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 Tx queue or a signal to occur.
  42  */
  43 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
  44                                          struct rxrpc_call *call,
  45                                          long *timeo)
  46 {
  47         for (;;) {
  48                 set_current_state(TASK_INTERRUPTIBLE);
  49                 if (call->tx_top - call->tx_hard_ack <
  50                     min_t(unsigned int, call->tx_winsize,
  51                           call->cong_cwnd + call->cong_extra))
  52                         return 0;
  53
  54                 if (call->state >= RXRPC_CALL_COMPLETE)
  55                         return call->error;
  56
  57                 if (signal_pending(current))
  58                         return sock_intr_errno(*timeo);
  59
  60                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  61                 mutex_unlock(&call->user_mutex);
  62                 *timeo = schedule_timeout(*timeo);
  63                 if (mutex_lock_interruptible(&call->user_mutex) < 0)
  64                         return sock_intr_errno(*timeo);
  65         }
  66 }
  67
  68 /*
  69  * Wait for space to appear in the Tx queue uninterruptibly, but with
  70  * a timeout of 2*RTT if no progress was made and a signal occurred.
  71  */
  72 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
  73                                             struct rxrpc_call *call)
  74 {
  75         rxrpc_seq_t tx_start, tx_win;
  76         signed long rtt2, timeout;
  77         u64 rtt;
  78
  79         rtt = READ_ONCE(call->peer->rtt);
  80         rtt2 = nsecs_to_jiffies64(rtt) * 2;
  81         if (rtt2 < 1)
  82                 rtt2 = 1;
  83
  84         timeout = rtt2;
  85         tx_start = READ_ONCE(call->tx_hard_ack);
  86
  87         for (;;) {
  88                 set_current_state(TASK_UNINTERRUPTIBLE);
  89
  90                 tx_win = READ_ONCE(call->tx_hard_ack);
  91                 if (call->tx_top - tx_win <
  92                     min_t(unsigned int, call->tx_winsize,
  93                           call->cong_cwnd + call->cong_extra))
  94                         return 0;
  95
  96                 if (call->state >= RXRPC_CALL_COMPLETE)
  97                         return call->error;
  98
  99                 if (timeout == 0 &&
 100                     tx_win == tx_start && signal_pending(current))
 101                         return -EINTR;
 102
 103                 if (tx_win != tx_start) {
 104                         timeout = rtt2;
 105                         tx_start = tx_win;
 106                 }
 107
 108                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
 109                 timeout = schedule_timeout(timeout);
 110         }
 111 }
 112
 113 /*
 114  * wait for space to appear in the transmit/ACK window
 115  * - caller holds the socket locked
 116  */
 117 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 118                                     struct rxrpc_call *call,
 119                                     long *timeo,
 120                                     bool waitall)
 121 {
 122         DECLARE_WAITQUEUE(myself, current);
 123         int ret;
 124
 125         _enter(",{%u,%u,%u}",
 126                call->tx_hard_ack, call->tx_top, call->tx_winsize);
 127
 128         add_wait_queue(&call->waitq, &myself);
 129
 130         if (waitall)
 131                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
 132         else
 133                 ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 134
 135         remove_wait_queue(&call->waitq, &myself);
 136         set_current_state(TASK_RUNNING);
 137         _leave(" = %d", ret);
 138         return ret;
 139 }
 140
 141 /*
 142  * Schedule an instant Tx resend.
 143  */
 144 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
 145 {
 146         spin_lock_bh(&call->lock);
 147
 148         if (call->state < RXRPC_CALL_COMPLETE) {
 149                 call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
 150                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
 151                         rxrpc_queue_call(call);
 152         }
 153
 154         spin_unlock_bh(&call->lock);
 155 }
 156
 157 /*
 158  * Notify the owner of the call that the transmit phase is ended and the last
 159  * packet has been queued.
 160  */
 161 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 162                                 rxrpc_notify_end_tx_t notify_end_tx)
 163 {
 164         if (notify_end_tx)
 165                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 166 }
 167
 168 /*
 169  * Queue a DATA packet for transmission, set the resend timeout and send the
 170  * packet immediately
 171  */
 172 static void rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 173                                struct sk_buff *skb, bool last,
 174                                rxrpc_notify_end_tx_t notify_end_tx)
 175 {
 176         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 177         rxrpc_seq_t seq = sp->hdr.seq;
 178         int ret, ix;
 179         u8 annotation = RXRPC_TX_ANNO_UNACK;
 180
 181         _net("queue skb %p [%d]", skb, seq);
 182
 183         ASSERTCMP(seq, ==, call->tx_top + 1);
 184
 185         if (last) {
 186                 annotation |= RXRPC_TX_ANNO_LAST;
 187                 set_bit(RXRPC_CALL_TX_LASTQ, &call->flags);
 188         }
 189
 190         /* We have to set the timestamp before queueing as the retransmit
 191          * algorithm can see the packet as soon as we queue it.
 192          */
 193         skb->tstamp = ktime_get_real();
 194
 195         ix = seq & RXRPC_RXTX_BUFF_MASK;
 196         rxrpc_get_skb(skb, rxrpc_skb_tx_got);
 197         call->rxtx_annotations[ix] = annotation;
 198         smp_wmb();
 199         call->rxtx_buffer[ix] = skb;
 200         call->tx_top = seq;
 201         if (last)
 202                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 203         else
 204                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 205
 206         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 207                 _debug("________awaiting reply/ACK__________");
 208                 write_lock_bh(&call->state_lock);
 209                 switch (call->state) {
 210                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 211                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 212                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 213                         break;
 214                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 215                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 216                         call->ack_at = call->expire_at;
 217                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 218                                 call->ackr_reason = 0;
 219                         __rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,
 220                                           ktime_get_real());
 221                         if (!last)
 222                                 break;
 223                         /* Fall through */
 224                 case RXRPC_CALL_SERVER_SEND_REPLY:
 225                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 226                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 227                         break;
 228                 default:
 229                         break;
 230                 }
 231                 write_unlock_bh(&call->state_lock);
 232         }
 233
 234         if (seq == 1 && rxrpc_is_client_call(call))
 235                 rxrpc_expose_client_call(call);
 236
 237         ret = rxrpc_send_data_packet(call, skb, false);
 238         if (ret < 0) {
 239                 _debug("need instant resend %d", ret);
 240                 rxrpc_instant_resend(call, ix);
 241         } else {
 242                 ktime_t now = ktime_get_real(), resend_at;
 243
 244                 resend_at = ktime_add_ms(now, rxrpc_resend_timeout);
 245
 246                 if (ktime_before(resend_at, call->resend_at)) {
 247                         call->resend_at = resend_at;
 248                         rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);
 249                 }
 250         }
 251
 252         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 253         _leave("");
 254 }
 255
 256 /*
 257  * send data through a socket
 258  * - must be called in process context
 259  * - The caller holds the call user access mutex, but not the socket lock.
 260  */
 261 static int rxrpc_send_data(struct rxrpc_sock *rx,
 262                            struct rxrpc_call *call,
 263                            struct msghdr *msg, size_t len,
 264                            rxrpc_notify_end_tx_t notify_end_tx)
 265 {
 266         struct rxrpc_skb_priv *sp;
 267         struct sk_buff *skb;
 268         struct sock *sk = &rx->sk;
 269         long timeo;
 270         bool more;
 271         int ret, copied;
 272
 273         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 274
 275         /* this should be in poll */
 276         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 277
 278         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 279                 return -EPIPE;
 280
 281         more = msg->msg_flags & MSG_MORE;
 282
 283         if (call->tx_total_len != -1) {
 284                 if (len > call->tx_total_len)
 285                         return -EMSGSIZE;
 286                 if (!more && len != call->tx_total_len)
 287                         return -EMSGSIZE;
 288         }
 289
 290         skb = call->tx_pending;
 291         call->tx_pending = NULL;
 292         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 293
 294         copied = 0;
 295         do {
 296                 /* Check to see if there's a ping ACK to reply to. */
 297                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 298                         rxrpc_send_ack_packet(call, false);
 299
 300                 if (!skb) {
 301                         size_t size, chunk, max, space;
 302
 303                         _debug("alloc");
 304
 305                         if (call->tx_top - call->tx_hard_ack >=
 306                             min_t(unsigned int, call->tx_winsize,
 307                                   call->cong_cwnd + call->cong_extra)) {
 308                                 ret = -EAGAIN;
 309                                 if (msg->msg_flags & MSG_DONTWAIT)
 310                                         goto maybe_error;
 311                                 ret = rxrpc_wait_for_tx_window(rx, call,
 312                                                                &timeo,
 313                                                                msg->msg_flags & MSG_WAITALL);
 314                                 if (ret < 0)
 315                                         goto maybe_error;
 316                         }
 317
 318                         max = RXRPC_JUMBO_DATALEN;
 319                         max -= call->conn->security_size;
 320                         max &= ~(call->conn->size_align - 1UL);
 321
 322                         chunk = max;
 323                         if (chunk > msg_data_left(msg) && !more)
 324                                 chunk = msg_data_left(msg);
 325
 326                         space = chunk + call->conn->size_align;
 327                         space &= ~(call->conn->size_align - 1UL);
 328
 329                         size = space + call->conn->security_size;
 330
 331                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 332
 333                         /* create a buffer that we can retain until it's ACK'd */
 334                         skb = sock_alloc_send_skb(
 335                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 336                         if (!skb)
 337                                 goto maybe_error;
 338
 339                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 340
 341                         _debug("ALLOC SEND %p", skb);
 342
 343                         ASSERTCMP(skb->mark, ==, 0);
 344
 345                         _debug("HS: %u", call->conn->security_size);
 346                         skb_reserve(skb, call->conn->security_size);
 347                         skb->len += call->conn->security_size;
 348
 349                         sp = rxrpc_skb(skb);
 350                         sp->remain = chunk;
 351                         if (sp->remain > skb_tailroom(skb))
 352                                 sp->remain = skb_tailroom(skb);
 353
 354                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 355                                skb_headroom(skb),
 356                                skb_tailroom(skb),
 357                                skb_headlen(skb),
 358                                sp->remain);
 359
 360                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 361                 }
 362
 363                 _debug("append");
 364                 sp = rxrpc_skb(skb);
 365
 366                 /* append next segment of data to the current buffer */
 367                 if (msg_data_left(msg) > 0) {
 368                         int copy = skb_tailroom(skb);
 369                         ASSERTCMP(copy, >, 0);
 370                         if (copy > msg_data_left(msg))
 371                                 copy = msg_data_left(msg);
 372                         if (copy > sp->remain)
 373                                 copy = sp->remain;
 374
 375                         _debug("add");
 376                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 377                         _debug("added");
 378                         if (ret < 0)
 379                                 goto efault;
 380                         sp->remain -= copy;
 381                         skb->mark += copy;
 382                         copied += copy;
 383                         if (call->tx_total_len != -1)
 384                                 call->tx_total_len -= copy;
 385                 }
 386
 387                 /* add the packet to the send queue if it's now full */
 388                 if (sp->remain <= 0 ||
 389                     (msg_data_left(msg) == 0 && !more)) {
 390                         struct rxrpc_connection *conn = call->conn;
 391                         uint32_t seq;
 392                         size_t pad;
 393
 394                         /* pad out if we're using security */
 395                         if (conn->security_ix) {
 396                                 pad = conn->security_size + skb->mark;
 397                                 pad = conn->size_align - pad;
 398                                 pad &= conn->size_align - 1;
 399                                 _debug("pad %zu", pad);
 400                                 if (pad)
 401                                         skb_put_zero(skb, pad);
 402                         }
 403
 404                         seq = call->tx_top + 1;
 405
 406                         sp->hdr.seq     = seq;
 407                         sp->hdr._rsvd   = 0;
 408                         sp->hdr.flags   = conn->out_clientflag;
 409
 410                         if (msg_data_left(msg) == 0 && !more)
 411                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 412                         else if (call->tx_top - call->tx_hard_ack <
 413                                  call->tx_winsize)
 414                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 415
 416                         ret = conn->security->secure_packet(
 417                                 call, skb, skb->mark, skb->head);
 418                         if (ret < 0)
 419                                 goto out;
 420
 421                         rxrpc_queue_packet(rx, call, skb,
 422                                            !msg_data_left(msg) && !more,
 423                                            notify_end_tx);
 424                         skb = NULL;
 425                 }
 426
 427                 /* Check for the far side aborting the call or a network error
 428                  * occurring.  If this happens, save any packet that was under
 429                  * construction so that in the case of a network error, the
 430                  * call can be retried or redirected.
 431                  */
 432                 if (call->state == RXRPC_CALL_COMPLETE) {
 433                         ret = call->error;
 434                         goto out;
 435                 }
 436         } while (msg_data_left(msg) > 0);
 437
 438 success:
 439         ret = copied;
 440 out:
 441         call->tx_pending = skb;
 442         _leave(" = %d", ret);
 443         return ret;
 444
 445 maybe_error:
 446         if (copied)
 447                 goto success;
 448         goto out;
 449
 450 efault:
 451         ret = -EFAULT;
 452         goto out;
 453 }
 454
 455 /*
 456  * extract control messages from the sendmsg() control buffer
 457  */
 458 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 459 {
 460         struct cmsghdr *cmsg;
 461         bool got_user_ID = false;
 462         int len;
 463
 464         if (msg->msg_controllen == 0)
 465                 return -EINVAL;
 466
 467         for_each_cmsghdr(cmsg, msg) {
 468                 if (!CMSG_OK(msg, cmsg))
 469                         return -EINVAL;
 470
 471                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 472                 _debug("CMSG %d, %d, %d",
 473                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 474
 475                 if (cmsg->cmsg_level != SOL_RXRPC)
 476                         continue;
 477
 478                 switch (cmsg->cmsg_type) {
 479                 case RXRPC_USER_CALL_ID:
 480                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 481                                 if (len != sizeof(u32))
 482                                         return -EINVAL;
 483                                 p->user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 484                         } else {
 485                                 if (len != sizeof(unsigned long))
 486                                         return -EINVAL;
 487                                 p->user_call_ID = *(unsigned long *)
 488                                         CMSG_DATA(cmsg);
 489                         }
 490                         got_user_ID = true;
 491                         break;
 492
 493                 case RXRPC_ABORT:
 494                         if (p->command != RXRPC_CMD_SEND_DATA)
 495                                 return -EINVAL;
 496                         p->command = RXRPC_CMD_SEND_ABORT;
 497                         if (len != sizeof(p->abort_code))
 498                                 return -EINVAL;
 499                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 500                         if (p->abort_code == 0)
 501                                 return -EINVAL;
 502                         break;
 503
 504                 case RXRPC_ACCEPT:
 505                         if (p->command != RXRPC_CMD_SEND_DATA)
 506                                 return -EINVAL;
 507                         p->command = RXRPC_CMD_ACCEPT;
 508                         if (len != 0)
 509                                 return -EINVAL;
 510                         break;
 511
 512                 case RXRPC_EXCLUSIVE_CALL:
 513                         p->exclusive = true;
 514                         if (len != 0)
 515                                 return -EINVAL;
 516                         break;
 517
 518                 case RXRPC_UPGRADE_SERVICE:
 519                         p->upgrade = true;
 520                         if (len != 0)
 521                                 return -EINVAL;
 522                         break;
 523
 524                 case RXRPC_TX_LENGTH:
 525                         if (p->tx_total_len != -1 || len != sizeof(__s64))
 526                                 return -EINVAL;
 527                         p->tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 528                         if (p->tx_total_len < 0)
 529                                 return -EINVAL;
 530                         break;
 531
 532                 default:
 533                         return -EINVAL;
 534                 }
 535         }
 536
 537         if (!got_user_ID)
 538                 return -EINVAL;
 539         if (p->tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 540                 return -EINVAL;
 541         _leave(" = 0");
 542         return 0;
 543 }
 544
 545 /*
 546  * Create a new client call for sendmsg().
 547  * - Called with the socket lock held, which it must release.
 548  * - If it returns a call, the call's lock will need releasing by the caller.
 549  */
 550 static struct rxrpc_call *
 551 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 552                                   struct rxrpc_send_params *p)
 553         __releases(&rx->sk.sk_lock.slock)
 554 {
 555         struct rxrpc_conn_parameters cp;
 556         struct rxrpc_call *call;
 557         struct key *key;
 558
 559         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 560
 561         _enter("");
 562
 563         if (!msg->msg_name) {
 564                 release_sock(&rx->sk);
 565                 return ERR_PTR(-EDESTADDRREQ);
 566         }
 567
 568         key = rx->key;
 569         if (key && !rx->key->payload.data[0])
 570                 key = NULL;
 571
 572         memset(&cp, 0, sizeof(cp));
 573         cp.local                = rx->local;
 574         cp.key                  = rx->key;
 575         cp.security_level       = rx->min_sec_level;
 576         cp.exclusive            = rx->exclusive | p->exclusive;
 577         cp.upgrade              = p->upgrade;
 578         cp.service_id           = srx->srx_service;
 579         call = rxrpc_new_client_call(rx, &cp, srx, p->user_call_ID,
 580                                      p->tx_total_len, GFP_KERNEL);
 581         /* The socket is now unlocked */
 582
 583         _leave(" = %p\n", call);
 584         return call;
 585 }
 586
 587 /*
 588  * send a message forming part of a client call through an RxRPC socket
 589  * - caller holds the socket locked
 590  * - the socket may be either a client socket or a server socket
 591  */
 592 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 593         __releases(&rx->sk.sk_lock.slock)
 594 {
 595         enum rxrpc_call_state state;
 596         struct rxrpc_call *call;
 597         int ret;
 598
 599         struct rxrpc_send_params p = {
 600                 .tx_total_len   = -1,
 601                 .user_call_ID   = 0,
 602                 .abort_code     = 0,
 603                 .command        = RXRPC_CMD_SEND_DATA,
 604                 .exclusive      = false,
 605                 .upgrade        = true,
 606         };
 607
 608         _enter("");
 609
 610         ret = rxrpc_sendmsg_cmsg(msg, &p);
 611         if (ret < 0)
 612                 goto error_release_sock;
 613
 614         if (p.command == RXRPC_CMD_ACCEPT) {
 615                 ret = -EINVAL;
 616                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 617                         goto error_release_sock;
 618                 call = rxrpc_accept_call(rx, p.user_call_ID, NULL);
 619                 /* The socket is now unlocked. */
 620                 if (IS_ERR(call))
 621                         return PTR_ERR(call);
 622                 rxrpc_put_call(call, rxrpc_call_put);
 623                 return 0;
 624         }
 625
 626         call = rxrpc_find_call_by_user_ID(rx, p.user_call_ID);
 627         if (!call) {
 628                 ret = -EBADSLT;
 629                 if (p.command != RXRPC_CMD_SEND_DATA)
 630                         goto error_release_sock;
 631                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 632                 /* The socket is now unlocked... */
 633                 if (IS_ERR(call))
 634                         return PTR_ERR(call);
 635                 /* ... and we have the call lock. */
 636         } else {
 637                 switch (READ_ONCE(call->state)) {
 638                 case RXRPC_CALL_UNINITIALISED:
 639                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 640                 case RXRPC_CALL_SERVER_PREALLOC:
 641                 case RXRPC_CALL_SERVER_SECURING:
 642                 case RXRPC_CALL_SERVER_ACCEPTING:
 643                         ret = -EBUSY;
 644                         goto error_release_sock;
 645                 default:
 646                         break;
 647                 }
 648
 649                 ret = mutex_lock_interruptible(&call->user_mutex);
 650                 release_sock(&rx->sk);
 651                 if (ret < 0) {
 652                         ret = -ERESTARTSYS;
 653                         goto error_put;
 654                 }
 655
 656                 if (p.tx_total_len != -1) {
 657                         ret = -EINVAL;
 658                         if (call->tx_total_len != -1 ||
 659                             call->tx_pending ||
 660                             call->tx_top != 0)
 661                                 goto error_put;
 662                         call->tx_total_len = p.tx_total_len;
 663                 }
 664         }
 665
 666         state = READ_ONCE(call->state);
 667         _debug("CALL %d USR %lx ST %d on CONN %p",
 668                call->debug_id, call->user_call_ID, state, call->conn);
 669
 670         if (state >= RXRPC_CALL_COMPLETE) {
 671                 /* it's too late for this call */
 672                 ret = -ESHUTDOWN;
 673         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 674                 ret = 0;
 675                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 676                         ret = rxrpc_send_abort_packet(call);
 677         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 678                 ret = -EINVAL;
 679         } else if (rxrpc_is_client_call(call) &&
 680                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 681                 /* request phase complete for this client call */
 682                 ret = -EPROTO;
 683         } else if (rxrpc_is_service_call(call) &&
 684                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 685                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 686                 /* Reply phase not begun or not complete for service call. */
 687                 ret = -EPROTO;
 688         } else {
 689                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 690         }
 691
 692         mutex_unlock(&call->user_mutex);
 693 error_put:
 694         rxrpc_put_call(call, rxrpc_call_put);
 695         _leave(" = %d", ret);
 696         return ret;
 697
 698 error_release_sock:
 699         release_sock(&rx->sk);
 700         return ret;
 701 }
 702
 703 /**
 704  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 705  * @sock: The socket the call is on
 706  * @call: The call to send data through
 707  * @msg: The data to send
 708  * @len: The amount of data to send
 709  * @notify_end_tx: Notification that the last packet is queued.
 710  *
 711  * Allow a kernel service to send data on a call.  The call must be in an state
 712  * appropriate to sending data.  No control data should be supplied in @msg,
 713  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 714  * more data to come, otherwise this data will end the transmission phase.
 715  */
 716 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 717                            struct msghdr *msg, size_t len,
 718                            rxrpc_notify_end_tx_t notify_end_tx)
 719 {
 720         int ret;
 721
 722         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 723
 724         ASSERTCMP(msg->msg_name, ==, NULL);
 725         ASSERTCMP(msg->msg_control, ==, NULL);
 726
 727         mutex_lock(&call->user_mutex);
 728
 729         _debug("CALL %d USR %lx ST %d on CONN %p",
 730                call->debug_id, call->user_call_ID, call->state, call->conn);
 731
 732         switch (READ_ONCE(call->state)) {
 733         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 734         case RXRPC_CALL_SERVER_ACK_REQUEST:
 735         case RXRPC_CALL_SERVER_SEND_REPLY:
 736                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 737                                       notify_end_tx);
 738                 break;
 739         case RXRPC_CALL_COMPLETE:
 740                 read_lock_bh(&call->state_lock);
 741                 ret = call->error;
 742                 read_unlock_bh(&call->state_lock);
 743                 break;
 744         default:
 745                 /* Request phase complete for this client call */
 746                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 747                 ret = -EPROTO;
 748                 break;
 749         }
 750
 751         mutex_unlock(&call->user_mutex);
 752         _leave(" = %d", ret);
 753         return ret;
 754 }
 755 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 756
 757 /**
 758  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 759  * @sock: The socket the call is on
 760  * @call: The call to be aborted
 761  * @abort_code: The abort code to stick into the ABORT packet
 762  * @error: Local error value
 763  * @why: 3-char string indicating why.
 764  *
 765  * Allow a kernel service to abort a call, if it's still in an abortable state
 766  * and return true if the call was aborted, false if it was already complete.
 767  */
 768 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 769                              u32 abort_code, int error, const char *why)
 770 {
 771         bool aborted;
 772
 773         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 774
 775         mutex_lock(&call->user_mutex);
 776
 777         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 778         if (aborted)
 779                 rxrpc_send_abort_packet(call);
 780
 781         mutex_unlock(&call->user_mutex);
 782         return aborted;
 783 }
 784 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 785
 786 /**
 787  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 788  * @sock: The socket the call is on
 789  * @call: The call to be informed
 790  * @tx_total_len: The amount of data to be transmitted for this call
 791  *
 792  * Allow a kernel service to set the total transmit length on a call.  This
 793  * allows buffer-to-packet encrypt-and-copy to be performed.
 794  *
 795  * This function is primarily for use for setting the reply length since the
 796  * request length can be set when beginning the call.
 797  */
 798 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 799                                 s64 tx_total_len)
 800 {
 801         WARN_ON(call->tx_total_len != -1);
 802         call->tx_total_len = tx_total_len;
 803 }
 804 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);