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
 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                 switch (ret) {
 225                 case -ENETUNREACH:
 226                 case -EHOSTUNREACH:
 227                 case -ECONNREFUSED:
 228                         rxrpc_set_call_completion(call,
 229                                                   RXRPC_CALL_LOCAL_ERROR,
 230                                                   0, ret);
 231                         goto out;
 232                 }
 233                 _debug("need instant resend %d", ret);
 234                 rxrpc_instant_resend(call, ix);
 235         } else {
 236                 unsigned long now = jiffies, resend_at;
 237
 238                 if (call->peer->rtt_usage > 1)
 239                         resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
 240                 else
 241                         resend_at = rxrpc_resend_timeout;
 242                 if (resend_at < 1)
 243                         resend_at = 1;
 244
 245                 resend_at += now;
 246                 WRITE_ONCE(call->resend_at, resend_at);
 247                 rxrpc_reduce_call_timer(call, resend_at, now,
 248                                         rxrpc_timer_set_for_send);
 249         }
 250
 251 out:
 252         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 253         _leave("");
 254 }
 255
 256 /*
 257  * send data through a socket
 258  * - must be called in process context
 259  * - The caller holds the call user access mutex, but not the socket lock.
 260  */
 261 static int rxrpc_send_data(struct rxrpc_sock *rx,
 262                            struct rxrpc_call *call,
 263                            struct msghdr *msg, size_t len,
 264                            rxrpc_notify_end_tx_t notify_end_tx)
 265 {
 266         struct rxrpc_skb_priv *sp;
 267         struct sk_buff *skb;
 268         struct sock *sk = &rx->sk;
 269         long timeo;
 270         bool more;
 271         int ret, copied;
 272
 273         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 274
 275         /* this should be in poll */
 276         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 277
 278         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 279                 return -EPIPE;
 280
 281         more = msg->msg_flags & MSG_MORE;
 282
 283         if (call->tx_total_len != -1) {
 284                 if (len > call->tx_total_len)
 285                         return -EMSGSIZE;
 286                 if (!more && len != call->tx_total_len)
 287                         return -EMSGSIZE;
 288         }
 289
 290         skb = call->tx_pending;
 291         call->tx_pending = NULL;
 292         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 293
 294         copied = 0;
 295         do {
 296                 /* Check to see if there's a ping ACK to reply to. */
 297                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 298                         rxrpc_send_ack_packet(call, false, NULL);
 299
 300                 if (!skb) {
 301                         size_t size, chunk, max, space;
 302
 303                         _debug("alloc");
 304
 305                         if (call->tx_top - call->tx_hard_ack >=
 306                             min_t(unsigned int, call->tx_winsize,
 307                                   call->cong_cwnd + call->cong_extra)) {
 308                                 ret = -EAGAIN;
 309                                 if (msg->msg_flags & MSG_DONTWAIT)
 310                                         goto maybe_error;
 311                                 ret = rxrpc_wait_for_tx_window(rx, call,
 312                                                                &timeo,
 313                                                                msg->msg_flags & MSG_WAITALL);
 314                                 if (ret < 0)
 315                                         goto maybe_error;
 316                         }
 317
 318                         max = RXRPC_JUMBO_DATALEN;
 319                         max -= call->conn->security_size;
 320                         max &= ~(call->conn->size_align - 1UL);
 321
 322                         chunk = max;
 323                         if (chunk > msg_data_left(msg) && !more)
 324                                 chunk = msg_data_left(msg);
 325
 326                         space = chunk + call->conn->size_align;
 327                         space &= ~(call->conn->size_align - 1UL);
 328
 329                         size = space + call->conn->security_size;
 330
 331                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 332
 333                         /* create a buffer that we can retain until it's ACK'd */
 334                         skb = sock_alloc_send_skb(
 335                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 336                         if (!skb)
 337                                 goto maybe_error;
 338
 339                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 340
 341                         _debug("ALLOC SEND %p", skb);
 342
 343                         ASSERTCMP(skb->mark, ==, 0);
 344
 345                         _debug("HS: %u", call->conn->security_size);
 346                         skb_reserve(skb, call->conn->security_size);
 347                         skb->len += call->conn->security_size;
 348
 349                         sp = rxrpc_skb(skb);
 350                         sp->remain = chunk;
 351                         if (sp->remain > skb_tailroom(skb))
 352                                 sp->remain = skb_tailroom(skb);
 353
 354                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 355                                skb_headroom(skb),
 356                                skb_tailroom(skb),
 357                                skb_headlen(skb),
 358                                sp->remain);
 359
 360                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 361                 }
 362
 363                 _debug("append");
 364                 sp = rxrpc_skb(skb);
 365
 366                 /* append next segment of data to the current buffer */
 367                 if (msg_data_left(msg) > 0) {
 368                         int copy = skb_tailroom(skb);
 369                         ASSERTCMP(copy, >, 0);
 370                         if (copy > msg_data_left(msg))
 371                                 copy = msg_data_left(msg);
 372                         if (copy > sp->remain)
 373                                 copy = sp->remain;
 374
 375                         _debug("add");
 376                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 377                         _debug("added");
 378                         if (ret < 0)
 379                                 goto efault;
 380                         sp->remain -= copy;
 381                         skb->mark += copy;
 382                         copied += copy;
 383                         if (call->tx_total_len != -1)
 384                                 call->tx_total_len -= copy;
 385                 }
 386
 387                 /* check for the far side aborting the call or a network error
 388                  * occurring */
 389                 if (call->state == RXRPC_CALL_COMPLETE)
 390                         goto call_terminated;
 391
 392                 /* add the packet to the send queue if it's now full */
 393                 if (sp->remain <= 0 ||
 394                     (msg_data_left(msg) == 0 && !more)) {
 395                         struct rxrpc_connection *conn = call->conn;
 396                         uint32_t seq;
 397                         size_t pad;
 398
 399                         /* pad out if we're using security */
 400                         if (conn->security_ix) {
 401                                 pad = conn->security_size + skb->mark;
 402                                 pad = conn->size_align - pad;
 403                                 pad &= conn->size_align - 1;
 404                                 _debug("pad %zu", pad);
 405                                 if (pad)
 406                                         skb_put_zero(skb, pad);
 407                         }
 408
 409                         seq = call->tx_top + 1;
 410
 411                         sp->hdr.seq     = seq;
 412                         sp->hdr._rsvd   = 0;
 413                         sp->hdr.flags   = conn->out_clientflag;
 414
 415                         if (msg_data_left(msg) == 0 && !more)
 416                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 417                         else if (call->tx_top - call->tx_hard_ack <
 418                                  call->tx_winsize)
 419                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 420
 421                         ret = conn->security->secure_packet(
 422                                 call, skb, skb->mark, skb->head);
 423                         if (ret < 0)
 424                                 goto out;
 425
 426                         rxrpc_queue_packet(rx, call, skb,
 427                                            !msg_data_left(msg) && !more,
 428                                            notify_end_tx);
 429                         skb = NULL;
 430                 }
 431         } while (msg_data_left(msg) > 0);
 432
 433 success:
 434         ret = copied;
 435 out:
 436         call->tx_pending = skb;
 437         _leave(" = %d", ret);
 438         return ret;
 439
 440 call_terminated:
 441         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 442         _leave(" = %d", call->error);
 443         return call->error;
 444
 445 maybe_error:
 446         if (copied)
 447                 goto success;
 448         goto out;
 449
 450 efault:
 451         ret = -EFAULT;
 452         goto out;
 453 }
 454
 455 /*
 456  * extract control messages from the sendmsg() control buffer
 457  */
 458 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 459 {
 460         struct cmsghdr *cmsg;
 461         bool got_user_ID = false;
 462         int len;
 463
 464         if (msg->msg_controllen == 0)
 465                 return -EINVAL;
 466
 467         for_each_cmsghdr(cmsg, msg) {
 468                 if (!CMSG_OK(msg, cmsg))
 469                         return -EINVAL;
 470
 471                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 472                 _debug("CMSG %d, %d, %d",
 473                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 474
 475                 if (cmsg->cmsg_level != SOL_RXRPC)
 476                         continue;
 477
 478                 switch (cmsg->cmsg_type) {
 479                 case RXRPC_USER_CALL_ID:
 480                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 481                                 if (len != sizeof(u32))
 482                                         return -EINVAL;
 483                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 484                         } else {
 485                                 if (len != sizeof(unsigned long))
 486                                         return -EINVAL;
 487                                 p->call.user_call_ID = *(unsigned long *)
 488                                         CMSG_DATA(cmsg);
 489                         }
 490                         got_user_ID = true;
 491                         break;
 492
 493                 case RXRPC_ABORT:
 494                         if (p->command != RXRPC_CMD_SEND_DATA)
 495                                 return -EINVAL;
 496                         p->command = RXRPC_CMD_SEND_ABORT;
 497                         if (len != sizeof(p->abort_code))
 498                                 return -EINVAL;
 499                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 500                         if (p->abort_code == 0)
 501                                 return -EINVAL;
 502                         break;
 503
 504                 case RXRPC_ACCEPT:
 505                         if (p->command != RXRPC_CMD_SEND_DATA)
 506                                 return -EINVAL;
 507                         p->command = RXRPC_CMD_ACCEPT;
 508                         if (len != 0)
 509                                 return -EINVAL;
 510                         break;
 511
 512                 case RXRPC_EXCLUSIVE_CALL:
 513                         p->exclusive = true;
 514                         if (len != 0)
 515                                 return -EINVAL;
 516                         break;
 517
 518                 case RXRPC_UPGRADE_SERVICE:
 519                         p->upgrade = true;
 520                         if (len != 0)
 521                                 return -EINVAL;
 522                         break;
 523
 524                 case RXRPC_TX_LENGTH:
 525                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 526                                 return -EINVAL;
 527                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 528                         if (p->call.tx_total_len < 0)
 529                                 return -EINVAL;
 530                         break;
 531
 532                 case RXRPC_SET_CALL_TIMEOUT:
 533                         if (len & 3 || len < 4 || len > 12)
 534                                 return -EINVAL;
 535                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 536                         p->call.nr_timeouts = len / 4;
 537                         if (p->call.timeouts.hard > INT_MAX / HZ)
 538                                 return -ERANGE;
 539                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 540                                 return -ERANGE;
 541                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 542                                 return -ERANGE;
 543                         break;
 544
 545                 default:
 546                         return -EINVAL;
 547                 }
 548         }
 549
 550         if (!got_user_ID)
 551                 return -EINVAL;
 552         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 553                 return -EINVAL;
 554         _leave(" = 0");
 555         return 0;
 556 }
 557
 558 /*
 559  * Create a new client call for sendmsg().
 560  * - Called with the socket lock held, which it must release.
 561  * - If it returns a call, the call's lock will need releasing by the caller.
 562  */
 563 static struct rxrpc_call *
 564 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 565                                   struct rxrpc_send_params *p)
 566         __releases(&rx->sk.sk_lock.slock)
 567         __acquires(&call->user_mutex)
 568 {
 569         struct rxrpc_conn_parameters cp;
 570         struct rxrpc_call *call;
 571         struct key *key;
 572
 573         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 574
 575         _enter("");
 576
 577         if (!msg->msg_name) {
 578                 release_sock(&rx->sk);
 579                 return ERR_PTR(-EDESTADDRREQ);
 580         }
 581
 582         key = rx->key;
 583         if (key && !rx->key->payload.data[0])
 584                 key = NULL;
 585
 586         memset(&cp, 0, sizeof(cp));
 587         cp.local                = rx->local;
 588         cp.key                  = rx->key;
 589         cp.security_level       = rx->min_sec_level;
 590         cp.exclusive            = rx->exclusive | p->exclusive;
 591         cp.upgrade              = p->upgrade;
 592         cp.service_id           = srx->srx_service;
 593         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 594                                      atomic_inc_return(&rxrpc_debug_id));
 595         /* The socket is now unlocked */
 596
 597         rxrpc_put_peer(cp.peer);
 598         _leave(" = %p\n", call);
 599         return call;
 600 }
 601
 602 /*
 603  * send a message forming part of a client call through an RxRPC socket
 604  * - caller holds the socket locked
 605  * - the socket may be either a client socket or a server socket
 606  */
 607 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 608         __releases(&rx->sk.sk_lock.slock)
 609         __releases(&call->user_mutex)
 610 {
 611         enum rxrpc_call_state state;
 612         struct rxrpc_call *call;
 613         unsigned long now, j;
 614         int ret;
 615
 616         struct rxrpc_send_params p = {
 617                 .call.tx_total_len      = -1,
 618                 .call.user_call_ID      = 0,
 619                 .call.nr_timeouts       = 0,
 620                 .abort_code             = 0,
 621                 .command                = RXRPC_CMD_SEND_DATA,
 622                 .exclusive              = false,
 623                 .upgrade                = false,
 624         };
 625
 626         _enter("");
 627
 628         ret = rxrpc_sendmsg_cmsg(msg, &p);
 629         if (ret < 0)
 630                 goto error_release_sock;
 631
 632         if (p.command == RXRPC_CMD_ACCEPT) {
 633                 ret = -EINVAL;
 634                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 635                         goto error_release_sock;
 636                 call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
 637                 /* The socket is now unlocked. */
 638                 if (IS_ERR(call))
 639                         return PTR_ERR(call);
 640                 ret = 0;
 641                 goto out_put_unlock;
 642         }
 643
 644         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 645         if (!call) {
 646                 ret = -EBADSLT;
 647                 if (p.command != RXRPC_CMD_SEND_DATA)
 648                         goto error_release_sock;
 649                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 650                 /* The socket is now unlocked... */
 651                 if (IS_ERR(call))
 652                         return PTR_ERR(call);
 653                 /* ... and we have the call lock. */
 654         } else {
 655                 switch (READ_ONCE(call->state)) {
 656                 case RXRPC_CALL_UNINITIALISED:
 657                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 658                 case RXRPC_CALL_SERVER_PREALLOC:
 659                 case RXRPC_CALL_SERVER_SECURING:
 660                 case RXRPC_CALL_SERVER_ACCEPTING:
 661                         ret = -EBUSY;
 662                         goto error_release_sock;
 663                 default:
 664                         break;
 665                 }
 666
 667                 ret = mutex_lock_interruptible(&call->user_mutex);
 668                 release_sock(&rx->sk);
 669                 if (ret < 0) {
 670                         ret = -ERESTARTSYS;
 671                         goto error_put;
 672                 }
 673
 674                 if (p.call.tx_total_len != -1) {
 675                         ret = -EINVAL;
 676                         if (call->tx_total_len != -1 ||
 677                             call->tx_pending ||
 678                             call->tx_top != 0)
 679                                 goto error_put;
 680                         call->tx_total_len = p.call.tx_total_len;
 681                 }
 682         }
 683
 684         switch (p.call.nr_timeouts) {
 685         case 3:
 686                 j = msecs_to_jiffies(p.call.timeouts.normal);
 687                 if (p.call.timeouts.normal > 0 && j == 0)
 688                         j = 1;
 689                 WRITE_ONCE(call->next_rx_timo, j);
 690                 /* Fall through */
 691         case 2:
 692                 j = msecs_to_jiffies(p.call.timeouts.idle);
 693                 if (p.call.timeouts.idle > 0 && j == 0)
 694                         j = 1;
 695                 WRITE_ONCE(call->next_req_timo, j);
 696                 /* Fall through */
 697         case 1:
 698                 if (p.call.timeouts.hard > 0) {
 699                         j = msecs_to_jiffies(p.call.timeouts.hard);
 700                         now = jiffies;
 701                         j += now;
 702                         WRITE_ONCE(call->expect_term_by, j);
 703                         rxrpc_reduce_call_timer(call, j, now,
 704                                                 rxrpc_timer_set_for_hard);
 705                 }
 706                 break;
 707         }
 708
 709         state = READ_ONCE(call->state);
 710         _debug("CALL %d USR %lx ST %d on CONN %p",
 711                call->debug_id, call->user_call_ID, state, call->conn);
 712
 713         if (state >= RXRPC_CALL_COMPLETE) {
 714                 /* it's too late for this call */
 715                 ret = -ESHUTDOWN;
 716         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 717                 ret = 0;
 718                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 719                         ret = rxrpc_send_abort_packet(call);
 720         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 721                 ret = -EINVAL;
 722         } else if (rxrpc_is_client_call(call) &&
 723                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 724                 /* request phase complete for this client call */
 725                 ret = -EPROTO;
 726         } else if (rxrpc_is_service_call(call) &&
 727                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 728                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 729                 /* Reply phase not begun or not complete for service call. */
 730                 ret = -EPROTO;
 731         } else {
 732                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 733         }
 734
 735 out_put_unlock:
 736         mutex_unlock(&call->user_mutex);
 737 error_put:
 738         rxrpc_put_call(call, rxrpc_call_put);
 739         _leave(" = %d", ret);
 740         return ret;
 741
 742 error_release_sock:
 743         release_sock(&rx->sk);
 744         return ret;
 745 }
 746
 747 /**
 748  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 749  * @sock: The socket the call is on
 750  * @call: The call to send data through
 751  * @msg: The data to send
 752  * @len: The amount of data to send
 753  * @notify_end_tx: Notification that the last packet is queued.
 754  *
 755  * Allow a kernel service to send data on a call.  The call must be in an state
 756  * appropriate to sending data.  No control data should be supplied in @msg,
 757  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 758  * more data to come, otherwise this data will end the transmission phase.
 759  */
 760 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 761                            struct msghdr *msg, size_t len,
 762                            rxrpc_notify_end_tx_t notify_end_tx)
 763 {
 764         int ret;
 765
 766         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 767
 768         ASSERTCMP(msg->msg_name, ==, NULL);
 769         ASSERTCMP(msg->msg_control, ==, NULL);
 770
 771         mutex_lock(&call->user_mutex);
 772
 773         _debug("CALL %d USR %lx ST %d on CONN %p",
 774                call->debug_id, call->user_call_ID, call->state, call->conn);
 775
 776         switch (READ_ONCE(call->state)) {
 777         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 778         case RXRPC_CALL_SERVER_ACK_REQUEST:
 779         case RXRPC_CALL_SERVER_SEND_REPLY:
 780                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 781                                       notify_end_tx);
 782                 break;
 783         case RXRPC_CALL_COMPLETE:
 784                 read_lock_bh(&call->state_lock);
 785                 ret = call->error;
 786                 read_unlock_bh(&call->state_lock);
 787                 break;
 788         default:
 789                 /* Request phase complete for this client call */
 790                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 791                 ret = -EPROTO;
 792                 break;
 793         }
 794
 795         mutex_unlock(&call->user_mutex);
 796         _leave(" = %d", ret);
 797         return ret;
 798 }
 799 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 800
 801 /**
 802  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 803  * @sock: The socket the call is on
 804  * @call: The call to be aborted
 805  * @abort_code: The abort code to stick into the ABORT packet
 806  * @error: Local error value
 807  * @why: 3-char string indicating why.
 808  *
 809  * Allow a kernel service to abort a call, if it's still in an abortable state
 810  * and return true if the call was aborted, false if it was already complete.
 811  */
 812 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 813                              u32 abort_code, int error, const char *why)
 814 {
 815         bool aborted;
 816
 817         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 818
 819         mutex_lock(&call->user_mutex);
 820
 821         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 822         if (aborted)
 823                 rxrpc_send_abort_packet(call);
 824
 825         mutex_unlock(&call->user_mutex);
 826         return aborted;
 827 }
 828 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 829
 830 /**
 831  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 832  * @sock: The socket the call is on
 833  * @call: The call to be informed
 834  * @tx_total_len: The amount of data to be transmitted for this call
 835  *
 836  * Allow a kernel service to set the total transmit length on a call.  This
 837  * allows buffer-to-packet encrypt-and-copy to be performed.
 838  *
 839  * This function is primarily for use for setting the reply length since the
 840  * request length can be set when beginning the call.
 841  */
 842 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 843                                 s64 tx_total_len)
 844 {
 845         WARN_ON(call->tx_total_len != -1);
 846         call->tx_total_len = tx_total_len;
 847 }
 848 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);