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 <linux/slab.h>
  29 #include <net/llc.h>
  30 #include <net/llc_sap.h>
  31 #include <net/llc_pdu.h>
  32 #include <net/llc_conn.h>
  33 #include <net/tcp_states.h>
  34
  35 /* remember: uninitialized global data is zeroed because its in .bss */
  36 static u16 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
  37 static u16 llc_ui_sap_link_no_max[256];
  38 static struct sockaddr_llc llc_ui_addrnull;
  39 static const struct proto_ops llc_ui_ops;
  40
  41 static int llc_ui_wait_for_conn(struct sock *sk, long timeout);
  42 static int llc_ui_wait_for_disc(struct sock *sk, long timeout);
  43 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout);
  44
  45 #if 0
  46 #define dprintk(args...) printk(KERN_DEBUG args)
  47 #else
  48 #define dprintk(args...)
  49 #endif
  50
  51 /* Maybe we'll add some more in the future. */
  52 #define LLC_CMSG_PKTINFO        1
  53
  54
  55 /**
  56  *      llc_ui_next_link_no - return the next unused link number for a sap
  57  *      @sap: Address of sap to get link number from.
  58  *
  59  *      Return the next unused link number for a given sap.
  60  */
  61 static inline u16 llc_ui_next_link_no(int sap)
  62 {
  63         return llc_ui_sap_link_no_max[sap]++;
  64 }
  65
  66 /**
  67  *      llc_proto_type - return eth protocol for ARP header type
  68  *      @arphrd: ARP header type.
  69  *
  70  *      Given an ARP header type return the corresponding ethernet protocol.
  71  */
  72 static inline __be16 llc_proto_type(u16 arphrd)
  73 {
  74         return htons(ETH_P_802_2);
  75 }
  76
  77 /**
  78  *      llc_ui_addr_null - determines if a address structure is null
  79  *      @addr: Address to test if null.
  80  */
  81 static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
  82 {
  83         return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
  84 }
  85
  86 /**
  87  *      llc_ui_header_len - return length of llc header based on operation
  88  *      @sk: Socket which contains a valid llc socket type.
  89  *      @addr: Complete sockaddr_llc structure received from the user.
  90  *
  91  *      Provide the length of the llc header depending on what kind of
  92  *      operation the user would like to perform and the type of socket.
  93  *      Returns the correct llc header length.
  94  */
  95 static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
  96 {
  97         u8 rc = LLC_PDU_LEN_U;
  98
  99         if (addr->sllc_test || addr->sllc_xid)
 100                 rc = LLC_PDU_LEN_U;
 101         else if (sk->sk_type == SOCK_STREAM)
 102                 rc = LLC_PDU_LEN_I;
 103         return rc;
 104 }
 105
 106 /**
 107  *      llc_ui_send_data - send data via reliable llc2 connection
 108  *      @sk: Connection the socket is using.
 109  *      @skb: Data the user wishes to send.
 110  *      @noblock: can we block waiting for data?
 111  *
 112  *      Send data via reliable llc2 connection.
 113  *      Returns 0 upon success, non-zero if action did not succeed.
 114  */
 115 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 116 {
 117         struct llc_sock* llc = llc_sk(sk);
 118         int rc = 0;
 119
 120         if (unlikely(llc_data_accept_state(llc->state) ||
 121                      llc->remote_busy_flag ||
 122                      llc->p_flag)) {
 123                 long timeout = sock_sndtimeo(sk, noblock);
 124
 125                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 126         }
 127         if (unlikely(!rc))
 128                 rc = llc_build_and_send_pkt(sk, skb);
 129         return rc;
 130 }
 131
 132 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 133 {
 134         sock_graft(sk, sock);
 135         sk->sk_type     = sock->type;
 136         sock->ops       = &llc_ui_ops;
 137 }
 138
 139 static struct proto llc_proto = {
 140         .name     = "LLC",
 141         .owner    = THIS_MODULE,
 142         .obj_size = sizeof(struct llc_sock),
 143         .slab_flags = SLAB_DESTROY_BY_RCU,
 144 };
 145
 146 /**
 147  *      llc_ui_create - alloc and init a new llc_ui socket
 148  *      @net: network namespace (must be default network)
 149  *      @sock: Socket to initialize and attach allocated sk to.
 150  *      @protocol: Unused.
 151  *      @kern: on behalf of kernel or userspace
 152  *
 153  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 154  *      socket type we have available.
 155  *      Returns 0 upon success, negative upon failure.
 156  */
 157 static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
 158                          int kern)
 159 {
 160         struct sock *sk;
 161         int rc = -ESOCKTNOSUPPORT;
 162
 163         if (!ns_capable(net->user_ns, CAP_NET_RAW))
 164                 return -EPERM;
 165
 166         if (!net_eq(net, &init_net))
 167                 return -EAFNOSUPPORT;
 168
 169         if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
 170                 rc = -ENOMEM;
 171                 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto);
 172                 if (sk) {
 173                         rc = 0;
 174                         llc_ui_sk_init(sock, sk);
 175                 }
 176         }
 177         return rc;
 178 }
 179
 180 /**
 181  *      llc_ui_release - shutdown socket
 182  *      @sock: Socket to release.
 183  *
 184  *      Shutdown and deallocate an existing socket.
 185  */
 186 static int llc_ui_release(struct socket *sock)
 187 {
 188         struct sock *sk = sock->sk;
 189         struct llc_sock *llc;
 190
 191         if (unlikely(sk == NULL))
 192                 goto out;
 193         sock_hold(sk);
 194         lock_sock(sk);
 195         llc = llc_sk(sk);
 196         dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
 197                 llc->laddr.lsap, llc->daddr.lsap);
 198         if (!llc_send_disc(sk))
 199                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 200         if (!sock_flag(sk, SOCK_ZAPPED))
 201                 llc_sap_remove_socket(llc->sap, sk);
 202         release_sock(sk);
 203         if (llc->dev)
 204                 dev_put(llc->dev);
 205         sock_put(sk);
 206         llc_sk_free(sk);
 207 out:
 208         return 0;
 209 }
 210
 211 /**
 212  *      llc_ui_autoport - provide dynamically allocate SAP number
 213  *
 214  *      Provide the caller with a dynamically allocated SAP number according
 215  *      to the rules that are set in this function. Returns: 0, upon failure,
 216  *      SAP number otherwise.
 217  */
 218 static int llc_ui_autoport(void)
 219 {
 220         struct llc_sap *sap;
 221         int i, tries = 0;
 222
 223         while (tries < LLC_SAP_DYN_TRIES) {
 224                 for (i = llc_ui_sap_last_autoport;
 225                      i < LLC_SAP_DYN_STOP; i += 2) {
 226                         sap = llc_sap_find(i);
 227                         if (!sap) {
 228                                 llc_ui_sap_last_autoport = i + 2;
 229                                 goto out;
 230                         }
 231                         llc_sap_put(sap);
 232                 }
 233                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 234                 tries++;
 235         }
 236         i = 0;
 237 out:
 238         return i;
 239 }
 240
 241 /**
 242  *      llc_ui_autobind - automatically bind a socket to a sap
 243  *      @sock: socket to bind
 244  *      @addr: address to connect to
 245  *
 246  *      Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
 247  *      specifically used llc_ui_bind to bind to an specific address/sap
 248  *
 249  *      Returns: 0 upon success, negative otherwise.
 250  */
 251 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 252 {
 253         struct sock *sk = sock->sk;
 254         struct llc_sock *llc = llc_sk(sk);
 255         struct llc_sap *sap;
 256         int rc = -EINVAL;
 257
 258         if (!sock_flag(sk, SOCK_ZAPPED))
 259                 goto out;
 260         rc = -ENODEV;
 261         if (sk->sk_bound_dev_if) {
 262                 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
 263                 if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
 264                         dev_put(llc->dev);
 265                         llc->dev = NULL;
 266                 }
 267         } else
 268                 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
 269         if (!llc->dev)
 270                 goto out;
 271         rc = -EUSERS;
 272         llc->laddr.lsap = llc_ui_autoport();
 273         if (!llc->laddr.lsap)
 274                 goto out;
 275         rc = -EBUSY; /* some other network layer is using the sap */
 276         sap = llc_sap_open(llc->laddr.lsap, NULL);
 277         if (!sap)
 278                 goto out;
 279         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 280         memcpy(&llc->addr, addr, sizeof(llc->addr));
 281         /* assign new connection to its SAP */
 282         llc_sap_add_socket(sap, sk);
 283         sock_reset_flag(sk, SOCK_ZAPPED);
 284         rc = 0;
 285 out:
 286         return rc;
 287 }
 288
 289 /**
 290  *      llc_ui_bind - bind a socket to a specific address.
 291  *      @sock: Socket to bind an address to.
 292  *      @uaddr: Address the user wants the socket bound to.
 293  *      @addrlen: Length of the uaddr structure.
 294  *
 295  *      Bind a socket to a specific address. For llc a user is able to bind to
 296  *      a specific sap only or mac + sap.
 297  *      If the user desires to bind to a specific mac + sap, it is possible to
 298  *      have multiple sap connections via multiple macs.
 299  *      Bind and autobind for that matter must enforce the correct sap usage
 300  *      otherwise all hell will break loose.
 301  *      Returns: 0 upon success, negative otherwise.
 302  */
 303 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 304 {
 305         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 306         struct sock *sk = sock->sk;
 307         struct llc_sock *llc = llc_sk(sk);
 308         struct llc_sap *sap;
 309         int rc = -EINVAL;
 310
 311         dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
 312         if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
 313                 goto out;
 314         rc = -EAFNOSUPPORT;
 315         if (unlikely(addr->sllc_family != AF_LLC))
 316                 goto out;
 317         rc = -ENODEV;
 318         rcu_read_lock();
 319         if (sk->sk_bound_dev_if) {
 320                 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
 321                 if (llc->dev) {
 322                         if (!addr->sllc_arphrd)
 323                                 addr->sllc_arphrd = llc->dev->type;
 324                         if (llc_mac_null(addr->sllc_mac))
 325                                 memcpy(addr->sllc_mac, llc->dev->dev_addr,
 326                                        IFHWADDRLEN);
 327                         if (addr->sllc_arphrd != llc->dev->type ||
 328                             !llc_mac_match(addr->sllc_mac,
 329                                            llc->dev->dev_addr)) {
 330                                 rc = -EINVAL;
 331                                 llc->dev = NULL;
 332                         }
 333                 }
 334         } else
 335                 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
 336                                            addr->sllc_mac);
 337         if (llc->dev)
 338                 dev_hold(llc->dev);
 339         rcu_read_unlock();
 340         if (!llc->dev)
 341                 goto out;
 342         if (!addr->sllc_sap) {
 343                 rc = -EUSERS;
 344                 addr->sllc_sap = llc_ui_autoport();
 345                 if (!addr->sllc_sap)
 346                         goto out;
 347         }
 348         sap = llc_sap_find(addr->sllc_sap);
 349         if (!sap) {
 350                 sap = llc_sap_open(addr->sllc_sap, NULL);
 351                 rc = -EBUSY; /* some other network layer is using the sap */
 352                 if (!sap)
 353                         goto out;
 354         } else {
 355                 struct llc_addr laddr, daddr;
 356                 struct sock *ask;
 357
 358                 memset(&laddr, 0, sizeof(laddr));
 359                 memset(&daddr, 0, sizeof(daddr));
 360                 /*
 361                  * FIXME: check if the address is multicast,
 362                  *        only SOCK_DGRAM can do this.
 363                  */
 364                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 365                 laddr.lsap = addr->sllc_sap;
 366                 rc = -EADDRINUSE; /* mac + sap clash. */
 367                 ask = llc_lookup_established(sap, &daddr, &laddr);
 368                 if (ask) {
 369                         sock_put(ask);
 370                         goto out_put;
 371                 }
 372         }
 373         llc->laddr.lsap = addr->sllc_sap;
 374         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 375         memcpy(&llc->addr, addr, sizeof(llc->addr));
 376         /* assign new connection to its SAP */
 377         llc_sap_add_socket(sap, sk);
 378         sock_reset_flag(sk, SOCK_ZAPPED);
 379         rc = 0;
 380 out_put:
 381         llc_sap_put(sap);
 382 out:
 383         return rc;
 384 }
 385
 386 /**
 387  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 388  *      @sock: Socket to shutdown.
 389  *      @how: What part of the socket to shutdown.
 390  *
 391  *      Shutdown a connected llc2 socket. Currently this function only supports
 392  *      shutting down both sends and receives (2), we could probably make this
 393  *      function such that a user can shutdown only half the connection but not
 394  *      right now.
 395  *      Returns: 0 upon success, negative otherwise.
 396  */
 397 static int llc_ui_shutdown(struct socket *sock, int how)
 398 {
 399         struct sock *sk = sock->sk;
 400         int rc = -ENOTCONN;
 401
 402         lock_sock(sk);
 403         if (unlikely(sk->sk_state != TCP_ESTABLISHED))
 404                 goto out;
 405         rc = -EINVAL;
 406         if (how != 2)
 407                 goto out;
 408         rc = llc_send_disc(sk);
 409         if (!rc)
 410                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 411         /* Wake up anyone sleeping in poll */
 412         sk->sk_state_change(sk);
 413 out:
 414         release_sock(sk);
 415         return rc;
 416 }
 417
 418 /**
 419  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 420  *      @sock: Socket which will be connected to the remote destination.
 421  *      @uaddr: Remote and possibly the local address of the new connection.
 422  *      @addrlen: Size of uaddr structure.
 423  *      @flags: Operational flags specified by the user.
 424  *
 425  *      Connect to a remote llc2 mac + sap. The caller must specify the
 426  *      destination mac and address to connect to. If the user hasn't previously
 427  *      called bind(2) with a smac the address of the first interface of the
 428  *      specified arp type will be used.
 429  *      This function will autobind if user did not previously call bind.
 430  *      Returns: 0 upon success, negative otherwise.
 431  */
 432 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 433                           int addrlen, int flags)
 434 {
 435         struct sock *sk = sock->sk;
 436         struct llc_sock *llc = llc_sk(sk);
 437         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 438         int rc = -EINVAL;
 439
 440         lock_sock(sk);
 441         if (unlikely(addrlen != sizeof(*addr)))
 442                 goto out;
 443         rc = -EAFNOSUPPORT;
 444         if (unlikely(addr->sllc_family != AF_LLC))
 445                 goto out;
 446         if (unlikely(sk->sk_type != SOCK_STREAM))
 447                 goto out;
 448         rc = -EALREADY;
 449         if (unlikely(sock->state == SS_CONNECTING))
 450                 goto out;
 451         /* bind connection to sap if user hasn't done it. */
 452         if (sock_flag(sk, SOCK_ZAPPED)) {
 453                 /* bind to sap with null dev, exclusive */
 454                 rc = llc_ui_autobind(sock, addr);
 455                 if (rc)
 456                         goto out;
 457         }
 458         llc->daddr.lsap = addr->sllc_sap;
 459         memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 460         sock->state = SS_CONNECTING;
 461         sk->sk_state   = TCP_SYN_SENT;
 462         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 463         rc = llc_establish_connection(sk, llc->dev->dev_addr,
 464                                       addr->sllc_mac, addr->sllc_sap);
 465         if (rc) {
 466                 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
 467                 sock->state  = SS_UNCONNECTED;
 468                 sk->sk_state = TCP_CLOSE;
 469                 goto out;
 470         }
 471
 472         if (sk->sk_state == TCP_SYN_SENT) {
 473                 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 474
 475                 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
 476                         goto out;
 477
 478                 rc = sock_intr_errno(timeo);
 479                 if (signal_pending(current))
 480                         goto out;
 481         }
 482
 483         if (sk->sk_state == TCP_CLOSE)
 484                 goto sock_error;
 485
 486         sock->state = SS_CONNECTED;
 487         rc = 0;
 488 out:
 489         release_sock(sk);
 490         return rc;
 491 sock_error:
 492         rc = sock_error(sk) ? : -ECONNABORTED;
 493         sock->state = SS_UNCONNECTED;
 494         goto out;
 495 }
 496
 497 /**
 498  *      llc_ui_listen - allow a normal socket to accept incoming connections
 499  *      @sock: Socket to allow incoming connections on.
 500  *      @backlog: Number of connections to queue.
 501  *
 502  *      Allow a normal socket to accept incoming connections.
 503  *      Returns 0 upon success, negative otherwise.
 504  */
 505 static int llc_ui_listen(struct socket *sock, int backlog)
 506 {
 507         struct sock *sk = sock->sk;
 508         int rc = -EINVAL;
 509
 510         lock_sock(sk);
 511         if (unlikely(sock->state != SS_UNCONNECTED))
 512                 goto out;
 513         rc = -EOPNOTSUPP;
 514         if (unlikely(sk->sk_type != SOCK_STREAM))
 515                 goto out;
 516         rc = -EAGAIN;
 517         if (sock_flag(sk, SOCK_ZAPPED))
 518                 goto out;
 519         rc = 0;
 520         if (!(unsigned int)backlog)     /* BSDism */
 521                 backlog = 1;
 522         sk->sk_max_ack_backlog = backlog;
 523         if (sk->sk_state != TCP_LISTEN) {
 524                 sk->sk_ack_backlog = 0;
 525                 sk->sk_state       = TCP_LISTEN;
 526         }
 527         sk->sk_socket->flags |= __SO_ACCEPTCON;
 528 out:
 529         release_sock(sk);
 530         return rc;
 531 }
 532
 533 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
 534 {
 535         DEFINE_WAIT(wait);
 536         int rc = 0;
 537
 538         while (1) {
 539                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 540                 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE))
 541                         break;
 542                 rc = -ERESTARTSYS;
 543                 if (signal_pending(current))
 544                         break;
 545                 rc = -EAGAIN;
 546                 if (!timeout)
 547                         break;
 548                 rc = 0;
 549         }
 550         finish_wait(sk_sleep(sk), &wait);
 551         return rc;
 552 }
 553
 554 static int llc_ui_wait_for_conn(struct sock *sk, long timeout)
 555 {
 556         DEFINE_WAIT(wait);
 557
 558         while (1) {
 559                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 560                 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT))
 561                         break;
 562                 if (signal_pending(current) || !timeout)
 563                         break;
 564         }
 565         finish_wait(sk_sleep(sk), &wait);
 566         return timeout;
 567 }
 568
 569 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
 570 {
 571         DEFINE_WAIT(wait);
 572         struct llc_sock *llc = llc_sk(sk);
 573         int rc;
 574
 575         while (1) {
 576                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 577                 rc = 0;
 578                 if (sk_wait_event(sk, &timeout,
 579                                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
 580                                   (!llc_data_accept_state(llc->state) &&
 581                                    !llc->remote_busy_flag &&
 582                                    !llc->p_flag)))
 583                         break;
 584                 rc = -ERESTARTSYS;
 585                 if (signal_pending(current))
 586                         break;
 587                 rc = -EAGAIN;
 588                 if (!timeout)
 589                         break;
 590         }
 591         finish_wait(sk_sleep(sk), &wait);
 592         return rc;
 593 }
 594
 595 static int llc_wait_data(struct sock *sk, long timeo)
 596 {
 597         int rc;
 598
 599         while (1) {
 600                 /*
 601                  * POSIX 1003.1g mandates this order.
 602                  */
 603                 rc = sock_error(sk);
 604                 if (rc)
 605                         break;
 606                 rc = 0;
 607                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 608                         break;
 609                 rc = -EAGAIN;
 610                 if (!timeo)
 611                         break;
 612                 rc = sock_intr_errno(timeo);
 613                 if (signal_pending(current))
 614                         break;
 615                 rc = 0;
 616                 if (sk_wait_data(sk, &timeo))
 617                         break;
 618         }
 619         return rc;
 620 }
 621
 622 static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
 623 {
 624         struct llc_sock *llc = llc_sk(skb->sk);
 625
 626         if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
 627                 struct llc_pktinfo info;
 628
 629                 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
 630                 llc_pdu_decode_dsap(skb, &info.lpi_sap);
 631                 llc_pdu_decode_da(skb, info.lpi_mac);
 632                 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
 633         }
 634 }
 635
 636 /**
 637  *      llc_ui_accept - accept a new incoming connection.
 638  *      @sock: Socket which connections arrive on.
 639  *      @newsock: Socket to move incoming connection to.
 640  *      @flags: User specified operational flags.
 641  *
 642  *      Accept a new incoming connection.
 643  *      Returns 0 upon success, negative otherwise.
 644  */
 645 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 646 {
 647         struct sock *sk = sock->sk, *newsk;
 648         struct llc_sock *llc, *newllc;
 649         struct sk_buff *skb;
 650         int rc = -EOPNOTSUPP;
 651
 652         dprintk("%s: accepting on %02X\n", __func__,
 653                 llc_sk(sk)->laddr.lsap);
 654         lock_sock(sk);
 655         if (unlikely(sk->sk_type != SOCK_STREAM))
 656                 goto out;
 657         rc = -EINVAL;
 658         if (unlikely(sock->state != SS_UNCONNECTED ||
 659                      sk->sk_state != TCP_LISTEN))
 660                 goto out;
 661         /* wait for a connection to arrive. */
 662         if (skb_queue_empty(&sk->sk_receive_queue)) {
 663                 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
 664                 if (rc)
 665                         goto out;
 666         }
 667         dprintk("%s: got a new connection on %02X\n", __func__,
 668                 llc_sk(sk)->laddr.lsap);
 669         skb = skb_dequeue(&sk->sk_receive_queue);
 670         rc = -EINVAL;
 671         if (!skb->sk)
 672                 goto frees;
 673         rc = 0;
 674         newsk = skb->sk;
 675         /* attach connection to a new socket. */
 676         llc_ui_sk_init(newsock, newsk);
 677         sock_reset_flag(newsk, SOCK_ZAPPED);
 678         newsk->sk_state         = TCP_ESTABLISHED;
 679         newsock->state          = SS_CONNECTED;
 680         llc                     = llc_sk(sk);
 681         newllc                  = llc_sk(newsk);
 682         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 683         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 684
 685         /* put original socket back into a clean listen state. */
 686         sk->sk_state = TCP_LISTEN;
 687         sk->sk_ack_backlog--;
 688         dprintk("%s: ok success on %02X, client on %02X\n", __func__,
 689                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 690 frees:
 691         kfree_skb(skb);
 692 out:
 693         release_sock(sk);
 694         return rc;
 695 }
 696
 697 /**
 698  *      llc_ui_recvmsg - copy received data to the socket user.
 699  *      @sock: Socket to copy data from.
 700  *      @msg: Various user space related information.
 701  *      @len: Size of user buffer.
 702  *      @flags: User specified flags.
 703  *
 704  *      Copy received data to the socket user.
 705  *      Returns non-negative upon success, negative otherwise.
 706  */
 707 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 708                           struct msghdr *msg, size_t len, int flags)
 709 {
 710         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 711         const int nonblock = flags & MSG_DONTWAIT;
 712         struct sk_buff *skb = NULL;
 713         struct sock *sk = sock->sk;
 714         struct llc_sock *llc = llc_sk(sk);
 715         unsigned long cpu_flags;
 716         size_t copied = 0;
 717         u32 peek_seq = 0;
 718         u32 *seq;
 719         unsigned long used;
 720         int target;     /* Read at least this many bytes */
 721         long timeo;
 722
 723         msg->msg_namelen = 0;
 724
 725         lock_sock(sk);
 726         copied = -ENOTCONN;
 727         if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
 728                 goto out;
 729
 730         timeo = sock_rcvtimeo(sk, nonblock);
 731
 732         seq = &llc->copied_seq;
 733         if (flags & MSG_PEEK) {
 734                 peek_seq = llc->copied_seq;
 735                 seq = &peek_seq;
 736         }
 737
 738         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 739         copied = 0;
 740
 741         do {
 742                 u32 offset;
 743
 744                 /*
 745                  * We need to check signals first, to get correct SIGURG
 746                  * handling. FIXME: Need to check this doesn't impact 1003.1g
 747                  * and move it down to the bottom of the loop
 748                  */
 749                 if (signal_pending(current)) {
 750                         if (copied)
 751                                 break;
 752                         copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 753                         break;
 754                 }
 755
 756                 /* Next get a buffer. */
 757
 758                 skb = skb_peek(&sk->sk_receive_queue);
 759                 if (skb) {
 760                         offset = *seq;
 761                         goto found_ok_skb;
 762                 }
 763                 /* Well, if we have backlog, try to process it now yet. */
 764
 765                 if (copied >= target && !sk->sk_backlog.tail)
 766                         break;
 767
 768                 if (copied) {
 769                         if (sk->sk_err ||
 770                             sk->sk_state == TCP_CLOSE ||
 771                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 772                             !timeo ||
 773                             (flags & MSG_PEEK))
 774                                 break;
 775                 } else {
 776                         if (sock_flag(sk, SOCK_DONE))
 777                                 break;
 778
 779                         if (sk->sk_err) {
 780                                 copied = sock_error(sk);
 781                                 break;
 782                         }
 783                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 784                                 break;
 785
 786                         if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
 787                                 if (!sock_flag(sk, SOCK_DONE)) {
 788                                         /*
 789                                          * This occurs when user tries to read
 790                                          * from never connected socket.
 791                                          */
 792                                         copied = -ENOTCONN;
 793                                         break;
 794                                 }
 795                                 break;
 796                         }
 797                         if (!timeo) {
 798                                 copied = -EAGAIN;
 799                                 break;
 800                         }
 801                 }
 802
 803                 if (copied >= target) { /* Do not sleep, just process backlog. */
 804                         release_sock(sk);
 805                         lock_sock(sk);
 806                 } else
 807                         sk_wait_data(sk, &timeo);
 808
 809                 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
 810                         net_dbg_ratelimited("LLC(%s:%d): Application bug, race in MSG_PEEK\n",
 811                                             current->comm,
 812                                             task_pid_nr(current));
 813                         peek_seq = llc->copied_seq;
 814                 }
 815                 continue;
 816         found_ok_skb:
 817                 /* Ok so how much can we use? */
 818                 used = skb->len - offset;
 819                 if (len < used)
 820                         used = len;
 821
 822                 if (!(flags & MSG_TRUNC)) {
 823                         int rc = skb_copy_datagram_iovec(skb, offset,
 824                                                          msg->msg_iov, used);
 825                         if (rc) {
 826                                 /* Exception. Bailout! */
 827                                 if (!copied)
 828                                         copied = -EFAULT;
 829                                 break;
 830                         }
 831                 }
 832
 833                 *seq += used;
 834                 copied += used;
 835                 len -= used;
 836
 837                 /* For non stream protcols we get one packet per recvmsg call */
 838                 if (sk->sk_type != SOCK_STREAM)
 839                         goto copy_uaddr;
 840
 841                 if (!(flags & MSG_PEEK)) {
 842                         spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
 843                         sk_eat_skb(sk, skb, false);
 844                         spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
 845                         *seq = 0;
 846                 }
 847
 848                 /* Partial read */
 849                 if (used + offset < skb->len)
 850                         continue;
 851         } while (len > 0);
 852
 853 out:
 854         release_sock(sk);
 855         return copied;
 856 copy_uaddr:
 857         if (uaddr != NULL && skb != NULL) {
 858                 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 859                 msg->msg_namelen = sizeof(*uaddr);
 860         }
 861         if (llc_sk(sk)->cmsg_flags)
 862                 llc_cmsg_rcv(msg, skb);
 863
 864         if (!(flags & MSG_PEEK)) {
 865                         spin_lock_irqsave(&sk->sk_receive_queue.lock, cpu_flags);
 866                         sk_eat_skb(sk, skb, false);
 867                         spin_unlock_irqrestore(&sk->sk_receive_queue.lock, cpu_flags);
 868                         *seq = 0;
 869         }
 870
 871         goto out;
 872 }
 873
 874 /**
 875  *      llc_ui_sendmsg - Transmit data provided by the socket user.
 876  *      @sock: Socket to transmit data from.
 877  *      @msg: Various user related information.
 878  *      @len: Length of data to transmit.
 879  *
 880  *      Transmit data provided by the socket user.
 881  *      Returns non-negative upon success, negative otherwise.
 882  */
 883 static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock,
 884                           struct msghdr *msg, size_t len)
 885 {
 886         struct sock *sk = sock->sk;
 887         struct llc_sock *llc = llc_sk(sk);
 888         struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name;
 889         int flags = msg->msg_flags;
 890         int noblock = flags & MSG_DONTWAIT;
 891         struct sk_buff *skb;
 892         size_t size = 0;
 893         int rc = -EINVAL, copied = 0, hdrlen;
 894
 895         dprintk("%s: sending from %02X to %02X\n", __func__,
 896                 llc->laddr.lsap, llc->daddr.lsap);
 897         lock_sock(sk);
 898         if (addr) {
 899                 if (msg->msg_namelen < sizeof(*addr))
 900                         goto release;
 901         } else {
 902                 if (llc_ui_addr_null(&llc->addr))
 903                         goto release;
 904                 addr = &llc->addr;
 905         }
 906         /* must bind connection to sap if user hasn't done it. */
 907         if (sock_flag(sk, SOCK_ZAPPED)) {
 908                 /* bind to sap with null dev, exclusive. */
 909                 rc = llc_ui_autobind(sock, addr);
 910                 if (rc)
 911                         goto release;
 912         }
 913         hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
 914         size = hdrlen + len;
 915         if (size > llc->dev->mtu)
 916                 size = llc->dev->mtu;
 917         copied = size - hdrlen;
 918         release_sock(sk);
 919         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 920         lock_sock(sk);
 921         if (!skb)
 922                 goto release;
 923         skb->dev      = llc->dev;
 924         skb->protocol = llc_proto_type(addr->sllc_arphrd);
 925         skb_reserve(skb, hdrlen);
 926         rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied);
 927         if (rc)
 928                 goto out;
 929         if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
 930                 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
 931                                           addr->sllc_sap);
 932                 goto out;
 933         }
 934         if (addr->sllc_test) {
 935                 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
 936                                             addr->sllc_sap);
 937                 goto out;
 938         }
 939         if (addr->sllc_xid) {
 940                 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
 941                                            addr->sllc_sap);
 942                 goto out;
 943         }
 944         rc = -ENOPROTOOPT;
 945         if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
 946                 goto out;
 947         rc = llc_ui_send_data(sk, skb, noblock);
 948 out:
 949         if (rc) {
 950                 kfree_skb(skb);
 951 release:
 952                 dprintk("%s: failed sending from %02X to %02X: %d\n",
 953                         __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
 954         }
 955         release_sock(sk);
 956         return rc ? : copied;
 957 }
 958
 959 /**
 960  *      llc_ui_getname - return the address info of a socket
 961  *      @sock: Socket to get address of.
 962  *      @uaddr: Address structure to return information.
 963  *      @uaddrlen: Length of address structure.
 964  *      @peer: Does user want local or remote address information.
 965  *
 966  *      Return the address information of a socket.
 967  */
 968 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
 969                           int *uaddrlen, int peer)
 970 {
 971         struct sockaddr_llc sllc;
 972         struct sock *sk = sock->sk;
 973         struct llc_sock *llc = llc_sk(sk);
 974         int rc = -EBADF;
 975
 976         memset(&sllc, 0, sizeof(sllc));
 977         lock_sock(sk);
 978         if (sock_flag(sk, SOCK_ZAPPED))
 979                 goto out;
 980         *uaddrlen = sizeof(sllc);
 981         if (peer) {
 982                 rc = -ENOTCONN;
 983                 if (sk->sk_state != TCP_ESTABLISHED)
 984                         goto out;
 985                 if(llc->dev)
 986                         sllc.sllc_arphrd = llc->dev->type;
 987                 sllc.sllc_sap = llc->daddr.lsap;
 988                 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
 989         } else {
 990                 rc = -EINVAL;
 991                 if (!llc->sap)
 992                         goto out;
 993                 sllc.sllc_sap = llc->sap->laddr.lsap;
 994
 995                 if (llc->dev) {
 996                         sllc.sllc_arphrd = llc->dev->type;
 997                         memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
 998                                IFHWADDRLEN);
 999                 }
1000         }
1001         rc = 0;
1002         sllc.sllc_family = AF_LLC;
1003         memcpy(uaddr, &sllc, sizeof(sllc));
1004 out:
1005         release_sock(sk);
1006         return rc;
1007 }
1008
1009 /**
1010  *      llc_ui_ioctl - io controls for PF_LLC
1011  *      @sock: Socket to get/set info
1012  *      @cmd: command
1013  *      @arg: optional argument for cmd
1014  *
1015  *      get/set info on llc sockets
1016  */
1017 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1018                         unsigned long arg)
1019 {
1020         return -ENOIOCTLCMD;
1021 }
1022
1023 /**
1024  *      llc_ui_setsockopt - set various connection specific parameters.
1025  *      @sock: Socket to set options on.
1026  *      @level: Socket level user is requesting operations on.
1027  *      @optname: Operation name.
1028  *      @optval: User provided operation data.
1029  *      @optlen: Length of optval.
1030  *
1031  *      Set various connection specific parameters.
1032  */
1033 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1034                              char __user *optval, unsigned int optlen)
1035 {
1036         struct sock *sk = sock->sk;
1037         struct llc_sock *llc = llc_sk(sk);
1038         unsigned int opt;
1039         int rc = -EINVAL;
1040
1041         lock_sock(sk);
1042         if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1043                 goto out;
1044         rc = get_user(opt, (int __user *)optval);
1045         if (rc)
1046                 goto out;
1047         rc = -EINVAL;
1048         switch (optname) {
1049         case LLC_OPT_RETRY:
1050                 if (opt > LLC_OPT_MAX_RETRY)
1051                         goto out;
1052                 llc->n2 = opt;
1053                 break;
1054         case LLC_OPT_SIZE:
1055                 if (opt > LLC_OPT_MAX_SIZE)
1056                         goto out;
1057                 llc->n1 = opt;
1058                 break;
1059         case LLC_OPT_ACK_TMR_EXP:
1060                 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1061                         goto out;
1062                 llc->ack_timer.expire = opt * HZ;
1063                 break;
1064         case LLC_OPT_P_TMR_EXP:
1065                 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1066                         goto out;
1067                 llc->pf_cycle_timer.expire = opt * HZ;
1068                 break;
1069         case LLC_OPT_REJ_TMR_EXP:
1070                 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1071                         goto out;
1072                 llc->rej_sent_timer.expire = opt * HZ;
1073                 break;
1074         case LLC_OPT_BUSY_TMR_EXP:
1075                 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1076                         goto out;
1077                 llc->busy_state_timer.expire = opt * HZ;
1078                 break;
1079         case LLC_OPT_TX_WIN:
1080                 if (opt > LLC_OPT_MAX_WIN)
1081                         goto out;
1082                 llc->k = opt;
1083                 break;
1084         case LLC_OPT_RX_WIN:
1085                 if (opt > LLC_OPT_MAX_WIN)
1086                         goto out;
1087                 llc->rw = opt;
1088                 break;
1089         case LLC_OPT_PKTINFO:
1090                 if (opt)
1091                         llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1092                 else
1093                         llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1094                 break;
1095         default:
1096                 rc = -ENOPROTOOPT;
1097                 goto out;
1098         }
1099         rc = 0;
1100 out:
1101         release_sock(sk);
1102         return rc;
1103 }
1104
1105 /**
1106  *      llc_ui_getsockopt - get connection specific socket info
1107  *      @sock: Socket to get information from.
1108  *      @level: Socket level user is requesting operations on.
1109  *      @optname: Operation name.
1110  *      @optval: Variable to return operation data in.
1111  *      @optlen: Length of optval.
1112  *
1113  *      Get connection specific socket information.
1114  */
1115 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1116                              char __user *optval, int __user *optlen)
1117 {
1118         struct sock *sk = sock->sk;
1119         struct llc_sock *llc = llc_sk(sk);
1120         int val = 0, len = 0, rc = -EINVAL;
1121
1122         lock_sock(sk);
1123         if (unlikely(level != SOL_LLC))
1124                 goto out;
1125         rc = get_user(len, optlen);
1126         if (rc)
1127                 goto out;
1128         rc = -EINVAL;
1129         if (len != sizeof(int))
1130                 goto out;
1131         switch (optname) {
1132         case LLC_OPT_RETRY:
1133                 val = llc->n2;                                  break;
1134         case LLC_OPT_SIZE:
1135                 val = llc->n1;                                  break;
1136         case LLC_OPT_ACK_TMR_EXP:
1137                 val = llc->ack_timer.expire / HZ;               break;
1138         case LLC_OPT_P_TMR_EXP:
1139                 val = llc->pf_cycle_timer.expire / HZ;          break;
1140         case LLC_OPT_REJ_TMR_EXP:
1141                 val = llc->rej_sent_timer.expire / HZ;          break;
1142         case LLC_OPT_BUSY_TMR_EXP:
1143                 val = llc->busy_state_timer.expire / HZ;        break;
1144         case LLC_OPT_TX_WIN:
1145                 val = llc->k;                           break;
1146         case LLC_OPT_RX_WIN:
1147                 val = llc->rw;                          break;
1148         case LLC_OPT_PKTINFO:
1149                 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1150                 break;
1151         default:
1152                 rc = -ENOPROTOOPT;
1153                 goto out;
1154         }
1155         rc = 0;
1156         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1157                 rc = -EFAULT;
1158 out:
1159         release_sock(sk);
1160         return rc;
1161 }
1162
1163 static const struct net_proto_family llc_ui_family_ops = {
1164         .family = PF_LLC,
1165         .create = llc_ui_create,
1166         .owner  = THIS_MODULE,
1167 };
1168
1169 static const struct proto_ops llc_ui_ops = {
1170         .family      = PF_LLC,
1171         .owner       = THIS_MODULE,
1172         .release     = llc_ui_release,
1173         .bind        = llc_ui_bind,
1174         .connect     = llc_ui_connect,
1175         .socketpair  = sock_no_socketpair,
1176         .accept      = llc_ui_accept,
1177         .getname     = llc_ui_getname,
1178         .poll        = datagram_poll,
1179         .ioctl       = llc_ui_ioctl,
1180         .listen      = llc_ui_listen,
1181         .shutdown    = llc_ui_shutdown,
1182         .setsockopt  = llc_ui_setsockopt,
1183         .getsockopt  = llc_ui_getsockopt,
1184         .sendmsg     = llc_ui_sendmsg,
1185         .recvmsg     = llc_ui_recvmsg,
1186         .mmap        = sock_no_mmap,
1187         .sendpage    = sock_no_sendpage,
1188 };
1189
1190 static const char llc_proc_err_msg[] __initconst =
1191         KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1192 static const char llc_sysctl_err_msg[] __initconst =
1193         KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1194 static const char llc_sock_err_msg[] __initconst =
1195         KERN_CRIT "LLC: Unable to register the network family\n";
1196
1197 static int __init llc2_init(void)
1198 {
1199         int rc = proto_register(&llc_proto, 0);
1200
1201         if (rc != 0)
1202                 goto out;
1203
1204         llc_build_offset_table();
1205         llc_station_init();
1206         llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1207         rc = llc_proc_init();
1208         if (rc != 0) {
1209                 printk(llc_proc_err_msg);
1210                 goto out_station;
1211         }
1212         rc = llc_sysctl_init();
1213         if (rc) {
1214                 printk(llc_sysctl_err_msg);
1215                 goto out_proc;
1216         }
1217         rc = sock_register(&llc_ui_family_ops);
1218         if (rc) {
1219                 printk(llc_sock_err_msg);
1220                 goto out_sysctl;
1221         }
1222         llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1223         llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1224 out:
1225         return rc;
1226 out_sysctl:
1227         llc_sysctl_exit();
1228 out_proc:
1229         llc_proc_exit();
1230 out_station:
1231         llc_station_exit();
1232         proto_unregister(&llc_proto);
1233         goto out;
1234 }
1235
1236 static void __exit llc2_exit(void)
1237 {
1238         llc_station_exit();
1239         llc_remove_pack(LLC_DEST_SAP);
1240         llc_remove_pack(LLC_DEST_CONN);
1241         sock_unregister(PF_LLC);
1242         llc_proc_exit();
1243         llc_sysctl_exit();
1244         proto_unregister(&llc_proto);
1245 }
1246
1247 module_init(llc2_init);
1248 module_exit(llc2_exit);
1249
1250 MODULE_LICENSE("GPL");
1251 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1252 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1253 MODULE_ALIAS_NETPROTO(PF_LLC);