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         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 }