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 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 }