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->ping_at = expire_at; 209 call->resend_at = expire_at; 210 call->timer.expires = jiffies + LONG_MAX / 2; 211 rxrpc_set_timer(call, rxrpc_timer_begin, now); 212 } 213 214 /* 215 * set up a call for the given data 216 * - called in process context with IRQs enabled 217 */ 218 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, 219 struct rxrpc_conn_parameters *cp, 220 struct sockaddr_rxrpc *srx, 221 unsigned long user_call_ID, 222 gfp_t gfp) 223 { 224 struct rxrpc_call *call, *xcall; 225 struct rb_node *parent, **pp; 226 const void *here = __builtin_return_address(0); 227 int ret; 228 229 _enter("%p,%lx", rx, user_call_ID); 230 231 call = rxrpc_alloc_client_call(srx, gfp); 232 if (IS_ERR(call)) { 233 _leave(" = %ld", PTR_ERR(call)); 234 return call; 235 } 236 237 trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage), 238 here, (const void *)user_call_ID); 239 240 /* Publish the call, even though it is incompletely set up as yet */ 241 write_lock(&rx->call_lock); 242 243 pp = &rx->calls.rb_node; 244 parent = NULL; 245 while (*pp) { 246 parent = *pp; 247 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 248 249 if (user_call_ID < xcall->user_call_ID) 250 pp = &(*pp)->rb_left; 251 else if (user_call_ID > xcall->user_call_ID) 252 pp = &(*pp)->rb_right; 253 else 254 goto error_dup_user_ID; 255 } 256 257 rcu_assign_pointer(call->socket, rx); 258 call->user_call_ID = user_call_ID; 259 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 260 rxrpc_get_call(call, rxrpc_call_got_userid); 261 rb_link_node(&call->sock_node, parent, pp); 262 rb_insert_color(&call->sock_node, &rx->calls); 263 list_add(&call->sock_link, &rx->sock_calls); 264 265 write_unlock(&rx->call_lock); 266 267 write_lock(&rxrpc_call_lock); 268 list_add_tail(&call->link, &rxrpc_calls); 269 write_unlock(&rxrpc_call_lock); 270 271 /* Set up or get a connection record and set the protocol parameters, 272 * including channel number and call ID. 273 */ 274 ret = rxrpc_connect_call(call, cp, srx, gfp); 275 if (ret < 0) 276 goto error; 277 278 trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage), 279 here, ERR_PTR(ret)); 280 281 spin_lock_bh(&call->conn->params.peer->lock); 282 hlist_add_head(&call->error_link, 283 &call->conn->params.peer->error_targets); 284 spin_unlock_bh(&call->conn->params.peer->lock); 285 286 rxrpc_start_call_timer(call); 287 288 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); 289 290 _leave(" = %p [new]", call); 291 return call; 292 293 /* We unexpectedly found the user ID in the list after taking 294 * the call_lock. This shouldn't happen unless the user races 295 * with itself and tries to add the same user ID twice at the 296 * same time in different threads. 297 */ 298 error_dup_user_ID: 299 write_unlock(&rx->call_lock); 300 ret = -EEXIST; 301 302 error: 303 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 304 RX_CALL_DEAD, ret); 305 trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage), 306 here, ERR_PTR(ret)); 307 rxrpc_release_call(rx, call); 308 rxrpc_put_call(call, rxrpc_call_put); 309 _leave(" = %d", ret); 310 return ERR_PTR(ret); 311 } 312 313 /* 314 * Set up an incoming call. call->conn points to the connection. 315 * This is called in BH context and isn't allowed to fail. 316 */ 317 void rxrpc_incoming_call(struct rxrpc_sock *rx, 318 struct rxrpc_call *call, 319 struct sk_buff *skb) 320 { 321 struct rxrpc_connection *conn = call->conn; 322 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 323 u32 chan; 324 325 _enter(",%d", call->conn->debug_id); 326 327 rcu_assign_pointer(call->socket, rx); 328 call->call_id = sp->hdr.callNumber; 329 call->service_id = sp->hdr.serviceId; 330 call->cid = sp->hdr.cid; 331 call->state = RXRPC_CALL_SERVER_ACCEPTING; 332 if (sp->hdr.securityIndex > 0) 333 call->state = RXRPC_CALL_SERVER_SECURING; 334 call->cong_tstamp = skb->tstamp; 335 336 /* Set the channel for this call. We don't get channel_lock as we're 337 * only defending against the data_ready handler (which we're called 338 * from) and the RESPONSE packet parser (which is only really 339 * interested in call_counter and can cope with a disagreement with the 340 * call pointer). 341 */ 342 chan = sp->hdr.cid & RXRPC_CHANNELMASK; 343 conn->channels[chan].call_counter = call->call_id; 344 conn->channels[chan].call_id = call->call_id; 345 rcu_assign_pointer(conn->channels[chan].call, call); 346 347 spin_lock(&conn->params.peer->lock); 348 hlist_add_head(&call->error_link, &conn->params.peer->error_targets); 349 spin_unlock(&conn->params.peer->lock); 350 351 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); 352 353 rxrpc_start_call_timer(call); 354 _leave(""); 355 } 356 357 /* 358 * Queue a call's work processor, getting a ref to pass to the work queue. 359 */ 360 bool rxrpc_queue_call(struct rxrpc_call *call) 361 { 362 const void *here = __builtin_return_address(0); 363 int n = __atomic_add_unless(&call->usage, 1, 0); 364 if (n == 0) 365 return false; 366 if (rxrpc_queue_work(&call->processor)) 367 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); 368 else 369 rxrpc_put_call(call, rxrpc_call_put_noqueue); 370 return true; 371 } 372 373 /* 374 * Queue a call's work processor, passing the callers ref to the work queue. 375 */ 376 bool __rxrpc_queue_call(struct rxrpc_call *call) 377 { 378 const void *here = __builtin_return_address(0); 379 int n = atomic_read(&call->usage); 380 ASSERTCMP(n, >=, 1); 381 if (rxrpc_queue_work(&call->processor)) 382 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); 383 else 384 rxrpc_put_call(call, rxrpc_call_put_noqueue); 385 return true; 386 } 387 388 /* 389 * Note the re-emergence of a call. 390 */ 391 void rxrpc_see_call(struct rxrpc_call *call) 392 { 393 const void *here = __builtin_return_address(0); 394 if (call) { 395 int n = atomic_read(&call->usage); 396 397 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); 398 } 399 } 400 401 /* 402 * Note the addition of a ref on a call. 403 */ 404 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 405 { 406 const void *here = __builtin_return_address(0); 407 int n = atomic_inc_return(&call->usage); 408 409 trace_rxrpc_call(call, op, n, here, NULL); 410 } 411 412 /* 413 * Detach a call from its owning socket. 414 */ 415 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) 416 { 417 const void *here = __builtin_return_address(0); 418 struct rxrpc_connection *conn = call->conn; 419 bool put = false; 420 int i; 421 422 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); 423 424 trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage), 425 here, (const void *)call->flags); 426 427 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 428 429 spin_lock_bh(&call->lock); 430 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) 431 BUG(); 432 spin_unlock_bh(&call->lock); 433 434 del_timer_sync(&call->timer); 435 436 /* Make sure we don't get any more notifications */ 437 write_lock_bh(&rx->recvmsg_lock); 438 439 if (!list_empty(&call->recvmsg_link)) { 440 _debug("unlinking once-pending call %p { e=%lx f=%lx }", 441 call, call->events, call->flags); 442 list_del(&call->recvmsg_link); 443 put = true; 444 } 445 446 /* list_empty() must return false in rxrpc_notify_socket() */ 447 call->recvmsg_link.next = NULL; 448 call->recvmsg_link.prev = NULL; 449 450 write_unlock_bh(&rx->recvmsg_lock); 451 if (put) 452 rxrpc_put_call(call, rxrpc_call_put); 453 454 write_lock(&rx->call_lock); 455 456 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 457 rb_erase(&call->sock_node, &rx->calls); 458 memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); 459 rxrpc_put_call(call, rxrpc_call_put_userid); 460 } 461 462 list_del(&call->sock_link); 463 write_unlock(&rx->call_lock); 464 465 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); 466 467 if (conn) 468 rxrpc_disconnect_call(call); 469 470 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { 471 rxrpc_free_skb(call->rxtx_buffer[i], 472 (call->tx_phase ? rxrpc_skb_tx_cleaned : 473 rxrpc_skb_rx_cleaned)); 474 call->rxtx_buffer[i] = NULL; 475 } 476 477 _leave(""); 478 } 479 480 /* 481 * release all the calls associated with a socket 482 */ 483 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) 484 { 485 struct rxrpc_call *call; 486 487 _enter("%p", rx); 488 489 while (!list_empty(&rx->to_be_accepted)) { 490 call = list_entry(rx->to_be_accepted.next, 491 struct rxrpc_call, accept_link); 492 list_del(&call->accept_link); 493 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, ECONNRESET); 494 rxrpc_put_call(call, rxrpc_call_put); 495 } 496 497 while (!list_empty(&rx->sock_calls)) { 498 call = list_entry(rx->sock_calls.next, 499 struct rxrpc_call, sock_link); 500 rxrpc_get_call(call, rxrpc_call_got); 501 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET); 502 rxrpc_send_abort_packet(call); 503 rxrpc_release_call(rx, call); 504 rxrpc_put_call(call, rxrpc_call_put); 505 } 506 507 _leave(""); 508 } 509 510 /* 511 * release a call 512 */ 513 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 514 { 515 const void *here = __builtin_return_address(0); 516 int n; 517 518 ASSERT(call != NULL); 519 520 n = atomic_dec_return(&call->usage); 521 trace_rxrpc_call(call, op, n, here, NULL); 522 ASSERTCMP(n, >=, 0); 523 if (n == 0) { 524 _debug("call %d dead", call->debug_id); 525 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 526 527 write_lock(&rxrpc_call_lock); 528 list_del_init(&call->link); 529 write_unlock(&rxrpc_call_lock); 530 531 rxrpc_cleanup_call(call); 532 } 533 } 534 535 /* 536 * Final call destruction under RCU. 537 */ 538 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) 539 { 540 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); 541 542 rxrpc_put_peer(call->peer); 543 kfree(call->rxtx_buffer); 544 kfree(call->rxtx_annotations); 545 kmem_cache_free(rxrpc_call_jar, call); 546 } 547 548 /* 549 * clean up a call 550 */ 551 void rxrpc_cleanup_call(struct rxrpc_call *call) 552 { 553 int i; 554 555 _net("DESTROY CALL %d", call->debug_id); 556 557 memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); 558 559 del_timer_sync(&call->timer); 560 561 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 562 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); 563 ASSERTCMP(call->conn, ==, NULL); 564 565 /* Clean up the Rx/Tx buffer */ 566 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) 567 rxrpc_free_skb(call->rxtx_buffer[i], 568 (call->tx_phase ? rxrpc_skb_tx_cleaned : 569 rxrpc_skb_rx_cleaned)); 570 571 rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned); 572 573 call_rcu(&call->rcu, rxrpc_rcu_destroy_call); 574 } 575 576 /* 577 * Make sure that all calls are gone. 578 */ 579 void __exit rxrpc_destroy_all_calls(void) 580 { 581 struct rxrpc_call *call; 582 583 _enter(""); 584 585 if (list_empty(&rxrpc_calls)) 586 return; 587 588 write_lock(&rxrpc_call_lock); 589 590 while (!list_empty(&rxrpc_calls)) { 591 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link); 592 _debug("Zapping call %p", call); 593 594 rxrpc_see_call(call); 595 list_del_init(&call->link); 596 597 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", 598 call, atomic_read(&call->usage), 599 rxrpc_call_states[call->state], 600 call->flags, call->events); 601 602 write_unlock(&rxrpc_call_lock); 603 cond_resched(); 604 write_lock(&rxrpc_call_lock); 605 } 606 607 write_unlock(&rxrpc_call_lock); 608 } 609