net/rxrpc/sendmsg.c

   1 /* AF_RXRPC sendmsg() implementation.
   2  *
   3  * Copyright (C) 2007, 2016 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public Licence
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the Licence, or (at your option) any later version.
  10  */
  11
  12 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  13
  14 #include <linux/net.h>
  15 #include <linux/gfp.h>
  16 #include <linux/skbuff.h>
  17 #include <linux/export.h>
  18 #include <linux/sched/signal.h>
  19
  20 #include <net/sock.h>
  21 #include <net/af_rxrpc.h>
  22 #include "ar-internal.h"
  23
  24 enum rxrpc_command {
  25         RXRPC_CMD_SEND_DATA,            /* send data message */
  26         RXRPC_CMD_SEND_ABORT,           /* request abort generation */
  27         RXRPC_CMD_ACCEPT,               /* [server] accept incoming call */
  28         RXRPC_CMD_REJECT_BUSY,          /* [server] reject a call as busy */
  29 };
  30
  31 struct rxrpc_send_params {
  32         s64                     tx_total_len;   /* Total Tx data length (if send data) */
  33         unsigned long           user_call_ID;   /* User's call ID */
  34         u32                     abort_code;     /* Abort code to Tx (if abort) */
  35         enum rxrpc_command      command : 8;    /* The command to implement */
  36         bool                    exclusive;      /* Shared or exclusive call */
  37         bool                    upgrade;        /* If the connection is upgradeable */
  38 };
  39
  40 /*
  41  * wait for space to appear in the transmit/ACK window
  42  * - caller holds the socket locked
  43  */
  44 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
  45                                     struct rxrpc_call *call,
  46                                     long *timeo)
  47 {
  48         DECLARE_WAITQUEUE(myself, current);
  49         int ret;
  50
  51         _enter(",{%u,%u,%u}",
  52                call->tx_hard_ack, call->tx_top, call->tx_winsize);
  53
  54         add_wait_queue(&call->waitq, &myself);
  55
  56         for (;;) {
  57                 set_current_state(TASK_INTERRUPTIBLE);
  58                 ret = 0;
  59                 if (call->tx_top - call->tx_hard_ack <
  60                     min_t(unsigned int, call->tx_winsize,
  61                           call->cong_cwnd + call->cong_extra))
  62                         break;
  63                 if (call->state >= RXRPC_CALL_COMPLETE) {
  64                         ret = -call->error;
  65                         break;
  66                 }
  67                 if (signal_pending(current)) {
  68                         ret = sock_intr_errno(*timeo);
  69                         break;
  70                 }
  71
  72                 trace_rxrpc_transmit(call, rxrpc_transmit_wait);
  73                 mutex_unlock(&call->user_mutex);
  74                 *timeo = schedule_timeout(*timeo);
  75                 if (mutex_lock_interruptible(&call->user_mutex) < 0) {
  76                         ret = sock_intr_errno(*timeo);
  77                         break;
  78                 }
  79         }
  80
  81         remove_wait_queue(&call->waitq, &myself);
  82         set_current_state(TASK_RUNNING);
  83         _leave(" = %d", ret);
  84         return ret;
  85 }
  86
  87 /*
  88  * Schedule an instant Tx resend.
  89  */
  90 static inline void rxrpc_instant_resend(struct rxrpc_call *call, int ix)
  91 {
  92         spin_lock_bh(&call->lock);
  93
  94         if (call->state < RXRPC_CALL_COMPLETE) {
  95                 call->rxtx_annotations[ix] = RXRPC_TX_ANNO_RETRANS;
  96                 if (!test_and_set_bit(RXRPC_CALL_EV_RESEND, &call->events))
  97                         rxrpc_queue_call(call);
  98         }
  99
 100         spin_unlock_bh(&call->lock);
 101 }
 102
 103 /*
 104  * Queue a DATA packet for transmission, set the resend timeout and send the
 105  * packet immediately
 106  */
 107 static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
 108                                bool last)
 109 {
 110         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 111         rxrpc_seq_t seq = sp->hdr.seq;
 112         int ret, ix;
 113         u8 annotation = RXRPC_TX_ANNO_UNACK;
 114
 115         _net("queue skb %p [%d]", skb, seq);
 116
 117         ASSERTCMP(seq, ==, call->tx_top + 1);
 118
 119         if (last)
 120                 annotation |= RXRPC_TX_ANNO_LAST;
 121
 122         /* We have to set the timestamp before queueing as the retransmit
 123          * algorithm can see the packet as soon as we queue it.
 124          */
 125         skb->tstamp = ktime_get_real();
 126
 127         ix = seq & RXRPC_RXTX_BUFF_MASK;
 128         rxrpc_get_skb(skb, rxrpc_skb_tx_got);
 129         call->rxtx_annotations[ix] = annotation;
 130         smp_wmb();
 131         call->rxtx_buffer[ix] = skb;
 132         call->tx_top = seq;
 133         if (last)
 134                 trace_rxrpc_transmit(call, rxrpc_transmit_queue_last);
 135         else
 136                 trace_rxrpc_transmit(call, rxrpc_transmit_queue);
 137
 138         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 139                 _debug("________awaiting reply/ACK__________");
 140                 write_lock_bh(&call->state_lock);
 141                 switch (call->state) {
 142                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 143                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 144                         break;
 145                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 146                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 147                         call->ack_at = call->expire_at;
 148                         if (call->ackr_reason == RXRPC_ACK_DELAY)
 149                                 call->ackr_reason = 0;
 150                         __rxrpc_set_timer(call, rxrpc_timer_init_for_send_reply,
 151                                           ktime_get_real());
 152                         if (!last)
 153                                 break;
 154                 case RXRPC_CALL_SERVER_SEND_REPLY:
 155                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 156                         break;
 157                 default:
 158                         break;
 159                 }
 160                 write_unlock_bh(&call->state_lock);
 161         }
 162
 163         if (seq == 1 && rxrpc_is_client_call(call))
 164                 rxrpc_expose_client_call(call);
 165
 166         ret = rxrpc_send_data_packet(call, skb, false);
 167         if (ret < 0) {
 168                 _debug("need instant resend %d", ret);
 169                 rxrpc_instant_resend(call, ix);
 170         } else {
 171                 ktime_t now = ktime_get_real(), resend_at;
 172
 173                 resend_at = ktime_add_ms(now, rxrpc_resend_timeout);
 174
 175                 if (ktime_before(resend_at, call->resend_at)) {
 176                         call->resend_at = resend_at;
 177                         rxrpc_set_timer(call, rxrpc_timer_set_for_send, now);
 178                 }
 179         }
 180
 181         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 182         _leave("");
 183 }
 184
 185 /*
 186  * send data through a socket
 187  * - must be called in process context
 188  * - The caller holds the call user access mutex, but not the socket lock.
 189  */
 190 static int rxrpc_send_data(struct rxrpc_sock *rx,
 191                            struct rxrpc_call *call,
 192                            struct msghdr *msg, size_t len)
 193 {
 194         struct rxrpc_skb_priv *sp;
 195         struct sk_buff *skb;
 196         struct sock *sk = &rx->sk;
 197         long timeo;
 198         bool more;
 199         int ret, copied;
 200
 201         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 202
 203         /* this should be in poll */
 204         sk_clear_bit(SOCKWQ_ASYNC_NOSPACE, sk);
 205
 206         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 207                 return -EPIPE;
 208
 209         more = msg->msg_flags & MSG_MORE;
 210
 211         if (call->tx_total_len != -1) {
 212                 if (len > call->tx_total_len)
 213                         return -EMSGSIZE;
 214                 if (!more && len != call->tx_total_len)
 215                         return -EMSGSIZE;
 216         }
 217
 218         skb = call->tx_pending;
 219         call->tx_pending = NULL;
 220         rxrpc_see_skb(skb, rxrpc_skb_tx_seen);
 221
 222         copied = 0;
 223         do {
 224                 /* Check to see if there's a ping ACK to reply to. */
 225                 if (call->ackr_reason == RXRPC_ACK_PING_RESPONSE)
 226                         rxrpc_send_ack_packet(call, false);
 227
 228                 if (!skb) {
 229                         size_t size, chunk, max, space;
 230
 231                         _debug("alloc");
 232
 233                         if (call->tx_top - call->tx_hard_ack >=
 234                             min_t(unsigned int, call->tx_winsize,
 235                                   call->cong_cwnd + call->cong_extra)) {
 236                                 ret = -EAGAIN;
 237                                 if (msg->msg_flags & MSG_DONTWAIT)
 238                                         goto maybe_error;
 239                                 ret = rxrpc_wait_for_tx_window(rx, call,
 240                                                                &timeo);
 241                                 if (ret < 0)
 242                                         goto maybe_error;
 243                         }
 244
 245                         max = RXRPC_JUMBO_DATALEN;
 246                         max -= call->conn->security_size;
 247                         max &= ~(call->conn->size_align - 1UL);
 248
 249                         chunk = max;
 250                         if (chunk > msg_data_left(msg) && !more)
 251                                 chunk = msg_data_left(msg);
 252
 253                         space = chunk + call->conn->size_align;
 254                         space &= ~(call->conn->size_align - 1UL);
 255
 256                         size = space + call->conn->security_size;
 257
 258                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 259
 260                         /* create a buffer that we can retain until it's ACK'd */
 261                         skb = sock_alloc_send_skb(
 262                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 263                         if (!skb)
 264                                 goto maybe_error;
 265
 266                         rxrpc_new_skb(skb, rxrpc_skb_tx_new);
 267
 268                         _debug("ALLOC SEND %p", skb);
 269
 270                         ASSERTCMP(skb->mark, ==, 0);
 271
 272                         _debug("HS: %u", call->conn->security_size);
 273                         skb_reserve(skb, call->conn->security_size);
 274                         skb->len += call->conn->security_size;
 275
 276                         sp = rxrpc_skb(skb);
 277                         sp->remain = chunk;
 278                         if (sp->remain > skb_tailroom(skb))
 279                                 sp->remain = skb_tailroom(skb);
 280
 281                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 282                                skb_headroom(skb),
 283                                skb_tailroom(skb),
 284                                skb_headlen(skb),
 285                                sp->remain);
 286
 287                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 288                 }
 289
 290                 _debug("append");
 291                 sp = rxrpc_skb(skb);
 292
 293                 /* append next segment of data to the current buffer */
 294                 if (msg_data_left(msg) > 0) {
 295                         int copy = skb_tailroom(skb);
 296                         ASSERTCMP(copy, >, 0);
 297                         if (copy > msg_data_left(msg))
 298                                 copy = msg_data_left(msg);
 299                         if (copy > sp->remain)
 300                                 copy = sp->remain;
 301
 302                         _debug("add");
 303                         ret = skb_add_data(skb, &msg->msg_iter, copy);
 304                         _debug("added");
 305                         if (ret < 0)
 306                                 goto efault;
 307                         sp->remain -= copy;
 308                         skb->mark += copy;
 309                         copied += copy;
 310                         if (call->tx_total_len != -1)
 311                                 call->tx_total_len -= copy;
 312                 }
 313
 314                 /* check for the far side aborting the call or a network error
 315                  * occurring */
 316                 if (call->state == RXRPC_CALL_COMPLETE)
 317                         goto call_terminated;
 318
 319                 /* add the packet to the send queue if it's now full */
 320                 if (sp->remain <= 0 ||
 321                     (msg_data_left(msg) == 0 && !more)) {
 322                         struct rxrpc_connection *conn = call->conn;
 323                         uint32_t seq;
 324                         size_t pad;
 325
 326                         /* pad out if we're using security */
 327                         if (conn->security_ix) {
 328                                 pad = conn->security_size + skb->mark;
 329                                 pad = conn->size_align - pad;
 330                                 pad &= conn->size_align - 1;
 331                                 _debug("pad %zu", pad);
 332                                 if (pad)
 333                                         skb_put_zero(skb, pad);
 334                         }
 335
 336                         seq = call->tx_top + 1;
 337
 338                         sp->hdr.seq     = seq;
 339                         sp->hdr._rsvd   = 0;
 340                         sp->hdr.flags   = conn->out_clientflag;
 341
 342                         if (msg_data_left(msg) == 0 && !more)
 343                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 344                         else if (call->tx_top - call->tx_hard_ack <
 345                                  call->tx_winsize)
 346                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 347
 348                         ret = conn->security->secure_packet(
 349                                 call, skb, skb->mark, skb->head);
 350                         if (ret < 0)
 351                                 goto out;
 352
 353                         rxrpc_queue_packet(call, skb, !msg_data_left(msg) && !more);
 354                         skb = NULL;
 355                 }
 356         } while (msg_data_left(msg) > 0);
 357
 358 success:
 359         ret = copied;
 360 out:
 361         call->tx_pending = skb;
 362         _leave(" = %d", ret);
 363         return ret;
 364
 365 call_terminated:
 366         rxrpc_free_skb(skb, rxrpc_skb_tx_freed);
 367         _leave(" = %d", -call->error);
 368         return -call->error;
 369
 370 maybe_error:
 371         if (copied)
 372                 goto success;
 373         goto out;
 374
 375 efault:
 376         ret = -EFAULT;
 377         goto out;
 378 }
 379
 380 /*
 381  * extract control messages from the sendmsg() control buffer
 382  */
 383 static int rxrpc_sendmsg_cmsg(struct msghdr *msg, struct rxrpc_send_params *p)
 384 {
 385         struct cmsghdr *cmsg;
 386         bool got_user_ID = false;
 387         int len;
 388
 389         if (msg->msg_controllen == 0)
 390                 return -EINVAL;
 391
 392         for_each_cmsghdr(cmsg, msg) {
 393                 if (!CMSG_OK(msg, cmsg))
 394                         return -EINVAL;
 395
 396                 len = cmsg->cmsg_len - sizeof(struct cmsghdr);
 397                 _debug("CMSG %d, %d, %d",
 398                        cmsg->cmsg_level, cmsg->cmsg_type, len);
 399
 400                 if (cmsg->cmsg_level != SOL_RXRPC)
 401                         continue;
 402
 403                 switch (cmsg->cmsg_type) {
 404                 case RXRPC_USER_CALL_ID:
 405                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
 406                                 if (len != sizeof(u32))
 407                                         return -EINVAL;
 408                                 p->user_call_ID = *(u32 *)CMSG_DATA(cmsg);
 409                         } else {
 410                                 if (len != sizeof(unsigned long))
 411                                         return -EINVAL;
 412                                 p->user_call_ID = *(unsigned long *)
 413                                         CMSG_DATA(cmsg);
 414                         }
 415                         got_user_ID = true;
 416                         break;
 417
 418                 case RXRPC_ABORT:
 419                         if (p->command != RXRPC_CMD_SEND_DATA)
 420                                 return -EINVAL;
 421                         p->command = RXRPC_CMD_SEND_ABORT;
 422                         if (len != sizeof(p->abort_code))
 423                                 return -EINVAL;
 424                         p->abort_code = *(unsigned int *)CMSG_DATA(cmsg);
 425                         if (p->abort_code == 0)
 426                                 return -EINVAL;
 427                         break;
 428
 429                 case RXRPC_ACCEPT:
 430                         if (p->command != RXRPC_CMD_SEND_DATA)
 431                                 return -EINVAL;
 432                         p->command = RXRPC_CMD_ACCEPT;
 433                         if (len != 0)
 434                                 return -EINVAL;
 435                         break;
 436
 437                 case RXRPC_EXCLUSIVE_CALL:
 438                         p->exclusive = true;
 439                         if (len != 0)
 440                                 return -EINVAL;
 441                         break;
 442
 443                 case RXRPC_UPGRADE_SERVICE:
 444                         p->upgrade = true;
 445                         if (len != 0)
 446                                 return -EINVAL;
 447                         break;
 448
 449                 case RXRPC_TX_LENGTH:
 450                         if (p->tx_total_len != -1 || len != sizeof(__s64))
 451                                 return -EINVAL;
 452                         p->tx_total_len = *(__s64 *)CMSG_DATA(cmsg);
 453                         if (p->tx_total_len < 0)
 454                                 return -EINVAL;
 455                         break;
 456
 457                 default:
 458                         return -EINVAL;
 459                 }
 460         }
 461
 462         if (!got_user_ID)
 463                 return -EINVAL;
 464         if (p->tx_total_len != -1 && p->command != RXRPC_CMD_SEND_DATA)
 465                 return -EINVAL;
 466         _leave(" = 0");
 467         return 0;
 468 }
 469
 470 /*
 471  * Create a new client call for sendmsg().
 472  * - Called with the socket lock held, which it must release.
 473  * - If it returns a call, the call's lock will need releasing by the caller.
 474  */
 475 static struct rxrpc_call *
 476 rxrpc_new_client_call_for_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg,
 477                                   struct rxrpc_send_params *p)
 478         __releases(&rx->sk.sk_lock.slock)
 479 {
 480         struct rxrpc_conn_parameters cp;
 481         struct rxrpc_call *call;
 482         struct key *key;
 483
 484         DECLARE_SOCKADDR(struct sockaddr_rxrpc *, srx, msg->msg_name);
 485
 486         _enter("");
 487
 488         if (!msg->msg_name) {
 489                 release_sock(&rx->sk);
 490                 return ERR_PTR(-EDESTADDRREQ);
 491         }
 492
 493         key = rx->key;
 494         if (key && !rx->key->payload.data[0])
 495                 key = NULL;
 496
 497         memset(&cp, 0, sizeof(cp));
 498         cp.local                = rx->local;
 499         cp.key                  = rx->key;
 500         cp.security_level       = rx->min_sec_level;
 501         cp.exclusive            = rx->exclusive | p->exclusive;
 502         cp.upgrade              = p->upgrade;
 503         cp.service_id           = srx->srx_service;
 504         call = rxrpc_new_client_call(rx, &cp, srx, p->user_call_ID,
 505                                      p->tx_total_len, GFP_KERNEL);
 506         /* The socket is now unlocked */
 507
 508         _leave(" = %p\n", call);
 509         return call;
 510 }
 511
 512 /*
 513  * send a message forming part of a client call through an RxRPC socket
 514  * - caller holds the socket locked
 515  * - the socket may be either a client socket or a server socket
 516  */
 517 int rxrpc_do_sendmsg(struct rxrpc_sock *rx, struct msghdr *msg, size_t len)
 518         __releases(&rx->sk.sk_lock.slock)
 519 {
 520         enum rxrpc_call_state state;
 521         struct rxrpc_call *call;
 522         int ret;
 523
 524         struct rxrpc_send_params p = {
 525                 .tx_total_len   = -1,
 526                 .user_call_ID   = 0,
 527                 .abort_code     = 0,
 528                 .command        = RXRPC_CMD_SEND_DATA,
 529                 .exclusive      = false,
 530                 .upgrade        = true,
 531         };
 532
 533         _enter("");
 534
 535         ret = rxrpc_sendmsg_cmsg(msg, &p);
 536         if (ret < 0)
 537                 goto error_release_sock;
 538
 539         if (p.command == RXRPC_CMD_ACCEPT) {
 540                 ret = -EINVAL;
 541                 if (rx->sk.sk_state != RXRPC_SERVER_LISTENING)
 542                         goto error_release_sock;
 543                 call = rxrpc_accept_call(rx, p.user_call_ID, NULL);
 544                 /* The socket is now unlocked. */
 545                 if (IS_ERR(call))
 546                         return PTR_ERR(call);
 547                 rxrpc_put_call(call, rxrpc_call_put);
 548                 return 0;
 549         }
 550
 551         call = rxrpc_find_call_by_user_ID(rx, p.user_call_ID);
 552         if (!call) {
 553                 ret = -EBADSLT;
 554                 if (p.command != RXRPC_CMD_SEND_DATA)
 555                         goto error_release_sock;
 556                 call = rxrpc_new_client_call_for_sendmsg(rx, msg, &p);
 557                 /* The socket is now unlocked... */
 558                 if (IS_ERR(call))
 559                         return PTR_ERR(call);
 560                 /* ... and we have the call lock. */
 561         } else {
 562                 switch (READ_ONCE(call->state)) {
 563                 case RXRPC_CALL_UNINITIALISED:
 564                 case RXRPC_CALL_CLIENT_AWAIT_CONN:
 565                 case RXRPC_CALL_SERVER_PREALLOC:
 566                 case RXRPC_CALL_SERVER_SECURING:
 567                 case RXRPC_CALL_SERVER_ACCEPTING:
 568                         ret = -EBUSY;
 569                         goto error_release_sock;
 570                 default:
 571                         break;
 572                 }
 573
 574                 ret = mutex_lock_interruptible(&call->user_mutex);
 575                 release_sock(&rx->sk);
 576                 if (ret < 0) {
 577                         ret = -ERESTARTSYS;
 578                         goto error_put;
 579                 }
 580
 581                 if (p.tx_total_len != -1) {
 582                         ret = -EINVAL;
 583                         if (call->tx_total_len != -1 ||
 584                             call->tx_pending ||
 585                             call->tx_top != 0)
 586                                 goto error_put;
 587                         call->tx_total_len = p.tx_total_len;
 588                 }
 589         }
 590
 591         state = READ_ONCE(call->state);
 592         _debug("CALL %d USR %lx ST %d on CONN %p",
 593                call->debug_id, call->user_call_ID, state, call->conn);
 594
 595         if (state >= RXRPC_CALL_COMPLETE) {
 596                 /* it's too late for this call */
 597                 ret = -ESHUTDOWN;
 598         } else if (p.command == RXRPC_CMD_SEND_ABORT) {
 599                 ret = 0;
 600                 if (rxrpc_abort_call("CMD", call, 0, p.abort_code, -ECONNABORTED))
 601                         ret = rxrpc_send_abort_packet(call);
 602         } else if (p.command != RXRPC_CMD_SEND_DATA) {
 603                 ret = -EINVAL;
 604         } else if (rxrpc_is_client_call(call) &&
 605                    state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 606                 /* request phase complete for this client call */
 607                 ret = -EPROTO;
 608         } else if (rxrpc_is_service_call(call) &&
 609                    state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 610                    state != RXRPC_CALL_SERVER_SEND_REPLY) {
 611                 /* Reply phase not begun or not complete for service call. */
 612                 ret = -EPROTO;
 613         } else {
 614                 ret = rxrpc_send_data(rx, call, msg, len);
 615         }
 616
 617         mutex_unlock(&call->user_mutex);
 618 error_put:
 619         rxrpc_put_call(call, rxrpc_call_put);
 620         _leave(" = %d", ret);
 621         return ret;
 622
 623 error_release_sock:
 624         release_sock(&rx->sk);
 625         return ret;
 626 }
 627
 628 /**
 629  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 630  * @sock: The socket the call is on
 631  * @call: The call to send data through
 632  * @msg: The data to send
 633  * @len: The amount of data to send
 634  *
 635  * Allow a kernel service to send data on a call.  The call must be in an state
 636  * appropriate to sending data.  No control data should be supplied in @msg,
 637  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 638  * more data to come, otherwise this data will end the transmission phase.
 639  */
 640 int rxrpc_kernel_send_data(struct socket *sock, struct rxrpc_call *call,
 641                            struct msghdr *msg, size_t len)
 642 {
 643         int ret;
 644
 645         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 646
 647         ASSERTCMP(msg->msg_name, ==, NULL);
 648         ASSERTCMP(msg->msg_control, ==, NULL);
 649
 650         mutex_lock(&call->user_mutex);
 651
 652         _debug("CALL %d USR %lx ST %d on CONN %p",
 653                call->debug_id, call->user_call_ID, call->state, call->conn);
 654
 655         switch (READ_ONCE(call->state)) {
 656         case RXRPC_CALL_CLIENT_SEND_REQUEST:
 657         case RXRPC_CALL_SERVER_ACK_REQUEST:
 658         case RXRPC_CALL_SERVER_SEND_REPLY:
 659                 ret = rxrpc_send_data(rxrpc_sk(sock->sk), call, msg, len);
 660                 break;
 661         case RXRPC_CALL_COMPLETE:
 662                 read_lock_bh(&call->state_lock);
 663                 ret = -call->error;
 664                 read_unlock_bh(&call->state_lock);
 665                 break;
 666         default:
 667                 /* Request phase complete for this client call */
 668                 trace_rxrpc_rx_eproto(call, 0, tracepoint_string("late_send"));
 669                 ret = -EPROTO;
 670                 break;
 671         }
 672
 673         mutex_unlock(&call->user_mutex);
 674         _leave(" = %d", ret);
 675         return ret;
 676 }
 677 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 678
 679 /**
 680  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 681  * @sock: The socket the call is on
 682  * @call: The call to be aborted
 683  * @abort_code: The abort code to stick into the ABORT packet
 684  * @error: Local error value
 685  * @why: 3-char string indicating why.
 686  *
 687  * Allow a kernel service to abort a call, if it's still in an abortable state
 688  * and return true if the call was aborted, false if it was already complete.
 689  */
 690 bool rxrpc_kernel_abort_call(struct socket *sock, struct rxrpc_call *call,
 691                              u32 abort_code, int error, const char *why)
 692 {
 693         bool aborted;
 694
 695         _enter("{%d},%d,%d,%s", call->debug_id, abort_code, error, why);
 696
 697         mutex_lock(&call->user_mutex);
 698
 699         aborted = rxrpc_abort_call(why, call, 0, abort_code, error);
 700         if (aborted)
 701                 rxrpc_send_abort_packet(call);
 702
 703         mutex_unlock(&call->user_mutex);
 704         return aborted;
 705 }
 706 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 707
 708 /**
 709  * rxrpc_kernel_set_tx_length - Set the total Tx length on a call
 710  * @sock: The socket the call is on
 711  * @call: The call to be informed
 712  * @tx_total_len: The amount of data to be transmitted for this call
 713  *
 714  * Allow a kernel service to set the total transmit length on a call.  This
 715  * allows buffer-to-packet encrypt-and-copy to be performed.
 716  *
 717  * This function is primarily for use for setting the reply length since the
 718  * request length can be set when beginning the call.
 719  */
 720 void rxrpc_kernel_set_tx_length(struct socket *sock, struct rxrpc_call *call,
 721                                 s64 tx_total_len)
 722 {
 723         WARN_ON(call->tx_total_len != -1);
 724         call->tx_total_len = tx_total_len;
 725 }
 726 EXPORT_SYMBOL(rxrpc_kernel_set_tx_length);