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 /* 30 * Preallocate a single service call, connection and peer and, if possible, 31 * give them a user ID and attach the user's side of the ID to them. 32 */ 33 static int rxrpc_service_prealloc_one(struct rxrpc_sock *rx, 34 struct rxrpc_backlog *b, 35 rxrpc_notify_rx_t notify_rx, 36 rxrpc_user_attach_call_t user_attach_call, 37 unsigned long user_call_ID, gfp_t gfp) 38 { 39 const void *here = __builtin_return_address(0); 40 struct rxrpc_call *call; 41 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk)); 42 int max, tmp; 43 unsigned int size = RXRPC_BACKLOG_MAX; 44 unsigned int head, tail, call_head, call_tail; 45 46 max = rx->sk.sk_max_ack_backlog; 47 tmp = rx->sk.sk_ack_backlog; 48 if (tmp >= max) { 49 _leave(" = -ENOBUFS [full %u]", max); 50 return -ENOBUFS; 51 } 52 max -= tmp; 53 54 /* We don't need more conns and peers than we have calls, but on the 55 * other hand, we shouldn't ever use more peers than conns or conns 56 * than calls. 57 */ 58 call_head = b->call_backlog_head; 59 call_tail = READ_ONCE(b->call_backlog_tail); 60 tmp = CIRC_CNT(call_head, call_tail, size); 61 if (tmp >= max) { 62 _leave(" = -ENOBUFS [enough %u]", tmp); 63 return -ENOBUFS; 64 } 65 max = tmp + 1; 66 67 head = b->peer_backlog_head; 68 tail = READ_ONCE(b->peer_backlog_tail); 69 if (CIRC_CNT(head, tail, size) < max) { 70 struct rxrpc_peer *peer = rxrpc_alloc_peer(rx->local, gfp); 71 if (!peer) 72 return -ENOMEM; 73 b->peer_backlog[head] = peer; 74 smp_store_release(&b->peer_backlog_head, 75 (head + 1) & (size - 1)); 76 } 77 78 head = b->conn_backlog_head; 79 tail = READ_ONCE(b->conn_backlog_tail); 80 if (CIRC_CNT(head, tail, size) < max) { 81 struct rxrpc_connection *conn; 82 83 conn = rxrpc_prealloc_service_connection(rxnet, gfp); 84 if (!conn) 85 return -ENOMEM; 86 b->conn_backlog[head] = conn; 87 smp_store_release(&b->conn_backlog_head, 88 (head + 1) & (size - 1)); 89 90 trace_rxrpc_conn(conn, rxrpc_conn_new_service, 91 atomic_read(&conn->usage), here); 92 } 93 94 /* Now it gets complicated, because calls get registered with the 95 * socket here, particularly if a user ID is preassigned by the user. 96 */ 97 call = rxrpc_alloc_call(gfp); 98 if (!call) 99 return -ENOMEM; 100 call->flags |= (1 << RXRPC_CALL_IS_SERVICE); 101 call->state = RXRPC_CALL_SERVER_PREALLOC; 102 103 trace_rxrpc_call(call, rxrpc_call_new_service, 104 atomic_read(&call->usage), 105 here, (const void *)user_call_ID); 106 107 write_lock(&rx->call_lock); 108 if (user_attach_call) { 109 struct rxrpc_call *xcall; 110 struct rb_node *parent, **pp; 111 112 /* Check the user ID isn't already in use */ 113 pp = &rx->calls.rb_node; 114 parent = NULL; 115 while (*pp) { 116 parent = *pp; 117 xcall = rb_entry(parent, struct rxrpc_call, sock_node); 118 if (user_call_ID < call->user_call_ID) 119 pp = &(*pp)->rb_left; 120 else if (user_call_ID > call->user_call_ID) 121 pp = &(*pp)->rb_right; 122 else 123 goto id_in_use; 124 } 125 126 call->user_call_ID = user_call_ID; 127 call->notify_rx = notify_rx; 128 rxrpc_get_call(call, rxrpc_call_got_kernel); 129 user_attach_call(call, user_call_ID); 130 rxrpc_get_call(call, rxrpc_call_got_userid); 131 rb_link_node(&call->sock_node, parent, pp); 132 rb_insert_color(&call->sock_node, &rx->calls); 133 set_bit(RXRPC_CALL_HAS_USERID, &call->flags); 134 } 135 136 list_add(&call->sock_link, &rx->sock_calls); 137 138 write_unlock(&rx->call_lock); 139 140 write_lock(&rxnet->call_lock); 141 list_add_tail(&call->link, &rxnet->calls); 142 write_unlock(&rxnet->call_lock); 143 144 b->call_backlog[call_head] = call; 145 smp_store_release(&b->call_backlog_head, (call_head + 1) & (size - 1)); 146 _leave(" = 0 [%d -> %lx]", call->debug_id, user_call_ID); 147 return 0; 148 149 id_in_use: 150 write_unlock(&rx->call_lock); 151 rxrpc_cleanup_call(call); 152 _leave(" = -EBADSLT"); 153 return -EBADSLT; 154 } 155 156 /* 157 * Preallocate sufficient service connections, calls and peers to cover the 158 * entire backlog of a socket. When a new call comes in, if we don't have 159 * sufficient of each available, the call gets rejected as busy or ignored. 160 * 161 * The backlog is replenished when a connection is accepted or rejected. 162 */ 163 int rxrpc_service_prealloc(struct rxrpc_sock *rx, gfp_t gfp) 164 { 165 struct rxrpc_backlog *b = rx->backlog; 166 167 if (!b) { 168 b = kzalloc(sizeof(struct rxrpc_backlog), gfp); 169 if (!b) 170 return -ENOMEM; 171 rx->backlog = b; 172 } 173 174 if (rx->discard_new_call) 175 return 0; 176 177 while (rxrpc_service_prealloc_one(rx, b, NULL, NULL, 0, gfp) == 0) 178 ; 179 180 return 0; 181 } 182 183 /* 184 * Discard the preallocation on a service. 185 */ 186 void rxrpc_discard_prealloc(struct rxrpc_sock *rx) 187 { 188 struct rxrpc_backlog *b = rx->backlog; 189 struct rxrpc_net *rxnet = rxrpc_net(sock_net(&rx->sk)); 190 unsigned int size = RXRPC_BACKLOG_MAX, head, tail; 191 192 if (!b) 193 return; 194 rx->backlog = NULL; 195 196 /* Make sure that there aren't any incoming calls in progress before we 197 * clear the preallocation buffers. 198 */ 199 spin_lock_bh(&rx->incoming_lock); 200 spin_unlock_bh(&rx->incoming_lock); 201 202 head = b->peer_backlog_head; 203 tail = b->peer_backlog_tail; 204 while (CIRC_CNT(head, tail, size) > 0) { 205 struct rxrpc_peer *peer = b->peer_backlog[tail]; 206 kfree(peer); 207 tail = (tail + 1) & (size - 1); 208 } 209 210 head = b->conn_backlog_head; 211 tail = b->conn_backlog_tail; 212 while (CIRC_CNT(head, tail, size) > 0) { 213 struct rxrpc_connection *conn = b->conn_backlog[tail]; 214 write_lock(&rxnet->conn_lock); 215 list_del(&conn->link); 216 list_del(&conn->proc_link); 217 write_unlock(&rxnet->conn_lock); 218 kfree(conn); 219 tail = (tail + 1) & (size - 1); 220 } 221 222 head = b->call_backlog_head; 223 tail = b->call_backlog_tail; 224 while (CIRC_CNT(head, tail, size) > 0) { 225 struct rxrpc_call *call = b->call_backlog[tail]; 226 if (rx->discard_new_call) { 227 _debug("discard %lx", call->user_call_ID); 228 rx->discard_new_call(call, call->user_call_ID); 229 rxrpc_put_call(call, rxrpc_call_put_kernel); 230 } 231 rxrpc_call_completed(call); 232 rxrpc_release_call(rx, call); 233 rxrpc_put_call(call, rxrpc_call_put); 234 tail = (tail + 1) & (size - 1); 235 } 236 237 kfree(b); 238 } 239 240 /* 241 * Allocate a new incoming call from the prealloc pool, along with a connection 242 * and a peer as necessary. 243 */ 244 static struct rxrpc_call *rxrpc_alloc_incoming_call(struct rxrpc_sock *rx, 245 struct rxrpc_local *local, 246 struct rxrpc_connection *conn, 247 struct sk_buff *skb) 248 { 249 struct rxrpc_backlog *b = rx->backlog; 250 struct rxrpc_peer *peer, *xpeer; 251 struct rxrpc_call *call; 252 unsigned short call_head, conn_head, peer_head; 253 unsigned short call_tail, conn_tail, peer_tail; 254 unsigned short call_count, conn_count; 255 256 /* #calls >= #conns >= #peers must hold true. */ 257 call_head = smp_load_acquire(&b->call_backlog_head); 258 call_tail = b->call_backlog_tail; 259 call_count = CIRC_CNT(call_head, call_tail, RXRPC_BACKLOG_MAX); 260 conn_head = smp_load_acquire(&b->conn_backlog_head); 261 conn_tail = b->conn_backlog_tail; 262 conn_count = CIRC_CNT(conn_head, conn_tail, RXRPC_BACKLOG_MAX); 263 ASSERTCMP(conn_count, >=, call_count); 264 peer_head = smp_load_acquire(&b->peer_backlog_head); 265 peer_tail = b->peer_backlog_tail; 266 ASSERTCMP(CIRC_CNT(peer_head, peer_tail, RXRPC_BACKLOG_MAX), >=, 267 conn_count); 268 269 if (call_count == 0) 270 return NULL; 271 272 if (!conn) { 273 /* No connection. We're going to need a peer to start off 274 * with. If one doesn't yet exist, use a spare from the 275 * preallocation set. We dump the address into the spare in 276 * anticipation - and to save on stack space. 277 */ 278 xpeer = b->peer_backlog[peer_tail]; 279 if (rxrpc_extract_addr_from_skb(&xpeer->srx, skb) < 0) 280 return NULL; 281 282 peer = rxrpc_lookup_incoming_peer(local, xpeer); 283 if (peer == xpeer) { 284 b->peer_backlog[peer_tail] = NULL; 285 smp_store_release(&b->peer_backlog_tail, 286 (peer_tail + 1) & 287 (RXRPC_BACKLOG_MAX - 1)); 288 } 289 290 /* Now allocate and set up the connection */ 291 conn = b->conn_backlog[conn_tail]; 292 b->conn_backlog[conn_tail] = NULL; 293 smp_store_release(&b->conn_backlog_tail, 294 (conn_tail + 1) & (RXRPC_BACKLOG_MAX - 1)); 295 rxrpc_get_local(local); 296 conn->params.local = local; 297 conn->params.peer = peer; 298 rxrpc_see_connection(conn); 299 rxrpc_new_incoming_connection(rx, conn, skb); 300 } else { 301 rxrpc_get_connection(conn); 302 } 303 304 /* And now we can allocate and set up a new call */ 305 call = b->call_backlog[call_tail]; 306 b->call_backlog[call_tail] = NULL; 307 smp_store_release(&b->call_backlog_tail, 308 (call_tail + 1) & (RXRPC_BACKLOG_MAX - 1)); 309 310 rxrpc_see_call(call); 311 call->conn = conn; 312 call->peer = rxrpc_get_peer(conn->params.peer); 313 call->cong_cwnd = call->peer->cong_cwnd; 314 return call; 315 } 316 317 /* 318 * Set up a new incoming call. Called in BH context with the RCU read lock 319 * held. 320 * 321 * If this is for a kernel service, when we allocate the call, it will have 322 * three refs on it: (1) the kernel service, (2) the user_call_ID tree, (3) the 323 * retainer ref obtained from the backlog buffer. Prealloc calls for userspace 324 * services only have the ref from the backlog buffer. We want to pass this 325 * ref to non-BH context to dispose of. 326 * 327 * If we want to report an error, we mark the skb with the packet type and 328 * abort code and return NULL. 329 * 330 * The call is returned with the user access mutex held. 331 */ 332 struct rxrpc_call *rxrpc_new_incoming_call(struct rxrpc_local *local, 333 struct rxrpc_connection *conn, 334 struct sk_buff *skb) 335 { 336 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 337 struct rxrpc_sock *rx; 338 struct rxrpc_call *call; 339 u16 service_id = sp->hdr.serviceId; 340 341 _enter(""); 342 343 /* Get the socket providing the service */ 344 rx = rcu_dereference(local->service); 345 if (rx && (service_id == rx->srx.srx_service || 346 service_id == rx->second_service)) 347 goto found_service; 348 349 trace_rxrpc_abort("INV", sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq, 350 RX_INVALID_OPERATION, EOPNOTSUPP); 351 skb->mark = RXRPC_SKB_MARK_LOCAL_ABORT; 352 skb->priority = RX_INVALID_OPERATION; 353 _leave(" = NULL [service]"); 354 return NULL; 355 356 found_service: 357 spin_lock(&rx->incoming_lock); 358 if (rx->sk.sk_state == RXRPC_SERVER_LISTEN_DISABLED || 359 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 /* Lock the call to prevent rxrpc_kernel_send/recv_data() and 381 * sendmsg()/recvmsg() inconveniently stealing the mutex once the 382 * notification is generated. 383 * 384 * The BUG should never happen because the kernel should be well 385 * behaved enough not to access the call before the first notification 386 * event and userspace is prevented from doing so until the state is 387 * appropriate. 388 */ 389 if (!mutex_trylock(&call->user_mutex)) 390 BUG(); 391 392 /* Make the call live. */ 393 rxrpc_incoming_call(rx, call, skb); 394 conn = call->conn; 395 396 if (rx->notify_new_call) 397 rx->notify_new_call(&rx->sk, call, call->user_call_ID); 398 else 399 sk_acceptq_added(&rx->sk); 400 401 spin_lock(&conn->state_lock); 402 switch (conn->state) { 403 case RXRPC_CONN_SERVICE_UNSECURED: 404 conn->state = RXRPC_CONN_SERVICE_CHALLENGING; 405 set_bit(RXRPC_CONN_EV_CHALLENGE, &call->conn->events); 406 rxrpc_queue_conn(call->conn); 407 break; 408 409 case RXRPC_CONN_SERVICE: 410 write_lock(&call->state_lock); 411 if (rx->discard_new_call) 412 call->state = RXRPC_CALL_SERVER_RECV_REQUEST; 413 else 414 call->state = RXRPC_CALL_SERVER_ACCEPTING; 415 write_unlock(&call->state_lock); 416 break; 417 418 case RXRPC_CONN_REMOTELY_ABORTED: 419 rxrpc_set_call_completion(call, RXRPC_CALL_REMOTELY_ABORTED, 420 conn->remote_abort, -ECONNABORTED); 421 break; 422 case RXRPC_CONN_LOCALLY_ABORTED: 423 rxrpc_abort_call("CON", call, sp->hdr.seq, 424 conn->local_abort, -ECONNABORTED); 425 break; 426 default: 427 BUG(); 428 } 429 spin_unlock(&conn->state_lock); 430 431 if (call->state == RXRPC_CALL_SERVER_ACCEPTING) 432 rxrpc_notify_socket(call); 433 434 /* We have to discard the prealloc queue's ref here and rely on a 435 * combination of the RCU read lock and refs held either by the socket 436 * (recvmsg queue, to-be-accepted queue or user ID tree) or the kernel 437 * service to prevent the call from being deallocated too early. 438 */ 439 rxrpc_put_call(call, rxrpc_call_put); 440 441 _leave(" = %p{%d}", call, call->debug_id); 442 out: 443 spin_unlock(&rx->incoming_lock); 444 return call; 445 } 446 447 /* 448 * handle acceptance of a call by userspace 449 * - assign the user call ID to the call at the front of the queue 450 * - called with the socket locked. 451 */ 452 struct rxrpc_call *rxrpc_accept_call(struct rxrpc_sock *rx, 453 unsigned long user_call_ID, 454 rxrpc_notify_rx_t notify_rx) 455 __releases(&rx->sk.sk_lock.slock) 456 { 457 struct rxrpc_call *call; 458 struct rb_node *parent, **pp; 459 int ret; 460 461 _enter(",%lx", user_call_ID); 462 463 ASSERT(!irqs_disabled()); 464 465 write_lock(&rx->call_lock); 466 467 if (list_empty(&rx->to_be_accepted)) { 468 write_unlock(&rx->call_lock); 469 release_sock(&rx->sk); 470 kleave(" = -ENODATA [empty]"); 471 return ERR_PTR(-ENODATA); 472 } 473 474 /* check the user ID isn't already in use */ 475 pp = &rx->calls.rb_node; 476 parent = NULL; 477 while (*pp) { 478 parent = *pp; 479 call = rb_entry(parent, struct rxrpc_call, sock_node); 480 481 if (user_call_ID < call->user_call_ID) 482 pp = &(*pp)->rb_left; 483 else if (user_call_ID > call->user_call_ID) 484 pp = &(*pp)->rb_right; 485 else 486 goto id_in_use; 487 } 488 489 /* Dequeue the first call and check it's still valid. We gain 490 * responsibility for the queue's reference. 491 */ 492 call = list_entry(rx->to_be_accepted.next, 493 struct rxrpc_call, accept_link); 494 write_unlock(&rx->call_lock); 495 496 /* We need to gain the mutex from the interrupt handler without 497 * upsetting lockdep, so we have to release it there and take it here. 498 * We are, however, still holding the socket lock, so other accepts 499 * must wait for us and no one can add the user ID behind our backs. 500 */ 501 if (mutex_lock_interruptible(&call->user_mutex) < 0) { 502 release_sock(&rx->sk); 503 kleave(" = -ERESTARTSYS"); 504 return ERR_PTR(-ERESTARTSYS); 505 } 506 507 write_lock(&rx->call_lock); 508 list_del_init(&call->accept_link); 509 sk_acceptq_removed(&rx->sk); 510 rxrpc_see_call(call); 511 512 /* Find the user ID insertion point. */ 513 pp = &rx->calls.rb_node; 514 parent = NULL; 515 while (*pp) { 516 parent = *pp; 517 call = rb_entry(parent, struct rxrpc_call, sock_node); 518 519 if (user_call_ID < call->user_call_ID) 520 pp = &(*pp)->rb_left; 521 else if (user_call_ID > call->user_call_ID) 522 pp = &(*pp)->rb_right; 523 else 524 BUG(); 525 } 526 527 write_lock_bh(&call->state_lock); 528 switch (call->state) { 529 case RXRPC_CALL_SERVER_ACCEPTING: 530 call->state = RXRPC_CALL_SERVER_RECV_REQUEST; 531 break; 532 case RXRPC_CALL_COMPLETE: 533 ret = call->error; 534 goto out_release; 535 default: 536 BUG(); 537 } 538 539 /* formalise the acceptance */ 540 call->notify_rx = notify_rx; 541 call->user_call_ID = user_call_ID; 542 rxrpc_get_call(call, rxrpc_call_got_userid); 543 rb_link_node(&call->sock_node, parent, pp); 544 rb_insert_color(&call->sock_node, &rx->calls); 545 if (test_and_set_bit(RXRPC_CALL_HAS_USERID, &call->flags)) 546 BUG(); 547 548 write_unlock_bh(&call->state_lock); 549 write_unlock(&rx->call_lock); 550 rxrpc_notify_socket(call); 551 rxrpc_service_prealloc(rx, GFP_KERNEL); 552 release_sock(&rx->sk); 553 _leave(" = %p{%d}", call, call->debug_id); 554 return call; 555 556 out_release: 557 _debug("release %p", call); 558 write_unlock_bh(&call->state_lock); 559 write_unlock(&rx->call_lock); 560 rxrpc_release_call(rx, call); 561 rxrpc_put_call(call, rxrpc_call_put); 562 goto out; 563 564 id_in_use: 565 ret = -EBADSLT; 566 write_unlock(&rx->call_lock); 567 out: 568 rxrpc_service_prealloc(rx, GFP_KERNEL); 569 release_sock(&rx->sk); 570 _leave(" = %d", ret); 571 return ERR_PTR(ret); 572 } 573 574 /* 575 * Handle rejection of a call by userspace 576 * - reject the call at the front of the queue 577 */ 578 int rxrpc_reject_call(struct rxrpc_sock *rx) 579 { 580 struct rxrpc_call *call; 581 bool abort = false; 582 int ret; 583 584 _enter(""); 585 586 ASSERT(!irqs_disabled()); 587 588 write_lock(&rx->call_lock); 589 590 if (list_empty(&rx->to_be_accepted)) { 591 write_unlock(&rx->call_lock); 592 return -ENODATA; 593 } 594 595 /* Dequeue the first call and check it's still valid. We gain 596 * responsibility for the queue's reference. 597 */ 598 call = list_entry(rx->to_be_accepted.next, 599 struct rxrpc_call, accept_link); 600 list_del_init(&call->accept_link); 601 sk_acceptq_removed(&rx->sk); 602 rxrpc_see_call(call); 603 604 write_lock_bh(&call->state_lock); 605 switch (call->state) { 606 case RXRPC_CALL_SERVER_ACCEPTING: 607 __rxrpc_abort_call("REJ", call, 1, RX_USER_ABORT, -ECONNABORTED); 608 abort = true; 609 /* fall through */ 610 case RXRPC_CALL_COMPLETE: 611 ret = call->error; 612 goto out_discard; 613 default: 614 BUG(); 615 } 616 617 out_discard: 618 write_unlock_bh(&call->state_lock); 619 write_unlock(&rx->call_lock); 620 if (abort) { 621 rxrpc_send_abort_packet(call); 622 rxrpc_release_call(rx, call); 623 rxrpc_put_call(call, rxrpc_call_put); 624 } 625 rxrpc_service_prealloc(rx, GFP_KERNEL); 626 _leave(" = %d", ret); 627 return ret; 628 } 629 630 /* 631 * rxrpc_kernel_charge_accept - Charge up socket with preallocated calls 632 * @sock: The socket on which to preallocate 633 * @notify_rx: Event notification function for the call 634 * @user_attach_call: Func to attach call to user_call_ID 635 * @user_call_ID: The tag to attach to the preallocated call 636 * @gfp: The allocation conditions. 637 * 638 * Charge up the socket with preallocated calls, each with a user ID. A 639 * function should be provided to effect the attachment from the user's side. 640 * The user is given a ref to hold on the call. 641 * 642 * Note that the call may be come connected before this function returns. 643 */ 644 int rxrpc_kernel_charge_accept(struct socket *sock, 645 rxrpc_notify_rx_t notify_rx, 646 rxrpc_user_attach_call_t user_attach_call, 647 unsigned long user_call_ID, gfp_t gfp) 648 { 649 struct rxrpc_sock *rx = rxrpc_sk(sock->sk); 650 struct rxrpc_backlog *b = rx->backlog; 651 652 if (sock->sk->sk_state == RXRPC_CLOSE) 653 return -ESHUTDOWN; 654 655 return rxrpc_service_prealloc_one(rx, b, notify_rx, 656 user_attach_call, user_call_ID, 657 gfp); 658 } 659 EXPORT_SYMBOL(rxrpc_kernel_charge_accept); 660