net/rxrpc/sendmsg.c

   1 /* AF_RXRPC sendmsg() implementation.
   2  *
   3  * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/net.h>
  15 #include <linux/gfp.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/export.h>
  18 #include <linux/sched/signal.h>
  19
  20 #include <net/sock.h>
  21 #include <net/af_rxrpc.h>
  22 #include "ar-internal.h"
  23
  24 /*
  25  * Wait for space to appear in the Tx queue or a signal to occur.
  26  */
  27 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
  28                                          struct rxrpc_call *call,
  29                                          long *timeo)
  30 {
  31         for (;;) {
  32                 set_current_state(TASK_INTERRUPTIBLE);
  33                 if (call->tx_top - call->tx_hard_ack <
  34                     min_t(unsigned int, call->tx_winsize,
  35                           call->cong_cwnd + call->cong_extra))
  36                         return 0;
  37
  38                 if (call->state >= RXRPC_CALL_COMPLETE)
  39                         return call->error;
  40
  41                 if (signal_pending(current))
  42                         return sock_intr_errno(*timeo);
  43
  44                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  45                 mutex_unlock(&call->user_mutex);
  46                 *timeo = schedule_timeout(*timeo);
  47                 if (mutex_lock_interruptible(&call->user_mutex) < 0)
  48                         return sock_intr_errno(*timeo);
  49         }
  50 }
  51
  52 /*
  53  * Wait for space to appear in the Tx queue uninterruptibly, but with
  54  * a timeout of 2*RTT if no progress was made and a signal occurred.
  55  */
  56 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
  57                                             struct rxrpc_call *call)
  58 {
  59         rxrpc_seq_t tx_start, tx_win;
  60         signed long rtt2, timeout;
  61         u64 rtt;
  62
  63         rtt = READ_ONCE(call->peer->rtt);
  64         rtt2 = nsecs_to_jiffies64(rtt) * 2;
  65         if (rtt2 < 2)
  66                 rtt2 = 2;
  67
  68         timeout = rtt2;
  69         tx_start = READ_ONCE(call->tx_hard_ack);
  70
  71         for (;;) {
  72                 set_current_state(TASK_UNINTERRUPTIBLE);
  73
  74                 tx_win = READ_ONCE(call->tx_hard_ack);
  75                 if (call->tx_top - tx_win <
  76                     min_t(unsigned int, call->tx_winsize,
  77                           call->cong_cwnd + call->cong_extra))
  78                         return 0;
  79
  80                 if (call->state >= RXRPC_CALL_COMPLETE)
  81                         return call->error;
  82
  83                 if (timeout == 0 &&
  84                     tx_win == tx_start && signal_pending(current))
  85                         return -EINTR;
  86
  87                 if (tx_win != tx_start) {
  88                         timeout = rtt2;
  89                         tx_start = tx_win;
  90                 }
  91
  92                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  93                 timeout = schedule_timeout(timeout);
  94         }
  95 }
  96
  97 /*
  98  * wait for space to appear in the transmit/ACK window
  99  * - caller holds the socket locked
 100  */
 101 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 102                                     struct rxrpc_call *call,
 103                                     long *timeo,
 104                                     bool waitall)
 105 {
 106         DECLARE_WAITQUEUE(myself, current);
 107         int ret;
 108
 109         _enter(",{%u,%u,%u}",
 110                call->tx_hard_ack, call->tx_top, call->tx_winsize);
 111
 112         add_wait_queue(&call->waitq, &myself);
 113
 114         if (waitall)
 115                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
 116         else
 117                 ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 118
 119         remove_wait_queue(&call->waitq, &myself);
 120         set_current_state(TASK_RUNNING);
 121         _leave(" = %d", ret);
 122         return ret;
 123 }
 124
 125 /*
 126  * Schedule an instant Tx resend.
 127  */
 128 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
 129 {
 130         spin_lock_bh(&call->lock);
 131
 132         if (call->state < RXRPC_CALL_COMPLETE) {
 133                 call->rxtx_annotations[ix] =
 134                         (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
 135                         RXRPC_TX_ANNO_RETRANS;
 136                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
 137                         rxrpc_queue_call(call);
 138         }
 139
 140         spin_unlock_bh(&call->lock);
 141 }
 142
 143 /*
 144  * Notify the owner of the call that the transmit phase is ended and the last
 145  * packet has been queued.
 146  */
 147 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 148                                 rxrpc_notify_end_tx_t notify_end_tx)
 149 {
 150         if (notify_end_tx)
 151                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 152 }
 153
 154 /*
 155  * Queue a DATA packet for transmission, set the resend timeout and send the
 156  * packet immediately
 157  */
 158 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 159                                struct sk_buff *skb, bool last,
 160                                rxrpc_notify_end_tx_t notify_end_tx)
 161 {
 162         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 163         unsigned long now;
 164         rxrpc_seq_t seq = sp->hdr.seq;
 165         int ret, ix;
 166         u8 annotation = RXRPC_TX_ANNO_UNACK;
 167
 168         _net("queue skb %p [%d]", skb, seq);
 169
 170         ASSERTCMP(seq, ==, call->tx_top + 1);
 171
 172         if (last) {
 173                 annotation |= RXRPC_TX_ANNO_LAST;
 174                 set_bit(RXRPC_CALL_TX_LASTQ, &call->flags);
 175         }
 176
 177         /* We have to set the timestamp before queueing as the retransmit
 178          * algorithm can see the packet as soon as we queue it.
 179          */
 180         skb->tstamp = ktime_get_real();
 181
 182         ix = seq & RXRPC_RXTX_BUFF_MASK;
 183         rxrpc_get_skb(skb, rxrpc_skb_tx_got);
 184         call->rxtx_annotations[ix] = annotation;
 185         smp_wmb();
 186         call->rxtx_buffer[ix] = skb;
 187         call->tx_top = seq;
 188         if (last)
 189                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 190         else
 191                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 192
 193         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 194                 _debug("________awaiting reply/ACK__________");
 195                 write_lock_bh(&call->state_lock);
 196                 switch (call->state) {
 197                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 198                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 199                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 200                         break;
 201                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 202                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 203                         now = jiffies;
 204                         WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
 205                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 206                                 call->ackr_reason = 0;
 207                         trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
 208                         if (!last)
 209                                 break;
 210                         /* Fall through */
 211                 case RXRPC_CALL_SERVER_SEND_REPLY:
 212                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 213                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 214                         break;
 215                 default:
 216                         break;
 217                 }
 218                 write_unlock_bh(&call->state_lock);
 219         }
 220
 221         if (seq == 1 && rxrpc_is_client_call(call))
 222                 rxrpc_expose_client_call(call);
 223
 224         ret = rxrpc_send_data_packet(call, skb, false);
 225         if (ret < 0) {
 226                 switch (ret) {
 227                 case -ENETUNREACH:
 228                 case -EHOSTUNREACH:
 229                 case -ECONNREFUSED:
 230                         rxrpc_set_call_completion(call,
 231                                                   RXRPC_CALL_LOCAL_ERROR,
 232                                                   0, ret);
 233                         rxrpc_notify_socket(call);
 234                         goto out;
 235                 }
 236                 _debug("need instant resend %d", ret);
 237                 rxrpc_instant_resend(call, ix);
 238         } else {
 239                 unsigned long now = jiffies, resend_at;
 240
 241                 if (call->peer->rtt_usage > 1)
 242                         resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
 243                 else
 244                         resend_at = rxrpc_resend_timeout;
 245                 if (resend_at < 1)
 246                         resend_at = 1;
 247
 248                 resend_at += now;
 249                 WRITE_ONCE(call->resend_at, resend_at);
 250                 rxrpc_reduce_call_timer(call, resend_at, now,
 251                                         rxrpc_timer_set_for_send);
 252         }
 253
 254 out:
 255         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 256         _leave("");
 257 }
 258
 259 /*
 260  * send data through a socket
 261  * - must be called in process context
 262  * - The caller holds the call user access mutex, but not the socket lock.
 263  */
 264 static int rxrpc_send_data(struct rxrpc_sock *rx,
 265                            struct rxrpc_call *call,
 266                            struct msghdr *msg, size_t len,
 267                            rxrpc_notify_end_tx_t notify_end_tx)
 268 {
 269         struct rxrpc_skb_priv *sp;
 270         struct sk_buff *skb;
 271         struct sock *sk = &rx->sk;
 272         long timeo;
 273         bool more;
 274         int ret, copied;
 275
 276         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 277
 278         /* this should be in poll */
 279         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 280
 281         if (sk->sk_shutdown & SEND_SHUTDOWN)
 282                 return -EPIPE;
 283
 284         more = msg->msg_flags & MSG_MORE;
 285
 286         if (call->tx_total_len != -1) {
 287                 if (len > call->tx_total_len)
 288                         return -EMSGSIZE;
 289                 if (!more && len != call->tx_total_len)
 290                         return -EMSGSIZE;
 291         }
 292
 293         skb = call->tx_pending;
 294         call->tx_pending = NULL;
 295         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 296
 297         copied = 0;
 298         do {
 299                 /* Check to see if there's a ping ACK to reply to. */
 300                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 301                         rxrpc_send_ack_packet(call, false, NULL);
 302
 303                 if (!skb) {
 304                         size_t size, chunk, max, space;
 305
 306                         _debug("alloc");
 307
 308                         if (call->tx_top - call->tx_hard_ack >=
 309                             min_t(unsigned int, call->tx_winsize,
 310                                   call->cong_cwnd + call->cong_extra)) {
 311                                 ret = -EAGAIN;
 312                                 if (msg->msg_flags & MSG_DONTWAIT)
 313                                         goto maybe_error;
 314                                 ret = rxrpc_wait_for_tx_window(rx, call,
 315                                                                &timeo,
 316                                                                msg->msg_flags & MSG_WAITALL);
 317                                 if (ret < 0)
 318                                         goto maybe_error;
 319                         }
 320
 321                         max = RXRPC_JUMBO_DATALEN;
 322                         max -= call->conn->security_size;
 323                         max &= ~(call->conn->size_align - 1UL);
 324
 325                         chunk = max;
 326                         if (chunk > msg_data_left(msg) && !more)
 327                                 chunk = msg_data_left(msg);
 328
 329                         space = chunk + call->conn->size_align;
 330                         space &= ~(call->conn->size_align - 1UL);
 331
 332                         size = space + call->conn->security_size;
 333
 334                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 335
 336                         /* create a buffer that we can retain until it's ACK'd */
 337                         skb = sock_alloc_send_skb(
 338                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 339                         if (!skb)
 340                                 goto maybe_error;
 341
 342                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 343
 344                         _debug("ALLOC SEND %p", skb);
 345
 346                         ASSERTCMP(skb->mark, ==, 0);
 347
 348                         _debug("HS: %u", call->conn->security_size);
 349                         skb_reserve(skb, call->conn->security_size);
 350                         skb->len += call->conn->security_size;
 351
 352                         sp = rxrpc_skb(skb);
 353                         sp->remain = chunk;
 354                         if (sp->remain > skb_tailroom(skb))
 355                                 sp->remain = skb_tailroom(skb);
 356
 357                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 358                                skb_headroom(skb),
 359                                skb_tailroom(skb),
 360                                skb_headlen(skb),
 361                                sp->remain);
 362
 363                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 364                 }
 365
 366                 _debug("append");
 367                 sp = rxrpc_skb(skb);
 368
 369                 /* append next segment of data to the current buffer */
 370                 if (msg_data_left(msg) > 0) {
 371                         int copy = skb_tailroom(skb);
 372                         ASSERTCMP(copy, >, 0);
 373                         if (copy > msg_data_left(msg))
 374                                 copy = msg_data_left(msg);
 375                         if (copy > sp->remain)
 376                                 copy = sp->remain;
 377
 378                         _debug("add");
 379                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 380                         _debug("added");
 381                         if (ret < 0)
 382                                 goto efault;
 383                         sp->remain -= copy;
 384                         skb->mark += copy;
 385                         copied += copy;
 386                         if (call->tx_total_len != -1)
 387                                 call->tx_total_len -= copy;
 388                 }
 389
 390                 /* add the packet to the send queue if it's now full */
 391                 if (sp->remain <= 0 ||
 392                     (msg_data_left(msg) == 0 && !more)) {
 393                         struct rxrpc_connection *conn = call->conn;
 394                         uint32_t seq;
 395                         size_t pad;
 396
 397                         /* pad out if we're using security */
 398                         if (conn->security_ix) {
 399                                 pad = conn->security_size + skb->mark;
 400                                 pad = conn->size_align - pad;
 401                                 pad &= conn->size_align - 1;
 402                                 _debug("pad %zu", pad);
 403                                 if (pad)
 404                                         skb_put_zero(skb, pad);
 405                         }
 406
 407                         seq = call->tx_top + 1;
 408
 409                         sp->hdr.seq     = seq;
 410                         sp->hdr._rsvd   = 0;
 411                         sp->hdr.flags   = conn->out_clientflag;
 412
 413                         if (msg_data_left(msg) == 0 && !more)
 414                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 415                         else if (call->tx_top - call->tx_hard_ack <
 416                                  call->tx_winsize)
 417                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 418
 419                         ret = conn->security->secure_packet(
 420                                 call, skb, skb->mark, skb->head);
 421                         if (ret < 0)
 422                                 goto out;
 423
 424                         rxrpc_queue_packet(rx, call, skb,
 425                                            !msg_data_left(msg) && !more,
 426                                            notify_end_tx);
 427                         skb = NULL;
 428                 }
 429
 430                 /* Check for the far side aborting the call or a network error
 431                  * occurring.  If this happens, save any packet that was under
 432                  * construction so that in the case of a network error, the
 433                  * call can be retried or redirected.
 434                  */
 435                 if (call->state == RXRPC_CALL_COMPLETE) {
 436                         ret = call->error;
 437                         goto out;
 438                 }
 439         } while (msg_data_left(msg) > 0);
 440
 441 success:
 442         ret = copied;
 443 out:
 444         call->tx_pending = skb;
 445         _leave(" = %d", ret);
 446         return ret;
 447
 448 maybe_error:
 449         if (copied)
 450                 goto success;
 451         goto out;
 452
 453 efault:
 454         ret = -EFAULT;
 455         goto out;
 456 }
 457
 458 /*
 459  * extract control messages from the sendmsg() control buffer
 460  */
 461 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 462 {
 463         struct cmsghdr *cmsg;
 464         bool got_user_ID = false;
 465         int len;
 466
 467         if (msg->msg_controllen == 0)
 468                 return -EINVAL;
 469
 470         for_each_cmsghdr(cmsg, msg) {
 471                 if (!CMSG_OK(msg, cmsg))
 472                         return -EINVAL;
 473
 474                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 475                 _debug("CMSG %d, %d, %d",
 476                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 477
 478                 if (cmsg->cmsg_level != SOL_RXRPC)
 479                         continue;
 480
 481                 switch (cmsg->cmsg_type) {
 482                 case RXRPC_USER_CALL_ID:
 483                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 484                                 if (len != sizeof(u32))
 485                                         return -EINVAL;
 486                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 487                         } else {
 488                                 if (len != sizeof(unsigned long))
 489                                         return -EINVAL;
 490                                 p->call.user_call_ID = *(unsigned long *)
 491                                         CMSG_DATA(cmsg);
 492                         }
 493                         got_user_ID = true;
 494                         break;
 495
 496                 case RXRPC_ABORT:
 497                         if (p->command != RXRPC_CMD_SEND_DATA)
 498                                 return -EINVAL;
 499                         p->command = RXRPC_CMD_SEND_ABORT;
 500                         if (len != sizeof(p->abort_code))
 501                                 return -EINVAL;
 502                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 503                         if (p->abort_code == 0)
 504                                 return -EINVAL;
 505                         break;
 506
 507                 case RXRPC_ACCEPT:
 508                         if (p->command != RXRPC_CMD_SEND_DATA)
 509                                 return -EINVAL;
 510                         p->command = RXRPC_CMD_ACCEPT;
 511                         if (len != 0)
 512                                 return -EINVAL;
 513                         break;
 514
 515                 case RXRPC_EXCLUSIVE_CALL:
 516                         p->exclusive = true;
 517                         if (len != 0)
 518                                 return -EINVAL;
 519                         break;
 520
 521                 case RXRPC_UPGRADE_SERVICE:
 522                         p->upgrade = true;
 523                         if (len != 0)
 524                                 return -EINVAL;
 525                         break;
 526
 527                 case RXRPC_TX_LENGTH:
 528                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 529                                 return -EINVAL;
 530                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 531                         if (p->call.tx_total_len < 0)
 532                                 return -EINVAL;
 533                         break;
 534
 535                 case RXRPC_SET_CALL_TIMEOUT:
 536                         if (len & 3 || len < 4 || len > 12)
 537                                 return -EINVAL;
 538                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 539                         p->call.nr_timeouts = len / 4;
 540                         if (p->call.timeouts.hard > INT_MAX / HZ)
 541                                 return -ERANGE;
 542                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 543                                 return -ERANGE;
 544                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 545                                 return -ERANGE;
 546                         break;
 547
 548                 default:
 549                         return -EINVAL;
 550                 }
 551         }
 552
 553         if (!got_user_ID)
 554                 return -EINVAL;
 555         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 556                 return -EINVAL;
 557         _leave(" = 0");
 558         return 0;
 559 }
 560
 561 /*
 562  * Create a new client call for sendmsg().
 563  * - Called with the socket lock held, which it must release.
 564  * - If it returns a call, the call's lock will need releasing by the caller.
 565  */
 566 static struct rxrpc_call *
 567 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 568                                   struct rxrpc_send_params *p)
 569         __releases(&rx->sk.sk_lock.slock)
 570         __acquires(&call->user_mutex)
 571 {
 572         struct rxrpc_conn_parameters cp;
 573         struct rxrpc_call *call;
 574         struct key *key;
 575
 576         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 577
 578         _enter("");
 579
 580         if (!msg->msg_name) {
 581                 release_sock(&rx->sk);
 582                 return ERR_PTR(-EDESTADDRREQ);
 583         }
 584
 585         key = rx->key;
 586         if (key && !rx->key->payload.data[0])
 587                 key = NULL;
 588
 589         memset(&cp, 0, sizeof(cp));
 590         cp.local                = rx->local;
 591         cp.key                  = rx->key;
 592         cp.security_level       = rx->min_sec_level;
 593         cp.exclusive            = rx->exclusive | p->exclusive;
 594         cp.upgrade              = p->upgrade;
 595         cp.service_id           = srx->srx_service;
 596         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 597                                      atomic_inc_return(&rxrpc_debug_id));
 598         /* The socket is now unlocked */
 599
 600         rxrpc_put_peer(cp.peer);
 601         _leave(" = %p\n", call);
 602         return call;
 603 }
 604
 605 /*
 606  * send a message forming part of a client call through an RxRPC socket
 607  * - caller holds the socket locked
 608  * - the socket may be either a client socket or a server socket
 609  */
 610 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 611         __releases(&rx->sk.sk_lock.slock)
 612         __releases(&call->user_mutex)
 613 {
 614         enum rxrpc_call_state state;
 615         struct rxrpc_call *call;
 616         unsigned long now, j;
 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                 .abort_code             = 0,
 624                 .command                = RXRPC_CMD_SEND_DATA,
 625                 .exclusive              = false,
 626                 .upgrade                = false,
 627         };
 628
 629         _enter("");
 630
 631         ret = rxrpc_sendmsg_cmsg(msg, &p);
 632         if (ret < 0)
 633                 goto error_release_sock;
 634
 635         if (p.command == RXRPC_CMD_ACCEPT) {
 636                 ret = -EINVAL;
 637                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 638                         goto error_release_sock;
 639                 call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
 640                 /* The socket is now unlocked. */
 641                 if (IS_ERR(call))
 642                         return PTR_ERR(call);
 643                 ret = 0;
 644                 goto out_put_unlock;
 645         }
 646
 647         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 648         if (!call) {
 649                 ret = -EBADSLT;
 650                 if (p.command != RXRPC_CMD_SEND_DATA)
 651                         goto error_release_sock;
 652                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 653                 /* The socket is now unlocked... */
 654                 if (IS_ERR(call))
 655                         return PTR_ERR(call);
 656                 /* ... and we have the call lock. */
 657                 ret = 0;
 658                 if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
 659                         goto out_put_unlock;
 660         } else {
 661                 switch (READ_ONCE(call->state)) {
 662                 case RXRPC_CALL_UNINITIALISED:
 663                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 664                 case RXRPC_CALL_SERVER_PREALLOC:
 665                 case RXRPC_CALL_SERVER_SECURING:
 666                 case RXRPC_CALL_SERVER_ACCEPTING:
 667                         rxrpc_put_call(call, rxrpc_call_put);
 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 error_put;
 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                 /* Fall through */
 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                 /* Fall through */
 704         case 1:
 705                 if (p.call.timeouts.hard > 0) {
 706                         j = msecs_to_jiffies(p.call.timeouts.hard);
 707                         now = jiffies;
 708                         j += now;
 709                         WRITE_ONCE(call->expect_term_by, j);
 710                         rxrpc_reduce_call_timer(call, j, now,
 711                                                 rxrpc_timer_set_for_hard);
 712                 }
 713                 break;
 714         }
 715
 716         state = READ_ONCE(call->state);
 717         _debug("CALL %d USR %lx ST %d on CONN %p",
 718                call->debug_id, call->user_call_ID, state, call->conn);
 719
 720         if (state >= RXRPC_CALL_COMPLETE) {
 721                 /* it's too late for this call */
 722                 ret = -ESHUTDOWN;
 723         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 724                 ret = 0;
 725                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 726                         ret = rxrpc_send_abort_packet(call);
 727         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 728                 ret = -EINVAL;
 729         } else if (rxrpc_is_client_call(call) &&
 730                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 731                 /* request phase complete for this client call */
 732                 ret = -EPROTO;
 733         } else if (rxrpc_is_service_call(call) &&
 734                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 735                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 736                 /* Reply phase not begun or not complete for service call. */
 737                 ret = -EPROTO;
 738         } else {
 739                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 740         }
 741
 742 out_put_unlock:
 743         mutex_unlock(&call->user_mutex);
 744 error_put:
 745         rxrpc_put_call(call, rxrpc_call_put);
 746         _leave(" = %d", ret);
 747         return ret;
 748
 749 error_release_sock:
 750         release_sock(&rx->sk);
 751         return ret;
 752 }
 753
 754 /**
 755  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 756  * @sock: The socket the call is on
 757  * @call: The call to send data through
 758  * @msg: The data to send
 759  * @len: The amount of data to send
 760  * @notify_end_tx: Notification that the last packet is queued.
 761  *
 762  * Allow a kernel service to send data on a call.  The call must be in an state
 763  * appropriate to sending data.  No control data should be supplied in @msg,
 764  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 765  * more data to come, otherwise this data will end the transmission phase.
 766  */
 767 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 768                            struct msghdr *msg, size_t len,
 769                            rxrpc_notify_end_tx_t notify_end_tx)
 770 {
 771         int ret;
 772
 773         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 774
 775         ASSERTCMP(msg->msg_name, ==, NULL);
 776         ASSERTCMP(msg->msg_control, ==, NULL);
 777
 778         mutex_lock(&call->user_mutex);
 779
 780         _debug("CALL %d USR %lx ST %d on CONN %p",
 781                call->debug_id, call->user_call_ID, call->state, call->conn);
 782
 783         switch (READ_ONCE(call->state)) {
 784         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 785         case RXRPC_CALL_SERVER_ACK_REQUEST:
 786         case RXRPC_CALL_SERVER_SEND_REPLY:
 787                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 788                                       notify_end_tx);
 789                 break;
 790         case RXRPC_CALL_COMPLETE:
 791                 read_lock_bh(&call->state_lock);
 792                 ret = call->error;
 793                 read_unlock_bh(&call->state_lock);
 794                 break;
 795         default:
 796                 /* Request phase complete for this client call */
 797                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 798                 ret = -EPROTO;
 799                 break;
 800         }
 801
 802         mutex_unlock(&call->user_mutex);
 803         _leave(" = %d", ret);
 804         return ret;
 805 }
 806 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 807
 808 /**
 809  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 810  * @sock: The socket the call is on
 811  * @call: The call to be aborted
 812  * @abort_code: The abort code to stick into the ABORT packet
 813  * @error: Local error value
 814  * @why: 3-char string indicating why.
 815  *
 816  * Allow a kernel service to abort a call, if it's still in an abortable state
 817  * and return true if the call was aborted, false if it was already complete.
 818  */
 819 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 820                              u32 abort_code, int error, const char *why)
 821 {
 822         bool aborted;
 823
 824         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 825
 826         mutex_lock(&call->user_mutex);
 827
 828         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 829         if (aborted)
 830                 rxrpc_send_abort_packet(call);
 831
 832         mutex_unlock(&call->user_mutex);
 833         return aborted;
 834 }
 835 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 836
 837 /**
 838  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 839  * @sock: The socket the call is on
 840  * @call: The call to be informed
 841  * @tx_total_len: The amount of data to be transmitted for this call
 842  *
 843  * Allow a kernel service to set the total transmit length on a call.  This
 844  * allows buffer-to-packet encrypt-and-copy to be performed.
 845  *
 846  * This function is primarily for use for setting the reply length since the
 847  * request length can be set when beginning the call.
 848  */
 849 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 850                                 s64 tx_total_len)
 851 {
 852         WARN_ON(call->tx_total_len != -1);
 853         call->tx_total_len = tx_total_len;
 854 }
 855 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);