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