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         call->tx_total_len = -1;
 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         call->cong_cwnd = 2;
 140         call->cong_ssthresh = RXRPC_RXTX_BUFF_SIZE - 1;
 141         return call;
 142
 143 nomem_2:
 144         kfree(call->rxtx_buffer);
 145 nomem:
 146         kmem_cache_free(rxrpc_call_jar, call);
 147         return NULL;
 148 }
 149
 150 /*
 151  * Allocate a new client call.
 152  */
 153 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
 154                                                   gfp_t gfp)
 155 {
 156         struct rxrpc_call *call;
 157         ktime_t now;
 158
 159         _enter("");
 160
 161         call = rxrpc_alloc_call(gfp);
 162         if (!call)
 163                 return ERR_PTR(-ENOMEM);
 164         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 165         call->service_id = srx->srx_service;
 166         call->tx_phase = true;
 167         now = ktime_get_real();
 168         call->acks_latest_ts = now;
 169         call->cong_tstamp = now;
 170
 171         _leave(" = %p", call);
 172         return call;
 173 }
 174
 175 /*
 176  * Initiate the call ack/resend/expiry timer.
 177  */
 178 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 179 {
 180         ktime_t now = ktime_get_real(), expire_at;
 181
 182         expire_at = ktime_add_ms(now, rxrpc_max_call_lifetime);
 183         call->expire_at = expire_at;
 184         call->ack_at = expire_at;
 185         call->ping_at = expire_at;
 186         call->resend_at = expire_at;
 187         call->timer.expires = jiffies + LONG_MAX / 2;
 188         rxrpc_set_timer(call, rxrpc_timer_begin, now);
 189 }
 190
 191 /*
 192  * Set up a call for the given parameters.
 193  * - Called with the socket lock held, which it must release.
 194  * - If it returns a call, the call's lock will need releasing by the caller.
 195  */
 196 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 197                                          struct rxrpc_conn_parameters *cp,
 198                                          struct sockaddr_rxrpc *srx,
 199                                          unsigned long user_call_ID,
 200                                          s64 tx_total_len,
 201                                          gfp_t gfp)
 202         __releases(&rx->sk.sk_lock.slock)
 203 {
 204         struct rxrpc_call *call, *xcall;
 205         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
 206         struct rb_node *parent, **pp;
 207         const void *here = __builtin_return_address(0);
 208         int ret;
 209
 210         _enter("%p,%lx", rx, user_call_ID);
 211
 212         call = rxrpc_alloc_client_call(srx, gfp);
 213         if (IS_ERR(call)) {
 214                 release_sock(&rx->sk);
 215                 _leave(" = %ld", PTR_ERR(call));
 216                 return call;
 217         }
 218
 219         call->tx_total_len = tx_total_len;
 220         trace_rxrpc_call(call, rxrpc_call_new_client, atomic_read(&call->usage),
 221                          here, (const void *)user_call_ID);
 222
 223         /* We need to protect a partially set up call against the user as we
 224          * will be acting outside the socket lock.
 225          */
 226         mutex_lock(&call->user_mutex);
 227
 228         /* Publish the call, even though it is incompletely set up as yet */
 229         write_lock(&rx->call_lock);
 230
 231         pp = &rx->calls.rb_node;
 232         parent = NULL;
 233         while (*pp) {
 234                 parent = *pp;
 235                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 236
 237                 if (user_call_ID < xcall->user_call_ID)
 238                         pp = &(*pp)->rb_left;
 239                 else if (user_call_ID > xcall->user_call_ID)
 240                         pp = &(*pp)->rb_right;
 241                 else
 242                         goto error_dup_user_ID;
 243         }
 244
 245         rcu_assign_pointer(call->socket, rx);
 246         call->user_call_ID = user_call_ID;
 247         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 248         rxrpc_get_call(call, rxrpc_call_got_userid);
 249         rb_link_node(&call->sock_node, parent, pp);
 250         rb_insert_color(&call->sock_node, &rx->calls);
 251         list_add(&call->sock_link, &rx->sock_calls);
 252
 253         write_unlock(&rx->call_lock);
 254
 255         write_lock(&rxnet->call_lock);
 256         list_add_tail(&call->link, &rxnet->calls);
 257         write_unlock(&rxnet->call_lock);
 258
 259         /* From this point on, the call is protected by its own lock. */
 260         release_sock(&rx->sk);
 261
 262         /* Set up or get a connection record and set the protocol parameters,
 263          * including channel number and call ID.
 264          */
 265         ret = rxrpc_connect_call(call, cp, srx, gfp);
 266         if (ret < 0)
 267                 goto error;
 268
 269         trace_rxrpc_call(call, rxrpc_call_connected, atomic_read(&call->usage),
 270                          here, NULL);
 271
 272         spin_lock_bh(&call->conn->params.peer->lock);
 273         hlist_add_head(&call->error_link,
 274                        &call->conn->params.peer->error_targets);
 275         spin_unlock_bh(&call->conn->params.peer->lock);
 276
 277         rxrpc_start_call_timer(call);
 278
 279         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 280
 281         _leave(" = %p [new]", call);
 282         return call;
 283
 284         /* We unexpectedly found the user ID in the list after taking
 285          * the call_lock.  This shouldn't happen unless the user races
 286          * with itself and tries to add the same user ID twice at the
 287          * same time in different threads.
 288          */
 289 error_dup_user_ID:
 290         write_unlock(&rx->call_lock);
 291         release_sock(&rx->sk);
 292         ret = -EEXIST;
 293
 294 error:
 295         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 296                                     RX_CALL_DEAD, ret);
 297         trace_rxrpc_call(call, rxrpc_call_error, atomic_read(&call->usage),
 298                          here, ERR_PTR(ret));
 299         rxrpc_release_call(rx, call);
 300         mutex_unlock(&call->user_mutex);
 301         rxrpc_put_call(call, rxrpc_call_put);
 302         _leave(" = %d", ret);
 303         return ERR_PTR(ret);
 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         call->cong_tstamp       = skb->tstamp;
 328
 329         /* Set the channel for this call.  We don't get channel_lock as we're
 330          * only defending against the data_ready handler (which we're called
 331          * from) and the RESPONSE packet parser (which is only really
 332          * interested in call_counter and can cope with a disagreement with the
 333          * call pointer).
 334          */
 335         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 336         conn->channels[chan].call_counter = call->call_id;
 337         conn->channels[chan].call_id = call->call_id;
 338         rcu_assign_pointer(conn->channels[chan].call, call);
 339
 340         spin_lock(&conn->params.peer->lock);
 341         hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
 342         spin_unlock(&conn->params.peer->lock);
 343
 344         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 345
 346         rxrpc_start_call_timer(call);
 347         _leave("");
 348 }
 349
 350 /*
 351  * Queue a call's work processor, getting a ref to pass to the work queue.
 352  */
 353 bool rxrpc_queue_call(struct rxrpc_call *call)
 354 {
 355         const void *here = __builtin_return_address(0);
 356         int n = __atomic_add_unless(&call->usage, 1, 0);
 357         if (n == 0)
 358                 return false;
 359         if (rxrpc_queue_work(&call->processor))
 360                 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
 361         else
 362                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 363         return true;
 364 }
 365
 366 /*
 367  * Queue a call's work processor, passing the callers ref to the work queue.
 368  */
 369 bool __rxrpc_queue_call(struct rxrpc_call *call)
 370 {
 371         const void *here = __builtin_return_address(0);
 372         int n = atomic_read(&call->usage);
 373         ASSERTCMP(n, >=, 1);
 374         if (rxrpc_queue_work(&call->processor))
 375                 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
 376         else
 377                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 378         return true;
 379 }
 380
 381 /*
 382  * Note the re-emergence of a call.
 383  */
 384 void rxrpc_see_call(struct rxrpc_call *call)
 385 {
 386         const void *here = __builtin_return_address(0);
 387         if (call) {
 388                 int n = atomic_read(&call->usage);
 389
 390                 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
 391         }
 392 }
 393
 394 /*
 395  * Note the addition of a ref on a call.
 396  */
 397 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 398 {
 399         const void *here = __builtin_return_address(0);
 400         int n = atomic_inc_return(&call->usage);
 401
 402         trace_rxrpc_call(call, op, n, here, NULL);
 403 }
 404
 405 /*
 406  * Detach a call from its owning socket.
 407  */
 408 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 409 {
 410         const void *here = __builtin_return_address(0);
 411         struct rxrpc_connection *conn = call->conn;
 412         bool put = false;
 413         int i;
 414
 415         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
 416
 417         trace_rxrpc_call(call, rxrpc_call_release, atomic_read(&call->usage),
 418                          here, (const void *)call->flags);
 419
 420         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 421
 422         spin_lock_bh(&call->lock);
 423         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 424                 BUG();
 425         spin_unlock_bh(&call->lock);
 426
 427         del_timer_sync(&call->timer);
 428
 429         /* Make sure we don't get any more notifications */
 430         write_lock_bh(&rx->recvmsg_lock);
 431
 432         if (!list_empty(&call->recvmsg_link)) {
 433                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 434                        call, call->events, call->flags);
 435                 list_del(&call->recvmsg_link);
 436                 put = true;
 437         }
 438
 439         /* list_empty() must return false in rxrpc_notify_socket() */
 440         call->recvmsg_link.next = NULL;
 441         call->recvmsg_link.prev = NULL;
 442
 443         write_unlock_bh(&rx->recvmsg_lock);
 444         if (put)
 445                 rxrpc_put_call(call, rxrpc_call_put);
 446
 447         write_lock(&rx->call_lock);
 448
 449         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 450                 rb_erase(&call->sock_node, &rx->calls);
 451                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 452                 rxrpc_put_call(call, rxrpc_call_put_userid);
 453         }
 454
 455         list_del(&call->sock_link);
 456         write_unlock(&rx->call_lock);
 457
 458         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 459
 460         if (conn)
 461                 rxrpc_disconnect_call(call);
 462
 463         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
 464                 rxrpc_free_skb(call->rxtx_buffer[i],
 465                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 466                                 rxrpc_skb_rx_cleaned));
 467                 call->rxtx_buffer[i] = NULL;
 468         }
 469
 470         _leave("");
 471 }
 472
 473 /*
 474  * release all the calls associated with a socket
 475  */
 476 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 477 {
 478         struct rxrpc_call *call;
 479
 480         _enter("%p", rx);
 481
 482         while (!list_empty(&rx->to_be_accepted)) {
 483                 call = list_entry(rx->to_be_accepted.next,
 484                                   struct rxrpc_call, accept_link);
 485                 list_del(&call->accept_link);
 486                 rxrpc_abort_call("SKR", call, 0, RX_CALL_DEAD, -ECONNRESET);
 487                 rxrpc_put_call(call, rxrpc_call_put);
 488         }
 489
 490         while (!list_empty(&rx->sock_calls)) {
 491                 call = list_entry(rx->sock_calls.next,
 492                                   struct rxrpc_call, sock_link);
 493                 rxrpc_get_call(call, rxrpc_call_got);
 494                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, -ECONNRESET);
 495                 rxrpc_send_abort_packet(call);
 496                 rxrpc_release_call(rx, call);
 497                 rxrpc_put_call(call, rxrpc_call_put);
 498         }
 499
 500         _leave("");
 501 }
 502
 503 /*
 504  * release a call
 505  */
 506 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 507 {
 508         struct rxrpc_net *rxnet;
 509         const void *here = __builtin_return_address(0);
 510         int n;
 511
 512         ASSERT(call != NULL);
 513
 514         n = atomic_dec_return(&call->usage);
 515         trace_rxrpc_call(call, op, n, here, NULL);
 516         ASSERTCMP(n, >=, 0);
 517         if (n == 0) {
 518                 _debug("call %d dead", call->debug_id);
 519                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 520
 521                 if (!list_empty(&call->link)) {
 522                         rxnet = rxrpc_net(sock_net(&call->socket->sk));
 523                         write_lock(&rxnet->call_lock);
 524                         list_del_init(&call->link);
 525                         write_unlock(&rxnet->call_lock);
 526                 }
 527
 528                 rxrpc_cleanup_call(call);
 529         }
 530 }
 531
 532 /*
 533  * Final call destruction under RCU.
 534  */
 535 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 536 {
 537         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 538
 539         rxrpc_put_peer(call->peer);
 540         kfree(call->rxtx_buffer);
 541         kfree(call->rxtx_annotations);
 542         kmem_cache_free(rxrpc_call_jar, call);
 543 }
 544
 545 /*
 546  * clean up a call
 547  */
 548 void rxrpc_cleanup_call(struct rxrpc_call *call)
 549 {
 550         int i;
 551
 552         _net("DESTROY CALL %d", call->debug_id);
 553
 554         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 555
 556         del_timer_sync(&call->timer);
 557
 558         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 559         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 560         ASSERTCMP(call->conn, ==, NULL);
 561
 562         /* Clean up the Rx/Tx buffer */
 563         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
 564                 rxrpc_free_skb(call->rxtx_buffer[i],
 565                                (call->tx_phase ? rxrpc_skb_tx_cleaned :
 566                                 rxrpc_skb_rx_cleaned));
 567
 568         rxrpc_free_skb(call->tx_pending, rxrpc_skb_tx_cleaned);
 569
 570         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 571 }
 572
 573 /*
 574  * Make sure that all calls are gone from a network namespace.  To reach this
 575  * point, any open UDP sockets in that namespace must have been closed, so any
 576  * outstanding calls cannot be doing I/O.
 577  */
 578 void rxrpc_destroy_all_calls(struct rxrpc_net *rxnet)
 579 {
 580         struct rxrpc_call *call;
 581
 582         _enter("");
 583
 584         if (list_empty(&rxnet->calls))
 585                 return;
 586
 587         write_lock(&rxnet->call_lock);
 588
 589         while (!list_empty(&rxnet->calls)) {
 590                 call = list_entry(rxnet->calls.next, struct rxrpc_call, link);
 591                 _debug("Zapping call %p", call);
 592
 593                 rxrpc_see_call(call);
 594                 list_del_init(&call->link);
 595
 596                 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 597                        call, atomic_read(&call->usage),
 598                        rxrpc_call_states[call->state],
 599                        call->flags, call->events);
 600
 601                 write_unlock(&rxnet->call_lock);
 602                 cond_resched();
 603                 write_lock(&rxnet->call_lock);
 604         }
 605
 606         write_unlock(&rxnet->call_lock);
 607 }