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  *      @noblock: can we block waiting for data?
 107  *
 108  *      Send data via reliable llc2 connection.
 109  *      Returns 0 upon success, non-zero if action did not succeed.
 110  */
 111 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 112 {
 113         struct llc_sock* llc = llc_sk(sk);
 114         int rc = 0;
 115
 116         if (unlikely(llc_data_accept_state(llc->state) ||
 117                      llc->remote_busy_flag ||
 118                      llc->p_flag)) {
 119                 long timeout = sock_sndtimeo(sk, noblock);
 120
 121                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 122         }
 123         if (unlikely(!rc))
 124                 rc = llc_build_and_send_pkt(sk, skb);
 125         return rc;
 126 }
 127
 128 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 129 {
 130         sock_graft(sk, sock);
 131         sk->sk_type     = sock->type;
 132         sock->ops       = &llc_ui_ops;
 133 }
 134
 135 static struct proto llc_proto = {
 136         .name     = "LLC",
 137         .owner    = THIS_MODULE,
 138         .obj_size = sizeof(struct llc_sock),
 139 };
 140
 141 /**
 142  *      llc_ui_create - alloc and init a new llc_ui socket
 143  *      @net: network namespace (must be default network)
 144  *      @sock: Socket to initialize and attach allocated sk to.
 145  *      @protocol: Unused.
 146  *      @kern: on behalf of kernel or userspace
 147  *
 148  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 149  *      socket type we have available.
 150  *      Returns 0 upon success, negative upon failure.
 151  */
 152 static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
 153                          int kern)
 154 {
 155         struct sock *sk;
 156         int rc = -ESOCKTNOSUPPORT;
 157
 158         if (!capable(CAP_NET_RAW))
 159                 return -EPERM;
 160
 161         if (!net_eq(net, &init_net))
 162                 return -EAFNOSUPPORT;
 163
 164         if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
 165                 rc = -ENOMEM;
 166                 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto);
 167                 if (sk) {
 168                         rc = 0;
 169                         llc_ui_sk_init(sock, sk);
 170                 }
 171         }
 172         return rc;
 173 }
 174
 175 /**
 176  *      llc_ui_release - shutdown socket
 177  *      @sock: Socket to release.
 178  *
 179  *      Shutdown and deallocate an existing socket.
 180  */
 181 static int llc_ui_release(struct socket *sock)
 182 {
 183         struct sock *sk = sock->sk;
 184         struct llc_sock *llc;
 185
 186         if (unlikely(sk == NULL))
 187                 goto out;
 188         sock_hold(sk);
 189         lock_sock(sk);
 190         llc = llc_sk(sk);
 191         dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
 192                 llc->laddr.lsap, llc->daddr.lsap);
 193         if (!llc_send_disc(sk))
 194                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 195         if (!sock_flag(sk, SOCK_ZAPPED)) {
 196                 llc_sap_put(llc->sap);
 197                 llc_sap_remove_socket(llc->sap, sk);
 198         }
 199         release_sock(sk);
 200         if (llc->dev)
 201                 dev_put(llc->dev);
 202         sock_put(sk);
 203         llc_sk_free(sk);
 204 out:
 205         return 0;
 206 }
 207
 208 /**
 209  *      llc_ui_autoport - provide dynamically allocate SAP number
 210  *
 211  *      Provide the caller with a dynamically allocated SAP number according
 212  *      to the rules that are set in this function. Returns: 0, upon failure,
 213  *      SAP number otherwise.
 214  */
 215 static int llc_ui_autoport(void)
 216 {
 217         struct llc_sap *sap;
 218         int i, tries = 0;
 219
 220         while (tries < LLC_SAP_DYN_TRIES) {
 221                 for (i = llc_ui_sap_last_autoport;
 222                      i < LLC_SAP_DYN_STOP; i += 2) {
 223                         sap = llc_sap_find(i);
 224                         if (!sap) {
 225                                 llc_ui_sap_last_autoport = i + 2;
 226                                 goto out;
 227                         }
 228                         llc_sap_put(sap);
 229                 }
 230                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 231                 tries++;
 232         }
 233         i = 0;
 234 out:
 235         return i;
 236 }
 237
 238 /**
 239  *      llc_ui_autobind - automatically bind a socket to a sap
 240  *      @sock: socket to bind
 241  *      @addr: address to connect to
 242  *
 243  *      Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
 244  *      specifically used llc_ui_bind to bind to an specific address/sap
 245  *
 246  *      Returns: 0 upon success, negative otherwise.
 247  */
 248 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 249 {
 250         struct sock *sk = sock->sk;
 251         struct llc_sock *llc = llc_sk(sk);
 252         struct llc_sap *sap;
 253         int rc = -EINVAL;
 254
 255         if (!sock_flag(sk, SOCK_ZAPPED))
 256                 goto out;
 257         rc = -ENODEV;
 258         llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
 259         if (!llc->dev)
 260                 goto out;
 261         rc = -EUSERS;
 262         llc->laddr.lsap = llc_ui_autoport();
 263         if (!llc->laddr.lsap)
 264                 goto out;
 265         rc = -EBUSY; /* some other network layer is using the sap */
 266         sap = llc_sap_open(llc->laddr.lsap, NULL);
 267         if (!sap)
 268                 goto out;
 269         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 270         memcpy(&llc->addr, addr, sizeof(llc->addr));
 271         /* assign new connection to its SAP */
 272         llc_sap_add_socket(sap, sk);
 273         sock_reset_flag(sk, SOCK_ZAPPED);
 274         rc = 0;
 275 out:
 276         return rc;
 277 }
 278
 279 /**
 280  *      llc_ui_bind - bind a socket to a specific address.
 281  *      @sock: Socket to bind an address to.
 282  *      @uaddr: Address the user wants the socket bound to.
 283  *      @addrlen: Length of the uaddr structure.
 284  *
 285  *      Bind a socket to a specific address. For llc a user is able to bind to
 286  *      a specific sap only or mac + sap.
 287  *      If the user desires to bind to a specific mac + sap, it is possible to
 288  *      have multiple sap connections via multiple macs.
 289  *      Bind and autobind for that matter must enforce the correct sap usage
 290  *      otherwise all hell will break loose.
 291  *      Returns: 0 upon success, negative otherwise.
 292  */
 293 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 294 {
 295         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 296         struct sock *sk = sock->sk;
 297         struct llc_sock *llc = llc_sk(sk);
 298         struct llc_sap *sap;
 299         int rc = -EINVAL;
 300
 301         dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
 302         if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
 303                 goto out;
 304         rc = -EAFNOSUPPORT;
 305         if (unlikely(addr->sllc_family != AF_LLC))
 306                 goto out;
 307         rc = -ENODEV;
 308         rtnl_lock();
 309         llc->dev = dev_getbyhwaddr(&init_net, addr->sllc_arphrd, addr->sllc_mac);
 310         rtnl_unlock();
 311         if (!llc->dev)
 312                 goto out;
 313         if (!addr->sllc_sap) {
 314                 rc = -EUSERS;
 315                 addr->sllc_sap = llc_ui_autoport();
 316                 if (!addr->sllc_sap)
 317                         goto out;
 318         }
 319         sap = llc_sap_find(addr->sllc_sap);
 320         if (!sap) {
 321                 sap = llc_sap_open(addr->sllc_sap, NULL);
 322                 rc = -EBUSY; /* some other network layer is using the sap */
 323                 if (!sap)
 324                         goto out;
 325                 llc_sap_hold(sap);
 326         } else {
 327                 struct llc_addr laddr, daddr;
 328                 struct sock *ask;
 329
 330                 memset(&laddr, 0, sizeof(laddr));
 331                 memset(&daddr, 0, sizeof(daddr));
 332                 /*
 333                  * FIXME: check if the address is multicast,
 334                  *        only SOCK_DGRAM can do this.
 335                  */
 336                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 337                 laddr.lsap = addr->sllc_sap;
 338                 rc = -EADDRINUSE; /* mac + sap clash. */
 339                 ask = llc_lookup_established(sap, &daddr, &laddr);
 340                 if (ask) {
 341                         sock_put(ask);
 342                         goto out_put;
 343                 }
 344         }
 345         llc->laddr.lsap = addr->sllc_sap;
 346         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 347         memcpy(&llc->addr, addr, sizeof(llc->addr));
 348         /* assign new connection to its SAP */
 349         llc_sap_add_socket(sap, sk);
 350         sock_reset_flag(sk, SOCK_ZAPPED);
 351         rc = 0;
 352 out_put:
 353         llc_sap_put(sap);
 354 out:
 355         return rc;
 356 }
 357
 358 /**
 359  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 360  *      @sock: Socket to shutdown.
 361  *      @how: What part of the socket to shutdown.
 362  *
 363  *      Shutdown a connected llc2 socket. Currently this function only supports
 364  *      shutting down both sends and receives (2), we could probably make this
 365  *      function such that a user can shutdown only half the connection but not
 366  *      right now.
 367  *      Returns: 0 upon success, negative otherwise.
 368  */
 369 static int llc_ui_shutdown(struct socket *sock, int how)
 370 {
 371         struct sock *sk = sock->sk;
 372         int rc = -ENOTCONN;
 373
 374         lock_sock(sk);
 375         if (unlikely(sk->sk_state != TCP_ESTABLISHED))
 376                 goto out;
 377         rc = -EINVAL;
 378         if (how != 2)
 379                 goto out;
 380         rc = llc_send_disc(sk);
 381         if (!rc)
 382                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 383         /* Wake up anyone sleeping in poll */
 384         sk->sk_state_change(sk);
 385 out:
 386         release_sock(sk);
 387         return rc;
 388 }
 389
 390 /**
 391  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 392  *      @sock: Socket which will be connected to the remote destination.
 393  *      @uaddr: Remote and possibly the local address of the new connection.
 394  *      @addrlen: Size of uaddr structure.
 395  *      @flags: Operational flags specified by the user.
 396  *
 397  *      Connect to a remote llc2 mac + sap. The caller must specify the
 398  *      destination mac and address to connect to. If the user hasn't previously
 399  *      called bind(2) with a smac the address of the first interface of the
 400  *      specified arp type will be used.
 401  *      This function will autobind if user did not previously call bind.
 402  *      Returns: 0 upon success, negative otherwise.
 403  */
 404 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 405                           int addrlen, int flags)
 406 {
 407         struct sock *sk = sock->sk;
 408         struct llc_sock *llc = llc_sk(sk);
 409         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 410         int rc = -EINVAL;
 411
 412         lock_sock(sk);
 413         if (unlikely(addrlen != sizeof(*addr)))
 414                 goto out;
 415         rc = -EAFNOSUPPORT;
 416         if (unlikely(addr->sllc_family != AF_LLC))
 417                 goto out;
 418         if (unlikely(sk->sk_type != SOCK_STREAM))
 419                 goto out;
 420         rc = -EALREADY;
 421         if (unlikely(sock->state == SS_CONNECTING))
 422                 goto out;
 423         /* bind connection to sap if user hasn't done it. */
 424         if (sock_flag(sk, SOCK_ZAPPED)) {
 425                 /* bind to sap with null dev, exclusive */
 426                 rc = llc_ui_autobind(sock, addr);
 427                 if (rc)
 428                         goto out;
 429         }
 430         llc->daddr.lsap = addr->sllc_sap;
 431         memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 432         sock->state = SS_CONNECTING;
 433         sk->sk_state   = TCP_SYN_SENT;
 434         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 435         rc = llc_establish_connection(sk, llc->dev->dev_addr,
 436                                       addr->sllc_mac, addr->sllc_sap);
 437         if (rc) {
 438                 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
 439                 sock->state  = SS_UNCONNECTED;
 440                 sk->sk_state = TCP_CLOSE;
 441                 goto out;
 442         }
 443
 444         if (sk->sk_state == TCP_SYN_SENT) {
 445                 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 446
 447                 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
 448                         goto out;
 449
 450                 rc = sock_intr_errno(timeo);
 451                 if (signal_pending(current))
 452                         goto out;
 453         }
 454
 455         if (sk->sk_state == TCP_CLOSE)
 456                 goto sock_error;
 457
 458         sock->state = SS_CONNECTED;
 459         rc = 0;
 460 out:
 461         release_sock(sk);
 462         return rc;
 463 sock_error:
 464         rc = sock_error(sk) ? : -ECONNABORTED;
 465         sock->state = SS_UNCONNECTED;
 466         goto out;
 467 }
 468
 469 /**
 470  *      llc_ui_listen - allow a normal socket to accept incoming connections
 471  *      @sock: Socket to allow incoming connections on.
 472  *      @backlog: Number of connections to queue.
 473  *
 474  *      Allow a normal socket to accept incoming connections.
 475  *      Returns 0 upon success, negative otherwise.
 476  */
 477 static int llc_ui_listen(struct socket *sock, int backlog)
 478 {
 479         struct sock *sk = sock->sk;
 480         int rc = -EINVAL;
 481
 482         lock_sock(sk);
 483         if (unlikely(sock->state != SS_UNCONNECTED))
 484                 goto out;
 485         rc = -EOPNOTSUPP;
 486         if (unlikely(sk->sk_type != SOCK_STREAM))
 487                 goto out;
 488         rc = -EAGAIN;
 489         if (sock_flag(sk, SOCK_ZAPPED))
 490                 goto out;
 491         rc = 0;
 492         if (!(unsigned)backlog) /* BSDism */
 493                 backlog = 1;
 494         sk->sk_max_ack_backlog = backlog;
 495         if (sk->sk_state != TCP_LISTEN) {
 496                 sk->sk_ack_backlog = 0;
 497                 sk->sk_state       = TCP_LISTEN;
 498         }
 499         sk->sk_socket->flags |= __SO_ACCEPTCON;
 500 out:
 501         release_sock(sk);
 502         return rc;
 503 }
 504
 505 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
 506 {
 507         DEFINE_WAIT(wait);
 508         int rc = 0;
 509
 510         while (1) {
 511                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 512                 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE))
 513                         break;
 514                 rc = -ERESTARTSYS;
 515                 if (signal_pending(current))
 516                         break;
 517                 rc = -EAGAIN;
 518                 if (!timeout)
 519                         break;
 520                 rc = 0;
 521         }
 522         finish_wait(sk->sk_sleep, &wait);
 523         return rc;
 524 }
 525
 526 static int llc_ui_wait_for_conn(struct sock *sk, long timeout)
 527 {
 528         DEFINE_WAIT(wait);
 529
 530         while (1) {
 531                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 532                 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT))
 533                         break;
 534                 if (signal_pending(current) || !timeout)
 535                         break;
 536         }
 537         finish_wait(sk->sk_sleep, &wait);
 538         return timeout;
 539 }
 540
 541 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
 542 {
 543         DEFINE_WAIT(wait);
 544         struct llc_sock *llc = llc_sk(sk);
 545         int rc;
 546
 547         while (1) {
 548                 prepare_to_wait(sk->sk_sleep, &wait, TASK_INTERRUPTIBLE);
 549                 rc = 0;
 550                 if (sk_wait_event(sk, &timeout,
 551                                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
 552                                   (!llc_data_accept_state(llc->state) &&
 553                                    !llc->remote_busy_flag &&
 554                                    !llc->p_flag)))
 555                         break;
 556                 rc = -ERESTARTSYS;
 557                 if (signal_pending(current))
 558                         break;
 559                 rc = -EAGAIN;
 560                 if (!timeout)
 561                         break;
 562         }
 563         finish_wait(sk->sk_sleep, &wait);
 564         return rc;
 565 }
 566
 567 static int llc_wait_data(struct sock *sk, long timeo)
 568 {
 569         int rc;
 570
 571         while (1) {
 572                 /*
 573                  * POSIX 1003.1g mandates this order.
 574                  */
 575                 rc = sock_error(sk);
 576                 if (rc)
 577                         break;
 578                 rc = 0;
 579                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 580                         break;
 581                 rc = -EAGAIN;
 582                 if (!timeo)
 583                         break;
 584                 rc = sock_intr_errno(timeo);
 585                 if (signal_pending(current))
 586                         break;
 587                 rc = 0;
 588                 if (sk_wait_data(sk, &timeo))
 589                         break;
 590         }
 591         return rc;
 592 }
 593
 594 /**
 595  *      llc_ui_accept - accept a new incoming connection.
 596  *      @sock: Socket which connections arrive on.
 597  *      @newsock: Socket to move incoming connection to.
 598  *      @flags: User specified operational flags.
 599  *
 600  *      Accept a new incoming connection.
 601  *      Returns 0 upon success, negative otherwise.
 602  */
 603 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 604 {
 605         struct sock *sk = sock->sk, *newsk;
 606         struct llc_sock *llc, *newllc;
 607         struct sk_buff *skb;
 608         int rc = -EOPNOTSUPP;
 609
 610         dprintk("%s: accepting on %02X\n", __func__,
 611                 llc_sk(sk)->laddr.lsap);
 612         lock_sock(sk);
 613         if (unlikely(sk->sk_type != SOCK_STREAM))
 614                 goto out;
 615         rc = -EINVAL;
 616         if (unlikely(sock->state != SS_UNCONNECTED ||
 617                      sk->sk_state != TCP_LISTEN))
 618                 goto out;
 619         /* wait for a connection to arrive. */
 620         if (skb_queue_empty(&sk->sk_receive_queue)) {
 621                 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
 622                 if (rc)
 623                         goto out;
 624         }
 625         dprintk("%s: got a new connection on %02X\n", __func__,
 626                 llc_sk(sk)->laddr.lsap);
 627         skb = skb_dequeue(&sk->sk_receive_queue);
 628         rc = -EINVAL;
 629         if (!skb->sk)
 630                 goto frees;
 631         rc = 0;
 632         newsk = skb->sk;
 633         /* attach connection to a new socket. */
 634         llc_ui_sk_init(newsock, newsk);
 635         sock_reset_flag(newsk, SOCK_ZAPPED);
 636         newsk->sk_state         = TCP_ESTABLISHED;
 637         newsock->state          = SS_CONNECTED;
 638         llc                     = llc_sk(sk);
 639         newllc                  = llc_sk(newsk);
 640         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 641         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 642
 643         /* put original socket back into a clean listen state. */
 644         sk->sk_state = TCP_LISTEN;
 645         sk->sk_ack_backlog--;
 646         dprintk("%s: ok success on %02X, client on %02X\n", __func__,
 647                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 648 frees:
 649         kfree_skb(skb);
 650 out:
 651         release_sock(sk);
 652         return rc;
 653 }
 654
 655 /**
 656  *      llc_ui_recvmsg - copy received data to the socket user.
 657  *      @sock: Socket to copy data from.
 658  *      @msg: Various user space related information.
 659  *      @len: Size of user buffer.
 660  *      @flags: User specified flags.
 661  *
 662  *      Copy received data to the socket user.
 663  *      Returns non-negative upon success, negative otherwise.
 664  */
 665 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 666                           struct msghdr *msg, size_t len, int flags)
 667 {
 668         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 669         const int nonblock = flags & MSG_DONTWAIT;
 670         struct sk_buff *skb = NULL;
 671         struct sock *sk = sock->sk;
 672         struct llc_sock *llc = llc_sk(sk);
 673         size_t copied = 0;
 674         u32 peek_seq = 0;
 675         u32 *seq;
 676         unsigned long used;
 677         int target;     /* Read at least this many bytes */
 678         long timeo;
 679
 680         lock_sock(sk);
 681         copied = -ENOTCONN;
 682         if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
 683                 goto out;
 684
 685         timeo = sock_rcvtimeo(sk, nonblock);
 686
 687         seq = &llc->copied_seq;
 688         if (flags & MSG_PEEK) {
 689                 peek_seq = llc->copied_seq;
 690                 seq = &peek_seq;
 691         }
 692
 693         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 694         copied = 0;
 695
 696         do {
 697                 u32 offset;
 698
 699                 /*
 700                  * We need to check signals first, to get correct SIGURG
 701                  * handling. FIXME: Need to check this doesn't impact 1003.1g
 702                  * and move it down to the bottom of the loop
 703                  */
 704                 if (signal_pending(current)) {
 705                         if (copied)
 706                                 break;
 707                         copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 708                         break;
 709                 }
 710
 711                 /* Next get a buffer. */
 712
 713                 skb = skb_peek(&sk->sk_receive_queue);
 714                 if (skb) {
 715                         offset = *seq;
 716                         goto found_ok_skb;
 717                 }
 718                 /* Well, if we have backlog, try to process it now yet. */
 719
 720                 if (copied >= target && !sk->sk_backlog.tail)
 721                         break;
 722
 723                 if (copied) {
 724                         if (sk->sk_err ||
 725                             sk->sk_state == TCP_CLOSE ||
 726                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 727                             !timeo ||
 728                             (flags & MSG_PEEK))
 729                                 break;
 730                 } else {
 731                         if (sock_flag(sk, SOCK_DONE))
 732                                 break;
 733
 734                         if (sk->sk_err) {
 735                                 copied = sock_error(sk);
 736                                 break;
 737                         }
 738                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 739                                 break;
 740
 741                         if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
 742                                 if (!sock_flag(sk, SOCK_DONE)) {
 743                                         /*
 744                                          * This occurs when user tries to read
 745                                          * from never connected socket.
 746                                          */
 747                                         copied = -ENOTCONN;
 748                                         break;
 749                                 }
 750                                 break;
 751                         }
 752                         if (!timeo) {
 753                                 copied = -EAGAIN;
 754                                 break;
 755                         }
 756                 }
 757
 758                 if (copied >= target) { /* Do not sleep, just process backlog. */
 759                         release_sock(sk);
 760                         lock_sock(sk);
 761                 } else
 762                         sk_wait_data(sk, &timeo);
 763
 764                 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
 765                         if (net_ratelimit())
 766                                 printk(KERN_DEBUG "LLC(%s:%d): Application "
 767                                                   "bug, race in MSG_PEEK.\n",
 768                                        current->comm, task_pid_nr(current));
 769                         peek_seq = llc->copied_seq;
 770                 }
 771                 continue;
 772         found_ok_skb:
 773                 /* Ok so how much can we use? */
 774                 used = skb->len - offset;
 775                 if (len < used)
 776                         used = len;
 777
 778                 if (!(flags & MSG_TRUNC)) {
 779                         int rc = skb_copy_datagram_iovec(skb, offset,
 780                                                          msg->msg_iov, used);
 781                         if (rc) {
 782                                 /* Exception. Bailout! */
 783                                 if (!copied)
 784                                         copied = -EFAULT;
 785                                 break;
 786                         }
 787                 }
 788
 789                 *seq += used;
 790                 copied += used;
 791                 len -= used;
 792
 793                 if (!(flags & MSG_PEEK)) {
 794                         sk_eat_skb(sk, skb, 0);
 795                         *seq = 0;
 796                 }
 797
 798                 /* For non stream protcols we get one packet per recvmsg call */
 799                 if (sk->sk_type != SOCK_STREAM)
 800                         goto copy_uaddr;
 801
 802                 /* Partial read */
 803                 if (used + offset < skb->len)
 804                         continue;
 805         } while (len > 0);
 806
 807 out:
 808         release_sock(sk);
 809         return copied;
 810 copy_uaddr:
 811         if (uaddr != NULL && skb != NULL) {
 812                 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 813                 msg->msg_namelen = sizeof(*uaddr);
 814         }
 815         goto out;
 816 }
 817
 818 /**
 819  *      llc_ui_sendmsg - Transmit data provided by the socket user.
 820  *      @sock: Socket to transmit data from.
 821  *      @msg: Various user related information.
 822  *      @len: Length of data to transmit.
 823  *
 824  *      Transmit data provided by the socket user.
 825  *      Returns non-negative upon success, negative otherwise.
 826  */
 827 static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock,
 828                           struct msghdr *msg, size_t len)
 829 {
 830         struct sock *sk = sock->sk;
 831         struct llc_sock *llc = llc_sk(sk);
 832         struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name;
 833         int flags = msg->msg_flags;
 834         int noblock = flags & MSG_DONTWAIT;
 835         struct sk_buff *skb;
 836         size_t size = 0;
 837         int rc = -EINVAL, copied = 0, hdrlen;
 838
 839         dprintk("%s: sending from %02X to %02X\n", __func__,
 840                 llc->laddr.lsap, llc->daddr.lsap);
 841         lock_sock(sk);
 842         if (addr) {
 843                 if (msg->msg_namelen < sizeof(*addr))
 844                         goto release;
 845         } else {
 846                 if (llc_ui_addr_null(&llc->addr))
 847                         goto release;
 848                 addr = &llc->addr;
 849         }
 850         /* must bind connection to sap if user hasn't done it. */
 851         if (sock_flag(sk, SOCK_ZAPPED)) {
 852                 /* bind to sap with null dev, exclusive. */
 853                 rc = llc_ui_autobind(sock, addr);
 854                 if (rc)
 855                         goto release;
 856         }
 857         hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
 858         size = hdrlen + len;
 859         if (size > llc->dev->mtu)
 860                 size = llc->dev->mtu;
 861         copied = size - hdrlen;
 862         release_sock(sk);
 863         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 864         lock_sock(sk);
 865         if (!skb)
 866                 goto release;
 867         skb->dev      = llc->dev;
 868         skb->protocol = llc_proto_type(addr->sllc_arphrd);
 869         skb_reserve(skb, hdrlen);
 870         rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied);
 871         if (rc)
 872                 goto out;
 873         if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
 874                 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
 875                                           addr->sllc_sap);
 876                 goto out;
 877         }
 878         if (addr->sllc_test) {
 879                 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
 880                                             addr->sllc_sap);
 881                 goto out;
 882         }
 883         if (addr->sllc_xid) {
 884                 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
 885                                            addr->sllc_sap);
 886                 goto out;
 887         }
 888         rc = -ENOPROTOOPT;
 889         if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
 890                 goto out;
 891         rc = llc_ui_send_data(sk, skb, noblock);
 892 out:
 893         if (rc) {
 894                 kfree_skb(skb);
 895 release:
 896                 dprintk("%s: failed sending from %02X to %02X: %d\n",
 897                         __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
 898         }
 899         release_sock(sk);
 900         return rc ? : copied;
 901 }
 902
 903 /**
 904  *      llc_ui_getname - return the address info of a socket
 905  *      @sock: Socket to get address of.
 906  *      @uaddr: Address structure to return information.
 907  *      @uaddrlen: Length of address structure.
 908  *      @peer: Does user want local or remote address information.
 909  *
 910  *      Return the address information of a socket.
 911  */
 912 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
 913                           int *uaddrlen, int peer)
 914 {
 915         struct sockaddr_llc sllc;
 916         struct sock *sk = sock->sk;
 917         struct llc_sock *llc = llc_sk(sk);
 918         int rc = 0;
 919
 920         memset(&sllc, 0, sizeof(sllc));
 921         lock_sock(sk);
 922         if (sock_flag(sk, SOCK_ZAPPED))
 923                 goto out;
 924         *uaddrlen = sizeof(sllc);
 925         memset(uaddr, 0, *uaddrlen);
 926         if (peer) {
 927                 rc = -ENOTCONN;
 928                 if (sk->sk_state != TCP_ESTABLISHED)
 929                         goto out;
 930                 if(llc->dev)
 931                         sllc.sllc_arphrd = llc->dev->type;
 932                 sllc.sllc_sap = llc->daddr.lsap;
 933                 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
 934         } else {
 935                 rc = -EINVAL;
 936                 if (!llc->sap)
 937                         goto out;
 938                 sllc.sllc_sap = llc->sap->laddr.lsap;
 939
 940                 if (llc->dev) {
 941                         sllc.sllc_arphrd = llc->dev->type;
 942                         memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
 943                                IFHWADDRLEN);
 944                 }
 945         }
 946         rc = 0;
 947         sllc.sllc_family = AF_LLC;
 948         memcpy(uaddr, &sllc, sizeof(sllc));
 949 out:
 950         release_sock(sk);
 951         return rc;
 952 }
 953
 954 /**
 955  *      llc_ui_ioctl - io controls for PF_LLC
 956  *      @sock: Socket to get/set info
 957  *      @cmd: command
 958  *      @arg: optional argument for cmd
 959  *
 960  *      get/set info on llc sockets
 961  */
 962 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
 963                         unsigned long arg)
 964 {
 965         return -ENOIOCTLCMD;
 966 }
 967
 968 /**
 969  *      llc_ui_setsockopt - set various connection specific parameters.
 970  *      @sock: Socket to set options on.
 971  *      @level: Socket level user is requesting operations on.
 972  *      @optname: Operation name.
 973  *      @optval User provided operation data.
 974  *      @optlen: Length of optval.
 975  *
 976  *      Set various connection specific parameters.
 977  */
 978 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 979                              char __user *optval, unsigned int optlen)
 980 {
 981         struct sock *sk = sock->sk;
 982         struct llc_sock *llc = llc_sk(sk);
 983         int rc = -EINVAL, opt;
 984
 985         lock_sock(sk);
 986         if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
 987                 goto out;
 988         rc = get_user(opt, (int __user *)optval);
 989         if (rc)
 990                 goto out;
 991         rc = -EINVAL;
 992         switch (optname) {
 993         case LLC_OPT_RETRY:
 994                 if (opt > LLC_OPT_MAX_RETRY)
 995                         goto out;
 996                 llc->n2 = opt;
 997                 break;
 998         case LLC_OPT_SIZE:
 999                 if (opt > LLC_OPT_MAX_SIZE)
1000                         goto out;
1001                 llc->n1 = opt;
1002                 break;
1003         case LLC_OPT_ACK_TMR_EXP:
1004                 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1005                         goto out;
1006                 llc->ack_timer.expire = opt * HZ;
1007                 break;
1008         case LLC_OPT_P_TMR_EXP:
1009                 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1010                         goto out;
1011                 llc->pf_cycle_timer.expire = opt * HZ;
1012                 break;
1013         case LLC_OPT_REJ_TMR_EXP:
1014                 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1015                         goto out;
1016                 llc->rej_sent_timer.expire = opt * HZ;
1017                 break;
1018         case LLC_OPT_BUSY_TMR_EXP:
1019                 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1020                         goto out;
1021                 llc->busy_state_timer.expire = opt * HZ;
1022                 break;
1023         case LLC_OPT_TX_WIN:
1024                 if (opt > LLC_OPT_MAX_WIN)
1025                         goto out;
1026                 llc->k = opt;
1027                 break;
1028         case LLC_OPT_RX_WIN:
1029                 if (opt > LLC_OPT_MAX_WIN)
1030                         goto out;
1031                 llc->rw = opt;
1032                 break;
1033         default:
1034                 rc = -ENOPROTOOPT;
1035                 goto out;
1036         }
1037         rc = 0;
1038 out:
1039         release_sock(sk);
1040         return rc;
1041 }
1042
1043 /**
1044  *      llc_ui_getsockopt - get connection specific socket info
1045  *      @sock: Socket to get information from.
1046  *      @level: Socket level user is requesting operations on.
1047  *      @optname: Operation name.
1048  *      @optval: Variable to return operation data in.
1049  *      @optlen: Length of optval.
1050  *
1051  *      Get connection specific socket information.
1052  */
1053 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1054                              char __user *optval, int __user *optlen)
1055 {
1056         struct sock *sk = sock->sk;
1057         struct llc_sock *llc = llc_sk(sk);
1058         int val = 0, len = 0, rc = -EINVAL;
1059
1060         lock_sock(sk);
1061         if (unlikely(level != SOL_LLC))
1062                 goto out;
1063         rc = get_user(len, optlen);
1064         if (rc)
1065                 goto out;
1066         rc = -EINVAL;
1067         if (len != sizeof(int))
1068                 goto out;
1069         switch (optname) {
1070         case LLC_OPT_RETRY:
1071                 val = llc->n2;                                  break;
1072         case LLC_OPT_SIZE:
1073                 val = llc->n1;                                  break;
1074         case LLC_OPT_ACK_TMR_EXP:
1075                 val = llc->ack_timer.expire / HZ;               break;
1076         case LLC_OPT_P_TMR_EXP:
1077                 val = llc->pf_cycle_timer.expire / HZ;          break;
1078         case LLC_OPT_REJ_TMR_EXP:
1079                 val = llc->rej_sent_timer.expire / HZ;          break;
1080         case LLC_OPT_BUSY_TMR_EXP:
1081                 val = llc->busy_state_timer.expire / HZ;        break;
1082         case LLC_OPT_TX_WIN:
1083                 val = llc->k;                           break;
1084         case LLC_OPT_RX_WIN:
1085                 val = llc->rw;                          break;
1086         default:
1087                 rc = -ENOPROTOOPT;
1088                 goto out;
1089         }
1090         rc = 0;
1091         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1092                 rc = -EFAULT;
1093 out:
1094         release_sock(sk);
1095         return rc;
1096 }
1097
1098 static const struct net_proto_family llc_ui_family_ops = {
1099         .family = PF_LLC,
1100         .create = llc_ui_create,
1101         .owner  = THIS_MODULE,
1102 };
1103
1104 static const struct proto_ops llc_ui_ops = {
1105         .family      = PF_LLC,
1106         .owner       = THIS_MODULE,
1107         .release     = llc_ui_release,
1108         .bind        = llc_ui_bind,
1109         .connect     = llc_ui_connect,
1110         .socketpair  = sock_no_socketpair,
1111         .accept      = llc_ui_accept,
1112         .getname     = llc_ui_getname,
1113         .poll        = datagram_poll,
1114         .ioctl       = llc_ui_ioctl,
1115         .listen      = llc_ui_listen,
1116         .shutdown    = llc_ui_shutdown,
1117         .setsockopt  = llc_ui_setsockopt,
1118         .getsockopt  = llc_ui_getsockopt,
1119         .sendmsg     = llc_ui_sendmsg,
1120         .recvmsg     = llc_ui_recvmsg,
1121         .mmap        = sock_no_mmap,
1122         .sendpage    = sock_no_sendpage,
1123 };
1124
1125 static const char llc_proc_err_msg[] __initconst =
1126         KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1127 static const char llc_sysctl_err_msg[] __initconst =
1128         KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1129 static const char llc_sock_err_msg[] __initconst =
1130         KERN_CRIT "LLC: Unable to register the network family\n";
1131
1132 static int __init llc2_init(void)
1133 {
1134         int rc = proto_register(&llc_proto, 0);
1135
1136         if (rc != 0)
1137                 goto out;
1138
1139         llc_build_offset_table();
1140         llc_station_init();
1141         llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1142         rc = llc_proc_init();
1143         if (rc != 0) {
1144                 printk(llc_proc_err_msg);
1145                 goto out_unregister_llc_proto;
1146         }
1147         rc = llc_sysctl_init();
1148         if (rc) {
1149                 printk(llc_sysctl_err_msg);
1150                 goto out_proc;
1151         }
1152         rc = sock_register(&llc_ui_family_ops);
1153         if (rc) {
1154                 printk(llc_sock_err_msg);
1155                 goto out_sysctl;
1156         }
1157         llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1158         llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1159 out:
1160         return rc;
1161 out_sysctl:
1162         llc_sysctl_exit();
1163 out_proc:
1164         llc_proc_exit();
1165 out_unregister_llc_proto:
1166         proto_unregister(&llc_proto);
1167         goto out;
1168 }
1169
1170 static void __exit llc2_exit(void)
1171 {
1172         llc_station_exit();
1173         llc_remove_pack(LLC_DEST_SAP);
1174         llc_remove_pack(LLC_DEST_CONN);
1175         sock_unregister(PF_LLC);
1176         llc_proc_exit();
1177         llc_sysctl_exit();
1178         proto_unregister(&llc_proto);
1179 }
1180
1181 module_init(llc2_init);
1182 module_exit(llc2_exit);
1183
1184 MODULE_LICENSE("GPL");
1185 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1186 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1187 MODULE_ALIAS_NETPROTO(PF_LLC);