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 const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = { 47 [rxrpc_call_new_client] = "NWc", 48 [rxrpc_call_new_service] = "NWs", 49 [rxrpc_call_queued] = "QUE", 50 [rxrpc_call_queued_ref] = "QUR", 51 [rxrpc_call_connected] = "CON", 52 [rxrpc_call_release] = "RLS", 53 [rxrpc_call_seen] = "SEE", 54 [rxrpc_call_got] = "GOT", 55 [rxrpc_call_got_userid] = "Gus", 56 [rxrpc_call_got_kernel] = "Gke", 57 [rxrpc_call_put] = "PUT", 58 [rxrpc_call_put_userid] = "Pus", 59 [rxrpc_call_put_kernel] = "Pke", 60 [rxrpc_call_put_noqueue] = "PNQ", 61 [rxrpc_call_error] = "*E*", 62 }; 63 64 struct kmem_cache *rxrpc_call_jar; 65 LIST_HEAD(rxrpc_calls); 66 DEFINE_RWLOCK(rxrpc_call_lock); 67 68 static void rxrpc_call_timer_expired(unsigned long _call) 69 { 70 struct rxrpc_call *call = (struct rxrpc_call *)_call; 71 72 _enter("%d", call->debug_id); 73 74 if (call->state < RXRPC_CALL_COMPLETE) 75 rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real()); 76 } 77 78 /* 79 * find an extant server call 80 * - called in process context with IRQs enabled 81 */ 82 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx, 83 unsigned long user_call_ID) 84 { 85 struct rxrpc_call *call; 86 struct rb_node *p; 87 88 _enter("%p,%lx", rx, user_call_ID); 89 90 read_lock(&rx->call_lock); 91 92 p = rx->calls.rb_node; 93 while (p) { 94 call = rb_entry(p, struct rxrpc_call, sock_node); 95 96 if (user_call_ID < call->user_call_ID) 97 p = p->rb_left; 98 else if (user_call_ID > call->user_call_ID) 99 p = p->rb_right; 100 else 101 goto found_extant_call; 102 } 103 104 read_unlock(&rx->call_lock); 105 _leave(" = NULL"); 106 return NULL; 107 108 found_extant_call: 109 rxrpc_get_call(call, rxrpc_call_got); 110 read_unlock(&rx->call_lock); 111 _leave(" = %p [%d]", call, atomic_read(&call->usage)); 112 return call; 113 } 114 115 /* 116 * allocate a new call 117 */ 118 struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp) 119 { 120 struct rxrpc_call *call; 121 122 call = kmem_cache_zalloc(rxrpc_call_jar, gfp); 123 if (!call) 124 return NULL; 125 126 call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE, 127 sizeof(struct sk_buff *), 128 gfp); 129 if (!call->rxtx_buffer) 130 goto nomem; 131 132 call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp); 133 if (!call->rxtx_annotations) 134 goto nomem_2; 135 136 setup_timer(&call->timer, rxrpc_call_timer_expired, 137 (unsigned long)call); 138 INIT_WORK(&call->processor, &rxrpc_process_call); 139 INIT_LIST_HEAD(&call->link); 140 INIT_LIST_HEAD(&call->chan_wait_link); 141 INIT_LIST_HEAD(&call->accept_link); 142 INIT_LIST_HEAD(&call->recvmsg_link); 143 INIT_LIST_HEAD(&call->sock_link); 144 init_waitqueue_head(&call->waitq); 145 spin_lock_init(&call->lock); 146 rwlock_init(&call->state_lock); 147 atomic_set(&call->usage, 1); 148 call->debug_id = atomic_inc_return(&rxrpc_debug_id); 149 150 memset(&call->sock_node, 0xed, sizeof(call->sock_node)); 151 152 /* Leave space in the ring to handle a maxed-out jumbo packet */ 153 call->rx_winsize = rxrpc_rx_window_size; 154 call->tx_winsize = 16; 155 call->rx_expect_next = 1; 156 157 if (RXRPC_TX_SMSS > 2190) 158 call->cong_cwnd = 2; 159 else if (RXRPC_TX_SMSS > 1095) 160 call->cong_cwnd = 3; 161 else 162 call->cong_cwnd = 4; 163 call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1; 164 return call; 165 166 nomem_2: 167 kfree(call->rxtx_buffer); 168 nomem: 169 kmem_cache_free(rxrpc_call_jar, call); 170 return NULL; 171 } 172 173 /* 174 * Allocate a new client call. 175 */ 176 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, 177 gfp_t gfp) 178 { 179 struct rxrpc_call *call; 180 ktime_t now; 181 182 _enter(""); 183 184 call = rxrpc_alloc_call(gfp); 185 if (!call) 186 return ERR_PTR(-ENOMEM); 187 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; 188 call->service_id = srx->srx_service; 189 call->tx_phase = true; 190 now = ktime_get_real(); 191 call->acks_latest_ts = now; 192 call->cong_tstamp = now; 193 194 _leave(" = %p", call); 195 return call; 196 } 197 198 /* 199 * Initiate the call ack/resend/expiry timer. 200 */ 201 static void rxrpc_start_call_timer(struct rxrpc_call *call) 202 { 203 ktime_t now = ktime_get_real(), expire_at; 204 205 expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime); 206 call->expire_at = expire_at; 207 call->ack_at = expire_at; 208 call->resend_at = expire_at; 209 call->timer.expires = jiffies + LONG_MAX / 2; 210 rxrpc_set_timer(call, rxrpc_timer_begin, now); 211 } 212 213 /* 214 * set up a call for the given data 215 * - called in process context with IRQs enabled 216 */ 217 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, 218 struct rxrpc_conn_parameters *cp, 219 struct sockaddr_rxrpc *srx, 220 unsigned long user_call_ID, 221 gfp_t gfp) 222 { 223 struct rxrpc_call *call, *xcall; 224 struct rb_node *parent, **pp; 225 const void *here = __builtin_return_address(0); 226 int ret; 227 228 _enter("%p,%lx", rx, user_call_ID); 229 230 call = rxrpc_alloc_client_call(srx, gfp); 231 if (IS_ERR(call)) { 232 _leave(" = %ld", PTR_ERR(call)); 233 return call; 234 } 235 236 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), 237 here, (const void *)user_call_ID); 238 239 /* Publish the call, even though it is incompletely set up as yet */ 240 write_lock(&rx->call_lock); 241 242 pp = &rx->calls.rb_node; 243 parent = NULL; 244 while (*pp) { 245 parent = *pp; 246 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 247 248 if (user_call_ID < xcall->user_call_ID) 249 pp = &(*pp)->rb_left; 250 else if (user_call_ID > xcall->user_call_ID) 251 pp = &(*pp)->rb_right; 252 else 253 goto error_dup_user_ID; 254 } 255 256 rcu_assign_pointer(call->socket, rx); 257 call->user_call_ID = user_call_ID; 258 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 259 rxrpc_get_call(call, rxrpc_call_got_userid); 260 rb_link_node(&call->sock_node, parent, pp); 261 rb_insert_color(&call->sock_node, &rx->calls); 262 list_add(&call->sock_link, &rx->sock_calls); 263 264 write_unlock(&rx->call_lock); 265 266 write_lock(&rxrpc_call_lock); 267 list_add_tail(&call->link, &rxrpc_calls); 268 write_unlock(&rxrpc_call_lock); 269 270 /* Set up or get a connection record and set the protocol parameters, 271 * including channel number and call ID. 272 */ 273 ret = rxrpc_connect_call(call, cp, srx, gfp); 274 if (ret < 0) 275 goto error; 276 277 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage), 278 here, ERR_PTR(ret)); 279 280 spin_lock_bh(&call->conn->params.peer->lock); 281 hlist_add_head(&call->error_link, 282 &call->conn->params.peer->error_targets); 283 spin_unlock_bh(&call->conn->params.peer->lock); 284 285 rxrpc_start_call_timer(call); 286 287 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); 288 289 _leave(" = %p [new]", call); 290 return call; 291 292 /* We unexpectedly found the user ID in the list after taking 293 * the call_lock. This shouldn't happen unless the user races 294 * with itself and tries to add the same user ID twice at the 295 * same time in different threads. 296 */ 297 error_dup_user_ID: 298 write_unlock(&rx->call_lock); 299 ret = -EEXIST; 300 301 error: 302 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 303 RX_CALL_DEAD, ret); 304 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage), 305 here, ERR_PTR(ret)); 306 rxrpc_release_call(rx, call); 307 rxrpc_put_call(call, rxrpc_call_put); 308 _leave(" = %d", ret); 309 return ERR_PTR(ret); 310 } 311 312 /* 313 * Set up an incoming call. call->conn points to the connection. 314 * This is called in BH context and isn't allowed to fail. 315 */ 316 void rxrpc_incoming_call(struct rxrpc_sock *rx, 317 struct rxrpc_call *call, 318 struct sk_buff *skb) 319 { 320 struct rxrpc_connection *conn = call->conn; 321 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 322 u32 chan; 323 324 _enter(",%d", call->conn->debug_id); 325 326 rcu_assign_pointer(call->socket, rx); 327 call->call_id = sp->hdr.callNumber; 328 call->service_id = sp->hdr.serviceId; 329 call->cid = sp->hdr.cid; 330 call->state = RXRPC_CALL_SERVER_ACCEPTING; 331 if (sp->hdr.securityIndex > 0) 332 call->state = RXRPC_CALL_SERVER_SECURING; 333 call->cong_tstamp = skb->tstamp; 334 335 /* Set the channel for this call. We don't get channel_lock as we're 336 * only defending against the data_ready handler (which we're called 337 * from) and the RESPONSE packet parser (which is only really 338 * interested in call_counter and can cope with a disagreement with the 339 * call pointer). 340 */ 341 chan = sp->hdr.cid & RXRPC_CHANNELMASK; 342 conn->channels[chan].call_counter = call->call_id; 343 conn->channels[chan].call_id = call->call_id; 344 rcu_assign_pointer(conn->channels[chan].call, call); 345 346 spin_lock(&conn->params.peer->lock); 347 hlist_add_head(&call->error_link, &conn->params.peer->error_targets); 348 spin_unlock(&conn->params.peer->lock); 349 350 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); 351 352 rxrpc_start_call_timer(call); 353 _leave(""); 354 } 355 356 /* 357 * Queue a call's work processor, getting a ref to pass to the work queue. 358 */ 359 bool rxrpc_queue_call(struct rxrpc_call *call) 360 { 361 const void *here = __builtin_return_address(0); 362 int n = __atomic_add_unless(&call->usage, 1, 0); 363 if (n == 0) 364 return false; 365 if (rxrpc_queue_work(&call->processor)) 366 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); 367 else 368 rxrpc_put_call(call, rxrpc_call_put_noqueue); 369 return true; 370 } 371 372 /* 373 * Queue a call's work processor, passing the callers ref to the work queue. 374 */ 375 bool __rxrpc_queue_call(struct rxrpc_call *call) 376 { 377 const void *here = __builtin_return_address(0); 378 int n = atomic_read(&call->usage); 379 ASSERTCMP(n, >=, 1); 380 if (rxrpc_queue_work(&call->processor)) 381 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); 382 else 383 rxrpc_put_call(call, rxrpc_call_put_noqueue); 384 return true; 385 } 386 387 /* 388 * Note the re-emergence of a call. 389 */ 390 void rxrpc_see_call(struct rxrpc_call *call) 391 { 392 const void *here = __builtin_return_address(0); 393 if (call) { 394 int n = atomic_read(&call->usage); 395 396 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); 397 } 398 } 399 400 /* 401 * Note the addition of a ref on a call. 402 */ 403 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 404 { 405 const void *here = __builtin_return_address(0); 406 int n = atomic_inc_return(&call->usage); 407 408 trace_rxrpc_call(call, op, n, here, NULL); 409 } 410 411 /* 412 * Detach a call from its owning socket. 413 */ 414 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) 415 { 416 const void *here = __builtin_return_address(0); 417 struct rxrpc_connection *conn = call->conn; 418 bool put = false; 419 int i; 420 421 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); 422 423 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage), 424 here, (const void *)call->flags); 425 426 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 427 428 spin_lock_bh(&call->lock); 429 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) 430 BUG(); 431 spin_unlock_bh(&call->lock); 432 433 del_timer_sync(&call->timer); 434 435 /* Make sure we don't get any more notifications */ 436 write_lock_bh(&rx->recvmsg_lock); 437 438 if (!list_empty(&call->recvmsg_link)) { 439 _debug("unlinking once-pending call %p { e=%lx f=%lx }", 440 call, call->events, call->flags); 441 list_del(&call->recvmsg_link); 442 put = true; 443 } 444 445 /* list_empty() must return false in rxrpc_notify_socket() */ 446 call->recvmsg_link.next = NULL; 447 call->recvmsg_link.prev = NULL; 448 449 write_unlock_bh(&rx->recvmsg_lock); 450 if (put) 451 rxrpc_put_call(call, rxrpc_call_put); 452 453 write_lock(&rx->call_lock); 454 455 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 456 rb_erase(&call->sock_node, &rx->calls); 457 memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); 458 rxrpc_put_call(call, rxrpc_call_put_userid); 459 } 460 461 list_del(&call->sock_link); 462 write_unlock(&rx->call_lock); 463 464 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); 465 466 if (conn) 467 rxrpc_disconnect_call(call); 468 469 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { 470 rxrpc_free_skb(call->rxtx_buffer[i], 471 (call->tx_phase ? rxrpc_skb_tx_cleaned : 472 rxrpc_skb_rx_cleaned)); 473 call->rxtx_buffer[i] = NULL; 474 } 475 476 _leave(""); 477 } 478 479 /* 480 * release all the calls associated with a socket 481 */ 482 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) 483 { 484 struct rxrpc_call *call; 485 486 _enter("%p", rx); 487 488 while (!list_empty(&rx->to_be_accepted)) { 489 call = list_entry(rx->to_be_accepted.next, 490 struct rxrpc_call, accept_link); 491 list_del(&call->accept_link); 492 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, ECONNRESET); 493 rxrpc_put_call(call, rxrpc_call_put); 494 } 495 496 while (!list_empty(&rx->sock_calls)) { 497 call = list_entry(rx->sock_calls.next, 498 struct rxrpc_call, sock_link); 499 rxrpc_get_call(call, rxrpc_call_got); 500 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET); 501 rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT); 502 rxrpc_release_call(rx, call); 503 rxrpc_put_call(call, rxrpc_call_put); 504 } 505 506 _leave(""); 507 } 508 509 /* 510 * release a call 511 */ 512 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 513 { 514 const void *here = __builtin_return_address(0); 515 int n; 516 517 ASSERT(call != NULL); 518 519 n = atomic_dec_return(&call->usage); 520 trace_rxrpc_call(call, op, n, here, NULL); 521 ASSERTCMP(n, >=, 0); 522 if (n == 0) { 523 _debug("call %d dead", call->debug_id); 524 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 525 526 write_lock(&rxrpc_call_lock); 527 list_del_init(&call->link); 528 write_unlock(&rxrpc_call_lock); 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. 577 */ 578 void __exit rxrpc_destroy_all_calls(void) 579 { 580 struct rxrpc_call *call; 581 582 _enter(""); 583 584 if (list_empty(&rxrpc_calls)) 585 return; 586 587 write_lock(&rxrpc_call_lock); 588 589 while (!list_empty(&rxrpc_calls)) { 590 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link); 591 _debug("Zapping call %p", call); 592 593 rxrpc_see_call(call); 594 list_del_init(&call->link); 595 596 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", 597 call, atomic_read(&call->usage), 598 rxrpc_call_states[call->state], 599 call->flags, call->events); 600 601 write_unlock(&rxrpc_call_lock); 602 cond_resched(); 603 write_lock(&rxrpc_call_lock); 604 } 605 606 write_unlock(&rxrpc_call_lock); 607 } 608