1 // SPDX-License-Identifier: GPL-2.0 2 /* Multipath TCP 3 * 4 * Copyright (c) 2025, Matthieu Baerts. 5 */ 6 7 #define pr_fmt(fmt) "MPTCP: " fmt 8 9 #include <net/netns/generic.h> 10 11 #include "protocol.h" 12 #include "mib.h" 13 #include "mptcp_pm_gen.h" 14 15 static int pm_nl_pernet_id; 16 17 struct pm_nl_pernet { 18 /* protects pernet updates */ 19 spinlock_t lock; 20 struct list_head endp_list; 21 u8 endpoints; 22 u8 endp_signal_max; 23 u8 endp_subflow_max; 24 u8 endp_laminar_max; 25 u8 endp_fullmesh_max; 26 u8 limit_add_addr_accepted; 27 u8 limit_extra_subflows; 28 u8 next_id; 29 DECLARE_BITMAP(id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); 30 }; 31 32 #define MPTCP_PM_ADDR_MAX 8 33 #define MPTCP_PM_SUBFLOWS_MAX 64 34 35 static struct pm_nl_pernet *pm_nl_get_pernet(const struct net *net) 36 { 37 return net_generic(net, pm_nl_pernet_id); 38 } 39 40 static struct pm_nl_pernet * 41 pm_nl_get_pernet_from_msk(const struct mptcp_sock *msk) 42 { 43 return pm_nl_get_pernet(sock_net((struct sock *)msk)); 44 } 45 46 static struct pm_nl_pernet *genl_info_pm_nl(struct genl_info *info) 47 { 48 return pm_nl_get_pernet(genl_info_net(info)); 49 } 50 51 u8 mptcp_pm_get_endp_signal_max(const struct mptcp_sock *msk) 52 { 53 const struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 54 55 return READ_ONCE(pernet->endp_signal_max); 56 } 57 EXPORT_SYMBOL_GPL(mptcp_pm_get_endp_signal_max); 58 59 u8 mptcp_pm_get_endp_subflow_max(const struct mptcp_sock *msk) 60 { 61 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 62 63 return READ_ONCE(pernet->endp_subflow_max); 64 } 65 EXPORT_SYMBOL_GPL(mptcp_pm_get_endp_subflow_max); 66 67 u8 mptcp_pm_get_endp_laminar_max(const struct mptcp_sock *msk) 68 { 69 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 70 71 return READ_ONCE(pernet->endp_laminar_max); 72 } 73 EXPORT_SYMBOL_GPL(mptcp_pm_get_endp_laminar_max); 74 75 u8 mptcp_pm_get_endp_fullmesh_max(const struct mptcp_sock *msk) 76 { 77 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 78 79 return READ_ONCE(pernet->endp_fullmesh_max); 80 } 81 EXPORT_SYMBOL_GPL(mptcp_pm_get_endp_fullmesh_max); 82 83 u8 mptcp_pm_get_limit_add_addr_accepted(const struct mptcp_sock *msk) 84 { 85 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 86 87 return READ_ONCE(pernet->limit_add_addr_accepted); 88 } 89 EXPORT_SYMBOL_GPL(mptcp_pm_get_limit_add_addr_accepted); 90 91 u8 mptcp_pm_get_limit_extra_subflows(const struct mptcp_sock *msk) 92 { 93 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 94 95 return READ_ONCE(pernet->limit_extra_subflows); 96 } 97 EXPORT_SYMBOL_GPL(mptcp_pm_get_limit_extra_subflows); 98 99 static bool has_subflow_daddr(const struct mptcp_sock *msk, 100 const struct mptcp_addr_info *daddr) 101 { 102 struct mptcp_subflow_context *subflow; 103 struct mptcp_addr_info cur; 104 105 mptcp_for_each_subflow(msk, subflow) { 106 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 107 108 if (!((1 << inet_sk_state_load(ssk)) & 109 (TCPF_ESTABLISHED | TCPF_SYN_SENT | TCPF_SYN_RECV))) 110 continue; 111 112 mptcp_remote_address((struct sock_common *)ssk, &cur); 113 if (mptcp_addresses_equal(&cur, daddr, daddr->port)) 114 return true; 115 } 116 117 return false; 118 } 119 120 static bool 121 select_local_address(const struct pm_nl_pernet *pernet, 122 const struct mptcp_sock *msk, 123 struct mptcp_pm_local *new_local) 124 { 125 struct mptcp_pm_addr_entry *entry; 126 bool found = false; 127 128 msk_owned_by_me(msk); 129 130 rcu_read_lock(); 131 list_for_each_entry_rcu(entry, &pernet->endp_list, list) { 132 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)) 133 continue; 134 135 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap)) 136 continue; 137 138 new_local->addr = entry->addr; 139 new_local->flags = entry->flags; 140 new_local->ifindex = entry->ifindex; 141 found = true; 142 break; 143 } 144 rcu_read_unlock(); 145 146 return found; 147 } 148 149 static bool 150 select_signal_address(struct pm_nl_pernet *pernet, const struct mptcp_sock *msk, 151 struct mptcp_pm_local *new_local) 152 { 153 struct mptcp_pm_addr_entry *entry; 154 bool found = false; 155 156 rcu_read_lock(); 157 /* do not keep any additional per socket state, just signal 158 * the address list in order. 159 * Note: removal from the local address list during the msk life-cycle 160 * can lead to additional addresses not being announced. 161 */ 162 list_for_each_entry_rcu(entry, &pernet->endp_list, list) { 163 if (!test_bit(entry->addr.id, msk->pm.id_avail_bitmap)) 164 continue; 165 166 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL)) 167 continue; 168 169 new_local->addr = entry->addr; 170 new_local->flags = entry->flags; 171 new_local->ifindex = entry->ifindex; 172 found = true; 173 break; 174 } 175 rcu_read_unlock(); 176 177 return found; 178 } 179 180 static unsigned int 181 fill_remote_addr(struct mptcp_sock *msk, struct mptcp_addr_info *local, 182 struct mptcp_addr_info *addrs) 183 { 184 bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0); 185 struct mptcp_addr_info remote = { 0 }; 186 struct sock *sk = (struct sock *)msk; 187 188 if (deny_id0) 189 return 0; 190 191 mptcp_remote_address((struct sock_common *)sk, &remote); 192 193 if (!mptcp_pm_addr_families_match(sk, local, &remote)) 194 return 0; 195 196 msk->pm.extra_subflows++; 197 *addrs = remote; 198 199 return 1; 200 } 201 202 static unsigned int 203 fill_remote_addresses_fullmesh(struct mptcp_sock *msk, 204 struct mptcp_addr_info *local, 205 struct mptcp_addr_info *addrs, 206 int addrs_size) 207 { 208 u8 limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk); 209 bool deny_id0 = READ_ONCE(msk->pm.remote_deny_join_id0); 210 DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1); 211 struct sock *sk = (struct sock *)msk, *ssk; 212 struct mptcp_subflow_context *subflow; 213 int i = 0; 214 215 /* Forbid creation of new subflows matching existing ones, possibly 216 * already created by incoming ADD_ADDR 217 */ 218 bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1); 219 mptcp_for_each_subflow(msk, subflow) 220 if (READ_ONCE(subflow->local_id) == local->id) 221 __set_bit(subflow->remote_id, unavail_id); 222 223 mptcp_for_each_subflow(msk, subflow) { 224 ssk = mptcp_subflow_tcp_sock(subflow); 225 mptcp_remote_address((struct sock_common *)ssk, &addrs[i]); 226 addrs[i].id = READ_ONCE(subflow->remote_id); 227 if (deny_id0 && !addrs[i].id) 228 continue; 229 230 if (test_bit(addrs[i].id, unavail_id)) 231 continue; 232 233 if (!mptcp_pm_addr_families_match(sk, local, &addrs[i])) 234 continue; 235 236 /* forbid creating multiple address towards this id */ 237 __set_bit(addrs[i].id, unavail_id); 238 msk->pm.extra_subflows++; 239 i++; 240 241 if (msk->pm.extra_subflows >= limit_extra_subflows || 242 i == addrs_size) 243 break; 244 } 245 246 return i; 247 } 248 249 /* Fill all the remote addresses into the array addrs[], 250 * and return the array size. 251 */ 252 static unsigned int 253 fill_remote_addresses_vec(struct mptcp_sock *msk, struct mptcp_addr_info *local, 254 bool fullmesh, struct mptcp_addr_info *addrs, 255 int addrs_size) 256 { 257 /* Non-fullmesh: fill in the single entry corresponding to the primary 258 * MPC subflow remote address, and return 1, corresponding to 1 entry. 259 */ 260 if (!fullmesh) 261 return fill_remote_addr(msk, local, addrs); 262 263 /* Fullmesh endpoint: fill all possible remote addresses */ 264 return fill_remote_addresses_fullmesh(msk, local, addrs, addrs_size); 265 } 266 267 static struct mptcp_pm_addr_entry * 268 __lookup_addr_by_id(struct pm_nl_pernet *pernet, unsigned int id) 269 { 270 struct mptcp_pm_addr_entry *entry; 271 272 list_for_each_entry_rcu(entry, &pernet->endp_list, list, 273 lockdep_is_held(&pernet->lock)) { 274 if (entry->addr.id == id) 275 return entry; 276 } 277 return NULL; 278 } 279 280 static struct mptcp_pm_addr_entry * 281 __lookup_addr(struct pm_nl_pernet *pernet, const struct mptcp_addr_info *info) 282 { 283 struct mptcp_pm_addr_entry *entry; 284 285 list_for_each_entry_rcu(entry, &pernet->endp_list, list, 286 lockdep_is_held(&pernet->lock)) { 287 if (mptcp_addresses_equal(&entry->addr, info, entry->addr.port)) 288 return entry; 289 } 290 return NULL; 291 } 292 293 static u8 mptcp_endp_get_local_id(struct mptcp_sock *msk, 294 const struct mptcp_addr_info *addr) 295 { 296 return msk->mpc_endpoint_id == addr->id ? 0 : addr->id; 297 } 298 299 /* Set mpc_endpoint_id, and send MP_PRIO for ID0 if needed */ 300 static void mptcp_mpc_endpoint_setup(struct mptcp_sock *msk) 301 { 302 struct mptcp_subflow_context *subflow; 303 struct mptcp_pm_addr_entry *entry; 304 struct mptcp_addr_info mpc_addr; 305 struct pm_nl_pernet *pernet; 306 bool backup = false; 307 308 /* do lazy endpoint usage accounting for the MPC subflows */ 309 if (likely(msk->pm.status & BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED)) || 310 !msk->first) 311 return; 312 313 subflow = mptcp_subflow_ctx(msk->first); 314 pernet = pm_nl_get_pernet_from_msk(msk); 315 316 mptcp_local_address((struct sock_common *)msk->first, &mpc_addr); 317 rcu_read_lock(); 318 entry = __lookup_addr(pernet, &mpc_addr); 319 if (entry) { 320 __clear_bit(entry->addr.id, msk->pm.id_avail_bitmap); 321 msk->mpc_endpoint_id = entry->addr.id; 322 backup = !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); 323 } 324 rcu_read_unlock(); 325 326 /* Send MP_PRIO */ 327 if (backup) 328 mptcp_pm_send_ack(msk, subflow, true, backup); 329 330 msk->pm.status |= BIT(MPTCP_PM_MPC_ENDPOINT_ACCOUNTED); 331 } 332 333 static void mptcp_pm_create_subflow_or_signal_addr(struct mptcp_sock *msk) 334 { 335 u8 limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk); 336 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 337 u8 endp_subflow_max = mptcp_pm_get_endp_subflow_max(msk); 338 u8 endp_signal_max = mptcp_pm_get_endp_signal_max(msk); 339 struct sock *sk = (struct sock *)msk; 340 bool signal_and_subflow = false; 341 struct mptcp_pm_local local; 342 343 mptcp_mpc_endpoint_setup(msk); 344 if (!mptcp_is_fully_established(sk)) 345 return; 346 347 pr_debug("local %d:%d signal %d:%d subflows %d:%d\n", 348 msk->pm.local_addr_used, endp_subflow_max, 349 msk->pm.add_addr_signaled, endp_signal_max, 350 msk->pm.extra_subflows, limit_extra_subflows); 351 352 /* check first for announce */ 353 if (msk->pm.add_addr_signaled < endp_signal_max) { 354 u8 endp_id; 355 356 /* due to racing events on both ends we can reach here while 357 * previous add address is still running: if we invoke now 358 * mptcp_pm_announce_addr(), that will fail and the 359 * corresponding id will be marked as used. 360 * Instead let the PM machinery reschedule us when the 361 * current address announce will be completed. 362 */ 363 if (msk->pm.addr_signal & BIT(MPTCP_ADD_ADDR_SIGNAL)) 364 return; 365 366 if (!select_signal_address(pernet, msk, &local)) 367 goto subflow; 368 369 /* Special case for ID0: set the correct ID */ 370 endp_id = local.addr.id; 371 if (endp_id == msk->mpc_endpoint_id) 372 local.addr.id = 0; 373 374 /* If the alloc fails, we are on memory pressure, not worth 375 * continuing, and trying to create subflows. 376 */ 377 if (!mptcp_pm_announced_alloc(msk, &local.addr)) 378 return; 379 380 __clear_bit(endp_id, msk->pm.id_avail_bitmap); 381 msk->pm.add_addr_signaled++; 382 383 mptcp_pm_announce_addr(msk, &local.addr, false); 384 mptcp_pm_addr_send_ack(msk); 385 386 if (local.flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) 387 signal_and_subflow = true; 388 } 389 390 subflow: 391 /* No need to try establishing subflows to remote id0 if not allowed */ 392 if (mptcp_pm_add_addr_c_flag_case(msk)) 393 goto exit; 394 395 /* check if should create a new subflow */ 396 while (msk->pm.local_addr_used < endp_subflow_max && 397 msk->pm.extra_subflows < limit_extra_subflows) { 398 struct mptcp_addr_info addrs[MPTCP_PM_ADDR_MAX]; 399 bool fullmesh; 400 int i, nr; 401 402 if (signal_and_subflow) 403 signal_and_subflow = false; 404 else if (!select_local_address(pernet, msk, &local)) 405 break; 406 407 fullmesh = !!(local.flags & MPTCP_PM_ADDR_FLAG_FULLMESH); 408 409 __clear_bit(local.addr.id, msk->pm.id_avail_bitmap); 410 411 /* Special case for ID0: set the correct ID */ 412 if (local.addr.id == msk->mpc_endpoint_id) 413 local.addr.id = 0; 414 else /* local_addr_used is not decr for ID 0 */ 415 msk->pm.local_addr_used++; 416 417 nr = fill_remote_addresses_vec(msk, &local.addr, fullmesh, 418 addrs, ARRAY_SIZE(addrs)); 419 if (nr == 0) 420 continue; 421 422 spin_unlock_bh(&msk->pm.lock); 423 for (i = 0; i < nr; i++) 424 __mptcp_subflow_connect(sk, &local, &addrs[i]); 425 spin_lock_bh(&msk->pm.lock); 426 } 427 428 exit: 429 /* If an endpoint has both the signal and subflow flags, but it is not 430 * possible to create subflows -- the 'while' loop body above never 431 * executed -- then still mark the endp as used, which is somehow the 432 * case. This avoids issues later when removing the endpoint and calling 433 * __mark_subflow_endp_available(), which expects the increment here. 434 */ 435 if (signal_and_subflow && local.addr.id != msk->mpc_endpoint_id) 436 msk->pm.local_addr_used++; 437 438 mptcp_pm_nl_check_work_pending(msk); 439 } 440 441 static void mptcp_pm_nl_fully_established(struct mptcp_sock *msk) 442 { 443 mptcp_pm_create_subflow_or_signal_addr(msk); 444 } 445 446 static void mptcp_pm_nl_subflow_established(struct mptcp_sock *msk) 447 { 448 mptcp_pm_create_subflow_or_signal_addr(msk); 449 } 450 451 static unsigned int 452 fill_local_addresses_vec_fullmesh(struct mptcp_sock *msk, 453 struct mptcp_addr_info *remote, 454 struct mptcp_pm_local *locals, 455 int locals_size, 456 bool c_flag_case) 457 { 458 u8 limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk); 459 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 460 struct sock *sk = (struct sock *)msk; 461 struct mptcp_pm_addr_entry *entry; 462 struct mptcp_pm_local *local; 463 int i = 0; 464 465 rcu_read_lock(); 466 list_for_each_entry_rcu(entry, &pernet->endp_list, list) { 467 bool is_id0; 468 469 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH)) 470 continue; 471 472 if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote)) 473 continue; 474 475 local = &locals[i]; 476 local->addr = entry->addr; 477 local->flags = entry->flags; 478 local->ifindex = entry->ifindex; 479 480 is_id0 = local->addr.id == msk->mpc_endpoint_id; 481 482 if (c_flag_case && 483 (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW)) { 484 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); 485 486 if (!is_id0) 487 msk->pm.local_addr_used++; 488 } 489 490 /* Special case for ID0: set the correct ID */ 491 if (is_id0) 492 local->addr.id = 0; 493 494 msk->pm.extra_subflows++; 495 i++; 496 497 if (msk->pm.extra_subflows >= limit_extra_subflows || 498 i == locals_size) 499 break; 500 } 501 rcu_read_unlock(); 502 503 return i; 504 } 505 506 static unsigned int 507 fill_local_laminar_endp(struct mptcp_sock *msk, struct mptcp_addr_info *remote, 508 struct mptcp_pm_local *locals) 509 { 510 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 511 DECLARE_BITMAP(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1); 512 struct mptcp_subflow_context *subflow; 513 struct sock *sk = (struct sock *)msk; 514 struct mptcp_pm_addr_entry *entry; 515 struct mptcp_pm_local *local; 516 int found = 0; 517 518 /* Forbid creation of new subflows matching existing ones, possibly 519 * already created by 'subflow' endpoints 520 */ 521 bitmap_zero(unavail_id, MPTCP_PM_MAX_ADDR_ID + 1); 522 mptcp_for_each_subflow(msk, subflow) { 523 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 524 525 if ((1 << inet_sk_state_load(ssk)) & 526 (TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2 | TCPF_CLOSING | 527 TCPF_CLOSE)) 528 continue; 529 530 __set_bit(subflow_get_local_id(subflow), unavail_id); 531 } 532 533 rcu_read_lock(); 534 list_for_each_entry_rcu(entry, &pernet->endp_list, list) { 535 if (!(entry->flags & MPTCP_PM_ADDR_FLAG_LAMINAR)) 536 continue; 537 538 if (!mptcp_pm_addr_families_match(sk, &entry->addr, remote)) 539 continue; 540 541 if (test_bit(mptcp_endp_get_local_id(msk, &entry->addr), 542 unavail_id)) 543 continue; 544 545 local = &locals[0]; 546 local->addr = entry->addr; 547 local->flags = entry->flags; 548 local->ifindex = entry->ifindex; 549 550 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { 551 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); 552 553 if (local->addr.id != msk->mpc_endpoint_id) 554 msk->pm.local_addr_used++; 555 } 556 557 msk->pm.extra_subflows++; 558 found = 1; 559 break; 560 } 561 rcu_read_unlock(); 562 563 return found; 564 } 565 566 static unsigned int 567 fill_local_addresses_vec_c_flag(struct mptcp_sock *msk, 568 struct mptcp_addr_info *remote, 569 struct mptcp_pm_local *locals, 570 int locals_size) 571 { 572 u8 limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk); 573 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 574 u8 endp_subflow_max = mptcp_pm_get_endp_subflow_max(msk); 575 struct sock *sk = (struct sock *)msk; 576 struct mptcp_pm_local *local; 577 int i = 0; 578 579 while (msk->pm.local_addr_used < endp_subflow_max) { 580 local = &locals[i]; 581 582 if (!select_local_address(pernet, msk, local)) 583 break; 584 585 __clear_bit(local->addr.id, msk->pm.id_avail_bitmap); 586 587 if (!mptcp_pm_addr_families_match(sk, &local->addr, remote)) 588 continue; 589 590 if (local->addr.id == msk->mpc_endpoint_id) 591 continue; 592 593 msk->pm.local_addr_used++; 594 msk->pm.extra_subflows++; 595 i++; 596 597 if (msk->pm.extra_subflows >= limit_extra_subflows || 598 i == locals_size) 599 break; 600 } 601 602 return i; 603 } 604 605 static unsigned int 606 fill_local_address_any(struct mptcp_sock *msk, struct mptcp_addr_info *remote, 607 struct mptcp_pm_local *local) 608 { 609 struct sock *sk = (struct sock *)msk; 610 611 memset(local, 0, sizeof(*local)); 612 local->addr.family = 613 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 614 remote->family == AF_INET6 && 615 ipv6_addr_v4mapped(&remote->addr6) ? AF_INET : 616 #endif 617 remote->family; 618 619 if (!mptcp_pm_addr_families_match(sk, &local->addr, remote)) 620 return 0; 621 622 msk->pm.extra_subflows++; 623 624 return 1; 625 } 626 627 /* Fill all the local addresses into the array addrs[], 628 * and return the array size. 629 */ 630 static unsigned int 631 fill_local_addresses_vec(struct mptcp_sock *msk, struct mptcp_addr_info *remote, 632 struct mptcp_pm_local *locals, int locals_size) 633 { 634 bool c_flag_case = remote->id && mptcp_pm_add_addr_c_flag_case(msk); 635 636 /* If there is at least one MPTCP endpoint with a fullmesh flag */ 637 if (mptcp_pm_get_endp_fullmesh_max(msk)) 638 return fill_local_addresses_vec_fullmesh(msk, remote, locals, 639 locals_size, 640 c_flag_case); 641 642 /* If there is at least one MPTCP endpoint with a laminar flag */ 643 if (mptcp_pm_get_endp_laminar_max(msk)) 644 return fill_local_laminar_endp(msk, remote, locals); 645 646 /* Special case: peer sets the C flag, accept one ADD_ADDR if default 647 * limits are used -- accepting no ADD_ADDR -- and use subflow endpoints 648 */ 649 if (c_flag_case) 650 return fill_local_addresses_vec_c_flag(msk, remote, locals, 651 locals_size); 652 653 /* No special case: fill in the single 'IPADDRANY' local address */ 654 return fill_local_address_any(msk, remote, &locals[0]); 655 } 656 657 static void mptcp_pm_nl_add_addr_received(struct mptcp_sock *msk) 658 { 659 u8 limit_add_addr_accepted = mptcp_pm_get_limit_add_addr_accepted(msk); 660 u8 limit_extra_subflows = mptcp_pm_get_limit_extra_subflows(msk); 661 struct mptcp_pm_local locals[MPTCP_PM_ADDR_MAX]; 662 struct sock *sk = (struct sock *)msk; 663 struct mptcp_addr_info remote; 664 bool sf_created = false; 665 int i, nr; 666 667 pr_debug("accepted %d:%d remote family %d\n", 668 msk->pm.add_addr_accepted, limit_add_addr_accepted, 669 msk->pm.remote.family); 670 671 remote = msk->pm.remote; 672 mptcp_pm_announce_addr(msk, &remote, true); 673 mptcp_pm_addr_send_ack(msk); 674 mptcp_mpc_endpoint_setup(msk); 675 676 if (has_subflow_daddr(msk, &remote)) 677 return; 678 679 /* pick id 0 port, if none is provided the remote address */ 680 if (!remote.port) 681 remote.port = sk->sk_dport; 682 683 /* connect to the specified remote address, using whatever 684 * local address the routing configuration will pick. 685 */ 686 nr = fill_local_addresses_vec(msk, &remote, locals, ARRAY_SIZE(locals)); 687 if (nr == 0) 688 return; 689 690 spin_unlock_bh(&msk->pm.lock); 691 for (i = 0; i < nr; i++) 692 if (__mptcp_subflow_connect(sk, &locals[i], &remote) == 0) 693 sf_created = true; 694 spin_lock_bh(&msk->pm.lock); 695 696 if (sf_created) { 697 /* add_addr_accepted is not decr for ID 0 */ 698 if (remote.id) 699 msk->pm.add_addr_accepted++; 700 if (msk->pm.add_addr_accepted >= limit_add_addr_accepted || 701 msk->pm.extra_subflows >= limit_extra_subflows) 702 WRITE_ONCE(msk->pm.accept_addr, false); 703 } 704 } 705 706 void mptcp_pm_nl_rm_addr(struct mptcp_sock *msk, u8 rm_id) 707 { 708 if (rm_id && !WARN_ON_ONCE(msk->pm.add_addr_accepted == 0)) { 709 u8 limit_add_addr_accepted = 710 mptcp_pm_get_limit_add_addr_accepted(msk); 711 712 /* Note: if the subflow has been closed before, this 713 * add_addr_accepted counter will not be decremented. 714 */ 715 if (--msk->pm.add_addr_accepted < limit_add_addr_accepted) 716 WRITE_ONCE(msk->pm.accept_addr, true); 717 } 718 } 719 720 static bool address_use_port(struct mptcp_pm_addr_entry *entry) 721 { 722 return (entry->flags & 723 (MPTCP_PM_ADDR_FLAG_SIGNAL | MPTCP_PM_ADDR_FLAG_SUBFLOW)) == 724 MPTCP_PM_ADDR_FLAG_SIGNAL; 725 } 726 727 /* caller must ensure the RCU grace period is already elapsed */ 728 static void __mptcp_pm_release_addr_entry(struct mptcp_pm_addr_entry *entry) 729 { 730 if (entry->lsk) 731 sock_release(entry->lsk); 732 kfree(entry); 733 } 734 735 static int mptcp_pm_nl_append_new_local_addr(struct pm_nl_pernet *pernet, 736 struct mptcp_pm_addr_entry *entry, 737 bool replace) 738 { 739 struct mptcp_pm_addr_entry *cur, *del_entry = NULL; 740 int ret = -EINVAL; 741 u8 addr_max; 742 743 spin_lock_bh(&pernet->lock); 744 /* to keep the code simple, don't do IDR-like allocation for address ID, 745 * just bail when we exceed limits 746 */ 747 if (pernet->next_id == MPTCP_PM_MAX_ADDR_ID) 748 pernet->next_id = 1; 749 if (pernet->endpoints == MPTCP_PM_MAX_ADDR_ID) { 750 ret = -ERANGE; 751 goto out; 752 } 753 if (test_bit(entry->addr.id, pernet->id_bitmap)) { 754 ret = -EBUSY; 755 goto out; 756 } 757 758 /* do not insert duplicate address, differentiate on port only 759 * singled addresses 760 */ 761 if (!address_use_port(entry)) 762 entry->addr.port = 0; 763 list_for_each_entry(cur, &pernet->endp_list, list) { 764 if (mptcp_addresses_equal(&cur->addr, &entry->addr, 765 cur->addr.port || entry->addr.port)) { 766 /* allow replacing the exiting endpoint only if such 767 * endpoint is an implicit one and the user-space 768 * did not provide an endpoint id 769 */ 770 if (!(cur->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)) { 771 ret = -EEXIST; 772 goto out; 773 } 774 if (entry->addr.id) 775 goto out; 776 777 /* allow callers that only need to look up the local 778 * addr's id to skip replacement. This allows them to 779 * avoid calling synchronize_rcu in the packet recv 780 * path. 781 */ 782 if (!replace) { 783 kfree(entry); 784 ret = cur->addr.id; 785 goto out; 786 } 787 788 pernet->endpoints--; 789 entry->addr.id = cur->addr.id; 790 list_del_rcu(&cur->list); 791 del_entry = cur; 792 break; 793 } 794 } 795 796 if (!entry->addr.id) { 797 find_next: 798 entry->addr.id = find_next_zero_bit(pernet->id_bitmap, 799 MPTCP_PM_MAX_ADDR_ID + 1, 800 pernet->next_id); 801 if (!entry->addr.id && pernet->next_id != 1) { 802 pernet->next_id = 1; 803 goto find_next; 804 } 805 } 806 807 if (!entry->addr.id) 808 goto out; 809 810 __set_bit(entry->addr.id, pernet->id_bitmap); 811 if (entry->addr.id > pernet->next_id) 812 pernet->next_id = entry->addr.id; 813 814 if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) { 815 addr_max = pernet->endp_signal_max; 816 WRITE_ONCE(pernet->endp_signal_max, addr_max + 1); 817 } 818 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { 819 addr_max = pernet->endp_subflow_max; 820 WRITE_ONCE(pernet->endp_subflow_max, addr_max + 1); 821 } 822 if (entry->flags & MPTCP_PM_ADDR_FLAG_LAMINAR) { 823 addr_max = pernet->endp_laminar_max; 824 WRITE_ONCE(pernet->endp_laminar_max, addr_max + 1); 825 } 826 if (entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) { 827 addr_max = pernet->endp_fullmesh_max; 828 WRITE_ONCE(pernet->endp_fullmesh_max, addr_max + 1); 829 } 830 831 pernet->endpoints++; 832 if (!entry->addr.port) 833 list_add_tail_rcu(&entry->list, &pernet->endp_list); 834 else 835 list_add_rcu(&entry->list, &pernet->endp_list); 836 ret = entry->addr.id; 837 838 out: 839 spin_unlock_bh(&pernet->lock); 840 841 /* just replaced an existing entry, free it */ 842 if (del_entry) { 843 synchronize_rcu(); 844 __mptcp_pm_release_addr_entry(del_entry); 845 } 846 return ret; 847 } 848 849 static struct lock_class_key mptcp_slock_keys[2]; 850 static struct lock_class_key mptcp_keys[2]; 851 852 static int mptcp_pm_nl_create_listen_socket(struct sock *sk, 853 struct mptcp_pm_addr_entry *entry) 854 { 855 bool is_ipv6 = entry->addr.family == AF_INET6; 856 int addrlen = sizeof(struct sockaddr_in); 857 struct sockaddr_storage addr; 858 struct sock *newsk, *ssk; 859 int backlog = 1024; 860 int err; 861 862 err = sock_create_kern(sock_net(sk), entry->addr.family, 863 SOCK_STREAM, IPPROTO_MPTCP, &entry->lsk); 864 if (err) 865 return err; 866 867 newsk = entry->lsk->sk; 868 if (!newsk) 869 return -EINVAL; 870 871 /* The subflow socket lock is acquired in a nested to the msk one 872 * in several places, even by the TCP stack, and this msk is a kernel 873 * socket: lockdep complains. Instead of propagating the _nested 874 * modifiers in several places, re-init the lock class for the msk 875 * socket to an mptcp specific one. 876 */ 877 sock_lock_init_class_and_name(newsk, 878 is_ipv6 ? "mlock-AF_INET6" : "mlock-AF_INET", 879 &mptcp_slock_keys[is_ipv6], 880 is_ipv6 ? "msk_lock-AF_INET6" : "msk_lock-AF_INET", 881 &mptcp_keys[is_ipv6]); 882 883 lock_sock(newsk); 884 ssk = __mptcp_nmpc_sk(mptcp_sk(newsk)); 885 release_sock(newsk); 886 if (IS_ERR(ssk)) 887 return PTR_ERR(ssk); 888 889 mptcp_info2sockaddr(&entry->addr, &addr, entry->addr.family); 890 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 891 if (entry->addr.family == AF_INET6) 892 addrlen = sizeof(struct sockaddr_in6); 893 #endif 894 if (ssk->sk_family == AF_INET) 895 err = inet_bind_sk(ssk, (struct sockaddr_unsized *)&addr, addrlen); 896 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 897 else if (ssk->sk_family == AF_INET6) 898 err = inet6_bind_sk(ssk, (struct sockaddr_unsized *)&addr, addrlen); 899 #endif 900 if (err) 901 return err; 902 903 /* We don't use mptcp_set_state() here because it needs to be called 904 * under the msk socket lock. For the moment, that will not bring 905 * anything more than only calling inet_sk_state_store(), because the 906 * old status is known (TCP_CLOSE). 907 */ 908 inet_sk_state_store(newsk, TCP_LISTEN); 909 lock_sock(ssk); 910 WRITE_ONCE(mptcp_subflow_ctx(ssk)->pm_listener, true); 911 err = __inet_listen_sk(ssk, backlog); 912 if (!err) 913 mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CREATED); 914 release_sock(ssk); 915 return err; 916 } 917 918 int mptcp_pm_nl_get_local_id(struct mptcp_sock *msk, 919 struct mptcp_pm_addr_entry *skc) 920 { 921 struct mptcp_pm_addr_entry *entry; 922 struct pm_nl_pernet *pernet; 923 int ret; 924 925 pernet = pm_nl_get_pernet_from_msk(msk); 926 927 rcu_read_lock(); 928 entry = __lookup_addr(pernet, &skc->addr); 929 ret = entry ? entry->addr.id : -1; 930 rcu_read_unlock(); 931 if (ret >= 0) 932 return ret; 933 934 /* address not found, add to local list */ 935 entry = kmemdup(skc, sizeof(*skc), GFP_ATOMIC); 936 if (!entry) 937 return -ENOMEM; 938 939 entry->addr.port = 0; 940 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, false); 941 if (ret < 0) 942 kfree(entry); 943 944 return ret; 945 } 946 947 bool mptcp_pm_nl_is_backup(struct mptcp_sock *msk, struct mptcp_addr_info *skc) 948 { 949 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 950 struct mptcp_pm_addr_entry *entry; 951 bool backup; 952 953 rcu_read_lock(); 954 entry = __lookup_addr(pernet, skc); 955 backup = entry && !!(entry->flags & MPTCP_PM_ADDR_FLAG_BACKUP); 956 rcu_read_unlock(); 957 958 return backup; 959 } 960 961 static int mptcp_nl_add_subflow_or_signal_addr(struct net *net, 962 struct mptcp_addr_info *addr) 963 { 964 struct mptcp_sock *msk; 965 long s_slot = 0, s_num = 0; 966 967 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { 968 struct sock *sk = (struct sock *)msk; 969 struct mptcp_addr_info mpc_addr; 970 971 if (!READ_ONCE(msk->fully_established) || 972 mptcp_pm_is_userspace(msk)) 973 goto next; 974 975 /* if the endp linked to the init sf is re-added with a != ID */ 976 mptcp_local_address((struct sock_common *)msk, &mpc_addr); 977 978 lock_sock(sk); 979 spin_lock_bh(&msk->pm.lock); 980 if (mptcp_addresses_equal(addr, &mpc_addr, addr->port)) 981 msk->mpc_endpoint_id = addr->id; 982 mptcp_pm_create_subflow_or_signal_addr(msk); 983 spin_unlock_bh(&msk->pm.lock); 984 release_sock(sk); 985 986 next: 987 sock_put(sk); 988 cond_resched(); 989 } 990 991 return 0; 992 } 993 994 /* Add an MPTCP endpoint */ 995 int mptcp_pm_nl_add_addr_doit(struct sk_buff *skb, struct genl_info *info) 996 { 997 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 998 struct mptcp_pm_addr_entry addr, *entry; 999 struct nlattr *attr; 1000 int ret; 1001 1002 if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR)) 1003 return -EINVAL; 1004 1005 attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR]; 1006 ret = mptcp_pm_parse_entry(attr, info, true, &addr); 1007 if (ret < 0) 1008 return ret; 1009 1010 if (addr.addr.port && !address_use_port(&addr)) { 1011 NL_SET_ERR_MSG_ATTR(info->extack, attr, 1012 "flags must have signal and not subflow when using port"); 1013 return -EINVAL; 1014 } 1015 1016 if (addr.flags & MPTCP_PM_ADDR_FLAG_SIGNAL && 1017 addr.flags & MPTCP_PM_ADDR_FLAG_FULLMESH) { 1018 NL_SET_ERR_MSG_ATTR(info->extack, attr, 1019 "flags mustn't have both signal and fullmesh"); 1020 return -EINVAL; 1021 } 1022 1023 if (addr.flags & MPTCP_PM_ADDR_FLAG_IMPLICIT) { 1024 NL_SET_ERR_MSG_ATTR(info->extack, attr, 1025 "can't create IMPLICIT endpoint"); 1026 return -EINVAL; 1027 } 1028 1029 entry = kmemdup(&addr, sizeof(addr), GFP_KERNEL_ACCOUNT); 1030 if (!entry) { 1031 GENL_SET_ERR_MSG(info, "can't allocate addr"); 1032 return -ENOMEM; 1033 } 1034 1035 if (entry->addr.port) { 1036 ret = mptcp_pm_nl_create_listen_socket(skb->sk, entry); 1037 if (ret) { 1038 GENL_SET_ERR_MSG_FMT(info, "create listen socket error: %d", ret); 1039 goto out_free; 1040 } 1041 } 1042 ret = mptcp_pm_nl_append_new_local_addr(pernet, entry, true); 1043 if (ret < 0) { 1044 GENL_SET_ERR_MSG_FMT(info, "too many addresses or duplicate one: %d", ret); 1045 goto out_free; 1046 } 1047 1048 mptcp_nl_add_subflow_or_signal_addr(sock_net(skb->sk), &entry->addr); 1049 return 0; 1050 1051 out_free: 1052 __mptcp_pm_release_addr_entry(entry); 1053 return ret; 1054 } 1055 1056 static void mptcp_pm_remove_announced(struct mptcp_sock *msk, 1057 const struct mptcp_addr_info *addr, 1058 bool force) 1059 { 1060 struct mptcp_rm_list list = { .nr = 0 }; 1061 bool announced; 1062 1063 list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr); 1064 1065 announced = mptcp_pm_announced_remove(msk, addr); 1066 if (announced || force) { 1067 spin_lock_bh(&msk->pm.lock); 1068 if (announced) 1069 msk->pm.add_addr_signaled--; 1070 mptcp_pm_remove_addr(msk, &list); 1071 spin_unlock_bh(&msk->pm.lock); 1072 } 1073 } 1074 1075 static void __mark_subflow_endp_available(struct mptcp_sock *msk, u8 id) 1076 { 1077 /* If it was marked as used, and not ID 0, decrement local_addr_used */ 1078 if (!__test_and_set_bit(id ? : msk->mpc_endpoint_id, msk->pm.id_avail_bitmap) && 1079 id && !WARN_ON_ONCE(msk->pm.local_addr_used == 0)) 1080 msk->pm.local_addr_used--; 1081 } 1082 1083 static int mptcp_nl_remove_subflow_and_signal_addr(struct net *net, 1084 const struct mptcp_pm_addr_entry *entry) 1085 { 1086 const struct mptcp_addr_info *addr = &entry->addr; 1087 struct mptcp_rm_list list = { .nr = 1 }; 1088 long s_slot = 0, s_num = 0; 1089 struct mptcp_sock *msk; 1090 1091 pr_debug("remove_id=%d\n", addr->id); 1092 1093 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { 1094 struct sock *sk = (struct sock *)msk; 1095 bool remove_subflow; 1096 1097 if (mptcp_pm_is_userspace(msk)) 1098 goto next; 1099 1100 lock_sock(sk); 1101 remove_subflow = mptcp_pm_has_subflow_saddr(msk, addr); 1102 mptcp_pm_remove_announced(msk, addr, remove_subflow && 1103 !(entry->flags & MPTCP_PM_ADDR_FLAG_IMPLICIT)); 1104 1105 list.ids[0] = mptcp_endp_get_local_id(msk, addr); 1106 1107 spin_lock_bh(&msk->pm.lock); 1108 if (remove_subflow) 1109 mptcp_pm_rm_subflow(msk, &list); 1110 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) 1111 __mark_subflow_endp_available(msk, list.ids[0]); 1112 else /* mark endp ID as available, e.g. Signal or MPC endp */ 1113 __set_bit(addr->id, msk->pm.id_avail_bitmap); 1114 spin_unlock_bh(&msk->pm.lock); 1115 1116 if (msk->mpc_endpoint_id == entry->addr.id) 1117 msk->mpc_endpoint_id = 0; 1118 release_sock(sk); 1119 1120 next: 1121 sock_put(sk); 1122 cond_resched(); 1123 } 1124 1125 return 0; 1126 } 1127 1128 static int mptcp_nl_remove_id_zero_address(struct net *net, 1129 struct mptcp_addr_info *addr) 1130 { 1131 struct mptcp_rm_list list = { .nr = 0 }; 1132 long s_slot = 0, s_num = 0; 1133 struct mptcp_sock *msk; 1134 1135 list.ids[list.nr++] = 0; 1136 1137 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { 1138 struct sock *sk = (struct sock *)msk; 1139 struct mptcp_addr_info msk_local; 1140 1141 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk)) 1142 goto next; 1143 1144 mptcp_local_address((struct sock_common *)msk, &msk_local); 1145 if (!mptcp_addresses_equal(&msk_local, addr, addr->port)) 1146 goto next; 1147 1148 lock_sock(sk); 1149 spin_lock_bh(&msk->pm.lock); 1150 mptcp_pm_remove_addr(msk, &list); 1151 mptcp_pm_rm_subflow(msk, &list); 1152 __mark_subflow_endp_available(msk, 0); 1153 spin_unlock_bh(&msk->pm.lock); 1154 release_sock(sk); 1155 1156 next: 1157 sock_put(sk); 1158 cond_resched(); 1159 } 1160 1161 return 0; 1162 } 1163 1164 /* Remove an MPTCP endpoint */ 1165 int mptcp_pm_nl_del_addr_doit(struct sk_buff *skb, struct genl_info *info) 1166 { 1167 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1168 struct mptcp_pm_addr_entry addr, *entry; 1169 struct nlattr *attr; 1170 u8 addr_max; 1171 int ret; 1172 1173 if (GENL_REQ_ATTR_CHECK(info, MPTCP_PM_ENDPOINT_ADDR)) 1174 return -EINVAL; 1175 1176 attr = info->attrs[MPTCP_PM_ENDPOINT_ADDR]; 1177 ret = mptcp_pm_parse_entry(attr, info, false, &addr); 1178 if (ret < 0) 1179 return ret; 1180 1181 /* the zero id address is special: the first address used by the msk 1182 * always gets such an id, so different subflows can have different zero 1183 * id addresses. Additionally zero id is not accounted for in id_bitmap. 1184 * Let's use an 'mptcp_rm_list' instead of the common remove code. 1185 */ 1186 if (addr.addr.id == 0) 1187 return mptcp_nl_remove_id_zero_address(sock_net(skb->sk), &addr.addr); 1188 1189 spin_lock_bh(&pernet->lock); 1190 entry = __lookup_addr_by_id(pernet, addr.addr.id); 1191 if (!entry) { 1192 NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found"); 1193 spin_unlock_bh(&pernet->lock); 1194 return -EINVAL; 1195 } 1196 if (entry->flags & MPTCP_PM_ADDR_FLAG_SIGNAL) { 1197 addr_max = pernet->endp_signal_max; 1198 WRITE_ONCE(pernet->endp_signal_max, addr_max - 1); 1199 } 1200 if (entry->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW) { 1201 addr_max = pernet->endp_subflow_max; 1202 WRITE_ONCE(pernet->endp_subflow_max, addr_max - 1); 1203 } 1204 if (entry->flags & MPTCP_PM_ADDR_FLAG_LAMINAR) { 1205 addr_max = pernet->endp_laminar_max; 1206 WRITE_ONCE(pernet->endp_laminar_max, addr_max - 1); 1207 } 1208 if (entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) { 1209 addr_max = pernet->endp_fullmesh_max; 1210 WRITE_ONCE(pernet->endp_fullmesh_max, addr_max - 1); 1211 } 1212 1213 pernet->endpoints--; 1214 list_del_rcu(&entry->list); 1215 __clear_bit(entry->addr.id, pernet->id_bitmap); 1216 spin_unlock_bh(&pernet->lock); 1217 1218 mptcp_nl_remove_subflow_and_signal_addr(sock_net(skb->sk), entry); 1219 synchronize_rcu(); 1220 __mptcp_pm_release_addr_entry(entry); 1221 1222 return ret; 1223 } 1224 1225 static void mptcp_pm_flush_addrs_and_subflows(struct mptcp_sock *msk, 1226 struct list_head *rm_list, 1227 struct mptcp_pm_addr_entry *entry) 1228 { 1229 struct mptcp_rm_list alist, slist; 1230 bool more; 1231 1232 again: 1233 alist.nr = 0; 1234 slist.nr = 0; 1235 more = false; 1236 1237 entry = list_prepare_entry(entry, rm_list, list); 1238 list_for_each_entry_continue(entry, rm_list, list) { 1239 if (mptcp_pm_has_subflow_saddr(msk, &entry->addr)) 1240 slist.ids[slist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr); 1241 1242 if (mptcp_pm_announced_remove(msk, &entry->addr)) 1243 alist.ids[alist.nr++] = mptcp_endp_get_local_id(msk, &entry->addr); 1244 1245 if (slist.nr == MPTCP_RM_IDS_MAX || 1246 alist.nr == MPTCP_RM_IDS_MAX) { 1247 more = !list_is_last(&entry->list, rm_list); 1248 break; 1249 } 1250 } 1251 1252 spin_lock_bh(&msk->pm.lock); 1253 if (alist.nr) { 1254 msk->pm.add_addr_signaled -= alist.nr; 1255 mptcp_pm_remove_addr(msk, &alist); 1256 } 1257 if (slist.nr) 1258 mptcp_pm_rm_subflow(msk, &slist); 1259 /* Reset counters: maybe some subflows have been removed before */ 1260 if (!more) { 1261 bitmap_fill(msk->pm.id_avail_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); 1262 msk->pm.local_addr_used = 0; 1263 } 1264 spin_unlock_bh(&msk->pm.lock); 1265 1266 if (more) 1267 goto again; 1268 } 1269 1270 static void mptcp_nl_flush_addrs_list(struct net *net, 1271 struct list_head *rm_list) 1272 { 1273 long s_slot = 0, s_num = 0; 1274 struct mptcp_sock *msk; 1275 1276 if (list_empty(rm_list)) 1277 return; 1278 1279 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { 1280 struct sock *sk = (struct sock *)msk; 1281 1282 if (!mptcp_pm_is_userspace(msk)) { 1283 lock_sock(sk); 1284 mptcp_pm_flush_addrs_and_subflows(msk, rm_list, NULL); 1285 release_sock(sk); 1286 } 1287 1288 sock_put(sk); 1289 cond_resched(); 1290 } 1291 } 1292 1293 /* caller must ensure the RCU grace period is already elapsed */ 1294 static void __flush_addrs(struct list_head *list) 1295 { 1296 while (!list_empty(list)) { 1297 struct mptcp_pm_addr_entry *cur; 1298 1299 cur = list_entry(list->next, 1300 struct mptcp_pm_addr_entry, list); 1301 list_del_rcu(&cur->list); 1302 __mptcp_pm_release_addr_entry(cur); 1303 } 1304 } 1305 1306 static void __reset_counters(struct pm_nl_pernet *pernet) 1307 { 1308 WRITE_ONCE(pernet->endp_signal_max, 0); 1309 WRITE_ONCE(pernet->endp_subflow_max, 0); 1310 WRITE_ONCE(pernet->endp_laminar_max, 0); 1311 WRITE_ONCE(pernet->endp_fullmesh_max, 0); 1312 pernet->endpoints = 0; 1313 } 1314 1315 int mptcp_pm_nl_flush_addrs_doit(struct sk_buff *skb, struct genl_info *info) 1316 { 1317 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1318 struct list_head free_list; 1319 1320 spin_lock_bh(&pernet->lock); 1321 free_list = pernet->endp_list; 1322 INIT_LIST_HEAD_RCU(&pernet->endp_list); 1323 __reset_counters(pernet); 1324 pernet->next_id = 1; 1325 bitmap_zero(pernet->id_bitmap, MPTCP_PM_MAX_ADDR_ID + 1); 1326 spin_unlock_bh(&pernet->lock); 1327 1328 if (free_list.next == &pernet->endp_list) 1329 return 0; 1330 1331 synchronize_rcu(); 1332 1333 /* Adjust the pointers to free_list instead of pernet->endp_list */ 1334 free_list.prev->next = &free_list; 1335 free_list.next->prev = &free_list; 1336 1337 mptcp_nl_flush_addrs_list(sock_net(skb->sk), &free_list); 1338 __flush_addrs(&free_list); 1339 return 0; 1340 } 1341 1342 int mptcp_pm_nl_get_addr(u8 id, struct mptcp_pm_addr_entry *addr, 1343 struct genl_info *info) 1344 { 1345 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1346 struct mptcp_pm_addr_entry *entry; 1347 int ret = -EINVAL; 1348 1349 rcu_read_lock(); 1350 entry = __lookup_addr_by_id(pernet, id); 1351 if (entry) { 1352 *addr = *entry; 1353 ret = 0; 1354 } 1355 rcu_read_unlock(); 1356 1357 return ret; 1358 } 1359 1360 int mptcp_pm_nl_dump_addr(struct sk_buff *msg, 1361 struct netlink_callback *cb) 1362 { 1363 struct net *net = sock_net(msg->sk); 1364 struct mptcp_pm_addr_entry *entry; 1365 struct pm_nl_pernet *pernet; 1366 int id = cb->args[0]; 1367 int i; 1368 1369 pernet = pm_nl_get_pernet(net); 1370 1371 rcu_read_lock(); 1372 for (i = id; i < MPTCP_PM_MAX_ADDR_ID + 1; i++) { 1373 if (test_bit(i, pernet->id_bitmap)) { 1374 entry = __lookup_addr_by_id(pernet, i); 1375 if (!entry) 1376 break; 1377 1378 if (entry->addr.id <= id) 1379 continue; 1380 1381 if (mptcp_pm_genl_fill_addr(msg, cb, entry) < 0) 1382 break; 1383 1384 id = entry->addr.id; 1385 } 1386 } 1387 rcu_read_unlock(); 1388 1389 cb->args[0] = id; 1390 return msg->len; 1391 } 1392 1393 static int parse_limit(struct genl_info *info, int id, unsigned int *limit) 1394 { 1395 struct nlattr *attr = info->attrs[id]; 1396 1397 if (!attr) 1398 return 0; 1399 1400 *limit = nla_get_u32(attr); 1401 if (*limit > MPTCP_PM_SUBFLOWS_MAX) { 1402 NL_SET_ERR_MSG_ATTR_FMT(info->extack, attr, 1403 "limit greater than maximum (%u)", 1404 MPTCP_PM_SUBFLOWS_MAX); 1405 return -EINVAL; 1406 } 1407 return 0; 1408 } 1409 1410 int mptcp_pm_nl_set_limits_doit(struct sk_buff *skb, struct genl_info *info) 1411 { 1412 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1413 unsigned int rcv_addrs, subflows; 1414 int ret; 1415 1416 spin_lock_bh(&pernet->lock); 1417 rcv_addrs = pernet->limit_add_addr_accepted; 1418 ret = parse_limit(info, MPTCP_PM_ATTR_RCV_ADD_ADDRS, &rcv_addrs); 1419 if (ret) 1420 goto unlock; 1421 1422 subflows = pernet->limit_extra_subflows; 1423 ret = parse_limit(info, MPTCP_PM_ATTR_SUBFLOWS, &subflows); 1424 if (ret) 1425 goto unlock; 1426 1427 WRITE_ONCE(pernet->limit_add_addr_accepted, rcv_addrs); 1428 WRITE_ONCE(pernet->limit_extra_subflows, subflows); 1429 1430 unlock: 1431 spin_unlock_bh(&pernet->lock); 1432 return ret; 1433 } 1434 1435 int mptcp_pm_nl_get_limits_doit(struct sk_buff *skb, struct genl_info *info) 1436 { 1437 struct pm_nl_pernet *pernet = genl_info_pm_nl(info); 1438 struct sk_buff *msg; 1439 void *reply; 1440 1441 msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL); 1442 if (!msg) 1443 return -ENOMEM; 1444 1445 reply = genlmsg_put_reply(msg, info, &mptcp_genl_family, 0, 1446 MPTCP_PM_CMD_GET_LIMITS); 1447 if (!reply) 1448 goto fail; 1449 1450 if (nla_put_u32(msg, MPTCP_PM_ATTR_RCV_ADD_ADDRS, 1451 READ_ONCE(pernet->limit_add_addr_accepted))) 1452 goto fail; 1453 1454 if (nla_put_u32(msg, MPTCP_PM_ATTR_SUBFLOWS, 1455 READ_ONCE(pernet->limit_extra_subflows))) 1456 goto fail; 1457 1458 genlmsg_end(msg, reply); 1459 return genlmsg_reply(msg, info); 1460 1461 fail: 1462 GENL_SET_ERR_MSG(info, "not enough space in Netlink message"); 1463 nlmsg_free(msg); 1464 return -EMSGSIZE; 1465 } 1466 1467 static void mptcp_pm_nl_fullmesh(struct mptcp_sock *msk, 1468 struct mptcp_addr_info *addr) 1469 { 1470 struct mptcp_rm_list list = { .nr = 0 }; 1471 1472 list.ids[list.nr++] = mptcp_endp_get_local_id(msk, addr); 1473 1474 spin_lock_bh(&msk->pm.lock); 1475 mptcp_pm_rm_subflow(msk, &list); 1476 __mark_subflow_endp_available(msk, list.ids[0]); 1477 mptcp_pm_create_subflow_or_signal_addr(msk); 1478 spin_unlock_bh(&msk->pm.lock); 1479 } 1480 1481 static void mptcp_pm_nl_set_flags_all(struct net *net, 1482 struct mptcp_pm_addr_entry *local, 1483 u8 changed) 1484 { 1485 u8 is_subflow = !!(local->flags & MPTCP_PM_ADDR_FLAG_SUBFLOW); 1486 u8 bkup = !!(local->flags & MPTCP_PM_ADDR_FLAG_BACKUP); 1487 long s_slot = 0, s_num = 0; 1488 struct mptcp_sock *msk; 1489 1490 if (changed == MPTCP_PM_ADDR_FLAG_FULLMESH && !is_subflow) 1491 return; 1492 1493 while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { 1494 struct sock *sk = (struct sock *)msk; 1495 1496 if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk)) 1497 goto next; 1498 1499 lock_sock(sk); 1500 if (changed & MPTCP_PM_ADDR_FLAG_BACKUP) 1501 mptcp_pm_mp_prio_send_ack(msk, &local->addr, NULL, bkup); 1502 /* Subflows will only be recreated if the SUBFLOW flag is set */ 1503 if (is_subflow && (changed & MPTCP_PM_ADDR_FLAG_FULLMESH)) 1504 mptcp_pm_nl_fullmesh(msk, &local->addr); 1505 release_sock(sk); 1506 1507 next: 1508 sock_put(sk); 1509 cond_resched(); 1510 } 1511 } 1512 1513 int mptcp_pm_nl_set_flags(struct mptcp_pm_addr_entry *local, 1514 struct genl_info *info) 1515 { 1516 struct nlattr *attr = info->attrs[MPTCP_PM_ATTR_ADDR]; 1517 u8 changed, mask = MPTCP_PM_ADDR_FLAG_BACKUP | 1518 MPTCP_PM_ADDR_FLAG_FULLMESH; 1519 struct net *net = genl_info_net(info); 1520 struct mptcp_pm_addr_entry *entry; 1521 struct pm_nl_pernet *pernet; 1522 u8 lookup_by_id = 0; 1523 1524 pernet = pm_nl_get_pernet(net); 1525 1526 if (local->addr.family == AF_UNSPEC) { 1527 lookup_by_id = 1; 1528 if (!local->addr.id) { 1529 NL_SET_ERR_MSG_ATTR(info->extack, attr, 1530 "missing address ID"); 1531 return -EOPNOTSUPP; 1532 } 1533 } 1534 1535 spin_lock_bh(&pernet->lock); 1536 entry = lookup_by_id ? __lookup_addr_by_id(pernet, local->addr.id) : 1537 __lookup_addr(pernet, &local->addr); 1538 if (!entry) { 1539 spin_unlock_bh(&pernet->lock); 1540 NL_SET_ERR_MSG_ATTR(info->extack, attr, "address not found"); 1541 return -EINVAL; 1542 } 1543 if ((local->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) && 1544 (entry->flags & (MPTCP_PM_ADDR_FLAG_SIGNAL | 1545 MPTCP_PM_ADDR_FLAG_IMPLICIT))) { 1546 spin_unlock_bh(&pernet->lock); 1547 NL_SET_ERR_MSG_ATTR(info->extack, attr, "invalid addr flags"); 1548 return -EINVAL; 1549 } 1550 1551 changed = (local->flags ^ entry->flags) & mask; 1552 entry->flags = (entry->flags & ~mask) | (local->flags & mask); 1553 *local = *entry; 1554 1555 if (changed & MPTCP_PM_ADDR_FLAG_FULLMESH) { 1556 u8 addr_max = pernet->endp_fullmesh_max; 1557 1558 if (entry->flags & MPTCP_PM_ADDR_FLAG_FULLMESH) 1559 addr_max++; 1560 else 1561 addr_max--; 1562 1563 WRITE_ONCE(pernet->endp_fullmesh_max, addr_max); 1564 } 1565 1566 spin_unlock_bh(&pernet->lock); 1567 1568 mptcp_pm_nl_set_flags_all(net, local, changed); 1569 return 0; 1570 } 1571 1572 bool mptcp_pm_nl_check_work_pending(struct mptcp_sock *msk) 1573 { 1574 struct pm_nl_pernet *pernet = pm_nl_get_pernet_from_msk(msk); 1575 1576 if (msk->pm.extra_subflows == mptcp_pm_get_limit_extra_subflows(msk) || 1577 (find_next_and_bit(pernet->id_bitmap, msk->pm.id_avail_bitmap, 1578 MPTCP_PM_MAX_ADDR_ID + 1, 0) == MPTCP_PM_MAX_ADDR_ID + 1)) { 1579 WRITE_ONCE(msk->pm.work_pending, false); 1580 return false; 1581 } 1582 return true; 1583 } 1584 1585 /* Called under PM lock */ 1586 void __mptcp_pm_kernel_worker(struct mptcp_sock *msk) 1587 { 1588 struct mptcp_pm_data *pm = &msk->pm; 1589 1590 if (pm->status & BIT(MPTCP_PM_ADD_ADDR_RECEIVED)) { 1591 pm->status &= ~BIT(MPTCP_PM_ADD_ADDR_RECEIVED); 1592 mptcp_pm_nl_add_addr_received(msk); 1593 } 1594 if (pm->status & BIT(MPTCP_PM_ESTABLISHED)) { 1595 pm->status &= ~BIT(MPTCP_PM_ESTABLISHED); 1596 mptcp_pm_nl_fully_established(msk); 1597 } 1598 if (pm->status & BIT(MPTCP_PM_SUBFLOW_ESTABLISHED)) { 1599 pm->status &= ~BIT(MPTCP_PM_SUBFLOW_ESTABLISHED); 1600 mptcp_pm_nl_subflow_established(msk); 1601 } 1602 } 1603 1604 static int __net_init pm_nl_init_net(struct net *net) 1605 { 1606 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net); 1607 1608 INIT_LIST_HEAD_RCU(&pernet->endp_list); 1609 1610 /* Cit. 2 subflows ought to be enough for anybody. */ 1611 pernet->limit_extra_subflows = 2; 1612 pernet->next_id = 1; 1613 spin_lock_init(&pernet->lock); 1614 1615 /* No need to initialize other pernet fields, the struct is zeroed at 1616 * allocation time. 1617 */ 1618 1619 return 0; 1620 } 1621 1622 static void __net_exit pm_nl_exit_net(struct list_head *net_list) 1623 { 1624 struct net *net; 1625 1626 list_for_each_entry(net, net_list, exit_list) { 1627 struct pm_nl_pernet *pernet = pm_nl_get_pernet(net); 1628 1629 /* net is removed from namespace list, can't race with 1630 * other modifiers, also netns core already waited for a 1631 * RCU grace period. 1632 */ 1633 __flush_addrs(&pernet->endp_list); 1634 } 1635 } 1636 1637 static struct pernet_operations mptcp_pm_pernet_ops = { 1638 .init = pm_nl_init_net, 1639 .exit_batch = pm_nl_exit_net, 1640 .id = &pm_nl_pernet_id, 1641 .size = sizeof(struct pm_nl_pernet), 1642 }; 1643 1644 struct mptcp_pm_ops mptcp_pm_kernel = { 1645 .name = "kernel", 1646 .owner = THIS_MODULE, 1647 }; 1648 1649 void __init mptcp_pm_kernel_register(void) 1650 { 1651 if (register_pernet_subsys(&mptcp_pm_pernet_ops) < 0) 1652 panic("Failed to register MPTCP PM pernet subsystem.\n"); 1653 1654 mptcp_pm_register(&mptcp_pm_kernel); 1655 } 1656