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         rxrpc_inc_stat(call->rxnet, stat_tx_data);
 204
 205         ASSERTCMP(seq, ==, call->tx_top + 1);
 206
 207         if (last)
 208                 annotation |= RXRPC_TX_ANNO_LAST;
 209
 210         /* We have to set the timestamp before queueing as the retransmit
 211          * algorithm can see the packet as soon as we queue it.
 212          */
 213         skb->tstamp = ktime_get_real();
 214
 215         ix = seq & RXRPC_RXTX_BUFF_MASK;
 216         rxrpc_get_skb(skb, rxrpc_skb_got);
 217         call->rxtx_annotations[ix] = annotation;
 218         smp_wmb();
 219         call->rxtx_buffer[ix] = skb;
 220         call->tx_top = seq;
 221         if (last)
 222                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 223         else
 224                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 225
 226         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 227                 _debug("________awaiting reply/ACK__________");
 228                 write_lock_bh(&call->state_lock);
 229                 switch (call->state) {
 230                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 231                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 232                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 233                         break;
 234                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 235                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 236                         now = jiffies;
 237                         WRITE_ONCE(call->delay_ack_at, now + MAX_JIFFY_OFFSET);
 238                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 239                                 call->ackr_reason = 0;
 240                         trace_rxrpc_timer(call, rxrpc_timer_init_for_send_reply, now);
 241                         if (!last)
 242                                 break;
 243                         fallthrough;
 244                 case RXRPC_CALL_SERVER_SEND_REPLY:
 245                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 246                         rxrpc_notify_end_tx(rx, call, notify_end_tx);
 247                         break;
 248                 default:
 249                         break;
 250                 }
 251                 write_unlock_bh(&call->state_lock);
 252         }
 253
 254         if (seq == 1 && rxrpc_is_client_call(call))
 255                 rxrpc_expose_client_call(call);
 256
 257         ret = rxrpc_send_data_packet(call, skb, false);
 258         if (ret < 0) {
 259                 switch (ret) {
 260                 case -ENETUNREACH:
 261                 case -EHOSTUNREACH:
 262                 case -ECONNREFUSED:
 263                         rxrpc_set_call_completion(call, RXRPC_CALL_LOCAL_ERROR,
 264                                                   0, ret);
 265                         goto out;
 266                 }
 267                 _debug("need instant resend %d", ret);
 268                 rxrpc_instant_resend(call, ix);
 269         } else {
 270                 unsigned long now = jiffies;
 271                 unsigned long resend_at = now + call->peer->rto_j;
 272
 273                 WRITE_ONCE(call->resend_at, resend_at);
 274                 rxrpc_reduce_call_timer(call, resend_at, now,
 275                                         rxrpc_timer_set_for_send);
 276         }
 277
 278 out:
 279         rxrpc_free_skb(skb, rxrpc_skb_freed);
 280         _leave(" = %d", ret);
 281         return ret;
 282 }
 283
 284 /*
 285  * send data through a socket
 286  * - must be called in process context
 287  * - The caller holds the call user access mutex, but not the socket lock.
 288  */
 289 static int rxrpc_send_data(struct rxrpc_sock *rx,
 290                            struct rxrpc_call *call,
 291                            struct msghdr *msg, size_t len,
 292                            rxrpc_notify_end_tx_t notify_end_tx,
 293                            bool *_dropped_lock)
 294 {
 295         struct rxrpc_skb_priv *sp;
 296         struct sk_buff *skb;
 297         struct sock *sk = &rx->sk;
 298         enum rxrpc_call_state state;
 299         long timeo;
 300         bool more = msg->msg_flags & MSG_MORE;
 301         int ret, copied = 0;
 302
 303         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 304
 305         /* this should be in poll */
 306         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 307
 308 reload:
 309         ret = -EPIPE;
 310         if (sk->sk_shutdown & SEND_SHUTDOWN)
 311                 goto maybe_error;
 312         state = READ_ONCE(call->state);
 313         ret = -ESHUTDOWN;
 314         if (state >= RXRPC_CALL_COMPLETE)
 315                 goto maybe_error;
 316         ret = -EPROTO;
 317         if (state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 318             state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 319             state != RXRPC_CALL_SERVER_SEND_REPLY)
 320                 goto maybe_error;
 321
 322         ret = -EMSGSIZE;
 323         if (call->tx_total_len != -1) {
 324                 if (len - copied > call->tx_total_len)
 325                         goto maybe_error;
 326                 if (!more && len - copied != call->tx_total_len)
 327                         goto maybe_error;
 328         }
 329
 330         skb = call->tx_pending;
 331         call->tx_pending = NULL;
 332         rxrpc_see_skb(skb, rxrpc_skb_seen);
 333
 334         do {
 335                 rxrpc_transmit_ack_packets(call->peer->local);
 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                         rxrpc_new_skb(skb, rxrpc_skb_new);
 365
 366                         _debug("ALLOC SEND %p", skb);
 367
 368                         ASSERTCMP(skb->mark, ==, 0);
 369
 370                         __skb_put(skb, offset);
 371
 372                         sp->remain = chunk;
 373                         if (sp->remain > skb_tailroom(skb))
 374                                 sp->remain = skb_tailroom(skb);
 375
 376                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 377                                skb_headroom(skb),
 378                                skb_tailroom(skb),
 379                                skb_headlen(skb),
 380                                sp->remain);
 381
 382                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 383                 }
 384
 385                 _debug("append");
 386                 sp = rxrpc_skb(skb);
 387
 388                 /* append next segment of data to the current buffer */
 389                 if (msg_data_left(msg) > 0) {
 390                         int copy = skb_tailroom(skb);
 391                         ASSERTCMP(copy, >, 0);
 392                         if (copy > msg_data_left(msg))
 393                                 copy = msg_data_left(msg);
 394                         if (copy > sp->remain)
 395                                 copy = sp->remain;
 396
 397                         _debug("add");
 398                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 399                         _debug("added");
 400                         if (ret < 0)
 401                                 goto efault;
 402                         sp->remain -= copy;
 403                         skb->mark += copy;
 404                         copied += copy;
 405                         if (call->tx_total_len != -1)
 406                                 call->tx_total_len -= copy;
 407                 }
 408
 409                 /* check for the far side aborting the call or a network error
 410                  * occurring */
 411                 if (call->state == RXRPC_CALL_COMPLETE)
 412                         goto call_terminated;
 413
 414                 /* add the packet to the send queue if it's now full */
 415                 if (sp->remain <= 0 ||
 416                     (msg_data_left(msg) == 0 && !more)) {
 417                         struct rxrpc_connection *conn = call->conn;
 418                         uint32_t seq;
 419
 420                         seq = call->tx_top + 1;
 421
 422                         sp->hdr.seq     = seq;
 423                         sp->hdr._rsvd   = 0;
 424                         sp->hdr.flags   = conn->out_clientflag;
 425
 426                         if (msg_data_left(msg) == 0 && !more)
 427                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 428                         else if (call->tx_top - call->tx_hard_ack <
 429                                  call->tx_winsize)
 430                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 431
 432                         ret = call->security->secure_packet(call, skb, skb->mark);
 433                         if (ret < 0)
 434                                 goto out;
 435
 436                         ret = rxrpc_queue_packet(rx, call, skb,
 437                                                  !msg_data_left(msg) && !more,
 438                                                  notify_end_tx);
 439                         /* Should check for failure here */
 440                         skb = NULL;
 441                 }
 442         } while (msg_data_left(msg) > 0);
 443
 444 success:
 445         ret = copied;
 446         if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE) {
 447                 read_lock_bh(&call->state_lock);
 448                 if (call->error < 0)
 449                         ret = call->error;
 450                 read_unlock_bh(&call->state_lock);
 451         }
 452 out:
 453         call->tx_pending = skb;
 454         _leave(" = %d", ret);
 455         return ret;
 456
 457 call_terminated:
 458         rxrpc_free_skb(skb, rxrpc_skb_freed);
 459         _leave(" = %d", call->error);
 460         return call->error;
 461
 462 maybe_error:
 463         if (copied)
 464                 goto success;
 465         goto out;
 466
 467 efault:
 468         ret = -EFAULT;
 469         goto out;
 470
 471 wait_for_space:
 472         ret = -EAGAIN;
 473         if (msg->msg_flags & MSG_DONTWAIT)
 474                 goto maybe_error;
 475         mutex_unlock(&call->user_mutex);
 476         *_dropped_lock = true;
 477         ret = rxrpc_wait_for_tx_window(rx, call, &timeo,
 478                                        msg->msg_flags & MSG_WAITALL);
 479         if (ret < 0)
 480                 goto maybe_error;
 481         if (call->interruptibility == RXRPC_INTERRUPTIBLE) {
 482                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
 483                         ret = sock_intr_errno(timeo);
 484                         goto maybe_error;
 485                 }
 486         } else {
 487                 mutex_lock(&call->user_mutex);
 488         }
 489         *_dropped_lock = false;
 490         goto reload;
 491 }
 492
 493 /*
 494  * extract control messages from the sendmsg() control buffer
 495  */
 496 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 497 {
 498         struct cmsghdr *cmsg;
 499         bool got_user_ID = false;
 500         int len;
 501
 502         if (msg->msg_controllen == 0)
 503                 return -EINVAL;
 504
 505         for_each_cmsghdr(cmsg, msg) {
 506                 if (!CMSG_OK(msg, cmsg))
 507                         return -EINVAL;
 508
 509                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 510                 _debug("CMSG %d, %d, %d",
 511                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 512
 513                 if (cmsg->cmsg_level != SOL_RXRPC)
 514                         continue;
 515
 516                 switch (cmsg->cmsg_type) {
 517                 case RXRPC_USER_CALL_ID:
 518                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 519                                 if (len != sizeof(u32))
 520                                         return -EINVAL;
 521                                 p->call.user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 522                         } else {
 523                                 if (len != sizeof(unsigned long))
 524                                         return -EINVAL;
 525                                 p->call.user_call_ID = *(unsigned long *)
 526                                         CMSG_DATA(cmsg);
 527                         }
 528                         got_user_ID = true;
 529                         break;
 530
 531                 case RXRPC_ABORT:
 532                         if (p->command != RXRPC_CMD_SEND_DATA)
 533                                 return -EINVAL;
 534                         p->command = RXRPC_CMD_SEND_ABORT;
 535                         if (len != sizeof(p->abort_code))
 536                                 return -EINVAL;
 537                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 538                         if (p->abort_code == 0)
 539                                 return -EINVAL;
 540                         break;
 541
 542                 case RXRPC_CHARGE_ACCEPT:
 543                         if (p->command != RXRPC_CMD_SEND_DATA)
 544                                 return -EINVAL;
 545                         p->command = RXRPC_CMD_CHARGE_ACCEPT;
 546                         if (len != 0)
 547                                 return -EINVAL;
 548                         break;
 549
 550                 case RXRPC_EXCLUSIVE_CALL:
 551                         p->exclusive = true;
 552                         if (len != 0)
 553                                 return -EINVAL;
 554                         break;
 555
 556                 case RXRPC_UPGRADE_SERVICE:
 557                         p->upgrade = true;
 558                         if (len != 0)
 559                                 return -EINVAL;
 560                         break;
 561
 562                 case RXRPC_TX_LENGTH:
 563                         if (p->call.tx_total_len != -1 || len != sizeof(__s64))
 564                                 return -EINVAL;
 565                         p->call.tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 566                         if (p->call.tx_total_len < 0)
 567                                 return -EINVAL;
 568                         break;
 569
 570                 case RXRPC_SET_CALL_TIMEOUT:
 571                         if (len & 3 || len < 4 || len > 12)
 572                                 return -EINVAL;
 573                         memcpy(&p->call.timeouts, CMSG_DATA(cmsg), len);
 574                         p->call.nr_timeouts = len / 4;
 575                         if (p->call.timeouts.hard > INT_MAX / HZ)
 576                                 return -ERANGE;
 577                         if (p->call.nr_timeouts >= 2 && p->call.timeouts.idle > 60 * 60 * 1000)
 578                                 return -ERANGE;
 579                         if (p->call.nr_timeouts >= 3 && p->call.timeouts.normal > 60 * 60 * 1000)
 580                                 return -ERANGE;
 581                         break;
 582
 583                 default:
 584                         return -EINVAL;
 585                 }
 586         }
 587
 588         if (!got_user_ID)
 589                 return -EINVAL;
 590         if (p->call.tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 591                 return -EINVAL;
 592         _leave(" = 0");
 593         return 0;
 594 }
 595
 596 /*
 597  * Create a new client call for sendmsg().
 598  * - Called with the socket lock held, which it must release.
 599  * - If it returns a call, the call's lock will need releasing by the caller.
 600  */
 601 static struct rxrpc_call *
 602 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 603                                   struct rxrpc_send_params *p)
 604         __releases(&rx->sk.sk_lock.slock)
 605         __acquires(&call->user_mutex)
 606 {
 607         struct rxrpc_conn_parameters cp;
 608         struct rxrpc_call *call;
 609         struct key *key;
 610
 611         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 612
 613         _enter("");
 614
 615         if (!msg->msg_name) {
 616                 release_sock(&rx->sk);
 617                 return ERR_PTR(-EDESTADDRREQ);
 618         }
 619
 620         key = rx->key;
 621         if (key && !rx->key->payload.data[0])
 622                 key = NULL;
 623
 624         memset(&cp, 0, sizeof(cp));
 625         cp.local                = rx->local;
 626         cp.key                  = rx->key;
 627         cp.security_level       = rx->min_sec_level;
 628         cp.exclusive            = rx->exclusive | p->exclusive;
 629         cp.upgrade              = p->upgrade;
 630         cp.service_id           = srx->srx_service;
 631         call = rxrpc_new_client_call(rx, &cp, srx, &p->call, GFP_KERNEL,
 632                                      atomic_inc_return(&rxrpc_debug_id));
 633         /* The socket is now unlocked */
 634
 635         rxrpc_put_peer(cp.peer);
 636         _leave(" = %p\n", call);
 637         return call;
 638 }
 639
 640 /*
 641  * send a message forming part of a client call through an RxRPC socket
 642  * - caller holds the socket locked
 643  * - the socket may be either a client socket or a server socket
 644  */
 645 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 646         __releases(&rx->sk.sk_lock.slock)
 647         __releases(&call->user_mutex)
 648 {
 649         enum rxrpc_call_state state;
 650         struct rxrpc_call *call;
 651         unsigned long now, j;
 652         bool dropped_lock = false;
 653         int ret;
 654
 655         struct rxrpc_send_params p = {
 656                 .call.tx_total_len      = -1,
 657                 .call.user_call_ID      = 0,
 658                 .call.nr_timeouts       = 0,
 659                 .call.interruptibility  = RXRPC_INTERRUPTIBLE,
 660                 .abort_code             = 0,
 661                 .command                = RXRPC_CMD_SEND_DATA,
 662                 .exclusive              = false,
 663                 .upgrade                = false,
 664         };
 665
 666         _enter("");
 667
 668         ret = rxrpc_sendmsg_cmsg(msg, &p);
 669         if (ret < 0)
 670                 goto error_release_sock;
 671
 672         if (p.command == RXRPC_CMD_CHARGE_ACCEPT) {
 673                 ret = -EINVAL;
 674                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 675                         goto error_release_sock;
 676                 ret = rxrpc_user_charge_accept(rx, p.call.user_call_ID);
 677                 goto error_release_sock;
 678         }
 679
 680         call = rxrpc_find_call_by_user_ID(rx, p.call.user_call_ID);
 681         if (!call) {
 682                 ret = -EBADSLT;
 683                 if (p.command != RXRPC_CMD_SEND_DATA)
 684                         goto error_release_sock;
 685                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 686                 /* The socket is now unlocked... */
 687                 if (IS_ERR(call))
 688                         return PTR_ERR(call);
 689                 /* ... and we have the call lock. */
 690                 ret = 0;
 691                 if (READ_ONCE(call->state) == RXRPC_CALL_COMPLETE)
 692                         goto out_put_unlock;
 693         } else {
 694                 switch (READ_ONCE(call->state)) {
 695                 case RXRPC_CALL_UNINITIALISED:
 696                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 697                 case RXRPC_CALL_SERVER_PREALLOC:
 698                 case RXRPC_CALL_SERVER_SECURING:
 699                         rxrpc_put_call(call, rxrpc_call_put);
 700                         ret = -EBUSY;
 701                         goto error_release_sock;
 702                 default:
 703                         break;
 704                 }
 705
 706                 ret = mutex_lock_interruptible(&call->user_mutex);
 707                 release_sock(&rx->sk);
 708                 if (ret < 0) {
 709                         ret = -ERESTARTSYS;
 710                         goto error_put;
 711                 }
 712
 713                 if (p.call.tx_total_len != -1) {
 714                         ret = -EINVAL;
 715                         if (call->tx_total_len != -1 ||
 716                             call->tx_pending ||
 717                             call->tx_top != 0)
 718                                 goto error_put;
 719                         call->tx_total_len = p.call.tx_total_len;
 720                 }
 721         }
 722
 723         switch (p.call.nr_timeouts) {
 724         case 3:
 725                 j = msecs_to_jiffies(p.call.timeouts.normal);
 726                 if (p.call.timeouts.normal > 0 && j == 0)
 727                         j = 1;
 728                 WRITE_ONCE(call->next_rx_timo, j);
 729                 fallthrough;
 730         case 2:
 731                 j = msecs_to_jiffies(p.call.timeouts.idle);
 732                 if (p.call.timeouts.idle > 0 && j == 0)
 733                         j = 1;
 734                 WRITE_ONCE(call->next_req_timo, j);
 735                 fallthrough;
 736         case 1:
 737                 if (p.call.timeouts.hard > 0) {
 738                         j = msecs_to_jiffies(p.call.timeouts.hard);
 739                         now = jiffies;
 740                         j += now;
 741                         WRITE_ONCE(call->expect_term_by, j);
 742                         rxrpc_reduce_call_timer(call, j, now,
 743                                                 rxrpc_timer_set_for_hard);
 744                 }
 745                 break;
 746         }
 747
 748         state = READ_ONCE(call->state);
 749         _debug("CALL %d USR %lx ST %d on CONN %p",
 750                call->debug_id, call->user_call_ID, state, call->conn);
 751
 752         if (state >= RXRPC_CALL_COMPLETE) {
 753                 /* it's too late for this call */
 754                 ret = -ESHUTDOWN;
 755         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 756                 ret = 0;
 757                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 758                         ret = rxrpc_send_abort_packet(call);
 759         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 760                 ret = -EINVAL;
 761         } else {
 762                 ret = rxrpc_send_data(rx, call, msg, len, NULL, &dropped_lock);
 763         }
 764
 765 out_put_unlock:
 766         if (!dropped_lock)
 767                 mutex_unlock(&call->user_mutex);
 768 error_put:
 769         rxrpc_put_call(call, rxrpc_call_put);
 770         _leave(" = %d", ret);
 771         return ret;
 772
 773 error_release_sock:
 774         release_sock(&rx->sk);
 775         return ret;
 776 }
 777
 778 /**
 779  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 780  * @sock: The socket the call is on
 781  * @call: The call to send data through
 782  * @msg: The data to send
 783  * @len: The amount of data to send
 784  * @notify_end_tx: Notification that the last packet is queued.
 785  *
 786  * Allow a kernel service to send data on a call.  The call must be in an state
 787  * appropriate to sending data.  No control data should be supplied in @msg,
 788  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 789  * more data to come, otherwise this data will end the transmission phase.
 790  */
 791 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 792                            struct msghdr *msg, size_t len,
 793                            rxrpc_notify_end_tx_t notify_end_tx)
 794 {
 795         bool dropped_lock = false;
 796         int ret;
 797
 798         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 799
 800         ASSERTCMP(msg->msg_name, ==, NULL);
 801         ASSERTCMP(msg->msg_control, ==, NULL);
 802
 803         mutex_lock(&call->user_mutex);
 804
 805         _debug("CALL %d USR %lx ST %d on CONN %p",
 806                call->debug_id, call->user_call_ID, call->state, call->conn);
 807
 808         switch (READ_ONCE(call->state)) {
 809         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 810         case RXRPC_CALL_SERVER_ACK_REQUEST:
 811         case RXRPC_CALL_SERVER_SEND_REPLY:
 812                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len,
 813                                       notify_end_tx, &dropped_lock);
 814                 break;
 815         case RXRPC_CALL_COMPLETE:
 816                 read_lock_bh(&call->state_lock);
 817                 ret = call->error;
 818                 read_unlock_bh(&call->state_lock);
 819                 break;
 820         default:
 821                 /* Request phase complete for this client call */
 822                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 823                 ret = -EPROTO;
 824                 break;
 825         }
 826
 827         if (!dropped_lock)
 828                 mutex_unlock(&call->user_mutex);
 829         _leave(" = %d", ret);
 830         return ret;
 831 }
 832 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 833
 834 /**
 835  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 836  * @sock: The socket the call is on
 837  * @call: The call to be aborted
 838  * @abort_code: The abort code to stick into the ABORT packet
 839  * @error: Local error value
 840  * @why: 3-char string indicating why.
 841  *
 842  * Allow a kernel service to abort a call, if it's still in an abortable state
 843  * and return true if the call was aborted, false if it was already complete.
 844  */
 845 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 846                              u32 abort_code, int error, const char *why)
 847 {
 848         bool aborted;
 849
 850         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 851
 852         mutex_lock(&call->user_mutex);
 853
 854         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 855         if (aborted)
 856                 rxrpc_send_abort_packet(call);
 857
 858         mutex_unlock(&call->user_mutex);
 859         return aborted;
 860 }
 861 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 862
 863 /**
 864  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 865  * @sock: The socket the call is on
 866  * @call: The call to be informed
 867  * @tx_total_len: The amount of data to be transmitted for this call
 868  *
 869  * Allow a kernel service to set the total transmit length on a call.  This
 870  * allows buffer-to-packet encrypt-and-copy to be performed.
 871  *
 872  * This function is primarily for use for setting the reply length since the
 873  * request length can be set when beginning the call.
 874  */
 875 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 876                                 s64 tx_total_len)
 877 {
 878         WARN_ON(call->tx_total_len != -1);
 879         call->tx_total_len = tx_total_len;
 880 }
 881 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);