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