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  * Return true if there's sufficient Tx queue space.
  22  */
  23 static bool rxrpc_check_tx_space(struct rxrpc_call *call, rxrpc_seq_t *_tx_win)
  24 {
  25         unsigned int win_size =
  26                 min_t(unsigned int, call->tx_winsize,
  27                       call->cong_cwnd + call->cong_extra);
  28         rxrpc_seq_t tx_win = READ_ONCE(call->tx_hard_ack);
  29
  30         if (_tx_win)
  31                 *_tx_win = tx_win;
  32         return call->tx_top - tx_win < win_size;
  33 }
  34
  35 /*
  36  * Wait for space to appear in the Tx queue or a signal to occur.
  37  */
  38 static int rxrpc_wait_for_tx_window_intr(struct rxrpc_sock *rx,
  39                                          struct rxrpc_call *call,
  40                                          long *timeo)
  41 {
  42         for (;;) {
  43                 set_current_state(TASK_INTERRUPTIBLE);
  44                 if (rxrpc_check_tx_space(call, NULL))
  45                         return 0;
  46
  47                 if (call->state >= RXRPC_CALL_COMPLETE)
  48                         return call->error;
  49
  50                 if (signal_pending(current))
  51                         return sock_intr_errno(*timeo);
  52
  53                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  54                 *timeo = schedule_timeout(*timeo);
  55         }
  56 }
  57
  58 /*
  59  * Wait for space to appear in the Tx queue uninterruptibly, but with
  60  * a timeout of 2*RTT if no progress was made and a signal occurred.
  61  */
  62 static int rxrpc_wait_for_tx_window_waitall(struct rxrpc_sock *rx,
  63                                             struct rxrpc_call *call)
  64 {
  65         rxrpc_seq_t tx_start, tx_win;
  66         signed long rtt, timeout;
  67
  68         rtt = READ_ONCE(call->peer->srtt_us) >> 3;
  69         rtt = usecs_to_jiffies(rtt) * 2;
  70         if (rtt < 2)
  71                 rtt = 2;
  72
  73         timeout = rtt;
  74         tx_start = READ_ONCE(call->tx_hard_ack);
  75
  76         for (;;) {
  77                 set_current_state(TASK_UNINTERRUPTIBLE);
  78
  79                 tx_win = READ_ONCE(call->tx_hard_ack);
  80                 if (rxrpc_check_tx_space(call, &tx_win))
  81                         return 0;
  82
  83                 if (call->state >= RXRPC_CALL_COMPLETE)
  84                         return call->error;
  85
  86                 if (timeout == 0 &&
  87                     tx_win == tx_start && signal_pending(current))
  88                         return -EINTR;
  89
  90                 if (tx_win != tx_start) {
  91                         timeout = rtt;
  92                         tx_start = tx_win;
  93                 }
  94
  95                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  96                 timeout = schedule_timeout(timeout);
  97         }
  98 }
  99
 100 /*
 101  * Wait for space to appear in the Tx queue uninterruptibly.
 102  */
 103 static int rxrpc_wait_for_tx_window_nonintr(struct rxrpc_sock *rx,
 104                                             struct rxrpc_call *call,
 105                                             long *timeo)
 106 {
 107         for (;;) {
 108                 set_current_state(TASK_UNINTERRUPTIBLE);
 109                 if (rxrpc_check_tx_space(call, NULL))
 110                         return 0;
 111
 112                 if (call->state >= RXRPC_CALL_COMPLETE)
 113                         return call->error;
 114
 115                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
 116                 *timeo = schedule_timeout(*timeo);
 117         }
 118 }
 119
 120 /*
 121  * wait for space to appear in the transmit/ACK window
 122  * - caller holds the socket locked
 123  */
 124 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 125                                     struct rxrpc_call *call,
 126                                     long *timeo,
 127                                     bool waitall)
 128 {
 129         DECLARE_WAITQUEUE(myself, current);
 130         int ret;
 131
 132         _enter(",{%u,%u,%u}",
 133                call->tx_hard_ack, call->tx_top, call->tx_winsize);
 134
 135         add_wait_queue(&call->waitq, &myself);
 136
 137         switch (call->interruptibility) {
 138         case RXRPC_INTERRUPTIBLE:
 139                 if (waitall)
 140                         ret = rxrpc_wait_for_tx_window_waitall(rx, call);
 141                 else
 142                         ret = rxrpc_wait_for_tx_window_intr(rx, call, timeo);
 143                 break;
 144         case RXRPC_PREINTERRUPTIBLE:
 145         case RXRPC_UNINTERRUPTIBLE:
 146         default:
 147                 ret = rxrpc_wait_for_tx_window_nonintr(rx, call, timeo);
 148                 break;
 149         }
 150
 151         remove_wait_queue(&call->waitq, &myself);
 152         set_current_state(TASK_RUNNING);
 153         _leave(" = %d", ret);
 154         return ret;
 155 }
 156
 157 /*
 158  * Schedule an instant Tx resend.
 159  */
 160 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
 161 {
 162         spin_lock_bh(&call->lock);
 163
 164         if (call->state < RXRPC_CALL_COMPLETE) {
 165                 call->rxtx_annotations[ix] =
 166                         (call->rxtx_annotations[ix] & RXRPC_TX_ANNO_LAST) |
 167                         RXRPC_TX_ANNO_RETRANS;
 168                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
 169                         rxrpc_queue_call(call);
 170         }
 171
 172         spin_unlock_bh(&call->lock);
 173 }
 174
 175 /*
 176  * Notify the owner of the call that the transmit phase is ended and the last
 177  * packet has been queued.
 178  */
 179 static void rxrpc_notify_end_tx(struct rxrpc_sock *rx, struct rxrpc_call *call,
 180                                 rxrpc_notify_end_tx_t notify_end_tx)
 181 {
 182         if (notify_end_tx)
 183                 notify_end_tx(&rx->sk, call, call->user_call_ID);
 184 }
 185
 186 /*
 187  * Queue a DATA packet for transmission, set the resend timeout and send
 188  * the packet immediately.  Returns the error from rxrpc_send_data_packet()
 189  * in case the caller wants to do something with it.
 190  */
 191 static int rxrpc_queue_packet(struct rxrpc_sock *rx, struct rxrpc_call *call,
 192                               struct sk_buff *skb, bool last,
 193                               rxrpc_notify_end_tx_t notify_end_tx)
 194 {
 195         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 196         unsigned long now;
 197         rxrpc_seq_t seq = sp->hdr.seq;
 198         int ret, ix;
 199         u8 annotation = RXRPC_TX_ANNO_UNACK;
 200
 201         _net("queue skb %p [%d]", skb, seq);
 202
 203         ASSERTCMP(seq, ==, call->tx_top + 1);
 204
 205         if (last)
 206                 annotation |= RXRPC_TX_ANNO_LAST;
 207
 208         /* We have to set the timestamp before queueing as the retransmit
 209          * algorithm can see the packet as soon as we queue it.
 210          */
 211         skb->tstamp = ktime_get_real();
 212
 213         ix = seq & RXRPC_RXTX_BUFF_MASK;
 214         rxrpc_get_skb(skb, rxrpc_skb_got);
 215         call->rxtx_annotations[ix] = annotation;
 216         smp_wmb();
 217         call->rxtx_buffer[ix] = skb;
 218         call->tx_top = seq;
 219         if (last)
 220                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 221         else
 222                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 223
 224         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 225                 _debug("________awaiting reply/ACK__________");
 226                 write_lock_bh(&call->state_lock);
 227                 switch (call->state) {
 228                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 229                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 230                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 231                         break;
 232                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 233                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 234                         now = jiffies;
 235                         WRITE_ONCE(call->ack_at, now + MAX_JIFFY_OFFSET);
 236                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 237                                 call->ackr_reason = 0;
 238                         trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
 239                         if (!last)
 240                                 break;
 241                         fallthrough;
 242                 case RXRPC_CALL_SERVER_SEND_REPLY:
 243                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 244                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 245                         break;
 246                 default:
 247                         break;
 248                 }
 249                 write_unlock_bh(&call->state_lock);
 250         }
 251
 252         if (seq == 1 && rxrpc_is_client_call(call))
 253                 rxrpc_expose_client_call(call);
 254
 255         ret = rxrpc_send_data_packet(call, skb, false);
 256         if (ret < 0) {
 257                 switch (ret) {
 258                 case -ENETUNREACH:
 259                 case -EHOSTUNREACH:
 260                 case -ECONNREFUSED:
 261                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 262                                                   0, ret);
 263                         goto out;
 264                 }
 265                 _debug("need instant resend %d", ret);
 266                 rxrpc_instant_resend(call, ix);
 267         } else {
 268                 unsigned long now = jiffies;
 269                 unsigned long resend_at = now + call->peer->rto_j;
 270
 271                 WRITE_ONCE(call->resend_at, resend_at);
 272                 rxrpc_reduce_call_timer(call, resend_at, now,
 273                                         rxrpc_timer_set_for_send);
 274         }
 275
 276 out:
 277         rxrpc_free_skb(skb, rxrpc_skb_freed);
 278         _leave(" = %d", ret);
 279         return ret;
 280 }
 281
 282 /*
 283  * send data through a socket
 284  * - must be called in process context
 285  * - The caller holds the call user access mutex, but not the socket lock.
 286  */
 287 static int rxrpc_send_data(struct rxrpc_sock *rx,
 288                            struct rxrpc_call *call,
 289                            struct msghdr *msg, size_t len,
 290                            rxrpc_notify_end_tx_t notify_end_tx,
 291                            bool *_dropped_lock)
 292 {
 293         struct rxrpc_skb_priv *sp;
 294         struct sk_buff *skb;
 295         struct sock *sk = &rx->sk;
 296         enum rxrpc_call_state state;
 297         long timeo;
 298         bool more = msg->msg_flags & MSG_MORE;
 299         int ret, copied = 0;
 300
 301         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 302
 303         /* this should be in poll */
 304         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 305
 306 reload:
 307         ret = -EPIPE;
 308         if (sk->sk_shutdown & SEND_SHUTDOWN)
 309                 goto maybe_error;
 310         state = READ_ONCE(call->state);
 311         ret = -ESHUTDOWN;
 312         if (state >= RXRPC_CALL_COMPLETE)
 313                 goto maybe_error;
 314         ret = -EPROTO;
 315         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 316             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 317             state != RXRPC_CALL_SERVER_SEND_REPLY)
 318                 goto maybe_error;
 319
 320         ret = -EMSGSIZE;
 321         if (call->tx_total_len != -1) {
 322                 if (len - copied > call->tx_total_len)
 323                         goto maybe_error;
 324                 if (!more && len - copied != call->tx_total_len)
 325                         goto maybe_error;
 326         }
 327
 328         skb = call->tx_pending;
 329         call->tx_pending = NULL;
 330         rxrpc_see_skb(skb, rxrpc_skb_seen);
 331
 332         do {
 333                 /* Check to see if there's a ping ACK to reply to. */
 334                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 335                         rxrpc_send_ack_packet(call, false, NULL);
 336
 337                 if (!skb) {
 338                         size_t remain, bufsize, chunk, offset;
 339
 340                         _debug("alloc");
 341
 342                         if (!rxrpc_check_tx_space(call, NULL))
 343                                 goto wait_for_space;
 344
 345                         /* Work out the maximum size of a packet.  Assume that
 346                          * the security header is going to be in the padded
 347                          * region (enc blocksize), but the trailer is not.
 348                          */
 349                         remain = more ? INT_MAX : msg_data_left(msg);
 350                         ret = call->conn->security->how_much_data(call, remain,
 351                                                                   &bufsize, &chunk, &offset);
 352                         if (ret < 0)
 353                                 goto maybe_error;
 354
 355                         _debug("SIZE: %zu/%zu @%zu", chunk, bufsize, offset);
 356
 357                         /* create a buffer that we can retain until it's ACK'd */
 358                         skb = sock_alloc_send_skb(
 359                                 sk, bufsize, msg->msg_flags & MSG_DONTWAIT, &ret);
 360                         if (!skb)
 361                                 goto maybe_error;
 362
 363                         sp = rxrpc_skb(skb);
 364                         sp->rx_flags |= RXRPC_SKB_TX_BUFFER;
 365                         rxrpc_new_skb(skb, rxrpc_skb_new);
 366
 367                         _debug("ALLOC SEND %p", skb);
 368
 369                         ASSERTCMP(skb->mark, ==, 0);
 370
 371                         __skb_put(skb, offset);
 372
 373                         sp->remain = chunk;
 374                         if (sp->remain > skb_tailroom(skb))
 375                                 sp->remain = skb_tailroom(skb);
 376
 377                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 378                                skb_headroom(skb),
 379                                skb_tailroom(skb),
 380                                skb_headlen(skb),
 381                                sp->remain);
 382
 383                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 384                 }
 385
 386                 _debug("append");
 387                 sp = rxrpc_skb(skb);
 388
 389                 /* append next segment of data to the current buffer */
 390                 if (msg_data_left(msg) > 0) {
 391                         int copy = skb_tailroom(skb);
 392                         ASSERTCMP(copy, >, 0);
 393                         if (copy > msg_data_left(msg))
 394                                 copy = msg_data_left(msg);
 395                         if (copy > sp->remain)
 396                                 copy = sp->remain;
 397
 398                         _debug("add");
 399                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 400                         _debug("added");
 401                         if (ret < 0)
 402                                 goto efault;
 403                         sp->remain -= copy;
 404                         skb->mark += copy;
 405                         copied += copy;
 406                         if (call->tx_total_len != -1)
 407                                 call->tx_total_len -= copy;
 408                 }
 409
 410                 /* check for the far side aborting the call or a network error
 411                  * occurring */
 412                 if (call->state == RXRPC_CALL_COMPLETE)
 413                         goto call_terminated;
 414
 415                 /* add the packet to the send queue if it's now full */
 416                 if (sp->remain <= 0 ||
 417                     (msg_data_left(msg) == 0 && !more)) {
 418                         struct rxrpc_connection *conn = call->conn;
 419                         uint32_t seq;
 420
 421                         seq = call->tx_top + 1;
 422
 423                         sp->hdr.seq     = seq;
 424                         sp->hdr._rsvd   = 0;
 425                         sp->hdr.flags   = conn->out_clientflag;
 426
 427                         if (msg_data_left(msg) == 0 && !more)
 428                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 429                         else if (call->tx_top - call->tx_hard_ack <
 430                                  call->tx_winsize)
 431                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 432
 433                         ret = call->security->secure_packet(call, skb, skb->mark);
 434                         if (ret < 0)
 435                                 goto out;
 436
 437                         ret = rxrpc_queue_packet(rx, call, skb,
 438                                                  !msg_data_left(msg) && !more,
 439                                                  notify_end_tx);
 440                         /* Should check for failure here */
 441                         skb = NULL;
 442                 }
 443         } while (msg_data_left(msg) > 0);
 444
 445 success:
 446         ret = copied;
 447         if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
 448                 read_lock_bh(&call->state_lock);
 449                 if (call->error < 0)
 450                         ret = call->error;
 451                 read_unlock_bh(&call->state_lock);
 452         }
 453 out:
 454         call->tx_pending = skb;
 455         _leave(" = %d", ret);
 456         return ret;
 457
 458 call_terminated:
 459         rxrpc_free_skb(skb, rxrpc_skb_freed);
 460         _leave(" = %d", call->error);
 461         return call->error;
 462
 463 maybe_error:
 464         if (copied)
 465                 goto success;
 466         goto out;
 467
 468 efault:
 469         ret = -EFAULT;
 470         goto out;
 471
 472 wait_for_space:
 473         ret = -EAGAIN;
 474         if (msg->msg_flags & MSG_DONTWAIT)
 475                 goto maybe_error;
 476         mutex_unlock(&call->user_mutex);
 477         *_dropped_lock = true;
 478         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
 479                                        msg->msg_flags & MSG_WAITALL);
 480         if (ret < 0)
 481                 goto maybe_error;
 482         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
 483                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 484                         ret = sock_intr_errno(timeo);
 485                         goto maybe_error;
 486                 }
 487         } else {
 488                 mutex_lock(&call->user_mutex);
 489         }
 490         *_dropped_lock = false;
 491         goto reload;
 492 }
 493
 494 /*
 495  * extract control messages from the sendmsg() control buffer
 496  */
 497 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 498 {
 499         struct cmsghdr *cmsg;
 500         bool got_user_ID = false;
 501         int len;
 502
 503         if (msg->msg_controllen == 0)
 504                 return -EINVAL;
 505
 506         for_each_cmsghdr(cmsg, msg) {
 507                 if (!CMSG_OK(msg, cmsg))
 508                         return -EINVAL;
 509
 510                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 511                 _debug("CMSG %d, %d, %d",
 512                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 513
 514                 if (cmsg->cmsg_level != SOL_RXRPC)
 515                         continue;
 516
 517                 switch (cmsg->cmsg_type) {
 518                 case RXRPC_USER_CALL_ID:
 519                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 520                                 if (len != sizeof(u32))
 521                                         return -EINVAL;
 522                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 523                         } else {
 524                                 if (len != sizeof(unsigned long))
 525                                         return -EINVAL;
 526                                 p->call.user_call_ID = *(unsigned long *)
 527                                         CMSG_DATA(cmsg);
 528                         }
 529                         got_user_ID = true;
 530                         break;
 531
 532                 case RXRPC_ABORT:
 533                         if (p->command != RXRPC_CMD_SEND_DATA)
 534                                 return -EINVAL;
 535                         p->command = RXRPC_CMD_SEND_ABORT;
 536                         if (len != sizeof(p->abort_code))
 537                                 return -EINVAL;
 538                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 539                         if (p->abort_code == 0)
 540                                 return -EINVAL;
 541                         break;
 542
 543                 case RXRPC_CHARGE_ACCEPT:
 544                         if (p->command != RXRPC_CMD_SEND_DATA)
 545                                 return -EINVAL;
 546                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
 547                         if (len != 0)
 548                                 return -EINVAL;
 549                         break;
 550
 551                 case RXRPC_EXCLUSIVE_CALL:
 552                         p->exclusive = true;
 553                         if (len != 0)
 554                                 return -EINVAL;
 555                         break;
 556
 557                 case RXRPC_UPGRADE_SERVICE:
 558                         p->upgrade = true;
 559                         if (len != 0)
 560                                 return -EINVAL;
 561                         break;
 562
 563                 case RXRPC_TX_LENGTH:
 564                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 565                                 return -EINVAL;
 566                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 567                         if (p->call.tx_total_len < 0)
 568                                 return -EINVAL;
 569                         break;
 570
 571                 case RXRPC_SET_CALL_TIMEOUT:
 572                         if (len & 3 || len < 4 || len > 12)
 573                                 return -EINVAL;
 574                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 575                         p->call.nr_timeouts = len / 4;
 576                         if (p->call.timeouts.hard > INT_MAX / HZ)
 577                                 return -ERANGE;
 578                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 579                                 return -ERANGE;
 580                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 581                                 return -ERANGE;
 582                         break;
 583
 584                 default:
 585                         return -EINVAL;
 586                 }
 587         }
 588
 589         if (!got_user_ID)
 590                 return -EINVAL;
 591         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 592                 return -EINVAL;
 593         _leave(" = 0");
 594         return 0;
 595 }
 596
 597 /*
 598  * Create a new client call for sendmsg().
 599  * - Called with the socket lock held, which it must release.
 600  * - If it returns a call, the call's lock will need releasing by the caller.
 601  */
 602 static struct rxrpc_call *
 603 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 604                                   struct rxrpc_send_params *p)
 605         __releases(&rx->sk.sk_lock.slock)
 606         __acquires(&call->user_mutex)
 607 {
 608         struct rxrpc_conn_parameters cp;
 609         struct rxrpc_call *call;
 610         struct key *key;
 611
 612         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 613
 614         _enter("");
 615
 616         if (!msg->msg_name) {
 617                 release_sock(&rx->sk);
 618                 return ERR_PTR(-EDESTADDRREQ);
 619         }
 620
 621         key = rx->key;
 622         if (key && !rx->key->payload.data[0])
 623                 key = NULL;
 624
 625         memset(&cp, 0, sizeof(cp));
 626         cp.local                = rx->local;
 627         cp.key                  = rx->key;
 628         cp.security_level       = rx->min_sec_level;
 629         cp.exclusive            = rx->exclusive | p->exclusive;
 630         cp.upgrade              = p->upgrade;
 631         cp.service_id           = srx->srx_service;
 632         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 633                                      atomic_inc_return(&rxrpc_debug_id));
 634         /* The socket is now unlocked */
 635
 636         rxrpc_put_peer(cp.peer);
 637         _leave(" = %p\n", call);
 638         return call;
 639 }
 640
 641 /*
 642  * send a message forming part of a client call through an RxRPC socket
 643  * - caller holds the socket locked
 644  * - the socket may be either a client socket or a server socket
 645  */
 646 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 647         __releases(&rx->sk.sk_lock.slock)
 648         __releases(&call->user_mutex)
 649 {
 650         enum rxrpc_call_state state;
 651         struct rxrpc_call *call;
 652         unsigned long now, j;
 653         bool dropped_lock = false;
 654         int ret;
 655
 656         struct rxrpc_send_params p = {
 657                 .call.tx_total_len      = -1,
 658                 .call.user_call_ID      = 0,
 659                 .call.nr_timeouts       = 0,
 660                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
 661                 .abort_code             = 0,
 662                 .command                = RXRPC_CMD_SEND_DATA,
 663                 .exclusive              = false,
 664                 .upgrade                = false,
 665         };
 666
 667         _enter("");
 668
 669         ret = rxrpc_sendmsg_cmsg(msg, &p);
 670         if (ret < 0)
 671                 goto error_release_sock;
 672
 673         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
 674                 ret = -EINVAL;
 675                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 676                         goto error_release_sock;
 677                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
 678                 goto error_release_sock;
 679         }
 680
 681         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 682         if (!call) {
 683                 ret = -EBADSLT;
 684                 if (p.command != RXRPC_CMD_SEND_DATA)
 685                         goto error_release_sock;
 686                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 687                 /* The socket is now unlocked... */
 688                 if (IS_ERR(call))
 689                         return PTR_ERR(call);
 690                 /* ... and we have the call lock. */
 691                 ret = 0;
 692                 if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
 693                         goto out_put_unlock;
 694         } else {
 695                 switch (READ_ONCE(call->state)) {
 696                 case RXRPC_CALL_UNINITIALISED:
 697                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 698                 case RXRPC_CALL_SERVER_PREALLOC:
 699                 case RXRPC_CALL_SERVER_SECURING:
 700                         rxrpc_put_call(call, rxrpc_call_put);
 701                         ret = -EBUSY;
 702                         goto error_release_sock;
 703                 default:
 704                         break;
 705                 }
 706
 707                 ret = mutex_lock_interruptible(&call->user_mutex);
 708                 release_sock(&rx->sk);
 709                 if (ret < 0) {
 710                         ret = -ERESTARTSYS;
 711                         goto error_put;
 712                 }
 713
 714                 if (p.call.tx_total_len != -1) {
 715                         ret = -EINVAL;
 716                         if (call->tx_total_len != -1 ||
 717                             call->tx_pending ||
 718                             call->tx_top != 0)
 719                                 goto out_put_unlock;
 720                         call->tx_total_len = p.call.tx_total_len;
 721                 }
 722         }
 723
 724         switch (p.call.nr_timeouts) {
 725         case 3:
 726                 j = msecs_to_jiffies(p.call.timeouts.normal);
 727                 if (p.call.timeouts.normal > 0 && j == 0)
 728                         j = 1;
 729                 WRITE_ONCE(call->next_rx_timo, j);
 730                 fallthrough;
 731         case 2:
 732                 j = msecs_to_jiffies(p.call.timeouts.idle);
 733                 if (p.call.timeouts.idle > 0 && j == 0)
 734                         j = 1;
 735                 WRITE_ONCE(call->next_req_timo, j);
 736                 fallthrough;
 737         case 1:
 738                 if (p.call.timeouts.hard > 0) {
 739                         j = p.call.timeouts.hard * HZ;
 740                         now = jiffies;
 741                         j += now;
 742                         WRITE_ONCE(call->expect_term_by, j);
 743                         rxrpc_reduce_call_timer(call, j, now,
 744                                                 rxrpc_timer_set_for_hard);
 745                 }
 746                 break;
 747         }
 748
 749         state = READ_ONCE(call->state);
 750         _debug("CALL %d USR %lx ST %d on CONN %p",
 751                call->debug_id, call->user_call_ID, state, call->conn);
 752
 753         if (state >= RXRPC_CALL_COMPLETE) {
 754                 /* it's too late for this call */
 755                 ret = -ESHUTDOWN;
 756         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 757                 ret = 0;
 758                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 759                         ret = rxrpc_send_abort_packet(call);
 760         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 761                 ret = -EINVAL;
 762         } else {
 763                 ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
 764         }
 765
 766 out_put_unlock:
 767         if (!dropped_lock)
 768                 mutex_unlock(&call->user_mutex);
 769 error_put:
 770         rxrpc_put_call(call, rxrpc_call_put);
 771         _leave(" = %d", ret);
 772         return ret;
 773
 774 error_release_sock:
 775         release_sock(&rx->sk);
 776         return ret;
 777 }
 778
 779 /**
 780  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 781  * @sock: The socket the call is on
 782  * @call: The call to send data through
 783  * @msg: The data to send
 784  * @len: The amount of data to send
 785  * @notify_end_tx: Notification that the last packet is queued.
 786  *
 787  * Allow a kernel service to send data on a call.  The call must be in an state
 788  * appropriate to sending data.  No control data should be supplied in @msg,
 789  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 790  * more data to come, otherwise this data will end the transmission phase.
 791  */
 792 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 793                            struct msghdr *msg, size_t len,
 794                            rxrpc_notify_end_tx_t notify_end_tx)
 795 {
 796         bool dropped_lock = false;
 797         int ret;
 798
 799         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 800
 801         ASSERTCMP(msg->msg_name, ==, NULL);
 802         ASSERTCMP(msg->msg_control, ==, NULL);
 803
 804         mutex_lock(&call->user_mutex);
 805
 806         _debug("CALL %d USR %lx ST %d on CONN %p",
 807                call->debug_id, call->user_call_ID, call->state, call->conn);
 808
 809         switch (READ_ONCE(call->state)) {
 810         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 811         case RXRPC_CALL_SERVER_ACK_REQUEST:
 812         case RXRPC_CALL_SERVER_SEND_REPLY:
 813                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 814                                       notify_end_tx, &dropped_lock);
 815                 break;
 816         case RXRPC_CALL_COMPLETE:
 817                 read_lock_bh(&call->state_lock);
 818                 ret = call->error;
 819                 read_unlock_bh(&call->state_lock);
 820                 break;
 821         default:
 822                 /* Request phase complete for this client call */
 823                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 824                 ret = -EPROTO;
 825                 break;
 826         }
 827
 828         if (!dropped_lock)
 829                 mutex_unlock(&call->user_mutex);
 830         _leave(" = %d", ret);
 831         return ret;
 832 }
 833 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 834
 835 /**
 836  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 837  * @sock: The socket the call is on
 838  * @call: The call to be aborted
 839  * @abort_code: The abort code to stick into the ABORT packet
 840  * @error: Local error value
 841  * @why: 3-char string indicating why.
 842  *
 843  * Allow a kernel service to abort a call, if it's still in an abortable state
 844  * and return true if the call was aborted, false if it was already complete.
 845  */
 846 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 847                              u32 abort_code, int error, const char *why)
 848 {
 849         bool aborted;
 850
 851         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 852
 853         mutex_lock(&call->user_mutex);
 854
 855         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 856         if (aborted)
 857                 rxrpc_send_abort_packet(call);
 858
 859         mutex_unlock(&call->user_mutex);
 860         return aborted;
 861 }
 862 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 863
 864 /**
 865  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 866  * @sock: The socket the call is on
 867  * @call: The call to be informed
 868  * @tx_total_len: The amount of data to be transmitted for this call
 869  *
 870  * Allow a kernel service to set the total transmit length on a call.  This
 871  * allows buffer-to-packet encrypt-and-copy to be performed.
 872  *
 873  * This function is primarily for use for setting the reply length since the
 874  * request length can be set when beginning the call.
 875  */
 876 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 877                                 s64 tx_total_len)
 878 {
 879         WARN_ON(call->tx_total_len != -1);
 880         call->tx_total_len = tx_total_len;
 881 }
 882 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);