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 arphrd == ARPHRD_IEEE802_TR ?
  75                          htons(ETH_P_TR_802_2) : htons(ETH_P_802_2);
  76 }
  77
  78 /**
  79  *      llc_ui_addr_null - determines if a address structure is null
  80  *      @addr: Address to test if null.
  81  */
  82 static inline u8 llc_ui_addr_null(struct sockaddr_llc *addr)
  83 {
  84         return !memcmp(addr, &llc_ui_addrnull, sizeof(*addr));
  85 }
  86
  87 /**
  88  *      llc_ui_header_len - return length of llc header based on operation
  89  *      @sk: Socket which contains a valid llc socket type.
  90  *      @addr: Complete sockaddr_llc structure received from the user.
  91  *
  92  *      Provide the length of the llc header depending on what kind of
  93  *      operation the user would like to perform and the type of socket.
  94  *      Returns the correct llc header length.
  95  */
  96 static inline u8 llc_ui_header_len(struct sock *sk, struct sockaddr_llc *addr)
  97 {
  98         u8 rc = LLC_PDU_LEN_U;
  99
 100         if (addr->sllc_test || addr->sllc_xid)
 101                 rc = LLC_PDU_LEN_U;
 102         else if (sk->sk_type == SOCK_STREAM)
 103                 rc = LLC_PDU_LEN_I;
 104         return rc;
 105 }
 106
 107 /**
 108  *      llc_ui_send_data - send data via reliable llc2 connection
 109  *      @sk: Connection the socket is using.
 110  *      @skb: Data the user wishes to send.
 111  *      @noblock: can we block waiting for data?
 112  *
 113  *      Send data via reliable llc2 connection.
 114  *      Returns 0 upon success, non-zero if action did not succeed.
 115  */
 116 static int llc_ui_send_data(struct sock* sk, struct sk_buff *skb, int noblock)
 117 {
 118         struct llc_sock* llc = llc_sk(sk);
 119         int rc = 0;
 120
 121         if (unlikely(llc_data_accept_state(llc->state) ||
 122                      llc->remote_busy_flag ||
 123                      llc->p_flag)) {
 124                 long timeout = sock_sndtimeo(sk, noblock);
 125
 126                 rc = llc_ui_wait_for_busy_core(sk, timeout);
 127         }
 128         if (unlikely(!rc))
 129                 rc = llc_build_and_send_pkt(sk, skb);
 130         return rc;
 131 }
 132
 133 static void llc_ui_sk_init(struct socket *sock, struct sock *sk)
 134 {
 135         sock_graft(sk, sock);
 136         sk->sk_type     = sock->type;
 137         sock->ops       = &llc_ui_ops;
 138 }
 139
 140 static struct proto llc_proto = {
 141         .name     = "LLC",
 142         .owner    = THIS_MODULE,
 143         .obj_size = sizeof(struct llc_sock),
 144         .slab_flags = SLAB_DESTROY_BY_RCU,
 145 };
 146
 147 /**
 148  *      llc_ui_create - alloc and init a new llc_ui socket
 149  *      @net: network namespace (must be default network)
 150  *      @sock: Socket to initialize and attach allocated sk to.
 151  *      @protocol: Unused.
 152  *      @kern: on behalf of kernel or userspace
 153  *
 154  *      Allocate and initialize a new llc_ui socket, validate the user wants a
 155  *      socket type we have available.
 156  *      Returns 0 upon success, negative upon failure.
 157  */
 158 static int llc_ui_create(struct net *net, struct socket *sock, int protocol,
 159                          int kern)
 160 {
 161         struct sock *sk;
 162         int rc = -ESOCKTNOSUPPORT;
 163
 164         if (!capable(CAP_NET_RAW))
 165                 return -EPERM;
 166
 167         if (!net_eq(net, &init_net))
 168                 return -EAFNOSUPPORT;
 169
 170         if (likely(sock->type == SOCK_DGRAM || sock->type == SOCK_STREAM)) {
 171                 rc = -ENOMEM;
 172                 sk = llc_sk_alloc(net, PF_LLC, GFP_KERNEL, &llc_proto);
 173                 if (sk) {
 174                         rc = 0;
 175                         llc_ui_sk_init(sock, sk);
 176                 }
 177         }
 178         return rc;
 179 }
 180
 181 /**
 182  *      llc_ui_release - shutdown socket
 183  *      @sock: Socket to release.
 184  *
 185  *      Shutdown and deallocate an existing socket.
 186  */
 187 static int llc_ui_release(struct socket *sock)
 188 {
 189         struct sock *sk = sock->sk;
 190         struct llc_sock *llc;
 191
 192         if (unlikely(sk == NULL))
 193                 goto out;
 194         sock_hold(sk);
 195         lock_sock(sk);
 196         llc = llc_sk(sk);
 197         dprintk("%s: closing local(%02X) remote(%02X)\n", __func__,
 198                 llc->laddr.lsap, llc->daddr.lsap);
 199         if (!llc_send_disc(sk))
 200                 llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 201         if (!sock_flag(sk, SOCK_ZAPPED))
 202                 llc_sap_remove_socket(llc->sap, sk);
 203         release_sock(sk);
 204         if (llc->dev)
 205                 dev_put(llc->dev);
 206         sock_put(sk);
 207         llc_sk_free(sk);
 208 out:
 209         return 0;
 210 }
 211
 212 /**
 213  *      llc_ui_autoport - provide dynamically allocate SAP number
 214  *
 215  *      Provide the caller with a dynamically allocated SAP number according
 216  *      to the rules that are set in this function. Returns: 0, upon failure,
 217  *      SAP number otherwise.
 218  */
 219 static int llc_ui_autoport(void)
 220 {
 221         struct llc_sap *sap;
 222         int i, tries = 0;
 223
 224         while (tries < LLC_SAP_DYN_TRIES) {
 225                 for (i = llc_ui_sap_last_autoport;
 226                      i < LLC_SAP_DYN_STOP; i += 2) {
 227                         sap = llc_sap_find(i);
 228                         if (!sap) {
 229                                 llc_ui_sap_last_autoport = i + 2;
 230                                 goto out;
 231                         }
 232                         llc_sap_put(sap);
 233                 }
 234                 llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
 235                 tries++;
 236         }
 237         i = 0;
 238 out:
 239         return i;
 240 }
 241
 242 /**
 243  *      llc_ui_autobind - automatically bind a socket to a sap
 244  *      @sock: socket to bind
 245  *      @addr: address to connect to
 246  *
 247  *      Used by llc_ui_connect and llc_ui_sendmsg when the user hasn't
 248  *      specifically used llc_ui_bind to bind to an specific address/sap
 249  *
 250  *      Returns: 0 upon success, negative otherwise.
 251  */
 252 static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
 253 {
 254         struct sock *sk = sock->sk;
 255         struct llc_sock *llc = llc_sk(sk);
 256         struct llc_sap *sap;
 257         int rc = -EINVAL;
 258
 259         if (!sock_flag(sk, SOCK_ZAPPED))
 260                 goto out;
 261         rc = -ENODEV;
 262         if (sk->sk_bound_dev_if) {
 263                 llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if);
 264                 if (llc->dev && addr->sllc_arphrd != llc->dev->type) {
 265                         dev_put(llc->dev);
 266                         llc->dev = NULL;
 267                 }
 268         } else
 269                 llc->dev = dev_getfirstbyhwtype(&init_net, addr->sllc_arphrd);
 270         if (!llc->dev)
 271                 goto out;
 272         rc = -EUSERS;
 273         llc->laddr.lsap = llc_ui_autoport();
 274         if (!llc->laddr.lsap)
 275                 goto out;
 276         rc = -EBUSY; /* some other network layer is using the sap */
 277         sap = llc_sap_open(llc->laddr.lsap, NULL);
 278         if (!sap)
 279                 goto out;
 280         memcpy(llc->laddr.mac, llc->dev->dev_addr, IFHWADDRLEN);
 281         memcpy(&llc->addr, addr, sizeof(llc->addr));
 282         /* assign new connection to its SAP */
 283         llc_sap_add_socket(sap, sk);
 284         sock_reset_flag(sk, SOCK_ZAPPED);
 285         rc = 0;
 286 out:
 287         return rc;
 288 }
 289
 290 /**
 291  *      llc_ui_bind - bind a socket to a specific address.
 292  *      @sock: Socket to bind an address to.
 293  *      @uaddr: Address the user wants the socket bound to.
 294  *      @addrlen: Length of the uaddr structure.
 295  *
 296  *      Bind a socket to a specific address. For llc a user is able to bind to
 297  *      a specific sap only or mac + sap.
 298  *      If the user desires to bind to a specific mac + sap, it is possible to
 299  *      have multiple sap connections via multiple macs.
 300  *      Bind and autobind for that matter must enforce the correct sap usage
 301  *      otherwise all hell will break loose.
 302  *      Returns: 0 upon success, negative otherwise.
 303  */
 304 static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen)
 305 {
 306         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 307         struct sock *sk = sock->sk;
 308         struct llc_sock *llc = llc_sk(sk);
 309         struct llc_sap *sap;
 310         int rc = -EINVAL;
 311
 312         dprintk("%s: binding %02X\n", __func__, addr->sllc_sap);
 313         if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr)))
 314                 goto out;
 315         rc = -EAFNOSUPPORT;
 316         if (unlikely(addr->sllc_family != AF_LLC))
 317                 goto out;
 318         rc = -ENODEV;
 319         rcu_read_lock();
 320         if (sk->sk_bound_dev_if) {
 321                 llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if);
 322                 if (llc->dev) {
 323                         if (!addr->sllc_arphrd)
 324                                 addr->sllc_arphrd = llc->dev->type;
 325                         if (llc_mac_null(addr->sllc_mac))
 326                                 memcpy(addr->sllc_mac, llc->dev->dev_addr,
 327                                        IFHWADDRLEN);
 328                         if (addr->sllc_arphrd != llc->dev->type ||
 329                             !llc_mac_match(addr->sllc_mac,
 330                                            llc->dev->dev_addr)) {
 331                                 rc = -EINVAL;
 332                                 llc->dev = NULL;
 333                         }
 334                 }
 335         } else
 336                 llc->dev = dev_getbyhwaddr_rcu(&init_net, addr->sllc_arphrd,
 337                                            addr->sllc_mac);
 338         if (llc->dev)
 339                 dev_hold(llc->dev);
 340         rcu_read_unlock();
 341         if (!llc->dev)
 342                 goto out;
 343         if (!addr->sllc_sap) {
 344                 rc = -EUSERS;
 345                 addr->sllc_sap = llc_ui_autoport();
 346                 if (!addr->sllc_sap)
 347                         goto out;
 348         }
 349         sap = llc_sap_find(addr->sllc_sap);
 350         if (!sap) {
 351                 sap = llc_sap_open(addr->sllc_sap, NULL);
 352                 rc = -EBUSY; /* some other network layer is using the sap */
 353                 if (!sap)
 354                         goto out;
 355         } else {
 356                 struct llc_addr laddr, daddr;
 357                 struct sock *ask;
 358
 359                 memset(&laddr, 0, sizeof(laddr));
 360                 memset(&daddr, 0, sizeof(daddr));
 361                 /*
 362                  * FIXME: check if the address is multicast,
 363                  *        only SOCK_DGRAM can do this.
 364                  */
 365                 memcpy(laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 366                 laddr.lsap = addr->sllc_sap;
 367                 rc = -EADDRINUSE; /* mac + sap clash. */
 368                 ask = llc_lookup_established(sap, &daddr, &laddr);
 369                 if (ask) {
 370                         sock_put(ask);
 371                         goto out_put;
 372                 }
 373         }
 374         llc->laddr.lsap = addr->sllc_sap;
 375         memcpy(llc->laddr.mac, addr->sllc_mac, IFHWADDRLEN);
 376         memcpy(&llc->addr, addr, sizeof(llc->addr));
 377         /* assign new connection to its SAP */
 378         llc_sap_add_socket(sap, sk);
 379         sock_reset_flag(sk, SOCK_ZAPPED);
 380         rc = 0;
 381 out_put:
 382         llc_sap_put(sap);
 383 out:
 384         return rc;
 385 }
 386
 387 /**
 388  *      llc_ui_shutdown - shutdown a connect llc2 socket.
 389  *      @sock: Socket to shutdown.
 390  *      @how: What part of the socket to shutdown.
 391  *
 392  *      Shutdown a connected llc2 socket. Currently this function only supports
 393  *      shutting down both sends and receives (2), we could probably make this
 394  *      function such that a user can shutdown only half the connection but not
 395  *      right now.
 396  *      Returns: 0 upon success, negative otherwise.
 397  */
 398 static int llc_ui_shutdown(struct socket *sock, int how)
 399 {
 400         struct sock *sk = sock->sk;
 401         int rc = -ENOTCONN;
 402
 403         lock_sock(sk);
 404         if (unlikely(sk->sk_state != TCP_ESTABLISHED))
 405                 goto out;
 406         rc = -EINVAL;
 407         if (how != 2)
 408                 goto out;
 409         rc = llc_send_disc(sk);
 410         if (!rc)
 411                 rc = llc_ui_wait_for_disc(sk, sk->sk_rcvtimeo);
 412         /* Wake up anyone sleeping in poll */
 413         sk->sk_state_change(sk);
 414 out:
 415         release_sock(sk);
 416         return rc;
 417 }
 418
 419 /**
 420  *      llc_ui_connect - Connect to a remote llc2 mac + sap.
 421  *      @sock: Socket which will be connected to the remote destination.
 422  *      @uaddr: Remote and possibly the local address of the new connection.
 423  *      @addrlen: Size of uaddr structure.
 424  *      @flags: Operational flags specified by the user.
 425  *
 426  *      Connect to a remote llc2 mac + sap. The caller must specify the
 427  *      destination mac and address to connect to. If the user hasn't previously
 428  *      called bind(2) with a smac the address of the first interface of the
 429  *      specified arp type will be used.
 430  *      This function will autobind if user did not previously call bind.
 431  *      Returns: 0 upon success, negative otherwise.
 432  */
 433 static int llc_ui_connect(struct socket *sock, struct sockaddr *uaddr,
 434                           int addrlen, int flags)
 435 {
 436         struct sock *sk = sock->sk;
 437         struct llc_sock *llc = llc_sk(sk);
 438         struct sockaddr_llc *addr = (struct sockaddr_llc *)uaddr;
 439         int rc = -EINVAL;
 440
 441         lock_sock(sk);
 442         if (unlikely(addrlen != sizeof(*addr)))
 443                 goto out;
 444         rc = -EAFNOSUPPORT;
 445         if (unlikely(addr->sllc_family != AF_LLC))
 446                 goto out;
 447         if (unlikely(sk->sk_type != SOCK_STREAM))
 448                 goto out;
 449         rc = -EALREADY;
 450         if (unlikely(sock->state == SS_CONNECTING))
 451                 goto out;
 452         /* bind connection to sap if user hasn't done it. */
 453         if (sock_flag(sk, SOCK_ZAPPED)) {
 454                 /* bind to sap with null dev, exclusive */
 455                 rc = llc_ui_autobind(sock, addr);
 456                 if (rc)
 457                         goto out;
 458         }
 459         llc->daddr.lsap = addr->sllc_sap;
 460         memcpy(llc->daddr.mac, addr->sllc_mac, IFHWADDRLEN);
 461         sock->state = SS_CONNECTING;
 462         sk->sk_state   = TCP_SYN_SENT;
 463         llc->link   = llc_ui_next_link_no(llc->sap->laddr.lsap);
 464         rc = llc_establish_connection(sk, llc->dev->dev_addr,
 465                                       addr->sllc_mac, addr->sllc_sap);
 466         if (rc) {
 467                 dprintk("%s: llc_ui_send_conn failed :-(\n", __func__);
 468                 sock->state  = SS_UNCONNECTED;
 469                 sk->sk_state = TCP_CLOSE;
 470                 goto out;
 471         }
 472
 473         if (sk->sk_state == TCP_SYN_SENT) {
 474                 const long timeo = sock_sndtimeo(sk, flags & O_NONBLOCK);
 475
 476                 if (!timeo || !llc_ui_wait_for_conn(sk, timeo))
 477                         goto out;
 478
 479                 rc = sock_intr_errno(timeo);
 480                 if (signal_pending(current))
 481                         goto out;
 482         }
 483
 484         if (sk->sk_state == TCP_CLOSE)
 485                 goto sock_error;
 486
 487         sock->state = SS_CONNECTED;
 488         rc = 0;
 489 out:
 490         release_sock(sk);
 491         return rc;
 492 sock_error:
 493         rc = sock_error(sk) ? : -ECONNABORTED;
 494         sock->state = SS_UNCONNECTED;
 495         goto out;
 496 }
 497
 498 /**
 499  *      llc_ui_listen - allow a normal socket to accept incoming connections
 500  *      @sock: Socket to allow incoming connections on.
 501  *      @backlog: Number of connections to queue.
 502  *
 503  *      Allow a normal socket to accept incoming connections.
 504  *      Returns 0 upon success, negative otherwise.
 505  */
 506 static int llc_ui_listen(struct socket *sock, int backlog)
 507 {
 508         struct sock *sk = sock->sk;
 509         int rc = -EINVAL;
 510
 511         lock_sock(sk);
 512         if (unlikely(sock->state != SS_UNCONNECTED))
 513                 goto out;
 514         rc = -EOPNOTSUPP;
 515         if (unlikely(sk->sk_type != SOCK_STREAM))
 516                 goto out;
 517         rc = -EAGAIN;
 518         if (sock_flag(sk, SOCK_ZAPPED))
 519                 goto out;
 520         rc = 0;
 521         if (!(unsigned)backlog) /* BSDism */
 522                 backlog = 1;
 523         sk->sk_max_ack_backlog = backlog;
 524         if (sk->sk_state != TCP_LISTEN) {
 525                 sk->sk_ack_backlog = 0;
 526                 sk->sk_state       = TCP_LISTEN;
 527         }
 528         sk->sk_socket->flags |= __SO_ACCEPTCON;
 529 out:
 530         release_sock(sk);
 531         return rc;
 532 }
 533
 534 static int llc_ui_wait_for_disc(struct sock *sk, long timeout)
 535 {
 536         DEFINE_WAIT(wait);
 537         int rc = 0;
 538
 539         while (1) {
 540                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 541                 if (sk_wait_event(sk, &timeout, sk->sk_state == TCP_CLOSE))
 542                         break;
 543                 rc = -ERESTARTSYS;
 544                 if (signal_pending(current))
 545                         break;
 546                 rc = -EAGAIN;
 547                 if (!timeout)
 548                         break;
 549                 rc = 0;
 550         }
 551         finish_wait(sk_sleep(sk), &wait);
 552         return rc;
 553 }
 554
 555 static int llc_ui_wait_for_conn(struct sock *sk, long timeout)
 556 {
 557         DEFINE_WAIT(wait);
 558
 559         while (1) {
 560                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 561                 if (sk_wait_event(sk, &timeout, sk->sk_state != TCP_SYN_SENT))
 562                         break;
 563                 if (signal_pending(current) || !timeout)
 564                         break;
 565         }
 566         finish_wait(sk_sleep(sk), &wait);
 567         return timeout;
 568 }
 569
 570 static int llc_ui_wait_for_busy_core(struct sock *sk, long timeout)
 571 {
 572         DEFINE_WAIT(wait);
 573         struct llc_sock *llc = llc_sk(sk);
 574         int rc;
 575
 576         while (1) {
 577                 prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
 578                 rc = 0;
 579                 if (sk_wait_event(sk, &timeout,
 580                                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
 581                                   (!llc_data_accept_state(llc->state) &&
 582                                    !llc->remote_busy_flag &&
 583                                    !llc->p_flag)))
 584                         break;
 585                 rc = -ERESTARTSYS;
 586                 if (signal_pending(current))
 587                         break;
 588                 rc = -EAGAIN;
 589                 if (!timeout)
 590                         break;
 591         }
 592         finish_wait(sk_sleep(sk), &wait);
 593         return rc;
 594 }
 595
 596 static int llc_wait_data(struct sock *sk, long timeo)
 597 {
 598         int rc;
 599
 600         while (1) {
 601                 /*
 602                  * POSIX 1003.1g mandates this order.
 603                  */
 604                 rc = sock_error(sk);
 605                 if (rc)
 606                         break;
 607                 rc = 0;
 608                 if (sk->sk_shutdown & RCV_SHUTDOWN)
 609                         break;
 610                 rc = -EAGAIN;
 611                 if (!timeo)
 612                         break;
 613                 rc = sock_intr_errno(timeo);
 614                 if (signal_pending(current))
 615                         break;
 616                 rc = 0;
 617                 if (sk_wait_data(sk, &timeo))
 618                         break;
 619         }
 620         return rc;
 621 }
 622
 623 static void llc_cmsg_rcv(struct msghdr *msg, struct sk_buff *skb)
 624 {
 625         struct llc_sock *llc = llc_sk(skb->sk);
 626
 627         if (llc->cmsg_flags & LLC_CMSG_PKTINFO) {
 628                 struct llc_pktinfo info;
 629
 630                 info.lpi_ifindex = llc_sk(skb->sk)->dev->ifindex;
 631                 llc_pdu_decode_dsap(skb, &info.lpi_sap);
 632                 llc_pdu_decode_da(skb, info.lpi_mac);
 633                 put_cmsg(msg, SOL_LLC, LLC_OPT_PKTINFO, sizeof(info), &info);
 634         }
 635 }
 636
 637 /**
 638  *      llc_ui_accept - accept a new incoming connection.
 639  *      @sock: Socket which connections arrive on.
 640  *      @newsock: Socket to move incoming connection to.
 641  *      @flags: User specified operational flags.
 642  *
 643  *      Accept a new incoming connection.
 644  *      Returns 0 upon success, negative otherwise.
 645  */
 646 static int llc_ui_accept(struct socket *sock, struct socket *newsock, int flags)
 647 {
 648         struct sock *sk = sock->sk, *newsk;
 649         struct llc_sock *llc, *newllc;
 650         struct sk_buff *skb;
 651         int rc = -EOPNOTSUPP;
 652
 653         dprintk("%s: accepting on %02X\n", __func__,
 654                 llc_sk(sk)->laddr.lsap);
 655         lock_sock(sk);
 656         if (unlikely(sk->sk_type != SOCK_STREAM))
 657                 goto out;
 658         rc = -EINVAL;
 659         if (unlikely(sock->state != SS_UNCONNECTED ||
 660                      sk->sk_state != TCP_LISTEN))
 661                 goto out;
 662         /* wait for a connection to arrive. */
 663         if (skb_queue_empty(&sk->sk_receive_queue)) {
 664                 rc = llc_wait_data(sk, sk->sk_rcvtimeo);
 665                 if (rc)
 666                         goto out;
 667         }
 668         dprintk("%s: got a new connection on %02X\n", __func__,
 669                 llc_sk(sk)->laddr.lsap);
 670         skb = skb_dequeue(&sk->sk_receive_queue);
 671         rc = -EINVAL;
 672         if (!skb->sk)
 673                 goto frees;
 674         rc = 0;
 675         newsk = skb->sk;
 676         /* attach connection to a new socket. */
 677         llc_ui_sk_init(newsock, newsk);
 678         sock_reset_flag(newsk, SOCK_ZAPPED);
 679         newsk->sk_state         = TCP_ESTABLISHED;
 680         newsock->state          = SS_CONNECTED;
 681         llc                     = llc_sk(sk);
 682         newllc                  = llc_sk(newsk);
 683         memcpy(&newllc->addr, &llc->addr, sizeof(newllc->addr));
 684         newllc->link = llc_ui_next_link_no(newllc->laddr.lsap);
 685
 686         /* put original socket back into a clean listen state. */
 687         sk->sk_state = TCP_LISTEN;
 688         sk->sk_ack_backlog--;
 689         dprintk("%s: ok success on %02X, client on %02X\n", __func__,
 690                 llc_sk(sk)->addr.sllc_sap, newllc->daddr.lsap);
 691 frees:
 692         kfree_skb(skb);
 693 out:
 694         release_sock(sk);
 695         return rc;
 696 }
 697
 698 /**
 699  *      llc_ui_recvmsg - copy received data to the socket user.
 700  *      @sock: Socket to copy data from.
 701  *      @msg: Various user space related information.
 702  *      @len: Size of user buffer.
 703  *      @flags: User specified flags.
 704  *
 705  *      Copy received data to the socket user.
 706  *      Returns non-negative upon success, negative otherwise.
 707  */
 708 static int llc_ui_recvmsg(struct kiocb *iocb, struct socket *sock,
 709                           struct msghdr *msg, size_t len, int flags)
 710 {
 711         struct sockaddr_llc *uaddr = (struct sockaddr_llc *)msg->msg_name;
 712         const int nonblock = flags & MSG_DONTWAIT;
 713         struct sk_buff *skb = NULL;
 714         struct sock *sk = sock->sk;
 715         struct llc_sock *llc = llc_sk(sk);
 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         lock_sock(sk);
 724         copied = -ENOTCONN;
 725         if (unlikely(sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_LISTEN))
 726                 goto out;
 727
 728         timeo = sock_rcvtimeo(sk, nonblock);
 729
 730         seq = &llc->copied_seq;
 731         if (flags & MSG_PEEK) {
 732                 peek_seq = llc->copied_seq;
 733                 seq = &peek_seq;
 734         }
 735
 736         target = sock_rcvlowat(sk, flags & MSG_WAITALL, len);
 737         copied = 0;
 738
 739         do {
 740                 u32 offset;
 741
 742                 /*
 743                  * We need to check signals first, to get correct SIGURG
 744                  * handling. FIXME: Need to check this doesn't impact 1003.1g
 745                  * and move it down to the bottom of the loop
 746                  */
 747                 if (signal_pending(current)) {
 748                         if (copied)
 749                                 break;
 750                         copied = timeo ? sock_intr_errno(timeo) : -EAGAIN;
 751                         break;
 752                 }
 753
 754                 /* Next get a buffer. */
 755
 756                 skb = skb_peek(&sk->sk_receive_queue);
 757                 if (skb) {
 758                         offset = *seq;
 759                         goto found_ok_skb;
 760                 }
 761                 /* Well, if we have backlog, try to process it now yet. */
 762
 763                 if (copied >= target && !sk->sk_backlog.tail)
 764                         break;
 765
 766                 if (copied) {
 767                         if (sk->sk_err ||
 768                             sk->sk_state == TCP_CLOSE ||
 769                             (sk->sk_shutdown & RCV_SHUTDOWN) ||
 770                             !timeo ||
 771                             (flags & MSG_PEEK))
 772                                 break;
 773                 } else {
 774                         if (sock_flag(sk, SOCK_DONE))
 775                                 break;
 776
 777                         if (sk->sk_err) {
 778                                 copied = sock_error(sk);
 779                                 break;
 780                         }
 781                         if (sk->sk_shutdown & RCV_SHUTDOWN)
 782                                 break;
 783
 784                         if (sk->sk_type == SOCK_STREAM && sk->sk_state == TCP_CLOSE) {
 785                                 if (!sock_flag(sk, SOCK_DONE)) {
 786                                         /*
 787                                          * This occurs when user tries to read
 788                                          * from never connected socket.
 789                                          */
 790                                         copied = -ENOTCONN;
 791                                         break;
 792                                 }
 793                                 break;
 794                         }
 795                         if (!timeo) {
 796                                 copied = -EAGAIN;
 797                                 break;
 798                         }
 799                 }
 800
 801                 if (copied >= target) { /* Do not sleep, just process backlog. */
 802                         release_sock(sk);
 803                         lock_sock(sk);
 804                 } else
 805                         sk_wait_data(sk, &timeo);
 806
 807                 if ((flags & MSG_PEEK) && peek_seq != llc->copied_seq) {
 808                         if (net_ratelimit())
 809                                 printk(KERN_DEBUG "LLC(%s:%d): Application "
 810                                                   "bug, race in MSG_PEEK.\n",
 811                                        current->comm, task_pid_nr(current));
 812                         peek_seq = llc->copied_seq;
 813                 }
 814                 continue;
 815         found_ok_skb:
 816                 /* Ok so how much can we use? */
 817                 used = skb->len - offset;
 818                 if (len < used)
 819                         used = len;
 820
 821                 if (!(flags & MSG_TRUNC)) {
 822                         int rc = skb_copy_datagram_iovec(skb, offset,
 823                                                          msg->msg_iov, used);
 824                         if (rc) {
 825                                 /* Exception. Bailout! */
 826                                 if (!copied)
 827                                         copied = -EFAULT;
 828                                 break;
 829                         }
 830                 }
 831
 832                 *seq += used;
 833                 copied += used;
 834                 len -= used;
 835
 836                 if (!(flags & MSG_PEEK)) {
 837                         sk_eat_skb(sk, skb, 0);
 838                         *seq = 0;
 839                 }
 840
 841                 /* For non stream protcols we get one packet per recvmsg call */
 842                 if (sk->sk_type != SOCK_STREAM)
 843                         goto copy_uaddr;
 844
 845                 /* Partial read */
 846                 if (used + offset < skb->len)
 847                         continue;
 848         } while (len > 0);
 849
 850 out:
 851         release_sock(sk);
 852         return copied;
 853 copy_uaddr:
 854         if (uaddr != NULL && skb != NULL) {
 855                 memcpy(uaddr, llc_ui_skb_cb(skb), sizeof(*uaddr));
 856                 msg->msg_namelen = sizeof(*uaddr);
 857         }
 858         if (llc_sk(sk)->cmsg_flags)
 859                 llc_cmsg_rcv(msg, skb);
 860         goto out;
 861 }
 862
 863 /**
 864  *      llc_ui_sendmsg - Transmit data provided by the socket user.
 865  *      @sock: Socket to transmit data from.
 866  *      @msg: Various user related information.
 867  *      @len: Length of data to transmit.
 868  *
 869  *      Transmit data provided by the socket user.
 870  *      Returns non-negative upon success, negative otherwise.
 871  */
 872 static int llc_ui_sendmsg(struct kiocb *iocb, struct socket *sock,
 873                           struct msghdr *msg, size_t len)
 874 {
 875         struct sock *sk = sock->sk;
 876         struct llc_sock *llc = llc_sk(sk);
 877         struct sockaddr_llc *addr = (struct sockaddr_llc *)msg->msg_name;
 878         int flags = msg->msg_flags;
 879         int noblock = flags & MSG_DONTWAIT;
 880         struct sk_buff *skb;
 881         size_t size = 0;
 882         int rc = -EINVAL, copied = 0, hdrlen;
 883
 884         dprintk("%s: sending from %02X to %02X\n", __func__,
 885                 llc->laddr.lsap, llc->daddr.lsap);
 886         lock_sock(sk);
 887         if (addr) {
 888                 if (msg->msg_namelen < sizeof(*addr))
 889                         goto release;
 890         } else {
 891                 if (llc_ui_addr_null(&llc->addr))
 892                         goto release;
 893                 addr = &llc->addr;
 894         }
 895         /* must bind connection to sap if user hasn't done it. */
 896         if (sock_flag(sk, SOCK_ZAPPED)) {
 897                 /* bind to sap with null dev, exclusive. */
 898                 rc = llc_ui_autobind(sock, addr);
 899                 if (rc)
 900                         goto release;
 901         }
 902         hdrlen = llc->dev->hard_header_len + llc_ui_header_len(sk, addr);
 903         size = hdrlen + len;
 904         if (size > llc->dev->mtu)
 905                 size = llc->dev->mtu;
 906         copied = size - hdrlen;
 907         release_sock(sk);
 908         skb = sock_alloc_send_skb(sk, size, noblock, &rc);
 909         lock_sock(sk);
 910         if (!skb)
 911                 goto release;
 912         skb->dev      = llc->dev;
 913         skb->protocol = llc_proto_type(addr->sllc_arphrd);
 914         skb_reserve(skb, hdrlen);
 915         rc = memcpy_fromiovec(skb_put(skb, copied), msg->msg_iov, copied);
 916         if (rc)
 917                 goto out;
 918         if (sk->sk_type == SOCK_DGRAM || addr->sllc_ua) {
 919                 llc_build_and_send_ui_pkt(llc->sap, skb, addr->sllc_mac,
 920                                           addr->sllc_sap);
 921                 goto out;
 922         }
 923         if (addr->sllc_test) {
 924                 llc_build_and_send_test_pkt(llc->sap, skb, addr->sllc_mac,
 925                                             addr->sllc_sap);
 926                 goto out;
 927         }
 928         if (addr->sllc_xid) {
 929                 llc_build_and_send_xid_pkt(llc->sap, skb, addr->sllc_mac,
 930                                            addr->sllc_sap);
 931                 goto out;
 932         }
 933         rc = -ENOPROTOOPT;
 934         if (!(sk->sk_type == SOCK_STREAM && !addr->sllc_ua))
 935                 goto out;
 936         rc = llc_ui_send_data(sk, skb, noblock);
 937 out:
 938         if (rc) {
 939                 kfree_skb(skb);
 940 release:
 941                 dprintk("%s: failed sending from %02X to %02X: %d\n",
 942                         __func__, llc->laddr.lsap, llc->daddr.lsap, rc);
 943         }
 944         release_sock(sk);
 945         return rc ? : copied;
 946 }
 947
 948 /**
 949  *      llc_ui_getname - return the address info of a socket
 950  *      @sock: Socket to get address of.
 951  *      @uaddr: Address structure to return information.
 952  *      @uaddrlen: Length of address structure.
 953  *      @peer: Does user want local or remote address information.
 954  *
 955  *      Return the address information of a socket.
 956  */
 957 static int llc_ui_getname(struct socket *sock, struct sockaddr *uaddr,
 958                           int *uaddrlen, int peer)
 959 {
 960         struct sockaddr_llc sllc;
 961         struct sock *sk = sock->sk;
 962         struct llc_sock *llc = llc_sk(sk);
 963         int rc = 0;
 964
 965         memset(&sllc, 0, sizeof(sllc));
 966         lock_sock(sk);
 967         if (sock_flag(sk, SOCK_ZAPPED))
 968                 goto out;
 969         *uaddrlen = sizeof(sllc);
 970         memset(uaddr, 0, *uaddrlen);
 971         if (peer) {
 972                 rc = -ENOTCONN;
 973                 if (sk->sk_state != TCP_ESTABLISHED)
 974                         goto out;
 975                 if(llc->dev)
 976                         sllc.sllc_arphrd = llc->dev->type;
 977                 sllc.sllc_sap = llc->daddr.lsap;
 978                 memcpy(&sllc.sllc_mac, &llc->daddr.mac, IFHWADDRLEN);
 979         } else {
 980                 rc = -EINVAL;
 981                 if (!llc->sap)
 982                         goto out;
 983                 sllc.sllc_sap = llc->sap->laddr.lsap;
 984
 985                 if (llc->dev) {
 986                         sllc.sllc_arphrd = llc->dev->type;
 987                         memcpy(&sllc.sllc_mac, llc->dev->dev_addr,
 988                                IFHWADDRLEN);
 989                 }
 990         }
 991         rc = 0;
 992         sllc.sllc_family = AF_LLC;
 993         memcpy(uaddr, &sllc, sizeof(sllc));
 994 out:
 995         release_sock(sk);
 996         return rc;
 997 }
 998
 999 /**
1000  *      llc_ui_ioctl - io controls for PF_LLC
1001  *      @sock: Socket to get/set info
1002  *      @cmd: command
1003  *      @arg: optional argument for cmd
1004  *
1005  *      get/set info on llc sockets
1006  */
1007 static int llc_ui_ioctl(struct socket *sock, unsigned int cmd,
1008                         unsigned long arg)
1009 {
1010         return -ENOIOCTLCMD;
1011 }
1012
1013 /**
1014  *      llc_ui_setsockopt - set various connection specific parameters.
1015  *      @sock: Socket to set options on.
1016  *      @level: Socket level user is requesting operations on.
1017  *      @optname: Operation name.
1018  *      @optval User provided operation data.
1019  *      @optlen: Length of optval.
1020  *
1021  *      Set various connection specific parameters.
1022  */
1023 static int llc_ui_setsockopt(struct socket *sock, int level, int optname,
1024                              char __user *optval, unsigned int optlen)
1025 {
1026         struct sock *sk = sock->sk;
1027         struct llc_sock *llc = llc_sk(sk);
1028         unsigned int opt;
1029         int rc = -EINVAL;
1030
1031         lock_sock(sk);
1032         if (unlikely(level != SOL_LLC || optlen != sizeof(int)))
1033                 goto out;
1034         rc = get_user(opt, (int __user *)optval);
1035         if (rc)
1036                 goto out;
1037         rc = -EINVAL;
1038         switch (optname) {
1039         case LLC_OPT_RETRY:
1040                 if (opt > LLC_OPT_MAX_RETRY)
1041                         goto out;
1042                 llc->n2 = opt;
1043                 break;
1044         case LLC_OPT_SIZE:
1045                 if (opt > LLC_OPT_MAX_SIZE)
1046                         goto out;
1047                 llc->n1 = opt;
1048                 break;
1049         case LLC_OPT_ACK_TMR_EXP:
1050                 if (opt > LLC_OPT_MAX_ACK_TMR_EXP)
1051                         goto out;
1052                 llc->ack_timer.expire = opt * HZ;
1053                 break;
1054         case LLC_OPT_P_TMR_EXP:
1055                 if (opt > LLC_OPT_MAX_P_TMR_EXP)
1056                         goto out;
1057                 llc->pf_cycle_timer.expire = opt * HZ;
1058                 break;
1059         case LLC_OPT_REJ_TMR_EXP:
1060                 if (opt > LLC_OPT_MAX_REJ_TMR_EXP)
1061                         goto out;
1062                 llc->rej_sent_timer.expire = opt * HZ;
1063                 break;
1064         case LLC_OPT_BUSY_TMR_EXP:
1065                 if (opt > LLC_OPT_MAX_BUSY_TMR_EXP)
1066                         goto out;
1067                 llc->busy_state_timer.expire = opt * HZ;
1068                 break;
1069         case LLC_OPT_TX_WIN:
1070                 if (opt > LLC_OPT_MAX_WIN)
1071                         goto out;
1072                 llc->k = opt;
1073                 break;
1074         case LLC_OPT_RX_WIN:
1075                 if (opt > LLC_OPT_MAX_WIN)
1076                         goto out;
1077                 llc->rw = opt;
1078                 break;
1079         case LLC_OPT_PKTINFO:
1080                 if (opt)
1081                         llc->cmsg_flags |= LLC_CMSG_PKTINFO;
1082                 else
1083                         llc->cmsg_flags &= ~LLC_CMSG_PKTINFO;
1084                 break;
1085         default:
1086                 rc = -ENOPROTOOPT;
1087                 goto out;
1088         }
1089         rc = 0;
1090 out:
1091         release_sock(sk);
1092         return rc;
1093 }
1094
1095 /**
1096  *      llc_ui_getsockopt - get connection specific socket info
1097  *      @sock: Socket to get information from.
1098  *      @level: Socket level user is requesting operations on.
1099  *      @optname: Operation name.
1100  *      @optval: Variable to return operation data in.
1101  *      @optlen: Length of optval.
1102  *
1103  *      Get connection specific socket information.
1104  */
1105 static int llc_ui_getsockopt(struct socket *sock, int level, int optname,
1106                              char __user *optval, int __user *optlen)
1107 {
1108         struct sock *sk = sock->sk;
1109         struct llc_sock *llc = llc_sk(sk);
1110         int val = 0, len = 0, rc = -EINVAL;
1111
1112         lock_sock(sk);
1113         if (unlikely(level != SOL_LLC))
1114                 goto out;
1115         rc = get_user(len, optlen);
1116         if (rc)
1117                 goto out;
1118         rc = -EINVAL;
1119         if (len != sizeof(int))
1120                 goto out;
1121         switch (optname) {
1122         case LLC_OPT_RETRY:
1123                 val = llc->n2;                                  break;
1124         case LLC_OPT_SIZE:
1125                 val = llc->n1;                                  break;
1126         case LLC_OPT_ACK_TMR_EXP:
1127                 val = llc->ack_timer.expire / HZ;               break;
1128         case LLC_OPT_P_TMR_EXP:
1129                 val = llc->pf_cycle_timer.expire / HZ;          break;
1130         case LLC_OPT_REJ_TMR_EXP:
1131                 val = llc->rej_sent_timer.expire / HZ;          break;
1132         case LLC_OPT_BUSY_TMR_EXP:
1133                 val = llc->busy_state_timer.expire / HZ;        break;
1134         case LLC_OPT_TX_WIN:
1135                 val = llc->k;                           break;
1136         case LLC_OPT_RX_WIN:
1137                 val = llc->rw;                          break;
1138         case LLC_OPT_PKTINFO:
1139                 val = (llc->cmsg_flags & LLC_CMSG_PKTINFO) != 0;
1140                 break;
1141         default:
1142                 rc = -ENOPROTOOPT;
1143                 goto out;
1144         }
1145         rc = 0;
1146         if (put_user(len, optlen) || copy_to_user(optval, &val, len))
1147                 rc = -EFAULT;
1148 out:
1149         release_sock(sk);
1150         return rc;
1151 }
1152
1153 static const struct net_proto_family llc_ui_family_ops = {
1154         .family = PF_LLC,
1155         .create = llc_ui_create,
1156         .owner  = THIS_MODULE,
1157 };
1158
1159 static const struct proto_ops llc_ui_ops = {
1160         .family      = PF_LLC,
1161         .owner       = THIS_MODULE,
1162         .release     = llc_ui_release,
1163         .bind        = llc_ui_bind,
1164         .connect     = llc_ui_connect,
1165         .socketpair  = sock_no_socketpair,
1166         .accept      = llc_ui_accept,
1167         .getname     = llc_ui_getname,
1168         .poll        = datagram_poll,
1169         .ioctl       = llc_ui_ioctl,
1170         .listen      = llc_ui_listen,
1171         .shutdown    = llc_ui_shutdown,
1172         .setsockopt  = llc_ui_setsockopt,
1173         .getsockopt  = llc_ui_getsockopt,
1174         .sendmsg     = llc_ui_sendmsg,
1175         .recvmsg     = llc_ui_recvmsg,
1176         .mmap        = sock_no_mmap,
1177         .sendpage    = sock_no_sendpage,
1178 };
1179
1180 static const char llc_proc_err_msg[] __initconst =
1181         KERN_CRIT "LLC: Unable to register the proc_fs entries\n";
1182 static const char llc_sysctl_err_msg[] __initconst =
1183         KERN_CRIT "LLC: Unable to register the sysctl entries\n";
1184 static const char llc_sock_err_msg[] __initconst =
1185         KERN_CRIT "LLC: Unable to register the network family\n";
1186
1187 static int __init llc2_init(void)
1188 {
1189         int rc = proto_register(&llc_proto, 0);
1190
1191         if (rc != 0)
1192                 goto out;
1193
1194         llc_build_offset_table();
1195         llc_station_init();
1196         llc_ui_sap_last_autoport = LLC_SAP_DYN_START;
1197         rc = llc_proc_init();
1198         if (rc != 0) {
1199                 printk(llc_proc_err_msg);
1200                 goto out_unregister_llc_proto;
1201         }
1202         rc = llc_sysctl_init();
1203         if (rc) {
1204                 printk(llc_sysctl_err_msg);
1205                 goto out_proc;
1206         }
1207         rc = sock_register(&llc_ui_family_ops);
1208         if (rc) {
1209                 printk(llc_sock_err_msg);
1210                 goto out_sysctl;
1211         }
1212         llc_add_pack(LLC_DEST_SAP, llc_sap_handler);
1213         llc_add_pack(LLC_DEST_CONN, llc_conn_handler);
1214 out:
1215         return rc;
1216 out_sysctl:
1217         llc_sysctl_exit();
1218 out_proc:
1219         llc_proc_exit();
1220 out_unregister_llc_proto:
1221         proto_unregister(&llc_proto);
1222         goto out;
1223 }
1224
1225 static void __exit llc2_exit(void)
1226 {
1227         llc_station_exit();
1228         llc_remove_pack(LLC_DEST_SAP);
1229         llc_remove_pack(LLC_DEST_CONN);
1230         sock_unregister(PF_LLC);
1231         llc_proc_exit();
1232         llc_sysctl_exit();
1233         proto_unregister(&llc_proto);
1234 }
1235
1236 module_init(llc2_init);
1237 module_exit(llc2_exit);
1238
1239 MODULE_LICENSE("GPL");
1240 MODULE_AUTHOR("Procom 1997, Jay Schullist 2001, Arnaldo C. Melo 2001-2003");
1241 MODULE_DESCRIPTION("IEEE 802.2 PF_LLC support");
1242 MODULE_ALIAS_NETPROTO(PF_LLC);