net/rxrpc/call_accept.c

   1 /* incoming 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/module.h>
  15 #include <linux/net.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/errqueue.h>
  18 #include <linux/udp.h>
  19 #include <linux/in.h>
  20 #include <linux/in6.h>
  21 #include <linux/icmp.h>
  22 #include <linux/gfp.h>
  23 #include <linux/circ_buf.h>
  24 #include <net/sock.h>
  25 #include <net/af_rxrpc.h>
  26 #include <net/ip.h>
  27 #include "ar-internal.h"
  28
  29 static void rxrpc_dummy_notify(struct sock *sk, struct rxrpc_call *call,
  30                                unsigned long user_call_ID)
  31 {
  32 }
  33
  34 /*
  35  * Preallocate a single service call, connection and peer and, if possible,
  36  * give them a user ID and attach the user's side of the ID to them.
  37  */
  38 static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx,
  39                                       struct rxrpc_backlog *b,
  40                                       rxrpc_notify_rx_t notify_rx,
  41                                       rxrpc_user_attach_call_t user_attach_call,
  42                                       unsigned long user_call_ID, gfp_t gfp)
  43 {
  44         const void *here = __builtin_return_address(0);
  45         struct rxrpc_call *call;
  46         int max, tmp;
  47         unsigned int size = RXRPC_BACKLOG_MAX;
  48         unsigned int head, tail, call_head, call_tail;
  49
  50         max = rx->sk.sk_max_ack_backlog;
  51         tmp = rx->sk.sk_ack_backlog;
  52         if (tmp >= max) {
  53                 _leave(" = -ENOBUFS [full %u]", max);
  54                 return -ENOBUFS;
  55         }
  56         max -= tmp;
  57
  58         /* We don't need more conns and peers than we have calls, but on the
  59          * other hand, we shouldn't ever use more peers than conns or conns
  60          * than calls.
  61          */
  62         call_head = b->call_backlog_head;
  63         call_tail = READ_ONCE(b->call_backlog_tail);
  64         tmp = CIRC_CNT(call_head, call_tail, size);
  65         if (tmp >= max) {
  66                 _leave(" = -ENOBUFS [enough %u]", tmp);
  67                 return -ENOBUFS;
  68         }
  69         max = tmp + 1;
  70
  71         head = b->peer_backlog_head;
  72         tail = READ_ONCE(b->peer_backlog_tail);
  73         if (CIRC_CNT(head, tail, size) < max) {
  74                 struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp);
  75                 if (!peer)
  76                         return -ENOMEM;
  77                 b->peer_backlog[head] = peer;
  78                 smp_store_release(&b->peer_backlog_head,
  79                                   (head + 1) & (size - 1));
  80         }
  81
  82         head = b->conn_backlog_head;
  83         tail = READ_ONCE(b->conn_backlog_tail);
  84         if (CIRC_CNT(head, tail, size) < max) {
  85                 struct rxrpc_connection *conn;
  86
  87                 conn = rxrpc_prealloc_service_connection(gfp);
  88                 if (!conn)
  89                         return -ENOMEM;
  90                 b->conn_backlog[head] = conn;
  91                 smp_store_release(&b->conn_backlog_head,
  92                                   (head + 1) & (size - 1));
  93
  94                 trace_rxrpc_conn(conn, rxrpc_conn_new_service,
  95                                  atomic_read(&conn->usage), here);
  96         }
  97
  98         /* Now it gets complicated, because calls get registered with the
  99          * socket here, particularly if a user ID is preassigned by the user.
 100          */
 101         call = rxrpc_alloc_call(gfp);
 102         if (!call)
 103                 return -ENOMEM;
 104         call->flags |= (1 << RXRPC_CALL_IS_SERVICE);
 105         call->state = RXRPC_CALL_SERVER_PREALLOC;
 106
 107         trace_rxrpc_call(call, rxrpc_call_new_service,
 108                          atomic_read(&call->usage),
 109                          here, (const void *)user_call_ID);
 110
 111         write_lock(&rx->call_lock);
 112         if (user_attach_call) {
 113                 struct rxrpc_call *xcall;
 114                 struct rb_node *parent, **pp;
 115
 116                 /* Check the user ID isn't already in use */
 117                 pp = &rx->calls.rb_node;
 118                 parent = NULL;
 119                 while (*pp) {
 120                         parent = *pp;
 121                         xcall = rb_entry(parent, struct rxrpc_call, sock_node);
 122                         if (user_call_ID < call->user_call_ID)
 123                                 pp = &(*pp)->rb_left;
 124                         else if (user_call_ID > call->user_call_ID)
 125                                 pp = &(*pp)->rb_right;
 126                         else
 127                                 goto id_in_use;
 128                 }
 129
 130                 call->user_call_ID = user_call_ID;
 131                 call->notify_rx = notify_rx;
 132                 rxrpc_get_call(call, rxrpc_call_got_kernel);
 133                 user_attach_call(call, user_call_ID);
 134                 rxrpc_get_call(call, rxrpc_call_got_userid);
 135                 rb_link_node(&call->sock_node, parent, pp);
 136                 rb_insert_color(&call->sock_node, &rx->calls);
 137                 set_bit(RXRPC_CALL_HAS_USERID, &call->flags);
 138         }
 139
 140         list_add(&call->sock_link, &rx->sock_calls);
 141
 142         write_unlock(&rx->call_lock);
 143
 144         write_lock(&rxrpc_call_lock);
 145         list_add_tail(&call->link, &rxrpc_calls);
 146         write_unlock(&rxrpc_call_lock);
 147
 148         b->call_backlog[call_head] = call;
 149         smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1));
 150         _leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID);
 151         return 0;
 152
 153 id_in_use:
 154         write_unlock(&rx->call_lock);
 155         rxrpc_cleanup_call(call);
 156         _leave(" = -EBADSLT");
 157         return -EBADSLT;
 158 }
 159
 160 /*
 161  * Preallocate sufficient service connections, calls and peers to cover the
 162  * entire backlog of a socket.  When a new call comes in, if we don't have
 163  * sufficient of each available, the call gets rejected as busy or ignored.
 164  *
 165  * The backlog is replenished when a connection is accepted or rejected.
 166  */
 167 int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp)
 168 {
 169         struct rxrpc_backlog *b = rx->backlog;
 170
 171         if (!b) {
 172                 b = kzalloc(sizeof(struct rxrpc_backlog), gfp);
 173                 if (!b)
 174                         return -ENOMEM;
 175                 rx->backlog = b;
 176         }
 177
 178         if (rx->discard_new_call)
 179                 return 0;
 180
 181         while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp) == 0)
 182                 ;
 183
 184         return 0;
 185 }
 186
 187 /*
 188  * Discard the preallocation on a service.
 189  */
 190 void rxrpc_discard_prealloc(struct rxrpc_sock *rx)
 191 {
 192         struct rxrpc_backlog *b = rx->backlog;
 193         unsigned int size = RXRPC_BACKLOG_MAX, head, tail;
 194
 195         if (!b)
 196                 return;
 197         rx->backlog = NULL;
 198
 199         /* Make sure that there aren't any incoming calls in progress before we
 200          * clear the preallocation buffers.
 201          */
 202         spin_lock_bh(&rx->incoming_lock);
 203         spin_unlock_bh(&rx->incoming_lock);
 204
 205         head = b->peer_backlog_head;
 206         tail = b->peer_backlog_tail;
 207         while (CIRC_CNT(head, tail, size) > 0) {
 208                 struct rxrpc_peer *peer = b->peer_backlog[tail];
 209                 kfree(peer);
 210                 tail = (tail + 1) & (size - 1);
 211         }
 212
 213         head = b->conn_backlog_head;
 214         tail = b->conn_backlog_tail;
 215         while (CIRC_CNT(head, tail, size) > 0) {
 216                 struct rxrpc_connection *conn = b->conn_backlog[tail];
 217                 write_lock(&rxrpc_connection_lock);
 218                 list_del(&conn->link);
 219                 list_del(&conn->proc_link);
 220                 write_unlock(&rxrpc_connection_lock);
 221                 kfree(conn);
 222                 tail = (tail + 1) & (size - 1);
 223         }
 224
 225         head = b->call_backlog_head;
 226         tail = b->call_backlog_tail;
 227         while (CIRC_CNT(head, tail, size) > 0) {
 228                 struct rxrpc_call *call = b->call_backlog[tail];
 229                 if (rx->discard_new_call) {
 230                         _debug("discard %lx", call->user_call_ID);
 231                         rx->discard_new_call(call, call->user_call_ID);
 232                         if (call->notify_rx)
 233                                 call->notify_rx = rxrpc_dummy_notify;
 234                         rxrpc_put_call(call, rxrpc_call_put_kernel);
 235                 }
 236                 rxrpc_call_completed(call);
 237                 rxrpc_release_call(rx, call);
 238                 rxrpc_put_call(call, rxrpc_call_put);
 239                 tail = (tail + 1) & (size - 1);
 240         }
 241
 242         kfree(b);
 243 }
 244
 245 /*
 246  * Allocate a new incoming call from the prealloc pool, along with a connection
 247  * and a peer as necessary.
 248  */
 249 static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx,
 250                                                     struct rxrpc_local *local,
 251                                                     struct rxrpc_connection *conn,
 252                                                     struct sk_buff *skb)
 253 {
 254         struct rxrpc_backlog *b = rx->backlog;
 255         struct rxrpc_peer *peer, *xpeer;
 256         struct rxrpc_call *call;
 257         unsigned short call_head, conn_head, peer_head;
 258         unsigned short call_tail, conn_tail, peer_tail;
 259         unsigned short call_count, conn_count;
 260
 261         /* #calls >= #conns >= #peers must hold true. */
 262         call_head = smp_load_acquire(&b->call_backlog_head);
 263         call_tail = b->call_backlog_tail;
 264         call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX);
 265         conn_head = smp_load_acquire(&b->conn_backlog_head);
 266         conn_tail = b->conn_backlog_tail;
 267         conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX);
 268         ASSERTCMP(conn_count, >=, call_count);
 269         peer_head = smp_load_acquire(&b->peer_backlog_head);
 270         peer_tail = b->peer_backlog_tail;
 271         ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=,
 272                   conn_count);
 273
 274         if (call_count == 0)
 275                 return NULL;
 276
 277         if (!conn) {
 278                 /* No connection.  We're going to need a peer to start off
 279                  * with.  If one doesn't yet exist, use a spare from the
 280                  * preallocation set.  We dump the address into the spare in
 281                  * anticipation - and to save on stack space.
 282                  */
 283                 xpeer = b->peer_backlog[peer_tail];
 284                 if (rxrpc_extract_addr_from_skb(&xpeer->srx, skb) < 0)
 285                         return NULL;
 286
 287                 peer = rxrpc_lookup_incoming_peer(local, xpeer);
 288                 if (peer == xpeer) {
 289                         b->peer_backlog[peer_tail] = NULL;
 290                         smp_store_release(&b->peer_backlog_tail,
 291                                           (peer_tail + 1) &
 292                                           (RXRPC_BACKLOG_MAX - 1));
 293                 }
 294
 295                 /* Now allocate and set up the connection */
 296                 conn = b->conn_backlog[conn_tail];
 297                 b->conn_backlog[conn_tail] = NULL;
 298                 smp_store_release(&b->conn_backlog_tail,
 299                                   (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
 300                 rxrpc_get_local(local);
 301                 conn->params.local = local;
 302                 conn->params.peer = peer;
 303                 rxrpc_see_connection(conn);
 304                 rxrpc_new_incoming_connection(conn, skb);
 305         } else {
 306                 rxrpc_get_connection(conn);
 307         }
 308
 309         /* And now we can allocate and set up a new call */
 310         call = b->call_backlog[call_tail];
 311         b->call_backlog[call_tail] = NULL;
 312         smp_store_release(&b->call_backlog_tail,
 313                           (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1));
 314
 315         rxrpc_see_call(call);
 316         call->conn = conn;
 317         call->peer = rxrpc_get_peer(conn->params.peer);
 318         return call;
 319 }
 320
 321 /*
 322  * Set up a new incoming call.  Called in BH context with the RCU read lock
 323  * held.
 324  *
 325  * If this is for a kernel service, when we allocate the call, it will have
 326  * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the
 327  * retainer ref obtained from the backlog buffer.  Prealloc calls for userspace
 328  * services only have the ref from the backlog buffer.  We want to pass this
 329  * ref to non-BH context to dispose of.
 330  *
 331  * If we want to report an error, we mark the skb with the packet type and
 332  * abort code and return NULL.
 333  */
 334 struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local,
 335                                            struct rxrpc_connection *conn,
 336                                            struct sk_buff *skb)
 337 {
 338         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 339         struct rxrpc_sock *rx;
 340         struct rxrpc_call *call;
 341         u16 service_id = sp->hdr.serviceId;
 342
 343         _enter("");
 344
 345         /* Get the socket providing the service */
 346         rx = rcu_dereference(local->service);
 347         if (rx && service_id == rx->srx.srx_service)
 348                 goto found_service;
 349
 350         trace_rxrpc_abort("INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
 351                           RX_INVALID_OPERATION, EOPNOTSUPP);
 352         skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
 353         skb->priority = RX_INVALID_OPERATION;
 354         _leave(" = NULL [service]");
 355         return NULL;
 356
 357 found_service:
 358         spin_lock(&rx->incoming_lock);
 359         if (rx->sk.sk_state == RXRPC_CLOSE) {
 360                 trace_rxrpc_abort("CLS", sp->hdr.cid, sp->hdr.callNumber,
 361                                   sp->hdr.seq, RX_INVALID_OPERATION, ESHUTDOWN);
 362                 skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT;
 363                 skb->priority = RX_INVALID_OPERATION;
 364                 _leave(" = NULL [close]");
 365                 call = NULL;
 366                 goto out;
 367         }
 368
 369         call = rxrpc_alloc_incoming_call(rx, local, conn, skb);
 370         if (!call) {
 371                 skb->mark = RXRPC_SKB_MARK_BUSY;
 372                 _leave(" = NULL [busy]");
 373                 call = NULL;
 374                 goto out;
 375         }
 376
 377         trace_rxrpc_receive(call, rxrpc_receive_incoming,
 378                             sp->hdr.serial, sp->hdr.seq);
 379
 380         /* Make the call live. */
 381         rxrpc_incoming_call(rx, call, skb);
 382         conn = call->conn;
 383
 384         if (rx->notify_new_call)
 385                 rx->notify_new_call(&rx->sk, call, call->user_call_ID);
 386         else
 387                 sk_acceptq_added(&rx->sk);
 388
 389         spin_lock(&conn->state_lock);
 390         switch (conn->state) {
 391         case RXRPC_CONN_SERVICE_UNSECURED:
 392                 conn->state = RXRPC_CONN_SERVICE_CHALLENGING;
 393                 set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events);
 394                 rxrpc_queue_conn(call->conn);
 395                 break;
 396
 397         case RXRPC_CONN_SERVICE:
 398                 write_lock(&call->state_lock);
 399                 if (rx->discard_new_call)
 400                         call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 401                 else
 402                         call->state = RXRPC_CALL_SERVER_ACCEPTING;
 403                 write_unlock(&call->state_lock);
 404                 break;
 405
 406         case RXRPC_CONN_REMOTELY_ABORTED:
 407                 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED,
 408                                           conn->remote_abort, ECONNABORTED);
 409                 break;
 410         case RXRPC_CONN_LOCALLY_ABORTED:
 411                 rxrpc_abort_call("CON", call, sp->hdr.seq,
 412                                  conn->local_abort, ECONNABORTED);
 413                 break;
 414         default:
 415                 BUG();
 416         }
 417         spin_unlock(&conn->state_lock);
 418
 419         if (call->state == RXRPC_CALL_SERVER_ACCEPTING)
 420                 rxrpc_notify_socket(call);
 421
 422         /* We have to discard the prealloc queue's ref here and rely on a
 423          * combination of the RCU read lock and refs held either by the socket
 424          * (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel
 425          * service to prevent the call from being deallocated too early.
 426          */
 427         rxrpc_put_call(call, rxrpc_call_put);
 428
 429         _leave(" = %p{%d}", call, call->debug_id);
 430 out:
 431         spin_unlock(&rx->incoming_lock);
 432         return call;
 433 }
 434
 435 /*
 436  * handle acceptance of a call by userspace
 437  * - assign the user call ID to the call at the front of the queue
 438  */
 439 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx,
 440                                      unsigned long user_call_ID,
 441                                      rxrpc_notify_rx_t notify_rx)
 442 {
 443         struct rxrpc_call *call;
 444         struct rb_node *parent, **pp;
 445         int ret;
 446
 447         _enter(",%lx", user_call_ID);
 448
 449         ASSERT(!irqs_disabled());
 450
 451         write_lock(&rx->call_lock);
 452
 453         if (list_empty(&rx->to_be_accepted)) {
 454                 write_unlock(&rx->call_lock);
 455                 kleave(" = -ENODATA [empty]");
 456                 return ERR_PTR(-ENODATA);
 457         }
 458
 459         /* check the user ID isn't already in use */
 460         pp = &rx->calls.rb_node;
 461         parent = NULL;
 462         while (*pp) {
 463                 parent = *pp;
 464                 call = rb_entry(parent, struct rxrpc_call, sock_node);
 465
 466                 if (user_call_ID < call->user_call_ID)
 467                         pp = &(*pp)->rb_left;
 468                 else if (user_call_ID > call->user_call_ID)
 469                         pp = &(*pp)->rb_right;
 470                 else
 471                         goto id_in_use;
 472         }
 473
 474         /* Dequeue the first call and check it's still valid.  We gain
 475          * responsibility for the queue's reference.
 476          */
 477         call = list_entry(rx->to_be_accepted.next,
 478                           struct rxrpc_call, accept_link);
 479         list_del_init(&call->accept_link);
 480         sk_acceptq_removed(&rx->sk);
 481         rxrpc_see_call(call);
 482
 483         write_lock_bh(&call->state_lock);
 484         switch (call->state) {
 485         case RXRPC_CALL_SERVER_ACCEPTING:
 486                 call->state = RXRPC_CALL_SERVER_RECV_REQUEST;
 487                 break;
 488         case RXRPC_CALL_COMPLETE:
 489                 ret = call->error;
 490                 goto out_release;
 491         default:
 492                 BUG();
 493         }
 494
 495         /* formalise the acceptance */
 496         call->notify_rx = notify_rx;
 497         call->user_call_ID = user_call_ID;
 498         rxrpc_get_call(call, rxrpc_call_got_userid);
 499         rb_link_node(&call->sock_node, parent, pp);
 500         rb_insert_color(&call->sock_node, &rx->calls);
 501         if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags))
 502                 BUG();
 503
 504         write_unlock_bh(&call->state_lock);
 505         write_unlock(&rx->call_lock);
 506         rxrpc_notify_socket(call);
 507         rxrpc_service_prealloc(rx, GFP_KERNEL);
 508         _leave(" = %p{%d}", call, call->debug_id);
 509         return call;
 510
 511 out_release:
 512         _debug("release %p", call);
 513         write_unlock_bh(&call->state_lock);
 514         write_unlock(&rx->call_lock);
 515         rxrpc_release_call(rx, call);
 516         rxrpc_put_call(call, rxrpc_call_put);
 517         goto out;
 518
 519 id_in_use:
 520         ret = -EBADSLT;
 521         write_unlock(&rx->call_lock);
 522 out:
 523         rxrpc_service_prealloc(rx, GFP_KERNEL);
 524         _leave(" = %d", ret);
 525         return ERR_PTR(ret);
 526 }
 527
 528 /*
 529  * Handle rejection of a call by userspace
 530  * - reject the call at the front of the queue
 531  */
 532 int rxrpc_reject_call(struct rxrpc_sock *rx)
 533 {
 534         struct rxrpc_call *call;
 535         bool abort = false;
 536         int ret;
 537
 538         _enter("");
 539
 540         ASSERT(!irqs_disabled());
 541
 542         write_lock(&rx->call_lock);
 543
 544         if (list_empty(&rx->to_be_accepted)) {
 545                 write_unlock(&rx->call_lock);
 546                 return -ENODATA;
 547         }
 548
 549         /* Dequeue the first call and check it's still valid.  We gain
 550          * responsibility for the queue's reference.
 551          */
 552         call = list_entry(rx->to_be_accepted.next,
 553                           struct rxrpc_call, accept_link);
 554         list_del_init(&call->accept_link);
 555         sk_acceptq_removed(&rx->sk);
 556         rxrpc_see_call(call);
 557
 558         write_lock_bh(&call->state_lock);
 559         switch (call->state) {
 560         case RXRPC_CALL_SERVER_ACCEPTING:
 561                 __rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, ECONNABORTED);
 562                 abort = true;
 563                 /* fall through */
 564         case RXRPC_CALL_COMPLETE:
 565                 ret = call->error;
 566                 goto out_discard;
 567         default:
 568                 BUG();
 569         }
 570
 571 out_discard:
 572         write_unlock_bh(&call->state_lock);
 573         write_unlock(&rx->call_lock);
 574         if (abort) {
 575                 rxrpc_send_abort_packet(call);
 576                 rxrpc_release_call(rx, call);
 577                 rxrpc_put_call(call, rxrpc_call_put);
 578         }
 579         rxrpc_service_prealloc(rx, GFP_KERNEL);
 580         _leave(" = %d", ret);
 581         return ret;
 582 }
 583
 584 /*
 585  * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls
 586  * @sock: The socket on which to preallocate
 587  * @notify_rx: Event notification function for the call
 588  * @user_attach_call: Func to attach call to user_call_ID
 589  * @user_call_ID: The tag to attach to the preallocated call
 590  * @gfp: The allocation conditions.
 591  *
 592  * Charge up the socket with preallocated calls, each with a user ID.  A
 593  * function should be provided to effect the attachment from the user's side.
 594  * The user is given a ref to hold on the call.
 595  *
 596  * Note that the call may be come connected before this function returns.
 597  */
 598 int rxrpc_kernel_charge_accept(struct socket *sock,
 599                                rxrpc_notify_rx_t notify_rx,
 600                                rxrpc_user_attach_call_t user_attach_call,
 601                                unsigned long user_call_ID, gfp_t gfp)
 602 {
 603         struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
 604         struct rxrpc_backlog *b = rx->backlog;
 605
 606         if (sock->sk->sk_state == RXRPC_CLOSE)
 607                 return -ESHUTDOWN;
 608
 609         return rxrpc_service_prealloc_one(rx, b, notify_rx,
 610                                           user_attach_call, user_call_ID,
 611                                           gfp);
 612 }
 613 EXPORT_SYMBOL(rxrpc_kernel_charge_accept);