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/compiler.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/rtnetlink.h>
  27 #include <linux/init.h>
  28 #include <net/llc.h>
  29 #include <net/llc_sap.h>
  30 #include <net/llc_pdu.h>
  31 #include <net/llc_conn.h>
  32 #include <net/tcp_states.h>
  33
  34 /* remember: uninitialized global data is zeroed because its in .bss */
  35 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
  36 static u16 llc_ui_sap_link_no_max[256];
  37 static struct sockaddr_llc llc_ui_addrnull;
  38 static const struct proto_ops llc_ui_ops;
  39
  40 static int llc_ui_wait_for_conn(struct sock *sk, long timeout);
  41 static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
  42 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
  43
  44 #if 0
  45 #define dprintk(args...) printk(KERN_DEBUG args)
  46 #else
  47 #define dprintk(args...)
  48 #endif
  49
  50 /**
  51  *      llc_ui_next_link_no - return the next unused link number for a sap
  52  *      @sap: Address of sap to get link number from.
  53  *
  54  *      Return the next unused link number for a given sap.
  55  */
  56 static inline u16 llc_ui_next_link_no(int sap)
  57 {
  58         return llc_ui_sap_link_no_max[sap]++;
  59 }
  60
  61 /**
  62  *      llc_proto_type - return eth protocol for ARP header type
  63  *      @arphrd: ARP header type.
  64  *
  65  *      Given an ARP header type return the corresponding ethernet protocol.
  66  */
  67 static inline __be16 llc_proto_type(u16 arphrd)
  68 {
  69         return arphrd == ARPHRD_IEEE802_TR ?
  70                          htons(ETH_P_TR_802_2) : htons(ETH_P_802_2);
  71 }
  72
  73 /**
  74  *      llc_ui_addr_null - determines if a address structure is null
  75  *      @addr: Address to test if null.
  76  */
  77 static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
  78 {
  79         return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
  80 }
  81
  82 /**
  83  *      llc_ui_header_len - return length of llc header based on operation
  84  *      @sk: Socket which contains a valid llc socket type.
  85  *      @addr: Complete sockaddr_llc structure received from the user.
  86  *
  87  *      Provide the length of the llc header depending on what kind of
  88  *      operation the user would like to perform and the type of socket.
  89  *      Returns the correct llc header length.
  90  */
  91 static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
  92 {
  93         u8 rc = LLC_PDU_LEN_U;
  94
  95         if (addr->sllc_test || addr->sllc_xid)
  96                 rc = LLC_PDU_LEN_U;
  97         else if (sk->sk_type == SOCK_STREAM)
  98                 rc = LLC_PDU_LEN_I;
  99         return rc;
 100 }
 101
 102 /**
 103  *      llc_ui_send_data - send data via reliable llc2 connection
 104  *      @sk: Connection the socket is using.
 105  *      @skb: Data the user wishes to send.
 106  *      @addr: Source and destination fields provided by the user.
 107  *      @noblock: can we block waiting for data?
 108  *
 109  *      Send data via reliable llc2 connection.
 110  *      Returns 0 upon success, non-zero if action did not succeed.
 111  */
 112 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 113 {
 114         struct llc_sock* llc = llc_sk(sk);
 115         int rc = 0;
 116
 117         if (unlikely(llc_data_accept_state(llc->state) ||
 118                      llc->remote_busy_flag ||
 119                      llc->p_flag)) {
 120                 long timeout = sock_sndtimeo(sk, noblock);
 121
 122                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 123         }
 124         if (unlikely(!rc))
 125                 rc = llc_build_and_send_pkt(sk, skb);
 126         return rc;
 127 }
 128
 129 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 130 {
 131         sock_graft(sk, sock);
 132         sk->sk_type     = sock->type;
 133         sock->ops       = &llc_ui_ops;
 134 }
 135
 136 static struct proto llc_proto = {
 137         .name     = "LLC",
 138         .owner    = THIS_MODULE,
 139         .obj_size = sizeof(struct llc_sock),
 140 };
 141
 142 /**
 143  *      llc_ui_create - alloc and init a new llc_ui socket
 144  *      @sock: Socket to initialize and attach allocated sk to.
 145  *      @protocol: Unused.
 146  *
 147  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 148  *      socket type we have available.
 149  *      Returns 0 upon success, negative upon failure.
 150  */
 151 static int llc_ui_create(struct net *net, struct socket *sock, int protocol)
 152 {
 153         struct sock *sk;
 154         int rc = -ESOCKTNOSUPPORT;
 155
 156         if (!capable(CAP_NET_RAW))
 157                 return -EPERM;
 158
 159         if (net != &init_net)
 160                 return -EAFNOSUPPORT;
 161
 162         if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
 163                 rc = -ENOMEM;
 164                 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto);
 165                 if (sk) {
 166                         rc = 0;
 167                         llc_ui_sk_init(sock, sk);
 168                 }
 169         }
 170         return rc;
 171 }
 172
 173 /**
 174  *      llc_ui_release - shutdown socket
 175  *      @sock: Socket to release.
 176  *
 177  *      Shutdown and deallocate an existing socket.
 178  */
 179 static int llc_ui_release(struct socket *sock)
 180 {
 181         struct sock *sk = sock->sk;
 182         struct llc_sock *llc;
 183
 184         if (unlikely(sk == NULL))
 185                 goto out;
 186         sock_hold(sk);
 187         lock_sock(sk);
 188         llc = llc_sk(sk);
 189         dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
 190                 llc->laddr.lsap, llc->daddr.lsap);
 191         if (!llc_send_disc(sk))
 192                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 193         if (!sock_flag(sk, SOCK_ZAPPED)) {
 194                 llc_sap_put(llc->sap);
 195                 llc_sap_remove_socket(llc->sap, sk);
 196         }
 197         release_sock(sk);
 198         if (llc->dev)
 199                 dev_put(llc->dev);
 200         sock_put(sk);
 201         llc_sk_free(sk);
 202 out:
 203         return 0;
 204 }
 205
 206 /**
 207  *      llc_ui_autoport - provide dynamically allocate SAP number
 208  *
 209  *      Provide the caller with a dynamically allocated SAP number according
 210  *      to the rules that are set in this function. Returns: 0, upon failure,
 211  *      SAP number otherwise.
 212  */
 213 static int llc_ui_autoport(void)
 214 {
 215         struct llc_sap *sap;
 216         int i, tries = 0;
 217
 218         while (tries < LLC_SAP_DYN_TRIES) {
 219                 for (i = llc_ui_sap_last_autoport;
 220                      i < LLC_SAP_DYN_STOP; i += 2) {
 221                         sap = llc_sap_find(i);
 222                         if (!sap) {
 223                                 llc_ui_sap_last_autoport = i + 2;
 224                                 goto out;
 225                         }
 226                         llc_sap_put(sap);
 227                 }
 228                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 229                 tries++;
 230         }
 231         i = 0;
 232 out:
 233         return i;
 234 }
 235
 236 /**
 237  *      llc_ui_autobind - automatically bind a socket to a sap
 238  *      @sock: socket to bind
 239  *      @addr: address to connect to
 240  *
 241  *      Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
 242  *      specifically used llc_ui_bind to bind to an specific address/sap
 243  *
 244  *      Returns: 0 upon success, negative otherwise.
 245  */
 246 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 247 {
 248         struct sock *sk = sock->sk;
 249         struct llc_sock *llc = llc_sk(sk);
 250         struct llc_sap *sap;
 251         int rc = -EINVAL;
 252
 253         if (!sock_flag(sk, SOCK_ZAPPED))
 254                 goto out;
 255         rc = -ENODEV;
 256         llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
 257         if (!llc->dev)
 258                 goto out;
 259         rc = -EUSERS;
 260         llc->laddr.lsap = llc_ui_autoport();
 261         if (!llc->laddr.lsap)
 262                 goto out;
 263         rc = -EBUSY; /* some other network layer is using the sap */
 264         sap = llc_sap_open(llc->laddr.lsap, NULL);
 265         if (!sap)
 266                 goto out;
 267         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 268         memcpy(&llc->addr, addr, sizeof(llc->addr));
 269         /* assign new connection to its SAP */
 270         llc_sap_add_socket(sap, sk);
 271         sock_reset_flag(sk, SOCK_ZAPPED);
 272         rc = 0;
 273 out:
 274         return rc;
 275 }
 276
 277 /**
 278  *      llc_ui_bind - bind a socket to a specific address.
 279  *      @sock: Socket to bind an address to.
 280  *      @uaddr: Address the user wants the socket bound to.
 281  *      @addrlen: Length of the uaddr structure.
 282  *
 283  *      Bind a socket to a specific address. For llc a user is able to bind to
 284  *      a specific sap only or mac + sap.
 285  *      If the user desires to bind to a specific mac + sap, it is possible to
 286  *      have multiple sap connections via multiple macs.
 287  *      Bind and autobind for that matter must enforce the correct sap usage
 288  *      otherwise all hell will break loose.
 289  *      Returns: 0 upon success, negative otherwise.
 290  */
 291 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 292 {
 293         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 294         struct sock *sk = sock->sk;
 295         struct llc_sock *llc = llc_sk(sk);
 296         struct llc_sap *sap;
 297         int rc = -EINVAL;
 298
 299         dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
 300         if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
 301                 goto out;
 302         rc = -EAFNOSUPPORT;
 303         if (unlikely(addr->sllc_family != AF_LLC))
 304                 goto out;
 305         rc = -ENODEV;
 306         rtnl_lock();
 307         llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd, addr->sllc_mac);
 308         rtnl_unlock();
 309         if (!llc->dev)
 310                 goto out;
 311         if (!addr->sllc_sap) {
 312                 rc = -EUSERS;
 313                 addr->sllc_sap = llc_ui_autoport();
 314                 if (!addr->sllc_sap)
 315                         goto out;
 316         }
 317         sap = llc_sap_find(addr->sllc_sap);
 318         if (!sap) {
 319                 sap = llc_sap_open(addr->sllc_sap, NULL);
 320                 rc = -EBUSY; /* some other network layer is using the sap */
 321                 if (!sap)
 322                         goto out;
 323                 llc_sap_hold(sap);
 324         } else {
 325                 struct llc_addr laddr, daddr;
 326                 struct sock *ask;
 327
 328                 memset(&laddr, 0, sizeof(laddr));
 329                 memset(&daddr, 0, sizeof(daddr));
 330                 /*
 331                  * FIXME: check if the address is multicast,
 332                  *        only SOCK_DGRAM can do this.
 333                  */
 334                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 335                 laddr.lsap = addr->sllc_sap;
 336                 rc = -EADDRINUSE; /* mac + sap clash. */
 337                 ask = llc_lookup_established(sap, &daddr, &laddr);
 338                 if (ask) {
 339                         sock_put(ask);
 340                         goto out_put;
 341                 }
 342         }
 343         llc->laddr.lsap = addr->sllc_sap;
 344         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 345         memcpy(&llc->addr, addr, sizeof(llc->addr));
 346         /* assign new connection to its SAP */
 347         llc_sap_add_socket(sap, sk);
 348         sock_reset_flag(sk, SOCK_ZAPPED);
 349         rc = 0;
 350 out_put:
 351         llc_sap_put(sap);
 352 out:
 353         return rc;
 354 }
 355
 356 /**
 357  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 358  *      @sock: Socket to shutdown.
 359  *      @how: What part of the socket to shutdown.
 360  *
 361  *      Shutdown a connected llc2 socket. Currently this function only supports
 362  *      shutting down both sends and receives (2), we could probably make this
 363  *      function such that a user can shutdown only half the connection but not
 364  *      right now.
 365  *      Returns: 0 upon success, negative otherwise.
 366  */
 367 static int llc_ui_shutdown(struct socket *sock, int how)
 368 {
 369         struct sock *sk = sock->sk;
 370         int rc = -ENOTCONN;
 371
 372         lock_sock(sk);
 373         if (unlikely(sk->sk_state != TCP_ESTABLISHED))
 374                 goto out;
 375         rc = -EINVAL;
 376         if (how != 2)
 377                 goto out;
 378         rc = llc_send_disc(sk);
 379         if (!rc)
 380                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 381         /* Wake up anyone sleeping in poll */
 382         sk->sk_state_change(sk);
 383 out:
 384         release_sock(sk);
 385         return rc;
 386 }
 387
 388 /**
 389  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 390  *      @sock: Socket which will be connected to the remote destination.
 391  *      @uaddr: Remote and possibly the local address of the new connection.
 392  *      @addrlen: Size of uaddr structure.
 393  *      @flags: Operational flags specified by the user.
 394  *
 395  *      Connect to a remote llc2 mac + sap. The caller must specify the
 396  *      destination mac and address to connect to. If the user hasn't previously
 397  *      called bind(2) with a smac the address of the first interface of the
 398  *      specified arp type will be used.
 399  *      This function will autobind if user did not previously call bind.
 400  *      Returns: 0 upon success, negative otherwise.
 401  */
 402 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 403                           int addrlen, int flags)
 404 {
 405         struct sock *sk = sock->sk;
 406         struct llc_sock *llc = llc_sk(sk);
 407         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 408         int rc = -EINVAL;
 409
 410         lock_sock(sk);
 411         if (unlikely(addrlen != sizeof(*addr)))
 412                 goto out;
 413         rc = -EAFNOSUPPORT;
 414         if (unlikely(addr->sllc_family != AF_LLC))
 415                 goto out;
 416         if (unlikely(sk->sk_type != SOCK_STREAM))
 417                 goto out;
 418         rc = -EALREADY;
 419         if (unlikely(sock->state == SS_CONNECTING))
 420                 goto out;
 421         /* bind connection to sap if user hasn't done it. */
 422         if (sock_flag(sk, SOCK_ZAPPED)) {
 423                 /* bind to sap with null dev, exclusive */
 424                 rc = llc_ui_autobind(sock, addr);
 425                 if (rc)
 426                         goto out;
 427         }
 428         llc->daddr.lsap = addr->sllc_sap;
 429         memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 430         sock->state = SS_CONNECTING;
 431         sk->sk_state   = TCP_SYN_SENT;
 432         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 433         rc = llc_establish_connection(sk, llc->dev->dev_addr,
 434                                       addr->sllc_mac, addr->sllc_sap);
 435         if (rc) {
 436                 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
 437                 sock->state  = SS_UNCONNECTED;
 438                 sk->sk_state = TCP_CLOSE;
 439                 goto out;
 440         }
 441
 442         if (sk->sk_state == TCP_SYN_SENT) {
 443                 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 444
 445                 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
 446                         goto out;
 447
 448                 rc = sock_intr_errno(timeo);
 449                 if (signal_pending(current))
 450                         goto out;
 451         }
 452
 453         if (sk->sk_state == TCP_CLOSE)
 454                 goto sock_error;
 455
 456         sock->state = SS_CONNECTED;
 457         rc = 0;
 458 out:
 459         release_sock(sk);
 460         return rc;
 461 sock_error:
 462         rc = sock_error(sk) ? : -ECONNABORTED;
 463         sock->state = SS_UNCONNECTED;
 464         goto out;
 465 }
 466
 467 /**
 468  *      llc_ui_listen - allow a normal socket to accept incoming connections
 469  *      @sock: Socket to allow incoming connections on.
 470  *      @backlog: Number of connections to queue.
 471  *
 472  *      Allow a normal socket to accept incoming connections.
 473  *      Returns 0 upon success, negative otherwise.
 474  */
 475 static int llc_ui_listen(struct socket *sock, int backlog)
 476 {
 477         struct sock *sk = sock->sk;
 478         int rc = -EINVAL;
 479
 480         lock_sock(sk);
 481         if (unlikely(sock->state != SS_UNCONNECTED))
 482                 goto out;
 483         rc = -EOPNOTSUPP;
 484         if (unlikely(sk->sk_type != SOCK_STREAM))
 485                 goto out;
 486         rc = -EAGAIN;
 487         if (sock_flag(sk, SOCK_ZAPPED))
 488                 goto out;
 489         rc = 0;
 490         if (!(unsigned)backlog) /* BSDism */
 491                 backlog = 1;
 492         sk->sk_max_ack_backlog = backlog;
 493         if (sk->sk_state != TCP_LISTEN) {
 494                 sk->sk_ack_backlog = 0;
 495                 sk->sk_state       = TCP_LISTEN;
 496         }
 497         sk->sk_socket->flags |= __SO_ACCEPTCON;
 498 out:
 499         release_sock(sk);
 500         return rc;
 501 }
 502
 503 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
 504 {
 505         DEFINE_WAIT(wait);
 506         int rc = 0;
 507
 508         while (1) {
 509                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 510                 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE))
 511                         break;
 512                 rc = -ERESTARTSYS;
 513                 if (signal_pending(current))
 514                         break;
 515                 rc = -EAGAIN;
 516                 if (!timeout)
 517                         break;
 518                 rc = 0;
 519         }
 520         finish_wait(sk->sk_sleep, &wait);
 521         return rc;
 522 }
 523
 524 static int llc_ui_wait_for_conn(struct sock *sk, long timeout)
 525 {
 526         DEFINE_WAIT(wait);
 527
 528         while (1) {
 529                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 530                 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT))
 531                         break;
 532                 if (signal_pending(current) || !timeout)
 533                         break;
 534         }
 535         finish_wait(sk->sk_sleep, &wait);
 536         return timeout;
 537 }
 538
 539 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
 540 {
 541         DEFINE_WAIT(wait);
 542         struct llc_sock *llc = llc_sk(sk);
 543         int rc;
 544
 545         while (1) {
 546                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 547                 rc = 0;
 548                 if (sk_wait_event(sk, &timeout,
 549                                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
 550                                   (!llc_data_accept_state(llc->state) &&
 551                                    !llc->remote_busy_flag &&
 552                                    !llc->p_flag)))
 553                         break;
 554                 rc = -ERESTARTSYS;
 555                 if (signal_pending(current))
 556                         break;
 557                 rc = -EAGAIN;
 558                 if (!timeout)
 559                         break;
 560         }
 561         finish_wait(sk->sk_sleep, &wait);
 562         return rc;
 563 }
 564
 565 static int llc_wait_data(struct sock *sk, long timeo)
 566 {
 567         int rc;
 568
 569         while (1) {
 570                 /*
 571                  * POSIX 1003.1g mandates this order.
 572                  */
 573                 rc = sock_error(sk);
 574                 if (rc)
 575                         break;
 576                 rc = 0;
 577                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 578                         break;
 579                 rc = -EAGAIN;
 580                 if (!timeo)
 581                         break;
 582                 rc = sock_intr_errno(timeo);
 583                 if (signal_pending(current))
 584                         break;
 585                 rc = 0;
 586                 if (sk_wait_data(sk, &timeo))
 587                         break;
 588         }
 589         return rc;
 590 }
 591
 592 /**
 593  *      llc_ui_accept - accept a new incoming connection.
 594  *      @sock: Socket which connections arrive on.
 595  *      @newsock: Socket to move incoming connection to.
 596  *      @flags: User specified operational flags.
 597  *
 598  *      Accept a new incoming connection.
 599  *      Returns 0 upon success, negative otherwise.
 600  */
 601 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 602 {
 603         struct sock *sk = sock->sk, *newsk;
 604         struct llc_sock *llc, *newllc;
 605         struct sk_buff *skb;
 606         int rc = -EOPNOTSUPP;
 607
 608         dprintk("%s: accepting on %02X\n", __func__,
 609                 llc_sk(sk)->laddr.lsap);
 610         lock_sock(sk);
 611         if (unlikely(sk->sk_type != SOCK_STREAM))
 612                 goto out;
 613         rc = -EINVAL;
 614         if (unlikely(sock->state != SS_UNCONNECTED ||
 615                      sk->sk_state != TCP_LISTEN))
 616                 goto out;
 617         /* wait for a connection to arrive. */
 618         if (skb_queue_empty(&sk->sk_receive_queue)) {
 619                 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
 620                 if (rc)
 621                         goto out;
 622         }
 623         dprintk("%s: got a new connection on %02X\n", __func__,
 624                 llc_sk(sk)->laddr.lsap);
 625         skb = skb_dequeue(&sk->sk_receive_queue);
 626         rc = -EINVAL;
 627         if (!skb->sk)
 628                 goto frees;
 629         rc = 0;
 630         newsk = skb->sk;
 631         /* attach connection to a new socket. */
 632         llc_ui_sk_init(newsock, newsk);
 633         sock_reset_flag(newsk, SOCK_ZAPPED);
 634         newsk->sk_state         = TCP_ESTABLISHED;
 635         newsock->state          = SS_CONNECTED;
 636         llc                     = llc_sk(sk);
 637         newllc                  = llc_sk(newsk);
 638         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 639         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 640
 641         /* put original socket back into a clean listen state. */
 642         sk->sk_state = TCP_LISTEN;
 643         sk->sk_ack_backlog--;
 644         dprintk("%s: ok success on %02X, client on %02X\n", __func__,
 645                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 646 frees:
 647         kfree_skb(skb);
 648 out:
 649         release_sock(sk);
 650         return rc;
 651 }
 652
 653 /**
 654  *      llc_ui_recvmsg - copy received data to the socket user.
 655  *      @sock: Socket to copy data from.
 656  *      @msg: Various user space related information.
 657  *      @len: Size of user buffer.
 658  *      @flags: User specified flags.
 659  *
 660  *      Copy received data to the socket user.
 661  *      Returns non-negative upon success, negative otherwise.
 662  */
 663 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 664                           struct msghdr *msg, size_t len, int flags)
 665 {
 666         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 667         const int nonblock = flags & MSG_DONTWAIT;
 668         struct sk_buff *skb = NULL;
 669         struct sock *sk = sock->sk;
 670         struct llc_sock *llc = llc_sk(sk);
 671         size_t copied = 0;
 672         u32 peek_seq = 0;
 673         u32 *seq;
 674         unsigned long used;
 675         int target;     /* Read at least this many bytes */
 676         long timeo;
 677
 678         lock_sock(sk);
 679         copied = -ENOTCONN;
 680         if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
 681                 goto out;
 682
 683         timeo = sock_rcvtimeo(sk, nonblock);
 684
 685         seq = &llc->copied_seq;
 686         if (flags & MSG_PEEK) {
 687                 peek_seq = llc->copied_seq;
 688                 seq = &peek_seq;
 689         }
 690
 691         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 692         copied = 0;
 693
 694         do {
 695                 u32 offset;
 696
 697                 /*
 698                  * We need to check signals first, to get correct SIGURG
 699                  * handling. FIXME: Need to check this doesn't impact 1003.1g
 700                  * and move it down to the bottom of the loop
 701                  */
 702                 if (signal_pending(current)) {
 703                         if (copied)
 704                                 break;
 705                         copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 706                         break;
 707                 }
 708
 709                 /* Next get a buffer. */
 710
 711                 skb = skb_peek(&sk->sk_receive_queue);
 712                 if (skb) {
 713                         offset = *seq;
 714                         goto found_ok_skb;
 715                 }
 716                 /* Well, if we have backlog, try to process it now yet. */
 717
 718                 if (copied >= target && !sk->sk_backlog.tail)
 719                         break;
 720
 721                 if (copied) {
 722                         if (sk->sk_err ||
 723                             sk->sk_state == TCP_CLOSE ||
 724                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 725                             !timeo ||
 726                             (flags & MSG_PEEK))
 727                                 break;
 728                 } else {
 729                         if (sock_flag(sk, SOCK_DONE))
 730                                 break;
 731
 732                         if (sk->sk_err) {
 733                                 copied = sock_error(sk);
 734                                 break;
 735                         }
 736                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 737                                 break;
 738
 739                         if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
 740                                 if (!sock_flag(sk, SOCK_DONE)) {
 741                                         /*
 742                                          * This occurs when user tries to read
 743                                          * from never connected socket.
 744                                          */
 745                                         copied = -ENOTCONN;
 746                                         break;
 747                                 }
 748                                 break;
 749                         }
 750                         if (!timeo) {
 751                                 copied = -EAGAIN;
 752                                 break;
 753                         }
 754                 }
 755
 756                 if (copied >= target) { /* Do not sleep, just process backlog. */
 757                         release_sock(sk);
 758                         lock_sock(sk);
 759                 } else
 760                         sk_wait_data(sk, &timeo);
 761
 762                 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
 763                         if (net_ratelimit())
 764                                 printk(KERN_DEBUG "LLC(%s:%d): Application "
 765                                                   "bug, race in MSG_PEEK.\n",
 766                                        current->comm, task_pid_nr(current));
 767                         peek_seq = llc->copied_seq;
 768                 }
 769                 continue;
 770         found_ok_skb:
 771                 /* Ok so how much can we use? */
 772                 used = skb->len - offset;
 773                 if (len < used)
 774                         used = len;
 775
 776                 if (!(flags & MSG_TRUNC)) {
 777                         int rc = skb_copy_datagram_iovec(skb, offset,
 778                                                          msg->msg_iov, used);
 779                         if (rc) {
 780                                 /* Exception. Bailout! */
 781                                 if (!copied)
 782                                         copied = -EFAULT;
 783                                 break;
 784                         }
 785                 }
 786
 787                 *seq += used;
 788                 copied += used;
 789                 len -= used;
 790
 791                 if (!(flags & MSG_PEEK)) {
 792                         sk_eat_skb(sk, skb, 0);
 793                         *seq = 0;
 794                 }
 795
 796                 /* For non stream protcols we get one packet per recvmsg call */
 797                 if (sk->sk_type != SOCK_STREAM)
 798                         goto copy_uaddr;
 799
 800                 /* Partial read */
 801                 if (used + offset < skb->len)
 802                         continue;
 803         } while (len > 0);
 804
 805 out:
 806         release_sock(sk);
 807         return copied;
 808 copy_uaddr:
 809         if (uaddr != NULL && skb != NULL) {
 810                 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 811                 msg->msg_namelen = sizeof(*uaddr);
 812         }
 813         goto out;
 814 }
 815
 816 /**
 817  *      llc_ui_sendmsg - Transmit data provided by the socket user.
 818  *      @sock: Socket to transmit data from.
 819  *      @msg: Various user related information.
 820  *      @len: Length of data to transmit.
 821  *
 822  *      Transmit data provided by the socket user.
 823  *      Returns non-negative upon success, negative otherwise.
 824  */
 825 static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock,
 826                           struct msghdr *msg, size_t len)
 827 {
 828         struct sock *sk = sock->sk;
 829         struct llc_sock *llc = llc_sk(sk);
 830         struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name;
 831         int flags = msg->msg_flags;
 832         int noblock = flags & MSG_DONTWAIT;
 833         struct sk_buff *skb;
 834         size_t size = 0;
 835         int rc = -EINVAL, copied = 0, hdrlen;
 836
 837         dprintk("%s: sending from %02X to %02X\n", __func__,
 838                 llc->laddr.lsap, llc->daddr.lsap);
 839         lock_sock(sk);
 840         if (addr) {
 841                 if (msg->msg_namelen < sizeof(*addr))
 842                         goto release;
 843         } else {
 844                 if (llc_ui_addr_null(&llc->addr))
 845                         goto release;
 846                 addr = &llc->addr;
 847         }
 848         /* must bind connection to sap if user hasn't done it. */
 849         if (sock_flag(sk, SOCK_ZAPPED)) {
 850                 /* bind to sap with null dev, exclusive. */
 851                 rc = llc_ui_autobind(sock, addr);
 852                 if (rc)
 853                         goto release;
 854         }
 855         hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
 856         size = hdrlen + len;
 857         if (size > llc->dev->mtu)
 858                 size = llc->dev->mtu;
 859         copied = size - hdrlen;
 860         release_sock(sk);
 861         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 862         lock_sock(sk);
 863         if (!skb)
 864                 goto release;
 865         skb->dev      = llc->dev;
 866         skb->protocol = llc_proto_type(addr->sllc_arphrd);
 867         skb_reserve(skb, hdrlen);
 868         rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied);
 869         if (rc)
 870                 goto out;
 871         if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
 872                 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
 873                                           addr->sllc_sap);
 874                 goto out;
 875         }
 876         if (addr->sllc_test) {
 877                 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
 878                                             addr->sllc_sap);
 879                 goto out;
 880         }
 881         if (addr->sllc_xid) {
 882                 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
 883                                            addr->sllc_sap);
 884                 goto out;
 885         }
 886         rc = -ENOPROTOOPT;
 887         if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
 888                 goto out;
 889         rc = llc_ui_send_data(sk, skb, noblock);
 890 out:
 891         if (rc) {
 892                 kfree_skb(skb);
 893 release:
 894                 dprintk("%s: failed sending from %02X to %02X: %d\n",
 895                         __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
 896         }
 897         release_sock(sk);
 898         return rc ? : copied;
 899 }
 900
 901 /**
 902  *      llc_ui_getname - return the address info of a socket
 903  *      @sock: Socket to get address of.
 904  *      @uaddr: Address structure to return information.
 905  *      @uaddrlen: Length of address structure.
 906  *      @peer: Does user want local or remote address information.
 907  *
 908  *      Return the address information of a socket.
 909  */
 910 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
 911                           int *uaddrlen, int peer)
 912 {
 913         struct sockaddr_llc sllc;
 914         struct sock *sk = sock->sk;
 915         struct llc_sock *llc = llc_sk(sk);
 916         int rc = 0;
 917
 918         lock_sock(sk);
 919         if (sock_flag(sk, SOCK_ZAPPED))
 920                 goto out;
 921         *uaddrlen = sizeof(sllc);
 922         memset(uaddr, 0, *uaddrlen);
 923         if (peer) {
 924                 rc = -ENOTCONN;
 925                 if (sk->sk_state != TCP_ESTABLISHED)
 926                         goto out;
 927                 if(llc->dev)
 928                         sllc.sllc_arphrd = llc->dev->type;
 929                 sllc.sllc_sap = llc->daddr.lsap;
 930                 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
 931         } else {
 932                 rc = -EINVAL;
 933                 if (!llc->sap)
 934                         goto out;
 935                 sllc.sllc_sap = llc->sap->laddr.lsap;
 936
 937                 if (llc->dev) {
 938                         sllc.sllc_arphrd = llc->dev->type;
 939                         memcpy(&sllc.sllc_mac, &llc->dev->dev_addr,
 940                                IFHWADDRLEN);
 941                 }
 942         }
 943         rc = 0;
 944         sllc.sllc_family = AF_LLC;
 945         memcpy(uaddr, &sllc, sizeof(sllc));
 946 out:
 947         release_sock(sk);
 948         return rc;
 949 }
 950
 951 /**
 952  *      llc_ui_ioctl - io controls for PF_LLC
 953  *      @sock: Socket to get/set info
 954  *      @cmd: command
 955  *      @arg: optional argument for cmd
 956  *
 957  *      get/set info on llc sockets
 958  */
 959 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
 960                         unsigned long arg)
 961 {
 962         return -ENOIOCTLCMD;
 963 }
 964
 965 /**
 966  *      llc_ui_setsockopt - set various connection specific parameters.
 967  *      @sock: Socket to set options on.
 968  *      @level: Socket level user is requesting operations on.
 969  *      @optname: Operation name.
 970  *      @optval User provided operation data.
 971  *      @optlen: Length of optval.
 972  *
 973  *      Set various connection specific parameters.
 974  */
 975 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 976                              char __user *optval, int optlen)
 977 {
 978         struct sock *sk = sock->sk;
 979         struct llc_sock *llc = llc_sk(sk);
 980         int rc = -EINVAL, opt;
 981
 982         lock_sock(sk);
 983         if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
 984                 goto out;
 985         rc = get_user(opt, (int __user *)optval);
 986         if (rc)
 987                 goto out;
 988         rc = -EINVAL;
 989         switch (optname) {
 990         case LLC_OPT_RETRY:
 991                 if (opt > LLC_OPT_MAX_RETRY)
 992                         goto out;
 993                 llc->n2 = opt;
 994                 break;
 995         case LLC_OPT_SIZE:
 996                 if (opt > LLC_OPT_MAX_SIZE)
 997                         goto out;
 998                 llc->n1 = opt;
 999                 break;
1000         case LLC_OPT_ACK_TMR_EXP:
1001                 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1002                         goto out;
1003                 llc->ack_timer.expire = opt * HZ;
1004                 break;
1005         case LLC_OPT_P_TMR_EXP:
1006                 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1007                         goto out;
1008                 llc->pf_cycle_timer.expire = opt * HZ;
1009                 break;
1010         case LLC_OPT_REJ_TMR_EXP:
1011                 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1012                         goto out;
1013                 llc->rej_sent_timer.expire = opt * HZ;
1014                 break;
1015         case LLC_OPT_BUSY_TMR_EXP:
1016                 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1017                         goto out;
1018                 llc->busy_state_timer.expire = opt * HZ;
1019                 break;
1020         case LLC_OPT_TX_WIN:
1021                 if (opt > LLC_OPT_MAX_WIN)
1022                         goto out;
1023                 llc->k = opt;
1024                 break;
1025         case LLC_OPT_RX_WIN:
1026                 if (opt > LLC_OPT_MAX_WIN)
1027                         goto out;
1028                 llc->rw = opt;
1029                 break;
1030         default:
1031                 rc = -ENOPROTOOPT;
1032                 goto out;
1033         }
1034         rc = 0;
1035 out:
1036         release_sock(sk);
1037         return rc;
1038 }
1039
1040 /**
1041  *      llc_ui_getsockopt - get connection specific socket info
1042  *      @sock: Socket to get information from.
1043  *      @level: Socket level user is requesting operations on.
1044  *      @optname: Operation name.
1045  *      @optval: Variable to return operation data in.
1046  *      @optlen: Length of optval.
1047  *
1048  *      Get connection specific socket information.
1049  */
1050 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1051                              char __user *optval, int __user *optlen)
1052 {
1053         struct sock *sk = sock->sk;
1054         struct llc_sock *llc = llc_sk(sk);
1055         int val = 0, len = 0, rc = -EINVAL;
1056
1057         lock_sock(sk);
1058         if (unlikely(level != SOL_LLC))
1059                 goto out;
1060         rc = get_user(len, optlen);
1061         if (rc)
1062                 goto out;
1063         rc = -EINVAL;
1064         if (len != sizeof(int))
1065                 goto out;
1066         switch (optname) {
1067         case LLC_OPT_RETRY:
1068                 val = llc->n2;                                  break;
1069         case LLC_OPT_SIZE:
1070                 val = llc->n1;                                  break;
1071         case LLC_OPT_ACK_TMR_EXP:
1072                 val = llc->ack_timer.expire / HZ;               break;
1073         case LLC_OPT_P_TMR_EXP:
1074                 val = llc->pf_cycle_timer.expire / HZ;          break;
1075         case LLC_OPT_REJ_TMR_EXP:
1076                 val = llc->rej_sent_timer.expire / HZ;          break;
1077         case LLC_OPT_BUSY_TMR_EXP:
1078                 val = llc->busy_state_timer.expire / HZ;        break;
1079         case LLC_OPT_TX_WIN:
1080                 val = llc->k;                           break;
1081         case LLC_OPT_RX_WIN:
1082                 val = llc->rw;                          break;
1083         default:
1084                 rc = -ENOPROTOOPT;
1085                 goto out;
1086         }
1087         rc = 0;
1088         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1089                 rc = -EFAULT;
1090 out:
1091         release_sock(sk);
1092         return rc;
1093 }
1094
1095 static struct net_proto_family llc_ui_family_ops = {
1096         .family = PF_LLC,
1097         .create = llc_ui_create,
1098         .owner  = THIS_MODULE,
1099 };
1100
1101 static const struct proto_ops llc_ui_ops = {
1102         .family      = PF_LLC,
1103         .owner       = THIS_MODULE,
1104         .release     = llc_ui_release,
1105         .bind        = llc_ui_bind,
1106         .connect     = llc_ui_connect,
1107         .socketpair  = sock_no_socketpair,
1108         .accept      = llc_ui_accept,
1109         .getname     = llc_ui_getname,
1110         .poll        = datagram_poll,
1111         .ioctl       = llc_ui_ioctl,
1112         .listen      = llc_ui_listen,
1113         .shutdown    = llc_ui_shutdown,
1114         .setsockopt  = llc_ui_setsockopt,
1115         .getsockopt  = llc_ui_getsockopt,
1116         .sendmsg     = llc_ui_sendmsg,
1117         .recvmsg     = llc_ui_recvmsg,
1118         .mmap        = sock_no_mmap,
1119         .sendpage    = sock_no_sendpage,
1120 };
1121
1122 static char llc_proc_err_msg[] __initdata =
1123         KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1124 static char llc_sysctl_err_msg[] __initdata =
1125         KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1126 static char llc_sock_err_msg[] __initdata =
1127         KERN_CRIT "LLC: Unable to register the network family\n";
1128
1129 static int __init llc2_init(void)
1130 {
1131         int rc = proto_register(&llc_proto, 0);
1132
1133         if (rc != 0)
1134                 goto out;
1135
1136         llc_build_offset_table();
1137         llc_station_init();
1138         llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1139         rc = llc_proc_init();
1140         if (rc != 0) {
1141                 printk(llc_proc_err_msg);
1142                 goto out_unregister_llc_proto;
1143         }
1144         rc = llc_sysctl_init();
1145         if (rc) {
1146                 printk(llc_sysctl_err_msg);
1147                 goto out_proc;
1148         }
1149         rc = sock_register(&llc_ui_family_ops);
1150         if (rc) {
1151                 printk(llc_sock_err_msg);
1152                 goto out_sysctl;
1153         }
1154         llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1155         llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1156 out:
1157         return rc;
1158 out_sysctl:
1159         llc_sysctl_exit();
1160 out_proc:
1161         llc_proc_exit();
1162 out_unregister_llc_proto:
1163         proto_unregister(&llc_proto);
1164         goto out;
1165 }
1166
1167 static void __exit llc2_exit(void)
1168 {
1169         llc_station_exit();
1170         llc_remove_pack(LLC_DEST_SAP);
1171         llc_remove_pack(LLC_DEST_CONN);
1172         sock_unregister(PF_LLC);
1173         llc_proc_exit();
1174         llc_sysctl_exit();
1175         proto_unregister(&llc_proto);
1176 }
1177
1178 module_init(llc2_init);
1179 module_exit(llc2_exit);
1180
1181 MODULE_LICENSE("GPL");
1182 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1183 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1184 MODULE_ALIAS_NETPROTO(PF_LLC);