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