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 /*
  23  * Maximum lifetime of a call (in jiffies).
  24  */
  25 unsigned int rxrpc_max_call_lifetime = 60 * HZ;
  26
  27 const char *const rxrpc_call_states[NR__RXRPC_CALL_STATES] = {
  28         [RXRPC_CALL_UNINITIALISED]              = "Uninit  ",
  29         [RXRPC_CALL_CLIENT_AWAIT_CONN]          = "ClWtConn",
  30         [RXRPC_CALL_CLIENT_SEND_REQUEST]        = "ClSndReq",
  31         [RXRPC_CALL_CLIENT_AWAIT_REPLY]         = "ClAwtRpl",
  32         [RXRPC_CALL_CLIENT_RECV_REPLY]          = "ClRcvRpl",
  33         [RXRPC_CALL_SERVER_PREALLOC]            = "SvPrealc",
  34         [RXRPC_CALL_SERVER_SECURING]            = "SvSecure",
  35         [RXRPC_CALL_SERVER_ACCEPTING]           = "SvAccept",
  36         [RXRPC_CALL_SERVER_RECV_REQUEST]        = "SvRcvReq",
  37         [RXRPC_CALL_SERVER_ACK_REQUEST]         = "SvAckReq",
  38         [RXRPC_CALL_SERVER_SEND_REPLY]          = "SvSndRpl",
  39         [RXRPC_CALL_SERVER_AWAIT_ACK]           = "SvAwtACK",
  40         [RXRPC_CALL_COMPLETE]                   = "Complete",
  41 };
  42
  43 const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = {
  44         [RXRPC_CALL_SUCCEEDED]                  = "Complete",
  45         [RXRPC_CALL_REMOTELY_ABORTED]           = "RmtAbort",
  46         [RXRPC_CALL_LOCALLY_ABORTED]            = "LocAbort",
  47         [RXRPC_CALL_LOCAL_ERROR]                = "LocError",
  48         [RXRPC_CALL_NETWORK_ERROR]              = "NetError",
  49 };
  50
  51 const char rxrpc_call_traces[rxrpc_call__nr_trace][4] = {
  52         [rxrpc_call_new_client]         = "NWc",
  53         [rxrpc_call_new_service]        = "NWs",
  54         [rxrpc_call_queued]             = "QUE",
  55         [rxrpc_call_queued_ref]         = "QUR",
  56         [rxrpc_call_seen]               = "SEE",
  57         [rxrpc_call_got]                = "GOT",
  58         [rxrpc_call_got_userid]         = "Gus",
  59         [rxrpc_call_put]                = "PUT",
  60         [rxrpc_call_put_userid]         = "Pus",
  61         [rxrpc_call_put_noqueue]        = "PNQ",
  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_queue_call(call);
  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_RXTX_BUFF_SIZE - 1 - 46;
 154         call->tx_winsize = 16;
 155         call->rx_expect_next = 1;
 156         return call;
 157
 158 nomem_2:
 159         kfree(call->rxtx_buffer);
 160 nomem:
 161         kmem_cache_free(rxrpc_call_jar, call);
 162         return NULL;
 163 }
 164
 165 /*
 166  * Allocate a new client call.
 167  */
 168 static struct rxrpc_call *rxrpc_alloc_client_call(struct sockaddr_rxrpc *srx,
 169                                                   gfp_t gfp)
 170 {
 171         struct rxrpc_call *call;
 172
 173         _enter("");
 174
 175         call = rxrpc_alloc_call(gfp);
 176         if (!call)
 177                 return ERR_PTR(-ENOMEM);
 178         call->state = RXRPC_CALL_CLIENT_AWAIT_CONN;
 179         call->service_id = srx->srx_service;
 180
 181         _leave(" = %p", call);
 182         return call;
 183 }
 184
 185 /*
 186  * Initiate the call ack/resend/expiry timer.
 187  */
 188 static void rxrpc_start_call_timer(struct rxrpc_call *call)
 189 {
 190         unsigned long expire_at;
 191
 192         expire_at = jiffies + rxrpc_max_call_lifetime;
 193         call->expire_at = expire_at;
 194         call->ack_at = expire_at;
 195         call->resend_at = expire_at;
 196         call->timer.expires = expire_at;
 197         add_timer(&call->timer);
 198 }
 199
 200 /*
 201  * set up a call for the given data
 202  * - called in process context with IRQs enabled
 203  */
 204 struct rxrpc_call *rxrpc_new_client_call(struct rxrpc_sock *rx,
 205                                          struct rxrpc_conn_parameters *cp,
 206                                          struct sockaddr_rxrpc *srx,
 207                                          unsigned long user_call_ID,
 208                                          gfp_t gfp)
 209 {
 210         struct rxrpc_call *call, *xcall;
 211         struct rb_node *parent, **pp;
 212         const void *here = __builtin_return_address(0);
 213         int ret;
 214
 215         _enter("%p,%lx", rx, user_call_ID);
 216
 217         call = rxrpc_alloc_client_call(srx, gfp);
 218         if (IS_ERR(call)) {
 219                 _leave(" = %ld", PTR_ERR(call));
 220                 return call;
 221         }
 222
 223         trace_rxrpc_call(call, 0, atomic_read(&call->usage), here,
 224                          (const void *)user_call_ID);
 225
 226         /* Publish the call, even though it is incompletely set up as yet */
 227         call->user_call_ID = user_call_ID;
 228         __set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 229
 230         write_lock(&rx->call_lock);
 231
 232         pp = &rx->calls.rb_node;
 233         parent = NULL;
 234         while (*pp) {
 235                 parent = *pp;
 236                 xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 237
 238                 if (user_call_ID < xcall->user_call_ID)
 239                         pp = &(*pp)->rb_left;
 240                 else if (user_call_ID > xcall->user_call_ID)
 241                         pp = &(*pp)->rb_right;
 242                 else
 243                         goto found_user_ID_now_present;
 244         }
 245
 246         rcu_assign_pointer(call->socket, rx);
 247         rxrpc_get_call(call, rxrpc_call_got_userid);
 248         rb_link_node(&call->sock_node, parent, pp);
 249         rb_insert_color(&call->sock_node, &rx->calls);
 250         list_add(&call->sock_link, &rx->sock_calls);
 251
 252         write_unlock(&rx->call_lock);
 253
 254         write_lock(&rxrpc_call_lock);
 255         list_add_tail(&call->link, &rxrpc_calls);
 256         write_unlock(&rxrpc_call_lock);
 257
 258         /* Set up or get a connection record and set the protocol parameters,
 259          * including channel number and call ID.
 260          */
 261         ret = rxrpc_connect_call(call, cp, srx, gfp);
 262         if (ret < 0)
 263                 goto error;
 264
 265         spin_lock_bh(&call->conn->params.peer->lock);
 266         hlist_add_head(&call->error_link,
 267                        &call->conn->params.peer->error_targets);
 268         spin_unlock_bh(&call->conn->params.peer->lock);
 269
 270         rxrpc_start_call_timer(call);
 271
 272         _net("CALL new %d on CONN %d", call->debug_id, call->conn->debug_id);
 273
 274         _leave(" = %p [new]", call);
 275         return call;
 276
 277 error:
 278         write_lock(&rx->call_lock);
 279         rb_erase(&call->sock_node, &rx->calls);
 280         write_unlock(&rx->call_lock);
 281         rxrpc_put_call(call, rxrpc_call_put_userid);
 282
 283         write_lock(&rxrpc_call_lock);
 284         list_del_init(&call->link);
 285         write_unlock(&rxrpc_call_lock);
 286
 287 error_out:
 288         __rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 289                                     RX_CALL_DEAD, ret);
 290         set_bit(RXRPC_CALL_RELEASED, &call->flags);
 291         rxrpc_put_call(call, rxrpc_call_put);
 292         _leave(" = %d", ret);
 293         return ERR_PTR(ret);
 294
 295         /* We unexpectedly found the user ID in the list after taking
 296          * the call_lock.  This shouldn't happen unless the user races
 297          * with itself and tries to add the same user ID twice at the
 298          * same time in different threads.
 299          */
 300 found_user_ID_now_present:
 301         write_unlock(&rx->call_lock);
 302         ret = -EEXIST;
 303         goto error_out;
 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
 328         /* Set the channel for this call.  We don't get channel_lock as we're
 329          * only defending against the data_ready handler (which we're called
 330          * from) and the RESPONSE packet parser (which is only really
 331          * interested in call_counter and can cope with a disagreement with the
 332          * call pointer).
 333          */
 334         chan = sp->hdr.cid & RXRPC_CHANNELMASK;
 335         conn->channels[chan].call_counter = call->call_id;
 336         conn->channels[chan].call_id = call->call_id;
 337         rcu_assign_pointer(conn->channels[chan].call, call);
 338
 339         spin_lock(&conn->params.peer->lock);
 340         hlist_add_head(&call->error_link, &conn->params.peer->error_targets);
 341         spin_unlock(&conn->params.peer->lock);
 342
 343         _net("CALL incoming %d on CONN %d", call->debug_id, call->conn->debug_id);
 344
 345         rxrpc_start_call_timer(call);
 346         _leave("");
 347 }
 348
 349 /*
 350  * Queue a call's work processor, getting a ref to pass to the work queue.
 351  */
 352 bool rxrpc_queue_call(struct rxrpc_call *call)
 353 {
 354         const void *here = __builtin_return_address(0);
 355         int n = __atomic_add_unless(&call->usage, 1, 0);
 356         if (n == 0)
 357                 return false;
 358         if (rxrpc_queue_work(&call->processor))
 359                 trace_rxrpc_call(call, rxrpc_call_queued, n + 1, here, NULL);
 360         else
 361                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 362         return true;
 363 }
 364
 365 /*
 366  * Queue a call's work processor, passing the callers ref to the work queue.
 367  */
 368 bool __rxrpc_queue_call(struct rxrpc_call *call)
 369 {
 370         const void *here = __builtin_return_address(0);
 371         int n = atomic_read(&call->usage);
 372         ASSERTCMP(n, >=, 1);
 373         if (rxrpc_queue_work(&call->processor))
 374                 trace_rxrpc_call(call, rxrpc_call_queued_ref, n, here, NULL);
 375         else
 376                 rxrpc_put_call(call, rxrpc_call_put_noqueue);
 377         return true;
 378 }
 379
 380 /*
 381  * Note the re-emergence of a call.
 382  */
 383 void rxrpc_see_call(struct rxrpc_call *call)
 384 {
 385         const void *here = __builtin_return_address(0);
 386         if (call) {
 387                 int n = atomic_read(&call->usage);
 388
 389                 trace_rxrpc_call(call, rxrpc_call_seen, n, here, NULL);
 390         }
 391 }
 392
 393 /*
 394  * Note the addition of a ref on a call.
 395  */
 396 void rxrpc_get_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 397 {
 398         const void *here = __builtin_return_address(0);
 399         int n = atomic_inc_return(&call->usage);
 400
 401         trace_rxrpc_call(call, op, n, here, NULL);
 402 }
 403
 404 /*
 405  * Detach a call from its owning socket.
 406  */
 407 void rxrpc_release_call(struct rxrpc_sock *rx, struct rxrpc_call *call)
 408 {
 409         struct rxrpc_connection *conn = call->conn;
 410         bool put = false;
 411         int i;
 412
 413         _enter("{%d,%d}", call->debug_id, atomic_read(&call->usage));
 414
 415         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 416
 417         rxrpc_see_call(call);
 418
 419         spin_lock_bh(&call->lock);
 420         if (test_and_set_bit(RXRPC_CALL_RELEASED, &call->flags))
 421                 BUG();
 422         spin_unlock_bh(&call->lock);
 423
 424         del_timer_sync(&call->timer);
 425
 426         /* Make sure we don't get any more notifications */
 427         write_lock_bh(&rx->recvmsg_lock);
 428
 429         if (!list_empty(&call->recvmsg_link)) {
 430                 _debug("unlinking once-pending call %p { e=%lx f=%lx }",
 431                        call, call->events, call->flags);
 432                 list_del(&call->recvmsg_link);
 433                 put = true;
 434         }
 435
 436         /* list_empty() must return false in rxrpc_notify_socket() */
 437         call->recvmsg_link.next = NULL;
 438         call->recvmsg_link.prev = NULL;
 439
 440         write_unlock_bh(&rx->recvmsg_lock);
 441         if (put)
 442                 rxrpc_put_call(call, rxrpc_call_put);
 443
 444         write_lock(&rx->call_lock);
 445
 446         if (test_and_clear_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 447                 rb_erase(&call->sock_node, &rx->calls);
 448                 memset(&call->sock_node, 0xdd, sizeof(call->sock_node));
 449                 rxrpc_put_call(call, rxrpc_call_put_userid);
 450         }
 451
 452         list_del(&call->sock_link);
 453         write_unlock(&rx->call_lock);
 454
 455         _debug("RELEASE CALL %p (%d CONN %p)", call, call->debug_id, conn);
 456
 457         if (conn)
 458                 rxrpc_disconnect_call(call);
 459
 460         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++) {
 461                 rxrpc_free_skb(call->rxtx_buffer[i]);
 462                 call->rxtx_buffer[i] = NULL;
 463         }
 464
 465         /* We have to release the prealloc backlog ref */
 466         if (rxrpc_is_service_call(call))
 467                 rxrpc_put_call(call, rxrpc_call_put);
 468         _leave("");
 469 }
 470
 471 /*
 472  * release all the calls associated with a socket
 473  */
 474 void rxrpc_release_calls_on_socket(struct rxrpc_sock *rx)
 475 {
 476         struct rxrpc_call *call;
 477
 478         _enter("%p", rx);
 479
 480         while (!list_empty(&rx->sock_calls)) {
 481                 call = list_entry(rx->sock_calls.next,
 482                                   struct rxrpc_call, sock_link);
 483                 rxrpc_get_call(call, rxrpc_call_got);
 484                 rxrpc_abort_call("SKT", call, 0, RX_CALL_DEAD, ECONNRESET);
 485                 rxrpc_send_call_packet(call, RXRPC_PACKET_TYPE_ABORT);
 486                 rxrpc_release_call(rx, call);
 487                 rxrpc_put_call(call, rxrpc_call_put);
 488         }
 489
 490         _leave("");
 491 }
 492
 493 /*
 494  * release a call
 495  */
 496 void rxrpc_put_call(struct rxrpc_call *call, enum rxrpc_call_trace op)
 497 {
 498         const void *here = __builtin_return_address(0);
 499         int n;
 500
 501         ASSERT(call != NULL);
 502
 503         n = atomic_dec_return(&call->usage);
 504         trace_rxrpc_call(call, op, n, here, NULL);
 505         ASSERTCMP(n, >=, 0);
 506         if (n == 0) {
 507                 _debug("call %d dead", call->debug_id);
 508                 ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 509
 510                 write_lock(&rxrpc_call_lock);
 511                 list_del_init(&call->link);
 512                 write_unlock(&rxrpc_call_lock);
 513
 514                 rxrpc_cleanup_call(call);
 515         }
 516 }
 517
 518 /*
 519  * Final call destruction under RCU.
 520  */
 521 static void rxrpc_rcu_destroy_call(struct rcu_head *rcu)
 522 {
 523         struct rxrpc_call *call = container_of(rcu, struct rxrpc_call, rcu);
 524
 525         rxrpc_put_peer(call->peer);
 526         kfree(call->rxtx_buffer);
 527         kfree(call->rxtx_annotations);
 528         kmem_cache_free(rxrpc_call_jar, call);
 529 }
 530
 531 /*
 532  * clean up a call
 533  */
 534 void rxrpc_cleanup_call(struct rxrpc_call *call)
 535 {
 536         int i;
 537
 538         _net("DESTROY CALL %d", call->debug_id);
 539
 540         memset(&call->sock_node, 0xcd, sizeof(call->sock_node));
 541
 542         del_timer_sync(&call->timer);
 543
 544         ASSERTCMP(call->state, ==, RXRPC_CALL_COMPLETE);
 545         ASSERT(test_bit(RXRPC_CALL_RELEASED, &call->flags));
 546         ASSERTCMP(call->conn, ==, NULL);
 547
 548         /* Clean up the Rx/Tx buffer */
 549         for (i = 0; i < RXRPC_RXTX_BUFF_SIZE; i++)
 550                 rxrpc_free_skb(call->rxtx_buffer[i]);
 551
 552         rxrpc_free_skb(call->tx_pending);
 553
 554         call_rcu(&call->rcu, rxrpc_rcu_destroy_call);
 555 }
 556
 557 /*
 558  * Make sure that all calls are gone.
 559  */
 560 void __exit rxrpc_destroy_all_calls(void)
 561 {
 562         struct rxrpc_call *call;
 563
 564         _enter("");
 565
 566         if (list_empty(&rxrpc_calls))
 567                 return;
 568
 569         write_lock(&rxrpc_call_lock);
 570
 571         while (!list_empty(&rxrpc_calls)) {
 572                 call = list_entry(rxrpc_calls.next, struct rxrpc_call, link);
 573                 _debug("Zapping call %p", call);
 574
 575                 rxrpc_see_call(call);
 576                 list_del_init(&call->link);
 577
 578                 pr_err("Call %p still in use (%d,%s,%lx,%lx)!\n",
 579                        call, atomic_read(&call->usage),
 580                        rxrpc_call_states[call->state],
 581                        call->flags, call->events);
 582
 583                 write_unlock(&rxrpc_call_lock);
 584                 cond_resched();
 585                 write_lock(&rxrpc_call_lock);
 586         }
 587
 588         write_unlock(&rxrpc_call_lock);
 589 }