net/appletalk/ddp.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *      DDP:    An implementation of the AppleTalk DDP protocol for
   4  *              Ethernet 'ELAP'.
   5  *
   6  *              Alan Cox  <alan@lxorguk.ukuu.org.uk>
   7  *
   8  *              With more than a little assistance from
   9  *
  10  *              Wesley Craig <netatalk@umich.edu>
  11  *
  12  *      Fixes:
  13  *              Neil Horman             :       Added missing device ioctls
  14  *              Michael Callahan        :       Made routing work
  15  *              Wesley Craig            :       Fix probing to listen to a
  16  *                                              passed node id.
  17  *              Alan Cox                :       Added send/recvmsg support
  18  *              Alan Cox                :       Moved at. to protinfo in
  19  *                                              socket.
  20  *              Alan Cox                :       Added firewall hooks.
  21  *              Alan Cox                :       Supports new ARPHRD_LOOPBACK
  22  *              Christer Weinigel       :       Routing and /proc fixes.
  23  *              Bradford Johnson        :       LocalTalk.
  24  *              Tom Dyas                :       Module support.
  25  *              Alan Cox                :       Hooks for PPP (based on the
  26  *                                              LocalTalk hook).
  27  *              Alan Cox                :       Posix bits
  28  *              Alan Cox/Mike Freeman   :       Possible fix to NBP problems
  29  *              Bradford Johnson        :       IP-over-DDP (experimental)
  30  *              Jay Schulist            :       Moved IP-over-DDP to its own
  31  *                                              driver file. (ipddp.c & ipddp.h)
  32  *              Jay Schulist            :       Made work as module with
  33  *                                              AppleTalk drivers, cleaned it.
  34  *              Rob Newberry            :       Added proxy AARP and AARP
  35  *                                              procfs, moved probing to AARP
  36  *                                              module.
  37  *              Adrian Sun/
  38  *              Michael Zuelsdorff      :       fix for net.0 packets. don't
  39  *                                              allow illegal ether/tokentalk
  40  *                                              port assignment. we lose a
  41  *                                              valid localtalk port as a
  42  *                                              result.
  43  *              Arnaldo C. de Melo      :       Cleanup, in preparation for
  44  *                                              shared skb support 8)
  45  *              Arnaldo C. de Melo      :       Move proc stuff to atalk_proc.c,
  46  *                                              use seq_file
  47  */
  48
  49 #include <linux/capability.h>
  50 #include <linux/module.h>
  51 #include <linux/if_arp.h>
  52 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
  53 #include <linux/compat.h>
  54 #include <linux/slab.h>
  55 #include <net/datalink.h>
  56 #include <net/psnap.h>
  57 #include <net/sock.h>
  58 #include <net/tcp_states.h>
  59 #include <net/route.h>
  60 #include <net/compat.h>
  61 #include <linux/atalk.h>
  62 #include <linux/highmem.h>
  63
  64 struct datalink_proto *ddp_dl, *aarp_dl;
  65 static const struct proto_ops atalk_dgram_ops;
  66
  67 /**************************************************************************\
  68 *                                                                          *
  69 * Handlers for the socket list.                                            *
  70 *                                                                          *
  71 \**************************************************************************/
  72
  73 HLIST_HEAD(atalk_sockets);
  74 DEFINE_RWLOCK(atalk_sockets_lock);
  75
  76 static inline void __atalk_insert_socket(struct sock *sk)
  77 {
  78         sk_add_node(sk, &atalk_sockets);
  79 }
  80
  81 static inline void atalk_remove_socket(struct sock *sk)
  82 {
  83         write_lock_bh(&atalk_sockets_lock);
  84         sk_del_node_init(sk);
  85         write_unlock_bh(&atalk_sockets_lock);
  86 }
  87
  88 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  89                                         struct atalk_iface *atif)
  90 {
  91         struct sock *def_socket = NULL;
  92         struct sock *s;
  93
  94         read_lock_bh(&atalk_sockets_lock);
  95         sk_for_each(s, &atalk_sockets) {
  96                 struct atalk_sock *at = at_sk(s);
  97
  98                 if (to->sat_port != at->src_port)
  99                         continue;
 100
 101                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 102                     to->sat_addr.s_node == ATADDR_BCAST) {
 103                         if (atif->address.s_node == at->src_node &&
 104                             atif->address.s_net == at->src_net) {
 105                                 /* This socket's address matches the address of the interface
 106                                  * that received the packet -- use it
 107                                  */
 108                                 goto found;
 109                         }
 110
 111                         /* Continue searching for a socket matching the interface address,
 112                          * but use this socket by default if no other one is found
 113                          */
 114                         def_socket = s;
 115                 }
 116
 117                 if (to->sat_addr.s_net == at->src_net &&
 118                     (to->sat_addr.s_node == at->src_node ||
 119                      to->sat_addr.s_node == ATADDR_BCAST ||
 120                      to->sat_addr.s_node == ATADDR_ANYNODE))
 121                         goto found;
 122
 123                 /* XXXX.0 -- we got a request for this router. make sure
 124                  * that the node is appropriately set. */
 125                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 126                     to->sat_addr.s_net != ATADDR_ANYNET &&
 127                     atif->address.s_node == at->src_node) {
 128                         to->sat_addr.s_node = atif->address.s_node;
 129                         goto found;
 130                 }
 131         }
 132         s = def_socket;
 133 found:
 134         read_unlock_bh(&atalk_sockets_lock);
 135         return s;
 136 }
 137
 138 /**
 139  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 140  * @sk: socket to insert in the list if it is not there already
 141  * @sat: address to search for
 142  *
 143  * Try to find a socket matching ADDR in the socket list, if found then return
 144  * it. If not, insert SK into the socket list.
 145  *
 146  * This entire operation must execute atomically.
 147  */
 148 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 149                                                 struct sockaddr_at *sat)
 150 {
 151         struct sock *s;
 152         struct atalk_sock *at;
 153
 154         write_lock_bh(&atalk_sockets_lock);
 155         sk_for_each(s, &atalk_sockets) {
 156                 at = at_sk(s);
 157
 158                 if (at->src_net == sat->sat_addr.s_net &&
 159                     at->src_node == sat->sat_addr.s_node &&
 160                     at->src_port == sat->sat_port)
 161                         goto found;
 162         }
 163         s = NULL;
 164         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 165 found:
 166         write_unlock_bh(&atalk_sockets_lock);
 167         return s;
 168 }
 169
 170 static void atalk_destroy_timer(struct timer_list *t)
 171 {
 172         struct sock *sk = from_timer(sk, t, sk_timer);
 173
 174         if (sk_has_allocations(sk)) {
 175                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 176                 add_timer(&sk->sk_timer);
 177         } else
 178                 sock_put(sk);
 179 }
 180
 181 static inline void atalk_destroy_socket(struct sock *sk)
 182 {
 183         atalk_remove_socket(sk);
 184         skb_queue_purge(&sk->sk_receive_queue);
 185
 186         if (sk_has_allocations(sk)) {
 187                 timer_setup(&sk->sk_timer, atalk_destroy_timer, 0);
 188                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 189                 add_timer(&sk->sk_timer);
 190         } else
 191                 sock_put(sk);
 192 }
 193
 194 /**************************************************************************\
 195 *                                                                          *
 196 * Routing tables for the AppleTalk socket layer.                           *
 197 *                                                                          *
 198 \**************************************************************************/
 199
 200 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 201 struct atalk_route *atalk_routes;
 202 DEFINE_RWLOCK(atalk_routes_lock);
 203
 204 struct atalk_iface *atalk_interfaces;
 205 DEFINE_RWLOCK(atalk_interfaces_lock);
 206
 207 /* For probing devices or in a routerless network */
 208 struct atalk_route atrtr_default;
 209
 210 /* AppleTalk interface control */
 211 /*
 212  * Drop a device. Doesn't drop any of its routes - that is the caller's
 213  * problem. Called when we down the interface or delete the address.
 214  */
 215 static void atif_drop_device(struct net_device *dev)
 216 {
 217         struct atalk_iface **iface = &atalk_interfaces;
 218         struct atalk_iface *tmp;
 219
 220         write_lock_bh(&atalk_interfaces_lock);
 221         while ((tmp = *iface) != NULL) {
 222                 if (tmp->dev == dev) {
 223                         *iface = tmp->next;
 224                         dev_put(dev);
 225                         kfree(tmp);
 226                         dev->atalk_ptr = NULL;
 227                 } else
 228                         iface = &tmp->next;
 229         }
 230         write_unlock_bh(&atalk_interfaces_lock);
 231 }
 232
 233 static struct atalk_iface *atif_add_device(struct net_device *dev,
 234                                            struct atalk_addr *sa)
 235 {
 236         struct atalk_iface *iface = kzalloc(sizeof(*iface), GFP_KERNEL);
 237
 238         if (!iface)
 239                 goto out;
 240
 241         dev_hold(dev);
 242         iface->dev = dev;
 243         dev->atalk_ptr = iface;
 244         iface->address = *sa;
 245         iface->status = 0;
 246
 247         write_lock_bh(&atalk_interfaces_lock);
 248         iface->next = atalk_interfaces;
 249         atalk_interfaces = iface;
 250         write_unlock_bh(&atalk_interfaces_lock);
 251 out:
 252         return iface;
 253 }
 254
 255 /* Perform phase 2 AARP probing on our tentative address */
 256 static int atif_probe_device(struct atalk_iface *atif)
 257 {
 258         int netrange = ntohs(atif->nets.nr_lastnet) -
 259                         ntohs(atif->nets.nr_firstnet) + 1;
 260         int probe_net = ntohs(atif->address.s_net);
 261         int probe_node = atif->address.s_node;
 262         int netct, nodect;
 263
 264         /* Offset the network we start probing with */
 265         if (probe_net == ATADDR_ANYNET) {
 266                 probe_net = ntohs(atif->nets.nr_firstnet);
 267                 if (netrange)
 268                         probe_net += jiffies % netrange;
 269         }
 270         if (probe_node == ATADDR_ANYNODE)
 271                 probe_node = jiffies & 0xFF;
 272
 273         /* Scan the networks */
 274         atif->status |= ATIF_PROBE;
 275         for (netct = 0; netct <= netrange; netct++) {
 276                 /* Sweep the available nodes from a given start */
 277                 atif->address.s_net = htons(probe_net);
 278                 for (nodect = 0; nodect < 256; nodect++) {
 279                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 280                         if (atif->address.s_node > 0 &&
 281                             atif->address.s_node < 254) {
 282                                 /* Probe a proposed address */
 283                                 aarp_probe_network(atif);
 284
 285                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 286                                         atif->status &= ~ATIF_PROBE;
 287                                         return 0;
 288                                 }
 289                         }
 290                         atif->status &= ~ATIF_PROBE_FAIL;
 291                 }
 292                 probe_net++;
 293                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 294                         probe_net = ntohs(atif->nets.nr_firstnet);
 295         }
 296         atif->status &= ~ATIF_PROBE;
 297
 298         return -EADDRINUSE;     /* Network is full... */
 299 }
 300
 301
 302 /* Perform AARP probing for a proxy address */
 303 static int atif_proxy_probe_device(struct atalk_iface *atif,
 304                                    struct atalk_addr *proxy_addr)
 305 {
 306         int netrange = ntohs(atif->nets.nr_lastnet) -
 307                         ntohs(atif->nets.nr_firstnet) + 1;
 308         /* we probe the interface's network */
 309         int probe_net = ntohs(atif->address.s_net);
 310         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 311         int netct, nodect;
 312
 313         /* Offset the network we start probing with */
 314         if (probe_net == ATADDR_ANYNET) {
 315                 probe_net = ntohs(atif->nets.nr_firstnet);
 316                 if (netrange)
 317                         probe_net += jiffies % netrange;
 318         }
 319
 320         if (probe_node == ATADDR_ANYNODE)
 321                 probe_node = jiffies & 0xFF;
 322
 323         /* Scan the networks */
 324         for (netct = 0; netct <= netrange; netct++) {
 325                 /* Sweep the available nodes from a given start */
 326                 proxy_addr->s_net = htons(probe_net);
 327                 for (nodect = 0; nodect < 256; nodect++) {
 328                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 329                         if (proxy_addr->s_node > 0 &&
 330                             proxy_addr->s_node < 254) {
 331                                 /* Tell AARP to probe a proposed address */
 332                                 int ret = aarp_proxy_probe_network(atif,
 333                                                                     proxy_addr);
 334
 335                                 if (ret != -EADDRINUSE)
 336                                         return ret;
 337                         }
 338                 }
 339                 probe_net++;
 340                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 341                         probe_net = ntohs(atif->nets.nr_firstnet);
 342         }
 343
 344         return -EADDRINUSE;     /* Network is full... */
 345 }
 346
 347
 348 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 349 {
 350         struct atalk_iface *iface = dev->atalk_ptr;
 351         return iface ? &iface->address : NULL;
 352 }
 353
 354 static struct atalk_addr *atalk_find_primary(void)
 355 {
 356         struct atalk_iface *fiface = NULL;
 357         struct atalk_addr *retval;
 358         struct atalk_iface *iface;
 359
 360         /*
 361          * Return a point-to-point interface only if
 362          * there is no non-ptp interface available.
 363          */
 364         read_lock_bh(&atalk_interfaces_lock);
 365         for (iface = atalk_interfaces; iface; iface = iface->next) {
 366                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 367                         fiface = iface;
 368                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 369                         retval = &iface->address;
 370                         goto out;
 371                 }
 372         }
 373
 374         if (fiface)
 375                 retval = &fiface->address;
 376         else if (atalk_interfaces)
 377                 retval = &atalk_interfaces->address;
 378         else
 379                 retval = NULL;
 380 out:
 381         read_unlock_bh(&atalk_interfaces_lock);
 382         return retval;
 383 }
 384
 385 /*
 386  * Find a match for 'any network' - ie any of our interfaces with that
 387  * node number will do just nicely.
 388  */
 389 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 390 {
 391         struct atalk_iface *iface = dev->atalk_ptr;
 392
 393         if (!iface || iface->status & ATIF_PROBE)
 394                 goto out_err;
 395
 396         if (node != ATADDR_BCAST &&
 397             iface->address.s_node != node &&
 398             node != ATADDR_ANYNODE)
 399                 goto out_err;
 400 out:
 401         return iface;
 402 out_err:
 403         iface = NULL;
 404         goto out;
 405 }
 406
 407 /* Find a match for a specific network:node pair */
 408 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 409 {
 410         struct atalk_iface *iface;
 411
 412         read_lock_bh(&atalk_interfaces_lock);
 413         for (iface = atalk_interfaces; iface; iface = iface->next) {
 414                 if ((node == ATADDR_BCAST ||
 415                      node == ATADDR_ANYNODE ||
 416                      iface->address.s_node == node) &&
 417                     iface->address.s_net == net &&
 418                     !(iface->status & ATIF_PROBE))
 419                         break;
 420
 421                 /* XXXX.0 -- net.0 returns the iface associated with net */
 422                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 423                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 424                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 425                         break;
 426         }
 427         read_unlock_bh(&atalk_interfaces_lock);
 428         return iface;
 429 }
 430
 431
 432 /*
 433  * Find a route for an AppleTalk packet. This ought to get cached in
 434  * the socket (later on...). We know about host routes and the fact
 435  * that a route must be direct to broadcast.
 436  */
 437 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 438 {
 439         /*
 440          * we must search through all routes unless we find a
 441          * host route, because some host routes might overlap
 442          * network routes
 443          */
 444         struct atalk_route *net_route = NULL;
 445         struct atalk_route *r;
 446
 447         read_lock_bh(&atalk_routes_lock);
 448         for (r = atalk_routes; r; r = r->next) {
 449                 if (!(r->flags & RTF_UP))
 450                         continue;
 451
 452                 if (r->target.s_net == target->s_net) {
 453                         if (r->flags & RTF_HOST) {
 454                                 /*
 455                                  * if this host route is for the target,
 456                                  * the we're done
 457                                  */
 458                                 if (r->target.s_node == target->s_node)
 459                                         goto out;
 460                         } else
 461                                 /*
 462                                  * this route will work if there isn't a
 463                                  * direct host route, so cache it
 464                                  */
 465                                 net_route = r;
 466                 }
 467         }
 468
 469         /*
 470          * if we found a network route but not a direct host
 471          * route, then return it
 472          */
 473         if (net_route)
 474                 r = net_route;
 475         else if (atrtr_default.dev)
 476                 r = &atrtr_default;
 477         else /* No route can be found */
 478                 r = NULL;
 479 out:
 480         read_unlock_bh(&atalk_routes_lock);
 481         return r;
 482 }
 483
 484
 485 /*
 486  * Given an AppleTalk network, find the device to use. This can be
 487  * a simple lookup.
 488  */
 489 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 490 {
 491         struct atalk_route *atr = atrtr_find(sa);
 492         return atr ? atr->dev : NULL;
 493 }
 494
 495 /* Set up a default router */
 496 static void atrtr_set_default(struct net_device *dev)
 497 {
 498         atrtr_default.dev            = dev;
 499         atrtr_default.flags          = RTF_UP;
 500         atrtr_default.gateway.s_net  = htons(0);
 501         atrtr_default.gateway.s_node = 0;
 502 }
 503
 504 /*
 505  * Add a router. Basically make sure it looks valid and stuff the
 506  * entry in the list. While it uses netranges we always set them to one
 507  * entry to work like netatalk.
 508  */
 509 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 510 {
 511         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 512         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 513         struct atalk_route *rt;
 514         struct atalk_iface *iface, *riface;
 515         int retval = -EINVAL;
 516
 517         /*
 518          * Fixme: Raise/Lower a routing change semaphore for these
 519          * operations.
 520          */
 521
 522         /* Validate the request */
 523         if (ta->sat_family != AF_APPLETALK ||
 524             (!devhint && ga->sat_family != AF_APPLETALK))
 525                 goto out;
 526
 527         /* Now walk the routing table and make our decisions */
 528         write_lock_bh(&atalk_routes_lock);
 529         for (rt = atalk_routes; rt; rt = rt->next) {
 530                 if (r->rt_flags != rt->flags)
 531                         continue;
 532
 533                 if (ta->sat_addr.s_net == rt->target.s_net) {
 534                         if (!(rt->flags & RTF_HOST))
 535                                 break;
 536                         if (ta->sat_addr.s_node == rt->target.s_node)
 537                                 break;
 538                 }
 539         }
 540
 541         if (!devhint) {
 542                 riface = NULL;
 543
 544                 read_lock_bh(&atalk_interfaces_lock);
 545                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 546                         if (!riface &&
 547                             ntohs(ga->sat_addr.s_net) >=
 548                                         ntohs(iface->nets.nr_firstnet) &&
 549                             ntohs(ga->sat_addr.s_net) <=
 550                                         ntohs(iface->nets.nr_lastnet))
 551                                 riface = iface;
 552
 553                         if (ga->sat_addr.s_net == iface->address.s_net &&
 554                             ga->sat_addr.s_node == iface->address.s_node)
 555                                 riface = iface;
 556                 }
 557                 read_unlock_bh(&atalk_interfaces_lock);
 558
 559                 retval = -ENETUNREACH;
 560                 if (!riface)
 561                         goto out_unlock;
 562
 563                 devhint = riface->dev;
 564         }
 565
 566         if (!rt) {
 567                 rt = kzalloc(sizeof(*rt), GFP_ATOMIC);
 568
 569                 retval = -ENOBUFS;
 570                 if (!rt)
 571                         goto out_unlock;
 572
 573                 rt->next = atalk_routes;
 574                 atalk_routes = rt;
 575         }
 576
 577         /* Fill in the routing entry */
 578         rt->target  = ta->sat_addr;
 579         dev_hold(devhint);
 580         rt->dev     = devhint;
 581         rt->flags   = r->rt_flags;
 582         rt->gateway = ga->sat_addr;
 583
 584         retval = 0;
 585 out_unlock:
 586         write_unlock_bh(&atalk_routes_lock);
 587 out:
 588         return retval;
 589 }
 590
 591 /* Delete a route. Find it and discard it */
 592 static int atrtr_delete(struct atalk_addr *addr)
 593 {
 594         struct atalk_route **r = &atalk_routes;
 595         int retval = 0;
 596         struct atalk_route *tmp;
 597
 598         write_lock_bh(&atalk_routes_lock);
 599         while ((tmp = *r) != NULL) {
 600                 if (tmp->target.s_net == addr->s_net &&
 601                     (!(tmp->flags&RTF_GATEWAY) ||
 602                      tmp->target.s_node == addr->s_node)) {
 603                         *r = tmp->next;
 604                         dev_put(tmp->dev);
 605                         kfree(tmp);
 606                         goto out;
 607                 }
 608                 r = &tmp->next;
 609         }
 610         retval = -ENOENT;
 611 out:
 612         write_unlock_bh(&atalk_routes_lock);
 613         return retval;
 614 }
 615
 616 /*
 617  * Called when a device is downed. Just throw away any routes
 618  * via it.
 619  */
 620 static void atrtr_device_down(struct net_device *dev)
 621 {
 622         struct atalk_route **r = &atalk_routes;
 623         struct atalk_route *tmp;
 624
 625         write_lock_bh(&atalk_routes_lock);
 626         while ((tmp = *r) != NULL) {
 627                 if (tmp->dev == dev) {
 628                         *r = tmp->next;
 629                         dev_put(dev);
 630                         kfree(tmp);
 631                 } else
 632                         r = &tmp->next;
 633         }
 634         write_unlock_bh(&atalk_routes_lock);
 635
 636         if (atrtr_default.dev == dev)
 637                 atrtr_set_default(NULL);
 638 }
 639
 640 /* Actually down the interface */
 641 static inline void atalk_dev_down(struct net_device *dev)
 642 {
 643         atrtr_device_down(dev); /* Remove all routes for the device */
 644         aarp_device_down(dev);  /* Remove AARP entries for the device */
 645         atif_drop_device(dev);  /* Remove the device */
 646 }
 647
 648 /*
 649  * A device event has occurred. Watch for devices going down and
 650  * delete our use of them (iface and route).
 651  */
 652 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 653                             void *ptr)
 654 {
 655         struct net_device *dev = netdev_notifier_info_to_dev(ptr);
 656
 657         if (!net_eq(dev_net(dev), &init_net))
 658                 return NOTIFY_DONE;
 659
 660         if (event == NETDEV_DOWN)
 661                 /* Discard any use of this */
 662                 atalk_dev_down(dev);
 663
 664         return NOTIFY_DONE;
 665 }
 666
 667 /* ioctl calls. Shouldn't even need touching */
 668 /* Device configuration ioctl calls */
 669 static int atif_ioctl(int cmd, void __user *arg)
 670 {
 671         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 672         struct ifreq atreq;
 673         struct atalk_netrange *nr;
 674         struct sockaddr_at *sa;
 675         struct net_device *dev;
 676         struct atalk_iface *atif;
 677         int ct;
 678         int limit;
 679         struct rtentry rtdef;
 680         int add_route;
 681
 682         if (get_user_ifreq(&atreq, NULL, arg))
 683                 return -EFAULT;
 684
 685         dev = __dev_get_by_name(&init_net, atreq.ifr_name);
 686         if (!dev)
 687                 return -ENODEV;
 688
 689         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 690         atif = atalk_find_dev(dev);
 691
 692         switch (cmd) {
 693         case SIOCSIFADDR:
 694                 if (!capable(CAP_NET_ADMIN))
 695                         return -EPERM;
 696                 if (sa->sat_family != AF_APPLETALK)
 697                         return -EINVAL;
 698                 if (dev->type != ARPHRD_ETHER &&
 699                     dev->type != ARPHRD_LOOPBACK &&
 700                     dev->type != ARPHRD_LOCALTLK &&
 701                     dev->type != ARPHRD_PPP)
 702                         return -EPROTONOSUPPORT;
 703
 704                 nr = (struct atalk_netrange *)&sa->sat_zero[0];
 705                 add_route = 1;
 706
 707                 /*
 708                  * if this is a point-to-point iface, and we already
 709                  * have an iface for this AppleTalk address, then we
 710                  * should not add a route
 711                  */
 712                 if ((dev->flags & IFF_POINTOPOINT) &&
 713                     atalk_find_interface(sa->sat_addr.s_net,
 714                                          sa->sat_addr.s_node)) {
 715                         printk(KERN_DEBUG "AppleTalk: point-to-point "
 716                                "interface added with "
 717                                "existing address\n");
 718                         add_route = 0;
 719                 }
 720
 721                 /*
 722                  * Phase 1 is fine on LocalTalk but we don't do
 723                  * EtherTalk phase 1. Anyone wanting to add it, go ahead.
 724                  */
 725                 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 726                         return -EPROTONOSUPPORT;
 727                 if (sa->sat_addr.s_node == ATADDR_BCAST ||
 728                     sa->sat_addr.s_node == 254)
 729                         return -EINVAL;
 730                 if (atif) {
 731                         /* Already setting address */
 732                         if (atif->status & ATIF_PROBE)
 733                                 return -EBUSY;
 734
 735                         atif->address.s_net  = sa->sat_addr.s_net;
 736                         atif->address.s_node = sa->sat_addr.s_node;
 737                         atrtr_device_down(dev); /* Flush old routes */
 738                 } else {
 739                         atif = atif_add_device(dev, &sa->sat_addr);
 740                         if (!atif)
 741                                 return -ENOMEM;
 742                 }
 743                 atif->nets = *nr;
 744
 745                 /*
 746                  * Check if the chosen address is used. If so we
 747                  * error and atalkd will try another.
 748                  */
 749
 750                 if (!(dev->flags & IFF_LOOPBACK) &&
 751                     !(dev->flags & IFF_POINTOPOINT) &&
 752                     atif_probe_device(atif) < 0) {
 753                         atif_drop_device(dev);
 754                         return -EADDRINUSE;
 755                 }
 756
 757                 /* Hey it worked - add the direct routes */
 758                 sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 759                 sa->sat_family = AF_APPLETALK;
 760                 sa->sat_addr.s_net  = atif->address.s_net;
 761                 sa->sat_addr.s_node = atif->address.s_node;
 762                 sa = (struct sockaddr_at *)&rtdef.rt_dst;
 763                 rtdef.rt_flags = RTF_UP;
 764                 sa->sat_family = AF_APPLETALK;
 765                 sa->sat_addr.s_node = ATADDR_ANYNODE;
 766                 if (dev->flags & IFF_LOOPBACK ||
 767                     dev->flags & IFF_POINTOPOINT)
 768                         rtdef.rt_flags |= RTF_HOST;
 769
 770                 /* Routerless initial state */
 771                 if (nr->nr_firstnet == htons(0) &&
 772                     nr->nr_lastnet == htons(0xFFFE)) {
 773                         sa->sat_addr.s_net = atif->address.s_net;
 774                         atrtr_create(&rtdef, dev);
 775                         atrtr_set_default(dev);
 776                 } else {
 777                         limit = ntohs(nr->nr_lastnet);
 778                         if (limit - ntohs(nr->nr_firstnet) > 4096) {
 779                                 printk(KERN_WARNING "Too many routes/"
 780                                        "iface.\n");
 781                                 return -EINVAL;
 782                         }
 783                         if (add_route)
 784                                 for (ct = ntohs(nr->nr_firstnet);
 785                                      ct <= limit; ct++) {
 786                                         sa->sat_addr.s_net = htons(ct);
 787                                         atrtr_create(&rtdef, dev);
 788                                 }
 789                 }
 790                 dev_mc_add_global(dev, aarp_mcast);
 791                 return 0;
 792
 793         case SIOCGIFADDR:
 794                 if (!atif)
 795                         return -EADDRNOTAVAIL;
 796
 797                 sa->sat_family = AF_APPLETALK;
 798                 sa->sat_addr = atif->address;
 799                 break;
 800
 801         case SIOCGIFBRDADDR:
 802                 if (!atif)
 803                         return -EADDRNOTAVAIL;
 804
 805                 sa->sat_family = AF_APPLETALK;
 806                 sa->sat_addr.s_net = atif->address.s_net;
 807                 sa->sat_addr.s_node = ATADDR_BCAST;
 808                 break;
 809
 810         case SIOCATALKDIFADDR:
 811         case SIOCDIFADDR:
 812                 if (!capable(CAP_NET_ADMIN))
 813                         return -EPERM;
 814                 if (sa->sat_family != AF_APPLETALK)
 815                         return -EINVAL;
 816                 atalk_dev_down(dev);
 817                 break;
 818
 819         case SIOCSARP:
 820                 if (!capable(CAP_NET_ADMIN))
 821                         return -EPERM;
 822                 if (sa->sat_family != AF_APPLETALK)
 823                         return -EINVAL;
 824                 /*
 825                  * for now, we only support proxy AARP on ELAP;
 826                  * we should be able to do it for LocalTalk, too.
 827                  */
 828                 if (dev->type != ARPHRD_ETHER)
 829                         return -EPROTONOSUPPORT;
 830
 831                 /*
 832                  * atif points to the current interface on this network;
 833                  * we aren't concerned about its current status (at
 834                  * least for now), but it has all the settings about
 835                  * the network we're going to probe. Consequently, it
 836                  * must exist.
 837                  */
 838                 if (!atif)
 839                         return -EADDRNOTAVAIL;
 840
 841                 nr = (struct atalk_netrange *)&(atif->nets);
 842                 /*
 843                  * Phase 1 is fine on Localtalk but we don't do
 844                  * Ethertalk phase 1. Anyone wanting to add it, go ahead.
 845                  */
 846                 if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 847                         return -EPROTONOSUPPORT;
 848
 849                 if (sa->sat_addr.s_node == ATADDR_BCAST ||
 850                     sa->sat_addr.s_node == 254)
 851                         return -EINVAL;
 852
 853                 /*
 854                  * Check if the chosen address is used. If so we
 855                  * error and ATCP will try another.
 856                  */
 857                 if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 858                         return -EADDRINUSE;
 859
 860                 /*
 861                  * We now have an address on the local network, and
 862                  * the AARP code will defend it for us until we take it
 863                  * down. We don't set up any routes right now, because
 864                  * ATCP will install them manually via SIOCADDRT.
 865                  */
 866                 break;
 867
 868         case SIOCDARP:
 869                 if (!capable(CAP_NET_ADMIN))
 870                         return -EPERM;
 871                 if (sa->sat_family != AF_APPLETALK)
 872                         return -EINVAL;
 873                 if (!atif)
 874                         return -EADDRNOTAVAIL;
 875
 876                 /* give to aarp module to remove proxy entry */
 877                 aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 878                 return 0;
 879         }
 880
 881         return put_user_ifreq(&atreq, arg);
 882 }
 883
 884 static int atrtr_ioctl_addrt(struct rtentry *rt)
 885 {
 886         struct net_device *dev = NULL;
 887
 888         if (rt->rt_dev) {
 889                 char name[IFNAMSIZ];
 890
 891                 if (copy_from_user(name, rt->rt_dev, IFNAMSIZ-1))
 892                         return -EFAULT;
 893                 name[IFNAMSIZ-1] = '\0';
 894
 895                 dev = __dev_get_by_name(&init_net, name);
 896                 if (!dev)
 897                         return -ENODEV;
 898         }
 899         return atrtr_create(rt, dev);
 900 }
 901
 902 /* Routing ioctl() calls */
 903 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 904 {
 905         struct rtentry rt;
 906
 907         if (copy_from_user(&rt, arg, sizeof(rt)))
 908                 return -EFAULT;
 909
 910         switch (cmd) {
 911         case SIOCDELRT:
 912                 if (rt.rt_dst.sa_family != AF_APPLETALK)
 913                         return -EINVAL;
 914                 return atrtr_delete(&((struct sockaddr_at *)
 915                                       &rt.rt_dst)->sat_addr);
 916
 917         case SIOCADDRT:
 918                 return atrtr_ioctl_addrt(&rt);
 919         }
 920         return -EINVAL;
 921 }
 922
 923 /**************************************************************************\
 924 *                                                                          *
 925 * Handling for system calls applied via the various interfaces to an       *
 926 * AppleTalk socket object.                                                 *
 927 *                                                                          *
 928 \**************************************************************************/
 929
 930 /*
 931  * Checksum: This is 'optional'. It's quite likely also a good
 932  * candidate for assembler hackery 8)
 933  */
 934 static unsigned long atalk_sum_partial(const unsigned char *data,
 935                                        int len, unsigned long sum)
 936 {
 937         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 938         while (len--) {
 939                 sum += *data++;
 940                 sum = rol16(sum, 1);
 941         }
 942         return sum;
 943 }
 944
 945 /*  Checksum skb data --  similar to skb_checksum  */
 946 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 947                                    int len, unsigned long sum)
 948 {
 949         int start = skb_headlen(skb);
 950         struct sk_buff *frag_iter;
 951         int i, copy;
 952
 953         /* checksum stuff in header space */
 954         if ((copy = start - offset) > 0) {
 955                 if (copy > len)
 956                         copy = len;
 957                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 958                 if ((len -= copy) == 0)
 959                         return sum;
 960
 961                 offset += copy;
 962         }
 963
 964         /* checksum stuff in frags */
 965         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 966                 int end;
 967                 const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 968                 WARN_ON(start > offset + len);
 969
 970                 end = start + skb_frag_size(frag);
 971                 if ((copy = end - offset) > 0) {
 972                         u8 *vaddr;
 973
 974                         if (copy > len)
 975                                 copy = len;
 976                         vaddr = kmap_atomic(skb_frag_page(frag));
 977                         sum = atalk_sum_partial(vaddr + skb_frag_off(frag) +
 978                                                 offset - start, copy, sum);
 979                         kunmap_atomic(vaddr);
 980
 981                         if (!(len -= copy))
 982                                 return sum;
 983                         offset += copy;
 984                 }
 985                 start = end;
 986         }
 987
 988         skb_walk_frags(skb, frag_iter) {
 989                 int end;
 990
 991                 WARN_ON(start > offset + len);
 992
 993                 end = start + frag_iter->len;
 994                 if ((copy = end - offset) > 0) {
 995                         if (copy > len)
 996                                 copy = len;
 997                         sum = atalk_sum_skb(frag_iter, offset - start,
 998                                             copy, sum);
 999                         if ((len -= copy) == 0)
1000                                 return sum;
1001                         offset += copy;
1002                 }
1003                 start = end;
1004         }
1005
1006         BUG_ON(len > 0);
1007
1008         return sum;
1009 }
1010
1011 static __be16 atalk_checksum(const struct sk_buff *skb, int len)
1012 {
1013         unsigned long sum;
1014
1015         /* skip header 4 bytes */
1016         sum = atalk_sum_skb(skb, 4, len-4, 0);
1017
1018         /* Use 0xFFFF for 0. 0 itself means none */
1019         return sum ? htons((unsigned short)sum) : htons(0xFFFF);
1020 }
1021
1022 static struct proto ddp_proto = {
1023         .name     = "DDP",
1024         .owner    = THIS_MODULE,
1025         .obj_size = sizeof(struct atalk_sock),
1026 };
1027
1028 /*
1029  * Create a socket. Initialise the socket, blank the addresses
1030  * set the state.
1031  */
1032 static int atalk_create(struct net *net, struct socket *sock, int protocol,
1033                         int kern)
1034 {
1035         struct sock *sk;
1036         int rc = -ESOCKTNOSUPPORT;
1037
1038         if (!net_eq(net, &init_net))
1039                 return -EAFNOSUPPORT;
1040
1041         /*
1042          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1043          * and gives you the full ELAP frame. Should be handy for CAP 8)
1044          */
1045         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1046                 goto out;
1047
1048         rc = -EPERM;
1049         if (sock->type == SOCK_RAW && !kern && !capable(CAP_NET_RAW))
1050                 goto out;
1051
1052         rc = -ENOMEM;
1053         sk = sk_alloc(net, PF_APPLETALK, GFP_KERNEL, &ddp_proto, kern);
1054         if (!sk)
1055                 goto out;
1056         rc = 0;
1057         sock->ops = &atalk_dgram_ops;
1058         sock_init_data(sock, sk);
1059
1060         /* Checksums on by default */
1061         sock_set_flag(sk, SOCK_ZAPPED);
1062 out:
1063         return rc;
1064 }
1065
1066 /* Free a socket. No work needed */
1067 static int atalk_release(struct socket *sock)
1068 {
1069         struct sock *sk = sock->sk;
1070
1071         if (sk) {
1072                 sock_hold(sk);
1073                 lock_sock(sk);
1074
1075                 sock_orphan(sk);
1076                 sock->sk = NULL;
1077                 atalk_destroy_socket(sk);
1078
1079                 release_sock(sk);
1080                 sock_put(sk);
1081         }
1082         return 0;
1083 }
1084
1085 /**
1086  * atalk_pick_and_bind_port - Pick a source port when one is not given
1087  * @sk: socket to insert into the tables
1088  * @sat: address to search for
1089  *
1090  * Pick a source port when one is not given. If we can find a suitable free
1091  * one, we insert the socket into the tables using it.
1092  *
1093  * This whole operation must be atomic.
1094  */
1095 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1096 {
1097         int retval;
1098
1099         write_lock_bh(&atalk_sockets_lock);
1100
1101         for (sat->sat_port = ATPORT_RESERVED;
1102              sat->sat_port < ATPORT_LAST;
1103              sat->sat_port++) {
1104                 struct sock *s;
1105
1106                 sk_for_each(s, &atalk_sockets) {
1107                         struct atalk_sock *at = at_sk(s);
1108
1109                         if (at->src_net == sat->sat_addr.s_net &&
1110                             at->src_node == sat->sat_addr.s_node &&
1111                             at->src_port == sat->sat_port)
1112                                 goto try_next_port;
1113                 }
1114
1115                 /* Wheee, it's free, assign and insert. */
1116                 __atalk_insert_socket(sk);
1117                 at_sk(sk)->src_port = sat->sat_port;
1118                 retval = 0;
1119                 goto out;
1120
1121 try_next_port:;
1122         }
1123
1124         retval = -EBUSY;
1125 out:
1126         write_unlock_bh(&atalk_sockets_lock);
1127         return retval;
1128 }
1129
1130 static int atalk_autobind(struct sock *sk)
1131 {
1132         struct atalk_sock *at = at_sk(sk);
1133         struct sockaddr_at sat;
1134         struct atalk_addr *ap = atalk_find_primary();
1135         int n = -EADDRNOTAVAIL;
1136
1137         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1138                 goto out;
1139
1140         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1141         at->src_node = sat.sat_addr.s_node = ap->s_node;
1142
1143         n = atalk_pick_and_bind_port(sk, &sat);
1144         if (!n)
1145                 sock_reset_flag(sk, SOCK_ZAPPED);
1146 out:
1147         return n;
1148 }
1149
1150 /* Set the address 'our end' of the connection */
1151 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1152 {
1153         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1154         struct sock *sk = sock->sk;
1155         struct atalk_sock *at = at_sk(sk);
1156         int err;
1157
1158         if (!sock_flag(sk, SOCK_ZAPPED) ||
1159             addr_len != sizeof(struct sockaddr_at))
1160                 return -EINVAL;
1161
1162         if (addr->sat_family != AF_APPLETALK)
1163                 return -EAFNOSUPPORT;
1164
1165         lock_sock(sk);
1166         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1167                 struct atalk_addr *ap = atalk_find_primary();
1168
1169                 err = -EADDRNOTAVAIL;
1170                 if (!ap)
1171                         goto out;
1172
1173                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1174                 at->src_node = addr->sat_addr.s_node = ap->s_node;
1175         } else {
1176                 err = -EADDRNOTAVAIL;
1177                 if (!atalk_find_interface(addr->sat_addr.s_net,
1178                                           addr->sat_addr.s_node))
1179                         goto out;
1180
1181                 at->src_net  = addr->sat_addr.s_net;
1182                 at->src_node = addr->sat_addr.s_node;
1183         }
1184
1185         if (addr->sat_port == ATADDR_ANYPORT) {
1186                 err = atalk_pick_and_bind_port(sk, addr);
1187
1188                 if (err < 0)
1189                         goto out;
1190         } else {
1191                 at->src_port = addr->sat_port;
1192
1193                 err = -EADDRINUSE;
1194                 if (atalk_find_or_insert_socket(sk, addr))
1195                         goto out;
1196         }
1197
1198         sock_reset_flag(sk, SOCK_ZAPPED);
1199         err = 0;
1200 out:
1201         release_sock(sk);
1202         return err;
1203 }
1204
1205 /* Set the address we talk to */
1206 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1207                          int addr_len, int flags)
1208 {
1209         struct sock *sk = sock->sk;
1210         struct atalk_sock *at = at_sk(sk);
1211         struct sockaddr_at *addr;
1212         int err;
1213
1214         sk->sk_state   = TCP_CLOSE;
1215         sock->state = SS_UNCONNECTED;
1216
1217         if (addr_len != sizeof(*addr))
1218                 return -EINVAL;
1219
1220         addr = (struct sockaddr_at *)uaddr;
1221
1222         if (addr->sat_family != AF_APPLETALK)
1223                 return -EAFNOSUPPORT;
1224
1225         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1226             !sock_flag(sk, SOCK_BROADCAST)) {
1227 #if 1
1228                 pr_warn("atalk_connect: %s is broken and did not set SO_BROADCAST.\n",
1229                         current->comm);
1230 #else
1231                 return -EACCES;
1232 #endif
1233         }
1234
1235         lock_sock(sk);
1236         err = -EBUSY;
1237         if (sock_flag(sk, SOCK_ZAPPED))
1238                 if (atalk_autobind(sk) < 0)
1239                         goto out;
1240
1241         err = -ENETUNREACH;
1242         if (!atrtr_get_dev(&addr->sat_addr))
1243                 goto out;
1244
1245         at->dest_port = addr->sat_port;
1246         at->dest_net  = addr->sat_addr.s_net;
1247         at->dest_node = addr->sat_addr.s_node;
1248
1249         sock->state  = SS_CONNECTED;
1250         sk->sk_state = TCP_ESTABLISHED;
1251         err = 0;
1252 out:
1253         release_sock(sk);
1254         return err;
1255 }
1256
1257 /*
1258  * Find the name of an AppleTalk socket. Just copy the right
1259  * fields into the sockaddr.
1260  */
1261 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1262                          int peer)
1263 {
1264         struct sockaddr_at sat;
1265         struct sock *sk = sock->sk;
1266         struct atalk_sock *at = at_sk(sk);
1267         int err;
1268
1269         lock_sock(sk);
1270         err = -ENOBUFS;
1271         if (sock_flag(sk, SOCK_ZAPPED))
1272                 if (atalk_autobind(sk) < 0)
1273                         goto out;
1274
1275         memset(&sat, 0, sizeof(sat));
1276
1277         if (peer) {
1278                 err = -ENOTCONN;
1279                 if (sk->sk_state != TCP_ESTABLISHED)
1280                         goto out;
1281
1282                 sat.sat_addr.s_net  = at->dest_net;
1283                 sat.sat_addr.s_node = at->dest_node;
1284                 sat.sat_port        = at->dest_port;
1285         } else {
1286                 sat.sat_addr.s_net  = at->src_net;
1287                 sat.sat_addr.s_node = at->src_node;
1288                 sat.sat_port        = at->src_port;
1289         }
1290
1291         sat.sat_family = AF_APPLETALK;
1292         memcpy(uaddr, &sat, sizeof(sat));
1293         err = sizeof(struct sockaddr_at);
1294
1295 out:
1296         release_sock(sk);
1297         return err;
1298 }
1299
1300 static int atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1301                               struct ddpehdr *ddp, __u16 len_hops, int origlen)
1302 {
1303         struct atalk_route *rt;
1304         struct atalk_addr ta;
1305
1306         /*
1307          * Don't route multicast, etc., packets, or packets sent to "this
1308          * network"
1309          */
1310         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1311                 /*
1312                  * FIXME:
1313                  *
1314                  * Can it ever happen that a packet is from a PPP iface and
1315                  * needs to be broadcast onto the default network?
1316                  */
1317                 if (dev->type == ARPHRD_PPP)
1318                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1319                                           "packet received from PPP iface\n");
1320                 goto free_it;
1321         }
1322
1323         ta.s_net  = ddp->deh_dnet;
1324         ta.s_node = ddp->deh_dnode;
1325
1326         /* Route the packet */
1327         rt = atrtr_find(&ta);
1328         /* increment hops count */
1329         len_hops += 1 << 10;
1330         if (!rt || !(len_hops & (15 << 10)))
1331                 goto free_it;
1332
1333         /* FIXME: use skb->cb to be able to use shared skbs */
1334
1335         /*
1336          * Route goes through another gateway, so set the target to the
1337          * gateway instead.
1338          */
1339
1340         if (rt->flags & RTF_GATEWAY) {
1341                 ta.s_net  = rt->gateway.s_net;
1342                 ta.s_node = rt->gateway.s_node;
1343         }
1344
1345         /* Fix up skb->len field */
1346         skb_trim(skb, min_t(unsigned int, origlen,
1347                             (rt->dev->hard_header_len +
1348                              ddp_dl->header_length + (len_hops & 1023))));
1349
1350         /* FIXME: use skb->cb to be able to use shared skbs */
1351         ddp->deh_len_hops = htons(len_hops);
1352
1353         /*
1354          * Send the buffer onwards
1355          *
1356          * Now we must always be careful. If it's come from LocalTalk to
1357          * EtherTalk it might not fit
1358          *
1359          * Order matters here: If a packet has to be copied to make a new
1360          * headroom (rare hopefully) then it won't need unsharing.
1361          *
1362          * Note. ddp-> becomes invalid at the realloc.
1363          */
1364         if (skb_headroom(skb) < 22) {
1365                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1366                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1367                 kfree_skb(skb);
1368                 skb = nskb;
1369         } else
1370                 skb = skb_unshare(skb, GFP_ATOMIC);
1371
1372         /*
1373          * If the buffer didn't vanish into the lack of space bitbucket we can
1374          * send it.
1375          */
1376         if (skb == NULL)
1377                 goto drop;
1378
1379         if (aarp_send_ddp(rt->dev, skb, &ta, NULL) == NET_XMIT_DROP)
1380                 return NET_RX_DROP;
1381         return NET_RX_SUCCESS;
1382 free_it:
1383         kfree_skb(skb);
1384 drop:
1385         return NET_RX_DROP;
1386 }
1387
1388 /**
1389  *      atalk_rcv - Receive a packet (in skb) from device dev
1390  *      @skb: packet received
1391  *      @dev: network device where the packet comes from
1392  *      @pt: packet type
1393  *      @orig_dev: the original receive net device
1394  *
1395  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1396  *      decoder, and on entry skb->transport_header is the DDP header, skb->len
1397  *      is the DDP header, skb->len is the DDP length. The physical headers
1398  *      have been extracted. PPP should probably pass frames marked as for this
1399  *      layer.  [ie ARPHRD_ETHERTALK]
1400  */
1401 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1402                      struct packet_type *pt, struct net_device *orig_dev)
1403 {
1404         struct ddpehdr *ddp;
1405         struct sock *sock;
1406         struct atalk_iface *atif;
1407         struct sockaddr_at tosat;
1408         int origlen;
1409         __u16 len_hops;
1410
1411         if (!net_eq(dev_net(dev), &init_net))
1412                 goto drop;
1413
1414         /* Don't mangle buffer if shared */
1415         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1416                 goto out;
1417
1418         /* Size check and make sure header is contiguous */
1419         if (!pskb_may_pull(skb, sizeof(*ddp)))
1420                 goto drop;
1421
1422         ddp = ddp_hdr(skb);
1423
1424         len_hops = ntohs(ddp->deh_len_hops);
1425
1426         /* Trim buffer in case of stray trailing data */
1427         origlen = skb->len;
1428         skb_trim(skb, min_t(unsigned int, skb->len, len_hops & 1023));
1429
1430         /*
1431          * Size check to see if ddp->deh_len was crap
1432          * (Otherwise we'll detonate most spectacularly
1433          * in the middle of atalk_checksum() or recvmsg()).
1434          */
1435         if (skb->len < sizeof(*ddp) || skb->len < (len_hops & 1023)) {
1436                 pr_debug("AppleTalk: dropping corrupted frame (deh_len=%u, "
1437                          "skb->len=%u)\n", len_hops & 1023, skb->len);
1438                 goto drop;
1439         }
1440
1441         /*
1442          * Any checksums. Note we don't do htons() on this == is assumed to be
1443          * valid for net byte orders all over the networking code...
1444          */
1445         if (ddp->deh_sum &&
1446             atalk_checksum(skb, len_hops & 1023) != ddp->deh_sum)
1447                 /* Not a valid AppleTalk frame - dustbin time */
1448                 goto drop;
1449
1450         /* Check the packet is aimed at us */
1451         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1452                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1453         else
1454                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1455
1456         if (!atif) {
1457                 /* Not ours, so we route the packet via the correct
1458                  * AppleTalk iface
1459                  */
1460                 return atalk_route_packet(skb, dev, ddp, len_hops, origlen);
1461         }
1462
1463         /*
1464          * Which socket - atalk_search_socket() looks for a *full match*
1465          * of the <net, node, port> tuple.
1466          */
1467         tosat.sat_addr.s_net  = ddp->deh_dnet;
1468         tosat.sat_addr.s_node = ddp->deh_dnode;
1469         tosat.sat_port        = ddp->deh_dport;
1470
1471         sock = atalk_search_socket(&tosat, atif);
1472         if (!sock) /* But not one of our sockets */
1473                 goto drop;
1474
1475         /* Queue packet (standard) */
1476         if (sock_queue_rcv_skb(sock, skb) < 0)
1477                 goto drop;
1478
1479         return NET_RX_SUCCESS;
1480
1481 drop:
1482         kfree_skb(skb);
1483 out:
1484         return NET_RX_DROP;
1485
1486 }
1487
1488 /*
1489  * Receive a LocalTalk frame. We make some demands on the caller here.
1490  * Caller must provide enough headroom on the packet to pull the short
1491  * header and append a long one.
1492  */
1493 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1494                      struct packet_type *pt, struct net_device *orig_dev)
1495 {
1496         if (!net_eq(dev_net(dev), &init_net))
1497                 goto freeit;
1498
1499         /* Expand any short form frames */
1500         if (skb_mac_header(skb)[2] == 1) {
1501                 struct ddpehdr *ddp;
1502                 /* Find our address */
1503                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1504
1505                 if (!ap || skb->len < sizeof(__be16) || skb->len > 1023)
1506                         goto freeit;
1507
1508                 /* Don't mangle buffer if shared */
1509                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1510                         return 0;
1511
1512                 /*
1513                  * The push leaves us with a ddephdr not an shdr, and
1514                  * handily the port bytes in the right place preset.
1515                  */
1516                 ddp = skb_push(skb, sizeof(*ddp) - 4);
1517
1518                 /* Now fill in the long header */
1519
1520                 /*
1521                  * These two first. The mac overlays the new source/dest
1522                  * network information so we MUST copy these before
1523                  * we write the network numbers !
1524                  */
1525
1526                 ddp->deh_dnode = skb_mac_header(skb)[0];     /* From physical header */
1527                 ddp->deh_snode = skb_mac_header(skb)[1];     /* From physical header */
1528
1529                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1530                 ddp->deh_snet  = ap->s_net;
1531                 ddp->deh_sum   = 0;             /* No checksum */
1532                 /*
1533                  * Not sure about this bit...
1534                  */
1535                 /* Non routable, so force a drop if we slip up later */
1536                 ddp->deh_len_hops = htons(skb->len + (DDP_MAXHOPS << 10));
1537         }
1538         skb_reset_transport_header(skb);
1539
1540         return atalk_rcv(skb, dev, pt, orig_dev);
1541 freeit:
1542         kfree_skb(skb);
1543         return 0;
1544 }
1545
1546 static int atalk_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
1547 {
1548         struct sock *sk = sock->sk;
1549         struct atalk_sock *at = at_sk(sk);
1550         DECLARE_SOCKADDR(struct sockaddr_at *, usat, msg->msg_name);
1551         int flags = msg->msg_flags;
1552         int loopback = 0;
1553         struct sockaddr_at local_satalk, gsat;
1554         struct sk_buff *skb;
1555         struct net_device *dev;
1556         struct ddpehdr *ddp;
1557         int size, hard_header_len;
1558         struct atalk_route *rt, *rt_lo = NULL;
1559         int err;
1560
1561         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1562                 return -EINVAL;
1563
1564         if (len > DDP_MAXSZ)
1565                 return -EMSGSIZE;
1566
1567         lock_sock(sk);
1568         if (usat) {
1569                 err = -EBUSY;
1570                 if (sock_flag(sk, SOCK_ZAPPED))
1571                         if (atalk_autobind(sk) < 0)
1572                                 goto out;
1573
1574                 err = -EINVAL;
1575                 if (msg->msg_namelen < sizeof(*usat) ||
1576                     usat->sat_family != AF_APPLETALK)
1577                         goto out;
1578
1579                 err = -EPERM;
1580                 /* netatalk didn't implement this check */
1581                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1582                     !sock_flag(sk, SOCK_BROADCAST)) {
1583                         goto out;
1584                 }
1585         } else {
1586                 err = -ENOTCONN;
1587                 if (sk->sk_state != TCP_ESTABLISHED)
1588                         goto out;
1589                 usat = &local_satalk;
1590                 usat->sat_family      = AF_APPLETALK;
1591                 usat->sat_port        = at->dest_port;
1592                 usat->sat_addr.s_node = at->dest_node;
1593                 usat->sat_addr.s_net  = at->dest_net;
1594         }
1595
1596         /* Build a packet */
1597         net_dbg_ratelimited("SK %p: Got address.\n", sk);
1598
1599         /* For headers */
1600         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1601
1602         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1603                 rt = atrtr_find(&usat->sat_addr);
1604         } else {
1605                 struct atalk_addr at_hint;
1606
1607                 at_hint.s_node = 0;
1608                 at_hint.s_net  = at->src_net;
1609
1610                 rt = atrtr_find(&at_hint);
1611         }
1612         err = -ENETUNREACH;
1613         if (!rt)
1614                 goto out;
1615
1616         dev = rt->dev;
1617
1618         net_dbg_ratelimited("SK %p: Size needed %d, device %s\n",
1619                         sk, size, dev->name);
1620
1621         hard_header_len = dev->hard_header_len;
1622         /* Leave room for loopback hardware header if necessary */
1623         if (usat->sat_addr.s_node == ATADDR_BCAST &&
1624             (dev->flags & IFF_LOOPBACK || !(rt->flags & RTF_GATEWAY))) {
1625                 struct atalk_addr at_lo;
1626
1627                 at_lo.s_node = 0;
1628                 at_lo.s_net  = 0;
1629
1630                 rt_lo = atrtr_find(&at_lo);
1631
1632                 if (rt_lo && rt_lo->dev->hard_header_len > hard_header_len)
1633                         hard_header_len = rt_lo->dev->hard_header_len;
1634         }
1635
1636         size += hard_header_len;
1637         release_sock(sk);
1638         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1639         lock_sock(sk);
1640         if (!skb)
1641                 goto out;
1642
1643         skb_reserve(skb, ddp_dl->header_length);
1644         skb_reserve(skb, hard_header_len);
1645         skb->dev = dev;
1646
1647         net_dbg_ratelimited("SK %p: Begin build.\n", sk);
1648
1649         ddp = skb_put(skb, sizeof(struct ddpehdr));
1650         ddp->deh_len_hops  = htons(len + sizeof(*ddp));
1651         ddp->deh_dnet  = usat->sat_addr.s_net;
1652         ddp->deh_snet  = at->src_net;
1653         ddp->deh_dnode = usat->sat_addr.s_node;
1654         ddp->deh_snode = at->src_node;
1655         ddp->deh_dport = usat->sat_port;
1656         ddp->deh_sport = at->src_port;
1657
1658         net_dbg_ratelimited("SK %p: Copy user data (%zd bytes).\n", sk, len);
1659
1660         err = memcpy_from_msg(skb_put(skb, len), msg, len);
1661         if (err) {
1662                 kfree_skb(skb);
1663                 err = -EFAULT;
1664                 goto out;
1665         }
1666
1667         if (sk->sk_no_check_tx)
1668                 ddp->deh_sum = 0;
1669         else
1670                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1671
1672         /*
1673          * Loopback broadcast packets to non gateway targets (ie routes
1674          * to group we are in)
1675          */
1676         if (ddp->deh_dnode == ATADDR_BCAST &&
1677             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1678                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1679
1680                 if (skb2) {
1681                         loopback = 1;
1682                         net_dbg_ratelimited("SK %p: send out(copy).\n", sk);
1683                         /*
1684                          * If it fails it is queued/sent above in the aarp queue
1685                          */
1686                         aarp_send_ddp(dev, skb2, &usat->sat_addr, NULL);
1687                 }
1688         }
1689
1690         if (dev->flags & IFF_LOOPBACK || loopback) {
1691                 net_dbg_ratelimited("SK %p: Loop back.\n", sk);
1692                 /* loop back */
1693                 skb_orphan(skb);
1694                 if (ddp->deh_dnode == ATADDR_BCAST) {
1695                         if (!rt_lo) {
1696                                 kfree_skb(skb);
1697                                 err = -ENETUNREACH;
1698                                 goto out;
1699                         }
1700                         dev = rt_lo->dev;
1701                         skb->dev = dev;
1702                 }
1703                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1704         } else {
1705                 net_dbg_ratelimited("SK %p: send out.\n", sk);
1706                 if (rt->flags & RTF_GATEWAY) {
1707                     gsat.sat_addr = rt->gateway;
1708                     usat = &gsat;
1709                 }
1710
1711                 /*
1712                  * If it fails it is queued/sent above in the aarp queue
1713                  */
1714                 aarp_send_ddp(dev, skb, &usat->sat_addr, NULL);
1715         }
1716         net_dbg_ratelimited("SK %p: Done write (%zd).\n", sk, len);
1717
1718 out:
1719         release_sock(sk);
1720         return err ? : len;
1721 }
1722
1723 static int atalk_recvmsg(struct socket *sock, struct msghdr *msg, size_t size,
1724                          int flags)
1725 {
1726         struct sock *sk = sock->sk;
1727         struct ddpehdr *ddp;
1728         int copied = 0;
1729         int offset = 0;
1730         int err = 0;
1731         struct sk_buff *skb;
1732
1733         skb = skb_recv_datagram(sk, flags, &err);
1734         lock_sock(sk);
1735
1736         if (!skb)
1737                 goto out;
1738
1739         /* FIXME: use skb->cb to be able to use shared skbs */
1740         ddp = ddp_hdr(skb);
1741         copied = ntohs(ddp->deh_len_hops) & 1023;
1742
1743         if (sk->sk_type != SOCK_RAW) {
1744                 offset = sizeof(*ddp);
1745                 copied -= offset;
1746         }
1747
1748         if (copied > size) {
1749                 copied = size;
1750                 msg->msg_flags |= MSG_TRUNC;
1751         }
1752         err = skb_copy_datagram_msg(skb, offset, msg, copied);
1753
1754         if (!err && msg->msg_name) {
1755                 DECLARE_SOCKADDR(struct sockaddr_at *, sat, msg->msg_name);
1756                 sat->sat_family      = AF_APPLETALK;
1757                 sat->sat_port        = ddp->deh_sport;
1758                 sat->sat_addr.s_node = ddp->deh_snode;
1759                 sat->sat_addr.s_net  = ddp->deh_snet;
1760                 msg->msg_namelen     = sizeof(*sat);
1761         }
1762
1763         skb_free_datagram(sk, skb);     /* Free the datagram. */
1764
1765 out:
1766         release_sock(sk);
1767         return err ? : copied;
1768 }
1769
1770
1771 /*
1772  * AppleTalk ioctl calls.
1773  */
1774 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1775 {
1776         int rc = -ENOIOCTLCMD;
1777         struct sock *sk = sock->sk;
1778         void __user *argp = (void __user *)arg;
1779
1780         switch (cmd) {
1781         /* Protocol layer */
1782         case TIOCOUTQ: {
1783                 long amount = sk->sk_sndbuf - sk_wmem_alloc_get(sk);
1784
1785                 if (amount < 0)
1786                         amount = 0;
1787                 rc = put_user(amount, (int __user *)argp);
1788                 break;
1789         }
1790         case TIOCINQ: {
1791                 struct sk_buff *skb;
1792                 long amount = 0;
1793
1794                 spin_lock_irq(&sk->sk_receive_queue.lock);
1795                 skb = skb_peek(&sk->sk_receive_queue);
1796                 if (skb)
1797                         amount = skb->len - sizeof(struct ddpehdr);
1798                 spin_unlock_irq(&sk->sk_receive_queue.lock);
1799                 rc = put_user(amount, (int __user *)argp);
1800                 break;
1801         }
1802         /* Routing */
1803         case SIOCADDRT:
1804         case SIOCDELRT:
1805                 rc = -EPERM;
1806                 if (capable(CAP_NET_ADMIN))
1807                         rc = atrtr_ioctl(cmd, argp);
1808                 break;
1809         /* Interface */
1810         case SIOCGIFADDR:
1811         case SIOCSIFADDR:
1812         case SIOCGIFBRDADDR:
1813         case SIOCATALKDIFADDR:
1814         case SIOCDIFADDR:
1815         case SIOCSARP:          /* proxy AARP */
1816         case SIOCDARP:          /* proxy AARP */
1817                 rtnl_lock();
1818                 rc = atif_ioctl(cmd, argp);
1819                 rtnl_unlock();
1820                 break;
1821         }
1822
1823         return rc;
1824 }
1825
1826
1827 #ifdef CONFIG_COMPAT
1828 static int atalk_compat_routing_ioctl(struct sock *sk, unsigned int cmd,
1829                 struct compat_rtentry __user *ur)
1830 {
1831         compat_uptr_t rtdev;
1832         struct rtentry rt;
1833
1834         if (copy_from_user(&rt.rt_dst, &ur->rt_dst,
1835                         3 * sizeof(struct sockaddr)) ||
1836             get_user(rt.rt_flags, &ur->rt_flags) ||
1837             get_user(rt.rt_metric, &ur->rt_metric) ||
1838             get_user(rt.rt_mtu, &ur->rt_mtu) ||
1839             get_user(rt.rt_window, &ur->rt_window) ||
1840             get_user(rt.rt_irtt, &ur->rt_irtt) ||
1841             get_user(rtdev, &ur->rt_dev))
1842                 return -EFAULT;
1843
1844         switch (cmd) {
1845         case SIOCDELRT:
1846                 if (rt.rt_dst.sa_family != AF_APPLETALK)
1847                         return -EINVAL;
1848                 return atrtr_delete(&((struct sockaddr_at *)
1849                                       &rt.rt_dst)->sat_addr);
1850
1851         case SIOCADDRT:
1852                 rt.rt_dev = compat_ptr(rtdev);
1853                 return atrtr_ioctl_addrt(&rt);
1854         default:
1855                 return -EINVAL;
1856         }
1857 }
1858 static int atalk_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1859 {
1860         void __user *argp = compat_ptr(arg);
1861         struct sock *sk = sock->sk;
1862
1863         switch (cmd) {
1864         case SIOCADDRT:
1865         case SIOCDELRT:
1866                 return atalk_compat_routing_ioctl(sk, cmd, argp);
1867         /*
1868          * SIOCATALKDIFADDR is a SIOCPROTOPRIVATE ioctl number, so we
1869          * cannot handle it in common code. The data we access if ifreq
1870          * here is compatible, so we can simply call the native
1871          * handler.
1872          */
1873         case SIOCATALKDIFADDR:
1874                 return atalk_ioctl(sock, cmd, (unsigned long)argp);
1875         default:
1876                 return -ENOIOCTLCMD;
1877         }
1878 }
1879 #endif /* CONFIG_COMPAT */
1880
1881
1882 static const struct net_proto_family atalk_family_ops = {
1883         .family         = PF_APPLETALK,
1884         .create         = atalk_create,
1885         .owner          = THIS_MODULE,
1886 };
1887
1888 static const struct proto_ops atalk_dgram_ops = {
1889         .family         = PF_APPLETALK,
1890         .owner          = THIS_MODULE,
1891         .release        = atalk_release,
1892         .bind           = atalk_bind,
1893         .connect        = atalk_connect,
1894         .socketpair     = sock_no_socketpair,
1895         .accept         = sock_no_accept,
1896         .getname        = atalk_getname,
1897         .poll           = datagram_poll,
1898         .ioctl          = atalk_ioctl,
1899         .gettstamp      = sock_gettstamp,
1900 #ifdef CONFIG_COMPAT
1901         .compat_ioctl   = atalk_compat_ioctl,
1902 #endif
1903         .listen         = sock_no_listen,
1904         .shutdown       = sock_no_shutdown,
1905         .sendmsg        = atalk_sendmsg,
1906         .recvmsg        = atalk_recvmsg,
1907         .mmap           = sock_no_mmap,
1908 };
1909
1910 static struct notifier_block ddp_notifier = {
1911         .notifier_call  = ddp_device_event,
1912 };
1913
1914 static struct packet_type ltalk_packet_type __read_mostly = {
1915         .type           = cpu_to_be16(ETH_P_LOCALTALK),
1916         .func           = ltalk_rcv,
1917 };
1918
1919 static struct packet_type ppptalk_packet_type __read_mostly = {
1920         .type           = cpu_to_be16(ETH_P_PPPTALK),
1921         .func           = atalk_rcv,
1922 };
1923
1924 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1925
1926 /* Export symbols for use by drivers when AppleTalk is a module */
1927 EXPORT_SYMBOL(atrtr_get_dev);
1928 EXPORT_SYMBOL(atalk_find_dev_addr);
1929
1930 /* Called by proto.c on kernel start up */
1931 static int __init atalk_init(void)
1932 {
1933         int rc;
1934
1935         rc = proto_register(&ddp_proto, 0);
1936         if (rc)
1937                 goto out;
1938
1939         rc = sock_register(&atalk_family_ops);
1940         if (rc)
1941                 goto out_proto;
1942
1943         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1944         if (!ddp_dl) {
1945                 pr_crit("Unable to register DDP with SNAP.\n");
1946                 rc = -ENOMEM;
1947                 goto out_sock;
1948         }
1949
1950         dev_add_pack(&ltalk_packet_type);
1951         dev_add_pack(&ppptalk_packet_type);
1952
1953         rc = register_netdevice_notifier(&ddp_notifier);
1954         if (rc)
1955                 goto out_snap;
1956
1957         rc = aarp_proto_init();
1958         if (rc)
1959                 goto out_dev;
1960
1961         rc = atalk_proc_init();
1962         if (rc)
1963                 goto out_aarp;
1964
1965         rc = atalk_register_sysctl();
1966         if (rc)
1967                 goto out_proc;
1968 out:
1969         return rc;
1970 out_proc:
1971         atalk_proc_exit();
1972 out_aarp:
1973         aarp_cleanup_module();
1974 out_dev:
1975         unregister_netdevice_notifier(&ddp_notifier);
1976 out_snap:
1977         dev_remove_pack(&ppptalk_packet_type);
1978         dev_remove_pack(&ltalk_packet_type);
1979         unregister_snap_client(ddp_dl);
1980 out_sock:
1981         sock_unregister(PF_APPLETALK);
1982 out_proto:
1983         proto_unregister(&ddp_proto);
1984         goto out;
1985 }
1986 module_init(atalk_init);
1987
1988 /*
1989  * No explicit module reference count manipulation is needed in the
1990  * protocol. Socket layer sets module reference count for us
1991  * and interfaces reference counting is done
1992  * by the network device layer.
1993  *
1994  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1995  * sockets should be closed from user space.
1996  */
1997 static void __exit atalk_exit(void)
1998 {
1999 #ifdef CONFIG_SYSCTL
2000         atalk_unregister_sysctl();
2001 #endif /* CONFIG_SYSCTL */
2002         atalk_proc_exit();
2003         aarp_cleanup_module();  /* General aarp clean-up. */
2004         unregister_netdevice_notifier(&ddp_notifier);
2005         dev_remove_pack(&ltalk_packet_type);
2006         dev_remove_pack(&ppptalk_packet_type);
2007         unregister_snap_client(ddp_dl);
2008         sock_unregister(PF_APPLETALK);
2009         proto_unregister(&ddp_proto);
2010 }
2011 module_exit(atalk_exit);
2012
2013 MODULE_LICENSE("GPL");
2014 MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>");
2015 MODULE_DESCRIPTION("AppleTalk 0.20\n");
2016 MODULE_ALIAS_NETPROTO(PF_APPLETALK);