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