net/rxrpc/sendmsg.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* AF_RXRPC sendmsg() implementation.
   3  *
   4  * Copyright (C) 2007, 2016 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/gfp.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/export.h>
  14 #include <linux/sched/signal.h>
  15
  16 #include <net/sock.h>
  17 #include <net/af_rxrpc.h>
  18 #include "ar-internal.h"
  19
  20 /*
  21  * Propose an abort to be made in the I/O thread.
  22  */
  23 bool rxrpc_propose_abort(struct rxrpc_call *call, s32 abort_code, int error,
  24                          enum rxrpc_abort_reason why)
  25 {
  26         _enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
  27
  28         if (!call->send_abort && !rxrpc_call_is_complete(call)) {
  29                 call->send_abort_why = why;
  30                 call->send_abort_err = error;
  31                 call->send_abort_seq = 0;
  32                 /* Request abort locklessly vs rxrpc_input_call_event(). */
  33                 smp_store_release(&call->send_abort, abort_code);
  34                 rxrpc_poke_call(call, rxrpc_call_poke_abort);
  35                 return true;
  36         }
  37
  38         return false;
  39 }
  40
  41 /*
  42  * Wait for a call to become connected.  Interruption here doesn't cause the
  43  * call to be aborted.
  44  */
  45 static int rxrpc_wait_to_be_connected(struct rxrpc_call *call, long *timeo)
  46 {
  47         DECLARE_WAITQUEUE(myself, current);
  48         int ret = 0;
  49
  50         _enter("%d", call->debug_id);
  51
  52         if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
  53                 return call->error;
  54
  55         add_wait_queue_exclusive(&call->waitq, &myself);
  56
  57         for (;;) {
  58                 ret = call->error;
  59                 if (ret < 0)
  60                         break;
  61
  62                 switch (call->interruptibility) {
  63                 case RXRPC_INTERRUPTIBLE:
  64                 case RXRPC_PREINTERRUPTIBLE:
  65                         set_current_state(TASK_INTERRUPTIBLE);
  66                         break;
  67                 case RXRPC_UNINTERRUPTIBLE:
  68                 default:
  69                         set_current_state(TASK_UNINTERRUPTIBLE);
  70                         break;
  71                 }
  72                 if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN) {
  73                         ret = call->error;
  74                         break;
  75                 }
  76                 if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
  77                      call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
  78                     signal_pending(current)) {
  79                         ret = sock_intr_errno(*timeo);
  80                         break;
  81                 }
  82                 *timeo = schedule_timeout(*timeo);
  83         }
  84
  85         remove_wait_queue(&call->waitq, &myself);
  86         __set_current_state(TASK_RUNNING);
  87
  88         if (ret == 0 && rxrpc_call_is_complete(call))
  89                 ret = call->error;
  90
  91         _leave(" = %d", ret);
  92         return ret;
  93 }
  94
  95 /*
  96  * Return true if there's sufficient Tx queue space.
  97  */
  98 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
  99 {
 100         if (_tx_win)
 101                 *_tx_win = call->tx_bottom;
 102         return call->tx_prepared - call->tx_bottom < 256;
 103 }
 104
 105 /*
 106  * Wait for space to appear in the Tx queue or a signal to occur.
 107  */
 108 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
 109                                          struct rxrpc_call *call,
 110                                          long *timeo)
 111 {
 112         for (;;) {
 113                 set_current_state(TASK_INTERRUPTIBLE);
 114                 if (rxrpc_check_tx_space(call, NULL))
 115                         return 0;
 116
 117                 if (rxrpc_call_is_complete(call))
 118                         return call->error;
 119
 120                 if (signal_pending(current))
 121                         return sock_intr_errno(*timeo);
 122
 123                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 124                 *timeo = schedule_timeout(*timeo);
 125         }
 126 }
 127
 128 /*
 129  * Wait for space to appear in the Tx queue uninterruptibly, but with
 130  * a timeout of 2*RTT if no progress was made and a signal occurred.
 131  */
 132 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
 133                                             struct rxrpc_call *call)
 134 {
 135         rxrpc_seq_t tx_start, tx_win;
 136         signed long rtt, timeout;
 137
 138         rtt = READ_ONCE(call->peer->srtt_us) >> 3;
 139         rtt = usecs_to_jiffies(rtt) * 2;
 140         if (rtt < 2)
 141                 rtt = 2;
 142
 143         timeout = rtt;
 144         tx_start = smp_load_acquire(&call->acks_hard_ack);
 145
 146         for (;;) {
 147                 set_current_state(TASK_UNINTERRUPTIBLE);
 148
 149                 if (rxrpc_check_tx_space(call, &tx_win))
 150                         return 0;
 151
 152                 if (rxrpc_call_is_complete(call))
 153                         return call->error;
 154
 155                 if (timeout == 0 &&
 156                     tx_win == tx_start && signal_pending(current))
 157                         return -EINTR;
 158
 159                 if (tx_win != tx_start) {
 160                         timeout = rtt;
 161                         tx_start = tx_win;
 162                 }
 163
 164                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 165                 timeout = schedule_timeout(timeout);
 166         }
 167 }
 168
 169 /*
 170  * Wait for space to appear in the Tx queue uninterruptibly.
 171  */
 172 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
 173                                             struct rxrpc_call *call,
 174                                             long *timeo)
 175 {
 176         for (;;) {
 177                 set_current_state(TASK_UNINTERRUPTIBLE);
 178                 if (rxrpc_check_tx_space(call, NULL))
 179                         return 0;
 180
 181                 if (rxrpc_call_is_complete(call))
 182                         return call->error;
 183
 184                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 185                 *timeo = schedule_timeout(*timeo);
 186         }
 187 }
 188
 189 /*
 190  * wait for space to appear in the transmit/ACK window
 191  * - caller holds the socket locked
 192  */
 193 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 194                                     struct rxrpc_call *call,
 195                                     long *timeo,
 196                                     bool waitall)
 197 {
 198         DECLARE_WAITQUEUE(myself, current);
 199         int ret;
 200
 201         _enter(",{%u,%u,%u,%u}",
 202                call->tx_bottom, call->acks_hard_ack, call->tx_top, call->tx_winsize);
 203
 204         add_wait_queue(&call->waitq, &myself);
 205
 206         switch (call->interruptibility) {
 207         case RXRPC_INTERRUPTIBLE:
 208                 if (waitall)
 209                         ret = rxrpc_wait_for_tx_window_waitall(rx, call);
 210                 else
 211                         ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 212                 break;
 213         case RXRPC_PREINTERRUPTIBLE:
 214         case RXRPC_UNINTERRUPTIBLE:
 215         default:
 216                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
 217                 break;
 218         }
 219
 220         remove_wait_queue(&call->waitq, &myself);
 221         set_current_state(TASK_RUNNING);
 222         _leave(" = %d", ret);
 223         return ret;
 224 }
 225
 226 /*
 227  * Notify the owner of the call that the transmit phase is ended and the last
 228  * packet has been queued.
 229  */
 230 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 231                                 rxrpc_notify_end_tx_t notify_end_tx)
 232 {
 233         if (notify_end_tx)
 234                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 235 }
 236
 237 /*
 238  * Queue a DATA packet for transmission, set the resend timeout and send
 239  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 240  * in case the caller wants to do something with it.
 241  */
 242 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 243                                struct rxrpc_txbuf *txb,
 244                                rxrpc_notify_end_tx_t notify_end_tx)
 245 {
 246         rxrpc_seq_t seq = txb->seq;
 247         bool last = test_bit(RXRPC_TXBUF_LAST, &txb->flags), poke;
 248
 249         rxrpc_inc_stat(call->rxnet, stat_tx_data);
 250
 251         ASSERTCMP(txb->seq, ==, call->tx_prepared + 1);
 252
 253         /* We have to set the timestamp before queueing as the retransmit
 254          * algorithm can see the packet as soon as we queue it.
 255          */
 256         txb->last_sent = ktime_get_real();
 257
 258         if (last)
 259                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
 260         else
 261                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
 262
 263         /* Add the packet to the call's output buffer */
 264         spin_lock(&call->tx_lock);
 265         poke = list_empty(&call->tx_sendmsg);
 266         list_add_tail(&txb->call_link, &call->tx_sendmsg);
 267         call->tx_prepared = seq;
 268         if (last)
 269                 rxrpc_notify_end_tx(rx, call, notify_end_tx);
 270         spin_unlock(&call->tx_lock);
 271
 272         if (poke)
 273                 rxrpc_poke_call(call, rxrpc_call_poke_start);
 274 }
 275
 276 /*
 277  * send data through a socket
 278  * - must be called in process context
 279  * - The caller holds the call user access mutex, but not the socket lock.
 280  */
 281 static int rxrpc_send_data(struct rxrpc_sock *rx,
 282                            struct rxrpc_call *call,
 283                            struct msghdr *msg, size_t len,
 284                            rxrpc_notify_end_tx_t notify_end_tx,
 285                            bool *_dropped_lock)
 286 {
 287         struct rxrpc_txbuf *txb;
 288         struct sock *sk = &rx->sk;
 289         enum rxrpc_call_state state;
 290         long timeo;
 291         bool more = msg->msg_flags & MSG_MORE;
 292         int ret, copied = 0;
 293
 294         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 295
 296         ret = rxrpc_wait_to_be_connected(call, &timeo);
 297         if (ret < 0)
 298                 return ret;
 299
 300         if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
 301                 ret = rxrpc_init_client_conn_security(call->conn);
 302                 if (ret < 0)
 303                         return ret;
 304         }
 305
 306         /* this should be in poll */
 307         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 308
 309 reload:
 310         ret = -EPIPE;
 311         if (sk->sk_shutdown & SEND_SHUTDOWN)
 312                 goto maybe_error;
 313         state = rxrpc_call_state(call);
 314         ret = -ESHUTDOWN;
 315         if (state >= RXRPC_CALL_COMPLETE)
 316                 goto maybe_error;
 317         ret = -EPROTO;
 318         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 319             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 320             state != RXRPC_CALL_SERVER_SEND_REPLY) {
 321                 /* Request phase complete for this client call */
 322                 trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
 323                                   call->cid, call->call_id, call->rx_consumed,
 324                                   0, -EPROTO);
 325                 goto maybe_error;
 326         }
 327
 328         ret = -EMSGSIZE;
 329         if (call->tx_total_len != -1) {
 330                 if (len - copied > call->tx_total_len)
 331                         goto maybe_error;
 332                 if (!more && len - copied != call->tx_total_len)
 333                         goto maybe_error;
 334         }
 335
 336         txb = call->tx_pending;
 337         call->tx_pending = NULL;
 338         if (txb)
 339                 rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
 340
 341         do {
 342                 if (!txb) {
 343                         size_t remain, bufsize, chunk, offset;
 344
 345                         _debug("alloc");
 346
 347                         if (!rxrpc_check_tx_space(call, NULL))
 348                                 goto wait_for_space;
 349
 350                         /* Work out the maximum size of a packet.  Assume that
 351                          * the security header is going to be in the padded
 352                          * region (enc blocksize), but the trailer is not.
 353                          */
 354                         remain = more ? INT_MAX : msg_data_left(msg);
 355                         ret = call->conn->security->how_much_data(call, remain,
 356                                                                   &bufsize, &chunk, &offset);
 357                         if (ret < 0)
 358                                 goto maybe_error;
 359
 360                         _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
 361
 362                         /* create a buffer that we can retain until it's ACK'd */
 363                         ret = -ENOMEM;
 364                         txb = rxrpc_alloc_txbuf(call, RXRPC_PACKET_TYPE_DATA,
 365                                                 GFP_KERNEL);
 366                         if (!txb)
 367                                 goto maybe_error;
 368
 369                         txb->offset = offset;
 370                         txb->space -= offset;
 371                         txb->space = min_t(size_t, chunk, txb->space);
 372                 }
 373
 374                 _debug("append");
 375
 376                 /* append next segment of data to the current buffer */
 377                 if (msg_data_left(msg) > 0) {
 378                         size_t copy = min_t(size_t, txb->space, msg_data_left(msg));
 379
 380                         _debug("add %zu", copy);
 381                         if (!copy_from_iter_full(txb->data + txb->offset, copy,
 382                                                  &msg->msg_iter))
 383                                 goto efault;
 384                         _debug("added");
 385                         txb->space -= copy;
 386                         txb->len += copy;
 387                         txb->offset += copy;
 388                         copied += copy;
 389                         if (call->tx_total_len != -1)
 390                                 call->tx_total_len -= copy;
 391                 }
 392
 393                 /* check for the far side aborting the call or a network error
 394                  * occurring */
 395                 if (rxrpc_call_is_complete(call))
 396                         goto call_terminated;
 397
 398                 /* add the packet to the send queue if it's now full */
 399                 if (!txb->space ||
 400                     (msg_data_left(msg) == 0 && !more)) {
 401                         if (msg_data_left(msg) == 0 && !more) {
 402                                 txb->wire.flags |= RXRPC_LAST_PACKET;
 403                                 __set_bit(RXRPC_TXBUF_LAST, &txb->flags);
 404                         }
 405                         else if (call->tx_top - call->acks_hard_ack <
 406                                  call->tx_winsize)
 407                                 txb->wire.flags |= RXRPC_MORE_PACKETS;
 408
 409                         ret = call->security->secure_packet(call, txb);
 410                         if (ret < 0)
 411                                 goto out;
 412
 413                         rxrpc_queue_packet(rx, call, txb, notify_end_tx);
 414                         txb = NULL;
 415                 }
 416         } while (msg_data_left(msg) > 0);
 417
 418 success:
 419         ret = copied;
 420         if (rxrpc_call_is_complete(call) &&
 421             call->error < 0)
 422                 ret = call->error;
 423 out:
 424         call->tx_pending = txb;
 425         _leave(" = %d", ret);
 426         return ret;
 427
 428 call_terminated:
 429         rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
 430         _leave(" = %d", call->error);
 431         return call->error;
 432
 433 maybe_error:
 434         if (copied)
 435                 goto success;
 436         goto out;
 437
 438 efault:
 439         ret = -EFAULT;
 440         goto out;
 441
 442 wait_for_space:
 443         ret = -EAGAIN;
 444         if (msg->msg_flags & MSG_DONTWAIT)
 445                 goto maybe_error;
 446         mutex_unlock(&call->user_mutex);
 447         *_dropped_lock = true;
 448         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
 449                                        msg->msg_flags & MSG_WAITALL);
 450         if (ret < 0)
 451                 goto maybe_error;
 452         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
 453                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 454                         ret = sock_intr_errno(timeo);
 455                         goto maybe_error;
 456                 }
 457         } else {
 458                 mutex_lock(&call->user_mutex);
 459         }
 460         *_dropped_lock = false;
 461         goto reload;
 462 }
 463
 464 /*
 465  * extract control messages from the sendmsg() control buffer
 466  */
 467 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 468 {
 469         struct cmsghdr *cmsg;
 470         bool got_user_ID = false;
 471         int len;
 472
 473         if (msg->msg_controllen == 0)
 474                 return -EINVAL;
 475
 476         for_each_cmsghdr(cmsg, msg) {
 477                 if (!CMSG_OK(msg, cmsg))
 478                         return -EINVAL;
 479
 480                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 481                 _debug("CMSG %d, %d, %d",
 482                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 483
 484                 if (cmsg->cmsg_level != SOL_RXRPC)
 485                         continue;
 486
 487                 switch (cmsg->cmsg_type) {
 488                 case RXRPC_USER_CALL_ID:
 489                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 490                                 if (len != sizeof(u32))
 491                                         return -EINVAL;
 492                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 493                         } else {
 494                                 if (len != sizeof(unsigned long))
 495                                         return -EINVAL;
 496                                 p->call.user_call_ID = *(unsigned long *)
 497                                         CMSG_DATA(cmsg);
 498                         }
 499                         got_user_ID = true;
 500                         break;
 501
 502                 case RXRPC_ABORT:
 503                         if (p->command != RXRPC_CMD_SEND_DATA)
 504                                 return -EINVAL;
 505                         p->command = RXRPC_CMD_SEND_ABORT;
 506                         if (len != sizeof(p->abort_code))
 507                                 return -EINVAL;
 508                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 509                         if (p->abort_code == 0)
 510                                 return -EINVAL;
 511                         break;
 512
 513                 case RXRPC_CHARGE_ACCEPT:
 514                         if (p->command != RXRPC_CMD_SEND_DATA)
 515                                 return -EINVAL;
 516                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
 517                         if (len != 0)
 518                                 return -EINVAL;
 519                         break;
 520
 521                 case RXRPC_EXCLUSIVE_CALL:
 522                         p->exclusive = true;
 523                         if (len != 0)
 524                                 return -EINVAL;
 525                         break;
 526
 527                 case RXRPC_UPGRADE_SERVICE:
 528                         p->upgrade = true;
 529                         if (len != 0)
 530                                 return -EINVAL;
 531                         break;
 532
 533                 case RXRPC_TX_LENGTH:
 534                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 535                                 return -EINVAL;
 536                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 537                         if (p->call.tx_total_len < 0)
 538                                 return -EINVAL;
 539                         break;
 540
 541                 case RXRPC_SET_CALL_TIMEOUT:
 542                         if (len & 3 || len < 4 || len > 12)
 543                                 return -EINVAL;
 544                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 545                         p->call.nr_timeouts = len / 4;
 546                         if (p->call.timeouts.hard > INT_MAX / HZ)
 547                                 return -ERANGE;
 548                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 549                                 return -ERANGE;
 550                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 551                                 return -ERANGE;
 552                         break;
 553
 554                 default:
 555                         return -EINVAL;
 556                 }
 557         }
 558
 559         if (!got_user_ID)
 560                 return -EINVAL;
 561         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 562                 return -EINVAL;
 563         _leave(" = 0");
 564         return 0;
 565 }
 566
 567 /*
 568  * Create a new client call for sendmsg().
 569  * - Called with the socket lock held, which it must release.
 570  * - If it returns a call, the call's lock will need releasing by the caller.
 571  */
 572 static struct rxrpc_call *
 573 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 574                                   struct rxrpc_send_params *p)
 575         __releases(&rx->sk.sk_lock.slock)
 576         __acquires(&call->user_mutex)
 577 {
 578         struct rxrpc_conn_parameters cp;
 579         struct rxrpc_call *call;
 580         struct key *key;
 581
 582         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 583
 584         _enter("");
 585
 586         if (!msg->msg_name) {
 587                 release_sock(&rx->sk);
 588                 return ERR_PTR(-EDESTADDRREQ);
 589         }
 590
 591         key = rx->key;
 592         if (key && !rx->key->payload.data[0])
 593                 key = NULL;
 594
 595         memset(&cp, 0, sizeof(cp));
 596         cp.local                = rx->local;
 597         cp.key                  = rx->key;
 598         cp.security_level       = rx->min_sec_level;
 599         cp.exclusive            = rx->exclusive | p->exclusive;
 600         cp.upgrade              = p->upgrade;
 601         cp.service_id           = srx->srx_service;
 602         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 603                                      atomic_inc_return(&rxrpc_debug_id));
 604         /* The socket is now unlocked */
 605
 606         _leave(" = %p\n", call);
 607         return call;
 608 }
 609
 610 /*
 611  * send a message forming part of a client call through an RxRPC socket
 612  * - caller holds the socket locked
 613  * - the socket may be either a client socket or a server socket
 614  */
 615 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 616         __releases(&rx->sk.sk_lock.slock)
 617 {
 618         struct rxrpc_call *call;
 619         unsigned long now, j;
 620         bool dropped_lock = false;
 621         int ret;
 622
 623         struct rxrpc_send_params p = {
 624                 .call.tx_total_len      = -1,
 625                 .call.user_call_ID      = 0,
 626                 .call.nr_timeouts       = 0,
 627                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
 628                 .abort_code             = 0,
 629                 .command                = RXRPC_CMD_SEND_DATA,
 630                 .exclusive              = false,
 631                 .upgrade                = false,
 632         };
 633
 634         _enter("");
 635
 636         ret = rxrpc_sendmsg_cmsg(msg, &p);
 637         if (ret < 0)
 638                 goto error_release_sock;
 639
 640         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
 641                 ret = -EINVAL;
 642                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 643                         goto error_release_sock;
 644                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
 645                 goto error_release_sock;
 646         }
 647
 648         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 649         if (!call) {
 650                 ret = -EBADSLT;
 651                 if (p.command != RXRPC_CMD_SEND_DATA)
 652                         goto error_release_sock;
 653                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 654                 /* The socket is now unlocked... */
 655                 if (IS_ERR(call))
 656                         return PTR_ERR(call);
 657                 /* ... and we have the call lock. */
 658                 ret = 0;
 659                 if (rxrpc_call_is_complete(call))
 660                         goto out_put_unlock;
 661         } else {
 662                 switch (rxrpc_call_state(call)) {
 663                 case RXRPC_CALL_UNINITIALISED:
 664                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 665                 case RXRPC_CALL_SERVER_PREALLOC:
 666                 case RXRPC_CALL_SERVER_SECURING:
 667                         rxrpc_put_call(call, rxrpc_call_put_sendmsg);
 668                         ret = -EBUSY;
 669                         goto error_release_sock;
 670                 default:
 671                         break;
 672                 }
 673
 674                 ret = mutex_lock_interruptible(&call->user_mutex);
 675                 release_sock(&rx->sk);
 676                 if (ret < 0) {
 677                         ret = -ERESTARTSYS;
 678                         goto error_put;
 679                 }
 680
 681                 if (p.call.tx_total_len != -1) {
 682                         ret = -EINVAL;
 683                         if (call->tx_total_len != -1 ||
 684                             call->tx_pending ||
 685                             call->tx_top != 0)
 686                                 goto out_put_unlock;
 687                         call->tx_total_len = p.call.tx_total_len;
 688                 }
 689         }
 690
 691         switch (p.call.nr_timeouts) {
 692         case 3:
 693                 j = msecs_to_jiffies(p.call.timeouts.normal);
 694                 if (p.call.timeouts.normal > 0 && j == 0)
 695                         j = 1;
 696                 WRITE_ONCE(call->next_rx_timo, j);
 697                 fallthrough;
 698         case 2:
 699                 j = msecs_to_jiffies(p.call.timeouts.idle);
 700                 if (p.call.timeouts.idle > 0 && j == 0)
 701                         j = 1;
 702                 WRITE_ONCE(call->next_req_timo, j);
 703                 fallthrough;
 704         case 1:
 705                 if (p.call.timeouts.hard > 0) {
 706                         j = msecs_to_jiffies(p.call.timeouts.hard);
 707                         now = jiffies;
 708                         j += now;
 709                         WRITE_ONCE(call->expect_term_by, j);
 710                         rxrpc_reduce_call_timer(call, j, now,
 711                                                 rxrpc_timer_set_for_hard);
 712                 }
 713                 break;
 714         }
 715
 716         if (rxrpc_call_is_complete(call)) {
 717                 /* it's too late for this call */
 718                 ret = -ESHUTDOWN;
 719         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 720                 rxrpc_propose_abort(call, p.abort_code, -ECONNABORTED,
 721                                     rxrpc_abort_call_sendmsg);
 722                 ret = 0;
 723         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 724                 ret = -EINVAL;
 725         } else {
 726                 ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
 727         }
 728
 729 out_put_unlock:
 730         if (!dropped_lock)
 731                 mutex_unlock(&call->user_mutex);
 732 error_put:
 733         rxrpc_put_call(call, rxrpc_call_put_sendmsg);
 734         _leave(" = %d", ret);
 735         return ret;
 736
 737 error_release_sock:
 738         release_sock(&rx->sk);
 739         return ret;
 740 }
 741
 742 /**
 743  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 744  * @sock: The socket the call is on
 745  * @call: The call to send data through
 746  * @msg: The data to send
 747  * @len: The amount of data to send
 748  * @notify_end_tx: Notification that the last packet is queued.
 749  *
 750  * Allow a kernel service to send data on a call.  The call must be in an state
 751  * appropriate to sending data.  No control data should be supplied in @msg,
 752  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 753  * more data to come, otherwise this data will end the transmission phase.
 754  */
 755 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 756                            struct msghdr *msg, size_t len,
 757                            rxrpc_notify_end_tx_t notify_end_tx)
 758 {
 759         bool dropped_lock = false;
 760         int ret;
 761
 762         _enter("{%d},", call->debug_id);
 763
 764         ASSERTCMP(msg->msg_name, ==, NULL);
 765         ASSERTCMP(msg->msg_control, ==, NULL);
 766
 767         mutex_lock(&call->user_mutex);
 768
 769         ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 770                               notify_end_tx, &dropped_lock);
 771         if (ret == -ESHUTDOWN)
 772                 ret = call->error;
 773
 774         if (!dropped_lock)
 775                 mutex_unlock(&call->user_mutex);
 776         _leave(" = %d", ret);
 777         return ret;
 778 }
 779 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 780
 781 /**
 782  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 783  * @sock: The socket the call is on
 784  * @call: The call to be aborted
 785  * @abort_code: The abort code to stick into the ABORT packet
 786  * @error: Local error value
 787  * @why: Indication as to why.
 788  *
 789  * Allow a kernel service to abort a call, if it's still in an abortable state
 790  * and return true if the call was aborted, false if it was already complete.
 791  */
 792 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 793                              u32 abort_code, int error, enum rxrpc_abort_reason why)
 794 {
 795         bool aborted;
 796
 797         _enter("{%d},%d,%d,%u", call->debug_id, abort_code, error, why);
 798
 799         mutex_lock(&call->user_mutex);
 800         aborted = rxrpc_propose_abort(call, abort_code, error, why);
 801         mutex_unlock(&call->user_mutex);
 802         return aborted;
 803 }
 804 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 805
 806 /**
 807  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 808  * @sock: The socket the call is on
 809  * @call: The call to be informed
 810  * @tx_total_len: The amount of data to be transmitted for this call
 811  *
 812  * Allow a kernel service to set the total transmit length on a call.  This
 813  * allows buffer-to-packet encrypt-and-copy to be performed.
 814  *
 815  * This function is primarily for use for setting the reply length since the
 816  * request length can be set when beginning the call.
 817  */
 818 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 819                                 s64 tx_total_len)
 820 {
 821         WARN_ON(call->tx_total_len != -1);
 822         call->tx_total_len = tx_total_len;
 823 }
 824 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);