1 // SPDX-License-Identifier: GPL-2.0 2 /* Multipath TCP 3 * 4 * Copyright (c) 2021, Red Hat. 5 */ 6 7 #define pr_fmt(fmt) "MPTCP: " fmt 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <net/sock.h> 12 #include <net/protocol.h> 13 #include <net/tcp.h> 14 #include <net/mptcp.h> 15 #include "protocol.h" 16 17 #define MIN_INFO_OPTLEN_SIZE 16 18 19 static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk) 20 { 21 sock_owned_by_me((const struct sock *)msk); 22 23 if (likely(!__mptcp_check_fallback(msk))) 24 return NULL; 25 26 return msk->first; 27 } 28 29 static u32 sockopt_seq_reset(const struct sock *sk) 30 { 31 sock_owned_by_me(sk); 32 33 /* Highbits contain state. Allows to distinguish sockopt_seq 34 * of listener and established: 35 * s0 = new_listener() 36 * sockopt(s0) - seq is 1 37 * s1 = accept(s0) - s1 inherits seq 1 if listener sk (s0) 38 * sockopt(s0) - seq increments to 2 on s0 39 * sockopt(s1) // seq increments to 2 on s1 (different option) 40 * new ssk completes join, inherits options from s0 // seq 2 41 * Needs sync from mptcp join logic, but ssk->seq == msk->seq 42 * 43 * Set High order bits to sk_state so ssk->seq == msk->seq test 44 * will fail. 45 */ 46 47 return (u32)sk->sk_state << 24u; 48 } 49 50 static void sockopt_seq_inc(struct mptcp_sock *msk) 51 { 52 u32 seq = (msk->setsockopt_seq + 1) & 0x00ffffff; 53 54 msk->setsockopt_seq = sockopt_seq_reset((struct sock *)msk) + seq; 55 } 56 57 static int mptcp_get_int_option(struct mptcp_sock *msk, sockptr_t optval, 58 unsigned int optlen, int *val) 59 { 60 if (optlen < sizeof(int)) 61 return -EINVAL; 62 63 if (copy_from_sockptr(val, optval, sizeof(*val))) 64 return -EFAULT; 65 66 return 0; 67 } 68 69 static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname, int val) 70 { 71 struct mptcp_subflow_context *subflow; 72 struct sock *sk = (struct sock *)msk; 73 74 lock_sock(sk); 75 sockopt_seq_inc(msk); 76 77 mptcp_for_each_subflow(msk, subflow) { 78 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 79 bool slow = lock_sock_fast(ssk); 80 81 switch (optname) { 82 case SO_DEBUG: 83 sock_valbool_flag(ssk, SOCK_DBG, !!val); 84 break; 85 case SO_KEEPALIVE: 86 if (ssk->sk_prot->keepalive) 87 ssk->sk_prot->keepalive(ssk, !!val); 88 sock_valbool_flag(ssk, SOCK_KEEPOPEN, !!val); 89 break; 90 case SO_PRIORITY: 91 ssk->sk_priority = val; 92 break; 93 case SO_SNDBUF: 94 case SO_SNDBUFFORCE: 95 ssk->sk_userlocks |= SOCK_SNDBUF_LOCK; 96 WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf); 97 break; 98 case SO_RCVBUF: 99 case SO_RCVBUFFORCE: 100 ssk->sk_userlocks |= SOCK_RCVBUF_LOCK; 101 WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); 102 break; 103 case SO_MARK: 104 if (READ_ONCE(ssk->sk_mark) != sk->sk_mark) { 105 ssk->sk_mark = sk->sk_mark; 106 sk_dst_reset(ssk); 107 } 108 break; 109 case SO_INCOMING_CPU: 110 WRITE_ONCE(ssk->sk_incoming_cpu, val); 111 break; 112 } 113 114 subflow->setsockopt_seq = msk->setsockopt_seq; 115 unlock_sock_fast(ssk, slow); 116 } 117 118 release_sock(sk); 119 } 120 121 static int mptcp_sol_socket_intval(struct mptcp_sock *msk, int optname, int val) 122 { 123 sockptr_t optval = KERNEL_SOCKPTR(&val); 124 struct sock *sk = (struct sock *)msk; 125 int ret; 126 127 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, 128 optval, sizeof(val)); 129 if (ret) 130 return ret; 131 132 mptcp_sol_socket_sync_intval(msk, optname, val); 133 return 0; 134 } 135 136 static void mptcp_so_incoming_cpu(struct mptcp_sock *msk, int val) 137 { 138 struct sock *sk = (struct sock *)msk; 139 140 WRITE_ONCE(sk->sk_incoming_cpu, val); 141 142 mptcp_sol_socket_sync_intval(msk, SO_INCOMING_CPU, val); 143 } 144 145 static int mptcp_setsockopt_sol_socket_tstamp(struct mptcp_sock *msk, int optname, int val) 146 { 147 sockptr_t optval = KERNEL_SOCKPTR(&val); 148 struct mptcp_subflow_context *subflow; 149 struct sock *sk = (struct sock *)msk; 150 int ret; 151 152 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, 153 optval, sizeof(val)); 154 if (ret) 155 return ret; 156 157 lock_sock(sk); 158 mptcp_for_each_subflow(msk, subflow) { 159 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 160 bool slow = lock_sock_fast(ssk); 161 162 sock_set_timestamp(sk, optname, !!val); 163 unlock_sock_fast(ssk, slow); 164 } 165 166 release_sock(sk); 167 return 0; 168 } 169 170 static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int optname, 171 sockptr_t optval, 172 unsigned int optlen) 173 { 174 int val, ret; 175 176 ret = mptcp_get_int_option(msk, optval, optlen, &val); 177 if (ret) 178 return ret; 179 180 switch (optname) { 181 case SO_KEEPALIVE: 182 mptcp_sol_socket_sync_intval(msk, optname, val); 183 return 0; 184 case SO_DEBUG: 185 case SO_MARK: 186 case SO_PRIORITY: 187 case SO_SNDBUF: 188 case SO_SNDBUFFORCE: 189 case SO_RCVBUF: 190 case SO_RCVBUFFORCE: 191 return mptcp_sol_socket_intval(msk, optname, val); 192 case SO_INCOMING_CPU: 193 mptcp_so_incoming_cpu(msk, val); 194 return 0; 195 case SO_TIMESTAMP_OLD: 196 case SO_TIMESTAMP_NEW: 197 case SO_TIMESTAMPNS_OLD: 198 case SO_TIMESTAMPNS_NEW: 199 return mptcp_setsockopt_sol_socket_tstamp(msk, optname, val); 200 } 201 202 return -ENOPROTOOPT; 203 } 204 205 static int mptcp_setsockopt_sol_socket_timestamping(struct mptcp_sock *msk, 206 int optname, 207 sockptr_t optval, 208 unsigned int optlen) 209 { 210 struct mptcp_subflow_context *subflow; 211 struct sock *sk = (struct sock *)msk; 212 struct so_timestamping timestamping; 213 int ret; 214 215 if (optlen == sizeof(timestamping)) { 216 if (copy_from_sockptr(×tamping, optval, 217 sizeof(timestamping))) 218 return -EFAULT; 219 } else if (optlen == sizeof(int)) { 220 memset(×tamping, 0, sizeof(timestamping)); 221 222 if (copy_from_sockptr(×tamping.flags, optval, sizeof(int))) 223 return -EFAULT; 224 } else { 225 return -EINVAL; 226 } 227 228 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, 229 KERNEL_SOCKPTR(×tamping), 230 sizeof(timestamping)); 231 if (ret) 232 return ret; 233 234 lock_sock(sk); 235 236 mptcp_for_each_subflow(msk, subflow) { 237 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 238 bool slow = lock_sock_fast(ssk); 239 240 sock_set_timestamping(sk, optname, timestamping); 241 unlock_sock_fast(ssk, slow); 242 } 243 244 release_sock(sk); 245 246 return 0; 247 } 248 249 static int mptcp_setsockopt_sol_socket_linger(struct mptcp_sock *msk, sockptr_t optval, 250 unsigned int optlen) 251 { 252 struct mptcp_subflow_context *subflow; 253 struct sock *sk = (struct sock *)msk; 254 struct linger ling; 255 sockptr_t kopt; 256 int ret; 257 258 if (optlen < sizeof(ling)) 259 return -EINVAL; 260 261 if (copy_from_sockptr(&ling, optval, sizeof(ling))) 262 return -EFAULT; 263 264 kopt = KERNEL_SOCKPTR(&ling); 265 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, SO_LINGER, kopt, sizeof(ling)); 266 if (ret) 267 return ret; 268 269 lock_sock(sk); 270 sockopt_seq_inc(msk); 271 mptcp_for_each_subflow(msk, subflow) { 272 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 273 bool slow = lock_sock_fast(ssk); 274 275 if (!ling.l_onoff) { 276 sock_reset_flag(ssk, SOCK_LINGER); 277 } else { 278 ssk->sk_lingertime = sk->sk_lingertime; 279 sock_set_flag(ssk, SOCK_LINGER); 280 } 281 282 subflow->setsockopt_seq = msk->setsockopt_seq; 283 unlock_sock_fast(ssk, slow); 284 } 285 286 release_sock(sk); 287 return 0; 288 } 289 290 static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, 291 sockptr_t optval, unsigned int optlen) 292 { 293 struct sock *sk = (struct sock *)msk; 294 struct socket *ssock; 295 int ret; 296 297 switch (optname) { 298 case SO_REUSEPORT: 299 case SO_REUSEADDR: 300 case SO_BINDTODEVICE: 301 case SO_BINDTOIFINDEX: 302 lock_sock(sk); 303 ssock = __mptcp_nmpc_socket(msk); 304 if (!ssock) { 305 release_sock(sk); 306 return -EINVAL; 307 } 308 309 ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen); 310 if (ret == 0) { 311 if (optname == SO_REUSEPORT) 312 sk->sk_reuseport = ssock->sk->sk_reuseport; 313 else if (optname == SO_REUSEADDR) 314 sk->sk_reuse = ssock->sk->sk_reuse; 315 else if (optname == SO_BINDTODEVICE) 316 sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if; 317 else if (optname == SO_BINDTOIFINDEX) 318 sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if; 319 } 320 release_sock(sk); 321 return ret; 322 case SO_KEEPALIVE: 323 case SO_PRIORITY: 324 case SO_SNDBUF: 325 case SO_SNDBUFFORCE: 326 case SO_RCVBUF: 327 case SO_RCVBUFFORCE: 328 case SO_MARK: 329 case SO_INCOMING_CPU: 330 case SO_DEBUG: 331 case SO_TIMESTAMP_OLD: 332 case SO_TIMESTAMP_NEW: 333 case SO_TIMESTAMPNS_OLD: 334 case SO_TIMESTAMPNS_NEW: 335 return mptcp_setsockopt_sol_socket_int(msk, optname, optval, 336 optlen); 337 case SO_TIMESTAMPING_OLD: 338 case SO_TIMESTAMPING_NEW: 339 return mptcp_setsockopt_sol_socket_timestamping(msk, optname, 340 optval, optlen); 341 case SO_LINGER: 342 return mptcp_setsockopt_sol_socket_linger(msk, optval, optlen); 343 case SO_RCVLOWAT: 344 case SO_RCVTIMEO_OLD: 345 case SO_RCVTIMEO_NEW: 346 case SO_SNDTIMEO_OLD: 347 case SO_SNDTIMEO_NEW: 348 case SO_BUSY_POLL: 349 case SO_PREFER_BUSY_POLL: 350 case SO_BUSY_POLL_BUDGET: 351 /* No need to copy: only relevant for msk */ 352 return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen); 353 case SO_NO_CHECK: 354 case SO_DONTROUTE: 355 case SO_BROADCAST: 356 case SO_BSDCOMPAT: 357 case SO_PASSCRED: 358 case SO_PASSSEC: 359 case SO_RXQ_OVFL: 360 case SO_WIFI_STATUS: 361 case SO_NOFCS: 362 case SO_SELECT_ERR_QUEUE: 363 return 0; 364 } 365 366 /* SO_OOBINLINE is not supported, let's avoid the related mess 367 * SO_ATTACH_FILTER, SO_ATTACH_BPF, SO_ATTACH_REUSEPORT_CBPF, 368 * SO_DETACH_REUSEPORT_BPF, SO_DETACH_FILTER, SO_LOCK_FILTER, 369 * we must be careful with subflows 370 * 371 * SO_ATTACH_REUSEPORT_EBPF is not supported, at it checks 372 * explicitly the sk_protocol field 373 * 374 * SO_PEEK_OFF is unsupported, as it is for plain TCP 375 * SO_MAX_PACING_RATE is unsupported, we must be careful with subflows 376 * SO_CNX_ADVICE is currently unsupported, could possibly be relevant, 377 * but likely needs careful design 378 * 379 * SO_ZEROCOPY is currently unsupported, TODO in sndmsg 380 * SO_TXTIME is currently unsupported 381 */ 382 383 return -EOPNOTSUPP; 384 } 385 386 static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname, 387 sockptr_t optval, unsigned int optlen) 388 { 389 struct sock *sk = (struct sock *)msk; 390 int ret = -EOPNOTSUPP; 391 struct socket *ssock; 392 393 switch (optname) { 394 case IPV6_V6ONLY: 395 case IPV6_TRANSPARENT: 396 case IPV6_FREEBIND: 397 lock_sock(sk); 398 ssock = __mptcp_nmpc_socket(msk); 399 if (!ssock) { 400 release_sock(sk); 401 return -EINVAL; 402 } 403 404 ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen); 405 if (ret != 0) { 406 release_sock(sk); 407 return ret; 408 } 409 410 sockopt_seq_inc(msk); 411 412 switch (optname) { 413 case IPV6_V6ONLY: 414 sk->sk_ipv6only = ssock->sk->sk_ipv6only; 415 break; 416 case IPV6_TRANSPARENT: 417 inet_sk(sk)->transparent = inet_sk(ssock->sk)->transparent; 418 break; 419 case IPV6_FREEBIND: 420 inet_sk(sk)->freebind = inet_sk(ssock->sk)->freebind; 421 break; 422 } 423 424 release_sock(sk); 425 break; 426 } 427 428 return ret; 429 } 430 431 static bool mptcp_supported_sockopt(int level, int optname) 432 { 433 if (level == SOL_IP) { 434 switch (optname) { 435 /* should work fine */ 436 case IP_FREEBIND: 437 case IP_TRANSPARENT: 438 439 /* the following are control cmsg related */ 440 case IP_PKTINFO: 441 case IP_RECVTTL: 442 case IP_RECVTOS: 443 case IP_RECVOPTS: 444 case IP_RETOPTS: 445 case IP_PASSSEC: 446 case IP_RECVORIGDSTADDR: 447 case IP_CHECKSUM: 448 case IP_RECVFRAGSIZE: 449 450 /* common stuff that need some love */ 451 case IP_TOS: 452 case IP_TTL: 453 case IP_BIND_ADDRESS_NO_PORT: 454 case IP_MTU_DISCOVER: 455 case IP_RECVERR: 456 457 /* possibly less common may deserve some love */ 458 case IP_MINTTL: 459 460 /* the following is apparently a no-op for plain TCP */ 461 case IP_RECVERR_RFC4884: 462 return true; 463 } 464 465 /* IP_OPTIONS is not supported, needs subflow care */ 466 /* IP_HDRINCL, IP_NODEFRAG are not supported, RAW specific */ 467 /* IP_MULTICAST_TTL, IP_MULTICAST_LOOP, IP_UNICAST_IF, 468 * IP_ADD_MEMBERSHIP, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP, 469 * IP_DROP_SOURCE_MEMBERSHIP, IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE, 470 * MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP MCAST_JOIN_SOURCE_GROUP, 471 * MCAST_LEAVE_SOURCE_GROUP, MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, 472 * MCAST_MSFILTER, IP_MULTICAST_ALL are not supported, better not deal 473 * with mcast stuff 474 */ 475 /* IP_IPSEC_POLICY, IP_XFRM_POLICY are nut supported, unrelated here */ 476 return false; 477 } 478 if (level == SOL_IPV6) { 479 switch (optname) { 480 case IPV6_V6ONLY: 481 482 /* the following are control cmsg related */ 483 case IPV6_RECVPKTINFO: 484 case IPV6_2292PKTINFO: 485 case IPV6_RECVHOPLIMIT: 486 case IPV6_2292HOPLIMIT: 487 case IPV6_RECVRTHDR: 488 case IPV6_2292RTHDR: 489 case IPV6_RECVHOPOPTS: 490 case IPV6_2292HOPOPTS: 491 case IPV6_RECVDSTOPTS: 492 case IPV6_2292DSTOPTS: 493 case IPV6_RECVTCLASS: 494 case IPV6_FLOWINFO: 495 case IPV6_RECVPATHMTU: 496 case IPV6_RECVORIGDSTADDR: 497 case IPV6_RECVFRAGSIZE: 498 499 /* the following ones need some love but are quite common */ 500 case IPV6_TCLASS: 501 case IPV6_TRANSPARENT: 502 case IPV6_FREEBIND: 503 case IPV6_PKTINFO: 504 case IPV6_2292PKTOPTIONS: 505 case IPV6_UNICAST_HOPS: 506 case IPV6_MTU_DISCOVER: 507 case IPV6_MTU: 508 case IPV6_RECVERR: 509 case IPV6_FLOWINFO_SEND: 510 case IPV6_FLOWLABEL_MGR: 511 case IPV6_MINHOPCOUNT: 512 case IPV6_DONTFRAG: 513 case IPV6_AUTOFLOWLABEL: 514 515 /* the following one is a no-op for plain TCP */ 516 case IPV6_RECVERR_RFC4884: 517 return true; 518 } 519 520 /* IPV6_HOPOPTS, IPV6_RTHDRDSTOPTS, IPV6_RTHDR, IPV6_DSTOPTS are 521 * not supported 522 */ 523 /* IPV6_MULTICAST_HOPS, IPV6_MULTICAST_LOOP, IPV6_UNICAST_IF, 524 * IPV6_MULTICAST_IF, IPV6_ADDRFORM, 525 * IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST, 526 * IPV6_LEAVE_ANYCAST, IPV6_MULTICAST_ALL, MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP, 527 * MCAST_JOIN_SOURCE_GROUP, MCAST_LEAVE_SOURCE_GROUP, 528 * MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, MCAST_MSFILTER 529 * are not supported better not deal with mcast 530 */ 531 /* IPV6_ROUTER_ALERT, IPV6_ROUTER_ALERT_ISOLATE are not supported, since are evil */ 532 533 /* IPV6_IPSEC_POLICY, IPV6_XFRM_POLICY are not supported */ 534 /* IPV6_ADDR_PREFERENCES is not supported, we must be careful with subflows */ 535 return false; 536 } 537 if (level == SOL_TCP) { 538 switch (optname) { 539 /* the following are no-op or should work just fine */ 540 case TCP_THIN_DUPACK: 541 case TCP_DEFER_ACCEPT: 542 543 /* the following need some love */ 544 case TCP_MAXSEG: 545 case TCP_NODELAY: 546 case TCP_THIN_LINEAR_TIMEOUTS: 547 case TCP_CONGESTION: 548 case TCP_CORK: 549 case TCP_KEEPIDLE: 550 case TCP_KEEPINTVL: 551 case TCP_KEEPCNT: 552 case TCP_SYNCNT: 553 case TCP_SAVE_SYN: 554 case TCP_LINGER2: 555 case TCP_WINDOW_CLAMP: 556 case TCP_QUICKACK: 557 case TCP_USER_TIMEOUT: 558 case TCP_TIMESTAMP: 559 case TCP_NOTSENT_LOWAT: 560 case TCP_TX_DELAY: 561 case TCP_INQ: 562 case TCP_FASTOPEN_CONNECT: 563 case TCP_FASTOPEN_NO_COOKIE: 564 return true; 565 } 566 567 /* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */ 568 569 /* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS, 570 * TCP_REPAIR_WINDOW are not supported, better avoid this mess 571 */ 572 /* TCP_FASTOPEN_KEY, TCP_FASTOPEN are not supported because 573 * fastopen for the listener side is currently unsupported 574 */ 575 } 576 return false; 577 } 578 579 static int mptcp_setsockopt_sol_tcp_congestion(struct mptcp_sock *msk, sockptr_t optval, 580 unsigned int optlen) 581 { 582 struct mptcp_subflow_context *subflow; 583 struct sock *sk = (struct sock *)msk; 584 char name[TCP_CA_NAME_MAX]; 585 bool cap_net_admin; 586 int ret; 587 588 if (optlen < 1) 589 return -EINVAL; 590 591 ret = strncpy_from_sockptr(name, optval, 592 min_t(long, TCP_CA_NAME_MAX - 1, optlen)); 593 if (ret < 0) 594 return -EFAULT; 595 596 name[ret] = 0; 597 598 cap_net_admin = ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN); 599 600 ret = 0; 601 lock_sock(sk); 602 sockopt_seq_inc(msk); 603 mptcp_for_each_subflow(msk, subflow) { 604 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 605 int err; 606 607 lock_sock(ssk); 608 err = tcp_set_congestion_control(ssk, name, true, cap_net_admin); 609 if (err < 0 && ret == 0) 610 ret = err; 611 subflow->setsockopt_seq = msk->setsockopt_seq; 612 release_sock(ssk); 613 } 614 615 if (ret == 0) 616 strcpy(msk->ca_name, name); 617 618 release_sock(sk); 619 return ret; 620 } 621 622 static int mptcp_setsockopt_sol_tcp_cork(struct mptcp_sock *msk, sockptr_t optval, 623 unsigned int optlen) 624 { 625 struct mptcp_subflow_context *subflow; 626 struct sock *sk = (struct sock *)msk; 627 int val; 628 629 if (optlen < sizeof(int)) 630 return -EINVAL; 631 632 if (copy_from_sockptr(&val, optval, sizeof(val))) 633 return -EFAULT; 634 635 lock_sock(sk); 636 sockopt_seq_inc(msk); 637 msk->cork = !!val; 638 mptcp_for_each_subflow(msk, subflow) { 639 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 640 641 lock_sock(ssk); 642 __tcp_sock_set_cork(ssk, !!val); 643 release_sock(ssk); 644 } 645 if (!val) 646 mptcp_check_and_set_pending(sk); 647 release_sock(sk); 648 649 return 0; 650 } 651 652 static int mptcp_setsockopt_sol_tcp_nodelay(struct mptcp_sock *msk, sockptr_t optval, 653 unsigned int optlen) 654 { 655 struct mptcp_subflow_context *subflow; 656 struct sock *sk = (struct sock *)msk; 657 int val; 658 659 if (optlen < sizeof(int)) 660 return -EINVAL; 661 662 if (copy_from_sockptr(&val, optval, sizeof(val))) 663 return -EFAULT; 664 665 lock_sock(sk); 666 sockopt_seq_inc(msk); 667 msk->nodelay = !!val; 668 mptcp_for_each_subflow(msk, subflow) { 669 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 670 671 lock_sock(ssk); 672 __tcp_sock_set_nodelay(ssk, !!val); 673 release_sock(ssk); 674 } 675 if (val) 676 mptcp_check_and_set_pending(sk); 677 release_sock(sk); 678 679 return 0; 680 } 681 682 static int mptcp_setsockopt_sol_ip_set_transparent(struct mptcp_sock *msk, int optname, 683 sockptr_t optval, unsigned int optlen) 684 { 685 struct sock *sk = (struct sock *)msk; 686 struct inet_sock *issk; 687 struct socket *ssock; 688 int err; 689 690 err = ip_setsockopt(sk, SOL_IP, optname, optval, optlen); 691 if (err != 0) 692 return err; 693 694 lock_sock(sk); 695 696 ssock = __mptcp_nmpc_socket(msk); 697 if (!ssock) { 698 release_sock(sk); 699 return -EINVAL; 700 } 701 702 issk = inet_sk(ssock->sk); 703 704 switch (optname) { 705 case IP_FREEBIND: 706 issk->freebind = inet_sk(sk)->freebind; 707 break; 708 case IP_TRANSPARENT: 709 issk->transparent = inet_sk(sk)->transparent; 710 break; 711 default: 712 release_sock(sk); 713 WARN_ON_ONCE(1); 714 return -EOPNOTSUPP; 715 } 716 717 sockopt_seq_inc(msk); 718 release_sock(sk); 719 return 0; 720 } 721 722 static int mptcp_setsockopt_v4_set_tos(struct mptcp_sock *msk, int optname, 723 sockptr_t optval, unsigned int optlen) 724 { 725 struct mptcp_subflow_context *subflow; 726 struct sock *sk = (struct sock *)msk; 727 int err, val; 728 729 err = ip_setsockopt(sk, SOL_IP, optname, optval, optlen); 730 731 if (err != 0) 732 return err; 733 734 lock_sock(sk); 735 sockopt_seq_inc(msk); 736 val = inet_sk(sk)->tos; 737 mptcp_for_each_subflow(msk, subflow) { 738 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 739 740 __ip_sock_set_tos(ssk, val); 741 } 742 release_sock(sk); 743 744 return err; 745 } 746 747 static int mptcp_setsockopt_v4(struct mptcp_sock *msk, int optname, 748 sockptr_t optval, unsigned int optlen) 749 { 750 switch (optname) { 751 case IP_FREEBIND: 752 case IP_TRANSPARENT: 753 return mptcp_setsockopt_sol_ip_set_transparent(msk, optname, optval, optlen); 754 case IP_TOS: 755 return mptcp_setsockopt_v4_set_tos(msk, optname, optval, optlen); 756 } 757 758 return -EOPNOTSUPP; 759 } 760 761 static int mptcp_setsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname, 762 sockptr_t optval, unsigned int optlen) 763 { 764 struct socket *sock; 765 766 /* Limit to first subflow, before the connection establishment */ 767 sock = __mptcp_nmpc_socket(msk); 768 if (!sock) 769 return -EINVAL; 770 771 return tcp_setsockopt(sock->sk, level, optname, optval, optlen); 772 } 773 774 static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 775 sockptr_t optval, unsigned int optlen) 776 { 777 struct sock *sk = (void *)msk; 778 int ret, val; 779 780 switch (optname) { 781 case TCP_INQ: 782 ret = mptcp_get_int_option(msk, optval, optlen, &val); 783 if (ret) 784 return ret; 785 if (val < 0 || val > 1) 786 return -EINVAL; 787 788 lock_sock(sk); 789 msk->recvmsg_inq = !!val; 790 release_sock(sk); 791 return 0; 792 case TCP_ULP: 793 return -EOPNOTSUPP; 794 case TCP_CONGESTION: 795 return mptcp_setsockopt_sol_tcp_congestion(msk, optval, optlen); 796 case TCP_CORK: 797 return mptcp_setsockopt_sol_tcp_cork(msk, optval, optlen); 798 case TCP_NODELAY: 799 return mptcp_setsockopt_sol_tcp_nodelay(msk, optval, optlen); 800 case TCP_DEFER_ACCEPT: 801 /* See tcp.c: TCP_DEFER_ACCEPT does not fail */ 802 mptcp_setsockopt_first_sf_only(msk, SOL_TCP, optname, optval, optlen); 803 return 0; 804 case TCP_FASTOPEN_CONNECT: 805 case TCP_FASTOPEN_NO_COOKIE: 806 return mptcp_setsockopt_first_sf_only(msk, SOL_TCP, optname, 807 optval, optlen); 808 } 809 810 return -EOPNOTSUPP; 811 } 812 813 int mptcp_setsockopt(struct sock *sk, int level, int optname, 814 sockptr_t optval, unsigned int optlen) 815 { 816 struct mptcp_sock *msk = mptcp_sk(sk); 817 struct sock *ssk; 818 819 pr_debug("msk=%p", msk); 820 821 if (level == SOL_SOCKET) 822 return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen); 823 824 if (!mptcp_supported_sockopt(level, optname)) 825 return -ENOPROTOOPT; 826 827 /* @@ the meaning of setsockopt() when the socket is connected and 828 * there are multiple subflows is not yet defined. It is up to the 829 * MPTCP-level socket to configure the subflows until the subflow 830 * is in TCP fallback, when TCP socket options are passed through 831 * to the one remaining subflow. 832 */ 833 lock_sock(sk); 834 ssk = __mptcp_tcp_fallback(msk); 835 release_sock(sk); 836 if (ssk) 837 return tcp_setsockopt(ssk, level, optname, optval, optlen); 838 839 if (level == SOL_IP) 840 return mptcp_setsockopt_v4(msk, optname, optval, optlen); 841 842 if (level == SOL_IPV6) 843 return mptcp_setsockopt_v6(msk, optname, optval, optlen); 844 845 if (level == SOL_TCP) 846 return mptcp_setsockopt_sol_tcp(msk, optname, optval, optlen); 847 848 return -EOPNOTSUPP; 849 } 850 851 static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname, 852 char __user *optval, int __user *optlen) 853 { 854 struct sock *sk = (struct sock *)msk; 855 struct socket *ssock; 856 int ret = -EINVAL; 857 struct sock *ssk; 858 859 lock_sock(sk); 860 ssk = msk->first; 861 if (ssk) { 862 ret = tcp_getsockopt(ssk, level, optname, optval, optlen); 863 goto out; 864 } 865 866 ssock = __mptcp_nmpc_socket(msk); 867 if (!ssock) 868 goto out; 869 870 ret = tcp_getsockopt(ssock->sk, level, optname, optval, optlen); 871 872 out: 873 release_sock(sk); 874 return ret; 875 } 876 877 void mptcp_diag_fill_info(struct mptcp_sock *msk, struct mptcp_info *info) 878 { 879 u32 flags = 0; 880 u8 val; 881 882 memset(info, 0, sizeof(*info)); 883 884 info->mptcpi_subflows = READ_ONCE(msk->pm.subflows); 885 info->mptcpi_add_addr_signal = READ_ONCE(msk->pm.add_addr_signaled); 886 info->mptcpi_add_addr_accepted = READ_ONCE(msk->pm.add_addr_accepted); 887 info->mptcpi_local_addr_used = READ_ONCE(msk->pm.local_addr_used); 888 info->mptcpi_subflows_max = mptcp_pm_get_subflows_max(msk); 889 val = mptcp_pm_get_add_addr_signal_max(msk); 890 info->mptcpi_add_addr_signal_max = val; 891 val = mptcp_pm_get_add_addr_accept_max(msk); 892 info->mptcpi_add_addr_accepted_max = val; 893 info->mptcpi_local_addr_max = mptcp_pm_get_local_addr_max(msk); 894 if (test_bit(MPTCP_FALLBACK_DONE, &msk->flags)) 895 flags |= MPTCP_INFO_FLAG_FALLBACK; 896 if (READ_ONCE(msk->can_ack)) 897 flags |= MPTCP_INFO_FLAG_REMOTE_KEY_RECEIVED; 898 info->mptcpi_flags = flags; 899 info->mptcpi_token = READ_ONCE(msk->token); 900 info->mptcpi_write_seq = READ_ONCE(msk->write_seq); 901 info->mptcpi_snd_una = READ_ONCE(msk->snd_una); 902 info->mptcpi_rcv_nxt = READ_ONCE(msk->ack_seq); 903 info->mptcpi_csum_enabled = READ_ONCE(msk->csum_enabled); 904 } 905 EXPORT_SYMBOL_GPL(mptcp_diag_fill_info); 906 907 static int mptcp_getsockopt_info(struct mptcp_sock *msk, char __user *optval, int __user *optlen) 908 { 909 struct mptcp_info m_info; 910 int len; 911 912 if (get_user(len, optlen)) 913 return -EFAULT; 914 915 len = min_t(unsigned int, len, sizeof(struct mptcp_info)); 916 917 mptcp_diag_fill_info(msk, &m_info); 918 919 if (put_user(len, optlen)) 920 return -EFAULT; 921 922 if (copy_to_user(optval, &m_info, len)) 923 return -EFAULT; 924 925 return 0; 926 } 927 928 static int mptcp_put_subflow_data(struct mptcp_subflow_data *sfd, 929 char __user *optval, 930 u32 copied, 931 int __user *optlen) 932 { 933 u32 copylen = min_t(u32, sfd->size_subflow_data, sizeof(*sfd)); 934 935 if (copied) 936 copied += sfd->size_subflow_data; 937 else 938 copied = copylen; 939 940 if (put_user(copied, optlen)) 941 return -EFAULT; 942 943 if (copy_to_user(optval, sfd, copylen)) 944 return -EFAULT; 945 946 return 0; 947 } 948 949 static int mptcp_get_subflow_data(struct mptcp_subflow_data *sfd, 950 char __user *optval, int __user *optlen) 951 { 952 int len, copylen; 953 954 if (get_user(len, optlen)) 955 return -EFAULT; 956 957 /* if mptcp_subflow_data size is changed, need to adjust 958 * this function to deal with programs using old version. 959 */ 960 BUILD_BUG_ON(sizeof(*sfd) != MIN_INFO_OPTLEN_SIZE); 961 962 if (len < MIN_INFO_OPTLEN_SIZE) 963 return -EINVAL; 964 965 memset(sfd, 0, sizeof(*sfd)); 966 967 copylen = min_t(unsigned int, len, sizeof(*sfd)); 968 if (copy_from_user(sfd, optval, copylen)) 969 return -EFAULT; 970 971 /* size_subflow_data is u32, but len is signed */ 972 if (sfd->size_subflow_data > INT_MAX || 973 sfd->size_user > INT_MAX) 974 return -EINVAL; 975 976 if (sfd->size_subflow_data < MIN_INFO_OPTLEN_SIZE || 977 sfd->size_subflow_data > len) 978 return -EINVAL; 979 980 if (sfd->num_subflows || sfd->size_kernel) 981 return -EINVAL; 982 983 return len - sfd->size_subflow_data; 984 } 985 986 static int mptcp_getsockopt_tcpinfo(struct mptcp_sock *msk, char __user *optval, 987 int __user *optlen) 988 { 989 struct mptcp_subflow_context *subflow; 990 struct sock *sk = (struct sock *)msk; 991 unsigned int sfcount = 0, copied = 0; 992 struct mptcp_subflow_data sfd; 993 char __user *infoptr; 994 int len; 995 996 len = mptcp_get_subflow_data(&sfd, optval, optlen); 997 if (len < 0) 998 return len; 999 1000 sfd.size_kernel = sizeof(struct tcp_info); 1001 sfd.size_user = min_t(unsigned int, sfd.size_user, 1002 sizeof(struct tcp_info)); 1003 1004 infoptr = optval + sfd.size_subflow_data; 1005 1006 lock_sock(sk); 1007 1008 mptcp_for_each_subflow(msk, subflow) { 1009 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 1010 1011 ++sfcount; 1012 1013 if (len && len >= sfd.size_user) { 1014 struct tcp_info info; 1015 1016 tcp_get_info(ssk, &info); 1017 1018 if (copy_to_user(infoptr, &info, sfd.size_user)) { 1019 release_sock(sk); 1020 return -EFAULT; 1021 } 1022 1023 infoptr += sfd.size_user; 1024 copied += sfd.size_user; 1025 len -= sfd.size_user; 1026 } 1027 } 1028 1029 release_sock(sk); 1030 1031 sfd.num_subflows = sfcount; 1032 1033 if (mptcp_put_subflow_data(&sfd, optval, copied, optlen)) 1034 return -EFAULT; 1035 1036 return 0; 1037 } 1038 1039 static void mptcp_get_sub_addrs(const struct sock *sk, struct mptcp_subflow_addrs *a) 1040 { 1041 struct inet_sock *inet = inet_sk(sk); 1042 1043 memset(a, 0, sizeof(*a)); 1044 1045 if (sk->sk_family == AF_INET) { 1046 a->sin_local.sin_family = AF_INET; 1047 a->sin_local.sin_port = inet->inet_sport; 1048 a->sin_local.sin_addr.s_addr = inet->inet_rcv_saddr; 1049 1050 if (!a->sin_local.sin_addr.s_addr) 1051 a->sin_local.sin_addr.s_addr = inet->inet_saddr; 1052 1053 a->sin_remote.sin_family = AF_INET; 1054 a->sin_remote.sin_port = inet->inet_dport; 1055 a->sin_remote.sin_addr.s_addr = inet->inet_daddr; 1056 #if IS_ENABLED(CONFIG_IPV6) 1057 } else if (sk->sk_family == AF_INET6) { 1058 const struct ipv6_pinfo *np = inet6_sk(sk); 1059 1060 if (WARN_ON_ONCE(!np)) 1061 return; 1062 1063 a->sin6_local.sin6_family = AF_INET6; 1064 a->sin6_local.sin6_port = inet->inet_sport; 1065 1066 if (ipv6_addr_any(&sk->sk_v6_rcv_saddr)) 1067 a->sin6_local.sin6_addr = np->saddr; 1068 else 1069 a->sin6_local.sin6_addr = sk->sk_v6_rcv_saddr; 1070 1071 a->sin6_remote.sin6_family = AF_INET6; 1072 a->sin6_remote.sin6_port = inet->inet_dport; 1073 a->sin6_remote.sin6_addr = sk->sk_v6_daddr; 1074 #endif 1075 } 1076 } 1077 1078 static int mptcp_getsockopt_subflow_addrs(struct mptcp_sock *msk, char __user *optval, 1079 int __user *optlen) 1080 { 1081 struct mptcp_subflow_context *subflow; 1082 struct sock *sk = (struct sock *)msk; 1083 unsigned int sfcount = 0, copied = 0; 1084 struct mptcp_subflow_data sfd; 1085 char __user *addrptr; 1086 int len; 1087 1088 len = mptcp_get_subflow_data(&sfd, optval, optlen); 1089 if (len < 0) 1090 return len; 1091 1092 sfd.size_kernel = sizeof(struct mptcp_subflow_addrs); 1093 sfd.size_user = min_t(unsigned int, sfd.size_user, 1094 sizeof(struct mptcp_subflow_addrs)); 1095 1096 addrptr = optval + sfd.size_subflow_data; 1097 1098 lock_sock(sk); 1099 1100 mptcp_for_each_subflow(msk, subflow) { 1101 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 1102 1103 ++sfcount; 1104 1105 if (len && len >= sfd.size_user) { 1106 struct mptcp_subflow_addrs a; 1107 1108 mptcp_get_sub_addrs(ssk, &a); 1109 1110 if (copy_to_user(addrptr, &a, sfd.size_user)) { 1111 release_sock(sk); 1112 return -EFAULT; 1113 } 1114 1115 addrptr += sfd.size_user; 1116 copied += sfd.size_user; 1117 len -= sfd.size_user; 1118 } 1119 } 1120 1121 release_sock(sk); 1122 1123 sfd.num_subflows = sfcount; 1124 1125 if (mptcp_put_subflow_data(&sfd, optval, copied, optlen)) 1126 return -EFAULT; 1127 1128 return 0; 1129 } 1130 1131 static int mptcp_put_int_option(struct mptcp_sock *msk, char __user *optval, 1132 int __user *optlen, int val) 1133 { 1134 int len; 1135 1136 if (get_user(len, optlen)) 1137 return -EFAULT; 1138 if (len < 0) 1139 return -EINVAL; 1140 1141 if (len < sizeof(int) && len > 0 && val >= 0 && val <= 255) { 1142 unsigned char ucval = (unsigned char)val; 1143 1144 len = 1; 1145 if (put_user(len, optlen)) 1146 return -EFAULT; 1147 if (copy_to_user(optval, &ucval, 1)) 1148 return -EFAULT; 1149 } else { 1150 len = min_t(unsigned int, len, sizeof(int)); 1151 if (put_user(len, optlen)) 1152 return -EFAULT; 1153 if (copy_to_user(optval, &val, len)) 1154 return -EFAULT; 1155 } 1156 1157 return 0; 1158 } 1159 1160 static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 1161 char __user *optval, int __user *optlen) 1162 { 1163 switch (optname) { 1164 case TCP_ULP: 1165 case TCP_CONGESTION: 1166 case TCP_INFO: 1167 case TCP_CC_INFO: 1168 case TCP_DEFER_ACCEPT: 1169 case TCP_FASTOPEN_CONNECT: 1170 case TCP_FASTOPEN_NO_COOKIE: 1171 return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname, 1172 optval, optlen); 1173 case TCP_INQ: 1174 return mptcp_put_int_option(msk, optval, optlen, msk->recvmsg_inq); 1175 case TCP_CORK: 1176 return mptcp_put_int_option(msk, optval, optlen, msk->cork); 1177 case TCP_NODELAY: 1178 return mptcp_put_int_option(msk, optval, optlen, msk->nodelay); 1179 } 1180 return -EOPNOTSUPP; 1181 } 1182 1183 static int mptcp_getsockopt_v4(struct mptcp_sock *msk, int optname, 1184 char __user *optval, int __user *optlen) 1185 { 1186 struct sock *sk = (void *)msk; 1187 1188 switch (optname) { 1189 case IP_TOS: 1190 return mptcp_put_int_option(msk, optval, optlen, inet_sk(sk)->tos); 1191 } 1192 1193 return -EOPNOTSUPP; 1194 } 1195 1196 static int mptcp_getsockopt_sol_mptcp(struct mptcp_sock *msk, int optname, 1197 char __user *optval, int __user *optlen) 1198 { 1199 switch (optname) { 1200 case MPTCP_INFO: 1201 return mptcp_getsockopt_info(msk, optval, optlen); 1202 case MPTCP_TCPINFO: 1203 return mptcp_getsockopt_tcpinfo(msk, optval, optlen); 1204 case MPTCP_SUBFLOW_ADDRS: 1205 return mptcp_getsockopt_subflow_addrs(msk, optval, optlen); 1206 } 1207 1208 return -EOPNOTSUPP; 1209 } 1210 1211 int mptcp_getsockopt(struct sock *sk, int level, int optname, 1212 char __user *optval, int __user *option) 1213 { 1214 struct mptcp_sock *msk = mptcp_sk(sk); 1215 struct sock *ssk; 1216 1217 pr_debug("msk=%p", msk); 1218 1219 /* @@ the meaning of setsockopt() when the socket is connected and 1220 * there are multiple subflows is not yet defined. It is up to the 1221 * MPTCP-level socket to configure the subflows until the subflow 1222 * is in TCP fallback, when socket options are passed through 1223 * to the one remaining subflow. 1224 */ 1225 lock_sock(sk); 1226 ssk = __mptcp_tcp_fallback(msk); 1227 release_sock(sk); 1228 if (ssk) 1229 return tcp_getsockopt(ssk, level, optname, optval, option); 1230 1231 if (level == SOL_IP) 1232 return mptcp_getsockopt_v4(msk, optname, optval, option); 1233 if (level == SOL_TCP) 1234 return mptcp_getsockopt_sol_tcp(msk, optname, optval, option); 1235 if (level == SOL_MPTCP) 1236 return mptcp_getsockopt_sol_mptcp(msk, optname, optval, option); 1237 return -EOPNOTSUPP; 1238 } 1239 1240 static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk) 1241 { 1242 static const unsigned int tx_rx_locks = SOCK_RCVBUF_LOCK | SOCK_SNDBUF_LOCK; 1243 struct sock *sk = (struct sock *)msk; 1244 1245 if (ssk->sk_prot->keepalive) { 1246 if (sock_flag(sk, SOCK_KEEPOPEN)) 1247 ssk->sk_prot->keepalive(ssk, 1); 1248 else 1249 ssk->sk_prot->keepalive(ssk, 0); 1250 } 1251 1252 ssk->sk_priority = sk->sk_priority; 1253 ssk->sk_bound_dev_if = sk->sk_bound_dev_if; 1254 ssk->sk_incoming_cpu = sk->sk_incoming_cpu; 1255 __ip_sock_set_tos(ssk, inet_sk(sk)->tos); 1256 1257 if (sk->sk_userlocks & tx_rx_locks) { 1258 ssk->sk_userlocks |= sk->sk_userlocks & tx_rx_locks; 1259 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) 1260 WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf); 1261 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) 1262 WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); 1263 } 1264 1265 if (sock_flag(sk, SOCK_LINGER)) { 1266 ssk->sk_lingertime = sk->sk_lingertime; 1267 sock_set_flag(ssk, SOCK_LINGER); 1268 } else { 1269 sock_reset_flag(ssk, SOCK_LINGER); 1270 } 1271 1272 if (sk->sk_mark != ssk->sk_mark) { 1273 ssk->sk_mark = sk->sk_mark; 1274 sk_dst_reset(ssk); 1275 } 1276 1277 sock_valbool_flag(ssk, SOCK_DBG, sock_flag(sk, SOCK_DBG)); 1278 1279 if (inet_csk(sk)->icsk_ca_ops != inet_csk(ssk)->icsk_ca_ops) 1280 tcp_set_congestion_control(ssk, msk->ca_name, false, true); 1281 __tcp_sock_set_cork(ssk, !!msk->cork); 1282 __tcp_sock_set_nodelay(ssk, !!msk->nodelay); 1283 1284 inet_sk(ssk)->transparent = inet_sk(sk)->transparent; 1285 inet_sk(ssk)->freebind = inet_sk(sk)->freebind; 1286 } 1287 1288 static void __mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) 1289 { 1290 bool slow = lock_sock_fast(ssk); 1291 1292 sync_socket_options(msk, ssk); 1293 1294 unlock_sock_fast(ssk, slow); 1295 } 1296 1297 void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) 1298 { 1299 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 1300 1301 msk_owned_by_me(msk); 1302 1303 if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) { 1304 __mptcp_sockopt_sync(msk, ssk); 1305 1306 subflow->setsockopt_seq = msk->setsockopt_seq; 1307 } 1308 } 1309 1310 void mptcp_sockopt_sync_locked(struct mptcp_sock *msk, struct sock *ssk) 1311 { 1312 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 1313 1314 msk_owned_by_me(msk); 1315 1316 if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) { 1317 sync_socket_options(msk, ssk); 1318 1319 subflow->setsockopt_seq = msk->setsockopt_seq; 1320 } 1321 } 1322