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
  48 static void rxrpc_call_timer_expired(unsigned long _call)
  49 {
  50         struct rxrpc_call *call = (struct rxrpc_call *)_call;
  51
  52         _enter("%d", call->debug_id);
  53
  54         if (call->state < RXRPC_CALL_COMPLETE)
  55                 rxrpc_set_timer(call, rxrpc_timer_expired, ktime_get_real());
  56 }
  57
  58 /*
  59  * find an extant server call
  60  * - called in process context with IRQs enabled
  61  */
  62 struct rxrpc_call *rxrpc_find_call_by_user_ID(struct rxrpc_sock *rx,
  63                                               unsigned long user_call_ID)
  64 {
  65         struct rxrpc_call *call;
  66         struct rb_node *p;
  67
  68         _enter("%p,%lx", rx, user_call_ID);
  69
  70         read_lock(&rx->call_lock);
  71
  72         p = rx->calls.rb_node;
  73         while (p) {
  74                 call = rb_entry(p, struct rxrpc_call, sock_node);
  75
  76                 if (user_call_ID < call->user_call_ID)
  77                         p = p->rb_left;
  78                 else if (user_call_ID > call->user_call_ID)
  79                         p = p->rb_right;
  80                 else
  81                         goto found_extant_call;
  82         }
  83
  84         read_unlock(&rx->call_lock);
  85         _leave(" = NULL");
  86         return NULL;
  87
  88 found_extant_call:
  89         rxrpc_get_call(call, rxrpc_call_got);
  90         read_unlock(&rx->call_lock);
  91         _leave(" = %p [%d]", call, atomic_read(&call->usage));
  92         return call;
  93 }
  94
  95 /*
  96  * allocate a new call
  97  */
  98 struct rxrpc_call *rxrpc_alloc_call(gfp_t gfp)
  99 {
 100         struct rxrpc_call *call;
 101
 102         call = kmem_cache_zalloc(rxrpc_call_jar, gfp);
 103         if (!call)
 104                 return NULL;
 105
 106         call->rxtx_buffer = kcalloc(RXRPC_RXTX_BUFF_SIZE,
 107                                     sizeof(struct sk_buff *),
 108                                     gfp);
 109         if (!call->rxtx_buffer)
 110                 goto nomem;
 111
 112         call->rxtx_annotations = kcalloc(RXRPC_RXTX_BUFF_SIZE, sizeof(u8), gfp);
 113         if (!call->rxtx_annotations)
 114                 goto nomem_2;
 115
 116         mutex_init(&call->user_mutex);
 117         setup_timer(&call->timer, rxrpc_call_timer_expired,
 118                     (unsigned long)call);
 119         INIT_WORK(&call->processor, &rxrpc_process_call);
 120         INIT_LIST_HEAD(&call->link);
 121         INIT_LIST_HEAD(&call->chan_wait_link);
 122         INIT_LIST_HEAD(&call->accept_link);
 123         INIT_LIST_HEAD(&call->recvmsg_link);
 124         INIT_LIST_HEAD(&call->sock_link);
 125         init_waitqueue_head(&call->waitq);
 126         spin_lock_init(&call->lock);
 127         rwlock_init(&call->state_lock);
 128         atomic_set(&call->usage, 1);
 129         call->debug_id = atomic_inc_return(&rxrpc_debug_id);
 130
 131         memset(&call->sock_node, 0xed, sizeof(call->sock_node));
 132
 133         /* Leave space in the ring to handle a maxed-out jumbo packet */
 134         call->rx_winsize = rxrpc_rx_window_size;
 135         call->tx_winsize = 16;
 136         call->rx_expect_next = 1;
 137
 138         if (RXRPC_TX_SMSS > 2190)
 139                 call->cong_cwnd = 2;
 140         else if (RXRPC_TX_SMSS > 1095)
 141                 call->cong_cwnd = 3;
 142         else
 143                 call->cong_cwnd = 4;
 144         call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
 145         return call;
 146
 147 nomem_2:
 148         kfree(call->rxtx_buffer);
 149 nomem:
 150         kmem_cache_free(rxrpc_call_jar, call);
 151         return NULL;
 152 }
 153
 154 /*
 155  * Allocate a new client call.
 156  */
 157 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
 158                                                   gfp_t gfp)
 159 {
 160         struct rxrpc_call *call;
 161         ktime_t now;
 162
 163         _enter("");
 164
 165         call = rxrpc_alloc_call(gfp);
 166         if (!call)
 167                 return ERR_PTR(-ENOMEM);
 168         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 169         call->service_id = srx->srx_service;
 170         call->tx_phase = true;
 171         now = ktime_get_real();
 172         call->acks_latest_ts = now;
 173         call->cong_tstamp = now;
 174
 175         _leave(" = %p", call);
 176         return call;
 177 }
 178
 179 /*
 180  * Initiate the call ack/resend/expiry timer.
 181  */
 182 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 183 {
 184         ktime_t now = ktime_get_real(), expire_at;
 185
 186         expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime);
 187         call->expire_at = expire_at;
 188         call->ack_at = expire_at;
 189         call->ping_at = expire_at;
 190         call->resend_at = expire_at;
 191         call->timer.expires = jiffies + LONG_MAX / 2;
 192         rxrpc_set_timer(call, rxrpc_timer_begin, now);
 193 }
 194
 195 /*
 196  * Set up a call for the given parameters.
 197  * - Called with the socket lock held, which it must release.
 198  * - If it returns a call, the call's lock will need releasing by the caller.
 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         __releases(&rx->sk.sk_lock.slock)
 206 {
 207         struct rxrpc_call *call, *xcall;
 208         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
 209         struct rb_node *parent, **pp;
 210         const void *here = __builtin_return_address(0);
 211         int ret;
 212
 213         _enter("%p,%lx", rx, user_call_ID);
 214
 215         call = rxrpc_alloc_client_call(srx, gfp);
 216         if (IS_ERR(call)) {
 217                 release_sock(&rx->sk);
 218                 _leave(" = %ld", PTR_ERR(call));
 219                 return call;
 220         }
 221
 222         trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
 223                          here, (const void *)user_call_ID);
 224
 225         /* We need to protect a partially set up call against the user as we
 226          * will be acting outside the socket lock.
 227          */
 228         mutex_lock(&call->user_mutex);
 229
 230         /* Publish the call, even though it is incompletely set up as yet */
 231         write_lock(&rx->call_lock);
 232
 233         pp = &rx->calls.rb_node;
 234         parent = NULL;
 235         while (*pp) {
 236                 parent = *pp;
 237                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 238
 239                 if (user_call_ID < xcall->user_call_ID)
 240                         pp = &(*pp)->rb_left;
 241                 else if (user_call_ID > xcall->user_call_ID)
 242                         pp = &(*pp)->rb_right;
 243                 else
 244                         goto error_dup_user_ID;
 245         }
 246
 247         rcu_assign_pointer(call->socket, rx);
 248         call->user_call_ID = user_call_ID;
 249         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 250         rxrpc_get_call(call, rxrpc_call_got_userid);
 251         rb_link_node(&call->sock_node, parent, pp);
 252         rb_insert_color(&call->sock_node, &rx->calls);
 253         list_add(&call->sock_link, &rx->sock_calls);
 254
 255         write_unlock(&rx->call_lock);
 256
 257         write_lock(&rxnet->call_lock);
 258         list_add_tail(&call->link, &rxnet->calls);
 259         write_unlock(&rxnet->call_lock);
 260
 261         /* From this point on, the call is protected by its own lock. */
 262         release_sock(&rx->sk);
 263
 264         /* Set up or get a connection record and set the protocol parameters,
 265          * including channel number and call ID.
 266          */
 267         ret = rxrpc_connect_call(call, cp, srx, gfp);
 268         if (ret < 0)
 269                 goto error;
 270
 271         trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
 272                          here, NULL);
 273
 274         spin_lock_bh(&call->conn->params.peer->lock);
 275         hlist_add_head(&call->error_link,
 276                        &call->conn->params.peer->error_targets);
 277         spin_unlock_bh(&call->conn->params.peer->lock);
 278
 279         rxrpc_start_call_timer(call);
 280
 281         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 282
 283         _leave(" = %p [new]", call);
 284         return call;
 285
 286         /* We unexpectedly found the user ID in the list after taking
 287          * the call_lock.  This shouldn't happen unless the user races
 288          * with itself and tries to add the same user ID twice at the
 289          * same time in different threads.
 290          */
 291 error_dup_user_ID:
 292         write_unlock(&rx->call_lock);
 293         release_sock(&rx->sk);
 294         ret = -EEXIST;
 295
 296 error:
 297         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 298                                     RX_CALL_DEAD, ret);
 299         trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
 300                          here, ERR_PTR(ret));
 301         rxrpc_release_call(rx, call);
 302         mutex_unlock(&call->user_mutex);
 303         rxrpc_put_call(call, rxrpc_call_put);
 304         _leave(" = %d", ret);
 305         return ERR_PTR(ret);
 306 }
 307
 308 /*
 309  * Set up an incoming call.  call->conn points to the connection.
 310  * This is called in BH context and isn't allowed to fail.
 311  */
 312 void rxrpc_incoming_call(struct rxrpc_sock *rx,
 313                          struct rxrpc_call *call,
 314                          struct sk_buff *skb)
 315 {
 316         struct rxrpc_connection *conn = call->conn;
 317         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 318         u32 chan;
 319
 320         _enter(",%d", call->conn->debug_id);
 321
 322         rcu_assign_pointer(call->socket, rx);
 323         call->call_id           = sp->hdr.callNumber;
 324         call->service_id        = sp->hdr.serviceId;
 325         call->cid               = sp->hdr.cid;
 326         call->state             = RXRPC_CALL_SERVER_ACCEPTING;
 327         if (sp->hdr.securityIndex > 0)
 328                 call->state     = RXRPC_CALL_SERVER_SECURING;
 329         call->cong_tstamp       = skb->tstamp;
 330
 331         /* Set the channel for this call.  We don't get channel_lock as we're
 332          * only defending against the data_ready handler (which we're called
 333          * from) and the RESPONSE packet parser (which is only really
 334          * interested in call_counter and can cope with a disagreement with the
 335          * call pointer).
 336          */
 337         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 338         conn->channels[chan].call_counter = call->call_id;
 339         conn->channels[chan].call_id = call->call_id;
 340         rcu_assign_pointer(conn->channels[chan].call, call);
 341
 342         spin_lock(&conn->params.peer->lock);
 343         hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
 344         spin_unlock(&conn->params.peer->lock);
 345
 346         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 347
 348         rxrpc_start_call_timer(call);
 349         _leave("");
 350 }
 351
 352 /*
 353  * Queue a call's work processor, getting a ref to pass to the work queue.
 354  */
 355 bool rxrpc_queue_call(struct rxrpc_call *call)
 356 {
 357         const void *here = __builtin_return_address(0);
 358         int n = __atomic_add_unless(&call->usage, 1, 0);
 359         if (n == 0)
 360                 return false;
 361         if (rxrpc_queue_work(&call->processor))
 362                 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
 363         else
 364                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 365         return true;
 366 }
 367
 368 /*
 369  * Queue a call's work processor, passing the callers ref to the work queue.
 370  */
 371 bool __rxrpc_queue_call(struct rxrpc_call *call)
 372 {
 373         const void *here = __builtin_return_address(0);
 374         int n = atomic_read(&call->usage);
 375         ASSERTCMP(n, >=, 1);
 376         if (rxrpc_queue_work(&call->processor))
 377                 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
 378         else
 379                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 380         return true;
 381 }
 382
 383 /*
 384  * Note the re-emergence of a call.
 385  */
 386 void rxrpc_see_call(struct rxrpc_call *call)
 387 {
 388         const void *here = __builtin_return_address(0);
 389         if (call) {
 390                 int n = atomic_read(&call->usage);
 391
 392                 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
 393         }
 394 }
 395
 396 /*
 397  * Note the addition of a ref on a call.
 398  */
 399 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 400 {
 401         const void *here = __builtin_return_address(0);
 402         int n = atomic_inc_return(&call->usage);
 403
 404         trace_rxrpc_call(call, op, n, here, NULL);
 405 }
 406
 407 /*
 408  * Detach a call from its owning socket.
 409  */
 410 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 411 {
 412         const void *here = __builtin_return_address(0);
 413         struct rxrpc_connection *conn = call->conn;
 414         bool put = false;
 415         int i;
 416
 417         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
 418
 419         trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
 420                          here, (const void *)call->flags);
 421
 422         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 423
 424         spin_lock_bh(&call->lock);
 425         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 426                 BUG();
 427         spin_unlock_bh(&call->lock);
 428
 429         del_timer_sync(&call->timer);
 430
 431         /* Make sure we don't get any more notifications */
 432         write_lock_bh(&rx->recvmsg_lock);
 433
 434         if (!list_empty(&call->recvmsg_link)) {
 435                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 436                        call, call->events, call->flags);
 437                 list_del(&call->recvmsg_link);
 438                 put = true;
 439         }
 440
 441         /* list_empty() must return false in rxrpc_notify_socket() */
 442         call->recvmsg_link.next = NULL;
 443         call->recvmsg_link.prev = NULL;
 444
 445         write_unlock_bh(&rx->recvmsg_lock);
 446         if (put)
 447                 rxrpc_put_call(call, rxrpc_call_put);
 448
 449         write_lock(&rx->call_lock);
 450
 451         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 452                 rb_erase(&call->sock_node, &rx->calls);
 453                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 454                 rxrpc_put_call(call, rxrpc_call_put_userid);
 455         }
 456
 457         list_del(&call->sock_link);
 458         write_unlock(&rx->call_lock);
 459
 460         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 461
 462         if (conn)
 463                 rxrpc_disconnect_call(call);
 464
 465         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
 466                 rxrpc_free_skb(call->rxtx_buffer[i],
 467                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 468                                 rxrpc_skb_rx_cleaned));
 469                 call->rxtx_buffer[i] = NULL;
 470         }
 471
 472         _leave("");
 473 }
 474
 475 /*
 476  * release all the calls associated with a socket
 477  */
 478 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 479 {
 480         struct rxrpc_call *call;
 481
 482         _enter("%p", rx);
 483
 484         while (!list_empty(&rx->to_be_accepted)) {
 485                 call = list_entry(rx->to_be_accepted.next,
 486                                   struct rxrpc_call, accept_link);
 487                 list_del(&call->accept_link);
 488                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
 489                 rxrpc_put_call(call, rxrpc_call_put);
 490         }
 491
 492         while (!list_empty(&rx->sock_calls)) {
 493                 call = list_entry(rx->sock_calls.next,
 494                                   struct rxrpc_call, sock_link);
 495                 rxrpc_get_call(call, rxrpc_call_got);
 496                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
 497                 rxrpc_send_abort_packet(call);
 498                 rxrpc_release_call(rx, call);
 499                 rxrpc_put_call(call, rxrpc_call_put);
 500         }
 501
 502         _leave("");
 503 }
 504
 505 /*
 506  * release a call
 507  */
 508 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 509 {
 510         struct rxrpc_net *rxnet;
 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                 if (!list_empty(&call->link)) {
 524                         rxnet = rxrpc_net(sock_net(&call->socket->sk));
 525                         write_lock(&rxnet->call_lock);
 526                         list_del_init(&call->link);
 527                         write_unlock(&rxnet->call_lock);
 528                 }
 529
 530                 rxrpc_cleanup_call(call);
 531         }
 532 }
 533
 534 /*
 535  * Final call destruction under RCU.
 536  */
 537 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 538 {
 539         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 540
 541         rxrpc_put_peer(call->peer);
 542         kfree(call->rxtx_buffer);
 543         kfree(call->rxtx_annotations);
 544         kmem_cache_free(rxrpc_call_jar, call);
 545 }
 546
 547 /*
 548  * clean up a call
 549  */
 550 void rxrpc_cleanup_call(struct rxrpc_call *call)
 551 {
 552         int i;
 553
 554         _net("DESTROY CALL %d", call->debug_id);
 555
 556         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 557
 558         del_timer_sync(&call->timer);
 559
 560         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 561         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 562         ASSERTCMP(call->conn, ==, NULL);
 563
 564         /* Clean up the Rx/Tx buffer */
 565         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
 566                 rxrpc_free_skb(call->rxtx_buffer[i],
 567                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 568                                 rxrpc_skb_rx_cleaned));
 569
 570         rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
 571
 572         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 573 }
 574
 575 /*
 576  * Make sure that all calls are gone from a network namespace.  To reach this
 577  * point, any open UDP sockets in that namespace must have been closed, so any
 578  * outstanding calls cannot be doing I/O.
 579  */
 580 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 581 {
 582         struct rxrpc_call *call;
 583
 584         _enter("");
 585
 586         if (list_empty(&rxnet->calls))
 587                 return;
 588
 589         write_lock(&rxnet->call_lock);
 590
 591         while (!list_empty(&rxnet->calls)) {
 592                 call = list_entry(rxnet->calls.next, struct rxrpc_call, link);
 593                 _debug("Zapping call %p", call);
 594
 595                 rxrpc_see_call(call);
 596                 list_del_init(&call->link);
 597
 598                 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 599                        call, atomic_read(&call->usage),
 600                        rxrpc_call_states[call->state],
 601                        call->flags, call->events);
 602
 603                 write_unlock(&rxnet->call_lock);
 604                 cond_resched();
 605                 write_lock(&rxnet->call_lock);
 606         }
 607
 608         write_unlock(&rxnet->call_lock);
 609 }