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 < 1)
  66                 rtt2 = 1;
  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                         goto out;
 234                 }
 235                 _debug("need instant resend %d", ret);
 236                 rxrpc_instant_resend(call, ix);
 237         } else {
 238                 unsigned long now = jiffies, resend_at;
 239
 240                 if (call->peer->rtt_usage > 1)
 241                         resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
 242                 else
 243                         resend_at = rxrpc_resend_timeout;
 244                 if (resend_at < 1)
 245                         resend_at = 1;
 246
 247                 resend_at += now;
 248                 WRITE_ONCE(call->resend_at, resend_at);
 249                 rxrpc_reduce_call_timer(call, resend_at, now,
 250                                         rxrpc_timer_set_for_send);
 251         }
 252
 253 out:
 254         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 255         _leave("");
 256 }
 257
 258 /*
 259  * send data through a socket
 260  * - must be called in process context
 261  * - The caller holds the call user access mutex, but not the socket lock.
 262  */
 263 static int rxrpc_send_data(struct rxrpc_sock *rx,
 264                            struct rxrpc_call *call,
 265                            struct msghdr *msg, size_t len,
 266                            rxrpc_notify_end_tx_t notify_end_tx)
 267 {
 268         struct rxrpc_skb_priv *sp;
 269         struct sk_buff *skb;
 270         struct sock *sk = &rx->sk;
 271         long timeo;
 272         bool more;
 273         int ret, copied;
 274
 275         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 276
 277         /* this should be in poll */
 278         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 279
 280         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 281                 return -EPIPE;
 282
 283         more = msg->msg_flags & MSG_MORE;
 284
 285         if (call->tx_total_len != -1) {
 286                 if (len > call->tx_total_len)
 287                         return -EMSGSIZE;
 288                 if (!more && len != call->tx_total_len)
 289                         return -EMSGSIZE;
 290         }
 291
 292         skb = call->tx_pending;
 293         call->tx_pending = NULL;
 294         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 295
 296         copied = 0;
 297         do {
 298                 /* Check to see if there's a ping ACK to reply to. */
 299                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 300                         rxrpc_send_ack_packet(call, false, NULL);
 301
 302                 if (!skb) {
 303                         size_t size, chunk, max, space;
 304
 305                         _debug("alloc");
 306
 307                         if (call->tx_top - call->tx_hard_ack >=
 308                             min_t(unsigned int, call->tx_winsize,
 309                                   call->cong_cwnd + call->cong_extra)) {
 310                                 ret = -EAGAIN;
 311                                 if (msg->msg_flags & MSG_DONTWAIT)
 312                                         goto maybe_error;
 313                                 ret = rxrpc_wait_for_tx_window(rx, call,
 314                                                                &timeo,
 315                                                                msg->msg_flags & MSG_WAITALL);
 316                                 if (ret < 0)
 317                                         goto maybe_error;
 318                         }
 319
 320                         max = RXRPC_JUMBO_DATALEN;
 321                         max -= call->conn->security_size;
 322                         max &= ~(call->conn->size_align - 1UL);
 323
 324                         chunk = max;
 325                         if (chunk > msg_data_left(msg) && !more)
 326                                 chunk = msg_data_left(msg);
 327
 328                         space = chunk + call->conn->size_align;
 329                         space &= ~(call->conn->size_align - 1UL);
 330
 331                         size = space + call->conn->security_size;
 332
 333                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 334
 335                         /* create a buffer that we can retain until it's ACK'd */
 336                         skb = sock_alloc_send_skb(
 337                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 338                         if (!skb)
 339                                 goto maybe_error;
 340
 341                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 342
 343                         _debug("ALLOC SEND %p", skb);
 344
 345                         ASSERTCMP(skb->mark, ==, 0);
 346
 347                         _debug("HS: %u", call->conn->security_size);
 348                         skb_reserve(skb, call->conn->security_size);
 349                         skb->len += call->conn->security_size;
 350
 351                         sp = rxrpc_skb(skb);
 352                         sp->remain = chunk;
 353                         if (sp->remain > skb_tailroom(skb))
 354                                 sp->remain = skb_tailroom(skb);
 355
 356                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 357                                skb_headroom(skb),
 358                                skb_tailroom(skb),
 359                                skb_headlen(skb),
 360                                sp->remain);
 361
 362                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 363                 }
 364
 365                 _debug("append");
 366                 sp = rxrpc_skb(skb);
 367
 368                 /* append next segment of data to the current buffer */
 369                 if (msg_data_left(msg) > 0) {
 370                         int copy = skb_tailroom(skb);
 371                         ASSERTCMP(copy, >, 0);
 372                         if (copy > msg_data_left(msg))
 373                                 copy = msg_data_left(msg);
 374                         if (copy > sp->remain)
 375                                 copy = sp->remain;
 376
 377                         _debug("add");
 378                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 379                         _debug("added");
 380                         if (ret < 0)
 381                                 goto efault;
 382                         sp->remain -= copy;
 383                         skb->mark += copy;
 384                         copied += copy;
 385                         if (call->tx_total_len != -1)
 386                                 call->tx_total_len -= copy;
 387                 }
 388
 389                 /* add the packet to the send queue if it's now full */
 390                 if (sp->remain <= 0 ||
 391                     (msg_data_left(msg) == 0 && !more)) {
 392                         struct rxrpc_connection *conn = call->conn;
 393                         uint32_t seq;
 394                         size_t pad;
 395
 396                         /* pad out if we're using security */
 397                         if (conn->security_ix) {
 398                                 pad = conn->security_size + skb->mark;
 399                                 pad = conn->size_align - pad;
 400                                 pad &= conn->size_align - 1;
 401                                 _debug("pad %zu", pad);
 402                                 if (pad)
 403                                         skb_put_zero(skb, pad);
 404                         }
 405
 406                         seq = call->tx_top + 1;
 407
 408                         sp->hdr.seq     = seq;
 409                         sp->hdr._rsvd   = 0;
 410                         sp->hdr.flags   = conn->out_clientflag;
 411
 412                         if (msg_data_left(msg) == 0 && !more)
 413                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 414                         else if (call->tx_top - call->tx_hard_ack <
 415                                  call->tx_winsize)
 416                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 417
 418                         ret = conn->security->secure_packet(
 419                                 call, skb, skb->mark, skb->head);
 420                         if (ret < 0)
 421                                 goto out;
 422
 423                         rxrpc_queue_packet(rx, call, skb,
 424                                            !msg_data_left(msg) && !more,
 425                                            notify_end_tx);
 426                         skb = NULL;
 427                 }
 428
 429                 /* Check for the far side aborting the call or a network error
 430                  * occurring.  If this happens, save any packet that was under
 431                  * construction so that in the case of a network error, the
 432                  * call can be retried or redirected.
 433                  */
 434                 if (call->state == RXRPC_CALL_COMPLETE) {
 435                         ret = call->error;
 436                         goto out;
 437                 }
 438         } while (msg_data_left(msg) > 0);
 439
 440 success:
 441         ret = copied;
 442 out:
 443         call->tx_pending = skb;
 444         _leave(" = %d", ret);
 445         return ret;
 446
 447 maybe_error:
 448         if (copied)
 449                 goto success;
 450         goto out;
 451
 452 efault:
 453         ret = -EFAULT;
 454         goto out;
 455 }
 456
 457 /*
 458  * extract control messages from the sendmsg() control buffer
 459  */
 460 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 461 {
 462         struct cmsghdr *cmsg;
 463         bool got_user_ID = false;
 464         int len;
 465
 466         if (msg->msg_controllen == 0)
 467                 return -EINVAL;
 468
 469         for_each_cmsghdr(cmsg, msg) {
 470                 if (!CMSG_OK(msg, cmsg))
 471                         return -EINVAL;
 472
 473                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 474                 _debug("CMSG %d, %d, %d",
 475                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 476
 477                 if (cmsg->cmsg_level != SOL_RXRPC)
 478                         continue;
 479
 480                 switch (cmsg->cmsg_type) {
 481                 case RXRPC_USER_CALL_ID:
 482                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 483                                 if (len != sizeof(u32))
 484                                         return -EINVAL;
 485                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 486                         } else {
 487                                 if (len != sizeof(unsigned long))
 488                                         return -EINVAL;
 489                                 p->call.user_call_ID = *(unsigned long *)
 490                                         CMSG_DATA(cmsg);
 491                         }
 492                         got_user_ID = true;
 493                         break;
 494
 495                 case RXRPC_ABORT:
 496                         if (p->command != RXRPC_CMD_SEND_DATA)
 497                                 return -EINVAL;
 498                         p->command = RXRPC_CMD_SEND_ABORT;
 499                         if (len != sizeof(p->abort_code))
 500                                 return -EINVAL;
 501                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 502                         if (p->abort_code == 0)
 503                                 return -EINVAL;
 504                         break;
 505
 506                 case RXRPC_ACCEPT:
 507                         if (p->command != RXRPC_CMD_SEND_DATA)
 508                                 return -EINVAL;
 509                         p->command = RXRPC_CMD_ACCEPT;
 510                         if (len != 0)
 511                                 return -EINVAL;
 512                         break;
 513
 514                 case RXRPC_EXCLUSIVE_CALL:
 515                         p->exclusive = true;
 516                         if (len != 0)
 517                                 return -EINVAL;
 518                         break;
 519
 520                 case RXRPC_UPGRADE_SERVICE:
 521                         p->upgrade = true;
 522                         if (len != 0)
 523                                 return -EINVAL;
 524                         break;
 525
 526                 case RXRPC_TX_LENGTH:
 527                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 528                                 return -EINVAL;
 529                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 530                         if (p->call.tx_total_len < 0)
 531                                 return -EINVAL;
 532                         break;
 533
 534                 case RXRPC_SET_CALL_TIMEOUT:
 535                         if (len & 3 || len < 4 || len > 12)
 536                                 return -EINVAL;
 537                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 538                         p->call.nr_timeouts = len / 4;
 539                         if (p->call.timeouts.hard > INT_MAX / HZ)
 540                                 return -ERANGE;
 541                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 542                                 return -ERANGE;
 543                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 544                                 return -ERANGE;
 545                         break;
 546
 547                 default:
 548                         return -EINVAL;
 549                 }
 550         }
 551
 552         if (!got_user_ID)
 553                 return -EINVAL;
 554         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 555                 return -EINVAL;
 556         _leave(" = 0");
 557         return 0;
 558 }
 559
 560 /*
 561  * Create a new client call for sendmsg().
 562  * - Called with the socket lock held, which it must release.
 563  * - If it returns a call, the call's lock will need releasing by the caller.
 564  */
 565 static struct rxrpc_call *
 566 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 567                                   struct rxrpc_send_params *p)
 568         __releases(&rx->sk.sk_lock.slock)
 569         __acquires(&call->user_mutex)
 570 {
 571         struct rxrpc_conn_parameters cp;
 572         struct rxrpc_call *call;
 573         struct key *key;
 574
 575         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 576
 577         _enter("");
 578
 579         if (!msg->msg_name) {
 580                 release_sock(&rx->sk);
 581                 return ERR_PTR(-EDESTADDRREQ);
 582         }
 583
 584         key = rx->key;
 585         if (key && !rx->key->payload.data[0])
 586                 key = NULL;
 587
 588         memset(&cp, 0, sizeof(cp));
 589         cp.local                = rx->local;
 590         cp.key                  = rx->key;
 591         cp.security_level       = rx->min_sec_level;
 592         cp.exclusive            = rx->exclusive | p->exclusive;
 593         cp.upgrade              = p->upgrade;
 594         cp.service_id           = srx->srx_service;
 595         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 596                                      atomic_inc_return(&rxrpc_debug_id));
 597         /* The socket is now unlocked */
 598
 599         rxrpc_put_peer(cp.peer);
 600         _leave(" = %p\n", call);
 601         return call;
 602 }
 603
 604 /*
 605  * send a message forming part of a client call through an RxRPC socket
 606  * - caller holds the socket locked
 607  * - the socket may be either a client socket or a server socket
 608  */
 609 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 610         __releases(&rx->sk.sk_lock.slock)
 611         __releases(&call->user_mutex)
 612 {
 613         enum rxrpc_call_state state;
 614         struct rxrpc_call *call;
 615         unsigned long now, j;
 616         int ret;
 617
 618         struct rxrpc_send_params p = {
 619                 .call.tx_total_len      = -1,
 620                 .call.user_call_ID      = 0,
 621                 .call.nr_timeouts       = 0,
 622                 .abort_code             = 0,
 623                 .command                = RXRPC_CMD_SEND_DATA,
 624                 .exclusive              = false,
 625                 .upgrade                = false,
 626         };
 627
 628         _enter("");
 629
 630         ret = rxrpc_sendmsg_cmsg(msg, &p);
 631         if (ret < 0)
 632                 goto error_release_sock;
 633
 634         if (p.command == RXRPC_CMD_ACCEPT) {
 635                 ret = -EINVAL;
 636                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 637                         goto error_release_sock;
 638                 call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
 639                 /* The socket is now unlocked. */
 640                 if (IS_ERR(call))
 641                         return PTR_ERR(call);
 642                 ret = 0;
 643                 goto out_put_unlock;
 644         }
 645
 646         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 647         if (!call) {
 648                 ret = -EBADSLT;
 649                 if (p.command != RXRPC_CMD_SEND_DATA)
 650                         goto error_release_sock;
 651                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 652                 /* The socket is now unlocked... */
 653                 if (IS_ERR(call))
 654                         return PTR_ERR(call);
 655                 /* ... and we have the call lock. */
 656         } else {
 657                 switch (READ_ONCE(call->state)) {
 658                 case RXRPC_CALL_UNINITIALISED:
 659                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 660                 case RXRPC_CALL_SERVER_PREALLOC:
 661                 case RXRPC_CALL_SERVER_SECURING:
 662                 case RXRPC_CALL_SERVER_ACCEPTING:
 663                         ret = -EBUSY;
 664                         goto error_release_sock;
 665                 default:
 666                         break;
 667                 }
 668
 669                 ret = mutex_lock_interruptible(&call->user_mutex);
 670                 release_sock(&rx->sk);
 671                 if (ret < 0) {
 672                         ret = -ERESTARTSYS;
 673                         goto error_put;
 674                 }
 675
 676                 if (p.call.tx_total_len != -1) {
 677                         ret = -EINVAL;
 678                         if (call->tx_total_len != -1 ||
 679                             call->tx_pending ||
 680                             call->tx_top != 0)
 681                                 goto error_put;
 682                         call->tx_total_len = p.call.tx_total_len;
 683                 }
 684         }
 685
 686         switch (p.call.nr_timeouts) {
 687         case 3:
 688                 j = msecs_to_jiffies(p.call.timeouts.normal);
 689                 if (p.call.timeouts.normal > 0 && j == 0)
 690                         j = 1;
 691                 WRITE_ONCE(call->next_rx_timo, j);
 692                 /* Fall through */
 693         case 2:
 694                 j = msecs_to_jiffies(p.call.timeouts.idle);
 695                 if (p.call.timeouts.idle > 0 && j == 0)
 696                         j = 1;
 697                 WRITE_ONCE(call->next_req_timo, j);
 698                 /* Fall through */
 699         case 1:
 700                 if (p.call.timeouts.hard > 0) {
 701                         j = msecs_to_jiffies(p.call.timeouts.hard);
 702                         now = jiffies;
 703                         j += now;
 704                         WRITE_ONCE(call->expect_term_by, j);
 705                         rxrpc_reduce_call_timer(call, j, now,
 706                                                 rxrpc_timer_set_for_hard);
 707                 }
 708                 break;
 709         }
 710
 711         state = READ_ONCE(call->state);
 712         _debug("CALL %d USR %lx ST %d on CONN %p",
 713                call->debug_id, call->user_call_ID, state, call->conn);
 714
 715         if (state >= RXRPC_CALL_COMPLETE) {
 716                 /* it's too late for this call */
 717                 ret = -ESHUTDOWN;
 718         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 719                 ret = 0;
 720                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 721                         ret = rxrpc_send_abort_packet(call);
 722         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 723                 ret = -EINVAL;
 724         } else if (rxrpc_is_client_call(call) &&
 725                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 726                 /* request phase complete for this client call */
 727                 ret = -EPROTO;
 728         } else if (rxrpc_is_service_call(call) &&
 729                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 730                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 731                 /* Reply phase not begun or not complete for service call. */
 732                 ret = -EPROTO;
 733         } else {
 734                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 735         }
 736
 737 out_put_unlock:
 738         mutex_unlock(&call->user_mutex);
 739 error_put:
 740         rxrpc_put_call(call, rxrpc_call_put);
 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         int ret;
 767
 768         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 769
 770         ASSERTCMP(msg->msg_name, ==, NULL);
 771         ASSERTCMP(msg->msg_control, ==, NULL);
 772
 773         mutex_lock(&call->user_mutex);
 774
 775         _debug("CALL %d USR %lx ST %d on CONN %p",
 776                call->debug_id, call->user_call_ID, call->state, call->conn);
 777
 778         switch (READ_ONCE(call->state)) {
 779         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 780         case RXRPC_CALL_SERVER_ACK_REQUEST:
 781         case RXRPC_CALL_SERVER_SEND_REPLY:
 782                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 783                                       notify_end_tx);
 784                 break;
 785         case RXRPC_CALL_COMPLETE:
 786                 read_lock_bh(&call->state_lock);
 787                 ret = call->error;
 788                 read_unlock_bh(&call->state_lock);
 789                 break;
 790         default:
 791                 /* Request phase complete for this client call */
 792                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 793                 ret = -EPROTO;
 794                 break;
 795         }
 796
 797         mutex_unlock(&call->user_mutex);
 798         _leave(" = %d", ret);
 799         return ret;
 800 }
 801 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 802
 803 /**
 804  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 805  * @sock: The socket the call is on
 806  * @call: The call to be aborted
 807  * @abort_code: The abort code to stick into the ABORT packet
 808  * @error: Local error value
 809  * @why: 3-char string indicating why.
 810  *
 811  * Allow a kernel service to abort a call, if it's still in an abortable state
 812  * and return true if the call was aborted, false if it was already complete.
 813  */
 814 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 815                              u32 abort_code, int error, const char *why)
 816 {
 817         bool aborted;
 818
 819         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 820
 821         mutex_lock(&call->user_mutex);
 822
 823         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 824         if (aborted)
 825                 rxrpc_send_abort_packet(call);
 826
 827         mutex_unlock(&call->user_mutex);
 828         return aborted;
 829 }
 830 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 831
 832 /**
 833  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 834  * @sock: The socket the call is on
 835  * @call: The call to be informed
 836  * @tx_total_len: The amount of data to be transmitted for this call
 837  *
 838  * Allow a kernel service to set the total transmit length on a call.  This
 839  * allows buffer-to-packet encrypt-and-copy to be performed.
 840  *
 841  * This function is primarily for use for setting the reply length since the
 842  * request length can be set when beginning the call.
 843  */
 844 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 845                                 s64 tx_total_len)
 846 {
 847         WARN_ON(call->tx_total_len != -1);
 848         call->tx_total_len = tx_total_len;
 849 }
 850 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);