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(unsigned long _call) 49 { 50 struct rxrpc_call *call = (struct rxrpc_call *)_call; 51 52 _enter("%d", call->debug_id); 53 54 if (call->state < RXRPC_CALL_COMPLETE) 55 rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real()); 56 } 57 58 /* 59 * find an extant server call 60 * - called in process context with IRQs enabled 61 */ 62 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx, 63 unsigned long user_call_ID) 64 { 65 struct rxrpc_call *call; 66 struct rb_node *p; 67 68 _enter("%p,%lx", rx, user_call_ID); 69 70 read_lock(&rx->call_lock); 71 72 p = rx->calls.rb_node; 73 while (p) { 74 call = rb_entry(p, struct rxrpc_call, sock_node); 75 76 if (user_call_ID < call->user_call_ID) 77 p = p->rb_left; 78 else if (user_call_ID > call->user_call_ID) 79 p = p->rb_right; 80 else 81 goto found_extant_call; 82 } 83 84 read_unlock(&rx->call_lock); 85 _leave(" = NULL"); 86 return NULL; 87 88 found_extant_call: 89 rxrpc_get_call(call, rxrpc_call_got); 90 read_unlock(&rx->call_lock); 91 _leave(" = %p [%d]", call, atomic_read(&call->usage)); 92 return call; 93 } 94 95 /* 96 * allocate a new call 97 */ 98 struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) 99 { 100 struct rxrpc_call *call; 101 102 call = kmem_cache_zalloc(rxrpc_call_jar, gfp); 103 if (!call) 104 return NULL; 105 106 call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE, 107 sizeof(struct sk_buff *), 108 gfp); 109 if (!call->rxtx_buffer) 110 goto nomem; 111 112 call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp); 113 if (!call->rxtx_annotations) 114 goto nomem_2; 115 116 mutex_init(&call->user_mutex); 117 setup_timer(&call->timer, rxrpc_call_timer_expired, 118 (unsigned long)call); 119 INIT_WORK(&call->processor, &rxrpc_process_call); 120 INIT_LIST_HEAD(&call->link); 121 INIT_LIST_HEAD(&call->chan_wait_link); 122 INIT_LIST_HEAD(&call->accept_link); 123 INIT_LIST_HEAD(&call->recvmsg_link); 124 INIT_LIST_HEAD(&call->sock_link); 125 init_waitqueue_head(&call->waitq); 126 spin_lock_init(&call->lock); 127 rwlock_init(&call->state_lock); 128 atomic_set(&call->usage, 1); 129 call->debug_id = atomic_inc_return(&rxrpc_debug_id); 130 131 memset(&call->sock_node, 0xed, sizeof(call->sock_node)); 132 133 /* Leave space in the ring to handle a maxed-out jumbo packet */ 134 call->rx_winsize = rxrpc_rx_window_size; 135 call->tx_winsize = 16; 136 call->rx_expect_next = 1; 137 138 if (RXRPC_TX_SMSS > 2190) 139 call->cong_cwnd = 2; 140 else if (RXRPC_TX_SMSS > 1095) 141 call->cong_cwnd = 3; 142 else 143 call->cong_cwnd = 4; 144 call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1; 145 return call; 146 147 nomem_2: 148 kfree(call->rxtx_buffer); 149 nomem: 150 kmem_cache_free(rxrpc_call_jar, call); 151 return NULL; 152 } 153 154 /* 155 * Allocate a new client call. 156 */ 157 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, 158 gfp_t gfp) 159 { 160 struct rxrpc_call *call; 161 ktime_t now; 162 163 _enter(""); 164 165 call = rxrpc_alloc_call(gfp); 166 if (!call) 167 return ERR_PTR(-ENOMEM); 168 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; 169 call->service_id = srx->srx_service; 170 call->tx_phase = true; 171 now = ktime_get_real(); 172 call->acks_latest_ts = now; 173 call->cong_tstamp = now; 174 175 _leave(" = %p", call); 176 return call; 177 } 178 179 /* 180 * Initiate the call ack/resend/expiry timer. 181 */ 182 static void rxrpc_start_call_timer(struct rxrpc_call *call) 183 { 184 ktime_t now = ktime_get_real(), expire_at; 185 186 expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime); 187 call->expire_at = expire_at; 188 call->ack_at = expire_at; 189 call->ping_at = expire_at; 190 call->resend_at = expire_at; 191 call->timer.expires = jiffies + LONG_MAX / 2; 192 rxrpc_set_timer(call, rxrpc_timer_begin, now); 193 } 194 195 /* 196 * Set up a call for the given parameters. 197 * - Called with the socket lock held, which it must release. 198 * - If it returns a call, the call's lock will need releasing by the caller. 199 */ 200 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, 201 struct rxrpc_conn_parameters *cp, 202 struct sockaddr_rxrpc *srx, 203 unsigned long user_call_ID, 204 gfp_t gfp) 205 __releases(&rx->sk.sk_lock.slock) 206 { 207 struct rxrpc_call *call, *xcall; 208 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk)); 209 struct rb_node *parent, **pp; 210 const void *here = __builtin_return_address(0); 211 int ret; 212 213 _enter("%p,%lx", rx, user_call_ID); 214 215 call = rxrpc_alloc_client_call(srx, gfp); 216 if (IS_ERR(call)) { 217 release_sock(&rx->sk); 218 _leave(" = %ld", PTR_ERR(call)); 219 return call; 220 } 221 222 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), 223 here, (const void *)user_call_ID); 224 225 /* We need to protect a partially set up call against the user as we 226 * will be acting outside the socket lock. 227 */ 228 mutex_lock(&call->user_mutex); 229 230 /* Publish the call, even though it is incompletely set up as yet */ 231 write_lock(&rx->call_lock); 232 233 pp = &rx->calls.rb_node; 234 parent = NULL; 235 while (*pp) { 236 parent = *pp; 237 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 238 239 if (user_call_ID < xcall->user_call_ID) 240 pp = &(*pp)->rb_left; 241 else if (user_call_ID > xcall->user_call_ID) 242 pp = &(*pp)->rb_right; 243 else 244 goto error_dup_user_ID; 245 } 246 247 rcu_assign_pointer(call->socket, rx); 248 call->user_call_ID = user_call_ID; 249 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 250 rxrpc_get_call(call, rxrpc_call_got_userid); 251 rb_link_node(&call->sock_node, parent, pp); 252 rb_insert_color(&call->sock_node, &rx->calls); 253 list_add(&call->sock_link, &rx->sock_calls); 254 255 write_unlock(&rx->call_lock); 256 257 write_lock(&rxnet->call_lock); 258 list_add_tail(&call->link, &rxnet->calls); 259 write_unlock(&rxnet->call_lock); 260 261 /* From this point on, the call is protected by its own lock. */ 262 release_sock(&rx->sk); 263 264 /* Set up or get a connection record and set the protocol parameters, 265 * including channel number and call ID. 266 */ 267 ret = rxrpc_connect_call(call, cp, srx, gfp); 268 if (ret < 0) 269 goto error; 270 271 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage), 272 here, NULL); 273 274 spin_lock_bh(&call->conn->params.peer->lock); 275 hlist_add_head(&call->error_link, 276 &call->conn->params.peer->error_targets); 277 spin_unlock_bh(&call->conn->params.peer->lock); 278 279 rxrpc_start_call_timer(call); 280 281 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); 282 283 _leave(" = %p [new]", call); 284 return call; 285 286 /* We unexpectedly found the user ID in the list after taking 287 * the call_lock. This shouldn't happen unless the user races 288 * with itself and tries to add the same user ID twice at the 289 * same time in different threads. 290 */ 291 error_dup_user_ID: 292 write_unlock(&rx->call_lock); 293 release_sock(&rx->sk); 294 ret = -EEXIST; 295 296 error: 297 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 298 RX_CALL_DEAD, ret); 299 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage), 300 here, ERR_PTR(ret)); 301 rxrpc_release_call(rx, call); 302 mutex_unlock(&call->user_mutex); 303 rxrpc_put_call(call, rxrpc_call_put); 304 _leave(" = %d", ret); 305 return ERR_PTR(ret); 306 } 307 308 /* 309 * Set up an incoming call. call->conn points to the connection. 310 * This is called in BH context and isn't allowed to fail. 311 */ 312 void rxrpc_incoming_call(struct rxrpc_sock *rx, 313 struct rxrpc_call *call, 314 struct sk_buff *skb) 315 { 316 struct rxrpc_connection *conn = call->conn; 317 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 318 u32 chan; 319 320 _enter(",%d", call->conn->debug_id); 321 322 rcu_assign_pointer(call->socket, rx); 323 call->call_id = sp->hdr.callNumber; 324 call->service_id = sp->hdr.serviceId; 325 call->cid = sp->hdr.cid; 326 call->state = RXRPC_CALL_SERVER_ACCEPTING; 327 if (sp->hdr.securityIndex > 0) 328 call->state = RXRPC_CALL_SERVER_SECURING; 329 call->cong_tstamp = skb->tstamp; 330 331 /* Set the channel for this call. We don't get channel_lock as we're 332 * only defending against the data_ready handler (which we're called 333 * from) and the RESPONSE packet parser (which is only really 334 * interested in call_counter and can cope with a disagreement with the 335 * call pointer). 336 */ 337 chan = sp->hdr.cid & RXRPC_CHANNELMASK; 338 conn->channels[chan].call_counter = call->call_id; 339 conn->channels[chan].call_id = call->call_id; 340 rcu_assign_pointer(conn->channels[chan].call, call); 341 342 spin_lock(&conn->params.peer->lock); 343 hlist_add_head(&call->error_link, &conn->params.peer->error_targets); 344 spin_unlock(&conn->params.peer->lock); 345 346 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); 347 348 rxrpc_start_call_timer(call); 349 _leave(""); 350 } 351 352 /* 353 * Queue a call's work processor, getting a ref to pass to the work queue. 354 */ 355 bool rxrpc_queue_call(struct rxrpc_call *call) 356 { 357 const void *here = __builtin_return_address(0); 358 int n = __atomic_add_unless(&call->usage, 1, 0); 359 if (n == 0) 360 return false; 361 if (rxrpc_queue_work(&call->processor)) 362 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); 363 else 364 rxrpc_put_call(call, rxrpc_call_put_noqueue); 365 return true; 366 } 367 368 /* 369 * Queue a call's work processor, passing the callers ref to the work queue. 370 */ 371 bool __rxrpc_queue_call(struct rxrpc_call *call) 372 { 373 const void *here = __builtin_return_address(0); 374 int n = atomic_read(&call->usage); 375 ASSERTCMP(n, >=, 1); 376 if (rxrpc_queue_work(&call->processor)) 377 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); 378 else 379 rxrpc_put_call(call, rxrpc_call_put_noqueue); 380 return true; 381 } 382 383 /* 384 * Note the re-emergence of a call. 385 */ 386 void rxrpc_see_call(struct rxrpc_call *call) 387 { 388 const void *here = __builtin_return_address(0); 389 if (call) { 390 int n = atomic_read(&call->usage); 391 392 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); 393 } 394 } 395 396 /* 397 * Note the addition of a ref on a call. 398 */ 399 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 400 { 401 const void *here = __builtin_return_address(0); 402 int n = atomic_inc_return(&call->usage); 403 404 trace_rxrpc_call(call, op, n, here, NULL); 405 } 406 407 /* 408 * Detach a call from its owning socket. 409 */ 410 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) 411 { 412 const void *here = __builtin_return_address(0); 413 struct rxrpc_connection *conn = call->conn; 414 bool put = false; 415 int i; 416 417 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); 418 419 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage), 420 here, (const void *)call->flags); 421 422 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 423 424 spin_lock_bh(&call->lock); 425 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) 426 BUG(); 427 spin_unlock_bh(&call->lock); 428 429 del_timer_sync(&call->timer); 430 431 /* Make sure we don't get any more notifications */ 432 write_lock_bh(&rx->recvmsg_lock); 433 434 if (!list_empty(&call->recvmsg_link)) { 435 _debug("unlinking once-pending call %p { e=%lx f=%lx }", 436 call, call->events, call->flags); 437 list_del(&call->recvmsg_link); 438 put = true; 439 } 440 441 /* list_empty() must return false in rxrpc_notify_socket() */ 442 call->recvmsg_link.next = NULL; 443 call->recvmsg_link.prev = NULL; 444 445 write_unlock_bh(&rx->recvmsg_lock); 446 if (put) 447 rxrpc_put_call(call, rxrpc_call_put); 448 449 write_lock(&rx->call_lock); 450 451 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 452 rb_erase(&call->sock_node, &rx->calls); 453 memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); 454 rxrpc_put_call(call, rxrpc_call_put_userid); 455 } 456 457 list_del(&call->sock_link); 458 write_unlock(&rx->call_lock); 459 460 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); 461 462 if (conn) 463 rxrpc_disconnect_call(call); 464 465 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { 466 rxrpc_free_skb(call->rxtx_buffer[i], 467 (call->tx_phase ? rxrpc_skb_tx_cleaned : 468 rxrpc_skb_rx_cleaned)); 469 call->rxtx_buffer[i] = NULL; 470 } 471 472 _leave(""); 473 } 474 475 /* 476 * release all the calls associated with a socket 477 */ 478 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) 479 { 480 struct rxrpc_call *call; 481 482 _enter("%p", rx); 483 484 while (!list_empty(&rx->to_be_accepted)) { 485 call = list_entry(rx->to_be_accepted.next, 486 struct rxrpc_call, accept_link); 487 list_del(&call->accept_link); 488 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET); 489 rxrpc_put_call(call, rxrpc_call_put); 490 } 491 492 while (!list_empty(&rx->sock_calls)) { 493 call = list_entry(rx->sock_calls.next, 494 struct rxrpc_call, sock_link); 495 rxrpc_get_call(call, rxrpc_call_got); 496 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET); 497 rxrpc_send_abort_packet(call); 498 rxrpc_release_call(rx, call); 499 rxrpc_put_call(call, rxrpc_call_put); 500 } 501 502 _leave(""); 503 } 504 505 /* 506 * release a call 507 */ 508 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 509 { 510 struct rxrpc_net *rxnet; 511 const void *here = __builtin_return_address(0); 512 int n; 513 514 ASSERT(call != NULL); 515 516 n = atomic_dec_return(&call->usage); 517 trace_rxrpc_call(call, op, n, here, NULL); 518 ASSERTCMP(n, >=, 0); 519 if (n == 0) { 520 _debug("call %d dead", call->debug_id); 521 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 522 523 if (!list_empty(&call->link)) { 524 rxnet = rxrpc_net(sock_net(&call->socket->sk)); 525 write_lock(&rxnet->call_lock); 526 list_del_init(&call->link); 527 write_unlock(&rxnet->call_lock); 528 } 529 530 rxrpc_cleanup_call(call); 531 } 532 } 533 534 /* 535 * Final call destruction under RCU. 536 */ 537 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) 538 { 539 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); 540 541 rxrpc_put_peer(call->peer); 542 kfree(call->rxtx_buffer); 543 kfree(call->rxtx_annotations); 544 kmem_cache_free(rxrpc_call_jar, call); 545 } 546 547 /* 548 * clean up a call 549 */ 550 void rxrpc_cleanup_call(struct rxrpc_call *call) 551 { 552 int i; 553 554 _net("DESTROY CALL %d", call->debug_id); 555 556 memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); 557 558 del_timer_sync(&call->timer); 559 560 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 561 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); 562 ASSERTCMP(call->conn, ==, NULL); 563 564 /* Clean up the Rx/Tx buffer */ 565 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) 566 rxrpc_free_skb(call->rxtx_buffer[i], 567 (call->tx_phase ? rxrpc_skb_tx_cleaned : 568 rxrpc_skb_rx_cleaned)); 569 570 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned); 571 572 call_rcu(&call->rcu, rxrpc_rcu_destroy_call); 573 } 574 575 /* 576 * Make sure that all calls are gone from a network namespace. To reach this 577 * point, any open UDP sockets in that namespace must have been closed, so any 578 * outstanding calls cannot be doing I/O. 579 */ 580 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet) 581 { 582 struct rxrpc_call *call; 583 584 _enter(""); 585 586 if (list_empty(&rxnet->calls)) 587 return; 588 589 write_lock(&rxnet->call_lock); 590 591 while (!list_empty(&rxnet->calls)) { 592 call = list_entry(rxnet->calls.next, struct rxrpc_call, link); 593 _debug("Zapping call %p", call); 594 595 rxrpc_see_call(call); 596 list_del_init(&call->link); 597 598 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", 599 call, atomic_read(&call->usage), 600 rxrpc_call_states[call->state], 601 call->flags, call->events); 602 603 write_unlock(&rxnet->call_lock); 604 cond_resched(); 605 write_lock(&rxnet->call_lock); 606 } 607 608 write_unlock(&rxnet->call_lock); 609 } 610