net/llc/af_llc.c

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