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 /* 23 * Maximum lifetime of a call (in jiffies). 24 */ 25 unsigned int rxrpc_max_call_lifetime = 60 * HZ; 26 27 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = { 28 [RXRPC_CALL_UNINITIALISED] = "Uninit ", 29 [RXRPC_CALL_CLIENT_AWAIT_CONN] = "ClWtConn", 30 [RXRPC_CALL_CLIENT_SEND_REQUEST] = "ClSndReq", 31 [RXRPC_CALL_CLIENT_AWAIT_REPLY] = "ClAwtRpl", 32 [RXRPC_CALL_CLIENT_RECV_REPLY] = "ClRcvRpl", 33 [RXRPC_CALL_SERVER_PREALLOC] = "SvPrealc", 34 [RXRPC_CALL_SERVER_SECURING] = "SvSecure", 35 [RXRPC_CALL_SERVER_ACCEPTING] = "SvAccept", 36 [RXRPC_CALL_SERVER_RECV_REQUEST] = "SvRcvReq", 37 [RXRPC_CALL_SERVER_ACK_REQUEST] = "SvAckReq", 38 [RXRPC_CALL_SERVER_SEND_REPLY] = "SvSndRpl", 39 [RXRPC_CALL_SERVER_AWAIT_ACK] = "SvAwtACK", 40 [RXRPC_CALL_COMPLETE] = "Complete", 41 }; 42 43 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = { 44 [RXRPC_CALL_SUCCEEDED] = "Complete", 45 [RXRPC_CALL_REMOTELY_ABORTED] = "RmtAbort", 46 [RXRPC_CALL_LOCALLY_ABORTED] = "LocAbort", 47 [RXRPC_CALL_LOCAL_ERROR] = "LocError", 48 [RXRPC_CALL_NETWORK_ERROR] = "NetError", 49 }; 50 51 const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = { 52 [rxrpc_call_new_client] = "NWc", 53 [rxrpc_call_new_service] = "NWs", 54 [rxrpc_call_queued] = "QUE", 55 [rxrpc_call_queued_ref] = "QUR", 56 [rxrpc_call_seen] = "SEE", 57 [rxrpc_call_got] = "GOT", 58 [rxrpc_call_got_userid] = "Gus", 59 [rxrpc_call_put] = "PUT", 60 [rxrpc_call_put_userid] = "Pus", 61 [rxrpc_call_put_noqueue] = "PNQ", 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_queue_call(call); 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_RXTX_BUFF_SIZE - 1 - 46; 154 call->tx_winsize = 16; 155 call->rx_expect_next = 1; 156 return call; 157 158 nomem_2: 159 kfree(call->rxtx_buffer); 160 nomem: 161 kmem_cache_free(rxrpc_call_jar, call); 162 return NULL; 163 } 164 165 /* 166 * Allocate a new client call. 167 */ 168 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx, 169 gfp_t gfp) 170 { 171 struct rxrpc_call *call; 172 173 _enter(""); 174 175 call = rxrpc_alloc_call(gfp); 176 if (!call) 177 return ERR_PTR(-ENOMEM); 178 call->state = RXRPC_CALL_CLIENT_AWAIT_CONN; 179 call->service_id = srx->srx_service; 180 181 _leave(" = %p", call); 182 return call; 183 } 184 185 /* 186 * Initiate the call ack/resend/expiry timer. 187 */ 188 static void rxrpc_start_call_timer(struct rxrpc_call *call) 189 { 190 unsigned long expire_at; 191 192 expire_at = jiffies + rxrpc_max_call_lifetime; 193 call->expire_at = expire_at; 194 call->ack_at = expire_at; 195 call->resend_at = expire_at; 196 call->timer.expires = expire_at; 197 add_timer(&call->timer); 198 } 199 200 /* 201 * set up a call for the given data 202 * - called in process context with IRQs enabled 203 */ 204 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx, 205 struct rxrpc_conn_parameters *cp, 206 struct sockaddr_rxrpc *srx, 207 unsigned long user_call_ID, 208 gfp_t gfp) 209 { 210 struct rxrpc_call *call, *xcall; 211 struct rb_node *parent, **pp; 212 const void *here = __builtin_return_address(0); 213 int ret; 214 215 _enter("%p,%lx", rx, user_call_ID); 216 217 call = rxrpc_alloc_client_call(srx, gfp); 218 if (IS_ERR(call)) { 219 _leave(" = %ld", PTR_ERR(call)); 220 return call; 221 } 222 223 trace_rxrpc_call(call, 0, atomic_read(&call->usage), here, 224 (const void *)user_call_ID); 225 226 /* Publish the call, even though it is incompletely set up as yet */ 227 call->user_call_ID = user_call_ID; 228 __set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 229 230 write_lock(&rx->call_lock); 231 232 pp = &rx->calls.rb_node; 233 parent = NULL; 234 while (*pp) { 235 parent = *pp; 236 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 237 238 if (user_call_ID < xcall->user_call_ID) 239 pp = &(*pp)->rb_left; 240 else if (user_call_ID > xcall->user_call_ID) 241 pp = &(*pp)->rb_right; 242 else 243 goto found_user_ID_now_present; 244 } 245 246 rcu_assign_pointer(call->socket, rx); 247 rxrpc_get_call(call, rxrpc_call_got_userid); 248 rb_link_node(&call->sock_node, parent, pp); 249 rb_insert_color(&call->sock_node, &rx->calls); 250 list_add(&call->sock_link, &rx->sock_calls); 251 252 write_unlock(&rx->call_lock); 253 254 write_lock(&rxrpc_call_lock); 255 list_add_tail(&call->link, &rxrpc_calls); 256 write_unlock(&rxrpc_call_lock); 257 258 /* Set up or get a connection record and set the protocol parameters, 259 * including channel number and call ID. 260 */ 261 ret = rxrpc_connect_call(call, cp, srx, gfp); 262 if (ret < 0) 263 goto error; 264 265 spin_lock_bh(&call->conn->params.peer->lock); 266 hlist_add_head(&call->error_link, 267 &call->conn->params.peer->error_targets); 268 spin_unlock_bh(&call->conn->params.peer->lock); 269 270 rxrpc_start_call_timer(call); 271 272 _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id); 273 274 _leave(" = %p [new]", call); 275 return call; 276 277 error: 278 write_lock(&rx->call_lock); 279 rb_erase(&call->sock_node, &rx->calls); 280 write_unlock(&rx->call_lock); 281 rxrpc_put_call(call, rxrpc_call_put_userid); 282 283 write_lock(&rxrpc_call_lock); 284 list_del_init(&call->link); 285 write_unlock(&rxrpc_call_lock); 286 287 error_out: 288 __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR, 289 RX_CALL_DEAD, ret); 290 set_bit(RXRPC_CALL_RELEASED, &call->flags); 291 rxrpc_put_call(call, rxrpc_call_put); 292 _leave(" = %d", ret); 293 return ERR_PTR(ret); 294 295 /* We unexpectedly found the user ID in the list after taking 296 * the call_lock. This shouldn't happen unless the user races 297 * with itself and tries to add the same user ID twice at the 298 * same time in different threads. 299 */ 300 found_user_ID_now_present: 301 write_unlock(&rx->call_lock); 302 ret = -EEXIST; 303 goto error_out; 304 } 305 306 /* 307 * Set up an incoming call. call->conn points to the connection. 308 * This is called in BH context and isn't allowed to fail. 309 */ 310 void rxrpc_incoming_call(struct rxrpc_sock *rx, 311 struct rxrpc_call *call, 312 struct sk_buff *skb) 313 { 314 struct rxrpc_connection *conn = call->conn; 315 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 316 u32 chan; 317 318 _enter(",%d", call->conn->debug_id); 319 320 rcu_assign_pointer(call->socket, rx); 321 call->call_id = sp->hdr.callNumber; 322 call->service_id = sp->hdr.serviceId; 323 call->cid = sp->hdr.cid; 324 call->state = RXRPC_CALL_SERVER_ACCEPTING; 325 if (sp->hdr.securityIndex > 0) 326 call->state = RXRPC_CALL_SERVER_SECURING; 327 328 /* Set the channel for this call. We don't get channel_lock as we're 329 * only defending against the data_ready handler (which we're called 330 * from) and the RESPONSE packet parser (which is only really 331 * interested in call_counter and can cope with a disagreement with the 332 * call pointer). 333 */ 334 chan = sp->hdr.cid & RXRPC_CHANNELMASK; 335 conn->channels[chan].call_counter = call->call_id; 336 conn->channels[chan].call_id = call->call_id; 337 rcu_assign_pointer(conn->channels[chan].call, call); 338 339 spin_lock(&conn->params.peer->lock); 340 hlist_add_head(&call->error_link, &conn->params.peer->error_targets); 341 spin_unlock(&conn->params.peer->lock); 342 343 _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id); 344 345 rxrpc_start_call_timer(call); 346 _leave(""); 347 } 348 349 /* 350 * Queue a call's work processor, getting a ref to pass to the work queue. 351 */ 352 bool rxrpc_queue_call(struct rxrpc_call *call) 353 { 354 const void *here = __builtin_return_address(0); 355 int n = __atomic_add_unless(&call->usage, 1, 0); 356 if (n == 0) 357 return false; 358 if (rxrpc_queue_work(&call->processor)) 359 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL); 360 else 361 rxrpc_put_call(call, rxrpc_call_put_noqueue); 362 return true; 363 } 364 365 /* 366 * Queue a call's work processor, passing the callers ref to the work queue. 367 */ 368 bool __rxrpc_queue_call(struct rxrpc_call *call) 369 { 370 const void *here = __builtin_return_address(0); 371 int n = atomic_read(&call->usage); 372 ASSERTCMP(n, >=, 1); 373 if (rxrpc_queue_work(&call->processor)) 374 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL); 375 else 376 rxrpc_put_call(call, rxrpc_call_put_noqueue); 377 return true; 378 } 379 380 /* 381 * Note the re-emergence of a call. 382 */ 383 void rxrpc_see_call(struct rxrpc_call *call) 384 { 385 const void *here = __builtin_return_address(0); 386 if (call) { 387 int n = atomic_read(&call->usage); 388 389 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL); 390 } 391 } 392 393 /* 394 * Note the addition of a ref on a call. 395 */ 396 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 397 { 398 const void *here = __builtin_return_address(0); 399 int n = atomic_inc_return(&call->usage); 400 401 trace_rxrpc_call(call, op, n, here, NULL); 402 } 403 404 /* 405 * Detach a call from its owning socket. 406 */ 407 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call) 408 { 409 struct rxrpc_connection *conn = call->conn; 410 bool put = false; 411 int i; 412 413 _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage)); 414 415 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 416 417 rxrpc_see_call(call); 418 419 spin_lock_bh(&call->lock); 420 if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags)) 421 BUG(); 422 spin_unlock_bh(&call->lock); 423 424 del_timer_sync(&call->timer); 425 426 /* Make sure we don't get any more notifications */ 427 write_lock_bh(&rx->recvmsg_lock); 428 429 if (!list_empty(&call->recvmsg_link)) { 430 _debug("unlinking once-pending call %p { e=%lx f=%lx }", 431 call, call->events, call->flags); 432 list_del(&call->recvmsg_link); 433 put = true; 434 } 435 436 /* list_empty() must return false in rxrpc_notify_socket() */ 437 call->recvmsg_link.next = NULL; 438 call->recvmsg_link.prev = NULL; 439 440 write_unlock_bh(&rx->recvmsg_lock); 441 if (put) 442 rxrpc_put_call(call, rxrpc_call_put); 443 444 write_lock(&rx->call_lock); 445 446 if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 447 rb_erase(&call->sock_node, &rx->calls); 448 memset(&call->sock_node, 0xdd, sizeof(call->sock_node)); 449 rxrpc_put_call(call, rxrpc_call_put_userid); 450 } 451 452 list_del(&call->sock_link); 453 write_unlock(&rx->call_lock); 454 455 _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn); 456 457 if (conn) 458 rxrpc_disconnect_call(call); 459 460 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) { 461 rxrpc_free_skb(call->rxtx_buffer[i]); 462 call->rxtx_buffer[i] = NULL; 463 } 464 465 /* We have to release the prealloc backlog ref */ 466 if (rxrpc_is_service_call(call)) 467 rxrpc_put_call(call, rxrpc_call_put); 468 _leave(""); 469 } 470 471 /* 472 * release all the calls associated with a socket 473 */ 474 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx) 475 { 476 struct rxrpc_call *call; 477 478 _enter("%p", rx); 479 480 while (!list_empty(&rx->sock_calls)) { 481 call = list_entry(rx->sock_calls.next, 482 struct rxrpc_call, sock_link); 483 rxrpc_get_call(call, rxrpc_call_got); 484 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET); 485 rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT); 486 rxrpc_release_call(rx, call); 487 rxrpc_put_call(call, rxrpc_call_put); 488 } 489 490 _leave(""); 491 } 492 493 /* 494 * release a call 495 */ 496 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op) 497 { 498 const void *here = __builtin_return_address(0); 499 int n; 500 501 ASSERT(call != NULL); 502 503 n = atomic_dec_return(&call->usage); 504 trace_rxrpc_call(call, op, n, here, NULL); 505 ASSERTCMP(n, >=, 0); 506 if (n == 0) { 507 _debug("call %d dead", call->debug_id); 508 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 509 510 write_lock(&rxrpc_call_lock); 511 list_del_init(&call->link); 512 write_unlock(&rxrpc_call_lock); 513 514 rxrpc_cleanup_call(call); 515 } 516 } 517 518 /* 519 * Final call destruction under RCU. 520 */ 521 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu) 522 { 523 struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu); 524 525 rxrpc_put_peer(call->peer); 526 kfree(call->rxtx_buffer); 527 kfree(call->rxtx_annotations); 528 kmem_cache_free(rxrpc_call_jar, call); 529 } 530 531 /* 532 * clean up a call 533 */ 534 void rxrpc_cleanup_call(struct rxrpc_call *call) 535 { 536 int i; 537 538 _net("DESTROY CALL %d", call->debug_id); 539 540 memset(&call->sock_node, 0xcd, sizeof(call->sock_node)); 541 542 del_timer_sync(&call->timer); 543 544 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE); 545 ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags)); 546 ASSERTCMP(call->conn, ==, NULL); 547 548 /* Clean up the Rx/Tx buffer */ 549 for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) 550 rxrpc_free_skb(call->rxtx_buffer[i]); 551 552 rxrpc_free_skb(call->tx_pending); 553 554 call_rcu(&call->rcu, rxrpc_rcu_destroy_call); 555 } 556 557 /* 558 * Make sure that all calls are gone. 559 */ 560 void __exit rxrpc_destroy_all_calls(void) 561 { 562 struct rxrpc_call *call; 563 564 _enter(""); 565 566 if (list_empty(&rxrpc_calls)) 567 return; 568 569 write_lock(&rxrpc_call_lock); 570 571 while (!list_empty(&rxrpc_calls)) { 572 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link); 573 _debug("Zapping call %p", call); 574 575 rxrpc_see_call(call); 576 list_del_init(&call->link); 577 578 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n", 579 call, atomic_read(&call->usage), 580 rxrpc_call_states[call->state], 581 call->flags, call->events); 582 583 write_unlock(&rxrpc_call_lock); 584 cond_resched(); 585 write_lock(&rxrpc_call_lock); 586 } 587 588 write_unlock(&rxrpc_call_lock); 589 } 590