net/llc/af_llc.c

   1 /*
   2  * af_llc.c - LLC User Interface SAPs
   3  * Description:
   4  *   Functions in this module are implementation of socket based llc
   5  *   communications for the Linux operating system. Support of llc class
   6  *   one and class two is provided via SOCK_DGRAM and SOCK_STREAM
   7  *   respectively.
   8  *
   9  *   An llc2 connection is (mac + sap), only one llc2 sap connection
  10  *   is allowed per mac. Though one sap may have multiple mac + sap
  11  *   connections.
  12  *
  13  * Copyright (c) 2001 by Jay Schulist <jschlst@samba.org>
  14  *               2002-2003 by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  15  *
  16  * This program can be redistributed or modified under the terms of the
  17  * GNU General Public License as published by the Free Software Foundation.
  18  * This program is distributed without any warranty or implied warranty
  19  * of merchantability or fitness for a particular purpose.
  20  *
  21  * See the GNU General Public License for more details.
  22  */
  23 #include <linux/config.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/tcp.h>
  27 #include <linux/rtnetlink.h>
  28 #include <linux/init.h>
  29 #include <net/llc.h>
  30 #include <net/llc_sap.h>
  31 #include <net/llc_pdu.h>
  32 #include <net/llc_conn.h>
  33
  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 struct proto_ops llc_ui_ops;
  39
  40 static int llc_ui_wait_for_conn(struct sock *sk, int timeout);
  41 static int llc_ui_wait_for_disc(struct sock *sk, int timeout);
  42 static int llc_ui_wait_for_data(struct sock *sk, int timeout);
  43 static int llc_ui_wait_for_busy_core(struct sock *sk, int timeout);
  44
  45 #if 0
  46 #define dprintk(args...) printk(KERN_DEBUG args)
  47 #else
  48 #define dprintk(args...)
  49 #endif
  50
  51 /**
  52  *      llc_ui_next_link_no - return the next unused link number for a sap
  53  *      @sap: Address of sap to get link number from.
  54  *
  55  *      Return the next unused link number for a given sap.
  56  */
  57 static __inline__ u16 llc_ui_next_link_no(int sap)
  58 {
  59         return llc_ui_sap_link_no_max[sap]++;
  60 }
  61
  62 /**
  63  *      llc_proto_type - return eth protocol for ARP header type
  64  *      @arphrd: ARP header type.
  65  *
  66  *      Given an ARP header type return the corresponding ethernet protocol.
  67  */
  68 static __inline__ u16 llc_proto_type(u16 arphrd)
  69 {
  70         return arphrd == ARPHRD_IEEE802_TR ?
  71                          htons(ETH_P_TR_802_2) : htons(ETH_P_802_2);
  72 }
  73
  74 /**
  75  *      llc_ui_addr_null - determines if a address structure is null
  76  *      @addr: Address to test if null.
  77  */
  78 static __inline__ u8 llc_ui_addr_null(struct sockaddr_llc *addr)
  79 {
  80         return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
  81 }
  82
  83 /**
  84  *      llc_ui_header_len - return length of llc header based on operation
  85  *      @sk: Socket which contains a valid llc socket type.
  86  *      @addr: Complete sockaddr_llc structure received from the user.
  87  *
  88  *      Provide the length of the llc header depending on what kind of
  89  *      operation the user would like to perform and the type of socket.
  90  *      Returns the correct llc header length.
  91  */
  92 static __inline__ u8 llc_ui_header_len(struct sock *sk,
  93                                        struct sockaddr_llc *addr)
  94 {
  95         u8 rc = LLC_PDU_LEN_U;
  96
  97         if (addr->sllc_test || addr->sllc_xid)
  98                 rc = LLC_PDU_LEN_U;
  99         else if (sk->sk_type == SOCK_STREAM)
 100                 rc = LLC_PDU_LEN_I;
 101         return rc;
 102 }
 103
 104 /**
 105  *      llc_ui_send_data - send data via reliable llc2 connection
 106  *      @sk: Connection the socket is using.
 107  *      @skb: Data the user wishes to send.
 108  *      @addr: Source and destination fields provided by the user.
 109  *      @noblock: can we block waiting for data?
 110  *
 111  *      Send data via reliable llc2 connection.
 112  *      Returns 0 upon success, non-zero if action did not succeed.
 113  */
 114 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 115 {
 116         struct llc_sock* llc = llc_sk(sk);
 117         int rc = 0;
 118
 119         if (llc_data_accept_state(llc->state) || llc->p_flag) {
 120                 int timeout = sock_sndtimeo(sk, noblock);
 121
 122                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 123         }
 124         if (!rc)
 125                 rc = llc_build_and_send_pkt(sk, skb);
 126         return rc;
 127 }
 128
 129 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 130 {
 131         sk->sk_type     = sock->type;
 132         sk->sk_sleep    = &sock->wait;
 133         sk->sk_socket   = sock;
 134         sock->sk        = sk;
 135         sock->ops       = &llc_ui_ops;
 136 }
 137
 138 static struct proto llc_proto = {
 139         .name     = "DDP",
 140         .owner    = THIS_MODULE,
 141         .obj_size = sizeof(struct llc_sock),
 142 };
 143
 144 /**
 145  *      llc_ui_create - alloc and init a new llc_ui socket
 146  *      @sock: Socket to initialize and attach allocated sk to.
 147  *      @protocol: Unused.
 148  *
 149  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 150  *      socket type we have available.
 151  *      Returns 0 upon success, negative upon failure.
 152  */
 153 static int llc_ui_create(struct socket *sock, int protocol)
 154 {
 155         struct sock *sk;
 156         int rc = -ESOCKTNOSUPPORT;
 157
 158         if (sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM) {
 159                 rc = -ENOMEM;
 160                 sk = llc_sk_alloc(PF_LLC, GFP_KERNEL, &llc_proto);
 161                 if (sk) {
 162                         rc = 0;
 163                         llc_ui_sk_init(sock, sk);
 164                 }
 165         }
 166         return rc;
 167 }
 168
 169 /**
 170  *      llc_ui_release - shutdown socket
 171  *      @sock: Socket to release.
 172  *
 173  *      Shutdown and deallocate an existing socket.
 174  */
 175 static int llc_ui_release(struct socket *sock)
 176 {
 177         struct sock *sk = sock->sk;
 178         struct llc_sock *llc;
 179
 180         if (!sk)
 181                 goto out;
 182         sock_hold(sk);
 183         lock_sock(sk);
 184         llc = llc_sk(sk);
 185         dprintk("%s: closing local(%02X) remote(%02X)\n", __FUNCTION__,
 186                 llc->laddr.lsap, llc->daddr.lsap);
 187         if (!llc_send_disc(sk))
 188                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 189         if (!sock_flag(sk, SOCK_ZAPPED))
 190                 llc_sap_remove_socket(llc->sap, sk);
 191         release_sock(sk);
 192         if (llc->sap && hlist_empty(&llc->sap->sk_list.list)) {
 193                 llc_release_sockets(llc->sap);
 194                 llc_sap_close(llc->sap);
 195         }
 196         if (llc->dev)
 197                 dev_put(llc->dev);
 198         sock_put(sk);
 199         llc_sk_free(sk);
 200 out:
 201         return 0;
 202 }
 203
 204 /**
 205  *      llc_ui_autoport - provide dynamically allocate SAP number
 206  *
 207  *      Provide the caller with a dynamically allocated SAP number according
 208  *      to the rules that are set in this function. Returns: 0, upon failure,
 209  *      SAP number otherwise.
 210  */
 211 static int llc_ui_autoport(void)
 212 {
 213         struct llc_sap *sap;
 214         int i, tries = 0;
 215
 216         while (tries < LLC_SAP_DYN_TRIES) {
 217                 for (i = llc_ui_sap_last_autoport;
 218                      i < LLC_SAP_DYN_STOP; i += 2) {
 219                         sap = llc_sap_find(i);
 220                         if (!sap) {
 221                                 llc_ui_sap_last_autoport = i + 2;
 222                                 goto out;
 223                         }
 224                 }
 225                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 226                 tries++;
 227         }
 228         i = 0;
 229 out:
 230         return i;
 231 }
 232
 233 /**
 234  *      llc_ui_autobind - Bind a socket to a specific address.
 235  *      @sk: Socket to bind an address to.
 236  *      @addr: Address the user wants the socket bound to.
 237  *
 238  *      Bind a socket to a specific address. For llc a user is able to bind to
 239  *      a specific sap only or mac + sap. If the user only specifies a sap and
 240  *      a null dmac (all zeros) the user is attempting to bind to an entire
 241  *      sap. This will stop anyone else on the local system from using that
 242  *      sap.  If someone else has a mac + sap open the bind to null + sap will
 243  *      fail.
 244  *      If the user desires to bind to a specific mac + sap, it is possible to
 245  *      have multiple sap connections via multiple macs.
 246  *      Bind and autobind for that matter must enforce the correct sap usage
 247  *      otherwise all hell will break loose.
 248  *      Returns: 0 upon success, negative otherwise.
 249  */
 250 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 251 {
 252         struct sock *sk = sock->sk;
 253         struct llc_sock *llc = llc_sk(sk);
 254         struct llc_sap *sap;
 255         int rc = -EINVAL;
 256
 257         if (!sock_flag(sk, SOCK_ZAPPED))
 258                 goto out;
 259         rc = -ENODEV;
 260         llc->dev = dev_getfirstbyhwtype(addr->sllc_arphrd);
 261         if (!llc->dev)
 262                 goto out;
 263         rc = -EUSERS;
 264         llc->laddr.lsap = llc_ui_autoport();
 265         if (!llc->laddr.lsap)
 266                 goto out;
 267         rc = -EBUSY; /* some other network layer is using the sap */
 268         sap = llc_sap_open(llc->laddr.lsap, NULL);
 269         if (!sap)
 270                 goto out;
 271         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 272         memcpy(&llc->addr, addr, sizeof(llc->addr));
 273         /* assign new connection to its SAP */
 274         llc_sap_add_socket(sap, sk);
 275         sock_reset_flag(sk, SOCK_ZAPPED);
 276         rc = 0;
 277 out:
 278         return rc;
 279 }
 280
 281 /**
 282  *      llc_ui_bind - bind a socket to a specific address.
 283  *      @sock: Socket to bind an address to.
 284  *      @uaddr: Address the user wants the socket bound to.
 285  *      @addrlen: Length of the uaddr structure.
 286  *
 287  *      Bind a socket to a specific address. For llc a user is able to bind to
 288  *      a specific sap only or mac + sap. If the user only specifies a sap and
 289  *      a null dmac (all zeros) the user is attempting to bind to an entire
 290  *      sap. This will stop anyone else on the local system from using that
 291  *      sap. If someone else has a mac + sap open the bind to null + sap will
 292  *      fail.
 293  *      If the user desires to bind to a specific mac + sap, it is possible to
 294  *      have multiple sap connections via multiple macs.
 295  *      Bind and autobind for that matter must enforce the correct sap usage
 296  *      otherwise all hell will break loose.
 297  *      Returns: 0 upon success, negative otherwise.
 298  */
 299 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 300 {
 301         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 302         struct sock *sk = sock->sk;
 303         struct llc_sock *llc = llc_sk(sk);
 304         struct llc_sap *sap;
 305         int rc = -EINVAL;
 306
 307         dprintk("%s: binding %02X\n", __FUNCTION__, addr->sllc_sap);
 308         if (!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))
 309                 goto out;
 310         rc = -EAFNOSUPPORT;
 311         if (addr->sllc_family != AF_LLC)
 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         } else {
 326                 struct llc_addr laddr, daddr;
 327                 struct sock *ask;
 328
 329                 memset(&laddr, 0, sizeof(laddr));
 330                 memset(&daddr, 0, sizeof(daddr));
 331                 /*
 332                  * FIXME: check if the the address is multicast,
 333                  *        only SOCK_DGRAM can do this.
 334                  */
 335                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 336                 laddr.lsap = addr->sllc_sap;
 337                 rc = -EADDRINUSE; /* mac + sap clash. */
 338                 ask = llc_lookup_established(sap, &daddr, &laddr);
 339                 if (ask) {
 340                         sock_put(ask);
 341                         goto out;
 342                 }
 343         }
 344         llc->laddr.lsap = addr->sllc_sap;
 345         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 346         memcpy(&llc->addr, addr, sizeof(llc->addr));
 347         /* assign new connection to its SAP */
 348         llc_sap_add_socket(sap, sk);
 349         sock_reset_flag(sk, SOCK_ZAPPED);
 350         rc = 0;
 351 out:
 352         return rc;
 353 }
 354
 355 /**
 356  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 357  *      @sock: Socket to shutdown.
 358  *      @how: What part of the socket to shutdown.
 359  *
 360  *      Shutdown a connected llc2 socket. Currently this function only supports
 361  *      shutting down both sends and receives (2), we could probably make this
 362  *      function such that a user can shutdown only half the connection but not
 363  *      right now.
 364  *      Returns: 0 upon success, negative otherwise.
 365  */
 366 static int llc_ui_shutdown(struct socket *sock, int how)
 367 {
 368         struct sock *sk = sock->sk;
 369         int rc = -ENOTCONN;
 370
 371         lock_sock(sk);
 372         if (sk->sk_state != TCP_ESTABLISHED)
 373                 goto out;
 374         rc = -EINVAL;
 375         if (how != 2)
 376                 goto out;
 377         rc = llc_send_disc(sk);
 378         if (!rc)
 379                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 380         /* Wake up anyone sleeping in poll */
 381         sk->sk_state_change(sk);
 382 out:
 383         release_sock(sk);
 384         return rc;
 385 }
 386
 387 /**
 388  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 389  *      @sock: Socket which will be connected to the remote destination.
 390  *      @uaddr: Remote and possibly the local address of the new connection.
 391  *      @addrlen: Size of uaddr structure.
 392  *      @flags: Operational flags specified by the user.
 393  *
 394  *      Connect to a remote llc2 mac + sap. The caller must specify the
 395  *      destination mac and address to connect to. If the user hasn't previously
 396  *      called bind(2) with a smac the address of the first interface of the
 397  *      specified arp type will be used.
 398  *      This function will autobind if user did not previously call bind.
 399  *      Returns: 0 upon success, negative otherwise.
 400  */
 401 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 402                           int addrlen, int flags)
 403 {
 404         struct sock *sk = sock->sk;
 405         struct llc_sock *llc = llc_sk(sk);
 406         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 407         struct net_device *dev;
 408         int rc = -EINVAL;
 409
 410         lock_sock(sk);
 411         if (addrlen != sizeof(*addr))
 412                 goto out;
 413         rc = -EAFNOSUPPORT;
 414         if (addr->sllc_family != AF_LLC)
 415                 goto out;
 416         /* bind connection to sap if user hasn't done it. */
 417         if (sock_flag(sk, SOCK_ZAPPED)) {
 418                 /* bind to sap with null dev, exclusive */
 419                 rc = llc_ui_autobind(sock, addr);
 420                 if (rc)
 421                         goto out;
 422                 llc->daddr.lsap = addr->sllc_sap;
 423                 memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 424         }
 425         dev = llc->dev;
 426         if (sk->sk_type != SOCK_STREAM)
 427                 goto out;
 428         rc = -EALREADY;
 429         if (sock->state == SS_CONNECTING)
 430                 goto out;
 431         sock->state = SS_CONNECTING;
 432         sk->sk_state   = TCP_SYN_SENT;
 433         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 434         rc = llc_establish_connection(sk, dev->dev_addr,
 435                                       addr->sllc_mac, addr->sllc_sap);
 436         if (rc) {
 437                 dprintk("%s: llc_ui_send_conn failed :-(\n", __FUNCTION__);
 438                 sock->state  = SS_UNCONNECTED;
 439                 sk->sk_state = TCP_CLOSE;
 440                 goto out;
 441         }
 442         rc = llc_ui_wait_for_conn(sk, sk->sk_rcvtimeo);
 443         if (rc)
 444                 dprintk("%s: llc_ui_wait_for_conn failed=%d\n", __FUNCTION__, rc);
 445 out:
 446         release_sock(sk);
 447         return rc;
 448 }
 449
 450 /**
 451  *      llc_ui_listen - allow a normal socket to accept incoming connections
 452  *      @sock: Socket to allow incoming connections on.
 453  *      @backlog: Number of connections to queue.
 454  *
 455  *      Allow a normal socket to accept incoming connections.
 456  *      Returns 0 upon success, negative otherwise.
 457  */
 458 static int llc_ui_listen(struct socket *sock, int backlog)
 459 {
 460         struct sock *sk = sock->sk;
 461         int rc = -EINVAL;
 462
 463         lock_sock(sk);
 464         if (sock->state != SS_UNCONNECTED)
 465                 goto out;
 466         rc = -EOPNOTSUPP;
 467         if (sk->sk_type != SOCK_STREAM)
 468                 goto out;
 469         rc = -EAGAIN;
 470         if (sock_flag(sk, SOCK_ZAPPED))
 471                 goto out;
 472         rc = 0;
 473         if (!(unsigned)backlog) /* BSDism */
 474                 backlog = 1;
 475         sk->sk_max_ack_backlog = backlog;
 476         if (sk->sk_state != TCP_LISTEN) {
 477                 sk->sk_ack_backlog = 0;
 478                 sk->sk_state       = TCP_LISTEN;
 479         }
 480         sk->sk_socket->flags |= __SO_ACCEPTCON;
 481 out:
 482         release_sock(sk);
 483         return rc;
 484 }
 485
 486 static int llc_ui_wait_for_disc(struct sock *sk, int timeout)
 487 {
 488         DECLARE_WAITQUEUE(wait, current);
 489         int rc;
 490
 491         add_wait_queue_exclusive(sk->sk_sleep, &wait);
 492         for (;;) {
 493                 __set_current_state(TASK_INTERRUPTIBLE);
 494                 rc = 0;
 495                 if (sk->sk_state != TCP_CLOSE) {
 496                         release_sock(sk);
 497                         timeout = schedule_timeout(timeout);
 498                         lock_sock(sk);
 499                 } else
 500                         break;
 501                 rc = -ERESTARTSYS;
 502                 if (signal_pending(current))
 503                         break;
 504                 rc = -EAGAIN;
 505                 if (!timeout)
 506                         break;
 507         }
 508         __set_current_state(TASK_RUNNING);
 509         remove_wait_queue(sk->sk_sleep, &wait);
 510         return rc;
 511 }
 512
 513 static int llc_ui_wait_for_conn(struct sock *sk, int timeout)
 514 {
 515         DECLARE_WAITQUEUE(wait, current);
 516         int rc;
 517
 518         add_wait_queue_exclusive(sk->sk_sleep, &wait);
 519         for (;;) {
 520                 __set_current_state(TASK_INTERRUPTIBLE);
 521                 rc = -EAGAIN;
 522                 if (sk->sk_state == TCP_CLOSE)
 523                         break;
 524                 rc = 0;
 525                 if (sk->sk_state != TCP_ESTABLISHED) {
 526                         release_sock(sk);
 527                         timeout = schedule_timeout(timeout);
 528                         lock_sock(sk);
 529                 } else
 530                         break;
 531                 rc = -ERESTARTSYS;
 532                 if (signal_pending(current))
 533                         break;
 534                 rc = -EAGAIN;
 535                 if (!timeout)
 536                         break;
 537         }
 538         __set_current_state(TASK_RUNNING);
 539         remove_wait_queue(sk->sk_sleep, &wait);
 540         return rc;
 541 }
 542
 543 static int llc_ui_wait_for_data(struct sock *sk, int timeout)
 544 {
 545         DECLARE_WAITQUEUE(wait, current);
 546         int rc = 0;
 547
 548         add_wait_queue_exclusive(sk->sk_sleep, &wait);
 549         for (;;) {
 550                 __set_current_state(TASK_INTERRUPTIBLE);
 551                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 552                         break;
 553                 /*
 554                  * Well, if we have backlog, try to process it now.
 555                  */
 556                 if (sk->sk_backlog.tail) {
 557                         release_sock(sk);
 558                         lock_sock(sk);
 559                 }
 560                 rc = 0;
 561                 if (skb_queue_empty(&sk->sk_receive_queue)) {
 562                         release_sock(sk);
 563                         timeout = schedule_timeout(timeout);
 564                         lock_sock(sk);
 565                 } else
 566                         break;
 567                 rc = -ERESTARTSYS;
 568                 if (signal_pending(current))
 569                         break;
 570                 rc = -EAGAIN;
 571                 if (!timeout)
 572                         break;
 573         }
 574         __set_current_state(TASK_RUNNING);
 575         remove_wait_queue(sk->sk_sleep, &wait);
 576         return rc;
 577 }
 578
 579 static int llc_ui_wait_for_busy_core(struct sock *sk, int timeout)
 580 {
 581         DECLARE_WAITQUEUE(wait, current);
 582         struct llc_sock *llc = llc_sk(sk);
 583         int rc;
 584
 585         add_wait_queue_exclusive(sk->sk_sleep, &wait);
 586         for (;;) {
 587                 dprintk("%s: looping...\n", __FUNCTION__);
 588                 __set_current_state(TASK_INTERRUPTIBLE);
 589                 rc = -ENOTCONN;
 590                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 591                         break;
 592                 rc = 0;
 593                 if (llc_data_accept_state(llc->state) || llc->p_flag) {
 594                         release_sock(sk);
 595                         timeout = schedule_timeout(timeout);
 596                         lock_sock(sk);
 597                 } else
 598                         break;
 599                 rc = -ERESTARTSYS;
 600                 if (signal_pending(current))
 601                         break;
 602                 rc = -EAGAIN;
 603                 if (!timeout)
 604                         break;
 605         }
 606         __set_current_state(TASK_RUNNING);
 607         remove_wait_queue(sk->sk_sleep, &wait);
 608         return rc;
 609 }
 610
 611 /**
 612  *      llc_ui_accept - accept a new incoming connection.
 613  *      @sock: Socket which connections arrive on.
 614  *      @newsock: Socket to move incoming connection to.
 615  *      @flags: User specified operational flags.
 616  *
 617  *      Accept a new incoming connection.
 618  *      Returns 0 upon success, negative otherwise.
 619  */
 620 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 621 {
 622         struct sock *sk = sock->sk, *newsk;
 623         struct llc_sock *llc, *newllc;
 624         struct sk_buff *skb;
 625         int rc = -EOPNOTSUPP;
 626
 627         dprintk("%s: accepting on %02X\n", __FUNCTION__,
 628                 llc_sk(sk)->laddr.lsap);
 629         lock_sock(sk);
 630         if (sk->sk_type != SOCK_STREAM)
 631                 goto out;
 632         rc = -EINVAL;
 633         if (sock->state != SS_UNCONNECTED || sk->sk_state != TCP_LISTEN)
 634                 goto out;
 635         /* wait for a connection to arrive. */
 636         rc = llc_ui_wait_for_data(sk, sk->sk_rcvtimeo);
 637         if (rc)
 638                 goto out;
 639         dprintk("%s: got a new connection on %02X\n", __FUNCTION__,
 640                 llc_sk(sk)->laddr.lsap);
 641         skb = skb_dequeue(&sk->sk_receive_queue);
 642         rc = -EINVAL;
 643         if (!skb->sk)
 644                 goto frees;
 645         rc = 0;
 646         newsk = skb->sk;
 647         /* attach connection to a new socket. */
 648         llc_ui_sk_init(newsock, newsk);
 649         sock_reset_flag(newsk, SOCK_ZAPPED);
 650         newsk->sk_state         = TCP_ESTABLISHED;
 651         newsock->state          = SS_CONNECTED;
 652         llc                     = llc_sk(sk);
 653         newllc                  = llc_sk(newsk);
 654         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 655         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 656
 657         /* put original socket back into a clean listen state. */
 658         sk->sk_state = TCP_LISTEN;
 659         sk->sk_ack_backlog--;
 660         skb->sk = NULL;
 661         dprintk("%s: ok success on %02X, client on %02X\n", __FUNCTION__,
 662                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 663 frees:
 664         kfree_skb(skb);
 665 out:
 666         release_sock(sk);
 667         return rc;
 668 }
 669
 670 /**
 671  *      llc_ui_recvmsg - copy received data to the socket user.
 672  *      @sock: Socket to copy data from.
 673  *      @msg: Various user space related information.
 674  *      @size: Size of user buffer.
 675  *      @flags: User specified flags.
 676  *
 677  *      Copy received data to the socket user.
 678  *      Returns non-negative upon success, negative otherwise.
 679  */
 680 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 681                           struct msghdr *msg, size_t size, int flags)
 682 {
 683         struct sock *sk = sock->sk;
 684         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 685         struct sk_buff *skb;
 686         size_t copied = 0;
 687         int rc = -ENOMEM, timeout;
 688         int noblock = flags & MSG_DONTWAIT;
 689
 690         dprintk("%s: receiving in %02X from %02X\n", __FUNCTION__,
 691                 llc_sk(sk)->laddr.lsap, llc_sk(sk)->daddr.lsap);
 692         lock_sock(sk);
 693         timeout = sock_rcvtimeo(sk, noblock);
 694         rc = llc_ui_wait_for_data(sk, timeout);
 695         if (rc) {
 696                 dprintk("%s: llc_ui_wait_for_data failed recv "
 697                         "in %02X from %02X\n", __FUNCTION__,
 698                         llc_sk(sk)->laddr.lsap, llc_sk(sk)->daddr.lsap);
 699                 goto out;
 700         }
 701         skb = skb_dequeue(&sk->sk_receive_queue);
 702         if (!skb) /* shutdown */
 703                 goto out;
 704         copied = skb->len;
 705         if (copied > size)
 706                 copied = size;
 707         rc = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
 708         if (rc)
 709                 goto dgram_free;
 710         if (skb->len > copied) {
 711                 skb_pull(skb, copied);
 712                 skb_queue_head(&sk->sk_receive_queue, skb);
 713         }
 714         if (uaddr)
 715                 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 716         msg->msg_namelen = sizeof(*uaddr);
 717         if (!skb->list) {
 718 dgram_free:
 719                 kfree_skb(skb);
 720         }
 721 out:
 722         release_sock(sk);
 723         return rc ? : copied;
 724 }
 725
 726 /**
 727  *      llc_ui_sendmsg - Transmit data provided by the socket user.
 728  *      @sock: Socket to transmit data from.
 729  *      @msg: Various user related information.
 730  *      @len: Length of data to transmit.
 731  *
 732  *      Transmit data provided by the socket user.
 733  *      Returns non-negative upon success, negative otherwise.
 734  */
 735 static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock,
 736                           struct msghdr *msg, size_t len)
 737 {
 738         struct sock *sk = sock->sk;
 739         struct llc_sock *llc = llc_sk(sk);
 740         struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name;
 741         int flags = msg->msg_flags;
 742         int noblock = flags & MSG_DONTWAIT;
 743         struct net_device *dev;
 744         struct sk_buff *skb;
 745         size_t size = 0;
 746         int rc = -EINVAL, copied = 0, hdrlen;
 747
 748         dprintk("%s: sending from %02X to %02X\n", __FUNCTION__,
 749                 llc->laddr.lsap, llc->daddr.lsap);
 750         lock_sock(sk);
 751         if (addr) {
 752                 if (msg->msg_namelen < sizeof(*addr))
 753                         goto release;
 754         } else {
 755                 if (llc_ui_addr_null(&llc->addr))
 756                         goto release;
 757                 addr = &llc->addr;
 758         }
 759         /* must bind connection to sap if user hasn't done it. */
 760         if (sock_flag(sk, SOCK_ZAPPED)) {
 761                 /* bind to sap with null dev, exclusive. */
 762                 rc = llc_ui_autobind(sock, addr);
 763                 if (rc)
 764                         goto release;
 765         }
 766         dev = llc->dev;
 767         hdrlen = dev->hard_header_len + llc_ui_header_len(sk, addr);
 768         size = hdrlen + len;
 769         if (size > dev->mtu)
 770                 size = dev->mtu;
 771         copied = size - hdrlen;
 772         release_sock(sk);
 773         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 774         lock_sock(sk);
 775         if (!skb)
 776                 goto release;
 777         skb->sk       = sk;
 778         skb->dev      = dev;
 779         skb->protocol = llc_proto_type(addr->sllc_arphrd);
 780         skb_reserve(skb, hdrlen);
 781         rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied);
 782         if (rc)
 783                 goto out;
 784         if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
 785                 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
 786                                           addr->sllc_sap);
 787                 goto out;
 788         }
 789         if (addr->sllc_test) {
 790                 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
 791                                             addr->sllc_sap);
 792                 goto out;
 793         }
 794         if (addr->sllc_xid) {
 795                 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
 796                                            addr->sllc_sap);
 797                 goto out;
 798         }
 799         rc = -ENOPROTOOPT;
 800         if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
 801                 goto out;
 802         rc = llc_ui_send_data(sk, skb, noblock);
 803         if (rc)
 804                 dprintk("%s: llc_ui_send_data failed: %d\n", __FUNCTION__, rc);
 805 out:
 806         if (rc)
 807                 kfree_skb(skb);
 808 release:
 809         if (rc)
 810                 dprintk("%s: failed sending from %02X to %02X: %d\n",
 811                         __FUNCTION__, llc->laddr.lsap, llc->daddr.lsap, rc);
 812         release_sock(sk);
 813         return rc ? : copied;
 814 }
 815
 816 /**
 817  *      llc_ui_getname - return the address info of a socket
 818  *      @sock: Socket to get address of.
 819  *      @uaddr: Address structure to return information.
 820  *      @uaddrlen: Length of address structure.
 821  *      @peer: Does user want local or remote address information.
 822  *
 823  *      Return the address information of a socket.
 824  */
 825 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
 826                           int *uaddrlen, int peer)
 827 {
 828         struct sockaddr_llc sllc;
 829         struct sock *sk = sock->sk;
 830         struct llc_sock *llc = llc_sk(sk);
 831         int rc = 0;
 832
 833         lock_sock(sk);
 834         if (sock_flag(sk, SOCK_ZAPPED))
 835                 goto out;
 836         *uaddrlen = sizeof(sllc);
 837         memset(uaddr, 0, *uaddrlen);
 838         if (peer) {
 839                 rc = -ENOTCONN;
 840                 if (sk->sk_state != TCP_ESTABLISHED)
 841                         goto out;
 842                 if(llc->dev)
 843                         sllc.sllc_arphrd = llc->dev->type;
 844                 sllc.sllc_sap = llc->daddr.lsap;
 845                 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
 846         } else {
 847                 rc = -EINVAL;
 848                 if (!llc->sap)
 849                         goto out;
 850                 sllc.sllc_sap = llc->sap->laddr.lsap;
 851
 852                 if (llc->dev) {
 853                         sllc.sllc_arphrd = llc->dev->type;
 854                         memcpy(&sllc.sllc_mac, &llc->dev->dev_addr,
 855                                IFHWADDRLEN);
 856                 }
 857         }
 858         rc = 0;
 859         sllc.sllc_family = AF_LLC;
 860         memcpy(uaddr, &sllc, sizeof(sllc));
 861 out:
 862         release_sock(sk);
 863         return rc;
 864 }
 865
 866 /**
 867  *      llc_ui_ioctl - io controls for PF_LLC
 868  *      @sock: Socket to get/set info
 869  *      @cmd: command
 870  *      @arg: optional argument for cmd
 871  *
 872  *      get/set info on llc sockets
 873  */
 874 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
 875                         unsigned long arg)
 876 {
 877         return dev_ioctl(cmd, (void __user *)arg);
 878 }
 879
 880 /**
 881  *      llc_ui_setsockopt - set various connection specific parameters.
 882  *      @sock: Socket to set options on.
 883  *      @level: Socket level user is requesting operations on.
 884  *      @optname: Operation name.
 885  *      @optval User provided operation data.
 886  *      @optlen: Length of optval.
 887  *
 888  *      Set various connection specific parameters.
 889  */
 890 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
 891                              char __user *optval, int optlen)
 892 {
 893         struct sock *sk = sock->sk;
 894         struct llc_sock *llc = llc_sk(sk);
 895         int rc = -EINVAL, opt;
 896
 897         lock_sock(sk);
 898         if (level != SOL_LLC || optlen != sizeof(int))
 899                 goto out;
 900         rc = get_user(opt, (int __user *)optval);
 901         if (rc)
 902                 goto out;
 903         rc = -EINVAL;
 904         switch (optname) {
 905         case LLC_OPT_RETRY:
 906                 if (opt > LLC_OPT_MAX_RETRY)
 907                         goto out;
 908                 llc->n2 = opt;
 909                 break;
 910         case LLC_OPT_SIZE:
 911                 if (opt > LLC_OPT_MAX_SIZE)
 912                         goto out;
 913                 llc->n1 = opt;
 914                 break;
 915         case LLC_OPT_ACK_TMR_EXP:
 916                 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
 917                         goto out;
 918                 llc->ack_timer.expire = opt;
 919                 break;
 920         case LLC_OPT_P_TMR_EXP:
 921                 if (opt > LLC_OPT_MAX_P_TMR_EXP)
 922                         goto out;
 923                 llc->pf_cycle_timer.expire = opt;
 924                 break;
 925         case LLC_OPT_REJ_TMR_EXP:
 926                 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
 927                         goto out;
 928                 llc->rej_sent_timer.expire = opt;
 929                 break;
 930         case LLC_OPT_BUSY_TMR_EXP:
 931                 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
 932                         goto out;
 933                 llc->busy_state_timer.expire = opt;
 934                 break;
 935         case LLC_OPT_TX_WIN:
 936                 if (opt > LLC_OPT_MAX_WIN)
 937                         goto out;
 938                 llc->k = opt;
 939                 break;
 940         case LLC_OPT_RX_WIN:
 941                 if (opt > LLC_OPT_MAX_WIN)
 942                         goto out;
 943                 llc->rw = opt;
 944                 break;
 945         default:
 946                 rc = -ENOPROTOOPT;
 947                 goto out;
 948         }
 949         rc = 0;
 950 out:
 951         release_sock(sk);
 952         return rc;
 953 }
 954
 955 /**
 956  *      llc_ui_getsockopt - get connection specific socket info
 957  *      @sock: Socket to get information from.
 958  *      @level: Socket level user is requesting operations on.
 959  *      @optname: Operation name.
 960  *      @optval: Variable to return operation data in.
 961  *      @optlen: Length of optval.
 962  *
 963  *      Get connection specific socket information.
 964  */
 965 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
 966                              char __user *optval, int __user *optlen)
 967 {
 968         struct sock *sk = sock->sk;
 969         struct llc_sock *llc = llc_sk(sk);
 970         int val = 0, len = 0, rc = -EINVAL;
 971
 972         lock_sock(sk);
 973         if (level != SOL_LLC)
 974                 goto out;
 975         rc = get_user(len, optlen);
 976         if (rc)
 977                 goto out;
 978         rc = -EINVAL;
 979         if (len != sizeof(int))
 980                 goto out;
 981         switch (optname) {
 982         case LLC_OPT_RETRY:
 983                 val = llc->n2;                          break;
 984         case LLC_OPT_SIZE:
 985                 val = llc->n1;                          break;
 986         case LLC_OPT_ACK_TMR_EXP:
 987                 val = llc->ack_timer.expire;            break;
 988         case LLC_OPT_P_TMR_EXP:
 989                 val = llc->pf_cycle_timer.expire;       break;
 990         case LLC_OPT_REJ_TMR_EXP:
 991                 val = llc->rej_sent_timer.expire;       break;
 992         case LLC_OPT_BUSY_TMR_EXP:
 993                 val = llc->busy_state_timer.expire;     break;
 994         case LLC_OPT_TX_WIN:
 995                 val = llc->k;                           break;
 996         case LLC_OPT_RX_WIN:
 997                 val = llc->rw;                          break;
 998         default:
 999                 rc = -ENOPROTOOPT;
1000                 goto out;
1001         }
1002         rc = 0;
1003         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1004                 rc = -EFAULT;
1005 out:
1006         release_sock(sk);
1007         return rc;
1008 }
1009
1010 static struct net_proto_family llc_ui_family_ops = {
1011         .family = PF_LLC,
1012         .create = llc_ui_create,
1013         .owner  = THIS_MODULE,
1014 };
1015
1016 static struct proto_ops llc_ui_ops = {
1017         .family      = PF_LLC,
1018         .owner       = THIS_MODULE,
1019         .release     = llc_ui_release,
1020         .bind        = llc_ui_bind,
1021         .connect     = llc_ui_connect,
1022         .socketpair  = sock_no_socketpair,
1023         .accept      = llc_ui_accept,
1024         .getname     = llc_ui_getname,
1025         .poll        = datagram_poll,
1026         .ioctl       = llc_ui_ioctl,
1027         .listen      = llc_ui_listen,
1028         .shutdown    = llc_ui_shutdown,
1029         .setsockopt  = llc_ui_setsockopt,
1030         .getsockopt  = llc_ui_getsockopt,
1031         .sendmsg     = llc_ui_sendmsg,
1032         .recvmsg     = llc_ui_recvmsg,
1033         .mmap        = sock_no_mmap,
1034         .sendpage    = sock_no_sendpage,
1035 };
1036
1037 extern void llc_sap_handler(struct llc_sap *sap, struct sk_buff *skb);
1038 extern void llc_conn_handler(struct llc_sap *sap, struct sk_buff *skb);
1039
1040 static int __init llc2_init(void)
1041 {
1042         int rc = proto_register(&llc_proto, 0);
1043
1044         if (rc != 0)
1045                 goto out;
1046
1047         llc_build_offset_table();
1048         llc_station_init();
1049         llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1050         rc = llc_proc_init();
1051         if (rc != 0)
1052                 goto out_unregister_llc_proto;
1053         sock_register(&llc_ui_family_ops);
1054         llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1055         llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1056 out:
1057         return rc;
1058 out_unregister_llc_proto:
1059         proto_unregister(&llc_proto);
1060         goto out;
1061 }
1062
1063 static void __exit llc2_exit(void)
1064 {
1065         llc_station_exit();
1066         llc_remove_pack(LLC_DEST_SAP);
1067         llc_remove_pack(LLC_DEST_CONN);
1068         sock_unregister(PF_LLC);
1069         llc_proc_exit();
1070         proto_unregister(&llc_proto);
1071 }
1072
1073 module_init(llc2_init);
1074 module_exit(llc2_exit);
1075
1076 MODULE_LICENSE("GPL");
1077 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1078 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1079 MODULE_ALIAS_NETPROTO(PF_LLC);