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 const 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, struct sockaddr_llc *addr)
  93 {
  94         u8 rc = LLC_PDU_LEN_U;
  95
  96         if (addr->sllc_test || addr->sllc_xid)
  97                 rc = LLC_PDU_LEN_U;
  98         else if (sk->sk_type == SOCK_STREAM)
  99                 rc = LLC_PDU_LEN_I;
 100         return rc;
 101 }
 102
 103 /**
 104  *      llc_ui_send_data - send data via reliable llc2 connection
 105  *      @sk: Connection the socket is using.
 106  *      @skb: Data the user wishes to send.
 107  *      @addr: Source and destination fields provided by the user.
 108  *      @noblock: can we block waiting for data?
 109  *
 110  *      Send data via reliable llc2 connection.
 111  *      Returns 0 upon success, non-zero if action did not succeed.
 112  */
 113 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 114 {
 115         struct llc_sock* llc = llc_sk(sk);
 116         int rc = 0;
 117
 118         if (unlikely(llc_data_accept_state(llc->state) ||
 119                      llc->remote_busy_flag ||
 120                      llc->p_flag)) {
 121                 long timeout = sock_sndtimeo(sk, noblock);
 122
 123                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 124         }
 125         if (unlikely(!rc))
 126                 rc = llc_build_and_send_pkt(sk, skb);
 127         return rc;
 128 }
 129
 130 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 131 {
 132         sk->sk_type     = sock->type;
 133         sk->sk_sleep    = &sock->wait;
 134         sk->sk_socket   = sock;
 135         sock->sk        = sk;
 136         sock->ops       = &llc_ui_ops;
 137 }
 138
 139 static struct proto llc_proto = {
 140         .name     = "LLC",
 141         .owner    = THIS_MODULE,
 142         .obj_size = sizeof(struct llc_sock),
 143 };
 144
 145 /**
 146  *      llc_ui_create - alloc and init a new llc_ui socket
 147  *      @sock: Socket to initialize and attach allocated sk to.
 148  *      @protocol: Unused.
 149  *
 150  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 151  *      socket type we have available.
 152  *      Returns 0 upon success, negative upon failure.
 153  */
 154 static int llc_ui_create(struct socket *sock, int protocol)
 155 {
 156         struct sock *sk;
 157         int rc = -ESOCKTNOSUPPORT;
 158
 159         if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
 160                 rc = -ENOMEM;
 161                 sk = llc_sk_alloc(PF_LLC, GFP_KERNEL, &llc_proto);
 162                 if (sk) {
 163                         rc = 0;
 164                         llc_ui_sk_init(sock, sk);
 165                 }
 166         }
 167         return rc;
 168 }
 169
 170 /**
 171  *      llc_ui_release - shutdown socket
 172  *      @sock: Socket to release.
 173  *
 174  *      Shutdown and deallocate an existing socket.
 175  */
 176 static int llc_ui_release(struct socket *sock)
 177 {
 178         struct sock *sk = sock->sk;
 179         struct llc_sock *llc;
 180
 181         if (unlikely(sk == NULL))
 182                 goto out;
 183         sock_hold(sk);
 184         lock_sock(sk);
 185         llc = llc_sk(sk);
 186         dprintk("%s: closing local(%02X) remote(%02X)\n", __FUNCTION__,
 187                 llc->laddr.lsap, llc->daddr.lsap);
 188         if (!llc_send_disc(sk))
 189                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 190         if (!sock_flag(sk, SOCK_ZAPPED))
 191                 llc_sap_remove_socket(llc->sap, sk);
 192         release_sock(sk);
 193         if (llc->dev)
 194                 dev_put(llc->dev);
 195         sock_put(sk);
 196         llc_sk_free(sk);
 197 out:
 198         return 0;
 199 }
 200
 201 /**
 202  *      llc_ui_autoport - provide dynamically allocate SAP number
 203  *
 204  *      Provide the caller with a dynamically allocated SAP number according
 205  *      to the rules that are set in this function. Returns: 0, upon failure,
 206  *      SAP number otherwise.
 207  */
 208 static int llc_ui_autoport(void)
 209 {
 210         struct llc_sap *sap;
 211         int i, tries = 0;
 212
 213         while (tries < LLC_SAP_DYN_TRIES) {
 214                 for (i = llc_ui_sap_last_autoport;
 215                      i < LLC_SAP_DYN_STOP; i += 2) {
 216                         sap = llc_sap_find(i);
 217                         if (!sap) {
 218                                 llc_ui_sap_last_autoport = i + 2;
 219                                 goto out;
 220                         }
 221                         llc_sap_put(sap);
 222                 }
 223                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 224                 tries++;
 225         }
 226         i = 0;
 227 out:
 228         return i;
 229 }
 230
 231 /**
 232  *      llc_ui_autobind - automatically bind a socket to a sap
 233  *      @sock: socket to bind
 234  *      @addr: address to connect to
 235  *
 236  *      Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
 237  *      specifically used llc_ui_bind to bind to an specific address/sap
 238  *
 239  *      Returns: 0 upon success, negative otherwise.
 240  */
 241 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 242 {
 243         struct sock *sk = sock->sk;
 244         struct llc_sock *llc = llc_sk(sk);
 245         struct llc_sap *sap;
 246         int rc = -EINVAL;
 247
 248         if (!sock_flag(sk, SOCK_ZAPPED))
 249                 goto out;
 250         rc = -ENODEV;
 251         llc->dev = dev_getfirstbyhwtype(addr->sllc_arphrd);
 252         if (!llc->dev)
 253                 goto out;
 254         rc = -EUSERS;
 255         llc->laddr.lsap = llc_ui_autoport();
 256         if (!llc->laddr.lsap)
 257                 goto out;
 258         rc = -EBUSY; /* some other network layer is using the sap */
 259         sap = llc_sap_open(llc->laddr.lsap, NULL);
 260         if (!sap)
 261                 goto out;
 262         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 263         memcpy(&llc->addr, addr, sizeof(llc->addr));
 264         /* assign new connection to its SAP */
 265         llc_sap_add_socket(sap, sk);
 266         sock_reset_flag(sk, SOCK_ZAPPED);
 267         rc = 0;
 268 out:
 269         return rc;
 270 }
 271
 272 /**
 273  *      llc_ui_bind - bind a socket to a specific address.
 274  *      @sock: Socket to bind an address to.
 275  *      @uaddr: Address the user wants the socket bound to.
 276  *      @addrlen: Length of the uaddr structure.
 277  *
 278  *      Bind a socket to a specific address. For llc a user is able to bind to
 279  *      a specific sap only or mac + sap.
 280  *      If the user desires to bind to a specific mac + sap, it is possible to
 281  *      have multiple sap connections via multiple macs.
 282  *      Bind and autobind for that matter must enforce the correct sap usage
 283  *      otherwise all hell will break loose.
 284  *      Returns: 0 upon success, negative otherwise.
 285  */
 286 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 287 {
 288         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 289         struct sock *sk = sock->sk;
 290         struct llc_sock *llc = llc_sk(sk);
 291         struct llc_sap *sap;
 292         int rc = -EINVAL;
 293
 294         dprintk("%s: binding %02X\n", __FUNCTION__, addr->sllc_sap);
 295         if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
 296                 goto out;
 297         rc = -EAFNOSUPPORT;
 298         if (unlikely(addr->sllc_family != AF_LLC))
 299                 goto out;
 300         rc = -ENODEV;
 301         rtnl_lock();
 302         llc->dev = dev_getbyhwaddr(addr->sllc_arphrd, addr->sllc_mac);
 303         rtnl_unlock();
 304         if (!llc->dev)
 305                 goto out;
 306         if (!addr->sllc_sap) {
 307                 rc = -EUSERS;
 308                 addr->sllc_sap = llc_ui_autoport();
 309                 if (!addr->sllc_sap)
 310                         goto out;
 311         }
 312         sap = llc_sap_find(addr->sllc_sap);
 313         if (!sap) {
 314                 sap = llc_sap_open(addr->sllc_sap, NULL);
 315                 rc = -EBUSY; /* some other network layer is using the sap */
 316                 if (!sap)
 317                         goto out;
 318                 llc_sap_hold(sap);
 319         } else {
 320                 struct llc_addr laddr, daddr;
 321                 struct sock *ask;
 322
 323                 memset(&laddr, 0, sizeof(laddr));
 324                 memset(&daddr, 0, sizeof(daddr));
 325                 /*
 326                  * FIXME: check if the the address is multicast,
 327                  *        only SOCK_DGRAM can do this.
 328                  */
 329                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 330                 laddr.lsap = addr->sllc_sap;
 331                 rc = -EADDRINUSE; /* mac + sap clash. */
 332                 ask = llc_lookup_established(sap, &daddr, &laddr);
 333                 if (ask) {
 334                         sock_put(ask);
 335                         goto out_put;
 336                 }
 337         }
 338         llc->laddr.lsap = addr->sllc_sap;
 339         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 340         memcpy(&llc->addr, addr, sizeof(llc->addr));
 341         /* assign new connection to its SAP */
 342         llc_sap_add_socket(sap, sk);
 343         sock_reset_flag(sk, SOCK_ZAPPED);
 344         rc = 0;
 345 out_put:
 346         llc_sap_put(sap);
 347 out:
 348         return rc;
 349 }
 350
 351 /**
 352  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 353  *      @sock: Socket to shutdown.
 354  *      @how: What part of the socket to shutdown.
 355  *
 356  *      Shutdown a connected llc2 socket. Currently this function only supports
 357  *      shutting down both sends and receives (2), we could probably make this
 358  *      function such that a user can shutdown only half the connection but not
 359  *      right now.
 360  *      Returns: 0 upon success, negative otherwise.
 361  */
 362 static int llc_ui_shutdown(struct socket *sock, int how)
 363 {
 364         struct sock *sk = sock->sk;
 365         int rc = -ENOTCONN;
 366
 367         lock_sock(sk);
 368         if (unlikely(sk->sk_state != TCP_ESTABLISHED))
 369                 goto out;
 370         rc = -EINVAL;
 371         if (how != 2)
 372                 goto out;
 373         rc = llc_send_disc(sk);
 374         if (!rc)
 375                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 376         /* Wake up anyone sleeping in poll */
 377         sk->sk_state_change(sk);
 378 out:
 379         release_sock(sk);
 380         return rc;
 381 }
 382
 383 /**
 384  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 385  *      @sock: Socket which will be connected to the remote destination.
 386  *      @uaddr: Remote and possibly the local address of the new connection.
 387  *      @addrlen: Size of uaddr structure.
 388  *      @flags: Operational flags specified by the user.
 389  *
 390  *      Connect to a remote llc2 mac + sap. The caller must specify the
 391  *      destination mac and address to connect to. If the user hasn't previously
 392  *      called bind(2) with a smac the address of the first interface of the
 393  *      specified arp type will be used.
 394  *      This function will autobind if user did not previously call bind.
 395  *      Returns: 0 upon success, negative otherwise.
 396  */
 397 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 398                           int addrlen, int flags)
 399 {
 400         struct sock *sk = sock->sk;
 401         struct llc_sock *llc = llc_sk(sk);
 402         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 403         int rc = -EINVAL;
 404
 405         lock_sock(sk);
 406         if (unlikely(addrlen != sizeof(*addr)))
 407                 goto out;
 408         rc = -EAFNOSUPPORT;
 409         if (unlikely(addr->sllc_family != AF_LLC))
 410                 goto out;
 411         if (unlikely(sk->sk_type != SOCK_STREAM))
 412                 goto out;
 413         rc = -EALREADY;
 414         if (unlikely(sock->state == SS_CONNECTING))
 415                 goto out;
 416         /* bind connection to sap if user hasn't done it. */
 417         if (sock_flag(sk, SOCK_ZAPPED)) {
 418                 /* bind to sap with null dev, exclusive */
 419                 rc = llc_ui_autobind(sock, addr);
 420                 if (rc)
 421                         goto out;
 422         }
 423         llc->daddr.lsap = addr->sllc_sap;
 424         memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 425         sock->state = SS_CONNECTING;
 426         sk->sk_state   = TCP_SYN_SENT;
 427         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 428         rc = llc_establish_connection(sk, llc->dev->dev_addr,
 429                                       addr->sllc_mac, addr->sllc_sap);
 430         if (rc) {
 431                 dprintk("%s: llc_ui_send_conn failed :-(\n", __FUNCTION__);
 432                 sock->state  = SS_UNCONNECTED;
 433                 sk->sk_state = TCP_CLOSE;
 434                 goto out;
 435         }
 436
 437         if (sk->sk_state == TCP_SYN_SENT) {
 438                 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 439
 440                 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
 441                         goto out;
 442
 443                 rc = sock_intr_errno(timeo);
 444                 if (signal_pending(current))
 445                         goto out;
 446         }
 447
 448         if (sk->sk_state == TCP_CLOSE)
 449                 goto sock_error;
 450
 451         sock->state = SS_CONNECTED;
 452         rc = 0;
 453 out:
 454         release_sock(sk);
 455         return rc;
 456 sock_error:
 457         rc = sock_error(sk) ? : -ECONNABORTED;
 458         sock->state = SS_UNCONNECTED;
 459         goto out;
 460 }
 461
 462 /**
 463  *      llc_ui_listen - allow a normal socket to accept incoming connections
 464  *      @sock: Socket to allow incoming connections on.
 465  *      @backlog: Number of connections to queue.
 466  *
 467  *      Allow a normal socket to accept incoming connections.
 468  *      Returns 0 upon success, negative otherwise.
 469  */
 470 static int llc_ui_listen(struct socket *sock, int backlog)
 471 {
 472         struct sock *sk = sock->sk;
 473         int rc = -EINVAL;
 474
 475         lock_sock(sk);
 476         if (unlikely(sock->state != SS_UNCONNECTED))
 477                 goto out;
 478         rc = -EOPNOTSUPP;
 479         if (unlikely(sk->sk_type != SOCK_STREAM))
 480                 goto out;
 481         rc = -EAGAIN;
 482         if (sock_flag(sk, SOCK_ZAPPED))
 483                 goto out;
 484         rc = 0;
 485         if (!(unsigned)backlog) /* BSDism */
 486                 backlog = 1;
 487         sk->sk_max_ack_backlog = backlog;
 488         if (sk->sk_state != TCP_LISTEN) {
 489                 sk->sk_ack_backlog = 0;
 490                 sk->sk_state       = TCP_LISTEN;
 491         }
 492         sk->sk_socket->flags |= __SO_ACCEPTCON;
 493 out:
 494         release_sock(sk);
 495         return rc;
 496 }
 497
 498 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
 499 {
 500         DEFINE_WAIT(wait);
 501         int rc = 0;
 502
 503         while (1) {
 504                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 505                 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE))
 506                         break;
 507                 rc = -ERESTARTSYS;
 508                 if (signal_pending(current))
 509                         break;
 510                 rc = -EAGAIN;
 511                 if (!timeout)
 512                         break;
 513                 rc = 0;
 514         }
 515         finish_wait(sk->sk_sleep, &wait);
 516         return rc;
 517 }
 518
 519 static int llc_ui_wait_for_conn(struct sock *sk, long timeout)
 520 {
 521         DEFINE_WAIT(wait);
 522
 523         while (1) {
 524                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 525                 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT))
 526                         break;
 527                 if (signal_pending(current) || !timeout)
 528                         break;
 529         }
 530         finish_wait(sk->sk_sleep, &wait);
 531         return timeout;
 532 }
 533
 534 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
 535 {
 536         DEFINE_WAIT(wait);
 537         struct llc_sock *llc = llc_sk(sk);
 538         int rc;
 539
 540         while (1) {
 541                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 542                 rc = 0;
 543                 if (sk_wait_event(sk, &timeout,
 544                                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
 545                                   (!llc_data_accept_state(llc->state) &&
 546                                    !llc->remote_busy_flag &&
 547                                    !llc->p_flag)))
 548                         break;
 549                 rc = -ERESTARTSYS;
 550                 if (signal_pending(current))
 551                         break;
 552                 rc = -EAGAIN;
 553                 if (!timeout)
 554                         break;
 555         }
 556         finish_wait(sk->sk_sleep, &wait);
 557         return rc;
 558 }
 559
 560 static int llc_wait_data(struct sock *sk, long timeo)
 561 {
 562         int rc;
 563
 564         while (1) {
 565                 /*
 566                  * POSIX 1003.1g mandates this order.
 567                  */
 568                 rc = sock_error(sk);
 569                 if (rc)
 570                         break;
 571                 rc = 0;
 572                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 573                         break;
 574                 rc = -EAGAIN;
 575                 if (!timeo)
 576                         break;
 577                 rc = sock_intr_errno(timeo);
 578                 if (signal_pending(current))
 579                         break;
 580                 rc = 0;
 581                 if (sk_wait_data(sk, &timeo))
 582                         break;
 583         }
 584         return rc;
 585 }
 586
 587 /**
 588  *      llc_ui_accept - accept a new incoming connection.
 589  *      @sock: Socket which connections arrive on.
 590  *      @newsock: Socket to move incoming connection to.
 591  *      @flags: User specified operational flags.
 592  *
 593  *      Accept a new incoming connection.
 594  *      Returns 0 upon success, negative otherwise.
 595  */
 596 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 597 {
 598         struct sock *sk = sock->sk, *newsk;
 599         struct llc_sock *llc, *newllc;
 600         struct sk_buff *skb;
 601         int rc = -EOPNOTSUPP;
 602
 603         dprintk("%s: accepting on %02X\n", __FUNCTION__,
 604                 llc_sk(sk)->laddr.lsap);
 605         lock_sock(sk);
 606         if (unlikely(sk->sk_type != SOCK_STREAM))
 607                 goto out;
 608         rc = -EINVAL;
 609         if (unlikely(sock->state != SS_UNCONNECTED ||
 610                      sk->sk_state != TCP_LISTEN))
 611                 goto out;
 612         /* wait for a connection to arrive. */
 613         if (skb_queue_empty(&sk->sk_receive_queue)) {
 614                 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
 615                 if (rc)
 616                         goto out;
 617         }
 618         dprintk("%s: got a new connection on %02X\n", __FUNCTION__,
 619                 llc_sk(sk)->laddr.lsap);
 620         skb = skb_dequeue(&sk->sk_receive_queue);
 621         rc = -EINVAL;
 622         if (!skb->sk)
 623                 goto frees;
 624         rc = 0;
 625         newsk = skb->sk;
 626         /* attach connection to a new socket. */
 627         llc_ui_sk_init(newsock, newsk);
 628         sock_reset_flag(newsk, SOCK_ZAPPED);
 629         newsk->sk_state         = TCP_ESTABLISHED;
 630         newsock->state          = SS_CONNECTED;
 631         llc                     = llc_sk(sk);
 632         newllc                  = llc_sk(newsk);
 633         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 634         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 635
 636         /* put original socket back into a clean listen state. */
 637         sk->sk_state = TCP_LISTEN;
 638         sk->sk_ack_backlog--;
 639         dprintk("%s: ok success on %02X, client on %02X\n", __FUNCTION__,
 640                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 641 frees:
 642         kfree_skb(skb);
 643 out:
 644         release_sock(sk);
 645         return rc;
 646 }
 647
 648 /**
 649  *      llc_ui_recvmsg - copy received data to the socket user.
 650  *      @sock: Socket to copy data from.
 651  *      @msg: Various user space related information.
 652  *      @len: Size of user buffer.
 653  *      @flags: User specified flags.
 654  *
 655  *      Copy received data to the socket user.
 656  *      Returns non-negative upon success, negative otherwise.
 657  */
 658 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 659                           struct msghdr *msg, size_t len, int flags)
 660 {
 661         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 662         const int nonblock = flags & MSG_DONTWAIT;
 663         struct sk_buff *skb = NULL;
 664         struct sock *sk = sock->sk;
 665         struct llc_sock *llc = llc_sk(sk);
 666         size_t copied = 0;
 667         u32 peek_seq = 0;
 668         u32 *seq;
 669         unsigned long used;
 670         int target;     /* Read at least this many bytes */
 671         long timeo;
 672
 673         lock_sock(sk);
 674         copied = -ENOTCONN;
 675         if (sk->sk_state == TCP_LISTEN)
 676                 goto out;
 677
 678         timeo = sock_rcvtimeo(sk, nonblock);
 679
 680         seq = &llc->copied_seq;
 681         if (flags & MSG_PEEK) {
 682                 peek_seq = llc->copied_seq;
 683                 seq = &peek_seq;
 684         }
 685
 686         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 687         copied = 0;
 688
 689         do {
 690                 u32 offset;
 691
 692                 /*
 693                  * We need to check signals first, to get correct SIGURG
 694                  * handling. FIXME: Need to check this doesn't impact 1003.1g
 695                  * and move it down to the bottom of the loop
 696                  */
 697                 if (signal_pending(current)) {
 698                         if (copied)
 699                                 break;
 700                         copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 701                         break;
 702                 }
 703
 704                 /* Next get a buffer. */
 705
 706                 skb = skb_peek(&sk->sk_receive_queue);
 707                 if (skb) {
 708                         offset = *seq;
 709                         goto found_ok_skb;
 710                 }
 711                 /* Well, if we have backlog, try to process it now yet. */
 712
 713                 if (copied >= target && !sk->sk_backlog.tail)
 714                         break;
 715
 716                 if (copied) {
 717                         if (sk->sk_err ||
 718                             sk->sk_state == TCP_CLOSE ||
 719                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 720                             !timeo ||
 721                             (flags & MSG_PEEK))
 722                                 break;
 723                 } else {
 724                         if (sock_flag(sk, SOCK_DONE))
 725                                 break;
 726
 727                         if (sk->sk_err) {
 728                                 copied = sock_error(sk);
 729                                 break;
 730                         }
 731                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 732                                 break;
 733
 734                         if (sk->sk_state == TCP_CLOSE) {
 735                                 if (!sock_flag(sk, SOCK_DONE)) {
 736                                         /*
 737                                          * This occurs when user tries to read
 738                                          * from never connected socket.
 739                                          */
 740                                         copied = -ENOTCONN;
 741                                         break;
 742                                 }
 743                                 break;
 744                         }
 745                         if (!timeo) {
 746                                 copied = -EAGAIN;
 747                                 break;
 748                         }
 749                 }
 750
 751                 if (copied >= target) { /* Do not sleep, just process backlog. */
 752                         release_sock(sk);
 753                         lock_sock(sk);
 754                 } else
 755                         sk_wait_data(sk, &timeo);
 756
 757                 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
 758                         if (net_ratelimit())
 759                                 printk(KERN_DEBUG "LLC(%s:%d): Application "
 760                                                   "bug, race in MSG_PEEK.\n",
 761                                        current->comm, current->pid);
 762                         peek_seq = llc->copied_seq;
 763                 }
 764                 continue;
 765         found_ok_skb:
 766                 /* Ok so how much can we use? */
 767                 used = skb->len - offset;
 768                 if (len < used)
 769                         used = len;
 770
 771                 if (!(flags & MSG_TRUNC)) {
 772                         int rc = skb_copy_datagram_iovec(skb, offset,
 773                                                          msg->msg_iov, used);
 774                         if (rc) {
 775                                 /* Exception. Bailout! */
 776                                 if (!copied)
 777                                         copied = -EFAULT;
 778                                 break;
 779                         }
 780                 }
 781
 782                 *seq += used;
 783                 copied += used;
 784                 len -= used;
 785
 786                 if (used + offset < skb->len)
 787                         continue;
 788
 789                 if (!(flags & MSG_PEEK)) {
 790                         sk_eat_skb(sk, skb);
 791                         *seq = 0;
 792                 }
 793         } while (len > 0);
 794
 795         /*
 796          * According to UNIX98, msg_name/msg_namelen are ignored
 797          * on connected socket. -ANK
 798          * But... af_llc still doesn't have separate sets of methods for
 799          * SOCK_DGRAM and SOCK_STREAM :-( So we have to do this test, will
 800          * eventually fix this tho :-) -acme
 801          */
 802         if (sk->sk_type == SOCK_DGRAM)
 803                 goto copy_uaddr;
 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", __FUNCTION__,
 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                         __FUNCTION__, 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);