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