net/rxrpc/ar-output.c

   1 /* RxRPC packet transmission
   2  *
   3  * Copyright (C) 2007 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 License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/net.h>
  13 #include <linux/gfp.h>
  14 #include <linux/skbuff.h>
  15 #include <linux/circ_buf.h>
  16 #include <linux/export.h>
  17 #include <net/sock.h>
  18 #include <net/af_rxrpc.h>
  19 #include "ar-internal.h"
  20
  21 int rxrpc_resend_timeout = 4;
  22
  23 static int rxrpc_send_data(struct kiocb *iocb,
  24                            struct rxrpc_sock *rx,
  25                            struct rxrpc_call *call,
  26                            struct msghdr *msg, size_t len);
  27
  28 /*
  29  * extract control messages from the sendmsg() control buffer
  30  */
  31 static int rxrpc_sendmsg_cmsg(struct rxrpc_sock *rx, struct msghdr *msg,
  32                               unsigned long *user_call_ID,
  33                               enum rxrpc_command *command,
  34                               u32 *abort_code,
  35                               bool server)
  36 {
  37         struct cmsghdr *cmsg;
  38         int len;
  39
  40         *command = RXRPC_CMD_SEND_DATA;
  41
  42         if (msg->msg_controllen == 0)
  43                 return -EINVAL;
  44
  45         for (cmsg = CMSG_FIRSTHDR(msg); cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
  46                 if (!CMSG_OK(msg, cmsg))
  47                         return -EINVAL;
  48
  49                 len = cmsg->cmsg_len - CMSG_ALIGN(sizeof(struct cmsghdr));
  50                 _debug("CMSG %d, %d, %d",
  51                        cmsg->cmsg_level, cmsg->cmsg_type, len);
  52
  53                 if (cmsg->cmsg_level != SOL_RXRPC)
  54                         continue;
  55
  56                 switch (cmsg->cmsg_type) {
  57                 case RXRPC_USER_CALL_ID:
  58                         if (msg->msg_flags & MSG_CMSG_COMPAT) {
  59                                 if (len != sizeof(u32))
  60                                         return -EINVAL;
  61                                 *user_call_ID = *(u32 *) CMSG_DATA(cmsg);
  62                         } else {
  63                                 if (len != sizeof(unsigned long))
  64                                         return -EINVAL;
  65                                 *user_call_ID = *(unsigned long *)
  66                                         CMSG_DATA(cmsg);
  67                         }
  68                         _debug("User Call ID %lx", *user_call_ID);
  69                         break;
  70
  71                 case RXRPC_ABORT:
  72                         if (*command != RXRPC_CMD_SEND_DATA)
  73                                 return -EINVAL;
  74                         *command = RXRPC_CMD_SEND_ABORT;
  75                         if (len != sizeof(*abort_code))
  76                                 return -EINVAL;
  77                         *abort_code = *(unsigned int *) CMSG_DATA(cmsg);
  78                         _debug("Abort %x", *abort_code);
  79                         if (*abort_code == 0)
  80                                 return -EINVAL;
  81                         break;
  82
  83                 case RXRPC_ACCEPT:
  84                         if (*command != RXRPC_CMD_SEND_DATA)
  85                                 return -EINVAL;
  86                         *command = RXRPC_CMD_ACCEPT;
  87                         if (len != 0)
  88                                 return -EINVAL;
  89                         if (!server)
  90                                 return -EISCONN;
  91                         break;
  92
  93                 default:
  94                         return -EINVAL;
  95                 }
  96         }
  97
  98         _leave(" = 0");
  99         return 0;
 100 }
 101
 102 /*
 103  * abort a call, sending an ABORT packet to the peer
 104  */
 105 static void rxrpc_send_abort(struct rxrpc_call *call, u32 abort_code)
 106 {
 107         write_lock_bh(&call->state_lock);
 108
 109         if (call->state <= RXRPC_CALL_COMPLETE) {
 110                 call->state = RXRPC_CALL_LOCALLY_ABORTED;
 111                 call->abort_code = abort_code;
 112                 set_bit(RXRPC_CALL_ABORT, &call->events);
 113                 del_timer_sync(&call->resend_timer);
 114                 del_timer_sync(&call->ack_timer);
 115                 clear_bit(RXRPC_CALL_RESEND_TIMER, &call->events);
 116                 clear_bit(RXRPC_CALL_ACK, &call->events);
 117                 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
 118                 rxrpc_queue_call(call);
 119         }
 120
 121         write_unlock_bh(&call->state_lock);
 122 }
 123
 124 /*
 125  * send a message forming part of a client call through an RxRPC socket
 126  * - caller holds the socket locked
 127  * - the socket may be either a client socket or a server socket
 128  */
 129 int rxrpc_client_sendmsg(struct kiocb *iocb, struct rxrpc_sock *rx,
 130                          struct rxrpc_transport *trans, struct msghdr *msg,
 131                          size_t len)
 132 {
 133         struct rxrpc_conn_bundle *bundle;
 134         enum rxrpc_command cmd;
 135         struct rxrpc_call *call;
 136         unsigned long user_call_ID = 0;
 137         struct key *key;
 138         __be16 service_id;
 139         u32 abort_code = 0;
 140         int ret;
 141
 142         _enter("");
 143
 144         ASSERT(trans != NULL);
 145
 146         ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
 147                                  false);
 148         if (ret < 0)
 149                 return ret;
 150
 151         bundle = NULL;
 152         if (trans) {
 153                 service_id = rx->service_id;
 154                 if (msg->msg_name) {
 155                         struct sockaddr_rxrpc *srx =
 156                                 (struct sockaddr_rxrpc *) msg->msg_name;
 157                         service_id = htons(srx->srx_service);
 158                 }
 159                 key = rx->key;
 160                 if (key && !rx->key->payload.data)
 161                         key = NULL;
 162                 bundle = rxrpc_get_bundle(rx, trans, key, service_id,
 163                                           GFP_KERNEL);
 164                 if (IS_ERR(bundle))
 165                         return PTR_ERR(bundle);
 166         }
 167
 168         call = rxrpc_get_client_call(rx, trans, bundle, user_call_ID,
 169                                      abort_code == 0, GFP_KERNEL);
 170         if (trans)
 171                 rxrpc_put_bundle(trans, bundle);
 172         if (IS_ERR(call)) {
 173                 _leave(" = %ld", PTR_ERR(call));
 174                 return PTR_ERR(call);
 175         }
 176
 177         _debug("CALL %d USR %lx ST %d on CONN %p",
 178                call->debug_id, call->user_call_ID, call->state, call->conn);
 179
 180         if (call->state >= RXRPC_CALL_COMPLETE) {
 181                 /* it's too late for this call */
 182                 ret = -ESHUTDOWN;
 183         } else if (cmd == RXRPC_CMD_SEND_ABORT) {
 184                 rxrpc_send_abort(call, abort_code);
 185         } else if (cmd != RXRPC_CMD_SEND_DATA) {
 186                 ret = -EINVAL;
 187         } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST) {
 188                 /* request phase complete for this client call */
 189                 ret = -EPROTO;
 190         } else {
 191                 ret = rxrpc_send_data(iocb, rx, call, msg, len);
 192         }
 193
 194         rxrpc_put_call(call);
 195         _leave(" = %d", ret);
 196         return ret;
 197 }
 198
 199 /**
 200  * rxrpc_kernel_send_data - Allow a kernel service to send data on a call
 201  * @call: The call to send data through
 202  * @msg: The data to send
 203  * @len: The amount of data to send
 204  *
 205  * Allow a kernel service to send data on a call.  The call must be in an state
 206  * appropriate to sending data.  No control data should be supplied in @msg,
 207  * nor should an address be supplied.  MSG_MORE should be flagged if there's
 208  * more data to come, otherwise this data will end the transmission phase.
 209  */
 210 int rxrpc_kernel_send_data(struct rxrpc_call *call, struct msghdr *msg,
 211                            size_t len)
 212 {
 213         int ret;
 214
 215         _enter("{%d,%s},", call->debug_id, rxrpc_call_states[call->state]);
 216
 217         ASSERTCMP(msg->msg_name, ==, NULL);
 218         ASSERTCMP(msg->msg_control, ==, NULL);
 219
 220         lock_sock(&call->socket->sk);
 221
 222         _debug("CALL %d USR %lx ST %d on CONN %p",
 223                call->debug_id, call->user_call_ID, call->state, call->conn);
 224
 225         if (call->state >= RXRPC_CALL_COMPLETE) {
 226                 ret = -ESHUTDOWN; /* it's too late for this call */
 227         } else if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 228                    call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 229                    call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
 230                 ret = -EPROTO; /* request phase complete for this client call */
 231         } else {
 232                 mm_segment_t oldfs = get_fs();
 233                 set_fs(KERNEL_DS);
 234                 ret = rxrpc_send_data(NULL, call->socket, call, msg, len);
 235                 set_fs(oldfs);
 236         }
 237
 238         release_sock(&call->socket->sk);
 239         _leave(" = %d", ret);
 240         return ret;
 241 }
 242
 243 EXPORT_SYMBOL(rxrpc_kernel_send_data);
 244
 245 /*
 246  * rxrpc_kernel_abort_call - Allow a kernel service to abort a call
 247  * @call: The call to be aborted
 248  * @abort_code: The abort code to stick into the ABORT packet
 249  *
 250  * Allow a kernel service to abort a call, if it's still in an abortable state.
 251  */
 252 void rxrpc_kernel_abort_call(struct rxrpc_call *call, u32 abort_code)
 253 {
 254         _enter("{%d},%d", call->debug_id, abort_code);
 255
 256         lock_sock(&call->socket->sk);
 257
 258         _debug("CALL %d USR %lx ST %d on CONN %p",
 259                call->debug_id, call->user_call_ID, call->state, call->conn);
 260
 261         if (call->state < RXRPC_CALL_COMPLETE)
 262                 rxrpc_send_abort(call, abort_code);
 263
 264         release_sock(&call->socket->sk);
 265         _leave("");
 266 }
 267
 268 EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 269
 270 /*
 271  * send a message through a server socket
 272  * - caller holds the socket locked
 273  */
 274 int rxrpc_server_sendmsg(struct kiocb *iocb, struct rxrpc_sock *rx,
 275                          struct msghdr *msg, size_t len)
 276 {
 277         enum rxrpc_command cmd;
 278         struct rxrpc_call *call;
 279         unsigned long user_call_ID = 0;
 280         u32 abort_code = 0;
 281         int ret;
 282
 283         _enter("");
 284
 285         ret = rxrpc_sendmsg_cmsg(rx, msg, &user_call_ID, &cmd, &abort_code,
 286                                  true);
 287         if (ret < 0)
 288                 return ret;
 289
 290         if (cmd == RXRPC_CMD_ACCEPT) {
 291                 call = rxrpc_accept_call(rx, user_call_ID);
 292                 if (IS_ERR(call))
 293                         return PTR_ERR(call);
 294                 rxrpc_put_call(call);
 295                 return 0;
 296         }
 297
 298         call = rxrpc_find_server_call(rx, user_call_ID);
 299         if (!call)
 300                 return -EBADSLT;
 301         if (call->state >= RXRPC_CALL_COMPLETE) {
 302                 ret = -ESHUTDOWN;
 303                 goto out;
 304         }
 305
 306         switch (cmd) {
 307         case RXRPC_CMD_SEND_DATA:
 308                 if (call->state != RXRPC_CALL_CLIENT_SEND_REQUEST &&
 309                     call->state != RXRPC_CALL_SERVER_ACK_REQUEST &&
 310                     call->state != RXRPC_CALL_SERVER_SEND_REPLY) {
 311                         /* Tx phase not yet begun for this call */
 312                         ret = -EPROTO;
 313                         break;
 314                 }
 315
 316                 ret = rxrpc_send_data(iocb, rx, call, msg, len);
 317                 break;
 318
 319         case RXRPC_CMD_SEND_ABORT:
 320                 rxrpc_send_abort(call, abort_code);
 321                 break;
 322         default:
 323                 BUG();
 324         }
 325
 326         out:
 327         rxrpc_put_call(call);
 328         _leave(" = %d", ret);
 329         return ret;
 330 }
 331
 332 /*
 333  * send a packet through the transport endpoint
 334  */
 335 int rxrpc_send_packet(struct rxrpc_transport *trans, struct sk_buff *skb)
 336 {
 337         struct kvec iov[1];
 338         struct msghdr msg;
 339         int ret, opt;
 340
 341         _enter(",{%d}", skb->len);
 342
 343         iov[0].iov_base = skb->head;
 344         iov[0].iov_len = skb->len;
 345
 346         msg.msg_name = &trans->peer->srx.transport.sin;
 347         msg.msg_namelen = sizeof(trans->peer->srx.transport.sin);
 348         msg.msg_control = NULL;
 349         msg.msg_controllen = 0;
 350         msg.msg_flags = 0;
 351
 352         /* send the packet with the don't fragment bit set if we currently
 353          * think it's small enough */
 354         if (skb->len - sizeof(struct rxrpc_header) < trans->peer->maxdata) {
 355                 down_read(&trans->local->defrag_sem);
 356                 /* send the packet by UDP
 357                  * - returns -EMSGSIZE if UDP would have to fragment the packet
 358                  *   to go out of the interface
 359                  *   - in which case, we'll have processed the ICMP error
 360                  *     message and update the peer record
 361                  */
 362                 ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
 363                                      iov[0].iov_len);
 364
 365                 up_read(&trans->local->defrag_sem);
 366                 if (ret == -EMSGSIZE)
 367                         goto send_fragmentable;
 368
 369                 _leave(" = %d [%u]", ret, trans->peer->maxdata);
 370                 return ret;
 371         }
 372
 373 send_fragmentable:
 374         /* attempt to send this message with fragmentation enabled */
 375         _debug("send fragment");
 376
 377         down_write(&trans->local->defrag_sem);
 378         opt = IP_PMTUDISC_DONT;
 379         ret = kernel_setsockopt(trans->local->socket, SOL_IP, IP_MTU_DISCOVER,
 380                                 (char *) &opt, sizeof(opt));
 381         if (ret == 0) {
 382                 ret = kernel_sendmsg(trans->local->socket, &msg, iov, 1,
 383                                      iov[0].iov_len);
 384
 385                 opt = IP_PMTUDISC_DO;
 386                 kernel_setsockopt(trans->local->socket, SOL_IP,
 387                                   IP_MTU_DISCOVER, (char *) &opt, sizeof(opt));
 388         }
 389
 390         up_write(&trans->local->defrag_sem);
 391         _leave(" = %d [frag %u]", ret, trans->peer->maxdata);
 392         return ret;
 393 }
 394
 395 /*
 396  * wait for space to appear in the transmit/ACK window
 397  * - caller holds the socket locked
 398  */
 399 static int rxrpc_wait_for_tx_window(struct rxrpc_sock *rx,
 400                                     struct rxrpc_call *call,
 401                                     long *timeo)
 402 {
 403         DECLARE_WAITQUEUE(myself, current);
 404         int ret;
 405
 406         _enter(",{%d},%ld",
 407                CIRC_SPACE(call->acks_head, call->acks_tail, call->acks_winsz),
 408                *timeo);
 409
 410         add_wait_queue(&call->tx_waitq, &myself);
 411
 412         for (;;) {
 413                 set_current_state(TASK_INTERRUPTIBLE);
 414                 ret = 0;
 415                 if (CIRC_SPACE(call->acks_head, call->acks_tail,
 416                                call->acks_winsz) > 0)
 417                         break;
 418                 if (signal_pending(current)) {
 419                         ret = sock_intr_errno(*timeo);
 420                         break;
 421                 }
 422
 423                 release_sock(&rx->sk);
 424                 *timeo = schedule_timeout(*timeo);
 425                 lock_sock(&rx->sk);
 426         }
 427
 428         remove_wait_queue(&call->tx_waitq, &myself);
 429         set_current_state(TASK_RUNNING);
 430         _leave(" = %d", ret);
 431         return ret;
 432 }
 433
 434 /*
 435  * attempt to schedule an instant Tx resend
 436  */
 437 static inline void rxrpc_instant_resend(struct rxrpc_call *call)
 438 {
 439         read_lock_bh(&call->state_lock);
 440         if (try_to_del_timer_sync(&call->resend_timer) >= 0) {
 441                 clear_bit(RXRPC_CALL_RUN_RTIMER, &call->flags);
 442                 if (call->state < RXRPC_CALL_COMPLETE &&
 443                     !test_and_set_bit(RXRPC_CALL_RESEND_TIMER, &call->events))
 444                         rxrpc_queue_call(call);
 445         }
 446         read_unlock_bh(&call->state_lock);
 447 }
 448
 449 /*
 450  * queue a packet for transmission, set the resend timer and attempt
 451  * to send the packet immediately
 452  */
 453 static void rxrpc_queue_packet(struct rxrpc_call *call, struct sk_buff *skb,
 454                                bool last)
 455 {
 456         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 457         int ret;
 458
 459         _net("queue skb %p [%d]", skb, call->acks_head);
 460
 461         ASSERT(call->acks_window != NULL);
 462         call->acks_window[call->acks_head] = (unsigned long) skb;
 463         smp_wmb();
 464         call->acks_head = (call->acks_head + 1) & (call->acks_winsz - 1);
 465
 466         if (last || call->state == RXRPC_CALL_SERVER_ACK_REQUEST) {
 467                 _debug("________awaiting reply/ACK__________");
 468                 write_lock_bh(&call->state_lock);
 469                 switch (call->state) {
 470                 case RXRPC_CALL_CLIENT_SEND_REQUEST:
 471                         call->state = RXRPC_CALL_CLIENT_AWAIT_REPLY;
 472                         break;
 473                 case RXRPC_CALL_SERVER_ACK_REQUEST:
 474                         call->state = RXRPC_CALL_SERVER_SEND_REPLY;
 475                         if (!last)
 476                                 break;
 477                 case RXRPC_CALL_SERVER_SEND_REPLY:
 478                         call->state = RXRPC_CALL_SERVER_AWAIT_ACK;
 479                         break;
 480                 default:
 481                         break;
 482                 }
 483                 write_unlock_bh(&call->state_lock);
 484         }
 485
 486         _proto("Tx DATA %%%u { #%u }",
 487                ntohl(sp->hdr.serial), ntohl(sp->hdr.seq));
 488
 489         sp->need_resend = 0;
 490         sp->resend_at = jiffies + rxrpc_resend_timeout * HZ;
 491         if (!test_and_set_bit(RXRPC_CALL_RUN_RTIMER, &call->flags)) {
 492                 _debug("run timer");
 493                 call->resend_timer.expires = sp->resend_at;
 494                 add_timer(&call->resend_timer);
 495         }
 496
 497         /* attempt to cancel the rx-ACK timer, deferring reply transmission if
 498          * we're ACK'ing the request phase of an incoming call */
 499         ret = -EAGAIN;
 500         if (try_to_del_timer_sync(&call->ack_timer) >= 0) {
 501                 /* the packet may be freed by rxrpc_process_call() before this
 502                  * returns */
 503                 ret = rxrpc_send_packet(call->conn->trans, skb);
 504                 _net("sent skb %p", skb);
 505         } else {
 506                 _debug("failed to delete ACK timer");
 507         }
 508
 509         if (ret < 0) {
 510                 _debug("need instant resend %d", ret);
 511                 sp->need_resend = 1;
 512                 rxrpc_instant_resend(call);
 513         }
 514
 515         _leave("");
 516 }
 517
 518 /*
 519  * send data through a socket
 520  * - must be called in process context
 521  * - caller holds the socket locked
 522  */
 523 static int rxrpc_send_data(struct kiocb *iocb,
 524                            struct rxrpc_sock *rx,
 525                            struct rxrpc_call *call,
 526                            struct msghdr *msg, size_t len)
 527 {
 528         struct rxrpc_skb_priv *sp;
 529         unsigned char __user *from;
 530         struct sk_buff *skb;
 531         struct iovec *iov;
 532         struct sock *sk = &rx->sk;
 533         long timeo;
 534         bool more;
 535         int ret, ioc, segment, copied;
 536
 537         _enter(",,,{%zu},%zu", msg->msg_iovlen, len);
 538
 539         timeo = sock_sndtimeo(sk, msg->msg_flags & MSG_DONTWAIT);
 540
 541         /* this should be in poll */
 542         clear_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
 543
 544         if (sk->sk_err || (sk->sk_shutdown & SEND_SHUTDOWN))
 545                 return -EPIPE;
 546
 547         iov = msg->msg_iov;
 548         ioc = msg->msg_iovlen - 1;
 549         from = iov->iov_base;
 550         segment = iov->iov_len;
 551         iov++;
 552         more = msg->msg_flags & MSG_MORE;
 553
 554         skb = call->tx_pending;
 555         call->tx_pending = NULL;
 556
 557         copied = 0;
 558         do {
 559                 int copy;
 560
 561                 if (segment > len)
 562                         segment = len;
 563
 564                 _debug("SEGMENT %d @%p", segment, from);
 565
 566                 if (!skb) {
 567                         size_t size, chunk, max, space;
 568
 569                         _debug("alloc");
 570
 571                         if (CIRC_SPACE(call->acks_head, call->acks_tail,
 572                                        call->acks_winsz) <= 0) {
 573                                 ret = -EAGAIN;
 574                                 if (msg->msg_flags & MSG_DONTWAIT)
 575                                         goto maybe_error;
 576                                 ret = rxrpc_wait_for_tx_window(rx, call,
 577                                                                &timeo);
 578                                 if (ret < 0)
 579                                         goto maybe_error;
 580                         }
 581
 582                         max = call->conn->trans->peer->maxdata;
 583                         max -= call->conn->security_size;
 584                         max &= ~(call->conn->size_align - 1UL);
 585
 586                         chunk = max;
 587                         if (chunk > len && !more)
 588                                 chunk = len;
 589
 590                         space = chunk + call->conn->size_align;
 591                         space &= ~(call->conn->size_align - 1UL);
 592
 593                         size = space + call->conn->header_size;
 594
 595                         _debug("SIZE: %zu/%zu/%zu", chunk, space, size);
 596
 597                         /* create a buffer that we can retain until it's ACK'd */
 598                         skb = sock_alloc_send_skb(
 599                                 sk, size, msg->msg_flags & MSG_DONTWAIT, &ret);
 600                         if (!skb)
 601                                 goto maybe_error;
 602
 603                         rxrpc_new_skb(skb);
 604
 605                         _debug("ALLOC SEND %p", skb);
 606
 607                         ASSERTCMP(skb->mark, ==, 0);
 608
 609                         _debug("HS: %u", call->conn->header_size);
 610                         skb_reserve(skb, call->conn->header_size);
 611                         skb->len += call->conn->header_size;
 612
 613                         sp = rxrpc_skb(skb);
 614                         sp->remain = chunk;
 615                         if (sp->remain > skb_tailroom(skb))
 616                                 sp->remain = skb_tailroom(skb);
 617
 618                         _net("skb: hr %d, tr %d, hl %d, rm %d",
 619                                skb_headroom(skb),
 620                                skb_tailroom(skb),
 621                                skb_headlen(skb),
 622                                sp->remain);
 623
 624                         skb->ip_summed = CHECKSUM_UNNECESSARY;
 625                 }
 626
 627                 _debug("append");
 628                 sp = rxrpc_skb(skb);
 629
 630                 /* append next segment of data to the current buffer */
 631                 copy = skb_tailroom(skb);
 632                 ASSERTCMP(copy, >, 0);
 633                 if (copy > segment)
 634                         copy = segment;
 635                 if (copy > sp->remain)
 636                         copy = sp->remain;
 637
 638                 _debug("add");
 639                 ret = skb_add_data(skb, from, copy);
 640                 _debug("added");
 641                 if (ret < 0)
 642                         goto efault;
 643                 sp->remain -= copy;
 644                 skb->mark += copy;
 645                 copied += copy;
 646
 647                 len -= copy;
 648                 segment -= copy;
 649                 from += copy;
 650                 while (segment == 0 && ioc > 0) {
 651                         from = iov->iov_base;
 652                         segment = iov->iov_len;
 653                         iov++;
 654                         ioc--;
 655                 }
 656                 if (len == 0) {
 657                         segment = 0;
 658                         ioc = 0;
 659                 }
 660
 661                 /* check for the far side aborting the call or a network error
 662                  * occurring */
 663                 if (call->state > RXRPC_CALL_COMPLETE)
 664                         goto call_aborted;
 665
 666                 /* add the packet to the send queue if it's now full */
 667                 if (sp->remain <= 0 || (segment == 0 && !more)) {
 668                         struct rxrpc_connection *conn = call->conn;
 669                         size_t pad;
 670
 671                         /* pad out if we're using security */
 672                         if (conn->security) {
 673                                 pad = conn->security_size + skb->mark;
 674                                 pad = conn->size_align - pad;
 675                                 pad &= conn->size_align - 1;
 676                                 _debug("pad %zu", pad);
 677                                 if (pad)
 678                                         memset(skb_put(skb, pad), 0, pad);
 679                         }
 680
 681                         sp->hdr.epoch = conn->epoch;
 682                         sp->hdr.cid = call->cid;
 683                         sp->hdr.callNumber = call->call_id;
 684                         sp->hdr.seq =
 685                                 htonl(atomic_inc_return(&call->sequence));
 686                         sp->hdr.serial =
 687                                 htonl(atomic_inc_return(&conn->serial));
 688                         sp->hdr.type = RXRPC_PACKET_TYPE_DATA;
 689                         sp->hdr.userStatus = 0;
 690                         sp->hdr.securityIndex = conn->security_ix;
 691                         sp->hdr._rsvd = 0;
 692                         sp->hdr.serviceId = conn->service_id;
 693
 694                         sp->hdr.flags = conn->out_clientflag;
 695                         if (len == 0 && !more)
 696                                 sp->hdr.flags |= RXRPC_LAST_PACKET;
 697                         else if (CIRC_SPACE(call->acks_head, call->acks_tail,
 698                                             call->acks_winsz) > 1)
 699                                 sp->hdr.flags |= RXRPC_MORE_PACKETS;
 700
 701                         ret = rxrpc_secure_packet(
 702                                 call, skb, skb->mark,
 703                                 skb->head + sizeof(struct rxrpc_header));
 704                         if (ret < 0)
 705                                 goto out;
 706
 707                         memcpy(skb->head, &sp->hdr,
 708                                sizeof(struct rxrpc_header));
 709                         rxrpc_queue_packet(call, skb, segment == 0 && !more);
 710                         skb = NULL;
 711                 }
 712
 713         } while (segment > 0);
 714
 715 success:
 716         ret = copied;
 717 out:
 718         call->tx_pending = skb;
 719         _leave(" = %d", ret);
 720         return ret;
 721
 722 call_aborted:
 723         rxrpc_free_skb(skb);
 724         if (call->state == RXRPC_CALL_NETWORK_ERROR)
 725                 ret = call->conn->trans->peer->net_error;
 726         else
 727                 ret = -ECONNABORTED;
 728         _leave(" = %d", ret);
 729         return ret;
 730
 731 maybe_error:
 732         if (copied)
 733                 goto success;
 734         goto out;
 735
 736 efault:
 737         ret = -EFAULT;
 738         goto out;
 739 }