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                 goto no_wait;
  54
  55         add_wait_queue_exclusive(&call->waitq, &myself);
  56
  57         for (;;) {
  58                 switch (call->interruptibility) {
  59                 case RXRPC_INTERRUPTIBLE:
  60                 case RXRPC_PREINTERRUPTIBLE:
  61                         set_current_state(TASK_INTERRUPTIBLE);
  62                         break;
  63                 case RXRPC_UNINTERRUPTIBLE:
  64                 default:
  65                         set_current_state(TASK_UNINTERRUPTIBLE);
  66                         break;
  67                 }
  68
  69                 if (rxrpc_call_state(call) != RXRPC_CALL_CLIENT_AWAIT_CONN)
  70                         break;
  71                 if ((call->interruptibility == RXRPC_INTERRUPTIBLE ||
  72                      call->interruptibility == RXRPC_PREINTERRUPTIBLE) &&
  73                     signal_pending(current)) {
  74                         ret = sock_intr_errno(*timeo);
  75                         break;
  76                 }
  77                 *timeo = schedule_timeout(*timeo);
  78         }
  79
  80         remove_wait_queue(&call->waitq, &myself);
  81         __set_current_state(TASK_RUNNING);
  82
  83 no_wait:
  84         if (ret == 0 && rxrpc_call_is_complete(call))
  85                 ret = call->error;
  86
  87         _leave(" = %d", ret);
  88         return ret;
  89 }
  90
  91 /*
  92  * Return true if there's sufficient Tx queue space.
  93  */
  94 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
  95 {
  96         if (_tx_win)
  97                 *_tx_win = call->tx_bottom;
  98         return call->tx_prepared - call->tx_bottom < 256;
  99 }
 100
 101 /*
 102  * Wait for space to appear in the Tx queue or a signal to occur.
 103  */
 104 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
 105                                          struct rxrpc_call *call,
 106                                          long *timeo)
 107 {
 108         for (;;) {
 109                 set_current_state(TASK_INTERRUPTIBLE);
 110                 if (rxrpc_check_tx_space(call, NULL))
 111                         return 0;
 112
 113                 if (rxrpc_call_is_complete(call))
 114                         return call->error;
 115
 116                 if (signal_pending(current))
 117                         return sock_intr_errno(*timeo);
 118
 119                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 120                 *timeo = schedule_timeout(*timeo);
 121         }
 122 }
 123
 124 /*
 125  * Wait for space to appear in the Tx queue uninterruptibly, but with
 126  * a timeout of 2*RTT if no progress was made and a signal occurred.
 127  */
 128 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
 129                                             struct rxrpc_call *call)
 130 {
 131         rxrpc_seq_t tx_start, tx_win;
 132         signed long rtt, timeout;
 133
 134         rtt = READ_ONCE(call->peer->srtt_us) >> 3;
 135         rtt = usecs_to_jiffies(rtt) * 2;
 136         if (rtt < 2)
 137                 rtt = 2;
 138
 139         timeout = rtt;
 140         tx_start = smp_load_acquire(&call->acks_hard_ack);
 141
 142         for (;;) {
 143                 set_current_state(TASK_UNINTERRUPTIBLE);
 144
 145                 if (rxrpc_check_tx_space(call, &tx_win))
 146                         return 0;
 147
 148                 if (rxrpc_call_is_complete(call))
 149                         return call->error;
 150
 151                 if (timeout == 0 &&
 152                     tx_win == tx_start && signal_pending(current))
 153                         return -EINTR;
 154
 155                 if (tx_win != tx_start) {
 156                         timeout = rtt;
 157                         tx_start = tx_win;
 158                 }
 159
 160                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 161                 timeout = schedule_timeout(timeout);
 162         }
 163 }
 164
 165 /*
 166  * Wait for space to appear in the Tx queue uninterruptibly.
 167  */
 168 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
 169                                             struct rxrpc_call *call,
 170                                             long *timeo)
 171 {
 172         for (;;) {
 173                 set_current_state(TASK_UNINTERRUPTIBLE);
 174                 if (rxrpc_check_tx_space(call, NULL))
 175                         return 0;
 176
 177                 if (rxrpc_call_is_complete(call))
 178                         return call->error;
 179
 180                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 181                 *timeo = schedule_timeout(*timeo);
 182         }
 183 }
 184
 185 /*
 186  * wait for space to appear in the transmit/ACK window
 187  * - caller holds the socket locked
 188  */
 189 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 190                                     struct rxrpc_call *call,
 191                                     long *timeo,
 192                                     bool waitall)
 193 {
 194         DECLARE_WAITQUEUE(myself, current);
 195         int ret;
 196
 197         _enter(",{%u,%u,%u,%u}",
 198                call->tx_bottom, call->acks_hard_ack, call->tx_top, call->tx_winsize);
 199
 200         add_wait_queue(&call->waitq, &myself);
 201
 202         switch (call->interruptibility) {
 203         case RXRPC_INTERRUPTIBLE:
 204                 if (waitall)
 205                         ret = rxrpc_wait_for_tx_window_waitall(rx, call);
 206                 else
 207                         ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 208                 break;
 209         case RXRPC_PREINTERRUPTIBLE:
 210         case RXRPC_UNINTERRUPTIBLE:
 211         default:
 212                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
 213                 break;
 214         }
 215
 216         remove_wait_queue(&call->waitq, &myself);
 217         set_current_state(TASK_RUNNING);
 218         _leave(" = %d", ret);
 219         return ret;
 220 }
 221
 222 /*
 223  * Notify the owner of the call that the transmit phase is ended and the last
 224  * packet has been queued.
 225  */
 226 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 227                                 rxrpc_notify_end_tx_t notify_end_tx)
 228 {
 229         if (notify_end_tx)
 230                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 231 }
 232
 233 /*
 234  * Queue a DATA packet for transmission, set the resend timeout and send
 235  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 236  * in case the caller wants to do something with it.
 237  */
 238 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 239                                struct rxrpc_txbuf *txb,
 240                                rxrpc_notify_end_tx_t notify_end_tx)
 241 {
 242         rxrpc_seq_t seq = txb->seq;
 243         bool last = test_bit(RXRPC_TXBUF_LAST, &txb->flags), poke;
 244
 245         rxrpc_inc_stat(call->rxnet, stat_tx_data);
 246
 247         ASSERTCMP(txb->seq, ==, call->tx_prepared + 1);
 248
 249         /* We have to set the timestamp before queueing as the retransmit
 250          * algorithm can see the packet as soon as we queue it.
 251          */
 252         txb->last_sent = ktime_get_real();
 253
 254         if (last)
 255                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
 256         else
 257                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
 258
 259         /* Add the packet to the call's output buffer */
 260         spin_lock(&call->tx_lock);
 261         poke = list_empty(&call->tx_sendmsg);
 262         list_add_tail(&txb->call_link, &call->tx_sendmsg);
 263         call->tx_prepared = seq;
 264         if (last)
 265                 rxrpc_notify_end_tx(rx, call, notify_end_tx);
 266         spin_unlock(&call->tx_lock);
 267
 268         if (poke)
 269                 rxrpc_poke_call(call, rxrpc_call_poke_start);
 270 }
 271
 272 /*
 273  * send data through a socket
 274  * - must be called in process context
 275  * - The caller holds the call user access mutex, but not the socket lock.
 276  */
 277 static int rxrpc_send_data(struct rxrpc_sock *rx,
 278                            struct rxrpc_call *call,
 279                            struct msghdr *msg, size_t len,
 280                            rxrpc_notify_end_tx_t notify_end_tx,
 281                            bool *_dropped_lock)
 282 {
 283         struct rxrpc_txbuf *txb;
 284         struct sock *sk = &rx->sk;
 285         enum rxrpc_call_state state;
 286         long timeo;
 287         bool more = msg->msg_flags & MSG_MORE;
 288         int ret, copied = 0;
 289
 290         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 291
 292         ret = rxrpc_wait_to_be_connected(call, &timeo);
 293         if (ret < 0)
 294                 return ret;
 295
 296         if (call->conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
 297                 ret = rxrpc_init_client_conn_security(call->conn);
 298                 if (ret < 0)
 299                         return ret;
 300         }
 301
 302         /* this should be in poll */
 303         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 304
 305 reload:
 306         ret = -EPIPE;
 307         if (sk->sk_shutdown & SEND_SHUTDOWN)
 308                 goto maybe_error;
 309         state = rxrpc_call_state(call);
 310         ret = -ESHUTDOWN;
 311         if (state >= RXRPC_CALL_COMPLETE)
 312                 goto maybe_error;
 313         ret = -EPROTO;
 314         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 315             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 316             state != RXRPC_CALL_SERVER_SEND_REPLY) {
 317                 /* Request phase complete for this client call */
 318                 trace_rxrpc_abort(call->debug_id, rxrpc_sendmsg_late_send,
 319                                   call->cid, call->call_id, call->rx_consumed,
 320                                   0, -EPROTO);
 321                 goto maybe_error;
 322         }
 323
 324         ret = -EMSGSIZE;
 325         if (call->tx_total_len != -1) {
 326                 if (len - copied > call->tx_total_len)
 327                         goto maybe_error;
 328                 if (!more && len - copied != call->tx_total_len)
 329                         goto maybe_error;
 330         }
 331
 332         txb = call->tx_pending;
 333         call->tx_pending = NULL;
 334         if (txb)
 335                 rxrpc_see_txbuf(txb, rxrpc_txbuf_see_send_more);
 336
 337         do {
 338                 if (!txb) {
 339                         size_t remain, bufsize, chunk, offset;
 340
 341                         _debug("alloc");
 342
 343                         if (!rxrpc_check_tx_space(call, NULL))
 344                                 goto wait_for_space;
 345
 346                         /* Work out the maximum size of a packet.  Assume that
 347                          * the security header is going to be in the padded
 348                          * region (enc blocksize), but the trailer is not.
 349                          */
 350                         remain = more ? INT_MAX : msg_data_left(msg);
 351                         ret = call->conn->security->how_much_data(call, remain,
 352                                                                   &bufsize, &chunk, &offset);
 353                         if (ret < 0)
 354                                 goto maybe_error;
 355
 356                         _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
 357
 358                         /* create a buffer that we can retain until it's ACK'd */
 359                         ret = -ENOMEM;
 360                         txb = rxrpc_alloc_txbuf(call, RXRPC_PACKET_TYPE_DATA,
 361                                                 GFP_KERNEL);
 362                         if (!txb)
 363                                 goto maybe_error;
 364
 365                         txb->offset = offset;
 366                         txb->space -= offset;
 367                         txb->space = min_t(size_t, chunk, txb->space);
 368                 }
 369
 370                 _debug("append");
 371
 372                 /* append next segment of data to the current buffer */
 373                 if (msg_data_left(msg) > 0) {
 374                         size_t copy = min_t(size_t, txb->space, msg_data_left(msg));
 375
 376                         _debug("add %zu", copy);
 377                         if (!copy_from_iter_full(txb->data + txb->offset, copy,
 378                                                  &msg->msg_iter))
 379                                 goto efault;
 380                         _debug("added");
 381                         txb->space -= copy;
 382                         txb->len += copy;
 383                         txb->offset += copy;
 384                         copied += copy;
 385                         if (call->tx_total_len != -1)
 386                                 call->tx_total_len -= copy;
 387                 }
 388
 389                 /* check for the far side aborting the call or a network error
 390                  * occurring */
 391                 if (rxrpc_call_is_complete(call))
 392                         goto call_terminated;
 393
 394                 /* add the packet to the send queue if it's now full */
 395                 if (!txb->space ||
 396                     (msg_data_left(msg) == 0 && !more)) {
 397                         if (msg_data_left(msg) == 0 && !more) {
 398                                 txb->wire.flags |= RXRPC_LAST_PACKET;
 399                                 __set_bit(RXRPC_TXBUF_LAST, &txb->flags);
 400                         }
 401                         else if (call->tx_top - call->acks_hard_ack <
 402                                  call->tx_winsize)
 403                                 txb->wire.flags |= RXRPC_MORE_PACKETS;
 404
 405                         ret = call->security->secure_packet(call, txb);
 406                         if (ret < 0)
 407                                 goto out;
 408
 409                         rxrpc_queue_packet(rx, call, txb, notify_end_tx);
 410                         txb = NULL;
 411                 }
 412         } while (msg_data_left(msg) > 0);
 413
 414 success:
 415         ret = copied;
 416         if (rxrpc_call_is_complete(call) &&
 417             call->error < 0)
 418                 ret = call->error;
 419 out:
 420         call->tx_pending = txb;
 421         _leave(" = %d", ret);
 422         return ret;
 423
 424 call_terminated:
 425         rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
 426         _leave(" = %d", call->error);
 427         return call->error;
 428
 429 maybe_error:
 430         if (copied)
 431                 goto success;
 432         goto out;
 433
 434 efault:
 435         ret = -EFAULT;
 436         goto out;
 437
 438 wait_for_space:
 439         ret = -EAGAIN;
 440         if (msg->msg_flags & MSG_DONTWAIT)
 441                 goto maybe_error;
 442         mutex_unlock(&call->user_mutex);
 443         *_dropped_lock = true;
 444         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
 445                                        msg->msg_flags & MSG_WAITALL);
 446         if (ret < 0)
 447                 goto maybe_error;
 448         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
 449                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 450                         ret = sock_intr_errno(timeo);
 451                         goto maybe_error;
 452                 }
 453         } else {
 454                 mutex_lock(&call->user_mutex);
 455         }
 456         *_dropped_lock = false;
 457         goto reload;
 458 }
 459
 460 /*
 461  * extract control messages from the sendmsg() control buffer
 462  */
 463 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 464 {
 465         struct cmsghdr *cmsg;
 466         bool got_user_ID = false;
 467         int len;
 468
 469         if (msg->msg_controllen == 0)
 470                 return -EINVAL;
 471
 472         for_each_cmsghdr(cmsg, msg) {
 473                 if (!CMSG_OK(msg, cmsg))
 474                         return -EINVAL;
 475
 476                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 477                 _debug("CMSG %d, %d, %d",
 478                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 479
 480                 if (cmsg->cmsg_level != SOL_RXRPC)
 481                         continue;
 482
 483                 switch (cmsg->cmsg_type) {
 484                 case RXRPC_USER_CALL_ID:
 485                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 486                                 if (len != sizeof(u32))
 487                                         return -EINVAL;
 488                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 489                         } else {
 490                                 if (len != sizeof(unsigned long))
 491                                         return -EINVAL;
 492                                 p->call.user_call_ID = *(unsigned long *)
 493                                         CMSG_DATA(cmsg);
 494                         }
 495                         got_user_ID = true;
 496                         break;
 497
 498                 case RXRPC_ABORT:
 499                         if (p->command != RXRPC_CMD_SEND_DATA)
 500                                 return -EINVAL;
 501                         p->command = RXRPC_CMD_SEND_ABORT;
 502                         if (len != sizeof(p->abort_code))
 503                                 return -EINVAL;
 504                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 505                         if (p->abort_code == 0)
 506                                 return -EINVAL;
 507                         break;
 508
 509                 case RXRPC_CHARGE_ACCEPT:
 510                         if (p->command != RXRPC_CMD_SEND_DATA)
 511                                 return -EINVAL;
 512                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
 513                         if (len != 0)
 514                                 return -EINVAL;
 515                         break;
 516
 517                 case RXRPC_EXCLUSIVE_CALL:
 518                         p->exclusive = true;
 519                         if (len != 0)
 520                                 return -EINVAL;
 521                         break;
 522
 523                 case RXRPC_UPGRADE_SERVICE:
 524                         p->upgrade = true;
 525                         if (len != 0)
 526                                 return -EINVAL;
 527                         break;
 528
 529                 case RXRPC_TX_LENGTH:
 530                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 531                                 return -EINVAL;
 532                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 533                         if (p->call.tx_total_len < 0)
 534                                 return -EINVAL;
 535                         break;
 536
 537                 case RXRPC_SET_CALL_TIMEOUT:
 538                         if (len & 3 || len < 4 || len > 12)
 539                                 return -EINVAL;
 540                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 541                         p->call.nr_timeouts = len / 4;
 542                         if (p->call.timeouts.hard > INT_MAX / HZ)
 543                                 return -ERANGE;
 544                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 545                                 return -ERANGE;
 546                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 547                                 return -ERANGE;
 548                         break;
 549
 550                 default:
 551                         return -EINVAL;
 552                 }
 553         }
 554
 555         if (!got_user_ID)
 556                 return -EINVAL;
 557         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 558                 return -EINVAL;
 559         _leave(" = 0");
 560         return 0;
 561 }
 562
 563 /*
 564  * Create a new client call for sendmsg().
 565  * - Called with the socket lock held, which it must release.
 566  * - If it returns a call, the call's lock will need releasing by the caller.
 567  */
 568 static struct rxrpc_call *
 569 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 570                                   struct rxrpc_send_params *p)
 571         __releases(&rx->sk.sk_lock.slock)
 572         __acquires(&call->user_mutex)
 573 {
 574         struct rxrpc_conn_parameters cp;
 575         struct rxrpc_call *call;
 576         struct key *key;
 577
 578         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 579
 580         _enter("");
 581
 582         if (!msg->msg_name) {
 583                 release_sock(&rx->sk);
 584                 return ERR_PTR(-EDESTADDRREQ);
 585         }
 586
 587         key = rx->key;
 588         if (key && !rx->key->payload.data[0])
 589                 key = NULL;
 590
 591         memset(&cp, 0, sizeof(cp));
 592         cp.local                = rx->local;
 593         cp.key                  = rx->key;
 594         cp.security_level       = rx->min_sec_level;
 595         cp.exclusive            = rx->exclusive | p->exclusive;
 596         cp.upgrade              = p->upgrade;
 597         cp.service_id           = srx->srx_service;
 598         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 599                                      atomic_inc_return(&rxrpc_debug_id));
 600         /* The socket is now unlocked */
 601
 602         _leave(" = %p\n", call);
 603         return call;
 604 }
 605
 606 /*
 607  * send a message forming part of a client call through an RxRPC socket
 608  * - caller holds the socket locked
 609  * - the socket may be either a client socket or a server socket
 610  */
 611 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 612         __releases(&rx->sk.sk_lock.slock)
 613 {
 614         struct rxrpc_call *call;
 615         unsigned long now, j;
 616         bool dropped_lock = false;
 617         int ret;
 618
 619         struct rxrpc_send_params p = {
 620                 .call.tx_total_len      = -1,
 621                 .call.user_call_ID      = 0,
 622                 .call.nr_timeouts       = 0,
 623                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
 624                 .abort_code             = 0,
 625                 .command                = RXRPC_CMD_SEND_DATA,
 626                 .exclusive              = false,
 627                 .upgrade                = false,
 628         };
 629
 630         _enter("");
 631
 632         ret = rxrpc_sendmsg_cmsg(msg, &p);
 633         if (ret < 0)
 634                 goto error_release_sock;
 635
 636         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
 637                 ret = -EINVAL;
 638                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 639                         goto error_release_sock;
 640                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
 641                 goto error_release_sock;
 642         }
 643
 644         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 645         if (!call) {
 646                 ret = -EBADSLT;
 647                 if (p.command != RXRPC_CMD_SEND_DATA)
 648                         goto error_release_sock;
 649                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 650                 /* The socket is now unlocked... */
 651                 if (IS_ERR(call))
 652                         return PTR_ERR(call);
 653                 /* ... and we have the call lock. */
 654                 p.call.nr_timeouts = 0;
 655                 ret = 0;
 656                 if (rxrpc_call_is_complete(call))
 657                         goto out_put_unlock;
 658         } else {
 659                 switch (rxrpc_call_state(call)) {
 660                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 661                 case RXRPC_CALL_SERVER_SECURING:
 662                         if (p.command == RXRPC_CMD_SEND_ABORT)
 663                                 break;
 664                         fallthrough;
 665                 case RXRPC_CALL_UNINITIALISED:
 666                 case RXRPC_CALL_SERVER_PREALLOC:
 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 = p.call.timeouts.hard * HZ;
 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);