net/llc/af_llc.c

   1 /*
   2  * af_llc.c - LLC User Interface SAPs
   3  * Description:
   4  *   Functions in this module are implementation of socket based llc
   5  *   communications for the Linux operating system. Support of llc class
   6  *   one and class two is provided via SOCK_DGRAM and SOCK_STREAM
   7  *   respectively.
   8  *
   9  *   An llc2 connection is (mac + sap), only one llc2 sap connection
  10  *   is allowed per mac. Though one sap may have multiple mac + sap
  11  *   connections.
  12  *
  13  * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
  14  *               2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  15  *
  16  * This program can be redistributed or modified under the terms of the
  17  * GNU General Public License as published by the Free Software Foundation.
  18  * This program is distributed without any warranty or implied warranty
  19  * of merchantability or fitness for a particular purpose.
  20  *
  21  * See the GNU General Public License for more details.
  22  */
  23 #include <linux/config.h>
  24 #include <linux/compiler.h>
  25 #include <linux/kernel.h>
  26 #include <linux/module.h>
  27 #include <linux/rtnetlink.h>
  28 #include <linux/init.h>
  29 #include <net/llc.h>
  30 #include <net/llc_sap.h>
  31 #include <net/llc_pdu.h>
  32 #include <net/llc_conn.h>
  33 #include <net/tcp_states.h>
  34
  35 /* remember: uninitialized global data is zeroed because its in .bss */
  36 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
  37 static u16 llc_ui_sap_link_no_max[256];
  38 static struct sockaddr_llc llc_ui_addrnull;
  39 static struct proto_ops llc_ui_ops;
  40
  41 static int llc_ui_wait_for_conn(struct sock *sk, long timeout);
  42 static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
  43 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
  44
  45 #if 0
  46 #define dprintk(args...) printk(KERN_DEBUG args)
  47 #else
  48 #define dprintk(args...)
  49 #endif
  50
  51 /**
  52  *      llc_ui_next_link_no - return the next unused link number for a sap
  53  *      @sap: Address of sap to get link number from.
  54  *
  55  *      Return the next unused link number for a given sap.
  56  */
  57 static __inline__ u16 llc_ui_next_link_no(int sap)
  58 {
  59         return llc_ui_sap_link_no_max[sap]++;
  60 }
  61
  62 /**
  63  *      llc_proto_type - return eth protocol for ARP header type
  64  *      @arphrd: ARP header type.
  65  *
  66  *      Given an ARP header type return the corresponding ethernet protocol.
  67  */
  68 static __inline__ u16 llc_proto_type(u16 arphrd)
  69 {
  70         return arphrd == ARPHRD_IEEE802_TR ?
  71                          htons(ETH_P_TR_802_2) : htons(ETH_P_802_2);
  72 }
  73
  74 /**
  75  *      llc_ui_addr_null - determines if a address structure is null
  76  *      @addr: Address to test if null.
  77  */
  78 static __inline__ u8 llc_ui_addr_null(struct sockaddr_llc *addr)
  79 {
  80         return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
  81 }
  82
  83 /**
  84  *      llc_ui_header_len - return length of llc header based on operation
  85  *      @sk: Socket which contains a valid llc socket type.
  86  *      @addr: Complete sockaddr_llc structure received from the user.
  87  *
  88  *      Provide the length of the llc header depending on what kind of
  89  *      operation the user would like to perform and the type of socket.
  90  *      Returns the correct llc header length.
  91  */
  92 static __inline__ u8 llc_ui_header_len(struct sock *sk,
  93                                        struct sockaddr_llc *addr)
  94 {
  95         u8 rc = LLC_PDU_LEN_U;
  96
  97         if (addr->sllc_test || addr->sllc_xid)
  98                 rc = LLC_PDU_LEN_U;
  99         else if (sk->sk_type == SOCK_STREAM)
 100                 rc = LLC_PDU_LEN_I;
 101         return rc;
 102 }
 103
 104 /**
 105  *      llc_ui_send_data - send data via reliable llc2 connection
 106  *      @sk: Connection the socket is using.
 107  *      @skb: Data the user wishes to send.
 108  *      @addr: Source and destination fields provided by the user.
 109  *      @noblock: can we block waiting for data?
 110  *
 111  *      Send data via reliable llc2 connection.
 112  *      Returns 0 upon success, non-zero if action did not succeed.
 113  */
 114 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 115 {
 116         struct llc_sock* llc = llc_sk(sk);
 117         int rc = 0;
 118
 119         if (unlikely(llc_data_accept_state(llc->state) ||
 120                      llc->remote_busy_flag ||
 121                      llc->p_flag)) {
 122                 long timeout = sock_sndtimeo(sk, noblock);
 123
 124                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 125         }
 126         if (unlikely(!rc))
 127                 rc = llc_build_and_send_pkt(sk, skb);
 128         return rc;
 129 }
 130
 131 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 132 {
 133         sk->sk_type     = sock->type;
 134         sk->sk_sleep    = &sock->wait;
 135         sk->sk_socket   = sock;
 136         sock->sk        = sk;
 137         sock->ops       = &llc_ui_ops;
 138 }
 139
 140 static struct proto llc_proto = {
 141         .name     = "DDP",
 142         .owner    = THIS_MODULE,
 143         .obj_size = sizeof(struct llc_sock),
 144 };
 145
 146 /**
 147  *      llc_ui_create - alloc and init a new llc_ui socket
 148  *      @sock: Socket to initialize and attach allocated sk to.
 149  *      @protocol: Unused.
 150  *
 151  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 152  *      socket type we have available.
 153  *      Returns 0 upon success, negative upon failure.
 154  */
 155 static int llc_ui_create(struct socket *sock, int protocol)
 156 {
 157         struct sock *sk;
 158         int rc = -ESOCKTNOSUPPORT;
 159
 160         if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
 161                 rc = -ENOMEM;
 162                 sk = llc_sk_alloc(PF_LLC, GFP_KERNEL, &llc_proto);
 163                 if (sk) {
 164                         rc = 0;
 165                         llc_ui_sk_init(sock, sk);
 166                 }
 167         }
 168         return rc;
 169 }
 170
 171 /**
 172  *      llc_ui_release - shutdown socket
 173  *      @sock: Socket to release.
 174  *
 175  *      Shutdown and deallocate an existing socket.
 176  */
 177 static int llc_ui_release(struct socket *sock)
 178 {
 179         struct sock *sk = sock->sk;
 180         struct llc_sock *llc;
 181
 182         if (unlikely(sk == NULL))
 183                 goto out;
 184         sock_hold(sk);
 185         lock_sock(sk);
 186         llc = llc_sk(sk);
 187         dprintk("%s: closing local(%02X) remote(%02X)\n", __FUNCTION__,
 188                 llc->laddr.lsap, llc->daddr.lsap);
 189         if (!llc_send_disc(sk))
 190                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 191         if (!sock_flag(sk, SOCK_ZAPPED))
 192                 llc_sap_remove_socket(llc->sap, sk);
 193         release_sock(sk);
 194         if (llc->dev)
 195                 dev_put(llc->dev);
 196         sock_put(sk);
 197         llc_sk_free(sk);
 198 out:
 199         return 0;
 200 }
 201
 202 /**
 203  *      llc_ui_autoport - provide dynamically allocate SAP number
 204  *
 205  *      Provide the caller with a dynamically allocated SAP number according
 206  *      to the rules that are set in this function. Returns: 0, upon failure,
 207  *      SAP number otherwise.
 208  */
 209 static int llc_ui_autoport(void)
 210 {
 211         struct llc_sap *sap;
 212         int i, tries = 0;
 213
 214         while (tries < LLC_SAP_DYN_TRIES) {
 215                 for (i = llc_ui_sap_last_autoport;
 216                      i < LLC_SAP_DYN_STOP; i += 2) {
 217                         sap = llc_sap_find(i);
 218                         if (!sap) {
 219                                 llc_ui_sap_last_autoport = i + 2;
 220                                 goto out;
 221                         }
 222                         llc_sap_put(sap);
 223                 }
 224                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 225                 tries++;
 226         }
 227         i = 0;
 228 out:
 229         return i;
 230 }
 231
 232 /**
 233  *      llc_ui_autobind - automatically bind a socket to a sap
 234  *      @sock: socket to bind
 235  *      @addr: address to connect to
 236  *
 237  *      Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
 238  *      specifically used llc_ui_bind to bind to an specific address/sap
 239  *
 240  *      Returns: 0 upon success, negative otherwise.
 241  */
 242 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 243 {
 244         struct sock *sk = sock->sk;
 245         struct llc_sock *llc = llc_sk(sk);
 246         struct llc_sap *sap;
 247         int rc = -EINVAL;
 248
 249         if (!sock_flag(sk, SOCK_ZAPPED))
 250                 goto out;
 251         rc = -ENODEV;
 252         llc->dev = dev_getfirstbyhwtype(addr->sllc_arphrd);
 253         if (!llc->dev)
 254                 goto out;
 255         rc = -EUSERS;
 256         llc->laddr.lsap = llc_ui_autoport();
 257         if (!llc->laddr.lsap)
 258                 goto out;
 259         rc = -EBUSY; /* some other network layer is using the sap */
 260         sap = llc_sap_open(llc->laddr.lsap, NULL);
 261         if (!sap)
 262                 goto out;
 263         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 264         memcpy(&llc->addr, addr, sizeof(llc->addr));
 265         /* assign new connection to its SAP */
 266         llc_sap_add_socket(sap, sk);
 267         sock_reset_flag(sk, SOCK_ZAPPED);
 268         rc = 0;
 269 out:
 270         return rc;
 271 }
 272
 273 /**
 274  *      llc_ui_bind - bind a socket to a specific address.
 275  *      @sock: Socket to bind an address to.
 276  *      @uaddr: Address the user wants the socket bound to.
 277  *      @addrlen: Length of the uaddr structure.
 278  *
 279  *      Bind a socket to a specific address. For llc a user is able to bind to
 280  *      a specific sap only or mac + sap.
 281  *      If the user desires to bind to a specific mac + sap, it is possible to
 282  *      have multiple sap connections via multiple macs.
 283  *      Bind and autobind for that matter must enforce the correct sap usage
 284  *      otherwise all hell will break loose.
 285  *      Returns: 0 upon success, negative otherwise.
 286  */
 287 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 288 {
 289         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 290         struct sock *sk = sock->sk;
 291         struct llc_sock *llc = llc_sk(sk);
 292         struct llc_sap *sap;
 293         int rc = -EINVAL;
 294
 295         dprintk("%s: binding %02X\n", __FUNCTION__, addr->sllc_sap);
 296         if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
 297                 goto out;
 298         rc = -EAFNOSUPPORT;
 299         if (unlikely(addr->sllc_family != AF_LLC))
 300                 goto out;
 301         rc = -ENODEV;
 302         rtnl_lock();
 303         llc->dev = dev_getbyhwaddr(addr->sllc_arphrd, addr->sllc_mac);
 304         rtnl_unlock();
 305         if (!llc->dev)
 306                 goto out;
 307         if (!addr->sllc_sap) {
 308                 rc = -EUSERS;
 309                 addr->sllc_sap = llc_ui_autoport();
 310                 if (!addr->sllc_sap)
 311                         goto out;
 312         }
 313         sap = llc_sap_find(addr->sllc_sap);
 314         if (!sap) {
 315                 sap = llc_sap_open(addr->sllc_sap, NULL);
 316                 rc = -EBUSY; /* some other network layer is using the sap */
 317                 if (!sap)
 318                         goto out;
 319                 llc_sap_hold(sap);
 320         } else {
 321                 struct llc_addr laddr, daddr;
 322                 struct sock *ask;
 323
 324                 memset(&laddr, 0, sizeof(laddr));
 325                 memset(&daddr, 0, sizeof(daddr));
 326                 /*
 327                  * FIXME: check if the the address is multicast,
 328                  *        only SOCK_DGRAM can do this.
 329                  */
 330                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 331                 laddr.lsap = addr->sllc_sap;
 332                 rc = -EADDRINUSE; /* mac + sap clash. */
 333                 ask = llc_lookup_established(sap, &daddr, &laddr);
 334                 if (ask) {
 335                         sock_put(ask);
 336                         goto out_put;
 337                 }
 338         }
 339         llc->laddr.lsap = addr->sllc_sap;
 340         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 341         memcpy(&llc->addr, addr, sizeof(llc->addr));
 342         /* assign new connection to its SAP */
 343         llc_sap_add_socket(sap, sk);
 344         sock_reset_flag(sk, SOCK_ZAPPED);
 345         rc = 0;
 346 out_put:
 347         llc_sap_put(sap);
 348 out:
 349         return rc;
 350 }
 351
 352 /**
 353  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 354  *      @sock: Socket to shutdown.
 355  *      @how: What part of the socket to shutdown.
 356  *
 357  *      Shutdown a connected llc2 socket. Currently this function only supports
 358  *      shutting down both sends and receives (2), we could probably make this
 359  *      function such that a user can shutdown only half the connection but not
 360  *      right now.
 361  *      Returns: 0 upon success, negative otherwise.
 362  */
 363 static int llc_ui_shutdown(struct socket *sock, int how)
 364 {
 365         struct sock *sk = sock->sk;
 366         int rc = -ENOTCONN;
 367
 368         lock_sock(sk);
 369         if (unlikely(sk->sk_state != TCP_ESTABLISHED))
 370                 goto out;
 371         rc = -EINVAL;
 372         if (how != 2)
 373                 goto out;
 374         rc = llc_send_disc(sk);
 375         if (!rc)
 376                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 377         /* Wake up anyone sleeping in poll */
 378         sk->sk_state_change(sk);
 379 out:
 380         release_sock(sk);
 381         return rc;
 382 }
 383
 384 /**
 385  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 386  *      @sock: Socket which will be connected to the remote destination.
 387  *      @uaddr: Remote and possibly the local address of the new connection.
 388  *      @addrlen: Size of uaddr structure.
 389  *      @flags: Operational flags specified by the user.
 390  *
 391  *      Connect to a remote llc2 mac + sap. The caller must specify the
 392  *      destination mac and address to connect to. If the user hasn't previously
 393  *      called bind(2) with a smac the address of the first interface of the
 394  *      specified arp type will be used.
 395  *      This function will autobind if user did not previously call bind.
 396  *      Returns: 0 upon success, negative otherwise.
 397  */
 398 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 399                           int addrlen, int flags)
 400 {
 401         struct sock *sk = sock->sk;
 402         struct llc_sock *llc = llc_sk(sk);
 403         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 404         int rc = -EINVAL;
 405
 406         lock_sock(sk);
 407         if (unlikely(addrlen != sizeof(*addr)))
 408                 goto out;
 409         rc = -EAFNOSUPPORT;
 410         if (unlikely(addr->sllc_family != AF_LLC))
 411                 goto out;
 412         if (unlikely(sk->sk_type != SOCK_STREAM))
 413                 goto out;
 414         rc = -EALREADY;
 415         if (unlikely(sock->state == SS_CONNECTING))
 416                 goto out;
 417         /* bind connection to sap if user hasn't done it. */
 418         if (sock_flag(sk, SOCK_ZAPPED)) {
 419                 /* bind to sap with null dev, exclusive */
 420                 rc = llc_ui_autobind(sock, addr);
 421                 if (rc)
 422                         goto out;
 423         }
 424         llc->daddr.lsap = addr->sllc_sap;
 425         memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 426         sock->state = SS_CONNECTING;
 427         sk->sk_state   = TCP_SYN_SENT;
 428         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 429         rc = llc_establish_connection(sk, llc->dev->dev_addr,
 430                                       addr->sllc_mac, addr->sllc_sap);
 431         if (rc) {
 432                 dprintk("%s: llc_ui_send_conn failed :-(\n", __FUNCTION__);
 433                 sock->state  = SS_UNCONNECTED;
 434                 sk->sk_state = TCP_CLOSE;
 435                 goto out;
 436         }
 437
 438         if (sk->sk_state == TCP_SYN_SENT) {
 439                 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 440
 441                 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
 442                         goto out;
 443
 444                 rc = sock_intr_errno(timeo);
 445                 if (signal_pending(current))
 446                         goto out;
 447         }
 448
 449         if (sk->sk_state == TCP_CLOSE)
 450                 goto sock_error;
 451
 452         sock->state = SS_CONNECTED;
 453         rc = 0;
 454 out:
 455         release_sock(sk);
 456         return rc;
 457 sock_error:
 458         rc = sock_error(sk) ? : -ECONNABORTED;
 459         sock->state = SS_UNCONNECTED;
 460         goto out;
 461 }
 462
 463 /**
 464  *      llc_ui_listen - allow a normal socket to accept incoming connections
 465  *      @sock: Socket to allow incoming connections on.
 466  *      @backlog: Number of connections to queue.
 467  *
 468  *      Allow a normal socket to accept incoming connections.
 469  *      Returns 0 upon success, negative otherwise.
 470  */
 471 static int llc_ui_listen(struct socket *sock, int backlog)
 472 {
 473         struct sock *sk = sock->sk;
 474         int rc = -EINVAL;
 475
 476         lock_sock(sk);
 477         if (unlikely(sock->state != SS_UNCONNECTED))
 478                 goto out;
 479         rc = -EOPNOTSUPP;
 480         if (unlikely(sk->sk_type != SOCK_STREAM))
 481                 goto out;
 482         rc = -EAGAIN;
 483         if (sock_flag(sk, SOCK_ZAPPED))
 484                 goto out;
 485         rc = 0;
 486         if (!(unsigned)backlog) /* BSDism */
 487                 backlog = 1;
 488         sk->sk_max_ack_backlog = backlog;
 489         if (sk->sk_state != TCP_LISTEN) {
 490                 sk->sk_ack_backlog = 0;
 491                 sk->sk_state       = TCP_LISTEN;
 492         }
 493         sk->sk_socket->flags |= __SO_ACCEPTCON;
 494 out:
 495         release_sock(sk);
 496         return rc;
 497 }
 498
 499 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
 500 {
 501         DEFINE_WAIT(wait);
 502         int rc = 0;
 503
 504         while (1) {
 505                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 506                 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE))
 507                         break;
 508                 rc = -ERESTARTSYS;
 509                 if (signal_pending(current))
 510                         break;
 511                 rc = -EAGAIN;
 512                 if (!timeout)
 513                         break;
 514                 rc = 0;
 515         }
 516         finish_wait(sk->sk_sleep, &wait);
 517         return rc;
 518 }
 519
 520 static int llc_ui_wait_for_conn(struct sock *sk, long timeout)
 521 {
 522         DEFINE_WAIT(wait);
 523
 524         while (1) {
 525                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 526                 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT))
 527                         break;
 528                 if (signal_pending(current) || !timeout)
 529                         break;
 530         }
 531         finish_wait(sk->sk_sleep, &wait);
 532         return timeout;
 533 }
 534
 535 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
 536 {
 537         DEFINE_WAIT(wait);
 538         struct llc_sock *llc = llc_sk(sk);
 539         int rc;
 540
 541         while (1) {
 542                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 543                 rc = 0;
 544                 if (sk_wait_event(sk, &timeout,
 545                                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
 546                                   (!llc_data_accept_state(llc->state) &&
 547                                    !llc->remote_busy_flag &&
 548                                    !llc->p_flag)))
 549                         break;
 550                 rc = -ERESTARTSYS;
 551                 if (signal_pending(current))
 552                         break;
 553                 rc = -EAGAIN;
 554                 if (!timeout)
 555                         break;
 556         }
 557         finish_wait(sk->sk_sleep, &wait);
 558         return rc;
 559 }
 560
 561 static int llc_wait_data(struct sock *sk, long timeo)
 562 {
 563         int rc;
 564
 565         while (1) {
 566                 /*
 567                  * POSIX 1003.1g mandates this order.
 568                  */
 569                 if (sk->sk_err) {
 570                         rc = sock_error(sk);
 571                         break;
 572                 }
 573                 rc = 0;
 574                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 575                         break;
 576                 rc = -EAGAIN;
 577                 if (!timeo)
 578                         break;
 579                 rc = sock_intr_errno(timeo);
 580                 if (signal_pending(current))
 581                         break;
 582                 rc = 0;
 583                 if (sk_wait_data(sk, &timeo))
 584                         break;
 585         }
 586         return rc;
 587 }
 588
 589 /**
 590  *      llc_ui_accept - accept a new incoming connection.
 591  *      @sock: Socket which connections arrive on.
 592  *      @newsock: Socket to move incoming connection to.
 593  *      @flags: User specified operational flags.
 594  *
 595  *      Accept a new incoming connection.
 596  *      Returns 0 upon success, negative otherwise.
 597  */
 598 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 599 {
 600         struct sock *sk = sock->sk, *newsk;
 601         struct llc_sock *llc, *newllc;
 602         struct sk_buff *skb;
 603         int rc = -EOPNOTSUPP;
 604
 605         dprintk("%s: accepting on %02X\n", __FUNCTION__,
 606                 llc_sk(sk)->laddr.lsap);
 607         lock_sock(sk);
 608         if (unlikely(sk->sk_type != SOCK_STREAM))
 609                 goto out;
 610         rc = -EINVAL;
 611         if (unlikely(sock->state != SS_UNCONNECTED ||
 612                      sk->sk_state != TCP_LISTEN))
 613                 goto out;
 614         /* wait for a connection to arrive. */
 615         if (skb_queue_empty(&sk->sk_receive_queue)) {
 616                 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
 617                 if (rc)
 618                         goto out;
 619         }
 620         dprintk("%s: got a new connection on %02X\n", __FUNCTION__,
 621                 llc_sk(sk)->laddr.lsap);
 622         skb = skb_dequeue(&sk->sk_receive_queue);
 623         rc = -EINVAL;
 624         if (!skb->sk)
 625                 goto frees;
 626         rc = 0;
 627         newsk = skb->sk;
 628         /* attach connection to a new socket. */
 629         llc_ui_sk_init(newsock, newsk);
 630         sock_reset_flag(newsk, SOCK_ZAPPED);
 631         newsk->sk_state         = TCP_ESTABLISHED;
 632         newsock->state          = SS_CONNECTED;
 633         llc                     = llc_sk(sk);
 634         newllc                  = llc_sk(newsk);
 635         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 636         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 637
 638         /* put original socket back into a clean listen state. */
 639         sk->sk_state = TCP_LISTEN;
 640         sk->sk_ack_backlog--;
 641         dprintk("%s: ok success on %02X, client on %02X\n", __FUNCTION__,
 642                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 643 frees:
 644         kfree_skb(skb);
 645 out:
 646         release_sock(sk);
 647         return rc;
 648 }
 649
 650 /**
 651  *      llc_ui_recvmsg - copy received data to the socket user.
 652  *      @sock: Socket to copy data from.
 653  *      @msg: Various user space related information.
 654  *      @len: Size of user buffer.
 655  *      @flags: User specified flags.
 656  *
 657  *      Copy received data to the socket user.
 658  *      Returns non-negative upon success, negative otherwise.
 659  */
 660 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 661                           struct msghdr *msg, size_t len, int flags)
 662 {
 663         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 664         const int nonblock = flags & MSG_DONTWAIT;
 665         struct sk_buff *skb = NULL;
 666         struct sock *sk = sock->sk;
 667         struct llc_sock *llc = llc_sk(sk);
 668         size_t copied = 0;
 669         u32 peek_seq = 0;
 670         u32 *seq;
 671         unsigned long used;
 672         int target;     /* Read at least this many bytes */
 673         long timeo;
 674
 675         lock_sock(sk);
 676         copied = -ENOTCONN;
 677         if (sk->sk_state == TCP_LISTEN)
 678                 goto out;
 679
 680         timeo = sock_rcvtimeo(sk, nonblock);
 681
 682         seq = &llc->copied_seq;
 683         if (flags & MSG_PEEK) {
 684                 peek_seq = llc->copied_seq;
 685                 seq = &peek_seq;
 686         }
 687
 688         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 689         copied = 0;
 690
 691         do {
 692                 u32 offset;
 693
 694                 /*
 695                  * We need to check signals first, to get correct SIGURG
 696                  * handling. FIXME: Need to check this doesn't impact 1003.1g
 697                  * and move it down to the bottom of the loop
 698                  */
 699                 if (signal_pending(current)) {
 700                         if (copied)
 701                                 break;
 702                         copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 703                         break;
 704                 }
 705
 706                 /* Next get a buffer. */
 707
 708                 skb = skb_peek(&sk->sk_receive_queue);
 709                 if (skb) {
 710                         offset = *seq;
 711                         goto found_ok_skb;
 712                 }
 713                 /* Well, if we have backlog, try to process it now yet. */
 714
 715                 if (copied >= target && !sk->sk_backlog.tail)
 716                         break;
 717
 718                 if (copied) {
 719                         if (sk->sk_err ||
 720                             sk->sk_state == TCP_CLOSE ||
 721                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 722                             !timeo ||
 723                             (flags & MSG_PEEK))
 724                                 break;
 725                 } else {
 726                         if (sock_flag(sk, SOCK_DONE))
 727                                 break;
 728
 729                         if (sk->sk_err) {
 730                                 copied = sock_error(sk);
 731                                 break;
 732                         }
 733                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 734                                 break;
 735
 736                         if (sk->sk_state == TCP_CLOSE) {
 737                                 if (!sock_flag(sk, SOCK_DONE)) {
 738                                         /*
 739                                          * This occurs when user tries to read
 740                                          * from never connected socket.
 741                                          */
 742                                         copied = -ENOTCONN;
 743                                         break;
 744                                 }
 745                                 break;
 746                         }
 747                         if (!timeo) {
 748                                 copied = -EAGAIN;
 749                                 break;
 750                         }
 751                 }
 752
 753                 if (copied >= target) { /* Do not sleep, just process backlog. */
 754                         release_sock(sk);
 755                         lock_sock(sk);
 756                 } else
 757                         sk_wait_data(sk, &timeo);
 758
 759                 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
 760                         if (net_ratelimit())
 761                                 printk(KERN_DEBUG "LLC(%s:%d): Application "
 762                                                   "bug, race in MSG_PEEK.\n",
 763                                        current->comm, current->pid);
 764                         peek_seq = llc->copied_seq;
 765                 }
 766                 continue;
 767         found_ok_skb:
 768                 /* Ok so how much can we use? */
 769                 used = skb->len - offset;
 770                 if (len < used)
 771                         used = len;
 772
 773                 if (!(flags & MSG_TRUNC)) {
 774                         int rc = skb_copy_datagram_iovec(skb, offset,
 775                                                          msg->msg_iov, used);
 776                         if (rc) {
 777                                 /* Exception. Bailout! */
 778                                 if (!copied)
 779                                         copied = -EFAULT;
 780                                 break;
 781                         }
 782                 }
 783
 784                 *seq += used;
 785                 copied += used;
 786                 len -= used;
 787
 788                 if (used + offset < skb->len)
 789                         continue;
 790
 791                 if (!(flags & MSG_PEEK)) {
 792                         sk_eat_skb(sk, skb);
 793                         *seq = 0;
 794                 }
 795         } while (len > 0);
 796
 797         /*
 798          * According to UNIX98, msg_name/msg_namelen are ignored
 799          * on connected socket. -ANK
 800          * But... af_llc still doesn't have separate sets of methods for
 801          * SOCK_DGRAM and SOCK_STREAM :-( So we have to do this test, will
 802          * eventually fix this tho :-) -acme
 803          */
 804         if (sk->sk_type == SOCK_DGRAM)
 805                 goto copy_uaddr;
 806 out:
 807         release_sock(sk);
 808         return copied;
 809 copy_uaddr:
 810         if (uaddr != NULL && skb != NULL) {
 811                 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 812                 msg->msg_namelen = sizeof(*uaddr);
 813         }
 814         goto out;
 815 }
 816
 817 /**
 818  *      llc_ui_sendmsg - Transmit data provided by the socket user.
 819  *      @sock: Socket to transmit data from.
 820  *      @msg: Various user related information.
 821  *      @len: Length of data to transmit.
 822  *
 823  *      Transmit data provided by the socket user.
 824  *      Returns non-negative upon success, negative otherwise.
 825  */
 826 static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock,
 827                           struct msghdr *msg, size_t len)
 828 {
 829         struct sock *sk = sock->sk;
 830         struct llc_sock *llc = llc_sk(sk);
 831         struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name;
 832         int flags = msg->msg_flags;
 833         int noblock = flags & MSG_DONTWAIT;
 834         struct sk_buff *skb;
 835         size_t size = 0;
 836         int rc = -EINVAL, copied = 0, hdrlen;
 837
 838         dprintk("%s: sending from %02X to %02X\n", __FUNCTION__,
 839                 llc->laddr.lsap, llc->daddr.lsap);
 840         lock_sock(sk);
 841         if (addr) {
 842                 if (msg->msg_namelen < sizeof(*addr))
 843                         goto release;
 844         } else {
 845                 if (llc_ui_addr_null(&llc->addr))
 846                         goto release;
 847                 addr = &llc->addr;
 848         }
 849         /* must bind connection to sap if user hasn't done it. */
 850         if (sock_flag(sk, SOCK_ZAPPED)) {
 851                 /* bind to sap with null dev, exclusive. */
 852                 rc = llc_ui_autobind(sock, addr);
 853                 if (rc)
 854                         goto release;
 855         }
 856         hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
 857         size = hdrlen + len;
 858         if (size > llc->dev->mtu)
 859                 size = llc->dev->mtu;
 860         copied = size - hdrlen;
 861         release_sock(sk);
 862         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 863         lock_sock(sk);
 864         if (!skb)
 865                 goto release;
 866         skb->dev      = llc->dev;
 867         skb->protocol = llc_proto_type(addr->sllc_arphrd);
 868         skb_reserve(skb, hdrlen);
 869         rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied);
 870         if (rc)
 871                 goto out;
 872         if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
 873                 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
 874                                           addr->sllc_sap);
 875                 goto out;
 876         }
 877         if (addr->sllc_test) {
 878                 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
 879                                             addr->sllc_sap);
 880                 goto out;
 881         }
 882         if (addr->sllc_xid) {
 883                 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
 884                                            addr->sllc_sap);
 885                 goto out;
 886         }
 887         rc = -ENOPROTOOPT;
 888         if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
 889                 goto out;
 890         rc = llc_ui_send_data(sk, skb, noblock);
 891 out:
 892         if (rc) {
 893                 kfree_skb(skb);
 894 release:
 895                 dprintk("%s: failed sending from %02X to %02X: %d\n",
 896                         __FUNCTION__, llc->laddr.lsap, llc->daddr.lsap, rc);
 897         }
 898         release_sock(sk);
 899         return rc ? : copied;
 900 }
 901
 902 /**
 903  *      llc_ui_getname - return the address info of a socket
 904  *      @sock: Socket to get address of.
 905  *      @uaddr: Address structure to return information.
 906  *      @uaddrlen: Length of address structure.
 907  *      @peer: Does user want local or remote address information.
 908  *
 909  *      Return the address information of a socket.
 910  */
 911 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
 912                           int *uaddrlen, int peer)
 913 {
 914         struct sockaddr_llc sllc;
 915         struct sock *sk = sock->sk;
 916         struct llc_sock *llc = llc_sk(sk);
 917         int rc = 0;
 918
 919         lock_sock(sk);
 920         if (sock_flag(sk, SOCK_ZAPPED))
 921                 goto out;
 922         *uaddrlen = sizeof(sllc);
 923         memset(uaddr, 0, *uaddrlen);
 924         if (peer) {
 925                 rc = -ENOTCONN;
 926                 if (sk->sk_state != TCP_ESTABLISHED)
 927                         goto out;
 928                 if(llc->dev)
 929                         sllc.sllc_arphrd = llc->dev->type;
 930                 sllc.sllc_sap = llc->daddr.lsap;
 931                 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
 932         } else {
 933                 rc = -EINVAL;
 934                 if (!llc->sap)
 935                         goto out;
 936                 sllc.sllc_sap = llc->sap->laddr.lsap;
 937
 938                 if (llc->dev) {
 939                         sllc.sllc_arphrd = llc->dev->type;
 940                         memcpy(&sllc.sllc_mac, &llc->dev->dev_addr,
 941                                IFHWADDRLEN);
 942                 }
 943         }
 944         rc = 0;
 945         sllc.sllc_family = AF_LLC;
 946         memcpy(uaddr, &sllc, sizeof(sllc));
 947 out:
 948         release_sock(sk);
 949         return rc;
 950 }
 951
 952 /**
 953  *      llc_ui_ioctl - io controls for PF_LLC
 954  *      @sock: Socket to get/set info
 955  *      @cmd: command
 956  *      @arg: optional argument for cmd
 957  *
 958  *      get/set info on llc sockets
 959  */
 960 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
 961                         unsigned long arg)
 962 {
 963         return dev_ioctl(cmd, (void __user *)arg);
 964 }
 965
 966 /**
 967  *      llc_ui_setsockopt - set various connection specific parameters.
 968  *      @sock: Socket to set options on.
 969  *      @level: Socket level user is requesting operations on.
 970  *      @optname: Operation name.
 971  *      @optval User provided operation data.
 972  *      @optlen: Length of optval.
 973  *
 974  *      Set various connection specific parameters.
 975  */
 976 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 977                              char __user *optval, int optlen)
 978 {
 979         struct sock *sk = sock->sk;
 980         struct llc_sock *llc = llc_sk(sk);
 981         int rc = -EINVAL, opt;
 982
 983         lock_sock(sk);
 984         if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
 985                 goto out;
 986         rc = get_user(opt, (int __user *)optval);
 987         if (rc)
 988                 goto out;
 989         rc = -EINVAL;
 990         switch (optname) {
 991         case LLC_OPT_RETRY:
 992                 if (opt > LLC_OPT_MAX_RETRY)
 993                         goto out;
 994                 llc->n2 = opt;
 995                 break;
 996         case LLC_OPT_SIZE:
 997                 if (opt > LLC_OPT_MAX_SIZE)
 998                         goto out;
 999                 llc->n1 = opt;
1000                 break;
1001         case LLC_OPT_ACK_TMR_EXP:
1002                 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1003                         goto out;
1004                 llc->ack_timer.expire = opt * HZ;
1005                 break;
1006         case LLC_OPT_P_TMR_EXP:
1007                 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1008                         goto out;
1009                 llc->pf_cycle_timer.expire = opt * HZ;
1010                 break;
1011         case LLC_OPT_REJ_TMR_EXP:
1012                 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1013                         goto out;
1014                 llc->rej_sent_timer.expire = opt * HZ;
1015                 break;
1016         case LLC_OPT_BUSY_TMR_EXP:
1017                 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1018                         goto out;
1019                 llc->busy_state_timer.expire = opt * HZ;
1020                 break;
1021         case LLC_OPT_TX_WIN:
1022                 if (opt > LLC_OPT_MAX_WIN)
1023                         goto out;
1024                 llc->k = opt;
1025                 break;
1026         case LLC_OPT_RX_WIN:
1027                 if (opt > LLC_OPT_MAX_WIN)
1028                         goto out;
1029                 llc->rw = opt;
1030                 break;
1031         default:
1032                 rc = -ENOPROTOOPT;
1033                 goto out;
1034         }
1035         rc = 0;
1036 out:
1037         release_sock(sk);
1038         return rc;
1039 }
1040
1041 /**
1042  *      llc_ui_getsockopt - get connection specific socket info
1043  *      @sock: Socket to get information from.
1044  *      @level: Socket level user is requesting operations on.
1045  *      @optname: Operation name.
1046  *      @optval: Variable to return operation data in.
1047  *      @optlen: Length of optval.
1048  *
1049  *      Get connection specific socket information.
1050  */
1051 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1052                              char __user *optval, int __user *optlen)
1053 {
1054         struct sock *sk = sock->sk;
1055         struct llc_sock *llc = llc_sk(sk);
1056         int val = 0, len = 0, rc = -EINVAL;
1057
1058         lock_sock(sk);
1059         if (unlikely(level != SOL_LLC))
1060                 goto out;
1061         rc = get_user(len, optlen);
1062         if (rc)
1063                 goto out;
1064         rc = -EINVAL;
1065         if (len != sizeof(int))
1066                 goto out;
1067         switch (optname) {
1068         case LLC_OPT_RETRY:
1069                 val = llc->n2;                                  break;
1070         case LLC_OPT_SIZE:
1071                 val = llc->n1;                                  break;
1072         case LLC_OPT_ACK_TMR_EXP:
1073                 val = llc->ack_timer.expire / HZ;               break;
1074         case LLC_OPT_P_TMR_EXP:
1075                 val = llc->pf_cycle_timer.expire / HZ;          break;
1076         case LLC_OPT_REJ_TMR_EXP:
1077                 val = llc->rej_sent_timer.expire / HZ;          break;
1078         case LLC_OPT_BUSY_TMR_EXP:
1079                 val = llc->busy_state_timer.expire / HZ;        break;
1080         case LLC_OPT_TX_WIN:
1081                 val = llc->k;                           break;
1082         case LLC_OPT_RX_WIN:
1083                 val = llc->rw;                          break;
1084         default:
1085                 rc = -ENOPROTOOPT;
1086                 goto out;
1087         }
1088         rc = 0;
1089         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1090                 rc = -EFAULT;
1091 out:
1092         release_sock(sk);
1093         return rc;
1094 }
1095
1096 static struct net_proto_family llc_ui_family_ops = {
1097         .family = PF_LLC,
1098         .create = llc_ui_create,
1099         .owner  = THIS_MODULE,
1100 };
1101
1102 static struct proto_ops llc_ui_ops = {
1103         .family      = PF_LLC,
1104         .owner       = THIS_MODULE,
1105         .release     = llc_ui_release,
1106         .bind        = llc_ui_bind,
1107         .connect     = llc_ui_connect,
1108         .socketpair  = sock_no_socketpair,
1109         .accept      = llc_ui_accept,
1110         .getname     = llc_ui_getname,
1111         .poll        = datagram_poll,
1112         .ioctl       = llc_ui_ioctl,
1113         .listen      = llc_ui_listen,
1114         .shutdown    = llc_ui_shutdown,
1115         .setsockopt  = llc_ui_setsockopt,
1116         .getsockopt  = llc_ui_getsockopt,
1117         .sendmsg     = llc_ui_sendmsg,
1118         .recvmsg     = llc_ui_recvmsg,
1119         .mmap        = sock_no_mmap,
1120         .sendpage    = sock_no_sendpage,
1121 };
1122
1123 static char llc_proc_err_msg[] __initdata =
1124         KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1125 static char llc_sysctl_err_msg[] __initdata =
1126         KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1127 static char llc_sock_err_msg[] __initdata =
1128         KERN_CRIT "LLC: Unable to register the network family\n";
1129
1130 static int __init llc2_init(void)
1131 {
1132         int rc = proto_register(&llc_proto, 0);
1133
1134         if (rc != 0)
1135                 goto out;
1136
1137         llc_build_offset_table();
1138         llc_station_init();
1139         llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1140         rc = llc_proc_init();
1141         if (rc != 0) {
1142                 printk(llc_proc_err_msg);
1143                 goto out_unregister_llc_proto;
1144         }
1145         rc = llc_sysctl_init();
1146         if (rc) {
1147                 printk(llc_sysctl_err_msg);
1148                 goto out_proc;
1149         }
1150         rc = sock_register(&llc_ui_family_ops);
1151         if (rc) {
1152                 printk(llc_sock_err_msg);
1153                 goto out_sysctl;
1154         }
1155         llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1156         llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1157 out:
1158         return rc;
1159 out_sysctl:
1160         llc_sysctl_exit();
1161 out_proc:
1162         llc_proc_exit();
1163 out_unregister_llc_proto:
1164         proto_unregister(&llc_proto);
1165         goto out;
1166 }
1167
1168 static void __exit llc2_exit(void)
1169 {
1170         llc_station_exit();
1171         llc_remove_pack(LLC_DEST_SAP);
1172         llc_remove_pack(LLC_DEST_CONN);
1173         sock_unregister(PF_LLC);
1174         llc_proc_exit();
1175         llc_sysctl_exit();
1176         proto_unregister(&llc_proto);
1177 }
1178
1179 module_init(llc2_init);
1180 module_exit(llc2_exit);
1181
1182 MODULE_LICENSE("GPL");
1183 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1184 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1185 MODULE_ALIAS_NETPROTO(PF_LLC);