 };
1383         long s_slot = 0, s_num = 0;
1384         struct mptcp_sock *msk;
1385
1386         list.ids[list.nr++] = 0;
1387
1388         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1389                 struct sock *sk = (struct sock *)msk;
1390                 struct mptcp_addr_info msk_local;
1391
1392                 if (list_empty(&msk->conn_list))
1393                         goto next;
1394
1395                 local_address((struct sock_common *)msk, &msk_local);
1396                 if (!addresses_equal(&msk_local, addr, addr->port))
1397                         goto next;
1398
1399                 lock_sock(sk);
1400                 spin_lock_bh(&msk->pm.lock);
1401                 mptcp_pm_remove_addr(msk, &list);
1402                 mptcp_pm_nl_rm_subflow_received(msk, &list);
1403                 spin_unlock_bh(&msk->pm.lock);
1404                 release_sock(sk);
1405
1406 next:
1407                 sock_put(sk);
1408                 cond_resched();
1409         }
1410
1411         return 0;
1412 }
1413
1414 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info)
1415 {
1416         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1417         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1418         struct mptcp_pm_addr_entry addr, *entry;
1419         unsigned int addr_max;
1420         int ret;
1421
1422         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1423         if (ret < 0)
1424                 return ret;
1425
1426         /* the zero id address is special: the first address used by the msk
1427          * always gets such an id, so different subflows can have different zero
1428          * id addresses. Additionally zero id is not accounted for in id_bitmap.
1429          * Let's use an 'mptcp_rm_list' instead of the common remove code.
1430          */
1431         if (addr.addr.id == 0)
1432                 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr);
1433
1434         spin_lock_bh(&pernet->lock);
1435         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1436         if (!entry) {
1437                 GENL_SET_ERR_MSG(info, "address not found");
1438                 spin_unlock_bh(&pernet->lock);
1439                 return -EINVAL;
1440         }
1441         if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) {
1442                 addr_max = pernet->add_addr_signal_max;
1443                 WRITE_ONCE(pernet->add_addr_signal_max, addr_max - 1);
1444         }
1445         if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) {
1446                 addr_max = pernet->local_addr_max;
1447                 WRITE_ONCE(pernet->local_addr_max, addr_max - 1);
1448         }
1449
1450         pernet->addrs--;
1451         list_del_rcu(&entry->list);
1452         __clear_bit(entry->addr.id, pernet->id_bitmap);
1453         spin_unlock_bh(&pernet->lock);
1454
1455         mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr);
1456         synchronize_rcu();
1457         __mptcp_pm_release_addr_entry(entry);
1458
1459         return ret;
1460 }
1461
1462 static void mptcp_pm_remove_addrs_and_subflows(struct mptcp_sock *msk,
1463                                                struct list_head *rm_list)
1464 {
1465         struct mptcp_rm_list alist = { .nr = 0 }, slist = { .nr = 0 };
1466         struct mptcp_pm_addr_entry *entry;
1467
1468         list_for_each_entry(entry, rm_list, list) {
1469                 if (lookup_subflow_by_saddr(&msk->conn_list, &entry->addr) &&
1470                     alist.nr < MPTCP_RM_IDS_MAX &&
1471                     slist.nr < MPTCP_RM_IDS_MAX) {
1472                         alist.ids[alist.nr++] = entry->addr.id;
1473                         slist.ids[slist.nr++] = entry->addr.id;
1474                 } else if (remove_anno_list_by_saddr(msk, &entry->addr) &&
1475                          alist.nr < MPTCP_RM_IDS_MAX) {
1476                         alist.ids[alist.nr++] = entry->addr.id;
1477                 }
1478         }
1479
1480         if (alist.nr) {
1481                 spin_lock_bh(&msk->pm.lock);
1482                 mptcp_pm_remove_addr(msk, &alist);
1483                 spin_unlock_bh(&msk->pm.lock);
1484         }
1485         if (slist.nr)
1486                 mptcp_pm_remove_subflow(msk, &slist);
1487 }
1488
1489 static void mptcp_nl_remove_addrs_list(struct net *net,
1490                                        struct list_head *rm_list)
1491 {
1492         long s_slot = 0, s_num = 0;
1493         struct mptcp_sock *msk;
1494
1495         if (list_empty(rm_list))
1496                 return;
1497
1498         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1499                 struct sock *sk = (struct sock *)msk;
1500
1501                 lock_sock(sk);
1502                 mptcp_pm_remove_addrs_and_subflows(msk, rm_list);
1503                 release_sock(sk);
1504
1505                 sock_put(sk);
1506                 cond_resched();
1507         }
1508 }
1509
1510 /* caller must ensure the RCU grace period is already elapsed */
1511 static void __flush_addrs(struct list_head *list)
1512 {
1513         while (!list_empty(list)) {
1514                 struct mptcp_pm_addr_entry *cur;
1515
1516                 cur = list_entry(list->next,
1517                                  struct mptcp_pm_addr_entry, list);
1518                 list_del_rcu(&cur->list);
1519                 __mptcp_pm_release_addr_entry(cur);
1520         }
1521 }
1522
1523 static void __reset_counters(struct pm_nl_pernet *pernet)
1524 {
1525         WRITE_ONCE(pernet->add_addr_signal_max, 0);
1526         WRITE_ONCE(pernet->add_addr_accept_max, 0);
1527         WRITE_ONCE(pernet->local_addr_max, 0);
1528         pernet->addrs = 0;
1529 }
1530
1531 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info)
1532 {
1533         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1534         LIST_HEAD(free_list);
1535
1536         spin_lock_bh(&pernet->lock);
1537         list_splice_init(&pernet->local_addr_list, &free_list);
1538         __reset_counters(pernet);
1539         pernet->next_id = 1;
1540         bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1);
1541         spin_unlock_bh(&pernet->lock);
1542         mptcp_nl_remove_addrs_list(sock_net(skb->sk), &free_list);
1543         synchronize_rcu();
1544         __flush_addrs(&free_list);
1545         return 0;
1546 }
1547
1548 static int mptcp_nl_fill_addr(struct sk_buff *skb,
1549                               struct mptcp_pm_addr_entry *entry)
1550 {
1551         struct mptcp_addr_info *addr = &entry->addr;
1552         struct nlattr *attr;
1553
1554         attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR);
1555         if (!attr)
1556                 return -EMSGSIZE;
1557
1558         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family))
1559                 goto nla_put_failure;
1560         if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_PORT, ntohs(addr->port)))
1561                 goto nla_put_failure;
1562         if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id))
1563                 goto nla_put_failure;
1564         if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->flags))
1565                 goto nla_put_failure;
1566         if (entry->ifindex &&
1567             nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->ifindex))
1568                 goto nla_put_failure;
1569
1570         if (addr->family == AF_INET &&
1571             nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4,
1572                             addr->addr.s_addr))
1573                 goto nla_put_failure;
1574 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1575         else if (addr->family == AF_INET6 &&
1576                  nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6))
1577                 goto nla_put_failure;
1578 #endif
1579         nla_nest_end(skb, attr);
1580         return 0;
1581
1582 nla_put_failure:
1583         nla_nest_cancel(skb, attr);
1584         return -EMSGSIZE;
1585 }
1586
1587 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info)
1588 {
1589         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1590         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1591         struct mptcp_pm_addr_entry addr, *entry;
1592         struct sk_buff *msg;
1593         void *reply;
1594         int ret;
1595
1596         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1597         if (ret < 0)
1598                 return ret;
1599
1600         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1601         if (!msg)
1602                 return -ENOMEM;
1603
1604         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1605                                   info->genlhdr->cmd);
1606         if (!reply) {
1607                 GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1608                 ret = -EMSGSIZE;
1609                 goto fail;
1610         }
1611
1612         spin_lock_bh(&pernet->lock);
1613         entry = __lookup_addr_by_id(pernet, addr.addr.id);
1614         if (!entry) {
1615                 GENL_SET_ERR_MSG(info, "address not found");
1616                 ret = -EINVAL;
1617                 goto unlock_fail;
1618         }
1619
1620         ret = mptcp_nl_fill_addr(msg, entry);
1621         if (ret)
1622                 goto unlock_fail;
1623
1624         genlmsg_end(msg, reply);
1625         ret = genlmsg_reply(msg, info);
1626         spin_unlock_bh(&pernet->lock);
1627         return ret;
1628
1629 unlock_fail:
1630         spin_unlock_bh(&pernet->lock);
1631
1632 fail:
1633         nlmsg_free(msg);
1634         return ret;
1635 }
1636
1637 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg,
1638                                    struct netlink_callback *cb)
1639 {
1640         struct net *net = sock_net(msg->sk);
1641         struct mptcp_pm_addr_entry *entry;
1642         struct pm_nl_pernet *pernet;
1643         int id = cb->args[0];
1644         void *hdr;
1645         int i;
1646
1647         pernet = net_generic(net, pm_nl_pernet_id);
1648
1649         spin_lock_bh(&pernet->lock);
1650         for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) {
1651                 if (test_bit(i, pernet->id_bitmap)) {
1652                         entry = __lookup_addr_by_id(pernet, i);
1653                         if (!entry)
1654                                 break;
1655
1656                         if (entry->addr.id <= id)
1657                                 continue;
1658
1659                         hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid,
1660                                           cb->nlh->nlmsg_seq, &mptcp_genl_family,
1661                                           NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR);
1662                         if (!hdr)
1663                                 break;
1664
1665                         if (mptcp_nl_fill_addr(msg, entry) < 0) {
1666                                 genlmsg_cancel(msg, hdr);
1667                                 break;
1668                         }
1669
1670                         id = entry->addr.id;
1671                         genlmsg_end(msg, hdr);
1672                 }
1673         }
1674         spin_unlock_bh(&pernet->lock);
1675
1676         cb->args[0] = id;
1677         return msg->len;
1678 }
1679
1680 static int parse_limit(struct genl_info *info, int id, unsigned int *limit)
1681 {
1682         struct nlattr *attr = info->attrs[id];
1683
1684         if (!attr)
1685                 return 0;
1686
1687         *limit = nla_get_u32(attr);
1688         if (*limit > MPTCP_PM_ADDR_MAX) {
1689                 GENL_SET_ERR_MSG(info, "limit greater than maximum");
1690                 return -EINVAL;
1691         }
1692         return 0;
1693 }
1694
1695 static int
1696 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info)
1697 {
1698         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1699         unsigned int rcv_addrs, subflows;
1700         int ret;
1701
1702         spin_lock_bh(&pernet->lock);
1703         rcv_addrs = pernet->add_addr_accept_max;
1704         ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs);
1705         if (ret)
1706                 goto unlock;
1707
1708         subflows = pernet->subflows_max;
1709         ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows);
1710         if (ret)
1711                 goto unlock;
1712
1713         WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs);
1714         WRITE_ONCE(pernet->subflows_max, subflows);
1715
1716 unlock:
1717         spin_unlock_bh(&pernet->lock);
1718         return ret;
1719 }
1720
1721 static int
1722 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info)
1723 {
1724         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1725         struct sk_buff *msg;
1726         void *reply;
1727
1728         msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
1729         if (!msg)
1730                 return -ENOMEM;
1731
1732         reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0,
1733                                   MPTCP_PM_CMD_GET_LIMITS);
1734         if (!reply)
1735                 goto fail;
1736
1737         if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS,
1738                         READ_ONCE(pernet->add_addr_accept_max)))
1739                 goto fail;
1740
1741         if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS,
1742                         READ_ONCE(pernet->subflows_max)))
1743                 goto fail;
1744
1745         genlmsg_end(msg, reply);
1746         return genlmsg_reply(msg, info);
1747
1748 fail:
1749         GENL_SET_ERR_MSG(info, "not enough space in Netlink message");
1750         nlmsg_free(msg);
1751         return -EMSGSIZE;
1752 }
1753
1754 static int mptcp_nl_addr_backup(struct net *net,
1755                                 struct mptcp_addr_info *addr,
1756                                 u8 bkup)
1757 {
1758         long s_slot = 0, s_num = 0;
1759         struct mptcp_sock *msk;
1760         int ret = -EINVAL;
1761
1762         while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) {
1763                 struct sock *sk = (struct sock *)msk;
1764
1765                 if (list_empty(&msk->conn_list))
1766                         goto next;
1767
1768                 lock_sock(sk);
1769                 spin_lock_bh(&msk->pm.lock);
1770                 ret = mptcp_pm_nl_mp_prio_send_ack(msk, addr, bkup);
1771                 spin_unlock_bh(&msk->pm.lock);
1772                 release_sock(sk);
1773
1774 next:
1775                 sock_put(sk);
1776                 cond_resched();
1777         }
1778
1779         return ret;
1780 }
1781
1782 static int mptcp_nl_cmd_set_flags(struct sk_buff *skb, struct genl_info *info)
1783 {
1784         struct mptcp_pm_addr_entry addr = { .addr = { .family = AF_UNSPEC }, }, *entry;
1785         struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR];
1786         struct pm_nl_pernet *pernet = genl_info_pm_nl(info);
1787         struct net *net = sock_net(skb->sk);
1788         u8 bkup = 0, lookup_by_id = 0;
1789         int ret;
1790
1791         ret = mptcp_pm_parse_addr(attr, info, false, &addr);
1792         if (ret < 0)
1793                 return ret;
1794
1795         if (addr.flags & MPTCP_PM_ADDR_FLAG_BACKUP)
1796                 bkup = 1;
1797         if (addr.addr.family == AF_UNSPEC) {
1798                 lookup_by_id = 1;
1799                 if (!addr.addr.id)
1800                         return -EOPNOTSUPP;
1801         }
1802
1803         spin_lock_bh(&pernet->lock);
1804         entry = __lookup_addr(pernet, &addr.addr, lookup_by_id);
1805         if (!entry) {
1806                 spin_unlock_bh(&pernet->lock);
1807                 return -EINVAL;
1808         }
1809
1810         if (bkup)
1811                 entry->flags |= MPTCP_PM_ADDR_FLAG_BACKUP;
1812         else
1813                 entry->flags &= ~MPTCP_PM_ADDR_FLAG_BACKUP;
1814         addr = *entry;
1815         spin_unlock_bh(&pernet->lock);
1816
1817         mptcp_nl_addr_backup(net, &addr.addr, bkup);
1818         return 0;
1819 }
1820
1821 static void mptcp_nl_mcast_send(struct net *net, struct sk_buff *nlskb, gfp_t gfp)
1822 {
1823         genlmsg_multicast_netns(&mptcp_genl_family, net,
1824                                 nlskb, 0, MPTCP_PM_EV_GRP_OFFSET, gfp);
1825 }
1826
1827 static int mptcp_event_add_subflow(struct sk_buff *skb, const struct sock *ssk)
1828 {
1829         const struct inet_sock *issk = inet_sk(ssk);
1830         const struct mptcp_subflow_context *sf;
1831
1832         if (nla_put_u16(skb, MPTCP_ATTR_FAMILY, ssk->sk_family))
1833                 return -EMSGSIZE;
1834
1835         switch (ssk->sk_family) {
1836         case AF_INET:
1837                 if (nla_put_in_addr(skb, MPTCP_ATTR_SADDR4, issk->inet_saddr))
1838                         return -EMSGSIZE;
1839                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, issk->inet_daddr))
1840                         return -EMSGSIZE;
1841                 break;
1842 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
1843         case AF_INET6: {
1844                 const struct ipv6_pinfo *np = inet6_sk(ssk);
1845
1846                 if (nla_put_in6_addr(skb, MPTCP_ATTR_SADDR6, &np->saddr))
1847                         return -EMSGSIZE;
1848                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &ssk->sk_v6_daddr))
1849                         return -EMSGSIZE;
1850                 break;
1851         }
1852 #endif
1853         default:
1854                 WARN_ON_ONCE(1);
1855                 return -EMSGSIZE;
1856         }
1857
1858         if (nla_put_be16(skb, MPTCP_ATTR_SPORT, issk->inet_sport))
1859                 return -EMSGSIZE;
1860         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, issk->inet_dport))
1861                 return -EMSGSIZE;
1862
1863         sf = mptcp_subflow_ctx(ssk);
1864         if (WARN_ON_ONCE(!sf))
1865                 return -EINVAL;
1866
1867         if (nla_put_u8(skb, MPTCP_ATTR_LOC_ID, sf->local_id))
1868                 return -EMSGSIZE;
1869
1870         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, sf->remote_id))
1871                 return -EMSGSIZE;
1872
1873         return 0;
1874 }
1875
1876 static int mptcp_event_put_token_and_ssk(struct sk_buff *skb,
1877                                          const struct mptcp_sock *msk,
1878                                          const struct sock *ssk)
1879 {
1880         const struct sock *sk = (const struct sock *)msk;
1881         const struct mptcp_subflow_context *sf;
1882         u8 sk_err;
1883
1884         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1885                 return -EMSGSIZE;
1886
1887         if (mptcp_event_add_subflow(skb, ssk))
1888                 return -EMSGSIZE;
1889
1890         sf = mptcp_subflow_ctx(ssk);
1891         if (WARN_ON_ONCE(!sf))
1892                 return -EINVAL;
1893
1894         if (nla_put_u8(skb, MPTCP_ATTR_BACKUP, sf->backup))
1895                 return -EMSGSIZE;
1896
1897         if (ssk->sk_bound_dev_if &&
1898             nla_put_s32(skb, MPTCP_ATTR_IF_IDX, ssk->sk_bound_dev_if))
1899                 return -EMSGSIZE;
1900
1901         sk_err = ssk->sk_err;
1902         if (sk_err && sk->sk_state == TCP_ESTABLISHED &&
1903             nla_put_u8(skb, MPTCP_ATTR_ERROR, sk_err))
1904                 return -EMSGSIZE;
1905
1906         return 0;
1907 }
1908
1909 static int mptcp_event_sub_established(struct sk_buff *skb,
1910                                        const struct mptcp_sock *msk,
1911                                        const struct sock *ssk)
1912 {
1913         return mptcp_event_put_token_and_ssk(skb, msk, ssk);
1914 }
1915
1916 static int mptcp_event_sub_closed(struct sk_buff *skb,
1917                                   const struct mptcp_sock *msk,
1918                                   const struct sock *ssk)
1919 {
1920         const struct mptcp_subflow_context *sf;
1921
1922         if (mptcp_event_put_token_and_ssk(skb, msk, ssk))
1923                 return -EMSGSIZE;
1924
1925         sf = mptcp_subflow_ctx(ssk);
1926         if (!sf->reset_seen)
1927                 return 0;
1928
1929         if (nla_put_u32(skb, MPTCP_ATTR_RESET_REASON, sf->reset_reason))
1930                 return -EMSGSIZE;
1931
1932         if (nla_put_u32(skb, MPTCP_ATTR_RESET_FLAGS, sf->reset_transient))
1933                 return -EMSGSIZE;
1934
1935         return 0;
1936 }
1937
1938 static int mptcp_event_created(struct sk_buff *skb,
1939                                const struct mptcp_sock *msk,
1940                                const struct sock *ssk)
1941 {
1942         int err = nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token);
1943
1944         if (err)
1945                 return err;
1946
1947         return mptcp_event_add_subflow(skb, ssk);
1948 }
1949
1950 void mptcp_event_addr_removed(const struct mptcp_sock *msk, uint8_t id)
1951 {
1952         struct net *net = sock_net((const struct sock *)msk);
1953         struct nlmsghdr *nlh;
1954         struct sk_buff *skb;
1955
1956         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1957                 return;
1958
1959         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1960         if (!skb)
1961                 return;
1962
1963         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, MPTCP_EVENT_REMOVED);
1964         if (!nlh)
1965                 goto nla_put_failure;
1966
1967         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
1968                 goto nla_put_failure;
1969
1970         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, id))
1971                 goto nla_put_failure;
1972
1973         genlmsg_end(skb, nlh);
1974         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
1975         return;
1976
1977 nla_put_failure:
1978         kfree_skb(skb);
1979 }
1980
1981 void mptcp_event_addr_announced(const struct mptcp_sock *msk,
1982                                 const struct mptcp_addr_info *info)
1983 {
1984         struct net *net = sock_net((const struct sock *)msk);
1985         struct nlmsghdr *nlh;
1986         struct sk_buff *skb;
1987
1988         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
1989                 return;
1990
1991         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
1992         if (!skb)
1993                 return;
1994
1995         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0,
1996                           MPTCP_EVENT_ANNOUNCED);
1997         if (!nlh)
1998                 goto nla_put_failure;
1999
2000         if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token))
2001                 goto nla_put_failure;
2002
2003         if (nla_put_u8(skb, MPTCP_ATTR_REM_ID, info->id))
2004                 goto nla_put_failure;
2005
2006         if (nla_put_be16(skb, MPTCP_ATTR_DPORT, info->port))
2007                 goto nla_put_failure;
2008
2009         switch (info->family) {
2010         case AF_INET:
2011                 if (nla_put_in_addr(skb, MPTCP_ATTR_DADDR4, info->addr.s_addr))
2012                         goto nla_put_failure;
2013                 break;
2014 #if IS_ENABLED(CONFIG_MPTCP_IPV6)
2015         case AF_INET6:
2016                 if (nla_put_in6_addr(skb, MPTCP_ATTR_DADDR6, &info->addr6))
2017                         goto nla_put_failure;
2018                 break;
2019 #endif
2020         default:
2021                 WARN_ON_ONCE(1);
2022                 goto nla_put_failure;
2023         }
2024
2025         genlmsg_end(skb, nlh);
2026         mptcp_nl_mcast_send(net, skb, GFP_ATOMIC);
2027         return;
2028
2029 nla_put_failure:
2030         kfree_skb(skb);
2031 }
2032
2033 void mptcp_event(enum mptcp_event_type type, const struct mptcp_sock *msk,
2034                  const struct sock *ssk, gfp_t gfp)
2035 {
2036         struct net *net = sock_net((const struct sock *)msk);
2037         struct nlmsghdr *nlh;
2038         struct sk_buff *skb;
2039
2040         if (!genl_has_listeners(&mptcp_genl_family, net, MPTCP_PM_EV_GRP_OFFSET))
2041                 return;
2042
2043         skb = nlmsg_new(NLMSG_DEFAULT_SIZE, gfp);
2044         if (!skb)
2045                 return;
2046
2047         nlh = genlmsg_put(skb, 0, 0, &mptcp_genl_family, 0, type);
2048         if (!nlh)
2049                 goto nla_put_failure;
2050
2051         switch (type) {
2052         case MPTCP_EVENT_UNSPEC:
2053                 WARN_ON_ONCE(1);
2054                 break;
2055         case MPTCP_EVENT_CREATED:
2056         case MPTCP_EVENT_ESTABLISHED:
2057                 if (mptcp_event_created(skb, msk, ssk) < 0)
2058                         goto nla_put_failure;
2059                 break;
2060         case MPTCP_EVENT_CLOSED:
2061                 if (nla_put_u32(skb, MPTCP_ATTR_TOKEN, msk->token) < 0)
2062                         goto nla_put_failure;
2063                 break;
2064         case MPTCP_EVENT_ANNOUNCED:
2065         case MPTCP_EVENT_REMOVED:
2066                 /* call mptcp_event_addr_announced()/removed instead */
2067                 WARN_ON_ONCE(1);
2068                 break;
2069         case MPTCP_EVENT_SUB_ESTABLISHED:
2070         case MPTCP_EVENT_SUB_PRIORITY:
2071                 if (mptcp_event_sub_established(skb, msk, ssk) < 0)
2072                         goto nla_put_failure;
2073                 break;
2074         case MPTCP_EVENT_SUB_CLOSED:
2075                 if (mptcp_event_sub_closed(skb, msk, ssk) < 0)
2076                         goto nla_put_failure;
2077                 break;
2078         }
2079
2080         genlmsg_end(skb, nlh);
2081         mptcp_nl_mcast_send(net, skb, gfp);
2082         return;
2083
2084 nla_put_failure:
2085         kfree_skb(skb);
2086 }
2087
2088 static const struct genl_small_ops mptcp_pm_ops[] = {
2089         {
2090                 .cmd    = MPTCP_PM_CMD_ADD_ADDR,
2091                 .doit   = mptcp_nl_cmd_add_addr,
2092                 .flags  = GENL_ADMIN_PERM,
2093         },
2094         {
2095                 .cmd    = MPTCP_PM_CMD_DEL_ADDR,
2096                 .doit   = mptcp_nl_cmd_del_addr,
2097                 .flags  = GENL_ADMIN_PERM,
2098         },
2099         {
2100                 .cmd    = MPTCP_PM_CMD_FLUSH_ADDRS,
2101                 .doit   = mptcp_nl_cmd_flush_addrs,
2102                 .flags  = GENL_ADMIN_PERM,
2103         },
2104         {
2105                 .cmd    = MPTCP_PM_CMD_GET_ADDR,
2106                 .doit   = mptcp_nl_cmd_get_addr,
2107                 .dumpit   = mptcp_nl_cmd_dump_addrs,
2108         },
2109         {
2110                 .cmd    = MPTCP_PM_CMD_SET_LIMITS,
2111                 .doit   = mptcp_nl_cmd_set_limits,
2112                 .flags  = GENL_ADMIN_PERM,
2113         },
2114         {
2115                 .cmd    = MPTCP_PM_CMD_GET_LIMITS,
2116                 .doit   = mptcp_nl_cmd_get_limits,
2117         },
2118         {
2119                 .cmd    = MPTCP_PM_CMD_SET_FLAGS,
2120                 .doit   = mptcp_nl_cmd_set_flags,
2121                 .flags  = GENL_ADMIN_PERM,
2122         },
2123 };
2124
2125 static struct genl_family mptcp_genl_family __ro_after_init = {
2126         .name           = MPTCP_PM_NAME,
2127         .version        = MPTCP_PM_VER,
2128         .maxattr        = MPTCP_PM_ATTR_MAX,
2129         .policy         = mptcp_pm_policy,
2130         .netnsok        = true,
2131         .module         = THIS_MODULE,
2132         .small_ops      = mptcp_pm_ops,
2133         .n_small_ops    = ARRAY_SIZE(mptcp_pm_ops),
2134         .mcgrps         = mptcp_pm_mcgrps,
2135         .n_mcgrps       = ARRAY_SIZE(mptcp_pm_mcgrps),
2136 };
2137
2138 static int __net_init pm_nl_init_net(struct net *net)
2139 {
2140         struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
2141
2142         INIT_LIST_HEAD_RCU(&pernet->local_addr_list);
2143
2144         /* Cit. 2 subflows ought to be enough for anybody. */
2145         pernet->subflows_max = 2;
2146         pernet->next_id = 1;
2147         pernet->stale_loss_cnt = 4;
2148         spin_lock_init(&pernet->lock);
2149
2150         /* No need to initialize other pernet fields, the struct is zeroed at
2151          * allocation time.
2152          */
2153
2154         return 0;
2155 }
2156
2157 static void __net_exit pm_nl_exit_net(struct list_head *net_list)
2158 {
2159         struct net *net;
2160
2161         list_for_each_entry(net, net_list, exit_list) {
2162                 struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id);
2163
2164                 /* net is removed from namespace list, can't race with
2165                  * other modifiers, also netns core already waited for a
2166                  * RCU grace period.
2167                  */
2168                 __flush_addrs(&pernet->local_addr_list);
2169         }
2170 }
2171
2172 static struct pernet_operations mptcp_pm_pernet_ops = {
2173         .init = pm_nl_init_net,
2174         .exit_batch = pm_nl_exit_net,
2175         .id = &pm_nl_pernet_id,
2176         .size = sizeof(struct pm_nl_pernet),
2177 };
2178
2179 void __init mptcp_pm_nl_init(void)
2180 {
2181         if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0)
2182                 panic("Failed to register MPTCP PM pernet subsystem.\n");
2183
2184         if (genl_register_family(&mptcp_genl_family))
2185                 panic("Failed to register MPTCP PM netlink family\n");
2186 }