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_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                         rxrpc_notify_socket(call);
 230                         goto out;
 231                 }
 232                 _debug("need instant resend %d", ret);
 233                 rxrpc_instant_resend(call, ix);
 234         } else {
 235                 unsigned long now = jiffies, resend_at;
 236
 237                 if (call->peer->rtt_usage > 1)
 238                         resend_at = nsecs_to_jiffies(call->peer->rtt * 3 / 2);
 239                 else
 240                         resend_at = rxrpc_resend_timeout;
 241                 if (resend_at < 1)
 242                         resend_at = 1;
 243
 244                 resend_at += now;
 245                 WRITE_ONCE(call->resend_at, resend_at);
 246                 rxrpc_reduce_call_timer(call, resend_at, now,
 247                                         rxrpc_timer_set_for_send);
 248         }
 249
 250 out:
 251         rxrpc_free_skb(skb, rxrpc_skb_freed);
 252         _leave(" = %d", ret);
 253         return ret;
 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_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, NULL);
 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                         sp = rxrpc_skb(skb);
 340                         sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
 341                         rxrpc_new_skb(skb, rxrpc_skb_new);
 342
 343                         _debug("ALLOC SEND %p", skb);
 344
 345                         ASSERTCMP(skb->mark, ==, 0);
 346
 347                         _debug("HS: %u", call->conn->security_size);
 348                         skb_reserve(skb, call->conn->security_size);
 349                         skb->len += call->conn->security_size;
 350
 351                         sp->remain = chunk;
 352                         if (sp->remain > skb_tailroom(skb))
 353                                 sp->remain = skb_tailroom(skb);
 354
 355                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 356                                skb_headroom(skb),
 357                                skb_tailroom(skb),
 358                                skb_headlen(skb),
 359                                sp->remain);
 360
 361                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 362                 }
 363
 364                 _debug("append");
 365                 sp = rxrpc_skb(skb);
 366
 367                 /* append next segment of data to the current buffer */
 368                 if (msg_data_left(msg) > 0) {
 369                         int copy = skb_tailroom(skb);
 370                         ASSERTCMP(copy, >, 0);
 371                         if (copy > msg_data_left(msg))
 372                                 copy = msg_data_left(msg);
 373                         if (copy > sp->remain)
 374                                 copy = sp->remain;
 375
 376                         _debug("add");
 377                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 378                         _debug("added");
 379                         if (ret < 0)
 380                                 goto efault;
 381                         sp->remain -= copy;
 382                         skb->mark += copy;
 383                         copied += copy;
 384                         if (call->tx_total_len != -1)
 385                                 call->tx_total_len -= copy;
 386                 }
 387
 388                 /* check for the far side aborting the call or a network error
 389                  * occurring */
 390                 if (call->state == RXRPC_CALL_COMPLETE)
 391                         goto call_terminated;
 392
 393                 /* add the packet to the send queue if it's now full */
 394                 if (sp->remain <= 0 ||
 395                     (msg_data_left(msg) == 0 && !more)) {
 396                         struct rxrpc_connection *conn = call->conn;
 397                         uint32_t seq;
 398                         size_t pad;
 399
 400                         /* pad out if we're using security */
 401                         if (conn->security_ix) {
 402                                 pad = conn->security_size + skb->mark;
 403                                 pad = conn->size_align - pad;
 404                                 pad &= conn->size_align - 1;
 405                                 _debug("pad %zu", pad);
 406                                 if (pad)
 407                                         skb_put_zero(skb, pad);
 408                         }
 409
 410                         seq = call->tx_top + 1;
 411
 412                         sp->hdr.seq     = seq;
 413                         sp->hdr._rsvd   = 0;
 414                         sp->hdr.flags   = conn->out_clientflag;
 415
 416                         if (msg_data_left(msg) == 0 && !more)
 417                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 418                         else if (call->tx_top - call->tx_hard_ack <
 419                                  call->tx_winsize)
 420                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 421
 422                         ret = conn->security->secure_packet(
 423                                 call, skb, skb->mark, skb->head);
 424                         if (ret < 0)
 425                                 goto out;
 426
 427                         ret = rxrpc_queue_packet(rx, call, skb,
 428                                                  !msg_data_left(msg) && !more,
 429                                                  notify_end_tx);
 430                         /* Should check for failure here */
 431                         skb = NULL;
 432                 }
 433         } while (msg_data_left(msg) > 0);
 434
 435 success:
 436         ret = copied;
 437 out:
 438         call->tx_pending = skb;
 439         _leave(" = %d", ret);
 440         return ret;
 441
 442 call_terminated:
 443         rxrpc_free_skb(skb, rxrpc_skb_freed);
 444         _leave(" = %d", call->error);
 445         return call->error;
 446
 447 maybe_error:
 448         if (copied)
 449                 goto success;
 450         goto out;
 451
 452 efault:
 453         ret = -EFAULT;
 454         goto out;
 455 }
 456
 457 /*
 458  * extract control messages from the sendmsg() control buffer
 459  */
 460 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 461 {
 462         struct cmsghdr *cmsg;
 463         bool got_user_ID = false;
 464         int len;
 465
 466         if (msg->msg_controllen == 0)
 467                 return -EINVAL;
 468
 469         for_each_cmsghdr(cmsg, msg) {
 470                 if (!CMSG_OK(msg, cmsg))
 471                         return -EINVAL;
 472
 473                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 474                 _debug("CMSG %d, %d, %d",
 475                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 476
 477                 if (cmsg->cmsg_level != SOL_RXRPC)
 478                         continue;
 479
 480                 switch (cmsg->cmsg_type) {
 481                 case RXRPC_USER_CALL_ID:
 482                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 483                                 if (len != sizeof(u32))
 484                                         return -EINVAL;
 485                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 486                         } else {
 487                                 if (len != sizeof(unsigned long))
 488                                         return -EINVAL;
 489                                 p->call.user_call_ID = *(unsigned long *)
 490                                         CMSG_DATA(cmsg);
 491                         }
 492                         got_user_ID = true;
 493                         break;
 494
 495                 case RXRPC_ABORT:
 496                         if (p->command != RXRPC_CMD_SEND_DATA)
 497                                 return -EINVAL;
 498                         p->command = RXRPC_CMD_SEND_ABORT;
 499                         if (len != sizeof(p->abort_code))
 500                                 return -EINVAL;
 501                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 502                         if (p->abort_code == 0)
 503                                 return -EINVAL;
 504                         break;
 505
 506                 case RXRPC_ACCEPT:
 507                         if (p->command != RXRPC_CMD_SEND_DATA)
 508                                 return -EINVAL;
 509                         p->command = RXRPC_CMD_ACCEPT;
 510                         if (len != 0)
 511                                 return -EINVAL;
 512                         break;
 513
 514                 case RXRPC_EXCLUSIVE_CALL:
 515                         p->exclusive = true;
 516                         if (len != 0)
 517                                 return -EINVAL;
 518                         break;
 519
 520                 case RXRPC_UPGRADE_SERVICE:
 521                         p->upgrade = true;
 522                         if (len != 0)
 523                                 return -EINVAL;
 524                         break;
 525
 526                 case RXRPC_TX_LENGTH:
 527                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 528                                 return -EINVAL;
 529                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 530                         if (p->call.tx_total_len < 0)
 531                                 return -EINVAL;
 532                         break;
 533
 534                 case RXRPC_SET_CALL_TIMEOUT:
 535                         if (len & 3 || len < 4 || len > 12)
 536                                 return -EINVAL;
 537                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 538                         p->call.nr_timeouts = len / 4;
 539                         if (p->call.timeouts.hard > INT_MAX / HZ)
 540                                 return -ERANGE;
 541                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 542                                 return -ERANGE;
 543                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 544                                 return -ERANGE;
 545                         break;
 546
 547                 default:
 548                         return -EINVAL;
 549                 }
 550         }
 551
 552         if (!got_user_ID)
 553                 return -EINVAL;
 554         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 555                 return -EINVAL;
 556         _leave(" = 0");
 557         return 0;
 558 }
 559
 560 /*
 561  * Create a new client call for sendmsg().
 562  * - Called with the socket lock held, which it must release.
 563  * - If it returns a call, the call's lock will need releasing by the caller.
 564  */
 565 static struct rxrpc_call *
 566 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 567                                   struct rxrpc_send_params *p)
 568         __releases(&rx->sk.sk_lock.slock)
 569         __acquires(&call->user_mutex)
 570 {
 571         struct rxrpc_conn_parameters cp;
 572         struct rxrpc_call *call;
 573         struct key *key;
 574
 575         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 576
 577         _enter("");
 578
 579         if (!msg->msg_name) {
 580                 release_sock(&rx->sk);
 581                 return ERR_PTR(-EDESTADDRREQ);
 582         }
 583
 584         key = rx->key;
 585         if (key && !rx->key->payload.data[0])
 586                 key = NULL;
 587
 588         memset(&cp, 0, sizeof(cp));
 589         cp.local                = rx->local;
 590         cp.key                  = rx->key;
 591         cp.security_level       = rx->min_sec_level;
 592         cp.exclusive            = rx->exclusive | p->exclusive;
 593         cp.upgrade              = p->upgrade;
 594         cp.service_id           = srx->srx_service;
 595         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 596                                      atomic_inc_return(&rxrpc_debug_id));
 597         /* The socket is now unlocked */
 598
 599         rxrpc_put_peer(cp.peer);
 600         _leave(" = %p\n", call);
 601         return call;
 602 }
 603
 604 /*
 605  * send a message forming part of a client call through an RxRPC socket
 606  * - caller holds the socket locked
 607  * - the socket may be either a client socket or a server socket
 608  */
 609 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 610         __releases(&rx->sk.sk_lock.slock)
 611         __releases(&call->user_mutex)
 612 {
 613         enum rxrpc_call_state state;
 614         struct rxrpc_call *call;
 615         unsigned long now, j;
 616         int ret;
 617
 618         struct rxrpc_send_params p = {
 619                 .call.tx_total_len      = -1,
 620                 .call.user_call_ID      = 0,
 621                 .call.nr_timeouts       = 0,
 622                 .call.intr              = true,
 623                 .abort_code             = 0,
 624                 .command                = RXRPC_CMD_SEND_DATA,
 625                 .exclusive              = false,
 626                 .upgrade                = false,
 627         };
 628
 629         _enter("");
 630
 631         ret = rxrpc_sendmsg_cmsg(msg, &p);
 632         if (ret < 0)
 633                 goto error_release_sock;
 634
 635         if (p.command == RXRPC_CMD_ACCEPT) {
 636                 ret = -EINVAL;
 637                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 638                         goto error_release_sock;
 639                 call = rxrpc_accept_call(rx, p.call.user_call_ID, NULL);
 640                 /* The socket is now unlocked. */
 641                 if (IS_ERR(call))
 642                         return PTR_ERR(call);
 643                 ret = 0;
 644                 goto out_put_unlock;
 645         }
 646
 647         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 648         if (!call) {
 649                 ret = -EBADSLT;
 650                 if (p.command != RXRPC_CMD_SEND_DATA)
 651                         goto error_release_sock;
 652                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 653                 /* The socket is now unlocked... */
 654                 if (IS_ERR(call))
 655                         return PTR_ERR(call);
 656                 /* ... and we have the call lock. */
 657         } else {
 658                 switch (READ_ONCE(call->state)) {
 659                 case RXRPC_CALL_UNINITIALISED:
 660                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 661                 case RXRPC_CALL_SERVER_PREALLOC:
 662                 case RXRPC_CALL_SERVER_SECURING:
 663                 case RXRPC_CALL_SERVER_ACCEPTING:
 664                         rxrpc_put_call(call, rxrpc_call_put);
 665                         ret = -EBUSY;
 666                         goto error_release_sock;
 667                 default:
 668                         break;
 669                 }
 670
 671                 ret = mutex_lock_interruptible(&call->user_mutex);
 672                 release_sock(&rx->sk);
 673                 if (ret < 0) {
 674                         ret = -ERESTARTSYS;
 675                         goto error_put;
 676                 }
 677
 678                 if (p.call.tx_total_len != -1) {
 679                         ret = -EINVAL;
 680                         if (call->tx_total_len != -1 ||
 681                             call->tx_pending ||
 682                             call->tx_top != 0)
 683                                 goto error_put;
 684                         call->tx_total_len = p.call.tx_total_len;
 685                 }
 686         }
 687
 688         switch (p.call.nr_timeouts) {
 689         case 3:
 690                 j = msecs_to_jiffies(p.call.timeouts.normal);
 691                 if (p.call.timeouts.normal > 0 && j == 0)
 692                         j = 1;
 693                 WRITE_ONCE(call->next_rx_timo, j);
 694                 /* Fall through */
 695         case 2:
 696                 j = msecs_to_jiffies(p.call.timeouts.idle);
 697                 if (p.call.timeouts.idle > 0 && j == 0)
 698                         j = 1;
 699                 WRITE_ONCE(call->next_req_timo, j);
 700                 /* Fall through */
 701         case 1:
 702                 if (p.call.timeouts.hard > 0) {
 703                         j = msecs_to_jiffies(p.call.timeouts.hard);
 704                         now = jiffies;
 705                         j += now;
 706                         WRITE_ONCE(call->expect_term_by, j);
 707                         rxrpc_reduce_call_timer(call, j, now,
 708                                                 rxrpc_timer_set_for_hard);
 709                 }
 710                 break;
 711         }
 712
 713         state = READ_ONCE(call->state);
 714         _debug("CALL %d USR %lx ST %d on CONN %p",
 715                call->debug_id, call->user_call_ID, state, call->conn);
 716
 717         if (state >= RXRPC_CALL_COMPLETE) {
 718                 /* it's too late for this call */
 719                 ret = -ESHUTDOWN;
 720         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 721                 ret = 0;
 722                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 723                         ret = rxrpc_send_abort_packet(call);
 724         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 725                 ret = -EINVAL;
 726         } else if (rxrpc_is_client_call(call) &&
 727                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 728                 /* request phase complete for this client call */
 729                 ret = -EPROTO;
 730         } else if (rxrpc_is_service_call(call) &&
 731                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 732                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 733                 /* Reply phase not begun or not complete for service call. */
 734                 ret = -EPROTO;
 735         } else {
 736                 ret = rxrpc_send_data(rx, call, msg, len, NULL);
 737         }
 738
 739 out_put_unlock:
 740         mutex_unlock(&call->user_mutex);
 741 error_put:
 742         rxrpc_put_call(call, rxrpc_call_put);
 743         _leave(" = %d", ret);
 744         return ret;
 745
 746 error_release_sock:
 747         release_sock(&rx->sk);
 748         return ret;
 749 }
 750
 751 /**
 752  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 753  * @sock: The socket the call is on
 754  * @call: The call to send data through
 755  * @msg: The data to send
 756  * @len: The amount of data to send
 757  * @notify_end_tx: Notification that the last packet is queued.
 758  *
 759  * Allow a kernel service to send data on a call.  The call must be in an state
 760  * appropriate to sending data.  No control data should be supplied in @msg,
 761  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 762  * more data to come, otherwise this data will end the transmission phase.
 763  */
 764 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 765                            struct msghdr *msg, size_t len,
 766                            rxrpc_notify_end_tx_t notify_end_tx)
 767 {
 768         int ret;
 769
 770         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 771
 772         ASSERTCMP(msg->msg_name, ==, NULL);
 773         ASSERTCMP(msg->msg_control, ==, NULL);
 774
 775         mutex_lock(&call->user_mutex);
 776
 777         _debug("CALL %d USR %lx ST %d on CONN %p",
 778                call->debug_id, call->user_call_ID, call->state, call->conn);
 779
 780         switch (READ_ONCE(call->state)) {
 781         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 782         case RXRPC_CALL_SERVER_ACK_REQUEST:
 783         case RXRPC_CALL_SERVER_SEND_REPLY:
 784                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 785                                       notify_end_tx);
 786                 break;
 787         case RXRPC_CALL_COMPLETE:
 788                 read_lock_bh(&call->state_lock);
 789                 ret = call->error;
 790                 read_unlock_bh(&call->state_lock);
 791                 break;
 792         default:
 793                 /* Request phase complete for this client call */
 794                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 795                 ret = -EPROTO;
 796                 break;
 797         }
 798
 799         mutex_unlock(&call->user_mutex);
 800         _leave(" = %d", ret);
 801         return ret;
 802 }
 803 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 804
 805 /**
 806  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 807  * @sock: The socket the call is on
 808  * @call: The call to be aborted
 809  * @abort_code: The abort code to stick into the ABORT packet
 810  * @error: Local error value
 811  * @why: 3-char string indicating why.
 812  *
 813  * Allow a kernel service to abort a call, if it's still in an abortable state
 814  * and return true if the call was aborted, false if it was already complete.
 815  */
 816 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 817                              u32 abort_code, int error, const char *why)
 818 {
 819         bool aborted;
 820
 821         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 822
 823         mutex_lock(&call->user_mutex);
 824
 825         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 826         if (aborted)
 827                 rxrpc_send_abort_packet(call);
 828
 829         mutex_unlock(&call->user_mutex);
 830         return aborted;
 831 }
 832 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 833
 834 /**
 835  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 836  * @sock: The socket the call is on
 837  * @call: The call to be informed
 838  * @tx_total_len: The amount of data to be transmitted for this call
 839  *
 840  * Allow a kernel service to set the total transmit length on a call.  This
 841  * allows buffer-to-packet encrypt-and-copy to be performed.
 842  *
 843  * This function is primarily for use for setting the reply length since the
 844  * request length can be set when beginning the call.
 845  */
 846 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 847                                 s64 tx_total_len)
 848 {
 849         WARN_ON(call->tx_total_len != -1);
 850         call->tx_total_len = tx_total_len;
 851 }
 852 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);