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 (test_bit(RXRPC_CALL_IS_INTR, &call->flags) &&
  84                     timeout == 0 &&
  85                     tx_win == tx_start && signal_pending(current))
  86                         return -EINTR;
  87
  88                 if (tx_win != tx_start) {
  89                         timeout = rtt2;
  90                         tx_start = tx_win;
  91                 }
  92
  93                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  94                 timeout = schedule_timeout(timeout);
  95         }
  96 }
  97
  98 /*
  99  * wait for space to appear in the transmit/ACK window
 100  * - caller holds the socket locked
 101  */
 102 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 103                                     struct rxrpc_call *call,
 104                                     long *timeo,
 105                                     bool waitall)
 106 {
 107         DECLARE_WAITQUEUE(myself, current);
 108         int ret;
 109
 110         _enter(",{%u,%u,%u}",
 111                call->tx_hard_ack, call->tx_top, call->tx_winsize);
 112
 113         add_wait_queue(&call->waitq, &myself);
 114
 115         if (waitall)
 116                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
 117         else
 118                 ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 119
 120         remove_wait_queue(&call->waitq, &myself);
 121         set_current_state(TASK_RUNNING);
 122         _leave(" = %d", ret);
 123         return ret;
 124 }
 125
 126 /*
 127  * Schedule an instant Tx resend.
 128  */
 129 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
 130 {
 131         spin_lock_bh(&call->lock);
 132
 133         if (call->state < RXRPC_CALL_COMPLETE) {
 134                 call->rxtx_annotations[ix] =
 135                         (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
 136                         RXRPC_TX_ANNO_RETRANS;
 137                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
 138                         rxrpc_queue_call(call);
 139         }
 140
 141         spin_unlock_bh(&call->lock);
 142 }
 143
 144 /*
 145  * Notify the owner of the call that the transmit phase is ended and the last
 146  * packet has been queued.
 147  */
 148 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 149                                 rxrpc_notify_end_tx_t notify_end_tx)
 150 {
 151         if (notify_end_tx)
 152                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 153 }
 154
 155 /*
 156  * Queue a DATA packet for transmission, set the resend timeout and send
 157  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 158  * in case the caller wants to do something with it.
 159  */
 160 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 161                               struct sk_buff *skb, bool last,
 162                               rxrpc_notify_end_tx_t notify_end_tx)
 163 {
 164         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 165         unsigned long now;
 166         rxrpc_seq_t seq = sp->hdr.seq;
 167         int ret, ix;
 168         u8 annotation = RXRPC_TX_ANNO_UNACK;
 169
 170         _net("queue skb %p [%d]", skb, seq);
 171
 172         ASSERTCMP(seq, ==, call->tx_top + 1);
 173
 174         if (last)
 175                 annotation |= RXRPC_TX_ANNO_LAST;
 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(" = %d", ret);
 256         return ret;
 257 }
 258
 259 /*
 260  * send data through a socket
 261  * - must be called in process context
 262  * - The caller holds the call user access mutex, but not the socket lock.
 263  */
 264 static int rxrpc_send_data(struct rxrpc_sock *rx,
 265                            struct rxrpc_call *call,
 266                            struct msghdr *msg, size_t len,
 267                            rxrpc_notify_end_tx_t notify_end_tx)
 268 {
 269         struct rxrpc_skb_priv *sp;
 270         struct sk_buff *skb;
 271         struct sock *sk = &rx->sk;
 272         long timeo;
 273         bool more;
 274         int ret, copied;
 275
 276         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 277
 278         /* this should be in poll */
 279         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 280
 281         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 282                 return -EPIPE;
 283
 284         more = msg->msg_flags & MSG_MORE;
 285
 286         if (call->tx_total_len != -1) {
 287                 if (len > call->tx_total_len)
 288                         return -EMSGSIZE;
 289                 if (!more && len != call->tx_total_len)
 290                         return -EMSGSIZE;
 291         }
 292
 293         skb = call->tx_pending;
 294         call->tx_pending = NULL;
 295         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 296
 297         copied = 0;
 298         do {
 299                 /* Check to see if there's a ping ACK to reply to. */
 300                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 301                         rxrpc_send_ack_packet(call, false, NULL);
 302
 303                 if (!skb) {
 304                         size_t size, chunk, max, space;
 305
 306                         _debug("alloc");
 307
 308                         if (call->tx_top - call->tx_hard_ack >=
 309                             min_t(unsigned int, call->tx_winsize,
 310                                   call->cong_cwnd + call->cong_extra)) {
 311                                 ret = -EAGAIN;
 312                                 if (msg->msg_flags & MSG_DONTWAIT)
 313                                         goto maybe_error;
 314                                 ret = rxrpc_wait_for_tx_window(rx, call,
 315                                                                &timeo,
 316                                                                msg->msg_flags & MSG_WAITALL);
 317                                 if (ret < 0)
 318                                         goto maybe_error;
 319                         }
 320
 321                         max = RXRPC_JUMBO_DATALEN;
 322                         max -= call->conn->security_size;
 323                         max &= ~(call->conn->size_align - 1UL);
 324
 325                         chunk = max;
 326                         if (chunk > msg_data_left(msg) && !more)
 327                                 chunk = msg_data_left(msg);
 328
 329                         space = chunk + call->conn->size_align;
 330                         space &= ~(call->conn->size_align - 1UL);
 331
 332                         size = space + call->conn->security_size;
 333
 334                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 335
 336                         /* create a buffer that we can retain until it's ACK'd */
 337                         skb = sock_alloc_send_skb(
 338                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 339                         if (!skb)
 340                                 goto maybe_error;
 341
 342                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 343
 344                         _debug("ALLOC SEND %p", skb);
 345
 346                         ASSERTCMP(skb->mark, ==, 0);
 347
 348                         _debug("HS: %u", call->conn->security_size);
 349                         skb_reserve(skb, call->conn->security_size);
 350                         skb->len += call->conn->security_size;
 351
 352                         sp = rxrpc_skb(skb);
 353                         sp->remain = chunk;
 354                         if (sp->remain > skb_tailroom(skb))
 355                                 sp->remain = skb_tailroom(skb);
 356
 357                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 358                                skb_headroom(skb),
 359                                skb_tailroom(skb),
 360                                skb_headlen(skb),
 361                                sp->remain);
 362
 363                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 364                 }
 365
 366                 _debug("append");
 367                 sp = rxrpc_skb(skb);
 368
 369                 /* append next segment of data to the current buffer */
 370                 if (msg_data_left(msg) > 0) {
 371                         int copy = skb_tailroom(skb);
 372                         ASSERTCMP(copy, >, 0);
 373                         if (copy > msg_data_left(msg))
 374                                 copy = msg_data_left(msg);
 375                         if (copy > sp->remain)
 376                                 copy = sp->remain;
 377
 378                         _debug("add");
 379                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 380                         _debug("added");
 381                         if (ret < 0)
 382                                 goto efault;
 383                         sp->remain -= copy;
 384                         skb->mark += copy;
 385                         copied += copy;
 386                         if (call->tx_total_len != -1)
 387                                 call->tx_total_len -= copy;
 388                 }
 389
 390                 /* check for the far side aborting the call or a network error
 391                  * occurring */
 392                 if (call->state == RXRPC_CALL_COMPLETE)
 393                         goto call_terminated;
 394
 395                 /* add the packet to the send queue if it's now full */
 396                 if (sp->remain <= 0 ||
 397                     (msg_data_left(msg) == 0 && !more)) {
 398                         struct rxrpc_connection *conn = call->conn;
 399                         uint32_t seq;
 400                         size_t pad;
 401
 402                         /* pad out if we're using security */
 403                         if (conn->security_ix) {
 404                                 pad = conn->security_size + skb->mark;
 405                                 pad = conn->size_align - pad;
 406                                 pad &= conn->size_align - 1;
 407                                 _debug("pad %zu", pad);
 408                                 if (pad)
 409                                         skb_put_zero(skb, pad);
 410                         }
 411
 412                         seq = call->tx_top + 1;
 413
 414                         sp->hdr.seq     = seq;
 415                         sp->hdr._rsvd   = 0;
 416                         sp->hdr.flags   = conn->out_clientflag;
 417
 418                         if (msg_data_left(msg) == 0 && !more)
 419                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 420                         else if (call->tx_top - call->tx_hard_ack <
 421                                  call->tx_winsize)
 422                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 423
 424                         ret = conn->security->secure_packet(
 425                                 call, skb, skb->mark, skb->head);
 426                         if (ret < 0)
 427                                 goto out;
 428
 429                         ret = rxrpc_queue_packet(rx, call, skb,
 430                                                  !msg_data_left(msg) && !more,
 431                                                  notify_end_tx);
 432                         /* Should check for failure here */
 433                         skb = NULL;
 434                 }
 435         } while (msg_data_left(msg) > 0);
 436
 437 success:
 438         ret = copied;
 439 out:
 440         call->tx_pending = skb;
 441         _leave(" = %d", ret);
 442         return ret;
 443
 444 call_terminated:
 445         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 446         _leave(" = %d", call->error);
 447         return call->error;
 448
 449 maybe_error:
 450         if (copied)
 451                 goto success;
 452         goto out;
 453
 454 efault:
 455         ret = -EFAULT;
 456         goto out;
 457 }
 458
 459 /*
 460  * extract control messages from the sendmsg() control buffer
 461  */
 462 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 463 {
 464         struct cmsghdr *cmsg;
 465         bool got_user_ID = false;
 466         int len;
 467
 468         if (msg->msg_controllen == 0)
 469                 return -EINVAL;
 470
 471         for_each_cmsghdr(cmsg, msg) {
 472                 if (!CMSG_OK(msg, cmsg))
 473                         return -EINVAL;
 474
 475                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 476                 _debug("CMSG %d, %d, %d",
 477                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 478
 479                 if (cmsg->cmsg_level != SOL_RXRPC)
 480                         continue;
 481
 482                 switch (cmsg->cmsg_type) {
 483                 case RXRPC_USER_CALL_ID:
 484                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 485                                 if (len != sizeof(u32))
 486                                         return -EINVAL;
 487                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 488                         } else {
 489                                 if (len != sizeof(unsigned long))
 490                                         return -EINVAL;
 491                                 p->call.user_call_ID = *(unsigned long *)
 492                                         CMSG_DATA(cmsg);
 493                         }
 494                         got_user_ID = true;
 495                         break;
 496
 497                 case RXRPC_ABORT:
 498                         if (p->command != RXRPC_CMD_SEND_DATA)
 499                                 return -EINVAL;
 500                         p->command = RXRPC_CMD_SEND_ABORT;
 501                         if (len != sizeof(p->abort_code))
 502                                 return -EINVAL;
 503                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 504                         if (p->abort_code == 0)
 505                                 return -EINVAL;
 506                         break;
 507
 508                 case RXRPC_ACCEPT:
 509                         if (p->command != RXRPC_CMD_SEND_DATA)
 510                                 return -EINVAL;
 511                         p->command = RXRPC_CMD_ACCEPT;
 512                         if (len != 0)
 513                                 return -EINVAL;
 514                         break;
 515
 516                 case RXRPC_EXCLUSIVE_CALL:
 517                         p->exclusive = true;
 518                         if (len != 0)
 519                                 return -EINVAL;
 520                         break;
 521
 522                 case RXRPC_UPGRADE_SERVICE:
 523                         p->upgrade = true;
 524                         if (len != 0)
 525                                 return -EINVAL;
 526                         break;
 527
 528                 case RXRPC_TX_LENGTH:
 529                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 530                                 return -EINVAL;
 531                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 532                         if (p->call.tx_total_len < 0)
 533                                 return -EINVAL;
 534                         break;
 535
 536                 case RXRPC_SET_CALL_TIMEOUT:
 537                         if (len & 3 || len < 4 || len > 12)
 538                                 return -EINVAL;
 539                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 540                         p->call.nr_timeouts = len / 4;
 541                         if (p->call.timeouts.hard > INT_MAX / HZ)
 542                                 return -ERANGE;
 543                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 544                                 return -ERANGE;
 545                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 546                                 return -ERANGE;
 547                         break;
 548
 549                 default:
 550                         return -EINVAL;
 551                 }
 552         }
 553
 554         if (!got_user_ID)
 555                 return -EINVAL;
 556         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 557                 return -EINVAL;
 558         _leave(" = 0");
 559         return 0;
 560 }
 561
 562 /*
 563  * Create a new client call for sendmsg().
 564  * - Called with the socket lock held, which it must release.
 565  * - If it returns a call, the call's lock will need releasing by the caller.
 566  */
 567 static struct rxrpc_call *
 568 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 569                                   struct rxrpc_send_params *p)
 570         __releases(&rx->sk.sk_lock.slock)
 571         __acquires(&call->user_mutex)
 572 {
 573         struct rxrpc_conn_parameters cp;
 574         struct rxrpc_call *call;
 575         struct key *key;
 576
 577         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 578
 579         _enter("");
 580
 581         if (!msg->msg_name) {
 582                 release_sock(&rx->sk);
 583                 return ERR_PTR(-EDESTADDRREQ);
 584         }
 585
 586         key = rx->key;
 587         if (key && !rx->key->payload.data[0])
 588                 key = NULL;
 589
 590         memset(&cp, 0, sizeof(cp));
 591         cp.local                = rx->local;
 592         cp.key                  = rx->key;
 593         cp.security_level       = rx->min_sec_level;
 594         cp.exclusive            = rx->exclusive | p->exclusive;
 595         cp.upgrade              = p->upgrade;
 596         cp.service_id           = srx->srx_service;
 597         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 598                                      atomic_inc_return(&rxrpc_debug_id));
 599         /* The socket is now unlocked */
 600
 601         rxrpc_put_peer(cp.peer);
 602         _leave(" = %p\n", call);
 603         return call;
 604 }
 605
 606 /*
 607  * send a message forming part of a client call through an RxRPC socket
 608  * - caller holds the socket locked
 609  * - the socket may be either a client socket or a server socket
 610  */
 611 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 612         __releases(&rx->sk.sk_lock.slock)
 613         __releases(&call->user_mutex)
 614 {
 615         enum rxrpc_call_state state;
 616         struct rxrpc_call *call;
 617         unsigned long now, j;
 618         int ret;
 619
 620         struct rxrpc_send_params p = {
 621                 .call.tx_total_len      = -1,
 622                 .call.user_call_ID      = 0,
 623                 .call.nr_timeouts       = 0,
 624                 .call.intr              = true,
 625                 .abort_code             = 0,
 626                 .command                = RXRPC_CMD_SEND_DATA,
 627                 .exclusive              = false,
 628                 .upgrade                = false,
 629         };
 630
 631         _enter("");
 632
 633         ret = rxrpc_sendmsg_cmsg(msg, &p);
 634         if (ret < 0)
 635                 goto error_release_sock;
 636
 637         if (p.command == RXRPC_CMD_ACCEPT) {
 638                 ret = -EINVAL;
 639                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 640                         goto error_release_sock;
 641                 call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
 642                 /* The socket is now unlocked. */
 643                 if (IS_ERR(call))
 644                         return PTR_ERR(call);
 645                 ret = 0;
 646                 goto out_put_unlock;
 647         }
 648
 649         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 650         if (!call) {
 651                 ret = -EBADSLT;
 652                 if (p.command != RXRPC_CMD_SEND_DATA)
 653                         goto error_release_sock;
 654                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 655                 /* The socket is now unlocked... */
 656                 if (IS_ERR(call))
 657                         return PTR_ERR(call);
 658                 /* ... and we have the call lock. */
 659         } else {
 660                 switch (READ_ONCE(call->state)) {
 661                 case RXRPC_CALL_UNINITIALISED:
 662                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 663                 case RXRPC_CALL_SERVER_PREALLOC:
 664                 case RXRPC_CALL_SERVER_SECURING:
 665                 case RXRPC_CALL_SERVER_ACCEPTING:
 666                         ret = -EBUSY;
 667                         goto error_release_sock;
 668                 default:
 669                         break;
 670                 }
 671
 672                 ret = mutex_lock_interruptible(&call->user_mutex);
 673                 release_sock(&rx->sk);
 674                 if (ret < 0) {
 675                         ret = -ERESTARTSYS;
 676                         goto error_put;
 677                 }
 678
 679                 if (p.call.tx_total_len != -1) {
 680                         ret = -EINVAL;
 681                         if (call->tx_total_len != -1 ||
 682                             call->tx_pending ||
 683                             call->tx_top != 0)
 684                                 goto error_put;
 685                         call->tx_total_len = p.call.tx_total_len;
 686                 }
 687         }
 688
 689         switch (p.call.nr_timeouts) {
 690         case 3:
 691                 j = msecs_to_jiffies(p.call.timeouts.normal);
 692                 if (p.call.timeouts.normal > 0 && j == 0)
 693                         j = 1;
 694                 WRITE_ONCE(call->next_rx_timo, j);
 695                 /* Fall through */
 696         case 2:
 697                 j = msecs_to_jiffies(p.call.timeouts.idle);
 698                 if (p.call.timeouts.idle > 0 && j == 0)
 699                         j = 1;
 700                 WRITE_ONCE(call->next_req_timo, j);
 701                 /* Fall through */
 702         case 1:
 703                 if (p.call.timeouts.hard > 0) {
 704                         j = msecs_to_jiffies(p.call.timeouts.hard);
 705                         now = jiffies;
 706                         j += now;
 707                         WRITE_ONCE(call->expect_term_by, j);
 708                         rxrpc_reduce_call_timer(call, j, now,
 709                                                 rxrpc_timer_set_for_hard);
 710                 }
 711                 break;
 712         }
 713
 714         state = READ_ONCE(call->state);
 715         _debug("CALL %d USR %lx ST %d on CONN %p",
 716                call->debug_id, call->user_call_ID, state, call->conn);
 717
 718         if (state >= RXRPC_CALL_COMPLETE) {
 719                 /* it's too late for this call */
 720                 ret = -ESHUTDOWN;
 721         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 722                 ret = 0;
 723                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 724                         ret = rxrpc_send_abort_packet(call);
 725         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 726                 ret = -EINVAL;
 727         } else if (rxrpc_is_client_call(call) &&
 728                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 729                 /* request phase complete for this client call */
 730                 ret = -EPROTO;
 731         } else if (rxrpc_is_service_call(call) &&
 732                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 733                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 734                 /* Reply phase not begun or not complete for service call. */
 735                 ret = -EPROTO;
 736         } else {
 737                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 738         }
 739
 740 out_put_unlock:
 741         mutex_unlock(&call->user_mutex);
 742 error_put:
 743         rxrpc_put_call(call, rxrpc_call_put);
 744         _leave(" = %d", ret);
 745         return ret;
 746
 747 error_release_sock:
 748         release_sock(&rx->sk);
 749         return ret;
 750 }
 751
 752 /**
 753  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 754  * @sock: The socket the call is on
 755  * @call: The call to send data through
 756  * @msg: The data to send
 757  * @len: The amount of data to send
 758  * @notify_end_tx: Notification that the last packet is queued.
 759  *
 760  * Allow a kernel service to send data on a call.  The call must be in an state
 761  * appropriate to sending data.  No control data should be supplied in @msg,
 762  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 763  * more data to come, otherwise this data will end the transmission phase.
 764  */
 765 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 766                            struct msghdr *msg, size_t len,
 767                            rxrpc_notify_end_tx_t notify_end_tx)
 768 {
 769         int ret;
 770
 771         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 772
 773         ASSERTCMP(msg->msg_name, ==, NULL);
 774         ASSERTCMP(msg->msg_control, ==, NULL);
 775
 776         mutex_lock(&call->user_mutex);
 777
 778         _debug("CALL %d USR %lx ST %d on CONN %p",
 779                call->debug_id, call->user_call_ID, call->state, call->conn);
 780
 781         switch (READ_ONCE(call->state)) {
 782         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 783         case RXRPC_CALL_SERVER_ACK_REQUEST:
 784         case RXRPC_CALL_SERVER_SEND_REPLY:
 785                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 786                                       notify_end_tx);
 787                 break;
 788         case RXRPC_CALL_COMPLETE:
 789                 read_lock_bh(&call->state_lock);
 790                 ret = call->error;
 791                 read_unlock_bh(&call->state_lock);
 792                 break;
 793         default:
 794                 /* Request phase complete for this client call */
 795                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 796                 ret = -EPROTO;
 797                 break;
 798         }
 799
 800         mutex_unlock(&call->user_mutex);
 801         _leave(" = %d", ret);
 802         return ret;
 803 }
 804 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 805
 806 /**
 807  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 808  * @sock: The socket the call is on
 809  * @call: The call to be aborted
 810  * @abort_code: The abort code to stick into the ABORT packet
 811  * @error: Local error value
 812  * @why: 3-char string indicating why.
 813  *
 814  * Allow a kernel service to abort a call, if it's still in an abortable state
 815  * and return true if the call was aborted, false if it was already complete.
 816  */
 817 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 818                              u32 abort_code, int error, const char *why)
 819 {
 820         bool aborted;
 821
 822         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 823
 824         mutex_lock(&call->user_mutex);
 825
 826         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 827         if (aborted)
 828                 rxrpc_send_abort_packet(call);
 829
 830         mutex_unlock(&call->user_mutex);
 831         return aborted;
 832 }
 833 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 834
 835 /**
 836  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 837  * @sock: The socket the call is on
 838  * @call: The call to be informed
 839  * @tx_total_len: The amount of data to be transmitted for this call
 840  *
 841  * Allow a kernel service to set the total transmit length on a call.  This
 842  * allows buffer-to-packet encrypt-and-copy to be performed.
 843  *
 844  * This function is primarily for use for setting the reply length since the
 845  * request length can be set when beginning the call.
 846  */
 847 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 848                                 s64 tx_total_len)
 849 {
 850         WARN_ON(call->tx_total_len != -1);
 851         call->tx_total_len = tx_total_len;
 852 }
 853 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);