1 /* RxRPC individual remote procedure call handling 2 * 3 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. 4 * Written by David Howells (dhowells@redhat.com) 5 * 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt 13 14 #include <linux/slab.h> 15 #include <linux/module.h> 16 #include <linux/circ_buf.h> 17 #include <linux/spinlock_types.h> 18 #include <net/sock.h> 19 #include <net/af_rxrpc.h> 20 #include "ar-internal.h" 21 22 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = { 23 [RXRPC_CALL_UNINITIALISED] = "Uninit ", 24 [RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn", 25 [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq", 26 [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl", 27 [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl", 28 [RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc", 29 [RXRPC_CALL_SERVER_SECURING] = "SvSecure", 30 [RXRPC_CALL_SERVER_ACCEPTING] = "SvAccept", 31 [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq", 32 [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq", 33 [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl", 34 [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK", 35 [RXRPC_CALL_COMPLETE] = "Complete", 36 }; 37 38 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = { 39 [RXRPC_CALL_SUCCEEDED] = "Complete", 40 [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort", 41 [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort", 42 [RXRPC_CALL_LOCAL_ERROR] = "LocError", 43 [RXRPC_CALL_NETWORK_ERROR] = "NetError", 44 }; 45 46 struct kmem_cache *rxrpc_call_jar; 47 48 static void rxrpc_call_timer_expired(struct timer_list *t) 49 { 50 struct rxrpc_call *call = from_timer(call, t, timer); 51 52 _enter("%d", call->debug_id); 53 54 if (call->state < RXRPC_CALL_COMPLETE) { 55 trace_rxrpc_timer(call, rxrpc_timer_expired, jiffies); 56 rxrpc_queue_call(call); 57 } 58 } 59 60 static struct lock_class_key rxrpc_call_user_mutex_lock_class_key; 61 62 /* 63 * find an extant server call 64 * - called in process context with IRQs enabled 65 */ 66 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx, 67 unsigned long user_call_ID) 68 { 69 struct rxrpc_call *call; 70 struct rb_node *p; 71 72 _enter("%p,%lx", rx, user_call_ID); 73 74 read_lock(&rx->call_lock); 75 76 p = rx->calls.rb_node; 77 while (p) { 78 call = rb_entry(p, struct rxrpc_call, sock_node); 79 80 if (user_call_ID < call->user_call_ID) 81 p = p->rb_left; 82 else if (user_call_ID > call->user_call_ID) 83 p = p->rb_right; 84 else 85 goto found_extant_call; 86 } 87 88 read_unlock(&rx->call_lock); 89 _leave(" = NULL"); 90 return NULL; 91 92 found_extant_call: 93 rxrpc_get_call(call, rxrpc_call_got); 94 read_unlock(&rx->call_lock); 95 _leave(" = %p [%d]", call, atomic_read(&call->usage)); 96 return call; 97 } 98 99 /* 100 * allocate a new call 101 */ 102 struct rxrpc_call *rxrpc_alloc_call(struct rxrpc_sock *rx, gfp_t gfp, 103 unsigned int debug_id) 104 { 105 struct rxrpc_call *call; 106 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk)); 107 108 call = kmem_cache_zalloc(rxrpc_call_jar, gfp); 109 if (!call) 110 return NULL; 111 112 call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE, 113 sizeof(struct sk_buff *), 114 gfp); 115 if (!call->rxtx_buffer) 116 goto nomem; 117 118 call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp); 119 if (!call->rxtx_annotations) 120 goto nomem_2; 121 122 mutex_init(&call->user_mutex); 123 124 /* Prevent lockdep reporting a deadlock false positive between the afs 125 * filesystem and sys_sendmsg() via the mmap sem. 126 */ 127 if (rx->sk.sk_kern_sock) 128 lockdep_set_class(&call->user_mutex, 129 &rxrpc_call_user_mutex_lock_class_key); 130 131 timer_setup(&call->timer, rxrpc_call_timer_expired, 0); 132 INIT_WORK(&call->processor, &rxrpc_process_call); 133 INIT_LIST_HEAD(&call->link); 134 INIT_LIST_HEAD(&call->chan_wait_link); 135 INIT_LIST_HEAD(&call->accept_link); 136 INIT_LIST_HEAD(&call->recvmsg_link); 137 INIT_LIST_HEAD(&call->sock_link); 138 init_waitqueue_head(&call->waitq); 139 spin_lock_init(&call->lock); 140 spin_lock_init(&call->notify_lock); 141 spin_lock_init(&call->input_lock); 142 rwlock_init(&call->state_lock); 143 atomic_set(&call->usage, 1); 144 call->debug_id = debug_id; 145 call->tx_total_len = -1; 146 call->next_rx_timo = 20 * HZ; 147 call->next_req_timo = 1 * HZ; 148 149 memset(&call->sock_node, 0xed, sizeof(call->sock_node)); 150 151 /* Leave space in the ring to handle a maxed-out jumbo packet */ 152 call->rx_winsize = rxrpc_rx_window_size; 153 call->tx_winsize = 16; 154 call->rx_expect_next = 1; 155 156 call->cong_cwnd = 2; 157 call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1; 158 159 call->rxnet = rxnet; 160 atomic_inc(&rxnet->nr_calls); 161 return call; 162 163 nomem_2: 164 kfree(call->rxtx_buffer); 165 nomem: 166 kmem_cache_free(rxrpc_call_jar, call); 167 return NULL; 168 } 169 170 /* 171 * Allocate a new client call. 172 */ 173 static struct rxrpc_call *rxrpc_alloc_client_call(struct rxrpc_sock *rx, 174 struct sockaddr_rxrpc *srx, 175 gfp_t gfp, 176 unsigned int debug_id) 177 { 178 struct rxrpc_call *call; 179 ktime_t now; 180 181 _enter(""); 182 183 call = rxrpc_alloc_call(rx, gfp, debug_id); 184 if (!call) 185 return ERR_PTR(-ENOMEM); 186 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; 187 call->service_id = srx->srx_service; 188 call->tx_phase = true; 189 now = ktime_get_real(); 190 call->acks_latest_ts = now; 191 call->cong_tstamp = now; 192 193 _leave(" = %p", call); 194 return call; 195 } 196 197 /* 198 * Initiate the call ack/resend/expiry timer. 199 */ 200 static void rxrpc_start_call_timer(struct rxrpc_call *call) 201 { 202 unsigned long now = jiffies; 203 unsigned long j = now + MAX_JIFFY_OFFSET; 204 205 call->ack_at = j; 206 call->ack_lost_at = j; 207 call->resend_at = j; 208 call->ping_at = j; 209 call->expect_rx_by = j; 210 call->expect_req_by = j; 211 call->expect_term_by = j; 212 call->timer.expires = now; 213 } 214 215 /* 216 * Set up a call for the given parameters. 217 * - Called with the socket lock held, which it must release. 218 * - If it returns a call, the call's lock will need releasing by the caller. 219 */ 220 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, 221 struct rxrpc_conn_parameters *cp, 222 struct sockaddr_rxrpc *srx, 223 struct rxrpc_call_params *p, 224 gfp_t gfp, 225 unsigned int debug_id) 226 __releases(&rx->sk.sk_lock.slock) 227 __acquires(&call->user_mutex) 228 { 229 struct rxrpc_call *call, *xcall; 230 struct rxrpc_net *rxnet; 231 struct rb_node *parent, **pp; 232 const void *here = __builtin_return_address(0); 233 int ret; 234 235 _enter("%p,%lx", rx, p->user_call_ID); 236 237 call = rxrpc_alloc_client_call(rx, srx, gfp, debug_id); 238 if (IS_ERR(call)) { 239 release_sock(&rx->sk); 240 _leave(" = %ld", PTR_ERR(call)); 241 return call; 242 } 243 244 call->tx_total_len = p->tx_total_len; 245 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), 246 here, (const void *)p->user_call_ID); 247 248 /* We need to protect a partially set up call against the user as we 249 * will be acting outside the socket lock. 250 */ 251 mutex_lock(&call->user_mutex); 252 253 /* Publish the call, even though it is incompletely set up as yet */ 254 write_lock(&rx->call_lock); 255 256 pp = &rx->calls.rb_node; 257 parent = NULL; 258 while (*pp) { 259 parent = *pp; 260 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 261 262 if (p->user_call_ID < xcall->user_call_ID) 263 pp = &(*pp)->rb_left; 264 else if (p->user_call_ID > xcall->user_call_ID) 265 pp = &(*pp)->rb_right; 266 else 267 goto error_dup_user_ID; 268 } 269 270 rcu_assign_pointer(call->socket, rx); 271 call->user_call_ID = p->user_call_ID; 272 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 273 rxrpc_get_call(call, rxrpc_call_got_userid); 274 rb_link_node(&call->sock_node, parent, pp); 275 rb_insert_color(&call->sock_node, &rx->calls); 276 list_add(&call->sock_link, &rx->sock_calls); 277 278 write_unlock(&rx->call_lock); 279 280 rxnet = call->rxnet; 281 write_lock(&rxnet->call_lock); 282 list_add_tail(&call->link, &rxnet->calls); 283 write_unlock(&rxnet->call_lock); 284 285 /* From this point on, the call is protected by its own lock. */ 286 release_sock(&rx->sk); 287 288 /* Set up or get a connection record and set the protocol parameters, 289 * including channel number and call ID. 290 */ 291 ret = rxrpc_connect_call(rx, call, cp, srx, gfp); 292 if (ret < 0) 293 goto error; 294 295 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage), 296 here, NULL); 297 298 rxrpc_start_call_timer(call); 299 300 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); 301 302 _leave(" = %p [new]", call); 303 return call; 304 305 /* We unexpectedly found the user ID in the list after taking 306 * the call_lock. This shouldn't happen unless the user races 307 * with itself and tries to add the same user ID twice at the 308 * same time in different threads. 309 */ 310 error_dup_user_ID: 311 write_unlock(&rx->call_lock); 312 release_sock(&rx->sk); 313 ret = -EEXIST; 314 315 error: 316 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 317 RX_CALL_DEAD, ret); 318 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage), 319 here, ERR_PTR(ret)); 320 rxrpc_release_call(rx, call); 321 mutex_unlock(&call->user_mutex); 322 rxrpc_put_call(call, rxrpc_call_put); 323 _leave(" = %d", ret); 324 return ERR_PTR(ret); 325 } 326 327 /* 328 * Set up an incoming call. call->conn points to the connection. 329 * This is called in BH context and isn't allowed to fail. 330 */ 331 void rxrpc_incoming_call(struct rxrpc_sock *rx, 332 struct rxrpc_call *call, 333 struct sk_buff *skb) 334 { 335 struct rxrpc_connection *conn = call->conn; 336 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 337 u32 chan; 338 339 _enter(",%d", call->conn->debug_id); 340 341 rcu_assign_pointer(call->socket, rx); 342 call->call_id = sp->hdr.callNumber; 343 call->service_id = sp->hdr.serviceId; 344 call->cid = sp->hdr.cid; 345 call->state = RXRPC_CALL_SERVER_ACCEPTING; 346 if (sp->hdr.securityIndex > 0) 347 call->state = RXRPC_CALL_SERVER_SECURING; 348 call->cong_tstamp = skb->tstamp; 349 350 /* Set the channel for this call. We don't get channel_lock as we're 351 * only defending against the data_ready handler (which we're called 352 * from) and the RESPONSE packet parser (which is only really 353 * interested in call_counter and can cope with a disagreement with the 354 * call pointer). 355 */ 356 chan = sp->hdr.cid & RXRPC_CHANNELMASK; 357 conn->channels[chan].call_counter = call->call_id; 358 conn->channels[chan].call_id = call->call_id; 359 rcu_assign_pointer(conn->channels[chan].call, call); 360 361 spin_lock(&conn->params.peer->lock); 362 hlist_add_head_rcu(&call->error_link, &conn->params.peer->error_targets); 363 spin_unlock(&conn->params.peer->lock); 364 365 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); 366 367 rxrpc_start_call_timer(call); 368 _leave(""); 369 } 370 371 /* 372 * Queue a call's work processor, getting a ref to pass to the work queue. 373 */ 374 bool rxrpc_queue_call(struct rxrpc_call *call) 375 { 376 const void *here = __builtin_return_address(0); 377 int n = atomic_fetch_add_unless(&call->usage, 1, 0); 378 if (n == 0) 379 return false; 380 if (rxrpc_queue_work(&call->processor)) 381 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); 382 else 383 rxrpc_put_call(call, rxrpc_call_put_noqueue); 384 return true; 385 } 386 387 /* 388 * Queue a call's work processor, passing the callers ref to the work queue. 389 */ 390 bool __rxrpc_queue_call(struct rxrpc_call *call) 391 { 392 const void *here = __builtin_return_address(0); 393 int n = atomic_read(&call->usage); 394 ASSERTCMP(n, >=, 1); 395 if (rxrpc_queue_work(&call->processor)) 396 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); 397 else 398 rxrpc_put_call(call, rxrpc_call_put_noqueue); 399 return true; 400 } 401 402 /* 403 * Note the re-emergence of a call. 404 */ 405 void rxrpc_see_call(struct rxrpc_call *call) 406 { 407 const void *here = __builtin_return_address(0); 408 if (call) { 409 int n = atomic_read(&call->usage); 410 411 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); 412 } 413 } 414 415 /* 416 * Note the addition of a ref on a call. 417 */ 418 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 419 { 420 const void *here = __builtin_return_address(0); 421 int n = atomic_inc_return(&call->usage); 422 423 trace_rxrpc_call(call, op, n, here, NULL); 424 } 425 426 /* 427 * Detach a call from its owning socket. 428 */ 429 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) 430 { 431 const void *here = __builtin_return_address(0); 432 struct rxrpc_connection *conn = call->conn; 433 bool put = false; 434 int i; 435 436 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); 437 438 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage), 439 here, (const void *)call->flags); 440 441 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 442 443 spin_lock_bh(&call->lock); 444 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) 445 BUG(); 446 spin_unlock_bh(&call->lock); 447 448 del_timer_sync(&call->timer); 449 450 /* Make sure we don't get any more notifications */ 451 write_lock_bh(&rx->recvmsg_lock); 452 453 if (!list_empty(&call->recvmsg_link)) { 454 _debug("unlinking once-pending call %p { e=%lx f=%lx }", 455 call, call->events, call->flags); 456 list_del(&call->recvmsg_link); 457 put = true; 458 } 459 460 /* list_empty() must return false in rxrpc_notify_socket() */ 461 call->recvmsg_link.next = NULL; 462 call->recvmsg_link.prev = NULL; 463 464 write_unlock_bh(&rx->recvmsg_lock); 465 if (put) 466 rxrpc_put_call(call, rxrpc_call_put); 467 468 write_lock(&rx->call_lock); 469 470 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 471 rb_erase(&call->sock_node, &rx->calls); 472 memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); 473 rxrpc_put_call(call, rxrpc_call_put_userid); 474 } 475 476 list_del(&call->sock_link); 477 write_unlock(&rx->call_lock); 478 479 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); 480 481 if (conn) 482 rxrpc_disconnect_call(call); 483 484 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { 485 rxrpc_free_skb(call->rxtx_buffer[i], 486 (call->tx_phase ? rxrpc_skb_tx_cleaned : 487 rxrpc_skb_rx_cleaned)); 488 call->rxtx_buffer[i] = NULL; 489 } 490 491 _leave(""); 492 } 493 494 /* 495 * release all the calls associated with a socket 496 */ 497 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) 498 { 499 struct rxrpc_call *call; 500 501 _enter("%p", rx); 502 503 while (!list_empty(&rx->to_be_accepted)) { 504 call = list_entry(rx->to_be_accepted.next, 505 struct rxrpc_call, accept_link); 506 list_del(&call->accept_link); 507 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET); 508 rxrpc_put_call(call, rxrpc_call_put); 509 } 510 511 while (!list_empty(&rx->sock_calls)) { 512 call = list_entry(rx->sock_calls.next, 513 struct rxrpc_call, sock_link); 514 rxrpc_get_call(call, rxrpc_call_got); 515 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET); 516 rxrpc_send_abort_packet(call); 517 rxrpc_release_call(rx, call); 518 rxrpc_put_call(call, rxrpc_call_put); 519 } 520 521 _leave(""); 522 } 523 524 /* 525 * release a call 526 */ 527 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 528 { 529 struct rxrpc_net *rxnet = call->rxnet; 530 const void *here = __builtin_return_address(0); 531 int n; 532 533 ASSERT(call != NULL); 534 535 n = atomic_dec_return(&call->usage); 536 trace_rxrpc_call(call, op, n, here, NULL); 537 ASSERTCMP(n, >=, 0); 538 if (n == 0) { 539 _debug("call %d dead", call->debug_id); 540 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 541 542 if (!list_empty(&call->link)) { 543 write_lock(&rxnet->call_lock); 544 list_del_init(&call->link); 545 write_unlock(&rxnet->call_lock); 546 } 547 548 rxrpc_cleanup_call(call); 549 } 550 } 551 552 /* 553 * Final call destruction under RCU. 554 */ 555 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) 556 { 557 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); 558 struct rxrpc_net *rxnet = call->rxnet; 559 560 rxrpc_put_peer(call->peer); 561 kfree(call->rxtx_buffer); 562 kfree(call->rxtx_annotations); 563 kmem_cache_free(rxrpc_call_jar, call); 564 if (atomic_dec_and_test(&rxnet->nr_calls)) 565 wake_up_var(&rxnet->nr_calls); 566 } 567 568 /* 569 * clean up a call 570 */ 571 void rxrpc_cleanup_call(struct rxrpc_call *call) 572 { 573 int i; 574 575 _net("DESTROY CALL %d", call->debug_id); 576 577 memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); 578 579 del_timer_sync(&call->timer); 580 581 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 582 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); 583 ASSERTCMP(call->conn, ==, NULL); 584 585 /* Clean up the Rx/Tx buffer */ 586 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) 587 rxrpc_free_skb(call->rxtx_buffer[i], 588 (call->tx_phase ? rxrpc_skb_tx_cleaned : 589 rxrpc_skb_rx_cleaned)); 590 591 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned); 592 593 call_rcu(&call->rcu, rxrpc_rcu_destroy_call); 594 } 595 596 /* 597 * Make sure that all calls are gone from a network namespace. To reach this 598 * point, any open UDP sockets in that namespace must have been closed, so any 599 * outstanding calls cannot be doing I/O. 600 */ 601 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet) 602 { 603 struct rxrpc_call *call; 604 605 _enter(""); 606 607 if (list_empty(&rxnet->calls)) 608 return; 609 610 write_lock(&rxnet->call_lock); 611 612 while (!list_empty(&rxnet->calls)) { 613 call = list_entry(rxnet->calls.next, struct rxrpc_call, link); 614 _debug("Zapping call %p", call); 615 616 rxrpc_see_call(call); 617 list_del_init(&call->link); 618 619 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", 620 call, atomic_read(&call->usage), 621 rxrpc_call_states[call->state], 622 call->flags, call->events); 623 624 write_unlock(&rxnet->call_lock); 625 cond_resched(); 626 write_lock(&rxnet->call_lock); 627 } 628 629 write_unlock(&rxnet->call_lock); 630 631 atomic_dec(&rxnet->nr_calls); 632 wait_var_event(&rxnet->nr_calls, !atomic_read(&rxnet->nr_calls)); 633 } 634