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                 min_t(unsigned int, call->tx_winsize,
  27                       call->cong_cwnd + call->cong_extra);
  28         rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
  29
  30         if (_tx_win)
  31                 *_tx_win = tx_win;
  32         return call->tx_top - tx_win < win_size;
  33 }
  34
  35 /*
  36  * Wait for space to appear in the Tx queue or a signal to occur.
  37  */
  38 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
  39                                          struct rxrpc_call *call,
  40                                          long *timeo)
  41 {
  42         for (;;) {
  43                 set_current_state(TASK_INTERRUPTIBLE);
  44                 if (rxrpc_check_tx_space(call, NULL))
  45                         return 0;
  46
  47                 if (call->state >= RXRPC_CALL_COMPLETE)
  48                         return call->error;
  49
  50                 if (signal_pending(current))
  51                         return sock_intr_errno(*timeo);
  52
  53                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  54                 *timeo = schedule_timeout(*timeo);
  55         }
  56 }
  57
  58 /*
  59  * Wait for space to appear in the Tx queue uninterruptibly, but with
  60  * a timeout of 2*RTT if no progress was made and a signal occurred.
  61  */
  62 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
  63                                             struct rxrpc_call *call)
  64 {
  65         rxrpc_seq_t tx_start, tx_win;
  66         signed long rtt, timeout;
  67
  68         rtt = READ_ONCE(call->peer->srtt_us) >> 3;
  69         rtt = usecs_to_jiffies(rtt) * 2;
  70         if (rtt < 2)
  71                 rtt = 2;
  72
  73         timeout = rtt;
  74         tx_start = READ_ONCE(call->tx_hard_ack);
  75
  76         for (;;) {
  77                 set_current_state(TASK_UNINTERRUPTIBLE);
  78
  79                 tx_win = READ_ONCE(call->tx_hard_ack);
  80                 if (rxrpc_check_tx_space(call, &tx_win))
  81                         return 0;
  82
  83                 if (call->state >= RXRPC_CALL_COMPLETE)
  84                         return call->error;
  85
  86                 if (timeout == 0 &&
  87                     tx_win == tx_start && signal_pending(current))
  88                         return -EINTR;
  89
  90                 if (tx_win != tx_start) {
  91                         timeout = rtt;
  92                         tx_start = tx_win;
  93                 }
  94
  95                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  96                 timeout = schedule_timeout(timeout);
  97         }
  98 }
  99
 100 /*
 101  * Wait for space to appear in the Tx queue uninterruptibly.
 102  */
 103 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
 104                                             struct rxrpc_call *call,
 105                                             long *timeo)
 106 {
 107         for (;;) {
 108                 set_current_state(TASK_UNINTERRUPTIBLE);
 109                 if (rxrpc_check_tx_space(call, NULL))
 110                         return 0;
 111
 112                 if (call->state >= RXRPC_CALL_COMPLETE)
 113                         return call->error;
 114
 115                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
 116                 *timeo = schedule_timeout(*timeo);
 117         }
 118 }
 119
 120 /*
 121  * wait for space to appear in the transmit/ACK window
 122  * - caller holds the socket locked
 123  */
 124 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 125                                     struct rxrpc_call *call,
 126                                     long *timeo,
 127                                     bool waitall)
 128 {
 129         DECLARE_WAITQUEUE(myself, current);
 130         int ret;
 131
 132         _enter(",{%u,%u,%u}",
 133                call->tx_hard_ack, call->tx_top, call->tx_winsize);
 134
 135         add_wait_queue(&call->waitq, &myself);
 136
 137         switch (call->interruptibility) {
 138         case RXRPC_INTERRUPTIBLE:
 139                 if (waitall)
 140                         ret = rxrpc_wait_for_tx_window_waitall(rx, call);
 141                 else
 142                         ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 143                 break;
 144         case RXRPC_PREINTERRUPTIBLE:
 145         case RXRPC_UNINTERRUPTIBLE:
 146         default:
 147                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
 148                 break;
 149         }
 150
 151         remove_wait_queue(&call->waitq, &myself);
 152         set_current_state(TASK_RUNNING);
 153         _leave(" = %d", ret);
 154         return ret;
 155 }
 156
 157 /*
 158  * Schedule an instant Tx resend.
 159  */
 160 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
 161 {
 162         spin_lock_bh(&call->lock);
 163
 164         if (call->state < RXRPC_CALL_COMPLETE) {
 165                 call->rxtx_annotations[ix] =
 166                         (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
 167                         RXRPC_TX_ANNO_RETRANS;
 168                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
 169                         rxrpc_queue_call(call);
 170         }
 171
 172         spin_unlock_bh(&call->lock);
 173 }
 174
 175 /*
 176  * Notify the owner of the call that the transmit phase is ended and the last
 177  * packet has been queued.
 178  */
 179 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 180                                 rxrpc_notify_end_tx_t notify_end_tx)
 181 {
 182         if (notify_end_tx)
 183                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 184 }
 185
 186 /*
 187  * Queue a DATA packet for transmission, set the resend timeout and send
 188  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 189  * in case the caller wants to do something with it.
 190  */
 191 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 192                               struct sk_buff *skb, bool last,
 193                               rxrpc_notify_end_tx_t notify_end_tx)
 194 {
 195         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 196         unsigned long now;
 197         rxrpc_seq_t seq = sp->hdr.seq;
 198         int ret, ix;
 199         u8 annotation = RXRPC_TX_ANNO_UNACK;
 200
 201         _net("queue skb %p [%d]", skb, seq);
 202
 203         ASSERTCMP(seq, ==, call->tx_top + 1);
 204
 205         if (last)
 206                 annotation |= RXRPC_TX_ANNO_LAST;
 207
 208         /* We have to set the timestamp before queueing as the retransmit
 209          * algorithm can see the packet as soon as we queue it.
 210          */
 211         skb->tstamp = ktime_get_real();
 212
 213         ix = seq & RXRPC_RXTX_BUFF_MASK;
 214         rxrpc_get_skb(skb, rxrpc_skb_got);
 215         call->rxtx_annotations[ix] = annotation;
 216         smp_wmb();
 217         call->rxtx_buffer[ix] = skb;
 218         call->tx_top = seq;
 219         if (last)
 220                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 221         else
 222                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 223
 224         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 225                 _debug("________awaiting reply/ACK__________");
 226                 write_lock_bh(&call->state_lock);
 227                 switch (call->state) {
 228                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 229                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 230                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 231                         break;
 232                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 233                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 234                         now = jiffies;
 235                         WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
 236                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 237                                 call->ackr_reason = 0;
 238                         trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
 239                         if (!last)
 240                                 break;
 241                         fallthrough;
 242                 case RXRPC_CALL_SERVER_SEND_REPLY:
 243                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 244                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 245                         break;
 246                 default:
 247                         break;
 248                 }
 249                 write_unlock_bh(&call->state_lock);
 250         }
 251
 252         if (seq == 1 && rxrpc_is_client_call(call))
 253                 rxrpc_expose_client_call(call);
 254
 255         ret = rxrpc_send_data_packet(call, skb, false);
 256         if (ret < 0) {
 257                 switch (ret) {
 258                 case -ENETUNREACH:
 259                 case -EHOSTUNREACH:
 260                 case -ECONNREFUSED:
 261                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 262                                                   0, ret);
 263                         goto out;
 264                 }
 265                 _debug("need instant resend %d", ret);
 266                 rxrpc_instant_resend(call, ix);
 267         } else {
 268                 unsigned long now = jiffies;
 269                 unsigned long resend_at = now + call->peer->rto_j;
 270
 271                 WRITE_ONCE(call->resend_at, resend_at);
 272                 rxrpc_reduce_call_timer(call, resend_at, now,
 273                                         rxrpc_timer_set_for_send);
 274         }
 275
 276 out:
 277         rxrpc_free_skb(skb, rxrpc_skb_freed);
 278         _leave(" = %d", ret);
 279         return ret;
 280 }
 281
 282 /*
 283  * send data through a socket
 284  * - must be called in process context
 285  * - The caller holds the call user access mutex, but not the socket lock.
 286  */
 287 static int rxrpc_send_data(struct rxrpc_sock *rx,
 288                            struct rxrpc_call *call,
 289                            struct msghdr *msg, size_t len,
 290                            rxrpc_notify_end_tx_t notify_end_tx,
 291                            bool *_dropped_lock)
 292 {
 293         struct rxrpc_skb_priv *sp;
 294         struct sk_buff *skb;
 295         struct sock *sk = &rx->sk;
 296         enum rxrpc_call_state state;
 297         long timeo;
 298         bool more = msg->msg_flags & MSG_MORE;
 299         int ret, copied = 0;
 300
 301         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 302
 303         /* this should be in poll */
 304         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 305
 306 reload:
 307         ret = -EPIPE;
 308         if (sk->sk_shutdown & SEND_SHUTDOWN)
 309                 goto maybe_error;
 310         state = READ_ONCE(call->state);
 311         ret = -ESHUTDOWN;
 312         if (state >= RXRPC_CALL_COMPLETE)
 313                 goto maybe_error;
 314         ret = -EPROTO;
 315         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 316             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 317             state != RXRPC_CALL_SERVER_SEND_REPLY)
 318                 goto maybe_error;
 319
 320         ret = -EMSGSIZE;
 321         if (call->tx_total_len != -1) {
 322                 if (len - copied > call->tx_total_len)
 323                         goto maybe_error;
 324                 if (!more && len - copied != call->tx_total_len)
 325                         goto maybe_error;
 326         }
 327
 328         skb = call->tx_pending;
 329         call->tx_pending = NULL;
 330         rxrpc_see_skb(skb, rxrpc_skb_seen);
 331
 332         do {
 333                 /* Check to see if there's a ping ACK to reply to. */
 334                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 335                         rxrpc_send_ack_packet(call, false, NULL);
 336
 337                 if (!skb) {
 338                         size_t size, chunk, max, space;
 339
 340                         _debug("alloc");
 341
 342                         if (!rxrpc_check_tx_space(call, NULL))
 343                                 goto wait_for_space;
 344
 345                         max = RXRPC_JUMBO_DATALEN;
 346                         max -= call->conn->security_size;
 347                         max &= ~(call->conn->size_align - 1UL);
 348
 349                         chunk = max;
 350                         if (chunk > msg_data_left(msg) && !more)
 351                                 chunk = msg_data_left(msg);
 352
 353                         space = chunk + call->conn->size_align;
 354                         space &= ~(call->conn->size_align - 1UL);
 355
 356                         size = space + call->conn->security_size;
 357
 358                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 359
 360                         /* create a buffer that we can retain until it's ACK'd */
 361                         skb = sock_alloc_send_skb(
 362                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 363                         if (!skb)
 364                                 goto maybe_error;
 365
 366                         sp = rxrpc_skb(skb);
 367                         sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
 368                         rxrpc_new_skb(skb, rxrpc_skb_new);
 369
 370                         _debug("ALLOC SEND %p", skb);
 371
 372                         ASSERTCMP(skb->mark, ==, 0);
 373
 374                         _debug("HS: %u", call->conn->security_size);
 375                         skb_reserve(skb, call->conn->security_size);
 376                         skb->len += call->conn->security_size;
 377
 378                         sp->remain = chunk;
 379                         if (sp->remain > skb_tailroom(skb))
 380                                 sp->remain = skb_tailroom(skb);
 381
 382                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 383                                skb_headroom(skb),
 384                                skb_tailroom(skb),
 385                                skb_headlen(skb),
 386                                sp->remain);
 387
 388                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 389                 }
 390
 391                 _debug("append");
 392                 sp = rxrpc_skb(skb);
 393
 394                 /* append next segment of data to the current buffer */
 395                 if (msg_data_left(msg) > 0) {
 396                         int copy = skb_tailroom(skb);
 397                         ASSERTCMP(copy, >, 0);
 398                         if (copy > msg_data_left(msg))
 399                                 copy = msg_data_left(msg);
 400                         if (copy > sp->remain)
 401                                 copy = sp->remain;
 402
 403                         _debug("add");
 404                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 405                         _debug("added");
 406                         if (ret < 0)
 407                                 goto efault;
 408                         sp->remain -= copy;
 409                         skb->mark += copy;
 410                         copied += copy;
 411                         if (call->tx_total_len != -1)
 412                                 call->tx_total_len -= copy;
 413                 }
 414
 415                 /* check for the far side aborting the call or a network error
 416                  * occurring */
 417                 if (call->state == RXRPC_CALL_COMPLETE)
 418                         goto call_terminated;
 419
 420                 /* add the packet to the send queue if it's now full */
 421                 if (sp->remain <= 0 ||
 422                     (msg_data_left(msg) == 0 && !more)) {
 423                         struct rxrpc_connection *conn = call->conn;
 424                         uint32_t seq;
 425                         size_t pad;
 426
 427                         /* pad out if we're using security */
 428                         if (conn->security_ix) {
 429                                 pad = conn->security_size + skb->mark;
 430                                 pad = conn->size_align - pad;
 431                                 pad &= conn->size_align - 1;
 432                                 _debug("pad %zu", pad);
 433                                 if (pad)
 434                                         skb_put_zero(skb, pad);
 435                         }
 436
 437                         seq = call->tx_top + 1;
 438
 439                         sp->hdr.seq     = seq;
 440                         sp->hdr._rsvd   = 0;
 441                         sp->hdr.flags   = conn->out_clientflag;
 442
 443                         if (msg_data_left(msg) == 0 && !more)
 444                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 445                         else if (call->tx_top - call->tx_hard_ack <
 446                                  call->tx_winsize)
 447                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 448
 449                         ret = call->security->secure_packet(
 450                                 call, skb, skb->mark, skb->head);
 451                         if (ret < 0)
 452                                 goto out;
 453
 454                         ret = rxrpc_queue_packet(rx, call, skb,
 455                                                  !msg_data_left(msg) && !more,
 456                                                  notify_end_tx);
 457                         /* Should check for failure here */
 458                         skb = NULL;
 459                 }
 460         } while (msg_data_left(msg) > 0);
 461
 462 success:
 463         ret = copied;
 464         if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
 465                 read_lock_bh(&call->state_lock);
 466                 if (call->error < 0)
 467                         ret = call->error;
 468                 read_unlock_bh(&call->state_lock);
 469         }
 470 out:
 471         call->tx_pending = skb;
 472         _leave(" = %d", ret);
 473         return ret;
 474
 475 call_terminated:
 476         rxrpc_free_skb(skb, rxrpc_skb_freed);
 477         _leave(" = %d", call->error);
 478         return call->error;
 479
 480 maybe_error:
 481         if (copied)
 482                 goto success;
 483         goto out;
 484
 485 efault:
 486         ret = -EFAULT;
 487         goto out;
 488
 489 wait_for_space:
 490         ret = -EAGAIN;
 491         if (msg->msg_flags & MSG_DONTWAIT)
 492                 goto maybe_error;
 493         mutex_unlock(&call->user_mutex);
 494         *_dropped_lock = true;
 495         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
 496                                        msg->msg_flags & MSG_WAITALL);
 497         if (ret < 0)
 498                 goto maybe_error;
 499         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
 500                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 501                         ret = sock_intr_errno(timeo);
 502                         goto maybe_error;
 503                 }
 504         } else {
 505                 mutex_lock(&call->user_mutex);
 506         }
 507         *_dropped_lock = false;
 508         goto reload;
 509 }
 510
 511 /*
 512  * extract control messages from the sendmsg() control buffer
 513  */
 514 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 515 {
 516         struct cmsghdr *cmsg;
 517         bool got_user_ID = false;
 518         int len;
 519
 520         if (msg->msg_controllen == 0)
 521                 return -EINVAL;
 522
 523         for_each_cmsghdr(cmsg, msg) {
 524                 if (!CMSG_OK(msg, cmsg))
 525                         return -EINVAL;
 526
 527                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 528                 _debug("CMSG %d, %d, %d",
 529                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 530
 531                 if (cmsg->cmsg_level != SOL_RXRPC)
 532                         continue;
 533
 534                 switch (cmsg->cmsg_type) {
 535                 case RXRPC_USER_CALL_ID:
 536                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 537                                 if (len != sizeof(u32))
 538                                         return -EINVAL;
 539                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 540                         } else {
 541                                 if (len != sizeof(unsigned long))
 542                                         return -EINVAL;
 543                                 p->call.user_call_ID = *(unsigned long *)
 544                                         CMSG_DATA(cmsg);
 545                         }
 546                         got_user_ID = true;
 547                         break;
 548
 549                 case RXRPC_ABORT:
 550                         if (p->command != RXRPC_CMD_SEND_DATA)
 551                                 return -EINVAL;
 552                         p->command = RXRPC_CMD_SEND_ABORT;
 553                         if (len != sizeof(p->abort_code))
 554                                 return -EINVAL;
 555                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 556                         if (p->abort_code == 0)
 557                                 return -EINVAL;
 558                         break;
 559
 560                 case RXRPC_CHARGE_ACCEPT:
 561                         if (p->command != RXRPC_CMD_SEND_DATA)
 562                                 return -EINVAL;
 563                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
 564                         if (len != 0)
 565                                 return -EINVAL;
 566                         break;
 567
 568                 case RXRPC_EXCLUSIVE_CALL:
 569                         p->exclusive = true;
 570                         if (len != 0)
 571                                 return -EINVAL;
 572                         break;
 573
 574                 case RXRPC_UPGRADE_SERVICE:
 575                         p->upgrade = true;
 576                         if (len != 0)
 577                                 return -EINVAL;
 578                         break;
 579
 580                 case RXRPC_TX_LENGTH:
 581                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 582                                 return -EINVAL;
 583                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 584                         if (p->call.tx_total_len < 0)
 585                                 return -EINVAL;
 586                         break;
 587
 588                 case RXRPC_SET_CALL_TIMEOUT:
 589                         if (len & 3 || len < 4 || len > 12)
 590                                 return -EINVAL;
 591                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 592                         p->call.nr_timeouts = len / 4;
 593                         if (p->call.timeouts.hard > INT_MAX / HZ)
 594                                 return -ERANGE;
 595                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 596                                 return -ERANGE;
 597                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 598                                 return -ERANGE;
 599                         break;
 600
 601                 default:
 602                         return -EINVAL;
 603                 }
 604         }
 605
 606         if (!got_user_ID)
 607                 return -EINVAL;
 608         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 609                 return -EINVAL;
 610         _leave(" = 0");
 611         return 0;
 612 }
 613
 614 /*
 615  * Create a new client call for sendmsg().
 616  * - Called with the socket lock held, which it must release.
 617  * - If it returns a call, the call's lock will need releasing by the caller.
 618  */
 619 static struct rxrpc_call *
 620 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 621                                   struct rxrpc_send_params *p)
 622         __releases(&rx->sk.sk_lock.slock)
 623         __acquires(&call->user_mutex)
 624 {
 625         struct rxrpc_conn_parameters cp;
 626         struct rxrpc_call *call;
 627         struct key *key;
 628
 629         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 630
 631         _enter("");
 632
 633         if (!msg->msg_name) {
 634                 release_sock(&rx->sk);
 635                 return ERR_PTR(-EDESTADDRREQ);
 636         }
 637
 638         key = rx->key;
 639         if (key && !rx->key->payload.data[0])
 640                 key = NULL;
 641
 642         memset(&cp, 0, sizeof(cp));
 643         cp.local                = rx->local;
 644         cp.key                  = rx->key;
 645         cp.security_level       = rx->min_sec_level;
 646         cp.exclusive            = rx->exclusive | p->exclusive;
 647         cp.upgrade              = p->upgrade;
 648         cp.service_id           = srx->srx_service;
 649         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 650                                      atomic_inc_return(&rxrpc_debug_id));
 651         /* The socket is now unlocked */
 652
 653         rxrpc_put_peer(cp.peer);
 654         _leave(" = %p\n", call);
 655         return call;
 656 }
 657
 658 /*
 659  * send a message forming part of a client call through an RxRPC socket
 660  * - caller holds the socket locked
 661  * - the socket may be either a client socket or a server socket
 662  */
 663 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 664         __releases(&rx->sk.sk_lock.slock)
 665         __releases(&call->user_mutex)
 666 {
 667         enum rxrpc_call_state state;
 668         struct rxrpc_call *call;
 669         unsigned long now, j;
 670         bool dropped_lock = false;
 671         int ret;
 672
 673         struct rxrpc_send_params p = {
 674                 .call.tx_total_len      = -1,
 675                 .call.user_call_ID      = 0,
 676                 .call.nr_timeouts       = 0,
 677                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
 678                 .abort_code             = 0,
 679                 .command                = RXRPC_CMD_SEND_DATA,
 680                 .exclusive              = false,
 681                 .upgrade                = false,
 682         };
 683
 684         _enter("");
 685
 686         ret = rxrpc_sendmsg_cmsg(msg, &p);
 687         if (ret < 0)
 688                 goto error_release_sock;
 689
 690         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
 691                 ret = -EINVAL;
 692                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 693                         goto error_release_sock;
 694                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
 695                 goto error_release_sock;
 696         }
 697
 698         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 699         if (!call) {
 700                 ret = -EBADSLT;
 701                 if (p.command != RXRPC_CMD_SEND_DATA)
 702                         goto error_release_sock;
 703                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 704                 /* The socket is now unlocked... */
 705                 if (IS_ERR(call))
 706                         return PTR_ERR(call);
 707                 /* ... and we have the call lock. */
 708                 ret = 0;
 709                 if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
 710                         goto out_put_unlock;
 711         } else {
 712                 switch (READ_ONCE(call->state)) {
 713                 case RXRPC_CALL_UNINITIALISED:
 714                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 715                 case RXRPC_CALL_SERVER_PREALLOC:
 716                 case RXRPC_CALL_SERVER_SECURING:
 717                         rxrpc_put_call(call, rxrpc_call_put);
 718                         ret = -EBUSY;
 719                         goto error_release_sock;
 720                 default:
 721                         break;
 722                 }
 723
 724                 ret = mutex_lock_interruptible(&call->user_mutex);
 725                 release_sock(&rx->sk);
 726                 if (ret < 0) {
 727                         ret = -ERESTARTSYS;
 728                         goto error_put;
 729                 }
 730
 731                 if (p.call.tx_total_len != -1) {
 732                         ret = -EINVAL;
 733                         if (call->tx_total_len != -1 ||
 734                             call->tx_pending ||
 735                             call->tx_top != 0)
 736                                 goto out_put_unlock;
 737                         call->tx_total_len = p.call.tx_total_len;
 738                 }
 739         }
 740
 741         switch (p.call.nr_timeouts) {
 742         case 3:
 743                 j = msecs_to_jiffies(p.call.timeouts.normal);
 744                 if (p.call.timeouts.normal > 0 && j == 0)
 745                         j = 1;
 746                 WRITE_ONCE(call->next_rx_timo, j);
 747                 fallthrough;
 748         case 2:
 749                 j = msecs_to_jiffies(p.call.timeouts.idle);
 750                 if (p.call.timeouts.idle > 0 && j == 0)
 751                         j = 1;
 752                 WRITE_ONCE(call->next_req_timo, j);
 753                 fallthrough;
 754         case 1:
 755                 if (p.call.timeouts.hard > 0) {
 756                         j = p.call.timeouts.hard * HZ;
 757                         now = jiffies;
 758                         j += now;
 759                         WRITE_ONCE(call->expect_term_by, j);
 760                         rxrpc_reduce_call_timer(call, j, now,
 761                                                 rxrpc_timer_set_for_hard);
 762                 }
 763                 break;
 764         }
 765
 766         state = READ_ONCE(call->state);
 767         _debug("CALL %d USR %lx ST %d on CONN %p",
 768                call->debug_id, call->user_call_ID, state, call->conn);
 769
 770         if (state >= RXRPC_CALL_COMPLETE) {
 771                 /* it's too late for this call */
 772                 ret = -ESHUTDOWN;
 773         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 774                 ret = 0;
 775                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 776                         ret = rxrpc_send_abort_packet(call);
 777         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 778                 ret = -EINVAL;
 779         } else {
 780                 ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
 781         }
 782
 783 out_put_unlock:
 784         if (!dropped_lock)
 785                 mutex_unlock(&call->user_mutex);
 786 error_put:
 787         rxrpc_put_call(call, rxrpc_call_put);
 788         _leave(" = %d", ret);
 789         return ret;
 790
 791 error_release_sock:
 792         release_sock(&rx->sk);
 793         return ret;
 794 }
 795
 796 /**
 797  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 798  * @sock: The socket the call is on
 799  * @call: The call to send data through
 800  * @msg: The data to send
 801  * @len: The amount of data to send
 802  * @notify_end_tx: Notification that the last packet is queued.
 803  *
 804  * Allow a kernel service to send data on a call.  The call must be in an state
 805  * appropriate to sending data.  No control data should be supplied in @msg,
 806  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 807  * more data to come, otherwise this data will end the transmission phase.
 808  */
 809 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 810                            struct msghdr *msg, size_t len,
 811                            rxrpc_notify_end_tx_t notify_end_tx)
 812 {
 813         bool dropped_lock = false;
 814         int ret;
 815
 816         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 817
 818         ASSERTCMP(msg->msg_name, ==, NULL);
 819         ASSERTCMP(msg->msg_control, ==, NULL);
 820
 821         mutex_lock(&call->user_mutex);
 822
 823         _debug("CALL %d USR %lx ST %d on CONN %p",
 824                call->debug_id, call->user_call_ID, call->state, call->conn);
 825
 826         switch (READ_ONCE(call->state)) {
 827         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 828         case RXRPC_CALL_SERVER_ACK_REQUEST:
 829         case RXRPC_CALL_SERVER_SEND_REPLY:
 830                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 831                                       notify_end_tx, &dropped_lock);
 832                 break;
 833         case RXRPC_CALL_COMPLETE:
 834                 read_lock_bh(&call->state_lock);
 835                 ret = call->error;
 836                 read_unlock_bh(&call->state_lock);
 837                 break;
 838         default:
 839                 /* Request phase complete for this client call */
 840                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 841                 ret = -EPROTO;
 842                 break;
 843         }
 844
 845         if (!dropped_lock)
 846                 mutex_unlock(&call->user_mutex);
 847         _leave(" = %d", ret);
 848         return ret;
 849 }
 850 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 851
 852 /**
 853  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 854  * @sock: The socket the call is on
 855  * @call: The call to be aborted
 856  * @abort_code: The abort code to stick into the ABORT packet
 857  * @error: Local error value
 858  * @why: 3-char string indicating why.
 859  *
 860  * Allow a kernel service to abort a call, if it's still in an abortable state
 861  * and return true if the call was aborted, false if it was already complete.
 862  */
 863 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 864                              u32 abort_code, int error, const char *why)
 865 {
 866         bool aborted;
 867
 868         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 869
 870         mutex_lock(&call->user_mutex);
 871
 872         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 873         if (aborted)
 874                 rxrpc_send_abort_packet(call);
 875
 876         mutex_unlock(&call->user_mutex);
 877         return aborted;
 878 }
 879 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 880
 881 /**
 882  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 883  * @sock: The socket the call is on
 884  * @call: The call to be informed
 885  * @tx_total_len: The amount of data to be transmitted for this call
 886  *
 887  * Allow a kernel service to set the total transmit length on a call.  This
 888  * allows buffer-to-packet encrypt-and-copy to be performed.
 889  *
 890  * This function is primarily for use for setting the reply length since the
 891  * request length can be set when beginning the call.
 892  */
 893 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 894                                 s64 tx_total_len)
 895 {
 896         WARN_ON(call->tx_total_len != -1);
 897         call->tx_total_len = tx_total_len;
 898 }
 899 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);