linux/net/tipc/socket.c
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   1/*
   2 * net/tipc/socket.c: TIPC socket API
   3 *
   4 * Copyright (c) 2001-2007, Ericsson AB
   5 * Copyright (c) 2004-2008, Wind River Systems
   6 * All rights reserved.
   7 *
   8 * Redistribution and use in source and binary forms, with or without
   9 * modification, are permitted provided that the following conditions are met:
  10 *
  11 * 1. Redistributions of source code must retain the above copyright
  12 *    notice, this list of conditions and the following disclaimer.
  13 * 2. Redistributions in binary form must reproduce the above copyright
  14 *    notice, this list of conditions and the following disclaimer in the
  15 *    documentation and/or other materials provided with the distribution.
  16 * 3. Neither the names of the copyright holders nor the names of its
  17 *    contributors may be used to endorse or promote products derived from
  18 *    this software without specific prior written permission.
  19 *
  20 * Alternatively, this software may be distributed under the terms of the
  21 * GNU General Public License ("GPL") version 2 as published by the Free
  22 * Software Foundation.
  23 *
  24 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  25 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  28 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  29 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  30 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  31 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  32 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  33 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  34 * POSSIBILITY OF SUCH DAMAGE.
  35 */
  36
  37#include <linux/module.h>
  38#include <linux/types.h>
  39#include <linux/net.h>
  40#include <linux/socket.h>
  41#include <linux/errno.h>
  42#include <linux/mm.h>
  43#include <linux/slab.h>
  44#include <linux/poll.h>
  45#include <linux/fcntl.h>
  46#include <asm/string.h>
  47#include <asm/atomic.h>
  48#include <net/sock.h>
  49
  50#include <linux/tipc.h>
  51#include <linux/tipc_config.h>
  52#include <net/tipc/tipc_msg.h>
  53#include <net/tipc/tipc_port.h>
  54
  55#include "core.h"
  56
  57#define SS_LISTENING    -1      /* socket is listening */
  58#define SS_READY        -2      /* socket is connectionless */
  59
  60#define OVERLOAD_LIMIT_BASE     5000
  61#define CONN_TIMEOUT_DEFAULT    8000    /* default connect timeout = 8s */
  62
  63struct tipc_sock {
  64        struct sock sk;
  65        struct tipc_port *p;
  66        struct tipc_portid peer_name;
  67};
  68
  69#define tipc_sk(sk) ((struct tipc_sock *)(sk))
  70#define tipc_sk_port(sk) ((struct tipc_port *)(tipc_sk(sk)->p))
  71
  72static int backlog_rcv(struct sock *sk, struct sk_buff *skb);
  73static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf);
  74static void wakeupdispatch(struct tipc_port *tport);
  75
  76static const struct proto_ops packet_ops;
  77static const struct proto_ops stream_ops;
  78static const struct proto_ops msg_ops;
  79
  80static struct proto tipc_proto;
  81
  82static int sockets_enabled = 0;
  83
  84static atomic_t tipc_queue_size = ATOMIC_INIT(0);
  85
  86/*
  87 * Revised TIPC socket locking policy:
  88 *
  89 * Most socket operations take the standard socket lock when they start
  90 * and hold it until they finish (or until they need to sleep).  Acquiring
  91 * this lock grants the owner exclusive access to the fields of the socket
  92 * data structures, with the exception of the backlog queue.  A few socket
  93 * operations can be done without taking the socket lock because they only
  94 * read socket information that never changes during the life of the socket.
  95 *
  96 * Socket operations may acquire the lock for the associated TIPC port if they
  97 * need to perform an operation on the port.  If any routine needs to acquire
  98 * both the socket lock and the port lock it must take the socket lock first
  99 * to avoid the risk of deadlock.
 100 *
 101 * The dispatcher handling incoming messages cannot grab the socket lock in
 102 * the standard fashion, since invoked it runs at the BH level and cannot block.
 103 * Instead, it checks to see if the socket lock is currently owned by someone,
 104 * and either handles the message itself or adds it to the socket's backlog
 105 * queue; in the latter case the queued message is processed once the process
 106 * owning the socket lock releases it.
 107 *
 108 * NOTE: Releasing the socket lock while an operation is sleeping overcomes
 109 * the problem of a blocked socket operation preventing any other operations
 110 * from occurring.  However, applications must be careful if they have
 111 * multiple threads trying to send (or receive) on the same socket, as these
 112 * operations might interfere with each other.  For example, doing a connect
 113 * and a receive at the same time might allow the receive to consume the
 114 * ACK message meant for the connect.  While additional work could be done
 115 * to try and overcome this, it doesn't seem to be worthwhile at the present.
 116 *
 117 * NOTE: Releasing the socket lock while an operation is sleeping also ensures
 118 * that another operation that must be performed in a non-blocking manner is
 119 * not delayed for very long because the lock has already been taken.
 120 *
 121 * NOTE: This code assumes that certain fields of a port/socket pair are
 122 * constant over its lifetime; such fields can be examined without taking
 123 * the socket lock and/or port lock, and do not need to be re-read even
 124 * after resuming processing after waiting.  These fields include:
 125 *   - socket type
 126 *   - pointer to socket sk structure (aka tipc_sock structure)
 127 *   - pointer to port structure
 128 *   - port reference
 129 */
 130
 131/**
 132 * advance_rx_queue - discard first buffer in socket receive queue
 133 *
 134 * Caller must hold socket lock
 135 */
 136
 137static void advance_rx_queue(struct sock *sk)
 138{
 139        buf_discard(__skb_dequeue(&sk->sk_receive_queue));
 140        atomic_dec(&tipc_queue_size);
 141}
 142
 143/**
 144 * discard_rx_queue - discard all buffers in socket receive queue
 145 *
 146 * Caller must hold socket lock
 147 */
 148
 149static void discard_rx_queue(struct sock *sk)
 150{
 151        struct sk_buff *buf;
 152
 153        while ((buf = __skb_dequeue(&sk->sk_receive_queue))) {
 154                atomic_dec(&tipc_queue_size);
 155                buf_discard(buf);
 156        }
 157}
 158
 159/**
 160 * reject_rx_queue - reject all buffers in socket receive queue
 161 *
 162 * Caller must hold socket lock
 163 */
 164
 165static void reject_rx_queue(struct sock *sk)
 166{
 167        struct sk_buff *buf;
 168
 169        while ((buf = __skb_dequeue(&sk->sk_receive_queue))) {
 170                tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
 171                atomic_dec(&tipc_queue_size);
 172        }
 173}
 174
 175/**
 176 * tipc_create - create a TIPC socket
 177 * @net: network namespace (must be default network)
 178 * @sock: pre-allocated socket structure
 179 * @protocol: protocol indicator (must be 0)
 180 *
 181 * This routine creates additional data structures used by the TIPC socket,
 182 * initializes them, and links them together.
 183 *
 184 * Returns 0 on success, errno otherwise
 185 */
 186
 187static int tipc_create(struct net *net, struct socket *sock, int protocol)
 188{
 189        const struct proto_ops *ops;
 190        socket_state state;
 191        struct sock *sk;
 192        struct tipc_port *tp_ptr;
 193
 194        /* Validate arguments */
 195
 196        if (net != &init_net)
 197                return -EAFNOSUPPORT;
 198
 199        if (unlikely(protocol != 0))
 200                return -EPROTONOSUPPORT;
 201
 202        switch (sock->type) {
 203        case SOCK_STREAM:
 204                ops = &stream_ops;
 205                state = SS_UNCONNECTED;
 206                break;
 207        case SOCK_SEQPACKET:
 208                ops = &packet_ops;
 209                state = SS_UNCONNECTED;
 210                break;
 211        case SOCK_DGRAM:
 212        case SOCK_RDM:
 213                ops = &msg_ops;
 214                state = SS_READY;
 215                break;
 216        default:
 217                return -EPROTOTYPE;
 218        }
 219
 220        /* Allocate socket's protocol area */
 221
 222        sk = sk_alloc(net, AF_TIPC, GFP_KERNEL, &tipc_proto);
 223        if (sk == NULL)
 224                return -ENOMEM;
 225
 226        /* Allocate TIPC port for socket to use */
 227
 228        tp_ptr = tipc_createport_raw(sk, &dispatch, &wakeupdispatch,
 229                                     TIPC_LOW_IMPORTANCE);
 230        if (unlikely(!tp_ptr)) {
 231                sk_free(sk);
 232                return -ENOMEM;
 233        }
 234
 235        /* Finish initializing socket data structures */
 236
 237        sock->ops = ops;
 238        sock->state = state;
 239
 240        sock_init_data(sock, sk);
 241        sk->sk_rcvtimeo = msecs_to_jiffies(CONN_TIMEOUT_DEFAULT);
 242        sk->sk_backlog_rcv = backlog_rcv;
 243        tipc_sk(sk)->p = tp_ptr;
 244
 245        spin_unlock_bh(tp_ptr->lock);
 246
 247        if (sock->state == SS_READY) {
 248                tipc_set_portunreturnable(tp_ptr->ref, 1);
 249                if (sock->type == SOCK_DGRAM)
 250                        tipc_set_portunreliable(tp_ptr->ref, 1);
 251        }
 252
 253        atomic_inc(&tipc_user_count);
 254        return 0;
 255}
 256
 257/**
 258 * release - destroy a TIPC socket
 259 * @sock: socket to destroy
 260 *
 261 * This routine cleans up any messages that are still queued on the socket.
 262 * For DGRAM and RDM socket types, all queued messages are rejected.
 263 * For SEQPACKET and STREAM socket types, the first message is rejected
 264 * and any others are discarded.  (If the first message on a STREAM socket
 265 * is partially-read, it is discarded and the next one is rejected instead.)
 266 *
 267 * NOTE: Rejected messages are not necessarily returned to the sender!  They
 268 * are returned or discarded according to the "destination droppable" setting
 269 * specified for the message by the sender.
 270 *
 271 * Returns 0 on success, errno otherwise
 272 */
 273
 274static int release(struct socket *sock)
 275{
 276        struct sock *sk = sock->sk;
 277        struct tipc_port *tport;
 278        struct sk_buff *buf;
 279        int res;
 280
 281        /*
 282         * Exit if socket isn't fully initialized (occurs when a failed accept()
 283         * releases a pre-allocated child socket that was never used)
 284         */
 285
 286        if (sk == NULL)
 287                return 0;
 288
 289        tport = tipc_sk_port(sk);
 290        lock_sock(sk);
 291
 292        /*
 293         * Reject all unreceived messages, except on an active connection
 294         * (which disconnects locally & sends a 'FIN+' to peer)
 295         */
 296
 297        while (sock->state != SS_DISCONNECTING) {
 298                buf = __skb_dequeue(&sk->sk_receive_queue);
 299                if (buf == NULL)
 300                        break;
 301                atomic_dec(&tipc_queue_size);
 302                if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf)))
 303                        buf_discard(buf);
 304                else {
 305                        if ((sock->state == SS_CONNECTING) ||
 306                            (sock->state == SS_CONNECTED)) {
 307                                sock->state = SS_DISCONNECTING;
 308                                tipc_disconnect(tport->ref);
 309                        }
 310                        tipc_reject_msg(buf, TIPC_ERR_NO_PORT);
 311                }
 312        }
 313
 314        /*
 315         * Delete TIPC port; this ensures no more messages are queued
 316         * (also disconnects an active connection & sends a 'FIN-' to peer)
 317         */
 318
 319        res = tipc_deleteport(tport->ref);
 320
 321        /* Discard any remaining (connection-based) messages in receive queue */
 322
 323        discard_rx_queue(sk);
 324
 325        /* Reject any messages that accumulated in backlog queue */
 326
 327        sock->state = SS_DISCONNECTING;
 328        release_sock(sk);
 329
 330        sock_put(sk);
 331        sock->sk = NULL;
 332
 333        atomic_dec(&tipc_user_count);
 334        return res;
 335}
 336
 337/**
 338 * bind - associate or disassocate TIPC name(s) with a socket
 339 * @sock: socket structure
 340 * @uaddr: socket address describing name(s) and desired operation
 341 * @uaddr_len: size of socket address data structure
 342 *
 343 * Name and name sequence binding is indicated using a positive scope value;
 344 * a negative scope value unbinds the specified name.  Specifying no name
 345 * (i.e. a socket address length of 0) unbinds all names from the socket.
 346 *
 347 * Returns 0 on success, errno otherwise
 348 *
 349 * NOTE: This routine doesn't need to take the socket lock since it doesn't
 350 *       access any non-constant socket information.
 351 */
 352
 353static int bind(struct socket *sock, struct sockaddr *uaddr, int uaddr_len)
 354{
 355        struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
 356        u32 portref = tipc_sk_port(sock->sk)->ref;
 357
 358        if (unlikely(!uaddr_len))
 359                return tipc_withdraw(portref, 0, NULL);
 360
 361        if (uaddr_len < sizeof(struct sockaddr_tipc))
 362                return -EINVAL;
 363        if (addr->family != AF_TIPC)
 364                return -EAFNOSUPPORT;
 365
 366        if (addr->addrtype == TIPC_ADDR_NAME)
 367                addr->addr.nameseq.upper = addr->addr.nameseq.lower;
 368        else if (addr->addrtype != TIPC_ADDR_NAMESEQ)
 369                return -EAFNOSUPPORT;
 370
 371        return (addr->scope > 0) ?
 372                tipc_publish(portref, addr->scope, &addr->addr.nameseq) :
 373                tipc_withdraw(portref, -addr->scope, &addr->addr.nameseq);
 374}
 375
 376/**
 377 * get_name - get port ID of socket or peer socket
 378 * @sock: socket structure
 379 * @uaddr: area for returned socket address
 380 * @uaddr_len: area for returned length of socket address
 381 * @peer: 0 = own ID, 1 = current peer ID, 2 = current/former peer ID
 382 *
 383 * Returns 0 on success, errno otherwise
 384 *
 385 * NOTE: This routine doesn't need to take the socket lock since it only
 386 *       accesses socket information that is unchanging (or which changes in
 387 *       a completely predictable manner).
 388 */
 389
 390static int get_name(struct socket *sock, struct sockaddr *uaddr,
 391                    int *uaddr_len, int peer)
 392{
 393        struct sockaddr_tipc *addr = (struct sockaddr_tipc *)uaddr;
 394        struct tipc_sock *tsock = tipc_sk(sock->sk);
 395
 396        if (peer) {
 397                if ((sock->state != SS_CONNECTED) &&
 398                        ((peer != 2) || (sock->state != SS_DISCONNECTING)))
 399                        return -ENOTCONN;
 400                addr->addr.id.ref = tsock->peer_name.ref;
 401                addr->addr.id.node = tsock->peer_name.node;
 402        } else {
 403                tipc_ownidentity(tsock->p->ref, &addr->addr.id);
 404        }
 405
 406        *uaddr_len = sizeof(*addr);
 407        addr->addrtype = TIPC_ADDR_ID;
 408        addr->family = AF_TIPC;
 409        addr->scope = 0;
 410        addr->addr.name.domain = 0;
 411
 412        return 0;
 413}
 414
 415/**
 416 * poll - read and possibly block on pollmask
 417 * @file: file structure associated with the socket
 418 * @sock: socket for which to calculate the poll bits
 419 * @wait: ???
 420 *
 421 * Returns pollmask value
 422 *
 423 * COMMENTARY:
 424 * It appears that the usual socket locking mechanisms are not useful here
 425 * since the pollmask info is potentially out-of-date the moment this routine
 426 * exits.  TCP and other protocols seem to rely on higher level poll routines
 427 * to handle any preventable race conditions, so TIPC will do the same ...
 428 *
 429 * TIPC sets the returned events as follows:
 430 * a) POLLRDNORM and POLLIN are set if the socket's receive queue is non-empty
 431 *    or if a connection-oriented socket is does not have an active connection
 432 *    (i.e. a read operation will not block).
 433 * b) POLLOUT is set except when a socket's connection has been terminated
 434 *    (i.e. a write operation will not block).
 435 * c) POLLHUP is set when a socket's connection has been terminated.
 436 *
 437 * IMPORTANT: The fact that a read or write operation will not block does NOT
 438 * imply that the operation will succeed!
 439 */
 440
 441static unsigned int poll(struct file *file, struct socket *sock,
 442                         poll_table *wait)
 443{
 444        struct sock *sk = sock->sk;
 445        u32 mask;
 446
 447        poll_wait(file, sk->sk_sleep, wait);
 448
 449        if (!skb_queue_empty(&sk->sk_receive_queue) ||
 450            (sock->state == SS_UNCONNECTED) ||
 451            (sock->state == SS_DISCONNECTING))
 452                mask = (POLLRDNORM | POLLIN);
 453        else
 454                mask = 0;
 455
 456        if (sock->state == SS_DISCONNECTING)
 457                mask |= POLLHUP;
 458        else
 459                mask |= POLLOUT;
 460
 461        return mask;
 462}
 463
 464/**
 465 * dest_name_check - verify user is permitted to send to specified port name
 466 * @dest: destination address
 467 * @m: descriptor for message to be sent
 468 *
 469 * Prevents restricted configuration commands from being issued by
 470 * unauthorized users.
 471 *
 472 * Returns 0 if permission is granted, otherwise errno
 473 */
 474
 475static int dest_name_check(struct sockaddr_tipc *dest, struct msghdr *m)
 476{
 477        struct tipc_cfg_msg_hdr hdr;
 478
 479        if (likely(dest->addr.name.name.type >= TIPC_RESERVED_TYPES))
 480                return 0;
 481        if (likely(dest->addr.name.name.type == TIPC_TOP_SRV))
 482                return 0;
 483        if (likely(dest->addr.name.name.type != TIPC_CFG_SRV))
 484                return -EACCES;
 485
 486        if (copy_from_user(&hdr, m->msg_iov[0].iov_base, sizeof(hdr)))
 487                return -EFAULT;
 488        if ((ntohs(hdr.tcm_type) & 0xC000) && (!capable(CAP_NET_ADMIN)))
 489                return -EACCES;
 490
 491        return 0;
 492}
 493
 494/**
 495 * send_msg - send message in connectionless manner
 496 * @iocb: if NULL, indicates that socket lock is already held
 497 * @sock: socket structure
 498 * @m: message to send
 499 * @total_len: length of message
 500 *
 501 * Message must have an destination specified explicitly.
 502 * Used for SOCK_RDM and SOCK_DGRAM messages,
 503 * and for 'SYN' messages on SOCK_SEQPACKET and SOCK_STREAM connections.
 504 * (Note: 'SYN+' is prohibited on SOCK_STREAM.)
 505 *
 506 * Returns the number of bytes sent on success, or errno otherwise
 507 */
 508
 509static int send_msg(struct kiocb *iocb, struct socket *sock,
 510                    struct msghdr *m, size_t total_len)
 511{
 512        struct sock *sk = sock->sk;
 513        struct tipc_port *tport = tipc_sk_port(sk);
 514        struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
 515        int needs_conn;
 516        int res = -EINVAL;
 517
 518        if (unlikely(!dest))
 519                return -EDESTADDRREQ;
 520        if (unlikely((m->msg_namelen < sizeof(*dest)) ||
 521                     (dest->family != AF_TIPC)))
 522                return -EINVAL;
 523
 524        if (iocb)
 525                lock_sock(sk);
 526
 527        needs_conn = (sock->state != SS_READY);
 528        if (unlikely(needs_conn)) {
 529                if (sock->state == SS_LISTENING) {
 530                        res = -EPIPE;
 531                        goto exit;
 532                }
 533                if (sock->state != SS_UNCONNECTED) {
 534                        res = -EISCONN;
 535                        goto exit;
 536                }
 537                if ((tport->published) ||
 538                    ((sock->type == SOCK_STREAM) && (total_len != 0))) {
 539                        res = -EOPNOTSUPP;
 540                        goto exit;
 541                }
 542                if (dest->addrtype == TIPC_ADDR_NAME) {
 543                        tport->conn_type = dest->addr.name.name.type;
 544                        tport->conn_instance = dest->addr.name.name.instance;
 545                }
 546
 547                /* Abort any pending connection attempts (very unlikely) */
 548
 549                reject_rx_queue(sk);
 550        }
 551
 552        do {
 553                if (dest->addrtype == TIPC_ADDR_NAME) {
 554                        if ((res = dest_name_check(dest, m)))
 555                                break;
 556                        res = tipc_send2name(tport->ref,
 557                                             &dest->addr.name.name,
 558                                             dest->addr.name.domain,
 559                                             m->msg_iovlen,
 560                                             m->msg_iov);
 561                }
 562                else if (dest->addrtype == TIPC_ADDR_ID) {
 563                        res = tipc_send2port(tport->ref,
 564                                             &dest->addr.id,
 565                                             m->msg_iovlen,
 566                                             m->msg_iov);
 567                }
 568                else if (dest->addrtype == TIPC_ADDR_MCAST) {
 569                        if (needs_conn) {
 570                                res = -EOPNOTSUPP;
 571                                break;
 572                        }
 573                        if ((res = dest_name_check(dest, m)))
 574                                break;
 575                        res = tipc_multicast(tport->ref,
 576                                             &dest->addr.nameseq,
 577                                             0,
 578                                             m->msg_iovlen,
 579                                             m->msg_iov);
 580                }
 581                if (likely(res != -ELINKCONG)) {
 582                        if (needs_conn && (res >= 0)) {
 583                                sock->state = SS_CONNECTING;
 584                        }
 585                        break;
 586                }
 587                if (m->msg_flags & MSG_DONTWAIT) {
 588                        res = -EWOULDBLOCK;
 589                        break;
 590                }
 591                release_sock(sk);
 592                res = wait_event_interruptible(*sk->sk_sleep,
 593                                               !tport->congested);
 594                lock_sock(sk);
 595                if (res)
 596                        break;
 597        } while (1);
 598
 599exit:
 600        if (iocb)
 601                release_sock(sk);
 602        return res;
 603}
 604
 605/**
 606 * send_packet - send a connection-oriented message
 607 * @iocb: if NULL, indicates that socket lock is already held
 608 * @sock: socket structure
 609 * @m: message to send
 610 * @total_len: length of message
 611 *
 612 * Used for SOCK_SEQPACKET messages and SOCK_STREAM data.
 613 *
 614 * Returns the number of bytes sent on success, or errno otherwise
 615 */
 616
 617static int send_packet(struct kiocb *iocb, struct socket *sock,
 618                       struct msghdr *m, size_t total_len)
 619{
 620        struct sock *sk = sock->sk;
 621        struct tipc_port *tport = tipc_sk_port(sk);
 622        struct sockaddr_tipc *dest = (struct sockaddr_tipc *)m->msg_name;
 623        int res;
 624
 625        /* Handle implied connection establishment */
 626
 627        if (unlikely(dest))
 628                return send_msg(iocb, sock, m, total_len);
 629
 630        if (iocb)
 631                lock_sock(sk);
 632
 633        do {
 634                if (unlikely(sock->state != SS_CONNECTED)) {
 635                        if (sock->state == SS_DISCONNECTING)
 636                                res = -EPIPE;
 637                        else
 638                                res = -ENOTCONN;
 639                        break;
 640                }
 641
 642                res = tipc_send(tport->ref, m->msg_iovlen, m->msg_iov);
 643                if (likely(res != -ELINKCONG)) {
 644                        break;
 645                }
 646                if (m->msg_flags & MSG_DONTWAIT) {
 647                        res = -EWOULDBLOCK;
 648                        break;
 649                }
 650                release_sock(sk);
 651                res = wait_event_interruptible(*sk->sk_sleep,
 652                        (!tport->congested || !tport->connected));
 653                lock_sock(sk);
 654                if (res)
 655                        break;
 656        } while (1);
 657
 658        if (iocb)
 659                release_sock(sk);
 660        return res;
 661}
 662
 663/**
 664 * send_stream - send stream-oriented data
 665 * @iocb: (unused)
 666 * @sock: socket structure
 667 * @m: data to send
 668 * @total_len: total length of data to be sent
 669 *
 670 * Used for SOCK_STREAM data.
 671 *
 672 * Returns the number of bytes sent on success (or partial success),
 673 * or errno if no data sent
 674 */
 675
 676static int send_stream(struct kiocb *iocb, struct socket *sock,
 677                       struct msghdr *m, size_t total_len)
 678{
 679        struct sock *sk = sock->sk;
 680        struct tipc_port *tport = tipc_sk_port(sk);
 681        struct msghdr my_msg;
 682        struct iovec my_iov;
 683        struct iovec *curr_iov;
 684        int curr_iovlen;
 685        char __user *curr_start;
 686        u32 hdr_size;
 687        int curr_left;
 688        int bytes_to_send;
 689        int bytes_sent;
 690        int res;
 691
 692        lock_sock(sk);
 693
 694        /* Handle special cases where there is no connection */
 695
 696        if (unlikely(sock->state != SS_CONNECTED)) {
 697                if (sock->state == SS_UNCONNECTED) {
 698                        res = send_packet(NULL, sock, m, total_len);
 699                        goto exit;
 700                } else if (sock->state == SS_DISCONNECTING) {
 701                        res = -EPIPE;
 702                        goto exit;
 703                } else {
 704                        res = -ENOTCONN;
 705                        goto exit;
 706                }
 707        }
 708
 709        if (unlikely(m->msg_name)) {
 710                res = -EISCONN;
 711                goto exit;
 712        }
 713
 714        /*
 715         * Send each iovec entry using one or more messages
 716         *
 717         * Note: This algorithm is good for the most likely case
 718         * (i.e. one large iovec entry), but could be improved to pass sets
 719         * of small iovec entries into send_packet().
 720         */
 721
 722        curr_iov = m->msg_iov;
 723        curr_iovlen = m->msg_iovlen;
 724        my_msg.msg_iov = &my_iov;
 725        my_msg.msg_iovlen = 1;
 726        my_msg.msg_flags = m->msg_flags;
 727        my_msg.msg_name = NULL;
 728        bytes_sent = 0;
 729
 730        hdr_size = msg_hdr_sz(&tport->phdr);
 731
 732        while (curr_iovlen--) {
 733                curr_start = curr_iov->iov_base;
 734                curr_left = curr_iov->iov_len;
 735
 736                while (curr_left) {
 737                        bytes_to_send = tport->max_pkt - hdr_size;
 738                        if (bytes_to_send > TIPC_MAX_USER_MSG_SIZE)
 739                                bytes_to_send = TIPC_MAX_USER_MSG_SIZE;
 740                        if (curr_left < bytes_to_send)
 741                                bytes_to_send = curr_left;
 742                        my_iov.iov_base = curr_start;
 743                        my_iov.iov_len = bytes_to_send;
 744                        if ((res = send_packet(NULL, sock, &my_msg, 0)) < 0) {
 745                                if (bytes_sent)
 746                                        res = bytes_sent;
 747                                goto exit;
 748                        }
 749                        curr_left -= bytes_to_send;
 750                        curr_start += bytes_to_send;
 751                        bytes_sent += bytes_to_send;
 752                }
 753
 754                curr_iov++;
 755        }
 756        res = bytes_sent;
 757exit:
 758        release_sock(sk);
 759        return res;
 760}
 761
 762/**
 763 * auto_connect - complete connection setup to a remote port
 764 * @sock: socket structure
 765 * @msg: peer's response message
 766 *
 767 * Returns 0 on success, errno otherwise
 768 */
 769
 770static int auto_connect(struct socket *sock, struct tipc_msg *msg)
 771{
 772        struct tipc_sock *tsock = tipc_sk(sock->sk);
 773
 774        if (msg_errcode(msg)) {
 775                sock->state = SS_DISCONNECTING;
 776                return -ECONNREFUSED;
 777        }
 778
 779        tsock->peer_name.ref = msg_origport(msg);
 780        tsock->peer_name.node = msg_orignode(msg);
 781        tipc_connect2port(tsock->p->ref, &tsock->peer_name);
 782        tipc_set_portimportance(tsock->p->ref, msg_importance(msg));
 783        sock->state = SS_CONNECTED;
 784        return 0;
 785}
 786
 787/**
 788 * set_orig_addr - capture sender's address for received message
 789 * @m: descriptor for message info
 790 * @msg: received message header
 791 *
 792 * Note: Address is not captured if not requested by receiver.
 793 */
 794
 795static void set_orig_addr(struct msghdr *m, struct tipc_msg *msg)
 796{
 797        struct sockaddr_tipc *addr = (struct sockaddr_tipc *)m->msg_name;
 798
 799        if (addr) {
 800                addr->family = AF_TIPC;
 801                addr->addrtype = TIPC_ADDR_ID;
 802                addr->addr.id.ref = msg_origport(msg);
 803                addr->addr.id.node = msg_orignode(msg);
 804                addr->addr.name.domain = 0;     /* could leave uninitialized */
 805                addr->scope = 0;                /* could leave uninitialized */
 806                m->msg_namelen = sizeof(struct sockaddr_tipc);
 807        }
 808}
 809
 810/**
 811 * anc_data_recv - optionally capture ancillary data for received message
 812 * @m: descriptor for message info
 813 * @msg: received message header
 814 * @tport: TIPC port associated with message
 815 *
 816 * Note: Ancillary data is not captured if not requested by receiver.
 817 *
 818 * Returns 0 if successful, otherwise errno
 819 */
 820
 821static int anc_data_recv(struct msghdr *m, struct tipc_msg *msg,
 822                                struct tipc_port *tport)
 823{
 824        u32 anc_data[3];
 825        u32 err;
 826        u32 dest_type;
 827        int has_name;
 828        int res;
 829
 830        if (likely(m->msg_controllen == 0))
 831                return 0;
 832
 833        /* Optionally capture errored message object(s) */
 834
 835        err = msg ? msg_errcode(msg) : 0;
 836        if (unlikely(err)) {
 837                anc_data[0] = err;
 838                anc_data[1] = msg_data_sz(msg);
 839                if ((res = put_cmsg(m, SOL_TIPC, TIPC_ERRINFO, 8, anc_data)))
 840                        return res;
 841                if (anc_data[1] &&
 842                    (res = put_cmsg(m, SOL_TIPC, TIPC_RETDATA, anc_data[1],
 843                                    msg_data(msg))))
 844                        return res;
 845        }
 846
 847        /* Optionally capture message destination object */
 848
 849        dest_type = msg ? msg_type(msg) : TIPC_DIRECT_MSG;
 850        switch (dest_type) {
 851        case TIPC_NAMED_MSG:
 852                has_name = 1;
 853                anc_data[0] = msg_nametype(msg);
 854                anc_data[1] = msg_namelower(msg);
 855                anc_data[2] = msg_namelower(msg);
 856                break;
 857        case TIPC_MCAST_MSG:
 858                has_name = 1;
 859                anc_data[0] = msg_nametype(msg);
 860                anc_data[1] = msg_namelower(msg);
 861                anc_data[2] = msg_nameupper(msg);
 862                break;
 863        case TIPC_CONN_MSG:
 864                has_name = (tport->conn_type != 0);
 865                anc_data[0] = tport->conn_type;
 866                anc_data[1] = tport->conn_instance;
 867                anc_data[2] = tport->conn_instance;
 868                break;
 869        default:
 870                has_name = 0;
 871        }
 872        if (has_name &&
 873            (res = put_cmsg(m, SOL_TIPC, TIPC_DESTNAME, 12, anc_data)))
 874                return res;
 875
 876        return 0;
 877}
 878
 879/**
 880 * recv_msg - receive packet-oriented message
 881 * @iocb: (unused)
 882 * @m: descriptor for message info
 883 * @buf_len: total size of user buffer area
 884 * @flags: receive flags
 885 *
 886 * Used for SOCK_DGRAM, SOCK_RDM, and SOCK_SEQPACKET messages.
 887 * If the complete message doesn't fit in user area, truncate it.
 888 *
 889 * Returns size of returned message data, errno otherwise
 890 */
 891
 892static int recv_msg(struct kiocb *iocb, struct socket *sock,
 893                    struct msghdr *m, size_t buf_len, int flags)
 894{
 895        struct sock *sk = sock->sk;
 896        struct tipc_port *tport = tipc_sk_port(sk);
 897        struct sk_buff *buf;
 898        struct tipc_msg *msg;
 899        unsigned int sz;
 900        u32 err;
 901        int res;
 902
 903        /* Catch invalid receive requests */
 904
 905        if (m->msg_iovlen != 1)
 906                return -EOPNOTSUPP;   /* Don't do multiple iovec entries yet */
 907
 908        if (unlikely(!buf_len))
 909                return -EINVAL;
 910
 911        lock_sock(sk);
 912
 913        if (unlikely(sock->state == SS_UNCONNECTED)) {
 914                res = -ENOTCONN;
 915                goto exit;
 916        }
 917
 918restart:
 919
 920        /* Look for a message in receive queue; wait if necessary */
 921
 922        while (skb_queue_empty(&sk->sk_receive_queue)) {
 923                if (sock->state == SS_DISCONNECTING) {
 924                        res = -ENOTCONN;
 925                        goto exit;
 926                }
 927                if (flags & MSG_DONTWAIT) {
 928                        res = -EWOULDBLOCK;
 929                        goto exit;
 930                }
 931                release_sock(sk);
 932                res = wait_event_interruptible(*sk->sk_sleep,
 933                        (!skb_queue_empty(&sk->sk_receive_queue) ||
 934                         (sock->state == SS_DISCONNECTING)));
 935                lock_sock(sk);
 936                if (res)
 937                        goto exit;
 938        }
 939
 940        /* Look at first message in receive queue */
 941
 942        buf = skb_peek(&sk->sk_receive_queue);
 943        msg = buf_msg(buf);
 944        sz = msg_data_sz(msg);
 945        err = msg_errcode(msg);
 946
 947        /* Complete connection setup for an implied connect */
 948
 949        if (unlikely(sock->state == SS_CONNECTING)) {
 950                res = auto_connect(sock, msg);
 951                if (res)
 952                        goto exit;
 953        }
 954
 955        /* Discard an empty non-errored message & try again */
 956
 957        if ((!sz) && (!err)) {
 958                advance_rx_queue(sk);
 959                goto restart;
 960        }
 961
 962        /* Capture sender's address (optional) */
 963
 964        set_orig_addr(m, msg);
 965
 966        /* Capture ancillary data (optional) */
 967
 968        res = anc_data_recv(m, msg, tport);
 969        if (res)
 970                goto exit;
 971
 972        /* Capture message data (if valid) & compute return value (always) */
 973
 974        if (!err) {
 975                if (unlikely(buf_len < sz)) {
 976                        sz = buf_len;
 977                        m->msg_flags |= MSG_TRUNC;
 978                }
 979                if (unlikely(copy_to_user(m->msg_iov->iov_base, msg_data(msg),
 980                                          sz))) {
 981                        res = -EFAULT;
 982                        goto exit;
 983                }
 984                res = sz;
 985        } else {
 986                if ((sock->state == SS_READY) ||
 987                    ((err == TIPC_CONN_SHUTDOWN) || m->msg_control))
 988                        res = 0;
 989                else
 990                        res = -ECONNRESET;
 991        }
 992
 993        /* Consume received message (optional) */
 994
 995        if (likely(!(flags & MSG_PEEK))) {
 996                if ((sock->state != SS_READY) &&
 997                    (++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
 998                        tipc_acknowledge(tport->ref, tport->conn_unacked);
 999                advance_rx_queue(sk);
1000        }
1001exit:
1002        release_sock(sk);
1003        return res;
1004}
1005
1006/**
1007 * recv_stream - receive stream-oriented data
1008 * @iocb: (unused)
1009 * @m: descriptor for message info
1010 * @buf_len: total size of user buffer area
1011 * @flags: receive flags
1012 *
1013 * Used for SOCK_STREAM messages only.  If not enough data is available
1014 * will optionally wait for more; never truncates data.
1015 *
1016 * Returns size of returned message data, errno otherwise
1017 */
1018
1019static int recv_stream(struct kiocb *iocb, struct socket *sock,
1020                       struct msghdr *m, size_t buf_len, int flags)
1021{
1022        struct sock *sk = sock->sk;
1023        struct tipc_port *tport = tipc_sk_port(sk);
1024        struct sk_buff *buf;
1025        struct tipc_msg *msg;
1026        unsigned int sz;
1027        int sz_to_copy;
1028        int sz_copied = 0;
1029        int needed;
1030        char __user *crs = m->msg_iov->iov_base;
1031        unsigned char *buf_crs;
1032        u32 err;
1033        int res = 0;
1034
1035        /* Catch invalid receive attempts */
1036
1037        if (m->msg_iovlen != 1)
1038                return -EOPNOTSUPP;   /* Don't do multiple iovec entries yet */
1039
1040        if (unlikely(!buf_len))
1041                return -EINVAL;
1042
1043        lock_sock(sk);
1044
1045        if (unlikely((sock->state == SS_UNCONNECTED) ||
1046                     (sock->state == SS_CONNECTING))) {
1047                res = -ENOTCONN;
1048                goto exit;
1049        }
1050
1051restart:
1052
1053        /* Look for a message in receive queue; wait if necessary */
1054
1055        while (skb_queue_empty(&sk->sk_receive_queue)) {
1056                if (sock->state == SS_DISCONNECTING) {
1057                        res = -ENOTCONN;
1058                        goto exit;
1059                }
1060                if (flags & MSG_DONTWAIT) {
1061                        res = -EWOULDBLOCK;
1062                        goto exit;
1063                }
1064                release_sock(sk);
1065                res = wait_event_interruptible(*sk->sk_sleep,
1066                        (!skb_queue_empty(&sk->sk_receive_queue) ||
1067                         (sock->state == SS_DISCONNECTING)));
1068                lock_sock(sk);
1069                if (res)
1070                        goto exit;
1071        }
1072
1073        /* Look at first message in receive queue */
1074
1075        buf = skb_peek(&sk->sk_receive_queue);
1076        msg = buf_msg(buf);
1077        sz = msg_data_sz(msg);
1078        err = msg_errcode(msg);
1079
1080        /* Discard an empty non-errored message & try again */
1081
1082        if ((!sz) && (!err)) {
1083                advance_rx_queue(sk);
1084                goto restart;
1085        }
1086
1087        /* Optionally capture sender's address & ancillary data of first msg */
1088
1089        if (sz_copied == 0) {
1090                set_orig_addr(m, msg);
1091                res = anc_data_recv(m, msg, tport);
1092                if (res)
1093                        goto exit;
1094        }
1095
1096        /* Capture message data (if valid) & compute return value (always) */
1097
1098        if (!err) {
1099                buf_crs = (unsigned char *)(TIPC_SKB_CB(buf)->handle);
1100                sz = (unsigned char *)msg + msg_size(msg) - buf_crs;
1101
1102                needed = (buf_len - sz_copied);
1103                sz_to_copy = (sz <= needed) ? sz : needed;
1104                if (unlikely(copy_to_user(crs, buf_crs, sz_to_copy))) {
1105                        res = -EFAULT;
1106                        goto exit;
1107                }
1108                sz_copied += sz_to_copy;
1109
1110                if (sz_to_copy < sz) {
1111                        if (!(flags & MSG_PEEK))
1112                                TIPC_SKB_CB(buf)->handle = buf_crs + sz_to_copy;
1113                        goto exit;
1114                }
1115
1116                crs += sz_to_copy;
1117        } else {
1118                if (sz_copied != 0)
1119                        goto exit; /* can't add error msg to valid data */
1120
1121                if ((err == TIPC_CONN_SHUTDOWN) || m->msg_control)
1122                        res = 0;
1123                else
1124                        res = -ECONNRESET;
1125        }
1126
1127        /* Consume received message (optional) */
1128
1129        if (likely(!(flags & MSG_PEEK))) {
1130                if (unlikely(++tport->conn_unacked >= TIPC_FLOW_CONTROL_WIN))
1131                        tipc_acknowledge(tport->ref, tport->conn_unacked);
1132                advance_rx_queue(sk);
1133        }
1134
1135        /* Loop around if more data is required */
1136
1137        if ((sz_copied < buf_len)    /* didn't get all requested data */
1138            && (!skb_queue_empty(&sk->sk_receive_queue) ||
1139                (flags & MSG_WAITALL))
1140                                     /* ... and more is ready or required */
1141            && (!(flags & MSG_PEEK)) /* ... and aren't just peeking at data */
1142            && (!err)                /* ... and haven't reached a FIN */
1143            )
1144                goto restart;
1145
1146exit:
1147        release_sock(sk);
1148        return sz_copied ? sz_copied : res;
1149}
1150
1151/**
1152 * rx_queue_full - determine if receive queue can accept another message
1153 * @msg: message to be added to queue
1154 * @queue_size: current size of queue
1155 * @base: nominal maximum size of queue
1156 *
1157 * Returns 1 if queue is unable to accept message, 0 otherwise
1158 */
1159
1160static int rx_queue_full(struct tipc_msg *msg, u32 queue_size, u32 base)
1161{
1162        u32 threshold;
1163        u32 imp = msg_importance(msg);
1164
1165        if (imp == TIPC_LOW_IMPORTANCE)
1166                threshold = base;
1167        else if (imp == TIPC_MEDIUM_IMPORTANCE)
1168                threshold = base * 2;
1169        else if (imp == TIPC_HIGH_IMPORTANCE)
1170                threshold = base * 100;
1171        else
1172                return 0;
1173
1174        if (msg_connected(msg))
1175                threshold *= 4;
1176
1177        return (queue_size >= threshold);
1178}
1179
1180/**
1181 * filter_rcv - validate incoming message
1182 * @sk: socket
1183 * @buf: message
1184 *
1185 * Enqueues message on receive queue if acceptable; optionally handles
1186 * disconnect indication for a connected socket.
1187 *
1188 * Called with socket lock already taken; port lock may also be taken.
1189 *
1190 * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
1191 */
1192
1193static u32 filter_rcv(struct sock *sk, struct sk_buff *buf)
1194{
1195        struct socket *sock = sk->sk_socket;
1196        struct tipc_msg *msg = buf_msg(buf);
1197        u32 recv_q_len;
1198
1199        /* Reject message if it is wrong sort of message for socket */
1200
1201        /*
1202         * WOULD IT BE BETTER TO JUST DISCARD THESE MESSAGES INSTEAD?
1203         * "NO PORT" ISN'T REALLY THE RIGHT ERROR CODE, AND THERE MAY
1204         * BE SECURITY IMPLICATIONS INHERENT IN REJECTING INVALID TRAFFIC
1205         */
1206
1207        if (sock->state == SS_READY) {
1208                if (msg_connected(msg)) {
1209                        msg_dbg(msg, "dispatch filter 1\n");
1210                        return TIPC_ERR_NO_PORT;
1211                }
1212        } else {
1213                if (msg_mcast(msg)) {
1214                        msg_dbg(msg, "dispatch filter 2\n");
1215                        return TIPC_ERR_NO_PORT;
1216                }
1217                if (sock->state == SS_CONNECTED) {
1218                        if (!msg_connected(msg)) {
1219                                msg_dbg(msg, "dispatch filter 3\n");
1220                                return TIPC_ERR_NO_PORT;
1221                        }
1222                }
1223                else if (sock->state == SS_CONNECTING) {
1224                        if (!msg_connected(msg) && (msg_errcode(msg) == 0)) {
1225                                msg_dbg(msg, "dispatch filter 4\n");
1226                                return TIPC_ERR_NO_PORT;
1227                        }
1228                }
1229                else if (sock->state == SS_LISTENING) {
1230                        if (msg_connected(msg) || msg_errcode(msg)) {
1231                                msg_dbg(msg, "dispatch filter 5\n");
1232                                return TIPC_ERR_NO_PORT;
1233                        }
1234                }
1235                else if (sock->state == SS_DISCONNECTING) {
1236                        msg_dbg(msg, "dispatch filter 6\n");
1237                        return TIPC_ERR_NO_PORT;
1238                }
1239                else /* (sock->state == SS_UNCONNECTED) */ {
1240                        if (msg_connected(msg) || msg_errcode(msg)) {
1241                                msg_dbg(msg, "dispatch filter 7\n");
1242                                return TIPC_ERR_NO_PORT;
1243                        }
1244                }
1245        }
1246
1247        /* Reject message if there isn't room to queue it */
1248
1249        recv_q_len = (u32)atomic_read(&tipc_queue_size);
1250        if (unlikely(recv_q_len >= OVERLOAD_LIMIT_BASE)) {
1251                if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE))
1252                        return TIPC_ERR_OVERLOAD;
1253        }
1254        recv_q_len = skb_queue_len(&sk->sk_receive_queue);
1255        if (unlikely(recv_q_len >= (OVERLOAD_LIMIT_BASE / 2))) {
1256                if (rx_queue_full(msg, recv_q_len, OVERLOAD_LIMIT_BASE / 2))
1257                        return TIPC_ERR_OVERLOAD;
1258        }
1259
1260        /* Enqueue message (finally!) */
1261
1262        msg_dbg(msg, "<DISP<: ");
1263        TIPC_SKB_CB(buf)->handle = msg_data(msg);
1264        atomic_inc(&tipc_queue_size);
1265        __skb_queue_tail(&sk->sk_receive_queue, buf);
1266
1267        /* Initiate connection termination for an incoming 'FIN' */
1268
1269        if (unlikely(msg_errcode(msg) && (sock->state == SS_CONNECTED))) {
1270                sock->state = SS_DISCONNECTING;
1271                tipc_disconnect_port(tipc_sk_port(sk));
1272        }
1273
1274        if (waitqueue_active(sk->sk_sleep))
1275                wake_up_interruptible(sk->sk_sleep);
1276        return TIPC_OK;
1277}
1278
1279/**
1280 * backlog_rcv - handle incoming message from backlog queue
1281 * @sk: socket
1282 * @buf: message
1283 *
1284 * Caller must hold socket lock, but not port lock.
1285 *
1286 * Returns 0
1287 */
1288
1289static int backlog_rcv(struct sock *sk, struct sk_buff *buf)
1290{
1291        u32 res;
1292
1293        res = filter_rcv(sk, buf);
1294        if (res)
1295                tipc_reject_msg(buf, res);
1296        return 0;
1297}
1298
1299/**
1300 * dispatch - handle incoming message
1301 * @tport: TIPC port that received message
1302 * @buf: message
1303 *
1304 * Called with port lock already taken.
1305 *
1306 * Returns TIPC error status code (TIPC_OK if message is not to be rejected)
1307 */
1308
1309static u32 dispatch(struct tipc_port *tport, struct sk_buff *buf)
1310{
1311        struct sock *sk = (struct sock *)tport->usr_handle;
1312        u32 res;
1313
1314        /*
1315         * Process message if socket is unlocked; otherwise add to backlog queue
1316         *
1317         * This code is based on sk_receive_skb(), but must be distinct from it
1318         * since a TIPC-specific filter/reject mechanism is utilized
1319         */
1320
1321        bh_lock_sock(sk);
1322        if (!sock_owned_by_user(sk)) {
1323                res = filter_rcv(sk, buf);
1324        } else {
1325                sk_add_backlog(sk, buf);
1326                res = TIPC_OK;
1327        }
1328        bh_unlock_sock(sk);
1329
1330        return res;
1331}
1332
1333/**
1334 * wakeupdispatch - wake up port after congestion
1335 * @tport: port to wakeup
1336 *
1337 * Called with port lock already taken.
1338 */
1339
1340static void wakeupdispatch(struct tipc_port *tport)
1341{
1342        struct sock *sk = (struct sock *)tport->usr_handle;
1343
1344        if (waitqueue_active(sk->sk_sleep))
1345                wake_up_interruptible(sk->sk_sleep);
1346}
1347
1348/**
1349 * connect - establish a connection to another TIPC port
1350 * @sock: socket structure
1351 * @dest: socket address for destination port
1352 * @destlen: size of socket address data structure
1353 * @flags: file-related flags associated with socket
1354 *
1355 * Returns 0 on success, errno otherwise
1356 */
1357
1358static int connect(struct socket *sock, struct sockaddr *dest, int destlen,
1359                   int flags)
1360{
1361        struct sock *sk = sock->sk;
1362        struct sockaddr_tipc *dst = (struct sockaddr_tipc *)dest;
1363        struct msghdr m = {NULL,};
1364        struct sk_buff *buf;
1365        struct tipc_msg *msg;
1366        int res;
1367
1368        lock_sock(sk);
1369
1370        /* For now, TIPC does not allow use of connect() with DGRAM/RDM types */
1371
1372        if (sock->state == SS_READY) {
1373                res = -EOPNOTSUPP;
1374                goto exit;
1375        }
1376
1377        /* For now, TIPC does not support the non-blocking form of connect() */
1378
1379        if (flags & O_NONBLOCK) {
1380                res = -EWOULDBLOCK;
1381                goto exit;
1382        }
1383
1384        /* Issue Posix-compliant error code if socket is in the wrong state */
1385
1386        if (sock->state == SS_LISTENING) {
1387                res = -EOPNOTSUPP;
1388                goto exit;
1389        }
1390        if (sock->state == SS_CONNECTING) {
1391                res = -EALREADY;
1392                goto exit;
1393        }
1394        if (sock->state != SS_UNCONNECTED) {
1395                res = -EISCONN;
1396                goto exit;
1397        }
1398
1399        /*
1400         * Reject connection attempt using multicast address
1401         *
1402         * Note: send_msg() validates the rest of the address fields,
1403         *       so there's no need to do it here
1404         */
1405
1406        if (dst->addrtype == TIPC_ADDR_MCAST) {
1407                res = -EINVAL;
1408                goto exit;
1409        }
1410
1411        /* Reject any messages already in receive queue (very unlikely) */
1412
1413        reject_rx_queue(sk);
1414
1415        /* Send a 'SYN-' to destination */
1416
1417        m.msg_name = dest;
1418        m.msg_namelen = destlen;
1419        res = send_msg(NULL, sock, &m, 0);
1420        if (res < 0) {
1421                goto exit;
1422        }
1423
1424        /* Wait until an 'ACK' or 'RST' arrives, or a timeout occurs */
1425
1426        release_sock(sk);
1427        res = wait_event_interruptible_timeout(*sk->sk_sleep,
1428                        (!skb_queue_empty(&sk->sk_receive_queue) ||
1429                        (sock->state != SS_CONNECTING)),
1430                        sk->sk_rcvtimeo);
1431        lock_sock(sk);
1432
1433        if (res > 0) {
1434                buf = skb_peek(&sk->sk_receive_queue);
1435                if (buf != NULL) {
1436                        msg = buf_msg(buf);
1437                        res = auto_connect(sock, msg);
1438                        if (!res) {
1439                                if (!msg_data_sz(msg))
1440                                        advance_rx_queue(sk);
1441                        }
1442                } else {
1443                        if (sock->state == SS_CONNECTED) {
1444                                res = -EISCONN;
1445                        } else {
1446                                res = -ECONNREFUSED;
1447                        }
1448                }
1449        } else {
1450                if (res == 0)
1451                        res = -ETIMEDOUT;
1452                else
1453                        ; /* leave "res" unchanged */
1454                sock->state = SS_DISCONNECTING;
1455        }
1456
1457exit:
1458        release_sock(sk);
1459        return res;
1460}
1461
1462/**
1463 * listen - allow socket to listen for incoming connections
1464 * @sock: socket structure
1465 * @len: (unused)
1466 *
1467 * Returns 0 on success, errno otherwise
1468 */
1469
1470static int listen(struct socket *sock, int len)
1471{
1472        struct sock *sk = sock->sk;
1473        int res;
1474
1475        lock_sock(sk);
1476
1477        if (sock->state == SS_READY)
1478                res = -EOPNOTSUPP;
1479        else if (sock->state != SS_UNCONNECTED)
1480                res = -EINVAL;
1481        else {
1482                sock->state = SS_LISTENING;
1483                res = 0;
1484        }
1485
1486        release_sock(sk);
1487        return res;
1488}
1489
1490/**
1491 * accept - wait for connection request
1492 * @sock: listening socket
1493 * @newsock: new socket that is to be connected
1494 * @flags: file-related flags associated with socket
1495 *
1496 * Returns 0 on success, errno otherwise
1497 */
1498
1499static int accept(struct socket *sock, struct socket *new_sock, int flags)
1500{
1501        struct sock *sk = sock->sk;
1502        struct sk_buff *buf;
1503        int res;
1504
1505        lock_sock(sk);
1506
1507        if (sock->state == SS_READY) {
1508                res = -EOPNOTSUPP;
1509                goto exit;
1510        }
1511        if (sock->state != SS_LISTENING) {
1512                res = -EINVAL;
1513                goto exit;
1514        }
1515
1516        while (skb_queue_empty(&sk->sk_receive_queue)) {
1517                if (flags & O_NONBLOCK) {
1518                        res = -EWOULDBLOCK;
1519                        goto exit;
1520                }
1521                release_sock(sk);
1522                res = wait_event_interruptible(*sk->sk_sleep,
1523                                (!skb_queue_empty(&sk->sk_receive_queue)));
1524                lock_sock(sk);
1525                if (res)
1526                        goto exit;
1527        }
1528
1529        buf = skb_peek(&sk->sk_receive_queue);
1530
1531        res = tipc_create(sock_net(sock->sk), new_sock, 0);
1532        if (!res) {
1533                struct sock *new_sk = new_sock->sk;
1534                struct tipc_sock *new_tsock = tipc_sk(new_sk);
1535                struct tipc_port *new_tport = new_tsock->p;
1536                u32 new_ref = new_tport->ref;
1537                struct tipc_msg *msg = buf_msg(buf);
1538
1539                lock_sock(new_sk);
1540
1541                /*
1542                 * Reject any stray messages received by new socket
1543                 * before the socket lock was taken (very, very unlikely)
1544                 */
1545
1546                reject_rx_queue(new_sk);
1547
1548                /* Connect new socket to it's peer */
1549
1550                new_tsock->peer_name.ref = msg_origport(msg);
1551                new_tsock->peer_name.node = msg_orignode(msg);
1552                tipc_connect2port(new_ref, &new_tsock->peer_name);
1553                new_sock->state = SS_CONNECTED;
1554
1555                tipc_set_portimportance(new_ref, msg_importance(msg));
1556                if (msg_named(msg)) {
1557                        new_tport->conn_type = msg_nametype(msg);
1558                        new_tport->conn_instance = msg_nameinst(msg);
1559                }
1560
1561                /*
1562                 * Respond to 'SYN-' by discarding it & returning 'ACK'-.
1563                 * Respond to 'SYN+' by queuing it on new socket.
1564                 */
1565
1566                msg_dbg(msg,"<ACC<: ");
1567                if (!msg_data_sz(msg)) {
1568                        struct msghdr m = {NULL,};
1569
1570                        advance_rx_queue(sk);
1571                        send_packet(NULL, new_sock, &m, 0);
1572                } else {
1573                        __skb_dequeue(&sk->sk_receive_queue);
1574                        __skb_queue_head(&new_sk->sk_receive_queue, buf);
1575                }
1576                release_sock(new_sk);
1577        }
1578exit:
1579        release_sock(sk);
1580        return res;
1581}
1582
1583/**
1584 * shutdown - shutdown socket connection
1585 * @sock: socket structure
1586 * @how: direction to close (must be SHUT_RDWR)
1587 *
1588 * Terminates connection (if necessary), then purges socket's receive queue.
1589 *
1590 * Returns 0 on success, errno otherwise
1591 */
1592
1593static int shutdown(struct socket *sock, int how)
1594{
1595        struct sock *sk = sock->sk;
1596        struct tipc_port *tport = tipc_sk_port(sk);
1597        struct sk_buff *buf;
1598        int res;
1599
1600        if (how != SHUT_RDWR)
1601                return -EINVAL;
1602
1603        lock_sock(sk);
1604
1605        switch (sock->state) {
1606        case SS_CONNECTING:
1607        case SS_CONNECTED:
1608
1609                /* Disconnect and send a 'FIN+' or 'FIN-' message to peer */
1610restart:
1611                buf = __skb_dequeue(&sk->sk_receive_queue);
1612                if (buf) {
1613                        atomic_dec(&tipc_queue_size);
1614                        if (TIPC_SKB_CB(buf)->handle != msg_data(buf_msg(buf))) {
1615                                buf_discard(buf);
1616                                goto restart;
1617                        }
1618                        tipc_disconnect(tport->ref);
1619                        tipc_reject_msg(buf, TIPC_CONN_SHUTDOWN);
1620                } else {
1621                        tipc_shutdown(tport->ref);
1622                }
1623
1624                sock->state = SS_DISCONNECTING;
1625
1626                /* fall through */
1627
1628        case SS_DISCONNECTING:
1629
1630                /* Discard any unreceived messages; wake up sleeping tasks */
1631
1632                discard_rx_queue(sk);
1633                if (waitqueue_active(sk->sk_sleep))
1634                        wake_up_interruptible(sk->sk_sleep);
1635                res = 0;
1636                break;
1637
1638        default:
1639                res = -ENOTCONN;
1640        }
1641
1642        release_sock(sk);
1643        return res;
1644}
1645
1646/**
1647 * setsockopt - set socket option
1648 * @sock: socket structure
1649 * @lvl: option level
1650 * @opt: option identifier
1651 * @ov: pointer to new option value
1652 * @ol: length of option value
1653 *
1654 * For stream sockets only, accepts and ignores all IPPROTO_TCP options
1655 * (to ease compatibility).
1656 *
1657 * Returns 0 on success, errno otherwise
1658 */
1659
1660static int setsockopt(struct socket *sock,
1661                      int lvl, int opt, char __user *ov, int ol)
1662{
1663        struct sock *sk = sock->sk;
1664        struct tipc_port *tport = tipc_sk_port(sk);
1665        u32 value;
1666        int res;
1667
1668        if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1669                return 0;
1670        if (lvl != SOL_TIPC)
1671                return -ENOPROTOOPT;
1672        if (ol < sizeof(value))
1673                return -EINVAL;
1674        if ((res = get_user(value, (u32 __user *)ov)))
1675                return res;
1676
1677        lock_sock(sk);
1678
1679        switch (opt) {
1680        case TIPC_IMPORTANCE:
1681                res = tipc_set_portimportance(tport->ref, value);
1682                break;
1683        case TIPC_SRC_DROPPABLE:
1684                if (sock->type != SOCK_STREAM)
1685                        res = tipc_set_portunreliable(tport->ref, value);
1686                else
1687                        res = -ENOPROTOOPT;
1688                break;
1689        case TIPC_DEST_DROPPABLE:
1690                res = tipc_set_portunreturnable(tport->ref, value);
1691                break;
1692        case TIPC_CONN_TIMEOUT:
1693                sk->sk_rcvtimeo = msecs_to_jiffies(value);
1694                /* no need to set "res", since already 0 at this point */
1695                break;
1696        default:
1697                res = -EINVAL;
1698        }
1699
1700        release_sock(sk);
1701
1702        return res;
1703}
1704
1705/**
1706 * getsockopt - get socket option
1707 * @sock: socket structure
1708 * @lvl: option level
1709 * @opt: option identifier
1710 * @ov: receptacle for option value
1711 * @ol: receptacle for length of option value
1712 *
1713 * For stream sockets only, returns 0 length result for all IPPROTO_TCP options
1714 * (to ease compatibility).
1715 *
1716 * Returns 0 on success, errno otherwise
1717 */
1718
1719static int getsockopt(struct socket *sock,
1720                      int lvl, int opt, char __user *ov, int __user *ol)
1721{
1722        struct sock *sk = sock->sk;
1723        struct tipc_port *tport = tipc_sk_port(sk);
1724        int len;
1725        u32 value;
1726        int res;
1727
1728        if ((lvl == IPPROTO_TCP) && (sock->type == SOCK_STREAM))
1729                return put_user(0, ol);
1730        if (lvl != SOL_TIPC)
1731                return -ENOPROTOOPT;
1732        if ((res = get_user(len, ol)))
1733                return res;
1734
1735        lock_sock(sk);
1736
1737        switch (opt) {
1738        case TIPC_IMPORTANCE:
1739                res = tipc_portimportance(tport->ref, &value);
1740                break;
1741        case TIPC_SRC_DROPPABLE:
1742                res = tipc_portunreliable(tport->ref, &value);
1743                break;
1744        case TIPC_DEST_DROPPABLE:
1745                res = tipc_portunreturnable(tport->ref, &value);
1746                break;
1747        case TIPC_CONN_TIMEOUT:
1748                value = jiffies_to_msecs(sk->sk_rcvtimeo);
1749                /* no need to set "res", since already 0 at this point */
1750                break;
1751        default:
1752                res = -EINVAL;
1753        }
1754
1755        release_sock(sk);
1756
1757        if (res) {
1758                /* "get" failed */
1759        }
1760        else if (len < sizeof(value)) {
1761                res = -EINVAL;
1762        }
1763        else if (copy_to_user(ov, &value, sizeof(value))) {
1764                res = -EFAULT;
1765        }
1766        else {
1767                res = put_user(sizeof(value), ol);
1768        }
1769
1770        return res;
1771}
1772
1773/**
1774 * Protocol switches for the various types of TIPC sockets
1775 */
1776
1777static const struct proto_ops msg_ops = {
1778        .owner          = THIS_MODULE,
1779        .family         = AF_TIPC,
1780        .release        = release,
1781        .bind           = bind,
1782        .connect        = connect,
1783        .socketpair     = sock_no_socketpair,
1784        .accept         = accept,
1785        .getname        = get_name,
1786        .poll           = poll,
1787        .ioctl          = sock_no_ioctl,
1788        .listen         = listen,
1789        .shutdown       = shutdown,
1790        .setsockopt     = setsockopt,
1791        .getsockopt     = getsockopt,
1792        .sendmsg        = send_msg,
1793        .recvmsg        = recv_msg,
1794        .mmap           = sock_no_mmap,
1795        .sendpage       = sock_no_sendpage
1796};
1797
1798static const struct proto_ops packet_ops = {
1799        .owner          = THIS_MODULE,
1800        .family         = AF_TIPC,
1801        .release        = release,
1802        .bind           = bind,
1803        .connect        = connect,
1804        .socketpair     = sock_no_socketpair,
1805        .accept         = accept,
1806        .getname        = get_name,
1807        .poll           = poll,
1808        .ioctl          = sock_no_ioctl,
1809        .listen         = listen,
1810        .shutdown       = shutdown,
1811        .setsockopt     = setsockopt,
1812        .getsockopt     = getsockopt,
1813        .sendmsg        = send_packet,
1814        .recvmsg        = recv_msg,
1815        .mmap           = sock_no_mmap,
1816        .sendpage       = sock_no_sendpage
1817};
1818
1819static const struct proto_ops stream_ops = {
1820        .owner          = THIS_MODULE,
1821        .family         = AF_TIPC,
1822        .release        = release,
1823        .bind           = bind,
1824        .connect        = connect,
1825        .socketpair     = sock_no_socketpair,
1826        .accept         = accept,
1827        .getname        = get_name,
1828        .poll           = poll,
1829        .ioctl          = sock_no_ioctl,
1830        .listen         = listen,
1831        .shutdown       = shutdown,
1832        .setsockopt     = setsockopt,
1833        .getsockopt     = getsockopt,
1834        .sendmsg        = send_stream,
1835        .recvmsg        = recv_stream,
1836        .mmap           = sock_no_mmap,
1837        .sendpage       = sock_no_sendpage
1838};
1839
1840static const struct net_proto_family tipc_family_ops = {
1841        .owner          = THIS_MODULE,
1842        .family         = AF_TIPC,
1843        .create         = tipc_create
1844};
1845
1846static struct proto tipc_proto = {
1847        .name           = "TIPC",
1848        .owner          = THIS_MODULE,
1849        .obj_size       = sizeof(struct tipc_sock)
1850};
1851
1852/**
1853 * tipc_socket_init - initialize TIPC socket interface
1854 *
1855 * Returns 0 on success, errno otherwise
1856 */
1857int tipc_socket_init(void)
1858{
1859        int res;
1860
1861        res = proto_register(&tipc_proto, 1);
1862        if (res) {
1863                err("Failed to register TIPC protocol type\n");
1864                goto out;
1865        }
1866
1867        res = sock_register(&tipc_family_ops);
1868        if (res) {
1869                err("Failed to register TIPC socket type\n");
1870                proto_unregister(&tipc_proto);
1871                goto out;
1872        }
1873
1874        sockets_enabled = 1;
1875 out:
1876        return res;
1877}
1878
1879/**
1880 * tipc_socket_stop - stop TIPC socket interface
1881 */
1882
1883void tipc_socket_stop(void)
1884{
1885        if (!sockets_enabled)
1886                return;
1887
1888        sockets_enabled = 0;
1889        sock_unregister(tipc_family_ops.family);
1890        proto_unregister(&tipc_proto);
1891}
1892
1893
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