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  * Return true if there's sufficient Tx queue space.
  22  */
  23 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
  24 {
  25         unsigned int win_size;
  26         rxrpc_seq_t tx_win = smp_load_acquire(&call->acks_hard_ack);
  27
  28         /* If we haven't transmitted anything for >1RTT, we should reset the
  29          * congestion management state.
  30          */
  31         if (ktime_before(ktime_add_us(call->tx_last_sent,
  32                                       call->peer->srtt_us >> 3),
  33                          ktime_get_real())) {
  34                 if (RXRPC_TX_SMSS > 2190)
  35                         win_size = 2;
  36                 else if (RXRPC_TX_SMSS > 1095)
  37                         win_size = 3;
  38                 else
  39                         win_size = 4;
  40                 win_size += call->cong_extra;
  41         } else {
  42                 win_size = min_t(unsigned int, call->tx_winsize,
  43                                  call->cong_cwnd + call->cong_extra);
  44         }
  45
  46         if (_tx_win)
  47                 *_tx_win = tx_win;
  48         return call->tx_top - tx_win < win_size;
  49 }
  50
  51 /*
  52  * Wait for space to appear in the Tx queue or a signal to occur.
  53  */
  54 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
  55                                          struct rxrpc_call *call,
  56                                          long *timeo)
  57 {
  58         for (;;) {
  59                 set_current_state(TASK_INTERRUPTIBLE);
  60                 if (rxrpc_check_tx_space(call, NULL))
  61                         return 0;
  62
  63                 if (call->state >= RXRPC_CALL_COMPLETE)
  64                         return call->error;
  65
  66                 if (signal_pending(current))
  67                         return sock_intr_errno(*timeo);
  68
  69                 if (READ_ONCE(call->acks_hard_ack) != call->tx_bottom) {
  70                         rxrpc_shrink_call_tx_buffer(call);
  71                         continue;
  72                 }
  73
  74                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
  75                 *timeo = schedule_timeout(*timeo);
  76         }
  77 }
  78
  79 /*
  80  * Wait for space to appear in the Tx queue uninterruptibly, but with
  81  * a timeout of 2*RTT if no progress was made and a signal occurred.
  82  */
  83 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
  84                                             struct rxrpc_call *call)
  85 {
  86         rxrpc_seq_t tx_start, tx_win;
  87         signed long rtt, timeout;
  88
  89         rtt = READ_ONCE(call->peer->srtt_us) >> 3;
  90         rtt = usecs_to_jiffies(rtt) * 2;
  91         if (rtt < 2)
  92                 rtt = 2;
  93
  94         timeout = rtt;
  95         tx_start = smp_load_acquire(&call->acks_hard_ack);
  96
  97         for (;;) {
  98                 set_current_state(TASK_UNINTERRUPTIBLE);
  99
 100                 if (rxrpc_check_tx_space(call, &tx_win))
 101                         return 0;
 102
 103                 if (call->state >= RXRPC_CALL_COMPLETE)
 104                         return call->error;
 105
 106                 if (timeout == 0 &&
 107                     tx_win == tx_start && signal_pending(current))
 108                         return -EINTR;
 109
 110                 if (READ_ONCE(call->acks_hard_ack) != call->tx_bottom) {
 111                         rxrpc_shrink_call_tx_buffer(call);
 112                         continue;
 113                 }
 114
 115                 if (tx_win != tx_start) {
 116                         timeout = rtt;
 117                         tx_start = tx_win;
 118                 }
 119
 120                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 121                 timeout = schedule_timeout(timeout);
 122         }
 123 }
 124
 125 /*
 126  * Wait for space to appear in the Tx queue uninterruptibly.
 127  */
 128 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
 129                                             struct rxrpc_call *call,
 130                                             long *timeo)
 131 {
 132         for (;;) {
 133                 set_current_state(TASK_UNINTERRUPTIBLE);
 134                 if (rxrpc_check_tx_space(call, NULL))
 135                         return 0;
 136
 137                 if (call->state >= RXRPC_CALL_COMPLETE)
 138                         return call->error;
 139
 140                 if (READ_ONCE(call->acks_hard_ack) != call->tx_bottom) {
 141                         rxrpc_shrink_call_tx_buffer(call);
 142                         continue;
 143                 }
 144
 145                 trace_rxrpc_txqueue(call, rxrpc_txqueue_wait);
 146                 *timeo = schedule_timeout(*timeo);
 147         }
 148 }
 149
 150 /*
 151  * wait for space to appear in the transmit/ACK window
 152  * - caller holds the socket locked
 153  */
 154 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 155                                     struct rxrpc_call *call,
 156                                     long *timeo,
 157                                     bool waitall)
 158 {
 159         DECLARE_WAITQUEUE(myself, current);
 160         int ret;
 161
 162         _enter(",{%u,%u,%u,%u}",
 163                call->tx_bottom, call->acks_hard_ack, call->tx_top, call->tx_winsize);
 164
 165         add_wait_queue(&call->waitq, &myself);
 166
 167         switch (call->interruptibility) {
 168         case RXRPC_INTERRUPTIBLE:
 169                 if (waitall)
 170                         ret = rxrpc_wait_for_tx_window_waitall(rx, call);
 171                 else
 172                         ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 173                 break;
 174         case RXRPC_PREINTERRUPTIBLE:
 175         case RXRPC_UNINTERRUPTIBLE:
 176         default:
 177                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
 178                 break;
 179         }
 180
 181         remove_wait_queue(&call->waitq, &myself);
 182         set_current_state(TASK_RUNNING);
 183         _leave(" = %d", ret);
 184         return ret;
 185 }
 186
 187 /*
 188  * Notify the owner of the call that the transmit phase is ended and the last
 189  * packet has been queued.
 190  */
 191 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 192                                 rxrpc_notify_end_tx_t notify_end_tx)
 193 {
 194         if (notify_end_tx)
 195                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 196 }
 197
 198 /*
 199  * Queue a DATA packet for transmission, set the resend timeout and send
 200  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 201  * in case the caller wants to do something with it.
 202  */
 203 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 204                                struct rxrpc_txbuf *txb,
 205                                rxrpc_notify_end_tx_t notify_end_tx)
 206 {
 207         unsigned long now;
 208         rxrpc_seq_t seq = txb->seq;
 209         bool last = test_bit(RXRPC_TXBUF_LAST, &txb->flags);
 210         int ret;
 211
 212         rxrpc_inc_stat(call->rxnet, stat_tx_data);
 213
 214         ASSERTCMP(seq, ==, call->tx_top + 1);
 215
 216         /* We have to set the timestamp before queueing as the retransmit
 217          * algorithm can see the packet as soon as we queue it.
 218          */
 219         txb->last_sent = ktime_get_real();
 220
 221         /* Add the packet to the call's output buffer */
 222         rxrpc_get_txbuf(txb, rxrpc_txbuf_get_buffer);
 223         spin_lock(&call->tx_lock);
 224         list_add_tail(&txb->call_link, &call->tx_buffer);
 225         call->tx_top = seq;
 226         spin_unlock(&call->tx_lock);
 227
 228         if (last)
 229                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue_last);
 230         else
 231                 trace_rxrpc_txqueue(call, rxrpc_txqueue_queue);
 232
 233         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 234                 _debug("________awaiting reply/ACK__________");
 235                 write_lock_bh(&call->state_lock);
 236                 switch (call->state) {
 237                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 238                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 239                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 240                         break;
 241                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 242                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 243                         now = jiffies;
 244                         WRITE_ONCE(call->delay_ack_at, now + MAX_JIFFY_OFFSET);
 245                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 246                                 call->ackr_reason = 0;
 247                         trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
 248                         if (!last)
 249                                 break;
 250                         fallthrough;
 251                 case RXRPC_CALL_SERVER_SEND_REPLY:
 252                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 253                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 254                         break;
 255                 default:
 256                         break;
 257                 }
 258                 write_unlock_bh(&call->state_lock);
 259         }
 260
 261         if (seq == 1 && rxrpc_is_client_call(call))
 262                 rxrpc_expose_client_call(call);
 263
 264         ret = rxrpc_send_data_packet(call, txb);
 265         if (ret < 0) {
 266                 switch (ret) {
 267                 case -ENETUNREACH:
 268                 case -EHOSTUNREACH:
 269                 case -ECONNREFUSED:
 270                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 271                                                   0, ret);
 272                         goto out;
 273                 }
 274         } else {
 275                 unsigned long now = jiffies;
 276                 unsigned long resend_at = now + call->peer->rto_j;
 277
 278                 WRITE_ONCE(call->resend_at, resend_at);
 279                 rxrpc_reduce_call_timer(call, resend_at, now,
 280                                         rxrpc_timer_set_for_send);
 281         }
 282
 283 out:
 284         rxrpc_put_txbuf(txb, rxrpc_txbuf_put_trans);
 285 }
 286
 287 /*
 288  * send data through a socket
 289  * - must be called in process context
 290  * - The caller holds the call user access mutex, but not the socket lock.
 291  */
 292 static int rxrpc_send_data(struct rxrpc_sock *rx,
 293                            struct rxrpc_call *call,
 294                            struct msghdr *msg, size_t len,
 295                            rxrpc_notify_end_tx_t notify_end_tx,
 296                            bool *_dropped_lock)
 297 {
 298         struct rxrpc_txbuf *txb;
 299         struct sock *sk = &rx->sk;
 300         enum rxrpc_call_state state;
 301         long timeo;
 302         bool more = msg->msg_flags & MSG_MORE;
 303         int ret, copied = 0;
 304
 305         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 306
 307         /* this should be in poll */
 308         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 309
 310 reload:
 311         ret = -EPIPE;
 312         if (sk->sk_shutdown & SEND_SHUTDOWN)
 313                 goto maybe_error;
 314         state = READ_ONCE(call->state);
 315         ret = -ESHUTDOWN;
 316         if (state >= RXRPC_CALL_COMPLETE)
 317                 goto maybe_error;
 318         ret = -EPROTO;
 319         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 320             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 321             state != RXRPC_CALL_SERVER_SEND_REPLY)
 322                 goto maybe_error;
 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                 rxrpc_transmit_ack_packets(call->peer->local);
 339
 340                 if (!txb) {
 341                         size_t remain, bufsize, chunk, offset;
 342
 343                         _debug("alloc");
 344
 345                         if (!rxrpc_check_tx_space(call, NULL))
 346                                 goto wait_for_space;
 347
 348                         /* Work out the maximum size of a packet.  Assume that
 349                          * the security header is going to be in the padded
 350                          * region (enc blocksize), but the trailer is not.
 351                          */
 352                         remain = more ? INT_MAX : msg_data_left(msg);
 353                         ret = call->conn->security->how_much_data(call, remain,
 354                                                                   &bufsize, &chunk, &offset);
 355                         if (ret < 0)
 356                                 goto maybe_error;
 357
 358                         _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
 359
 360                         /* create a buffer that we can retain until it's ACK'd */
 361                         ret = -ENOMEM;
 362                         txb = rxrpc_alloc_txbuf(call, RXRPC_PACKET_TYPE_DATA,
 363                                                 GFP_KERNEL);
 364                         if (!txb)
 365                                 goto maybe_error;
 366
 367                         txb->offset = offset;
 368                         txb->space -= offset;
 369                         txb->space = min_t(size_t, chunk, txb->space);
 370                 }
 371
 372                 _debug("append");
 373
 374                 /* append next segment of data to the current buffer */
 375                 if (msg_data_left(msg) > 0) {
 376                         size_t copy = min_t(size_t, txb->space, msg_data_left(msg));
 377
 378                         _debug("add %zu", copy);
 379                         if (!copy_from_iter_full(txb->data + txb->offset, copy,
 380                                                  &msg->msg_iter))
 381                                 goto efault;
 382                         _debug("added");
 383                         txb->space -= copy;
 384                         txb->len += copy;
 385                         txb->offset += copy;
 386                         copied += copy;
 387                         if (call->tx_total_len != -1)
 388                                 call->tx_total_len -= copy;
 389                 }
 390
 391                 /* check for the far side aborting the call or a network error
 392                  * occurring */
 393                 if (call->state == RXRPC_CALL_COMPLETE)
 394                         goto call_terminated;
 395
 396                 /* add the packet to the send queue if it's now full */
 397                 if (!txb->space ||
 398                     (msg_data_left(msg) == 0 && !more)) {
 399                         if (msg_data_left(msg) == 0 && !more) {
 400                                 txb->wire.flags |= RXRPC_LAST_PACKET;
 401                                 __set_bit(RXRPC_TXBUF_LAST, &txb->flags);
 402                         }
 403                         else if (call->tx_top - call->acks_hard_ack <
 404                                  call->tx_winsize)
 405                                 txb->wire.flags |= RXRPC_MORE_PACKETS;
 406
 407                         ret = call->security->secure_packet(call, txb);
 408                         if (ret < 0)
 409                                 goto out;
 410
 411                         rxrpc_queue_packet(rx, call, txb, notify_end_tx);
 412                         txb = NULL;
 413                 }
 414         } while (msg_data_left(msg) > 0);
 415
 416 success:
 417         ret = copied;
 418         if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
 419                 read_lock_bh(&call->state_lock);
 420                 if (call->error < 0)
 421                         ret = call->error;
 422                 read_unlock_bh(&call->state_lock);
 423         }
 424 out:
 425         call->tx_pending = txb;
 426         _leave(" = %d", ret);
 427         return ret;
 428
 429 call_terminated:
 430         rxrpc_put_txbuf(txb, rxrpc_txbuf_put_send_aborted);
 431         _leave(" = %d", call->error);
 432         return call->error;
 433
 434 maybe_error:
 435         if (copied)
 436                 goto success;
 437         goto out;
 438
 439 efault:
 440         ret = -EFAULT;
 441         goto out;
 442
 443 wait_for_space:
 444         ret = -EAGAIN;
 445         if (msg->msg_flags & MSG_DONTWAIT)
 446                 goto maybe_error;
 447         mutex_unlock(&call->user_mutex);
 448         *_dropped_lock = true;
 449         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
 450                                        msg->msg_flags & MSG_WAITALL);
 451         if (ret < 0)
 452                 goto maybe_error;
 453         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
 454                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 455                         ret = sock_intr_errno(timeo);
 456                         goto maybe_error;
 457                 }
 458         } else {
 459                 mutex_lock(&call->user_mutex);
 460         }
 461         *_dropped_lock = false;
 462         goto reload;
 463 }
 464
 465 /*
 466  * extract control messages from the sendmsg() control buffer
 467  */
 468 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 469 {
 470         struct cmsghdr *cmsg;
 471         bool got_user_ID = false;
 472         int len;
 473
 474         if (msg->msg_controllen == 0)
 475                 return -EINVAL;
 476
 477         for_each_cmsghdr(cmsg, msg) {
 478                 if (!CMSG_OK(msg, cmsg))
 479                         return -EINVAL;
 480
 481                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 482                 _debug("CMSG %d, %d, %d",
 483                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 484
 485                 if (cmsg->cmsg_level != SOL_RXRPC)
 486                         continue;
 487
 488                 switch (cmsg->cmsg_type) {
 489                 case RXRPC_USER_CALL_ID:
 490                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 491                                 if (len != sizeof(u32))
 492                                         return -EINVAL;
 493                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 494                         } else {
 495                                 if (len != sizeof(unsigned long))
 496                                         return -EINVAL;
 497                                 p->call.user_call_ID = *(unsigned long *)
 498                                         CMSG_DATA(cmsg);
 499                         }
 500                         got_user_ID = true;
 501                         break;
 502
 503                 case RXRPC_ABORT:
 504                         if (p->command != RXRPC_CMD_SEND_DATA)
 505                                 return -EINVAL;
 506                         p->command = RXRPC_CMD_SEND_ABORT;
 507                         if (len != sizeof(p->abort_code))
 508                                 return -EINVAL;
 509                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 510                         if (p->abort_code == 0)
 511                                 return -EINVAL;
 512                         break;
 513
 514                 case RXRPC_CHARGE_ACCEPT:
 515                         if (p->command != RXRPC_CMD_SEND_DATA)
 516                                 return -EINVAL;
 517                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
 518                         if (len != 0)
 519                                 return -EINVAL;
 520                         break;
 521
 522                 case RXRPC_EXCLUSIVE_CALL:
 523                         p->exclusive = true;
 524                         if (len != 0)
 525                                 return -EINVAL;
 526                         break;
 527
 528                 case RXRPC_UPGRADE_SERVICE:
 529                         p->upgrade = true;
 530                         if (len != 0)
 531                                 return -EINVAL;
 532                         break;
 533
 534                 case RXRPC_TX_LENGTH:
 535                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 536                                 return -EINVAL;
 537                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 538                         if (p->call.tx_total_len < 0)
 539                                 return -EINVAL;
 540                         break;
 541
 542                 case RXRPC_SET_CALL_TIMEOUT:
 543                         if (len & 3 || len < 4 || len > 12)
 544                                 return -EINVAL;
 545                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 546                         p->call.nr_timeouts = len / 4;
 547                         if (p->call.timeouts.hard > INT_MAX / HZ)
 548                                 return -ERANGE;
 549                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 550                                 return -ERANGE;
 551                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 552                                 return -ERANGE;
 553                         break;
 554
 555                 default:
 556                         return -EINVAL;
 557                 }
 558         }
 559
 560         if (!got_user_ID)
 561                 return -EINVAL;
 562         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 563                 return -EINVAL;
 564         _leave(" = 0");
 565         return 0;
 566 }
 567
 568 /*
 569  * Create a new client call for sendmsg().
 570  * - Called with the socket lock held, which it must release.
 571  * - If it returns a call, the call's lock will need releasing by the caller.
 572  */
 573 static struct rxrpc_call *
 574 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 575                                   struct rxrpc_send_params *p)
 576         __releases(&rx->sk.sk_lock.slock)
 577         __acquires(&call->user_mutex)
 578 {
 579         struct rxrpc_conn_parameters cp;
 580         struct rxrpc_call *call;
 581         struct key *key;
 582
 583         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 584
 585         _enter("");
 586
 587         if (!msg->msg_name) {
 588                 release_sock(&rx->sk);
 589                 return ERR_PTR(-EDESTADDRREQ);
 590         }
 591
 592         key = rx->key;
 593         if (key && !rx->key->payload.data[0])
 594                 key = NULL;
 595
 596         memset(&cp, 0, sizeof(cp));
 597         cp.local                = rx->local;
 598         cp.key                  = rx->key;
 599         cp.security_level       = rx->min_sec_level;
 600         cp.exclusive            = rx->exclusive | p->exclusive;
 601         cp.upgrade              = p->upgrade;
 602         cp.service_id           = srx->srx_service;
 603         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 604                                      atomic_inc_return(&rxrpc_debug_id));
 605         /* The socket is now unlocked */
 606
 607         rxrpc_put_peer(cp.peer, rxrpc_peer_put_discard_tmp);
 608         _leave(" = %p\n", call);
 609         return call;
 610 }
 611
 612 /*
 613  * send a message forming part of a client call through an RxRPC socket
 614  * - caller holds the socket locked
 615  * - the socket may be either a client socket or a server socket
 616  */
 617 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 618         __releases(&rx->sk.sk_lock.slock)
 619 {
 620         enum rxrpc_call_state state;
 621         struct rxrpc_call *call;
 622         unsigned long now, j;
 623         bool dropped_lock = false;
 624         int ret;
 625
 626         struct rxrpc_send_params p = {
 627                 .call.tx_total_len      = -1,
 628                 .call.user_call_ID      = 0,
 629                 .call.nr_timeouts       = 0,
 630                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
 631                 .abort_code             = 0,
 632                 .command                = RXRPC_CMD_SEND_DATA,
 633                 .exclusive              = false,
 634                 .upgrade                = false,
 635         };
 636
 637         _enter("");
 638
 639         ret = rxrpc_sendmsg_cmsg(msg, &p);
 640         if (ret < 0)
 641                 goto error_release_sock;
 642
 643         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
 644                 ret = -EINVAL;
 645                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 646                         goto error_release_sock;
 647                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
 648                 goto error_release_sock;
 649         }
 650
 651         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 652         if (!call) {
 653                 ret = -EBADSLT;
 654                 if (p.command != RXRPC_CMD_SEND_DATA)
 655                         goto error_release_sock;
 656                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 657                 /* The socket is now unlocked... */
 658                 if (IS_ERR(call))
 659                         return PTR_ERR(call);
 660                 /* ... and we have the call lock. */
 661                 ret = 0;
 662                 if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
 663                         goto out_put_unlock;
 664         } else {
 665                 switch (READ_ONCE(call->state)) {
 666                 case RXRPC_CALL_UNINITIALISED:
 667                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 668                 case RXRPC_CALL_SERVER_PREALLOC:
 669                 case RXRPC_CALL_SERVER_SECURING:
 670                         rxrpc_put_call(call, rxrpc_call_put_sendmsg);
 671                         ret = -EBUSY;
 672                         goto error_release_sock;
 673                 default:
 674                         break;
 675                 }
 676
 677                 ret = mutex_lock_interruptible(&call->user_mutex);
 678                 release_sock(&rx->sk);
 679                 if (ret < 0) {
 680                         ret = -ERESTARTSYS;
 681                         goto error_put;
 682                 }
 683
 684                 if (p.call.tx_total_len != -1) {
 685                         ret = -EINVAL;
 686                         if (call->tx_total_len != -1 ||
 687                             call->tx_pending ||
 688                             call->tx_top != 0)
 689                                 goto error_put;
 690                         call->tx_total_len = p.call.tx_total_len;
 691                 }
 692         }
 693
 694         switch (p.call.nr_timeouts) {
 695         case 3:
 696                 j = msecs_to_jiffies(p.call.timeouts.normal);
 697                 if (p.call.timeouts.normal > 0 && j == 0)
 698                         j = 1;
 699                 WRITE_ONCE(call->next_rx_timo, j);
 700                 fallthrough;
 701         case 2:
 702                 j = msecs_to_jiffies(p.call.timeouts.idle);
 703                 if (p.call.timeouts.idle > 0 && j == 0)
 704                         j = 1;
 705                 WRITE_ONCE(call->next_req_timo, j);
 706                 fallthrough;
 707         case 1:
 708                 if (p.call.timeouts.hard > 0) {
 709                         j = msecs_to_jiffies(p.call.timeouts.hard);
 710                         now = jiffies;
 711                         j += now;
 712                         WRITE_ONCE(call->expect_term_by, j);
 713                         rxrpc_reduce_call_timer(call, j, now,
 714                                                 rxrpc_timer_set_for_hard);
 715                 }
 716                 break;
 717         }
 718
 719         state = READ_ONCE(call->state);
 720         _debug("CALL %d USR %lx ST %d on CONN %p",
 721                call->debug_id, call->user_call_ID, state, call->conn);
 722
 723         if (state >= RXRPC_CALL_COMPLETE) {
 724                 /* it's too late for this call */
 725                 ret = -ESHUTDOWN;
 726         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 727                 ret = 0;
 728                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 729                         ret = rxrpc_send_abort_packet(call);
 730         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 731                 ret = -EINVAL;
 732         } else {
 733                 ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
 734         }
 735
 736 out_put_unlock:
 737         if (!dropped_lock)
 738                 mutex_unlock(&call->user_mutex);
 739 error_put:
 740         rxrpc_put_call(call, rxrpc_call_put_sendmsg);
 741         _leave(" = %d", ret);
 742         return ret;
 743
 744 error_release_sock:
 745         release_sock(&rx->sk);
 746         return ret;
 747 }
 748
 749 /**
 750  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 751  * @sock: The socket the call is on
 752  * @call: The call to send data through
 753  * @msg: The data to send
 754  * @len: The amount of data to send
 755  * @notify_end_tx: Notification that the last packet is queued.
 756  *
 757  * Allow a kernel service to send data on a call.  The call must be in an state
 758  * appropriate to sending data.  No control data should be supplied in @msg,
 759  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 760  * more data to come, otherwise this data will end the transmission phase.
 761  */
 762 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 763                            struct msghdr *msg, size_t len,
 764                            rxrpc_notify_end_tx_t notify_end_tx)
 765 {
 766         bool dropped_lock = false;
 767         int ret;
 768
 769         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 770
 771         ASSERTCMP(msg->msg_name, ==, NULL);
 772         ASSERTCMP(msg->msg_control, ==, NULL);
 773
 774         mutex_lock(&call->user_mutex);
 775
 776         _debug("CALL %d USR %lx ST %d on CONN %p",
 777                call->debug_id, call->user_call_ID, call->state, call->conn);
 778
 779         switch (READ_ONCE(call->state)) {
 780         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 781         case RXRPC_CALL_SERVER_ACK_REQUEST:
 782         case RXRPC_CALL_SERVER_SEND_REPLY:
 783                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 784                                       notify_end_tx, &dropped_lock);
 785                 break;
 786         case RXRPC_CALL_COMPLETE:
 787                 read_lock_bh(&call->state_lock);
 788                 ret = call->error;
 789                 read_unlock_bh(&call->state_lock);
 790                 break;
 791         default:
 792                 /* Request phase complete for this client call */
 793                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 794                 ret = -EPROTO;
 795                 break;
 796         }
 797
 798         if (!dropped_lock)
 799                 mutex_unlock(&call->user_mutex);
 800         _leave(" = %d", ret);
 801         return ret;
 802 }
 803 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 804
 805 /**
 806  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 807  * @sock: The socket the call is on
 808  * @call: The call to be aborted
 809  * @abort_code: The abort code to stick into the ABORT packet
 810  * @error: Local error value
 811  * @why: 3-char string indicating why.
 812  *
 813  * Allow a kernel service to abort a call, if it's still in an abortable state
 814  * and return true if the call was aborted, false if it was already complete.
 815  */
 816 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 817                              u32 abort_code, int error, const char *why)
 818 {
 819         bool aborted;
 820
 821         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 822
 823         mutex_lock(&call->user_mutex);
 824
 825         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 826         if (aborted)
 827                 rxrpc_send_abort_packet(call);
 828
 829         mutex_unlock(&call->user_mutex);
 830         return aborted;
 831 }
 832 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 833
 834 /**
 835  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 836  * @sock: The socket the call is on
 837  * @call: The call to be informed
 838  * @tx_total_len: The amount of data to be transmitted for this call
 839  *
 840  * Allow a kernel service to set the total transmit length on a call.  This
 841  * allows buffer-to-packet encrypt-and-copy to be performed.
 842  *
 843  * This function is primarily for use for setting the reply length since the
 844  * request length can be set when beginning the call.
 845  */
 846 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 847                                 s64 tx_total_len)
 848 {
 849         WARN_ON(call->tx_total_len != -1);
 850         call->tx_total_len = tx_total_len;
 851 }
 852 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);