1 // SPDX-License-Identifier: GPL-2.0 2 /* Multipath TCP 3 * 4 * Copyright (c) 2017 - 2019, Intel Corporation. 5 */ 6 7 #define pr_fmt(fmt) "MPTCP: " fmt 8 9 #include <linux/kernel.h> 10 #include <linux/module.h> 11 #include <linux/netdevice.h> 12 #include <linux/sched/signal.h> 13 #include <linux/atomic.h> 14 #include <net/sock.h> 15 #include <net/inet_common.h> 16 #include <net/inet_hashtables.h> 17 #include <net/protocol.h> 18 #include <net/tcp.h> 19 #include <net/tcp_states.h> 20 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 21 #include <net/transp_v6.h> 22 #endif 23 #include <net/mptcp.h> 24 #include <net/xfrm.h> 25 #include <asm/ioctls.h> 26 #include "protocol.h" 27 #include "mib.h" 28 29 #define CREATE_TRACE_POINTS 30 #include <trace/events/mptcp.h> 31 32 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 33 struct mptcp6_sock { 34 struct mptcp_sock msk; 35 struct ipv6_pinfo np; 36 }; 37 #endif 38 39 struct mptcp_skb_cb { 40 u64 map_seq; 41 u64 end_seq; 42 u32 offset; 43 u8 has_rxtstamp:1; 44 }; 45 46 #define MPTCP_SKB_CB(__skb) ((struct mptcp_skb_cb *)&((__skb)->cb[0])) 47 48 enum { 49 MPTCP_CMSG_TS = BIT(0), 50 MPTCP_CMSG_INQ = BIT(1), 51 }; 52 53 static struct percpu_counter mptcp_sockets_allocated ____cacheline_aligned_in_smp; 54 55 static void __mptcp_destroy_sock(struct sock *sk); 56 static void __mptcp_check_send_data_fin(struct sock *sk); 57 58 DEFINE_PER_CPU(struct mptcp_delegated_action, mptcp_delegated_actions); 59 static struct net_device mptcp_napi_dev; 60 61 /* If msk has an initial subflow socket, and the MP_CAPABLE handshake has not 62 * completed yet or has failed, return the subflow socket. 63 * Otherwise return NULL. 64 */ 65 struct socket *__mptcp_nmpc_socket(const struct mptcp_sock *msk) 66 { 67 if (!msk->subflow || READ_ONCE(msk->can_ack)) 68 return NULL; 69 70 return msk->subflow; 71 } 72 73 /* Returns end sequence number of the receiver's advertised window */ 74 static u64 mptcp_wnd_end(const struct mptcp_sock *msk) 75 { 76 return READ_ONCE(msk->wnd_end); 77 } 78 79 static bool mptcp_is_tcpsk(struct sock *sk) 80 { 81 struct socket *sock = sk->sk_socket; 82 83 if (unlikely(sk->sk_prot == &tcp_prot)) { 84 /* we are being invoked after mptcp_accept() has 85 * accepted a non-mp-capable flow: sk is a tcp_sk, 86 * not an mptcp one. 87 * 88 * Hand the socket over to tcp so all further socket ops 89 * bypass mptcp. 90 */ 91 sock->ops = &inet_stream_ops; 92 return true; 93 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 94 } else if (unlikely(sk->sk_prot == &tcpv6_prot)) { 95 sock->ops = &inet6_stream_ops; 96 return true; 97 #endif 98 } 99 100 return false; 101 } 102 103 static int __mptcp_socket_create(struct mptcp_sock *msk) 104 { 105 struct mptcp_subflow_context *subflow; 106 struct sock *sk = (struct sock *)msk; 107 struct socket *ssock; 108 int err; 109 110 err = mptcp_subflow_create_socket(sk, &ssock); 111 if (err) 112 return err; 113 114 msk->first = ssock->sk; 115 msk->subflow = ssock; 116 subflow = mptcp_subflow_ctx(ssock->sk); 117 list_add(&subflow->node, &msk->conn_list); 118 sock_hold(ssock->sk); 119 subflow->request_mptcp = 1; 120 121 /* This is the first subflow, always with id 0 */ 122 subflow->local_id_valid = 1; 123 mptcp_sock_graft(msk->first, sk->sk_socket); 124 125 return 0; 126 } 127 128 static void mptcp_drop(struct sock *sk, struct sk_buff *skb) 129 { 130 sk_drops_add(sk, skb); 131 __kfree_skb(skb); 132 } 133 134 static void mptcp_rmem_charge(struct sock *sk, int size) 135 { 136 mptcp_sk(sk)->rmem_fwd_alloc -= size; 137 } 138 139 static bool mptcp_try_coalesce(struct sock *sk, struct sk_buff *to, 140 struct sk_buff *from) 141 { 142 bool fragstolen; 143 int delta; 144 145 if (MPTCP_SKB_CB(from)->offset || 146 !skb_try_coalesce(to, from, &fragstolen, &delta)) 147 return false; 148 149 pr_debug("colesced seq %llx into %llx new len %d new end seq %llx", 150 MPTCP_SKB_CB(from)->map_seq, MPTCP_SKB_CB(to)->map_seq, 151 to->len, MPTCP_SKB_CB(from)->end_seq); 152 MPTCP_SKB_CB(to)->end_seq = MPTCP_SKB_CB(from)->end_seq; 153 kfree_skb_partial(from, fragstolen); 154 atomic_add(delta, &sk->sk_rmem_alloc); 155 mptcp_rmem_charge(sk, delta); 156 return true; 157 } 158 159 static bool mptcp_ooo_try_coalesce(struct mptcp_sock *msk, struct sk_buff *to, 160 struct sk_buff *from) 161 { 162 if (MPTCP_SKB_CB(from)->map_seq != MPTCP_SKB_CB(to)->end_seq) 163 return false; 164 165 return mptcp_try_coalesce((struct sock *)msk, to, from); 166 } 167 168 static void __mptcp_rmem_reclaim(struct sock *sk, int amount) 169 { 170 amount >>= SK_MEM_QUANTUM_SHIFT; 171 mptcp_sk(sk)->rmem_fwd_alloc -= amount << SK_MEM_QUANTUM_SHIFT; 172 __sk_mem_reduce_allocated(sk, amount); 173 } 174 175 static void mptcp_rmem_uncharge(struct sock *sk, int size) 176 { 177 struct mptcp_sock *msk = mptcp_sk(sk); 178 int reclaimable; 179 180 msk->rmem_fwd_alloc += size; 181 reclaimable = msk->rmem_fwd_alloc - sk_unused_reserved_mem(sk); 182 183 /* see sk_mem_uncharge() for the rationale behind the following schema */ 184 if (unlikely(reclaimable >= SK_RECLAIM_THRESHOLD)) 185 __mptcp_rmem_reclaim(sk, SK_RECLAIM_CHUNK); 186 } 187 188 static void mptcp_rfree(struct sk_buff *skb) 189 { 190 unsigned int len = skb->truesize; 191 struct sock *sk = skb->sk; 192 193 atomic_sub(len, &sk->sk_rmem_alloc); 194 mptcp_rmem_uncharge(sk, len); 195 } 196 197 static void mptcp_set_owner_r(struct sk_buff *skb, struct sock *sk) 198 { 199 skb_orphan(skb); 200 skb->sk = sk; 201 skb->destructor = mptcp_rfree; 202 atomic_add(skb->truesize, &sk->sk_rmem_alloc); 203 mptcp_rmem_charge(sk, skb->truesize); 204 } 205 206 /* "inspired" by tcp_data_queue_ofo(), main differences: 207 * - use mptcp seqs 208 * - don't cope with sacks 209 */ 210 static void mptcp_data_queue_ofo(struct mptcp_sock *msk, struct sk_buff *skb) 211 { 212 struct sock *sk = (struct sock *)msk; 213 struct rb_node **p, *parent; 214 u64 seq, end_seq, max_seq; 215 struct sk_buff *skb1; 216 217 seq = MPTCP_SKB_CB(skb)->map_seq; 218 end_seq = MPTCP_SKB_CB(skb)->end_seq; 219 max_seq = atomic64_read(&msk->rcv_wnd_sent); 220 221 pr_debug("msk=%p seq=%llx limit=%llx empty=%d", msk, seq, max_seq, 222 RB_EMPTY_ROOT(&msk->out_of_order_queue)); 223 if (after64(end_seq, max_seq)) { 224 /* out of window */ 225 mptcp_drop(sk, skb); 226 pr_debug("oow by %lld, rcv_wnd_sent %llu\n", 227 (unsigned long long)end_seq - (unsigned long)max_seq, 228 (unsigned long long)atomic64_read(&msk->rcv_wnd_sent)); 229 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_NODSSWINDOW); 230 return; 231 } 232 233 p = &msk->out_of_order_queue.rb_node; 234 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUE); 235 if (RB_EMPTY_ROOT(&msk->out_of_order_queue)) { 236 rb_link_node(&skb->rbnode, NULL, p); 237 rb_insert_color(&skb->rbnode, &msk->out_of_order_queue); 238 msk->ooo_last_skb = skb; 239 goto end; 240 } 241 242 /* with 2 subflows, adding at end of ooo queue is quite likely 243 * Use of ooo_last_skb avoids the O(Log(N)) rbtree lookup. 244 */ 245 if (mptcp_ooo_try_coalesce(msk, msk->ooo_last_skb, skb)) { 246 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE); 247 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL); 248 return; 249 } 250 251 /* Can avoid an rbtree lookup if we are adding skb after ooo_last_skb */ 252 if (!before64(seq, MPTCP_SKB_CB(msk->ooo_last_skb)->end_seq)) { 253 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOQUEUETAIL); 254 parent = &msk->ooo_last_skb->rbnode; 255 p = &parent->rb_right; 256 goto insert; 257 } 258 259 /* Find place to insert this segment. Handle overlaps on the way. */ 260 parent = NULL; 261 while (*p) { 262 parent = *p; 263 skb1 = rb_to_skb(parent); 264 if (before64(seq, MPTCP_SKB_CB(skb1)->map_seq)) { 265 p = &parent->rb_left; 266 continue; 267 } 268 if (before64(seq, MPTCP_SKB_CB(skb1)->end_seq)) { 269 if (!after64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) { 270 /* All the bits are present. Drop. */ 271 mptcp_drop(sk, skb); 272 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); 273 return; 274 } 275 if (after64(seq, MPTCP_SKB_CB(skb1)->map_seq)) { 276 /* partial overlap: 277 * | skb | 278 * | skb1 | 279 * continue traversing 280 */ 281 } else { 282 /* skb's seq == skb1's seq and skb covers skb1. 283 * Replace skb1 with skb. 284 */ 285 rb_replace_node(&skb1->rbnode, &skb->rbnode, 286 &msk->out_of_order_queue); 287 mptcp_drop(sk, skb1); 288 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); 289 goto merge_right; 290 } 291 } else if (mptcp_ooo_try_coalesce(msk, skb1, skb)) { 292 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_OFOMERGE); 293 return; 294 } 295 p = &parent->rb_right; 296 } 297 298 insert: 299 /* Insert segment into RB tree. */ 300 rb_link_node(&skb->rbnode, parent, p); 301 rb_insert_color(&skb->rbnode, &msk->out_of_order_queue); 302 303 merge_right: 304 /* Remove other segments covered by skb. */ 305 while ((skb1 = skb_rb_next(skb)) != NULL) { 306 if (before64(end_seq, MPTCP_SKB_CB(skb1)->end_seq)) 307 break; 308 rb_erase(&skb1->rbnode, &msk->out_of_order_queue); 309 mptcp_drop(sk, skb1); 310 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); 311 } 312 /* If there is no skb after us, we are the last_skb ! */ 313 if (!skb1) 314 msk->ooo_last_skb = skb; 315 316 end: 317 skb_condense(skb); 318 mptcp_set_owner_r(skb, sk); 319 } 320 321 static bool mptcp_rmem_schedule(struct sock *sk, struct sock *ssk, int size) 322 { 323 struct mptcp_sock *msk = mptcp_sk(sk); 324 int amt, amount; 325 326 if (size < msk->rmem_fwd_alloc) 327 return true; 328 329 amt = sk_mem_pages(size); 330 amount = amt << SK_MEM_QUANTUM_SHIFT; 331 msk->rmem_fwd_alloc += amount; 332 if (!__sk_mem_raise_allocated(sk, size, amt, SK_MEM_RECV)) { 333 if (ssk->sk_forward_alloc < amount) { 334 msk->rmem_fwd_alloc -= amount; 335 return false; 336 } 337 338 ssk->sk_forward_alloc -= amount; 339 } 340 return true; 341 } 342 343 static bool __mptcp_move_skb(struct mptcp_sock *msk, struct sock *ssk, 344 struct sk_buff *skb, unsigned int offset, 345 size_t copy_len) 346 { 347 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 348 struct sock *sk = (struct sock *)msk; 349 struct sk_buff *tail; 350 bool has_rxtstamp; 351 352 __skb_unlink(skb, &ssk->sk_receive_queue); 353 354 skb_ext_reset(skb); 355 skb_orphan(skb); 356 357 /* try to fetch required memory from subflow */ 358 if (!mptcp_rmem_schedule(sk, ssk, skb->truesize)) 359 goto drop; 360 361 has_rxtstamp = TCP_SKB_CB(skb)->has_rxtstamp; 362 363 /* the skb map_seq accounts for the skb offset: 364 * mptcp_subflow_get_mapped_dsn() is based on the current tp->copied_seq 365 * value 366 */ 367 MPTCP_SKB_CB(skb)->map_seq = mptcp_subflow_get_mapped_dsn(subflow); 368 MPTCP_SKB_CB(skb)->end_seq = MPTCP_SKB_CB(skb)->map_seq + copy_len; 369 MPTCP_SKB_CB(skb)->offset = offset; 370 MPTCP_SKB_CB(skb)->has_rxtstamp = has_rxtstamp; 371 372 if (MPTCP_SKB_CB(skb)->map_seq == msk->ack_seq) { 373 /* in sequence */ 374 WRITE_ONCE(msk->ack_seq, msk->ack_seq + copy_len); 375 tail = skb_peek_tail(&sk->sk_receive_queue); 376 if (tail && mptcp_try_coalesce(sk, tail, skb)) 377 return true; 378 379 mptcp_set_owner_r(skb, sk); 380 __skb_queue_tail(&sk->sk_receive_queue, skb); 381 return true; 382 } else if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) { 383 mptcp_data_queue_ofo(msk, skb); 384 return false; 385 } 386 387 /* old data, keep it simple and drop the whole pkt, sender 388 * will retransmit as needed, if needed. 389 */ 390 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); 391 drop: 392 mptcp_drop(sk, skb); 393 return false; 394 } 395 396 static void mptcp_stop_timer(struct sock *sk) 397 { 398 struct inet_connection_sock *icsk = inet_csk(sk); 399 400 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 401 mptcp_sk(sk)->timer_ival = 0; 402 } 403 404 static void mptcp_close_wake_up(struct sock *sk) 405 { 406 if (sock_flag(sk, SOCK_DEAD)) 407 return; 408 409 sk->sk_state_change(sk); 410 if (sk->sk_shutdown == SHUTDOWN_MASK || 411 sk->sk_state == TCP_CLOSE) 412 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_HUP); 413 else 414 sk_wake_async(sk, SOCK_WAKE_WAITD, POLL_IN); 415 } 416 417 static bool mptcp_pending_data_fin_ack(struct sock *sk) 418 { 419 struct mptcp_sock *msk = mptcp_sk(sk); 420 421 return !__mptcp_check_fallback(msk) && 422 ((1 << sk->sk_state) & 423 (TCPF_FIN_WAIT1 | TCPF_CLOSING | TCPF_LAST_ACK)) && 424 msk->write_seq == READ_ONCE(msk->snd_una); 425 } 426 427 static void mptcp_check_data_fin_ack(struct sock *sk) 428 { 429 struct mptcp_sock *msk = mptcp_sk(sk); 430 431 /* Look for an acknowledged DATA_FIN */ 432 if (mptcp_pending_data_fin_ack(sk)) { 433 WRITE_ONCE(msk->snd_data_fin_enable, 0); 434 435 switch (sk->sk_state) { 436 case TCP_FIN_WAIT1: 437 inet_sk_state_store(sk, TCP_FIN_WAIT2); 438 break; 439 case TCP_CLOSING: 440 case TCP_LAST_ACK: 441 inet_sk_state_store(sk, TCP_CLOSE); 442 break; 443 } 444 445 mptcp_close_wake_up(sk); 446 } 447 } 448 449 static bool mptcp_pending_data_fin(struct sock *sk, u64 *seq) 450 { 451 struct mptcp_sock *msk = mptcp_sk(sk); 452 453 if (READ_ONCE(msk->rcv_data_fin) && 454 ((1 << sk->sk_state) & 455 (TCPF_ESTABLISHED | TCPF_FIN_WAIT1 | TCPF_FIN_WAIT2))) { 456 u64 rcv_data_fin_seq = READ_ONCE(msk->rcv_data_fin_seq); 457 458 if (msk->ack_seq == rcv_data_fin_seq) { 459 if (seq) 460 *seq = rcv_data_fin_seq; 461 462 return true; 463 } 464 } 465 466 return false; 467 } 468 469 static void mptcp_set_datafin_timeout(const struct sock *sk) 470 { 471 struct inet_connection_sock *icsk = inet_csk(sk); 472 u32 retransmits; 473 474 retransmits = min_t(u32, icsk->icsk_retransmits, 475 ilog2(TCP_RTO_MAX / TCP_RTO_MIN)); 476 477 mptcp_sk(sk)->timer_ival = TCP_RTO_MIN << retransmits; 478 } 479 480 static void __mptcp_set_timeout(struct sock *sk, long tout) 481 { 482 mptcp_sk(sk)->timer_ival = tout > 0 ? tout : TCP_RTO_MIN; 483 } 484 485 static long mptcp_timeout_from_subflow(const struct mptcp_subflow_context *subflow) 486 { 487 const struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 488 489 return inet_csk(ssk)->icsk_pending && !subflow->stale_count ? 490 inet_csk(ssk)->icsk_timeout - jiffies : 0; 491 } 492 493 static void mptcp_set_timeout(struct sock *sk) 494 { 495 struct mptcp_subflow_context *subflow; 496 long tout = 0; 497 498 mptcp_for_each_subflow(mptcp_sk(sk), subflow) 499 tout = max(tout, mptcp_timeout_from_subflow(subflow)); 500 __mptcp_set_timeout(sk, tout); 501 } 502 503 static inline bool tcp_can_send_ack(const struct sock *ssk) 504 { 505 return !((1 << inet_sk_state_load(ssk)) & 506 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_TIME_WAIT | TCPF_CLOSE | TCPF_LISTEN)); 507 } 508 509 void __mptcp_subflow_send_ack(struct sock *ssk) 510 { 511 if (tcp_can_send_ack(ssk)) 512 tcp_send_ack(ssk); 513 } 514 515 void mptcp_subflow_send_ack(struct sock *ssk) 516 { 517 bool slow; 518 519 slow = lock_sock_fast(ssk); 520 __mptcp_subflow_send_ack(ssk); 521 unlock_sock_fast(ssk, slow); 522 } 523 524 static void mptcp_send_ack(struct mptcp_sock *msk) 525 { 526 struct mptcp_subflow_context *subflow; 527 528 mptcp_for_each_subflow(msk, subflow) 529 mptcp_subflow_send_ack(mptcp_subflow_tcp_sock(subflow)); 530 } 531 532 static void mptcp_subflow_cleanup_rbuf(struct sock *ssk) 533 { 534 bool slow; 535 536 slow = lock_sock_fast(ssk); 537 if (tcp_can_send_ack(ssk)) 538 tcp_cleanup_rbuf(ssk, 1); 539 unlock_sock_fast(ssk, slow); 540 } 541 542 static bool mptcp_subflow_could_cleanup(const struct sock *ssk, bool rx_empty) 543 { 544 const struct inet_connection_sock *icsk = inet_csk(ssk); 545 u8 ack_pending = READ_ONCE(icsk->icsk_ack.pending); 546 const struct tcp_sock *tp = tcp_sk(ssk); 547 548 return (ack_pending & ICSK_ACK_SCHED) && 549 ((READ_ONCE(tp->rcv_nxt) - READ_ONCE(tp->rcv_wup) > 550 READ_ONCE(icsk->icsk_ack.rcv_mss)) || 551 (rx_empty && ack_pending & 552 (ICSK_ACK_PUSHED2 | ICSK_ACK_PUSHED))); 553 } 554 555 static void mptcp_cleanup_rbuf(struct mptcp_sock *msk) 556 { 557 int old_space = READ_ONCE(msk->old_wspace); 558 struct mptcp_subflow_context *subflow; 559 struct sock *sk = (struct sock *)msk; 560 int space = __mptcp_space(sk); 561 bool cleanup, rx_empty; 562 563 cleanup = (space > 0) && (space >= (old_space << 1)); 564 rx_empty = !__mptcp_rmem(sk); 565 566 mptcp_for_each_subflow(msk, subflow) { 567 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 568 569 if (cleanup || mptcp_subflow_could_cleanup(ssk, rx_empty)) 570 mptcp_subflow_cleanup_rbuf(ssk); 571 } 572 } 573 574 static bool mptcp_check_data_fin(struct sock *sk) 575 { 576 struct mptcp_sock *msk = mptcp_sk(sk); 577 u64 rcv_data_fin_seq; 578 bool ret = false; 579 580 if (__mptcp_check_fallback(msk)) 581 return ret; 582 583 /* Need to ack a DATA_FIN received from a peer while this side 584 * of the connection is in ESTABLISHED, FIN_WAIT1, or FIN_WAIT2. 585 * msk->rcv_data_fin was set when parsing the incoming options 586 * at the subflow level and the msk lock was not held, so this 587 * is the first opportunity to act on the DATA_FIN and change 588 * the msk state. 589 * 590 * If we are caught up to the sequence number of the incoming 591 * DATA_FIN, send the DATA_ACK now and do state transition. If 592 * not caught up, do nothing and let the recv code send DATA_ACK 593 * when catching up. 594 */ 595 596 if (mptcp_pending_data_fin(sk, &rcv_data_fin_seq)) { 597 WRITE_ONCE(msk->ack_seq, msk->ack_seq + 1); 598 WRITE_ONCE(msk->rcv_data_fin, 0); 599 600 sk->sk_shutdown |= RCV_SHUTDOWN; 601 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ 602 603 switch (sk->sk_state) { 604 case TCP_ESTABLISHED: 605 inet_sk_state_store(sk, TCP_CLOSE_WAIT); 606 break; 607 case TCP_FIN_WAIT1: 608 inet_sk_state_store(sk, TCP_CLOSING); 609 break; 610 case TCP_FIN_WAIT2: 611 inet_sk_state_store(sk, TCP_CLOSE); 612 break; 613 default: 614 /* Other states not expected */ 615 WARN_ON_ONCE(1); 616 break; 617 } 618 619 ret = true; 620 mptcp_send_ack(msk); 621 mptcp_close_wake_up(sk); 622 } 623 return ret; 624 } 625 626 static bool __mptcp_move_skbs_from_subflow(struct mptcp_sock *msk, 627 struct sock *ssk, 628 unsigned int *bytes) 629 { 630 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 631 struct sock *sk = (struct sock *)msk; 632 unsigned int moved = 0; 633 bool more_data_avail; 634 struct tcp_sock *tp; 635 bool done = false; 636 int sk_rbuf; 637 638 sk_rbuf = READ_ONCE(sk->sk_rcvbuf); 639 640 if (!(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { 641 int ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf); 642 643 if (unlikely(ssk_rbuf > sk_rbuf)) { 644 WRITE_ONCE(sk->sk_rcvbuf, ssk_rbuf); 645 sk_rbuf = ssk_rbuf; 646 } 647 } 648 649 pr_debug("msk=%p ssk=%p", msk, ssk); 650 tp = tcp_sk(ssk); 651 do { 652 u32 map_remaining, offset; 653 u32 seq = tp->copied_seq; 654 struct sk_buff *skb; 655 bool fin; 656 657 /* try to move as much data as available */ 658 map_remaining = subflow->map_data_len - 659 mptcp_subflow_get_map_offset(subflow); 660 661 skb = skb_peek(&ssk->sk_receive_queue); 662 if (!skb) { 663 /* if no data is found, a racing workqueue/recvmsg 664 * already processed the new data, stop here or we 665 * can enter an infinite loop 666 */ 667 if (!moved) 668 done = true; 669 break; 670 } 671 672 if (__mptcp_check_fallback(msk)) { 673 /* if we are running under the workqueue, TCP could have 674 * collapsed skbs between dummy map creation and now 675 * be sure to adjust the size 676 */ 677 map_remaining = skb->len; 678 subflow->map_data_len = skb->len; 679 } 680 681 offset = seq - TCP_SKB_CB(skb)->seq; 682 fin = TCP_SKB_CB(skb)->tcp_flags & TCPHDR_FIN; 683 if (fin) { 684 done = true; 685 seq++; 686 } 687 688 if (offset < skb->len) { 689 size_t len = skb->len - offset; 690 691 if (tp->urg_data) 692 done = true; 693 694 if (__mptcp_move_skb(msk, ssk, skb, offset, len)) 695 moved += len; 696 seq += len; 697 698 if (WARN_ON_ONCE(map_remaining < len)) 699 break; 700 } else { 701 WARN_ON_ONCE(!fin); 702 sk_eat_skb(ssk, skb); 703 done = true; 704 } 705 706 WRITE_ONCE(tp->copied_seq, seq); 707 more_data_avail = mptcp_subflow_data_available(ssk); 708 709 if (atomic_read(&sk->sk_rmem_alloc) > sk_rbuf) { 710 done = true; 711 break; 712 } 713 } while (more_data_avail); 714 715 *bytes += moved; 716 return done; 717 } 718 719 static bool __mptcp_ofo_queue(struct mptcp_sock *msk) 720 { 721 struct sock *sk = (struct sock *)msk; 722 struct sk_buff *skb, *tail; 723 bool moved = false; 724 struct rb_node *p; 725 u64 end_seq; 726 727 p = rb_first(&msk->out_of_order_queue); 728 pr_debug("msk=%p empty=%d", msk, RB_EMPTY_ROOT(&msk->out_of_order_queue)); 729 while (p) { 730 skb = rb_to_skb(p); 731 if (after64(MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq)) 732 break; 733 734 p = rb_next(p); 735 rb_erase(&skb->rbnode, &msk->out_of_order_queue); 736 737 if (unlikely(!after64(MPTCP_SKB_CB(skb)->end_seq, 738 msk->ack_seq))) { 739 mptcp_drop(sk, skb); 740 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_DUPDATA); 741 continue; 742 } 743 744 end_seq = MPTCP_SKB_CB(skb)->end_seq; 745 tail = skb_peek_tail(&sk->sk_receive_queue); 746 if (!tail || !mptcp_ooo_try_coalesce(msk, tail, skb)) { 747 int delta = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq; 748 749 /* skip overlapping data, if any */ 750 pr_debug("uncoalesced seq=%llx ack seq=%llx delta=%d", 751 MPTCP_SKB_CB(skb)->map_seq, msk->ack_seq, 752 delta); 753 MPTCP_SKB_CB(skb)->offset += delta; 754 MPTCP_SKB_CB(skb)->map_seq += delta; 755 __skb_queue_tail(&sk->sk_receive_queue, skb); 756 } 757 msk->ack_seq = end_seq; 758 moved = true; 759 } 760 return moved; 761 } 762 763 /* In most cases we will be able to lock the mptcp socket. If its already 764 * owned, we need to defer to the work queue to avoid ABBA deadlock. 765 */ 766 static bool move_skbs_to_msk(struct mptcp_sock *msk, struct sock *ssk) 767 { 768 struct sock *sk = (struct sock *)msk; 769 unsigned int moved = 0; 770 771 __mptcp_move_skbs_from_subflow(msk, ssk, &moved); 772 __mptcp_ofo_queue(msk); 773 if (unlikely(ssk->sk_err)) { 774 if (!sock_owned_by_user(sk)) 775 __mptcp_error_report(sk); 776 else 777 __set_bit(MPTCP_ERROR_REPORT, &msk->cb_flags); 778 } 779 780 /* If the moves have caught up with the DATA_FIN sequence number 781 * it's time to ack the DATA_FIN and change socket state, but 782 * this is not a good place to change state. Let the workqueue 783 * do it. 784 */ 785 if (mptcp_pending_data_fin(sk, NULL)) 786 mptcp_schedule_work(sk); 787 return moved > 0; 788 } 789 790 void mptcp_data_ready(struct sock *sk, struct sock *ssk) 791 { 792 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 793 struct mptcp_sock *msk = mptcp_sk(sk); 794 int sk_rbuf, ssk_rbuf; 795 796 /* The peer can send data while we are shutting down this 797 * subflow at msk destruction time, but we must avoid enqueuing 798 * more data to the msk receive queue 799 */ 800 if (unlikely(subflow->disposable)) 801 return; 802 803 ssk_rbuf = READ_ONCE(ssk->sk_rcvbuf); 804 sk_rbuf = READ_ONCE(sk->sk_rcvbuf); 805 if (unlikely(ssk_rbuf > sk_rbuf)) 806 sk_rbuf = ssk_rbuf; 807 808 /* over limit? can't append more skbs to msk, Also, no need to wake-up*/ 809 if (__mptcp_rmem(sk) > sk_rbuf) { 810 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RCVPRUNED); 811 return; 812 } 813 814 /* Wake-up the reader only for in-sequence data */ 815 mptcp_data_lock(sk); 816 if (move_skbs_to_msk(msk, ssk)) 817 sk->sk_data_ready(sk); 818 819 mptcp_data_unlock(sk); 820 } 821 822 static bool __mptcp_finish_join(struct mptcp_sock *msk, struct sock *ssk) 823 { 824 struct sock *sk = (struct sock *)msk; 825 826 if (sk->sk_state != TCP_ESTABLISHED) 827 return false; 828 829 /* attach to msk socket only after we are sure we will deal with it 830 * at close time 831 */ 832 if (sk->sk_socket && !ssk->sk_socket) 833 mptcp_sock_graft(ssk, sk->sk_socket); 834 835 mptcp_propagate_sndbuf((struct sock *)msk, ssk); 836 mptcp_sockopt_sync_locked(msk, ssk); 837 return true; 838 } 839 840 static void __mptcp_flush_join_list(struct sock *sk) 841 { 842 struct mptcp_subflow_context *tmp, *subflow; 843 struct mptcp_sock *msk = mptcp_sk(sk); 844 845 list_for_each_entry_safe(subflow, tmp, &msk->join_list, node) { 846 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 847 bool slow = lock_sock_fast(ssk); 848 849 list_move_tail(&subflow->node, &msk->conn_list); 850 if (!__mptcp_finish_join(msk, ssk)) 851 mptcp_subflow_reset(ssk); 852 unlock_sock_fast(ssk, slow); 853 } 854 } 855 856 static bool mptcp_timer_pending(struct sock *sk) 857 { 858 return timer_pending(&inet_csk(sk)->icsk_retransmit_timer); 859 } 860 861 static void mptcp_reset_timer(struct sock *sk) 862 { 863 struct inet_connection_sock *icsk = inet_csk(sk); 864 unsigned long tout; 865 866 /* prevent rescheduling on close */ 867 if (unlikely(inet_sk_state_load(sk) == TCP_CLOSE)) 868 return; 869 870 tout = mptcp_sk(sk)->timer_ival; 871 sk_reset_timer(sk, &icsk->icsk_retransmit_timer, jiffies + tout); 872 } 873 874 bool mptcp_schedule_work(struct sock *sk) 875 { 876 if (inet_sk_state_load(sk) != TCP_CLOSE && 877 schedule_work(&mptcp_sk(sk)->work)) { 878 /* each subflow already holds a reference to the sk, and the 879 * workqueue is invoked by a subflow, so sk can't go away here. 880 */ 881 sock_hold(sk); 882 return true; 883 } 884 return false; 885 } 886 887 void mptcp_subflow_eof(struct sock *sk) 888 { 889 if (!test_and_set_bit(MPTCP_WORK_EOF, &mptcp_sk(sk)->flags)) 890 mptcp_schedule_work(sk); 891 } 892 893 static void mptcp_check_for_eof(struct mptcp_sock *msk) 894 { 895 struct mptcp_subflow_context *subflow; 896 struct sock *sk = (struct sock *)msk; 897 int receivers = 0; 898 899 mptcp_for_each_subflow(msk, subflow) 900 receivers += !subflow->rx_eof; 901 if (receivers) 902 return; 903 904 if (!(sk->sk_shutdown & RCV_SHUTDOWN)) { 905 /* hopefully temporary hack: propagate shutdown status 906 * to msk, when all subflows agree on it 907 */ 908 sk->sk_shutdown |= RCV_SHUTDOWN; 909 910 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ 911 sk->sk_data_ready(sk); 912 } 913 914 switch (sk->sk_state) { 915 case TCP_ESTABLISHED: 916 inet_sk_state_store(sk, TCP_CLOSE_WAIT); 917 break; 918 case TCP_FIN_WAIT1: 919 inet_sk_state_store(sk, TCP_CLOSING); 920 break; 921 case TCP_FIN_WAIT2: 922 inet_sk_state_store(sk, TCP_CLOSE); 923 break; 924 default: 925 return; 926 } 927 mptcp_close_wake_up(sk); 928 } 929 930 static struct sock *mptcp_subflow_recv_lookup(const struct mptcp_sock *msk) 931 { 932 struct mptcp_subflow_context *subflow; 933 struct sock *sk = (struct sock *)msk; 934 935 sock_owned_by_me(sk); 936 937 mptcp_for_each_subflow(msk, subflow) { 938 if (READ_ONCE(subflow->data_avail)) 939 return mptcp_subflow_tcp_sock(subflow); 940 } 941 942 return NULL; 943 } 944 945 static bool mptcp_skb_can_collapse_to(u64 write_seq, 946 const struct sk_buff *skb, 947 const struct mptcp_ext *mpext) 948 { 949 if (!tcp_skb_can_collapse_to(skb)) 950 return false; 951 952 /* can collapse only if MPTCP level sequence is in order and this 953 * mapping has not been xmitted yet 954 */ 955 return mpext && mpext->data_seq + mpext->data_len == write_seq && 956 !mpext->frozen; 957 } 958 959 /* we can append data to the given data frag if: 960 * - there is space available in the backing page_frag 961 * - the data frag tail matches the current page_frag free offset 962 * - the data frag end sequence number matches the current write seq 963 */ 964 static bool mptcp_frag_can_collapse_to(const struct mptcp_sock *msk, 965 const struct page_frag *pfrag, 966 const struct mptcp_data_frag *df) 967 { 968 return df && pfrag->page == df->page && 969 pfrag->size - pfrag->offset > 0 && 970 pfrag->offset == (df->offset + df->data_len) && 971 df->data_seq + df->data_len == msk->write_seq; 972 } 973 974 static void __mptcp_mem_reclaim_partial(struct sock *sk) 975 { 976 int reclaimable = mptcp_sk(sk)->rmem_fwd_alloc - sk_unused_reserved_mem(sk); 977 978 lockdep_assert_held_once(&sk->sk_lock.slock); 979 980 if (reclaimable > SK_MEM_QUANTUM) 981 __mptcp_rmem_reclaim(sk, reclaimable - 1); 982 983 sk_mem_reclaim_partial(sk); 984 } 985 986 static void mptcp_mem_reclaim_partial(struct sock *sk) 987 { 988 mptcp_data_lock(sk); 989 __mptcp_mem_reclaim_partial(sk); 990 mptcp_data_unlock(sk); 991 } 992 993 static void dfrag_uncharge(struct sock *sk, int len) 994 { 995 sk_mem_uncharge(sk, len); 996 sk_wmem_queued_add(sk, -len); 997 } 998 999 static void dfrag_clear(struct sock *sk, struct mptcp_data_frag *dfrag) 1000 { 1001 int len = dfrag->data_len + dfrag->overhead; 1002 1003 list_del(&dfrag->list); 1004 dfrag_uncharge(sk, len); 1005 put_page(dfrag->page); 1006 } 1007 1008 static void __mptcp_clean_una(struct sock *sk) 1009 { 1010 struct mptcp_sock *msk = mptcp_sk(sk); 1011 struct mptcp_data_frag *dtmp, *dfrag; 1012 bool cleaned = false; 1013 u64 snd_una; 1014 1015 /* on fallback we just need to ignore snd_una, as this is really 1016 * plain TCP 1017 */ 1018 if (__mptcp_check_fallback(msk)) 1019 msk->snd_una = READ_ONCE(msk->snd_nxt); 1020 1021 snd_una = msk->snd_una; 1022 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) { 1023 if (after64(dfrag->data_seq + dfrag->data_len, snd_una)) 1024 break; 1025 1026 if (unlikely(dfrag == msk->first_pending)) { 1027 /* in recovery mode can see ack after the current snd head */ 1028 if (WARN_ON_ONCE(!msk->recovery)) 1029 break; 1030 1031 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); 1032 } 1033 1034 dfrag_clear(sk, dfrag); 1035 cleaned = true; 1036 } 1037 1038 dfrag = mptcp_rtx_head(sk); 1039 if (dfrag && after64(snd_una, dfrag->data_seq)) { 1040 u64 delta = snd_una - dfrag->data_seq; 1041 1042 /* prevent wrap around in recovery mode */ 1043 if (unlikely(delta > dfrag->already_sent)) { 1044 if (WARN_ON_ONCE(!msk->recovery)) 1045 goto out; 1046 if (WARN_ON_ONCE(delta > dfrag->data_len)) 1047 goto out; 1048 dfrag->already_sent += delta - dfrag->already_sent; 1049 } 1050 1051 dfrag->data_seq += delta; 1052 dfrag->offset += delta; 1053 dfrag->data_len -= delta; 1054 dfrag->already_sent -= delta; 1055 1056 dfrag_uncharge(sk, delta); 1057 cleaned = true; 1058 } 1059 1060 /* all retransmitted data acked, recovery completed */ 1061 if (unlikely(msk->recovery) && after64(msk->snd_una, msk->recovery_snd_nxt)) 1062 msk->recovery = false; 1063 1064 out: 1065 if (cleaned && tcp_under_memory_pressure(sk)) 1066 __mptcp_mem_reclaim_partial(sk); 1067 1068 if (snd_una == READ_ONCE(msk->snd_nxt) && 1069 snd_una == READ_ONCE(msk->write_seq)) { 1070 if (mptcp_timer_pending(sk) && !mptcp_data_fin_enabled(msk)) 1071 mptcp_stop_timer(sk); 1072 } else { 1073 mptcp_reset_timer(sk); 1074 } 1075 } 1076 1077 static void __mptcp_clean_una_wakeup(struct sock *sk) 1078 { 1079 lockdep_assert_held_once(&sk->sk_lock.slock); 1080 1081 __mptcp_clean_una(sk); 1082 mptcp_write_space(sk); 1083 } 1084 1085 static void mptcp_clean_una_wakeup(struct sock *sk) 1086 { 1087 mptcp_data_lock(sk); 1088 __mptcp_clean_una_wakeup(sk); 1089 mptcp_data_unlock(sk); 1090 } 1091 1092 static void mptcp_enter_memory_pressure(struct sock *sk) 1093 { 1094 struct mptcp_subflow_context *subflow; 1095 struct mptcp_sock *msk = mptcp_sk(sk); 1096 bool first = true; 1097 1098 sk_stream_moderate_sndbuf(sk); 1099 mptcp_for_each_subflow(msk, subflow) { 1100 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 1101 1102 if (first) 1103 tcp_enter_memory_pressure(ssk); 1104 sk_stream_moderate_sndbuf(ssk); 1105 first = false; 1106 } 1107 } 1108 1109 /* ensure we get enough memory for the frag hdr, beyond some minimal amount of 1110 * data 1111 */ 1112 static bool mptcp_page_frag_refill(struct sock *sk, struct page_frag *pfrag) 1113 { 1114 if (likely(skb_page_frag_refill(32U + sizeof(struct mptcp_data_frag), 1115 pfrag, sk->sk_allocation))) 1116 return true; 1117 1118 mptcp_enter_memory_pressure(sk); 1119 return false; 1120 } 1121 1122 static struct mptcp_data_frag * 1123 mptcp_carve_data_frag(const struct mptcp_sock *msk, struct page_frag *pfrag, 1124 int orig_offset) 1125 { 1126 int offset = ALIGN(orig_offset, sizeof(long)); 1127 struct mptcp_data_frag *dfrag; 1128 1129 dfrag = (struct mptcp_data_frag *)(page_to_virt(pfrag->page) + offset); 1130 dfrag->data_len = 0; 1131 dfrag->data_seq = msk->write_seq; 1132 dfrag->overhead = offset - orig_offset + sizeof(struct mptcp_data_frag); 1133 dfrag->offset = offset + sizeof(struct mptcp_data_frag); 1134 dfrag->already_sent = 0; 1135 dfrag->page = pfrag->page; 1136 1137 return dfrag; 1138 } 1139 1140 struct mptcp_sendmsg_info { 1141 int mss_now; 1142 int size_goal; 1143 u16 limit; 1144 u16 sent; 1145 unsigned int flags; 1146 bool data_lock_held; 1147 }; 1148 1149 static int mptcp_check_allowed_size(const struct mptcp_sock *msk, struct sock *ssk, 1150 u64 data_seq, int avail_size) 1151 { 1152 u64 window_end = mptcp_wnd_end(msk); 1153 u64 mptcp_snd_wnd; 1154 1155 if (__mptcp_check_fallback(msk)) 1156 return avail_size; 1157 1158 mptcp_snd_wnd = window_end - data_seq; 1159 avail_size = min_t(unsigned int, mptcp_snd_wnd, avail_size); 1160 1161 if (unlikely(tcp_sk(ssk)->snd_wnd < mptcp_snd_wnd)) { 1162 tcp_sk(ssk)->snd_wnd = min_t(u64, U32_MAX, mptcp_snd_wnd); 1163 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_SNDWNDSHARED); 1164 } 1165 1166 return avail_size; 1167 } 1168 1169 static bool __mptcp_add_ext(struct sk_buff *skb, gfp_t gfp) 1170 { 1171 struct skb_ext *mpext = __skb_ext_alloc(gfp); 1172 1173 if (!mpext) 1174 return false; 1175 __skb_ext_set(skb, SKB_EXT_MPTCP, mpext); 1176 return true; 1177 } 1178 1179 static struct sk_buff *__mptcp_do_alloc_tx_skb(struct sock *sk, gfp_t gfp) 1180 { 1181 struct sk_buff *skb; 1182 1183 skb = alloc_skb_fclone(MAX_TCP_HEADER, gfp); 1184 if (likely(skb)) { 1185 if (likely(__mptcp_add_ext(skb, gfp))) { 1186 skb_reserve(skb, MAX_TCP_HEADER); 1187 skb->ip_summed = CHECKSUM_PARTIAL; 1188 INIT_LIST_HEAD(&skb->tcp_tsorted_anchor); 1189 return skb; 1190 } 1191 __kfree_skb(skb); 1192 } else { 1193 mptcp_enter_memory_pressure(sk); 1194 } 1195 return NULL; 1196 } 1197 1198 static struct sk_buff *__mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, gfp_t gfp) 1199 { 1200 struct sk_buff *skb; 1201 1202 skb = __mptcp_do_alloc_tx_skb(sk, gfp); 1203 if (!skb) 1204 return NULL; 1205 1206 if (likely(sk_wmem_schedule(ssk, skb->truesize))) { 1207 tcp_skb_entail(ssk, skb); 1208 return skb; 1209 } 1210 tcp_skb_tsorted_anchor_cleanup(skb); 1211 kfree_skb(skb); 1212 return NULL; 1213 } 1214 1215 static struct sk_buff *mptcp_alloc_tx_skb(struct sock *sk, struct sock *ssk, bool data_lock_held) 1216 { 1217 gfp_t gfp = data_lock_held ? GFP_ATOMIC : sk->sk_allocation; 1218 1219 if (unlikely(tcp_under_memory_pressure(sk))) { 1220 if (data_lock_held) 1221 __mptcp_mem_reclaim_partial(sk); 1222 else 1223 mptcp_mem_reclaim_partial(sk); 1224 } 1225 return __mptcp_alloc_tx_skb(sk, ssk, gfp); 1226 } 1227 1228 /* note: this always recompute the csum on the whole skb, even 1229 * if we just appended a single frag. More status info needed 1230 */ 1231 static void mptcp_update_data_checksum(struct sk_buff *skb, int added) 1232 { 1233 struct mptcp_ext *mpext = mptcp_get_ext(skb); 1234 __wsum csum = ~csum_unfold(mpext->csum); 1235 int offset = skb->len - added; 1236 1237 mpext->csum = csum_fold(csum_block_add(csum, skb_checksum(skb, offset, added, 0), offset)); 1238 } 1239 1240 static void mptcp_update_infinite_map(struct mptcp_sock *msk, 1241 struct sock *ssk, 1242 struct mptcp_ext *mpext) 1243 { 1244 if (!mpext) 1245 return; 1246 1247 mpext->infinite_map = 1; 1248 mpext->data_len = 0; 1249 1250 MPTCP_INC_STATS(sock_net(ssk), MPTCP_MIB_INFINITEMAPTX); 1251 mptcp_subflow_ctx(ssk)->send_infinite_map = 0; 1252 pr_fallback(msk); 1253 mptcp_do_fallback(ssk); 1254 } 1255 1256 static int mptcp_sendmsg_frag(struct sock *sk, struct sock *ssk, 1257 struct mptcp_data_frag *dfrag, 1258 struct mptcp_sendmsg_info *info) 1259 { 1260 u64 data_seq = dfrag->data_seq + info->sent; 1261 int offset = dfrag->offset + info->sent; 1262 struct mptcp_sock *msk = mptcp_sk(sk); 1263 bool zero_window_probe = false; 1264 struct mptcp_ext *mpext = NULL; 1265 bool can_coalesce = false; 1266 bool reuse_skb = true; 1267 struct sk_buff *skb; 1268 size_t copy; 1269 int i; 1270 1271 pr_debug("msk=%p ssk=%p sending dfrag at seq=%llu len=%u already sent=%u", 1272 msk, ssk, dfrag->data_seq, dfrag->data_len, info->sent); 1273 1274 if (WARN_ON_ONCE(info->sent > info->limit || 1275 info->limit > dfrag->data_len)) 1276 return 0; 1277 1278 /* compute send limit */ 1279 info->mss_now = tcp_send_mss(ssk, &info->size_goal, info->flags); 1280 copy = info->size_goal; 1281 1282 skb = tcp_write_queue_tail(ssk); 1283 if (skb && copy > skb->len) { 1284 /* Limit the write to the size available in the 1285 * current skb, if any, so that we create at most a new skb. 1286 * Explicitly tells TCP internals to avoid collapsing on later 1287 * queue management operation, to avoid breaking the ext <-> 1288 * SSN association set here 1289 */ 1290 mpext = skb_ext_find(skb, SKB_EXT_MPTCP); 1291 if (!mptcp_skb_can_collapse_to(data_seq, skb, mpext)) { 1292 TCP_SKB_CB(skb)->eor = 1; 1293 goto alloc_skb; 1294 } 1295 1296 i = skb_shinfo(skb)->nr_frags; 1297 can_coalesce = skb_can_coalesce(skb, i, dfrag->page, offset); 1298 if (!can_coalesce && i >= sysctl_max_skb_frags) { 1299 tcp_mark_push(tcp_sk(ssk), skb); 1300 goto alloc_skb; 1301 } 1302 1303 copy -= skb->len; 1304 } else { 1305 alloc_skb: 1306 skb = mptcp_alloc_tx_skb(sk, ssk, info->data_lock_held); 1307 if (!skb) 1308 return -ENOMEM; 1309 1310 i = skb_shinfo(skb)->nr_frags; 1311 reuse_skb = false; 1312 mpext = skb_ext_find(skb, SKB_EXT_MPTCP); 1313 } 1314 1315 /* Zero window and all data acked? Probe. */ 1316 copy = mptcp_check_allowed_size(msk, ssk, data_seq, copy); 1317 if (copy == 0) { 1318 u64 snd_una = READ_ONCE(msk->snd_una); 1319 1320 if (snd_una != msk->snd_nxt) { 1321 tcp_remove_empty_skb(ssk); 1322 return 0; 1323 } 1324 1325 zero_window_probe = true; 1326 data_seq = snd_una - 1; 1327 copy = 1; 1328 1329 /* all mptcp-level data is acked, no skbs should be present into the 1330 * ssk write queue 1331 */ 1332 WARN_ON_ONCE(reuse_skb); 1333 } 1334 1335 copy = min_t(size_t, copy, info->limit - info->sent); 1336 if (!sk_wmem_schedule(ssk, copy)) { 1337 tcp_remove_empty_skb(ssk); 1338 return -ENOMEM; 1339 } 1340 1341 if (can_coalesce) { 1342 skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], copy); 1343 } else { 1344 get_page(dfrag->page); 1345 skb_fill_page_desc(skb, i, dfrag->page, offset, copy); 1346 } 1347 1348 skb->len += copy; 1349 skb->data_len += copy; 1350 skb->truesize += copy; 1351 sk_wmem_queued_add(ssk, copy); 1352 sk_mem_charge(ssk, copy); 1353 WRITE_ONCE(tcp_sk(ssk)->write_seq, tcp_sk(ssk)->write_seq + copy); 1354 TCP_SKB_CB(skb)->end_seq += copy; 1355 tcp_skb_pcount_set(skb, 0); 1356 1357 /* on skb reuse we just need to update the DSS len */ 1358 if (reuse_skb) { 1359 TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_PSH; 1360 mpext->data_len += copy; 1361 WARN_ON_ONCE(zero_window_probe); 1362 goto out; 1363 } 1364 1365 memset(mpext, 0, sizeof(*mpext)); 1366 mpext->data_seq = data_seq; 1367 mpext->subflow_seq = mptcp_subflow_ctx(ssk)->rel_write_seq; 1368 mpext->data_len = copy; 1369 mpext->use_map = 1; 1370 mpext->dsn64 = 1; 1371 1372 pr_debug("data_seq=%llu subflow_seq=%u data_len=%u dsn64=%d", 1373 mpext->data_seq, mpext->subflow_seq, mpext->data_len, 1374 mpext->dsn64); 1375 1376 if (zero_window_probe) { 1377 mptcp_subflow_ctx(ssk)->rel_write_seq += copy; 1378 mpext->frozen = 1; 1379 if (READ_ONCE(msk->csum_enabled)) 1380 mptcp_update_data_checksum(skb, copy); 1381 tcp_push_pending_frames(ssk); 1382 return 0; 1383 } 1384 out: 1385 if (READ_ONCE(msk->csum_enabled)) 1386 mptcp_update_data_checksum(skb, copy); 1387 if (mptcp_subflow_ctx(ssk)->send_infinite_map) 1388 mptcp_update_infinite_map(msk, ssk, mpext); 1389 trace_mptcp_sendmsg_frag(mpext); 1390 mptcp_subflow_ctx(ssk)->rel_write_seq += copy; 1391 return copy; 1392 } 1393 1394 #define MPTCP_SEND_BURST_SIZE ((1 << 16) - \ 1395 sizeof(struct tcphdr) - \ 1396 MAX_TCP_OPTION_SPACE - \ 1397 sizeof(struct ipv6hdr) - \ 1398 sizeof(struct frag_hdr)) 1399 1400 struct subflow_send_info { 1401 struct sock *ssk; 1402 u64 linger_time; 1403 }; 1404 1405 void mptcp_subflow_set_active(struct mptcp_subflow_context *subflow) 1406 { 1407 if (!subflow->stale) 1408 return; 1409 1410 subflow->stale = 0; 1411 MPTCP_INC_STATS(sock_net(mptcp_subflow_tcp_sock(subflow)), MPTCP_MIB_SUBFLOWRECOVER); 1412 } 1413 1414 bool mptcp_subflow_active(struct mptcp_subflow_context *subflow) 1415 { 1416 if (unlikely(subflow->stale)) { 1417 u32 rcv_tstamp = READ_ONCE(tcp_sk(mptcp_subflow_tcp_sock(subflow))->rcv_tstamp); 1418 1419 if (subflow->stale_rcv_tstamp == rcv_tstamp) 1420 return false; 1421 1422 mptcp_subflow_set_active(subflow); 1423 } 1424 return __mptcp_subflow_active(subflow); 1425 } 1426 1427 #define SSK_MODE_ACTIVE 0 1428 #define SSK_MODE_BACKUP 1 1429 #define SSK_MODE_MAX 2 1430 1431 /* implement the mptcp packet scheduler; 1432 * returns the subflow that will transmit the next DSS 1433 * additionally updates the rtx timeout 1434 */ 1435 static struct sock *mptcp_subflow_get_send(struct mptcp_sock *msk) 1436 { 1437 struct subflow_send_info send_info[SSK_MODE_MAX]; 1438 struct mptcp_subflow_context *subflow; 1439 struct sock *sk = (struct sock *)msk; 1440 u32 pace, burst, wmem; 1441 int i, nr_active = 0; 1442 struct sock *ssk; 1443 u64 linger_time; 1444 long tout = 0; 1445 1446 sock_owned_by_me(sk); 1447 1448 if (__mptcp_check_fallback(msk)) { 1449 if (!msk->first) 1450 return NULL; 1451 return sk_stream_memory_free(msk->first) ? msk->first : NULL; 1452 } 1453 1454 /* re-use last subflow, if the burst allow that */ 1455 if (msk->last_snd && msk->snd_burst > 0 && 1456 sk_stream_memory_free(msk->last_snd) && 1457 mptcp_subflow_active(mptcp_subflow_ctx(msk->last_snd))) { 1458 mptcp_set_timeout(sk); 1459 return msk->last_snd; 1460 } 1461 1462 /* pick the subflow with the lower wmem/wspace ratio */ 1463 for (i = 0; i < SSK_MODE_MAX; ++i) { 1464 send_info[i].ssk = NULL; 1465 send_info[i].linger_time = -1; 1466 } 1467 1468 mptcp_for_each_subflow(msk, subflow) { 1469 trace_mptcp_subflow_get_send(subflow); 1470 ssk = mptcp_subflow_tcp_sock(subflow); 1471 if (!mptcp_subflow_active(subflow)) 1472 continue; 1473 1474 tout = max(tout, mptcp_timeout_from_subflow(subflow)); 1475 nr_active += !subflow->backup; 1476 pace = subflow->avg_pacing_rate; 1477 if (unlikely(!pace)) { 1478 /* init pacing rate from socket */ 1479 subflow->avg_pacing_rate = READ_ONCE(ssk->sk_pacing_rate); 1480 pace = subflow->avg_pacing_rate; 1481 if (!pace) 1482 continue; 1483 } 1484 1485 linger_time = div_u64((u64)READ_ONCE(ssk->sk_wmem_queued) << 32, pace); 1486 if (linger_time < send_info[subflow->backup].linger_time) { 1487 send_info[subflow->backup].ssk = ssk; 1488 send_info[subflow->backup].linger_time = linger_time; 1489 } 1490 } 1491 __mptcp_set_timeout(sk, tout); 1492 1493 /* pick the best backup if no other subflow is active */ 1494 if (!nr_active) 1495 send_info[SSK_MODE_ACTIVE].ssk = send_info[SSK_MODE_BACKUP].ssk; 1496 1497 /* According to the blest algorithm, to avoid HoL blocking for the 1498 * faster flow, we need to: 1499 * - estimate the faster flow linger time 1500 * - use the above to estimate the amount of byte transferred 1501 * by the faster flow 1502 * - check that the amount of queued data is greter than the above, 1503 * otherwise do not use the picked, slower, subflow 1504 * We select the subflow with the shorter estimated time to flush 1505 * the queued mem, which basically ensure the above. We just need 1506 * to check that subflow has a non empty cwin. 1507 */ 1508 ssk = send_info[SSK_MODE_ACTIVE].ssk; 1509 if (!ssk || !sk_stream_memory_free(ssk)) 1510 return NULL; 1511 1512 burst = min_t(int, MPTCP_SEND_BURST_SIZE, mptcp_wnd_end(msk) - msk->snd_nxt); 1513 wmem = READ_ONCE(ssk->sk_wmem_queued); 1514 if (!burst) { 1515 msk->last_snd = NULL; 1516 return ssk; 1517 } 1518 1519 subflow = mptcp_subflow_ctx(ssk); 1520 subflow->avg_pacing_rate = div_u64((u64)subflow->avg_pacing_rate * wmem + 1521 READ_ONCE(ssk->sk_pacing_rate) * burst, 1522 burst + wmem); 1523 msk->last_snd = ssk; 1524 msk->snd_burst = burst; 1525 return ssk; 1526 } 1527 1528 static void mptcp_push_release(struct sock *ssk, struct mptcp_sendmsg_info *info) 1529 { 1530 tcp_push(ssk, 0, info->mss_now, tcp_sk(ssk)->nonagle, info->size_goal); 1531 release_sock(ssk); 1532 } 1533 1534 static void mptcp_update_post_push(struct mptcp_sock *msk, 1535 struct mptcp_data_frag *dfrag, 1536 u32 sent) 1537 { 1538 u64 snd_nxt_new = dfrag->data_seq; 1539 1540 dfrag->already_sent += sent; 1541 1542 msk->snd_burst -= sent; 1543 1544 snd_nxt_new += dfrag->already_sent; 1545 1546 /* snd_nxt_new can be smaller than snd_nxt in case mptcp 1547 * is recovering after a failover. In that event, this re-sends 1548 * old segments. 1549 * 1550 * Thus compute snd_nxt_new candidate based on 1551 * the dfrag->data_seq that was sent and the data 1552 * that has been handed to the subflow for transmission 1553 * and skip update in case it was old dfrag. 1554 */ 1555 if (likely(after64(snd_nxt_new, msk->snd_nxt))) 1556 msk->snd_nxt = snd_nxt_new; 1557 } 1558 1559 void mptcp_check_and_set_pending(struct sock *sk) 1560 { 1561 if (mptcp_send_head(sk)) 1562 mptcp_sk(sk)->push_pending |= BIT(MPTCP_PUSH_PENDING); 1563 } 1564 1565 void __mptcp_push_pending(struct sock *sk, unsigned int flags) 1566 { 1567 struct sock *prev_ssk = NULL, *ssk = NULL; 1568 struct mptcp_sock *msk = mptcp_sk(sk); 1569 struct mptcp_sendmsg_info info = { 1570 .flags = flags, 1571 }; 1572 struct mptcp_data_frag *dfrag; 1573 int len, copied = 0; 1574 1575 while ((dfrag = mptcp_send_head(sk))) { 1576 info.sent = dfrag->already_sent; 1577 info.limit = dfrag->data_len; 1578 len = dfrag->data_len - dfrag->already_sent; 1579 while (len > 0) { 1580 int ret = 0; 1581 1582 prev_ssk = ssk; 1583 ssk = mptcp_subflow_get_send(msk); 1584 1585 /* First check. If the ssk has changed since 1586 * the last round, release prev_ssk 1587 */ 1588 if (ssk != prev_ssk && prev_ssk) 1589 mptcp_push_release(prev_ssk, &info); 1590 if (!ssk) 1591 goto out; 1592 1593 /* Need to lock the new subflow only if different 1594 * from the previous one, otherwise we are still 1595 * helding the relevant lock 1596 */ 1597 if (ssk != prev_ssk) 1598 lock_sock(ssk); 1599 1600 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); 1601 if (ret <= 0) { 1602 mptcp_push_release(ssk, &info); 1603 goto out; 1604 } 1605 1606 info.sent += ret; 1607 copied += ret; 1608 len -= ret; 1609 1610 mptcp_update_post_push(msk, dfrag, ret); 1611 } 1612 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); 1613 } 1614 1615 /* at this point we held the socket lock for the last subflow we used */ 1616 if (ssk) 1617 mptcp_push_release(ssk, &info); 1618 1619 out: 1620 /* ensure the rtx timer is running */ 1621 if (!mptcp_timer_pending(sk)) 1622 mptcp_reset_timer(sk); 1623 if (copied) 1624 __mptcp_check_send_data_fin(sk); 1625 } 1626 1627 static void __mptcp_subflow_push_pending(struct sock *sk, struct sock *ssk) 1628 { 1629 struct mptcp_sock *msk = mptcp_sk(sk); 1630 struct mptcp_sendmsg_info info = { 1631 .data_lock_held = true, 1632 }; 1633 struct mptcp_data_frag *dfrag; 1634 struct sock *xmit_ssk; 1635 int len, copied = 0; 1636 bool first = true; 1637 1638 info.flags = 0; 1639 while ((dfrag = mptcp_send_head(sk))) { 1640 info.sent = dfrag->already_sent; 1641 info.limit = dfrag->data_len; 1642 len = dfrag->data_len - dfrag->already_sent; 1643 while (len > 0) { 1644 int ret = 0; 1645 1646 /* the caller already invoked the packet scheduler, 1647 * check for a different subflow usage only after 1648 * spooling the first chunk of data 1649 */ 1650 xmit_ssk = first ? ssk : mptcp_subflow_get_send(mptcp_sk(sk)); 1651 if (!xmit_ssk) 1652 goto out; 1653 if (xmit_ssk != ssk) { 1654 mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), 1655 MPTCP_DELEGATE_SEND); 1656 goto out; 1657 } 1658 1659 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); 1660 if (ret <= 0) 1661 goto out; 1662 1663 info.sent += ret; 1664 copied += ret; 1665 len -= ret; 1666 first = false; 1667 1668 mptcp_update_post_push(msk, dfrag, ret); 1669 } 1670 WRITE_ONCE(msk->first_pending, mptcp_send_next(sk)); 1671 } 1672 1673 out: 1674 /* __mptcp_alloc_tx_skb could have released some wmem and we are 1675 * not going to flush it via release_sock() 1676 */ 1677 if (copied) { 1678 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, 1679 info.size_goal); 1680 if (!mptcp_timer_pending(sk)) 1681 mptcp_reset_timer(sk); 1682 1683 if (msk->snd_data_fin_enable && 1684 msk->snd_nxt + 1 == msk->write_seq) 1685 mptcp_schedule_work(sk); 1686 } 1687 } 1688 1689 static void mptcp_set_nospace(struct sock *sk) 1690 { 1691 /* enable autotune */ 1692 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags); 1693 1694 /* will be cleared on avail space */ 1695 set_bit(MPTCP_NOSPACE, &mptcp_sk(sk)->flags); 1696 } 1697 1698 static int mptcp_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) 1699 { 1700 struct mptcp_sock *msk = mptcp_sk(sk); 1701 struct page_frag *pfrag; 1702 size_t copied = 0; 1703 int ret = 0; 1704 long timeo; 1705 1706 /* we don't support FASTOPEN yet */ 1707 if (msg->msg_flags & MSG_FASTOPEN) 1708 return -EOPNOTSUPP; 1709 1710 /* silently ignore everything else */ 1711 msg->msg_flags &= MSG_MORE | MSG_DONTWAIT | MSG_NOSIGNAL; 1712 1713 lock_sock(sk); 1714 1715 timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT); 1716 1717 if ((1 << sk->sk_state) & ~(TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)) { 1718 ret = sk_stream_wait_connect(sk, &timeo); 1719 if (ret) 1720 goto out; 1721 } 1722 1723 pfrag = sk_page_frag(sk); 1724 1725 while (msg_data_left(msg)) { 1726 int total_ts, frag_truesize = 0; 1727 struct mptcp_data_frag *dfrag; 1728 bool dfrag_collapsed; 1729 size_t psize, offset; 1730 1731 if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN)) { 1732 ret = -EPIPE; 1733 goto out; 1734 } 1735 1736 /* reuse tail pfrag, if possible, or carve a new one from the 1737 * page allocator 1738 */ 1739 dfrag = mptcp_pending_tail(sk); 1740 dfrag_collapsed = mptcp_frag_can_collapse_to(msk, pfrag, dfrag); 1741 if (!dfrag_collapsed) { 1742 if (!sk_stream_memory_free(sk)) 1743 goto wait_for_memory; 1744 1745 if (!mptcp_page_frag_refill(sk, pfrag)) 1746 goto wait_for_memory; 1747 1748 dfrag = mptcp_carve_data_frag(msk, pfrag, pfrag->offset); 1749 frag_truesize = dfrag->overhead; 1750 } 1751 1752 /* we do not bound vs wspace, to allow a single packet. 1753 * memory accounting will prevent execessive memory usage 1754 * anyway 1755 */ 1756 offset = dfrag->offset + dfrag->data_len; 1757 psize = pfrag->size - offset; 1758 psize = min_t(size_t, psize, msg_data_left(msg)); 1759 total_ts = psize + frag_truesize; 1760 1761 if (!sk_wmem_schedule(sk, total_ts)) 1762 goto wait_for_memory; 1763 1764 if (copy_page_from_iter(dfrag->page, offset, psize, 1765 &msg->msg_iter) != psize) { 1766 ret = -EFAULT; 1767 goto out; 1768 } 1769 1770 /* data successfully copied into the write queue */ 1771 sk->sk_forward_alloc -= total_ts; 1772 copied += psize; 1773 dfrag->data_len += psize; 1774 frag_truesize += psize; 1775 pfrag->offset += frag_truesize; 1776 WRITE_ONCE(msk->write_seq, msk->write_seq + psize); 1777 1778 /* charge data on mptcp pending queue to the msk socket 1779 * Note: we charge such data both to sk and ssk 1780 */ 1781 sk_wmem_queued_add(sk, frag_truesize); 1782 if (!dfrag_collapsed) { 1783 get_page(dfrag->page); 1784 list_add_tail(&dfrag->list, &msk->rtx_queue); 1785 if (!msk->first_pending) 1786 WRITE_ONCE(msk->first_pending, dfrag); 1787 } 1788 pr_debug("msk=%p dfrag at seq=%llu len=%u sent=%u new=%d", msk, 1789 dfrag->data_seq, dfrag->data_len, dfrag->already_sent, 1790 !dfrag_collapsed); 1791 1792 continue; 1793 1794 wait_for_memory: 1795 mptcp_set_nospace(sk); 1796 __mptcp_push_pending(sk, msg->msg_flags); 1797 ret = sk_stream_wait_memory(sk, &timeo); 1798 if (ret) 1799 goto out; 1800 } 1801 1802 if (copied) 1803 __mptcp_push_pending(sk, msg->msg_flags); 1804 1805 out: 1806 release_sock(sk); 1807 return copied ? : ret; 1808 } 1809 1810 static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, 1811 struct msghdr *msg, 1812 size_t len, int flags, 1813 struct scm_timestamping_internal *tss, 1814 int *cmsg_flags) 1815 { 1816 struct sk_buff *skb, *tmp; 1817 int copied = 0; 1818 1819 skb_queue_walk_safe(&msk->receive_queue, skb, tmp) { 1820 u32 offset = MPTCP_SKB_CB(skb)->offset; 1821 u32 data_len = skb->len - offset; 1822 u32 count = min_t(size_t, len - copied, data_len); 1823 int err; 1824 1825 if (!(flags & MSG_TRUNC)) { 1826 err = skb_copy_datagram_msg(skb, offset, msg, count); 1827 if (unlikely(err < 0)) { 1828 if (!copied) 1829 return err; 1830 break; 1831 } 1832 } 1833 1834 if (MPTCP_SKB_CB(skb)->has_rxtstamp) { 1835 tcp_update_recv_tstamps(skb, tss); 1836 *cmsg_flags |= MPTCP_CMSG_TS; 1837 } 1838 1839 copied += count; 1840 1841 if (count < data_len) { 1842 if (!(flags & MSG_PEEK)) { 1843 MPTCP_SKB_CB(skb)->offset += count; 1844 MPTCP_SKB_CB(skb)->map_seq += count; 1845 } 1846 break; 1847 } 1848 1849 if (!(flags & MSG_PEEK)) { 1850 /* we will bulk release the skb memory later */ 1851 skb->destructor = NULL; 1852 WRITE_ONCE(msk->rmem_released, msk->rmem_released + skb->truesize); 1853 __skb_unlink(skb, &msk->receive_queue); 1854 __kfree_skb(skb); 1855 } 1856 1857 if (copied >= len) 1858 break; 1859 } 1860 1861 return copied; 1862 } 1863 1864 /* receive buffer autotuning. See tcp_rcv_space_adjust for more information. 1865 * 1866 * Only difference: Use highest rtt estimate of the subflows in use. 1867 */ 1868 static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) 1869 { 1870 struct mptcp_subflow_context *subflow; 1871 struct sock *sk = (struct sock *)msk; 1872 u32 time, advmss = 1; 1873 u64 rtt_us, mstamp; 1874 1875 sock_owned_by_me(sk); 1876 1877 if (copied <= 0) 1878 return; 1879 1880 msk->rcvq_space.copied += copied; 1881 1882 mstamp = div_u64(tcp_clock_ns(), NSEC_PER_USEC); 1883 time = tcp_stamp_us_delta(mstamp, msk->rcvq_space.time); 1884 1885 rtt_us = msk->rcvq_space.rtt_us; 1886 if (rtt_us && time < (rtt_us >> 3)) 1887 return; 1888 1889 rtt_us = 0; 1890 mptcp_for_each_subflow(msk, subflow) { 1891 const struct tcp_sock *tp; 1892 u64 sf_rtt_us; 1893 u32 sf_advmss; 1894 1895 tp = tcp_sk(mptcp_subflow_tcp_sock(subflow)); 1896 1897 sf_rtt_us = READ_ONCE(tp->rcv_rtt_est.rtt_us); 1898 sf_advmss = READ_ONCE(tp->advmss); 1899 1900 rtt_us = max(sf_rtt_us, rtt_us); 1901 advmss = max(sf_advmss, advmss); 1902 } 1903 1904 msk->rcvq_space.rtt_us = rtt_us; 1905 if (time < (rtt_us >> 3) || rtt_us == 0) 1906 return; 1907 1908 if (msk->rcvq_space.copied <= msk->rcvq_space.space) 1909 goto new_measure; 1910 1911 if (sock_net(sk)->ipv4.sysctl_tcp_moderate_rcvbuf && 1912 !(sk->sk_userlocks & SOCK_RCVBUF_LOCK)) { 1913 int rcvmem, rcvbuf; 1914 u64 rcvwin, grow; 1915 1916 rcvwin = ((u64)msk->rcvq_space.copied << 1) + 16 * advmss; 1917 1918 grow = rcvwin * (msk->rcvq_space.copied - msk->rcvq_space.space); 1919 1920 do_div(grow, msk->rcvq_space.space); 1921 rcvwin += (grow << 1); 1922 1923 rcvmem = SKB_TRUESIZE(advmss + MAX_TCP_HEADER); 1924 while (tcp_win_from_space(sk, rcvmem) < advmss) 1925 rcvmem += 128; 1926 1927 do_div(rcvwin, advmss); 1928 rcvbuf = min_t(u64, rcvwin * rcvmem, 1929 sock_net(sk)->ipv4.sysctl_tcp_rmem[2]); 1930 1931 if (rcvbuf > sk->sk_rcvbuf) { 1932 u32 window_clamp; 1933 1934 window_clamp = tcp_win_from_space(sk, rcvbuf); 1935 WRITE_ONCE(sk->sk_rcvbuf, rcvbuf); 1936 1937 /* Make subflows follow along. If we do not do this, we 1938 * get drops at subflow level if skbs can't be moved to 1939 * the mptcp rx queue fast enough (announced rcv_win can 1940 * exceed ssk->sk_rcvbuf). 1941 */ 1942 mptcp_for_each_subflow(msk, subflow) { 1943 struct sock *ssk; 1944 bool slow; 1945 1946 ssk = mptcp_subflow_tcp_sock(subflow); 1947 slow = lock_sock_fast(ssk); 1948 WRITE_ONCE(ssk->sk_rcvbuf, rcvbuf); 1949 tcp_sk(ssk)->window_clamp = window_clamp; 1950 tcp_cleanup_rbuf(ssk, 1); 1951 unlock_sock_fast(ssk, slow); 1952 } 1953 } 1954 } 1955 1956 msk->rcvq_space.space = msk->rcvq_space.copied; 1957 new_measure: 1958 msk->rcvq_space.copied = 0; 1959 msk->rcvq_space.time = mstamp; 1960 } 1961 1962 static void __mptcp_update_rmem(struct sock *sk) 1963 { 1964 struct mptcp_sock *msk = mptcp_sk(sk); 1965 1966 if (!msk->rmem_released) 1967 return; 1968 1969 atomic_sub(msk->rmem_released, &sk->sk_rmem_alloc); 1970 mptcp_rmem_uncharge(sk, msk->rmem_released); 1971 WRITE_ONCE(msk->rmem_released, 0); 1972 } 1973 1974 static void __mptcp_splice_receive_queue(struct sock *sk) 1975 { 1976 struct mptcp_sock *msk = mptcp_sk(sk); 1977 1978 skb_queue_splice_tail_init(&sk->sk_receive_queue, &msk->receive_queue); 1979 } 1980 1981 static bool __mptcp_move_skbs(struct mptcp_sock *msk) 1982 { 1983 struct sock *sk = (struct sock *)msk; 1984 unsigned int moved = 0; 1985 bool ret, done; 1986 1987 do { 1988 struct sock *ssk = mptcp_subflow_recv_lookup(msk); 1989 bool slowpath; 1990 1991 /* we can have data pending in the subflows only if the msk 1992 * receive buffer was full at subflow_data_ready() time, 1993 * that is an unlikely slow path. 1994 */ 1995 if (likely(!ssk)) 1996 break; 1997 1998 slowpath = lock_sock_fast(ssk); 1999 mptcp_data_lock(sk); 2000 __mptcp_update_rmem(sk); 2001 done = __mptcp_move_skbs_from_subflow(msk, ssk, &moved); 2002 mptcp_data_unlock(sk); 2003 2004 if (unlikely(ssk->sk_err)) 2005 __mptcp_error_report(sk); 2006 unlock_sock_fast(ssk, slowpath); 2007 } while (!done); 2008 2009 /* acquire the data lock only if some input data is pending */ 2010 ret = moved > 0; 2011 if (!RB_EMPTY_ROOT(&msk->out_of_order_queue) || 2012 !skb_queue_empty_lockless(&sk->sk_receive_queue)) { 2013 mptcp_data_lock(sk); 2014 __mptcp_update_rmem(sk); 2015 ret |= __mptcp_ofo_queue(msk); 2016 __mptcp_splice_receive_queue(sk); 2017 mptcp_data_unlock(sk); 2018 } 2019 if (ret) 2020 mptcp_check_data_fin((struct sock *)msk); 2021 return !skb_queue_empty(&msk->receive_queue); 2022 } 2023 2024 static unsigned int mptcp_inq_hint(const struct sock *sk) 2025 { 2026 const struct mptcp_sock *msk = mptcp_sk(sk); 2027 const struct sk_buff *skb; 2028 2029 skb = skb_peek(&msk->receive_queue); 2030 if (skb) { 2031 u64 hint_val = msk->ack_seq - MPTCP_SKB_CB(skb)->map_seq; 2032 2033 if (hint_val >= INT_MAX) 2034 return INT_MAX; 2035 2036 return (unsigned int)hint_val; 2037 } 2038 2039 if (sk->sk_state == TCP_CLOSE || (sk->sk_shutdown & RCV_SHUTDOWN)) 2040 return 1; 2041 2042 return 0; 2043 } 2044 2045 static int mptcp_recvmsg(struct sock *sk, struct msghdr *msg, size_t len, 2046 int flags, int *addr_len) 2047 { 2048 struct mptcp_sock *msk = mptcp_sk(sk); 2049 struct scm_timestamping_internal tss; 2050 int copied = 0, cmsg_flags = 0; 2051 int target; 2052 long timeo; 2053 2054 /* MSG_ERRQUEUE is really a no-op till we support IP_RECVERR */ 2055 if (unlikely(flags & MSG_ERRQUEUE)) 2056 return inet_recv_error(sk, msg, len, addr_len); 2057 2058 lock_sock(sk); 2059 if (unlikely(sk->sk_state == TCP_LISTEN)) { 2060 copied = -ENOTCONN; 2061 goto out_err; 2062 } 2063 2064 timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT); 2065 2066 len = min_t(size_t, len, INT_MAX); 2067 target = sock_rcvlowat(sk, flags & MSG_WAITALL, len); 2068 2069 if (unlikely(msk->recvmsg_inq)) 2070 cmsg_flags = MPTCP_CMSG_INQ; 2071 2072 while (copied < len) { 2073 int bytes_read; 2074 2075 bytes_read = __mptcp_recvmsg_mskq(msk, msg, len - copied, flags, &tss, &cmsg_flags); 2076 if (unlikely(bytes_read < 0)) { 2077 if (!copied) 2078 copied = bytes_read; 2079 goto out_err; 2080 } 2081 2082 copied += bytes_read; 2083 2084 /* be sure to advertise window change */ 2085 mptcp_cleanup_rbuf(msk); 2086 2087 if (skb_queue_empty(&msk->receive_queue) && __mptcp_move_skbs(msk)) 2088 continue; 2089 2090 /* only the master socket status is relevant here. The exit 2091 * conditions mirror closely tcp_recvmsg() 2092 */ 2093 if (copied >= target) 2094 break; 2095 2096 if (copied) { 2097 if (sk->sk_err || 2098 sk->sk_state == TCP_CLOSE || 2099 (sk->sk_shutdown & RCV_SHUTDOWN) || 2100 !timeo || 2101 signal_pending(current)) 2102 break; 2103 } else { 2104 if (sk->sk_err) { 2105 copied = sock_error(sk); 2106 break; 2107 } 2108 2109 if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) 2110 mptcp_check_for_eof(msk); 2111 2112 if (sk->sk_shutdown & RCV_SHUTDOWN) { 2113 /* race breaker: the shutdown could be after the 2114 * previous receive queue check 2115 */ 2116 if (__mptcp_move_skbs(msk)) 2117 continue; 2118 break; 2119 } 2120 2121 if (sk->sk_state == TCP_CLOSE) { 2122 copied = -ENOTCONN; 2123 break; 2124 } 2125 2126 if (!timeo) { 2127 copied = -EAGAIN; 2128 break; 2129 } 2130 2131 if (signal_pending(current)) { 2132 copied = sock_intr_errno(timeo); 2133 break; 2134 } 2135 } 2136 2137 pr_debug("block timeout %ld", timeo); 2138 sk_wait_data(sk, &timeo, NULL); 2139 } 2140 2141 out_err: 2142 if (cmsg_flags && copied >= 0) { 2143 if (cmsg_flags & MPTCP_CMSG_TS) 2144 tcp_recv_timestamp(msg, sk, &tss); 2145 2146 if (cmsg_flags & MPTCP_CMSG_INQ) { 2147 unsigned int inq = mptcp_inq_hint(sk); 2148 2149 put_cmsg(msg, SOL_TCP, TCP_CM_INQ, sizeof(inq), &inq); 2150 } 2151 } 2152 2153 pr_debug("msk=%p rx queue empty=%d:%d copied=%d", 2154 msk, skb_queue_empty_lockless(&sk->sk_receive_queue), 2155 skb_queue_empty(&msk->receive_queue), copied); 2156 if (!(flags & MSG_PEEK)) 2157 mptcp_rcv_space_adjust(msk, copied); 2158 2159 release_sock(sk); 2160 return copied; 2161 } 2162 2163 static void mptcp_retransmit_timer(struct timer_list *t) 2164 { 2165 struct inet_connection_sock *icsk = from_timer(icsk, t, 2166 icsk_retransmit_timer); 2167 struct sock *sk = &icsk->icsk_inet.sk; 2168 struct mptcp_sock *msk = mptcp_sk(sk); 2169 2170 bh_lock_sock(sk); 2171 if (!sock_owned_by_user(sk)) { 2172 /* we need a process context to retransmit */ 2173 if (!test_and_set_bit(MPTCP_WORK_RTX, &msk->flags)) 2174 mptcp_schedule_work(sk); 2175 } else { 2176 /* delegate our work to tcp_release_cb() */ 2177 __set_bit(MPTCP_RETRANSMIT, &msk->cb_flags); 2178 } 2179 bh_unlock_sock(sk); 2180 sock_put(sk); 2181 } 2182 2183 static void mptcp_timeout_timer(struct timer_list *t) 2184 { 2185 struct sock *sk = from_timer(sk, t, sk_timer); 2186 2187 mptcp_schedule_work(sk); 2188 sock_put(sk); 2189 } 2190 2191 /* Find an idle subflow. Return NULL if there is unacked data at tcp 2192 * level. 2193 * 2194 * A backup subflow is returned only if that is the only kind available. 2195 */ 2196 static struct sock *mptcp_subflow_get_retrans(struct mptcp_sock *msk) 2197 { 2198 struct sock *backup = NULL, *pick = NULL; 2199 struct mptcp_subflow_context *subflow; 2200 int min_stale_count = INT_MAX; 2201 2202 sock_owned_by_me((const struct sock *)msk); 2203 2204 if (__mptcp_check_fallback(msk)) 2205 return NULL; 2206 2207 mptcp_for_each_subflow(msk, subflow) { 2208 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 2209 2210 if (!__mptcp_subflow_active(subflow)) 2211 continue; 2212 2213 /* still data outstanding at TCP level? skip this */ 2214 if (!tcp_rtx_and_write_queues_empty(ssk)) { 2215 mptcp_pm_subflow_chk_stale(msk, ssk); 2216 min_stale_count = min_t(int, min_stale_count, subflow->stale_count); 2217 continue; 2218 } 2219 2220 if (subflow->backup) { 2221 if (!backup) 2222 backup = ssk; 2223 continue; 2224 } 2225 2226 if (!pick) 2227 pick = ssk; 2228 } 2229 2230 if (pick) 2231 return pick; 2232 2233 /* use backup only if there are no progresses anywhere */ 2234 return min_stale_count > 1 ? backup : NULL; 2235 } 2236 2237 static void mptcp_dispose_initial_subflow(struct mptcp_sock *msk) 2238 { 2239 if (msk->subflow) { 2240 iput(SOCK_INODE(msk->subflow)); 2241 msk->subflow = NULL; 2242 } 2243 } 2244 2245 bool __mptcp_retransmit_pending_data(struct sock *sk) 2246 { 2247 struct mptcp_data_frag *cur, *rtx_head; 2248 struct mptcp_sock *msk = mptcp_sk(sk); 2249 2250 if (__mptcp_check_fallback(mptcp_sk(sk))) 2251 return false; 2252 2253 if (tcp_rtx_and_write_queues_empty(sk)) 2254 return false; 2255 2256 /* the closing socket has some data untransmitted and/or unacked: 2257 * some data in the mptcp rtx queue has not really xmitted yet. 2258 * keep it simple and re-inject the whole mptcp level rtx queue 2259 */ 2260 mptcp_data_lock(sk); 2261 __mptcp_clean_una_wakeup(sk); 2262 rtx_head = mptcp_rtx_head(sk); 2263 if (!rtx_head) { 2264 mptcp_data_unlock(sk); 2265 return false; 2266 } 2267 2268 msk->recovery_snd_nxt = msk->snd_nxt; 2269 msk->recovery = true; 2270 mptcp_data_unlock(sk); 2271 2272 msk->first_pending = rtx_head; 2273 msk->snd_burst = 0; 2274 2275 /* be sure to clear the "sent status" on all re-injected fragments */ 2276 list_for_each_entry(cur, &msk->rtx_queue, list) { 2277 if (!cur->already_sent) 2278 break; 2279 cur->already_sent = 0; 2280 } 2281 2282 return true; 2283 } 2284 2285 /* flags for __mptcp_close_ssk() */ 2286 #define MPTCP_CF_PUSH BIT(1) 2287 #define MPTCP_CF_FASTCLOSE BIT(2) 2288 2289 /* subflow sockets can be either outgoing (connect) or incoming 2290 * (accept). 2291 * 2292 * Outgoing subflows use in-kernel sockets. 2293 * Incoming subflows do not have their own 'struct socket' allocated, 2294 * so we need to use tcp_close() after detaching them from the mptcp 2295 * parent socket. 2296 */ 2297 static void __mptcp_close_ssk(struct sock *sk, struct sock *ssk, 2298 struct mptcp_subflow_context *subflow, 2299 unsigned int flags) 2300 { 2301 struct mptcp_sock *msk = mptcp_sk(sk); 2302 bool need_push, dispose_it; 2303 2304 dispose_it = !msk->subflow || ssk != msk->subflow->sk; 2305 if (dispose_it) 2306 list_del(&subflow->node); 2307 2308 lock_sock_nested(ssk, SINGLE_DEPTH_NESTING); 2309 2310 if (flags & MPTCP_CF_FASTCLOSE) 2311 subflow->send_fastclose = 1; 2312 2313 need_push = (flags & MPTCP_CF_PUSH) && __mptcp_retransmit_pending_data(sk); 2314 if (!dispose_it) { 2315 tcp_disconnect(ssk, 0); 2316 msk->subflow->state = SS_UNCONNECTED; 2317 mptcp_subflow_ctx_reset(subflow); 2318 release_sock(ssk); 2319 2320 goto out; 2321 } 2322 2323 /* if we are invoked by the msk cleanup code, the subflow is 2324 * already orphaned 2325 */ 2326 if (ssk->sk_socket) 2327 sock_orphan(ssk); 2328 2329 subflow->disposable = 1; 2330 2331 /* if ssk hit tcp_done(), tcp_cleanup_ulp() cleared the related ops 2332 * the ssk has been already destroyed, we just need to release the 2333 * reference owned by msk; 2334 */ 2335 if (!inet_csk(ssk)->icsk_ulp_ops) { 2336 kfree_rcu(subflow, rcu); 2337 } else { 2338 /* otherwise tcp will dispose of the ssk and subflow ctx */ 2339 if (ssk->sk_state == TCP_LISTEN) { 2340 tcp_set_state(ssk, TCP_CLOSE); 2341 mptcp_subflow_queue_clean(ssk); 2342 inet_csk_listen_stop(ssk); 2343 } 2344 __tcp_close(ssk, 0); 2345 2346 /* close acquired an extra ref */ 2347 __sock_put(ssk); 2348 } 2349 release_sock(ssk); 2350 2351 sock_put(ssk); 2352 2353 if (ssk == msk->first) 2354 msk->first = NULL; 2355 2356 out: 2357 if (ssk == msk->last_snd) 2358 msk->last_snd = NULL; 2359 2360 if (need_push) 2361 __mptcp_push_pending(sk, 0); 2362 } 2363 2364 void mptcp_close_ssk(struct sock *sk, struct sock *ssk, 2365 struct mptcp_subflow_context *subflow) 2366 { 2367 if (sk->sk_state == TCP_ESTABLISHED) 2368 mptcp_event(MPTCP_EVENT_SUB_CLOSED, mptcp_sk(sk), ssk, GFP_KERNEL); 2369 2370 /* subflow aborted before reaching the fully_established status 2371 * attempt the creation of the next subflow 2372 */ 2373 mptcp_pm_subflow_check_next(mptcp_sk(sk), ssk, subflow); 2374 2375 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_PUSH); 2376 } 2377 2378 static unsigned int mptcp_sync_mss(struct sock *sk, u32 pmtu) 2379 { 2380 return 0; 2381 } 2382 2383 static void __mptcp_close_subflow(struct mptcp_sock *msk) 2384 { 2385 struct mptcp_subflow_context *subflow, *tmp; 2386 2387 might_sleep(); 2388 2389 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { 2390 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 2391 2392 if (inet_sk_state_load(ssk) != TCP_CLOSE) 2393 continue; 2394 2395 /* 'subflow_data_ready' will re-sched once rx queue is empty */ 2396 if (!skb_queue_empty_lockless(&ssk->sk_receive_queue)) 2397 continue; 2398 2399 mptcp_close_ssk((struct sock *)msk, ssk, subflow); 2400 } 2401 } 2402 2403 static bool mptcp_check_close_timeout(const struct sock *sk) 2404 { 2405 s32 delta = tcp_jiffies32 - inet_csk(sk)->icsk_mtup.probe_timestamp; 2406 struct mptcp_subflow_context *subflow; 2407 2408 if (delta >= TCP_TIMEWAIT_LEN) 2409 return true; 2410 2411 /* if all subflows are in closed status don't bother with additional 2412 * timeout 2413 */ 2414 mptcp_for_each_subflow(mptcp_sk(sk), subflow) { 2415 if (inet_sk_state_load(mptcp_subflow_tcp_sock(subflow)) != 2416 TCP_CLOSE) 2417 return false; 2418 } 2419 return true; 2420 } 2421 2422 static void mptcp_check_fastclose(struct mptcp_sock *msk) 2423 { 2424 struct mptcp_subflow_context *subflow, *tmp; 2425 struct sock *sk = &msk->sk.icsk_inet.sk; 2426 2427 if (likely(!READ_ONCE(msk->rcv_fastclose))) 2428 return; 2429 2430 mptcp_token_destroy(msk); 2431 2432 list_for_each_entry_safe(subflow, tmp, &msk->conn_list, node) { 2433 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); 2434 bool slow; 2435 2436 slow = lock_sock_fast(tcp_sk); 2437 if (tcp_sk->sk_state != TCP_CLOSE) { 2438 tcp_send_active_reset(tcp_sk, GFP_ATOMIC); 2439 tcp_set_state(tcp_sk, TCP_CLOSE); 2440 } 2441 unlock_sock_fast(tcp_sk, slow); 2442 } 2443 2444 inet_sk_state_store(sk, TCP_CLOSE); 2445 sk->sk_shutdown = SHUTDOWN_MASK; 2446 smp_mb__before_atomic(); /* SHUTDOWN must be visible first */ 2447 set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags); 2448 2449 mptcp_close_wake_up(sk); 2450 } 2451 2452 static void __mptcp_retrans(struct sock *sk) 2453 { 2454 struct mptcp_sock *msk = mptcp_sk(sk); 2455 struct mptcp_sendmsg_info info = {}; 2456 struct mptcp_data_frag *dfrag; 2457 size_t copied = 0; 2458 struct sock *ssk; 2459 int ret; 2460 2461 mptcp_clean_una_wakeup(sk); 2462 2463 /* first check ssk: need to kick "stale" logic */ 2464 ssk = mptcp_subflow_get_retrans(msk); 2465 dfrag = mptcp_rtx_head(sk); 2466 if (!dfrag) { 2467 if (mptcp_data_fin_enabled(msk)) { 2468 struct inet_connection_sock *icsk = inet_csk(sk); 2469 2470 icsk->icsk_retransmits++; 2471 mptcp_set_datafin_timeout(sk); 2472 mptcp_send_ack(msk); 2473 2474 goto reset_timer; 2475 } 2476 2477 if (!mptcp_send_head(sk)) 2478 return; 2479 2480 goto reset_timer; 2481 } 2482 2483 if (!ssk) 2484 goto reset_timer; 2485 2486 lock_sock(ssk); 2487 2488 /* limit retransmission to the bytes already sent on some subflows */ 2489 info.sent = 0; 2490 info.limit = READ_ONCE(msk->csum_enabled) ? dfrag->data_len : dfrag->already_sent; 2491 while (info.sent < info.limit) { 2492 ret = mptcp_sendmsg_frag(sk, ssk, dfrag, &info); 2493 if (ret <= 0) 2494 break; 2495 2496 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_RETRANSSEGS); 2497 copied += ret; 2498 info.sent += ret; 2499 } 2500 if (copied) { 2501 dfrag->already_sent = max(dfrag->already_sent, info.sent); 2502 tcp_push(ssk, 0, info.mss_now, tcp_sk(ssk)->nonagle, 2503 info.size_goal); 2504 WRITE_ONCE(msk->allow_infinite_fallback, false); 2505 } 2506 2507 release_sock(ssk); 2508 2509 reset_timer: 2510 mptcp_check_and_set_pending(sk); 2511 2512 if (!mptcp_timer_pending(sk)) 2513 mptcp_reset_timer(sk); 2514 } 2515 2516 /* schedule the timeout timer for the relevant event: either close timeout 2517 * or mp_fail timeout. The close timeout takes precedence on the mp_fail one 2518 */ 2519 void mptcp_reset_timeout(struct mptcp_sock *msk, unsigned long fail_tout) 2520 { 2521 struct sock *sk = (struct sock *)msk; 2522 unsigned long timeout, close_timeout; 2523 2524 if (!fail_tout && !sock_flag(sk, SOCK_DEAD)) 2525 return; 2526 2527 close_timeout = inet_csk(sk)->icsk_mtup.probe_timestamp - tcp_jiffies32 + jiffies + TCP_TIMEWAIT_LEN; 2528 2529 /* the close timeout takes precedence on the fail one, and here at least one of 2530 * them is active 2531 */ 2532 timeout = sock_flag(sk, SOCK_DEAD) ? close_timeout : fail_tout; 2533 2534 sk_reset_timer(sk, &sk->sk_timer, timeout); 2535 } 2536 2537 static void mptcp_mp_fail_no_response(struct mptcp_sock *msk) 2538 { 2539 struct sock *ssk = msk->first; 2540 bool slow; 2541 2542 if (!ssk) 2543 return; 2544 2545 pr_debug("MP_FAIL doesn't respond, reset the subflow"); 2546 2547 slow = lock_sock_fast(ssk); 2548 mptcp_subflow_reset(ssk); 2549 WRITE_ONCE(mptcp_subflow_ctx(ssk)->fail_tout, 0); 2550 unlock_sock_fast(ssk, slow); 2551 2552 mptcp_reset_timeout(msk, 0); 2553 } 2554 2555 static void mptcp_worker(struct work_struct *work) 2556 { 2557 struct mptcp_sock *msk = container_of(work, struct mptcp_sock, work); 2558 struct sock *sk = &msk->sk.icsk_inet.sk; 2559 unsigned long fail_tout; 2560 int state; 2561 2562 lock_sock(sk); 2563 state = sk->sk_state; 2564 if (unlikely(state == TCP_CLOSE)) 2565 goto unlock; 2566 2567 mptcp_check_data_fin_ack(sk); 2568 2569 mptcp_check_fastclose(msk); 2570 2571 mptcp_pm_nl_work(msk); 2572 2573 if (test_and_clear_bit(MPTCP_WORK_EOF, &msk->flags)) 2574 mptcp_check_for_eof(msk); 2575 2576 __mptcp_check_send_data_fin(sk); 2577 mptcp_check_data_fin(sk); 2578 2579 /* There is no point in keeping around an orphaned sk timedout or 2580 * closed, but we need the msk around to reply to incoming DATA_FIN, 2581 * even if it is orphaned and in FIN_WAIT2 state 2582 */ 2583 if (sock_flag(sk, SOCK_DEAD) && 2584 (mptcp_check_close_timeout(sk) || sk->sk_state == TCP_CLOSE)) { 2585 inet_sk_state_store(sk, TCP_CLOSE); 2586 __mptcp_destroy_sock(sk); 2587 goto unlock; 2588 } 2589 2590 if (test_and_clear_bit(MPTCP_WORK_CLOSE_SUBFLOW, &msk->flags)) 2591 __mptcp_close_subflow(msk); 2592 2593 if (test_and_clear_bit(MPTCP_WORK_RTX, &msk->flags)) 2594 __mptcp_retrans(sk); 2595 2596 fail_tout = msk->first ? READ_ONCE(mptcp_subflow_ctx(msk->first)->fail_tout) : 0; 2597 if (fail_tout && time_after(jiffies, fail_tout)) 2598 mptcp_mp_fail_no_response(msk); 2599 2600 unlock: 2601 release_sock(sk); 2602 sock_put(sk); 2603 } 2604 2605 static int __mptcp_init_sock(struct sock *sk) 2606 { 2607 struct mptcp_sock *msk = mptcp_sk(sk); 2608 2609 INIT_LIST_HEAD(&msk->conn_list); 2610 INIT_LIST_HEAD(&msk->join_list); 2611 INIT_LIST_HEAD(&msk->rtx_queue); 2612 INIT_WORK(&msk->work, mptcp_worker); 2613 __skb_queue_head_init(&msk->receive_queue); 2614 msk->out_of_order_queue = RB_ROOT; 2615 msk->first_pending = NULL; 2616 msk->rmem_fwd_alloc = 0; 2617 WRITE_ONCE(msk->rmem_released, 0); 2618 msk->timer_ival = TCP_RTO_MIN; 2619 2620 msk->first = NULL; 2621 inet_csk(sk)->icsk_sync_mss = mptcp_sync_mss; 2622 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk))); 2623 WRITE_ONCE(msk->allow_infinite_fallback, true); 2624 msk->recovery = false; 2625 2626 mptcp_pm_data_init(msk); 2627 2628 /* re-use the csk retrans timer for MPTCP-level retrans */ 2629 timer_setup(&msk->sk.icsk_retransmit_timer, mptcp_retransmit_timer, 0); 2630 timer_setup(&sk->sk_timer, mptcp_timeout_timer, 0); 2631 2632 return 0; 2633 } 2634 2635 static void mptcp_ca_reset(struct sock *sk) 2636 { 2637 struct inet_connection_sock *icsk = inet_csk(sk); 2638 2639 tcp_assign_congestion_control(sk); 2640 strcpy(mptcp_sk(sk)->ca_name, icsk->icsk_ca_ops->name); 2641 2642 /* no need to keep a reference to the ops, the name will suffice */ 2643 tcp_cleanup_congestion_control(sk); 2644 icsk->icsk_ca_ops = NULL; 2645 } 2646 2647 static int mptcp_init_sock(struct sock *sk) 2648 { 2649 struct net *net = sock_net(sk); 2650 int ret; 2651 2652 ret = __mptcp_init_sock(sk); 2653 if (ret) 2654 return ret; 2655 2656 if (!mptcp_is_enabled(net)) 2657 return -ENOPROTOOPT; 2658 2659 if (unlikely(!net->mib.mptcp_statistics) && !mptcp_mib_alloc(net)) 2660 return -ENOMEM; 2661 2662 ret = __mptcp_socket_create(mptcp_sk(sk)); 2663 if (ret) 2664 return ret; 2665 2666 /* fetch the ca name; do it outside __mptcp_init_sock(), so that clone will 2667 * propagate the correct value 2668 */ 2669 mptcp_ca_reset(sk); 2670 2671 sk_sockets_allocated_inc(sk); 2672 sk->sk_rcvbuf = sock_net(sk)->ipv4.sysctl_tcp_rmem[1]; 2673 sk->sk_sndbuf = sock_net(sk)->ipv4.sysctl_tcp_wmem[1]; 2674 2675 return 0; 2676 } 2677 2678 static void __mptcp_clear_xmit(struct sock *sk) 2679 { 2680 struct mptcp_sock *msk = mptcp_sk(sk); 2681 struct mptcp_data_frag *dtmp, *dfrag; 2682 2683 WRITE_ONCE(msk->first_pending, NULL); 2684 list_for_each_entry_safe(dfrag, dtmp, &msk->rtx_queue, list) 2685 dfrag_clear(sk, dfrag); 2686 } 2687 2688 static void mptcp_cancel_work(struct sock *sk) 2689 { 2690 struct mptcp_sock *msk = mptcp_sk(sk); 2691 2692 if (cancel_work_sync(&msk->work)) 2693 __sock_put(sk); 2694 } 2695 2696 void mptcp_subflow_shutdown(struct sock *sk, struct sock *ssk, int how) 2697 { 2698 lock_sock(ssk); 2699 2700 switch (ssk->sk_state) { 2701 case TCP_LISTEN: 2702 if (!(how & RCV_SHUTDOWN)) 2703 break; 2704 fallthrough; 2705 case TCP_SYN_SENT: 2706 tcp_disconnect(ssk, O_NONBLOCK); 2707 break; 2708 default: 2709 if (__mptcp_check_fallback(mptcp_sk(sk))) { 2710 pr_debug("Fallback"); 2711 ssk->sk_shutdown |= how; 2712 tcp_shutdown(ssk, how); 2713 } else { 2714 pr_debug("Sending DATA_FIN on subflow %p", ssk); 2715 tcp_send_ack(ssk); 2716 if (!mptcp_timer_pending(sk)) 2717 mptcp_reset_timer(sk); 2718 } 2719 break; 2720 } 2721 2722 release_sock(ssk); 2723 } 2724 2725 static const unsigned char new_state[16] = { 2726 /* current state: new state: action: */ 2727 [0 /* (Invalid) */] = TCP_CLOSE, 2728 [TCP_ESTABLISHED] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2729 [TCP_SYN_SENT] = TCP_CLOSE, 2730 [TCP_SYN_RECV] = TCP_FIN_WAIT1 | TCP_ACTION_FIN, 2731 [TCP_FIN_WAIT1] = TCP_FIN_WAIT1, 2732 [TCP_FIN_WAIT2] = TCP_FIN_WAIT2, 2733 [TCP_TIME_WAIT] = TCP_CLOSE, /* should not happen ! */ 2734 [TCP_CLOSE] = TCP_CLOSE, 2735 [TCP_CLOSE_WAIT] = TCP_LAST_ACK | TCP_ACTION_FIN, 2736 [TCP_LAST_ACK] = TCP_LAST_ACK, 2737 [TCP_LISTEN] = TCP_CLOSE, 2738 [TCP_CLOSING] = TCP_CLOSING, 2739 [TCP_NEW_SYN_RECV] = TCP_CLOSE, /* should not happen ! */ 2740 }; 2741 2742 static int mptcp_close_state(struct sock *sk) 2743 { 2744 int next = (int)new_state[sk->sk_state]; 2745 int ns = next & TCP_STATE_MASK; 2746 2747 inet_sk_state_store(sk, ns); 2748 2749 return next & TCP_ACTION_FIN; 2750 } 2751 2752 static void __mptcp_check_send_data_fin(struct sock *sk) 2753 { 2754 struct mptcp_subflow_context *subflow; 2755 struct mptcp_sock *msk = mptcp_sk(sk); 2756 2757 pr_debug("msk=%p snd_data_fin_enable=%d pending=%d snd_nxt=%llu write_seq=%llu", 2758 msk, msk->snd_data_fin_enable, !!mptcp_send_head(sk), 2759 msk->snd_nxt, msk->write_seq); 2760 2761 /* we still need to enqueue subflows or not really shutting down, 2762 * skip this 2763 */ 2764 if (!msk->snd_data_fin_enable || msk->snd_nxt + 1 != msk->write_seq || 2765 mptcp_send_head(sk)) 2766 return; 2767 2768 WRITE_ONCE(msk->snd_nxt, msk->write_seq); 2769 2770 /* fallback socket will not get data_fin/ack, can move to the next 2771 * state now 2772 */ 2773 if (__mptcp_check_fallback(msk)) { 2774 WRITE_ONCE(msk->snd_una, msk->write_seq); 2775 if ((1 << sk->sk_state) & (TCPF_CLOSING | TCPF_LAST_ACK)) { 2776 inet_sk_state_store(sk, TCP_CLOSE); 2777 mptcp_close_wake_up(sk); 2778 } else if (sk->sk_state == TCP_FIN_WAIT1) { 2779 inet_sk_state_store(sk, TCP_FIN_WAIT2); 2780 } 2781 } 2782 2783 mptcp_for_each_subflow(msk, subflow) { 2784 struct sock *tcp_sk = mptcp_subflow_tcp_sock(subflow); 2785 2786 mptcp_subflow_shutdown(sk, tcp_sk, SEND_SHUTDOWN); 2787 } 2788 } 2789 2790 static void __mptcp_wr_shutdown(struct sock *sk) 2791 { 2792 struct mptcp_sock *msk = mptcp_sk(sk); 2793 2794 pr_debug("msk=%p snd_data_fin_enable=%d shutdown=%x state=%d pending=%d", 2795 msk, msk->snd_data_fin_enable, sk->sk_shutdown, sk->sk_state, 2796 !!mptcp_send_head(sk)); 2797 2798 /* will be ignored by fallback sockets */ 2799 WRITE_ONCE(msk->write_seq, msk->write_seq + 1); 2800 WRITE_ONCE(msk->snd_data_fin_enable, 1); 2801 2802 __mptcp_check_send_data_fin(sk); 2803 } 2804 2805 static void __mptcp_destroy_sock(struct sock *sk) 2806 { 2807 struct mptcp_subflow_context *subflow, *tmp; 2808 struct mptcp_sock *msk = mptcp_sk(sk); 2809 LIST_HEAD(conn_list); 2810 2811 pr_debug("msk=%p", msk); 2812 2813 might_sleep(); 2814 2815 /* join list will be eventually flushed (with rst) at sock lock release time*/ 2816 list_splice_init(&msk->conn_list, &conn_list); 2817 2818 mptcp_stop_timer(sk); 2819 sk_stop_timer(sk, &sk->sk_timer); 2820 msk->pm.status = 0; 2821 2822 /* clears msk->subflow, allowing the following loop to close 2823 * even the initial subflow 2824 */ 2825 mptcp_dispose_initial_subflow(msk); 2826 list_for_each_entry_safe(subflow, tmp, &conn_list, node) { 2827 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 2828 __mptcp_close_ssk(sk, ssk, subflow, 0); 2829 } 2830 2831 sk->sk_prot->destroy(sk); 2832 2833 WARN_ON_ONCE(msk->rmem_fwd_alloc); 2834 WARN_ON_ONCE(msk->rmem_released); 2835 sk_stream_kill_queues(sk); 2836 xfrm_sk_free_policy(sk); 2837 2838 sk_refcnt_debug_release(sk); 2839 sock_put(sk); 2840 } 2841 2842 static void mptcp_close(struct sock *sk, long timeout) 2843 { 2844 struct mptcp_subflow_context *subflow; 2845 struct mptcp_sock *msk = mptcp_sk(sk); 2846 bool do_cancel_work = false; 2847 2848 lock_sock(sk); 2849 sk->sk_shutdown = SHUTDOWN_MASK; 2850 2851 if ((1 << sk->sk_state) & (TCPF_LISTEN | TCPF_CLOSE)) { 2852 inet_sk_state_store(sk, TCP_CLOSE); 2853 goto cleanup; 2854 } 2855 2856 if (mptcp_close_state(sk)) 2857 __mptcp_wr_shutdown(sk); 2858 2859 sk_stream_wait_close(sk, timeout); 2860 2861 cleanup: 2862 /* orphan all the subflows */ 2863 inet_csk(sk)->icsk_mtup.probe_timestamp = tcp_jiffies32; 2864 mptcp_for_each_subflow(msk, subflow) { 2865 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 2866 bool slow = lock_sock_fast_nested(ssk); 2867 2868 /* since the close timeout takes precedence on the fail one, 2869 * cancel the latter 2870 */ 2871 if (ssk == msk->first) 2872 subflow->fail_tout = 0; 2873 2874 sock_orphan(ssk); 2875 unlock_sock_fast(ssk, slow); 2876 } 2877 sock_orphan(sk); 2878 2879 sock_hold(sk); 2880 pr_debug("msk=%p state=%d", sk, sk->sk_state); 2881 if (mptcp_sk(sk)->token) 2882 mptcp_event(MPTCP_EVENT_CLOSED, msk, NULL, GFP_KERNEL); 2883 2884 if (sk->sk_state == TCP_CLOSE) { 2885 __mptcp_destroy_sock(sk); 2886 do_cancel_work = true; 2887 } else { 2888 mptcp_reset_timeout(msk, 0); 2889 } 2890 release_sock(sk); 2891 if (do_cancel_work) 2892 mptcp_cancel_work(sk); 2893 2894 sock_put(sk); 2895 } 2896 2897 static void mptcp_copy_inaddrs(struct sock *msk, const struct sock *ssk) 2898 { 2899 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 2900 const struct ipv6_pinfo *ssk6 = inet6_sk(ssk); 2901 struct ipv6_pinfo *msk6 = inet6_sk(msk); 2902 2903 msk->sk_v6_daddr = ssk->sk_v6_daddr; 2904 msk->sk_v6_rcv_saddr = ssk->sk_v6_rcv_saddr; 2905 2906 if (msk6 && ssk6) { 2907 msk6->saddr = ssk6->saddr; 2908 msk6->flow_label = ssk6->flow_label; 2909 } 2910 #endif 2911 2912 inet_sk(msk)->inet_num = inet_sk(ssk)->inet_num; 2913 inet_sk(msk)->inet_dport = inet_sk(ssk)->inet_dport; 2914 inet_sk(msk)->inet_sport = inet_sk(ssk)->inet_sport; 2915 inet_sk(msk)->inet_daddr = inet_sk(ssk)->inet_daddr; 2916 inet_sk(msk)->inet_saddr = inet_sk(ssk)->inet_saddr; 2917 inet_sk(msk)->inet_rcv_saddr = inet_sk(ssk)->inet_rcv_saddr; 2918 } 2919 2920 static int mptcp_disconnect(struct sock *sk, int flags) 2921 { 2922 struct mptcp_subflow_context *subflow; 2923 struct mptcp_sock *msk = mptcp_sk(sk); 2924 2925 inet_sk_state_store(sk, TCP_CLOSE); 2926 2927 mptcp_for_each_subflow(msk, subflow) { 2928 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 2929 2930 __mptcp_close_ssk(sk, ssk, subflow, MPTCP_CF_FASTCLOSE); 2931 } 2932 2933 mptcp_stop_timer(sk); 2934 sk_stop_timer(sk, &sk->sk_timer); 2935 2936 if (mptcp_sk(sk)->token) 2937 mptcp_event(MPTCP_EVENT_CLOSED, mptcp_sk(sk), NULL, GFP_KERNEL); 2938 2939 mptcp_destroy_common(msk); 2940 msk->last_snd = NULL; 2941 WRITE_ONCE(msk->flags, 0); 2942 msk->cb_flags = 0; 2943 msk->push_pending = 0; 2944 msk->recovery = false; 2945 msk->can_ack = false; 2946 msk->fully_established = false; 2947 msk->rcv_data_fin = false; 2948 msk->snd_data_fin_enable = false; 2949 msk->rcv_fastclose = false; 2950 msk->use_64bit_ack = false; 2951 WRITE_ONCE(msk->csum_enabled, mptcp_is_checksum_enabled(sock_net(sk))); 2952 mptcp_pm_data_reset(msk); 2953 mptcp_ca_reset(sk); 2954 2955 sk->sk_shutdown = 0; 2956 sk_error_report(sk); 2957 return 0; 2958 } 2959 2960 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 2961 static struct ipv6_pinfo *mptcp_inet6_sk(const struct sock *sk) 2962 { 2963 unsigned int offset = sizeof(struct mptcp6_sock) - sizeof(struct ipv6_pinfo); 2964 2965 return (struct ipv6_pinfo *)(((u8 *)sk) + offset); 2966 } 2967 #endif 2968 2969 struct sock *mptcp_sk_clone(const struct sock *sk, 2970 const struct mptcp_options_received *mp_opt, 2971 struct request_sock *req) 2972 { 2973 struct mptcp_subflow_request_sock *subflow_req = mptcp_subflow_rsk(req); 2974 struct sock *nsk = sk_clone_lock(sk, GFP_ATOMIC); 2975 struct mptcp_sock *msk; 2976 u64 ack_seq; 2977 2978 if (!nsk) 2979 return NULL; 2980 2981 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 2982 if (nsk->sk_family == AF_INET6) 2983 inet_sk(nsk)->pinet6 = mptcp_inet6_sk(nsk); 2984 #endif 2985 2986 __mptcp_init_sock(nsk); 2987 2988 msk = mptcp_sk(nsk); 2989 msk->local_key = subflow_req->local_key; 2990 msk->token = subflow_req->token; 2991 msk->subflow = NULL; 2992 WRITE_ONCE(msk->fully_established, false); 2993 if (mp_opt->suboptions & OPTION_MPTCP_CSUMREQD) 2994 WRITE_ONCE(msk->csum_enabled, true); 2995 2996 msk->write_seq = subflow_req->idsn + 1; 2997 msk->snd_nxt = msk->write_seq; 2998 msk->snd_una = msk->write_seq; 2999 msk->wnd_end = msk->snd_nxt + req->rsk_rcv_wnd; 3000 msk->setsockopt_seq = mptcp_sk(sk)->setsockopt_seq; 3001 3002 if (mp_opt->suboptions & OPTIONS_MPTCP_MPC) { 3003 msk->can_ack = true; 3004 msk->remote_key = mp_opt->sndr_key; 3005 mptcp_crypto_key_sha(msk->remote_key, NULL, &ack_seq); 3006 ack_seq++; 3007 WRITE_ONCE(msk->ack_seq, ack_seq); 3008 atomic64_set(&msk->rcv_wnd_sent, ack_seq); 3009 } 3010 3011 sock_reset_flag(nsk, SOCK_RCU_FREE); 3012 /* will be fully established after successful MPC subflow creation */ 3013 inet_sk_state_store(nsk, TCP_SYN_RECV); 3014 3015 security_inet_csk_clone(nsk, req); 3016 bh_unlock_sock(nsk); 3017 3018 /* keep a single reference */ 3019 __sock_put(nsk); 3020 return nsk; 3021 } 3022 3023 void mptcp_rcv_space_init(struct mptcp_sock *msk, const struct sock *ssk) 3024 { 3025 const struct tcp_sock *tp = tcp_sk(ssk); 3026 3027 msk->rcvq_space.copied = 0; 3028 msk->rcvq_space.rtt_us = 0; 3029 3030 msk->rcvq_space.time = tp->tcp_mstamp; 3031 3032 /* initial rcv_space offering made to peer */ 3033 msk->rcvq_space.space = min_t(u32, tp->rcv_wnd, 3034 TCP_INIT_CWND * tp->advmss); 3035 if (msk->rcvq_space.space == 0) 3036 msk->rcvq_space.space = TCP_INIT_CWND * TCP_MSS_DEFAULT; 3037 3038 WRITE_ONCE(msk->wnd_end, msk->snd_nxt + tcp_sk(ssk)->snd_wnd); 3039 } 3040 3041 static struct sock *mptcp_accept(struct sock *sk, int flags, int *err, 3042 bool kern) 3043 { 3044 struct mptcp_sock *msk = mptcp_sk(sk); 3045 struct socket *listener; 3046 struct sock *newsk; 3047 3048 listener = __mptcp_nmpc_socket(msk); 3049 if (WARN_ON_ONCE(!listener)) { 3050 *err = -EINVAL; 3051 return NULL; 3052 } 3053 3054 pr_debug("msk=%p, listener=%p", msk, mptcp_subflow_ctx(listener->sk)); 3055 newsk = inet_csk_accept(listener->sk, flags, err, kern); 3056 if (!newsk) 3057 return NULL; 3058 3059 pr_debug("msk=%p, subflow is mptcp=%d", msk, sk_is_mptcp(newsk)); 3060 if (sk_is_mptcp(newsk)) { 3061 struct mptcp_subflow_context *subflow; 3062 struct sock *new_mptcp_sock; 3063 3064 subflow = mptcp_subflow_ctx(newsk); 3065 new_mptcp_sock = subflow->conn; 3066 3067 /* is_mptcp should be false if subflow->conn is missing, see 3068 * subflow_syn_recv_sock() 3069 */ 3070 if (WARN_ON_ONCE(!new_mptcp_sock)) { 3071 tcp_sk(newsk)->is_mptcp = 0; 3072 goto out; 3073 } 3074 3075 /* acquire the 2nd reference for the owning socket */ 3076 sock_hold(new_mptcp_sock); 3077 newsk = new_mptcp_sock; 3078 MPTCP_INC_STATS(sock_net(sk), MPTCP_MIB_MPCAPABLEPASSIVEACK); 3079 } else { 3080 MPTCP_INC_STATS(sock_net(sk), 3081 MPTCP_MIB_MPCAPABLEPASSIVEFALLBACK); 3082 } 3083 3084 out: 3085 newsk->sk_kern_sock = kern; 3086 return newsk; 3087 } 3088 3089 void mptcp_destroy_common(struct mptcp_sock *msk) 3090 { 3091 struct sock *sk = (struct sock *)msk; 3092 3093 __mptcp_clear_xmit(sk); 3094 3095 /* move to sk_receive_queue, sk_stream_kill_queues will purge it */ 3096 mptcp_data_lock(sk); 3097 skb_queue_splice_tail_init(&msk->receive_queue, &sk->sk_receive_queue); 3098 __skb_queue_purge(&sk->sk_receive_queue); 3099 skb_rbtree_purge(&msk->out_of_order_queue); 3100 mptcp_data_unlock(sk); 3101 3102 /* move all the rx fwd alloc into the sk_mem_reclaim_final in 3103 * inet_sock_destruct() will dispose it 3104 */ 3105 sk->sk_forward_alloc += msk->rmem_fwd_alloc; 3106 msk->rmem_fwd_alloc = 0; 3107 mptcp_token_destroy(msk); 3108 mptcp_pm_free_anno_list(msk); 3109 mptcp_free_local_addr_list(msk); 3110 } 3111 3112 static void mptcp_destroy(struct sock *sk) 3113 { 3114 struct mptcp_sock *msk = mptcp_sk(sk); 3115 3116 mptcp_destroy_common(msk); 3117 sk_sockets_allocated_dec(sk); 3118 } 3119 3120 void __mptcp_data_acked(struct sock *sk) 3121 { 3122 if (!sock_owned_by_user(sk)) 3123 __mptcp_clean_una(sk); 3124 else 3125 __set_bit(MPTCP_CLEAN_UNA, &mptcp_sk(sk)->cb_flags); 3126 3127 if (mptcp_pending_data_fin_ack(sk)) 3128 mptcp_schedule_work(sk); 3129 } 3130 3131 void __mptcp_check_push(struct sock *sk, struct sock *ssk) 3132 { 3133 if (!mptcp_send_head(sk)) 3134 return; 3135 3136 if (!sock_owned_by_user(sk)) { 3137 struct sock *xmit_ssk = mptcp_subflow_get_send(mptcp_sk(sk)); 3138 3139 if (xmit_ssk == ssk) 3140 __mptcp_subflow_push_pending(sk, ssk); 3141 else if (xmit_ssk) 3142 mptcp_subflow_delegate(mptcp_subflow_ctx(xmit_ssk), MPTCP_DELEGATE_SEND); 3143 } else { 3144 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags); 3145 } 3146 } 3147 3148 #define MPTCP_FLAGS_PROCESS_CTX_NEED (BIT(MPTCP_PUSH_PENDING) | \ 3149 BIT(MPTCP_RETRANSMIT) | \ 3150 BIT(MPTCP_FLUSH_JOIN_LIST)) 3151 3152 /* processes deferred events and flush wmem */ 3153 static void mptcp_release_cb(struct sock *sk) 3154 __must_hold(&sk->sk_lock.slock) 3155 { 3156 struct mptcp_sock *msk = mptcp_sk(sk); 3157 3158 for (;;) { 3159 unsigned long flags = (msk->cb_flags & MPTCP_FLAGS_PROCESS_CTX_NEED) | 3160 msk->push_pending; 3161 if (!flags) 3162 break; 3163 3164 /* the following actions acquire the subflow socket lock 3165 * 3166 * 1) can't be invoked in atomic scope 3167 * 2) must avoid ABBA deadlock with msk socket spinlock: the RX 3168 * datapath acquires the msk socket spinlock while helding 3169 * the subflow socket lock 3170 */ 3171 msk->push_pending = 0; 3172 msk->cb_flags &= ~flags; 3173 spin_unlock_bh(&sk->sk_lock.slock); 3174 if (flags & BIT(MPTCP_FLUSH_JOIN_LIST)) 3175 __mptcp_flush_join_list(sk); 3176 if (flags & BIT(MPTCP_PUSH_PENDING)) 3177 __mptcp_push_pending(sk, 0); 3178 if (flags & BIT(MPTCP_RETRANSMIT)) 3179 __mptcp_retrans(sk); 3180 3181 cond_resched(); 3182 spin_lock_bh(&sk->sk_lock.slock); 3183 } 3184 3185 if (__test_and_clear_bit(MPTCP_CLEAN_UNA, &msk->cb_flags)) 3186 __mptcp_clean_una_wakeup(sk); 3187 if (unlikely(&msk->cb_flags)) { 3188 /* be sure to set the current sk state before tacking actions 3189 * depending on sk_state, that is processing MPTCP_ERROR_REPORT 3190 */ 3191 if (__test_and_clear_bit(MPTCP_CONNECTED, &msk->cb_flags)) 3192 __mptcp_set_connected(sk); 3193 if (__test_and_clear_bit(MPTCP_ERROR_REPORT, &msk->cb_flags)) 3194 __mptcp_error_report(sk); 3195 if (__test_and_clear_bit(MPTCP_RESET_SCHEDULER, &msk->cb_flags)) 3196 msk->last_snd = NULL; 3197 } 3198 3199 __mptcp_update_rmem(sk); 3200 } 3201 3202 /* MP_JOIN client subflow must wait for 4th ack before sending any data: 3203 * TCP can't schedule delack timer before the subflow is fully established. 3204 * MPTCP uses the delack timer to do 3rd ack retransmissions 3205 */ 3206 static void schedule_3rdack_retransmission(struct sock *ssk) 3207 { 3208 struct inet_connection_sock *icsk = inet_csk(ssk); 3209 struct tcp_sock *tp = tcp_sk(ssk); 3210 unsigned long timeout; 3211 3212 if (mptcp_subflow_ctx(ssk)->fully_established) 3213 return; 3214 3215 /* reschedule with a timeout above RTT, as we must look only for drop */ 3216 if (tp->srtt_us) 3217 timeout = usecs_to_jiffies(tp->srtt_us >> (3 - 1)); 3218 else 3219 timeout = TCP_TIMEOUT_INIT; 3220 timeout += jiffies; 3221 3222 WARN_ON_ONCE(icsk->icsk_ack.pending & ICSK_ACK_TIMER); 3223 icsk->icsk_ack.pending |= ICSK_ACK_SCHED | ICSK_ACK_TIMER; 3224 icsk->icsk_ack.timeout = timeout; 3225 sk_reset_timer(ssk, &icsk->icsk_delack_timer, timeout); 3226 } 3227 3228 void mptcp_subflow_process_delegated(struct sock *ssk) 3229 { 3230 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 3231 struct sock *sk = subflow->conn; 3232 3233 if (test_bit(MPTCP_DELEGATE_SEND, &subflow->delegated_status)) { 3234 mptcp_data_lock(sk); 3235 if (!sock_owned_by_user(sk)) 3236 __mptcp_subflow_push_pending(sk, ssk); 3237 else 3238 __set_bit(MPTCP_PUSH_PENDING, &mptcp_sk(sk)->cb_flags); 3239 mptcp_data_unlock(sk); 3240 mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_SEND); 3241 } 3242 if (test_bit(MPTCP_DELEGATE_ACK, &subflow->delegated_status)) { 3243 schedule_3rdack_retransmission(ssk); 3244 mptcp_subflow_delegated_done(subflow, MPTCP_DELEGATE_ACK); 3245 } 3246 } 3247 3248 static int mptcp_hash(struct sock *sk) 3249 { 3250 /* should never be called, 3251 * we hash the TCP subflows not the master socket 3252 */ 3253 WARN_ON_ONCE(1); 3254 return 0; 3255 } 3256 3257 static void mptcp_unhash(struct sock *sk) 3258 { 3259 /* called from sk_common_release(), but nothing to do here */ 3260 } 3261 3262 static int mptcp_get_port(struct sock *sk, unsigned short snum) 3263 { 3264 struct mptcp_sock *msk = mptcp_sk(sk); 3265 struct socket *ssock; 3266 3267 ssock = __mptcp_nmpc_socket(msk); 3268 pr_debug("msk=%p, subflow=%p", msk, ssock); 3269 if (WARN_ON_ONCE(!ssock)) 3270 return -EINVAL; 3271 3272 return inet_csk_get_port(ssock->sk, snum); 3273 } 3274 3275 void mptcp_finish_connect(struct sock *ssk) 3276 { 3277 struct mptcp_subflow_context *subflow; 3278 struct mptcp_sock *msk; 3279 struct sock *sk; 3280 u64 ack_seq; 3281 3282 subflow = mptcp_subflow_ctx(ssk); 3283 sk = subflow->conn; 3284 msk = mptcp_sk(sk); 3285 3286 pr_debug("msk=%p, token=%u", sk, subflow->token); 3287 3288 mptcp_crypto_key_sha(subflow->remote_key, NULL, &ack_seq); 3289 ack_seq++; 3290 subflow->map_seq = ack_seq; 3291 subflow->map_subflow_seq = 1; 3292 3293 /* the socket is not connected yet, no msk/subflow ops can access/race 3294 * accessing the field below 3295 */ 3296 WRITE_ONCE(msk->remote_key, subflow->remote_key); 3297 WRITE_ONCE(msk->local_key, subflow->local_key); 3298 WRITE_ONCE(msk->write_seq, subflow->idsn + 1); 3299 WRITE_ONCE(msk->snd_nxt, msk->write_seq); 3300 WRITE_ONCE(msk->ack_seq, ack_seq); 3301 WRITE_ONCE(msk->can_ack, 1); 3302 WRITE_ONCE(msk->snd_una, msk->write_seq); 3303 atomic64_set(&msk->rcv_wnd_sent, ack_seq); 3304 3305 mptcp_pm_new_connection(msk, ssk, 0); 3306 3307 mptcp_rcv_space_init(msk, ssk); 3308 } 3309 3310 void mptcp_sock_graft(struct sock *sk, struct socket *parent) 3311 { 3312 write_lock_bh(&sk->sk_callback_lock); 3313 rcu_assign_pointer(sk->sk_wq, &parent->wq); 3314 sk_set_socket(sk, parent); 3315 sk->sk_uid = SOCK_INODE(parent)->i_uid; 3316 write_unlock_bh(&sk->sk_callback_lock); 3317 } 3318 3319 bool mptcp_finish_join(struct sock *ssk) 3320 { 3321 struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); 3322 struct mptcp_sock *msk = mptcp_sk(subflow->conn); 3323 struct sock *parent = (void *)msk; 3324 bool ret = true; 3325 3326 pr_debug("msk=%p, subflow=%p", msk, subflow); 3327 3328 /* mptcp socket already closing? */ 3329 if (!mptcp_is_fully_established(parent)) { 3330 subflow->reset_reason = MPTCP_RST_EMPTCP; 3331 return false; 3332 } 3333 3334 if (!list_empty(&subflow->node)) 3335 goto out; 3336 3337 if (!mptcp_pm_allow_new_subflow(msk)) 3338 goto err_prohibited; 3339 3340 /* active connections are already on conn_list. 3341 * If we can't acquire msk socket lock here, let the release callback 3342 * handle it 3343 */ 3344 mptcp_data_lock(parent); 3345 if (!sock_owned_by_user(parent)) { 3346 ret = __mptcp_finish_join(msk, ssk); 3347 if (ret) { 3348 sock_hold(ssk); 3349 list_add_tail(&subflow->node, &msk->conn_list); 3350 } 3351 } else { 3352 sock_hold(ssk); 3353 list_add_tail(&subflow->node, &msk->join_list); 3354 __set_bit(MPTCP_FLUSH_JOIN_LIST, &msk->cb_flags); 3355 } 3356 mptcp_data_unlock(parent); 3357 3358 if (!ret) { 3359 err_prohibited: 3360 subflow->reset_reason = MPTCP_RST_EPROHIBIT; 3361 return false; 3362 } 3363 3364 subflow->map_seq = READ_ONCE(msk->ack_seq); 3365 WRITE_ONCE(msk->allow_infinite_fallback, false); 3366 3367 out: 3368 mptcp_event(MPTCP_EVENT_SUB_ESTABLISHED, msk, ssk, GFP_ATOMIC); 3369 return true; 3370 } 3371 3372 static void mptcp_shutdown(struct sock *sk, int how) 3373 { 3374 pr_debug("sk=%p, how=%d", sk, how); 3375 3376 if ((how & SEND_SHUTDOWN) && mptcp_close_state(sk)) 3377 __mptcp_wr_shutdown(sk); 3378 } 3379 3380 static int mptcp_forward_alloc_get(const struct sock *sk) 3381 { 3382 return sk->sk_forward_alloc + mptcp_sk(sk)->rmem_fwd_alloc; 3383 } 3384 3385 static int mptcp_ioctl_outq(const struct mptcp_sock *msk, u64 v) 3386 { 3387 const struct sock *sk = (void *)msk; 3388 u64 delta; 3389 3390 if (sk->sk_state == TCP_LISTEN) 3391 return -EINVAL; 3392 3393 if ((1 << sk->sk_state) & (TCPF_SYN_SENT | TCPF_SYN_RECV)) 3394 return 0; 3395 3396 delta = msk->write_seq - v; 3397 if (__mptcp_check_fallback(msk) && msk->first) { 3398 struct tcp_sock *tp = tcp_sk(msk->first); 3399 3400 /* the first subflow is disconnected after close - see 3401 * __mptcp_close_ssk(). tcp_disconnect() moves the write_seq 3402 * so ignore that status, too. 3403 */ 3404 if (!((1 << msk->first->sk_state) & 3405 (TCPF_SYN_SENT | TCPF_SYN_RECV | TCPF_CLOSE))) 3406 delta += READ_ONCE(tp->write_seq) - tp->snd_una; 3407 } 3408 if (delta > INT_MAX) 3409 delta = INT_MAX; 3410 3411 return (int)delta; 3412 } 3413 3414 static int mptcp_ioctl(struct sock *sk, int cmd, unsigned long arg) 3415 { 3416 struct mptcp_sock *msk = mptcp_sk(sk); 3417 bool slow; 3418 int answ; 3419 3420 switch (cmd) { 3421 case SIOCINQ: 3422 if (sk->sk_state == TCP_LISTEN) 3423 return -EINVAL; 3424 3425 lock_sock(sk); 3426 __mptcp_move_skbs(msk); 3427 answ = mptcp_inq_hint(sk); 3428 release_sock(sk); 3429 break; 3430 case SIOCOUTQ: 3431 slow = lock_sock_fast(sk); 3432 answ = mptcp_ioctl_outq(msk, READ_ONCE(msk->snd_una)); 3433 unlock_sock_fast(sk, slow); 3434 break; 3435 case SIOCOUTQNSD: 3436 slow = lock_sock_fast(sk); 3437 answ = mptcp_ioctl_outq(msk, msk->snd_nxt); 3438 unlock_sock_fast(sk, slow); 3439 break; 3440 default: 3441 return -ENOIOCTLCMD; 3442 } 3443 3444 return put_user(answ, (int __user *)arg); 3445 } 3446 3447 static struct proto mptcp_prot = { 3448 .name = "MPTCP", 3449 .owner = THIS_MODULE, 3450 .init = mptcp_init_sock, 3451 .disconnect = mptcp_disconnect, 3452 .close = mptcp_close, 3453 .accept = mptcp_accept, 3454 .setsockopt = mptcp_setsockopt, 3455 .getsockopt = mptcp_getsockopt, 3456 .shutdown = mptcp_shutdown, 3457 .destroy = mptcp_destroy, 3458 .sendmsg = mptcp_sendmsg, 3459 .ioctl = mptcp_ioctl, 3460 .recvmsg = mptcp_recvmsg, 3461 .release_cb = mptcp_release_cb, 3462 .hash = mptcp_hash, 3463 .unhash = mptcp_unhash, 3464 .get_port = mptcp_get_port, 3465 .forward_alloc_get = mptcp_forward_alloc_get, 3466 .sockets_allocated = &mptcp_sockets_allocated, 3467 .memory_allocated = &tcp_memory_allocated, 3468 .memory_pressure = &tcp_memory_pressure, 3469 .sysctl_wmem_offset = offsetof(struct net, ipv4.sysctl_tcp_wmem), 3470 .sysctl_rmem_offset = offsetof(struct net, ipv4.sysctl_tcp_rmem), 3471 .sysctl_mem = sysctl_tcp_mem, 3472 .obj_size = sizeof(struct mptcp_sock), 3473 .slab_flags = SLAB_TYPESAFE_BY_RCU, 3474 .no_autobind = true, 3475 }; 3476 3477 static int mptcp_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len) 3478 { 3479 struct mptcp_sock *msk = mptcp_sk(sock->sk); 3480 struct socket *ssock; 3481 int err; 3482 3483 lock_sock(sock->sk); 3484 ssock = __mptcp_nmpc_socket(msk); 3485 if (!ssock) { 3486 err = -EINVAL; 3487 goto unlock; 3488 } 3489 3490 err = ssock->ops->bind(ssock, uaddr, addr_len); 3491 if (!err) 3492 mptcp_copy_inaddrs(sock->sk, ssock->sk); 3493 3494 unlock: 3495 release_sock(sock->sk); 3496 return err; 3497 } 3498 3499 static void mptcp_subflow_early_fallback(struct mptcp_sock *msk, 3500 struct mptcp_subflow_context *subflow) 3501 { 3502 subflow->request_mptcp = 0; 3503 __mptcp_do_fallback(msk); 3504 } 3505 3506 static int mptcp_stream_connect(struct socket *sock, struct sockaddr *uaddr, 3507 int addr_len, int flags) 3508 { 3509 struct mptcp_sock *msk = mptcp_sk(sock->sk); 3510 struct mptcp_subflow_context *subflow; 3511 struct socket *ssock; 3512 int err = -EINVAL; 3513 3514 lock_sock(sock->sk); 3515 if (uaddr) { 3516 if (addr_len < sizeof(uaddr->sa_family)) 3517 goto unlock; 3518 3519 if (uaddr->sa_family == AF_UNSPEC) { 3520 err = mptcp_disconnect(sock->sk, flags); 3521 sock->state = err ? SS_DISCONNECTING : SS_UNCONNECTED; 3522 goto unlock; 3523 } 3524 } 3525 3526 if (sock->state != SS_UNCONNECTED && msk->subflow) { 3527 /* pending connection or invalid state, let existing subflow 3528 * cope with that 3529 */ 3530 ssock = msk->subflow; 3531 goto do_connect; 3532 } 3533 3534 ssock = __mptcp_nmpc_socket(msk); 3535 if (!ssock) 3536 goto unlock; 3537 3538 mptcp_token_destroy(msk); 3539 inet_sk_state_store(sock->sk, TCP_SYN_SENT); 3540 subflow = mptcp_subflow_ctx(ssock->sk); 3541 #ifdef CONFIG_TCP_MD5SIG 3542 /* no MPTCP if MD5SIG is enabled on this socket or we may run out of 3543 * TCP option space. 3544 */ 3545 if (rcu_access_pointer(tcp_sk(ssock->sk)->md5sig_info)) 3546 mptcp_subflow_early_fallback(msk, subflow); 3547 #endif 3548 if (subflow->request_mptcp && mptcp_token_new_connect(ssock->sk)) { 3549 MPTCP_INC_STATS(sock_net(ssock->sk), MPTCP_MIB_TOKENFALLBACKINIT); 3550 mptcp_subflow_early_fallback(msk, subflow); 3551 } 3552 if (likely(!__mptcp_check_fallback(msk))) 3553 MPTCP_INC_STATS(sock_net(sock->sk), MPTCP_MIB_MPCAPABLEACTIVE); 3554 3555 do_connect: 3556 err = ssock->ops->connect(ssock, uaddr, addr_len, flags); 3557 sock->state = ssock->state; 3558 3559 /* on successful connect, the msk state will be moved to established by 3560 * subflow_finish_connect() 3561 */ 3562 if (!err || err == -EINPROGRESS) 3563 mptcp_copy_inaddrs(sock->sk, ssock->sk); 3564 else 3565 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); 3566 3567 unlock: 3568 release_sock(sock->sk); 3569 return err; 3570 } 3571 3572 static int mptcp_listen(struct socket *sock, int backlog) 3573 { 3574 struct mptcp_sock *msk = mptcp_sk(sock->sk); 3575 struct socket *ssock; 3576 int err; 3577 3578 pr_debug("msk=%p", msk); 3579 3580 lock_sock(sock->sk); 3581 ssock = __mptcp_nmpc_socket(msk); 3582 if (!ssock) { 3583 err = -EINVAL; 3584 goto unlock; 3585 } 3586 3587 mptcp_token_destroy(msk); 3588 inet_sk_state_store(sock->sk, TCP_LISTEN); 3589 sock_set_flag(sock->sk, SOCK_RCU_FREE); 3590 3591 err = ssock->ops->listen(ssock, backlog); 3592 inet_sk_state_store(sock->sk, inet_sk_state_load(ssock->sk)); 3593 if (!err) 3594 mptcp_copy_inaddrs(sock->sk, ssock->sk); 3595 3596 unlock: 3597 release_sock(sock->sk); 3598 return err; 3599 } 3600 3601 static int mptcp_stream_accept(struct socket *sock, struct socket *newsock, 3602 int flags, bool kern) 3603 { 3604 struct mptcp_sock *msk = mptcp_sk(sock->sk); 3605 struct socket *ssock; 3606 int err; 3607 3608 pr_debug("msk=%p", msk); 3609 3610 ssock = __mptcp_nmpc_socket(msk); 3611 if (!ssock) 3612 return -EINVAL; 3613 3614 err = ssock->ops->accept(sock, newsock, flags, kern); 3615 if (err == 0 && !mptcp_is_tcpsk(newsock->sk)) { 3616 struct mptcp_sock *msk = mptcp_sk(newsock->sk); 3617 struct mptcp_subflow_context *subflow; 3618 struct sock *newsk = newsock->sk; 3619 3620 lock_sock(newsk); 3621 3622 /* PM/worker can now acquire the first subflow socket 3623 * lock without racing with listener queue cleanup, 3624 * we can notify it, if needed. 3625 * 3626 * Even if remote has reset the initial subflow by now 3627 * the refcnt is still at least one. 3628 */ 3629 subflow = mptcp_subflow_ctx(msk->first); 3630 list_add(&subflow->node, &msk->conn_list); 3631 sock_hold(msk->first); 3632 if (mptcp_is_fully_established(newsk)) 3633 mptcp_pm_fully_established(msk, msk->first, GFP_KERNEL); 3634 3635 mptcp_copy_inaddrs(newsk, msk->first); 3636 mptcp_rcv_space_init(msk, msk->first); 3637 mptcp_propagate_sndbuf(newsk, msk->first); 3638 3639 /* set ssk->sk_socket of accept()ed flows to mptcp socket. 3640 * This is needed so NOSPACE flag can be set from tcp stack. 3641 */ 3642 mptcp_for_each_subflow(msk, subflow) { 3643 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 3644 3645 if (!ssk->sk_socket) 3646 mptcp_sock_graft(ssk, newsock); 3647 } 3648 release_sock(newsk); 3649 } 3650 3651 return err; 3652 } 3653 3654 static __poll_t mptcp_check_readable(struct mptcp_sock *msk) 3655 { 3656 /* Concurrent splices from sk_receive_queue into receive_queue will 3657 * always show at least one non-empty queue when checked in this order. 3658 */ 3659 if (skb_queue_empty_lockless(&((struct sock *)msk)->sk_receive_queue) && 3660 skb_queue_empty_lockless(&msk->receive_queue)) 3661 return 0; 3662 3663 return EPOLLIN | EPOLLRDNORM; 3664 } 3665 3666 static __poll_t mptcp_check_writeable(struct mptcp_sock *msk) 3667 { 3668 struct sock *sk = (struct sock *)msk; 3669 3670 if (unlikely(sk->sk_shutdown & SEND_SHUTDOWN)) 3671 return EPOLLOUT | EPOLLWRNORM; 3672 3673 if (sk_stream_is_writeable(sk)) 3674 return EPOLLOUT | EPOLLWRNORM; 3675 3676 mptcp_set_nospace(sk); 3677 smp_mb__after_atomic(); /* msk->flags is changed by write_space cb */ 3678 if (sk_stream_is_writeable(sk)) 3679 return EPOLLOUT | EPOLLWRNORM; 3680 3681 return 0; 3682 } 3683 3684 static __poll_t mptcp_poll(struct file *file, struct socket *sock, 3685 struct poll_table_struct *wait) 3686 { 3687 struct sock *sk = sock->sk; 3688 struct mptcp_sock *msk; 3689 __poll_t mask = 0; 3690 int state; 3691 3692 msk = mptcp_sk(sk); 3693 sock_poll_wait(file, sock, wait); 3694 3695 state = inet_sk_state_load(sk); 3696 pr_debug("msk=%p state=%d flags=%lx", msk, state, msk->flags); 3697 if (state == TCP_LISTEN) { 3698 if (WARN_ON_ONCE(!msk->subflow || !msk->subflow->sk)) 3699 return 0; 3700 3701 return inet_csk_listen_poll(msk->subflow->sk); 3702 } 3703 3704 if (state != TCP_SYN_SENT && state != TCP_SYN_RECV) { 3705 mask |= mptcp_check_readable(msk); 3706 mask |= mptcp_check_writeable(msk); 3707 } 3708 if (sk->sk_shutdown == SHUTDOWN_MASK || state == TCP_CLOSE) 3709 mask |= EPOLLHUP; 3710 if (sk->sk_shutdown & RCV_SHUTDOWN) 3711 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP; 3712 3713 /* This barrier is coupled with smp_wmb() in tcp_reset() */ 3714 smp_rmb(); 3715 if (sk->sk_err) 3716 mask |= EPOLLERR; 3717 3718 return mask; 3719 } 3720 3721 static const struct proto_ops mptcp_stream_ops = { 3722 .family = PF_INET, 3723 .owner = THIS_MODULE, 3724 .release = inet_release, 3725 .bind = mptcp_bind, 3726 .connect = mptcp_stream_connect, 3727 .socketpair = sock_no_socketpair, 3728 .accept = mptcp_stream_accept, 3729 .getname = inet_getname, 3730 .poll = mptcp_poll, 3731 .ioctl = inet_ioctl, 3732 .gettstamp = sock_gettstamp, 3733 .listen = mptcp_listen, 3734 .shutdown = inet_shutdown, 3735 .setsockopt = sock_common_setsockopt, 3736 .getsockopt = sock_common_getsockopt, 3737 .sendmsg = inet_sendmsg, 3738 .recvmsg = inet_recvmsg, 3739 .mmap = sock_no_mmap, 3740 .sendpage = inet_sendpage, 3741 }; 3742 3743 static struct inet_protosw mptcp_protosw = { 3744 .type = SOCK_STREAM, 3745 .protocol = IPPROTO_MPTCP, 3746 .prot = &mptcp_prot, 3747 .ops = &mptcp_stream_ops, 3748 .flags = INET_PROTOSW_ICSK, 3749 }; 3750 3751 static int mptcp_napi_poll(struct napi_struct *napi, int budget) 3752 { 3753 struct mptcp_delegated_action *delegated; 3754 struct mptcp_subflow_context *subflow; 3755 int work_done = 0; 3756 3757 delegated = container_of(napi, struct mptcp_delegated_action, napi); 3758 while ((subflow = mptcp_subflow_delegated_next(delegated)) != NULL) { 3759 struct sock *ssk = mptcp_subflow_tcp_sock(subflow); 3760 3761 bh_lock_sock_nested(ssk); 3762 if (!sock_owned_by_user(ssk) && 3763 mptcp_subflow_has_delegated_action(subflow)) 3764 mptcp_subflow_process_delegated(ssk); 3765 /* ... elsewhere tcp_release_cb_override already processed 3766 * the action or will do at next release_sock(). 3767 * In both case must dequeue the subflow here - on the same 3768 * CPU that scheduled it. 3769 */ 3770 bh_unlock_sock(ssk); 3771 sock_put(ssk); 3772 3773 if (++work_done == budget) 3774 return budget; 3775 } 3776 3777 /* always provide a 0 'work_done' argument, so that napi_complete_done 3778 * will not try accessing the NULL napi->dev ptr 3779 */ 3780 napi_complete_done(napi, 0); 3781 return work_done; 3782 } 3783 3784 void __init mptcp_proto_init(void) 3785 { 3786 struct mptcp_delegated_action *delegated; 3787 int cpu; 3788 3789 mptcp_prot.h.hashinfo = tcp_prot.h.hashinfo; 3790 3791 if (percpu_counter_init(&mptcp_sockets_allocated, 0, GFP_KERNEL)) 3792 panic("Failed to allocate MPTCP pcpu counter\n"); 3793 3794 init_dummy_netdev(&mptcp_napi_dev); 3795 for_each_possible_cpu(cpu) { 3796 delegated = per_cpu_ptr(&mptcp_delegated_actions, cpu); 3797 INIT_LIST_HEAD(&delegated->head); 3798 netif_napi_add_tx(&mptcp_napi_dev, &delegated->napi, 3799 mptcp_napi_poll); 3800 napi_enable(&delegated->napi); 3801 } 3802 3803 mptcp_subflow_init(); 3804 mptcp_pm_init(); 3805 mptcp_token_init(); 3806 3807 if (proto_register(&mptcp_prot, 1) != 0) 3808 panic("Failed to register MPTCP proto.\n"); 3809 3810 inet_register_protosw(&mptcp_protosw); 3811 3812 BUILD_BUG_ON(sizeof(struct mptcp_skb_cb) > sizeof_field(struct sk_buff, cb)); 3813 } 3814 3815 #if IS_ENABLED(CONFIG_MPTCP_IPV6) 3816 static const struct proto_ops mptcp_v6_stream_ops = { 3817 .family = PF_INET6, 3818 .owner = THIS_MODULE, 3819 .release = inet6_release, 3820 .bind = mptcp_bind, 3821 .connect = mptcp_stream_connect, 3822 .socketpair = sock_no_socketpair, 3823 .accept = mptcp_stream_accept, 3824 .getname = inet6_getname, 3825 .poll = mptcp_poll, 3826 .ioctl = inet6_ioctl, 3827 .gettstamp = sock_gettstamp, 3828 .listen = mptcp_listen, 3829 .shutdown = inet_shutdown, 3830 .setsockopt = sock_common_setsockopt, 3831 .getsockopt = sock_common_getsockopt, 3832 .sendmsg = inet6_sendmsg, 3833 .recvmsg = inet6_recvmsg, 3834 .mmap = sock_no_mmap, 3835 .sendpage = inet_sendpage, 3836 #ifdef CONFIG_COMPAT 3837 .compat_ioctl = inet6_compat_ioctl, 3838 #endif 3839 }; 3840 3841 static struct proto mptcp_v6_prot; 3842 3843 static void mptcp_v6_destroy(struct sock *sk) 3844 { 3845 mptcp_destroy(sk); 3846 inet6_destroy_sock(sk); 3847 } 3848 3849 static struct inet_protosw mptcp_v6_protosw = { 3850 .type = SOCK_STREAM, 3851 .protocol = IPPROTO_MPTCP, 3852 .prot = &mptcp_v6_prot, 3853 .ops = &mptcp_v6_stream_ops, 3854 .flags = INET_PROTOSW_ICSK, 3855 }; 3856 3857 int __init mptcp_proto_v6_init(void) 3858 { 3859 int err; 3860 3861 mptcp_v6_prot = mptcp_prot; 3862 strcpy(mptcp_v6_prot.name, "MPTCPv6"); 3863 mptcp_v6_prot.slab = NULL; 3864 mptcp_v6_prot.destroy = mptcp_v6_destroy; 3865 mptcp_v6_prot.obj_size = sizeof(struct mptcp6_sock); 3866 3867 err = proto_register(&mptcp_v6_prot, 1); 3868 if (err) 3869 return err; 3870 3871 err = inet6_register_protosw(&mptcp_v6_protosw); 3872 if (err) 3873 proto_unregister(&mptcp_v6_prot); 3874 3875 return err; 3876 } 3877 #endif 3878