linux/net/rxrpc/ar-output.c
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   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
  21int rxrpc_resend_timeout = 4;
  22
  23static 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 */
  31static 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 */
 105static 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 */
 129int 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 */
 210int 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
 243EXPORT_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 */
 252void 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
 268EXPORT_SYMBOL(rxrpc_kernel_abort_call);
 269
 270/*
 271 * send a message through a server socket
 272 * - caller holds the socket locked
 273 */
 274int 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 */
 335int 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
 373send_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 */
 399static 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 */
 437static 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 */
 453static 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 = false;
 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 = true;
 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 */
 523static 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
 715success:
 716        ret = copied;
 717out:
 718        call->tx_pending = skb;
 719        _leave(" = %d", ret);
 720        return ret;
 721
 722call_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
 731maybe_error:
 732        if (copied)
 733                goto success;
 734        goto out;
 735
 736efault:
 737        ret = -EFAULT;
 738        goto out;
 739}
 740
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