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 enum rxrpc_command {
  25         RXRPC_CMD_SEND_DATA,            /* send data message */
  26         RXRPC_CMD_SEND_ABORT,           /* request abort generation */
  27         RXRPC_CMD_ACCEPT,               /* [server] accept incoming call */
  28         RXRPC_CMD_REJECT_BUSY,          /* [server] reject a call as busy */
  29 };
  30
  31 struct rxrpc_send_params {
  32         s64                     tx_total_len;   /* Total Tx data length (if send data) */
  33         unsigned long           user_call_ID;   /* User's call ID */
  34         u32                     abort_code;     /* Abort code to Tx (if abort) */
  35         enum rxrpc_command      command : 8;    /* The command to implement */
  36         bool                    exclusive;      /* Shared or exclusive call */
  37         bool                    upgrade;        /* If the connection is upgradeable */
  38 };
  39
  40 /*
  41  * wait for space to appear in the transmit/ACK window
  42  * - caller holds the socket locked
  43  */
  44 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
  45                                     struct rxrpc_call *call,
  46                                     long *timeo)
  47 {
  48         DECLARE_WAITQUEUE(myself, current);
  49         int ret;
  50
  51         _enter(",{%u,%u,%u}",
  52                call->tx_hard_ack, call->tx_top, call->tx_winsize);
  53
  54         add_wait_queue(&call->waitq, &myself);
  55
  56         for (;;) {
  57                 set_current_state(TASK_INTERRUPTIBLE);
  58                 ret = 0;
  59                 if (call->tx_top - call->tx_hard_ack <
  60                     min_t(unsigned int, call->tx_winsize,
  61                           call->cong_cwnd + call->cong_extra))
  62                         break;
  63                 if (call->state >= RXRPC_CALL_COMPLETE) {
  64                         ret = call->error;
  65                         break;
  66                 }
  67                 if (signal_pending(current)) {
  68                         ret = sock_intr_errno(*timeo);
  69                         break;
  70                 }
  71
  72                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  73                 mutex_unlock(&call->user_mutex);
  74                 *timeo = schedule_timeout(*timeo);
  75                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
  76                         ret = sock_intr_errno(*timeo);
  77                         break;
  78                 }
  79         }
  80
  81         remove_wait_queue(&call->waitq, &myself);
  82         set_current_state(TASK_RUNNING);
  83         _leave(" = %d", ret);
  84         return ret;
  85 }
  86
  87 /*
  88  * Schedule an instant Tx resend.
  89  */
  90 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
  91 {
  92         spin_lock_bh(&call->lock);
  93
  94         if (call->state < RXRPC_CALL_COMPLETE) {
  95                 call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
  96                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
  97                         rxrpc_queue_call(call);
  98         }
  99
 100         spin_unlock_bh(&call->lock);
 101 }
 102
 103 /*
 104  * Notify the owner of the call that the transmit phase is ended and the last
 105  * packet has been queued.
 106  */
 107 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 108                                 rxrpc_notify_end_tx_t notify_end_tx)
 109 {
 110         if (notify_end_tx)
 111                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 112 }
 113
 114 /*
 115  * Queue a DATA packet for transmission, set the resend timeout and send the
 116  * packet immediately
 117  */
 118 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 119                                struct sk_buff *skb, bool last,
 120                                rxrpc_notify_end_tx_t notify_end_tx)
 121 {
 122         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 123         rxrpc_seq_t seq = sp->hdr.seq;
 124         int ret, ix;
 125         u8 annotation = RXRPC_TX_ANNO_UNACK;
 126
 127         _net("queue skb %p [%d]", skb, seq);
 128
 129         ASSERTCMP(seq, ==, call->tx_top + 1);
 130
 131         if (last) {
 132                 annotation |= RXRPC_TX_ANNO_LAST;
 133                 set_bit(RXRPC_CALL_TX_LASTQ, &call->flags);
 134         }
 135
 136         /* We have to set the timestamp before queueing as the retransmit
 137          * algorithm can see the packet as soon as we queue it.
 138          */
 139         skb->tstamp = ktime_get_real();
 140
 141         ix = seq & RXRPC_RXTX_BUFF_MASK;
 142         rxrpc_get_skb(skb, rxrpc_skb_tx_got);
 143         call->rxtx_annotations[ix] = annotation;
 144         smp_wmb();
 145         call->rxtx_buffer[ix] = skb;
 146         call->tx_top = seq;
 147         if (last)
 148                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 149         else
 150                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 151
 152         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 153                 _debug("________awaiting reply/ACK__________");
 154                 write_lock_bh(&call->state_lock);
 155                 switch (call->state) {
 156                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 157                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 158                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 159                         break;
 160                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 161                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 162                         call->ack_at = call->expire_at;
 163                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 164                                 call->ackr_reason = 0;
 165                         __rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,
 166                                           ktime_get_real());
 167                         if (!last)
 168                                 break;
 169                 case RXRPC_CALL_SERVER_SEND_REPLY:
 170                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 171                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 172                         break;
 173                 default:
 174                         break;
 175                 }
 176                 write_unlock_bh(&call->state_lock);
 177         }
 178
 179         if (seq == 1 && rxrpc_is_client_call(call))
 180                 rxrpc_expose_client_call(call);
 181
 182         ret = rxrpc_send_data_packet(call, skb, false);
 183         if (ret < 0) {
 184                 _debug("need instant resend %d", ret);
 185                 rxrpc_instant_resend(call, ix);
 186         } else {
 187                 ktime_t now = ktime_get_real(), resend_at;
 188
 189                 resend_at = ktime_add_ms(now, rxrpc_resend_timeout);
 190
 191                 if (ktime_before(resend_at, call->resend_at)) {
 192                         call->resend_at = resend_at;
 193                         rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);
 194                 }
 195         }
 196
 197         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 198         _leave("");
 199 }
 200
 201 /*
 202  * send data through a socket
 203  * - must be called in process context
 204  * - The caller holds the call user access mutex, but not the socket lock.
 205  */
 206 static int rxrpc_send_data(struct rxrpc_sock *rx,
 207                            struct rxrpc_call *call,
 208                            struct msghdr *msg, size_t len,
 209                            rxrpc_notify_end_tx_t notify_end_tx)
 210 {
 211         struct rxrpc_skb_priv *sp;
 212         struct sk_buff *skb;
 213         struct sock *sk = &rx->sk;
 214         long timeo;
 215         bool more;
 216         int ret, copied;
 217
 218         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 219
 220         /* this should be in poll */
 221         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 222
 223         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 224                 return -EPIPE;
 225
 226         more = msg->msg_flags & MSG_MORE;
 227
 228         if (call->tx_total_len != -1) {
 229                 if (len > call->tx_total_len)
 230                         return -EMSGSIZE;
 231                 if (!more && len != call->tx_total_len)
 232                         return -EMSGSIZE;
 233         }
 234
 235         skb = call->tx_pending;
 236         call->tx_pending = NULL;
 237         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 238
 239         copied = 0;
 240         do {
 241                 /* Check to see if there's a ping ACK to reply to. */
 242                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 243                         rxrpc_send_ack_packet(call, false);
 244
 245                 if (!skb) {
 246                         size_t size, chunk, max, space;
 247
 248                         _debug("alloc");
 249
 250                         if (call->tx_top - call->tx_hard_ack >=
 251                             min_t(unsigned int, call->tx_winsize,
 252                                   call->cong_cwnd + call->cong_extra)) {
 253                                 ret = -EAGAIN;
 254                                 if (msg->msg_flags & MSG_DONTWAIT)
 255                                         goto maybe_error;
 256                                 ret = rxrpc_wait_for_tx_window(rx, call,
 257                                                                &timeo);
 258                                 if (ret < 0)
 259                                         goto maybe_error;
 260                         }
 261
 262                         max = RXRPC_JUMBO_DATALEN;
 263                         max -= call->conn->security_size;
 264                         max &= ~(call->conn->size_align - 1UL);
 265
 266                         chunk = max;
 267                         if (chunk > msg_data_left(msg) && !more)
 268                                 chunk = msg_data_left(msg);
 269
 270                         space = chunk + call->conn->size_align;
 271                         space &= ~(call->conn->size_align - 1UL);
 272
 273                         size = space + call->conn->security_size;
 274
 275                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 276
 277                         /* create a buffer that we can retain until it's ACK'd */
 278                         skb = sock_alloc_send_skb(
 279                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 280                         if (!skb)
 281                                 goto maybe_error;
 282
 283                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 284
 285                         _debug("ALLOC SEND %p", skb);
 286
 287                         ASSERTCMP(skb->mark, ==, 0);
 288
 289                         _debug("HS: %u", call->conn->security_size);
 290                         skb_reserve(skb, call->conn->security_size);
 291                         skb->len += call->conn->security_size;
 292
 293                         sp = rxrpc_skb(skb);
 294                         sp->remain = chunk;
 295                         if (sp->remain > skb_tailroom(skb))
 296                                 sp->remain = skb_tailroom(skb);
 297
 298                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 299                                skb_headroom(skb),
 300                                skb_tailroom(skb),
 301                                skb_headlen(skb),
 302                                sp->remain);
 303
 304                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 305                 }
 306
 307                 _debug("append");
 308                 sp = rxrpc_skb(skb);
 309
 310                 /* append next segment of data to the current buffer */
 311                 if (msg_data_left(msg) > 0) {
 312                         int copy = skb_tailroom(skb);
 313                         ASSERTCMP(copy, >, 0);
 314                         if (copy > msg_data_left(msg))
 315                                 copy = msg_data_left(msg);
 316                         if (copy > sp->remain)
 317                                 copy = sp->remain;
 318
 319                         _debug("add");
 320                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 321                         _debug("added");
 322                         if (ret < 0)
 323                                 goto efault;
 324                         sp->remain -= copy;
 325                         skb->mark += copy;
 326                         copied += copy;
 327                         if (call->tx_total_len != -1)
 328                                 call->tx_total_len -= copy;
 329                 }
 330
 331                 /* add the packet to the send queue if it's now full */
 332                 if (sp->remain <= 0 ||
 333                     (msg_data_left(msg) == 0 && !more)) {
 334                         struct rxrpc_connection *conn = call->conn;
 335                         uint32_t seq;
 336                         size_t pad;
 337
 338                         /* pad out if we're using security */
 339                         if (conn->security_ix) {
 340                                 pad = conn->security_size + skb->mark;
 341                                 pad = conn->size_align - pad;
 342                                 pad &= conn->size_align - 1;
 343                                 _debug("pad %zu", pad);
 344                                 if (pad)
 345                                         skb_put_zero(skb, pad);
 346                         }
 347
 348                         seq = call->tx_top + 1;
 349
 350                         sp->hdr.seq     = seq;
 351                         sp->hdr._rsvd   = 0;
 352                         sp->hdr.flags   = conn->out_clientflag;
 353
 354                         if (msg_data_left(msg) == 0 && !more)
 355                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 356                         else if (call->tx_top - call->tx_hard_ack <
 357                                  call->tx_winsize)
 358                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 359
 360                         ret = conn->security->secure_packet(
 361                                 call, skb, skb->mark, skb->head);
 362                         if (ret < 0)
 363                                 goto out;
 364
 365                         rxrpc_queue_packet(rx, call, skb,
 366                                            !msg_data_left(msg) && !more,
 367                                            notify_end_tx);
 368                         skb = NULL;
 369                 }
 370
 371                 /* Check for the far side aborting the call or a network error
 372                  * occurring.  If this happens, save any packet that was under
 373                  * construction so that in the case of a network error, the
 374                  * call can be retried or redirected.
 375                  */
 376                 if (call->state == RXRPC_CALL_COMPLETE) {
 377                         ret = call->error;
 378                         goto out;
 379                 }
 380         } while (msg_data_left(msg) > 0);
 381
 382 success:
 383         ret = copied;
 384 out:
 385         call->tx_pending = skb;
 386         _leave(" = %d", ret);
 387         return ret;
 388
 389 maybe_error:
 390         if (copied)
 391                 goto success;
 392         goto out;
 393
 394 efault:
 395         ret = -EFAULT;
 396         goto out;
 397 }
 398
 399 /*
 400  * extract control messages from the sendmsg() control buffer
 401  */
 402 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 403 {
 404         struct cmsghdr *cmsg;
 405         bool got_user_ID = false;
 406         int len;
 407
 408         if (msg->msg_controllen == 0)
 409                 return -EINVAL;
 410
 411         for_each_cmsghdr(cmsg, msg) {
 412                 if (!CMSG_OK(msg, cmsg))
 413                         return -EINVAL;
 414
 415                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 416                 _debug("CMSG %d, %d, %d",
 417                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 418
 419                 if (cmsg->cmsg_level != SOL_RXRPC)
 420                         continue;
 421
 422                 switch (cmsg->cmsg_type) {
 423                 case RXRPC_USER_CALL_ID:
 424                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 425                                 if (len != sizeof(u32))
 426                                         return -EINVAL;
 427                                 p->user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 428                         } else {
 429                                 if (len != sizeof(unsigned long))
 430                                         return -EINVAL;
 431                                 p->user_call_ID = *(unsigned long *)
 432                                         CMSG_DATA(cmsg);
 433                         }
 434                         got_user_ID = true;
 435                         break;
 436
 437                 case RXRPC_ABORT:
 438                         if (p->command != RXRPC_CMD_SEND_DATA)
 439                                 return -EINVAL;
 440                         p->command = RXRPC_CMD_SEND_ABORT;
 441                         if (len != sizeof(p->abort_code))
 442                                 return -EINVAL;
 443                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 444                         if (p->abort_code == 0)
 445                                 return -EINVAL;
 446                         break;
 447
 448                 case RXRPC_ACCEPT:
 449                         if (p->command != RXRPC_CMD_SEND_DATA)
 450                                 return -EINVAL;
 451                         p->command = RXRPC_CMD_ACCEPT;
 452                         if (len != 0)
 453                                 return -EINVAL;
 454                         break;
 455
 456                 case RXRPC_EXCLUSIVE_CALL:
 457                         p->exclusive = true;
 458                         if (len != 0)
 459                                 return -EINVAL;
 460                         break;
 461
 462                 case RXRPC_UPGRADE_SERVICE:
 463                         p->upgrade = true;
 464                         if (len != 0)
 465                                 return -EINVAL;
 466                         break;
 467
 468                 case RXRPC_TX_LENGTH:
 469                         if (p->tx_total_len != -1 || len != sizeof(__s64))
 470                                 return -EINVAL;
 471                         p->tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 472                         if (p->tx_total_len < 0)
 473                                 return -EINVAL;
 474                         break;
 475
 476                 default:
 477                         return -EINVAL;
 478                 }
 479         }
 480
 481         if (!got_user_ID)
 482                 return -EINVAL;
 483         if (p->tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 484                 return -EINVAL;
 485         _leave(" = 0");
 486         return 0;
 487 }
 488
 489 /*
 490  * Create a new client call for sendmsg().
 491  * - Called with the socket lock held, which it must release.
 492  * - If it returns a call, the call's lock will need releasing by the caller.
 493  */
 494 static struct rxrpc_call *
 495 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 496                                   struct rxrpc_send_params *p)
 497         __releases(&rx->sk.sk_lock.slock)
 498 {
 499         struct rxrpc_conn_parameters cp;
 500         struct rxrpc_call *call;
 501         struct key *key;
 502
 503         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 504
 505         _enter("");
 506
 507         if (!msg->msg_name) {
 508                 release_sock(&rx->sk);
 509                 return ERR_PTR(-EDESTADDRREQ);
 510         }
 511
 512         key = rx->key;
 513         if (key && !rx->key->payload.data[0])
 514                 key = NULL;
 515
 516         memset(&cp, 0, sizeof(cp));
 517         cp.local                = rx->local;
 518         cp.key                  = rx->key;
 519         cp.security_level       = rx->min_sec_level;
 520         cp.exclusive            = rx->exclusive | p->exclusive;
 521         cp.upgrade              = p->upgrade;
 522         cp.service_id           = srx->srx_service;
 523         call = rxrpc_new_client_call(rx, &cp, srx, p->user_call_ID,
 524                                      p->tx_total_len, GFP_KERNEL);
 525         /* The socket is now unlocked */
 526
 527         _leave(" = %p\n", call);
 528         return call;
 529 }
 530
 531 /*
 532  * send a message forming part of a client call through an RxRPC socket
 533  * - caller holds the socket locked
 534  * - the socket may be either a client socket or a server socket
 535  */
 536 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 537         __releases(&rx->sk.sk_lock.slock)
 538 {
 539         enum rxrpc_call_state state;
 540         struct rxrpc_call *call;
 541         int ret;
 542
 543         struct rxrpc_send_params p = {
 544                 .tx_total_len   = -1,
 545                 .user_call_ID   = 0,
 546                 .abort_code     = 0,
 547                 .command        = RXRPC_CMD_SEND_DATA,
 548                 .exclusive      = false,
 549                 .upgrade        = true,
 550         };
 551
 552         _enter("");
 553
 554         ret = rxrpc_sendmsg_cmsg(msg, &p);
 555         if (ret < 0)
 556                 goto error_release_sock;
 557
 558         if (p.command == RXRPC_CMD_ACCEPT) {
 559                 ret = -EINVAL;
 560                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 561                         goto error_release_sock;
 562                 call = rxrpc_accept_call(rx, p.user_call_ID, NULL);
 563                 /* The socket is now unlocked. */
 564                 if (IS_ERR(call))
 565                         return PTR_ERR(call);
 566                 rxrpc_put_call(call, rxrpc_call_put);
 567                 return 0;
 568         }
 569
 570         call = rxrpc_find_call_by_user_ID(rx, p.user_call_ID);
 571         if (!call) {
 572                 ret = -EBADSLT;
 573                 if (p.command != RXRPC_CMD_SEND_DATA)
 574                         goto error_release_sock;
 575                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 576                 /* The socket is now unlocked... */
 577                 if (IS_ERR(call))
 578                         return PTR_ERR(call);
 579                 /* ... and we have the call lock. */
 580         } else {
 581                 switch (READ_ONCE(call->state)) {
 582                 case RXRPC_CALL_UNINITIALISED:
 583                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 584                 case RXRPC_CALL_SERVER_PREALLOC:
 585                 case RXRPC_CALL_SERVER_SECURING:
 586                 case RXRPC_CALL_SERVER_ACCEPTING:
 587                         ret = -EBUSY;
 588                         goto error_release_sock;
 589                 default:
 590                         break;
 591                 }
 592
 593                 ret = mutex_lock_interruptible(&call->user_mutex);
 594                 release_sock(&rx->sk);
 595                 if (ret < 0) {
 596                         ret = -ERESTARTSYS;
 597                         goto error_put;
 598                 }
 599
 600                 if (p.tx_total_len != -1) {
 601                         ret = -EINVAL;
 602                         if (call->tx_total_len != -1 ||
 603                             call->tx_pending ||
 604                             call->tx_top != 0)
 605                                 goto error_put;
 606                         call->tx_total_len = p.tx_total_len;
 607                 }
 608         }
 609
 610         state = READ_ONCE(call->state);
 611         _debug("CALL %d USR %lx ST %d on CONN %p",
 612                call->debug_id, call->user_call_ID, state, call->conn);
 613
 614         if (state >= RXRPC_CALL_COMPLETE) {
 615                 /* it's too late for this call */
 616                 ret = -ESHUTDOWN;
 617         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 618                 ret = 0;
 619                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 620                         ret = rxrpc_send_abort_packet(call);
 621         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 622                 ret = -EINVAL;
 623         } else if (rxrpc_is_client_call(call) &&
 624                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 625                 /* request phase complete for this client call */
 626                 ret = -EPROTO;
 627         } else if (rxrpc_is_service_call(call) &&
 628                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 629                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 630                 /* Reply phase not begun or not complete for service call. */
 631                 ret = -EPROTO;
 632         } else {
 633                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 634         }
 635
 636         mutex_unlock(&call->user_mutex);
 637 error_put:
 638         rxrpc_put_call(call, rxrpc_call_put);
 639         _leave(" = %d", ret);
 640         return ret;
 641
 642 error_release_sock:
 643         release_sock(&rx->sk);
 644         return ret;
 645 }
 646
 647 /**
 648  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 649  * @sock: The socket the call is on
 650  * @call: The call to send data through
 651  * @msg: The data to send
 652  * @len: The amount of data to send
 653  * @notify_end_tx: Notification that the last packet is queued.
 654  *
 655  * Allow a kernel service to send data on a call.  The call must be in an state
 656  * appropriate to sending data.  No control data should be supplied in @msg,
 657  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 658  * more data to come, otherwise this data will end the transmission phase.
 659  */
 660 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 661                            struct msghdr *msg, size_t len,
 662                            rxrpc_notify_end_tx_t notify_end_tx)
 663 {
 664         int ret;
 665
 666         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 667
 668         ASSERTCMP(msg->msg_name, ==, NULL);
 669         ASSERTCMP(msg->msg_control, ==, NULL);
 670
 671         mutex_lock(&call->user_mutex);
 672
 673         _debug("CALL %d USR %lx ST %d on CONN %p",
 674                call->debug_id, call->user_call_ID, call->state, call->conn);
 675
 676         switch (READ_ONCE(call->state)) {
 677         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 678         case RXRPC_CALL_SERVER_ACK_REQUEST:
 679         case RXRPC_CALL_SERVER_SEND_REPLY:
 680                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 681                                       notify_end_tx);
 682                 break;
 683         case RXRPC_CALL_COMPLETE:
 684                 read_lock_bh(&call->state_lock);
 685                 ret = call->error;
 686                 read_unlock_bh(&call->state_lock);
 687                 break;
 688         default:
 689                 /* Request phase complete for this client call */
 690                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 691                 ret = -EPROTO;
 692                 break;
 693         }
 694
 695         mutex_unlock(&call->user_mutex);
 696         _leave(" = %d", ret);
 697         return ret;
 698 }
 699 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 700
 701 /**
 702  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 703  * @sock: The socket the call is on
 704  * @call: The call to be aborted
 705  * @abort_code: The abort code to stick into the ABORT packet
 706  * @error: Local error value
 707  * @why: 3-char string indicating why.
 708  *
 709  * Allow a kernel service to abort a call, if it's still in an abortable state
 710  * and return true if the call was aborted, false if it was already complete.
 711  */
 712 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 713                              u32 abort_code, int error, const char *why)
 714 {
 715         bool aborted;
 716
 717         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 718
 719         mutex_lock(&call->user_mutex);
 720
 721         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 722         if (aborted)
 723                 rxrpc_send_abort_packet(call);
 724
 725         mutex_unlock(&call->user_mutex);
 726         return aborted;
 727 }
 728 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 729
 730 /**
 731  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 732  * @sock: The socket the call is on
 733  * @call: The call to be informed
 734  * @tx_total_len: The amount of data to be transmitted for this call
 735  *
 736  * Allow a kernel service to set the total transmit length on a call.  This
 737  * allows buffer-to-packet encrypt-and-copy to be performed.
 738  *
 739  * This function is primarily for use for setting the reply length since the
 740  * request length can be set when beginning the call.
 741  */
 742 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 743                                 s64 tx_total_len)
 744 {
 745         WARN_ON(call->tx_total_len != -1);
 746         call->tx_total_len = tx_total_len;
 747 }
 748 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);