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