1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * INET An implementation of the TCP/IP protocol suite for the LINUX 4 * operating system. INET is implemented using the BSD Socket 5 * interface as the means of communication with the user level. 6 * 7 * Support for INET connection oriented protocols. 8 * 9 * Authors: See the TCP sources 10 */ 11 12 #include <linux/module.h> 13 #include <linux/jhash.h> 14 15 #include <net/inet_connection_sock.h> 16 #include <net/inet_hashtables.h> 17 #include <net/inet_timewait_sock.h> 18 #include <net/ip.h> 19 #include <net/route.h> 20 #include <net/tcp_states.h> 21 #include <net/xfrm.h> 22 #include <net/tcp.h> 23 #include <net/sock_reuseport.h> 24 #include <net/addrconf.h> 25 26 #if IS_ENABLED(CONFIG_IPV6) 27 /* match_sk*_wildcard == true: IPV6_ADDR_ANY equals to any IPv6 addresses 28 * if IPv6 only, and any IPv4 addresses 29 * if not IPv6 only 30 * match_sk*_wildcard == false: addresses must be exactly the same, i.e. 31 * IPV6_ADDR_ANY only equals to IPV6_ADDR_ANY, 32 * and 0.0.0.0 equals to 0.0.0.0 only 33 */ 34 static bool ipv6_rcv_saddr_equal(const struct in6_addr *sk1_rcv_saddr6, 35 const struct in6_addr *sk2_rcv_saddr6, 36 __be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr, 37 bool sk1_ipv6only, bool sk2_ipv6only, 38 bool match_sk1_wildcard, 39 bool match_sk2_wildcard) 40 { 41 int addr_type = ipv6_addr_type(sk1_rcv_saddr6); 42 int addr_type2 = sk2_rcv_saddr6 ? ipv6_addr_type(sk2_rcv_saddr6) : IPV6_ADDR_MAPPED; 43 44 /* if both are mapped, treat as IPv4 */ 45 if (addr_type == IPV6_ADDR_MAPPED && addr_type2 == IPV6_ADDR_MAPPED) { 46 if (!sk2_ipv6only) { 47 if (sk1_rcv_saddr == sk2_rcv_saddr) 48 return true; 49 return (match_sk1_wildcard && !sk1_rcv_saddr) || 50 (match_sk2_wildcard && !sk2_rcv_saddr); 51 } 52 return false; 53 } 54 55 if (addr_type == IPV6_ADDR_ANY && addr_type2 == IPV6_ADDR_ANY) 56 return true; 57 58 if (addr_type2 == IPV6_ADDR_ANY && match_sk2_wildcard && 59 !(sk2_ipv6only && addr_type == IPV6_ADDR_MAPPED)) 60 return true; 61 62 if (addr_type == IPV6_ADDR_ANY && match_sk1_wildcard && 63 !(sk1_ipv6only && addr_type2 == IPV6_ADDR_MAPPED)) 64 return true; 65 66 if (sk2_rcv_saddr6 && 67 ipv6_addr_equal(sk1_rcv_saddr6, sk2_rcv_saddr6)) 68 return true; 69 70 return false; 71 } 72 #endif 73 74 /* match_sk*_wildcard == true: 0.0.0.0 equals to any IPv4 addresses 75 * match_sk*_wildcard == false: addresses must be exactly the same, i.e. 76 * 0.0.0.0 only equals to 0.0.0.0 77 */ 78 static bool ipv4_rcv_saddr_equal(__be32 sk1_rcv_saddr, __be32 sk2_rcv_saddr, 79 bool sk2_ipv6only, bool match_sk1_wildcard, 80 bool match_sk2_wildcard) 81 { 82 if (!sk2_ipv6only) { 83 if (sk1_rcv_saddr == sk2_rcv_saddr) 84 return true; 85 return (match_sk1_wildcard && !sk1_rcv_saddr) || 86 (match_sk2_wildcard && !sk2_rcv_saddr); 87 } 88 return false; 89 } 90 91 bool inet_rcv_saddr_equal(const struct sock *sk, const struct sock *sk2, 92 bool match_wildcard) 93 { 94 #if IS_ENABLED(CONFIG_IPV6) 95 if (sk->sk_family == AF_INET6) 96 return ipv6_rcv_saddr_equal(&sk->sk_v6_rcv_saddr, 97 inet6_rcv_saddr(sk2), 98 sk->sk_rcv_saddr, 99 sk2->sk_rcv_saddr, 100 ipv6_only_sock(sk), 101 ipv6_only_sock(sk2), 102 match_wildcard, 103 match_wildcard); 104 #endif 105 return ipv4_rcv_saddr_equal(sk->sk_rcv_saddr, sk2->sk_rcv_saddr, 106 ipv6_only_sock(sk2), match_wildcard, 107 match_wildcard); 108 } 109 EXPORT_SYMBOL(inet_rcv_saddr_equal); 110 111 bool inet_rcv_saddr_any(const struct sock *sk) 112 { 113 #if IS_ENABLED(CONFIG_IPV6) 114 if (sk->sk_family == AF_INET6) 115 return ipv6_addr_any(&sk->sk_v6_rcv_saddr); 116 #endif 117 return !sk->sk_rcv_saddr; 118 } 119 120 void inet_get_local_port_range(struct net *net, int *low, int *high) 121 { 122 unsigned int seq; 123 124 do { 125 seq = read_seqbegin(&net->ipv4.ip_local_ports.lock); 126 127 *low = net->ipv4.ip_local_ports.range[0]; 128 *high = net->ipv4.ip_local_ports.range[1]; 129 } while (read_seqretry(&net->ipv4.ip_local_ports.lock, seq)); 130 } 131 EXPORT_SYMBOL(inet_get_local_port_range); 132 133 static int inet_csk_bind_conflict(const struct sock *sk, 134 const struct inet_bind_bucket *tb, 135 bool relax, bool reuseport_ok) 136 { 137 struct sock *sk2; 138 bool reuseport_cb_ok; 139 bool reuse = sk->sk_reuse; 140 bool reuseport = !!sk->sk_reuseport; 141 struct sock_reuseport *reuseport_cb; 142 kuid_t uid = sock_i_uid((struct sock *)sk); 143 144 rcu_read_lock(); 145 reuseport_cb = rcu_dereference(sk->sk_reuseport_cb); 146 /* paired with WRITE_ONCE() in __reuseport_(add|detach)_closed_sock */ 147 reuseport_cb_ok = !reuseport_cb || READ_ONCE(reuseport_cb->num_closed_socks); 148 rcu_read_unlock(); 149 150 /* 151 * Unlike other sk lookup places we do not check 152 * for sk_net here, since _all_ the socks listed 153 * in tb->owners list belong to the same net - the 154 * one this bucket belongs to. 155 */ 156 157 sk_for_each_bound(sk2, &tb->owners) { 158 if (sk != sk2 && 159 (!sk->sk_bound_dev_if || 160 !sk2->sk_bound_dev_if || 161 sk->sk_bound_dev_if == sk2->sk_bound_dev_if)) { 162 if (reuse && sk2->sk_reuse && 163 sk2->sk_state != TCP_LISTEN) { 164 if ((!relax || 165 (!reuseport_ok && 166 reuseport && sk2->sk_reuseport && 167 reuseport_cb_ok && 168 (sk2->sk_state == TCP_TIME_WAIT || 169 uid_eq(uid, sock_i_uid(sk2))))) && 170 inet_rcv_saddr_equal(sk, sk2, true)) 171 break; 172 } else if (!reuseport_ok || 173 !reuseport || !sk2->sk_reuseport || 174 !reuseport_cb_ok || 175 (sk2->sk_state != TCP_TIME_WAIT && 176 !uid_eq(uid, sock_i_uid(sk2)))) { 177 if (inet_rcv_saddr_equal(sk, sk2, true)) 178 break; 179 } 180 } 181 } 182 return sk2 != NULL; 183 } 184 185 /* 186 * Find an open port number for the socket. Returns with the 187 * inet_bind_hashbucket lock held. 188 */ 189 static struct inet_bind_hashbucket * 190 inet_csk_find_open_port(struct sock *sk, struct inet_bind_bucket **tb_ret, int *port_ret) 191 { 192 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo; 193 int port = 0; 194 struct inet_bind_hashbucket *head; 195 struct net *net = sock_net(sk); 196 bool relax = false; 197 int i, low, high, attempt_half; 198 struct inet_bind_bucket *tb; 199 u32 remaining, offset; 200 int l3mdev; 201 202 l3mdev = inet_sk_bound_l3mdev(sk); 203 ports_exhausted: 204 attempt_half = (sk->sk_reuse == SK_CAN_REUSE) ? 1 : 0; 205 other_half_scan: 206 inet_get_local_port_range(net, &low, &high); 207 high++; /* [32768, 60999] -> [32768, 61000[ */ 208 if (high - low < 4) 209 attempt_half = 0; 210 if (attempt_half) { 211 int half = low + (((high - low) >> 2) << 1); 212 213 if (attempt_half == 1) 214 high = half; 215 else 216 low = half; 217 } 218 remaining = high - low; 219 if (likely(remaining > 1)) 220 remaining &= ~1U; 221 222 offset = prandom_u32() % remaining; 223 /* __inet_hash_connect() favors ports having @low parity 224 * We do the opposite to not pollute connect() users. 225 */ 226 offset |= 1U; 227 228 other_parity_scan: 229 port = low + offset; 230 for (i = 0; i < remaining; i += 2, port += 2) { 231 if (unlikely(port >= high)) 232 port -= remaining; 233 if (inet_is_local_reserved_port(net, port)) 234 continue; 235 head = &hinfo->bhash[inet_bhashfn(net, port, 236 hinfo->bhash_size)]; 237 spin_lock_bh(&head->lock); 238 inet_bind_bucket_for_each(tb, &head->chain) 239 if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && 240 tb->port == port) { 241 if (!inet_csk_bind_conflict(sk, tb, relax, false)) 242 goto success; 243 goto next_port; 244 } 245 tb = NULL; 246 goto success; 247 next_port: 248 spin_unlock_bh(&head->lock); 249 cond_resched(); 250 } 251 252 offset--; 253 if (!(offset & 1)) 254 goto other_parity_scan; 255 256 if (attempt_half == 1) { 257 /* OK we now try the upper half of the range */ 258 attempt_half = 2; 259 goto other_half_scan; 260 } 261 262 if (net->ipv4.sysctl_ip_autobind_reuse && !relax) { 263 /* We still have a chance to connect to different destinations */ 264 relax = true; 265 goto ports_exhausted; 266 } 267 return NULL; 268 success: 269 *port_ret = port; 270 *tb_ret = tb; 271 return head; 272 } 273 274 static inline int sk_reuseport_match(struct inet_bind_bucket *tb, 275 struct sock *sk) 276 { 277 kuid_t uid = sock_i_uid(sk); 278 279 if (tb->fastreuseport <= 0) 280 return 0; 281 if (!sk->sk_reuseport) 282 return 0; 283 if (rcu_access_pointer(sk->sk_reuseport_cb)) 284 return 0; 285 if (!uid_eq(tb->fastuid, uid)) 286 return 0; 287 /* We only need to check the rcv_saddr if this tb was once marked 288 * without fastreuseport and then was reset, as we can only know that 289 * the fast_*rcv_saddr doesn't have any conflicts with the socks on the 290 * owners list. 291 */ 292 if (tb->fastreuseport == FASTREUSEPORT_ANY) 293 return 1; 294 #if IS_ENABLED(CONFIG_IPV6) 295 if (tb->fast_sk_family == AF_INET6) 296 return ipv6_rcv_saddr_equal(&tb->fast_v6_rcv_saddr, 297 inet6_rcv_saddr(sk), 298 tb->fast_rcv_saddr, 299 sk->sk_rcv_saddr, 300 tb->fast_ipv6_only, 301 ipv6_only_sock(sk), true, false); 302 #endif 303 return ipv4_rcv_saddr_equal(tb->fast_rcv_saddr, sk->sk_rcv_saddr, 304 ipv6_only_sock(sk), true, false); 305 } 306 307 void inet_csk_update_fastreuse(struct inet_bind_bucket *tb, 308 struct sock *sk) 309 { 310 kuid_t uid = sock_i_uid(sk); 311 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN; 312 313 if (hlist_empty(&tb->owners)) { 314 tb->fastreuse = reuse; 315 if (sk->sk_reuseport) { 316 tb->fastreuseport = FASTREUSEPORT_ANY; 317 tb->fastuid = uid; 318 tb->fast_rcv_saddr = sk->sk_rcv_saddr; 319 tb->fast_ipv6_only = ipv6_only_sock(sk); 320 tb->fast_sk_family = sk->sk_family; 321 #if IS_ENABLED(CONFIG_IPV6) 322 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 323 #endif 324 } else { 325 tb->fastreuseport = 0; 326 } 327 } else { 328 if (!reuse) 329 tb->fastreuse = 0; 330 if (sk->sk_reuseport) { 331 /* We didn't match or we don't have fastreuseport set on 332 * the tb, but we have sk_reuseport set on this socket 333 * and we know that there are no bind conflicts with 334 * this socket in this tb, so reset our tb's reuseport 335 * settings so that any subsequent sockets that match 336 * our current socket will be put on the fast path. 337 * 338 * If we reset we need to set FASTREUSEPORT_STRICT so we 339 * do extra checking for all subsequent sk_reuseport 340 * socks. 341 */ 342 if (!sk_reuseport_match(tb, sk)) { 343 tb->fastreuseport = FASTREUSEPORT_STRICT; 344 tb->fastuid = uid; 345 tb->fast_rcv_saddr = sk->sk_rcv_saddr; 346 tb->fast_ipv6_only = ipv6_only_sock(sk); 347 tb->fast_sk_family = sk->sk_family; 348 #if IS_ENABLED(CONFIG_IPV6) 349 tb->fast_v6_rcv_saddr = sk->sk_v6_rcv_saddr; 350 #endif 351 } 352 } else { 353 tb->fastreuseport = 0; 354 } 355 } 356 } 357 358 /* Obtain a reference to a local port for the given sock, 359 * if snum is zero it means select any available local port. 360 * We try to allocate an odd port (and leave even ports for connect()) 361 */ 362 int inet_csk_get_port(struct sock *sk, unsigned short snum) 363 { 364 bool reuse = sk->sk_reuse && sk->sk_state != TCP_LISTEN; 365 struct inet_hashinfo *hinfo = sk->sk_prot->h.hashinfo; 366 int ret = 1, port = snum; 367 struct inet_bind_hashbucket *head; 368 struct net *net = sock_net(sk); 369 struct inet_bind_bucket *tb = NULL; 370 int l3mdev; 371 372 l3mdev = inet_sk_bound_l3mdev(sk); 373 374 if (!port) { 375 head = inet_csk_find_open_port(sk, &tb, &port); 376 if (!head) 377 return ret; 378 if (!tb) 379 goto tb_not_found; 380 goto success; 381 } 382 head = &hinfo->bhash[inet_bhashfn(net, port, 383 hinfo->bhash_size)]; 384 spin_lock_bh(&head->lock); 385 inet_bind_bucket_for_each(tb, &head->chain) 386 if (net_eq(ib_net(tb), net) && tb->l3mdev == l3mdev && 387 tb->port == port) 388 goto tb_found; 389 tb_not_found: 390 tb = inet_bind_bucket_create(hinfo->bind_bucket_cachep, 391 net, head, port, l3mdev); 392 if (!tb) 393 goto fail_unlock; 394 tb_found: 395 if (!hlist_empty(&tb->owners)) { 396 if (sk->sk_reuse == SK_FORCE_REUSE) 397 goto success; 398 399 if ((tb->fastreuse > 0 && reuse) || 400 sk_reuseport_match(tb, sk)) 401 goto success; 402 if (inet_csk_bind_conflict(sk, tb, true, true)) 403 goto fail_unlock; 404 } 405 success: 406 inet_csk_update_fastreuse(tb, sk); 407 408 if (!inet_csk(sk)->icsk_bind_hash) 409 inet_bind_hash(sk, tb, port); 410 WARN_ON(inet_csk(sk)->icsk_bind_hash != tb); 411 ret = 0; 412 413 fail_unlock: 414 spin_unlock_bh(&head->lock); 415 return ret; 416 } 417 EXPORT_SYMBOL_GPL(inet_csk_get_port); 418 419 /* 420 * Wait for an incoming connection, avoid race conditions. This must be called 421 * with the socket locked. 422 */ 423 static int inet_csk_wait_for_connect(struct sock *sk, long timeo) 424 { 425 struct inet_connection_sock *icsk = inet_csk(sk); 426 DEFINE_WAIT(wait); 427 int err; 428 429 /* 430 * True wake-one mechanism for incoming connections: only 431 * one process gets woken up, not the 'whole herd'. 432 * Since we do not 'race & poll' for established sockets 433 * anymore, the common case will execute the loop only once. 434 * 435 * Subtle issue: "add_wait_queue_exclusive()" will be added 436 * after any current non-exclusive waiters, and we know that 437 * it will always _stay_ after any new non-exclusive waiters 438 * because all non-exclusive waiters are added at the 439 * beginning of the wait-queue. As such, it's ok to "drop" 440 * our exclusiveness temporarily when we get woken up without 441 * having to remove and re-insert us on the wait queue. 442 */ 443 for (;;) { 444 prepare_to_wait_exclusive(sk_sleep(sk), &wait, 445 TASK_INTERRUPTIBLE); 446 release_sock(sk); 447 if (reqsk_queue_empty(&icsk->icsk_accept_queue)) 448 timeo = schedule_timeout(timeo); 449 sched_annotate_sleep(); 450 lock_sock(sk); 451 err = 0; 452 if (!reqsk_queue_empty(&icsk->icsk_accept_queue)) 453 break; 454 err = -EINVAL; 455 if (sk->sk_state != TCP_LISTEN) 456 break; 457 err = sock_intr_errno(timeo); 458 if (signal_pending(current)) 459 break; 460 err = -EAGAIN; 461 if (!timeo) 462 break; 463 } 464 finish_wait(sk_sleep(sk), &wait); 465 return err; 466 } 467 468 /* 469 * This will accept the next outstanding connection. 470 */ 471 struct sock *inet_csk_accept(struct sock *sk, int flags, int *err, bool kern) 472 { 473 struct inet_connection_sock *icsk = inet_csk(sk); 474 struct request_sock_queue *queue = &icsk->icsk_accept_queue; 475 struct request_sock *req; 476 struct sock *newsk; 477 int error; 478 479 lock_sock(sk); 480 481 /* We need to make sure that this socket is listening, 482 * and that it has something pending. 483 */ 484 error = -EINVAL; 485 if (sk->sk_state != TCP_LISTEN) 486 goto out_err; 487 488 /* Find already established connection */ 489 if (reqsk_queue_empty(queue)) { 490 long timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK); 491 492 /* If this is a non blocking socket don't sleep */ 493 error = -EAGAIN; 494 if (!timeo) 495 goto out_err; 496 497 error = inet_csk_wait_for_connect(sk, timeo); 498 if (error) 499 goto out_err; 500 } 501 req = reqsk_queue_remove(queue, sk); 502 newsk = req->sk; 503 504 if (sk->sk_protocol == IPPROTO_TCP && 505 tcp_rsk(req)->tfo_listener) { 506 spin_lock_bh(&queue->fastopenq.lock); 507 if (tcp_rsk(req)->tfo_listener) { 508 /* We are still waiting for the final ACK from 3WHS 509 * so can't free req now. Instead, we set req->sk to 510 * NULL to signify that the child socket is taken 511 * so reqsk_fastopen_remove() will free the req 512 * when 3WHS finishes (or is aborted). 513 */ 514 req->sk = NULL; 515 req = NULL; 516 } 517 spin_unlock_bh(&queue->fastopenq.lock); 518 } 519 520 out: 521 release_sock(sk); 522 if (newsk && mem_cgroup_sockets_enabled) { 523 int amt; 524 525 /* atomically get the memory usage, set and charge the 526 * newsk->sk_memcg. 527 */ 528 lock_sock(newsk); 529 530 /* The socket has not been accepted yet, no need to look at 531 * newsk->sk_wmem_queued. 532 */ 533 amt = sk_mem_pages(newsk->sk_forward_alloc + 534 atomic_read(&newsk->sk_rmem_alloc)); 535 mem_cgroup_sk_alloc(newsk); 536 if (newsk->sk_memcg && amt) 537 mem_cgroup_charge_skmem(newsk->sk_memcg, amt, 538 GFP_KERNEL | __GFP_NOFAIL); 539 540 release_sock(newsk); 541 } 542 if (req) 543 reqsk_put(req); 544 return newsk; 545 out_err: 546 newsk = NULL; 547 req = NULL; 548 *err = error; 549 goto out; 550 } 551 EXPORT_SYMBOL(inet_csk_accept); 552 553 /* 554 * Using different timers for retransmit, delayed acks and probes 555 * We may wish use just one timer maintaining a list of expire jiffies 556 * to optimize. 557 */ 558 void inet_csk_init_xmit_timers(struct sock *sk, 559 void (*retransmit_handler)(struct timer_list *t), 560 void (*delack_handler)(struct timer_list *t), 561 void (*keepalive_handler)(struct timer_list *t)) 562 { 563 struct inet_connection_sock *icsk = inet_csk(sk); 564 565 timer_setup(&icsk->icsk_retransmit_timer, retransmit_handler, 0); 566 timer_setup(&icsk->icsk_delack_timer, delack_handler, 0); 567 timer_setup(&sk->sk_timer, keepalive_handler, 0); 568 icsk->icsk_pending = icsk->icsk_ack.pending = 0; 569 } 570 EXPORT_SYMBOL(inet_csk_init_xmit_timers); 571 572 void inet_csk_clear_xmit_timers(struct sock *sk) 573 { 574 struct inet_connection_sock *icsk = inet_csk(sk); 575 576 icsk->icsk_pending = icsk->icsk_ack.pending = 0; 577 578 sk_stop_timer(sk, &icsk->icsk_retransmit_timer); 579 sk_stop_timer(sk, &icsk->icsk_delack_timer); 580 sk_stop_timer(sk, &sk->sk_timer); 581 } 582 EXPORT_SYMBOL(inet_csk_clear_xmit_timers); 583 584 void inet_csk_delete_keepalive_timer(struct sock *sk) 585 { 586 sk_stop_timer(sk, &sk->sk_timer); 587 } 588 EXPORT_SYMBOL(inet_csk_delete_keepalive_timer); 589 590 void inet_csk_reset_keepalive_timer(struct sock *sk, unsigned long len) 591 { 592 sk_reset_timer(sk, &sk->sk_timer, jiffies + len); 593 } 594 EXPORT_SYMBOL(inet_csk_reset_keepalive_timer); 595 596 struct dst_entry *inet_csk_route_req(const struct sock *sk, 597 struct flowi4 *fl4, 598 const struct request_sock *req) 599 { 600 const struct inet_request_sock *ireq = inet_rsk(req); 601 struct net *net = read_pnet(&ireq->ireq_net); 602 struct ip_options_rcu *opt; 603 struct rtable *rt; 604 605 rcu_read_lock(); 606 opt = rcu_dereference(ireq->ireq_opt); 607 608 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, 609 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 610 sk->sk_protocol, inet_sk_flowi_flags(sk), 611 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr, 612 ireq->ir_loc_addr, ireq->ir_rmt_port, 613 htons(ireq->ir_num), sk->sk_uid); 614 security_req_classify_flow(req, flowi4_to_flowi_common(fl4)); 615 rt = ip_route_output_flow(net, fl4, sk); 616 if (IS_ERR(rt)) 617 goto no_route; 618 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) 619 goto route_err; 620 rcu_read_unlock(); 621 return &rt->dst; 622 623 route_err: 624 ip_rt_put(rt); 625 no_route: 626 rcu_read_unlock(); 627 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 628 return NULL; 629 } 630 EXPORT_SYMBOL_GPL(inet_csk_route_req); 631 632 struct dst_entry *inet_csk_route_child_sock(const struct sock *sk, 633 struct sock *newsk, 634 const struct request_sock *req) 635 { 636 const struct inet_request_sock *ireq = inet_rsk(req); 637 struct net *net = read_pnet(&ireq->ireq_net); 638 struct inet_sock *newinet = inet_sk(newsk); 639 struct ip_options_rcu *opt; 640 struct flowi4 *fl4; 641 struct rtable *rt; 642 643 opt = rcu_dereference(ireq->ireq_opt); 644 fl4 = &newinet->cork.fl.u.ip4; 645 646 flowi4_init_output(fl4, ireq->ir_iif, ireq->ir_mark, 647 RT_CONN_FLAGS(sk), RT_SCOPE_UNIVERSE, 648 sk->sk_protocol, inet_sk_flowi_flags(sk), 649 (opt && opt->opt.srr) ? opt->opt.faddr : ireq->ir_rmt_addr, 650 ireq->ir_loc_addr, ireq->ir_rmt_port, 651 htons(ireq->ir_num), sk->sk_uid); 652 security_req_classify_flow(req, flowi4_to_flowi_common(fl4)); 653 rt = ip_route_output_flow(net, fl4, sk); 654 if (IS_ERR(rt)) 655 goto no_route; 656 if (opt && opt->opt.is_strictroute && rt->rt_uses_gateway) 657 goto route_err; 658 return &rt->dst; 659 660 route_err: 661 ip_rt_put(rt); 662 no_route: 663 __IP_INC_STATS(net, IPSTATS_MIB_OUTNOROUTES); 664 return NULL; 665 } 666 EXPORT_SYMBOL_GPL(inet_csk_route_child_sock); 667 668 /* Decide when to expire the request and when to resend SYN-ACK */ 669 static void syn_ack_recalc(struct request_sock *req, 670 const int max_syn_ack_retries, 671 const u8 rskq_defer_accept, 672 int *expire, int *resend) 673 { 674 if (!rskq_defer_accept) { 675 *expire = req->num_timeout >= max_syn_ack_retries; 676 *resend = 1; 677 return; 678 } 679 *expire = req->num_timeout >= max_syn_ack_retries && 680 (!inet_rsk(req)->acked || req->num_timeout >= rskq_defer_accept); 681 /* Do not resend while waiting for data after ACK, 682 * start to resend on end of deferring period to give 683 * last chance for data or ACK to create established socket. 684 */ 685 *resend = !inet_rsk(req)->acked || 686 req->num_timeout >= rskq_defer_accept - 1; 687 } 688 689 int inet_rtx_syn_ack(const struct sock *parent, struct request_sock *req) 690 { 691 int err = req->rsk_ops->rtx_syn_ack(parent, req); 692 693 if (!err) 694 req->num_retrans++; 695 return err; 696 } 697 EXPORT_SYMBOL(inet_rtx_syn_ack); 698 699 static struct request_sock *inet_reqsk_clone(struct request_sock *req, 700 struct sock *sk) 701 { 702 struct sock *req_sk, *nreq_sk; 703 struct request_sock *nreq; 704 705 nreq = kmem_cache_alloc(req->rsk_ops->slab, GFP_ATOMIC | __GFP_NOWARN); 706 if (!nreq) { 707 __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE); 708 709 /* paired with refcount_inc_not_zero() in reuseport_migrate_sock() */ 710 sock_put(sk); 711 return NULL; 712 } 713 714 req_sk = req_to_sk(req); 715 nreq_sk = req_to_sk(nreq); 716 717 memcpy(nreq_sk, req_sk, 718 offsetof(struct sock, sk_dontcopy_begin)); 719 memcpy(&nreq_sk->sk_dontcopy_end, &req_sk->sk_dontcopy_end, 720 req->rsk_ops->obj_size - offsetof(struct sock, sk_dontcopy_end)); 721 722 sk_node_init(&nreq_sk->sk_node); 723 nreq_sk->sk_tx_queue_mapping = req_sk->sk_tx_queue_mapping; 724 #ifdef CONFIG_SOCK_RX_QUEUE_MAPPING 725 nreq_sk->sk_rx_queue_mapping = req_sk->sk_rx_queue_mapping; 726 #endif 727 nreq_sk->sk_incoming_cpu = req_sk->sk_incoming_cpu; 728 729 nreq->rsk_listener = sk; 730 731 /* We need not acquire fastopenq->lock 732 * because the child socket is locked in inet_csk_listen_stop(). 733 */ 734 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(nreq)->tfo_listener) 735 rcu_assign_pointer(tcp_sk(nreq->sk)->fastopen_rsk, nreq); 736 737 return nreq; 738 } 739 740 static void reqsk_queue_migrated(struct request_sock_queue *queue, 741 const struct request_sock *req) 742 { 743 if (req->num_timeout == 0) 744 atomic_inc(&queue->young); 745 atomic_inc(&queue->qlen); 746 } 747 748 static void reqsk_migrate_reset(struct request_sock *req) 749 { 750 req->saved_syn = NULL; 751 #if IS_ENABLED(CONFIG_IPV6) 752 inet_rsk(req)->ipv6_opt = NULL; 753 inet_rsk(req)->pktopts = NULL; 754 #else 755 inet_rsk(req)->ireq_opt = NULL; 756 #endif 757 } 758 759 /* return true if req was found in the ehash table */ 760 static bool reqsk_queue_unlink(struct request_sock *req) 761 { 762 struct inet_hashinfo *hashinfo = req_to_sk(req)->sk_prot->h.hashinfo; 763 bool found = false; 764 765 if (sk_hashed(req_to_sk(req))) { 766 spinlock_t *lock = inet_ehash_lockp(hashinfo, req->rsk_hash); 767 768 spin_lock(lock); 769 found = __sk_nulls_del_node_init_rcu(req_to_sk(req)); 770 spin_unlock(lock); 771 } 772 if (timer_pending(&req->rsk_timer) && del_timer_sync(&req->rsk_timer)) 773 reqsk_put(req); 774 return found; 775 } 776 777 bool inet_csk_reqsk_queue_drop(struct sock *sk, struct request_sock *req) 778 { 779 bool unlinked = reqsk_queue_unlink(req); 780 781 if (unlinked) { 782 reqsk_queue_removed(&inet_csk(sk)->icsk_accept_queue, req); 783 reqsk_put(req); 784 } 785 return unlinked; 786 } 787 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop); 788 789 void inet_csk_reqsk_queue_drop_and_put(struct sock *sk, struct request_sock *req) 790 { 791 inet_csk_reqsk_queue_drop(sk, req); 792 reqsk_put(req); 793 } 794 EXPORT_SYMBOL(inet_csk_reqsk_queue_drop_and_put); 795 796 static void reqsk_timer_handler(struct timer_list *t) 797 { 798 struct request_sock *req = from_timer(req, t, rsk_timer); 799 struct request_sock *nreq = NULL, *oreq = req; 800 struct sock *sk_listener = req->rsk_listener; 801 struct inet_connection_sock *icsk; 802 struct request_sock_queue *queue; 803 struct net *net; 804 int max_syn_ack_retries, qlen, expire = 0, resend = 0; 805 806 if (inet_sk_state_load(sk_listener) != TCP_LISTEN) { 807 struct sock *nsk; 808 809 nsk = reuseport_migrate_sock(sk_listener, req_to_sk(req), NULL); 810 if (!nsk) 811 goto drop; 812 813 nreq = inet_reqsk_clone(req, nsk); 814 if (!nreq) 815 goto drop; 816 817 /* The new timer for the cloned req can decrease the 2 818 * by calling inet_csk_reqsk_queue_drop_and_put(), so 819 * hold another count to prevent use-after-free and 820 * call reqsk_put() just before return. 821 */ 822 refcount_set(&nreq->rsk_refcnt, 2 + 1); 823 timer_setup(&nreq->rsk_timer, reqsk_timer_handler, TIMER_PINNED); 824 reqsk_queue_migrated(&inet_csk(nsk)->icsk_accept_queue, req); 825 826 req = nreq; 827 sk_listener = nsk; 828 } 829 830 icsk = inet_csk(sk_listener); 831 net = sock_net(sk_listener); 832 max_syn_ack_retries = icsk->icsk_syn_retries ? : net->ipv4.sysctl_tcp_synack_retries; 833 /* Normally all the openreqs are young and become mature 834 * (i.e. converted to established socket) for first timeout. 835 * If synack was not acknowledged for 1 second, it means 836 * one of the following things: synack was lost, ack was lost, 837 * rtt is high or nobody planned to ack (i.e. synflood). 838 * When server is a bit loaded, queue is populated with old 839 * open requests, reducing effective size of queue. 840 * When server is well loaded, queue size reduces to zero 841 * after several minutes of work. It is not synflood, 842 * it is normal operation. The solution is pruning 843 * too old entries overriding normal timeout, when 844 * situation becomes dangerous. 845 * 846 * Essentially, we reserve half of room for young 847 * embrions; and abort old ones without pity, if old 848 * ones are about to clog our table. 849 */ 850 queue = &icsk->icsk_accept_queue; 851 qlen = reqsk_queue_len(queue); 852 if ((qlen << 1) > max(8U, READ_ONCE(sk_listener->sk_max_ack_backlog))) { 853 int young = reqsk_queue_len_young(queue) << 1; 854 855 while (max_syn_ack_retries > 2) { 856 if (qlen < young) 857 break; 858 max_syn_ack_retries--; 859 young <<= 1; 860 } 861 } 862 syn_ack_recalc(req, max_syn_ack_retries, READ_ONCE(queue->rskq_defer_accept), 863 &expire, &resend); 864 req->rsk_ops->syn_ack_timeout(req); 865 if (!expire && 866 (!resend || 867 !inet_rtx_syn_ack(sk_listener, req) || 868 inet_rsk(req)->acked)) { 869 unsigned long timeo; 870 871 if (req->num_timeout++ == 0) 872 atomic_dec(&queue->young); 873 timeo = min(TCP_TIMEOUT_INIT << req->num_timeout, TCP_RTO_MAX); 874 mod_timer(&req->rsk_timer, jiffies + timeo); 875 876 if (!nreq) 877 return; 878 879 if (!inet_ehash_insert(req_to_sk(nreq), req_to_sk(oreq), NULL)) { 880 /* delete timer */ 881 inet_csk_reqsk_queue_drop(sk_listener, nreq); 882 goto no_ownership; 883 } 884 885 __NET_INC_STATS(net, LINUX_MIB_TCPMIGRATEREQSUCCESS); 886 reqsk_migrate_reset(oreq); 887 reqsk_queue_removed(&inet_csk(oreq->rsk_listener)->icsk_accept_queue, oreq); 888 reqsk_put(oreq); 889 890 reqsk_put(nreq); 891 return; 892 } 893 894 /* Even if we can clone the req, we may need not retransmit any more 895 * SYN+ACKs (nreq->num_timeout > max_syn_ack_retries, etc), or another 896 * CPU may win the "own_req" race so that inet_ehash_insert() fails. 897 */ 898 if (nreq) { 899 __NET_INC_STATS(net, LINUX_MIB_TCPMIGRATEREQFAILURE); 900 no_ownership: 901 reqsk_migrate_reset(nreq); 902 reqsk_queue_removed(queue, nreq); 903 __reqsk_free(nreq); 904 } 905 906 drop: 907 inet_csk_reqsk_queue_drop_and_put(oreq->rsk_listener, oreq); 908 } 909 910 static void reqsk_queue_hash_req(struct request_sock *req, 911 unsigned long timeout) 912 { 913 timer_setup(&req->rsk_timer, reqsk_timer_handler, TIMER_PINNED); 914 mod_timer(&req->rsk_timer, jiffies + timeout); 915 916 inet_ehash_insert(req_to_sk(req), NULL, NULL); 917 /* before letting lookups find us, make sure all req fields 918 * are committed to memory and refcnt initialized. 919 */ 920 smp_wmb(); 921 refcount_set(&req->rsk_refcnt, 2 + 1); 922 } 923 924 void inet_csk_reqsk_queue_hash_add(struct sock *sk, struct request_sock *req, 925 unsigned long timeout) 926 { 927 reqsk_queue_hash_req(req, timeout); 928 inet_csk_reqsk_queue_added(sk); 929 } 930 EXPORT_SYMBOL_GPL(inet_csk_reqsk_queue_hash_add); 931 932 static void inet_clone_ulp(const struct request_sock *req, struct sock *newsk, 933 const gfp_t priority) 934 { 935 struct inet_connection_sock *icsk = inet_csk(newsk); 936 937 if (!icsk->icsk_ulp_ops) 938 return; 939 940 if (icsk->icsk_ulp_ops->clone) 941 icsk->icsk_ulp_ops->clone(req, newsk, priority); 942 } 943 944 /** 945 * inet_csk_clone_lock - clone an inet socket, and lock its clone 946 * @sk: the socket to clone 947 * @req: request_sock 948 * @priority: for allocation (%GFP_KERNEL, %GFP_ATOMIC, etc) 949 * 950 * Caller must unlock socket even in error path (bh_unlock_sock(newsk)) 951 */ 952 struct sock *inet_csk_clone_lock(const struct sock *sk, 953 const struct request_sock *req, 954 const gfp_t priority) 955 { 956 struct sock *newsk = sk_clone_lock(sk, priority); 957 958 if (newsk) { 959 struct inet_connection_sock *newicsk = inet_csk(newsk); 960 961 inet_sk_set_state(newsk, TCP_SYN_RECV); 962 newicsk->icsk_bind_hash = NULL; 963 964 inet_sk(newsk)->inet_dport = inet_rsk(req)->ir_rmt_port; 965 inet_sk(newsk)->inet_num = inet_rsk(req)->ir_num; 966 inet_sk(newsk)->inet_sport = htons(inet_rsk(req)->ir_num); 967 968 /* listeners have SOCK_RCU_FREE, not the children */ 969 sock_reset_flag(newsk, SOCK_RCU_FREE); 970 971 inet_sk(newsk)->mc_list = NULL; 972 973 newsk->sk_mark = inet_rsk(req)->ir_mark; 974 atomic64_set(&newsk->sk_cookie, 975 atomic64_read(&inet_rsk(req)->ir_cookie)); 976 977 newicsk->icsk_retransmits = 0; 978 newicsk->icsk_backoff = 0; 979 newicsk->icsk_probes_out = 0; 980 newicsk->icsk_probes_tstamp = 0; 981 982 /* Deinitialize accept_queue to trap illegal accesses. */ 983 memset(&newicsk->icsk_accept_queue, 0, sizeof(newicsk->icsk_accept_queue)); 984 985 inet_clone_ulp(req, newsk, priority); 986 987 security_inet_csk_clone(newsk, req); 988 } 989 return newsk; 990 } 991 EXPORT_SYMBOL_GPL(inet_csk_clone_lock); 992 993 /* 994 * At this point, there should be no process reference to this 995 * socket, and thus no user references at all. Therefore we 996 * can assume the socket waitqueue is inactive and nobody will 997 * try to jump onto it. 998 */ 999 void inet_csk_destroy_sock(struct sock *sk) 1000 { 1001 WARN_ON(sk->sk_state != TCP_CLOSE); 1002 WARN_ON(!sock_flag(sk, SOCK_DEAD)); 1003 1004 /* It cannot be in hash table! */ 1005 WARN_ON(!sk_unhashed(sk)); 1006 1007 /* If it has not 0 inet_sk(sk)->inet_num, it must be bound */ 1008 WARN_ON(inet_sk(sk)->inet_num && !inet_csk(sk)->icsk_bind_hash); 1009 1010 sk->sk_prot->destroy(sk); 1011 1012 sk_stream_kill_queues(sk); 1013 1014 xfrm_sk_free_policy(sk); 1015 1016 sk_refcnt_debug_release(sk); 1017 1018 this_cpu_dec(*sk->sk_prot->orphan_count); 1019 1020 sock_put(sk); 1021 } 1022 EXPORT_SYMBOL(inet_csk_destroy_sock); 1023 1024 /* This function allows to force a closure of a socket after the call to 1025 * tcp/dccp_create_openreq_child(). 1026 */ 1027 void inet_csk_prepare_forced_close(struct sock *sk) 1028 __releases(&sk->sk_lock.slock) 1029 { 1030 /* sk_clone_lock locked the socket and set refcnt to 2 */ 1031 bh_unlock_sock(sk); 1032 sock_put(sk); 1033 inet_csk_prepare_for_destroy_sock(sk); 1034 inet_sk(sk)->inet_num = 0; 1035 } 1036 EXPORT_SYMBOL(inet_csk_prepare_forced_close); 1037 1038 int inet_csk_listen_start(struct sock *sk) 1039 { 1040 struct inet_connection_sock *icsk = inet_csk(sk); 1041 struct inet_sock *inet = inet_sk(sk); 1042 int err = -EADDRINUSE; 1043 1044 reqsk_queue_alloc(&icsk->icsk_accept_queue); 1045 1046 sk->sk_ack_backlog = 0; 1047 inet_csk_delack_init(sk); 1048 1049 /* There is race window here: we announce ourselves listening, 1050 * but this transition is still not validated by get_port(). 1051 * It is OK, because this socket enters to hash table only 1052 * after validation is complete. 1053 */ 1054 inet_sk_state_store(sk, TCP_LISTEN); 1055 if (!sk->sk_prot->get_port(sk, inet->inet_num)) { 1056 inet->inet_sport = htons(inet->inet_num); 1057 1058 sk_dst_reset(sk); 1059 err = sk->sk_prot->hash(sk); 1060 1061 if (likely(!err)) 1062 return 0; 1063 } 1064 1065 inet_sk_set_state(sk, TCP_CLOSE); 1066 return err; 1067 } 1068 EXPORT_SYMBOL_GPL(inet_csk_listen_start); 1069 1070 static void inet_child_forget(struct sock *sk, struct request_sock *req, 1071 struct sock *child) 1072 { 1073 sk->sk_prot->disconnect(child, O_NONBLOCK); 1074 1075 sock_orphan(child); 1076 1077 this_cpu_inc(*sk->sk_prot->orphan_count); 1078 1079 if (sk->sk_protocol == IPPROTO_TCP && tcp_rsk(req)->tfo_listener) { 1080 BUG_ON(rcu_access_pointer(tcp_sk(child)->fastopen_rsk) != req); 1081 BUG_ON(sk != req->rsk_listener); 1082 1083 /* Paranoid, to prevent race condition if 1084 * an inbound pkt destined for child is 1085 * blocked by sock lock in tcp_v4_rcv(). 1086 * Also to satisfy an assertion in 1087 * tcp_v4_destroy_sock(). 1088 */ 1089 RCU_INIT_POINTER(tcp_sk(child)->fastopen_rsk, NULL); 1090 } 1091 inet_csk_destroy_sock(child); 1092 } 1093 1094 struct sock *inet_csk_reqsk_queue_add(struct sock *sk, 1095 struct request_sock *req, 1096 struct sock *child) 1097 { 1098 struct request_sock_queue *queue = &inet_csk(sk)->icsk_accept_queue; 1099 1100 spin_lock(&queue->rskq_lock); 1101 if (unlikely(sk->sk_state != TCP_LISTEN)) { 1102 inet_child_forget(sk, req, child); 1103 child = NULL; 1104 } else { 1105 req->sk = child; 1106 req->dl_next = NULL; 1107 if (queue->rskq_accept_head == NULL) 1108 WRITE_ONCE(queue->rskq_accept_head, req); 1109 else 1110 queue->rskq_accept_tail->dl_next = req; 1111 queue->rskq_accept_tail = req; 1112 sk_acceptq_added(sk); 1113 } 1114 spin_unlock(&queue->rskq_lock); 1115 return child; 1116 } 1117 EXPORT_SYMBOL(inet_csk_reqsk_queue_add); 1118 1119 struct sock *inet_csk_complete_hashdance(struct sock *sk, struct sock *child, 1120 struct request_sock *req, bool own_req) 1121 { 1122 if (own_req) { 1123 inet_csk_reqsk_queue_drop(req->rsk_listener, req); 1124 reqsk_queue_removed(&inet_csk(req->rsk_listener)->icsk_accept_queue, req); 1125 1126 if (sk != req->rsk_listener) { 1127 /* another listening sk has been selected, 1128 * migrate the req to it. 1129 */ 1130 struct request_sock *nreq; 1131 1132 /* hold a refcnt for the nreq->rsk_listener 1133 * which is assigned in inet_reqsk_clone() 1134 */ 1135 sock_hold(sk); 1136 nreq = inet_reqsk_clone(req, sk); 1137 if (!nreq) { 1138 inet_child_forget(sk, req, child); 1139 goto child_put; 1140 } 1141 1142 refcount_set(&nreq->rsk_refcnt, 1); 1143 if (inet_csk_reqsk_queue_add(sk, nreq, child)) { 1144 __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQSUCCESS); 1145 reqsk_migrate_reset(req); 1146 reqsk_put(req); 1147 return child; 1148 } 1149 1150 __NET_INC_STATS(sock_net(sk), LINUX_MIB_TCPMIGRATEREQFAILURE); 1151 reqsk_migrate_reset(nreq); 1152 __reqsk_free(nreq); 1153 } else if (inet_csk_reqsk_queue_add(sk, req, child)) { 1154 return child; 1155 } 1156 } 1157 /* Too bad, another child took ownership of the request, undo. */ 1158 child_put: 1159 bh_unlock_sock(child); 1160 sock_put(child); 1161 return NULL; 1162 } 1163 EXPORT_SYMBOL(inet_csk_complete_hashdance); 1164 1165 /* 1166 * This routine closes sockets which have been at least partially 1167 * opened, but not yet accepted. 1168 */ 1169 void inet_csk_listen_stop(struct sock *sk) 1170 { 1171 struct inet_connection_sock *icsk = inet_csk(sk); 1172 struct request_sock_queue *queue = &icsk->icsk_accept_queue; 1173 struct request_sock *next, *req; 1174 1175 /* Following specs, it would be better either to send FIN 1176 * (and enter FIN-WAIT-1, it is normal close) 1177 * or to send active reset (abort). 1178 * Certainly, it is pretty dangerous while synflood, but it is 1179 * bad justification for our negligence 8) 1180 * To be honest, we are not able to make either 1181 * of the variants now. --ANK 1182 */ 1183 while ((req = reqsk_queue_remove(queue, sk)) != NULL) { 1184 struct sock *child = req->sk, *nsk; 1185 struct request_sock *nreq; 1186 1187 local_bh_disable(); 1188 bh_lock_sock(child); 1189 WARN_ON(sock_owned_by_user(child)); 1190 sock_hold(child); 1191 1192 nsk = reuseport_migrate_sock(sk, child, NULL); 1193 if (nsk) { 1194 nreq = inet_reqsk_clone(req, nsk); 1195 if (nreq) { 1196 refcount_set(&nreq->rsk_refcnt, 1); 1197 1198 if (inet_csk_reqsk_queue_add(nsk, nreq, child)) { 1199 __NET_INC_STATS(sock_net(nsk), 1200 LINUX_MIB_TCPMIGRATEREQSUCCESS); 1201 reqsk_migrate_reset(req); 1202 } else { 1203 __NET_INC_STATS(sock_net(nsk), 1204 LINUX_MIB_TCPMIGRATEREQFAILURE); 1205 reqsk_migrate_reset(nreq); 1206 __reqsk_free(nreq); 1207 } 1208 1209 /* inet_csk_reqsk_queue_add() has already 1210 * called inet_child_forget() on failure case. 1211 */ 1212 goto skip_child_forget; 1213 } 1214 } 1215 1216 inet_child_forget(sk, req, child); 1217 skip_child_forget: 1218 reqsk_put(req); 1219 bh_unlock_sock(child); 1220 local_bh_enable(); 1221 sock_put(child); 1222 1223 cond_resched(); 1224 } 1225 if (queue->fastopenq.rskq_rst_head) { 1226 /* Free all the reqs queued in rskq_rst_head. */ 1227 spin_lock_bh(&queue->fastopenq.lock); 1228 req = queue->fastopenq.rskq_rst_head; 1229 queue->fastopenq.rskq_rst_head = NULL; 1230 spin_unlock_bh(&queue->fastopenq.lock); 1231 while (req != NULL) { 1232 next = req->dl_next; 1233 reqsk_put(req); 1234 req = next; 1235 } 1236 } 1237 WARN_ON_ONCE(sk->sk_ack_backlog); 1238 } 1239 EXPORT_SYMBOL_GPL(inet_csk_listen_stop); 1240 1241 void inet_csk_addr2sockaddr(struct sock *sk, struct sockaddr *uaddr) 1242 { 1243 struct sockaddr_in *sin = (struct sockaddr_in *)uaddr; 1244 const struct inet_sock *inet = inet_sk(sk); 1245 1246 sin->sin_family = AF_INET; 1247 sin->sin_addr.s_addr = inet->inet_daddr; 1248 sin->sin_port = inet->inet_dport; 1249 } 1250 EXPORT_SYMBOL_GPL(inet_csk_addr2sockaddr); 1251 1252 static struct dst_entry *inet_csk_rebuild_route(struct sock *sk, struct flowi *fl) 1253 { 1254 const struct inet_sock *inet = inet_sk(sk); 1255 const struct ip_options_rcu *inet_opt; 1256 __be32 daddr = inet->inet_daddr; 1257 struct flowi4 *fl4; 1258 struct rtable *rt; 1259 1260 rcu_read_lock(); 1261 inet_opt = rcu_dereference(inet->inet_opt); 1262 if (inet_opt && inet_opt->opt.srr) 1263 daddr = inet_opt->opt.faddr; 1264 fl4 = &fl->u.ip4; 1265 rt = ip_route_output_ports(sock_net(sk), fl4, sk, daddr, 1266 inet->inet_saddr, inet->inet_dport, 1267 inet->inet_sport, sk->sk_protocol, 1268 RT_CONN_FLAGS(sk), sk->sk_bound_dev_if); 1269 if (IS_ERR(rt)) 1270 rt = NULL; 1271 if (rt) 1272 sk_setup_caps(sk, &rt->dst); 1273 rcu_read_unlock(); 1274 1275 return &rt->dst; 1276 } 1277 1278 struct dst_entry *inet_csk_update_pmtu(struct sock *sk, u32 mtu) 1279 { 1280 struct dst_entry *dst = __sk_dst_check(sk, 0); 1281 struct inet_sock *inet = inet_sk(sk); 1282 1283 if (!dst) { 1284 dst = inet_csk_rebuild_route(sk, &inet->cork.fl); 1285 if (!dst) 1286 goto out; 1287 } 1288 dst->ops->update_pmtu(dst, sk, NULL, mtu, true); 1289 1290 dst = __sk_dst_check(sk, 0); 1291 if (!dst) 1292 dst = inet_csk_rebuild_route(sk, &inet->cork.fl); 1293 out: 1294 return dst; 1295 } 1296 EXPORT_SYMBOL_GPL(inet_csk_update_pmtu); 1297