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 LIST_HEAD(rxrpc_calls); 48 DEFINE_RWLOCK(rxrpc_call_lock); 49 50 static void rxrpc_call_timer_expired(unsigned long _call) 51 { 52 struct rxrpc_call *call = (struct rxrpc_call *)_call; 53 54 _enter("%d", call->debug_id); 55 56 if (call->state < RXRPC_CALL_COMPLETE) 57 rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real()); 58 } 59 60 /* 61 * find an extant server call 62 * - called in process context with IRQs enabled 63 */ 64 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx, 65 unsigned long user_call_ID) 66 { 67 struct rxrpc_call *call; 68 struct rb_node *p; 69 70 _enter("%p,%lx", rx, user_call_ID); 71 72 read_lock(&rx->call_lock); 73 74 p = rx->calls.rb_node; 75 while (p) { 76 call = rb_entry(p, struct rxrpc_call, sock_node); 77 78 if (user_call_ID < call->user_call_ID) 79 p = p->rb_left; 80 else if (user_call_ID > call->user_call_ID) 81 p = p->rb_right; 82 else 83 goto found_extant_call; 84 } 85 86 read_unlock(&rx->call_lock); 87 _leave(" = NULL"); 88 return NULL; 89 90 found_extant_call: 91 rxrpc_get_call(call, rxrpc_call_got); 92 read_unlock(&rx->call_lock); 93 _leave(" = %p [%d]", call, atomic_read(&call->usage)); 94 return call; 95 } 96 97 /* 98 * allocate a new call 99 */ 100 struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) 101 { 102 struct rxrpc_call *call; 103 104 call = kmem_cache_zalloc(rxrpc_call_jar, gfp); 105 if (!call) 106 return NULL; 107 108 call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE, 109 sizeof(struct sk_buff *), 110 gfp); 111 if (!call->rxtx_buffer) 112 goto nomem; 113 114 call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp); 115 if (!call->rxtx_annotations) 116 goto nomem_2; 117 118 mutex_init(&call->user_mutex); 119 setup_timer(&call->timer, rxrpc_call_timer_expired, 120 (unsigned long)call); 121 INIT_WORK(&call->processor, &rxrpc_process_call); 122 INIT_LIST_HEAD(&call->link); 123 INIT_LIST_HEAD(&call->chan_wait_link); 124 INIT_LIST_HEAD(&call->accept_link); 125 INIT_LIST_HEAD(&call->recvmsg_link); 126 INIT_LIST_HEAD(&call->sock_link); 127 init_waitqueue_head(&call->waitq); 128 spin_lock_init(&call->lock); 129 rwlock_init(&call->state_lock); 130 atomic_set(&call->usage, 1); 131 call->debug_id = atomic_inc_return(&rxrpc_debug_id); 132 133 memset(&call->sock_node, 0xed, sizeof(call->sock_node)); 134 135 /* Leave space in the ring to handle a maxed-out jumbo packet */ 136 call->rx_winsize = rxrpc_rx_window_size; 137 call->tx_winsize = 16; 138 call->rx_expect_next = 1; 139 140 if (RXRPC_TX_SMSS > 2190) 141 call->cong_cwnd = 2; 142 else if (RXRPC_TX_SMSS > 1095) 143 call->cong_cwnd = 3; 144 else 145 call->cong_cwnd = 4; 146 call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1; 147 return call; 148 149 nomem_2: 150 kfree(call->rxtx_buffer); 151 nomem: 152 kmem_cache_free(rxrpc_call_jar, call); 153 return NULL; 154 } 155 156 /* 157 * Allocate a new client call. 158 */ 159 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, 160 gfp_t gfp) 161 { 162 struct rxrpc_call *call; 163 ktime_t now; 164 165 _enter(""); 166 167 call = rxrpc_alloc_call(gfp); 168 if (!call) 169 return ERR_PTR(-ENOMEM); 170 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; 171 call->service_id = srx->srx_service; 172 call->tx_phase = true; 173 now = ktime_get_real(); 174 call->acks_latest_ts = now; 175 call->cong_tstamp = now; 176 177 _leave(" = %p", call); 178 return call; 179 } 180 181 /* 182 * Initiate the call ack/resend/expiry timer. 183 */ 184 static void rxrpc_start_call_timer(struct rxrpc_call *call) 185 { 186 ktime_t now = ktime_get_real(), expire_at; 187 188 expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime); 189 call->expire_at = expire_at; 190 call->ack_at = expire_at; 191 call->ping_at = expire_at; 192 call->resend_at = expire_at; 193 call->timer.expires = jiffies + LONG_MAX / 2; 194 rxrpc_set_timer(call, rxrpc_timer_begin, now); 195 } 196 197 /* 198 * Set up a call for the given parameters. 199 * - Called with the socket lock held, which it must release. 200 * - If it returns a call, the call's lock will need releasing by the caller. 201 */ 202 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, 203 struct rxrpc_conn_parameters *cp, 204 struct sockaddr_rxrpc *srx, 205 unsigned long user_call_ID, 206 gfp_t gfp) 207 __releases(&rx->sk.sk_lock.slock) 208 { 209 struct rxrpc_call *call, *xcall; 210 struct rb_node *parent, **pp; 211 const void *here = __builtin_return_address(0); 212 int ret; 213 214 _enter("%p,%lx", rx, user_call_ID); 215 216 call = rxrpc_alloc_client_call(srx, gfp); 217 if (IS_ERR(call)) { 218 release_sock(&rx->sk); 219 _leave(" = %ld", PTR_ERR(call)); 220 return call; 221 } 222 223 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), 224 here, (const void *)user_call_ID); 225 226 /* We need to protect a partially set up call against the user as we 227 * will be acting outside the socket lock. 228 */ 229 mutex_lock(&call->user_mutex); 230 231 /* Publish the call, even though it is incompletely set up as yet */ 232 write_lock(&rx->call_lock); 233 234 pp = &rx->calls.rb_node; 235 parent = NULL; 236 while (*pp) { 237 parent = *pp; 238 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 239 240 if (user_call_ID < xcall->user_call_ID) 241 pp = &(*pp)->rb_left; 242 else if (user_call_ID > xcall->user_call_ID) 243 pp = &(*pp)->rb_right; 244 else 245 goto error_dup_user_ID; 246 } 247 248 rcu_assign_pointer(call->socket, rx); 249 call->user_call_ID = user_call_ID; 250 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 251 rxrpc_get_call(call, rxrpc_call_got_userid); 252 rb_link_node(&call->sock_node, parent, pp); 253 rb_insert_color(&call->sock_node, &rx->calls); 254 list_add(&call->sock_link, &rx->sock_calls); 255 256 write_unlock(&rx->call_lock); 257 258 write_lock(&rxrpc_call_lock); 259 list_add_tail(&call->link, &rxrpc_calls); 260 write_unlock(&rxrpc_call_lock); 261 262 /* From this point on, the call is protected by its own lock. */ 263 release_sock(&rx->sk); 264 265 /* Set up or get a connection record and set the protocol parameters, 266 * including channel number and call ID. 267 */ 268 ret = rxrpc_connect_call(call, cp, srx, gfp); 269 if (ret < 0) 270 goto error; 271 272 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage), 273 here, NULL); 274 275 spin_lock_bh(&call->conn->params.peer->lock); 276 hlist_add_head(&call->error_link, 277 &call->conn->params.peer->error_targets); 278 spin_unlock_bh(&call->conn->params.peer->lock); 279 280 rxrpc_start_call_timer(call); 281 282 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); 283 284 _leave(" = %p [new]", call); 285 return call; 286 287 /* We unexpectedly found the user ID in the list after taking 288 * the call_lock. This shouldn't happen unless the user races 289 * with itself and tries to add the same user ID twice at the 290 * same time in different threads. 291 */ 292 error_dup_user_ID: 293 write_unlock(&rx->call_lock); 294 release_sock(&rx->sk); 295 ret = -EEXIST; 296 297 error: 298 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 299 RX_CALL_DEAD, ret); 300 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage), 301 here, ERR_PTR(ret)); 302 rxrpc_release_call(rx, call); 303 mutex_unlock(&call->user_mutex); 304 rxrpc_put_call(call, rxrpc_call_put); 305 _leave(" = %d", ret); 306 return ERR_PTR(ret); 307 } 308 309 /* 310 * Set up an incoming call. call->conn points to the connection. 311 * This is called in BH context and isn't allowed to fail. 312 */ 313 void rxrpc_incoming_call(struct rxrpc_sock *rx, 314 struct rxrpc_call *call, 315 struct sk_buff *skb) 316 { 317 struct rxrpc_connection *conn = call->conn; 318 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 319 u32 chan; 320 321 _enter(",%d", call->conn->debug_id); 322 323 rcu_assign_pointer(call->socket, rx); 324 call->call_id = sp->hdr.callNumber; 325 call->service_id = sp->hdr.serviceId; 326 call->cid = sp->hdr.cid; 327 call->state = RXRPC_CALL_SERVER_ACCEPTING; 328 if (sp->hdr.securityIndex > 0) 329 call->state = RXRPC_CALL_SERVER_SECURING; 330 call->cong_tstamp = skb->tstamp; 331 332 /* Set the channel for this call. We don't get channel_lock as we're 333 * only defending against the data_ready handler (which we're called 334 * from) and the RESPONSE packet parser (which is only really 335 * interested in call_counter and can cope with a disagreement with the 336 * call pointer). 337 */ 338 chan = sp->hdr.cid & RXRPC_CHANNELMASK; 339 conn->channels[chan].call_counter = call->call_id; 340 conn->channels[chan].call_id = call->call_id; 341 rcu_assign_pointer(conn->channels[chan].call, call); 342 343 spin_lock(&conn->params.peer->lock); 344 hlist_add_head(&call->error_link, &conn->params.peer->error_targets); 345 spin_unlock(&conn->params.peer->lock); 346 347 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); 348 349 rxrpc_start_call_timer(call); 350 _leave(""); 351 } 352 353 /* 354 * Queue a call's work processor, getting a ref to pass to the work queue. 355 */ 356 bool rxrpc_queue_call(struct rxrpc_call *call) 357 { 358 const void *here = __builtin_return_address(0); 359 int n = __atomic_add_unless(&call->usage, 1, 0); 360 if (n == 0) 361 return false; 362 if (rxrpc_queue_work(&call->processor)) 363 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); 364 else 365 rxrpc_put_call(call, rxrpc_call_put_noqueue); 366 return true; 367 } 368 369 /* 370 * Queue a call's work processor, passing the callers ref to the work queue. 371 */ 372 bool __rxrpc_queue_call(struct rxrpc_call *call) 373 { 374 const void *here = __builtin_return_address(0); 375 int n = atomic_read(&call->usage); 376 ASSERTCMP(n, >=, 1); 377 if (rxrpc_queue_work(&call->processor)) 378 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); 379 else 380 rxrpc_put_call(call, rxrpc_call_put_noqueue); 381 return true; 382 } 383 384 /* 385 * Note the re-emergence of a call. 386 */ 387 void rxrpc_see_call(struct rxrpc_call *call) 388 { 389 const void *here = __builtin_return_address(0); 390 if (call) { 391 int n = atomic_read(&call->usage); 392 393 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); 394 } 395 } 396 397 /* 398 * Note the addition of a ref on a call. 399 */ 400 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 401 { 402 const void *here = __builtin_return_address(0); 403 int n = atomic_inc_return(&call->usage); 404 405 trace_rxrpc_call(call, op, n, here, NULL); 406 } 407 408 /* 409 * Detach a call from its owning socket. 410 */ 411 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) 412 { 413 const void *here = __builtin_return_address(0); 414 struct rxrpc_connection *conn = call->conn; 415 bool put = false; 416 int i; 417 418 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); 419 420 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage), 421 here, (const void *)call->flags); 422 423 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 424 425 spin_lock_bh(&call->lock); 426 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) 427 BUG(); 428 spin_unlock_bh(&call->lock); 429 430 del_timer_sync(&call->timer); 431 432 /* Make sure we don't get any more notifications */ 433 write_lock_bh(&rx->recvmsg_lock); 434 435 if (!list_empty(&call->recvmsg_link)) { 436 _debug("unlinking once-pending call %p { e=%lx f=%lx }", 437 call, call->events, call->flags); 438 list_del(&call->recvmsg_link); 439 put = true; 440 } 441 442 /* list_empty() must return false in rxrpc_notify_socket() */ 443 call->recvmsg_link.next = NULL; 444 call->recvmsg_link.prev = NULL; 445 446 write_unlock_bh(&rx->recvmsg_lock); 447 if (put) 448 rxrpc_put_call(call, rxrpc_call_put); 449 450 write_lock(&rx->call_lock); 451 452 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 453 rb_erase(&call->sock_node, &rx->calls); 454 memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); 455 rxrpc_put_call(call, rxrpc_call_put_userid); 456 } 457 458 list_del(&call->sock_link); 459 write_unlock(&rx->call_lock); 460 461 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); 462 463 if (conn) 464 rxrpc_disconnect_call(call); 465 466 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { 467 rxrpc_free_skb(call->rxtx_buffer[i], 468 (call->tx_phase ? rxrpc_skb_tx_cleaned : 469 rxrpc_skb_rx_cleaned)); 470 call->rxtx_buffer[i] = NULL; 471 } 472 473 _leave(""); 474 } 475 476 /* 477 * release all the calls associated with a socket 478 */ 479 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) 480 { 481 struct rxrpc_call *call; 482 483 _enter("%p", rx); 484 485 while (!list_empty(&rx->to_be_accepted)) { 486 call = list_entry(rx->to_be_accepted.next, 487 struct rxrpc_call, accept_link); 488 list_del(&call->accept_link); 489 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET); 490 rxrpc_put_call(call, rxrpc_call_put); 491 } 492 493 while (!list_empty(&rx->sock_calls)) { 494 call = list_entry(rx->sock_calls.next, 495 struct rxrpc_call, sock_link); 496 rxrpc_get_call(call, rxrpc_call_got); 497 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET); 498 rxrpc_send_abort_packet(call); 499 rxrpc_release_call(rx, call); 500 rxrpc_put_call(call, rxrpc_call_put); 501 } 502 503 _leave(""); 504 } 505 506 /* 507 * release a call 508 */ 509 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 510 { 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 write_lock(&rxrpc_call_lock); 524 list_del_init(&call->link); 525 write_unlock(&rxrpc_call_lock); 526 527 rxrpc_cleanup_call(call); 528 } 529 } 530 531 /* 532 * Final call destruction under RCU. 533 */ 534 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) 535 { 536 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); 537 538 rxrpc_put_peer(call->peer); 539 kfree(call->rxtx_buffer); 540 kfree(call->rxtx_annotations); 541 kmem_cache_free(rxrpc_call_jar, call); 542 } 543 544 /* 545 * clean up a call 546 */ 547 void rxrpc_cleanup_call(struct rxrpc_call *call) 548 { 549 int i; 550 551 _net("DESTROY CALL %d", call->debug_id); 552 553 memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); 554 555 del_timer_sync(&call->timer); 556 557 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 558 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); 559 ASSERTCMP(call->conn, ==, NULL); 560 561 /* Clean up the Rx/Tx buffer */ 562 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) 563 rxrpc_free_skb(call->rxtx_buffer[i], 564 (call->tx_phase ? rxrpc_skb_tx_cleaned : 565 rxrpc_skb_rx_cleaned)); 566 567 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned); 568 569 call_rcu(&call->rcu, rxrpc_rcu_destroy_call); 570 } 571 572 /* 573 * Make sure that all calls are gone. 574 */ 575 void __exit rxrpc_destroy_all_calls(void) 576 { 577 struct rxrpc_call *call; 578 579 _enter(""); 580 581 if (list_empty(&rxrpc_calls)) 582 return; 583 584 write_lock(&rxrpc_call_lock); 585 586 while (!list_empty(&rxrpc_calls)) { 587 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link); 588 _debug("Zapping call %p", call); 589 590 rxrpc_see_call(call); 591 list_del_init(&call->link); 592 593 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", 594 call, atomic_read(&call->usage), 595 rxrpc_call_states[call->state], 596 call->flags, call->events); 597 598 write_unlock(&rxrpc_call_lock); 599 cond_resched(); 600 write_lock(&rxrpc_call_lock); 601 } 602 603 write_unlock(&rxrpc_call_lock); 604 } 605