1 /* RxRPC recvmsg() implementation 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/net.h> 15 #include <linux/skbuff.h> 16 #include <linux/export.h> 17 #include <net/sock.h> 18 #include <net/af_rxrpc.h> 19 #include "ar-internal.h" 20 21 /* 22 * Post a call for attention by the socket or kernel service. Further 23 * notifications are suppressed by putting recvmsg_link on a dummy queue. 24 */ 25 void rxrpc_notify_socket(struct rxrpc_call *call) 26 { 27 struct rxrpc_sock *rx; 28 struct sock *sk; 29 30 _enter("%d", call->debug_id); 31 32 if (!list_empty(&call->recvmsg_link)) 33 return; 34 35 rcu_read_lock(); 36 37 rx = rcu_dereference(call->socket); 38 sk = &rx->sk; 39 if (rx && sk->sk_state < RXRPC_CLOSE) { 40 if (call->notify_rx) { 41 call->notify_rx(sk, call, call->user_call_ID); 42 } else { 43 write_lock_bh(&rx->recvmsg_lock); 44 if (list_empty(&call->recvmsg_link)) { 45 rxrpc_get_call(call, rxrpc_call_got); 46 list_add_tail(&call->recvmsg_link, &rx->recvmsg_q); 47 } 48 write_unlock_bh(&rx->recvmsg_lock); 49 50 if (!sock_flag(sk, SOCK_DEAD)) { 51 _debug("call %ps", sk->sk_data_ready); 52 sk->sk_data_ready(sk); 53 } 54 } 55 } 56 57 rcu_read_unlock(); 58 _leave(""); 59 } 60 61 /* 62 * Pass a call terminating message to userspace. 63 */ 64 static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg) 65 { 66 u32 tmp = 0; 67 int ret; 68 69 switch (call->completion) { 70 case RXRPC_CALL_SUCCEEDED: 71 ret = 0; 72 if (rxrpc_is_service_call(call)) 73 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp); 74 break; 75 case RXRPC_CALL_REMOTELY_ABORTED: 76 tmp = call->abort_code; 77 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp); 78 break; 79 case RXRPC_CALL_LOCALLY_ABORTED: 80 tmp = call->abort_code; 81 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp); 82 break; 83 case RXRPC_CALL_NETWORK_ERROR: 84 tmp = call->error; 85 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp); 86 break; 87 case RXRPC_CALL_LOCAL_ERROR: 88 tmp = call->error; 89 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp); 90 break; 91 default: 92 pr_err("Invalid terminal call state %u\n", call->state); 93 BUG(); 94 break; 95 } 96 97 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_terminal, call->rx_hard_ack, 98 call->rx_pkt_offset, call->rx_pkt_len, ret); 99 return ret; 100 } 101 102 /* 103 * Pass back notification of a new call. The call is added to the 104 * to-be-accepted list. This means that the next call to be accepted might not 105 * be the last call seen awaiting acceptance, but unless we leave this on the 106 * front of the queue and block all other messages until someone gives us a 107 * user_ID for it, there's not a lot we can do. 108 */ 109 static int rxrpc_recvmsg_new_call(struct rxrpc_sock *rx, 110 struct rxrpc_call *call, 111 struct msghdr *msg, int flags) 112 { 113 int tmp = 0, ret; 114 115 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NEW_CALL, 0, &tmp); 116 117 if (ret == 0 && !(flags & MSG_PEEK)) { 118 _debug("to be accepted"); 119 write_lock_bh(&rx->recvmsg_lock); 120 list_del_init(&call->recvmsg_link); 121 write_unlock_bh(&rx->recvmsg_lock); 122 123 rxrpc_get_call(call, rxrpc_call_got); 124 write_lock(&rx->call_lock); 125 list_add_tail(&call->accept_link, &rx->to_be_accepted); 126 write_unlock(&rx->call_lock); 127 } 128 129 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_to_be_accepted, 1, 0, 0, ret); 130 return ret; 131 } 132 133 /* 134 * End the packet reception phase. 135 */ 136 static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial) 137 { 138 _enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]); 139 140 trace_rxrpc_receive(call, rxrpc_receive_end, 0, call->rx_top); 141 ASSERTCMP(call->rx_hard_ack, ==, call->rx_top); 142 143 if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY) { 144 rxrpc_propose_ACK(call, RXRPC_ACK_IDLE, 0, serial, true, false, 145 rxrpc_propose_ack_terminal_ack); 146 rxrpc_send_ack_packet(call, false); 147 } 148 149 write_lock_bh(&call->state_lock); 150 151 switch (call->state) { 152 case RXRPC_CALL_CLIENT_RECV_REPLY: 153 __rxrpc_call_completed(call); 154 break; 155 156 case RXRPC_CALL_SERVER_RECV_REQUEST: 157 call->tx_phase = true; 158 call->state = RXRPC_CALL_SERVER_ACK_REQUEST; 159 break; 160 default: 161 break; 162 } 163 164 write_unlock_bh(&call->state_lock); 165 } 166 167 /* 168 * Discard a packet we've used up and advance the Rx window by one. 169 */ 170 static void rxrpc_rotate_rx_window(struct rxrpc_call *call) 171 { 172 struct rxrpc_skb_priv *sp; 173 struct sk_buff *skb; 174 rxrpc_serial_t serial; 175 rxrpc_seq_t hard_ack, top; 176 u8 flags; 177 int ix; 178 179 _enter("%d", call->debug_id); 180 181 hard_ack = call->rx_hard_ack; 182 top = smp_load_acquire(&call->rx_top); 183 ASSERT(before(hard_ack, top)); 184 185 hard_ack++; 186 ix = hard_ack & RXRPC_RXTX_BUFF_MASK; 187 skb = call->rxtx_buffer[ix]; 188 rxrpc_see_skb(skb, rxrpc_skb_rx_rotated); 189 sp = rxrpc_skb(skb); 190 flags = sp->hdr.flags; 191 serial = sp->hdr.serial; 192 if (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO) 193 serial += (call->rxtx_annotations[ix] & RXRPC_RX_ANNO_JUMBO) - 1; 194 195 call->rxtx_buffer[ix] = NULL; 196 call->rxtx_annotations[ix] = 0; 197 /* Barrier against rxrpc_input_data(). */ 198 smp_store_release(&call->rx_hard_ack, hard_ack); 199 200 rxrpc_free_skb(skb, rxrpc_skb_rx_freed); 201 202 _debug("%u,%u,%02x", hard_ack, top, flags); 203 trace_rxrpc_receive(call, rxrpc_receive_rotate, serial, hard_ack); 204 if (flags & RXRPC_LAST_PACKET) { 205 rxrpc_end_rx_phase(call, serial); 206 } else { 207 /* Check to see if there's an ACK that needs sending. */ 208 if (after_eq(hard_ack, call->ackr_consumed + 2) || 209 after_eq(top, call->ackr_seen + 2) || 210 (hard_ack == top && after(hard_ack, call->ackr_consumed))) 211 rxrpc_propose_ACK(call, RXRPC_ACK_DELAY, 0, serial, 212 true, false, 213 rxrpc_propose_ack_rotate_rx); 214 if (call->ackr_reason) 215 rxrpc_send_ack_packet(call, false); 216 } 217 } 218 219 /* 220 * Decrypt and verify a (sub)packet. The packet's length may be changed due to 221 * padding, but if this is the case, the packet length will be resident in the 222 * socket buffer. Note that we can't modify the master skb info as the skb may 223 * be the home to multiple subpackets. 224 */ 225 static int rxrpc_verify_packet(struct rxrpc_call *call, struct sk_buff *skb, 226 u8 annotation, 227 unsigned int offset, unsigned int len) 228 { 229 struct rxrpc_skb_priv *sp = rxrpc_skb(skb); 230 rxrpc_seq_t seq = sp->hdr.seq; 231 u16 cksum = sp->hdr.cksum; 232 233 _enter(""); 234 235 /* For all but the head jumbo subpacket, the security checksum is in a 236 * jumbo header immediately prior to the data. 237 */ 238 if ((annotation & RXRPC_RX_ANNO_JUMBO) > 1) { 239 __be16 tmp; 240 if (skb_copy_bits(skb, offset - 2, &tmp, 2) < 0) 241 BUG(); 242 cksum = ntohs(tmp); 243 seq += (annotation & RXRPC_RX_ANNO_JUMBO) - 1; 244 } 245 246 return call->conn->security->verify_packet(call, skb, offset, len, 247 seq, cksum); 248 } 249 250 /* 251 * Locate the data within a packet. This is complicated by: 252 * 253 * (1) An skb may contain a jumbo packet - so we have to find the appropriate 254 * subpacket. 255 * 256 * (2) The (sub)packets may be encrypted and, if so, the encrypted portion 257 * contains an extra header which includes the true length of the data, 258 * excluding any encrypted padding. 259 */ 260 static int rxrpc_locate_data(struct rxrpc_call *call, struct sk_buff *skb, 261 u8 *_annotation, 262 unsigned int *_offset, unsigned int *_len) 263 { 264 unsigned int offset = sizeof(struct rxrpc_wire_header); 265 unsigned int len = *_len; 266 int ret; 267 u8 annotation = *_annotation; 268 269 /* Locate the subpacket */ 270 len = skb->len - offset; 271 if ((annotation & RXRPC_RX_ANNO_JUMBO) > 0) { 272 offset += (((annotation & RXRPC_RX_ANNO_JUMBO) - 1) * 273 RXRPC_JUMBO_SUBPKTLEN); 274 len = (annotation & RXRPC_RX_ANNO_JLAST) ? 275 skb->len - offset : RXRPC_JUMBO_SUBPKTLEN; 276 } 277 278 if (!(annotation & RXRPC_RX_ANNO_VERIFIED)) { 279 ret = rxrpc_verify_packet(call, skb, annotation, offset, len); 280 if (ret < 0) 281 return ret; 282 *_annotation |= RXRPC_RX_ANNO_VERIFIED; 283 } 284 285 *_offset = offset; 286 *_len = len; 287 call->conn->security->locate_data(call, skb, _offset, _len); 288 return 0; 289 } 290 291 /* 292 * Deliver messages to a call. This keeps processing packets until the buffer 293 * is filled and we find either more DATA (returns 0) or the end of the DATA 294 * (returns 1). If more packets are required, it returns -EAGAIN. 295 */ 296 static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call, 297 struct msghdr *msg, struct iov_iter *iter, 298 size_t len, int flags, size_t *_offset) 299 { 300 struct rxrpc_skb_priv *sp; 301 struct sk_buff *skb; 302 rxrpc_seq_t hard_ack, top, seq; 303 size_t remain; 304 bool last; 305 unsigned int rx_pkt_offset, rx_pkt_len; 306 int ix, copy, ret = -EAGAIN, ret2; 307 308 rx_pkt_offset = call->rx_pkt_offset; 309 rx_pkt_len = call->rx_pkt_len; 310 311 if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) { 312 seq = call->rx_hard_ack; 313 ret = 1; 314 goto done; 315 } 316 317 /* Barriers against rxrpc_input_data(). */ 318 hard_ack = call->rx_hard_ack; 319 top = smp_load_acquire(&call->rx_top); 320 for (seq = hard_ack + 1; before_eq(seq, top); seq++) { 321 ix = seq & RXRPC_RXTX_BUFF_MASK; 322 skb = call->rxtx_buffer[ix]; 323 if (!skb) { 324 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_hole, seq, 325 rx_pkt_offset, rx_pkt_len, 0); 326 break; 327 } 328 smp_rmb(); 329 rxrpc_see_skb(skb, rxrpc_skb_rx_seen); 330 sp = rxrpc_skb(skb); 331 332 if (!(flags & MSG_PEEK)) 333 trace_rxrpc_receive(call, rxrpc_receive_front, 334 sp->hdr.serial, seq); 335 336 if (msg) 337 sock_recv_timestamp(msg, sock->sk, skb); 338 339 if (rx_pkt_offset == 0) { 340 ret2 = rxrpc_locate_data(call, skb, 341 &call->rxtx_annotations[ix], 342 &rx_pkt_offset, &rx_pkt_len); 343 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_next, seq, 344 rx_pkt_offset, rx_pkt_len, ret2); 345 if (ret2 < 0) { 346 ret = ret2; 347 goto out; 348 } 349 } else { 350 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_cont, seq, 351 rx_pkt_offset, rx_pkt_len, 0); 352 } 353 354 /* We have to handle short, empty and used-up DATA packets. */ 355 remain = len - *_offset; 356 copy = rx_pkt_len; 357 if (copy > remain) 358 copy = remain; 359 if (copy > 0) { 360 ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter, 361 copy); 362 if (ret2 < 0) { 363 ret = ret2; 364 goto out; 365 } 366 367 /* handle piecemeal consumption of data packets */ 368 rx_pkt_offset += copy; 369 rx_pkt_len -= copy; 370 *_offset += copy; 371 } 372 373 if (rx_pkt_len > 0) { 374 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_full, seq, 375 rx_pkt_offset, rx_pkt_len, 0); 376 ASSERTCMP(*_offset, ==, len); 377 ret = 0; 378 break; 379 } 380 381 /* The whole packet has been transferred. */ 382 last = sp->hdr.flags & RXRPC_LAST_PACKET; 383 if (!(flags & MSG_PEEK)) 384 rxrpc_rotate_rx_window(call); 385 rx_pkt_offset = 0; 386 rx_pkt_len = 0; 387 388 if (last) { 389 ASSERTCMP(seq, ==, READ_ONCE(call->rx_top)); 390 ret = 1; 391 goto out; 392 } 393 } 394 395 out: 396 if (!(flags & MSG_PEEK)) { 397 call->rx_pkt_offset = rx_pkt_offset; 398 call->rx_pkt_len = rx_pkt_len; 399 } 400 done: 401 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_data_return, seq, 402 rx_pkt_offset, rx_pkt_len, ret); 403 return ret; 404 } 405 406 /* 407 * Receive a message from an RxRPC socket 408 * - we need to be careful about two or more threads calling recvmsg 409 * simultaneously 410 */ 411 int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len, 412 int flags) 413 { 414 struct rxrpc_call *call; 415 struct rxrpc_sock *rx = rxrpc_sk(sock->sk); 416 struct list_head *l; 417 size_t copied = 0; 418 long timeo; 419 int ret; 420 421 DEFINE_WAIT(wait); 422 423 trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0, 0, 0, 0); 424 425 if (flags & (MSG_OOB | MSG_TRUNC)) 426 return -EOPNOTSUPP; 427 428 timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT); 429 430 try_again: 431 lock_sock(&rx->sk); 432 433 /* Return immediately if a client socket has no outstanding calls */ 434 if (RB_EMPTY_ROOT(&rx->calls) && 435 list_empty(&rx->recvmsg_q) && 436 rx->sk.sk_state != RXRPC_SERVER_LISTENING) { 437 release_sock(&rx->sk); 438 return -ENODATA; 439 } 440 441 if (list_empty(&rx->recvmsg_q)) { 442 ret = -EWOULDBLOCK; 443 if (timeo == 0) { 444 call = NULL; 445 goto error_no_call; 446 } 447 448 release_sock(&rx->sk); 449 450 /* Wait for something to happen */ 451 prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait, 452 TASK_INTERRUPTIBLE); 453 ret = sock_error(&rx->sk); 454 if (ret) 455 goto wait_error; 456 457 if (list_empty(&rx->recvmsg_q)) { 458 if (signal_pending(current)) 459 goto wait_interrupted; 460 trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait, 461 0, 0, 0, 0); 462 timeo = schedule_timeout(timeo); 463 } 464 finish_wait(sk_sleep(&rx->sk), &wait); 465 goto try_again; 466 } 467 468 /* Find the next call and dequeue it if we're not just peeking. If we 469 * do dequeue it, that comes with a ref that we will need to release. 470 */ 471 write_lock_bh(&rx->recvmsg_lock); 472 l = rx->recvmsg_q.next; 473 call = list_entry(l, struct rxrpc_call, recvmsg_link); 474 if (!(flags & MSG_PEEK)) 475 list_del_init(&call->recvmsg_link); 476 else 477 rxrpc_get_call(call, rxrpc_call_got); 478 write_unlock_bh(&rx->recvmsg_lock); 479 480 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0, 0, 0, 0); 481 482 if (test_bit(RXRPC_CALL_RELEASED, &call->flags)) 483 BUG(); 484 485 if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) { 486 if (flags & MSG_CMSG_COMPAT) { 487 unsigned int id32 = call->user_call_ID; 488 489 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, 490 sizeof(unsigned int), &id32); 491 } else { 492 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID, 493 sizeof(unsigned long), 494 &call->user_call_ID); 495 } 496 if (ret < 0) 497 goto error; 498 } 499 500 if (msg->msg_name) { 501 size_t len = sizeof(call->conn->params.peer->srx); 502 memcpy(msg->msg_name, &call->conn->params.peer->srx, len); 503 msg->msg_namelen = len; 504 } 505 506 switch (call->state) { 507 case RXRPC_CALL_SERVER_ACCEPTING: 508 ret = rxrpc_recvmsg_new_call(rx, call, msg, flags); 509 break; 510 case RXRPC_CALL_CLIENT_RECV_REPLY: 511 case RXRPC_CALL_SERVER_RECV_REQUEST: 512 case RXRPC_CALL_SERVER_ACK_REQUEST: 513 ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len, 514 flags, &copied); 515 if (ret == -EAGAIN) 516 ret = 0; 517 518 if (after(call->rx_top, call->rx_hard_ack) && 519 call->rxtx_buffer[(call->rx_hard_ack + 1) & RXRPC_RXTX_BUFF_MASK]) 520 rxrpc_notify_socket(call); 521 break; 522 default: 523 ret = 0; 524 break; 525 } 526 527 if (ret < 0) 528 goto error; 529 530 if (call->state == RXRPC_CALL_COMPLETE) { 531 ret = rxrpc_recvmsg_term(call, msg); 532 if (ret < 0) 533 goto error; 534 if (!(flags & MSG_PEEK)) 535 rxrpc_release_call(rx, call); 536 msg->msg_flags |= MSG_EOR; 537 ret = 1; 538 } 539 540 if (ret == 0) 541 msg->msg_flags |= MSG_MORE; 542 else 543 msg->msg_flags &= ~MSG_MORE; 544 ret = copied; 545 546 error: 547 rxrpc_put_call(call, rxrpc_call_put); 548 error_no_call: 549 release_sock(&rx->sk); 550 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, 0, 0, 0, ret); 551 return ret; 552 553 wait_interrupted: 554 ret = sock_intr_errno(timeo); 555 wait_error: 556 finish_wait(sk_sleep(&rx->sk), &wait); 557 call = NULL; 558 goto error_no_call; 559 } 560 561 /** 562 * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info 563 * @sock: The socket that the call exists on 564 * @call: The call to send data through 565 * @buf: The buffer to receive into 566 * @size: The size of the buffer, including data already read 567 * @_offset: The running offset into the buffer. 568 * @want_more: True if more data is expected to be read 569 * @_abort: Where the abort code is stored if -ECONNABORTED is returned 570 * 571 * Allow a kernel service to receive data and pick up information about the 572 * state of a call. Returns 0 if got what was asked for and there's more 573 * available, 1 if we got what was asked for and we're at the end of the data 574 * and -EAGAIN if we need more data. 575 * 576 * Note that we may return -EAGAIN to drain empty packets at the end of the 577 * data, even if we've already copied over the requested data. 578 * 579 * This function adds the amount it transfers to *_offset, so this should be 580 * precleared as appropriate. Note that the amount remaining in the buffer is 581 * taken to be size - *_offset. 582 * 583 * *_abort should also be initialised to 0. 584 */ 585 int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call, 586 void *buf, size_t size, size_t *_offset, 587 bool want_more, u32 *_abort) 588 { 589 struct iov_iter iter; 590 struct kvec iov; 591 int ret; 592 593 _enter("{%d,%s},%zu/%zu,%d", 594 call->debug_id, rxrpc_call_states[call->state], 595 *_offset, size, want_more); 596 597 ASSERTCMP(*_offset, <=, size); 598 ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_ACCEPTING); 599 600 iov.iov_base = buf + *_offset; 601 iov.iov_len = size - *_offset; 602 iov_iter_kvec(&iter, ITER_KVEC | READ, &iov, 1, size - *_offset); 603 604 lock_sock(sock->sk); 605 606 switch (call->state) { 607 case RXRPC_CALL_CLIENT_RECV_REPLY: 608 case RXRPC_CALL_SERVER_RECV_REQUEST: 609 case RXRPC_CALL_SERVER_ACK_REQUEST: 610 ret = rxrpc_recvmsg_data(sock, call, NULL, &iter, size, 0, 611 _offset); 612 if (ret < 0) 613 goto out; 614 615 /* We can only reach here with a partially full buffer if we 616 * have reached the end of the data. We must otherwise have a 617 * full buffer or have been given -EAGAIN. 618 */ 619 if (ret == 1) { 620 if (*_offset < size) 621 goto short_data; 622 if (!want_more) 623 goto read_phase_complete; 624 ret = 0; 625 goto out; 626 } 627 628 if (!want_more) 629 goto excess_data; 630 goto out; 631 632 case RXRPC_CALL_COMPLETE: 633 goto call_complete; 634 635 default: 636 ret = -EINPROGRESS; 637 goto out; 638 } 639 640 read_phase_complete: 641 ret = 1; 642 out: 643 release_sock(sock->sk); 644 _leave(" = %d [%zu,%d]", ret, *_offset, *_abort); 645 return ret; 646 647 short_data: 648 ret = -EBADMSG; 649 goto out; 650 excess_data: 651 ret = -EMSGSIZE; 652 goto out; 653 call_complete: 654 *_abort = call->abort_code; 655 ret = -call->error; 656 if (call->completion == RXRPC_CALL_SUCCEEDED) { 657 ret = 1; 658 if (size > 0) 659 ret = -ECONNRESET; 660 } 661 goto out; 662 } 663 EXPORT_SYMBOL(rxrpc_kernel_recv_data); 664