net/rxrpc/call_object.c

   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 }