net/rxrpc/sendmsg.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* AF_RXRPC sendmsg() implementation.
   3  *
   4  * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
   5  * Written by David Howells (dhowells@redhat.com)
   6  */
   7
   8 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   9
  10 #include <linux/net.h>
  11 #include <linux/gfp.h>
  12 #include <linux/skbuff.h>
  13 #include <linux/export.h>
  14 #include <linux/sched/signal.h>
  15
  16 #include <net/sock.h>
  17 #include <net/af_rxrpc.h>
  18 #include "ar-internal.h"
  19
  20 /*
  21  * Wait for space to appear in the Tx queue or a signal to occur.
  22  */
  23 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
  24                                          struct rxrpc_call *call,
  25                                          long *timeo)
  26 {
  27         for (;;) {
  28                 set_current_state(TASK_INTERRUPTIBLE);
  29                 if (call->tx_top - call->tx_hard_ack <
  30                     min_t(unsigned int, call->tx_winsize,
  31                           call->cong_cwnd + call->cong_extra))
  32                         return 0;
  33
  34                 if (call->state >= RXRPC_CALL_COMPLETE)
  35                         return call->error;
  36
  37                 if (signal_pending(current))
  38                         return sock_intr_errno(*timeo);
  39
  40                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  41                 mutex_unlock(&call->user_mutex);
  42                 *timeo = schedule_timeout(*timeo);
  43                 if (mutex_lock_interruptible(&call->user_mutex) < 0)
  44                         return sock_intr_errno(*timeo);
  45         }
  46 }
  47
  48 /*
  49  * Wait for space to appear in the Tx queue uninterruptibly, but with
  50  * a timeout of 2*RTT if no progress was made and a signal occurred.
  51  */
  52 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
  53                                             struct rxrpc_call *call)
  54 {
  55         rxrpc_seq_t tx_start, tx_win;
  56         signed long rtt2, timeout;
  57         u64 rtt;
  58
  59         rtt = READ_ONCE(call->peer->rtt);
  60         rtt2 = nsecs_to_jiffies64(rtt) * 2;
  61         if (rtt2 < 1)
  62                 rtt2 = 1;
  63
  64         timeout = rtt2;
  65         tx_start = READ_ONCE(call->tx_hard_ack);
  66
  67         for (;;) {
  68                 set_current_state(TASK_UNINTERRUPTIBLE);
  69
  70                 tx_win = READ_ONCE(call->tx_hard_ack);
  71                 if (call->tx_top - tx_win <
  72                     min_t(unsigned int, call->tx_winsize,
  73                           call->cong_cwnd + call->cong_extra))
  74                         return 0;
  75
  76                 if (call->state >= RXRPC_CALL_COMPLETE)
  77                         return call->error;
  78
  79                 if (test_bit(RXRPC_CALL_IS_INTR, &call->flags) &&
  80                     timeout == 0 &&
  81                     tx_win == tx_start && signal_pending(current))
  82                         return -EINTR;
  83
  84                 if (tx_win != tx_start) {
  85                         timeout = rtt2;
  86                         tx_start = tx_win;
  87                 }
  88
  89                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  90                 timeout = schedule_timeout(timeout);
  91         }
  92 }
  93
  94 /*
  95  * wait for space to appear in the transmit/ACK window
  96  * - caller holds the socket locked
  97  */
  98 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
  99                                     struct rxrpc_call *call,
 100                                     long *timeo,
 101                                     bool waitall)
 102 {
 103         DECLARE_WAITQUEUE(myself, current);
 104         int ret;
 105
 106         _enter(",{%u,%u,%u}",
 107                call->tx_hard_ack, call->tx_top, call->tx_winsize);
 108
 109         add_wait_queue(&call->waitq, &myself);
 110
 111         if (waitall)
 112                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call);
 113         else
 114                 ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 115
 116         remove_wait_queue(&call->waitq, &myself);
 117         set_current_state(TASK_RUNNING);
 118         _leave(" = %d", ret);
 119         return ret;
 120 }
 121
 122 /*
 123  * Schedule an instant Tx resend.
 124  */
 125 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
 126 {
 127         spin_lock_bh(&call->lock);
 128
 129         if (call->state < RXRPC_CALL_COMPLETE) {
 130                 call->rxtx_annotations[ix] =
 131                         (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
 132                         RXRPC_TX_ANNO_RETRANS;
 133                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
 134                         rxrpc_queue_call(call);
 135         }
 136
 137         spin_unlock_bh(&call->lock);
 138 }
 139
 140 /*
 141  * Notify the owner of the call that the transmit phase is ended and the last
 142  * packet has been queued.
 143  */
 144 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 145                                 rxrpc_notify_end_tx_t notify_end_tx)
 146 {
 147         if (notify_end_tx)
 148                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 149 }
 150
 151 /*
 152  * Queue a DATA packet for transmission, set the resend timeout and send
 153  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 154  * in case the caller wants to do something with it.
 155  */
 156 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 157                               struct sk_buff *skb, bool last,
 158                               rxrpc_notify_end_tx_t notify_end_tx)
 159 {
 160         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 161         unsigned long now;
 162         rxrpc_seq_t seq = sp->hdr.seq;
 163         int ret, ix;
 164         u8 annotation = RXRPC_TX_ANNO_UNACK;
 165
 166         _net("queue skb %p [%d]", skb, seq);
 167
 168         ASSERTCMP(seq, ==, call->tx_top + 1);
 169
 170         if (last)
 171                 annotation |= RXRPC_TX_ANNO_LAST;
 172
 173         /* We have to set the timestamp before queueing as the retransmit
 174          * algorithm can see the packet as soon as we queue it.
 175          */
 176         skb->tstamp = ktime_get_real();
 177
 178         ix = seq & RXRPC_RXTX_BUFF_MASK;
 179         rxrpc_get_skb(skb, rxrpc_skb_tx_got);
 180         call->rxtx_annotations[ix] = annotation;
 181         smp_wmb();
 182         call->rxtx_buffer[ix] = skb;
 183         call->tx_top = seq;
 184         if (last)
 185                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 186         else
 187                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 188
 189         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 190                 _debug("________awaiting reply/ACK__________");
 191                 write_lock_bh(&call->state_lock);
 192                 switch (call->state) {
 193                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 194                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 195                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 196                         break;
 197                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 198                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 199                         now = jiffies;
 200                         WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
 201                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 202                                 call->ackr_reason = 0;
 203                         trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
 204                         if (!last)
 205                                 break;
 206                         /* Fall through */
 207                 case RXRPC_CALL_SERVER_SEND_REPLY:
 208                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 209                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 210                         break;
 211                 default:
 212                         break;
 213                 }
 214                 write_unlock_bh(&call->state_lock);
 215         }
 216
 217         if (seq == 1 && rxrpc_is_client_call(call))
 218                 rxrpc_expose_client_call(call);
 219
 220         ret = rxrpc_send_data_packet(call, skb, false);
 221         if (ret < 0) {
 222                 switch (ret) {
 223                 case -ENETUNREACH:
 224                 case -EHOSTUNREACH:
 225                 case -ECONNREFUSED:
 226                         rxrpc_set_call_completion(call,
 227                                                   RXRPC_CALL_LOCAL_ERROR,
 228                                                   0, ret);
 229                         goto out;
 230                 }
 231                 _debug("need instant resend %d", ret);
 232                 rxrpc_instant_resend(call, ix);
 233         } else {
 234                 unsigned long now = jiffies, resend_at;
 235
 236                 if (call->peer->rtt_usage > 1)
 237                         resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
 238                 else
 239                         resend_at = rxrpc_resend_timeout;
 240                 if (resend_at < 1)
 241                         resend_at = 1;
 242
 243                 resend_at += now;
 244                 WRITE_ONCE(call->resend_at, resend_at);
 245                 rxrpc_reduce_call_timer(call, resend_at, now,
 246                                         rxrpc_timer_set_for_send);
 247         }
 248
 249 out:
 250         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 251         _leave(" = %d", ret);
 252         return ret;
 253 }
 254
 255 /*
 256  * send data through a socket
 257  * - must be called in process context
 258  * - The caller holds the call user access mutex, but not the socket lock.
 259  */
 260 static int rxrpc_send_data(struct rxrpc_sock *rx,
 261                            struct rxrpc_call *call,
 262                            struct msghdr *msg, size_t len,
 263                            rxrpc_notify_end_tx_t notify_end_tx)
 264 {
 265         struct rxrpc_skb_priv *sp;
 266         struct sk_buff *skb;
 267         struct sock *sk = &rx->sk;
 268         long timeo;
 269         bool more;
 270         int ret, copied;
 271
 272         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 273
 274         /* this should be in poll */
 275         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 276
 277         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 278                 return -EPIPE;
 279
 280         more = msg->msg_flags & MSG_MORE;
 281
 282         if (call->tx_total_len != -1) {
 283                 if (len > call->tx_total_len)
 284                         return -EMSGSIZE;
 285                 if (!more && len != call->tx_total_len)
 286                         return -EMSGSIZE;
 287         }
 288
 289         skb = call->tx_pending;
 290         call->tx_pending = NULL;
 291         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 292
 293         copied = 0;
 294         do {
 295                 /* Check to see if there's a ping ACK to reply to. */
 296                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 297                         rxrpc_send_ack_packet(call, false, NULL);
 298
 299                 if (!skb) {
 300                         size_t size, chunk, max, space;
 301
 302                         _debug("alloc");
 303
 304                         if (call->tx_top - call->tx_hard_ack >=
 305                             min_t(unsigned int, call->tx_winsize,
 306                                   call->cong_cwnd + call->cong_extra)) {
 307                                 ret = -EAGAIN;
 308                                 if (msg->msg_flags & MSG_DONTWAIT)
 309                                         goto maybe_error;
 310                                 ret = rxrpc_wait_for_tx_window(rx, call,
 311                                                                &timeo,
 312                                                                msg->msg_flags & MSG_WAITALL);
 313                                 if (ret < 0)
 314                                         goto maybe_error;
 315                         }
 316
 317                         max = RXRPC_JUMBO_DATALEN;
 318                         max -= call->conn->security_size;
 319                         max &= ~(call->conn->size_align - 1UL);
 320
 321                         chunk = max;
 322                         if (chunk > msg_data_left(msg) && !more)
 323                                 chunk = msg_data_left(msg);
 324
 325                         space = chunk + call->conn->size_align;
 326                         space &= ~(call->conn->size_align - 1UL);
 327
 328                         size = space + call->conn->security_size;
 329
 330                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 331
 332                         /* create a buffer that we can retain until it's ACK'd */
 333                         skb = sock_alloc_send_skb(
 334                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 335                         if (!skb)
 336                                 goto maybe_error;
 337
 338                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 339
 340                         _debug("ALLOC SEND %p", skb);
 341
 342                         ASSERTCMP(skb->mark, ==, 0);
 343
 344                         _debug("HS: %u", call->conn->security_size);
 345                         skb_reserve(skb, call->conn->security_size);
 346                         skb->len += call->conn->security_size;
 347
 348                         sp = rxrpc_skb(skb);
 349                         sp->remain = chunk;
 350                         if (sp->remain > skb_tailroom(skb))
 351                                 sp->remain = skb_tailroom(skb);
 352
 353                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 354                                skb_headroom(skb),
 355                                skb_tailroom(skb),
 356                                skb_headlen(skb),
 357                                sp->remain);
 358
 359                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 360                 }
 361
 362                 _debug("append");
 363                 sp = rxrpc_skb(skb);
 364
 365                 /* append next segment of data to the current buffer */
 366                 if (msg_data_left(msg) > 0) {
 367                         int copy = skb_tailroom(skb);
 368                         ASSERTCMP(copy, >, 0);
 369                         if (copy > msg_data_left(msg))
 370                                 copy = msg_data_left(msg);
 371                         if (copy > sp->remain)
 372                                 copy = sp->remain;
 373
 374                         _debug("add");
 375                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 376                         _debug("added");
 377                         if (ret < 0)
 378                                 goto efault;
 379                         sp->remain -= copy;
 380                         skb->mark += copy;
 381                         copied += copy;
 382                         if (call->tx_total_len != -1)
 383                                 call->tx_total_len -= copy;
 384                 }
 385
 386                 /* check for the far side aborting the call or a network error
 387                  * occurring */
 388                 if (call->state == RXRPC_CALL_COMPLETE)
 389                         goto call_terminated;
 390
 391                 /* add the packet to the send queue if it's now full */
 392                 if (sp->remain <= 0 ||
 393                     (msg_data_left(msg) == 0 && !more)) {
 394                         struct rxrpc_connection *conn = call->conn;
 395                         uint32_t seq;
 396                         size_t pad;
 397
 398                         /* pad out if we're using security */
 399                         if (conn->security_ix) {
 400                                 pad = conn->security_size + skb->mark;
 401                                 pad = conn->size_align - pad;
 402                                 pad &= conn->size_align - 1;
 403                                 _debug("pad %zu", pad);
 404                                 if (pad)
 405                                         skb_put_zero(skb, pad);
 406                         }
 407
 408                         seq = call->tx_top + 1;
 409
 410                         sp->hdr.seq     = seq;
 411                         sp->hdr._rsvd   = 0;
 412                         sp->hdr.flags   = conn->out_clientflag;
 413
 414                         if (msg_data_left(msg) == 0 && !more)
 415                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 416                         else if (call->tx_top - call->tx_hard_ack <
 417                                  call->tx_winsize)
 418                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 419
 420                         ret = conn->security->secure_packet(
 421                                 call, skb, skb->mark, skb->head);
 422                         if (ret < 0)
 423                                 goto out;
 424
 425                         ret = rxrpc_queue_packet(rx, call, skb,
 426                                                  !msg_data_left(msg) && !more,
 427                                                  notify_end_tx);
 428                         /* Should check for failure here */
 429                         skb = NULL;
 430                 }
 431         } while (msg_data_left(msg) > 0);
 432
 433 success:
 434         ret = copied;
 435 out:
 436         call->tx_pending = skb;
 437         _leave(" = %d", ret);
 438         return ret;
 439
 440 call_terminated:
 441         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 442         _leave(" = %d", call->error);
 443         return call->error;
 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->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 484                         } else {
 485                                 if (len != sizeof(unsigned long))
 486                                         return -EINVAL;
 487                                 p->call.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->call.tx_total_len != -1 || len != sizeof(__s64))
 526                                 return -EINVAL;
 527                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 528                         if (p->call.tx_total_len < 0)
 529                                 return -EINVAL;
 530                         break;
 531
 532                 case RXRPC_SET_CALL_TIMEOUT:
 533                         if (len & 3 || len < 4 || len > 12)
 534                                 return -EINVAL;
 535                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 536                         p->call.nr_timeouts = len / 4;
 537                         if (p->call.timeouts.hard > INT_MAX / HZ)
 538                                 return -ERANGE;
 539                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 540                                 return -ERANGE;
 541                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 542                                 return -ERANGE;
 543                         break;
 544
 545                 default:
 546                         return -EINVAL;
 547                 }
 548         }
 549
 550         if (!got_user_ID)
 551                 return -EINVAL;
 552         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 553                 return -EINVAL;
 554         _leave(" = 0");
 555         return 0;
 556 }
 557
 558 /*
 559  * Create a new client call for sendmsg().
 560  * - Called with the socket lock held, which it must release.
 561  * - If it returns a call, the call's lock will need releasing by the caller.
 562  */
 563 static struct rxrpc_call *
 564 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 565                                   struct rxrpc_send_params *p)
 566         __releases(&rx->sk.sk_lock.slock)
 567         __acquires(&call->user_mutex)
 568 {
 569         struct rxrpc_conn_parameters cp;
 570         struct rxrpc_call *call;
 571         struct key *key;
 572
 573         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 574
 575         _enter("");
 576
 577         if (!msg->msg_name) {
 578                 release_sock(&rx->sk);
 579                 return ERR_PTR(-EDESTADDRREQ);
 580         }
 581
 582         key = rx->key;
 583         if (key && !rx->key->payload.data[0])
 584                 key = NULL;
 585
 586         memset(&cp, 0, sizeof(cp));
 587         cp.local                = rx->local;
 588         cp.key                  = rx->key;
 589         cp.security_level       = rx->min_sec_level;
 590         cp.exclusive            = rx->exclusive | p->exclusive;
 591         cp.upgrade              = p->upgrade;
 592         cp.service_id           = srx->srx_service;
 593         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 594                                      atomic_inc_return(&rxrpc_debug_id));
 595         /* The socket is now unlocked */
 596
 597         rxrpc_put_peer(cp.peer);
 598         _leave(" = %p\n", call);
 599         return call;
 600 }
 601
 602 /*
 603  * send a message forming part of a client call through an RxRPC socket
 604  * - caller holds the socket locked
 605  * - the socket may be either a client socket or a server socket
 606  */
 607 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 608         __releases(&rx->sk.sk_lock.slock)
 609         __releases(&call->user_mutex)
 610 {
 611         enum rxrpc_call_state state;
 612         struct rxrpc_call *call;
 613         unsigned long now, j;
 614         int ret;
 615
 616         struct rxrpc_send_params p = {
 617                 .call.tx_total_len      = -1,
 618                 .call.user_call_ID      = 0,
 619                 .call.nr_timeouts       = 0,
 620                 .call.intr              = true,
 621                 .abort_code             = 0,
 622                 .command                = RXRPC_CMD_SEND_DATA,
 623                 .exclusive              = false,
 624                 .upgrade                = false,
 625         };
 626
 627         _enter("");
 628
 629         ret = rxrpc_sendmsg_cmsg(msg, &p);
 630         if (ret < 0)
 631                 goto error_release_sock;
 632
 633         if (p.command == RXRPC_CMD_ACCEPT) {
 634                 ret = -EINVAL;
 635                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 636                         goto error_release_sock;
 637                 call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
 638                 /* The socket is now unlocked. */
 639                 if (IS_ERR(call))
 640                         return PTR_ERR(call);
 641                 ret = 0;
 642                 goto out_put_unlock;
 643         }
 644
 645         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 646         if (!call) {
 647                 ret = -EBADSLT;
 648                 if (p.command != RXRPC_CMD_SEND_DATA)
 649                         goto error_release_sock;
 650                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 651                 /* The socket is now unlocked... */
 652                 if (IS_ERR(call))
 653                         return PTR_ERR(call);
 654                 /* ... and we have the call lock. */
 655         } else {
 656                 switch (READ_ONCE(call->state)) {
 657                 case RXRPC_CALL_UNINITIALISED:
 658                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 659                 case RXRPC_CALL_SERVER_PREALLOC:
 660                 case RXRPC_CALL_SERVER_SECURING:
 661                 case RXRPC_CALL_SERVER_ACCEPTING:
 662                         ret = -EBUSY;
 663                         goto error_release_sock;
 664                 default:
 665                         break;
 666                 }
 667
 668                 ret = mutex_lock_interruptible(&call->user_mutex);
 669                 release_sock(&rx->sk);
 670                 if (ret < 0) {
 671                         ret = -ERESTARTSYS;
 672                         goto error_put;
 673                 }
 674
 675                 if (p.call.tx_total_len != -1) {
 676                         ret = -EINVAL;
 677                         if (call->tx_total_len != -1 ||
 678                             call->tx_pending ||
 679                             call->tx_top != 0)
 680                                 goto error_put;
 681                         call->tx_total_len = p.call.tx_total_len;
 682                 }
 683         }
 684
 685         switch (p.call.nr_timeouts) {
 686         case 3:
 687                 j = msecs_to_jiffies(p.call.timeouts.normal);
 688                 if (p.call.timeouts.normal > 0 && j == 0)
 689                         j = 1;
 690                 WRITE_ONCE(call->next_rx_timo, j);
 691                 /* Fall through */
 692         case 2:
 693                 j = msecs_to_jiffies(p.call.timeouts.idle);
 694                 if (p.call.timeouts.idle > 0 && j == 0)
 695                         j = 1;
 696                 WRITE_ONCE(call->next_req_timo, j);
 697                 /* Fall through */
 698         case 1:
 699                 if (p.call.timeouts.hard > 0) {
 700                         j = msecs_to_jiffies(p.call.timeouts.hard);
 701                         now = jiffies;
 702                         j += now;
 703                         WRITE_ONCE(call->expect_term_by, j);
 704                         rxrpc_reduce_call_timer(call, j, now,
 705                                                 rxrpc_timer_set_for_hard);
 706                 }
 707                 break;
 708         }
 709
 710         state = READ_ONCE(call->state);
 711         _debug("CALL %d USR %lx ST %d on CONN %p",
 712                call->debug_id, call->user_call_ID, state, call->conn);
 713
 714         if (state >= RXRPC_CALL_COMPLETE) {
 715                 /* it's too late for this call */
 716                 ret = -ESHUTDOWN;
 717         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 718                 ret = 0;
 719                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 720                         ret = rxrpc_send_abort_packet(call);
 721         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 722                 ret = -EINVAL;
 723         } else if (rxrpc_is_client_call(call) &&
 724                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 725                 /* request phase complete for this client call */
 726                 ret = -EPROTO;
 727         } else if (rxrpc_is_service_call(call) &&
 728                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 729                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 730                 /* Reply phase not begun or not complete for service call. */
 731                 ret = -EPROTO;
 732         } else {
 733                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 734         }
 735
 736 out_put_unlock:
 737         mutex_unlock(&call->user_mutex);
 738 error_put:
 739         rxrpc_put_call(call, rxrpc_call_put);
 740         _leave(" = %d", ret);
 741         return ret;
 742
 743 error_release_sock:
 744         release_sock(&rx->sk);
 745         return ret;
 746 }
 747
 748 /**
 749  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 750  * @sock: The socket the call is on
 751  * @call: The call to send data through
 752  * @msg: The data to send
 753  * @len: The amount of data to send
 754  * @notify_end_tx: Notification that the last packet is queued.
 755  *
 756  * Allow a kernel service to send data on a call.  The call must be in an state
 757  * appropriate to sending data.  No control data should be supplied in @msg,
 758  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 759  * more data to come, otherwise this data will end the transmission phase.
 760  */
 761 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 762                            struct msghdr *msg, size_t len,
 763                            rxrpc_notify_end_tx_t notify_end_tx)
 764 {
 765         int ret;
 766
 767         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 768
 769         ASSERTCMP(msg->msg_name, ==, NULL);
 770         ASSERTCMP(msg->msg_control, ==, NULL);
 771
 772         mutex_lock(&call->user_mutex);
 773
 774         _debug("CALL %d USR %lx ST %d on CONN %p",
 775                call->debug_id, call->user_call_ID, call->state, call->conn);
 776
 777         switch (READ_ONCE(call->state)) {
 778         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 779         case RXRPC_CALL_SERVER_ACK_REQUEST:
 780         case RXRPC_CALL_SERVER_SEND_REPLY:
 781                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 782                                       notify_end_tx);
 783                 break;
 784         case RXRPC_CALL_COMPLETE:
 785                 read_lock_bh(&call->state_lock);
 786                 ret = call->error;
 787                 read_unlock_bh(&call->state_lock);
 788                 break;
 789         default:
 790                 /* Request phase complete for this client call */
 791                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 792                 ret = -EPROTO;
 793                 break;
 794         }
 795
 796         mutex_unlock(&call->user_mutex);
 797         _leave(" = %d", ret);
 798         return ret;
 799 }
 800 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 801
 802 /**
 803  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 804  * @sock: The socket the call is on
 805  * @call: The call to be aborted
 806  * @abort_code: The abort code to stick into the ABORT packet
 807  * @error: Local error value
 808  * @why: 3-char string indicating why.
 809  *
 810  * Allow a kernel service to abort a call, if it's still in an abortable state
 811  * and return true if the call was aborted, false if it was already complete.
 812  */
 813 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 814                              u32 abort_code, int error, const char *why)
 815 {
 816         bool aborted;
 817
 818         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 819
 820         mutex_lock(&call->user_mutex);
 821
 822         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 823         if (aborted)
 824                 rxrpc_send_abort_packet(call);
 825
 826         mutex_unlock(&call->user_mutex);
 827         return aborted;
 828 }
 829 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 830
 831 /**
 832  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 833  * @sock: The socket the call is on
 834  * @call: The call to be informed
 835  * @tx_total_len: The amount of data to be transmitted for this call
 836  *
 837  * Allow a kernel service to set the total transmit length on a call.  This
 838  * allows buffer-to-packet encrypt-and-copy to be performed.
 839  *
 840  * This function is primarily for use for setting the reply length since the
 841  * request length can be set when beginning the call.
 842  */
 843 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 844                                 s64 tx_total_len)
 845 {
 846         WARN_ON(call->tx_total_len != -1);
 847         call->tx_total_len = tx_total_len;
 848 }
 849 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);