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 struct rcu_head rcu; 29 }; 30 31 struct mptcp_pm_add_entry { 32 struct list_head list; 33 struct mptcp_addr_info addr; 34 struct timer_list add_timer; 35 struct mptcp_sock *sock; 36 u8 retrans_times; 37 }; 38 39 struct pm_nl_pernet { 40 /* protects pernet updates */ 41 spinlock_t lock; 42 struct list_head local_addr_list; 43 unsigned int addrs; 44 unsigned int add_addr_signal_max; 45 unsigned int add_addr_accept_max; 46 unsigned int local_addr_max; 47 unsigned int subflows_max; 48 unsigned int next_id; 49 }; 50 51 #define MPTCP_PM_ADDR_MAX 8 52 #define ADD_ADDR_RETRANS_MAX 3 53 54 static bool addresses_equal(const struct mptcp_addr_info *a, 55 struct mptcp_addr_info *b, bool use_port) 56 { 57 bool addr_equals = false; 58 59 if (a->family != b->family) 60 return false; 61 62 if (a->family == AF_INET) 63 addr_equals = a->addr.s_addr == b->addr.s_addr; 64 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 65 else 66 addr_equals = !ipv6_addr_cmp(&a->addr6, &b->addr6); 67 #endif 68 69 if (!addr_equals) 70 return false; 71 if (!use_port) 72 return true; 73 74 return a->port == b->port; 75 } 76 77 static bool address_zero(const struct mptcp_addr_info *addr) 78 { 79 struct mptcp_addr_info zero; 80 81 memset(&zero, 0, sizeof(zero)); 82 zero.family = addr->family; 83 84 return addresses_equal(addr, &zero, false); 85 } 86 87 static void local_address(const struct sock_common *skc, 88 struct mptcp_addr_info *addr) 89 { 90 addr->port = 0; 91 addr->family = skc->skc_family; 92 if (addr->family == AF_INET) 93 addr->addr.s_addr = skc->skc_rcv_saddr; 94 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 95 else if (addr->family == AF_INET6) 96 addr->addr6 = skc->skc_v6_rcv_saddr; 97 #endif 98 } 99 100 static void remote_address(const struct sock_common *skc, 101 struct mptcp_addr_info *addr) 102 { 103 addr->family = skc->skc_family; 104 addr->port = skc->skc_dport; 105 if (addr->family == AF_INET) 106 addr->addr.s_addr = skc->skc_daddr; 107 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 108 else if (addr->family == AF_INET6) 109 addr->addr6 = skc->skc_v6_daddr; 110 #endif 111 } 112 113 static bool lookup_subflow_by_saddr(const struct list_head *list, 114 struct mptcp_addr_info *saddr) 115 { 116 struct mptcp_subflow_context *subflow; 117 struct mptcp_addr_info cur; 118 struct sock_common *skc; 119 120 list_for_each_entry(subflow, list, node) { 121 skc = (struct sock_common *)mptcp_subflow_tcp_sock(subflow); 122 123 local_address(skc, &cur); 124 if (addresses_equal(&cur, saddr, false)) 125 return true; 126 } 127 128 return false; 129 } 130 131 static struct mptcp_pm_addr_entry * 132 select_local_address(const struct pm_nl_pernet *pernet, 133 struct mptcp_sock *msk) 134 { 135 struct mptcp_pm_addr_entry *entry, *ret = NULL; 136 137 rcu_read_lock(); 138 __mptcp_flush_join_list(msk); 139 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { 140 if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)) 141 continue; 142 143 /* avoid any address already in use by subflows and 144 * pending join 145 */ 146 if (entry->addr.family == ((struct sock *)msk)->sk_family && 147 !lookup_subflow_by_saddr(&msk->conn_list, &entry->addr)) { 148 ret = entry; 149 break; 150 } 151 } 152 rcu_read_unlock(); 153 return ret; 154 } 155 156 static struct mptcp_pm_addr_entry * 157 select_signal_address(struct pm_nl_pernet *pernet, unsigned int pos) 158 { 159 struct mptcp_pm_addr_entry *entry, *ret = NULL; 160 int i = 0; 161 162 rcu_read_lock(); 163 /* do not keep any additional per socket state, just signal 164 * the address list in order. 165 * Note: removal from the local address list during the msk life-cycle 166 * can lead to additional addresses not being announced. 167 */ 168 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { 169 if (!(entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) 170 continue; 171 if (i++ == pos) { 172 ret = entry; 173 break; 174 } 175 } 176 rcu_read_unlock(); 177 return ret; 178 } 179 180 static void check_work_pending(struct mptcp_sock *msk) 181 { 182 if (msk->pm.add_addr_signaled == msk->pm.add_addr_signal_max && 183 (msk->pm.local_addr_used == msk->pm.local_addr_max || 184 msk->pm.subflows == msk->pm.subflows_max)) 185 WRITE_ONCE(msk->pm.work_pending, false); 186 } 187 188 static struct mptcp_pm_add_entry * 189 lookup_anno_list_by_saddr(struct mptcp_sock *msk, 190 struct mptcp_addr_info *addr) 191 { 192 struct mptcp_pm_add_entry *entry; 193 194 list_for_each_entry(entry, &msk->pm.anno_list, list) { 195 if (addresses_equal(&entry->addr, addr, false)) 196 return entry; 197 } 198 199 return NULL; 200 } 201 202 static void mptcp_pm_add_timer(struct timer_list *timer) 203 { 204 struct mptcp_pm_add_entry *entry = from_timer(entry, timer, add_timer); 205 struct mptcp_sock *msk = entry->sock; 206 struct sock *sk = (struct sock *)msk; 207 208 pr_debug("msk=%p", msk); 209 210 if (!msk) 211 return; 212 213 if (inet_sk_state_load(sk) == TCP_CLOSE) 214 return; 215 216 if (!entry->addr.id) 217 return; 218 219 if (mptcp_pm_should_add_signal(msk)) { 220 sk_reset_timer(sk, timer, jiffies + TCP_RTO_MAX / 8); 221 goto out; 222 } 223 224 spin_lock_bh(&msk->pm.lock); 225 226 if (!mptcp_pm_should_add_signal(msk)) { 227 pr_debug("retransmit ADD_ADDR id=%d", entry->addr.id); 228 mptcp_pm_announce_addr(msk, &entry->addr, false, entry->addr.port); 229 mptcp_pm_add_addr_send_ack(msk); 230 entry->retrans_times++; 231 } 232 233 if (entry->retrans_times < ADD_ADDR_RETRANS_MAX) 234 sk_reset_timer(sk, timer, 235 jiffies + mptcp_get_add_addr_timeout(sock_net(sk))); 236 237 spin_unlock_bh(&msk->pm.lock); 238 239 out: 240 __sock_put(sk); 241 } 242 243 struct mptcp_pm_add_entry * 244 mptcp_pm_del_add_timer(struct mptcp_sock *msk, 245 struct mptcp_addr_info *addr) 246 { 247 struct mptcp_pm_add_entry *entry; 248 struct sock *sk = (struct sock *)msk; 249 250 spin_lock_bh(&msk->pm.lock); 251 entry = lookup_anno_list_by_saddr(msk, addr); 252 if (entry) 253 entry->retrans_times = ADD_ADDR_RETRANS_MAX; 254 spin_unlock_bh(&msk->pm.lock); 255 256 if (entry) 257 sk_stop_timer_sync(sk, &entry->add_timer); 258 259 return entry; 260 } 261 262 static bool mptcp_pm_alloc_anno_list(struct mptcp_sock *msk, 263 struct mptcp_pm_addr_entry *entry) 264 { 265 struct mptcp_pm_add_entry *add_entry = NULL; 266 struct sock *sk = (struct sock *)msk; 267 struct net *net = sock_net(sk); 268 269 if (lookup_anno_list_by_saddr(msk, &entry->addr)) 270 return false; 271 272 add_entry = kmalloc(sizeof(*add_entry), GFP_ATOMIC); 273 if (!add_entry) 274 return false; 275 276 list_add(&add_entry->list, &msk->pm.anno_list); 277 278 add_entry->addr = entry->addr; 279 add_entry->sock = msk; 280 add_entry->retrans_times = 0; 281 282 timer_setup(&add_entry->add_timer, mptcp_pm_add_timer, 0); 283 sk_reset_timer(sk, &add_entry->add_timer, 284 jiffies + mptcp_get_add_addr_timeout(net)); 285 286 return true; 287 } 288 289 void mptcp_pm_free_anno_list(struct mptcp_sock *msk) 290 { 291 struct mptcp_pm_add_entry *entry, *tmp; 292 struct sock *sk = (struct sock *)msk; 293 LIST_HEAD(free_list); 294 295 pr_debug("msk=%p", msk); 296 297 spin_lock_bh(&msk->pm.lock); 298 list_splice_init(&msk->pm.anno_list, &free_list); 299 spin_unlock_bh(&msk->pm.lock); 300 301 list_for_each_entry_safe(entry, tmp, &free_list, list) { 302 sk_stop_timer_sync(sk, &entry->add_timer); 303 kfree(entry); 304 } 305 } 306 307 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) 308 { 309 struct mptcp_addr_info remote = { 0 }; 310 struct sock *sk = (struct sock *)msk; 311 struct mptcp_pm_addr_entry *local; 312 struct pm_nl_pernet *pernet; 313 314 pernet = net_generic(sock_net(sk), pm_nl_pernet_id); 315 316 pr_debug("local %d:%d signal %d:%d subflows %d:%d\n", 317 msk->pm.local_addr_used, msk->pm.local_addr_max, 318 msk->pm.add_addr_signaled, msk->pm.add_addr_signal_max, 319 msk->pm.subflows, msk->pm.subflows_max); 320 321 /* check first for announce */ 322 if (msk->pm.add_addr_signaled < msk->pm.add_addr_signal_max) { 323 local = select_signal_address(pernet, 324 msk->pm.add_addr_signaled); 325 326 if (local) { 327 if (mptcp_pm_alloc_anno_list(msk, local)) { 328 msk->pm.add_addr_signaled++; 329 mptcp_pm_announce_addr(msk, &local->addr, false, local->addr.port); 330 mptcp_pm_nl_add_addr_send_ack(msk); 331 } 332 } else { 333 /* pick failed, avoid fourther attempts later */ 334 msk->pm.local_addr_used = msk->pm.add_addr_signal_max; 335 } 336 337 check_work_pending(msk); 338 } 339 340 /* check if should create a new subflow */ 341 if (msk->pm.local_addr_used < msk->pm.local_addr_max && 342 msk->pm.subflows < msk->pm.subflows_max) { 343 remote_address((struct sock_common *)sk, &remote); 344 345 local = select_local_address(pernet, msk); 346 if (local) { 347 msk->pm.local_addr_used++; 348 msk->pm.subflows++; 349 check_work_pending(msk); 350 spin_unlock_bh(&msk->pm.lock); 351 __mptcp_subflow_connect(sk, &local->addr, &remote); 352 spin_lock_bh(&msk->pm.lock); 353 return; 354 } 355 356 /* lookup failed, avoid fourther attempts later */ 357 msk->pm.local_addr_used = msk->pm.local_addr_max; 358 check_work_pending(msk); 359 } 360 } 361 362 void mptcp_pm_nl_fully_established(struct mptcp_sock *msk) 363 { 364 mptcp_pm_create_subflow_or_signal_addr(msk); 365 } 366 367 void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk) 368 { 369 mptcp_pm_create_subflow_or_signal_addr(msk); 370 } 371 372 void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) 373 { 374 struct sock *sk = (struct sock *)msk; 375 struct mptcp_addr_info remote; 376 struct mptcp_addr_info local; 377 bool use_port = false; 378 379 pr_debug("accepted %d:%d remote family %d", 380 msk->pm.add_addr_accepted, msk->pm.add_addr_accept_max, 381 msk->pm.remote.family); 382 msk->pm.add_addr_accepted++; 383 msk->pm.subflows++; 384 if (msk->pm.add_addr_accepted >= msk->pm.add_addr_accept_max || 385 msk->pm.subflows >= msk->pm.subflows_max) 386 WRITE_ONCE(msk->pm.accept_addr, false); 387 388 /* connect to the specified remote address, using whatever 389 * local address the routing configuration will pick. 390 */ 391 remote = msk->pm.remote; 392 if (!remote.port) 393 remote.port = sk->sk_dport; 394 else 395 use_port = true; 396 memset(&local, 0, sizeof(local)); 397 local.family = remote.family; 398 399 spin_unlock_bh(&msk->pm.lock); 400 __mptcp_subflow_connect(sk, &local, &remote); 401 spin_lock_bh(&msk->pm.lock); 402 403 mptcp_pm_announce_addr(msk, &remote, true, use_port); 404 mptcp_pm_nl_add_addr_send_ack(msk); 405 } 406 407 void mptcp_pm_nl_add_addr_send_ack(struct mptcp_sock *msk) 408 { 409 struct mptcp_subflow_context *subflow; 410 411 if (!mptcp_pm_should_add_signal_ipv6(msk) && 412 !mptcp_pm_should_add_signal_port(msk)) 413 return; 414 415 __mptcp_flush_join_list(msk); 416 subflow = list_first_entry_or_null(&msk->conn_list, typeof(*subflow), node); 417 if (subflow) { 418 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 419 u8 add_addr; 420 421 spin_unlock_bh(&msk->pm.lock); 422 if (mptcp_pm_should_add_signal_ipv6(msk)) 423 pr_debug("send ack for add_addr6"); 424 if (mptcp_pm_should_add_signal_port(msk)) 425 pr_debug("send ack for add_addr_port"); 426 427 lock_sock(ssk); 428 tcp_send_ack(ssk); 429 release_sock(ssk); 430 spin_lock_bh(&msk->pm.lock); 431 432 add_addr = READ_ONCE(msk->pm.addr_signal); 433 if (mptcp_pm_should_add_signal_ipv6(msk)) 434 add_addr &= ~BIT(MPTCP_ADD_ADDR_IPV6); 435 if (mptcp_pm_should_add_signal_port(msk)) 436 add_addr &= ~BIT(MPTCP_ADD_ADDR_PORT); 437 WRITE_ONCE(msk->pm.addr_signal, add_addr); 438 } 439 } 440 441 void mptcp_pm_nl_rm_addr_received(struct mptcp_sock *msk) 442 { 443 struct mptcp_subflow_context *subflow, *tmp; 444 struct sock *sk = (struct sock *)msk; 445 446 pr_debug("address rm_id %d", msk->pm.rm_id); 447 448 if (!msk->pm.rm_id) 449 return; 450 451 if (list_empty(&msk->conn_list)) 452 return; 453 454 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { 455 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 456 int how = RCV_SHUTDOWN | SEND_SHUTDOWN; 457 458 if (msk->pm.rm_id != subflow->remote_id) 459 continue; 460 461 spin_unlock_bh(&msk->pm.lock); 462 mptcp_subflow_shutdown(sk, ssk, how); 463 __mptcp_close_ssk(sk, ssk, subflow); 464 spin_lock_bh(&msk->pm.lock); 465 466 msk->pm.add_addr_accepted--; 467 msk->pm.subflows--; 468 WRITE_ONCE(msk->pm.accept_addr, true); 469 470 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMADDR); 471 472 break; 473 } 474 } 475 476 void mptcp_pm_nl_rm_subflow_received(struct mptcp_sock *msk, u8 rm_id) 477 { 478 struct mptcp_subflow_context *subflow, *tmp; 479 struct sock *sk = (struct sock *)msk; 480 481 pr_debug("subflow rm_id %d", rm_id); 482 483 if (!rm_id) 484 return; 485 486 if (list_empty(&msk->conn_list)) 487 return; 488 489 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { 490 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 491 int how = RCV_SHUTDOWN | SEND_SHUTDOWN; 492 493 if (rm_id != subflow->local_id) 494 continue; 495 496 spin_unlock_bh(&msk->pm.lock); 497 mptcp_subflow_shutdown(sk, ssk, how); 498 __mptcp_close_ssk(sk, ssk, subflow); 499 spin_lock_bh(&msk->pm.lock); 500 501 msk->pm.local_addr_used--; 502 msk->pm.subflows--; 503 504 __MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RMSUBFLOW); 505 506 break; 507 } 508 } 509 510 static bool address_use_port(struct mptcp_pm_addr_entry *entry) 511 { 512 return (entry->addr.flags & 513 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) == 514 MPTCP_PM_ADDR_FLAG_SIGNAL; 515 } 516 517 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, 518 struct mptcp_pm_addr_entry *entry) 519 { 520 struct mptcp_pm_addr_entry *cur; 521 int ret = -EINVAL; 522 523 spin_lock_bh(&pernet->lock); 524 /* to keep the code simple, don't do IDR-like allocation for address ID, 525 * just bail when we exceed limits 526 */ 527 if (pernet->next_id > 255) 528 goto out; 529 if (pernet->addrs >= MPTCP_PM_ADDR_MAX) 530 goto out; 531 532 /* do not insert duplicate address, differentiate on port only 533 * singled addresses 534 */ 535 list_for_each_entry(cur, &pernet->local_addr_list, list) { 536 if (addresses_equal(&cur->addr, &entry->addr, 537 address_use_port(entry) && 538 address_use_port(cur))) 539 goto out; 540 } 541 542 if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) 543 pernet->add_addr_signal_max++; 544 if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) 545 pernet->local_addr_max++; 546 547 entry->addr.id = pernet->next_id++; 548 pernet->addrs++; 549 list_add_tail_rcu(&entry->list, &pernet->local_addr_list); 550 ret = entry->addr.id; 551 552 out: 553 spin_unlock_bh(&pernet->lock); 554 return ret; 555 } 556 557 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, struct sock_common *skc) 558 { 559 struct mptcp_pm_addr_entry *entry; 560 struct mptcp_addr_info skc_local; 561 struct mptcp_addr_info msk_local; 562 struct pm_nl_pernet *pernet; 563 int ret = -1; 564 565 if (WARN_ON_ONCE(!msk)) 566 return -1; 567 568 /* The 0 ID mapping is defined by the first subflow, copied into the msk 569 * addr 570 */ 571 local_address((struct sock_common *)msk, &msk_local); 572 local_address((struct sock_common *)skc, &skc_local); 573 if (addresses_equal(&msk_local, &skc_local, false)) 574 return 0; 575 576 if (address_zero(&skc_local)) 577 return 0; 578 579 pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id); 580 581 rcu_read_lock(); 582 list_for_each_entry_rcu(entry, &pernet->local_addr_list, list) { 583 if (addresses_equal(&entry->addr, &skc_local, false)) { 584 ret = entry->addr.id; 585 break; 586 } 587 } 588 rcu_read_unlock(); 589 if (ret >= 0) 590 return ret; 591 592 /* address not found, add to local list */ 593 entry = kmalloc(sizeof(*entry), GFP_ATOMIC); 594 if (!entry) 595 return -ENOMEM; 596 597 entry->addr = skc_local; 598 entry->addr.ifindex = 0; 599 entry->addr.flags = 0; 600 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); 601 if (ret < 0) 602 kfree(entry); 603 604 return ret; 605 } 606 607 void mptcp_pm_nl_data_init(struct mptcp_sock *msk) 608 { 609 struct mptcp_pm_data *pm = &msk->pm; 610 struct pm_nl_pernet *pernet; 611 bool subflows; 612 613 pernet = net_generic(sock_net((struct sock *)msk), pm_nl_pernet_id); 614 615 pm->add_addr_signal_max = READ_ONCE(pernet->add_addr_signal_max); 616 pm->add_addr_accept_max = READ_ONCE(pernet->add_addr_accept_max); 617 pm->local_addr_max = READ_ONCE(pernet->local_addr_max); 618 pm->subflows_max = READ_ONCE(pernet->subflows_max); 619 subflows = !!pm->subflows_max; 620 WRITE_ONCE(pm->work_pending, (!!pm->local_addr_max && subflows) || 621 !!pm->add_addr_signal_max); 622 WRITE_ONCE(pm->accept_addr, !!pm->add_addr_accept_max && subflows); 623 WRITE_ONCE(pm->accept_subflow, subflows); 624 } 625 626 #define MPTCP_PM_CMD_GRP_OFFSET 0 627 628 static const struct genl_multicast_group mptcp_pm_mcgrps[] = { 629 [MPTCP_PM_CMD_GRP_OFFSET] = { .name = MPTCP_PM_CMD_GRP_NAME, }, 630 }; 631 632 static const struct nla_policy 633 mptcp_pm_addr_policy[MPTCP_PM_ADDR_ATTR_MAX + 1] = { 634 [MPTCP_PM_ADDR_ATTR_FAMILY] = { .type = NLA_U16, }, 635 [MPTCP_PM_ADDR_ATTR_ID] = { .type = NLA_U8, }, 636 [MPTCP_PM_ADDR_ATTR_ADDR4] = { .type = NLA_U32, }, 637 [MPTCP_PM_ADDR_ATTR_ADDR6] = 638 NLA_POLICY_EXACT_LEN(sizeof(struct in6_addr)), 639 [MPTCP_PM_ADDR_ATTR_PORT] = { .type = NLA_U16 }, 640 [MPTCP_PM_ADDR_ATTR_FLAGS] = { .type = NLA_U32 }, 641 [MPTCP_PM_ADDR_ATTR_IF_IDX] = { .type = NLA_S32 }, 642 }; 643 644 static const struct nla_policy mptcp_pm_policy[MPTCP_PM_ATTR_MAX + 1] = { 645 [MPTCP_PM_ATTR_ADDR] = 646 NLA_POLICY_NESTED(mptcp_pm_addr_policy), 647 [MPTCP_PM_ATTR_RCV_ADD_ADDRS] = { .type = NLA_U32, }, 648 [MPTCP_PM_ATTR_SUBFLOWS] = { .type = NLA_U32, }, 649 }; 650 651 static int mptcp_pm_family_to_addr(int family) 652 { 653 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 654 if (family == AF_INET6) 655 return MPTCP_PM_ADDR_ATTR_ADDR6; 656 #endif 657 return MPTCP_PM_ADDR_ATTR_ADDR4; 658 } 659 660 static int mptcp_pm_parse_addr(struct nlattr *attr, struct genl_info *info, 661 bool require_family, 662 struct mptcp_pm_addr_entry *entry) 663 { 664 struct nlattr *tb[MPTCP_PM_ADDR_ATTR_MAX + 1]; 665 int err, addr_addr; 666 667 if (!attr) { 668 GENL_SET_ERR_MSG(info, "missing address info"); 669 return -EINVAL; 670 } 671 672 /* no validation needed - was already done via nested policy */ 673 err = nla_parse_nested_deprecated(tb, MPTCP_PM_ADDR_ATTR_MAX, attr, 674 mptcp_pm_addr_policy, info->extack); 675 if (err) 676 return err; 677 678 memset(entry, 0, sizeof(*entry)); 679 if (!tb[MPTCP_PM_ADDR_ATTR_FAMILY]) { 680 if (!require_family) 681 goto skip_family; 682 683 NL_SET_ERR_MSG_ATTR(info->extack, attr, 684 "missing family"); 685 return -EINVAL; 686 } 687 688 entry->addr.family = nla_get_u16(tb[MPTCP_PM_ADDR_ATTR_FAMILY]); 689 if (entry->addr.family != AF_INET 690 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 691 && entry->addr.family != AF_INET6 692 #endif 693 ) { 694 NL_SET_ERR_MSG_ATTR(info->extack, attr, 695 "unknown address family"); 696 return -EINVAL; 697 } 698 addr_addr = mptcp_pm_family_to_addr(entry->addr.family); 699 if (!tb[addr_addr]) { 700 NL_SET_ERR_MSG_ATTR(info->extack, attr, 701 "missing address data"); 702 return -EINVAL; 703 } 704 705 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 706 if (entry->addr.family == AF_INET6) 707 entry->addr.addr6 = nla_get_in6_addr(tb[addr_addr]); 708 else 709 #endif 710 entry->addr.addr.s_addr = nla_get_in_addr(tb[addr_addr]); 711 712 skip_family: 713 if (tb[MPTCP_PM_ADDR_ATTR_IF_IDX]) { 714 u32 val = nla_get_s32(tb[MPTCP_PM_ADDR_ATTR_IF_IDX]); 715 716 entry->addr.ifindex = val; 717 } 718 719 if (tb[MPTCP_PM_ADDR_ATTR_ID]) 720 entry->addr.id = nla_get_u8(tb[MPTCP_PM_ADDR_ATTR_ID]); 721 722 if (tb[MPTCP_PM_ADDR_ATTR_FLAGS]) 723 entry->addr.flags = nla_get_u32(tb[MPTCP_PM_ADDR_ATTR_FLAGS]); 724 725 return 0; 726 } 727 728 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info) 729 { 730 return net_generic(genl_info_net(info), pm_nl_pernet_id); 731 } 732 733 static int mptcp_nl_cmd_add_addr(struct sk_buff *skb, struct genl_info *info) 734 { 735 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; 736 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 737 struct mptcp_pm_addr_entry addr, *entry; 738 int ret; 739 740 ret = mptcp_pm_parse_addr(attr, info, true, &addr); 741 if (ret < 0) 742 return ret; 743 744 entry = kmalloc(sizeof(*entry), GFP_KERNEL); 745 if (!entry) { 746 GENL_SET_ERR_MSG(info, "can't allocate addr"); 747 return -ENOMEM; 748 } 749 750 *entry = addr; 751 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry); 752 if (ret < 0) { 753 GENL_SET_ERR_MSG(info, "too many addresses or duplicate one"); 754 kfree(entry); 755 return ret; 756 } 757 758 return 0; 759 } 760 761 static struct mptcp_pm_addr_entry * 762 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id) 763 { 764 struct mptcp_pm_addr_entry *entry; 765 766 list_for_each_entry(entry, &pernet->local_addr_list, list) { 767 if (entry->addr.id == id) 768 return entry; 769 } 770 return NULL; 771 } 772 773 static bool remove_anno_list_by_saddr(struct mptcp_sock *msk, 774 struct mptcp_addr_info *addr) 775 { 776 struct mptcp_pm_add_entry *entry; 777 778 entry = mptcp_pm_del_add_timer(msk, addr); 779 if (entry) { 780 list_del(&entry->list); 781 kfree(entry); 782 return true; 783 } 784 785 return false; 786 } 787 788 static bool mptcp_pm_remove_anno_addr(struct mptcp_sock *msk, 789 struct mptcp_addr_info *addr, 790 bool force) 791 { 792 bool ret; 793 794 ret = remove_anno_list_by_saddr(msk, addr); 795 if (ret || force) { 796 spin_lock_bh(&msk->pm.lock); 797 mptcp_pm_remove_addr(msk, addr->id); 798 spin_unlock_bh(&msk->pm.lock); 799 } 800 return ret; 801 } 802 803 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net, 804 struct mptcp_addr_info *addr) 805 { 806 struct mptcp_sock *msk; 807 long s_slot = 0, s_num = 0; 808 809 pr_debug("remove_id=%d", addr->id); 810 811 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { 812 struct sock *sk = (struct sock *)msk; 813 bool remove_subflow; 814 815 if (list_empty(&msk->conn_list)) { 816 mptcp_pm_remove_anno_addr(msk, addr, false); 817 goto next; 818 } 819 820 lock_sock(sk); 821 remove_subflow = lookup_subflow_by_saddr(&msk->conn_list, addr); 822 mptcp_pm_remove_anno_addr(msk, addr, remove_subflow); 823 if (remove_subflow) 824 mptcp_pm_remove_subflow(msk, addr->id); 825 release_sock(sk); 826 827 next: 828 sock_put(sk); 829 cond_resched(); 830 } 831 832 return 0; 833 } 834 835 static int mptcp_nl_cmd_del_addr(struct sk_buff *skb, struct genl_info *info) 836 { 837 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; 838 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 839 struct mptcp_pm_addr_entry addr, *entry; 840 int ret; 841 842 ret = mptcp_pm_parse_addr(attr, info, false, &addr); 843 if (ret < 0) 844 return ret; 845 846 spin_lock_bh(&pernet->lock); 847 entry = __lookup_addr_by_id(pernet, addr.addr.id); 848 if (!entry) { 849 GENL_SET_ERR_MSG(info, "address not found"); 850 spin_unlock_bh(&pernet->lock); 851 return -EINVAL; 852 } 853 if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL) 854 pernet->add_addr_signal_max--; 855 if (entry->addr.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) 856 pernet->local_addr_max--; 857 858 pernet->addrs--; 859 list_del_rcu(&entry->list); 860 spin_unlock_bh(&pernet->lock); 861 862 mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), &entry->addr); 863 kfree_rcu(entry, rcu); 864 865 return ret; 866 } 867 868 static void __flush_addrs(struct net *net, struct list_head *list) 869 { 870 while (!list_empty(list)) { 871 struct mptcp_pm_addr_entry *cur; 872 873 cur = list_entry(list->next, 874 struct mptcp_pm_addr_entry, list); 875 mptcp_nl_remove_subflow_and_signal_addr(net, &cur->addr); 876 list_del_rcu(&cur->list); 877 kfree_rcu(cur, rcu); 878 } 879 } 880 881 static void __reset_counters(struct pm_nl_pernet *pernet) 882 { 883 pernet->add_addr_signal_max = 0; 884 pernet->add_addr_accept_max = 0; 885 pernet->local_addr_max = 0; 886 pernet->addrs = 0; 887 } 888 889 static int mptcp_nl_cmd_flush_addrs(struct sk_buff *skb, struct genl_info *info) 890 { 891 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 892 LIST_HEAD(free_list); 893 894 spin_lock_bh(&pernet->lock); 895 list_splice_init(&pernet->local_addr_list, &free_list); 896 __reset_counters(pernet); 897 spin_unlock_bh(&pernet->lock); 898 __flush_addrs(sock_net(skb->sk), &free_list); 899 return 0; 900 } 901 902 static int mptcp_nl_fill_addr(struct sk_buff *skb, 903 struct mptcp_pm_addr_entry *entry) 904 { 905 struct mptcp_addr_info *addr = &entry->addr; 906 struct nlattr *attr; 907 908 attr = nla_nest_start(skb, MPTCP_PM_ATTR_ADDR); 909 if (!attr) 910 return -EMSGSIZE; 911 912 if (nla_put_u16(skb, MPTCP_PM_ADDR_ATTR_FAMILY, addr->family)) 913 goto nla_put_failure; 914 if (nla_put_u8(skb, MPTCP_PM_ADDR_ATTR_ID, addr->id)) 915 goto nla_put_failure; 916 if (nla_put_u32(skb, MPTCP_PM_ADDR_ATTR_FLAGS, entry->addr.flags)) 917 goto nla_put_failure; 918 if (entry->addr.ifindex && 919 nla_put_s32(skb, MPTCP_PM_ADDR_ATTR_IF_IDX, entry->addr.ifindex)) 920 goto nla_put_failure; 921 922 if (addr->family == AF_INET && 923 nla_put_in_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR4, 924 addr->addr.s_addr)) 925 goto nla_put_failure; 926 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 927 else if (addr->family == AF_INET6 && 928 nla_put_in6_addr(skb, MPTCP_PM_ADDR_ATTR_ADDR6, &addr->addr6)) 929 goto nla_put_failure; 930 #endif 931 nla_nest_end(skb, attr); 932 return 0; 933 934 nla_put_failure: 935 nla_nest_cancel(skb, attr); 936 return -EMSGSIZE; 937 } 938 939 static int mptcp_nl_cmd_get_addr(struct sk_buff *skb, struct genl_info *info) 940 { 941 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; 942 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 943 struct mptcp_pm_addr_entry addr, *entry; 944 struct sk_buff *msg; 945 void *reply; 946 int ret; 947 948 ret = mptcp_pm_parse_addr(attr, info, false, &addr); 949 if (ret < 0) 950 return ret; 951 952 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 953 if (!msg) 954 return -ENOMEM; 955 956 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0, 957 info->genlhdr->cmd); 958 if (!reply) { 959 GENL_SET_ERR_MSG(info, "not enough space in Netlink message"); 960 ret = -EMSGSIZE; 961 goto fail; 962 } 963 964 spin_lock_bh(&pernet->lock); 965 entry = __lookup_addr_by_id(pernet, addr.addr.id); 966 if (!entry) { 967 GENL_SET_ERR_MSG(info, "address not found"); 968 ret = -EINVAL; 969 goto unlock_fail; 970 } 971 972 ret = mptcp_nl_fill_addr(msg, entry); 973 if (ret) 974 goto unlock_fail; 975 976 genlmsg_end(msg, reply); 977 ret = genlmsg_reply(msg, info); 978 spin_unlock_bh(&pernet->lock); 979 return ret; 980 981 unlock_fail: 982 spin_unlock_bh(&pernet->lock); 983 984 fail: 985 nlmsg_free(msg); 986 return ret; 987 } 988 989 static int mptcp_nl_cmd_dump_addrs(struct sk_buff *msg, 990 struct netlink_callback *cb) 991 { 992 struct net *net = sock_net(msg->sk); 993 struct mptcp_pm_addr_entry *entry; 994 struct pm_nl_pernet *pernet; 995 int id = cb->args[0]; 996 void *hdr; 997 998 pernet = net_generic(net, pm_nl_pernet_id); 999 1000 spin_lock_bh(&pernet->lock); 1001 list_for_each_entry(entry, &pernet->local_addr_list, list) { 1002 if (entry->addr.id <= id) 1003 continue; 1004 1005 hdr = genlmsg_put(msg, NETLINK_CB(cb->skb).portid, 1006 cb->nlh->nlmsg_seq, &mptcp_genl_family, 1007 NLM_F_MULTI, MPTCP_PM_CMD_GET_ADDR); 1008 if (!hdr) 1009 break; 1010 1011 if (mptcp_nl_fill_addr(msg, entry) < 0) { 1012 genlmsg_cancel(msg, hdr); 1013 break; 1014 } 1015 1016 id = entry->addr.id; 1017 genlmsg_end(msg, hdr); 1018 } 1019 spin_unlock_bh(&pernet->lock); 1020 1021 cb->args[0] = id; 1022 return msg->len; 1023 } 1024 1025 static int parse_limit(struct genl_info *info, int id, unsigned int *limit) 1026 { 1027 struct nlattr *attr = info->attrs[id]; 1028 1029 if (!attr) 1030 return 0; 1031 1032 *limit = nla_get_u32(attr); 1033 if (*limit > MPTCP_PM_ADDR_MAX) { 1034 GENL_SET_ERR_MSG(info, "limit greater than maximum"); 1035 return -EINVAL; 1036 } 1037 return 0; 1038 } 1039 1040 static int 1041 mptcp_nl_cmd_set_limits(struct sk_buff *skb, struct genl_info *info) 1042 { 1043 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1044 unsigned int rcv_addrs, subflows; 1045 int ret; 1046 1047 spin_lock_bh(&pernet->lock); 1048 rcv_addrs = pernet->add_addr_accept_max; 1049 ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs); 1050 if (ret) 1051 goto unlock; 1052 1053 subflows = pernet->subflows_max; 1054 ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows); 1055 if (ret) 1056 goto unlock; 1057 1058 WRITE_ONCE(pernet->add_addr_accept_max, rcv_addrs); 1059 WRITE_ONCE(pernet->subflows_max, subflows); 1060 1061 unlock: 1062 spin_unlock_bh(&pernet->lock); 1063 return ret; 1064 } 1065 1066 static int 1067 mptcp_nl_cmd_get_limits(struct sk_buff *skb, struct genl_info *info) 1068 { 1069 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1070 struct sk_buff *msg; 1071 void *reply; 1072 1073 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1074 if (!msg) 1075 return -ENOMEM; 1076 1077 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0, 1078 MPTCP_PM_CMD_GET_LIMITS); 1079 if (!reply) 1080 goto fail; 1081 1082 if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS, 1083 READ_ONCE(pernet->add_addr_accept_max))) 1084 goto fail; 1085 1086 if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS, 1087 READ_ONCE(pernet->subflows_max))) 1088 goto fail; 1089 1090 genlmsg_end(msg, reply); 1091 return genlmsg_reply(msg, info); 1092 1093 fail: 1094 GENL_SET_ERR_MSG(info, "not enough space in Netlink message"); 1095 nlmsg_free(msg); 1096 return -EMSGSIZE; 1097 } 1098 1099 static const struct genl_small_ops mptcp_pm_ops[] = { 1100 { 1101 .cmd = MPTCP_PM_CMD_ADD_ADDR, 1102 .doit = mptcp_nl_cmd_add_addr, 1103 .flags = GENL_ADMIN_PERM, 1104 }, 1105 { 1106 .cmd = MPTCP_PM_CMD_DEL_ADDR, 1107 .doit = mptcp_nl_cmd_del_addr, 1108 .flags = GENL_ADMIN_PERM, 1109 }, 1110 { 1111 .cmd = MPTCP_PM_CMD_FLUSH_ADDRS, 1112 .doit = mptcp_nl_cmd_flush_addrs, 1113 .flags = GENL_ADMIN_PERM, 1114 }, 1115 { 1116 .cmd = MPTCP_PM_CMD_GET_ADDR, 1117 .doit = mptcp_nl_cmd_get_addr, 1118 .dumpit = mptcp_nl_cmd_dump_addrs, 1119 }, 1120 { 1121 .cmd = MPTCP_PM_CMD_SET_LIMITS, 1122 .doit = mptcp_nl_cmd_set_limits, 1123 .flags = GENL_ADMIN_PERM, 1124 }, 1125 { 1126 .cmd = MPTCP_PM_CMD_GET_LIMITS, 1127 .doit = mptcp_nl_cmd_get_limits, 1128 }, 1129 }; 1130 1131 static struct genl_family mptcp_genl_family __ro_after_init = { 1132 .name = MPTCP_PM_NAME, 1133 .version = MPTCP_PM_VER, 1134 .maxattr = MPTCP_PM_ATTR_MAX, 1135 .policy = mptcp_pm_policy, 1136 .netnsok = true, 1137 .module = THIS_MODULE, 1138 .small_ops = mptcp_pm_ops, 1139 .n_small_ops = ARRAY_SIZE(mptcp_pm_ops), 1140 .mcgrps = mptcp_pm_mcgrps, 1141 .n_mcgrps = ARRAY_SIZE(mptcp_pm_mcgrps), 1142 }; 1143 1144 static int __net_init pm_nl_init_net(struct net *net) 1145 { 1146 struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id); 1147 1148 INIT_LIST_HEAD_RCU(&pernet->local_addr_list); 1149 __reset_counters(pernet); 1150 pernet->next_id = 1; 1151 spin_lock_init(&pernet->lock); 1152 return 0; 1153 } 1154 1155 static void __net_exit pm_nl_exit_net(struct list_head *net_list) 1156 { 1157 struct net *net; 1158 1159 list_for_each_entry(net, net_list, exit_list) { 1160 struct pm_nl_pernet *pernet = net_generic(net, pm_nl_pernet_id); 1161 1162 /* net is removed from namespace list, can't race with 1163 * other modifiers 1164 */ 1165 __flush_addrs(net, &pernet->local_addr_list); 1166 } 1167 } 1168 1169 static struct pernet_operations mptcp_pm_pernet_ops = { 1170 .init = pm_nl_init_net, 1171 .exit_batch = pm_nl_exit_net, 1172 .id = &pm_nl_pernet_id, 1173 .size = sizeof(struct pm_nl_pernet), 1174 }; 1175 1176 void __init mptcp_pm_nl_init(void) 1177 { 1178 if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0) 1179 panic("Failed to register MPTCP PM pernet subsystem.\n"); 1180 1181 if (genl_register_family(&mptcp_genl_family)) 1182 panic("Failed to register MPTCP PM netlink family\n"); 1183 } 1184