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