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] =
  96                         (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
  97                         RXRPC_TX_ANNO_RETRANS;
  98                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
  99                         rxrpc_queue_call(call);
 100         }
 101
 102         spin_unlock_bh(&call->lock);
 103 }
 104
 105 /*
 106  * Notify the owner of the call that the transmit phase is ended and the last
 107  * packet has been queued.
 108  */
 109 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 110                                 rxrpc_notify_end_tx_t notify_end_tx)
 111 {
 112         if (notify_end_tx)
 113                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 114 }
 115
 116 /*
 117  * Queue a DATA packet for transmission, set the resend timeout and send the
 118  * packet immediately
 119  */
 120 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 121                                struct sk_buff *skb, bool last,
 122                                rxrpc_notify_end_tx_t notify_end_tx)
 123 {
 124         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 125         rxrpc_seq_t seq = sp->hdr.seq;
 126         int ret, ix;
 127         u8 annotation = RXRPC_TX_ANNO_UNACK;
 128
 129         _net("queue skb %p [%d]", skb, seq);
 130
 131         ASSERTCMP(seq, ==, call->tx_top + 1);
 132
 133         if (last) {
 134                 annotation |= RXRPC_TX_ANNO_LAST;
 135                 set_bit(RXRPC_CALL_TX_LASTQ, &call->flags);
 136         }
 137
 138         /* We have to set the timestamp before queueing as the retransmit
 139          * algorithm can see the packet as soon as we queue it.
 140          */
 141         skb->tstamp = ktime_get_real();
 142
 143         ix = seq & RXRPC_RXTX_BUFF_MASK;
 144         rxrpc_get_skb(skb, rxrpc_skb_tx_got);
 145         call->rxtx_annotations[ix] = annotation;
 146         smp_wmb();
 147         call->rxtx_buffer[ix] = skb;
 148         call->tx_top = seq;
 149         if (last)
 150                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 151         else
 152                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 153
 154         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 155                 _debug("________awaiting reply/ACK__________");
 156                 write_lock_bh(&call->state_lock);
 157                 switch (call->state) {
 158                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 159                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 160                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 161                         break;
 162                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 163                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 164                         call->ack_at = call->expire_at;
 165                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 166                                 call->ackr_reason = 0;
 167                         __rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,
 168                                           ktime_get_real());
 169                         if (!last)
 170                                 break;
 171                 case RXRPC_CALL_SERVER_SEND_REPLY:
 172                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 173                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 174                         break;
 175                 default:
 176                         break;
 177                 }
 178                 write_unlock_bh(&call->state_lock);
 179         }
 180
 181         if (seq == 1 && rxrpc_is_client_call(call))
 182                 rxrpc_expose_client_call(call);
 183
 184         ret = rxrpc_send_data_packet(call, skb, false);
 185         if (ret < 0) {
 186                 _debug("need instant resend %d", ret);
 187                 rxrpc_instant_resend(call, ix);
 188         } else {
 189                 ktime_t now = ktime_get_real(), resend_at;
 190
 191                 resend_at = ktime_add_ms(now, rxrpc_resend_timeout);
 192
 193                 if (ktime_before(resend_at, call->resend_at)) {
 194                         call->resend_at = resend_at;
 195                         rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);
 196                 }
 197         }
 198
 199         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 200         _leave("");
 201 }
 202
 203 /*
 204  * send data through a socket
 205  * - must be called in process context
 206  * - The caller holds the call user access mutex, but not the socket lock.
 207  */
 208 static int rxrpc_send_data(struct rxrpc_sock *rx,
 209                            struct rxrpc_call *call,
 210                            struct msghdr *msg, size_t len,
 211                            rxrpc_notify_end_tx_t notify_end_tx)
 212 {
 213         struct rxrpc_skb_priv *sp;
 214         struct sk_buff *skb;
 215         struct sock *sk = &rx->sk;
 216         long timeo;
 217         bool more;
 218         int ret, copied;
 219
 220         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 221
 222         /* this should be in poll */
 223         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 224
 225         if (sk->sk_shutdown & SEND_SHUTDOWN)
 226                 return -EPIPE;
 227
 228         more = msg->msg_flags & MSG_MORE;
 229
 230         if (call->tx_total_len != -1) {
 231                 if (len > call->tx_total_len)
 232                         return -EMSGSIZE;
 233                 if (!more && len != call->tx_total_len)
 234                         return -EMSGSIZE;
 235         }
 236
 237         skb = call->tx_pending;
 238         call->tx_pending = NULL;
 239         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 240
 241         copied = 0;
 242         do {
 243                 /* Check to see if there's a ping ACK to reply to. */
 244                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 245                         rxrpc_send_ack_packet(call, false);
 246
 247                 if (!skb) {
 248                         size_t size, chunk, max, space;
 249
 250                         _debug("alloc");
 251
 252                         if (call->tx_top - call->tx_hard_ack >=
 253                             min_t(unsigned int, call->tx_winsize,
 254                                   call->cong_cwnd + call->cong_extra)) {
 255                                 ret = -EAGAIN;
 256                                 if (msg->msg_flags & MSG_DONTWAIT)
 257                                         goto maybe_error;
 258                                 ret = rxrpc_wait_for_tx_window(rx, call,
 259                                                                &timeo);
 260                                 if (ret < 0)
 261                                         goto maybe_error;
 262                         }
 263
 264                         max = RXRPC_JUMBO_DATALEN;
 265                         max -= call->conn->security_size;
 266                         max &= ~(call->conn->size_align - 1UL);
 267
 268                         chunk = max;
 269                         if (chunk > msg_data_left(msg) && !more)
 270                                 chunk = msg_data_left(msg);
 271
 272                         space = chunk + call->conn->size_align;
 273                         space &= ~(call->conn->size_align - 1UL);
 274
 275                         size = space + call->conn->security_size;
 276
 277                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 278
 279                         /* create a buffer that we can retain until it's ACK'd */
 280                         skb = sock_alloc_send_skb(
 281                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 282                         if (!skb)
 283                                 goto maybe_error;
 284
 285                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 286
 287                         _debug("ALLOC SEND %p", skb);
 288
 289                         ASSERTCMP(skb->mark, ==, 0);
 290
 291                         _debug("HS: %u", call->conn->security_size);
 292                         skb_reserve(skb, call->conn->security_size);
 293                         skb->len += call->conn->security_size;
 294
 295                         sp = rxrpc_skb(skb);
 296                         sp->remain = chunk;
 297                         if (sp->remain > skb_tailroom(skb))
 298                                 sp->remain = skb_tailroom(skb);
 299
 300                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 301                                skb_headroom(skb),
 302                                skb_tailroom(skb),
 303                                skb_headlen(skb),
 304                                sp->remain);
 305
 306                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 307                 }
 308
 309                 _debug("append");
 310                 sp = rxrpc_skb(skb);
 311
 312                 /* append next segment of data to the current buffer */
 313                 if (msg_data_left(msg) > 0) {
 314                         int copy = skb_tailroom(skb);
 315                         ASSERTCMP(copy, >, 0);
 316                         if (copy > msg_data_left(msg))
 317                                 copy = msg_data_left(msg);
 318                         if (copy > sp->remain)
 319                                 copy = sp->remain;
 320
 321                         _debug("add");
 322                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 323                         _debug("added");
 324                         if (ret < 0)
 325                                 goto efault;
 326                         sp->remain -= copy;
 327                         skb->mark += copy;
 328                         copied += copy;
 329                         if (call->tx_total_len != -1)
 330                                 call->tx_total_len -= copy;
 331                 }
 332
 333                 /* add the packet to the send queue if it's now full */
 334                 if (sp->remain <= 0 ||
 335                     (msg_data_left(msg) == 0 && !more)) {
 336                         struct rxrpc_connection *conn = call->conn;
 337                         uint32_t seq;
 338                         size_t pad;
 339
 340                         /* pad out if we're using security */
 341                         if (conn->security_ix) {
 342                                 pad = conn->security_size + skb->mark;
 343                                 pad = conn->size_align - pad;
 344                                 pad &= conn->size_align - 1;
 345                                 _debug("pad %zu", pad);
 346                                 if (pad)
 347                                         skb_put_zero(skb, pad);
 348                         }
 349
 350                         seq = call->tx_top + 1;
 351
 352                         sp->hdr.seq     = seq;
 353                         sp->hdr._rsvd   = 0;
 354                         sp->hdr.flags   = conn->out_clientflag;
 355
 356                         if (msg_data_left(msg) == 0 && !more)
 357                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 358                         else if (call->tx_top - call->tx_hard_ack <
 359                                  call->tx_winsize)
 360                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 361
 362                         ret = conn->security->secure_packet(
 363                                 call, skb, skb->mark, skb->head);
 364                         if (ret < 0)
 365                                 goto out;
 366
 367                         rxrpc_queue_packet(rx, call, skb,
 368                                            !msg_data_left(msg) && !more,
 369                                            notify_end_tx);
 370                         skb = NULL;
 371                 }
 372
 373                 /* Check for the far side aborting the call or a network error
 374                  * occurring.  If this happens, save any packet that was under
 375                  * construction so that in the case of a network error, the
 376                  * call can be retried or redirected.
 377                  */
 378                 if (call->state == RXRPC_CALL_COMPLETE) {
 379                         ret = call->error;
 380                         goto out;
 381                 }
 382         } while (msg_data_left(msg) > 0);
 383
 384 success:
 385         ret = copied;
 386         if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
 387                 read_lock_bh(&call->state_lock);
 388                 if (call->error < 0)
 389                         ret = call->error;
 390                 read_unlock_bh(&call->state_lock);
 391         }
 392 out:
 393         call->tx_pending = skb;
 394         _leave(" = %d", ret);
 395         return ret;
 396
 397 maybe_error:
 398         if (copied)
 399                 goto success;
 400         goto out;
 401
 402 efault:
 403         ret = -EFAULT;
 404         goto out;
 405 }
 406
 407 /*
 408  * extract control messages from the sendmsg() control buffer
 409  */
 410 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 411 {
 412         struct cmsghdr *cmsg;
 413         bool got_user_ID = false;
 414         int len;
 415
 416         if (msg->msg_controllen == 0)
 417                 return -EINVAL;
 418
 419         for_each_cmsghdr(cmsg, msg) {
 420                 if (!CMSG_OK(msg, cmsg))
 421                         return -EINVAL;
 422
 423                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 424                 _debug("CMSG %d, %d, %d",
 425                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 426
 427                 if (cmsg->cmsg_level != SOL_RXRPC)
 428                         continue;
 429
 430                 switch (cmsg->cmsg_type) {
 431                 case RXRPC_USER_CALL_ID:
 432                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 433                                 if (len != sizeof(u32))
 434                                         return -EINVAL;
 435                                 p->user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 436                         } else {
 437                                 if (len != sizeof(unsigned long))
 438                                         return -EINVAL;
 439                                 p->user_call_ID = *(unsigned long *)
 440                                         CMSG_DATA(cmsg);
 441                         }
 442                         got_user_ID = true;
 443                         break;
 444
 445                 case RXRPC_ABORT:
 446                         if (p->command != RXRPC_CMD_SEND_DATA)
 447                                 return -EINVAL;
 448                         p->command = RXRPC_CMD_SEND_ABORT;
 449                         if (len != sizeof(p->abort_code))
 450                                 return -EINVAL;
 451                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 452                         if (p->abort_code == 0)
 453                                 return -EINVAL;
 454                         break;
 455
 456                 case RXRPC_ACCEPT:
 457                         if (p->command != RXRPC_CMD_SEND_DATA)
 458                                 return -EINVAL;
 459                         p->command = RXRPC_CMD_ACCEPT;
 460                         if (len != 0)
 461                                 return -EINVAL;
 462                         break;
 463
 464                 case RXRPC_EXCLUSIVE_CALL:
 465                         p->exclusive = true;
 466                         if (len != 0)
 467                                 return -EINVAL;
 468                         break;
 469
 470                 case RXRPC_UPGRADE_SERVICE:
 471                         p->upgrade = true;
 472                         if (len != 0)
 473                                 return -EINVAL;
 474                         break;
 475
 476                 case RXRPC_TX_LENGTH:
 477                         if (p->tx_total_len != -1 || len != sizeof(__s64))
 478                                 return -EINVAL;
 479                         p->tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 480                         if (p->tx_total_len < 0)
 481                                 return -EINVAL;
 482                         break;
 483
 484                 default:
 485                         return -EINVAL;
 486                 }
 487         }
 488
 489         if (!got_user_ID)
 490                 return -EINVAL;
 491         if (p->tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 492                 return -EINVAL;
 493         _leave(" = 0");
 494         return 0;
 495 }
 496
 497 /*
 498  * Create a new client call for sendmsg().
 499  * - Called with the socket lock held, which it must release.
 500  * - If it returns a call, the call's lock will need releasing by the caller.
 501  */
 502 static struct rxrpc_call *
 503 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 504                                   struct rxrpc_send_params *p)
 505         __releases(&rx->sk.sk_lock.slock)
 506 {
 507         struct rxrpc_conn_parameters cp;
 508         struct rxrpc_call *call;
 509         struct key *key;
 510
 511         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 512
 513         _enter("");
 514
 515         if (!msg->msg_name) {
 516                 release_sock(&rx->sk);
 517                 return ERR_PTR(-EDESTADDRREQ);
 518         }
 519
 520         key = rx->key;
 521         if (key && !rx->key->payload.data[0])
 522                 key = NULL;
 523
 524         memset(&cp, 0, sizeof(cp));
 525         cp.local                = rx->local;
 526         cp.key                  = rx->key;
 527         cp.security_level       = rx->min_sec_level;
 528         cp.exclusive            = rx->exclusive | p->exclusive;
 529         cp.upgrade              = p->upgrade;
 530         cp.service_id           = srx->srx_service;
 531         call = rxrpc_new_client_call(rx, &cp, srx, p->user_call_ID,
 532                                      p->tx_total_len, GFP_KERNEL);
 533         /* The socket is now unlocked */
 534
 535         _leave(" = %p\n", call);
 536         return call;
 537 }
 538
 539 /*
 540  * send a message forming part of a client call through an RxRPC socket
 541  * - caller holds the socket locked
 542  * - the socket may be either a client socket or a server socket
 543  */
 544 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 545         __releases(&rx->sk.sk_lock.slock)
 546 {
 547         enum rxrpc_call_state state;
 548         struct rxrpc_call *call;
 549         int ret;
 550
 551         struct rxrpc_send_params p = {
 552                 .tx_total_len   = -1,
 553                 .user_call_ID   = 0,
 554                 .abort_code     = 0,
 555                 .command        = RXRPC_CMD_SEND_DATA,
 556                 .exclusive      = false,
 557                 .upgrade        = true,
 558         };
 559
 560         _enter("");
 561
 562         ret = rxrpc_sendmsg_cmsg(msg, &p);
 563         if (ret < 0)
 564                 goto error_release_sock;
 565
 566         if (p.command == RXRPC_CMD_ACCEPT) {
 567                 ret = -EINVAL;
 568                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 569                         goto error_release_sock;
 570                 call = rxrpc_accept_call(rx, p.user_call_ID, NULL);
 571                 /* The socket is now unlocked. */
 572                 if (IS_ERR(call))
 573                         return PTR_ERR(call);
 574                 ret = 0;
 575                 goto out_put_unlock;
 576         }
 577
 578         call = rxrpc_find_call_by_user_ID(rx, p.user_call_ID);
 579         if (!call) {
 580                 ret = -EBADSLT;
 581                 if (p.command != RXRPC_CMD_SEND_DATA)
 582                         goto error_release_sock;
 583                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 584                 /* The socket is now unlocked... */
 585                 if (IS_ERR(call))
 586                         return PTR_ERR(call);
 587                 /* ... and we have the call lock. */
 588                 ret = 0;
 589                 if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
 590                         goto out_put_unlock;
 591         } else {
 592                 switch (READ_ONCE(call->state)) {
 593                 case RXRPC_CALL_UNINITIALISED:
 594                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 595                 case RXRPC_CALL_SERVER_PREALLOC:
 596                 case RXRPC_CALL_SERVER_SECURING:
 597                 case RXRPC_CALL_SERVER_ACCEPTING:
 598                         rxrpc_put_call(call, rxrpc_call_put);
 599                         ret = -EBUSY;
 600                         goto error_release_sock;
 601                 default:
 602                         break;
 603                 }
 604
 605                 ret = mutex_lock_interruptible(&call->user_mutex);
 606                 release_sock(&rx->sk);
 607                 if (ret < 0) {
 608                         ret = -ERESTARTSYS;
 609                         goto error_put;
 610                 }
 611
 612                 if (p.tx_total_len != -1) {
 613                         ret = -EINVAL;
 614                         if (call->tx_total_len != -1 ||
 615                             call->tx_pending ||
 616                             call->tx_top != 0)
 617                                 goto error_put;
 618                         call->tx_total_len = p.tx_total_len;
 619                 }
 620         }
 621
 622         state = READ_ONCE(call->state);
 623         _debug("CALL %d USR %lx ST %d on CONN %p",
 624                call->debug_id, call->user_call_ID, state, call->conn);
 625
 626         if (state >= RXRPC_CALL_COMPLETE) {
 627                 /* it's too late for this call */
 628                 ret = -ESHUTDOWN;
 629         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 630                 ret = 0;
 631                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 632                         ret = rxrpc_send_abort_packet(call);
 633         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 634                 ret = -EINVAL;
 635         } else if (rxrpc_is_client_call(call) &&
 636                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 637                 /* request phase complete for this client call */
 638                 ret = -EPROTO;
 639         } else if (rxrpc_is_service_call(call) &&
 640                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 641                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 642                 /* Reply phase not begun or not complete for service call. */
 643                 ret = -EPROTO;
 644         } else {
 645                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 646         }
 647
 648 out_put_unlock:
 649         mutex_unlock(&call->user_mutex);
 650 error_put:
 651         rxrpc_put_call(call, rxrpc_call_put);
 652         _leave(" = %d", ret);
 653         return ret;
 654
 655 error_release_sock:
 656         release_sock(&rx->sk);
 657         return ret;
 658 }
 659
 660 /**
 661  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 662  * @sock: The socket the call is on
 663  * @call: The call to send data through
 664  * @msg: The data to send
 665  * @len: The amount of data to send
 666  * @notify_end_tx: Notification that the last packet is queued.
 667  *
 668  * Allow a kernel service to send data on a call.  The call must be in an state
 669  * appropriate to sending data.  No control data should be supplied in @msg,
 670  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 671  * more data to come, otherwise this data will end the transmission phase.
 672  */
 673 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 674                            struct msghdr *msg, size_t len,
 675                            rxrpc_notify_end_tx_t notify_end_tx)
 676 {
 677         int ret;
 678
 679         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 680
 681         ASSERTCMP(msg->msg_name, ==, NULL);
 682         ASSERTCMP(msg->msg_control, ==, NULL);
 683
 684         mutex_lock(&call->user_mutex);
 685
 686         _debug("CALL %d USR %lx ST %d on CONN %p",
 687                call->debug_id, call->user_call_ID, call->state, call->conn);
 688
 689         switch (READ_ONCE(call->state)) {
 690         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 691         case RXRPC_CALL_SERVER_ACK_REQUEST:
 692         case RXRPC_CALL_SERVER_SEND_REPLY:
 693                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 694                                       notify_end_tx);
 695                 break;
 696         case RXRPC_CALL_COMPLETE:
 697                 read_lock_bh(&call->state_lock);
 698                 ret = call->error;
 699                 read_unlock_bh(&call->state_lock);
 700                 break;
 701         default:
 702                 /* Request phase complete for this client call */
 703                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 704                 ret = -EPROTO;
 705                 break;
 706         }
 707
 708         mutex_unlock(&call->user_mutex);
 709         _leave(" = %d", ret);
 710         return ret;
 711 }
 712 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 713
 714 /**
 715  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 716  * @sock: The socket the call is on
 717  * @call: The call to be aborted
 718  * @abort_code: The abort code to stick into the ABORT packet
 719  * @error: Local error value
 720  * @why: 3-char string indicating why.
 721  *
 722  * Allow a kernel service to abort a call, if it's still in an abortable state
 723  * and return true if the call was aborted, false if it was already complete.
 724  */
 725 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 726                              u32 abort_code, int error, const char *why)
 727 {
 728         bool aborted;
 729
 730         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 731
 732         mutex_lock(&call->user_mutex);
 733
 734         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 735         if (aborted)
 736                 rxrpc_send_abort_packet(call);
 737
 738         mutex_unlock(&call->user_mutex);
 739         return aborted;
 740 }
 741 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 742
 743 /**
 744  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 745  * @sock: The socket the call is on
 746  * @call: The call to be informed
 747  * @tx_total_len: The amount of data to be transmitted for this call
 748  *
 749  * Allow a kernel service to set the total transmit length on a call.  This
 750  * allows buffer-to-packet encrypt-and-copy to be performed.
 751  *
 752  * This function is primarily for use for setting the reply length since the
 753  * request length can be set when beginning the call.
 754  */
 755 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 756                                 s64 tx_total_len)
 757 {
 758         WARN_ON(call->tx_total_len != -1);
 759         call->tx_total_len = tx_total_len;
 760 }
 761 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);