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