net/rxrpc/call_accept.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* incoming call handling
   3  *
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/module.h>
  11 #include <linux/net.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/errqueue.h>
  14 #include <linux/udp.h>
  15 #include <linux/in.h>
  16 #include <linux/in6.h>
  17 #include <linux/icmp.h>
  18 #include <linux/gfp.h>
  19 #include <linux/circ_buf.h>
  20 #include <net/sock.h>
  21 #include <net/af_rxrpc.h>
  22 #include <net/ip.h>
  23 #include "ar-internal.h"
  24
  25 /*
  26  * Preallocate a single service call, connection and peer and, if possible,
  27  * give them a user ID and attach the user's side of the ID to them.
  28  */
  29 static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
  30                                       struct rxrpc_backlog *b,
  31                                       rxrpc_notify_rx_t notify_rx,
  32                                       rxrpc_user_attach_call_t user_attach_call,
  33                                       unsigned long user_call_ID, gfp_t gfp,
  34                                       unsigned int debug_id)
  35 {
  36         const void *here = __builtin_return_address(0);
  37         struct rxrpc_call *call;
  38         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
  39         int max, tmp;
  40         unsigned int size = RXRPC_BACKLOG_MAX;
  41         unsigned int head, tail, call_head, call_tail;
  42
  43         max = rx->sk.sk_max_ack_backlog;
  44         tmp = rx->sk.sk_ack_backlog;
  45         if (tmp >= max) {
  46                 _leave(" = -ENOBUFS [full %u]", max);
  47                 return -ENOBUFS;
  48         }
  49         max -= tmp;
  50
  51         /* We don't need more conns and peers than we have calls, but on the
  52          * other hand, we shouldn't ever use more peers than conns or conns
  53          * than calls.
  54          */
  55         call_head = b->call_backlog_head;
  56         call_tail = READ_ONCE(b->call_backlog_tail);
  57         tmp = CIRC_CNT(call_head, call_tail, size);
  58         if (tmp >= max) {
  59                 _leave(" = -ENOBUFS [enough %u]", tmp);
  60                 return -ENOBUFS;
  61         }
  62         max = tmp + 1;
  63
  64         head = b->peer_backlog_head;
  65         tail = READ_ONCE(b->peer_backlog_tail);
  66         if (CIRC_CNT(head, tail, size) < max) {
  67                 struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
  68                 if (!peer)
  69                         return -ENOMEM;
  70                 b->peer_backlog[head] = peer;
  71                 smp_store_release(&b->peer_backlog_head,
  72                                   (head + 1) & (size - 1));
  73         }
  74
  75         head = b->conn_backlog_head;
  76         tail = READ_ONCE(b->conn_backlog_tail);
  77         if (CIRC_CNT(head, tail, size) < max) {
  78                 struct rxrpc_connection *conn;
  79
  80                 conn = rxrpc_prealloc_service_connection(rxnet, gfp);
  81                 if (!conn)
  82                         return -ENOMEM;
  83                 b->conn_backlog[head] = conn;
  84                 smp_store_release(&b->conn_backlog_head,
  85                                   (head + 1) & (size - 1));
  86
  87                 trace_rxrpc_conn(conn->debug_id, rxrpc_conn_new_service,
  88                                  atomic_read(&conn->usage), here);
  89         }
  90
  91         /* Now it gets complicated, because calls get registered with the
  92          * socket here, particularly if a user ID is preassigned by the user.
  93          */
  94         call = rxrpc_alloc_call(rx, gfp, debug_id);
  95         if (!call)
  96                 return -ENOMEM;
  97         call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
  98         call->state = RXRPC_CALL_SERVER_PREALLOC;
  99
 100         trace_rxrpc_call(call->debug_id, rxrpc_call_new_service,
 101                          atomic_read(&call->usage),
 102                          here, (const void *)user_call_ID);
 103
 104         write_lock(&rx->call_lock);
 105         if (user_attach_call) {
 106                 struct rxrpc_call *xcall;
 107                 struct rb_node *parent, **pp;
 108
 109                 /* Check the user ID isn't already in use */
 110                 pp = &rx->calls.rb_node;
 111                 parent = NULL;
 112                 while (*pp) {
 113                         parent = *pp;
 114                         xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 115                         if (user_call_ID < xcall->user_call_ID)
 116                                 pp = &(*pp)->rb_left;
 117                         else if (user_call_ID > xcall->user_call_ID)
 118                                 pp = &(*pp)->rb_right;
 119                         else
 120                                 goto id_in_use;
 121                 }
 122
 123                 call->user_call_ID = user_call_ID;
 124                 call->notify_rx = notify_rx;
 125                 rxrpc_get_call(call, rxrpc_call_got_kernel);
 126                 user_attach_call(call, user_call_ID);
 127                 rxrpc_get_call(call, rxrpc_call_got_userid);
 128                 rb_link_node(&call->sock_node, parent, pp);
 129                 rb_insert_color(&call->sock_node, &rx->calls);
 130                 set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 131         }
 132
 133         list_add(&call->sock_link, &rx->sock_calls);
 134
 135         write_unlock(&rx->call_lock);
 136
 137         rxnet = call->rxnet;
 138         write_lock(&rxnet->call_lock);
 139         list_add_tail(&call->link, &rxnet->calls);
 140         write_unlock(&rxnet->call_lock);
 141
 142         b->call_backlog[call_head] = call;
 143         smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
 144         _leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
 145         return 0;
 146
 147 id_in_use:
 148         write_unlock(&rx->call_lock);
 149         rxrpc_cleanup_call(call);
 150         _leave(" = -EBADSLT");
 151         return -EBADSLT;
 152 }
 153
 154 /*
 155  * Preallocate sufficient service connections, calls and peers to cover the
 156  * entire backlog of a socket.  When a new call comes in, if we don't have
 157  * sufficient of each available, the call gets rejected as busy or ignored.
 158  *
 159  * The backlog is replenished when a connection is accepted or rejected.
 160  */
 161 int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
 162 {
 163         struct rxrpc_backlog *b = rx->backlog;
 164
 165         if (!b) {
 166                 b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
 167                 if (!b)
 168                         return -ENOMEM;
 169                 rx->backlog = b;
 170         }
 171
 172         if (rx->discard_new_call)
 173                 return 0;
 174
 175         while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp,
 176                                           atomic_inc_return(&rxrpc_debug_id)) == 0)
 177                 ;
 178
 179         return 0;
 180 }
 181
 182 /*
 183  * Discard the preallocation on a service.
 184  */
 185 void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
 186 {
 187         struct rxrpc_backlog *b = rx->backlog;
 188         struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk));
 189         unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
 190
 191         if (!b)
 192                 return;
 193         rx->backlog = NULL;
 194
 195         /* Make sure that there aren't any incoming calls in progress before we
 196          * clear the preallocation buffers.
 197          */
 198         spin_lock_bh(&rx->incoming_lock);
 199         spin_unlock_bh(&rx->incoming_lock);
 200
 201         head = b->peer_backlog_head;
 202         tail = b->peer_backlog_tail;
 203         while (CIRC_CNT(head, tail, size) > 0) {
 204                 struct rxrpc_peer *peer = b->peer_backlog[tail];
 205                 kfree(peer);
 206                 tail = (tail + 1) & (size - 1);
 207         }
 208
 209         head = b->conn_backlog_head;
 210         tail = b->conn_backlog_tail;
 211         while (CIRC_CNT(head, tail, size) > 0) {
 212                 struct rxrpc_connection *conn = b->conn_backlog[tail];
 213                 write_lock(&rxnet->conn_lock);
 214                 list_del(&conn->link);
 215                 list_del(&conn->proc_link);
 216                 write_unlock(&rxnet->conn_lock);
 217                 kfree(conn);
 218                 if (atomic_dec_and_test(&rxnet->nr_conns))
 219                         wake_up_var(&rxnet->nr_conns);
 220                 tail = (tail + 1) & (size - 1);
 221         }
 222
 223         head = b->call_backlog_head;
 224         tail = b->call_backlog_tail;
 225         while (CIRC_CNT(head, tail, size) > 0) {
 226                 struct rxrpc_call *call = b->call_backlog[tail];
 227                 rcu_assign_pointer(call->socket, rx);
 228                 if (rx->discard_new_call) {
 229                         _debug("discard %lx", call->user_call_ID);
 230                         rx->discard_new_call(call, call->user_call_ID);
 231                         rxrpc_put_call(call, rxrpc_call_put_kernel);
 232                 }
 233                 rxrpc_call_completed(call);
 234                 rxrpc_release_call(rx, call);
 235                 rxrpc_put_call(call, rxrpc_call_put);
 236                 tail = (tail + 1) & (size - 1);
 237         }
 238
 239         kfree(b);
 240 }
 241
 242 /*
 243  * Allocate a new incoming call from the prealloc pool, along with a connection
 244  * and a peer as necessary.
 245  */
 246 static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
 247                                                     struct rxrpc_local *local,
 248                                                     struct rxrpc_peer *peer,
 249                                                     struct rxrpc_connection *conn,
 250                                                     struct sk_buff *skb)
 251 {
 252         struct rxrpc_backlog *b = rx->backlog;
 253         struct rxrpc_call *call;
 254         unsigned short call_head, conn_head, peer_head;
 255         unsigned short call_tail, conn_tail, peer_tail;
 256         unsigned short call_count, conn_count;
 257
 258         /* #calls >= #conns >= #peers must hold true. */
 259         call_head = smp_load_acquire(&b->call_backlog_head);
 260         call_tail = b->call_backlog_tail;
 261         call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
 262         conn_head = smp_load_acquire(&b->conn_backlog_head);
 263         conn_tail = b->conn_backlog_tail;
 264         conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
 265         ASSERTCMP(conn_count, >=, call_count);
 266         peer_head = smp_load_acquire(&b->peer_backlog_head);
 267         peer_tail = b->peer_backlog_tail;
 268         ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
 269                   conn_count);
 270
 271         if (call_count == 0)
 272                 return NULL;
 273
 274         if (!conn) {
 275                 if (peer && !rxrpc_get_peer_maybe(peer))
 276                         peer = NULL;
 277                 if (!peer) {
 278                         peer = b->peer_backlog[peer_tail];
 279                         if (rxrpc_extract_addr_from_skb(&peer->srx, skb) < 0)
 280                                 return NULL;
 281                         b->peer_backlog[peer_tail] = NULL;
 282                         smp_store_release(&b->peer_backlog_tail,
 283                                           (peer_tail + 1) &
 284                                           (RXRPC_BACKLOG_MAX - 1));
 285
 286                         rxrpc_new_incoming_peer(rx, local, peer);
 287                 }
 288
 289                 /* Now allocate and set up the connection */
 290                 conn = b->conn_backlog[conn_tail];
 291                 b->conn_backlog[conn_tail] = NULL;
 292                 smp_store_release(&b->conn_backlog_tail,
 293                                   (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
 294                 conn->params.local = rxrpc_get_local(local);
 295                 conn->params.peer = peer;
 296                 rxrpc_see_connection(conn);
 297                 rxrpc_new_incoming_connection(rx, conn, skb);
 298         } else {
 299                 rxrpc_get_connection(conn);
 300         }
 301
 302         /* And now we can allocate and set up a new call */
 303         call = b->call_backlog[call_tail];
 304         b->call_backlog[call_tail] = NULL;
 305         smp_store_release(&b->call_backlog_tail,
 306                           (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
 307
 308         rxrpc_see_call(call);
 309         call->conn = conn;
 310         call->security = conn->security;
 311         call->peer = rxrpc_get_peer(conn->params.peer);
 312         call->cong_cwnd = call->peer->cong_cwnd;
 313         return call;
 314 }
 315
 316 /*
 317  * Set up a new incoming call.  Called in BH context with the RCU read lock
 318  * held.
 319  *
 320  * If this is for a kernel service, when we allocate the call, it will have
 321  * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
 322  * retainer ref obtained from the backlog buffer.  Prealloc calls for userspace
 323  * services only have the ref from the backlog buffer.  We want to pass this
 324  * ref to non-BH context to dispose of.
 325  *
 326  * If we want to report an error, we mark the skb with the packet type and
 327  * abort code and return NULL.
 328  *
 329  * The call is returned with the user access mutex held.
 330  */
 331 struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
 332                                            struct rxrpc_sock *rx,
 333                                            struct sk_buff *skb)
 334 {
 335         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 336         struct rxrpc_connection *conn;
 337         struct rxrpc_peer *peer = NULL;
 338         struct rxrpc_call *call;
 339
 340         _enter("");
 341
 342         spin_lock(&rx->incoming_lock);
 343         if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED ||
 344             rx->sk.sk_state == RXRPC_CLOSE) {
 345                 trace_rxrpc_abort(0, "CLS", sp->hdr.cid, sp->hdr.callNumber,
 346                                   sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
 347                 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
 348                 skb->priority = RX_INVALID_OPERATION;
 349                 _leave(" = NULL [close]");
 350                 call = NULL;
 351                 goto out;
 352         }
 353
 354         /* The peer, connection and call may all have sprung into existence due
 355          * to a duplicate packet being handled on another CPU in parallel, so
 356          * we have to recheck the routing.  However, we're now holding
 357          * rx->incoming_lock, so the values should remain stable.
 358          */
 359         conn = rxrpc_find_connection_rcu(local, skb, &peer);
 360
 361         call = rxrpc_alloc_incoming_call(rx, local, peer, conn, skb);
 362         if (!call) {
 363                 skb->mark = RXRPC_SKB_MARK_REJECT_BUSY;
 364                 _leave(" = NULL [busy]");
 365                 call = NULL;
 366                 goto out;
 367         }
 368
 369         trace_rxrpc_receive(call, rxrpc_receive_incoming,
 370                             sp->hdr.serial, sp->hdr.seq);
 371
 372         /* Lock the call to prevent rxrpc_kernel_send/recv_data() and
 373          * sendmsg()/recvmsg() inconveniently stealing the mutex once the
 374          * notification is generated.
 375          *
 376          * The BUG should never happen because the kernel should be well
 377          * behaved enough not to access the call before the first notification
 378          * event and userspace is prevented from doing so until the state is
 379          * appropriate.
 380          */
 381         if (!mutex_trylock(&call->user_mutex))
 382                 BUG();
 383
 384         /* Make the call live. */
 385         rxrpc_incoming_call(rx, call, skb);
 386         conn = call->conn;
 387
 388         if (rx->notify_new_call)
 389                 rx->notify_new_call(&rx->sk, call, call->user_call_ID);
 390         else
 391                 sk_acceptq_added(&rx->sk);
 392
 393         spin_lock(&conn->state_lock);
 394         switch (conn->state) {
 395         case RXRPC_CONN_SERVICE_UNSECURED:
 396                 conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
 397                 set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
 398                 rxrpc_queue_conn(call->conn);
 399                 break;
 400
 401         case RXRPC_CONN_SERVICE:
 402                 write_lock(&call->state_lock);
 403                 if (call->state < RXRPC_CALL_COMPLETE) {
 404                         if (rx->discard_new_call)
 405                                 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 406                         else
 407                                 call->state = RXRPC_CALL_SERVER_ACCEPTING;
 408                 }
 409                 write_unlock(&call->state_lock);
 410                 break;
 411
 412         case RXRPC_CONN_REMOTELY_ABORTED:
 413                 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
 414                                           conn->abort_code, conn->error);
 415                 break;
 416         case RXRPC_CONN_LOCALLY_ABORTED:
 417                 rxrpc_abort_call("CON", call, sp->hdr.seq,
 418                                  conn->abort_code, conn->error);
 419                 break;
 420         default:
 421                 BUG();
 422         }
 423         spin_unlock(&conn->state_lock);
 424
 425         if (call->state == RXRPC_CALL_SERVER_ACCEPTING)
 426                 rxrpc_notify_socket(call);
 427
 428         /* We have to discard the prealloc queue's ref here and rely on a
 429          * combination of the RCU read lock and refs held either by the socket
 430          * (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel
 431          * service to prevent the call from being deallocated too early.
 432          */
 433         rxrpc_put_call(call, rxrpc_call_put);
 434
 435         _leave(" = %p{%d}", call, call->debug_id);
 436 out:
 437         spin_unlock(&rx->incoming_lock);
 438         return call;
 439 }
 440
 441 /*
 442  * handle acceptance of a call by userspace
 443  * - assign the user call ID to the call at the front of the queue
 444  * - called with the socket locked.
 445  */
 446 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
 447                                      unsigned long user_call_ID,
 448                                      rxrpc_notify_rx_t notify_rx)
 449         __releases(&rx->sk.sk_lock.slock)
 450         __acquires(call->user_mutex)
 451 {
 452         struct rxrpc_call *call;
 453         struct rb_node *parent, **pp;
 454         int ret;
 455
 456         _enter(",%lx", user_call_ID);
 457
 458         ASSERT(!irqs_disabled());
 459
 460         write_lock(&rx->call_lock);
 461
 462         if (list_empty(&rx->to_be_accepted)) {
 463                 write_unlock(&rx->call_lock);
 464                 release_sock(&rx->sk);
 465                 kleave(" = -ENODATA [empty]");
 466                 return ERR_PTR(-ENODATA);
 467         }
 468
 469         /* check the user ID isn't already in use */
 470         pp = &rx->calls.rb_node;
 471         parent = NULL;
 472         while (*pp) {
 473                 parent = *pp;
 474                 call = rb_entry(parent, struct rxrpc_call, sock_node);
 475
 476                 if (user_call_ID < call->user_call_ID)
 477                         pp = &(*pp)->rb_left;
 478                 else if (user_call_ID > call->user_call_ID)
 479                         pp = &(*pp)->rb_right;
 480                 else
 481                         goto id_in_use;
 482         }
 483
 484         /* Dequeue the first call and check it's still valid.  We gain
 485          * responsibility for the queue's reference.
 486          */
 487         call = list_entry(rx->to_be_accepted.next,
 488                           struct rxrpc_call, accept_link);
 489         write_unlock(&rx->call_lock);
 490
 491         /* We need to gain the mutex from the interrupt handler without
 492          * upsetting lockdep, so we have to release it there and take it here.
 493          * We are, however, still holding the socket lock, so other accepts
 494          * must wait for us and no one can add the user ID behind our backs.
 495          */
 496         if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 497                 release_sock(&rx->sk);
 498                 kleave(" = -ERESTARTSYS");
 499                 return ERR_PTR(-ERESTARTSYS);
 500         }
 501
 502         write_lock(&rx->call_lock);
 503         list_del_init(&call->accept_link);
 504         sk_acceptq_removed(&rx->sk);
 505         rxrpc_see_call(call);
 506
 507         /* Find the user ID insertion point. */
 508         pp = &rx->calls.rb_node;
 509         parent = NULL;
 510         while (*pp) {
 511                 parent = *pp;
 512                 call = rb_entry(parent, struct rxrpc_call, sock_node);
 513
 514                 if (user_call_ID < call->user_call_ID)
 515                         pp = &(*pp)->rb_left;
 516                 else if (user_call_ID > call->user_call_ID)
 517                         pp = &(*pp)->rb_right;
 518                 else
 519                         BUG();
 520         }
 521
 522         write_lock_bh(&call->state_lock);
 523         switch (call->state) {
 524         case RXRPC_CALL_SERVER_ACCEPTING:
 525                 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 526                 break;
 527         case RXRPC_CALL_COMPLETE:
 528                 ret = call->error;
 529                 goto out_release;
 530         default:
 531                 BUG();
 532         }
 533
 534         /* formalise the acceptance */
 535         call->notify_rx = notify_rx;
 536         call->user_call_ID = user_call_ID;
 537         rxrpc_get_call(call, rxrpc_call_got_userid);
 538         rb_link_node(&call->sock_node, parent, pp);
 539         rb_insert_color(&call->sock_node, &rx->calls);
 540         if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
 541                 BUG();
 542
 543         write_unlock_bh(&call->state_lock);
 544         write_unlock(&rx->call_lock);
 545         rxrpc_notify_socket(call);
 546         rxrpc_service_prealloc(rx, GFP_KERNEL);
 547         release_sock(&rx->sk);
 548         _leave(" = %p{%d}", call, call->debug_id);
 549         return call;
 550
 551 out_release:
 552         _debug("release %p", call);
 553         write_unlock_bh(&call->state_lock);
 554         write_unlock(&rx->call_lock);
 555         rxrpc_release_call(rx, call);
 556         rxrpc_put_call(call, rxrpc_call_put);
 557         goto out;
 558
 559 id_in_use:
 560         ret = -EBADSLT;
 561         write_unlock(&rx->call_lock);
 562 out:
 563         rxrpc_service_prealloc(rx, GFP_KERNEL);
 564         release_sock(&rx->sk);
 565         _leave(" = %d", ret);
 566         return ERR_PTR(ret);
 567 }
 568
 569 /*
 570  * Handle rejection of a call by userspace
 571  * - reject the call at the front of the queue
 572  */
 573 int rxrpc_reject_call(struct rxrpc_sock *rx)
 574 {
 575         struct rxrpc_call *call;
 576         bool abort = false;
 577         int ret;
 578
 579         _enter("");
 580
 581         ASSERT(!irqs_disabled());
 582
 583         write_lock(&rx->call_lock);
 584
 585         if (list_empty(&rx->to_be_accepted)) {
 586                 write_unlock(&rx->call_lock);
 587                 return -ENODATA;
 588         }
 589
 590         /* Dequeue the first call and check it's still valid.  We gain
 591          * responsibility for the queue's reference.
 592          */
 593         call = list_entry(rx->to_be_accepted.next,
 594                           struct rxrpc_call, accept_link);
 595         list_del_init(&call->accept_link);
 596         sk_acceptq_removed(&rx->sk);
 597         rxrpc_see_call(call);
 598
 599         write_lock_bh(&call->state_lock);
 600         switch (call->state) {
 601         case RXRPC_CALL_SERVER_ACCEPTING:
 602                 __rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, -ECONNABORTED);
 603                 abort = true;
 604                 /* fall through */
 605         case RXRPC_CALL_COMPLETE:
 606                 ret = call->error;
 607                 goto out_discard;
 608         default:
 609                 BUG();
 610         }
 611
 612 out_discard:
 613         write_unlock_bh(&call->state_lock);
 614         write_unlock(&rx->call_lock);
 615         if (abort) {
 616                 rxrpc_send_abort_packet(call);
 617                 rxrpc_release_call(rx, call);
 618                 rxrpc_put_call(call, rxrpc_call_put);
 619         }
 620         rxrpc_service_prealloc(rx, GFP_KERNEL);
 621         _leave(" = %d", ret);
 622         return ret;
 623 }
 624
 625 /*
 626  * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
 627  * @sock: The socket on which to preallocate
 628  * @notify_rx: Event notification function for the call
 629  * @user_attach_call: Func to attach call to user_call_ID
 630  * @user_call_ID: The tag to attach to the preallocated call
 631  * @gfp: The allocation conditions.
 632  * @debug_id: The tracing debug ID.
 633  *
 634  * Charge up the socket with preallocated calls, each with a user ID.  A
 635  * function should be provided to effect the attachment from the user's side.
 636  * The user is given a ref to hold on the call.
 637  *
 638  * Note that the call may be come connected before this function returns.
 639  */
 640 int rxrpc_kernel_charge_accept(struct socket *sock,
 641                                rxrpc_notify_rx_t notify_rx,
 642                                rxrpc_user_attach_call_t user_attach_call,
 643                                unsigned long user_call_ID, gfp_t gfp,
 644                                unsigned int debug_id)
 645 {
 646         struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
 647         struct rxrpc_backlog *b = rx->backlog;
 648
 649         if (sock->sk->sk_state == RXRPC_CLOSE)
 650                 return -ESHUTDOWN;
 651
 652         return rxrpc_service_prealloc_one(rx, b, notify_rx,
 653                                           user_attach_call, user_call_ID,
 654                                           gfp, debug_id);
 655 }
 656 EXPORT_SYMBOL(rxrpc_kernel_charge_accept);