net/rxrpc/recvmsg.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* RxRPC recvmsg() implementation
   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/net.h>
  11 #include <linux/skbuff.h>
  12 #include <linux/export.h>
  13 #include <linux/sched/signal.h>
  14
  15 #include <net/sock.h>
  16 #include <net/af_rxrpc.h>
  17 #include "ar-internal.h"
  18
  19 /*
  20  * Post a call for attention by the socket or kernel service.  Further
  21  * notifications are suppressed by putting recvmsg_link on a dummy queue.
  22  */
  23 void rxrpc_notify_socket(struct rxrpc_call *call)
  24 {
  25         struct rxrpc_sock *rx;
  26         struct sock *sk;
  27
  28         _enter("%d", call->debug_id);
  29
  30         if (!list_empty(&call->recvmsg_link))
  31                 return;
  32
  33         rcu_read_lock();
  34
  35         rx = rcu_dereference(call->socket);
  36         sk = &rx->sk;
  37         if (rx && sk->sk_state < RXRPC_CLOSE) {
  38                 if (call->notify_rx) {
  39                         spin_lock_bh(&call->notify_lock);
  40                         call->notify_rx(sk, call, call->user_call_ID);
  41                         spin_unlock_bh(&call->notify_lock);
  42                 } else {
  43                         write_lock_bh(&rx->recvmsg_lock);
  44                         if (list_empty(&call->recvmsg_link)) {
  45                                 rxrpc_get_call(call, rxrpc_call_get_notify_socket);
  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  * Transition a call to the complete state.
  63  */
  64 bool __rxrpc_set_call_completion(struct rxrpc_call *call,
  65                                  enum rxrpc_call_completion compl,
  66                                  u32 abort_code,
  67                                  int error)
  68 {
  69         if (call->state < RXRPC_CALL_COMPLETE) {
  70                 call->abort_code = abort_code;
  71                 call->error = error;
  72                 call->completion = compl;
  73                 call->state = RXRPC_CALL_COMPLETE;
  74                 trace_rxrpc_call_complete(call);
  75                 wake_up(&call->waitq);
  76                 rxrpc_notify_socket(call);
  77                 return true;
  78         }
  79         return false;
  80 }
  81
  82 bool rxrpc_set_call_completion(struct rxrpc_call *call,
  83                                enum rxrpc_call_completion compl,
  84                                u32 abort_code,
  85                                int error)
  86 {
  87         bool ret = false;
  88
  89         if (call->state < RXRPC_CALL_COMPLETE) {
  90                 write_lock_bh(&call->state_lock);
  91                 ret = __rxrpc_set_call_completion(call, compl, abort_code, error);
  92                 write_unlock_bh(&call->state_lock);
  93         }
  94         return ret;
  95 }
  96
  97 /*
  98  * Record that a call successfully completed.
  99  */
 100 bool __rxrpc_call_completed(struct rxrpc_call *call)
 101 {
 102         return __rxrpc_set_call_completion(call, RXRPC_CALL_SUCCEEDED, 0, 0);
 103 }
 104
 105 bool rxrpc_call_completed(struct rxrpc_call *call)
 106 {
 107         bool ret = false;
 108
 109         if (call->state < RXRPC_CALL_COMPLETE) {
 110                 write_lock_bh(&call->state_lock);
 111                 ret = __rxrpc_call_completed(call);
 112                 write_unlock_bh(&call->state_lock);
 113         }
 114         return ret;
 115 }
 116
 117 /*
 118  * Record that a call is locally aborted.
 119  */
 120 bool __rxrpc_abort_call(const char *why, struct rxrpc_call *call,
 121                         rxrpc_seq_t seq, u32 abort_code, int error)
 122 {
 123         trace_rxrpc_abort(call->debug_id, why, call->cid, call->call_id, seq,
 124                           abort_code, error);
 125         return __rxrpc_set_call_completion(call, RXRPC_CALL_LOCALLY_ABORTED,
 126                                            abort_code, error);
 127 }
 128
 129 bool rxrpc_abort_call(const char *why, struct rxrpc_call *call,
 130                       rxrpc_seq_t seq, u32 abort_code, int error)
 131 {
 132         bool ret;
 133
 134         write_lock_bh(&call->state_lock);
 135         ret = __rxrpc_abort_call(why, call, seq, abort_code, error);
 136         write_unlock_bh(&call->state_lock);
 137         return ret;
 138 }
 139
 140 /*
 141  * Pass a call terminating message to userspace.
 142  */
 143 static int rxrpc_recvmsg_term(struct rxrpc_call *call, struct msghdr *msg)
 144 {
 145         u32 tmp = 0;
 146         int ret;
 147
 148         switch (call->completion) {
 149         case RXRPC_CALL_SUCCEEDED:
 150                 ret = 0;
 151                 if (rxrpc_is_service_call(call))
 152                         ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ACK, 0, &tmp);
 153                 break;
 154         case RXRPC_CALL_REMOTELY_ABORTED:
 155                 tmp = call->abort_code;
 156                 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
 157                 break;
 158         case RXRPC_CALL_LOCALLY_ABORTED:
 159                 tmp = call->abort_code;
 160                 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_ABORT, 4, &tmp);
 161                 break;
 162         case RXRPC_CALL_NETWORK_ERROR:
 163                 tmp = -call->error;
 164                 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_NET_ERROR, 4, &tmp);
 165                 break;
 166         case RXRPC_CALL_LOCAL_ERROR:
 167                 tmp = -call->error;
 168                 ret = put_cmsg(msg, SOL_RXRPC, RXRPC_LOCAL_ERROR, 4, &tmp);
 169                 break;
 170         default:
 171                 pr_err("Invalid terminal call state %u\n", call->state);
 172                 BUG();
 173                 break;
 174         }
 175
 176         trace_rxrpc_recvdata(call, rxrpc_recvmsg_terminal,
 177                              lower_32_bits(atomic64_read(&call->ackr_window)) - 1,
 178                              call->rx_pkt_offset, call->rx_pkt_len, ret);
 179         return ret;
 180 }
 181
 182 /*
 183  * End the packet reception phase.
 184  */
 185 static void rxrpc_end_rx_phase(struct rxrpc_call *call, rxrpc_serial_t serial)
 186 {
 187         rxrpc_seq_t whigh = READ_ONCE(call->rx_highest_seq);
 188
 189         _enter("%d,%s", call->debug_id, rxrpc_call_states[call->state]);
 190
 191         trace_rxrpc_receive(call, rxrpc_receive_end, 0, whigh);
 192
 193         if (call->state == RXRPC_CALL_CLIENT_RECV_REPLY)
 194                 rxrpc_propose_delay_ACK(call, serial, rxrpc_propose_ack_terminal_ack);
 195
 196         write_lock_bh(&call->state_lock);
 197
 198         switch (call->state) {
 199         case RXRPC_CALL_CLIENT_RECV_REPLY:
 200                 __rxrpc_call_completed(call);
 201                 write_unlock_bh(&call->state_lock);
 202                 break;
 203
 204         case RXRPC_CALL_SERVER_RECV_REQUEST:
 205                 call->state = RXRPC_CALL_SERVER_ACK_REQUEST;
 206                 call->expect_req_by = jiffies + MAX_JIFFY_OFFSET;
 207                 write_unlock_bh(&call->state_lock);
 208                 rxrpc_propose_delay_ACK(call, serial,
 209                                         rxrpc_propose_ack_processing_op);
 210                 break;
 211         default:
 212                 write_unlock_bh(&call->state_lock);
 213                 break;
 214         }
 215 }
 216
 217 /*
 218  * Discard a packet we've used up and advance the Rx window by one.
 219  */
 220 static void rxrpc_rotate_rx_window(struct rxrpc_call *call)
 221 {
 222         struct rxrpc_skb_priv *sp;
 223         struct sk_buff *skb;
 224         rxrpc_serial_t serial;
 225         rxrpc_seq_t old_consumed = call->rx_consumed, tseq;
 226         bool last;
 227         int acked;
 228
 229         _enter("%d", call->debug_id);
 230
 231         skb = skb_dequeue(&call->recvmsg_queue);
 232         rxrpc_see_skb(skb, rxrpc_skb_see_rotate);
 233
 234         sp = rxrpc_skb(skb);
 235         tseq   = sp->hdr.seq;
 236         serial = sp->hdr.serial;
 237         last   = sp->hdr.flags & RXRPC_LAST_PACKET;
 238
 239         /* Barrier against rxrpc_input_data(). */
 240         if (after(tseq, call->rx_consumed))
 241                 smp_store_release(&call->rx_consumed, tseq);
 242
 243         rxrpc_free_skb(skb, rxrpc_skb_put_rotate);
 244
 245         trace_rxrpc_receive(call, last ? rxrpc_receive_rotate_last : rxrpc_receive_rotate,
 246                             serial, call->rx_consumed);
 247         if (last) {
 248                 rxrpc_end_rx_phase(call, serial);
 249                 return;
 250         }
 251
 252         /* Check to see if there's an ACK that needs sending. */
 253         acked = atomic_add_return(call->rx_consumed - old_consumed,
 254                                   &call->ackr_nr_consumed);
 255         if (acked > 2 &&
 256             !test_and_set_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags))
 257                 rxrpc_poke_call(call, rxrpc_call_poke_idle);
 258 }
 259
 260 /*
 261  * Decrypt and verify a DATA packet.
 262  */
 263 static int rxrpc_verify_data(struct rxrpc_call *call, struct sk_buff *skb)
 264 {
 265         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 266
 267         if (sp->flags & RXRPC_RX_VERIFIED)
 268                 return 0;
 269         return call->security->verify_packet(call, skb);
 270 }
 271
 272 /*
 273  * Deliver messages to a call.  This keeps processing packets until the buffer
 274  * is filled and we find either more DATA (returns 0) or the end of the DATA
 275  * (returns 1).  If more packets are required, it returns -EAGAIN.
 276  */
 277 static int rxrpc_recvmsg_data(struct socket *sock, struct rxrpc_call *call,
 278                               struct msghdr *msg, struct iov_iter *iter,
 279                               size_t len, int flags, size_t *_offset)
 280 {
 281         struct rxrpc_skb_priv *sp;
 282         struct sk_buff *skb;
 283         rxrpc_seq_t seq = 0;
 284         size_t remain;
 285         unsigned int rx_pkt_offset, rx_pkt_len;
 286         int copy, ret = -EAGAIN, ret2;
 287
 288         rx_pkt_offset = call->rx_pkt_offset;
 289         rx_pkt_len = call->rx_pkt_len;
 290
 291         if (call->state >= RXRPC_CALL_SERVER_ACK_REQUEST) {
 292                 seq = lower_32_bits(atomic64_read(&call->ackr_window)) - 1;
 293                 ret = 1;
 294                 goto done;
 295         }
 296
 297         /* No one else can be removing stuff from the queue, so we shouldn't
 298          * need the Rx lock to walk it.
 299          */
 300         skb = skb_peek(&call->recvmsg_queue);
 301         while (skb) {
 302                 rxrpc_see_skb(skb, rxrpc_skb_see_recvmsg);
 303                 sp = rxrpc_skb(skb);
 304                 seq = sp->hdr.seq;
 305
 306                 if (!(flags & MSG_PEEK))
 307                         trace_rxrpc_receive(call, rxrpc_receive_front,
 308                                             sp->hdr.serial, seq);
 309
 310                 if (msg)
 311                         sock_recv_timestamp(msg, sock->sk, skb);
 312
 313                 if (rx_pkt_offset == 0) {
 314                         ret2 = rxrpc_verify_data(call, skb);
 315                         rx_pkt_offset = sp->offset;
 316                         rx_pkt_len = sp->len;
 317                         trace_rxrpc_recvdata(call, rxrpc_recvmsg_next, seq,
 318                                              rx_pkt_offset, rx_pkt_len, ret2);
 319                         if (ret2 < 0) {
 320                                 ret = ret2;
 321                                 goto out;
 322                         }
 323                         rxrpc_transmit_ack_packets(call->peer->local);
 324                 } else {
 325                         trace_rxrpc_recvdata(call, rxrpc_recvmsg_cont, seq,
 326                                              rx_pkt_offset, rx_pkt_len, 0);
 327                 }
 328
 329                 /* We have to handle short, empty and used-up DATA packets. */
 330                 remain = len - *_offset;
 331                 copy = rx_pkt_len;
 332                 if (copy > remain)
 333                         copy = remain;
 334                 if (copy > 0) {
 335                         ret2 = skb_copy_datagram_iter(skb, rx_pkt_offset, iter,
 336                                                       copy);
 337                         if (ret2 < 0) {
 338                                 ret = ret2;
 339                                 goto out;
 340                         }
 341
 342                         /* handle piecemeal consumption of data packets */
 343                         rx_pkt_offset += copy;
 344                         rx_pkt_len -= copy;
 345                         *_offset += copy;
 346                 }
 347
 348                 if (rx_pkt_len > 0) {
 349                         trace_rxrpc_recvdata(call, rxrpc_recvmsg_full, seq,
 350                                              rx_pkt_offset, rx_pkt_len, 0);
 351                         ASSERTCMP(*_offset, ==, len);
 352                         ret = 0;
 353                         break;
 354                 }
 355
 356                 /* The whole packet has been transferred. */
 357                 if (sp->hdr.flags & RXRPC_LAST_PACKET)
 358                         ret = 1;
 359                 rx_pkt_offset = 0;
 360                 rx_pkt_len = 0;
 361
 362                 skb = skb_peek_next(skb, &call->recvmsg_queue);
 363
 364                 if (!(flags & MSG_PEEK))
 365                         rxrpc_rotate_rx_window(call);
 366         }
 367
 368 out:
 369         if (!(flags & MSG_PEEK)) {
 370                 call->rx_pkt_offset = rx_pkt_offset;
 371                 call->rx_pkt_len = rx_pkt_len;
 372         }
 373 done:
 374         trace_rxrpc_recvdata(call, rxrpc_recvmsg_data_return, seq,
 375                              rx_pkt_offset, rx_pkt_len, ret);
 376         if (ret == -EAGAIN)
 377                 set_bit(RXRPC_CALL_RX_IS_IDLE, &call->flags);
 378         return ret;
 379 }
 380
 381 /*
 382  * Receive a message from an RxRPC socket
 383  * - we need to be careful about two or more threads calling recvmsg
 384  *   simultaneously
 385  */
 386 int rxrpc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 387                   int flags)
 388 {
 389         struct rxrpc_call *call;
 390         struct rxrpc_sock *rx = rxrpc_sk(sock->sk);
 391         struct list_head *l;
 392         size_t copied = 0;
 393         long timeo;
 394         int ret;
 395
 396         DEFINE_WAIT(wait);
 397
 398         trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_enter, 0);
 399
 400         if (flags & (MSG_OOB | MSG_TRUNC))
 401                 return -EOPNOTSUPP;
 402
 403         timeo = sock_rcvtimeo(&rx->sk, flags & MSG_DONTWAIT);
 404
 405 try_again:
 406         lock_sock(&rx->sk);
 407
 408         /* Return immediately if a client socket has no outstanding calls */
 409         if (RB_EMPTY_ROOT(&rx->calls) &&
 410             list_empty(&rx->recvmsg_q) &&
 411             rx->sk.sk_state != RXRPC_SERVER_LISTENING) {
 412                 release_sock(&rx->sk);
 413                 return -EAGAIN;
 414         }
 415
 416         if (list_empty(&rx->recvmsg_q)) {
 417                 ret = -EWOULDBLOCK;
 418                 if (timeo == 0) {
 419                         call = NULL;
 420                         goto error_no_call;
 421                 }
 422
 423                 release_sock(&rx->sk);
 424
 425                 /* Wait for something to happen */
 426                 prepare_to_wait_exclusive(sk_sleep(&rx->sk), &wait,
 427                                           TASK_INTERRUPTIBLE);
 428                 ret = sock_error(&rx->sk);
 429                 if (ret)
 430                         goto wait_error;
 431
 432                 if (list_empty(&rx->recvmsg_q)) {
 433                         if (signal_pending(current))
 434                                 goto wait_interrupted;
 435                         trace_rxrpc_recvmsg(NULL, rxrpc_recvmsg_wait, 0);
 436                         timeo = schedule_timeout(timeo);
 437                 }
 438                 finish_wait(sk_sleep(&rx->sk), &wait);
 439                 goto try_again;
 440         }
 441
 442         /* Find the next call and dequeue it if we're not just peeking.  If we
 443          * do dequeue it, that comes with a ref that we will need to release.
 444          */
 445         write_lock_bh(&rx->recvmsg_lock);
 446         l = rx->recvmsg_q.next;
 447         call = list_entry(l, struct rxrpc_call, recvmsg_link);
 448         if (!(flags & MSG_PEEK))
 449                 list_del_init(&call->recvmsg_link);
 450         else
 451                 rxrpc_get_call(call, rxrpc_call_get_recvmsg);
 452         write_unlock_bh(&rx->recvmsg_lock);
 453
 454         trace_rxrpc_recvmsg(call, rxrpc_recvmsg_dequeue, 0);
 455
 456         /* We're going to drop the socket lock, so we need to lock the call
 457          * against interference by sendmsg.
 458          */
 459         if (!mutex_trylock(&call->user_mutex)) {
 460                 ret = -EWOULDBLOCK;
 461                 if (flags & MSG_DONTWAIT)
 462                         goto error_requeue_call;
 463                 ret = -ERESTARTSYS;
 464                 if (mutex_lock_interruptible(&call->user_mutex) < 0)
 465                         goto error_requeue_call;
 466         }
 467
 468         release_sock(&rx->sk);
 469
 470         if (test_bit(RXRPC_CALL_RELEASED, &call->flags))
 471                 BUG();
 472
 473         if (test_bit(RXRPC_CALL_HAS_USERID, &call->flags)) {
 474                 if (flags & MSG_CMSG_COMPAT) {
 475                         unsigned int id32 = call->user_call_ID;
 476
 477                         ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
 478                                        sizeof(unsigned int), &id32);
 479                 } else {
 480                         unsigned long idl = call->user_call_ID;
 481
 482                         ret = put_cmsg(msg, SOL_RXRPC, RXRPC_USER_CALL_ID,
 483                                        sizeof(unsigned long), &idl);
 484                 }
 485                 if (ret < 0)
 486                         goto error_unlock_call;
 487         }
 488
 489         if (msg->msg_name && call->peer) {
 490                 size_t len = sizeof(call->dest_srx);
 491
 492                 memcpy(msg->msg_name, &call->dest_srx, len);
 493                 msg->msg_namelen = len;
 494         }
 495
 496         switch (READ_ONCE(call->state)) {
 497         case RXRPC_CALL_CLIENT_RECV_REPLY:
 498         case RXRPC_CALL_SERVER_RECV_REQUEST:
 499         case RXRPC_CALL_SERVER_ACK_REQUEST:
 500                 ret = rxrpc_recvmsg_data(sock, call, msg, &msg->msg_iter, len,
 501                                          flags, &copied);
 502                 if (ret == -EAGAIN)
 503                         ret = 0;
 504
 505                 rxrpc_transmit_ack_packets(call->peer->local);
 506                 if (!skb_queue_empty(&call->recvmsg_queue))
 507                         rxrpc_notify_socket(call);
 508                 break;
 509         default:
 510                 ret = 0;
 511                 break;
 512         }
 513
 514         if (ret < 0)
 515                 goto error_unlock_call;
 516
 517         if (call->state == RXRPC_CALL_COMPLETE) {
 518                 ret = rxrpc_recvmsg_term(call, msg);
 519                 if (ret < 0)
 520                         goto error_unlock_call;
 521                 if (!(flags & MSG_PEEK))
 522                         rxrpc_release_call(rx, call);
 523                 msg->msg_flags |= MSG_EOR;
 524                 ret = 1;
 525         }
 526
 527         if (ret == 0)
 528                 msg->msg_flags |= MSG_MORE;
 529         else
 530                 msg->msg_flags &= ~MSG_MORE;
 531         ret = copied;
 532
 533 error_unlock_call:
 534         mutex_unlock(&call->user_mutex);
 535         rxrpc_put_call(call, rxrpc_call_put_recvmsg);
 536         trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, ret);
 537         return ret;
 538
 539 error_requeue_call:
 540         if (!(flags & MSG_PEEK)) {
 541                 write_lock_bh(&rx->recvmsg_lock);
 542                 list_add(&call->recvmsg_link, &rx->recvmsg_q);
 543                 write_unlock_bh(&rx->recvmsg_lock);
 544                 trace_rxrpc_recvmsg(call, rxrpc_recvmsg_requeue, 0);
 545         } else {
 546                 rxrpc_put_call(call, rxrpc_call_put_recvmsg);
 547         }
 548 error_no_call:
 549         release_sock(&rx->sk);
 550 error_trace:
 551         trace_rxrpc_recvmsg(call, rxrpc_recvmsg_return, ret);
 552         return ret;
 553
 554 wait_interrupted:
 555         ret = sock_intr_errno(timeo);
 556 wait_error:
 557         finish_wait(sk_sleep(&rx->sk), &wait);
 558         call = NULL;
 559         goto error_trace;
 560 }
 561
 562 /**
 563  * rxrpc_kernel_recv_data - Allow a kernel service to receive data/info
 564  * @sock: The socket that the call exists on
 565  * @call: The call to send data through
 566  * @iter: The buffer to receive into
 567  * @_len: The amount of data we want to receive (decreased on return)
 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  * @_service: Where to store the actual service ID (may be upgraded)
 571  *
 572  * Allow a kernel service to receive data and pick up information about the
 573  * state of a call.  Returns 0 if got what was asked for and there's more
 574  * available, 1 if we got what was asked for and we're at the end of the data
 575  * and -EAGAIN if we need more data.
 576  *
 577  * Note that we may return -EAGAIN to drain empty packets at the end of the
 578  * data, even if we've already copied over the requested data.
 579  *
 580  * *_abort should also be initialised to 0.
 581  */
 582 int rxrpc_kernel_recv_data(struct socket *sock, struct rxrpc_call *call,
 583                            struct iov_iter *iter, size_t *_len,
 584                            bool want_more, u32 *_abort, u16 *_service)
 585 {
 586         size_t offset = 0;
 587         int ret;
 588
 589         _enter("{%d,%s},%zu,%d",
 590                call->debug_id, rxrpc_call_states[call->state],
 591                *_len, want_more);
 592
 593         ASSERTCMP(call->state, !=, RXRPC_CALL_SERVER_SECURING);
 594
 595         mutex_lock(&call->user_mutex);
 596
 597         switch (READ_ONCE(call->state)) {
 598         case RXRPC_CALL_CLIENT_RECV_REPLY:
 599         case RXRPC_CALL_SERVER_RECV_REQUEST:
 600         case RXRPC_CALL_SERVER_ACK_REQUEST:
 601                 ret = rxrpc_recvmsg_data(sock, call, NULL, iter,
 602                                          *_len, 0, &offset);
 603                 *_len -= offset;
 604                 if (ret < 0)
 605                         goto out;
 606
 607                 /* We can only reach here with a partially full buffer if we
 608                  * have reached the end of the data.  We must otherwise have a
 609                  * full buffer or have been given -EAGAIN.
 610                  */
 611                 if (ret == 1) {
 612                         if (iov_iter_count(iter) > 0)
 613                                 goto short_data;
 614                         if (!want_more)
 615                                 goto read_phase_complete;
 616                         ret = 0;
 617                         goto out;
 618                 }
 619
 620                 if (!want_more)
 621                         goto excess_data;
 622                 goto out;
 623
 624         case RXRPC_CALL_COMPLETE:
 625                 goto call_complete;
 626
 627         default:
 628                 ret = -EINPROGRESS;
 629                 goto out;
 630         }
 631
 632 read_phase_complete:
 633         ret = 1;
 634 out:
 635         rxrpc_transmit_ack_packets(call->peer->local);
 636         if (_service)
 637                 *_service = call->dest_srx.srx_service;
 638         mutex_unlock(&call->user_mutex);
 639         _leave(" = %d [%zu,%d]", ret, iov_iter_count(iter), *_abort);
 640         return ret;
 641
 642 short_data:
 643         trace_rxrpc_rx_eproto(call, 0, tracepoint_string("short_data"));
 644         ret = -EBADMSG;
 645         goto out;
 646 excess_data:
 647         trace_rxrpc_rx_eproto(call, 0, tracepoint_string("excess_data"));
 648         ret = -EMSGSIZE;
 649         goto out;
 650 call_complete:
 651         *_abort = call->abort_code;
 652         ret = call->error;
 653         if (call->completion == RXRPC_CALL_SUCCEEDED) {
 654                 ret = 1;
 655                 if (iov_iter_count(iter) > 0)
 656                         ret = -ECONNRESET;
 657         }
 658         goto out;
 659 }
 660 EXPORT_SYMBOL(rxrpc_kernel_recv_data);