git.oblomov.eu Git - linux-2.6/blob - net/appletalk/ddp.c

   1 /*
   2  *      DDP:    An implementation of the AppleTalk DDP protocol for
   3  *              Ethernet 'ELAP'.
   4  *
   5  *              Alan Cox  <Alan.Cox@linux.org>
   6  *
   7  *              With more than a little assistance from
   8  *
   9  *              Wesley Craig <netatalk@umich.edu>
  10  *
  11  *      Fixes:
  12  *              Neil Horman             :       Added missing device ioctls
  13  *              Michael Callahan        :       Made routing work
  14  *              Wesley Craig            :       Fix probing to listen to a
  15  *                                              passed node id.
  16  *              Alan Cox                :       Added send/recvmsg support
  17  *              Alan Cox                :       Moved at. to protinfo in
  18  *                                              socket.
  19  *              Alan Cox                :       Added firewall hooks.
  20  *              Alan Cox                :       Supports new ARPHRD_LOOPBACK
  21  *              Christer Weinigel       :       Routing and /proc fixes.
  22  *              Bradford Johnson        :       LocalTalk.
  23  *              Tom Dyas                :       Module support.
  24  *              Alan Cox                :       Hooks for PPP (based on the
  25  *                                              LocalTalk hook).
  26  *              Alan Cox                :       Posix bits
  27  *              Alan Cox/Mike Freeman   :       Possible fix to NBP problems
  28  *              Bradford Johnson        :       IP-over-DDP (experimental)
  29  *              Jay Schulist            :       Moved IP-over-DDP to its own
  30  *                                              driver file. (ipddp.c & ipddp.h)
  31  *              Jay Schulist            :       Made work as module with
  32  *                                              AppleTalk drivers, cleaned it.
  33  *              Rob Newberry            :       Added proxy AARP and AARP
  34  *                                              procfs, moved probing to AARP
  35  *                                              module.
  36  *              Adrian Sun/
  37  *              Michael Zuelsdorff      :       fix for net.0 packets. don't
  38  *                                              allow illegal ether/tokentalk
  39  *                                              port assignment. we lose a
  40  *                                              valid localtalk port as a
  41  *                                              result.
  42  *              Arnaldo C. de Melo      :       Cleanup, in preparation for
  43  *                                              shared skb support 8)
  44  *              Arnaldo C. de Melo      :       Move proc stuff to atalk_proc.c,
  45  *                                              use seq_file
  46  *
  47  *              This program is free software; you can redistribute it and/or
  48  *              modify it under the terms of the GNU General Public License
  49  *              as published by the Free Software Foundation; either version
  50  *              2 of the License, or (at your option) any later version.
  51  *
  52  */
  53
  54 #include <linux/config.h>
  55 #include <linux/module.h>
  56 #include <linux/if_arp.h>
  57 #include <linux/termios.h>      /* For TIOCOUTQ/INQ */
  58 #include <net/datalink.h>
  59 #include <net/psnap.h>
  60 #include <net/sock.h>
  61 #include <net/tcp_states.h>
  62 #include <net/route.h>
  63 #include <linux/atalk.h>
  64
  65 struct datalink_proto *ddp_dl, *aarp_dl;
  66 static struct proto_ops atalk_dgram_ops;
  67
  68 /**************************************************************************\
  69 *                                                                          *
  70 * Handlers for the socket list.                                            *
  71 *                                                                          *
  72 \**************************************************************************/
  73
  74 HLIST_HEAD(atalk_sockets);
  75 DEFINE_RWLOCK(atalk_sockets_lock);
  76
  77 static inline void __atalk_insert_socket(struct sock *sk)
  78 {
  79         sk_add_node(sk, &atalk_sockets);
  80 }
  81
  82 static inline void atalk_remove_socket(struct sock *sk)
  83 {
  84         write_lock_bh(&atalk_sockets_lock);
  85         sk_del_node_init(sk);
  86         write_unlock_bh(&atalk_sockets_lock);
  87 }
  88
  89 static struct sock *atalk_search_socket(struct sockaddr_at *to,
  90                                         struct atalk_iface *atif)
  91 {
  92         struct sock *s;
  93         struct hlist_node *node;
  94
  95         read_lock_bh(&atalk_sockets_lock);
  96         sk_for_each(s, node, &atalk_sockets) {
  97                 struct atalk_sock *at = at_sk(s);
  98
  99                 if (to->sat_port != at->src_port)
 100                         continue;
 101
 102                 if (to->sat_addr.s_net == ATADDR_ANYNET &&
 103                     to->sat_addr.s_node == ATADDR_BCAST &&
 104                     at->src_net == atif->address.s_net)
 105                         goto found;
 106
 107                 if (to->sat_addr.s_net == at->src_net &&
 108                     (to->sat_addr.s_node == at->src_node ||
 109                      to->sat_addr.s_node == ATADDR_BCAST ||
 110                      to->sat_addr.s_node == ATADDR_ANYNODE))
 111                         goto found;
 112
 113                 /* XXXX.0 -- we got a request for this router. make sure
 114                  * that the node is appropriately set. */
 115                 if (to->sat_addr.s_node == ATADDR_ANYNODE &&
 116                     to->sat_addr.s_net != ATADDR_ANYNET &&
 117                     atif->address.s_node == at->src_node) {
 118                         to->sat_addr.s_node = atif->address.s_node;
 119                         goto found;
 120                 }
 121         }
 122         s = NULL;
 123 found:
 124         read_unlock_bh(&atalk_sockets_lock);
 125         return s;
 126 }
 127
 128 /**
 129  * atalk_find_or_insert_socket - Try to find a socket matching ADDR
 130  * @sk - socket to insert in the list if it is not there already
 131  * @sat - address to search for
 132  *
 133  * Try to find a socket matching ADDR in the socket list, if found then return
 134  * it. If not, insert SK into the socket list.
 135  *
 136  * This entire operation must execute atomically.
 137  */
 138 static struct sock *atalk_find_or_insert_socket(struct sock *sk,
 139                                                 struct sockaddr_at *sat)
 140 {
 141         struct sock *s;
 142         struct hlist_node *node;
 143         struct atalk_sock *at;
 144
 145         write_lock_bh(&atalk_sockets_lock);
 146         sk_for_each(s, node, &atalk_sockets) {
 147                 at = at_sk(s);
 148
 149                 if (at->src_net == sat->sat_addr.s_net &&
 150                     at->src_node == sat->sat_addr.s_node &&
 151                     at->src_port == sat->sat_port)
 152                         goto found;
 153         }
 154         s = NULL;
 155         __atalk_insert_socket(sk); /* Wheee, it's free, assign and insert. */
 156 found:
 157         write_unlock_bh(&atalk_sockets_lock);
 158         return s;
 159 }
 160
 161 static void atalk_destroy_timer(unsigned long data)
 162 {
 163         struct sock *sk = (struct sock *)data;
 164
 165         if (atomic_read(&sk->sk_wmem_alloc) ||
 166             atomic_read(&sk->sk_rmem_alloc)) {
 167                 sk->sk_timer.expires = jiffies + SOCK_DESTROY_TIME;
 168                 add_timer(&sk->sk_timer);
 169         } else
 170                 sock_put(sk);
 171 }
 172
 173 static inline void atalk_destroy_socket(struct sock *sk)
 174 {
 175         atalk_remove_socket(sk);
 176         skb_queue_purge(&sk->sk_receive_queue);
 177
 178         if (atomic_read(&sk->sk_wmem_alloc) ||
 179             atomic_read(&sk->sk_rmem_alloc)) {
 180                 init_timer(&sk->sk_timer);
 181                 sk->sk_timer.expires    = jiffies + SOCK_DESTROY_TIME;
 182                 sk->sk_timer.function   = atalk_destroy_timer;
 183                 sk->sk_timer.data       = (unsigned long)sk;
 184                 add_timer(&sk->sk_timer);
 185         } else
 186                 sock_put(sk);
 187 }
 188
 189 /**************************************************************************\
 190 *                                                                          *
 191 * Routing tables for the AppleTalk socket layer.                           *
 192 *                                                                          *
 193 \**************************************************************************/
 194
 195 /* Anti-deadlock ordering is atalk_routes_lock --> iface_lock -DaveM */
 196 struct atalk_route *atalk_routes;
 197 DEFINE_RWLOCK(atalk_routes_lock);
 198
 199 struct atalk_iface *atalk_interfaces;
 200 DEFINE_RWLOCK(atalk_interfaces_lock);
 201
 202 /* For probing devices or in a routerless network */
 203 struct atalk_route atrtr_default;
 204
 205 /* AppleTalk interface control */
 206 /*
 207  * Drop a device. Doesn't drop any of its routes - that is the caller's
 208  * problem. Called when we down the interface or delete the address.
 209  */
 210 static void atif_drop_device(struct net_device *dev)
 211 {
 212         struct atalk_iface **iface = &atalk_interfaces;
 213         struct atalk_iface *tmp;
 214
 215         write_lock_bh(&atalk_interfaces_lock);
 216         while ((tmp = *iface) != NULL) {
 217                 if (tmp->dev == dev) {
 218                         *iface = tmp->next;
 219                         dev_put(dev);
 220                         kfree(tmp);
 221                         dev->atalk_ptr = NULL;
 222                 } else
 223                         iface = &tmp->next;
 224         }
 225         write_unlock_bh(&atalk_interfaces_lock);
 226 }
 227
 228 static struct atalk_iface *atif_add_device(struct net_device *dev,
 229                                            struct atalk_addr *sa)
 230 {
 231         struct atalk_iface *iface = kmalloc(sizeof(*iface), GFP_KERNEL);
 232
 233         if (!iface)
 234                 goto out;
 235
 236         memset(iface, 0, sizeof(*iface));
 237         dev_hold(dev);
 238         iface->dev = dev;
 239         dev->atalk_ptr = iface;
 240         iface->address = *sa;
 241         iface->status = 0;
 242
 243         write_lock_bh(&atalk_interfaces_lock);
 244         iface->next = atalk_interfaces;
 245         atalk_interfaces = iface;
 246         write_unlock_bh(&atalk_interfaces_lock);
 247 out:
 248         return iface;
 249 }
 250
 251 /* Perform phase 2 AARP probing on our tentative address */
 252 static int atif_probe_device(struct atalk_iface *atif)
 253 {
 254         int netrange = ntohs(atif->nets.nr_lastnet) -
 255                         ntohs(atif->nets.nr_firstnet) + 1;
 256         int probe_net = ntohs(atif->address.s_net);
 257         int probe_node = atif->address.s_node;
 258         int netct, nodect;
 259
 260         /* Offset the network we start probing with */
 261         if (probe_net == ATADDR_ANYNET) {
 262                 probe_net = ntohs(atif->nets.nr_firstnet);
 263                 if (netrange)
 264                         probe_net += jiffies % netrange;
 265         }
 266         if (probe_node == ATADDR_ANYNODE)
 267                 probe_node = jiffies & 0xFF;
 268
 269         /* Scan the networks */
 270         atif->status |= ATIF_PROBE;
 271         for (netct = 0; netct <= netrange; netct++) {
 272                 /* Sweep the available nodes from a given start */
 273                 atif->address.s_net = htons(probe_net);
 274                 for (nodect = 0; nodect < 256; nodect++) {
 275                         atif->address.s_node = (nodect + probe_node) & 0xFF;
 276                         if (atif->address.s_node > 0 &&
 277                             atif->address.s_node < 254) {
 278                                 /* Probe a proposed address */
 279                                 aarp_probe_network(atif);
 280
 281                                 if (!(atif->status & ATIF_PROBE_FAIL)) {
 282                                         atif->status &= ~ATIF_PROBE;
 283                                         return 0;
 284                                 }
 285                         }
 286                         atif->status &= ~ATIF_PROBE_FAIL;
 287                 }
 288                 probe_net++;
 289                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 290                         probe_net = ntohs(atif->nets.nr_firstnet);
 291         }
 292         atif->status &= ~ATIF_PROBE;
 293
 294         return -EADDRINUSE;     /* Network is full... */
 295 }
 296
 297
 298 /* Perform AARP probing for a proxy address */
 299 static int atif_proxy_probe_device(struct atalk_iface *atif,
 300                                    struct atalk_addr* proxy_addr)
 301 {
 302         int netrange = ntohs(atif->nets.nr_lastnet) -
 303                         ntohs(atif->nets.nr_firstnet) + 1;
 304         /* we probe the interface's network */
 305         int probe_net = ntohs(atif->address.s_net);
 306         int probe_node = ATADDR_ANYNODE;            /* we'll take anything */
 307         int netct, nodect;
 308
 309         /* Offset the network we start probing with */
 310         if (probe_net == ATADDR_ANYNET) {
 311                 probe_net = ntohs(atif->nets.nr_firstnet);
 312                 if (netrange)
 313                         probe_net += jiffies % netrange;
 314         }
 315
 316         if (probe_node == ATADDR_ANYNODE)
 317                 probe_node = jiffies & 0xFF;
 318
 319         /* Scan the networks */
 320         for (netct = 0; netct <= netrange; netct++) {
 321                 /* Sweep the available nodes from a given start */
 322                 proxy_addr->s_net = htons(probe_net);
 323                 for (nodect = 0; nodect < 256; nodect++) {
 324                         proxy_addr->s_node = (nodect + probe_node) & 0xFF;
 325                         if (proxy_addr->s_node > 0 &&
 326                             proxy_addr->s_node < 254) {
 327                                 /* Tell AARP to probe a proposed address */
 328                                 int ret = aarp_proxy_probe_network(atif,
 329                                                                     proxy_addr);
 330
 331                                 if (ret != -EADDRINUSE)
 332                                         return ret;
 333                         }
 334                 }
 335                 probe_net++;
 336                 if (probe_net > ntohs(atif->nets.nr_lastnet))
 337                         probe_net = ntohs(atif->nets.nr_firstnet);
 338         }
 339
 340         return -EADDRINUSE;     /* Network is full... */
 341 }
 342
 343
 344 struct atalk_addr *atalk_find_dev_addr(struct net_device *dev)
 345 {
 346         struct atalk_iface *iface = dev->atalk_ptr;
 347         return iface ? &iface->address : NULL;
 348 }
 349
 350 static struct atalk_addr *atalk_find_primary(void)
 351 {
 352         struct atalk_iface *fiface = NULL;
 353         struct atalk_addr *retval;
 354         struct atalk_iface *iface;
 355
 356         /*
 357          * Return a point-to-point interface only if
 358          * there is no non-ptp interface available.
 359          */
 360         read_lock_bh(&atalk_interfaces_lock);
 361         for (iface = atalk_interfaces; iface; iface = iface->next) {
 362                 if (!fiface && !(iface->dev->flags & IFF_LOOPBACK))
 363                         fiface = iface;
 364                 if (!(iface->dev->flags & (IFF_LOOPBACK | IFF_POINTOPOINT))) {
 365                         retval = &iface->address;
 366                         goto out;
 367                 }
 368         }
 369
 370         if (fiface)
 371                 retval = &fiface->address;
 372         else if (atalk_interfaces)
 373                 retval = &atalk_interfaces->address;
 374         else
 375                 retval = NULL;
 376 out:
 377         read_unlock_bh(&atalk_interfaces_lock);
 378         return retval;
 379 }
 380
 381 /*
 382  * Find a match for 'any network' - ie any of our interfaces with that
 383  * node number will do just nicely.
 384  */
 385 static struct atalk_iface *atalk_find_anynet(int node, struct net_device *dev)
 386 {
 387         struct atalk_iface *iface = dev->atalk_ptr;
 388
 389         if (!iface || iface->status & ATIF_PROBE)
 390                 goto out_err;
 391
 392         if (node != ATADDR_BCAST &&
 393             iface->address.s_node != node &&
 394             node != ATADDR_ANYNODE)
 395                 goto out_err;
 396 out:
 397         return iface;
 398 out_err:
 399         iface = NULL;
 400         goto out;
 401 }
 402
 403 /* Find a match for a specific network:node pair */
 404 static struct atalk_iface *atalk_find_interface(__be16 net, int node)
 405 {
 406         struct atalk_iface *iface;
 407
 408         read_lock_bh(&atalk_interfaces_lock);
 409         for (iface = atalk_interfaces; iface; iface = iface->next) {
 410                 if ((node == ATADDR_BCAST ||
 411                      node == ATADDR_ANYNODE ||
 412                      iface->address.s_node == node) &&
 413                     iface->address.s_net == net &&
 414                     !(iface->status & ATIF_PROBE))
 415                         break;
 416
 417                 /* XXXX.0 -- net.0 returns the iface associated with net */
 418                 if (node == ATADDR_ANYNODE && net != ATADDR_ANYNET &&
 419                     ntohs(iface->nets.nr_firstnet) <= ntohs(net) &&
 420                     ntohs(net) <= ntohs(iface->nets.nr_lastnet))
 421                         break;
 422         }
 423         read_unlock_bh(&atalk_interfaces_lock);
 424         return iface;
 425 }
 426
 427
 428 /*
 429  * Find a route for an AppleTalk packet. This ought to get cached in
 430  * the socket (later on...). We know about host routes and the fact
 431  * that a route must be direct to broadcast.
 432  */
 433 static struct atalk_route *atrtr_find(struct atalk_addr *target)
 434 {
 435         /*
 436          * we must search through all routes unless we find a
 437          * host route, because some host routes might overlap
 438          * network routes
 439          */
 440         struct atalk_route *net_route = NULL;
 441         struct atalk_route *r;
 442
 443         read_lock_bh(&atalk_routes_lock);
 444         for (r = atalk_routes; r; r = r->next) {
 445                 if (!(r->flags & RTF_UP))
 446                         continue;
 447
 448                 if (r->target.s_net == target->s_net) {
 449                         if (r->flags & RTF_HOST) {
 450                                 /*
 451                                  * if this host route is for the target,
 452                                  * the we're done
 453                                  */
 454                                 if (r->target.s_node == target->s_node)
 455                                         goto out;
 456                         } else
 457                                 /*
 458                                  * this route will work if there isn't a
 459                                  * direct host route, so cache it
 460                                  */
 461                                 net_route = r;
 462                 }
 463         }
 464
 465         /*
 466          * if we found a network route but not a direct host
 467          * route, then return it
 468          */
 469         if (net_route)
 470                 r = net_route;
 471         else if (atrtr_default.dev)
 472                 r = &atrtr_default;
 473         else /* No route can be found */
 474                 r = NULL;
 475 out:
 476         read_unlock_bh(&atalk_routes_lock);
 477         return r;
 478 }
 479
 480
 481 /*
 482  * Given an AppleTalk network, find the device to use. This can be
 483  * a simple lookup.
 484  */
 485 struct net_device *atrtr_get_dev(struct atalk_addr *sa)
 486 {
 487         struct atalk_route *atr = atrtr_find(sa);
 488         return atr ? atr->dev : NULL;
 489 }
 490
 491 /* Set up a default router */
 492 static void atrtr_set_default(struct net_device *dev)
 493 {
 494         atrtr_default.dev            = dev;
 495         atrtr_default.flags          = RTF_UP;
 496         atrtr_default.gateway.s_net  = htons(0);
 497         atrtr_default.gateway.s_node = 0;
 498 }
 499
 500 /*
 501  * Add a router. Basically make sure it looks valid and stuff the
 502  * entry in the list. While it uses netranges we always set them to one
 503  * entry to work like netatalk.
 504  */
 505 static int atrtr_create(struct rtentry *r, struct net_device *devhint)
 506 {
 507         struct sockaddr_at *ta = (struct sockaddr_at *)&r->rt_dst;
 508         struct sockaddr_at *ga = (struct sockaddr_at *)&r->rt_gateway;
 509         struct atalk_route *rt;
 510         struct atalk_iface *iface, *riface;
 511         int retval = -EINVAL;
 512
 513         /*
 514          * Fixme: Raise/Lower a routing change semaphore for these
 515          * operations.
 516          */
 517
 518         /* Validate the request */
 519         if (ta->sat_family != AF_APPLETALK ||
 520             (!devhint && ga->sat_family != AF_APPLETALK))
 521                 goto out;
 522
 523         /* Now walk the routing table and make our decisions */
 524         write_lock_bh(&atalk_routes_lock);
 525         for (rt = atalk_routes; rt; rt = rt->next) {
 526                 if (r->rt_flags != rt->flags)
 527                         continue;
 528
 529                 if (ta->sat_addr.s_net == rt->target.s_net) {
 530                         if (!(rt->flags & RTF_HOST))
 531                                 break;
 532                         if (ta->sat_addr.s_node == rt->target.s_node)
 533                                 break;
 534                 }
 535         }
 536
 537         if (!devhint) {
 538                 riface = NULL;
 539
 540                 read_lock_bh(&atalk_interfaces_lock);
 541                 for (iface = atalk_interfaces; iface; iface = iface->next) {
 542                         if (!riface &&
 543                             ntohs(ga->sat_addr.s_net) >=
 544                                         ntohs(iface->nets.nr_firstnet) &&
 545                             ntohs(ga->sat_addr.s_net) <=
 546                                         ntohs(iface->nets.nr_lastnet))
 547                                 riface = iface;
 548
 549                         if (ga->sat_addr.s_net == iface->address.s_net &&
 550                             ga->sat_addr.s_node == iface->address.s_node)
 551                                 riface = iface;
 552                 }
 553                 read_unlock_bh(&atalk_interfaces_lock);
 554
 555                 retval = -ENETUNREACH;
 556                 if (!riface)
 557                         goto out_unlock;
 558
 559                 devhint = riface->dev;
 560         }
 561
 562         if (!rt) {
 563                 rt = kmalloc(sizeof(*rt), GFP_ATOMIC);
 564
 565                 retval = -ENOBUFS;
 566                 if (!rt)
 567                         goto out_unlock;
 568                 memset(rt, 0, sizeof(*rt));
 569
 570                 rt->next = atalk_routes;
 571                 atalk_routes = rt;
 572         }
 573
 574         /* Fill in the routing entry */
 575         rt->target  = ta->sat_addr;
 576         dev_hold(devhint);
 577         rt->dev     = devhint;
 578         rt->flags   = r->rt_flags;
 579         rt->gateway = ga->sat_addr;
 580
 581         retval = 0;
 582 out_unlock:
 583         write_unlock_bh(&atalk_routes_lock);
 584 out:
 585         return retval;
 586 }
 587
 588 /* Delete a route. Find it and discard it */
 589 static int atrtr_delete(struct atalk_addr * addr)
 590 {
 591         struct atalk_route **r = &atalk_routes;
 592         int retval = 0;
 593         struct atalk_route *tmp;
 594
 595         write_lock_bh(&atalk_routes_lock);
 596         while ((tmp = *r) != NULL) {
 597                 if (tmp->target.s_net == addr->s_net &&
 598                     (!(tmp->flags&RTF_GATEWAY) ||
 599                      tmp->target.s_node == addr->s_node)) {
 600                         *r = tmp->next;
 601                         dev_put(tmp->dev);
 602                         kfree(tmp);
 603                         goto out;
 604                 }
 605                 r = &tmp->next;
 606         }
 607         retval = -ENOENT;
 608 out:
 609         write_unlock_bh(&atalk_routes_lock);
 610         return retval;
 611 }
 612
 613 /*
 614  * Called when a device is downed. Just throw away any routes
 615  * via it.
 616  */
 617 static void atrtr_device_down(struct net_device *dev)
 618 {
 619         struct atalk_route **r = &atalk_routes;
 620         struct atalk_route *tmp;
 621
 622         write_lock_bh(&atalk_routes_lock);
 623         while ((tmp = *r) != NULL) {
 624                 if (tmp->dev == dev) {
 625                         *r = tmp->next;
 626                         dev_put(dev);
 627                         kfree(tmp);
 628                 } else
 629                         r = &tmp->next;
 630         }
 631         write_unlock_bh(&atalk_routes_lock);
 632
 633         if (atrtr_default.dev == dev)
 634                 atrtr_set_default(NULL);
 635 }
 636
 637 /* Actually down the interface */
 638 static inline void atalk_dev_down(struct net_device *dev)
 639 {
 640         atrtr_device_down(dev); /* Remove all routes for the device */
 641         aarp_device_down(dev);  /* Remove AARP entries for the device */
 642         atif_drop_device(dev);  /* Remove the device */
 643 }
 644
 645 /*
 646  * A device event has occurred. Watch for devices going down and
 647  * delete our use of them (iface and route).
 648  */
 649 static int ddp_device_event(struct notifier_block *this, unsigned long event,
 650                             void *ptr)
 651 {
 652         if (event == NETDEV_DOWN)
 653                 /* Discard any use of this */
 654                 atalk_dev_down(ptr);
 655
 656         return NOTIFY_DONE;
 657 }
 658
 659 /* ioctl calls. Shouldn't even need touching */
 660 /* Device configuration ioctl calls */
 661 static int atif_ioctl(int cmd, void __user *arg)
 662 {
 663         static char aarp_mcast[6] = { 0x09, 0x00, 0x00, 0xFF, 0xFF, 0xFF };
 664         struct ifreq atreq;
 665         struct atalk_netrange *nr;
 666         struct sockaddr_at *sa;
 667         struct net_device *dev;
 668         struct atalk_iface *atif;
 669         int ct;
 670         int limit;
 671         struct rtentry rtdef;
 672         int add_route;
 673
 674         if (copy_from_user(&atreq, arg, sizeof(atreq)))
 675                 return -EFAULT;
 676
 677         dev = __dev_get_by_name(atreq.ifr_name);
 678         if (!dev)
 679                 return -ENODEV;
 680
 681         sa = (struct sockaddr_at *)&atreq.ifr_addr;
 682         atif = atalk_find_dev(dev);
 683
 684         switch (cmd) {
 685                 case SIOCSIFADDR:
 686                         if (!capable(CAP_NET_ADMIN))
 687                                 return -EPERM;
 688                         if (sa->sat_family != AF_APPLETALK)
 689                                 return -EINVAL;
 690                         if (dev->type != ARPHRD_ETHER &&
 691                             dev->type != ARPHRD_LOOPBACK &&
 692                             dev->type != ARPHRD_LOCALTLK &&
 693                             dev->type != ARPHRD_PPP)
 694                                 return -EPROTONOSUPPORT;
 695
 696                         nr = (struct atalk_netrange *)&sa->sat_zero[0];
 697                         add_route = 1;
 698
 699                         /*
 700                          * if this is a point-to-point iface, and we already
 701                          * have an iface for this AppleTalk address, then we
 702                          * should not add a route
 703                          */
 704                         if ((dev->flags & IFF_POINTOPOINT) &&
 705                             atalk_find_interface(sa->sat_addr.s_net,
 706                                                  sa->sat_addr.s_node)) {
 707                                 printk(KERN_DEBUG "AppleTalk: point-to-point "
 708                                                   "interface added with "
 709                                                   "existing address\n");
 710                                 add_route = 0;
 711                         }
 712
 713                         /*
 714                          * Phase 1 is fine on LocalTalk but we don't do
 715                          * EtherTalk phase 1. Anyone wanting to add it go ahead.
 716                          */
 717                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 718                                 return -EPROTONOSUPPORT;
 719                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 720                             sa->sat_addr.s_node == 254)
 721                                 return -EINVAL;
 722                         if (atif) {
 723                                 /* Already setting address */
 724                                 if (atif->status & ATIF_PROBE)
 725                                         return -EBUSY;
 726
 727                                 atif->address.s_net  = sa->sat_addr.s_net;
 728                                 atif->address.s_node = sa->sat_addr.s_node;
 729                                 atrtr_device_down(dev); /* Flush old routes */
 730                         } else {
 731                                 atif = atif_add_device(dev, &sa->sat_addr);
 732                                 if (!atif)
 733                                         return -ENOMEM;
 734                         }
 735                         atif->nets = *nr;
 736
 737                         /*
 738                          * Check if the chosen address is used. If so we
 739                          * error and atalkd will try another.
 740                          */
 741
 742                         if (!(dev->flags & IFF_LOOPBACK) &&
 743                             !(dev->flags & IFF_POINTOPOINT) &&
 744                             atif_probe_device(atif) < 0) {
 745                                 atif_drop_device(dev);
 746                                 return -EADDRINUSE;
 747                         }
 748
 749                         /* Hey it worked - add the direct routes */
 750                         sa = (struct sockaddr_at *)&rtdef.rt_gateway;
 751                         sa->sat_family = AF_APPLETALK;
 752                         sa->sat_addr.s_net  = atif->address.s_net;
 753                         sa->sat_addr.s_node = atif->address.s_node;
 754                         sa = (struct sockaddr_at *)&rtdef.rt_dst;
 755                         rtdef.rt_flags = RTF_UP;
 756                         sa->sat_family = AF_APPLETALK;
 757                         sa->sat_addr.s_node = ATADDR_ANYNODE;
 758                         if (dev->flags & IFF_LOOPBACK ||
 759                             dev->flags & IFF_POINTOPOINT)
 760                                 rtdef.rt_flags |= RTF_HOST;
 761
 762                         /* Routerless initial state */
 763                         if (nr->nr_firstnet == htons(0) &&
 764                             nr->nr_lastnet == htons(0xFFFE)) {
 765                                 sa->sat_addr.s_net = atif->address.s_net;
 766                                 atrtr_create(&rtdef, dev);
 767                                 atrtr_set_default(dev);
 768                         } else {
 769                                 limit = ntohs(nr->nr_lastnet);
 770                                 if (limit - ntohs(nr->nr_firstnet) > 4096) {
 771                                         printk(KERN_WARNING "Too many routes/"
 772                                                             "iface.\n");
 773                                         return -EINVAL;
 774                                 }
 775                                 if (add_route)
 776                                         for (ct = ntohs(nr->nr_firstnet);
 777                                              ct <= limit; ct++) {
 778                                                 sa->sat_addr.s_net = htons(ct);
 779                                                 atrtr_create(&rtdef, dev);
 780                                         }
 781                         }
 782                         dev_mc_add(dev, aarp_mcast, 6, 1);
 783                         return 0;
 784
 785                 case SIOCGIFADDR:
 786                         if (!atif)
 787                                 return -EADDRNOTAVAIL;
 788
 789                         sa->sat_family = AF_APPLETALK;
 790                         sa->sat_addr = atif->address;
 791                         break;
 792
 793                 case SIOCGIFBRDADDR:
 794                         if (!atif)
 795                                 return -EADDRNOTAVAIL;
 796
 797                         sa->sat_family = AF_APPLETALK;
 798                         sa->sat_addr.s_net = atif->address.s_net;
 799                         sa->sat_addr.s_node = ATADDR_BCAST;
 800                         break;
 801
 802                 case SIOCATALKDIFADDR:
 803                 case SIOCDIFADDR:
 804                         if (!capable(CAP_NET_ADMIN))
 805                                 return -EPERM;
 806                         if (sa->sat_family != AF_APPLETALK)
 807                                 return -EINVAL;
 808                         atalk_dev_down(dev);
 809                         break;
 810
 811                 case SIOCSARP:
 812                         if (!capable(CAP_NET_ADMIN))
 813                                 return -EPERM;
 814                         if (sa->sat_family != AF_APPLETALK)
 815                                 return -EINVAL;
 816                         if (!atif)
 817                                 return -EADDRNOTAVAIL;
 818
 819                         /*
 820                          * for now, we only support proxy AARP on ELAP;
 821                          * we should be able to do it for LocalTalk, too.
 822                          */
 823                         if (dev->type != ARPHRD_ETHER)
 824                                 return -EPROTONOSUPPORT;
 825
 826                         /*
 827                          * atif points to the current interface on this network;
 828                          * we aren't concerned about its current status (at
 829                          * least for now), but it has all the settings about
 830                          * the network we're going to probe. Consequently, it
 831                          * must exist.
 832                          */
 833                         if (!atif)
 834                                 return -EADDRNOTAVAIL;
 835
 836                         nr = (struct atalk_netrange *)&(atif->nets);
 837                         /*
 838                          * Phase 1 is fine on Localtalk but we don't do
 839                          * Ethertalk phase 1. Anyone wanting to add it go ahead.
 840                          */
 841                         if (dev->type == ARPHRD_ETHER && nr->nr_phase != 2)
 842                                 return -EPROTONOSUPPORT;
 843
 844                         if (sa->sat_addr.s_node == ATADDR_BCAST ||
 845                             sa->sat_addr.s_node == 254)
 846                                 return -EINVAL;
 847
 848                         /*
 849                          * Check if the chosen address is used. If so we
 850                          * error and ATCP will try another.
 851                          */
 852                         if (atif_proxy_probe_device(atif, &(sa->sat_addr)) < 0)
 853                                 return -EADDRINUSE;
 854
 855                         /*
 856                          * We now have an address on the local network, and
 857                          * the AARP code will defend it for us until we take it
 858                          * down. We don't set up any routes right now, because
 859                          * ATCP will install them manually via SIOCADDRT.
 860                          */
 861                         break;
 862
 863                 case SIOCDARP:
 864                         if (!capable(CAP_NET_ADMIN))
 865                                 return -EPERM;
 866                         if (sa->sat_family != AF_APPLETALK)
 867                                 return -EINVAL;
 868                         if (!atif)
 869                                 return -EADDRNOTAVAIL;
 870
 871                         /* give to aarp module to remove proxy entry */
 872                         aarp_proxy_remove(atif->dev, &(sa->sat_addr));
 873                         return 0;
 874         }
 875
 876         return copy_to_user(arg, &atreq, sizeof(atreq)) ? -EFAULT : 0;
 877 }
 878
 879 /* Routing ioctl() calls */
 880 static int atrtr_ioctl(unsigned int cmd, void __user *arg)
 881 {
 882         struct rtentry rt;
 883
 884         if (copy_from_user(&rt, arg, sizeof(rt)))
 885                 return -EFAULT;
 886
 887         switch (cmd) {
 888                 case SIOCDELRT:
 889                         if (rt.rt_dst.sa_family != AF_APPLETALK)
 890                                 return -EINVAL;
 891                         return atrtr_delete(&((struct sockaddr_at *)
 892                                                 &rt.rt_dst)->sat_addr);
 893
 894                 case SIOCADDRT: {
 895                         struct net_device *dev = NULL;
 896                         if (rt.rt_dev) {
 897                                 char name[IFNAMSIZ];
 898                                 if (copy_from_user(name, rt.rt_dev, IFNAMSIZ-1))
 899                                         return -EFAULT;
 900                                 name[IFNAMSIZ-1] = '\0';
 901                                 dev = __dev_get_by_name(name);
 902                                 if (!dev)
 903                                         return -ENODEV;
 904                         }
 905                         return atrtr_create(&rt, dev);
 906                 }
 907         }
 908         return -EINVAL;
 909 }
 910
 911 /**************************************************************************\
 912 *                                                                          *
 913 * Handling for system calls applied via the various interfaces to an       *
 914 * AppleTalk socket object.                                                 *
 915 *                                                                          *
 916 \**************************************************************************/
 917
 918 /*
 919  * Checksum: This is 'optional'. It's quite likely also a good
 920  * candidate for assembler hackery 8)
 921  */
 922 static unsigned long atalk_sum_partial(const unsigned char *data,
 923                                        int len, unsigned long sum)
 924 {
 925         /* This ought to be unwrapped neatly. I'll trust gcc for now */
 926         while (len--) {
 927                 sum += *data;
 928                 sum <<= 1;
 929                 if (sum & 0x10000) {
 930                         sum++;
 931                         sum &= 0xffff;
 932                 }
 933                 data++;
 934         }
 935         return sum;
 936 }
 937
 938 /*  Checksum skb data --  similar to skb_checksum  */
 939 static unsigned long atalk_sum_skb(const struct sk_buff *skb, int offset,
 940                                    int len, unsigned long sum)
 941 {
 942         int start = skb_headlen(skb);
 943         int i, copy;
 944
 945         /* checksum stuff in header space */
 946         if ( (copy = start - offset) > 0) {
 947                 if (copy > len)
 948                         copy = len;
 949                 sum = atalk_sum_partial(skb->data + offset, copy, sum);
 950                 if ( (len -= copy) == 0)
 951                         return sum;
 952
 953                 offset += copy;
 954         }
 955
 956         /* checksum stuff in frags */
 957         for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
 958                 int end;
 959
 960                 BUG_TRAP(start <= offset + len);
 961
 962                 end = start + skb_shinfo(skb)->frags[i].size;
 963                 if ((copy = end - offset) > 0) {
 964                         u8 *vaddr;
 965                         skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
 966
 967                         if (copy > len)
 968                                 copy = len;
 969                         vaddr = kmap_skb_frag(frag);
 970                         sum = atalk_sum_partial(vaddr + frag->page_offset +
 971                                                   offset - start, copy, sum);
 972                         kunmap_skb_frag(vaddr);
 973
 974                         if (!(len -= copy))
 975                                 return sum;
 976                         offset += copy;
 977                 }
 978                 start = end;
 979         }
 980
 981         if (skb_shinfo(skb)->frag_list) {
 982                 struct sk_buff *list = skb_shinfo(skb)->frag_list;
 983
 984                 for (; list; list = list->next) {
 985                         int end;
 986
 987                         BUG_TRAP(start <= offset + len);
 988
 989                         end = start + list->len;
 990                         if ((copy = end - offset) > 0) {
 991                                 if (copy > len)
 992                                         copy = len;
 993                                 sum = atalk_sum_skb(list, offset - start,
 994                                                     copy, sum);
 995                                 if ((len -= copy) == 0)
 996                                         return sum;
 997                                 offset += copy;
 998                         }
 999                         start = end;
1000                 }
1001         }
1002
1003         BUG_ON(len > 0);
1004
1005         return sum;
1006 }
1007
1008 static unsigned short atalk_checksum(const struct sk_buff *skb, int len)
1009 {
1010         unsigned long sum;
1011
1012         /* skip header 4 bytes */
1013         sum = atalk_sum_skb(skb, 4, len-4, 0);
1014
1015         /* Use 0xFFFF for 0. 0 itself means none */
1016         return sum ? htons((unsigned short)sum) : 0xFFFF;
1017 }
1018
1019 static struct proto ddp_proto = {
1020         .name     = "DDP",
1021         .owner    = THIS_MODULE,
1022         .obj_size = sizeof(struct atalk_sock),
1023 };
1024
1025 /*
1026  * Create a socket. Initialise the socket, blank the addresses
1027  * set the state.
1028  */
1029 static int atalk_create(struct socket *sock, int protocol)
1030 {
1031         struct sock *sk;
1032         int rc = -ESOCKTNOSUPPORT;
1033
1034         /*
1035          * We permit SOCK_DGRAM and RAW is an extension. It is trivial to do
1036          * and gives you the full ELAP frame. Should be handy for CAP 8)
1037          */
1038         if (sock->type != SOCK_RAW && sock->type != SOCK_DGRAM)
1039                 goto out;
1040         rc = -ENOMEM;
1041         sk = sk_alloc(PF_APPLETALK, GFP_KERNEL, &ddp_proto, 1);
1042         if (!sk)
1043                 goto out;
1044         rc = 0;
1045         sock->ops = &atalk_dgram_ops;
1046         sock_init_data(sock, sk);
1047
1048         /* Checksums on by default */
1049         sock_set_flag(sk, SOCK_ZAPPED);
1050 out:
1051         return rc;
1052 }
1053
1054 /* Free a socket. No work needed */
1055 static int atalk_release(struct socket *sock)
1056 {
1057         struct sock *sk = sock->sk;
1058
1059         if (sk) {
1060                 sock_orphan(sk);
1061                 sock->sk = NULL;
1062                 atalk_destroy_socket(sk);
1063         }
1064         return 0;
1065 }
1066
1067 /**
1068  * atalk_pick_and_bind_port - Pick a source port when one is not given
1069  * @sk - socket to insert into the tables
1070  * @sat - address to search for
1071  *
1072  * Pick a source port when one is not given. If we can find a suitable free
1073  * one, we insert the socket into the tables using it.
1074  *
1075  * This whole operation must be atomic.
1076  */
1077 static int atalk_pick_and_bind_port(struct sock *sk, struct sockaddr_at *sat)
1078 {
1079         int retval;
1080
1081         write_lock_bh(&atalk_sockets_lock);
1082
1083         for (sat->sat_port = ATPORT_RESERVED;
1084              sat->sat_port < ATPORT_LAST;
1085              sat->sat_port++) {
1086                 struct sock *s;
1087                 struct hlist_node *node;
1088
1089                 sk_for_each(s, node, &atalk_sockets) {
1090                         struct atalk_sock *at = at_sk(s);
1091
1092                         if (at->src_net == sat->sat_addr.s_net &&
1093                             at->src_node == sat->sat_addr.s_node &&
1094                             at->src_port == sat->sat_port)
1095                                 goto try_next_port;
1096                 }
1097
1098                 /* Wheee, it's free, assign and insert. */
1099                 __atalk_insert_socket(sk);
1100                 at_sk(sk)->src_port = sat->sat_port;
1101                 retval = 0;
1102                 goto out;
1103
1104 try_next_port:;
1105         }
1106
1107         retval = -EBUSY;
1108 out:
1109         write_unlock_bh(&atalk_sockets_lock);
1110         return retval;
1111 }
1112
1113 static int atalk_autobind(struct sock *sk)
1114 {
1115         struct atalk_sock *at = at_sk(sk);
1116         struct sockaddr_at sat;
1117         struct atalk_addr *ap = atalk_find_primary();
1118         int n = -EADDRNOTAVAIL;
1119
1120         if (!ap || ap->s_net == htons(ATADDR_ANYNET))
1121                 goto out;
1122
1123         at->src_net  = sat.sat_addr.s_net  = ap->s_net;
1124         at->src_node = sat.sat_addr.s_node = ap->s_node;
1125
1126         n = atalk_pick_and_bind_port(sk, &sat);
1127         if (!n)
1128                 sock_reset_flag(sk, SOCK_ZAPPED);
1129 out:
1130         return n;
1131 }
1132
1133 /* Set the address 'our end' of the connection */
1134 static int atalk_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
1135 {
1136         struct sockaddr_at *addr = (struct sockaddr_at *)uaddr;
1137         struct sock *sk = sock->sk;
1138         struct atalk_sock *at = at_sk(sk);
1139
1140         if (!sock_flag(sk, SOCK_ZAPPED) ||
1141             addr_len != sizeof(struct sockaddr_at))
1142                 return -EINVAL;
1143
1144         if (addr->sat_family != AF_APPLETALK)
1145                 return -EAFNOSUPPORT;
1146
1147         if (addr->sat_addr.s_net == htons(ATADDR_ANYNET)) {
1148                 struct atalk_addr *ap = atalk_find_primary();
1149
1150                 if (!ap)
1151                         return -EADDRNOTAVAIL;
1152
1153                 at->src_net  = addr->sat_addr.s_net = ap->s_net;
1154                 at->src_node = addr->sat_addr.s_node= ap->s_node;
1155         } else {
1156                 if (!atalk_find_interface(addr->sat_addr.s_net,
1157                                           addr->sat_addr.s_node))
1158                         return -EADDRNOTAVAIL;
1159
1160                 at->src_net  = addr->sat_addr.s_net;
1161                 at->src_node = addr->sat_addr.s_node;
1162         }
1163
1164         if (addr->sat_port == ATADDR_ANYPORT) {
1165                 int n = atalk_pick_and_bind_port(sk, addr);
1166
1167                 if (n < 0)
1168                         return n;
1169         } else {
1170                 at->src_port = addr->sat_port;
1171
1172                 if (atalk_find_or_insert_socket(sk, addr))
1173                         return -EADDRINUSE;
1174         }
1175
1176         sock_reset_flag(sk, SOCK_ZAPPED);
1177         return 0;
1178 }
1179
1180 /* Set the address we talk to */
1181 static int atalk_connect(struct socket *sock, struct sockaddr *uaddr,
1182                          int addr_len, int flags)
1183 {
1184         struct sock *sk = sock->sk;
1185         struct atalk_sock *at = at_sk(sk);
1186         struct sockaddr_at *addr;
1187
1188         sk->sk_state   = TCP_CLOSE;
1189         sock->state = SS_UNCONNECTED;
1190
1191         if (addr_len != sizeof(*addr))
1192                 return -EINVAL;
1193
1194         addr = (struct sockaddr_at *)uaddr;
1195
1196         if (addr->sat_family != AF_APPLETALK)
1197                 return -EAFNOSUPPORT;
1198
1199         if (addr->sat_addr.s_node == ATADDR_BCAST &&
1200             !sock_flag(sk, SOCK_BROADCAST)) {
1201 #if 1
1202                 printk(KERN_WARNING "%s is broken and did not set "
1203                                     "SO_BROADCAST. It will break when 2.2 is "
1204                                     "released.\n",
1205                         current->comm);
1206 #else
1207                 return -EACCES;
1208 #endif
1209         }
1210
1211         if (sock_flag(sk, SOCK_ZAPPED))
1212                 if (atalk_autobind(sk) < 0)
1213                         return -EBUSY;
1214
1215         if (!atrtr_get_dev(&addr->sat_addr))
1216                 return -ENETUNREACH;
1217
1218         at->dest_port = addr->sat_port;
1219         at->dest_net  = addr->sat_addr.s_net;
1220         at->dest_node = addr->sat_addr.s_node;
1221
1222         sock->state  = SS_CONNECTED;
1223         sk->sk_state = TCP_ESTABLISHED;
1224         return 0;
1225 }
1226
1227 /*
1228  * Find the name of an AppleTalk socket. Just copy the right
1229  * fields into the sockaddr.
1230  */
1231 static int atalk_getname(struct socket *sock, struct sockaddr *uaddr,
1232                          int *uaddr_len, int peer)
1233 {
1234         struct sockaddr_at sat;
1235         struct sock *sk = sock->sk;
1236         struct atalk_sock *at = at_sk(sk);
1237
1238         if (sock_flag(sk, SOCK_ZAPPED))
1239                 if (atalk_autobind(sk) < 0)
1240                         return -ENOBUFS;
1241
1242         *uaddr_len = sizeof(struct sockaddr_at);
1243
1244         if (peer) {
1245                 if (sk->sk_state != TCP_ESTABLISHED)
1246                         return -ENOTCONN;
1247
1248                 sat.sat_addr.s_net  = at->dest_net;
1249                 sat.sat_addr.s_node = at->dest_node;
1250                 sat.sat_port        = at->dest_port;
1251         } else {
1252                 sat.sat_addr.s_net  = at->src_net;
1253                 sat.sat_addr.s_node = at->src_node;
1254                 sat.sat_port        = at->src_port;
1255         }
1256
1257         sat.sat_family = AF_APPLETALK;
1258         memcpy(uaddr, &sat, sizeof(sat));
1259         return 0;
1260 }
1261
1262 #if defined(CONFIG_IPDDP) || defined(CONFIG_IPDDP_MODULE)
1263 static __inline__ int is_ip_over_ddp(struct sk_buff *skb)
1264 {
1265         return skb->data[12] == 22;
1266 }
1267
1268 static int handle_ip_over_ddp(struct sk_buff *skb)
1269 {
1270         struct net_device *dev = __dev_get_by_name("ipddp0");
1271         struct net_device_stats *stats;
1272
1273         /* This needs to be able to handle ipddp"N" devices */
1274         if (!dev)
1275                 return -ENODEV;
1276
1277         skb->protocol = htons(ETH_P_IP);
1278         skb_pull(skb, 13);
1279         skb->dev   = dev;
1280         skb->h.raw = skb->data;
1281
1282         stats = dev->priv;
1283         stats->rx_packets++;
1284         stats->rx_bytes += skb->len + 13;
1285         netif_rx(skb);  /* Send the SKB up to a higher place. */
1286         return 0;
1287 }
1288 #else
1289 /* make it easy for gcc to optimize this test out, i.e. kill the code */
1290 #define is_ip_over_ddp(skb) 0
1291 #define handle_ip_over_ddp(skb) 0
1292 #endif
1293
1294 static void atalk_route_packet(struct sk_buff *skb, struct net_device *dev,
1295                                struct ddpehdr *ddp, struct ddpebits *ddphv,
1296                                int origlen)
1297 {
1298         struct atalk_route *rt;
1299         struct atalk_addr ta;
1300
1301         /*
1302          * Don't route multicast, etc., packets, or packets sent to "this
1303          * network"
1304          */
1305         if (skb->pkt_type != PACKET_HOST || !ddp->deh_dnet) {
1306                 /*
1307                  * FIXME:
1308                  *
1309                  * Can it ever happen that a packet is from a PPP iface and
1310                  * needs to be broadcast onto the default network?
1311                  */
1312                 if (dev->type == ARPHRD_PPP)
1313                         printk(KERN_DEBUG "AppleTalk: didn't forward broadcast "
1314                                           "packet received from PPP iface\n");
1315                 goto free_it;
1316         }
1317
1318         ta.s_net  = ddp->deh_dnet;
1319         ta.s_node = ddp->deh_dnode;
1320
1321         /* Route the packet */
1322         rt = atrtr_find(&ta);
1323         if (!rt || ddphv->deh_hops == DDP_MAXHOPS)
1324                 goto free_it;
1325         /* FIXME: use skb->cb to be able to use shared skbs */
1326         ddphv->deh_hops++;
1327
1328         /*
1329          * Route goes through another gateway, so set the target to the
1330          * gateway instead.
1331          */
1332
1333         if (rt->flags & RTF_GATEWAY) {
1334                 ta.s_net  = rt->gateway.s_net;
1335                 ta.s_node = rt->gateway.s_node;
1336         }
1337
1338         /* Fix up skb->len field */
1339         skb_trim(skb, min_t(unsigned int, origlen,
1340                             (rt->dev->hard_header_len +
1341                              ddp_dl->header_length + ddphv->deh_len)));
1342
1343         /* Mend the byte order */
1344         /* FIXME: use skb->cb to be able to use shared skbs */
1345         *((__u16 *)ddp) = ntohs(*((__u16 *)ddphv));
1346
1347         /*
1348          * Send the buffer onwards
1349          *
1350          * Now we must always be careful. If it's come from LocalTalk to
1351          * EtherTalk it might not fit
1352          *
1353          * Order matters here: If a packet has to be copied to make a new
1354          * headroom (rare hopefully) then it won't need unsharing.
1355          *
1356          * Note. ddp-> becomes invalid at the realloc.
1357          */
1358         if (skb_headroom(skb) < 22) {
1359                 /* 22 bytes - 12 ether, 2 len, 3 802.2 5 snap */
1360                 struct sk_buff *nskb = skb_realloc_headroom(skb, 32);
1361                 kfree_skb(skb);
1362                 if (!nskb)
1363                         goto out;
1364                 skb = nskb;
1365         } else
1366                 skb = skb_unshare(skb, GFP_ATOMIC);
1367
1368         /*
1369          * If the buffer didn't vanish into the lack of space bitbucket we can
1370          * send it.
1371          */
1372         if (skb && aarp_send_ddp(rt->dev, skb, &ta, NULL) == -1)
1373                 goto free_it;
1374 out:
1375         return;
1376 free_it:
1377         kfree_skb(skb);
1378 }
1379
1380 /**
1381  *      atalk_rcv - Receive a packet (in skb) from device dev
1382  *      @skb - packet received
1383  *      @dev - network device where the packet comes from
1384  *      @pt - packet type
1385  *
1386  *      Receive a packet (in skb) from device dev. This has come from the SNAP
1387  *      decoder, and on entry skb->h.raw is the DDP header, skb->len is the DDP
1388  *      header, skb->len is the DDP length. The physical headers have been
1389  *      extracted. PPP should probably pass frames marked as for this layer.
1390  *      [ie ARPHRD_ETHERTALK]
1391  */
1392 static int atalk_rcv(struct sk_buff *skb, struct net_device *dev,
1393                      struct packet_type *pt, struct net_device *orig_dev)
1394 {
1395         struct ddpehdr *ddp;
1396         struct sock *sock;
1397         struct atalk_iface *atif;
1398         struct sockaddr_at tosat;
1399         int origlen;
1400         struct ddpebits ddphv;
1401
1402         /* Don't mangle buffer if shared */
1403         if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1404                 goto out;
1405
1406         /* Size check and make sure header is contiguous */
1407         if (!pskb_may_pull(skb, sizeof(*ddp)))
1408                 goto freeit;
1409
1410         ddp = ddp_hdr(skb);
1411
1412         /*
1413          *      Fix up the length field [Ok this is horrible but otherwise
1414          *      I end up with unions of bit fields and messy bit field order
1415          *      compiler/endian dependencies..]
1416          */
1417         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1418
1419         /* Trim buffer in case of stray trailing data */
1420         origlen = skb->len;
1421         skb_trim(skb, min_t(unsigned int, skb->len, ddphv.deh_len));
1422
1423         /*
1424          * Size check to see if ddp->deh_len was crap
1425          * (Otherwise we'll detonate most spectacularly
1426          * in the middle of recvmsg()).
1427          */
1428         if (skb->len < sizeof(*ddp))
1429                 goto freeit;
1430
1431         /*
1432          * Any checksums. Note we don't do htons() on this == is assumed to be
1433          * valid for net byte orders all over the networking code...
1434          */
1435         if (ddp->deh_sum &&
1436             atalk_checksum(skb, ddphv.deh_len) != ddp->deh_sum)
1437                 /* Not a valid AppleTalk frame - dustbin time */
1438                 goto freeit;
1439
1440         /* Check the packet is aimed at us */
1441         if (!ddp->deh_dnet)     /* Net 0 is 'this network' */
1442                 atif = atalk_find_anynet(ddp->deh_dnode, dev);
1443         else
1444                 atif = atalk_find_interface(ddp->deh_dnet, ddp->deh_dnode);
1445
1446         /* Not ours, so we route the packet via the correct AppleTalk iface */
1447         if (!atif) {
1448                 atalk_route_packet(skb, dev, ddp, &ddphv, origlen);
1449                 goto out;
1450         }
1451
1452         /* if IP over DDP is not selected this code will be optimized out */
1453         if (is_ip_over_ddp(skb))
1454                 return handle_ip_over_ddp(skb);
1455         /*
1456          * Which socket - atalk_search_socket() looks for a *full match*
1457          * of the <net, node, port> tuple.
1458          */
1459         tosat.sat_addr.s_net  = ddp->deh_dnet;
1460         tosat.sat_addr.s_node = ddp->deh_dnode;
1461         tosat.sat_port        = ddp->deh_dport;
1462
1463         sock = atalk_search_socket(&tosat, atif);
1464         if (!sock) /* But not one of our sockets */
1465                 goto freeit;
1466
1467         /* Queue packet (standard) */
1468         skb->sk = sock;
1469
1470         if (sock_queue_rcv_skb(sock, skb) < 0)
1471                 goto freeit;
1472 out:
1473         return 0;
1474 freeit:
1475         kfree_skb(skb);
1476         goto out;
1477 }
1478
1479 /*
1480  * Receive a LocalTalk frame. We make some demands on the caller here.
1481  * Caller must provide enough headroom on the packet to pull the short
1482  * header and append a long one.
1483  */
1484 static int ltalk_rcv(struct sk_buff *skb, struct net_device *dev,
1485                      struct packet_type *pt, struct net_device *orig_dev)
1486 {
1487         /* Expand any short form frames */
1488         if (skb->mac.raw[2] == 1) {
1489                 struct ddpehdr *ddp;
1490                 /* Find our address */
1491                 struct atalk_addr *ap = atalk_find_dev_addr(dev);
1492
1493                 if (!ap || skb->len < sizeof(struct ddpshdr))
1494                         goto freeit;
1495
1496                 /* Don't mangle buffer if shared */
1497                 if (!(skb = skb_share_check(skb, GFP_ATOMIC)))
1498                         return 0;
1499
1500                 /*
1501                  * The push leaves us with a ddephdr not an shdr, and
1502                  * handily the port bytes in the right place preset.
1503                  */
1504                 ddp = (struct ddpehdr *) skb_push(skb, sizeof(*ddp) - 4);
1505
1506                 /* Now fill in the long header */
1507
1508                 /*
1509                  * These two first. The mac overlays the new source/dest
1510                  * network information so we MUST copy these before
1511                  * we write the network numbers !
1512                  */
1513
1514                 ddp->deh_dnode = skb->mac.raw[0];     /* From physical header */
1515                 ddp->deh_snode = skb->mac.raw[1];     /* From physical header */
1516
1517                 ddp->deh_dnet  = ap->s_net;     /* Network number */
1518                 ddp->deh_snet  = ap->s_net;
1519                 ddp->deh_sum   = 0;             /* No checksum */
1520                 /*
1521                  * Not sure about this bit...
1522                  */
1523                 ddp->deh_len   = skb->len;
1524                 ddp->deh_hops  = DDP_MAXHOPS;   /* Non routable, so force a drop
1525                                                    if we slip up later */
1526                 /* Mend the byte order */
1527                 *((__u16 *)ddp) = htons(*((__u16 *)ddp));
1528         }
1529         skb->h.raw = skb->data;
1530
1531         return atalk_rcv(skb, dev, pt, orig_dev);
1532 freeit:
1533         kfree_skb(skb);
1534         return 0;
1535 }
1536
1537 static int atalk_sendmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1538                          size_t len)
1539 {
1540         struct sock *sk = sock->sk;
1541         struct atalk_sock *at = at_sk(sk);
1542         struct sockaddr_at *usat = (struct sockaddr_at *)msg->msg_name;
1543         int flags = msg->msg_flags;
1544         int loopback = 0;
1545         struct sockaddr_at local_satalk, gsat;
1546         struct sk_buff *skb;
1547         struct net_device *dev;
1548         struct ddpehdr *ddp;
1549         int size;
1550         struct atalk_route *rt;
1551         int err;
1552
1553         if (flags & ~(MSG_DONTWAIT|MSG_CMSG_COMPAT))
1554                 return -EINVAL;
1555
1556         if (len > DDP_MAXSZ)
1557                 return -EMSGSIZE;
1558
1559         if (usat) {
1560                 if (sock_flag(sk, SOCK_ZAPPED))
1561                         if (atalk_autobind(sk) < 0)
1562                                 return -EBUSY;
1563
1564                 if (msg->msg_namelen < sizeof(*usat) ||
1565                     usat->sat_family != AF_APPLETALK)
1566                         return -EINVAL;
1567
1568                 /* netatalk doesn't implement this check */
1569                 if (usat->sat_addr.s_node == ATADDR_BCAST &&
1570                     !sock_flag(sk, SOCK_BROADCAST)) {
1571                         printk(KERN_INFO "SO_BROADCAST: Fix your netatalk as "
1572                                          "it will break before 2.2\n");
1573 #if 0
1574                         return -EPERM;
1575 #endif
1576                 }
1577         } else {
1578                 if (sk->sk_state != TCP_ESTABLISHED)
1579                         return -ENOTCONN;
1580                 usat = &local_satalk;
1581                 usat->sat_family      = AF_APPLETALK;
1582                 usat->sat_port        = at->dest_port;
1583                 usat->sat_addr.s_node = at->dest_node;
1584                 usat->sat_addr.s_net  = at->dest_net;
1585         }
1586
1587         /* Build a packet */
1588         SOCK_DEBUG(sk, "SK %p: Got address.\n", sk);
1589
1590         /* For headers */
1591         size = sizeof(struct ddpehdr) + len + ddp_dl->header_length;
1592
1593         if (usat->sat_addr.s_net || usat->sat_addr.s_node == ATADDR_ANYNODE) {
1594                 rt = atrtr_find(&usat->sat_addr);
1595                 if (!rt)
1596                         return -ENETUNREACH;
1597
1598                 dev = rt->dev;
1599         } else {
1600                 struct atalk_addr at_hint;
1601
1602                 at_hint.s_node = 0;
1603                 at_hint.s_net  = at->src_net;
1604
1605                 rt = atrtr_find(&at_hint);
1606                 if (!rt)
1607                         return -ENETUNREACH;
1608
1609                 dev = rt->dev;
1610         }
1611
1612         SOCK_DEBUG(sk, "SK %p: Size needed %d, device %s\n",
1613                         sk, size, dev->name);
1614
1615         size += dev->hard_header_len;
1616         skb = sock_alloc_send_skb(sk, size, (flags & MSG_DONTWAIT), &err);
1617         if (!skb)
1618                 return err;
1619
1620         skb->sk = sk;
1621         skb_reserve(skb, ddp_dl->header_length);
1622         skb_reserve(skb, dev->hard_header_len);
1623         skb->dev = dev;
1624
1625         SOCK_DEBUG(sk, "SK %p: Begin build.\n", sk);
1626
1627         ddp = (struct ddpehdr *)skb_put(skb, sizeof(struct ddpehdr));
1628         ddp->deh_pad  = 0;
1629         ddp->deh_hops = 0;
1630         ddp->deh_len  = len + sizeof(*ddp);
1631         /*
1632          * Fix up the length field [Ok this is horrible but otherwise
1633          * I end up with unions of bit fields and messy bit field order
1634          * compiler/endian dependencies..
1635          */
1636         *((__u16 *)ddp) = ntohs(*((__u16 *)ddp));
1637
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         SOCK_DEBUG(sk, "SK %p: Copy user data (%Zd bytes).\n", sk, len);
1646
1647         err = memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len);
1648         if (err) {
1649                 kfree_skb(skb);
1650                 return -EFAULT;
1651         }
1652
1653         if (sk->sk_no_check == 1)
1654                 ddp->deh_sum = 0;
1655         else
1656                 ddp->deh_sum = atalk_checksum(skb, len + sizeof(*ddp));
1657
1658         /*
1659          * Loopback broadcast packets to non gateway targets (ie routes
1660          * to group we are in)
1661          */
1662         if (ddp->deh_dnode == ATADDR_BCAST &&
1663             !(rt->flags & RTF_GATEWAY) && !(dev->flags & IFF_LOOPBACK)) {
1664                 struct sk_buff *skb2 = skb_copy(skb, GFP_KERNEL);
1665
1666                 if (skb2) {
1667                         loopback = 1;
1668                         SOCK_DEBUG(sk, "SK %p: send out(copy).\n", sk);
1669                         if (aarp_send_ddp(dev, skb2,
1670                                           &usat->sat_addr, NULL) == -1)
1671                                 kfree_skb(skb2);
1672                                 /* else queued/sent above in the aarp queue */
1673                 }
1674         }
1675
1676         if (dev->flags & IFF_LOOPBACK || loopback) {
1677                 SOCK_DEBUG(sk, "SK %p: Loop back.\n", sk);
1678                 /* loop back */
1679                 skb_orphan(skb);
1680                 ddp_dl->request(ddp_dl, skb, dev->dev_addr);
1681         } else {
1682                 SOCK_DEBUG(sk, "SK %p: send out.\n", sk);
1683                 if (rt->flags & RTF_GATEWAY) {
1684                     gsat.sat_addr = rt->gateway;
1685                     usat = &gsat;
1686                 }
1687
1688                 if (aarp_send_ddp(dev, skb, &usat->sat_addr, NULL) == -1)
1689                         kfree_skb(skb);
1690                 /* else queued/sent above in the aarp queue */
1691         }
1692         SOCK_DEBUG(sk, "SK %p: Done write (%Zd).\n", sk, len);
1693
1694         return len;
1695 }
1696
1697 static int atalk_recvmsg(struct kiocb *iocb, struct socket *sock, struct msghdr *msg,
1698                          size_t size, int flags)
1699 {
1700         struct sock *sk = sock->sk;
1701         struct sockaddr_at *sat = (struct sockaddr_at *)msg->msg_name;
1702         struct ddpehdr *ddp;
1703         int copied = 0;
1704         int err = 0;
1705         struct ddpebits ddphv;
1706         struct sk_buff *skb = skb_recv_datagram(sk, flags & ~MSG_DONTWAIT,
1707                                                 flags & MSG_DONTWAIT, &err);
1708         if (!skb)
1709                 return err;
1710
1711         /* FIXME: use skb->cb to be able to use shared skbs */
1712         ddp = ddp_hdr(skb);
1713         *((__u16 *)&ddphv) = ntohs(*((__u16 *)ddp));
1714
1715         if (sk->sk_type == SOCK_RAW) {
1716                 copied = ddphv.deh_len;
1717                 if (copied > size) {
1718                         copied = size;
1719                         msg->msg_flags |= MSG_TRUNC;
1720                 }
1721
1722                 err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied);
1723         } else {
1724                 copied = ddphv.deh_len - sizeof(*ddp);
1725                 if (copied > size) {
1726                         copied = size;
1727                         msg->msg_flags |= MSG_TRUNC;
1728                 }
1729                 err = skb_copy_datagram_iovec(skb, sizeof(*ddp),
1730                                               msg->msg_iov, copied);
1731         }
1732
1733         if (!err) {
1734                 if (sat) {
1735                         sat->sat_family      = AF_APPLETALK;
1736                         sat->sat_port        = ddp->deh_sport;
1737                         sat->sat_addr.s_node = ddp->deh_snode;
1738                         sat->sat_addr.s_net  = ddp->deh_snet;
1739                 }
1740                 msg->msg_namelen = sizeof(*sat);
1741         }
1742
1743         skb_free_datagram(sk, skb);     /* Free the datagram. */
1744         return err ? : copied;
1745 }
1746
1747
1748 /*
1749  * AppleTalk ioctl calls.
1750  */
1751 static int atalk_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
1752 {
1753         int rc = -EINVAL;
1754         struct sock *sk = sock->sk;
1755         void __user *argp = (void __user *)arg;
1756
1757         switch (cmd) {
1758                 /* Protocol layer */
1759                 case TIOCOUTQ: {
1760                         long amount = sk->sk_sndbuf -
1761                                       atomic_read(&sk->sk_wmem_alloc);
1762
1763                         if (amount < 0)
1764                                 amount = 0;
1765                         rc = put_user(amount, (int __user *)argp);
1766                         break;
1767                 }
1768                 case TIOCINQ: {
1769                         /*
1770                          * These two are safe on a single CPU system as only
1771                          * user tasks fiddle here
1772                          */
1773                         struct sk_buff *skb = skb_peek(&sk->sk_receive_queue);
1774                         long amount = 0;
1775
1776                         if (skb)
1777                                 amount = skb->len - sizeof(struct ddpehdr);
1778                         rc = put_user(amount, (int __user *)argp);
1779                         break;
1780                 }
1781                 case SIOCGSTAMP:
1782                         rc = sock_get_timestamp(sk, argp);
1783                         break;
1784                 /* Routing */
1785                 case SIOCADDRT:
1786                 case SIOCDELRT:
1787                         rc = -EPERM;
1788                         if (capable(CAP_NET_ADMIN))
1789                                 rc = atrtr_ioctl(cmd, argp);
1790                         break;
1791                 /* Interface */
1792                 case SIOCGIFADDR:
1793                 case SIOCSIFADDR:
1794                 case SIOCGIFBRDADDR:
1795                 case SIOCATALKDIFADDR:
1796                 case SIOCDIFADDR:
1797                 case SIOCSARP:          /* proxy AARP */
1798                 case SIOCDARP:          /* proxy AARP */
1799                         rtnl_lock();
1800                         rc = atif_ioctl(cmd, argp);
1801                         rtnl_unlock();
1802                         break;
1803                 /* Physical layer ioctl calls */
1804                 case SIOCSIFLINK:
1805                 case SIOCGIFHWADDR:
1806                 case SIOCSIFHWADDR:
1807                 case SIOCGIFFLAGS:
1808                 case SIOCSIFFLAGS:
1809                 case SIOCGIFTXQLEN:
1810                 case SIOCSIFTXQLEN:
1811                 case SIOCGIFMTU:
1812                 case SIOCGIFCONF:
1813                 case SIOCADDMULTI:
1814                 case SIOCDELMULTI:
1815                 case SIOCGIFCOUNT:
1816                 case SIOCGIFINDEX:
1817                 case SIOCGIFNAME:
1818                         rc = dev_ioctl(cmd, argp);
1819                         break;
1820         }
1821
1822         return rc;
1823 }
1824
1825 static struct net_proto_family atalk_family_ops = {
1826         .family         = PF_APPLETALK,
1827         .create         = atalk_create,
1828         .owner          = THIS_MODULE,
1829 };
1830
1831 static struct proto_ops SOCKOPS_WRAPPED(atalk_dgram_ops) = {
1832         .family         = PF_APPLETALK,
1833         .owner          = THIS_MODULE,
1834         .release        = atalk_release,
1835         .bind           = atalk_bind,
1836         .connect        = atalk_connect,
1837         .socketpair     = sock_no_socketpair,
1838         .accept         = sock_no_accept,
1839         .getname        = atalk_getname,
1840         .poll           = datagram_poll,
1841         .ioctl          = atalk_ioctl,
1842         .listen         = sock_no_listen,
1843         .shutdown       = sock_no_shutdown,
1844         .setsockopt     = sock_no_setsockopt,
1845         .getsockopt     = sock_no_getsockopt,
1846         .sendmsg        = atalk_sendmsg,
1847         .recvmsg        = atalk_recvmsg,
1848         .mmap           = sock_no_mmap,
1849         .sendpage       = sock_no_sendpage,
1850 };
1851
1852 #include <linux/smp_lock.h>
1853 SOCKOPS_WRAP(atalk_dgram, PF_APPLETALK);
1854
1855 static struct notifier_block ddp_notifier = {
1856         .notifier_call  = ddp_device_event,
1857 };
1858
1859 static struct packet_type ltalk_packet_type = {
1860         .type           = __constant_htons(ETH_P_LOCALTALK),
1861         .func           = ltalk_rcv,
1862 };
1863
1864 static struct packet_type ppptalk_packet_type = {
1865         .type           = __constant_htons(ETH_P_PPPTALK),
1866         .func           = atalk_rcv,
1867 };
1868
1869 static unsigned char ddp_snap_id[] = { 0x08, 0x00, 0x07, 0x80, 0x9B };
1870
1871 /* Export symbols for use by drivers when AppleTalk is a module */
1872 EXPORT_SYMBOL(aarp_send_ddp);
1873 EXPORT_SYMBOL(atrtr_get_dev);
1874 EXPORT_SYMBOL(atalk_find_dev_addr);
1875
1876 static char atalk_err_snap[] __initdata =
1877         KERN_CRIT "Unable to register DDP with SNAP.\n";
1878
1879 /* Called by proto.c on kernel start up */
1880 static int __init atalk_init(void)
1881 {
1882         int rc = proto_register(&ddp_proto, 0);
1883
1884         if (rc != 0)
1885                 goto out;
1886
1887         (void)sock_register(&atalk_family_ops);
1888         ddp_dl = register_snap_client(ddp_snap_id, atalk_rcv);
1889         if (!ddp_dl)
1890                 printk(atalk_err_snap);
1891
1892         dev_add_pack(&ltalk_packet_type);
1893         dev_add_pack(&ppptalk_packet_type);
1894
1895         register_netdevice_notifier(&ddp_notifier);
1896         aarp_proto_init();
1897         atalk_proc_init();
1898         atalk_register_sysctl();
1899 out:
1900         return rc;
1901 }
1902 module_init(atalk_init);
1903
1904 /*
1905  * No explicit module reference count manipulation is needed in the
1906  * protocol. Socket layer sets module reference count for us
1907  * and interfaces reference counting is done
1908  * by the network device layer.
1909  *
1910  * Ergo, before the AppleTalk module can be removed, all AppleTalk
1911  * sockets be closed from user space.
1912  */
1913 static void __exit atalk_exit(void)
1914 {
1915 #ifdef CONFIG_SYSCTL
1916         atalk_unregister_sysctl();
1917 #endif /* CONFIG_SYSCTL */
1918         atalk_proc_exit();
1919         aarp_cleanup_module();  /* General aarp clean-up. */
1920         unregister_netdevice_notifier(&ddp_notifier);
1921         dev_remove_pack(&ltalk_packet_type);
1922         dev_remove_pack(&ppptalk_packet_type);
1923         unregister_snap_client(ddp_dl);
1924         sock_unregister(PF_APPLETALK);
1925         proto_unregister(&ddp_proto);
1926 }
1927 module_exit(atalk_exit);
1928
1929 MODULE_LICENSE("GPL");
1930 MODULE_AUTHOR("Alan Cox <Alan.Cox@linux.org>");
1931 MODULE_DESCRIPTION("AppleTalk 0.20\n");
1932 MODULE_ALIAS_NETPROTO(PF_APPLETALK);