1 // SPDX-License-Identifier: GPL-2.0-only 2 /****************************************************************************** 3 ******************************************************************************* 4 ** 5 ** Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. 6 ** Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved. 7 ** 8 ** 9 ******************************************************************************* 10 ******************************************************************************/ 11 12 /* 13 * lowcomms.c 14 * 15 * This is the "low-level" comms layer. 16 * 17 * It is responsible for sending/receiving messages 18 * from other nodes in the cluster. 19 * 20 * Cluster nodes are referred to by their nodeids. nodeids are 21 * simply 32 bit numbers to the locking module - if they need to 22 * be expanded for the cluster infrastructure then that is its 23 * responsibility. It is this layer's 24 * responsibility to resolve these into IP address or 25 * whatever it needs for inter-node communication. 26 * 27 * The comms level is two kernel threads that deal mainly with 28 * the receiving of messages from other nodes and passing them 29 * up to the mid-level comms layer (which understands the 30 * message format) for execution by the locking core, and 31 * a send thread which does all the setting up of connections 32 * to remote nodes and the sending of data. Threads are not allowed 33 * to send their own data because it may cause them to wait in times 34 * of high load. Also, this way, the sending thread can collect together 35 * messages bound for one node and send them in one block. 36 * 37 * lowcomms will choose to use either TCP or SCTP as its transport layer 38 * depending on the configuration variable 'protocol'. This should be set 39 * to 0 (default) for TCP or 1 for SCTP. It should be configured using a 40 * cluster-wide mechanism as it must be the same on all nodes of the cluster 41 * for the DLM to function. 42 * 43 */ 44 45 #include <asm/ioctls.h> 46 #include <net/sock.h> 47 #include <net/tcp.h> 48 #include <linux/pagemap.h> 49 #include <linux/file.h> 50 #include <linux/mutex.h> 51 #include <linux/sctp.h> 52 #include <linux/slab.h> 53 #include <net/sctp/sctp.h> 54 #include <net/ipv6.h> 55 56 #include <trace/events/dlm.h> 57 58 #include "dlm_internal.h" 59 #include "lowcomms.h" 60 #include "midcomms.h" 61 #include "memory.h" 62 #include "config.h" 63 64 #define NEEDED_RMEM (4*1024*1024) 65 66 /* Number of messages to send before rescheduling */ 67 #define MAX_SEND_MSG_COUNT 25 68 #define DLM_SHUTDOWN_WAIT_TIMEOUT msecs_to_jiffies(10000) 69 70 struct connection { 71 struct socket *sock; /* NULL if not connected */ 72 uint32_t nodeid; /* So we know who we are in the list */ 73 struct mutex sock_mutex; 74 unsigned long flags; 75 #define CF_READ_PENDING 1 76 #define CF_WRITE_PENDING 2 77 #define CF_INIT_PENDING 4 78 #define CF_IS_OTHERCON 5 79 #define CF_CLOSE 6 80 #define CF_APP_LIMITED 7 81 #define CF_CLOSING 8 82 #define CF_SHUTDOWN 9 83 #define CF_CONNECTED 10 84 #define CF_RECONNECT 11 85 #define CF_DELAY_CONNECT 12 86 #define CF_EOF 13 87 struct list_head writequeue; /* List of outgoing writequeue_entries */ 88 spinlock_t writequeue_lock; 89 atomic_t writequeue_cnt; 90 int retries; 91 #define MAX_CONNECT_RETRIES 3 92 struct hlist_node list; 93 struct connection *othercon; 94 struct connection *sendcon; 95 struct work_struct rwork; /* Receive workqueue */ 96 struct work_struct swork; /* Send workqueue */ 97 wait_queue_head_t shutdown_wait; /* wait for graceful shutdown */ 98 unsigned char *rx_buf; 99 int rx_buflen; 100 int rx_leftover; 101 struct rcu_head rcu; 102 }; 103 #define sock2con(x) ((struct connection *)(x)->sk_user_data) 104 105 struct listen_connection { 106 struct socket *sock; 107 struct work_struct rwork; 108 }; 109 110 #define DLM_WQ_REMAIN_BYTES(e) (PAGE_SIZE - e->end) 111 #define DLM_WQ_LENGTH_BYTES(e) (e->end - e->offset) 112 113 /* An entry waiting to be sent */ 114 struct writequeue_entry { 115 struct list_head list; 116 struct page *page; 117 int offset; 118 int len; 119 int end; 120 int users; 121 bool dirty; 122 struct connection *con; 123 struct list_head msgs; 124 struct kref ref; 125 }; 126 127 struct dlm_msg { 128 struct writequeue_entry *entry; 129 struct dlm_msg *orig_msg; 130 bool retransmit; 131 void *ppc; 132 int len; 133 int idx; /* new()/commit() idx exchange */ 134 135 struct list_head list; 136 struct kref ref; 137 }; 138 139 struct dlm_node_addr { 140 struct list_head list; 141 int nodeid; 142 int mark; 143 int addr_count; 144 int curr_addr_index; 145 struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT]; 146 }; 147 148 struct dlm_proto_ops { 149 bool try_new_addr; 150 const char *name; 151 int proto; 152 153 int (*connect)(struct connection *con, struct socket *sock, 154 struct sockaddr *addr, int addr_len); 155 void (*sockopts)(struct socket *sock); 156 int (*bind)(struct socket *sock); 157 int (*listen_validate)(void); 158 void (*listen_sockopts)(struct socket *sock); 159 int (*listen_bind)(struct socket *sock); 160 /* What to do to shutdown */ 161 void (*shutdown_action)(struct connection *con); 162 /* What to do to eof check */ 163 bool (*eof_condition)(struct connection *con); 164 }; 165 166 static struct listen_sock_callbacks { 167 void (*sk_error_report)(struct sock *); 168 void (*sk_data_ready)(struct sock *); 169 void (*sk_state_change)(struct sock *); 170 void (*sk_write_space)(struct sock *); 171 } listen_sock; 172 173 static LIST_HEAD(dlm_node_addrs); 174 static DEFINE_SPINLOCK(dlm_node_addrs_spin); 175 176 static struct listen_connection listen_con; 177 static struct sockaddr_storage *dlm_local_addr[DLM_MAX_ADDR_COUNT]; 178 static int dlm_local_count; 179 int dlm_allow_conn; 180 181 /* Work queues */ 182 static struct workqueue_struct *recv_workqueue; 183 static struct workqueue_struct *send_workqueue; 184 185 static struct hlist_head connection_hash[CONN_HASH_SIZE]; 186 static DEFINE_SPINLOCK(connections_lock); 187 DEFINE_STATIC_SRCU(connections_srcu); 188 189 static const struct dlm_proto_ops *dlm_proto_ops; 190 191 static void process_recv_sockets(struct work_struct *work); 192 static void process_send_sockets(struct work_struct *work); 193 194 static void writequeue_entry_ctor(void *data) 195 { 196 struct writequeue_entry *entry = data; 197 198 INIT_LIST_HEAD(&entry->msgs); 199 } 200 201 struct kmem_cache *dlm_lowcomms_writequeue_cache_create(void) 202 { 203 return kmem_cache_create("dlm_writequeue", sizeof(struct writequeue_entry), 204 0, 0, writequeue_entry_ctor); 205 } 206 207 struct kmem_cache *dlm_lowcomms_msg_cache_create(void) 208 { 209 return kmem_cache_create("dlm_msg", sizeof(struct dlm_msg), 0, 0, NULL); 210 } 211 212 /* need to held writequeue_lock */ 213 static struct writequeue_entry *con_next_wq(struct connection *con) 214 { 215 struct writequeue_entry *e; 216 217 if (list_empty(&con->writequeue)) 218 return NULL; 219 220 e = list_first_entry(&con->writequeue, struct writequeue_entry, 221 list); 222 /* if len is zero nothing is to send, if there are users filling 223 * buffers we wait until the users are done so we can send more. 224 */ 225 if (e->users || e->len == 0) 226 return NULL; 227 228 return e; 229 } 230 231 static struct connection *__find_con(int nodeid, int r) 232 { 233 struct connection *con; 234 235 hlist_for_each_entry_rcu(con, &connection_hash[r], list) { 236 if (con->nodeid == nodeid) 237 return con; 238 } 239 240 return NULL; 241 } 242 243 static bool tcp_eof_condition(struct connection *con) 244 { 245 return atomic_read(&con->writequeue_cnt); 246 } 247 248 static int dlm_con_init(struct connection *con, int nodeid) 249 { 250 con->rx_buflen = dlm_config.ci_buffer_size; 251 con->rx_buf = kmalloc(con->rx_buflen, GFP_NOFS); 252 if (!con->rx_buf) 253 return -ENOMEM; 254 255 con->nodeid = nodeid; 256 mutex_init(&con->sock_mutex); 257 INIT_LIST_HEAD(&con->writequeue); 258 spin_lock_init(&con->writequeue_lock); 259 atomic_set(&con->writequeue_cnt, 0); 260 INIT_WORK(&con->swork, process_send_sockets); 261 INIT_WORK(&con->rwork, process_recv_sockets); 262 init_waitqueue_head(&con->shutdown_wait); 263 264 return 0; 265 } 266 267 /* 268 * If 'allocation' is zero then we don't attempt to create a new 269 * connection structure for this node. 270 */ 271 static struct connection *nodeid2con(int nodeid, gfp_t alloc) 272 { 273 struct connection *con, *tmp; 274 int r, ret; 275 276 r = nodeid_hash(nodeid); 277 con = __find_con(nodeid, r); 278 if (con || !alloc) 279 return con; 280 281 con = kzalloc(sizeof(*con), alloc); 282 if (!con) 283 return NULL; 284 285 ret = dlm_con_init(con, nodeid); 286 if (ret) { 287 kfree(con); 288 return NULL; 289 } 290 291 spin_lock(&connections_lock); 292 /* Because multiple workqueues/threads calls this function it can 293 * race on multiple cpu's. Instead of locking hot path __find_con() 294 * we just check in rare cases of recently added nodes again 295 * under protection of connections_lock. If this is the case we 296 * abort our connection creation and return the existing connection. 297 */ 298 tmp = __find_con(nodeid, r); 299 if (tmp) { 300 spin_unlock(&connections_lock); 301 kfree(con->rx_buf); 302 kfree(con); 303 return tmp; 304 } 305 306 hlist_add_head_rcu(&con->list, &connection_hash[r]); 307 spin_unlock(&connections_lock); 308 309 return con; 310 } 311 312 /* Loop round all connections */ 313 static void foreach_conn(void (*conn_func)(struct connection *c)) 314 { 315 int i; 316 struct connection *con; 317 318 for (i = 0; i < CONN_HASH_SIZE; i++) { 319 hlist_for_each_entry_rcu(con, &connection_hash[i], list) 320 conn_func(con); 321 } 322 } 323 324 static struct dlm_node_addr *find_node_addr(int nodeid) 325 { 326 struct dlm_node_addr *na; 327 328 list_for_each_entry(na, &dlm_node_addrs, list) { 329 if (na->nodeid == nodeid) 330 return na; 331 } 332 return NULL; 333 } 334 335 static int addr_compare(const struct sockaddr_storage *x, 336 const struct sockaddr_storage *y) 337 { 338 switch (x->ss_family) { 339 case AF_INET: { 340 struct sockaddr_in *sinx = (struct sockaddr_in *)x; 341 struct sockaddr_in *siny = (struct sockaddr_in *)y; 342 if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr) 343 return 0; 344 if (sinx->sin_port != siny->sin_port) 345 return 0; 346 break; 347 } 348 case AF_INET6: { 349 struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x; 350 struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y; 351 if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr)) 352 return 0; 353 if (sinx->sin6_port != siny->sin6_port) 354 return 0; 355 break; 356 } 357 default: 358 return 0; 359 } 360 return 1; 361 } 362 363 static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out, 364 struct sockaddr *sa_out, bool try_new_addr, 365 unsigned int *mark) 366 { 367 struct sockaddr_storage sas; 368 struct dlm_node_addr *na; 369 370 if (!dlm_local_count) 371 return -1; 372 373 spin_lock(&dlm_node_addrs_spin); 374 na = find_node_addr(nodeid); 375 if (na && na->addr_count) { 376 memcpy(&sas, na->addr[na->curr_addr_index], 377 sizeof(struct sockaddr_storage)); 378 379 if (try_new_addr) { 380 na->curr_addr_index++; 381 if (na->curr_addr_index == na->addr_count) 382 na->curr_addr_index = 0; 383 } 384 } 385 spin_unlock(&dlm_node_addrs_spin); 386 387 if (!na) 388 return -EEXIST; 389 390 if (!na->addr_count) 391 return -ENOENT; 392 393 *mark = na->mark; 394 395 if (sas_out) 396 memcpy(sas_out, &sas, sizeof(struct sockaddr_storage)); 397 398 if (!sa_out) 399 return 0; 400 401 if (dlm_local_addr[0]->ss_family == AF_INET) { 402 struct sockaddr_in *in4 = (struct sockaddr_in *) &sas; 403 struct sockaddr_in *ret4 = (struct sockaddr_in *) sa_out; 404 ret4->sin_addr.s_addr = in4->sin_addr.s_addr; 405 } else { 406 struct sockaddr_in6 *in6 = (struct sockaddr_in6 *) &sas; 407 struct sockaddr_in6 *ret6 = (struct sockaddr_in6 *) sa_out; 408 ret6->sin6_addr = in6->sin6_addr; 409 } 410 411 return 0; 412 } 413 414 static int addr_to_nodeid(struct sockaddr_storage *addr, int *nodeid, 415 unsigned int *mark) 416 { 417 struct dlm_node_addr *na; 418 int rv = -EEXIST; 419 int addr_i; 420 421 spin_lock(&dlm_node_addrs_spin); 422 list_for_each_entry(na, &dlm_node_addrs, list) { 423 if (!na->addr_count) 424 continue; 425 426 for (addr_i = 0; addr_i < na->addr_count; addr_i++) { 427 if (addr_compare(na->addr[addr_i], addr)) { 428 *nodeid = na->nodeid; 429 *mark = na->mark; 430 rv = 0; 431 goto unlock; 432 } 433 } 434 } 435 unlock: 436 spin_unlock(&dlm_node_addrs_spin); 437 return rv; 438 } 439 440 /* caller need to held dlm_node_addrs_spin lock */ 441 static bool dlm_lowcomms_na_has_addr(const struct dlm_node_addr *na, 442 const struct sockaddr_storage *addr) 443 { 444 int i; 445 446 for (i = 0; i < na->addr_count; i++) { 447 if (addr_compare(na->addr[i], addr)) 448 return true; 449 } 450 451 return false; 452 } 453 454 int dlm_lowcomms_addr(int nodeid, struct sockaddr_storage *addr, int len) 455 { 456 struct sockaddr_storage *new_addr; 457 struct dlm_node_addr *new_node, *na; 458 bool ret; 459 460 new_node = kzalloc(sizeof(struct dlm_node_addr), GFP_NOFS); 461 if (!new_node) 462 return -ENOMEM; 463 464 new_addr = kzalloc(sizeof(struct sockaddr_storage), GFP_NOFS); 465 if (!new_addr) { 466 kfree(new_node); 467 return -ENOMEM; 468 } 469 470 memcpy(new_addr, addr, len); 471 472 spin_lock(&dlm_node_addrs_spin); 473 na = find_node_addr(nodeid); 474 if (!na) { 475 new_node->nodeid = nodeid; 476 new_node->addr[0] = new_addr; 477 new_node->addr_count = 1; 478 new_node->mark = dlm_config.ci_mark; 479 list_add(&new_node->list, &dlm_node_addrs); 480 spin_unlock(&dlm_node_addrs_spin); 481 return 0; 482 } 483 484 ret = dlm_lowcomms_na_has_addr(na, addr); 485 if (ret) { 486 spin_unlock(&dlm_node_addrs_spin); 487 kfree(new_addr); 488 kfree(new_node); 489 return -EEXIST; 490 } 491 492 if (na->addr_count >= DLM_MAX_ADDR_COUNT) { 493 spin_unlock(&dlm_node_addrs_spin); 494 kfree(new_addr); 495 kfree(new_node); 496 return -ENOSPC; 497 } 498 499 na->addr[na->addr_count++] = new_addr; 500 spin_unlock(&dlm_node_addrs_spin); 501 kfree(new_node); 502 return 0; 503 } 504 505 /* Data available on socket or listen socket received a connect */ 506 static void lowcomms_data_ready(struct sock *sk) 507 { 508 struct connection *con; 509 510 con = sock2con(sk); 511 if (con && !test_and_set_bit(CF_READ_PENDING, &con->flags)) 512 queue_work(recv_workqueue, &con->rwork); 513 } 514 515 static void lowcomms_listen_data_ready(struct sock *sk) 516 { 517 if (!dlm_allow_conn) 518 return; 519 520 queue_work(recv_workqueue, &listen_con.rwork); 521 } 522 523 static void lowcomms_write_space(struct sock *sk) 524 { 525 struct connection *con; 526 527 con = sock2con(sk); 528 if (!con) 529 return; 530 531 if (!test_and_set_bit(CF_CONNECTED, &con->flags)) { 532 log_print("successful connected to node %d", con->nodeid); 533 queue_work(send_workqueue, &con->swork); 534 return; 535 } 536 537 clear_bit(SOCK_NOSPACE, &con->sock->flags); 538 539 if (test_and_clear_bit(CF_APP_LIMITED, &con->flags)) { 540 con->sock->sk->sk_write_pending--; 541 clear_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags); 542 } 543 544 queue_work(send_workqueue, &con->swork); 545 } 546 547 static inline void lowcomms_connect_sock(struct connection *con) 548 { 549 if (test_bit(CF_CLOSE, &con->flags)) 550 return; 551 queue_work(send_workqueue, &con->swork); 552 cond_resched(); 553 } 554 555 static void lowcomms_state_change(struct sock *sk) 556 { 557 /* SCTP layer is not calling sk_data_ready when the connection 558 * is done, so we catch the signal through here. Also, it 559 * doesn't switch socket state when entering shutdown, so we 560 * skip the write in that case. 561 */ 562 if (sk->sk_shutdown) { 563 if (sk->sk_shutdown == RCV_SHUTDOWN) 564 lowcomms_data_ready(sk); 565 } else if (sk->sk_state == TCP_ESTABLISHED) { 566 lowcomms_write_space(sk); 567 } 568 } 569 570 int dlm_lowcomms_connect_node(int nodeid) 571 { 572 struct connection *con; 573 int idx; 574 575 if (nodeid == dlm_our_nodeid()) 576 return 0; 577 578 idx = srcu_read_lock(&connections_srcu); 579 con = nodeid2con(nodeid, GFP_NOFS); 580 if (!con) { 581 srcu_read_unlock(&connections_srcu, idx); 582 return -ENOMEM; 583 } 584 585 lowcomms_connect_sock(con); 586 srcu_read_unlock(&connections_srcu, idx); 587 588 return 0; 589 } 590 591 int dlm_lowcomms_nodes_set_mark(int nodeid, unsigned int mark) 592 { 593 struct dlm_node_addr *na; 594 595 spin_lock(&dlm_node_addrs_spin); 596 na = find_node_addr(nodeid); 597 if (!na) { 598 spin_unlock(&dlm_node_addrs_spin); 599 return -ENOENT; 600 } 601 602 na->mark = mark; 603 spin_unlock(&dlm_node_addrs_spin); 604 605 return 0; 606 } 607 608 static void lowcomms_error_report(struct sock *sk) 609 { 610 struct connection *con; 611 void (*orig_report)(struct sock *) = NULL; 612 struct inet_sock *inet; 613 614 con = sock2con(sk); 615 if (con == NULL) 616 goto out; 617 618 orig_report = listen_sock.sk_error_report; 619 620 inet = inet_sk(sk); 621 switch (sk->sk_family) { 622 case AF_INET: 623 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 624 "sending to node %d at %pI4, dport %d, " 625 "sk_err=%d/%d\n", dlm_our_nodeid(), 626 con->nodeid, &inet->inet_daddr, 627 ntohs(inet->inet_dport), sk->sk_err, 628 sk->sk_err_soft); 629 break; 630 #if IS_ENABLED(CONFIG_IPV6) 631 case AF_INET6: 632 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 633 "sending to node %d at %pI6c, " 634 "dport %d, sk_err=%d/%d\n", dlm_our_nodeid(), 635 con->nodeid, &sk->sk_v6_daddr, 636 ntohs(inet->inet_dport), sk->sk_err, 637 sk->sk_err_soft); 638 break; 639 #endif 640 default: 641 printk_ratelimited(KERN_ERR "dlm: node %d: socket error " 642 "invalid socket family %d set, " 643 "sk_err=%d/%d\n", dlm_our_nodeid(), 644 sk->sk_family, sk->sk_err, sk->sk_err_soft); 645 goto out; 646 } 647 648 /* below sendcon only handling */ 649 if (test_bit(CF_IS_OTHERCON, &con->flags)) 650 con = con->sendcon; 651 652 switch (sk->sk_err) { 653 case ECONNREFUSED: 654 set_bit(CF_DELAY_CONNECT, &con->flags); 655 break; 656 default: 657 break; 658 } 659 660 if (!test_and_set_bit(CF_RECONNECT, &con->flags)) 661 queue_work(send_workqueue, &con->swork); 662 663 out: 664 if (orig_report) 665 orig_report(sk); 666 } 667 668 /* Note: sk_callback_lock must be locked before calling this function. */ 669 static void save_listen_callbacks(struct socket *sock) 670 { 671 struct sock *sk = sock->sk; 672 673 listen_sock.sk_data_ready = sk->sk_data_ready; 674 listen_sock.sk_state_change = sk->sk_state_change; 675 listen_sock.sk_write_space = sk->sk_write_space; 676 listen_sock.sk_error_report = sk->sk_error_report; 677 } 678 679 static void restore_callbacks(struct socket *sock) 680 { 681 struct sock *sk = sock->sk; 682 683 lock_sock(sk); 684 sk->sk_user_data = NULL; 685 sk->sk_data_ready = listen_sock.sk_data_ready; 686 sk->sk_state_change = listen_sock.sk_state_change; 687 sk->sk_write_space = listen_sock.sk_write_space; 688 sk->sk_error_report = listen_sock.sk_error_report; 689 release_sock(sk); 690 } 691 692 static void add_listen_sock(struct socket *sock, struct listen_connection *con) 693 { 694 struct sock *sk = sock->sk; 695 696 lock_sock(sk); 697 save_listen_callbacks(sock); 698 con->sock = sock; 699 700 sk->sk_user_data = con; 701 sk->sk_allocation = GFP_NOFS; 702 /* Install a data_ready callback */ 703 sk->sk_data_ready = lowcomms_listen_data_ready; 704 release_sock(sk); 705 } 706 707 /* Make a socket active */ 708 static void add_sock(struct socket *sock, struct connection *con) 709 { 710 struct sock *sk = sock->sk; 711 712 lock_sock(sk); 713 con->sock = sock; 714 715 sk->sk_user_data = con; 716 /* Install a data_ready callback */ 717 sk->sk_data_ready = lowcomms_data_ready; 718 sk->sk_write_space = lowcomms_write_space; 719 sk->sk_state_change = lowcomms_state_change; 720 sk->sk_allocation = GFP_NOFS; 721 sk->sk_error_report = lowcomms_error_report; 722 release_sock(sk); 723 } 724 725 /* Add the port number to an IPv6 or 4 sockaddr and return the address 726 length */ 727 static void make_sockaddr(struct sockaddr_storage *saddr, uint16_t port, 728 int *addr_len) 729 { 730 saddr->ss_family = dlm_local_addr[0]->ss_family; 731 if (saddr->ss_family == AF_INET) { 732 struct sockaddr_in *in4_addr = (struct sockaddr_in *)saddr; 733 in4_addr->sin_port = cpu_to_be16(port); 734 *addr_len = sizeof(struct sockaddr_in); 735 memset(&in4_addr->sin_zero, 0, sizeof(in4_addr->sin_zero)); 736 } else { 737 struct sockaddr_in6 *in6_addr = (struct sockaddr_in6 *)saddr; 738 in6_addr->sin6_port = cpu_to_be16(port); 739 *addr_len = sizeof(struct sockaddr_in6); 740 } 741 memset((char *)saddr + *addr_len, 0, sizeof(struct sockaddr_storage) - *addr_len); 742 } 743 744 static void dlm_page_release(struct kref *kref) 745 { 746 struct writequeue_entry *e = container_of(kref, struct writequeue_entry, 747 ref); 748 749 __free_page(e->page); 750 dlm_free_writequeue(e); 751 } 752 753 static void dlm_msg_release(struct kref *kref) 754 { 755 struct dlm_msg *msg = container_of(kref, struct dlm_msg, ref); 756 757 kref_put(&msg->entry->ref, dlm_page_release); 758 dlm_free_msg(msg); 759 } 760 761 static void free_entry(struct writequeue_entry *e) 762 { 763 struct dlm_msg *msg, *tmp; 764 765 list_for_each_entry_safe(msg, tmp, &e->msgs, list) { 766 if (msg->orig_msg) { 767 msg->orig_msg->retransmit = false; 768 kref_put(&msg->orig_msg->ref, dlm_msg_release); 769 } 770 771 list_del(&msg->list); 772 kref_put(&msg->ref, dlm_msg_release); 773 } 774 775 list_del(&e->list); 776 atomic_dec(&e->con->writequeue_cnt); 777 kref_put(&e->ref, dlm_page_release); 778 } 779 780 static void dlm_close_sock(struct socket **sock) 781 { 782 if (*sock) { 783 restore_callbacks(*sock); 784 sock_release(*sock); 785 *sock = NULL; 786 } 787 } 788 789 /* Close a remote connection and tidy up */ 790 static void close_connection(struct connection *con, bool and_other, 791 bool tx, bool rx) 792 { 793 bool closing = test_and_set_bit(CF_CLOSING, &con->flags); 794 struct writequeue_entry *e; 795 796 if (tx && !closing && cancel_work_sync(&con->swork)) { 797 log_print("canceled swork for node %d", con->nodeid); 798 clear_bit(CF_WRITE_PENDING, &con->flags); 799 } 800 if (rx && !closing && cancel_work_sync(&con->rwork)) { 801 log_print("canceled rwork for node %d", con->nodeid); 802 clear_bit(CF_READ_PENDING, &con->flags); 803 } 804 805 mutex_lock(&con->sock_mutex); 806 dlm_close_sock(&con->sock); 807 808 if (con->othercon && and_other) { 809 /* Will only re-enter once. */ 810 close_connection(con->othercon, false, tx, rx); 811 } 812 813 /* if we send a writequeue entry only a half way, we drop the 814 * whole entry because reconnection and that we not start of the 815 * middle of a msg which will confuse the other end. 816 * 817 * we can always drop messages because retransmits, but what we 818 * cannot allow is to transmit half messages which may be processed 819 * at the other side. 820 * 821 * our policy is to start on a clean state when disconnects, we don't 822 * know what's send/received on transport layer in this case. 823 */ 824 spin_lock(&con->writequeue_lock); 825 if (!list_empty(&con->writequeue)) { 826 e = list_first_entry(&con->writequeue, struct writequeue_entry, 827 list); 828 if (e->dirty) 829 free_entry(e); 830 } 831 spin_unlock(&con->writequeue_lock); 832 833 con->rx_leftover = 0; 834 con->retries = 0; 835 clear_bit(CF_APP_LIMITED, &con->flags); 836 clear_bit(CF_CONNECTED, &con->flags); 837 clear_bit(CF_DELAY_CONNECT, &con->flags); 838 clear_bit(CF_RECONNECT, &con->flags); 839 clear_bit(CF_EOF, &con->flags); 840 mutex_unlock(&con->sock_mutex); 841 clear_bit(CF_CLOSING, &con->flags); 842 } 843 844 static void shutdown_connection(struct connection *con) 845 { 846 int ret; 847 848 flush_work(&con->swork); 849 850 mutex_lock(&con->sock_mutex); 851 /* nothing to shutdown */ 852 if (!con->sock) { 853 mutex_unlock(&con->sock_mutex); 854 return; 855 } 856 857 set_bit(CF_SHUTDOWN, &con->flags); 858 ret = kernel_sock_shutdown(con->sock, SHUT_WR); 859 mutex_unlock(&con->sock_mutex); 860 if (ret) { 861 log_print("Connection %p failed to shutdown: %d will force close", 862 con, ret); 863 goto force_close; 864 } else { 865 ret = wait_event_timeout(con->shutdown_wait, 866 !test_bit(CF_SHUTDOWN, &con->flags), 867 DLM_SHUTDOWN_WAIT_TIMEOUT); 868 if (ret == 0) { 869 log_print("Connection %p shutdown timed out, will force close", 870 con); 871 goto force_close; 872 } 873 } 874 875 return; 876 877 force_close: 878 clear_bit(CF_SHUTDOWN, &con->flags); 879 close_connection(con, false, true, true); 880 } 881 882 static void dlm_tcp_shutdown(struct connection *con) 883 { 884 if (con->othercon) 885 shutdown_connection(con->othercon); 886 shutdown_connection(con); 887 } 888 889 static int con_realloc_receive_buf(struct connection *con, int newlen) 890 { 891 unsigned char *newbuf; 892 893 newbuf = kmalloc(newlen, GFP_NOFS); 894 if (!newbuf) 895 return -ENOMEM; 896 897 /* copy any leftover from last receive */ 898 if (con->rx_leftover) 899 memmove(newbuf, con->rx_buf, con->rx_leftover); 900 901 /* swap to new buffer space */ 902 kfree(con->rx_buf); 903 con->rx_buflen = newlen; 904 con->rx_buf = newbuf; 905 906 return 0; 907 } 908 909 /* Data received from remote end */ 910 static int receive_from_sock(struct connection *con) 911 { 912 struct msghdr msg; 913 struct kvec iov; 914 int ret, buflen; 915 916 mutex_lock(&con->sock_mutex); 917 918 if (con->sock == NULL) { 919 ret = -EAGAIN; 920 goto out_close; 921 } 922 923 /* realloc if we get new buffer size to read out */ 924 buflen = dlm_config.ci_buffer_size; 925 if (con->rx_buflen != buflen && con->rx_leftover <= buflen) { 926 ret = con_realloc_receive_buf(con, buflen); 927 if (ret < 0) 928 goto out_resched; 929 } 930 931 for (;;) { 932 /* calculate new buffer parameter regarding last receive and 933 * possible leftover bytes 934 */ 935 iov.iov_base = con->rx_buf + con->rx_leftover; 936 iov.iov_len = con->rx_buflen - con->rx_leftover; 937 938 memset(&msg, 0, sizeof(msg)); 939 msg.msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 940 ret = kernel_recvmsg(con->sock, &msg, &iov, 1, iov.iov_len, 941 msg.msg_flags); 942 trace_dlm_recv(con->nodeid, ret); 943 if (ret == -EAGAIN) 944 break; 945 else if (ret <= 0) 946 goto out_close; 947 948 /* new buflen according readed bytes and leftover from last receive */ 949 buflen = ret + con->rx_leftover; 950 ret = dlm_process_incoming_buffer(con->nodeid, con->rx_buf, buflen); 951 if (ret < 0) 952 goto out_close; 953 954 /* calculate leftover bytes from process and put it into begin of 955 * the receive buffer, so next receive we have the full message 956 * at the start address of the receive buffer. 957 */ 958 con->rx_leftover = buflen - ret; 959 if (con->rx_leftover) { 960 memmove(con->rx_buf, con->rx_buf + ret, 961 con->rx_leftover); 962 } 963 } 964 965 dlm_midcomms_receive_done(con->nodeid); 966 mutex_unlock(&con->sock_mutex); 967 return 0; 968 969 out_resched: 970 if (!test_and_set_bit(CF_READ_PENDING, &con->flags)) 971 queue_work(recv_workqueue, &con->rwork); 972 mutex_unlock(&con->sock_mutex); 973 return -EAGAIN; 974 975 out_close: 976 if (ret == 0) { 977 log_print("connection %p got EOF from %d", 978 con, con->nodeid); 979 980 if (dlm_proto_ops->eof_condition && 981 dlm_proto_ops->eof_condition(con)) { 982 set_bit(CF_EOF, &con->flags); 983 mutex_unlock(&con->sock_mutex); 984 } else { 985 mutex_unlock(&con->sock_mutex); 986 close_connection(con, false, true, false); 987 988 /* handling for tcp shutdown */ 989 clear_bit(CF_SHUTDOWN, &con->flags); 990 wake_up(&con->shutdown_wait); 991 } 992 993 /* signal to breaking receive worker */ 994 ret = -1; 995 } else { 996 mutex_unlock(&con->sock_mutex); 997 } 998 return ret; 999 } 1000 1001 /* Listening socket is busy, accept a connection */ 1002 static int accept_from_sock(struct listen_connection *con) 1003 { 1004 int result; 1005 struct sockaddr_storage peeraddr; 1006 struct socket *newsock; 1007 int len, idx; 1008 int nodeid; 1009 struct connection *newcon; 1010 struct connection *addcon; 1011 unsigned int mark; 1012 1013 if (!con->sock) 1014 return -ENOTCONN; 1015 1016 result = kernel_accept(con->sock, &newsock, O_NONBLOCK); 1017 if (result < 0) 1018 goto accept_err; 1019 1020 /* Get the connected socket's peer */ 1021 memset(&peeraddr, 0, sizeof(peeraddr)); 1022 len = newsock->ops->getname(newsock, (struct sockaddr *)&peeraddr, 2); 1023 if (len < 0) { 1024 result = -ECONNABORTED; 1025 goto accept_err; 1026 } 1027 1028 /* Get the new node's NODEID */ 1029 make_sockaddr(&peeraddr, 0, &len); 1030 if (addr_to_nodeid(&peeraddr, &nodeid, &mark)) { 1031 switch (peeraddr.ss_family) { 1032 case AF_INET: { 1033 struct sockaddr_in *sin = (struct sockaddr_in *)&peeraddr; 1034 1035 log_print("connect from non cluster IPv4 node %pI4", 1036 &sin->sin_addr); 1037 break; 1038 } 1039 #if IS_ENABLED(CONFIG_IPV6) 1040 case AF_INET6: { 1041 struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)&peeraddr; 1042 1043 log_print("connect from non cluster IPv6 node %pI6c", 1044 &sin6->sin6_addr); 1045 break; 1046 } 1047 #endif 1048 default: 1049 log_print("invalid family from non cluster node"); 1050 break; 1051 } 1052 1053 sock_release(newsock); 1054 return -1; 1055 } 1056 1057 log_print("got connection from %d", nodeid); 1058 1059 /* Check to see if we already have a connection to this node. This 1060 * could happen if the two nodes initiate a connection at roughly 1061 * the same time and the connections cross on the wire. 1062 * In this case we store the incoming one in "othercon" 1063 */ 1064 idx = srcu_read_lock(&connections_srcu); 1065 newcon = nodeid2con(nodeid, GFP_NOFS); 1066 if (!newcon) { 1067 srcu_read_unlock(&connections_srcu, idx); 1068 result = -ENOMEM; 1069 goto accept_err; 1070 } 1071 1072 sock_set_mark(newsock->sk, mark); 1073 1074 mutex_lock(&newcon->sock_mutex); 1075 if (newcon->sock) { 1076 struct connection *othercon = newcon->othercon; 1077 1078 if (!othercon) { 1079 othercon = kzalloc(sizeof(*othercon), GFP_NOFS); 1080 if (!othercon) { 1081 log_print("failed to allocate incoming socket"); 1082 mutex_unlock(&newcon->sock_mutex); 1083 srcu_read_unlock(&connections_srcu, idx); 1084 result = -ENOMEM; 1085 goto accept_err; 1086 } 1087 1088 result = dlm_con_init(othercon, nodeid); 1089 if (result < 0) { 1090 kfree(othercon); 1091 mutex_unlock(&newcon->sock_mutex); 1092 srcu_read_unlock(&connections_srcu, idx); 1093 goto accept_err; 1094 } 1095 1096 lockdep_set_subclass(&othercon->sock_mutex, 1); 1097 set_bit(CF_IS_OTHERCON, &othercon->flags); 1098 newcon->othercon = othercon; 1099 othercon->sendcon = newcon; 1100 } else { 1101 /* close other sock con if we have something new */ 1102 close_connection(othercon, false, true, false); 1103 } 1104 1105 mutex_lock(&othercon->sock_mutex); 1106 add_sock(newsock, othercon); 1107 addcon = othercon; 1108 mutex_unlock(&othercon->sock_mutex); 1109 } 1110 else { 1111 /* accept copies the sk after we've saved the callbacks, so we 1112 don't want to save them a second time or comm errors will 1113 result in calling sk_error_report recursively. */ 1114 add_sock(newsock, newcon); 1115 addcon = newcon; 1116 } 1117 1118 set_bit(CF_CONNECTED, &addcon->flags); 1119 mutex_unlock(&newcon->sock_mutex); 1120 1121 /* 1122 * Add it to the active queue in case we got data 1123 * between processing the accept adding the socket 1124 * to the read_sockets list 1125 */ 1126 if (!test_and_set_bit(CF_READ_PENDING, &addcon->flags)) 1127 queue_work(recv_workqueue, &addcon->rwork); 1128 1129 srcu_read_unlock(&connections_srcu, idx); 1130 1131 return 0; 1132 1133 accept_err: 1134 if (newsock) 1135 sock_release(newsock); 1136 1137 if (result != -EAGAIN) 1138 log_print("error accepting connection from node: %d", result); 1139 return result; 1140 } 1141 1142 /* 1143 * writequeue_entry_complete - try to delete and free write queue entry 1144 * @e: write queue entry to try to delete 1145 * @completed: bytes completed 1146 * 1147 * writequeue_lock must be held. 1148 */ 1149 static void writequeue_entry_complete(struct writequeue_entry *e, int completed) 1150 { 1151 e->offset += completed; 1152 e->len -= completed; 1153 /* signal that page was half way transmitted */ 1154 e->dirty = true; 1155 1156 if (e->len == 0 && e->users == 0) 1157 free_entry(e); 1158 } 1159 1160 /* 1161 * sctp_bind_addrs - bind a SCTP socket to all our addresses 1162 */ 1163 static int sctp_bind_addrs(struct socket *sock, uint16_t port) 1164 { 1165 struct sockaddr_storage localaddr; 1166 struct sockaddr *addr = (struct sockaddr *)&localaddr; 1167 int i, addr_len, result = 0; 1168 1169 for (i = 0; i < dlm_local_count; i++) { 1170 memcpy(&localaddr, dlm_local_addr[i], sizeof(localaddr)); 1171 make_sockaddr(&localaddr, port, &addr_len); 1172 1173 if (!i) 1174 result = kernel_bind(sock, addr, addr_len); 1175 else 1176 result = sock_bind_add(sock->sk, addr, addr_len); 1177 1178 if (result < 0) { 1179 log_print("Can't bind to %d addr number %d, %d.\n", 1180 port, i + 1, result); 1181 break; 1182 } 1183 } 1184 return result; 1185 } 1186 1187 /* Get local addresses */ 1188 static void init_local(void) 1189 { 1190 struct sockaddr_storage sas, *addr; 1191 int i; 1192 1193 dlm_local_count = 0; 1194 for (i = 0; i < DLM_MAX_ADDR_COUNT; i++) { 1195 if (dlm_our_addr(&sas, i)) 1196 break; 1197 1198 addr = kmemdup(&sas, sizeof(*addr), GFP_NOFS); 1199 if (!addr) 1200 break; 1201 dlm_local_addr[dlm_local_count++] = addr; 1202 } 1203 } 1204 1205 static void deinit_local(void) 1206 { 1207 int i; 1208 1209 for (i = 0; i < dlm_local_count; i++) 1210 kfree(dlm_local_addr[i]); 1211 } 1212 1213 static struct writequeue_entry *new_writequeue_entry(struct connection *con) 1214 { 1215 struct writequeue_entry *entry; 1216 1217 entry = dlm_allocate_writequeue(); 1218 if (!entry) 1219 return NULL; 1220 1221 entry->page = alloc_page(GFP_ATOMIC | __GFP_ZERO); 1222 if (!entry->page) { 1223 dlm_free_writequeue(entry); 1224 return NULL; 1225 } 1226 1227 entry->offset = 0; 1228 entry->len = 0; 1229 entry->end = 0; 1230 entry->dirty = false; 1231 entry->con = con; 1232 entry->users = 1; 1233 kref_init(&entry->ref); 1234 return entry; 1235 } 1236 1237 static struct writequeue_entry *new_wq_entry(struct connection *con, int len, 1238 char **ppc, void (*cb)(void *data), 1239 void *data) 1240 { 1241 struct writequeue_entry *e; 1242 1243 spin_lock(&con->writequeue_lock); 1244 if (!list_empty(&con->writequeue)) { 1245 e = list_last_entry(&con->writequeue, struct writequeue_entry, list); 1246 if (DLM_WQ_REMAIN_BYTES(e) >= len) { 1247 kref_get(&e->ref); 1248 1249 *ppc = page_address(e->page) + e->end; 1250 if (cb) 1251 cb(data); 1252 1253 e->end += len; 1254 e->users++; 1255 goto out; 1256 } 1257 } 1258 1259 e = new_writequeue_entry(con); 1260 if (!e) 1261 goto out; 1262 1263 kref_get(&e->ref); 1264 *ppc = page_address(e->page); 1265 e->end += len; 1266 atomic_inc(&con->writequeue_cnt); 1267 if (cb) 1268 cb(data); 1269 1270 list_add_tail(&e->list, &con->writequeue); 1271 1272 out: 1273 spin_unlock(&con->writequeue_lock); 1274 return e; 1275 }; 1276 1277 static struct dlm_msg *dlm_lowcomms_new_msg_con(struct connection *con, int len, 1278 gfp_t allocation, char **ppc, 1279 void (*cb)(void *data), 1280 void *data) 1281 { 1282 struct writequeue_entry *e; 1283 struct dlm_msg *msg; 1284 1285 msg = dlm_allocate_msg(allocation); 1286 if (!msg) 1287 return NULL; 1288 1289 kref_init(&msg->ref); 1290 1291 e = new_wq_entry(con, len, ppc, cb, data); 1292 if (!e) { 1293 dlm_free_msg(msg); 1294 return NULL; 1295 } 1296 1297 msg->retransmit = false; 1298 msg->orig_msg = NULL; 1299 msg->ppc = *ppc; 1300 msg->len = len; 1301 msg->entry = e; 1302 1303 return msg; 1304 } 1305 1306 struct dlm_msg *dlm_lowcomms_new_msg(int nodeid, int len, gfp_t allocation, 1307 char **ppc, void (*cb)(void *data), 1308 void *data) 1309 { 1310 struct connection *con; 1311 struct dlm_msg *msg; 1312 int idx; 1313 1314 if (len > DLM_MAX_SOCKET_BUFSIZE || 1315 len < sizeof(struct dlm_header)) { 1316 BUILD_BUG_ON(PAGE_SIZE < DLM_MAX_SOCKET_BUFSIZE); 1317 log_print("failed to allocate a buffer of size %d", len); 1318 WARN_ON(1); 1319 return NULL; 1320 } 1321 1322 idx = srcu_read_lock(&connections_srcu); 1323 con = nodeid2con(nodeid, allocation); 1324 if (!con) { 1325 srcu_read_unlock(&connections_srcu, idx); 1326 return NULL; 1327 } 1328 1329 msg = dlm_lowcomms_new_msg_con(con, len, allocation, ppc, cb, data); 1330 if (!msg) { 1331 srcu_read_unlock(&connections_srcu, idx); 1332 return NULL; 1333 } 1334 1335 /* we assume if successful commit must called */ 1336 msg->idx = idx; 1337 return msg; 1338 } 1339 1340 static void _dlm_lowcomms_commit_msg(struct dlm_msg *msg) 1341 { 1342 struct writequeue_entry *e = msg->entry; 1343 struct connection *con = e->con; 1344 int users; 1345 1346 spin_lock(&con->writequeue_lock); 1347 kref_get(&msg->ref); 1348 list_add(&msg->list, &e->msgs); 1349 1350 users = --e->users; 1351 if (users) 1352 goto out; 1353 1354 e->len = DLM_WQ_LENGTH_BYTES(e); 1355 spin_unlock(&con->writequeue_lock); 1356 1357 queue_work(send_workqueue, &con->swork); 1358 return; 1359 1360 out: 1361 spin_unlock(&con->writequeue_lock); 1362 return; 1363 } 1364 1365 void dlm_lowcomms_commit_msg(struct dlm_msg *msg) 1366 { 1367 _dlm_lowcomms_commit_msg(msg); 1368 srcu_read_unlock(&connections_srcu, msg->idx); 1369 } 1370 1371 void dlm_lowcomms_put_msg(struct dlm_msg *msg) 1372 { 1373 kref_put(&msg->ref, dlm_msg_release); 1374 } 1375 1376 /* does not held connections_srcu, usage workqueue only */ 1377 int dlm_lowcomms_resend_msg(struct dlm_msg *msg) 1378 { 1379 struct dlm_msg *msg_resend; 1380 char *ppc; 1381 1382 if (msg->retransmit) 1383 return 1; 1384 1385 msg_resend = dlm_lowcomms_new_msg_con(msg->entry->con, msg->len, 1386 GFP_ATOMIC, &ppc, NULL, NULL); 1387 if (!msg_resend) 1388 return -ENOMEM; 1389 1390 msg->retransmit = true; 1391 kref_get(&msg->ref); 1392 msg_resend->orig_msg = msg; 1393 1394 memcpy(ppc, msg->ppc, msg->len); 1395 _dlm_lowcomms_commit_msg(msg_resend); 1396 dlm_lowcomms_put_msg(msg_resend); 1397 1398 return 0; 1399 } 1400 1401 /* Send a message */ 1402 static void send_to_sock(struct connection *con) 1403 { 1404 const int msg_flags = MSG_DONTWAIT | MSG_NOSIGNAL; 1405 struct writequeue_entry *e; 1406 int len, offset, ret; 1407 int count = 0; 1408 1409 mutex_lock(&con->sock_mutex); 1410 if (con->sock == NULL) 1411 goto out_connect; 1412 1413 spin_lock(&con->writequeue_lock); 1414 for (;;) { 1415 e = con_next_wq(con); 1416 if (!e) 1417 break; 1418 1419 len = e->len; 1420 offset = e->offset; 1421 BUG_ON(len == 0 && e->users == 0); 1422 spin_unlock(&con->writequeue_lock); 1423 1424 ret = kernel_sendpage(con->sock, e->page, offset, len, 1425 msg_flags); 1426 trace_dlm_send(con->nodeid, ret); 1427 if (ret == -EAGAIN || ret == 0) { 1428 if (ret == -EAGAIN && 1429 test_bit(SOCKWQ_ASYNC_NOSPACE, &con->sock->flags) && 1430 !test_and_set_bit(CF_APP_LIMITED, &con->flags)) { 1431 /* Notify TCP that we're limited by the 1432 * application window size. 1433 */ 1434 set_bit(SOCK_NOSPACE, &con->sock->flags); 1435 con->sock->sk->sk_write_pending++; 1436 } 1437 cond_resched(); 1438 goto out; 1439 } else if (ret < 0) 1440 goto out; 1441 1442 /* Don't starve people filling buffers */ 1443 if (++count >= MAX_SEND_MSG_COUNT) { 1444 cond_resched(); 1445 count = 0; 1446 } 1447 1448 spin_lock(&con->writequeue_lock); 1449 writequeue_entry_complete(e, ret); 1450 } 1451 spin_unlock(&con->writequeue_lock); 1452 1453 /* close if we got EOF */ 1454 if (test_and_clear_bit(CF_EOF, &con->flags)) { 1455 mutex_unlock(&con->sock_mutex); 1456 close_connection(con, false, false, true); 1457 1458 /* handling for tcp shutdown */ 1459 clear_bit(CF_SHUTDOWN, &con->flags); 1460 wake_up(&con->shutdown_wait); 1461 } else { 1462 mutex_unlock(&con->sock_mutex); 1463 } 1464 1465 return; 1466 1467 out: 1468 mutex_unlock(&con->sock_mutex); 1469 return; 1470 1471 out_connect: 1472 mutex_unlock(&con->sock_mutex); 1473 queue_work(send_workqueue, &con->swork); 1474 cond_resched(); 1475 } 1476 1477 static void clean_one_writequeue(struct connection *con) 1478 { 1479 struct writequeue_entry *e, *safe; 1480 1481 spin_lock(&con->writequeue_lock); 1482 list_for_each_entry_safe(e, safe, &con->writequeue, list) { 1483 free_entry(e); 1484 } 1485 spin_unlock(&con->writequeue_lock); 1486 } 1487 1488 /* Called from recovery when it knows that a node has 1489 left the cluster */ 1490 int dlm_lowcomms_close(int nodeid) 1491 { 1492 struct connection *con; 1493 struct dlm_node_addr *na; 1494 int idx; 1495 1496 log_print("closing connection to node %d", nodeid); 1497 idx = srcu_read_lock(&connections_srcu); 1498 con = nodeid2con(nodeid, 0); 1499 if (con) { 1500 set_bit(CF_CLOSE, &con->flags); 1501 close_connection(con, true, true, true); 1502 clean_one_writequeue(con); 1503 if (con->othercon) 1504 clean_one_writequeue(con->othercon); 1505 } 1506 srcu_read_unlock(&connections_srcu, idx); 1507 1508 spin_lock(&dlm_node_addrs_spin); 1509 na = find_node_addr(nodeid); 1510 if (na) { 1511 list_del(&na->list); 1512 while (na->addr_count--) 1513 kfree(na->addr[na->addr_count]); 1514 kfree(na); 1515 } 1516 spin_unlock(&dlm_node_addrs_spin); 1517 1518 return 0; 1519 } 1520 1521 /* Receive workqueue function */ 1522 static void process_recv_sockets(struct work_struct *work) 1523 { 1524 struct connection *con = container_of(work, struct connection, rwork); 1525 1526 clear_bit(CF_READ_PENDING, &con->flags); 1527 receive_from_sock(con); 1528 } 1529 1530 static void process_listen_recv_socket(struct work_struct *work) 1531 { 1532 accept_from_sock(&listen_con); 1533 } 1534 1535 static void dlm_connect(struct connection *con) 1536 { 1537 struct sockaddr_storage addr; 1538 int result, addr_len; 1539 struct socket *sock; 1540 unsigned int mark; 1541 1542 /* Some odd races can cause double-connects, ignore them */ 1543 if (con->retries++ > MAX_CONNECT_RETRIES) 1544 return; 1545 1546 if (con->sock) { 1547 log_print("node %d already connected.", con->nodeid); 1548 return; 1549 } 1550 1551 memset(&addr, 0, sizeof(addr)); 1552 result = nodeid_to_addr(con->nodeid, &addr, NULL, 1553 dlm_proto_ops->try_new_addr, &mark); 1554 if (result < 0) { 1555 log_print("no address for nodeid %d", con->nodeid); 1556 return; 1557 } 1558 1559 /* Create a socket to communicate with */ 1560 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1561 SOCK_STREAM, dlm_proto_ops->proto, &sock); 1562 if (result < 0) 1563 goto socket_err; 1564 1565 sock_set_mark(sock->sk, mark); 1566 dlm_proto_ops->sockopts(sock); 1567 1568 add_sock(sock, con); 1569 1570 result = dlm_proto_ops->bind(sock); 1571 if (result < 0) 1572 goto add_sock_err; 1573 1574 log_print_ratelimited("connecting to %d", con->nodeid); 1575 make_sockaddr(&addr, dlm_config.ci_tcp_port, &addr_len); 1576 result = dlm_proto_ops->connect(con, sock, (struct sockaddr *)&addr, 1577 addr_len); 1578 if (result < 0) 1579 goto add_sock_err; 1580 1581 return; 1582 1583 add_sock_err: 1584 dlm_close_sock(&con->sock); 1585 1586 socket_err: 1587 /* 1588 * Some errors are fatal and this list might need adjusting. For other 1589 * errors we try again until the max number of retries is reached. 1590 */ 1591 if (result != -EHOSTUNREACH && 1592 result != -ENETUNREACH && 1593 result != -ENETDOWN && 1594 result != -EINVAL && 1595 result != -EPROTONOSUPPORT) { 1596 log_print("connect %d try %d error %d", con->nodeid, 1597 con->retries, result); 1598 msleep(1000); 1599 lowcomms_connect_sock(con); 1600 } 1601 } 1602 1603 /* Send workqueue function */ 1604 static void process_send_sockets(struct work_struct *work) 1605 { 1606 struct connection *con = container_of(work, struct connection, swork); 1607 1608 WARN_ON(test_bit(CF_IS_OTHERCON, &con->flags)); 1609 1610 clear_bit(CF_WRITE_PENDING, &con->flags); 1611 1612 if (test_and_clear_bit(CF_RECONNECT, &con->flags)) { 1613 close_connection(con, false, false, true); 1614 dlm_midcomms_unack_msg_resend(con->nodeid); 1615 } 1616 1617 if (con->sock == NULL) { 1618 if (test_and_clear_bit(CF_DELAY_CONNECT, &con->flags)) 1619 msleep(1000); 1620 1621 mutex_lock(&con->sock_mutex); 1622 dlm_connect(con); 1623 mutex_unlock(&con->sock_mutex); 1624 } 1625 1626 if (!list_empty(&con->writequeue)) 1627 send_to_sock(con); 1628 } 1629 1630 static void work_stop(void) 1631 { 1632 if (recv_workqueue) { 1633 destroy_workqueue(recv_workqueue); 1634 recv_workqueue = NULL; 1635 } 1636 1637 if (send_workqueue) { 1638 destroy_workqueue(send_workqueue); 1639 send_workqueue = NULL; 1640 } 1641 } 1642 1643 static int work_start(void) 1644 { 1645 recv_workqueue = alloc_ordered_workqueue("dlm_recv", WQ_MEM_RECLAIM); 1646 if (!recv_workqueue) { 1647 log_print("can't start dlm_recv"); 1648 return -ENOMEM; 1649 } 1650 1651 send_workqueue = alloc_ordered_workqueue("dlm_send", WQ_MEM_RECLAIM); 1652 if (!send_workqueue) { 1653 log_print("can't start dlm_send"); 1654 destroy_workqueue(recv_workqueue); 1655 recv_workqueue = NULL; 1656 return -ENOMEM; 1657 } 1658 1659 return 0; 1660 } 1661 1662 static void shutdown_conn(struct connection *con) 1663 { 1664 if (dlm_proto_ops->shutdown_action) 1665 dlm_proto_ops->shutdown_action(con); 1666 } 1667 1668 void dlm_lowcomms_shutdown(void) 1669 { 1670 int idx; 1671 1672 /* Set all the flags to prevent any 1673 * socket activity. 1674 */ 1675 dlm_allow_conn = 0; 1676 1677 if (recv_workqueue) 1678 flush_workqueue(recv_workqueue); 1679 if (send_workqueue) 1680 flush_workqueue(send_workqueue); 1681 1682 dlm_close_sock(&listen_con.sock); 1683 1684 idx = srcu_read_lock(&connections_srcu); 1685 foreach_conn(shutdown_conn); 1686 srcu_read_unlock(&connections_srcu, idx); 1687 } 1688 1689 static void _stop_conn(struct connection *con, bool and_other) 1690 { 1691 mutex_lock(&con->sock_mutex); 1692 set_bit(CF_CLOSE, &con->flags); 1693 set_bit(CF_READ_PENDING, &con->flags); 1694 set_bit(CF_WRITE_PENDING, &con->flags); 1695 if (con->sock && con->sock->sk) { 1696 lock_sock(con->sock->sk); 1697 con->sock->sk->sk_user_data = NULL; 1698 release_sock(con->sock->sk); 1699 } 1700 if (con->othercon && and_other) 1701 _stop_conn(con->othercon, false); 1702 mutex_unlock(&con->sock_mutex); 1703 } 1704 1705 static void stop_conn(struct connection *con) 1706 { 1707 _stop_conn(con, true); 1708 } 1709 1710 static void connection_release(struct rcu_head *rcu) 1711 { 1712 struct connection *con = container_of(rcu, struct connection, rcu); 1713 1714 kfree(con->rx_buf); 1715 kfree(con); 1716 } 1717 1718 static void free_conn(struct connection *con) 1719 { 1720 close_connection(con, true, true, true); 1721 spin_lock(&connections_lock); 1722 hlist_del_rcu(&con->list); 1723 spin_unlock(&connections_lock); 1724 if (con->othercon) { 1725 clean_one_writequeue(con->othercon); 1726 call_srcu(&connections_srcu, &con->othercon->rcu, 1727 connection_release); 1728 } 1729 clean_one_writequeue(con); 1730 call_srcu(&connections_srcu, &con->rcu, connection_release); 1731 } 1732 1733 static void work_flush(void) 1734 { 1735 int ok; 1736 int i; 1737 struct connection *con; 1738 1739 do { 1740 ok = 1; 1741 foreach_conn(stop_conn); 1742 if (recv_workqueue) 1743 flush_workqueue(recv_workqueue); 1744 if (send_workqueue) 1745 flush_workqueue(send_workqueue); 1746 for (i = 0; i < CONN_HASH_SIZE && ok; i++) { 1747 hlist_for_each_entry_rcu(con, &connection_hash[i], 1748 list) { 1749 ok &= test_bit(CF_READ_PENDING, &con->flags); 1750 ok &= test_bit(CF_WRITE_PENDING, &con->flags); 1751 if (con->othercon) { 1752 ok &= test_bit(CF_READ_PENDING, 1753 &con->othercon->flags); 1754 ok &= test_bit(CF_WRITE_PENDING, 1755 &con->othercon->flags); 1756 } 1757 } 1758 } 1759 } while (!ok); 1760 } 1761 1762 void dlm_lowcomms_stop(void) 1763 { 1764 int idx; 1765 1766 idx = srcu_read_lock(&connections_srcu); 1767 work_flush(); 1768 foreach_conn(free_conn); 1769 srcu_read_unlock(&connections_srcu, idx); 1770 work_stop(); 1771 deinit_local(); 1772 1773 dlm_proto_ops = NULL; 1774 } 1775 1776 static int dlm_listen_for_all(void) 1777 { 1778 struct socket *sock; 1779 int result; 1780 1781 log_print("Using %s for communications", 1782 dlm_proto_ops->name); 1783 1784 result = dlm_proto_ops->listen_validate(); 1785 if (result < 0) 1786 return result; 1787 1788 result = sock_create_kern(&init_net, dlm_local_addr[0]->ss_family, 1789 SOCK_STREAM, dlm_proto_ops->proto, &sock); 1790 if (result < 0) { 1791 log_print("Can't create comms socket: %d", result); 1792 goto out; 1793 } 1794 1795 sock_set_mark(sock->sk, dlm_config.ci_mark); 1796 dlm_proto_ops->listen_sockopts(sock); 1797 1798 result = dlm_proto_ops->listen_bind(sock); 1799 if (result < 0) 1800 goto out; 1801 1802 save_listen_callbacks(sock); 1803 add_listen_sock(sock, &listen_con); 1804 1805 INIT_WORK(&listen_con.rwork, process_listen_recv_socket); 1806 result = sock->ops->listen(sock, 5); 1807 if (result < 0) { 1808 dlm_close_sock(&listen_con.sock); 1809 goto out; 1810 } 1811 1812 return 0; 1813 1814 out: 1815 sock_release(sock); 1816 return result; 1817 } 1818 1819 static int dlm_tcp_bind(struct socket *sock) 1820 { 1821 struct sockaddr_storage src_addr; 1822 int result, addr_len; 1823 1824 /* Bind to our cluster-known address connecting to avoid 1825 * routing problems. 1826 */ 1827 memcpy(&src_addr, dlm_local_addr[0], sizeof(src_addr)); 1828 make_sockaddr(&src_addr, 0, &addr_len); 1829 1830 result = sock->ops->bind(sock, (struct sockaddr *)&src_addr, 1831 addr_len); 1832 if (result < 0) { 1833 /* This *may* not indicate a critical error */ 1834 log_print("could not bind for connect: %d", result); 1835 } 1836 1837 return 0; 1838 } 1839 1840 static int dlm_tcp_connect(struct connection *con, struct socket *sock, 1841 struct sockaddr *addr, int addr_len) 1842 { 1843 int ret; 1844 1845 ret = sock->ops->connect(sock, addr, addr_len, O_NONBLOCK); 1846 switch (ret) { 1847 case -EINPROGRESS: 1848 fallthrough; 1849 case 0: 1850 return 0; 1851 } 1852 1853 return ret; 1854 } 1855 1856 static int dlm_tcp_listen_validate(void) 1857 { 1858 /* We don't support multi-homed hosts */ 1859 if (dlm_local_count > 1) { 1860 log_print("TCP protocol can't handle multi-homed hosts, try SCTP"); 1861 return -EINVAL; 1862 } 1863 1864 return 0; 1865 } 1866 1867 static void dlm_tcp_sockopts(struct socket *sock) 1868 { 1869 /* Turn off Nagle's algorithm */ 1870 tcp_sock_set_nodelay(sock->sk); 1871 } 1872 1873 static void dlm_tcp_listen_sockopts(struct socket *sock) 1874 { 1875 dlm_tcp_sockopts(sock); 1876 sock_set_reuseaddr(sock->sk); 1877 } 1878 1879 static int dlm_tcp_listen_bind(struct socket *sock) 1880 { 1881 int addr_len; 1882 1883 /* Bind to our port */ 1884 make_sockaddr(dlm_local_addr[0], dlm_config.ci_tcp_port, &addr_len); 1885 return sock->ops->bind(sock, (struct sockaddr *)dlm_local_addr[0], 1886 addr_len); 1887 } 1888 1889 static const struct dlm_proto_ops dlm_tcp_ops = { 1890 .name = "TCP", 1891 .proto = IPPROTO_TCP, 1892 .connect = dlm_tcp_connect, 1893 .sockopts = dlm_tcp_sockopts, 1894 .bind = dlm_tcp_bind, 1895 .listen_validate = dlm_tcp_listen_validate, 1896 .listen_sockopts = dlm_tcp_listen_sockopts, 1897 .listen_bind = dlm_tcp_listen_bind, 1898 .shutdown_action = dlm_tcp_shutdown, 1899 .eof_condition = tcp_eof_condition, 1900 }; 1901 1902 static int dlm_sctp_bind(struct socket *sock) 1903 { 1904 return sctp_bind_addrs(sock, 0); 1905 } 1906 1907 static int dlm_sctp_connect(struct connection *con, struct socket *sock, 1908 struct sockaddr *addr, int addr_len) 1909 { 1910 int ret; 1911 1912 /* 1913 * Make sock->ops->connect() function return in specified time, 1914 * since O_NONBLOCK argument in connect() function does not work here, 1915 * then, we should restore the default value of this attribute. 1916 */ 1917 sock_set_sndtimeo(sock->sk, 5); 1918 ret = sock->ops->connect(sock, addr, addr_len, 0); 1919 sock_set_sndtimeo(sock->sk, 0); 1920 if (ret < 0) 1921 return ret; 1922 1923 if (!test_and_set_bit(CF_CONNECTED, &con->flags)) 1924 log_print("successful connected to node %d", con->nodeid); 1925 1926 return 0; 1927 } 1928 1929 static int dlm_sctp_listen_validate(void) 1930 { 1931 if (!IS_ENABLED(CONFIG_IP_SCTP)) { 1932 log_print("SCTP is not enabled by this kernel"); 1933 return -EOPNOTSUPP; 1934 } 1935 1936 request_module("sctp"); 1937 return 0; 1938 } 1939 1940 static int dlm_sctp_bind_listen(struct socket *sock) 1941 { 1942 return sctp_bind_addrs(sock, dlm_config.ci_tcp_port); 1943 } 1944 1945 static void dlm_sctp_sockopts(struct socket *sock) 1946 { 1947 /* Turn off Nagle's algorithm */ 1948 sctp_sock_set_nodelay(sock->sk); 1949 sock_set_rcvbuf(sock->sk, NEEDED_RMEM); 1950 } 1951 1952 static const struct dlm_proto_ops dlm_sctp_ops = { 1953 .name = "SCTP", 1954 .proto = IPPROTO_SCTP, 1955 .try_new_addr = true, 1956 .connect = dlm_sctp_connect, 1957 .sockopts = dlm_sctp_sockopts, 1958 .bind = dlm_sctp_bind, 1959 .listen_validate = dlm_sctp_listen_validate, 1960 .listen_sockopts = dlm_sctp_sockopts, 1961 .listen_bind = dlm_sctp_bind_listen, 1962 }; 1963 1964 int dlm_lowcomms_start(void) 1965 { 1966 int error = -EINVAL; 1967 int i; 1968 1969 for (i = 0; i < CONN_HASH_SIZE; i++) 1970 INIT_HLIST_HEAD(&connection_hash[i]); 1971 1972 init_local(); 1973 if (!dlm_local_count) { 1974 error = -ENOTCONN; 1975 log_print("no local IP address has been set"); 1976 goto fail; 1977 } 1978 1979 INIT_WORK(&listen_con.rwork, process_listen_recv_socket); 1980 1981 error = work_start(); 1982 if (error) 1983 goto fail_local; 1984 1985 dlm_allow_conn = 1; 1986 1987 /* Start listening */ 1988 switch (dlm_config.ci_protocol) { 1989 case DLM_PROTO_TCP: 1990 dlm_proto_ops = &dlm_tcp_ops; 1991 break; 1992 case DLM_PROTO_SCTP: 1993 dlm_proto_ops = &dlm_sctp_ops; 1994 break; 1995 default: 1996 log_print("Invalid protocol identifier %d set", 1997 dlm_config.ci_protocol); 1998 error = -EINVAL; 1999 goto fail_proto_ops; 2000 } 2001 2002 error = dlm_listen_for_all(); 2003 if (error) 2004 goto fail_listen; 2005 2006 return 0; 2007 2008 fail_listen: 2009 dlm_proto_ops = NULL; 2010 fail_proto_ops: 2011 dlm_allow_conn = 0; 2012 dlm_close_sock(&listen_con.sock); 2013 work_stop(); 2014 fail_local: 2015 deinit_local(); 2016 fail: 2017 return error; 2018 } 2019 2020 void dlm_lowcomms_exit(void) 2021 { 2022 struct dlm_node_addr *na, *safe; 2023 2024 spin_lock(&dlm_node_addrs_spin); 2025 list_for_each_entry_safe(na, safe, &dlm_node_addrs, list) { 2026 list_del(&na->list); 2027 while (na->addr_count--) 2028 kfree(na->addr[na->addr_count]); 2029 kfree(na); 2030 } 2031 spin_unlock(&dlm_node_addrs_spin); 2032 } 2033