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 static struct sock *__mptcp_tcp_fallback(struct mptcp_sock *msk) 18 { 19 sock_owned_by_me((const struct sock *)msk); 20 21 if (likely(!__mptcp_check_fallback(msk))) 22 return NULL; 23 24 return msk->first; 25 } 26 27 static u32 sockopt_seq_reset(const struct sock *sk) 28 { 29 sock_owned_by_me(sk); 30 31 /* Highbits contain state. Allows to distinguish sockopt_seq 32 * of listener and established: 33 * s0 = new_listener() 34 * sockopt(s0) - seq is 1 35 * s1 = accept(s0) - s1 inherits seq 1 if listener sk (s0) 36 * sockopt(s0) - seq increments to 2 on s0 37 * sockopt(s1) // seq increments to 2 on s1 (different option) 38 * new ssk completes join, inherits options from s0 // seq 2 39 * Needs sync from mptcp join logic, but ssk->seq == msk->seq 40 * 41 * Set High order bits to sk_state so ssk->seq == msk->seq test 42 * will fail. 43 */ 44 45 return (u32)sk->sk_state << 24u; 46 } 47 48 static void sockopt_seq_inc(struct mptcp_sock *msk) 49 { 50 u32 seq = (msk->setsockopt_seq + 1) & 0x00ffffff; 51 52 msk->setsockopt_seq = sockopt_seq_reset((struct sock *)msk) + seq; 53 } 54 55 static int mptcp_get_int_option(struct mptcp_sock *msk, sockptr_t optval, 56 unsigned int optlen, int *val) 57 { 58 if (optlen < sizeof(int)) 59 return -EINVAL; 60 61 if (copy_from_sockptr(val, optval, sizeof(*val))) 62 return -EFAULT; 63 64 return 0; 65 } 66 67 static void mptcp_sol_socket_sync_intval(struct mptcp_sock *msk, int optname, int val) 68 { 69 struct mptcp_subflow_context *subflow; 70 struct sock *sk = (struct sock *)msk; 71 72 lock_sock(sk); 73 sockopt_seq_inc(msk); 74 75 mptcp_for_each_subflow(msk, subflow) { 76 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 77 bool slow = lock_sock_fast(ssk); 78 79 switch (optname) { 80 case SO_DEBUG: 81 sock_valbool_flag(ssk, SOCK_DBG, !!val); 82 break; 83 case SO_KEEPALIVE: 84 if (ssk->sk_prot->keepalive) 85 ssk->sk_prot->keepalive(ssk, !!val); 86 sock_valbool_flag(ssk, SOCK_KEEPOPEN, !!val); 87 break; 88 case SO_PRIORITY: 89 ssk->sk_priority = val; 90 break; 91 case SO_SNDBUF: 92 case SO_SNDBUFFORCE: 93 ssk->sk_userlocks |= SOCK_SNDBUF_LOCK; 94 WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf); 95 break; 96 case SO_RCVBUF: 97 case SO_RCVBUFFORCE: 98 ssk->sk_userlocks |= SOCK_RCVBUF_LOCK; 99 WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); 100 break; 101 case SO_MARK: 102 if (READ_ONCE(ssk->sk_mark) != sk->sk_mark) { 103 ssk->sk_mark = sk->sk_mark; 104 sk_dst_reset(ssk); 105 } 106 break; 107 case SO_INCOMING_CPU: 108 WRITE_ONCE(ssk->sk_incoming_cpu, val); 109 break; 110 } 111 112 subflow->setsockopt_seq = msk->setsockopt_seq; 113 unlock_sock_fast(ssk, slow); 114 } 115 116 release_sock(sk); 117 } 118 119 static int mptcp_sol_socket_intval(struct mptcp_sock *msk, int optname, int val) 120 { 121 sockptr_t optval = KERNEL_SOCKPTR(&val); 122 struct sock *sk = (struct sock *)msk; 123 int ret; 124 125 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, 126 optval, sizeof(val)); 127 if (ret) 128 return ret; 129 130 mptcp_sol_socket_sync_intval(msk, optname, val); 131 return 0; 132 } 133 134 static void mptcp_so_incoming_cpu(struct mptcp_sock *msk, int val) 135 { 136 struct sock *sk = (struct sock *)msk; 137 138 WRITE_ONCE(sk->sk_incoming_cpu, val); 139 140 mptcp_sol_socket_sync_intval(msk, SO_INCOMING_CPU, val); 141 } 142 143 static int mptcp_setsockopt_sol_socket_int(struct mptcp_sock *msk, int optname, 144 sockptr_t optval, unsigned int optlen) 145 { 146 int val, ret; 147 148 ret = mptcp_get_int_option(msk, optval, optlen, &val); 149 if (ret) 150 return ret; 151 152 switch (optname) { 153 case SO_KEEPALIVE: 154 mptcp_sol_socket_sync_intval(msk, optname, val); 155 return 0; 156 case SO_DEBUG: 157 case SO_MARK: 158 case SO_PRIORITY: 159 case SO_SNDBUF: 160 case SO_SNDBUFFORCE: 161 case SO_RCVBUF: 162 case SO_RCVBUFFORCE: 163 return mptcp_sol_socket_intval(msk, optname, val); 164 case SO_INCOMING_CPU: 165 mptcp_so_incoming_cpu(msk, val); 166 return 0; 167 } 168 169 return -ENOPROTOOPT; 170 } 171 172 static int mptcp_setsockopt_sol_socket_linger(struct mptcp_sock *msk, sockptr_t optval, 173 unsigned int optlen) 174 { 175 struct mptcp_subflow_context *subflow; 176 struct sock *sk = (struct sock *)msk; 177 struct linger ling; 178 sockptr_t kopt; 179 int ret; 180 181 if (optlen < sizeof(ling)) 182 return -EINVAL; 183 184 if (copy_from_sockptr(&ling, optval, sizeof(ling))) 185 return -EFAULT; 186 187 kopt = KERNEL_SOCKPTR(&ling); 188 ret = sock_setsockopt(sk->sk_socket, SOL_SOCKET, SO_LINGER, kopt, sizeof(ling)); 189 if (ret) 190 return ret; 191 192 lock_sock(sk); 193 sockopt_seq_inc(msk); 194 mptcp_for_each_subflow(msk, subflow) { 195 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 196 bool slow = lock_sock_fast(ssk); 197 198 if (!ling.l_onoff) { 199 sock_reset_flag(ssk, SOCK_LINGER); 200 } else { 201 ssk->sk_lingertime = sk->sk_lingertime; 202 sock_set_flag(ssk, SOCK_LINGER); 203 } 204 205 subflow->setsockopt_seq = msk->setsockopt_seq; 206 unlock_sock_fast(ssk, slow); 207 } 208 209 release_sock(sk); 210 return 0; 211 } 212 213 static int mptcp_setsockopt_sol_socket(struct mptcp_sock *msk, int optname, 214 sockptr_t optval, unsigned int optlen) 215 { 216 struct sock *sk = (struct sock *)msk; 217 struct socket *ssock; 218 int ret; 219 220 switch (optname) { 221 case SO_REUSEPORT: 222 case SO_REUSEADDR: 223 case SO_BINDTODEVICE: 224 case SO_BINDTOIFINDEX: 225 lock_sock(sk); 226 ssock = __mptcp_nmpc_socket(msk); 227 if (!ssock) { 228 release_sock(sk); 229 return -EINVAL; 230 } 231 232 ret = sock_setsockopt(ssock, SOL_SOCKET, optname, optval, optlen); 233 if (ret == 0) { 234 if (optname == SO_REUSEPORT) 235 sk->sk_reuseport = ssock->sk->sk_reuseport; 236 else if (optname == SO_REUSEADDR) 237 sk->sk_reuse = ssock->sk->sk_reuse; 238 else if (optname == SO_BINDTODEVICE) 239 sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if; 240 else if (optname == SO_BINDTOIFINDEX) 241 sk->sk_bound_dev_if = ssock->sk->sk_bound_dev_if; 242 } 243 release_sock(sk); 244 return ret; 245 case SO_KEEPALIVE: 246 case SO_PRIORITY: 247 case SO_SNDBUF: 248 case SO_SNDBUFFORCE: 249 case SO_RCVBUF: 250 case SO_RCVBUFFORCE: 251 case SO_MARK: 252 case SO_INCOMING_CPU: 253 case SO_DEBUG: 254 return mptcp_setsockopt_sol_socket_int(msk, optname, optval, optlen); 255 case SO_LINGER: 256 return mptcp_setsockopt_sol_socket_linger(msk, optval, optlen); 257 case SO_NO_CHECK: 258 case SO_DONTROUTE: 259 case SO_BROADCAST: 260 case SO_BSDCOMPAT: 261 case SO_PASSCRED: 262 case SO_PASSSEC: 263 case SO_RXQ_OVFL: 264 case SO_WIFI_STATUS: 265 case SO_NOFCS: 266 case SO_SELECT_ERR_QUEUE: 267 return 0; 268 } 269 270 return sock_setsockopt(sk->sk_socket, SOL_SOCKET, optname, optval, optlen); 271 } 272 273 static int mptcp_setsockopt_v6(struct mptcp_sock *msk, int optname, 274 sockptr_t optval, unsigned int optlen) 275 { 276 struct sock *sk = (struct sock *)msk; 277 int ret = -EOPNOTSUPP; 278 struct socket *ssock; 279 280 switch (optname) { 281 case IPV6_V6ONLY: 282 lock_sock(sk); 283 ssock = __mptcp_nmpc_socket(msk); 284 if (!ssock) { 285 release_sock(sk); 286 return -EINVAL; 287 } 288 289 ret = tcp_setsockopt(ssock->sk, SOL_IPV6, optname, optval, optlen); 290 if (ret == 0) 291 sk->sk_ipv6only = ssock->sk->sk_ipv6only; 292 293 release_sock(sk); 294 break; 295 } 296 297 return ret; 298 } 299 300 static bool mptcp_supported_sockopt(int level, int optname) 301 { 302 if (level == SOL_SOCKET) { 303 switch (optname) { 304 case SO_DEBUG: 305 case SO_REUSEPORT: 306 case SO_REUSEADDR: 307 308 /* the following ones need a better implementation, 309 * but are quite common we want to preserve them 310 */ 311 case SO_BINDTODEVICE: 312 case SO_SNDBUF: 313 case SO_SNDBUFFORCE: 314 case SO_RCVBUF: 315 case SO_RCVBUFFORCE: 316 case SO_KEEPALIVE: 317 case SO_PRIORITY: 318 case SO_LINGER: 319 case SO_TIMESTAMP_OLD: 320 case SO_TIMESTAMP_NEW: 321 case SO_TIMESTAMPNS_OLD: 322 case SO_TIMESTAMPNS_NEW: 323 case SO_TIMESTAMPING_OLD: 324 case SO_TIMESTAMPING_NEW: 325 case SO_RCVLOWAT: 326 case SO_RCVTIMEO_OLD: 327 case SO_RCVTIMEO_NEW: 328 case SO_SNDTIMEO_OLD: 329 case SO_SNDTIMEO_NEW: 330 case SO_MARK: 331 case SO_INCOMING_CPU: 332 case SO_BINDTOIFINDEX: 333 case SO_BUSY_POLL: 334 case SO_PREFER_BUSY_POLL: 335 case SO_BUSY_POLL_BUDGET: 336 337 /* next ones are no-op for plain TCP */ 338 case SO_NO_CHECK: 339 case SO_DONTROUTE: 340 case SO_BROADCAST: 341 case SO_BSDCOMPAT: 342 case SO_PASSCRED: 343 case SO_PASSSEC: 344 case SO_RXQ_OVFL: 345 case SO_WIFI_STATUS: 346 case SO_NOFCS: 347 case SO_SELECT_ERR_QUEUE: 348 return true; 349 } 350 351 /* SO_OOBINLINE is not supported, let's avoid the related mess */ 352 /* SO_ATTACH_FILTER, SO_ATTACH_BPF, SO_ATTACH_REUSEPORT_CBPF, 353 * SO_DETACH_REUSEPORT_BPF, SO_DETACH_FILTER, SO_LOCK_FILTER, 354 * we must be careful with subflows 355 */ 356 /* SO_ATTACH_REUSEPORT_EBPF is not supported, at it checks 357 * explicitly the sk_protocol field 358 */ 359 /* SO_PEEK_OFF is unsupported, as it is for plain TCP */ 360 /* SO_MAX_PACING_RATE is unsupported, we must be careful with subflows */ 361 /* SO_CNX_ADVICE is currently unsupported, could possibly be relevant, 362 * but likely needs careful design 363 */ 364 /* SO_ZEROCOPY is currently unsupported, TODO in sndmsg */ 365 /* SO_TXTIME is currently unsupported */ 366 return false; 367 } 368 if (level == SOL_IP) { 369 switch (optname) { 370 /* should work fine */ 371 case IP_FREEBIND: 372 case IP_TRANSPARENT: 373 374 /* the following are control cmsg related */ 375 case IP_PKTINFO: 376 case IP_RECVTTL: 377 case IP_RECVTOS: 378 case IP_RECVOPTS: 379 case IP_RETOPTS: 380 case IP_PASSSEC: 381 case IP_RECVORIGDSTADDR: 382 case IP_CHECKSUM: 383 case IP_RECVFRAGSIZE: 384 385 /* common stuff that need some love */ 386 case IP_TOS: 387 case IP_TTL: 388 case IP_BIND_ADDRESS_NO_PORT: 389 case IP_MTU_DISCOVER: 390 case IP_RECVERR: 391 392 /* possibly less common may deserve some love */ 393 case IP_MINTTL: 394 395 /* the following is apparently a no-op for plain TCP */ 396 case IP_RECVERR_RFC4884: 397 return true; 398 } 399 400 /* IP_OPTIONS is not supported, needs subflow care */ 401 /* IP_HDRINCL, IP_NODEFRAG are not supported, RAW specific */ 402 /* IP_MULTICAST_TTL, IP_MULTICAST_LOOP, IP_UNICAST_IF, 403 * IP_ADD_MEMBERSHIP, IP_ADD_SOURCE_MEMBERSHIP, IP_DROP_MEMBERSHIP, 404 * IP_DROP_SOURCE_MEMBERSHIP, IP_BLOCK_SOURCE, IP_UNBLOCK_SOURCE, 405 * MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP MCAST_JOIN_SOURCE_GROUP, 406 * MCAST_LEAVE_SOURCE_GROUP, MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, 407 * MCAST_MSFILTER, IP_MULTICAST_ALL are not supported, better not deal 408 * with mcast stuff 409 */ 410 /* IP_IPSEC_POLICY, IP_XFRM_POLICY are nut supported, unrelated here */ 411 return false; 412 } 413 if (level == SOL_IPV6) { 414 switch (optname) { 415 case IPV6_V6ONLY: 416 417 /* the following are control cmsg related */ 418 case IPV6_RECVPKTINFO: 419 case IPV6_2292PKTINFO: 420 case IPV6_RECVHOPLIMIT: 421 case IPV6_2292HOPLIMIT: 422 case IPV6_RECVRTHDR: 423 case IPV6_2292RTHDR: 424 case IPV6_RECVHOPOPTS: 425 case IPV6_2292HOPOPTS: 426 case IPV6_RECVDSTOPTS: 427 case IPV6_2292DSTOPTS: 428 case IPV6_RECVTCLASS: 429 case IPV6_FLOWINFO: 430 case IPV6_RECVPATHMTU: 431 case IPV6_RECVORIGDSTADDR: 432 case IPV6_RECVFRAGSIZE: 433 434 /* the following ones need some love but are quite common */ 435 case IPV6_TCLASS: 436 case IPV6_TRANSPARENT: 437 case IPV6_FREEBIND: 438 case IPV6_PKTINFO: 439 case IPV6_2292PKTOPTIONS: 440 case IPV6_UNICAST_HOPS: 441 case IPV6_MTU_DISCOVER: 442 case IPV6_MTU: 443 case IPV6_RECVERR: 444 case IPV6_FLOWINFO_SEND: 445 case IPV6_FLOWLABEL_MGR: 446 case IPV6_MINHOPCOUNT: 447 case IPV6_DONTFRAG: 448 case IPV6_AUTOFLOWLABEL: 449 450 /* the following one is a no-op for plain TCP */ 451 case IPV6_RECVERR_RFC4884: 452 return true; 453 } 454 455 /* IPV6_HOPOPTS, IPV6_RTHDRDSTOPTS, IPV6_RTHDR, IPV6_DSTOPTS are 456 * not supported 457 */ 458 /* IPV6_MULTICAST_HOPS, IPV6_MULTICAST_LOOP, IPV6_UNICAST_IF, 459 * IPV6_MULTICAST_IF, IPV6_ADDRFORM, 460 * IPV6_ADD_MEMBERSHIP, IPV6_DROP_MEMBERSHIP, IPV6_JOIN_ANYCAST, 461 * IPV6_LEAVE_ANYCAST, IPV6_MULTICAST_ALL, MCAST_JOIN_GROUP, MCAST_LEAVE_GROUP, 462 * MCAST_JOIN_SOURCE_GROUP, MCAST_LEAVE_SOURCE_GROUP, 463 * MCAST_BLOCK_SOURCE, MCAST_UNBLOCK_SOURCE, MCAST_MSFILTER 464 * are not supported better not deal with mcast 465 */ 466 /* IPV6_ROUTER_ALERT, IPV6_ROUTER_ALERT_ISOLATE are not supported, since are evil */ 467 468 /* IPV6_IPSEC_POLICY, IPV6_XFRM_POLICY are not supported */ 469 /* IPV6_ADDR_PREFERENCES is not supported, we must be careful with subflows */ 470 return false; 471 } 472 if (level == SOL_TCP) { 473 switch (optname) { 474 /* the following are no-op or should work just fine */ 475 case TCP_THIN_DUPACK: 476 case TCP_DEFER_ACCEPT: 477 478 /* the following need some love */ 479 case TCP_MAXSEG: 480 case TCP_NODELAY: 481 case TCP_THIN_LINEAR_TIMEOUTS: 482 case TCP_CONGESTION: 483 case TCP_ULP: 484 case TCP_CORK: 485 case TCP_KEEPIDLE: 486 case TCP_KEEPINTVL: 487 case TCP_KEEPCNT: 488 case TCP_SYNCNT: 489 case TCP_SAVE_SYN: 490 case TCP_LINGER2: 491 case TCP_WINDOW_CLAMP: 492 case TCP_QUICKACK: 493 case TCP_USER_TIMEOUT: 494 case TCP_TIMESTAMP: 495 case TCP_NOTSENT_LOWAT: 496 case TCP_TX_DELAY: 497 return true; 498 } 499 500 /* TCP_MD5SIG, TCP_MD5SIG_EXT are not supported, MD5 is not compatible with MPTCP */ 501 502 /* TCP_REPAIR, TCP_REPAIR_QUEUE, TCP_QUEUE_SEQ, TCP_REPAIR_OPTIONS, 503 * TCP_REPAIR_WINDOW are not supported, better avoid this mess 504 */ 505 /* TCP_FASTOPEN_KEY, TCP_FASTOPEN TCP_FASTOPEN_CONNECT, TCP_FASTOPEN_NO_COOKIE, 506 * are not supported fastopen is currently unsupported 507 */ 508 /* TCP_INQ is currently unsupported, needs some recvmsg work */ 509 } 510 return false; 511 } 512 513 static int mptcp_setsockopt_sol_tcp_congestion(struct mptcp_sock *msk, sockptr_t optval, 514 unsigned int optlen) 515 { 516 struct mptcp_subflow_context *subflow; 517 struct sock *sk = (struct sock *)msk; 518 char name[TCP_CA_NAME_MAX]; 519 bool cap_net_admin; 520 int ret; 521 522 if (optlen < 1) 523 return -EINVAL; 524 525 ret = strncpy_from_sockptr(name, optval, 526 min_t(long, TCP_CA_NAME_MAX - 1, optlen)); 527 if (ret < 0) 528 return -EFAULT; 529 530 name[ret] = 0; 531 532 cap_net_admin = ns_capable(sock_net(sk)->user_ns, CAP_NET_ADMIN); 533 534 ret = 0; 535 lock_sock(sk); 536 sockopt_seq_inc(msk); 537 mptcp_for_each_subflow(msk, subflow) { 538 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 539 int err; 540 541 lock_sock(ssk); 542 err = tcp_set_congestion_control(ssk, name, true, cap_net_admin); 543 if (err < 0 && ret == 0) 544 ret = err; 545 subflow->setsockopt_seq = msk->setsockopt_seq; 546 release_sock(ssk); 547 } 548 549 if (ret == 0) 550 tcp_set_congestion_control(sk, name, false, cap_net_admin); 551 552 release_sock(sk); 553 return ret; 554 } 555 556 static int mptcp_setsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 557 sockptr_t optval, unsigned int optlen) 558 { 559 switch (optname) { 560 case TCP_ULP: 561 return -EOPNOTSUPP; 562 case TCP_CONGESTION: 563 return mptcp_setsockopt_sol_tcp_congestion(msk, optval, optlen); 564 } 565 566 return -EOPNOTSUPP; 567 } 568 569 int mptcp_setsockopt(struct sock *sk, int level, int optname, 570 sockptr_t optval, unsigned int optlen) 571 { 572 struct mptcp_sock *msk = mptcp_sk(sk); 573 struct sock *ssk; 574 575 pr_debug("msk=%p", msk); 576 577 if (!mptcp_supported_sockopt(level, optname)) 578 return -ENOPROTOOPT; 579 580 if (level == SOL_SOCKET) 581 return mptcp_setsockopt_sol_socket(msk, optname, optval, optlen); 582 583 /* @@ the meaning of setsockopt() when the socket is connected and 584 * there are multiple subflows is not yet defined. It is up to the 585 * MPTCP-level socket to configure the subflows until the subflow 586 * is in TCP fallback, when TCP socket options are passed through 587 * to the one remaining subflow. 588 */ 589 lock_sock(sk); 590 ssk = __mptcp_tcp_fallback(msk); 591 release_sock(sk); 592 if (ssk) 593 return tcp_setsockopt(ssk, level, optname, optval, optlen); 594 595 if (level == SOL_IPV6) 596 return mptcp_setsockopt_v6(msk, optname, optval, optlen); 597 598 if (level == SOL_TCP) 599 return mptcp_setsockopt_sol_tcp(msk, optname, optval, optlen); 600 601 return -EOPNOTSUPP; 602 } 603 604 static int mptcp_getsockopt_first_sf_only(struct mptcp_sock *msk, int level, int optname, 605 char __user *optval, int __user *optlen) 606 { 607 struct sock *sk = (struct sock *)msk; 608 struct socket *ssock; 609 int ret = -EINVAL; 610 struct sock *ssk; 611 612 lock_sock(sk); 613 ssk = msk->first; 614 if (ssk) { 615 ret = tcp_getsockopt(ssk, level, optname, optval, optlen); 616 goto out; 617 } 618 619 ssock = __mptcp_nmpc_socket(msk); 620 if (!ssock) 621 goto out; 622 623 ret = tcp_getsockopt(ssock->sk, level, optname, optval, optlen); 624 625 out: 626 release_sock(sk); 627 return ret; 628 } 629 630 static int mptcp_getsockopt_sol_tcp(struct mptcp_sock *msk, int optname, 631 char __user *optval, int __user *optlen) 632 { 633 switch (optname) { 634 case TCP_ULP: 635 case TCP_CONGESTION: 636 case TCP_INFO: 637 case TCP_CC_INFO: 638 return mptcp_getsockopt_first_sf_only(msk, SOL_TCP, optname, 639 optval, optlen); 640 } 641 return -EOPNOTSUPP; 642 } 643 644 int mptcp_getsockopt(struct sock *sk, int level, int optname, 645 char __user *optval, int __user *option) 646 { 647 struct mptcp_sock *msk = mptcp_sk(sk); 648 struct sock *ssk; 649 650 pr_debug("msk=%p", msk); 651 652 /* @@ the meaning of setsockopt() when the socket is connected and 653 * there are multiple subflows is not yet defined. It is up to the 654 * MPTCP-level socket to configure the subflows until the subflow 655 * is in TCP fallback, when socket options are passed through 656 * to the one remaining subflow. 657 */ 658 lock_sock(sk); 659 ssk = __mptcp_tcp_fallback(msk); 660 release_sock(sk); 661 if (ssk) 662 return tcp_getsockopt(ssk, level, optname, optval, option); 663 664 if (level == SOL_TCP) 665 return mptcp_getsockopt_sol_tcp(msk, optname, optval, option); 666 return -EOPNOTSUPP; 667 } 668 669 static void sync_socket_options(struct mptcp_sock *msk, struct sock *ssk) 670 { 671 static const unsigned int tx_rx_locks = SOCK_RCVBUF_LOCK | SOCK_SNDBUF_LOCK; 672 struct sock *sk = (struct sock *)msk; 673 674 if (ssk->sk_prot->keepalive) { 675 if (sock_flag(sk, SOCK_KEEPOPEN)) 676 ssk->sk_prot->keepalive(ssk, 1); 677 else 678 ssk->sk_prot->keepalive(ssk, 0); 679 } 680 681 ssk->sk_priority = sk->sk_priority; 682 ssk->sk_bound_dev_if = sk->sk_bound_dev_if; 683 ssk->sk_incoming_cpu = sk->sk_incoming_cpu; 684 685 if (sk->sk_userlocks & tx_rx_locks) { 686 ssk->sk_userlocks |= sk->sk_userlocks & tx_rx_locks; 687 if (sk->sk_userlocks & SOCK_SNDBUF_LOCK) 688 WRITE_ONCE(ssk->sk_sndbuf, sk->sk_sndbuf); 689 if (sk->sk_userlocks & SOCK_RCVBUF_LOCK) 690 WRITE_ONCE(ssk->sk_rcvbuf, sk->sk_rcvbuf); 691 } 692 693 if (sock_flag(sk, SOCK_LINGER)) { 694 ssk->sk_lingertime = sk->sk_lingertime; 695 sock_set_flag(ssk, SOCK_LINGER); 696 } else { 697 sock_reset_flag(ssk, SOCK_LINGER); 698 } 699 700 if (sk->sk_mark != ssk->sk_mark) { 701 ssk->sk_mark = sk->sk_mark; 702 sk_dst_reset(ssk); 703 } 704 705 sock_valbool_flag(ssk, SOCK_DBG, sock_flag(sk, SOCK_DBG)); 706 707 if (inet_csk(sk)->icsk_ca_ops != inet_csk(ssk)->icsk_ca_ops) 708 tcp_set_congestion_control(ssk, inet_csk(sk)->icsk_ca_ops->name, false, true); 709 } 710 711 static void __mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) 712 { 713 bool slow = lock_sock_fast(ssk); 714 715 sync_socket_options(msk, ssk); 716 717 unlock_sock_fast(ssk, slow); 718 } 719 720 void mptcp_sockopt_sync(struct mptcp_sock *msk, struct sock *ssk) 721 { 722 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 723 724 msk_owned_by_me(msk); 725 726 if (READ_ONCE(subflow->setsockopt_seq) != msk->setsockopt_seq) { 727 __mptcp_sockopt_sync(msk, ssk); 728 729 subflow->setsockopt_seq = msk->setsockopt_seq; 730 } 731 } 732 733 void mptcp_sockopt_sync_all(struct mptcp_sock *msk) 734 { 735 struct mptcp_subflow_context *subflow; 736 struct sock *sk = (struct sock *)msk; 737 u32 seq; 738 739 seq = sockopt_seq_reset(sk); 740 741 mptcp_for_each_subflow(msk, subflow) { 742 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 743 u32 sseq = READ_ONCE(subflow->setsockopt_seq); 744 745 if (sseq != msk->setsockopt_seq) { 746 __mptcp_sockopt_sync(msk, ssk); 747 WRITE_ONCE(subflow->setsockopt_seq, seq); 748 } else if (sseq != seq) { 749 WRITE_ONCE(subflow->setsockopt_seq, seq); 750 } 751 752 cond_resched(); 753 } 754 755 msk->setsockopt_seq = seq; 756 } 757